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

A multiple end-point approach to assessing genetic toxicity (the combined testing protocol, CTP) was evaluated in male and female CD-1 mice exposed subacutely (3 and 6 weeks) to low levels of a custom-blended gas mixture (epichlorohydrin, benzene, chloroprene and xylene, at 50, 100, 100, and 100 ppb, respectively, as the low dose, with concentration levels 10-fold and 100-fold higher as the intermediate and high doses, or 0.1, 1 and 10 ppm of benzene). Urine mutagenicity was tested in the Salmonella/microsome assay, chromosome aberrations were examined in bone marrow and spleen lymphocytes, micronuclei were measured in bone marrow and peripheral erythrocytes, and cytochrome P450 and glutathione S-transferases were measured in the liver. Structural aberrations in alveolar macrophages and spermatocytes, and thioguanine resistance in spleen lymphocytes were examined for their suitability for incorporation into the overall protocol. Spleen lymphocytes were the most sensitive indicator cells, and showed a dose-related increase (P less than 0.01) in structural chromosome aberrations and in cytotoxicity after 6 weeks of exposure. Analysis of micronucleus formation and metaphase aberrations in the bone marrow, and micronuclei in peripheral erythrocytes showed an overall statistically non-significant but positive trend at the high dose. No mutagenicity was detected in pooled urine samples. Liver microsomal cytochrome P450 was not increased, but cytosolic glutathione S-transferases were significantly increased in a dose-related manner. Since the probability of detecting a genotoxic effect increases with the number of endpoints and tissues examined, this approach should be applicable to many situations without having to perform separate experiments for each tissue examined.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A combined testing protocol for assessing genotoxicity in individual animals: application to environmental toxicology. 265 62

The dolichol and dolichyl phosphate (Dol-P) content of various tissues and liver subcellular fractions obtained from rats have been measured directly using high pressure liquid chromatographic methods developed in this laboratory. Spleen contained the highest concentration of dolichol, while other tissues including serum had smaller amounts. Although considerable differences in homologue distribution patterns were observed among the tissues examined, a number of purified subcellular fractions obtained from liver (nuclei, mitochondria, cytosol, and microsomes) exhibited a single common pattern. Only some 5% of liver dolichol appeared in the microsomal compartment of the cell where glycoprotein formation occurs, while 50% of the dolichol in this tissue was found in a lysosome-enriched fraction. The concentrations of dolichol present in liver nuclei, mitochondria, whole microsomes (also rough and smooth, endoplasmic recticulum (RER and SER, respectively), and cytosol were considerably lower (on a protein basis) than those present in whole liver. Besides the lysosome-enriched fraction, only plasma membranes and Golgi contained dolichol at concentrations equal to or greater than those present in liver homogenates. The low concentrations of dolichol found in microsomes suggest that the amounts of dolichol available for Dol-P formation via the CTP-dependent kinase reaction may be rate limiting. Most of the Dol-P in liver could be recovered in the microsomal fraction. Dol-P accounted for 4 and 40% of the sum of alcohol + dolichyl fatty acyl ester + Dol-P forms present in whole liver and in microsomes, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Distribution and metabolism of dolichol and dolichyl phosphate in rat liver. 631 69

Human chorionic gonadotropin (hCG) belongs to the family of glycoprotein hormones. All members of the family are composed of an identical alpha subunit and structurally related beta subunit which confers biological specificity. Specific quantification and functional analysis of hCG require the use of monoclonal antibodies recognizing different epitopes of hCGbeta. This study describes the production and characterization of monoclonal antibodies (MAbs) to hCGbeta with no cross-reactivity to other glycoprotein hormones. Spleen cells from Balb/c mice immunized with hCG were fused with mouse SP2/0 myeloma cells. Fused cells were grown in hypoxanthine, aminopterine, and thymidine (HAT) selective medium and cloned by limiting dilution assay. Antibody-secreting cells were screened by enzyme-linked immunosorbent assay (ELISA) and the specificity of secreted MAbs was further analyzed, using a panel of highly purified and recombinant glycoprotein hormones, their subunits and peptides representing the C-terminal end of hCGbeta (hCGbeta-CTP) by ELISA and immunoblotting. The affinity constant (K(aff)) was also determined by ELISA. Three murine hybridomas designated G5M1, B12M2 and F4M3 were obtained that secrete MAbs specific for hCGbeta. The G5M1 MAb reacts only with hCGbeta, hCGbeta-CTP and intact hCG with no detectable cross-reaction with hCGalpha or any of the other glycoprotein hormones. The specificity of B12M2 MAb is very similar to G5M1, but it does not react with hCGbeta-CTP. The F4M3 MAb also has similar specificity to G5M1 and B12M2, but it strongly cross-reacts with hLH. The affinity constant (Kaff) of G5M1, B12M2 and F4M3 was found to be 4.28 x 10(9), 5.2 x 10(8), and 1.97 x 10(9) M(-1), respectively. Our results indicate that G5M1 and B12M2 MAbs are specific for hCG and recognize epitopes restricted to hCGbeta, but F4M3 recognizes a common epitope expressed both on hCGbeta and hLHbeta.
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PMID:Identification of cross-reactive and restricted epitopes localized on human chorionic gonadotropin beta-subunit by monoclonal antibodies. 1516 83

Patients with chronic pain are often challenged with depression stemming from the long-term psychophysiological effects of their condition. Consequently, patients with chronic pain are often treated with morphine, which can induce immunosuppression, along with an antidepressant. The antidepressant citalopram (CTP; Sigma-Aldrich Chemical, St. Louis, MO, U.S.A.) is a serotonin reuptake inhibitor that is reported to have immunomodulatory effects. Thus, we investigated whether CTP administration impacted immunity in morphine-treated animals. Adult mice were pretreated for 7 days with either saline or CTP (10 or 30 mg/kg intraperitoneal injections twice daily), followed by subcutaneous implantation of a 25 mg morphine pellet for 48 hours. Spleen, thymus, and lymph nodes were harvested to analyze total cell numbers, relative lymphocyte populations, and lymphocyte function. In this study, CTP had no effect on either total cell counts or lymphocyte populations in the thymus. However, in the spleen, total splenocyte numbers in all CTP-treated animals displayed an increasing trend over saline-treated animals. Interestingly, although more cells were found in the spleen, distribution of splenic lymphocyte populations did not differ between treatments. Despite no increase in total cell number, a high dose of CTP (30 mg/kg) resulted in a significantly higher B cell population in the lymph nodes, while T cell and NK cell numbers were not different. CTP did not significantly reverse morphine-induced weight loss or splenic B cell antibody secretion in vitro. Additionally, CTP treatment demonstrated a slight but not significant increase in both splenic B and T cell mitogen-induced proliferation in vitro. In summary, CTP may have a specific potential in the attenuation of morphine's immunosuppressive effect by enhancing splenocyte numbers and lymph node B cell populations.
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PMID:Citalopram enhances B cell numbers in a murine model of morphine-induced immunosuppression. 1922 15