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Biomedical subjects

L Mandel

Publications and source records attributed to L Mandel.

At least 109 records · Page 6Linked to original sources

Postirradiation changes in small intestine mucosa of piglets selectively decontaminated by peroral antibiotics.

There was performed light microscopic and morphometric comparison of changes in the intestinal mucosa structure after the irradiation of the lower part of body by radiation 60Co in a dose of 12 Gy, observed the third day after irradiation in piglets kept under conventional conditions and the fifth, the fifteenth and the twentieth days after irradiation in piglets kept under the conditions of selective decontamination by peroral antibiotics. The non-irradiated animals kept conventionally as well as under the conditions of decontamination served as controls. The estimation was performed on transverse slices of the cranial part of jejunum and of the caudal part of ileum. The slices were stained by the method hematoxylin-eosin. The drawings prepared with the help of the projective microscope Pictoval were used for measuring on the apparatus for the quantitative analysis of image MOP AM 03. A markedly lower damage of the intestinal mucosa was evidenced in piglets selectively decontaminated by peroral antibiotics. In the studied time intervals after irradiation in a dose of 12 Gy, the epithelial cover of mucosa, the crypt epithelium and the general outline of mucosa are much better maintained. The favourable effect of the selective decontamination on the maintenance and regeneration of the mucosa of jejunum and ileum is confirmed by a range of morphometric parameters.

Administration, Oral↗

Stimulating effect of Streptococcus faecalis on phagocytosis in gnotobiotic piglets.

The concentration of active phagocytes in peripheral blood remained in germfree pigs up to the age of one year approximately at the same level as found at the age of 7 d and did not exceed 0.3 X 10(9)/L of blood, whereas a steady increase was established in conventional pigs. Monoassociation of gnotobiotic piglets with Streptococcus faecalis increased during 24 h the concentration of circulating granulocytes and the concentration of active phagocytes. An even more pronounced effect was obtained when formolized S. faecalis cells were applied intraperitoneally to germfree piglets. This treatment elevated the phagocytosis index also in conventional piglets, as well as in germfree piglets previously given cyclophosphamide. Escherichia coli O 83 or a mixture of anaerobic bacteria did not cause any serious changes in the activity of phagocytosis in gnotobiotic piglets. S. faecalis seems to be a natural factor stimulating both the release of granulocytes from their depots as well as their phagocytic activity.

Animals↗

Immunological state of adult germfree miniature Minnesota pigs.

Fundamental hematological and immunological data were obtained on sexually mature germfree miniature pigs fed, after the milk diet period, with cereal-type diet sterilized by gamma-radiation, and were compared with data of control conventional animals. Germfree adult pigs had a lower count of peripheral blood leukocytes with a lower percentage of neutrophil granulocytes and without any younger forms, a lower total serum protein level with a negligible amount of gamma and alpha 2 globulin fractions and a higher serum albumin and beta globulin level. In the mesenteric lymph nodes and in spleen, surface IgA-bearing cells predominated over surface IgG-bearing cells. Also a large amount of IgA-containing cells was found in the intestinal lamina propria, where the IgG cells were present in a negligible amount. IgM cells were the most frequent surface isotype in peripheral blood. The count of blood T lymphocytes was more than doubled.

Animals↗

Occult polymicrobial endocarditis with Haemophilus parainfluenzae in intravenous drug abusers.

PURPOSE AND PATIENTS AND METHODS: Fewer than 8 percent of intravenous drug abusers are found to have polymicrobial endocarditis. We report on cases of occult polymicrobial infective endocarditis with Haemophilus parainfluenzae in 10 intravenous drug abusers. Clinical and laboratory data on all 10 patients were obtained from hospital charts, and information on illicit drug use methods was given by five patients. Blood cultures were performed, as well as susceptibility testing to antibiotics. Subsequent molecular epidemiologic studies were performed on selected Staphylococcus aureus and H. parainfluenzae strains. Phage typing of S. aureus and biotyping of H. parainfluenzae strains were also done. RESULTS: Results of the initial blood cultures were positive on the second to fifth days (mean, 2.6 days), demonstrating a gram-positive pathogen in nine patients and Bacteroides asaccharolyticus in one. Significantly, in each case, H. parainfluenzae alone was subsequently identified from additional blood cultures, with a mean delay of 20.4 days (range, five to 57 days) to the isolation of this organism. Epidemiologic data indicated that our cases did not represent a point-source outbreak. Antibiotic therapy uniformly failed until an agent active against H. parainfluenzae was added. The constellation of clinical, microbiologic, and epidemiologic findings was similar, and permitted prospective diagnosis and therapy in three patients. Despite the absence of S. aureus bacteremia in four, all 10 patients had right-sided endocarditis with septic pulmonary emboli. Five patients had initial blood cultures that were positive for two facultative gram-positive cocci (S. aureus and commensal oral streptococcal species). CONCLUSION: Our findings suggest that polymicrobial endocarditis with H. parainfluenzae in intravenous drug abusers is a distinct clinical syndrome, and should be considered in all patients if the response to appropriate antibiotics is atypical or if pulmonary emboli continue with therapy.

Adult↗

Ontogeny of T lymphocytes in the pig.

Mononuclear cells isolated from pig fetal thymus (and thymus region), spleen and cord blood were examined for their reactivity with polyclonal sheep anti-pig T cell antiserum. First immunofluorescence-positive cells were detected after 28 d of gestation in the thymus region, cord blood and the liver.

Animals↗

The adherence of Escherichia coli to the intestinal epithelium of piglets.

The ability of some pathogenic strains of E. coli to adhere to the intestinal epithelium significantly enhances their effectivity. This adhesion of particular pigs' strains is mediated by specific pili possessing the K 88 antigen found on the outer membrane of the bacterial cell. In in vitro experiments with isolated piglets' enterocytes, a considerable adherence of the E. coli K 88+ strain was found when compared with the same bacterial strain but lacking this plasmid-directed antigen. Comparable results were obtained in in vivo experiments with ligated intestinal loops as well as with monoassociated piglets. Furthermore, the adherence ability is most pronounced at the early postnatal period and is negligible in adult pigs.

Animals↗