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D Saito

Publications and source records attributed to D Saito.

At least 37 records · Page 2Linked to original sources
PubMed2001

Relation of QT-interval variability to ventricular arrhythmias during percutaneous transluminal coronary angioplasty.

The present study investigated the role of the dispersion of QT interval in percutaneous transluminal coronary angioplasty (PTCA)-induced ventricular tachyarrhythmias. Patients with effort angina without a previous myocardial infarction (n = 22), who had single-vessel disease of the anterior descending coronary artery (LAD), underwent PTCA if the coronary lesion was 75% or more stenosed in segment 6 or 7 of the LAD. The standard 12-lead ECG was continuously recorded during the procedure. Averaged QTc and QTac intervals, where QTac was the interval from the beginning of QRS complex to the nadir of T wave corrected by Bazett's formula, did not change significantly during PTCA. Of the 22 patients, 7 showed ventricular arrhythmias during PTCA. The maximum difference (deltaQTc) and the standard deviation (QTcSD) of the corrected QT interval in the standard 12-lead ECG increased significantly during PTCA in the 7 patients with ventricular arrhythmias, whereas they decrreased in the 15 patients without ventricular arrhythmias. deltaQTac and QTacSD were not affected by PTCA regardless of ventricular arrhythmias, which shows that the increases in the variation of the ventricular repolarization process play a role in PTCA-induced ventricular arrhythmias.

Aged↗
PubMed2001

Regional myocardial function at the papillary muscle insertion site.

The importance of the mitral apparatus to the global left ventricular (LV) function has been suggested in several clinical studies. One recent study reported that chordal transsection induced an unloading of myocardium at the papillary muscle insertion site. We hypothesized that the regional response for afterloading at this site with intact mitral apparatus was different from that at the free wall. We investigated the end-systolic pressure-regional segment length relations (ESPLR) in two anterior LV sites, free wall (FREE) and the papillary muscle insertion site (PAP), during an increasing afterload by aortic occlusion in 7 anesthetized open-chest dogs. To measure the regional segment length at FREE and PAP, two sets of the pair of sonomicrometer crystals were implanted in the same midwall depth at the same circumferential hoop by using an echocardiographic guide. ESPLR both at FREE and PAP were always highly linear in a physiological range (r > or = 0.9). The slope of this relation at FREE (274 +/- 164 mmHg/mm) was significantly steeper than that at PAP (157 +/- 118 mmHg/mm) for each dog (p < 0.05). These data indicate that the regional response for afterloading at PAP loaded by chordal tension is different from that at FREE in the same heart.

Animals↗
PubMed2001

[Treatment of gastric MALT lymphoma by H. pylori eradication].

Strong evidence exists for the efficacy of H. pylori eradication in achieving gastric low-grade MALT lymphoma (L-MALT) regression when the bacteria present. Besides histological evaluation, the appearance of endoscopic finding such as 'discolored mucosa-like atrophy' after treatment may be useful for the prediction of its outcome (endoscopic evaluation). However, a reliable marker for molecular evaluation is not obtained so far. On the other hand, long-term control of L-MALT with H. pylori eradication therapy is uncertain and there still remains a subset of patients with no evidence of H. pylori or who fail H. pylori eradication therapy. Therefore, the optimal non antibiotic therapy for these patients has been studied. According to the recent report, radiation therapy appears to be well tolerated and effective for patients with gastric L-MALT.

Combined Modality Therapy↗
PubMed2001

[Helicobacter pylori & gastric disease].

Since the discovery of Helicobacter pylori(H. pylori), causal linkage between H. pylori infection and some of gastric disease has been generally accepted from the results of many studies. Indeed the usefulness of H. pylori eradication therapy for acute gastritis, peptic ulcer, gastric polyp and MALT lymphoma etc. has been reported. In the low grade MALT lymphoma, the regression rate by this therapy is about 70%. On the other hand, we should pay the caution to several adverse effects, such as drug resistance and GERD, of H. pylori eradication therapy. However, based on the several results of comparative studies between antibiotic therapy and the other one, the antibiotic therapy for peptic ulcer is only covered by national health insurance at present. The reversibility of gastric precancerous conditions such as mucosal atrophy, intestinal metaplasia and dysplasia by antibiotic therapy has been studied, but its significance is not clear yet. In animal experiment, H. pylori infection induced gastric adenocarcinoma in Mongolian Gerbils. However, this phenomenon is limited to this kind of animal only. To proof the causal link between H. pylori infection and genesis of gastric cancer in human being, clinical intervention trials are ongoing in the world. If these trials can clarify it, the H. pylori eradication therapy will be established as preventive measure for gastric carcinogenesis.

Animals↗
PubMed2000

Early carcinoma of the gastric cardia in Japan: is it different from that in the West?

BACKGROUND: The incidence of adenocarcinoma of the gastric cardia has increased recently in the West. However, in Japan, most patients with gastric carcinoma have disease that is situated in the body and the distal stomach. The objectives of this study were to compare the clinicopathologic findings of patients with early gastric carcinoma (EGC) arising at the cardia and those with carcinoma in more distal parts of the stomach, then comparing the findings with those from patients with carcinoma of the gastric cardia in the West. METHODS: Three thousand one hundred forty-four patients with EGC who underwent surgical resection between 1962 and 1997 at the National Cancer Center Hospital in Tokyo were studied. Seventy patients with EGC at the cardia were compared with those who had lesions in the middle and lower parts of the stomach. The body mass index (BMI), smoking, and drinking were evaluated using all patients with cardia EGC and 344 patients in a matched cohort in the latter group. RESULTS: Seventy patients had an EGC located just at the cardia, whereas 2796 patients had lesions in the lower two-thirds of the stomach. The former lesions were different from those in the distal two-thirds of the stomach: More often, they were of an elevated type (34% vs. 14%, respectively, they were histologically well differentiated in 89% (vs. 59%), and there were more submucosal tumors (53% vs. 41%). The BMI, smoking, and drinking in the two groups were not different. The incidence of Barrett esophagus and gastroesophageal reflux disease (GERD) in patients with EGC were 2. 9% (2 of 70 patients) and 5.7% (4 of 70 patients), respectively. CONCLUSIONS: There were many significant differences in clinicopathologic characteristics between patients with carcinoma of the cardia and patients with carcinoma of the distal stomach in Japan. The incidence of early cardia carcinoma was very low in Japan, and obesity, smoking, drinking, Barrett esophagus, or GERD were not related to its occurrence, in contrast to reports in the West.

Adenocarcinoma↗
PubMed2000

A hydrogen peroxide-forming NADH oxidase that functions as an alkyl hydroperoxide reductase in Amphibacillus xylanus.

The Amphibacillus xylanus NADH oxidase, which catalyzes the reduction of oxygen to hydrogen peroxide with beta-NADH, can also reduce hydrogen peroxide to water in the presence of free flavin adenine dinucleotide (FAD) or the small disulfide-containing Salmonella enterica AhpC protein. The enzyme has two disulfide bonds, Cys128-Cys131 and Cys337-Cys340, which can act as redox centers in addition to the enzyme-bound FAD (K. Ohnishi, Y. Niimura, M. Hidaka, H. Masaki, H. Suzuki, T. Uozumi, and T. Nishino, J. Biol. Chem. 270:5812-5817, 1995). The NADH-FAD reductase activity was directly dependent on the FAD concentration, with a second-order rate constant of approximately 2.0 x 10(6) M(-1) s(-1). Rapid-reaction studies showed that the reduction of free flavin occurred through enzyme-bound FAD, which was reduced by NADH. The peroxidase activity of NADH oxidase in the presence of FAD resulted from reduction of peroxide by free FADH(2) reduced via enzyme-bound FAD. This peroxidase activity was markedly decreased in the presence of oxygen, since the free FADH(2) is easily oxidized by oxygen, indicating that this enzyme system is unlikely to be functional in aerobic growing cells. The A. xylanus ahpC gene was cloned and overexpressed in Escherichia coli. When the NADH oxidase was coupled with A. xylanus AhpC, the peroxidase activity was not inhibited by oxygen. The V(max) values for hydrogen peroxide and cumene hydroperoxide reduction were both approximately 150 s(-1). The K(m) values for hydrogen peroxide and cumene hydroperoxide were too low to allow accurate determination of their values. Both AhpC and NADH oxidase were induced under aerobic conditions, a clear indication that these proteins are involved in the removal of peroxides under aerobic growing conditions.

Amino Acid Sequence↗
PubMed1999

Factors associated with increased extravascular lung water in cardiac tamponade and myocardial ischemia.

OBJECTIVE: To evaluate and compare the factors associated with pulmonary edema in cardiac tamponade and myocardial ischemia. DESIGN: Prospective, controlled laboratory study. SETTING: Animal research laboratory of a university hospital. SUBJECTS: Fourteen anesthetized dogs. INTERVENTION: Extravascular lung water (EVLW) was measured with thermal indocyanine green dye double-indicator dilution method and hemodynamic indices were determined by the pulmonary artery flotation catheter. Seven dogs were used in the tamponade model, and seven other dogs were used in the myocardial ischemia model. Furthermore, ten dogs were dedicated to measure plasma colloid osmotic pressure (COP) and blood gas analysis during cardiac tamponade and myocardial ischemia. MEASUREMENTS AND MAIN RESULTS: Mean right atrial pressure (MRAP) (7-->10 mm Hg), pulmonary capillary wedge pressure (PCWP) (10-->13 mm Hg), and EVLW (5.4-->10.1 mL/kg) increased during tamponade, but all of these indices returned to the control level after release of tamponade (MRAP, 7 mm Hg; mean PCWP, 11 mm Hg; mean EVLW, 5.2 mL/kg). Myocardial ischemia caused increases in PCWP (10-->14 mm Hg) and EVLW (5.6-->9.6 mL/kg). Although PCWP returned to the control level, EVLW remained elevated (9.2 mL/kg) after reperfusion. EVLW had good correlations with MRAP (r2 = .64, p < .05) and PCWP (r2 = .62, p < .05) during cardiac tamponade. Despite a fair correlation between EVLW and PCWP during ischemia (r2 = .73, p < .05), EVLW was not related to PCWP after reperfusion. COP decreased during myocardial ischemia and at the reperfusion period, but there was no significant change in COP in the cardiac tamponade model. CONCLUSIONS: In contrast to a close relation between hydrostatic pressure and EVLW in cardiac tamponade, hydrostatic pressure was not a determinant of pulmonary edema during the reperfusion period after myocardial ischemia.

Animals↗
PubMed1999

Morphologic correlation between atherosclerotic lesions of the carotid and coronary arteries in patients with angina pectoris.

The morphology of atherosclerosis between the carotid and coronary artery systems was studied in 63 patients with ischemic heart disease to determine if there was a correlation with coronary heart disease. The sclerotic lesions of the carotid and coronary artery systems were imaged with ultrasonography and coronary arteriography, respectively, and divided into 4 types. Hemodynamic variables, serum lipid levels, and serum uric acid concentration were not different among the groups, but the serum C-reactive protein (CRP) concentration in patients without significant atheroma in the carotid artery system was lower than the mean concentration of the other 3 groups with carotid atheroma. The morphological stability of carotid arterial plaques correlated well to coronary artery stenosis. Morphologically unstable plaques of the carotid artery predicted unstable forms of coronary obstruction with a sensitivity of 68%, specificity of 85%, predictive power of 72% and a likelihood ratio of 4.5. These results suggest that ultrasonic examination of the carotid artery is useful for predicting the presence or absence of unstable lesions in coronary arteries.

Aged↗
PubMed1999

Endoscopic and histological reversibility of gastric adenoma after eradication of Helicobacter pylori.

Although epidemiological studies strongly suggest an association between Helicobacter pylori infection and gastric carcinogenesis via a multistage process, a causal link between them has not been demonstrated. We evaluated the endoscopic and histological changes of gastric adenoma, which is considered a premalignant condition, after eradication of H. pylori. Thirty-five H. pylori-infected patients with gastric adenoma were treated with triple therapy (lansoprazole 30mg/day, clarithromycin 400mg/day, and amoxicillin 1500 mg/day) for 1 week. Of these 35 patients, 30 (86%) exhibited no H. pylori by culture or histology after the therapy. Of the 30 gastric adenomas, 7 decreased in size endoscopically; three gastric adenomas especially showed apparent remission, although histological cure in these three patients was not apparent. Our results suggest that removal of H. pylori infection may only mask a gastric adenoma endoscopically owing to the change around the gastric mucosa.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Assessment of "microvascular no-reflow phenomenon" using technetium-99m macroaggregated albumin scintigraphy in patients with acute myocardial infarction.

OBJECTIVES: The aim of this study was the scintigraphic evaluation of clinical no-reflow phenomenon. BACKGROUND: In patients with acute myocardial infarction, the relationship of the severity of reduction of microvascular reflow to the ischemia time or to the secondary extension of myocardial necrosis is poorly understood, and we accordingly conducted a scintigraphic evaluation of clinical no-reflow phenomenon. METHODS: The group studied consisted of 25 consecutive patients with their first acute myocardial infarction. After recanalization, each patient received intracoronary injections of technetium-99m macroaggregated albumin (MAA). RESULTS: Eight patients (32%) had absent tracer uptake (scintigraphic no-reflow phenomenon). Fourteen patients showed absent or moderately reduced MAA uptake (group 1) and 11 showed slightly reduced or normal uptake (group 2). The time to recanalization was significantly longer in group 1 than in group 2 (290.4+/-130.6 min vs. 1773+/-93.5 min; p=0.0238). In chronic phase, the thallium-201 (TI-201) defect score index was significantly larger (p < 0.01) and regional ejection fraction was significantly lower (p < 0.01) in group 1 compared with corresponding values in group 2. No significant deterioration from acute phase to chronic phase in either TI-201 defect score index or regional ejection fraction was found in either group (two-way repeated measures analysis of variance). CONCLUSIONS: These findings suggest that scintigraphic noreflow phenomenon occurs in a subgroup of patients without angiographic no-reflow phenomenon, that the myocardial damage depends on the severity of microvascular damage and that prolonged ischemia time may increase the likelihood of "microvascular no-reflow phenomenon."

Aged↗