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Biomedical subjects

J Moss

Publications and source records attributed to J Moss.

At least 505 records · Page 28Linked to original sources
PubMed1982

Histamine release by neuromuscular blocking agents in man.

Several experimental and clinical studies have suggested that histamine is released following the administration of neuromuscular blocking agents, and that the histamine release is an important aspect in the hemodynamic response to the drug. We have measured plasma histamine following the administration of a series of neuromuscular blocking agents in man. Our data suggests that members of this class of drugs can cause a dose dependent release histamine release in man and that this release is hemodynamically significant. We have also evaluated the roles of rate of administration, of pretreatment with H1 and H2 antagonists and alterations in drug design as clinical strategies in attenuating the adverse reactions. The data obtained in humans can be shown to validate the cat model as a means of screening novel neuromuscular blocking agents.

Animals↗
PubMed1982

Resolution and activity of adenylate cyclase components in a zwitterionic cholate derivative [3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate].

Bovine brain adenylate cyclase was solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), sodium cholate, sodium deoxycholate, or these detergents plus (NH4)2SO4. The specific activity of the extract obtained with 13 mM CHAPS alone was several times those of the other detergent extracts with or without (NH4)2SO4. After solubilization with 13 mM CHAPS, gel filtration completely separated the catalytic unit (C) from the guanine nucleotide binding protein (G/F). C activity when assayed with 5 mM Mn2+ was 5 times that assayed with 10 mM Mg2+ and was unresponsive to GPP(NH)P. C activity was increased approximately 150% by GPP(NH)P in the presence of G/F extracted from human erythrocyte ghosts and approximately 100% by Ca2+ plus calmodulin in assays with Mg2+. On gel filtration and/or density gradient centrifugation, the physical properties of C from brain or AC- cells and G/F from bovine or pig erythrocytes in CHAPs were similar to those observed in other detergents. It appears that the use of CHAPS for solubilization of adenylate cyclase and separation of C and G/F may well prove advantageous in studies of the molecular interactions between the protein subunits and activators of the enzyme as well as for the initial purification of C.

Adenylyl Cyclases↗
PubMed1982

Modulation of collagen production by fibroblasts. Effects of chronic exposure to agonists that increase intracellular cyclic AMP.

Cultured human lung fibroblasts were evaluated for their responsiveness to isoprenaline (isoproterenol) or prostaglandin E2 before and after chronic incubation with the agonist. Cells incubated for 6 h with either agonist were suppressed in terms of collagen production and exhibited increased intracellular cyclic AMP. Cells incubated for 72 h with the agonist and then re-challenged for 6 h with the same agonist did not demonstrate suppressed collagen production or increased cyclic AMP. Cells incubated for 72 h with isoprenaline still responded to prostaglandin E2 when challenged for 6 h; however, when the order of agonist exposure was reversed, cells incubated with prostaglandin E2 did not respond to a challenge by isoprenaline. If cells were allowed to recover for 48 h without the agonist after a 72 h chronic incubation, they recovered their responsiveness to the agonist. The results indicate that, although cultured fibroblasts may become desensitized to one agonist, they may retain their sensitivity to a second agonist and chronic suppression of collagen production may be achieved by alternate exposure to isoprenaline and prostaglandin E2.

Cell Line↗
PubMed1982

Activation of an NAD:arginine ADP-ribosyltransferase by histone.

An ADP-ribosyltransferase from turkey erythrocytes which utilizes proteins and low molecular weight guanidino compounds such as arginine and agmatine as ADP-ribose acceptors was stimulated by histones. The effect was specific in that choleragen, a bacterial mono(ADP-ribosyl)transferase that increased adenylate cyclase activity in animal cells, was not activated by histones. With the erythrocyte enzyme, histones decreased the apparent Km values for arginine methyl ester and agmatine and increased the stability of the transferase to thermal denaturation. Activation of the transferase by histones was rapid, with a minimal delay observed upon addition of histones to a histone-free assay. Activation by histones was reversed upon dilution of a sample containing histones into an assay mix free of histone. In the absence of histone, the transferase existed as a rapidly sedimenting species; in the presence of histone, the transferase sedimented as a protomer.

ADP Ribose Transferases↗
PubMed1982

Choleragen-stimulated release of guanyl nucleotides from turkey erythrocyte membranes.

Choleragen stimulates adenylate cyclase by ADP ribosylating a guanyl nucleotide-binding regulatory protein (G/F). beta-Adrenergic hormones also activate the adenylate cyclase of turkey erythrocytes, and it is currently believed that they do so in part by decreasing the affinity of G/F factor for GDP, an effect which is manifested by a hormone-stimulated release of guanyl nucleotides from the membranes. Since choleragen might also activate adenylate cyclase by a similar mechanism, the effect of toxin treatment on the release of guanyl nucleotides from turkey erythrocyte membranes was examined. In the presence of NAD, choleragen was found to stimulate release of guanyl nucleotides from membranes which had been preloaded with radiolabeled GTP. No stimulation of release was observed with cAMP or when NAD was replaced by NADP, which does not serve as a substrate for choleragen-catalyzed ADP ribosylation. While either isoproterenol or choleragen can stimulate release of guanyl nucleotides from the membranes, the amount of guanyl nucleotide released in the presence of both isoproterenol and choleragen was no greater than that released by isoproterenol alone. Furthermore, when membranes were first treated with choleragen and NAD, the subsequent release of guanyl nucleotides induced by isoproterenol was reduced to approximately 15% of that observed with membranes not treated with the toxin. Therefore, choleragen may enhance release of guanine nucleotides from sites on the membranes that are also affected by beta-adrenergic agonists, sites which are thought to correspond to G/F. These data are consistent with the hypothesis that choleragen may stimulate adenylate cyclase, in part, by enhancing release of guanyl nucleotides, a mechanism similar to that of beta-adrenergic agonists.

Animals↗
PubMed1982

Severity of glomerulonephritis induced in different strains of suckling mice by infection with lymphocytic choriomeningitis virus: correlation with amounts of endogenous interferon and circulating immune complexes.

Renal lesions due to neonatal infection with lymphocytic choriomeningitis virus were studied in three different strains of mice known to produce different amounts of viral interferon. Very severe ultrastructural lesions similar to those induced by exogenous interferon were found as early as day 8 in C3H mice which produced the highest amount of interferon. Further studies could not be performed in these mice since all died by day 14. Balb/c mice produced the lowest amount of interferon and had very mild ultrastructural lesions. An intermediate pattern was found in Swiss mice. After 30 days of infection, severe immune complex type glomerulonephritis detectable by light microscopy and immunofluorescence was observed in Swiss mice whereas mild lesions only were found in Balb/c mice. Circulating immune complexes were present in both strains but in greater amounts of Swiss than Balb/c mice. These results suggest that two factors at least are important in the development of glomerulonephritis: interferon produced early in life and the load of circulating immune complexes.

Animals↗
PubMed1982

Histamine release during morphine and fentanyl anesthesia.

High doses of morphine produced peripheral vasodilation and frequently significant hypotension. These effects are thought to be due, in part, to the release of histamine. One putative advantage of high-dose fentanyl anesthesia is its relatively small effect on peripheral vascular resistance. In a randomized study, the authors examined the possibility that the hemodynamic differences between morphine and fentanyl might be attributable to histamine release. Fifteen patients were studied prior to coronary artery bypass surgery. Subjects received in infusion of morphine (1 mg . kg-1, iv at 100 micrograms . kg-1 . min-1 [n = 8]) or fentanyl (50 micrograms . kg-1 at 5 micrograms . kg-1 . min-1 [n = 7]). Patients in the morphine group had an average 750 per cent peak increase in plasma histamine accompanied by a significant decrease in mean arterial pressure (-27 mmHg- and systemic vascular resistance (-520 dyne . s . cm-5). The greatest decrease in systemic vascular resistance occurred in those patients with the highest levels of plasma histamine (r = -0.81). Patients in the fentanyl group had no change in plasma histamine and no decrease in arterial pressure or systemic vascular resistance. Cardiac output and heart rate were comparable between the two groups. Differences in the release of histamine account for most, if not all, of the different effects of morphine and fentanyl on the peripheral vasculature.

Anesthesia↗
PubMed1982

Interferon as a cause of endoplasmic reticulum abnormalities within hepatocytes in newborn mice.

An ultrastructural examination of livers from newborn mice, injected with potent partially purified or highly purified mouse interferon or with lymphocytic choriomeningitis (LCM) virus, has revealed the presence of tubular aggregates associated with the granular endoplasmic reticulum in the cytoplasm of hepatocytes after either treatment. Thus the lesion was observed in A2G and Swiss mice after interferon injections. It was also seen in C3H mice after LCM infection, the liver being examined at a time when the interferonaemia in the injected mice was known to be at its peak. The aggregate resembles the tubular systems associated with the endoplasmic reticulum described in various tissues in both human and animal diseases. These observations raise the possibility that in some of the cases previously described the lesion has been interferon induced.

Animals↗