docid
stringlengths 4
9
| text
stringlengths 174
10k
| title
stringlengths 2
300
|
|---|---|---|
38037690 | Abstract. Stimulated Raman scattering (SRS) microscopy is used to generate structural and chemical three-dimensional images of native skin. We employed SRS microscopy to investigate the microanatomical features of skin and penetration of topically applied materials. Image depth stacks are collected at distinct wavelengths corresponding to vibrational modes of proteins, lipids, and water in the skin. We observed that corneocytes in stratum corneum are grouped together in clusters, 100 to 250 μm in diameter, separated by 10- to 25-μm-wide microanatomical skin-folds called canyons. These canyons occasionally extend down to depths comparable to that of the dermal–epidermal junction below the flat surface regions in porcine and human skin. SRS imaging shows the distribution of chemical species within cell clusters and canyons. Water is predominately located within the cell clusters, and its concentration rapidly increases at the transition from stratum corneum to viable epidermis. Canyons do not contain detectable levels of water and are rich in lipid material. Oleic acid-d34 applied to the skin surface lines the canyons down to a depth of 50 μm below the surface of the skin. This observation could have implications on the evaluation of penetration profiles of bioactive materials measured using traditional methods, such as tape-stripping. | Three-dimensional chemical imaging of skin using stimulated Raman scattering microscopy |
38040186 | Between 1961 and 1990, 52 patients with biopsy-proven familial amyloidosis born in North America were examined at the Mayo Clinic. At the time of diagnosis of familial amyloidosis, 83% of these patients had peripheral neuropathy, 33% had autonomic neuropathy, and 27% had cardiomyopathy. Renal disease was noted in fewer than 10%, and liver involvement was rare. The median age at diagnosis was 64 years. The sensitivity of various diagnostic biopsies was similar to that for primary amyloidosis: deposits of amyloid were found in 77 and 78% of the subcutaneous fat aspirates or rectal biopsy specimens, respectively, and in 41% of specimens of bone marrow. The median duration of survival of 5.8 years for patients with inherited amyloidosis was superior to that for patients with primary amyloidosis. When patients were stratified by organ involvement, the survival of patients with familial amyloidosis remained superior. The presence of cardiomyopathy and an interactive variable of age and the presence of autonomic neuropathy were powerful predictors of survival. Of the 52 patients, 22 died, 12 (55%) of cardiac failure or cardiac arrhythmia. Nine patients (41%) died of inanition in conjunction with progressive peripheral or autonomic neuropathy. Transthyretin was identified by immunohistochemical studies in 31 of the 34 tissue specimens tested. A transthyretin mutation was identified in 24 of the 31. A transthyretin mutation was found in five additional patients for whom tissue was unavailable for immunostaining. | Familial amyloidosis: a study of 52 North American-born patients examined during a 30-year period. |
38043606 | Once across the barrier of the epithelium, macrophages constitute the primary defense against microbial invasion. For most microbes, the acidic, hydrolytically competent environment of the phagolysosome is sufficient to kill them. Despite our understanding of the trafficking events that regulate phagosome maturation, our appreciation of the lumenal environment within the phagosome is only now becoming elucidated through real-time functional assays. The assays quantify pH change, phagosome/lysosome fusion, proteolysis, lipolysis, and beta-galactosidase activity. This information is particularly important for understanding pathogens that successfully parasitize the endosomal/lysosomal continuum. Mycobacterium tuberculosis infects macrophages through arresting the normal maturation process of the phagosome, retaining its vacuole at pH 6.4 with many of the characteristics of an early endosome. Current studies are focusing on the transcriptional response of the bacterium to the changing environment in the macrophage phagosome. Manipulation of these environmental cues, such as preventing the pH drop to pH 6.4 with concanamycin A, abrogates the majority of the transcriptional response in the bacterium, showing that pH is the dominant signal that the bacterium senses and responds to. These approaches represent our ongoing attempts to unravel the discourse that takes place between the pathogen and its host cell. | Mycobacterium tuberculosis and the environment within the phagosome. |
38076716 | We have developed a new generation of genome-wide DNA methylation BeadChip which allows high-throughput methylation profiling of the human genome. The new high density BeadChip can assay over 480K CpG sites and analyze twelve samples in parallel. The innovative content includes coverage of 99% of RefSeq genes with multiple probes per gene, 96% of CpG islands from the UCSC database, CpG island shores and additional content selected from whole-genome bisulfite sequencing data and input from DNA methylation experts. The well-characterized Infinium® Assay is used for analysis of CpG methylation using bisulfite-converted genomic DNA. We applied this technology to analyze DNA methylation in normal and tumor DNA samples and compared results with whole-genome bisulfite sequencing (WGBS) data obtained for the same samples. Highly comparable DNA methylation profiles were generated by the array and sequencing methods (average R2 of 0.95). The ability to determine genome-wide methylation patterns will rapidly advance methylation research. | High density DNA methylation array with single CpG site resolution. |
38127792 | In mitosis the cell assembles the bipolar spindle, a microtubule (MT)-based apparatus that segregates the duplicated chromosomes into two daughter cells. Most animal cells enter mitosis with duplicated centrosomes that provide an active source of dynamic MTs. However, it is now established that spindle assembly relies on the nucleation of acentrosomal MTs occurring around the chromosomes after nuclear envelope breakdown, and on pre-existing microtubules. Where chromosome-dependent MT nucleation occurs, when MT amplification takes place and how the two pathways function are still key questions that generate some controversies. We reconcile the data and present an integrated model accounting for acentrosomal microtubule assembly in the dividing cell. | Acentrosomal Microtubule Assembly in Mitosis: The Where, When, and How. |
38131471 | DNA damage is a relatively common event in the life of a cell and may lead to mutation, cancer, and cellular or organismic death. Damage to DNA induces several cellular responses that enable the cell either to eliminate or cope with the damage or to activate a programmed cell death process, presumably to eliminate cells with potentially catastrophic mutations. These DNA damage response reactions include: (a) removal of DNA damage and restoration of the continuity of the DNA duplex; (b) activation of a DNA damage checkpoint, which arrests cell cycle progression so as to allow for repair and prevention of the transmission of damaged or incompletely replicated chromosomes; (c) transcriptional response, which causes changes in the transcription profile that may be beneficial to the cell; and (d) apoptosis, which eliminates heavily damaged or seriously deregulated cells. DNA repair mechanisms include direct repair, base excision repair, nucleotide excision repair, double-strand break repair, and cross-link repair. The DNA damage checkpoints employ damage sensor proteins, such as ATM, ATR, the Rad17-RFC complex, and the 9-1-1 complex, to detect DNA damage and to initiate signal transduction cascades that employ Chk1 and Chk2 Ser/Thr kinases and Cdc25 phosphatases. The signal transducers activate p53 and inactivate cyclin-dependent kinases to inhibit cell cycle progression from G1 to S (the G1/S checkpoint), DNA replication (the intra-S checkpoint), or G2 to mitosis (the G2/M checkpoint). In this review the molecular mechanisms of DNA repair and the DNA damage checkpoints in mammalian cells are analyzed. | Molecular mechanisms of mammalian DNA repair and the DNA damage checkpoints. |
38143689 | Serotonin 5-HT2C receptors (5-HT(2C)Rs) are almost exclusively expressed in the CNS, and implicated in disorders such as obesity, depression, and schizophrenia. The present study investigated the mechanisms governing the coupling of the 5-HT(2C)R to the extracellular signal-regulated kinases (ERKs) 1/2, using a Chinese hamster ovary (CHO) cell line stably expressing the receptor at levels comparable to those found in the brain. Using the non-RNA-edited isoform of the 5-HT(2C)R, constitutive ERK1/2 phosphorylation was observed and found to be modulated by full, partial and inverse agonists. Interestingly, agonist-directed trafficking of receptor stimulus was also observed when comparing effects on phosphoinositide accumulation and intracellular Ca2+ elevation to ERK1/2 phosphorylation, whereby the agonists, [+/-]-2,5-dimethoxy-4-iodoamphetamine (DOI) and quipazine, showed reversal of efficacy between the phosphoinositide/Ca2+ pathways, on the one hand, and the ERK1/2 pathway on the other. Subsequent molecular characterization found that 5-HT-stimulated ERK1/2 phosphorylation in this cellular background requires phospholipase D, protein kinase C, and activation of the Raf/MEK/ERK module, but is independent of both receptor- and non-receptor tyrosine kinases, phospholipase C, phosphoinositide 3-kinase, and endocytosis. Our findings underscore the potential for exploiting pathway-selective receptor states in the differential modulation of signaling pathways that play prominent roles in normal and abnormal neuronal signaling. | Characterization of serotonin 5-HT2C receptor signaling to extracellular signal-regulated kinases 1 and 2. |
38180456 | Short-term medical service trips (MSTs) aim to address unmet health care needs of low- and middle-income countries. The lack of critically reviewed empirical evidence of activities and outcomes is a concern. Developing evidence-based recommendations for health care delivery requires systematic research review. I focused on MST publications with empirical results. Searches in May 2013 identified 67 studies published since 1993, only 6% of the published articles on the topic in the past 20 years. Nearly 80% reported on surgical trips. Although the MST field is growing, its medical literature lags behind, with nearly all of the scholarly publications lacking significant data collection. By incorporating data collection into service trips, groups can validate practices and provide information about areas needing improvement. | Short-term medical service trips: a systematic review of the evidence. |
38211681 | The amended (revised) Beck Depression Inventory (BDI-IA; Beck & Steer, 1993b) and the Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996) were self-administered to 140 psychiatric outpatients with various psychiatric disorders. The coefficient alphas of the BDI-IA and the BDI-II were, respectively, .89 and .91. The mean rating for Sadness on the BDI-IA was higher than it was on the BDI-II, but the mean ratings for Past Failure, Self-Dislike, Change in Sleeping Pattern, and Change in Appetite were higher on the BDI-II than they were on the BDI-IA. The mean BDI-II total score was approximately 2 points higher than it was for the BDI-IA, and the outpatients also endorsed approximately one more symptom on the BDI-II than they did on the BDI-IA. The correlations of BDI-IA and BDI-II total scores with sex, ethnicity, age, the diagnosis of a mood disorder, and the Beck Anxiety Inventory (Beck & Steer, 1993a) were within 1 point of each other for the same variables. | Comparison of Beck Depression Inventories -IA and -II in psychiatric outpatients. |
38243984 | PURPOSE The goal of this study was to evaluate prospectively the engraftment rate, factors influencing engraftment, and predictability of clinical outcome of low-passage xenografts from patients with resectable pancreatic ductal adenocarcinoma (PDA) and to establish a bank of PDA xenografts. EXPERIMENTAL DESIGN Patients with resectable PDA scheduled for resection at the Johns Hopkins Hospital were eligible. Representative pieces of tumor were implanted in nude mice. The status of the SMAD4 gene and content of tumor-generating cells were determined by immunohistochemistry. Gene expression was carried out by using a U133 Plus 2.0 array. Patients were followed for progression and survival.
RESULTS A total of 94 patients with PDA were resected, 69 tumors implanted in nude mice, and 42 (61%) engrafted. Engrafted carcinomas were more often SMAD4 mutant, and had a metastatic gene expression signature and worse prognosis. Tumors from patients resistant to gemcitabine were enriched in stroma-related gene pathways. Tumors sensitive to gemcitabine were enriched in cell cycle and pyrimidine gene pathways. The time to progression for patients who received treatment with gemcitabine for metastatic disease (n = 7) was double in patients with xenografts sensitive to gemcitabine.
CONCLUSION A successful xenograft was generated in 61% of patients attempted, generating a pool of 42 PDA xenografts with significant biological information and annotated clinical data. Patients with PDA and SMAD4 inactivation have a better engraftment rate. Engraftment is a poor prognosis factor, and engrafted tumors have a metastatic gene expression signature. Tumors from gemcitabine-resistant patients were enriched in stromal pathways. | Tumor engraftment in nude mice and enrichment in stroma- related gene pathways predict poor survival and resistance to gemcitabine in patients with pancreatic cancer. |
38252314 | The minichromosome maintenance protein homologs MCM8 and MCM9 have previously been implicated in DNA replication elongation and prereplication complex (pre-RC) formation, respectively. We found that MCM8 and MCM9 physically associate with each other and that MCM8 is required for the stability of MCM9 protein in mammalian cells. Depletion of MCM8 or MCM9 in human cancer cells or the loss of function MCM9 mutation in mouse embryo fibroblasts sensitizes cells to the DNA interstrand cross-linking (ICL) agent cisplatin. Consistent with a role in the repair of ICLs by homologous recombination (HR), knockdown of MCM8 or MCM9 significantly reduces HR repair efficiency. Chromatin immunoprecipitation analysis using human DR-GFP cells or Xenopus egg extract demonstrated that MCM8 and MCM9 proteins are rapidly recruited to DNA damage sites and promote RAD51 recruitment. Thus, these two metazoan-specific MCM homologs are new components of HR and may represent novel targets for treating cancer in combination with DNA cross-linking agents. | The MCM8-MCM9 complex promotes RAD51 recruitment at DNA damage sites to facilitate homologous recombination. |
38296571 | The present invention provides a combination sink and dishwashing apparatus having a sink sharing a common side wall with a cabinet which defines a closed space. The cabinet has a wire basket for holding and washing a plurality of dishes within the cabinet. The common side wall is a part of the cabinet that defines the closed space and is positioned to form one side of the sink. The common side wall can be opened to allow the wire basket to slide from within the cabinet and into the sink, for loading and unloading the dishes. Within the cabinet, the invention contains a pump powered by a motor, the pump spraying water through a rotatably mounted spray arm onto the dishes to wash them, as with traditional dishwashing machines. The invention preferably includes a garbage disposal which is also powered by the motor. In an alternative embodiment, this invention can include two cabinets as described above, each located on opposing sides of the sink. | The 5TMM series: a useful in vivo mouse model of human multiple myeloma. |
38300781 | Phospholipids are the major components of cell membranes, but they have functional roles beyond forming lipid bilayers. In particular, acidic phospholipids form microdomains in the plasma membrane and can ionically interact with proteins via polybasic sequences, which can have functional consequences for the protein. The list of proteins regulated by ionic protein-lipid interaction has been quickly expanding, and now includes membrane proteins, cytoplasmic soluble proteins, and viral proteins. Here we review how acidic phospholipids in the plasma membrane regulate protein structure and function via ionic interactions, and how Ca(2+) regulates ionic protein-lipid interactions via direct and indirect mechanisms. | Ionic protein-lipid interaction at the plasma membrane: what can the charge do? |
38355793 | OBJECTIVE A20 is a TNF-inducible primary response gene, which has been found to have antiapoptotic function in several cancer cells. This study investigates A20 expression in human glioma tissues and four glioma cell lines, and its effect on tumorigenesis of glioma cells and a mouse tumor model.
METHODS Human glioma tissue samples and cells were subject to reverse transcription-PCR (RT-PCR), western blotting and immunohistochemistry. Glioma cells was tested by flow cytometry. A xenograft tumor model in mice was utilized to examine the knock-down effect of specific A20 siRNAs on tumorigenesis.
RESULTS A20 was overexpressed in clinical glioma tissue samples (63.9%) and correlated with clinical staging. All four human glioma cell lines expressed A20, among which U87 displayed the strongest expression signals. Inhibiting A20 expression by siRNAs in vitro reduced the growth rates of glioma cells and resulted in G1/S arrest and increased apoptosis. In a mouse tumor model, local administration of siRNA significantly suppressed solid tumor growth.
CONCLUSIONS A20 was overexpressed both in human glioma tissues and cell lines, and inhibiting A20 expression greatly slowed tumor cell growth in culture and in mice. These findings indicated that A20 is involved in tumorigenesis of human glioma, and may serve as a future therapeutic target. | A20 is overexpressed in glioma cells and may serve as a potential therapeutic target. |
38369817 | BACKGROUND Transcranial contrast Doppler studies have shown an increased prevalence of right-to-left shunts in patients with migraine with aura compared with controls. The anatomy and size of these right-to-left shunts have never been directly assessed.
METHODS In a cross-sectional case-control study, the authors performed transesophageal contrast echocardiography in 93 consecutive patients with migraine with aura and 93 healthy controls.
RESULTS A patent foramen ovale was present in 44 (47% [95% CI 37 to 58%]) patients with migraine with aura and 16 (17% [95% CI 10 to 26%]) control subjects (OR 4.56 [95% CI 1.97 to 10.57]; p < 0.001). A small shunt was equally prevalent in migraineurs (10% [95% CI 5 to 18%]) and controls (10% [95% CI 5 to 18%]), but a moderate-sized or large shunt was found more often in the migraine group (38% [95% CI 28 to 48%] vs 8% [95% CI 2 to 13%] in controls; p < 0.001). The presence of more than a small shunt increased the odds of having migraine with aura 7.78-fold (95% CI 2.53 to 29.30; p < 0.001). Besides patent foramen ovale prevalence and shunt size, no other echocardiographic differences were found between the study groups. Headache and baseline characteristics did not differ in migraine patients with and without shunt.
CONCLUSIONS Nearly half of all patients with migraine with aura have a right-to-left shunt due to a patent foramen ovale. Shunt size is larger in migraineurs than controls. The clinical presentation of migraine is identical in patients with and without a patent foramen ovale. | Prevalence and size of directly detected patent foramen ovale in migraine with aura. |
38376189 | West Nile virus (WNV) is a major cause of mosquito-borne illness in the United States. Human disease ranges from mild febrile illness to severe fatal neurologic infection. Adults aged >60 years are more susceptible to neuroinvasive disease accompanied by a high mortality rate or long-lasting neurologic sequelae. A chimeric live attenuated West Nile virus vaccine, rWN/DEN4&Dgr;30, was shown to be safe and immunogenic in healthy adults aged 18–50 years. This study evaluated rWN/DEN4&Dgr;30 in flavivirus-naive adults aged 50–65 years and found it to be safe and immunogenic. Outbreaks of WNV infection tend to be unpredictable, and a safe and effective vaccine will be an important public health tool. | A Live Attenuated Chimeric West Nile Virus Vaccine, rWN/DEN4&Dgr;30, Is Well Tolerated and Immunogenic in Flavivirus-Naive Older Adult Volunteers |
38380061 | As organisms develop, their tissues can become separated into distinct cell populations through the establishment of compartment boundaries. Compartment boundaries have been discovered in a wide variety of tissues, but in many cases the molecular mechanisms that separate cells remain poorly understood. In the Drosophila wing, a stripe of Notch activation maintains the dorsal-ventral compartment boundary, through a process that depends on the actin cytoskeleton. Here, we show that the dorsal-ventral boundary exhibits a distinct accumulation of Myosin II, and that this accumulation is regulated downstream of Notch signaling. Conversely, the dorsal-ventral boundary is depleted for the Par-3 homologue Bazooka. We further show that mutations in the Myosin heavy chain subunit encoded by zipper can impair dorsal-ventral compartmentalization without affecting anterior-posterior compartmentalization. These observations identify a distinct accumulation and requirement for Myosin activity in dorsal-ventral compartmentalization, and suggest a novel mechanism in which contractile tension along an F-actin cable at the compartment boundary contributes to compartmentalization. | Localization and requirement for Myosin II at the dorsal-ventral compartment boundary of the Drosophila wing. |
38401028 | 1. The changes in the metabolite content in freeze-clamped livers of fed rats occurring on perfusion with 10mm-d-fructose have been examined. 2. The most striking effects of fructose were an accumulation of fructose 1-phosphate, as already known, up to 8.7mumol/g of liver within 10min, a loss of total adenine nucleotides (up to 35% after 40min) with a decrease in the ATP content to 23% within 10min, a sevenfold rise in the concentration of IMP to 1.1mumol/g and an eightfold rise of alpha-glycerophosphate to 1.1mumol/g. 3. There was a transient decrease in P(i) from 4.2 to 1.7mumol/g. Within 40min the P(i) content recovered to the normal value, probably because of an uptake of P(i) from the perfusion medium. 4. The degradation of the adenine nucleotides beyond the stage of AMP can be accounted for by the decrease of ATP and P(i). As ATP inhibits 5-nucleotidase, and as P(i) inhibits AMP deaminase any AMP arising in the tissue is liable to undergo dephosphorylation or deamination under the conditions occurring after fructose loading. 5. The content of lactate increased to 4.3mumol/g at 80min; pyruvate also increased and the [lactate]/[pyruvate] ratio remained within physiological limits. 6. The concentration of free fructose within the liver remained much below that in the perfusion medium, indicating that the rate of penetration of fructose into the tissue was lower than the rate of utilization. 7. The fission of fructose 1-phosphate by liver aldolase is inhibited by several phosphorylated intermediates, especially by IMP. This inhibition is competitive with a K(i) of 0.1mm. 8. The maximal rates of the enzymes synthesizing and splitting fructose 1-phosphate are about equal. The accumulation of fructose 1-phosphate on fructose loading is due to the inhibition of the fission of fructose 1-phosphate by the IMP arising from the degradation of the adenine nucleotides. | The cause of hepatic accumulation of fructose 1-phosphate on fructose loading. |
38410121 | BACKGROUND The aim of the study was to provide data on the relative frequency of reported symptoms in travelers using chloroquine, chloroquine plus proguanil, and mefloquine.
METHOD The study was an open, nonrandomized study recording self-reported events in travelers recruited consecutively from two travel clinics in Copenhagen, Denmark. The main outcome measures were the relative proportion of travelers reporting particular symptoms in the three prophylaxis groups, compliance, hospitalization and premature termination of the travel.
RESULTS From May 1996 to April 1998 5, 446 travelers were included and 4,158 questionnaires (76.3%) returned. Compliance was significantly better in mefloquine users with 83.3% of short term travelers compared to 76.3% in chloroquine plus proguanil users. Also, 84.8%, 59.3% and 69.5% using chloroquine, chloroquine plus proguanil, and mefloquine respectively reported no symptoms and 0.6%, 1.1% and 2.8% reported "unacceptable" symptoms. Compared to chloroquine, mefloquine users had a significantly higher risk of reporting depression, RR 5.06 (95% CI 2.71 - 9.45), "strange thoughts," RR 6.36 (95% CI 2.52 - 16.05) and altered spatial perception, RR 3.00 (95% CI 1.41 - 6.41).
CONCLUSION Overall mefloquine is tolerated at least as well as chloroquine plus proguanil and shows better compliance, however, symptoms related to the central nervous system are more prevalent in mefloquine users and when symptoms develop, they are perceived as more severe. | Reported side effects to chloroquine, chloroquine plus proguanil, and mefloquine as chemoprophylaxis against malaria in Danish travelers. |
38477436 | Human cytomegalovirus US2 and US11 target newly synthesized class I major histocompatibility complex (MHC) heavy chains for rapid degradation by the proteasome through a process termed dislocation. The presence of US2 induces the formation of class I MHC heavy chain conjugates of increased molecular weight that are recognized by a conformation-specific monoclonal antibody, W6/32, suggesting that these class I MHC molecules retain their proper tertiary structure. These conjugates are properly folded glycosylated heavy chains modified by attachment of an estimated one, two, and three ubiquitin molecules. The folded ubiquitinated class I MHC heavy chains are not observed in control cells or in cells transfected with US11, suggesting that US2 targets class I MHC heavy chains for dislocation in a manner distinct from that used by US11. This is further supported by the fact that US2 and US11 show different requirements in terms of the conformation of the heavy chain molecule. Although ubiquitin conjugation may occur on the cytosolic tail of the class I MHC molecule, replacement of lysines in the cytosolic tail of heavy chains with arginine does not prevent their degradation by US2. In an in vitro system that recapitulates US2-mediated dislocation, heavy chains that lack these lysines still occur in an ubiquitin-modified form, but in the soluble (cytoplasmic) fraction. Such ubiquitin conjugation can only occur on the class I MHC lumenal domain and is likely to take place once class I MHC heavy chains have been discharged from the endoplasmic reticulum. We conclude that ubiquitinylation of class I MHC heavy chain is not required during the initial step of the US2-mediated dislocation reaction. | Ubiquitinylation of the cytosolic domain of a type I membrane protein is not required to initiate its dislocation from the endoplasmic reticulum. |
38485364 | Tks5/Fish is a scaffolding protein with five SH3 domains and one PX domain. In Src-transformed cells, Tks5/Fish localizes to podosomes, discrete protrusions of the ventral membrane. We generated Src-transformed cells with reduced Tks5/Fish levels. They no longer formed podosomes, did not degrade gelatin, and were poorly invasive. We detected Tks5/Fish expression in podosomes in invasive cancer cells, as well as in human breast cancer and melanoma samples. Tks5/Fish expression was also required for protease-driven matrigel invasion in human cancer cells. Finally, coexpression of Tks5/Fish and Src in epithelial cells resulted in the appearance of podosomes. Thus, Tks5/Fish appears to be required for podosome formation, for degradation of the extracellular matrix, and for invasion of some cancer cells. | The adaptor protein Tks5/Fish is required for podosome formation and function, and for the protease-driven invasion of cancer cells. |
38493521 | BACKGROUND While many treatments, including corticosteroid injections in and around the shoulder, are advocated to be of benefit for shoulder pain, few are of proven efficacy. This review of corticosteroid injections for shoulder pain is one in a series of reviews of varying interventions for shoulder disorders.
OBJECTIVES To determine the efficacy and safety of corticosteroid injections in the treatment of adults with shoulder pain. SEARCH STRATEGY MEDLINE, EMBASE, CINAHL, Central and Science Citation Index were searched up to and including June 2002. SELECTION CRITERIA Randomised and pseudo-randomised trials in all languages of corticosteroid injections compared to placebo or another intervention, or of varying types and dosages of steroid injection in adults with shoulder pain. Specific exclusions were duration of shoulder pain less than three weeks, rheumatoid arthritis, polymyalgia rheumatica and fracture.
DATA COLLECTION AND ANALYSIS Trial inclusion and methodological quality was assessed by two independent reviewers according to predetermined criteria. Results are presented separately for rotator cuff disease, adhesive capsulitis, full thickness rotator cuff tear and mixed diagnoses, and, where possible, combined in meta-analysis.
MAIN RESULTS Twenty-six trials met inclusion criteria. The number, site and dosage of injections varied widely between studies. The number of participants per trial ranged from 20 to 114 (median 52 participants). Methodological quality was variable. For rotator cuff disease, subacromial steroid injection was demonstrated to have a small benefit over placebo in some trials however no benefit of subacromial steroid injection over NSAID was demonstrated based upon the pooled results of three trials. For adhesive capsulitis, two trials suggested a possible early benefit of intra-articular steroid injection over placebo but there was insufficient data for pooling of any of the trials. One trial suggested short-term benefit of intra-articular corticosteroid injection over physiotherapy in the short-term (success at seven weeks RR=1.66 (1.21, 2.28). REVIEWER'S CONCLUSIONS Despite many RCTs of corticosteroid injections for shoulder pain, their small sample sizes, variable methodological quality and heterogeneity means that there is little overall evidence to guide treatment. Subacromial corticosteroid injection for rotator cuff disease and intra-articular injection for adhesive capsulitis may be beneficial although their effect may be small and not well-maintained. There is a need for further trials investigating the efficacy of corticosteroid injections for shoulder pain. Other important issues that remain to be clarified include whether the accuracy of needle placement, anatomical site, frequency, dose and type of corticosteroid influences efficacy. | Corticosteroid injections for shoulder pain. |
38502066 | Thymic-derived natural T regulatory cells (Tregs) are characterized by functional and phenotypic heterogeneity. Recently, a small fraction of peripheral Tregs has been shown to express Klrg1, but it remains unclear as to what extent Klrg1 defines a unique Treg subset. In this study, we show that Klrg1(+) Tregs represent a terminally differentiated Treg subset derived from Klrg1(-) Tregs. This subset is a recent Ag-responsive and highly activated short-lived Treg population that expresses enhanced levels of Treg suppressive molecules and that preferentially resides within mucosal tissues. The development of Klrg1(+) Tregs also requires extensive IL-2R signaling. This activity represents a distinct function for IL-2, independent from its contribution to Treg homeostasis and competitive fitness. These and other properties are analogous to terminally differentiated short-lived CD8(+) T effector cells. Our findings suggest that an important pathway driving Ag-activated conventional T lymphocytes also operates for Tregs. | IL-2 receptor signaling is essential for the development of Klrg1+ terminally differentiated T regulatory cells. |
38528892 | The kinetochore is the macromolecular protein complex that mediates chromosome segregation. The Dsn1 component is crucial for kinetochore assembly and is phosphorylated by the Aurora B kinase. We found that Aurora B phosphorylation of Dsn1 promotes the interaction between outer and inner kinetochore proteins in budding yeast. | The aurora B kinase promotes inner and outer kinetochore interactions in budding yeast. |
38533515 | The SNF1/AMP-activated protein kinase (AMPK) family maintains the balance between ATP production and consumption in all eukaryotic cells. The kinases are heterotrimers that comprise a catalytic subunit and regulatory subunits that sense cellular energy levels. When energy status is compromised, the system activates catabolic pathways and switches off protein, carbohydrate and lipid biosynthesis, as well as cell growth and proliferation. Surprisingly, recent results indicate that the AMPK system is also important in functions that go beyond the regulation of energy homeostasis, such as the maintenance of cell polarity in epithelial cells. | AMP-activated/SNF1 protein kinases: conserved guardians of cellular energy |
38551172 | Mammographic density is a strong risk factor for breast cancer, but the underlying biology for this association is unknown. Studies suggest that vitamin D may reduce breast cancer risk and dietary vitamin D intake has been associated with reduced breast density. We conducted a case-control study nested within the Nurses' Health Study cohort consisting of 463 and 497 postmenopausal cases and controls, respectively. We examined the association between mammographic density and plasma levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. We assessed whether plasma vitamin D metabolites modify the association between breast density and breast cancer. Percent mammographic density was measured from digitized film mammograms. Generalized linear models were used to determine mean percent breast density per quartile of vitamin D metabolite. Logistic regression models were used to calculate relative risks and confidence intervals. All models were adjusted for matching variables and potential confounders. We found no cross-sectional association between circulating levels of 25(OH)D or 1,25(OH)(2)D with mammographic density. Women in the highest tertile of mammographic density and lowest tertile of plasma 25(OH)D had 4 times greater risk of breast cancer than women with the lowest mammographic density and highest plasma 25(OH)D levels (RR = 3.8; 95% CI: 2.0-7.3). The overall interaction between mammographic density and plasma 25(OH)D was nonsignificant (p-het = 0.20). These results indicate that the association between mammographic density and breast cancer is independent of plasma vitamin D metabolites in postmenopausal women. Further research examining vitamin D, mammographic density and breast cancer risk is warranted. | Mammographic density, plasma vitamin D levels and risk of breast cancer in postmenopausal women. |
38587347 | Humoral immune responses depend on B cells encountering antigen, interacting with helper T cells, proliferating and differentiating into low-affinity plasma cells or, after organizing into a germinal center (GC), high-affinity plasma cells and memory B cells. Remarkably, each of these events occurs in association with distinct stromal cells in separate subcompartments of the lymphoid tissue. B cells must migrate from niche to niche in a rapid and highly regulated manner to successfully mount a response. The chemokine, CXCL13, plays a central role in guiding B cells to follicles whereas T-zone chemokines guide activated B cells to the T zone. Sphingosine-1-phosphate (S1P) promotes cell egress from the tissue, as well as marginal-zone B-cell positioning in the spleen. Recent studies have identified a role for the orphan receptor, EBV-induced molecule 2 (EBI2; GPR183), in guiding activated B cells to inter and outer follicular niche(s) and down-regulation of this receptor is essential for organizing cells into GCs. In this review, we discuss current understanding of the roles played by chemokines, S1P and EBI2 in the migration events that underlie humoral immune responses. | Finding the right niche: B-cell migration in the early phases of T-dependent antibody responses. |
38623601 | Autophagy is the principal catabolic response to nutrient starvation and is necessary to clear dysfunctional or damaged organelles, but excessive autophagy can be cytotoxic or cytostatic and contributes to cell death. Depending on the abundance of enzymes involved in molecule biosynthesis, cells can be dependent on uptake of exogenous nutrients to provide these molecules. Argininosuccinate synthetase 1 (ASS1) is a key enzyme in arginine biosynthesis, and its abundance is reduced in many solid tumors, making them sensitive to external arginine depletion. We demonstrated that prolonged arginine starvation by exposure to ADI-PEG20 (pegylated arginine deiminase) induced autophagy-dependent death of ASS1-deficient breast cancer cells, because these cells are arginine auxotrophs (dependent on uptake of extracellular arginine). Indeed, these breast cancer cells died in culture when exposed to ADI-PEG20 or cultured in the absence of arginine. Arginine starvation induced mitochondrial oxidative stress, which impaired mitochondrial bioenergetics and integrity. Furthermore, arginine starvation killed breast cancer cells in vivo and in vitro only if they were autophagy-competent. Thus, a key mechanism underlying the lethality induced by prolonged arginine starvation was the cytotoxic autophagy that occurred in response to mitochondrial damage. Last, ASS1 was either low in abundance or absent in more than 60% of 149 random breast cancer biosamples, suggesting that patients with such tumors could be candidates for arginine starvation therapy. | Arginine Starvation Impairs Mitochondrial Respiratory Function in ASS1-Deficient Breast Cancer Cells |
38630735 | BACKGROUND Atherosclerotic plaques that lead to acute coronary syndromes often occur at sites of angiographically mild coronary-artery stenosis. Lesion-related risk factors for such events are poorly understood.
METHODS In a prospective study, 697 patients with acute coronary syndromes underwent three-vessel coronary angiography and gray-scale and radiofrequency intravascular ultrasonographic imaging after percutaneous coronary intervention. Subsequent major adverse cardiovascular events (death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalization due to unstable or progressive angina) were adjudicated to be related to either originally treated (culprit) lesions or untreated (nonculprit) lesions. The median follow-up period was 3.4 years.
RESULTS The 3-year cumulative rate of major adverse cardiovascular events was 20.4%. Events were adjudicated to be related to culprit lesions in 12.9% of patients and to nonculprit lesions in 11.6%. Most nonculprit lesions responsible for follow-up events were angiographically mild at baseline (mean [±SD] diameter stenosis, 32.3±20.6%). However, on multivariate analysis, nonculprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of 70% or greater (hazard ratio, 5.03; 95% confidence interval [CI], 2.51 to 10.11; P<0.001) or a minimal luminal area of 4.0 mm(2) or less (hazard ratio, 3.21; 95% CI, 1.61 to 6.42; P=0.001) or to be classified on the basis of radiofrequency intravascular ultrasonography as thin-cap fibroatheromas (hazard ratio, 3.35; 95% CI, 1.77 to 6.36; P<0.001).
CONCLUSIONS In patients who presented with an acute coronary syndrome and underwent percutaneous coronary intervention, major adverse cardiovascular events occurring during follow-up were equally attributable to recurrence at the site of culprit lesions and to nonculprit lesions. Although nonculprit lesions that were responsible for unanticipated events were frequently angiographically mild, most were thin-cap fibroatheromas or were characterized by a large plaque burden, a small luminal area, or some combination of these characteristics, as determined by gray-scale and radiofrequency intravascular ultrasonography. (Funded by Abbott Vascular and Volcano; ClinicalTrials.gov number, NCT00180466.). | A prospective natural-history study of coronary atherosclerosis. |
38664102 | PURPOSE To examine the curricula of U.S. medical schools to assess the inclusion of women's health and gender-specific information and identify institutional characteristics associated with this content.
METHOD Using data from the Association of American Medical Colleges' Curriculum Management and Information Tool (CurrMIT), in November 2003 to February 2004 the authors performed a curriculum search of schools that entered course/clerkships in CurrMIT to identify interdisciplinary women's health or gender-specific courses/clerkships. A subset of schools that entered comprehensive information in CurrMIT was searched for a specified list of women's health topics and or gender-specific content on any topic. Statistical analyses were performed to assess the relationship between frequency of topics and school characteristics.
RESULTS The authors identified 95 schools that entered related courses/clerkships. Ten courses/clerkships at nine schools met criteria for an interdisciplinary women's health course/clerkship. In the subset of 60 schools with comprehensive CurrMIT information, 18 specified women's health topics were identified, as well as 24 topics on gender-specific content, for a total of 42 topics. The number of topics taught ranged from zero to 26 (mean = 11). More than 50% of these schools taught 11 of the 18 specified topics, while fewer than 30% included gender-specific topics. There was no association in bivariate analysis between the mean number of topics taught and schools' characteristics; however, a women's health program (p= .01) and female dean (p= .06) were positively associated in a regression model.
CONCLUSIONS Few schools offer interdisciplinary women's health courses/clerkships or include gender-specific information in their curricula. A designated women's health program may increase this content in schools' curricula. | What do medical schools teach about women's health and gender differences? |
38675228 | Plants and some animals have a profound capacity to regenerate organs from adult tissues. Molecular mechanisms for regeneration have, however, been largely unexplored. Here we investigate a local regeneration response in Arabidopsis roots. Laser-induced wounding disrupts the flow of auxin-a cell-fate-instructive plant hormone-in root tips, and we demonstrate that resulting cell-fate changes require the PLETHORA, SHORTROOT, and SCARECROW transcription factors. These transcription factors regulate the expression and polar position of PIN auxin efflux-facilitating membrane proteins to reconstitute auxin transport in renewed root tips. Thus, a regeneration mechanism using embryonic root stem-cell patterning factors first responds to and subsequently stabilizes a new hormone distribution. | A molecular framework for plant regeneration. |
38712515 | Evidence suggests that certain flavan-3-ols and procyanidins (FP) can have a positive influence on cardiovascular health. It has been previously reported that FP isolated from cocoa can potentially modulate the level and production of several signaling molecules associated with immune function and inflammation, including several cytokines and eicosanoids. In the present study, we examined whether FP fractions monomers through decamers modulate secretion of the cytokine transforming growth factor (TGF)-beta(1) from resting human peripheral blood mononuclear cells (PBMC). A total of 13 healthy subjects were studied and grouped according to their baseline production of TGF-beta(1). When cells from individuals with low baseline levels of TGF-beta(1) (n = 7) were stimulated by individual FP fractions (25 microg/ml), TGF-beta(1) release was enhanced in the range of 15%-66% over baseline (P < 0.05; monomer, dimer, and tetramer). The low-molecular-weight FP fractions (<or=pentamer) were more effective at augmenting TGF-beta(1) secretion than their larger counterparts (>or=hexamer), with the monomer and dimer inducing the greatest increases (66% and 68%, respectively). In contrast to the above, TGF-beta(1) secretion from high TGF-beta(1) baseline subjects (n = 6) was inhibited by individual FP fractions (P < 0.05; trimer through decamer). The inhibition was most pronounced with trimeric through decameric fractions (28%-42%), and monomers and dimers moderately inhibited TGF-beta(1) release (17% and 23%, respectively). Given the vascular actions associated with TGF-beta(1), we suggest that in healthy individuals, homeostatic modulation of its production by FP offers an additional mechanism by which FP-rich foods can potentially benefit cardiovascular health. | Cocoa flavonols and procyanidins promote transforming growth factor-beta1 homeostasis in peripheral blood mononuclear cells. |
38727075 | The neural crest is a multipotent, migratory cell population arising from the border of the neural and surface ectoderm. In mouse, the initial migratory neural crest cells occur at the five-somite stage. Bone morphogenetic proteins (BMPs), particularly BMP2 and BMP4, have been implicated as regulators of neural crest cell induction, maintenance, migration, differentiation and survival. Mouse has three known BMP2/4 type I receptors, of which Bmpr1a is expressed in the neural tube sufficiently early to be involved in neural crest development from the outset; however, earlier roles in other domains obscure its requirement in the neural crest. We have ablated Bmpr1a specifically in the neural crest, beginning at the five-somite stage. We find that most aspects of neural crest development occur normally; suggesting that BMPRIA is unnecessary for many aspects of early neural crest biology. However, mutant embryos display a shortened cardiac outflow tract with defective septation, a process known to require neural crest cells and to be essential for perinatal viability. Surprisingly, these embryos die in mid-gestation from acute heart failure, with reduced proliferation of ventricular myocardium. The myocardial defect may involve reduced BMP signaling in a novel, minor population of neural crest derivatives in the epicardium, a known source of ventricular myocardial proliferation signals. These results demonstrate that BMP2/4 signaling in mammalian neural crest derivatives is essential for outflow tract development and may regulate a crucial proliferation signal for the ventricular myocardium. | BMP receptor IA is required in mammalian neural crest cells for development of the cardiac outflow tract and ventricular myocardium. |
38735355 | Alveolar hypoxia and hypoxic vasoconstriction lead to trapping of sickle cells within the pulmonary vasculature. Improving alveolar ventilation and oxygenation may improve the outcome of acute chest syndrome (ACS). Prospective randomized single-center open study from November 1998 to February 2002 to test whether noninvasive ventilation (NIV) was more effective than oxygen alone in improving oxygenation on day 3 in adults with ACS and to evaluate the effects on pain, transfusion requirements, and length of stay. Seventy-one consecutive ACS episodes in 67 patients were randomly allocated to oxygen (n = 36) or NIV (n = 35) for 3 days in a medical step-down unit. Baseline respiratory rate and pain score were higher in the NIV group. NIV promptly lowered the respiratory rate, raised $$ {\text{Pa}}_{{\text{O}_{2}}} $$ , and decreased alveolar–arterial oxygen gradient $$ (({\text{A}} - {\text{a}})_{{{\text{O}}_{ 2} }} ) $$ , which remained unchanged with oxygen alone. $$ {\text{Pa}}_{{{\text{CO}}_{ 2} }} $$ significantly worsened only in the oxygen group. On day 3, the groups did not differ regarding the proportion of episodes with normal $$ {\text{Pa}}_{{{\text{O}}_{ 2} }} $$ (35% with NIV and 25% with oxygen; P = 0.5) or $$ (({\text{A}} - {\text{a}})_{{{\text{O}}_{ 2} }} ) $$ . Patient satisfaction and compliance were lower with NIV. No differences were noted in pain relief, transfusions, or length of stay. In the subgroup of patients with severe hypoxemia $$ ( {\text{Pa}}_{{{\text{O}}_{ 2} }} \le 6 5\,{\text{mmHg)}} $$ , physiological variables also improved faster with NIV, the differences being slightly more pronounced. Respiratory rate and gas exchange improved faster with NIV. However, NIV failed to significantly reduce the number of patients remaining hypoxemic at day 3, and was associated with greater patient discomfort. | Early intermittent noninvasive ventilation for acute chest syndrome in adults with sickle cell disease: a pilot study |
38745690 | Relapse remains the major cause of mortality for patients with Acute Myeloid Leukemia (AML). Improved tracking of minimal residual disease (MRD) holds the promise of timely treatment adjustments to preempt relapse. Current surveillance techniques detect circulating blasts that coincide with advanced disease and poorly reflect MRD during early relapse. Here, we investigate exosomes as a minimally invasive platform for a microRNA (miRNA) biomarker. We identify a set of miRNA enriched in AML exosomes and track levels of circulating exosome miRNA that distinguish leukemic xenografts from both non-engrafted and human CD34+ controls. We develop biostatistical models that reveal circulating exosomal miRNA at low marrow tumor burden and before circulating blasts can be detected. Remarkably, both leukemic blasts and marrow stroma contribute to serum exosome miRNA. We propose development of serum exosome miRNA as a platform for a novel, sensitive compartment biomarker for prospective tracking and early detection of AML recurrence. | Serum Exosome MicroRNA as a Minimally-Invasive Early Biomarker of AML |
38747567 | Clinical and low passage strains of human CMV (HCMV) encode an additional MHC class I-related molecule UL142, in addition to the previously described UL18. The UL142 open reading frame is encoded within the ULb' region which is missing from a number of common high passage laboratory strains. Cells expressing UL142 following transfection, and fibroblasts infected with a recombinant adenovirus-expressing UL142, were used to screen both polyclonal NK cells and NK cell clones, in a completely autologous system. Analysis of 100 NK cell clones derived from five donors, revealed 23 clones that were inhibited by fibroblasts expressing UL142 alone. Small-interfering RNA-mediated knockdown of UL142 mRNA expression in HCMV-infected cells resulted in increased sensitivity to lysis. From these data we conclude that UL142 is a novel HCMV-encoded MHC class I-related molecule which inhibits NK cell killing in a clonally dependent manner. | Human cytomegalovirus encodes an MHC class I-like molecule (UL142) that functions to inhibit NK cell lysis. |
38751591 | The DELLA proteins GAI, RGA, RGL1 and RGL2 in Arabidopsis are plant growth repressors, repressing diverse developmental processes. Studies have shown that gibberellin (GA) attenuates the repressive function of DELLA proteins by triggering their degradation via the proteasome pathway. However, it is not known if GA-induced protein degradation is the only pathway for regulating the bioactivity of DELLA proteins. We show here that tobacco BY2 cells represent a suitable system for studying GA signaling. RGL2 exists in a phosphorylated form in BY2 cells. RGL2 undergoes GA-induced degradation, and this process is blocked by proteasome inhibitors and serine/threonine phosphatase inhibitors; however, serine/threonine kinase inhibitors had no detectable effect, suggesting that dephosphorylation of serine/threonine is probably a prerequisite for degradation of RGL2 via the proteasome pathway. Site-directed substitution of all 17 conserved serine and threonine residues showed that six mutants (RGL2(S441D, RGL2(S542D), RGL2(T271E), RGL2(T319E), RGL2(T411E) and RGL2(T535E)) mimicking the status of constitutive phosphorylation are resistant to GA-induced degradation. This suggests that these sites are potential phosphorylation sites. A functional assay based on the expression of GA 20-oxidase revealed that RGL2(T271E) is probably a null mutant, RGL2(S441D), RGL2(S542D), RGL2(T319E) and RGL2(T411E) only retained about 4-17% of the activity of the wild type RGL2, whereas RGL2(T535E) retained about 66% of the activity of the wild type RGL2. However, expression of GA 20-oxidase in BY2 cells expressing these mutant proteins is still responsive to GA, suggesting that the stabilization of RGL2 protein is not the only pathway for regulating its bioactivity. | Identification of the conserved serine/threonine residues important for gibberellin-sensitivity of Arabidopsis RGL2 protein. |
38752049 | Youths with attention deficit hyperactivity disorder often experience weight loss on stimulants, which may limit optimal dosing and compliance. Cyproheptadine has been shown in medical samples to stimulate weight gain. We conducted a retrospective chart review of 28 consecutive pediatric psychiatry outpatients prescribed cyproheptadine for weight loss or insomnia while on stimulants. Of these, 4 patients never took cyproheptadine consistently, and 3 discontinued it within the first 7 days due to intolerable side effects. Data were analyzed for 21 other patients (age range 4-15 years) who continued with 4-8 mg of cyproheptadine nightly (mean final dose = 4.9 mg/day) for at least 14 days (mean duration = 104.7 days). Most had lost weight on stimulant alone (mean weight loss was 2.1 kg, mean weight velocity was -19.3 g/day). All 21 gained weight taking concomitant cyproheptadine, with a mean gain of 2.2 kg (paired t = 6.87, p < 0.0001) and a mean weight velocity of 32.3 g/day. Eleven of 17 patients who had reported initial insomnia on stimulant alone noted significant improvements in sleep with cyproheptadine added. We conclude that concomitant cyproheptadine may be useful in youths with attention deficit hyperactivity disorder for stimulant-induced weight loss, pending future randomized controlled trials. | A chart review of cyproheptadine for stimulant-induced weight loss. |
38784540 | Objective To determine whether risk factors in childhood and early adulthood affect later mammographic breast density. Methods: Subjects were 628 women who attended a medical examination at the University of Glasgow Student Health Service (1948–1968), responded to a questionnaire (2001) and had a screening mammogram in Scotland (1989–2002). Mammograms (median age of 59years) were classified using a six category classification (SCC) of breast density percent. Logistic regression was used to determine associations between risk factors and having a high-risk mammogram (≥25 dense). Results: In multi-variable analyses, high-risk mammograms were associated with parity (adjusted odds ratio (OR) per child: 0.77 (95 confidence interval (CI) 0.61–0.99)), age at first birth, OR per year: 1.05 (0.99–1.11), smoking at university, OR smokers versus non-smokers: 0.58 (0.36–0.92) and body mass index (BMI) while at university, OR per 1kg/m20.75 (0.69–0.82). No associations with SCC were found for age at menarche, birth weight, oral contraceptive (OC) use, height, leg length or exercise at age 20. Conclusions: We confirm previous findings that breast density is affected by reproductive events and some anthropometric measures, however most of the risk factors acting throughout the life course which we examined were not closely related to adult breast density. | Life course breast cancer risk factors and adult breast density (United Kingdom) |
38793927 | A major clinical manifestation of bone cancers is bone destruction. It is widely accepted that this destruction is not caused by the malignant cells themselves, but by osteoclasts, multinucleated cells of monocytic origin that are considered to be the only cells able to degrade bone. The present study demonstrates that bone-resorbing osteoclasts from myeloma patients contain nuclei with translocated chromosomes of myeloma B-cell clone origin, in addition to nuclei without these translocations, by using combined FISH and immunohistochemistry on bone sections. These nuclei of malignant origin are transcriptionally active and appear fully integrated amongst the other nuclei. The contribution of malignant nuclei to the osteoclast population analysed in this study was greater than 30%. Osteoclast-myeloma clone hybrids contained more nuclei than normal osteoclasts and their occurrence correlated with the proximity of myeloma cells. Similar hybrid cells were generated in myeloma cell-osteoclast co-cultures, as revealed by tracing myeloma nuclei using translocations, bromo-deoxyuridine, or the Y chromosome of male myeloma cells in female osteoclasts. These observations indicate that hybrid cells can originate through fusion between myeloma cells and osteoclasts. In conclusion, malignant cells contribute significantly to the formation of bone-resorbing osteoclasts in multiple myeloma. Osteoclast-myeloma clone hybrids reflect a previously unrecognized mechanism of bone destruction in which malignant cells participate directly. The possibility that malignant cells corrupt host cells by the transfer of malignant DNA may have been underestimated to date in cancer research. | Osteoclast nuclei of myeloma patients show chromosome translocations specific for the myeloma cell clone: a new type of cancer-host partnership? |
38794814 | The human ability to continuously track dynamic environmental stimuli, in particular speech, is proposed to profit from "entrainment" of endogenous neural oscillations, which involves phase reorganization such that "optimal" phase comes into line with temporally expected critical events, resulting in improved processing. The current experiment goes beyond previous work in this domain by addressing two thus far unanswered questions. First, how general is neural entrainment to environmental rhythms: Can neural oscillations be entrained by temporal dynamics of ongoing rhythmic stimuli without abrupt onsets? Second, does neural entrainment optimize performance of the perceptual system: Does human auditory perception benefit from neural phase reorganization? In a human electroencephalography study, listeners detected short gaps distributed uniformly with respect to the phase angle of a 3-Hz frequency-modulated stimulus. Listeners' ability to detect gaps in the frequency-modulated sound was not uniformly distributed in time, but clustered in certain preferred phases of the modulation. Moreover, the optimal stimulus phase was individually determined by the neural delta oscillation entrained by the stimulus. Finally, delta phase predicted behavior better than stimulus phase or the event-related potential after the gap. This study demonstrates behavioral benefits of phase realignment in response to frequency-modulated auditory stimuli, overall suggesting that frequency fluctuations in natural environmental input provide a pacing signal for endogenous neural oscillations, thereby influencing perceptual processing. | Frequency modulation entrains slow neural oscillations and optimizes human listening behavior. |
38799797 | Interventions by the pharmacists have always been considered as a valuable input by the health care community in the patient care process by reducing the medication errors, rationalizing the therapy and reducing the cost of therapy. The primary objective of this study was to determine the number and types of medication errors intervened by the dispensing pharmacists at OPD pharmacy in the Khoula Hospital during 2009 retrospectively. The interventions filed by the pharmacists and assistant pharmacists in OPD pharmacy were collected. Then they were categorized and analyzed after a detailed review. The results show that 72.3% of the interventions were minor of which 40.5% were about change medication order. Comparatively more numbers of prescriptions were intervened in female patients than male patients. 98.2% of the interventions were accepted by the prescribers reflecting the awareness of the doctors about the importance of the pharmacy practice. In this study only 688 interventions were due to prescribing errors of which 40.5% interventions were done in changing the medication order of clarifying the medicine. 14.9% of the interventions were related to administrative issues, 8.7% of the interventions were related to selection of medications as well as errors due to ignorance of history of patients. 8.2% of the interventions were to address the overdose of medications. Moderately significant interventions were observed in 19.4% and 7.5% of them were having the impact on major medication errors. Pharmacists have intervened 20.8% of the prescriptions to prevent complications, 25.1% were to rationalize the treatment, 7.9% of them were to improve compliance. Based on the results we conclude that the role of pharmacist in improving the health care system is vital. We recommend more number of such research based studies to bring awareness among health care professionals, provide solution to the prescription and dispensing problems, as it can also improve the documentation system, emphasize the importance of it, reduce prescribing errors, and update the knowledge of pharmacists and other health care professionals. | Interventions by pharmacists in out-patient pharmaceutical care. |
38805486 | Nickel is a fundamental micronutrient for cellular life, but it is toxic in soluble form at nonphysiological concentrations. Such potentially contradictory features required living organisms to develop efficient systems for nickel utilization and homeostasis. This is the case for incorporation of nickel into the active site of urease, a multistep, tightly regulated process, requiring the interplay of various accessory proteins. The understanding of this activation mechanism may find medical applications against ureolytic bacteria, among which Mycobacterium tuberculosis is a deadly pathogen for humans. The topic of this study is UreG, an essential chaperone in the in vivo activation of urease upon insertion of Ni2+ into the active site. The protein was examined using both experimental and computational approaches. In particular, the soluble M. tuberculosis UreG (MtUreG) was overexpressed in Escherichia coli and purified to homogeneity. The identity of the isolated protein was established by mass spectrometry. On-line size-exclusion chromatography and light scattering indicated that MtUreG exists as a dimeric form in solution. Determination of the free thiol concentration revealed that a disulfide bond is present in the dimer. The isolated MtUreG shows low GTPase activity under native conditions, with a kcat of 0.01 min-1. Circular dichroism spectroscopy demonstrated the presence of a well-defined secondary structure (8% alpha-helices, 29% beta-strands) in MtUreG, whereas NMR spectroscopy indicated that this protein does not behave as a rigid three-dimensional fold and thus can be assigned to the class of intrinsically unstructured polypeptides. The molecular model of MtUreG in the fully folded and functional form was built using fold recognition algorithms. An extensive similarity search was performed to determine conservation patterns in all known bacterial UreG sequences. The generation of a multiple-sequence alignment and the related phylogenetic tree allowed us to recognize key residues and motifs that are likely important for protein function. A structural database containing the homology-built models of the most representative UreG proteins was created, confirming the structural analogies among the UreG family. A flexible region, likely to be important for protein function, is identified. The structural conservation among this class of GTPases is discussed on the basis of their function in the urease assembly process. | Biochemical studies on Mycobacterium tuberculosis UreG and comparative modeling reveal structural and functional conservation among the bacterial UreG family. |
38808600 | Integrins, a large family of cell adhesion receptors, have been shown to play an important role for glioma proliferation and invasion. Several integrin receptors, including αvβ3, αvβ5, and α5β1, have generated clinical interest for glioma diagnosis and antitumor therapy. Integrin α5β1 has been highlighted as a prognostic and diagnostic marker in glioma, and its expression is correlated with a worse prognosis in high-grade glioma. However, unlike extensively studied integrins αvβ3 and αvβ5, very few integrin α5β1-specific radiotracers have been reported. Developing α5β1-specific radiotracers may provide alternative diagnosis and evaluation options in addition to well-studied αvβ3/αvβ5-specific tracers, and they may add new documents for profiling tumor progression. Here, a novel integrin α5β1-specific probe (99m)Tc-HisoDGR was fabricated for SPECT (single-photon emission computed tomography) imaging of glioma. To confirm its selective targeting of integrin α5β1 in vivo, the mouse models of α5β1-positive U87MG human glioma were subjected to SPECT/CT scans, and biodistribution experiments and blocking studies were performed. Small-animal SPECT/CT imaging experiments demonstrated that the tumors were clearly visualized in both subcutaneous and orthotopic glioma tumor models with clear background at 0.5, 1, and 2 h p.i. The tumor accumulation of (99m)Tc-HisoDGR showed significant reduction when excess cold isoDGR peptide was coinjected, suggesting that the tumor uptake was specifically mediated. Our work revealed that (99m)Tc-HisoDGR represented a powerful molecular probe for integrin α5β1-positive cancer imaging; moreover, it might be a promising tool for evaluating malignancy, predicting prognosis, selecting subpopulations of patients who might be sensitive to integrin α5β1-targeted drugs, and assessing and monitoring the response to integrin α5β1-targeted drugs in clinical trials. | (99m)Tc-HisoDGR as a Potential SPECT Probe for Orthotopic Glioma Detection via Targeting of Integrin α5β1. |
38811597 | Tyrosine hydroxylase (TH, EC 1.14.16.2) from beef brain striata was purified 23-fold from an extract of an acetone powder. If this enzyme preparation is treated with a cyclic AMP[-dependent protein phosphorylation system, there is a change in the pH dependence of the enzyme activity. The pH optimum at saturating tetrahydrobiopterin (BH4) concentration is shifted from below pH 6 to about pH 6.7. At pH 7, activation is expressed mainly as an increase in Vmax, whereas at pH 6, activation is expressed mainly as a decrease in Km for the pterin cofactor. Further, even with the control enzyme the Km for pterin cofactor declines precipitously as the pH is increased from 6 toward neutrality. Similar data were obtained with G-25 Sephadex-treated rat striatal TH. Experiments in which rat striatal synaptosomes were used demonstrated that the in situ activation of TH by phosphorylating conditions is expressed primarily as an increase in the maximum rate of dopamine synthesis. These results indicate that changes in TH activity caused by cyclic AMP-dependent protein phosphorylation will depend to a large extent on the pH of the TH environment. | Effect of cyclic AMP-dependent protein phosphorylating conditions on the pH-dependent activity of tyrosine hydroxylase from beef and rat striata. |
38830961 | Although TNF is a major proinflammatory cytokine, increasing evidence indicates that TNF also has immunosuppressive feedback effects. We have demonstrated in this study that, in both resting and activated states, mouse peripheral CD4(+)CD25(+) T regulatory cells (Tregs) expressed remarkably higher surface levels of TNFR2 than CD4(+)CD25(-) T effector cells (Teffs). In cocultures of Tregs and Teffs, inhibition of proliferation of Teffs by Tregs was initially transiently abrogated by exposure to TNF, but longer exposure to TNF restored suppressive effects. Cytokine production by Teffs remained continually suppressed by Tregs. The profound anergy of Tregs in response to TCR stimulation was overcome by TNF, which expanded the Treg population. Furthermore, in synergy with IL-2, TNF expanded Tregs even more markedly up-regulated expression of CD25 and FoxP3 and phosphorylation of STAT5, and enhanced the suppressive activity of Tregs. Unlike TNF, IL-1beta and IL-6 did not up-regulate FoxP3-expressing Tregs. Furthermore, the number of Tregs increased in wild-type mice, but not in TNFR2(-/-) mice following sublethal cecal ligation and puncture. Depletion of Tregs significantly decreased mortality following cecal ligation and puncture. Thus, the stimulatory effect of TNF on Tregs resembles the reported costimulatory effects of TNF on Teffs, but is even more pronounced because of the higher expression of TNFR2 by Tregs. Moreover, our study suggests that the slower response of Tregs than Teffs to TNF results in delayed immunosuppressive feedback effects. | Interaction of TNF with TNF receptor type 2 promotes expansion and function of mouse CD4+CD25+ T regulatory cells. |
38844612 | The origins of the mesenchymal cells participating in tissue repair and pathological processes, notably tissue fibrosis, tumor invasiveness, and metastasis, are poorly understood. However, emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) represent one important source of these cells. As we discuss here, processes similar to the EMTs associated with embryo implantation, embryogenesis, and organ development are appropriated and subverted by chronically inflamed tissues and neoplasias. The identification of the signaling pathways that lead to activation of EMT programs during these disease processes is providing new insights into the plasticity of cellular phenotypes and possible therapeutic interventions. | The basics of epithelial-mesenchymal transition. |
38873881 | Consecutive child psychiatric outpatient admissions with disruptive behavior or adjustment disorders were assessed by validated instruments for trauma exposure and posttraumatic stress disorder (PTSD) symptoms and other psychopathology. Four reliably diagnosed groups were defined in a retrospective case-control design: Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), comorbid ADHD-ODD, and adjustment disorder controls. ODD and (although to a lesser extent) ADHD were associated with a history of physical or sexual maltreatment. PTSD symptoms were most severe if (a) ADHD and maltreatment co-occurred or (b) ODD and accident/illness trauma co-occurred. The association between ODD and PTSD Criterion D (hyperarousal/hypervigilance) symptoms remained after controlling for overlapping symptoms, but the association of ADHD with PTSD symptoms was largely due to an overlapping symptom. These findings suggest that screening for maltreatment, other trauma, and PTSD symptoms may enhance prevention, treatment, and research concerning childhood disruptive behavior disorders. | Child maltreatment, other trauma exposure, and posttraumatic symptomatology among children with oppositional defiant and attention deficit hyperactivity disorders. |
38882175 | PURPOSE The purpose of this study was to compare a laboratory based exercise challenge (LBC) to a field based exercise challenge (FBC) for pulmonary function test (PFT) exercise-induced asthma (EIA) screening of elite athletes.
METHODS Twenty-three elite cold weather athletes (14 men, 9 women) PFT positive for EIA (FBC screened) served as subjects. Twenty-three gender and sport matched controls (nonasthmatics) were randomly selected to establish PFT reference values for normal elite athletes. Before FBC, athletes completed a medical history questionnaire for EIA symptoms. FBC evaluations consisted of baseline spirometry, actual or simulated competition, and 5, 10, and 15 min postexercise spirometry. PFT positive athletes were evaluated in the laboratory using an exercise challenge simulating race intensity (ambient conditions: 21 degrees C, 60% relative humidity). PFT procedures were identical to FBC.
RESULTS 91% of PFT positive and 48% of PFT normal athletes reported at least one symptom of EIA, with postrace cough most frequent. Baseline spirometry was the same for PFT positives and normal controls. Lower limit reference range (MN - 2 SD) of FEV1 for controls suggests that postexercise decrements of greater than approximately -7% indicate abnormal airway response in this population. Exercise time duration did not effect bronchial reactivity; 78% of FBC PFT positives were PFT normal post-LBC.
CONCLUSION Self-reported symptoms by elite athletes are not reliable in identifying EIA. Reference range criterion for FEV1 decrement in the elite athlete postexercise contrasts current recommended guidelines. Moreover, a large number of false negatives may occur in this population if EIA screening is performed with inadequate exercise and environmental stress. | Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge. |
38886345 | BACKGROUND JX-594 is a targeted oncolytic poxvirus designed to selectively replicate in and destroy cancer cells with cell-cycle abnormalities and epidermal growth factor receptor (EGFR)-ras pathway activation. Direct oncolysis plus granulocyte-macrophage colony-stimulating factor (GM-CSF) expression also stimulates shutdown of tumour vasculature and antitumoral immunity. We aimed to assess intratumoral injection of JX-594 in patients with refractory primary or metastatic liver cancer.
METHODS Between Jan 4, 2006, and July 4, 2007, 14 patients with histologically confirmed refractory primary or metastatic liver tumours (up to 10.9 cm total diameter) that were amenable to image-guided intratumoral injections were enrolled into this non-comparative, open-label, phase I dose-escalation trial (standard 3x3 design; two to six patients for each dose with 12-18 estimated total patients). Patients received one of four doses of intratumoral JX-594 (10(8) plaque-forming units [pfu], 3x10(8) pfu, 10(9) pfu, or 3x10(9) pfu) every 3 weeks at Dong-A University Hospital (Busan, South Korea). Patients were monitored after treatment for at least 48 h in hospital and for at least 4 weeks as out-patients. Adverse event-monitoring according to the National Cancer Institute Common Toxicity Criteria (version 3) and standard laboratory toxicity grading for haematology, liver and renal function, coagulation studies, serum chemistry, and urinalysis were done. The primary aims were to ascertain the maximum-tolerated dose (MTD) and safety of JX-594 treatment. Data were also collected on pharmacokinetics, pharmacodynamics, and efficacy. Analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00629759.
FINDINGS Of 22 patients with liver tumours who were assessed for eligibility, eight patients did not meet inclusion criteria. Therefore, 14 patients, including those with hepatocellular, colorectal, melanoma, and lung cancer, were enrolled. Patients were heavily pretreated (5.6 previous treatments, SD 2.8, range 2.0-12.0) and had large tumours (7.0 cm diameter, SD 2.7, range 1.8-10.9). Patients received a mean of 3.4 (SD 2.2, range 1.0-8.0) cycles of JX-594. All patients were evaluable for toxicity. All patients experienced grade I-III flu-like symptoms, and four had transient grade I-III dose-related thrombocytopenia. Grade III hyperbilirubinaemia was dose-limiting in both patients at the highest dose; the MTD was therefore 1x10(9) pfu. JX-594 replication-dependent dissemination in blood was shown, with resultant infection of non-injected tumour sites. GM-CSF expression resulted in grade I-III increases in neutrophil counts in four of six patients at the MTD. Tumour responses were shown in injected and non-injected tumours. Ten patients were radiographically evaluable for objective responses; non-evaluable patients had contraindications to contrast medium (n=2) or no post-treatment scans (n=2). According to Response Evaluation Criteria in Solid Tumors (RECIST), three patients had partial response, six had stable disease, and one had progressive disease.
INTERPRETATION Intratumoral injection of JX-594 into primary or metastatic liver tumours was generally well-tolerated. Direct hyperbilirubinaemia was the dose-limiting toxicity. Safety was acceptable in the context of JX-594 replication, GM-CSF expression, systemic dissemination, and JX-594 had anti-tumoral effects against several refractory carcinomas. Phase II trials are now underway. | Use of a targeted oncolytic poxvirus, JX-594, in patients with refractory primary or metastatic liver cancer: a phase I trial. |
38899659 | Cells of the osteoblast lineage provide critical support for B lymphopoiesis in the bone marrow (BM). Parathyroid hormone (PTH) signaling in osteoblastic cells through its receptor (PPR) is an important regulator of hematopoietic stem cells; however, its role in regulation of B lymphopoiesis is not clear. Here we demonstrate that deletion of PPR in osteoprogenitors results in a significant loss of trabecular and cortical bone. PPR signaling in osteoprogenitors, but not in mature osteoblasts or osteocytes, is critical for B-cell precursor differentiation via IL-7 production. Interestingly, despite a severe reduction in B-cell progenitors in BM, mature B-lymphocytes were increased 3.5-fold in the BM of mice lacking PPR in osteoprogenitors. This retention of mature IgD(+) B cells in the BM was associated with increased expression of vascular cell adhesion molecule 1 (VCAM1) by PPR-deficient osteoprogenitors, and treatment with VCAM1 neutralizing antibody increased mobilization of B lymphocytes from mutant BM. Our results demonstrate that PPR signaling in early osteoblasts is necessary for B-cell differentiation via IL-7 secretion and for B-lymphocyte mobilization via VCAM1. | PTH Signaling in Osteoprogenitors Is Essential for B-Lymphocyte Differentiation and Mobilization. |
38919140 | The Snail transcription factor plays a key role in regulating diverse developmental processes but is not thought to play a role in mammalian neural precursors. Here, we have examined radial glial precursor cells of the embryonic murine cortex and demonstrate that Snail regulates their survival, self-renewal, and differentiation into intermediate progenitors and neurons via two distinct and separable target pathways. First, Snail promotes cell survival by antagonizing a p53-dependent death pathway because coincident p53 knockdown rescues survival deficits caused by Snail knockdown. Second, we show that the cell cycle phosphatase Cdc25b is regulated by Snail in radial precursors and that Cdc25b coexpression is sufficient to rescue the decreased radial precursor proliferation and differentiation observed upon Snail knockdown. Thus, Snail acts via p53 and Cdc25b to coordinately regulate multiple aspects of mammalian embryonic neural precursor biology. | Snail coordinately regulates downstream pathways to control multiple aspects of mammalian neural precursor development. |
38944245 | Lung Krüppel-like factor (LKLF/KLF2) is an endothelial transcription factor that is crucially involved in murine vasculogenesis and is specifically regulated by flow in vitro. We now show a relation to local flow variations in the adult human vasculature: decreased LKLF expression was noted at the aorta bifurcations to the iliac and carotid arteries, coinciding with neointima formation. The direct involvement of shear stress in the in vivo expression of LKLF was determined independently by in situ hybridization and laser microbeam microdissection/reverse transcriptase-polymerase chain reaction in a murine carotid artery collar model, in which a 4- to 30-fold induction of LKLF occurred at the high-shear sites. Dissection of the biomechanics of LKLF regulation in vitro demonstrated that steady flow and pulsatile flow induced basal LKLF expression 15- and 36-fold at shear stresses greater than approximately 5 dyne/cm2, whereas cyclic stretch had no effect. Prolonged LKLF induction in the absence of flow changed the expression of angiotensin-converting enzyme, endothelin-1, adrenomedullin, and endothelial nitric oxide synthase to levels similar to those observed under prolonged flow. LKLF repression by siRNA suppressed the flow response of endothelin-1, adrenomedullin, and endothelial nitric oxide synthase (P < 0.05). Thus, we demonstrate that endothelial LKLF is regulated by flow in vivo and is a transcriptional regulator of several endothelial genes that control vascular tone in response to flow. | Endothelial KLF2 links local arterial shear stress levels to the expression of vascular tone-regulating genes. |
39048693 | The cre/LoxP system can produce conditional loss of gene function in specific cell types such as neurons. A transgenic mouse line, utilized by multiple studies, used the Synapsin I promoter to drive expression of cre (SynCre) to achieve neuronal-specific cre expression. Herein we describe that cre expression can also be observed in SynCre mice within the testes after being bred into a floxed transgenic mouse line. Cre transcript was expressed in testes resulting in recombination of the floxed substrate in testes. In the majority of cases, progeny of male SynCre mice inherited a germline recombined floxed allele, while this was never observed in progeny from female mice carrying the SynCre allele. This observation should alert investigators to a potential confound using these mice and enables male germ cell "deletor" strategies. | Synapsin I Cre transgene expression in male mice produces germline recombination in progeny. |
39059143 | CONTEXT The association of an adult tele-intensive care unit (ICU) intervention with hospital mortality, length of stay, best practice adherence, and preventable complications for an academic medical center has not been reported.
OBJECTIVE To quantify the association of a tele-ICU intervention with hospital mortality, length of stay, and complications that are preventable by adherence to best practices.
DESIGN, SETTING, AND PATIENTS Prospective stepped-wedge clinical practice study of 6290 adults admitted to any of 7 ICUs (3 medical, 3 surgical, and 1 mixed cardiovascular) on 2 campuses of an 834-bed academic medical center that was performed from April 26, 2005, through September 30, 2007. Electronically supported and monitored processes for best practice adherence, care plan creation, and clinician response times to alarms were evaluated.
MAIN OUTCOME MEASURES Case-mix and severity-adjusted hospital mortality. Other outcomes included hospital and ICU length of stay, best practice adherence, and complication rates.
RESULTS The hospital mortality rate was 13.6% (95% confidence interval [CI], 11.9%-15.4%) during the preintervention period compared with 11.8% (95% CI, 10.9%-12.8%) during the tele-ICU intervention period (adjusted odds ratio [OR], 0.40 [95% CI, 0.31-0.52]). The tele-ICU intervention period compared with the preintervention period was associated with higher rates of best clinical practice adherence for the prevention of deep vein thrombosis (99% vs 85%, respectively; OR, 15.4 [95% CI, 11.3-21.1]) and prevention of stress ulcers (96% vs 83%, respectively; OR, 4.57 [95% CI, 3.91-5.77], best practice adherence for cardiovascular protection (99% vs 80%, respectively; OR, 30.7 [95% CI, 19.3-49.2]), prevention of ventilator-associated pneumonia (52% vs 33%, respectively; OR, 2.20 [95% CI, 1.79-2.70]), lower rates of preventable complications (1.6% vs 13%, respectively, for ventilator-associated pneumonia [OR, 0.15; 95% CI, 0.09-0.23] and 0.6% vs 1.0%, respectively, for catheter-related bloodstream infection [OR, 0.50; 95% CI, 0.27-0.93]), and shorter hospital length of stay (9.8 vs 13.3 days, respectively; hazard ratio for discharge, 1.44 [95% CI, 1.33-1.56]). The results for medical, surgical, and cardiovascular ICUs were similar.
CONCLUSION In a single academic medical center study, implementation of a tele-ICU intervention was associated with reduced adjusted odds of mortality and reduced hospital length of stay, as well as with changes in best practice adherence and lower rates of preventable complications. | Hospital mortality, length of stay, and preventable complications among critically ill patients before and after tele-ICU reengineering of critical care processes. |
39084565 | Experimental autoimmune myocarditis (EAM) represents a Th17 T cell-mediated mouse model of postinflammatory heart disease. In BALB/c wild-type mice, EAM is a self-limiting disease, peaking 21 days after alpha-myosin H chain peptide (MyHC-alpha)/CFA immunization and largely resolving thereafter. In IFN-gammaR(-/-) mice, however, EAM is exacerbated and shows a chronic progressive disease course. We found that this progressive disease course paralleled persistently elevated IL-17 release from T cells infiltrating the hearts of IFN-gammaR(-/-) mice 30 days after immunization. In fact, IL-17 promoted the recruitment of CD11b(+) monocytes, the major heart-infiltrating cells in EAM. In turn, CD11b(+) monocytes suppressed MyHC-alpha-specific Th17 T cell responses IFN-gamma-dependently in vitro. In vivo, injection of IFN-gammaR(+/+)CD11b(+), but not IFN-gammaR(-/-)CD11b(+), monocytes, suppressed MyHC-alpha-specific T cells, and abrogated the progressive disease course in IFN-gammaR(-/-) mice. Finally, coinjection of MyHC-alpha-specific, but not OVA-transgenic, IFN-gamma-releasing CD4(+) Th1 T cell lines, together with MyHC-alpha-specific Th17 T cells protected RAG2(-/-) mice from EAM. In conclusion, CD11b(+) monocytes play a dual role in EAM: as a major cellular substrate of IL-17-induced inflammation and as mediators of an IFN-gamma-dependent negative feedback loop confining disease progression. | CD11b+ monocytes abrogate Th17 CD4+ T cell-mediated experimental autoimmune myocarditis. |
39128592 | The thymic medulla provides a microenvironment where medullary thymic epithelial cells (mTECs) express autoimmune regulator and diverse tissue-restricted genes, contributing to launching self-tolerance. Positive selection is essential for thymic medulla formation via a previously unknown mechanism. Here we show that the cytokine RANK ligand (RANKL) was produced by positively selected thymocytes and regulated the cellularity of mTEC by interacting with RANK and osteoprotegerin. Forced expression of RANKL restored thymic medulla in mice lacking positive selection, whereas RANKL perturbation impaired medulla formation. These results indicate that RANKL produced by positively selected thymocytes is responsible for fostering thymic medulla formation, thereby establishing central tolerance. | The cytokine RANKL produced by positively selected thymocytes fosters medullary thymic epithelial cells that express autoimmune regulator. |
39164524 | Accumulation of adipocytes and collagen type-I-producing cells (fibrosis) is observed in muscular dystrophies. The origin of these cells had been largely unknown, but recently we identified mesenchymal progenitors positive for platelet-derived growth factor receptor alpha (PDGFRα) as the origin of adipocytes in skeletal muscle. However, the origin of muscle fibrosis remains largely unknown. In this study, clonal analyses show that PDGFRα(+) cells also differentiate into collagen type-I-producing cells. In fact, PDGFRα(+) cells accumulated in fibrotic areas of the diaphragm in the mdx mouse, a model of Duchenne muscular dystrophy. Furthermore, mRNA of fibrosis markers was expressed exclusively in the PDGFRα(+) cell fraction in the mdx diaphragm. Importantly, TGF-β isoforms, known as potent profibrotic cytokines, induced expression of markers of fibrosis in PDGFRα(+) cells but not in myogenic cells. Transplantation studies revealed that fibrogenic PDGFRα(+) cells mainly derived from pre-existing PDGFRα(+) cells and that the contribution of PDGFRα(-) cells and circulating cells was limited. These results indicate that mesenchymal progenitors are the main origin of not only fat accumulation but also fibrosis in skeletal muscle. | Fibrosis and adipogenesis originate from a common mesenchymal progenitor in skeletal muscle. |
39174007 | Free radicals vary widely in their thermodynamic properties, ranging from very oxidizing to very reducing. These thermodynamic properties can be used to predict a pecking order, or hierarchy, for free radical reactions. Using one-electron reduction potentials, the predicted pecking order is in agreement with experimentally observed free radical electron (hydrogen atom) transfer reactions. These potentials are also in agreement with experimental data that suggest that vitamin E, the primary lipid soluble small molecule antioxidant, and vitamin C, the terminal water soluble small molecule antioxidant, cooperate to protect lipids and lipid structures against peroxidation. Although vitamin E is located in membranes and vitamin C is located in aqueous phases, vitamin C is able to recycle vitamin E; i.e., vitamin C repairs the tocopheroxyl (chromanoxyl) radical of vitamin E, thereby permitting vitamin E to function again as a free radical chain-breaking antioxidant. This review discusses: (i) the thermodynamics of free radical reactions that are of interest to the health sciences; (ii) the fundamental thermodynamic and kinetic properties that are associated with chain-breaking antioxidants; (iii) the unique interfacial nature of the apparent reaction of the tocopherol free radical (vitamin E radical) and vitamin C; and (iv) presents a hierarchy, or pecking order, for free radical electron (hydrogen atom) transfer reactions. | The pecking order of free radicals and antioxidants: lipid peroxidation, alpha-tocopherol, and ascorbate. |
39187170 | Adipose tissue exerts important endocrine and metabolic functions in health and disease. Yet the bioenergetics of this tissue is not characterized in humans and possible regional differences are not elucidated. Using high resolution respirometry, mitochondrial respiration was quantified in human abdominal subcutaneous and intra-abdominal visceral (omentum majus) adipose tissue from biopsies obtained in 20 obese patients undergoing bariatric surgery. Mitochondrial DNA (mtDNA) and genomic DNA (gDNA) were determined by the PCR technique for estimation of mitochondrial density. Adipose tissue samples were permeabilized and respirometric measurements were performed in duplicate at 37 degrees C. Substrates (glutamate (G) + malate (M) + octanoyl carnitine (O) + succinate (S)) were added sequentially to provide electrons to complex I + II. ADP ((D)) for state 3 respiration was added after GM. Uncoupled respiration was measured after addition of FCCP. Visceral fat contained more mitochondria per milligram of tissue than subcutaneous fat, but the cells were smaller. Robust, stable oxygen fluxes were found in both tissues, and coupled state 3 (GMOS(D)) and uncoupled respiration were significantly (P < 0.05) higher in visceral (0.95 +/- 0.05 and 1.15 +/- 0.06 pmol O(2) s(1) mg(1), respectively) compared with subcutaneous (0.76 +/- 0.04 and 0.98 +/- 0.05 pmol O(2) s(1) mg(1), respectively) adipose tissue. Expressed per mtDNA, visceral adipose tissue had significantly (P < 0.05) lower mitochondrial respiration. Substrate control ratios were higher and uncoupling control ratio lower (P < 0.05) in visceral compared with subcutaneous adipose tissue. We conclude that visceral fat is bioenergetically more active and more sensitive to mitochondrial substrate supply than subcutaneous fat. Oxidative phosphorylation has a higher relative activity in visceral compared with subcutaneous adipose tissue. | Mitochondrial respiration in subcutaneous and visceral adipose tissue from patients with morbid obesity. |
39225849 | The Bloom syndrome helicase (BLM) is critical for genomic stability. A defect in BLM activity results in the cancer-predisposing Bloom syndrome (BS). Here, we report that BLM-deficient cell lines and primary fibroblasts display an endogenously activated DNA double-strand break checkpoint response with prominent levels of phosphorylated histone H2AX (gamma-H2AX), Chk2 (p(T68)Chk2), and ATM (p(S1981)ATM) colocalizing in nuclear foci. Interestingly, the mitotic fraction of gamma-H2AX foci did not seem to be higher in BLM-deficient cells, indicating that these lesions form transiently during interphase. Pulse labeling with iododeoxyuridine and immunofluorescence microscopy showed the colocalization of gamma-H2AX, ATM, and Chk2 together with replication foci. Those foci costained for Rad51, indicating homologous recombination at these replication sites. We therefore analyzed replication in BS cells using a single molecule approach on combed DNA fibers. In addition to a higher frequency of replication fork barriers, BS cells displayed a reduced average fork velocity and global reduction of interorigin distances indicative of an elevated frequency of origin firing. Because BS is one of the most penetrant cancer-predisposing hereditary diseases, it is likely that the lack of BLM engages the cells in a situation similar to precancerous tissues with replication stress. To our knowledge, this is the first report of high ATM-Chk2 kinase activation and its linkage to replication defects in a BS model. | Endogenous gamma-H2AX-ATM-Chk2 checkpoint activation in Bloom's syndrome helicase deficient cells is related to DNA replication arrested forks. |
39264456 | OBJECTIVES We investigated the role of cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in cachexia development in newly diagnosed nonsmall cell lung cancer (NSCLC) patients.
METHODS : We evaluated 44 (M/F:41/3) NSCLC patients and 12 (M/F:10/2) age matched healthy smokers. NSCLC cases with a weight loss of > or =10% consisted the cachectic group (n:23, M/F:21/2) and the ones with <10% weight loss consisted the noncachectic group (n:21, M/F:19/2).
RESULTS Body mass index (BMI) of cachectics was significantly lower than that of noncachectics (21.0 +/- 2.9 versus 24.5 +/- 3.6, P = 0.02) and controls (21.0 +/- 2.9 versus 25.5 +/- 2.6, P = 0.01). Serum TNF-alpha level did not differ between cachectic and noncachectics (37.3 +/- 39.1 and 51.6 +/- 84.2 pg/mL, respectively). However, it was significantly higher in NSCLC patients compared with controls (44.1 +/- 64.3 and 15.1 +/- 14.3 pg/mL, P = 0.03). Serum IL-6 level was not different between 3 groups (6.4 +/- 4.1, 8.9 +/- 16.3, and 4.1 +/- 3.5 pg/mL, respectively) but it correlated significantly with TNF-alpha (r = 0.4, P = 0.006) and BMI (r = -0.3, P = 0.03). Erythrocyte sedimentation rate (ESR) correlated significantly with TNF-alpha (r = 0.4, P = 0.003) and BMI (r = -0.3, P = 0.03). Among 44 cases, survival of 12 and 17 patients was recorded in cachectics and noncachectics, with no statistical difference (12.2 +/- 3.7 and 11.2 +/- 1.0 months, respectively).
CONCLUSIONS TNF-alpha and IL-6 levels did not differ significantly between cachectics and noncachectics. However, significant correlations between IL-6, BMI, and TNF-alpha suggested that these cytokines acted as cofactors in weight loss. Survival was neither influenced by BMI, nor the cytokine levels in the present study. The significant correlation of ESR with TNF-alpha suggested that ESR could provide valuable clue for considerable weight loss in the follow-up of NSCLC patients. | Impact of TNF-alpha and IL-6 levels on development of cachexia in newly diagnosed NSCLC patients. |
39281140 | CONTEXT Sexual dysfunction is a common adverse effect of antidepressants that frequently results in treatment noncompliance.
OBJECTIVE To assess the efficacy of sildenafil citrate in men with sexual dysfunction associated with the use of selective and nonselective serotonin reuptake inhibitor (SRI) antidepressants.
DESIGN, SETTING, AND PATIENTS Prospective, parallel-group, randomized, double-blind, placebo-controlled trial conducted between November 1, 2000, and January 1, 2001, at 3 US university medical centers among 90 male outpatients (mean [SD] age, 45 [8] years) with major depression in remission and sexual dysfunction associated with SRI antidepressant treatment.
INTERVENTION Patients were randomly assigned to take sildenafil (n = 45) or placebo (n = 45) at a flexible dose starting at 50 mg and adjustable to 100 mg before sexual activity for 6 weeks.
MAIN OUTCOME MEASURES The primary outcome measure was score on the Clinical Global Impression-Sexual Function (CGI-SF); secondary measures were scores on the International Index of Erectile Function, Arizona Sexual Experience Scale, Massachusetts General Hospital-Sexual Functioning Questionnaire, and Hamilton Rating Scale for Depression (HAM-D).
RESULTS Among the 90 randomized patients, 93% (83/89) of patients treated per protocol took at least 1 dose of study drug and 85% (76/89) completed week 6 end-point assessments with last observation carried forward analyses. At a CGI-SF score of 2 or lower, 54.5% (24/44) of sildenafil compared with 4.4% (2/45) of placebo patients were much or very much improved (P<.001). Erectile function, arousal, ejaculation, orgasm, and overall satisfaction domain measures improved significantly in sildenafil compared with placebo patients. Mean depression scores remained consistent with remission (HAM-D score < or =10) in both groups for the study duration.
CONCLUSION In our study, sildenafil effectively improved erectile function and other aspects of sexual function in men with sexual dysfunction associated with the use of SRI antidepressants. These improvements may allow patients to maintain adherence with effective antidepressant treatment. | Treatment of antidepressant-associated sexual dysfunction with sildenafil: a randomized controlled trial. |
39281166 | Mammalian genomes are extensively transcribed outside the borders of protein-coding genes. Genome-wide studies recently demonstrated that cis-regulatory genomic elements implicated in transcriptional control, such as enhancers and locus-control regions, represent major sites of extragenic noncoding transcription. Enhancer-templated transcripts provide a quantitatively small contribution to the total amount of cellular nonribosomal RNA; nevertheless, the possibility that enhancer transcription and the resulting enhancer RNAs may, in some cases, have functional roles, rather than represent mere transcriptional noise at accessible genomic regions, is supported by an increasing amount of experimental data. In this article we review the current knowledge on enhancer transcription and its functional implications. | Noncoding transcription at enhancers: general principles and functional models. |
39285547 | Streptococcus pneumoniae is a leading cause of invasive bacterial disease. This is the first study to examine the expression of S. pneumoniae genes in vivo by using whole-genome microarrays available from The Institute for Genomic Research. Total RNA was collected from pneumococci isolated from infected blood, infected cerebrospinal fluid, and bacteria attached to a pharyngeal epithelial cell line in vitro. Microarray analysis of pneumococcal genes expressed in these models identified body site-specific patterns of expression for virulence factors, transporters, transcription factors, translation-associated proteins, metabolism, and genes with unknown function. Contributions to virulence predicted for several unknown genes with enhanced expression in vivo were confirmed by insertion duplication mutagenesis and challenge of mice with the mutants. Finally, we cross-referenced our results with previous studies that used signature-tagged mutagenesis and differential fluorescence induction to identify genes that are potentially required by a broad range of pneumococcal strains for invasive disease. | Microarray analysis of pneumococcal gene expression during invasive disease. |
39291138 | Cells develop by reading mixed signals. Nowhere is this clearer than in the highly dynamic processes that propel embryogenesis, when critical cell-fate decisions are made swiftly in response to well-orchestrated growthfactor combinations. Learning how diverse signaling pathways are integrated is therefore essential for understanding physiology. This requires the identification, in tangible molecular terms, of key nodes for pathway integration that operate in vivo. A report in this issue, on the integration of Smad and Ras/MAPK pathways during neural induction (Pera et al. 2003), provides timely insights into the relevance of one such node. Pera et al. (2003) report that FGF8 and IGF2—two growth factors that activate the Ras/MAPK pathway— favor neural differentiation and mesoderm dorsalization in Xenopus by inhibiting BMP (Bone Morphogenetic Protein) signaling. Mesoderm is formed from ectoderm in response to Nodal-related signals from the endoderm at the blastula stage and beyond (Fig. 1; for review, see De Robertis et al. 2000). BMP induces differentiation of ectoderm into epidermal cell fates at the expense of neural fates, and it ventralizes the mesoderm at the expense of dorsal fates (for review, see Weinstein and HemmatiBrivanlou 1999; De Robertis et al. 2000). Accordingly, neural differentiation and dorsal mesoderm formation are favored when BMP signaling is attenuated. Noggin, Chordin, Cerberus, and Follistatin, secreted by the Spemann organizer on the dorsal side at the gastrula stage, facilitate the formation of neural tissue by sequestering BMP (Weinstein and Hemmati-Brivanlou 1999; De Robertis et al. 2000). Experimentally blocking BMP signaling with a dominant-negative BMP receptor has a similar effect of promoting ectoderm neuralization (Weinstein and Hemmati-Brivanlou 1999). As it turns out, neural induction can also be achieved with FGF (fibroblast growth factor; Kengaku and Okamoto 1993; Lamb and Harland 1995; Hongo et al. 1999; Hardcastle et al. 2000; Streit et al. 2000; Wilson et al. 2000) and IGF (insulin-like growth factor; Pera et al. 2001; Richard-Parpaillon et al. 2002). Injection of transcripts encoding FGF8 or IFG2 into one animal-pole blastomere of a fourto eight-cell embryo results in an expanded neural plate at the injected side (Pera et al. 2003). Surprisingly, expression of a dominant-negative FGF receptor prevents neuralization of ectoderm explants by the BMP blocker Noggin (Launay et al. 1996). Likewise, the potent neuralizing effect of Chordin can be blocked by a dominant-negative FGF receptor or a morpholino oligonucleotide targeting the IGF receptor (Pera et al. 2003). Thus, the neuralizing effect of BMP inhibitors is somehow tied to FGF and IFG signaling. The question is, how? Because FGF8 and IFG2 activate MAPK, Pera et al. (2003) took heed from previous work showing that MAPK inhibits the BMP signal-transduction factor Smad1 (Kretzschmar et al. 1997a). Smad1 is directly phosphorylated by the BMP receptor, resulting in Smad1 activation (Kretzschmar et al. 1997b), and by MAPK in response to EGF, resulting in Smad1 inhibition (Kretzschmar et al. 1997a; Fig. 2). Smad transcription factors mediate gene responses to the entire TGF (Transforming Growth Factor) family, to which the BMPs belong (for review, see Massague 2000; Derynck and Zhang 2003). Smads 1, 5, and 8 act primarily downstream of BMP receptors and Smads 2 and 3 downstream of TGF , Activin and Nodal receptors. Smad proteins have two conserved globular domains—the MH1 and MH2 domains (Fig. 2). The MH1 domain is involved in DNA binding and the MH2 domain in binding to cytoplasmic retention factors, activated receptors, nucleoporins in the nuclear pore, and DNA-binding cofactors, coactivators, and corepressors in the nucleus (for review, see Shi and Massague 2003). Receptor-mediated phosphorylation occurs at the carboxy-terminal sequence SXS. This enables the nuclear accumulation of Smads and their association with the shared partner Smad4 to form transcriptional complexes that are interpreted by the cell as a function of the context (Massague 2000). Between the MH1 and MH2 domains lies a linker region of variable sequence and length. Attention was drawn to this region when it was found that EGF (epidermal growth factor), a classical activator of the Ras/ MAPK pathway, causes phosphorylation of the Smad1 linker at four MAPK sites (PXSP sequences; Kretzschmar et al. 1997a). This prevents the nuclear localization of Smad1 and inhibits BMP signaling. Mutation of these E-MAIL j-massague@ski.mskcc.org; FAX (212) 717-3298. Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/ gad.1167003. | Integration of Smad and MAPK pathways: a link and a linker revisited. |
39300105 | Selected clinical pharmacy interventions undertaken during a 30-day data capture period were analysed, seeking to gain a greater understanding of the nature of the drug-related problems involved. Pharmacists were asked to record only interventions that were of potentially major significance. A total of 67 interventions were submitted for analysis. In 28 cases (41.7% of the initial total) the intervention reports were excluded from further analysis after initial review. For the remaining 39 interventions, 20 patients (51%) were under the care of a medical unit, and cardiovascular/antithrombotic agents accounted for 17 reports (43.5%). The majority of interventions were implemented at the time of inpatient medication order review by the clinical pharmacist (n=25, 64%). The most common category of drug-related problem addressed in the interventions related to the prescription of inappropriately high doses of the correct drug for the patient (n=17, 43.6%). Deficiencies in technical knowledge accounted for less than 25% of all cases. | A brief analysis of clinical pharmacy interventions undertaken in an Australian teaching hospital. |
39304380 | Simultaneous parenteral vaccination against typhoid and cholera lead to death through either anaphylactic shock or endotoxic shock in a 36-year-old male. At autopsy the charactertic features of shock as well as chronic interstitial myocarditis were noted. Moreover, fresh histiocytic and lymphocytic nodules were found in the liver, heart and meninges. A review of the literature dealing with lethal complications following parenteral tyhoid vaccinations shows an increased risk in debilitated persons (emaciation, stress, cold). Most of the fatalities occurred in persons who had previous disturbances of the cardiovascular system, as in the case reviewed here. Cardiac failure, Landry's paralysis, renal failure and disturbances of skin, joints and intestines may also follow typhoid vaccinations. However, these latter complications are usually not lethal. The patients presented here had many of the conditions which are known to aggravate the situation and to lead to a lethal culmination. The review of this case and the disucussion following it shows that only healthy persons should receive the parenteral typhoid vaccination. Hopefully, the presentation of this material will help prevent fatalities of this type in the future. | Lethal complications of typhoid-cholera-vaccination. (Case report and review of the literature). |
39326723 | Substantial progress in functional genomic and proteomic technologies has opened new perspectives in biomedical research. The sequence of the human genome has been mostly determined and opened new visions on its complexity and regulation. New technologies, like RNAi and protein arrays, allow gathering knowledge beyond single gene analysis. Increasingly, biological processes are studied with systems biological approaches, where qualitative and quantitative data of the components are utilized to model the respective processes, to predict effects of perturbations, and to then refine these models after experimental testing. Here, we describe the potential of applying functional genomics and proteomics, taking the ERBB family of growth-factor receptors as an example to study the signaling network and its impact on cancer. | Functional genomics and proteomics approaches to study the ERBB network in cancer. |
39334724 | Spatial filters have been used as an easy and intuitive way to create smoothed disease maps. Birth weight data from New York State for 1994 and 1995 are used to compare the traditional filter type of fixed geographical size with a filter size of constant or nearly constant population size. The latter are more appropriate for mapping disease in geographic areas with widely varying population density, such as New York State. Issues such as the choice of population size for the filter, the scale of smoothing, the ability to detect true spatial variation and the ability to smooth over random spatial noise are evaluated and discussed. | Evaluation of spatial filters to create smoothed maps of health data. |
39368721 | OBJECTIVE to investigate the role of glucose tolerance in the development of hypertension.
DESIGN Retrospective analysis of the results of a health check up in a group of clinically healthy middle aged men in the late 1960s (median year 1968). The subjects were invited to enter into a primary prevention trial for cardiovascular disease in 1974, when they underwent clinical examination for risk factors. The trial was completed in 1979, when the men were re-examined. Follow up was in 1986.
SETTING Institute of Occupational Health, Helsinki, Finland and second department of medicine, University of Helsinki. SUBJECTS In all, 3490 men born during 1919-34 participated in a health check up in the late 1960s. In 1974, 1815 of these men who were clinically healthy were entered into a primary prevention trial for cardiovascular disease. On clinical examination 1222 of the men were considered at high risk of cardiovascular disease. Of these, 612 received an intervention and were excluded from the study. A total of 593 men were without risk factors. The study comprised all of the men who did not have an intervention (n = 1203). In 1979, 1120 men were re-examined, and in 1986 945 men attended follow up. There were two groups for analysis: one comprising all subjects and the other comprising only men who were normotensive in 1968 and for whom complete information was available.
INTERVENTIONS By 1979, 103 men were taking antihypertensive drugs, and by 1986, 131 were taking antihypertensive drugs and 12 were taking drugs for hyperglycaemia.
MAIN OUTCOME MEASURES Blood glucose concentration one hour after a glucose load, blood pressure, and body weight were measured in 1968, 1974, and 1979. In 1986 blood pressure and body weight were recorded.
RESULTS Men who were hypertensive in 1986 had significantly higher blood pressures (p less than 0.0001) and (after adjustment for body mass index and alcohol intake) significantly higher blood glucose concentrations one hour after a glucose load at all examinations than those who were normotensive in 1986. Regression analysis showed that the higher the blood glucose concentration after a glucose load in 1968 the higher the blood pressure during the following years. Those men between the second and third tertiles of blood glucose concentration in 1968 had a significantly higher risk of developing hypertension (odds ratio 1.71, 95% confidence interval 1.05 to 2.77) compared with those below the first tertile.
CONCLUSION In this study men who developed hypertension tended to have shown an increased intolerance to glucose up to 18 years before the clinical manifestation of their disorder. Blood glucose concentration one hour after a glucose load was an independent predictor of future hypertension. | Glucose tolerance and blood pressure: long term follow up in middle aged men. |
39381118 | Apoptosis that proceeds via the mitochondrial pathway involves mitochondrial outer membrane permeabilization (MOMP), responsible for the release of cytochrome c and other proteins of the mitochondrial intermembrane space. This essential step is controlled and mediated by proteins of the Bcl-2 family. The proapoptotic proteins Bax and Bak are required for MOMP, while the antiapoptotic Bcl-2 proteins, including Bcl-2, Bcl-xL, Mcl-1, and others, prevent MOMP. Different proapoptotic BH3-only proteins act to interfere with the function of the antiapoptotic Bcl-2 members and/or activate Bax and Bak. Here, we discuss an emerging view, proposed by Certo et al. in this issue of Cancer Cell, on how these interactions result in MOMP and apoptosis. | At the gates of death. |
39389082 | We report here crystal structures of human RNase H1 complexed with an RNA/DNA substrate. Unlike B. halodurans RNase H1, human RNase H1 has a basic protrusion, which forms a DNA-binding channel and together with the conserved phosphate-binding pocket confers specificity for the B form and 2'-deoxy DNA. The RNA strand is recognized by four consecutive 2'-OH groups and cleaved by a two-metal ion mechanism. Although RNase H1 is overall positively charged, the substrate interface is neutral to acidic in character, which likely contributes to the catalytic specificity. Positions of the scissile phosphate and two catalytic metal ions are interdependent and highly coupled. Modeling of HIV reverse transcriptase (RT) with RNA/DNA in its RNase H active site suggests that the substrate cannot simultaneously occupy the polymerase active site and must undergo a conformational change to toggle between the two catalytic centers. The region that accommodates this conformational change offers a target to develop HIV-specific inhibitors. | Structure of human RNase H1 complexed with an RNA/DNA hybrid: insight into HIV reverse transcription. |
39390206 | OBJECTIVE To measure in vivo, using diffusion tensor magnetic resonance imaging (DT-MRI) the extent of pathological damage of normal appearing brain tissue (NABT) from patients with migraine.
METHODS Dual echo and DT-MRI scans of the brain were acquired from 34 patients with migraine and 17 sex and age matched healthy volunteers. Mean diffusivity (MD) and fractional anisotropy (FA) histograms of the NABT were obtained from all subjects and the histograms' peak heights and average NABT MD and FA measured. When present, average MD and FA values of T2 visible lesions were also measured.
RESULTS In comparison with healthy volunteers, patients with migraine had lower MD histogram peak height (p=0.02) of the NABT. No differences were found in FA histogram derived metrics between migraine patients and healthy subjects. No difference was found for any MD and FA histogram derived metrics between migraine patients with and without brain MRI lesions, and between patients with and without aura.
CONCLUSIONS This study shows that, although brain damage may extend beyond T2 weighted abnormalities in patients with migraine, the severity of these "occult" changes is mild compared with that found in other diseases associated with white matter abnormality. | A diffusion tensor magnetic resonance imaging study of brain tissue from patients with migraine. |
39391953 | A sensitive biotin-streptavidin amplified enzyme-linked immunosorbent assay (BA-ELISA) method was developed for the determination of chloramphenicol residues in milk. The biotin-streptavidin system was applied to enhance the sensitivity. After optimization, the detection limit of the method was found to be 0.042 +/- 0.006 ng mL(-1), which is 8-fold more sensitive than the traditional competitive ELISA using the same antibody and coating antigen. The amplification mechanism of the biotin-streptavidin system and the major factors affecting the sensitivity of detection are discussed. This method was successfully applied to determine the chloramphenicol residues in milk samples with a simple and rapid extraction procedure, and good recoveries (85.66-109.67%) were obtained. The result indicated that the biotin-streptavidin system may be a valuable tool to improve the specific detection of trace veterinary drug residues and could be widely used for routine monitoring of food samples. | Determination of chloramphenicol residues in milk by enzyme-linked immunosorbent assay: improvement by biotin-streptavidin-amplified system. |
39424916 | Wedelolactone is a major coumarin of Eclipta prostrata, which is used for preventing liver damage. However the effects of wedelolactone on hepatic fibrosis remained unexplored. The purpose of this study was to demonstrate the anti-fibrotic effects of wedelolactone on activated human hepatic stellate cell (HSC) line LX-2 and the possible underlying mechanisms by means of MTT assay, Hoechst staining, as well as real-time quantitative PCR and western blot. The results showed that wedelolactone reduced the cellular viability of LX-2 in a time and dose-dependent manner. After treatment of wedelolactone, the expressions of collagen I and α-smooth muscle actin, two biomarkers of LX-2 activation, were remarkably decreased. The apoptosis of LX-2 cells was induced by wedelolactone accompanied with the decreasing expression of anti-apoptotic Bcl-2 and increasing expression of pro-apoptotic Bax. In addition, phosphorylated status of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was up-regulated, but not in p38. Moreover, wedelolactone significantly repressed the level of phosphorylated inhibitor of nuclear factor κB (IκB) and p65 in nucleus in spite of tumor necrosis factor-α stimulation. In conclusion, wedelolactone could significantly inhibit the activation of LX-2 cells, the underlying mechanisms of which included inducing Bcl-2 family involved apoptosis, up-regulating phosphorylated status of ERK and JNK expressions, and inhibiting nuclear factor-κB (NF-κB) mediated activity. Wedelolactone might present as a useful tool for the prevention and treatment of hepatic fibrosis. | Wedelolactone exhibits anti-fibrotic effects on human hepatic stellate cell line LX-2. |
39426225 | Recent research has shown that adipose tissues contain abundant MSCs (mesenchymal stem cells). The origin and location of the adipose stem cells, however, remain unknown, presenting an obstacle to the further purification and study of these cells. In the present study, we aimed at investigating the origins of adipose stem cells. α-SMA (α-smooth muscle actin) is one of the markers of pericytes. We harvested ASCs (adipose stromal cells) from α-SMA-GFP (green fluorescent protein) transgenic mice and sorted them into GFP-positive and GFP-negative cells by FACS. Multilineage differentiation tests were applied to examine the pluripotent ability of the α-SMA-GFP-positive and -negative cells. Immunofluorescent staining for α-SMA and PDGF-Rβ (platelet-derived growth factor receptor β) were applied to identify the α-SMA-GFP-positive cells. Then α-SMA-GFP-positive cells were loaded on a collagen-fibronectin gel with endothelial cells to test their vascularization ability both in vitro and in vivo. Results show that, in adipose tissue, all of the α-SMA-GFP-positive cells congregate around the blood vessels. Only the α-SMA-GFP-positive cells have multilineage differentiation ability, while the α-SMA-GFP-negative cells can only differentiate in an adipogenic direction. The α-SMA-GFP-positive cells maintained expression of α-SMA during multilineage differentiation. The α-SMA-GFP-positive cells can promote the vascularization of endothelial cells in three-dimensional culture both in vitro and in vivo. We conclude that the adipose stem cells originate from perivascular cells and congregate around blood vessels. | Adipose stem cells originate from perivascular cells. |
39443128 | Adult T-cell leukaemia lymphoma (ATLL) is an aggressive disease caused by the human T-lymphotropic virus 1 (HTLV-I) with a short survival. Responses to interferon alpha (IFN-alpha) and zidovudine (AZT) have been documented but not with long-term follow-up. We treated 15 ATLL patients with IFN and AZT. Eleven patients had acute ATLL, two had lymphoma and two smouldering ATLL, with progression. The main features were: organomegaly (14), skin lesions (10), high white blood cell (WBC) count (11) and hypercalcaemia (9). Eleven patients had previously received chemotherapy and one had received an autograft. At the time of the study, seven patients had progressive disease and eight were in partial or complete clinical remission. Responses (PR) lasting 2+ to 44+ months were seen in 67%; 26% did not respond (NR) and one patient was not evaluable. Hypercalcaemia predicted a poor outcome but differences were not significant. Eight of the 15 patients have died 3-41 months from diagnosis. Median survival for the 15 patients was 18 months. Survival of the NR ranged from 4 to 20 months; six PR patients are alive 8-82 months from diagnosis. The differences in survival between NR (median: 6 months) and PR (55% of patients alive at 4 years) were statistically significant (P = 0.002). In conclusion, IFN and AZT improves the outcome of ATLL patients and helps maintain responses. | Interferon alpha and zidovudine therapy in adult T-cell leukaemia lymphoma: response and outcome in 15 patients. |
39462488 | Expanded CGG repeats cause chromosomal fragility and hereditary neurological disorders in humans. Replication forks stall at CGG repeats in a length-dependent manner in primate cells and in yeast. Saccharomyces cerevisiae proteins Tof1 and Mrc1 facilitate replication fork progression through CGG repeats. Remarkably, the fork-stabilizing role of Mrc1 does not involve its checkpoint function. Thus, chromosomal fragility might occur when forks stalled at expanded CGG repeats escape the S-phase checkpoint. | Replisome stalling and stabilization at CGG repeats, which are responsible for chromosomal fragility |
39465575 | Recent studies have shown that defined sets of transcription factors can directly reprogram differentiated somatic cells to a different differentiated cell type without passing through a pluripotent state, but the restricted proliferative and lineage potential of the resulting cells limits the scope of their potential applications. Here we show that a combination of transcription factors (Brn4/Pou3f4, Sox2, Klf4, c-Myc, plus E47/Tcf3) induces mouse fibroblasts to directly acquire a neural stem cell identity-which we term as induced neural stem cells (iNSCs). Direct reprogramming of fibroblasts into iNSCs is a gradual process in which the donor transcriptional program is silenced over time. iNSCs exhibit cell morphology, gene expression, epigenetic features, differentiation potential, and self-renewing capacity, as well as in vitro and in vivo functionality similar to those of wild-type NSCs. We conclude that differentiated cells can be reprogrammed directly into specific somatic stem cell types by defined sets of specific transcription factors. | Direct reprogramming of fibroblasts into neural stem cells by defined factors. |
39481265 | PURPOSE OF REVIEW Idiopathic pulmonary fibrosis (IPF) is a fatal disease with limited treatment options and extensive gene expression changes identified in the lung parenchyma. Multiple lines of evidence suggest that epigenetic factors contribute to dysregulation of gene expression in IPF lung. Most importantly, risk factors that predispose to IPF - age, sex, cigarette smoke, and genetic variants - all influence epigenetic marks. This review summarizes recent findings of association of DNA methylation and histone modifications with the presence of disease and fibroproliferation. RECENT FINDINGS In addition to targeted studies focused on specific gene loci, genome-wide profiles of DNA methylation demonstrate widespread DNA methylation changes in IPF lung tissue and a substantial effect of these methylation changes on gene expression. Genetic loci that have been recently associated with IPF also contain differentially methylated regions, suggesting that genetic and epigenetic factors act in concert to dysregulate gene expression in IPF lung. SUMMARY Although we are in very early stages of understanding the role of epigenetics in IPF, the potential for the use of epigenetic marks as biomarkers and therapeutic targets is high and discoveries made in this field will likely bring us closer to better prognosticating and treating this fatal disease. | Epigenetics in lung fibrosis: from pathobiology to treatment perspective. |
39506601 | KLF1 (formerly known as EKLF) regulates the development of erythroid cells from bi-potent progenitor cells via the transcriptional activation of a diverse set of genes. Mice lacking Klf1 die in utero prior to E15 from severe anemia due to the inadequate expression of genes controlling hemoglobin production, cell membrane and cytoskeletal integrity, and the cell cycle. We have recently described the full repertoire of KLF1 binding sites in vivo by performing KLF1 ChIP-seq in primary erythroid tissue (E14.5 fetal liver). Here we describe the KLF1-dependent erythroid transcriptome by comparing mRNA-seq from Klf1(+/+) and Klf1(-/-) erythroid tissue. This has revealed novel target genes not previously obtainable by traditional microarray technology, and provided novel insights into the function of KLF1 as a transcriptional activator. We define a cis-regulatory module bound by KLF1, GATA1, TAL1, and EP300 that coordinates a core set of erythroid genes. We also describe a novel set of erythroid-specific promoters that drive high-level expression of otherwise ubiquitously expressed genes in erythroid cells. Our study has identified two novel lncRNAs that are dynamically expressed during erythroid differentiation, and discovered a role for KLF1 in directing apoptotic gene expression to drive the terminal stages of erythroid maturation. | Novel roles for KLF1 in erythropoiesis revealed by mRNA-seq. |
39532074 | INTRODUCTION The hostile environment after spinal cord injury (SCI) can compromise effects of regenerative therapies. We hypothesized that optimizing the post-traumatic environment with QL6 self-assembling peptides (SAPs) before neural precursor cell (NPC) transplantation would improve cell survival, differentiation and functional recovery.
METHODS A total of 90 Wistar rats received a clip-compression SCI at C7. Within each of two study arms, animals were randomized into 5 groups (NPC, SAP, NPC+SAP, vehicle, and sham). SAPs and NPCs were injected into the spinal cord 1day and 14days post-injury, respectively. Animals received growth factors over 7days and were immunosuppressed. Rats were sacrificed at 4weeks and sections of the cervical spinal cord prepared for immunohistochemistry (first study arm). Neurological function was assessed weekly for 8weeks using a battery of behavioral tests. Nine weeks post-SCI, the corticospinal tract was assessed using fiber-tracking (second arm).
RESULTS SAP-treated animals had significantly more surviving NPCs which showed increased differentiation to neurons and oligodendrocytes compared to controls. SAPs alone or in combination with NPCs resulted in smaller intramedullary cysts and larger volume of preserved tissue compared to other groups. The combined treatment group showed reduced astrogliosis and chondroitin sulfate proteoglycan deposition. Synaptic connectivity was increased in the NPC and combined treatment groups. Corticospinal tract preservation and behavioral outcomes improved with combinatorial treatment.
CONCLUSION Injecting SAPs after SCI enhances subsequent NPC survival, integration and differentiation and improves functional recovery. STATEMENT OF SIGNIFICANCE The hostile environment after spinal cord injury (SCI) can compromise effects of regenerative therapies. We hypothesized that improving this environment with self-assembling peptides (SAPs) before neural precursor cell (NPC) transplantation would support their beneficial effects. SAPs assemble once injected, providing a supportive scaffold for repair and regeneration. We investigated this in a rat model of spinal cord injury. More NPCs survived in SAP-treated animals and these showed increased differentiation compared to controls. SAPS alone or in combination with NPCs resulted in smaller cysts and larger volume of preserved tissue with the combined treatment also reducing scarring and improving behavioral outcomes. Overall, injection of SAPs was shown to improve the efficacy of NPC treatment, a promising finding for those with SCIs. | Self-assembling peptides optimize the post-traumatic milieu and synergistically enhance the effects of neural stem cell therapy after cervical spinal cord injury. |
39539647 | IL-12 has been identified as a major cytokine influencing the differentiation of CD4 cells to a Th1 phenotype, whereas a role for IFN-gamma is controversial. We investigated the interrelationship between IL-12 and IFN-gamma in promoting Th1 responses using naive CD4 cells reactive with pigeon cytochrome c from TCR transgenics and memory CD4 cells derived by in vivo priming with KLH. Without exogenous rIL-12 or rIFN-gamma, primary and memory effectors induced by Ag or anti-CD3 and anti-CD28 secreted variable levels of IL-2 and IFN-gamma. The level of IFN-gamma secreted by effectors correlated with endogenous IFN-gamma produced in primary cultures, and anti-IFN-gamma largely inhibited the development of effectors producing IFN-gamma. With optimal TCR stimulation and costimulation, endogenous IFN-gamma, without IL-12, was sufficient to elicit Th1 cells via an autocrine mechanism, whereas with suboptimal stimulation, exogenous rIFN-gamma or rIL-12 was required for Th1 development. However, rIL-12 was more effective than rIFN-gamma, partially because rIL-12 greatly enhanced autocrine production of IFN-gamma, and optimal development of the Th1 phenotype was mediated by the synergistic actions of both cytokines. Thus, both IFN-gamma and IL-12 can independently regulate Th1 development, but because of IFN-gamma-mediated feedback, their relative contributions are determined by the conditions of T cell stimulation. The extent of differentiation to a Th1 phenotype may, therefore, depend on the availability of both APC-derived IL-12 and autocrine IFN-gamma consequent to the overall strength of T cell stimulation. | A direct role for IFN-gamma in regulation of Th1 cell development. |
39545358 | Neuregulin 1 (NRG1) and its receptor ErbB4 are both susceptibility genes of schizophrenia. However, little is known about the underlying mechanisms of their malfunction. Although ErbB4 is enriched in GABAergic interneurons, the role of NRG1 in excitatory synapse formation in these neurons remains poorly understood. We showed that NRG1 increased both the number and size of PSD-95 puncta and the frequency and amplitude of miniature EPSCs (mEPSCs) in GABAergic interneurons, indicating that NRG1 stimulates the formation of new synapses and strengthens existing synapses. In contrast, NRG1 treatment had no effect on either the number or size of excitatory synapses in glutamatergic neurons, suggesting its synaptogenic effect is specific to GABAergic interneurons. Ecto-ErbB4 treatment diminished both the number and size of excitatory synapses, suggesting that endogenous NRG1 may be critical for basal synapse formation. NRG1 could stimulate the stability of PSD-95 in the manner that requires tyrosine kinase activity of ErbB4. Finally, deletion of ErbB4 in parvalbumin-positive interneurons led to reduced frequency and amplitude of mEPSCs, providing in vivo evidence that ErbB4 is important in excitatory synaptogenesis in interneurons. Together, our findings suggested a novel synaptogenic role of NRG1 in excitatory synapse development, possibly via stabilizing PSD-95, and this effect is specific to GABAergic interneurons. In light of the association of the genes of both NRG1 and ErbB4 with schizophrenia and dysfunction of GABAergic system in this disorder, these results provide insight into its potential pathological mechanism. | Neuregulin 1 promotes excitatory synapse development and function in GABAergic interneurons. |
39550665 | BACKGROUND & AIMS Chronic infection with the bacterial pathogen Helicobacter pylori causes gastric disorders, ranging from chronic gastritis to gastric adenocarcinoma. Only a subset of infected persons will develop overt disease; most remains asymptomatic despite lifelong colonization. This study aims to elucidate the differential susceptibility to H pylori that is found both across and within populations.
METHODS We have established a C57BL/6 mouse model of H pylori infection with a strain that is capable of delivering the virulence factor cytotoxin-associated gene A (CagA) into host cells through the activity of a Cag-pathogenicity island-encoded type IV secretion system.
RESULTS Mice infected at 5-6 weeks of age with CagA(+)H pylori rapidly develop gastritis, gastric atrophy, epithelial hyperplasia, and metaplasia in a type IV secretion system-dependent manner. In contrast, mice infected during the neonatal period with the same strain are protected from preneoplastic lesions. Their protection results from the development of H pylori-specific peripheral immunologic tolerance, which requires transforming growth factor-β signaling and is mediated by long-lived, inducible regulatory T cells, and which controls the local CD4(+) T-cell responses that trigger premalignant transformation. Tolerance to H pylori develops in the neonatal period because of a biased ratio of T-regulatory to T-effector cells and is favored by prolonged low-dose exposure to antigen.
CONCLUSIONS Using a novel CagA(+)H pylori infection model, we report here that the development of tolerance to H pylori protects from gastric cancer precursor lesions. The age at initial infection may thus account for the differential susceptibility of infected persons to H pylori-associated disease manifestations. | Tolerance rather than immunity protects from Helicobacter pylori-induced gastric preneoplasia. |
39558597 | Aging is associated with impaired fasted oxidation of nonesterified fatty acids (NEFA) suggesting a mitochondrial defect. Aging is also associated with deficiency of glutathione (GSH), an important mitochondrial antioxidant, and with insulin resistance. This study tested whether GSH deficiency in aging contributes to impaired mitochondrial NEFA oxidation and insulin resistance, and whether GSH restoration reverses these defects. Three studies were conducted: (i) in 82-week-old C57BL/6 mice, the effect of naturally occurring GSH deficiency and its restoration on mitochondrial (13) C1 -palmitate oxidation and glucose metabolism was compared with 22-week-old C57BL/6 mice; (ii) in 20-week C57BL/6 mice, the effect of GSH depletion on mitochondrial oxidation of (13) C1 -palmitate and glucose metabolism was studied; (iii) the effect of GSH deficiency and its restoration on fasted NEFA oxidation and insulin resistance was studied in GSH-deficient elderly humans, and compared with GSH-replete young humans. Chronic GSH deficiency in old mice and elderly humans was associated with decreased fasted mitochondrial NEFA oxidation and insulin resistance, and these defects were reversed with GSH restoration. Acute depletion of GSH in young mice resulted in lower mitochondrial NEFA oxidation, but did not alter glucose metabolism. These data suggest that GSH is a novel regulator of mitochondrial NEFA oxidation and insulin resistance in aging. Chronic GSH deficiency promotes impaired NEFA oxidation and insulin resistance, and GSH restoration reverses these defects. Supplementing diets of elderly humans with cysteine and glycine to correct GSH deficiency could provide significant metabolic benefits. | Impaired mitochondrial fatty acid oxidation and insulin resistance in aging: novel protective role of glutathione. |
39559521 | The negative selection of self-reactive thymocytes depends on the expression of tissue-specific antigens by medullary thymic epithelial cells. The autoimmune regulator (Aire) protein plays an important role in turning on these antigens, and the absence of even one Aire-induced tissue-specific antigen in the thymus can lead to autoimmunity in the antigen-expressing target organ. Recently, Aire protein has been detected in peripheral lymphoid organs, suggesting that peripheral Aire plays a complementary role here. In these peripheral sites, Aire was found to regulate the expression of a group of tissue-specific antigens that is distinct from those expressed in the thymus. Furthermore, transgenic antigen expression in extrathymic Aire-expressing cells (eTACs) can mediate deletional tolerance, but the immunological relevance of Aire-dependent, endogenous tissue-specific antigens remains to be determined. | Control of central and peripheral tolerance by Aire. |
39571812 | Reproductive function depends on the activity of the gonadotropic axis, which is controlled by a hypothalamic neural network whose main function is to regulate the secretion of gonadotropin-releasing hormone (GnRH). This endocrine network is not mature at birth, and several phases of activation-inactivation of the gonadotropic axis are necessary for its normal development. The postnatal maturation of the GnRH network lies under the control of a neurodevelopmental program that starts in fetal life and ends at puberty. There are many clinical situations in which this program is interrupted, leading to congenital hypogonadotropic hypogonadism (CHH) and an absence of puberty. For many years, attention has mainly been focused on the genetics of isolated CHH. More recently, the emergence of new genomics techniques has led to the description of genetic defects in very rare syndromes in which CHH is associated with complex neurological dysfunctions. Here, we review the clinical phenotype and genetic defects linked to such syndromic CHH. This analysis highlights the close link between the ubiquitin pathway, synaptic proteins and CHH, as well as unexpected mutations in genes encoding nucleolar proteins. | Congenital Hypogonadotropic Hypogonadism: A Trait Shared by Several Complex Neurodevelopmental Disorders. |
39580129 | OBJECTIVES Several miRNAs are aberrantly expressed in cancer. miR-24-3p is involved in cancer-related cellular processes, including cell cycle control, cell growth, proliferation, and apoptosis. In this study, we examined the potential diagnostic and prognostic significance of miR-24-3p expression in colorectal adenocarcinoma.
DESIGN AND METHODS Total RNA was isolated from 182 colorectal adenocarcinoma specimens and 86 paired non-cancerous colorectal mucosae. After polyadenylation of 2μg total RNA and reverse transcription into first-strand cDNA using an oligo-dT-adapter primer, miR-24-3p expression was quantified using an in-house-developed reverse-transcription real-time quantitative PCR method, based on the SYBR Green chemistry. SNORD43 (RNU43) was used as a reference gene.
RESULTS miR-24-3p levels do not significantly differ between colorectal adenocarcinoma and non-cancerous colorectal mucosae. Thus, miR-24-3p expression cannot be used for diagnostic purposes. However, high miR-24-3p expression predicts poor disease-free survival (DFS) and overall survival (OS) of colorectal adenocarcinoma patients. Multivariate Cox regression analysis confirmed that miR-24-3p overexpression is a significant predictor of relapse in colorectal adenocarcinoma and that its prognostic significance is independent of other established prognostic factors and treatment of patients. Of note, miR-24-3p overexpression retains its rather unfavorable prognostic value in the subgroup of patients with advanced yet locally restricted colorectal adenocarcinoma (T3) and in those without distant metastasis (M0). Moreover, miR-24-3p overexpression is a potentially unfavorable prognosticator for patients who were not treated with radiotherapy.
CONCLUSIONS Strong expression of miR-24-3p predicts poor DFS and OS of colorectal adenocarcinoma patients, independently of clinicopathological parameters that are currently used for prognosis in this human malignancy. | Elevated expression of miR-24-3p is a potentially adverse prognostic factor in colorectal adenocarcinoma. |
39593548 | Policy analysis is an established discipline in the industrialized world, yet its application to developing countries has been limited. The health sector in particular appears to have been neglected. This is surprising because there is a well recognized crisis in health systems, and prescriptions abound of what health policy reforms countries should introduce. However, little attention has been paid to how countries should carry out reforms, much less who is likely to favour or resist such policies. This paper argues that much health policy wrongly focuses attention on the content of reform, and neglects the actors involved in policy reform (at the international, national sub-national levels), the processes contingent on developing and implementing change and the context within which policy is developed. Focus on policy content diverts attention from understanding the processes which explain why desired policy outcomes fail to emerge. The paper is organized in 4 sections. The first sets the scene, demonstrating how the shift from consensus to conflict in health policy established the need for a greater emphasis on policy analysis. The second section explores what is meant by policy analysis. The third investigates what other disciplines have written that help to develop a framework of analysis. And the final section suggests how policy analysis can be used not only to analyze the policy process, but also to plan. | Reforming the health sector in developing countries: the central role of policy analysis. |
39637840 | BLM, WRN, and p53 are involved in the homologous DNA recombination pathway. The DNA structure-specific helicases, BLM and WRN, unwind Holliday junctions (HJ), an activity that could suppress inappropriate homologous recombination during DNA replication. Here, we show that purified, recombinant p53 binds to BLM and WRN helicases and attenuates their ability to unwind synthetic HJ in vitro. The p53 248W mutant reduces abilities of both to bind HJ and inhibit helicase activities, whereas the p53 273H mutant loses these abilities. Moreover, full-length p53 and a C-terminal polypeptide (residues 373-383) inhibit the BLM and WRN helicase activities, but phosphorylation at Ser(376) or Ser(378) completely abolishes this inhibition. Following blockage of DNA replication, Ser(15) phospho-p53, BLM, and RAD51 colocalize in nuclear foci at sites likely to contain DNA replication intermediates in cells. Our results are consistent with a novel mechanism for p53-mediated regulation of DNA recombinational repair that involves p53 post-translational modifications and functional protein-protein interactions with BLM and WRN DNA helicases. | The processing of Holliday junctions by BLM and WRN helicases is regulated by p53. |
39652608 | We study recently developed nonparametric methods for estimating the number of missing studies that might exist in a meta-analysis and the effect that these studies might have had on its outcome. These are simple rank-based data augmentation techniques, which formalize the use of funnel plots. We show that they provide effective and relatively powerful tests for evaluating the existence of such publication bias. After adjusting for missing studies, we find that the point estimate of the overall effect size is approximately correct and coverage of the effect size confidence intervals is substantially improved, in many cases recovering the nominal confidence levels entirely. We illustrate the trim and fill method on existing meta-analyses of studies in clinical trials and psychometrics. | Trim and fill: A simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis. |
39661951 | A family with six cases of Barrett's esophagus over three generations is described. The Barrett's esophagus affected only males, and there were three associated adenocarcinomas. The mechanism of inheritance is compatible with an autosomal dominant pattern with nearly complete penetrance. Other case reports in the literature are compared with this familial case of Barrett's esophagus with associated adenocarcinomas. | Familial Barrett's esophagus associated with adenocarcinoma. |
39668245 | Conventional in vivo assays to determine the relative pathogenicity of yeast isolates rely upon the use of a range of mammalian species. The purpose of the work presented here was to investigate the possibility of using an insect (Galleria mellonella) as a model system for in vivo pathogenicity testing. The haemolymph of G. mellonella larvae was inoculated with PBS containing different concentrations of stationary phase yeasts of the genus Candida by injection at the last pro-leg. Larvae were incubated at 30 degrees C and monitored over 72 hours. Results indicate that G. mellonella can be killed by the pathogenic yeast Candida albicans and by a range of other Candida species but not to a significant extent by the yeast Saccharomyces cerevisiae. The kill kinetics for larvae inoculated with clinical and laboratory isolates of C. albicans indicate the former class of isolates to be more pathogenic. Differences in the relative pathogenicity of a range of Candida species may be distinguished using G. mellonella as a model. This work indicates that G. mellonella may be employed to give results consistent with data previously obtained using mammals in conventional in vivo pathogenicity testing. Larvae of G. mellonella are inexpensive to culture, easy to manipulate and their use may reduce the need to employ mammals for routine in vivo pathogenicity testing with a concomitant reduction in mammalian suffering. | Development of an insect model for the in vivo pathogenicity testing of yeasts. |
39728826 | An essential step in macromolecular refinement is the selection of model parameters which give as good a description of the experimental data as possible while retaining a realistic data-to-parameter ratio. This is particularly true of the choice of atomic displacement parameters, where the move from individual isotropic to individual anisotropic refinement involves a sixfold increase in the number of required displacement parameters. The number of refinement parameters can be reduced by using collective variables rather than independent atomic variables and one of the simplest examples of this is the TLS parameterization for describing the translation, libration and screw-rotation displacements of a pseudo-rigid body. This article describes the implementation of the TLS parameterization in the macromolecular refinement program REFMAC. Derivatives of the residual with respect to the TLS parameters are expanded in terms of the derivatives with respect to individual anisotropic U values, which in turn are calculated using a fast Fourier transform technique. TLS refinement is therefore fast and can be used routinely. Examples of TLS refinement are given for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a transcription activator GerE, for both of which there is data to only 2.0 A, so that individual anisotropic refinement is not feasible. GAPDH has been refined with between one and four TLS groups in the asymmetric unit and GerE with six TLS groups. In both cases, inclusion of TLS parameters gives improved refinement statistics and in particular an improvement in R and free R values of several percent. Furthermore, GAPDH and GerE have two and six molecules in the asymmetric unit, respectively, and in each case the displacement parameters differ significantly between molecules. These differences are well accounted for by the TLS parameterization, leaving residual local displacements which are very similar between molecules and to which NCS restraints can be applied. | Use of TLS parameters to model anisotropic displacements in macromolecular refinement. |
39729277 | To characterize the sequence features surrounding the translation initiation sites on the genome of Synechocystis sp. strain 6803, the total proteins extracted from the cell were resolved by two-dimensional electrophoresis, and the amino-terminal sequences of the relatively abundant protein spots were determined. By comparison of the determined amino-terminal sequences with the nucleotide sequence of the entire genome, the translation initiation sites of a total of 72 proteins were successfully assigned on the genome. The sequence features emerged from the nucleotide sequences at and surrounding the translation initiation sites were as follows: (1) In addition to the three initiation codons, ATG, GTG, and TTG, evidence was obtained that ATT was also used as a rare initiation codon; (2) the core sequences (GAGG, GGAG and AGGA) of the Shine-Dalgarno sequence were identified in the appropriate position preceding the 35 initiation sites (48.6%); and (3) the preferential sequence surrounding the initiation codons was formulated as 5'-YY[...]R-3' where Y and R denote pyrimidine and purine nucleotides, respectively, and three dots represent the initiation codons. The result obtained would provide valuable information for improvement of the gene-finding software, and the approach used in this study should be applicable for comprehensive analysis of the expression profiles of cellular proteins. | Sequence features surrounding the translation initiation sites assigned on the genome sequence of Synechocystis sp. strain PCC6803 by amino-terminal protein sequencing. |
39758684 | To reach the biological alterations that characterize cancer, the genome of tumor cells must acquire increased mutability resulting from a malfunction of a network of genome stability systems, e.g., cell cycle arrest, DNA repair, and high accuracy of DNA synthesis during DNA replication. Numeric chromosomal imbalance, referred to as aneuploidy, is the most prevalent genetic changes recorded among many types of solid tumors. We report here that ectopic expression in cells of DNA polymerase beta, an error-prone enzyme frequently over-regulated in human tumors, induces aneuploidy, an abnormal localization of the centrosome-associated gamma-tubulin protein during mitosis, a deficient mitotic checkpoint, and promotes tumorigenesis in nude immunodeficient mice. Thus, we find that alteration of polymerase beta expression appears to induce major genetic changes associated with a malignant phenotype. | Deregulated DNA polymerase beta induces chromosome instability and tumorigenesis. |
39763465 | We have demonstrated previously that a combination of signals from the neural tube and the floor plate/notochord complex synergistically induce the expression of myogenic bHLH genes and myogenic differentiation markers in unspecified somites. In this study we demonstrate that Sonic hedgehog (Shh), which is expressed in the floor plate/notochord, and a subset of Wnt family members (Wnt-1, Wnt-3, and Wnt-4), which are expressed in dorsal regions of the neural tube, mimic the muscle inducing activity of these tissues. In combination, Shh and either Wnt-1 or Wnt-3 are sufficient to induce myogenesis in somitic tissue in vitro. Therefore, we propose that myotome formation in vivo may be directed by the combinatorial activity of Shh secreted by ventral midline tissues (floor plate and notochord) and Wnt ligands secreted by the dorsal neural tube. | Combinatorial signaling by Sonic hedgehog and Wnt family members induces myogenic bHLH gene expression in the somite. |
39776978 | The maintenance of adequate bone mass is dependent upon the controlled and timely removal of old, damaged bone. This complex process is performed by the highly specialized, multinucleated osteoclast. Over the past 15 years, a detailed picture has emerged describing the origins, differentiation pathways and activation stages that contribute to normal osteoclast function. This information has primarily been obtained by the development and skeletal analysis of genetically modified mouse models. Mice harboring mutations in specific genetic loci exhibit bone defects as a direct result of aberrations in normal osteoclast recruitment, formation or function. These findings include the identification of the RANK–RANKL–OPG system as a primary mediator of osteoclastogenesis, the characterization of ion transport and cellular attachment mechanisms and the recognition that matrix-degrading enzymes are essential components of resorptive activity. This Review focuses on the principal observations in osteoclast biology derived from genetic mouse models, and highlights emerging concepts that describe how the osteoclast is thought to contribute to the maintenance of adequate bone mass and integrity throughout life. | Advances in osteoclast biology: old findings and new insights from mouse models |