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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 649 records · Page 36Linked to original sources
PubMed1993

Exercise-induced silent myocardial ischemia in single vessel coronary artery disease associated with Q wave infarction. Assessment by thallium 201 single-photon emission computed tomography.

PURPOSE: To examine the relationship between the symptom of ischemia and the amount of abnormally perfused myocardium, coronary arteriography and exercise and redistribution thallium 201 single-photon emission computed tomography (SPECT) were analyzed. MATERIALS AND METHODS: The study group consisted of 153 patients with single-vessel coronary artery disease; 53 patients had no pathologic Q waves (group 1) and 100 patients had pathologic Q waves consistent with the area supplied by the diseased vessel (group 2). Twenty normal subjects were used as control subjects. The apical, mid, and basal left ventricular levels of the short-axis view and apical portion of the long-axis view were divided into 20 segments, and segmental images were scored blindly on a 0 (normal) to 4 (severely reduced uptake) scale. The redistribution score was defined as the thallium 201 defect score of exercise subtracted from that of the redistribution image and was used as a measure of the amount of ischemic myocardium. RESULTS: The redistribution score in 20 control subjects was 0.20 +/- 2.06, and the upper limit of normal redistribution score was defined as mean + 2 x SD (4.32). In group 1, 40 of 53 patients had a redistribution score above the normal range. In group 2, 34 of 100 patients had a redistribution score above the normal range. Of 40 patients in group 1, angina during exercise was observed in 22 patients (55 percent). Twenty-two patients who had angina had a redistribution score of 15.2 +/- 6.7, while those who did not have angina had a score of 13.7 +/- 5.2 (p = NS). Of 34 patients in group 2, angina was observed in 10 patients (29 percent) during exercise. Ten patients with angina had a redistribution score of 10.1 +/- 4.4, and those without angina had a score of 9.9 +/- 3.4 (p = NS). CONCLUSION: Thus, the incidence of silent ischemia without the Q wave infarct zone was found to be higher than that within the ischemic zone without Q wave. Patients with silent and symptomatic ischemia during exercise have similar amounts of ischemic myocardium demonstrated by tomographic thallium 201 imaging; this was found in patients who had Q wave infarction and in those who did not.

Angina Pectoris↗
PubMed1993

[Learning dysfunction model in ddY mouse and IgG].

Mice of the ddy strain having once received an electric shock in the dark chamber of a passive avoidance response unit were divided into two groups according to their behavior pattern. It is suggested that learning function of the mice which did not avoid the dark chamber (negative-avoidance mice: N-mice) was disturbed. After an injection of IgG obtained from the positive-avoidance mice (P-mice) into the N-mice, these prior N-mice displayed the behavior pattern similar to that of P-mice following an application of electric shock. It was found that the sugar chain structure of N-mouse IgG was different from that of P-mouse IgG. This result indicates that the sugar chain structure is related to the learning ability of ddy mice.

Animals↗
PubMed1993

Localization of basic fibroblast growth factor (bFGF)-like immunoreactivity in neural circuits innervating the gastrocnemius muscle, with reference to the direction of bFGF transport.

An antiserum against basic fibroblast growth factor (bFGF), characterized by immunoblot, was firstly used to immunolocalize bFGF-like materials in dorsal root ganglion (DRG) neurons, spinal motoneurons and their processes innervating the gastrocnemius muscle, and then secondly to determine the direction of bFGF transport in the processes by nerve ligation or nerve section experiments. Light and electron-microscopic immunohistochemistry revealed that significant numbers of DRG neurons (mainly of the large type), spinal motoneurons and their processes supplying the muscle are immunoreactive for bFGF, and that the bFGF neurons have diffuse immunoreaction deposits over the entire cytoplasmic areas except for the Golgi complex, mitochondria and microfilaments. Nerve terminals and glial processes with bFGF were rarely seen in contact with or in close apposition to the immunopositive neurons. At sixteen hours, 3 days and 7 days after unilateral ligation or transection of the sciatic nerve, bFGF fibers accumulated in a time-dependent way in the proximal but not in the distal stump; nerve transection caused a more intense accumulation of bFGF-immunoreactive fibers than did nerve ligation. These findings suggest that bFGF in large DRG neurons and motoneurons is transported anterogradely into the peripheral tissue, possibly without being incorporated into secretory granules or synaptic vesicles. They raise the possibility that bFGF within the transected nerve fibers is more actively conveyed during regeneration than in the ligated nerve fibers.

Animals↗
PubMed1993

Fatal pneumomediastinum in dermatomyositis without creatine kinase elevation.

A 41-year-old woman developed fatal pneumomediastinum in the course of dermatomyositis. One characteristic feature of this patient was the relatively mild myositis with slight elevation of serum creatine kinase. In a literature review, some of the patients with dermatomyositis, but not polymyositis, with a very slight elevation of serum creatine kinase tended to develop spontaneous pneumomediastinum during corticosteroid therapy. Since pneumomediastinum is a highly fatal complication in patients with dermatomyositis, only slight elevation of creatine kinase could be a marker for poor prognosis. Thus, mild/minimal myositis in patients with dermatomyositis should be carefully observed irrespective of corticosteroid therapy.

Adrenal Cortex Hormones↗
PubMed1993

Glass ceramic augmentation of the acetabulum. Total hip arthroplasties in 24 dogs.

Implants made of glass-ceramic containing apatite and wollastonite were used for reconstruction of large bone defects of the weight-bearing acetabulum in canine total hip arthroplasties. 24 dogs underwent replacements and were killed after 3, 6, and 12 months. The interface between the prosthesis and bone was examined radiographically, histologically, and mechanically. Bone bonding with the prosthesis occurred in all the implants. Glass ceramic containing apatite and wollastonite implants seem promising for use in total hip arthroplasty as filling materials for large defects in weight-bearing bone.

Acetabulum↗
PubMed1993

Cementless total hip replacement. Bio-active glass ceramic coating studied in dogs.

We studied 2 types of a cementless total hip prosthesis in dogs. Both were coated with titanium plasma-spray. In both components, the pores in the deep layer of 1 group were further coated with apatite and wollastonite containing glass-ceramic (AW glass-ceramic). 50 dogs underwent unilateral total hip replacements, and were killed at 1, 3, or 6 months postoperatively. We evaluated the femoral and the acetabular components mechanically and histologically. At 1 month, the detaching load and bone ingrowth of the AW glass-ceramic-coated femoral and acetabular components were higher than those of the control implants. At 3 and 6 months there were no differences between the 2 types of components. Thus, AW glass-ceramic enhanced the early phase of cementless implant fixation.

Animals↗
PubMed1993

[Age-dependent changes in the square drawing test].

The square drawing test (SDT) is vertical writing test, conducted to evaluate equilibrium, done with the subject blindfolded. We investigated the development of equilibrium and presbyastasis by using SDT. Fifty three children underwent SDT every year for nine years (5-14 years old). Sixty six healthy elderly subjects (65-88 years old) were also examined. Control results were obtained from 117 young adults (22-33 years old). Four parameters of SDT (the total of each length, the whole length, the deviation angle and the start-end distance) were calculated with an SDT-computer and subjected to statistical analysis. Through the seventh grade, at least one of the parameters of SDT was statistically different from that in young adults. These differences were not observed in eighth grade children. Most parameters of SDT in elderly subjects were statistically different from those of control subjects. These results suggest that the equilibrium function matures at approximately 14 years of age and is commonly impaired after 65 years of age.

Adolescent↗
PubMed1993

AS-183, a novel inhibitor of acyl-CoA: cholesterol acyltransferase produced by Scedosporium sp. SPC-15549.

A novel compound, AS-183, which inhibits acyl-CoA: cholesterol acyltransferase (ACAT), was isolated from the culture broth of a fungus, Scedosporium sp. SPC-15549. AS-183 inhibited ACAT activity in an enzyme assay system using rabbit liver microsomes with an IC50 value of 0.94 microM. AS-183 also inhibited cholesterol ester formation in HepG2, CaCo2, and THP-1 cells with IC50 values of 18.1, 25.5, and 34.5 microM, respectively.

Animals↗
PubMed1993

MS-347a, a new inhibitor of myosin light chain kinase from Aspergillus sp. KY52178.

MS-347a was isolated from the culture broths of Aspergillus sp. KY52178 as an inhibitor of smooth muscle myosin light chain kinase (MLCK). MS-347a inhibited the activity of chicken gizzard MLCK with an IC50 value of 9.2 microM. The inhibition was dependent on time of preincubation of MS-347a with the enzyme, suggesting irreversible inhibition. It is likely that the inhibitor binds to the catalytic domain of MLCK, since the compound inhibited not only calmodulin-dependent but also calmodulin-independent activity of MLCK. Calmodulin-dependent cyclic nucleotide phosphodiesterase, cAMP-dependent protein kinase and cGMP-dependent protein kinase were not inhibited by 150 microM MS-347a at all, although the compound inhibited protein kinase C with an IC50 value of 16 microM. MS-347b, a minor component was also isolated from the same culture broths. This minor component at 150 microM did not inhibit the activity of MLCK.

Aspergillus↗
PubMed1993

Cardiovascular effects of YM-16151-4: a novel calcium entry blocking and selective beta 1-adrenoceptor blocking agent in rats and dogs.

The cardiovascular effects of YM-16151-4 were evaluated in rats and dogs. In conscious rats, YM-16151-4 (3-30 mg/kg p.o.) produced a dose-dependent hypotensive effect without increasing heart rate (HR) and plasma renin activity (PRA). Nifedipine (3-10 mg/kg p.o.) produced a dose-dependent hypotensive effect but significantly increased HR and PRA. Atenolol (30 mg/kg p.o.) decreased PRA but did not decrease blood pressure and HR. The cardiovascular effects of the combination of nifedipine and atenolol were similar to those of YM-16151-4. It is interesting that the time course of the hypotensive effect of YM-16151-4 was similar to that of its beta 1-adrenoceptor blocking effect, although the time courses of these effects of the combination of nifedipine and atenolol were different. In conscious dogs, YM-16151-4 (0.3-10 mg/kg p.o.) also produced a long-lasting hypotensive effect with almost no effect on HR and PQ-interval. The time course of the beta 1-adrenoceptor blocking effect was similar to that of its hypotensive effect. Furthermore, during 10-day repeated oral administration, neither tolerance nor augmentation was observed in the hypotensive and beta 1-adrenoceptor-blocking effects. In conclusion, the present results indicate that YM-16151-4 is an effective and long-lasting hypotensive agent that does not increase HR and PRA. These effects of YM-16151-4 may be attributable to its calcium-entry-blocking and beta 1-adrenoceptor-blocking activities, and the ratio of two activities was constant after single and repeated oral administrations.

Adrenergic beta-1 Receptor Antagonists↗
PubMed1993

Two forms of acidic arginine amidases in human kidney.

Two forms of acidic arginine amidases were separated from human kidney extract using the techniques of basic ion exchange adsorption and elution as well as lima bean trypsin inhibitor (LBTI) and aprotinin affinity adsorptions and elutions. The enzymes were tentatively named acidic human renal arginine amidase-L (AHRAA-L, with affinity to an LBTI column) and -A (AHRAA-A, with affinity to an aprotinin column). Both enzymes showed a similar molecular mass of approximately 3.0 x 10(4) daltons, differing from that of human renal kallikrein (HRK, molecular mass of 4.8 x 10(4) daltons). The specific activity of AHRAA-L and -A were 106 and 680 nmol/min/A280 of Val-Leu-Arg-pNA amidolysis, respectively, and they were strongly inhibited by LBTI and human urinary trypsin inhibitor (UTI), while ethylenglycol-bis(beta-amino ethylether)-N,N,N',N'-tetraacetic acid (EGTA) showed a weak or no effect on both enzymes.

Esterases↗
PubMed1993

A novel skeletal drug delivery system using self-setting bioactive glass bone cement. IV: Cephalexin release from cement containing polymer-coated bulk powder.

A novel device consisting of Eudragit-coated cephalexin as a model drug and a self-setting bioactive cement based upon CaO-SiO2-P2O5 glass was investigated. The glass cement hardened within 5 min of mixing with a phosphate buffer. After setting, in vitro drug release from homogeneous or heterogeneous drug-loaded cement pellets in a simulated body fluid (SBF) at pH 7.25 and 37 degrees C continued for over 2 weeks. The hardened cement gradually formed low-crystallinity hydroxyapatite and decreased in volume by about 5% during drug release in SBF. Consequently, 30% of the loaded drug was initially released from the homogeneous cement system, and thereafter it was released more slowly. Since the heterogeneous system consisting of the cement and a 50% polymer coated, drug-loaded pellet avoided this drug's burst, the drug was released over a longer period than that in the homogeneous system. The heterogeneous system released the polymer-coated drug very slowly, because it completely avoided the initial burst, and sustained the release over a long period.

Biocompatible Materials↗
PubMed1993

Role of ethanol-inducible cytochrome P-450 2E1 in the development of hepatocellular carcinoma by the chemical carcinogen, N-nitrosodimethylamine.

Cytochrome P-450 2E1 is a specific isozyme of cytochrome P-450 induced by ethanol. P-450 2E1 may also be the only enzyme that metabolizes N-nitrosodimethylamine at a very low concentration. Because N-nitrosodimethylamine is a procarcinogen, the possibility that induction of P-450 2E1 by alcohol abuse may accelerate the carcinogenic action of a very small dose of N-nitrosodimethylamine should be considered. To investigate this possibility, effects of ethanol on the hepatic carcinogenic action of a very small dose of N-nitrosodimethylamine were analyzed in rats. Sixty Wistar male rats were divided into two groups (ethanol and control) according to the liquid diets they were fed. After preliminary feeding, N-nitrosodimethylamine in two concentrations (1.5 ng/ml and 3.0 micrograms/ml) in drinking water was given with the diets for 40 or 60 wk. To avoid metabolic competition between ethanol and n-nitrosodimethylamine, we gave N-nitrosodimethylamine and the diets alternately. The average amount of N-nitrosodimethylamine consumed per day was 11 to 37 ng/kg body weight in the 1.5-ng group and was 27 to 37 micrograms/kg body weight in the 3.0-microgram group. Hepatic P-450 2E1 content was six times higher in the ethanol-treated groups than in the control groups throughout the experiment. Visible nodules and enzyme-altered foci were not found in rats in any group at the end of the fortieth week. These preneoplastic changes were found at the end of the sixtieth week only in rats in the groups treated with both ethanol and N-nitrosodimethylamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[The efficacy of prophylactic antibiotic and tocolytic therapy for premature rupture of the membranes--a prospective randomized study].

A comparative study in patients with premature rupture of the membranes (PROM) from 25 to 34 weeks of gestation was carried out, prospectively. Group 1 (34 patients) was given aggressively intrauterine therapy including the administration of tocolytic agents (ritodrine and/or magnesium sulfate) and prophylactic antibiotics (AB-PC 2g/day). Group 2 (41 patients) was managed conservatively with bed rest only. At the time of admission to the study, there were no clinical signs of infection, fetal distress, or active labor in either group. All patients were delivered if the pregnancy had reached 35 weeks of gestation or later, had established labor, or developed evidence of chorioamnionitis or fetal distress. Prolongation for more than 72 hours was greater in group 1 than in group 2. There was no difference in the incidence of chorioamnionitis, postpartum endometritis, or placental infection in the groups. However, the incidence of a low Apgar score (7 < at 5 min), requiring artificial ventilation, and infection was more common in group 1. It is concluded that the use of antibiotics and tocolytics might make the management of PROM more complicated.

Anti-Bacterial Agents↗
PubMed1993

High density lipoprotein and low density lipoprotein attenuate the inhibitory effects of oxidized low density lipoprotein on endothelium-dependent arterial relaxation.

We have recently reported that oxidized low density lipoprotein (ox-LDL) inhibits endothelium-dependent arterial relaxation through its increased lysophosphatidylcholine (LPC). In this study we examined whether high density lipoprotein (HDL) as well as native low density lipoprotein have any effects on the inhibition of endothelium-dependent relaxation by ox-LDL in isolated strips of rabbit thoracic aorta. Both LDL and HDL were isolated from normal human plasma and LDL was oxidized by exposure to copper. Preincubation of arterial strips with ox-LDL (0.1-0.5 mg protein/ml) inhibited endothelium-dependent relaxation to acetylcholine (ACh) in a concentration-dependent manner. HDL (1 mg protein/ml) by itself had no effect on the relaxation to ACh. In the presence of HDL, the inhibition by ox-LDL was markedly reduced. In addition, native LDL also attenuated the inhibition of endothelium-dependent relaxation by ox-LDL. Thus, HDL and native LDL may have salutary effects against the impairment of endothelium-mediated vasodilation in atherosclerotic arteries.

Acetylcholine↗