ISSN:0004-945X    

DOI:10.1038/icb.1977.1

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryThe soluble surface proteins isolated by Cross (1975) fromTrypanosoma bruceiare compared to those which occur onParamecium aurelia. Calculations based on the amino acid residue data and the molecular weights of these surface antigens indicate that there is a considerable degree of similarity between theT. bruceiand theP. aureliaproteins, and that in neither case can simple mutation be responsible for the differences of molecules within each family of antigens. The analyses are consistent with the suggestion that theP. aureliasystem can serve as a model for the phenomenon of phase transformation (relapse syndrome) which occurs in trypanosomiasis.

ISSN:0004-945X    

DOI:10.1038/icb.1977.2

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryThe effects of the proteolytic enzyme bromelain (Br) on the antigenicity and immunogenicity of sheep and mouse red blood cells (RBC) have been investigated. The results presented support the previous claim that there are antigens present on Br RBC that are not present in an exposed form on untreated RBC and that Br RBC have lost some of the antigens present on the surface of normal RBC. The susceptibility of Br RBC to osmotic lysis was very similar to that of normal RBC. Implying that the modified RBC were not more fragile than normal RBC. Injection of mice with Br mouse‐RBC did not increase the unusually high “background” number of cells producing IgM antibodies against Br mouse‐RBC and mice did not mount delayed‐type hypersensitivity reactions against Br mouse‐RBC, either before or after sensitizing injections of Br mouse‐RBC. However, mouse‐RBC and Br mouse‐RBC elicited similar antibody responses in rabbits and guinea pigs. Although mice appeared unresponsive to Br mouse‐RBC injections, delayed‐type hypersensitivity responses and antibody production in primary and secondary responses were of similar levels irrespective of whether sheep‐BBC or Br sheep‐RBC were used as immunogens.From these studies it appears that mice have B‐cells producing antibodies against the “new” antigens on Br mouse‐RBC. But there are no T‐cells that respond to these antigens by way of “helper” activity in antibody production or by way of cell‐mediated immune reactions.

ISSN:0004-945X    

DOI:10.1038/icb.1977.3

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryLysis of virus‐infected target cells by virus‐specific cytotoxic T cells occurs only where donors of T cells and targets share eitherH‐2KorH‐2Dgenes. The effect of fourH‐2Kmutations on virus‐induced antigens recognized by cytotoxic T cells from anin vitrosecondary response to infection was studied. B10.A(5R) cytotoxic T cells (which share theKend ofH‐2with the mutant strains, except for the mutated gene(s)) efficiently kitted virus‐infected macrophage targets from mutant strains B6‐H‐2bg1and B6‐H‐2bg2, were less effective against B6‐H‐2bhand did not appear to be cytotoxic for B6.C‐H‐2batarget cells. Conversely, B6‐H‐2bg1and B6‐H‐2bg2cytotoxic T cells were more effective in killing virus‐infected B10.A(5R) macrophages than B6‐H‐2bhand B6.C‐H‐2bacytotoxic cells respectively. In addition, B6‐H‐2bg1and B6‐H‐2bg2cells appeared to be only slightly different from wild‐type with respect to the interaction between virus‐infected cells and T cells. The data obtained suggested that virus‐induced antigenic patterns on infected B6.C‐H‐2ba(mutant) cells are more different antigenically from those on wild‐type cells than are those on infected cells from the other mutants, B6‐H‐2bh, B6‐H‐2bg1and B6‐H‐2bg2. This agrees with previous data using primary cytotoxic T cells and thus suggests that no detectable change in the affinity or specificity of cytotoxic T cell receptors occurs between primary and secondary responses to infection. These findings are also discussed in relation to the exclusion of T cells with receptors forH‐2Kdeterminants that are common to the mutants and wild‐type, from the response to virus‐infected self cells.

ISSN:0004-945X    

DOI:10.1038/icb.1977.4

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryThe number of lymphocytes discharged from the mesenteric lymphatic duct was measured over several days of continuous lymph drainage in adult guinea pigs which had been thymectomised at birth or as young adults. The reduced output of lymphocytes during the first few days of lymph drainage from neonatally thymectomised guinea pigs indicated that removal of the thymus at birth produced a deficiency in the mobilizable lymphocyte pool. Adult thymectomy led to a decrease in the moblizable lymphocyte pool which did not become apparent until 35 days after removal of the thymus. This indicated that the production of lymphocytes by the thymus is important in the guinea pig for maintaining adequate numbers of recirculating lymphocytes during adult life.The concentration of lymphocytes was reduced in the peripheral blood of guinea pigs which had been thymectomised at birth. In female guinea pigs this lymphopenia was accompanied by an increase in the number of lymphocytes hearing Kurloff bodies. The concentration of lymphocytes in bone marrow was not significantly altered following neonatal thymectomy.

ISSN:0004-945X    

DOI:10.1038/icb.1977.5

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryChronic protein‐deficiency in weanling mice caused variable suppression of the Immoral and plaque‐forming cell (PFC) responses to sheep erythrocytes. This was most prominent at high antigen doses and did not increase when mice were maintained on the diets for longer periods. Antibody responses produced by deficient mice were often short‐lived and invoked high levels of IgM. Total PFC counts were depressed slightly more than were circulating antibodies. Antibody responses toBrucella abortuswere slightly decreased by protein‐deficiency at high antigen doses hut were normal or elevated at lower doses, the proportion of IgM produced was increased and the splenomegaly response toB. abortuswas severely depressed. These results suggest that the depression of antibody production by protein‐deficiency is not simply due to an impairment of helper T cell function, hut a reduction in the availability or effectiveness of macrophage and regulatory or suppressor T cells may be important.

ISSN:0004-945X    

DOI:10.1038/icb.1977.6

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryRoss River virus strains recovered from north Queensland and the central coast of New South Wales can be clearly discriminated by the use of a short incubation haemagglutination inhibition test. Antigenic homology of strains within these regions and heterology between the regions seem unaffected by time, passage history, adaptation to laboratory mice and the nature of the original source material yielding the strains. It is concluded that the two antigenic types are enzootic to their respective regions and that they have evolved in isolation from a common ancestral virus. A short incubation complement fixation test was found to be more sensitive than the haemagglutination inhibition test in attempts to characterize the virus type inducing convalescent antibody in humans and horses.

ISSN:0004-945X    

DOI:10.1038/icb.1977.7

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY

摘要:

SummaryA sensitive automated assay was developed for the determination of histamine.The endogenous histamine content of intact rabbit thoracic aorta, and of its separated adventitial and medial layers was determined. The histamine content of the intact aorta was found to be only partially sensitive to compound 48/80.The isolated aorta accumulated labelled histamine against a concentration gradient, The uptake was abolished by cooling to 1°, but was unaffected by oxygen lack.The uptake process was sensitive to a variety of agents including extraneuronal catecholamine uptake inhibitors (deoxycorticosterone acetate, normetanephrine) as well as inhibitors of catecholamine and histamine metabolism (tranylcypromine, hydralazine).The uptake was not affected by amodiaquin, a histamine N‐methyl‐transferase inhibitor, by the metabolites 1.4‐methylhistamine or imidazole acetic acid, by compound 48/80 or by the basic amino acid arginine.

ISSN:0004-945X    

DOI:10.1038/icb.1977.8

出版商:Nature Publishing Group    

年代:1977

数据来源: WILEY