Assaying Environmental Nickel Toxicity Using Model Nematodes

Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species

Health-related quality of life dynamics of HIV-positive South African women up to ART initiation : evidence from the CAPRISA 002 acute infection cohort study.

CAPRISA, 2014.Few studies have investigated the long-term dynamics in health-related quality of life (HRQoL) among HIV-positive persons from acute infection. From 2004, 160 women were enrolled into the CAPRISA 002 Acute Infection study at two sites in the province of KwaZulu-Natal and underwent 3–6 monthly HRQoL assessments using the functional assessment of HIV infection (FAHI) instrument. Overall and 5 sub-scale FAHI scores [physical well-being (PWB), emotional well-being (EWB), functional and global well-being (FGWB), social well-being (SWB) and cognitive functioning (CF)] were calculated up to antiretroviral therapy (ART) initiation and scores at enrollment were compared to the acute, early and established infection phases. Mixed-effects regression models adjusting for behavioral and clinical factors were applied to assess HRQoL trends and the proportion of women meeting minimally important differences was calculated. Our analyses revealed that overall/sub-scale scores improved over time, except from PWB and CF. A higher educational status, contraceptive use and a higher BMI were the strongest predictors of higher overall/sub-scale FAHI scores. CD4 count and HIV viral load were strongly associated with PWB and CF, but not overall FAHI and other sub-scales. Women newly diagnosed with acute HIV infection face profound HRQoL challenges. While early ART delivery may be important for PWB and CF, factors such as education, contraception provision and good nutritional status should be promoted to maximize HRQoL in HIV positive individuals

The Effect of a Medium-Term Activity- and Diet-Induced Energy Deficit on Subjective Appetite Sensations in Obese Children

Objective: To assess the subjective appetite responses to an imposed activity- and diet-induced energy deficit during a residential intervention programme for obese children. Design: A 6-week intervention of fixed, reduced dietary intake and 6 h/day of skill-based physical activity while resident in a weight loss camp. Subjects: Thirty-eight obese (mean body mass index (BMI)=34.9 kg m-2) boys and girls (mean age 13.9 1.57). Measurements: An electronic appetite rating system (EARS) was used to periodically measure subjective appetite sensations at the start (WK1) and at the end (WK6) of the camp. Subjective ratings of hunger and fullness were compared at the start and end of 6 weeks of an activity- and diet-induced-based weight loss intervention. Results: At the end of the 6 weeks, the children had lost 8.4 kg in body mass. The diurnal profiles of subjective appetite sensations demonstrated clear oscillations in hunger and fullness. There was a significant increase in hunger (P<0.0001) and decrease in fullness (P<0.005) at the end (WK6) of the medium-term energy deficit. In WK6, morning ratings of hunger were higher than in WK1 (P<0.005) and the fixed energy evening meal induced a lower suppression of hunger (P<0.02). Conclusion: A programme of fixed, reduced-dietary intake combined with an activity and behavioural programme was successful at inducing a significant reduction in body mass in obese children. Subjective sensations of appetite were sensitive to a medium-term negative energy balance and weight loss. These data are essential as we continue to evolve methods of treatment for overweight and obese children

Spontaneous activity responses to exercise in males and females

This study examines the impact of a short-term exercise programme, prescribed on the basis of current exercise recommendations, on energy balance in males and females to assess whether this type of exercise induces compensatory changes in spontaneous activity energy expenditure (SAEE) and energy intake (EI). Individuals were monitored for 16 days, 8 days of habitual physical activity (C) and 8 days when exercise was imposed (E). Total energy expenditure (TEE) was calculated from individual relationships of O2 and CO2 to heart rate (HR) records of HR and physical activity obtained during waking hours of the C and E periods and basal metabolic rate (BMR) measurements (Deltatrac System, Datex Instrumentation). Changes in nude body mass (BM) were estimated by using a digital scale (Sartorius AG, Gottigen, Germany). Laboratory and free-living. Eight lean females (body fat: 17.54.5%) and eight males of similar percentage body fat participated in this study. All subjects were Caucasian and aged between 20 and 25 years. During the E period, a supervised exercise session was conducted every second day, each consisting of a total net energy expenditure of 2092 kJ+BMR at 90% lactate threshold. During the E period, TEE was higher than C in males and females (exercise: 95.213.9, 78.315.9 MJ; control: 82.410.4, 68.816.7 MJ, respectively; P<0.00; P=0.02). SAEE, calculated as TEE minus the energy expended during exercise, was not significantly different between C (males: 82.44.8 MJ; females: 68.87.6 MJ) and E (males: 86.86.3 MJ; females: 70.07.2 MJ) periods in either gender. Males showed no change in BM over the C (pre-intervention: 83.47.2 kg; post-intervention: 83.16.8 kg) or E (pre-intervention: 83.46.8 kg; post-intervention: 83.46.8 kg) periods. Females' BM over the C period did not alter (pre-intervention: 63.32.8 kg; post-intervention 63.73.1 kg); however, there was a significant decrease (P<0.00) in BM over the E period (pre-intervention: 63.02.7 kg; post-intervention: 62.42.7 kg). The exercise programme was achieved in males and females without any impact on SAEE. Therefore, differences between genders in relation to BM reduction can be explained by differences in the EI response to exercise