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Biomedical subjects

H Oguchi

Publications and source records attributed to H Oguchi.

At least 55 records · Page 3Linked to original sources
PubMed1996

The 3M precise microvascular anastomotic system for implanting PTFE microvenous prostheses into the rat femoral vein.

Successful implantations of PTFE microvenous prostheses with 3M precise anastomosis systems were presented. Twelve PTFE prostheses (Gore-Tex;I.D.1.0 mm) were implanted into rat femoral veins by means of 3M precise technique to evaluated the patency rate. In the control group, PTFE prostheses (n = 12) were implanted by means of end-to-end technique. In the experimental group, patency of the PTFE prostheses was evaluated at 3 (n = 6) and 6 (n = 6) weeks after implantation by means of macroscopic inspection and scanning electron microscopy. All prostheses except one were patent at the time of removal (patency rate 91.7 percent). All the microvenous prostheses were completely covered by an endothelial layer at 3 and 6 weeks after implantation, and no stenosis was observed at the anastomotic sites. In the control group, all prostheses except one were found to be occluded 3 weeks after implantation. These results demonstrate the value of the 3M precise technique when implanting PTFE microvenous prostheses.

Anastomosis, Surgical↗
PubMed1996

A new HLA-DQB1*0306 allele sharing motifs from DQB1*03032 and DQB1*04 sequences.

We have discovered a new HLA-DQB1 allele in a Japanese family, MAT. In the family the new allele segregates in three generations and demonstrates the positive association with DRB1*0901. We observed a novel RFLP pattern in the course of examining the modified PCR-RFLP method for HLA-DQB1 genotyping. The PCR-SSOP analysis also showed a new hybridized pattern. Sequence analysis of the allele indicates that it was generated by a gene conversion-like event between the HLADQB1*03032 and one of DQB1*04 contemporary alleles. This new allelic product did not react with all of allosera and monoclonal antibodies against DQ1, DQ2, DQ3, DQ4 and DQ7. The HLA molecule encoded by the allele is not defined by serology. This new allele was officially recognized and named DQB1*0306 by the WHO Nomenclature Committee in November 1995.

Alleles↗
PubMed1996

Defective organification of iodide causing congenital goitrous hypothyroidism.

A 26-yr-old Japanese woman with congenital goitrous hypo-thyroidism and sensorineural deafness underwent a thyroidectomy. Examination of the thyroid gland revealed characteristic features of multinodular goiter. The T3 and T4 content in thyroglobulin (Tg) were 0.03 and 0.02 mol/mol Tg, respectively. Iodide incorporation into Tg, using slices of the thyroid tissue, revealed that iodide organification of thyroid tissue from our patient was markedly lower than that of normal controls. Then, guaiacol and iodide oxidation activities of thyroid peroxidase (TPO) in our patient's thyroid tissue were lower than those of normal controls (guaiacol assay: 1.92 vs. 30.0 +/- 5.7 mGU/mg protein; iodide assay: 1.1 vs. 6.6 +/- 2.8 mIU/mg protein). Lineweaver-Burk plot analysis of the oxidation rates of guaiacol and iodide indicated that this patient's TPO had a defect in the binding of guaiacol and iodide, but the coupling activity of the patient's TPO was not decreased compared with those of two normal thyroids. In this case and in control subjects, Nothern gel analysis of TPO messenger RNA from unstimulated and TSH-stimulated thyroid cells revealed a 3.2 kilobase species in the former and four distinct messenger RNA species of 4.0, 3.2, 2.1, and 1.7 kilobases in the latter. Western blot analysis of TPOs obtained from this patient and from control subjects identified the same 107 kDa protein, using antimicrosomal antibody-positive serum. We analyzed the coding sequence in the patient's TPO gene by using polymerase chain reaction technique. A single point mutation of G-->C at 1265 base pair was detected only in the TPO gene, but this point mutation does not alter the amino acid residue. It is possible that posttranslational modification such as abnormal glycosylation may occur in the TPO molecules. Furthermore, it is possible that there are differences in the tertiary structures of the TPO molecules between our patient and normal subjects. The above abnormalities of TPO molecules may play an important role in our patient's dyshormonogenesis.

Adult↗
PubMed1996

Gallium alloy restorations in primary teeth: a 12-month study.

The authors placed 60 Class I and Class V restorations in the primary molars of children aged 4 to 10 years using a gallium alloy. Within one year after placement, the surfaces of all the restorations had deteriorated significantly due to corrosion, and the authors found remarkable amounts of corrosion products on restorations retrieved after tooth extraction or loss. The marginal integrity of many of the Class I restorations deteriorated slightly during the study; the Class V restorations showed no marginal breakdown. No other problems were detected after one year. These data indicate that the gallium alloy tested had insufficient resistance to corrosion to serve as a permanent restorative material. However, the authors suggest consideration of this alloy for use in primary teeth to reduce the exposure of children and dental professionals to mercury-containing amalgam.

Alloys↗
PubMed1995

The complete nucleotide sequence of the mouse thyroid-specific enhancer-binding protein (T/EBP) gene: extensive identity of the deduced amino acid sequence with the human protein.

A mouse thyroid-specific enhancer-binding protein (T/EBP) gene and its flanking regions have been cloned and completely sequenced. The gene consists of 2 exons and exhibits high similarity (83-97%) to the rat sequence throughout the coding region and including an intron and up to 1.3 kbp upstream to the ATG initiation codon. A cDNA clone encoding human T/EBP has been also isolated and sequenced. Comparison of the deduced amino acid sequence of T/EBP revealed an extensive identity of 98% between mouse and the human protein.

Amino Acid Sequence↗
PubMed1995

Long-term histological evaluation of hydroxyapatite ceramics in humans.

We have investigated the interface between bone and hydroxyapatite (HA) chronically implanted in man. By light microscopy, HA appeared to bind directly to bone without intervening fibrous tissue. By transmission electron microscopy, two patterns were noted: (1) HA either bound directly to bone; or (2) electron-dense material intervened between HA and bone. The orientation of bone collagen fibres likewise showed two patterns: (1) collagen fibres were oriented parallel to the HA; or (2) the fibres were aligned perpendicularly. We have observed similar binding properties of HA to the jaw bone of humans in vivo and in vitro.

Adult↗
PubMed1995

[Multiple endocrine neoplasia type I].

Multiple endocrine neoplasia type 1 (MEN1) is characterized by the combined occurrence of primary hyperparathyroidism, pancreatic endocrine tumors, and neoplasms of the anterior pituitary gland. The disease is inherited as an autosomal dominant disorder with a high penetrance. Although many investigators have localized the causative genes to chromosome 11q3 by linkage analysis, the MEN1 gene remains unidentified. The use of molecular genetic markers in family linkage studies, however, have made it possible to identify gene carriers. Repetitive screening combined with the assignment of gene-carrier status will provide possibilities for therapeutic or prophylactic intervention earlier in the development of each of the manifestations of this syndrome, such as gastrointestinal bleeding secondary to ulcers or malignant transformation.

DNA↗
PubMed1994

In situ localization of transforming growth factor-beta 1 mRNA in the rat kidney with Masugi nephritis.

Masugi nephritis was induced in rats by the administration of nephrotoxic duck serum and, in their kidneys, the distributions of transforming growth factor-beta 1 (TGF-beta 1) mRNA, TGF-beta 1, and macrophage antigenic marker were investigated. Kidney specimens were obtained at 3, 7, and 14 days after the injection. By in situ hybridization, TGF-beta 1 mRNA was found to be localized in the cells of mesangial region from the early stage of nephritis. By the immunohistochemical stainings, TGF-beta 1 was found to be localized in the cells of distal convoluted tubulus throughout the experiments and the macrophage antigenic marker was found to be localized in the occasional cells which were different from that contained TGF-beta 1 mRNA. Our data indicate that TGF-beta 1 mRNA is expressed by the resident glomerular cells and not by the migrating macrophages in rat kidney with Masugi nephritis.

Animals↗
PubMed1994

Radiation-induced hypoplasia of the teeth and mandible. A case report.

Hypoplasia of the mandible and teeth is reported in a 4-year-old boy who had cystic hygroma. At age 7 months he had been treated with 60Co-gamma-radiation (24 Gy to the head and neck, 45 Gy to the mediastinum) followed by surgery. Panoramic and periapical radiographs showed hypoplasia of the roots of the primary canines, molars, and permanent teeth and no evidence of tooth germs. The patient was followed up to age 13 years.

Bone Development↗
PubMed1994

Sensitisation of human ovarian carcinoma cells to cis-diamminedichloroplatinum (II) by amphotericin B in vitro and in vivo.

Human ovarian carcinoma cells (HRA) were sensitised to cis-diamminedichloroplatinum (II) (CDDP) 2.7-, 5.5- and 12.1-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4 and 10.8 microM, respectively. Moreover, intracellular accumulation of platinum after a 2-h exposure to CDDP was increased significantly with AMB treatment. We prepared HRA cell-inoculated nude mice as an experimental therapeutic model for human advanced ovarian carcinoma. Ascites was evident after 7 to 9 days of intra-peritoneal (i.p.) inoculation of HRA cells, and mice died due to intra-abdominal carcinomatosis after 11 to 14 days [mean survival time (MST): 12.4 +/- 1.1 days]. Treatment with AMB (2.0 mg/kg) alone 4 days after inoculation increased MST by only 1.4 days. Simultaneous treatment with CDDP (1.0 to 2.0 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CDDP alone. Maximal MST (30.1 days) was observed by treatment with 2.0 mg/kg CDDP plus 2.0 mg/kg AMB, whereas MST with 2.0 mg/kg CDDP alone was 16.4 days. A further drug accumulation study demonstrated that platinum accumulation in tumour tissues in nude mice treated with CDDP and AMB increased significantly compared to treatment with CDDP alone. These results indicate that intraperitoneal combination chemotherapy with CDDP and AMB is effective in an experimental animal model of advanced ovarian carcinoma.

Amphotericin B↗
PubMed1994

Comparative study of CA242 and CA19-9 for the diagnosis of pancreatic cancer.

A comparative study of a new tumour marker, CA242, and CA19-9 was conducted with special reference to their diagnostic usefulness in pancreatic cancer. CA242 showed sensitivity similar to that of CA19-9 for overall cases and early cases (stage I tumour) of pancreatic cancer. For other malignancies, the positive rates of CA242 were lower than those of CA19-9 except for colorectal cancer. An important characteristics of CA242 was that it was only slightly and infrequently elevated in the sera of patients with benign diseases such as chronic pancreatitis, chronic hepatitis and liver cirrhosis. This characteristic was more apparent in the patients with benign obstructive jaundice, indicating that the serum level of this marker was scarcely affected by cholestasis. Using cut-off levels corresponding to a 90% specificity, the clinical results obtained with CA242 in the diagnosis of pancreatic cancer were similar to those obtained with CA19-9, except that CA19-9 was falsely negative in some patients with early-stage pancreatic cancer. These findings suggest the usefulness of this marker for screening pancreatic cancer in patients on their first hospital visit. However, CA242 was found to be influenced by the Lewis blood group system. This unfavourable result is attributed to the C241 catcher antibody of this assay system, which has almost the same epitope specificity as the C50 and the NS19-9 monoclonal antibodies. In conclusion, CA242 is superior to CA19-9 in diagnosing pancreatic cancer by virtue of its higher specificity.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

Epitope analysis of SPan-1 and DUPAN-2 using synthesized glycoconjugates sialyllact-N-fucopentaose II and sialyllact-N-tetraose.

Epitope analysis of SPan-1 and DUPAN-2 was compared with that of CA19-9 using the synthesized glycoconjugate sialyllacto-N-fucopentaose II (SLF II, sialyl-Lewis(a)) and its precursor, sialyllact-N-tetraose (LSTa, sialyl-Lewis(c)), conjugated to human serum albumin. The CA19-9 and DUPAN-2 assay systems specifically recognized SLF II and LSTa, respectively. The SPan-1 assay system recognized both SLF II and LSTa, although the reactivity with the former was far stronger than that with the latter. These results were, in general, compatible with those obtained from assaying these markers in the sera of two pancreatic cancer patients with definite Lewis-negative phenotype and in the sera of 39 CA19-9-negative pancreatic cancer patients. In conclusion, DUPAN-2 is the precursor of CA19-9 and is accumulated in the sera of pancreatic cancer patients with Lewis-negative phenotype and SPan-1 has an advantage over CA19-9 in the diagnosis of patients with Lewis-negative phenotype, although both markers have almost the same sensitivity for this malignancy.

Antibodies, Monoclonal↗
PubMed1994

Potentiation of cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) by amphotericin B in BALB/c nude mice bearing human ovarian carcinoma cells.

Human ovarian carcinoma cells (HRA) were sensitized to cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) 1.2-, 2.1- and 3.4-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4, and 10.8 microM, respectively. Moreover, the intracellular accumulation of platinum after 2-h exposure to CBDCA was increased significantly by AMB treatment. For estimating the enhancing effect of AMB on CBDCA cytotoxicity in vivo, we prepared HRA cell-inoculated nude mice. Ascites was evident 7 to 9 days after intraperitoneal (i.p.) inoculation of HRA cells, and the mice died of intraabdominal carcinomatosis 11 to 14 days (mean survival time (MST): 12.0 +/- 1.0 days) after inoculation. Treatment with AMB (2.0 mg/kg) alone increased the MST by only 1.2 days. Simultaneous treatment with CBDCA (12 or 15 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CBDCA alone. Maximal MST (38.5 days) was obtained by treatment with 15 mg/kg CBDCA plus 2.0 mg/kg AMB, whereas the MST with 15 mg/kg CBDCA alone was 15.8 days. A drug accumulation study demonstrated that platinum accumulation in tumor tissues after i.p. treatment with CBDCA and AMB in tumor-bearing nude mice was increased significantly compared to treatment with CBDCA alone. These findings indicate that intraperitoneal combination chemotherapy with CBDCA and AMB is useful in nude mice with advanced ovarian carcinoma.

Amphotericin B↗
PubMed1993

Synthesis of multivalent beta-lactosyl clusters as potential tumor metastasis inhibitors.

A beta-lactosyl residue was linked to the amino groups of L-lysyl-L-lysine through spacer arms of three different lengths (C2, C4, and C9) to give trivalent beta-lactosyl clusters in order to increase the inhibitory activity of the beta-lactosyl group against tumor cell colonization. Thus, O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-2,3, 6-tri-O-acetyl-glucopyranosyl trichloroacetimidate was treated with methyl or benzyl hydroxyethanoate, methyl or benzyl 4-hydroxybutanoate, and methyl 9-hydroxynonanoate, respectively, in the presence of trimethylsilyl trifluoromethanesulfonate to give the corresponding beta-lactosides. These were coupled to L-lysyl-L-lysine, after conversion to the N-hydroxysuccinimide esters, to yield the corresponding trivalent beta-lactosyl-L-lysyl-L-lysine conjugates in good yields. The beta-lactosyl group with a C4 spacer arm was also coupled similarly to poly(L-lysine) (M(r) 3800) to form a polyvalent beta-lactosyl cluster. Coinjection of the trivalent (with C2 and C4 spacer arms) and polyvalent beta-lactosyl clusters with the highly metastatic B16 murine melanoma cells inhibited the formation of lung colonies in C57/BL mice, whereas the trivalent cluster with a C9 spacer arm displayed no activity.

Animals↗
PubMed1993

A newly synthesized bifunctional inhibitor, W-77, enhances adriamycin activity against human ovarian carcinoma cells.

A newly synthesized calmodulin antagonist, (S)-P-(2-aminoethyloxy)-N-[2-(4-benzyloxy-carbonylpiperazinyl++ +)-1-(P-methoxybenzyl)ethyl]-N-methylbenzenesulfonamide dihydrochloride (W-77), acts as a calcium-independent uncompetitive antagonist which binds to glutathione-S-transferase (GST). We purified GST from human placenta using drug affinity chromatography on a column of W-77 coupled with Sepharose 6B and demonstrated that W-77 bound to GST. A spectrophotometric assay also showed that W-77 inhibited GST activity. We prepared Adriamycin-resistant and -sensitive cells from human ovarian serous cystadenocarcinomas. Immunoblot analysis revealed that GST expression was increased in the Adriamycin-resistant cells. We also purified GST from Adriamycin-resistant cells and found that W-77 bound to the GST obtained from these ovarian carcinoma cells. Adriamycin resistance was partially overcome by the addition of W-77 (10 microM) to the cultured cells. In addition, we investigated the effect of W-77 on P-glycoprotein. Northern blot analysis revealed MDR1 gene expression in Adriamycin-resistant cells. Although W-77 was less potent in increasing the intracellular Adriamycin content than verapamil, it was more effective in overcoming Adriamycin resistance. These results suggest that W-77 enhances the antitumor activity of Adriamycin by inhibiting both GST and P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Clinical remission criteria for epithelial carcinoma of the ovary.

After primary cytoreductive surgery 188 patients with epithelial ovarian cancer were treated with combination chemotherapy between 1986 and 1989 in the Tokai Ovarian Tumor Study Group. Clinical remission criteria were set in this study and patients were examined to determine if they were in remission or not. Forty-seven cases (25%) had no remission and 85.9% of them died within 20 months after primary surgery. Fifty-seven cases (30.3%) had a remission and a subsequent recurrence. Eighty-four cases (44.7%) had no recurrence and all are currently alive. Independent remission factors by multivariate analysis were higher stage (P = 0.018), clear-cell carcinoma (P = 0.0048), larger maximum residual tumor (P = 0.0023), and PVB therapy (P = 0.026). Independent recurrence factors were higher stage (P = 0.0012), serous cystadenocarcinoma (P = 0.0001), clear-cell carcinoma (P = 0.00409), and PVB therapy (P = 0.0499). A significantly high remission rate and low recurrence rate was achieved using PVB therapy. This criteria has value for the treatment of epithelial ovarian carcinoma. The disease-free survival rate after clinical remission was the same as that after a negative second-look laparotomy, which implies that a second-look laparotomy may be unnecessary in the management of epithelial carcinoma of the ovary.

Adenocarcinoma↗