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Biomedical subjects

K Lloyd

Publications and source records attributed to K Lloyd.

At least 19 recordsLinked to original sources
PubMed1995

Somatostatin inhibits B-cell secretion via a subtype-2 somatostatin receptor in the isolated perfused human pancreas.

Recently five somatostatin receptor subtypes (SSTR) have been cloned, allowing the development of highly specific selective agonists for these SSTR. The present study was undertaken to determine which SSTR is responsible for the inhibitory effect of somatostatin on islet hormone secretion. Single-pass perfusion of four agonists was performed in pancreata obtained from four cadaveric organ donors using a modified Krebs-media with 3.9 mM glucose. Sequential 10-min specific receptor agonist infusions (5 ng/ml) of DC32-87 (SSTR2), DC25-12 (SSTR3), DC32-97 (SSTR3), or DC32-92 (SSTR5) were performed in random order separated by 10-min basal periods. Infusion of SSTR2 agonist into the isolated perfused human pancreas resulted in a significant inhibition of insulin and C-peptide secretion (insulin = -1468 +/- 480 pM, P < 0.05, and C-peptide = -2328 +/- 437 pM, P < 0.05) but not islet amyloid polypeptide or somatostatin. These results suggest that the inhibitory effect of somatostatin on B-cell secretion is mediated through the subtype-2 receptor within the human islet.

Adolescent↗
PubMed1992

Psychotropic medication and ethnicity: an inpatient survey.

A survey of the catchment area psychiatric inpatient population of the Bethlem and Maudsley Hospitals showed that more black (Afro Caribbean) than non-black (white British) patients received anti-psychotic medication. This finding ceased to be significant after adjustment for diagnosis because a larger proportion of black than non black patients received a diagnosis of schizophrenia. However, after adjustment for diagnosis, black patients were significantly more likely to be receiving depot anti-psychotic medication, to be detained under a section and to have been involved in a violent incident during the present admission. There were no significant ethnic differences in total dose equivalents of anti-psychotic medication but doses of the depot form were significantly higher for black patients.

Adolescent↗
PubMed1987

Pancytopenia caused by bone marrow aplasia in a horse.

Pancytopenia was evaluated in a mature Quarter Horse gelding. A diagnosis of bone marrow aplasia was made on the basis of bone marrow hypocellularity. History of drugs administered included penicillin, oxytetracycline, trimethoprim-sulfadiazine, phenylbutazone, dipyrone, flunixin meglumine, and isoxsuprine. Clinical remission was observed after treatment with glucocorticoids, androgens, and broad-spectrum antimicrobials.

Animals↗
PubMed1987

Enteroliths in horses.

Many cases of enteroliths were reported in the nineteenth century but the number greatly decreased in the early twentieth century. However, in recent years the number of cases in certain parts of the United States such as California has greatly increased. The reasons for the increase are obscure. The intake of nitrogen, magnesium and phosphorus (the primary components of enteroliths) from water and food is likely to be a factor. Arabians may be more likely to develop enteroliths than horses of other breeds. A nidus such as a small stone is needed because a nidus has been found in every enterolith that has been examined. Further studies in which the effect of mineral intake and form of the mineral on enterolith formation are needed. Studies of enterolith formation in the past have all been retrospective. Models for the development of enteroliths are needed.

Animals↗
PubMed1985

Brain benzodiazepine receptor binding and purine concentration in Lesch-Nyhan syndrome.

Benzodiazepine receptor [( 3H]flunitrazepam) binding and purine concentration were measured in autopsied cerebral cortex of 4 patients who died with Lesch-Nyhan syndrome. Receptor density was normal in all 4 regions of Lesch-Nyhan cortex examined. However, an enhancement of benzodiazepine receptor affinity (25% reduction in Kd) was found in well-washed parietal and occipital cortex homogenates. Maximal gamma-aminobutyric acid (GABA) stimulation of [3H]flunitrazepam binding was normal in temporal, parietal and occipital cortex but markedly reduced (by 50-80%) in frontal cortex. Increased sensitivity to hypoxanthine inhibition (30% reduction in Ki) was also observed in parietal cortex. The concentrations of the purines hypoxanthine, xanthine and inosine in Lesch-Nyhan parietal cortex were about twice the values measured in control material matched for postmortem time. We suggest that the above-normal concentrations of purines estimated to be present in Lesch-Nyhan brain may be sufficient to significantly affect the ability of the benzodiazepine receptor to modulate GABA-mediated brain mechanisms.

Adolescent↗
PubMed1984

Establishment of a near-tetraploid B-cell lymphoma line with duplication of the 8;14 translocation.

The neoplastic cells of a patient with diffuse histiocytic lymphoma were grown in three systems: Soft agar, liquid culture, and by heterotransplantation into the nude mouse. In each case, the growing cells were shown to bear the same immunoglobulin heavy and light chain type as the original neoplastic cells (IgM-lambda). In both the liquid culture and nude mouse heterotransplant tumors, karyotypic analysis revealed the presence of pseudodiploid and near-tetraploid metaphases bearing one and two copies of an 8;14 translocation, respectively. From the liquid culture separate clones of pseudodiploid and near-tetraploid cells were isolated in soft agar, and separate cell lines SK-DHL2A and SK-DHL2B were established. Studies comparing the proliferative characteristics of the two lines showed no difference in cell population doubling time or clonigenicity in soft agar. Hence, the presence of two copies of the translocated material did not confer a proliferative advantage on cells containing it. Theses lines may be valuable in future studies of cell proliferation and oncogenesis in the human immune system.

Adult↗