PubMed Health⌕ Search

Biomedical subjects

T Brenner

Publications and source records attributed to T Brenner.

101 records · Page 6Linked to original sources
PubMed1979

Immune response to isolated oligodendrocytes.

Oligodendrocytes were isolated from bovine white matter and were injected with complete Freund's adjuvant (CFA) into experimental animals. Indirect immunofluorescence studies using fluoresceinated goat anti-rabbit or anti-guinea pig immunoglobulin (GARIg; GAGPIg) showed that rabbit and guinea pig anti-oligodendrocyte (RAO, GPAO) sera reacted specifically with the surface of isolated oligodendrocytes in suspension, as well as with oligodendroglia in bovine and human brain sections, and in mouse cerebellum cultures. This activity of RAO was blocked by non-fluoresceinated GARIg and by GPAO, and absorbed by oligodendrocyte preparation (OP) or whole white matter, but not by purified myelin, neuroblastoma or non-brain tissue. Low levels of anti-basic protein antibodies were found in many RAO (but not GPAO) sera by radioimmunoassay, and a few showed significant anti-galactocerebroside antibody by agglutination and radioimmunoprecipation techniques. Guinea pigs sensitized with isolated oligodendrocytes in CFA showed cell-mediated immunity (CMI) to OP as manifested by delayed type skin test and induced in vitro lymphocyte transformation. CMI to purified myelin basic protein was not detected. The demonstration of humoral and CMI to the cell responsible for the production of CNS myelin may be related to some aspects of the immunopathogenesis of demyelinating disorders.

Animals↗
PubMed1976

Extracellular metabolism of cyclic AMP.

Intravenously administered cyclic [8-3H]AMP to rats was quickly eliminated from the circulation. After 2 min 93% of the administered radioactivity disappeared from the plasues was recovered mainly in the form of nucleotides, ATP, ADP, AMP and IMP. In vitro contact of cyclic AMP with perfused liver, isolated liver cells and adipose tissue resulted in a rapid breakdown of the nucleotide, presumably on the outer surface of the cells. The degradation products have been identified mainly as adenosine and inosine. Incubation of adipose tissue and isolated liver cells with [3H] AMP also resulted in the breakdown of the nucleotide in themedium. The rate of AMP degradation by these tissues was faster than that for cyclic AMP degradation. The data suggest that cyclic AMP is readily metabolized on the outer surface of cells to products which may be converted within the cells to nucleotides. These findings seem of importance for the quantitative assessments of cellular cyclic AMP outflow during hormonal stimulation.

Adipose Tissue↗
PubMedDate not supplied

Suppression of experimental autoimmune encephalomyelitis by cannabinoids.

The effect of delta 8-THC on experimental autoimmune encephalomyelitis (EAE) was examined. delta 8-THC is an analogue of delta 9-THC, the psychoactive component of marijuana. It is more stable and less psychotropic than delta 9-THC and like the latter it binds to the brain cannabinoid receptor. Two strains of rats were inoculated for EAE, and delta 8-THC (40 mg/kg) was administered for up to 21 days. delta 8-THC significantly reduced the incidence and severity of neurological deficit in both rat strains. The beneficial influence of delta 8-THC only occurred on oral administration and not with parenteral injection. Serum corticosterone levels were twofold elevated in rats with EAE chronically treated with delta 8-THC. These results suggest that suppression of EAE by cannabinoids may be related to their effect on corticosterone secretion.

Administration, Oral↗
PubMedDate not supplied

Significance in neonatal myasthenia gravis of inhibitory effect of amniotic fluid on binding of antibodies to acetylcholine receptor.

The effect of amniotic fluid on the binding of anti-acetylcholine receptor (anti-AChR) antibodies from myasthenia gravis (MG) patients to AChR preparations was examined by radioimmunoassay using 125I-labelled alpha-bungarotoxin. Human amniotic fluid from healthy women in their second trimester inhibited the in-vitro interaction between antibody and antigen. This finding suggests that during pregnancy there is a similar inhibitory effect in MG on the in-vivo binding of maternal anti-AChR antibodies, transferred through the placenta, to AChR at the fetal neuromuscular junction. The presence of feto-placental inhibitory factors may explain the development of transitory muscular weakness only after birth and only in the minority of the babies born to myasthenic mothers.

Acetylcholine↗
PubMedDate not supplied

Oprelvekin (Neumega), first platelet growth factor for thrombocytopenia.

Oprelvekin decreases the need for platelet transfusion in nontransplant patients receiving myelosuppressive chemotherapy. Until pharmacoeconomics studies determine the most cost-effective strategy for use of oprelvekin, it is likely to be used primarily in patients receiving dose-intensive chemotherapy to maintain the high-dose regimen that may provide a survival advantage for the patient with cancer. Additional product information is available at www.ahp.com/products/neumega.htm.

Antineoplastic Agents↗
PubMedDate not supplied

Suppressive effect of pregnancy on the development of experimental allergic encephalomyelitis in rabbits.

In the present study we have investigated the influence of pregnancy on the induction and development of experimental autoimmune encephalomyelitis (EAE) in rabbits in relation to the time of gestation. Randomly bred rabbits were immunized with encephalitogenic bovine brain homogenate in complete Freund's adjuvant before or during pregnancy. The appearance of EAE was delayed and occurred only after delivery, abortion, or fetal resorption. The incidence of the disease was lower and the duration longer. The levels of antibodies to myelin basic protein, an autoantigen of EAE, as measured by solid phase radioimmunoassay, were lower in the pregnant rabbits as compared to the nonpregnant animals. The suppressive influence of pregnancy on the induction and the development of EAE confirms previous reports demonstrating amelioration of autoimmune diseases and other immunological reactions during the second half of human pregnancy. This effect might be partially attributed to the increased level of alpha-fetoprotein (AFP) and/or other pregnancy-associated factors in maternal serum.

Animals↗