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Biomedical subjects

S Ahlstedt

Publications and source records attributed to S Ahlstedt.

At least 163 records · Page 9Linked to original sources
PubMed1980

Allergological examination of cystic fibrosis patients with skin reactions during carbenicillin treatment.

Sixteen of 84 cystic fibrosis patients developed skin manifestations during intensive carbenicillin therapy. The possibility of allergic drug reactions was examined. None of the patients showed any significant levels of antibodies of IgE, IgG or IgM classes against carbenicillin and different penicilloyl determinants as recorded with RAST, sandwich-radioimmunoassay and double antibody assay. The leukocytes of the patients did not release histamine on in vitro provocation with carbenicillin. Furthermore, none of the patients responded to prick test or to peroral penicillin provocation. The negative findings indicated that the recorded reactions were most probably not due to antibody-mediated allergy of type I or type III.

Carbenicillin↗
PubMed1980

Inflammatory potency of antigen-antibody complexes and C-reactive protein in a wound chamber model in rats.

In the present study, the inflammatory potencies of antigens carrying different numbers of determinants, i.e. penicilloyl 5-rat serum albumin and penicilloyl 28-rat serum albumin were compared in a wound chamber model in immunized rats. The results revealed that the antigen with more determinants had a more potent inflammatory effect. The kinetics of the inflammatory responses to the two antigens were similar, however. The inflammation in the chambers was also analyzed against antigen, penicilloyl 26-bovine gamma-globulin and antigen together with the acute phase reactant C-reactive protein of human source (CRP). CRP significantly increased the severity of the inflammation with antigen alone but the kinetics of the responses were similar.

Animals↗
PubMed1980

Cross-reactions between the Tamm-Horsfall glycoprotein and Escherichia coli.

Weak cross-reactions were demonstrated between the Tamm-Horsfall (TH) glycoprotein and antigens in the supernatants of boiled Escherichia coli R1-R4 strains using an inhibitory ELISA system. No cross-reactions could be determined between the purified R1-R4 lipopolysaccharides and the TH protein. Neither could any inhibition be recorded after trypsin treatment, indicating that the cross-reacting substance is protein in nature. The cross-reactions were verified by immunoprecipitation techniques. The biological relevance of the cross-reaction between E. coli and the TH protein particularly as an event inducing the formation of autoantibodies to the TH protein is discussed.

Antigens, Bacterial↗
PubMed1980

Antigenic high molecular weight material in penicillin preparations.

Using a radioimmunoassay, RIA, small amounts of high molecular weight antigens have been reproducibly identified in both biosynthetic and semisynthetic brands of penicillin. These impurities were found to be eliminated by simple chemical means. Measures to avoid this type of contaminants in penicillin preparations should be undertaken because of the immunogenic nature of the contaminants resulting in increased risk of sensitization of patients to penicillin.

Antigens↗
PubMed1980

Antigens in penicillin allergy. V. On the relative allergenic potency of antigens carrying penicilloyl determinants derived from azidocillin, ampicillin and benzylpenicillin.

The effects of the different acyl side chains of azidocillin, ampicillin and benzylpenicillin on the immunogenic potency of penicilloylated antigens as well as on the specificity of the developed antibodies were investigated in CBA mice. The antigens used were penicilloylated bovine gammaglobulin (BGG), bovine serum albumin (BSA) and human serum albumin (HSA). Immunization was performed with injection of high doses of antigens together with adjuvant or by injection of minute amounts of antigen over periods of 10 days. IgE antibodies were recorded with PCA in rats and IgG antibodies were measured with a double antibody assay. The nature of the carrier as well as the number of epitopes was found to influence the development of antibodies irrespective of the immunization schedule used. The immunogenic activity of the PO-BSA antigens was related to the epitope density. The PO-BSA antigens were, in contrast to the PO-BGG antigens, weak immunogens in the CBA mice. The acyl side chains of the different penicillins influenced the induction and specificity of the IgE antibody responses obtained after daily treatment.

Ampicillin↗
PubMed1980

Experimental Escherichia coli 06 infection in mice. 1. Effect of immunisation on resistance in relation to 06 antibody levels in mice of different strains.

The susceptibility to intraperitoneal infection with E. coli 06:k2 bacteria and the increase of resistance after immunization and immune serum injection was analysed in eight mouse strains (CBA, A/J, C3H, C3H/HeJ, C57 B1/6J congenitally athymic C57 B1 nu/nu and their heterozygous nu/+ litter mates as well as NMRI mice). A different susceptibility to the infection was found among the strains. This was not related to endotoxin resistance or thymus deficiency or to the ability of the animals to form antibodies as measured with the enzyme-linked immunosorbent assay, ELISA. Immunization of the animals with 5 x 10(7) E. coli 06:K13 bacteria resulted in a smaller increase in resistance in the less susceptible CBA mice than in the more susceptible A/J or C3H/HeJ mice. This pattern was further accentuated after repeated immunization. The development of resistance by immunization seemed independent of T-cells, since the nu/nu mice were as resistant as the nu/+ mice. The nu/nu mice, however, formed less antibodies after vaccination than did their nu/+ litter mates. The lowest antibody responses were noted in the NMRI mice, but this was accompanied with similar increase in resistance compared with the other strains forming 10-fold more 06 antibodies. Immunization with as little as 102-104 bacteria also resulted in a rise in resistance. This was, however, accompanied by a minute increase in antibody titer. Despite content of minute antibody levels administration of such immune serum gave protection of the recipients. It was concluded that very small amounts of antibodies would provide protection against E. coli infection varying from one mouse strain to another.

Animals↗
PubMed1980

Experimental Escherichia coli 06 infection in mice. II. Protective factors of immunity after immunosuppression.

The increase of the resistance against intraperitoneal (i.p.) Escherichia coli to infection was studied in immunized mice with or without immunosuppression with cyclophosphamide (Cy), or/and niridazole (Nir). These agents suppress antibody formation and T-cell mediated immunity respectively. An infection system was utilized permitting exclusive study of immunity against the 06 antigen. The antibody titers in serum were recorded with an enzyme-linked immunosorbent assay, ELISA. The following findings were made: (1) One immunization resulted in protection against i.p. E. coli 06 infection as well as in antibody titers measured with the ELISA. Two immunizations given with a 30-day interval increased the noted levels even more. (2) The resistance to infection after one immunization was fully transferable with immune serum; the resistance after two immunizations was not fully transferable with immune serum. (3) Treatment with cyclophosphamide diminished the antibody formation after immunization but not the resistance to infection. The resistance raised by one immunization was transferable by immune serum from immunosuppressed animals; the resistance raised by two immunizations was partly transferable bny such immune. (4) Treatment with niridazole, which inhibits T-cell mediated immunity, did not alone or in combination with cyclophosphamide affect the resistance pattern after immunization.

Animals↗
PubMed1979

Effects of subinhibitory amounts of ampicillin, amoxycillin and mecillinam on the adhesion of Escherichia coli bacteria to human urinary tract epithelial cells: a preliminary study.

Attachment to mucous surfaces may be a prerequisite for bacteria colonizing these surfaces or invading underlying tissues. Subinhibitory amounts of ampicillin and amoxycillin but not mecillinam decreased the attachment of Escherichia coli bacteria to human uro-epithelial cells in vitro. No significant synergistic effect on the attachment by the antibiotics was obtained. The present report indicates a new parameter for the study of antibacterial actions of drugs.

Adhesiveness↗
PubMed1979

Experimental evidence of a decreased incidence of penicillin allergy through use of pure penicillins.

The results revealed the presence of high molecular weight impurities in commercially available penicillins, measured with a radioimmuno assay. The impurities had penicilloyl specificity and induced antibody formation in mice when the contaminated penicillin was administered in 50 mg/kg body weight daily for ten day periods with a 20 to 30 day interval. Penicillin of high purity similarly administered produced very few antibodies. Furthermore, experimentally contaminated penicillin given according to the same schedule caused IgE antibody formation against the penicilloyl moiety, while pure penicillin did not. These findings were explained by the weak immunogenicity of isologous penicilloylated serum albumin in rabbits both regarding the IgE and the IgG/IgM antibody formation compared to the immunogenicity of heterologous bovine serum albumin similarly penicilloylated.

Animals↗
PubMed1979

Immunotherapy in spring-time hay fever. A clinical and immunological study comparing two different treatment extract compositions.

In a study of the efficacy of two different treatment schedules for perennial immunotherapy, 47 adult patients with spring-time hay fever due to allergy against birch and other deciduous trees were randomly assigned to three treatment groups: one group received birch, alder and hazel allergen in Allpyral, another group received the same Allpyral mixture and in addition all relevant tree pollens in aqueous extract and a control group received no injections. For determination of antibody titres the radioallergosorbent test (RAST) and the ammonium sulphate precipitation (ASP) technique were used. Cellular responsiveness was studied by measuring birch pollen (BP) induced leucocyte histamine release in peripheral blood. The clinical and immunological response was similar in the two treated groups. Treated patients had less symptoms and a lower consumption of antihistamine tablets during the pollen season than the control group. Non-IgE BP antibodies and IgE antibodies recorded with the ASP technique increased after immunotherapy while RAST values did not change significantly. A decrease of RAST values from postseasonal values during the first year to preseasonal values in the following year was seen in all patient groups but was less pronounced in treated than in untreated patients. The decrease was more pronounced in patients with high RAST values of postseasonal sera than in patients with low RAST values. Cellular reactivity increased slightly during the first phase of therapy but returned to the pre-treatment level later. Clinical improvement was positively correlated to the percentage increase of non-IgE antibody titre and to the pre-treatment non-IgE/IgE antibody ratio. Patients with high preseasonal RAST titres or high cellular sensitivity tended to have more severe symptoms during the pollen season. It is concluded that a mixture of birch, alder and hazel is sufficient for immunotherapy in spring-term hay fever. It is obvious that changes of a single immunological variable do not account for the therapeutic results in immunotherapy.

Adult↗
PubMed1979

Immunological aspects of pyelonephritis.

Several virulence factors, such as O and K antigens and capacity to attach to uroepithelial cells, seem to be required for Escheria coli to cause acute pyelonephritis. These factors induce an immune response, however, which can modify the course and clinical expression of the infection. During acute pyelonephritis, autoantibodies to the Tamm-Horsfall protein increase. These antibodies, which probably are evoked by a cross-reaction noted between structures of E. coli LPS and the Tamm-Horsfall protein, may add to the renal tissue engagement in interstitial nephritis caused by bacterial pyelonephritis.

Acute Disease↗
PubMed1979

Antigens in penicillin allergy. III. Antigen and antibody levels in mice treated with pure and contaminated penicillins.

Using a radioimmunoassay, it was shown that commercially available ampicillin preparations often contain penicilloylated high molecular weight impurities. These possess immunological activities and stimulate penicilloyl-specific antibody formation in mice treated according to a therapeutic schedule. Using purified and experimentally contaminated preparations it was also found that exposure of the animals to Escherichia coli and Bordetella pertussis bacteria could increase the antibody formation to small amounts of impurities. In addition, penicilloylated antigen could be recorded in serum from treated animals. The antigen formed by penicilloylation in vivo, however, was very weak and did not induce much antibody formation when injected together with Freund's adjuvant in mice or rabbits.

Ampicillin↗
PubMed1978

Secretory IgA antibodies to enterobacterial virulence antigens: their induction and possible relevance.

1) Milk and salivary s-IgA antibodies are via the homing of IgA producing cells from the Peyer's patches closely connected with antigenic stimuli in the intestine. This explains the presence in human milk of s-IgA antibodies against E. coli O and K antigens, V. cholerae and Shigella O antigens, E. coli and V. cholerae enterotoxins. These secretory antibodies can be induced by intestinal exposure and boosted by parenteral vaccination. 2) Preliminary data suggest that the IgA response in the urinary tract and possibly in the lung may be involved in the homing mechanism as well. 3) The protective role of the milk s-IgA antibodies to enterobacterial virulence antigens is strongly suggested, as is the protection mediated by urinary antibodies against urinary tract infections.

Animals↗
PubMed1978

New knowledge in human milk immunoglobulin.

One of the anti-infection principles of maternal milk is the predominant milk immunoglobulin, secretory IgA. This immunoglobulin contains antibodies against many pathogens and potential pathogens, viruses as well as bacteria, including several members of Enterobacteriacae. The antigenic stimuli for these milk antibodies seem to take place in the Peyer's patches of the intestine. Lymphoid cells leaving the patches after antigenic exposure seem to home to the mammary glands via the lymph and blood circulation. As a result, the milk contains secretory IgA antibodies against, among other things, the intestinal bacteria of the mother. These milk antibodies might reflect the spectrum of bacteria and viruses in the community and may be important for the protection of the breast-fed baby. Via the same homing mechanism the maternal milk obtains antibodies against dietary antigens, including cow's milk proteins. Studies of infants on mixed feeding suggest that the secretory IgA antibodies against the bovine proteins diminish the antigenic exposure, indicating the possibility of an anti-allergic mechanism.

Antibody Formation↗