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Biomedical subjects

R R Kretschmer

Publications and source records attributed to R R Kretschmer.

At least 55 records · Page 3Linked to original sources
PubMed1980

Chemotaxis.

Chemotaxis is defined as the ability of living cells to determine the direction of their locomotion along a concentration gradient of attractant and repellant substances. A survey is given of the various in vitro techniques for detecting chemotaxis in leukocytes including monocyte macrophages, polymorphonuclear cells, lymphocytes and bacterial cells. Biological substances such as complement and its components, factors derived from lymphocytes and other proteins which cause chemotaxis are also described. Finally, reference is made to the relationship between chemotaxis and manifestations of disease (e.g. inflammatory response) and defects in the chemotaxis-inducting systems in man in certain diseases (Chediak-Higashi syndrome, lazy leukocyte syndrome, etc.). Possible means of therapy of abnormal chemotaxis in man are still in the discussion stage.

Antibody Formation↗
PubMed1980

Protective value of gamma globulin preparations against group B streptococcal infections in chick embryos and mice.

The protective value of pooled human gamma globulin (GG) and a group B streptococcal immune globulin (GBSIG) was studiedf in a chick embryo and a murine model of group B streptococcal (GBS) infection. Chick embryos were protected by the IV administration of 0.4 to 0.8 mg of GG from three manufacturers against IV challenge with type Ia GBS. Two of three GG preparations at doses of 0.4 to 1.65 mg protected chick embryos against type III, but 1.65 mg of all three preparations failed to protect against GBS types Ib and II. MIce were protected from lethal IP challenges with types Ia and Ib by the prior IM inoculation of three and two of the three GG preparations at doses of 0.5 to 1.0 mg, respectively. Administration IM of 1 mg of GG failed to protect mice against types II and III. The IV administration of 0.2 mg of GBSIG protected chick embryos against IV inoculation with GBS types Ia, Ib, II, and III. Administration IM of 0.5 mg of GBSIG protected mice against IP challenges with types Ia, Ib, and II, but not with type III. The IP administration of 0.25 mg of GBSIG simultaneously with type III GBS protected mice, whereas GG was not protective. GBSIG should undergo clinical trials for the prevention of GBS infections and their recurrences and as a possible adjunct to antibiotic and supportive therapy of severe GBS infections.

Animals↗
PubMed1979

Human immunity to group B streptococci measured by indirect immunofluorescence: correlation with protection in chick embryos.

An indirect immunofluorescence (IF) assay has been developed as a useful semiquantitative method for determination of type-specific IgG antibody in human sera to the five serotypes of group B Streptococcus. Antibody titers measured by IF correlated with passive protection in chick embryos, and antibody titers associated with chick embryo protection were delineated. Except for types Ia and Ic, IF antibody to each of the streptococcal types was completely absorbed by homologous strains, and antibody titers were unchanged by incubation with heterologous bacteria. For types Ia and Ic, IF antibody was absorbed by either the Ia or the Ic strain and by native Ia carbohydrate antigen. Antibody titers measured by IF and chick embryo protection against types Ia and Ic were similar, but were divergent for Ib and Ic, a finding suggesting that antibody is predominantly directed to the major carbohydrate determinants. In addition, 29 of 31 sera that had been tested in chick embryos yielded comparable results in mice against challenge with type Ia group B Streptococcus, a finding further validating the chick embryo assay. Sera from all of 43 mothers of infants infected with group B streptococci had antibody titers by IF that were less than titers associated with protection in chick embryos.

Absorption↗
PubMed1978

Enhancement of antigen-induced leukocyte histamine release by a mononuclear cell--derived factor.

Supernatant fluids of phytohemagglutinin-stimulated mononuclear cells from ragweed-sensitive patients significantly enhanced the release of histamine from antigen-triggered leukocytes of ragweed-sensitive as well as control individuals. Supernatants of mononuclear cells from control individuals did not reveal this enhancing effect, nor was it found with the use of supernatants of unstimulated mononuclear cells of ragweed-sensitive patients or culture media with PHA alone. Supernatant fluids of phytohemagglutinin-stimulated mononuclear cells of patients sensitive to trees and grass also revealed this enhancing effect. The factor(s) responsible for the enhancement of antigen-induced histamine is heat labile and has a molecular weight of less than 10,000 daltons. The mechanism and site of action of the enhancing factor could involve initiating and/or modulating steps of the leukocyte histamine release reaction. This factor, presumably a lymphokine or a monokine, may constitute a regulating link between cell-mediated immunity and histamine-mediated hypersensitivity reactions in allergic patients.

Adolescent↗
PubMed1978

Chicken embryo model for type III group B beta-hemolytic streptococcal septicemia.

A lethal septicemia was induced in 11- and 12-day-old chicken embryos with intravenous inoculation of relatively small numbers of a clinical isolate (GBBHS-III-Bell) or a reference strain (GBBHS-III-D136-C) of group B beta-hemolytic streptococci (GBBHS). GBBHS-III-Bell was more virulent than GBBHS-III-D136-C, and 11-day-old chicken embryos were more susceptible than 12-day-old chicken embryos. Type-specific rabbit antisera protected the embryos from bacterial challenge, and this protective effect was absorbed with homologous but not heterologous GBBHS strains. A heterologous antiserum and normal rabbit sera provided some protection, which could be absorbed with either homologous or heterologous GBBHS strains. The chicken embryo is a suitable animal model for the study of infection and immunity with GBBHS type III.

Animals↗
PubMed1978

Synovial cysts in juvenile rheumatoid arthritis.

In a case of juvenile rheumatoid arthritis with large synovial cysts, cyst fluid aspiration was performed to relieve pain, but recurrence was prevented with salicylate therapy alone. The mechanism of formation of synovial cysts is discussed.

Arthritis, Juvenile↗
PubMed1977

Perinatal immunity to group B beta-hemolytic streptococcus type Ia.

Sera from 14 of 56 adult women protected mice from intraperitoneal challenge with mouse-virulent group B Streptococcus serotype Ia, and sera from seven of 25 nonparturient women in this group were bactericidal for greater than 99% of the organisms in the presence of normal polymorphonuclear leukocytes. There were no discrepancies between the in vivo and in vitro assays. Protective activity was found in the IgG class in seven sera, and in the IgM class in one. Opsonic activity was partially dependent on heat-labile serum factors. Of 31 mother-cord serum pairs studied, seven maternal sera were protective, but four of the corresponding cord sera were not. Pooled human gamma-globulin injected by either the intraperitoneal or the intramuscular route protected mice from bacterial challenge.

Adult↗
PubMed1977

Group B streptococcal long-chain reaction.

The streptococcal long-chain reaction was adapted for the measurement of type-specific antibodies to group B beta-hemolytic streptococci (GBBHS). Rabbit antisera incubated with homologous but not heterologous GBBHS produced chains that were 18 to 33 times longer than chains produced by normal rabbit sera. The long chains were easily apparent, in most instances, by scanning the slides. Human sera with mouse protective and opsonic activity against GBBHS serotype Ia produced chains that were always significantly longer than those produced by incubation in nonimmune human sera. Absorption of rabbit or human sera with homologous but not heterologous organisms inhibited the capacity to induce the formation of long chains. The long-chain assay is a simple, rapid, and reproducible test that could constitute a valuable tool for the rapid identification of anti-GBBHS antibodies.

Animals↗
PubMed1977

Chronic bullous dermatosis of childhood.

The clinical features, laboratory studies, and therapeutic responses of two boys with chronic bullous dermatosis of childhood are described. Direct immunofluorescent preparations of sections from a lesion, skin adjacent to a lesion, and uninvolved skin demonstrated linear deposition of IgA at the dermoepidermal junction in all three biopsy specimens from one patient. Similar preparations from the second child were negative for staining. No circulating antibodies to skin components were detected in either child by means of multiple substrates. Neither child had clinical manifestations nor laboratory findings suggestive of an associated gastrointestinal lesion; therefore, small bowel biopsies were not performed. Immunologic studies failed to demonstrate any of the abnormalities frequently described in dermatitis herpetiformis. Both boys responded dramatically to sulfapyridine therapy.

Age Factors↗
PubMed1976

Technetium-99m labeling of human monocytes for chemotactic studies.

Although the current use of 51Cr for the evaluation of monocyte chemotaxis has yielded encouraging results, certain properties of this radionuclide leave room for improvement. Technetium-99m was evaluated as an alternative label for this purpose. A cell loss of 50% was found, but the recovered cells showed excellent viability and function. Chemotaxis was measured using a modified Boyden's chamber and a lymphocyte-derived chemotactic factor. The chemotactic properties of 99mTc-labeled human monocytes were preserved, and an excellent correlation between radioactive measurement and microscopic counting of migrating cells was observed.

Chemotaxis, Leukocyte↗