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Biomedical subjects

Y Nishikawa

Publications and source records attributed to Y Nishikawa.

At least 235 records · Page 13Linked to original sources
PubMed1989

The relationship between connective tissue and its microvasculature in the healthy dog gingiva.

The morphological consistency of subepithelial connective tissue and its vascular architecture was studied in the healthy gingiva of adult mongrel dogs. Corrosion-cast specimens of the vasculature and specimens of well-separated connective tissue from the lamina propria were observed by SEM. Specimens injected with india ink also were examined employing light microscopy. Summarizing the results: 1) Beneath the buccal gingival epithelium, short conical papillae were seen in the subepithelial connective tissue. The capillary structure throughout this region was basically of the loop type, the overall appearance of which replicated the papillae. The papilla disappeared at the muco-gingival junction, so that after the transition to the alveolar mucosa, no papillary formation was observed. The vasculature had transformed from loop to network structure. 2) Beneath the sulcular gingival epithelium, the subepithelial connective tissue displayed a smooth concavity with no papillae. In this region, the capillaries formed a flat, dense network in accordance with the morphology of the connective tissue. The capillary network suddenly disappeared at the terminal edge of the inner epithelium. The vessels of the lamina propria located immediately beneath the network reduced their lumina at the margin and formed the plexus of the periodontium, displaying a rather open network.

Acrylic Resins↗
PubMed1989

Long-term coenzyme Q10 therapy for a mitochondrial encephalomyopathy with cytochrome c oxidase deficiency: a 31P NMR study.

For 2 years we administered high doses of coenzyme Q10 (CoQ) to a patient having mitochondrial encephalomyopathy with cytochrome c oxidase deficiency. Abnormal elevation of the serum lactate per pyruvate ratio and the increased concentration of serum lactate plus pyruvate induced by exercise decreased with CoQ treatment. This therapeutic effect continued for 2 years. 31P nuclear magnetic resonance spectroscopy showed acceleration of the postexercise recovery of the ratio of phosphocreatine to inorganic phosphate in muscle during CoQ treatment. These observations support the beneficial effect of CoQ on the impaired mitochondrial oxidative metabolism in muscle. Also, impaired central and peripheral nerve conductivities consistently improved during CoQ treatment. These results indicate that CoQ has clinical value in the long-term management of patients with mitochondrial encephalomyopathies, even though there are clinical limitations to the effects of this therapy.

Adult↗
PubMed1989

Acrylamide derivatives as antiallergic agents. I. Synthesis and structure-activity relationships of N-[(4-substituted 1-piperazinyl)alkyl]-3-(aryl and heteroaryl)acrylamides.

A new series of acrylamide derivatives (7-10) were synthesized. Antiallergic activity of these compounds was evaluated and their structure-activity relationships were examined. Compound 10d, N-[4-(4-diphenylmethyl-1-piperazinyl)butyl]-3-(3-pyridyl)acrylamid e, showed antiallergic activity equivalent or superior to that of ketotifen in the rat passive cutaneous anaphylaxis (PCA) test by oral administration. Compound 10d, unlike ketotifen, had more potent in vitro 5-lipoxygenase inhibitory activity than caffeic acid, whereas its in vitro antihistamine activity was weaker than that of ketotifen. In addition, its inhibitory activity against histamine release from rat mast cells was approximately two-thirds as potent as that of disodium cromoglycate (DSCG). Compound 10d is a promising agent for treating a variety of allergic diseases.

Acrylamides↗
PubMed1989

Synthesis and antiallergic activity of N-[4-(4-diphenylmethyl-1-piperazinyl)butyl]-1,4-dihydro-4-oxopyridine-3 - carboxamides.

A new series of oxopyridinecarboxamide derivatives 3a--g and 5a were synthesized and evaluated for their antiallergic activity. 1,4-Dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxamides 3a and 5a exhibited potent antiallergic activity (inhibitory rates of 80.7 and 88.3%, respectively, at 20 mg/kg, p.o.) in the rat passive cutaneous anaphylaxis (PCA) test and also exhibited much more potent in vitro inhibitory activity than caffeic acid against the enzyme 5-lipoxygenase (5-LO). Their in vitro antihistamine activity, however, was weaker than that of ketotifen. Compounds 3a and 5a are viewed as promising candidates for antiallergic agents.

Animals↗
PubMed1989

Acrylamide derivatives as antiallergic agents. III. Synthesis and structure-activity relationships of N-[4-(4-diphenylmethyl-1-piperazinyl)butyl]- and N-[4-(4-diphenylmethylene-1-piperidyl)butyl]-3-heteroarylacry lamides.

A new series of 3-heteroarylacrylamides 2 and 4 was prepared and the inhibitory activities against the rat passive cutaneous anaphylaxis (PCA) reaction and the enzyme 5-lipoxygenase (5-LO) were tested. Most of the compounds exhibited an anti-PCA activity superior to or equivalent to ketotifen and had a 5-LO inhibitory activity. The 3-heteroarylacrylamide derivatives including 3-(3-pyridyl)acrylamides represent a new structural class of compound that exhibits not only an in vivo anti-PCA activity but also an in vitro 5-LO inhibitory activity.

Acrylamides↗
PubMed1989

[Effects of grayanotoxin III on liver function and renal function in rats].

The grayanotoxin III (GTX III) was given intraperitoneally to rats at a dose of 0.8 or 2.8 mg/kg. To study the effects of GTX III on rats, biological tests in serum for functions of liver and kidney and their pathological observation were performed 1 h after the administration. Using analysis of variance, multiple comparison and correlation on biological parameters, activities of glutamic-pyruvic transaminase (GPT), guanase and leucine aminopeptidase and concentrations of total protein, albumin, creatinine, uric acid and K increased significantly. These parameters showed dose-effect relations with GTX III. Though GPT and free fatty acid increased significantly, dose-effect relations were not shown. The activity of choline esterase and the concentrations of bilirubin, urea-N, lipoperoxide, cholesterol, triglycerides, Na and Cl were not significantly different. Pathological changes were not observed in the liver and kidney of rats. These results show that GTX III may affect the functions of liver and kidney in rats.

Alanine Transaminase↗
PubMed1989

[Reduction of urinary oxalate excretion by administration of calcium and citrate].

Oxalic acid seems to be more important for the formation of calcium oxalate stone than calcium. Three grams of calcium lactate and 3 g of uraly U were administered to 35 urolithiasis patients, whose stones were mainly composed of calcium oxalate. Urinary oxalate level was reduced significantly without raising urinary calcium level by the administration of the two drugs for two weeks. The reduction of oxalic acid was particularly remarkable in patients without hypercalciuria. The mechanism of action of these drugs and the relation to dietary management were discussed.

Adult↗
PubMed1989

[Measurement of coronary flow velocity with Doppler catheter: evaluation of coronary flow reserve in successful angioplasty].

To assess the therapeutic effect of percutaneous transluminal coronary angioplasty (PTCA) on coronary flow reserve, coronary flow velocity (CFV) was measured with a Doppler catheter before and immediately after PTCA in 11 patients, who underwent elective PTCA for critical stenosis in proximal or mid portion of the left anterior descending artery (LAD). A Doppler catheter was positioned at the proximal portion of the LAD and the CFV was measured at rest and after intracoronary injection of 6 ml of contrast material (Iopamidol), 6 ml of saline or 3 mg of Isosorbide Dinitrate (ISDN). Peak to resting velocity ratio (PRVR) was calculated as an estimate of coronary flow reserve. Percent diameter stenosis (%S) was measured from cineangiogram. A translesional pressure gradient was obtained with an angioplasty catheter. These parameters measured in PTCA candidates were compared with those in 11 patients whose LAD had no critical stenosis. After PTCA, %S was decreased (94.2 +/- 1.4 vs 34.1 +/- 5.1%; mean +/- SEM). Pressure gradient was also decreased (59.5 +/- 4.9 vs. 25.1 +/- 3.3 mmHg). There was no difference between mean CFV at rest in patients before PTCA and that in patients without stenosis (4.52 +/- 0.63 vs. 5.46 +/- 0.61 cm/sec). By successful PTCA, CFV at rest was increased (7.39 +/- 1.32, p less than 0.05 vs. before PTCA). PRVRs in patients before PTCA were smaller than those in patients without stenosis (1.5 +/- 0.1, 1.4 +/- 0.1, 1.6 +/- 0.2 vs. 2.8 +/- 0.1, 2.5 +/- 0.2, 2.8 +/- 0.2, p less than 0.01; by contrast material, saline, ISDN, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Surgical repair of scimitar syndrome by direct anastomosis between right pulmonary vein and left atrium].

A surgical case of 8-year-old boy with scimitar syndrome is presented. The patient was admitted to the hospital because of exertional dyspnea and underdevelopment. Cardiac catheterization revealed a large amount of left to right shunt and O2 step up at the level of the inferior vena cava below the diaphragm. Angiography showed that the pulmonary vein draining the right lower lobe pierced the diaphragm and emptied into IVC. At operation the right pleural cavity was entered and a large anomalous pulmonary vein trunk was found which headed downward and medially and eventually entered in the diaphragm. A direct anastomosis between the scimitar vein and left atrium was made. To avoid kinking or stenosis of this vein, the parenchyma of the right lung (S7) was divided to create a passway of the vein. Anastomosis was performed without excessive tension or kinking on it. We conclude that the method applied in this case might be a procedure of choice for the repair of scimitar syndrome especially when there is no associating atrial septal defect or scimitar vein drains into IVC at the level lower than hepatic vein.

Anastomosis, Surgical↗
PubMed1989

[Activity of guanase in serum and liver function tests in HBe antigen-positive chronic hepatitis].

Forty-one patients with chronic hepatitis were divided into an HBe antigen-positive group (n = 13) and an HBe antigen-negative group (n = 28) to clarify the relationship between the presence of HBe antigen and liver function. In the HBe antigen-positive group, the activities of serum alanine aminotransferase (p less than 0.01), aspartate aminotransferase (p less than 0.05) and guanase (p less than 0.01) were significantly higher than those in the HBe antigen-negative group. The correlation coefficient between the HBe antigen titer and guanase activity was 0.528, which was higher than the corresponding values for alanine aminotransferase and aspartate aminotransferase. The determination of guanase activity in serum may be useful for evaluating the clinical severity of HBe antigen-positive chronic hepatitis.

Adolescent↗
PubMed1989

Measurement of erythrocyte arginase activity and the effect of lead on the activity in vitro.

Measurement of arginase activity made by varying the arginine concentration and the reaction time clarified that the amount of urea formed by arginase peaked at the substrate concentration of 150 mmol/l, and increased linearly by 20 minutes. By using discs punched out from a dried blood filter paper prepared from identical human blood sample, the amount of formed urea showed linear increase up to 160 U/g.Hb. The coefficients of variation in ten measurements were 6.1% for the mean activity of 46.2 U/g.Hb and 2.1% for 152.1 U/g.Hb. No decreases in arginase activity were observed when two different dried blood filter papers were left for one week at room temperature. Intact erythrocytes were treated with various concentrations of lead from 0 to 5 mumols/l and their arginase activities were measured. The activity did not elevate linearly with the rise of lead concentration, but an almost diphasic elevation was observed. The arginase activity of erythrocytes treated with 5 mumols/l of lead was higher than that for untreated ones by 32%.

Arginase↗
PubMed1989

The protective effects of calcium antagonist and free radical scavenger against myocardial ischemic/reperfusion injury in the isolated rat heart.

Using the isolated working rat heart model, efficacy of the calcium antagonist and free radical scavengers against the myocardial injury induced by ischemia and reperfusion was investigated. In the calcium antagonist series, diltiazem was added to St. Thomas' Hospital cardioplegic solution. After 35 minutes of ischemia (37C) and 30 minutes of reperfusion, the dose response curve of postischemic recovery of aortic flow showed the bell-shaped pattern and the addition of 0.4 mg/L of diltiazem significantly increased the final recovery of aortic flow from the control value of 45.3 +/- 3.1% to 59.1 +/- 3.7% (P less than 0.01). However, the higher dose of diltiazem reduced the postischemic recoveries of heart rate and aortic flow probably due to its side effects of negative inotropic and chronotropic effect. In the free radical scavengers series, 100 mg/L of superoxide dismutase (SOD) and 10 mg/L of catalase (CAT) were added in the same experimental schedule. The addition of these enzymes significantly improved the postischemic recovery of aortic flow, and the best recovery was seen in the group receiving both SOD and CAT (72.9 +/- 3.9%, P less than 0.001). It was suggested that SOD and CAT have potential clinical application in preventing oxygen radical-mediated myocardial injury in the setting of open heart surgery.

Animals↗
PubMed1989

[Successful simultaneous repair of tetralogy of Fallot and congenital tracheal stenosis in a 5-year old child].

Congenital cardiac anomaly combined with severe obstructive lesion of airway remains a surgical challenge. A case of 5-year old child with tetralogy of Fallot associated with congenital tracheal stenosis (cartilagenous ring) was reported. The patient had history of cyanosis and stridor since age 3 months and had been hospitalized repeatedly for recurrent respiratory distress. The diagnosis was first established and emergent Blalock-Taussig shunt was carried out during first admission at age 1 year and 7 months. On the fourth admission at age 5 year, a definitive surgical intervention was decided following re-evaluation of the patient by cardiac catheterization, bronchoscopy and bronchography. Trachea and heart were exposed through cervical collar and presternal skin incision and median sternotomy. Tracheal resection and end-to-end anastomosis combined with total correction of tetralogy of Fallot was carried out under cardiopulmonary bypass. Utmost care was paid to avoid contamination during the operation. He was extubated at 9th postoperative day and has been free from symptom 9 months after the operation.

Cardiopulmonary Bypass↗
PubMed1989

[Closure of patent ductus arteriosus in elderly cases].

A technique for closure of patent ductus arteriosus in the elderly cases is described. We have operated on eleven adult cases of patent ductus arteriosus cases in 10 years. In five cases cardiopulmonary bypass used and in the other six cases it was not used. The cardiopulmonary bypass was used especially for the patients with pulmonary hypertension (pulmonary artery mean pressure greater than 40 mmHg), or high aged (older than 40 years) patients. No operative death have occurred in both groups, and no complication from air embolism or hemorrhage have been encountered. The technique embodies the profound hypothermia, low flow, and direct suture of the pulmonary end of the ductus arterious through a pulmonary arteriotomy. The ductus has been obstructed by using a Hegar's dilator before core cooling was started. Hegar's dilator is useful for establishing profound hypothermia and satisfactory visualization of the operative field.

Adult↗
PubMed1988

Dual somatosensory representation of the periodontium in nucleus ventralis posteromedialis of the cat thalamus.

The distribution of periodontal units within the nucleus ventralis posteromedialis (VPM) was studied in urethane-chloralose-anesthetized cats. Recordings were made from a total of 63 periodontal units. Of these, 55 received contralateral input, the rest receiving ipsilateral input. The periodontal units receiving contralateral inputs were located in the medial part of the VPM proper, whereas those receiving ipsilateral inputs were found in the lateral subdivision of the nucleus ventralis posteromedialis parvocellularis (VPMpcl).

Action Potentials↗
PubMed1988

Ipsilateral somatosensory tongue representation within the lateral subdivision of the nucleus ventralis posteromedialis parvocellularis of the cat thalamus.

Neurons in the lateral subdivision of nucleus ventralis posteromedialis parvocellularis (VPMpcl) were studied in urethanchloralose anesthetized cats. The great majority of units responded to innocuous mechanical stimulation of the ipsilateral tongue, and the rest were responsive to innocuous mechanical stimulation of intraoral structures outside the tongue. No units responded to gustatory stimulation. These findings support the idea that VPMpcl receives ipsilateral trigeminal somatosensory input rather than gustatory input.

Animals↗
PubMed1988

Control of glycoprotein synthesis. Purification and characterization of rabbit liver UDP-N-acetylglucosamine:alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I.

UDP-N-acetylglucosamine:alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I catalyzes an essential first step in the conversion of high mannose to hybrid and complex N-glycans (Schachter, H. (1986) Biochem. Cell Biol. 64, 163-181; Oppenheimer, C.L., and Hill, R.L. (1981) J. Biol. Chem. 256, 799-804), i.e. the addition of GlcNAc to (Man alpha 1-6(Man alpha 1-3)Man alpha 1-6)(Man alpha 1-3)Man beta 1-4GlcNAc-OR to form (Man alpha 1-6(Man alpha 1-3)Man alpha 1-6)(GlcNAc beta 1-2Man alpha 1- 3)Man beta 1-4GlcNAc-OR. The enzyme has been purified from Triton X-100 extracts of rabbit liver by chromatography on CM-Sephadex, Affi-Gel blue, UDP-hexanolamine-Sepharose, and a novel adsorbent in which UDP-GlcNAc is linked to thiopropyl-Sepharose at the 5-position of uracil. The enzyme exists in crude liver extracts in two molecular weight forms separable on Sephadex G-200. The low molecular weight form was purified 64,000-fold with a specific activity of 19.8 mumol/min/mg. The pure enzyme was free of N-acetylglucosaminyltransferase II-V activities. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a single major band of Mr 45,000 and two minor bands of Mr 54,000 and 50,000. All three bands showed retarded elution from an affinity column in which the acceptor substrate for the transferase was covalently linked to Sepharose. Kinetic analysis indicated a largely ordered sequential mechanism with UDP-GlcNAc binding to the enzyme first and UDP leaving last. Studies with synthetic analogues of the substrate Man alpha 1-6(Man alpha 1-3)Man beta 1-4GlcNAc showed that an unsubstituted equatorial hydroxyl on carbon 4 of the beta-linked Man residue was essential for enzyme activity.

Animals↗