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T Satou

Publications and source records attributed to T Satou.

At least 55 records · Page 3Linked to original sources
PubMed1998

Magnetically induced motor evoked potentials and H-reflex during nembutal and ketamine anesthesia administration in rats.

The effects of nembutal and ketamine anesthesia on motor evoked potentials (MEPs) and spinal segment reflex (H-response, F and M waves) were investigated in rats by magnetic stimulation. These potentials were generated by magnetic stimulation of the motor cortex and the spinal cord (L4-L5). After application of nembutal, MEP and H-response decreased in amplitude, eventually disappearing. The amplitudes of F and M waves increased and persisted at the increased levels during anesthesia. The latencies of F and M waves were constant before and after anesthesia. Following ketamine administration, the threshold, latency and amplitude of the magnetically induced MEPs, and M, F and H responses were not influenced systematically. The results suggested that MEPs and H-response depression and/or disappearance due to synaptic site suppression after nembutal anesthesia, and the increase and persistence of increased F and M waves amplitudes were all due to the increasing motoneuron excitability, whereas ketamine did not affect synaptic sites subjected to magnetic stimulation.

Anesthesia↗
PubMed1997

The progression of beta-amyloid deposition in the frontal cortex of the aged canine.

Brains from 41 aged canines (> or = 10 years of age) were examined immunohistochemically to characterize the laminar distribution and age-related progression of beta-amyloid (A beta) in frontal cortex. We classified the A beta patterns into four distinct types. Type I was characterized by small, faint deposits of A beta in deep cortical layers. Type II consisted of diffuse deposits of A beta mainly in layers V and VI. Type III had both dense plaques in superficial layers, and diffuse deposits in deep layers. Finally, Type IV had solely dense plaques throughout all layers of cortex. We compared the A beta distribution pattern between the Old canines (10-15 years, n = 22) and the Very Old canines (> 15 years, n = 19). The Old group primarily had negative staining, or Type I and Type II patterns of amyloid deposition (73%). Conversely, the Very Old group had predominantly Types II, III and IV deposits (89.5%), a difference that was significant (P < 0.05). We suggest that A beta deposition in canine frontal cortex is a progressive age-related process beginning with diffuse deposits in the deep cortical layers followed by the development of deposits in outer layers. In support of this hypothesis, the deeper layer diffuse plaques in the Very Old group of dogs also contain the largest proportion of beta-amyloid with an isomerized aspartic acid residue at position 7, indicating that these deposits had been present for some time. We also observed fiber-like A beta immunoreactivity within regions of diffuse A beta deposits. These fibers appeared to be degenerating neurites, which were negative for hyperphosphorylated tau. Therefore, these fibers may represent a very early form of neuritic change that precede tau hyperphosphorylation or develop by an alternative pathway.

Aging↗
PubMed1997

Pressure-induced apoptosis in human lymphoblasts.

The viability of human lymphoblasts was investigated after compression at 37 degrees C for 30 min. Immediately after decompression, necrotic cells were observed and the viability decreased sigmoidally to 0 with increasing pressure from 85 to 200 MPa. Apoptotic cells began to be observed from 8 h after decompression in the case of compression at 100 MPa for 30 min at 37 degrees C. The apoptosis was confirmed to be pressure-induced by the Tunel method and by optical and electron microscopy. Cell death by both necrosis and apoptosis due to compression was accelerated in the S phase of the cell cycle.

Apoptosis↗
PubMed1997

Ciliary neurotrophic factor immunoreactivity in rat intramuscular nerve during reinnervation through a silicone tube after severing of the rat sciatic nerve.

The immunoreactivity of ciliary neurotrophic factor (CNTF) and S100 was studied in the degenerating and regenerating intramuscular nerves after the sciatic nerve was severed. The sciatic nerves of male Wistar rats were transected at the midpoint of the thigh, and silicone tubing was used to obtain effective reinnervation. The strong immunoreactivity of CNTF and S100 was observed in the Schwann cell cytoplasm of intramuscular nerves (IMN) and at the neuromuscular junction (NMJ) on the control sections. The CNTF immunoreactivity gradually became weak and indistinct in the Schwann cell cytoplasm after the operation. However, it was recognized again in the IMN at 4 weeks after the operation. On the other hand, the S100 immunoreactivity was continuously observed except at the NMJ through the denervating and reinnervating period. At 12 weeks after the operation, the strong immunoreactivity of both CNTF and S100 was observed again. These findings suggest that the amount of CNTF protein decreased in Schwann cells of the IMN and NMJ during the denervating period and increased during the reinnervating period in proportion to the number of remyelinated Schwann cells after severing of the sciatic nerve. They also suggest that CNTF was more highly correlated than the S100 protein with the reinnervation activity of Schwann cells.

Animals↗
PubMed1997

Early diagnosis of mucosal squamous cell carcinoma of the esophagus: including two interesting cases of superficial spreading-type and multicentric-type squamous cell carcinomas.

We reviewed 10 patients with esophageal mucosal carcinoma in order to improve the early diagnosis of the disease. Histologically seven of the 14 lesions were carcinomas in situ (epithelial cancer), and the other seven lesions were carcinomas confined to the mucosa other than epithelial cancer (muscularis mucosae cancer), all 14 lesions were squamous cell carcinomas (SCC). One of these seven mucosal SCC, which demonstrated an extensive spreading-type SCC in which the size of the SCC was 7 cm long while extending entirely around the esophageal lumen in circumferential spread, is described in detail, and multiple epithelial cancers existed separately in one case. Eleven lesions diagnosed before operation showed abnormal findings on conventional endoscopy regardless of the size and depth of transmural invasion. An additional lesion was visible with dye endoscopy as an unstained area, but it was not visible with radiography or conventional endoscopy. Dye endoscopy using Lugol solution is very important because it allows detection and evaluation of the extent of esophageal mucosal cancer.

Aged↗
PubMed1997

Nemaline bodies of skeletal muscle fibers of the neck in a case of pharyngeal cancer.

Nemaline bodies were found in the regenerating muscle fibers of the neck of a 74-year-old Japanese male with pharyngeal cancer. Histologically, the nemaline bodies were needle-shaped structures and hematoxophilic with phosphotungstic acid-hematoxylin stain. Electron microscopic examination suggested that they arise as extensions of the Z bands. Although nemaline bodies occur in a variety of pathological conditions other than nemaline myopathy, their occurrence in regenerating skeletal muscle fibers invaded by cancer has not been reported previously. The pathogenesis of the nemaline body formation in the present case is discussed.

Aged↗
PubMed1997

New polyhydroxylated steroidal saponins from the tubers of Brodiaea californica.

New polyhydroxylated steroidal saponins (1, 2) were isolated from the tubers of Brodiaea californica. The structures were determined by spectroscopic analysis and acid-catalyzed hydrolysis. The bisdesmosidic saponin (2) is unique in structure, and is the first representative of a steroidal saponin bearing 6-deoxy-D-gulopyranose among both the steroidal and triterpene saponins reported up to the present.

Chromatography, High Pressure Liquid↗
PubMed1997

Brain metastasis in malignant pleural mesothelioma.

A 55-year-old male who had a remote history of occupational asbestos exposure consulted us because of chest pain. Chest X-ray revealed diffuse pleural thickening and pleural effusion on the right. A diagnosis of malignant mesothelioma, biphasic type was made by needle pleural biopsy. Fourteen months later, the patient died of brain metastasis. At autopsy, malignant mesothelioma of the pleura with metastasis to the brain and bilateral adrenal glands was observed. Brain metastases proven by autopsy are rare in cases of malignant mesothelioma. The ferruginous body count in the lung tissue was 16 per gram of wet weight.

Adrenal Gland Neoplasms↗
PubMed1997

[Eumycotic mycetoma of the lower leg].

Eumycotic mycetomas are extremely rare diseases in Japan. Only four cases have been reported. In the present report, eumycotic mycetoma of right lower leg of a 44-year-old male of Thai origin, resident in Japan for more than five years, was presented. An induration was noticed on the antero-medial side beneath the knee. Computed tomography showed slightly high dense subcutaneous mass-like lesion at the medial side of the right tibia. Though no draining sinus was formed, histologic examination disclosed grains composed of septated hyphae with Splendore-Hoeppli material. Since more people from foreign countries tend to reside in Japan, physicians and pathologists should be aware of various infections which are not commonly found in Japan.

Adult↗
PubMed1996

Up-regulation of Bcl-2 is associated with neuronal DNA damage in Alzheimer's disease.

Cell death and neurofibrillary tangle formation are prominent features of Alzheimer's disease (AD). It has been suggested that DNA damage may reflect neuronal vulnerability. In this context, the Ced homologue Bcl-2 is able to repress a number of cell death programs. Recently we found both numerous nuclei exhibiting DNA damage within neurons in the AD brain and increases in Bcl-2 immunoreactivity. In this study, we examined the relationship between Bcl-2 expression and nuclear DNA damage or tangle formation. Nuclei exhibiting DNA damage were associated with an up-regulation of Bcl-2 expression, whereas tangle-bearing neurons were associated with a down-regulation of Bcl-2 expression.

Aged↗
PubMed1996

A pyrroline glucoside ester and steroidal saponins from Lilium martagon.

A new phenylpropanoid ester of a pyrroline derivative and two new steroidal saponins were isolated from the fresh bulbs of Lilium martagon, along with several previously known compounds. The structures of the new compounds were determined by spectroscopic data, hydrolysis, and by comparison with spectral data of known compounds to be (-)-5-hydroxy-3-methyl-3-pyrrolin-2-one 5-O-(6-O-p-coumaroyl-beta-D- glucopyranoside), (25S)-spirost-5-ene-3 beta,17 alpha, 27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl- (1-->4)-beta-D-glucopyranoside] and (25S)-5 alpha-spirostane-3 beta,17 alpha,27-triol 3-O-[O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl-(1-->4)-bet a-D- glucopyranoside], respectively. Lilium martagon crosses well with L. hansonii to produce a valuable garden hybrid lily. In this study, the secondary metabolites of L. martagon were revealed to be closely related to those of L. hansonii, giving a good example of the correlation between the secondary metabolites and cross-compatibility.

Carbohydrate Sequence↗
PubMed1996

Cervical intra-epithelial neoplasia (CIN) III of the uterine cervix in a young female associated with AIDS.

A case of cervical intraepithelial neoplasia (CIN) III implying severe dysplasia or carcinoma in situ of the uterine cervix in a 24 year old Japanese female patient with acquired immunodeficiency syndrome (AIDS) is reported. Autopsy revealed marked systemic atrophy of lymph nodes, Pneumocystis carinii pneumonia, pulmonary aspergillosis, acute pancreatitis and CIN III of the portio vaginalis uteri. The human papillomavirus (HPV) genome was detected in sections of the CIN III by polymerase chain reaction. This is the first autopsy report of cervical neoplasia in a patient with AIDS in Japan, and the pathogenesis of CIN III in this case was associated with HPV infection. Gynecological examination should be mandatory for female patients with human immunodeficiency virus infection.

AIDS-Related Opportunistic Infections↗
PubMed1996

[A clinical study of squamous cell carcinoma of the tongue base].

Between 1979 and 1992, 27 previously untreated patients with squamous cell carcinoma involving the base of the tongue underwent treatment with curative intent. Seven patients were in Stage I, II (26%) and 20 patients were in stage III, IV (74%). Seventeen patients (63%) presented clinically with neck metastasis. The patients were followed for a minimum of two years or until death or recurrence. Primary tumors treated with surgery or radiotherapy showed control rates of 80% (12 of 15 tumors) and 88% (7 of 8 tumors), respectively. The overall survival was 59 percent at 5 years. For the patients with exophitic primaries, local control with radiotherapy produced excellent results, whereas for advanced or deeply invasive tumors, surgery enhanced local control. Radiation therapy successfully controlled early neck disease (N0, N1). Patients with advanced neck disease (N2, N3) had poor regional control with radiotherapy, necessitating subsequent neck dissection. Forty-three percent of the N2b or N3 patients were found to have contralateral occult metastasis. Results obtained in the present study show that patients with T3, T4 or N2, N3 should undergo surgery. Prospective trials are necessary to compare surgery versus definitive radiotherapy with respect to patient survival and quality of life.

Adult↗
PubMed1996

[Bucillamin induced lung injury in rheumatoid arthritis].

Thirteen cases with rheumatoid arthritis who experienced lung injury during the treatment with bucillamine (Bc), about whom the questionnaires were answered by the physicians and whose X-ray films could be rechecked, were studied. Nine cases out of the 13 showed patchy mottled infiltrates in the bilateral center sparing the periphery, and the other 4 showed diffuse infiltrates. In these 9, serum gamma-globulin level decreased when lung injury appeared. The gamma-globulin level before the start of Bc administration, the level when lung injury appeared, the gamma-globulin decrease, and its ratio to the level before Bc were 1790 +/- 661 mg/dl, 1297 +/- 666 mg/dl, 459 +/- 320 mg/dl and 29.1 +/- 18.0%, respectively. In 5 out of the 9, gamma-globulin level reincreased when they recovered from the injury: 2 out of the 5 showed the reincrease even after steroid therapy. The data were obtained only from 2 out of the 4 with diffuse pattern in X-ray, and the decrease and the decrease ratio were 200 mg/dl (5.8%) in 1, and 49 mg/dl (3.6%) in the other. The characteristics of Bc-induced lung injury might be mottled infiltrates in the center appearing concurrently with serum immunoglobulin decrease.

Aged↗
PubMed1995

Immunoreactivity for Bcl-2 protein within neurons in the Alzheimer's disease brain increases with disease severity.

Bcl-2 protein has been suggested to be one of the proteins preventing apoptosis in a variety of cell types. Recently, apoptosis has been suggested to have an important role in the pathogenesis of Alzheimer's disease (AD). We have utilized Bcl-2 immunohistochemical methods to examine Bcl-2 in the hippocampus and entorhinal cortex of AD patients ranging in clinical and neuropathological severity from mild to severe and compared these results to those obtained from age-matched controls. Immunoreactivity for Bcl-2 was predominantly found within neurons. Bcl-2 immunostaining within AD tissue was increased relative to controls in most neurons of the entorhinal cortex, subiculum, CA1, CA2, CA3, hilus and dentate gyrus. Relative Bcl-2 staining increased in parallel with increasing disease severity. However, neurons exhibiting immunoreactivity for markers of neurofibrillary tangle formation (AT8 and PHF-1) showed reduced Bcl-2 staining, suggesting that Bcl-2 may be down regulated in these degenerating neurons. Bcl-2 immunoreactivity within astrocytes and the vasculature was also increased in AD. These results suggest that Bcl-2 protein may have a role in compensation responses to AD pathology, perhaps affording to the remaining neurons a margin of protection from apoptosis.

Aged↗
PubMed1995

Regional myocardial sympathetic dysinnervation in patients with coronary vasospasm.

The purpose of this study was to assess the presence and location of impaired myocardial sympathetic innervation by using 123I metaiodobenzylguanidine (123I MIBG) in 15 patients with coronary vasospasm induced by intracoronary acetylcholine. The results were compared with those using thallium-201 (Tl-201). We also examined 14 patients with severe coronary stenosis (> 90%) and 8 control subjects without significant coronary stenosis (< 50%) and provokable coronary vasospasm. Regional myocardial sympathetic dysinnervation was detected by 123I MIBG single-photon emission computed tomography (SPECT) in all patients with coronary vasospasm, despite normal uptake during Tl-201 SPECT. This regional uptake-mismatch between 123I MIBG and Tl-201 Spect occurred specifically in the vasospasm group (p < 0.001 vs stenosis and control groups). Moreover, regional myocardial sympathetic dysinnervation was located in the distribution of perfusion in 25 of the 27 vasospasm-induced vessels. Normal uptake of 123I MIBG was observed in the perfused areas in 16 of the 18 non-vasospasm-induced vessels. The sensitivity ans specificity of 123I MIBG for detection of coronary vasospasm were 92% and 88% respectively. In patients with coronary vasospasm, we found regional myocardial sympathetic dysinnervation to be present. Furthermore, we were able to distinguish these patients from patients with critical coronary stenosis by 123I MIBG and Tl-201 SPECT.

3-Iodobenzylguanidine↗
PubMed1995

Gap junctions between fibroblasts in rat myotendon.

We applied conventional and freeze-fracture electron microscopy to study intercellular contacts between the processes of fibroblasts in the myotendon of the rat exterior digitorium longus. The results showed well defined gap junctions between the cell processes, while other cell junctional structures such as tight junctions and desmosomes were not recognizable. The present study suggests that the gap junctions represent a structure to coordinate the activities of fibroblasts distributed in the myotendon of the muscle.

Animals↗