bluuebunny/crossref_metadata_2025 huggingface dataset:
Population level determinants of acute mountain sickness among young men: a retrospective study
Authors: Li Xiaoxiao , Tao Fasheng , Pei Tao , You Haiyan , Liu Yan , Gao Yuqi
Published: September 2011

Background

Many visitors, including military troops, who enter highland regions from low altitude areas may suffer from acute mountain sickness (AMS), which negatively impacts workable man-hours and increases healthcare costs. The aim of this study was to evaluate the population level risk factors and build a multivariate model, which might be applicable to reduce the effects of AMS on Chinese young men traveling to this region.

Methods

Chinese highland military medical records were used to obtain data of young men (n = 3727) who entered the Tibet plateau between the years of 2006-2009. The relationship between AMS and travel profile, demographic characteristics, and health behaviors were evaluated by logistic regression. Univariate logistic models estimated the crude odds ratio. The variables that showed significance in the univariate model were included in a multivariate model to derive adjusted odds ratios and build the final model. Data corresponding to odd and even years (2 subsets) were analyzed separately and used in a simple cross-validation.

Results

Univariate analysis indicated that travel profile, prophylactic use, ethnicity, and province of birth were all associated with AMS in both subsets. In multivariate analysis, young men who traveled from lower altitude (600-800 m vs. 1300-1500 m, adjusted odds ratio (AOR) = 1.32-1.44) to higher altitudes (4100-4300 m vs. 2900-3100 m, AOR = 3.94-4.12; 3600-3700 m vs. 2900-3100 m, AOR = 2.71-2.74) by air or rapid land transport for emergency mission deployment (emergency land deployment vs. normal land deployment, AOR = 2.08-2.11; normal air deployment vs. normal land deployment, AOR = 2.00-2.20; emergency air deployment vs. normal land deployment, AOR = 2.40-3.34) during the cold season (cold vs. warm, AOR = 1.25-1.28) are at great risk for developing AMS. Non-Tibetan male soldiers (Tibetan vs. Han, AOR = 0.03-0.08), born and raised in lower provinces (eastern vs. northwestern, AOR = 1.32-1.39), and deployed without prophylaxis (prophylactic drug vs. none, AOR = 0.75-0.76), also represented a population at significantly increased risk for AMS. The predicted model was built; the area under receiver operating characteristic curve was 0.703.

Conclusion

Before a group of young men first enter a high altitude area, it is important that a health service plan should be made referring to the group's travel profile and with respect to young men's ethnicity and province of birth. Low-cost Chinese traditional prophylactic drugs might have some effect on decreasing the risk of AMS, although this needs further verification.
Ankles back in randomized controlled trial (ABrCt): braces versus neuromuscular exercises for the secondary prevention of ankle sprains. Design of a randomised controlled trial
Authors: Janssen Kasper W , van Mechelen Willem , Verhagen Evert ALM
Published: September 2011

Background

Ankle sprains are the most common sports and physical activity related injury. There is extensive evidence that there is a twofold increased risk for injury recurrence for at least one year post injury. In up to 50% of all cases recurrences result in disability and lead to chronic pain or instability, requiring prolonged medical care. Therefore ankle sprain recurrence prevention in athletes is essential. This RCT evaluates the effect of the combined use of braces and neuromuscular training (e.g. proprioceptive training/sensorimotor training/balance training) against the individual use of either braces or neuromuscular training alone on ankle sprain recurrences, when applied to individual athletes after usual care.

Methods/Design

This study was designed as three way randomized controlled trial with one year follow-up. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain in the two months prior to inclusion, were eligible for inclusion. After subjects had finished ankle sprain treatment by means of usual care, they were randomised to any of the three study groups. Subjects in group 1 received an eight week neuromuscular training program, subjects in group 2 received a sports brace to be worn during all sports activities for the duration of one year, and group 3 received a combination of the neuromuscular training program and a sports brace to be worn during all sports activities for the duration of eight weeks. Outcomes were assessed at baseline and every month for 12 months therafter. The primary outcome measure was incidence of ankle sprain recurrences. Secondary outcome measures included the direct and indirect costs of recurrent injury, the severity of recurrent injury, and the residual complaints during and after the intervention.

Discussion

The ABrCt is the first randomized controlled trial to directly compare the secondary preventive effect of the combined use of braces and neuromuscular training, against the use of either braces or neuromuscular training as separate secondary preventive measures. This study expects to identify the most effective and cost-efficient secondary preventive measure for ankle sprains. The study results could lead to changes in the clinical guidelines on the prevention of ankle sprains, and they will become available in 2012.

Trial registration

Netherlands Trial Register (NTR): NTR2157
Novel dimeric β-helical model of an ice nucleation protein with bridged active sites
Authors: Garnham Christopher P , Campbell Robert L , Walker Virginia K , Davies Peter L
Published: September 2011

Background

Ice nucleation proteins (INPs) allow water to freeze at high subzero temperatures. Due to their large size (>120 kDa), membrane association, and tendency to aggregate, an experimentally-determined tertiary structure of an INP has yet to be reported. How they function at the molecular level therefore remains unknown.

Results

Here we have predicted a novel β-helical fold for the INP produced by the bacterium Pseudomonas borealis. The protein uses internal serine and glutamine ladders for stabilization and is predicted to dimerize via the burying of a solvent-exposed tyrosine ladder to make an intimate hydrophobic contact along the dimerization interface. The manner in which Pb INP dimerizes also allows for its multimerization, which could explain the aggregation-dependence of INP activity. Both sides of the Pb INP structure have tandem arrays of amino acids that can organize waters into the ice-like clathrate structures seen on antifreeze proteins.

Conclusions

Dimerization dramatically increases the 'ice-active' surface area of the protein by doubling its width, increasing its length, and presenting identical ice-forming surfaces on both sides of the protein. We suggest that this allows sufficient anchored clathrate waters to align on the INP surface to nucleate freezing. As Pb INP is highly similar to all known bacterial INPs, we predict its fold and mechanism of action will apply to these other INPs.
Anti-biofilm activity of an exopolysaccharide from a sponge-associated strain of Bacillus licheniformis
Authors: Sayem SM Abu , Manzo Emiliano , Ciavatta Letizia , Tramice Annabella , Cordone Angela , Zanfardino Anna , De Felice Maurilio , Varcamonti Mario
Published: September 2011

Background

Secondary metabolites ranging from furanone to exo-polysaccharides have been suggested to have anti-biofilm activity in various recent studies. Among these, Escherichia coli group II capsular polysaccharides were shown to inhibit biofilm formation of a wide range of organisms and more recently marine Vibrio sp. were found to secrete complex exopolysaccharides having the potential for broad-spectrum biofilm inhibition and disruption.

Results

In this study we report that a newly identified ca. 1800 kDa polysaccharide having simple monomeric units of α-D-galactopyranosyl-(1→2)-glycerol-phosphate exerts an anti-biofilm activity against a number of both pathogenic and non-pathogenic strains without bactericidal effects. This polysaccharide was extracted from a Bacillus licheniformis strain associated with the marine organism Spongia officinalis. The mechanism of action of this compound is most likely independent from quorum sensing, as its structure is unrelated to any of the so far known quorum sensing molecules. In our experiments we also found that treatment of abiotic surfaces with our polysaccharide reduced the initial adhesion and biofilm development of strains such as Escherichia coli PHL628 and Pseudomonas fluorescens.

Conclusion

The polysaccharide isolated from sponge-associated B. licheniformis has several features that provide a tool for better exploration of novel anti-biofilm compounds. Inhibiting biofilm formation of a wide range of bacteria without affecting their growth appears to represent a special feature of the polysaccharide described in this report. Further research on such surface-active compounds might help developing new classes of anti-biofilm molecules with broad spectrum activity and more in general will allow exploring of new functions for bacterial polysaccharides in the environment.
Antioxidant and inflammatory aspects of lipoprotein-associated phospholipase A2 (Lp-PLA2 ): a review
Authors: Silva Isis T , Mello Ana PQ , Damasceno Nágila RT
Published: September 2011

The association of cardiovascular events with Lp-PLA2has been studied continuously today. The enzyme has been strongly associated with several cardiovascular risk markers and events. Its discovery was directly related to the hydrolysis of the platelet-activating factor and oxidized phospholipids, which are considered protective functions. However, the hydrolysis of bioactive lipids generates lysophospholipids, compounds that have a pro-inflammatory function. Therefore, the evaluation of the distribution of Lp-PLA2in the lipid fractions emphasized the dual role of the enzyme in the inflammatory process, since the HDL-Lp-PLA2enzyme contributes to the reduction of atherosclerosis, while LDL-Lp-PLA2stimulates this process. Recently, it has been verified that diet components and drugs can influence the enzyme activity and concentration. Thus, the effects of these treatments on Lp-PLA2may represent a new kind of prevention of cardiovascular disease. Therefore, the association of the enzyme with the traditional assessment of cardiovascular risk may help to predict more accurately these diseases.
mRNA expression levels and genetic status of genes involved in the EGFR and NF-κB pathways in metastatic non-small-cell lung cancer patients
Authors: Santarpia Mariacarmela , Magri Ignacio , Sanchez-Ronco Maria , Costa Carlota , Molina-Vila Miguel Angel , Gimenez-Capitan Ana , Bertran-Alamillo Jordi , Mayo Clara , Benlloch Susana , Viteri Santiago , Gasco Amaya , Mederos Nuria , Carcereny Enric , Taron Miquel , Rosell Rafael
Published: September 2011

Background

Metastatic non-small-cell lung cancer (NSCLC) has a dismal prognosis. EGFR is overexpressed or mutated in a large proportion of cases. Downstream components of the EGFR pathway and crosstalk with the NF-κB pathway have not been examined at the clinical level. We explored the prognostic significance of the mRNA expression of nine genes in the EGFR and NF-κB pathways and of BRCA1 and RAP80 in patients in whom EGFR and K-ras gene status had previously been determined. In addition, NFKBIA and DUSP22 gene status was also determined.

Methods

mRNA expression of the eleven genes was determined by QPCR in 60 metastatic NSCLC patients and in nine lung cancer cell lines. Exon 3 of NFKBIA and exon 6 of DUSP22 were analyzed by direct sequencing. Results were correlated with outcome to platinum-based chemotherapy in patients with wild-type EGFR and to erlotinib in those with EGFR mutations.

Results

BRCA1 mRNA expression was correlated with EZH2, AEG-1, Musashi-2, CYLD and TRAF6 expression. In patients with low levels of both BRCA1 and AEG-1, PFS was 13.02 months, compared to 5.4 months in those with high levels of both genes and 7.7 months for those with other combinations (P = 0.025). The multivariate analysis for PFS confirmed the prognostic role of high BRCA1/AEG-1 expression (HR, 3.1; P = 0.01). Neither NFKBIA nor DUSP22 mutations were found in any of the tumour samples or cell lines.

Conclusions

The present study provides a better understanding of the behaviour of metastatic NSCLC and identifies the combination of BRCA1 and AEG-1 expression as a potential prognostic model.
Replication efficiency of oncolytic vaccinia virus in cell cultures prognosticates the virulence and antitumor efficacy in mice
Authors: Chen Nanhai G , Yu Yong A , Zhang Qian , Szalay Aladar A
Published: September 2011

Background

We have shown that insertion of the three vaccinia virus (VACV) promoter-driven foreign gene expression cassettes encoding Renilla luciferase-Aequorea GFP fusion protein, β-galactosidase, and β-glucuronidase into the F14.5L, J2R, and A56R loci of the VACV LIVP genome, respectively, results in a highly attenuated mutant strain GLV-1h68. This strain shows tumor-specific replication and is capable of eradicating tumors with little or no virulence in mice. This study aimed to distinguish the contribution of added VACV promoter-driven transcriptional units as inserts from the effects of insertional inactivation of three viral genes, and to determine the correlation between replication efficiency of oncolytic vaccinia virus in cell cultures and the virulence and antitumor efficacy in mice

Methods

A series of recombinant VACV strains was generated by replacing one, two, or all three of the expression cassettes in GLV-1h68 with short non-coding DNA sequences. The replication efficiency and tumor cell killing capacity of these newly generated VACV strains were compared with those of the parent virus GLV-1h68 in cell cultures. The virus replication efficiency in tumors and antitumor efficacy as well as the virulence were evaluated in nu/nu (nude) mice bearing human breast tumor xenografts.

Results

we found that virus replication efficiency increased with removal of each of the expression cassettes. The increase in virus replication efficiency was proportionate to the strength of removed VACV promoters linked to foreign genes. The replication efficiency of the new VACV strains paralleled their cytotoxicity in cell cultures. The increased replication efficiency in tumor xenografts resulted in enhanced antitumor efficacy in nude mice. Similarly, the enhanced virus replication efficiency was indicative of increased virulence in nude mice.

Conclusions

These data demonstrated that insertion of VACV promoter-driven transcriptional units into the viral genome for the purpose of insertional mutagenesis did modulate the efficiency of virus replication together with antitumor efficacy as well as virulence. Replication efficiency of oncolytic VACV in cell cultures can predict the virulence and therapeutic efficacy in nude mice. These findings may be essential for rational design of safe and potent VACV strains for vaccination and virotherapy of cancer in humans and animals.
The role of amputation as an outcome measure in cellular therapy for critical limb ischemia: implications for clinical trial design
Authors: Benoit Eric , O'Donnell Thomas F , Iafrati Mark D , Asher Enrico , Bandyk Dennis F , Hallett John W , Lumsden Alan B , Pearl Gregory J , Roddy Sean P , Vijayaraghavan Krishnaswami , Patel Amit N
Published: September 2011

Background

Autologous bone marrow-derived stem cells have been ascribed an important therapeutic role in No-Option Critical limb Ischemia (NO-CLI). One primary endpoint for evaluating NO-CLI therapy is major amputation (AMP), which is usually combined with mortality for AMP-free survival (AFS). Only a trial which is double blinded can eliminate physician and patient bias as to the timing and reason for AMP. We examined factors influencing AMP in a prospective double-blinded pilot RCT (2:1 therapy to control) of 48 patients treated with site of service obtained bone marrow cells (BMAC) as well as a systematic review of the literature.

Methods

Cells were injected intramuscularly in the CLI limbs as either BMAC or placebo (peripheral blood). Six month AMP rates were compared between the two arms. Both patient and treating team were blinded of the assignment in follow-up examinations. A search of the literature identified 9 NO-CLI trials, the control arms of which were used to determine 6 month AMP rates and the influence of tissue loss.

Results

Fifteen amputations occurred during the 6 month period, 86.7% of these during the first 4 months. One amputation occurred in a Rutherford 4 patient. The difference in amputation rate between patients with rest pain (5.6%) and those with tissue loss (46.7%), irrespective of treatment group, was significant (p = 0.0029). In patients with tissue loss, treatment with BMAC demonstrated a lower amputation rate than placebo (39.1% vs. 71.4%, p = 0.1337). The Kaplan-Meier time to amputation was longer in the BMAC group than in the placebo group (p = 0.067). Projecting these results to a pivotal trial, a bootstrap simulation model showed significant difference in AFS between BMAC and placebo with a power of 95% for a sample size of 210 patients. Meta-analysis of the literature confirmed a difference in amputation rate between patients with tissue loss and rest pain.

Conclusions

BMAC shows promise in improving AMP-free survival if the trends in this pilot study are validated in a larger pivotal trial. The difference in amp rate between Rutherford 4 & 5 patients suggests that these patients should be stratified in future RCTs.
Surgical treatment of giant plexiform neurofibroma associated with pectus excavatum
Authors: Ji Yi , Xu Bing , Wang Xuejun , Liu Wenying , Chen Siyuan
Published: September 2011

Plexiform neurofibromas are benign tumors originating from subcutaneous or visceral peripheral nerves, which are usually associated with neurofibromatosis type 1. They are almost always congenital lesions and often cause the surrounding soft tissue and bone to grow aberrantly. We treated a 12-year-old boy who presented with asymmetric pectus excavaum and an anterior chest wall plexiform neurofibroma. The pectus excavaum was corrected by modified Nuss procedure, followed by simultaneous resection of the giant mass. The patient is doing well at the 4 years follow-up visit.
Bilobular calcifying fibrous pseudotumor in soleus muscle: a case report
Authors: Shinohara Naohiro , Nagano Satoshi , Yokouchi Masahiro , Arishima Yoshiya , Tabata Kazuhiro , Higashi Michiyo , Kitajima Shinichi , Yonezawa Suguru , Komiya Setsuro
Published: September 2011

Introduction

Calcifying fibrous pseudotumor is a rare benign soft-tissue lesion composed of fibrous tissue with abundant hyalinized collagen and dystrophic and often psammomatous calcifications. The cause of the disease is unclear but, usually, complete resection of the well-circumscribed tumor is sufficient to avoid recurrence of the disease. Here, we report an unusual case of this rare tumor that presented as two lobulated lesions in the calf muscle.

Case presentation

The patient was a 17-year-old Japanese girl who noted a hard mass in her left calf. Magnetic resonance imaging revealed two well-demarcated lobular masses in the soleus muscle, and the tumor was significantly enhanced by contrast medium. Preoperative differential diagnoses included soft-part tumors composed of fibrous tissue. However, making a definite diagnosis was impossible because a lobulated shape is rare for fibrous tumors. Biopsy demonstrated that the mass was a benign tumor composed of collagen-rich, hyalinized fibrosclerotic tissue. We performed marginal resection of the two nodules, including the fibrous tissue that connected them. Immunohistochemistry was positive for factor XIIIa and negative for anaplastic lymphoma kinase-1. These findings were helpful to distinguish calcifying fibrous pseudotumor from inflammatory myofibroblastic tumor. There was no sign of recurrence at 30 months after surgery.

Conclusion

To the best of our knowledge, this is the first case of bilobular calcifying fibrous pseudotumor that developed in an extremity. As described in the previous literature, simple excision was sufficient for the treatment of calcifying fibrous pseudotumor with two lobules.
Trends in the clinical characteristics of HIV‐infected patients initiating antiretroviral therapy in Kenya, Uganda and Tanzania between 2002 and 2009
Authors: Geng Elvin H , Hunt Peter W , Diero Lameck O , Kimaiyo Sylvester , Somi Geofrey R , Okong Pius , Bangsberg David R , Bwana Mwebesa B , Cohen Craig R , Otieno Juliana A , Wabwire Deo , Elul Batya , Nash Denis , Easterbrook Philippa J , Braitstein Paula , Musick Beverly S , Martin Jeffrey N , Yiannoutsos Constantin T , Wools‐Kaloustian Kara
Published: September 2011

Background

East Africa has experienced a rapid expansion in access to antiretroviral therapy (ART) for HIV‐infected patients. Regionally representative socio‐demographic, laboratory and clinical characteristics of patients accessing ART over time and across sites have not been well described.

Methods

We conducted a cross‐sectional analysis of characteristics of HIV‐infected adults initiating ART between 2002 and 2009 in Kenya, Uganda and Tanzania and in the International Epidemiologic Databases to Evaluate AIDS Consortium. Characteristics associated with advanced disease (defined as either a CD4 cell count level of less than 50 cells/mm3 or a WHO Stage 4 condition) at the time of ART initiation and use of stavudine (D4T) or nevirapine (NVP) were identified using a log‐link Poisson model with robust standard errors.

Results

Among 48, 658 patients (69% from Kenya, 22% from Uganda and 9% from Tanzania) accessing ART at 30 clinic sites, the median age at the time of ART initiation was 37 years (IQR: 31‐43) and 65% were women. Pre‐therapy CD4 counts rose from 87 cells/mm3 (IQR: 26‐161) in 2002‐03 to 154 cells/mm3 (IQR: 71‐233) in 2008‐09 (p < 0.001). Accessing ART at advanced disease peaked at 35% in 2005‐06 and fell to 27% in 2008‐09. D4T use in the initial regimen fell from a peak of 88% in 2004‐05 to 59% in 2008‐09, and a greater extent of decline was observed in Uganda than in Kenya and Tanzania. Self‐pay for ART peaked at 18% in 2003, but fell to less than 1% by 2005. In multivariable analyses, accessing ART at advanced immunosuppression was associated with male sex, women without a history of treatment for prevention of mother to child transmission (both as compared with women with such a history) and younger age after adjusting for year of ART initiation and country of residence. Receipt of D4T in the initial regimen was associated with female sex, earlier year of ART initiation, higher WHO stage, and lower CD4 levels at ART initiation and the absence of co‐prevalent tuberculosis.

Conclusions

Public health ART services in east Africa have improved over time, but the fraction of patients accessing ART with advanced immunosuppression is still high, men consistently access ART with more advanced disease, and D4T continues to be common in most settings. Strategies to facilitate access to ART, overcome barriers among men and reduce D4T use are needed.
From population to HIV: the organizational and structural determinants of HIV outcomes in sub‐Saharan Africa
Authors: Robinson Rachel Sullivan
Published: September 2011

Background

There exists no consistent explanation for why some countries are successful in combating HIV/AIDS and others are not, and we need such an explanation in order to design effective policies and programmes. Research evaluating HIV interventions from a biomedical or public health perspective does not always take full account of the historical and organizational characteristics of countries likely to influence HIV outcomes. The analysis in this paper addresses this shortcoming by testing the impact of organizational and structural factors, particularly those resulting from population interventions, on HIV outcomes at the country level in sub‐Saharan Africa.

Methods

The primary independent variables are factors that originated from efforts to slow population growth: whether a country has a long‐time affiliate of the International Planned Parenthood Federation and whether a country has a population policy. Additional structural factors likely to impact HIV outcomes include the level of wealth, the level of cultural fractionalization, and the former colonial power. The present study uses multivariate regression techniques with countries in sub‐Saharan Africa as the unit of analysis, and four measures of success in addressing HIV: the change in prevalence between 2001 and 2009; the change in incidence between 2001 and 2009; the level of overall antiretroviral coverage in 2009; and the level of antiretroviral coverage for prevention of vertical transmission in 2009.

Results

Countries with the greatest declines in HIV prevalence and incidence had older International Planned Parenthood Federation affiliates and had adopted population policies, even after controlling for age of epidemic, level of antiretroviral coverage, and funding for HIV. Population policies are also important predictors of levels of overall antiretroviral coverage and of coverage of HIV‐positive pregnant women to prevent vertical transmission. Structural factors with significant impacts include wealth, cultural fractionalization and former colonial power.

Conclusions

The organizational and structural context of African countries is strongly predictive of HIV outcomes. This finding implies that policy and programmatic efforts should be put towards strengthening existing organizations and perhaps even creating new ones. The fact that cultural fractionalization also influences HIV outcomes suggests that efforts must be put towards identifying ways to reach political consensus in diverse societies.
Comparison of solution-based exome capture methods for next generation sequencing
Authors: Sulonen Anna-Maija , Ellonen Pekka , Almusa Henrikki , Lepistö Maija , Eldfors Samuli , Hannula Sari , Miettinen Timo , Tyynismaa Henna , Salo Perttu , Heckman Caroline , Joensuu Heikki , Raivio Taneli , Suomalainen Anu , Saarela Janna
Published: September 2011

Background

Techniques enabling targeted re-sequencing of the protein coding sequences of the human genome on next generation sequencing instruments are of great interest. We conducted a systematic comparison of the solution-based exome capture kits provided by Agilent and Roche NimbleGen. A control DNA sample was captured with all four capture methods and prepared for Illumina GAII sequencing. Sequence data from additional samples prepared with the same protocols were also used in the comparison.

Results

We developed a bioinformatics pipeline for quality control, short read alignment, variant identification and annotation of the sequence data. In our analysis, a larger percentage of the high quality reads from the NimbleGen captures than from the Agilent captures aligned to the capture target regions. High GC content of the target sequence was associated with poor capture success in all exome enrichment methods. Comparison of mean allele balances for heterozygous variants indicated a tendency to have more reference bases than variant bases in the heterozygous variant positions within the target regions in all methods. There was virtually no difference in the genotype concordance compared to genotypes derived from SNP arrays. A minimum of 11× coverage was required to make a heterozygote genotype call with 99% accuracy when compared to common SNPs on genome-wide association arrays.

Conclusions

Libraries captured with NimbleGen kits aligned more accurately to the target regions. The updated NimbleGen kit most efficiently covered the exome with a minimum coverage of 20×, yet none of the kits captured all the Consensus Coding Sequence annotated exons.
Calcium Insufficiency Accelerates Type 1 Diabetes in Vitamin D Receptor-Deficient Nonobese Diabetic (NOD) Mice
Authors: Driver John P. , Lamont Deanna J. , Gysemans Conny , Mathieu Chantal , Serreze David V.
Published: September 2011

Vitamin D exerts important regulatory effects on the endocrine and immune systems. Autoimmune type 1 diabetes (T1D) development in the inbred NOD mouse strain can be accelerated by vitamin D insufficiency or suppressed by chronic treatment with high levels of 1α,25-dihydroxyvitamin D3. Consequently, a report that T1D development was unaffected in NOD mice genetically lacking the vitamin D receptor (VDR) was unexpected. To further assess this result, the mutant stock was imported to The Jackson Laboratory, backcrossed once to NOD/ShiLtJ, and progeny rederived through embryo transfer. VDR-deficient NOD mice of both sexes showed significant acceleration of T1D. This acceleration was not associated with alterations in immune cells targeting pancreatic β-cells. Rather, the capacity of β-cells to produce and/or secrete insulin was severely impaired by the hypocalcaemia developing in VDR-deficient NOD mice fed a standard rodent chow diet. Feeding a high-lactose calcium rescue diet that circumvents a VDR requirement for calcium absorption from the intestine normalized serum calcium levels, restored β-cell insulin secretion, corrected glucose intolerance, and eliminated accelerated T1D in VDR-deficient NOD mice. These findings suggest that calcium and/or vitamin D supplementation may improve disease outcomes in some T1D-prone individuals that are calcium deficient.
Sirt1 Is a Regulator of Bone Mass and a Repressor of Sost Encoding for Sclerostin, a Bone Formation Inhibitor
Authors: Cohen-Kfir Einav , Artsi Hanna , Levin Avi , Abramowitz Eva , Bajayo Alon , Gurt Irina , Zhong Lei , D'Urso Agustina , Toiber Debra , Mostoslavsky Raul , Dresner-Pollak Rivka
Published: September 2011

Sirt1, the mammalian ortholog of the yeast Sir2 (silent information regulator 2), was shown to play an important role in metabolism and in age-associated diseases, but its role in skeletal homeostasis and osteoporosis has yet not been studied. Using 129/Sv mice with a germline mutation in the Sirt1 gene, we demonstrate that Sirt1 haplo-insufficient (Sirt1+/−) female mice exhibit a significant reduction in bone mass characterized by decreased bone formation and increased marrow adipogenesis. Importantly, we identify Sost, encoding for sclerostin, a critical inhibitor of bone formation, as a novel target of Sirt1. Using chromatin immunoprecipitation analysis, we reveal that Sirt1 directly and negatively regulates Sost gene expression by deacetylating histone 3 at lysine 9 at the Sost promoter. Sost down-regulation by small interfering RNA and the administration of a sclerostin-neutralizing antibody restore gene expression of osteocalcin and bone sialoprotein as well as mineralized nodule formation in Sirt1+/− marrow-derived mesenchymal stem cells induced to osteogenesis. These findings reveal a novel role for Sirt1 in bone as a regulator of bone mass and a repressor of sclerostin, and have potential implications suggesting that Sirt1 is a target for promoting bone formation as an anabolic approach for treatment of osteoporosis.
A Role for Metalloendopeptidases in the Breakdown of the Gut Hormone, PYY3–36
Authors: Addison Melisande L. , Minnion James S. , Shillito Joy C. , Suzuki Keisuke , Tan Tricia M. , Field Benjamin C. T. , Germain-Zito Natacha , Becker-Pauly Christoph , Ghatei Mohammad A. , Bloom Stephen R. , Murphy Kevin G.
Published: September 2011

Peptide YY3–36 (PYY3–36) is a gut hormone that acts on Y2 receptors to reduce appetite. Obese humans are sensitive to the anorectic effects of PYY3–36 and display a blunted postprandial rise in PYY3–36. Bariatric surgery results in increased circulating PYY-immunoreactivity, which appears to play a role in postoperative weight loss. The utility of PYY3–36 as an antiobesity treatment is limited by its short circulating half-life. Insight into the mechanisms by which PYY3–36 is degraded may aid design of long-acting PYY3–36 analogues or enzyme inhibitor therapies. We aimed to investigate the role of metalloendopeptidases in PYY3–36 degradation and determine whether modulation of these enzymes enhanced PYY3–36 plasma levels and bioactivity in vivo. Degradation and resultant cleavage products of PYY3–36 were characterized after incubation with neprilysin and meprin β and with a kidney brush border preparation in vitro. Specific metalloendopeptidase inhibitors were coadministered with PYY3–36 to mice and subsequent PYY3–36 plasma levels and bioactivity determined. Meprin β cleaves PYY3–36 at multiple conserved acidic sites. Blocking the actions of meprin β prevents the degradative effect of kidney brush borders on PYY3–36. In mice, pretreatment with actinonin significantly prolonged the anorectic effect of PYY3–36 and maintained higher PYY3–36 plasma levels than treatment with PYY3–36 alone. These studies suggest that inhibiting the degradation of PYY3–36 using specific inhibitor therapies and/or the design of analogues resistant to cleavage by meprins may be useful to antiobesity therapeutics.
Intrinsic Sexually Dimorphic Expression of the Principal Human CYP3A4 Correlated with Suboptimal Activation of GH/Glucocorticoid-Dependent Transcriptional Pathways in Men
Authors: Thangavel Chellappagounder , Boopathi Ettickan , Shapiro Bernard H.
Published: September 2011

Cytochrome P450 (CYP)3A4 is the principal and most abundant human isoform of CYP responsible for the metabolism of more than 50% of all consumed drugs and innumerable endogenous compounds. Expression of CYP3A4 is sexually dimorphic and regulated by the combined actions of GH and glucocorticoids. In the case of the rat, nearly all of the CYPs are “intrinsically” or “inherently” sexually dimorphic, meaning that the expressed sex differences are permanent and irreversible. Using primary hepatocyte cultures derived from men and women exposed to physiologic-like levels of continuous GH (the feminine circulating profile) alone, dexamethasone alone, and the combined regimen, we observed a dramatic inherent CYP3A4 sexual dimorphism (women more than men) with all treatments. The molecular basis for this intrinsic sexually dimorphic expression of CYP3A4 appears to be due, at least in part, to a greater level of hormone-dependent activation and nuclear translocation of both hepatocyte nuclear factor-4α (HNF-4α) and pregnane X receptor in female hepatocytes. Furthermore, these transcription factors exhibited significantly higher DNA binding levels to their specific motifs on the CYP3A4 promoter in female hepatocytes, inferring a possible explanation for the elevated expression of CYP3A4 in women. Accordingly, experiments using HepG2 cells treated with small inhibitory RNA-induced knockdown of HNF-4α and/or transfected with luciferase reporter constructs containing a CYP3A4 promoter lacking HNF-4α-binding motifs demonstrated that GH, to a greater extent dexamethasone, and to the greatest extent the combine hormone regimen, stimulated HNF-4α and pregnane X receptor promoter transactivation, signifying enhanced transcription of CYP3A4 and, thus, identifying a molecular mechanism contributing to the intrinsic sexual dimorphic expression of human CYP3A4.
Depletion of Bhmt Elevates sonic hedgehog Transcript Level and Increases β-Cell Number in Zebrafish
Authors: Yang Shu-Lan , Aw Sharon Siqi , Chang Changqing , Korzh Svetlana , Korzh Vladimir , Peng Jinrong
Published: September 2011

Betaine homocysteine S-methyltransferase (BHMT, EC 2.1.1.5) is a key enzyme in the methionine cycle and is highly expressed in the liver. Despite its important biochemical function, it is not known whether BHMT plays a role during organ development. In this report, we showed that early in development of zebrafish before endoderm organogenesis, bhmt is first expressed in the yolk syncytial layer and then after liver formation becomes a liver-enriched gene. By using the anti-bhmt morpholinos that deplete the Bhmt, we found that in morphant embryos, several endoderm-derived organs, including liver, exocrine pancreas, and intestine are hypoplastic. Strikingly, the number of β-cells in the pancreatic islet was increased rather than reduced in the morphant. Additional studies showed that Bhmt depletion elevates the sonic hedgehog (shh) transcript level in the morphant, whereas Bhmt-depletion in the Shh-deficient mutant syu failed to rescue the isletless phenotype. These molecular and genetic data strongly suggest that Shh functions downstream of Bhmt to promote β-cell development. Therefore, although there are still many intriguing questions to be answered, our finding may identify a novel function for Bhmt involving modulation of Shh signaling to control β-cell development.
Influence of Estrogens on GH-Cell Network Dynamics in Females: A Live in Situ Imaging Approach
Authors: Schaeffer Marie , Hodson David J. , Meunier Anne-Cécile , Lafont Chrystel , Birkenstock Jérôme , Carmignac Danielle , Murray Joanne F. , Gavois Elodie , Robinson Iain C. , Le Tissier Paul , Mollard Patrice
Published: September 2011

The secretion of endocrine hormones from pituitary cells finely regulates a multitude of homeostatic processes. To dynamically adapt to changing physiological status and environmental stimuli, the pituitary gland must undergo marked structural and functional plasticity. Endocrine cell plasticity is thought to primarily rely on variations in cell proliferation and size. However, cell motility, a process commonly observed in a variety of tissues during development, may represent an additional mechanism to promote plasticity within the adult pituitary gland. To investigate this, we used multiphoton time-lapse imaging methods, GH-enhanced green fluorescent protein transgenic mice and sexual dimorphism of the GH axis as a model of divergent tissue demand. Using these methods to acutely (12 h) track cell dynamics, we report that ovariectomy induces a dramatic and dynamic increase in cell motility, which is associated with gross GH-cell network remodeling. These changes can be prevented by estradiol supplementation and are associated with enhanced network connectivity as evidenced by increased coordinated GH-cell activity during multicellular calcium recordings. Furthermore, cell motility appears to be sex-specific, because reciprocal alterations are not detected in males after castration. Therefore, GH-cell motility appears to play an important role in the structural and functional pituitary plasticity, which is evoked in response to changing estradiol concentrations in the female.
Animal models for Gaucher disease research
Authors: Farfel-Becker Tamar , Vitner Einat B. , Futerman Anthony H.
Published: September 2011

Gaucher disease (GD), the most common lysosomal storage disorder (LSD), is caused by the defective activity of the lysosomal hydrolase glucocerebrosidase, which is encoded by the GBA gene. Generation of animal models that faithfully recapitulate the three clinical subtypes of GD has proved to be more of a challenge than first anticipated. The first mouse to be produced died within hours after birth owing to skin permeability problems, and mice with point mutations in Gba did not display symptoms correlating with human disease and also died soon after birth. Recently, conditional knockout mice that mimic some features of the human disease have become available. Here, we review the contribution of all currently available animal models to examining pathological pathways underlying GD and to testing the efficacy of new treatment modalities, and propose a number of criteria for the generation of more appropriate animal models of GD.
Moment-to-moment flight manoeuvres of the female yellow fever mosquito (Aedes aegyptiL.) in response to plumes of carbon dioxide and human skin odour
Authors: Dekker Teun , Cardé Ring T.
Published: September 2011

Odours are crucial cues enabling female mosquitoes to orient to prospective hosts. However, their in-flight manoeuvres to host odours are virtually unknown. Here we analyzed in 3-D the video records of female Aedes aegypti mosquitoes flying in a wind tunnel in response to host odour plumes that differed in spatial structure and composition. Following a brief (∼0.03 s) encounter with CO2, mosquitoes surged upwind and, in the absence of further encounters, counterturned without displacing upwind. These patterns resemble moth responses to encounter and loss of a filament of pheromone. Moreover, CO2 encounters induced a highly regular pattern of counterturning across the windline in the horizontal (crosswind) and vertical planes, causing the mosquito to transect repeatedly the area where CO2 was previously detected. However, despite the rapid changes across all three axes following an encounter with CO2, the angular velocities remained remarkably constant. This suggests that during these CO2-induced surges mosquitoes stabilize flight through sensors, such as the halteres and Johnston organs, sensitive to Coriolis forces. In contrast to the instantaneous responses of the mosquito CO2, a brief encounter with a filament of human skin odour did not induce a consistent change in mosquito flight. These differential responses were reflected in further experiments with broad plumes. A broad homogeneous plume of skin odour induced rapid upwind flight and source finding, whereas a broad filamentous plume of skin odour lowered activation rates, kinetic responses and source finding compared with homogeneous plumes. Apparently, yellow fever mosquitoes need longer continuous exposure to complex skin-odour blends to induce activation and source finding.
Femoral loading mechanics in the Virginia opossum,Didelphis virginiana: torsion and mediolateral bending in mammalian locomotion
Authors: Gosnell W. Casey , Butcher Michael T. , Maie Takashi , Blob Richard W.
Published: September 2011

Studies of limb bone loading in terrestrial mammals have typically found anteroposterior bending to be the primary loading regime, with torsion contributing minimally. However, previous studies have focused on large, cursorial eutherian species in which the limbs are held essentially upright. Recent in vivo strain data from the Virginia opossum (Didelphis virginiana), a marsupial that uses a crouched rather than an upright limb posture, have indicated that its femur experiences appreciable torsion during locomotion as well as strong mediolateral bending. The elevated femoral torsion and strong mediolateral bending observed in D. virginiana might result from external forces such as a medial inclination of the ground reaction force (GRF), internal forces deriving from a crouched limb posture, or a combination of these factors. To evaluate the mechanism underlying the loading regime of opossum femora, we filmed D. virginiana running over a force platform, allowing us to measure the magnitude of the GRF and its three-dimensional orientation relative to the limb, facilitating estimates of limb bone stresses. This three-dimensional analysis also allows evaluations of muscular forces, particularly those of hip adductor muscles, in the appropriate anatomical plane to a greater degree than previous two-dimensional analyses. At peak GRF and stress magnitudes, the GRF is oriented nearly vertically, inducing a strong abductor moment at the hip that is countered by adductor muscles on the medial aspect of the femur that place this surface in compression and induce mediolateral bending, corroborating and explaining loading patterns that were identified in strain analyses. The crouched orientation of the femur during stance in opossums also contributes to levels of femoral torsion as high as those seen in many reptilian taxa. Femoral safety factors were as high as those of non-avian reptiles and greater than those of upright, cursorial mammals, primarily because the load magnitudes experienced by opossums are lower than those of most mammals. Thus, the evolutionary transition from crouched to upright posture in mammalian ancestors may have been accompanied by an increase in limb bone load magnitudes.
Electrochemical Control of Threshold Value of Molecular Valve Consisting of Poly(acrylic acid) Gel
Authors: Takada Kazutake , Ohara Tetsuya , Takeue Kouki , Ishikura Natsumi , Kato Chie , Yuchi Akio
Published: September 2011

A molecular valve, consisting of a poly(acrylic acid) gel-coated Au mesh and a Au mesh working electrode, allowed electrochemically control of a concentration where the valve opens. At open circuit and when +0.9 V vs. Ag/AgCl was applied to the Au mesh electrode, the valve opened at concentration higher than 3–4 × 10−4 M. At −0.7 V it increased to 9 × 10−4 M. On the other hand, it remained virtually constant for Ca2+ at those potentials.
Tuning the Nitrogen Content and Porosity of Nanostructured Carbon Nitride Using Aminoclay as a Reactive Template
Authors: Kumar B V V S Pavan , Datta K K R , Eswaramoorthy Muthusamy
Published: September 2011

The use of two-dimensional templates like clay, in the synthesis of graphitic carbon nitrides, make it feasible to form exfoliated layer like structures by polymerization of the precursors in the clay galleries. We have used clay linked with aminopropyl groups, aminoclay, to template the carbon nitride into mesolamellar structures. By virtue of its aminopropyl groups, aminoclay is further capable of reacting along with the intercalated precursors to enrich the carbon content of the resulting carbon nitrides.
Gas-phase Infrared Spectroscopy of Monopeptides from 10 to 3 µm
Authors: Miyazaki Mitsuhiko , Makara Koji , Ishiuchi Shun-ichi , Fujii Masaaki
Published: September 2011

Infrared spectra of protected amino acids, N-benzoxycarbonyl-l-proline and N-benzoxycarbonyl-l-isoleucine were measured in the gas phase from 10 to 3 µm. 4 and 3 conformers were found, respectively. The spectra in the 3 µm region reveal the carboxylic OH and amide NH bonds do not participate in hydrogen bonding with neighboring amide groups despite the highest acidity in the molecule. The spectra in the 10–5 µm region imply the main chain structure is the same among the conformers.
A Highly Selective Fluorescence Turn-on Probe for Zn2+ Based on New Diaryloxadiazole Chelate
Authors: Mashraqui Sabir H , Chandiramani Mukesh A , Ghorpade Sushil S , Estarellas Carolina , Frontera Antonio
Published: September 2011

A new chelating diaryloxadiazole probe, oxazid displayed emission red shift and 16-fold emission enhancement upon binding with Zn2+ in buffered condition, while competing Cd2+, Ca2+, Mg2+, and several potentially quenching metal ions posed no significant optical interferences. Experimental evidences indicated 1:1 complexation, and the computational work revealed formation of a stable octahedral geometry.
Synthesis and Skeletal Transformation of Cyanamido(2–)- and Cyanamido(1–)-Bridged Ruthenium Complexes with Hexamethylbenzene Ligands
Authors: Nogami Tadahiko , Imaji Makoto , Uemura Kaoru , Tanabe Yoshiaki , Mutoh Yuichiro , Ishii Youichi
Published: September 2011

A series of cyanamido-bridged di- and tetraruthenium complexes with η6-C6Me6 ligands have been synthesized, and their interconversion reactions have been investigated. Facile interconversion between the μ2-κN,κN and μ2-κN,κN′ coordination modes of NCNH ligands at a dimetallic core has been observed for the first time.
Highly Dichroic Bisazomethine Dye Films on Friction-transferred Poly(tetrafluoroethylene) Layers
Authors: Tanaka Toshihiko , Satoh Miei , Ishitobi Masamitsu , Aoyama Tetsuya , Matsumoto Shinya
Published: September 2011

Highly anisotropic thin molecular films have been successfully prepared by depositing a bisazomethine dye under vacuum through evaporation on friction-transferred (FT) poly(tetrafluoroethylene) (PTFE) layers. The layers induce the high orientational degrees showing high dichroic ratios over 20 in their polarized UV–visible absorption spectra. Moreover, by modifying FT layers with the further PTFE evaporated and rubbing, the ratios are improved to remarkable values up to 44.