Medicine and Health Sciences Commons^™

Waddington’S Widget: Hsp90 And The Inheritance Of Acquired Characters, Douglas M. Ruden, Mark D. Garfinkel, Vincent E. Sollars, Xiangyi Lu

Biochemistry and Microbiology

Conrad Waddington published an influential model for evolution in his 1942 paper, Canalization of Development and Inheritance of Acquired Characters. In this classic, albeit controversial, paper, he proposed that an unknown mechanism exists that conceals phenotypic variation until the organism is stressed. Recent studies have proposed that the highly conserved chaperone Hsp90 could function as a “capacitor,” or an “adaptively inducible canalizer,” that masks silent phenotypic variation of either genetic or epigenetic origin. This review will discuss evidence for, and arguments against, the role of Hsp90 as a capacitor for morphological evolution, and as a key component of what …

High Dietary Level Of Synthetic Vitamin E On Lipid Peroxidation, Membrane Fatty Acid Composition And Cytotoxicity In Breast Cancer Xenograft And In Mouse Host Tissue, Ivan L. Cameron, Jesus Munoz, Christopher J. Barnes, W. Elaine Hardman

Biochemistry and Microbiology

Background

d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE) is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE). This provided an intake of about 200 mg/kg body weight per day. The mice …

The Characterization Of Two Differentially Expressed Plasma Proteins In Obese Versus Lean Rats In Two Rodent Models Of Obesity, Roger D. Boggs

Theses, Dissertations and Capstones

Zucker fa and La/N faf rats are widely studied models of genetic obesity and its complications. These two rodent models of obesity were utilized to search for a circulating protein marker for obesity. Plasma samples from both of these models of obesity were collected and analyzed via SDS-PAGE analysis. Two proteins were found which demonstrate differential expression between lean and obese rats. Both proteins demonstrated increased expression in the obese rats compared to the lean. One differentially expressed protein migrated on SDS-PAGE gels at 116 KD while the second migrated at 22 KD compared to molecular weight markers. The 22 …

A Mechanistic Study In The Nephrotoxicity Of P-Aminophenol, R. Christopher Harmon

Theses, Dissertations and Capstones

The acetaminophen metabolite, p-aminophenol (PAP), is a known nephrotoxicant. The current study is directed at understanding the mechanism of this nephrotoxicity. Renal cortical slices isolated from F344 rats were incubated with 0 – 0.5 mM PAP with or without pretreatments. Renal slices exposed to PAP showed toxicity as measured by increased lactate dehydrogenase leakage (LDH), decreased pyruvate-stimulated gluconeogenesis, and decreased total adenine nucleotides. There was, however, an increase in ATP as percent of total, implying maintained mitochondrial function. These data show that PAP is directly toxic to renal cortical slices. Pretreatment with EDTA or EGTA provided protection from PAP- induced …