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Biomedical subjects

H Hirose

Publications and source records attributed to H Hirose.

At least 19 recordsLinked to original sources
PubMed1992

Arachidonic acid metabolites and alpha 2-adrenoceptor-mediated glucagon secretion in rats.

Effects of phospholipase A2 inhibitor, cyclooxygenase inhibitor and lipoxygenase inhibitor on glucagon secretion induced by the alpha 2-adrenergic agonist clonidine were studied in the isolated perfused rat pancreas. The phospholipase A2 inhibitor mepacrine at 25 and 50 mumol/l significantly inhibited glucagon secretion induced by 0.1 mumol/l clonidine (P less than 0.01, respectively), whereas 5 mumol/l mepacrine did not affect clonidine-induced glucagon secretion. Also, both 100 mumol/l acetylsalicylic acid (cyclooxygenase inhibitor) and 100 mumol/l caffeic acid (lipoxygenase inhibitor) significantly inhibited clonidine-induced glucagon secretion (P less than 0.01, respectively), whereas neither 10 mumol/l acetylsalicylic acid nor 10 mumol/l caffeic acid affected clonidine-induced glucagon secretion. None of the drugs at the tested concentrations affected insulin secretion at a glucose concentration of 5.5 mmol/l. These results suggest that not only cyclooxygenase metabolites but also lipoxygenase metabolites are involved in the stimulation of glucagon secretion mediated through the alpha 2-adrenergic receptors in perfused rat pancreas.

Animals↗
PubMed1992

[Dynamic process of colonization by Haemophilus influenzae in children--is H. influenzae normal flora in the throat?].

Eighty-seven oropharyngeal isolates of Haemophilus influenzae were obtained by two time cultures six months apart from a total of 288 children who attend a kindergarten. We analyzed the strains by comparing their serotypes, biotypes, beta-lactamase activity and by performing electrophoresis of outer membrane proteins on polyacrylamide gels. Only nineteen strains were not identical, the rest of the 68 strains were classified into 23 types. During 6 months at least 15 types of strains lost from this group and 21 types of new strains were obtained. There were no children who had identical pairs of H. influenzae in their oropharynx during the 6 months. The classification of strains in oropharynx suggested that person-to-person transmission of nontypable H. influenzae can occur. We concluded that oropharyngeal colonization by nontypable H. influenzae is not a normal flora in children.

Bacterial Outer Membrane Proteins↗
PubMed1992

Effect of hyperlipidemia on cardiovascular responses to adrenergic stimulation in piglets.

This study was designed to assess the effect of hyperlipidemia on cardiovascular responses to adrenergic stimulation in a porcine model. Four-week-old piglets (n = 10) were divided into two groups; one fed a control diet and the other was fed an atherogenic diet for 8 weeks. Cardiovascular responses were evaluated to both norepinephrine (NE; 0.5 and 2.5 micrograms/kg) and isoproterenol (ISO; 0.1 and 0.5 microgram/kg) from simultaneous recordings of femoral arterial pressure, heart rate, left intraventricular pressure and left intraventricular dP/dt. It was found that no significant difference in the baseline values of cardiovascular function was observed between the control and hyperlipidemic groups. However, in the hyperlipidemic group as compared with the control group: 1) arterial blood pressure responses to NE were significantly increased (P less than 0.05), 2) cardiac contractile responses to NE and ISO were significantly potentiated (P less than 0.05), and 3) reflex bradycardia in response to increasing arterial blood pressure did not occur. These findings indicate that hyperlipidemia can potentiate the cardiovascular responses to adrenergic stimulation, whereas reflex cardiovascular regulation is somewhat altered by hyperlipidemia. Conceivably, these observations may have relevance to the possible role of the mechanism of the interaction of hyperlipidemia and hypertension in atherogenesis.

Analysis of Variance↗
PubMed1992

Alpha-2 adrenergic agonism stimulates islet glucagon release from perfused rat pancreas: possible involvement of alpha-2A adrenergic receptor subtype.

Although insulin release is known to be inhibited by alpha-2 adrenergic agonism, the effect of alpha adrenergic agonism on islet glucagon release remains controversial. Alpha-2 adrenoceptors are subdivided into alpha-2A and alpha-2B subtypes using receptor binding methods or cloning methodology. This study was designed to confirm the involvement of the alpha-2 adrenoceptor and its subtypes in glucagon release from the isolated, perfused rat pancreas. Both the alpha-2A preferential agonist oxymetazoline and the non-subtype-selective alpha-2 agonist clonidine induced concentration-dependent stimulation of glucagon release, starting at 10(-8) and 10(-7) mol/l, respectively (p < 0.01). In contrast, neither of the two alpha-1 selective agonists, methoxamine and phenylephrine, at concentrations up to 10(-6) mol/l affected glucagon release. Furthermore, the non-subtype-selective alpha-2 antagonist rauwolscine at concentrations of 10(-6) and 10(-5) mol/l and the alpha-1 and alpha-2A selective antagonist WB-4101 at 10(-5) mol/l showed significant antagonism of 10(-7) mol/l clonidine-induced glucagon release versus corresponding controls. Neither the alpha-1 and alpha-2B selective antagonist prazosin nor the alpha-2B preferential antagonist chlorpromazine, at concentrations up to 10(-5) mol/l, antagonized the effects of clonidine. None of the eight drugs, at the concentrations tested, affected insulin release with 5.5 mmol/l glucose. These results suggest that in rats islet glucagon release induced by alpha adrenoceptor agonism is mediated through alpha-2 adrenoceptors, possibly the alpha-2A subtype.

Adrenergic alpha-Agonists↗
PubMed1992

Synthesis of radiopaque cyclophosphazene monomers, properties of bulk polymers and their application to composite resin.

A series of studies was conducted on the synthesis of polyfunctional cyclophosphazene monomers having radiopacity and a polymerization group in the same molecule, and their properties and applicability to composite resin were examined. Using octachlorocyclotetraphosphazene, P4N4Cl8 (4PNC), monomers were synthesized by replacing the 1-4 of chlorine (Cl) with p-bromophenol (BrC6H4OH, BrPh), and replacing the residual number of Cl, 7-4, with 2-hydroxyethyl methacrylate [CH2:C(CH3)COOCH2CH2OH](HEMA), so as to obtain four kinds of transparent monomer having radiopacity and a polymerization group in the same molecule. We then analyzed these monomers and examined their physical properties after bulk-polymerization. Next, we prepared an organic composite filler using 4PN-(BrPh)3-(EMA)5 monomer, which showed comparatively good radiopacity, to produce a new experimental radiopaque composite resin. Although radiopacity improved in accordance with the increase in the number of BrPh molecules replaced, the mechanical properties of the polymer became poorer. Similarly it was proved that the radiopacity of composite resin made with 4PN-(BrPh)3-(EMA)5 monomer was equivalent or even superior, compared with the radiopacity of the front tooth. Consequently, it was shown that these synthesized monomers can be applied to visible light-cured radiopaque composite resin.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1992

[An investigation of the recognition process for jukugo by use of priming paradigms].

Three experiments were conducted to examine the recognition process of the jukugo (two-kanji-compound word) from the following three points of view: (1) how jukugos are retrieved from memory (Exp. 1), (2) how jukugos are activated in the retrieval process (Exp. 2), and (3) how the representation of jukugos is structured in memory (Exp. 3). The experiments were carried out using priming paradigms in which subjects performed a lexical decision task. The results of Exp. 1 and Exp. 2 showed that the first kanji was used as retrieval cue for each jukugo and the activation of the first kanji facilitated the identification of jukugo in terms of meaning. In Exp. 3, it was suggested that the lexicon of jukugo was formed in such a structure that several jukugos containing in common the same first kanji are tied together, centering on the first kanji.

Adult↗
PubMed1992

Evaluation of right ventricular function by regional wall motion analysis in patients after correction of tetralogy of Fallot. Comparison of transventricular and nontransventricular repairs.

Right ventricular function was assessed by regional wall motion analysis and by global function in 62 patients after repair for tetralogy of Fallot. Its relation to surgical procedures, with special attention to right ventriculotomy, was investigated. Patients were classified as follows: group Ia (n = 17), transpulmonary-transatrial repair without right ventriculotomy; group Ib (n = 22), transpulmonary-transatrial repair with minimal right ventriculotomy and small transannular patch; and group II (n = 23), transventricular repair with or without transannular patch. For regional wall motion analysis, fractional area change was used for three anterior parts obtained from hemiaxis area analysis of the lateral right ventriculogram. Ejection fractions were used for global right ventricular function. Functional assessment was done both at rest and during isoproterenol infusion, which is a stress test to evaluate cardiac functional reserve. At rest, group Ia showed better right ventricular anterior wall motion as well as global ejection fraction than did group II. Group Ib showed a global ejection fraction comparable to group Ia, with better regional wall motion in the middle anterior part of the right ventricle despite the depressed upper and lower anterior parts of the right ventricle. Group II showed depressed wall motion of the middle anterior part and the resultant impaired global ejection fraction. During isoproterenol infusion, group Ia showed significant increase in fractional area change of all anterior parts and in global ejection fraction. Group Ib showed significant increases in fractional area change at the middle and lower parts and in global ejection fraction comparable with group Ia. Otherwise, group II showed no significant change in fractional area change, or in global ejection fraction, at the upper and middle parts. These results indicated that transpulmonary-transatrial repair for tetralogy of Fallot provided better postoperative global right ventricular function and its reserve, with less impaired regional wall motion, than did the transventricular repair.

Cardiac Catheterization↗
PubMed1992

[A case of thymoma with thymic cyst].

A 43-year-old man was pointed out an abnormal shadow on chest X-ray film. Chest CT showed a solid mass and a cyst at anterior superior mediastinum. Operation revealed a capsulated thymoma and a multilocular thymic cyst. PTH and CA19-9 level in the cystic fluid was elevated. Histological examination demonstrated the clear separation of the mixed type thymoma and the thymic cyst. There were few reports for cases of thymoma with a thymic cyst.

Adult↗
PubMed1992

[A case of invasive thymoma with retroperitoneal recurrence].

A case of invasive thymoma with retroperitoneal recurrence is reported. A 55-year-old man with invasive thymoma (Masaokas classification, Stage IVa) underwent thymo-thymectomy, partial resection of left upper lobe, resection of phrenic nerve and partial resection of parietal pleura on March 14, 1989. Histological findings revealed thymoma with predominantly lymphocytic type. Two years after the operation, the tumor of retroperitoneal recurrence was discovered in abdominal CT. This retroperitoneal tumor was huge in size (16 x 12 cm) and extended into posterior mediastinum via aortic hiatus. The patient underwent resection of tumor through thoracotomy and laparotomy on April 23, 1991, after two cycles of chemotherapy. Histological findings revealed thymoma with predominantly lymphocytic type. This case was rare among patients with recurrence of thymoma as far as the site of recurrence is concerned.

Humans↗
PubMed1992

[Modified technique for chronic tricuspid regurgitation in rabbits and evaluation of intestinal malabsorption in the chronic stage of this model].

UNLABELLED: One of pathophysiological processes in cardiac cachexia with severe congestive cardiac failure is malabsorption in the intestine. This malabsorption might be caused by high venous pressure in the intestine, following congestive liver due to congestive cardiac failure. However, this has not been proved experimentally yet. In this experiment, rabbits were utilized because their body weights are relatively equal and their life cycle is shorter than that of dogs, for which experimental procedure has been established. Our purpose was first, to establish the technique which can produce tricuspid regurgitation (TR) in rabbits, and secondly, to examine the degree of malabsorption in these animals in the chronic stage of TR. SURGICAL TECHNIQUE: The TR rabbits (n = 4) were provided by means of division of the chordae of the tricuspid valve through the 4th intercostal space in the right thoracotomy. Division of the chordae was performed through the right atrial incision under direct vision while employing total temporary inflow occlusion. The duration of inflow occlusion varied from one to two minutes. RESULT: The mean of the peak right atrial pressure before the procedure was 6.5 mmHg, that just after the procedure was 16.1 mmHg, and that two to four months after the procedure was 17.0 mmHg. The peak right atrial pressure just after the procedure were higher than those before the procedure, and the peak right atrial pressure two to four months after the procedure were also higher than those before the procedure in all rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Preservation of the heart with University of Wisconsin solution--hemodynamic and morphological evaluation in a canine heterotopically transplanted heart].

University of Wisconsin (UW) solution has been reported to extend the safe cold ischemic time in the preservation of the liver, kidney and pancreas. However, there have been few reports of safe cold ischemic time in heart preservation with UW solution. The purpose of this study was to find whether UW solution can extend the safe cold ischemic time in cardiac transplantation in dogs. Heterotopic cardiac transplantation was performed in mongrel dogs after cold ischemic preservation of the hearts with UW solution, ischemic time 8, 16 and 24 hours (Gr.UW8, Gr.UW16 and Gr.UW24, respectively) and with GIK solution, ischemic time 4 hours (Gr.G4) which is considered the safe cold ischemic time in clinical cardiac transplantation. The following was studied: 1) Emax of the LV, myocardial contraction, by pressure-volume curve with the volume measured conductance catheter method, 2) myocardial tissue blood flow of the LV (MTBF), with laser doppler tissue flow meter, 3) serum CPK and electron microscopical evaluation. Emax and MTBF were measured before transplantation and after reperfusion. Their results were expressed as percentage of the values before transplantation. As results, after 120 minutes from reperfusion, Emax was recovered to 94 +/- 13% in Gr.G4, 104 +/- 11% in Gr.UW8, 67 +/- 22% in Gr.UW16 and 66 +/- 16% in Gr.UW24. Emax in Gr.G4 and Gr.UW8 were significantly (p less than 0.01) higher than that in Gr.UW16 and Gr.UW24. After 120 minutes from reperfusion, MTBF was recovered to 90 +/- 19% in Gr.G4, 98 +/- 9% in Gr.UW8, 63 +/- 19% in Gr.UW16 and 61 +/- 6% in Gr.UW24.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1991

Local formation and degradation of endothelin-1 in guinea pig airway tissues.

Endothelin(ET)-1 and big ET-1 caused potent and sustained constriction of isolated guinea pig bronchus. The response to ET-1 was enhanced by phosphoramidon in a simple dose-related manner (0.01-1000 microM), while the response to big ET-1 was enhanced at lower doses (0.01-0.1 microM) but was suppressed at higher doses (100-1000 microM) of phosphoramidon. Big ET-1, when given intravenously (i.v.) to anesthetized guinea pigs, increased both bronchopulmonary inflation pressure and mean arterial blood pressure (2.5, 5, 10 nmol/kg i.v.). The pressor response to big ET-1 was attenuated by phosphoramidon dose-relatedly, while the pulmonary response was modified in a complex fashion composed of delayed onset and prolonged duration of action. These results suggest that ET converting as well as degrading enzymes coexist in the airway tissue and both enzymes are sensitive to phosphoramidon, so that phosphoramidon acts bifunctionally to reduce and stimulate the airway responses to big ET-1.

Animals↗
PubMed1991

Clinical study of left atrial compliance and left atrial volume in mitral stenosis.

We studied left atrial compliance and left atrial volume in 21 patients with mitral stenosis showing a normal sinus rhythm. 1) A significant (p less than 0.001) negative linear correlation of r = 0.72 was found between the mitral valve area (MVA) and left atrial mean pressure (LAm). 2) A significant (p less than 0.005) positive linear correlation of r = 0.60 was found between MVA and left atrial compliance (delta V/delta P). 3) A significant (p less than 0.001) hyperbolic correlation of r = 0.73 was found between LAm and delta V/delta P. 4) A significant (p less than 0.001) hyperbolic correlation of r = 0.65 was found between left atrial specific compliance (delta V/delta P/LAVmax. LAVmax: left atrial maximum volume) and left atrial mean volume. 5) These findings led to the conclusion that in patients with mitral stenosis showing a normal sinus rhythm, left atrial compliance was decreased in patients whose left atrial volume was increased, and the decrease of left atrial compliance was related to narrowing of the mitral valve area and elevation of the left atrial pressure.

Adult↗
PubMed1991

Prediction of contractile reversibility in impaired left ventricular wall motion following coronary artery bypass grafting.

Interventional left vertriculograms (LVGs) using postextrasystolic potentiation (PESP), nitroglycerin (TNG) and a combination of both were analyzed in order to decide the degree of efficacy of each intervention as a predictor of reversibility in impaired left ventricular segments. Segmental wall motion (SWM) in less severely impaired segments increased to the normal range and SWM in severely impaired segments increased but remained in the abnormal range after CABG. The effects of both PESP and TNG on SWM in impaired segments correlated (r = 0.78 and 0.78) with that of CABG. The increase in SWM due to TNG + PESP was significantly (p < 0.01) greater than that due to either PESP or TNG alone or that of CABG. Either PESP or TNG was clinically reliable for prediction of contractile reversibility in the segments with impaired wall motion prior to CABG. Including the global left ventricular function, PESP reflected the efficacy of CABG more sufficiently than TNG. TNG + PESP provoked more contractile reserve and exaggerated the results of CABG, but may predict reversibility in severely reduced wall motion.

Adult↗
PubMed1991

Serodiagnosis of cancer by using Candida cytochrome c recognized by human monoclonal antibody HB4C5.

Cytochrome c from various sources, such as Candida krusei, yeast, horse, and cattle, was found to be recognized by human monoclonal antibody HB4C5 specific to lung cancer. Therefore, the cytochrome c was applied to the measurement of antibody amount in patient sera with a similar reactivity to the antibody HB4C5 for serodiagnosis of cancer. The cytochrome c from Candida krusei was most valuable for the serodiagnosis of various cancers, and the yeast cytochrome c was also useful. However, horse and bovine cytochrome c did not react with antibody of the cancer patients. By using Candida cytochrome c lung, bile duct, esophagus, and liver cancers were detected at high rates of more than 50%. In the case of lung cancer, the detection rates of small-cell, squamous, large-cell and adenocarcinoma were 78%, 63%, 100%, and 34%, respectively. The rate for small-cell carcinoma was higher than that with the currently used NSE assay system, and the rate for squamous carcinoma was comparable to that with the SCC assay system, although the system using cytochrome c did not show similar reactivity to that with the SCC system. Furthermore, lung cancer was detected at early stages by using cytochrome c, and even in the case of adenocarcinoma, the rate at early stages with the cytochrome c system was higher than that with the CEA assay system. On the other hand, false positive rates of benign diseases and normal were low--8% and 2%, respectively.

Antibodies, Monoclonal↗
PubMed1991

Detection of lung cancer in clinical specimens using a human monoclonal antibody HB4C5-clone 3.

Biopsies of 18 patients with lung cancer and cellular specimens of 21 lung cancer patients were analyzed with human monoclonal antibody HB4C5-clone 3 using avidin-biotin-peroxidase techniques. Analyses with the biopsies showed that HB4C5-clone 3 reacted with 16 of 18 biopsy specimens at a high rate of about 90% and reacted with all specimens of five adenocarcinoma tissues, five of six squamous cell carcinomas, two of three large cell carcinomas, both specimens of small cell carcinomas, and both of the other types of carcinomas. In all the reactive cases, the monoclonal antibody was reactive with greater than 50% of cancer cells. With cellular specimens of lung cancer patients, HB4C5-clone 3 reacted with 7 of 13 adenocarcinoma specimens, two of six squamous cell carcinomas, and one of two small cell carcinomas. The immunoreaction with HB4C5-clone 3 was observed in sites of the cytoplasm of cancer cells. From these data, HB4C5-clone 3 is considered to be of potential use in diagnoses of tissues and cellular specimens of lung cancer.

Adenocarcinoma↗