Renal tubular acidosis in pregnancy

Two pre-eclamptic females were seen in consultation by the Renal Service. Both had Renal Tubular Acidosis (RTA). One case resulted from the possible exacerbation of Lupus Erythematosus. The other patient's RTA seemed to be related to ingestion of Dyazide for pre-eclampsia. Delivery of the child in the first case and discontinuance of Dyazide in the second resulted in the abrupt disappearance of RTA.

Motility mutants of Dictyostelium discoideum

We describe six motility mutants of Dictyostelium discoideum in this report. They were identified among a group of temperature-sensitive growth (Tsg) mutants that had been previously isolated using an enrichment for phagocytosis-defective cells. The Tsg mutants were screened for their ability to produce tracks on gold-coated cover slips, and several strains were found that were temperature-sensitive for migration in this assay. Analysis of spontaneous Tsg+ revertants of 10 migration-defective strains identified six strains that co-reverted the Tsg and track formation phenotypes. Characterization of these six strains indicated that they were defective at restrictive temperature in track formation, phagocytosis of bacteria, and pseudopodial and filopodial activity, while retaining normal rates of oxygen consumption and viability. Because they had lost this group of motile capabilities, these strains were designated motility mutants. The Tsg+ revertants of these mutants, which coordinately recovered all of the motile activities, were found at frequencies consistent with single genetic events. Analysis of the motility mutants and their revertants suggests a relationship between the motility mutations in some of these strains and genes affecting axenic growth.

The design and interpretation of case-control studies of perinatal mortality

The difficulty of designing prospective studies of perinatal death makes the case-control study a method of choice. The particular problems associated with the identification of risk factors, the definition and enumeration of cases, and the selection of live birth controls in such a study, undertaken on all perinatal deaths occurring in a population of 850,000 people during 1976-1978 are described. The method of control selection, chosen for reasons of feasibility, produced a nonrepresentative sample of controls. This was because controls were selected as the next live birth in the place of delivery where the perinatal death delivery occurred, which resulted in a sample stratified by place of delivery. Knowledge of the place of delivery of all births allowed a correction to be undertaken which was derived from the relative weights for the strata within which matching had occurred.

Characterization of a novel calmodulin from Dictyostelium discoideum

We have purified calmodulin from the eukaryotic microorganism Dictyostelium discoideum (Clarke, M., Bazari, W. L., and Kayman, S. C. (1980) J. Bacteriol. 141, 397-400) and have compared it to calmodulin purified from bovine brain. The two proteins behaved almost identically during fractionation on ion exchange and gel filtration columns and on isoelectric focusing gels. Dictyostelium calmodulin had one-third the specific activity of brain calmodulin in the Ca2+-dependent activation of brain cyclic nucleotide phosphodiesterase; this activation was inhibited for both proteins by 25 microM trifluoperazine. Dictyostelium calmodulin also activated erythrocyte (Ca2+ + Mg2+)-ATPase and interacted with the inhibitory subunit of skeletal muscle troponin. Competition radioimmune assays showed that Dictyostelium calmodulin could compete with brain calmodulin for antibodies to brain calmodulin. These similarities indicate a close relationship between Dictyostelium and brain calmodulin and suggest that the functional capabilities of the protein have been conserved even among evolutionarily distant species. However, substantial differences in primary structure were detected by amino acid analyses and peptide mapping. Most interesting is the lack of trimethyllysine in Dictyostelium calmodulin. This unusual amino acid, which is commonly found in calmodulins, is therefore not essential for interaction between calmodulin and the calmodulin-regulated proteins tested here.

The elderly in residential care: mortality in relation to functional capacity

A census in which 4514 people aged 65 and over had been enumerated in all types of institutional care both within and outside the National Health Service in Leicestershire was taken as a starting point for the present investigation. This entire population was followed up for one year to determine its mortality experience. Mortality was described by three measures: (a) the proportion surviving for one year from the date of the census, (b) the standardised mortality ratio (using the population of Leicestershire in 1977 as a standard), and (c) using a life-table analysis, the percentage survival to specified time periods after admission to institutional care. We discuss the relationship of these indices to functional capacity, indicated by the ability to undertake basic activities of daily living (ADL), and to type of institution.