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Biomedical subjects

H Mizuno

Publications and source records attributed to H Mizuno.

At least 163 records · Page 9Linked to original sources
PubMed1995

[Clinical experience of the combined use of polyglycolide non-woven felt with fibrin glue to prevent postoperative pulmonary fistula].

Felt prepared from polyglycolide (PGA) polymer fibers was pasted with fibrin glue for prevention of postoperative pulmonary fistula, and its effects were evaluated. The subjects were 90 patients who underwent thoracotomy and were expected to develop air leakage between March 1990 and the end of 1993. The felt sheet was simply pasted in position in 67 patients, applied and fixed by suturing in 7, and sutured and pasted in 16. The duration of air leakage in the three groups were 4.6 +/- 4.1, 3.9 +/- 4.9, and 3.2 +/- 3.8 days, respectively. According to the surgical procedure employed, the duration of air leakage was 5.0 +/- 4.0 days in 41 patients who underwent pulmonary lobectomy, 5.0 +/- 4.3 days in 5 patients who underwent segmentectomym, 2.6 +/- 3.1 days in 26 cases who underwent partial pneumonectomy, and 4.9 +/- 4.0 days in the 14 cases who underwent bulla resection. In terms of disease, the leakage time was 4.6 +/- 4.2 days in patients with emphysema, 0.6 +/- 1.2 days in those with diffuse pulmonary fibrosis, 0.7 +/- 0.9 days in those with Infectious disease, 4.8 +/- 4.2 in those with lung cancer, 1.5 +/- 1.5 days in those with benign lung tumor, and 3.8 +/- 2.7 days in those with metastatic lung tumors. The procedure had no side-effect on liver or kidney function. No infection was observed even after decortication for empyema. The use of felt prevented excessive shrinking of the lung due to over-suturing. Therefore, intraoperative application of a PGA felt sheet was considered to be an effective method for prevention of pulmonary fistula.

Aged↗
PubMed1994

Poor response of cultured mast cells derived from mi/mi mutant mice to nerve growth factor.

Decreased numbers of mast cells and abnormalities in the phenotype of mast cells are observed in the skin of mi/mi mutant mice. Recently, the mi locus was identified to encode a novel member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors. Since nerve growth factor (NGF) has been reported to influence the proliferation and the phenotype of cultured mast cells (CMCs), we compared the effect of NGF between mi/mi and control normal (+/+) CMCs. Addition of NGF to the suboptimal dose of recombinant murine interleukin-3 (rmIL-3) increased the plating efficiency of +/+ CMCs, but not of mi/mi CMCs. Although +/+ CMCs were berberine sulfate-negative when cultured with rmIL-3 alone, +/+ CMCs became berberine sulfate-positive when cultured in the presence of both rmIL-3 and NGF, which suggests increased heparin content. In contrast, NGF did not influence the phenotype of mi/mi CMCs. +/+ CMCs significantly bound 125I-NGF, but mi/mi CMCs did not, which suggests a defect of NGF receptors in mi/mi CMCs. Both p75 and p140 molecules are known to be involved in the formation of NGF receptors. Although the expression of p140 messenger (m)RNA was comparable between +/+ and mi/mi CMCs, the expression of p75 mRNA was significantly lower in mi/mi CMCs than in +/+ CMCs. Taken together, the poor response of mi/mi CMCs to NGF appeared to be attributable to the impaired transcription of the p75 gene.

Animals↗
PubMed1994

Molecular cloning of a human transmembrane-type protein tyrosine phosphatase and its expression in gastrointestinal cancers.

To determine the expression of various protein-tyrosine phosphatases (PTPs) in human gastric cancers, cDNAs encoding conserved PTP domains were amplified by reverse transcriptase polymerase chain reaction from KATO-III cell mRNA and sequenced. Among 72 polymerase chain reaction clones, one of the cDNA sequences encoded a novel potential PTP (stomach cancer-associated PTP, SAP-1). The full length (3.9 kilobases) of the SAP-1 cDNA was further isolated from the KATO-III cell cDNA library and the WiDr cell cDNA library. The predicted amino acid sequence of the SAP-1 cDNA showed that mature SAP-1 consisted of 1093 amino acids and a transmembrane-type PTP, which possessed a single PTP-conserved domain in the cytoplasmic region. The extracellular region of SAP-1 consisted of eight fibronectin type III-like structure repeats and contained multiple N-glycosylation sites. These data suggest that SAP-1 is structurally similar to HPTP beta and that SAP-1 and HPTP beta represent a subfamily of transmembrane-type PTPs. SAP-1 was mainly expressed in brain and liver and at a lower level in heart and stomach as a 4.2-kilobase mRNA, but it was not detected in pancreas or colon. In contrast, among cancer cell lines tested, SAP-1 was highly expressed in pancreatic and colorectal cancer cells. The bacterially expressed SAP-1 fusion protein had tyrosine-specific phosphatase activity. Immunoblotting with anti-SAP-1 antibody showed that SAP-1 is a 200-kDa protein. In addition, transient transfection of SAP-1 cDNA to COS cells resulted in the predominant expression of a 200-kDa protein recognized by anti-SAP-1 antibody. SAP-1 is mapped to chromosome 19 region q13.4 and might be related to carcinoembryonic antigen mapped to 19q13.2.

Amino Acid Sequence↗
PubMed1994

Omentoplasty for postpneumonectomy bronchopleural fistulas.

Postpneumonectomy fistula is one of the most serious complications in general thoracic surgery and remains difficult to manage. From 1984 to 1991, we successfully used pedicled omentum for the treatment of postpneumonectomy bronchopleural fistulas (omentoplasty) in five patients, four of whom had thoracic empyema. For bronchopleural fistulas without early postoperative infection, single-stage closure was performed which was then covered with pedicled omentum. Omentoplasty was performed successfully in patients with thoracic empyema, after open or closed drainage. Open thoracotomy was useful when closed drainage was ineffective. Even after open thoracotomy, closure of the wound was achieved. All five patients could be discharged. Omentoplasty was useful in the therapy of postpneumonectomy bronchopleural fistula even in the presence of thoracic empyema.

Aged↗
PubMed1994

Synthesis of 1,5-anhydro-D-glucitol from glucose in rat hepatoma cells.

A pyranoid polyol, 1,5-anhydroglucitol (AG), generally occurs in the human body as a humoral component. The plasma AG concentration in healthy individuals is maintained at a constant level, but it is markedly decreased in diabetes mellitus. This is due to hyperglycemia-dependent abolishment of renal AG retention. Hence, the plasma AG concentration has been established as a clinical marker for duration of hyperglycemia and since 1991 it has been practically applied to diabetic care in Japan. However, the details of the metabolism of AG and its physiological significance generally remain to be studied. In this study, we confirmed AG synthesis in cultured cells of a rat hepatoma line, Reuber H-35, in which AG was found to be derived from glucose, with retention of all six carbon atoms in the pyranoid structure. The fraction of the total glucose consumed by the cells, which was converted to AG (conversion efficiency) was at most 5 x 10(-6). The conversion efficiency increased at higher glucose concentrations (mM orders) where the glucose consumption rate was saturated. Since the rate of the hexokinase reaction, one of the rate-limiting steps in glucose consumption, has been estimated to be saturated at microM orders of glucose concentration, this observation was interpreted as indicating that AG is synthesized through a pathway which does not share the hexokinase reaction with glucose utilization. The presence of precursors other than glucose was also indicated in the time-course study of AG synthesis. Further, the amount of AG synthesized daily in humans is significant in comparison with the amount obtained from the diet.

Animals↗
PubMed1994

Combined paraumbilical perforator skin flap and vascularized pubic bone graft.

A severely depressed deformity of the buccal region was repaired with an osteocutaneous flap based on the deep inferior epigastric vessels. This osteocutaneous flap has not been previously described in the literature. The superior pubic ramus, supplied by pubic branches from the deep inferior epigastric vessels, forms the bony portion of the combined flap. The cutaneous portion is also supplied by the deep inferior epigastric vessels and its thickness can be adjusted. This combination is useful when requiring both a thin flap and a flat bone.

Adult↗
PubMed1994

Effects of RS-2135, a novel class I antiarrhythmic agent, on sustained ventricular tachycardia after coronary embolization in conscious dogs.

To assess the ability of RS-2135, a novel class I antiarrhythmic agent to suppress ischemia-induced ventricular arrhythmias, we produced myocardial infarction (MI) by introducing a glass bead into the coronary artery of the dog (bead model). Ventricular arrhythmias after coronary embolization were as severe and long-lasting as those that occur after two-stage coronary artery ligation as described by Harris. RS-2135 (1.25 and 2.5 mg/kg intravenously, i.v.) suppressed sustained ventricular tachycardia (SVT) 24 h after coronary embolization in the bead model. The antiarrhythmic effects of i.v. administration of RS-2135 were more potent and more long-lasting than those of lidocaine (5 and 10 mg/kg i.v.), mexiletine (5 and 10 mg/kg i.v.), disopyramide (2.5 and 5 mg/kg i.v.), and flecainide (2.5 and 5 mg/kg i.v.). The antiarrhythmic effects of oral (p.o.) administration of RS-2135 were evaluated 48 h after coronary embolization. RS-2135 (10 mg/kg p.o.) was equipotent to flecainide (10 mg/kg p.o.) and twice as potent as disopyramide (20 mg/kg p.o.) and mexiletine (20 mg/kg p.o.). Onset of antiarrhythmic effects after p.o. RS-2135 was slower than that of other drugs. These data suggest that the bead model is as useful as the Harris model for evaluation of the antiarrhythmic potential of chemicals and that RS-2135, either i.v. or p.o., is effective against SVT after acute MI.

Administration, Oral↗
PubMed1994

Agents for the treatment of overactive detrusor. VI. Synthesis and pharmacological properties of acetamide derivatives bearing cyclic amines in N-substituents.

With the aim of improving of the efficacy and decreasing the side effects of oxybutynin (1), N-[(tetrahydro-3- or 4-pyridyl)methyl]-, N-(4-piperidyl)-, and N-(3- or 4-piperidylalkyl)-2-hydroxyacetamides (3a-n, 4a-g) and the related carboxamides (3o-r, 4h-k, 13', 17) were synthesized and evaluated for inhibitory activity against urinary bladder rhythmic contraction in rats and for mydriatic activity in rats. Some of these compounds were superior to oxybutynin in both inhibitory activity against bladder contraction and selectivity between inhibitory activity against bladder contraction and mydriatic activity. Among them, N-[(1,2,3,6-tetrahydro-4-pyridyl)methyl]- and N-[(1,2,3,6-tetrahydro-1-methyl-4-pyridyl)methyl]-2-hydroxy-2,2- diphenylacetamide (3e, 3f) exhibited the most potent inhibitory activity against bladder contraction (ED30 = 0.005 and 0.003 mg/kg i.v., respectively). Judging from the effect of 3e on detrusor contraction in vitro in guinea-pigs, it appeared that the inhibitory activity of 3e against bladder contraction in vivo was related mainly to its inhibitory activity against detrusor contraction in vitro induced with carbachol (antimuscarine-like activity). The selectivity (20-fold) of 3e between inhibitory activity against bladder contraction and mydriatic activity was greatly superior to that (0.48-fold) of oxybutynin. Compound 3e was synthesized by debenzylation (method E or F) of the corresponding N-[[1-(4-methoxybenzyl)-tetrahydro-4-pyridyl]methyl] derivative (3k), which was prepared by acylation (method B) of the corresponding (tetrahydro-4-pyridyl)methylamine (7k) or by reduction (method D) of the corresponding pyridinium chloride (14k) with NaBH4.

Acetamides↗
PubMed1994

[Thoracoscopic observation and diagnosis in cases of pleural, mediastinal, and pulmonary lesions].

Thoracoscopy was performed in a total of 424 patients at our institute from January 1970 to December 1993. The indications for thoracoscopy were pneumothorax (121 cases), primary lung cancer (98 cases), mediastinal tumor (45 cases), metastatic lung tumor (23 cases), pleuritis (35 cases), diffuse lung disease (38 cases), tuberculosis (20 cases), benign lung tumor (10 cases), and other (34 cases). By 1990, diagnostic thoracoscopy had been performed in 383 patients. Since 1991, thoracoscopy has been used therapeutically for spontaneous pneumothorax (24 cases), mediastinal and chest wall tumors (9 cases), pulmonary nodules (2 cases), and others (8 cases). Findings useful for diagnosis were obtained in 326 cases and biopsy was performed in 173 cases. Thoracoscopy was especially useful in the diagnosis of diffuse lung disease, pleuritis, and small pulmonary nodules. Recent advances in endoscopic equipment and refinement of thoracoscopic techniques have expanded the application of this procedure. Our experience indicates a markedly expanded role for thoracoscopy in the diagnosis and treatment of thoracic diseases, with less postoperative morbidity.

Humans↗
PubMed1994

A liquid-liquid blood-gas exchange for the treatment of acute respiratory failure. A new blood gas exchange using artificial blood as an oxygen carrier.

A new liquid-liquid blood gas exchange system was investigated using a venovenous low flow extracorporeal circuit. A 2 m2 hollow fiber dialyzer served as the interface of the blood and oxygen carrier (a 38 percent FC-43, perfluorocarbon emulsion in a buffered electrolyte solution), which was continuously recycled through a bubble oxygenator. Experiments were performed on five mongrel dogs under general anesthesia. Upon the arrest of spontaneous ventilation, the dogs' lungs were inflated with 50% oxygen gas under a positive pressure of 10 cmH2O. After 10 min of apnea the dogs' PaO2 decreased to 37 +/- 14 mmHg, and the extracorporeal circulation was started at 10 ml/min/kg b./w. At 15 min the PaO2 had risen to 80 +/- 41 mmHg and at 30 min to 121 +/- 17 mmHg. The oxygen transfer was 8.3 +/- 2.3 ml/min. The extracorporeal circulation was continued 5h, when PaO2 reached 156 +/- 90 mmHg, and PaCO2 148 +/- 43 mmHg, then stopped. Fifteen minutes later, the PaO2 had returned to 32 +/- 10 mmHg. These findings indicate that our blood gas exchange system can supply a sufficient amount of oxygen to the body under apnea with continuous positive airway pressure.

Animals↗
PubMed1994

[Effectiveness of a programme to improve housing conditions for elderly requiring supportive care in Edogawa-ku, Tokyo].

The programme in Edogawa-ku, Tokyo, for improvement of housing conditions for the elderly requiring supportive care, is unique in Japan in that it offers unlimited amount of benefits regardless of income status of beneficiaries. Between October, 1990, when the programme started, to March, 1992, total of 447 people utilized the programme. These 18 months were divided into three periods for comparative analysis of characteristics of users, details of improvement in housing conditions and cost (amount of benefits). The proportion of bed-ridden cases decreased during the later periods, with a corresponding increase in those who had improvements made to entrances and approaches to their residence. However, average cost of changes in housing features decreased in the later periods because there was less demand for expensive changes such as bathtub remodeling or installation of lifts on stairs. A survey by mail was conducted to find out the effect from the users' viewpoint. Valid responses were collected from 290 cases. Three aspects of improvement in housing conditions were assessed: improvement in daily activities, reduction in the care taker's burden, and reduction in the need for long-term institutional care. More than one-third of the users reported improvement in each of three aspects, and two-thirds had improvements in at least one out of the three items. There were intercorrelation among the three items, especially between improvement in daily activities and reduction of the care taker's burden. Analysis showed that improvements were reported in a greater proportion of those living alone or in a two-person household, those who utilized the programme following discharge from inpatient care, those who had their bathroom or bathtub remodeled, and those who had the more expensive changes made. Changes in entrances and approaches to the residence was correlated to an improvement in daily activities. Reduction in care-taker's burden was seen where stroke was the cause of being dependent and where a specially equipped bed was provided. Reduction in the need for long-term institutional care is related to family structure and number of rooms in the home, which are barriers to continuing home care.

Aged↗
PubMed1993

Crystallization and preliminary X-ray studies of wild type and catalytic-site mutant alpha-amylase from Bacillus subtilis.

Recombinant alpha-amylase (EC3.2.1.1) from Bacillus subtilis has been crystallized by the hanging drop vapor diffusion method using polyethylene glycol as precipitant. Crystals of wild-type protein diffract to at least 2.2 A resolution, and belong to the space group P2(1)2(1)2(1) with a = 72.2 A, b = 74.9 A, c = 116.1 A with probably one molecule in the asymmetric unit. A catalytic site mutant created by site-directed mutagenesis has also been grown as isomorphous crystals with a = 72.6 A, b = 74.4 A, c = 116.7 A. Structural studies of both wild-type and mutant proteins will provide a basis for understanding the catalytic mechanism of alpha-amylase.

Bacillus subtilis↗
PubMed1993

Clinical significance of measuring plasma concentrations of glutamine and glutamate in alcoholic liver diseases.

We investigated the significance of assaying plasma glutamine and glutamate concentrations in various liver diseases. Comparison was made with an aminogram in non-alcoholic liver disease. In alcoholic liver diseases, the plasma glutamate concentration showed a statistically significant elevation compared to the value in non-alcoholic liver diseases. In contrast, the plasma glutamine concentration was elevated in non-alcoholic liver diseases but showed no elevation in alcoholic liver diseases. The glutamate (Glu)/glutamine (Gln) ratio and plasma gamma-GT level correlated well in patients of alcoholic liver diseases. The Glu/Gln ratio became normal after alcohol abstinence. The results suggest that measuring the plasma concentrations of glutamine and glutamate may be a useful method to estimate the pathophysiological state of patients with alcoholic liver diseases.

Acute Disease↗
PubMed1993

Ethanol and hydrazine sulfate induced chronic hepatic injury in rats: the curative effect of administration of glucogenic amino acids.

There is a widespread belief that when ethanol is fed to rats for a long time, it produces only fatty degeneration without necrosis or fibrosis. In this study, hydrazine sulfate, an inhibitor of low Km ALDH and gluconeogenetic enzymes, was fed with ethanol to rats, and produced more serious pathological changes compared with those found in Lieber's model. Male Sprague-Dawley rats were fed with a low fat liquid diet as a basal diet with ethanol (4%, w/v) and hydrazine sulfate for 4 weeks. At the end of the experiment, plasma aminotransferase levels were found to be elevated. Histological examination showed not only fatty degeneration but also pericellular fibrosis. Therefore, we have evaluated the curative effect of glucogenic amino acids, alanine and glutamine, on this hepatic injury model and found them to be partially protective.

Alanine Transaminase↗
PubMed1993

Studies on the incidence of hepatocellular carcinoma in heavy drinkers with liver cirrhosis.

The incidence of hepatocellular carcinoma (HCC) in heavy drinkers who drank more than 130 g per day for more than 10 years, and non-drinkers with cirrhosis who were positive or negative hepatitis C virus (HCV) markers, was analyzed in order to evaluate the effect of a large amount of alcohol on the development of HCC. A parallel study was also conducted in some patients from the aspect of HCV genotypes. Among 57 heavy drinkers with liver cirrhosis, HCV marker was positive in 36 patients (C+Al group) and negative in 21 patients (Al-alone group). Eighty-one patients with liver cirrhosis of non-drinkers were positive for HCV markers (C-alone group). HCV infection was involved in 63% of heavy drinkers with cirrhosis and 44% of patients with HCC. The majority of HCC patients in the C+Al group was infected with HCV through routes other than blood transfusion. HCC developed at a younger age in patients of the C+Al group than in patients of the C-alone group without relation to history of blood transfusion. In more than a third of patients who had tattoos or used stimulants in the C+Al group, HCC developed without a history of blood transfusion. These results suggest that heavy drinking enhances the development of HCC. The HCV genotypes in patients with HCC were all type II, except for one case of type III and one unclassified. The mixed type of HCV was often found in patients who had a blood transfusion or tattoo, suggesting that there may be some correlation between the routes of HCV infection and the diversity of genotypes.

Adult↗