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Biomedical subjects

J P Hardy

Publications and source records attributed to J P Hardy.

9 recordsLinked to original sources
PubMed1990

Retinal and choroidal vaso-occlusive disease in systemic lupus erythematosus associated with antiphospholipid antibodies.

Three patients with systemic lupus erythematosus (SLE) associated with anti-phospholipid antibodies are reported. All three had severe vaso-occlusive disease: the first had an unilateral vaso-occlusive retinopathy, the second an unilateral central retinal venous obstruction, and the third a bilateral ischemic choroidopathy. The association of these occlusive ocular vascular diseases with the presence of the lupus anticoagulant and other associated factors in SLE is discussed.

Adolescent↗
PubMed1987

Histamine-operated calcium channels in intestinal smooth muscle of the guinea-pig.

The effects of Bay K 8644 and of nifedipine on histamine-induced mechanical and electrical responses were studied in the longitudinal smooth muscle of the ileum and in the taenia coli isolated from the guinea-pig. Nifedipine (10(-9)-10(-7) M) depressed the tonic and phasic components of histamine contraction. Phasic tension was less sensitive to nifedipine inhibition than was tonic tension (I50: 27 +/- 6 and 2.6 +/- 0.4 nM respectively). Bay K 8644 (10(-8)-10(-7) M) increased tension and rhythmic activity of intestinal smooth muscle and potentiated the histamine responses. The phasic tension evoked by histamine 10(-5) M and the phasic tension evoked by the KCl depolarizing solution showed the same sensitivity to nifedipine inhibition (I50: 28 +/- 5 nM) and were similarly potentiated by Bay K 8644. The tonic tension in response to the KCl-depolarizing solution was more sensitive to nifedipine inhibition than was the tonic tension in response to histamine and was not potentiated by Bay K 8644. These results indicate that different Ca entry pathways, dependent or not on modification of the membrane potential, are involved in the contractile response evoked by histamine in intestinal smooth muscle.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1971

Photocatalytic Production of Organic Compounds from CO and H(2)O in a Simulated Martian Atmosphere.

[(14)C]CO(2) and [(14)C]organic compounds are formed when a mixture of [(14)C]CO and water vapor diluted in [(12)C]CO(2) or N(2) is irradiated with ultraviolet light in the presence of soil or pulverized vycor substratum. The [(14)C]CO(2) is recoverable from the gas phase, the [(14)C]organic products from the substratum. Three organic products have been tentatively identified as formaldehyde, acetaldehyde, and glycolic acid. The relative yields of [(14)C]CO(2) and [(14)C]organics are wavelength- and surface-dependent. Conversion of CO to CO(2) occurs primarily at wavelengths shorter than 2000 A, apparently involves the photolysis of water, and is inhibited by increasing amounts of vycor substratum. Organic formation occurs over a broad spectral ranger below 3000 A and increases with increasing amounts of substratum. It is suggested that organic synthesis results from adsorption of CO and H(2)O on surfaces, with excitation of one or both molecules occurring at wavelengths longer than those absorbed by the free gases. This process may occur on Mars and may have been important on the primitive earth.

Journal Article↗