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Biomedical subjects

L Mandel

Publications and source records attributed to L Mandel.

At least 145 records · Page 8Linked to original sources
PubMed1984

Interaction of xenogeneic antiglomerular antibodies with foetal pig tissues.

Rabbit anti-swine-glomerular-immunoglobulin (AG Ig) was administered in utero to 14 pig foetuses 40-103 d post-conception. In nine foetuses AG Ig was injected into the umbilical vein and 60 min later kidneys and other organs were collected. In five others, AG Ig was injected via the intact uterine wall, and the tissues were examined after further 11 or 35 d of uninterrupted pregnancy. No signs of glomerular inflammation were found by light microscopy. In electron microscopy, especially in younger foetuses, focal endothelial defects and subendothelial granular "deposits" were seen in deep glomeruli, but they appeared also in control foetuses of corresponding age. Immunofluorescence microscopy showed a strong diffuse linear positivity of the swine-anti-rabbit-Ig conjugate in the capillary loops of deep juxtamedullary glomeruli irrespective of foetal age and dose of antigen injected. Immature glomeruli and S-bodies yielded a poor to negative staining. Proof of swine Ig was negative in all kidneys as well as the test for rabbit and swine Ig in various other organs. Traces of rabbit Ig were only detected in disseminated platelet aggregates of myocardium in the early post-injection period. Ultrastructural enzyme-antibody assay visualized AG Ig throughout all three layers of glomerular capillary basement membrane, and in the early period signs of transendothelial passage and escape of unbound rabbit Ig molecules were evident. The mesangial matrix, cell membranes, and extraglomerular basement membranes remained all negative. As follows, xenogeneic antiglomerular antibodies specifically react with target structures even at the end of the first third of intrauterine life, afflicted being only the deep mature polyanion-coated glomeruli. The foetal immune system is incapable of an adequate autologous antibody response, and we have failed to find even an early glomerular lesion comparable with the postnatal anti-basement-membrane glomerulonephritis.

Animals↗
PubMed1981

Ontogeny of lymphatic structures in the pig omentum.

The development of lymphoid populations in the omentum majus during the prenatal and postnatal life of the pig was studied. T lymphocytes, monocytes and mast cells were first found on the 40th day of gestation. B lymphocytes appeared on the 72nd day of gestation when the first macrophage aggregates were formed. Macrophages appeared to be the prerequisite for the formation of dense lymphatic areas (DLA's). At later stages T cells were observed only in the omentum of germfree pigs. DLA's of conventional pig omentum are filled exclusively with B cells.

Animals↗
PubMed1981

Peroral immunization of germfree piglets: appearance of antibody-forming cells and antibodies of different isotypes.

Precolostral germfree piglets were perorally immunized with sheep erythrocytes daily, beginning on the 5th day of life. At different intervals the numbers of IgM, IgG and IgA antibody-forming cells were estimated in the spleens, lymph nodes and intestinal mucosa by the haemolytic plaque method. In the beginning of the response IgM antibody-forming cells were detected in intestinal mucosa and mesenteric lymph nodes. IgA plaque-forming cells appeared later and were predominant during the whole period in all organs tested. In all lymphatic organs tested the appearance of IgG antibody-producing cells followed that of IgA plaque-forming cells. The development of immunoglobulins and antibody of different isotypes in intestinal contents and sera was compared with the cellular kinetics found in these young animals after local stimulation.

Administration, Oral↗
PubMed1980

Changes in the intestinal epithelial cells in abdominally irradiated germfree piglets.

The renewal time of intestinal epithelial cells was established using tritiated thymidine in 14-day-old conventional piglets as 96 hours, but 192 hours in germfree piglets. In germfree piglets, irradiated by single abdominal exposure to 60Co gamma-rays with 3.87 x 10(-1) C kg (= 1500 R), the first degenerative signs in the ileal epithelial cells were found on the 13th postirradiation day. Since that day, the columnar epithelial cells exhibited progressive degeneration changes in their ultrastructure. Quickly growing, substituting flat epithelial cells occurred beginning with the 15th day after irradiation and covered parts of the leveled denudated intestinal mucosa. These flat epithelial cells also exhibited degenerative changes.

Animals↗
PubMed1979

Gnotobiotic techniques.

A brief review is given of the development of equipment used for rearing germfree animals in various laboratories and of our experience with designing germfree isolators and with the technology of rearing germfree piglets is presented. The philosophy of isolation as applied to the animal as a biological unit, the elimination of contamination and the theoretical prerequisites of isolation were considered by Reyniers (1943, 1959) and Trexler (1960).

Animal Feed↗
PubMed1979

A feminist approach for the treatment of drug-abusing women in a coed therapeutic community.

Experiences with female addicts in a feminist awareness group within a coed therapeutic community are reported. The group met for 16 months and was based on a variety of therapeutic techniques and educational presentations. The intervention resulted in more communication and trust among the women, increased interest in health-related concerns, a reduced sense of alienation, and gains in self-respect. The article discussed the issues and implications of resistance to the group, timing, development of indigenous leadership, training for feminist therapists, and the use of outside professional consultants in therapeutic communities.

Adolescent↗
PubMed1977

Equipment for germ-free caesarean section and baby care.

A germ-free isolator system was designed and constructed. It permits a sterile caesarean section and rearing of an infant under germ-free conditions. The system includes a plastic surgical and rearing isolator and two supply isolators; one of the supply isolators served as a transport mobile unit of staff participating in the sterile caesarean section and in the postnatal care of the germ-free newborn underwent to a special training and all of them were able to meet the high requirements of this work. The surgery itself was without complications. The newborn was absolutely sterile up to the age of 1 month; afterwards the infant was gradually colonized with selected strains of bacteria and thus prepared for conventialization. In the course of this work further possibilities of application of gnotobiological techniques in pediatrics were proposed (e.g. care of premature, high-risk neonates).

Animals↗
PubMed1976

Transient bacteremia in pediatric patients after dental extraction.

The incidence of bacteremia in a group of well children undergoing dental extraction of both normal and abscessed teeth was determined. Blood samples were obtained from each child before and immediately after dental instrumentation and then cultured aerobically and anaerobically. Eleven of 36 (30%) of the postextraction cultures were positive, and Streptococcus viridans grew from all of them. Bacteremia was more common after the extraction of diseased teeth, and there was no relationship between bacteremia and the number or species of teeth removed.

Adolescent↗