Identification of sodC encoding periplasmic [Cu,Zn]-superoxide dismutase in Salmonella

Abstract sodC , encoding [Cu,Zn]-cofactored Superoxide dismutase, once thought to be virtually confined to eukaryotes, has now been described in many Gram-negative pathogens that have their primary niche of colonization in the upper respiratory tract. Their role in host-parasite interactive biology is unknown. We here show that members of the major human and animal enteric pathogenic species Salmonella harbour a version of sodC most closely resembling that found in Brucella abortus . The enzyme it encodes is a novel candidate determinant of virulence in Salmonella , an intracellular pathogen potentially exposed to toxic oxygen free radicals within its intracellular niche.     

Serum FSH, LH and testosterone in the male rhesus following prostaglandin injection.

Adult male rhesus were treated with PGE2, PGF2 alpha or the 13,14-dihydro-15-keto metabolite of PGE2 in a randomized crossover design. Serum concentrations of FSH, LH and testosterone were determined and compared to the respective values in the same uninjected animals. No significant changes were noted in controls or following the metabolite injection. FSH increased gradually for 4 hours after metabolite treatment. In contrast, injection of PGF2 alpha was followed by an abrupt (within 15 minutes) increase in LH and testosterone. FSH increased gradually in 2 of 3 treated animals. Injection of PGE2 was followed by a similar abrupt increase in LH concentration. This was not always associated with a significant increase in testosterone or FSH. These results demonstrate that injections of PGE2 or PGF2 alpha can change serum gonadotropin and testosterone concentrations in male rhesus monkeys, and that the effects of these two prostaglandins are qualitatively different.     

The cytoplasmic heme-binding protein (PhuS) from the heme uptake system of Pseudomonas aeruginosa is an intracellular heme-trafficking protein to the delta-regioselective heme oxygenase

The uptake and utilization of heme as an iron source is a receptor-mediated process in bacterial pathogens and involves a number of proteins required for internalization and degradation of heme. In the following report we provide the first in-depth spectroscopic and functional characterization of a cytoplasmic heme-binding protein PhuS from the opportunistic pathogen Pseudomonas aeruginosa. Spectroscopic characterization of the heme-PhuS complex at neutral pH indicates that the heme is predominantly six-coordinate low spin. However, the resonance Raman spectra and global fit analysis of the UV-visible spectra show that at all pH values between 6 and 10 three distinct species are present to varying degrees. The distribution of the heme across multiple spin states and coordination number highlights the flexibility of the heme environment. We provide further evidence that the cytoplasmic heme-binding proteins, contrary to previous reports, are not heme oxygenases. The degradation of the heme-PhuS complex in the presence of a reducing agent is a result of H2O2 formed by direct reduction of molecular oxygen and does not yield biliverdin. In contrast, the heme-PhuS complex is an intracellular heme trafficking protein that specifically transfers heme to the previously characterized iron-regulated heme oxygenase pa-HO. Surface plasmon resonance experiments confirm that the transfer of heme is driven by a specific protein-protein interaction. This data taken together with the spectroscopic characterization is consistent with a protein that functions to shuttle heme within the cell.     

Association of macro-level determinants with adolescent overweight and suicidal ideation with planning: A cross-sectional study of 21 Latin American and Caribbean Countries

BackgroundAdolescents and young people (10–24 years old) in the Latin America and the Caribbean (LAC) region represent approximately 25% of the region’s population. Since the 2008 global economic crisis, the pace of reduction in poverty and income inequality in the LAC region has stalled. The region is characterised by high levels of inequities and is also vulnerable to many natural disasters. Food systems are changing with increased availability and marketing of packaged and fast foods and sugar-sweetened drinks. Adolescence is a formative phase of the life course with multiple physical, emotional and social changes which can make them vulnerable to health problems. We assess the potential impact of macro-determinants, human and economic development as well as income inequality, on 2 top-ranking regional priorities for adolescent nutrition and mental health, using measures of overweight and suicidal ideation and planning which some have shown to be associated.Methods and findingsThe Global School-based Health Survey (GSHS) is a nationally representative self-administered, school-based survey. We examined overweight/obesity and suicidal ideation with planning by gross domestic product (GDP) per capita or human development index (HDI) in 10–19-year-old adolescents from 21 LAC countries between 2009 and 2013. Sample sizes varied from 943 in Anguilla to 27,988 in Argentina. A total of 55,295 adolescents had a measure of overweight/obesity status, and 59,061 adolescents reported about suicidal ideation with planning. There was equal representation by sex in the surveys (52% girls and 48% boys). A total of 28.8% of boys and 28.1% of girls had overweight/obesity, and 7.5% of boys and 17.5% of girls reported suicidal ideation with planning over the last 12 months. Adjusted for individual socioeconomic and risk behaviours, and relative to the highest GDP per capita tertile, the middle tertile was associated with 42% (95% confidence interval (CI) 59% to 17%, p = 0.003) and 32% (95% CI 60% to 5%, p = 0.023), and the lowest tertile with 40% (95% CI 55% to 19%, p = 0.001) and 46% (95% CI 59% to 29%, p < 0.001) lower chances of overweight/obesity for girls and boys, respectively. A similar positive effect was seen with HDI, with lowest chances of overweight in the lowest tertile compared with the highest tertile for both sexes. Overweight/obesity was positively related with suicidal ideation with planning for girls (odds ratio (OR) 1.12, 95% CI 1.02 to 1.22, p = 0.009) and weakly related for boys (OR 1.09, 95% CI 0.96 to 1.24, p = 0.182). In contrast to overweight/obesity status, suicidal ideation with planning was not related to macro-level indices despite both outcomes sharing common individual socioeconomic and risk behaviour correlates. Limitations include the dominance of Argentinians in the sample (40%), the exclusion of vulnerable adolescents who dropped out of school, and reporting bias due to stigma of mental health–related issues.ConclusionsThis study shows that economic and human development were positively associated with adolescent overweight/obesity but not with suicidal ideation with planning. We also observed an interconnectedness between overweight/obesity and suicide ideation with planning among girls. These findings highlight the importance of strategies that engage with both upstream and downstream determinants to improve adolescent nutrition and mental health.     

Grazing Rates in Euplotes mutabilis: Relationship between Particle Size and Concentration

Abstract Grazing behavior of both individual cells and populations of the marine hypotrich Euplotes mutabilis, a largely benthic ciliate that feeds on suspended particles, was studied using fluorescent latex microspheres. Microspheres of sizes 0.57-, 1.90-, 3.06-, 5.66-, and 10.0-μm diam were offered at concentrations from 10² to 10⁶ ml⁻¹. Their uptake in a ten-min period was determined. Food particles within such ranges of size and concentration are found under natural conditions. The ciliates ingested particles of all sizes offered. Uptake rates at all concentrations were dependent upon particle size, with 1.90- and 3.06-μm diam microspheres having the highest uptake rate in all cases. For all sizes, there was an increase in the percentage of feeding cells and in the uptake rate (the number of particles ingested cell⁻¹ h⁻¹), with increasing particle concentration. When uptake was expressed as the volume ingested, maximum values were obtained for 5.85-μm diam microspheres at a concentration of 10⁶ ml⁻¹. By taking a small number of large particles, present at a low concentration in the medium, a ciliate can ingest a greater biovolume than by taking a high number of small particles which are abundant in the medium. These results demonstrate that some ciliates can graze particles of a wide range of sizes. Also, its nutrition can be affected by changing ambient concentrations of different prey, both through effects on the proportion of feeding cells and through the relative food content of the particles. The data can also add to the understanding of food niche partitioning between species. At low particle concentrations, particularly, it is important to consider the behavior of individual ciliates as well as of the whole population. Received: 11 February 1997; Accepted: 21 October 1997     

Two novel protein-tyrosine kinases, each with a second phosphotransferase-related catalytic domain, define a new class of protein kinase.

The protein-tyrosine kinases (PTKs) are a burgeoning family of proteins, each of which bears a conserved domain of 250 to 300 amino acids capable of phosphorylating substrate proteins on tyrosine residues. We recently exploited the existence of two highly conserved sequence elements within the catalytic domain to generate PTK-specific degenerate oligonucleotide primers (A. F. Wilks, Proc. Natl. Acad. Sci. USA 86:1603-1607, 1989). By application of the polymerase chain reaction, portions of the catalytic domains of several novel PTKs were amplified. We describe here the primary sequence of one of these new PTKs, JAK1 (from Janus kinase), a member of a new class of PTK characterized by the presence of a second phosphotransferase-related domain immediately N terminal to the PTK domain. The second phosphotransferase domain bears all the hallmarks of a protein kinase, although its structure differs significantly from that of the PTK and threonine/serine kinase family members. A second member of this family (JAK2) has been partially characterized and exhibits a similar array of kinase-related domains. JAK1 is a large, widely expressed membrane-associated phosphoprotein of approximately 130,000 Da. The PTK activity of JAK1 has been located in the C-terminal PTK-like domain. The role of the second kinaselike domain is unknown.     

Excess Cardiovascular Risk Burden in Jamaican Women Does Not Influence Predicted 10-Year CVD Risk Profiles of Jamaica Adults: An Analysis of the 2007/08 Jamaica Health and Lifestyle Survey

Background

Black Caribbean women have a higher burden of cardiovascular disease (CVD) risk factors than their male counterparts. Whether this results in a difference in incident cardiovascular events is unknown. The aim of this study was to estimate the 10 year World Health Organization/International Society for Hypertension (WHO/ISH) CVD risk score for Jamaica and explore the effect of sex as well as obesity, physical activity and socioeconomic status on these estimates.

Methods and Findings

Data from 40–74 year old participants in the 2007/08 Jamaica Health and Lifestyle Survey were used. Trained interviewers administered questionnaires and measured anthropometrics, blood pressure, fasting glucose and cholesterol. Education and occupation were used to assess socioeconomic status. The Americas B tables were used to estimate the WHO/ISH 10 year CVD risk scores for the population. Weighted prevalence estimates were calculated. Data from 1,432 (450 men, 982 women) participants were analysed, after excluding those with self-reported heart attack and stroke. The women had a higher prevalence of diabetes (19%W;12%M), hypertension (49%W;47%M), hypercholesterolemia (25%W;11%M), obesity (46%W;15%M) and physical inactivity (59%W;29%M). More men smoked (6%W;31%M). There was good agreement between the 10-year cardiovascular risk estimates whether or not cholesterol measurements were utilized for calculation (kappa –0.61). While 90% had a 10 year WHO/ISH CVD risk of less than 10%, approximately 2% of the population or 14,000 persons had a 10 year WHO/ISH CVD risk of ≥30%. As expected CVD risk increased with age but there was no sex difference in CVD risk distribution despite women having a greater risk factor burden. Women with low socioeconomic status had the most adverse CVD risk profile.

Conclusion

Despite women having a higher prevalence of CVD risk factors there was no sex difference in 10-year WHO/ISH CVD risk in Jamaican adults.