George E. Shambaugh

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The cyclin dependent kinase holoenzymes (CDKs), composed of catalytic (cdk) and regulatory (cyclin) subunits, promote cellular proliferation and are inhibited by cyclin dependent kinase inhibitor proteins (CDKIs). The CDKIs include the Ink4 family (p15Ink4b, p16Ink4a, p18Ink4c, p19Ink4d) and the KIP family (p21Cip1 and p27Kip1). The sustained induction of(More)
The urea cycle consist of five enzymatically controlled steps that are catalyzed by carbamyl phosphate synthetase, ornithine transcarbamylase, argininosuccinate synthetase, argininosuccinase, and arginase, respectively. The complete cycle is present in physiological meaningful levels in the liver of terrestrial vertebrates, and in man represents the sole(More)
The availability and utilization of B-hydroxybutyrate as an alternate oxidative fuel during fasting hypoglycemia has been examined in the rat conceptus at 18 and 20 days gestation. A 48-hr maternal fast between days 16 and 18 or 18 and 20 resulted in a 50% fall in fetal glucose levels and a marked rise in B-hydroxybutyrate, i.e., 30-fold at 18 and 60-fold(More)
Experiments with both humans and chinchillas indicate that the temporary threshold shift after ten-minute stimulation with 100 dB sound pressure level 1 kHz tone diminished more quickly if the subject breathed pure oxygen and it diminished even more quickly when 95% oxygen-5% carbon dioxide was inhaled rather than ambient air. This effect was observed for(More)
Human subjects and chinchilla breathed either Carbogen or compressed air prior to high level sound stimulation. Following stimulation, threshold shifts and recovery to prestimulation thresholds were monitored. Behavioral audiometry was used for human subjects and electrocochleography was utilized to measure noise-induced threshold shifts in the animals.(More)
The impact of maternal starvation during Days 17-20 of gestation was examined in 20-day fetal rat brain tissue cultured for 6 days in MEM and 10% adult rat serum. Acetylcholinesterase (AChE) activities were consistently greater in fetal brain cell cultures from starved mothers. When fetal tissues from starved mothers were continuously exposed to 72-h fasted(More)