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Y Tashiro

Publications and source records attributed to Y Tashiro.

At least 145 records · Page 8Linked to original sources
PubMed1989

Biosynthesis of nonspecific lipid transfer protein (sterol carrier protein 2) on free polyribosomes as a larger precursor in rat liver.

The biosynthesis of nonspecific lipid transfer protein (nsLTP) was investigated. Total RNA of rat liver was translated in a rabbit reticulocyte lysate cell-free protein-synthesizing system with [35S]methionine as label. The immunoprecipitation of translation products with affinity-purified anti-nsLTP antibody yielded 14.5- and 60-kDa [35S]polypeptides. The molecular mass of the former polypeptide was approximately 1.5 kDa larger than that of the purified mature nsLTP (13 kDa). The site of synthesis of nsLTP was studied by in vitro translation of free and membrane-bound polyribosomal RNAs followed by immunoprecipitation. mRNA for both the 14.5- and 60-kDa polypeptides were found predominantly in the free polyribosomal fraction in both normal and clofibrate-treated rats. Clofibrate, a hypolipidemic drug that proliferates peroxisomes, did not increase the relative amount of nsLTP mRNA in rat liver. Pulse-chase experiments in rat hepatoma H-35 cells suggested that nsLTP was synthesized as a larger precursor of 14.5 kDa and converted to a mature form of 13 kDa. We have recently shown that nsLTP is highly concentrated in peroxisomes in rat hepatocytes [Tsuneoka et al. (1988) J. Biochem. 104, 560-564]. Taken together, these results suggest that nsLTP is synthesized as a larger precursor of 14.5 kDa on cytoplasmic free polyribosomes, then post-translationally transported to peroxisomes, where the precursor is presumably proteolytically processed to its mature form of 13 kDa. The relationship between the 13-kDa nsLTP and the 60-kDa polypeptide is also discussed.

Animals↗
PubMed1989

Distribution of protein disulfide isomerase in rat epiphyseal chondrocytes.

We investigated the intracellular distribution of protein disulfide isomerase (PDI) in rat epiphyseal chondrocytes by immunocytochemistry, using a post-embedding protein A-gold technique. Gold particles were localized primarily in the cisternal space of the rough endoplasmic reticulum (ER) and nuclear envelopes. The ER cisternae of the chondrocytes in all the differentiating epiphyseal zones--resting, proliferative, pre-hypertrophic, and hypertrophic--were equally and highly labeled. The labeling density of the cisternal space of the dilated ER, probably reflecting marked accumulation of secretory proteins such as procollagen, was always higher than that of the non-dilated ER. In the dilated cisternal space, gold particles were freely and evenly distributed, without preferential binding to the luminal surface of the ER membranes. We suggest that PDI catalyzes the formation of disulfide bonds of various secretory proteins, perhaps type II procollagen, in the cisternal space of the ER in epiphyseal chondrocytes. The exclusive localization of gold particles in the cisternal space of the ER and nuclear envelopes and the lack of gold particles in the Golgi apparatus, including cis-Golgi cisternae, indicate that PDI is an ER-soluble protein in the chondrocytes and is presumably sorted out in some pre-Golgi compartment and not transported to the Golgi apparatus.

Aging↗
PubMed1989

Quantitative immunocytochemical localization of Na+,K+-ATPase alpha-subunit in the lateral wall of rat cochlear duct.

Ultrastructural localization of the alpha-subunit of Na+,K+-ATPase on the lateral wall of rat cochlear duct was investigated quantitatively by the protein A-gold method, using affinity-purified antibody against the alpha-subunit of rat kidney Na+,K+-ATPase. In the stria vascularis, gold particles were sparse over the endolymphatic luminal surface of the marginal cells but were numerous over the basolateral membrane. The labeling density of the basolateral membrane was almost equal to that of the same domain of the distal tubule cells of kidney. The intermediate cells were studded with a large number of gold particles on the plasma membrane domain facing the basolateral domain of the marginal cells. On the luminal surfaces of the other epithelial cells, including those of Reissner's membrane, no significant amount of gold particles was found. Many gold particles were localized on all the plasma membranes of the spiral prominence stromal cells and on the intracellular membrane domain of the external sulcus cells.

Animals↗
PubMed1989

Heterogenous distribution of free calcium and propagation of calcium transient in gastric parietal cells revealed by digital imaging microscopy.

Spatial and temporal changes of cytoplasmic free calcium concentration ([Ca2+]i) in single parietal cells of guinea pig were investigated with a digital imaging microscope equipped with a microspectrofluorometer, using a Ca2+-sensitive dye, fura-2. Intracellular distribution of [Ca2+]i was not homogeneous, but there were two kinds of [Ca2+]i gradient in the resting parietal cells, one a continuous gradient increasing towards the plasma membrane and a second discontinuous gradient (Ca2+ plateau) in some restricted regions of the cytoplasm. When treated with gastrin, only about 40% of parietal cells in the gastric gland responded with an almost twofold increase in the average resting [Ca2+]i of 52.4 +/- 7.1 nM. In the responding cells, the discontinuous plateaus transiently enlarged to the entire cytoplasm. In marked contrast, all of these cells responded to Ca2+ ionophore ionomycin. We also found that when provoked by gastrin Ca2+ transient in the parietal cells in the gastric gland often propagated to some adjacent cells, and occasionally spontaneous Ca2+ transient and oscillation were observed even in the resting state.

Animals↗
PubMed1989

Quantitative immunocytochemical localization of Na+,K+-ATPase in rat ciliary epithelial cells.

Ultrastructural localization of Na+,K+-ATPase in rat ciliary epithelium was investigated quantitatively by the protein A-gold technique, using an affinity-purified antibody against the alpha-subunit of Na+,K+-ATPase. Immunoblot analysis showed that the antibody bound specifically to the alpha-subunit of Na+,K+-ATPase in the ciliary body. Gold particles were found mainly on the basolateral surfaces of both the pigmented epithelial (PE) and nonpigmented epithelial (NPE) cells with an approximately twofold higher labeling density in the PE cells. A few gold particles were also found on the apical and ciliary channel surfaces of the PE cells, whereas no significant binding was found on the apical surfaces of the NPE cells. The basolateral surfaces of PE and NPE cells are markedly infolded and are much greater in area than the apical surfaces. This means that Na+,K+-ATPase is almost exclusively located on the basolateral surfaces of both the NPE and PE cells. We suggest that the Na+,K+-ATPase of both the NPE and PE cells play an important role in the formation of aqueous humor.

Animals↗
PubMed1989

Medullary venous malformation with an arterial component associated with a ruptured aneurysm--case report.

We report the rare of occurrence of a medullary venous malformation (MVM) with an arterial component associated with a saccular aneurysm on the opposite side. This 49-year-old male patient was admitted with headache and vomiting. He was diagnosed as having a subarachnoid hemorrhage on the basis of bloody cerebrospinal fluid. Angiography revealed a saccular aneurysm at the junction of the internal carotid and posterior communicating arteries on the left side. A MVM with an arterial component was also seen in the right basal frontal lobe. On the seventh hospital day, the aneurysm was clipped via a left frontotemporal craniotomy. The postoperative course was uneventful. There are many hypotheses concerning cerebral aneurysms; some are thought to derive from persistent primitive arteries in the early fetal period. On the other hand, MVM is thought to be intimately related to arteriovenous malformation, which is believed to develop from the premordial vascular plexus, also in early fetal life.

Brain Neoplasms↗
PubMed1989

[A comparative study of the sensitivity of bladder washing flow cytometry, voided urine cytology and bladder washing cytology in the detection of bladder carcinoma].

In order to evaluate flow cytometric deoxyribonucleic acid measurement (FCM) of bladder washing in the diagnosis of bladder carcinoma, the sensitivity of voided urine cytology, bladder washing cytology and bladder washing FCM was tested in 76 samples from 56 patients with histologically proven bladder carcinomas. The positive rates were 43.2% and 75.7% in bladder washing cytology and bladder washing FCM, respectively. On the other hand, 36.5% and 57.1% positive rates for once- and three-times-voided urine cytology, respectively, were obtained. Bladder washing cytology and bladder washing FCM were positive in 20% and 70% patients with a histological diagnosis of atypia or dysplasia, respectively. The sensitivity of bladder washing FCM according to the tumor grade was 33.3%, 81.9% and 88.9% for grade-1 (G-1), G-2 and G-3 tumors, respectively. The sensitivity of bladder washing cytology according to the tumor grade was 0, 40.9% and 77.8% for G-1, G-2 and G-3 tumors, respectively. The sensitivity of three-times-voided urine cytology was 25.0%, 55.6% and 83.3% for G-1, G-2 and G-3 bladder tumors, respectively, and it was superior to that of single bladder washing cytology. These results indicate that FCM is more sensitive than voided urine cytology and/or bladder washing cytology in patients with bladder carcinoma. FCM may indicate urothelial neoplasia before it is apparent on urine cytology, especially against a background of inflammation. Therefore, FCM is valuable for case finding in suspect populations or for follow-up cases with diagnosed bladder cancer.

DNA, Neoplasm↗
PubMed1989

[A clinicopathological study of the extension modes of hepatocellular carcinoma evaluated from surgically removed and autopsied cases--the prognostic factors and operability].

Twenty-six surgically removed and 57 autopsied hepatomas have been examined with reference to such extension factors as tumor size and location, serosal involvement, vascular involvement, remote and lymphatic, as well as to intrahepatic metastasis. Significant differences were found with regard to each of these factors between the two studied groups. In the surgical group, cases exhibiting expansive growth with capsular formation, occupation of a single segment, and no intrahepatic metastasis showed a favorable outcome, whereas the distance to the surgical margin and the vascular involvement did not affect the outcome. The surgical removal of the tumor emboli together with the main tumor was successful in one case.

Adult↗
PubMed1988

Spatial distribution and temporal change of cytoplasmic free calcium in human platelets.

Our digital imaging microscope equipped with a microspectrofluorometer revealed in single resting human platelets the existence of continuous Ca2+ gradient increasing towards the plasma membrane (frequency; 100%) and discontinuous ones (Ca2+ plateaus) in the endoplasmic regions (frequency: 70%). An average cytoplasmic free Ca2+ concentration ([ Ca2+]i) in a whole cytoplasm was 72 +/- 7 nM, ranging from 30 nM in the lowest to 150 nM in the highest region just beneath the plasma membrane. When stimulated with thrombin, [Ca2+]i uniformly increased to the average [Ca2+]i of 300 nM and these gradients disappeared. This [Ca2+]i transient was followed by the sustained increase in [Ca2+]i in both single cells and cell suspension.

Blood Platelets↗
PubMed1988

Fluorescence digital image analysis of the inositol trisphosphate-mediated calcium transient in single permeabilized parietal cells.

The myo-inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ mobilization in single saponin-permeabilized and fura-2-loaded parietal cells was analysed by a fluorescence digital image processor. When the cells were incubated with ATP, free cytoplasmic Ca2+ concentration [( Ca2+]i) increased in some restricted cytoplasmic regions showing discontinuous plateau and in the peripheral cytoplasm showing continuous [Ca2+]i gradient towards the plasma membranes. When treated with IP3, the high plateau enlarged to the entire cytoplasm and (a) new higher plateau(s) appeared and enlarged again in a transient manner. The IP3-induced Ca2+ transient was also observed by fluorescence microphotometry of the single cells or by fluorescence spectrophotometry and 45Ca2+ uptake experiment of the cell population.

Animals↗
PubMed1988

Calcification of a ventriculoperitoneal shunt tube. Case report.

A 16-year-old boy who had undergone a ventriculoperitoneal (VP) shunt because of hydrocephalus at 8 years of age complained of pain around the right neck and chest. He concomitantly had a slight fever of unknown etiology, which had been lasting for several years. Skull and chest roentgenograms revealed an unusual calcified shadow around the shunt tube. After removal of the shunt apparatus, his pain and fever disappeared. Silicone tubes used in a VP shunt apparatus may induce fibrous connective tissue proliferation around the tubes in both children and adults, but no reports of radiologically verified calcification of a VP shunt tube are found in the literature, to the best of our knowledge. The possible mechanism of calcification of the VP shunt tube is discussed.

Adolescent↗
PubMed1988

Nonspecific lipid transfer protein (sterol carrier protein-2) is located in rat liver peroxisomes.

Intracellular localization of nonspecific lipid transfer protein (nsLTP) in rat hepatocytes was investigated by immunoblot analysis of the subcellular fractions and immunoelectron microscopy, using affinity-purified antibody against nsLTP. Immunoblot analysis showed that the protein exists in the peroxisomal and cytosolic fractions. Further study indicated that nsLTP exists in the soluble subfraction of the peroxisomes. Immunoelectron microscopic observation revealed that nsLTP is highly concentrated in the matrices of the peroxisomes. From these results, we concluded that nsLTP mainly exists in the matrix of the peroxisomes. The role of nsLTP is discussed.

Animals↗
PubMed1988

Effects of water-immersion restraint stress on rat gastric epithelial cell loss and migration.

The effect of water-immersion restraint stress on cell loss and migration was studied in rats. In order to label the proliferating cells, tritiated thymidine was injected 72 h prior to the stress. Histoautoradiography was prepared for the measurement of cell migration and residual mucosal DNA-bound radioactivity by means of liquid scintillation count for cell loss. Residual DNA-bound radioactivity was significantly decreased in fundic mucosa, but not in antral mucosa, after 60-90 min of water-immersion restraint stress. Cell migration was also found to be accelerated in fundic mucosa after 90 min of stress. These results indicate that water-immersion restraint stress results in an increase of cell loss, which is accompanied by compensated acceleration of cell migration, in fundic mucosa of rats before the development of gastric erosions. In view of the previous observation that stress for the same short-term duration inhibits fundic epithelial proliferation in rats, this combination, increased cell loss with depressed epithelial proliferation, may contribute to stress-related gastric mucosal lesions in rats.

Animals↗
PubMed1988

Distribution of protein disulfide isomerase in rat hepatocytes.

We investigated quantitatively the distribution of protein disulfide isomerase (PDI) in rat hepatocytes by immunocytochemistry using a post-embedding protein A-gold technique. In hepatocytes, gold particles were mainly localized in the intracisternal space of the rough and smooth endoplasmic reticulum (ER) and nuclear envelopes. Autolysosomes engulfing ER were occasionally densely labeled, especially in rat hepatocytes previously treated with leupeptin in vivo, suggesting that the autophagosome-autolysosome system may be an important route for degradation of PDI. A few gold particles were also found on the plasma membranes. Localization of gold particles on the other subcellular organelles, such as Golgi apparatus, peroxisomes, and nuclear matrix, was sparse and at the control level. The predominant localization of PDI on the intracisternal surface of the ER and nuclear envelope supports a potential role of PDI in the formation of disulfide bonds of nascent polypeptides, thus accelerating formation of the higher-order structure of secretory and membrane proteins and rendering the translocation process irreversible.

Animals↗
PubMed1988

Localization of protein disulfide isomerase on plasma membranes of rat exocrine pancreatic cells.

We investigated immunocytochemically the ultrastructural localization of protein disulfide isomerase (PDI) in rat pancreatic exocrine cells by use of the post-embedding protein A-gold technique. We found that not only the endoplasmic reticulum (ER) and nuclear envelope but also the trans-Golgi cisternae, secretory granules, and plasma membranes were heavily labeled with gold particles. Labeling density of the gold particles in the rough ER and plasma membranes of the exocrine pancreatic cells was twofold and twentyfold greater, respectively, than that of hepatocytes. In the acinar lumen, amorphous material presumably corresponding to the secreted zymogens was also labeled with gold particles. These results suggest that in rat exocrine pancreatic cells a significant amount of PDI is transported to the plasma membrane and secreted to the acinar lumen.

Animals↗
PubMed1988

Visualization of cytosolic free calcium distribution and mobilization in guinea pig gastric chief cells.

Distribution and temporal change of free calcium concentration [( Ca2+]i) in single guinea pig gastric chief cells were visualized by a digital imaging microscope equipped with a microspectrofluorometer. The distribution was not homogeneous; a higher [Ca2+]i area was often localized in some restricted regions of the endoplasm and also at the peripheral cytoplasm just beneath the plasma membrane. When stimulated with cholecystokinin, [Ca2+]i increased transiently in the apical peripheral cytoplasm and in the endoplasmic regions. This Ca2+ mobilization which precedes the biphasic pepsinogen secretion was composed of a rapid Ca2+ release from the intracellular store(s) as well as a rapid and a more sustained Ca2+ entry from the extracellular space.

Animals↗
PubMed1988

[A glomus tumor of the stomach associated with a lipoma].

A case of Glomus tumor of the stomach associated with a lipoma in a 65-year-old female is reported. The patient complained of epigastralgia for three months prior to her admission. X-rays, as well as gastroscopic examinations, revealed two submucosal tumors, one located along the greater curvature of the gastric antrum and the other on the posterior wall of the upper corpus. A preoperative angiographic study showed hypervascularity and tumor staining. Histologically, one tumor was diagnosed as being Glomus tumor and the other, a lipoma. Thus this rare case of two submucosal tumors in the stomach is discussed and 39 previous gastric Glomus tumor cases found in the domestic literature are reviewed.

Aged↗