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Biomedical subjects

K Kuwako

Publications and source records attributed to K Kuwako.

At least 19 recordsLinked to original sources
PubMed2002

Cell death induced by a caspase-cleaved transmembrane fragment of the Alzheimer amyloid precursor protein.

The Alzheimer amyloid precursor protein (APP) is a transmembrane protein whose abnormal processing is associated with the pathogenesis of Alzheimer's disease. Activated caspases cleave APP and generate its carboxyl-terminally truncated fragment (APPdeltaC31). We have previously reported that overexpression of wild-type APP induces caspase-3 activation and apoptosis in postmitotic neurons. We now report that APPdeltaC31 potentially plays pathophysiological roles in neuronal death. Adenovirus-mediated overexpression of wild-type APP695 induced activation of caspase-3 and accumulation of APPdeltaC31 in postmitotic neurons derived from human NT2 embryonal carcinoma cells, whereas an APP mutant lacking the Abeta(1-20) region induced neither caspase-3 activation nor APPdeltaC31 generation. Inhibition of caspase-3 suppressed the generation of APPdeltaC31 in APP-overexpressing neurons. Forced expression of APPdeltaC31 induced apoptotic changes of neurons and non-neuronal cells, but failed to activate caspase-3. The cytotoxicity of APPdeltaC31 was also dependent on the Abeta(1-20) region. These results suggest that accumulation of wild-type APP activates neuronal caspase-3 to generate APPdeltaC31 that mediates caspase-3-independent cell death.

Adenoviridae↗
PubMed1992

Anomalous origin of the left coronary artery from the pulmonary artery: direct assessment of anomalous and collateral coronary flow by pulsed Doppler echocardiography.

We directly assessed the anomalous and collateral coronary flow profiles of a 58 year-old-man with Bland-White-Garland syndrome using pulsed Doppler echocardiography. Doppler recordings in this patient document the utility of pulsed Doppler echocardiography in the assessment of a cardiac shunt associated with a congenital coronary anomaly in an adult.

Blood Flow Velocity↗
PubMed1992

Fabry's disease with complete atrioventricular block: histological evidence of involvement of the conduction system.

A 63 year old man with complete atrioventricular block was diagnosed as having Fabry's disease. A short PR interval is a common electrocardiographic finding in Fabry's disease, but complete atrioventricular block is a very rare complication. Necropsy indicated that lipid accumulation in the atrioventricular conduction system was the probable cause of this patient's atrioventricular block.

Electrocardiography↗
PubMed1991

[Long-term prognosis in patients with echocardiographic left ventricular dysfunction masquerading as dilated cardiomyopathy].

The long-term prognosis and prognostic factors were assessed in patients with left ventricular dilatation with impaired function secondary to idiopathic dilated cardiomyopathy (DCM) or to heart diseases of various pathogeneses masquerading as DCM (DCM-like). The echocardiographic criteria for DCM-like disease were 1) left ventricular end-diastolic dimension exceeding 60 mm and 2) fractional shortening less than 15%. Those who showed improvement in either of these 2 parameters within 3 months were excluded from this study. One hundred and fifty-eight of 35,250 serially examined patients fulfilled the definitions. The pathogeneses of diseases were valvular heart disease (VHD) in 30 patients, ischemic heart disease (IHD) in 37, alcoholic cardiomyopathy (AC) in 12, hypertensive heart disease (HHD) in 31 and DCM in 48. All of the survivors were followed for more than 24 months; an average of 40 months. During this period, there were a total of 75 deaths, 18 (27%) of whom were judged as sudden death. Five-year survival rates calculated using the Kaplan-Meier method in AC and HHD were 86% and 77%, respectively, which were significantly higher than those in DCM (48%; p < 0.05); whereas, patients with VHD and IHD had lower values (60% and 46%, respectively) which were nearly equal to those in DCM. Factors that contributed to the increase in total cardiac mortality were advanced age, higher NYHA functional class, larger cardiac size on chest radiograph and history of heavy alcohol intake. Each of these factors were closely related to the specific pathogeneses as follows: age to IHD, cardiac size to VHD, and NYHA functional class to DCM. Long-term prognosis of DCM-like heart diseases, especially those of IHD and VHD, seemed to be as bad as those of DCM.

Adult↗
PubMed1990

Angioplasty of stenoses adjacent to aneurysmal coronary artery disease.

We examined the effectiveness and safety of performing angioplasty on stenoses adjacent to aneurysmal coronary artery disease. Out of 386 consecutive lesions (270 patients) on which we performed angioplasty, 13 lesions (13 patients) were within one balloon length of aneurysmal disease (group A) and 373 lesions (257 patients) were not (group NA). Angioplasty had previously been performed on 10 lesions (77%) in group A but only on 112 lesions (30%) in group NA (p less than 0.01). In group A the angioplasty success rate was 100% (13/13). The maximum inflation pressure was 6.5 +/- 1.1 atm, the frequency of inflation was 6.1 +/- 2.8, the average inflation duration was 60 +/- 0 sec, and the balloon/artery ratio was 1.20 +/- 0.11. There were no major complications. Restenosis occurred in only one lesion. There were no significant differences in the angioplasty results, procedures, complications and the incidence of restenosis between both groups. The ratio of the diameter of the aneurysmal disease to the mean diameter of the normal adjacent segments remained unchanged throughout the follow-up period. These data suggest that angioplasty may be an effective and safe treatment for those stenoses that are adjacent to aneurysmal coronary artery disease.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Medical treatment of type III dissecting aortic aneurysms: influence of the shape of the false lumen assessed by X-ray CT as a factor in the long-term prognosis].

The future needs of surgical repair for type III dissecting aneurysms among medically-treated patients were estimated according to the influence of the shapes of false lumina assessed by contrast-enhanced CT scans and by the level of blood pressure control at the time of discharge on the long-term prognoses. Thirty-six patients, 30 males and six females, whose mean age was 61 years, underwent enhanced CT scans at their discharge. Events, including deaths and dissection-related surgery were analyzed by a nonparametric actuarial method of Kaplan and Meier. The changes in CT findings were also studied in 33 patients who underwent follow-up CT scans within a mean interval of 3.5 years. 1. Systolic blood pressure was maintained below 140 mmHg (good control group) in 15 patients, and above 140 mmHg (poor control group) in 18 controls. There were no significant differences between the two groups for event-free survival rates. 2. The shapes of false lumina assessed by enhanced CT scans at the time of discharge were categorized in three types; 21 patients (group A) without false lumina of the aorta, or with a small crescentic false lumen in the thoracic aorta (type a), six patients (group B) with intimal flaps and two contrast-material-filled lumina in the thoracic aorta (type b), and nine patients (group C) with expanded false lumina or a false lumen whose margin was convex towards a true lumen in the thoracic aorta (type c).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[A case of intrapleural rupture of pulmonary arteriovenous malformation with shock].

We report a case of a 59-year-old male who suddenly developed massive right hemothorax and shock due to pulmonary arteriovenous malformation (AVM). He was admitted as an emergency case because of severe back pain, cyanosis and cold sweat. Although shock with massive right hemothorax was found, echocardiographic and X-ray computed tomographic examination showed no dilatation of the aorta, no intimal flap in the aorta and no pericardial effusion which suggested aneurysm. Pulmonary arteriography, performed subsequently, disclosed intrapleural rupture of the right pulmonary AVM. The patient recovered successfully from the state of shock. The pulmonary AVM was removed by segmentectomy of the right lung (S4). He was discharged following an uneventful postoperative course. Intrapleural rupture with shock is a very rare complication of pulmonary AVM. Pulmonary AVM should be considered as one possible cause in patients with massive hemothorax and shock.

Arteriovenous Malformations↗
PubMed1990

[A case of right-sided infective endocarditis in a drug addict].

A 49-year-old man was admitted to Mitsui Memorial Hospital because of fever of unknown origin. Since one year ago, he had often used intravenous narcotic drugs. Ten months before his admission, he had his first experience of fever and a chill. Four months later, he was admitted to a hospital under the diagnosis of pneumonia and he was treated successfully. After his discharge, he began to use drugs again, which resulted in the repetition of fever and chills during four months prior to his admission to our hospital. On admission, physical findings concerning the patient were unremarkable, except for mild hepatomegaly. ECG and chest X-ray were normal. Laboratory data revealed marked inflammatory changes and severe liver injury. Blood culture disclosed Campylobacter fetus and two dimensional echocardiography showed a large vegetation on the anterior tricuspid valve. He was diagnosed as isolated tricuspid infective endocarditis accompanied with acute hepatitis due to drug abuse. Moreover pulmonary perfusion scintigraphy showed decreased perfusion in the right lower lung field, which suggested that pneumonia of six months ago was due to septic pulmonary emboli from the infected tricuspid valve. The combined antibiotics therapy was successful. By the follow-up echocardiographic studies, the size of vegetation was observed to decrease progressively.

Campylobacter Infections↗
PubMed1989

[The relationship between mitral regurgitation and asynergy of the left ventricle in old myocardial infarction].

To elucidate the mechanism of mitral regurgitation (MR) in patients with old myocardial infarction, two-dimensional (2D) and 2D Doppler echocardiographic examinations were performed in 92 patients. According to the sites of asynergy in the short-axis view of the left ventricle at the papillary muscle level, the patients were classified in three groups; i.e., anteroseptal (AS) group (49 cases), inferoposterior (IP) group (29 cases), and the AS + IP group (14 cases). The existence and severity of MR were evaluated by 2D Doppler echocardiography and the presence of mitral valve prolapse (MPV), by 2D echocardiography. The mitral valve ring diameter was also measured. The incidence of MR was significantly higher in the IP group (41%) and AS + IP group (43%) than in the AS group (20%) (p less than 0.05, respectively). In the IP group, 21 patients had left ventricular asynergy at the base of the posterior papillary muscle; eight did not. In the former 21 patients with asynergy, MR was detected in 12 (57%) and MVP in nine (43%), whereas neither MR nor MVP was detected in the eight patients without asynergy. The grade of MR assessed by 2-D Doppler echocardiography was significantly more severe in patients with MVP than in those without MVP (MR distance: 23 +/- 6 mm with MVP vs 11 +/- 1 mm without MVP; p less than 0.05, MR area; 312 +/- 217 mm2 with MVP vs 64 +/- 29 mm2 without MVP; p less than 0.05). MR appeared at the mitral orifice between its middle portion and the posteromedial commissure, which coincided with the site of MVP in the majority of cases. In the AS and AS + IP groups, however, such close relationships between MR and MVP were absent. In these groups, mitral valve ring diameters were significantly larger in patients with MR than in those without MR (AS group: 32 +/- 3 mm with MR vs 24 +/- 2 mm without MR; p less than 0.01, IP group: 26 +/- 2 mm with MR vs 25 +/- 2 mm without MR; NS, AS + IP group: 30 +/- 3 mm with MR vs 24 +/- 1 mm without MR; p less than 0.05). Mitral valve ring diameters in the IP group with MR (26 +/- 2 mm) were smaller than in those in the AS and AS + IP groups with MR, and did not differ from those in the IP group without MR (25 +/- 2 mm). In conclusion, posterior papillary muscle dysfunction was mainly responsible for MR in the inferoposterior infarction and the dilatation of the mitral valve ring in the infarction involving the anteroseptal wall.

Aged↗
PubMed1989

[Clinical significance of aortic ring dilatation and changes in aortic root configuration in the pathogenesis of non-rheumatic aortic regurgitation].

This study was undertaken to determine the etiology of non-rheumatic aortic regurgitation (AR) by two-dimensional echocardiography. Dimensions of the aortic root at the levels of the surgical aortic ring (ARDs), sinus of Valsalva (AOD), and anatomical aortic ring (ARD) were measured in 23 patients who underwent aortic valve replacement due to AR with idiopathic aortic root dilatation, in 15 hypertensive patients without AR and in 15 normal controls. The 23 patients with AR were classified as annuloaortic ectasia (AAE) (seven cases) and non-AAE (16 cases) groups. In the AAE group, the ascending aorta and aortic root were markedly dilated and had a pear-like configuration on aortography while the aorta had a normal configuration in the non-AAE group. ARDs was significantly larger in the non-AAE and AAE groups than in the hypertension and normal control groups. AOD and ARD were significantly larger in the hypertension and non-AAE groups than in the normal controls, and those in the AAE group were greater than those in any other group. The end-diastolic shape of the aortic valve in the long-axis view was "Y" shaped in the normal control and hypertension groups, "T" shaped in the non-AAE group, and the patients with AAE showed no cuspal coaptation. AR due to aortic ring dilatation, mainly reported by pathologists, were due to marked degree of ARD dilatation. However, our two-dimensional echocardiographic study showed that moderate dilatation of the entire aortic root in the non-AAE group seemed to be an important factor in the genesis of AR, even without dilatation of ARD.

Adult↗
PubMed1988

[Tricuspid regurgitation in mitral valve prolapse studied by two-dimensional color flow mapping].

To assess the incidence of tricuspid regurgitation (TR) in mitral valve prolapse (MVP), 96 patients with MVP and 23 normal control subjects were studied. Subjects in the MVP group were further classified as a group with mitral regurgitation (MR(+) group: 61 cases), and MR(-) group (35 cases). The presence of TR in each group was studied by two-dimensional color flow mapping using a Toshiba SSH-65A apparatus. The incidence of TR was 49% in the MR(+) group and 34% in the MR(-) group, and both (35 cases). The presence of TR in each group was studied by two-dimensional color flow mapping using a Toshiba SSH-65A apparatus. The incidence of TR was 49% in the MR(+) group and 34% in the MR(-) group, and both values were statistically greater than 9% in the control group (p less than 0.001 and p less than 0.05, respectively). A female preponderance was observed only in the MR(+) group. Tricuspid valve prolapse was observed in six cases (10%) in the MR(+) group, two cases (6%) in the MR(-) group, and none in the control group. The mean tricuspid ring dimension did not differ significantly among the three groups. The female patients in MR(+) group had statistically greater measurements than the normal female subjects (p less than 0.01). In conclusion, the incidence of TR was statistically greater in female patients in the MR(+) group than in females in the other groups. It is suspected that functional or pathological changes which induce MVP are likely to progress to the tricuspid ring in female patients.

Adolescent↗
PubMed1986

Reliability of non-invasive estimates of pulmonary hypertension by pulsed Doppler echocardiography.

The duration of the acceleration phase of pulmonary systolic flow was measured by pulsed Doppler echocardiography in 39 normal subjects and 67 patients with heart disease to evaluate the reliability of this Doppler index as an estimate of pulmonary arterial pressure. The mean (SD) Doppler index in patients with abnormal mean pulmonary arterial pressure (greater than 15 mm Hg) was significantly shorter than that in normal subjects (110 (30) ms vs 150 (10) ms). The Doppler index was significantly related to the mean pulmonary arterial pressure (r = -0.75) the pulmonary blood flow (r = 0.46), and the total pulmonary vascular resistance (r = -0.68). Forty four of 45 patients with an abnormal index (less than or equal to 120 ms) showed abnormal mean pressure (greater than 15 mm Hg). Without exception patients with a low index (less than or equal to 90 ms) had distinct pulmonary hypertension (greater than or equal to 25 mm Hg). Twelve of 22 patients with a normal index (greater than or equal to 130 ms), however, also showed abnormal pressures. Nine of the 12 had an atrial septal defect and they had high pulmonary arterial pressure associated with high blood flow. Eighteen patients with valvar heart disease, whose mean pulmonary arterial pressure ranged from 16 mm Hg to 24 mm Hg, had a significantly shorter acceleration phase and a higher total vascular resistance than 11 patients with atrial septal defect in whom the pressure range was similar (120(20) ms vs 140 (20) ms, 3.8 (1.1) hybrid resistance unit vs 1.6 (0.5)). Thus although the acceleration time of the pulmonary systolic flow is useful for the evaluation of pulmonary hypertension, it is a complex index that is affected not only by pulmonary arterial pressure but also by pulmonary blood flow and pathological changes in the pulmonary vascular bed.

Adult↗
PubMed1986

[Mitral regurgitation due to abnormal reinsertion of chordae tendineae (looping) of the posterior mitral leaflet: clinical and echocardiographic features].

Two-dimensional (2D) echocardiographic and clinical characteristics of patients with mitral regurgitation (MR) due to abnormal reinsertion of chordae tendineae (looping) in the middle scallop of the posterior leaflet were described and compared with those of patients with chordal rupture of the posterior leaflet. Twenty-five patients with posterior mitral valve prolapse who underwent mitral valve replacement were studied. They were categorized in three groups; 14 patients with MR due to ruptured chordae tendineae (RCT) of the posterior leaflet (RCT group); three patients with looping of the chordae tendineae in the middle scallop of the posterior leaflet (looping group); and eight patients with both RCT and looping (looping + RCT group). It was difficult to distinguish the looping group from the other two groups by their 2D echocardiographic findings, which were characteristic of those of RCT. However, the following findings were more frequently encountered in the patients with looping than in those without: 1) aberrant or absent systolic coaptation with salient arc of the posterior leaflet, observed in six of the RCT group (43%), two in the looping group (67%) and seven in the looping + RCT group (88%); 2) with thickened edges of the posterior leaflet, shown in three of the RCT group (21%), two of the looping group (67%) and five of the looping + RCT group (63%) in the long-axis view, and also noticed in four of the RCT group (29%), two of the looping group (67%) and six of the looping + RCT group (75%) in the short-axis view. In the clinical history, the onset of a heart murmur, congestive heart failure and surgical treatment occurred at significantly younger ages in the looping group than in the RCT group. As for hemodynamic parameters, pulmonary hypertension was significantly milder in the looping group than in the RCT group. In conclusion, although 2D echocardiographic findings of patients with looping were similar to those of patients with RCT, it seemed possible to differentiate the looping group from the RCT group by the 2D finding of a prolapsed posterior mitral valve with a salient arc and a thickened edge. It was also suggested that the looping of chordae tendineae in the middle scallop of the posterior leaflet was congenital in origin.

Adolescent↗
PubMed1985

[Two-dimensional echocardiographic measurement of the surgical aortic ring: its clinical significance in non-rheumatic regurgitation and in predicting the sizes of prosthetic valves].

The purpose of the present study was to determine the usefulness of two-dimensional echocardiographic measurements of the surgical aortic ring diameters (ARDs) in predicting correct sizes of the prosthetic valves and in determining the mechanisms of aortic regurgitation. Forty patients with aortic regurgitation who underwent prosthetic valve surgery, and 20 normal controls were selected for the study. The 40 patients consisted of 21 with rheumatic aortic regurgitation (RHD group), and 19 with non-rheumatic non-inflammatory aortic regurgitation (non-RHD group). Aortic regurgitation due to annuloaortic ectasia with or without the stigmata of Marfan's syndrome and bicuspid aortic valves were excluded from the non-RHD group. Echocardiographic estimates of the ARDs proved to be useful for predicting prosthetic valve sizes considering the good correlation between the echocardiographic and direct measurements (r = 0.814), despite a slight tendency to echocardiographic underestimation. The ARDs was 24.7 +/- 3 mm in the RHD group, 28.8 +/- 2.9 mm in the non-RHD group and 21.8 +/- 1.7 mm in the normal controls. The ARDs in the RHD group was significantly larger than that of the normal controls (p less than 0.001), and the ARDs of the non-RHD group was significantly larger than that of the RHD group (p less than 0.001). There were loose correlations between the ARDs and left ventricular end-diastolic dimension, and between the ARDs and left ventricular end-systolic dimension in the RHD group (r = 0.549 and r = 0.455, respectively), but there were no correlations between these two parameters in the non-RHD group. In four patients with aortic regurgitation in the non-RHD group, mitral regurgitation coexisted. Both the ARDs and the mitral ring dimension were markedly increased in these patients. It is concluded that in the non-RHD group, marked dilatation of the ARDs appears to be one of the cause of aortic regurgitation.

Adult↗
PubMed1985

[Quantitative analysis of myocardial perfusion by digital subtraction angiography].

Digital subtraction angiography (DSA) has been adopted to detect ischemic myocardial areas and to quantitatively evaluate the degrees of myocardial perfusion abnormalities. Subtraction for selective coronary arteriography was performed sequentially between mask and enhanced images in the same cardiac phases by means of ECG signals. We obtained three distinct perfusion phases which we termed the arterial, capillary, and venous phases. Densitometry of the circumferential cardiac wall was performed on these sequential images. The results were compared with 201Tl myocardial scintigrams and cine angiograms. In the arterial phase, the abnormalities of the coronary artery, such as stenosis, obstruction and collaterals were represented. In the capillary phase, contrast materials served as markers of myocardial perfusion and delineated infarctions as areas of low contrast enhancement compared to the normally perfused myocardium. In the venous phase, the infarcted areas were represented as areas with greater relative contrast enhancement than that of the normal myocardium. Circumferential analysis of perfusion could provide more detailed information about myocardial ischemic areas and the degrees of ischemia. Although we used invasive selective coronary arteriography, DSA techniques have numerous merits such as excellent temporal resolution, spatial resolution, and good contrast resolution, over conventional methods. Quantitative DSA methodology which we developed provided not only anatomical information about the main coronary arteries but new information about abnormalities of peripheral myocardial perfusion.

Angiography↗
PubMed1985

[Regional myocardial perfusion abnormality detected by digital subtraction angiography in a case of patent ductus arteriosus with coronary arterial fistulae].

A 19-year-old woman with patent ductus arteriosus and increasingly severe chest pain received various examinations including exercise stress radionuclide test, which revealed hypokinesis and decreased myocardial perfusion in the apex and left ventricular dilatation. Conventional selective coronary arteriography and newly-developed ECG synchronized digital subtraction angiography (DSA) were performed to identify the genesis of her myocardial ischemia. Selective coronary arteriography revealed congenital coronary arterial fistulae in the right and left coronary arteries. The largest fistula was observed around the obtuse marginal artery terminating in the left ventricle. Although stenosis of the left circumflex and left anterior descending arteries (LAD) were not observed, the LAD appeared to be hypoplastic. Hypoplasia of the LAD and the steal phenomenon by arterial fistula could have been responsible for the myocardial ischemia in the apex, but this method did not clearly reveal the area and the degree of myocardial ischemia in the apex. Sequentially subtracted images during the arterial and capillary phases were obtained by utilizing ECG-synchronized DSA for selective coronary arteriography. For these images, densitometric analysis was adapted to the myocardial region, i.e. circumferential densitometry using 21 segments around the left ventricular wall. Decreased myocardial perfusion was clearly demonstrated in the apex in capillary phase images. Moreover, circumferential analysis provided detailed information about the area and the degree of impaired peripheral circulation in the myocardium. This analysis by DSA may prove useful for evaluating myocardial perfusion abnormalities.

Adult↗
PubMed1984

[Hemodynamic determinants of late systolic reversed flow in the main pulmonary artery in pulmonary hypertension: a pulsed Doppler echocardiographic study].

Pulsed Doppler echocardiograms of the main pulmonary artery were evaluated in 46 cases including 23 cases with valvular heart disease, 13 with an intracardiac shunt, two with severe right ventricular failure and low cardiac output state, and eight healthy normals. In each Doppler echocardiogram the sample volume was placed at well defined nine locations within the main pulmonary artery. Among 23 cases with valvular heart disease, 10 cases with pulmonary hypertension showed a late systolic reversed flow ("rebound" pattern : type B) in all nine sample volumes examined. This pattern was neither detected in any cases with normal pulmonary arterial pressure, cases with an intracardiac shunt, cases with low cardiac output state, nor healthy normals. A comparative study of 10 cases with "rebound" pattern (type B) and 13 cases without it disclosed that the former had a significantly increased pulmonary arterial pressure (30.9 + 15.1 mmHg vs 17.8 +/- 9.0 mmHg, p less than 0.001), an increased total pulmonary resistance (789 +/- 496 dynes X cm X sec-5 vs 285 +/- 170 dynes X cm X sec-5, p less than 0.001) and a decreased pulmonary arterial compliance expressed as stroke volume divided by pulmonary arterial pulse pressure (1.75 +/- 0.94 ml/mmHg vs 3.80 +/- 1.65 ml/mmHg, p less than 0.01). Mean acceleration of the pulmonary ejection expressed as peak flow velocity divided by acceleration period was also significantly larger in cases with "rebound" pattern (type B) than in cases with "normal" pattern (938 + 255 cm X sec2 vs 675 +/- 160 cm X sec2, p less than 0.01). In conclusion, "rebound" pattern (type B) in pulmonary hypertension is not simple swirl formation, but a totally reversed late systolic flow in the main pulmonary artery, which is caused by sudden interruption of the distal run-off due to markedly elevated total pulmonary resistance under normal right ventricular ejection.

Adolescent↗