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Biomedical subjects

R B Nelson

Publications and source records attributed to R B Nelson.

49 records · Page 3Linked to original sources

Selective decline in protein F1 phosphorylation in hippocampus of senescent rats.

Certain forms of neuronal plasticity have been found to be expressed through alterations in brain protein phosphorylation, and its regulation by protein kinase activity. Of interest in this regard is the possibility that the decline in neuronal plasticity and cognitive function that occurs in advanced age may result in part from altered phosphorylation of specific proteins. As a first attempt to identify age-related changes in phosphoproteins, we assayed in vitro phosphorylation of proteins in hippocampus, cerebellum, entorhinal cortex, and frontal cortex from Fischer-344 rats of 5 months, 11 months, and 25 months of age. Compared to the middle-aged animals, the aged rats showed a selective 46% decline in phosphorylation of the 47 kDa protein (F1) in hippocampus, with no change in the phosphorylation of other proteins measured in this structure. Aged animals also showed decreased phosphorylation relative to young animals. No age-related change was observed in any protein band for the other brain areas examined. Since protein F1 is phosphorylated by protein kinase C (PKC), the cytosolic and membrane distribution of this enzyme was compared across age groups. The activity of PKC in hippocampus did not change across age. The explanation of this age-related decline in protein F1 phosphorylation is likely to be a decline in the substrate protein itself. The results are discussed in terms of protein F1's possible role in age-related decline of hippocampal synaptic plasticity.

Aging↗

Immediate versus postponed combination chemotherapy (CAMP) for unresectable non-small cell lung cancer: a randomized trial.

A randomized control trial was performed in good performance status patients with unresectable non-small cell lung cancer to test a strategy of early aggressive combination chemotherapy (CAMP [cyclophosphamide, doxorubicin, methotrexate, and procarbazine]) versus a strategy of delaying such treatment until clinical deterioration. Thirty-seven patients received immediate CAMP and 35 patients received initial low-dose single-agent CCNU (CAMP was postponed). Immediate CAMP therapy produced an objective response rate of 44% in patients with measurable lesions, and CCNU produced none. Median survival was 193 days for the immediate-CAMP group and 175 days for the postponed-CAMP group (P = 0.26). Measures of quality of life were made and no difference emerged between the two treatment strategies. This trial failed to show substantial benefit from immediate combination chemotherapy in minimally symptomatic patients with non-small cell lung cancer.

Antineoplastic Agents↗