摘要:

SummaryThe proliferative responses of rat peripheral blood lymphocytes (PBL) and spleen tells to phytohemagglutinin (PHA) were studied after single or multiple (daily for 4 days) injections of azathioprine (AZ). Lymphopenia developed within 4 h of a single dose (78 mg/kg) of AZ and persisted for at least 72 h. There was no lymphopenia 24 h after the last of 4 daily injection.In vitro. PBL were more sensitive than spleen cells to the inhibitory effect of AZ. Likewise, the responses of PBL were relatively more depressed than those of spleen cells after single or multiple injections of AZ. The degree of depression was less than was expected from the effect of AZin vitro. Multiple small doses were more depressive than multiple large closes. Serum from treated rats used at 20% concentration, was more depressive than normal. Thus, rat Lymphocytes are quite sensitive to AZin vitro, but appear to be relatively resistantin vivo, this resistance resembling the resistance of the primary antibody response to AZ treatment.

ISSN:0004-945X    

DOI:10.1038/icb.1979.12

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe supernatant from Con A‐activated spleen cells (CS) can be used to generate homogeneous populations of alloreactive T cellsin vitro. Subculture of activated cells in CS containing medium is required for the continued proliferation and expression of effector activity. Prolonged Subculture in CS containing medium does not result in indefinite growth and proliferation of alloreactive T cells. The activity in CS required to maintain cytotoxic cell growth is not species specific, and is therefore separable from the costimulator activity in CS required for the initiation of the T cell response to alloantigen; this latter activity is species specific.

ISSN:0004-945X    

DOI:10.1038/icb.1979.13

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryDuring a four and a half year period a group of cattle was grazed continuously with a group of sheep and observed forToxoplasmaantibodies. Initially, there were 25 cattle and 31 sheep, but these were reduced to 19 and 18, respectively, by the end of the observation.Only transient antibody responses were noted in 2 cattle, whereas persistent titres developed in 12 sheep. Interpreted in the light of available information, these results were taken to indicate that cattle do not readily acquire persistentT. gondiiinfections.

ISSN:0004-945X    

DOI:10.1038/icb.1979.14

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe turnover rate and pool volume of radiolabelled autologous IgG1was similar to homologous IgG1in adult sheep. In neonatal lambs there was no significant difference for either of these parameters between homologous serum IgG1and maternal colostrum IgG1. However, the pool volume for IgG1expanded by approx. 30% over the experimental period in the lambs. When the turnover rates were corrected for this increase they were found to be similar to those observed for IgG1in adult animals.

ISSN:0004-945X    

DOI:10.1038/icb.1979.15

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe effect of a 4% albumin diet initiated at weaning on the susceptibility to influenza virus infection was studied in C57B1 mice. Protein‐deprivation was found to enhance markedly the susceptibility to a lethal infection with both mouse‐virulent and avirulent strains of virus. Viraemia was observed more frequently in protein‐deprived mice, and virus persisted longer in the lungs. The humoral immune response following intranasal infection was depressed, with normal levels of IgG antibody but reduced levels of IgM antibody. No difference was found in the seroconversion frequencies between well‐nourished and protein‐deprived mice. Pre‐immunization did not affect the virus titres in the lungs of protein‐deprived mice after challenge with the homologous virus, nor did it prevent the spread of virus to the thymus and brain. The results were discussed in terms of the immunocompetence of the malnourished host and of the potential risk of epidemic influenza in children suffering from severe forms of protein‐energy malnutrition.

ISSN:0004-945X    

DOI:10.1038/icb.1979.16

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryIn seven human melanoma cell lines and one human fibroblast strain some correlation of resistance to cell killing was found with two bifunctional alkylating agents (melphalan, chlorambucil) and three monofuctional agents (4(5)‐(3.3‐dimelhyl‐1‐triazeno) imidazole‐5(4)‐carboxamide (DTIC), methylmethane sulphonate (MMS) and N‐methyl‐N1nitro‐N‐nitrosoguanidine (MNNG), but little cross‐resistance was found between these two groups of agents or with cytosine arabinoside (ara‐C). In contrast to previous studies with rodent tumours, potentially synergistic (chloroquine, arginine) or antagonistic (ascorbic acid, leucine) compounds did not affect the toxicity of melphalan in a human melanoma cell line. In two melanoma lines DTIC induced patterns of DNA damage (inhibition of semi‐conservative synthesis) and repair (strand breaks and repair synthesis) similar to, but not identical with, those induced by the methylating agent MNNG. These results suggest that a methylating species is derived from DTIC but has a different reactivity toward DNA compared with MNNG.

ISSN:0004-945X    

DOI:10.1038/icb.1979.17

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe hypothesis that the prior intake of barbiturates may predispose patients to form increased amounts of oxalate following the intravenous infusion of xylitol was investigated in the rat. Phenobarbitone pre‐treatment resulted in a 2–3 fold increase in urinary |14C| oxalate concentration following the intra‐peritoneal injection of |U‐14C| xylitol or |1‐14C| glycollate. The absence of any marked changes in urine volumes and creatinine excretion implied that this increase in urinary oxalate excretion was due to the enhanced synthesis of oxalate. The activities of key enzymes in hepatic oxalate synthesis, glycollate oxidase, lactate dehydrogenase, catalase and alanine aminotransferase were not altered by phenobarbitone pre‐treatment. It is suggested that the increased activity of the microsomal mixed function oxidases, following phenobarbitone treatment, may facilitate the oxidation of glycollate and possibly xylitol. This communication lends experimental support to the concept that the prior intake of drugs, such as barbiturates, may predispose patients to form increased amounts of oxalate.

ISSN:0004-945X    

DOI:10.1038/icb.1979.18

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryA serological survey for antibodies toLeptospira interrogansserovarhardjowas conducted on 574 serum samples from 10 native and 4 introduced wildlife species in south‐eastern Australia. The microscopic agglutination (MA) test was used, and titres tohardjoantigen were detected in 33.5% of 352 brush‐tailed possums (Trichosurus vulpecula) sampled in several areas of Victoria. Prevalence of reactors ranged from 14 to 66% in 4 populations examined intensively, Serovarbalcanicawas isolated from possums withhardjoantibodies from two different areas. Of 20 wombats (Vombatus ursinus) examined in Victoria, antibodies tohardjowere found in sera from 4 and titres to Pyrogenes and Pomona serogroups were detected in another.Hardjoantibodies were demonstrated in sera from 13 of 19 rusa deer (Cervus timorensis). Negative MA test results tohardjoantigens were recorded in 55 mountain possums (T. caninus), 63 macropods (Macropusspp.), 17 water rats (Hydromys chrysogaster), 39 fallow dew (Dama dama), 2 hog deer (Axis porcinus) and 2 water buffalo (Bubalus bubalus). No MA antibodies to any of 16 leptospiral serogroups were detected in 17 water rats tested. Kidneys were examined from 330 of those animals and focal interstitial nephritis suggestive of leptospirosis was found in kidneys of 63 of 169T. vulpecula, 3 of 55T. caninus, 12 of 18V. ursinus, 6 of 22Macropusspp., 9 of 16H. chrysogaster, 5 of 11C. timorensisand 3 of 39D. dama. A statistical association between focal interstitial nephritis and MA antibodies tohardjowas found inT. vulpecula.

ISSN:0004-945X    

DOI:10.1038/icb.1979.19

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe microscopic agglutination (MA) test was utilised to study the prevalence of antibodies toLeptospira interrogansserovarhardjoin 4 populations of brush‐tailed possums (Trichosurus vulpecula). The overall antibody prevalence varied from 14% to 66%; however, the age distribution of MA test titres was remarkably similar in all 4 populations. Antibody prevalence was similar in both males and females and demonstrable antibodies wore limited to sexually mature animals. The greater prevalence of high titres (≥ 1:128) in the 18‐ to 24‐month age group suggested that primary infections were acquired at this age. The findings suggested that infection was maintained in possum populations by direct transmission, probably associated with breeding. Focal interstitial nephritis was observed in kidneys of possums greater than 18 months of age and was associated with MA titres tohardjo(P<0.001). Serovarbalcanicawas isolated from possum kidneys from 2 of these populations, suggesting thatbalcanicainfections were responsible for most of thehardjotitres. However, agglutinin‐absorption tests indicated that some possums may be infected with a leptospire more closely related tohardjothan tobalcanica.

ISSN:0004-945X    

DOI:10.1038/icb.1979.20

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY

摘要:

SummaryThe effectiveness of transmission from noradrenergic nerves supplying the guinea‐pig ileum was evaluated in normal preparations and in preparations taken from animals injected 18 h to 4 days previously with antiserum to dopamine β‐hydroxylase. Degeneration of the nerves following the antiserum was monitored histochemically in the same preparations.A decline in the effectiveness of transmission, which paralleled the degeneration of the nerves, was observed. The earliest effects were detected at 18 h and the greatest effect was found at 2–4 days following the administration of antiserum. Binding of the antibodies has been detected as early as 6 h after injection. It is therefore concluded that binding of the antibodies to the nerves,per se, does not significantly compromise transmission, nod that histochemical evidence of degeneration can be used to indicate the onset of functional deterioration of noradrenergic nerves following their exposure to antibodies to dopamine β‐hydroxylase.

ISSN:0004-945X    

DOI:10.1038/icb.1979.21

出版商:Nature Publishing Group    

年代:1979

数据来源: WILEY