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Biomedical subjects

M Uematsu

Publications and source records attributed to M Uematsu.

At least 73 records · Page 4Linked to original sources
PubMed1998

Plasma brain natriuretic peptide levels increase in proportion to the extent of right ventricular dysfunction in pulmonary hypertension.

OBJECTIVES: This study sought to investigate the influence of right ventricular (RV) hemodynamic variables and function on the secretion of brain natriuretic peptide (BNP) in patients with isolated RV overload. BACKGROUND: Plasma BNP is known to increase in proportion to the degree of left ventricular (LV) overload. However, whether BNP secretion is also regulated in the presence of RV overload remains unknown. METHODS: Plasma BNP and atrial natriuretic peptide (ANP) levels in the pulmonary artery were measured in 44 patients with RV overload: 18 with RV volume overload (RVVO) due to atrial septal defect and 26 with RV pressure overload (RVPO) due to primary or thromboembolic pulmonary hypertension. Right heart catheterization was performed in all patients. RV and LV ejection fraction, myocardial mass and volume of the four chambers were determined by using electron beam computed tomography. RESULTS: Although both plasma BNP and ANP levels were significantly elevated in patients with RV overload compared with values in control subjects, plasma BNP and the BNP/ANP ratio were significantly higher in patients with RVPO than with RVVO (BNP 294 +/- 72 vs. 48 +/- 14 pg/ml; BNP/ANP 1.6 +/- 0.2 vs. 0.8 +/- 0.2, both p < 0.05). Plasma BNP correlated positively with mean pulmonary artery pressure (r = 0.73), total pulmonary resistance (r = 0.79), mean right atrial pressure (r = 0.79), RV end-diastolic pressure (r = 0.76) and RV myocardial mass (r = 0.71); it correlated negatively with cardiac output (r = -0.33) and RV ejection fraction (r = -0.71). Plasma BNP significantly decreased from 315 +/- 120 to 144 +/- 54 pg/ml with long-term vasodilator therapy (total pulmonary resistance decreased from 23 +/- 4 to 15 +/- 3 Wood U). CONCLUSIONS: Plasma BNP increases in proportion to the extent of RV dysfunction in pulmonary hypertension.

Adult↗
PubMed1998

Peak negative myocardial velocity gradient in early diastole as a noninvasive indicator of left ventricular diastolic function: comparison with transmitral flow velocity indices.

OBJECTIVES: We sought to assess the clinical significance of peak negative myocardial velocity gradient (MVG) in early diastole as a noninvasive indicator of left ventricular (LV) diastolic function. BACKGROUND: Peak systolic MVG has been shown useful for the quantitative assessment of regional wall motion abnormalities, but limited data exist regarding the diastolic MVG as an indicator of LV diastolic function. METHODS: Peak negative MVG was obtained from M-mode tissue Doppler imaging (TDI) in 43 subjects with or without impairment of systolic and diastolic performance: 12 normal subjects, 12 patients with hypertensive heart disease (HHD) with normal systolic performance and 19 patients with dilated cardiomyopathy (DCM), and was compared with standard Doppler transmitral flow velocity indices. In a subgroup of 30 patients, effects of preload increase on these indices were assessed by performing passive leg lifting. In an additional 11 patients with congestive heart failure at the initial examination, the measurements were repeated after 26+/-16 days of volume-reducing therapy. RESULTS: Peak negative MVG was significantly depressed both in HHD (-3.9+/-1.3/s, p < 0.01 vs. normal=-7.7+/-1.5/s) and DCM (-4.4+/-1.4/s, p < 0.01 vs. normal). In contrast, transmitral flow indices failed to distinguish DCM from normal due to the pseudonormalization. Transmitral flow velocity indices were significantly altered (peak early/late diastolic filling velocity [E/A]=1.1+/-0.5 to 1.5+/-0.7, p < 0.01; E deceleration time=181+/-41 to 153+/-38 ms, p < 0.01), while peak negative MVG remained unchanged (-5.3+/-2.2 to -5.3+/-2.0/s, NS) by leg lifting. Volume-reducing therapy resulted in the apparent worsening of the transmitral flow velocity pattern toward abnormal relaxation, as opposed to peak negative MVG, which improved by the therapy (p < 0.05). CONCLUSIONS: Peak negative MVG derived from TDI may be a noninvasive indicator of LV diastolic function that is less affected by preload alterations than the transmitral flow velocity indices, and thereby could be used for the follow-up of patients with nonischemic LV dysfunction presenting congestive heart failure.

Adult↗
PubMed1998

Impact of presence of abnormal wall motion on echocardiographic determination of left ventricular function with automated boundary detection technique: re-evaluation.

It is still unclear whether echocardiography with an automated boundary detection technique (ABD) can accurately determine the left ventricular (LV) volume and function particularly in the presence of LV wall asynergy. We intended to re-evaluate the reliability and application of the ABD, which was based on the acoustic quantification technique (Sonos 2500, Hewlett Packard) for the LV volume measurement in patients without or with LV wall asynergy. A total of 80 patients (mean age 56 years) who underwent left ventriculography (LVG) were divided into two groups. The group A consisted of 29 patients with normal LV wall motion and the group B consisted of 51 patients with generalized or regional LV wall motion abnormality. In group A patients, the LV end-diastolic volume (LVEDV) was 96 +/- 25 ml by ABD and 112 +/- 33 ml by LVG and those of LV end-systolic volume (LVESV) were 44 +/- 14 ml by ABD and 48 +/- 17 ml by LVG, thus resulting in the underestimation of LV volume by 12% in average. Under these conditions, the LV ejection fraction (LVEF) by ABD, 54 +/- 8%, correlated well with that by LVG, 58 +/- 7%. Although underestimation of LV volume by 17% in average also occurred in groups B (N.S.), LVEF was found to correlate well with that by LVG; 27 +/- 8% vs 30 +/- 11% (r = 0.87, SEE = 3.1%) for 21 patients with the generalized LV asynergy; 39 +/- 10% vs 39 +/- 12% (r = 0.86. SEE = 3.3%) for 30 patients with the regional LV asynergy. These results demonstrate the feasibility of the ABD in determining the LVEF, although underestimation can occur in measuring the absolute LV volume in patients with or without LV asynergy.

Case-Control Studies↗
PubMed1998

A modified human ureter graft tanned by a new crosslinking agent polyepoxy compound for small diameter arterial substitutions: an experimental preliminary study.

The effectiveness of human ureter grafts tanned by polyepoxy compound for small diameter arterial substitution was examined in 8 carotid arteries of rabbits, followed by an observation period of either 1 month (n = 6) or 6 months (n = 2). In this model there was no evidence of rejection, aneurysm formation, or infection. The modified human ureter showed excellent patency in all cases as well as excellent function, and the histological evaluation revealed monolayer endothelial-like cells covering all of the surface of the graft as was expected. No intimal hyperplasia was demonstrated at either anastomotic site. This study suggests that our newly designed polyepoxy compound fixed human ureter could serve as a satisfactory blood conduit with good long-term patency for substitution.

Anastomosis, Surgical↗
PubMed1998

Secretion patterns of brain natriuretic peptide and atrial natriuretic peptide in patients with or without pulmonary hypertension complicating atrial septal defect.

UNLABELLED: BACKGROUND This study was designed to investigate plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in patients with atrial septal defect (ASD), whose right ventricular loading patterns vary from simple volume overloading to both volume and pressure overloading. METHODS AND RESULTS: Plasma ANP and BNP in the pulmonary artery were measured in 31 adult patients with ASD and 11 control subjects. On the basis of the presence of pulmonary hypertension (PH, mean pulmonary arterial pressure >20 mm Hg), patients with ASD were divided into two groups, patients without PH (group 1, n = 21) and those with PH (group 2, n = 10). Cardiac catheterization was performed to measure mean pulmonary arterial pressure and pulmonary blood flow. Plasma ANP was significantly higher in both group 1 and group 2 than in the control group. Plasma BNP and BNP to ANP (BNP/ANP) ratio were significantly higher in group 2 than in the control group, although they were not significantly elevated in group 1. Plasma ANP positively correlated with the degree of pulmonary blood flow (r = 0.54, p < 0.01), whereas plasma BNP positively correlated with the magnitude of mean pulmonary arterial pressure (r= 0.73, p < 0.001). BNP/ANP >1 was a powerful marker for the presence of PH (sensitivity 90%, specificity 90%). CONCLUSIONS: Plasma ANP levels were elevated in adult patients with ASD regardless of PH. In contrast, plasma BNP levels were elevated in proportion to the severity of PH complicating ASD. Thus BNP and ANP may represent differing aspects of cardiac response to right ventricular overload in patients with ASD.

Adult↗
PubMed1998

Comparison of automatic boundary detection and manual tracing technique in echocardiographic determination of left atrial volume.

Previous reports have indicated that echocardiography with automatic boundary detection (ABD) is useful for the noninvasive estimation of left ventricular volume. However, few data exist regarding the measurement of left atrial (LA) volume, which also provides pivotal information in the clinical setting. Therefore, the feasibility of LA volume measurement by ABD in comparison with the manual tracing using modified Simpson's method (SM) was evaluated. Fifty-nine patients with coronary artery-disease with sinus rhythm were examined. Using ABD, a region of interest was set around the LA border and mitral annulus from an apical four-chamber view. The maximal and minimal LA volume (Vmax and Vmin) were measured from the volume waveform. Using the SM, the maximal and minimal LA volume were measured by the manual tracing on frozen frames at the apical four-chamber view. The ABD displayed a curve of LA volume change that consisted of passive emptying, diastasis, and active emptying phases during the left ventricular diastolic period. Under these conditions, the Vmax and Vmin were 43.7 +/- 11.2 ml and 21.1 +/- 7.6 ml, respectively, yielding the volume change of 22.6 +/- 6.0 ml. By the SM, Vmax and Vmin were 43.1 +/- 9.9 ml (r = 0.94, p < 0.0001, y(ABD) = 0.91x (SM) + 3.6) and 22.0 +/- 9.0 ml (r = 0.91, p < 0.0001, y = 0.94x + 0.7), respectively, and the volume change was 22.8 +/- 6.1 ml (r = 0.82, p < 0.0001, y = 0.84x + 3.8). These results indicate that the ABD from the apical four-chamber approach could provide an accurate estimation of LA volume change, suggesting the potential value of this method in assessing LA function, although some technical difficulties need to be further overcome.

Adult↗
PubMed1998

Two-step approach for the operation of male breast cancer: report of a case at high risk for surgery.

We report herein the rare case of a 61-year-old man with a history of dissecting aortic aneurysm as well as right breast cancer. He complained of abdominal pain due to a progress of aortic dissection in preparation for the radical operation for breast cancer. Blood pressure was initially controlled and he was administered a simple mastectomy under local anesthesia. One month after the first operation, a radical operation for breast cancer was successfully performed. The tumor was in stage II, and two years after the operation, the patient remained free of recurrent disease. This two-step approach for the operation of male breast cancer may be used as a treatment of breast cancer if a patient is too frail for normal surgery.

Adenocarcinoma↗
PubMed1998

[Color Doppler signal enhancement with SH/TH-508 in pancreatic tumors].

In this report, we showed the efficacy of a new contrast agent (SH/TA-508, Schering AG, Germany) for color Doppler imaging of the pancreatic tumors. In pancreatic ductal cancer, no enhancement of the lesion was observed, but vascular invasion by cancer became to be easily evaluated. On the other hand, hypervascular tumors such as islet cell tumor and cystadenocarcinoma, were increased in color Doppler signals of vessels by SH/TA-508. We concluded that SH/TA-508 was useful for evaluating the vascular invasion by pancreatic cancer as well as vascularity of hypervascular mass and solid component of cystic neoplasma.

Adenoma, Islet Cell↗
PubMed1998

Impaired regional fatty acid uptake and systolic dysfunction in hypertrophied right ventricle.

UNLABELLED: Little information is available regarding the determinants of systolic contractile function of the hypertrophied right ventricle (RV). The purpose of this study was to clarify the relationship between myocardial metabolism and contractile function in the hypertrophied RV due to pulmonary hypertension (PH). METHODS: Iodine-123-labeled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) and 99mTc-sestamibi (MIBI) SPECT were performed to calculate the RV-to-left ventricle (LV) tracer uptake ratio (RV/LV) in 21 patients with PH (6 with primary PH and 15 with chronic thromboembolic PH). The patients also underwent electron-beam CT to assess RV ejection function (RVEF) and percentage systolic wall thickening (%SWT) and right heart catheterization to measure mean pulmonary arterial pressure (mPAP). RESULTS: There were significant positive correlations between mPAP and MIBI-RV/LV (r = 0.89, p < 0.001) and between mPAP and BMIPP-RV/LV (r = 0.86, p < 0.001). However, 8 patients showed lower BMIPP-RV/LV than MIBI-RV/LV, indicating the impairment of myocardial fatty acid uptake in the RV. These patients had lower RVEF and %SWT compared to those with normal myocardial fatty acid uptake (RVEF = 28% +/- 10% compared to 40% +/- 9% and %SWT = 33% +/- 27% compared to 74% +/- 30%, respectively; p < 0.05 for both comparisons). Although mPAP did not differ between the groups, the RVEF-mPAP and %SWT-mPAP regression lines drawn from the patients with impaired myocardial fatty acid uptake were located below the lines from the patients with normal myocardial fatty acid uptake, suggesting disproportionately decreased RV myocardial contractility for a given mPAP in patients with impaired myocardial fatty acid uptake. The patients with the impaired fatty acid uptake in the RV had a significantly higher death rate (log-rank test, p < 0.05). CONCLUSION: The results from this preliminary study suggest that myocardial fatty acid uptake is impaired in the failing hypertrophied RV due to PH.

Fatty Acids↗
PubMed1997

Shortening of Doppler-derived deceleration time of early diastolic transmitral flow in the presence of pulmonary hypertension through ventricular interaction.

Deceleration time (DT) of the early transmitral flow velocity has recently been highlighted as a simple, noninvasive indicator of pulmonary arterial wedge pressure. In patients with pulmonary hypertension without left-sided heart disease, however, increased right ventricular pressure may result in an abnormal ventricular septal motion, which may impact on left ventricular (LV) early diastolic filling. We sought to determine if DT may be influenced by the severity of pulmonary hypertension in patients without left-sided heart disease. Doppler-derived transmitral flow and hemodynamic parameters were simultaneously assessed in 26 patients with pulmonary hypertension (primary pulmonary hypertension = 11; chronic thromboembolism = 15). Transmitral Doppler variables including DT were correlated with hemodynamics and LV deformity index measured in early diastole with 2-dimensional echocardiography. DT significantly correlated with the total pulmonary resistance (r = -0.70, p <0.001). Multivariate analysis revealed that DT was independently determined by total pulmonary resistance, but not by pulmonary arterial wedge pressure, heart rate, or patient's age in our study population. DT showed a correlation with LV deformity index (r = -0.74, p <0.001). These results indicate that DT may shorten in association with the severity of pulmonary hypertension and that the shortened DT in pulmonary hypertension may be attributable to right ventricular pressure overload which causes geometric changes.

Adult↗
PubMed1997

Usefulness of myocardial velocity gradient derived from two-dimensional tissue Doppler imaging as an indicator of regional myocardial contraction independent of translational motion assessed in atrial septal defect.

Independence of myocardial velocity gradient from translational motion of the heart was tested by comparing normal subjects and patients with atrial septal defect. Myocardial velocity gradient obtained from patients fit within the normal range, even though the translation of the left ventricle was exaggerated in patients, demonstrating the translation independence of myocardial velocity gradient in clinical settings.

Adolescent↗
PubMed1997

Attenuated inhibition of adrenergic contraction by nitric oxide in injured guinea pig femoral artery.

The present study aimed to examine the altered modulation of adrenergic contraction by nitric oxide and sensory neuropeptides in balloon-injured muscular artery. A guinea pig femoral artery (GPFA) was injured by a newly developed silastic microballoon catheter. The contralateral GPFA served as the control. The studied GPFAs consisted of six groups; control (C) and injured (I) GPFA, isolated at 0 days, and 2 and 8 weeks after injury (C0, I0, C2, I2, C8, and I8). Isometric tension was measured in the presence of indomethacin (10(-5) M), to exclude effects of cyclooxygenase-generated eicosanoids. Endothelial removal with the catheter was confirmed by histological examination. In each group, except for 10, NG-nitro-I-arginine methyl ester (L-NAME, 10(-6) M) induced significant augmentation of perivascular nerve stimulation (PNS)-evoked adrenergic contraction, which was blocked by L-arginine (3 x 10(-4) M). The degree of L-NAME augmentation in I8 was significantly smaller than that in C8 and I2. Capsaicin (10(-6) M) did not significantly affect PNS-contraction in any group, indicating that there was no sensory neuropeptide involvement in this contraction. In I8, acetylcholine (10(-6) M)-induced relaxation after noradrenaline (10(-5) M)-precontraction was significantly smaller than that seen in the other groups, except for I0, which was lacking in acetylcholine-induced relaxation. Histologically, injured GPFAs showed progressive intimal thickening. The present findings thus showed attenuated nitric oxide-mediated inhibition of adrenergic contraction, accompanying intimal thickening, in balloon-injured muscular artery, 8 weeks after injury.

Acetylcholine↗
PubMed1997

Impaired left ventricular myocardial metabolism in patients with pulmonary hypertension detected by radionuclide imaging.

To assess whether left ventricular myocardial metabolism is affected by the presence of right ventricular pressure overload, we performed 123I-beta-methyl-iodophenyl pentadecanoic acid (123I-BMIPP) and 99Tc(m)-sestamibi (99Tc(m)-MIBI) single photon emission tomography in 24 patients with pulmonary hypertension and in 10 control subjects. The left ventricle was divided into six regions using a short-axis tomogram at the mid-ventricular level. The relative regional uptake (RRU, %) was determined for each region as the ratio of the regional uptake per pixel to the maximum uptake in the six regions. Right heart catheterization was performed to obtain mean pulmonary arterial pressure. 123I-BMIPP uptake in the septum and the adjacent myocardium of the left ventricle was lower in patients with pulmonary hypertension than in control subjects (septal RRU, 75 +/- 6 vs 85 +/- 4%; anteroseptal RRU, 76 +/- 6 vs 86 +/- 3%; posteroseptal RRU, 75 +/- 4 vs 84 +/- 4%; P < 0.001). The reduction in 99Tc(m)-MIBI uptake was confined to the septum in patients with pulmonary hypertension (79 +/- 5 vs 85 +/- 5%; P < 0.05). Interestingly, the septal RRU of 123I-BMIPP and the sum of the septal, anteroseptal and posteroseptal RRUs of 123I-BMIPP were negatively correlated with mean pulmonary arterial pressure (r = -0.70 and -0.55, respectively; P < 0.01). In conclusion, myocardial metabolism in the interventricular septum and the adjacent regions of the left ventricle may be impaired in proportion to the degree of pulmonary hypertension.

Adult↗
PubMed1997

[Prognostic factors of cervical carcinoma treated with postoperative radiotherapy].

We analyzed 119 patients with cervical carcinoma treated by postoperative radiotherapy from 1983 to 1993. Five- and 10-year survival rates of all patients were 77% and 67%, respectively. The 10-year survival rates for stage I (54 patients) and stage II (65 patients) were 76% and 58%, respectively. Ten-year survival rate for patients with both deep stromal invasion and lymph node metastasis was 37% which was much lower than in those without them (more than 90 %), indicating that they seemed to be factors related to poor prognosis. The results of multivariate analysis showed that the number of metastatic lymph nodes was the most important prognostic factor. Leg edema and intestinal and urinary insufficiency as late complications of postoperative radiotherapy occurred at low incidences and were well tolerated.

Adult↗
PubMed1997

[Surgical treatment of primary pulmonary malignant lymphoma: a report of successful case].

A 73-year-old male was admitted to our hospital because of abnormal shadow in the lung field. The pathological report of the percutaneous needle lung biopsy specimen under the CT scan was suggested lymphoma (lymphomatoid granulomatosis suspected), and the right middle lobectomy was performed. Histological and immunohistochemical examinations of the operative specimen revealed B-cell type malignant lymphoma (diffuse pleomorphic lymphoma, large cell type, high grade lymphoma). Primary pulmonary malignant lymphoma is a rare disorder, and it is difficult utilized to distinguish between true malignant lymphoma and lymphomatoid granulomatosis, or pseudolymphoma. Anyway, the first choice of the treatment is surgical excision, because of its satisfactory prognosis.

Aged↗