Idiopathic presacral retroperitoneal fibrosis: report of two cases

Retroperitoneal fibrosis is characteristic plaques of dense fibrous tissue, typically extending from the level of the kidney down to the sacral promontory. Involvement of the presacral space is extremely rare in retroperitoneal fibrosis. We report two cases of idiopathic retroperitoneal fibrosis manifested by a presacral mass.

Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF 3

A porcine epidemic diarrhea virus (PEDV) designated DR13 was isolated in Vero cells and serially passaged by level 100. The virus was titrated at regular intervals of the passage level. Open reading frame (ORF) 3 sequences of the virus at passage levels 20, 40, 60, 80, and 100 were aligned and compared using a computer software program. Suitability of the restriction fragment length polymorphism (RFLP) analysis for differentiating the virus from other Korean field strains was investigated. The DR13 field isolate was successively adapted in Vero cells as observed through polymerase chain reaction (PCR) and titration of the virus. RFLP analysis identified change in cleavage sites of HindIII and Xho II from passage levels 75 and 90, respectively; these RFLP patterns of ORF 3 differentiated the Vero cell-adapted virus from its parent strain, DR13, and 12 other strains of PEDV studied. The cell adapted DR13 was tested for its pathogenicity and immunogenicity in piglets and pregnant sows. The results indicated that cell adapted DR13 revealed reduced pathogenicity and induced protective immune response in pigs. Differentiation between highly Vero cell-adapted virus and wild-type virus could be the marker of adaptation to cell culture and a valuable tool for epidemiologic studies of PEDV infections. The results of this study supported that the cell attenuated virus could be applied as a marker vaccine candidate against PEDV infection.

Median nerve somatosensory evoked potentials and upper limb motor function in hemiparesis

The purpose of this study is to describe the relationship between median nerve somatosensory evoked potential (SEP) parameters and clinical measures of motor impairment and physical disability in the affected upper limb of patients with hemiparesis. SEP assessments were carried out in 28 long-term survivors of stroke. Stroke survivors with preserved SEPs over the affected hemisphere exhibited significantly lower motor impairment and physical disability than those with absent waveforms. Among those with preserved waveforms, SEP amplitude exhibited a weak correlation with degree of upper limb motor impairment. The correlation between SEP amplitude and physical disability was not statistically significant. Contrary to prior reports, median nerve SEP appears to have a weak correlational relationship with clinical measures of upper limb function in hemiparesis.

Hypersensitivity reactions to carbamazepine: characterization of the specificity, phenotype, and cytokine profile of drug-specific T cell clones

Administration of carbamazepine (CBZ) causes hypersensitivity reactions clinically characterized by skin involvement, eosinophilia, and systemic symptoms. These reactions have an immune etiology; however, the role of T cells is not well defined. The aim of this study was to characterize the specificity, phenotype, and cytokine profile of CBZ-specific T cells derived from hypersensitive individuals. Proliferation of blood lymphocytes was measured using the lymphocyte transformation test. CBZ-specific T cell clones were generated by serial dilution and characterized in terms of their cluster of differentiation and T cell receptor V beta phenotype. Proliferation, cytotoxicity, and cytokine secretion were measured by [(3)H]thymidine incorporation, (51)Cr release, and enzyme-linked immunosorbent assay, respectively. HLA blocking antibodies were used to study the involvement of antigen-presenting cells. The specificity of the drug T cell receptor interaction was studied using CBZ metabolites and other structurally related compounds. Lymphocytes from hypersensitive patients (stimulation index: 32.1 +/- 24.2 [10 microg ml(-1)]) but not control patients (stimulation index: 1.2 +/- 0.4 [10 microg ml(-1)]) proliferated upon stimulation with CBZ. Of 44 CBZ-specific T cell clones generated, 10 were selected for further analysis. All 10 clones were either CD4+ or CD4+/CD8+, expressed the alpha beta T cell receptor, secreted IFN-gamma, and were cytotoxic. T-cell recognition of CBZ was dependent on the presence of HLA class II (DR/DQ)-matched antigen-presenting cells. The T cell receptor of certain clones could accommodate some CBZ metabolites, but no cross-reactivity was seen with other anticonvulsants or structural analogs. These studies characterize drug-specific T cells in CBZ-hypersensitive patients that are phenotypically different from T cells involved in other serious cutaneous adverse drug reactions.

Are chemically reactive metabolites responsible for adverse reactions to drugs?

Low molecular weight organic chemicals can be transformed by normal drug-metabolising systems into short-lived metabolites that are inherently reactive towards cellular macromolecules. There is direct evidence that the formation of such chemically reactive metabolites may lead to mutagenesis, carcinogenicity, apoptosis and necrosis in both cell and animal models. A number of drugs associated with non-pharmacological drug toxicities in man have been shown to undergo bioactivation either in vivo or in vitro. We have therefore examined the evidence for the role of reactive metabolites in the three most common drug-induced toxicities: hepatotoxicity, skin reactions and blood dyscrasias.

Encephalomyelitis associated with akabane virus infection in adult cows

Between August and September 2000, five 2-7-year-old cows in Korea exhibited neurologic signs and were diagnosed as infected with Akabane virus based on the results of histopathology, immunohistochemistry, serology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemistry and RT-PCR were equally effective and sensitive for diagnosing Akabane virus infection during the early stage of infection. Typical lymphohistiocytic inflammation characterized by perivascular mononuclear cell infiltration, gliosis, neuronophagia, and neuronal loss was noted in the brain and the ventral horn gray matter of the spinal cord. The lesions in the brain were most prominent in the pons and medulla oblongata. Akabane virus antigen was detected in the brain and spinal cord, mainly in degenerating neurons and glial cells. RT-PCR analysis revealed a target band of expected size in four cows. This is the first report on an outbreak of natural Akabane virus infection in adult cattle.

Prevalence of porcine reproductive and respiratory syndrome virus, porcine circovirus type 2 and porcine parvovirus from aborted fetuses and pigs with respiratory problems in Korea

Porcine reproductive and respiratory syndrome virus(PRRSV)0, porcine circovirus type 2(PCV-2) and porcine parvovirus (PPV)0 infections were investigated as possible causes of the postweaning multisystemic wasting syndrome(PMWS). Specific primers for RT-PCR and PCR were designed for the differential detection of PRRSV, PCV-2 and PPV. Using PCR, these viruses were detected in homogenized tissue samples from pigs that had respiratory of reproductive problems in the time period between 1998 and 2000; the overall prevalences were: PRRSV 31.4%, PCV-2 46.5%, and PPV 8.1%. PCV-2 was also detected in aborted fetal tissues.

Implication of co-measured platelet factor 4 in the reliability of the results of the plasma transforming growth factor-beta 1 measurement

We examined the possible alteration of circulating transforming growth factor-beta1 (TGF-beta1) concentrations in a time-dependent fashion in human plasma. Plasma TGF-beta1 was measured three times at 2 week-intervals from each of 12 healthy participants. Platelet factor 4 (PF4) was measured in parallel with TGF-beta1 to estimate the degree of platelet degranulation. TGF-beta1 levels of the second and third plasma samples, in which PF4s were measured as < approximately 1000 IU/ml, were relatively low and fell in a narrow range. However, TGF-beta1 levels of the first samples, in most of which PF4s were > approximately 1000 IU/ml, appeared much higher and more variable than those of the second or third samples. These results indicate that the platelet degranulation accounted for the higher TGF-beta1 levels in the first samples, and thus did not support our initial assumption. We, nevertheless, could propose a useful guidance in the assessment of TGF-beta1 levels in plasma. When the PF4 level is measured as < approximately 1000 IU/ml under our assay conditions, the TGF-beta1 level in a given plasma sample might be accepted as a reliable value considering the effect of platelet degranulation on TGF-beta1 level.

LC determination of carbamazepine in murine brain

A reversed phase HPLC method for the determination of carbamazepine (CBZ) in the brain of adult mice is described. CBZ was recovered from murine brain by solvent-extraction with ethyl acetate and resolved from imipramine (internal standard) and brain endogenous material using a Lichrospher RP select B column with a linear gradient of acetonitrile (40-80 v/v, 25 min) in ammonium acetate buffer (25 mM, pH 4.0) with UV detection at 285 nm. The method is selective, reproducible and precise with a limit detection of 45 ng/ml and is suitable for the determination of CBZ in murine brain after intra-peritoneal administration.

Differential detection of transmissible gastroenteritis virus and porcine epidemic diarrhea virus by duplex RT-PCR

Transmissible gastroenteritis (TGE) and porcine epidemic diarrhea (PED) are highly contagious enteric diseases of piglets. The clinical signs of these diseases are very similar and include watery, yellowish diarrhea. Thus, the effective differential detection of TGE virus and PED virus is required. In the present study, a duplex reverse transcription-polymerase chain reaction (RT-PCR) was established for the differential detection of TGE and PED viruses. The primers were designed for the S gene of each virus. RNA was extracted from the intestines and stool samples that were collected from the swine with diarrhea. The RT-PCR test could detect both TGE and PED viruses with 2 TCID50/200 microl. Among 90 clinical samples, 7 TGE viruses and 2 PED viruses were detected by the duplex RT-PCR. This duplex RT-PCR may be a useful diagnostic method for the rapid, specific, and sensitive differential detection of TGE and PED viruses using clinical samples.

Akt1 induces extracellular matrix invasion and matrix metalloproteinase-2 activity in mouse mammary epithelial cells

The roles of the protein-serine/threonine kinase, Akt1, in signaling pathways associated with cell motility and extracellular matrix invasion were examined in the immortalized mouse mammary epithelial cell line, COMMA-1D. COMMA-1D cells were engineered to express the avian leukosis subtype A receptor, tv-a, to permit infection by recombinant avian leukosis virus produced by the replication-competent avian splice vector, RCAS. COMMA-1D/tv-a cells transduced with RCAS/v-akt, but not RCAS/Akt1, formed anchorage-independent colonies in soft agar; however, cells overexpressing either v-akt or Akt1 became highly invasive when grown on the ECM, Matrigel. Zymography of extracellular protease activity shed into the medium by COMMA-1D/Akt1 or COMMA-1D/v-akt cells revealed elevated gelatinase activity that was confirmed to be matrix metalloproteinase-2 (MMP-2; gelatinase A) by Western blotting and immunoprecipitation-zymography. The MMP inhibitor, BB-94, blocked MMP-2 activity and invasion associated with Akt1- and v-akt-expressing cells. The proteasome inhibitor, lactacystin, markedly increased MMP-2 levels and invasion in control cells but not in Akt1- and v-akt-expressing cells. These results suggest that the invasive behavior of mammary epithelial cells induced by Akt1 is associated with increased MMP-2 expression that may result from inhibition of MMP-2 degradation by the proteasome pathway.

Expression and regulation of mouse Mtsh1 during limb and branchial arch development

The mouse genome contains at least two genes, Mtsh1 and Mtsh2, related in sequence to the Drosophila homeotic gene teashirt (tsh). In this paper, we report the characterization of Mtsh1 expression in the developing branchial arches and forelimbs during mouse embryogenesis. Mtsh1 was found predominantly transcribed in the mesenchymal tissue of branchial arches and forelimbs. Surgical removal of the epithelium of both forelimb and branchial arch significantly decreased the expression of Mtsh1 in the mesenchymal cells of these tissues. Upon implantation of FGF8-soaked beads into arches and limbs, Mtsh1 transcription was up-regulated. In contrast, when BMP4-soaked beads were implanted, Mtsh1 expression was inhibited. Together, these results suggest that mouse Mtsh1 gene may be involved in the outgrowth of limbs and arches and may be functioning downstream of BMP and FGF signaling pathways.

Polymorphisms in the TNF-alpha and TNF-receptor genes in patients with coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is both multifactorial and polygenic in nature. Atheroma formation, the pathological hallmark of CAD, is an inflammatory process, with pro-inflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha), having a major role in its pathogenesis. We have therefore investigated whether polymorphisms in the TNF-alpha (- 238 and - 308), TNF receptor 1 (position - 609 and + 10, intron 6) and TNF receptor 2 (position + 422, codon 198) genes show an association with CAD.

MATERIALS AND METHODS

Patients with angiographically proven single vessel (n = 58) and multivessel (n = 122) CAD were compared to patients with angiographically proven normal coronary arteries (n = 79) and volunteers without clinical evidence of CAD (n = 250). Genotyping was performed by PCR-RFLP analysis. For the TNF-alpha polymorphisms, a meta-analysis of all published studies was also undertaken.

RESULTS

No significant differences in allele or genotype frequencies were found between the normal coronary artery group or healthy volunteers and patients with CAD for any of the polymorphisms. There was also no difference in allele frequency between patients with single- and multivessel disease. For the - 308 and - 238 TNRalpha gene polymorphisms, a meta-analysis of our data and previously published studies failed to demonstrate any significant association with CAD.

CONCLUSIONS

Polymorphisms in the TNF-alpha promoter region and TNF-receptor genes are not associated with the development of CAD.

Inhibition of TPA-induced cyclooxygenase-2 expression and skin inflammation in mice by wogonin, a plant flavone from Scutellaria radix

Wogonin (5,7-dihydroxy-8-methoxyflavone), isolated from Scutellaria radix, was previously reported to inhibit the expression and activity of the enzyme cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated cells of a mouse macrophage cell line, RAW 264.7. Here, in order to find in vivo effects, inhibition by wogonin of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cyclooxygenase-2 expression and anti-inflammatory activity in vivo were investigated. When applied topically to the dorsal skin of mice, wogonin at doses of 50-200 microg/site/treatment (total of five treatments in 3 days) inhibited cyclooxygenase-2 expression and prostaglandin E2 production induced by multiple treatments with TPA. At 200 microg/site/treatment, wogonin caused a 55.3% reduction of prostaglandin E2 production on the dorsal skin compared with an increased production in the TPA-treated control group. The same compound significantly inhibited mouse ear edema induced by TPA in both preventive (58.1% inhibition) as well as curative treatment (31.3% inhibition) schedules at 200 microg/ear/treatment. Inhibition of neutrophil infiltration was also observed. Therefore, wogonin may be beneficial for cyclooxygenase-2-related skin disorders.

HIV and drug allergy

Drug-related rashes have been estimated to be 100 times more common in HIV-positive patients than in the general population. The reasons for this are not clear, but are likely to be multifactorial, and include changes in drug metabolism, oxidative stress, cytokine profiles and immune hyperactivation. HIV itself may also serve as a danger signal, leading to the development of an immune response rather than tolerance. Drugs that are implicated in causing hypersensitivity have changed since the advent of highly active antiretroviral therapy. This is largely as a result of a decrease in the use of antimicrobials such as co-trimoxazole, and the introduction of new drugs of different classes, including abacavir, non-nucleoside reverse transcriptase inhibitors such as nevirapine, and protease inhibitors such as amprenavir. Laboratory evidence supporting a role of the immune system in the mechanism of co-trimoxazole hypersensitivity is available. However, this is not the case for the newer antiretrovirals; hypersensitivity to these agents is presumed to be immune-mediated based only on the symptomatology. It is essential that research be carried out into the mechanisms of hypersensitivity reactions associated with these important new classes of drugs so that their benefit-risk ratio can be improved, and lessons learned for future drug development.

Reactive metabolites and their role in drug reactions

Adverse drug reactions are a major clinical problem and often preclude drug administration. Drug hypersensitivity (or allergy) represents one of the most severe and unpredictable reactions associated with drug therapy. Our current understanding of drug hypersensitivity is based on the hapten hypothesis of immune recognition of drugs by T cells. The onset of hypersensitivity involves drug bioactivation, covalent binding, followed by uptake, antigen processing and T cell proliferation. There is convincing evidence that drugs associated with a high incidence of hypersensitivity are converted to protein reactive intermediates by the normal processes of drug metabolism and stimulate a cellular immune response in sensitive individuals. Until recently, however, there has been little evidence to relate the formation of a reactive metabolite to the initiation of a cellular immune response. The purpose of this review is to detail recent advances in our understanding of the complex mechanisms of drug hypersensitivity, and using severe skin reactions as an example, assess recent evidence that supports the hapten hypothesis of drug hypersensitivity.

Enzyme-induction dependent bioactivation of troglitazone and troglitazone quinone in vivo

Troglitazone (TGZ), a 2,4-thiazolidinedione antidiabetic, causes hepatotoxicity in 1.9% of patients. TGZ is an inducer of, and substrate for, hepatic P450 3A. Microsomal metabolism yields a benzoquinone (TGZQ) and reactive intermediates. Kassahun et al. [Kassahun et al. (2001) Chem. Res. Toxicol. 14, 62-70] have trapped the intermediates as thioester, thioether, and disulfide conjugates of glutathione and found five conjugates in rat bile. The thioether was substituted in the chromane moiety. We have investigated the effect of the P450 3A inducer, dexamethasone (DEX), on metabolism of TGZ and TGZQ in rats and assessed the compounds' cytotoxicity. TGZ-glucuronide and sulfonate were confirmed as principal biliary metabolites of TGZ (50 mg/kg, iv). Bile from noninduced animals also contained a TGZ-glutathione thioether adduct (ML3) but it was substituted in the thiazolidinedione moiety. Pretreatment with DEX (50 mg/kg/day for 3 days) resulted in a 2-5-fold increase in the biliary concentration of ML3 and a 2-fold increase in the concentration of TGZQ, which was commensurate with the induction of hepatic P450 3A. Three of the known glutathione-conjugated metabolites were also found. TGZQ (50 mg/kg, iv) was metabolized to an analogue of one of the TGZ-glutathione thioesters and a glutathione adduct of TGZQ hydroquinone after DEX pretreatment. TGZ quinol glucuronide was a biliary metabolite of TGZ and TGZQ. Its formation would represent deactivation of TGZQ. TGZ was toxic to rat hepatocytes and Hep-G2 cells at concentrations exceeding 50 and 25 microM, respectively, after 24 h. In contrast, TGZQ was nontoxic to rat hepatocytes and toxic to Hep G2 cells only at concentrations exceeding 100 microM. Our results show that TGZQ as well as TGZ yields reactive metabolites in vivo, and that bioactivation is enhanced by induction of P450 3A. However, hepatotoxicity is unlikely to be due to either TGZQ or its metabolites.

Metabolism of fluorine-containing drugs

This article reviews current knowledge of the metabolism of drugs that contain fluorine. The strategic value of fluorine substitution in drug design is discussed in terms of chemical structure and basic concepts in drug metabolism and drug toxicity.

Genetic susceptibility to adverse drug reactions

Adverse drug reactions (ADRs) are a major clinical problem. Genetic factors can determine individual susceptibility to both dose-dependent and dose-independent ADRs. Determinants of susceptibility include kinetic factors, such as gene polymorphisms in cytochrome P450 enzymes, and dynamic factors, such as polymorphisms in drug targets. The relative importance of these factors will depend on the nature of the ADR; however, it is likely that more than one gene will be involved in most instances. In the future, whole genome single nucleotide polymorphism (SNP) profiling might allow an unbiased method of determining genetic predisposing factors for ADRs, but might be limited by the lack of adequate numbers of patient samples. The overall clinical utility of genotyping in preventing ADRs needs to be proven by the use of prospective randomized controlled clinical trials.

Efficient preparations of the beta-glucuronides of dihydroartemisinin and structural confirmation of the human glucuronide metabolite

New and greatly improved preparations of the 12alpha,1'beta- (5) and 12beta,1'beta- (6) glucuronides of dihydroartemisinin (DHA, 2) are reported using anomeric hydroxy and imidate glucuronate intermediates. Comparison of the synthetic and natural materials shows that the human metabolite of DHA is the 12alpha-epimer 5.

TNFalpha promoter region gene polymorphisms in carbamazepine-hypersensitive patients

OBJECTIVE

To evaluate whether the major histocompatibility complex contains susceptibility genes for carbamazepine hypersensitivity. Carbamazepine hypersensitivity is immune-mediated, although factors determining its occurrence and severity are unknown.

METHODS

Using PCR in 60 carbamazepine-hypersensitive patients, 37 with nonserious (Group I) and 23 with serious (Group II) reactions, and 313 control subjects (63 patients on carbamazepine without adverse effects and 250 healthy volunteers), the association with polymorphisms in the promoter region of the tumor necrosis factor alpha (TNFalpha) gene (positions -308 and -238), and with HLA-DR3 and -DQ2 was determined.

RESULTS

The frequency of the variant allele (TNF2) at the -308 position was increased in Group II but not Group I carbamazepine-hypersensitive patients compared with all control subjects (p = 0.01; OR = 2.4), as was the frequency of HLA-DR3 (p = 0.01; OR = 3.3), HLA-DQ2 (p = 0.04; OR = 2.7), and the TNF2-DR3-DQ2 haplotypes (p = 0.02; OR = 3.2). None of the alleles were independently associated with serious carbamazepine hypersensitivity. For the -238 polymorphism, there was a difference in the genotype, but not in the allelic, frequencies between Group II hypersensitive patients and all control subjects.

CONCLUSIONS

The TNF2 allele was associated with severe, but not nonserious, carbamazepine hypersensitivity reactions, suggesting that hypersecretion of tumor necrosis factor alpha may be a determinant of the severity of tissue damage. However, the association of the TNF2 allele with carbamazepine hypersensitivity was not independent of HLA-DR3 and -DQ2, and therefore the possibility that it constitutes a passive component of the TNF2-DR3-DQ2 haplotype cannot be excluded.

Carbamazepine is not a substrate for P-glycoprotein

AIMS

To determine whether the anticonvulsant carbamazepine (CBZ), a known CYP3A4 substrate, is also a substrate for the multidrug efflux transporter P-glycoprotein (Pgp).

METHODS

The role of Pgp in the transport of CBZ was assessed in three systems: (a) in mdr1a/1b(-/-) and wild-type mice after administration of 2 mg kg-1 and 20 mg kg-1, which served as a model for brain penetration; (b) in Caco-2 cells, an in vitro model of the intestinal epithelium that is known to express high Pgp levels; and (c) by flow cytometry in lymphocytes using rhodamine 123, a fluorescent substrate for PgP.

RESULTS

Brain penetration of both doses of CBZ at 1 h and 4 h was comparable in wild-type and mdr1a/1b(-/-) mice. Transport across the Caco-2 cell monolayer was Pgp-independent, and was not affected by the Pgp inhibitor PSC-833. CBZ had no effect on rhodamine 123 efflux from lymphocytes, in contrast to verapamil, which increased fluorescence intensity fivefold.

CONCLUSION

CBZ is not a substrate for Pgp. Its efficacy is unlikely to be affected by Pgp over-expression in the brain. Furthermore, the interaction of CBZ with drugs that modulate both CYP3A4 and Pgp function such as verapamil is probably due to inhibition of CYP3A4 and not Pgp.

Incidence and characterization of Listeria spp. from foods available in Korea

A total of 410 domestic Korean food samples were analyzed for the presence of Listeria spp. by the conventional U.S. Department of Agriculture protocol, and presumptive strains were identified by morphological, cultural and biochemical tests according to Bergey's manual and confirmed by API-Listeria kit. Among the total 410 food samples, 46 samples (11.2%) were found to be contaminated with Listeria species. Among the 46 strains of Listeria spp. isolates, 8 strains (17.42%) for Listeria monocytogenes, 3 strains (6.5%) for Listeria seeligeri, 33 strains (71.7%) for Listeria innocua, and 2 strains (4.4%) for Listeria welshimeri were identified, respectively. Also, only beef, chicken, pork, frozen foods, and sausage were contaminated with L. monocytogenes, and the other products were free of L. monocytogenes. Of 46 Listeria spp. isolates, L. innocua (71.7%) was the most predominantly isolated in a variety of foods compared to other Listeria spp. An in vitro virulence assay for Listeria spp. using myeloma and hybridoma cells from murine and human sources was performed. The result showed that only L. monocytogenes killed approximately 95 to 100% hybridoma cells after 6 h and the other Listeria species, such as L. innocua, L. seeligeri, and L. welshimeri strains had about 0 to 10% lethal effect on hybridoma cells. Also, an antibiotic susceptibility test showed that Listeria spp. isolates were very susceptible to the antibiotics tested, except for nalidixic acid. Also, serotyping results showed 75% of L. monocytogenes isolates from beef, chicken, and frozen pizza belonged to serotype 1 and 25% from sausage were type 4.

Immunostimulatory effects of anionic alkali mineral complex solution Barodon in porcine lymphocytes

The anionic alkali mineral complex solution, Barodon (Barodon-S.F. Corp., Korea), was evaluated for its effectiveness as a nonspecific immunostimulator in pigs. The effects of Barodon were determined by analysis of feed efficiency, growth rate, and phenotype of leukocyte subpopulations using monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry (FC). The study was focused to investigate the change in proportion of the CD4+CD8+ double positive T lymphocyte subpopulation (dpp) which exists uniquely in pigs. In addition, the mitogen-stimulated lymphoproliferative response, tissue distribution in lymphoid organs and the adjuvant effect of Barodon on hog cholera vaccine efficiency were determined. The study has revealed the average daily gain rates and feed conversion rates were significantly (p<0.05) improved in either group of pigs fed with 0.05% Barodon-spray feed (Tx-1) or pigs fed with 3% Barodon-fermented feed (Tx-2) in comparison with group of pigs fed with feed containing no Barodon (control). The proportion of cells expressing CD4+ antigen in Barodon-treated group increased from 3 weeks posttreatment and was significantly higher (p<0.05) than that of control at 8 weeks posttreatment. Particularly, the significantly higher proportion was maintained from 8 weeks through 13 weeks posttreatment in Tx-1 group (p<0.05). The proportion of cells expressing CD8+ antigen was significantly higher at 3 weeks posttreatment in Tx-2 (p<0.01). Proportion of MHC class II-expressing cells was significantly higher in Tx-1 and Tx-2 group at 11 weeks and 8 weeks posttreatment (p<0.05), respectively. In addition, the proportion of Non T/Non B (N) cells was also significantly higher in Tx-2 at 3 weeks posttreatment (p<0.01) and maintained to 13 weeks posttreatment (p<0.1). Between Barodon-treated groups, the proportion of MHC class II-expressing cells was observed to be larger in Tx-2 than Tx-1 from 3 weeks to 8 weeks posttreatment (p<0.05). However, there were no significant difference in the proportions of CD2+ cells, B cells, monocytes and granulocytes between Barodon-treated and control group during the experiment. Dual-color FC analysis, study has revealed an increased proportion of dpp present in lymphocytes obtained from peripheral blood (PB) and mesenteric lymph node (MLN) of Barodon-treated group at 8 and 11 weeks posttreatment. The proportion of dpp in PB was 27.5% and 32.1% in Tx-1 and Tx-2, respectively, but only 2.2% in control group at 8 weeks posttreatment. In MLN, the proportion was 45.1% and 52.1% in Tx-1 and Tx-2, respectively, otherwise 16.5% in control group at 8 weeks posttreatment. The mitogen-stimulated activity was significantly higher in Tx-1 than in the control group at 11 weeks posttreatment when cells were stimulated with Con A and PHA, respectively (p<0.01). Also, Con A-, PHA and PWM-stimulated activity was significantly higher in Tx-2 than in the control group at the same time (p<0.05). The tissue distribution of CD4+, CD8+ and CD4+CD8+ dpp in MLN and spleen was significantly larger in Tx-1 and Tx-2 than in the control group (p<0.01). Also, a larger proportion of dpp was observed in Tx-2 than Tx-1 in spleen between Barodon-treated groups (p<0.01). In conclusion, the study has demonstrated that Barodon had an immunostimulatory effect on pigs through proliferation and activation of porcine immune cells, specially CD4+CD8+ dpp lymphocytes.

Comparison of the modulatory effects of human and rat liver microsomal metabolism on the estrogenicity of bisphenol A: implications for extrapolation to humans

Bisphenol A [BPA, 2,2-bis(4-hydroxyphenyl)propane], a xenoestrogen, is a monomer for the synthesis of polycarbonate plastics, epoxy resins, and composites. Metabolism of BPA to the monoglucuronide will determine the extent of its estrogenicity in vivo. Investigation of the metabolism of BPA (500 microM) by isolated female rat hepatocytes confirmed the formation of BPA glucuronide as the major metabolite. There was a significant difference (p < 0.05) between the V(max) (mean +/- S.E.M., n = 4) of glucuronidation by pooled male or female human (four livers in each case) and immature female rat liver microsomes (5.9 +/- 0.4, 5.2 +/- 0.3, and 31.6 +/- 8.1 nmol/min/mg of protein, respectively). Estrogenic activity of BPA, assessed in a coupled microsomal metabolism-yeast estrogenicity assay, was decreased 3- and 7-fold following glucuronidation by human female and immature female rat liver microsomes, respectively. Incubations of BPA with pooled human or rat liver microsomes, in the presence of NADPH, resulted in the formation of 5-hydroxybisphenol A [2-(4,5-dihydroxyphenyl)-2-(4-hydroxyphenyl)propane], which was 10-fold less potent than BPA in the yeast estrogenicity assay. However, there was insufficient turnover to achieve a significant effect on the estrogenic activity of BPA. Because human liver microsomes did not glucuronidate BPA as extensively as the rat liver microsomes, estrogen target tissues in humans may be subject to greater exposure to BPA than the tissues of the immature female rats used for assessing estrogenicity of xenobiotics.