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H Terada

Publications and source records attributed to H Terada.

At least 127 records · Page 7Linked to original sources
PubMed1995

[Transesophageal echocardiographic evaluation of the effect of isoflurane on cardiac systolic and diastolic function].

In this study, we used transesophageal echocardiography to investigate the effect of isoflurane (0.0, 0.3, 0.5, and 1.0%) on cardiac systolic and diastolic function in 10 adult patients without ischemic heart disease. Concerning systolic function, fractional shortening, stroke volume, and cardiac output showed dose-dependent, significant increases at 1% isoflurane. Concerning diastolic function, left ventricular flow velocity and pulmonary vein flow velocity were measured but the peak velocities were unchanged at each concentration of isoflurane. In conclusion, isoflurane at concentrations used in the current study is unlikely to cause significant myocardial depression in normal adults.

Aged↗
PubMed1995

Nucleotide sequence of the 5'-flanking region of the rat type II hexokinase gene.

In a previous study, we found that the steady state transcript level of type II hexokinase was specifically and remarkably elevated in rat hepatoma AH130 cells. To determine the molecular mechanism of transcriptional control of the type II hexokinase gene, we examined the nucleotide sequence of its 5'-flanking region and analyzed putative transcription factor binding sites. We also examined the type II hexokinase promoter activity by the chloramphenicol acetyltransferase (CAT) assay.

Amino Acid Sequence↗
PubMed1995

Leukemic transformation of polycythemia vera and essential thrombocythemia possibly associated with an alkylating agent.

BACKGROUND: Leukemic transformation of polycythemia vera (PV) and essential thrombocythemia (ET) is influenced by the therapeutic modalities used. A high incidence of leukemic transformation was found among patients with PV or ET treated with an alkylating agent, carboquone (CQ). The study was conducted to assess the causal relationship between CQ and leukemic transformation of PV and ET. METHOD: Twenty-seven patients with PV and 29 with ET diagnosed from January 1975 to August 1993 and whose clinical course could be followed comprised the members of this retrospective study. The patients were examined for the treatment administered, hematologic data, vascular complications, malignancies including leukemia, and eventual outcome. RESULTS: Eighteen patients with PV and 16 with ET were treated with CQ. The follow-up was 51-209 months for patients with PV and 28-176 months for those with ET. Three patients with PV (17% of those treated with CQ) and 5 with ET (31% of those treated with CQ) had subsequent transformation to acute leukemia. The median period until transformation of patients with PV was 94 months, whereas the median follow-up of patients without transformation was 146 months (P < 0.01). The median total days of CQ administration and the median total dose of CQ were 2022 days and 1226 mg, respectively, for the patients with transformation and 1051 days (P < 0.05) and 435 mg (P < 0.01), respectively, for those without transformation. Likewise, the median follow-ups for patients with ET with or without transformation were 130 and 90 months, respectively; the difference was insignificant. The median total days of CQ administration and the median total dose of CQ were 2075 days and 1019 mg, respectively, for patients with transformation and 571 days (P < 0.05) and 231 mg (P < 0.01), respectively, for those without transformation. These observations suggest that CQ may be involved in the leukemic transformation of PV and ET. The subtypes of leukemia transformed from PV corresponded to M2 in two patients and to M4 in one. All five patients with ET were found to have megakaryoblastic features at transformation, and three were diagnosed as having leukemic subtype M7. Chromosomal abnormalities were found in all five patients (two PV and three ET) examined after leukemic transformation, showing multiple and complex abnormalities in four. CONCLUSION: Showing that both the total days of CQ administration and the total dose of CQ were larger for patients with PV or ET whose disease subsequently transformed to leukemia, with this study, a possible causal role of CQ in leukemic transformation of PV and ET is suggested.

Adult↗
PubMed1995

Site of action of the local anesthetic tetracaine in a phosphatidylcholine bilayer with incorporated cardiolipin.

Tetracaine (TTC) increases the permeability of phospholipid liposomal membranes to water, and this increase is reduced by the incorporation of cardiolipin into the membranes. We examined the molecular interaction of a phospholipid with the TTC cation in egg-yolk phosphatidylcholine (EyPC) liposomal membranes with incorporated bovine heart cardiolipin (BhCL) by IR spectroscopy and by determination of partitioning and the pKa of membrane-bound TTC. The IR spectra indicated that TTC shifted the stretching band of the BhCL PO2- group, a potential site of hydration in the bilayer, to a lower frequency but did not shift that of EyPC. TTC intercalated into the BhCL bilayer shifted its aromatic C-N stretching band to a lower frequency. One molecule of TTC was found to bind approximately five molecules of EyPC, and the incorporation of negatively charged BhCL into EyPC membranes increased the degree of binding of TTC to the bilayer membranes. The pKa values of TTC bound to membranes were determined as 7.7, 9.4, and 10.2 for EyPC membranes, EyPC membranes containing 50 mol % BhCL, and BhCL membranes, respectively, whereas that in an aqueous 10-mM NaCl solution was 8.5, as it was dependent on the manner of binding. The IR data together with the partitioning and the pKa data suggested differences between the actions of the TTC cation on negatively charged BhCL and on neutrally charged EyPC polar groups in the region close to the aqueous interface of the lipid bilayer.

Animals↗
PubMed1995

The fourth armadillo repeat of plakoglobin (gamma-catenin) is required for its high affinity binding to the cytoplasmic domains of E-cadherin and desmosomal cadherin Dsg2, and the tumor suppressor APC protein.

Plakoglobin is a member of a protein family with a repeated amino acid motif, the armadillo repeat, and is a cytoplasmic protein found in both adherens junctions and desmosomes. Plakoglobin has been shown to form distinct complexes with cadherins or desmosomal cadherins. Also, plakoglobin has been shown to complex with APC, the tumor suppressor gene product. Recently we isolated a cDNA clone encoding plakoglobin lacking the fourth armadillo repeat of the original 13-repeat protein [Ozawa et al. (1995) J. Biochem. 118, 836-840]. In this study, we established an in vitro assay system to study the molecular interaction of plakoglobin with cadherins, the APC gene product, and alpha-catenin. Establishment of the system and cloning of an alternate form of plakoglobin cDNA allowed us to examine the biological activity of plakoglobin lacking the fourth armadillo repeat. Experiments with the bacterially expressed 12-repeat plakoglobin revealed that the protein binds to E-cadherin, desmoglein (Dsg2), and APC with lower affinity than the 13-repeat form does. Consistent with the observation that the affinity of alpha-catenin for these two alternate forms was similar, we found amino acid residues 104 to 145 of plakoglobin, the residues present in both isoforms, are sufficient for its binding to alpha-catenin.

Adenomatous Polyposis Coli Protein↗
PubMed1995

Na+/H+ and Na+/Ca2+ exchange in regulation of [Na+]i and [Ca2+]i during metabolic inhibition.

The relationships among intracellular Na+ and Ca2+ concentrations ([Na+]i and [Ca2+]i, respectively) and cell morphology were investigated during metabolic inhibition (MI) in isolated guinea pig myocytes. [Na+]i and [Ca2+]i were measured using the fluorescent indicators, Na(+)-binding benzofuran isophthalate and fluo 3. During the initial 20 min of MI, [Na+]i increased from 6.2 +/- 0.5 to 18.6 +/- 1.6 mM (n = 31), whereas [Ca2+]i, expressed as the percent change of fluo 3 fluorescence, remained at the low level. In the following 30 min, 94% of the cells developed contracture, and [Ca2+]i began to increase after cells had contracted (167 +/- 14% at 50 min). The level of [Ca2+]i during MI was lower than that during 500 microM strophanthidin perfusion. The increase in [Na+]i was not affected by 10 microM tetrodotoxin but was suppressed by 1 microM hexamethylene amiloride (HMA). The application of 10 mM glucose from the start of MI prevented both the increase in [Na+]i and cell contracture. However, the addition of glucose after 20 min of MI [energy repletion (ER)] led to a dramatic increase in [Ca2+]i (442 +/- 72% at 50 min, n = 31), and 84% of the cells developed contracture. The increase in [Ca2+]i and the cell contracture were suppressed by HMA or Ca(2+)-free solution. Intracellular pH decreased from 7.23 +/- 0.07 to 6.95 +/- 0.09 during MI but did not change after ER (6.90 +/- 0.11 at 35 min, n = 9). These findings suggested that during MI 1) [Na+]i increased by both the activated Na+ influx via Na+/H+ exchange and the suppressed Na+ extrusion via the Na+/K+ pump, 2) Na+/Ca2+ exchange was inhibited by energy depletion and intracellular acidosis, and 3) cell contracture was not related to Ca2+ overload but was related to rigor due to energy depletion.

Amiloride↗
PubMed1995

Stimulation of insulin action and stabilization of cell membrane in 3T3-L1 cells by glycinin acidic subunit A1a.

Glycinin acidic subunit A1a and its trypsinized product (A1a/Try) were found to potentiate insulin-mediated antilipolysis antagonized to isoproterenol in 3T3-L1 preadipocytes and adipocytes. A1a and A1a/Try protected 3T3-L1 preadipocytes from the cytotoxic action of trypan blue. Furthermore, the oxygen consumption in rat liver mitochondria that was accelerated during incubation, which implies an increase in the permeability of the inner membrane, was suppressed by the addition of A1a and A1a/Try. On the other hand, the chymotryptic product of A1a did not show such effects. These results suggest that specific amino acid alignment is required for the functions of A1a and that the insulin-stimulating action of A1a and A1a/Try is closely correlated with their stabilizing effect on cell membranes.

3T3 Cells↗
PubMed1995

Intracellular sodium concentration in diabetic rat ventricular myocytes.

We measured intracellular NA+ concentration ([Na+]i) of diabetic rat ventricular myocytes using sodium-binding benzofuran isophthalate (SBFI). We used diabetic rats at 8 weeks after the injection of streptozotocin (45 mg/kg i.v.). The level of [Na+]i during the control perfusion was significantly lower in diabetic myocytes than that in normal myocytes (9.2 +/- 0.4 mM v.s. 12.0 +/- 0.3 mM, p < 0.01). After the 40 min perfusion of 1 microM hexamethylene amiloride (HMA), [Na+]i decreased significantly in both groups. However, there was no difference in [Na+]i between the two groups after the perfusion of HMA. It was suggested that the lower [Na+]i in diabetic myocytes could be due to the decreased activity of Na+/H+ exchange system.

Amiloride↗
PubMed1995

[A case of male infertility with a chromosomal abnormality of 45, X/46, X + mar].

A 28-year-old man visited our hospital with a complaint of male infertility. His development was normal with body size of 169.5 cm in height and muscular type. His beard and axillary and pubic hairs were male type. The penis and scrotum were also normal, but testes were small (8 ml, bilateral). Semen analysis revealed azoospermia. Serum luteinizing hormone (LH) and testosterone levels are within normal range but follicle stimulating hormone (FSH) was moderately elevated. Testicular biopsy specimen showed severely hyalinized seminiferous tubuli, incarceration of basement membrane and hyperplasia of Leydig cells. Johnsen's score count was two. Chromosomal analysis revealed a mosaic type of 45, X/46, X + mar. We tried to confirm the existence of sex-determining region of the Y chromosome (SRY) by the DNA analysis. It was shown that SRY on genomic DNA fragment. This marker chromosome may be translocated to a fragment of the short arm of Y chromosome.

Adult↗
PubMed1995

[Effect of a newly developed corneal storage medium on corneal endothelium--morphological study by scanning electron microscopy].

We compared the effects on corneal endothelium of the new storage mediums I and II with those of OPTISOL. Storage mediums I and II had the same formula, i.e., 0.1% hyaluronic acid, except for the concentration of basic medium TC-199. I contained 70% of the TC-199 concentration of OPTISOL and II contained 80%. Rabbit corneas were stored in storage mediums I and II for 3, 7, 10 and 14 days and in OPTISOL for 7, 10 and 14 days at 4 degrees C. After the 3-day storage period, endothelial cells were preserved in good condition. After the 7-day storage period, medium I showed better preservative ability in endothelial configuration than the other two storage media. Medium II and OPTISOL showed a similar storage potential morphologically. With increasing storage time, endothelial cells showed an irregular surface and a less defined cellular edge in both media II and OPTISOL.

Animals↗
PubMed1995

[Changes in neuropsychological functions following cardiovascular surgery].

This study was designed to elucidate if there is a potential hazard of developing neuropsychological deterioration after major cardiovascular surgery. Neuropsychological functions were studied in 49 patients before and after cardiac (coronary artery bypass, cardiac valve replacement, etc.) and thoracic aortic surgery (aortic aneurysm). Neuropsychological examinations using 5 batteries (Mini-Mental State Examination, Cross Cultural Cognitive Examination, Miyake's Verbal Memory Test, Benton Visual Retention Test and Wisconsin Card Sorting Test) were performed before surgery and subsequently at 3 weeks and 8 months after. Twenty-five of 49 patients (51%) showed a significant deterioration at least in one of the test batteries. There was no significant relation between age or educational levels and post-surgical impairment of cognitive function. The impairment of cognitive function was found mainly in the "memory function". Follow up examinations were carried out on 31 of the 49 patients 8 months after surgery. Among these patients, 13 patients did not show any changes in cognitive function throughout the study period. Eleven of the 16 patients who developed a decrease in cognitive function for a certain period after surgery (3 weeks), recovered to the same level at the follow-up examination that it was prior to the surgery. Cognitive function in five patients did not improve and remained at the decreased level. The other two patients whose function was normal at the first post-surgical examination, were found to have developed impairment of cognitive function at the follow up. Although the patients had some deficits on their neuropsychological function, they scarcely complained about any problems in their daily life.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Quantitative changes in cerebral blood flow of Shy-Drager syndrome induced by upright position: assessment by 99mTc-HMPAO].

We assessed orthostatic changes of cerebral blood flow (CBF) in 4 patients with Shy-Drager syndrome. Brain perfusion index (BPI) was measured by 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO). Cerebral angiography using aortic time-activity curve as an input function BPI values in supine and upright positions in Shy-Drager syndrome were compared with those in 2 cerebrovascular disease patients without orthostatic hypotension. BPI values in the upright position were significantly decreased in patients with Shy-Drager syndrome as compared with these in the supine position. No significant decrease in BPI was noted in the patients without orthostatic hypotension. These results suggest that the BPI measurement by 99mTc-HMPAO cerebral angiography is useful for the noninvasive evaluation of the orthostatic changes of the CBF.

Adult↗