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Biomedical subjects

M Tadokoro

Publications and source records attributed to M Tadokoro.

At least 19 recordsLinked to original sources

Hemi-parkinsonism in multiple system atrophy: a PET and MRI study.

We selected 6 patients presenting with hemi-parkinsonism from a total of 20 patients with probable multiple system atrophy (MSA) and studied their nigrostriatal lesions using magnetic resonance (MR) imaging and positron emission tomography (PET) with 18F-labeled 2-deoxy-2-fluoro-D-glucose (FDG). T2 weighted MR images demonstrated a decreased signal intensity in the putamen of all patients. This decreased signal was more intense in the nucleus contralateral to the affected body side in 5 patients. A decreased signal in the substantia nigra was found, expanding more on the contralateral side in 3 patients. T1-weighted images showed that the contralateral putamen was smaller in size than the ipsilateral. These findings indicated that the iron deposit and the neuronal cell loss in the degenerative process were more remarkable in the contralateral nuclei. FDG uptake in 5 patients had likewise declined more in the contralateral than in the ipsilateral putamen. The study shows that these patients have the nigrostriatal lesions as described in previous reports on MSA and that an asymmetric lesion relating to clinical signs is present in the nigrostriatal system. When a patient presents with hemi-parkinsonism alone, MR imaging and PET/FDG are useful for the clinical diagnosis of MSA.

Adult

Influence of the electrical stimulation of the hypothalamus on adrenocortical steroidogenesis in hypophysectomized rats.

The electrical stimulation of the ventromedial hypothalamus (VMH), lateral hypothalamic area (LHA), periventricular arcuate nucleus (ARC), and posterior hypothalamus (PHY), on 14C transfer rates from 14C-1-acetate into adrenocortical steroids in adrenal slices of hypophysectomized rats were investigated. The 14C transfer rates into corticosterone and cortisol were increased by the stimulation of the VMH, ARC, and PHY, but decreased by the stimulation of the LHA. From these results, it might be suggested that these hypothalamic structures were involved in the regulation of adrenocortical steroidogenesis without participation of the pituitary.

Acetates

Comparison of Tc-99m HMPAO fast SPECT with Tc-99m HMPAO conventional SPECT in patients with acute stroke.

Tc-99m HMPAO SPECT is more likely to detect a stroke in early stages than CT. However, a conventional HMPAO SPECT study takes at least 30 minutes to complete. This paper compares fast Tc-99m HMPAO SPECT scans and conventional Tc-99m HMPAO SPECT scans with respect to spatial resolution and diagnostic efficacy in vitro and in a small series of patients, respectively. The spatial resolution of fast Tc-99m HMPAO SPECT did not match that of images obtained from conventional SPECT, though the difference proved to be of no clinical significance. Since fast SPECT requires only one-fourth to one-fifth the time necessary for conventional SPECT, it may be more suitable for investigating cases of acute stroke in critical clinical situations.

Acute Disease

Cutaneous leiomyosarcoma.

A child's head-sized tumor on the upper back developed in a 43-year-old man. In spite of an extensive operation for the tumor, he died of multiple metastasis 15 months after the operation. Histologically, tumor cells proliferated throughout the dermal and subcutaneous regions, and a boxed-in appearance was noted with silver staining. Because electron microscopic observations strongly suggested a smooth muscle origin, we diagnosed this case as cutaneous and subcutaneous leiomyosarcoma.

Adult

Autoradiographic analysis of radiolabeled anti-carcinoembryonic antigen monoclonal antibody CEA102 in colorectal cancer using computed radiography.

Anti-carcinoembryonic antigen monoclonal antibody (MAb) CEA102 was produced by immunization with purified CEA and the specific accumulation of radiolabeled CEA102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with 131I-labeled intact CEA102 or its F(ab')2. Primary tumor and liver metastases were successfully detected by external scanning with a gamma camera in 4 cases. Autoradiographic study of the surgical specimens using FCR showed predominant localization of 131I-labeled CEA102 in primary tumors and liver metastases in all cases. Even a small liver metastasis (0.5 cm) was clearly visualized in the autoradiogram by FCR. The pixel distribution curves of the density of the respective tissues in the autoradiograms by FCR showed the heterogeneity of the distribution of administered radiolabeled MAb in individual tumors, but the density of the tumors was higher than that of the normal tissues. In the quantitative distribution analysis of CEA102, the uptake of the primary tumor (mean 1.10%ID/kg) was ten-fold greater than that of the normal colon mucosa (mean 0.10%ID/kg). These results revealed that the application of MAb has great potential in radioimmunodetection as well as in antibody-directed therapy.

Adult

Recurrent rectal cancer and scar: differentiation with PET and MR imaging.

The value of positron emission tomography (PET) and magnetic resonance (MR) imaging in differentiating recurrent rectal cancer and scar was investigated. PET with fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) and MR imaging were performed in 15 patients with suspected recurrence. FDG accumulation in the mass was measured by means of the differential absorption ratio (DAR). All 11 patients with confirmed recurrent rectal cancer had increased accumulation of FDG in the mass (DAR = 4.73 +/- 2.28). Low FDG accumulation in the mass (DAR = 0.97 +/- 0.15) was noted in the remaining four patients, in whom the presence of a scar was proved by means of follow-up observation with or without biopsy. On the MR images, the recurrent tumor could be differentiated from scar in all but one case. The lesion-muscle signal intensity ratios on the T2-weighted images for the recurrent tumor and scar were 2.18 +/- 0.55 and 0.89 +/- 0.30, respectively. PET and MR imaging complement each other in the differential diagnosis between recurrent rectal cancer and scar. PET may also permit the evaluation of the effect of therapy.

Adult

Tumor-specific binding of radiolabeled G-22 monoclonal antibody in glioma patients.

Iodine-131-labeled G-22 monoclonal antibody F(ab')2 fragment reaching specifically with a glioma-associated surface glycoprotein was administered to 12 glioma patients to investigate its use in radioimaging of intracranial gliomas. No immediate or delayed side effects were attributable to antibody injection. Nine patients received the radiolabeled complex intravenously. The images of low-grade gliomas were generally poor and disappeared within 4 days. High-contrast images were obtained beyond the 7th day in high-grade gliomas except one case in the pineal region. Three patients received intraventricular or intratumoral administration. Clear images of all tumors were demonstrated from the 2nd until later than the 7th day. One patient with cerebrospinal fluid (CSF) dissemination of brainstem glioma demonstrated negative CSF cytology after intraventricular administration.

Antibodies, Monoclonal

[Endoscopic closure of the postoperative bronchopleural fistula].

A case of successful endoscopic closure of a bronchopleural fistula with fibrin glue was reported. Fifty-eight-year-old man underwent right lower lobectomy for lung carcinoma. On the 21st postoperative day, he suffered from high fever and diagnosed as right side pyothorax. Then tube thoracotomy was done under UCG-guide. As a fistula in the right lower bronchial stump was found tiny by BFS, we tried to close the fistula bronchoscopically with fibrin glue. The fibrin glue was injected into the fistula via the ERCP tube, which was passed through the bronchoscope. This procedure was performed twice for two weeks interval. The fistula was completely closed about a month after the trial. This method is useful to close postoperative small bronchopleural fistula without surgical intervention.

Bronchial Fistula

[Radioimmunodetection of colorectal cancer, using anti-CEA monoclonal antibody CEA 102: whole IgG versus F(ab')2 fragments].

In order to improve cancer imaging with radiolabeled antibodies, three factors appeared to be of particular importance: (1) The selection of the most favorable monoclonal antibody directed to tumor-associated antigen. (2) The use of F(ab')2 or Fab fragments. (3) Selection of the most convenient isotope. Monoclonal antibody CEA 102 was produced by immunization by purified CEA, and its F(ab')2 fragments were compared with whole IgG as a radiotracer for radioimmunodetection of the colorectal cancer. Fragments were eliminated from the circulation twice as fast as whole IgG, and tumor-to-background ratio was achieved more than 1 at 2-3 days with F(ab')2, but 6-7 days with whole IgG in tumor bearing nude mice. In clinical study, F(ab')2 demonstrated clear image on the 1 at day after injection, whereas achievement of the image was possible on the 3rd day in whole IgG. These results indicated that fragments are preferred over whole IgG. Therefore fragments make it possible to preclude dual isotope subtraction methods, and omit the long delays before imaging. They also make it possible to use short half life radionuclides with excellent photon properties, such as 123I and 99mTc.

Animals

[Arterial embolization therapy for metastatic bone and soft-tissue tumors with microcatheter and microcoils].

Transcatheter arterial embolization therapy was performed in fifteen patients with hypervascular metastatic bone and soft-tissue tumors (7 from renal carcinoma, 5 from hepatocellular carcinoma, and one each from breast, thyroid, and cholangiocarcinoma). Sites of metastasis were spine (7), pelvis (5), skull (2), paraspine (2), chest wall (1), and thigh (1). Five patients had not responded to previous radiation therapy and hyperthermia. Embolization of feeding arteries was performed superselectively with long tapered catheters or coaxial microcatheters. Emulsion of Lipiodol and anticancer agent, polyvinyl alcohol sponge, gelatin sponge, and microcoils were used as embolic materials in various combinations. Relief of pain was experienced in 14 of 15 patients. Two patients were operated following embolization with minimal blood loss. Change in tumor size was evaluated by CT or MRI in ten patients. Reduction of tumor size were more than 50% in five patients, from 25% to 50% in two, and no change in three patients. Especially, patients embolized with microcatheter and microcoils showed excellent long-term results. No serious complications were seen. In conclusion, superselective arterial embolization therapy with coaxial microcatheter and microcoils was proved to be an useful treatment for hypervascular metastatic bone and soft-tissue tumors.

Adult

Myxoid variant of epithelioid leiomyosarcoma of the uterus.

A rare case of myxoid variant of epithelioid leiomyosarcoma of the uterus in a 76-year-old woman is reported. Palpation and computed tomography revealed an enlarged uterus. Total hysterectomy and bilateral salpingo-oophorectomy were performed, and a hemispheric tumor, measuring 2.7 x 2.5 x 1.8 cm, was found protruding into the uterine cavity of the upper uterine segment. The tumor contained a prominent myxoid stroma and epithelioid tumor cells, which were round and polygonal in shape and showed positive immunoreactivity for desmin and vimentin. High mitotic activity was observed in the tumor cells. Electron microscopic examination revealed bundles of filaments in the cytoplasm and fine reticular material in the extracellular matrix. Histochemically, the myxoid stroma contained abundant acid mucopolysaccharide. The tumor cells were considered to originate from smooth muscle cells, while the myxoid stroma expressed varying differentiation of uterine mesenchymal cells. The patient is currently well with no evidence of recurrence or metastasis one year after the operation.

Aged

[A case report of surgical treatment of acute aortic dissection (DeBakey III B) in association with thoracic aortic aneurysm].

This is a case report of 63-year-old man suffering from DeBakey III B acute dissection in association with thoracic aortic aneurysm. He had been following up for hypertension and thoracic aortic aneurysm. He was brought to the hospital by city ambulance complaining of sudden onset of severe back pain. Emergency operation was carried out. It revealed aneurysm of 90 mm in diameter located just distal to the aortic arch and an intimal tear or entry of the dissection located distal to the left subclavian artery. A low porosity Dacron graft was interposed between the distal aortic arch and middle portion of the thoracic descending aorta using inclusion technique. Systemic circulation was bypassing external iliac vein to artery using pump-oxygenator during aortic clamping. His postoperative course was uneventful. In review of the literature, association of the atherosclerotic aneurysm and acute dissection occurred approximately 5% in the cases of aortic dissection with increasing risk of aneurysmal rupture.

Acute Disease

[Surgical repair of postinfarction cardiac rupture in three cases].

Operative managements and results of postinfarction left ventricular (LV) rupture in 2 patients and right atrial (RA) rupture in one patient are reviewed. Two patients showed both subacute onset of LV rupture in association with cardiac tamponade. The site of infarction was inferior wall in one and anterior wall in the other. Both patients underwent infarctectomy with closure of the defect using a Dacron felt patch. Endocardial site of the Dacron patches were covered with own pericardium to avoid bleeding from the patch and postoperative complication of endocardial clot formation. The case with extended inferior wall infarction was succumbed to cardiac failure and acute renal failure at the twelfth postoperative day. The other case was uneventful postoperatively and shows excellent long-term result. Left ventriculography and coronary angiographic studies were carried out 3 months after the surgery. It demonstrated 43% of LVEF. Multiple stenotic lesions were also noted in left coronary artery. The third patient was rupture of the RA in association with cardiac tamponade. Direct suture closure of the rupture was carried out under extracorporeal circulatory support. Patient tolerated the procedure well. Postoperatively, he suffered from exacerbation of renal insufficiency necessitating hemodialysis for a month. He discharged from hospital and now in the good condition. Postoperative RI study and coronary angiography demonstrated no compatible finding of right atrial infarction. However, pathological specimen revealed definite diagnosis of the infarction at the RA appendage.

Aged

[A case report of emergency surgical repair of traumatic transection of thoracic descending aorta].

The injury to the thoracic aorta caused by blunt chest trauma is often fatal. This case is 22-year-old male suffering from transection of the thoracic descending aorta caused by traffic accident. He was transported to our emergency room by an ambulance 15 minutes after the accident. Hundred fifty minutes after arrival to the hospital, we were rush to bring him to the operation theater suspecting serious injury of the thoracic organs in association with left hemothorax. The left standard thoracotomy disclosed the injury of the thoracic descending aorta. Simple cross clamp was applied to the thoracic descending aorta distal to the left subclavian artery for 20 minutes. Completely transected aorta was reapproximated using monofilament 3-0 polypropylene sutures with running manner. He tolerated the procedure well without any complication. His postoperative course was uneventful. He was followed up at the orthopedic department for associated hip fracture thereafter.

Accidents, Traffic

[Supravalvular aortic stenosis syndrome with advanced mitral regurgitation requiring extended aortoplasty and mitral valve replacement: a case report].

This is a case report of a 28-year-old male, suffering from supravalvular aortic stenosis (systolic pressure gradient 60 mmHg) and severe mitral regurgitation associated with elfin face and mental retardation. Severely prolapsed mitral valve with elongated chordae tendineae was replaced with Björk-Shiley mitral valve prosthesis. Simultaneously, extended aortoplasty was carried out using Doty's method. His postoperative course was uneventful. Catheterization study, carried on one month after surgery, revealed complete disappearance of supravalvular aortic stenosis and mitral regurgitation. In review of the literature, as far as we know, report of successful combined correction for supravalvular aortic stenosis and mitral regurgitation is extremely rare.

Adult

[Experimental study on avoidance of surgical heart block in septation for single ventricle].

A new method was developed to prevent surgical injury of the atrioventricular conduction system in septation for single ventricle. The new method includes the use of small Teflon pledgets to cover the conduction system at the crossing sites of suture line, and so that stitches can be placed on the pledgets to skip the conduction system. This paper describes the results of an experimental study to delineate the effects of covering pledgets on the morphology and function of the underlying conduction tissues. Deep hypothermia was employed for this experiment in 15 mongrel dogs. The small Teflon pledgets were sutured to bridge the endocardial surface of the atrioventricular node through the right atriotomy. They were subjected to sacrifice at 1 week to 12 months postoperatively. Electrophysiological study including electrocardiography. His bundle electrography and responsiveness of the atrioventricular conduction to rapid stimulation was done before the sacrifice. The resected heart was embedded in Ceroidin-Paraffin and serially sectioned for pathological study. No noticeable injuries were noted in the underlying conduction system. The electrophysiological study showed normal sinus rhythm at the time of sacrifice. No significant changes were noted in PQ intervals comparing to preoperative state. There were no significant differences in AH intervals, HV intervals and responsiveness to rapid atrial stimulation between experimental and normal control groups. In conclusion, the Teflon felt pledgets were demonstrated to have no detrimental effects on the atrioventricular conduction system in the chronic stage.

Animals