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Background: Glycerol is a substrate for gluconeogenesis and fatty acid esterification in the liver, processes which are upregulated in obesity and may contribute to excess fat accumulation. Glycine and glutamate, in addition to cysteine, are components of glutathione, the major antioxidant in the liver. In principle, glycerol could be incorporated into glutathione via the TCA cycle or 3-phosphoglycerate, but it is unknown whether glycerol contributes to hepatic de novo glutathione biosynthesis. Methods: Glycerol metabolism to hepatic metabolic products including glutathione was examined in the liver from adolescents undergoing bariatric surgery. Participants received oral [U–13C3]glycerol (50 mg/kg) prior to surgery and liver tissue (0.2–0.7g) was obtained during surgery. Glutathione, amino acids, and other water-soluble metabolites were extracted from the liver tissue and isotopomers were quantified with nuclear magnetic resonance spectroscopy. Results: Data were collected from 8 participants (2 male, 6 female; age 17.1 years [range 14–19]; BMI 47.4 kg/m2 [range 41.3–63.3]). The concentrations of free glutamate, cysteine, and glycine were similar among participants, and so were the fractions of 13C-labeled glutamate and glycine derived from [U–13C3]glycerol. The signals from all component amino acids of glutathione - glutamate, cysteine and glycine - were strong and analyzed to obtain the relative concentrations of the antioxidant in the liver. The signals from glutathione containing [13C2]glycine or [13C2]glutamate derived from the [U–13C3]glycerol drink were readily detected, and 13C-labelling patterns in the moieties were consistent with the patterns in corresponding free amino acids from the de novo glutathione synthesis pathway. The newly synthesized glutathione with [U–13C3]glycerol trended to be lower in obese adolescents with liver pathology. Conclusions: This is the first report of glycerol incorporation into glutathione through glycine or glutamate metabolism in human liver. This could represent a compensatory mechanism to increase glutathione in the setting of excess glycerol delivery to the liver.

Abstract E‐learning strategies have become an important part of biomedical education. However, why and how medical students select hardware tools and software formats during their preclinical education has not been sufficiently evaluated. These aspects should be considered when designing or offering new e‐learning modalities to learners. Two medical school classes at a major US medical school were surveyed about their use of e‐learning resources during their first year of medical school or their preparation for their first licensing examination (USMLE® Step 1), respectively. Their responses were analyzed for patterns and significant changes. Students’ answers indicated that computers and tablets were considered the most important hardware devices to support students’ learning. During the first year, students often preferred resources that were tailored to the specific courses in their curriculum. In contrast, some preferences changed when students prepared for the USMLE Step 1, with students shifting almost exclusively to a solitary learning strategy using commercial e‐learning resources. Across all phases of medical school education queried, peer advice was the major determinant influencing e‐learning resource selection with faculty only playing a minor role. Videos were the most popular e‐learning modality, and students cited efficient acquisition of knowledge and preparation for examinations as major reasons for e‐learning tool utilization. These factors should be considered when offering e‐learning resources to medical students during different phases of their preclinical training.

This document is ENY-825, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: September 2002. https://edis.ifas.ufl.edu/in458

This document is ENY-825, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: September 2002. https://edis.ifas.ufl.edu/in458

This document is ENY-825, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: September 2002. https://edis.ifas.ufl.edu/in458