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Biomedical subjects

S Shimokawa

Publications and source records attributed to S Shimokawa.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Double valve replacement with mechanical prostheses--an operative results].

From January 1980 to December 1993, sixty eight patients underwent double valve replacement with mechanical prostheses. There were forty males and twenty-eight females with a mean age of 49.6 years (ranging from 30 to 68 years). They were classified 10 of NYHA class IV, 28 of class III. Twelve patients had previous cardiac operation. TR was identified in 20 patients. DVR was performed in 53 patients, DVR + TVR in one, DVR + TAP in 13. Twenty-two had St. Jude Medical (SJM) prostheses and 46 had Björk-Shiley (BS) prostheses. Early death before 30 postoperative days occurred in 6 patients (8.8%). MOF was the most frequent cause for early death. The risk factors for early death were the NYHA class IV, infective endocarditis, longer duration of cardiopulmonary bypass, necessity of postoperative IABP support. Other factors such as emergency operation, previous operation, tricuspid valve surgery, duration of aortic cross clamp time were not the predictors for early death. Cumulative follow-up was 284.0 patient years (PY). The rate of late survival was 74.1% (40 patients). Linearized rates of thromboembolism (TE), prosthetic valve endocarditis (PVE), hemolysis (H), reoperation (RO) were 2.8%/PY, 0.7%/PY, 0.4%/PY, 1.1/PY respectively. The free rates from TE, PVE, H, RO at nine years were 75.6%, 96.2%, 93.1%, and 89.8%, respectively. The cumulative survival rates at 14 years were 53.2% in over-all patients, and 64.3% in hospital survivors. We conclude that the early surgery is recommended for the patients with multiple valvular heart disease. The late outcomes of DVR with SJM or BS mechanical prosthesis is an acceptable one.

Adult↗
PubMed1995

[Management of patients with closing aortic dissection].

Acute aortic dissection is a catastrophic event requiring immediate diagnosis and definitive treatment, while the clinical characteristics of closing aortic dissection are not well known. From Jan. 1991 through Dec. 1994 a total of 24 patients with closing aortic dissection (CAD) was managed at our institution. There were 19 men and 5 women, ranging in age from 49 to 74 years with a mean of 65 years. All patients presented with a sudden onset of severe chest and back pain. Twenty patients had a history of hypertension with a wide mediastinal silhouette on chest X-ray. The diagnosis of CAD was established by contrast computed tomographic (CT) scans in all patients with no evidence of patent false lumen. The descending thoracic aorta was involved in 17 patients and the ascending in 5. Conservative medical management was initially attempted for all. Seven patients (Stanford type A/B: 2/5) ultimately required surgical intervention, and 2 patients died. The follow-up was 100% complete with a mean term of 14.6 months. The overall survival rate was 74% at 3 years after the initial presentation. Based on our clinical experience, all patients with CAD need careful antihypertensive therapy and frequent follow-up studies to assess the aorta.

Aged↗
PubMed1995

[Ventricular septal defect with severe pulmonary hypertension: the role of open biopsy in determination of operative indication: a case report].

A 51-year-old man having ventricular septal defect with severe pulmonary hypertension is reported. Operative indication that is denied was finally decided by open lung biopsy. He had pulmonary arterial pressure of 120/42 (70) mmHg. The ratio of pulmonary to systemic systolic pressure was 0.91, the ratio Of pulmonary to systemic flow was 1.26, the ratio of pulmonary to systemic vascular resistance was 0.34, and pulmonary vascular resistance was 14.2 unit x m2. For the reason of difficulty, in determination of operative indication through hemodynamic study, he received open lung biopsy. Histological assessment from biopsy specimen revealed severe occlusive pulmonary vascular disease exhibiting grade IV on the Heath Edwards classification. Open lung biopsy occasionally be selected in case with difficult determination of operative indication in severe pulmonary hypertension is a useful tool.

Biopsy↗
PubMed1994

Impalement injury of the thorax: report of a case.

We report herein the case of a 33-year-old man who survived an impalement injury of the thorax involving the heart, esophagus, and spinal cord. The patient was transported to our hospital with the impalement object left in situ and it was extracted under cardiopulmonary bypass in an operating room. The important principles of surgical management contributing to the successful outcome of such patients are discussed following the presentation of this case.

Adult↗
PubMed1994

A review of 103 cases with elective repair for abdominal aortic aneurysm: an analysis of the risk factors based on postoperative complications and long-term follow-up.

From 1982 through 1992, 103 patients (mean age: 69 years) underwent an elective repair of an abdominal aortic aneurysm (AAA) at our institution. One or more postoperative complications occurred in 30 patients (29%), with a mortality rate of 1.9%. Factors which were found to be significantly associated with postoperative complications based on an univariate analysis included male sex (P = 0.0082), operation time (P = 0.0006), the size of the aneurysm (P = 0.0045), the amount of blood loss during operation (P = 0.0037), poor lung function (P = 0.0155), and the platelet count (P = 0.0468). A simple linear regression analysis showed that there were significant correlations among the AAA size, the duration of operation and the amount of blood loss. The age at operation, however, did not influence morbidity or mortality. Complete survival information was obtained in 96 (95%) patients, while the influence of preoperative risk factors on late survival was also examined by the Kaplan-Meier method. The factors influencing long-term survival were determined to be renal dysfunction and age at the time of operation.

Adult↗
PubMed1994

The surgical treatment of 30 patients with cardiac myxomas: a comparison of clinical features according to morphological classification.

Thirty patients with cardiac myxomas whose main clinical symptoms included congestive heart failure, tachyarrhythmia, chest pain and emboli, were successfully treated with surgery. The cardiac myxomas were found in the left atrium in 23 patients, the right atrium in 6, and the right ventricle in 1. Complete follow-up was conducted from 1 month to 15 years (mean 5.4 years) on 28 patients, 24 of whom were in New York Heart Association (NYHA) Class I, and 2 of whom were in NYHA Class II. The actuarial survival rate was 89% 15 years after surgery and no recurrent myxomas have been identified clinically or by echocardiography in any of the patients. Thus, an aggressive surgical approach is recommended prior to the development of heart failure or other complications whenever cardiac tumors are detected.

Adult↗
PubMed1994

Substrate specificity of Streptomyces beta-xylanase toward glucoxylan.

To discover the specificity of Streptomyces beta-xylanase toward xylan having glucose stubs, glucoxylan was prepared by the hydrogenation of cotton-seed cake glucuronoxylan. The glucoxylan was hydrolyzed by the beta-xylanase of Streptomyces olivaceoviridis E-86, and three kinds of glucoxylo-oligosaccharides were isolated from the hydrolysate by chromatographies on a charcoal column, preparative paper partition, and a Toyopearl HW-40F column. The isolated oligosaccharides had the structures of 2(3)-alpha-glucopyranosylxylotriose, 2(3)-alpha-(4-O-methyl-glucopyranosyl)xylotriose and 2(4)-alpha-glucopyranosylxylotetraose. From the structure of the above oligosaccharides and the results of our previous studies, we suggest that the specificity of Streptomyces beta-xylanase toward glucose stubs is the same as that toward glucuronic acid stubs, but differs considerably from that toward arabinose stubs.

Carbohydrate Conformation↗
PubMed1994

Magnetic resonance imaging of young and aged rat brains under a magnetic field of 7.05 T.

Using a homemade MR imaging probe (Helmoholtz coil), MR images of brains of 5-week-old and 23- or 24-month-old Wistar rats were taken under a magnetic field of 7.05 T (Tesla). The probe was designed to fit the rat head and made by winding thin copper film round an acrylic tube with a 5-cm i.d., 10-cm length and 2-mm thickness. This was adjusted to resonate with the 300 MHz radiofrequency corresponding to the resonance frequency of 1H under a magnetic field of 7.05 T. MR images were obtained by T1-weighted and two-dimensional Fourier transformation techniques. The sagittal and coronal sections were imaged in 1-mm-thick slices. The size of the data matrix was 128 phase-encoded steps. Each image was obtained through eight acquisitions. A comparison of the MR images with those semi-microscopically taken at the same position of the coronal section revealed that the cerebral cortex, hippocampus, hypothalamus and thalamus were clearly imaged by this probe. With aging, MR images of cerebral cortices were observed with decreased signal intensities. Enlargement of the third ventricles and hypertrophy of cranical parietal bones were also recognized in sagittal MR images of aged rats. These observations were more marked in males than in females. From these observations it was concluded that this probe was applicable for MR imaging of rat brains under a magnetic field of 7.05 T.

Aging↗
PubMed1994

Anticoagulant effects of warfarin and kinetics of K vitamins in blood and feces.

Patients (40 cases) were treated with daily dosage of warfarin of 2-7 mg after being undergone artificial valve replacements. Twenty one days after administration of warfarin, we examined the patients for kinetics of K vitamins and vitamin K-dependent coagulation factors in blood, and intestinal flora in feces, as well as the relationship between K vitamins and coagulation activity. The following results were obtained. (1) In warfarin-administered patients (Group B), blood levels of vitamin K1 and menaquinone-7, a vitamin K2 homologue, were similar to those in non-warfarin-administered patients. Therefore, administration of warfarin did not significantly decreased the levels. (2) In patients selected randomly from Group B (Group C), the vitamin K1 level in feces was higher than that in non-warfarin-administered patients. The menaquinone-7 level in feces was similar to that in non-warfarin-administered patients. For the total counts of bacteria and the detection rate of vitamin K2-producing bacteria, there was no significant difference between Group C and non-warfarin-administered patients. (3) The above mentioned results of (1) and (2) suggest that it is important for development of anticoagulant effects by warfarin to inhibit conversion from vitamin K1 to reduced vitamin K1, as well as to inhibit the reducing process from vitamin K1-epoxide to vitamin K1. (4) Vitamin K1-epoxide, a metabolite of vitamin K1, appeared in blood after administration of warfarin; there was a lower correlation between the blood level of vitamin K1-epoxide and the warfarin dosage. Further, PIVKA-II appeared in blood after administration of warfarin; there was a inverse lower correlation between the level of PIVKA-II and HPT, and between PIVIKA-II and TT. In conclusion, it has been clarified that vitamin K1-epoxide and PIVKA-II are useful parameters to evaluate anticoagulant effect of warfarin.

Adult↗
PubMed1994

[A case of pseudoxanthoma elasticum underwent coronary artery bypass grafting].

A case of pseudoxanthoma elasticum (PXE) underwent coronary artery grafting is reported. Coronary angiography of a woman with age of 41 with PXE revealed three vessels lesions. Coronary artery bypass grafting using saphenous vein grafts was performed. The left internal mammary artery was not able to use because of obstruction. Her postoperative course is uneventful for 3 years to date. Histological examination of a segment of ascending aorta revealed changes of PXE underwent CABG is extremely rare. This is the third reported case in Japan.

Adult↗
PubMed1994

[A successful case of two-staged operation for Stanford type B acute dissecting aneurysm complicated with total occlusion of the distal abdominal aorta].

A successful case of two-staged operation for Stanford type B acute dissecting aneurysm complicated with total occlusion of the distal abdominal aorta was reported. A 62-year-old male patient with a long history of systemic hypertension developed acute severe chest, back and bilateral legs pain. An enhanced CT demonstrated Stanford type B dissecting aneurysm with occlusion of the left renal artery and bilateral common iliac arteries. On the day of admission, an emergent right axillo-femoral bypass operation using 8 mm ringed EPTFE graft was undertaken to rescue the ischemic legs. The patient's postoperative course was complicated with acute renal failure and paralytic ileus, which were treated with medical treatment. Four months later, the second operation was done for the localized residual dissecting aneurysm in the proximal descending thoracic aorta. The aneurysm was excised, and the entry was closed with Dacron patch using the previously placed axillo-femoral bypass as a technique for preventing distal ischemia. He was recovered uneventfully and was discharged in a good condition.

Acute Disease↗
PubMed1994

[Surgical treatment of infective endocarditis--an analysis of the risk factors for operative mortality and long-term follow-up].

From September, 1978, through January, 1993, 67 patients (mean age: 44 years) underwent surgical treatment for infective endocarditis (IE) at Kagoshima University. Of 67 patients, 36 showed active endocarditis and 31 healed endocarditis at the time of operation. The over-all hospital mortality was 22.4% (15/67). Risk factors associated with operative mortality by univariate analysis included increased blood urea concentration (BUN), increased cardiothoratic ratio, higher New York Heart Association functional class, infection status (active/healed), aortic valve infection, prolonged aortic cross-clamp time, annular abscess, and calendar year. The patients were operated earlier in the latter part of this series (1988-1993. Multiple logistic regression analysis demonstrated three factors to be statistically significant: BUN, operative year, and aortic valve infection. Complete survival information was obtained in all 52 discharged patients with a mean follow-up time of 4.8 years. There were 5 late deaths including 3 patients with valve related complication. The actuarial survival rate at 10 years after operation excluding hospital mortality was 89%, 92% for active infection 88% for healed infection. The actuarial freedom from valve related complication was 86% at 10 years. The degree of activity of the infection is not a risk factor for operative mortality by multiple logistic regression analysis. We conclude that surgical intervention should be undertaken without delay in the patients with IE before development of hemodynamic deterioration causing renal dysfunction and hypercatabolism.

Adolescent↗
PubMed1994

[Simultaneous operation for thoracic and abdominal lesions].

Successful simultaneous operation for thoracic and abdominal lesions was performed in three cases. A 70-year-old man with bronchogenic cyst and a 73-year-old woman with thymoma, who had also cholecystolithiasis respectively, underwent a cholecystectomy following resection of the intrathoracic tumors. A 69-year-old man with bronchogenic carcinoma and abdominal aortic aneurysm underwent a left upper lobectomy following aneurysmectomy and grafting using vascular prosthesis. Their postoperative courses were uneventful. One stage operation has the advantage of treating both lesions simultaneously and saving the patient from the physical and psychosomatic pain and the risk of a second procedure. If patients are properly selected, simultaneous operation for thoracic and abdominal lesions can be safely performed with a short hospitalization and less expense.

Aged↗
PubMed1994

[Pulmonary sequestration diagnosed by combined computed tomography without contrast enhancement and magnetic resonance imaging: a case report].

A 71-year-old woman with pulmonary sequestration had iodine hypersensitivity. Diagnosis was made using computed tomography without contrast enhancement and magnetic resonance imaging. An anomalous artery arising from the descending thoracic aorta was clearly defined. Thus the diagnosis of pulmonary sequestration was confirmed before successful operation without angiography. This diagnostic procedure is safe, noninvasive and useful to detect the anomalous artery, especially in the patient with iodine hypersensitivity.

Aged↗
PubMed1994

[Multi-organ ischemia due to traumatic lesion of the descending thoracic aorta--a case-report].

This is a case of severe ischemic and reperfusion multi-organ failure due to descending thoracic aortic rupture. A 25 year-old man received a hard blow on his chest in a traffic accident. Chest X-ray, CT scans and aortogram elucidated descending thoracic aortic rupture. Emergency operation was performed 18 hours after the injury. The aortic rupture, 4/5 of the aortic circumference with intact adventitia was seen. The descending aorta 22 distal to the left subclavian artery was repaired under cardio-pulmonary bypass with selective cerebral perfusion. Ischemia due to aortic occlusion with thrombus and reperfusion injury after reconstruction of the aorta connected with rhabdmyolysis and severe multi-organ failure. Intestinal necrosis required laparotomy on the 9th and 15th post operative day. The patient died on 15th postoperative day of multi-organ failure.

Accidents, Traffic↗