摘要:

The engulfment rates of a series of mutants derived fromS. typhimurium395 MS were followed by exposing heat‐killed,51Cr‐labelled bacteria to rabbit peritoneal polymorpho‐nuclear leucocytes (PMN). The mutants studied possess different lengths of lipopoly‐saccharide (LPS) chains on their surface. Phagocytosis was generally more rapid for mutants with phage patterns typical of shorter LPS chain lengths but, as in the case of virulence, the presence of O‐specific LPS on the cell surface overshadowed the effect of chemotype. The roughest mutant, which possesses the shortest chain and is most liable to phagocytosis, was attached by simple contact between bacterial and phagocyte surfaces; serum was of minimal importance. In contrast, engulfment of bacteria with O‐specific LPS was considerably enhanced by heat‐labile serum factors, probably those of the complement system. The susceptibility of rough mutants to phagocytosis is discussed in terms of the interaction of hydrophobic groups on the bacterial and phagocyte surface leading to cell‐to‐cell adhesion and ev

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00169.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The response of neutralizing and vibriocidal antibodies was studied in rabbits which were immunized with varied doses of aV. choleraeculture filtrate material (IA) containing exotoxin and endotoxin at a ratio of 1:100. Optimal formation of neutralizing as well as vibriocidal antibodies after a single sobcutaneous injection of IA was noted when a dose of IA containing 12.5 μg exotoxin and 1.25 mg of endotoxin was employed. Irrespective of antigen dose the neutralizing antibodies were almost exclusively of the IgG class. Vibriocidal antibodies were of the IgG as well as IgM type, the IgG/IgM ratio increasing with rising antigen dose. Revaccination with identical doses four months later resulted in markedly increased titres of neutralizing antibody, IgG, as compared to the response after the first injection. The response of vibriocidal antibodies after the secondary injection was dose‐dependant. Higher antibody titres than in the primary response were noted with low antigen doses. With high doses the titres were similar after the two injections but the maximum level was reached earlier than after the primary injection. In addition, after the secondary injection a higher proportion of IgG antibodies was not

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00170.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A new pneumococcus type, 47 A, has been established, bringing the number of known types up to 83. The new type is closely related to type 47 (now called 47 F) and the two types form group 47. Type 47 A has an antigen in common with type 43.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00171.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Rabbit anti rat lymphocyte sera (ALS) were produced in rabbits treated with azathioprine during the immunization period. Such antisera were cytotoxic to lymphocytes with nearly as high litres as have been seen in untreated animals using the same immunization schedule. Treatment of the antisera with 2‐mercaptoethanol followed by alkylation, resulted in marked loss in titre towards lymphocytes. Separation on Sephadex G‐200 confirmed that most of the cytotoxic activity was to be found among the IgM antibodies. Both “thymus‐azathioprine” and “spleen‐azathioprine” ALS significantly prolonged the survival of skin allografts in rats. Thymus antisera were more efficient than spleen antisera. Reduction and alkylation of active thymus antisera resulted in loss of in vivo immunosup

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00172.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A procedure for the control of disinfectant inactivators is described and suitable antagonists for some disinfectants are listed.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00173.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Drug resistance was studied in Gram negative bacteria isolated from urine specimens. About 2/3 of the strains were resistant to one or more of the antibiotics under study (ampicillin, chloramphenicol, nalidixic acid, streptomycin, sulphonamide and tetracycline).Escherichia coliandProteusdominated among the bacteria isolated. Multiple resistance was common, tetracycline resistance being the most common resistance trait. Out of 286 drug resistant strains 26 per cent were found to carry R‐factors that could be transferred to theE. coliK‐12 strain used as recipient. Also among the R‐factors, tetracycline resistance was the most common resistance. R‐factors carrying as much as 5 resistance traits were found. The frequency of R‐factors among patients from different wards and in different age groups were found to be quit

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00174.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The effects of mitocycin C on growth and cell size in shake flask cultures of P‐388 mouse cells have been investigated. Concentrations of the antibiotic in the range 0.01 to 1.0 μg/ml progressively inhibited cell growth. With 0.5 μg/ml of mitomycin C, cell multiplication stopped after 1 day and an increasing fraction of the cells were dying, reaching 20 per cent after 3 days' treatment. At least 50 per cent of the cell population grew into giant cells. Exposure for 1 hour to 0.5 μg/ml of the antibiotic caused a slight inhibition of cell multiplication and a significant increase in giant cell formation after 1 day. Upon further incubation these effects were overcome. Increased mean cell size was also found 1 day after this treatment, followed by a return to a normal cell size distribu

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00175.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Seventy‐one strains ofStaphylococcus aureusisolated from the nasal cavities of healthy swine were studied biochemically, serologically and by phage typing. Sixty‐nine strains (97 per cent) were typable by phages of the International Basic Set, 55 strains at RTD and 14 strains at RTD × 1,000, whereas only 30 strains were lysed by “bovine” phages from the provisional set (Davidson's set). Sixty‐six strains (93 per cent) were typable with factor sera. The agglutinations were strong and usually only one type agglutinogen was present. Fifty strains formed a homogeneous group with biological properties considered as characteristic of staphylococci occurring in swine. These strains were of crystal violet type A, fibrinolysin‐negative, produced β‐haemolysin and pigment, coagulated human plasma strongly but not bovine plasma. They belonged to phage group II and had th

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00176.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Two to three gel‐precipitating (GP) antigens of rubella virus were extracted from purified rubella virus by treatment with the nonionic detergents Nonidet P40 and Tween 20. The strongest of these GP antigens was further characterized. This antigen sedimented through a 5–20 per cent sucrose gradient in an ultracentrifuge at an S value of about 3.5. It banded in a CsCl equilibrium gradient at densities of 1.25 to 1.30 g/ml. An identical small‐sized antigen could be extracted from rubella‐infected BHK‐21 cells. This antigen seemed to be part of the rubella virus envelope. Some characteristics of the remaining core particles were d

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00177.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

A gel‐precipitating (GP) antigen was purified from rubella‐infected BHK‐21 cells. The purification procedure included DEAE‐cellulose chromatography and ultracentrifugations. The purified antigen also had CF antigen activity which represented about 10 per cent of the original amount of CF antigen in infected BHK‐cells. This GP antigen sedimented at about 3.5 S in sucrose gradient centrifugations and equilibrated at about 1.30 g/ml in CsCl gradient centrifugations. Immunization of guinea pigs with this antigen resulted in the production of rubella GP antibodies as well as HI and CF antibodies to purified rubella virus. The gel precipitating antibody response was measured with this purified antigen. After natural rubella infection a slow increase in GP titres was found until the end of the observation period which covered 3 to 4 months. A tendency to slow development of rubella GP antibodies was observed in rubella vaccinees. Animal immunizations confirmed the slow increase of GP antibodies. Rabbits responded better than guinea pigs when measured by GP, although the latter produced high rubella HI antibo

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00178.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY