Selenium abates manganese-induced striatal and hippocampal toxicity via abrogation of neurobehavioral deficits, biometal accumulation, oxidative stress, inflammation, and caspase-3 activation in rats.

Excessive exposure to manganese (Mn) is associated with neurotoxicity characterized by oxidative stress, inflammation, and apoptosis induction. Selenium (Se) has been shown to possess antioxidant, anti-inflammatory, and anti-apoptotic properties in humans and animals. The present study investigated the neuroprotective mechanism of Se in rats sub-chronically treated with Mn at 30 mg/kg body weight or orally co-treated with Se at 0.2 and 0.4 mg/kg body weight for 35 consecutive days. Locomotive and exploratory profiles were recorded and computed with the aid of ANY-Maze (a video-tracking software) for 5-min trial, in a novel apparatus. The ANY-Maze analysis showed that Se significantly (p < 0.05) abated Mn-induced locomotive impairment evidenced by increased in maximum speed, total time traveled, absolute turn angle, number of line crossing, rotation and forelimb grip and decreased total time immobile, grooming, and negative geotaxis as verified by the enhanced track plot density. Furthermore, the striatum and hippocampus of the rats were excised and the levels of Mn and Se, oxidative stress markers, proinflammatory cytokines including acetylcholinesterase and caspase-3 activities were assayed. The result shows that Se abates Mn-mediated accumulation of Mn. Also, Se ameliorated Mn-induced decrease in antioxidant enzymes as well as glutathione level and increase in acetylcholinesterase activity, lipid peroxidation, proinflammatory cytokines (i.e., interleukin (IL)-6, IL-1ß, tumor necrosis factor alpha), and caspase-3 activation in the striatum and hippocampus of the rats. Collectively, Se abated Mn-induced striatal and hippocampal toxicity via abrogation of neurobehavioral deficits, biometal accumulation, oxidative stress, inflammation, and caspase-3 activation in rats. Se may serve as a neuroprotective agent against Mn-mediated neurotoxicity.

Underground Gold Miner Exposure to Noise, Diesel Particulate Matter and Crystalline Silica Dust.

BACKGROUND: Respirable dust, diesel particulate matter, crystalline silica and noise pollution are the most common causes of health issues experienced by underground mine workers. Assessment of exposure levels in relation to standard regulatory body permissible levels is essential for the safety of mine workers. OBJECTIVES: The present study compared exposure levels of diesel particulate matter, crystalline silica dust and noise experienced across different underground mine worker job titles. METHODS: Subjective sampling was employed using gravimetric air samplers over an 8-hour time weighted average for two periods designated as period 1 (first half of the year) and period 2 (second half of the year). A comparative analysis of exposure levels between job titles and in relation to the National Institute for Occupational Safety and Health (NIOSH) permissible exposure levels (PELs) was performed. RESULTS: In the present study, 90% of the selected job titles were over-exposed to noise and 80% were over-exposed to diesel particulate matter. The highest exposures for crystalline silica dust and diesel particulate matter were found in the 40-49-year-old age group. CONCLUSIONS: The present study of exposure levels of diesel particulate matter, respirable dust, crystalline silica, and noise during underground gold mining demonstrates that better control mechanisms are needed to protect workers. PARTICIPANT CONSENT: Obtained. ETHICS APPROVAL: This study was approved by the Ethics Committee of the Kwame Nkrumah University of Science and Technology, Ghana. COMPETING INTERESTS: The authors declare no competing financial interests.

Patchy field sampling biases understanding of climate change impacts across the Arctic.

Effective societal responses to rapid climate change in the Arctic rely on an accurate representation of region-specific ecosystem properties and processes. However, this is limited by the scarcity and patchy distribution of field measurements. Here, we use a comprehensive, geo-referenced database of primary field measurements in 1,840 published studies across the Arctic to identify statistically significant spatial biases in field sampling and study citation across this globally important region. We find that 31% of all study citations are derived from sites located within 50 km of just two research sites: Toolik Lake in the USA and Abisko in Sweden. Furthermore, relatively colder, more rapidly warming and sparsely vegetated sites are under-sampled and under-recognized in terms of citations, particularly among microbiology-related studies. The poorly sampled and cited areas, mainly in the Canadian high-Arctic archipelago and the Arctic coastline of Russia, constitute a large fraction of the Arctic ice-free land area. Our results suggest that the current pattern of sampling and citation may bias the scientific consensuses that underpin attempts to accurately predict and effectively mitigate climate change in the region. Further work is required to increase both the quality and quantity of sampling, and incorporate existing literature from poorly cited areas to generate a more representative picture of Arctic climate change and its environmental impacts.

Historical epidemiology of hepatitis C virus in select countries-volume 4.

Due to the introduction of newer, more efficacious treatment options, there is a pressing need for policy makers and public health officials to develop or adapt national hepatitis C virus (HCV) control strategies to the changing epidemiological landscape. To do so, detailed, country-specific data are needed to characterize the burden of chronic HCV infection. In this study of 17 countries, a literature review of published and unpublished data on HCV prevalence, viraemia, genotype, age and gender distribution, liver transplants and diagnosis and treatment rates was conducted, and inputs were validated by expert consensus in each country. Viraemic prevalence in this study ranged from 0.2% in Hong Kong to 2.4% in Taiwan, while the largest viraemic populations were in Nigeria (2 597 000 cases) and Taiwan (569 000 cases). Diagnosis, treatment and liver transplant rates varied widely across the countries included in this analysis, as did the availability of reliable data. Addressing data gaps will be critical for the development of future strategies to manage and minimize the disease burden of hepatitis C.

Strategies to manage hepatitis C virus infection disease burden-Volume 4.

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 17 countries in Africa, Asia, Europe, Latin America and the Middle East, and interventions for achieving the Global Health Sector Strategy on viral hepatitis targets-"WHO Targets" (65% reduction in HCV-related deaths, 90% reduction in new infections and 90% of infections diagnosed by 2030) were considered. Scaling up treatment and diagnosis rates over time would be required to achieve these targets in all but one country, even with the introduction of high SVR therapies. The scenarios developed to achieve the WHO Targets in all countries studied assumed the implementation of national policies to prevent new infections and to diagnose current infections through screening.

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm: Volume 4.

Factors influencing the morbidity and mortality associated with viremic hepatitis C virus (HCV) infection change over time and place, making it difficult to compare reported estimates. Models were developed for 17 countries (Bahrain, Bulgaria, Cameroon, Colombia, Croatia, Dominican Republic, Ethiopia, Ghana, Hong Kong, Jordan, Kazakhstan, Malaysia, Morocco, Nigeria, Qatar and Taiwan) to quantify and characterize the viremic population as well as forecast the changes in the infected population and the corresponding disease burden from 2015 to 2030. Model inputs were agreed upon through expert consensus, and a standardized methodology was followed to allow for comparison across countries. The viremic prevalence is expected to remain constant or decline in all but four countries (Ethiopia, Ghana, Jordan and Oman); however, HCV-related morbidity and mortality will increase in all countries except Qatar and Taiwan. In Qatar, the high-treatment rate will contribute to a reduction in total cases and HCV-related morbidity by 2030. In the remaining countries, however, the current treatment paradigm will be insufficient to achieve large reductions in HCV-related morbidity and mortality.

Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient.

Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems.

Nutrient fluxes from insect herbivory increase during ecosystem retrogression in boreal forest.

Ecological theory, developed largely from ungulates and grassland systems, predicts that herbivory accelerates nutrient cycling more in productive than unproductive systems. This prediction may be important for understanding patterns of ecosystem change over time and space, but its applicability to other ecosystems and types of herbivore remain uncertain. We estimated fluxes of nitrogen (N) and phosphorus (P) from herbivory of a common tree species (Betula pubescens) by a common species of herbivorous insect along a -5000-yr boreal chronosequence. Contrary to established theory, fluxes of N and P via herbivory increased along the chronosequence despite a decline in plant productivity. The herbivore-mediated N and P fluxes to the soil are comparable to the main alternative pathway for these nutrients via tree leaf litterfall. We conclude that insect herbivores can make large contributions to nutrient cycling even in unproductive systems, and influence the rate and pattern of ecosystem development, particularly in systems with low external nutrient inputs.

'Older women', customary obligations and orphan foster caregiving: the case of queen mothers in Manya Klo, Ghana.

Female orphan caregivers in countries heavily affected by HIV in sub-Saharan Africa are often presented as a homogenous group of vulnerable 'older women' that struggles to support orphans. There is a dearth of data on the different kinds of women and how their social characteristics impact their survival strategies and caregiving responsibilities. This study examines the link between the social characteristics of queen mothers in Manya Klo in Ghana and their roles as caregivers. The research findings suggest that queen mothers have become the primary caregivers of orphans, even though they do not have the wherewithal to provide for these orphans. The lack of kin support to queen mothers exacerbates their physical and economic vulnerabilities. They engage in less dignifying economic activities and pay less attention to their own needs in order to meet their customary obligations as orphan caregivers. The growing influence of queen mothers as caregivers for orphans, however, is a reflection of some of the changes that are occurring in customary foster care arrangements. Policy makers and interventionists require in depth understanding of queen mothers and their peculiar circumstances in order to strengthen their roles as leaders and caregivers.

Travelling Companions: Emerging Diseases of People, Animals and Plants Along the Malawi-Mozambique Border.

Humans, animals and plants suffer from similar types of diseases (e.g., fungal, viral etc.). These can "emerge" as new diseases by expanding their geographical range or by jumping species (from plants to plants, or from animals to humans). Emerging diseases place an additional burden on developing countries which are often struggling to manage the diseases they already have. New diseases spread through weather, insects or other vectors, or by the movement of people, animals or goods. This study examines the role of cross-border travel in the spread of diseases. A survey of travelers and of residents along the Malawi-Mozambique border found that most cross it frequently and that they rarely travel empty-handed, often taking plants and animals with them. People also cross borders seeking medical attention. Attempting to limit travel would hamper an already struggling economy, where many people make a living by producing, processing or transporting plants and animals for food. Cross border travel per se may pose slight danger for the spread of diseases, if governments can collaborate on sharing information about the status of diseases within their border.

'Haptoglobin concentrations in preterm and term newborns'.

OBJECTIVE: To measure systemic haptoglobin (HPT) concentrations from birth in preterm (PT) and T newborns. To compare HPT in newborns without hemolysis or infection with values in bacteremic newborns. STUDY DESIGN: HPT was measured using enzyme-linked immunosorbent assay in 30 PT and 28 T newborns without hemolysis or infection at birth (cord blood), on days of life 2 to 4, and at 1 to 2 weeks of life. Concentrations were measured in eight additional newborns with bacteremia. Wilcoxon-Mann-Whitney test was used for comparisons. RESULT: HPT concentrations were consistently measurable from birth in PT and T neonates. Values were significantly greater in 2- to 4-day-old PT and T newborns than in newborns at birth (P<0.01). Bacteremic newborns had higher HPT concentrations than newborns without infection (P=0.033). CONCLUSION: HPT is detectable from birth in PT and T newborns. HPT concentrations increase in bacteremic newborns. HPT levels may have clinical utility in the evaluation of neonatal sepsis.

Thermal defense of extremely low gestational age newborns during resuscitation: exothermic mattresses vs polyethylene wrap.

OBJECTIVE: The purpose of this study was to assess the effectiveness of thermal warming mattresses compared with wrapping in a polyethylene sheet during resuscitation in extremely low gestational age newborns (ELGANs) in preventing admission hypothermia in the neonatal intensive care unit. STUDY DESIGN: Patients delivered between 24 and 28 weeks gestation and ≤1250 g were eligible for this prospective, randomized study. In the delivery room, the resuscitation team opened a sealed opaque envelope for treatment group assignment to either the wrap or the sodium acetate mattress group. Resuscitation followed protocols recommended by the Neonatal Resuscitation Program. The primary outcome for this study was comparison of axillary temperatures recorded at the time of neonatal intensive care unit admission between the two groups. RESULT: Thirty-nine patients were enrolled in the study. The mattress group's mean admission temperature was 36.5±0.67, whereas the plastic wrap group's was 36.1±0.66 (P=0.0445). CONCLUSION: Thermal mattresses improved admission temperature for ELGANs over plastic wrap. Although both plastic wrap and thermal mattresses improve the thermal status of ELGANs, all current interventions fall short of truly protecting all these vulnerable patients from thermal stress.

Decreased use of cervical spine clearance in blunt trauma: the implication of the injury mechanism and distracting injury.

BACKGROUND: Cervical spine injury (CSI) can be ruled out based on clinical examination and no X-ray is required if patient is awake, alert, and examinable. This is known as a clinical clearance (CC). Clinicians have decreased the use and reliance of CC and relied more upon X-ray, especially now that computerized tomography (CT) is fast and readily available. The objective of this study was to identify clinical factors, in particular, the injury mechanism and the distracting injuries, which may be associated with CSI. The knowledge may help to improve the use of CC. METHODS: We retrospectively reviewed the records of all blunt trauma patients who were awake, alert, and examinable, with a Glasgow Coma Scale of 14-15, and who were admitted to our Level 1 Trauma Center during January 1 to December 31, 2005. We excluded patients who presented with gross neurological deficit or who died within 72 h. From the chart review, we collected the demographics; the injury severity score (ISS); the injury mechanism; the presence of distracting injuries (DI) which were defined as bony fractures (divided into upper body, lower body, or both); and the radiographs obtained. Patients who did not receive CC underwent a 3-view plain film X-ray, with or without CT scan. We then divided the group into those with CSI (Case) and those without (Control). We compared the two group variables and performed a multiple logistic regression analysis to identify clinical factors associated with CSI. Statistical significance was accepted with p-value <0.05. RESULTS: Of the 985 patients evaluated, only 179 (18%) received CC. The remaining did not receive CC and went on to have radiographs. Of these, 76 were diagnosed CSI (Case). On a univariate analysis, the ISS, a motor vehicle collision (MVC) with rollover; MVC with rollover and ejection, the absence of DI, and a lower-body DI were significantly associated with CSI. However, on a multivariate analysis, only an MVC with rollover (odds ratio [OR], 2.326; 95% confidence interval [CI], 1.36-3.97) and a lower-body distracting injury (OR, 0.20; 95% CI, 0.07-0.55) were significantly associated with CSI. CONCLUSION: The injury mechanism of MVC with rollover may prevent clinicians from utilizing CC, while the presence of a lower-body DI should not. A future and prospective study is needed to better understand the role of the injury mechanism and the distracting injury in relation to CSI.

Plasmid-coded DNA fragment developed as a specific gene probe for the identification of enteroaggregative Escherichia coli.

Enteroaggregative Escherichia coli (EAggEC) is a recently discovered diarrhoeal pathogen implicated as a cause of persistent diarrhoea in children. EAggEC strains exhibit a characteristic pattern of adherence when incubated with HEp-2 cells. Because of the difficulty in identifying this group of bacteria, the epidemiological significance of this pathogen as a diarrhoeal agent has not been fully realised. A gene probe was developed from the 60-MDa plasmid associated with EAggEC strains that encodes the genes for adherence and fimbriae. The sensitivity of the gene probe was 93% and the specificity 98% for detecting EAggEC isolates and is potentially useful for diagnostic and epidemiological studies.

Nonradioactive polynucleotide gene probe assay for the detection of three virulence toxin genes in diarrhoeal stools.

The present study describes a nonisotopic DNA-DNA hybridization assay for the detection of enterotoxigenic Escherichia coli (ETEC) in which the probes were labelled with the hapten molecule digoxigenin and after hybridization, DNA hybrids were detected by antidigoxigenin alkaline phosphatase conjugate. A blinded study carried out on a battery of enterotoxigenic and nonenterotoxigenic Esch. coli by dig-probe hybridization assay were compared with the results of a radiolabelled toxin gene probe hybridization assay (performed earlier). The three digoxigenin labelled probes gave a 100 per cent specificity and sensitivities of 95.45, 100 and 100 per cent for LT, STh and STp respectively. These results were comparable to those with the radioactive probes.