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T Nishida

Publications and source records attributed to T Nishida.

At least 19 recordsLinked to original sources
PubMed1992

A nucleoside transporter is functionally linked to ectonucleotidases in rat liver canalicular membrane.

Prevention of nucleoside loss in bile is physiologically desirable because hepatocytes are the main source of nucleosides for animal cells which lack de novo nucleoside biosynthesis. We have demonstrated a Na+ gradient-energized, concentrative nucleoside transport system in canalicular membrane vesicles (CMV) from rat liver by studying [3H]adenosine uptake using a rapid filtration technique. The Na(+)-dependent nucleoside transporter accepts purine, analogues of purine nucleosides and uridine; exhibits high affinity for adenosine (apparent Km, 14 microM); is not inhibited by nitrobenzylthioinosine or dipyridamole, and is present in CMV but not in rat liver sinusoidal membrane vesicles. Adenosine transport in right side-out CMV was substantially greater than with inside-out CMV. CMV also contain abundant ecto-ATPase and ecto-AMPase (5'-nucleotidase). These ectoenzymes were shown to degrade nucleotides into nucleosides which were conserved by the Na(+)-dependent nucleoside transport system.

Adenosine↗
PubMed1992

Effects of substitutions of glycine and asparagine for serine132 on activity and binding of human lipoprotein lipase to very low density lipoproteins.

For studying the role of Ser132 in the putative catalytic site of human lipoprotein lipase (LPL), mutant LPL cDNAs expressing LPLs with amino acid substitutions of Gly or Asn for Ser132 were obtained by site-directed mutagenesis, and were expressed in COS-1 cells. Considerable amounts of LPL enzyme protein mass were detected in the culture medium of COS-1 cells transfected with wild-type LPL, LPL-Gly132, or LPL-Asn132. LPL-Gly132 hydrolyzed Triton X-100-triolein and tributyrin as effectively as wild-type LPL, whereas LPL-Asn132 showed no activity. LPL-Asn132 bound to very low density lipoproteins as effectively as wild-type LPL.

Amino Acid Sequence↗
PubMed1992

A heterozygous mutation (the codon for Ser447----a stop codon) in lipoprotein lipase contributes to a defect in lipid interface recognition in a case with type I hyperlipidemia.

Previously, we reported a case with type I hyperlipidemia due to a lipid interface recognition deficiency in lipoprotein lipase (LPL) (1). The LPL from postheparin plasma of this patient did not hydrolyze TritonX-100-triolein or very low density lipoprotein-triolein but did hydrolyze tributyrin and LysoPC-triolein substrates. Sequence analysis of the probands DNA revealed a heterozygous nucleotide change: a C----G transversion at position of 1595, resulting in changing the codon for Ser447 to a stop codon. Expression studies of this mutant LPLcDNA in Cos-1 cells produced and secreted considerable amounts of LPL mass in the culture media. The mutated LPL hydrolyzed much less TritonX-100-triolein than wild type LPL, whereas hydrolysis of tributyrin and LysoPC--triolein was the same with both the mutant and wild type LPL. These results suggest that this mutation might be responsible for the property of the LPL with a defect in lipid interface recognition in the type I patient we reported.

Adipose Tissue↗
PubMed1992

Interleukin 6 facilitates corneal epithelial wound closure in vivo.

Rapid corneal epithelial wound healing is essential to the maintenance of clear visual acuity. The cytokine interleukin 6 is thought to participate in the wound-healing process. We investigated the effect of interleukin 6 eye drops on the rate of corneal epithelial wound closure in rabbits in vivo. Recombinant human interleukin 6 in phosphate-buffered saline at concentrations of 0.1, 0.3, or 1 mg/L was administered immediately after the epithelium was débrided with the n-heptyl alcohol treatment and 2, 4, 6, 8, 10, 18, 20, 22, 24, 26, and 28 hours after débridement. The eyes were stained with fluorescein and photographed at baseline and at 7, 10, 18, 21, 24, 27, 30, and 43 hours after débridement. The rate of wound healing was calculated with a linear regression analysis based on the areas of the epithelial defects, which were recorded from hour 10 to hour 30. The mean (+/- SD) healing rate in the control group, which received phosphate-buffered saline alone, was 1.03 +/- 0.15 mm2/h. The administration of interleukin 6 at concentrations of 0.1, 0.3, or 1.0 mg/L increased the healing rate significantly (P less than .001) to 1.27, 1.39, or 1.44 mm2/h, respectively. Our results indicate that the administration of interleukin 6 might have clinical applications in the treatment of persistent corneal epithelial defects.

Alcohols↗
PubMed1992

Erythrocyte membrane transport of glutathione conjugates and oxidized glutathione in the Dubin-Johnson syndrome and in rats with hereditary hyperbilirubinemia.

The Dubin-Johnson syndrome is manifested by conjugated hyperbilirubinemia and pigment accumulation in hepatocellular lysosomes. The TR-rat model is a phenotypic model of the Dubin-Johnson syndrome and is characterized by defective ATP-dependent transport of a group of nonbile acid organic anions, including glutathione-S-conjugates and oxidized glutathione, across the bile canaliculus. Similar ATP-dependent transport mechanisms have been described in erythrocytes. Intact erythrocytes and inverted erythrocyte membrane vesicles from Dubin-Johnson patients, TR-rats and appropriate controls were studied with regard to ATP-dependent transport of dinitrophenyl glutathione and oxidized glutathione. No significant differences were observed, indicating that the erythrocyte and canalicular ATP-dependent transporters for these substrates are functionally and potentially genetically distinct.

Adenosine Triphosphate↗
PubMed1992

Interleukin 6 promotes epithelial migration by a fibronectin-dependent mechanism.

We investigated the effect of interleukin 6 (IL-6) on the migration of rabbit corneal epithelium in vitro and on the attachment of dissociated corneal epithelial cells to a fibronectin matrix. When corneal blocks were cultured with IL-6 for 24 hours, the length of the path of epithelial migration over exposed corneal stroma increased significantly (p less than 0.005 at the concentration of 10 ng/ml) in proportion to the concentrations of IL-6 (0.1-10.0 ng/ml). The addition of antiserum against fibronectin or of GRGDSP abolished the stimulatory effect of IL-6 on epithelial migration. When corneal epithelial cells were cultured with various concentrations of IL-6, suspended, and plated on wells coated with fibronectin (10 micrograms/ml), the number of cells attached to the wells increased in a dose-dependent manner. The presence of antibody against fibronectin or of GRGDSP during the attachment assay decreased the number of cells attached to the fibronectin matrix, regardless of the fact that the cells had been cultured with IL-6 or not. IL-6 stimulated the attachment of corneal epithelial cells to collagen type IV and to laminin matrices. However, the presence of GRGDSP did not affect the cell attachment to collagen type IV and to laminin. These findings strongly indicate that IL-6 stimulates epithelial migration in the cornea by a fibronectin-dependent mechanism, presumably the increased expression of fibronectin receptors.

Amino Acid Sequence↗
PubMed1992

Prophylactic chemotherapy for primary and recurrent superficial bladder cancer: preliminary results. The Hokkaido University Bladder Cancer Collaborating Group.

A multicenter trial for postoperative prophylaxis of the recurrence of superficial Ta-T1, G1-G2 bladder cancer was performed. Eligible patients with primary or recurrent superficial bladder cancer were randomized into four groups. For the primary cases, intravesical instillation of drugs [group A, 20 mg Adriamycin (ADM) + 200 mg cytosine arabinoside (CA) in 30 ml physiological saline; group B, 10 mg peplomycin (PEP) + 200 mg CA in 30 ml physiological saline; group C, 2 mg neocarzinostatin (NCS) + 200 mg CA in 30 ml physiological saline; and group D, control] was carried out once a week for 2 weeks, once every 2 weeks for 14 weeks, once monthly for 8 months, and, finally, once every 3 months for 1 year. For the recurrent cases, intravesical instillation of 20 mg ADM + 200 mg CA in 30 ml physiological saline as described above and daily oral administration of another drug [group E, 300 mg/day UFT; group F, 200 mg 5-fluorouracil (5-FU)/day; group G, 30 mg ubenimex/day; and group H, no oral drug] was performed. The postoperative follow-up period was 3-36 months. A total of 193 primary cases and 121 recurrent cases of superficial bladder cancer were evaluated. The cumulative 12-month nonrecurrence rates for the primary cases were 86.2% in group A, 78.1% in group B, 82.1% in group C, and 68.4% in group D. The cumulative nonrecurrence rate obtained using ADM+CA (group A) was significantly higher than the control value. On the other hand, no significant difference was found in the cumulative nonrecurrence rates calculated for the recurrent cases, regardless of the oral drug given. Intravesical instillation of ADM+CA for primary superficial bladder cancer was considered to be useful, but the long-term effect of intravesical instillation remains to be elucidated. Further refinement of this regimen is necessary for effective prophylaxis of the recurrence of superficial bladder cancer.

Administration, Intravesical↗
PubMed1992

Lymphocyte responses to food antigens in food sensitive patients with allergic tension-fatigue syndrome.

Scores of radioallergosorbent test (RAST) for cow's milk or buckwheat flour and proliferative responses of peripheral blood mononuclear cells (PBMCs) to bovine serum albumin and beta-lactoglobulin or buckwheat flour were measured in cow's milk or buckwheat flour sensitive patients with allergic tension-fatigue syndrome. In all 3 cow's milk sensitive patients with allergic tension-fatigue syndrome, RAST scores for cow's milk were negative or slightly positive, but PBMCs well responded to bovine serum albumin and beta-lactoglobulin, but not to ovalbumin. In a buckwheat flour sensitive patient with allergic tension-fatigue syndrome, RAST scores for buckwheat flour were negative, but PBMCs well responded to buckwheat flour, but not to ovalbumin, bovine serum albumin and beta-lactoglobulin. Conversely, in cow's milk or buckwheat flour sensitive patients with immediate allergic symptoms, RAST scores for offending foods were positive although PBMCs did not respond to offending food antigens. These results suggest that proliferative responses of PBMCs to food antigens are very useful for detection of offending foods in allergic tension-fatigue syndrome.

Adolescent↗
PubMed1992

Rapid and simple gas chromatographic measurement of lactic acid in red blood cells, plasma, and tumor cells after hyperthermia.

The content of lactic acid in red blood cells, plasma, and Ehrlich ascites tumor cells were measured by a gas-liquid chromatography using a column with a terephtalic acid support coated with polyethylene glycol-6000. The lactic acid contents were directly determined in aqueous samples, because they were converted to a volatile derivative in the column. The method was rapid and simple, compared with previous methods which need time-consuming conversion of lactic acid to volatile derivatives. Our measurements showed the increase in the contents of intra- and extracellular lactic acid after hyperthermia.

Animals↗
PubMed1992

Biologically active diterpenes from Aspilia mossambicensis, a chimpanzee medicinal plant.

Two potent stimulators of uterine contraction, the diterpenes kaurenoic and grandiflorenic acids, were isolated from leaves of Aspilia mossambicensis. Their presence supports a hypothesis that wild chimpanzees consume Aspilia species for their pharmacological properties and may explain why female chimpanzees consume Aspilia leaves more frequently than do males. Thiarubrines were not present in any of the leaf samples collected in Mahale or Gombe National Parks, Tanzania, although these antifungal and nematocidal dithianes were found in significant amounts in roots.

Animals↗
PubMed1992

High expression of manganese superoxide dismutase in 7,12-dimethylbenz[a]anthracene-induced ovarian cancer and increased serum levels in the tumor-bearing rats.

Manganese superoxide dismutase (Mn-SOD) is strongly expressed in human ovarian cancer, and the serum level of the enzyme is a useful marker for the diagnosis and monitoring of human ovarian cancer. In the present study we found that Mn-SOD was highly expressed in primary and transplanted ovarian cancers in rats induced by 7,12-dimethylbenz[a]anthracene (DMBA), as judged by enzyme-linked immunosorbent assay as well as by Northern blot analysis. The serum levels of Mn-SOD in the tumor-bearing rats were also higher than those in control rats. The antibody strongly reacted with rat ovarian carcinoma tissues. These data suggest that DMBA-induced ovarian cancer in rats is a good experimental model for human ovarian cancer, and that Mn-SOD is also a good marker for disease in the animal model.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1992

ATP-dependent organic anion transport system in normal and TR- rat liver canalicular membranes.

Many non-bile acid organic anions enter hepatocytes, where they are converted into polar conjugates and preferentially secreted into bile. ATP-dependent and membrane potential-dependent transport of non-bile acid organic anions across the plasma membrane of rat hepatocytes was studied in canalicular (CMV) or sinusoidal membrane vesicles (SMV) using sulfobromophthalein (BSP), a representative non-bile acid organic anion. Temperature-dependent, osmotically sensitive, saturable, ATP-dependent, and unidirectional (inside to outside) BSP transport was observed in CMV but not in SMV. Apparent Michaelis constants for ATP and BSP were 0.26 mM and 31 microM, respectively. ATP-dependent BSP transport was inhibited by oxidized glutathione, dinitrophenyl-glutathione (GSDNP), BSP glutathione, and bilirubin diglucuronide but not by daunomycin, taurocholate, and reduced glutathione. Inhibition by GSDNP and bilirubin diglucuronide was competitive, with apparent inhibitor constants of 41 and 4.2 microM, respectively. CMV from normal rats demonstrated ATP-dependent and membrane potential-dependent BSP transport that was additive. CMV from TR- rats lacked ATP-dependent BSP transport but retained membrane potential-dependent transport of non-bile acid organic anions as well as ATP-dependent transport mechanisms for organic cations (i.e., daunomycin) and bile acids (i.e., taurocholate).

Adenosine Triphosphate↗
PubMed1992

Two distinct mechanisms for bilirubin glucuronide transport by rat bile canalicular membrane vesicles. Demonstration of defective ATP-dependent transport in rats (TR-) with inherited conjugated hyperbilirubinemia.

Bilirubin is conjugated with glucuronic acid in hepatocytes and subsequently secreted in bile. The major conjugate is bilirubin diglucuronide. Using sealed vesicles which are primarily derived from the canalicular (CMV) and sinusoidal (SMV) membrane vesicle domains of the plasma membrane of hepatocytes, we demonstrated that bilirubin glucuronides are transported by CMV by both ATP- and membrane potential-dependent transport systems. In CMV from normal rats, these processes are additive. In CMV from TR- rats, which have an autosomal recessively inherited defect in biliary secretion of nonbile acid organic anions, ATP-dependent transport of bilirubin diglucuronide was absent whereas the membrane potential driven system was retained. Other canalicular ATP-dependent transport systems, which were previously described for organic cations and bile acids, are functionally retained in TR- rats. Our study indicates that bilirubin glucuronides are primarily secreted into the bile canaliculus by an ATP-dependent mechanism which is defective in an animal model of the human Dubin-Johnson syndrome.

Adenosine Triphosphate↗
PubMed1992

Cardiac musculature of the intrapulmonary vein in the musk shrew.

The cardiac musculature of intrapulmonary veins was examined to elucidate its distribution pattern in the musk shrew, the primitive mammalian type, using by both light and electron microscopies. The musculature was distributed extensively from the hilum to the small veins less than 50 microns in diameter, suggesting that the phylogenic origin of this musculature may be traceable to the primitive mammalian types. Ultrastructure of cardiac myocyte in the intrapulmonary venous walls was essentially similar to that of left atrial myocyte. This suggests that the cardiac musculature may contribute to the regulation of pulmonary blood circulation. The abundance of large lipid droplets in both atrial and pulmonary myocytes was also observed and seemed to be the characteristic ultrastructure related to the physiological condition in this animal.

Animals↗
PubMed1992

Cardiac musculature of the cranial and caudal venae cavae and the pulmonary vein in the fowl.

The cardiac musculature of cranial and caudal venae cavae and pulmonary vein was examined to clarify its distribution pattern in the fowl using both light and electron microscopies. The musculature was distributed from the heart to the root of subclavian vein in the cranial vena cava, to the cranial margin of the liver in the caudal vena cava, and to the left and right distal pulmonary veins in the pulmonary vein, respectively. Judging from the morphology and distribution pattern in the venous wall, the cardiac musculature in the fowl is thought to share the same phylogenic origin with that in mammals. The ultrastructure of cardiac myocytes including transitional cells in the cranial vena cava and the pulmonary vein resembled that of atrial myocytes. While, the typical specialized myocytes such as Purkinje fiber were found in the caudal vena cava of the fowl.

Animals↗
PubMed1992

Fine structure of the parotid gland in the crest-tailed marsupial-rat (Dasyuroides byrnei).

The parotid gland of Dasyuroides byrnei was examined by light microscopy, and transmission and scanning electron microscopy. The acini were composed predominantly of seromucous cells with a few mucous cells. The seromucous cells were light or dark cells containing acidophilic spherical granules of moderate to high electron density and had well-developed cytoplasmic organelles-ordinary mitochondria and large mitochondria with tubular cristae, RER with vesicular or tubular elements, and Golgi apparatus with lamellae, vesicles and vacuoles. The mucous cells had basophilic amorphous granules of low electron density, like those of ordinary mucous cells. The intercalated ducts were composed of simple cuboidal light cells having a few electron-dense granules. The striated ducts consisted of tall columnar light cells containing numerous vesicles and mitochondria with tubular cristae, the same as found in acinar seromucous cells.

Animals↗