Failure of -carnitine to protect mice against ammonia toxicity

Recent reports indicate that intraperitoneal administration of -carnitine protects mice from ammonia toxicity. We found that mice injected with -carnitine and subsequently challenged with ammonium acetate succumb as readily as mice injected with saline and the ammonium acetate. Mice pretreated with -carnitine exhibited higher levels of liver ammonia than the saline-pretreated control mice. The ammonia and urea levels in serum and brains were similar in two groups. Our findings are in contrast to those reported previously and therefore warrants further investigation before -carnitine can be considered as a drug to alleviate hyperammonemia in humans.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27412/1/0000446.pd

Ornithine carbamyl transferase in Reye's syndrome

Serum levels of ornithine carbamyl transferase activities were determined in the acutely ill and convalescent Reye's syndrome patients and in their parents. Acutely ill Reye's syndrome patients had elevated levels of serum ornithine carbamyl transferase activities as compared to those in controls. The convalescent Reye's syndrome patients and their parents had normal levels of serum ornithine carbamyl transferase activities. These results suggest that an inborn metabolic defect was not responsible for the increase in serum ornithine carbamyl transferase activities in Reye's syndrome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24619/1/0000029.pd

Free fatty acids in an animal model of reye's syndrome

Recent studies have indicated that viral infections, aspirin treatment and hyperammonemia are associated with Reye's syndrome. It has also been reported that free fatty acids in serum and total lipids in the liver of Reye's syndrome patients are elevated during illness. The role of the lipid changes in the development of the disorder cannot be optimally studied in human patients, because infection and aspirin ingestion occur prior to the earliest symptoms of Reye's syndrome. Effects of influenza B infection, aspirin treatment and hyperammonemia on the level of free fatty acids, total lipids and triacylglycerols in serum and liver of an animal model of Reye's syndrome are reported here. Hyperammonemia was produced in young, male ferrets either by feeding them small amounts of an arginine-deficient diet after overnight fasting or by an intraperitoneal injection of jackbean urease. The ferret model resembled Reye's syndrome in developing increased levels of individual and total serum free fatty acids, liver triacylglycerol and total lipids. The results also indicate that influenza infection or aspirin treatment, or both, while increasing the severity of encephalopathy in the deficient ferrets, did not cause a significant change in the level of serum free fatty acids. Other results suggest that elevation of serum ammonia, serum free fatty acid or liver lipids, either singly or in various combinations, does not provide conditions that can explain the rapidly developing encephalopathy in the arginine-deficient ferrets.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25111/1/0000543.pd

Serum isocitrate dehydrogenase activity in Reye's syndrome

Serum levels of isocitrate dehydrogenase was determined in 12 Reye's syndrome patients and the enzyme levels were compared with serum ornithine carbamyl phosphate, glutamic oxaloacetic transaminase (aspartate aminotransferase), ammonia, and the stages of the disorder. Isocitrate dehydrogenase was elevated in 8 of the 12 patients and there was no direct correlation between elevated serum isocitrate dehydrogenase level and other clinical parameters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26752/1/0000304.pd

Statistical evaluation of nutritional components impacting phycocyanin production in Synechocystis SP

Alkaliphilic cyanobacterial cultures were isolated from Lonar lake (MS, India). Among the set of cultures, Synechocystis sp, was studied for phycocyanin production. A maximum yield was obtained in BG-11 medium at optimized conditions (pH 10 and 16 h light). In order to increase the phycocyanin yield media optimization based on the eight media components a Plackett-Burman design of the 12 experimental trials was used. As per the analysis CaCl2.2H2O and Na2CO3 have been found to be the most influencing media components at 95% significance. Further the optimum concentrations of these components were estimated following a Box Wilson Central Composite Design (CCD) with four star points and five replicates at the center points for each of two factors was adopted for optimization of these two media components. The results indicated that there was an interlinked influence of CaCl2.2H2O and Na2CO3 on 98% significance. The maximum yield of phycocyanin (12% of dry wt) could be obtained at 0.058 g/l and 0.115 g/l of CaCl2.2H2O and Na2CO3, respectively

Ultrastructural changes in hepatocytes of a potential animal model of Reye's syndrome

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24551/1/0000831.pd

Agroecological transformation for sustainable food systems : Insight on France-CGIAR research

This 26th dossier d’Agropolis is devoted to research and partnerships in agroecology. The French Commission for International Agricultural Research (CRAI) and Agropolis International, on behalf of CIRAD, INRAE and IRD and in partnership with CGIAR, has produced this new issue in the ‘Les dossiers d’Agropolis international’ series devoted to agroecology. This publication has been produced within the framework of the Action Plan signed by CGIAR and the French government on February 4th 2021 to strengthen French collaboration with CGIAR, where agroecology is highlighted as one of the three key priorities (alongside climate change, nutrition and food systems)