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T Tabata

Publications and source records attributed to T Tabata.

At least 109 records · Page 6Linked to original sources
PubMed1997

Transesophageal pulsed Doppler echocardiographic evaluation of left atrial systolic performance in hypertrophic cardiomyopathy: combined analysis of transmitral and pulmonary venous flow velocities.

BACKGROUND: Hypertrophic cardiomyopathy (HC) is characterized by impaired left ventricular (LV) diastolic function due to an increase in LV wall thickness. The severity of this disease varies depending on the localization and extent of the hypertrophied myocardium and the presence and extent of myocardial disarray or fibrosis. HYPOTHESIS: The purpose of this study was to examine the background of hemodynamic abnormalities between the left atrium and the left ventricle during atrial systole in patients with HC using pulsed Doppler echocardiography. METHODS: Hemodynamic abnormalities between the left atrium and left ventricle during atrial systole were evaluated in patients with HC using transmitral flow (TMF) and pulmonary venous flow (PVF) velocities obtained by transesophageal pulsed Doppler echocardiography. The study population included 50 patients with HC, including 39 with asymmetric septal hypertrophy and 11 with apical hypertrophy, and showing fractional shortening of the left ventricle > or = 30%. They were classified into three groups: (1) Group A (n = 11): the ratio of the late to early TMF velocity < 1, and peak atrial systolic PVF velocity (PVA) < 25 mm/s; (2) Group B (n = 13): their ratio < 1, and PVA > or = 25 mm/s; and (3) Group C (n = 26): their ratio > or = 1. The mean age of patients in Group A was lower than that in Groups B and C. RESULTS: Left atrial dimension in Group B was significantly greater than that in the other HC groups and the control group. Furthermore, left atrial volume changes during atrial systole in Group B were significantly smaller than those in the other HC groups and the control group. Peak atrial systolic PVF velocity in Group B was significantly higher than that in the control group and in Group C. The duration of the atrial systolic waves of the TMF and PVF in Group B was significantly shorter and longer, respectively, than that in Group A. Left ventricular end-diastolic pressure (LVEDP) decreased in descending order with Group B > Group C > Group A. In all patients there was a significant positive correlation between the LVEDP and peak atrial systolic PVF velocity or the difference in duration between the atrial systolic waves of PVF and TMF. Plots of these values shifted toward the left and inferiorly in Group A, and toward the right and superiorly in Group B. CONCLUSION: Peak velocity and duration of TMF and PVF during atrial systole by transesophageal pulsed Doppler echocardiography are useful indices of hemodynamic abnormalities between the left atrium and the left ventricle during atrial systole, particularly a forceful atrial contraction mismatched to the left atrial afterload and severity of LV diastolic dysfunction, in HC.

Adult↗
PubMed1997

Echocardiographic characteristics and causal mechanism of physiologic mitral regurgitation in young normal subjects.

BACKGROUND: It has become evident that mitral regurgitation (MR) is not uncommon in healthy subjects, and Doppler color flow mapping is a technique that imparts important information relevant to its detection. HYPOTHESIS: Using transthoracic echocardiography, this study evaluated the mechanism of physiologic MR in young normal subjects using transthoracic echocardiography. METHODS: The study population consisted of 48 young normal subjects (mean 21 +/- 5 years) with MR (physiologic MR group), 40 age-matched young normal subjects (mean 20 +/- 5 years) without MR (control group), 45 patients (mean 41 +/- 15 years) with mitral valve prolapse with MR (MVP group), and 27 patients (mean 59 +/- 13 years) with ruptured chordae tendineae (rupture group). RESULTS: Men were predominant in the rupture group, whereas there were no significant gender differences in the other three groups. Left ventricular end-diastolic dimension and left atrial systolic dimension were slightly smaller in the physiologic MR group than in the control group, but were significantly smaller than those in the MVP and rupture groups. The ratio of the maximum anteroposterior diameter to the maximum transverse diameter on chest radiography and the ratio of the short- to long-axis diameter of the left ventricular cavity at end diastole, determined from two-dimensional short-axis echocardiogram, were significantly lower in the physiologic MR group than in the other three groups. Mitral regurgitation occurred more frequently at the posteromedial commissural site in the physiologic MR and MVP groups, whereas there was no preference for location in the rupture group. Early systolic MR was often observed in the physiologic MR group, whereas pansystolic MR was common in the MVP and rupture groups. CONCLUSION: As a causal mechanism for physiologic MR detected in young normal subjects, "flattening" of the thorax during growth may cause morphologic abnormalities of the left atrial and ventricular cavities, resulting in spatial imbalance of the mitral complex and resulting in malcoaptation of the valve.

Adult↗
PubMed1997

Atherogenic lipoprotein changes in the absence of hyperlipidemia in patients with chronic renal failure treated by hemodialysis.

We compared plasma lipid and lipoprotein parameters between 210 chronic renal failure patients treated by hemodialysis and 223 age- and sex-matched healthy control subjects to examine whether atherogenic lipoprotein changes were present in hemodialysis patients in the absence of hyperlipidemia. The hemodialysis group showed higher levels of plasma triglycerides, very low density lipoprotein (VLDL) cholesterol, and intermediate density lipoprotein (IDL) cholesterol and a lower level of high density lipoprotein (HDL) cholesterol. Low density lipoprotein (LDL) cholesterol of the hemodialysis group was not elevated but their LDL was significantly more triglyceride-enriched than that of controls. Subjects were then divided into five categories according to their plasma triglyceride levels at an interval of 50 mg/dl, and comparison was made between the two groups in the same range of plasma triglycerides. Hemodialysis patients again showed higher levels of VLDL- and IDL-cholesterol, and lower levels of HDL-cholesterol than the control group even in the plasma triglycerides-matched comparisons. Similarly, higher VLDL- and IDL-cholesterol levels in hemodialysis patients were significant in plasma total cholesterol-matched subgroup comparisons. Multiple regression analysis indicated that the relationship between plasma lipid concentrations and individual lipoprotein levels were substantially altered in uremic state. The 95th percentile level of IDL-cholesterol in the nonuremic controls was 15 mg/dl, and 45% of hemodialysis patients exceeded this level. Decreased HDL-cholesterol levels < or = 35 mg/dl were seen in 6% of the control and 38% of the hemodialysis group. Elevated IDL-cholesterol and decreased HDL-cholesterol were persistently found in hemodialysis patients with normal lipid levels. It is concluded that hemodialysis patients exhibited more atherogenic lipoprotein profile than nonuremic subjects with comparable levels of plasma triglycerides and total cholesterol. Especially, increased IDL- and decreased HDL-cholesterol levels in hemodialysis patients persisted even at very low levels of plasma lipids. Since elevated IDL and decreased HDL-cholesterol are implicated in the progression of atherosclerosis, these findings are of clinical importance in the diagnosis of lipoprotein disorder in chronic renal failure.

Arteriosclerosis↗
PubMed1997

Inhibition of lymph node metastasis by an anti-angiogenic agent, TNP-470.

We assessed the inhibitory action of TNP-470 on lymph node metastasis in a metastatic model system using athymic nude mice. Mice were injected subcutaneously with 5 x 10(6) HT-1080 cells in the right groin. TNP-470 (10, 30 and 100 mg kg-1) was injected subcutaneously nine times in total every other day from the 7th day after tumour inoculation. Axillar and inguinal lymph nodes were dissected, and DNA was extracted 5 weeks after tumour inoculation. Specific detection of a human beta-globin-related sequence in metastasized human tumour cells in nude mice was done by the polymerase chain reaction (PCR) technique and analysed by Southern blotting. Anti-tumour effects on primary sites were seen only in the 100 mg kg-1 treatment group. Lymph node metastasis of transplanted HT-1080 cells was seen in all mice of the no treatment group (5/5). On the other hand, incidences of lymph node metastasis in treated mice were 2/4 mice (100 mg kg-1, 2/5 mice (30 mg kg-1) and 4/5 mice (10 mg kg-1). The inhibition ratios of lymph node metastasis were 82.3% at 10 mg kg-1, 97.2% at 30 mg kg-1 and 97.5% at 100 mg kg-1 respectively. This agent may be useful to inhibit lymph node metastasis.

Animals↗
PubMed1997

Relation of disease activity during chronic hepatitis C infection to complexity of hypervariable region 1 quasispecies.

We studied the heterogeneity in the E2/NS1 hypervariable region 1 of the hepatitis C virus (HCV) genome in relation to the natural course after infection. The subjects were composed of 38 chronic hepatitis C carriers who had been followed for 9 to 218 months after the onset of non-A, non-B (type C) hepatitis, being tested monthly for serum alanine aminotransferase levels. The complexity of the sequence heterogeneity was assessed by single-strand conformation polymorphism analysis. The quasispecies complexity had no relation to the route of infection, the time from infection and the duration of aminotransferase elevation after the onset. However, it had a significant relationship with the degree of aminotransferase elevation in the course of the disease. The quasispecies complexity was directly correlated with the first peak of serum aminotransferase at the onset (r = .48, P < .01) and the mean aminotransferase levels during the period of persistent aminotransferase elevation (r = .58, P < .01). Twenty-three of the 38 patients were further followed for 24 months with biweekly alanine transaminase (ALT) tests. Their aminotransferase levels remained within the normal range during follow-up, and no significant change was seen in the quasispecies complexity after this asymptomatic period. However among the 23 patients, the quasispecies complexity increased in six cases (26%) and decreased in five (22%). A significant direct relation was seen between changes in the quasispecies complexity and the mean aminotransferase levels during the asymptomatic period (r = .55, P = .01). These findings suggest that the development of the HCV quasispecies nature may be related to the severity of the hepatitis in the course of infection.

Adult↗
PubMed1997

[Development of an experimental rat model of intraabdominal abscess by Escherichia coli alone. I. Materials for abscess formation].

To develop a new animal model of intraabdominal abscess by Escherichia coli alone, we reevaluated anaerobes and other additions which had been believed necessary to produce an intraabdominal abscess. We took the method of bacterial implantation by insertion of a double gelatin capsules containing microbes and the additions into the peritoneal cavity of male Wister rats. We examined the requirement of causative bacteria for an abscess including both aerobes and anaerobes, sterilized feces, and barium sulfate. It has been proven that a simple and well reproducible intraabdominal abscess can be developed without fail at the seventh day after inoculation although anaerobic bacteria, sterilized feces, and barium sulfate are not used. However, we have failed to produce an abscess without sterilized gauze fiber which should be a core of an abscess and is used instead of sterilized feces. This animal model will contribute to a major simplification of the original one heretofore in use, and is expected to serve as an aid to elucidate the mechanisms of abscess formation.

Abdominal Abscess↗
PubMed1997

[Development of an experimental rat model of intraabdominal abscess by Escherichia coli alone. II. Interactions between an intraabdominal abscess and a host].

It has been demonstrated that an intraabdominal abscess by Escherichia coli alone can be developed without fail although anaerobes or barium sulfate are not used. We investigated the properties and the influence of this abscess on the host. We took the method of bacterial implantation by insertion of a double gelatin capsules containing Escherichia coli suspension of which concentration was adjusted to five grades into the peritoneal cavity of Wister rats. Abscesses were developed in the survived rats on which live bacteria had been inoculated. Only Escherichia coli were found in these abscesses by culture whereas no death was occurred and no abscess was developed in the rats on which no bacterium or heat-killed ones had been inoculated. As for non-survivors at the 7th postoperative day, all of them died of panperitonitis and no abscess was developed. An abscess was developed without fail when live bacteria of which number within the order of 10(7) colony forming units were inoculated. Blood endotoxin concentration 24 hours after inoculation increased exponentially according to the inoculum size. However, that at the 7th postoperative day returned to the levels at zero time. Microscopic examination revealed a thick abscess wall, poor infiltration of inflammatory cells, and poor neovascularsis into the wall. These findings suggest that endotoxin is prevented from release into the blood stream since abscess contents are isolated by thick wall.

Abdominal Abscess↗
PubMed1997

Cross sectional echocardiographic demonstration of the mechanisms of abnormal interventricular septal motion in congenital total absence of the left pericardium.

OBJECTIVE: To investigate the influence of the absence of the pericardium on the left ventricular wall, particularly on interventricular septal motion, using M mode and cross sectional short axis echocardiography in patients with congenital total absence of the left pericardium. METHODS: 21 patients with, congenital total absence of the left pericardium were divided into three groups according to the interventricular septal motion; systolic type (n = 6) with paradoxical motion during systole, diastolic type (n = 11) with abnormal posterior motion during mid to late diastole, and mixed type (n = 4) with paradoxical motion during systole and abnormal posterior motion during diastole. RESULTS: On cross sectional short axis echocardiograms of the left ventricle, in the diastolic type the degree of angular displacement of the papillary muscles during end diastole to end systole showed excessive anticlockwise rotation about the long axis of the left ventricle without marked anteroposterior displacement. In the systolic type, there was shift of the left ventricle towards the anteromedial portion in systole and towards the posterolateral portion in diastole without significant rotation. There was a significantly positive correlation between the degree of angular displacement and the amplitude of diastolic interventricular septal motion during mid to late diastole in all patients. CONCLUSIONS: There was abnormal interventricular septal motion during systole and diastole in patients with total absence of the left pericardium. Abnormal systolic motion was induced by anteroposterior displacement of the left ventricle, and abnormal diastolic motion by left ventricular rotation about the long axis of the heart during the cardiac cycle. Analysis using cross sectional echocardiography was useful for elucidating the mechanisms of abnormal interventricular septal motion.

Adult↗
PubMed1997

History of vitamin D treatment of renal osteodystrophy.

Vitamin D treatment was tried when renal osteodystrophy was first recognized in the early 20th century, using vitamin D2, D3, or dihydrotachysterol. Large doses of vitamin D2 or D3 (150,000-500,000 IU) were prescribed by monitoring serum calcium, phosphate, and alkaline phosphatase. After the discovery of 1,25-dihydroxycholecalciferol, this compound or 1 alpha-hydroxycholecalciferol was applied to the treatment of renal osteodystrophy. In a preclinical study, especially of 1 alpha-hydroxycholecalciferol, nephritogenoside nephritis was the most responsive condition. These active vitamin D preparations are now widely used in patients with chronic renal failure under hemodialysis. Other active vitamin D compounds, such as hexafluoro-1,25-dihydroxycholecalciferol and 22-oxacalcitriol, are also under investigation.

Animals↗
PubMed1997

Concealed left ventricular hypertrophy and diastolic dysfunction in hypertrophic cardiomyopathy in the presence of acute left ventricular volume overload. A case report.

We report a patient in whom hypertrophic cardiomyopathy, with both left ventricular hypertrophy and diastolic dysfunction, was masked by acute severe aortic regurgitation and marked left ventricular dilation. Upon admission, 1) two-dimensional echocardiogram of the left ventricle revealed a dynamic and flail vegetation on the aortic right coronary cusp and marked left ventricular dilation, 2) a massive aortic regurgitant signal was recorded by color Doppler flow imaging, and 3) transmitral flow velocity by pulsed Doppler echocardiogram revealed a pseudonormalization. However, symmetric hypertrophy of the left ventricular wall, a decrease in early diastolic wave and a compensatory increase in atrial systolic wave of the transmitral flow velocity appeared after successful aortic valve replacement.

Aortic Valve↗
PubMed1997

Transesophageal echocardiographic prediction of initially successful electrical cardioversion of isolated atrial fibrillation. Effects of left atrial appendage function.

Left atrial appendage (LAA) flow velocities prior to electrical cardioversion were recorded using transesophageal pulsed Doppler echocardiography to predict initially successful cardioversion of isolated atrial fibrillation (AF). Patients with AF were placed into either a success group (19 patients) in which sinus rhythm was maintained for at least 2 days or a failure group (12 patients). The duration of AF was shorter in the success group. The maximum left atrial diameter was the same for the two groups. The maximum LAA area was smaller in the success group. The maximum forward and backward LAA velocities were greater in the success group, as were the mean forward and backward LAA velocities. In the patients with mean LAA flow velocities greater than 19 cm/sec, the success of cardioversion could be predicted with high sensitivity (80%) and specificity (88%). We conclude that the duration of AF, the maximum LAA area, and LAA flow velocities prior to cardioversion predict the initial recovery of sinus rhythm for isolated AF.

Adult↗
PubMed1997

[Clinical study of gasless laparoscopic adrenalectomy in 17 cases--comparison between laparoscopic adrenalectomy with and without pneumoperitoneum].

PURPOSE: To determine the efficiency of gasless laparoscopic adrenalectomy, this procedure was compared to that with pneumoperitoneum. PATIENTS AND METHODS: Between February 1994 and December 1996, 17 gasless laparoscopic adrenalectomy were performed in 5 men and 12 women, 36 to 79 years old. Clinical diagnosis was primary aldosteronism in 8, pheocromocytoma in 2, incidentaloma in 4 and adrenal cyst in 3. When gasless laparoscopic adrenalectomy was performed, the laparoscope was inserted through the upper margin of the umbilicus by open laparotomy. To create a workable space, a 1.2 mm Kirschner wire was advanced subcutaneously below the costal arch and attached to a retractor. Operating time, estimated blood loss, changes of the end tidal CO2 concentration during operation, operative complications and postoperative course were compared to those with pneumoperitoneum in 12 cases. RESULTS: In both procedures, satisfying workable spaces were created in all cases. The mean operating time and estimated blood loss were 245 min and 201 ml without pneumoperitoneum, 317 min and 274 ml with pneumoperitoneum, respectively. The mean changes of end tidal CO2 concentration during operation were 3.2 mmHg without pneumoperitoneum and 5.1 mmHg with pneumoperitoneum. As operative complications, open operations were required in 2 cases (1 without pneumoperitoneum and another with pneumoperitoneum) to control intraoperative bleeding. They had the histories of transabdominal operations. Postoperative bleeding was observed in 2 cases (1 without pneumoperitoneum and another with pneumoperitoneum). One of them (with pneumoperitoneum) needed surgical management for hemostasis. Fever over 38 degrees C that occurred in 1 case with pneumoperitoneum appeared to be absorption fever. No differences were observed in the number of the days to the start of oral intake and for postoperative hospitalization between the two groups. CONCLUSIONS: Gasless laparoscopic adrenalectomy is available for most adrenal tumors. Suction could be used unrestrictedly and there were no hemodynamic or ventilatory effects due to pneumoperitoneum. This procedure appears to be safe and advantageous for the treatment of most adrenal tumors.

Adrenal Gland Diseases↗
PubMed1997

[A case of systemic origin of an aberrant artery to the basal segment of the lung].

We report on a rare case of systemic origin of an aberrant artery to the basal segment of the lung (Pryce I type intralobar pulmonary sequestration) that caused occasional bloody sputum. The patient was admitted to our hospital after an abnormal image was discovered in Chest X-ray film. The chest MRI showed an abnormal vessel originating from the descending aorta. The aortagram showed an abnormal artery originating from the descending aorta and entering the left lower lobe, and the left pulmonary angiogram revealed a poorly blood supply to the left basal segments. The preoperative diagnosis of systemic origin of an aberrant artery to the basal segment of the lung was given. The patient was subjected to surgical treatment. During surgery, it was found that the abnormal artery, 12 mm in diameter, which was connected from the descending aorta to the left basal segments. The abnormal artery was dissected, and the left basal segments was removed. The postoperative course was uneventful.

Aorta, Thoracic↗
PubMed1997

[Role of leukotriene B4 in monocrotaline-induced pulmonary hypertension].

Monocrotaline (MCT) causes lung inflammation and chronic pulmonary hypertension associated with lung vascular thickening in rats. We hypothesized that leukotriene B4 (LTB4) and LTB4-induced accumulation of leukocytes in the lung play a role in MCT-induced lung disease, and therefore measured LTB4 and myeloperoxidase (MPO) levels in lung tissue of MCT-treated rats. Next, we examined the effect of an orally active LTB4 receptor antagonist (ONO4057) on MPO levels in lung tissue, on pulmonary hypertension, and on pulmonary vascular remodeling induced by MCT. Lung LTB4 and MPO levels had increased by 3 days after MCT injection. In the ONO4057-treated MCT rats, lung MPO levels were significantly lower than in the rats given MCT but not ONO4057. By the third week after injection. MCT had caused increases in mean pulmonary arterial pressure, in the ratio of right ventricular weight to left ventricle+septum weight (RV/[VS + S]), and in media wall thickness of the muscular arteries of the lung. Treatment with ONO4057, either for 3 weeks or during the first week after MCT injection, significantly reduced pulmonary hypertension, right ventricular hypertrophy, and lung vascular thickening induced by MCT. These results indicate that ONO4057 reduces both the accumulation of leukocytes in lung tissue and the chronic pulmonary hypertension induced by MCT, and they suggest a role for LTB4 in the inflammatory process that contributes to pulmonary hypertension and lung vascular remodeling induced by MCT in rats.

Animals↗
PubMed1997

Tricuspid inflow and regurgitant flow dynamics after mitral valve replacement: differences relating to surgical repair of the tricuspid valve.

BACKGROUND AND AIMS OF THE STUDY: Changes in tricuspid inflow and regurgitant flow dynamics were evaluated in patients with functional tricuspid regurgitation (TR) who underwent mitral valve replacement (MVR) with and without tricuspid annuloplasty (TAP). METHODS: In a group of 30 patients, all with atrial fibrillation, 15 underwent TAP performed according to the modified De Vega technique; the remaining 15 did not undergo TAP. Patients were studied before and serially after surgery, using pulsed and color Doppler echocardiography. The mean follow up was 4.7 years in the TAP group and 5.1 years in the non-TAP group. RESULTS: In the TAP group, immediately after surgery, the area of the TR jet decreased markedly, and the deceleration time of the tricuspid inflow velocity wave was significantly prolonged compared with that before surgery. By contrast, in the non-TAP group, both the area of the TR jet and deceleration time of tricuspid inflow velocity were virtually unchanged. The area of the TR jet remained small for a long period in the TAP group, but in non-TAP patients was increased in four cases over seven years, with two patients developing right-sided heart failure. Recent data showed the area of the TR jet to be significantly smaller, with maximum tricuspid inflow velocity significantly increased, and deceleration time of the tricuspid inflow velocity wave significantly prolonged in the TAP group compared with the non-TAP group. CONCLUSIONS: In patients with functional tricuspid regurgitation undergoing MVR, concomitant TAP may cause mild tricuspid stenosis, but produces sustained preventive effects against TR. Careful follow up is needed in patients who have not undergone TAP, as TR is not markedly decreased and may even be exacerbated. Aggressive TAP is recommended in patients showing dilatation of the tricuspid annulus, even if TR is mild.

Adult↗
PubMed1997

The 'sail sound' and tricuspid regurgitation in Ebstein's anomaly: the value of echocardiography in evaluating their mechanisms.

We describe a patient with Ebstein's anomaly in whom Doppler echocardiography was used to clarify the mechanism responsible for 'sail sound' and tricuspid regurgitation associated with this condition. Phonocardiography revealed an additional early systolic heart sound, consisting of a first low-amplitude component (T1) and a second high-amplitude component (T2, 'sail sound'). In simultaneous recordings of the tricuspid valve motion using M mode echocardiography and phonocardiography, the closing of the tricuspid valve occurred with T1 which originated at the tip of the tricuspid leaflets, while T2 originated from the body of the tricuspid leaflets. Using color Doppler imaging, the tricuspid regurgitant signal was detected during pansystole, indicating a blue signal during the phase corresponding to T1 and a mosaic signal during the phase corresponding to T2 at end-systole. Thus, 'sail sound' in patients with Ebstein's anomaly is not simply a closing sound of the tricuspid valve, but a complex closing sound which includes a sudden stopping sound after the anterior and/or other tricuspid leaflets balloon out at systole.

Diagnosis, Differential↗