Studies on Prevalence and Risk Factors for Hepatitis B Surface Antigen among Secondary School Students in North-central, Nigeria

Hepatitis B virus (HBV) Infection is one of the major global public health problems, with its attendant risks especially among the young adults. This study was therefore carried out to assess the sero-prevalence of hepatitis B surface antigen (HBsAg) and associated risk factors among students of a secondary school in Jagindi Tasha, Kaduna State, Nigeria. One hundred and ninety (190) apparently healthy students were screened and sera samples obtained were separated and analysed for HBsAg using a commercially available Enzyme Linked Immunosorbent Assay (ELISA)-based kit (Dialab). Information was obtained for risk factors using structured questionnaire. Out of the 190 samples screened, 35 (18.4%) were sero-positive. Subjects aged 13-15 years recorded 6.8% positivity (x2 = 1.084; p>0.05) and male subjects had 25.5% positivity compared to 10.9% positivity for females (x2 = 6.768; p<0.05). Risk factors such as blood transfusion was 32.0% among male subjects compared to 30.0% in females (x2 =18.07; p-value = 0.113). Furthermore, alcoholic consumption, the predominant lifestyle of the youths in this community was 20.0% among male subjects as compared to none in females. Unfortunately, the prevalence of HBV appears high among the studied population. This suggests that public awareness on the virus be accorded urgent attention, while vaccination programme should be improved in the community

Physical activity and nutrition intervention for Singaporean women aged 50 years and above: study protocol for a randomised controlled trial

The majority of the older Singaporean women aged 50 years and above are physically inactive and have unhealthy dietary habits, placing them at ‘high risk’ of non-communicable diseases (NCDs). The adoption of regular physical activity (PA) and a healthy diet are essential lifestyle behaviours to reduce this risk. This randomised controlled trial (RCT) involves the development, implementation and evaluation of a PA and nutrition programme for community-dwelling Singaporean women who currently attend recreational centres (RCs are public facilities supporting social leisure activities) in their local area. The intervention will be developed after conducting formative evaluation with RC attendees and managers through focus group discussions and pilot testing of resources (i.e. surveys, accelerometers, and health booklets). Programme ambassadors (trained, certified fitness instructors and nutritionists) will deliver all sessions in English and Mandarin; implement classes to meet participants’ varying needs; and conduct sessions at different times at convenient venues. Social Cognitive Theory (SCT) has been selected as the theoretical framework to inform intervention strategies as it explores the interactions of human behaviour with the environment and has been found to be valuable when developing behavioural change interventions particularly in older adults (J Gerontol B Psychol Sci Soc Sci 67B(1):18–26, 2012; Obesity Reviews 15(12):983–95, 2014). Its major construct, self-efficacy, is invaluable in achieving successful behaviour change, such as increasing levels of PA or improving dietary intake (Trials. 2017; https://doi.org/10.1186/s13063-016-1771-9 ; Psychol Health Med 18(6):714–24, 2013)

Racial Differences in the Effectiveness of Total Knee Arthroplasty (TKA) on Postoperative Pain and Function

Objective: African Americans are less likely than Caucasians to perceive TKA as an effective treatment option. We examined post-TKA pain and function by race, with and without adjusting for demographic and clinical factors on determining racial differences. Methods: We analyzed data from FORCE-TJR, a national cohort of TJR patients. Patients had primary and unilateral TKA surgeries 07/01/2011-12/31/2014, and completed surveys on demographic and clinical information, including a pre- and 6-month postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS). The KOOS pain and function scores ranged from 0-100 (higher=better). We examined baseline, 6-month, and 6-month change in pain and function by race, and estimated the association between race and outcomes, adjusting for demographic and clinical factors. Results: Analyses included 5028 white (63% female, 65% income\u3e45k; mean age of 67. BMI of 31) and 270 black patients (80% female, 39% income\u3e45k; mean age of 63, BMI of 34). At baseline, black compared with white patients reported worse knee pain (mean: 39vs.48), and poorer function (mean: 46vs.54). While all patients reported significant gains at 6-month post-surgery, black patients had lower postoperative pain (mean: 71vs.82) and function scores (mean: 73vs.84) than white patients. Although not statistically significant, black patients on average had lower 6-month change than white patients in pain -1.9 (95%CI: -4.4, 0.6) and function -1.6 (95%CI: -3.9, 0.7). Adjusting for covariates, racial differences were significantly more pronounced in change in pain -5.5 (95%CI: -8.3, -2.7) and function -5.6 (95%CI: -8.2, -3.0). Conclusions: TKAs were as effective in reducing pain and improving functions in blacks as in whites. Adjusting for certain demographic and clinical factors can impact assessment of racial differences and the effectiveness of TKA on postoperative outcomes, as black patients were very different from white patients on these important factors

Development and evaluation of a multiple-locus variable-number tandem-repeats analysis assay for subtyping Salmonella Typhi strains from sub-Saharan Africa

Purpose: Molecular epidemiological investigations of the highly clonal Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) are important in outbreak detection and in tracking disease transmission. In this study, we developed and evaluated a multiple-locus variable-number tandem-repeats (VNTR) analysis (MLVA) assay for characterization of S. Typhi isolates from sub-Saharan Africa. Methodology: Twelve previously reported VNTR loci were evaluated and an MLVA assay consisting of five polymorphic loci was adopted. The MLVA assay was developed for use on capillary electrophoresis systems by testing a collection of 50 S. Typhi isolates. This S. Typhi strain panel consisted of six outbreak related isolates and 44 epidemiologically unlinked isolates. Amongst these were nine S.Typhi haplotype H58 isolates. Results: The MLVA assay characterized the 50 isolates into 47 MLVA profiles while PFGE analysis of the same isolates revealed 34 pulsotypes. MLVA displayed higher discriminatory power (Simpson’s index of diversity (DI) 0.998 [95% confidence interval (CI) 0.995–1.000)] as compared to pulsed-field gel electrophoresis [Simpson’s DI 0.984 (95% CI 0.974–0.994)]. Conclusion: The MLVA assay presented in this study is a simple, rapid and more accessible tool that serves as a good alternative to other molecular subtyping methods for S. Typhi

The cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers: Results from the GET UP! Study

Background: The associations between sleep characteristics and adiposity in children under three years are not fully understood yet. Objective: The objective of the study is to examine the cross-sectional and prospective associations between sleep characteristics and adiposity in toddlers over a 12-month period. Methods: Participants were 202 toddlers from the GET-UP! Study. Sleep duration, sleep timing, and sleep variability were assessed using 24-hour accelerometry for seven consecutive days. Height and weight were measured, and BMI z scores were calculated. Linear mixed models were performed to examine the cross-sectional and prospective associations between sleep characteristics and adiposity, with adjustments for clustering effects and demographic factors. Results: Total sleep duration was negatively associated with higher adiposity cross-sectionally (B = −0.12; 95% CI: −0.23, −0.01;.033) but not prospectively (B = 0.01; 95% CI: −0.13, 0.10;.843). Nap duration was prospectively associated with higher levels of adiposity (B = 0.41; 95% CI: 0.14, 0.68;.003). Sleep variability and sleep timing were not associated with concurrent or subsequent adiposity. Conclusion: Although sleep duration is an important factor associated with obesity in toddlerhood, the potential effects of different types of sleep duration may vary. While longer total sleep duration may protect children from increasing adiposity, longer nap duration seems to be risk factor. As evidence in this age group is scarce, more research is needed to confirm this finding

Artificially Sweetened Beverages and the Response to the Global Obesity Crisis

Christopher Millett and colleagues argue that artificially sweetened beverages should not be promoted as part of a healthy diet

Increasing dominance of large lianas in Amazonian forests

Ecological orthodoxy suggests that old-growth forests should be close to dynamic equilibrium, but this view has been challenged by recent findings that neotropical forests are accumulating carbon and biomass, possibly in response to the increasing atmospheric concentrations of carbon dioxide. However, it is unclear whether the recent increase in tree biomass has been accompanied by a shift in community composition. Such changes could reduce or enhance the carbon storage potential of old-growth forests in the long term. Here we show that non-fragmented Amazon forests are experiencing a concerted increase in the density, basal area and mean size of woody climbing plants (lianas). Over the last two decades of the twentieth century the dominance of large lianas relative to trees has increased by 1.7–4.6% a year. Lianas enhance tree mortality and suppress tree growth, so their rapid increase implies that the tropical terrestrial carbon sink may shut down sooner than current models suggest. Predictions of future tropical carbon fluxes will need to account for the changing composition and dynamics of supposedly undisturbed forests

Topological Surface States Protected From Backscattering by Chiral Spin Texture

Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated by strong spin orbit coupling. These novel materials are distinguished from ordinary insulators by the presence of gapless metallic boundary states, akin to the chiral edge modes in quantum Hall systems, but with unconventional spin textures. Recently, experiments and theoretical efforts have provided strong evidence for both two- and three-dimensional topological insulators and their novel edge and surface states in semiconductor quantum well structures and several Bi-based compounds. A key characteristic of these spin-textured boundary states is their insensitivity to spin-independent scattering, which protects them from backscattering and localization. These chiral states are potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing. Here we use a scanning tunneling microscope (STM) to visualize the gapless surface states of the three-dimensional topological insulator BiSb and to examine their scattering behavior from disorder caused by random alloying in this compound. Combining STM and angle-resolved photoemission spectroscopy, we show that despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observation of spin-selective scattering demonstrates that the chiral nature of these states protects the spin of the carriers; they therefore have the potential to be used for coherent spin transport in spintronic devices.Comment: to be appear in Nature on August 9, 200

Laboratory-acquired infections of Salmonella enterica serotype Typhi in South Africa: phenotypic and genotypic analysis of isolates

BACKGROUND: Workers in clinical microbiology laboratories are exposed to a variety of pathogenic microorganisms. Salmonella species is among the most commonly reported bacterial causes of laboratory-acquired infections. We report on three cases of laboratory-acquired Salmonella enterica serotype Typhi (Salmonella Typhi) infection which occurred over the period 2012 to 2016 in South Africa. METHODS: Laboratory investigation included phenotypic and genotypic characterization of isolates. Phenotypic analysis included standard microbiological identification techniques, serotyping and antimicrobial susceptibility testing. Genotypic analysis included the molecular subtyping methodologies of pulsed-field gel electrophoresis analysis, multilocus sequence typing and whole-genome sequencing (WGS); with WGS data analysis including phylogenetic analysis based upon comparison of single nucleotide polymorphism profiles of isolates. RESULTS: All cases of laboratory-acquired infection were most likely the result of lapses in good laboratory practice and laboratory safety. The following critical issues were highlighted. There was misdiagnosis and misreporting of Salmonella Typhi as nontyphoidal Salmonella by a diagnostic laboratory, with associated public health implications. We highlight issues concerning the importance of accurate fluoroquinolone susceptibility testing and interpretation of results according to updated guidelines. We describe potential shortcomings of a single disk susceptibility screening test for fluoroquinolone susceptibility and suggest that confirmatory minimum inhibitory concentration testing should always be performed in cases of invasive Salmonella infections. These antimicrobial susceptibility testing issues resulted in inappropriate ciprofloxacin therapy which may have been responsible for failure in clearance of pathogen from patients. Salmonella Typhi capsular polysaccharide vaccine was not protective in one case, possibly secondarily to a faulty vaccine. CONCLUSIONS: Molecular subtyping of isolates proved effective to investigate the genetic relatedness of isolates. Molecular subtyping data interpreted together with epidemiological data allowed us to pinpoint the most likely sources for our cases of laboratory-acquired infection