Hepatic and neurobiological effects of foetal and breastfeeding and adulthood exposure to methylmercury in Wistar rats

Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups. Control group received mineral oil; The simple exposure (SE) group was exposed only in adulthood (0.5 mg/kg/day); and double exposure (DE) was pre-exposed to MeHg 0.5 mg/kg/day during pregnancy and breastfeeding (±40 days) and re-exposed to MeHg for 45 days from day 100. After, we evaluated possible abnormalities. Behavioral and biochemical parameters in liver and occipital cortex (CO), markers of liver injury, redox and AKT/GSK3β/mTOR signaling pathway. Our results showed that both groups treated with MeHg presented significant alterations, such as decreased locomotion and exploration and impaired visuospatial perception. The rats exposed to MeHg showed severe liver damage and increased hepatic glycogen concentration. The MeHg groups showed significant impairment in redox balance and oxidative damage to liver macromolecules and CO. MeHg upregulated the AKT/GSK3β/mTOR pathway and the phosphorylated form of the Tau protein. In addition, we found a reduction in NeuN and GFAP immunocontent. These results represent the first approach to the hepatotoxic and neural effects of foetal and adult MeHg exposure.

Using a novel climate-water conflict vulnerability index to capture double exposures in Lake Chad

Climate variability is amongst an array of threats facing agricultural livelihoods, with its effects unevenly distributed. With resource conflict being increasingly recognised as one significant outcome of climate variability and change, understanding the underlying drivers that shape differential vulnerabilities in areas that are double-exposed to climate and conflict has great significance. Climate change vulnerability frameworks are rarely applied in water conflict research. This article presents a composite climate-water conflict vulnerability index based on a double exposure framework developed from advances in vulnerability and livelihood assessments. We apply the index to assess how the determinants of vulnerability can be useful in understanding climate variability and water conflict interactions and to establish how knowledge of the climate-conflict linked context can shape interventions to reduce vulnerability. We surveyed 240 resource users (farmers, fishermen and pastoralists) in seven villages on the south-eastern shores of Lake Chad in the Republic of Chad to collect data on a range of exposure, sensitivity and adaptive capacity variables. Results suggest that pastoralists are more vulnerable in terms of climate-structured aggressive behaviour within a lake-based livelihoods context where all resource user groups show similar levels of exposure to climate variability. Our approach can be used to understand the human and environmental security components of vulnerability to climate change and to explore ways in which conflict-structured climate adaptation and climate-sensitive conflict management strategies can be integrated to reduce the vulnerability of populations in high-risk, conflict-prone environments.

Ditch the pinch: bilateral exposure injuries during subcutaneous injection

BACKGROUND

Subcutaneous injection into an elevated skin fold poses a risk of "bilateral exposure" injury whereby the needle pierces the opposite side of a skin fold and subsequently enters the tissue of the health care worker (HCW).

METHODS

Retrospective review was conducted examining the Exposure Prevention Information Network (EPINet) needlestick surveillance data. Data from 2,402 injuries occurring during subcutaneous injection were included for analysis. Descriptive data, statistical comparisons, and a logistic regression model reporting relative risk are provided.

RESULTS

Eighty-five bilateral exposure injuries were identified between 2000 and 2009, representing 3.5% (n/N=85/2,402) of all injection-related percutaneous injuries. 65.4% Of the variance in bilateral exposure injury occurrence is explained through examination of the following: (1) manual elevation ("pinching") subcutaneous tissue prior to injection; (2) thin/emaciated patient; (3) injection of insulin; (4) injection of heparin; (5) injection of enoxaparin (Lovenox); (6) if a safety device was used; and (7) whether the health care worker was wearing gloves at the time of the injury (χ(2)7 = 424.2; P<.01).

CONCLUSION

Manual tissue elevation should be avoided to minimize the risk of bilateral exposure injuries.