摘要:

T cells fail to recognize free antigenic determinants. What the T‐cell receptor recognizes is a complex consisting of a peptide fragment cleaved from antigen and self‐MHC structures on the surface of antigen‐presenting cells. While extensively investigated with protein antigens, only limited information is available on the capability of T cells to recognize carbohydrate antigens in a specific way. Therefore, we have investigated the specificity of human T‐cell lines and clones reactive to streptococcal A (Strep A) vaccine. It was found that neither soluble streptococcal A carbohydrate (A‐CHO) nor synthetic oligosaccharides deduced from bacterial carbohydrates could stimulate Strep A‐reactive T cells, although A‐CHO stimulates specific antibody production in B cells very effectively. In conclusion, Strep A‐specific T cells seem to recognize other structures of the bacterial vaccine than A‐CHO. This was confirmed by retained stimulation after removal of carbohydrate epitopes by periodate treatment. Such Strep A‐reactive T cells are frequently (>10−3) found in CD4+T cells of healthy donors. Implications of this finding with regard to anti‐carbohydrate immune

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00994.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The effect of increasing amounts of cholesterol on the morphology of the liposomes constituting the VDRL‐antigen was studied. The morphological parameters examined were the shape of the lipoidal particles and especially the number of lamellae on each particle in the various mixtures of lipids studied. Cholesterol in the presence of cardiolipin and lecithin is observed as rhomboid crystals, indicating that the majority of the cholesterol is located exterior to the lamellar membranes of lecithin and cardiolipin. It is shown that the effect of cholesterol is to reduce the number of individual lamellae per liposome, mainly by mechanically dispersing the cardiolipin and lecithin on the surface of the cholesterol crystals. It is suggested that cholesterol has no effect on the structure of the epitopes which react with antibodies in sera from patients with syphilis, but that, as a result of the mechanical dispersion of cardiolipin and lecithin, it creates liposomes with more accessible epitope

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00995.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Villitis was studied in placentas from 445 singleton infants from an ethnically homogeneous population with a good socioeconomic standard. There were 161 infants small for gestational age (SGA) and 284 appropriate for gestational age (AGA). Villitis was found in 12 SGA‐placentas (7.5 per cent) and 8 AGA placentas (2.8 per cent) (p<0.05). The degree of villitis was also related to growth retardation (p<0.05). Except for one placenta with villitis due to CMV infection, the cause of villitis could not be determined. No association was found with various studied factors such as hypertension, pre‐eclampsia, smoking or maternal pyrexia during pregna

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00996.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Plasmid profiling was used as an epidemiological tool during a period of frequentSalmonella enteritidisinfection in a hospital.S. enteritidiswas isolated from 22 patients and employees. Isolates from 18 persons harbored one 29 and one 36 megadalton (MDa) plasmid. The 29 MDa plasmid has not been previously described in this species and was not found in 54 control strains ofS. enteritidisfrom other sources. The respective restriction endonuclease digest fragments of the 36 and the 29 MDa plasmids were always identical. This plasmid pattern thus served as a marker for the isolates from the outbreak.

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00997.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Immunization against a lethal dose ofSalmonella typhimuriumwas studied in athymic and thymus‐bearing LEW rats. Active immunization was performed with formalin‐killed whole cell vaccine or sublethal infection prior to the lethal infection. After vaccination with killed bacteria the euthymic animals produced antibodies againstS. typhimurium, but neither the euthymic nor the athymic animals survived the infection. After non‐lethal infection euthymic and thymus‐grafted nude rats were not affected by the second and otherwise lethal bacterial dose, and had high antibody titres. All the athymic nude rats died after the second and lethal bacterial challenge. Passive immunization with plasma from immunized euthymic animals did not protect any of the animals against the lethal bacterial dose. However, all animals survived when treated with large doses of spleen cells from immunized euthymic rats. Both athymic and thymus‐bearing animals treated with primed spleen cells had high antibody titres. The percentages of splenic and lymph node T lymphocytes in primed spleen cell‐treated athymic rats were comparable to those found in euthymic and thymus‐grafted animals. Treatment with primed spleen cells from immunized thymus grafted animals provided only limited protective effect, and treatment with cells from athymic animals had no effect. The study shows that although isogeneic thymus‐grafted nude rats become resistent to reinfection withS. typhimurium, only large doses of spleen cells from immunized euthymic animals can be used for passive trans

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00998.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Data on all cancers among children born 1973–1984 were extracted from the Swedish Cancer Registry and linked to data in the Medical Birth Registry (1,268 cancer cases). For each case, two controls were selected, matched for maternal age, parity, county, and month of birth. A marginally increased risk of childhood malignancy was seen in the offspring of teenage mothers and at parity 1 and 4+. There was an excess among cases of the diagnosis physiological icterus. No statistically significant associations were found between childhood malignancy and infant sex, twinning, birthweight, non‐chromosomal malformations, maternal smoking, or complications during pregna

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb00999.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Using a microagglutination method, domestic and wild animal sera, together with human patient and healthy blood donor sera, have been analysed for titres against variousLegionellaspecies, comprising fourteen different serogroups. Generally, the level of moderately elevated titres, i.e. ≥ 64, was low for all the aforementioned serum groups. Within the domesticated animals, cattle, pigs and dogs presented a much lower prevalence in Kenya than found elsewhere, whereas it was the other way round for goats. Human sera, either from patients or from healthy donors, did not react againstL. pneumophilaserogroups 1, 6, or 3, which in that sequence are the most commonL. pneumophilaserogroups in Europe, and in other geographic areas where legionellosis is common. High titres of ≥ 256 againstL. pneumophilaserogroup 6 (two cattle) or againstL. bozemaniistrain Mi‐15 (two cattle, one dog) indicate that although the epidemiological picture may be different from other parts of the world,Legionellainfections exist in Kenya as

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb01000.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A study of carriage ofHaemophilus influenzaetype b (Hib) and non b in Danish day‐care facilities, employing a highly selective medium supplemented with three antibiotics and direct detection of the type b capsular antigen by latex‐agglutination and coagglutination, was carried out. Of 329 children, 217 (66%) were found to be carriers ofHaemophilus influenzae.Among 64 children from day‐care centers in which a case of invasive Hib infection had occurred, four carriers of type b were found, whereas no type b carriers were identified among 265 children from unexposed day‐care centers (p<0.003). Of 217 isolated strains, seven (3.2%) were found to have lowered susceptibility to ampicillin, two (0.9%) to chloramphenicol, two (0.9%) to cefuroxim, and one (0.5%) to ce

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb01001.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In assays to determine adherence ofYersinia enterocolitica, virulence plasmid‐containing (pYV+) strains and strains of their plasmid‐cured (pYV−) derivatives adhered equally efficiently to HeLa cells and fetal intestinal epithelial INT 407 cells. Non‐pathogenic strains ofY. enterocoliticadid not adhere. In contrast, pYV+strains adhered more efficiently to rabbit and human intestine than did pYV−‐strains, as evaluated by anin vitroassay, measuring adhesion of radiolabeled bacteria to disks of intestinal tissue. Thus, even if pathogenic strains ofY. enterocoliticaare able to adhere to cultured epithelial cell lines and intestinal tissue by means of chromosome‐encoded properties alone, properties encoded by the pYV plasmid significantly enhance and contribute to adhesion to inte

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb01002.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The aim of this study was to investigate the relationship between physical nuclear volume and ploidy level in malignant melanomas, and to analyse the heterogeneity of these two parameters among primary and corresponding secondary tumours. Unbiased stereological estimates of nuclear volume can be obtained objectively by point‐sampled intercepts. Using this approach, the volume‐weighted mean nuclear volume, nuclear v̄v, was estimated in ordinary histological sections from 34 primary cutaneous malignant melanomas and their corresponding 62 metastatic lesions. For comparison, DNA‐indices (DI) were determined by flow cytometry in adjacent sections from the same paraffin‐embedded tumours. Only a poor correlation was found between nuclear v̄vand DI (Kendall's τ=+0.21). The variability of nuclear v̄vamong metastatic lesions was increased as compared to primary melanomas, whereas averaged mean values of nuclear v̄vdid not differ significantly between the two types of neoplasms. Aneuploidy was not significantly associated with increased nuclear v̄v. Pronounced intra‐patient heterogeneity of nuclear v̄vwas disclosed among metastases and between the primary melanoma and the metastatic lesions. Likewise, no significant association between DI of primary and metastatic melanomas was demonstrated. Heterogeneity of nuclear v̄vand DI in malignant melanomas is in agreement with the theory

ISSN:0903-4641    

DOI:10.1111/j.1699-0463.1990.tb01003.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY