Search PubMed⌕ Search

Biomedical subjects

S B Harper

Publications and source records attributed to S B Harper.

3 recordsLinked to original sources
PubMed1994

Use of capillary electrophoresis-isoelectric focusing for the determination of bovine hemoglobin variants.

A capillary electrophoretic technique was developed to monitor patterns of hemoglobin production in young calves subjected to multiple phlebotomies. The method is similar to one previously described for the determination of human hemoglobin variants in whole blood using isoelectric focusing. After a single collection of one-half the circulating blood volume, there were obvious alterations in hemoglobin chain variants. HbA levels diminished as blood loss increased with minimum values corresponding to maximum blood loss. HbF levels did not appear to be affected. Also visible during the regenerative process were atypical overlapping peaks preceding the normal hemoglobin peaks. At the conclusion of the 18-day study, most of the electropherograms had returned to initial states. These changes were found to be a sensitive indicator of accelerated erythropoiesis in contrast to the standard technique of total hemoglobin determination by colorimetric means.

Animals↗
PubMedDate not supplied

The response of various hematologic parameters in the young bovine subjected to multiple phlebotomies.

Specific guidelines for the optimal collection of blood from calves maintained as donors do not exist. This investigation was conducted to document erythrocytic changes in calves subjected to controlled blood loss. Two groups of Holstein calves ranging in age from 2 to 5 months were compared. Six animals were designated controls and six were subjected to a series of three blood collections over an 8 day period. Each collection was roughly 50% of the total circulating blood volume (30 ml/kg of body weight). Hematologic values were compared for 18 days. All calves survived the study. There was no significant difference in circulating cortisol levels or growth rate between groups. Packed cell volumes (PCVs) for the phlebotomized group did not return to original levels during the monitoring period (initial 36%, final 26%), but were within normal limits at 30 days. All phlebotomized calves had a high reticulocyte count (0% control, 11% phlebotomized). Reticulocytes were not observed until the PCV fell below 20. HbF to HbA ratios were a sensitive and acute indicator of accelerated erythropoiesis. Variant ratios stabilized within 18 days. Other parameters compared were red cell indices, total erythrocyte count, total leukocyte count, total plasma protein, total hemoglobin values, and neutrophil to lymphocyte ratios.

Age Factors↗