Biomedical subjects

P Shirley

Publications and source records attributed to P Shirley.

21 records · Page 2Linked to original sources

PubMed1985

Daily patterns of serotonin uptake in platelets from psychiatric patients and control volunteers.

Serotonin (5-HT) uptake into platelets from psychiatric patients and controls was measured in the morning and afternoon. Uptake varied with time of day in both groups studied, resulting in four recognizable patterns. Two patterns occurred in the majority of controls. In contrast, uptake patterns in the psychiatric patients were more variable, with each of the four patterns clearly represented. However, except for the fact that uptake was significantly decreased throughout the day in depressed patients, the patterns were not otherwise linked statistically to clinical condition. In any event, the greater variability of daily 5-HT uptake patterns in patients suggests that psychiatric disorders linked presumably to central nervous system (CNS) dysfunction are in some way reflected by labile platelet 5-HT pharmacokinetics.

Adolescent↗

PubMed1981

Interaction of Vibrio vulnificus with human polymorphonuclear leukocytes: association of virulence with resistance to phagocytosis.

The results of studies described in this report support the ideas that virulence of Vibrio vulnificus is associated, at least in part, with resistance to phagocytosis and that the ability of the bacterium to resist phagocytosis results from its possession of an antiphagocytic surface antigen. These conclusions are based on the observations that (1) human polymorphonuclear leukocytes (PMNLs) exhibited a significantly weaker chemiluminescent response and phagocytic response when interacting with a virulent strain of the bacterium than when challenged with a weakly virulent strain of the bacterium; (2) rabbit antiserum to the virulent bacterium, but not normal rabbit serum, significantly enhanced the chemiluminescent response of PMNLs challenged with the virulent bacterium and significantly enhanced ingestion of the bacterium by the PMNLs; and (3) the opsonic activity of the antiserum was removed by adsorption with a formalin-killed, whole cell preparation of the virulent bacterium.

Animals↗

PubMed1977

Polymorphonuclear leukocyte bactericidal activity and oxidative metabolism during glutathione peroxidase deficiency.

Glutathione peroxidase (GPx) deficiency has been proposed as a cause of some instances of chronic granulomatous disease (CGD). GPx activity varies greatly among species, and specific deficiency of this selenium-dependent enzyme can be produced by dietary selenium deficiency in rats. Bactericidal activity of polymorphonuclear (PMN) leukocytes from normal rats, humans, and guinea pigs (GPx high, intermediate, and nearly absent, respectively), selenium-deficient rats (GPx absent), and a patient with CGD were compared. There was no correlation between natural levels of GPx and bactericidal activity; only CGD was associated with inability to kill a Proteus mirabilis strain in vitro (killing known to be dependent on oxidative mechanisms). Postphagocytic metabolism was examined in normal and GPx-deficient rats. Both demonstrated normal iodination and superoxide production during phagocytosis and gave similar histochemical reduction of nitroblue tetrazolium dye under either resting or endotoxin-stimulation conditions. Postphagocytic hexose monophosphate shunt activity was somewhat lower in PMN from GPx-deficient animals as compared with normal but was substantially (10-fold) higher than that observed in resting cells. Thus, postphagocytic oxidative responses and subsequent bactericidal activity of PMN leukocytes were not compromised by complete absence of GPx, even in the species with the highest natural level of this enzyme. These results are not compatible with the hypothesis that CGD can be caused by a deficiency of GPx.

Animals↗