Early Hypothalamic FTO Overexpression in Response to Maternal Obesity – Potential Contribution to Postweaning Hyperphagia

Intrauterine and postnatal overnutrition program hyperphagia, adiposity and glucose intolerance in offspring. Single-nucleotide polymorphisms (SNPs) of the fat mass and obesity associated (FTO) gene have been linked to increased risk of obesity. FTO is highly expressed in hypothalamic regions critical for energy balance and hyperphagic phenotypes were linked with FTO SNPs. As nutrition during fetal development can influence the expression of genes involved in metabolic function, we investigated the impact of maternal obesity on FTO.Female Sprague Dawley rats were exposed to chow or high fat diet (HFD) for 5 weeks before mating, throughout gestation and lactation. On postnatal day 1 (PND1), some litters were adjusted to 3 pups (vs. 12 control) to induce postnatal overnutrition. At PND20, rats were weaned onto chow or HFD for 15 weeks. FTO mRNA expression in the hypothalamus and liver, as well as hepatic markers of lipid metabolism were measured.At weaning, hypothalamic FTO mRNA expression was increased significantly in offspring of obese mothers and FTO was correlated with both visceral and epididymal fat mass (P<0.05); body weight approached significance (P = 0.07). Hepatic FTO and Fatty Acid Synthase mRNA expression were decreased by maternal obesity. At 18 weeks, FTO mRNA expression did not differ between groups; however body weight was significantly correlated with hypothalamic FTO. Postnatal HFD feeding significantly reduced hepatic Carnitine Palmitoyltransferase-1a but did not affect the expression of other hepatic markers investigated. FTO was not affected by chronic HFD feeding.Maternal obesity significantly impacted FTO expression in both hypothalamus and liver at weaning. Early overexpression of hypothalamic FTO correlated with increased adiposity and later food intake of siblings exposed to HFD suggesting upregulation of FTO may contribute to subsequent hyperphagia, in line with some human data. No effect of maternal obesity was observed on FTO in adulthood

Influence of nutrient concentrations on the seasonal abundance and distribution of Cyanophyceae in the coastal region of Mount Cameroon

Water management in the coastal region of Mount Cameroon is threatened by extensive and persistent noxious blooms of Cyanophyceae (blue-green algae) in the surface and near-surface mesotrophic and eutrophic zones. Nutrient concentrations and species composition of Cyanophyceae were investigated from surface waters at 15 stations from three sites along the Mount Cameroon region (Mudeka Creek, Tito Creek and Idenau Beach) during the rainy season, from July to August 1999, and during the dry season, from February to March 2000. Nitrate concentrations were extremely high during the rainy season, ranging from 240.07mg l–1 to 927.07mg l–1, and comparatively low, ranging from 1.79mg l–1 to 10.39mg l–1, during the dry season The Cyanophyceae community consisted of six genera: Microcystis, Lyngbya, Gloeocapsa, Trichodesmium, Chamaesiphon and Aphanocapsa. Three species (T. dispersa, T. lacustre and L. birgei) were present during the rainy season whereas five species, with two dominant (M. aeruginosa, G. dispersa), were present during the dry season. There was a positive correlation (r = 0.73) between nutrient concentration and Cyanophyceae concentration. Water transparency depth (Secchi disc depth) was much shallower during the rainy season than during the dry season, most likely as a result of the increased leaching of insoluble material from the land and decay of Cyanophyceae blooms during the rainy season. Management strategies to limit the formation of algal blooms in the region are discussed.Keywords: algal bloom, blue-green algae, Cameroon coast, Cyanophyceae, nutrientsAfrican Journal of Marine Science 2006, 28(1): 25–3

Detailed analysis of the food of Sarotherodon melanotheron(RUPPELL) from an inland tropical lake, Ibadan,Nigeria

No Abstract

Preliminary study on the domestication of broodstock of an ornamental aquarium fish, Synodontis obesus (Teleostei: Mochokidae) in concrete tanks

The state of ornamental aquarium fish export trade in Cameroon is largely undeveloped. This is due mainly to lack of technical know-how concerning domestication and breeding. Synodontis obesus broodfish has been domesticated for six months in concrete tanks located at Buea, Cameroon using local food materials and plankton species, without fertilization. The broodfish were domesticated under temperatures ranging from 20.4-24°C, pH, (6.6-10.0); dissolved oxygen, (0.75-11.0mg/l) and electrical conductivity, (40.5-523 µS/cm) in the experimental concrete tanks. Dissolved oxygen concentration was enhanced using an air blower. The average rate of aeration was 3.6 hours per day using an automatic timing device. The results also revealed that the levels of dissolved oxygen concentration were higher between the hours of 1200 and 1700 (5.2-6.0mg/l) even without aeration. Primary productivity was considerably increased by the aeration of the tanks at 3.6 h day-1. Brood fish were fed a mixture of 375g of tapioca, 100g of crushed boiled cabbage and 150g of crushed dried crayfish. The broodstock of this ornamental aquarium fish species may not survive in concrete tanks without the right type and quantity of supplementary food. Keywords: ornamental, aquarium, experimental tanks, broodstock, Synodontis obesus, domestication Tropical Freshwater Biology 2003/2004 Vol. 12/13: 137-15

Effects of Replacing Fishmeal with Soyabean in Diets of Oreochromis Niloticus Fingerlings in Buea, Cameroon

Oreochromis niloticus fingerlings were fed four with isoproteic (30% crude protein) diets in which soya bean meal (SBM) partially or completely replaced fishmeal (FM), and the effect of the diets on the growth performance and nutrient utilization of the fingerlings was evaluated. 80 fingerlings of mean weight 5.594g were distributed among 8 transparent plastic tanks (10/tank) with two replicates per treatment and the trial lasted 56 days. The control (Diet I) had no replacement of FM with SBM while the experimental diets: Diet II, Diet III and Diet IV had 35%, 65% and 100% replacement respectively. There were significant differences in the mean total weight gain at P&lt;0.05, with fingerlings fed Diet III having the greatest mean total weight gain (3.695&#177;0.061 g) and those in Diet II, the least (0.930&#177;0.388g). The total percentage weight gain and the apparent protein efficiency ratio followed the same trend. Diet III was the most palatable diet with the greatest mean final feed intake value (1.853&#177;0.004g). Percentage digestibility and feed conversion efficiency values of diets also increased with increasing replacement of FM. The effective substitution of 65% fishmeal by soya bean without negative effects on fish condition has positive implications for increased fish production in Cameroon from aquaculture.Des alevins Oreochromis niloticus ont &#233;t&#233; nourris sur base de quatre r&#233;gimes isoprot&#233;iques (30% de prot&#233;ine brute) dans lesquels la farine de soja (FS) a partiellement ou totalement remplac&#233; la farine de poisson (FP) ; et l&#8217;effet de ces r&#233;gimes sur la croissance et l&#8217;utilisation des &#233;l&#233;ments nutritifs par les alevins a &#233;t&#233; &#233;valu&#233;. Quatre-vingt (80) alevins d&#8217;un poids moyen de 5,594g ont &#233;t&#233; r&#233;partis dans 8 cuves en plastique transparentes (10/cuve) avec deux r&#233;p&#233;titions par traitement, et l&#8217;essai a dur&#233; 56 jours. Dans le r&#233;gime t&#233;moin (r&#233;gime I), il n&#8217;a pas eu de remplacement de farine de poisson par la farine de soja, tandis que les r&#233;gimes exp&#233;rimentaux - r&#233;gimes II, III et IV ont respectivement eu des remplacements de 35%, 65% et 100%. On a not&#233; des diff&#233;rences significatives au niveau du gain pond&#233;ral total moyen &#224; P &lt;0,05, les alevins nourris au r&#233;gime III ayant le plus grand gain pond&#233;ral total moyen (3,695 &#177; 0,061 g) et ceux du r&#233;gime II ayant le plus faible gain pond&#233;ral total moyen (0,930 &#177; 0.388g). Le pourcentage total du gain pond&#233;ral et le coefficient d&#8217;efficacit&#233; prot&#233;ique apparente ont suivi la m&#234;me tendance. Le r&#233;gime III &#233;tait le plus agr&#233;able au go&#251;t, avec la plus grande valeur moyenne d&#8217;absorption alimentaire finale (1,853 &#177; 0.004g). Les valeurs de pourcentage, de digestibilit&#233; et d&#8217;efficacit&#233; de conversion des aliments des r&#233;gimes ont &#233;galement augment&#233; parall&#232;lement au remplacement croissant de la farine de poisson. La substitution efficace de 65% de la farine de poisson par la farine de soja, sans effets n&#233;gatifs sur l&#8217;&#233;tat des poissons, a des implications positives pour l&#8217;augmentation de la production de poissons au Cameroun.Mots-cl&#233;s: Farine de poisson; Farine de soja; R&#233;gimes; Oreochromis niloticus; Camerou

Occurrence and Deleterious Effects of Algal Blooms Associated With Some Pollutants in Three Man-Made Lakes

Associations of plankton genera, some of which are known to be potentially harmful and indicative of pollution stress in surface waters were studied alongside some of their corresponding physico-chemical parameters, in three man-made lakes (reservoirs) over a period of 18 months in Ibadan, Nigeria. These lakes receive sewage effluents and agricultural run-offs. Two of these, Lakes Awba and Main are sites of drinking water abstraction. Bloom-forming algal families found in association included members of the phytoplankton class Chlorophyceae: (Pediastrium spp and Spirogyra spp.), the Bacillariophyceae which included Synedra, Melosira and Nitzschia species and potentially toxin-producing genera of the class Cyanophyceae (Microcystis, Anabaena, Aphanizomenon and Lyngbya). The plankton exhibited significant correlations with pH, temperature, total suspended solids, dissolved oxygen, carbon dioxide, nitrate-nitrogen and ammonium-nitrogen at various seasons of the year. An altered physico-chemistry of large areas of the lake and a total absence of aquatic life in some highly polluted parts were recorded in the study. Reports from lake users were recorded, of contaminated bad tasting water unfit to drink, unpalatable fish and skin infections, all indicators of the far-reaching effects algae can have on fresh water supplies. This paper calls for more frequent and thorough monitoring of such resources Keywords: Sewage, Bloom–forming algae, pollution, water quality parameters, agricultural run-offs, eutrophic, harmful algal bloomsTropical Freshwater Biology Vol. 17 (1) 2008: pp. 53-7

Bacterial indicators of pollution of the Douala lagoon, Cameroon: Public health implications.

Background: Indiscriminate disposal of untreated wastes which are often heavily laden with sewage microorganisms some of which are pathogenic to humans into aquatic environments near cities could serve as potential dangers to human health. Objective: A prospective study was undertaken to investigate the scope of potential bacterial pathogens and to assess the extent of pollution of the Douala lagoon. Methods: A total of eighty water samples were collected fortnightly from the lagoon at five stations from March to October 2005 and analysed for heterotrophic bacterial densities, coliform counts, faecal coliform and faecal streptococcal counts. Bacteria were isolated and identified using standard microbiology and biochemical techniques. Results: High heterotrophic bacterial counts (33 × 105 –161 ×105 CFU/ mL), total coliform counts (1.8 ×102 - 2.4 ×102 CFU/ 100 mL), faecal coliform counts (2.2 × 102 – 2.4 × 102 CFU/ 100 mL) and faecal streptococcal counts (2.1 × 102 – 2.3 x 102 CFU/ 100 mL) were observed in all sampling stations. Eleven species of bacteria: Bacteroides fragilis, Proteus vulgaris, Klebsiella pneumoniae, E. coli, Enterococcus faecalis, Enterobacter aerogenes, Citrobacter freundii, Aeromonas hydrophila, Pseudomonas aeruginosa, Bacillus mycoides and Serratia marcesens, were frequently isolated. Conclusion: The presence of potential bacterial agents such as Bacteroides fragilis, Pseudomonas aeruginosa, Aeromonas hydrophila, Klebsiella pneumoniae and E. coli in the lagoon may pose a serious threat to the health and well being of users of the Lagoon and calls for urgent intervention. African Health Science Vol. 8 (2) 2008: pp. 85-8

Interaction between maternal and offspring diet to impair vascular function and oxidative balance in high fat fed male mice

Aims: to determine the impact of maternal and post-weaning consumption of a high fat diet on endothelium-dependent vasorelaxation and redox regulation in adult male mouse offspring.Methods: female C57BL6J mice were fed an obesogenic high fat diet (HF, 45% kcal fat) or standard chow (C, 21% kcal fat) pre-conception and throughout pregnancy and lactation. Post-weaning, male offspring were continued on the same diet as their mothers or placed on the alternative diet to give 4 dietary groups (C/C, HF/C, C/HF and HF/HF) which were studied at 15 or 30 weeks of age.Results: there were significant effects of maternal diet on offspring body weight (p&lt;0.004), systolic blood pressure (p = 0.026) and endothelium-dependent relaxation to ACh (p = 0.004) and NO production (p = 0.005) measured in the femoral artery. With control for maternal diet there was also an effect of offspring post-weaning dietary fat to increase systolic blood pressure (p&lt;0.0001) and reduce endothelium-dependent relaxation (p = 0.022) and ACh-mediated NO production (p = 0.007). There was also a significant impact of age (p&lt;0.005). Redox balance was perturbed, with altered regulation of vascular enzymes involved in ROS/NO signalling.Conclusions: maternal consumption of a HF diet is associated with changes in vascular function and oxidative balance in the offspring of similar magnitude to those seen with consumption of a high fat diet post-weaning. Further, this disadvantageous vascular phenotype is exacerbated by age to influence the risk of developing obesity, raised blood pressure and endothelial dysfunction in adult lif