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Biomedical subjects

J Arisawa

Publications and source records attributed to J Arisawa.

At least 55 records · Page 3Linked to original sources
PubMed1989

Cross sectional echocardiographic anatomy of common atrioventricular valve in atrial isomerism.

The morphology of the common atrioventricular valve and its relation to the ventricles was assessed by cross sectional echocardiography in 17 patients with atrial isomerism--four with left isomerism and 13 with right isomerism. In 13 patients the atrioventricular valve consisted of four leaflets: a large anterosuperior leaflet, two lateral leaflets, and a posteroinferior leaflet. The remaining four patients had two anterosuperior leaflets. Five patients had hearts with a double inlet right ventricle and all of them had a rudimentary left ventricle. All the commissures were attached to the right ventricle. Five patients showed severe right ventricular dominance. The atrioventricular morphology in these five hearts differed from that in the patients with the usual atrial arrangement, concordant atrioventricular connection, and hypoplasia of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary left ventricle, and the posteroinferior leaflet was tethered to the ventricular septal crest. Six patients had a biventricular atrioventricular connection and two of them showed mild right ventricular dominance. The atrioventricular morphology in these hearts was the same as that seen in the patients with usual atrial arrangement and a concordant atrioventricular connection. The remaining patient showed dominance of the left ventricle. Only the anterosuperior leaflet bridged the rudimentary right ventricle in this heart.

Adolescent↗
PubMed1989

Primary thyroid lymphoma: comparison of CT and US assessment.

Sixteen patients with primary thyroid lymphoma were studied with computed tomography (CT) and ultrasonography (US), and findings were compared. In 13 of 16 patients, detection of the primary tumor with US and CT were comparable. US was superior in one case, and CT in another. One tumor was not detected with either technique. Thyroid lymphomas appeared as extremely hypoechoic masses intermingled with echogenic structures. Although echogenicity of unaffected thyroid tissue was also low because of coexisting Hashimoto thyroiditis, thyroid lymphomas were relatively well differentiated as markedly hypoechoic areas. Five tumors showed contiguous spread into both thyroid lobes. US and CT were equally sensitive in detection of superficial lymphomatous nodes (seven of 16 cases). CT was superior to US in the definition of tumor extent in two patients with intrathoracic tumor extension and in one with laryngeal invasion. In patients with suspected thyroid lymphoma, CT should be the primary radiologic technique used for diagnosis and staging; US will be useful in local follow-up.

Aged↗
PubMed1989

Assessment of ventricular contractile state and function in patients with univentricular heart.

To elucidate the ventricular contractile state and function in patients with univentricular heart, the ventricular volume, mass, ejection phase index, and wall stress were evaluated with biplane ventriculography and pressure measurement in 41 patients: 18 with left ventricular (LV) type (age, 6.4 +/- 6.1 years) and 23 with right ventricular (RV) type (age, 5.7 +/- 4.1 years), and data from patients with univentricular heart were compared with data from 19 normal control subjects (age, 7.2 +/- 4.3 years). Although the end-diastolic and end-systolic volumes were significantly greater in both types of univentricular heart than in the normal control group, the volumes for the LV and RV type patients did not differ from each other. The ejection fraction (EF) was depressed in both patient types of univentricular heart and was significantly (p less than 0.005) lower in the RV type than in the LV type patients (0.56 +/- 0.05 for LV type, 0.50 +/- 0.07 for RV type, and 0.64 +/- 0.03 for the control group). The ventricular mass was larger in both patient types of univentricular heart than in that of the control group, whereas the ratio of ventricular mass to end-diastolic volume was significantly (p less than 0.001) lower in the RV type patients than in the LV type patients and the control group (0.79 +/- 0.18 g/ml for LV type, 0.51 +/- 0.10 for RV type, and 0.82 +/- 0.13 for control group). End-systolic stress was significantly elevated in both types of univentricular heart (241 +/- 45 for LV type, 328 +/- 52 for RV type, and 205 +/- 26 kdynes/cm2 for the control group) and significantly (p less than 0.001) greater in the RV type than in the LV type patients. There was a significant inverse correlation (p less than 0.001) between end-systolic stress and the ratio of mass to end-diastolic volume in all the patients. In 27 patients (12 patients for LV type, 15 for RV type) the mean normalized systolic ejection rate corrected for heart rate (MNSERc) clearly fell below the 95% confidence limit of the normal end-systolic stress-MNSERc relation. The end-systolic stress:end-systolic volume ratio was also significantly depressed in both patient types of univentricular heart (3.49 +/- 1.77 for LV type, 4.07 +/- 2.13 for RV type, and 7.20 +/- 1.32 for the control group). In these variables, however, there were no significant differences between LV and RV type patients of univentricular heart.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiocardiography↗
PubMed1989

Quantitative evaluation of pulmonary regurgitation after repair of tetralogy of Fallot using real-time flow imaging system.

Real-time flow imaging of pulmonary regurgitation (PR) by two-dimensional pulsed Doppler echocardiography was performed in 34 patients after repair of tetralogy of Fallot. The right ventricle and pulmonary artery were demonstrated in the parasternal short axis view and PR flow was visualized. The image was frozen when the velocity of regurgitant flow was maximum at the level of the pulmonary valve. Pulmonary regurgitant area index (PRAI) was calculated from planimetric measurement of the area where PR flow was expressed. Grading of PR (1 to 3) was independently attempted according to the extension of PR flow detected in pulmonary artery by a range-gated pulsed Doppler echocardiography. PRAI (cm2/m2) was 0.36 +/- 0.29 (mean +/- standard deviation) in grade 1, 1.48 +/- 0.46 in grade 2, and 2.80 +/- 0.94 in grade 3. Severity of PR (grade 1 to 3) was also rated on the basis of the pulmonary arteriography and compared with PRAI. PRAI was 0.64 +/- 0.60 in grade 1, 1.07 +/- 0.63 in grade 2, and 2.21 +/- 1.67 in grade 3, respectively. RPAI showed strong correlation with pulmonary regurgitant fraction measured by videodensitometric study of right ventriculography (r = 0.84). Quantitative evaluation of PR using real-time flow imaging system is a reliable and useful method.

Adolescent↗
PubMed1989

Resistance oscillation of a Millipore DOPH model membrane accompanying structural changes.

A Millipore DOPH model membrane is composed of a Millipore filter whose pores are filled with dioleylphosphate (DOPH), and its electric resistance increases by a factor of 10(4) when Ca2+ ions are combined with it. The concentration of CaCl2 which increases the membrane resistance depends on the density of DOPH adsorbed in the filter and the initial KCl concentration. The surface structure of the membrane changes at the same time as the membrane resistance increases. The structural changes can be directly observed by a stereoscopic microscope: a considerable decrease of the hydrophilic regions of the membrane is caused by the Ca2+ ions. The membrane resistance which become higher with Ca2+ ions oscillates while a constant current and a static pressure stimuli are applied to the membrane. The frequency is dependent of these stimuli. These stimuli change the local membrane surface structure to make the hydrophilic areas. It is conceivable that the structural changes are caused by replacing Ca2+ ions with K+ ions in the hydrophilic bases of DOPH molecules.

Calcium↗
PubMed1989

Calcium ion concentration detected by structural changes of a Millipore DOPH artificial membrane.

The surface structure of an artificial membrane composed of a Millipore filter and a synthetic lipid analogue, dioleylphosphate (DOPH), immersed in KCl solution changes when the CaCl2 concentration reaches a critical value. Using a photomultiplier mounted on the eyepiece of a stereoscopic microscope the structural change can be measured quantitatively as an intensity variation of reflected light of the membrane surface. Calcium ions decreased the intensity to about 50% of the original hydrophilic state whose solution was only KCl. However, the degree of structure change was dependent on adsorbed DOPH density, solution temperature and pH value. On the other hand, using the light reflectance curves obtained from the structural observations, an unknown CaCl2 concentration in a KCl solution can be determined. Since the reflectance curve shifts widely with various densities of DOPH adsorbed in the Millipore filter, it is possible to measure the CaCl2 concentration over a wide range. The detection range was from 0.1 to 50 mM CaCl2.

Adsorption↗
PubMed1989

Gravity-dependent atelectasis. Radiologic, physiologic and pathologic correlation in rabbits on high-frequency oscillation ventilation.

The authors identify the radiologic features of progressive atelectasis induced under conditions of reduced lung volume. Control (n = 5) and experimental (n = 7) animals were placed on high-frequency oscillation (HFO) ventilation (mean airway pressure: 3 cm H2O) for 6 hours. In the experimental animals, lung volume was artificially reduced by pneumoperitoneum during HFO ventilation. Computed tomography scans and chest radiographs were obtained every hour, and arterial blood gases analyzed. No changes were detected in the control animals. In the experimental animals, in which hypoxemia developed, homogeneous opacity in the dependent lung was found on CT images, and chest radiographs showed a diffuse homogenous shadow with loss of lung volume. Study of pathologic sections from the lung showed that the roentgenographic findings represented atelectasis. The lung was divided into three zones, from dependent to nondependent regions: severe atelectasis, mild atelectasis, and normal lung. Hyperinflations eliminated atelectasis seen on the CT images and alleviated hypoxemia; however an undesirable effect that causes barotrauma also was observed.

Animals↗
PubMed1989

[Cavitating malignant neoplasms in the lung].

Cavitation was found in 8.3% of 96 primary lung cancers, and in 4.5% of 111 metastatic neoplasms. Of 13 excavating lung tumors, seven had adenocarcinoma, 3 squamous cell carcinoma, one anaplastic carcinoma, one hemangioendothelioma, and one malignant melanoma. Primary cavitary lung cancers had relatively thick walls, irregular internal and outer contours, and the location of the cavity was more often central. Excavating pulmonary metastases had smooth outer margin, more often irregular internal contour, and the location of the cavity was central. Among them, four cases had thin-walled cavity. Thin-section CT was useful in the evaluation of the margin of the tumors and the internal contour of the cavities, and in the detection of small cavities in the tumors.

Adenocarcinoma↗
PubMed1989

Depressed myocardial contractility and normal ejection performance after aortic valve replacement in patients with aortic regurgitation.

Left ventricular cineangiography and pressure measurement were performed in 33 patients with chronic aortic regurgitation before and after aortic valve replacement and in 25 normal control subjects. Stress and volume were analyzed. The 33 patients were divided into three groups based on preoperative end-systolic volume index: 15 with an index of less than 100 ml/m2 (group I), 12 with an index of 100 to 200 ml/m2 (group II), and six with an index of more than 200 ml/m2 (group III). Afterload estimated as end-systolic stress, which was significantly elevated in all groups before operation, returned to normal postoperatively. Systolic pump function improved postoperatively in all groups; group I and group II showing the most improvement with group III still having an abnormal ejection fraction. The ratio of end-systolic stress to end-systolic volume index, which is an index of contractile state that is relatively independent of preload and afterload, was abnormal in each group preoperatively. Postoperatively, the ratio improved in each group (from 2.8 +/- 0.5 to 4.8 +/- 0.9 for group I, from 1.4 +/- 0.3 to 3.2 +/- 0.6 for group II, and from 0.8 +/- 0.2 to 2.6 +/- 0.8 for group III, compared with 5.9 +/- 1.0 for control subjects). Group I had normal values whereas group II and group III had subnormal ratios, suggesting a depressed contractility. All 15 patients in group I had values that fell within the 95% confidence limits of the linear inverse relationship between ejection fraction and end-systolic stress for control subjects. Nine of the 12 patients in group II and all six in group III had values that fell below the 95% confidence limits of the normal ejection fraction-end-systolic stress relationship. Aortic valve replacement may reduce afterload and improve systolic pump function in many patients with aortic regurgitation. However, there is a subgroup of patients who, despite normal or near-normal pump performance as assessed by ejection fraction, have depressed myocardial contractility characterized by an abnormal relationship between end-systolic stress and either ejection fraction or end-systolic volume.

Adolescent↗
PubMed1988

Primary thyroid lymphoma: evaluation with CT.

The appearance of primary thyroid lymphoma on computed tomographic (CT) scans and clinical data for 15 patients were analyzed. The CT appearances were classified into three types: 12 patients (80%) had a solitary nodule (type 1), two (13%) had multiple nodules (type 2), and one (7%) had a diffuse goiter (type 3). In 47% of cases, both lobes were involved. The tumors had a strong tendency to compress (80%) or infiltrate (53%) the surrounding structures. The frequency of calcification (7%) or necrosis (7%) was low. Most patients (87%) had a rapidly enlarging thyroid mass, and six (40%) complained of symptoms from obstruction. All patients had coexistent Hashimoto thyroiditis. In 13 of 15 patients (87%), a highly probable diagnosis of thyroid lymphomas was determined with CT and clinical findings. A staging workup with CT and clinical findings confirmed at biopsy will allow appropriate therapy and may lead to improved prognosis for patients with this condition.

Aged↗
PubMed1988

Quantitative cineangiographic analysis of ventricular volume and mass in patients with single ventricle: relation to ventricular morphologies.

With the use of biplane selective ventriculography, the ventricular volume, ejection fraction, and ventricular mass were evaluated in 28 patients with a single ventricle, and those with the left ventricular type (LV type, 12 patients) and right ventricular type (RV type, 16 patients) were compared. There were no significant differences in terms of age, hemoglobin, systemic oxygen saturation, or pulmonary-to-systemic flow ratio in the two groups. No patients with atrioventricular valve regurgitation were included. The ventricular cavity volume was calculated by the area-length method. The ventricular mass volume was determined as the shell volume created by subtracting the ventricular cavity volume from the total ventricular volume calculated by adding the free wall thickness to the chamber dimensions. The ventricular mass volume was converted to mass by multiplying by the gravity of the heart muscle. There was no significant difference between patients with the LV type and RV type of single ventricle with respect to the end-diastolic ventricular volume (188 +/- 53 and 179 +/- 61 ml/m2 in LV and RV types, respectively), end-systolic volume (88 +/- 31 and 84 +/- 27 ml/m2), or ejection fraction (0.54 +/- 0.06 and 0.52 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1988

CT appearance of acute radiation-induced injury in the lung.

To determine how soon radiation-induced lung injury is detectable, to compare the CT findings with those on chest radiographs, and to observe the appearance of the abnormality during the acute phase, we performed 83 CT studies in 17 radiotherapy patients at relatively short intervals. All 17 patients received fractionated radiotherapy to the thorax with a large irradiated lung volume. The CT findings were variable; pulmonary infiltrates were homogeneous, patchy, or discrete. CT abnormalities were evident in 15 of 17 cases within 16 weeks after radiotherapy; in 13 of these it was detected within 4 weeks. In three of these 15 cases, no abnormality was detected on chest radiographs, and in three other cases, the change was observed much later on chest radiographs than on CT scans. In the other nine cases, abnormalities were detected simultaneously on CT scans and chest radiographs. In four cases, extensive radiation pneumonitis was observed on CT, but in two of these, the change was misdiagnosed on the chest radiograph. We conclude that CT is useful in the detection of acute radiation-induced pulmonary disease.

Acute Disease↗
PubMed1987

Mediastinal distortions from focal masses: a CT and radiographic study.

Fifty-seven mediastinal masses were studied by computed tomography (CT) and chest radiographs to determine how their specific site of origin affected their direction of expansion and the distortion of contiguous structures. Forty-four masses arose anterior to the heart and great vessels (precardiovascular compartment). When these masses arose on the right, they extended posteriorly only as far as the coronal plane of the trachea. Left-sided masses were not similarly limited in their posterior extension. Thirteen masses arose around the trachea and esophagus or in the subcarinal space (tracheoesophageal compartment). Masses in the upper part of this compartment caused tracheal and great-vessel displacement. The mobile superior vena cava (SVC) was more often distorted than was the aortic arch. Subcarinal masses always expanded to the right, displacing the right lower lobe. The heart and great arteries were more resistant to displacement and distortion than were the systemic veins. The trachea and mediastinal bronchi were intermediate in their displacement. The hila were effective barriers to the expansion of mediastinal masses.

Adolescent↗