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32766786
PURPOSE In the initial report of the Lupron Depot Neoadjuvant Prostate Cancer Study Group patients who received 3 months of androgen deprivation had a significant decrease in the positive margin rate. We monitored these patients for 5 years and to our knowledge present the longest followup of any neoadjuvant trial. MATERIALS AND METHODS A multi-institutional prospective randomized trial was performed between February 1992 and April 1994 involving patients with stage cT2b prostate cancer, including 138 who received 3 months of leuprolide plus flutamide before radical prostatectomy and 144 who underwent radical prostatectomy only. Patients were followed every 6 months with serum prostate specific antigen (PSA) testing for 5 years. Biochemical recurrence was defined as PSA greater than 0.4 ng./ml. RESULTS At 5 years there was no difference in the biochemical recurrence rate. PSA was less than 0.4 ng./ml. in 64.8% of the patients in the neoadjuvant androgen ablation plus prostatectomy and 67.6% in the prostatectomy only group (p = 0.663). CONCLUSIONS Although 3 months of androgen deprivation before radical prostatectomy resulted in an apparently significant decrease in positive surgical margins, a 5-year followup does not indicate any difference in the recurrence rate. Until studies document improvement in biochemical or clinical recurrence with longer periods of treatment, induction androgen deprivation before radical prostatectomy is not indicated.
Neoadjuvant androgen ablation before radical prostatectomy in cT2bNxMo prostate cancer: 5-year results.
32770503
Massively parallel sequencing of cDNA has enabled deep and efficient probing of transcriptomes. Current approaches for transcript reconstruction from such data often rely on aligning reads to a reference genome, and are thus unsuitable for samples with a partial or missing reference genome. Here we present the Trinity method for de novo assembly of full-length transcripts and evaluate it on samples from fission yeast, mouse and whitefly, whose reference genome is not yet available. By efficiently constructing and analyzing sets of de Bruijn graphs, Trinity fully reconstructs a large fraction of transcripts, including alternatively spliced isoforms and transcripts from recently duplicated genes. Compared with other de novo transcriptome assemblers, Trinity recovers more full-length transcripts across a broad range of expression levels, with a sensitivity similar to methods that rely on genome alignments. Our approach provides a unified solution for transcriptome reconstruction in any sample, especially in the absence of a reference genome.
Full-length transcriptome assembly from RNA-Seq data without a reference genome.
32776084
Embryonic stem (ES) cell-derived clones and chimeras are often associated with growth abnormalities during fetal development, leading to the production of over/under-weight offspring that show elevated neonatal mortality and morbidity. Due to the role played by imprinted genes in controlling fetal growth, much of the blame is pointed at improper epigenetic reprogramming of cells used in the procedures. We have analyzed the expression pattern of two growth regulatory imprinted genes, namely insulin like growth factor II (Igf2) and H19, in mouse ES cells cultured under growth restricted conditions and after in vitro aging. Culture of cells with serum-depleted media (starvation) and at high cell density (confluence) increased the expression of both imprinted genes and led to aberrant methylation profiles of differentially methylated regions in key regulatory sites of Igf2 and H19. These findings confirm that growth constrained cultures of ES cells are associated with alterations to methylation of the regulatory domains and the expression patterns of imprinted genes, suggesting a possible role of epigenetic factors in the loss of developmental potential.
Growth restricted in vitro culture conditions alter the imprinted gene expression patterns of mouse embryonic stem cells.
32777637
BACKGROUND Concurrent use of multiple standing antipsychotics (antipsychotic polypharmacy) is increasingly common among both inpatients and outpatients. Although this has often been cited as a potential quality-of-care problem, reviews of research evidence on antipsychotic polypharmacy have not distinguished between appropriate versus inappropriate use. METHODS A MEDLINE search from 1966 to December 2007 was completed to identify studies comparing changes in symptoms, functioning, and/or side effects between patients treated with multiple antipsychotics and patients treated with a single antipsychotic. The studies were reviewed in two groups on the basis of whether prescribing was concordant with guideline recommendations for multiple-antipsychotic use. RESULTS A review of the literature, including three randomized controlled trials, found no support for the use of antipsychotic polypharmacy in patients without an established history of treatment resistance to multiple trials of monotherapy. In patients with a history of treatment resistance to multiple monotherapy trials, limited data support antipsychotic polypharmacy, but positive outcomes were primarily found in studies of clozapine augmented with a second-generation antipsychotic. DISCUSSION Research evidence is consistent with the goal of avoiding antipsychotic polypharmacy in patients who lack guideline-recommended indications for its use. The Joint Commission is implementing a core measure set for Hospital-Based Inpatient Psychiatric Services. Two of the measures address antipsychotic polypharmacy. The first measure assesses the overall rate. The second measure determines whether clinically appropriate justification has been documented supporting the use of more than one antipsychotic medication.
When is antipsychotic polypharmacy supported by research evidence? Implications for QI.
32787042
AIM To determine the outcome of patients that underwent liver resection for metastases from uveal melanoma. METHODS Over a 9-year period, patients referred with uveal melanoma metastases were included. Following treatment of primary uveal melanoma, high-risk patients were offered to be enrolled into a 6-monthly non-contrast liver magnetic resonance imaging (MRI) surveillance. Following detection of liver metastases, patients were staged with a contrast-enhanced (Primovist(®)) liver MRI, computer tomography (CT) of the thorax and staging laparoscopy. RESULTS 155 patients were referred with uveal melanoma liver metastases, of which 17 (11.0%) patients had liver resection and one patient was treated with percutaneous radio-frequency ablation. The majority of patients undergoing liver resection were treated with multiple metastectomies (n = 8) and three patients had major liver resections. The overall median survival for patients treated with surgery/ablation was 27 (14-90) months, and this was significantly better compared to patients treated palliatively [median = 8(1-30) months, P < 0.001]. Following surgery, 11 patients had recurrent disease [median = 13(6-36) months]. Patients who had undergone a major liver resection had a significantly poorer disease-free survival (P = 0.037). CONCLUSIONS Patients who can undergo surgical resection for metastatic uveal melanoma have a more favorable survival compared to those who do not.
The Liverpool uveal melanoma liver metastases pathway: outcome following liver resection.
32797183
Lineage analysis studies in the avian embryo have identified two types of smooth muscle cells (SMCs) in the tunica media of large elastic arteries; one that originates within the cardiac neural crest and is ectoderm in origin (Ect) and another that arises from local mesenchyme of mesodermal origin (Mes). To determine if differences in primary embryonic lineage can give rise to SMCs with stable differences in growth and differentiation properties, we isolated Ect and Mes SMCs from the Day 14 chick embryo aorta. We report that despite different primary embryonic origins, Ect and Mes SMCs express nearly identical levels of seven SMC differentiation markers in vitro, consistent with their common smooth muscle developmental fates in vivo. By contrast, Ect SMCs displayed a greater capacity for growth in serum-free medium than Mes SMCs, but only under conditions permitting short-range cell-cell interactions. Most of the peptide growth factors tested that might account for serum-independent growth (PDGF-AA, PDGF-BB, basic FGF, EGF, or activin) stimulated DNA synthesis to similar extents in Ect and Mes SMCs. However, we found dramatic, lineage-dependent differences in SMC responses to transforming growth factor-beta (TGF-beta). Exposure to TGF-beta 1 (0.4 to 400 pmole/liter) consistently increased DNA synthesis in Ect SMCs, whereas in paired cultures of Mes SMCs, TGF-beta 1 was growth inhibitory. In SMC cultures transfected with p3TP-lux, a luciferase reporter controlled by the TGF-beta 1-response elements of the human PAI-1 promoter, TGF-beta 1 (120 pM) produced 12 +/- 2-fold increases in luciferase activity in Ect SMCs and only 3 +/- 1.5-fold increases in Mes SMCs. Analysis of TGF-beta receptor phenotypes by Northern blot, radioligand binding, and crosslinking assays showed that Ect and Mes SMCs expressed similar levels of types I, II, and III TGF-beta receptors. However, using a polyclonal antibody specific for the chick type II TGF-beta receptor subunit, we demonstrate that Mes SMCs produce a fully glycosylated form of this protein while Ect SMCs elaborate only an unglycosylated type II TGF-beta receptor. These results show that Ect and Mes SMCs exhibit lineage-dependent differences in growth and receptor-mediated transcriptional responses to at least one important class of SMC morphogens and growth modifiers, e.g., the TGF-betas. Our findings suggest that different SMC populations within a common vessel wall may respond in lineage-dependent ways to signals that direct formation of the tunica media in the embryo and to factors involved in the progression of vascular disease later in life.
Smooth muscle lineage diversity in the chick embryo. Two types of aortic smooth muscle cell differ in growth and receptor-mediated transcriptional responses to transforming growth factor-beta.
32827351
Aqueous solutions of lead salts (1, 2) and saturated solutions of lead hydroxide (1) have been used as stains to enhance the electron-scattering properties of components of biological materials examined in the electron microscope. Saturated solutions of lead hydroxide (1), while staining more intensely than either lead acetate or monobasic lead acetate (l , 2), form insoluble lead carbonate upon exposure to air. The avoidance of such precipitates which contaminate surfaces of sections during staining has been the stimulus for the development of elaborate procedures for exclusion of air or carbon dioxide (3, 4). Several modifications of Watson's lead hydroxide stain (1) have recently appeared (5-7). All utilize relatively high pH (approximately 12) and one contains small amounts of tartrate (6), a relatively weak complexing agent (8), in addition to lead. These modified lead stains are less liable to contaminate the surface of the section with precipitated stain products. The stain reported here differs from previous alkaline lead stains in that the chelating agent, citrate, is in sufficient excess to sequester all lead present. Lead citrate, soluble in high concentrations in basic solutions, is a chelate compound with an apparent association constant (log Ka) between ligand and lead ion of 6.5 (9). Tissue binding sites, presumably organophosphates, and other anionic species present in biological components following fixation, dehydration, and plastic embedding apparently have a greater affinity for this cation than lead citrate inasmuch as cellular and extracellular structures in the section sequester lead from the staining solution. Alkaline lead citrate solutions are less likely to contaminate sections, as no precipitates form when droplets of fresh staining solution are exposed to air for periods of up to 30 minutes. The resultant staining of the sections is of high intensity in sections of Aralditeor Epon-embedded material. Cytoplasmic membranes, ribosomes, glycogen, and nuclear material are stained (Figs. 1 to 3). STAIN SOLUTION: Lead citrate is prepared by
THE USE OF LEAD CITRATE AT HIGH pH AS AN ELECTRON-OPAQUE STAIN IN ELECTRON MICROSCOPY
32850528
OBJECTIVE To evaluate serum amylase and lipase levels and the rate of acute pancreatitis in patients with type 2 diabetes and high cardiovascular risk randomized to liraglutide or placebo and observed for 3.5-5.0 years. RESEARCH DESIGN AND METHODS A total of 9,340 patients with type 2 diabetes were randomized to either liraglutide or placebo (median observation time 3.84 years). Fasting serum lipase and amylase were monitored. Acute pancreatitis was adjudicated in a blinded manner. RESULTS Compared with the placebo group, liraglutide-treated patients had increases in serum lipase and amylase of 28.0% and 7.0%, respectively. Levels were increased at 6 months and then remained stable. During the study, 18 (0.4% [1.1 events/1,000 patient-years of observation] [PYO]) liraglutide-treated and 23 (0.5% [1.7 events/1,000 PYO]) placebo patients had acute pancreatitis confirmed by adjudication. Most acute pancreatitis cases occurred ≥12 months after randomization. Liraglutide-treated patients with prior history of pancreatitis (n = 147) were not more likely to develop acute pancreatitis than similar patients in the placebo group (n = 120). Elevations of amylase and lipase levels did not predict future risk of acute pancreatitis (positive predictive value <1.0%) in patients treated with liraglutide. CONCLUSIONS In a population with type 2 diabetes at high cardiovascular risk, there were numerically fewer events of acute pancreatitis among liraglutide-treated patients (regardless of previous history of pancreatitis) compared with the placebo group. Liraglutide was associated with increases in serum lipase and amylase, which were not predictive of an event of subsequent acute pancreatitis.
Amylase, Lipase, and Acute Pancreatitis in People With Type 2 Diabetes Treated With Liraglutide: Results From the LEADER Randomized Trial.
32852283
BACKGROUND Although zoledronic acid (ZOL), a third-generation nitrogen-containing bisphosphonate, has been identified as an attractive therapeutic agent against breast cancer, prostate cancer, multiple myeloma as well as small-cell lung cancer (SCLC), as best as we are aware, the anti-tumor effect of ZOL upon non-small-cell lung cancer (NSCLC) remains to be effectively investigated. This study examined the effects of ZOL upon the line-1 tumor cell, using a murine lung adenocarcinoma cell line similar to the behavior of human lung adenocarcinoma. METHODS We investigated the anti-tumor effects of ZOL (3-100 microM) on line-1 tumor cells in vitro, including cellular proliferation, by means of an MTT assay, cell-cycle analysis by flow cytometry and by assessing the level of apoptosis by annexin V/propidium iodide (PI) and 4'-6-diamidino-2-phenylindole (DAPI) staining. Further, we evaluated the growth and survival of line-1 tumor cells following ZOL treatment (1 microg/kg/week) using an animal model. We also examined the in vivo cell-cycle pattern using lacZ-expressing line-1 cells (line-1/lacZ). RESULTS ZOL significantly slowed the line-1 tumor growth in a dose-dependent manner in vitro. The treated line-1 tumor cells typically arrested at the S/G2/M-phase of the cell-cycle following ZOL exposure, but no apoptotic cells could be detected by either annexin V/PI or DAPI staining. When the ZOL was washed out, the drug-inhibited cells continued to proliferate again and the cell-cycle prolongation elicited earlier by the drug, then disappeared. Within 72-96 h following drug removal, the cell-cycle of the treated cells revealed a similar distribution to that of the untreated controls. In vivo studies demonstrated that ZOL significantly slowed the line-1 tumor growth. Indeed, mice lived significantly longer when they had been ZOL-treated than was the case for untreated mice (p<0.05). Using line-1/lacZ cells, the in vivo cell-cycle distribution of line-1 tumor cells subsequent to ZOL exposure revealed S/G2/M-phase arrest that was identical to the in vitro culture. CONCLUSIONS ZOL maintains the potential to reduce tumor burden and prolong survival for murine pulmonary adenocarcinoma. The flow cytometrical analysis of cell-cycle demonstrated that ZOL induces no apoptosis but is able to arrest line-1 tumor cells at the S/G2/M-phase. Although the clinical relevance of these results warrants verification for human lung cancer patients, ZOL combined with chemotherapy and/or radiotherapy appears to be a new therapeutic strategy for the effective treatment of NSCLC.
Zoledronic acid is unable to induce apoptosis, but slows tumor growth and prolongs survival for non-small-cell lung cancers.
32906513
Recent elucidation of the role of central tolerance in preventing organ-specific autoimmunity has changed our concepts of self/nonself discrimination. This paradigmatic shift is largely attributable to the discovery of promiscuous expression of tissue-restricted self-antigens (TRAs) by medullary thymic epithelial cells (mTECs). TRA expression in mTECs mirrors virtually all tissues of the body, irrespective of developmental or spatio-temporal expression patterns. This review summarizes current knowledge on the cellular and molecular regulation of TRA expression in mTECs, outlines relevant mechanisms of antigen presentation and modes of tolerance induction, and discusses implications for the pathogenesis of autoimmune diseases and other biological processes such as fertility, pregnancy, puberty, and tumor defense.
A central role for central tolerance.
32909242
SETTING The rural health district of Hlabisa, KwaZulu-Natal, South Africa. OBJECTIVES To assess the acceptability and effectiveness of traditional healers as supervisors of tuberculosis (TB) treatment in an existing directly observed treatment, short-course (DOTS) programme. DESIGN An observational study comparing treatment outcomes among new TB patients in the three intervention sub-districts offered the additional option of traditional healers for directly observed treatment (DOT) supervision with those in the remainder of the district offered the standard range of options for DOT supervision (health facility, community health worker and lay persons). A comparison was also made of treatment outcomes between different options for DOT supervision. RESULTS A total of 3461 TB patients were registered in Hlabisa District from April 1999 to December 2000, of whom 2823 were discharged from hospital to the ambulatory DOT programme. Treatment outcomes were known for 1816 patients in Hlabisa District (275 patients in the intervention area and 1541 patients in the control area). There was no significant difference (P < 0.5) in treatment outcome in the intervention and control areas (77% vs. 75%). Among 275 patients with known outcomes in the intervention area, 48 patients were supervised by traditional healers and 227 patients supervised by people other than traditional healers. Treatment completion was not significantly higher among patients supervised by traditional healers than among patients supervised by other categories of DOT supervisor (88% vs. 75%, P = 0.3841). Interviews with 41 of 51 traditional healer patients who had completed treatment revealed high levels of satisfaction with the care received. CONCLUSIONS Traditional healers make an effective contribution to TB programme performance in this pilot scheme in Hlabisa district. Further evaluation will be necessary as this approach is scaled up.
Contribution of traditional healers to a rural tuberculosis control programme in Hlabisa, South Africa.
32922179
There are many lines of evidence showing that oxidative stress and aberrant mitogenic changes have important roles in the pathogenesis of Alzheimer's disease (AD). However, although both oxidative stress and cell cycle-related abnormalities are early events, occurring before any cytopathology, the relation between these two events, and their role in pathophysiology was, until recently, unclear. However, on the basis of studies of mitogenic and oxidative stress signalling pathways in AD, we proposed a "two-hit hypothesis" which states that although either oxidative stress or abnormalities in mitotic signalling can independently serve as initiators, both processes are necessary to propagate disease pathogenesis. In this paper, we summarise evidence for oxidative stress and abnormal mitotic alterations in AD and explain the two-hit hypothesis by describing how both mechanisms are necessary and invariant features of disease.
Alzheimer's disease: the two-hit hypothesis.
32927401
Toll-like receptors are typically expressed in immune cells to regulate innate immunity. We found that functional Toll-like receptor 7 (TLR7) was expressed in C-fiber primary sensory neurons and was important for inducing itch (pruritus), but was not necessary for eliciting mechanical, thermal, inflammatory and neuropathic pain in mice. Our results indicate that TLR7 mediates itching and is a potential therapeutic target for anti-itch treatment in skin disease conditions.
Toll-like receptor 7 mediates pruritus
32927475
Class I-b genes constitute the majority of MHC class I loci. These monomorphic or oligomorphic molecules have been described in many organisms; they are best characterized in the mouse, which contains a substantial number of potentially intact genes. Two main characteristics differentiate class I-b from class I-a molecules: limited polymorphism and lower cell surface expression. These distinguishing features suggest possible generalizations regarding the evolution and function of this class. Additionally, class I-b proteins tend to have shorter cytoplasmic domains or in some cases may be secreted or may substitute a lipid anchor for the transmembrane domain. Some are also expressed in a limited distribution of cells or tissues. At least six mouse MHC class I-b molecules have been shown to present antigens to alpha beta or gamma delta T cells. Recent advances have provided insight into the physiological function of H-2M3a and have defined the natural peptide-binding motif of Qa-2. In addition, significant progress has been made toward better understanding of other class I-b molecules, including Qa-1, TL, HLA-E, HLA-G, and the MHC-unlinked class I molecule CD1. We begin this review, however, by arguing that the dichotomous categorization of MHC genes as class I-a and I-b is conceptually misleading, despite its historical basis and practical usefulness. With these reservations in mind, we then discuss antigen presentation by MHC class I-b molecules with particular attention to their structure, polymorphism, requirements for peptide antigen binding and tissue expression.
Antigen presentation by major histocompatibility complex class I-B molecules.
32955023
The expansion of white adipose tissue (WAT) in obesity involves de novo differentiation of new adipocytes; however, the cellular origin of these cells remains unclear. Here, we utilize Zfp423(GFP) reporter mice to characterize adipose mural (Pdgfrβ(+)) cells with varying levels of the preadipocyte commitment factor Zfp423. We find that adipose tissue contains distinct mural populations, with levels of Zfp423 distinguishing adipogenic from inflammatory-like mural cells. Using our "MuralChaser" lineage tracking system, we uncover adipose perivascular cells as developmental precursors of adipocytes formed in obesity, with adipogenesis and precursor abundance regulated in a depot-dependent manner. Interestingly, Pdgfrβ(+) cells do not significantly contribute to the initial cold-induced recruitment of beige adipocytes in WAT; it is only after prolonged cold exposure that these cells differentiate into beige adipocytes. These results provide genetic evidence for a mural cell origin of white adipocytes in obesity and suggest that beige adipogenesis may originate from multiple sources.
Pdgfrβ+ Mural Preadipocytes Contribute to Adipocyte Hyperplasia Induced by High-Fat-Diet Feeding and Prolonged Cold Exposure in Adult Mice.
32969964
Although interest in clinical guidelines has never been greater, uncertainty persists about whether they are effective. The debate has been hampered by the lack of a rigorous overview. We have identified 59 published evaluations of clinical guidelines that met defined criteria for scientific rigour; 24 investigated guidelines for specific clinical conditions, 27 studied preventive care, and 8 looked at guidelines for prescribing or for support services. All but 4 of these studies detected significant improvements in the process of care after the introduction of guidelines and all but 2 of the 11 studies that assessed the outcome of care reported significant improvements. We conclude that explicit guidelines do improve clinical practice, when introduced in the context of rigorous evaluations. However, the size of the improvements in performance varied considerably.
Effect of clinical guidelines on medical practice: a systematic review of rigorous evaluations.
32975424
Threonine can be used aerobically as the sole source of carbon and energy by mutants of Escherichia coli K-12. The pathway used involves the conversion of threonine via threonine dehydrogenase to aminoketobutyric acid, which is further metabolized by aminoketobutyric acid ligase, forming acetyl coenzyme A and glycine. A strain devoid of serine transhydroxymethylase uses this pathway and excretes glycine as a waste product. Aminoketobutyric acid ligase activity was demonstrated after passage of crude extracts through Sephadex G100.
Threonine as a carbon source for Escherichia coli.
32985041
Nitric oxide (NO) has been linked to numerous physiological and pathophysiological events that are not readily explained by the well established effects of NO on soluble guanylyl cyclase. Exogenous NO S-nitrosylates cysteine residues in proteins, but whether this is an important function of endogenous NO is unclear. Here, using a new proteomic approach, we identify a population of proteins that are endogenously S-nitrosylated, and demonstrate the loss of this modification in mice harbouring a genomic deletion of neuronal NO synthase (nNOS). Targets of NO include metabolic, structural and signalling proteins that may be effectors for neuronally generated NO. These findings establish protein S-nitrosylation as a physiological signalling mechanism for nNOS.
Protein S-nitrosylation: a physiological signal for neuronal nitric oxide
33030946
Summary Hypoxia augments inflammatory responses and osteoclastogenesis by incompletely understood mechanisms. We identified COMMD1 as a cell‐intrinsic negative regulator of osteoclastogenesis that is suppressed by hypoxia. In human macrophages, COMMD1 restrained induction of NF‐&kgr;B signaling and a transcription factor E2F1‐dependent metabolic pathway by the cytokine RANKL. Downregulation of COMMD1 protein expression by hypoxia augmented RANKL‐induced expression of inflammatory and E2F1 target genes and downstream osteoclastogenesis. E2F1 targets included glycolysis and metabolic genes including CKB that enabled cells to meet metabolic demands in challenging environments, as well as inflammatory cytokine‐driven target genes. Expression quantitative trait locus analysis linked increased COMMD1 expression with decreased bone erosion in rheumatoid arthritis. Myeloid deletion of Commd1 resulted in increased osteoclastogenesis in arthritis and inflammatory osteolysis models. These results identify COMMD1 and an E2F‐metabolic pathway as key regulators of osteoclastogenic responses under pathological inflammatory conditions and provide a mechanism by which hypoxia augments inflammation and bone destruction. Graphical Abstract Figure. No Caption available. HighlightsCOMMD1 is a negative regulator of osteoclast differentiationCOMMD1 suppresses bone loss in RA and inflammatory arthritis and osteolysis modelsCOMMD1 negatively regulates E2F1‐dependent metabolic pathways in macrophagesHypoxia suppresses COMMD1 expression to augment osteoclastogenesis &NA; Pathways that promote osteoclastogenesis are well characterized but less is known about negative regulators that suppress pathological bone loss. Murata et al. identify COMMD1 as an inhibitor of osteoclastogenesis that restrains NF‐&kgr;B‐ and E2F1‐CKB‐mediated metabolic pathways in macrophages.
Hypoxia‐Sensitive COMMD1 Integrates Signaling and Cellular Metabolism in Human Macrophages and Suppresses Osteoclastogenesis
33036897
Tyrosol and farnesol are quorum-sensing molecules produced by Candida albicans which accelerate and block, respectively, the morphological transition from yeasts to hyphae. In this study, we have investigated the secretion of tyrosol by C. albicans and explored its likely role in biofilm development. Both planktonic (suspended) cells and biofilms of four C. albicans strains, including three mutants with defined defects in the Efg 1 and Cph 1 morphogenetic signaling pathways, synthesized extracellular tyrosol during growth at 37 degrees C. There was a correlation between tyrosol production and biomass for both cell types. However, biofilm cells secreted at least 50% more tyrosol than did planktonic cells when tyrosol production was related to cell dry weight. The addition of exogenous farnesol to a wild-type strain inhibited biofilm formation by up to 33% after 48 h. Exogenous tyrosol appeared to have no effect, but scanning electron microscopy revealed that tyrosol stimulated hypha production during the early stages (1 to 6 h) of biofilm development. Experiments involving the simultaneous addition of tyrosol and farnesol at different concentrations suggested that the action of farnesol was dominant, and 48-h biofilms formed in the presence of both compounds consisted almost entirely of yeast cells. When biofilm supernatants were tested for their abilities to inhibit or enhance germ tube formation by planktonic cells, the results indicated that tyrosol activity exceeds that of farnesol after 14 h, but not after 24 h, and that farnesol activity increases significantly during the later stages (48 to 72 h) of biofilm development. Overall, our results support the conclusion that tyrosol acts as a quorum-sensing molecule for biofilms as well as for planktonic cells and that its action is most significant during the early and intermediate stages of biofilm formation.
Production of tyrosol by Candida albicans biofilms and its role in quorum sensing and biofilm development.
33063763
MAP kinase signaling modules serve to transduce extracellular signals to the nucleus of eukaryotic cells, but little is known about how signals cross the nuclear envelope. Exposure of yeast cells to increases in extracellular osmolarity activates the HOG1 MAP kinase cascade, which is composed of three tiers of protein kinases, namely the SSK2, SSK22 and STE11 MAPKKKs, the PBS2 MAPKK, and the HOG1 MAPK. Using green fluorescent protein (GFP) fusions of these kinases, we found that HOG1, PBS2 and STE11 localize to the cytoplasm of unstressed cells. Following osmotic stress, HOG1, but neither PBS2 nor STE11, translocates into the nucleus. HOG1 translocation occurs very rapidly, is transient, and correlates with the phosphorylation and activation of the MAP kinase by its MAPKK. HOG1 phosphorylation is necessary and sufficient for nuclear translocation, because a catalytically inactive kinase when phosphorylated is translocated to the nucleus as efficiently as the wild-type. Nuclear import of the MAPK under stress conditions requires the activity of the small GTP binding protein Ran-GSP1, but not the NLS-binding importin alpha/beta heterodimer. Rather, HOG1 import requires the activity of a gene, NMD5, that encodes a novel importin beta homolog. Similarly, export of dephosphorylated HOG1 from the nucleus requires the activity of the NES receptor XPO1/CRM1. Our findings define the requirements for the regulated nuclear transport of a stress-activated MAP kinase.
Regulated nucleo/cytoplasmic exchange of HOG1 MAPK requires the importin beta homologs NMD5 and XPO1.
33068577
F-box and WD repeat domain-containing 7 (FBW7), the substrate-binding subunit of E3 ubiquitin ligase SCFFBW7 (a complex of SKP1, cullin-1 and FBW7), plays important roles in various physiological and pathological processes. Although FBW7 is required for vascular development, its function in the endothelium remains to be investigated. In this study, we show that FBW7 is an important regulator of endothelial functions, including angiogenesis, leukocyte adhesion and the endothelial barrier integrity. Using RNA interference, we found that the depletion of FBW7 markedly impairs angiogenesis in vitro and in vivo. We identified the zinc finger transcription factor Krüppel-like factor 2 (KLF2) as a physiological target of FBW7 in endothelial cells. Knockdown of FBW7 expression resulted in the accumulation of endogenous KLF2 protein in endothelial cells. FBW7-mediated KLF2 destruction was shown to depend on the phosphorylation of KLF2 via glycogen synthase kinase-3 (GSK3) at two conserved phosphodegrons. Mutating these phosphodegron motifs abolished the FBW7-mediated degradation and ubiquitination of KLF2. The siRNA-mediated knockdown of FBW7 showed that KLF2 is an essential target of FBW7 in the regulation of endothelial functions. Moreover, FBW7-mediated KLF2 degradation was shown to be critical for angiogenesis in teratomas and in zebrafish development. Taken together, our study suggests a role for FBW7 in the processes of endothelial cell migration, angiogenesis, inflammation and barrier integrity, and provides novel insights into the regulation of KLF2 stability in vivo.
FBW7 regulates endothelial functions by targeting KLF2 for ubiquitination and degradation
33076846
Polyploidization can precede the development of aneuploidy in cancer. Polyploidization in megakaryocytes (Mks), in contrast, is a highly controlled developmental process critical for efficient platelet production via unknown mechanisms. Using primary cells, we demonstrate that the guanine exchange factors GEF-H1 and ECT2, which are often overexpressed in cancer and are essential for RhoA activation during cytokinesis, must be downregulated for Mk polyploidization. The first (2N-4N) endomitotic cycle requires GEF-H1 downregulation, whereas subsequent cycles (>4N) require ECT2 downregulation. Exogenous expression of both GEF-H1 and ECT2 prevents endomitosis, resulting in proliferation of 2N Mks. Furthermore, we have shown that the mechanism by which polyploidization is prevented in Mks lacking Mkl1, which is mutated in megakaryocytic leukemia, is via elevated GEF-H1 expression; shRNA-mediated GEF-H1 knockdown alone rescues this ploidy defect. These mechanistic insights enhance our understanding of normal versus malignant megakaryocytopoiesis, as well as aberrant mitosis in aneuploid cancers.
Role of RhoA-specific guanine exchange factors in regulation of endomitosis in megakaryocytes.
33118292
WHAT IS KNOWN AND OBJECTIVE There is a growing body of experimental and clinical evidence for the atherogenic and pro-thrombotic potential of Lipoprotein(a) [Lp(a)], as well as for its causative role in coronary heart disease and stroke. We comment on novel strategies for reducing Lp(a) levels. COMMENT Irrespective of the underlying biological mechanisms explaining the athero-thrombotic potential of this lipoprotein, most work has focused on the identification of suitable therapies for hyperlipoproteinemia(a). These include apheresis techniques, nicotinic acid and statins. None of these strategies have been shown to be definitely effective or convenient for the patient and new strategies are being attempted. Promising results are emerging with therapeutic interventions targeting the 'inflammatory pathways' by inhibition of Interleukin-6 (IL-6) signalling with natural compounds (e.g., Ginko biloba) or the IL-6 receptor antibody Tocilizumab. These may both lower Lp(a) and cardiovascular risk of the patients. Besides inhibiting platelet function, antiplatelet therapy with aspirin may also decrease the plasma concentration of Lp(a) and modulate its influence on platelets. WHAT IS NEW AND CONCLUSION We highlight the inadequacy of current approaches for lowering Lp(a) and draw attention to novel insights that may lead to better treatment.
Optimal therapy for reduction of lipoprotein(a).
33127778
Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.
Early gastric cancer and dysplasia.
33135135
This article reviews and critiques community-based research on the effects of homelessness on children. Homeless children confront serious threats to their ability to succeed and their future well-being. Of particular concern are health problems, hunger, poor nutrition, developmental delays, anxiety, depression, behavioral problems, and educational underachievement. Factors that may mediate the observed outcomes include inadequate shelter conditions, instability in residences and shelters, inadequate services, and barriers to accessing services that are available. Public policy initiatives are needed to meet the needs of homeless children.
The impact of homelessness on children.
33169058
The potential benefits of cooperation in microorganisms can be undermined by genetic conflict within social groups, which can take the form of 'cheating'. For cooperation to succeed as an evolutionary strategy, the negative effects of such conflict must somehow be either prevented or mitigated. To generate an interpretive framework for future research in microbial behavioural ecology, here we outline a wide range of hypothetical mechanisms by which cheaters might be constrained.
Strategies of microbial cheater control.
33203108
INTRODUCTION Paraquat is a commonly ingested poison especially in Southern India. There is no antidote for paraquat poison and consumption is often fatal. The usual cause of death is either acute lung injury or multi-organ failure. AIM To evaluate the role of early haemoperfusion as a therapy in paraquat poisoned patients. MATERIALS AND METHODS This study was a retrospective analysis of patients admitted to a Tertiary Medical College Hospital between January 2012 and December 2015 with history of paraquat consumption, comparing outcomes in those who received only gastric lavage and symptomatic treatment with those who received haemoperfusion as a therapy. The role of early haemoperfusion (≤ 6 hours) vs late haemoperfusion (> 6 hours) in paraquat poisoned patients was also compared. The data of these patients was extracted and analysed with respect to age, sex, mode of treatment, the outcome in patients who received early and late haemoperfusion. RESULTS A total of 101 patients were studied out of which 62 died. Deaths were more in those patients who received only gastric lavage with symptomatic treatment as therapy compared to those who received haemoperfusion i.e., 92.1% vs 42.9% respectively. We also found that, the survival rate was better in patients who received early haemoperfusion. CONCLUSION Early haemoperfusion was helpful in the management of severe paraquat poisoning and improved the survival rate in these patients.
Golden Hours in Severe Paraquat Poisoning-The Role of Early Haemoperfusion Therapy.
33257464
CONTEXT Although cerebral palsy (CP) among extremely premature infants has been reported as a major morbidity outcome, there are difficulties comparing published CP rates from many sites over various birth years. OBJECTIVE To assess the changes in population-based, gestational age-specific prevalence rates of CP among extremely premature infants over 30 years. DESIGN Prospective population-based longitudinal outcome study. SETTING AND PARTICIPANTS In Northern Alberta, 2318 infants 20 to 27 weeks' gestational age with birth weights of 500 to 1249 g were liveborn from 1974 through 2003. By 2 years of age, 1437 (62%) had died, 23 (1%) were lost to follow-up, and 858 (37%) had received multidisciplinary neurodevelopmental assessment. MAIN OUTCOME MEASURE Population-based prevalence rates of CP were determined. Logistic regression with linear spline was used to assess changes in CP prevalence over time. RESULTS At age 2 years, 122 (14.2%) of 858 survivors had CP. This diagnosis was confirmed for each child by age 3 years or older. Among those whose gestational age was 20 to 25 weeks, population-based survival increased from 4% to 31% (P<.001), while CP prevalence per 1000 live births increased monotonically from 0 to 110 until the years 1992-1994 (P<.001) and decreased thereafter to 22 in the years 2001-2003 (P<.001). Among those whose gestational age was 26 to 27 weeks, population-based survival increased from 23% to between 75% and 80% (P<.001), while CP prevalence per 1000 live births increased monotonically from 15 to 155 until the years 1992-1994 (P<.001) and then decreased to 16 in the years 2001-2003 (P<.001). For all survivors born in the years 2001-2003, CP prevalence was 19 per 1000 live births. CONCLUSION Population-based CP prevalence rates for children whose gestational age was 20 to 27 weeks and whose birth weight ranged from 500 to 1249 g show steady reductions in the last decade with stable or reducing mortality, reversing trends prior to 1992-1994.
Changes in the prevalence of cerebral palsy for children born very prematurely within a population-based program over 30 years.
33339202
Porphyria cutanea tarda (PCT) can occur in HIV patients. Current evidence suggests that HIV infection may interfere with the hepatic cytochrome oxidase system, leading to porphyrin metabolism impairment. Moreover, chronic hemodialysis in renal failure may be a risk factor for PCT. In addition to the contributory factors for PCT associated to HIV infection, it is possible that porphyrin accumulation secondary to renal failure may play a role in the expression of this disease. We report a case of PCT in an HIV-1 infected patient under blood dialysis, refractory to antimalarials and controlled with desferrioxamine.
Desferrioxamine treatment of porphyria cutanea tarda in a patient with HIV and chronic renal failure.
33387953
Activating mutations in genes encoding G protein α (Gα) subunits occur in 4-5% of all human cancers, but oncogenic alterations in Gβ subunits have not been defined. Here we demonstrate that recurrent mutations in the Gβ proteins GNB1 and GNB2 confer cytokine-independent growth and activate canonical G protein signaling. Multiple mutations in GNB1 affect the protein interface that binds Gα subunits as well as downstream effectors and disrupt Gα interactions with the Gβγ dimer. Different mutations in Gβ proteins clustered partly on the basis of lineage; for example, all 11 GNB1 K57 mutations were in myeloid neoplasms, and seven of eight GNB1 I80 mutations were in B cell neoplasms. Expression of patient-derived GNB1 variants in Cdkn2a-deficient mouse bone marrow followed by transplantation resulted in either myeloid or B cell malignancies. In vivo treatment with the dual PI3K-mTOR inhibitor BEZ235 suppressed GNB1-induced signaling and markedly increased survival. In several human tumors, mutations in the gene encoding GNB1 co-occurred with oncogenic kinase alterations, including the BCR-ABL fusion protein, the V617F substitution in JAK2 and the V600K substitution in BRAF. Coexpression of patient-derived GNB1 variants with these mutant kinases resulted in inhibitor resistance in each context. Thus, GNB1 and GNB2 alterations confer transformed and resistance phenotypes across a range of human tumors and may be targetable with inhibitors of G protein signaling.
Mutations in G protein beta subunits promote transformation and kinase inhibitor resistance
33390472
We have developed a novel panel of cell-surface markers for the isolation and study of all major cell types of the human pancreas. Hybridomas were selected after subtractive immunization of Balb/C mice with intact or dissociated human islets and assessed for cell-type specificity and cell-surface reactivity by immunohistochemistry and flow cytometry. Antibodies were identified by specific binding of surface antigens on islet (panendocrine or alpha-specific) and nonislet pancreatic cell subsets (exocrine and duct). These antibodies were used individually or in combination to isolate populations of alpha, beta, exocrine, or duct cells from primary human pancreas by FACS and to characterize the detailed cell composition of human islet preparations. They were also employed to show that human islet expansion cultures originated from nonendocrine cells and that insulin expression levels could be increased to up to 1% of normal islet cells by subpopulation sorting and overexpression of the transcription factors Pdx-1 and ngn3, an improvement over previous results with this culture system. These methods permit the analysis and isolation of functionally distinct pancreatic cell populations with potential for cell therapy.
Isolation of major pancreatic cell types and long-term culture-initiating cells using novel human surface markers.
33397197
Modest clinical outcomes of dendritic-cell (DC) vaccine trials call for the refinement of DC vaccine design. Although many potential antigens have been identified, development of methods to enhance antigen presentation by DCs has lagged. We have engineered a potent, drug-inducible CD40 (iCD40) receptor that permits temporally controlled, lymphoid-localized, DC-specific activation. iCD40 is comprised of a membrane-localized cytoplasmic domain of CD40 fused to drug-binding domains. This allows it to respond to a lipid-permeable, high-affinity dimerizer drug while circumventing ectodomain-dependent negative-feedback mechanisms. These modifications permit prolonged activation of iCD40-expressing DCs in vivo, resulting in more potent CD8+ T-cell effector responses, including the eradication of previously established solid tumors, relative to activation of DCs ex vivo (P < 0.01), typical of most clinical DC protocols. In addition, iCD40-mediated DC activation exceeded that achieved by stimulating the full-length, endogenous CD40 receptor both in vitro and in vivo. Because iCD40 is insulated from the extracellular environment and can be activated within the context of an immunological synapse, iCD40-expressing DCs have a prolonged lifespan and should lead to more potent vaccines, perhaps even in immune-compromised patients.
Re-engineered CD40 receptor enables potent pharmacological activation of dendritic-cell cancer vaccines in vivo
33409100
CONTEXT High plasma homocysteine levels are a risk factor for mortality and vascular disease in observational studies of patients with chronic kidney disease. Folic acid and B vitamins decrease homocysteine levels in this population but whether they lower mortality is unknown. OBJECTIVE To determine whether high doses of folic acid and B vitamins administered daily reduce mortality in patients with chronic kidney disease. DESIGN, SETTING, AND PARTICIPANTS Double-blind randomized controlled trial (2001-2006) in 36 US Department of Veterans Affairs medical centers. Median follow-up was 3.2 years for 2056 participants aged 21 years or older with advanced chronic kidney disease (estimated creatinine clearance < or =30 mL/min) (n = 1305) or end-stage renal disease (n = 751) and high homocysteine levels (> or = 15 micromol/L). INTERVENTION Participants received a daily capsule containing 40 mg of folic acid, 100 mg of pyridoxine hydrochloride (vitamin B6), and 2 mg of cyanocobalamin (vitamin B12) or a placebo. MAIN OUTCOME MEASURES The primary outcome was all-cause mortality. Secondary outcomes included myocardial infarction (MI), stroke, amputation of all or part of a lower extremity, a composite of these 3 plus all-cause mortality, time to initiation of dialysis, and time to thrombosis of arteriovenous access in hemodialysis patients. RESULTS Mean baseline homocysteine level was 24.0 micromol/L in the vitamin group and 24.2 micromol/L in the placebo group. It was lowered 6.3 micromol/L (25.8%; P < .001) in the vitamin group and 0.4 micromol/L (1.7%; P = .14) in the placebo group at 3 months, but there was no significant effect on mortality (448 vitamin group deaths vs 436 placebo group deaths) (hazard ratio [HR], 1.04; 95% CI, 0.91-1.18). No significant effects were demonstrated for secondary outcomes or adverse events: there were 129 MIs in the vitamin group vs 150 for placebo (HR, 0.86; 95% CI, 0.67-1.08), 37 strokes in the vitamin group vs 41 for placebo (HR, 0.90; 95% CI, 0.58-1.40), and 60 amputations in the vitamin group vs 53 for placebo (HR, 1.14; 95% CI, 0.79-1.64). In addition, the composite of MI, stroke, and amputations plus mortality (P = .85), time to dialysis (P = .38), and time to thrombosis in hemodialysis patients (P = .97) did not differ between the vitamin and placebo groups. CONCLUSION Treatment with high doses of folic acid and B vitamins did not improve survival or reduce the incidence of vascular disease in patients with advanced chronic kidney disease or end-stage renal disease. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00032435.
Effect of homocysteine lowering on mortality and vascular disease in advanced chronic kidney disease and end-stage renal disease: a randomized controlled trial.
33417012
OBJECTIVE This study compared, in treatment and control groups, the phenomena of coaction, which is the probability that taking effective action on one behavior is related to taking effective action on a second behavior. METHODS Pooled data from three randomized trials of Transtheoretical Model (TTM) tailored interventions (n=9461), completed in the U.S. in 1999, were analyzed to assess coaction in three behavior pairs (diet and sun protection, diet and smoking, and sun protection and smoking). Odds ratios (ORs) compared the likelihood of taking action on a second behavior compared to taking action on only one behavior. RESULTS Across behavior pairs, at 12 and 24 months, the ORs for the treatment group were greater on an absolute basis than for the control group, with two being significant. The combined ORs at 12 and 24 months, respectively, were 1.63 and 1.85 for treatment and 1.20 and 1.10 for control. CONCLUSIONS The results of this study with addictive, energy balance and appearance-related behaviors were consistent with results found in three studies applying TTM tailoring to energy balance behaviors. Across studies, there was more coaction within the treatment group. Future research should identify predictors of coaction in more multiple behavior change interventions.
Treated individuals who progress to action or maintenance for one behavior are more likely to make similar progress on another behavior: coaction results of a pooled data analysis of three trials.
33458992
CONTEXT Trabecular bone score (TBS) is a novel texture index that evaluates the pixel gray-level variations in lumbar spine dual-energy X-ray absorptiometry images and is related to bone microarchitecture independent of bone mineral density (BMD). OBJECTIVE We investigated lumbar spine TBS as an indicator for skeletal deterioration in diabetes. DESIGN AND SETTING Cross-sectional data were collected from subjects participating in an ongoing prospective, community-based, cohort study from 2009 to 2010. PARTICIPANTS We included 1229 men and 1529 postmenopausal women older than 50 years in the Ansung cohort. OUTCOME MEASURES Biochemical parameters, lumbar spine TBS, and BMD from dual-energy X-ray absorptiometry images were measured. RESULTS Lumbar spine TBS was lower in men with diabetes than in nondiabetic men (1.287 ± 0.005 vs 1.316 ± 0.003, P < .001), whereas lumbar spine BMD was higher in men with diabetes (1.135 ± 0.010 vs 1.088 ± 0.006 g/cm(2)). Lumbar spine TBS was lower in women with diabetes than in nondiabetic women only in an unadjusted model (1.333 ± 0.004 vs 1.353 ± 0.003). However, women younger than 65 years (n = 707) with diabetes had a lower TBS than those without diabetes, even after adjusted for covariates (P < .001). Diabetes was not associated with BMD at femur sites in both genders. TBS was negatively correlated with glycated hemoglobin, fasting plasma glucose, fasting insulin, and homeostasis model assessment for insulin resistance but not with homeostasis model assessment for β-cell function in both genders. CONCLUSIONS The inverse association between lumbar spine TBS and insulin resistance may make it an indicator for determining skeletal deterioration in diabetic patients who have high BMD.
Trabecular bone score as an indicator for skeletal deterioration in diabetes.
33499189
T cell receptor (TCR-CD3) triggering involves both receptor clustering and conformational changes at the cytoplasmic tails of the CD3 subunits. The mechanism by which TCRalphabeta ligand binding confers conformational changes to CD3 is unknown. By using well-defined ligands, we showed that induction of the conformational change requires both multivalent engagement and the mobility restriction of the TCR-CD3 imposed by the plasma membrane. The conformational change is elicited by cooperative rearrangements of two TCR-CD3 complexes and does not require accompanying changes in the structure of the TCRalphabeta ectodomains. This conformational change at CD3 reverts upon ligand dissociation and is required for T cell activation. Thus, our permissive geometry model provides a molecular mechanism that rationalizes how the information of ligand binding to TCRalphabeta is transmitted to the CD3 subunits and to the intracellular signaling machinery.
Full activation of the T cell receptor requires both clustering and conformational changes at CD3.
33507866
A critical regulator of autophagy is the Class III PI3K Vps34 (also called PIK3C3). Although Vps34 is known to play an essential role in autophagy in yeast, its role in mammals remains elusive. To elucidate the physiological function of Vps34 and to determine its precise role in autophagy, we have generated Vps34(f/f) mice, in which expression of Cre recombinase results in a deletion of exon 4 of Vps34 and a frame shift causing a deletion of 755 of the 887 amino acids of Vps34. Acute ablation of Vps34 in MEFs upon adenoviral Cre infection results in a diminishment of localized generation of phosphatidylinositol 3-phosphate and blockade of both endocytic and autophagic degradation. Starvation-induced autophagosome formation is blocked in both Vps34-null MEFs and liver. Liver-specific Albumin-Cre;Vps34(f/f) mice developed hepatomegaly and hepatic steatosis, and impaired protein turnover. Ablation of Vps34 in the heart of muscle creatine kinase-Cre;Vps34(f/f) mice led to cardiomegaly and decreased contractility. In addition, while amino acid-stimulated mTOR activation was suppressed in the absence of Vps34, the steady-state level of mTOR signaling was not affected in Vps34-null MEFs, liver, or cardiomyocytes. Taken together, our results indicate that Vps34 plays an essential role in regulating functional autophagy and is indispensable for normal liver and heart function.
Class III PI3K Vps34 plays an essential role in autophagy and in heart and liver function.
33533307
BACKGROUND The Digitalis Investigation Group trial reported that treatment with digoxin did not decrease overall mortality among patients with heart failure and depressed left ventricular systolic function, although it did reduce hospitalizations slightly. Even though the epidemiologic features, causes, and prognosis of heart failure vary between men and women, sex-based differences in the effect of digoxin were not evaluated. METHODS We conducted a post hoc subgroup analysis to assess whether there were sex-based differences in the effect of digoxin therapy among the 6800 patients in the Digitalis Investigation Group study. The presence of an interaction between sex and digoxin therapy with respect to the primary end point of death from any cause was evaluated with the use of Mantel-Haenszel tests of heterogeneity and a multivariable Cox proportional-hazards model, adjusted for demographic and clinical variables. RESULTS There was an absolute difference of 5.8 percent (95 percent confidence interval, 0.5 to 11.1) between men and women in the effect of digoxin on the rate of death from any cause (P=0.034 for the interaction). Specifically, women who were randomly assigned to digoxin had a higher rate of death than women who were randomly assigned to placebo (33.1 percent vs. 28.9 percent; absolute difference, 4.2 percent, 95 percent confidence interval, -0.5 to 8.8). In contrast, the rate of death was similar among men randomly assigned to digoxin and men randomly assigned to placebo (35.2 percent vs. 36.9 percent; absolute difference, -1.6 percent; 95 percent confidence interval, -4.2 to 1.0). In the multivariable analysis, digoxin was associated with a significantly higher risk of death among women (adjusted hazard ratio for the comparison with placebo, 1.23; 95 percent confidence interval, 1.02 to 1.47), but it had no significant effect among men (adjusted hazard ratio, 0.93; 95 percent confidence interval, 0.85 to 1.02; P=0.014 for the interaction). CONCLUSIONS The effect of digoxin therapy differs between men and women. Digoxin therapy is associated with an increased risk of death from any cause among women, but not men, with heart failure and depressed left ventricular systolic function.
Sex-based differences in the effect of digoxin for the treatment of heart failure.
33535222
CD4+CD25+ regulatory T cells (Treg's) play a pivotal role in preventing organ-specific autoimmune diseases and in inducing tolerance to allogeneic organ transplants. We and others recently demonstrated that high numbers of Treg's can also modulate graft-versus-host disease (GVHD) if administered in conjunction with allogeneic hematopoietic stem cell transplantation in mice. In a clinical setting, it would be impossible to obtain enough freshly purified Treg's from a single donor to have a therapeutic effect. Thus, we performed regulatory T cell expansion ex vivo by stimulation with allogeneic APCs, which has the additional effect of producing alloantigen-specific regulatory T cells. Here we show that regulatory T cells specific for recipient-type alloantigens control GVHD while favoring immune reconstitution. Irrelevant regulatory T cells only mediate a partial protection from GVHD. Preferential survival of specific regulatory T cells, but not of irrelevant regulatory T cells, was observed in grafted animals. Additionally, the use of specific regulatory T cells was compatible with some form of graft-versus-tumor activity. These data suggest that recipient-type specific Treg's could be preferentially used in the control of GVHD in future clinical trials.
Recipient-type specific CD4+CD25+ regulatory T cells favor immune reconstitution and control graft-versus-host disease while maintaining graft-versus-leukemia.
33535447
This study evaluates the expression of the chemorepellent semaphorin III (D)/collapsin-1 (sema III) following lesions to the rat CNS. Scar tissue, formed after penetrating injuries to the lateral olfactory tract (LOT), cortex, perforant pathway, and spinal cord, contained numerous spindle-shaped cells expressing high levels of sema III mRNA. The properties of these cells were investigated in detail in the lesioned LOT. Most sema III mRNA-positive cells were located in the core of the scar and expressed proteins characteristic for fibroblast-like cells. Neuropilin-1, a sema III receptor, was expressed in injured neurons with projections to the lesion site, in a subpopulation of scar-associated cells and in blood vessels around the scar. In contrast to lesions made in the mature CNS, LOT transection in neonates did not induce sema III mRNA expression within cells in the lesion and was followed by vigorous axonal regeneration. The concomitant expression of sema III and its receptor neuropilin-1 in the scar suggests that sema III/neuropilin-1-mediated mechanisms are involved in CNS scar formation. The expression of the secreted chemorepellent sema III following CNS injury provides the first evidence that chemorepulsive semaphorins may contribute to the inhibitory effects exerted by scars on the outgrowth of injured CNS neurites. The vigorous regrowth of injured axons in the absence of sema III following early neonatal lesions is consistent with this notion. The inactivation of sema III in scar tissue by either antibody perturbation or by genetic or pharmacological intervention could be a powerful means to promote long-distance regeneration in the adult CNS.
Expression of the gene encoding the chemorepellent semaphorin III is induced in the fibroblast component of neural scar tissue formed following injuries of adult but not neonatal CNS.
33554389
Abstract The effect of increased levels of cAMP upon the differentiation of primary cultures of chick myo blasts has been investigated. 0.1 mM But 2 cAMP or 1 mM 3-isobutyl-1-methylxanthine was added to the cultures 24 h after plating and maintained throughout the 70 h period of culture examined. Both reagents were found to markedly delay the time of fusion of the myoblasts but had no observable effect upon the increase in activity of creatine phosphokinase. Morphological examination of the cells revealed no difference in the relative numbers of myoblasts and fibroblasts between the control, But 2 cAMP and 3-isobutyl-1-methylxanthine cultures, but the latter reagent appeared to cause some inhibition of cell proliferation.
The relationship of the level of cyclic amp to differentiation in primary cultures of chick muscle cells.
33569870
The physiological role of autophagic flux within the vascular endothelial layer remains poorly understood. Here, we show that in primary endothelial cells, oxidized and native LDL stimulates autophagosome formation. Moreover, by both confocal and electron microscopy, excess native or modified LDL appears to be engulfed within autophagic structures. Transient knockdown of the essential autophagy gene ATG7 resulted in higher levels of intracellular (125) I-LDL and oxidized LDL (OxLDL) accumulation, suggesting that in endothelial cells, autophagy may represent an important mechanism to regulate excess, exogenous lipids. The physiological importance of these observations was assessed using mice containing a conditional deletion of ATG7 within the endothelium. Following acute intravenous infusion of fluorescently labeled OxLDL, mice lacking endothelial expression of ATG7 demonstrated prolonged retention of OxLDL within the retinal pigment epithelium (RPE) and choroidal endothelium of the eye. In a chronic model of lipid excess, we analyzed atherosclerotic burden in ApoE(-/-) mice with or without endothelial autophagic flux. The absence of endothelial autophagy markedly increased atherosclerotic burden. Thus, in both an acute and chronic in vivo model, endothelial autophagy appears critically important in limiting lipid accumulation within the vessel wall. As such, strategies that stimulate autophagy, or prevent the age-dependent decline in autophagic flux, might be particularly beneficial in treating atherosclerotic vascular disease.
Intact endothelial autophagy is required to maintain vascular lipid homeostasis.
33634749
OBJECTIVE Genes encoding the circadian transcriptional apparatus exhibit robust oscillatory expression in murine adipose tissues. This study tests the hypothesis that human subcutaneous adipose-derived stem cells (ASCs) provide an in vitro model in which to monitor the activity of the core circadian transcriptional apparatus. RESEARCH METHODS AND PROCEDURES Primary cultures of undifferentiated or adipocyte-differentiated ASCs were treated with dexamethasone, rosiglitazone, or 30% fetal bovine serum. The response of undifferentiated ASCs to dexamethasone was further evaluated in the presence of lithium chloride. Lithium inhibits glycogen synthase kinase 3, a key component of the circadian apparatus. Total RNA was harvested at 4-hour intervals over 48 hours and examined by real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS Adipocyte-differentiated cells responded more rapidly to treatments than their donor-matched undifferentiated controls; however, the period of the circadian gene oscillation was longer in the adipocyte-differentiated cells. Dexamethasone generated circadian gene expression patterns with mean periods of 25.4 and 26.7 hours in undifferentiated and adipocyte-differentiated ASCs, respectively. Both rosiglitazone and serum shock generated a significantly longer period in adipocyte-differentiated ASCs relative to undifferentiated ASCs. The Bmal1 profile was phase-shifted by approximately 8 to 12 hours relative to Per1, Per3, and Cry2, consistent with their expression in vivo. Lithium chloride inhibited adipogenesis and significantly lengthened the period of Per3 and Rev-erbalpha gene expression profiles by >5 hours in dexamethasone-activated undifferentiated ASCs. DISCUSSION These results support the initial hypothesis and validate ASCs as an in vitro model for the analysis of circadian biology in human adipose tissue.
Induction of circadian gene expression in human subcutaneous adipose-derived stem cells.
33638477
Several components of the Wnt signaling cascade have been shown to function either as tumor suppressor proteins or as oncogenes in multiple human cancers, underscoring the relevance of this pathway in oncogenesis and the need for further investigation of Wnt signaling components as potential targets for cancer therapy. Here, using expression profiling analysis as well as in vitro and in vivo functional studies, we show that the Wnt pathway component BCL9 is a novel oncogene that is aberrantly expressed in human multiple myeloma as well as colon carcinoma. We show that BCL9 enhances beta-catenin-mediated transcriptional activity regardless of the mutational status of the Wnt signaling components and increases cell proliferation, migration, invasion, and the metastatic potential of tumor cells by promoting loss of epithelial and gain of mesenchymal-like phenotype. Most importantly, BCL9 knockdown significantly increased the survival of xenograft mouse models of cancer by reducing tumor load, metastasis, and host angiogenesis through down-regulation of c-Myc, cyclin D1, CD44, and vascular endothelial growth factor expression by tumor cells. Together, these findings suggest that deregulation of BCL9 is an important contributing factor to tumor progression. The pleiotropic roles of BCL9 reported in this study underscore its value as a drug target for therapeutic intervention in several malignancies associated with aberrant Wnt signaling.
BCL9 promotes tumor progression by conferring enhanced proliferative, metastatic, and angiogenic properties to cancer cells.
33667484
Programmed cell death (PCD), referring to apoptosis, autophagy and programmed necrosis, is proposed to be death of a cell in any pathological format, when mediated by an intracellular program. These three forms of PCD may jointly decide the fate of cells of malignant neoplasms; apoptosis and programmed necrosis invariably contribute to cell death, whereas autophagy can play either pro-survival or pro-death roles. Recent bulk of accumulating evidence has contributed to a wealth of knowledge facilitating better understanding of cancer initiation and progression with the three distinctive types of cell death. To be able to decipher PCD signalling pathways may aid development of new targeted anti-cancer therapeutic strategies. Thus in this review, we present a brief outline of apoptosis, autophagy and programmed necrosis pathways and apoptosis-related microRNA regulation, in cancer. Taken together, understanding PCD and the complex interplay between apoptosis, autophagy and programmed necrosis may ultimately allow scientists and clinicians to harness the three types of PCD for discovery of further novel drug targets, in the future cancer treatment.
Programmed cell death pathways in cancer: a review of apoptosis, autophagy and programmed necrosis.
33669399
Gametophytic self-incompatibility (SI) in plants is a widespread mechanism preventing self-fertilization and the ensuing inbreeding depression, but it often evolves to self-compatibility. We analyze genetic mechanisms for the breakdown of gametophytic SI, incorporating a dynamic model for the evolution of inbreeding depression allowing for partial purging of nearly recessive lethal mutations by selfing, and accounting for pollen limitation and sheltered load linked to the S-locus. We consider two mechanisms for the breakdown of gametophytic SI: a nonfunctional S-allele and an unlinked modifier locus that inactivates the S-locus. We show that, under a wide range of conditions, self-compatible alleles can invade a self-incompatible population. Conditions for invasion are always less stringent for a nonfunctional S-allele than for a modifier locus. The spread of self-compatible genotypes is favored by extremely high or low selfing rates, a small number of S-alleles, and pollen limitation. Observed parameter values suggest that the maintenance of gametophytic SI is caused by a combination of high inbreeding depression in self-incompatible populations coupled with intermediate selfing rates of the self-compatible genotypes and sheltered load linked to the S-locus.
Loss of gametophytic self-incompatibility with evolution of inbreeding depression.
33677323
MicroRNAs are frequently deregulated in cancer. Here we show that miR-22 is upregulated in myelodysplastic syndrome (MDS) and leukemia and its aberrant expression correlates with poor survival. To explore its role in hematopoietic stem cell function and malignancy, we generated transgenic mice conditionally expressing miR-22 in the hematopoietic compartment. These mice displayed reduced levels of global 5-hydroxymethylcytosine (5-hmC) and increased hematopoietic stem cell self-renewal accompanied by defective differentiation. Conversely, miR-22 inhibition blocked proliferation in both mouse and human leukemic cells. Over time, miR-22 transgenic mice developed MDS and hematological malignancies. We also identify TET2 as a key target of miR-22 in this context. Ectopic expression of TET2 suppressed the miR-22-induced phenotypes. Downregulation of TET2 protein also correlated with poor clinical outcomes and miR-22 overexpression in MDS patients. Our results therefore identify miR-22 as a potent proto-oncogene and suggest that aberrations in the miR-22/TET2 regulatory network are common in hematopoietic malignancies.
The oncogenic microRNA miR-22 targets the TET2 tumor suppressor to promote hematopoietic stem cell self-renewal and transformation.
33684572
Recent studies indicate both clinical and mechanistic links between atherosclerotic heart disease and intestinal microbial metabolism of certain dietary nutrients producing trimethylamine N-oxide (TMAO). Here we test the hypothesis that gut microbial transplantation can transmit choline diet-induced TMAO production and atherosclerosis susceptibility. First, a strong association was noted between atherosclerotic plaque and plasma TMAO levels in a mouse diversity panel (n = 22 strains, r = 0.38; p = 0.0001). An atherosclerosis-prone and high TMAO-producing strain, C57BL/6J, and an atherosclerosis-resistant and low TMAO-producing strain, NZW/LacJ, were selected as donors for cecal microbial transplantation into apolipoprotein e null mice in which resident intestinal microbes were first suppressed with antibiotics. Trimethylamine (TMA) and TMAO levels were initially higher in recipients on choline diet that received cecal microbes from C57BL/6J inbred mice; however, durability of choline diet-dependent differences in TMA/TMAO levels was not maintained to the end of the study. Mice receiving C57BL/6J cecal microbes demonstrated choline diet-dependent enhancement in atherosclerotic plaque burden as compared with recipients of NZW/LacJ microbes. Microbial DNA analyses in feces and cecum revealed transplantation of donor microbial community features into recipients with differences in taxa proportions between donor strains that were transmissible to recipients and that tended to show coincident proportions with TMAO levels. Proportions of specific taxa were also identified that correlated with plasma TMAO levels in donors and recipients and with atherosclerotic lesion area in recipients. Atherosclerosis susceptibility may be transmitted via transplantation of gut microbiota. Gut microbes may thus represent a novel therapeutic target for modulating atherosclerosis susceptibility.
Transmission of atherosclerosis susceptibility with gut microbial transplantation.
33720691
AWN is a boar protein which originates in secretions of the male accessory glands and which becomes sperm surface-associated upon ejaculation. It is one of the components thought to mediate sperm adhesion to the egg's zona pellucida through a carbohydrate-recognition mechanism. AWN may, thus, participate in the initial events of fertilization in the pig. In this report we describe its complete primary structure by combination of protein-chemical and mass spectrometric methods. AWN exists as two isoforms, AWN-1 and AWN-2, which differ in that AWN-2 is N-terminally acetylated. The amino acid sequence of AWN contains 133 amino acid residues and two disulphide bridges between nearest-neighbour cysteine residues. Analysis of the amino acid sequence of the AWN proteins showed significant similarity only to AQN-1 and AQN-3, two other boar spermadhesins.
The complete primary structure of the spermadhesin AWN, a zona pellucida-binding protein isolated from boar spermatozoa.
33723822
This paper proposes a framework for examining the process by which government consideration and adoption of new vaccines takes place, with specific reference to developing country settings. The cases of early Hepatitis B vaccine adoption in Taiwan and Thailand are used to explore the relevance of explanatory factors identified in the literature as well as the need to go beyond a variable-centric focus by highlighting the role of policy context and process in determining the pace and extent of adoption. The cases suggest the feasibility and importance of modeling 'causal diversity'-the complex set of necessary and sufficient conditions leading to particular decisional outcomes-in a broad range of country contexts. A better understanding of the lenses through which government decision-makers filter information, and of the arenas in which critical decisions are shaped and taken, may assist both analysts (in predicting institutionalization of new vaccines) and advocates (in crafting targeted strategies to accelerate their diffusion).
What influences government adoption of vaccines in developing countries? A policy process analysis.
33733520
BACKGROUND Benzodiazepines are frequently used medications in the elderly, in whom they are associated with an increased risk of falling, with sometimes dire consequences. OBJECTIVE To estimate the impact of benzodiazepine-associated injurious falls in a population of elderly persons. METHOD A nested case-control study was conducted using data collected during 10 years of follow-up of the French PAQUID (Personnes Agées QUID) community-based cohort. The main outcome measure was the occurrence of an injurious fall, which was defined as a fall resulting in hospitalization, fracture, head trauma or death. Controls (3 : 1) were frequency-matched to cases. Benzodiazepine exposure was the use of benzodiazepines over the previous 2 weeks reported at the follow-up visit preceding the fall. RESULTS Benzodiazepine use was significantly associated with the occurrence of injurious falls, with a significant interaction with age. The adjusted odds ratio for injurious falls in subjects exposed to benzodiazepines was 2.2 (95% CI 1.4, 3.4) in subjects aged > or = 80 years and 1.3 (95% CI 0.9, 1.9) in subjects aged <80 years. The population attributable risk for injurious falls in subjects exposed to benzodiazepines was 28.1% (95% CI 16.7, 43.2) for subjects aged > or =80 years. The incidence of injurious falls in subjects aged > or = 80 years exposed to benzodiazepines in the PAQUID cohort was 2.8/100 person-years. Over 9% of these falls were fatal. According to these results and to recent population estimates, benzodiazepine use could be held responsible for almost 20 000 injurious falls in subjects aged > or = 80 years every year in France, and for nearly 1800 deaths. CONCLUSION Given the considerable morbidity and mortality associated with benzodiazepine use and the fact that existing good practice guidelines on benzodiazepines have not been effective in preventing their misuse (possibly because they have not been applied), new methods for limiting use of benzodiazepines in the elderly need to be found.
Benzodiazepines and injurious falls in community dwelling elders.
33740844
Current understanding of biologic processes indicates that women's nutritional status before and during early pregnancy may play an important role in determining early developmental processes and ensuring successful pregnancy outcomes. We conducted a systematic review of the evidence for the impact of maternal nutrition before and during early pregnancy (<12 weeks gestation) on maternal, neonatal and child health outcomes and included 45 articles (nine intervention trials and 32 observational studies) that were identified through PubMed and EMBASE database searches and examining review articles. Intervention trials and observational studies show that periconceptional (<12 weeks gestation) folic acid supplementation significantly reduced the risk of neural tube defects. Observational studies suggest that preconceptional and periconceptional intake of vitamin and mineral supplements is associated with a reduced risk of delivering offspring who are low birthweight and/or small-for-gestational age (SGA) and preterm deliveries (PTD). Some studies report that indicators of maternal prepregnancy size, low stature, underweight and overweight are associated with increased risks of PTD and SGA. The available data indicate the importance of women's nutrition prior to and during the first trimester of pregnancy, but there is a need for well-designed prospective studies and controlled trials in developing country settings that examine relationships with low birthweight, SGA, PTD, stillbirth and maternal and neonatal mortality. The knowledge gaps that need to be addressed include the evaluation of periconceptional interventions such as food supplements, multivitamin-mineral supplements and/or specific micronutrients (iron, zinc, iodine, vitamin B-6 and B-12) as well as the relationship between measures of prepregnancy body size and composition and maternal, neonatal and child health outcomes.
Effect of women's nutrition before and during early pregnancy on maternal and infant outcomes: a systematic review.
33792330
Hedgehog signaling plays an essential role in patterning of the vertebrate skeleton. Here we demonstrate that conditional inactivation of the Kif3a subunit of the kinesin-2 intraflagellar transport motor in mesenchymal skeletal progenitor cells results in severe patterning defects in the craniofacial area, the formation of split sternum and the development of polydactyly. These deformities are reminiscent of those previously described in mice with deregulated hedgehog signaling. We show that in Kif3a-deficient mesenchymal tissues both the repressor function of Gli3 transcription factor and the activation of the Shh transcriptional targets Ptch and Gli1 are compromised. Quantitative analysis of gene expression demonstrates that the Gli1 transcript level is dramatically reduced, whereas Gli3 expression is not significantly affected by kinesin-2 depletion. However, the motor appears to be required for the efficient cleavage of the full-length Gli3 transcription factor into a repressor form.
Kinesin-2 controls development and patterning of the vertebrate skeleton by Hedgehog- and Gli3-dependent mechanisms.
33796570
Neurofibromatosis type 1 (NF1) is a prevalent genetic disorder that affects growth properties of neural-crest-derived cell populations. In addition, approximately one-half of NF1 patients exhibit learning disabilities. To characterize NF1 function both in vitro and in vivo, we circumvent the embryonic lethality of NF1 null mouse embryos by generating a conditional mutation in the NF1 gene using Cre/loxP technology. Introduction of a Synapsin I promoter driven Cre transgenic mouse strain into the conditional NF1 background has ablated NF1 function in most differentiated neuronal populations. These mice have abnormal development of the cerebral cortex, which suggests that NF1 has an indispensable role in this aspect of CNS development. Furthermore, although they are tumor free, these mice display extensive astrogliosis in the absence of conspicuous neurodegeneration or microgliosis. These results indicate that NF1-deficient neurons are capable of inducing reactive astrogliosis via a non-cell autonomous mechanism.
Ablation of NF1 function in neurons induces abnormal development of cerebral cortex and reactive gliosis in the brain.
33835579
Tuberculosis remains one of the world's leading infectious causes of death. Approximately 80% of all disease is due to postprimary (secondary) tuberculosis in the lung. Unfortunately, tissues of developing lesions are seldom available and there are no recognized models of postprimary tuberculosis. In the preantibiotic era when tissues were more abundant, several investigators described early postprimary tuberculosis as a lipid pneumonia quite different from the caseating granulomas commonly described today. We used histopathologic, immunohistochemical and acid fast stains to examine tissues from several people with untreated primary and postprimary tuberculosis and compared the findings with those of mice with reactivation tuberculosis. The results confirmed that developing postprimary tuberculosis begins as a lipid pneumonia accompanied by bronchial obstruction in which infection is restricted to foamy alveolar macrophages. Cavities result from a combination of caseation of tuberculous pneumonia and microvascular occlusion characteristic of delayed type hypersensitivity (DTH). Reactivation tuberculosis in the mouse begins as a similar tuberculous lipid pneumonia with bronchial obstruction and evidence for participation of DTH. Developing necrosis in both species is associated with localization of organisms within lipid droplets. These results suggest that reactivation tuberculosis in mice is a valuable model of developing human postprimary tuberculosis.
Pathology of postprimary tuberculosis in humans and mice: contradiction of long-held beliefs.
33872649
CONTEXT Bioterrorist attacks involving letters and mail-handling systems in Washington, DC, resulted in Bacillus anthracis (anthrax) spore contamination in the Hart Senate Office Building and other facilities in the US Capitol's vicinity. OBJECTIVE To provide information about the nature and extent of indoor secondary aerosolization of B anthracis spores. DESIGN Stationary and personal air samples, surface dust, and swab samples were collected under semiquiescent (minimal activities) and then simulated active office conditions to estimate secondary aerosolization of B anthracis spores. Nominal size characteristics, airborne concentrations, and surface contamination of B anthracis particles (colony-forming units) were evaluated. RESULTS Viable B anthracis spores reaerosolized under semiquiescent conditions, with a marked increase in reaerosolization during simulated active office conditions. Increases were observed for B anthracis collected on open sheep blood agar plates (P<.001) and personal air monitors (P =.01) during active office conditions. More than 80% of the B anthracis particles collected on stationary monitors were within an alveolar respirable size range of 0.95 to 3.5 micro m. CONCLUSIONS Bacillus anthracis spores used in a recent terrorist incident reaerosolized under common office activities. These findings have important implications for appropriate respiratory protection, remediation, and reoccupancy of contaminated office environments.
Secondary aerosolization of viable Bacillus anthracis spores in a contaminated US Senate Office.
33884866
OBJECTIVE The sphingosine-1-phosphate (S1P) receptor agonist fingolimod (FTY720), that has shown efficacy in advanced multiple sclerosis clinical trials, decreases reperfusion injury in heart, liver, and kidney. We therefore tested the therapeutic effects of fingolimod in several rodent models of focal cerebral ischemia. To assess the translational significance of these findings, we asked whether fingolimod improved long-term behavioral outcomes, whether delayed treatment was still effective, and whether neuroprotection can be obtained in a second species. METHODS We used rodent models of middle cerebral artery occlusion and cell-culture models of neurotoxicity and inflammation to examine the therapeutic potential and mechanisms of neuroprotection by fingolimod. RESULTS In a transient mouse model, fingolimod reduced infarct size, neurological deficit, edema, and the number of dying cells in the core and periinfarct area. Neuroprotection was accompanied by decreased inflammation, as fingolimod-treated mice had fewer activated neutrophils, microglia/macrophages, and intercellular adhesion molecule-1 (ICAM-1)-positive blood vessels. Fingolimod-treated mice showed a smaller infarct and performed better in behavioral tests up to 15 days after ischemia. Reduced infarct was observed in a permanent model even when mice were treated 4 hours after ischemic onset. Fingolimod also decreased infarct size in a rat model of focal ischemia. Fingolimod did not protect primary neurons against glutamate excitotoxicity or hydrogen peroxide, but decreased ICAM-1 expression in brain endothelial cells stimulated by tumor necrosis factor alpha. INTERPRETATION These findings suggest that anti-inflammatory mechanisms, and possibly vasculoprotection, rather than direct effects on neurons, underlie the beneficial effects of fingolimod after stroke. S1P receptors are a highly promising target in stroke treatment.
Fingolimod provides long-term protection in rodent models of cerebral ischemia.
33904473
Regeneration of cardiac tissue has the potential to transform cardiovascular medicine. Recent advances in stem cell biology and direct reprogramming, or transdifferentiation, have produced powerful new tools to advance this goal. In this Review we examine key developments in the generation of new cardiomyocytes in vitro as well as the exciting progress that has been made toward in vivo reprogramming of cardiac tissue. We also address controversies and hurdles that challenge the field.
Induced regeneration—the progress and promise of direct reprogramming for heart repair
33904789
Measurements of carcinoembryonic antigen (CEA) in blood increased dramatically in some patients who were receiving injections of monoclonal antibody. CEA titers were measured with a monoclonal antibody-based double-determinant enzyme immunoassay in which untreated plasma specimens were diluted with an equal volume of buffer containing mouse serum. Increasing CEA titers were accompanied by the appearance and coincident increase in titers of human antibody against mouse Ig (HAMA). Adsorption of these sera with solid-phase anti-human IgG or Protein A restored antigen titers to pretreatment values; evidently the serum factor eliciting false-positive CEA titers was most probably HAMA. Neither addition of undiluted mouse serum to the assay mixture nor pretreatment by heating plasma specimens to 70 degrees C effectively abolished HAMA interference. By contrast, protein precipitation with polyethylene glycol (130 g/L) or heating plasma samples to 90 degrees C eliminated false-positive titers caused by HAMA, but did not reduce authentic CEA titers.
"Sandwich"-type immunoassay of carcinoembryonic antigen in patients receiving murine monoclonal antibodies for diagnosis and therapy.
33911859
Impaired axonal transport in motor neurons has been proposed as a mechanism for neuronal degeneration in motor neuron disease. Here we show linkage of a lower motor neuron disease to a region of 4 Mb at chromosome 2p13. Mutation analysis of a gene in this interval that encodes the largest subunit of the axonal transport protein dynactin showed a single base-pair change resulting in an amino-acid substitution that is predicted to distort the folding of dynactin's microtubule-binding domain. Binding assays show decreased binding of the mutant protein to microtubules. Our results show that dysfunction of dynactin-mediated transport can lead to human motor neuron disease.
Mutant dynactin in motor neuron disease
33912020
Semaphorin3A (Sema3A) is a repulsive guidance molecule for axons, which acts by inducing growth cone collapse through phosphorylation of CRMP2 (collapsin response mediator protein 2). Here, we show a role for CRMP2 oxidation and thioredoxin (TRX) in the regulation of CRMP2 phosphorylation and growth cone collapse. Sema3A stimulation generated hydrogen peroxide (H2O2) through MICAL (molecule interacting with CasL) and oxidized CRMP2, enabling it to form a disulfide-linked homodimer through cysteine-504. Oxidized CRMP2 then formed a transient disulfide-linked complex with TRX, which stimulated CRMP2 phosphorylation by glycogen synthase kinase-3, leading to growth cone collapse. We also reconstituted oxidation-dependent phosphorylation of CRMP2 in vitro, using a limited set of purified proteins. Our results not only clarify the importance of H2O2 and CRMP2 oxidation in Sema3A-induced growth cone collapse but also indicate an unappreciated role for TRX in linking CRMP2 oxidation to phosphorylation.
Thioredoxin mediates oxidation-dependent phosphorylation of CRMP2 and growth cone collapse.
33912748
OBJECTIVE To determine if n-3 polyunsaturated fatty acid (PUFA) supplementation (versus treatment with n-6 polyunsaturated or other fatty acid supplements) affects the metabolism of osteoarthritic (OA) cartilage. METHODS The metabolic profile of human OA cartilage was determined at the time of harvest and after 24-hour exposure to n-3 PUFAs or other classes of fatty acids, followed by explant culture for 4 days in the presence or absence of interleukin-1 (IL-1). Parameters measured were glycosaminoglycan release, aggrecanase and matrix metalloproteinase (MMP) activity, and the levels of expression of messenger RNA (mRNA) for mediators of inflammation, aggrecanases, MMPs, and their natural tissue inhibitors (tissue inhibitors of metalloproteinases [TIMPs]). RESULTS Supplementation with n-3 PUFA (but not other fatty acids) reduced, in a dose-dependent manner, the endogenous and IL-1-induced release of proteoglycan metabolites from articular cartilage explants and specifically abolished endogenous aggrecanase and collagenase proteolytic activity. Similarly, expression of mRNA for ADAMTS-4, MMP-13, and MMP-3 (but not TIMP-1, -2, or -3) was also specifically abolished with n-3 PUFA supplementation. In addition, n-3 PUFA supplementation abolished the expression of mRNA for mediators of inflammation (cyclooxygenase 2, 5-lipoxygenase, 5-lipoxygenase-activating protein, tumor necrosis factor alpha, IL-1alpha, and IL-1beta) without affecting the expression of message for several other proteins involved in normal tissue homeostasis. CONCLUSION These studies show that the pathologic indicators manifested in human OA cartilage can be significantly altered by exposure of the cartilage to n-3 PUFA, but not to other classes of fatty acids.
Pathologic indicators of degradation and inflammation in human osteoarthritic cartilage are abrogated by exposure to n-3 fatty acids.
33918970
OBJECTIVE Oligofructose (OFS) is a prebiotic that reduces energy intake and fat mass via changes in gut satiety hormones and microbiota. The effects of OFS may vary depending on predisposition to obesity. The aim of this study was to examine the effect of OFS in diet-induced obese (DIO) and diet-resistant (DR) rats. METHODS Adult, male DIO, and DR rats were randomized to: high-fat/high-sucrose (HFS) diet or HFS diet + 10% OFS for 6 weeks. Body composition, food intake, gut microbiota, plasma gut hormones, and cannabinoid CB(1) receptor expression in the nodose ganglia were measured. RESULTS OFS reduced body weight, energy intake, and fat mass in both phenotypes (P < 0.05). Select gut microbiota differed in DIO versus DR rats (P < 0.05), the differences being eliminated by OFS. OFS did not modify plasma ghrelin or CB(1) expression in nodose ganglia, but plasma levels of GIP were reduced and PYY were elevated (P < 0.05) by OFS. CONCLUSIONS OFS was able to reduce body weight and adiposity in both prone and resistant obese phenotypes. OFS-induced changes in gut microbiota profiles in DIO and DR rats, along with changes in gut hormone levels, likely contribute to the sustained lower body weights.
Interactive effects of oligofructose and obesity predisposition on gut hormones and microbiota in diet-induced obese rats.
33920995
No direct evidence has been reported whether the spatial organization of ICAM-1 on the cell surface is linked to its physiological function in terms of leukocyte adhesion and transendothelial migration (TEM). Here we observed that ICAM-1 by itself directly regulates the de novo elongation of microvilli and is thereby clustered on the microvilli. However, truncation of the intracellular domain resulted in uniform cell surface distribution of ICAM-1. Mutation analysis revealed that the C-terminal 21 amino acids are dispensable, whereas a segment of 5 amino acids ((507)RKIKK(511)) in the NH-terminal third of intracellular domain, is required for the proper localization and dynamic distribution of ICAM-1 and the association of ICAM-1 with F-actin, ezrin, and moesin. Importantly, deletion of the (507)RKIKK(511) significantly delayed the LFA-1-dependent membrane projection and decreased leukocyte adhesion and subsequent TEM. Endothelial cells treated with cell-permeant penetratin-ICAM-1 peptides comprising ICAM-1 RKIKK sequences inhibited leukocyte TEM. Collectively, these findings demonstrate that (507)RKIKK(511) is an essential motif for the microvillus ICAM-1 presentation and further suggest a novel regulatory role for ICAM-1 topography in leukocyte TEM.
RKIKK motif in the intracellular domain is critical for spatial and dynamic organization of ICAM-1: functional implication for the leukocyte adhesion and transmigration.
33934971
The first experimental vaccination against ticks was carried out 60 years ago. Since then, progress has been slow, although the recent commercial release of a recombinant vaccine against Boophilus microplus is significant. The nature of naturally acquired protective immunity against ticks is poorly understood, particularly in the important, domesticated ruminant hosts. Characterization of the antigens of naturally acquired immunity remains limited, although more has been achieved with 'concealed' antigens. Crucial questions remain about the true impact of tick-induced immunosuppression and the effect of immunity on the transmission of tick-borne diseases, despite some fascinating and important recent results, as discussed here by Peter Willadsen and Frans Jongejan.
Immunology of the tick-host interaction and the control of ticks and tick-borne diseases.
33955641
Procedures are described for the isolation of lipoproteins from human serum by precipitation with polyanions and divalent cations. A mixture of low and very low density lipoproteins can be prepared without ultracentrifugation by precipitation with heparin and either MnCl(2) alone or MgCl(2) plus sucrose. In both cases the precipitation is reversible, selective, and complete. The highly concentrated isolated lipoproteins are free of other plasma proteins as judged by immunological and electrophoretic methods. The low density and very low density lipoproteins can then be separated from each other by ultracentrifugation. The advantage of the method is that large amounts of lipoproteins can be prepared with only a single preparative ultracentrifugation. Polyanions other than heparin may also be used; when the precipitation of the low and very low density lipoproteins is achieved with dextran sulfate and MnCl(2), or sodium phosphotungstate and MgCl(2), the high density lipoproteins can subsequently be precipitated by increasing the concentrations of the reagents. These lipoproteins, containing small amounts of protein contaminants, are further purified by ultracentrifugation at d 1.22. With a single preparative ultracentrifugation, immunologically pure high density lipoproteins can be isolated from large volumes of serum.
Rapid method for the isolation of lipoproteins from human serum by precipitation with polyanions.
33960383
Abstract Evidence obtained in the 1990's strongly supports the notion that glycaemic control is important not only in Type I (insulin-dependent), but also in Type II (non-insulin-dependent) diabetes mellitus. Although measurement of HbA1c is the standard for assessing the effect of glucose control in the occurrence and prevention of diabetic sequelae, more recent evidence indicates that other glucose parameters are also important. Postchallenge and postprandial hyperglycaemic peaks seem to be prospective determinants of vascular damage in early Type II diabetes. Currently, there is no overall accepted standard approach for the pharmacological management of Type II diabetes. The United Kingdom Prospective Diabetes Study has shown that reaching a near-normal glycaemic target is critically important and the pharmacotherapy of this progressive disease is difficult. Loss of endogenous insulin secretion has been substantiated to cause the progression of Type II diabetes in the United Kingdom Prospective Diabetes Study. Early insulinization, however, was not advantageous over other forms of therapy. The advent of polypharmacy in recent years has greatly strengthened the treatment of this disease. This synergy has been extended of late with the development of early-phase insulin secretion agents. Two such agents, nateglinide and repaglinide, can be used to reduce mealtime glucose excursions and HbA1c as monotherapy, and in combination with metformin; their antidiabetic potential is similar to the combination treatment with glibenclamide and metformin. Additional substantiation of their long-term effect on improving life expectancy and reducing diabetic complications in Type II diabetic patients is now required.
The role of oral antidiabetic agents: why and when to use an early-phase insulin secretion agent in Type II diabetes mellitus
33986200
Probing a wide range of cellular phenotypes in neurodevelopmental disorders using patient-derived neural progenitor cells (NPCs) can be facilitated by 3D assays, as 2D systems cannot entirely recapitulate the arrangement of cells in the brain. Here, we developed a previously unidentified 3D migration and differentiation assay in layered hydrogels to examine how these processes are affected in neurodevelopmental disorders, such as Rett syndrome. Our soft 3D system mimics the brain environment and accelerates maturation of neurons from human induced pluripotent stem cell (iPSC)-derived NPCs, yielding electrophysiologically active neurons within just 3 wk. Using this platform, we revealed a genotype-specific effect of methyl-CpG-binding protein-2 (MeCP2) dysfunction on iPSC-derived neuronal migration and maturation (reduced neurite outgrowth and fewer synapses) in 3D layered hydrogels. Thus, this 3D system expands the range of neural phenotypes that can be studied in vitro to include those influenced by physical and mechanical stimuli or requiring specific arrangements of multiple cell types.
Layered hydrogels accelerate iPSC-derived neuronal maturation and reveal migration defects caused by MeCP2 dysfunction.
33986507
The rapid activation of gene expression in response to stimuli occurs largely through the regulation of RNA polymerase II-dependent transcription. In this Review, we discuss events that occur during the transcription cycle in eukaryotes that are important for the rapid and specific activation of gene expression in response to external stimuli. In addition to regulated recruitment of the transcription machinery to the promoter, it has now been shown that control steps can include chromatin remodelling and the release of paused polymerase. Recent work suggests that some components of signal transduction cascades also play an integral part in activating transcription at target genes.
Inducible gene expression: diverse regulatory mechanisms
33989422
Comment on: Chan KL, Palmai-Pallag T, Ying S, Hickson ID. Replication stress induces sister-chromatid bridging at fragile site loci in mitosis. Nat Cell Biol 2009; 11:753-60.
On the origins of ultra-fine anaphase bridges.
34016944
PURPOSE Tyrosine kinase (TK) inhibitors are emerging as a promising new approach to the treatment of HER overexpressing tumors, however optimal use of these agents awaits further definition of the downstream signaling pathways that mediate their effects. We reported previously that both EGFR- and Her2-overexpressing tumors are sensitive to the new EGFR-selective TK inhibitor gefitinib (ZD1839, "Iressa"), and sensitivity to this agent correlated with its ability to down-regulate Akt. However, EGFR-overexpressing MDA-468 cells, which lack PTEN function, are resistant to ZD1839, and ZD1839 is unable to down-regulate Akt activity in these cells. EXPERIMENTAL DESIGN To study the role of PTEN function, we generated MDA468 cells with tet-inducible PTEN expression. RESULTS We show here that the resistance of MDA-468 cells to ZD1839 is attributable to EGFR-independent constitutive Akt activation caused by loss of PTEN function in these cells. Reconstitution of PTEN function through tet-inducible expression restores ZD1839 sensitivity to these cells and reestablishes EGFR-stimulated Akt signaling. Although restoration of PTEN function to tumors is difficult to implement clinically, much of the effects of PTEN loss are attributable to overactive PI3K/Akt pathway signaling, and this overactivity can be modulated by pharmacologic approaches. We show here that pharmacologic down-regulation of constitutive PI3K/Akt pathway signaling using the PI3K inhibitor LY294002 similarly restores EGFR-stimulated Akt signaling and sensitizes MDA-468 cells to ZD1839. CONCLUSIONS Sensitivity to ZD1839 requires intact growth factor receptor-stimulated Akt signaling activity. PTEN loss leads to uncoupling of this signaling pathway and results in ZD1839 resistance, which can be reversed with reintroduction of PTEN or pharmacologic down-regulation of constitutive PI3K/Akt pathway activity. These data have important predictive and therapeutic clinical implications.
Resistance to gefitinib in PTEN-null HER-overexpressing tumor cells can be overcome through restoration of PTEN function or pharmacologic modulation of constitutive phosphatidylinositol 3'-kinase/Akt pathway signaling.
34016987
Monocytes are primary targets for human CMV (HCMV) infection and are proposed to be responsible for hematogenous dissemination of the virus. Monocytes acquire different functional traits during polarization to the classical proinflammatory M1 macrophage or the alternative antiinflammatory M2 macrophage. We hypothesized that HCMV induced a proinflammatory M1 macrophage following infection to promote viral dissemination because, biologically, a proinflammatory state provides the tools to drive infected monocytes from the blood into the tissue. To test this hypothesis of monocyte conversion from a normal quiescent phenotype to an inflammatory phenotype, we used Affymetrix Microarray to acquire a transcriptional profile of infected monocytes at a time point our data emphasized is a key temporal regulatory point following infection. We found that HCMV significantly up-regulated 583 (5.2%) of the total genes and down-regulated 621 (5.5%) of the total genes>or=1.5-fold at 4 h postinfection. Further ontology analysis revealed that genes implicated in classical M1 macrophage activation were stimulated by HCMV infection. We found that 65% of genes strictly associated with M1 polarization were up-regulated, while only 4% of genes solely associated with M2 polarization were up-regulated. Analysis of the monocyte chemokinome at the transcriptional level showed that 44% of M1 and 33% of M2 macrophage chemokines were up-regulated. Proteomic analysis using chemokine Ab arrays confirmed the secretion of these chemotactic proteins from HCMV-infected monocytes. Overall, the results identify that the HCMV-infected monocyte transcriptome displayed a unique M1/M2 polarization signature that was skewed toward the classical M1 activation phenotype.
Transcriptome analysis reveals human cytomegalovirus reprograms monocyte differentiation toward an M1 macrophage.
34025053
BACKGROUND Type 1 diabetes results from T-cell-mediated destruction of β cells. Findings from preclinical studies and pilot clinical trials suggest that antithymocyte globulin (ATG) might be effective for reducing this autoimmune response. We assessed the safety and efficacy of rabbit ATG in preserving islet function in participants with recent-onset type 1 diabetes, and report here our 12-month results. METHODS For this phase 2, randomised, placebo-controlled, clinical trial, we enrolled patients with recent-onset type 1 diabetes, aged 12-35 years, and with a peak C-peptide of 0.4 nM or greater on mixed meal tolerance test from 11 sites in the USA. We used a computer generated randomisation sequence to randomly assign patients (2:1, with permuted-blocks of size three or six and stratified by study site) to receive either 6.5 mg/kg ATG or placebo over a course of four days. All participants were masked and initially managed by an unmasked drug management team, which managed all aspects of the study until month 3. Thereafter, to maintain masking for diabetes management throughout the remainder of the study, participants received diabetes management from an independent, masked study physician and nurse educator. The primary endpoint was the baseline-adjusted change in 2-h area under the curve C-peptide response to mixed meal tolerance test from baseline to 12 months. Analyses were by intention to treat. This is a planned interim analysis of an on-going trial that will run for 24 months of follow-up. This study is registered with ClinicalTrials.gov, number NCT00515099. FINDINGS Between Sept 10, 2007, and June 1, 2011, we screened 154 individuals, randomly allocating 38 to ATG and 20 to placebo. We recorded no between-group difference in the primary endpoint: participants in the ATG group had a mean change in C-peptide area under the curve of -0.195 pmol/mL (95% CI -0.292 to -0.098) and those in the placebo group had a mean change of -0.239 pmol/mL (-0.361 to -0.118) in the placebo group (p=0.591). All except one participant in the ATG group had both cytokine release syndrome and serum sickness, which was associated with a transient rise in interleukin-6 and acute-phase proteins. Acute T cell depletion occurred in the ATG group, with slow reconstitution over 12 months. However, effector memory T cells were not depleted, and the ratio of regulatory to effector memory T cells declined in the first 6 months and stabilised thereafter. ATG-treated patients had 159 grade 3-4 adverse events, many associated with T-cell depletion, compared with 13 in the placebo group, but we detected no between-group difference in incidence of infectious diseases. INTERPRETATION Our findings suggest that a brief course of ATG does not result in preservation of β-cell function 12 months later in patients with new-onset type 1 diabetes. Generalised T-cell depletion in the absence of specific depletion of effector memory T cells and preservation of regulatory T cells seems to be an ineffective treatment for type 1 diabetes.
Antithymocyte globulin treatment for patients with recent-onset type 1 diabetes: 12-month results of a randomised, placebo-controlled, phase 2 trial.
34034749
Ever since the discovery of the nucleosome in 1974, scientists have stumbled upon discrete particles in which DNA is wrapped around histone complexes of different stoichiometries: octasomes, hexasomes, tetrasomes, "split" half-nucleosomes, and, recently, bona fide hemisomes. Do all these particles exist in vivo? Under what conditions? What is their physiological significance in the complex DNA transactions in the eukaryotic nucleus? What are their dynamics? This review summarizes research spanning more than three decades and provides a new meaning to the term "nucleosome. " The nucleosome can no longer be viewed as a single static entity: rather, it is a family of particles differing in their structural and dynamic properties, leading to different functionalities.
The nucleosome family: dynamic and growing.
34054472
BACKGROUND Accumulating evidence has indicated that corin plays critical roles in regulating salt-water balance, blood pressure and cardiac function by activating natriuretic peptides. The present case-control study was designed to evaluate the association of serum soluble corin with acute myocardial infarction (AMI). METHODS We enrolled 856 consecutive AMI patients and 856 control subjects and explored the possible relation between serum corin levels and AMI risk using logistic regression model. RESULTS Patients with AMI had higher BMI, were less physically active, and were more likely to have histories of hypertension, diabetes, hyperlipidemia and smoking compared with the controls. Serum levels of corin were remarkably reduced in AMI patients (825±263pg/ml) compared with those in healthy controls (1246±425pg/ml). Odds ratios of ST elevation (STEMI) and non-ST elevation myocardial infarction (NSTEMI) were significantly decreased with the increasing levels of serum corin in both men and women (P for trend, <0.001) after adjustment for body mass index, hypertension, diabetes, hyperlipidemia, smoking, and physical activity. CONCLUSIONS Our study demonstrates that serum levels of corin are significantly decreased in AMI patients, and it is inversely associated with the incidences of STEMI and NSTEMI in both men and women.
Association between serum corin levels and risk of acute myocardial infarction.
34066665
Breast cancer evolution and tumor progression are governed by the complex interactions between steroid receptor [estrogen receptor (ER) and progesterone receptor] and growth factor receptor signaling. In recent years, the field of cancer therapy has witnessed the emergence of multiple strategies targeting these specific cancer pathways and key molecules (ER and growth factor receptors) to arrest tumor growth and achieve tumor eradication; treatment success, however, has varied and both de novo (up front) and acquired resistance have proven a challenge. Recent studies of ER biology have revealed new insights into ER action in breast cancer and have highlighted the role of an intimate crosstalk between the ER and HER family signaling pathways as a fundamental contributor to the development of resistance to endocrine therapies against the ER pathway. The aim of this review article is to summarize the current knowledge on mechanisms of resistance of breast cancer cells to endocrine therapies due to the crosstalk between the ER and the HER growth factor receptor signaling pathways and to explore new available therapeutic strategies that could prolong duration of response and circumvent endocrine resistant tumor growth.
Crosstalk between the estrogen receptor and the HER tyrosine kinase receptor family: molecular mechanism and clinical implications for endocrine therapy resistance.
34071621
Vascular disease progression is associated with marked changes in vascular smooth muscle cell (SMC) phenotype and function. SMC contractile gene expression and, thus differentiation, is under direct transcriptional control by the transcription factor, serum response factor (SRF); however, the mechanisms dynamically regulating SMC phenotype are not fully defined. Here we report that the lipid and protein phosphatase, PTEN, has a novel role in the nucleus by functioning as an indispensible regulator with SRF to maintain the differentiated SM phenotype. PTEN interacts with the N-terminal domain of SRF and PTEN-SRF interaction promotes SRF binding to essential promoter elements in SM-specific genes. Factors inducing phenotypic switching promote loss of nuclear PTEN through nucleo-cytoplasmic translocation resulting in reduced myogenically active SRF, but enhanced SRF activity on target genes involved in proliferation. Overall decreased expression of PTEN was observed in intimal SMCs of human atherosclerotic lesions underlying the potential clinical importance of these findings.
Nuclear PTEN functions as an essential regulator of SRF-dependent transcription to control smooth muscle differentiation
34074902
Abstract Feline leukemia virus (FeLV), Gammaretrovirus, and feline immunodeficiency virus, a Lentivirus, are members of the family Retroviridae, and may establish persistent infections in the domestic cat (Felis catus). Cytoproliferative and cytosuppressive disorders may result from infection with these viruses. Morbidity and mortality rates are high in domestic cats worldwide. Infection of endangered neotropic small felids with these viruses could be devastating. To investigate the prevalence of FeLV and feline lentiviruses in neotropic small felids kept in captivity in São Paulo state, Brazil, serum samples from 104 animals belonging to the species Leopardus pardalis, Leopardus tigrinus, Leopardus wiedii, Herpailurus yaguarondi, and Oncifelis geoffroyi were tested for FeLV and feline lentiviruses by commercially available immunoassays. All results were negative, suggesting that retrovirus infection is not an important clinical problem in these populations. Because domestic cats in São Paulo city are naturally infected with these pathogens, and feral cats are commonly found in zoologic facilities in Brazil, preventive measures should be taken to avoid transmission of retroviruses to naive populations of wild and captive neotropic felids in Brazil.
SEROSURVEY FOR FELINE LEUKEMIA VIRUS AND LENTIVIRUSES IN CAPTIVE SMALL NEOTROPIC FELIDS IN SÃO PAULO STATE, BRAZIL
34101101
Several species of rodents are used to investigate the metabolism of quercetin in vivo. However, it is unclear whether they are a proper animal model. Thus, we compared the metabolism of quercetin in Wistar rats (rats), Balb/c mice (mice) and Mongolian gerbils (gerbils). We determined the levels of quercetin metabolites, quercetin-3-glucuronide (Q3G), quercetin-3′-sulfate (Q3′S) and methyl-quercetin isorhamnetin (IH), in the plasma, lungs and livers of three species of animals by high-performance liquid chromatography after acute and/or chronic quercetin administration. The metabolic enzyme activities in the intestinal mucosal membrane and liver were also investigated. First, we found that after acute quercetin administration, the Q3′S level was the highest in gerbils. However, after long-term supplementation (20 weeks), Q3G was the dominant metabolite in the plasma, lungs and livers followed by IH and Q3′S in all animals, although the gerbils still had a higher Q3′S conversion ratio. The average concentrations of total quercetin concentration in the plasma of gerbils were the highest in both short- and long-term studies. The activities of uridine 5′-diphosphate-glucuronosyltransferase, phenolsulfotransferase and catechol-O-methyltransferase were induced by quercetin in a dose- and tissue-dependent manner in all animals. Taken together, in general, after long-term supplementation the metabolism of quercetin is similar in all animals and is comparable to that of humans. However, the accumulation of quercetin and Q3′S conversion ratio in gerbils are higher than those in the other animals.
Comparing the metabolism of quercetin in rats, mice and gerbils
34103335
A long-standing hypothesis on tumorigenesis is that cell division failure, generating genetically unstable tetraploid cells, facilitates the development of aneuploid malignancies. Here we test this idea by transiently blocking cytokinesis in p53-null (p53-/-) mouse mammary epithelial cells (MMECs), enabling the isolation of diploid and tetraploid cultures. The tetraploid cells had an increase in the frequency of whole-chromosome mis-segregation and chromosomal rearrangements. Only the tetraploid cells were transformed in vitro after exposure to a carcinogen. Furthermore, in the absence of carcinogen, only the tetraploid cells gave rise to malignant mammary epithelial cancers when transplanted subcutaneously into nude mice. These tumours all contained numerous non-reciprocal translocations and an 8–30-fold amplification of a chromosomal region containing a cluster of matrix metalloproteinase (MMP) genes. MMP overexpression is linked to mammary tumours in humans and animal models. Thus, tetraploidy enhances the frequency of chromosomal alterations and promotes tumour development in p53-/- MMECs.
Cytokinesis failure generating tetraploids promotes tumorigenesis in p53-null cells
34105878
Claspin is required for the ATR-dependent activation of Chk1 in Xenopus egg extracts containing incompletely replicated DNA. We show here that Claspin associates with chromatin in a regulated manner during S phase. Binding of Claspin to chromatin depends on the pre-replication complex (pre-RC) and Cdc45 but not on replication protein A (RPA). These dependencies suggest that binding of Claspin occurs around the time of initial DNA unwinding at replication origins. By contrast, both ATR and Rad17 require RPA for association with DNA. Claspin, ATR, and Rad17 all bind to chromatin independently. These findings suggest that Claspin plays a role in monitoring DNA replication during S phase. Claspin, ATR, and Rad17 may collaborate in checkpoint regulation by detecting different aspects of a DNA replication fork.
Claspin, a Chk1-regulatory protein, monitors DNA replication on chromatin independently of RPA, ATR, and Rad17.
34121231
INTRODUCTION Cold-related respiratory symptoms are common among northern populations, especially among people suffering from respiratory diseases. However, the prevalence of such symptoms in the general population and the threshold temperatures at which the symptoms start to emerge are poorly known. OBJECTIVES The present study determined the prevalence and threshold temperatures of self-reported respiratory symptoms related to cold, separately for healthy people and those with respiratory disease. MATERIALS AND METHODS Six thousand five hundred ninety-one men and women aged 25 years-74 years from the national FINRISK study were queried about cold-related respiratory symptoms. The results were expressed as age-adjusted prevalence figures and coefficients from multivariate regressions. RESULTS Cold-related respiratory symptoms were more often reported by people with asthma (men 69%/women 78%) and by subjects with chronic bronchitis (65%/76%) than the healthy subjects (18%/21%). A binomial regression showed an increase of symptom prevalence by age and excesses of 4%, 50% and 21% units because of female sex, asthma and chronic bronchitis, respectively. The reported threshold temperature for cold-related symptoms was -14 degrees C for males and -15 degrees C for females, and it showed some increase by age (0 degrees C-5 degrees C), asthma (2 degrees C) and chronic bronchitis (3 degrees C). The threshold temperature for mucus production was exceptional as it decreased by age (2 degrees C-5 degrees C) and asthma (2 degrees C). The effects of smoking and education were marginal. CONCLUSION Cold-related respiratory symptoms are common in patients with chronic respiratory diseases, but they start to emerge at relatively low temperatures. In a cold climate, the cold-related symptoms may have an impact on the health-related quality of life.
Cold-related respiratory symptoms in the general population.
34139429
CONTEXT Although beta-blockers improve symptoms and survival in adults with heart failure, little is known about these medications in children and adolescents. OBJECTIVE To prospectively evaluate the effects of carvedilol in children and adolescents with symptomatic systemic ventricular systolic dysfunction. DESIGN, SETTING, AND PARTICIPANTS A multicenter, randomized, double-blind, placebo-controlled study of 161 children and adolescents with symptomatic systolic heart failure from 26 US centers. In addition to treatment with conventional heart failure medications, patients were assigned to receive placebo or carvedilol. Enrollment began in June 2000 and the last dose was given in May 2005 (each patient received medication for 8 months). INTERVENTIONS Patients were randomized in a 1:1:1 ratio to twice-daily dosing with placebo, low-dose carvedilol (0.2 mg/kg per dose if weight <62.5 kg or 12.5 mg per dose if weight > or =62.5 kg), or high-dose carvedilol (0.4 mg/kg per dose if weight <62.5 kg or 25 mg per dose if weight > or =62.5 kg) and were stratified according to whether each patient's systemic ventricle was a left ventricle or not. MAIN OUTCOME MEASURES The primary outcome was a composite measure of heart failure outcomes in patients receiving carvedilol (low- and high-dose combined) vs placebo. Secondary efficacy variables included individual components of this composite, echocardiographic measures, and plasma b-type natriuretic peptide levels. RESULTS There was no statistically significant difference between groups for the composite end point based on the percentage of patients who improved, worsened, or were unchanged. Among 54 patients assigned to placebo, 30 improved (56%), 16 worsened (30%), and 8 were unchanged (15%); among 103 patients assigned to carvedilol, 58 improved (56%), 25 worsened (24%), and 20 were unchanged (19%). The rates of worsening were lower than expected. The odds ratio for worsened outcome for patients in the combined carvedilol group vs the placebo group was 0.79 (95% CI, 0.36-1.59; P = .47). A prespecified subgroup analysis noted significant interaction between treatment and ventricular morphology (P = .02), indicating a possible differential effect of treatment between patients with a systemic left ventricle (beneficial trend) and those whose systemic ventricle was not a left ventricle (nonbeneficial trend). CONCLUSIONS These preliminary results suggest that carvedilol does not significantly improve clinical heart failure outcomes in children and adolescents with symptomatic systolic heart failure. However, given the lower than expected event rates, the trial may have been underpowered. There may be a differential effect of carvedilol in children and adolescents based on ventricular morphology. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00052026.
Carvedilol for children and adolescents with heart failure: a randomized controlled trial.
34189936
Malignant pleural mesothelioma (MPM) is a highly aggressive neoplasm arising from the mesothelial cells lining the parietal pleura and it exhibits poor prognosis. Although there has been significant progress in MPM treatment, development of more efficient therapeutic approaches is needed. BMAL1 is a core component of the circadian clock machinery and its constitutive overexpression in MPM has been reported. Here, we demonstrate that BMAL1 may serve as a molecular target for MPM. The majority of MPM cell lines and a subset of MPM clinical specimens expressed higher levels of BMAL1 compared to a nontumorigenic mesothelial cell line (MeT-5A) and normal parietal pleural specimens, respectively. A serum shock induced a rhythmical BMAL1 expression change in MeT-5A but not in ACC-MESO-1, suggesting that the circadian rhythm pathway is deregulated in MPM cells. BMAL1 knockdown suppressed proliferation and anchorage-dependent and independent clonal growth in two MPM cell lines (ACC-MESO-1 and H290) but not in MeT-5A. Notably, BMAL1 depletion resulted in cell cycle disruption with a substantial increase in apoptotic and polyploidy cell population in association with downregulation of Wee1, cyclin B and p21(WAF1/CIP1) and upregulation of cyclin E expression. BMAL1 knockdown induced mitotic catastrophe as denoted by disruption of cell cycle regulators and induction of drastic morphological changes including micronucleation and multiple nuclei in ACC-MESO-1 cells that expressed the highest level of BMAL1. Taken together, these findings indicate that BMAL1 has a critical role in MPM and could serve as an attractive therapeutic target for MPM.
The circadian clock gene BMAL1 is a novel therapeutic target for malignant pleural mesothelioma.
34198365
Covalent DNA-protein crosslinks (DPCs) are toxic DNA lesions that interfere with essential chromatin transactions, such as replication and transcription. Little was known about DPC-specific repair mechanisms until the recent identification of a DPC-processing protease in yeast. The existence of a DPC protease in higher eukaryotes is inferred from data in Xenopus laevis egg extracts, but its identity remains elusive. Here we identify the metalloprotease SPRTN as the DPC protease acting in metazoans. Loss of SPRTN results in failure to repair DPCs and hypersensitivity to DPC-inducing agents. SPRTN accomplishes DPC processing through a unique DNA-induced protease activity, which is controlled by several sophisticated regulatory mechanisms. Cellular, biochemical, and structural studies define a DNA switch triggering its protease activity, a ubiquitin switch controlling SPRTN chromatin accessibility, and regulatory autocatalytic cleavage. Our data also provide a molecular explanation on how SPRTN deficiency causes the premature aging and cancer predisposition disorder Ruijs-Aalfs syndrome.
Mechanism and Regulation of DNA-Protein Crosslink Repair by the DNA-Dependent Metalloprotease SPRTN
34198460
BACKGROUND Given the high value placed on children in sub-Saharan Africa, previous research suggests that infertility increases the risk of psychological distress and marital conflict, encourages risky sexual behavior and deprives infertile individuals and couples of an important source of economic and social capital. This paper explores the implications of infertility for women in Ghana, West Africa. METHODS Semi-structured interview data collected from 107 women (aged 21-48 years, mean 33 years) seeking treatment in gynecological and obstetric clinics in Accra, Ghana, are analyzed. Based on iterative open coding of the interviews, the focus of the analysis is on mental health, marital instability, social interaction and gendered experiences. RESULTS Infertile women report facing severe social stigma, marital strain and a range of mental health difficulties. Many women feel that they shoulder a disproportionate share of the blame for infertility and, by extension, face greater social consequences than male partners for difficulties conceiving. Women who do not self-identify as infertile corroborate these findings, asserting that the social consequences of infertility are severe, particularly for women. CONCLUSIONS Infertility in Ghana has important consequences for social interactions, marital stability and mental health. These consequences are not perceived to be shared equally by Ghanaian men.
'Zero is not good for me': implications of infertility in Ghana.
34208005
OBJECTIVES The original objective was to determine whether the use of bilevel positive airway pressure (BiPAP) ventilation would reduce the need for endotracheal intubation, the length of hospital stay, and hospital charges in patients with status asthmaticus. The development of physician treatment bias made patient enrollment difficult. The article subsequently describes the use of Bayesian statistics to explain study results when this bias occurs. METHODS This study was a prospective, randomized controlled clinical trial conducted over a 34.5-month period at an urban university hospital with an emergency department census of 94,000 annual visits. Patients remaining in status asthmaticus after initial standard treatment with inhaled beta-agonists and steroids were randomized to receive BiPAP ventilation plus standard treatment versus standard treatment alone (non-BiPAP), with intubation for either group as needed. Patients with concurrent cardiac or other pulmonary diseases were excluded. The primary outcome measures were endotracheal intubation rate and length of hospital stay. Secondary outcome measures included vital signs (respiratory rate, pulse rate, blood pressure), changes in expiratory peak flow, changes in pulse oximetry values, and hospital charges. Data were analyzed using Fisher's exact test, Mann-Whitney tests, and Bayesian statistics. For patients enrolled in the study more than once, data analysis was performed on the first enrollment only. RESULTS Nineteen patients were enrolled in the BiPAP group and 16 patients in the non-BiPAP group. Patients were frequently enrolled more than once and the data from the subsequent enrollments were excluded from the analysis. A marked decrease in enrollment, due to physician treatment bias, led to a premature termination of the study. Demographics showed that the groups were similar in age, sex, initial peak flow rate, and arterial blood gas measurements. There was a 7.3% increase (95% CI = -22 to +45) in the intubation rate in the non-BiPAP group (n = 2) compared with that for the BiPAP group (n = 1). No significant difference was seen in length of hospital stay or hospital charges, although there was a favorable trend toward the BiPAP group. Complications encountered in the BiPAP group included one patient with discomfort associated with the nasal BiPAP mask. Bayesian analysis demonstrated that in order for the collected data to be convincing at the 95% confidence level, the prior conviction among treating physicians that BiPAP was a successful treatment modality would have had to be 98.9%. CONCLUSIONS In this study, BiPAP appeared to have no deleterious effects in patients with status asthmaticus, with a trend toward decreased endotracheal intubation rate, decreased length of hospital stay, and decreased hospital charges. Although further study with more patients is needed to determine the clinical and statistical significance of this intervention, ethical concerns regarding withholding BiPAP treatment from the patients in the control group forced a premature termination of the study in the authors' institution.
Ethical dilemmas in a randomized trial of asthma treatment: can Bayesian statistical analysis explain the results?
34227917
OBJECTIVE To review the literature on mental health and psychiatric morbidity in prison populations and relate findings to a Danish study on remand prisoners. METHOD The literature is reviewed and subdivided in the following section: validity of psychometrics in prison populations, prevalence of psychiatric disorders prior to imprisonment, incidence of psychiatric disorders during imprisonment, psychopathy related to psychiatric comorbidity, dependence syndromes with special emphasis on different administrations of heroin use (smoke vs. injection). The results are compared with a longitudinal Danish study on remand prisoners in either solitary confinement (SC) or non-SC. RESULTS Many factors must be taken into consideration when dealing with prisoners and mental health, e.g. international differences, the prison setting, demographics and methodological issues. The prison populations in general are increasing worldwide. Psychometrics may perform differently in prison populations compared with general populations with the General Health Questionnaire-28 having a low validity in remand prisoners. Psychiatric morbidity including schizophrenia is higher and perhaps increasing in prison populations compared with general populations with dependence syndromes being the most frequent disorders. The early phase of imprisonment is a vulnerable period with a moderately high incidence of adjustment disorders and twice the incidence in SC compared with non-SC. Prevalence of psychopathy is lower in European than North American prisons. Medium to high scores of psychopathy is related to higher psychiatric comorbidity. Opioid dependence is the most frequent drug disorder with subjects using injection representing a more dysfunctional group than subjects using smoke administration. Many mentally ill prisoners remain undetected and undertreated. CONCLUSION There is a growing population of mentally ill prisoners being insufficiently detected and treated.
Mental health in prison populations. A review--with special emphasis on a study of Danish prisoners on remand.
34228604
Females live longer than males in many species, including humans. We have traced a possible explanation for this phenomenon to the beneficial action of estrogens, which bind to estrogen receptors and increase the expression of longevity-associated genes, including those encoding the antioxidant enzymes superoxide dismutase and glutathione peroxidase. As a result, mitochondria from females produce fewer reactive oxygen species than those from males. Administering estrogens has serious drawbacks, however--they are feminizing (and thus cannot be administered to males) and may increase the incidence of serious diseases such as uterine cancer in postmenopausal women. Phytoestrogens, which are present in soy or wine, may have some of the favorable effects of estrogens without their undesirable effects. Study of gender differences in longevity may help us to understand the basic processes of aging and to devise practical strategies to increase the longevity of both females and males.
Why females live longer than males: control of longevity by sex hormones.
34254203
In this Opinion article, I address the role of the pre-B-cell receptor (pre-BCR) in the development of antigen-specific B cells in terms of immunoglobulin heavy chain (IgH) variable-region repertoire selection, precursor B-cell differentiation and proliferation, and IgH allelic exclusion. Comparisons with the role of the pre-T-cell receptor (pre-TCR) in T-cell development raise provocative questions. Why do B- and T-cell lineages both use a surrogate chain — the surrogate light chain and the pre-TCR α-chain, respectively — as a step to develop their repertoires of antigen-recognizing cells? What are the functions of the pre-BCR and pre-TCR in lymphocyte differentiation and antigen-receptor allelic exclusion? This article, together with the accompanying article by Harald von Boehmer, hopes to answer some of these questions.
The pre-B-cell receptor: selector of fitting immunoglobulin heavy chains for the B-cell repertoire
34258065
Helicobacter infection is a chronic persistent condition which is responsible for the majority of cases of gastric and duodenal ulcers, and gastric cancer. The study of the bacteria, the interaction of the bacteria with the host, and the host immune response has greatly benefited from standardization of culture techniques and animal models. The following chapters will describe the clinical aspects of infection and touch on the important techniques for optimal investigation of this infection.
Helicobacter species methods and protocols. Introduction.
34268160
BACKGROUND Drug-eluting stent (DES) implantation is routine during coronary revascularization because DES significantly reduce rates of restenosis and target lesion revascularization compared with bare metal stent (BMS). However, available DES have limitations, such as late thrombosis because of delayed healing with poorer endothelialization and persistent local inflammation. Statins can inhibit cell proliferation, inflammation, and restore endothelial function. The present study evaluated the ability of stent-based cerivastatin delivery to reduce stent-induced inflammatory responses and adverse effects on endothelial function, and to inhibit neointimal hyperplasia in a porcine coronary model. METHODS AND RESULTS Pigs were randomized into groups in which the coronary arteries (9 pigs, 18 coronaries in each group) had either a cerivastatin-eluting stent (CES) or a BMS. All animals survived without any adverse effects. Inflammatory cell infiltration evaluated using scanning electron microscopy on day 3 after stenting was significantly decreased in the treated vessels (inflammation score: 1.15+/-0.12 vs 2.43+/-0.34, p<0.0001). At day 28, endothelial function with intracoronary infusion of bradykinin was preserved in both the CES and BMS groups. Volumetric intravascular ultrasound images revealed decreased intimal volume in the CES group (28.3+/-5.4 vs 75.9+/-4.2 mm3, p<0.0001). Histomorphometric analysis showed reduced neointimal area (1.74+/-0.45 vs 3.83+/-0.51 mm2, p<0.0001) in the CES group despite similar injury scores (1.77+/-0.30 vs 1.77+/-0.22, p=0.97). CONCLUSION In porcine coronary arteries CES significantly decreased neointimal hyperplasia with a decreased early inflammatory response and without endothelial dysfunction.
Effectiveness of statin-eluting stent on early inflammatory response and neointimal thickness in a porcine coronary model.
34287602
Intrahost genetic diversity was analysed in naturally infected mosquitoes and birds to determine whether West Nile virus (WNV) exists in nature as a quasispecies and to quantify selective pressures within and between hosts. WNV was sampled from ten infected birds and ten infected mosquito pools collected on Long Island, NY, USA, during the peak of the 2003 WNV transmission season. A 1938 nt fragment comprising the 3' 1159 nt of the WNV envelope (E) coding region and the 5' 779 nt of the non-structural protein 1 (NS1) coding region was amplified and cloned and 20 clones per specimen were sequenced. Results from this analysis demonstrate that WNV infections are derived from a genetically diverse population of genomes in nature. The mean nucleotide diversity was 0.016 % within individual specimens and the mean percentage of clones that differed from the consensus sequence was 19.5 %. WNV sequences in mosquitoes were significantly more genetically diverse than WNV in birds. No host-dependent bias for particular types of mutations was observed and estimates of genetic diversity did not differ significantly between E and NS1 coding sequences. Non-consensus clones obtained from two avian specimens had highly similar genetic signatures, providing preliminary evidence that WNV genetic diversity may be maintained throughout the enzootic transmission cycle, rather than arising independently during each infection. Evidence of purifying selection was obtained from both intra- and interhost WNV populations. Combined, these data support the observation that WNV populations may be structured as a quasispecies and document strong purifying natural selection in WNV populations.
Genetic variation in West Nile virus from naturally infected mosquitoes and birds suggests quasispecies structure and strong purifying selection.
34316341
The spatial patterns of IGF2 and H19 gene expression are strikingly similar during parts of human embryonic/fetal and early postnatal development. Notable exceptions were found with the ciliary anlage of the embryonic retina and the choroid plexus/leptomeninges, where transcripts from the IGF2 but not the H19 locus could be detected. Moreover, in contrast to the other tissue samples examined, the choroid plexus/leptomeninges expressed both parental IGF2 alleles. Whilst RNase protection analysis revealed a weak activity of the P1 promoter in the choroid plexus/leptomeninges, the P2, P3 and P4 promoters were all active wherever IGF2 was expressed. We discuss these observations with respect to a hypothesized coordinated control of the reciprocally imprinted and closely linked IGF2 and H19 loci.
Overlapping patterns of IGF2 and H19 expression during human development: biallelic IGF2 expression correlates with a lack of H19 expression.
34328964
The localization and synthesis of basic fibroblast growth factor (bFGF) in the rat carotid artery were investigated at times of chronic smooth muscle cell proliferation. Immunocytochemical staining showed the presence of bFGF in the uninjured arterial wall, and after balloon injury, this cellular staining was decreased. Western and northern blot analyses likewise showed that the amount of bFGF protein and mRNA decreased after injury. A neutralizing antibody to bFGF was administered 4 and 5 days after injury and was found to have no effect on intimal smooth muscle cell proliferation. These data suggest that an increase in the expression of bFGF is not necessary for chronic smooth muscle cell proliferation observed after balloon catheter injury and that bFGF is not the major mitogen responsible for intimal smooth muscle cell proliferation.
Intimal smooth muscle cell proliferation after balloon catheter injury. The role of basic fibroblast growth factor.
34338075
PURPOSE Anticoagulant prophylaxis in patients with central venous catheters is controversial. We performed a meta-analysis of randomized controlled trials of anticoagulant prophylaxis in patients with central venous catheters. METHODS MEDLINE and EMBASE were searched up to May 2006, supplemented by manual searches of conference proceedings and bibliographies. RESULTS Fifteen trials were included. Unfractionated heparin infusion, oral fixed low-dose vitamin K antagonist, and subcutaneous low-molecular-weight heparin were evaluated. For all catheter-associated deep vein thrombosis (symptomatic and asymptomatic combined), the summary relative risks ranged from 0.31 to 0.73 (all achieved statistical significance). For symptomatic deep vein thrombosis, the summary relative risks ranged from 0.28 to 0.72, but did not achieve statistical significance for any individual regimen. CONCLUSION Anticoagulant prophylaxis is effective for preventing all catheter-associated deep vein thrombosis in patients with central venous catheters. The effectiveness for preventing symptomatic venous thromboembolism, including pulmonary embolism, remains uncertain.
Prevention of central venous catheter-associated thrombosis: a meta-analysis.
34369306
BACKGROUND A double-blind RCT on the short-term efficacy of nicotine patches compared to placebo patches among Dutch adolescents was conducted. The findings demonstrated that nicotine patches are efficacious for smoking cessation at end-of-treatment; however, only in highly compliant participants. We tested whether the effects of NRT also held in 6- (T7) and 12-month (T8) follow-up assessments. METHODS Adolescents aged 12-18 years, who smoked at least seven cigarettes a day and who were motivated to quit smoking were recruited at school yards and randomly assigned to either a nicotine patch (n=182) or a placebo patch (n=180) condition according to a computer generated list. Participants (N=257, age: 16.7 ± 1.13 years) attended an information meeting followed by a 6- or 9-week treatment. Smoking cessation, compliance, and potential covariates were measured by means of online questionnaires. Smoking cessation at T8 was biochemically validated by saliva cotinine. RESULTS At T7, 8.1% and 5.7% of participants were abstinent in the nicotine and placebo patch groups, respectively. At T8, abstinence was 4.4% and 6.6%, respectively. Intention-to-treat analyses showed no significant effects of NRT on abstinence rates at T7 (OR=1.54, 95% CI=0.57, 4.16) and validated abstinence rates at T8 (OR=0.64, 95% CI=0.21, 1.93) neither after considering compliance nor after adjusting for covariates. CONCLUSIONS NRT fails in helping adolescents quit smoking at 6- and 12-month follow-ups. This finding suggests that a more intensive approach is needed to assist youngsters in their quit attempts.
Long-term efficacy of nicotine replacement therapy for smoking cessation in adolescents: a randomized controlled trial.
34378726
Early views of autoimmune disease cast IFNγ as a prototypic pro-inflammatory factor. It is now clear that IFNγ is capable of both pro- and anti-inflammatory activities with the functional outcome dependent on the physiological and pathological setting examined. Here, the major immune modulatory activities of IFNγ are reviewed and current evidence for the impact of IFNγ on pathology and regulation of several autoimmune diseases and disease models is summarized.
Interferon gamma in autoimmunity: A complicated player on a complex stage.
34386619
The Bacillus subtilis clpC operon is regulated by two stress induction pathways relying on either sigmaB or a class III stress induction mechanism acting at a sigmaA-like promoter. When the clpC operon was placed under the control of the isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible Pspac promoter, dramatic repression of the natural clpC promoters fused to a lacZ reporter gene was noticed after IPTG induction. This result strongly indicated negative regulation of the clpC operon by one of its gene products. Indeed, the negative regulator could be identified which is encoded by the first gene of the clpC operon, ctsR, containing a predicted helix-turn-helix DNA-binding motif. Deletion of ctsR abolished the negative regulation and resulted in high expression of both the clpC operon and the clpP gene under nonstressed conditions. Nevertheless, a further increase in clpC and clpP mRNA levels was observed after heat shock, even in the absence of sigmaB, suggesting a second induction mechanism at the vegetative promoter. Two-dimensional gel analysis and mRNA studies showed that the expression of other class III stress genes was at least partially influenced by the ctsR deletion. Studies with different clpC promoter fragments either fused to the reporter gene bgaB or used in gel mobility shift experiments with the purified CtsR protein revealed a possible target region where the repressor seemed to bind in vivo and in vitro. Our data demonstrate that the CtsR protein acts as a global repressor of the clpC operon, as well as other class III heat shock genes, by preventing unstressed transcription from either the sigmaB- or sigmaA-dependent promoter and might be inactivated or dissociate under inducing stress conditions.
The first gene of the Bacillus subtilis clpC operon, ctsR, encodes a negative regulator of its own operon and other class III heat shock genes.