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Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 343 records · Page 19Linked to original sources
PubMed1992

New pelvic sonoangiography for detection of endometrial carcinoma: a preliminary report.

Pelvic sonoangiography (PSAG) using transvaginal color Doppler was done on 16 postmenopausal patients with abnormal uterine bleeding. Seven women had no endometrial carcinoma and nine had carcinoma. No flow was detected around and within the endometrium in noncancer patients. PSAG showed a feeder artery (blood flow with pulsation that runs into and clings to the tumor) in all patients with endometrial carcinoma, and intratumor blood flow (a mixture of pulsating and constant flow within the tumor) was evident in 7 of 9 patients with endometrial carcinoma. These findings were confirmed by conventional pelvic angiography. In the diagnostic evaluation of PSAG for endometrial carcinoma, both sensitivity and specificity were 100%. We conclude that PSAG with transvaginal color Doppler can be used to detect endometrial carcinoma in postmenopausal women with abnormal uterine bleeding and that this method might be applicable to selecting patients who really require diagnostic surgery for endometrial cancer.

Aged↗
PubMed1992

Ovarian tumors of low malignant potential: transvaginal Doppler ultrasound features.

Twenty-nine patients with ovarian tumors were studied with transvaginal Doppler ultrasound before surgery. After surgery, pathological examination revealed that 26 tumors were benign and 3 were of low malignant potential (LMP). B-mode sonography, computed tomography, and magnetic resonance imaging showed no positive findings for malignancy in these 3 cases of LMP. Serum levels of the CA-125, tissue polypeptide antigen, and carcinoembryonic antigen were also within the normal range. Blood flow velocity waveforms were evaluated by the calculation of the resistance index (RI). There was a significant difference between the RI value (0.818 +/- 0.223) in benign tumors and that (0.418 +/- 0.072) in LMP (P less than 0.01). When the 0.56 (mean of LMP tumor RI value + 2SD) was considered as the cutoff value of RI, the sensitivity was 100% and the specificity was 88.5%. Transvaginal Doppler ultrasound provides a useful diagnostic information for the differentiation of benign and LMP ovarian tumors before surgery.

Adult↗
PubMed1992

Sarcolemmal Na(+)-K(+)-ATPase activity in congestive heart failure due to myocardial infarction.

Because the Na+ pump is considered to modulate the contractile force development by the cardiac muscle and depressed cardiac pump function is the hallmark of congestive heart failure, we characterized the sarcolemmal Na(+)-K(+)-ATPase activity in failing rat hearts after myocardial infarction. For this purpose, the left ventricular coronary artery was ligated, and hearts were examined 4, 8, and 16 wk later; sham-operated animals served as controls. Hemodynamic assessment revealed the presence of abnormal cardiac function at 4, 8, and 16 wk. Although accumulation of ascites in the abdominal cavity was present in experimental animals at 4 wk, other clinical signs of congestive heart failure in experimental rats including lung congestion and cardiac dilatation were evident 8 and 16 wk after induction of myocardial infarction. The depression in Na(+)-K(+)-ATPase activity in purified sarcolemmal membrane from the uninfarcted experimental left ventricle at 8 wk was associated with depressed Vmax without any changes in the affinities for Mg-ATP, Na+, and K+ or the pH optimum for the enzyme. The Kd values of both the high- and low-affinity binding sites for [3H]ouabain, which is believed to interact with Na(+)-K(+)-ATPase, were increased; however, no change in the density of either class of ouabain binding site was evident. The depression of Na(+)-K(+)-ATPase activity in failing hearts at 16 wk of myocardial infarction was not different from that observed at 8 wk but the enzyme activity was not altered at 4 wk of coronary occlusion. These data support the view that depression of Na(+)-K(+)-ATPase activity may serve as an adaptive mechanism during the development of congestive heart failure.

Alamethicin↗
PubMed1992

Sarcolemmal calcium transport in congestive heart failure due to myocardial infarction in rats.

Because Na(+)-Ca2+ exchange and Ca2+ pump are thought to play a role in sarcolemmal Ca2+ movements, we examined the Na(+)-dependent Ca(2+)-uptake and ATP-dependent Ca(2+)-uptake activities in failing heart after myocardial infarction in rats. The left coronary artery was ligated, and the viable left ventricle was used 4, 8, and 16 wk later; sham-operated animals served as controls. Increased left ventricular diastolic pressure and decreased positive and negative change in pressure over time were observed in experimental animals at 4, 8, and 16 wk; these changes were associated with accumulation of fluid in the abdominal cavity. The sarcolemmal Na(+)-dependent Ca2+ uptake was depressed in 4-, 8-, and 16-wk experimental hearts. The decrease in sarcolemmal Na(+)-dependent Ca2+ uptake in failing hearts was seen when the activity was assayed either as a function of time or Ca2+ concentration; a depression of maximal velocity without any change in activity constant for Ca2+ was observed. No alteration in the Ca2+ pump (ATP-dependent Ca2+ accumulation and Ca(2+)-stimulated adenosinetriphosphatase) activities was evident in the 4-, 8-, and 16-wk experimental groups. These data suggest that changes in the Na(+)-dependent Ca2+ handling by the sarcolemmal membrane may be associated with contractile abnormalities in this model of congestive heart failure.

Adenosine Triphosphate↗
PubMed1992

Coexistence of the Ekbom syndrome and lilliputian hallucination.

A patient who showed Ekbom's syndrome, i.e. delusions of parasitosis, and also lilliputian hallucination is described. She was diagnosed as senile dementia based on the diagnostic criteria of DSM-III-R and cerebral imaging techniques. When she was 74 years, she felt a mowworm-like wriggle in her stomach and their travels all over her body. When she was 78 years, she saw dressed-up dwarfs dance or march on her abdomen. Since the case showed simultaneously delusions of parasitosis and lilliputian hallucinations, it cannot be denied that she has undetected lesions in the brainstem. In this case, the delusions and hallucinations seem to have occurred as a part of psychopathological signs of senile dementia.

Aged↗
PubMed1992

Fetal atrial measurements before and after delivery: correlation with plasma atrial natriuretic peptide.

Fetal and early neonatal atrial measurements correlating with plasma atrial natriuretic peptide were studied to evaluate the circulatory change before and after delivery in a longitudinal study of 10 normal fetuses from 1 week before until 5 days after delivery. Before delivery, right atrial area value was significantly larger than that of left atrial area; however, there were no significant differences between left and right atrial areas after delivery. Right atrial area value before delivery was significantly larger than those after delivery, whereas the left atrial area did not change before and after delivery. Combined atrial area value before delivery was also larger than those after delivery. Plasma atrial natriuretic peptide values did not change after delivery. These results suggest that the change from fetal to neonatal circulation mainly caused by the pulmonary circulation induces the change of right atrial size before and after delivery.

Atrial Natriuretic Factor↗
PubMed1992

Effects of (+)-, (-)- and (+/-)-indenestrols A and B on microtubule polymerization.

Indenestrol A (IA) is a metabolite of diethylstilbestrol (DES), and indenestrol B (IB) is an analog of IA. IA was simply obtained from E,E-dienestrol in the presence of dilute sulfuric acid, and a mixture of IA and IB was formed by thermal cyclization of E,E-dienestrol. In order to elucidate the effects of optically active IA and IB on microtubule assembly, the IA and IB enantiomers were separated to greater than 99% purity by high-pressure liquid chromatography using a chiral column. The di(4-bromobenzoate) of (-)-IB was analyzed by X-ray crystallography and its absolute structure was determined as C(3)-S. The (+)-, (-)-, and (+/-)-indenestrols A and B were shown to be inhibitors of microtubule assembly in vitro using microtubule proteins from porcine brain. (+/-)-IB is more active than (+/-)-IA, and the order of inhibitory activity of the enantiomers on microtubule assembly was (+)-IB greater than (+)-IA greater than (-)-IA greater than (-)-IB.

Animals↗
PubMed1992

[Effects of Kamikihi-To on autonomic imbalances in SART-stressed (repeated cold-stressed) mice].

The effects of Kamikihi-To (KMK), a traditional Chinese medicine, on autonomic imbalances were evaluated in SART-stressed (repeated cold-stressed) mice. These animals exhibited decreases in pain threshold and contraction of duodenum by acetylcholine, and they showed changes in their electrocardiogram and hematological parameters. All symptoms are thought to be caused by dysautonomia. KMK in dosages of 0.5 and 1.0 g/kg were administered to mice once a day for 8 consecutive days. SART stress was induced from the second day. KMK prevented the decrease in the pain threshold and contraction of the duodenum, although it had no effect on the electrocardiographic or hematological changes. KMK had no similar effect on unstressed mice. This data suggests that KMK might be useful for the treatment of clinical autonomic imbalances.

Acetylcholine↗
PubMed1992

Regulatory effect of neurotropin on nasal mucosal hypersensitivity in guinea pigs caused by SART (intermittent exposure to cold) stress.

We stated that SART-stressed guinea pigs showing nasal mucosal hypersensitivity would serve as an animal model for the in vivo evaluation of antiallergic drugs. In the present study, the mode of action of Neurotropin on nasal allergy compared with those of antiallergic drugs was studied by using SART-stressed guinea pigs. Daily administrations of Neurotropin improved the methacholine-induced hypersecretion and histamine-evoked sneeze response, which are parameters of nasal mucosal hypersensitivity, and increased the density of muscarinic ACh receptors located on the nasal mucosa caused by SART stress. In addition, the inhibitory action on nasal secretion in a passively sensitized model was more intense in SART-stressed guinea pigs than in normal ones. Ketotifen and tranilast were also found to have marked effects on nasal secretion in the passively sensitized SART-stressed model, but only had weak effects on nasal mucosal hypersensitivity. Neurotropin significantly potentiated the action of ketotifen or tranilast. Thus, at least part of the inhibitory effect of Neurotropin on nasal symptoms such as watery secretion and sneezing is thought to have been brought forth through the regulatory action on nasal mucosal hypersensitivity, and its combined use with antiallergic drugs would be a very effective therapeutic regimen for nasal allergy.

Analgesics↗
PubMed1992

Relationship between density of muscarinic receptors and nasal hypersecretion in a nasal allergic model.

In guinea pigs actively sensitized with ovalbumin, we have observed that nasal hyperreactivity and hypersensitivity to methacholine causes nasal secretion accompanied by an increase in the density of muscarinic acetylcholine receptor (m-ACh.R) following the appearance of nasal symptoms induced by the ovalbumin challenge. Therefore in the present investigation, we studied the relationship between the density of m-ACh.R and nasal hypersecretion in actively sensitized guinea pigs. There was no relationship between the quantity of nasal secretion and serum Ig G1 or Ig E levels. On the other hand, the sensitivity to methacholine and nasal secretion induced by methacholine were significantly related to the density of m-ACh.R located on the nasal mucosa. The quantity of nasal secretion induced by allergen was also correlated significantly to the density of m-ACh.R. These results suggest that the nasal hypersecretion observed in the nasal allergic model may be closely associated with an increase in the density of m-ACh.R located on the nasal mucosa.

Animals↗
PubMed1992

Role of the sympathetic system in impairment of the cerebrovascular CO2 responsiveness during moderate hypoglycemia.

We examined the mechanism of impairment of the cerebrovascular CO2 responsiveness in moderate hypoglycemia. Twelve fasted cats were used. The brain-PO2, brain-PCO2 and brain-pH were measured continuously with electrodes placed on the brain surface. Hypoglycemia was induced with insulin. Intravenous injection of hexamethonium (a sympathetic ganglion blocker, C6; 0.1 mg/kg) was performed at the following stages: Control, hypoglycemia and recovery. Before and after the C6 administration, 5% CO2 in air was inhaled for 3 min at the respective stages. The CO2 responsiveness (cerebrovascular dilatory response to increased PaCO2) at the control stage was not altered after the ganglionic blockade. At the hypoglycemic stage, the increase in BrPO2 by CO2 inhalation was significantly less than that at the control stage. This reduction of delta BrPO2 was significantly improved after the administration of C6. At the recovery stage, the CO2 responsiveness before and after the administration of C6 was not significantly different. An impaired CO2 responsiveness in the hypoglycemic state was improved by sympathetic ganglion blockade with C6 which did not alter the reactivity during normoglycemia. It is suggested that the sympathetic activity plays an important role in impairment of the cerebrovascular CO2 responsiveness during moderate hypoglycemia.

Animals↗
PubMed1992

[Effect of antihypertensive treatment in elderly hypertensive patients with cardiac hypertrophy].

In elderly hypertensive patients effect of antihypertensive treatment with Ca antagonist or ACE inhibitor on the heart were examined. Twenty-four elderly hypertensive patients with cardiac hypertrophy, aged 65-79 years old (mean +/- SEM, 71 +/- 1) were treated with Ca antagonist (nifedipine or nicardipine) or ACE inhibitor (captopril or enalapril) for 3 months. Thirteen patients had essential hypertension (EH: SBP greater than or equal to 160 mmHg and DBP greater than or equal to 95 mmHg, 70 +/- 1 years) and 11 had isolated systolic hypertension (ISH: SBP greater than or equal to 160 mmHg and DBP less than 95 mmHg, 74 +/- 2 years). Blood pressure (BP) and heart rate were measured every two weeks. In all patients, M-mode echocardiography was performed to measure left ventricular mass index (LVMI) and ejection fraction (EF), and the sympathetic nervous (plasma norepinephrine and epinephrine) and the renin-angiotensin system (plasma renin activity and aldosterone concentration), were assessed before and after 3 months of treatment. BP significantly decreased from 174 +/- 3/97 +/- 1 to 149 +/- 4/84 +/- 2 mmHg in EH and from 167 +/- 3/82 +/- 2 to 144 +/- 4/74 +/- 2 mmHg in ISH. LVMI was significantly reduced from 204 +/- 14 to 174 +/- 16 g/m2 in EH and from 179 +/- 14 to 156 +/- 12 g/m2 in ISH. EF showed no significant changes in either group. In ISH, the change in LVMI was significantly correlated with the change in systolic BP (r = 0.74, p less than 0.05). In EH, there was no significant relation between BP and LVMI changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Alkylation reaction of phosphorus oxyacids.

Alkylation reactions of phosphorus oxyacids (i.e. phosphoric acid, phosphorous acid, hypophosphorous acid) were examined by means of several methods for the synthesis of the corresponding esters. These reactions were applied to the synthesis of oligonucleotide having phosphotriester bond or phosphonate diester bond.

Alkylation↗
PubMed1992

[Neurological and neuroimaging studies of eclampsia].

Clinical and neuroimaging studies were made in twenty-one patients during the attack of eclampsia. Most frequent neurological signs and symptoms were the impairment of consciousness, headache, seizure and visual disturbance. Mean arterial blood pressure increased by 46 mmHg (n = 21) during the attacks. Eight of 9 patients studied by CT and/or MRI showed transient abnormalities on brain images during the attack in the occipital cortex, basal ganglia, and internal and external capsule. The findings were compatible with brain edema and were seen mainly in the white matter. Cerebral blood flow measured by SPECT method in one patient during an attack with visual disturbance showed increased blood flow in the occipital cortex. Acute increase in blood pressure, cerebral hyperperfusion and edema, similar to the pathophysiology of hypertensive encephalopathy, were considered to play an important role in the pathogenesis of eclampsia.

Adult↗
PubMed1992

[Left ventricular systolic time intervals during paroxysmal supraventricular tachycardia: the difference between A-V nodal re-entry and A-V re-entry].

In this study, the differences in hemodynamic changes during paroxysmal supraventricular tachycardia (PSVT) between A-V nodal re-entry and A-V re-entry were evaluated. In 8 patients with A-V nodal re-entrant tachycardia and 10 with A-V re-entrant tachycardia, electrophysiological studies were performed to measure systolic time intervals (pre-ejection period: PEP, ejection time: ET, PEP/ET ratio: PEP/ET). These measurements were obtained in the control state (atrial pacing at 90/min) and during PSVT with simultaneous recordings of electrocardiogram and femoral arterial pulse tracing. During PSVT, there was no difference in the heart rate between the 2 groups, but ventriculo-atrial conduction time was shorter in A-V nodal re-entry than in A-V re-entry. There was a marked fall in the ET and an increase in PEP/ET in all the patients when PSVT was induced. PEP increased significantly in A-V nodal re-entry, but did not change in A-V re-entry. This resulted in a greater increase in the PEP/ET suggesting a greater deterioration of the hemodynamic consequences in A-V nodal re-entry than in A-V re-ent y. Thus, the hemodynamic changes of PSVT differ between these 2 types of re-entrant circuits, which are mainly influenced by the ventriculo-atrial conduction time.

Adult↗
PubMed1992

[A case of medically treated type A acute aortic dissection: trial of antifibrinolytic therapy while monitoring the thrombotic and fibrinolytic parameters].

A 56-year-old male was admitted with severe chest and abdominal pain. Enhanced CT revealed type-A acute aortic dissection. Enhancement of false lumen was complete in the aortic arch, but it was incomplete in the ascending and descending aorta. This finding suggested a thrombosing tendency of the false lumen. Marked elevation of Thrombin-Antithrombin III complex (TAT) and Plasmin-alpha 2 Plasmin inhibitor complex (PIC) indicated the activation of both coagulation and fibrinolysis in the false lumen. Aprotinin and Tranexamic acid were used in order to suppress the fibrinolysis. Both TAT and PIC were completely normalized at the 20th hospital day. Enhanced CT on the 40th hospital day showed that the false lumen had disappeared, and the adventitia had thickened. Care should be taken to notice activated coagulation and fibrinolysis in the false lumen. This report appears to be the first statement about the effectiveness of antifibrinolytic therapy to facilitate thrombosing and healing of the false lumen in the treatment of acute aortic dissection.

Acute Disease↗