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Biomedical subjects

D Shaw

Publications and source records attributed to D Shaw.

At least 235 records · Page 13Linked to original sources

Oleander poisoning.

The two common oleanders, Thevetia peruviana and Nerium oleander, contain a mixture of poisons including cardiac glycosides, and are extremely toxic. They are cultivated universally throughout Australia, and rank equally with mushrooms as the major cause of children's admission to hospital after accidental plant ingestions. A seven-year total population survey from south-east Queensland has revealed that, in practice, the rate of clinical poisoning due to oleander is inconsequential, and mortality is negligible. The annual age-specific admission rate for children (aged from birth to 12 years of age), for all plant ingestions is 2.33 per 100 000, and 0.62 per 100 000 specifically for oleander. Oleander ingestion causes a syndrome of combine cardiac and gastrointestinal symptoms and signs. A case series of 13 children is described, and the clinical features summarized. After accidental oleander ingestion, current experience indicates that the prognosis is excellent.

Antidotes↗

Thrombocytosis, thrombocythaemia and iron deficiency in patients with polycythaemia vera.

6 patients with polycythaemia vera who also developed concomitant iron deficiency are reported. When oral iron therapy was given, there was a marked reduction in the previously elevated platelet counts in 4 patients; during 2-9 years of observation of these patients there was a significant inverse relationship between haemoglobin concentration and platelet count. In the other 2 patients the elevated platelet counts did not fall when iron therapy was given. The significance of these different patterns of response in relation to the causal mechanism of elevated platelet counts in patients with polycythaemia vera is discussed.

Aged↗

Benzopyrones. 14. Synthesis and antiallergic properties of some N-tetrazolylcarboxamides and related compounds.

A series of chromones containing an acidic group has been synthesized and screened for the ability to inhibit passive cutaneous anaphylaxis and the release of histamine from mast cells of the rat. Many of the chromones contain the N-(5-tetrazolyl)carboxamido group, a novel source of acidity. Others contain a carboxyl, C-(5-tetrazolyl), 5-(4H)-oxotetrazolinyl, or N-(5-tetrazolyl)sulfonamido function. The compounds were compared with cromolyn sodium (sodium cromoglycate) and many were found to be powerful inhibitors of anaphylaxis. The most potent was 7-methoxy-4-oxo-N-(5-tetrazolyl)-4H-1-benzopyran-2-carboxamide (15). Structure-activity relationships among the chromones and also some related compounds are discussed.

Anaphylaxis↗

Characterization of gastric mucosal membranes. IX. Fractionation and purification of K+-ATPase-containing vesicles by zonal centrifugation and free-flow electrophoresis technique.

Methods are described for purification of a vesicular membrane fraction of hog gastric mucosa using differential centrifugation, density gradient separation on zonal rotors and free-flow electrophoresis. As a result a fraction is obtained enriched 40-fold in terms of K(+)-ATPase and free of any other enzyme marker other than K(+)-activated p-nitrophenyl phosphatase. The 5'-nucleotidase and basal Mg(2+)-ATPase are clearly separated from the latter enzymes. Osmotic shock, Triton X-100 treatment or K+ ionophores increased the K(+)-ATPase activity in isotonic conditions, but K(+)-p-nitrophenyl phosphatase is not affected by these treatments, nor is the ATPase activity in the presence of NH4+. The results suggest that the electrophoretic fraction contains a major population of tight vesicles, whose permeability to K+ is rate limiting for the ATPase activity but not for the p-nitrophenyl phosphatase activity. It is concluded that K+ site for the ATPase is internal whereas the K+ site for the p-nitrophenyl phosphatase is external, hence, the K+ site must be mobile across the membrane.

4-Nitrophenylphosphatase↗

Intrachromosomal gene mapping in man: assignment of nucleoside phosphorylase to region 14cen leads to 14q21 by interspecific hybridization of cells with a t(X;14) (p22;q21) translocation.

The structural gene for purine-nucleoside phosphorylase (NP) has been assigned to a subregion of chromosome 14 by somatic cell hybridization of male and female cells containing the balanced translocation t(X;14) (p22;q21). Peripheral lymphocytes were fused to a pseudodiploid HPRT-deficient established Chinese hamster cell line. 23 primary hybrid clones (10 derived from male and 13 from female cells) were isolated and maintained in HAT selective medium. Parallel subcultures from generations 16, 24, and 40 after clonal isolation were fully karyotyped and analyzed electrophorectically for expression of the human types of NP, HPRT, G6PD, and PGK. The human NP phenotype segregated discordantly with each human chromosome except chromosome 14 and the der(14),t(X;14) translocation chromosome. In all, 8 hybrids which had retained the der(X), t(X;14) translocation chromosome under HAT selective pressure and expressed human HPRT had lost the human NP phenotype. These results indicate localization of the NP gene in region 14pter leads to 14q21.

Adenine Phosphoribosyltransferase↗

Evaluation of left ventricular performance in acutely ill patients with chronic obstructive lung disease.

Among 28 patients with chronic obstructive pulmonary disease (COPD) with increasing dyspnea, the resting mean pulmonary arterial wedge pressure was elevated (greater than 12mm Hg) in 4 and became abnormal with exercise in 3 other subjects. Stroke volume index was reduced (less than 36 ml/beat/M2) in 16 of 26 patients (62 percent). The resting pre-ejection period index was prolonged (greater than 144 msec) in 17 patients (65 percent), while the left ventricular (LV) ejection time index was reduced (less than 408 msec) in 23 patients (88 percent). The ratio of the pre-ejection period to the LV ejection time was within the normal range (0.309 to 0.381) in only 3 of 26 patients (12 percent). Echocardiographic measurements of LV function were normal in nine patients, seven of whom had one or more abnormal values for systolic time intervals (STIs). These data suggest that reduced LV filing results in abnormal values for STIs in patients with COPD, and therefore that in such patients STIs are not accurate indices of LV function.

Aged↗