Browsing by Author "Ngotho, M."
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Item Case Report: Lymphosarcoma in Adult African Green Monkeys (Chlorocebus(2007) Kagira, J. M.; Ngotho, M.; Thuita, J. K.; Jensen, H. E.; Hau, J.; Kenya Trypanosomiasis Research InstituteThe clinical observations and pathological manifestations of lymphosarcoma in two African green monkeys are described. Monkeys had been caught from the wild. Prior to the development of neoplasms one monkey had been experimentally infected with trypanosoma brucei rhodeslense as a model of human trypanosomiasis and subsequently treated with a proprietary trypanocidal drug and observed for any aftereffects. The other monkey was used to test for the safety of another trypanocidal drug. During the monitoring period term mated by euthanasia. Monkey became dull, unable to perch, and hunched. In the same animal the facial skin became hypersensitive and nodular skin lesions developed in the other animal used in safety study skin lesions. Weight loss and swollen eyelids were observed prior to euthanasia. During the terminal stages of the experimental protocol, the superficial lymph nodes of both al1lmals became swollen and the white blood cell count increased. Lesions disclosed during necropsy and subsequent histopathology revealed classical signs of nodular multicentric lymphosarcoma. In both al1lmals the neoplastic infiltrates were dominated by large lymphocytes with al1lsokaryosls and megakaryosis. In several organs (lungs. liver and kidneys) of one of the animals, the neoplastic infiltrates were accompanied by compression and degeneration of bordering tissues. The cause of the neoplasms remains unknown, but stress-induced Immunosuppression associated with captivity. To a lesser extent and more importantly the induction and treatment of experimental trypanosomiasis may, have triggered the onset of neoplastic proliferation, which IS frequently associated with simian T-cell leukemia virus I (STLV-l).Item A Fatal Outbreak of Campyiobacter jejuni Enteritis in a Colony of Vervet Monkeys in Kenya(2006) Ngotho, M.; Ngure, R. M.; Kamau, D. M.; Kagira, J. M.; Gichuki, C.; Farah, O. I.; Sayer, P. D.; Hau, J.; Kenya Trypanosomiasis Research InstituteIn a group of 50 wild-caught vervet monkeys trapped for experimental studies. 23 developed severe diarrhoea during the quarantine period. While 10 of these responded well to routine treatment with metronidazole, kaomycin and oral electrolytes, 13 initially showed slight improvement but later relapsed. Five of these failed to respond altogether and were euthanised. Fresh faecal samples were collected from the surviving eight monkeys and analysed for microbiology and drug sensitivity. Campylobacter jejuni. Sensitive to erythromycin, was isolated from all the faecal samples. Following treatment with erythromycin, seven monkeys recovered fully within ten days but one died before the end of therapy. This study indicates that wild non-human primates may play significant role as a reservoir of C jejuni, whereby they may act as natural carriers of this human pathogen. Screening for Campylobacter sp in newly acquired monkeys is advisable as part of the quarantine procedures.Item IL-10 is up regulated in early and transitional stages in vervet monkeys experimentally infected with Trypanosoma brucei rhodesiense(2006) Ngotho, M.; Maina, N.; Kagira, J.; Royo, F.; Farah, O. I.; Hau, J.; Kenya Trypanosomiasis Research InstituteIL-10 has been suggested as a possible parameter for human African trypanosomiasis stage determination. However, conclusive experimental studies have not been carried out to evaluate this, which is a prerequisite before a potential test can be validated in humans for diagnostic purposes. We used the vervet monkey model of trypanosomiasis to scrutinize IL-I 0 in blood and cerebrospinal fluid (CSF). Five adult males were experimentally infected with T. b. rhodesiense. The infected animals became anaemic and exhibited weight loss. Parasitemia was patent after 3 days and fluctuated around 3.7 x 107 trypanosomes/ml throughout the experimental period. The total CSF white cell counts increased from pre-infection means around 3 cells to a peak of 30 cells/!!I, 42 days post-infection (DPI). IL IO was not detectable «2 pgfml) in serum prior to infection. IL-IO serum concentrations increased to 273 pgfml 10 DPI coinciding with the first peak of parasitemia. Thereafter the levels declined to a mean value of77 pgfml 34 DPI followed by a significant rise to a second peak of304 pgfml (pItem Influence of Cyclophosphamide on the Haematological Profile of Laboratory Bred African Soft-furred Rats (Mastomys natalensis)(2005) Kagira, J. M.; Maina, N. W.; Thuita, J. K.; Ngotho, M.; Hau, J.; Kenya Trypanosomiasis Research InstituteThe African soft-furred rat (Mastomys natalensis) has been shown to be a possible model for propagation of Trypanosoma brucei gambiense. This study aimed at determining the baseline biological reference values and reproductive data of a laboratory bred Mastomys colony, which was established at TRC. In addition, the effect of cyclophosphamide (an immunosuppressant) treatment (s) on the haematological profile was investigated. The mean gestation period was 23 days and the mean better size was eight. At birth, the pups weighed 2.4±0.23 g and the weights increased to 78.0±10.6 g m males and 53.9±4.5 g in females by 90 days. The mean haematological values were significantly (p<0.05) higher in adults than juveniles. However, there was no statistical difference of haematological values between the sexes. Cyclophosphamide treatment caused a macrocytic hypochromic anaemia, which was noted 24 hours after Treatment and was more severe in animals treated more than once. Thus, in studies involving a disease that causes anaemia, repeated cyclophosphamide treatment should be limited. Our study is a contribution to the clinical and biological characterization of the disease pattern in this preferred rodent model of T b gambiense.Item Pathogenicity of bloodstream and cerebrospinal fluid forms of Trypanosoma brucei rhodesiense in Swiss White Mice(2008) Ndungu, K.; Ngotho, M.; Kinyua, J.; Kagira, J.; Guya, S.; Ndungu, J.; Murilla, G.; Kenya Trypanosomiasis Research InstituteTrypanosoma brucei rhodesiense (T.b.r.), the causative agent of the East African form of human African trypanosomiasis (HAT), is capable of crossing the blood brain barrier and invade the central nervous system (CNS). However, it is not clear whether bloodstream forms (BSF) of T.b.rhodesiense differ in biological characteristics from the cerebrospinal fluid (CSF) forms. The present study was carried out to compare the pathogenicity of CSF and BSF of T.b. rhodesiense parasites in Swiss white mice following intraperitoneal inoculation with 106 trypanosomes. The parasites were tested for presence of the serum resistance associated (SRA) gene. Parasitaemia, body weight, packed cell volume (PCV) and survival of the mice was monitored daily until the experiment was terminated. Data was analyzed using general linear model. Both forms of parasite were positive for the SRA gene, and there was no significant difference in progression of parasitaemia, PCV values or survival of the mice. However, the weights of BSF infected mice initially dropped faster than those of CSF infected mice (P<0.001). Key words: Trypanosoma brucei rhodesiense, bloodstream and CSF forms, pathogenicity, and mice.Item Use of TrypTectCIAA T to determine the effectiveness of treatment of Trypanosoma brucei r/lOdesiense infections in vervet monkeys (ChLorocebus aethiops) and man(2010) Karanja, S.M. ; Ngaira, J.M.; Thuita, J.K.; Ngotho, M.; Gichuki, C.W.; ; Kenya Trypanosomiasis Research Institute; Jomo Kenyatta University of Agriculture and Technology (JKUAT), Biochemistry, Kenya, Kenya Agricultural Research Institute, Trypanosomiasis Research Centre (KARI-TRC); UNDP/World Bank/WHOThe vervet monkey (Chlorocebus aethiops) model of sleeping sickness was used to evaluate the effectiveness of TrypTectCIATT in assessing the success of trypanocidal therapy. A retrospective study was therefore conducted on sera collected from monkeys infected with Trypanosoma brucei rhodesiense and treated either curatively with melarsoprol or sub-curatively with diminazene aceturate. In the human survey, 440 sera collected from 96 human patients were tested. These patients were treated with either surname or melarsoprol depending on the stage of the disease. An extra 56 parasitologically positive pre-treatment samples were also tested to aid in determination of the test sensitivity. Results indicated that between 21-28 days post-infection, the test detected trypanosomal antigens in 84.2% (16119) of animal samples that were parasitologically positive by the hematocnt centrifugation technique (RCT). In curatively treated animals, 77, 8% (7/9) exhibited positive reaction up to 9 months post-treatment. One animal was positive for trypanosomal antigens for the entire 12 months while one was a non-reactor from the sub-curatively treated group, 80% (8110) were detected positive for the entire 12 months while, 2 animals were non-reactors.In the human survey, 3 patterns of antigen profiles were observed. In some patients, there was fluctuation of antigen levels throughout the 12 months follow-up period. In others, antigens were detected for the entire 12 months but in decreasing levels. The last group was that of patients with antigens decreasing at different rates to undetectable levels at 12 months post-treatment. The presence of trypanosome positive but antigen negative samples during the study raises a few questions with regards to the sensitivity of the test. It is however evident that the test was able to detect trypanosomal antigens in over 80% of positive monkey and human serum samples. Consequently, TrypTectCIATT may be an important additional tool reduction of the follow-up period and determination of success of chemotherapy in sleeping sickness.
