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Biomedical subjects

T Kawano

Publications and source records attributed to T Kawano.

At least 289 records · Page 16Linked to original sources
PubMed1992

[Myeloperoxidase activity as an indicator of leukocyte infiltration into the ischemic area in the middle cerebral artery occlusion model of the rats].

Myeloperoxidase was solubilized with hexadecyltrimethylammonium bromide and myeloperoxidase activity was measured with a dianisidine-H2O2 assay in the ischemic area after middle cerebral artery occlusion in rats. This enzyme could be measured 6 hours after the occlusion of the middle cerebral artery, then showed two peaks, one after 8 hours and another after 18 to 24 hours in 2 phase fashion as could be measured as far as 7 days, which was the termination of this experiments. These findings suggest that leukocyte infiltration into the ischemic area play an important role for the extension of the ischemic area. Further study should undertake whether leukocyte depletion decrease the ischemic area or not.

Animals↗
PubMed1992

[Therapeutic modality for esophago-gastric varices analyzed by endoscopic ultrasonography].

For 64 cases with portal hypertensive disease, we investigated the intramural and extramural structure of the stomach and esophagus by endoscopic ultrasonography (EUS). Variously developed intra- or extra-mural vascular structures had a relationship to the endoscopic variceal form, and the communicating (inflow) vessels to varices were found in 35 of 50 primary treated cases (70%). We classified the esophago-gastric varices into three types according to the vascular structure, such as the esophageal type, the esophago-gastric type and the solitary gastric type. From the analyses of these collateral structures, we should select a treatment as follows. In the esophageal type which has a few inflow vessels, it is easy to eliminate the varices by obturating the inflow vessels by endoscopic injection sclerotherapy (EIS). In the esophago-gastric type, which has many enlarged inflow vessels, the Hassab operation is effective to devascularize extramural inflow vessels, and the combination of EIS is necessary to sclerous the intramural varices. In the solitary gastric type which is a part of the downward porto-systemic shunt, Hassab operation is recommended to prevent the rupture of varices for the subtype with intramural running vessels, but conservative therapy is enough for the subtype without intramural running vessel.

Collateral Circulation↗
PubMed1992

[Effect of glycerol and mannitol on the distribution of brain tissue water determined by differential calorimetric scanning analysis].

To further clarify their mechanisms as "dehydrators", the effect of glycerol and mannitol on the distribution of tissue water was studied by using differential scanning calorimetry. In normal rat brain, glycerol, 30 minutes after infusion, reduced, by a certain amount, the free water contents. However, mannitol had no effect on the amount of tissue water. In the focal ischemic model, produced by Tamura's method, glycerol reduced the free water contents in the perifocal brain tissue. As for the contralateral brain tissue, mannitol not glycerol, reduced the total water contents. Above findings suggest that the effect of glycerol is mainly to decrease free water fraction in the non ischemic brain tissue, while mannitol shows its effect through the decrease it produces in the extra-brain water fraction.

Animals↗
PubMed1992

[Shotgun pellet embolus in the cerebral circulation via the internal carotid artery in the neck; a case report].

A 57-year-old hunter was shot accidentally and admitted to our hospital without any neurological deficits. Plain X-ray films of the neck revealed the presence of several shotgun pellets, one of which was thought to be in the vicinity of the right internal carotid artery at the C1 level. One week later, while surgical removal of pellets was being performed under fluoroscopic control, the pellet entered into the lumen of the artery and migrated to the intracranial vessels. Right carotid angiogram revealed that the pellet occluded in the right angular artery about 1.5cm distal from its outlet. Although embolectomy was performed, we could not get a patency of the vessel. CT scan taken 3 days after operation showed the occurrence of massive cerebral edema. Angiogram taken 2 weeks after confirmed occlusion of the vessel. The patient was discharged with left lower quadrantanopsia one month after the operation. In the literature, 20 similar cases have been hitherto reported and briefly reviewed. Of these 20, 6 cases died of cerebral infarction. We believe that embolectomy is warranted as soon as possible when patients show a condition building up to a stroke.

Carotid Artery, Internal↗
PubMed1991

Alcohol intake and nonfatal acute myocardial infarction in Japan.

The relation between alcohol and nonfatal acute myocardial infarction (AMI) was examined in a case-control study of 89 male patients and 271 control subjects in Fukuoka, Japan. Patients admitted for the first AMI at 2 hospitals in Fukuoka City were aged 40 to 69 years, and control subjects were recruited based on the telephone directory of the city. Information on alcohol drinking and potential coronary risk factors was obtained by using a self-administered questionnaire, and past drinkers were separated from lifelong abstainers in the analysis. After adjustment for age, occupation, cigarette smoking, strenuous exercise, body mass index, hypertension, diabetes mellitus and parental heart disease, the risk of AMI was progressively less with increasing levels of alcohol consumption. With those who never drank as a referent, adjusted odds ratios for current drinkers consuming less than 30, 30 to 59, and greater than or equal to 60 ml/day of alcohol were 1.11 (95% confidence interval 0.51 to 2.42), 0.31 (0.11 to 0.83), and 0.13 (0.05 to 0.36), respectively. These findings add to the body of data showing that alcohol drinkers are less likely to have AMI.

Adult↗
PubMed1991

[Effect of nizofenone on the symptomatic vasospasm after aneurysmal subarachnoid hemorrhage and its relationship to the levels of serum complements (CH50, C3 and C4)].

Serum complements (CH50, C3 and C4) after aneurysmal subarachnoid hemorrhage were measured in 42 patients over 2 to 3-week period. Nizofenone, an anti-vasospasmotic agent, was administered to 11 patients. In the nizofenone-treated group, 8 patients showed decreased serum C4 levels 5 days after the onset of subarachnoid hemorrhage, but among them, only 2 patients showed symptomatic vasospasm. Considering our previous data (majority of patients who showed decreased serum C4 levels presented with symptomatic vasospasm), these results suggest a favorable effect of nizofenone on the symptomatic vasospasm after aneurysmal subarachnoid hemorrhage.

Adult↗
PubMed1991

Endoscopic resection of early-stage esophageal cancer.

Early-stage esophageal cancerous lesions in four clinical cases were endoscopically resected via a newly developed procedure, endoscopic esophageal mucosal resection using a transparent tube (EMRT). In the complete resection of cancer-bearing mucosa, more than half of the circumferential mucosal resections did not involve major complications such as perforation or massive bleeding. Large ulcers artificially induced by this procedure disappeared within 3 weeks, exhibiting no stenotic changes. Resected specimens contributed well to microscopic examination for histological classification and determination of the depth of cancer invasion and possible vascular involvement. No signs of recurrence were observed during the 15-month follow-up period. We conclude that EMRT is a safe and minimally invasive local treatment for early-stage esophageal cancer that also provides specimens that are suitable for accurate histopathological diagnosis.

Adenocarcinoma↗
PubMed1991

N-linked sugar chains of mouse B16 melanoma cells and their low-metastasizing variant selected by wheat germ agglutinin.

The N-linked sugar chains of metastasizing mouse B16 melanoma cells (F1) and their wheat germ agglutinin-resistant variant (Wa4-b1) showing a dramatic decrease in metastasizing and tumorigenic potentials were liberated from their membrane glycoproteins by hydrazinolysis, and their structures were comparatively analysed. The results indicated that both cell lines contain high-mannose-type and bi-, tri- and tetraantennary complex-type oligosaccharides, and their ratios are similar. However, outer chain moieties of tri- and tetraantennary oligosaccharides of the variant are extensively fucosylated, resulting in the formation of X-antigenic determinants, Gal beta 1----4(Fuc alpha 1----3)GlcNAc. Oligosaccharides containing X-antigenic determinants amounted to 71% of the total complex-type oligosaccharides. Fucosylation occurs on every N-acetyllactosamine unit and the number of the determinants ranges from one to three in triantennary oligosaccharides and one to four in tetraantennary oligosaccharides. The determinants occur predominantly in non-sialylated forms, although some are in sialylated forms. Oligosaccharides containing non-sialylated X-antigenic determinants and those containing sialylated X-antigenic determinants are approximately in the ratio 6:1. Since no significant difference was found in the extent of branching of complex-type oligosaccharides of the two cell lines, it is suggested that non-fucosylated outer chains are important for the expression of metastasizing potential by the tumour cells.

Animals↗
PubMed1991

Reconstitution of CMP-N-acetylneuraminic acid hydroxylation activity using a mouse liver cytosol fraction and soluble cytochrome b5 purified from horse erythrocytes.

The hydroxylation of CMP-N-acetylneuraminic acid (CMP-NeuAc) in the formation of CMP-N-glycolylneuraminic acid requires several components which comprise an electron transport system. A protein, which replaces one of the components, was purified to homogeneity from a horse erythrocyte lysate. Based on its partial amino acid sequence and immunological cross-reactivity, this protein was identified as soluble cytochrome b5 lacking the membrane domain of microsomal cytochrome b5. The electron transport system involved in CMP-NeuAc hydroxylation was reconstituted, and then characterized using the purified horse soluble cytochrome b5 and a fraction from mouse liver cytosol. The hydroxylation reaction requires a reducing reagent, DTT being the most effective. Either NADH or NADPH was used as an electron donor, but the activity with NADPH amounted to about 74% of that with NADH. The hydroxylation was inhibited by salts and azide due to interruption of the electron transport from NAD(P)H to cytochrome b5 and in the terminal enzyme reaction, respectively.

Amino Acid Sequence↗
PubMed1991

Comparison of inhibitory actions of indomethacin and epostane on ovulation in rats.

Indomethacin, an inhibitor of cyclooxygenase that generates prostaglandins (PGs) from arachidonic acid, and 2 alpha,4 alpha,7-4,5-epoxy-17-hydroxy-4,17-dimethyl-3-oxoandrostane- 2-carbonitrile (epostane), an inhibitor of 3 beta-hydroxysteroid dehydrogenase that generates progesterone from pregnenolone, are both potent inhibitors of ovulation. This report compares the dose-dependent effects of these two inhibitors on ovarian levels of 5-, 12-, and 15-hydroxyeicosatetraenoic acid methyl ester (HETEs), prostaglandin E2 (PGE), prostaglandin F2 alpha (PGF), progesterone, 17 alpha-hydroxyprogesterone, 17 beta-estradiol, 4-androstene-3,17-dione, and testosterone during ovulation in 25-day-old immature Wistar rats. The ovulatory process was initiated by 10 IU of human chorionic gonadotropin (hCG). Indomethacin was given at 3 h after hCG in doses ranging from 0.0316 to 10.0 mg/rat. A dose of 0.1 mg/rat was the lowest dose to significantly reduce the ovulation rate from the control level of 70.5 +/- 5.8 ova/rat. This dose also reduced 15-HETE, but not 5-HETE, 12-HETE, or the steroids. PGE and PGF were strongly inhibited by an even lower dose of indomethacin (0.0316 mg/rat), but this dose did not affect the ovulation rate. Epostane was given at 3 h after hCG in doses ranging from 0.1 to 5.0 mg/rat. A dose of 1.0 mg/rat was the lowest dose to significantly inhibit ovulation. This dose also reduced the ovarian levels of 15-HETE and progesterone but not 5-HETE, 12-HETE, PGE, PGF, or the other steroids. The results indicate that the ovulation rate is most closely correlated to ovarian 15-HETE levels.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1991

Pituitary prolactinoma associated with polycystic ovary--case report.

A 25-year-old female presented with pituitary prolactinoma associated with polycystic ovarian disease and amenorrhea. After trans-sphenoidal adenomectomy, the serum prolactin level returned to normal. Postoperative ultrasonography revealed resolution of the polycystic ovary. Regular menses recommenced 2 months after surgery. Our experience suggests that pituitary prolactinoma may be a cause of polycystic ovarian disease.

Adult↗
PubMed1991

[The responses of somatosensory evoked potentials and cerebral blood flow to acetazolamide in patients with occlusive carotid disease].

The correlation between somatosensory evoked potential (SEP) and regional cerebral blood flow (rCBF) changes after acetazolamide administration was studied in six patients presented with transient ischemic attack (TIA) or minor completed stroke. All patients had no or only localized low density area on computed tomography, and severe occlusive disease in the ipsilateral common or internal carotid artery on cerebral angiography. In two patients with internal carotid artery occlusion, both marked decrease in ipsilateral N20 amplitude and prolongation of ipsilateral N20 latency were observed from 5-10 minutes after acetazolamide injection. These changes gradually improved and resolved 30-45 minutes after acetazolamide injection. In these cases, stable xenon CT revealed paradoxical rCBF decrease in the territory of the ipsilateral middle cerebral artery after acetazolamide injection. Especially, rCBF in the ipsilateral centrum semiovale fell to less than 20 ml/100 g/min. The other patients showed no change in SEPs and no paradoxical decrease in rCBF after acetazolamide injection. These results suggest that SEP test with acetazolamide loading could be valuable to evaluate a certain group of the patients with severely disturbed cerebral perfusion reserve in the carotid territory and suitable candidate for extracranial-intracranial arterial bypass (EC/IC bypass), although further investigations is needed.

Acetazolamide↗
PubMed1991

Membranous nephropathy with crescents in rheumatoid arthritis: a case report.

A 59-year-old man with long-standing rheumatoid arthritis (RA) developed renal dysfunction, proteinuria and hematuria. Neither gold nor penicillamine had been given. Light microscopy of a renal biopsy specimen revealed membranous nephropathy with crescents of various stages. The possible pathogenesis of such an unusual combination of membranous nephropathy and crescents in RA is discussed.

Arthritis, Rheumatoid↗
PubMed1991

[Evaluation of pulmonary venous flow pattern in hypertrophied and dilated hearts: a study with transesophageal pulsed Doppler echocardiography].

In order to evaluate the clinical significance of pulmonary venous flow (PVF) pattern, transesophageal pulsed Doppler echocardiography (TEE) was performed in 25 patients with hypertrophied heart (all with hypertrophic cardiomyopathy), 15 patients with dilated heart (10 with old myocardial infarction and 5 with dilated cardiomyopathy) and 10 normal controls. Parameters obtained from the PVF pattern were compared with those of transmitral flow (MVF) pattern, % fractional shortening (%FS) of left ventricle (LV) and amplitude of mitral anular motion (MAM) during a cardiac cycle. Results were as follows: 1. PVF pattern in cases of sinus rhythm was divided into four components, atrial systolic backward flow (PVA), ventricular systolic (PVS1, PVS2) and diastolic (PVD) forward flows. 2. In patients with dilated heart, peak velocities of PVS1 and PVS2 were markedly decreased compared with those of hypertrophied and normal hearts. 3. Peak velocity of PVD in hypertrophied and dilated hearts was significantly decreased compared with that of normal controls, and PV-D/S (ratio of peak velocity of PVD to PVS2) was significantly lower in hypertrophied heart than in normal controls. 4. Time interval from the first heart sound to the peak of PVS2 (TS) was significantly longer in dilated heart, and time interval from the second heart sound to the peak of PVD (TD) was longer in hypertrophied heart than in the other two groups. 5. MAM and %FS of dilated heart were significantly lower than those in normal and hypertrophied hearts, and peak velocity of PVS2 in dilated heart group correlated well with MAM or %FS. 6. There were significant correlations among the diastolic parameters from PVD of PVF (peak velocity of PVD, PV-D/S) and early diastolic wave (D) of MVF (peak velocity, deceleration time and deceleration of rapid filling). 7. In a case of hypertrophic cardiomyopathy with mid-diastolic wave of MVF, distinct forward wave was observed after PVD of PVF, and this wave coincided in timing with the mid-diastolic wave of MVF. 8. In a case of extensive myocardial infarction with the development of severe LV dysfunction and with "normalized" pattern of MVF, peak velocities of PVD and PVA were markedly increased, and that of PVS2 was decreased. However, the peak velocities of PVD and PVA were decreased, and that of PVS2 was increased with the fair improvement of LV dysfunction and with the compensatory augmentation of atrial contraction wave (A) of MVF.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

[SEP monitoring during balloon occlusion test or operation for vertebro-basilar aneurysms].

SEP (somatosensory evoked potential) monitoring was carried out on seven patients with vertebro-basilar aneurysms during balloon occlusion test, during operation, or after operation. In the patient (case 5) with basilar tip aneurysm, the amplitude of N20 remarkably decreased and this finding closely correlated with disturbed consciousness during transient balloon occlusion of the basilar artery. In another patient (case 6) with vertebral dissecting aneurysm, cerebellar retraction caused transient prolongation of N20 latency during operation. In another case, postoperative SEP monitoring revealed marked reduction of N20 amplitude in the patient (case 7) who showed disturbed consciousness and bilateral oculomotor palsy after operation for basilar aneurysms, but who showed no abnormality in postoperative ABR (auditory evoked brainstem response). The other four patients showed no neurological deterioration and no SEP change during transient balloon occlusion of the parent arteries. Because of the high rate of "false-negative" findings, it remains unclear whether SEP monitoring during surgery for vertebrobasilar aneurysms is of value to predict postoperative deficit due to brainstem ischemia. In our study, however, the changes of SEP were well correlated with neurological deterioration and/or the location of postoperative infarction. In conclusion, SEP monitoring during balloon occlusion tests or operations for vertebro-basilar aneurysms is considered to be useful in predicting ischemic complication of the brainstem caused by the occlusion of the parent artery. However other methodologies have to be developed in order to monitor the pyramidal tract and reticular activating system of the brainstem more accurately.

Adolescent↗