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Biomedical subjects

B J Gaffney

Publications and source records attributed to B J Gaffney.

45 records · Page 3Linked to original sources
PubMed1980

Spin-label studies of erythrocytes in myotonic dystrophy: no increase in membrane fluidity.

The basic defect in myotonic dystrophy is thought to involve muscle cell membranes. Butterfield and associates have recently presented electron spin resonance data that suggest increased fluidity of erythrocyte membranes in patients with myotonic dystrophy. We studied erythrocytes from 11 patients with myotonic dystrophy and 14 age-matched controls, using spin-labeled fatty acid and ester probes. Despite attempts to reproduce the previously reported experimental conditions exactly, we found no significant differences in the electron spin resonance spectra of erythrocytes from normal and myotonic dystrophy subjects. These findings do not provide evidence of increased erythrocyte membrane fluidity in myotonic dystrophy; they fail to support the concept of an intrinsic defect of the lipid membrane in this disorder.

Adult↗
PubMed1980

Sick sinus syndrome: mechanisms and management.

Sick sinus syndrome has become a frequent and challenging diagnosis for the practicing physician (Fig. 6). Increased longevity will create even more patients in need of effective therapy. Multiple etiologies have been described, but the common final pathway in most instances appears to be chronic fibrosis of the sinus node. The multifaceted features of the syndrome have delayed an organized diagnostic approach until recently. Noninvasive diagnosis often suffices, particularly with the availability of Holter monitoring. Invasive studies help to confirm sinus node dysfunction and possible associated conduction defects in these patients. The prognosis is variable and at times unpredictable. Nonetheless, it is best to establish the diagnosis promptly and to institute appropriate therapy. Cardiac pacing has had a particularly beneficial impact on the long-term management of the sick sinus syndrome.

Cardiac Pacing, Artificial↗
PubMed1979

Complete exchange of viral cholesterol.

The exchange of the cholesterol in the membranes of two enveloped viruses, Sindbis virus and vesicular stomatitis virus, with cholesterol present in lipid vesicles and in serum was measured. Biosynthetically labeled viral cholesterol underwent spontaneous and complete transfer to both lipid vesicles and to serum. The rate with which and the extent to which this process occurred were very similar for these two viruses. During incubation with lipid vesicles in excess, half of the viral cholesterol underwent transfer in approximately 4 h and more than 90% underwent transfer in 24h at 37 degrees C. Similar rates and extents of movement of viral cholesterol were observed when incubations were carried out with vesicles which contained cholesterol and phospholipid in the same molar ratio as in the virus or with egg lecithin vesicles which contained no cholesterol. When labeled cholesterol was present initially in the lipid vesicles, movement of cholesterol from the vesicles to the virus was observed. One implication of the fact that viral cholesterol undergoes extensive exchange with serum cholesterol is that cellular cholesterol is in equilibrium with that in the extracellular fluid.

Carbon Radioisotopes↗
PubMed1975

Fatty acid chain flexibility in the membranes of normal and transformed fibroblasts.

Fatty acid spin labels were used to measure the inherent flexibility of the lipid acyl chains in intact cell membranes of 3T3 mouse fibroblasts and several varieties of transformed 3T3 cells. No significant differences in inherent lipid flexibility were detected in the normal and transformed mouse fibroblasts. These results are compared with similar results obtained earlier for chick embryo fibroblasts. For the cells studied, a difference in the mobility of membrane glycoproteins of normal and transformed fibroblasts has either been demonstrated directly or inferred from differential agglutinability by other investigations. Therefore, a basis for correlating glycoprotein mobility and lipid motion in these cells was not found.

Animals↗