Biomedical subjects

H Terada

Publications and source records attributed to H Terada.

At least 55 records · Page 3Linked to original sources

PubMed2000

Prolongation of the QT interval and ventricular tachycardia in patients treated with arsenic trioxide for acute promyelocytic leukemia.

BACKGROUND: Recently, arsenic trioxide has increasingly been used for relapsed acute promyelocytic leukemia. However, it is known to have several adverse effects, including acute cardiac toxicities. OBJECTIVE: To determine cardiac toxicities resulting from arsenic trioxide therapy in patients with relapsed or refractory acute promyelocytic leukemia. DESIGN: Phase II clinical prospective cohort study. SETTING: A university hospital in Hamamatsu, Japan. PATIENTS: 8 patients with relapsed acute promyelocytic leukemia. INTERVENTION: Arsenic trioxide, 0.15 mg/kg of body weight, administered daily by 2-hour infusion for a maximum of 60 days. MEASUREMENTS: Continuous monitoring with ambulatory electrocardiography. RESULTS: Five patients (63%) achieved complete remission. During induction therapy with arsenic trioxide, prolonged QT intervals were observed in all patients. Ventricular premature contractions were noticed during 8 of 12 courses of therapy. Four patients developed nonsustained ventricular tachycardia and required treatment with antiarrhythmic agents. CONCLUSIONS: Cardiac toxicity occurs during arsenic trioxide therapy in patients with acute promyelocytic leukemia. Such patients should be monitored for prolonged QT intervals and ventricular arrhythmia.

Adult↗

PubMed2000

Novel expression of equivocal messages containing both regions of choline/ethanolamine kinase and muscle type carnitine palmitoyltransferase I.

For characterization of the detailed gene structure of human muscle type carnitine palmitoyltransferase I (M-CPTI), we analyzed the 5'-upstream region of the M-CPTI transcripts. As a result, we found a cDNA clone containing a nucleotide sequence unexpected from the reported M-CPTI gene structure in the upstream region of its 5' end. Comparison of this nucleotide sequence with that of genomic DNA showed that this sequence was derived from the 3'-untranslated region of the gene encoding choline/ethanolamine kinase-beta (CK/EK-beta) located upstream of the M-CPTI gene. Southern blot analysis showed that there was no other region homologous to the CK/EK-beta gene in the whole human genome. Thus, the overlapping transcript was concluded to be produced from the functional genes of CK/EK-beta and M-CPTI. Furthermore, cDNAs containing both exons of these genes were detected by the polymerase chain reaction using the cDNA of human heart M-CPTI obtained by specific reverse transcription from its 3'-untranslated region as a template. From these results, the production and organization of these overlapping transcripts are discussed.

3' Untranslated Regions↗

PubMed2000

Specific elevation of transcript levels of particular protein subtypes induced in brown adipose tissue by cold exposure.

To understand the difference in metabolic flow in rat brown adipose tissue (BAT) from that in white adipose tissue (WAT) at the molecular level, we examined the steady-state transcript levels of 39 proteins in both adipose tissues with and without cold exposure by Northern blot analysis. In addition to the transcript levels of uncoupling protein isoforms, those of proteins involved in the transport and catabolism of fatty acids and glucose in BAT were elevated by cold exposure, suggesting the stimulation of utilization of fatty acids and glucose as fuels in BAT. As to these changes, the muscle-type subtypes were remarkable; and therefore, they were suggested to be responsible for the cold exposure-induced acceleration of energy expenditure in BAT. Furthermore, of the isoforms of beta-adrenergic receptor (beta-AR) and CCAAT enhancer binding protein (C/EBP), transcript levels of beta(1)-AR and C/EBPbeta in BAT were increased by the cold exposure. Possible roles of these proteins in energy metabolism in BAT were discussed.

Adipose Tissue, Brown↗

PubMed2000

KB-R7943 block of Ca(2+) influx via Na(+)/Ca(2+) exchange does not alter twitches or glycoside inotropy but prevents Ca(2+) overload in rat ventricular myocytes.

BACKGROUND: The Na(+)/Ca(2+) exchange (NCX) extrudes Ca(2+) from cardiac myocytes, but it can also mediate Ca(2+) influx, load the sarcoplasmic reticulum with Ca(2+), and trigger Ca(2+) release from the sarcoplasmic reticulum. In ischemia/reperfusion or digitalis toxicity, increased levels of intracellular [Na(+)] ([Na(+)](i)) may raise levels of intracellular [Ca(2+)] ([Ca(2+)](i)) via NCX, leading to cell injury and arrhythmia. METHODS AND RESULTS: We used KB-R7943 (KBR) to selectively block Ca(2+) influx via NCX to study the role of NCX-mediated Ca(2+) influx in intact rat ventricular myocytes. Removing extracellular Na(+) caused [Ca(2+)](i) to rise, due to Ca(2+) influx via NCX, and this was blocked by 90% with 5 micromol/L KBR. However, KBR did not alter [Ca(2+)](i) decline due to NCX. Thus, we used 5 micromol/L KBR to selectively block Ca(2+) entry but not efflux via NCX. Under control conditions, 5 micromol/L KBR did not alter steady-state twitches, Ca(2+) transients, Ca(2+) load in the sarcoplasmic reticulum, or rest potentiation, but it did prolong the late low plateau of the rat action potential. When Na(+)/K(+) ATPase was inhibited by strophanthidin, KBR reduced diastolic [Ca(2+)](i) and abolished the spontaneous Ca(2+) oscillations, but it did not prevent inotropy. CONCLUSIONS: In rat ventricular myocytes, Ca(2+) influx via NCX is not important for normal excitation-contraction coupling. Furthermore, the inhibition of Ca(2+) efflux alone (as [Na(+)](i) rises) may be sufficient to cause glycoside inotropy. In contrast, Ca(2+) overload and spontaneous activity at high [Na(+)](i) was blocked by KBR, suggesting that net Ca(2+) influx (not merely reduced efflux) via NCX is involved in potentially arrhythmogenic Ca(2+) overload.

Animals↗

PubMed2000

Polymorphism in the promoter region of the alpha(2A)-adrenergic receptor gene and panic disorders.

alpha(2)-Adrenergic receptors have been thought to play a crucial role in the etiology or treatment of panic disorders. Polymorphism(s) in the promoter region of the alpha(2) receptor may affect gene expression and be associated with panic disorders. We studied the polymorphism of the alpha(2A) receptor gene at position -1291 reported by Lario et al. (Lario, S., Calls, J., Cases, A., Oriola, J., Torras, A., Rivera, F., 1997. Short repeat on DNA marker at candidate locus. MspI identifies a biallelic polymorphism in the promoter region of the alpha(2A)-adrenergic receptor gene. Clinical Genetics 51, 129-130.) in 114 healthy control subjects and 55 patients with panic disorders. There was no statistically significant difference between controls and patients in either genotype or allele frequency. Our results suggest there is no association between this polymorphism in the promoter region of the alpha(2A) receptor gene and panic disorders.

Adult↗

PubMed2000

Clinical significance of ventilation/perfusion scans in collagen disease patients.

UNLABELLED: The purpose of this study was to detect disturbances in pulmonary circulation in collagen disease patients by means of a non-invasive technique. METHODS: Ventilation/perfusion scans with 133Xe gas and 99mTc-macroaggregated albumin (MAA) were performed in 109 patients with various collagen diseases. Functional images of V, Vol, Q and V/Q ratio were obtained at total lung capacity. Wash-out time was calculated from the wash-out curve. Whole body scans were performed in 65 patients to evaluate intra-pulmonary shunts. RESULTS: Increased V/Q areas were observed in 74 patients (67.9%), suggesting some impairment of pulmonary perfusion. Decreased perfusion, probably due to vasculitis or intravascular microcoagulation, was observed often, even in patients without pulmonary fibrosis. Shunt ratios over 10% were observed in 8 of the 65 patients (12.3%), indicating formation of PA-PV shunts secondary to peripheral vascular impairment. Wash-out time was prolonged in 37 patients (33.9%), shortened in 18 (16.5%), and within the normal range in 54 (49.6%). The prolonged and normal wash-out times in the patients with pulmonary fibrosis may represent obstructive changes in the small airways superimposed on the fibrosis. CONCLUSION: Ventilation/perfusion scans are a very useful tool for evaluating collagen lung diseases, and they might contribute to treatment decisions for the patients.

Collagen Diseases↗

PubMed2000

Total arch replacement using aortic arch branched grafts with the aid of antegrade selective cerebral perfusion.

BACKGROUND: We report our clinical experience with total arch replacement using aortic arch branched graft in an attempt to determine the independent predictors of both in-hospital mortality and neurologic outcome. METHODS: We studied 220 consecutive patients who underwent total arch replacement using aortic arch branched graft between May 1990 and June 1999. All operations were performed with the aid of hypothermic extracorporeal circulation, antegrade selective cerebral perfusion, and open distal anastomosis. RESULTS: The overall in-hospital mortality rate was 12.7%. Multivariable analysis showed independent determinants of in-hospital mortality to be chronic renal failure, long pump time, participation in early series, and shock. Postoperative permanent neurologic dysfunction was 3.3%. On multivariable analysis, old cerebral infarct and pump time were independent determinants of permanent neurologic dysfunction. The selective cerebral perfusion time had no significant influence on in-hospital mortality or neurologic outcome. The 5-year survival rate including in-hospital deaths was 79% +/- 6%. CONCLUSIONS: Selective cerebral perfusion allows increased ease of performance of total arch replacement, a complex and time-consuming procedure, and helps reduce periprocedural mortality and morbidity in patients with aortic arch aneurysm and those with acute aortic dissection.

Adolescent↗

PubMed2000

Extended total arch replacement for acute type a aortic dissection: experience with seventy patients.

OBJECTIVE: We sought to report the clinical experience with extended total arch replacement for acute type A aortic dissection and to determine the factors that influence early mortality, late survival, and late reoperation. METHODS: Between December 1988 and August 1998, 70 patients underwent emergency graft replacement of both the ascending aorta and the total aortic arch for acute type A aortic dissection. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and open distal anastomosis. Concomitant procedures included aortic valve resuspension in 18 patients, composite graft replacement in 10 patients, and coronary artery bypass grafting in 5 patients. RESULTS: The early mortality rate was 16% (11 of 70 patients). Multivariable analysis showed that renal-mesenteric ischemia and coronary artery bypass grafting were independent determinants for early death. Survival rates at 3 and 5 years postoperatively, including the early deaths, were 75% +/- 5% and 73% +/- 6%, respectively. Multivariable analysis showed that renal-mesenteric ischemia and en bloc repair were independent determinants for late death. Freedom from reoperation was 91% +/- 4% and 77% +/- 8% at 3 and 5 years, respectively. Multivariable analysis showed that anastomotic leakage was the only significant determinant for late reoperation. CONCLUSIONS: Extended total arch replacement for acute type A aortic dissection could be justified in properly selected patients.

Acute Disease↗

PubMed2000

Characterization of porin isoforms expressed in tumor cells.

Mitochondria from malignant tumor cell lines show a higher capability for hexokinase binding than those from normal liver. To explore possible differences in hexokinase binding sites of mitochondria between tumor cells and normal liver, we characterized porin isoforms expressed in tumor cells. Cloning experiments on the three porin isoforms, VDAC1, VDAC2 and VDAC3 from malignant tumor cell line AH130 clearly showed that their primary structures were completely identical to those of the corresponding VDACs of normal liver cells. Possible expression of the fourth porin isoform in AH130 cells was excluded by degenerate primer-based RT-PCR. However, the transcript levels of the three VDAC isoforms in AH130 cells were significantly higher than those in normal liver. These results suggest that the high hexokinase-binding capability of malignant tumor cell mitochondria was not due to any structural difference, but due to a quantitative difference in binding sites.

Alternative Splicing↗

PubMed2000

Surgical treatment of recurrent abdominal aortic aneurysm in a patient with systemic lupus erythematosus.

Reports of true abdominal aortic aneurysms (AAAS), especially those due to severe inflammation, in patients with systemic lupus erythematosus (SLE) are very few in number. However, we had the experience of surgically treating a recurrent AAA due to severe inflammation found in a patient with SLE. The recurrence took place after an earlier operation for an infrarenal AAA and involved the left renal artery. In both situations, the previous infrarenal aaa and the recurrence, the aneurysms demonstrated more rapid growth and more irregularities in shape. Etiology of the AAA might be a combination of Takayasu's arteritis and SLE because the two entities appeared to have overlapped.

Adult↗

PubMed2000

Development of surgical confocal scanning microscope for intra-operative imaging of brain tumors using near infrared fluorescence: technical note.

We developed a confocal laser scanning microscope for intra-operative imaging of brain tumors using near infrared fluorescence. The quality of near infrared images of Indocyanine Green (ICG) was compared with the surgical confocal scanning (SCS) microscope and a conventional charge-coupled device (CCD) camera; we compared images of a tube filled with ICG, which was located in the mouse brain. Compared to the CCD camera, the SCS microscope could obtain a more precise image of ICG fluorescence through the brain tissue. In addition, the SCS microscope could image ICG fluorescence clearly in a relatively light room because of elimination of stray light, while the CCD camera required high darkness to obtain ICG images. The present SCS microscope can give useful intra-operative imaging of brain tumors, particularly detection of residual tumor tissues that extend into normal brain tissues.

Animals↗

PubMed2000

Irreversible extrusion of the first loop facing the matrix of the bovine heart mitochondrial ADP/ATP carrier by labeling the Cys(56) residue with the SH-reagent methyl methanethiosulfonate.

The effect of the SH-reagent methyl methanethiosulfonate (MMTS) on the ADP/ATP carrier of bovine heart mitochondria was studied under various conditions. MMTS labeled predominately Cys(56) in the first loop facing the matrix (loop M1), and the labeling inhibited ADP transport via the carrier. The transport inhibition was found to be due to fixation of the carrier in the m-state conformation. MMTS labeling was suggested not to affect ADP binding to its major binding site. These features were the same as those of another commonly used SH-reagent, N-ethylmaleimide (NEM). Although the van der Waals volume of the non-hydrogen-bondable methylthio group of MMTS is much smaller than that of the ethylsuccinimide group of NEM, modification of Cys(56) inhibited the interconversion between the m- and c-state conformation. The mechanism by which MMTS inhibited the transport activity is discussed in terms of stabilization of conformation of the loop M1.

Adenosine Diphosphate↗

PubMed2000

Effects of a selective inhibitor of Na+/Ca2+ exchange, KB-R7943, on reoxygenation-induced injuries in guinea pig papillary muscles.

The effects of a novel agent that is reported to selectively block Ca2+ influx by Na+/Ca2+ exchange (NCX), KB-R7943, on the reoxygenation-induced arrhythmias and the recovery of developed tension after reoxygenation, were investigated in guinea pig papillary muscles. KB-R7943 dose-dependently suppressed the contracture tension during low-sodium (21.9 mM) perfusion (23+/-8% of steady-state developed tension at 10 microM vs. 56+/-11% in control; n = 6, p<0.05), but did not change action potential and contractile parameters. During the reoxygenation period after 60-min substrate-free hypoxia, KB-R7943 (10 microM) significantly decreased the incidence of arrhythmias (44 vs. 100% in control; n = 9, p <0.05) and shortened the duration of arrhythmias (16+/-11 vs. 72+/-14 s; p<0.01). KB-R7943 (10 microM) significantly enhanced the recovery of developed tension after reoxygenation (83+/-4 vs. 69+/-3% in control; p<0.05). We conclude that KB-R7943 (10 microM) selectively inhibits the reverse mode of NCX, and that it attenuates reoxygenation-induced arrhythmic activity and prevents contractile dysfunction in guinea pig papillary muscles. These results suggest that Ca2+ influx by NCX may play a key role in reoxygenation injury.

Action Potentials↗

PubMed2000

Multivessel coronary thrombosis, acute myocardial infarction, and no reflow in a patient with essential thrombocythaemia.

Essential thrombocythaemia (ET) has been reported rarely to cause coronary thrombosis, but the management is still undefined. A 63 year old woman with multivessel coronary thrombosis, acute myocardial infarction (MI), and no reflow in reperfused coronary artery in association with ET is presented. The patient's platelet count was only moderately raised at the onset of MI, but peripheral blood smear and bone marrow evaluation revealed clumping giant platelets and numerous large hyperploid megakaryocytes. Long term prophylaxis with antiplatelet agents in patients with ET is recommended, even if the platelet count is not largely raised. Cytoreductive treatment may also be effective for secondary prevention when thrombotic complications occur.

Coronary Thrombosis↗

PubMed2000

Left atrial diverticulum associated with severe mitral regurgitation.

Diverticulum of the atrium is a rare and controversial clinical entity, and in the present case a left atrial diverticulum was associated with severe mitral regurgitation (MR). A 68-year-old female with the diagnosis of MR was referred for further cardiac evaluation. Echocardiography revealed severe MR and an accessory cavity behind an enlarged left atrium. She underwent surgical valve replacement, but excision of the diverticulum was not done because its rupture seemed unlikely. A follow-up computed tomography performed 8 months postoperatively demonstrated disappearance of the diverticulum. The etiology of this atrial diverticulum is not clear, but the patient's MR may have played a role in its development.

Aged↗

PubMed2000

Peak systolic blood pressure in exercise testing is associated with scintigraphic severity of myocardial ischemia in patients with exercise-induced ST-segment depression.

Some electrocardiographic variables, including the degree of maximal ST-segment depression (STD), may not necessarily indicate the severity of exercise-induced myocardial ischemia. The present study examined whether maximal STD correlates with the severity and extent of exercise-induced myocardial ischemia, as assessed by thallium-201 (201Tl) imaging, and which parameter of exercise testing reflects scintigraphic severity and extent in 270 patients who had a 1 mm or greater horizontal or down-sloping STD on exercise 201Tl imaging. The scintigraphic severity and extent of exercise-induced ischemia was assessed and correlated with maximal STD, number of positive leads, workload, peak heart rate, peak systolic blood pressure (SBP), rate-pressure product, chest pain and the Duke treadmill score. Most of the scintigraphic markers of the severity and extent of ischemia had significant but weak correlation with all of those parameters. Multivariate analysis demonstrated that peak SBP and the Duke treadmill score (chest pain in only simple variables model) correlated independently with scintigraphic severity and extent of ischemia. Furthermore, most of the patients with a peak SBP of 200 mmHg or more had milder and less extensive ischemia. In patients with exercise-induced STD, the scintigraphic severity and extent of ischemia may be estimated by peak SBP and the Duke treadmill score.

Aged↗

PubMed2000

A case of acute myocardial infarction associated with topical use of minoxidil (RiUP) for treatment of baldness.

A 45-year-old Japanese man with paroxysmal atrial fibrillation (AF) developed acute anteroseptal myocardial infarction (MI). He had used 1% topical minoxidil (RiUP) once a day for 4 months before the onset of MI for treatment of baldness. Coronary angiography demonstrated severe stenosis at the proximal portion of the left anterior descending coronary artery with a tilling defect. Electrocardiographic monitoring revealed paroxysmal AF and sinus bradycardia with sinus arrests, suggestive of sick sinus syndrome. Topical minoxidil is now widely used for the treatment of male pattern baldness. Although it may be difficult to relate topical use of minoxidil to myocardial ischemia, a greater awareness of its toxicity will be necessary, and patients with cardiovascular disorders should be excluded from the therapy.

Administration, Topical↗

PubMed2000

[A study on effective implementation of the Shinjuku Regional Occupational Health Center Program in Japan].

The Regional Occupational Health Center (ROHC) Program is aimed at improving occupational health services for small-scale enterprises (SSEs) with less than 50 employees. In 1993 the ROHC program began as a new policy announced by the national government, which entrusted the management to regional medical associations. The establishment of 347 ROHCs has completed in 1997. SSEs are able to use several services, such as workplace visits and health consultations at SSEs, but ROHCs have often been under-utilized. Purpose of this study was to discuss the effective implementation of ROHCs through a couple of surveys of potential and actual ROHCs users. Two surveys were conducted in the area of the Shinjuku ROHC. Survey 1: The subjects were 78 SSEs that used The Shinjuku ROHC between October 1996 and March 1999. A qualitative evaluation was carried out for 78 SSEs about users' positions, opportunities for use and kinds of consultations. Survey 2: The subjects were 50 users of the ROHC between April 1998 and March 1999. The effective response rate was 56.0%. A questionnaire survey was conducted on users' impressions before and after using the ROHC and on requests for further service. Survey 1 showed users' positions were office workers 36.5%, managers 32.0%, directors 17.0%, health nurses 9.0% and employees 3.5%, half of the users were recommend by the Labour Standards Inspection Office. The kind of consultation were on Industrial physicians, 22.9%, Occupational health control systems, 19.1% and ROHC functions, 16.8%. Survey 2 showed that almost but all users had misunderstood the ROHC's function before utilizing of its services, but many users were satisfied with the services provided. First, ROHCs need to make known their existence and the content of their services available to SSEs. Second, ROHCs have to improve their availability to SSEs. Third, ROHCs have to ensure the quality of their services to make users satisfied. And cooperation with other occupational health institutions will become important as the ROHC Program continues to develop.

Consumer Behavior↗