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M Tadokoro

Publications and source records attributed to M Tadokoro.

At least 37 records · Page 2Linked to original sources
PubMed1999

Parieto-occipital glucose hypometabolism in Parkinson's disease with autonomic failure.

To investigate the characteristics of regional cerebral metabolism in a subgroup of patients with Parkinson's disease and autonomic failure, we studied seven patients with Parkinson's disease with autonomic failure (PA group), 11 patients with Parkinson's disease without apparent autonomic failure (PD group), and nine normal controls using fluoro-deoxyglucose positron emission tomography (FDG-PET). To determine differences in metabolic distribution among these groups, regional relative glucose metabolic rates (RGMR), which were normalized with cerebellar values, were calculated and age-adjusted covariance analyses were done. When compared with that of controls. RGMR in the cerebral cortex of the PA group was markedly reduced in the occipital cortex (P<0.001), inferior parietal cortex (P<0.005) and superior parietal cortex (P<0.005), but without a decrease in the sensory motor and medial temporal cortices, putamen and thalamus. In contrast, the PD group did not show significant focal hypometabolic distribution. Our findings raise the possibility that Parkinson's disease with autonomic failure may overlap with the features of dementia with Lewy bodies.

Aged↗
PubMed1998

Interobserver agreement in sonographic diagnosis of breast tumors.

OBJECTIVE: To evaluate interobserver agreement in the interpretation of breast ultrasonography. METHODS: 55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' final impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (kappa) values were employed. RESULTS: The kappa values of shape and posterior echoes were significantly higher than those of the other four criteria (P<0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher kappa values compared with more ambiguous cases (P<0.05). CONCLUSION: Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.

Breast Diseases↗
PubMed1998

Neural activation of the brain with hemodynamic insufficiency.

Little is known about how ischemia affects hemodynamic responses to neural activation in the brain. We compare the effects of a motor activation task and a cerebral vasodilating agent, acetazolamide (ACZ), on regional cerebral blood flow (rCBF) in primary sensorimotor cortex (PSM) in six patients with major cerebral artery steno-occlusive lesions without paresis of the upper extremities. Quantitative rCBF was measured in all patients using H2(15)O autoradiographic method and positron emission tomography. The CBF was determined at rest, during a bimanual motor activation task, and 10 minutes after ACZ administration. With bimanual motor activation, rCBF increased significantly in both PSM compared with at rest (P < 0.01 on lesion side, and P < 0.02 on contralateral side). However, rCBF did not increase after ACZ injection in the PSM on the lesion side, whereas rCBF increased significantly in the contralateral PSM after ACZ injection compared with the level at rest. This result suggests that despite a decreased hemodynamic reserve, there is a nearly normal flow response to neural activation, indicating that the mechanism of vasodilation responsible for perfusion change is different for acetazolamide and neural activation. The relations among neural activation, hemodynamic status, and cerebral metabolism in the ischemic stroke patients are discussed.

Acetazolamide↗
PubMed1998

[A case of sellar T cell type malignant lymphoma].

A case of primary T cell type malignant lymphoma of the sellar region was reported. This 53-year-old male was admitted to our neurosurgical service because of slowly progressive occipitalgia and diplopia over the previous 5 months. On admission neurological examination revealed a slight limitation of the lateral movement of the left eye. Endocrinological examination showed no abnormalities. Despite a mild neurological deficit, a CT scan revealed an extensive bony destruction around the sellar region including the dorsum sellae, the bilateral petrous apices, and the upper two thirds of the clivus. Magnetic resonance imaging (MRI) disclosed that the tumor was slightly hypointense on T1-weighted image, isointense on T2-weighted image, and faintly and homogeneously enhanced after administration of Gd-DTPA. Since the tumor was enhanced faintly on MRI, it was diagnosed as an invasive pituitary adenoma, but it was thought that chordoma and germinoma should be considered. The patient underwent a transsphenoidal surgery. A firm, grayish and avascular tumor was partially removed. The histopathological examination using monoclonal surface marker of the specimen revealed the tumor was stained with UCHL-1 and CD3 antibodies directed against T cells, and diagnosed as T cell type malignant lymphoma of the sellar region (diffuse, large cell type; LSG). Postoperatively he received radiation therapy. His symptoms much improved and no regrowth of the residual tumor has been found in follow-up studies to the present. Primary malignant lymphomas very rarely occur in the skull base. As far as we are aware, this is the only second case of primary T-cell lymphoma in the sellar region reported so far in the medical literature. Although preoperative diagnosis is extremely difficult because of a paucity of data, malignant lymphomas should be kept in mind in the differential diagnosis of sellar tumors, especially if neuroimaging studies show an extensive bony destruction in the skull base.

Combined Modality Therapy↗
PubMed1997

Effects of delayed treatment with nebracetam on neurotransmitters in brain regions after microsphere embolism in rats.

1. The effects of delayed treatment with nebracetam, a novel nootropic drug, on neurotransmitters of brain regions were examined in rats with microsphere embolism-induced cerebral ischaemia. 2. Cerebral ischaemia was induced by administration of 900 microspheres (48 microns) into the internal carotid artery. The rats with stroke-like symptoms were treated p.o. with 30 mg kg-1 nebracetam twice daily. The levels of acetylcholine, dopamine, noradrenaline, 5-hydroxytryptamine (5-HT) and their metabolites in the cerebral cortex, striatum and hippocampus of animals with microsphere embolism were determined by high performance liquid chromatography (h.p.l.c.) on the 3rd and 7th days after the operation. 3. Although the microsphere embolism induced significant changes in most of the neurotransmitters and some of their metabolites in the brain regions, the delayed treatment with nebracetam partially restored only the hippocampal 5-HT and the striatal dopamine metabolite contents on the 3rd day. 4. The hippocampal in vivo 5-HT synthesis, but not the striatal dopamine synthesis, was attenuated in rats with microsphere embolism on the 3rd day, but was restored by treatment with nebracetam. In vivo striatal dopamine turnover rate of the rats with microsphere embolism was inhibited on the 3rd day irrespective of treatment with nebracetam. 5. The present study provides evidence for a possible action of nebracetam on 5-HT metabolism in the ischaemic brain.

Acetylcholine↗
PubMed1997

Apolipoprotein E in progressive supranuclear palsy in Japan.

Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease which shows several psychiatric and neurologic symptoms: pseudobulbar palsy, supranuclear ocular palsy, extrapyramidal rigidity, gait ataxia, and dementia. Almost all cases seem to be sporadic; therefore, the elucidation of risk factors is important to clarify the pathological mechanism. Apolipoprotein E4 (ApoE4) is now well established as a risk factor of Alzheimer's disease (AD). Here we report the ApoE allele frequency in PSP, which shares pathological findings such as neurofibrillary tangle (NFT) with AD. NFT is an important sign for the derangement of normal cytoskeletons in degenerating neurons. Although there was no significant increase in epsilon 4 allele frequency in the present series of PSP cases compared with that in the Japanese controls, there was a significant increase in the epsilon 2 allele frequency in PSP compared to controls.

Aged↗
PubMed1997

Comparison of vasodilatory effect of carbon dioxide inhalation and intravenous acetazolamide on brain vasculature using positron emission tomography.

Carbon dioxide (CO2) and acetazolamide are increasingly being used as vasodilators to detect cerebrovascular reserve capacity in patients of chronic cerebrovascular disease. The functional cerebrovascular reserve or ability of cerebral vessels to lower their resistance in response to decrease in cerebral perfusion pressure is expressed as change in cerebral blood flow from baseline under a vasodilatory stimuli. Theoretically a vasodilator causing maximum vasodilation, and thereby expressing complete reserve capacity would be more suitable for such a purpose. We quantitatively compared the vasodilating effect of 5% CO2 inhalation and 1 g of intravenous acetazolamide by positron emission tomography. Cerebrovascular reserve was quantified in six patients with chronic cerebrovascular disease in the same sitting, using oxygen-15 labeled water (H2(15)O) positron emission tomography at rest, during 5% CO2 inhalation and after 1 g intravenous acetazolamide. A significant linear correlation in both nonlesion hemisphere (r = 0.701, p < 0.001) and in lesion hemisphere (r = 0.626, p < 0.005) was found between CO2 and acetazolamide for cerebrovascular reserve capacity. This correlation improved by considering cerebrovascular reserve per unit change in arterial carbon dioxide (r = 0.744, p < 0.001 in nonlesion hemisphere and r = 0.721, p < 0.001 in lesion hemisphere). The quantitative value of global reserve capacity was different by CO2 stimuli (5.2%) and acetazolamide (49.7%). Though a similar vasodilatory response is elicited by both vasodilators, acetazolamide seems to be more potent and therefore should be preferred to detect patients with exhausted cerebrovascular reserve capacity.

Acetazolamide↗
PubMed1997

Effects of nebracetam on synaptosomal monoamine uptake of striatal and hippocampal regions in rats.

Effects of nebracetam, a novel nootorpic agent, on the synaptosomal uptake of neurotransmitter monoamines of the brain regions were examined. Striatal and hippocampal synaptosomes were isolated by the Percoll gradient method, and the striatal dopamine uptake and hippocampal serotonin uptake were measured in the presence of different concentrations (1 to 1000 microM) of nebracetam in vitro. A significant reduction in dopamine uptake in the striatum and serotonin uptake in the hippocampus was seen at concentrations of 100 microM or above. In in vivo microdialysis study, there were no appreciable changes in the extracellular concentrations of striatal dopamine and hippocampal serotonin when this agent at a dose of 30 mg/kg, which was effective in improving ischemic brain energy metabolism, was applied i.p. to the rat. The ineffectiveness of nebracetam in the in vivo microdialysis may be due to low levels of the concentration of nebracetam when the agent was administered i.p. at a dose of 30 mg/kg, since the brain blood concentration of this agent is pharmacokinetically estimated to be no more than 15 microM when this dose of nebracetam is employed. Thus, it is unlikely that this agent at a pharmacologically effective dose alters dopamine or serotonin uptake in the brain nerve terminal under normal conditions.

Animals↗
PubMed1997

A case of primary malignant fibrous histiocytoma of the heart with a left-to-right atrial shunt.

A previously healthy 64-year-old woman attended our hospital with chest pain, facial edema, and general fatigue. A chest radiograph revealed cardiomegaly, small bilateral pleural effusions, and hilar congestion--findings that improved after early therapy with furosemide and methyldigoxin. A chest radiograph recorded 7 years earlier had revealed no dilation of cardiac shadow. There were no findings suggesting atrial septal defect (ASD) or valvular heart disease. Echocardiography revealed a tumor-like mass adhering to the posterior wall of the left atrium. Color-flow Doppler echocardiography revealed a left-to-right shunt at the atrial level. The Qp/Qs ratio as measured by cardiac catheterization was 2.0. Coronary angiography revealed abnormal dilated arteries from the atrioventricular nodal branch and several feeding arteries from the left circumflex branch. We hypothesized that the left-to-right shunt could be due to the tumor, which extended to the rim of the patent foramen ovale, or to the very small, previously unrecognized, ASD. This patient died 6 months after her first admission and an autopsy was performed. Light microscopic examination of the tumor revealed spindle-shaped fibroblast-like cells arranged in a storiform or fascicular pattern. The immunohistochemical findings were consistent with malignant fibrous histiocytoma (MFH). In the literature, left-to-right shunt at the atrial level has not been reported in patients with cardiac MFH.

Echocardiography↗
PubMed1997

[A chronic encapsulated expanding hematoma with cyst formation caused by rupture of arteriovenous malformation: a case report].

A 57-year-old male was admitted to our hospital complaining of a headache with disturbance of consciousness on November 7, 1994. CT scans revealed an intracerebral hematoma of 25ml in volume in the left frontal lobe with adjacent spotty calcification. An arteriovenous malformation (AVM) with a nidus of 2.0 x 2.0cm in size was found to be the cause of the hematoma by cerebral angiography. Since the patient complained of mild right hemiparesis 10 days after the onset, CT scans were taken and a slightly enlarged hematoma with capsule formation was observed. On the 31st day after the onset, the hematoma had liquefied and the surrounding capsule was clearly visible on CT. Since the patient's only symptom was a slight headache, and he displayed no other serious conditions, a palliative operation was planned. The AVM was removed and the capsule was resected 41 days after the onset. The capsule or cyst wall of the liquefied hematoma was composed of three layers: a granulation layer with a neovascular system on the inside, a collagenous layer in the middle, and a reactive brain tissue layer on the outside. The structure of the capsule was the same as the structure of the cyst wall in chronic hematomas that have been reported as cystic AVM or encapsulated expanding hematoma in the literature. We would therefore like to propose that chronic encapsulated expanding hematomas form with time due to intermittent bleeding or exudation form the neovascular system of a cyst wall.

Brain Diseases↗
PubMed1997

[18F-fluorodeoxyglucose positron emission tomography in Parkinson's disease].

Positron emission topographic studies on local cerebral glucose metabolism in Parkinson's disease (PD) including our own data were reviewed. In our 18F-FDG PET studies, local or global metabolic change was not found in 9 patients with non-demented PD, with respect to 5 normal controls. Moreover, there was not an apparent difference between severe PD group (Hoehn-Yahr III-IV) and mild PD group (Hoehn-Yahr I-II). In other PD patients with dementia or autonomic failure, parietal dominant hypometabolism was found likely to those of Alzheimer disease, but lenticular nucleus was well preserved. Furthermore 18F-FDG PET findings of atypical parkinsonian syndromes, such as SND and PSP were reviewed. They showed relative hypometabolism in the basal ganglia in PET images. PET study with FDG provides a clue to differential diagnosis of parkinsonian patients.

Brain↗
PubMed1997

[A case of crush syndrome resulting from continuous compression of the upper arm by automatically cycled blood pressure cuff].

We report a case of crush syndrome (rhabdomyolysis) resulting from the prolonged compression of the inadvertently inflated blood pressure cuff around her upper arm. A 61-yr-old woman had undergone total gastrectomy, splenectomy and cholecystectomy for gastric cancer. At the end of the surgery lasting for 5 hrs 40 mins, we found the right upper arm extremely swollen with cyanotic petechiae beyond the inflated cuff. Failure of deflation of the automatically cycled blood pressure cuff was strongly suspected as a cause. She complained numbness and ardor on her hand with motor nerve disturbance and plasma CPK level was elevated. Diuretics were given and fluids were infused vigorously to prevent the renal failure, and continuous cervical epidural block was instituted to increase the blood flow to the injured arm. Prostaglandin E1 and ulinastatin (a protease inhibitor) were also effective for recovery from the crush syndrome. One month later she was discharged home accompanied with a slight numbness on the arm. Attention should be paid to deflation of the automatically cycled blood pressure cuff during anesthesia.

Alprostadil↗
PubMed1997

Analysis of specific accumulation of radiolabeled anti-carcinoembryonic antigen monoclonal antibody CEA 102 in colorectal cancer using computed radiography.

The specific accumulation of radiolabeled anti-carcinoembryonic antigen (CEA) monoclonal antibody (MoAb) CEA 102 in colorectal cancers was investigated by autoradiography of surgical specimens using Fuji Computed Radiography (FCR). Five patients with colorectal cancer were injected intravenously with [13I]-labeled intact CEA 102 or its F(ab')2. Primary tumor and liver metastases were successfully detected by external scanning with gamma camera in four cases. Autoradiographic study using FCR showed predominant localization of [13I]-labeled CEA 102 in primary tumors and liver metastases in all cases. Even the small-sized liver metastasis (0.5 cm) was clearly visualized. The pixel distribution curves showed the heterogeneity of the distribution of administered MoAb in the tumors. In the quantitative distribution analysis of CEA 102, the uptake of the primary tumor was 10-fold greater than that of the normal colon mucosa. These results suggest that MoAb has great potential in radioimmunodetection as well as possible use in antibody-directed therapy.

Antibodies, Monoclonal↗
PubMed1997

[Mitral valve re-replacement in patients aged 70 years and older: is age alone not operative risk factor?].

We analyzed the risk of mitral valve re-replacement (re-MVR) in patients over 70-year-old. Surgical and late follow-up results were compared between 14 elderly patients over 70-year-old (group I) and 23 patients aged from 60 to 69-year-old (group II) who underwent re-MVR due to primary tissue failure (PTF). Donation of autologous blood and a rate of replaced valve prosthesis (mechanical/biological) were different between the two groups. There were no differences in the other factors such as clinical profile, preoperative organ function, operative characteristics, post operative relating factors. No operative death occurred in both groups. There was one hospital death in group I (a hospital mortality rate of 7.1%). The cause of death was related to massive cerebral infarction due to anticoagulant-related thromboembolic event. 4-64 months after re-MVR, the improvement of a NYHA function class was I-II in the two groups. With improvement in myocardial protection and intraoperative strategies, the operative risk in patients undergoing re-MVR over 70-year-old has been markedly reduced. Surgical results in aged patients were satisfactory and age alone is not a contraindication for this operation. The re-MVR in aged patients should be done at the early stage of PTF before progress of cardiac failure.

Age Factors↗
PubMed1997

[Clinical results of single-stage mobilization of pectoral muscle flaps and omental transposition for infected mediastinitis after open heart surgery].

The purpose of this study was to retrospectively evaluate the outcome of refractory infected mediastinitis managed primarily with mobilization of pectoral muscle flaps and omental transposition. From January 1992 to December 1995, infected mediastinitis occurred in 11 (2.5%) of 447 consecutive patients. All patients required sternal debridement. The wound was thoroughly irrigated with a solution of 0.5% povidone-iodine in physiological saline after debridement and then the defect was repaired. Reconstruction of the chest wall was attained using pectoral muscle flaps in seven patients and pectoral muscle flaps and omental transposition in four. Antibiotic therapy was provided for 6 weeks or more according to the regimen in North America. No hospital deaths occurred after surgery. Significant early complications occurred in four patients. The reasons for the prolonged hospitalization were a recurrent wound infection, prosthetic valve endocarditis and saphenous vein graft pseudoaneurysm formation caused by Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Staphylococcus epidermidis (MRSE). Length of stay in ICU after surgical treatment was range 1 to 140 days (an average of 11 +/- 3 days in 9 patients without complications in ICU). Duration between surgical treatment and discharge was range 47 to 300 days (an average of 58 +/- 8 days in 7 patients without significant early complications). At the time of this report, the patients are doing well with no signs of recurrence of infection. The mean follow-up was 28.8 months (range 8 to 48 months). We conclude that single-stage mobilization of pectoral muscle flaps together with omental transposition is very usefull for managing refractory infected mediastinitis. But careful follow-up is needed after this procedure in case of MRSA-caused mediastinitis because of its tendency to recur.

Adult↗
PubMed1997

[A case of systemic lupus erythematosus associated with minimal change nephrotic syndrome].

A case of systemic lupus erythematosus (SLE) associated with minimal change nephrotic syndrome (MCNS) in a 25-year-old female is described. The patient suddenly manifested butterfly rash and proteinuria was first pointed out on March, 1994. On admission, her skin biopsy indicated SLE. Subsequently, she developed nephrotic syndrome. Urinalysis showed heavy proteinuria (4.1 g/day), with no other abnormalities in the urinary sediment. Immunological examination revealed positive antinuclear antibody at a titer of 1:80 with a speckled pattern. Anti-ssDNA and anti-SS-A antibodies were positive, but other antibodies were negative. Serum complement (CH50) was within the normal range (30.5 U/ml). The renal biopsy showed no apparent cellular proliferation or increase of extracellular matrices in glomeruli by light microscopy. Slight deposition of IgG, IgM, C3 and C1q was focally seen in the mesangium and capillary wall by immunofluorescence. Electron microscopic examination revealed small and scattered dense deposits in the mesangium, subepithelium and subendothelium, associated with diffuse fusion of the foot processes of epithelial cells along the glomerular basement membrane. According to the WHO classification, the histological features were compatible with those of lupus nephritis (LN), class Ib. The patient was treated with PREDNISOLONE, Mizorbine and Dilazep, resulting in the disappearance of proteinuria and a normal serum level of total protein. The association of LN and MCNS is very rare. We also investigated the relationship between the intensity of proteinuria and histological types of 53 cases with LN examined in our laboratory. The cases with heavy proteinuria were mostly classified as WHO-Class IV and Class V. We report here a case of LN associated with MCNS and also review the literatures.

Adult↗
PubMed1997

[Coronary artery bypass grafting in a patient with a permanent tracheal stoma].

The performance of open heart surgery in a patient with a tracheostoma can present difficult problems, including mediastinitis and inadequate operative exposure. A 79-year-old man was admitted because of angina pectoris, and had undergone tracheostomy for carcinoma of the larynx 14 years previously. He underwent coronary artery bypass grafting with saphenous vein graft to # 8, 12. A skin incision was made from the angle of Louis to the xiphoid process and carried down through the subcutaneous tissue. The sternum was divided from the xiphoid process to the manubrium and then dislocated from the intact manubrium. Operative time was 165 minutes and arrest time was 64 minutes. Postoperative course was satisfactory and discharged within 24 days after operation. We think that in a case of open heart surgery with a tracheostoma no dissection near a tracheostoma is necessary in order to decrease the risk of postoperative wound infection and mediastinitis.

Aged↗