22 research outputs found
Purification and characterization of cellulase from the wild-type and two improved mutants of Pseudomonas fluorescens
Cellulases from the wild-type (WT) and two improved mutants (catabolite repression resistant mutant 4 and 24, abbreviated CRRmt4 and CRRmt24, respectively) of Pseudomonas fluorescens were purified to apparent homogeneity by ammonium sulphate precipitation, ion exchange chromatography on DEAE Sephadex A-50 and gel filtration on Sephadex G-100. Purification fold of about 5 was obtained for the WT and CRRmt24 while purification fold of about 7 was achieved for CRRmt4 by ammonium sulphate precipitation. Ion exchange chromatography gave purification fold of about 24, 22 and 25 for WT, CRRmt4 and CRRmt24, respectively. Gel filtration chromatography step yielded a homogeneous preparation with a specific activity of 6.8, 5.9 and 6.9 units/mg protein for the WT, CRRmt4and CRRmt24, respectively. The purified cellulase gave a single protein band on polyacrylamide gel electrophoresis. The molecular weights of the three cellulases were estimated to be 36, 26 and 36 kDa for the wild-type,CRRmt4 and CRRmt24, respectively. Km values of 3.6, 3.1, and 5.3 mg/ml were obtained for the wild-type, CRRmt4 and CRRmt24, respectively. The optimum pH value for the purified cellulases was 6.5 – 7.0 andthe enzymes were optimally active at temperature of 35°C. The activities of the purified cellulases were stimulated by low concentrations (10-30 mM) of Na+ and Mg++ while EDTA was found to inhibit enzyme activity at all concentrations
Antihyperglycemic profile of erinidine isolated from Hunteria umbellate seed
Water decoction made from the seed of Hunteria umbellata is widely used in the traditional management of diabetes mellitus by Nigerian herbalists, particularly, in the southwest region of the country. Recently, a new bisindole alkaloid, erinidine, was isolated but its antihyperglycemic profile remains largely un-investigated scientifically. This forms the basis for the current study which is primarily designed at investigating the antihyperglycemic profile of erinidine and other fractions in both in vitro and in vivo models of diabetes mellitus. In the present study, erinidine was isolated and purified using the earlier described methods and its antihyperglycemic potentials tested in in vitro models such as dipeptidylpeptidase (IV), glycogen phosphorylase, HIT-T15 cell insulin secretion, glucose uptake activity, aldose reductase assays and ÆÂż-glucosidase inhibition assay testings. In addition, 50 mg/kg of erinidine and that of other fractions were evaluated in in vivo models of normal and chemically-induced hyperglycemic rats. Results showed that erinidine was a light yellow, amorphous solid with UV (CHCl3) ÆĂmax 256 nm, HRESIMSm/z 382.1881 [(M+H)+] (calculated for C22H26N4O2, 382.1876) and melting point of 230 oC. The in vitro study showed the antihyperglycemic action of erinidine to be weakly mediated via ÆÂż-glucosidase inhibition mechanism as the results for other in vitro tests such as dipeptidylpeptidase (IV), glycogen phosphorylase, HIT-T15 cell insulin secretion, glucose uptake activity and aldose reductase assays were all negative. However, the in vivo results showed 50 mg/kg erinidine given per os to normal and alloxan-induced hyperglycemic rats to significantly (p<0.05, p<0.001) attenuate an increase in their post-absorptive blood glucose concentrations after 3 g/kg glucose loading in the rats, suggesting its antihyperglycemic mechanism to be via ÆÂż-glucosidase inhibition. This result, although, further corroborated the in vitro findings but also suggests that erinidine needs to be biotransformed in vivo for its inhibitory activity on intestinal glucose absorption to become evident. Thus, the present study suggests erinidine to be the possible antihyperglycemic agent in Hunteria umbellata seed extract mediating its antihyperglycemic action via intestinal glucose uptake inhibition
Predicting youth participation in urban agriculture in Malaysia: insights from the theory of planned behavior and the functional approach to volunteer motivation
This study examines factors associated with the decision of Malaysian youth to participate in a voluntary urban agriculture program. Urban agriculture has generated significant interest in developing countries to address concerns over food security, growing urbanization and employment. While an abundance of data shows attracting the participation of young people in traditional agriculture has become a challenge for many countries, few empirical studies have been conducted on youth motivation to participate in urban agriculture programs, particularly in non-Western settings. Drawing on the theories of planned behavior and the functional approach to volunteer motivation, we surveyed 890 students from a public university in Malaysia about their intention to join a new urban agriculture program. Hierarchical regression findings indicated that the strongest predictor of participation was studentsâ attitude toward urban agriculture, followed by subjective norms, career motives and perceived barriers to participation. The findings from this study may provide useful information to the university program planners in Malaysia in identifying mechanisms for future studentsâ involvement in the program
Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.
BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44Â 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700
Anthropometrically determined nutritional status of children in public and private primary schools in Lagos, Nigeria
Background: Under-nutrition remains high while overweight/obesity are on the rise in developing countries. Little is known about the differences in the prevalence of malnutrition among public and private primary school children in urban areas of Lagos, Nigeria. This study determined and compared the nutritional status of children in public and private primary schools in an urban area of Lagos, Nigeria.Methods: A cross sectional study was conducted among public and private primary school children in an urban town in Lagos, Nigeria using multi-stage sampling technique to select 206 pupils. A structured interviewer administered questionnaire was used to obtain information on sociodemographic characteristics while anthropometric measures were obtained and compared to standards using WHO AnthroPlus, to determine the nutritional status.Results: The prevalence of underweight (WAZ <-2SD) in the public primary schools, 6.8% (n=7) was higher than in the private schools, 1.9% (n=2) but the difference was not statistically significant. (p = 0.085). However, the higher prevalence of stunting (HAZ <-2SD) in public (20.4% (n=24) compared to private schools 3.9% (n=4) was statistically significant (P<0.000). The prevalence of overweight and obesity were significantly higher among respondents in private schools (8.7% and 4.9%) compared to those in public schools (0.0% and 1.0% ) (p=0.0003).Conclusions: Stunting was higher in the public schools, while obesity and overweight were higher in the private schools. Appropriate feeding from birth should be promoted to prevent under-nutrition among children in public schools and overweight/obesity among children in private schools. Keywords: Anthropometry; Children; Nutrition; Stuntin
A guide to the Simulium damnosum complex (Diptera: Simuliidae) in Nigeria, with a cytotaxonomic key for the identification of the sibling species.
<title/> Although approximately 40% of all the people blinded by Onchocerca volvulus are Nigerians, almost nothing was known about the various cytospecies of the blackfly vectors present in Nigeria until 1981. The activation of the Nigerian National Onchocerciasis Control Programme in 1986 (and that programme's initiation of mass distributions of ivermectin in 1991) provided a significant stimulus to understand the biology of the Nigerian vectors but the exploration of any possible differences between the cytospecies has been hampered by a lack of accessible taxonomic information. This review attempts to satisfy that need. There are nine different cytoforms reliably recorded from Nigeria (Simulium damnosum s.s. Nile form, S. damnosum s.s. Volta form, S. sirbanum Sirba form, S. sirbanum Sudanense form, S. soubrense Beffa form, S. squamosum A, S. squamosum B, S. squamosum C and S. yahense typical form), and three more are known from surrounding countries and might be reasonably expected to occur in Nigeria. All of these cytospecies are presumed to be vectors, although there have been almost no identifications of the vectors of O. volvulus in Nigeria. The biogeographical distribution of the cytoforms is broadly similar to that known in other parts of West Africa (although many of the cytoforms remain insufficiently studied). The physico-chemical hydrology of the Nigerian breeding sites of the cytospecies does not, however, correspond to that seen elsewhere in West Africa, and it is not clear whether this might be related to differences in the cytoforms. An illustrated cytotaxonomic key is presented to facilitate and encourage future studies