Investigating aneuploidy-inducing effect of Nemacur, Rogor, and Dursban in human peripheral blood lymphocyte cultures

For many years, organophosphate (OP) pesticides have been considered an attractive choice for pest control around the world. Excessive use of OPs is a concerning issue for human health. Although the genotoxic effect of these pesticides has been reported, studies that examined their aneuploidy-inducing effect are limited or absent. Therefore, we sought to investigate the potential of OP pesticides, which are extensively used in the Gaza Strip, to induce aneuploidy in human peripheral blood lymphocyte (PBL) cultures. To achieve this goal, we first assessed the cytotoxic effect of selected concentrations of Nemacur (fenamiphos), Rogor (dimethoate), and Dursban (chlorpyrifos) on human PBL cultures by the MTT assay. Then, fluorescence in situ hybridization (FISH) technique was used to determine the frequency of induced aneuploidy (chromosome loss or gain) in human PBL cultures treated with different concentrations of the three types of OPs. We found that all the OPs treatments used did not show appreciable cytotoxic effects. Increase in frequencies of aneuploidy, chromosome loss, and chromosome gain were observed after each treatment as compared to the results of their respective solvent control cultures, and that increase of aneuploidy was significantly evident at 0.050 mg/ml of Nemacur. It was also noticed that chromosome loss is more frequent than chromosome gain for each concentration of the three types of OPs. While the aneuploidy induction effect of the investigated OPs is not significant (except for the 0.050 mg/ml of Nemacur), these pesticides should be examined further since many people are exposed to them.

Plasma cholinesterase activity is influenced by interactive effect between omethoate exposure and CYP2E1 polymorphisms

The aim of this study was to explore the association between metabolizing enzyme gene polymorphisms and the decrease in cholinesterase activity induced by omethoate exposure. A total of 180 workers exposed to omethoate over an extended period were recruited along with 115 healthy controls. Cholinesterase activity in whole blood, erythrocyte, and plasma was detected using acetylthiocholine and the dithio-bis-(nitrobenzoic acid) method. Six polymorphic loci of GSTT1(+/-), GSTM1(+/-), GSTP1 rs1695, CYP2E1 rs6413432, CYP2E1 rs3813867, and PON2 rs12026 were detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The gene-environment interactions were analyzed using the generalized linear model method. The cholinesterase activity of erythrocyte and plasma in the exposure group was significantly lower than that in the control group (P < 0.001) in general. The plasma cholinesterase activity in the TT + AT genotype in CYP2E1 rs6413432 was lower than that in the AA genotype in the exposure group (P = 0.016). Interaction between the AA genotype in CYP2E1 rs6413432 and omethoate exposure had a significant effect on plasma cholinesterase activity (P = 0.079). The decrease in plasma cholinesterase activity was associated with interaction between the AA genotypes in rs6413432 and omethoate exposure.

Transcriptomic responses of the clam Meretrix meretrix to the organophosphorus pesticide (dimethoate)

Organophosphorus pesticides (OPs) play a certain role in promoting the development of agriculture and forestry, but they may cause potential harm to aquatic life when entering rivers and polluting water sources. Previous researches have shown that OPs participate in the regulation mechanism of aquatic organisms. Here, our aim is to determine the underlying mechanisms of one OP (dimethoate) at the transcriptional level using the clam Meretrix meretrix. 4119 DEGs were obtained from high-throughput RNA sequencing data. Then, expression profiles of some genes were verified by qPCR, which showed a positive correlation with the RNA sequencing results. 14,481 simple sequence repeats were also identified and could be further used as molecular markers. In addition, some oxidative, immune, and stress-related genes were further discussed and could also be used as biomarkers to indicate the biological response of dimethoate. This study will help to better understand the clam's response mechanism to dimethoate stress.

Transcriptional and physiological effects of the pyrethroid deltamethrin and the organophosphate dimethoate in the brain of honey bees (Apis mellifera)

The pyrethroid deltamethrin and the organophosphate insecticide dimethoate are widely used in agriculture and in urban areas. Both plant protection products (PPPs) unintendedly result in adverse effects in pollinators. Currently, the sublethal effects of both compounds are poorly known, particularly on the molecular and biochemical level. Here we analysed effects of deltamethrin and dimethoate at environmental and sublethal concentrations in honey bee workers by focusing on transcriptional changes of target genes in the brain. In addition, expression of vitellogenin protein and activity of acetylcholinesterase were assessed upon dimethoate exposure to assess physiological effects. Deltamethrin resulted in induction of the cyp9q2 transcript at 0.53 ng/bee, while dimethoate led to induction of vitellogenin on the mRNA and protein level at 2 ng/bee. Transcripts of additional cytochrome P450-dependent monooxygenases (cyps) and genes related to immune system regulation were not differentially expressed upon PPP exposure. Dimethoate but not deltamethrin led to a strong and concentration-related inhibition of the acetylcholinesterase at 2 and 20 ng/bee. Our data demonstrate that deltamethrin and dimethoate exhibit transcriptional effects at environmental concentrations in the brain of honey bees. Dimethoate also strongly affected physiological traits, which may translate to adverse effects in forager bees.

Relationship between alcohol co-ingestion and outcome in profenofos self-poisoning - A prospective case series

INTRODUCTION

The importance of alcohol co-ingestion for outcome in organophosphorus (OP) insecticide self-poisoning has only been studied for the relatively hydrophilic dimethyl insecticide, dimethoate. We aimed to assess the effect of alcohol in acute poisoning with the lipophilic S-alkyl OP insecticide, profenofos.

METHODOLOGY

Demographic and clinical data, including an alcohol history, were prospectively collected from all cases of acute poisoning with agricultural profenofos EC50 presenting to two Sri Lankan hospitals over seven years.

RESULTS

Of 1859 patients with acute OP insecticide self-poisoning, 243 (13.1%) reported ingestion of profenofos (male 182/243, 74.9%). Alcohol co-ingestion was reported by 64/243 (26.3%). All patients reporting alcohol co-ingestion were male (64/64 [100%] vs 118/179 [65.9%] not reporting alcohol ingestion, p<0.001). More patients reporting alcohol co-ingestion died (10/64 [15.6%] vs 10/179 [5.6%]; p = 0.013) and required intubation (13/64 [20.3%] vs 16/179 [8.9%], p = 0.016) compared to those who did not co-ingest alcohol. Using multi-logistic regression, controlling for the estimated dose ingested, age (OR 11.1 [2.5 to 48.9] for age > 35 years vs ≤35 years) and alcohol co-ingestion (OR 3.1 [1.2 to 7.9]) were independently associated with increased risk of death. Increased risk of intubation was independently associated with age (OR 3.2 [1.6 to 6.6] for age > 35 years vs ≤35 years) and alcohol co-ingestion (OR 3.2 [1.6 to 6.4]).

CONCLUSION

A history of alcohol co-ingestion, as well as older age, is independently associated with worse outcome in patients' self-poisoned with profenofos.

Dimethoate induces kidney dysfunction, disrupts membrane-bound ATPases and confers cytotoxicity through DNA damage. Protective effects of vitamin E and selenium

Dimethoate (DM) is an organophosphate insecticide widely used in agriculture and industry and has toxic effects on non-target organisms especially mammalian. However, we still know little about DM-induced kidney injury and its alleviation by natural antioxidants. In the present study, selenium (Se), vitamin E, DM, Se+DM, vitamin E+DM, Se+vitamin E+DM were given to adult rats for 4 weeks. Plasma creatinine and uric acid, kidney MDA, PC, H2O2 and AOPP levels were higher, while Na(+)-K(+)-ATPase and LDH values were lower in the DM group than those of controls. A smear without ladder formation on agarose gel was shown in the DM group, indicating random DNA degradation and DM-induced genotoxicity. A decrease in kidney GSH, NPSH and plasma urea levels and an increase in GPx, SOD and catalase activities were observed in the DM group when compared to those of controls. Plasma cystatin C levels increased, indicating a decrease in glomerular filtration rate. When Se or vitamin E was added through diet, the biochemical parameters cited above were partially restored in Se+DM and vitamin E+DM than DM group. The joint effect of Se and vitamin E was more powerful against DM-induced oxidative stress and kidney dysfunction. The changes in biochemical parameters were substantiated by histological data. In conclusion, our results indicated a possible mechanism of DM-induced nephrotoxicity, where renal genotoxicity was noted, membrane-bound ATPases and plasma biomarkers were disturbed. Se and vitamin E ameliorated the toxic effects of this pesticide in renal tissue suggesting their role as potential antioxidants.

Dimethoate induced oxidative damage and histopathological changes in lung of adult rats: modulatory effects of selenium and/or vitamin E

OBJECTIVE

To determine the efficiency of selenium and/or vitamin E to alleviate lung oxidative damage induced by dimethoate, an organophosphorus compound.

METHODS

Adult Wistar rats were exposed during 30 days either to dimethoate (0.2 g/L of drinking water), dimethoate+selenium (0.5 mg/kg of diet), dimethoate+vitamin E (100 mg/kg of diet), or dimethoate+selenium+vitamin E.

RESULTS

Exposure to dimethoate caused oxidative stress in lung evidenced by an increase of malondialdehyde, protein carbonyl groups and advanced oxidation protein products. An increase in glutathione peroxidase, superoxide dismutase, catalase and a decrease in acetylcholinesterase and butyrylcholinesterase activities, glutathione, non-protein thiols and vitamins C levels were observed. Histopathological changes in lung tissue were noted as emphysema, hemorrhages and hemosiderin deposits. Co-administration of selenium or vitamin E to the diet of dimethoate treated rats ameliorated the biochemical parameters as well as histological impairments. The joint effect of these elements was more powerful in antagonizing dimethoate-induced lung oxidative damage.

CONCLUSION

We concluded that selenium and vitamin E ameliorated the toxic effects of this pesticide in lung tissue suggesting their role as potential antioxidants.

Final Results of a Phase II Trial of Preoperative TAC (Docetaxel/Doxorubicin/Cyclophosphamide) in Stage III Breast Cancer

BACKGROUND

The use of preoperative chemotherapy for breast cancer has been demonstrated to result in similar disease-free survival (DFS) and overall survival (OS) as postoperative adjuvant chemotherapy. Additionally, the rate of pathologic complete response (pCR) in the breast after preoperative chemotherapy has been shown to correlate with survival. The objective of this study was to determine the pCR rate in patients with stage III breast cancer treated with 4 cycles of TAC (docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2) on day 1 before surgery.

PATIENTS AND METHODS

From November 1998 through August 2001, we treated 40 patients (mean age, 47 years) with stage III breast cancer with TAC administered every 3 weeks for 4 cycles.

RESULTS

We now report follow-up at 24 months. Responses were seen in 83% of patients, with 25% experiencing a clinical complete response, of which 4 patients (10%) had pCRs. At a follow-up of 2 years, data on DFS and OS are available on 37 patients: 12 patients (38%) had disease progression, and 7 patients (21%) had died. Despite the use of prophylactic ciprofloxacin, some degree of myelosuppression was seen in all patients, with 24 patients (63%) experiencing grade 3/4 neutropenia.

CONCLUSION

Based on the pCR rate seen in this trial, docetaxel given concomitantly with AC (doxorubicin/cyclophosphamide) for 4 cycles does not appear to be superior to 4 cycles of AC as preoperative treatment for stage III breast cancer. Based on other trials, longer durations of therapy and/or sequencing of AC and docetaxel may result in a higher pCR rate.

Evaluation of dimethoate-induced implantation delay and nidation by progesterone in albino mice

We investigated the effect of dimethoate, an organophosphorus insecticide, and progesterone on implantation. Virgin pregnant albino mice received dimethoate orally at a dose of 28 mg/kg body wt/d from days 1 to 7. Laparotomy on day 8 showed no implantation sites. Thereafter, graded doses of progesterone, 4, 9, and 12 mg/kg body wt/d, were administered up to day 15. A group of control mice received a similar quantity of distilled water. Autopsy on day 8 revealed that the control mice were pregnant, with a normal number of implantations and 8.08% pre-implantation loss, whereas treatment with dimethoate for 7 days or with dimethoate for 7 days followed by progesterone for 8 days totally abolished implantation, with a 100% pre-implantation loss. In all treated mice, a significant decrease occurred in body weight gain, as well as in the weight of the ovaries, uterus, and liver when compared with those of control mice. No significant changes were found in other organ weights (kidneys, adrenals, spleen, thymus, or thyroid). The observed effect of dimethoate could be due to an imbalance in the estrogen-progesterone ratio essential for implantation. Alternatively, dimethoate treatment could result in blastotoxicity or have an impact on the hypothalamic-pituitary axis.

The garden snail (Helix aspersa) as a bioindicator of organophosphorus exposure: effects of dimethoate on survival, growth, and acetylcholinesterase activity

The garden snail (Helix aspersa) is currently used as bioindicator of metallic pollution. Our objective was to extend its use to organic chemicals by studying the effects and tissue concentrations of the organophosphorus pesticide dimethoate following dietary uptake. After exposure for four weeks to increasing doses of pesticide in the diet, the median lethal concentration (LC50) was determined to be 3,700 microg/g food. Clinical signs indicated a no-observed-effect concentration of 100 microg/g and a lowest-observed-effect concentration of 250 microg/g. The growth parameters were decreased with increasing exposure to the pesticide. The median effective concentration (EC50), which was evaluated based on both shell diameter and dry weight inhibitions, was 665 and 424 microg/g, respectively, and the EC10 was 180 and 145 microg/g, respectively. Accumulation in the viscera was related to the amount of dimethoate in the food. The bioconcentration factors were low (>6 x 10(-3)). Acetylcholinesterase (AChE) activity was strongly decreased (80% from 250 microg/g). In conclusion, we demonstrated that the species H. aspersa could be a useful sentinel organism for organophosphorus contamination surveys. Among the effects measured, the inhibition of AChE activities and clinical signs were the most sensitive, followed by the growth parameters. These results confirm the suitability of the garden snail for development of sublethal toxicity tests using primary consumers and aboveground organisms.

[Sanitary characteristics of working conditions in vegetable growing places in the Republic of Tatarstan]

The paper gives a sanitary characterization of working conditions in closed soil vegetable growing, a branch of agriculture. These conditions are one of the factors predisposing to occupational disease in agricultural workers. Studies in this area may evaluate the risk of occupational diseases.

The effect of dimethoate and cypermethrin on soil-dwelling beetles under semi-field conditions

The effect of cypermethrin and dimethoate exposure on soil-dwelling beetles, in spring barley at different growth stages, of doses of up to eight times maximum field application rate has been investigated. Doses up to eight times maximum field application rate of cypermethrin did not have any acute effects on larger beetles, such as P. melanarius and C. erratus. Small beetles (A. bilineata, A. dorsale, B. lanpros, B. obtusum) were not harmed by doses up to two times maximum field application rate. T. hypnorum was affected at maximum field rate. Dimethoate at maximum field application rate harmed all species, but in particular the smaller species. When dimethoate was applied in high foliage density fields in the summer, very severe acute effects on spring breeding beetles were found. In the autumn, when only a low crop cover existed, this very high effect was not observed. The severe effect in the summer may be explained by the mode of action of dimethoate on 'old beetles'. The observed high toxic effect of dimethoate on spring breeders in the summer is expected only to have limited effect on the population, because the spring breeders at this time of the year have finished their egg depositing in the soil.

Effect of exposure to organophosphate pesticides on serum cholinesterase levels

In this paper are reported the effects of organophosphate pesticide exposure. Agricultural workers were compared with an age- and sex-matched control group selected from the general population. A significant difference was detected (Student's t = 1.99, p = .05) between the median activity levels of serum cholinesterase in agricultural workers at the end of the work day (mean 4.44, 95% CI = 4.12-4.77), compared with those in the control group (mean = 4.85, 95% CI = 4.57-5.13). The decrease in cholinesterase activity, measured at the beginning (mean = 4.70, 95% CI = 4.38-5.02) and end of the work day, was very significant (paired t = 2.70, p = .01). An interaction was identified between the type of work and the worker's age. Younger workers tended to perform more dangerous activities, and they experienced a greater decrease in cholinesterase activity. This study indicates that subclinical intoxication of agricultural workers, by pesticides, is occurring in Mexico and indicates the need for primary prevention programs that address occupational contact with such substances.

Acute pancreatitis after cutaneous exposure to an organophosphate insecticide

Pancreatitis secondary to organophosphate insecticide toxicity is extremely rare. The few previously reported cases have resulted from oral ingestion of these agents. We present the first reported case of acute pancreatitis occurring after cutaneous exposure to an organophosphate insecticide. Symptoms of pancreatitis persisted for 6 months, followed by total resolution. The proposed mechanisms of pancreatic injury caused by organophosphate compounds are discussed.

Herbicides and congenital malformations: a review for the paediatrician

The herbicides 2, 4, 5-T and 2, 4-D are relatively non-toxic to primates, in acute exposure. Dioxins, which have occurred as impurities in these two herbicides, manifest universal biological toxicity. The best understood dioxin TCDD, has, in susceptible strains of mice, a very low teratogenic minimal effective dose of 1-10 micrograms/kg. This fact has engendered an era of uncertainty about the potential teratogenic effects of herbicides, in the context of potential human exposure. This paper reviews current knowledge concerning herbicide teratogenesis following maternal exposure. Because of species specificity of teratogenic agents, it is not possible to extrapolate from effects in lower animals to potential effects in humans. It remains a fact however that all proven human teratogens have parallel animal models. Following maternal exposure to herbicides and to dioxins, it has not been possible to produce teratogenic effects in primates, although fertility may be affected. Epidemiological reports from Hungary, Italy (the ICMESA accident), New Zealand, the United States, Europe and Australia have not revealed any positive evidence to indicate that a human herbicide teratogenic syndrome exists.

Occupational exposure to organophosphorus insecticides and synthetic pyrethroid

Dermal and respiratory exposure to pirimiphosmethyl, dimethoate and permethrin were determined for applicators and operators in greenhouse tomato spraying operations. Dermal exposure is several times higher than the degree of respiratory exposure. Dermal exposure in terms of different parts of the body shows significant differences. For applicators the exposure of hands, arms and legs is the greatest, and the operators are the most exposed on their hands and to a small extent on legs. This fact should be taken into account when providing the workers with suitable protective clothing. The carefully selected technology of spraying also has great significance in decreasing the degree of exposure. Because of the chronic toxicity of dimethoate, all possible methods should be taken to reduce exposure.