摘要:

SummaryIn a model system, consistent transfection of chick embryo fibroblasts (CEF) by DNA from the XC cell line occurred, with recovery of infections Rous sarcoma virus. The techniques were then applied in attempts to recover possible human humour viruses. Even with various modifications of the XC technique, DNA from three human malignant melanoma cell lines failed to infect adult or foetal human fibroblasts, although melanoma DNA was taken up into nuclei of target cells. XC DNA did not transfect human foetal fibroblasts and melanoma DNA was ineffective in CEF. DNA from the Raji (Epstein‐Barr virus non‐producer) and QIMR‐WIL (producer) lymphoblastoid cell lines applicable techniques therefore failed to recover EB virus the putative melanoma retrovirus, or other potential tumour virus.

ISSN:0004-945X    

DOI:10.1038/icb.1979.1

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe course of the disease, cutaneous leishmaniasis, caused by the intracellular protozoan parasiteLeishmania tropica, differs markedly amongst various common inbred mouse strains. After intradermal injection of 1 × 106promastigotes to young female specific pathogen‐free (SPF) derived mice, persistent infection characterized by an expanding ulcerous lesion is seen in BALB/c and DBA/2 mice. In the strains CBA/H, C3H/He and A/J, lesions resolve within 8 weeks, and in C57Bl/6 mice no real lesion typical of cutaneous leishmaniasis develops at the injection site. NZB mice are highly resistant. Macrophages harvested from the thioglycollate‐stimulated peritoneal cavity of NZB and C57Bl/6 mice appear to differ from macrophages of the other mouse strains in not supporting multiplication ofL. tropicaorganismsin vitro. Nevertheless, hypothymic nude (nu/nu) mice of C57B1/6 genotype, as well as CBA/H‐nu/nu and BALB/c‐nu/nu mice, develop large lesions with metastases to other cutaneous and visceral locations. In the intact mice in which infection resolves spontaneously, resistance to reinfection is complete. Using mouse antipromastigote sera and an indirect fluorescent antibody test in carefully controlled experiments, L. tropica antigens were detected on in vitro infected macrophages of both highly susceptible BALB/c and relatively resistant CBA/H genotypes. After incubation with a crude soluble antigen preparation from cultured promastigotes, infected macrophages of both genotypes) in being unable to sensitize syngeneic recipients for a delayed‐type hypersensitivity response to that antigen. When infected and uninfected macrophages were used as “blocking cell” in anin vitroalloreactive cytotoxic T cell system involving cells from congenic mice, evidence was obtained for reduced H‐2dexpression on infected macrophages of the susceptible mouse strain, BALB/c. The data in this model system of cutaneous leishmaniasis raise the possibility that genetic susceptibility is associated with both a permissive macrophage and defective T cell recognition of parasite antigens on infected macrophage. Defective recognition may be the result of reduced functional expression of H‐2dantigens on infected BALB/c macrophages required for efficient recognition by syngeneic T cells of one or more sub‐populations.

ISSN:0004-945X    

DOI:10.1038/icb.1979.2

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryTopsoil herbage and faces collected during an outbreak of ryegrass staggers in sheep were examined for tremorgenic peniecllia. No such fungi were recovered from the plant material, but they were found among the predominant fungi in the soil and faecal samples. The commonest species ofPenicilliumand almost the only tremorgenic species encountered, wasPenicillium JanthinellumBiourge. When fed to sheep, the mycelium of this fungus evoked a number of the clinical signs seen in field eases of ryegrass staggers. Two tremorgenic toxins were isolated from the mycelial felts and available evidence indicates that they are verruculogen and funitremorgin A. P. janthinethum also produced these tremorgens when from this study are in accord with the hypothesis that ryegrass staggers is caused by tremorgenic mycotoxins.

ISSN:0004-945X    

DOI:10.1038/icb.1979.3

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThis paper describes a method, using an interactive computer programme, for fitting a curve to data which is expected to assume a sigmoid form. The programme is specifically designed to generate best estimates of the limits and maximum slope of stimulus‐response curves for the carotid sinus baroreceptor reflex, but is applicable to curve‐fitting tasks in other fields such as immunology, pharmacology, biochemistry and neurophysiology.

ISSN:0004-945X    

DOI:10.1038/icb.1979.4

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe western grey kangaroo (Macropus fuliginosus) was found to be deficient for galactose‐1 phosphate uridyl transferase (GPUT). This species could be used therefore for studies of gene therapy techniques. An improved GPUT assay procedure was developed. It was found that phage particles injected intravenously remain in the blood of kangaroos until the particles are removed by the reticuloendothelial system or, if this system is overloaded, the particles are inactivated by the immune system four days later. No effective transgenosis was detected of the bacterial gal operon contained in the phage used.

ISSN:0004-945X    

DOI:10.1038/icb.1979.5

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryProtein binding of urate may have some pertinence to the pathogenesis of goat. However, binding studies have been hampered by problems within vitromethodology and by the problem of relating the results ofin vitrostudies to the physiological situation.In the present study urate binding was determined by an ultrafiltration procedure. All manipulations were performed anaerobically and at 37° in order to maintain the sample under physiological conditions.Normal urate bound was 15 ± 7·5% in males and 10 ± 6·67 in females. Urate binding did not correlate significantly with either the albomuin or total urate concentration. It is suggested that the interaction between protein and urate is influenced by a number of factors other than the concentrations of free urate and binding protein. Some possible ones are discussed.The techniques described might usefully be applied to a study of urate binding in various pathological states.

ISSN:0004-945X    

DOI:10.1038/icb.1979.6

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryAre‐evaluation was made of the efficiency with which some of the commonly used assays would detect intestinal antibodies are the baby mouse protection test and the radioimmunoassay. The reasons for the lack of sensitivity with other assay methods are discussed.

ISSN:0004-945X    

DOI:10.1038/icb.1979.7

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe immune response of the mouse to priming and booster doses ofV. choleraewas studied to establish whether serum antibody could be used as a correlate of local immunity, Serum antibody titres following oral boosting immunity. This was not the ease when the same oral booster dose was given to parenterally‐primed animals. These results were discussed in relation to the human endemic situation. The highest titres of intestinal protective antibodies were found following combination of the oral and parenteral routes of immunization. Various killed or extracted preparations ofV. choleraewere used as oral vaccines to test their ability to induce protective antibodies in the gut. Only Boivin antigen was capable of inducing as good an intestinal antibody response as would the living organism.

ISSN:0004-945X    

DOI:10.1038/icb.1979.8

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryA macrophage migration inhibition lest showed that the blood lymphocytes of 15 of 27 sheep inoculatedin uteroor al birth with disrupted cells from ovine malignant lymphomas responded in culture to antigens derived from three other lymphomas. A close association was seen between animals whose lymphocytes were antigen‐sensitive and those which developed lymphocytosis. This association and the specificity of reaction between the various tumour antigens employed in the tests is interpreted as further evidence toward a viral aetiology in ovine malignant lymphoma.

ISSN:0004-945X    

DOI:10.1038/icb.1979.9

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryA radioimmnunoassay for the measurement of immunoreactive secretin has been developed. The assay is specific and sensitive so that 2·8 fmol/ml can be measured. Basal secretin levels inn man are generally undetectable and a protein‐rich meal does not elicit a secretin reponse. However, the intraduodenal instillation of HCl leads to a prompt rise in circulating immunoreactive secretin and exogenous secretin administered intravenously is easily and accurately measured.

ISSN:0004-945X    

DOI:10.1038/icb.1979.10

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY