Nucleoside exchange catalysed by the cytoplasmic 5''-nucleotidase.

The inhibition of the cytoplasmic 5'-nucleotidase (EC 3.1.3.5) by its product, inosine, was studied with a partially purified preparation of the enzyme from rat liver. Inhibition of Pi production was found to be due to exchange of the inosine moiety between inosine and IMP. Exchange was not catalysed by reversal of the hydrolytic reaction, suggesting, instead, the mediation of an enzyme-phosphate intermediate. Two models for the catalytic mechanism are proposed and rate equations for the dependence of Pi production on inosine concentration are derived. The experimentally determined dependence was consistent with a mechanism in which hydrolysis of the enzyme-phosphate intermediate occurred only when it was unoccupied by inosine. This conclusion suggests that inosine analogues that cannot participate in exchange should inhibit the enzyme. Such inhibitors might be useful in defining the enzyme's physiological role or as pharmacological agents to decrease breakdown of purine nucleotides. The possibility that nucleoside exchange provides an alternative route for the phosphorylation of mutagenic or cytotoxic nucleoside analogues should also be considered.     

The mechanism of adenosine production in rat polymorphonuclear leucocytes.

Adenosine production in intact rat polymorphonuclear leucocytes was studied during 2-deoxyglucose-induced ATP catabolism. A cell-free system containing the cytosolic 5'-nucleotidase (EC 3.1.3.5) as the only phosphohydrolase was also studied. The rate of adenosine formation in both intact cells and the cell-free system showed a similar dependence on energy charge (([ATP] + 1/2 [ADP]/([ATP] + [ADP] + [AMP])), being maximal only at values close to 0.8. Sufficient cytosolic 5'-nucleotidase was present in intact cells to explain the observed rate of adenosine formation. We conclude that the cytosolic 5'-nucleotidase is responsible for adenosine production in rat polymorphonuclear leucocytes. This mechanism provides a direct biochemical link between the energy status of a cell and the rate of adenosine formation.     

Malaria Infection Has Spatial,Temporal, and Spatiotemporal Heterogeneity in Unstable Malaria Transmission Areas in Northwest Ethiopia

Background

Malaria elimination requires successful nationwide control efforts. Detecting the spatiotemporal distribution and mapping high-risk areas are useful to effectively target pockets of malaria endemic regions for interventions.

Objective

The aim of the study was to identify patterns of malaria distribution by space and time in unstable malaria transmission areas in northwest Ethiopia.

Methods

Data were retrieved from the monthly reports stored in the district malaria offices for the period between 2003 and 2012. Eighteen districts in the highland and fringe malaria areas were included and geo-coded for the purpose of this study. The spatial data were created in ArcGIS10 for each district. The Poisson model was used by applying Kulldorff methods using the SaTScan™ software to analyze the purely temporal, spatial and space-time clusters of malaria at a district levels.

Results

The study revealed that malaria case distribution has spatial, temporal, and spatiotemporal heterogeneity in unstable transmission areas. Most likely spatial malaria clusters were detected at Dera, Fogera, Farta, Libokemkem and Misrak Este districts (LLR =197764.1, p<0.001). Significant spatiotemporal malaria clusters were detected at Dera, Fogera, Farta, Libokemkem and Misrak Este districts (LLR=197764.1, p<0.001) between 2003/1/1 and 2012/12/31. A temporal scan statistics identified two high risk periods from 2009/1/1 to 2010/12/31 (LLR=72490.5, p<0.001) and from 2003/1/1 to 2005/12/31 (LLR=26988.7, p<0.001).

Conclusion

In unstable malaria transmission areas, detecting and considering the spatiotemporal heterogeneity would be useful to strengthen malaria control efforts and ultimately achieve elimination.     

Increasing Trends of Diabetes Mellitus and Body Weight: A Ten Year Observation at Gondar University Teaching Referral Hospital,Northwest Ethiopia

Background

Diabetes mellitus is becoming one of the major causes of premature adult mortality in developing countries. However, there is a very little documentation of the morbidity trend in such countries.

Objective

To assess the ten-year trend of diabetes mellitus at Gondar University Teaching Referral Hospital, northwest Ethiopia.

Methods

A hospital-based retrospective record review was done at the main referral hospital in northwest Ethiopia. Data were obtained from medical records of all registered diabetic patients in the Diabetic Follow up Clinic between 2000 and 2009. An Extended Mantel-Haenzel chi-square test for the linear trend was used to examine the trend over time.

Result

Out of the total 354,524 patients who visited the Outpatient Department of the hospital during the study period, 1553 (4.4/1000) were diabetes patients, of which 50.1% was type 1 and 49.9% type 2 diabetes mellitus. The average increase in the proportion of both Type 1 and Type 2 diabetes mellitus cases between 2000 and 2009 was 125%. The mean (±SD) age for Type 1 diabetes mellitus was 29.1 (±12), and 53.5 (±12) for Type 2 diabetes. Overall 42.5% of the diabetes mellitus patients were female and 31.7% were rural residents. The mean body mass index for both type of diabetes mellitus increased from 15.9 to 18.3 kg for type 1 and from 23.8 to 24.6 for type 2 between 2000 and 2009, respectively.

Conclusion

The number of diabetes mellitus cases seen at Gondar Referral Hospital is rising steadily. A comprehensive diabetes prevention, treatment, and care program is needed to improve the quality of life of the increasing diabetes mellitus cases in Ethiopia.     

Reliability and Validity of an Interviewer-Administered Adaptation of the Youth Self-Report for Mental Health Screening of Vulnerable Young People in Ethiopia

Objective

Evaluate the reliability and validity of the Youth Self-Report (YSR) as a screening tool for mental health problems among young people vulnerable to HIV in Ethiopia.

Design

A cross-sectional assessment of young people currently receiving social services.

Methods

Young people age 15–18 participated in a study where a translated and adapted version of the YSR was administered by trained nurses, followed by an assessment by Ethiopian psychiatrists. Internal reliability of YSR syndrome scales were assessed using Chronbach''s alpha. Test-retest reliability was assessed through repeating the YSR one month later. To assess validity, analysis of the sensitivity and specificity of the YSR compared to the psychiatrist assessment was conducted.

Results

Across the eight syndrome scales, the YSR best measured the diagnosis of anxiety/depression and social problems among young women, and attention problems among young men. Among individual YSR syndrome scales, internal reliability ranged from unacceptable (Chronback’s alpha = 0.11, rule-breaking behavior among young women) to good (α≥0.71, anxiety/depression among young women). Anxiety/depression scores of ≥8.5 among young women also had good sensitivity (0.833) and specificity (0.754) to predict a true diagnosis. The YSR syndrome scales for social problems among young women and attention problems among young men also had fair consistency and validity measurements. Most YSR scores had significant positive correlations between baseline and post-one month administration. Measures of reliability and validity for most other YSR syndrome scales were fair to poor.

Conclusions

The adapted, personally administered, Amharic version of the YSR has sufficient reliability and validity in identifying young vulnerable women with anxiety/depression and/or social problems, and young men with attention problems; which were the most common mental health disorders observed by psychiatrists among the migrant populations in this study. Further assessment of the applicability of the YSR among vulnerable young people for less common disorders in Ethiopia is needed.     

A novel method for assessing gastritis in the murine model demonstrates genetically determined variation in response to Helicobacter felis infection

Background. In murine Helicobacter infection it has been demonstrated that the degree of gastric mucosal inflammation is determined by mouse strain. This is a valuable tool for investigating genetic, immunological or bacterial determinants for the outcome of human Helicobacter infection. This study aims to devise a robust method to facilitate these investigations. Materials and Methods. C57BL/6, BALB/c and (C57BL/6 × BALB/c) F1 mice were given 10⁸H. felis by gavage on days 1, 3 and 5 of the experiment Sections of the lesser and greater curve of stomach were examined at 12 weeks to assess active gastritis using a semi‐quantitative and a quantitative method by counting neutrophils in glands in four zones of the mucosa. Results. Semi‐quantitative scoring for active inflammation, based on the Sydney System, was inadequate with little discrimination between strains. Quantifying the level of active inflammation, counting the number of neutrophils in inflamed gastric glands and taking the total number of neutrophils in three inflamed pits within each zone (cardia, body, transitional zone and antrum) showed clear differences between the two parental strains for the degree of active gastritis and furthermore, using this system the phenotype of the (C57BL/6 × BALB/c) F1 was found to be between the two parental extremes. Conclusions. This novel method provides a numerical value for active inflammation in the stomach that is accurate, reproducible and discriminatory.     

Grasshopper assemblage response to a restored national park (Mountain Zebra National Park, South Africa)

Twelve grassland sites were sampled inside and outside the Mountain Zebra National Park (MZNP), South Africa to assess changes in grasshopper assemblages to grazing by indigenous mammals inside the park compared to grazing by domestic cattle outside. The MZNP has been restored from cattle-grazed farmland to indigenous mammal parkland for 62 years. The number of grasshopper species and families inside the park was not significantly different from outside the park, but the number of individuals inside the park was significantly higher. Multivariate statistics did not reveal any strong site groupings based on simple inside/outside comparisons, but there were clear groupings of sites based on vegetation characteristics and other environmental variables. The park boundary, therefore, does not significantly determine grasshopper assemblages, although intensity of grazing does. The indigenous mammals inside the park had the same effect on grasshoppers as the domestic cattle outside, and it was the level of defoliation and trampling that was important rather than the type of mammal. Intensive livestock grazing and trampling leads to bush encroachment and reduction in grass cover and/or disappearance of several grass species. In response to this pressure, grasshopper populations dropped, with localized extirpation of some species. Vegetation composition and structure, particularly grass height and percentage cover, had a significant effect on grasshopper assemblages. The MZNP is thus an area of localized, elevated grasshopper abundance in comparison with the surrounding farms, and presumably represents a situation prior to the current, intensive farming activities. Such elevated grasshopper abundances are important for maintaining soil quality and hence ecological integrity of this landscape which is poor in organics and nitrogen. The MZNP could be viewed as a centre where species with high mobility may seek refuge from anthropogenic pressures. The MZNP also serves as a reference illustrating the differences between restored-through-natural-succession and anthropogenically disturbed habitats, and compares desirable with undesirable ecosystem changes for herbivorous invertebrates such as grasshoppers.     

Household Contact Screening Adherence among Tuberculosis Patients in Northern Ethiopia

BackgroundHousehold contacts of active tuberculosis cases are at high risk of getting tuberculosis disease. Tuberculosis detection rate among contacts of household members is high. Hence, this study investigated household contact screening adherence and associated factors among tuberculosis patients in Amhara region, Ethiopia.MethodsA cross-sectional study was conducted from April 10 - June 30, 2013 in five urban districts of Amhara region, where 418 patients receiving treatment at tuberculosis clinic were interviewed. All patients were interviewed using structured and pre-tested questionnaire. Bringing at least one household contact to TB clinic was regarded as adherent to household contacts screening. Bivariate and multiple logistic regressions were used to investigate association.ResultsThe overall adherence to household contact screening in Amhara region was 33.7%. Adherence was higher among Muslims than Christians. Adherence was high if patient took health education from Health Care Worker [AOR: 3.22, 95% CI: 1.88 to 5.51] and 2.17 times higher if patient had sufficient knowledge on tuberculosis [AOR: 2.17, 95% CI: 1.29 to 3.67] during interview. Relationship with contact was a significant [AOR: 0.4, 95% CI: 0.2 to 0.9] social related factor.ConclusionOne third of tuberculosis patients adhered to household contact screening in health facilities during their treatment course. Promoting knowledge of tuberculosis in the community and continuous health education to tuberculosis patients are recommended.     

Field-based investigation on phytoremediation potentials of Lemna minor and Azolla filiculoides in tropical,semiarid regions: Case of Ethiopia

This study investigated the concurrent accumulation of eight heavy metals by two floating aquatic macrophytes (Lemna minor and Azolla filiculoides) cultivated in ambient media and blended wastewaters in the semiarid regions of Ethiopia. Both species accumulated heavy metals in varying degrees with a significant concentration gradient within the immediate water media. Highest bioconcentration factor (BCF) was determined for Mn and Fe in both plants. Results revealed that L. minor was high phytoaccumulator for Fe, Mn, Zn, and Co but moderate for Cd, Cu, Ni, and Cr. On the other hand, A. filiculoides was a high accumulator for Fe, Mn, Zn, and Cu, but its potency was moderate for Co, Cr, and Ni, but lower for Cd. Both species exhibited significant difference in accumulating Co, Zn, and Mn (p < 0.05). In general, the BCFs for both plants were comparable within the same treatment. In this study, stronger associations between the heavy metal concentrations in the plant tissues and in the grown water media were observed for A. filiculoides.     

Suitability of nutrients removal from brewery wastewater using a hydroponic technology with <Emphasis Type="Italic">Typha latifolia</Emphasis>

Background

This study aims to assess suitability of hydroponic technology for treatment of brewery wastewater in a hydroponic bioreactor using Typha latifolia. Triplicated hydroponic bioreactor treatment units were designed, constructed and operated at a hydraulic retention time of 5?days with different surface loadings and mean hydraulic loading rate 0.023?m³ m^?2d^??1. Young T. latifolia shoots were collected in the vicinity of study site. Wastewater characteristics, plant growth and nutrient accumulation during experiment were analyzed as per APHA standard methods and nutrient removal efficiency was evaluated based on inlet and outlet values.

Results

T. latifolia established and grew well in the hydroponics under fluctuations of wastewater loads and showed a good phytoremedial capacity to remove nutrients. Significant removal efficiencies (p?<?0.05) varied between 54 and 80% for Total Kjeldahl Nitrogen, 42 and 65% for NH₄⁺ -N, 47 and 58% for NO₃^? -N, and 51 and 70% for PO₄^3?-P. The system improved the removal up to 29% compared to control and produced biomass of 0.61–0.86?kg dry weight (DW) m^??2. Nutrients retained were up to 21.17?g?N?kg^??1 DW and 2.87?g P kg^??1 DW.

Conclusion

The significant nutrients reduction obtained and production of biomass led us to conclude that hydroponics technology using T. latifolia has suitability potential for treatment of brewery wastewater and similar agro-industrial wastewaters. Thus it could be considered as a promising eco-friendly option for wastewater treatment to mitigate water pollution. Integration of treatment and production of biomass needs further improvement.