Muramic Acid Assay in Sediments

An improved chromatographic assay for muramic acid which is sufficiently sensitive for marine sandy sediments is described; it involves acid hydrolysis, thin-layer chromatography, and gas-liquid chromatography.     

Steroid sulphatase levels in XX males,including observations on two affected cousins

Summary Quantitative assays of steroid sulphatase in XX males have shown that some individuals have two functional loci, and others only one. Two affected cousins, who cannot share the same X-chromosome, nevertheless have male levels of steroid sulphatase, suggesting functional abnormality of the X chromosome.The hypothesis is advanced that these and other unusual features of X-chromosome function in some XX males, could be explained if such cases were due to an autosomal mutation, exercising its effect by causing abnormal inactivation of a subterminal area of Xp which normally escapes the inactivation process.     

Survey of sickle-cell disease in England and Wales.

The incidence and the clinical course of patients suffering from sickle-cell syndrome (Hb SS; Hb SC; Hb S thal) in England and Wales are not known. In 1979 an ad hoc committee was formed to investigate these problems. Initially, a questionnaire was sent to 227 haematologists in England and Wales to determine the number of cases in these countries. The replies have indicated that 1367 cases were seen in 1978 and 1979. Probably this may represent only half the total number of cases. From this survey it has been possible to draw up a composite map showing the location of patients, which has provided a basis to determine the clinical course of the disease, and for further studies into the complications and management of sickle-cell disease in England and Wales. From a second questionnaire preliminary data about the general management and mortality in England and Wales have been recorded.     

The annual lipid cycle and feeding behavior of Alaskan redpolls

Summary Total lipids were extracted from 161 redpolls (Acanthis spp.) collected each month of the year from October 1962 to September 1963, in interior Alaska. A lipid index (Weight of ether extract x100/live body weight) was calculated for each sample. Lipids were also extracted from sections of pectoral muscle, livers and hearts representing each month.Body weight and lipid index were significantly positively correlated being highest in January and lowest in September. Total lipid content was significantly inversely correlated with air temperature; the high autumn and spring pre-migratory lipid peaks of migratory species were only weakly expressed in the redpolls. Liver lipid showed a significant annual variation being highest in December and lowest in August, while lipid from heart and pectoral muscle did not vary seasonally.Five birds were held in captivity during spring and summer at a constant temperature of 22°C. Food consumption was 5.1 g/day or 22.4 kcal. The caloric value of the most extensively utilized natural food, birch seed (Betula papyrifera), was determined (5.4–5.5 kcal/g dry wt). When esophageal diverticulae are full (2.0 g wet wt) of birch seeds, the resulting energy yield may sustain an individual for only a fraction of a 24 h winter day in contrast to other arctic herbivores (e.g. ptarmigan, Lagopus sp.) in which a full crop may suffice for the full 24 h period.     

Requirements for extraction of polyribosomes from plant callus cultures

Zone sedimentation through sucrose gradients was used for preparing Rhizobium bacteroids from lupin nodules and for separating them into slowly and rapidly sedimenting fractions.     

Factors influencing the susceptibility of Candida albicans to the polyenoic antibiotics nystatin and amphotericin B.

Factors influencing the interaction between Candida albicans and the polyenoic antibiotics nystatin and amphotericin B have been investigated using a K+-specific electrode to measure polyene-mediated efflux of cellular K+. In batch cultures, sensitivity was a function of culture age. Using continuous (chemostat) cultures, the influence of growth-limiting substrate, specific growth rate, growth temperature and growth pH were examined. Carbon-limited cultures showed the highest sensitivity of those substrates tested, and susceptibility increased with growth rate. Within the range 22 to 42 degrees C, growth at lower temperatures resulted in increased sensitivity, whilst a similar trend was observed when the growth pH of cultures was reduced. Further, under the conditions tested, there were considerable variations in free intracellular K+ concentrations.