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Biomedical subjects

G B Ryan

Publications and source records attributed to G B Ryan.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Syntheses of haptens containing dioxaphosphorinan methoxyacetic acid linker arms for the production of antibodies to organophosphate pesticides.

Four generic heterobifunctional reagents, namely 2-(2-chloro-5-methyl-1,3,2-dioxaphosphorinan-5-yl)methoxyacetic acid methyl ester, p-sulfide, 2-(2-chloro-5-methyl-1,3,2-dioxaphosphorinan-5-yl)-methoxyacetic acid methyl ester, p-oxide, 2-(2-mercapto-5-methyl-1,3,2-dioxaphosphorinan-5-yl)-methoxyacetic acid bispotassium salt, p-sulfide-, and (2-methoxy-5-methyl-1,3,2-dioxaphosphorinan-5-yl)methoxyacetic acid, methyl ester, have been synthesized and used to prepare organophosphate, thiophosphate, and dithiophosphate haptens containing a functional carboxyl group which can be used to conjugate the haptens to proteins. These hapten-protein conjugates have been used as antigens for preparing polyclonal sera against all classes of organophosphate pesticides. The eight examples used protein-hapten conjugates of chlorpyrifos, parathion, diazinon, paraoxon, azinphos, dimethoate, demeton, and dichlorvos. These were all immunogenic and resulted in sera containing antibodies that recognized the corresponding parent pesticide with high specificity.

Acetates↗
PubMedDate not supplied

Use of synthetic oligonucleotide and recombinant DNA probes to study renin gene expression.

Using hybridization histochemistry renin gene expression has been localized in the juxtaglomerular apparatus (JGA) of the renal cortex in both mouse and sheep kidney. This technique also located renin gene expression in afferent arterioles and interlobular arteries distant from the glomerular tuft in lamb renal cortex. A short (30 mer) synthetic oligonucleotide probe, complementary to a region of the mouse submaxillary gland renin gene, specifically labelled mouse submaxillary gland and kidney. Hybridization histochemistry and Northern blot analysis using both the synthetic oligonucleotide (mouse) probe and a 700 base pair recombinant (sheep) probe showed differences in renin gene expression in the kidney in response to Na restriction in the mouse and Na depletion in the sheep.

Animals↗
PubMedDate not supplied

Angiotensin converting enzyme inhibition in the postnatal rat results in decreased cell proliferation in the renal outer medulla.

1. Chronic angiotensin converting enzyme (ACE) inhibition or AT1 antagonism during postnatal development in the rat has been shown to cause renal tubular and vascular damage, particularly in the outer medulla. 2. The effects of ACE inhibition were investigated at a stage of development before the renal outer medulla is fully established. 3. Sprague-Dawley rat pups were given daily i.p. injections of either enalapril or saline from days 3-10. At day 11, kidneys were perfusion-fixed for either electron microscopy or immunocytochemistry. Sections were incubated in proliferating cell nuclear antigen (PCNA) antisera and the avidin-biotin immunoperoxidase method was used to detect an immunoreactive product, indicative of proliferating cells. 4. Following enalapril treatment, the normal structural arrangement of the outer medulla was disrupted compared with controls. Cell proliferation (PCNA-positive cells) in the medullary rays was reduced in enalapril-treated kidneys compared with control kidneys. 5. Thus, angiotensin II appears to be essential for normal tubular and vascular growth in postnatal renal development in the rat.

Angiotensin-Converting Enzyme Inhibitors↗