Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic-relapsing experimental allergic encephalomyelitis (CR-EAE) in the Lewis rat, induced by the injection of spinal cord tissue in complete Freund's adjuvant (SC/CFA), was studied in vivo by treatment with liposomes containing central nervous tissue antigens, and in vitro by lymphocyte proliferation assays. Intracardiac administration of myelin basic protein (MBP) liposomes, galactocerebroside (GC) liposomes, or MBP + GC liposomes substantially reduced the clinical severity and/or delayed the onset of the initial phase of disease. Liposomes prepared from whole myelin provided even greater protection, and were effective at suppressing both the first disease episode and the relapses. These results indicate that while GC and MBP may play significant roles in the development of CR-EAE in the Lewis rat, immune responses to other antigens are probably also involved. Splenic and lymph node lymphocytes from MBP-GC liposome-treated rats, and splenic lymphocytes from cytochrome-GC (CYT-GC) liposome-treated rats, showed drastically reduced abilities to proliferate in response to MBP in culture. Spleen cells from both the MBP-GC- and CYT-GC-liposome-treated donors were able to actively suppress antigen-induced proliferation of MBP-primed lymphocytes. These findings suggest participation of both clonal anergy, and active suppressor cells in the liposome-mediated suppression of CR-EAE in the Lewis rat.
 ...
PMID:Treatment of spinal cord-induced experimental allergic encephalomyelitis in the Lewis rat with liposomes presenting central nervous system antigens. 169 33

Spleen cells from a BALB/cByJ mouse previously immunized with purified rat liver microsomal cytochrome P-450c were fused with myeloma cells (P3X63Ag8.653) and 10 hybridoma clones secreting antibody against cytochrome P-450c were selected for characterization. The monoclonal antibodies (C1-C10) were purified from mouse ascites fluid and nine were determined to be distinct immunoglobulins. C6 was an IgG2b, whereas the rest were of the IgG1 subclass. A competitive enzyme-linked immunoassay was used to show that the antibodies were directed against at least five spatially distinct epitopes on cytochrome P-450c. Additional evidence for the recognition of distinct epitopes was provided by Ouchterlony immunoprecipitation of cytochrome P-450c with mixtures of appropriate monoclonal antibodies. Differences in antibody reactivity provided evidence for a sixth overlapping epitope that was recognized by two antibodies (C4 and C6). Three monoclonal antibodies to the same epitope on cytochrome P-450c, (CD2, CD3, and CD5) cross-reacted strongly with cytochrome P-450d, another isozyme induced by 3-methylcholanthrene treatment of rats. The antibodies that did not cross-react with cytochrome P-450d contained kappa light chains, whereas the three cross-reacting antibodies contained lambda light chains. None of the monoclonal antibodies cross-reacted with purified cytochromes P-450a, P-450b, P-450e, P-450f, P-450g, or P-450h or any other cytochrome P-450 in "Western blots" of liver microsomes from untreated or 3-methylcholanthrene-treated rats. C8 was a potent inhibitor of metabolism catalyzed by cytochrome P-450c in a reconstituted system as well as microsomes from 3-methylcholanthrene-treated rats. This antibody effected maximal inhibition of catalytic activity at an approximately 0.5:1 molar ratio of IgG to cytochrome P-450c, i.e. one antibody-binding site per epitope on cytochrome P-450c.
 ...
PMID:Characterization of nine monoclonal antibodies against rat hepatic cytochrome P-450c. Delineation of at least five spatially distinct epitopes. 670 86

3,3',4,4'-Tetrachloroazobenzene is not commercially manufactured but is formed as an unwanted byproduct in the manufacture of 3,4-dichloroaniline and its herbicidal derivatives Propanil(R), Linuron(R), and Diuron(R). In addition, environmental contamination by 3,3',4,4'-tetrachloroazobenzene occurs from the degradation of chloranilide herbicides and the photolysis and biolysis of 3,4-dichloroaniline. 3,3',4,4'-Tetrachloroazobenzene was nominated by the United States Environmental Protection Agency for toxicity testing based on concerns over the potential for human exposure, the structural resemblance to 2,3,7,8-tetrachlorodibenzo-p-dioxin, and the reported dioxin-like effects of 3,3',4,4'-tetrachloroazobenzene. The toxicity of 3,3',4,4'- tetrachloroazobenzene was evaluated in 16-day and 13-week gavage studies in male and female F344/N rats and B6C3F1 mice. In addition to histopathology, evaluations included hematology (rats only), clinical chemistry, thyroid hormone analyses (rats only), cytochrome P(450)1A immunohistochemical staining in the liver (rats only), and assessments of male reproductive endpoints and estrous cycle length. Genetic toxicology studies included mutagenicity tests in Salmonella typhimurium and the determination of micronuclei in mouse bone marrow and peripheral blood erythrocytes. In the 16-day studies, groups of five male and five female rats received 3,3',4,4'-Tetrachloroazobenzene in corn oil by gavage 5 days a week at doses of 0, 12.5, 32, 80, 200, or 500 mg per kg body weight. Groups of five male and five female mice received 3,3',4,4'-Tetrachloroazobenzene in corn oil by gavage 5 days a week at doses of 0, 1, 3.2, 10, 32, or 100 mg/kg. Major effects included increases in liver, lung, and spleen weights of rats and liver and heart weights of mice and decreases in thymus weights of rats and mice. No effects were found on survival or mean body weight gains of rats or mice. Incidences of hematopoietic cell proliferation in the spleen were increased in all groups of dosed male rats, in female rats that received 32 mg/kg or greater, and in 100 mg/kg male and female mice. Renal tubule hyaline droplet accumulation in the cytoplasm of renal cortical epithelial cells and chronic nephropathy were observed microscopically in male rats in the 80, 200, and 500 mg/kg groups. Female mice in the 100 mg/kg group had atrophy of the thymus. In the 13-week studies, groups of 10 male and 10 female rats and mice received 3,3',4,4'-Tetrachloroazobenzene in corn oil by gavage 5 days a week at doses of 0, 0.1, 1, 3, 10, or 30 mg/kg. In the 13-week rat study, the major effects included a decrease in the mean body weight gain of 30 mg/kg females and final mean body weights of 30 mg/kg males and females, decreased thymus weights of males and females in the 10 and 30 mg/kg groups accompanied by thymic atrophy observed microscopically, increased incidences of hematopoietic cell proliferation in the spleen in 10 and 30 mg/kg males and females, a responsive anemia in 10 and 30 mg/kg males and females at week 13, and decreased platelet counts in 10 and 30 mg/kg males and females on day 21 and at week 13. Spleen weights were increased in 10 and 30 mg/kg males and females. Liver weights were increased in males that received 1 mg/kg or greater and in 10 and 30 mg/kg females. Furthermore, hepatic cytochrome P(450)1A staining presence and intensity were increased in 30 mg/kg males and females. Sharp decreases in circulating thyroxine concentrations were observed in males and females at all doses. In spite of this sharp decrease, thyroid-stimulating hormone concentrations were marginally increased. Incidences of hyperplasia of the forestomach were increased in males administered 3 mg/kg or greater and females administered 30 mg/kg. In the 13-week mouse study, the major effects included increases in liver and spleen weights of 10 and 30 mg/kg males and females and increased incidences of hyperplasia of the forestomach in males and females that received 1 mg/kg or greater. Furthermore, a decrease in thymus weight of 30 mg/kg males, an increase in centrilobular hypertrophy of hepatocytes in males that received 3 mg/kg or greater, and an increase in the incidences of hematopoietic cell proliferation in the spleen in males that received 3 mg/kg or greater were observed. A significant decrease in epididymal spermatozoal concentration was observed in 3 and 30 mg/kg males. 3,3',4,4'-Tetrachloroazobenzene was mutagenic in S. typhimurium strain TA97 in the presence of rat liver S9 activation enzymes; no mutagenic activity was detected in strain TA98, TA100, TA1535, or TA1537 with or without S9. In vivo, the frequency of micronucleated erythrocytes was significantly increased in peripheral blood samples from male and female mice given 3,3',4,4'-Tetrachloroazobenzene by gavage for 13 weeks. However, results of a 3-day exposure of up to 200 mg/kg by intraperitoneal injection did not demonstrate induction of micronuclei in bone marrow erythrocytes of male mice. In summary, 3,3',4,4'-Tetrachloroazobenzene caused typical dioxin-like effects, such as thymic atrophy, an increase in liver weights, induction of hepatic cytochrome P(450)1A, and decreased mean body weight gains. Furthermore, in the 13-week studies, a sharp decrease in circulating thyroxine concentrations was observed even at the lowest dose (0.1 mg/kg) tested in rats. Other effects included a decrease in epididymal spermatozoal concentration in mice, major effects on the hematopoietic system, and increased incidences of hyperplasia of the forestomach in 3 and 30 mg/kg males and 30 mg/kg females. A no-observable-adverse-effect-level (NOAEL) was not reached in rats. The NOAEL in mice was 0.1 mg/kg. Comparison of various dioxin-like effects in these studies with those reported in the literature indicate that 3,3',4,4'-Tetrachloroazobenzene is six to two orders of magnitude less potent than 2,3,7,8-tetrachlorodibenzo-p-dioxin.
 ...
PMID:NTP Technical Report on the Toxicity Studies of 3,3',4,4'-Tetrachloroazobenzene (CAS No. 14047-09-7) Administered by Gavage to F344/N Rats and B6C3F1 Mice. 1198 82