Residues of organochlorine pesticides in human milk

A research paper on residue of pesticides in human milk.Levels of residues of chlorinated hydrocarbons p,p-DDT, p,p-DDE, p,p-TDE, x-, B-, y-hexachlorocyclohexane (HCH), heptachlor epoxide, dieldrin and polychlorinated biphenyls (PCBs) in the milk of 40 Zimbabwean mothers living in the Greater Harare area were analysed. Of all the milk samples analysed, relatively low residue levels of x-, B-, and v-HCH, peptochloroperoxide and dieldrin were detected in 58, 100, 63, 13 (not statistically significant) and 65 per cent respectively. Traces of the PCB congener 2,2,4,5,5 -penta- chlobipheny (PCB 101) were found in 15 samples. One sample contained traces of 2,3',4,4',5-pentachlorobiphenyl (PCB 118). From this study, small though the sample was, it seems social status, educational background and living conditions are important demographic variables influencing the frequency distribution of residue levels of sum DDT in the mother’s milk

Metabolism of pesticides

A research paper on how pesticides infiltrate the biological systems of living organisms.The metabolism of pesticides, like that of many other chemicals, takes place mainly in the liver, skin, gastrointestinal tract, kidneys and lungs. These organs have the capacity to bring about enzymatic reactions of metabolism. In this chapter, metabolism of pesticides is exemplified by the metabolic pathways of the organochlorine, DDT, and the organophosphate, parathion. Metabolism means more than just one thing. On one hand, the chemical and enzymatic reactions and processes that maintain the existence of any organism may be referred to as metabolism. On the other hand, metabolism may mean the conversion or transformation of chemical substances foreign and endogenous to an organism by chemical or enzymatic reactions in the organism. “Foreign compounds" refers to non-nutrient substances to a specific organism. Pesticides may enter the body by way of ingestion in food or drink, inhalation, through the eyes or by absorption through the skin (Neal, 1975). The metabolism of pesticides, that is, the total fate of pesticides in the body, including their absorption, distribution, biotransformation and excretion like that of other foreign substances is handled in the body by certain organs. Although the liver is perhaps the major organ involved in metabolism of chemicals, the kidney, skin, the gastrointestinal tract (GIT) and the lungs are all involved in metabolism too (Briggs and Briggs, 1974). A more detailed account of the mechanisms of metabolism is presented by Williams (1959) and La du et al. (1971)

Occupational exposure to DDT among the mosquito-control sprayers in Zimbabwe

A research paper on occupational health problems in the seasonal spraying business due to DDT exposure in Zimbabwe.Four hundred and eighty DDT seasonal spray-men were screened for DDT exposure over the period September to March in 1988, 1989 and 1990. The average age of the spray-men was 29 ± 8,5 (range 19-61 years). Their average weight was 62,8 ± 4,7 kg with a range of 44-129 kg. Ninety per cent of the men were between the age of 21 and 50 years. Up to 49 per cent of the spray-men showed evidence of DDT exposure with DDE plasma levels greater than 1,00 pg per 100 ml and vitamin A levels greater than 0,92 mg per litre. Smoking seems to predispose the workers to toxic exposure with 76 per cent of the smokers showing vitamin A levels above normal compared to 58 per cent non- smokers. Forty-eight percent of the men were on medication during the spraying period, the significance of which was not evaluated in this study. The study indicated an unacceptably high magnitude of toxic exposure to DDT among spray-men

Warfarin Pharmacogenomics for Precision Medicine in Real-Life Clinical Practice in Southern Africa: Harnessing 73 Variants in 29 Pharmacogenes

Pharmacogenomics is universally relevant for worldwide modern therapeutics and yet needs further development in resource-limited countries. While there is an abundance of genetic association studies in controlled medical settings, there is a paucity of studies with a naturalistic design in real-life clinical practice in patients with comorbidities and under multiple drug treatment regimens. African patients are often burdened with communicable and noncommunicable comorbidities, yet the application of pharmacogenomics in African clinical settings remains limited. Using warfarin as a model, this study aims at minimizing gaps in precision/personalized medicine research in African clinical practice. We present, therefore, pharmacogenomic profiles of a cohort of 503 black Africans (n = 252) and Mixed Ancestry (n = 251) patients from Southern Africa, on warfarin and co-prescribed drugs in a naturalized noncontrolled environment. Seventy-three (n = 73) single nucleotide polymorphisms (SNPs) in 29 pharmacogenes were characterized using a combination of allelic discrimination, Sanger sequencing, restriction fragment length polymorphism, and Sequenom Mass Array. The common comorbidities were hypertension (43-46%), heart failure (39-45%), diabetes mellitus (18%), arrhythmia (25%), and HIV infection (15%). Accordingly, the most common co-prescribed drugs were antihypertensives, antiarrhythmic drugs, antidiabetics, and antiretroviral therapy. We observed marked variation in major pharmacogenes both at interethnic levels and within African subpopulations. The Mixed Ancestry group presented a profile of genetic variants reflecting their European, Asian, and African admixture. Precision medicine requires that African populations begin to capture their own pharmacogenetic SNPs as they cannot always infer with absolute certainty from Asian and European populations. In the current historical moment of the COVID-19 pandemic, we also underscore that the spectrum of drugs interacting with warfarin will likely increase, given the systemic and cardiovascular effects of COVID-19, and the anticipated influx of COVID-19 medicines in the near future. This observational clinical pharmacogenomics study of warfarin, together with past precision medicine research, collectively, lends strong support for incorporation of pharmacogenetic profiling in clinical settings in African patients for effective and safe administration of therapeutics