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Biomedical subjects

J Yoshikawa

Publications and source records attributed to J Yoshikawa.

At least 271 records · Page 15Linked to original sources
PubMed1995

[Cardiac emergencies after the Hanshin (Kobe-Osaka) earthquake].

The Hanshin earthquake occurred on January 17, 1995, causing considerable disruption at our hospital due to lack of water and gas supplies for about 5-6 weeks after the earthquake. We admitted 63 cardiac patients as emergencies during first 3 weeks, including 32 with congestive heart failure, 6 with unstable angina, 8 with acute myocardial infarction and 17 with other diseases. Congestive heart failure occurred mainly in aged patients who suffered from upper respiratory infection or bronchitis. We were obliged to send 20 critically ill cardiac patients to other cardiac centers by helicopter or ambulance, because no intensive care could be provided. Major and high grade hospital functions cannot be achieved in earthquake areas.

Disasters↗
PubMed1995

[Mitral valve repair for infectious endocarditis].

Fourteen patients with mitral regurgitation resulting from infectious endocarditis underwent mitral valve repair between December 1988 and July 1994. There were nine males and five females aged from 14 to 70 years (mean 40.2 +/- 19.7 years). Three patients had active endocarditis. Time between the onset of endocarditis symptoms and surgery ranged from 1 to 24 months (mean 8.3 months). Bacterial findings were Streptococcus in eight patients, Staphylococcus in one, and unknown in five. All macroscopically infected tissue was excised in patients with active endocarditis. Carpentier's reconstructive techniques were mainly used. There were no hospital deaths. Mean follow-up was 29 months and complete. Thirteen patients were in New York Heart Association functional class I and one in class II. There were no late deaths, reoperations, recurrent endocarditis, thromboembolic events, or other valve-related morbidity. We conclude that mitral valve repair is an attractive procedure in patients with mitral regurgitation resulting from infectious endocarditis.

Adolescent↗
PubMed1995

[Assessment of coronary stenosis severity using a Doppler guide wire in vivo: is the continuity equation applicable to moderate to severe coronary artery stenosis?].

The usefulness of a Doppler guide wire was evaluated in the estimation of coronary stenosis severity in patients with moderate to severe coronary stenosis using the continuity equation. The maximal coronary flow velocities (V) proximal to the stenosis (p), at the stenosis (s), and distal to the stenosis (d) were measured using a Doppler guide wire (12-MHz, 0.018-in) in 12 patients with mild coronary stenosis (less than 50% diameter stenosis: group A) and 12 patients with moderate to severe coronary stenosis (more than 50% diameter stenosis: group B). Percent diameter stenosis (%DS) was calculated from Vp/Vs by: %DS = (1 - square root of Vp/Vs) x 100 (%) (Vp = the maximal velocity proximal to the stenosis; Vs = the peak velocity at the stenotic site) Percent DS was calculated from Vd/Vs by: %DS = (1 - square root of Vd/Vs) x 100 (%) (Vd = the peak velocity distal to the stenosis) Regression of Doppler-derived %DS from Vp/Vs compared to quantitative coronary angiographic % DS were: Group A: y = 0.83x + 3.0 (r = 0.79), Group B: y = 0.63x + 9.4 (r = 0.81), Overall: y = 0.63x + 9.6 (r = 0.91) Regression of Doppler-derived %DS from Vd/Vs compared to quantitative coronary angiographic %DS were: Group A: y = 0.98x - 1.0 (r = 0.81), Group B: y = 0.67x + 14.6 (r = 0.84), Overall: y = 0.79x + 7.6 (r = 0.91) The continuity equation method using a Doppler guide wire underestimates coronary stenosis severity in patients with moderate to severe coronary stenosis, although Doppler-derived %DS is correlated with angiographic %DS.

Blood Flow Velocity↗
PubMed1995

[Adenosine triphosphate loading thallium-201 myocardial scintigraphy: optimal dose and diagnostic accuracy].

Adenosine triphosphate (ATP) is an alternative to dipyridamole or adenosine in thallium-201 myocardial scintigraphy. However, the optimal dose of ATP has not been determined. A Doppler guide wire study showed the coronary flow velocity at a dose of 0.15 mg/kg of ATP was equal or higher than that at 0.14 mg/kg of adenosine or 0.56 mg/kg of dipyridamole. ATP was given intravenously to 67 patients with coronary artery disease at 0.15 mg/kg/min for 6 min. Thallium-201 was injected at 3 min, followed by immediate and delayed (3 hrs) tomographic imaging. There was no serious side effect during examination, although chest pain (26%), dyspnea (17%), and flushing (33%) were common. The sensitivity and specificity to detect coronary artery disease were 98 and 100%, respectively. The sensitivity to detect left anterior descending artery, left circumflex artery, and right coronary artery lesions was 94, 59 and 77%, respectively. ATP loading thallium-201 scintigraphy provides an accurate diagnosis of coronary artery disease. The optimal dose of ATP is 0.15 mg/kg/min for 6 min.

Adenosine Triphosphate↗
PubMed1995

[Relationship between regional flow reserve supplied by the great saphenous vein graft and regional left ventricular wall motion: a Doppler guide wire study].

The relationship between regional flow reserve supplied by a great saphenous vein graft and myocardial infarction and anterior wall motion assessed by left ventriculography was studied in 28 patients with no stenosis in the great saphenous vein graft and the peripheral site of the recipient left anterior descending coronary arteries. The proximal segment to the anastomosis was totally or subtotally occluded. The resting graft blood flow velocity was measured using a Doppler guide wire, then 0.56 mg/kg of dipyridamole was injected for 4 minutes intravenously and the resultant increase in graft blood flow velocity was recorded. The regional flow reserve of the anterior wall supplied by great saphenous vein grafts in 11 patients with anterior myocardial infarction (MI group) was significantly lower than that in 17 patients without myocardial infarction (non-MI group) (1.5 +/- 0.3 vs 2.6 +/- 0.7, p < 0.01). The flow reserve supplied by great saphenous vein grafts in 11 patients with normal anterior wall motion was 2.8 +/- 0.7, 10 with hypokinesis 1.9 +/- 0.3, and with akinesis 1.3 +/- 0.3. Reduced anterior wall motion induced a significant decrease in the flow reserve of the anterior wall supplied by the great saphenous vein graft (p < 0.01). The anterior wall motion score of four segments assessed by left ventriculography showed a significant correlation with the flow reserve of the anterior wall supplied by the great saphenous vein graft (y = -0.24 x + 3.7, r = 0.75, p < 0.001). The results show infarcted myocardium was an important influence on coronary flow reserve.

Adult↗
PubMed1995

[Experimental study on embolic materials for simultaneous segmental embolization through transarterial route].

To determine suitable embolic materials for simultaneous arterioportal embolization through the arterial route, transcatheter arterial embolization (TAE) using iodized oil (Lipiodol) mixed with monomeric n-butyl-2-cyanoacrylate, with absolute ethanol, or mixed with Gelfoam powder was carried out in 14 dogs. Following TAE, the distribution of Lipiodol in hepatic artery, peribiliary plexus, and portal vein was analyzed by soft tissue x-ray radiography and en bloc silver impregnation. As a result, Lipiodol mixed with absolute ethanol, and Gelfoam powder was considered to be the most reasonable embolic materials for this purpose.

Animals↗
PubMed1995

[Intravascular ultrasound scanning assessment of plaque distribution in the left anterior descending coronary artery just distal to the bifurcation].

Coronary plaque has a distinct spatial distribution with the peak incidence on the outer wall around the bifurcation of the left main coronary artery. Intravascular ultrasound scanning was used to evaluate the distribution of the plaque in the proximal site of the left anterior descending coronary artery in 16 patients. Coronary angiography showed the examined sites were normal in all patients. A cross-sectional coronary scan was recorded in the left anterior descending coronary artery just distal to the bifurcation using a 4.3 Fr, 30 MHz intravascular ultrasound catheter. The thickness of the plaque was measured at 0, 90, 180, and 270 degrees, where 0 degree indicates the left circumflex coronary artery branching direction. The scan was divided into four areas of 90 degrees and labeled 1 to 4 in the counterclockwise direction (site 1 was the left circumflex coronary artery branching direction). The thickness and area of the plaque were measured in each site. The percentage plaque fraction was calculated as (plaque area in each site)/(plaque area of all) x 100. In 15 (94%) of the 16 patients, images of crescent shaped plaques were obtained. The mean thicknesses of the plaque at sites 1-4 were 0.25 +/- 0.07 mm, 0.46 +/- 0.21 mm, 0.82 +/- 0.19 mm, and 0.42 +/- 0.23 mm, respectively. The mean percentage plaque fractions were 7.9 +/- 3.6% (site 1), 18.1 +/- 7.2% (site 2), 55.0 +/- 8.1% (site 3), 18.7 +/- 6.9% (site 4), respectively. In site 3, opposite to the left circumflex coronary artery branching, the thickness and percentage plaque fraction were significantly greater than the remaining three sites (p < 0.001). In vivo intravascular ultrasound scanning revealed that coronary plaque in angiographically normal left anterior descending coronary artery just distal to the bifurcation has a distinct distribution with a peak incidence opposite to the left circumflex coronary artery branching.

Aged↗
PubMed1995

Three-dimensional analysis of configuration and dynamics in patients with an annuloplasty ring by multiplane transesophageal echocardiography: comparison between flexible and rigid annuloplasty rings.

BACKGROUND AND AIM OF THE STUDY: Multiplane transesophageal echocardiography provides three-dimensional reconstruction of the mitral annulus from multiple cross-sectional views from a stable transducer position by rotating around a central axis. This study was designed to evaluate the effect of the type of annuloplasty ring on mitral annular configuration and dynamics using three-dimensional reconstruction by multiplane transesophageal echocardiography. METHODS: Ten patients who underwent mitral valve repair for pure mitral regurgitation (five patients with flexible Duran ring, five patients with rigid Carpentier ring) and five normal subjects were studied with multiplane transesophageal echocardiography. Three-dimensional configuration of the mitral annulus was obtained from multiple cross-sectional views of multiplane transesophageal echocardiography. RESULTS: In normal subjects, the mitral annulus had a non-planar configuration and reduced its area in systole. In patients with a Duran ring, the mitral annulus had a non-planar configuration and reduced its area in systole. In patients with a Carpentier ring, the mitral annulus had a planar configuration and the mitral annular area did not change during the cardiac cycle. CONCLUSION: Three dimensional reconstruction of the mitral annulus using multiplane transesophageal echocardiography revealed that mitral annular configuration and dynamics are more physiologic in patients with a flexible Duran ring that with a rigid Carpentier ring.

Echocardiography, Transesophageal↗
PubMed1994

Subsegmental transcatheter arterial embolization for small hepatocellular carcinomas: local therapeutic effect and 5-year survival rate.

The local therapeutic effects and 5-year survival rates obtained following subsegmental transcatheter arterial embolization (TAE) therapy for small hepatocellular carcinomas (HCCs) were retrospectively analyzed. A total of 124 nodular-type HCC lesions measuring less than 4 cm in diameter in 100 patients with liver cirrhosis were subjected to the analysis. All lesions became opaque on digital subtraction angiography. Complete necrosis was seen in 64% of 11 resected lesions. Among the remaining 113 lesions, the 1- and 5-year local recurrence rates following one performance of TAE were 18% and 33%, respectively. The 1- and 5-year survival rates were 100% and 53%, respectively. No significant side effect was observed after TAE therapy. Subsegmental TAE therapy significantly improved the long-term survival rates of patients with small HCCs associated with liver cirrhosis as compared with those treated by conventional TAE therapy.

Adult↗
PubMed1994

Epidemiological survey of dementia and depression among the aged living in the community in Japan.

The authors surveyed the prevalence of depression and dementia in the elderly in Ohira town in Japan from 1989 to 1990. The total population of this town was 26,712, with 2,778 people aged 65 and above, constituting 10.4% of the total population. The prevalence of dementia (n = 128) was 6.1% and that of major depression (n = 9) was 0.4%, according to the DSM-III-R criteria. The prevalence of a depressive state which did not fulfill the criteria for major depression (n = 55) was 2.4%. The patients with multi-infarct dementia (n = 49) suffered from depression (42.8%) more frequently than those with dementia of the Alzheimer type (11.1%). The rate of depression coexisting with dementia increased with aging, while the rate of depression without dementia did not change in all the age groups.

Age Distribution↗
PubMed1994

Pseudolesion in segment IV of the liver at CT during arterial portography: correlation with aberrant gastric venous drainage.

PURPOSE: To analyze the correlation between pseudolesions seen in segment IV of the liver and aberrant gastric venous drainage (AGVD). MATERIALS AND METHODS: Twenty-two patients with a pseudolesion in the posterior edge of segment IV of the liver (group A) and 100 randomly selected patients without pseudolesions (group B) underwent computed tomography during arterial portography (CTAP) and hepatic arteriography. The frequency of the visualization of AGVD to segment IV was compared for groups A and B. RESULTS: AGVD was seen at arteriography in 18 of 22 patients in group A. None of the patients in group B had AGVD. The difference in the frequency of angiographically visible AGVD was statistically significant (chi 2 test, P < .01). CONCLUSION: AGVD is the main cause of pseudolesions in the posterior edge of segment IV of the liver.

Diagnosis, Differential↗
PubMed1994

Segmental iron deposition in the liver due to decreased intrahepatic portal perfusion: findings at MR imaging.

PURPOSE: To evaluate the causes of intrahepatic segmental areas of signal hypointensity [corrected] on T1- and T2-weighted spin-echo (SE) and gradient-echo (GRE) magnetic resonance (MR) images. MATERIALS AND METHODS: Six patients in whom wedge-shaped hypointense areas were seen on hepatic MR images underwent examination with ultrasound (US), computed tomography (CT), angiography, and CT during arterial portography (CTAP). Histologic examination was performed in three patients. RESULTS: The affected liver parenchymas were best depicted as segmental or lobar hypointense areas on GRE images. Angiography and CTAP revealed that portal blood supply to the hypointense areas was absent or decreased due to portal vein tumor thrombus and arterioportal shunt (n = 1), compression of a portal branch by tumor (n = 2), portal vein thrombosis (n = 1), or arterioportal shunt (n = 2). Iron deposition in the hepatocytes was evident in all three patients with histologic correlation. CONCLUSION: Segmental signal hypocoagulability was generally due to hepatocyte iron deposition and was accompanied and possibly caused by a disturbance in portal flow.

Adult↗
PubMed1994

Small pancreatic adenocarcinomas: efficacy of MR imaging with fat suppression and gadolinium enhancement.

PURPOSE: To compare the efficacy of fat-suppressed T1-weighted magnetic resonance (MR) imaging and dynamic MR imaging in the diagnosis of small pancreatic adenocarcinomas. MATERIALS AND METHODS: Pancreatic adenocarcinomas in 15 patients were evaluated with dynamic computed tomography (CT) and five MR imaging sequences that included fat-suppressed T1-weighted technique and dynamic multiplanar gradient-recalled acquisition in the steady state technique. RESULTS: The difference in contrast-to-noise ratios between tumor and normal pancreas was significantly different (P < .05) between the five MR imaging sequences used. In six patients, the combination of dynamic MR imaging and fat-suppressed imaging was superior to dynamic CT in the detection of tumors. Tumors accompanied by chronic pancreatitis were less distinct on fat-suppressed images but were clearly visible on dynamic MR images. Peripancreatic extension of tumors was better recognized on T1-weighted images and CT scans than on fat-suppressed images. CONCLUSION: Fat-suppressed T1-weighted images and dynamic MR images were useful in the detection of pancreatic carcinomas. T1-weighted images and CT scans were superior in the evaluation of tumor extension.

Adenocarcinoma↗