Malathion exposure may increase infertility risk among US Adults: Results from the 2015-2016 NHANES.

BACKGROUND AND PURPOSE: Organophosphate pesticides such as malathion are the most widely used pesticides. Despite endocrine-disrupting effects, there is a paucity of information regarding chronic exposure to non-persistent organopesticides such as malathion. The purpose of this study is to describe the exposure burden among U.S. residents as well as possible impacts on fertility. METHODS: Population-based data collected by the National Health and Nutrition Examination Survey (NHANES) between 2015 and 2016 were used to perform a retrospective analysis on urinary concentrations of malathion diacid. Samples were assessed from 1703 adult participants, statistically weighted to represent over 231 million individuals. General linear models were used to examine associations between exposure and reproductive health measures among pre-menopausal women. RESULTS: Detectable concentrations of malathion diacid were identified in 16.1 % (n = 254) of samples. Concentrations were higher among women who reported seeing a physician due to difficulties becoming pregnant (P < 0.001; r2 = 0.12) as well as among women who reported trying for at least a year to become pregnant (P < 0.001; r2 = 0.06). CONCLUSIONS: Exposure to malathion is associated with a history of reproductive health challenges among women.

Pre-conceptional and prenatal exposure to pesticides and pediatric neuroblastoma. A meta-analysis of nine studies.

Neuroblastoma is primarily an embryonal tumor of infancy. Recently, some toxicological agents used as pesticides have been associated with an increased incidence of this tumor. We intended to determine the potential association between prenatal exposure to pesticides and the incidence of neuroblastoma in children. Studies targeting the link between neuroblastoma and pesticides were searched in PUBMED, SCOPUS, and Google Scholar from January 1, 1960, through December 2020. We performed a PRISMA-based systematic review and meta-analysis. In addition, we took into consideration the IARC evaluation on pesticides issued in recent monographs. Prenatal pesticide exposure is associated with an increased risk of neuroblastoma with an OR of 1.6 (1.1-2.3; p = 0.013), while the OR is 1.0 (0.8-1.3; p = 0.723) for pesticide exposure after birth. There is a significant association between prenatal pesticide exposure and neuroblastoma. We emphasize the IARC conclusions evaluating the carcinogenicity of diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.

Effects of Some Insecticides (Deltamethrin and Malathion) and Lemongrass Oil on Fruit Fly (Drosophila melanogaster).

<b>Background and Objective:</b> The continuous use of pesticides in the ecosystem is of great concern, as some of them are highly stable and impact non-target organisms. The effect was tested of different concentrations of insecticides such as (Deltamethrin and Malathion) and natural products, Including, lemongrass oil on Fruit Fly (<i>Drosophila melanogaster</i>), to calculate the concentration at which the highest mortality occurred and death half the number of individuals after 96 hrs, as well as calculating the half-lethal time for individuals. <b>Materials and Methods:</b> This study, which evaluated the toxicity of five different concentrations (0.75, 1.00, 1.25, 1.50 and 1.75 mg L¹) of Malathion, (0.05, 0.10, 0.21, 0.53 and 1.48 mg L¹) of Deltamethrin and lemongrass oil (0.25, 0.50, 0.75, 1.00 and 1.50 mg L¹) on the insect of <i>Drosophila melanogaster</i> after 96 hrs of treatment. <b>Results:</b> From the results of this study, the concentration (LC₅₀= 2.938 mg L¹) of Malathion leads to kills half of the individuals, compared to Deltamethrin a higher concentration (LC₅₀= 4.8673 mg L¹) that leads to killing half of the individuals. While lemongrass oil the concentration (LC₅₀= 9.7478 mg L¹) leads to kills half of individuals. Also, when used Deltamethrin it takes (LT₅₀= 660.277) hours to kill half of the individuals compared to Malathion, which takes approximately (LT₅₀ = 321.862) hours to death half of the individuals. But lemongrass oil (LT₅₀= 819.745) hours to kill half of the individuals. <b>Conclusion:</b> In conclusion, the lemon plant and its components have excellent potential for being used in the control of <i>Drosophila melanogaster</i>, which had an effective role in biological control.

Protective effect of thymoquinone against lung intoxication induced by malathion inhalation.

Malathion is considered one of the vastest pesticides use all over the world. Malathion-inhalation toxicity commonly occurred in many occupational farmers. Therefore, this study aimed to ameliorate the possible malathion-induced pulmonary toxicity through thymoquinone administration. Forty animals were used to conduct our study, divided into five groups; G1 control group, G2 thymoquinone (50 mg/kg) group, G3 malathion group (animals inhaled 100 mg/ml/m3 for 15 min for 5 days/week for three weeks), G4 and G5 were subjected to the same malathion inhalation protocol beside oral thymoquinone administration at doses of 25 and 50 (mg/kg), respectively. Malathion-inhalation induced marked systemic toxicity as hepatotoxicity and nephrotoxicity associated with increased serum hepatic and renal enzymes, and hypersensitivity accompanied with increased total IgE serum level. The lung showed severe interstitial pneumonia associated with severe vascular damage and marked eosinophil infiltration. Moreover, the lung showed a marked decrease in the pulmonary surfactant protein, especially SP-D gene expression. While, thymoquinone treatment to malathion-inhaled animals decremented the following; hepatic enzymes and renal function tests, total IgE as well as pneumonia and hypersensitivity pathological features, and augmented the expression of SP-D. In conclusion, thymoquinone could be potentially used in pest control workers to ameliorate the systemic and pulmonary intoxication caused by one of the most field-used pesticides.

Short-time Effects of Malathion Pesticide on Functional and Histological Changes of Liver and Kidney in Female Mice.

BACKGROUND AND OBJECTIVE: The malathion is one of the most important organophosphorus pesticides used in Iraq. The present study was designed to investigate the short-time effects of the malathion on the biochemical parameters of AST, ALT, ALP, urea, creatinine, total cholesterol, triglycerides and total protein as well as histological changes of the liver and kidneys of female laboratory mice for an interval of 6 days. MATERIALS AND METHODS: The animals were divided into 3 groups, each group included 8 mice. They were injected with the pesticide in the intraperitoneal region. The 1st group (the control group) was injected with 0.1 mL of distilled water, the 2nd group (the low dose group) was injected with 0.1 mL of the pesticide solution at 3 mg/body weight while the 3rd group (the high dose group) was injected with 0.1 mL of the pesticide solution at a concentration of 6 mg/body weight. RESULTS: The biochemical tests of the liver and kidney showed significant elevation in serum AST, urea, creatinine and cholesterol concentrations in mice compared to control group (p<0.05). In addition, the results showed a significant decrease in the ALP, triglycerides and the total protein in serum of the treated mice. Also, the results of histological sections of the liver and kidneys included congestion, necrosis, degeneration of cytoplasm, blood congestion, apoptosis, bleeding and sloughing of epithelial cells to the renal tubular lumen. CONCLUSION: Finally, the results indicated that malathion pesticide has the ability to induce hepatic and renal toxicity in mice within 6 days.

Effect of life stage and pesticide exposure on the gut microbiota of Aedes albopictus and Culex pipiens L.

Pesticides commonly contaminate the aquatic environments inhabited by mosquito juveniles. However, their role in shaping the mosquito microbiota is not well understood. We hypothesized that environmentally relevant concentrations of atrazine, permethrin and malathion will mediate a shift in the mosquito gut bacterial community structure due to their toxic effect on the aquatic bacterial communities, and reduce mosquito gut bacterial diversity by enriching pesticide-degrading bacterial communities over susceptible taxa. Illumina MiSeq sequencing of the V3-V4 hypervariable regions of the 16 S rRNA gene was used to characterize the microbial communities of larval and adult stages of the two mosquito species and the water samples from microcosms treated with each of the pesticides, separately. Bacterial community composition differed by sample type (larval stage vs. adult stage) and water sampling date (day 3 vs. day 7), but not by pesticide treatment. In larval stages, bacterial OTU richness was highest in samples exposed to malathion, intermediate in permethrin, and lowest in controls. Bacterial richness was significantly higher in larval stages compared to adult stages for all treatments. This study provides a primer for future studies evaluating mosquito microbial responses to exposures to chemical pesticides and the possible implications for mosquito ecology.

Walnut Polyphenol Extract Protects against Malathion- and Chlorpyrifos-Induced Immunotoxicity by Modulating TLRx-NOX-ROS.

Malathion (MT) and chlorpyrifos (CPF) are immunotoxic organophosphate pesticides that are used extensively in agriculture worldwide. Dietary polyphenols protect against a variety of toxins. In this study, walnut polyphenol extract (WPE) prevents MT- or CPF-induced toxicity to splenic lymphocytes in vitro. WPE promotes the proliferation of MT-exposed splenocytes, as indicated by increases in the proportions of splenic T-lymphocyte subpopulations (CD3+, CD4+, and CD8+ T cells) and levels of T-cell-related cytokines interleukin (IL)-2, interferon-γ, IL-4, and granzyme B, and decreases the apoptosis-associated proteins Bax and p53. WPE also significantly enhances the proliferation of CPF-exposed splenic B lymphocytes (CD19+ B cells) and levels of the B-cell-related cytokine IL-6, leading to decreases of the apoptosis-associated proteins Bax and p53. These effects are related to reduced production of reactive oxygen species (ROS), as evidenced by normalized hydroxyl radical (•OH), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione (GSH) levels, which are associated with decreased expression of NADPH oxidase 2 (NOX2) and dual oxidase 1 (DUOX1). WPE inhibits the production of ROS and expression of NOX by regulating toll-like receptors 4 and 7 in MT- and CPF-exposed splenic lymphocytes. In conclusion, WPE protects against MT- or CPF-mediated immunotoxicity and inhibits oxidative damage by modulating toll-like receptor (TLR)x-NOX-ROS.

Transposable elements contribute to the genomic response to insecticides in Drosophila melanogaster.

Most of the genotype-phenotype analyses to date have largely centred attention on single nucleotide polymorphisms. However, transposable element (TE) insertions have arisen as a plausible addition to the study of the genotypic-phenotypic link because of to their role in genome function and evolution. In this work, we investigate the contribution of TE insertions to the regulation of gene expression in response to insecticides. We exposed four Drosophila melanogaster strains to malathion, a commonly used organophosphate insecticide. By combining information from different approaches, including RNA-seq and ATAC-seq, we found that TEs can contribute to the regulation of gene expression under insecticide exposure by rewiring cis-regulatory networks. This article is part of a discussion meeting issue 'Crossroads between transposons and gene regulation'.

Hepatoprotective effect of Aloe vera against cartap- and malathion-induced toxicity in Wistar rats.

Exposure to mixture of pesticides in agricultural practices pose a serious threat to the nontarget animals. In present work, we have evaluated the synergistic effect of cartap and malathion on rat liver followed by impact of Aloe vera leaves aqueous extract, which is not known. The animals in eight groups were used; each containing six rats: Group 1 acted as a control, Group 2-control with A. vera leaves aqueous extract, Group 3-with cartap, Group 4-with malathion, Group 5-with mixture of cartap and malathion, Group 6-cartap with the pretreatment of A. vera leaf extract, Group 7-malathion with the pretreatment of A. vera leaf extract, Group 8-mixture of cartap and malathion with the pretreatment of A. vera leaf extract . The animals treated for 15 days were killed after 24hr of last treatment. The biochemical studies in the rat liver demonstrated significant perturbations in the levels of nonenzymatic (glutathione and malondialdehyde) and enzymatic (superoxide dismutase, catalase, and glutathione- S-transferase) antioxidative indices. The histopathological examination of liver revealed serious congestion in central vein and the disorganization of hepatic cords due to pesticide treatment. The administration of A. vera leaves aqueous extract was able to markedly protect rat liver from the pesticides-induced toxicity. The data indicated that pesticides were able to significantly induce oxidative stress which was substantially reduced by the application of plant extract .

Pesticides as risk factors for head and neck cancer: A review.

Humans may be exposed to pesticides such as fungicides, herbicides, and insecticides, during occupational and non-occupational activities. Pesticides could be related to cancer development mainly because of their effects on the endocrine and immune systems and their cumulative effect. The present review evaluated in current literature evidence of an association between exposure to pesticides and the occurrence of head and neck cancer (HNC). A literature search for cohort studies was conducted in the PubMed, Web of science, and Cochrane databases. Methodological quality of each study was rated with the Scottish Intercollegiate Guidelines Network (SIGN) checklist. One thousand one hundred and thirty-two studies were identified. Thirty-two were included. Most of the studies found addressed occupational exposure to pesticides and were conducted in Europe and North America. Eleven high-quality studies were found. Most of them found no association between exposure to pesticides and increased risk of HNC. Two studies found some evidence of a positive association between pesticide (malathion and atrazine) exposure and thyroid cancer. The literature review does not support a clear evidence for association between pesticides exposure and HNC. Only limited evidence points to a positive association between exposure to some pesticides and thyroid cancer. Further standardized studies based on appropriate designs are required to clarify the effect of pesticides on the genesis of HNC, considering dose, length of exposure, and type of pesticide.

Cluster analysis profiling of behaviors in zebrafish larvae treated with antidepressants and pesticides.

Antidepressants are used by a substantial number of women in their childbearing years. Treatment may continue during pregnancy, since untreated depression poses a risk to the mother and child. However, many antidepressants readily pass through the placental barrier to reach the fetus or may be ingested by the newborn via breastmilk. Little is known about the effects of antidepressants on brain development and subsequent behavior in young children. In the current study, we used zebrafish as a model system to examine the neurodevelopmental effects of three commonly prescribed antidepressants, sertraline, duloxetine and bupropion. Zebrafish were exposed to these antidepressants during development and were examined for changes in larval avoidance behavior, activity, social behaviors, and anxiety-related behaviors. The results show that antidepressants commonly affect larval swim speeds and resting, and differentially affect other behaviors depending upon the exposure period. Using cluster analysis profiling, we compared the obtained results to previous reports on behavioral defects induced by organophosphate pesticides. We found that the behavioral profiles induced by antidepressants and pesticides overlap, indicating a common mechanism of action. We conclude that developmental antidepressant exposures lead to specific behavioral changes in zebrafish larvae. At present, it is not known if antidepressants have similar effects in human development.

[CHANGES IN THE FUNCTION OF LYMPHOCYTES AND CYTOKINE CONCENTRATION IN BLOOD CAUSED BY THE ACTION OF ATROPINE UNDER CONDITIONS OF ACUTE MALATHION INTOXICATION].

It was established in experiments on noninbred albino rats that acute intoxication with malathion (0.75 LD50) reduced the function of Th1 cells more significantly than the function of Th2 lymphocyte, decreases the activity of B cells and NK cells, blood levels of TNFa, IL-1b and IL-6, IFN-g, IL-2, and IL-4, while not significantly affecting the concentration of IL-10 and IL-13. Atropine (10 mg/kg) under conditions of acute malathion intoxication improved the function of T cells and B lymphocytes, NK cells, as well as the synthesis of immunoregulatory cytokines IFN-g, IL-2, and IL-4. At the same time, atropine in malathion intoxicated rats had no effect on suppression of the synthesis of proinflammatory cytokines TNF, IL-1g and IL-6 as well as the content of anti-inflammatory cytokines IL-10 and IL-13.

Hepato- and nephrotoxicity in male albino rats exposed to malathion and spinosad in stored wheat grains.

Adult male albino rats were fed on stored wheat grains (Triticum aestivum L.) treated with malathion and spinosad at both 8 and 16 ppm for 90 consecutive days to evaluate their hepatic and renal toxicity. The activity of serum acetylcholinesterase (AChE) was decreased in rats treated with the higher concentration of both tested pesticides. Biochemical parameters of liver functions [i.e., aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), acid phosphatase (ACP) activity, as well as total protein, albumin, bilirubin and cholesterol levels] were severely affected especially at higher concentration. Malathion and spinosad elevated the activity of ALT, AST, ALP and ACP in rats treated with the higher concentration. Also, total and direct bilirubin levels increased in rats treated with the higher concentration of both pesticides. On the contrary, both pesticides decreased total protein and albumin levels in treated rats in a concentration-dependent manner. Furthermore, malathion was found to be hyperglycemic. Kidney function parameters (i.e., urea and creatinine levels) were increased in treated rats in a concentration-dependent manner. The above mentioned effects were supported by histopathological examination of liver and kidney tissues. The obtained results indicated also that malathion was able to cause a more pronounced hepato- and renal toxicity in rats than spinosad.

The effects of the amphibian chytrid fungus, insecticide exposure, and temperature on larval anuran development and survival.

Chytridiomycosis, a disease caused by Batrachochytrium dendrobatidis (Bd), has been implicated as a cause of amphibian declines. Susceptibility may be influenced by environmental factors that suppress the immune response. The authors conducted a laboratory study to examine the effect of temperature, insecticide exposure, and Bd exposure during larval anuran development. The authors examined the consequences of exposure to Bd, an insecticide (carbaryl or malathion), and static or fluctuating temperature (15 °C, 20 °C, 25 °C, or 15 °C to 25 °C 72-h flux) on larval development through metamorphosis of the Pacific treefrog (Pseudacris regilla). High and fluctuating temperature had negative effects on survival in the presence of Bd. Insecticides inhibited the effects of Bd; time to tail resorption of Pacific treefrogs decreased when tadpoles were exposed to carbaryl. The present study indicates that abiotic factors may play a role in the host-pathogen interactions in this system.

Effects of amphibian chytrid fungus exposure on American toads in the presence of an insecticide.

Abiotic factors such as pesticides may alter the impact of a pathogen on hosts, which could have implications for host-pathogen interactions and may explain variation in disease outbreaks in nature. In the present laboratory experiment, American toad (Anaxyrus americanus) metamorphs were exposed to the amphibian chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd) and environmentally relevant concentrations of the insecticide malathion to determine whether malathion altered the effects of Bd exposure on growth and survival of toad metamorphs. Exposure to Bd significantly decreased survival over the 51 d of the experiment, suggesting that Bd could reduce recruitment into the terrestrial life stage when exposure occurs at metamorphosis. Malathion did not impact survival, but a 12-h exposure at metamorphosis significantly reduced terrestrial growth. Toads that were exposed to both Bd and malathion showed a nonsignificant trend toward the smallest growth compared with other treatments. The present study suggests that Bd may pose a threat to American toads even though population declines have not been observed for this species; in addition, the presence of both the insecticide malathion and Bd could reduce terrestrial growth, which could have implications for lifetime fitness and suggests that environmental factors could play a role in pathogen impacts in nature.

Lice.

Pediculosis (capitis, corporis, and pubis) share well-known features: worldwide prevalence (involving millions of people annually); parasites inducing skin lesions directly, and indirectly as a result of itching and hypersensitivity to parasites; and treatment based on good entomological knowledge of the parasite and practical considerations (ie, most available treatments do not act on eggs and should be repeated, depending on the life cycle of the parasites). Infestations are spread most commonly by close contacts. Social stigma and persistent misconceptions complicate the implementation of appropriate management strategies. Head and pubic lice infestations are diagnosed by the visualization of insects or viable nits (eggs). Primary treatments are topical pediculicides (permethrin or malathion), used twice, but emergence of resistance against pediculicides has created the need of alternative treatments including topical or oral ivermectin. Pubic lice are treated the same as head lice, but this finding should prompt evaluation for other sexually transmitted diseases. Body lice infestation should be suspected when symptoms of generalized itching occur in persons who do not change or wash their clothing or bedding regularly; lice may be found in the seams of their clothing.Topically administered permethrin may help to eradicate body lice, but personal hygiene measures are essential for successful treatment. Environmental treatment is also necessary for the eradication of the infestation. Health care personnel who come into contact with this population need to be well informed of the facts in order to disseminate accurate information for diagnosis and management.

Fresh frozen plasma as a successful antidotal supplement in acute organophosphate poisoning.

Despite improvements to intensive care management and specific pharmacological treatments (atropine, oxime, diazepam), the mortality associated with organophosphate (OP) poisoning has not substantially decreased. The objective of this examination was to describe the role of fresh frozen plasma (FFP) in acute OP poisoning. After a deliberate ingestion of malathion, a 55-year-old male suffering from miosis, somnolence, bradycardia, muscular fasciculations, rales on auscultation, respiratory insufficiency, as well as from an inhibition of red blood cell acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE), was admitted to hospital. Malathion was confirmed in a concentration of 18.01 mg L(-1). Apart from supportive measures (including mechanical ventilation for four days), antidotal treatment with atropine, oxime-pralidoxime methylsulphate (Contrathion(R)), and diazepam was administered, along with FFP. The potentially beneficial effects of FFP therapy included a prompt increase of BuChE activity (from 926 IU L(-1) to 3277 IU L(-1); reference range from 7000 IU L(-1) to 19000 IU L(-1)) and a reduction in the malathion concentration, followed by clinical recovery. Due to BuChE replacement, albumin content, and volume restitution, FFP treatment may be used as an alternative approach in patients with acute OP poisoning, especially when oximes are not available.

Relation of breast cancer and malathion aerial spraying in Arica, Chile / Relación entre cáncer mamario y aspersiones aéreas con malatión en Arica, Chile

Breast cancer mortality has been increasing in Arica Chile where it has surpassed the national rates 11 times between 1990 and 2010. The city of Arica was sprayed with the organophosphrous pesticide malathion in order to control the Mediterranean fly 33 years ago. Moreover we have demonstrated that a malathion treatment induces the formation of breast carcinomas in Sprague Dowley female rats. The objective of this work was to find a relationship between malathion aerial spraying and the increased mortality rate due to breast cancer that has been observed in Arica in recent years. We extracted city data bases with all breast cancer cases diagnosed from 1995 to 2005 from the Dr. Juan Noe Crevani Hospital of Arica city and Ernesto Torres Hospital of Iquique. The number of patients was 100 in Arica and 58 in Iquique, nearby city that has never been sprayed with malathion which had a similar population than Arica in those years. The statistical analysis of the characteristics of the sample related to breast cancer risk showed that there is no significant difference between women from Arica and from Iquique. Nevertheless the patients with more times of exposure to malathion were 5.7-times more likely to be diagnosed with breast cancer (OR= 5.7; p<0.02). In addition, metastases were found in 30.5 percent of the malathion-exposed group and only in 16 percent in the group never exposed (p<0.05). This study suggests that the increase in the mortality rate due to breast cancer occurring in Arica has a significant correlation with the exposure to malathion sprayed over the city more than 30 years ago.

La mortalidad por cáncer de mama ha ido aumentando en Arica Chile, donde ha sobrepasado las tasas nacionales 11 veces entre los años 1990 y 2010. La ciudad de Arica recibió aspersiones del pesticida organofosforado malatión, con el fin de controlar la mosca mediterránea, por primera vez hace 33 años. Por otra parte hemos demostrado que un tratamiento con malatión induce la formación de carcinomas mamarios en ratas hembras Sprague Dowley. El objetivo de este trabajo es encontrar una relación entre las aspersiones con malatión y el aumento en la tasa de mortalidad por cáncer de mama que se ha observado en Arica en los últimos años. Se extrajeron de bases de datos, los casos de cáncer mamario diagnosticados entre 1995 y 2005, en los Hospitales Dr. Juan Noé Crevani de Arica y Ernesto Torres de Iquique. El número de pacientes diagnosticados con cáncer de mama fue 100 en Arica y 58 en Iquique, ciudad que nunca fue fumigada con malatión y con una población similar a la de Arica durante esos años. El análisis estadístico de las características de la muestra, en relación a los factores de riesgo de cáncer mamario, mostró que no hay diferencia significativa entre las mujeres de Arica y de Iquique. Sin embargo, las mujeres con mayor tiempo de exposición al malatión fueron 5,7 veces más propensas a ser diagnosticadas con cáncer de mama (OR = 5,7, p <0.02). Además el 30,5 por ciento del grupo expuesto a malatión presentó metástasis y en el grupo no expuesto sólo el 16 por ciento (p <0.05). Este estudio sugiere que el aumento de la tasa de mortalidad por cáncer de mama que se ha producido en Arica tiene una correlación significativa con la exposición al malatión esparcido sobre la ciudad hace más de 30 años.

Malathion exposure and insulin resistance among a group of farmers in Al-Sharkia governorate.

OBJECTIVES: Exposure to certain environmental toxins may be associated with increased risk of developing diabetes mellitus. The aim of the present study was to investigate the relation between chronic exposure to malathion and insulin resistance among farmers. DESIGN AND METHODS: The study included 98 non diabetic farmers who handle agricultural insecticides during their field work. The range of the exposure period for agricultural pesticides was 15-20 years. All farmers were males with mean age 39±12 years. Another 90 administrative employees at Zagazig University Hospitals, non diabetic males age matched were selected as controls. History taking including family history for diabetes, assessment of blood pressure, height, weight, waist circumference and body mass index was done for all participants. Blood samples were withdrawn for measurement of malathion concentration, fasting blood glucose level and fasting insulin level for calculation of homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS: 24.5% had positive family history for diabetes. It was observed that there was a significant increase in the mean values of malathion blood concentration among studied farmers compared to corresponding controls. There was a positive correlation between malathion blood concentration, waist circumference and insulin resistance. It was also observed that the increase in the mean values of waist circumference and body mass index was accompanied by a significant increase in the mean values of malathion blood concentration. CONCLUSION: The current results suggested that chronic exposure of non diabetic farmers to organophosphorus malathion pesticides may induce insulin resistance. This effect tended to strengthen as waist circumference increases.

Insecticide resistance in head lice: clinical, parasitological and genetic aspects.

Insecticide treatment resistance is considered to be a major factor in the increasing number of infestations by head lice. The large insecticide selection pressure induced by conventional topical pediculicides has led to the emergence and spread of resistance in many parts of the world. Possible mechanisms of resistance include accelerated detoxification of insecticides by enzyme-mediated reduction, esterification, oxidation that may be overcome by synergistic agents such as piperonyl butoxide, alteration of the binding site, e.g. altered acetylcholinesterase or altered nerve voltage-gated sodium channel, and knockdown resistance (kdr). Clinical, parasitological and molecular data on resistance to conventional topical pediculicides show that treatments with neurotoxic insecticides have suffered considerable loss of activity worldwide. In particular, resistance to synthetic pyrethroids has become prominent, probably because of their extensive use. As other treatment options, including non-insecticidal pediculicides such as dimeticone, are now available, the use of older insecticides, such as lindane and carbaryl, should be minimized, owing to their loss of efficacy and safety concerns. The organophosphorus insecticide malathion remains effective, except in the UK, mostly in formulations that include terpineol.