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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 559 records · Page 31Linked to original sources
PubMed1992

Effects of a nonpeptide vasopressin antagonist (OPC-21268) on cytosolic Ca2+ concentration in vascular and cardiac myocytes.

A selective V1 antagonist, 1-(1-[4(3-acetylaminopropoxy)benzoyl]-4-piperidyl)-3,4-dihydro-2(1 H)- quinolinone (OPC-21268), which is nonpeptide and orally effective, has been recently synthesized. We studied the effects of vasopressin and OPC-21268 on cell contraction with a video motion detector and cytosolic Ca2+ concentration ([Ca2+]i) by using indo-1 in cultured rat vascular smooth muscle cells and cultured chick embryo ventricular myocytes. Exposure of cultured vascular smooth muscle cells to vasopressin (1-100 nM) dose-dependently produced an initial transient increase (from control level [Ca2+]i of 133.6 +/- 10.9 nM to peak [Ca2+]i of 842.7 +/- 172.8 nM at 100 nM vasopressin, p less than 0.01) and then a small sustained increase in [Ca2+]i. After pretreatment of vascular smooth muscle cells with 1 microM OPC-21268, the effects of 100 nM vasopressin on [Ca2+]i were abolished. Exposure of ventricular myocytes to 100 nM vasopressin slightly but significantly decreased peak systolic cell position (-8.7 +/- 3.7%, p less than 0.05) and also produced reductions in peak systolic [Ca2+]i (from 962.2 +/- 76.4 to 751.2 +/- 70.5 nM, p less than 0.01) within 30 seconds. Pretreatment of ventricular myocytes with OPC-21268 (1 microM) completely suppressed vasopressin-induced changes in peak systolic cell position and [Ca2+]i. These results suggest that vasopressin may increase vascular tone and may also cause a direct negative inotropic effect via V1 receptors and that this orally active V1 antagonist (OPC-21268) may have potential clinical usefulness.

Animals↗
PubMed1992

Detection of coronary artery calcification by X-ray computed tomography and its significance: a new CT scoring technique.

In order to study the utility of X-ray computed tomography (CT) for the evaluation of coronary stenosis, the authors developed a scoring system for calcification seen through CT and compared the results with coronary angiographic (CAG) findings (Friesinger's scoring system). Their study included 143 patients (angina pectoris 53, myocardial infarction 44, control 46) who received both CT and CAG. Judkins method was selected for CAG, and stenosis greater than or equal to 75% was defined as significant. Horizontal slices of CT from ascending aorta to cardiac apex at 1 cm intervals were imaged without contrast enhancement. CT scoring system was as follows: no calcification = 0, the length of calcification less than 1 cm = 1, 1-2 cm = 2, more than 2 cm = 3 points. They then totaled the separate scores of all the slices for each coronary artery. Sensitivity, specificity, and predictive value of CT against coronary stenosis were good (79%, 80%, 69%, respectively). The correlation between CT and CAG scores was significant (r = 0.644, p less than 0.01). For all coronary arteries, no correlation was found between the CAG and CT findings for patients less than forty-five years of age. However, from 45 years of age upward, the results were significant. Until now, to the best of their knowledge, no satisfactory system to define the severity of coronary calcification has existed. Density cannot be used, because values are dependent on the area of the region of interest used. They demonstrated the considerable potential usefulness of CT in predicting the presence of coronary stenosis and analyzing its severity.

Calcinosis↗
PubMed1992

Role of left atrial booster pump function in a worsening course of congestive heart failure.

We evaluated changes in left ventricular (LV) preload and the Doppler-derived transmitral late to early diastolic peak velocity ratio (A/E ratio) during the exercise in 27 patients with ischemic heart disease. After the exercise, A/E ratio decreased in 16 patients with a remarkable elevation in LV preload, and increased in 11 with a mild elevation. Further, Doppler transmitral flow in conjunction with pulmonary venous flow and hemodynamic parameters were analyzed in 11 dogs during a worsening course of heart failure induced by dextran infusion. The relationship of A/E ratio to LV end-diastolic pressure showed a quadratic curve concave to the pressure axis. A/E ratio, an index expressing left atrial (LA) contribution to LV filling, returned to that seen before volume loading under the condition of cardiac dysfunction. Pulmonary venous reflux fraction determined as the ratio of peak velocity of pulmonary venous reflux during LA systole to the sum of systolic and diastolic peak velocities of pulmonary venous antegrade flow, did not increase here. In this situation, blood could not be ejected from the left atrium into the left ventricle and even into the pulmonary veins during LA contraction. Finally, LV filling was not compensated by the left atrium, and LA booster pump function itself was deteriorated.

Aged↗
PubMed1992

Effect of 50 kilobase-plasmid, pKDSC50, of Salmonella choleraesuis RF-1 strain on pig septicemia.

Salmonella choleraesuis strains with and without 50-kilobase plasmid (pKDSC50) were intravenously inoculated into Yorkshire pigs. By the inoculation of 7.2 x 10(5) - 3.5 x 10(7) cells, RF-1 strain with pKDSC50, but not 31N-1 strain without the plasmid, caused a septicemia. The inoculation of 8.7 x 10(9) RF-1 cells killed pigs at 2-4 day postinfection with severe hemorrhage on the whole body. Pigs with a similar number of 31N-1 cells (8.3 x 10(9) cells), showed milder hemorrhage, and they died at 6 day postinfection. These results indicated that pKDSC50 is required for RF-1 strain to express the full virulence causing a heavy cutaneous pig septicemia.

Animals↗
PubMed1992

Heterotopic intestinal membrane in a retroperitoneal tumor.

Plain abdominal X-rays of a 13-year-old girl with chief complaints of back pain revealed calcification in the upper left abdomen. A calcified tumor was confirmed at the dorsal side of the pancreatic tail upon admission. A completely formed colic membrane free of all other germ layers was discovered within the tumor, leading to a diagnosis of heterotopic colonic membrane. To our knowledge, there have been no other cases of heterotopic intestinal tissue of this type, so we consider this an extremely rare case worth reporting.

Adolescent↗
PubMed1992

Effect of splanchnic nerve stimulation on epinephrine and norepinephrine release from gastrointestinal sympathetic postganglionic endings in the frog.

Gastrointestinal vascular perfusates in bullfrogs before and after splanchnic nerve stimulation were collected and analyzed for epinephrine and norepinephrine. Catecholamine in the perfusate before stimulation was predominantly epinephrine. Upon stimulation a marked increase in epinephrine release without any significant change in norepinephrine release was observed in experiments at 8-10 degrees C as well as 16-21 degrees C, showing that in frogs epinephrine is the sympathetic neurotransmitter and that the release of epinephrine is not affected by low temperatures.

Animals↗
PubMed1992

Epinephrine and norepinephrine release from bullfrog gastrointestinal sympathetic postganglionic endings at a high ambient temperature.

The influence of a high ambient temperature on sympathetic neurotransmitter release in bullfrogs was studied. Gastrointestinal vascular perfusates were collected before and after splanchnic nerve stimulation, and their content of epinephrine and norepinephrine was determined. A marked increase in epinephrine and norepinephrine release was observed following stimulation at 29-32 degrees C, indicating that epinephrine and norepinephrine may both act as adrenergic transmitters in a high-temperature environment.

Animals↗
PubMed1992

Inhibitory effects of organotin compounds on histamine release from rat serosal mast cells.

Tributyltin inhibited compound 48/80-induced histamine release from rat serosal mast cells in a dose-related manner. Triphenyltin and tripropyltin also showed a strong inhibitory effect on the histamine release and the degree of the inhibition was the same as that of tributyltin. The inhibitory effects of other organometals were much smaller than those of the organotins. Tributyltin and triphenyltin also showed a tendency to inhibit histamine release induced by concanavalin A + phosphatidylserine and calcium ionophore A 23187. The present results suggest that certain triorganotin compounds may have a specific inhibitory effect on histamine release by acting on the same process in each of the three stimulus responses.

Animals↗
PubMed1992

[Effects of self-efficacy and outcome expectation on observational learning of altruistic behavior].

The purpose of the present study was to examined the hypothesis that the effects of observational learning of altruistic behavior are related to personal viewpoint, self-efficacy, outcome expectation, and other factors. One hundred and fifty-five fourth-grade school children were assigned randomly to four conditions; distress viewpoint, outcome expectation, altruistic behavior, or non-observational control. After observational learning, the students were immediately administered the generalization test of altruistic behavior, empathy, reward and punishment expectations, and rating tests of self-efficacy belief. It was found that; (a) altruistic behavior and outcome expectation conditions had significant learning effects, (b) self-efficacy was able to predict altruistic response in the altruistic behavior viewpoint condition, and (c) from an outcome expectation viewpoint, altruistic behavior toward peers and adults related to punishment expectation, whereas social sharing was related to reward expectation. According to these findings, an observational learning model of altruistic behavior was proposed.

Altruism↗
PubMed1992

Possible mechanisms of gastroduodenal mucosal damage in volunteers treated with nonsteroidal antiinflammatory drugs--the usefulness of prodrugs.

A controlled double blind study on the incidence of nonsteroidal antiinflammatory drug (NSAID) gastropathy was performed in 29 healthy volunteers administered diclofenac Na (10 subjects) or a prodrug (loxoprofen Na in 10 subjects and proglumetacin maleate in 9 subjects). The incidence of NSAID gastropathy was significantly lower in the subjects administered the prodrugs than in those administered diclofenac Na (p less than 0.05), which suggested the clinical usefulness of the prodrugs.

Adult↗
PubMed1992

[Effects of exercise and calcium-intake on bone hardness and bone constituents in aged mice].

Effects of exercise and differing calcium intakes on bone hardness and bone constituents were examined using mice (40 weeks old) in successive stages of senescence to contribute to our understanding of preventive measures against osteoporosis. In the present study, the mice were divided into four groups, combinations of stock diet (Ca: 1.25 g/100 g) or low Ca diet (Ca: 0.15 g/100 g), with or without physical exercise (forced exercise, 40 min/day at a velocity of 12 m/min) and maintained in their respective conditions for 16 weeks. Autopsies were performed or representative mice every four weeks (44, 48, 52, 56 weeks old). The obtained results are summarized as follows: 1) In female mice highest values for femoral bone weight were observed after 48 weeks in the mice exposed to forced exercise and on a stock diet and had a significant difference from the other groups. No difference was observed in male mice. 2) Bone hardness had a tendency to be reduced with age in all groups. The velocity of diminution was small in the mice kept on stock diet as compared to those on a low Ca diet. The highest bone hardness was observed in the mice kept in forced exercise and stock diet group at every stage. 3) Bone constituents, Ca, P and hydroxyproline, showed no differences in concentration per weight of bone. But higher total content in the femur was obtained in the mice kept on a stock diet. 4) No differences in concentration of serum calcitonin and parathormone were seen in every group of male mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Isolation and sequence of rat testis cDNA for a calcium binding polypeptide similar to the regulatory subunit of calcineurin.

We have cloned and sequenced rat testis cDNAs coding for a calcium binding polypeptide similar to calcineurin beta subunit, the Ca(2+)-binding subunit of the Ca2+/calmodulin stimulated protein phosphatase. Rat testis cDNA library was screened with a monoclonal antibody Va1 raised against bovine brain calcineurin beta subunit. The deduced amino acid sequence is similar to that of human brain calcineurin beta subunit with respect to containing four putative calcium binding sites. However, distinct differences were found: 1) The cloned cDNA had six amino acids polypeptide tail at carboxy-terminal which is absent in human brain calcineurin beta subunit. This amino acids tail makes the carboxy-terminal highly hydrophilic in contrast to the human brain beta subunit which is hydrophobic at carboxy-terminal; 2) eleven amino acids at the N terminal of the cloned cDNA were completely different from the corresponding region of the brain calcineurin beta subunit.

Amino Acid Sequence↗
PubMed1991

Comparison of sulphur-mode and tin-mode flame photometric detectors for the gas chromatographic determination of organotin compounds.

A comparison of sulphur-mode (393 nm) and tin-mode (610 nm) flame photometric detectors for the gas chromatographic determination of butyl- and phenyltin compounds is described. The chromatographic peaks of the butyl- and phenyltin compounds were well separated, and high sensitivity was achieved in both modes; however, the tin-mode was more specific for tin compounds than the sulphur-mode. The absolute detection limits with the sulphur-mode and the tin-mode were 3.9-7.6 pg and 2.6-5.1 pg as tin, respectively. The application of the tin-mode gas chromatographic method to the determination of organotin compounds in fish is presented. For this application, organotins are extracted (as chloride) with hydrochloric acid and n-hexane-benzene (3:2, containing 0.05% tropolone) and the extracts are pentylated by a Grignard reagent prior to gas chromatography. The absolute recoveries of butyl- and phenyltin compounds added to fish samples ranged from 68.5 to 84.4% (the coefficients of variation were less than 6.6% for all substances, n = 8). Significant amounts of three organotin compounds (di- and tributyltin and triphenyltin) in fish samples were detected by this method. This technique may have application for other organotin compounds and the monitoring of butyl- and phenyltin compounds in the environment.

Animals↗
PubMed1991

Purification and characterization of three forms of differently glycosylated recombinant human granulocyte-macrophage colony-stimulating factor.

We have purified recombinant human granulocyte-macrophage colony-stimulating factor (hGM-CSF) produced in human lymphoblastoid Namalwa cells. From the results of tunicamycin treatment and N-glycosidase F digestion, it was demonstrated that Namalwa-derived hGM-CSF was highly glycosylated at two potential N-glycosylation sites and several O-glycosylation sites as previously shown for naturally occurring hGM-CSF. We classified the hGM-CSF molecules into three groups according to the molecular weight corresponding to the degree of N-glycosylation: the molecules with two N-glycosylation sites occupied (designated 2N), the molecules with either site glycosylated (1N), and the molecules lacking N-glycosylation (0N). Despite such varied degrees of N-glycosylation, almost all molecules were O-glycosylated. To investigate the role of carbohydrate moieties of hGM-CSF, we isolated each form of hGM-CSF and examined its biological properties. The 2N-type showed 200-fold less in vitro specific activity compared with unglycosylated Escherichia coli-derived hGM-CSF, although the activity of the 0N-type was equivalent to that of the E. coli-derived material. The 1N-type showed an intermediate level of activity. However, in terms of clearance from blood circulation in the rat, the 2N-type showed a half-life five times longer than that of the 0N-type and E. coli-derived hGM-CSF. From these findings, we concluded that N-linked carbohydrate moieties of hGM-CSF play conflicting physiological roles in the efficacy of the protein in vivo but that O-linked carbohydrate moieties do not have such effects.

Animals↗
PubMed1991

Histochemical and ultrastructural observations on brown degeneration of human intervertebral disc.

Thirty-eight fresh human intervertebral discs collected during anterior interbody fusion surgery were histochemically and ultrastructurally analyzed for pigments. Macroscopically, five stages of degeneration were classified according to the color, fibrosis, and fragility of the nucleus pulposus of the discs. In order to demonstrate lipofuscin granules, specimens were subjected to special staining procedures, including carbol fuchsin lipofuscin stain, the Schmorl's reaction, and autofluorescence. Lipofuscin granules were distributed from the inner layer of the annulus fibrosus to the nucleus pulposus. Such granules were numerous in cases of slight or severe degeneration, whereas fewer granules were found in cases of moderate degeneration. However, the stage of macroscopic degeneration of the intervertebral disc did not necessarily correlate with the incidence of lipofuscin granules. By ultrastructural observation, the morphological features of the components of the intervertebral disc and the ultrastructure of the lipofuscin granule were clarified. The ultrastructure of the "brown degeneration" disc exhibited markedly increased amorphous electron-dense bodies located among collagen fibrils in the matrix.

Adult↗