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Biomedical subjects

A Gunnarsson

Publications and source records attributed to A Gunnarsson.

At least 73 records · Page 4Linked to original sources
PubMed1984

Specific cleavage of the glycosidic bond between the carbohydrate and ceramide portions in glycosphingolipids using trifluoroacetolysis.

A number of glycosphingolipids have been subjected to trifluoroacetolysis. Heating the glycosphingolipid at 100 degrees C for 48 h in mixtures of trifluoroacetic acid (TFA) and trifluoroacetic anhydride (TFAA) varying from 1:1 to 1:100 (v/v) resulted in complete cleavage of the glycosidic bond between the carbohydrate and the unsaturated base of the ceramide. The fatty acid(s) linked to the amino group of sphingosine were also released by transamidation. The carbohydrate portion was stable under these conditions due to stabilization of the glycosidic bonds by the electronegative O-trifluoroacetyl groups. The 2-acetamido-2-deoxy-hexose units in the glycosphingolipids were converted into their N-trifluoroacetyl analogues. The N-trifluoroacetyl functions could be removed and the 2-acetamido-2-deoxy-hexoses could be reconstituted by N-acetylation.

Carbohydrates↗
PubMed1979

Adjuvant immunotherapy of malignant melanoma.

A vaccine made of irradiated Vibrio cholerae neuroaminidase (VCN) treated autochthonous tumor cells plus BCG was utilized in combination with surgery or with chemotherapy for Stage II and Stage III malignant melanoma, respectively. A few patients with Stage I melanoma were treated with surgery and BCG. Most of the studies were carried out on a prospective, randomized protocol. When the results with conventional therapy were compared with the results of conventional therapy plus immunotherapy, no beneficial effects of the immunotherapy were seen. Stratification insured comparability in both immunotherapy and nonimmunotherapy groups. We conclude that VCN treated tumor cells plus BCG, when administered according to the protocol utilized here, offer patients with malignant melanoma no substantial benefit when compared with conventional therapy.

BCG Vaccine↗
PubMed1979

The value of preoperative screening procedures in stage I and II malignant melanoma.

Fifty patients with melanoma (30 with clinical Stage I disease and 20 with clinical Stage II disease) were analyzed retrospectively along with the screening test done prior to surgery. While the value of the chest X ray is unquestioned in preoperative screening, the same cannot be said of liver, brain, and bone scans. The bone marrow biopsy, however, done with a Janshidi needle was of value in detecting one patient with bone-marrow metastases who on examination had clinical Stage II disease and precluded surgery in this same individual. Therefore, we feel that in the preoperative scanning of patients with Stage I or Stage II human malignant melanoma, and especially in the latter, the bone-marrow biopsy should be done routinely in addition to a hematological profile, liver profile, and chest X ray.

Bone Marrow Examination↗
PubMed1979

Evaluation of different antigens in the complement-fixation test for diagnosis of Haemophilus pleuropneumoniae (parahaemolyticus) infections in swine.

The identification of new serotypes of Haemophilus pleuropneumoniae (parahaemolyticus) and the frequency of pleural adhesions due to contagious pleuropneumonia in many fattening swine herds have prompted the study of the complement-fixation (CF) test as a diagnostic tool for use in swine. Whole cell antigens, mixed antigens, autoclaved antigens, and phenol-water-extracted antigens derived from different serotypes were prepared and tested with immunized-swine sera by the CF test. Mixed antigen consisting of whole cells from all known serotypes was the best screening antigen for routine use. This antigen gave positive titers with all sera in which a positive reaction against the separate serotype antigen was registered. The most highly serotype-specific reactions were obtained with antigens prepared by phenol-water extractions of whole cells. When whole-cell antigens were used in the CF test, antibodies to superficial serotype-specific and common species-specific antigens could be detected.

Animals↗
PubMed1979

Serologic studies on porcine strains of Haemophilus parahaemolyticus (pleuropneumoniae): extraction of type-specific antigens.

By the use of phenol water extraction it was possible to obtain strictly serotype-specific antigens from mucoid cell cultures of five serotypes of Haemophilus parahaemolyticus (pleuropneumoniae). These serotype-specific antigens did not cross-react with each other in immunodiffusion tests. The type-specific precipitating phenol-water-fractions were composed of two to four antigenic components, presumably of polysaccharide or lipopolysaccharide nature.

Animals↗
PubMed1977

Cultural and biochemical criteria for the identification of haemophilus spp from swine.

Twenty-two Haemophilus cultures of types prevalent in swine and of different geographic origins were subjected to biochemical and cultural examinations. Three subgroups were identified: One was unrease-positive, produced porphyrin from delta-aminolevulinic acid, and grew on infusion mediums supplemented only with V factor; the 2nd was unrease-negative, porphyrin-positive, and grew only on serum-enriched mediums with added V factor; and the 3rd was unrease-negative, porphyrin-negative, and grew only on serum-enriched mediums with added V and X factors. The groups generally corresponded to Haemophilus parahaemolyticus, Haemophilus parasuis, and Haemophilus suis, respectively. By means of the unrease and porphyrin tests, it was possible to assign, presumptively, porcine haemophilus cultures to 1 of the 3 species. Other tests, such as beta-galactosidase, hemolysis, and fermentation of carbohydrates were of secondary value in differentiating between these species.

Animals↗
PubMed1977

Recent experiences with the Salmonella-O-1-phage in routine diagnostic work.

Sensitivity to the O-1-phage was tested on 5287 Salmonella strains isolated in the course of routine diagnostic work over the period 1971-1973. 3380 (99,2%) strains of the B group, 676 (97,8%) of the C group, 840 (98,8%) of the D group, and 195 (83,0%) of the E group strains were sensitive to the O-1-phage. 92 of the 5 287 strains belonged to other O-groups in the Kauffmann-White scheme; 91,3% of these were phage-positive. 5274 of the strains belonged to subgenus I and only 100 of them were not sensitive to the O-1-phage. A total of 13 strains belonged to subgenera II, III, and IV. The O-1-phage was considered to be suitable for the identification of Salmonella bacteria. It should, however, be observed that monophasic strains belonging to subgenus III and strains belonging to subgenus IV are usually not sensitive to the O-1-phage. Of the total number of strains, 98,0% were sensitive to the O-1-phage.

Animals↗
PubMed1977

Serologic studies on porcine strains of Haemophilus parahaemolyticus (pleuropneumoniae): agglutination reactions.

Fifteen strains of Haemophilus parahaemolyticus (pleuropneumoniae) represented by 6 American isolates, 6 Swedish isolates, and 3 reference strains of Nicolet's serotype 1, 2 and 3, were used in serologic studies by agglutination and agglutinin-adsorption tests. By whole cell-agglutination tests in rabbit antiserums, 3 additional serotypes, 4, 5, and 6, were identified. All strains had strong serotype-specific agglutinating properties. Occasional weak cross reactions could be eliminated by appropriate adsorptions without effect upon type-specific reactivity. The Swedish isolates were assigned to serotypes 2, 3, 4, and 6, and the American isolates, to serotypes 4 and 5. All European isolates were distinct from 5 of the 6 American strains. An American culture isolated from a steer and another from a lamb were identical in their agglutination reactions with the porcine isolates of serotype 5. The serotyping of isolated strains is important in the epizootiologic and immunologic studies of H parahaemolyticus infections.

Adsorption↗
PubMed1976

[Isolation of Campylobacter fetus in two herds of sheep in Sweden (author's transl)].

In two herds of sheep with numerous abortions Campylobacter fetus subspecies intestinalis was isolated from fetuses, fetal membranes, and faecal specimens. In herd A, with good hygiene, 12 ewes out of 250 aborted. In herd B, with poor hygiene, 54 out of 171 ewes aborted and 14 of them died; for a further 9 ewes the lambs died postnatally. The clinical course in both herds shows that proper supervision and possibilities of prompt isolation of aborting ewes can substantially reduce the spread of infection within the herd. The isolated strains of C. fetus subsp. intestinalis were catalase-positive, did not grow in deep culture on 0.5% semisolid agar, reduced nitrate, did not grow in 3,5% NaCl, but grew in 1% ox bile and 1% glycine. All the strains were negative with respect to H2S production on TSI but positive on lead-acetate strips. In serological tests, positive agglutination titres were demonstrated only in aborting ewes from herd B. Positive titres were also demonstrated in a ram from the same herd.

Abortion, Septic↗