摘要:

SUMMARY3‐Isobutyl‐1‐methyl‐6‐thioxanthine (M&B 5924), when given intravenously in a dose of 1·0 mg./Kg. to anaesthetized, but otherwise intact dogs, gave statistically significant increases in respiratory rate, respiratory volume, oxygen consumption, carbon‐dioxide production and pulse rate. Femoral and pulmonary arterial pressures decreased, as did the calculated total peripheral resistance.Coronary blood flow and cardiac metabolic rates for oxygen and carbon dioxide increased. Cardiac efficiency and coronary vascular resistance decreased.

ISSN:0004-945X    

DOI:10.1038/icb.1962.38

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYNormal rat aorta has been examined under the electron microscope. Elastic laminae of the media are relatively smooth on the surfaces adjacent to endothelium or adventitia but highly branched and irregular on the surfaces adjoining muscle cells. In suitably stained preparations, the vesicular character of elastin may be seen. The smooth muscle cells of aortic media differ from those in other organs in their cytoplasmic constituents and in their relations to one another. They attach to neighbouring elastic laminae by morphologically characteristic devices but have no such attachment to adjoining muscle cells. The connective tissue spaces among cells contain many collagen fibrils and fragments of elastin. The endothelium rests on a narrow connective tissue space containing fine fibrils and has no basement membrane. Otherwise it resembles endothelium in smaller vessels. The adventitia is composed chiefly of large collagen fibres interspersed with a few capillaries and fibroblasts.

ISSN:0004-945X    

DOI:10.1038/icb.1962.39

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYElectron microscopic study of lathyrous aorta has confirmed and extended earlier reports of increased collagen and intercellular substance in the aortic wall. This substance appears to coat elastic laminae and to project between the cells. The anatomical relations of muscle cells and elastic fibre are disrupted and changes in collagen fibrils characteristic of lathyrism are commonly seen. Changes described in the muscle cells are interpreted as being consistent with a high level of secretory activity in the early stages, but later they more resemble a degenerative change.

ISSN:0004-945X    

DOI:10.1038/icb.1962.40

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYTwo samples of heart muscle from copper‐deficient pigs and a control sample from a normal pig were analysed for haemaand protohaem content firstly by spectrophotometric determination of the mixture of the two haemochromes and secondly by separation of the two free porphyrins by fractional extraction from ether by hydrochloric acid.The haemacontent was found greatly decreased in copper‐deficiency. The low haemacontent could be due either to a rôle of copper in haemasynthesis (as distinct from the synthesis of the whole enzyme) or to a rôle of copper in the biosynthesis of the holoenzyme at an early stage. It appears possible to ascribe the loss of activity of cytochrome oxidase in copper‐deficiency entirely to this factor and this loss therefore cannot prove that copper is necessary for cytochrome oxidase activity, although it does not exclude this possibility.

ISSN:0004-945X    

DOI:10.1038/icb.1962.41

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe development of lymphoid tissue in the bursa of Fabricius in the chicken has been prevented by the injectionin ovoof testosterone propionate. A small proportion of the hatched chickens were also shown to have a complete atrophy of the thymic cortex.The immunological responses of these hormonally‐treated chickens have been studied using several types of antigenic challenge.In birds deprived of all bursal lymphoid tissue, but still possessing a normal thymus, no circulating antibody was detected after challenge with five classical antigens. Delayed hypersensitivity reactions to tuberculin or vaccinia virus were nearly completely inhibited. However, the rejection time of random skin homografts, and the production of lesions on the CAM by the blood cells of these birds were completely normal.In birds showing a complete atrophy of the thymic cortex as well as of bursal lymphoid tissue, the rejection of skin homografts was also prevented, although the production of CAM lesions by blood cells was still normal.It was concluded that in the chicken there are two and possibly three primary levels of lympbocytopoiesis, each controlling populations of cells concerned with different types of immunological response.

ISSN:0004-945X    

DOI:10.1038/icb.1962.42

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYSerological evidence of ornithosis was found in 56 p.c. of 57 feral pigeons (Columba livia) trapped at Ipswich, Queensland.Virus strains isolated in mice from four of eleven pools of pigeon organs were identified as members of the psittacosis‐lymphogranuloma group by complement‐fixation tests and are considered to be strains of ornithosis virus. Inclusion bodies could not be demonstrated in mice following intraperitoneal injection of the virus, but were readily demonstrated following its intracerebral inoculdation.Pigeons at Ipswich provide a reservoir of ornithosis virus and a potential source of human infection.

ISSN:0004-945X    

DOI:10.1038/icb.1962.43

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe incidence of megacolon has been studied in an inbred strain of mice (NZY) and in the descendants of NZY mice outcrossed to two other inbred strains (NZC, NZB) and to a fertile pituitary dwarf.The results of this study indicate that megacolon is an inheritable disease associated with “piebald” and that it is transmitted by both males and females.The presenting signs and the appearance of the large intestine in affected animals are described together with the features in the enteric plexus which are characteristic of the disease in mice. Attention is drawn to the presence of aganglionic and hypoganglionic segments of gut and the possibility that the length of the aganglionic segment influences the time of onset of megacolon is discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1962.44

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYA method of extracting and identifying the individual iodine‐containing amino acids in plasma is described. It makes use of an anion exchange resin (Dowex 1) for the extraction of the iodinated compounds, paper chromatography for their separation and the application of the ceric sulphate‐arsenious acid reaction for their detection on the chromatogram. The method makes possible the chemical detection of 0·5 μg./100 ml. of diiodotyrosine (DIT) and 0·5 μg./100 ml. of thyroxine (T4) in 6 ml. of plasma. No evidence of decomposition of T4 or T3, either radioactively labelled or not, was found during the procedure. The behaviour of related iodine‐containing amino acids and other compounds such as chloride and thiouracil derivatives were also investigated.

ISSN:0004-945X    

DOI:10.1038/icb.1962.45

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe specificity of the Zimmermann reaction has been investigated using a range of substituted 17‐oxosteroids. It has been shown that 16‐halogenated 17‐oxosteroids give the reaction but that an alkyl or a hydroxyl group at position 16 prevents the reaction, as also does unsaturation in thedring of the steroid. During the reaction with 16‐halogenated 17‐oxosteroids halogen is eliminated. The Zimmermann compounds from a number of steroids have been isolated and partly purified. From spectroscopic studies it is suggested that structures (II) and (IV) below represent the ionised and unionised compounds respectively.

ISSN:0004-945X    

DOI:10.1038/icb.1962.46

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY

摘要:

SUMMARYThe toxic factor of the venom ofEnhydrina schistosahas been isolated by dialysis and column chromatography. The results demonstrate that the lecithinase activity of the whole venom is not associated with the toxic fraction.Antiserum to the toxic factor will neutralise the toxicity of large doses of the whole venom.

ISSN:0004-945X    

DOI:10.1038/icb.1962.47

出版商:Nature Publishing Group    

年代:1962

数据来源: WILEY