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Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Stress-induced anxiety and endogenous anxiogenic substances].

Anxiety observed in animals subjected to stress was stated in relation to anxiety level and biological backgrounds of animals, changes in neurotransmitters and causal stressors. 1. Anxiety is thought to be a negative emotion caused by many kinds of stress such as restraint stress, SART (specific alternation of rhythm in temperature) stress (a repeated cold stress caused by environmental temperature), social stress, etc. 2. Emotional behavior in those stressed animals were attenuated by anxiolytics like diazepam, a benzodiazepine receptor agonist and buspirone, a serotonin (5-HT) 1A agonist. 3. Stressed rats had changed brain levels of a variety of neurotransmitters such as corticotropin-releasing factor (CRF), noradrenaline, 5-HT, dopamine, acetylcholine, histamine, cholecystokinin, etc. The percentage of time spent on the open arms of an elevated plus-maze apparatus decreased in those stressed animals. Abnormal elevated plus-maze behaviors were attenuated by diazepam, buspiron and a CRF antagonist. 4. Anxiety level differs according to the coping strategy of the recipients. Rats of different strain, sex, aging and/or family display different behaviors in elevated plus-maze. 5. Stress-induced anxiety-related behaviors were observed when levels of some neurotransmitters became unbalanced. Thus modulators of unbalanced brain substances are thought to have anxiolytic properties.

Adaptation, Psychological↗
PubMed2000

Elevated anti-annexin V antibody levels in antiphospholipid syndrome and their involvement in antiphospholipid antibody specificities.

To clarify the involvement of annexin V (ANX) in antiphospholipid antibody (APA) specificities, we studied antiANX antibodies (aANX) using 2 kinds of enzyme-linked immunosorbent assay plates (plain and gamma-irradiated) and anti-beta 2-glycoprotein I antibodies (a-beta 2GPI) in 53 patients with antiphospholipid syndrome (APS). The incidence of aANX IgG-positive results in the autoimmune APS group was significantly higher than that of healthy control subjects. However, we could not demonstrate a significantly higher incidence in the infection- or drug-induced group. Nor could we find an increased incidence of IgM isotype. When the 2 plates were compared, the discrepancies of positivity were demonstrated in both isotypes. We speculated that these discrepancies between the plate surfaces were attributed to the altered antigenicity of ANX. Although positivity of a-beta 2GPI was associated significantly with clinical manifestations, no significant associations were demonstrated between the incidence of aANX-positive results and clinical manifestations. We inferred that the involvement of aANX in the pathogenic mechanism of APS is unlikely.

Adult↗
PubMed2000

Effects of removal and reapplication of K(+) and Cl(-) on spontaneous electrical activity, slow wave, in the circular muscle of the guinea-pig gastric antrum.

In the circular muscle of guinea-pig gastric antrum, the effects of removal and reapplication of K(+) and Cl(-) were studied on the slow wave, which consists of the lower, first and upper, second components. The first component appeared to be triggered by the driving potential generated in the interstitial cells. K(+) removal slightly depolarized the membrane, increased frequency, and shortened the first component and driving potential, and K(+) reapplication hyperpolarized and prolonged these potentials transiently. Ouabain abolished the K(+)-induced hyper-polarization but had no inhibitory effect on the K(+)-induced potentiation. The K(+)-induced prolongation was much reduced in Ca(2+)-deficient and increased in Ca(2+)-excess solution. BAPTA-AM, thapsigargin, and cyclopiazonic acid shortened the slow wave and inhibited the K(+)-induced prolongation but did not block the slow wave. Effects of Cl(-) removal were stronger than K(+) removal in shortening and increasing the frequency. In Cl(-)-deficient solution, no prolongation was observed on K(+) reapplication. Although no conclusive evidence was obtained as to the ionic mechanism involved in the effects of K(+) or Cl(-) removal and reapplication, a possibility is considered that the sarcoplasmic reticulum is involved in determining the duration of the driving potential and the first component of the slow wave.

Animals↗
PubMed2000

Effects of removal of Na(+) and Cl(-) on spontaneous electrical activity, slow wave, in the circular muscle of the guinea-pig gastric antrum.

In the circular muscle of the guinea-pig gastric antrum, a decrease in the external Na(+) to less than 20 mM produced depolarization of the membrane with transient prolongation of the slow wave. This was followed by a high rhythmic activity. The activity was inhibited by reapplication of Na(+) before recovery. The depolarization in Na(+)-deficient solution was prevented and rhythmic activity continued at about 5/min for at least 6 min by simultaneous removal of K(+), Ca(2+), or Cl(-). After exposure to a Na(+)- and Cl(-)-deficient solution for a few minutes, reapplication of the Na(+) in Cl(-)-deficient solution inhibited generation of the slow wave until Cl(-) reapplication. Similar results were obtained when Na(+) and Cl(-) were reapplied in the absence of K(+) after exposure to a Na(+)-, K(+)-free, and Cl(-)-deficient solution, although the inhibition was weaker than Na(+) reapplication in a Cl(-)-deficient solution. In the presence of furosemide or bumetanide, a strong inhibition of activity was produced by the reapplication of Na(+) and Cl(-) after exposure to an Na(+)- and Cl(-)-deficient solution. A hypothesis is presented that intracellular Ca(2+) concentration ([Ca(2+)](i)) is the most important factor determining the generation and frequency of the slow wave and that [Ca(2+)](i) is regulated by the Na(+) concentration gradient across the plasma membrane. The recovery of the Na(+) concentration gradient by Na(+) reapplication after removal of Na(+) and Cl(-) is mainly controlled by a Na(+)-K(+)-Cl(-) co-transport.

Animals↗
PubMed2000

[Surgical treatment of intracardiac tumors in 25 patients].

For most intracardiac tumors, operation is the only means of therapy. In our institute, we have aggressively performed operation for intracardiac tumors regardless of histological type because resection for tumor had a beneficial effect on the hemodynamics with congestive heart failure. Twenty-five cases of cardiac tumors were operated upon from 1980 through 1998. The follow-up period ranged from 2 months to 19 years. The histological diagnoses of the tumors were as follows: benign tumors 24 (myxoma 21, papillary fibroelastoma 1, fibroma 1, angiomyolipoma 1) and malignant tumor (angiosarcoma 1). There was one hospital death in this series. In the New York Heart Association classification, the cardiac performances of intracardiac benign tumors after operation were Class I or II. The results of surgical treatment of intracardiac benign tumors were satisfactory both in short-term and in long-term. On the other hand the long term result of malignant tumor was extremely poor. A patient with angiosarcoma died 8 months later due to bone metastasis.

Aged↗
PubMed2000

[Chromosome 1 abnormalities at band 1p32 in two atomic bomb survivors with myelodysplastic syndrome].

We reported on 2 atomic bomb survivors(a 60-year-old man and 63-year-old woman)suffering myelodysplastic syndrome(MDS) associated with 1p32 chromosomal abnormalities. They were exposed to atomic bomb radiation at distances of 1.2 and 1.1 km, respectively, and were given a diagnosis of MDS 44 and 46 years after the bombing, respectively. The male patient had refractory anemia(RA) and a bone marrow cell karyotype of 46, XY, del(1)(p22p32), t(8;11)(p11;p15). The female patient had RA with excess of blasts (RAEB) and a karyotype of 45, X, -X, t(1;11)(p32;q23), +del(1)(p32), inv(3) (p21q27), del(5)(q15), -6, -9, -19, +mar 1, +mar 2. Multi-separated nuclear megakaryocytes were observed in both patients. These findings suggested that they had been exposed to radiation near the atomic explosion despite the fact that their symptoms of MDS developed more than 40 years after the bombing. 1p32 is known to be the locus of the TAL1 gene. However, Southern blot analysis did not reveal rearrangement of the TAL1 gene in the male patient.

Chromosome Aberrations↗
PubMed2000

[Combined valvular and coronary artery surgery].

Between 1990 and 1999, 78 patients underwent combined valvular coronary artery operation. Aortic valve disease was present in 49 patients, mitral valve disease in 23 patients, aortic and mitral valve disease in 6 patients. The average age was 67 years. Twelve patients had had a previous myocardial infarction. The average number of grafts inserted was 1.82 per patients, and the average number of artery grafts inserted was 0.96 per patients. The most number of grafts were placed prior to valve replacement or plasty. And periods of myocardial ischemia were kept at a minimum by coronary perfusion through free grafts. Preoperative mortality was 1.3%. And event fee ratio after operation was 95% (mean follow up 42 month). Therefore the operative risk of combined surgery is, in general, low and the long term results are favorable.

Aged↗
PubMed2000

[A case report of aneurysm of the ductus arteriosus combined with mitral regurgitation].

A case with the giant aneurysm of the ductus arteriosus combined with severe mitral regurgitation is reported. 58-year-old male underwent MVR and patch closure of the ductal orifice for staged operation. The first operation was MVR and patch closure of the PDA orifice of the pulmonary artery end using retrograde cerebral perfusion (RCP) with deep hypothermic circulatory arrest (DHC). The second operation was performed on 3 months after the first operation using left thoracotomy approach, and patch closure of the ductal orifice via the aorta using RCP with DHC was performed. Upon following-up examination, the patient is now doing well 20 months after the initial surgery.

Cerebrovascular Circulation↗
PubMed2000

Three-dimensional sonographic features of fetal central nervous system anomaly.

OBJECTIVE: To visualize an intracranial structure of the fetal central nervous system (CNS) anomaly using transabdominal three-dimensional (3D) sonography. METHODS: A total of 12 cases with fetal CNS anomalies (one unilateral ventriculomegaly; three hydrocephalus; three anencephaly; three holoprosencephaly; one Dandy-Walker cyst; and one enlarged cisterna magna) from 17 to 37 weeks of gestation were studied with transabdominal 3D sonography (3.5 MHz). RESULTS: In unilateral ventriculomegaly, insight view of dilated lateral ventricle, especially dilated atrium was depicted. In hydrocephalus, severely dilated bilateral ventricles and thin brain mantle were very clearly shown. In anencephalus, an absence of the brain and defect of the vault of the skull was clearly noted. In holoprosencephaly, absent interhemispheric fissure, common ventricle, and the extent of thalamic fusion were evident. In Dandy-Walker cyst, cerebellar hemisphere was clearly depicted due to the agenesis of cerebellar vermis. In enlarged cisterna magna, posterior intracranial view of the fetus showed a large space of cisterna magna. Although the diagnosis of each CNS anomaly was made using conventional two-dimensional sonography, 3D sonography proved most helpful delineating the exact nature and anatomic level of the anomaly. CONCLUSIONS: These results suggest that 3D sonography provides a novel means of visualizing fetal CNS anomalies in utero. However, it should be noted that our 3D sonography cannot depict intracranial brain structures in normal fetuses or some CNS anomaly such as intracranial tumor.

Adult↗
PubMed2000

[Predictors of prognosis after angioplasty in the unprotected left main coronary artery].

OBJECTIVES: The short-term and long-term predictors of outcome after coronary angioplasty in the unprotected left main coronary artery were investigated. METHODS: The procedure was performed in 122 consecutive patients for de novo lesions without myocardial infarction in our hospital between April 1986 and October 1998, including 16 emergency cases. Procedures were directional coronary atherectomy (73 patients), balloon angioplasty (31 patients), and stent implantation (18 patients). There were 101 males and mean age was 68 +/- 10 years. Follow-up angiography was performed in 98% of discharged patients, and all patients were clinically followed up for more than 1 year. Clinical and angiographic predictors of in-hospital and long-term outcome were evaluated. RESULTS: The in-hospital mortality was 5.7% (7 of 122 patients). Multivariate analysis revealed that more patients were admitted as emergency cases (57% vs 10%, p = 0.0088), with left ventricular ejection fraction < or = 35% (57% vs 22%, p = 0.029) and renal failure (43% vs 3%, p = 0.0004) finally died. Mean follow-up period was 3.5 years. Estimated survival rate was 77.1%, and cardiac-death free survival rate was 81.0% at 5 years by the Kaplan-Meier method. Univariate analysis showed that the predictors of cardiac death were emergency angioplasty, renal failure, decreased left ventricular ejection fraction, multivessel disease and unstable angina and/or congestive heart failure. Cox's regression model showed that renal failure (p = 0.0004) and multivessel disease (p = 0.0075) were significant predictors of long-term prognosis. CONCLUSIONS: Renal failure was the strongest predictor of outcome after unprotected left main coronary artery angioplasty.

Aged↗
PubMed2000

[Evaluation of hepatic resection following hepatic arterial infusion chemotherapy for colorectal liver metastases].

We evaluated the significance of hepatectomy following hepatic arterial infusion (HAI) chemotherapy for colorectal liver metastases. The prognosis of 4 cases with initially resectable tumors was discouraging, indicating no benefit of preoperative HAI for resectable tumors. The 2- and 3-year survival of patients who underwent hepatectomy after downstaging by HAI of originally unresectable metastases were 100% and 67%, respectively, suggesting that hepatectomy combined with HAI is a promising modality for those patients. However, it seems that the control of extrahepatic disease and decision making for the timing for surgical therapy are issues requiring improvement.

Aged↗
PubMed2000

[Malignant islet cell tumor of the pancreas with multiple liver metastases effectively treated by transcatheter arterial embolization with degradable starch microspheres--a case report].

A 57-year-old woman underwent distal pancreatectomy for malignant islet cell tumor of the pancreas in 1991. One year later, multiple liver metastases appeared. Although three transcatheter arterial embolizations (TAE) with spongel and nine ethanol injections were performed over seven years, the tumors were growing gradually. Therefore, TAE with degradable starch microspheres (DSM) was selected. Under angiography, TAE of the left hepatic artery was done using 900 mg of DSM following injection of Farumorubicin (20 mg), Lipiodol (3 ml) and cisplatin (90 mg). The tumors in the embolized hepatic area were remarkably decreased in size, and satisfactory local control was obtained. Thereafter, TAE with DSM was carried out twice, and she is still living with outpatient treatment. Thus, it is suggested that TAE with DSM could be a promising, alternative therapeutic modality for liver metastases from malignant islet cell tumor of the pancreas.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Fas-resistance in ATL cell lines not associated with HTLV-I or FAP-1 production.

A preventive role for human T-cell leukemia virus type-I (HTLV-I) and Fas-associated phosphatase-1 (FAP-1) in Fas-mediated apoptosis has been reported in HTLV-I-infected cells. In the present study, we examined whether these molecules increased during the acquisition of Fas-resistance in adult T-cell leukemia (ATL) cell lines. SO4, ST1 and KK1 are Fas-sensitive ATL cell lines, and produce small amounts of HTLV-I in vitro. Although their subclones RSO4 and RST1 are completely Fas-resistant, they produced an equivalent amount of HTLV-I to SO4 and ST1. Moreover, FAP-1 mRNA was not detected in these cell lines irrespective of Fas sensitivity. Thus, Fas resistance in ATL cells was not directly associated with the increased production of HTLV-I or FAP-1.

Antibodies, Monoclonal↗
PubMed1999

Purification and characterization of two amine N-sulfotransferases, AST-RB1 (ST3A1) and AST-RB2 (ST2A8), from liver cytosols of male rabbits.

Two sulfotransferases (STs), designated as AST-RB1 (ST3A1) and AST-RB2 (ST2A8), with high a amine N-sulfonating activity, were purified from male rabbit liver cytosols. AST-RB1 and AST-RB2 were purified to homogeneity by the anion-exchange, affinity, and hydroxyapatite chromatography. The N-terminus of both enzymes were blocked. The subunit molecular mass of both enzymes was estimated to be 34 kDa on SDS-PAGE. AST-RB1 efficiently catalyzed N-sulfonation of alicyclic, alkyl, and arylamines such as 4-phenyl-1,2,3, 6-tetrahydropyridine, 1-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-piperazine, desipramine, and aniline, whereas its catalytic activities toward 2-naphthol and dehydroepiandrosterone (DHEA) were very low. On the other hand, AST-RB2 efficiently catalyzed sulfonation of desipramine and DHEA, but had no activity toward 2-naphthol. Amino acid sequences of peptide fragments derived from the purified AST-RB1 showed no significant homology with previously reported STs, but those from the purified AST-RB2 shared a high similarity with those of the ST2 family. Both enzymes were expressed specifically in the liver. The present results strongly suggest that the purified AST-RB1 is a novel enzyme in terms of structure and catalytic properties showing high selectivity for amine substrates, and AST-RB2 is a quite unique from among ST2A enzymes of other species in its substrate specificity.

Amines↗
PubMed1999

Initial and long-term results of angioplasty in unprotected left main coronary artery.

Angioplasty of the unprotected left main coronary artery (LMCA) has been controversial. Although recent single-center studies suggest that new devices may change the situation, many questions and problems remain. Therefore, the results of unprotected left main coronary angioplasty of 175 procedures in 107 patients were analyzed to evaluate its feasibility and effectiveness. The treatment of the initial 107 cases included balloon angioplasty (39 cases, 36%), directional coronary atherectomy (53 cases, 50%), and stents (15 cases, 14%). They were divided into 3 major subgroups: (1) acute group (n = 14), in which LMCA angioplasty was performed in patients with acute myocardial infarction; (2) emergency group (n = 10); and (3) elective group (n = 83). In-hospital mortality was higher in the acute (35.7%) and emergency (40.0%) groups than in the elective group (3.6%; p <0.0001). Angiographic follow-up was routinely performed and the restenosis rate including in-hospital restenosis was 70% in the acute group, 37.5% in the emergency group, and 40% in the elective group (p = NS). The mean clinical follow-up period was 2.9 years, and the estimated 5-year survival rates of the acute and emergency groups were 50% and 48.2%, respectively. However the 5-year survival rate of the elective group was higher than that seen in the acute or emergency group (77.5%; p <0.05). Repeat LMCA angioplasty was performed in 37 of 68 patients with 8.8% mortality (38.5% of acute and emergency cases and 1.8% of elective cases). The results indicated that elective unprotected LMCA angioplasty is relatively feasible and effective under scheduled angiographic follow-up.

Adult↗
PubMed1999

Extracellular matrix regulation in the development of Syrian cardiomyopathic Bio 14.6 and Bio 53.58 hamsters.

The myocardium contains a collagen matrix composed primarily of collagen and fibronectin, which are major determinants of the myocardial architecture, structural integrity and mechanical properties. The present study was undertaken to determine the age-related changes of the accumulation and degradation of the collagen matrix in Syrian myopathic hamsters, of the Bio 14.6 and Bio 53.58 strains. Those hamsters were used as models for hypertrophic and dilated cardiomyopathy, respectively. The heart to body weight ratio in the Bio 14.6 strains was higher (P<0.05) than that in the age-matched F1b strains. In the Bio 53.58 strains, the heart to body weight ratio was higher at 8 and 42 weeks of age than that in the F1b strains. The collagen content increased from 22 weeks of age in both Bio hamsters compared with age-matched F1b hamsters (P<0.05). In both cardiomyopathic hamsters, the mRNA expressions for type I and type III collagen and fibronectin all increased with aging; however, the fibronectin expression in the Bio 14.6 strains increased more at 22 weeks of age than at 42 weeks of age. The left ventricular MMP-1, MMP-2 and MMP-9 activities in Bio 53.58 strains increased with aging. However, in the Bio 14.6 strains, although MMP-1 activities increased with aging, MMP-2 and MMP-9 activities decreased at 42 weeks of age in comparison to those at 22 weeks of age. Thus, the MMP activation differed between two cardiomyopathic models at the stage of heart failure, although the collagen synthesis was elevated in both models. In conclusion, it would seem that the relative balance between the synthesis and the removal of collagen may contribute to the changes in the left ventricular geometry in two different types of cardiomyopathy.

Aging↗