Biomedical subjects
Publications and source records attributed to T Hozumi.
Compensatory enlargement occurred in 71% of lesions in patients with acute myocardial infarction and was more common in these patients than in patients with stable effort angina pectoris. These results suggest that compensatory enlargement may be associated with plaque rupture and subsequent acute myocardial infarction.
OBJECTIVES: The purpose of this study was to determine whether hyperinsulinemia during the oral glucose tolerance test is associated with increased neointimal tissue proliferation after coronary stent implantation in nondiabetic patients. BACKGROUND: Although hyperinsulinemia induces increased vascular smooth muscle cell proliferation in experimental models, it has not been determined whether hyperinsulinemia is associated with increased neointimal tissue proliferation after coronary stent implantation. METHODS: Serial (postintervention and six-month follow-up) intravascular ultrasound (IVUS) was used to study 67 lesions treated with Palmaz-Schatz stents in 55 nondiabetic patients. Cross-sectional images within stents were taken at every 1 mm, using an automatic pullback, and a neointimal index was calculated as the ratio between the averaged neointimal area and averaged stent area. All patients underwent a 75-g oral glucose tolerance test. Plasma glucose (PG) and immunoreactive insulin (IRI) levels were measured at baseline and 1 and 2 h after the glucose load. The sum of PGs (sigmaPG) and the sum of IRIs (sigmaIRI) were calculated. Body mass index (BMI), lipid levels, and glycosylated hemoglobin levels were measured. RESULTS: There were 27 patients with normal glucose tolerance, and 28 patients with impaired glucose tolerance (IGT). The neointimal index in patients with IGT was greater than that in patients with normal glucose tolerance (42.9 +/- 14% vs. 24.9 +/- 8.3%, respectively, p < 0.0001). Linear regression analysis showed that the neointimal index at follow-up correlated well with sigmaPG (p < 0.0001), fasting IRI (p < 0.0001), sigmaIRI (p < 0.0001), triglyceride level (p = 0.018), and BMI (p < 0.0001). Multiple regression analysis revealed that sigmaIRI (p = 0.0002) and sigmaPG (p = 0.0034) were the best predictors of the greater neointimal index at follow-up. CONCLUSIONS: Serial IVUS assessment shows that hyperinsulinemia during an oral glucose tolerance test is associated with increased neointimal tissue proliferation after coronary stent implantation in nondiabetic patients.
OBJECTIVES: The study evaluated the value of coronary flow velocity measurement by transthoracic color Doppler echocardiography (TTCDE) for the noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for left anterior descending coronary artery (LAD) lesions. BACKGROUND: Recent advances in TTCDE provide coronary flow velocity measurements in the LAD under the guidance of color flow mapping. METHODS: We studied 53 patients who underwent successful PTCA for LAD lesions and follow-up coronary angiography (18 patients with restenosis [Group-R], 35 patients without restenosis [Group-N]). We searched localized color aliasing corresponding to local flow acceleration to obtain coronary flow velocity at PTCA sites in the LAD. When localized aliasing was detected, we measured coronary flow velocity at the aliasing (stenotic site) and the prestenotic site. RESULTS: Using TTCDE, it was possible to measure mean diastolic velocity (MDV) in the LAD in 41 (77%) of 53 patients (14 of 18 patients in Group-R; 27 of 35 patients in Group-N). Localized aliasing was displayed by color flow mapping in 14 (100%) of 14 patients in Group-R, and 15 (56%) of 27 patients in Group-N. Stenotic MDV in Group-R was significantly higher than that in Group-N (60.3 +/- 21.1 vs. 35.1 +/- 7.6 cm/s, p < 0.01), although prestenotic MDV did not differ between Group-R and Group-N (20.2 +/- 3.0 vs. 19.6 +/- 2.3 cm/s). There were significant differences in the prestenotic to stenotic MDV ratio between Group-R and Group-N (0.36 +/- 0.10 vs. 0.57 +/- 0.09, p < 0.001). Localized aliasing with the prestenotic to stenotic MDV ratio <0.45 as the optimal cutoff value had a sensitivity of 86% and a specificity of 93% for the presence of restenosis in LAD lesions. CONCLUSIONS: Detection of localized color aliasing and measurement of the prestenotic to stenotic MDV ratio in the LAD by TTCDE are useful in the noninvasive diagnosis of restenosis after PTCA for LAD lesions.
The use of multiplane transesophageal echocardiography has provided three-dimensional image sets of the heart from multiple two-dimensional images with high-image quality through rotation of the transducer without changing its position (rotational scanning). We discuss the methods, clinical applications, and current limitations of this three-dimensional technique.
BACKGROUND: It has been reported that early surgery should be required for patients with type A aortic intramural hematoma (IMH) because it tends to develop classic aortic dissection or rupture. However, the anatomic features of type A IMH that develops dissection or rupture are unknown. The purpose of this study was to investigate the predictors of progression or regression of type A IMH by computed tomography (CT). METHODS AND RESULTS: Twenty-two consecutive patients with type A IMH were studied by serial CT images. Aortic diameter and aortic wall thickness of the ascending aorta were estimated in CT images at 3 levels on admission and at follow-up (mean 37 days). We defined patients who showed increased maximum aortic wall thickness in the follow-up CT (n=9) or died of rupture (n=1) as the progression group (n=10). The other 12 patients, who all showed decreased maximum wall thickness, were categorized as the regression group. In the progression group, the maximum aortic diameter in the initial CT was significantly greater than that in the regression group (55+/-6 vs 47+/-3 mm, P=0.001). A Cox regression analysis revealed that the maximum aortic diameter was the strongest predictor for progression of type A IMH. We considered the optimal cutoff value to be 50 mm for the maximum aortic diameter to predict progression (positive predictive value 83%, negative predictive value 100%). CONCLUSIONS: Maximum aortic diameter estimated by the initial CT images is predictive for progression of type A IMH.
BACKGROUND: In the era of primary percutaneous transluminal coronary angioplasty (PTCA), it is important to judge whether myocardium within acute ischemic injury is viable. This study sought to investigate parameters derived from the coronary blood flow velocity spectrum immediately after primary PTCA in patients with acute myocardial infarction and to elucidate the clinical value of coronary blood flow measurement in predicting myocardial viability. METHODS AND RESULTS: Using a Doppler guidewire, we measured coronary blood flow velocity after successful completion of primary PTCA in 23 consecutive patients with acute anterior myocardial infarction. Regional wall motion was analyzed to estimate anterior wall motion score index (A-WMSI) by echocardiography before PTCA and 1 month after the onset of symptoms. Average systolic peak velocity (ASV) and deceleration time of diastolic flow velocity (DDT) significantly correlated to 1-month A-WMSI (r=-0.54, P=0.007 and r=-0.62, P=0.002, respectively), and optimal cutoff values to predict viable myocardium (defined as 1-month A-WMSI </=2.0) were 6.5 cm/s for ASV and 600 ms for DDT (sensitivity=0.79, specificity=0.89 and sensitivity=0.86, specificity=0.89, respectively). ASV and DDT also correlated weakly to the change in A-WMSI (r=0.46, P=0.03 and r=0.49, P=0.02, respectively). CONCLUSIONS: Low ASV and rapid DDT of coronary blood flow spectrum immediately after primary PTCA reflects a greater degree of microvascular damage in the risk area. Analysis of coronary blood flow spectrum immediately after primary PTCA by use of a Doppler guidewire is useful in predicting recovery of regional left ventricular function.
Four major hemodynamic subsets from cardiac index (CI) and mean pulmonary artery (PA) wedge pressure with a PA catheter usually reflect clinical status and prognosis of patients with acute myocardial infarction (AMI). Recently, a new color Doppler technique has been developed for automated cardiac output measurements (ACOM). Color Doppler echocardiography also provides noninvasive estimation of PA wedge pressure from pulmonary venous (PV) flow analysis. This study evaluates the value of ACOM and PV flow analysis by color Doppler echocardiography for the assessment of hemodynamic subsets in patients with AMI. We performed ACOM and PV flow analysis by color Doppler echocardiography in 55 patients with AMI who underwent hemodynamic assessment with a PA catheter. From both noninvasive and invasive methods, we classified hemodynamic subsets as follows: subset I: normal hemodynamics (CI >2.2 L/min/m2, PA wedge pressure < or =18 mm Hg); subset II: pulmonary congestion (CI >2.2 L/min/m2, PA wedge pressure >18 mm Hg); subset III: peripheral hypoperfusion (CI < or =2.2 L/min/m2, PA wedge pressure < or =18 mm Hg); and subset IV: pulmonary congestion and peripheral hypoperfusion (CI < or =2.2 L/min/m2, PA wedge pressure >18 mm Hg). Doppler assessment of hemodynamic subsets was possible in 50 of 55 patients (91%). CI from ACOM correlated well with that from the thermodilution method (r = 0.94) with close agreement. There was a good correlation between the systolic fraction (systolic velocity-time integral expressed as a fraction of the sum of systolic and diastolic velocity-time integrals) of PV flow and PA wedge pressure measured from cardiac catheterization (r = -0.83). When we determined the value of 45% in the systolic fraction as the cut-off point in predicting >18 mm Hg in PA wedge pressure, there was 90% (45 of 50 patients) agreement between noninvasive and invasive hemodynamic subsets. Thus, ACOM and PV flow analysis by color Doppler echocardiography is useful in the noninvasive assessment of hemodynamic subsets in patients with AMI.
STUDY DESIGN: Retrospective examination of 37 patients with metastatic spinal tumors treated with intraoperative radiation therapy. OBJECTIVE: To propose a new technique for local control of metastatic spinal tumors. SUMMARY OF BACKGROUND DATA: No reports of intraoperative radiation therapy for metastatic spinal tumors have been published as of the time of this writing. METHODS: Between December 1992 and April 1996, intraoperative radiation therapy was performed in 37 patients with spinal metastasis. In all but one patient, the spinal cord was protected during intraoperative radiation therapy by a lead shield to prevent radiation myelopathy. In addition to intraoperative radiation therapy, 22 of the 37 patients received external radiation therapy, either before or after their operation. Although the authors had recommended a dose of approximately 30 Gy of external radiation therapy after wound suture removal to patients who did not receive preoperative radiation therapy, the remaining 15 patients did not receive external radiation therapy, either by choice or because they received alternative therapy. Adjuvant chemotherapy for various cancers was administered to 9 of the 37 patients, including 4 of the aforementioned 15. RESULTS: All patients attained clinical improvement in pain, neurologic function status, or both, with no evidence of local recurrence. Radiation myelopathy developed in the one patient whose spinal cord was not protected during intraoperative radiation therapy. Eleven patients experienced metastasis in vertebrae that were not surgically treated. CONCLUSION: Intraoperative radiation therapy appears to achieve good palliation and may be useful for local control of spinal metastases.
BACKGROUND: prospective studies have demonstrated that a predominance of small, dense LDL particles (pattern B) precedes the clinical onset of coronary heart disease. Prevalence and characteristics of subjects with this LDL size abnormality were studied in young, nonobese, Japanese normolipidemic men. METHODS AND RESULTS: LDL peak particle diameter (PPD) was measured by continuous disc polyacrylamide gel electrophoresis in 223 nonobese normolipidemic men aged 18-20 years (mean+/-S.D. body mass index: 21.9+/-3.7 kg/m2, total cholesterol: 180+/-29 mg/dl, triglyceride: 62+/-34 mg/dl, HDL cholesterol: 58+/-12 mg/dl). Men with small LDL (PPD < 25.8 nm) were found in only 5.4% (n=12) whereas 197 men (88.3%) had a preponderance of large LDL (PPD 26.3 nm). As compared with men in a top tertile (PPD 27.5 nm) those in a low tertile (PPD < 26.9 nm) had higher serum levels of LDL cholesterol (120+/-31 vs 104+/-24 mg/dl), triglyceride (72+/-39 vs 49+/-16 mg/dl) and apolipoprotein (apo) B (84+/-21 vs 68+/-14 mg/dl), and lower HDL cholesterol (54+/-10 vs 60+/-12 mg/dl). They also had greater body mass index (23.2+/-4.6 vs 20.9+/-3.1 kg/m2) and percent body fat (21.5+/-7.7 vs 17.5+/-4.9%). LDL-PPD was positively correlated with HDL cholesterol (R=0.20, P=0.002) and was negatively correlated with apoB (R=0.34, P < 0.001), triglyceride (R=0.32, P < 0.001). percent body fat (R=0.26, P < 0.001), body mass index (R=0.24, P < 0.001), fat mass (R=0.23, P=0.001), total cholesterol (R=0.20, P=0.002). In multiple regression analysis, apoB, triglyceride, HDL cholesterol, apoAI and percent body fat explained 18% of LDLPPD variability. CONCLUSION: even in young, nonobese, normolipidemic men, LDL size appears to be associated with triglyceride-rich lipoprotein metabolism and body fat.
OBJECTIVES: This study investigates the correlation between deceleration time of diastolic pulmonary venous flow (PV-DT) and of early filling mitral flow (LV-DT), and pulmonary capillary wedge pressure (PCWP) in patients with acute myocardial infarction (AMI). BACKGROUND: An earlier study suggests that Doppler-derived LV-DT provides an accurate means of estimating PCWP in postinfarction patients with left ventricular systolic dysfunction. Furthermore, recent studies have suggested that PCWP correlates better with PV-DT than with LV-DT. However, the value of PV-DT and LV-DT for assessment of PCWP in patients with AMI has not been evaluated. METHODS: In 141 consecutive patients with AMI, we measured PV-DT and LV-DT by Doppler echocardiography, and compared these variables with PCWP measured using a Swan-Ganz catheter. RESULTS: There was a weak negative correlation between the LV-DT and PCWP (r = -0.54). Although the sensitivity of < or =130 ms in LV-DT in predicting > or =18 mm Hg in PCWP was high (86%), its specificity was low (59%). On the other hand, a very close negative correlation was found between PV-DT and PCWP (r = -0.89). The sensitivity and specificity of < or =160 ms in PV-DT in predicting > or =18 mm Hg in PCWP were 97% and 96%, respectively. CONCLUSIONS: In patients with AMI, Doppler-derived PV-DT showed a stronger correlation with PCWP than LV-DT.
A 72-year-old woman was found to have massive bilateral adrenal masses on computed tomography and was diagnosed with 21-hydroxylase deficiency (21-OHD) based on endocrinological findings. Physical examination revealed no abnormalities except markedly short stature. She was diagnosed with 21-OHD because she had an elevated serum 17alpha-hydroxyprogesterone (17-OHP) level which significantly decreased in response to dexamethasone. Percutaneous CT-guided biopsy and later autopsy confirmed that the adrenal masses were due to adrenocortical hyperplasia. Analysis of the CYP21 gene revealed that the patient was a compound heterozygote for the Ile-172-->Asn mutation in exon 4 and the 8-bp deletion in exon 3. Simple virilizing 21-OHD (SV) would be predicted from this genotype. She had few symptoms associated with 21-OHD except for markedly short stature, but the serum 17-OHP level was higher than that of typical nonclassical form of 21-OHD and near to that of typical SV. This finding was confirmed by analysis of the CYP21 gene. From these results, we report that when adrenal masses are incidentally detected, 21-OHD should be ruled out to avoid excessive examination and surgery on the suspicion of adrenal carcinoma.
OBJECTIVE: We studied whether increased urinary transferrin excretion rates (TERs) (urinary transferrin-to-urinary creatinine ratio > or = 107 micrograms/mmol, which is the sum of an average and 2 SDs in 431 healthy nondiabetic individuals) would predict the development of microalbuminuria (urinary albumin-to-urinary creatinine ratio > or = 2.8 mg/mmol) in patients with type 2 diabetes and normal urinary albumin excretion rates (AERs) (albumin-to-creatinine ratio < 2.8 mg/mmol). We also studied the influence of blood pressure, glycemic control, and serum levels of lipids and apolipoproteins on the later development of microalbuminuria. RESEARCH DESIGN AND METHODS: In 77 diabetic patients with normal AER, AER and TER were measured at baseline and after 24 months of follow-up. Blood pressure, glycemic control, and serum levels of lipids and apolipoproteins were measured at 1- to 2-month intervals during the follow-up period. RESULTS: Of the 16 patients who initially had increased TER, 5 (31%) developed microalbuminuria. In contrast, of the 61 who initially had normal TER, 4 (7%) developed microalbuminuria (P = 0.016). At baseline, no difference was found in age, sex, diabetes duration, diabetic medications, prevalence of hypertension, blood pressure, HbA1c levels, or serum lipid and apolipoprotein concentrations between the two group of patients with normal and increased TER. There was also no difference in duration of hypertension and prevalence of users of ACE inhibitors between two subgroups of hypertensive patients with normal and increased TER. During the 24 month follow-up period, those whose condition progressed to microalbuminuria had increased serum levels of triglycerides (1.87 +/- 0.49 vs. 1.29 +/- 0.64 mmol/l, P = 0.003) and apolipoprotein B (114 +/- 20 vs. 102 +/- 24 mg/dl, P = 0.05) and tended to have increased HbA1c levels (7.7 +/- 1.0 vs. 7.1 +/- 1.1%, P = 0.10) compared with those in whom microalbuminuria did not develop. Blood pressure, however, did not differ. In multivariate stepwise logistic regression analysis, the association between increased TER at baseline and subsequent development of microalbuminuria was significant (odds ratio 7.04 [95% CI 1.02-48.5], P = 0.04). CONCLUSIONS: In patients with type 2 diabetes and normal AER, increased TER may predict the development of microalbuminuria and abnormalities in triglyceride-rich lipoprotein metabolism, and poor glycemic control may be associated with this progression.
Recognition of the involved lesions is extremely important in mitral valve repair for infective endocarditis. Transesophageal echocardiography (TEE) is more sensitive for the detection of lesions than transthoracic echocardiography, but localization of the lesions is sometimes difficult by TEE. Three-dimensional (3D) TEE provides images of the mitral valve similar to the view from the left atrium. This study evaluated the value of 3D echocardiography for the diagnosis of involved lesions in 12 patients who underwent surgery for mitral regurgitation due to infective endocarditis. The location of the lesion in the mitral valve was classified as the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet, respectively. In all patients, the involved sites were confirmed at operation. The sensitivities of 3D TEE for detecting the lesions at the medial, central and lateral portions of the anterior leaflet, and the medial, middle and lateral scallops of the posterior leaflet were 100%, 78% and 67%, and 100%, 100% and 100%, respectively. The specificities were 90%, 100% and 78%, and 100%, 100% and 100%, respectively. The lesions diagnosed by 3D TEE coincided with lesions confirmed at operation in 23 (92%) of 25 lesions. 3D TEE is useful for the assessment of the involved lesion of the mitral valve in patients with infective endocarditis.
Rhus javanica, a medicinal herb, has been shown to exhibit oral therapeutic anti-herpes simplex virus (HSV) activity in mice. We purified two major anti-HSV compounds, moronic acid and betulonic acid, from the herbal extract by extraction with ethyl acetate at pH 10 followed by chromatographic separations and examined their anti-HSV activity in vitro and in vivo. Moronic acid was quantitatively a major anti-HSV compound in the ethyl acetate-soluble fraction. The effective concentrations for 50% plaque reduction of moronic acid and betulonic acid for wild-type HSV type 1 (HSV-1) were 3.9 and 2.6 microgram/ml, respectively. The therapeutic index of moronic acid (10.3-16.3) was larger than that of betulonic acid (6.2). Susceptibility of acyclovir-phosphonoacetic acid-resistant HSV-1, thymidine kinase-deficient HSV-1, and wild-type HSV type 2 to moronic acid was similar to that of the wild-type HSV-1. When this compound was administered orally to mice infected cutaneously with HSV-1 three times daily, it significantly retarded the development of skin lesions and/or prolonged the mean survival times of infected mice without toxicity compared with the control. Moronic acid suppressed virus yields in the brain more efficiently than those in the skin. This was consistent with the prolongation of mean survival times. Thus, moronic acid was purified as a major anti-HSV compound from the herbal extract of Rhus javanica. Mode of the anti-HSV activity was different from that of ACV. Moronic acid showed oral therapeutic efficacy in HSV-infected mice and possessed novel anti-HSV activity that was consistent with that of the extract.
Assessment of segmental wall motion is one of the most challenging tasks in echocardiography. One major limitation is impairment of echocardiographic regional wall motion by incomplete endocardial definition. The newly developed tissue harmonic imaging method may improve the detection of left ventricular endocardial border. This study examined the impact of native tissue harmonic imaging on endocardial border definition. Fundamental and harmonic imaging were compared for detecting the endocardial border in 96 segments of 16 patients (age 54 +/- 8 years). Visualization of endocardial border was better with harmonic imaging than with fundamental mode in 49% (47 of 96 segments). Thus, tissue harmonic imaging has a significant impact on endocardial border definition.
The color Doppler echocardiographic technique has been developed for automated cardiac flow measurement (ACM). This study evaluated the effect of imaging parameters on stroke volume measurement. Cardiac output derived from the ACM method was compared with that obtained from pulsed wave Doppler in 36 patients (26 men and 10 women, mean age 54 +/- 8 years) in whom clear two-dimensional and color Doppler images of the left ventricular outflow tract were obtained. The effects of frame rate, color gain and moving target indicator (MTI) filter on cardiac output were evaluated in 13 patients (8 men and 5 women, mean age 49 +/- 6 years). Using ACM at a frame rate of 30 Hz, optimal color gain setting and high-frequency MTI filter (cutoff frequency: 915 Hz), there was an excellent correlation in cardiac output between the ACM and pulsed wave Doppler methods (stroke volume: r = 0.91, SEE = 0.32 l/min). Using ACM at a frame rate of 30, 22 and 15 Hz, the differences in stroke volume were 4.4%, 5.2% and 8.6%, respectively. When color gain was reduced, left ventricular stroke volume reduction was 12.1% (-2 dB), 18.9% (-4 dB). In contrast, there was no significant change in stroke volume measurement when color gain was increased. There was a significant decrease in stroke volume using the low-frequency MTI filter [cutoff frequency: 467 Hz (-35.6%)] and medium-frequency MTI filter [cutoff frequency: 703 Hz (-13.4%)]. Color Doppler imaging parameters are extremely important for automated assessment of cardiac output.
Recent development of an automated contour tracking (ACT) method using the energy minimization principle provides automated edge detection and tracking of the endocardial boundary of the left ventricle, without tracing a region of interest. This study determined whether left ventricular filling indexes obtained from the ACT method provide a reliable estimate of left ventricular diastolic filling. Fourteen patients were examined by the ACT method and equilibrium radionuclide ventriculography. The volume-time wave form for ACT measurements was obtained from the 4-chamber views. Peak filling rate and time to peak filling rate measured by the ACT method were compared with those determined by radionuclide ventriculography. Peak filling rate and time to peak filling rate by the ACT method were closely correlated with those determined by radionuclide ventriculography (peak filling rate: r = 0.88, y = 0.71x + 0.36, SEE = 0.54 ml/end-diastolic volume/sec, time to peak filling rate: r = 0.89, y = 0.72x + 30.0, SEE = 0.02 msec, respectively) The ACT method is useful for the assessment of left ventricular diastolic filling.
We evaluated the capability of extracted 3-dimensional images obtained by multiplane transesophageal echocardiography in the evaluation of nonplanarity and area change of the mitral annulus in patients with an annuloplasty ring. This method is feasible in the evaluation of nonplanarity and area change of mitral annulus in patients with an annuloplasty ring.