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Kevin Peterson

Publications and source records attributed to Kevin Peterson.

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Cephalopod vision involves dicarboxylic amino acids: D-aspartate, L-aspartate and L-glutamate.

In the present study, we report the finding of high concentrations of D-Asp (D-aspartate) in the retina of the cephalopods Sepia officinalis, Loligo vulgaris and Octopus vulgaris. D-Asp increases in concentration in the retina and optic lobes as the animal develops. In neonatal S. officinalis, the concentration of D-Asp in the retina is 1.8+/-0.2 micromol/g of tissue, and in the optic lobes it is 5.5+/-0.4 micromol/g of tissue. In adult animals, D-Asp is found at a concentration of 3.5+/-0.4 micromol/g in retina and 16.2+/-1.5 micromol/g in optic lobes (1.9-fold increased in the retina, and 2.9-fold increased in the optic lobes). In the retina and optic lobes of S. officinalis, the concentration of D-Asp, L-Asp (L-aspartate) and L-Glu (L-glutamate) is significantly influenced by the light/dark environment. In adult animals left in the dark, these three amino acids fall significantly in concentration in both retina (approx. 25% less) and optic lobes (approx. 20% less) compared with the control animals (animals left in a diurnal/nocturnal physiological cycle). The reduction in concentration is in all cases statistically significant (P=0.01-0.05). Experiments conducted in S. officinalis by using D-[2,3-3H]Asp have shown that D-Asp is synthesized in the optic lobes and is then transported actively into the retina. D-aspartate racemase, an enzyme which converts L-Asp into D-Asp, is also present in these tissues, and it is significantly decreased in concentration in animals left for 5 days in the dark compared with control animals. Our hypothesis is that the dicarboxylic amino acids, D-Asp, L-Asp and L-Glu, play important roles in vision.

Amino Acid Isomerases↗

Reducing cardiovascular disease risk in patients with type 2 diabetes: a message from the National Diabetes Education Program.

Cardiovascular disease is responsible for 65 percent of deaths in persons with type 2 diabetes. However, awareness of cardiovascular disease risk factors among patients with diabetes remains low, resulting in missed opportunities to lower risks for coronary events and strokes. The National Diabetes Education Program has begun a campaign to increase patient participation in risk-reduction practice s by promoting the "ABCs" of diabetes care: A(1c) level, Blood pressure, and Cholesterol level. By increasing patient awareness of the link between diabetes and heart disease, family physicians can encourage patients to take medications (including aspirin), stop smoking, lower blood pressure, and lower cholesterol and blood glucose levels.

Cardiovascular Diseases↗