K-Ras gene status and expression of Ras/mitogen-activated protein kinase (MAPK) signaling molecules in ameloblastomas

BACKGROUND: To clarify the roles of rat sarcoma (Ras)/mitogen-activated protein kinase (MAPK) signaling pathway in oncogenesis and cytodifferentiation of odontogenic tumors, K-Ras gene status and expression of Ras, Raf1, MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)1, and ERK1/2 proteins were analyzed in ameloblastomas as well as in tooth germs. METHODS: Paraffin sections of 10 tooth germs and 46 benign and 6 malignant ameloblastomas were examined immunohistochemically for the expression of K-Ras, Raf1, MEK1, and ERK1/2. Frozen tissue samples of 22 benign ameloblastomas and 1 malignant (metastasizing) ameloblastoma were analyzed by direct DNA sequencing to detect K-Ras gene alteration. RESULTS: Immunohistochemical reactivity for K-Ras, Raf1, MEK1, and ERK1/2 was detected in both normal and neoplastic odontogenic epithelium, and these molecules were reactive chiefly with odontogenic epithelial cells neighboring the basement membrane. Plexiform ameloblastomas showed slightly stronger expression of these Ras/MAPK signaling molecules than follicular ameloblastomas. Keratinizing cells and granular cells showed decreased reactivity for the signaling molecules. Basal cell ameloblastomas showed slightly stronger reactivity for the signaling molecules than did the other subtypes. K-Ras immunoreactivity in malignant ameloblastomas was lower than that in dental lamina of tooth germs. Direct DNA sequencing showed a GGT to GCT point mutation at codon 12 of K-Ras gene in one ameloblastoma. Conclusion: Expression of K-Ras, Raf1, MEK1, and ERK1/2 in tooth germs and ameloblastomas suggests that Ras/MAPK signaling pathway functions to regulate cell proliferation and differentiation in both normal and neoplastic odontogenic epithelium. K-Ras gene status implied that K-Ras mutations might play a minor role in oncogenesis of odontogenic epithelium.     

Long-Term Outcome of Adult-to-Adult Living Donor Liver Transplantation for Post-Kasai Biliary Atresia

Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage.     

Phenotypic and genetic analyses of T-cell-mediated immunoregulation in patients with Type 1 diabetes.

AIMS: To investigate the contribution of regulatory T cells and co-stimulatory molecules in CD4(+) T cells to the development of Type 1 diabetes (T1D). METHODS: Twelve patients with T1D, nine patients with systemic lupus erythematosus (SLE), and 12 age-matched healthy control subjects participated. We analysed the proportions of CD25(+)CD4(+) T cells and natural killer T cells (NKT cells), and the expression levels of Foxp3, CTLA-4, CD28, ICOS, PD-1 and BTLA in peripheral blood mononuclear cells and purified CD4(+) T cells. RESULTS: There were no significant differences in the proportions of CD25(+) CD4(+) T cells or NKT cells among the three groups. PD-1 expression levels of peripheral CD4(+) T cells from T1D patients were significantly lower than those from healthy control subjects (P = 0.00066). In contrast, PD-1 expression levels were similar in SLE patients and healthy control subjects. The expression levels of Foxp3, CTLA-4, CD28, ICOS and BTLA were similar in the three groups. CONCLUSIONS: Decreased expression of the PD-1 gene in CD4(+) T cells may contribute to the development and/or maintenance of autoimmune T1D. As the population studied was small and heterogeneous, further studies are required to confirm the findings.     

Classification of human liver transplant recipients by their preoperative CD8+ T cell subpopulation and its relation to outcome.

The primed status of T cells is markedly different among liver transplant recipients, due to a lifetime of antigen exposure and reduced thymopoiesis by aging, and diseases. This study aims to characterize the preoperative immunological status of CD8+ T cell subpopulations and relate it to the outcome for liver transplant recipients. We classified 112 liver transplant recipients into 5 groups, based on hierarchical clustering of the CD8+CD45 isoform proportion of T cells. In Groups I and II (pediatric), the naive T cell proportion was more than 50%. In adult recipients, Group III was characterized by a naive T cell proportion of 50%, Group IV had the greatest effector/memory T cells (EM), and Group V had the greatest proportion of effector T cells. In Groups IV and V, the effector T cell proportion was considerably higher, and was accompanied by marked downregulation of the CD27+CD28+ subsets and upregulation of interferon gamma (IFN)-gamma, tumor necrosis factor-alpha, and perforin expression. Group V recipients tended to be complicated postoperatively, with a significantly reduced survival rate (1 yr, 66.8%) and markedly reduced Eastern Cooperative Oncology Group performance status.     

The effects of intranasal application of low dose buserelin in women with hypothalamic amenorrhea]

Low doses of the Gn-RH agonist (buserelin, 30 micrograms) were given intranasally to 14 women with clomiphene ineffective hypothalamic amenorrhea three times daily for three weeks in order to study pituitary responses and to induce follicular maturation and ovulation. Clomiphene ineffective hypothalamic amenorrhea patients were classified into two groups by LH-RH stimulation test before the treatment. Group 1 was defined as having basal serum LH and FSH levels lower than 1.5 mIU/ml, LH and FSH peaks lower than 3mIU/ml by LH-RH stimulation test. Group 2 consisted of cases other than those in Group 1. While a significant increase in basal LH and FSH (p less than 0.01, p less than 0.001) and improvement in pituitary response to LH-RH stimulation test were observed in group 1, the basal levels of LH and FSH did not increase significantly and pituitary response to a LH-RH stimulation test was decreased in group 2. It is suggested that pituitary priming occurred in group 1 and pituitary desensitization occurred in group 2. None of 14 patients showed signs of follicular maturation during or after the treatment. The results demonstrated that the biphasic pituitary response to intranasal buserelin spray and the limit of its therapeutic use for the treatment of hypothalamic amenorrhea.     

Expression of EGF receptors in cell lines derived from female genital cancers and enhancement of the therapeutic effect of anticancer drugs by EGF]

Manifestation of EGF receptors and enhancement of an anticancer agent by EGF were studied in cultured cells derived from female genital cancers. 1) The numbers of EGF-receptors of SKG-3a, RMUG-s, HUOA, A-431 and HEC-1 were 1.22 x 10(4), 6.94 x 10(4), 2.75 x 10(4), 5.25 x 10(5) and 0.92 x 10(4) sites per cell respectively. The values for the dissociation constant (Kd) of RMUG-s, SKG-3a, HUOA and HEC-1 were 340pM, 477pM, 989pM and 2,187pM, respectively. 2) All cell lines were stimulated by EGF at low concentrations and inhibited at higher concentrations. The growth stimulation rates for SKG-3a, HEC-1, HUOA and RMUG-s in the presence of 0.01 nM EGF at 48 hours were 8, 18, 21.1 and 3.7%, respectively. The growth inhibition rates for SKG-3a, A-431, HEC-1, HUOA and RMUG-s in the presence of 1.0 nM EGF at 48 hours were 32, 28, 25.8, 11.2 and 6.8%, respectively. 3) The antitumor effect of CDDP was enhanced by the presence of EGF at both a concentration of 0.01 nM (except for A-431) and a concentration of 1.0 nM, in all cell lines. 4) EGF receptors of RMUG-s and HUOA were decreased by CDDP. The values for RMUG-s and HUOA were 1.71 x 10(4), 0.52 x 10(4) (CDDP 0.4 microgram/ml) and 0.95 x 10(4), 0.29 x 10(4) sites per cell (CDDP 2.0 micrograms/ml), respectively. The effect of CDDP on EGF receptors was not recognized in SKG-3a and HEC-1. In brief, EGF receptors were significantly expressed in cell lines derived from female genital cancers.(ABSTRACT TRUNCATED AT 250 WORDS)