University of Zimbabwe

About: University of Zimbabwe is a education organization based out in Harare, Harare, Zimbabwe. It is known for research contribution in the topics: Population & Acquired immunodeficiency syndrome (AIDS). The organization has 4378 authors who have published 6800 publications receiving 160720 citations. The organization is also known as: UZ & University College of Rhodesia and Nyasaland.

Application of higher throughput screening (HTS) inhibition assays to evaluate the interaction of antiparasitic drugs with cytochrome P450s.

Abstract: In this study we have evaluated the application and reliability of using fluorescence (FLUO)-based high throughput screening assays with recombinant CYPs (rCYP). This was accomplished by screening 29 clinically important antiparasitic drugs for inhibition of the five major drug-metabolizing CYPs (-1A2, -2C9, -2C19, -2D6, and -3A4). Data from FLUO/rCYP assays were compared with that obtained by conventional HPLC assays using human liver microsomes (HLM) and rCYPs. The K(i) values showed good correlations: FLUO/rCYP and HPLC/rCYP (r(2) = 0.81), HPLC/rCYP and HPLC/HLM (r(2) = 0.82), and FLUO/rCYP and HPLC/HLM (r(2) = 0.72). Niclosamide had substrate-dependent contrasting effects on CYP2C9 activity with an apparent activation (400%) of 7-methoxy-4-trifluoromethylcoumarin demethylase activity and potent inhibition (K(i) = 6.00 microM) of diclofenac 4-hydroxylase activity. Potent inhibitors of CYP1A2 were artemisinin, dihydroartemisinin, thiabendazole, primaquine, and niclosamide (K(i) = 0.43, 3.67, 1.54, 0.22, and 2.70 microM, respectively). Proguanil, cycloguanil, amodiaquine, and desethylamodiaquine inhibited CYP2D6 (K(i) = 6.76, 5.97, 2.1, and 4.13 microM, respectively). Considering the C(max) of these drugs, artemisinin, thiabendazole, primaquine, amodiaquine, and desethylamodiaquine may cause clinically important interactions because they are predicted to inhibit 67 to 99% of the activities of the CYPs they interact with. In addition, our results suggest CYP1A2 inhibition as the mechanism behind the observed thiabendazole/theophylline and primaquine/antipyrine interactions in vivo.

Cancer of the uterine cervix may be significantly associated with A gene polymorphism coding for increased IL-10 production

Abstract: The purpose of our prospective, case-controlled study was to investigate the hypothesis that women who are genetically programmed to produce high or medium levels of IL-10 were more likely to develop cancer of the uterine cervix than individuals genetically predisposed to low IL-10 production. The population was recruited from patients attending gynecological clinics at 2 hospitals in Harare, Zimbabwe. Laboratory tests were performed in the Departments of Immunology, Chemical Pathology and Medical Microbiology, Medical School, University of Zimbabwe, and simultaneously at the Department of Biological Sciences, University of Manchester, United Kingdom. Included in our study were 77 women with histologically proven cancer of the uterine cervix and 69 age- and parity-matched healthy women. All of the patients and healthy controls were from the Shona ethnic group that inhabits northern Zimbabwe. DNA was purified from cervical cytobrush samples obtained from women with cervical cancer. Control DNA was extracted from urine or peripheral blood samples from the healthy women. The Qiagen DNA extraction kit was used. Detection of allele A and/or G at −1082 in the promoter region of the IL-10 gene was carried out using the ARMS-PCR technique. Polymorphism in the amplified products was detected by gel electrophoresis in the presence of ethidium bromide and were bands visualized under UV light. The data comprise 77 women who developed invasive cervical cancer and 69 healthy women matched for age and parity. Patients with cancer were significantly (p = 0.001) more likely to be predisposed to produce higher (A/G) levels of IL-10. The genotype encoding for high (G/G) production of IL-10 was only observed in one cancer patient. The prevalence of low producers of IL-10 in the cancer group was significantly lower than in the healthy women. There were no high producers amongst the healthy women. These data suggest that the genetically acquired ability to produce higher levels of IL-10 may be a significant factor in the development of cervical cancer. © 2001 Wiley-Liss, Inc.

Schistosoma haematobium Treatment in 1–5 Year Old Children: Safety and Efficacy of the Antihelminthic Drug Praziquantel

Abstract: Background: Morbidity due to schistosomiasis is currently controlled by treatment of schistosome infected people with the antihelminthic drug praziquantel (PZQ). Children aged up to 5 years are currently excluded from schistosome control programmes largely due to the lack of PZQ safety data in this age group. This study investigated the safety and efficacy of PZQ treatment in such children. Methods: Zimbabwean children aged 1-5 years (n = 104) were treated with PZQ tablets and side effects were assessed by questionnaire administered to their caregivers within 24 hours of taking PZQ. Treatment efficacy was determined 6 weeks after PZQ administration through schistosome egg counts in urine. The change in infection levels in the children 1-5 years old (n = 100) was compared to that in 6-10 year old children (n = 435). Principal Findings: Pre-treatment S. haematobium infection intensity in 1-5 year olds was 14.6 eggs/10 ml urine and prevalence was 21%. Of the 104 children, 3.8% reported side effects within 24 hours of taking PZQ treatment. These were stomach ache, loss of appetite, lethargy and inflammation of the face and body. PZQ treatment significantly reduced schistosome infection levels in 1-5 year olds with an egg reduction rate (ERR) of 99% and cure rate (CR) of 92%. This was comparable to the efficacy of praziquantel in 6-10 year olds where ERR was 96% and CR was 67%. Interpretation/Significance: PZQ treatment is as safe and efficacious in children aged 1-5 years as it is in older children aged 6-10 years in whom PZQ is the drug of choice for control of schistosome infections.