Search PubMed⌕ Search

Biomedical subjects

J Yoshikawa

Publications and source records attributed to J Yoshikawa.

At least 253 records · Page 14Linked to original sources
PubMed1996

[Pulmonary actinomycosis--diagnosis and therapy based on past reports of actinomycosis].

A 57-year-old man who complained of bloody sputum was admitted to the hospital because of a spherical mass on a chest X-ray film. Despite a detailed examination, no definitive diagnosis was obtained, and a left lower lobectomy was done. Histopathologic examination of tissue from the resected lobe revealed sulfur granules and branching filamentous bacteria, and therefore pulmonary actinomycosis was diagnosed. Examination of reports published in Japan in the last five years suggested a slight increase in the frequency of diagnosis before treatment of actinomycosis and a slight decrease in the frequency of surgical treatment. However, these changes are not surprising because the frequency of surgical treatment is 58%. These findings suggest that pulmonary actinomycosis should be included in the differential diagnosis of a mass on a chest X-ray film.

Actinomycosis↗
PubMed1996

[Serial change of mitral regurgitation after anterior mitral valve repair using polytetrafluorethylene chordae: evaluation by transesophageal echocardiography].

The results of anterior mitral leaflet repair were evaluated by the serial change of mitral regurgitation (MR) using transesophageal echocardiography (TEE) in 24 patients undergoing mitral valve repair for anterior leaflet prolapse during 1988 to 1994, who were examined by TEE immediately after operation, 1 month after operation, and late after operation (mean 15 months). Chordal replacement using polytetra-fluorethylene chordae was performed in 15 patients (PTFE group), and not performed in 9 patients (non-PTFE group). MR jet area late after operation was significantly smaller in the PTFE group than in the non-PTFE group (2.2 +/- 2.3 vs. 4.6 +/- 2.3 cm2, p < 0.05). Moderate to severe MR was observed in four patients (27%) in the PTFE group, and six (67%) in the non-PTFE group late after operation. The thickness of the mitral leaflet before operation was more than 5 mm in all patients with more than moderate MR late after operation in the PTFE group. Chordal replacement using polytetrafluorethylene chordae showed better results compared with conventional mitral valve repair without polytetrafluorethylene chordae over the follow-up period of 15 months.

Aged↗
PubMed1996

[Prognostic value of serial Doppler echocardiographic follow-up of transmitral flow patterns in patients with congestive heart failure who presented with pulmonary edema].

The predictive value of serial Doppler echocardiographic follow-up of transmitral flow patterns for the prognosis of patients with congestive heart failure who presented with pulmonary edema was evaluated in 80 consecutive patients with decreased left ventricular systolic function (ejection fraction < 40%). Restrictive patterns [peak early diastolic filling velocity (E)/peak late diastolic filling velocity (A) ratio (E/A) > 2 and/or deceleration time for E wave to decline to baseline (DcT) < 150 msec] were observed in 72 patients (90%) on admission. After intensive therapy, DcT showed a nonrestrictive pattern in 38 of 72 patients (53%). The survival rates at 1 year was 50% for the restrictive group, and 97% for the nonrestrictive group. E/A showed a nonrestrictive pattern in 37 of 56 patients (66%). The survival rates at 1 year was 86% for the restrictive group, and 58% for the nonrestrictive group. Serial Doppler echocardiographic follow-up of transmitral flow patterns is useful in predicting the prognosis in patients with congestive heart failure who presented with pulmonary edema.

Aged↗
PubMed1996

[Valvuloplasty for aortic insufficiency in a patient with bicuspid aortic valve].

A 20-year-old man with a bicuspid valve underwent aortic valvuloplasty for aortic regurgitation. Valvuloplasty was performed according to Cosgrove's method. Intraoperative transesophageal color Doppler echocardiography showed trivial aortic regurgitation after the repair. Peak pressure gradient across the repaired aortic valve was 9.3 mmHg at rest (cardiac output 4.2 l/min, stroke volume 49 ml) and 27.6 mmHg at dobutamine infusion (cardiac output 8.7 l/min, stroke volume 78 ml). The patient was in NYHA class I with no medication after surgery. Valvuloplasty for aortic regurgitation with a bicuspid valve is the surgical procedure of choice.

Adult↗
PubMed1995

Flow capacity of internal mammary artery grafts: early restriction and later improvement assessed by Doppler guide wire. Comparison with saphenous vein grafts.

OBJECTIVES: The purpose of this study was to assess flow dynamics and flow capacities of internal mammary artery and saphenous vein grafts to the left anterior descending coronary artery. BACKGROUND: The postoperative flow capacity of internal mammary artery grafts to the left anterior descending coronary artery has been reported to be restricted compared with that of saphenous vein grafts in studies using radionuclide angiography. A recently developed Doppler guide wire has been used to analyze the flow dynamics of bypass grafts and to clarify the mechanism of this limited flow capacity. METHODS: Phasic flow velocity recordings were obtained in the midportion of the bypass graft and within the native left anterior descending artery, using a 0.018-in. (0.046-cm) 12-MHz Doppler guide wire, in 53 patients: 27 patients with an internal mammary artery graft (16 with a new graft assessed 1 month postoperatively and 11 with an old graft assessed at 1 year) and 26 patients with a saphenous vein graft (13 with a new graft assessed 1 month postoperatively and 13 with an old graft assessed at 1 year). All patients were studied at baseline rest and during hyperemia induced by intravenous infusion of dipyridamole, 0.56 mg/kg body weight, over 4 min. RESULTS: In the left anterior descending artery itself, systolic and diastolic peak velocities, the time average of the instantaneous spectral peak velocity (time-averaged peak velocity), vessel diameter and the calculated flow volume did not differ significantly among the four graft groups. The time-averaged peak velocity was significantly greater for new than for old arterial grafts or for new or old vein grafts (mean +/- SD 27 +/- 9 vs. 19 +/- 6, 11 +/- 5 and 12 +/- 6 cm/s, respectively, p < 0.01). However, because the diameter of new arterial grafts was significantly smaller than that of the other three grafts (2.4 +/- 0.1 vs. 2.9 +/- 0.2 [p < 0.05], 3.6 +/- 0.6 [p < 0.01] and 3.4 +/- 0.5 mm [p < 0.01], respectively), there was no difference in calculated flow volumes at rest (62 +/- 17 vs. 58 +/- 15, 61 +/- 18 and 58 +/- 19 ml/min, respectively, p = NS) between new arterial grafts and the other grafts. Although the maximal time-averaged peak velocity during hyperemia was significantly greater in new than in old arterial grafts or new or old vein grafts (47 +/- 17 vs. 40 +/- 7, 31 +/- 8 and 34 +/- 12 cm/s, respectively, p < 0.01), the flow reserve of new arterial grafts was significantly smaller than that of the other three groups (1.8 +/- 0.3 vs. 2.6 +/- 0.3, 2.8 +/- 0.5 and 3.0 +/- 0.6, respectively, p < 0.01) because the baseline time-averaged peak velocity of these new grafts was far greater than that of the other groups. CONCLUSIONS: Internal mammary artery graft flow early after operation is characterized by a higher rest velocity than that of vein graft flow. This high velocity maintains flow volume at baseline condition in compensation for the smaller diameter. Although flow reserve does not differ significantly between new and old vein grafts, that for internal mammary artery grafts is significantly reduced soon after bypass surgery. This restricted flow capacity improves late postoperatively because of an increase in diameter and a decrease in flow velocity from baseline levels.

Adult↗
PubMed1995

Intravenous dopexamine in the treatment of acute congestive heart failure: results of a multicenter, double-blind, placebo-controlled withdrawal study.

Acute hemodynamic effects of intravenous infusion of dopexamine were evaluated by a placebo-controlled withdrawal study in patients with acute congestive heart failure. Twenty patients were enrolled at 10 centers in Japan. All patients had a pulmonary capillary or diastolic pressure of 15 mmHg or greater and a cardiac index of 2.5 l/min/m2 or less. Phase I: Intravenous dopexamine was introduced in a single-blind, uncontrolled fashion at the rate of 0.5 micrograms/kg/min and was titrated up to achieve a 30% or more increase in the cardiac index. Two patients withdrew from the study due to sinus tachycardia and ventricular ectopy or exacerbation of heart failure. Phase II: The remaining 18 responders who were free of limiting side effects were randomized in double-blind fashion to continue dopexamine or to switch to placebo for an additional 60 minutes. At the end of phase II, the hemodynamic improvement obtained in phase I of the study disappeared completely after substitution of placebo but was maintained in dopexamine-treated patients. Our findings suggest that dopexamine, when given in appropriate doses to selected patients, shows balanced vasodilator action suitable for the treatment of acute congestive heart failure.

Acute Disease↗
PubMed1995

Postoperative flow characteristics of left internal thoracic artery grafts.

Twenty patients whose left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) underwent postoperative coronary angiography and Doppler ultrasound velocimetry. During angiography, the diameter of the LITA conduit was measured at three points: proximal, mid, and distal. The degree of left anterior descending artery stenosis proximal to the anastomotic site was evaluated by densitometry. The LITA flow velocity pattern was obtained at the three points to calculate the total, systolic, and diastolic flow volume. There were significant differences in the total LITA flow among the three points (proximal, 36.0 +/- 17.2 mL/min; mid, 29.9 +/- 15.2 mL/min; distal, 27.2 +/- 14.0 mL/min; p < 0.001 between the proximal and the mid or distal portions). The degree of left anterior descending artery stenosis affected the distal LITA flow and diameter (r = 0.823 and 0.811, respectively). There were significant differences in the systolic LITA flow among the three points (proximal, 13.2 +/- 6.5 mL/min; mid, 8.1 +/- 4.7 mL/min; distal, 5.6 +/- 3.4 mL/min; p < 0.001 between the proximal and the mid or distal portions). However, there was no statistically significant difference in the diastolic LITA flow among the three points (proximal, 22.9 +/- 11.0 mL/min; mid, 21.7 +/- 10.8 mL/min; distal, 21.6 +/- 10.8 mL/min). We conclude that a lower degree of LAD stenosis significantly reduces the LITA flow, inducing the string phenomenon. Additionally, during the diastolic phase, the LITA graft transports the blood primarily to the coronary artery but not to the side branches. Therefore, the steal phenomenon might not apply in the setting of an LITA graft.

Adult↗
PubMed1995

Comparison of the Carpentier and Duran prosthetic rings used in mitral reconstruction.

This clinical study was undertaken to evaluate the Duran flexible ring and the Carpentier rigid ring in terms of mitral annulus motion, transmitral flow and left ventricular function. Twenty-six patients (11 receiving rigid rings and 15, flexible rings) with normal sinus rhythm and with no or only trivial mitral valve regurgitation after surgical repair were selected. Angiograms demonstrated no significant differences in left ventricular systolic function between the two groups of patients. The area of the mitral annulus with the flexible ring significantly changed during the cardiac cycle. There were significant differences in the left ventricular fractional shortening (rigid ring, 35.8%; flexible ring, 43.4%) and in the peak velocity (rigid ring, 222 cm/s; flexible ring, 186 cm/s) at peak exercise. These data suggest that the flexible ring interferes less with the normal movements of the mitral annulus during the cardiac cycle, and that, under exercise conditions, it performs better than the rigid ring. We therefore conclude that mitral valve reconstruction using the Duran flexible ring is advantageous in patients with mitral regurgitation due to degenerative disease and sinus rhythm.

Adult↗
PubMed1995

Hepatocellular carcinoma: CT appearance of parenchymal changes after percutaneous ethanol injection therapy.

PURPOSE: To evaluate the changes in surrounding liver parenchyma after treatment of hepatocellular carcinoma (HCC) and borderline malignant lesions with percutaneous ethanol injection (PEI). MATERIALS AND METHODS: The authors reviewed the findings at computed tomography (CT) and CT during arterial portography (CTAP) obtained before and after PEI therapy for 32 lesions in 26 patients with HCC or adenomatous hyperplasia. Two surgically resected specimens were also histologically examined. RESULTS: In 10 (77%) of 13 lesions, decreased portal vein-related enhancement indicative of reduced portal blood flow in the periphery of the tumor was found at CTAP. Mild atrophy (concave liver surface), segmental atrophy, and lobar atrophy were found in 40%, 17%, and 3%, respectively. Histologic examination of the resected specimens revealed organized thrombi in the peripheral portal vein in the surrounding liver. CONCLUSION: PEI may cause decreased portal blood flow and atrophy in the noncancerous liver parenchyma that surrounds the tumor being treated.

Aged↗
PubMed1995

Aberrant gastric venous drainage in cirrhotic livers: imaging findings in focal areas of liver parenchyma.

PURPOSE: To analyze imaging finding in focal areas of liver parenchyma with aberrant gastric venous drainage (AGVD) in cirrhotic livers. MATERIALS AND METHODS: Eighteen patients with AGVD confirmed with computed tomography (CT) during arterial portography and arteriography underwent ultrasound (US) (n = 18), CT (n = 18), magnetic resonance (MR) imaging (n = 12), dynamic CT (n = 14), and dynamic MR imaging (n = 8). Imaging and histologic (n = 2) findings were analyzed. RESULTS: The focal area with AGVD was hypoechoic on US scans (n = 7), hypoattenuating on CT scans (n = 4), hyperintense on T1-weighted MR images (n = 6), and hypointense on T2-weighted MR images (n = 5). Early enhancement was seen with dynamic CT (n = 8) and with dynamic MR imaging (n = 6), without definite staining on arterial phase of arteriography. Histologic findings revealed hyperplastic changes of liver. CONCLUSION: The imaging findings, except for early enhancement, were very similar to those of adenomatous hyperplasia or well-differentiated hepatocellular carcinoma. The early enhancement was considered due to early venous return compared with that of the surrounding liver.

Adenoma↗
PubMed1995

Aldose reductase inhibitor prevents hyperproliferation and hypertrophy of cultured rat vascular smooth muscle cells induced by high glucose.

Vascular remodeling is a key process in the pathophysiology of atherosclerosis. Recent evidence suggests that high glucose levels may function as a vascular smooth muscle growth and proliferation-promoting substance. To explore the role of the polyol pathway in this process, we examined the effect of an aldose reductase inhibitor (ARI), epalrestat, on the growth characteristics of cultured rat vascular smooth muscle cells (VSMCs). Epalrestat (10 nmol/L, 1 mumol/L) significantly suppressed the high glucose-induced proliferative effect as measured by [3H]thymidine incorporation by 67% and 82% in cell number, suggesting ARI as an antimitogenic factor. In VSMCs, epalrestat (10 nmol/L, 1 mumol/L) significantly suppressed the high glucose-induced incorporation of [3H]leucine by 45% and 58% with the concomitant reduction of the cell size estimated by flowcytometry. Epalrestat (1 mumol/L) also suppressed high glucose-induced intracellular NADH/NAD+ increase and membrane-bound protein kinase C activation. These results indicate that this ARI possesses an antiproliferative and antihypertrophic action on VSMCs induced by high glucose possibly through protein kinase C suppression.

Aldehyde Reductase↗
PubMed1995

Focal sparing of segment IV in fatty livers shown by sonography and CT: correlation with aberrant gastric venous drainage.

OBJECTIVE: One of the most common sites of focal sparing in fatty livers (focal spared area) shown by sonography or CT is the posterior edge of segment IV. The differentiation of such a focal spared area from tumor has been a diagnostic challenge. The purpose of this study was to determine if a correlation exists between the focal spared area at the posterior edge of segment IV in fatty liver and the decrease of portal perfusion from the main portal vein due to aberrant gastric venous drainage directed into segment IV. SUBJECTS AND METHODS: Seventeen patients with fatty liver diagnosed on the basis of sonographic and CT findings who had hepatic arteriography and/or CT during arterial portography (CTAP) were included in the study. Seven patients had a focal spared area more than 2 cm in the longest diameter at the posterior edge of segment IV, and 10 patients did not have a focal spared area. The frequency of aberrant gastric venous drainage shown by arteriography (17 patients) and/or by CTAP (15 patients) was compared in the two groups of patients. RESULTS: Hepatic arteriography showed aberrant gastric venous drainage in all patients who had a spared area, and CTAP showed a portal perfusion defect at the posterior edge of segment IV in all five patients with a focal spared area who underwent CTAP. On the other hand, no definite aberrant gastric venous drainage and portal perfusion defect were seen in any patient without a spared area. The difference in the frequency of aberrant gastric venous drainage between the two groups of patients was statistically significant (chi-square test, p < .0001). CONCLUSION: Our results show that a strong correlation exists between the focal spared area at the posterior edge of segment IV in fatty liver and aberrant gastric venous drainage directed to segment IV. Focally decreased blood flow from the main portal vein associated with aberrant gastric venous drainage is a likely cause of the focal spared area. This fact is important for the differential diagnosis of hepatic tumors.

Adult↗
PubMed1995

[How to solve hospital operating problems based on the experience of the Hanshin earthquake?].

Immediately after the Hanshin (Kobe-Osaka) earthquake, electricity, water and gas supplies were discontinued at Kobe General Hospital, causing difficulties with many important hospital functions including the water cooled independent electric power plant, respirators, and sterilizers. A large water storage facility is needed to keep the water cooled type independent power plant operating. Alternative plans including the introduction of an air cooled independent power plant and a sea water to fresh water exchange system should be considered. Portable compressors are needed to retain the function of respirators in the absence of a water supply. The emergency use of propane gas should also be considered for sterilization and cooking facilities. There were very great problems in communication after the earthquake. The only method was the use of public phones, which have priority over private lines. Therefore, each hospital should have phones with similar priority. In addition, the use of personal computers and/or computer network methods should be considered to preserve a high level of communication after an earthquake. Otherwise, a hospital should be equipped with wireless phones. Immediately after the earthquake, the care of critically ill patients could not be achieved. Therefore, 20 cardiac patients requiring intensive care had to be transferred to other heart centers. The best method for the transfer is by helicopter. Kobe City suffered a transport crisis which occurred immediately after the earthquake and continued up to the end of March. A big helicopter or a special bus guided by a police car should be considered for hospital staff transport.(ABSTRACT TRUNCATED AT 250 WORDS)

Disasters↗
PubMed1995

[Pseudoxanthoma elasticum associated with unstable angina and Leriche syndrome: a case report].

A 64-year-old man with a history of intermittent claudication presented with chest pain. On admission, he had yellowish papules with a "plucked chicken" appearance on his neck. Histological examination of the biopsy specimen of the lesion revealed degeneration and calcification of elastic fibers in the dermis. His daughter also had similar histological changes in the skin. The diagnosis was pseudoxanthoma elasticum. Fundoscopic examination revealed angioid streaks. Electrocardiography showed inverted T waves in V2-V6, and echocardiography revealed hypokinesis in the anterior wall of the left ventricle. Emergency catheterization showed 90% stenosis in the left anterior descending coronary artery, total occlusion of the abdominal aorta, and severe stenosis in the right subclavian artery. He was treated medically and had no recurrent episodes of chest pain. A careful examination for cardiovascular diseases should be considered in patients with pseudoxanthoma elasticum.

Angina, Unstable↗
PubMed1995

[Effect of copper and copper binding protein on the CT attenuation value of liver: experimental study in rats].

We analyzed the effect of copper and copper binding protein on CT attenuation value in a rat model. CT attenuation values of the liver were compared with hepatic copper content and grade of orcein-positive granules, which are thought to be a counterpart of polymerized methalothionein in lysosomes. The difference between hepatic copper and CT attenuation value was not statistically significant (R = 0.056, p = 0.96). CT value had a positive correlation with the grade of orcein-positive granules (Rho = 0.755, p = 0.0001). We concluded that the CT attenuation value of liver can be elevated by rich polymerized methalothionein (copper binding protein) in lysosomes.

Animals↗
PubMed1995

[Detection of hibernating myocardium in patients with myocardial infarction by low-dose dobutamine echocardiography: comparison with thallium-201 scintigraphy with reinjection].

The identification of hibernating myocardium is important for selecting patients who will benefit from coronary revascularization. The relationship between echocardiographic and radioisotopic markers of hibernating myocardium and postrevascularization recovery of myocardial function was investigated in 21 patients who underwent successful revascularization. Each patient underwent low-dose dobutamine stress echocardiography and thallium-201 (201Tl) scintigraphy with reinjection before revascularization. The presence of contractile reserve in dobutamine stress echocardiography and Tl uptake in 201Tl scintigraphy with reinjection were defined as markers of hibernating myocardium. Follow-up echocardiograms were evaluated for improved regional wall motion in all patients at a mean of 8.6 months after revascularization. Sensitivity, specificity, and positive and negative predictive values of low-dose dobutamine stress echocardiography for indicating recovery of function after revascularization were 75.0%, 77.8%, 81.8%, and 70.0%, respectively. Sensitivity, specificity, and positive and negative predictive values of 201Tl scintigraphy with reinjection for indicating recovery of function after revascularization were 91.7%, 55.6%, 73.3%, and 83.3%, respectively. There were no statistical differences between low-dose dobutamine echocardiography and 201Tl scintigraphy in predicting postrevascularization recovery of function patients with hibernating myocardium.

Aged↗