Lindane-induced generation of reactive oxygen species and depletion of glutathione do not result in necrosis in renal distal tubule cells

Insecticide use and risk of non-Hodgkin lymphoma subtypes: A subset meta-analysis of the North American Pooled Project

Insecticide use has been linked to increased risk of non-Hodgkin lymphoma (NHL), however, findings of epidemiologic studies have been inconsistent, particularly for NHL subtypes. We analyzed 1690 NHL cases and 5131 controls in the North American Pooled Project (NAPP) to investigate self-reported insecticide use and risk of NHL overall and by subtypes: follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and small lymphocytic lymphoma (SLL). Odds ratios (OR) and 95% confidence intervals for each insecticide were estimated using logistic regression. Subtype-specific associations were evaluated using ASSET (Association analysis for SubSETs). Increased risks of multiple NHL subtypes were observed for lindane (OR = 1.60, 1.20-2.10: FL, DLCBL, SLL), chlordane (OR = 1.59, 1.17-2.16: FL, SLL) and DDT (OR = 1.36, 1.06-1.73: DLBCL, SLL). Positive trends were observed, within the subsets with identified associations, for increasing categories of exposure duration for lindane (P_trend = 1.7 × 10^-4 ), chlordane (P_trend = 1.0 × 10^-3 ) and DDT (P_trend = 4.2 × 10^-3 ), however, the exposure-response relationship was nonlinear. Ever use of pyrethrum was associated with an increased risk of FL (OR = 3.65, 1.45-9.15), and the relationship with duration of use appeared monotonic (OR for >10 years: OR = 5.38, 1.75-16.53; P_trend = 3.6 × 10^-3 ). Our analysis identified several novel associations between insecticide use and specific NHL subtypes, suggesting possible etiologic heterogeneity in the context of pesticide exposure.

Human BJ Fibroblasts is an Alternative to Mouse BALB/c 3T3 Cells in In Vitro Neutral Red Uptake Assay

The OECD GD 129 BALB/c 3T3 neutral red uptake (NRU) assay is a standardized test method for estimating starting dose for an acute oral systemic toxicity test in rodents. Mouse BALB/c 3T3 fibroblasts are the most commonly used cells in the NRU assay. We have previously transferred and validated BALB/c 3T3 NRU assay in our GLP laboratory. Subsequently, in order to obtain more human-relevant cytotoxicity data, we performed an intralaboratory validation using human BJ fibroblasts in the NRU assay instead of mouse BALB/c 3T3 fibroblasts. Here, we present comparative cytotoxicity data of 26 different test chemicals (pharmaceuticals, industrial chemicals, pesticides and food additives) produced with both BALB/c 3T3 NRU and BJ NRU assays.

Non-hodgkin lymphoma risk and insecticide, fungicide and fumigant use in the agricultural health study

Farming and pesticide use have previously been linked to non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL) and multiple myeloma (MM). We evaluated agricultural use of specific insecticides, fungicides, and fumigants and risk of NHL and NHL-subtypes (including CLL and MM) in a U.S.-based prospective cohort of farmers and commercial pesticide applicators. A total of 523 cases occurred among 54,306 pesticide applicators from enrollment (1993-97) through December 31, 2011 in Iowa, and December 31, 2010 in North Carolina. Information on pesticide use, other agricultural exposures and other factors was obtained from questionnaires at enrollment and at follow-up approximately five years later (1999-2005). Information from questionnaires, monitoring, and the literature were used to create lifetime-days and intensity-weighted lifetime days of pesticide use, taking into account exposure-modifying factors. Poisson and polytomous models were used to calculate relative risks (RR) and 95% confidence intervals (CI) to evaluate associations between 26 pesticides and NHL and five NHL-subtypes, while adjusting for potential confounding factors. For total NHL, statistically significant positive exposure-response trends were seen with lindane and DDT. Terbufos was associated with total NHL in ever/never comparisons only. In subtype analyses, terbufos and DDT were associated with small cell lymphoma/chronic lymphocytic leukemia/marginal cell lymphoma, lindane and diazinon with follicular lymphoma, and permethrin with MM. However, tests of homogeneity did not show significant differences in exposure-response among NHL-subtypes for any pesticide. Because 26 pesticides were evaluated for their association with NHL and its subtypes, some chance finding could have occurred. Our results showed pesticides from different chemical and functional classes were associated with an excess risk of NHL and NHL subtypes, but not all members of any single class of pesticides were associated with an elevated risk of NHL or NHL subtypes. These findings are among the first to suggest links between DDT, lindane, permethrin, diazinon and terbufos with NHL subtypes.

Chlorobenzenes, lindane and dieldrin induce apoptotic alterations in human peripheral blood lymphocytes (in vitro study)

In this study, we have assessed apoptotic effect of 1,2,4-trichlorobenzene, hexachlorobenzene, lindane and dieldrin on human peripheral blood lymphocytes. We observed an increase in ROS formation and a decrease in mitochondrial transmembrane potential in the cells incubated with low concentrations of all compounds studied, in particular lindane and dieldrin. ROS formation and changes in mitochondrial transmembrane potential may have influenced caspase-3 activation, a crucial enzyme in the apoptotic process. Moreover, chlorobenzenes, and in particular lindane and dieldrin changed cells' membrane permeability and induced phosphatidylserine translocation, which confirmed that they are capable of inducing apoptosis in human lymphocytes. Apoptotic changes in human lymphocytes provoked by biologically relevant concentrations of these substances suggest that they may disturb function of immunological system especially among people occupationally exposed to their action.

Histone deacetylase inhibitor, sodium butyrate, attenuates gentamicin-induced nephrotoxicity by increasing prohibitin protein expression in rats

The major purpose in our study was to investigate the effects of sodium butyrate (NaBu) on nephrotoxicity induced by gentamicin in rats and determine further whether the protective effect is mediated by modulation of prohibitin protein expression. Gentamicin was injected intraperitoneally (100 mg/kg body weight) once daily for 8 days to induce nephrotoxicity. The effect of acute and chronic treatment of sodium butyrate on nephrotoxicity induced by gentamicin was assessed. Various doses of sodium butyrate (50, 100, 200 mg/kg, i.p.) was administered 30 min prior to the daily gentamicin injection. Histological analysis was used to evaluate the lesions in kidney after gentamicin administration. Expression of prohibitin was evaluated with immunohistochemical and western blot analysis. The present study demonstrated that gentamicin treatment for 8 consecutive days significantly increased in the levels of blood urea nitrogen, creatinine, kidney injury molecule (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) which indicated nephrotoxicity induced by gentamicin. In addition, chronic treatment with NaBu significantly attenuated gentamicin-induced nephrotoxicity by increasing activities of superoxide dismutase, catalase and reduced glutathione. Immunohistochemical studies in gentamicin-induced rats also demonstrated an increase in the levels of inducible prohibitin after treatment with sodium butyrate. Our results indicated that sodium butyrate, a histone deacetylase inhibitor, decreased gentamicin-induced nephrotoxicity by enhancing renal antioxidant enzymes activity and the expression of prohibitin protein.

Electroencephalogram, cognitive state, psychological disorders, clinical symptom, and oxidative stress in horticulture farmers exposed to organophosphate pesticides

The aim of this paper was to study the toxicity of organophosphate (OP) pesticides in exposed farmers for electroencephalography, cognitive state, psychological disorders, clinical symptom, oxidative stress, acetylcholinesterase, and DNA damage. A comparative cross-sectional analysis was carried out in 40 horticulture farmers who were exposed to OPs in comparison to a control group containing 40 healthy subjects with the same age and sex and education level. Lipid peroxidation (LPO), superoxide dismutase (SOD), catalase, glutathione peroxidase, DNA damage, total antioxidant capacity (TAC), total thiol molecules, and acetylcholinesterase (AChE) activity were measured in the blood of subjects. Clinical examination and complete blood test were undertaken in order to record any abnormal sign or symptoms. Cognitive function, psychological symptoms, and psychological distress were examined and recorded. Comparing with controls, the farmers showed higher blood levels of SOD and LPO while their TAC decreased. Farmers showed clinical symptoms such as eczema, breathing muscle weakness, nausea, and saliva secretion. Regarding cognitive function, the orientation, registration, attention and calculation, recall, and language were not significantly different in farmers and controls. Among examinations for psychological distress, only labeled somatization was significantly higher in farmers. The present findings indicate that oxidative stress and inhibition of AChE can be seen in chronically OP-exposed people but incidence of neuropsychological disorders seems a complex multivariate phenomenon that might be seen in long-term high-dose exposure situations. Use of supplementary antioxidants would be useful in the treatment of farmers.