Roger Collins

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Two strains of Mus musculus musculus, C57BL/6J and CD-1, and Mus musculus poschiavinus, the tobacco mouse, were used to study the effects of increased gene dosage of mouse chromosome 16 (MMU 16). A developmental delay has been found in the brains of murine trisomy 16 (Ts16) fetuses. Both the brain weight (in all three strains) and DNA content (in CD-1) were(More)
Maple syrup urine disease (MSUD) and phenylketonuria (PKU) are associated with accumulation of large neutral amino acids (LNAA) in blood and tissues and a decrease of other LNAA not directly related to the enzyme defects. One characteristic shared by both the elevated and decreased amino acids is that all are substrates for transport via the large neutral(More)
Leucine and α-ketoisocaproate (α-KIC) were perfused at increasing concentrations into rat brain hippocampus by microdialysis to mimic the conditions of maple syrup urine disease. The effects of elevated leucine or α-KIC on the oxidation of L-[U-14C]glutamate and L-[U-14C]glutamine in the brain were determined in the non-anesthetized rat. 14CO2 generated by(More)
Significantly lower concentrations of norepinephrine were observed in whole brain and hypothalamus of pups exposed to ethanol pre- and post-natally as compared to controls. Dopamine levels were found to be unaltered in whole brain compared to controls although hypothalamus and corpus striatum demonstrated a decreased concentration in the experimental(More)
African Americans account for about 12.7% of the United States population, but only 1% of the National Society of Genetic Counselors’ membership identifies as African American. Since individuals often seek health care from providers sharing similar backgrounds, training genetic counselors from diverse backgrounds is critical. Psychology and biology students(More)
It has been proposed that hyperammonemia may be associated with valproate therapy. As astrocytes are the primary site of ammonia detoxification in brain, the effects of valproate on glutamate and glutamine metabolism in astrocytes were studied. It is well established that, because of compartmentation of glutamine synthetase, astrocytes are the site of(More)
A retrospective survey of 147 patients with Down's syndrome (age range, 4 months to 27 years) showed that 60% had a thyrotropin (TSH) level higher than 5.7 mU/L in the presence of high or normal thyroxine levels. The remaining 40% of the group had low to normal TSH values. High TSH levels were predominant in patients under 4 years of age (94 children), ie,(More)
Metabolic compartmentation of amino acid metabolism in brain is exemplified by the differential synthesis of glutamate and glutamine from the identical precursor and by the localization of the enzyme glutamine synthetase in glial cells. In the current study, we determined if the oxidative metabolism of glutamate and glutamine was also compartmentalized. The(More)