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Biomedical subjects

T Buckman

Publications and source records attributed to T Buckman.

9 recordsLinked to original sources

In vitro comparison of equine granulocytes labeled with 99mTc-hexamethylpropyleneamine oxime or 111In-oxine.

Isolated equine granulocytes (WBC), radiolabeled with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) or 111In-oxine, were evaluated in vitro for their labeling characteristics, viability, and phagocytic function over a 6-hour postlabeling period. Mean +/- SD labeling efficiency for 111In-oxine-WBC was 62.2 +/- 15.3%, which was significantly (P less than 0.001) higher than that for 99mTc-HMPAO-WBC (32.0 +/- 17.0%). In vitro elution of radiolabel from cells was significantly (P less than 0.02) greater for 99mTc-HMPAO-WBC at 0.5, 2, and 4 hours, but was not significantly different from elution of radiolabel for 111In-oxine-WBC at 6 hours. Viability, assessed by trypan blue dye exclusion, for 99mTc-HMPAO-WBC, 111In-oxine-WBC, and nonlabeled control WBC ranged from 97 to 100%, and was not significantly different among groups. Cell function was assessed by use of a phagocytosis assay and was reported as phagocytic index. The phagocytic index ranged from 0.86 to 0.96 for 99mTc-HMPAO-WBC, and from 0.76 to 0.97 for 111In-oxine-WBC. The phagocytic index was not significantly different at 0.5, 2, or 4 hours, but was significantly (P = 0.038) greater at 6 hours for 99mTc-HMPAO-WBC. Because of the superior imaging characteristics of 99mTc-HMPAO-WBC and equal or better labeling characteristics than those for 111In-oxine at 6 hours, 99mTc-HMPAO-WBC appear to be a good alternative to 111In-oxine-WBC.

Animals

Effect of adrenaline, fentanyl and warming of injectate on shivering following extradural analgesia in labour.

This prospective, controlled study was undertaken to determine whether addition of adrenaline or fentanyl to bupivacaine or warming of the injectate had any effect on the incidence of shivering following extradural analgesia in the labouring parturient. Eighty-four patients were sequentially allocated to four groups (control, warm injectate, extradural adrenaline and extradural fentanyl). The adrenaline group had the highest incidence of shivering, the warm injectate and fentanyl groups the lowest. Extradural fentanyl also seemed promising in reducing shivering in pre-block shiverers. This paper also explores the rapidity of temperature decay of solutions of bupivacaine in different clinical situations.

Adult

Alterations in lipid acyl group composition and membrane structure in cells transformed by Rous sarcoma virus.

The acyl group composition of the phospholipids from normal chick embryo fibroblasts and from cells transformed by Rous sarcoma virus was determined by gas-liquid chromatography. Rous-transformed cells had less arachidonate (20:4) and more oleate (18:1) in membrane lipids than normal, growing cells. Normal density-inhibited cells had the lowest ratio of 18:1/20:4. Associated with the decreased content of 20:4 in the transformed cells was a decreased motional freedom of an incorporated spin-labeled fatty acid analogue. Arrhenius plots for uptake of 2-deoxyglucose revealed an increased apparent activation energy in the transformed cells, suggesting that the hexose transport carriers were sensitive to the changes in membrane composition and structure in fully transformed cells. However, the development of the changes in fatty acid composition occurred relatively slowly in the course of transformation, indicating that the observed compositional alterations are not likely to be a primary cause of the early changes in membrane function associated with malignant transformation.

Animals

Transport changes associated with growth control and malignant transformation.

We can distinguish two classes of membrane transport changes in cultured cells: (a) growth-rate contingent changes are those which occur in coordination with the onset of density-dependent inhibition of growth; (b) transformation-specific changes are those which occur when cells become transformed, and which can be detected even when normal and transformed cells are growing at the same rate. Growth-rate contingent changes include the density-dependent changes in phosphate, nucleoside, glucose, amino acid, and potassium transport. Only one transformation-specific transport change has been found in Rous-transformed chicken embryo fibroblasts: an increased rate of hexose transport. The variation in potassium transport are associated with variations in the number of ouabain binding sites in the membrane. The molecular basis for changes in the rate of hexose transport is unknown, although gross changes in membrane bilayer composition and "fluidity" seem not to be involved. In analyzing the regulation of hexose transport activity, we find that decreased cAMP may play a role in the transformation-specific increase in hexose transport, but that fibrinolytic activity is not necessary.

Aminobutyrates