Orotic Aciduria

Orotic acid is an intermediate found in the pathway for pyrimidine synthesis. The mitochondrial enzyme dihydroorotate dehydrogenase (DHODH) catalyzes the production of orotic acid by the conversion of the compound dihydroorotate to orotic acid. Orotic acid is commonly produced by this reaction in erythrocytes, hepatocytes, and kidney cells. Chemical modification of orotic acid in the pyrimidine pathway will generate nucleotides involved in DNA and RNA synthesis. Orotic aciduria can occur as a secondary manifestation due to a defect in an enzyme or transporter within the urea cycle, due to competitive inhibition by anti-cancer drugs such as allopurinol and 6-azauridine, or due to diseases such as Reye’s syndrome and mitochondrial disorders. The primary cause of orotic aciduria is a rare, autosomal recessive disorder in the family of inborn errors in metabolism, and can be categorized into three groups. Type I, II, and III orotic aciduria occur due to a genetic defect in the bifunctional enzyme uridine monophosphate synthase (UMPS). Neonatal patients diagnosed with this disorder commonly exemplify symptoms such as lethargy, difficulty feeding, and low birth weight and height. Neural and developmental deficits, megaloblastic anemia, and crystalluria may also occur. Laboratory findings typically include extremely high urinary orotic acid levels, megaloblastic anemia, and very low UMPS activity. Since early treatment with Xuriden may cause remission of symptoms, future studies should focus on improving early detection screening methods. Early diagnosis and treatment is clinically significant because impaired pyrimidine synthesis can lead to severe symptoms such as mental retardation, coma, or death

Mapping and valuation of ecosystems and economic activities along the coast of Cameroon: implications of future sea level rise.

The vulnerability of the coastal zone of Cameroon to flooding from sea level rise (SLR) was quantified using Geographic Information System (GIS) flooding analysis. The main economic activities and ecosystems along this area were iden tified using secondary data. Valuations of non- market values of ecosystems were based on the ecosystem service product method. The low-lying coastal areas were found to be physically and socio-economically susceptible to impacts of SLR due to their high ecological and economic value. A digitised land use/land cover (LULC) classification was produced from low resolution topographic maps and Google Earth images of the area. The digital elevation model (DEM) used was acquired by the shuttle radar topography mission. Evaluation of potential land loss due to inundation was based on empirical approaches using minimum and maximum scenarios of 2 and 10 m flooding. These were estimated considering the best available SLR data for the area, mean high water levels and wave heights during storms. The estimated SLR range from 2.3 m to 9.2 m for the low and high scenarios, respectively, by 2050 and from 2.6 m to 9.7 m for the low and high scenarios, respectively, by the year 2100. Results indicate that 112 km 2 (1.2 %) and 1,216 km 2 (12.6 %) of the coastal area will be lost from a 2 m (equivalent to a low scenario by 2050) and 10 m (equivalent to a high scenario by 2100) flooding, respectively. 0.3 % to 6.3 % of ecosystems worth US$ 12.13 billion/yr could be at risk of flooding by the years 2050 and 2100. The areas under a serious threat cont ain mangroves, sea and airport, residential and industrial areas of Douala. Main plantation crops of banana and palms will be slightly affected. The identification of the soci o-economic impacts of projected SLR on vulnerable coastlines and populations is important for timely actions to be taken in mitigating the effects of natural disasters in the coastal zone

Applying Relativity in Understanding Poverty and Promoting Economic Development in Rural Africa

Combating poverty remains a major hindrance to economic development across Africa, even though it is well known that the poor are generally concentrated in rural areas. Paradoxically, identifying and targeting development efforts to the (very) poor remains a major challenge, mainly due to data deficiency and the wide application of popular but poorly adapted absolute poverty assessment approaches. This paper succinctly revisits the comparative advantages of relative over absolute poverty measures, and their prospects for application in rural Africa. Claims in favour of the relative approach are then substantiated by its application to empirically elicit poverty distribution among households in rural Cameroon. Analytical results fundamentally based on principle component analysis strengthen our advocacy for a dominant application and better prospects for relative poverty assessments over absolute ones, especially in rural areas of developing countries such as Cameroon, where data unavailability persists. In addition, the holistic and multi-dimensional attributes embedded in the relative approach oblige an atonement of its overarching prospects for identifying and targeting the poor in order to fight poverty and enhance economic development, especially in rural areas in Africa, as demonstrated in the   Cameroonian case study.  Key words: Poverty, relative assessment, economic development, rural areas, Africa, Cameroo

Gestion intégrée des ressources en eau dans le bassin versant du lac municipal de Dschang : connaissance et usages

Le développement des ressources en eau du sous-bassin du lac municipal de Dschang suscite un intérêt croissant. En prélude à l'élaboration d'une stratégie de gestion durable de l'eau du sous-bassin, un état de lieux a été réalisé et les effets des variations climatiques sur les ressources en eau analysés. Les données climatiques sur la période 1978-2008, les données secondaires des études antérieures et les données des prélèvements en eau effectués par la Camerounaise des Eaux ont été analysées. Ces données ont été complétées par des informations observées sur le terrain et collectées lors des entretiens avec des acteurs clés. Les ressources naturelles en eau de surface ont été estimées à 24 Mm3. Seulement 2% des eaux de surfaces sont prélevées (0.48 Mm3), tandis que la capacité du seul réservoir dans le bassin est de 0.45 Mm3. Il y a un potentiel d’usage pour la production hydroélectrique en aval du réservoir. La qualité microbiologique du lac laisse à désirer pendant certaines périodes de l’année. La pluviométrie montre une tendance à la baisse d’environ 2% comparée au module interannuel. Les principaux problèmes identifiés sont la faible coordination des acteurs impliqués dans la gestion, l’envasement de la retenue et le manque de données fiables pour une meilleure prise des décisions. Pour une gestion durable, une approche holistique basée sur les principes de la gestion intégrée des ressources en eau devrait être adoptée.Mots clés : Gestion intégrée, connaissance et usages de l’eau, état des lieux et changement climatique

Stakeholder Perception of Global Warming, Rainfall Variability and Sea Level Rise Hazard Perils in Three Coastal Districts of Douala-Cameroon

Present day climate change scientist fully embrace the concept of global warming and have repeatedly pointed out that a solution to global warming problem requires studies on climate change education, awareness and proper understanding of causes and impacts. The present study was designed to assess the level of knowledge and awareness of inhabitants of three sub divisions of Douala on the impacts of SLR hazards. 1200 questionnaires were administered to inhabitants of Douala I, IV and V by stratified purposive sampling technique. The Chi square (X2) statistical tests were performed to compare responses to survey questions across sub divisions as well as across demographic groups. The Cramer’s V test (nonparametric correlation) was performed to detect strength of associations of causes and impacts of global warming, rainfall variability, sea level rise perception and social determinants. Correlates of perception of global warming, rainfall variability, sea level rise and water quality parameters and environmental hazards were also assessed. Results show that awareness and perception to global warming, yearly variation of rainfall and knowledge of sea level rise were highly significant (p˂0.000) across districts. The Douala V inhabitants (37.8 %) were more aware of global warming and bothered about its impact than Douala IV and I respondents. Douala V respondents perceived that human beings are linked to the causes of global warming, rainfall variability and sea level rise than Douala I and IV. The Douala IV respondents were more knowledgeable in terms of SLR (37 %) than Douala I and V respondents. Impacts of exaggerated heat wave and increase in floods had significant differences across the district (p˂0.000). Sources of water during the rainy season (rivers/streams, wells, rainfall) were highly significant while differences in the use of water resources for domestic purposes across the three districts were also significant. Flooding and tidal effects were perceived to be the most devastating hazards in Douala I, IV and V as they were highly significant (p˂0.000). Highly significant association (P˂0.01) between the perceived human causes of sea level rise and knowledge of it for Douala I and IV were observed. Rising water tables, inundation, changed colour of water and odour of water as impacts of sea level rise were associated with the taste of water sources. The most devastating hazards were tidal effects and flooding (39 % each) for Douala IV and wave action (44 %) for Douala I. Awareness and knowledge on causes and impacts of climate change were low. A majority of the respondents perceived the will of God as being responsible to climate change causes and impacts on water resources quality in the study area. There is an urgent need for education of inhabitants on causes and impacts of climate change variables that are implicated on water source quality. Keywords: Perception and awareness, global warming, rainfall variability, sea level rise hazards,   Douala-Cameroo

Development of acid lactase milk

Call number: LD2668 .T4 ASI 1989 F66Master of ScienceAnimal Sciences and Industr

Gold compounds with anti-HIV and immunomodulatory activity

The human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) that subsequently develops remain major health concerns even after three decades since the first cases were reported. Successful therapeutic measures to address HIV/AIDS consist mostly of combinations of drugs targeting viral enzymes including reverse transcriptase (RT), protease (PR) and integrase (IN) as well as entry steps of the viral life cycle. The remarkable benefits (e.g. improved quality of life) derived from the use of these agents are unfortunately limited by toxicity to the host and the development of drug resistant viral strains. Drug resistance limits the repertoire of drug combinations available. Unfortunately, because latent forms of the virus exists, therapy has to be life-long and with new infections occurring every day, resistant strains tend to spread. To circumvent these problems, new drugs that inhibit resistant strains or work against new viral targets have to be developed. The history of gold compounds as potential inhibitors of HIV prompted this study in which twenty seven compounds consisting of gold(I), gold(III) and precursors from five classes were tested for drug-likeness, anti-HIV and immunomodulatory effects using wet lab and in silico methodologies. Cytotoxicity determination was done using viability dyes and flow cytometry. Cell proliferation profiles were monitored using the carboxyflourescein succinimidyl ester dye dilution technology and a real time cell analyser for confirming viability dye findings. The compounds’ effects on viral enzymes was determined using direct enzyme assays and in silico molecular modelling techniques. H and P nuclear magnetic resonance spectroscopy studies for determining stability revealed that the backbone chemical shifts of the compounds were relatively unchanged after one week (-20 and 37 ºC) when dissolved in dimethylsulfoxide. Eight of the gold compounds had drug-like properties comparable to clinically available drugs when in silico predictions were performed. The 50% cytotoxic dose of the compounds in human cells was between 1 and 20 μM (clinically relevant concentrations for gold compounds). Three gold(I) compounds inhibited viral infectivity at non-toxic concentrations and two gold(III) compounds did so at cytostatic (anti-proliferative mechanism that is also antiviral) concentrations. In the immunomodulatory assay, cytokine levels were altered by five compounds with one gold(I) and a gold(III) compound significantly reducing the frequency of CD4+ cells (an anti-viral function) from HIV+ donors (p= 0.005 and 0.027 respectively) when multi-parametric flow cytometry was performed. Inhibition of RT activity was predicted in in silico studies to be through interactions with the ribonuclease (RNase) H site although with poor stereochemical orientation while favourable binding predictions with the IN cofactor binding site were observed for some gold(III) complexes. Compounds predicted to interact with the RNase H site of RT and the IN cofactor site require structural modification to improve drug-likeness and binding affinity. The drug-like compound(s) which inhibited viral infectivity and lowered CD4+ cell frequency have potential for incorporation into virostatic cocktails (combination of cytostatic and directly anti-viral agent). Cytostatic agents are known to be less prone to drug resistance and because they lower CD4+ cell frequency, such compounds can potentially limit HIV immune activation.Thesis (PhD)--University of Pretoria, 2011.Biochemistryunrestricte

The aggressive nature of some urban springs in Dschang and suggested corrections prior to distribution

Many sections of Dschang town do not have pipe-borne water. For domestic purposes, about 25% of households cover distances of between 500 and 1000 meters to fetch water. The aim of this study is to see the possibility to bring the spring water closer to consumers. Analysis of the water is necessary before such a venture. The physicochemical analysis of spring waters consumed revealed their softness, their low level of mineralization and their aggressive character. Previous study indicated that Escherichia coli was present in those springs with variations from one spring to another. Considering the physicochemical and biological aspects of springs, the study proposed that the water be treated with calcium carbonate in order to improve upon the total hardness, total alkalinity and to bring water to the calco-carbonic equilibrium. To disinfect the water, calcium hypochlorite was recommended as well as polyvinyl chloride for the mini distribution network. Keywords: Langelier Index, calcium carbonate softness, remineralization, calco-carbonic equilibrium, network. International Journal of Biological and Chemical Sciences Vol. 2 (2) 2008: pp. 146-15

Effects of milk preservation using the lactoperoxidase system on processed yoghurt and cheese quality

The lactoperoxidase system (LP-system) is an acceptable chemical method for raw milk preservation, especially in rural areas where refrigeration facilities are absent to farmers. Milk production in most African countries is dominated by small-scale traditional production systems using low yielding local breeds. Therefore, processors who operate in such situations must rely on small volumes of milk from many farmers. Application of the LP-system prolongs the shelf life of raw milk and also encourages grouping of farmers hence facilitating milk collection by processors. The application of the LP-system is a recent preservation method for milk in Cameroon whose efficiency has been proven. Therefore, need arose for further studies on the influence of this method on milk processing as well as the quality dairy products. The LP-system was activated by adding 10 ppm sodium thiocyanate and 8.5 ppm sodium percarbonate to fresh milk. Yoghurt and Bambui cheese were processed separately from treated and untreated (control) milk samples. Yogurt was produced from both the treated and the control milk samples at 2%, 3%, 4% and 5% (v/v) culture levels. Yogurt samples were analysed for acidity, protein content and dry matter content while cheese was analysed for butterfat and moisture content. Statistical tests were conducted by Analysis of Variance using the Fisher's test. Simple organoleptic assessments were conducted to compare yogurt and cheese from the treated and the control milk. Activation of the LP-system delayed lactic acid formation in yogurt during incubation and storage leading to increased energy consumption during processing and an improved keeping quality during storage. LPsystem treatment reduced the overall organoleptic quality of yogurt while it improved on that of Bambui cheese. Dry matter content and fat content of yogurt were not significantly affected by LP-system treatment (