Search PubMed⌕ Search

Biomedical subjects

M Tamura

Publications and source records attributed to M Tamura.

At least 703 records · Page 39Linked to original sources
PubMed1990

[Effect of a spacer device used with metered dose inhaler].

Metered dose inhaler (MDI) is widely used in treatment of bronchial asthma. But adequate efficacy is not obtained if the patients use an improper technique of inhalation. The spacer device was designed to reduce such inhalation errors. Three types of spacers (pear type, tube type, paper spacer) were studied to confirm their usefulness in bronchial asthma. Bronchodilating effect of procaterol (10 micrograms/puff X 2) in conventional MDI or MDI with a spacer was evaluated. There were no significant difference in the effect on the pulmonary function after single inhalation of MDI with or without a spacer for 60 minutes. In regular use of MDI with a spacer for two weeks, PEFR and FEV1.0 were slightly improved. These results suggest that effect of MDI with a spacer may be more effective than MDI alone in regular use.

Administration, Inhalation↗
PubMed1990

[Ligation of the crura penis: surgical treatment for venous impotence].

Recently it has become clear that venous impotents account for a high percentage of all impotents. In venous impotents a decrease in outflow resistance is seen. We have aggressively performed operations on venous impotents to produce artificial outflow resistance. In this study, we performed ligations of the crura penis in 6 venous impotents. Five patients recovered from erectile dysfunction and 1 patient showed papaverine-induced full erection. There were few severe complications and the duration of operation was very short. This operation is thought to be a simple and effective treatment for venous impotence.

Adult↗
PubMed1990

[Histiocytosis X].

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed1990

[A case of pigeon breeder's lung].

A 34 year-old male pigeon breeder developed a sudden fever, cough, and dyspnea with diffuse nodular shadows on the chest X-ray film and computer tomogram. His symptoms and diffuse nodular shadows on the chest X-ray film improved and gallium (Ga) scintigram showed no accumulation of 67Ga-citrate in his lungs when examined after corticosteroid therapy. Serum precipitin against pigeon serum and pigeon dropping extracts could be detected. In his bronchoalveolar lavage (BAL) fluid, total cell count, mainly lymphocytes, were increased. OKT8(+)-HLA-DR+T cells were dominant in the lymphocyte subpopulation of the BAL fluid. Pathological examination of transbronchial lung biopsy specimen showed interstitial pneumonia. Blastogenic response of peripheral blood mononuclear cells when cultured with pigeon serum could not be observed, which suggested suppressive effects of lymphocyte blastogenesis by corticosteroid therapy. An inhalation provocation test with pigeon serum was performed. The patient developed fever, leucocytosis, hypoxemia and decreased vital capacity after the inhalation provocation test. Consequently, the case was diagnosed as a pigeon breeder's lung.

Adult↗
PubMed1990

[Experimental study of cellular response on the intraocular lens surface in terms of the presence and distribution of fibronectin].

An immunohistochemical study was performed to observe cellular proliferation on the surface of implanted intraocular lenses (IOLs) in rabbit eyes. Rabbits were killed 3-28 days postoperatively. The removed IOLs were examined by an immunoperoxidase staining method using anti-fibronectin antibodies. The immunoreactivity for fibronectin was detected in macrophages and multinucleated giant cells attached to the IOL surface. Prominent stains were observed in these cells 1 week after the operation, and staining for fibronectin was less intense in the specimens 2 and 4 weeks after implantation. Fibronectin is produced by macrophages and multinucleated giant cells on the IOL surface, and might play important role in cellular adhesion and motility. Fibronectin immunoreactivity decreased with time and it may be related to cellular activity.

Animals↗
PubMed1989

Stabilization of the superoxide-generating respiratory burst oxidase of human neutrophil plasma membrane by crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide.

The superoxide-generating respiratory burst oxidase (NADPH-oxidase) of neutrophil plasma membranes is known to be highly unstable. In an attempt to stabilize the enzyme, we investigated the effect of crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The stability of superoxide-generating activity of plasma membrane was significantly enhanced by crosslinking. The half-life (t1/2) of the activity at 37 degrees C in the absence of crosslinker was about 2 min. Crosslinking extended the t1/2 significantly. Crosslinked material exhibited a biphasic loss of activity: about half was lost in each phase with respective t1/2 values of 20 and 240 min. The lifetime of the crosslinked material at 37 degrees C was further extended (about sixfold) with 30% glycerol, and the crosslinked material was completely stable for more than 2 weeks if stored on ice. Crosslinking also stabilized the activity to the effects of high salt and detergent, both of which have inactivating effects on the oxidase. In addition, crosslinking stabilizes not only the Vm but also the Km of the enzyme, which was noted to increase upon storage in the absence of crosslinking. Unlike the native material, the crosslinked oxidase failed to be stimulated (and in fact was inhibited) by phosphatidylserine, recently reported to be an activator of the oxidase (Tamura et al. (1988) J. Biol. Chem. 263, 17,621-17,626). The crosslinked plasma membrane provides a useful stabilized system for kinetic studies. When the activated plasma membrane was treated with EDC, the stabilized oxidase could not be solubilized effectively using detergents, since greater than 95% of the activity remained with the pellet following centrifugation, perhaps due to crosslinking to the cytoskeleton. However, when the activity was first detergent-solubilized, the soluble activity was also stabilized by EDC. This solubilized, crosslinked material may provide useful starting material for subsequent isolation and characterization of a stabilized active NADPH-oxidase.

Carbodiimides↗
PubMed1989

The oxygen dependence of the energy state of cardiac tissue: 31P-NMR and optical measurement of myoglobin in perfused rat heart.

The relationship between the energy state and intracellular oxygen concentration was established with cardiac tissue, where the former could be monitored by 31P-NMR and the latter by optical method for myoglobin absorption. The ratio of creatinephosphate to inorganic phosphate, PCr/Pi, started to fall at higher intracellular oxygen concentration than oxygen consumption (10IM). The pH shift measured by frequency shift of Pi paralleled the increase of lactate-release, of which half maximum was approximately 3IM. The critical oxygen concentrations differed nearly 5-fold when determined by energy state and oxygen consumption.

Adenine Nucleotides↗
PubMed1989

Near infrared quadruple wavelength spectrophotometry of the rat head.

A quadruple wavelength method to monitor the changes in concentration of oxygenated and deoxygenated hemoglobin and the redox state of cytochrome oxidase within a living tissue is presented. The expected advantages of this technique over the triple wavelength method are (i) that it can compensate for the light scattering change of tissue itself or for instabilities of light source and photomultiplier, (ii) that it can treat the optical properties of the red blood cell in a tissue in the same way as in an in vitro model system, and (iii) that it requires no estimation of the absorption coefficient of cytochrome oxidase in situ.

Animals↗
PubMed1989

The oxygen dependency of the redox state of heme and copper in cytochrome oxidase in vitro.

The oxidation-reduction state of cytochrome oxidase in isolated mitochondria at low oxygen concentrations was measured by the use of leghemoglobin as an oxygen indicator. P50 a + a3 varied with energy state as well as the respiratory rate. In contrast to heme a + a3, copper was slower to reduce than heme a + a3. The P50Cu of 8 x 10(-8)M in State 4 and 7.4 x 10(-8)M in State 3 was independent of both the energy state and the respiratory rate.

Aerobiosis↗
PubMed1989

Large dose fraction radiotherapy in the treatment of glioblastoma.

Twenty-four adults with glioblastoma multiforme (astrocytoma, grade 4) underwent postoperative large dose fraction radiotherapy (LDFR; 5 Gy twice weekly) with Linac X-rays. The outcome in this group was compared with that of 26 patients who received conventional fractionated radiotherapy (CFR; 2 Gy 5 times weekly). The time, dose, and fractionation (TDF) factor was about 100 in both groups. The survival rates following LDFR and CFR were, respectively, 63% vs 65% at 1 year; 36% vs 8% at 2 years; 17% vs 4% at 3 years; and 4% vs 0% at 5 years. Although the survival curve for LDFR was superior to that for CFR, the difference was not statistically significant. Autopsies of nine LDFR and 13 CFR patients showed no residual tumor in one case and no cases, respectively; small residual tumor in three cases in each group; extensive coagulation necrosis of the tumor and surrounding brain tissue in one LDFR and four CFR patients; tumor proliferation in three LDFR and four CFR cases; and mixed glioblastoma and fibrosarcoma in one LDFR and two CFR patients. These results suggest that maximum tumor removal followed by LDFR may offer a better prognosis for patients with glioblastoma than that offered by surgery plus CFR.

Adult↗
PubMed1989

Undifferentiated gliomas of the brain stem.

Undifferentiated gliomas of the brain stem were confirmed surgically in two young children. The patients were treated by aggressive irradiation of the entire neuraxis, similar to that administered for medulloblastoma. Therapy resulted in a good prognosis and there was no tumor recurrence.

Brain Neoplasms↗
PubMed1989

Vasoconstrictor effect of endothelin on the canine coronary artery: is a novel endogenous peptide involved in regulating myocardial blood flow and coronary spasm?

We examined the effect of endothelin on the canine coronary artery (N = 20). The left circumflex coronary artery was cannulated and perfused with arterial blood at constant pressure. Coronary blood flow was monitored by an electromagnetic flowmeter. Intracoronary endothelin provoked a vasoconstriction that was dose-dependent. At a dose of 500 pmol, coronary blood flow was reduced remarkably (91.0 +/- 5.4%, n = 4), and endothelin subsequently produced a fall in systemic blood pressure and ST elevation in the electrocardiogram. At a dose of 100 pmol (n = 9), coronary flow decreased from 16.4 +/- 1.5 ml/min to 12.5 +/- 1.5 ml/min (p less than 0.001) and coronary vascular resistance increased from 6.3 +/- 0.8 mm Hg/ml/min to 9.9 +/- 1.9 mm Hg/ml/min (p less than 0.005). A cumulative dose-response curve to endothelin was obtained and the curves were shifted to the right after both verapamil and nifedipine administration. Therefore endothelin has a potent vasoconstrictor action that is attenuated by the calcium-channel blocker.

Animals↗
PubMed1989

Electron spin resonance spectrum of Tyr-151 free radical formed in reactions of sperm whale metmyoglobin with ethyl hydroperoxide and potassium irridate.

A five-line ESR spectrum was observed at room temperature in reactions of sperm whale metmyoglobin with ethyl hydroperoxide (EtOOH) at pH 9.5 and with potassium irridate at pH's 7.0 and 9.5. A spectrum with the same g value and hyperfine splitting constant appeared in a reaction of sperm whale apomyoglobin with potassium irridate and was assigned to a tyrosyl radical on the basis of optical spectrum data obtained under the same reaction conditions. It was concluded that this radical arose from Tyr-151 for the following reasons. (i) This ESR spectrum could not be observed in the reaction of horse heart metmyoglobin, which lacks Tyr-151. (ii) Sperm whale metmyoglobin no longer gave this spectrum when treated with tetranitromethane (TNM) under conditions in which approximately one tyrosine is lost in sperm whale metmyoglobin but none is lost in horse heart metmyoglobin. (iii) A complex ESR spectrum observed in the reaction of sperm whale metmyoglobin with EtOOH at neutral pH was found to be a mixture of this five-line spectrum and one arising from an unidentified free radical formed in the reaction of horse heart metmyoglobin with EtOOH. The TNM-treated sperm whale metmyoglobin gave the same ESR spectrum as that observed in the reaction of horse heart metmyoglobin with EtOOH.

Animals↗
PubMed1989

The effect of platelet-derived growth factor on phagocytosis of cultured human trabecular cells.

Platelet-derived growth factor (PDGF) enhanced the phagocytic activity of cultured human trabecular cells in a dose-dependent manner (5-40 ng ml-1). By transmission and scanning electron microscopy, microvilli on the cell surface were shown to make contact with latex particles. Subsequently the cell surface invaginated and engulfed them. By indirect immunofluorescence, actin was found to form stress fibers in PDGF-free cells. PDGF-treated cells were stained in thread-like patterns on the cell surface. In addition to this image, membrane ruffles and actin ribbons were also observed. These findings suggest that PDGF may serve to facilitate phagocytosis and migration of trabecular cells by modifying trabecular cell actin.

Actin Cytoskeleton↗
PubMed1989

Effect of moxisylyte hydrochloride on isolated human penile corpus cavernosum tissue.

The effect of moxisylyte hydrochloride on isolated human penile corpus cavernosum tissue was investigated and compared with other a-adrenergic antagonists. Moxisylyte produced a concentration-dependent relaxation of a norepinephrine-induced (1 x 10(-5) M) contraction of the corpus cavernosum tissue. Pretreatment with 1 x 10(-6) M doses of moxisylyte reduced competitively the norepinephrine-induced contraction. The competitive effect of prazosin was strongest among four tested agents, followed by phentolamine, moxisylyte, and then yohimbine. The activity ratio for each antagonist is 2.4 for moxisylyte, as compared with 28.2 for prazosin, 6.7 for phentolamine, and 1.6 for yohimbine respectively. Moxisylyte hydrochloride is an agent with potential clinical and research uses capable of producing erection when injected intra-cavernously.

Adolescent↗
PubMed1989

Prolonged survival of mice with myeloid leukemia by subcutaneous injection of recombinant human G-CSF.

We studied the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on leukemia development and survival of mice with leukemia by using a radiation-induced myeloid leukemia cell line (C2M) with A-type phosphoglycerate kinase (PGK) as marker isoenzyme. C3H/He mice with B-type PGK were inoculated with 2 x 10(6) C2M cells through the tail vein. From the next day, they received a daily subcutaneous injection of 1 microgram rhG-CSF or control solution. The survival of rhG-CSF-treated recipients of C2M was significantly longer than control-solution-treated recipients. In rhG-CSF-treated recipients, not only spleen weight but also the number of blasts in hemopoietic organs was less than those in control recipients. While there was a remarkable decrease in bone marrow content of CFU-GM in control recipients, the content in rhG-CSF-treated recipients was comparable to that in normal mice. A reduced bone marrow and spleen content of leukemic colony-forming cells (L-CFU) was observed in rhG-CSF-treated recipients in comparison with control recipients. The electrophoretic analysis of PGK phenotypes of hemopoietic organs indicated the delayed appearance of A-type PGK from C2M cells in rhG-CSF-treated recipients. From these findings, we concluded that the injection of rhG-CSF delayed the onset of leukemia and improved the survival and several hematological parameters by suppressing C2M cells in recipient mice.

Animals↗