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Biomedical subjects

S Kuribayashi

Publications and source records attributed to S Kuribayashi.

At least 37 records · Page 2Linked 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

Subtraction CT angiography with controlled-orbit helical scanning for detection of intracranial aneurysms.

PURPOSE: Our goal was to evaluate the utility of subtraction three-dimensional CT angiography for the detection of intracranial aneurysms. METHODS: Thirty-six patients with intracranial aneurysms were examined using newly devised controlled-orbit helical scanning and conventional angiography. Three-dimensional CT angiograms and subtraction 3-D CT angiograms were compared with conventional angiograms for their characterization of intracranial aneurysms. RESULTS: Fifty aneurysms were depicted on conventional angiograms, of which 48 (96%) were seen on the 3-D CT angiograms. Three-dimensional CT angiography was superior or equivalent to conventional angiography for depicting the shape, direction, and location of 33 (66%) of 50 aneurysms; however, it was often less useful than conventional angiography in delineating intracranial aneurysms adjacent to bone. Subtraction 3-D CT angiograms were obtained in 32 patients with a total of 46 aneurysms (in four cases, aneurysms were not depicted owing to excessive motion artifacts), and were superior or equivalent to conventional angiograms in all 46 cases. CONCLUSIONS: Subtraction 3-D CT angiography with the use of controlled-orbit helical scanning is effective in the detection of intracranial aneurysms.

Adult↗
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

Noninvasive identification of left ventricular involvements in arrhythmogenic right ventricular dysplasia: comparison of 123I-MIBG, 201TlCl, magnetic resonance imaging and ultrafast computed tomography.

We examined the feasibility of myocardial 123I-MIBG, 201TlCl, magnetic resonance imaging (MRI) and ultrafast computed tomography (UFCT) for the early detection of left ventricular involvements in 15 patients with arrhythmogenic right ventricular dysplasia (ARVD). Radionuclide ventriculography (RNV) and myocardial imaging with 123I-MIBG, 201TlCl, MRI and UFCT were performed in all 15 patients and in 10 normal subjects. The patients' scans were visually interpreted by two nuclear medicine physicians taking into consideration the extent score (ES) and severity score (SS) calculated by using the bull's-eye view in relation to normal data derived from the normal subjects. The left ventricular ejection fraction (LVEF) was measured by RNV. Fourteen (93%) patients showed regional 123I-MIBG defects, while 12 (80%) patients showed regional 201TlCl defects. The ES and SS were higher in 123I-MIBG than 201TlCl (ES: 31.5 +/- 18.5 vs. 17.5 +/- 18.2, p < 0.01, SS: 34.8 +/- 42.2 vs. 16.9 +/- 37.5, p < 0.01). Abnormal UFCT and MRI findings suggesting fatty involvements of the LV myocardium were demonstrated in 7 patients (Group B), while 7 patients showed regional 123I-MIBG defects without abnormal UFCT and MRI findings (Group A). 123I-MIBG was significantly more sensitive than UFCT and MRI (p < 0.05), although one patient, an exception, showed abnormal UFCT findings for the apex of the LV myocardium without abnormal 123I-MIBG and MRI findings. The LVEF, as a measure of LV systolic function, was better preserved in Group A than in Group B (59.3 +/- 3.6 vs. 45.8 +/- 5.8, p < 0.01). The present findings indicated that myocardial imaging with 123I-MIBG sensitively detects myocardial damage in patients with ARVD in the early stage when cardiac systolic function is still preserved.

3-Iodobenzylguanidine↗
PubMed1996

2-Deoxy-2-fluoro-D-glucose as a functional probe for NMR: the unique metabolism beyond its 6-phosphate.

Epimeric conversion of 2-deoxy-2-fluoro-D-glucose (FDG) to its 2-epimer 2-deoxy-2-fluoro-D-mannose (FDM) proved by 19F NMR has been shown to reflect the brain activity. To examine the feasibility of FDG as a new NMR probe for in vivo functional monitoring, we studied here the fundamental NMR properties of metabolites, spectral assignments, and reliability of NMR quantification. Metabolites confirmed in brain besides FDM-6-phosphate were as follows: FDG-1-phosphate, FDG-1,6-bisphosphate, FDM-1-phosphate, FDM-1,6-bisphosphate, and FDG and FDM derivatives of nucleotide diphosphate. NMR quantification of these metabolites was evaluated in comparison with the method of 18F-labeled FDG. In the NMR functional study using FDG, where a high dose is inevitable, the dose dependence of uptake was investigated. FDG uptake in mouse brain was shown to be in the range of interpretation using the biochemical parameters of enzymes for glucose uptake as long as a dose of < 200 mg/kg was used.

Animals↗
PubMed1996

[Significance of 123I-metaiodobenzylguanidine SPECT for detecting left ventricular involvement in patients with arrhythmogenic right ventricular dysplasia].

The right ventricle being primarily involved in ARVD, recent reports indicate the presence of histological and functional abnormalities in the left ventricle for some patients with ARVD. The aim of this study was to evaluate the significance of myocardial sympathetic dysfunction as an early sign of left ventricular (LV) involvement by 123I-MIBG (MIBG) SPECT and to compare the findings with those of 201TlCl (Tl) SPECT, radionuclide left ventriculography, ultrafast computed tomography (UFCT), magnetic resonance imaging (MRI) and echo-cardiography in 10 patients (pts) with ARVD. MIBG defects in LV regions were detected in 9 pts. Seven of the 9 pts showed MIBG defects in LV regions adjacent to RV. The subjects were divided into 2 groups based on left ventriculography, 5 with normal LVEF (> 55%) and 5 with reduced LVEF. In the normal LVEF group, 4 pts showed MIBG defects and 2 pts showed TI defects, and MIBG defects were larger than TI defects (ES: 14 +/- 6 vs. 5 +/- 7, p <0.05). In reduced LVEF group, all of 5 pts showed MIBG and TI defects, and MIBG defects were larger than TI defects (ES: 42 +/- 12 vs. 25 +/- 3, p <0.05). In comparison with normal LVEF group, reduced LVEF group showed larger and more severe MIBG defects (ES: 42 +/- 12 vs. 14 +/- 6, p <0.01, SS: 44 +/- 31 vs. 8 +/- 7, p <0.05). UFCT and MRI showed abnormal findings indicating LV fatty infiltration in only 3 of reduced LVEF group. Thus, MIBG showed abnormal distributions in the left ventricle with the highest frequency in all these modalities. These results suggest that MIBG SPECT provides a sensitive marker for detecting LV involvement in ARVD. Also, the extent of MIBG distribution abnormalities is helpful in assessing the severity of left ventricular involvement in patients with ARVD.

3-Iodobenzylguanidine↗
PubMed1996

[Recent progress of diagnostic imaging for aortic dissection].

After advent newly developed imaging modalities, diagnosis for aortic dissection had been extremely easier as compared with at the time when we had diagnosed this lesion solely by angiography. Characteristics of intra-arterial digital subtraction angiography (DSA), computed tomography (CT), magnetic resonance imaging (MRI) and transesophageal echocardiography (TEE) for this lesion was reviewed. In particular, we described how much three dimensional reconstructed CT using ultrafast computed tomography (electron beam tomography: EBT) and helical computed tomography (HCT) contribute to diagnosis for this disease. Furthermore, it was commented upon how to diagnose for acute aortic dissection with modern diagnostic tools based on our praxis.

Aortic Dissection↗
PubMed1993

[Percutaneous retrieval of intravascular foreign body from the pulmonary artery].

Percutaneous retrieval of intravascular iatrogenic foreign bodies is an important part of interventional radiology. Foreign body retrieval from the pulmonary artery is, however, not easy, and only a few cases reports have appeared in the literature. The authors have successfully removed dislodged CV catheter fragments from the pulmonary artery in 8 patients. Combined use of a long sheath and a balloon catheter is very helpful for this retrieval. The long sheath, originally designed for myocardial biopsy, is safely advanced to the pulmonary artery over the balloon catheter. Foreign bodies can be easily caught with a retrieval basket or snare, which is passed through the sheath. Another convenient device is a "balloon snare," which is a hand-made loop snare with an angiographic balloon catheter and a guide wire. For safe and easy retrieval of foreign bodies from the pulmonary artery, we recommend the combined use of a long sheath and a balloon catheter, or a "balloon snare."

Adolescent↗
PubMed1992

Immunochemical and biological characterization of outer membrane proteins of Porphyromonas endodontalis.

Outer membrane proteins (OMP) of Porphyromonas endodontalis HG 370 (ATCC 35406) were prepared from the cell envelope fraction of the organisms. The cell envelope that had been obtained by sonication of the whole cells was extracted in 2% lithium dodecyl sulfate and then successively chromatographed with Sephacryl S-200 HR and DEAE-Sepharose Fast Flow. Two OMP fractions, OMP-I and OMP-II, were obtained, and their immunochemical properties and induction of specific antibodies were examined. The OMP-I preparation consisted of a major protein with an apparent molecular mass of 31 kDa and other moderate to minor proteins of 40.3, 51.4, 67, and 71.6 kDa, while the OMP-II preparation contained 14-, 15.5-, 27-, and 44-kDa proteins as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis. OMP-I was found to form hydrophilic diffusion pores by incorporation into artificial liposomes composed of egg yolk phosphatidylcholine and dicetylphosphate, indicating that OMP-I exhibited significant porin activity. However, the liposomes containing heat-denatured OMP-I were scarcely active. Spontaneous and antigen-specific immunoglobulin M (IgM)-, IgG-, and IgA-secreting spot-forming cells (SFC) enzymatically dissociated into single-cell suspensions from chronically inflamed periapical tissues and were enumerated by enzyme-linked immunospot assay. In patients with radicular cysts or dental granulomas, the major isotype of spontaneous SFC was IgG. In radicular cysts, the OMP-II-specific IgG SFC represented 0.13% of the total IgG SFC, while the antigen-specific IgA or IgM SFC was not observed. It was also found that none of these mononuclear cells produced antibodies specific for OMP-I or lipopolysaccharide of P. endodontalis.

Antibodies, Bacterial↗
PubMed1991

[A case of agranulocytosis and jaundice due to cellulitis caused by insect bite].

A 58-year-old female was introduced to our hospital for admission on April 22, 1988, because of high grade fever and agranulocytosis. She had eschers on her left zygomatic region and medial region of the right thigh. The latter lesion was accompanied by cellulitis. Laboratory tests showed her WBC was 600/mm3 and T-Bil was 6.51 mg/dl. By using minocyclin, piperacillin and other drugs, her general condition and laboratory data became better in a few days. Although her skin lesions resembled "Tsutsugamushi disease", serological tests showed no evidence for Rickettia infection. So we could not rule out that another kind of insect bite may also develop such a severe clinical course. Furthermore, Staphylococcus aureus or Clostridium spp., which were detected in her pus, might have the toxic effects of inducing agranulocytosis, which might mainly be the result from the local WBC emigration, and jaundice, just like the effects of the endotoxin of Gram negative bacteria.

Agranulocytosis↗
PubMed1990

[Usefulness of ioversol (MP-328) in angiocardiography--a multicenter comparative study with iopamidol].

A randomized, controlled study was conducted to compare the radiographic efficacy, safety and usefulness of ioversol and iopamidol in 146 patients undergoing angiocardiography at six institutions. The hemodynamic and electrocardiographic effects were clinically insignificant and comparable for both agents. Ioversol demonstrated lower incidence of adverse reactions and less heat sensation in left coronary arteriography than those with iopamidol. Overall radiographic efficacy with ioversol was slightly better than with iopamidol, according to the evaluation by both investigators and committee members. Ioversol appears to be very useful for angiocardiography. This comparative study demonstrated the value of safety and efficacy evaluation criteria suggested by the preceding clinical trial with ioversol.

Adult↗
PubMed1990

[Preliminary study and clinical evaluation method of ioversol in angiocardiography--establishment of safety evaluation parameters and reliability of radiographic quality evaluation].

A multi-center clinical study of a new nonionic iodinated contrast medium (ioversol) was performed in 26 patients undergoing left ventriculography (LVG) and coronary angiography (CAG) at four centers. The aims of this study were to try to establish a clinical evaluation method on contrast media in angiocardiography and to determine radiographic efficacy and safety of ioversol. The reliability of the method evaluating the radiographic quality of the contrast medium was also examined with statistical analysis. Excellent radiographic efficacy was observed with ioversol and morphological diagnosis was possible in all cases. The electrocardiograms (ST-segment deflection, T-wave amplitude, QT interval, corrected QT interval, arrhythmia and heart rate) and the hemodynamic parameters (left ventricular systolic and end diastolic pressures, left ventricular dp/dt max, aortic systolic and diastolic pressures) indicated no clinically significant changes. This study suggested that the monitoring of the ECGs and hemodynamic parameters for up to three minutes after injection of the contrast medium is sufficient for the evaluation in LVG and CAG, and that the monitoring in CAG during the first injection into each left and right coronary artery is also sufficient for the purpose. Heat sensation during injection was mild. A patient had a symptom of nausea after ioversol administration, but it was mild and transient and resolved spontaneously. There were no abnormal clinical laboratory data related to ioversol. The reliability of the radiographic quality evaluated by the individual clinical investigators was considered to be high and adaptable. However, the evaluation in the blinded cinefilms by the committee members involving all investigators would be more preferable for the higher objectivity. The study results suggest that ioversol is considered to be the efficacious and safe contrast medium for the cardiovascular angiography.

Adolescent↗
PubMed1990

[MR imaging of aortic arch anomalies--an analysis of MR visualization of ductus arteriosus].

MR imaging of 10 patients with aortic arch anomaly was performed on a 1.0 T system. Coronal and sagittal images with a 5 to 6-mm-thick slice were taken in each patient and the visibility of the ductus arteriosus (ductus ligament) was detected on the sagittal images including its anatomical connection between the pulmonary trunk and arch vessel. The result indicates that MR imaging is of great help for detection of the ductus in case of aortic arch anomaly.

Adult↗
PubMed1990

[Improvement of heart failure after intracardiac operation for tetralogy of Fallot by transcatheter embolization of major aortopulmonary collateral arteries].

A two-year-and-ten-month-old female with tetralogy of Fallot with major aortopulmonary collateral arteries (MAPCAs) developed a persistent heart failure after an intracardiac repair. Angiograms revealed four MAPCAs originating from the upper portion of the descending thoracic aorta and draining into the left pulmonary artery, one MAPCA from the inferior phrenic artery into bilateral pulmonary arteries, and remaining one from the left subclavian artery into left pulmonary artery. Three of these MAPCAs were occluded by transcatheter embolization by the use of the steal coil. The heart failure was improved dramatically by this treatment.

Aorta↗
PubMed1989

[Angiocardiographic evaluation of left ventricular volumes and wall motion in infants and children: determination of normal values and analysis in diseased hearts].

Normal values of left ventricular (LV) function were determined angiographically in 50 normal infants and children. With these normal control data, LV function was assessed in 44 patients with a variety of cardiac diseases. LV volumes were calculated from 30 degrees right anterior oblique cineangiograms using area-length method. Normal values for LV end-diastolic volume (LVEDV) was expressed as a function of body surface area (BSA): LVEDV = 72.4 (BSA). The ratio of measured value to predicted normal value was calculated in the evaluation of diseased hearts. Mean LV ejection fraction (LVEF) in the normal group was 58.9 +/- 5.7%. There was no apparent correlation between LVEF and BSA or age of the patients. For the objective analysis of regional wall motion, the most adequate method was Area method which divides left ventriculogram into 5 regions. Mean ejection change in each region in the normal group was as follows; segment 1 (anterobasal) 52.4 +/- 6.9 (SD)%, segment 2 (anterolateral) 42.6 +/- 7.8%, segment 3 (apical) 46.3 +/- 6.7%, segment 4 (diaphragmatic) 37.0 +/- 7.0% and segment 5 (posterobasal) 29.0 +/- 5.6%. In the group of congenital heart disease with L-R shunt, 16 of 20 patients showed apparent increase of LVEDV. It remained within the normal range in 3 patients who had small shunt. There was no case which showed decreased LVEF or impaired regional wall motion. Both of the 2 patients with congestive cardiomyopathy showed increased LVEDV and decreased LVEF. Generalized hypokinesis of LV was recognized in one of them. In the group of Kawasaki disease with abnormal coronary arteries, which consisted of 27 ventriculograms in 22 patients, increased LVEDV and decreased LVEF were recognized in patients with coronary artery occlusion or large aneurysm. Decreased wall motion was observed in the territories of abnormal coronary arteries presenting occlusion or large-to-medium-sized aneurysm.

Angiocardiography↗