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Biomedical subjects

J Sanada

Publications and source records attributed to J Sanada.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Late diastolic mitral regurgitation: pulsed Doppler echocardiographic study].

Since the description of late diastolic mitral regurgitation (MR) detected by left ventriculography, the risk of overestimating systolic MR has been pointed out. However, it has not been well studied by pulsed Doppler echocardiography, though this method is thought to be extremely useful to analyze systolic MR. The purpose of this study was to evaluate the usefulness of pulsed Doppler echocardiography in assessing late diastolic MR and to clarify the pathophysiology of this MR. With the probe in the apical position, the blood flow pattern at the left atrial outflow tract was investigated in 226 consecutive cases who underwent left ventriculography. Late diastolic MR, which could not be attributed to ventricular premature contraction, was observed in 10 cases (4.4%) by left ventriculography. Meanwhile, by pulsed Doppler echocardiography, late diastolic disturbed flow directing towards the left atrial cavity in late diastole was detected in 15 cases (6.6%) including 10 cases with positive left ventriculographic MR. Among these 15 cases, 14 (93%) had atrial fibrillation and exhibited this MR only in the cardiac cycle with prolonged R-R intervals. The limitation in number of cardiac cycles which could be analyzed and the rapid heart rate eliminating the appearance of the beat with prolonged R-R intervals may be the reasons for the paucity of late diastolic MR by left ventriculography. Ten cases (66%) of late diastolic MR, including one with sinus rhythm, had aortic regurgitation, three cases showed high-grade systolic MR, and two had atrial septal defect. The simultaneous recording of pulmonary arterial wedge pressure and left ventricular pressure in three patients show a reversal of pressure gradient across the mitral valve in late diastole when the R-R interval was prolonged. In conclusion, pulsed Doppler echocardiography is useful in detecting late diastolic MR, and in reducing overestimates of systolic MR by ventriculography which was induced by erroneous addition of late diastolic MR, because Doppler method has better time resolution in phase analysis. We believe that incomplete premature mitral valve closure caused by a delay in left ventricular contraction following prolonged R-R intervals, and the reversal of left atrial-left ventricular pressure gradient induced by left ventricular over-filling played important roles in the occurrence of late diastolic MR.

Adult↗
PubMed1985

[Left ventricular relaxation property evaluated by isovolumic relaxation flow].

The blood flow recorded in the center of the left ventricle (LV) during the isovolumic relaxation period, i.e., isovolumic relaxation flow (IRF), was evaluated by pulsed Doppler echocardiography. The subjects consisted of 17 normal persons, 12 patients with angina pectoris (AP), 63 with old myocardial infarction (OMI), 16 with hypertrophic cardiomyopathy (HCM) and 16 with dilated cardiomyopathy (DCM). In the normal subjects, the IRF showed a laminar flow and it was directed from the center of the LV toward the apex. The maximum velocity of the IRF coincided with the second heart sound. In the patients with heart diseases, the IRF was classified into three patterns. Type A, in which the IRF was directed toward the apex of the LV: This pattern was observed in two different patient groups from the standpoint of LV wall motion and LV ejection fraction (LVEF). One group had either a normal LVEF without wall motion abnormalities or normal LVEF with a small area of abnormal wall motion in the anterior and/or apical portions. The other group had various LVEF with abnormalities of wall motion in the posterior and/or inferior portions. The duration of the IRF in type A was prolonged in AP (142 +/- 35 msec), OMI (152 +/- 14 msec), HCM (166 +/- 33 msec) and DCM (171 msec) when compared with those of the normal subjects (119 +/- 35 msec). The acceleration time (time interval from the beginning of the IRF to the point of the maximum flow velocity) in the normal subjects was 25 +/- 8 msec, but they were prolonged in AP (37 +/- 12 msec), OMI (59 +/- 22 msec), HCM (64 +/- 18 msec) and DCM (58 msec). The acceleration rate (increment of the flow velocities per sec) was significantly decreased in AP (8.9 +/- 3.2 m/sec2), OMI (4.5 +/- 2.7 m/sec2), HCM (4.5 +/- 1.1 m/sec2) and DCM (3.7 m/sec2) when compared with those of the normal subjects (12.6 +/- 4.0 m/sec2). Type B, in which the IRF was directed away from the LV center to the base of the LV: The patients with this type had slightly depressed LVEF with moderately extended abnormalities of wall motion in the anterior and/or apical portions. Type C without discernible IRF: The patients with this type had severely depressed LVEF with generalized abnormalities of wall motion. It was concluded that the patterns of the IRF are affected by regional wall motion and the IRF seems to be caused by LV relaxation.

Angina Pectoris↗
PubMed1984

[Quantitation of mitral regurgitation by left ventricular blood flow dynamics: a pulsed Doppler echocardiographic study].

Using pulsed Doppler echocardiography, the blood flow dynamics in the left ventricular cavity were studied in 52 cases with mitral regurgitation (MR) (32 cases of grade 1 or 2 and 20 cases of grade 3 or 4 according to the Sellers' classification) were studied to quantify the severity of MR. Twelve healthy subjects served as the control. The results were as follows: At the mitral orifice, systolic laminar flow toward the left atrial cavity was observed in 17 cases with grade 3 or 4 MR. This flow was shown to begin at the isovolumic contraction phase and it had a higher velocity in end-systole. Thus, it could easily be differentiated from ejection flow observed in the left ventricular outflow tract. The duration of systolic blood flow in the mid-ventricle was significantly prolonged over that in the outflow tract in cases with grade 3 or 4 MR compared to those with grade 1 or 2 MR (grade 1 or 2: 4 +/- 27 msec, grade 3 or 4: 65 +/- 35 msec, p less than 0.001), indicating that MR continued even after the end of left ventricular ejection. The velocity of early diastolic left ventricular inflow was estimated for cases having isolated MR (16 cases with mitral chordal rupture and one case of mitral valve prolapse syndrome). In the healthy subjects and cases with grade 1 or 2 MR, the velocity was less than 84 cm/sec. The velocity was increased more than 100 cm/sec in grade 3 or 4 MR. These observations indicated the clinical potential of abnormal blood flow dynamics in the left ventricular cavity in the semi-quantification of MR.

Blood Flow Velocity↗
PubMed1982

A thrombotic tendency in patients with infective endocarditis.

An attempt was made to evaluate a thrombotic tendency in cases of infective endocarditis (IE) from the viewpoint of the changes of platelets and coagulo-fibrinolysis. Qualitative changes of platelets by thrombi formation were detected by showing activated responses of platelets to adenosine diphosphate or collagen and by showing a high level of plasma beta-thromboglobulin which is released by platelets during aggregation. A mild hypercoagulable state without acceleration of fibrinolysis was also detected by showing low levels of plasma antithrombin III which is the most potent antithrombin in the blood and normal levels of plasma alpha 2-plasmin inhibitor in the blood. From above findings, it was concluded that a thrombotic tendency in cases of IE was clearly detected by qualitative changes of platelets by thrombi formation and by mild hypercoagulability without acceleration of fibrinolysis.

Adenosine Diphosphate↗
PubMed1980

Hypercoagulability in patients with mitral stenosis -- from the viewpoint of the behavior of plasma antithrombin III and alpha2-plasmin inhibitor.

The concentration of plasma antithrombin III (AT III) and the biological activity of plasma alpha2-plasmin inhibitor (alpha 2-PI) were measured in cases of mitral stenosis (MS) and rheumatic heart disease (RHD) without MS. Cases of MS showed the findings of the low levels of plasma AT III and normal or a little higher levels of plasma alpha 2-PI, that was not recognized in RHD without MS. This finding was interpreted to be hypercoagulable because of the acceleration of coagulation and of little or slight retardation of fibrinolysis. Besides, the influence of atrial fibrillation and chronic congestive heart failure on hypercoagulability in cases of MS was detected clearly, but the influence of them in cases of non-RHD was obscure. As the results, the severer the degree of MS, the clearer the hypercoagulable state. Therefore, the prethrombotic state existed in cases of MS, combined with blood flow disturbance due to atrial fibrillation or chronic congestive heart failure, endocardial damage resulted from rheumatic fever in an early stage and hypercoagulable state mentioned above in the present study. There was no significant difference between cases with and without thrombi in the degree of hypercoagulability in subjects with MS shown in the present work. It was concluded that the consumption of AT III caused the low levels of it in cases of MS, and that the low production of AT III in the liver rather than consumption caused the low levels of it in cases of non-RHD.

Adult↗
PubMedDate not supplied

Cystic duct remnant carcinoma with widespread invasion along the extrahepatic bile duct wall: dynamic CT findings.

We report a case of remnant cystic duct carcinoma with widespread invasion along the common bile duct wall. Thin-slice dynamic computed tomography showed circumferential wall thickening of the extrahepatic bile duct (from the common hepatic duct to the intrapancreatic common bile duct) and the remnant cystic duct. Pathologically, the extrahepatic bile duct wall was thickened due to submucosal tumor infiltration by cystic duct papillary adenocarcinoma.

Aged↗
PubMedDate not supplied

Tumor-associated focal chronic pancreatitis from invasion of the pancreatic duct by common bile duct carcinoma: radiologic-pathologic correlation.

We report a case of tumor-associated focal chronic pancreatitis of the uncinate process of the pancreas. The chronic pancreatitis was secondary to stenosis of the main pancreatic duct from invasion by a common bile duct carcinoma. A feature distinguishing the chronic pancreatitis from pancreatic carcinoma was the localized dilatation of pancreatic duct branches evident in the focal lesion of the uncinate process.

Cholangiocarcinoma↗
PubMedDate not supplied

MRI findings of primary biliary cirrhosis: correlation with Scheuer histologic staging.

Magnetic resonance imaging (MRI) findings of primary biliary cirrhosis (PBC; currently regarded as a vanishing bile duct syndrome) are not established. In this report, we describe our preliminary analysis of the relation between MRI findings and histopathologic staging of PBC and review clinical, morphologic, and MRI findings of PBC especially focusing on the staging of PBC.

Diagnosis, Differential↗
PubMedDate not supplied

Intrahepatic biliary calculi: correlation of unusual MR findings with pathologic findings.

We report a case of intrahepatic biliary calculi. A localized dilated intrahepatic duct of the left lateral segment of the liver was filled with material that showed marked hyperintensity on T1- and T2-weighted magnetic resonance (MR) images. These MR findings are unusual for intrahepatic stones. Pathologically, the stones were muddy bilirubin calculi, the chemical and physical characteristics of which are surmised to have been the cause of the unusual MR findings.

Bile Ducts, Intrahepatic↗
PubMedDate not supplied

MR imaging of focal splenic extramedullary hematopoiesis in polycythemia vera: case report.

We report a case with focal mass-like lesion of the spleen in polycythemia vera. Magnetic resonance imaging of the lesion showed homogeneous hyperintensity on T2-weighted images, with progressive enhancement on dynamic magnetic resonance images after bolus injection of gadolinium. The magnetic resonance features of focal splenic extramedullary hematopoiesis have not been previously reported.

Aged↗
PubMedDate not supplied

Peritumoral spared area in fatty liver: correlation between opposed-phase gradient-echo MR imaging and CT arteriography.

BACKGROUND: The purpose of the present study was to evaluate the magnetic resonance findings of a spared area of fatty liver caused by hepatic tumors and clarify the etiology of this phenomenon by computed tomographic (CT) arteriography. METHODS: Six patients with hepatic tumors (metastases from colon cancer, n = 3; breast cancer, n = 2; hepatocellular carcinoma, n = 1) were examined. In-phase (IP) and opposed-phase (OP) T1-weighted spoiled gradient-echo images were obtained. CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) were also performed. Pathologic confirmation was obtained in three patients with metastases from colon cancer. RESULTS: In all six patients, peritumoral ringlike or wedge-shaped hyperintense areas in relation to the tumor and the surrounding steatotic liver parenchyma were clearly visualized on OP images alone. This area appeared as a perfusion defect on CTAP and ringlike or wedge-shaped enhancement on CTHA. Pathologically, the peritumoral hyperintense areas on OP images were compatible with the spared area of fatty liver. CONCLUSION: A peritumoral spared area can be demonstrated with OP images. The etiology of the phenomenon is correlated with decreased portal flow and increased arterial flow in the peritumoral hepatic parenchyma.

Adult↗
PubMedDate not supplied

Heparin binding protein-44 (HBP-44)/receptor-associated protein (RAP)mediates cell-substratum adhesion of mouse NIH/3T3 cells through its binding to low density lipoprotein (LDL) receptor-related protein (LRP).

The low density lipoprotein receptor-related protein (LRP) is a multifunctional endocytic receptor with the ability to bind and endocytose several structurally and functionally distinct ligands. The 39 kDa receptor-associated protein (RAP) is an endoplasmic reticulum (ER) resident protein, which is believed to function intracellularly as a molecular chaperone for LRP and to regulate its ligand binding activity along the secretory pathway. Mouse heparin binding protein-44 (HBP-44) is a homologue of human RAP. Using a recombinant form of HBP-44 expressed in Escherichia coli cells as a highly specific ligand for LRP, we demonstrated that HBP-44 coated on cell culture plates mediates the cell-substratum adhesion of mouse 3T3 fibroblasts in a dose-dependent manner, with 50% attachment at the concentration of 0.2 micrograms/ml. Ligand blot analysis with HBP-44 of whole cell extracts and the materials precipitated by anti-LRP antibodies revealed that the receptor for HBP-44 on NIH/3T3 cells was LRP. The results suggest that LRP serves as a cell adhesion receptor in some cells.

3T3 Cells↗