Biomedical subjects

J M Connors

Publications and source records attributed to J M Connors.

130 records · Page 8Linked to original sources

PubMed1975

Altitude-induced erythrocytic 2,3-DPG and hemoglobin changes in rats of various ages.

Rats of various ages (2, 12, 24, and 40 mo of age) were exposed for 4 wk to either a simulated high altitude of 23,000 ft or to a Peoria, Ill., altitude of 650 ft above sea level. Hematocrit ratios, hemoglobin, and erythrocytic 2,3-diphospho-glycerate (2,3-DPG) concentrations were measured. Hematocrit and hemoglobin determinations revealed a decrease in erythrocytic content with increasing age, and the augmented erythropoietic response was seen in all age groups of animals as a result of altitude exposure. The maximal erythrocytic content of hemoglobin in the 40-mo-old animals was significantly lower than that of all other age groups. Erythrocytic 2,3-DPG levels were significantly changed by aging alone. In the 40-mo-old group there was a 35% increase over the next highest sea-level value. However, while erythrocytic 2,3-DPG content increased significantly in all other age groups following altitude exposure, it decreased 46% in the 40-mo-old group.

Aging↗

PubMed1975

Effect of aging on right ventricular anoxic resistance.

Total serum thyroxine levels, saturation of endogenous thyroxine-binding proteins, and free thyroxine indices were all reduced in the rat by aging. In vitro myocardial anoxic resistance was increased as a result of the aging process. The role of myocardial glycogen as a myocardial protective agent during hypoxic stress and its variations during aging, altitude-acclimation, and exericise conditioning are discussed.

Aging↗

PubMedDate not supplied

Hematologic and immunologic changes in hairy cell leukemia patients treated with alpha interferon.

We prospectively evaluated hematologic and immunologic changes in fourteen hairy cell leukemia patients treated with alpha interferon. Prompt disappearance of circulating hairy cells, and recovery of peripheral blood counts was observed in all patients whereas only four patients had complete disappearance of hairy cell infiltrates from their bone marrow. Immunologic changes included a statistically significant increase of NK cell activity in the whole group and a slight decrease in circulating T cells with a strong trend towards an increase in the T4/T8 lymphocyte ratio (in eight of fourteen patients). Serial hemopoietic progenitor cell culture studies from peripheral blood (thirteen patients) and bone marrow (two patients) showed no correlation between hematologic recovery data and cell culture data.

Adult↗

PubMedDate not supplied

Prospectively randomized toxicity study of high-dose versus low-dose treatment strategies for lymphoblastoid interferon.

It is unclear from preliminary laboratory studies whether a high- or a low-dose interferon treatment strategy is optimal. As part of an ongoing study of mechanisms of interferon action, we have evaluated toxicity in a two-arm protocol in which patients were randomly assigned to receive lymphoblastoid interferon by either a low-dose treatment strategy (2 X 10(6) units/m2 daily X 28 days then daily X 5 days every other week by im injection) or a high-dose treatment strategy (5 X 10(6) units/m2 by continuous iv infusion over 24 hours, escalating by 5 X 10(6) units/m2/day as tolerated over 10 days, repeated every 28 days). The main toxic effects in both arms were fever, fatigue, and anorexia. Marked interpatient differences within each dose arm were greater than differences between arms. Additional significant toxic effects included nausea and vomiting, hypotension, leukopenia, thrombocytopenia, and evidence of hepatic toxicity. Minor changes in serum electrolytes were noted. Coagulation studies were normal. The dose-limiting toxic effect for the high-dose arm was myelosuppression. Median maximum tolerated dose among high-dose strategy patients was 18 X 10(6) units/m2, but there was marked interpatient variation. We conclude that both dose schedules were relatively well-tolerated. Because of individual variation in tolerance, high-dose treatment should include a dose escalation strategy.

Adult↗