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Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 1,459 records · Page 81Linked to original sources
PubMed1990

Identification of the amino acid residues involved in an active site of Escherichia coli ribonuclease H by site-directed mutagenesis.

The amino acid residues essential for the catalytic activity of ribonuclease H (RNase H) from Escherichia coli (E. coli) were identified by site-directed mutagenesis. It has been proposed by computer analysis that E. coli RNase H has homologous amino acid sequence with the RNase H domains of various retroviral reverse transcriptases (RTs) (Johnson, M. S., McClure, M. A., Feng, D. F., Gray, J., and Doolittle, R. F. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 7648--7652). Of the eight highly conserved residues examined, Asp10, Glu48, and Asp70 were found to be crucial for RNase H activity. Determination of the kinetic parameters for the mutated enzymes using the chemically synthesized nonanucleotide duplex as a substrate demonstrated that these residues are involved in the catalytic site rather than the substrate-binding site. These residues are fully conserved in the amino acid sequences of not only retroviral RTs but also hepadnaviral, plant viral and retrotransposon RTs. This strongly suggests that they are also involved in the active site of these RTs and RT related enzymes.

Amino Acid Sequence↗
PubMed1990

Differential modulation of growth and phenotypic expression of chondrocytes in sparse and confluent cultures by growth factors in cartilage.

The growth-promoting actions of cartilage extracts (CE) on rabbit cultured chondrocytes were studied to assess the role of local acting growth factors in the generation and expansion of highly differentiated cells. In the present study, DNA synthesis and proteoglycan synthesis in the cultured chondrocytes were monitored by flow cytofluorometry and double-isotope autoradiography by using [3H]thymidine and [35S]sulfate. We report here that actions of the same set of growth factors extracted from cartilage evokes differential cellular responses depending upon cell density. Growth factors in the optimal dose of CE (2 micrograms/ml) or epidermal growth factor (EGF, 40 ng/ml) did not reveal such a cell density-dependent effect on cellular proliferation. However, growth factors in CE induced proteoglycan synthesis selectively in nonproliferating and expressing cells in confluent culture.

Animals↗
PubMed1990

Characterization of flat revertants isolated from cells transformed by Abelson murine leukemia virus (Ab-MuLV).

Transformed Fisher rat fibroblast cell lines by Abelson murine leukemia virus frequently revert to the normal phenotype in usual culture conditions. Molecular biological analysis of three revertant clones isolated from the transformants showed that their morphological reversions were due to inactivation of the v-abl oncogene at multiple steps including transcription, translation or v-abl protein kinase activity itself without any change in structural gene expression of helper virus. These findings suggest the existence of a specific mechanism(s) for elimination of the v-abl oncogene by segregation, mutation, or gene rearrangement in these cells.

Abelson murine leukemia virus↗
PubMed1990

Endoscopic esophageal mucosal resection using a transparent tube.

Generally, it is considered technically impossible to perform an extensive mucosal resection of the esophagus using endoscopy. We have developed a new method of endoscopic esophageal mucosal resection using a transparent tube (EMRT). With this technique, any amount and any part of the esophageal mucosa can be safely and easily resected. After an experimental study, EMRT was performed in 11 patients and there were no major complications. Near-total circumferential resection of the mucosa was possible, and the surface of the esophageal muscle layer (non-bleeding resection layer) was left intact. We performed this technique on a patient with a mucosal cancer of the esophagus, and succeeded in resecting the lesion during a short course of treatment. We conclude that EMRT is of value in the endoscopic treatment of early-stage esophageal cancer.

Adult↗
PubMed1990

Esophageal varices evaluated by endoscopic ultrasonography: observation of collateral circulation during non-shunting operations.

To clarify the inflow and outflow vessels of esophagogastric varices, we investigated the collateral circulation using endoscopic ultrasonography (EUS; Olympus GF-UM2, 7.5 MHz, radial type) during non-shunting operations in 16 cases of portal hypertension. The main inflow vessels were the left gastric veins and the short gastric veins. The paraesophageal vessels coalescent with esophageal varices were distributed up to 7 cm from the esophagogastric junction. It was possible to devascularize these inflow vessels from the transabdominal approach, and it was also easy to evaluate the complete devascularization by the intraoperative EUS. The main outflow vein seemed to be the azygos arch from the investigation of cross-sectional areas of the azygos system. EUS is very useful in evaluating portal hypertension and in determining the indications and the efficacy of the treatment.

Adult↗
PubMed1990

Endoscopic injection sclerotherapy using a transparent overtube with intraluminal negative pressure (np-EIS) for esophageal varices.

Endoscopic injection sclerotherapy (EIS) using the transparent overtube (OT) method can be conducted safely and easily not only in elective esophageal varices but also in emergency cases because of the ability to obtain a good field of view and fixation of the varix. However, application of the OT method is limited because intravariceal injection into small varices through the slit of the OT is impossible. We devised a technique to apply the OT method to small varices by utilizing negative pressure in the OT (np-OT method). By using negative pressure, EIS with a transparent overtube is now suitable for all grades of esophageal varices, and the accuracy of puncture in EIS has been improved. Injection of the target area was successful in all cases. The rate of intravariceal injection has also been improved (47% in low-grade varices) because injection of all sites was possible. We call EIS by the np-OT method "np-EIS".

Esophageal and Gastric Varices↗
PubMed1990

Species identification of blood and bloodstains by high-performance liquid chromatography.

A reverse-phase high-performance liquid chromatographic method for species identification of blood and bloodstains is described. The method employs a 300 A pore SynChropak RP-4 column and ternary solvents (acetonitrile-trifluoroacetic acid-water) and can not only identify a species by its characteristic chromatogram, but also simultaneously demonstrates that it is of blood origin by the existence of the heme peak. Deformations in chromatographic profiles obtained with older bloodstains were observed, but the retention times of heme and the major peaks showed only minor changes. The species could be identified from bloodstains at least 3 months old and the present method has the advantage of simplicity, speed and sensitivity in the practice of forensic science.

Adult↗
PubMed1990

The effect of recombinant interleukin 2 in combination with mitomycin C on advanced cancer.

We recently discovered that the ability of cancer patients to generate lymphokine-activated killer (LAK) cells became remarkably augmented after mitomycin C (MMC) administration. Based on our clinical findings, we designed a treatment regimen comprised of MMC 12 mg/m2 given intravenously on day 1 and recombinant interleukin 2 (rIL 2) 700 U/m2 given intravenously every 12 hr from day 4 through day 8, when the generation of LAK cells had been shown to be markedly increased. Ten patients with various advanced carcinomas for which standard therapy had failed or no standard therapy was available, were treated with this regimen. Of these ten, three had a partial response and three others had a minor response. Fevers were common and anemia occurred in four patients, but nevertheless, severe toxicity was not encountered. These results indicated that rIL 2 in combination with MMC might be effective against advanced carcinoma without causing severe toxicity when these drugs are used in an appropriate combination.

Aged↗
PubMed1990

A tuberculous pseudoaneurysm of the thoracic aorta presenting as massive hemoptysis--a case of successful surgical treatment.

Tuberculous aneurysms of the aorta need early diagnosis and prompt surgical intervention because if untreated, they lead to severe consequences. We report herein, a case of a 63 year old woman who underwent successful resection of a tuberculous pseudoaneurysm which had ruptured into the left upper lobe of the lung after a punch biopsy, performed under bronchoscopy, had caused severe bleeding. Subsequent CT and MRI examinations suggested a fistula between the mass and the aorta and proved useful in establishing the diagnosis of a pseudoaneurysm. We wish to emphasize the need for bronchoscopy to be done carefully because of the risk of inducing massive hemoptysis.

Aorta, Thoracic↗
PubMed1990

Resection of the superior vena cava for primary lung cancer: 5 years' survival.

We describe a patient with squamous cell carcinoma of the right lung that required a resection of the superior vena cava combined with a tracheal sleeve pneumonectomy. The superior vena cava was totally replaced with a polytetrafluoroethylene graft with 115 minutes cross-clamping of the superior vena cava. The patient remains healthy and the polytetrafluoroethylene graft remains patent 5 years 4 months after operation.

Blood Vessel Prosthesis↗
PubMed1990

Proteolytic elimination of decay-accelerating factor (DAF): lytic abnormality coincides with removal of DAF in papain-treated human erythrocytes.

Erythrocytes (E) from patients with paroxysmal nocturnal hemoglobinuria (PNH) lack decay-accelerating factor (DAF) and this partly causes increasing susceptibility of the E to complement. Several reagents have been used to convert normal E to the complement-sensitive (PNH-like) cells. The relationship between DAF amounts and complement susceptibility of these PNH-like cels has been examined. Of the reported reagents for preparation of PNH-like cells, 2-amino-ethylisothiouronium bromide (AET), papain, and periodate efficiently converted normal E to the complement-sensitive cells, but only papain reduced the quantity of DAF on the cells. Further, of the proteases we tested only papain cleaved DAF to liberate its major fragment from the cells. The papain-treated cells lysed in a similar fashion to PNH cells as the serum concentration increased. The major papain-digested product of DAF had Mr, 55,000, lacked hydrophobicity, and retained the ability to inhibit the C3 convertases. These findings suggest that papain allows liberation from cells of functional domains as well as most of the antigenic epitopes of DAF to generate a PNH-like cell.

Blood Proteins↗
PubMed1990

A study on the vital reaction in wounded skin: simultaneous determination of histamine and polyamines in injured rat skin by high-performance liquid chromatography.

This paper describes a modified method of simultaneous quantitative determination of histamine and polyamines (putrescine, cadaverine, spermidine and spermine) in incised skin wounds of rats using high-performance liquid chromatography (HPLC) with a strong-cation exchange column, shim-pack ISC-05/S0504P, employing a linear gradient of 0.7-2.5 M sodium chloride. There was scarcely any change in the histamine content of the vital wounds throughout the one week experimental period, although content decreased slightly in 1-h-old wounds. On the other hand, concentrations of putrescine and spermidine increased suddenly 12 h after wounding, and spermine content increased slightly in 4-day-old wounds. There was no post-mortem change in the histamine, spermidine and spermine contents of vital wounds allowed to stand at 25 degrees C up to 24 h after death. Based on these results, this HPLC method may be useful for the determination of wound age during the period of healing.

Animals↗
PubMed1990

Effects of azelastine on vagal neuroeffector transmission in canine and human airway smooth muscle.

Azelastine is a newly developed antiallergic drug that is reported to antagonize histamine and leukotrienes in addition to its inhibitory action on release of chemical mediators. In the present study, the effects of azelastine on neuroeffector transmission in the airway smooth muscles with double sucrose gap and isometric tension-recording methods were evaluated. Azelastine (10(-8) to 10(-6) mol/L) markedly decreased the contractile response of human bronchial and dog tracheal muscle strips to electrical field stimulation (10 pulses at 20 V, 20 Hz, 800 microseconds) in a dose-dependent manner. In parallel with actions on twitch contractions, azelastine suppressed the amplitude of excitatory junction potentials of dog trachea without changing the resting membrane potential and input resistance of smooth muscle cells. However, azelastine did not alter acetylcholine sensitivity of the smooth muscle cells. These results indicate that azelastine possesses an inhibitory action on the release of acetylcholine by vagal nerve terminals. This inhibitory effect of azelastine may contribute to the treatment of asthma in addition to its antiallergic actions.

Acetylcholine↗
PubMed1990

Surveying cis-acting sequences of pre-mRNA by adding antisense 2'-O-methyl oligoribonucleotides to a splicing reaction.

We chemically synthesized antisense 12 mer 2'-O-methylribonucleotides and surveyed a scanning (signal-tracking) process as well as sequences within a beta-globin transcript acting in the splicing reaction in vitro. The pre-mRNA transcript contained the sequences of the first exon, first intron, and a major part of the second exon of the human beta-globin gene. We found that the antisense 2'-O-methylribonucleotides could anneal effectively to the target site in the pre-mRNA during the splicing reaction. A 2'-O-methylribonucleotide complementary to the donor (5') splice site completely inhibited authentic splicing and activated an upstream cryptic donor site. A 2'-O-methylribonucleotide complementary to the branch site inhibited normal branch formation and greatly reduced subsequent generation of the spliced product. Six other 2'-O-methylribonucleotides complementary to loci in the exons or the intronic region between the donor and branch sites had no significant effect on the splicing reaction. These observations suggest that an extensive scanning of the present pre-mRNA across the six regions tested is not essential for the splicing reaction. We propose that a short antisense 2'-O-methylribonucleotide provides a practical and convenient method to examine cis-acting sequences of RNA. The advantages of this method in comparison with site-directed mutagenesis or deletion are discussed.

Base Sequence↗
PubMed1990

Enhancement of cytotoxicity of active macrophages by mycoplasma: role of mycoplasma-associated induction of tumor necrosis factor-alpha (TNF-alpha) in macrophages.

Tumor necrosis factor-alpha (TNF-alpha)-inducing activity of several mycoplasmas including Mycoplasma pneumoniae, a causative agent in human respiratory infectious diseases, was investigated. Purified peritoneal macrophages from BALB/c mice markedly enhanced their cytotoxic activity to Meth A cells, when cultured with either viable or non-viable mycoplasmas. The supernatants of the macrophage culture with mycoplasmas, M. pneumoniae and Acholeplasma laidlawii, showed the potent cytotoxic activity to TNF-alpha-sensitive L cells but not to TNF-alpha-insensitive L cells. Addition of anti-TNF-alpha antiserum inhibited completely the cytotoxic activity of these supernatants, indicating that a major part of the cytotoxic activity might be due to TNF-alpha. Various other mycoplasmas, either glucose- or arginine-utilizing species, as far as tested showed also the potent activity to produce TNF-alpha. These results strongly suggest the possibility that mycoplasmas possess the activity of TNF-alpha induction which might be responsible for a part of enhancement of cytotoxic activity of macrophages and resistance to infection with mycoplasmas in vivo.

Animals↗
PubMed1990

A novel monoclonal antibody against squamous cell carcinoma.

The monoclonal antibody, INS-2, was raised against rat fibroblasts transformed by open reading frames E6 and E7 of human papillomavirus (HPV) DNA. In immunoperoxidase testing of frozen sections, the INS-2 antibody was reactive with all squamous cell carcinomas of the uterine cervix and esophagus tested. In contrast, no antibody binding was detected with adenocarcinomas of various origins. Similarly, normal tissues, lymphoid cells and erythrocytes from multiple donors were negative, except that binding localized at basal cells in normal squamous epithelium was observed. Interestingly, strong staining was observed in dysplastic cells of cervical intraepithelial neoplasia and at the growing edge of squamous cell carcinomas. The antigen for the INS-2 antibody is a non-sialyl glycoprotein with Mw. 40,000 and appears to be a squamous cell-specific cell differentiation marker, although it is not related to HPV-DNA-derived protein.

Animals↗