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Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Evaluation of anastomosis between intrahepatic or extrahepatic vessels by intra-arterial digital subtraction angiography using carbon dioxide].

Carbon dioxide (CO2) intraarterial subtraction angiography (IADSA) was performed in 31 patients with various hepatobiliary diseases. The injection sites of CO2 were proper hepatic artery (10/31; group A), segmental hepatic artery (18/31; group B), and peripheral inferior phrenic artery (3/31; group C), respectively. In group A, only the third order branches of the portal venous system were visualized anterogradely in 8 of 10 patients. In group B, the microcatheter was placed coaxially through a 5 French guiding catheter at the main arterial supply of the tumor in 7 patients and at the peripheral segmental branch of the hepatic artery in 11 patients. The portal venous system was visualized retrogradely in all of the patients regardless of the injection site. The injected CO2 may flow back into the portal vein through the anastomosis known as the peribiliary or periportal plexus. In group C, not only the portal vein but also the pulmonary artery or pericardial vein were visualized by this method. CO2-IADSA was useful to image the minute communications between the various vessels, which have been not hitherto visualized by iodinated contrast medium.

Adult↗
PubMed1995

Long-term outcome of operative treatment of focal atrial tachycardia.

BACKGROUND: This study examined the long-term clinical outcome of patients with focal atrial tachycardia who were treated surgically. Focal atrial tachycardia is a relatively rare arrhythmia that is often difficult to control with conventional medical therapy. Therapeutic modalities are not well defined because of the scarcity of long-term data of treated patients, including pathologic findings. STUDY DESIGN: Nine patients, six men and three women, ranging in age from 16 to 50 years (mean of 34 +/- 14 years), underwent operative treatment for focal atrial tachycardia. The average rate of tachycardia was 167 +/- 22 beats per minute. All patients were treated with antiarrhythmic drugs (mean 2.9 drugs per patient). Concomitant operative procedures were performed upon four patients, including division of the accessory atrioventricular pathway for the Wolff-Parkinson-White syndrome in two patients, plication of the right atrium for idiopathic right atrial dilatation in one patient, and a closure of the atrial septal defect in one patient. Focal ablation was performed in all instances. RESULTS: There was no early or late death nor postoperative complications. Atrial tachycardia disappeared and there were no episodes of recurrent tachycardia postoperatively during the mean follow-up period of 67 +/- 38 months. Histopathologic findings from four patients revealed a sinus node-like structure, diffuse chronic epimyocarditis, focal myocarditis, and fascicular disarray lesions. CONCLUSIONS: Excellent long-term result were obtained in patients with focal atrial tachycardia who were treated operatively. Early operative intervention is preferable before the occurrence of impaired ventricular function. From the histopathologic findings, operative therapy should be selected in patients with diffuse atrial lesions.

Adolescent↗
PubMed1995

[Endoscopic mucosal resection of esophageal cancer].

Limited surgery, esophagectomy without thoracotomy or endoscopic mucosal resection (EMR), is indicated for mucosal cancer of the esophagus without lymph node metastasis. Mucosal cancer less than 2 cm in size or less than a third of the circumference of the esophagus, is suitable for EMR. However, mucosal cancer invasive to the muscularis mucosa is excluded. As for postoperative complications, a small fissure, two cases of stenosis and 3 cases of oozing bleeding, were experienced. Conservative treatment was performed for all patients except one. The 5-year survival rate of EMR was 95%-100% in several institutions in Japan. Recurrence was observed in 3%-7%, however, it was cured by means of local treatment of esophageal cancer.

Esophageal Neoplasms↗
PubMed1995

[Fibroma of the bladder associated with a large diverticulum: a case report].

A 57-year-old woman was admitted with a chief complaint of difficult urination on June 7, 1993. A filling defect and a large diverticulum were revealed on the cystogram. Cystoscopy showed a tumor, obstructing the internal urethral orifice at the bladder neck and a diverticulum at the right posterior wall of the bladder. Under the preoperative diagnosis of a benign bladder tumor with a diverticulum, resection of the tumor and transvesical diverticulectomy were performed by a suprapubic approach. The resected tumor was smooth-surfaced, elastic soft and was measured 2.0 by 1.5 by 1.0 cm in size. Histologically, the tumor was diagnosed as a benign fibroma of the urinary bladder. The postoperative course was uneventful. Non-epithelial benign bladder tumors are rare. To our knowledge, this is the 18th case of bladder fibroma in the Japanese literature. The characteristics of bladder fibroma are briefly described.

Diverticulum↗
PubMed1994

Molecular cloning and site-directed mutagenesis of glutathione S-transferase from Escherichia coli. The conserved tyrosyl residue near the N terminus is not essential for catalysis.

Glutathione S-transferase (GST) was purified from Escherichia coli K-12, and its N-terminal sequence was determined to be MKLFYKPGAXSLAS. The gene encoding this sequence was cloned and mapped at 1731-1732 kilobases on the E. coli gene map. It encoded a polypeptide of 201 amino acid residues with a calculated molecular weight of 22,860. The overexpressed product of the gene was confirmed to have GST activity toward 1-chloro-2,4-dinitrobenzene and ethacrynic acid and GSH-dependent peroxidase activity toward cumene hydroperoxide. The relative molecular mass of the gene product was determined to be 40,000 by gel chromatography and 25,000 by SDS-polyacrylamide gel electrophoresis, indicating a homodimeric structure. The deduced amino acid sequence was 54% identical with that of Proteus mirabilis GST. Although the homologies between the GSTs from E. coli and mammals were low, many of the residues assigned to be important for the enzymatic function or structure in mammalian cytosolic GSTs were found to be conserved in E. coli GST. Therefore, E. coli GST is considered to have diverged from the same ancestor with other cytosolic GSTs. A specific tyrosyl residue in the vicinity of the N terminus is conserved in all of the known cytosolic GSTs and has been shown to function as a catalytic residue in alpha, mu, and pi class GSTs from mammals. Although Tyr5 in E. coli GST appeared to be the counterpart of the catalytic residue, its replacement with phenylalanine did not significantly affect the enzymatic activity. Therefore, this apparently conserved tyrosyl residue is not essential for catalytic activity in E. coli GST.

Amino Acid Sequence↗
PubMed1994

Studies of the interactions between Escherichia coli ribonuclease HI and its substrate.

Ribonuclease H (RNase H) recognizes a DNA-RNA hybrid duplex and catalyzes the hydrolysis of the phosphodiester linkages in only the RNA strand. Previously, we developed a method to cleave RNA in a sequence-dependent manner using RNase H and a complementary oligonucleotide containing 2'-O-methylribonucleosides. Since cleavage is restricted to a single site by the modified complementary strand, this system allows kinetic analysis of the RNase H reaction. We describe an investigation of the interactions between RNase HI from Escherichia coli and its substrate, and between the substrate and a metal ion using synthetic oligonucleotide duplexes modified at the cleavage site in combination with the 2'-O-methylribonucleotides. Firstly, the base moiety was changed to interfere with enzyme binding in either the major or minor groove. When 2-N-methylguanine was incorporated into the cleavage site, the Km value for this substrate, containing a methyl group in the minor groove, was 20-fold larger than that for the unmodified substrate, whereas 5-phenyluracil, with a phenyl group residing in the major groove of the duplex, did not affect the affinity. Secondly, the phosphodiester linkage at the cleavage site was changed into a phosphorothioate with a defined configuration. Only the Rp isomer was cleaved at this site in the presence of Mg2+ or Cd2+. These results suggest that the enzyme, but not the metal ion, interacts with the phosphate residue at the cleavage site. Thirdly, the 2'-position of the nucleoside on the 5'-side of the scissile phosphodiester was modified. Alteration of the 2'-hydroxyl function into an amino, fluoro or methoxy group, or removal of this 2'-hydroxyl group, did not affect the affinity for the enzyme, but reduced the reaction rate. An outer sphere interaction of a metal ion with the 2'-hydroxyl group is suggested.

Base Sequence↗
PubMed1994

The cyclic AMP response element plays an essential role in the expression of the human prostaglandin-endoperoxide synthase 2 gene in differentiated U937 monocytic cells.

The promoter activity of 1432 bp upstream of the human prostaglandin-endoperoxide synthase 2 gene (PTGS2) was examined in differentiated U937 monocytic cells expressing prostaglandin-endoperoxide synthase 2 mRNA. Transient transfection experiments were performed using these cells and reporter vectors containing the upstream region of the gene with deletions or site-specific mutations and the luciferase gene. The deletion or destruction of the cyclic AMP response element (nucleotides -59 to -53) markedly reduced the promoter activity of this gene. Electrophoretic mobility shift assays showed that a nuclear protein(s) binding to the cyclic AMP response element was induced during monocytic differentiation of U937 cells. These results indicate that expression of the human prostaglandin-endoperoxide synthase 2 gene in differentiated U937 monocytic cells is regulated by the cyclic AMP response element.

Base Sequence↗
PubMed1994

Isolation and molecular cloning of prostacyclin synthase from bovine endothelial cells.

Prostacyclin synthase catalyzes the conversion of prostaglandin H2 to prostacyclin, which is a powerful vasodilator and the most potent natural occurring inhibitor of platelet aggregation. In the present study, we determined the amino acid sequence of bovine prostacyclin synthase by combined protein chemical and molecular cloning techniques. The enzyme was purified and characterized from bovine aorta microsomes, and the partial amino acid sequences were determined with the native enzyme and endoproteinase Lys-C-cleaved peptides. Using primers synthesized according to the amino acid sequences, cDNA coding for prostacyclin synthase was amplified by polymerase chain reaction with bovine endothelial cell poly(A)+ RNA and cloned into pBluescript II. Nucleotide sequence analyses of the cloned cDNA inserts revealed that cDNA for this enzyme contained a 1500-base pair open reading frame coding for a 500-amino acid polypeptide with a M(r) of 56,628. COS-7 cells transfected with an expression plasmid harboring this cDNA clone expressed prostacyclin synthase activity. The primary structure of the enzyme showed structural characteristics of cytochrome P450 and exhibited a 32% identity to that of human cholesterol 7 alpha-hydroxylase. However, the identity between the amino acid sequences of bovine prostacyclin synthase and human thromboxane synthase was only 16%, and no P450 showed an identity higher than 40%, suggesting that prostacyclin synthase represents a new family in the P450 superfamily. RNA blot analysis indicated that the mRNA for prostacyclin synthase from bovine endothelial cells showed a size of approximately 2.7 kilobases and that the mRNA level increased about 3-fold by treatment of tumor necrosis factor-alpha.

Amino Acid Sequence↗
PubMed1994

Induction of photoresponse by the hydrolysis of polyphosphoinositides in the Hermissenda type B photoreceptor.

Direct evidence that the photoresponse of the Hermissenda type B photoreceptor cell is triggered directly by the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) was obtained. Neomycin and spermine, which inhibit PIP2 breakdown, suppressed light response, while injection of inositol 1,4,5-trisphosphate (IP3), guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), guanosine 5'-(2-O-thio)diphosphate (GDP beta S), cAMP, cGMP did not alter the light-induced Na+ influx underlying the photoresponse. Suppression of the photoresponse was also observed with decrease of total amount of membraneous PIP2 induced by injection of the phosphoinositides (PI) turnover inhibitors, isobutylmethylxanthine (IBMX), LiCl and R 59022.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Regulatory mechanisms of cAMP-dependent and cell-specific expression of human steroidogenic cytochrome P450scc (CYP11A1) gene.

Cytochrome P450scc (CYP11A1) is the enzyme that catalyzes the side-chain cleavage reaction of cholesterol, the first and rate-limiting reaction in the biosynthesis of steroid hormones in the adrenal cortex. DNase-I-footprinting analysis using nuclear extracts from the bovine adrenal cortex and the 5' upstream regulatory region (nucleotides -1697 to -1523) of the CYP11A1 gene, which is mainly required for response to cAMP [Inoue, H., Watanabe, N., Higashi, Y. & Fujii-Kuriyama, Y. (1991) Eur. J. Biochem. 195, 563-569], revealed that some protein factors bound to that region. One of the sequences protected by the binding factors is a cAMP-responsive-element (CRE)-like sequence, which is known to be recognized by CRE-binding protein (CREB) or its related proteins, and another is a sequence designated Ad4 which is bound by a tissue-specific factor, Ad4-binding protein (Ad4BP). The region containing the two closely arranged DNA sequences showed a high level of cAMP responsive and cell-specific expression when it was fused to the basal promoters. Introduction of point mutations in these sequences demonstrated that the CREB/ATF factors and Ad4BP bound to the sequences showed synergistic enhancer effects on cAMP-responsive and cell-specific expression of the CYP11A1 gene.

Animals↗
PubMed1994

Sequence-specific cleavage of RNA by a hybrid ribonuclease H.

Site-specific cleavage of the 22-, 132- and 534-base RNAs by the DNA/protein hybrid RNase H were examined. The 22-base RNA was chemically synthesized, and 132- and 534-base RNAs were prepared by run-off transcription. The hybrid enzyme cleaves these RNAs, which contain a single target sequence, primarily at the unique phosphodiester bond within the target sequence. The hybrid enzyme performs multiple turnovers, and at a substrate/enzyme ratio of 10:1 the RNAs are almost completely cleaved by the hybrid enzyme at 37 degrees C within 1 h. We propose that hybrid RNase H molecules with various oligodeoxyribonucleotides function as RNA restriction enzymes and are useful for structural and functional studies of RNA.

Base Sequence↗
PubMed1994

Selective adhesion of platelets on a polyion complex composed of phospholipid polymers containing sulfonate groups and quarternary ammonium groups.

We investigated the effects of electrical charges on cell-polymer interactions of poly[2-methacryloyloxyethyl phosphorylcholine(MPC)-co-n-butyl methacrylate (BMA)] (PMB) having excellent blood compatibility, by copolymerizing anionic or cationic methacrylates with MPC and BMA. A polyion complex (PIC) composed of anionic and cationic MPC copolymers was also prepared. When the cell adhesion on these polymer surfaces from rabbit whole blood was evaluated, we observed a considerable reduction in cell adhesion on the MPC copolymers compared with that on poly(BMA), even when the MPC copolymer was electrically charged. On the other hand, many platelets selectively adhered to the PIC surface from whole blood, but the adherent platelets maintained a discoid shape. The amount of adenosine triphosphate (ATP) in platelets adherent on the PMB or the PIC from a platelet-rich plasma (PRP) was more than 75% of that in the original PRP, which indicated that the activity of these platelets remained high. However, in the platelets adherent to poly(BMA), only a small amount of ATP remained. Protein adsorption on the polymer surface from human plasma was investigated using a gold-colloid-labeled immunoassay against albumin gamma-globulin, and fibrinogen. Many of these proteins adsorbed on poly(BMA), whereas a small amount of protein was observed on the MPC copolymers that had an electrical charge. Albumin adsorption and suppression of gamma-globulin and fibrinogen adsorption were found on the PIC. Therefore, the introduction of electrical charges in the PMB did not have an adverse effect on cell adhesion and protein adsorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1994

Degradation of p53 only is not sufficient for the growth stimulatory effect of human papillomavirus 16 E6 oncoprotein in human embryonic fibroblasts.

Certain types of human papillomavirus (HPV), such as types 16 and 18, are thought to be responsible for the development of cervical carcinomas. The E6 and E7 genes of these viruses have transforming activities in various cultured cells and their mRNAs and proteins are expressed in almost all cervical carcinoma cells. Inactivation of the tumor suppressor p53 protein by the E6 gene is believed to be critical for transformation by these oncogenic HPVs. To determine whether degradation of the p53 protein is, in fact, sufficient for cellular transformation by the E6 gene, the E6 gene of HPV16 was introduced into human embryonic fibroblasts (HEF) using recombinant murine retrovirus and examined whether reduction of the p53 protein could substitute for the E6 function. It was found that HEF cells transfected with the E6 gene showed an increased saturation density and degraded the p53 protein. However, when expression of the p53 protein in normal HEF cells was suppressed by the antisense oligonucleotide of the p53 gene, growth stimulation was not observed. These results show that the E6 gene stimulates growth of HEF cells, but that this activity involves some other E6 gene-mediated functions than degradation of the p53 protein.

Base Sequence↗
PubMed1994

Incidence of latent infection of Epstein-Barr virus in lung cancers--an analysis of EBER1 expression in lung cancers by in situ hybridization.

To evaluate the presence of Epstein-Barr virus (EBV) in lung cancers of Japanese patients, 81 lung cancers were examined using a highly sensitive in situ hybridization (ISH) method, employing an antisense oligonucleotide probe for EBV-encoded small nuclear RNA-1 (EBER). EBER1 expression was demonstrated in one poorly differentiated squamous cell carcinoma associated with marked lymphoid stroma (PDSCC-LS), two well differentiated adenocarcinomas, and two moderately differentiated squamous cell carcinomas, but was not detectable in other lung cancers, including small cell carcinomas. Unlike lymphoepithelioma-like undifferentiated carcinoma (LELC) of the lung, the PDSCC-LS consisted of poorly differentiated cells with distinct cell borders and nuclei with a coarse chromatin pattern and some prominent nucleoli. Most of the cancer cells expressed intense EBER1 signals. Although small to moderate numbers of cells positive for EBER1 were present in two adenocarcinomas and two squamous cell carcinomas, EBER1 signals varied in intensity and number in these four cases. Although polymerase chain reaction (PCR) and Southern blot hybridization with a 32P-labelled probe internal to the primers were conducted to detect the EBV genome in 24 lung cancers, including five EBER1-positive cases, the genome was found to be positive in the five cases with EBER1-positive staining, including the PDSCC-LS, two adenocarcinomas and two squamous cell carcinomas, but not in the other cases. This study indicates that the morphological features of EBV-associated lung cancers are not restricted to the typical LELC type.

Adenocarcinoma↗