bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration Host Factor (IHF) binds to the promoter region of the phtD operon involved in phaseolotoxin synthesis in P. syringaepv. phaseolicola NPS3121
Authors: Arvizu-Gómez Jackeline Lizzeta , Hernández-Morales Alejandro , Pastor-Palacios Guillermo , Brieba Luis G , Álvarez-Morales Ariel
Published: May 2011

Background

Pseudomonas syringae pv. phaseolicola, the causal agent of halo blight disease in beans, produces a toxin known as phaseolotoxin, in whose synthesis participate a group of genes organized within the genome in a region known as the "Pht cluster". This region, which is thought to have been acquired by horizontal gene transfer, includes 5 transcriptional units, two monocistronic (argK, phtL) and three polycistronic (phtA, phtD, phtM), whose expression is temperature dependent. So far, the regulatory mechanisms involved in phaseolotoxin synthesis have not been elucidated and the only well-established fact is the requirement of low temperatures for its synthesis. In this work, we searched for regulatory proteins that could be involved in phaseolotoxin synthesis, focusing on the regulation of the phtD operon.

Results

In this study we identified the global regulator IHF (Integration Host Factor), which binds to the promoter region of the phtD operon, exerting a negative effect on the expression of this operon. This is the first regulatory protein identified as part of the phaseolotoxin synthesis system. Our findings suggest that the Pht cluster was similarly regulated in the ancestral cluster by IHF or similar protein, and integrated into the global regulatory mechanism of P. syringae pv. phaseolicola, after the horizontal gene transfer event by using the host IHF protein.

Conclusion

This study identifies the IHF protein as one element involved in the regulation of phaseolotoxin synthesis in P. syringae pv. phaseolicola NPS3121 and provides new insights into the regulatory mechanisms involved in phaseolotoxin production.
The burden of physical activity on type 2 diabetes public healthcare expenditures among adults: a retrospective study
Authors: Codogno Jamile S , Fernandes Rômulo A , Sarti Flávia M , Freitas Júnior Ismael F , Monteiro Henrique L
Published: May 2011

Background

Determinants of public healthcare expenditures in type 2 diabetics are not well investigated in developing nations and, therefore, it is not clear if higher physical activity decreases healthcare costs. The purpose of this study was to analyze the relationship between physical activity and the expenditures in public healthcare on type 2 diabetes mellitus treatment.

Methods

Cross-sectional study carried out in Brazil. A total of 121 type 2 diabetics attended to in two Basic Healthcare Units were evaluated. Public healthcare expenditures in the last year were estimated using a specific standard table. Also evaluated were: socio-demographic variables; chronological age; exogenous insulin use; smoking habits; fasting glucose test; diabetic neuropathy and anthropometric measures. Habitual physical activity was assessed by questionnaire.

Results

Age (r = 0.20; p = 0.023), body mass index (r = 0.33; p = 0.001) and waist-to-hip ratio (r = 0.20; p = 0.025) were positively related to expenditures on medication for the treatment of diseases other than diabetes. Insulin use was associated with increased expenditures. Higher physical activity was associated with lower expenditure, provided medication for treatment of diseases other than diabetes (OR = 0.19; p = 0.007) and medical consultations (OR = 0.26; p = 0.029).

Conclusions

Type 2 diabetics with higher enrollment in physical activity presented consistently lower healthcare expenditures for the public healthcare system.
Delay in diagnosis of muscle disorders depends on the subspecialty of the initially consulted physician
Authors: Spuler Simone , Stroux Andrea , Kuschel Franziska , Kuhlmey Adelheid , Kendel Friederike
Published: May 2011

Background

New therapeutic strategies in muscular dystrophies will make a difference in prognosis only if they are begun early in the course of the disease. Therefore, we investigated factors that influence the time to diagnosis in muscle dystrophy patients.

Methods

A sample of 101 patients (mean age 49 years; range 19-80; 44% women) with diagnosed muscle dystrophies from neurological practices and the neuromuscular specialty clinic in Berlin, Germany, was invited to participate. Time from first consultation to diagnosis, subspecialty of physician, and sociodemographic data were assessed with self-report questionnaires. The association between time to diagnosis and potential predictors (subspecialty of initially consulted physician, diagnoses, gender, and age at onset) was modeled with linear regression analysis.

Results

The mean time span between first health-care contact and diagnosis was 4.3 years (median 1). The diagnostic delay was significantly longer if patients were initially seen by a non-neurological specialist compared to a general practitioner (5.2 vs. 3.5 years, p = 0.047). Other factors that were independently associated with diagnostic delay were female gender and inherited muscle disease.

Conclusion

Action to improve clinical awareness of muscle diseases in non-neurological specialists is needed.
Assessment of psychosocial functioning and its risk factors in children with pectus excavatum
Authors: Ji Yi , Liu Wenying , Chen Siyuan , Xu Bing , Tang Yunman , Wang Xuejun , Yang Gang , Cao Liming
Published: May 2011

Background

Psychosocial functioning is poor in patients with pectus excavatum (PE). However, a comprehensive understanding of this issue does not exist. The aim of this study was to assess the severity of psychosocial problems as associated with PE, as well as to identify its risk factors.

Methods

A comparative study was performed at the Sichuan Academy of Medical Sciences/Sichuan Provincial People's Hospital in Chengdu, China. Patients age 6 to 16 who admitted to the outpatient department for the evaluation or treatment for PE were included in the study. In addition to parental reports of child psychosocial problems on the Achenbach Child Behavior Checklist (CBCL), parents also filled in other structured questionnaires, including socio-demographic variables, patients' medical and psychological characteristics. The severity of malformation was assessed by CT scan. For comparison, an age- and gender- matched control group was recruited from the general population. The socio-demographic and scores on CBCL were compared between patients and control subjects. Univariate and multivariate analysis were performed to examine risk factors for psychosocial problems in patients.

Results

No statistically significant differences were found with respect to social-demographic variables between children with PE and control subjects. Compared with control subjects, children with PE displayed higher prevalence of psychosocial problems in the different scales of the CBCL questionnaire such as 'withdraw', 'anxious-depressed', 'social problems' and 'total problems'. Both univariate and multivariate analyses suggested that age, severity of malformation, and being teased about PE were significantly associated with patients' psychosocial problems.

Conclusions

The information derived from this study supports the opinion that children with PE have more psychosocial problems than children from the general population. Multiple medical and psychosocial factors were associated with patients' impairment of psychosocial functioning.
CCR9-CCL25 interactions promote cisplatin resistance in breast cancer cell through Akt activation in a PI3K-dependent and FAK-independent fashion
Authors: Johnson-Holiday Crystal , Singh Rajesh , Johnson Erica L , Grizzle William E , Lillard James W , Singh Shailesh
Published: May 2011

Background

Chemotherapy heavily relies on apoptosis to kill breast cancer (BrCa) cells. Many breast tumors respond to chemotherapy, but cells that survive this initial response gain resistance to subsequent treatments. This leads to aggressive cell variants with an enhanced ability to migrate, invade and survive at secondary sites. Metastasis and chemoresistance are responsible for most cancer-related deaths; hence, therapies designed to minimize both are greatly needed. We have recently shown that CCR9-CCL25 interactions promote BrCa cell migration and invasion, while others have shown that this axis play important role in T cell survival. In this study we have shown potential role of CCR9-CCL25 axis in breast cancer cell survival and therapeutic efficacy of cisplatin.

Methods

Bromodeoxyuridine (BrdU) incorporation, Vybrant apoptosis and TUNEL assays were performed to ascertain the role of CCR9-CCL25 axis in cisplatin-induced apoptosis of BrCa cells. Fast Activated Cell-based ELISA (FACE) assay was used to quantify In situ activation of PI3Kp85, AktSer473, GSK-3βSer9 and FKHRThr24 in breast cancer cells with or without cisplatin treatment in presence or absence of CCL25.

Results

CCR9-CCL25 axis provides survival advantage to BrCa cells and inhibits cisplatin-induced apoptosis in a PI3K-dependent and focal adhesion kinase (FAK)-independent fashion. Furthermore, CCR9-CCL25 axis activates cell-survival signals through Akt and subsequent glycogen synthase kinase-3 beta (GSK-3β) and forkhead in human rhabdomyosarcoma (FKHR) inactivation. These results show that CCR9-CCL25 axis play important role in BrCa cell survival and low chemotherapeutic efficacy of cisplatin primarily through PI3K/Akt dependent fashion.
Cancer stem cell subsets and their relationships
Authors: Liu Hai-Guang , Chen Chong , Yang Han , Pan Yi-Fei , Zhang Xiao-Hua
Published: May 2011

Emerging evidence suggests that cancer stem cells account for the initiation and progression of cancer. While many types of cancer stem cells with specific markers have been isolated and identified, a variety of differences among them began to be appreciated. Cancer stem cells are hierarchical populations that consist of precancerous stem cells, primary cancer stem cells, migrating cancer stem cells and chemoradioresistant cancer stem cells, playing different roles in cancer initiation and progression. Here we propose a new concept "horizontal hierarchy of cancer stem cells" to distinguish them from vertical hierarchy cancer stem cells, cancer transient-amplifying cells and cancer differentiated cells, and summarize our current understanding of these subsets of cancer stem cells with the aim to open up novel therapeutic strategies for cancer based on this understanding.
Shrinking of Solid-state Nanopores by Direct Thermal Heating
Authors: Asghar Waseem , Ilyas Azhar , Billo Joseph Anthony , Iqbal Samir Muzaffar
Published: May 2011

Solid-state nanopores have emerged as useful single-molecule sensors for DNA and proteins. A novel and simple technique for solid-state nanopore fabrication is reported here. The process involves direct thermal heating of 100 to 300 nm nanopores, made by focused ion beam (FIB) milling in free-standing membranes. Direct heating results in shrinking of the silicon dioxide nanopores. The free-standing silicon dioxide membrane is softened and adatoms diffuse to a lower surface free energy. The model predicts the dynamics of the shrinking process as validated by experiments. The method described herein, can process many samples at one time. The inbuilt stress in the oxide film is also reduced due to annealing. The surface composition of the pore walls remains the same during the shrinking process. The linear shrinkage rate gives a reproducible way to control the diameter of a pore with nanometer precision.
EphA4 expression promotes network activity and spine maturation in cortical neuronal cultures
Authors: Clifford Meredith A , Kanwal Jessleen K , Dzakpasu Rhonda , Donoghue Maria J
Published: May 2011

Background

Neurons form specific connections with targets via synapses and patterns of synaptic connectivity dictate neural function. During development, intrinsic neuronal specification and environmental factors guide both initial formation of synapses and strength of resulting connections. Once synapses form, non-evoked, spontaneous activity serves to modulate connections, strengthening some and eliminating others. Molecules that mediate intercellular communication are particularly important in synaptic refinement. Here, we characterize the influences of EphA4, a transmembrane signaling molecule, on neural connectivity.

Results

Using multi-electrode array analysis on in vitro cultures, we confirmed that cortical neurons mature and generate spontaneous circuit activity as cells differentiate, with activity growing both stronger and more patterned over time. When EphA4 was over-expressed in a subset of neurons in these cultures, network activity was enhanced: bursts were longer and were composed of more spikes than in control-transfected cultures. To characterize the cellular basis of this effect, dendritic spines, the major excitatory input site on neurons, were examined on transfected neurons in vitro. Strikingly, while spine number and density were similar between conditions, cortical neurons with elevated levels of EphA4 had significantly more mature spines, fewer immature spines, and elevated colocalization with a mature synaptic marker.

Conclusions

These results demonstrate that experimental elevation of EphA4 promotes network activity in vitro, supporting spine maturation, producing more functional synaptic pairings, and promoting more active circuitry.
Rostral growth of commissural axons requires the cell adhesion molecule MDGA2
Authors: Joset Pascal , Wacker Andrin , Babey Régis , Ingold Esther A , Andermatt Irwin , Stoeckli Esther T , Gesemann Matthias
Published: May 2011

Background

Long-distance axonal growth relies on the precise interplay of guidance cues and cell adhesion molecules. While guidance cues provide positional and directional information for the advancing growth cone, cell adhesion molecules are essential in enabling axonal advancement. Such a dependence on adhesion as well as guidance molecules can be well observed in dorsal commissural interneurons, which follow a highly stereotypical growth and guidance pattern. The mechanisms and molecules involved in the attraction and outgrowth towards the ventral midline, the axon crossing towards the contralateral side, the rostral turning after midline crossing as well as the guidance along the longitudinal axis have been intensely studied. However, little is known about molecules that provide the basis for commissural axon growth along the anterior-posterior axis.

Results

MDGA2, a recently discovered cell adhesion molecule of the IgCAM superfamily, is highly expressed in dorsolaterally located (dI1) spinal interneurons. Functional studies inactivating MDGA2 by RNA interference (RNAi) or function-blocking antibodies demonstrate that either treatment results in a lack of commissural axon growth along the longitudinal axis. Moreover, results from RNAi experiments targeting the contralateral side together with binding studies suggest that homophilic MDGA2 interactions between ipsilaterally projecting axons and post-crossing commissural axons may be the basis of axonal growth along the longitudinal axis.

Conclusions

Directed axonal growth of dorsal commissural interneurons requires an elaborate mixture of instructive (guidance) and permissive (outgrowth supporting) molecules. While Wnt and Sonic hedgehog (Shh) signalling pathways have been shown to specify the growth direction of post-crossing commissural axons, our study now provides evidence that homophilic MDGA2 interactions are essential for axonal extension along the longitudinal axis. Interestingly, so far each part of the complex axonal trajectory of commissural axons uses its own set of guidance and growth-promoting molecules, possibly explaining why such a high number of molecules influencing the growth pattern of commissural interneurons has been identified.
Seroprevalence of Toxoplasma gondii infection in pet dogs in Lanzhou, Northwest China
Authors: Wu Song-Ming , Huang Si-Yang , Fu Bao-Quan , Liu Guang-Yuan , Chen Jia-Xu , Chen Mu-Xin , Yuan Zi-Guo , Zhou Dong-Hui , Weng Ya-Biao , Zhu Xing-Quan , Ye De-He
Published: May 2011

Background

In recent years, surveys of Toxoplasma gondii infection in dogs have been reported worldwide, including China. However, little is known about the prevalence of T. gondii in pet dogs in Northwest China. In the present study, the prevalence of T. gondii in pet dogs in Lanzhou, China was investigated using the modified agglutination test (MAT).

Results

In this survey, antibodies to T. gondii were found in 28 of 259 (10.81%) pet dogs, with MAT titers of 1:20 in 14 dogs, 1:40 in nine, 1:80 in four, and 1:160 or higher in one dog. The prevalence ranged from 6.67% to 16.67% among dogs of different ages, with low rates in young pet dogs, and high rates in older pet dogs. The seroprevalence in dogs >3 years old was higher than that in dogs ≤1 years old, but the difference was not statistically significant (P > 0.05). The seroprevalence in male dogs was 12.50% (17 of 136), and in female dogs it was 8.94% (11 of 123), but the difference was not statistically significant (P > 0.05).

Conclusions

A high prevalence of T. gondii infection was found in pet dogs in Lanzhou, Northwest China, which has implications for public health in this region. In order to reduce the risk of exposure to T. gondii, further measures and essential control strategies should be carried out rationally in this region.
Differential DNA extraction of challenging simulated sexual-assault samples: a Swiss collaborative study
Authors: Vuichard Séverine , Borer Urs , Bottinelli Michel , Cossu Christian , Malik Naseem , Meier Verena , Gehrig Christian , Sulzer Andrea , Morerod Marie-Laure , Castella Vincent
Published: May 2011

In sexual-assault cases, autosomal DNA analysis of gynecological swabs is a challenge, as the presence of a large quantity of female material may prevent detection of the male DNA. A solution to this problem is differential DNA extraction, but there is no established best practice for this. We decided to test the efficacy of a number of different protocols on simulated casework samples. Four difficult samples were sent to the nine Swiss laboratories active in forensic genetics. In each laboratory, staff used their routine protocols to separate the epithelial-cell fraction, enriched with the non-sperm DNA, from the sperm fraction. DNA extracts were then sent to the organizing laboratory for analysis. Estimates of male:female DNA ratio without differential DNA extraction ranged from 1:38 to 1:339, depending on the semen used to prepare the samples. After differential DNA extraction, most of the ratios ranged from 1:12 to 9:1, allowing detection of the male DNA. Compared with direct DNA extraction, cell separation resulted in losses of 94-98% of the male DNA. As expected, more male DNA was generally present in the sperm than in the epithelial-cell fraction. However, for about 30% of the samples, the reverse trend was seen. The recovery of male and female DNA was highly variable, depending on the laboratory involved. An experimental design similar to the one used in this study may be of assistance for local protocol testing and improvement.
Genetic variation and population structure of Sudanese populations as indicated by 15 Identifiler sequence-tagged repeat (STR) loci
Authors: Babiker Hiba MA , Schlebusch Carina M , Hassan Hisham Y , Jakobsson Mattias
Published: May 2011

Background

There is substantial ethnic, cultural and linguistic diversity among the people living in east Africa, Sudan and the Nile Valley. The region around the Nile Valley has a long history of succession of different groups, coupled with demographic and migration events, potentially leading to genetic structure among humans in the region.

Result

We report the genotypes of the 15 Identifiler microsatellite markers for 498 individuals from 18 Sudanese populations representing different ethnic and linguistic groups. The combined power of exclusion (PE) was 0.9999981, and the combined match probability was 1 in 7.4 × 1017. The genotype data from the Sudanese populations was combined with previously published genotype data from Egypt, Somalia and the Karamoja population from Uganda. The Somali population was found to be genetically distinct from the other northeast African populations. Individuals from northern Sudan clustered together with those from Egypt, and individuals from southern Sudan clustered with those from the Karamoja population. The similarity of the Nubian and Egyptian populations suggest that migration, potentially bidirectional, occurred along the Nile river Valley, which is consistent with the historical evidence for long-term interactions between Egypt and Nubia.

Conclusion

We show that despite the levels of population structure in Sudan, standard forensic summary statistics are robust tools for personal identification and parentage analysis in Sudan. Although some patterns of population structure can be revealed with 15 microsatellites, a much larger set of genetic markers is needed to detect fine-scale population structure in east Africa and the Nile Valley.
Ryanodine receptors
Authors: Capes EMichelle , Loaiza Randall , Valdivia Héctor H
Published: May 2011

Excitation-contraction coupling involves the faithful conversion of electrical stimuli to mechanical shortening in striated muscle cells, enabled by the ubiquitous second messenger, calcium. Crucial to this process are ryanodine receptors (RyRs), the sentinels of massive intracellular calcium stores contained within the sarcoplasmic reticulum. In response to sarcolemmal depolarization, RyRs release calcium into the cytosol, facilitating mobilization of the myofilaments and enabling cell contraction. In order for the cells to relax, calcium must be rapidly resequestered or extruded from the cytosol. The sustainability of this cycle is crucially dependent upon precise regulation of RyRs by numerous cytosolic metabolites and by proteins within the lumen of the sarcoplasmic reticulum and those directly associated with the receptors in a macromolecular complex. In addition to providing the majority of the calcium necessary for contraction of cardiac and skeletal muscle, RyRs act as molecular switchboards that integrate a multitude of cytosolic signals such as dynamic and steady calcium fluctuations, β-adrenergic stimulation (phosphorylation), nitrosylation and metabolic states, and transduce these signals to the channel pore to release appropriate amounts of calcium. Indeed, dysregulation of calcium release via RyRs is associated with life-threatening diseases in both skeletal and cardiac muscle. In this paper, we briefly review some of the most outstanding structural and functional attributes of RyRs and their mechanism of regulation. Further, we address pathogenic RyR dysfunction implicated in cardiovascular disease and skeletal myopathies.
Integrated genomics and proteomics of the Torpedo californica electric organ: concordance with the mammalian neuromuscular junction
Authors: Mate Suzanne E. , Brown Kristy J. , Hoffman Eric P.
Published: May 2011

Background

During development, the branchial mesoderm ofTorpedo californicatransdifferentiates into an electric organ capable of generating high voltage discharges to stun fish. The organ contains a high density of cholinergic synapses and has served as a biochemical model for the membrane specialization of myofibers, the neuromuscular junction (NMJ). We studied the genome and proteome of the electric organ to gain insight into its composition, to determine if there is concordance with skeletal muscle and the NMJ, and to identify novel synaptic proteins.

Results

Of 435 proteins identified, 300 mapped toTorpedocDNA sequences with ≥2 peptides. We identified 14 uncharacterized proteins in the electric organ that are known to play a role in acetylcholine receptor clustering or signal transduction. In addition, two human open reading frames, C1orf123 and C6orf130, showed high sequence similarity to electric organ proteins. Our profile lists several proteins that are highly expressed in skeletal muscle or are muscle specific. Synaptic proteins such as acetylcholinesterase, acetylcholine receptor subunits, and rapsyn were present in the electric organ proteome but absent in the skeletal muscle proteome.

Conclusions

Our integrated genomic and proteomic analysis supports research describing a muscle-like profile of the organ. We show that it is a repository of NMJ proteins but we present limitations on its use as a comprehensive model of the NMJ. Finally, we identified several proteins that may become candidates for signaling proteins not previously characterized as components of the NMJ.
Aberrant repair and fibrosis development in skeletal muscle
Authors: Mann Christopher J , Perdiguero Eusebio , Kharraz Yacine , Aguilar Susana , Pessina Patrizia , Serrano Antonio L , Muñoz-Cánoves Pura
Published: May 2011

The repair process of damaged tissue involves the coordinated activities of several cell types in response to local and systemic signals. Following acute tissue injury, infiltrating inflammatory cells and resident stem cells orchestrate their activities to restore tissue homeostasis. However, during chronic tissue damage, such as in muscular dystrophies, the inflammatory-cell infiltration and fibroblast activation persists, while the reparative capacity of stem cells (satellite cells) is attenuated. Abnormal dystrophic muscle repair and its end stage, fibrosis, represent the final common pathway of virtually all chronic neurodegenerative muscular diseases. As our understanding of the pathogenesis of muscle fibrosis has progressed, it has become evident that the muscle provides a useful model for the regulation of tissue repair by the local microenvironment, showing interplay among muscle-specific stem cells, inflammatory cells, fibroblasts and extracellular matrix components of the mammalian wound-healing response. This article reviews the emerging findings of the mechanisms that underlie normal versus aberrant muscle-tissue repair.
Prenatal Glucocorticoid Overexposure Causes Permanent Increases in Renal Erythropoietin Expression and Red Blood Cell Mass in the Rat Offspring
Authors: Tang Justin I. , Seckl Jonathan R. , Nyirenda Moffat J.
Published: May 2011

Glucocorticoids promote maturation of fetal systems, including erythropoiesis, in preparation for extrauterine life. However, recent studies have shown that prenatal glucocorticoid excess can cause long-term deleterious cardiometabolic and other consequences to the offspring. Here, we examined the effect of prenatal treatment with the synthetic glucocorticoid dexamethasone (DEX) during the last week of gestation on red blood cell (RBC) mass in the rat offspring. DEX-treated offspring at 9 months of age had significantly higher RBC count (9.4 ± 0.1 vs. 8.8 ± 0.2 × 1012 liter; P = 0.02), hematocrit (50.0 ± 0.5 vs. 46.7 ± 0.7%; P=0.004), hemoglobin (17.3 ± 0.2 vs. 16.2 ± 0.2 g/dl; P = 0.02) and number of reticulocytes (258.2 ± 8.8 vs. 235.7 ± 5.6 × 109 liter; P = 0.04), compared with offspring of vehicle-treated control pregnancies. White blood cells and platelets were unaltered. Renal mRNA expression and plasma concentrations of erythropoietin, the main regulator of erythropoiesis, were increased by nearly 100% in both newborn and adult DEX-treated rats (P < 0.01). This increase was accompanied by marked elevation in renal expression of hepatocyte nuclear factor 4α mRNA, whereas other erythropoietin-regulating transcription factors, such as hypoxia-inducible factor 1, hypoxia-inducible factor 2, and GATA2 were unchanged. These data indicate that RBC mass can be programmed by prenatal glucocorticoid excess, and if extrapolatable to humans, provide a novel mechanism for fetal origins of polycythemia and its associated complications.
Toll-Like Receptor-Initiated Testicular Innate Immune Responses in Mouse Leydig Cells
Authors: Shang Tao , Zhang Xiaoyan , Wang Tao , Sun Bing , Deng Tingting , Han Daishu
Published: May 2011

The testis is an immunoprivileged site, where the local cell-initiated testicular innate immune responses play a crucial role in defense against microbial infections. Mechanisms modulating the testicular cell-built defense system remain to be clarified. In this article, we demonstrate that Leydig cells, a major cell population in the testicular interstitium, initiate innate immunity through the activation of Toll-like receptors (TLRs). Several TLRs are expressed in mouse Leydig cells; among these, TLR3 and TLR4 are expressed at relatively high levels compared with other TLR members. Both TLR3 and TLR4 can be activated by their agonists (polyinosinic:polycytidylic acid and lipopolysaccharide) in Leydig cells and subsequently induce the production of inflammatory factors, such as IL-1β, IL-6, TNF-α, and type 1 interferons (IFN) (IFN-α and IFN-β). Notably, the activation of TLR3 and TLR4 suppresses steroidogenesis by Leydig cells. Further, we provide evidence that Axl and Mer receptor tyrosine kinases are expressed in Leydig cells and regulate TLR-mediated innate immune responses negatively. Data presented here describe a novel function of Leydig cells in eliciting testicular innate immune responses that should contribute to the protection of the testis from microbial infections.
Estrogen Protection in Friedreich's Ataxia Skin Fibroblasts
Authors: Richardson Timothy E. , Yang Shao-Hua , Wen Yi , Simpkins James W.
Published: May 2011

Estrogens have been shown to have protective effects on a wide range of cell types and animal models for many neurodegenerative diseases. The present study demonstrates the cytoprotective effects of 17β-estradiol (E2) and estrogen-like compounds in an in vitro model of Friedreich's ataxia (FRDA) using human donor FRDA skin fibroblasts. FRDA fibroblasts are extremely sensitive to free radical damage and oxidative stress, produced here using l-buthionine (S,R)-sulfoximine to inhibit de novo glutathione synthesis. We have shown that the protective effect of E2 in the face of l-buthionine (S,R)-sulfoximine -induced oxidative stress is independent of estrogen receptor-α, estrogen receptor-β or G protein-coupled receptor 30 as shown by the inability of either ICI 182,780 or G15 to inhibit the E2-mediated protection. These cytoprotective effects appear to be dependent on antioxidant properties and the phenolic structure of estradiol as demonstrated by the observation that all phenolic compounds tested were protective, whereas all nonphenolic compounds were inactive, and the observation that the phenolic compounds reduced the levels of reactive oxygen species, whereas the nonphenolic compounds did not. These data show for the first time that phenolic E2-like compounds are potent protectors against oxidative stress-induced cell death in FRDA fibroblasts and are possible candidate drugs for the treatment and prevention of FRDA symptoms.
Desire and Genre in The Female Quixote
Authors: Watson Zak
Published: May 2011

This article proposes a new account of the interplay of genre and desire in Charlotte Lennox's The Female Quixote. It claims that Arabella's education, her transition from the rules of romance to those of the novel, consists of her being drawn into the circuit of desire that defines her contemporary world. By reading the movement to the novel as one into desire (instead of away from it, as many critics have claimed), I suggest that Lennox reverses the terms of her contemporary critical discourse on realistic and fantastic fiction; the author uses the romance, not the novel, to teach her readers a lesson about the dangers of interpreting desire according to the rules of realistic writing. Instead of issuing a late warning about the dangers of romance reading, Lennox issues an early warning about the possibility that novel reading might coarsen sensibilities by reducing desire to measurable goals. She urges readers to see the difference between the romance and the novel not in terms of their content but in terms of generic assumptions about how desire works; novels rely on the transparency of desire to construct realistic characters and narrative arcs, while romances rely on the mystery of desire and deny the satisfying conclusion of revealing its putative truth. The Female Quixote constructs a space that escapes the instrumental understanding of desire that subtends realistic writing and reminds readers and critics to think twice before interpreting desire according to its rules.
George Eliot and the Rise of the Language of Expertise
Authors: Murtagh Joseph
Published: May 2011

“George Eliot and the Rise of the Language of Expertise” examines the impact of professionalization on the novels of George Eliot. By vastly increasing the scope and complexity of nineteenth-century occupations, professionalization created certain challenges for novelists, not the least of which was establishing credibility with readers who often had more intimate knowledge of specialized occupations than novelists did themselves. As a result, Victorian novelists spent far more time researching the work lives of their characters than had novelists of a previous generation, a sign that professional specialization had opened up a gap between novelists and the reading public. In particular, George Eliot established her professional credibility as an author by incorporating vocabularies into her novels that carried an aura of prestige thanks to the rise in prominence of specialized expertise. By sympathetically rendering the linguistic peculiarities of nineteenth-century professionals, Eliot positioned herself as a social mediator who could bridge the gap between the reading public and an increasingly sophisticated division of labor, thus inaugurating a trend in the novel that has continued to the present day.
Russell on Substitutivity and the Abandonment of Propositions
Authors: Proops Ian
Published: May 2011

One of the main arguments Russell offers for the Theory of Descriptions in “On Denoting” is that it can be used to solve a puzzle about substitutivity. This article argues that, owing to a widespread mischaracterization of the substitutivity principle Russell means to be defending, neither the puzzle itself nor Russell's solution to it have been well understood. The principle Russell seeks to defend concerns not the substitution of expressions in a sentence but rather the substitution of propositional constituents in a Russellian proposition. This article further argues that Russell's solution requires him to adopt certain substantive views about the nature of the referents of what are usually called “logically proper names.” In particular, Russell's solution will work only if the referents of such names are given to one who understands them in a manner that is entirely “aspect-free.” Russell's notion of acquaintance, since it fits this bill, is therefore motivated by his solution to the puzzle, as is his choice of sense-data to be the referents of genuine Russellian names of particulars. Finally, the article argues that since a version of the George IV puzzle arises for propositions, Russell's solution commits him to regarding some instances of sentences as incomplete symbols and to denying that we have acquaintance with propositions. This in turn leads Russell in Principia Mathematica to adopt the Multiple Relation Theory of Judgment, and thus to embrace agnosticism about propositions. His further move to the stronger position of full eliminativism concerning propositions is motivated only by his late-in-the-day espousal of the Principle of Sufficient Reason.
On Two Theories of Substance in Leibniz: Critical Notice of Daniel Garber,Leibniz: Body, Substance, Monad
Authors: Levey Samuel
Published: May 2011

The article is a critical notice of Daniel Garber, Leibniz: Body, Substance, Monad. Garber presents a developmental reading of Leibniz's metaphysics that focuses on Leibniz's evolving analysis of body and force as the key to his account of substance. Garber claims that Leibniz shifts from an early theory of body to a theory of corporeal substance in his middle years, and only develops a theory of monads in his later writings—and that even then Leibniz looks not to abandon the scheme of corporeal substances but to reconcile it with that of monads. The present article considers several challenges to Garber's interpretation, questioning, among other things, Garber's claims about development and Garber's account of Leibniz's primary arguments for the theory of monads. The article concludes that while crucial elements of the standard interpretation of Leibniz as an idealist can be defended against Garber's critique, the original traditional view that takes the theory of monads as the first and most fundamental principle of Leibniz's metaphysics is no longer sustainable.
Whom Do Physicians Work For? An Analysis of Dual Practice in the Health Sector
Authors: García-Prado Ariadna , González Paula
Published: May 2011

This article presents a thorough analysis of dual practice among physicians who work in both the public and private sectors. A conceptual framework is presented to help the reader understand dual practice and the contexts where it takes place. The article reviews the existing theoretical and empirical literature on this form of dual practice among physicians. It analyzes the extent of this phenomenon, the underlying factors that motivate physicians to engage in dual practice, and the main implications of their decision to do so. It also examines and discusses current policies that address dual practice. In this regard, the article provides some qualified support for the use of “rewarding” policies to retain physicians in the public sectors of more developed countries, while “limiting” policies are recommended for developing countries — with the caveat that the policies should be accompanied by the strengthening of institutional and contracting environments. The article highlights the lack of quality evaluative evidence regarding the consequences of dual practice on the delivery of health care services. It concludes that the overall impact of dual practice remains an open question that warrants more attention from researchers and policy makers alike.
Wild-type Drosophila melanogaster as an alternative model system for investigating the pathogenicity of Candida albicans
Authors: Glittenberg Marcus T. , Silas Sukrit , MacCallum Donna M. , Gow Neil A. R. , Ligoxygakis Petros
Published: May 2011

Candida spp. are opportunistic pathogens in humans, and their systemic infections display upwards of 30% mortality in immunocompromised patients. Current mammalian model systems have certain disadvantages in that obtaining results is time consuming owing to the relatively long life spans and these results have low statistical resolution because sample sizes are usually small. We have therefore evaluated the potential of Drosophila melanogaster as an additional model system with which to dissect the host-pathogen interactions that occur during Candida albicans systemic infection. To do this, we monitored the survival of wild-type flies infected with various C. albicans clinical isolates that were previously ranked for murine virulence. From our lifetime data we computed two metrics of virulence for each isolate. These correlated significantly with murine survival, and were also used to group the isolates, and this grouping made relevant predictions regarding their murine virulence. Notably, differences in virulence were not predictably resolvable using immune-deficient spz−/− flies, suggesting that Toll signalling might actually be required to predictably differentiate virulence. Our analysis reveals wild-type D. melanogaster as a sensitive and relevant model system; one that offers immense genetic tractability (having an extensive RNA interference library that enables tissue-specific gene silencing), and that is easy to manipulate and culture. Undoubtedly, it will prove to be a valuable addition to the model systems currently used to study C. albicans infection.
Pathogen and host factors are needed to provoke a systemic host response to gastrointestinal infection ofDrosophilalarvae byCandida albicans
Authors: Glittenberg Marcus T. , Kounatidis Ilias , Christensen David , Kostov Magali , Kimber Sandra , Roberts Ian , Ligoxygakis Petros
Published: May 2011

Candida albicans systemic dissemination in immunocompromised patients is thought to develop from initial gastrointestinal (GI) colonisation. It is unclear what components of the innate immune system are necessary for preventing C. albicans dissemination from the GI tract, but studies in mice have indicated that both neutropenia and GI mucosal damage are crucial for allowing widespread invasive C. albicans disease. Mouse models, however, provide limited applicability to genome-wide screens for pathogen or host factors – factors that might influence systemic dissemination following GI colonisation. For this reason we developed a Drosophila model to study intestinal infection by Candida. We found that commensal flora aided host survival following GI infection. Candida provoked extensive JNK-mediated death of gut cells and induced antimicrobial peptide expression in the fat body. From the side of the host, nitric oxide and blood cells influenced systemic antimicrobial responses. The secretion of SAP4 and SAP6 (secreted aspartyl proteases) from Candida was also essential for activating systemic Toll-dependent immunity.
VEGF-mediated PI3K class IA and PKC signaling in cardiomyogenesis and vasculogenesis of mouse embryonic stem cells
Authors: Bekhite Mohamed M. , Finkensieper Andreas , Binas Stephanie , Müller Jörg , Wetzker Reinhard , Figulla Hans-Reiner , Sauer Heinrich , Wartenberg Maria
Published: May 2011

VEGF-, phosphoinositide 3-kinase (PI3K)- and protein kinase C (PKC)-regulated signaling in cardiac and vascular differentiation was investigated in mouse ES cells and in ES cell-derived Flk-1+ cardiovascular progenitor cells. Inhibition of PI3K by wortmannin and LY294002, disruption of PI3K catalytic subunits p110α and p110δ using short hairpin RNA (shRNA), or inhibition of p110α with compound 15e and of p110δ with IC-87114 impaired cardiac and vascular differentiation. By contrast, TGX-221, an inhibitor of p110β, and shRNA knockdown of p110β were without significant effects. Antagonists of the PKC family, i.e. bisindolylmaleimide-1 (BIM-1), GÖ 6976 (targeting PKCα/βII) and rottlerin (targeting PKCδ) abolished vasculogenesis, but not cardiomyogenesis. Inhibition of Akt blunted cardiac as well as vascular differentiation. VEGF induced phosphorylation of PKCα/βII and PKCδ but not PKCζ. This was abolished by PI3K inhibitors and the VEGFR-2 antagonist SU5614. Furthermore, phosphorylation of Akt and phosphoinositide-dependent kinase-1 (PDK1) was blunted upon inhibition of PI3K, but not upon inhibition of PKC by BIM-1, suggesting that activation of Akt and PDK1 by VEGF required PI3K but not PKC. In summary, we demonstrate that PI3K catalytic subunits p110α and p110δ are central to cardiovasculogenesis of ES cells. Akt downstream of PI3K is involved in both cardiomyogenesis and vasculogenesis, whereas PKC is involved only in vasculogenesis.
Ezrin is required for efficient Rap1-induced cell spreading
Authors: Ross Sarah H. , Post Anneke , Raaijmakers Judith H. , Verlaan Ingrid , Gloerich Martijn , Bos Johannes L.
Published: May 2011

The Rap family of small GTPases regulate the adhesion of cells to extracellular matrices. Several Rap-binding proteins have been shown to function as effectors that mediate Rap-induced adhesion. However, little is known regarding the relationships between these effectors, or about other proteins that are downstream of or act in parallel to the effectors. To establish whether an array of effectors was required for Rap-induced cell adhesion and spreading, and to find new components involved in Rap-signal transduction, we performed a small-scale siRNA screen in A549 lung epithelial cells. Of the Rap effectors tested, only Radil blocked Rap-induced spreading. Additionally, we identified a novel role for Ezrin downstream of Rap1. Ezrin was necessary for Rap-induced cell spreading, but not Rap-induced cell adhesion or basal adhesion processes. Furthermore, Ezrin depletion inhibited Rap-induced cell spreading in several cell lines, including primary human umbilical vein endothelial cells. Interestingly, Radixin and Moesin, two proteins with high homology to Ezrin, are not required for Rap-induced cell spreading and cannot compensate for loss of Ezrin to rescue Rap-induced cell spreading. Here, we present a novel function for Ezrin in Rap1-induced cell spreading and evidence of a non-redundant role of an ERM family member.
A pilot study: microbiological conditions of the oral cavity in minipigs for peri-implantitis models
Authors: Becker Stephan T , Dörfer Christof , Graetz Christian , De Buhr Wiebke , Wiltfang Jörg , Podschun Rainer
Published: May 2011

As peri-implantitis is an emerging problem, the development of validated animal models is mandatory. The aim of this pilot study was to provide a first step in describing the normal oral flora of minipigs. In five minipigs, samples of the oral flora were collected with sterile cotton swabs from the buccal gingiva of the lower jaw. Two swabs per animal were collected, followed by bacterial isolation under both aerobe and anaerobe conditions. Microbiological analyses included biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rDNA gene sequence analysis. A total of 61 taxa were detected, 14–21 different bacterial taxa from each minipig. Among the Gram-positive cocci, mainly staphylococcal and streptococcal species were identified. Different Actinomyces species were the most abundant taxa in the group of Gram-positive rods. Among the anaerobic bacteria, the Gram-negative genera Fusobacterium, Bacteroides and Prevotella were the most often observed taxa. This is the first study which begins to describe the normal oral flora in minipigs in cultures to allow for the detection of a broad spectrum. Several bacterial species identified are different from human ones. No specific species for peri-implantitis could be detected in that healthy sample.
Use of Inhaled Epoprostenol in Patients with H1N1 Influenza-Associated Acute Respiratory Distress Syndrome: A Case Series
Authors: McMillen James C , Burke Christopher F , Dhingra Amit , Dudney Tina M , Faircloth Barbara E
Published: May 2011

Objective:

To report a series of patients with confirmed novel influenza A (H1N1) and refractory hypoxemia secondary to acute respiratory distress syndrome (ARDS) treated with inhaled epoprostenol.

Case Summary:

Four patients admitted to our institution with confirmed H1N1 and refractory hypoxemia were treated with inhaled epoprostenol as potential salvage therapy. All patients were treated initially with antimicrobial agents, followed by oral oseltamivir at the time of suspicion or confirmation of H1N1. None of the patients received intravenous peramivir or extracorporeal membrane oxygenation. Clinically significant improvement in oxygenation was seen in only 1 of the patients receiving inhaled epoprostenol. Mortality was significant, with only 1 patient discharged from the hospital.

Discussion:

Use of inhaled epoprostenol for the treatment of hypoxemia secondary to ARDS has been reported, with conflicting results. Deliveries via the inhalational route compared to the intravenous route theoretically preferentially vasodilate well-ventilated areas of the pulmonary vasculature, improving arterial oxygenation and pulmonary gas exchange. Increase in the ratio of arterial oxygen tension to fraction of inhaled oxygen is greatest upon initiation of inhaled epoprostenol, but this benefit has not been conclusively demonstrated to persist throughout therapy. Serious H1N1 presents a unique challenge for clinicians, often requiring the use of salvage therapies to treat critically ill patients.

Conclusions:

Given the variable response to treatment, it remains unclear whether inhaled epoprostenol is beneficial in H1N1-associated ARDS. Identification of patients for whom this therapy is most appropriate remains a clinical challenge.