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Biomedical subjects

Y Otake

Publications and source records attributed to Y Otake.

At least 37 records · Page 2Linked to original sources

Expression of thymidylate synthase in human non-small cell lung cancer.

5-Fluorouracil (5-FU) has been used worldwide, and the correlation between its effects and thymidylate synthase (TS) expression has been reported in gastrointestinal malignancy. But the significance of TS expression for 5-FU-based chemotherapy has rarely been reported in non-small cell lung cancer (NSCLC). We investigated surgically resected specimens of 23 consecutive patients with previously untreated NSCLC. We used immunohistochemistry and western blot analysis with anti-TS polyclonal antibody to evaluate the existence of TS, and fluorodeoxyuridine-5'-monophosphate (FdUMP) binding assay to evaluate the enzymic activity of TS. We found that 14 samples (60.9%) were positive immunohistochemically, and that the results of immunohistochemistry closely reflected the enzymic activity measured by FdUMP binding assay (ranging from 1.8 to 56.9 pmol/g protein). These results seem to support our experience that 5-FU and its derivatives are clinically significantly effective as a postoperative adjuvant chemotherapy against NSCLC.

Adult↗

Assessment of left atrial appendage function after cardioversion of atrial fibrillation: relation to left atrial mechanical function.

Although several flow patterns in the left atrial appendage have been described, mechanical determinants of its function have not been elucidated in human beings. We attempted to investigate changes in left atrial appendage function after cardioversion of atrial fibrillation and examine the potential relation between appendage function and left atrial mechanical function. Twenty patients without mitral valvular disease underwent transesophageal and transthoracic echocardiography at 24 hours and 1 week after cardioversion of atrial fibrillation. Left atrial appendage function was assessed by the pulsed Doppler measurements of left atrial appendage emptying and filling velocities corresponding to early and late ventricular diastole, respectively. Left atrial mechanical function was evaluated by the transmitral A-wave velocity, percent atrial contribution of the total left ventricular filling (percent atrial filling), and the pulmonary venous A-wave velocity. Left ventricular function was also estimated with conventional M-mode echocardiography. The late appendage emptying and filling velocities markedly increased during 1 week after cardioversion (p < 0.0001, respectively). This finding was associated with an increase in left atrial mechanical function. Changes in the late emptying and filling velocities significantly correlated with changes in the transmitral A-wave velocity (r = 0.59, p < 0.01), percent atrial filling (r = 0.61, p < 0.005), and the pulmonary venous A-wave velocity (r = 0.56, p < 0.05). In contrast, little change was observed in the early emptying and filling velocities. There was no relation between the indexes of left ventricular function and those of appendage function. In conclusion, unless there was an alteration of the loading conditions, left atrial appendage function improved over several days after cardioversion, and its function was related to left atrial mechanical function.

Adult↗

Improvement of lichen nitidus after topical dinitrochlorobenzene application.

Recently, a relationship between immunologic alterations and the development of lichen nitidus (LN) lesions has been described. We treated LN lesions with topical dinitrochlorobenzene (DNCB) application in a patient with peripheral CD4+ T lymphocytopenia. After 4 months, the eruption cleared. We investigated histologically and immunohistochemically biopsy specimens obtained before and after treatment. Our result suggests that local alterations of the pattern of cells and cytokines by topical DNCB application could have contributed to the resolution of the LN lesions.

Administration, Topical↗

Cryoglobulinaemia among maintenance haemodialysis patients and its relation to hepatitis C infection.

It has been shown that hepatitis C virus (HCV) infection is closely associated with mixed type cryoglobulinaemia. It is also known that HCV infection is rampant among chronic haemodialysis patients. We studied 531 renal failure patients on maintenance dialysis including 170 with positive HCV antibodies for cryoglobulinaemia, and its incidence was compared with controls which consisted of 242 chronic hepatitis C patients without renal failure and 183 healthy adults. Cryoglobulinaemia was present in 30.6% of dialysis patients with HCV infection, 10.8% of dialysis patients without HCV infection, 29.8% of patients with chronic hepatitis C without renal failure, and 0% of healthy adults. Among the 30 new renal failure patients who were started on dialysis within 6 months, four were positive for HCV antibodies, and one of them had cryoglobulinaemia; of the 26 HCV-negative patients, four (15%) were cryoglobulinaemic. The cryocrit values among dialysis patients were much lower than those of the control cases and other reports on non-dialysis cases. Patients with cryoglobulinaemia were generally younger compared with patients negative for this condition. There was no correlation between cryoglobulinaemia and past blood transfusion, underlying disease or length of dialysis. Cryoglobulinaemic patients seem to develop renal failure at relatively young ages and a considerable proportion of cryoglobulinaemic dialysis patients may have already had cryoglobulinaemia at the time of the start of haemodialysis. There was no indication that the presence of cryoglobulin in serum adversely affects the liver disease nor increases serum virus load in HCV-infected dialysis patients. Thus, it was concluded that although HCV infection has a certain role in the development of cryoglobulinaemia in dialysis patients, they develop cryoglobulinaemia less frequently and produce cryoglobulin to a lesser degree in the presence of HCV infection as compared with non-dialysis patients.

Adult↗

Effect of beta-blocker treatment in dilated cardiomyopathy with bradyarrhythmias.

This study was performed to evaluate whether beta-blocker therapy was effective in patients with nonischemic dilated cardiomyopathy (DCM) and bradyarrhythmias supported by pacemaker implantation. Beta-blocker therapy is useful for some patients with DCM, especially those with rapid heart rate or residual nonfibrotic myocardium in the left ventricle, but no data exist on whether beta-blocker therapy is useful in patients with DCM and bradyarrhythmias. The effectiveness of beta-blocker therapy was prospectively evaluated in patients with DCM and bradyarrhythmias supported by pacemaker implantation and compared with those without these arrhythmias. Beta-blocker therapy was started in 63 patients (45 men, 18 women, aged 11-83 years) with DCM, in whom 7 had bradyarrhythmias and 56 did not. These bradyarrhythmias were atrioventricular block, sick sinus syndrome and atrial fibrillation with slow heart rate. Of the 56 patients without bradyarrhythmias, 42 (75%) (group 1) responded to beta-blocker therapy, but 5 of the 7 with bradyarrhythmias (71%) (group 2) also responded. Left ventricular end-diastolic dimension was reduced (6.5 +/- 0.6 cm to 5.6 +/- 0.5 cm; p < 0.0001 in group 1; 6.6 +/- 0.8 cm to 5.5 +/- 0.2 cm; p < 0.02 in group 2) and left ventricular fractional shortening was improved (13 +/- 4% to 27 +/- 7%; p < 0.0001 in group 1; 12 +/- 4% to 29 +/- 10%; p < 0.05, in group 2) to the same degree in both groups. These results indicate that beta-blocker therapy for DCM is effective not only in patients without bradyarrhythmias but also in those with bradyarrhythmias supported with pacemaker implantation.

Adolescent↗

Solitary papillary muscle hypertrophy as a possible form of hypertrophic cardiomyopathy.

Patients can present with hypertrophied papillary muscles in the left ventricle, even without hypertrophy in other segments, and they have electrocardiographic (ECG) abnormalities suggestive of hypertrophic cardiomyopathy (HCM). This study was performed to evaluate whether the solitary papillary muscle hypertrophy was related to HCM. By analyzing 6731 echocardiographic studies between 1990 and 1994, the incidence of patients with papillary muscle hypertrophy was retrospectively examined, as well as the ECG features and family history related to HCM in these patients. After the normal size of the anterolateral and posteromedial papillary muscles was obtained from echocardiographic studies in 40 healthy subjects (0.7 +/- 0.2 cm for each of the vertical and horizontal axis), papillary muscle hypertrophy was defined as follows: either the vertical or horizontal diameter of at least one of the 2 papillary muscles was more than 1.1 cm (mean+2SD in the normal subjects). Using this definition, 29 patients with papillary muscle hypertrophy were identified, of whom 14 (48%) showed high voltage QRS complexes, 10 (34%) showed T wave inversion, and 6 (21%) showed abnormal Q waves. Ten patients (34%) had a family history of HCM. In 2 patients that were followed for 18 and 11 years, respectively, the voltages of the QRS complexes and inverted T waves progressed with the hypertrophy of the papillary muscle. These findings suggest that solitary papillary muscle hypertrophy is related to HCM and that papillary muscle hypertrophy is a newly identified subtype of or an early form of HCM.

Adolescent↗

Iodine-123 metaiodobenzylguanidine myocardial scintigraphy for prediction of response to beta-blocker therapy in patients with dilated cardiomyopathy.

This study was performed to evaluate whether iodine-123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy could predict the response to beta-blocker therapy in patients with nonischemic dilated cardiomyopathy (DCM). Beta-Blocker therapy is effective in some patients with DCM. MIBG myocardial scintigraphy has also been suggested to be useful in evaluating the severity of myocardial damage in DCM. However, no data exist on whether MIBG imaging can be used to predict which patients with DCM will respond to beta-blocker therapy. We prospectively evaluated whether MIBG myocardial imaging was useful in predicting responses to beta-blocker therapy in patients with DCM. MIBG imaging was performed in 45 patients with DCM (35 men, 10 women, aged 13 to 68 years) before the start of bisoprolol. The heart to mediastinum (H/M) MIBG uptake ratio was evaluated on initial and delayed images, and the percent washout rate of myocardial MIBG was also obtained from these data. Of the 45 patients, 30 (67%) responded to beta-blocker therapy, whereas 2 were resistant and 13 showed progression of heart failure or died of heart failure. By logistic regression analysis, the H/M uptake ratio on delayed images was seen to be a good predictor of the response to beta-blocker therapy with a threshold of 1.7 (sensitivity = 91%, specificity = 92%, accuracy = 91%, positive and negative predictive value = 97% and 80%, respectively). These results indicate that an H/M ratio > 1.7 on the delayed MIBG myocardial scintigraphic images provides a useful indication of whether patients with DCM will respond to beta-blocker therapy.

3-Iodobenzylguanidine↗

Left ventricular Doppler filling pattern in dilated cardiomyopathy: relation to hemodynamics and left atrial function.

This study attempted to examine the relation of left ventricular filling patterns to hemodynamic status and left atrial function in dilated cardiomyopathy. Transesophageal echocardiography and cardiac catheterization were performed in 41 patients with dilated cardiomyopathy (six with an ischemic origin). Transmitral, left atrial appendage, and pulmonary venous flow velocities were recorded with the pulsed Doppler method. Left atrial systolic function was assessed by the peak velocity of the left atrial appendage emptying wave and pulmonary venous flow reversal during atrial systole. Patients were classified into three groups according to their left ventricular filling patterns. Group 1 showed an abnormal relaxation pattern (E wave/A wave ratio <1, n = 17), group 2 had a normal or pseudonormal pattern (1 < or = E/A < 2, n = 11), and group 3 had a restrictive pattern (E/A > or = 2, n = 13). No differences were found among the groups with regard to age, gender, heart rate, and M-mode echocardiographic indices of left ventricular function. Compared with patients in group 1, those in groups 2 and 3 had more symptoms (New York Heart Association functional class III or IV) and had higher left ventricular filling pressures. The sensitivity of an E/A ratio > or = 1 for predicting a pulmonary capillary wedge pressure > or = 15 mm Hg was 75% and the specificity was 94%. Despite a similar increase of filling pressures, group 3 patients had a lower left atrial appendage emptying velocity, pulmonary venous flow reversal velocity, and mitral A velocity than did group 2 patients. The sensitivity and specificity of an E/A ratio > or = 22 for detecting left atrial dysfunction (left atrial appendage emptying velocity < or = 40 cm/sec) was 85% and 86%, respectively. In conclusion, among patients with dilated cardiomyopathy, those who had a restrictive or pseudonormal filling pattern were in a higher functional class and had higher filling pressures. Further studies are needed to determine the therapeutic and prognostic significance of left atrial dysfunction, which was common in patients with a restrictive pattern.

Adult↗

Comparison of immediate and long-term outcome of percutaneous transvenous mitral commissurotomy in patients who have and have not undergone previous surgical commissurotomy.

This study compared the immediate and long-term outcome of percutaneous transvenous mitral commissurotomy (PTMC) in patients who had (restenosis group, n = 9) or had not (de novo group, n = 27) previously undergone surgical mitral commissurotomy. The baseline echocardiographic score, which is an index of deformity of the mitral valve apparatus, was significantly higher in the restenosis group than in the de novo group (11 +/- 3 vs 7 +/- 2, p < 0.01), although age, left atrial diameter, and the prevalence of atrial fibrillation were similar. PTMC was performed by the Inoue technique, and was abandoned in 1 patient from the restenosis group because of failed trans-septal puncture. Including this patient, 3 patients (33%) in the restenosis group had a thickened atrial septum compared with only 1 (4%) in the de novo group. One patient in the de novo group developed cardiac tamponade during this procedure. In both groups, the mitral valve area increased significantly, but the success rate of PTMC was lower in the restenosis group (4/9 patients, 44%) than in the de novo group (22/27 patients, 81%) (p < 0.05). Twenty-six patients who had successful PTMC were followed up over 51 +/- 14 months. After 4 years of follow-up. 3 out of 4 patients (75%) in the restenosis group and 3 out of 22 patients (14%) in the de novo group demonstrated echocardiographic restenosis (p < 0.01). Stepwise multivariate analysis revealed that the echocardiographic score was the only significant predictor of both the immediate and long-term outcome. In conclusion, the immediate and long-term outcome of PTMC were worse in patients who had undergone previous surgical mitral commissurotomy than in those who had not. This was mainly attributable to the difference in the severity of the valvular lesions. In addition, our data suggested that a thickened atrial septum, possibly related to surgery as well as chronic rheumatic disease, may affect the performance of PTMC.

Adult↗

[Adjuvant chemotherapy for non-small cell lung cancer].

Surgery is the first choice for patients in the early stage of non-small cell lung cancer (NSC-LC). But, even for pathologic stage I patients, the post-operative survival remains unsatisfactory; the five-year survival rate is around 70 percent, in spite of potential curative resections. Therefore, post-operative adjuvant chemotherapy is considered to be necessary to improve the survival. Although many prospective randomized studies of post-operative adjuvant chemotherapy have been conducted, the efficacy of post-operative chemotherapy for NSCLC has not been proved (a consensus report of post-operative adjuvant treatment for NSCLC, 3rd IASLC Workshop, Bruges, August 1993). It has been recently reported by the West Japan Study Group for Lung Cancer Surgery (WJSG) that oral administration of UFT (a mixture of tegafur and uracil) as a post-operative adjuvant chemotherapy is effective for patients with complete resected NSCLC (stage I to III) and that UFT administration is tolerable with mild adverse effects in most patients. In order to improve postoperative survival of patients with more advanced stage NSCLC (e.g., bulky N2, III b), we has introduced biochemical modulation therapy using 5-FU, UFT combined with CDDP.

Antineoplastic Combined Chemotherapy Protocols↗

Influence of left atrial function on Doppler transmitral and pulmonary venous flow patterns in dilated and hypertrophic cardiomyopathy: evaluation of left atrial appendage function by transesophageal echocardiography.

Information regarding the relation of left atrial (LA) function to transmitral and pulmonary venous (PV) flow is limited. Using transesophageal echocardiography, we analyzed this relation in 23 patients with dilated cardiomyopathy (DCM) and 25 patients with hypertrophic cardiomyopathy (HCM). Left atrial appendage (LAA) function was assessed as a substitute for overall LA function. Transmitral and PV flow-velocity variables, the LAA emptying flow velocity (LAA-A), and the LAA ejection fraction (LAA-EF) were determined. Each patient group was divided into two subgroups with a normal ( < 15 mm Hg) or elevated ( > or = 15 mm Hg) mean pulmonary wedge pressure (PWP). Transmitral and PV flow patterns as well as LA function were similar in the two subgroups with a normal PWP (11 patients with DCM and 14 patients with HCM). For the subgroups with an elevated PWP, however, the peak velocity ratio of the early filling wave (E) to atrial contraction wave (A) was higher in DCM patients (n = 12) than in HCM patients (n = 11) (2.1 +/- 0.7 vs 1.3 +/- 0.2; p < 0.01). This difference mostly resulted from a lower A velocity in the DCM group than in the HCM group (30 +/- 10 cm/sec vs 43 +/- 7 cm/sec; p < 0.05). In addition, the reverse flow velocity at atrial contraction in the PV was lower in the DCM group than in the HCM group (19 +/- 8 cm/sec vs 37 +/- 8 cm/sec; p < 0.01). These findings were associated with poorer LA systolic function in the DCM group (LAA-A, 35 +/- 13 cm/sec vs 60 +/- 11 cm/sec; LAA-EF, 37% +/- 12% vs 55% +/- 15%, p < 0.05, respectively). Our data suggest that a restrictive transmitral flow pattern develops more easily in DCM than in HCM because LA dysfunction is present in DCM, and that LA contractility plays an important role in determining the atrial contraction wave of transmitral and PV flows with elevated LA pressure.

Atrial Function, Left↗

Comparison of the therapeutic effects of the beta-blocking agent bisoprolol and the calcium-blocking agent diltiazem in patients with heart failure due to dilated cardiomyopathy.

Beta-blocking agents reduce mortality and improve symptoms in patients with dilated cardiomyopathy (DCM). There have been reports that diltiazem, a calcium-blocking agent, is also effective in such patients. We prospectively compared the effects of the beta-blocking agent bisoprolol with those of the calcium-blocking agent diltiazem in 18 patients (11 males and 7 females, age 14 to 68) with DCM. The 18 patients, (10 in New York Heart Association functional class III and 8 in class IV) were randomly assigned to 2 groups. Bisoprolol was administered as the first drug in 10 patients and diltiazem was administered in 8. Cross-over to bisoprolol was also performed in 3 patients. At the end of the study, among the 13 patients who had been given bisoprolol, 9 showed a good response (efficacy rate: 69%). In contrast, only 3 of the 8 patients who received diltiazem showed a good response (efficacy rate: 37.5%). Among the patients in NYHA class III, all 7 (100%) who were treated with bisoprolol responded but only 2 of the 4 (50%) treated with diltiazem responded (p < 0.05). Among the patients in class IV, 2 of 6 (33%) responded to bisoprolol and 1 of 4 (25%) responded to diltiazem (not significant). These results suggest that diltiazem, like bisoprolol, has a beneficial effect in patients with DCM, with a greater effect in class III patients. However, we conclude that diltiazem should usually be used as a second choice to improve heart failure in DCM, and as the first medication only in those with contraindications to beta-blocking agents.

Adolescent↗

High-resolution fluorescent particle-tracking flow visualization within an intraventricular axial flow left ventricular assist device.

Flow visualization is typically applied in blood pump development to both confirm the design expectations and identify regions that may be predisposed to blood element deposition and trauma. Rotary pumps, in particular, place high demands on the technique chosen to visualize the flow given the limited visual accessibility of the flow path and the high impeller speeds. Fluorescent image-tracking velocimetry currently is used at the University of Pittsburgh Medical Center to visualize flow accurately inside of these pumps both qualitatively and quantitatively. Flow patterns under steady conditions within an intraventricular axial flow, left ventricular assist pump (prototype No. 7, SUN Medical Technology Research Corporation, Nagano, Japan) were investigated using this technique. The flow fields at the impeller-stator interface and at the pump outlet were given specific attention. This allowed the assessment of the fluid dynamics throughout the hydrodynamic design limits of the pump.

Biomechanical Phenomena↗

Effects of nicorandil on left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy.

Various evidence suggest that myocardial ischemia is a major factor in the progression of hypertrophic cardiomyopathy (HCM). In this study, we investigated the effects of nicorandil on left ventricular (LV) systolic and diastolic function in 12 symptomatic patients with HCM using echocardiography and radionuclide angiography. Nicorandil (6 mg), when administered intravenously, produced no significant changes in any parameter, including LV filling dynamics. However, accelerated LV peak early filling velocity (0.51 +/- 0.13 to 0.59 +/- 0.14 m/sec, p < 0.01), and reduced peak velocity in atrial contraction (0.54 +/- 0.17 to 0.50 +/- 0.15 m/sec, p < 0.05) were observed by Doppler echocardiography after 4 weeks of oral administration of 10 mg nicorandil 3 times daily. This oral administration did not affect heart rate, blood pressure, LV outflow gradient, or LV systolic function. The same favorable results were observed in a wall motion analysis with radionuclide angiography: peak filling rate (PFR) in global LV (3.21 +/- 0.76 to 3.52 +/- 0.87 end-diastolic volume (EDV)/sec, p < 0.02), and apical (4.73 +/- 1.18 to 5.42 +/- 1.55 EDV/sec, p < 0.01) and lateral (4.78 +/- 1.60 to 5.52 +/- 1.51 EDV/sec, p < 0.05) segments was increased, and the time to peak filling rate (TPF) in septal (245 +/- 31 to 203 +/- 40 msec, p < 0.01) and lateral (222 +/- 54 to 193 +/- 34 msec, p < 0.05) segments was reduced. These findings indicate that nicorandil has beneficial effects on LV diastolic function in HCM. These favorable effects may be due to the improvement of subendocardial ischemia.

Adult↗

[Intracranial subdural hematoma following spinal anesthesia].

We report a case of intracranial subdural hematoma following spinal anesthesia in a 28-year-old woman. Subdural hematoma is a very rare, but life-threatening complication. When a patient complains of persistent post spinal headache, one should consider the possibility of subdural hematoma and carry out a careful examination, including MRI or CT scan.

Adult↗

An experimental study on the objective measurement of accommodative amplitude under binocular and natural viewing conditions.

A high resolution optometer makes it possible to measure changes in refractive power objectively using reflected light from the fundus of the eye. There are limitations in that the subject has to see the target monocularly through a hole in the instrument. In the present study, we attempted to measure the accommodation and pupillary response with a newly developed device as a means to measure these factors in both binocular and natural viewing conditions. We compared the subjective accommodative amplitude levels obtained from the near-point distance with those of objective accommodative amplitude obtained in earlier studies using a monocular internal target. The amplitude of accommodation of the cases with binocular, natural viewing conditions was approximately 0.7 D larger than with monocular, internal target gazing. In previous studies, the difference between the subjective amplitude of accommodation and the results of the objective measurements, had been reported to be approximately 2 D, and was explained by the depth of focus. However, the difference between the subjective and objective amplitude of accommodation under binocular, natural viewing was smaller than that between the subjective and objective measurements (under monocular internal target gazing) from previous studies. This leads us to believe that besides the depth of the focus, we should consider the fact that the advantageous conditions inherent in binocular, natural viewing may increase the amplitude of accommodation. In the measurement of accommodative amplitude, the use of objective measuring methods are not affected by the subjects' subjective judgement.

Accommodation, Ocular↗