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Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 199 records · Page 11Linked to original sources
PubMed1997

Doppler ultrasound in a patient with ovarian Brenner tumor of low malignant potential: comparison with Gray-scale ultrasound, magnetic resonance imaging and tumor marker suggesting malignancy.

We present a postmenopausal patient with giant lower abdominal tumor. Gray-scale ultrasound and magnetic resonance imaging showed typical abnormal morphology suggesting malignancy. The serum CA 125 level was 69 U/ml, and that of CA 19-9 was 2,097 ng/ml. Transvaginal color and pulsed Doppler sonography of the tumor vasculature demonstrated low peak systolic velocity (6.7 cm/s) with low pulsatility (resistance index: 0.49). Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. Histological diagnosis was ovarian Brenner tumor of low malignant potential. Transvaginal Doppler findings seemed to give specific information for the diagnosis in this case.

Aged↗
PubMed1997

Interleukin-4, interleukin-10, and soluble tumor necrosis factor receptors in cord blood.

OBJECTIVE: We assessed cord blood for levels of interleukin-4 (IL-4), interleukin-10 (IL-10), and p55 (sTNFR-I) and p75 (sTNFR-II) soluble tumor necrosis factor receptors. STUDY DESIGN: Umbilical cord IL-4, IL-10, tumor necrosis factor alpha (TNF alpha), sTNFR-I, and sTNFR-II were measured in 21 normal appropriately grown newborns delivered vaginally (normal pregnancy), and 3 abnormal pregnancies (1 preterm delivery, 1 premature rupture of membranes with chorioamnionitis, and 1 abruptio placentae with fetal and neonatal distress). Umbilical cord arterial blood pH and PO2 were also measured. RESULTS: The TNF alpha, sTNFR-I, and sTNFR-II were detectable in all cord blood samples in normal pregnancies. IL-4 was detected in 10 of 21 samples (47.6%), and IL-10 was undetectable in normal pregnancies. IL-10 could be detected in the cases with chorioamnionitis and abruptio placentae. Soluble tumor necrosis factor receptors in the case with preterm delivery and the case with abruptio placentae were elevated compared with the levels in control samples. CONCLUSION: Both the p55 and p75 soluble tumor necrosis factor receptors are physiologic constituents of term cord blood. An immunosuppressive role of IL-10 and a protective role of soluble tumor necrosis factor receptors are suggested in abnormal pregnancies. However, in view of the small number of abnormal pregnancies, these observations must be considered preliminary.

Abruptio Placentae↗
PubMed1997

Antenatal diagnosis of aberrant umbilical vessels.

OBJECTIVE: To evaluate the antenatal screening of aberrant umbilical vessels and assess the association of fetal abnormality with these entities. STUDY DESIGN: 444 pregnant women were studied with routine obstetric ultrasound and Doppler color flow imaging in late second trimester or early third trimester. Fetal growth and anomaly, and the number of umbilical cord vessels were screened. RESULTS: Out of 444 subjects, 3 cases with discordant umbilical artery, 2 with four vessels in the umbilical cord, and 1 with single umbilical artery were detected (1.4%). Fetal anomaly was noted in 2 of 6 cases with aberrant umbilical vessels (33.3%). CONCLUSION: These results suggest that antenatal screening of umbilical cord vessels is necessary for detection of fetal anomalies.

Congenital Abnormalities↗
PubMed1997

Converting enzyme inhibitor improves forearm reactive hyperemia in essential hypertension.

Endothelial function is known to be impaired in essential hypertensive patients. In this study, we examined whether antihypertensive drugs improve forearm vasodilatory response to reactive hyperemia in 26 patients with essential hypertension (62 +/- 2 years) without diabetes mellitus, hyperlipidemia, coronary heart disease, or cerebrovascular disease. Antihypertensive drugs were never given or were discontinued for at least 4 weeks before the study. Patients were treated with monotherapy of either temocapril (2 or 4 mg, n = 15) or amlodipine (2.5 or 5 mg, n = 11) for 6 months. Forearm blood flow was measured by strain-gauge plethysmography. Vasodilator response to the release of upper arm compression at 300 mm Hg for 5 minutes and to sublingual administration of nitroglycerin (0.3 mg) were assessed. Changes of forearm blood flow response to reactive hyperemia were significantly less in hypertensive patients (99 +/- 18%) than in age-matched normotensive control subjects (150 +/- 22%, P < .01, n = 39). Blood pressure (mm Hg) was similarly decreased by the treatment with temocapril (160 +/- 4/94 +/- 2 to 139 +/- 3/83 +/- 3, P < .001) or amlodipine (165 +/- 5/94 +/- 3 to 141 +/- 4/82 +/- 3, P < .001). Response to nitroglycerin was not changed by either drug. Forearm vasodilatory response to reactive hyperemia was improved by temocapril (102 +/- 20% to 168 +/- 25%, P < .01) but not by amlodipine (97 +/- 16% to 114 +/- 14%, NS). These results indicate that the treatment with the angiotensin-converting enzyme inhibitor temocapril improved forearm vasodilatory response to reactive hyperemia, suggesting its beneficial effect on endothelial function.

Aged↗
PubMed1997

Molecular mechanism of angiotensin II type I and type II receptors in cardiac hypertrophy of spontaneously hypertensive rats.

We administered angiotensin (Ang) II receptor type 1 (AT1) blockade (losartan; 10 or 40 mg/kg per day), type II receptor (AT2) blockades (PD123319; 100 mg/kg per day), or angiotensin-converting enzyme (ACE) inhibitor (enalapril; 30 mg/kg per day) to spontaneously hypertensive rats (SHR) from 10 to 20 weeks of age. At the end of the treatment, high doses of losartan and enalapril significantly reduced the arterial systolic blood pressure compared with the untreated SHR to the level of WKY rats. But low doses of losartan and PD123319 were without effect. High doses of losartan and enalapril also significantly reduced both the left ventricular (LV) weight and the ratio of LV to body weight compared with the untreated SHR, which were still larger than that of WKY rats. However, the collagen concentration of SHR treated with high doses of losartan or enalapril was completely reduced to the level of WKY rats. Using reverse transcription polymerase chain reaction, we examined the mRNA expression for ACE, AT1, and AT2 in experimental animals. The enhanced AT1 mRNA expression was significantly decreased in the SHR treated with a high dose of losartan or PD123319 compared with the untreated SHR. The level of ACE mRNA was also decreased in the SHR treated with a high dose of losartan or enalapril. The level of AT2 mRNA was not significantly different between the Wistar-Kyoto rats and the SHR; however, this expression was decreased significantly after the treatment with a high dose of losartan or PD123319. These results indicate that AT1 receptor and ACE, but not AT2 receptor, play a crucial role in the remodeling of matrix tissue but a smaller role in the development of the hypertrophy of LV myocyte in SHR and that the LV/body weight changes do not fully account for the complete suppression of hypertension.

Angiotensin Receptor Antagonists↗
PubMed1997

Osteotropic drug delivery system (ODDS) based on bisphosphonic prodrug. V. Biological disposition and targeting characteristics of osteotropic estradiol.

An osteotropic drug delivery system (ODDS) based on a bisphosphonic prodrug has been developed for 17 beta-estradiol (E2) to improve patient compliance in estrogen replacement therapy of postmenopausal osteoporosis. The biological disposition and the targeting efficiency of a bisphosphonic prodrug of E2, disodium [17 beta-(3'-hydroxy-1',3',5'-estratrienyloxy)carbonylpropyl carboxamidomethylene]bisphosphonate (E2-BP), was investigated in ovariectomized rats. After intravenous injection, E2-BP was rapidly taken up into the bone and subsequently cleared from the bone at a half-life of 13.5 d. The bone concentration of regenerated E2 was maintained throughout 28 d. In contrast, E2 injected intravenously showed extremely low bone distribution and rapid clearance from the bone, and E2 administered orally showed even lower bone distribution. Therapeutic availability (TA) and drug targeting index (DTI), which were calculated on the basis of the AUCs for E2 in the bone and plasma after injection of E2-BP and E2, were 64.6 and 451, respectively. These results suggest that ODDS has a potential to improve not only the apparent potency but also the therapeutic index of E2. As compared with the conventional estrogenic products, E2-BP should improve patient compliance with lower adverse effects and less frequent medication in long-term estrogen replacement therapy.

Animals↗
PubMed1997

Effects of oophorectomy and hormone replacement therapy on ophthalmic artery blood flow velocity waveforms.

Our objective was to compare ophthalmic artery flow velocity waveforms in unilateral oophorectomized patients not on hormone replacement therapy with findings in bilateral oophorectomized patients on hormone replacement therapy. Ten patients who underwent hysterectomy and unilateral oophorectomy and 10 women treated by hysterectomy and bilateral oophorectomy were studied using color and pulsed Doppler ultrasonography 1 day before and on days 7 and 28 after surgery. Serum estradiol levels were measured serially. Bilateral oophorectomy patients were given hormone replacement therapy (conjugated estrogen, 0.625 mg/day, and medroxyprogesterone acetate, 2.5 mg/day) orally starting on day 8 after surgery. The pulsatility index values of the ophthalmic artery in unilateral oophorectomy patients were 1.93 +/- 0.41, 2.10 +/- 0.26, and 1.68 +/- 0.27 for 1 day before and on days 7 and 28 after surgery, respectively. The pulsatility index values of the ophthalmic artery in bilateral oophorectomy patients were 1.99 +/- 0.39, 2.17 +/- 0.47, and 1.75 +/- 0.32 for 1 day before and on days 7 and 28 after surgery, respectively. No significant differences were found between pulsatility index values in the unilateral and bilateral oophorectomy patients in each time period. The pulsatility index values on day 28 decreased significantly compared with the findings on day 7 in both groups (P < 0.05). The serum estradiol levels were significantly reduced from 1 day before to day 7 day after surgery and were significantly elevated by day 28 after surgery (P < 0.05) in both groups of patients. No significant differences were found between the serum estradiol levels in the unilateral and bilateral oophorectomy patients in each time period. Vascular tone in the ophthalmic artery seems to change according to serum estradiol levels, a finding that may help explain some of the beneficial effects of hormone replacement therapy for bilateral oophorectomized patients.

Adult↗
PubMed1997

Assessment of cardiac sympathetic function with iodine-123-MIBG imaging in obstructive sleep apnea syndrome.

UNLABELLED: Iodine-123-MIBG imaging has been used to evaluate myocardial sympathetic function in various cardiac diseases. In patients with obstructive sleep apnea syndrome (OSAS), increased sympathetic activity has been widely recognized, as assessed by measuring the plasma concentration and urinary excretion of catecholamines and by measuring muscle sympathetic nerve activity. However, these measurements are not specific indices of cardiac sympathetic function. Therefore, this study was undertaken to assess cardiac sympathetic function in patients with OSAS using MIBG cardiac scintigraphy. METHODS: This study consisted of 11 patients (10 men, 1 woman; mean age 43 +/- 16 yr) with a diagnosis of OSAS established by polysomnography, and 8 age-matched normal control subjects (7 men, 1 woman; mean age 45 +/- 18 yr). Early (15 min) and delayed (3 hr) planar images were taken after the injection of 111 MBq of [123I]MIBG. The mean counts of the whole heart and the mediastinum were obtained to calculate heart-to-mediastinum count ratios from the early images (H/Me) and from the delayed images (H/Md) and the myocardial washout rate (WR). Eight patients were restudied after 1 mo of nasal continuous positive airway pressure treatment. RESULTS: The H/Me and H/Md ratios were significantly lower in the patients than in the control subjects (H/Me, 2.49 +/- 0.32 versus 2.84 +/- 0.34, p = 0.0207; and H/Md, 2.33 +/- 0.30 versus 3.02 +/- 0.36, p = 0.0013). The WR was higher in the patients than in the control subjects (36.2 +/- 9.0% versus 23.6 +/- 4.9%, p = 0.0022). The H/Me and H/Md ratios in the patients were significantly correlated with the apnea-hypopnea index and the degree of hypoxemia during sleep. After treatment, H/Me and H/Md remained unchanged, but WR significantly recovered (from 34.9 +/- 10.4% to 26.3 +/- 7.7%, p = 0.0357). CONCLUSION: Cardiac sympathetic function and integrity are impaired in subjects with OSAS when compared with age-matched control subjects. MIBG cardiac imaging can be helpful in evaluating cardiac involvement and efficacy of therapy in OSAS.

3-Iodobenzylguanidine↗
PubMed1997

[A surgical case of total anterior papillary muscle rupture after acute myocardial infarction].

Mitral regurgitation (MR) due to rupture of the papillary muscle is one of the most serious complications of acute myocardial infarction (AMI) as well as ventricular septal perforation and ventricular free wall rupture. We experienced a case of complete rupture of the anterior papillary muscle. A 68-year-old man experienced an episode of dyspnea. Electrocardiographic findings were consistent with postero-lateral infarction. Massive MR is present on color Doppler imaging. He was transferred to our hospital for urgent operative indication because of papillary muscle rupture due to AMI. Six hours after the onset, the operation was performed with intra-aortic balloon pump in place. The anterior papillary muscle was ruptured completely in the mid portion. He underwent a mitral valve replacement with a SJM prosthetic valve. There is a few cases with successful urgent surgery for a complete rupture of anterior papillary muscle.

Aged↗
PubMed1997

[Coronary artery bypass surgery in patients aged 75 years and older].

Coronary artery bypass grafting (CABG) has been performed for elderly patients with increasing frequency. Several studies have shown that the rate of complications and mortality in elderly patients are higher than in younger ones. This report presents results of CABG in patients over 75 years old. From January 1989 to February 1997, 604 patients underwent CABG, of whom 20 patients (3.3%) were 80-86 years old (group A) and 57 patients (9.4%) were 75-79 years old (group B). We compared these two groups with 100 younger patients (group C). Preoperative use of intraaortic balloon pumping and the emergency operation were more frequent in patients of group A (emergency 45%, IABP 20%). And the proportion of the no blood transfusion procedures was lower in elderly patients (group A 20%, group B 18%, group C 82%). The number of grafts per patient (group A 2.45 +/- 0.62, group B 2.2 +/- 0.6, group C 3.2 +/- 0.6) and the number of arterial grafts (group A 1.25 +/- 0.62, group B 1.25 +/- 0.66, group C 2.1 +/- 0.53) were different between the groups. But CABG in elderly patients was performed with low hospital mortality (group A 0%, group B 0.18%) and significant symptomatic benefit. We conclude that CABG can be performed in elderly patients with acceptable mortality and acceptable quality of life, so patients should not denied operation because of an advanced age.

Adult↗
PubMed1997

Kidney as an important metabolic organ for recombinant human insulin-like growth factor-I.

To investigate the kidney as a metabolic organ of recombinant human insulin-like growth factor-I (rhIGF-I), a single chain polypeptide consisting of 70 amino acids, the renal extraction and urinary excretion of rhIGF-I were examined in rats. The distribution of rhIGF-I after subcutaneous administration and the degradation in various tissue homogenates were also studied to evaluate the contributions of the other tissues to its metabolism. Although potent enzymes capable of degrading rhIGF-I exist in other tissues, no other organ except the kidney seemed to play a specific role in clearing rhIGF-I from the systemic circulation.

Animals↗
PubMed1997

[A case of an adult patient of tetralogy of Fallot having malignant hyperthermia during surgery].

An episode of malignant hyperthermia occurring in a 42-year-old man undergoing hypothermic cardiopulmonary bypass is reported. Malignant hyperthermia is a syndrome initiated by a hypermetabolic state of skeletal muscle. A patient presented for correction of an acyanotic tetralogy of Fallot. The coincidental usage of hypothermic cardiopulmonary bypass obscured the classical presenting sings and symptoms of the malignant hyperthermia. And the disease of tetralogy of Fallot made the syndrome difficult to manage. Although the clinical diagnosis of malignant hyperthermia is difficult to be confirmed, when it is suspected, it is prudent for the case to be initially treated as malignant hyperthermia.

Adult↗
PubMed1997

Tissue distribution kinetics of a new nonsteroidal 5 alpha-reductase [correction of 5 A-reductase] inhibitor, 4-[3-[3-[bis(4-isobutylphenyl)methylamino]benzoyl]-1H-indol-1-YL ]-butyric acid, in rats.

The disposition of a new nonsteroidal 5alpha-reductase inhibitor, 4-[3-[3-[bis(4-isobutylphenyl)methylamino]benzoyl]-1H-indol-1-yl]-butyric acid (FK143), was investigated in rats. After intravenous administration of FK143 at 1 and 5 mg/kg, total body clearance, elimination half-life, and volume of distribution at steady-state were, respectively, 6.96 and 8.76 ml/min/kg, 10.31 and 9.83 hr, and 4.11 and 3.33 liters/kg. There were no essential differences between the two doses in any parameters. The serum protein binding in vitro was very high (>99%). The unidirectional uptake clearance (CL1) to 13 tissues was determined by integration plot until 10 min after intravenous administration of 1 mg/kg. CL1 values were much smaller than blood flow rate in all tissues, including the prostate, the target organ, indicating that FK143 was transported from blood to tissues by a membrane-limited process. Since the elimination rates of FK143 from the liver, kidney, lung, epididymis, seminal vesicle, and prostate were slower than from the blood, the efflux rate constant (k2) and rate constants at a binding compartment (k3 and k4) were assumed in the pharmacokinetic model. A correlation was found between the binding potential of binding compartment (k3/k4) and V(max) of steroid 5alpha-reductase, the target enzyme, suggesting that the levels of 5alpha-reductase activity or that of associated substances are a primary determinant of the specific binding of FK143 in these tissues.

5-alpha Reductase Inhibitors↗
PubMed1997

[Case report of successful treatment of patent ductus arteriosus with severe pulmonary hypertension in an adult].

A 40-year-old man was diagnosed as having PDA with severe PH by cardiac catheterization. We decided that surgery was indicated on the basis of 100% oxygen inhalation test. After 100% oxygen inhalation, left to right shunt changed from 37.8% to 61.5%, Qp/Qs changed from 1.43 to 2.60, and PVR changed from 1,199 dyne/sec/cm5 to 237 dyne/sec/cm5. We decided to perform surgery. Under extracorporeal circulation, PDA was safely closed by triple ligation and was directly closed after pulmonary arteriotomy. The postoperative course was uneventful. Severe PH was greatly improved, pulmonary artery pressure recovering to the normal range, by administering PGE1, prostacyclin (PGI2), and nitroglycerin.

Adult↗
PubMed1997

Water channel AQP1, 3, and 4 in the human peritoneum and peritoneal dialysate.

To clarify the mechanism of water transport driven by osmotic gradient through "ultrasmall pores" in the peritoneum, we tried to identify water channels in the peritoneum and cells in the peritoneal dialysate. Peritoneum was surgically excised from uremic patients at the insertion or removal of a catheter. Sediment was collected from 2 L of peritoneal dialysate by centrifugation at 1500 rpm. RNA was extracted and amplified by reverse transcription-polymerase chain reaction (RT-PCR). Contamination of reticulocytes was tested by the presence of ankyrin mRNA. Peritoneal tissue expressed aquaporin (AQP) 1, 3, and 4 (AQP1 > 3 > 4). Sediment of dialysate expressed mRNA of AQP1 and AQP3 (AQP1 > AQP3). The sample did not express ankyrin mRNA, indicating that the AQP1 in the sediment did not originate from reticulocytes. These data indicate that aquaporins are present in the peritoneum and might participate in water transport. Further quantitative analysis of aquaporin messages in the dialysate might clarify the pathogenesis of water removal failure.

Ankyrins↗
PubMed1997

Myocardial kinetics of iodine-123-BMIPP in canine myocardium after regional ischemia and reperfusion: implications for clinical SPECT.

UNLABELLED: To evaluate the clinical utility of 123I-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) for ischemic heart disease, we investigated the metabolic fate of 123I-BMIPP in canine models with mild and severe ischemia and evaluated the clinical utility of this tracer. METHODS: Using open-chest dogs under anesthesia, we assembled a system that would release all the blood from the great cardiac vein without recirculation, if necessary. After injection of BMIPP into the left anterior descending coronary artery, blood samplings from cardiac vein and abdominal aorta were performed for 10-min ischemia (mild ischemia, five dogs) and 30-min ischemia (severe ischemia, six dogs), after reperfusion and for normal controls (six dogs). The catabolites of BMIPP, including backdiffusion of nonmetabolized BMIPP, were evaluated using high-performance liquid chromatography. RESULTS: Although the rapid extraction of BMIPP from the plasma into the myocardium and the subsequent retention were unchanged among three groups, the early washout (at 8 min) of radioactivity significantly increased (from 50% +/- 13% to 61% +/- 8%; p < 0.05) in severe ischemia. The metabolites from the myocardium consisted of backdiffusion of nonmetabolized BMIPP and alpha-oxidation, intermediate-oxidation and full-oxidation metabolites. For mild ischemia, these values were not significantly changed from the normal control, although the respective proportions of metabolites showed some variation. Lactate production after reperfusion on mild ischemia, which indicates the severity of ischemia, was closely correlated with the level of backdiffusion of BMIPP (r = -0.92) and the full-oxidation metabolite (r = 0.78). On the other hand, for severe ischemia, the level of backdiffusion of nonmetabolized BMIPP increased (from 25.1% +/- 8.0% to 34.7% +/- 8.7%; p < 0.05), and the full-oxidation metabolites decreased (from 21.4% +/- 10.9% to 14.8% +/- 7.3%). CONCLUSION: The metabolism of BMIPP was closely associated with the severity of myocardial ischemia. Thus, 123I-BMIPP might be a promising and sensitive radiopharmaceutical for the evaluation of ischemic heart disease.

Animals↗
PubMed1996

Noninvasive assessment of myocardial viability by positron emission tomography with 11C acetate in patients with old myocardial infarction. Usefulness of low-dose dobutamine infusion.

BACKGROUND: When patients with severely depressed left ventricular function are treated, it is crucial to know in advance how much functional recovery is expected from coronary revascularization. METHODS AND RESULTS: We compared the results of 11C acetate positron emission tomography (PET) with dobutamine infusion with changes in regional wall motion evaluated by left ventriculography in 28 patients with old Q-wave anterior myocardial infarctions. Dysfunctional but viable myocardium (group A, n = 13) was separated from nonviable myocardium (group B, n = 15) by echocardiographic assessments of regional wall motion before and after successful coronary revascularization. 11C acetate PET was performed to characterize normalized myocardial blood flow and oxidative metabolism (the clearance rate constant, k mono). While the baseline k monos of the infarct areas of the two groups were different with overlap, the responses to dobutamine infusion were directionally different. In addition, relative perfusion by 11C acetate PET could predict recovery of left ventricular function as well as or better than dobutamine 11C acetate kinetics. The extent of the increase in k monos of the infarct area with dobutamine infusion correlated well (P < .01) with the degree of the increase in the percentage of systolic segment shortening in the infarct area (left ventriculography) after coronary revascularization. CONCLUSIONS: 11C acetate PET with dobutamine infusion can predict not only the reversibility of dysfunctioning myocardium after coronary revascularization but also the extent of improvement of regional wall motion in patients with old Q-wave infarction.

Acetates↗