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Biomedical subjects

Y Tashiro

Publications and source records attributed to Y Tashiro.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Health care in view of daily medical examination].

The present situation in health care From the perspective of regional society, there are many public facilities which support the health, medication and welfare for the residents, and they operate their own service without an appropriate linkage or organized method of sharing information with each other. It is important to provide health care based on a principle with a concept of health information management by life stage. As present, such information is divided among several government agencies, namely the Ministries of Health and Welfare, Education and Labor. Infant, school medical exam, and adult or geriatric annual check-ups are under the control of the respective Ministries. As a result, we lack in communication between regional facilities and sharing information. Recent advancement in medical information systems and instruments have been remarkable. Especially after the electronic medical card will be in officially used, the medical check supporting system will gradually come into wide-spread use with easy operation. To swim with the current of the times, it is important to cooperate with organizations in other fields for practical use of personal health data. We must make an effort to establish an effective method of using computer and individual information to collect significant data.

Delivery of Health Care↗
PubMed1999

Distinct characteristics of receptor-operated Ca2+ influx and refilling in pancreatic acinar cells.

Ca2+ influx from the extracellular space in nonexcitable cells occurs via receptor-operated and refilling processes. However, they showed different characteristics with respect to the Mn2+ permeability, depletion of intracellular Ca2+ stores, and sensitivity to the K+ ionophore valinomycin in rat pancreatic acinar cells. While Mn2+ did not enter into the cells during the refilling phase, the opposite was true in receptor-operated Ca2+ influx (ROCI) evoked by carbachol (CCh). ROCI occurred in the absence of intracellular Ca2+ release from the stores. Valinomycin abolished the second response of Ca2+ elicited by CCh, whereas it had no effect on ROCI. These observations suggest that receptor-operated Ca2+ channels (ROCCs) and refilling channels may be different in rat pancreatic acinar cells.

Animals↗
PubMed1999

A 60 kDa plasma membrane protein changes its localization to autophagosome and autolysosome membranes during induction of autophagy in rat hepatoma cell line, H-4-II-E cells.

We previously reported the preparation and characterization of an antibody against membrane fraction of autolysosomes from rat liver (J. Histochem. Cytochem. 38, 1571-1581, 1990). Immunoblot analyses of total membrane fraction of a rat hepatoma cell line, H-4-II-E cells by this antibody suggested that H-4-II-E cells expressed several autolysosomal proteins, including a protein with apparent molecular weight of 60 kDa. It was suggested that this 60 kDa protein was a peripheral membrane protein, because it was eluted from the membrane by sodium carbonate treatment. We prepared an antibody against this 60 kDa protein by affinity purification method, and examined its behavior during induction of autophagy. Autophagy was induced by transferring the cells from Dulbecco's modified Eagle medium (DMEM) containing 12% fetal calf serum into Hanks' balance salt solution. In DMEM, the 60 kDa protein showed diffused immunofluorescence pattern, and immunoelectron microscopy suggested that this protein was located on the extracellular side of the plasma membrane. After inducing autophagy, the immunofluorescence configuration of the 60 kDa protein changed from the diffused pattern to a granulous one. Immunoelectron microscopy showed that the 60 kDa protein was localized on the luminal side of the limiting membrane of autolysosomes and endosomes. In the presence of bafilomycin A1 which prevents fusion between autophagosomes and lysosomes, the 60 kDa protein was localized on the limiting membrane of the autophagosomes and endosomes. These results suggest that the 60 kDa protein is transported from the plasma membrane to the autophagosome membrane through the endosomes.

Animals↗
PubMed1999

[A case of eosinophilic gastroenteritis complicated with ileus and ascites collection].

A 30-year-old woman was admitted to our hospital because of ileus and ascites. Laboratory data on admission demonstrated marked eosinophilia (42.5% of WBC) but negative CRP-value. Abdominal CT showed marked ascites and diffuse thickening of intestinal walls. Ascites examination revealed eosinophilic ascites. The level of IL-5 both in the serum and in the ascites were also high. No evidence of eosinophilic infiltration was noted both gastric and colonic mucosal biopsy specimens. Oral prednisolone treatment (50 mg/day) was effective for her. We diagnosed her as a case of sub-serosal type eosinophilic gastroenteritis. It is essential to obtain eosinophilic ascites for correct diagnosis of the disease. And it is possible that serum and ascites IL-5 value would be reliable indicator of the activity of this disease.

Adult↗
PubMed1998

Identification of estrogen-modified nucleosides from calf thymus DNA reacted with 6-hydroxyestrogen 6-sulfates.

Two estrogen sulfates, pyridinium 3-methoxyestra-1,3, 5(10)-trien-6alpha-yl sulfate (3MeE-6alpha-S) and its 6beta-isomer (3MeE-6beta-S), synthesized as model compounds to demonstrate the carcinogenesis of estrogen, were found to react with calf thymus DNA to produce steroid-modified DNA adducts. Digestion of the DNA by nuclease P1 and phosphodiesterase I followed by alkaline phosphatase gave a deoxyribonucleoside fraction, of which N2-[3-methoxyestra-1,3, 5(10)-trien-6alpha-yl]deoxyguanosine, N2-[3-methoxyestra-1,3, 5(10)-trien-6beta-yl]deoxyguanosine, N6-[3-methoxyestra-1,3, 5(10)-trien-6beta-yl]deoxyadenosine, and N6-[3-methoxyestra-1,3, 5(10)-trien-6alpha-yl]deoxyadenosine (identified as a base adduct) were identified using HPLC by comparing them with authentic specimens prepared by reacting dG and dA with both sulfates. No steroid-dC adduct was detected in the digestion products of the DNA adduct, although dC reacted with the sulfates to form N4-[3-methoxyestra-1,3,5(10)-trien-6beta-yl]deoxycytidine. These results mean that estrogen 6-sulfate has an ability to modify DNA via the amino group of a guanine or adenine residue in DNA. The present studies imply that a sequential metabolism (hydroxylation and sulfation) at the C6-position of the estrogen molecule causes damage to DNA.

Animals↗
PubMed1998

Important roles of the C-terminal portion of HPC-1/syntaxin 1A in membrane anchoring and intracellular localization.

HPC-1/syntaxin 1A (HPC-1), which plays an important role in vesicular transport to the plasma membrane, possesses a hydrophobic sequence at its C terminus. When expressed from cDNA in COS cells, wild-type HPC-1 was localized in the Golgi complex and the plasma membrane. Truncation of the hydrophobic domain resulted in the cytoplasmic localization of the mutant, thus indicating that the domain indeed functions as a membrane anchor. A fusion protein with the C-terminal glycosylation sites was glycosylated in transfected cells, providing evidence that HPC-1 has a transmembrane structure, and that the protein is first inserted into the endoplasmic reticulum and then transported to the plasma membrane. A chimeric protein consisting of Escherichia coli maltose-binding protein with the last 24 amino acids of HPC-1 was inserted into the endoplasmic reticulum in a transmembrane topology and localized along the exocytic pathway of transfected cells similar to HPC-1. These results indicate that the portion is important for intracellular localization of HPC-1.

Amino Acid Sequence↗
PubMed1998

Bafilomycin A1 prevents maturation of autophagic vacuoles by inhibiting fusion between autophagosomes and lysosomes in rat hepatoma cell line, H-4-II-E cells.

We studied the effects of bafilomycin A1, a potent and specific inhibitor of vacuolar H+ ATPase (V-ATPase), on the process of autophagy in rat hepatoma cell line, H-4-II-E cells. To induce autophagy, cells were transferred from Dulbecco's modified Eagle medium containing 12% fetal calf serum into Hanks' balanced salt solution. When bafilomycin A1 was added to Hanks' balanced salt solution, endogenous protein degradation was strongly inhibited and numerous autophagosomes accumulated in H-4-II-E cells, whereas autolysosomes decreased in number. Acid phosphatase activity was not detected in the autophagosomes which accumulated in the presence of bafilomycin A1, suggesting that fusion between autophagosomes and lysosomes was disturbed by this drug. Inhibition of the fusion was reversible, and the autophagosomes changed into autolysosomes after the removal of the inhibitor. Bafilomycin A1 also prevented the appearance of endocytosed HRP in autophagic vacuoles. These results suggested that acidification of the lumenal space of autophagosomes or lysosomes by V-ATPase is important for the fusion between autophagosomes and lysosomes.

Amino Acids↗
PubMed1998

Rough surfaced smooth endoplasmic reticulum in rat and mouse cerebellar Purkinje cells visualized by quick-freezing techniques.

The in vivo structure of the smooth endoplasmic reticulum (ER) was visualized in rat and mouse cerebellar Purkinje cells by using quick-freezing techniques followed by freeze-substitution for ultrathin-sectioning or freeze-fracturing and deep-etching for replicas. High magnification electron microscopy of the ultrathin sections revealed a surprising finding that all the smooth ER are apparently rough surfaced, and heavily studded with a large number of small dense projections. In the soma the smooth ER appears to be similar to its rough counterpart, except that the projections are slightly smaller, less electron dense and less protrusive on the ER membranes than the ribosomes. The projections were short rectangles, 20 x 20 x 6 nm3 in size, covering the cytoplasmic surface of the smooth ER in a checker-board manner where closely packed. After freeze-etching and replication, they appeared to be composed of four subparticles, surrounding a central channel. Thus the projections are very similar to the foot structure (ryanodine receptor) of the sarcoplasmic reticulum. Furthermore, they were distributed exclusively in the ER compartment and were highly concentrated especially in the smooth ER. This localization of the projections coindides with the intracellular distribution of the inositol 1,4,5-trisphosphate (IP3) receptor determined by quantitative immunogold electron microscopy. These findings would suggest that the projections are tetramers of IP3 receptor molecules and could be used as a morphological marker for the smooth ER in Purkinje cells, which spreads from the soma to the axon and dendrite, up to the tips including the spines. In Purkinje cells tubular smooth ER runs freely in a serpentine fashion or are intertwined to make large membraneous tangles without forming cisternal stacks. It is highly probable that the ER cisternal stacks do not exist naturally in Purkinje cells but are formed artificially during the various procedures for chemical fixation.

Animals↗
PubMed1998

Reversibility of functionally injured neurotransmitter systems with shunt placement in hydrocephalic rats: implications for intellectual impairment in hydrocephalus.

UNLABELLED: Intellectual impairment has been related to alteration of neuronal innervation in the following regions: cholinergic basal forebrain nuclei (Ch1-Ch6, learning and memory), dopaminergic ventral tegmental area (emotional control), and noradrenergic locus ceruleus (cognition). Recent studies have implicated neuronal injury in the pathogenesis of hydrocephalus. OBJECT: The authors used immunohistochemical techniques to investigate functional injury in these regions in animals with progressive hydrocephalus, following shunt placement for cerebrospinal fluid (CSF) drainage. METHODS: Hydrocephalus was induced in 20 Wistar rats by intracisternal injection of 0.05 ml of 25% kaolin solution. Four control animals (Group 1) received the same volume of saline. Ventriculoperitoneal shunts were inserted in eight rats at 2 and 4 weeks after kaolin injection and the animals were killed at 8 weeks (Group 2). The other 12 hydrocephalic animals were killed at 2, 4, and 8 weeks without undergoing shunt placement (Group 3). Immunoreactive (IR) neurons to choline acetyltransferase (ChAT) in Ch1-Ch6, tyrosine hydroxylase (TH) in the ventral tegmental area, and dopamine B-hydroxylase (DBH) in the locus ceruleus, as well as IR projection fibers in the terminal areas, were compared between groups. The number of ChAT- and TH-IR neurons in rats with and without shunt placement was counted for quantitative analysis. The number of ChAT-IR neurons was progressively reduced during the development of hydrocephalus in Ch1, Ch2, Ch3, and Ch4 (p < 0.05). Tyrosine-hydroxylase-immunoreactive neurons were also reduced in number, and demonstrated decreased projection fibers and terminals. Early shunting (at 2 weeks) restored ChAT and TH immunoreactivity to control levels, but late shunting (at 4 weeks) did not (p < 0.05). The DBH-IR neurons in the locus ceruleus were remarkably compressed by the dilated fourth ventricle, and diminished immunoreactivity was observed in the terminal areas. Shunt placement for CSF also restored the immunoreactivity in this system. CONCLUSIONS: These findings indicate that a progressive functional injury occurs in the cholinergic, dopaminergic, and noradrenergic systems as a result of hydrocephalus. This may contribute to intellectual impairment and might be prevented by early treatment with shunt placement.

Animals↗
PubMed1998

A study on development of a home health care support information system.

As the need for home health care has been increasing with the rising number of the elderly in Japan, the application of medical informatics to home health care delivery is considered to be useful. Therefore, development of a home health care support information system was planned. The system can collect patient's PHD (Personal Health Data) such as data of ECG, complaints, etc. at patient's home and can send the PHD to medical facilities. We designed and constructed two subsystems on a trial basis. One subsystem has function of gathering, recording and transmitting vital signs of the aged such as ECG, physical activity rate, oxygen saturation rate in arterial blood. Another subsystem can collect and send image data of the old people at their home. Experiments for trial use of the system was conducted and it was recognized that the PHD can be smoothly collected and recorded at home of the elderly and can be sent to the medical facilities with good success by using the system.

Aged↗
PubMed1998

[Pneumonia caused by granulomatous Pneumocystis carinii in a patient with the acquired immunodeficiency syndrome].

A 54-year-old man was admitted to the hospital because of fever and general fatigue. A chest roentgenogram on admission showed lobular opacities and ill-defined opacities in both lower lobes. The pneumonia was successfully treated with antibiotics. The acquired immunodeficiency syndrome was diagnosed because ELISA and PCR tests for antibodies to the human immunodeficiency virus were positive and the CD 4+ lymphocyte count was 39 per cubic millimeter. Examination of bronchoalveolar lavage fluid revealed no Pneumocystis carinii. Trimethoprim and sulfamethoxazole were given prophylactically, but were withdrawn because of a rash. The patient began to receive aerosolized pentamindine and was discharged. On the next day, he was readmitted to the hospital because of a high fever. A chest roentgenogram showed diffuse miliary opacities. Chest CT scan also showed diffuse small nodular opacities in both lungs. Examination of a transbronchial biopsy specimen revealed well-defined, noncaseating granulomas with pneumocystis organisms in their centers. Cultures for tuberculosis and fungi were all negative. We diagnosed granulomatous pneumonia caused by Pneumocystis carinii, which is an atypical manifestation of Pneumocystis carinii pneumonia. The patient died of sepsis and cardiac tamponade. Microscopically, the lung tissue was found to have foamy intra-alveolar exdates, which is a typical histological feature of Pneumocystis carinii pneumonia.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Pulmonary actinomycosis with "balls-in-a hole" appearance diagnosed by examination of bronchial lavage fluid].

A 49-year-old man was referred to our hospital because of abnormal chest X-ray findings. Chest X-ray films showed infiltrative opacities in the right lung, and histological findings of a transbronchial biopsy specimen showed non-specific inflammation. The patient was treated with Ofloxacin for one month. After the treatment, chest X-ray films showed that the infiltrative opacities in the right upper lobe had decreased, but that opacities in the right lower lobe had increased, with an air meniscus sign. A chest computed tomography scan at the same time revealed that the remaining opacities contained multiple mass-like lesions within a cavity in the right S6, appearing as "balls in a hole". One year after the first visit, the patient visited the hospital again because of cough and sputum. A chest X-ray film showed that the size of the cavity in the right lower lobe had increased. The histological findings from a fresh transbronchial biopsy specimen revealed a non-specific inflammation again; however, black clots obtained from bronchial lavage fluid after biopsy were histologically identified as sulfur granules, a classic pathological indication of actinomycosis. This confirmed the diagnosis of pulmonary actinomycosis. The patient was treated with penicillin, and the opacities in the right lower lobe subsided.

Actinomycosis↗
PubMed1997

Functional injury of cholinergic, GABAergic and dopaminergic systems in the basal ganglia of adult rat with kaolin-induced hydrocephalus.

Structural and/or functional injury of the basal ganglia can lead to motor functional disabilities, abnormal gait and posture, and intellectual/emotional impairment, disorders also frequently seen in hydrocephalus. Previous reports have documented changes in dopamine levels in the neostriatum in experimental hydrocephalus. The present study was designed to investigate possible functional injury of cholinergic, GABAergic and dopaminergic systems in the basal ganglia immunohistochemically in a model of kaolin-induced hydrocephalus. Hydrocephalus was induced in 12 Wistar rats by intracisternal injection of 0.05 ml volume of 25% kaolin solution under microscopic guidance. Four controls received an equal volume of sterile saline. The animals were killed at 2, 4 and 8 weeks after injection. The numbers of choline acetyltransferase (ChAT)- and glutamic acid decarboxylase (GAD)-immunoreactive (IR) neostriatal neurons and tyrosine hydroxylase (TH)-IR nigral neurons, were counted in 60-micron thick representative sections and the IR cellular densities (counted cell number/neostriatal area) were calculated in the neostriatum. The number of total neostriatal neurons was also counted in 15-micron thick sections stained by cresyl violet (Nissl staining) to calculate the cellular density. The number and cellular density of neostriatal ChAT-IR neurons were significantly reduced at 2, 4, and 8 weeks after injection (P < 0.05), while those of GAD-IR neurons decreased at 4 and 8 weeks (P < 0.05). There was a linear correlation between degree of ventricular enlargement, and reduction in number of ChAT- and GAD-IR neurons (P < 0.001) as well as in the cellular density (P < 0.001). However, Nissl staining revealed no reduction in the cellular density of total neostriatal neurons (P < 0.001). TH immunoreactivity was reduced in neostriatal axons and in nigral compacta neurons, particularly in the medial portion of the dopaminergic nigrostriatal pathway. These findings suggest that progressive hydrocephalus results in functional injuries of cholinergic and GABAergic neurons in the neostriatum and dopaminergic neurons in the substantia nigra compacta by mechanical distortion. The disturbance in balance of these neurotransmitter systems in the basal ganglia may explain some of motor functional disabilities in hydrocephalus.

Acetylcholine↗
PubMed1997

Epstein-Barr virus-positive multiple early gastric cancers and dysplastic lesions: a case report.

Epstein-Barr virus (EBV) has been implicated as a causal virus of gastric cancer with episomal monoclonality, elevated antibodies and a unique morphologic expression in the early intramucosal stage, but the infection mechanisms have not been demonstrated. EBV has been shown only in the cancerous lesions by the highly sensitive EBV-encoded small RNA in situ hybridization (EBER-ISH) method, not in the dysplastic mucosa adjacent to the cancer. A case is presented of multiple EBV-positive gastric cancer and dysplastic epithelium observed in a 52-year-old man. Serial cut sections of the gastrectomy specimen showed four small cancerous lesions, three of which were EBER-positive, and three EBER-positive, minute, non-cancerous dysplastic lesions. The three cancerous lesions were intramucosal cancer, with one having minimal submucosal invasion forming a lymphoepithelioma-like histology. All of these EBER-positive cancerous and dysplastic lesions showed intense CD8 T-lymphocytic infiltration. There was no such findings in the EBV-negative cancerous lesion. It was concluded that EBV infection may occur in the epithelial cells of atrophic gastric mucosa, and progress to cancer with monoclonal expansion through the EBV-positive dysplastic change. Cytotoxic T-lymphocytic reactions can occur even in the dysplastic lesions. Multifocal EBV infection in the gastric mucosa may occur and, if necessary, total gastrectomy is recommended in such a case.

Herpesviridae Infections↗
PubMed1997

Progressive loss of glutamic acid decarboxylase, parvalbumin, and calbindin D28K immunoreactive neurons in the cerebral cortex and hippocampus of adult rat with experimental hydrocephalus.

The authors investigated functional neuronal changes in experimental hydrocephalus using immunohistochemical techniques for glutamic acid decarboxylase (GAD) and two neuronal calcium-binding proteins: parvalbumin (PV) and calbindin D28K (CaBP). Hydrocephalus was induced in 16 adult Wistar rats by intracisternal injection of a kaolin solution, which was confirmed microscopically via atlantooccipital dural puncture. Four control rats received the same volume of sterile saline. Immunohistochemical staining for GAD, PV, and CaBP, and Nissl staining were performed at 1, 2, 3, and 4 weeks after the injection. Hydrocephalus occurred in 90% of kaolin-injected animals with various degrees of ventricular dilation. In the cerebral cortex, GAD-, PV-, and CaBP-immunoreactive (IR) interneurons initially lost their stained processes together with a concomitant loss of homogeneous neuropil staining, followed by the reduction of their total number. With progressive ventricular dilation, GAD- and PV-IR axon terminals on the cortical pyramidal cells disappeared, whereas the number of CaBP-IR pyramidal cells decreased, and ultimately in the most severe cases of hydrocephalus, GAD, PV, and CaBP immunoreactivity were almost entirely diminished. In the hippocampus, GAD-, PV-, and CaBP-IR interneurons demonstrated a reduction of their processes and terminals surrounding the pyramidal cells, with secondary reduction of CaBP-IR pyramidal and granular cells. On the other hand, Nissl staining revealed almost no morphological changes induced by ischemia or neuronal degeneration even in the most severe cases of hydrocephalus. Hydrocephalus results in the progressive functional impairment of GAD-, PV-, and CaBP-IR neuronal systems in the cerebral cortex and hippocampus, often before there is evidence of morphological injury. The initial injury of cortical and hippocampal interneurons suggests that the functional deafferentation from intrinsic projection fibers may be the initial neuronal event in hydrocephalic brain injury. Although the mechanism of this impairment is still speculative, these findings emphasize the importance of investigating the neuronal pathophysiology in hydrocephalus.

Analysis of Variance↗
PubMed1997

[Palliative intubation of esophageal prosthesis in two patients with lung cancer].

Case one: A 61-year-old man was admitted to the hospital because of coughing. Adenocarcinoma of the lung was diagnosed. The patient was treated with bronchial artery infusion of cisplatin and mitomycin C, followed by irradiation; and there was a partial response. Eighteen months later he was admitted to the hospital because of dysphagia. An esophageal prosthesis was inserted because of esophageal stenosis surrounded by local recurrent tumor. After intubation, the patient was able to eat and was discharged. Although the patient died 5 months later, the tube was patent and functional until that time. Case two: A 63-year-old man was admitted to the hospital because of coughing. Adenocarcinoma of the lung was diagnosed. The patient was treated with 3 cycles of chemotherapy consisting of cisplatin, vindesine, and mifomycin C, which were followed by irradiation; and there was a partial response. Six months later he was admitted to the hospital because of dysphagia. An esophageal prosthesis was inserted because of esophageal stenosis surrounded by mediastinal lymph nodes. Although the patient was able to eat, bilateral pleuritis and mediastinitis developed and he died ten days after intubation. At autopsy the esophagus was found to have been perforated. Palliative intubation of an esophageal prosthesis can be effective in patients with esophageal stenosis due to lung cancer, but care must be taken to prevent fatal complications.

Adenocarcinoma↗