Biomedical subjects
Publications and source records attributed to J Pitts.
69% of a sample of 54 male and 9 female police officers would have an anonymous test for AIDS. Willingness to have a test was associated with general self-protective behavior.
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The out of hours workload of a training practice in a suburban and semirural area on the south coast of England was studied for one year. An overall rate of contact of 273/1000 patients was found, which indicated a workload greater than that reported in most other studies. The duty doctor received over 35 telephone calls from patients during some Saturdays (1200 Saturday to 0800 Sunday) and Sundays (0800 to 0800 Monday), up to five being between 2300 and 0700. Of the patients who contacted a general practitioner, 44% were given advice by telephone and 4.9% were admitted to hospital. The admission rate was lower than that given in other studies. A considerable proportion of the workload arose from doctors covering the casualty department of a cottage hospital. Patients having a high expectation of 24 hour care by general practitioners in an area of comparative affluence (Jarman indices -13.8 to 1.7) may account for this aspect of the workload.
The aspartic proteinase chymosin exhibits a local network of hydrogen bonds involving the active site aspartates and surrounding residues which may have an influence on the rate and optimal pH of substrate cleavage. We have introduced into chymosin B the following substitutions: Asp304 to Ala (D304A), Thr218 to Ala (T218A) and Gly244 to Asp (G244D, chymosin A), using oligonucleotide-directed mutagenesis. Kinetic analysis of these active mutants shows shifts in their pH optima to 4.4 D304A, 4.2 T218A and 4.0 G244D compared with 3.8 for chymosin B using a synthetic octapeptide substrate. The upward shift of the D304A and T218A may be due to the loss of hydrogen bond interactions indirectly affecting the catalytic aspartates 32 and 215. The G244D mutation which is in a flexible loop on the surface of the enzyme may alter the conformation of the specificity pockets on the prime side of the scissile bond.
The earlier observation that students who had attempted suicide had lower scores on external locus of control than nonsuicidal ones was confirmed for 63 police officers. However, depression was associated with higher external scores.
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An audit of two practices in 1987 revealed a wide range of antibiotic prescribing for acute sore throat among the general practitioners. The data were presented at a postgraduate meeting and recommendations were made for a practice policy on antibiotic prescribing. The results of studies that looked at the objectives of treatment were included at that meeting. This paper presents a re-evaluation of the same doctors' antibiotic prescribing one-year later. Changes had occurred in the range and costs of drugs chosen, but individual doctors' prescribing rates remained broadly similar, in other words it was easier to influence what, but not whether, a doctor prescribes for this clinical condition. The existence of a prescribing 'threshold' within the individual doctor is supported.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Gap junctions provide pathways for direct communication between cells in almost all animal tissues. The junctional channels are freely permeable to small ions and molecules but not to macromolecules. A coupled cell population is as a consequence a partial syncytium, within which metabolites, cofactors, small control molecules and inorganic ions can all diffuse freely through the combined cytoplasmic compartment, while intracellular macromolecules remain relatively fixed in space, in the cells where they are synthesized. Little is known about the extent and distribution of these communication compartments in tissues. To further understand their significance, we have mapped the patterns of junctional communication in skin by intracellular injection of the tracer dye Lucifer Yellow. Cells in the dermal layer are widely coupled, with dye spreading through hundreds of cells in a few minutes. Dye spread in the epidermis is much more restricted, passing in the same time into only a few cells. Dermal-epidermal coupling is not normally detected but is occasionally seen in new-born mouse skin when hair follicles are starting to invaginate. Dermal cells are coupled to a band of follicular cells near the base of mature hair follicles, whereas sebaceous glands appear to be coupled units, isolated from surrounding cells.
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The insulin-like growth factors and hystricomorph insulins have been modelled by interactive computer graphics on the assumption that their sequence homology to insulin implies that they will have a similar tertiary structure. These studies suggest that, although the insulin-related molecules can adopt the insulin fold, they are unlikely to form hexamers and if they form dimers they will be of reduced stability. The non-suppressibility of insulin-like growth factors by anti-insulin antibodies is explained in terms of differences of surface residues in the region A8-A10 and B1-B5. Receptor affinity of insulins and insulin-like growth factors for insulin receptors is explicable in terms of a receptor-binding site in the vicinity of B25 Phe on the insulin surface. An equivalent region around B25 Tyr of insulin-like growth factors may be responsible for their binding to type 1 receptors, although binding type 2 receptors must involve a different surface region not shared by insulin.