Biomedical subjects
Masato Abe
Publications and source records attributed to Masato Abe.
Progression of the stacked Golgi compartments in the yeast Saccharomyces cerevisiae by overproduction of GDP-mannose transporter.
The Golgi compartments of the yeast Saccharomyces cerevisiaeare dispersed within the cytoplasm, in contrast to the stacked cisternae in the mammalian cell, and consequently are observed as a punctate pattern by immunofluorescent staining of Golgi-marker proteins. The VIG4/VRG4 gene encodes the essential yeast GDP-mannose transporter, which is a polytopic membrane protein in the early and medial Golgi compartments. Upon overexpression of this gene by the aid of a strong promoter and multicopy vector, we found that stacked multivesicular structures, which resembled the cisternae of mammalian Golgi apparatus, had developed in S. cerevisiae. Immuno-electron microscopy showed that the GDP-mannose transporter was located on the stacked cisternae. Immuno-isolation and immunoblotting analyses of the vesicles showed that the overproduced GDP-mannose transporter also co-localized with the Golgi glycosyltransferases, but not with the ER- or late Golgi-marker proteins as in the control cell. We propose that the localization mechanism of the GDP-mannose transporter in the Golgi compartment would be efficient and hardly saturable, and therefore the overproduced protein induced a progression of Golgi-like compartments rather than being mislocalized in other compartments, such as the ER or a vacuole.
Last-intercalated node and direct lymphatic drainage into the thoracic duct from the thoracoabdominal viscera.
OBJECTIVE: We clarified the configuration of the mediastinal lymphatics, focusing on the last intercalated lymph node and the direct drainage vessel to the thoracic duct, based on recent anatomical findings. METHODS: We macroscopically observed the lymphatics during dissections of 205 cadavers in combination with routine histology. We also review the results of injection by other researchers. RESULTS: Efferent vessels draining directly into the thoracic duct or venous angle were frequently found in the following node groups: the right paratracheal node group corresponding to the last intercalated node in 98% of cadavers (201); the brachiocephalic angle node group in 85% of cadavers (174); the right recurrent nerve group in 46% (94); the left superior phrenic node group in 73% (150); the node group at the origin of the left common carotid artery (the preaortico-carotid node) in 37% (76); the pretracheal node group in 25% (51) and the left tracheobronchial node group in 36% (74). Last intercalated nodes appeared common for multiple drainage routes or regional lymphatics. These results were mostly consistent with injection studies by Riquet et al. Direct lymphatic drainage from the esophagus to the thoracic duct was observed in 19% of cadavers (39). Direct lymphatic drainage of lung segments to distant mediastinal nodes is also reviewed. The sentinel node concept is discussed in relation to the above observations. CONCLUSIONS: We hypothesize that the most critical sentinel node, if such usage is allowed, is situated as a guard for a limited specific route and for a common drainage route. We term it the "common terminal node".
Sclerosing mucoepidermoid carcinoma with eosinophilia of the salivary glands.
We encountered two cases of low malignant mucoepidermoid carcinoma with scanty cellular atypism which originated in the parotid or submandibular gland and was characterized by marked fibrosis and eosinophilic infiltration within tumor tissue despite the predominance of the squamous component. Here we report these two cases and provide a review of the literature. We believe that clinically these two tumors with stromal fibrosis and eosinophilic infiltration have a low malignant potential, although histological examination revealed a scanty mucus-producing epithelial component. Therefore, we consider this type of tumor as a new subtype of mucoepidermoid carcinoma. A low-malignant mucoepidermoid carcinoma with stromal fibrosis and eosinophilic infiltration, as described in these two cases, may be misdiagnosed as a highly malignant mucoepidermoid carcinoma or squamous cell carcinoma because of its histologically scanty mucus-producing epithelial component. The objective of this study was to clarify their differences and to discuss the rendering of an accurate histological diagnosis, the degree of malignancy in relation to prognosis prediction, and the choice of therapy. In addition, we propose regarding this type of tumor as a new subtype of mucoepidermoid carcinoma.
Effect of arthrocentesis on TMJ disturbance of mouth closure with loud clicking: a preliminary study.
The objective of this study was to evaluate the short-term effect of arthrocentesis on temporomandibular joint disturbance of mouth closure with loud clicking compared to the effect of one-time pumping into the joint space previous to arthrography. Twenty-one consecutive patients (22 joints) with loud clicking during mouth closure were enrolled. All were unable to smoothly close the mouth without effort. Eleven patients (12 joints) were examined using magnetic resonance imaging (MRI) to determine disk position. They then underwent arthrocentesis. Ten patients (10 joints) underwent arthrography alone as controls. Six months later, changes in clicking and temporomandibular joint movement were analyzed and the disk position was re-examined. There was improvement of mouth closing and clicking occurred in nine joints from the arthrocentesis group and two joints from the control group, with a significant difference between the two groups. Arthrocentesis may be indicated for patients with temporomandibular joint dysfunction and loud clicking when mouth closing.
Changes in P300 latency during the early withdrawal period in chronic alcohol-dependent patients: two case reports.
AIMS: The present study focused on changes in P300 of the event-related potential (ERP) in two patients with alcohol dependence recorded throughout their alcohol withdrawal period. RESULTS: As a result of this investigation, the peak latency of P300 in each patient was significantly shorter 2 or 3 days after abstinence from alcohol, when marked neurological manifestations appeared, compared to that of the control obtained from 8 to 10 days after cessation of drinking. CONCLUSIONS: It seems reasonable to conclude that the shortening of P300 latency reflects the enhancement of brain activity during the early withdrawal period and that an investigation of changes in P300 would be helpful to clarify the nature of neural activity in the brain associated with alcohol withdrawal.