Search PubMed⌕ Search

Biomedical subjects

S Tashiro

Publications and source records attributed to S Tashiro.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Problems of living-related partial liver transplantation to adult patients].

Here, we describe the clinical course of an adult patient who had living-related liver transplantation (LRLT) from a donor with Gilbert's syndrome and problems of living-related liver transplantation to adult patients. A 22-year-old woman had been diagnosed as having liver cirrhosis at the age of 5. She had undergone devascularization and transsection of the esophagus, and splenectomy for esophageal varices at the age of 8. Complications such as spontaneous bacterial peritonitis and nonspecific colitis sometimes appeared from 17 years old, and icterus and ascites had appeared on all such occasions. Such complications had frequently occurred from 21 years old. Total bilirubin was 5.5 mg/dl and direct bil. was 4.2 mg/dl. The patient and her family members were informed that LRLT might be possible, and they indicated that the patient's 57-year old father was willing to act as the donor. His liver function was examined. His hepatic function was normal except for hyperbilirubinemia (T. Bil. 2.3 mg/dl, D. Bil. 0.3 mg/dl). He was diagnosed with Gilbert's Syndrome because of an increase of unconjugated bilirubin levels during low caloric intake and nicotinic acid test. The standard liver volume for the patient was calculated to be 900 ml on the basis of body weight. Volumetric analysis with computed tomography revealed that the left lobe volume of the donor's liver was 512 ml, corresponding to 56% of the recipient standard liver volume. This proposal was submitted to the ethical committee of Tokushima University School of Medicine and was accepted. In March 28, 1995, the patient underwent LRLT with the donor's left lobe as the graft. The graft weight was 440 g and the graft corresponded to 49% of the recipient's standard liver volume. Volumetric analysis showed rapid enlargement of graft to 683 ml as early as one week after the operation. The donor has returned to work after discharge from the hospital. The recipient is well 11 months after surgery. Total bilirubin was 1.8 mg/dl and D. Bil 0.5 mg/dl. LRLT may become an option for adult recipients, if graft of more than 30% of the recipient standard liver volume is transplanted even from a donor with Gilbert's syndrome.

Adult↗
PubMed1996

Analysis of c-Ki-ras oncogene and p53 immunocytochemistry in the gallbladder mucosa of an experimental dog model of anomalous arrangement of the pancreaticobiliary ducts.

Anomalous arrangement of the pancreaticobiliary ducts is a congenital condition which predisposes the affected person to biliary tract carcinoma. We developed an experimental dog model of anomalous arrangement of the pancreaticobiliary ducts to investigate the mechanism of carcinogenesis in this condition. We used this model to analyze point mutations in the c-Ki-ras gene, and to assess the expression of mutant p53 protein in the gallbladder mucosa. The histopathological appearance of the gallbladder mucosa was also examined. Glandular structures were seen in four of seven (57%) gallbladders examined 14 months after the surgical creation of an anastomosis between the gallbladder and the pancreatic duct. Goblet cells were seen in two of seven gallbladders (29%). However, dot-blot hybridization and immunohistochemical study did not reveal any mutations in the c-Ki-ras gene, or any over-expression of the p53 protein in the specimens. These results show that the gallbladder mucosa is damaged by refluxing pancreatic juice in this dog model of anomalous arrangement of the pancreaticobiliary ducts, but that severe damage may be necessary to induce mutations in the c-Ki-ras proto-oncogene, or in the p53 gene.

Animals↗
PubMed1995

Cell type-specific trans-activation by the B-myb gene product: requirement of the putative cofactor binding to the C-terminal conserved domain.

The myb gene family has three members, c-myb, A-myb and B-myb. We have examined the trans-activating capacity of the B-myb gene product (B-Myb) in various types of cells. B-Myb functions as a transcriptional activator in CV-1 and HeLa cells, but not in NIH3T3 cells, indicating that B-Myb is a cell type-specific transcriptional activator. Deletion analyses of B-Myb have demonstrated that the region conserved between three members of the myb gene family (CR for conserved region) is necessary for trans-activation by B-Myb. An in vivo competition assay suggests that regulatory factor(s) that binds to the CR of B-Myb is required for transactivation. Analyses using an affinity resin show that multiple proteins bind to the CR of B-Myb and that the CR-binding proteins in CV-1 and HeLa cells are different from those in NIH3T3 cells. These results suggest that the CR-binding cofactor(s) is critical for the cell type-specific trans-activation by B-Myb.

3T3 Cells↗
PubMed1995

Emergence of karyotypically unrelated clone in remission of de novo acute myeloblastic leukaemias.

Serial cytogenetic analysis revealed karyotypically unrelated clones in four patients with acute myeloblastic leukaemia (AML) in remission. At diagnosis, three patients had t(8;21)(q22;q22) and one had an inv(16)(p13q22). After 18-22 months in remission, different clones emerged in each patient with myelodysplastic features of the bone marrow cells. The emergence of clones with abnormalities of chromosome 7 in remission seems to be an unfavourable factor for prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Changes in circulatory status and transport function of the liver induced by reactive oxygen species.

To elucidate the pathogenesis of microcirculatory disturbance of the liver after ischemia and reperfusion, the effect of reactive oxygen species on hepatic circulatory status and transport function for a cholephilic compound was studied in an isolated perfused rat liver. Perfusion of the liver with a medium containing hypoxanthine and xanthine oxidase significantly increased the portal pressure, with concomitant decrease in intrahepatic vascular volume and hepatic uptake of bromosulfophthalein (BSP). Similar changes were also elicited by infusion of serotonin, which induces contraction of sinusoidal endothelial cells. Either superoxide dismutase or catalase added in the perfusion medium partially inhibited the oxidase-induced changes in portal pressure, vascular volume of hepatic sinusoid, and BSP transport. In the presence of superoxide dismutase, either catalase or erythrocytes inhibited the oxidase-induced changes completely. These results indicated that superoxide anion and hydrogen peroxide might induce contraction of hepatic resistance vessels, capacitance vessels, and/or sinusoidal endothelial cells and that this contraction decreased the vascular bed in the liver and the time for interaction of circulation substrates with hepatocytes, thereby decreasing hepatic transport for cholephilic ligands such as BSP.

Animals↗
PubMed1994

The effect of perioperative portal venous injection of donor spleen cells on renal allograft survival in dogs.

Preoperative portal venous injection of donor lymphocytes has been shown to extend allograft survival in inbred animals. However, the effect of perioperative injection in a large animal model has not been carefully studied. We examined the effect of perioperative (day 0) donor spleen cell administration in a canine kidney transplant model using both a double-donor transplantation and a single-donor survival study. In the double-donor model, two kidneys from two separate donors were transplanted into a single recipient. Spleen cells obtained from only one of the donors were injected through the portal vein immediately after reperfusion of the allografts. Both allografted kidneys were resected 14 days after transplantation and studied. There was only a slight cellular infiltrate in the kidney derived from the donor from whom spleen cells had been obtained, whereas a much more extensive cellular infiltrate as well as edema and hemorrhage were present in the other kidney. In a survival study of single allografts, the injection of 2 x 10(9) spleen cells significantly prolonged the mean survival time (15.0 +/- 3.4 days) compared with untreated recipients (6.6 +/- 2.2 days). Addition of cyclosporine did not significantly prolong survival in the spleen cell inoculated animals. These findings suggest that perioperative protal venous injection of donor cells may be a specific immunosuppressive method useful in clinical organ transplantation.

Animals↗
PubMed1994

Ellagic acid/phospholipid-induced coagulation and dextran sulfate-induced fibrinolytic activities in beta 2-glycoprotein I-depleted plasma.

Beta 2-glycoprotein I (beta 2-GPI) binds negatively charged substances and inhibits intrinsic blood coagulation in the presence of ellagic acid-phospholipid suspension. Beta 2-GPI is thought to be an important protein in the reaction between negatively charged phospholipids and anti-phospholipid antibodies which appear in patients with lupus anticoagulant/antiphospholipid antibody syndrome. We prepared a monoclonal antibody against beta 2-GPI purified from human plasma and obtained beta 2-GPI-depleted plasma using a monoclonal antibody-coupled column. Either partial thromboplastin time or the activation of prekallikrein induced by diluted ellagic acid-phospholipid suspension in beta 2-GPI-depleted plasma was not different from that in control plasma. Beta 2-GPI inhibited the intrinsic blood coagulation only when added to control or beta 2-GPI-depleted plasma in excess (more than physiological concentrations). The intrinsic fibrinolysis in beta 2-GPI-depleted plasma induced by dextran sulfate was not impaired and, again, beta 2-GPI inhibited the intrinsic fibrinolysis only when added to control or beta 2-GPI-depleted plasma in excess. These results indicate that both in vitro Actin-induced intrinsic coagulation and dextran sulfate-induced fibrinolytic activities are significantly inhibited by more than physiological concentrations of beta 2-GPI.

Amino Acid Sequence↗
PubMed1994

Multiple nuclear localization signals of the B-myb gene product.

Nuclear entry of the B-myb gene product (B-Myb) is dependent on multiple nuclear localization signals (NLS's). Mutagenesis of the putative NLS's of B-Myb has identified two separate NLS's, NLS1 and NLS2. Each of the two NLS's is essential for efficient nuclear targeting. NLS2 contains two interdependent basic domains separated by 8 intervening spacer amino acids, and both basic domains are required for nuclear entry. Thus, NLS2 belongs to a class of bipartite NLS's. Like the NLS's in yeast transcription factor SW15, NLS2 contains a putative cdc2 kinase site. However, unlike the case of SW15, phosphorylation at this site did not affect the nuclear targeting of B-Myb.

Amino Acid Sequence↗
PubMed1994

Telomere reduction of specific chromosome translocation in acute myelocytic leukemia.

The length of telomere restriction fragments (TRF) was studied by Southern blotting in 42 patients with acute myelocytic leukemia (AML) including 15 patients with 8;21 translocation, 8 with 15;17 translocation and 19 with a normal karyotype. The TRF length of leukemic cells with a normal karyotype and with 8;21 or 15;17 translocation showed significant reduction compared to that of lymphocytes from normal individuals (P < 0.05). In addition, there was a statistically significant difference in TRF length between leukemic cells with a normal karyotype and 8;21 translocation (P < 0.05). Therefore, the significant difference of telomere reduction in 8;21 translocation may be an important factor in the leukemogenic process.

Adolescent↗
PubMed1994

Changes in receptor-mediated endocytosis in liver sinusoidal cells after partial hepatectomy in the rat.

Liver sinusoidal cells play an important role in host defense by clearing particulate matter and macromolecules from the circulation. In this study, receptor-mediated endocytosis in sinusoidal cells was examined in two-thirds hepatectomized rats using 125I-labeled formaldehyde-treated bovine serum albumin (fBSA) as an endocytable macromolecule. The liver-weight to body-weight ratio in hepatectomized rats returned to the control value 10 days after hepatectomy. The endocytotic index for fBSA in sinusoidal cells decreased significantly to 0.0210 +/- 0.0017 (controls, 0.0598 +/- 0.0019) on the first day, then returned to the control level at 5 days (0.0554 +/- 0.0030). The changes in hepatic uptake for fBSA showed a similar time course of the endocytotic index. A transient increase in the uptake of fBSA per unit weight of liver of 22-39% above control occurred 2 to 3 days after hepatectomy. In contrast to fBSA, the endocytotic index in hepatocytes evaluated with 125I-labeled asialofetuin reached the minimum level on the second day, and then recovered to the control level 10 days after hepatectomy. These results suggest that endocytosis of fBSA by sinusoidal cells decreases after hepatectomy and rapidly recovers to normal before the completion of liver regeneration, whereas endocytosis of asialofetuin by hepatocytes decreases following hepatic resection and returns to normal when regeneration is substantially complete.

Animals↗
PubMed1994

Effects of hochu-ekki-to, a Japanese kampo medicine, on cultured hamster epididymal cells.

In Japan, Hochu-ekki-to (TJ-41), a Japanese Kampo preparation is used extensively in the treatment of idiopathic male infertility. In order to elucidate the mechanism of how this drug affects spermatogenesis, we examined the effects of the sera from male mice to which TJ-41 was administered orally, on protein synthesis in cultured hamster epididymal cells. Golden hamster epididymal cells were cultured in RPMI1640 medium supplemented with FCS for 7 to 10 days. After the initial culture period, the medium was changed to RPMI1640 supplemented with 1 microCi/ml [3H]-leucine and 10% serum from male ICR mice to which TJ-41 was orally administered for 7 days. The culture was then continued for 20 hours, and the uptake of [3H]-leucine into the cultured hamster epididymal cells was measured. The uptake of [3H]-leucine was significantly higher (p < 0.05) in cells cultured in media supplemented with sera from the TJ-41 treated mice than in cells cultured with control sera. Elements in the sera from control and TJ-41 treated mice were analyzed by high performance liquid chromatography (Waters HPLC, type 510; Milipore) with a mu-Bondapack C18 column. Several new peaks were detected in the sera from TJ-41 treated mice. These results and the clinical data suggest that TJ-41 may promote the synthesis of several proteins which might he related to the functional maturation of spermatozoa in the epididymis.

Administration, Oral↗
PubMed1994

Identification of illegitimate recombination hot spot of the retinoic acid receptor alpha gene involved in 15;17 chromosomal translocation of acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) has been characterized by 15;17 chromosomal translocation, which involves the retinoic acid receptor alpha (RARA) gene on chromosome 17 and the PML gene on chromosome 15. The breakpoints have been mapped to three cluster regions in the PML gene, and to RARA gene intron 2. We have examined the distribution of breakpoints within RARA gene intron 2. An extremely restricted region (ERR) of 50 bp within RARA gene intron 2 was identified as the cluster region of breakpoints by polymerase chain reaction and sequence analysis of DNA from APL patients. To study experimentally the mechanism involved in the translocation, ERR was tested in NIH3T3 cells by in vitro transfection-recombination assay, in which target sequences were placed either downstream of the SV40 promoter or upstream of the neo gene. Cells were conferred resistance to G418 only when the promoter was fused to the neo gene by recombination of two target sequences during transfection. The molecular junctions were analysed in five clones, and all of them were shown to be confined within a 20 bp region in a 148 bp DNA fragment containing ERR. This suggests that ERR might be the illegitimate recombination hot spot in mammalian cells.

3T3 Cells↗
PubMed1993

Structure and expression of hedgehog, a Drosophila segment-polarity gene required for cell-cell communication.

The complete nucleotide sequence of the coding region of hedgehog (hh), a segment-polarity gene in Drosophila melanogaster, was determined. The gene was found to include three exons which would encode a 421- (or 471-) amino acid (aa) polypeptide with a long hydrophobic stretch. The hh mRNA was about 2.3 kb long and expressed throughout development. The hh expression in an embryo occurred in stripes, while that in imaginal discs occurred in the posterior compartment. As a whole, the spatial expression pattern of hh mRNA was very similar to that of engrailed (en), a homeobox gene required for the formation of the anterior-posterior compartment boundary. Unlike en, no hh expression was observed in the central nervous system.

Animals↗
PubMed1993

Detection of PML/retinoic acid receptor a gene rearrangements by polymerase chain reaction using genomic DNA in patients with acute promyelocytic leukemia.

Breakpoints of the 15;17 translocation in patients with acute promyelocytic leukemia (APL) have been identified within PML and retinoic acid receptor a (RARA) genes in chromosomes 15 and 17, respectively. A wide heterogeneity was observed in the breakpoints on the PML and RARA genes. Therefore, amplification of the breakpoints region by polymerase chain reaction (PCR) with genomic DNA has been considered to be difficult. In the present study, a method was developed to detect the 15;17 translocation with genomic DNA. Of 13 patients with APL, four were detected to have the rearrangement of genomic DNA. At present, reverse transcriptase-polymerase chain reaction analysis is one of the methods available for diagnosis and detection of the residual leukemic cells in APL. In this study, PCR analysis using genomic DNA of APL cells is proved to be useful for identifying the breakpoints of the PML and the RARA genes. Furthermore, this method is applicable to patients for whom RNA samples of the leukemic cells are not available.

Base Sequence↗
PubMed1993

Japanese B cell chronic lymphocytic leukaemia: a cytogenetic and molecular biological study.

Clinical, cytogenetic, and molecular genetic studies were performed to clarify the pathophysiology of Japanese B cell chronic lymphocytic leukaemia (B-CLL), since the incidence of B-CLL in Japan is significantly lower than in western countries. The clinical and laboratory features of 55 Japanese patients with B-CLL in this study did not differ from those of Americans or Europeans with B-CLL. In the chromosome analyses, suitable metaphases with good band quality were obtained from 48 patients (87.2%), of whom 22 patients (45.8%) showed clonal chromosome aberrations and 14 (29.2%) had non-clonal aberrations. Trisomy 12 and abnormalities of 14q and 13q were found in four (18.2%), two (9.1%) and six patients (27.2%), respectively. There were no particular chromosome abnormalities or specific breakpoints in Japanese B-CLL. However, complex karyotype was found in higher incidence than in western countries. In the Southern blot analyses, rearranged band patterns were observed in the major breakpoint region (mbr) of the bcl-2 gene in one case, in the 5'-breakpoint region (5'-bcl-2) in two, and bcl-3 in one. Of the two patients with 5'-bcl-2 rearrangements, one had a normal karyotype and the other had t(2;18)(p12;q21). The incidence of rearrangements of the bcl-1, bcl-2 and bcl-3 genes in Japanese B-CLL was similar to that in western countries. These findings suggest that the biological characteristics of B-CLL in Japan are almost the same as those in western countries, although the incidence of B-CLL in Japan is quite different; this may be related to racial differences, which seem to be an important factor in the development of B-CLL.

Adult↗