Extended Duration Infusion of Hydroxocobalamin for Vasoplegic Rescue in Septic Shock

Nitric oxide (NO) is a gaseous signaling molecule and a key endogenous mediator of vascular tone. Hydroxocobalamin (HCB) affects NO-mediated vasoplegia as (1) a direct inhibitor of nitric oxide synthase (NOS), thereby decreasing its production, and (2) by binding directly to NO and acting as a scavenger. HCB has been increasingly used in the treatment of refractory vasoplegia, particularly in cardiac surgery and liver transplant patients. Sepsis and septic shock are characterized by an increase in inducible NOS expression and activity with excessive NO production, resulting in endothelial dysfunction and profound systemic vasodilation. Therefore, a careful sustained reduction in NO burden represents a potential therapeutic target. Here, we present a case of refractory septic shock, which resolved after an extended duration infusion of high-dose HCB. We hope to foster further exploration regarding the safety, dosing, and efficacy of HCB when administered for vasopressor refractory septic shock.

Spatial and temporal trends of the Stockholm Convention POPs in mothers' milk -- a global review

Persistent organic pollutants (POPs) have been of environmental and health concern for more than half a century and have their own intergovernmental regulation through the Stockholm Convention, from 2001. One major concern is the nursing child's exposure to POPs, a concern that has led to a very large number of scientific studies on POPs in mothers' milk. The present review is a report on the assessment on worldwide spatial distributions of POPs and of their temporal trends. The data presented herein is a compilation based on scientific publications between 1995 and 2011. It is evident that the concentrations in mothers' milk depend on the use of pesticides and industrial chemicals defined as POPs. Polychlorinated biphenyls (PCBs) and "dioxins" are higher in the more industrialized areas, Europe and Northern America, whereas pesticides are higher in Africa and Asia and polybrominated diphenyl ethers (PBDEs) are reported in higher concentrations in the USA. POPs are consequently distributed to women in all parts of the world and are thus delivered to the nursing child. The review points out several major problems in the reporting of data, which are crucial to enable high quality comparisons. Even though the data set is large, the comparability is hampered by differences in reporting. In conclusion, much more detailed instructions are needed for reporting POPs in mothers' milk. Temporal trend data for POPs in mothers' milk is scarce and is of interest when studying longer time series. The only two countries with long temporal trend studies are Japan and Sweden. In most cases, the trends show decreasing concentrations of POPs in mothers' milk. However, hexabromocyclododecane is showing increasing temporal concentration trends in both Japan and Sweden.

Placental transfer of persistent organic pollutants: a preliminary study on mother-newborn pairs

The aim of this study was to characterize the placental transfer of some environmental pollutants, and to explore the possibility of quantitatively predicting in utero exposure to these contaminants from concentrations assessed in maternal blood. Levels of toxic substances such as pesticides (p,p'-DDE, β-HCH, and HCB), polychlorinated biphenyls (PCBs), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA) were determined in serum samples of 38 pregnant women living in Rome and in samples of cord blood from their respective newborns. The study was carried out in the years 2008-2009. PCB mean concentrations in maternal serum and cord serum ranged from 0.058 to 0.30, and from 0.018 to 0.064 ng/g · fw respectively. Arithmetic means of PFOS and PFOA concentrations in mothers and newborns were 3.2 and 1.4 ng/g · fw, and 2.9 and 1.6 ng/g · fw. A strong correlation was observed between concentrations in the maternal and the foetal compartment for PFOS (Spearman r = 0.74, p < 0.001), PFOA (Spearman r = 0.70, p < 0.001), PCB 153 (Spearman r = 0.60, p < 0.001), HCB (Spearman r = 0.68, p < 0.001), PCB 180 (Spearman r = 0.55, p = 0.0012), and p,p'-DDE (Spearman r = 0.53, p = 0.0099). A weak correlation (p < 0.1) was observed for PCBs 118 and 138.

Persistent organic pollutants and type 2 diabetes: a prospective analysis in the nurses' health study and meta-analysis

BACKGROUND

Prospective data regarding persistent organic pollutants (POPs) and risk of type 2 diabetes (T2D) are limited, and the results for individual POPs are not entirely consistent across studies.

OBJECTIVES

We prospectively examined plasma POP concentrations in relation to incident T2D and summarized existing evidence in a meta-analysis.

METHODS

Plasma polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and hexachlorobenzene (HCB) concentrations were measured in 1,095 women who were free of diabetes at blood draw in 1989-1990 and participated in two case-control studies in the Nurses' Health Study. We identified 48 incident T2D cases through 30 June 2008. We conducted a literature search in PubMed and EMBASE through December 2011 to identify prospective studies on POPs in relation to diabetes. We used a fixed-effects model to summarize results.

RESULTS

After multivariable adjustment, plasma HCB concentration was positively associated with incident T2D [pooled odds ratio (OR) 3.59 (95% CI: 1.49, 8.64, ptrend = 0.003) comparing extreme tertiles]. Other POPs were not significantly associated with diabetes. After pooling our results with those of six published prospective studies that included 842 diabetes cases in total, we found that HCB and total PCBs both were associated with diabetes: the pooled ORs were 2.00 (95% CI: 1.13, 3.53; I2 = 21.4%, pheterogeneity = 0.28) and 1.70 (95% CI: 1.28, 2.27; I2 = 16.3%, pheterogeneity = 0.30) for HCB and total PCBs, respectively.

CONCLUSIONS

These findings support an association between POP exposure and the risk of T2D.

Serum concentrations of organochlorine pesticides and growth among Russian boys

BACKGROUND

Limited human data suggest an association of organochlorine pesticides (OCPs) with adverse effects on children's growth.

OBJECTIVE

We evaluated the associations of OCPs with longitudinally assessed growth among peripubertal boys from a Russian cohort with high environmental OCP levels.

METHODS

A cohort of 499 boys enrolled in the Russian Children's Study between 2003 and 2005 at 8-9 years of age were followed prospectively for 4 years. At study entry, 350 boys had serum OCPs measured. Physical examinations were conducted at entry and annually. The longitudinal associations of serum OCPs with annual measurements of body mass index (BMI), height, and height velocity were examined by multivariate mixed-effects regression models for repeated measures, controlling for potential confounders.

RESULTS

Among the 350 boys with OCP measurements, median serum hexachlorobenzene (HCB), β-hexachlorocyclohexane (βHCH), and p,p´-dichlorodiphenyldichloroethylene (p,p´-DDE) concentrations were 159 ng/g lipid, 168 ng/g lipid, and 287 ng/g lipid, respectively. Age-adjusted BMI and height z-scores generally fell within the normal range per World Health Organization standards at entry and during follow-up. However, in adjusted models, boys with higher serum HCB, βHCH, and p,p´-DDE had significantly lower mean [95% confidence interval (CI)] BMI z-scores, by -0.84 (-1.23, -0.46), -1.32 (-1.70, -0.95), and -1.37 (-1.75, -0.98), respectively, for the highest versus lowest quintile. In addition, the highest quintile of p,p´-DDE was associated with a significantly lower mean (95% CI) height z-score, by -0.69 (-1.00, -0.39) than that of the lowest quintile.

CONCLUSIONS

Serum OCP concentrations measured at 8-9 years of age were associated with reduced growth, particularly reduced BMI, during the peripubertal period, which may affect attainment of optimal adult body mass and height.

Levels of persistent organic pollutant and their predictors among young adults

Exposure to persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethane (p,p'-DDE), and hexachlorobenzene (HCB) continues to be of concern due to their ubiquitous distribution and high persistence. Current toxicant body burden is still a primary concern within the Akwesasne Mohawk Nation since other studies conducted within the community have shown relationships between these POPs and endocrine disruption. In this article we describe the levels of these toxicants in young adults of the Akwesasne Mohawk Nation between the ages of 17 and 21 years of age (mean age 18.1 years), and investigate potential influences of their current body burden. Seventeen congeners in fourteen chromatographic peaks were detected in 50% or more of the individuals sampled (geometric mean [GM] of the sum of these congeners=0.43 ppb). Congeners 118, 138[+163+164] and 153 had the highest rate of detection (≥98%) within the Akwesasne young adults. Of the other organochlorines, HCB (GM=0.04 ppb) and p,p'-DDE (GM=0.38 ppb) were found in 100% and 99% of the sample respectively. Significantly higher levels of PCBs were found among individuals who were breastfed as infants, were first born, or had consumed local fish within the past year. When compared to levels of p,p'-DDE, HCB, and 13 specific congeners reported by the CDC for youth between the ages of 12 and 19 years, the geometric means of several congeners (CBs 99, 105, 110, and 118) among the Akwesasne were higher than the reported CDC 90th percentile. In contrast, levels of CB 28 in Akwesasne young adults were ~50% or less than those of the CDC cohort. p,p'-DDE and HCB levels were generally higher in the CDC cohort (GM of 0.516 and 0.065 ppb, respectively for Mohawks vs. 2.51 and 0.123, respectively, for CDC). Concentrations of non-persistent PCBs among this sample of Akwesasne young adults were higher than those reported by the CDC suggesting continued exposure, but lower than those associated with severe contamination. Additional research into the concentration trends of individual PCB congeners within Akwesasne youth and young adults is warranted to further improve our insight into the determinants and influences of organochlorine concentrations within members of the Akwesasne community.

Exposure to hexachlorobenzene during pregnancy and children's social behavior at 4 years of age

BACKGROUND

Hexachlorobenzene (HCB) is an organochlorine chemical that has been used in agriculture and industrial processes. Behavioral impairment after HCB exposure has been described in animal models, but little information is available in humans.

OBJECTIVES

Our goal was to study the association of prenatal exposure to HCB with the social behavior of preschool children.

METHODS

Two birth cohorts in Ribera d'Ebre and Menorca (Spain) were set up between 1997 and 1999 (n = 475). The California Preschool Social Competence Scale and the Attention-Deficit Hyperactivity Disorder (ADHD) were scored by each 4-year-old child's teacher. Organochlorine compounds were measured in cord serum. Children's diet and parental sociodemographic information were obtained through questionnaire.

RESULTS

Children with concentrations of HCB > 1.5 ng/mL at birth had a statistically significant increased risk of having poor Social Competence [relative risk (RR) = 4.04; 95% confidence interval (CI), 1.76-9.58] and ADHD (RR = 2.71; 95% CI, 1.05-6.96) scores. No association was found between HCB and the cognitive and psychomotor performance of these children.

CONCLUSIONS

Prenatal exposure to current concentrations of HCB in Spain is associated with a decrease in the behavioral competence at preschool ages. These results should be considered when evaluating the potential neurotoxicologic effects of HCB.

Do organohalogen contaminants contribute to histopathology in liver from East Greenland polar bears (Ursus maritimus)?

In East Greenland polar bears (Ursus maritimus), anthropogenic organohalogen compounds (OHCs) (e.g., polychlorinated biphenyls, dichlorodiphenyltrichloroethane, and polybrominated diphenyl ethers) contributed to renal lesions and are believed to reduce bone mineral density. Because OHCs are also hepatotoxic, we investigated liver histology of 32 subadult, 24 adult female, and 23 adult male East Greenland polar bears sampled during 1999-2002. Light microscopic changes consisted of nuclear displacement from the normal central cytoplasmic location in parenchymal cells, mononuclear cell infiltrations (mainly portally and as lipid granulomas), mild bile duct proliferation accompanied by fibrosis, and fat accumulation in hepatocytes and pluripotent Ito cells. Lipid accumulation in Ito cells and bile duct hyperplasia accompanied by portal fibrosis were correlated to age, whereas no changes were associated with either sex or season (summer vs. winter). For adult females, hepatocytic intracellular fat increased significantly with concentrations of the sum of hexachlorocyclohexanes, as was the case for lipid granulomas and hexachlorobenzene in adult males. Based on these relationships and the nature of the chronic inflammation, we suggest that these findings were caused by aging and long-term exposure to OHCs. Therefore, these changes may be used as biomarkers for OHC exposure in wildlife and humans. To our knowledge, this is the first time liver histology has been evaluated in relation to OHC concentrations in a mammalian wildlife species, and the information is important to future polar bear conservation strategies and health assessments of humans relying on OHC-contaminated food resources.