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J. M. Njenga O. Bwangamoi E. K. Kangethe G. M. Mugera E. R. Mutiga 《Veterinary research communications》1995,19(4):295-308
Comparative transmission electron microscopy onBesnoitia besnoiti and on a strain ofBesnoitia derived from goats in Kenya revealed that the two organisms differ in their pellicle, micropore, microtubules, nucleus, wall-forming body 1 (W1), amount of lipids and amylopectin. Thus the caprine besnoitia is probably a different organism and the termBesnoitia caprae should continue to be used. 相似文献
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Avian pneumovirus (APV) causes a respiratory disease in turkeys. The virus has been associated with morbidity and mortality due to secondary infections. Our objective was to determine if APV caused immunosuppression in the T-cell or B-cell compartments and to study the pathogenesis of the disease in APV maternal antibody-lacking 2-wk-old commercial turkeys. APV was administered by the eyedrop/intranasal route. Observations were made for gross lesions, viral genome, and T-cell mitogenesis and cytokine secretion at 3, 5, 7, 14, and 21 days postinoculation (DPI). During the acute phase of the disease that lasted for about 1 wk, the turkeys exposed to APV showed clinical signs characterized by nasal discharge and sinus swelling. Virus genome was detected by in situ hybridization in cells of turbinates and trachea at 3 and 5 DPI. At 3 and 5 DPI, spleen cells of the birds infected with APV markedly decreased proliferative response to concanavalin A (Con A). Con A and lipopolysaccharide stimulation of spleen cells from virus-exposed turkeys resulted in accumulation of nitric oxide-inducing factors (NOIF) in the culture fluid. NOIF were not detected in culture fluids of Con A-stimulated spleen cells of virus-free turkeys. APV did not compromise the antibody-producing ability of turkeys against several extraneous antigens such as Brucella abortus and tetanus toxoid. 相似文献
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Lwamba HC Halvorson DA Nagaraja KV Turpin EA Swayne D Seal BS Njenga MK 《Avian diseases》2002,46(3):725-729
Earlier findings from our laboratory based on analysis of nucleotide and predicted amino acid sequence identities of 15 avian pneumoviruses (APVs) isolated from the United States (subgroup C) demonstrated that the viruses were phylogenetically separated from the European subgroup A and subgroup B viruses. Here, we investigated whether viruses from the three subgroups were cross-reactive by testing field sera positive for each of the APV subgroups in an enzyme-linked immunosorbent assay (ELISA) test with recombinant matrix (M) and nucleoprotein (N) proteins generated from a Minnesota APV isolate (APV/MN2A). Sera from turkeys infected with APV subgroup A, B, or C reacted with recombinant M protein derived from APV/MN2A. In contrast, recombinant N protein from APV/MN2A virus was reactive with sera from subtypes A and C viruses but not from subtype B virus. The results illustrate that viruses from the three APV subtypes share antigenic homology, and the M protein-based ELISA is adequate for monitoring APV outbreaks but not for distinguishing between different subtypes. 相似文献
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J. M. Njenga O. Bwangamoi E. R. Mutiga E. K. Kangethe G. M. Mugera 《Veterinary research communications》1993,17(3):203-208
Inoculation of cystozoites obtained from natural, chronic cases of caprine besnoitiosis produced clinical disease in goats but not in rabbits, mice, guinea pigs, hamsters, rats or cattle. Histological examination of tissue sections from the experimental animals showedBesnoitia cysts only in goats. This, together with field observations that cattle reared together with goats having besnoitiosis do not contract the disease, suggests that theBesnoitia species that infects goats in Kenya is host-specific and is notBesnoitia besnoiti. We suggest that the nameBesnoitia caprae be adopted for the caprine pathogen. 相似文献
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Urban agriculture, social capital, and food security in the Kibera slums of Nairobi, Kenya 总被引：1，自引：0，他引：1
Courtney M. Gallaher John M. Kerr Mary Njenga Nancy K. Karanja Antoinette M. G. A. WinklerPrins 《Agriculture and Human Values》2013,30(3):389-404
Much of the developing world, including Kenya, is rapidly urbanizing. Rising food and fuel prices in recent years have put the food security of the urban poor in a precarious position. In cities worldwide, urban agriculture helps some poor people gain access to food, but urban agriculture is less common in densely populated slums that lack space. In the Kibera slums of Nairobi, Kenya, households have recently begun a new form of urban agriculture called sack gardening in which vegetables such as kale and Swiss chard are planted into large sacks filled with topsoil. This paper examines relationships among sack gardening, social capital, and food security in Kibera. We used a mixed methods approach, combining qualitative interviews with a household survey, as well as focus group discussions with both farmers and non-farmers. We present evidence that sack gardening increases social capital, especially for those households that undertake sack gardening in groups. We also find that sack gardening in the Kibera slums has a positive impact on household food security by improving household dietary diversity and by reducing the need to resort to painful coping mechanisms that are used during food shortages. 相似文献
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Njenga MJ Kang'ethe EK Bwangamoi O Munyua SJ Mugera GM Mutiga ER 《Journal of the South African Veterinary Association》1999,70(4):161-163
Experimental transmission of Besnoitia caprae from naturally chronically-infected goats to susceptible ones was achieved by intra-nasal instillation and intra-conjunctival inoculation of cystozoite-containing suspensions, subcutaneous implantation of fascia containing cysts and alternate needle pricking between the infected and non-infected goats. Typical chronic symptoms developed in the fascia-infected does. Cystozoite inoculation into the eyes and mouth did not result in infection. Kids born of dams with acute and chronic besnoitiosis did not contract the infection in utero, suggesting that intra-uterine transmission may not occur. In contrast to does with acute besnoitiosis, which occasionally aborted, the does with chronic besnoitiosis gave birth to healthy kids. Kids below the age of 4 months (pre-weaned period) born of both infected and non-infected does were susceptible to besnoitiosis but appeared to be more resistant than adult goats. 相似文献
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Njenga MJ Munyua SJ Bwangamoi O Kang'ethe EK Mugera GM Mutiga ER Wamukoya JP 《Journal of the South African Veterinary Association》1999,70(4):151-153
A preliminary survey on the prevalence of besnoitiosis in domestic ruminants in Kenya based on field and farm visits, clinical and post mortem examinations and histopathological examination of tissues and biopsies, showed that goats are the most affected, followed by cattle, while sheep were unaffected. Caprine besnoitiosis occurred in a continuous belt in 5 of the 8 provinces in Kenya stretching from the Coast, Eastern, North Eastern, Nairobi and the Rift Valley Provinces. Mandera, in the North Eastern Province, had the highest prevalence rate of 36%, followed by Kwale (35%), Isiolo (35%), Marsabit (33%), Wajir (28%), Nairobi (26%), Meru (24%), Garissa (21%), Taita Taveta (18%), Embu (17%), Kitui (9%), Machakos (7%), Laikipia (3%), Kajiado (2%) and Turkana and Elgeyo-Marakwet (1% each). In all flocks where the prevalence rates were over 6%, kids were observed to be affected. There were no significant differences (P < 0.05) between the prevalence rates in bucks and does (18% and 18.4, respectively), but kids were less (4%) affected. Bovine besnoitiosis was found only in the Tana River District, with an infection rate of 11%. 相似文献