Effect of operant conditioning of heart rate on plasma renin activity

Cardioacceleration produced by operant conditioning was associated with elevation of plasma renin activity. This study suggests that emotional stimuli, which produce cardioacceleration, may also cause increased renin secretion, thus providing a mechanism by which factors operating through the mind and sodium intake could summate in the production of hypertension.     

Unique peptide maps of the three largest proteins specified by the flavivirus Kunjin

Tryptic digests of four polypeptides found in Kunjin virus-infected Vero cells, NV5, NV4, V3, and NV3, were compared by peptide mapping. The polypeptides to be analyzed were labeled with radioactive methionine and separated by electrophoresis through polyacrylamide gels containing sodium dodecyl sulfate. Because infection of Vero cells by Kunjin virus does not inhibit host cell protein synthesis, radioactively labeled viral polypeptides prepared from infected cells migrate coincidentally during sodium dodecyl sulfate-gel electrophoresis with some of the labeled host proteins. Thus, the genuine viral methionine-containing peptides in tryptic digests of viral proteins have been identified by co-analyzing polypeptides from [3H]methionine-labeled uninfected cells and [35S]methionine-labeled infected cells and determining the 35S/3H ratio in the peptides resolved in two dimensions on thin-layer chromatography plates. The peptide map of NV3 demonstrated that it is host coded, whereas NV5, NV4, and V3 have unique peptide maps and, therefore, account for approximately one-half of the coding potential of Kunjin virus RNA.     

Antibodies to Candida after operations on the heart

In order to determine the frequency of hypoxaemia and to evaluate the role of increased closing capacity in producing hypoxaemia in patients with cirrhosis of the liver, 13 patients with well-established cirrhosis were studied. Arterial blood gases, spirometry, lung volume, and closing capacity measurements were made with the patients in the seated and recumbent positions after exclusion of cardiopulmonary dysfunction. Four of 13 and six of 12 patients exhibited significant hypoxaemia in the seated and recumbent positions respectively. Five of 13 patients showed a closing capacity greater than predicted. This frequency of increased closing capacity was not higher than in a group of smokers of the same age. Unlike Ruff et al. (1971), we did not find a consistent relationship between hypoxaemia and closing capacity.     

Coliform inhibition by bacteriocin-like substances in drinking water distribution systems

Bacterial isolates from an unchlorinated potable groundwater system and a chlorinated surface water system were screened by an agar overlay method for the ability to produce bacteriocin-like substances (BLS) inhibitory to the growth of Escherichia coli, Klebsiella sp., and Enterobacter aerogenes. The production of coliform-specific BLS by noncoliform bacteria varied with the site and date of isolation as well as the genus of the producer strain. A total of 448 bacterial isolates were screened from the chlorinated system, and 22.1% produced BLS specific for at least one of the three coliforms. In the unchlorinated system, 7.9% (n = 696) possessed this ability. Flavobacterium/Moraxella comprised 57.1% of all bacteria (from both systems) producing BLS. The possibility that BLS interfere with coliform detection in standard bacteriological water quality tests is discussed.     

IgA class reticulin antibodies in relatives of patients with coeliac disease

IgA class reticulin antibodies were not found in patients with Crohn's disease, ulcerative colitis, and hiatus hernia despite a significant incidence of IgG class reticulin antibodies. None of 56 normal healthy subjects was positive. In contrast, 13 (76%) of the sera from 17 patients with coeliac disease on normal diet were positive for IgA class antibodies as were 19 (20%) of 93 first degree relatives. Seventy-three relatives underwent jejunal biopsy. Grade III (flat) histology was found in 13 and, of these patients, 10 (77%) showed IgA class reticulin antibody in their serum. It is suggested that determination of IgA class reticulin antibodies was a useful test to determine which relative must be biopsied.     

Synthesis and subcellular location of peroxisomal membrane proteins in a peroxisome-deficient mutant of the yeast Hansenula polymorpha

We have studied the synthesis and subcellular location of peroxisomal membrane proteins (PMPs) in cells of a peroxisome-deficient (per) mutant of the methylotrophic yeast Hansenula polymorpha. Western blot analysis of methanol-induced cells of the per mutant, which had been growing in a continuous culture on a glucose/methanol mixture, indicated that various PMPs were normally synthesized. As in wild type (WT) cells, the levels of PMP synthesis appeared to be dependent on specific cultivation conditions, e.g. the carbon source used for growth. In contrast to WT controls, PMPs in methanol-induced per mutants were not subject to proteolytic degradation. Biochemical and immuno(cyto)chemical studies suggested that the PMPs in methanol-induced per cells were located in small proteinaceous aggregates, separated from peroxisomal matrix proteins that were also present in the cytosol. Vesicular membranous structures, resembling the morphology of intact peroxisomes, were never detected irrespective of the growth conditions employed.