Biomedical subjects

T Sasajima

Publications and source records attributed to T Sasajima.

At least 91 records · Page 5Linked to original sources

PubMed1995

[Emergency CABG and mitral valve replacement for anterolateral papillary muscle rupture after acute myocardial infarction].

A 74-year-old man developed sudden cardiogenic shock 5 days after the onset of acute myocardial infarction. Echocardiographic diagnosis was severe mitral regurgitation due to papillary muscle rupture. Despite the effort to support the hemodynamics with catecholamines and IABP, the patient's condition deteriorated rapidly, which necessitated emergency operation. Anterolateral papillary muscle was found to be totally ruptured. Coronary artery revascularization and mitral valve replacement were performed. Postoperative course was uneventful, with two days of IABP and three days of ventilatory support. The patient could start rehabilitation program on the 7th postoperative day. He was discharged in 2 months in NYHA class I. Reports of successful emergency operation for total papillary muscle rupture following acute myocardial infarction are rare. Involvement of anterolateral papillary muscle is rarer. Early diagnosis and surgical treatment are mandatory to save this group of patients.

Aged↗

PubMed1995

[Kinetics of glucose metabolism in central neurocytomas].

To estimate proliferating activity of central neurocytoma, we measured kinetic rate constants and glucose metabolic rate (kinetic-rCMRGI) using dynamic positron emission tomography (PET), as well as autoradiographic rCMRG1 (arg-rCMRG1), in patients with histologically verified central neurocytoma. The subject included five patients, four males and one female, aged from 23 to 53 years with a mean age of 41 years old. All tumors were located in the lateral ventricle and two extended into the third ventricle through the forearm of Monro. Tumor lesion on the PET images was determined using CT or MRI, which was performed at levels equivalent to those for the PET scans. The kinetic rate constants of tracer transport from blood to brain (k1), reverse transport from brain to blood (k2), and phosphorylation (k3) were analyzed according to the three compartment 18F-fluorodeoxyglucose (FDG) model. For quantitative analysis, regions of interest (ROI) on PET images were delineated on the tumor and the contralateral gray matter. Tumor k1 and k2 values were similar to or higher than those of the contralateral gray matter, suggesting high permeability due to lack of blood-brain barrier. Tumor k3 value, an indicator of hexokinase activity, and kinetic-rCMRG1 were exceedingly lower in three of five patients. These three patients have been free from tumor recurrence or regrowth, postoperatively. The other two patients, tumor kinetic-rCMRG1 was similar to or higher than that of the contralateral gray matter. One patient suffered from tumor regrowth shortly after resection, and the other has been followed up postoperatively. Thus, k3 and kinetic-rCMRG1 are indicative parameters of proliferative activity in central neurocytoma.

Adult↗

PubMed1995

[Kinetic analysis of glucose metabolism in meningiomas--comparison with malignant gliomas].

We measured kinetic rate constants and glucose metabolic rate (kinetic-rCMRGl) using dynamic positron emission tomography (PET), as well as regional cerebral blood flow (rCBF), blood volume (rCBV), oxygen extraction fraction (rOEF), oxygen metabolic rate (rCMRO2) and autoradiographic rCMRGl (arg-rCMRGl), in patients with meningioma. Ten patients including one recurrent case, two males and eight females aged from 44 to 71 years with a mean age of 54 years old, were studied prior to surgical interventions. Histological diagnosis was as follows: seven cases of meningothelial type, two cases of angiomatous type and one fibrous type. For quantitative analysis, regions of interest (ROI) on PET images were delineated on the tumor and the contralateral gray matter in comparison with eight cases with malignant gliomas (five cases of malignant astrocytoma and three cases of glioblastoma, aged from 14 to 70 years with a mean age of 41 years old). Hemocirculation of the tumor was exceedingly higher than that of the contralateral gray matter, which corresponded to neuroradiological findings of abundant tumor vessels. Low rOEF implicated an excessive blood flow beyond oxygen demand of the tumor. The raised metabolic rate (rCMRO2/rCMRGl) suggested rather aerobic glycolysis as compared with malignant gliomas. The kinetic rate constants of tracer transport from blood to brain (k1), reverse transport from brain to blood (k2), and phosphorylation (k3) were analyzed according to the three compartment model of 18F-fluorodeoxyglucose (FDG). Tumor k1 and k2 values markedly increased in all examined cases, suggesting high permeability due to lack of blood-brain barrier and an abundant blood supply.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[Positron emission tomographic findings of subependymal giant cell astrocytoma developed in tuberous sclerosis--a case report].

Tuberous sclerosis (TS) is well known to be occasionally associated with subependymal giant cell astrocytoma (SGCA). SGCA is considered to be a benign tumor in its clinical course and morphology. However, this tumor is grown sometimes so rapid and caused hydrocephalus. To our knowledge, little is known about hemocirculation and metabolism, particularly in relation with proliferating activity of TS and SGCA. We measured hemocirculation and metabolism of SGCA developed in a case of TS using positron emission tomography (PET). A 13-year-old-boy who had frequently developed convulsions four months after birth. He was diagnosed as TS and had been medically treated with anticonvulsants, since multiple intraventricular calcifications were detected by CT, at the age of five months. The convulsions had been well controlled. In March 1993, he presented with syncopal attack and admitted to our hospital. CT showed multiple subependymal nodules. Among the nodules, one of the left anterior horn exceeded 2cm in size obliterated Monro's foramen. The tumor was homogeneously enhanced with contrast medium. The lesion detected by postcontrast T1-weighted MR imaging had almost the same status as that by CT. T2-weighted image revealed cortical tubers as high intensity area at the left frontal and parietooccipital regions. PET was performed with the Headtome IV. Hemocirculation of the tumor was lower than that of contralateral gray matter, which suggested poor blood supply. The oxygen and glucose metabolism of the tumor were decreased compared with contralateral gray matter, indicative of a low activity of proliferation and a clinically benign tumor in the present case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[Experimental evaluation of a new gelatin-impregnated woven Dacron vascular prosthesis (CL301)].

We investigated the biological response and biodegradation of CL301, a presealed woven Dacron prosthesis (UBE woven) with glutaraldehyde stabilized gelatin. The sealant does not affect its handling characteristics because of the glycerin treatment. The total content of endotoxin in the CL301 was 5.3 +/- 0.5 pg/mg of sealant material (1.7 +/- 0.2 pg/cm2), which was 1/5 and 1/6 of that found in Hemashield and Gelseal, respectively. The pyrogen test was negative and the content was estimated below the minimum pyrogenic doses for thoracic aortic surgery. Five cm-long grafts with a diameter of 10 mm were implanted into the descending thoracic aorta of dogs weighing 10-16 kg. These grafts were retrieved 2 hours, 7, 10 days, 5, 8 and 10 weeks after implantation. Thrombus-free surfaces were 28%, 77%, at 5 and 10 weeks and there was no excessive inflammatory response to the sealant. The total, and the effective sealant remaining were 80.6%, 56.5% at 5 weeks, 60.8%, 38.3% at 10 weeks, respectively. The sealant was removed more rapidly from the inner surface than from the outer. In half of the graft area, the sealant was removed or detached from the Dacron surface 5 weeks after implantation, indicating that delayed resorption of the sealant substantially did not affect the healing process. We conclude that because of the harmless amount of endotoxin and effective sealing for 5 weeks, followed by an acceptable healing process experimentally, CL301 is the presealed Dacron graft of choice for thoracic aortic surgery.

Animals↗

PubMed1995

[Malignant mediastinal lesions with invasion to the superior vena cava].

Four patients underwent resection of mediastinal malignant tumors with invasion to the superior vena cava. Two patients had invasive thymoma, one seminoma, and one metastatic mediastinal lymph nodes of unknown origin. Prior to resection of the tumor, an ePTFE graft was anastomosed between the innominate vein and the right atrium to maintain the venous drainage from the brain and the upper extremities. In two patients, the superior vena cava was reconstructed by patch angioplasty after the tumor with a part of the vena cava was safely resected. One patient died of acute respiratory failure, but the other three are alive and well without any evidence of graft obstruction. This safe and useful method in order to prevent cerebral congestion during and after resection of the tumor.

Adult↗

PubMed1994

Perfusion and metabolism in predicting the survival of patients with cerebral gliomas.

BACKGROUND: Noninvasive measurements of cerebral circulation and metabolism may be useful for diagnosis in patients with brain tumors. The authors tested the prognostic significance of circulatory and metabolic values or ratios determined by positron emission tomography (PET) in patients with gliomas. METHODS: The subjects were 23 patients, who underwent a complete PET study of cerebral circulation and metabolism with long-term follow-up of at least 57 months. Regional cerebral blood flow (rCBF), blood volume (rCBV), oxygen extraction fraction, and the metabolic rates of oxygen (rCMRO2) and glucose (rCMRGl) were measured before treatment. Data regarding tumors, the contralateral gray matter and white matter, and the ratio between tumor and gray matter or between tumor and white matter were compared with survival time from the time of the PET study. Prognostic factors were tested using Cox's regression analysis. RESULTS: Among clinical parameters, histologic grade and performance status were important variables regulating survival. When survival times of patients with values or ratios equal to or higher than the median were compared to those of patients with values or ratios lower than the median, significant determinant PET measurements were tumor rCMRGl and the ratios of tumor:gray rCMRGl and tumor:white rCMRGl. Median survival time in the patients with an rCMRGl value of 4.4 mg/100ml/minute (median value) or more indicated 9 months, which was significantly shorter than greater than 113 months in the patients with a value lower than the median (P = 0.003 by the generalized Wilcoxon test). Patients with a higher value of gray rCBF, rCBV, or rCMRO2 had significantly longer survival times than those with a lower value. CONCLUSIONS: Cerebral circulation and metabolism as determined by PET can be of ancillary significance in predicting the prognosis of patients with gliomas.

Adolescent↗

PubMed1994

Plantar or dorsalis pedis artery bypass in Buerger's disease.

The peripheral type of Buerger's disease is unresponsive to conservative therapy when accompanied by multisegmental occlusion at the level of the ankle. Between November 1983 and April 1993, we performed 15 bypasses below the ankle for this type of thromboangiitis obliterans in 13 patients (mean age 45.7 years), including four females. Ten patients had intractable toe ulcers with severe pain, and five had foot-threatening ischemia or disabling foot claudication. Eleven patients were heavy smokers, two were passive smokers, and six had a history of sympathectomy. All patients had occlusion of the three main crural arteries or both of the tibial arteries at the ankle. Of the 15 bypasses, 10 were to the medial or lateral plantar arteries, two were to the common plantar artery, and three were to the dorsalis pedis artery. There were three early and three late graft failures. The causes of early graft failure were thrombosis at the site of cross-clamping, anastomosis to a diseased segment, and arterial spasm. The three late failures (> 3 months) were due to disease progression in patients who continued to smoke, whereas all grafts remained patent and functioned well in patients who stopped smoking. Because patients with thromboangiitis obliterans are relatively young and active, early healing of ulcers and restoration of normal limb function are important objectives in their treatment. Bypass to the foot arteries can provide an excellent outcome, although special techniques and postoperative cessation of smoking are essential for success.

Adult↗

PubMed1994

[Congenital coronary arterial fistula drained to the coronary sinus--a case report].

We report a very rare case of an infant with coronary arterial fistula in whom the communication between a dilated right coronary artery and the coronary sinus was found. The patient was 1-year-old. She had pulmonary congestion and cardiomegaly due to the left-to-right shunt through the fistula, and underwent ligations of the fistula. Ligations of the fistula was indicated because the patient was too small to undergo a fistula resection and coronary arterial bypass grafting. Although the patient had a successful post-operative course, we are paying attention to the aneurysmal change of the dilated right coronary artery proximal to the site of ligations.

Arteriovenous Fistula↗

PubMed1994

[Longitudinal analysis of glucose metabolism in recurrent meningioma].

We repeatedly measured kinetic rate constants and glucose metabolic rate (kinetic rCMRG1) using dynamic positron emission tomography (PET) and autoradiographic rCMRG1 in a patient with recurrent meningioma. A 50-year-old woman who presented with a left visual disturbance was admitted to our hospital. MR images revealed a mass lesion occupying the left middle fossa. The patient underwent Simpson grade IV surgery. The histological diagnosis was meningothelial meningioma. One year later the tumor had grown back to almost the same size as before treatment and was removed again by Simpson grade IV procedure. Postoperatively, the patient underwent radiation therapy (54 Gy). Two years after the second operation, the tumor was found to have invaded the left orbit and was resected by Simpson grade IV procedure. After additional radiation therapy, the patient was discharged. The rate constants were analyzed preoperatively and whenever the tumor recurred according to the three compartment 18F-fluorodeoxyglucose (FDG) model. Preoperative PET indicated tumor k1 and k2 values higher than in the contralateral gray matter, suggesting high permeability due to absence of the blood-tumor barrier and an abundant blood supply. The tumor k3 value, an indicator of hexokinase activity, was as high as in the contralateral gray matter. When the tumor recurred, the tumor k1, k2 and k3 values remained consistently high, indicating high proliferative activity. In contrast, the contralateral gray matter k1, k2 and k3 values decreased to some extent, suggesting effects of surgery or radiotherapy. Tumor rCMRG1 values, both autoradiographic and kinetic, were enhanced markedly.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗

PubMed1994

[Recent advances and problems in peripheral arterial reconstruction].

Recent advances in the field of peripheral arterial reconstruction have been remarkable. These advances are mainly derived from the development of diagnostic technology such as Doppler ultrasound analysis, further refinement of surgical technique including surgical instruments and materials, and naturally improvement of patient care in the pre-, peri- and postoperative period. During the past 14 years we have performed peripheral arterial reconstruction in 1,200 cases (1,660 limbs) mainly with occlusive lesion due to arteriosclerosis obliterans. In our hand, aorto-iliac occlusive lesion has been routinely bypassed with Dacron prostheses and the secondary patency rate at eleven years reached 96.5%. The main problems encountered in this region were anastomotic aneurysm in the femoral artery (3.9%) and graft infection (1.2%). In the infrainguinal region there are still problems to be solved, although the primary (secondary) 5 year patency rates of reversed vein graft as well as in situ vein graft including femoro-popliteal below knee and femoro-crural bypasses have exceeded 70% (85%). First, there is no graft material comparable to the autogenous vein (AVG). Secondly, many of the AVG should suffer occlusive pathological changes from the environment in the long term following surgery. At the present time, we have no effective method to solve these problems, therefore we should follow up the patients heedfully to maintain the graft patency as well as to improve their quality of life and prognosis.

Anastomosis, Surgical↗

PubMed1994

[A case report of innominate and carotid artery aneurysms causing cerebral embolism].

Brachiocephalic aneurysms are relatively rare in Japan. A case with tandem aneurysms of innominate and right carotid artery was experienced and its successful surgical treatment was reported. A 54-year-old female patient had an attack of cerebral infarction with left hemiparesis. Computed tomography and angiogram revealed aneurysms of innominate and right carotid artery causing cerebral embolisms. Aneurysmectomy and replacement with Dacron prosthesis was performed. A temporary shunt was utilized between ascending aorta and common carotid artery during clamping carotid artery. She had no problems after operation, and her postoperative course was uneventful.

Anastomosis, Surgical↗

PubMed1993

(14C-methyl)-L-methionine uptake in rat brain tumors before and after treatment with the protein synthesis inhibitor cycloheximide.

Autoradiographic study of (14C-methyl)-L-methionine with brain tumor bearing rats aimed at an elucidation of the mechanism of tracer accumulation in the protein synthesis of tumor. Twice as much tracer accumulated in the tumors compared as in the contralateral gray matter (nontumor region) at 90 min post intravenous injection. The protein-bound fraction of the tumors, expressed as acid-insoluble fraction (AIF), was 1.7 +/- 0.6 (mean +/- standard deviation, n = 6), significantly higher than that (0.8 +/- 0.2) of the nontumor region (p < 0.05 by the Mann-Whitney test). The tumor AIF comprised 82.3 +/- 9.2% of the total amount of the tracers accumulated in the tumors. The protein synthesis inhibitor cycloheximide reduced the tracer uptake and the AIF of the tumors to an almost same level as the nontumor region. These findings indicate that metabolic acceleration of protein synthesis may be a main reason for the high accumulation of (14C-methyl)-L-methionine in tumor.

Animals↗

PubMed1993

Primary central nervous system involvement of the so called 'peripheral T-cell lymphoma'. Report of a case and review of the literature.

Primary central nervous system (CNS) involvement of non-Hodgkin's lymphoma is uncommon and a vast majority of reported cases are of B-cell origin. We present a 52-year-old woman with primary peripheral T-cell lymphoma of the brain. Immunostaining of paraffin-embedded sections proved tumor cells to be positive for T-cell markers MT1 and UCHL1, and negative for B-cell markers MB1, and 4KB5. Radiotherapy combined with steroid therapy rendered neurologic recovery and complete tumor remission confirmed by computed tomography and magnetic resonance imaging. From a review of documented 19 cases of primary CNS T-cell lymphoma including the present case, this disease is characterized by poor prognosis among CNS lymphomas.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Case report: radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma.

A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. Cerebral angiography revealed diffuse stenosis at both carotid bifurcations and at the origins of the right posterior communicating and posterior cerebral arteries. Haemodynamic and metabolic depression therefore implicated radiation-induced vasculopathy in the present case.

Astrocytoma↗

PubMed1993

Comparison of reversed and in situ saphenous vein grafts for infragenicular bypass: experience of two surgeons.

A series of 241 consecutive autogenous vein bypasses for chronic lower-limb ischaemia performed by two surgeons since 1980 was reviewed. After 1985, in situ vein bypass was employed preferentially and was compared with reversed vein bypass. The two groups of patients had similar risk factors, indications and outflow. Of the 241 bypasses, 157 were to the below-knee popliteal artery and 84 to infrapopliteal arteries. The utilization rates of a single ipsilateral saphenous vein were 57.5% for reversed and 71.9% for in situ vein bypass. However, in situ vein bypass was impossible in 43 procedures and these were changed to the reversed operation with contralateral vein. The primary 5-year patency rates of reversed and in situ vein bypass grafts to the popliteal artery were 82.5 versus 74.5%, and the primary 4-year patency rates for infrapopliteal bypass 68.5 versus 80.0%. The respective secondary patency rates were 94.2 versus 92.1% and 85.7 versus 91.1%. The main cause of graft failure was vein graft stenosis (reversed vein bypass, 13.0%; in situ, 11.1%), which usually occurred in the first 2 years after surgery. Of 23 grafts revised for stenosis, 21 were salvaged and restenosis rarely occurred. Both reversed and in situ vein bypass grafts were equally effective, but careful surveillance for 2 years and aggressive revision were extremely important after either type of reconstruction.

Adult↗

PubMed1993

Autoradiographic analysis of (14C-methyl)-L-methionine uptake in transplanted rat brain tumors.

To elucidate metabolic pathways of methionine in brain tumors, we studied autoradiographic images of (14C-methyl)-L-methionine (14C-Met) in transplanted rat brain tumors. 14C-Met accumulated in the tumor almost twice as much as in the gray matter 90 min after injection. The acid-insoluble fraction, which was bound to macromolecules, comprised 84% the total count of the accumulated tracers in the tumor. Analysis of 14C-Met tracer accumulation is informative for understanding amino acid metabolism in brain tumors.

Animals↗

PubMed1993

[Chemo-endocrine therapy with high dose medroxyprogesterone acetate for recurrent or advanced breast cancer].

The endocrine therapy with high-dose medroxyprogesterone acetate (MPA) was applied for 19 patients with recurrent breast cancer and 3 with advanced breast cancer. According to the dominant lesion of the disease, the patients were divided into three groups; 13 with soft tissue lesion, 5 with visceral lesion, and 4 with osseous lesion. The serum MPA level was higher than 25 ng/ml in 14 cases out of 19 examined. The results of objective responses in second-line therapy with MPA were CR in two cases, and NC or PD in 20 cases. In 19 out of 22 patients with MPA therapy, the periods of survival were longer than the period of 50% survival of the patients without MPA therapy.

Adult↗