University of Nairobi

About: University of Nairobi is a education organization based out in Nairobi, Nairobi, Kenya. It is known for research contribution in the topics: Population & Health care. The organization has 6702 authors who have published 10777 publications receiving 231294 citations. The organization is also known as: UoN & IAU-020319.

Microarray analysis of HIV resistant female sex workers reveal a gene expression signature pattern reminiscent of a lowered immune activation state.

Abstract: To identify novel biomarkers for HIV-1 resistance, including pathways that may be critical in anti-HIV-1 vaccine design, we carried out a gene expression analysis on blood samples obtained from HIV-1 highly exposed seronegatives (HESN) from a commercial sex worker cohort in Nairobi and compared their profiles to HIV-1 negative controls. Whole blood samples were collected from 43 HIV-1 resistant sex workers and a similar number of controls. Total RNA was extracted and hybridized to the Affymetrix HUG 133 Plus 2.0 micro arrays (Affymetrix, Santa Clara CA). Output data was analysed through ArrayAssist software (Agilent, San Jose CA). More than 2,274 probe sets were differentially expressed in the HESN as compared to the control group (fold change ≥1.3; p value ≤0.0001, FDR <0.05). Unsupervised hierarchical clustering of the differentially expressed genes readily distinguished HESNs from controls. Pathway analysis through the KEGG signaling database revealed a majority of the impacted pathways (13 of 15, 87%) had genes that were significantly down regulated. The most down expressed pathways were glycolysis/gluconeogenesis, pentose phosphate, phosphatidyl inositol, natural killer cell cytotoxicity and T-cell receptor signaling. Ribosomal protein synthesis and tight junction genes were up regulated. We infer that the hallmark of HIV-1 resistance is down regulation of genes in key signaling pathways that HIV-1 depends on for infection.

Willingness of Kenyan HIV-1 serodiscordant couples to use antiretroviral-based HIV-1 prevention strategies.

Abstract: Introduction Antiretroviral treatment (ART) and pre-exposure prophylaxis (PrEP) have demonstrated efficacy as new human immunodeficiency virus-1 (HIV-1) prevention approaches for HIV-1 serodiscordant couples. Methods Among Kenyan HIV-1 serodiscordant heterosexual couples participating in a clinical trial of PrEP, we conducted a cross-sectional study and used descriptive statistical methods to explore couples' willingness to use antiretrovirals for HIV-1 prevention. The study was conducted before July 2011, when studies among heterosexual populations reported that ART and PrEP reduced HIV-1 risk. Results For 181 couples in which the HIV-1-infected partner had a CD4 count ≥350 cells per microliter and had not yet initiated ART (and thus did not qualify for ART under Kenyan guidelines), 60.2% of HIV-1 infected partners (69.4% of men and 57.9% of women) were willing to use early ART (at CD4 ≥350 cells per microliter) for HIV-1 prevention. Among HIV-1 uninfected partners, 92.7% (93.8% of men and 86.1% of women) reported willingness to use PrEP. When given a hypothetical choice of early ART or PrEP for HIV-1 prevention, 52.5% of HIV-1-infected participants would prefer to initiate ART early and 56.9% of HIV-1-uninfected participants would prefer to use PrEP. Conclusions Nearly 40% of Kenyan HIV-1-infected individuals in known HIV-1 serodiscordant partnerships reported reservations about early ART initiation for HIV-1 prevention. PrEP interest in this PrEP-experienced population was high. Strategies to achieve high uptake and sustained adherence to ART and PrEP for HIV-1 prevention in HIV-1 serodiscordant couples will require responding to couples' preferences for prevention strategies.

One-sided tests in shared frailty models

Abstract: Tests for the presence of heterogeneity in frailty models use an alternative hypothesis in which the heterogeneity parameter is subject to an inequality constraint. As a result, the classical likelihood ratio asymptotic chi-square distribution theory is no longer valid. Our main result states the limiting distribution of the likelihood ratio and score statistic for the one-sided testing problem. The resulting distribution is a mixture of chi-square distributed random variables. The results are shown for gamma and positive stable frailty distributions, and hold when covariate information is present. A data example illustrates the tests. We also assess, in a simulation study, the performance of the tests regarding the significance level and power.

Attitudes of nursing staff towards computerisation: a case of two hospitals in Nairobi, Kenya

Abstract: The health sector is faced with constant changes as new approaches to tackle illnesses are unveiled through research. Information, communication and technology have greatly transformed healthcare practice the world over. Nursing is continually exposed to a variety of changes. Variables including age, educational level, years worked in nursing, computer knowledge and experience have been found to influence the attitudes of nurses towards computerisation. The purpose of the study was to determine the attitudes of nurses towards the use of computers and the factors that influence these attitudes. This cross sectional descriptive study was conducted among staff nurses working at one public hospital (Kenyatta National Hospital, (KNH) and one private hospital (Aga Khan University Hospital (AKUH). A convenience sample of 200 nurses filled the questionnaires. Data was collected using the modified Nurses’ Attitudes Towards Computerisation (NATC) questionnaire. Nurses had a favorable attitude towards computerisation. Non-users had a significantly higher attitude score compared to the users (p = 0.0274). Statistically significant associations were observed with age (p = 0.039), level of education (p = 0.025), duration of exposure to computers (p = 0.025) and attitudes towards computerisation. Generally, nurses have positive attitudes towards computerisation. This information is important for the planning and implementation of computerisation in the hospital as suggested in other studies.

Fertilizer response and nitrogen use efficiency in African smallholder maize farms.

Abstract: Improving fertilizer recommendations for farmers is essential to increase food security in smallholder landscapes. Currently, blanket recommendations are provided across agro-ecological zones, although fertilizer response and nutrient use efficiency by maize crop are spatially variable. We aimed to identify factors that could help to refine fertilizer recommendation by analyzing the variability in fertilizer response (FR) and the agronomic nitrogen use efficiency (N-AE). A literature search for on-farm studies across Kenya and Sub-Sahara Africa (SSA), excluding Kenya, yielded 71 publications. The variability in FR was studied using a meta-analysis whereas key factors that influence FR and N-AE were studied with linear regression models. On average, the FR was 2, but it varied considerably from 1 to 28.5 (excluding outliers). In SSA, 18% of the plots were non-responsive plots with an FR < 1. The main factors affecting N-AE for Kenya were P-Olsen, silt content, soil pH, clay and rainfall, whereas only soil pH, exchangeable K and texture were important for SSA. However, our study indicates that available data on soil, climate and management factors could explain only a small part (< 33%) of the variation in FR and N-AE. Soil pH, P-Olsen, silt content, and rainfall had significant but low levels of power in explaining variation in FR and N-AE. Our findings indicate that strategies to refine fertilizer recommendation should include information on soil types and soil properties.