Head and Neck Cancers four year trend at the Nairobi Cancer Registry

Background: Data on head and neck cancers is scarce in the developing countries including Africa. These cancers are more common in the Western countries. In the USA for instance, over 50,000 new cases occur annually. Head and neck cancers subtypes include oral cancers, oral pharyngeal cancers, larynx and nasopharyngeal cancers. Some of the associated causes of head and neck cancers include oncogenic viruses, irradiation, dietary factors and genetic predisposition. These cancers present a major challenge in their management due to their occurrence near vital structures of the head and neck region. Diagnosis or screening is difficult in the early stages due to the hidden nature of the lesions often resulting in late clinical presentation. Treatment modalities include surgery, radiotherapy and chemotherapy alone or in combination. Study Design: This was a retrospective study. Materials and Methods: We reviewed data from the population based Nairobi Cancer Registry (NCR) for the occurrence of Head and Neck Cancers (HNC’s) in relation to the frequencies of all cancers registered within the period between 2000-2003. We also determined the demographical, clinical and the histological features of these cancers. Results: For the period 2000-2003, head and neck cancers comprised over 12.8% (697) of all the 5462 cancers reported from all cancer sites with a male to female ratio of 2:1. Among the head and neck sub-sites, oral cancers were the highest at 40.6%, followed by nasopharynx and laryngeal cancers with 20.8% and 13.8 % respectively. The commonest histology was squamous cell carcinoma. Conclusion: According to the cancer cases registered with the Nairobi Cancer Registry within the analysed period, Head and neck cancers comprised of a significant problem of all the cancers. They are characterised by high rates of oral and nasopharyngeal cancers

Redefining the expressed prototype SICAvar gene involved in Plasmodium knowlesi antigenic variation

<p>Abstract</p> <p>Background</p> <p>The <it>SICAvar </it>gene family, expressed at the surface of infected erythrocytes, is critical for antigenic variation in <it>Plasmodium knowlesi</it>. When this family was discovered, a prototypic <it>SICAvar </it>gene was characterized and defined by a 10-exon structure. The predicted 205-kDa protein lacked a convincing signal peptide, but included a series of variable cysteine-rich modules, a transmembrane domain encoded by the penultimate exon, and a cytoplasmic domain encoded by the final highly conserved exon. The <it>205 SICAvar </it>gene and its family with up to 108 possible family members, was identified prior to the sequencing of the <it>P. knowlesi </it>genome. However, in the published <it>P. knowlesi </it>database this gene remains disjointed in five fragments. This study addresses a number of structural and functional questions that are critical for understanding <it>SICAvar </it>gene expression.</p> <p>Methods</p> <p>Database mining, bioinformatics, and traditional genomic and post-genomic experimental methods including proteomic technologies are used here to confirm the genomic context and expressed structure of the prototype <it>205 SICAvar </it>gene.</p> <p><b>Results</b></p> <p>This study reveals that the <it>205 SICAvar </it>gene reported previously to have a 10-exon expressed gene structure has, in fact, 12 exons, with an unusually large and repeat-laden intron separating two newly defined upstream exons and the <it>bona fide </it>5'UTR from the remainder of the gene sequence. The initial exon encodes a PEXEL motif, which may function to localize the SICA protein in the infected erythrocyte membrane. This newly defined start of the 205 <it>SICAvar </it>sequence is positioned on chromosome 5, over 340 kb upstream from the rest of the telomerically positioned <it>SICAvar </it>gene sequence in the published genome assembly. This study, however, verifies the continuity of these sequences, a 9.5 kb transcript, and provides evidence that the 205 <it>SICAvar </it>gene is located centrally on chromosome 5.</p> <p>Conclusion</p> <p>The prototype <it>205 SICAvar </it>gene has been redefined to have a 12-exon structure. These data are important because they 1) address questions raised in the <it>P. knowlesi </it>genome database regarding <it>SICAvar </it>gene fragments, numbers and structures, 2) show that this prototype gene encodes a PEXEL motif, 3) emphasize the need for further refinement of the <it>P. knowlesi </it>genome data, and 4) retrospectively, provide evidence for recombination within centrally located <it>SICAvar </it>sequences.</p

Tracing the Path of Technology Diffusion: The Case of Nturumenti, Narok, Kenya

An array of technologies; growing improved wheat varieties, bulking and collective marketing of wheat grains, sheep breed improvement, ram sharing, feedlot sheep fattening for market, strategic sheep deworming, pasture establishment and conservation practices; were introduced to members of a community based organization (CBO) in Nturumenti, anti-female genital mutilation and anti-poverty organization (AFAPO) in 2014. The CBO members, composed of youthful 19 men and 7 females, were intensively exposed and involved in the new skills both theoretically and practically in the farmers’ field school model. Even though the 8 farming technology options were suitable for the study environment, their adoption and diffusion varied. However, one of the introduced ideas, bulking and collective marketing of wheat grains, was not attempted for application by the farmers. Instead, the farmers felt that individual marketing of wheat grains immediately after harvesting was convenient and a quick way of recouping the invested funds particularly for the resource poor farmers in Nturumenti. In 2019, a follow-up study, conducted approximately 5 years after the exposure to determine the adoption and technology diffusion rate, it was observed that close to 80% of the agro-pastoral farming CBO members adopted more of the technologies associated with pasture establishment, production and conservation albeit the fact that they were lowly ranked in terms of awareness, at 13.3% for pasture establishment, synonymous to reseeding, and 16.7% for harvesting and conservation of cereal crop residues referred to as feeding of wheat straw during the ex-ante study. Indeed, the adopted ideas were practiced at commercial level and even diffused to non-CBO members. The findings indicate that even though, field demonstration exposed the farmers to a wide “menu” of technology options, the farmers, starting with the early innovators, adopted the technologies that mostly suited their needs and guaranteed to improve their livelihoods; and others farmers ‘imitated’ them

Distribution, characterization and the commercialization of elite Rhizobia strains in Africa

Grain legumes play a significant role in smallholder farming systems in Africa because of their contribution to nutrition and income security and their role in fixing nitrogen. Biological Nitrogen Fixation (BNF) serves a critical role in improving soil fertility for legumes. Although much research has been conducted on rhizobia in nitrogen fixation and their contribution to soil fertility, much less is known about the distribution and diversity of the bacteria strains in different areas of the world and which of the strains achieve optimal benefits for the host plants under specific soil and environmental conditions. This paper reviews the distribution, characterization, and commercialization of elite rhizobia strains in Africa

Assessment of knowledge of malaria and its control practices in mining and sugarcane growing regions of Western Kenya highlands

Background: Despite upscaled control efforts, deaths and hospitalization due to malaria remained high in counties of western Kenya highlands. Objectives: This study assessed the knowledge of malaria in two rural communities, the control strategies they use, and their capacity to integrate the available control programs. Methods: A cross-sectional survey was carried out in two rural villages in November – December 2018. Focus group discussions and a questionnaire survey were carried out in 736 households. Frequencies and proportions were used for descriptive analysis while the Chi-square test was used to determine factors that were associated with knowledge of malaria at p ≤ 0.05 Results: Ninety-seven percent of the respondents had knowledge of malaria and this was associated with the level of education attained (χ2 = 30.108; p &gt; 0.0001). Bed net ownership was at 86% and 92% correctly identified its use. Draining stagnant water (53.9%) was the most cited environmental management practice. Conclusion: There was awareness of the risk factors of malaria transmission in the study sites. The local communities must be mobilized and empowered through EIC for the control practises to bear fruit against malaria transmission. However, more sensitization needs to be done to optimize the use of malaria control practices.Keywords: Malaria; control practices; Kenya highlands; Mining

Weight gain and enteric methane production of cattle fed on tropical grasses

Context: Planted grasses are becoming an increasingly important feed resource for tropical smallholder ruminant production; yet, limited research has been conducted to quantify productivity or enteric methane (CH$_4$) production of animals consuming these grasses. Aim: An experiment was conducted to assess yields and nutritional attributes of the following three tropical grasses: Cenchrus purpureus var. Kakamega 1 (Napier), Chloris gayana var. Boma (Rhodes) and Urochloa brizantha var. Xaeres (Brachiaria), and quantify enteric CH$_4$ production of cattle fed on them. Methods: Yearling Boran steers (n:18; initial liveweight 216 ± 5.8 kg (mean ± s.e.m.) were allocated to one of three grasses, in a completely randomised design and fed ad libitum for two feeding periods, each period lasting for 70 days. Intake, liveweight (LW), apparent total-tract digestibility and enteric CH$_4$ production were assessed. The grasses used were grown on site and biomass yields were monitored over a 2-year period. Animal growth was also simulated to a final weight of 350 kg, and the amount of feed and size of land required to produce, and days to reach final weight, were estimated. Key results: Mean voluntary dry-matter intake (DMI) and ADG were higher (P 0.05) within period. Methane yield (MY; CH$_4$ g/DMI kg) was similar among treatments (26.7–28.5, P = 0.26) but Napier had a higher CH$_4$ conversion factor [Ym; CH$_4$ (MJ)/gross energy intake (MJ)] than did Rhodes and Brachiaria (0.0987 vs 0.0873 and 0.0903 respectively; P = 0.013). Our modelling indicated that steers consuming Rhodes took at least 30 more days to reach the target LW, required larger land area for feed production and produced more enteric CH$_4$ than did the other two diets. Conclusion: Even though animal performance and MY among treatments did not differ, the animals had higher MY and Y$_m$ than currently estimated by the Intergovernmental Panel on Climate Change. Implication: The three grasses supported similar animal growth rate, implying that growing of higher-yielding grasses such as Napier offers an opportunity to optimise land productivity in the tropics. However, suitable feeding practices such as protein supplementation need to be explored to enhance ruminant production and reduce enteric CH$_4$ production