University of Nigeria, Nsukka

About: University of Nigeria, Nsukka is a education organization based out in Nsukka, Nigeria. It is known for research contribution in the topics: Population & Health care. The organization has 10211 authors who have published 13685 publications receiving 138922 citations.

The linamarase of Leuconostoc mesenteroides: Production, isolation and some properties

Abstract: Leuconostoc mesenteroides was found to produce highly active linamarase when linamarin was incorporated in its growth medium. The enzyme was isolated from the bacterium and partially purified using diethylaminoethyl (DEAE) cellulose. Its activity was measured spectrophotometrically using linamarin extract. This yielded 62.2 mg CN− g−1 of linamarin. A study of some of its properties showed it was active in the temperature range of -10 to +45°C, with an optimum at 29°2°C. Activity was observed over a wide pH range, 4.0–8.0, with optimum at 6.0–6.5. Its pH of stability was 5.5–7.5, while above pH 8.0 there was a rapid loss of activity. Incubating the enzyme at 50°C led to loss of over 90% of its activity within 18 min. The optimal substrate concentration was 0.15–0.20 ml−1. Whereas above 0.25 mg ml−1 there was no observable increase in activity, loss of activity became more pronounced below 0.10 mg ml−1 of substrate.

Management of esophageal foreign bodies: experience in a developing country.

Abstract: Background The outcome of esophagoscopy for removal of suspected esophageal foreign bodies (EFBs) is dependent on the FB characteristics and the surgeon’s experience. This study was conducted to review our experience and highlight challenges in the management of EFBs in a developing country. The value of radiologic signs in FB detection was also evaluated.

Assessment of the risks for human health of adenoviruses, hepatitis A virus, rotaviruses and enteroviruses in the Buffalo River and three source water dams in the Eastern Cape.

Abstract: Buffalo River is an important water resource in the Eastern Cape Province of South Africa. The potential risks of infection constituted by exposure to human enteric viruses in the Buffalo River and three source water dams along its course were assessed using mean values and static quantitative microbial risk assessment (QMRA). The daily risks of infection determined by the exponential model [for human adenovirus (HAdV) and enterovirus (EnV)] and the beta-Poisson model (for hepatitis A virus (HAV) and rotavirus (RoV)) varied with sites and exposure scenario. The estimated daily risks of infection values at the sites where the respective viruses were detected, ranged from 7.31 × 10(-3) to 1 (for HAdV), 4.23 × 10(-2) to 6.54 × 10(-1) (RoV), 2.32 × 10(-4) to 1.73 × 10(-1) (HAV) and 1.32 × 10(-4) to 5.70 × 10(-2) (EnV). The yearly risks of infection in individuals exposed to the river/dam water via drinking, recreational, domestic or irrigational activities were unacceptably high, exceeding the acceptable risk of 0.01% (10(-4) infection/person/year), and the guideline value used as by several nations for drinking water. The risks of illness and death from infection ranged from 6.58 × 10(-5) to 5.0 × 10(-1) and 6.58 × 10(-9) to 5.0 × 10(-5), respectively. The threats here are heightened by the high mortality rates for HAV, and its endemicity in South Africa. Therefore, we conclude that the Buffalo River and its source water dams are a public health hazard. The QMRA presented here is the first of its kinds in the Eastern Cape Province and provides the building block for a quantitatively oriented local guideline for water quality management in the Province.

Co-pyrolysis of macroalgae and lignocellulosic biomass

Abstract: Synergistic effect of co-pyrolysis of macroalgae [Enteromorpha prolifera (EP)] and lignocellulosic biomass [rice husk (RH)] in a fixed bed reactor for maximum and enhanced biofuels yield has been investigated. The main and interaction effects of three effective co-pyrolysis parameters (pyrolysis temperature, feedstock blending ratio, and heating rate) were also modeled and simulated to determine the yield rates of bio-oil and bio-char, respectively. Optimization studies were, then, performed to predict the optimal conditions for maximum yields using the central composite circumscribed experimental design in Design Expert® software 8.0.6. Analysis of variance was carried out to determine whether the fit of the multiple regressions is significant for the second-order model. Normal pyrolysis oils from EP, RH, and co-pyrolysis oils obtained from different feedstock blending ratios were examined using the gas chromatography-mass spectrometry to identify their compositions. Some vital properties of oils and bio-chars such as the heating value, water content, elemental compositions, and specific gravity were also determined, which unveiled that synergistic effect exists between EP and RH during co-pyrolysis, and this led to increase in products’ yields and improved co-pyrolysis products’ quality.

Functional analysis of drug resistance-associated mutations in the Trypanosoma brucei adenosine transporter 1 (TbAT1) and the proposal of a structural model for the protein.

Abstract: The Trypanosoma brucei aminopurine transporter P2/TbAT1 has long been implicated in the transport of, and resistance to, the diamidine and melaminophenyl arsenical classes of drugs that form the backbone of the pharmacopoeia against African trypanosomiasis. Genetic alterations including deletions and single nucleotide polymorphisms (SNPs) have been observed in numerous strains and clinical isolates. Here, we systematically investigate each reported mutation and assess their effects on transporter function after expression in a tbat1(-/-) T. brucei line. Out of a set of six reported SNPs from a reported 'resistance allele', none significantly impaired sensitivity to pentamidine, diminazene or melarsoprol, relative to the TbAT1-WT allele, although several combinations, and the deletion of the codon for residue F316, resulted in highly significant impairment. These combinations of SNPs, and ΔF316, also strongly impaired the uptake of [(3)H]-adenosine and [(3)H]-diminazene, identical to the tbat1(-/-) control. The TbAT1 protein model predicted that residues F19, D140 and F316 interact with the substrate of the transporter. Mutation of D140 to alanine resulted in an inactive transporter, whereas the mutation F19A produced a transporter with a slightly increased affinity for [(3)H]-diminazene but reduced the uptake rate. The results presented here validate earlier hypotheses of drug binding motifs for TbAT1.