Escherichia coli Shiga toxins induce apoptosis in epithelial cells that is regulated by the Bcl-2 family

Human intestinal cells lack globotriaosylceramide (Gb(3)), the receptor for Shiga toxin-1 (Stx1) and Shiga toxin-2 (Stx2). Therefore, the role of these toxins in mediating intestinal disease during infection with Shiga toxin-producing Escherichia coli is unclear. The aims of this study were to determine whether Stx1 and Stx2 induce apoptosis in epithelial cells expressing (HEp-2, Caco-2) or lacking (T84) Gb(3) and to characterize the role of the Bcl-2 family. Stx1 (12.5 ng/ml) induced apoptosis in both HEp-2 (21.9 +/- 7.9% vs. 0.8 +/- 0.3%, P = 0.01) and Caco-2 (10.1 +/- 1.2% vs. 3.1 +/- 0.4%, P = 0.006) cells but not in Gb(3)-deficient T84 cells. Toxin-mediated apoptosis of HEp-2 cells was associated with enhanced expression of the proapoptotic protein Bax. Inhibition of caspase activation prevented toxin-stimulated apoptosis. In addition, overexpression of Bcl-2 by transient transfection blocked Stx1-stimulated cell death. These findings indicate that Shiga toxins produced by E. coli signal Gb(3)-expressing epithelial cells to undergo apoptosis in association with enhanced Bax expression, thereby resulting in activation of the caspase cascade.     

Coronary and cardiovascular risk estimation for primary prevention: validation of a new Sheffield table in the 1995 Scottish health survey population

ObjectiveTo examine the accuracy of a new version of the Sheffield table designed to aid decisions on lipids screening and detect thresholds for risk of coronary heart disease needed to implement current guidelines for primary prevention of cardiovascular disease.DesignComparison of decisions made on the basis of the table with absolute risk of coronary heart disease or cardiovascular disease calculated by the Framingham risk function. The decisions related to statin treatment when coronary risk is ⩾30% over 10 years; aspirin treatment when the risk is ⩾15% over 10 years; and the treatment of mild hypertension when the cardiovascular risk is ⩾20% over 10 years.SettingThe table is designed for use in general practice.SubjectsRandom sample of 1000 people aged 35-64 years from the 1995 Scottish health survey.Results13% of people had a coronary risk of ⩾15%, and 2.2% a risk of ⩾30%, over 10 years. 22% had mild hypertension (systolic blood pressure 140-159 mm Hg). The table indicated lipids screening for everyone with a coronary risk of ⩾15% over 10 years, for 95% of people with a ratio of total cholesterol to high density lipoprotein cholesterol of ⩾8.0, but for <50% with a coronary risk of <5% over 10 years. Sensitivity and specificity were 97% and 95% respectively for a coronary risk of ⩾15% over 10 years; 82% and 99% for a coronary risk of ⩾30% over 10 years; and 88% and 90% for a cardiovascular risk of ⩾20% over 10 years in mild hypertension.ConclusionThe table identifies all high risk people for lipids screening, reduces screening of low risk people by more than half, and ensures that treatments are prescribed appropriately to those at high risk, while avoiding inappropriate treatment of people at low risk.     

Molecular analysis of 16 Turkish families with DHPR deficiency using denaturing gradient gel electrophoresis (DGGE)

Dihydropteridine reductase (DHPR) catalyses the conversion of quinonoid dihydrobiopterin (qBH2) to tetrahydrobiopterin (BH4), which serves as the obligatory cofactor for the aromatic amino acid hydroxylases. DHPR deficiency, caused by mutations in the QDPR gene, results in hyperphenylalaninemia and deficiency of various neurotransmitters in the central nervous system, with severe neurological symptoms as a consequence. We have studied, at the clinical and molecular levels, 17 patients belonging to 16 Turkish families with DHPR deficiency. The patients were detected at neonatal screening for hyperphenylalaninemia or upon the development of neurological symptoms. To identify the disease causing molecular defects, we developed a sensitive screening method that rapidly scans the entire open reading frame and all splice sites of the QDPR gene. This method combines PCR amplification and "GC-clamping" of each of the seven exonic regions of QDPR, resolution of mutations by denaturing gradient gel electrophoresis (DGGE), and identification of mutations by direct sequence analysis. A total of ten different mutations were identified, of which three are known (G23D, Y150C, R221X) and the remaining are novel (G17R, G18D, W35fs, Q66R, W90X, S97fs and G149R). Six of these mutations are missense variants, two are nonsense mutations, and two are frameshift mutations. All patients had homoallelic genotypes, which allowed the establishment of genotype-phenotype associations. Our findings suggest that DGGE is a fast and efficient method for detection of mutations in the QDPR gene, which may be useful for confirmatory DNA-based diagnosis, genetic counselling and prenatal diagnosis in DHPR deficiency.     

HIF-1α Plays a Critical Role in the Gestational Sidestream Smoke-Induced Bronchopulmonary Dysplasia in Mice

Rationale

Smoking during pregnancy increases the risk of bronchopulmonary dysplasia (BPD) and, in mice, gestational exposure to sidestream cigarette smoke (SS) induces BPD-like condition characterized by alveolar simplification, impaired angiogenesis, and suppressed surfactant protein production. Normal fetal development occurs in a hypoxic environment and nicotinic acetylcholine receptors (nAChRs) regulate the hypoxia-inducible factor (HIF)-1α that controls apoptosis and angiogenesis. To understand SS-induced BPD, we hypothesized that gestational SS affected alveolar development through HIF-1α.

Methods

Pregnant BALB/c mice were exposed to air (control) or SS throughout the gestational period and the 7-day-old lungs of the progeny were examined.

Results

Gestational SS increased apoptosis of alveolar and airway epithelial cells. This response was associated with increased alveolar volumes, higher levels of proapoptotic factors (FOXO3a, HIPK2, p53, BIM, BIK, and BAX) and the antiangiogenic factor (GAX), and lower levels of antiapoptotic factors (Akt-PI3K, NF-κB, HIF-1α, and Bcl-2) in the lung. Although gestational SS increased the cells containing the proangiogenic bombesin-like-peptide, it markedly decreased the expression of its receptor GRPR in the lung. The effects of SS on apoptosis were attenuated by the nAChR antagonist mecamylamine.

Conclusions

Gestational SS-induced BPD is potentially regulated by nAChRs and associated with downregulation of HIF-1α, increased apoptosis of epithelial cells, and increased alveolar volumes. Thus, in mice, exposure to sidestream tobacco smoke during pregnancy promotes BPD-like condition that is potentially mediated through the nAChR/HIF-1α pathway.     

A Unified Framework for Creating Domain Dependent Polarity Lexicons from User Generated Reviews

The exponential increase in the explosion of Web-based user generated reviews has resulted in the emergence of Opinion Mining (OM) applications for analyzing the users’ opinions toward products, services, and policies. The polarity lexicons often play a pivotal role in the OM, indicating the positivity and negativity of a term along with the numeric score. However, the commonly available domain independent lexicons are not an optimal choice for all of the domains within the OM applications. The aforementioned is due to the fact that the polarity of a term changes from one domain to other and such lexicons do not contain the correct polarity of a term for every domain. In this work, we focus on the problem of adapting a domain dependent polarity lexicon from set of labeled user reviews and domain independent lexicon to propose a unified learning framework based on the information theory concepts that can assign the terms with correct polarity (+ive, -ive) scores. The benchmarking on three datasets (car, hotel, and drug reviews) shows that our approach improves the performance of the polarity classification by achieving higher accuracy. Moreover, using the derived domain dependent lexicon changed the polarity of terms, and the experimental results show that our approach is more effective than the base line methods.     

Association of Household and Community Socioeconomic Position and Urbanicity with Underweight and Overweight among Women in Pakistan

Background

Similar to other developing countries, Pakistan is going through a rapid nutrition transition where shift from underweight to overweight and obesity is occurring. In this paper, we report on the relationship of household socioeconomic position (SEP), community SEP and urbanicity with under- and over-weight categories of BMI among Pakistani women.

Methods

We analyzed data on 4,767 women ages 15-49 years enrolled in a nationally representative Pakistan Demographic Health Survey (PDHS) conducted in 2012-13 that employed a multistage, stratified cluster sampling design. We assessed the association of urbanicity, household and community SEP derived from household assets and utilities, with categories of body mass index (BMI) using multinomial regression analysis where normal weight (BMI 18.6-22.5) was the reference category.

Results

Thirteen percent of women were underweight (BMI <18.5), 15% pre-overweight (BMI: 22.6-24.9), 25% overweight (BMI: 25.0–29.9) and 14% were obese (BMI≥30). Pre-overweight, overweight and obesity among women increased across household wealth quintiles (HWQs) in a graded fashion whereas there was no significant difference in underweight by household wealth. Women in urban areas were more likely to be obese. There was a pronounced increase in adjusted odds ratios (aORs) for overweight/obesity across HWQs within urban areas compared to rural areas. There was a steeper gradient in aORs for obesity from 1st to 5th HWQs in high income communities compared to the middle- and low income communities. In community-level analyses, communities in urban areas were more likely to have higher levels of obesity while in rural areas, especially in Sindh, more communities were more likely to have a higher level of underweight.

Conclusion

A shift to higher overweight and obesity than underweight in Pakistan is associated with high household and community wealth as well as living in urban areas. Clustering of obesity and underweight in distinct communities afford opportunity for tailored intervention programs.     

野生大豆抗感大豆孢囊线虫材料内生细菌多样性分析

【目的】对抗感野生大豆材料根内生细菌的多样性进行比较分析,为研究野生大豆内生细菌与大豆孢囊线虫之间的相互关系奠定基础。【方法】在野生大豆抗大豆孢囊线虫3号生理小种筛选基础上,利用扩增核糖体DNA限制性分析(Amplified ribosomal DNA restriction analysis,ARDRA)和16S rDNA克隆文库测序相结合的方法,对抗感野生大豆根系内生细菌多样性及群落结构进行分析。【结果】野生大豆根内生细菌分属于6大类群,其中变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)为优势类群,相对丰度分别为46.8%和13.6%,另外有少量的放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)、异常球菌-栖热菌门(Deincoccus-Thermus)和古细菌(Archaea),18.8%克隆序列与环境中未培养细菌的16S rDNA序列有较高的相似性。野生大豆高抗材料内生细菌的多样性比高感材料更为丰富,且抗感材料内生细菌优势菌群存在明显差异,中慢生根瘤菌(Mesorhizobium tamadayense)、肠杆菌(Enterobacter ludwigii)和巨大芽孢杆菌(Bacillus megaterium)为野生大豆高抗材料特有的可操作分类单元(Operational Taxonomic Units,OTUs)中的优势种群。【结论】研究结果表明抗感野生大豆根内生细菌的优势种群存在明显差异,而内生细菌的优势种群与大豆孢囊线虫的相互关系正在深入分析研究。     

Comparative assessment of Cladophora, Spirogyra and Oedogonium biomass for the production of fatty acid methyl esters

The use of alternative fuels for the mitigation of ecological impacts by use of diesel has been focus of intensive research. In the present work, algal oils extracted from cultivated biomass of Cladophora sp., Spirogyra sp. and Oedogonium sp. were evaluated for the lipase-mediated synthesis of fatty acid monoalkyl esters (FAME, biodiesel). To optimize the transesterification of these oils, different parameters such as the alkyl group donor, reaction temperature, stirring time and oil to alcohol ratio were investigated. Four different alcohols i.e. methanol, ethanol, n-propanol and n-butanol were tested as alkyl group donor for the biosynthesis FAME and methanol was found to be the best. Similarly, temperature 50 C and stirring time of 6 h were optimized for the transesterification of oils with methanol. The maximum biodiesel conversions from Cladophora (75.0%), Spirogyra (87.5%) and Oedogonium (92.0%) were obtained when oil to alcohol ratio was 1: 8.