Regional survey of femoral neck fractures.

In the South-west Thames Region 2619 patients (2105 women and 514 men) were discharged with a diagnosis of femoral neck fracture in 1974. The equivalent of a 250-bedded hospital was occupied throughout the year. The incidence, average length of stay, and mortality rate rose with increasing age and there were differences in these indices in the five health areas. These results confirm the enormous burden placed on the hospital service by patients with fracture of the femoral neck but suggest that differences in practice in the five areas may contribute to the size of the problem.     

Characterization of transverse tubule membrane proteins: tentative identification of the Mg-ATPase

Vesiculated fragments of chicken skeletal muscle transverse tubule (TT) membranes were analyzed for their content of loosely associated and integral membrane proteins. Of particular interest was the identification of the magnesium-stimulated ATPase (Mg-ATPase), which is characteristically located in native isolated TT vesicles of chicken skeletal muscle [R. A. Sabbadini and V. R. Okamoto (1983) Arch. Biochem. Biophys. 223, 107-119]. A number of the proteins found in vesicular TT preparations were found to be extractable by a mild Triton-X100 treatment and were identified as aldolase, enolase, creatine kinase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and pyruvate kinase. Approximately 60% of TT-associated protein was extracted with Triton, resulting in a twofold enrichment of the Mg-ATPase. Concommitantly, one core integral membrane protein possessing a Mr of 102,000 was enriched, suggesting that it is responsible for the Mg-ATPase activity present in chicken skeletal muscle TT membranes.     

Flow cytometric determination of DNA content in malignant and benign bone tumours

The nuclear DNA content of 38 malignant and 25 benign bone tumours was measured by flow cytometry. The specimens were taken either from biopsies or from surgical specimens. Seventeen of 26 primary malignant bone tumours were aneuploid, 15 had a single aneuploid DNA content, and 2 had a biclonal abnormality. Thirteen of 15 osteosarcomas were aneuploid, but only 2 of 6 chondrosarcomas showed an aneuploid DNA content. Six of 12 metastatic malignant bone tumours were also aneuploid. All 25 benign tumours had a diploid DNA content. Cell cycle analysis showed that the proportion of cells in S- and G2M-phases was higher in the malignant compared to benign tumours, indicating a higher proliferative activity. The increase was statistically significant (p less than 0.05) both in diploid and in aneuploid tumours. Among five tumours studied after chemotherapy, four displayed a marked hyperdiploid abnormality. Aneuploidy and high proliferative activity both were highly associated with malignant bone tumours, suggesting that DNA flow cytometry may be an adjunct in the assessment of malignancy of bone tumours.     

Isolation of Aeromonas caviae from ice-cream

Sixty-four samples of ice-cream were examined for the presence of Aeromonas species. Culture was by direct inoculation onto xylose deoxycholate citrate agar and into alkaline peptone water. Aeromonas caviae was isolated from three of the 64 samples (4–7%). The potential pathogenic significance of this organism in ice-cream is discussed.     

Possible involvement of acyltransferase systems in the formation of pulmonary surfactant lipid in rat

Dithiobis (2-nitrobenzoic acid)-resistant and -sensitive glycerophosphate acyltransferase systems were present in rat lung as in liver. The former was specific for palmitate while the latter could incorporate saturated and unsaturated acyl-CoAs comparably. The former has higher affinity for palmitate than the latter indicating that the 1-position of glycerophosphate can be acylated selectively with palmitate under certain conditions. The specificities of 1-acylglycerophosphate and 1-acylglycerophosphocholine acyltransferase systems were similar in lung and liver; both systems showed higher specificities for unsaturated acyl-CoAs. However, the selectivities observed at lower concentrations of phospholipid acceptors in the presence of equimolar mixtures of saturated and unsaturated acyl-CoAs were much different; the lung systems showed relatively higher selectivities for palmitate than the liver systems in the formation of both diacylglycerophosphate and phosphatidylcholine. On the other hand, palmitate was excluded almost completely from the 2-position in the 1-acylglycerophosphoethanolamine acyltransferase systems in lung and liver. These observations provide an enzymatic basis for describing the formation of pulmonary surfactant lipids in rat via acyltransferase systems.     

Inhibition of dehydration-induced fusion between liposomal membranes by carbohydrates as measured by fluorescence energy transfer

The relative abilities of a number of naturally occurring carbohydrates to inhibit dehydration-induced fusion between palmitoyloleoylphosphatidylcholine:phosphatidylserine (85:15) large unilamellar vesicles have been studied. Fusion events were quantified using a fluorescence resonance energy transfer technique. Trehalose was most effective at inhibiting fusion (0.4 g/trehalose/g lipid showed 30% probe intermixing), followed by maltose (60% intermixing), fructose (60%), sucrose (70%), glucose (80%), cellobiose, glycerol, raffinose, and myo-inositol (90%). The relative abilities of these carbohydrates to inhibit fusion correlate directly with their abilities to interact with phospholipids, maintain bilayer fluidity, and preserve biological membranes. The results are discussed in relation to the crystalline structure of the carbohydrates and their possible influence on level of interaction with phosphate head groups.