The anatomy of the porta hepatis in patients with preduodenal portal vein,with special reference to portoenterostomy for biliary atresia

The aims of this study were to demonstrate the anatomic relationship between portal vein (PV) branches and hepatic ducts in the porta hepatis in individuals with preduodenal portal vein (PDPV) and to examine the validity of portoenterostomy (Kasai procedure) for patients with biliary atresia (BA) and PDPV. The porta hepatis of four subjects with PDPV without BA was dissected. Similar dissection supplemented by computer-aided three-dimensional reconstruction of the hilar structures was undertaken in a patient with BA and PDPV who underwent an unsuccessful Kasai procedure and died at 5 months of age. In three of the four subjects with PDPV alone, PV branches and extrahepatic bile ducts were abnormally arranged in the porta hepatis, some of the hepatic ducts entering the liver substance posterior, and occasionally lateral, to the main PV branches. The three-dimensional study showed that the original right main intrahepatic bile duct was located anterolateral to the portoenterostomy, which had been placed just anterior and to the right of the PV bifurcation. These findings strongly suggest that the PV may not be a reliable landmark for the Kasai procedure in patients with BA and PDPV.     

Coculture of mouse embryos with cryopreserved human oviduct epithelial cells

Purpose The effect of coculturing mouse embryos with cryopreserved human oviduct epithelial cells was investigated. The cryopreserved cells in Cellbanker were thawed and cultured in Richard D. Goldsby culture medium to establish monolayers. Two-cell-stage mouse embryos were cultured alone (control group) or cocultured with monolayers established from cryopreserved cells (cryopreserved coculture group) or from fresh cells (fresh coculture group). The rates of embryo development and the qualities of the blastocysts in the three groups were compared.Results The two coculture groups had significantly higher blastocyst development rates (cryopreserved coculture group, 81.6%; fresh coculture group, 82.2%) than the control group (63.1%). The two coculture groups had significantly more blastomeres (cryopreserved coculture group, 108.3 ± 25.9; fresh coculture group, 108.4 ± 25.1) than the control group (87.7 ± 31.9).Conclusion The method of cryopreservation of human oviduct epithelial cells using Cellbanker is simpler than conventional cryopreservation methods. These cryopreserved human oviduct epithelial cells may provide a constant supply of cells for coculture for in vitro fertilization and embryo transfer.     

Impaired Long-term T Cell Immunity to Epstein-Barr Virus in Patients with Nasopharyngeal Carcinoma

The long-term T cell immunity to Epstein-Barr virus (EBV) is considered to play an important role in suppressing proliferation of EBV-infected B cells and outgrowth of EBV-associated tumors. It can be manifested and quantified by the EBV-induced focus regression assay. In the present study, we examined the strength of T cell immunity to EBV in patients with nasopharyngeal carcinoma (NPC) and other cancers originating from the head and neck region. In contrast to patients with other types of cancers, including EBV-negative NPC, patients with EBV-positive NPC were found to have a profound impairment in the long-term T cell immunity to EBV.     

Recurrent Annular Erythema in a Case of Seronegative Sjögren's Syndrome

We describe a case of Sjögren's syndrome who repeatedly developed annular erythema on her extremities. Her anti-nuclear antibody, anti-SSA/Ro antibody, and anti-SSB/La antibody were all negative. Characteristics of the annular erythema included a tendency to appear on the extremities especially in summer, spontaneous regression after 1–2 weeks, and residual slight pigmentation. The histological findings revealed dermal perivascular lymphocytic infiltration admixed with some neutrophils. Slight exsudative changes were found in the upper dermis. There were no epidermal changes. This case suggests the existence of annular erythema which may not be related to the anti-SSA/Ro or anti-SSB/La antibody. Unknown factors other than those antibodies may be involved in the pathogenesis of the annular erythema.     

Characterization of a precursor T-cell line (THP-6) with rearranged T-cell receptor beta chain gene

A previously established human leukemia cell line, designated THP-6, was further characterized with respect to cell surface antigen expression and immunoglobulin(Ig) and T-cell receptor(TCR) gene status. THP-6 cells were positive for CD7 and CD5 antigens and terminal deoxynucleotidyl transferase, but negative for CD2, CD1, CD4, CD8, CD10, cytoplasmic and surface CD3 and HLA-DR antigens, suggesting a precursor T-cell line. Analysis of Ig and TCR beta chain genes revealed that THP-6 had a rearranged TCR beta chain gene and a germline Ig gene. These results, in agreement with its phenotype, confirmed that THP-6 was of the T-cell lineage.     

Role of organic anion transporting polypeptide 2 in pharmacokinetics of digoxin and beta-methyldigoxin in rats

Recently, we found that potent P-glycoprotein (P-gp) inhibitors, such as verapamil and cyclosporin A, markedly modulated the pharmacokinetics of digoxin in rats, whereas they did not affect beta-methyldigoxin pharmacokinetics significantly. Digoxin is also a substrate of rat organic anion transporting polypeptide 2 (Oatp2). Here, we compared the magnitude of Oatp2-mediated drug interaction of digoxin and beta-methyldigoxin using amiodarone as an Oatp2 inhibitor in rats. Amiodarone (20 mg/kg) given intravenously significantly increased plasma levels and decreased biliary excretion, liver distribution, and intestinal distribution of digoxin administered intravenously at a dose of 10 mug/kg. Amiodarone also significantly decreased biliary excretion and liver distribution of beta-methyldigoxin, but the change in plasma levels of beta-methyldigoxin was quite small. These findings may give a clue in selecting these cardiac glycosides in clinical pharmacotherapy for patients receiving multiple drugs towards escape from Oatp2-mediated drug interactions.     

Immunohistochemical localization of cytokeratin 19, involucrin and proliferating cell nuclear antigen (PCNA) in cultured human gingival epithelial sheets

It has been suggested that human cultured gingival epithelial sheets may serve as a possible grafting material. The purpose of this study was to examine the biological characteristics of human cultured gingival epithelial sheets by epithelial differentiation and proliferation markers. Immunohistochemical localization of cytokeratin 19, involucrin and proliferating cell nuclear antigen (PCNA) were examined in human cultured gingival epithelial sheets samples from twenty patients. Cytokeratin 19-immunopositive cells were scattered mainly in the suprabasal layer. Immunoreactivity for involucrin was observed in all layers except for the basal layer. The majority of proliferating cell nuclear antigen-immunopositive cells was found in the basal layer. These results suggested that the cultured human gingival epithelial sheets were biologically active and in proliferative condition, which implies that this biological product may be a potential grafting material.