Search PubMed⌕ Search

Biomedical subjects

H Miyoshi

Publications and source records attributed to H Miyoshi.

At least 127 records · Page 7Linked to original sources
PubMed1998

Drug eruption (erythema multiforme type) due to a digestive enzyme drug.

An 84-year-old Japanese male had pruritic indurated erythema on his upper limb and left lower abdomen, which had developed abruptly two months before visiting our hospital. Hematological examination showed eosinophilia, 550/mm3. Histopathological findings were suggestive of erythema multiforme in response to a drug. By means of patch tests and a p.o. challenge test, Aczym, a digestive enzyme drug, was shown to be the cause of his condition. Further study revealed that the specific ingredients involved were pancreatin and Taka-diastase. An eruption resulting from ingestion of a digestive enzyme drug has not previously been reported.

Aged↗
PubMed1998

Development of a self-inactivating lentivirus vector.

We have constructed a new series of lentivirus vectors based on human immunodeficiency virus type 1 (HIV-1) that can transduce nondividing cells. The U3 region of the 5' long terminal repeat (LTR) in vector constructs was replaced with the cytomegalovirus (CMV) promoter, resulting in Tat-independent transcription but still maintaining high levels of expression. A self-inactivating (SIN) vector was constructed by deleting 133 bp in the U3 region of the 3' LTR, including the TATA box and binding sites for transcription factors Sp1 and NF-kappaB. The deletion is transferred to the 5' LTR after reverse transcription and integration in infected cells, resulting in the transcriptional inactivation of the LTR in the proviruses. SIN viruses can be generated with no significant decreases in titer. Injection of viruses into the rat brain showed that a SIN vector containing the green fluorescent protein gene under the control of the internal CMV promoter transduced neurons as efficiently as a wild-type vector. Interestingly, a wild-type vector without an internal promoter also successfully transduced neurons in the brain, indicating that the HIV-1 LTR promoter is transcriptionally active in neurons even in the absence of Tat. Furthermore, injection of viruses into the subretinal space of the rat eye showed that wild-type vector transduced predominantly retinal pigment epithelium and photoreceptor cells, while SIN vector was able to transduce other types of retinal cells, including bipolar, Müller, horizontal, and amacrine cells. This finding suggests that the HIV-1 LTR can negatively influence the internal CMV promoter in some cell types. SIN HIV vectors should be safer for gene therapy, and they also have broader applicability as a means of high-level gene transfer and expression in nondividing cells.

Animals↗
PubMed1998

Hepatocyte culture utilizing porous polyvinyl formal resin maintains long-term stable albumin secretion activity.

To investigate the effects of culture conditions on the maintenance of metabolic functions of cultured hepatocytes, long-term hepatocyte culture lasting 20 days was performed under two different culture conditions, i.e. stationary cultures utilizing porous polymer (polyvinyl formal (PVF) resin) as a substratum and conventional monolayer dish cultures without PVF. Metabolic activities specific to hepatocytes were evaluated in terms of ammonia metabolism, urea synthesis, and albumin secretion. Concerning ammonia metabolic and urea synthetic activities, no significant differences in maintenance of these activities were found between the two culture conditions, and these activities rapidly decreased with the elapse of the culture period, especially during the early stage of the experiments. However, after day 10, these activities in the stationary cultures were maintained at a slightly more favorable level than in the monolayer cultures. On the other hand, compared with ammonia metabolism and urea synthesis, stable and well-maintained albumin secretion of hepatocytes (60% of the activity in day 1) was exhibited in the stationary culture experiments, despite that this particular activity under the monolayer culture condition gradually reduced to a very low level (5.7% of that on day 1) at the end of the culture. From the morphological observations, hepatocytes immobilized in the PVF resin revealed individual spherical shapes without forming multicellular aggregation, and it was suggested that this characteristic structure contributed to good albumin secretion of hepatocytes. In conclusion, the advantages of the hepatocyte culture technique utilizing PVF resin over the conventional dish culture in maintaining some representative metabolic function specific to hepatocytes were clarified.

Albumins↗
PubMed1998

Cdk2/cdc2 expression in colon carcinogenesis and effects of cdk2/cdc2 inhibitor in colon cancer cells.

Cyclin dependent kinases propel the cell cycle in collaboration with cyclins. We have examined the expression of cdk2/cdc2 in adenoma and focal carcinoma in adenomatous tissue to explore their role in tumorigenesis of colorectum. Immunohistochemical study revealed that cdk2/cdc2 was overexpressed in a subsets of adenoma (14/50; 28.0%) but this overexpression was much more obvious in focal carcinoma (13/15; 86.7%). These results suggest that cdk2/cdc2 is remarkably upregulated together with a malignant change. In an effort to demonstrate a significant role for cdk2/cdc2 in colon cancer, we investigated growth and apoptosis with butyrolactone I, a specific inhibitor for cdk2/cdc2, using 4 colon carcinoma cell lines (HCT116, LoVo, HT29, Colo 320DM). Butyrolactone I inhibited proliferation of all colon carcinoma cell lines at 100 microM and it induced apoptosis in LoVo cell line with induction of p53. Our findings suggest that inhibition of cdk2/cdc2 may be a useful strategy against colon cancer.

4-Butyrolactone↗
PubMed1998

[Diagnosis of the wall-thickened lesions of the gallbladder with dynamic MRI].

We studied 32 patients with the thickened lesions of the wall of the gallbladder by using dynamic MRI. We tried the differential diagnosis of gallbladder lesions according to the time intensity curve (TIC) and enhanced pattern. TIC of carcinoma was elevated more seeply from plain to arterial phase than the inflammatory diseases. The Inflammatory diseases were keeping three-layer structures of the wall of the gallbladder, but gallbladder carcinoma destroys the wall-structure. We could diagnose as direct liver invasion of the carcinoma clearly. We could exactly diagnose adenomyomatosis in dynamic MRI by small low intensity spots within the wall of the gallbladder. In the patients with gall stones, the wall of the gallbladder were more clearly observed in dynamic MRI compared with US and EUS.

Carcinoma, Adenosquamous↗
PubMed1997

Stable and efficient gene transfer into the retina using an HIV-based lentiviral vector.

The development of methods for efficient gene transfer to terminally differentiated retinal cells is important to study the function of the retina as well as for gene therapy of retinal diseases. We have developed a lentiviral vector system based on the HIV that can transduce terminally differentiated neurons of the brain in vivo. In this study, we have evaluated the ability of HIV vectors to transfer genes into retinal cells. An HIV vector containing a gene encoding the green fluorescent protein (GFP) was injected into the subretinal space of rat eyes. The GFP gene under the control of the cytomegalovirus promoter was efficiently expressed in both photoreceptor cells and retinal pigment epithelium. However, the use of the rhodopsin promoter resulted in expression predominantly in photoreceptor cells. Most successfully transduced eyes showed that photoreceptor cells in >80% of the area of whole retina expressed the GFP. The GFP expression persisted for at least 12 weeks with no apparent decrease. The efficient gene transfer into photoreceptor cells by HIV vectors will be useful for gene therapy of retinal diseases such as retinitis pigmentosa.

Animals↗
PubMed1997

Size Determination of Catena-&mgr;-2,5-dihydroxy-p-benzoquinonatonickel(II) Coordination Polymer Colloid and Its Photochemical Reaction

Electric birefringence and streaming dichroism measurements of catena-&mgr;-2,5-dihydroxy-p-benzoquinonatonickel(II) [dhqNi(II)] aqua sol suggested that the average length of the sol particles was ca. 380 nm and the axial ratio was 2.0-2.3 as the prolate spheroid. The average particle length in the scanning microscopic images was 370 ± 60 nm and the axial ratio 2.3 ± 0.6. This aqua colloid was decomposed by UV irradiation under an O2 gas atmosphere, but under a N2 gas atmosphere its decomposition was depressed. Furthermore, addition of sacrificial reagents such as l-ascorbic acid depressed the decomposition. These facts suggested that the photogenerated electron originating from the irradiated dhqNi(II) colloidal particle reduced O2, while the positive hole on the colloid oxidized dhqNi(II) itself. It was found that the reduction product from O2 reduced Cr6+ (in Cr2O72-) to Cr3+, and the oxidized dhqNi(II) oxidized I- to I2/2. Therefore, H2O2 formation was proposed as the photochemical reduction product. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Identification of mu-, m-calpains and calpastatin and capture of mu-calpain activation in endothelial cells.

The presence of the calpain-calpastatin system in human umbilical vein endothelial cells (HUVEC) was investigated by means of ion exchange chromatography, Western blot analysis, and Northern blot analysis. On DEAE anion exchange chromatography, calpain and calpastatin activities were eluted at approximately 0.30 M and 0.15-0.25 M NaCl, respectively. For half-maximal activity, the protease required 800 microM Ca2+, comparable to the Ca2+ requirement of m-calpain. By Western blot analysis, the large subunit of mu-calpain (80 kDa) was found to be eluted with calpastatin (110 kDa). Both the large subunit of m-calpain (80 kDa) and calpastatin were detected in the respective active fractions. By Northern blot analysis, mRNAs for large subunits of mu- and m-calpains were detected in single bands, each corresponding to approximately 3.5 Kb. Calpastatin mRNA was observed in two bands corresponding to approximately 3.8 and 2.6 Kb. Furthermore, the activation of mu-calpain in HUVEC by a calcium ionophore was examined, using an antibody specifically recognizing an autolytic intermediate form of mu-calpain large subunit (78 kDa). Both talin and filamin of HUVEC were proteolyzed in a calcium-dependent manner, and the reactions were inhibited by calpeptin, a cell-permeable calpain specific inhibitor. Proteolysis of the cytoskeleton was preceded by the appearance of the autolytic intermediate form of mu-calpain, while the fully autolyzed postautolysis form of mu-calpain (76 kDa) remained below detectable levels at all time points examined. These results indicate that the calpain-calpastatin system is present in human endothelial cells and that mu-calpain may be involved in endothelial cell function mediated by Ca2+ via the limited proteolysis of various proteins.

Antibody Specificity↗
PubMed1997

Probing the ubiquinone reduction site of mitochondrial complex I using novel cationic inhibitors.

A wide variety of N-methylpyridinium and quinolinium cationic inhibitors of mitochondrial complex I was synthesized to develop potent and specific inhibitors acting selectively at one of the two proposed ubiquinone binding sites of this enzyme (Gluck, M. R., Krueger, M. J., Ramsay, R. R., Sablin, S. O., Singer, T. P., and Nicklas, W. J. (1994) J. Biol. Chem. 269, 3167-3174). N-Methyl-2-n-dodecyl-3-methylquinolinium (MQ18) inhibited electron transfer of complex I at under microM order regardless of whether exogenous or endogenous ubiquinone was used as an electron acceptor. The presence of tetraphenylboron (TPB-) potentiated the inhibition by MQ18 in a different way depending upon the molar ratio of TPB- to MQ18. In the presence of a catalytic amount of TPB-, the inhibitory potency of MQ18 was remarkably enhanced, and the extent of inhibition was almost complete. The presence of equimolar TPB- partially reactivated the enzyme activity, and the inhibition was saturated at an incomplete level (approximately 50%). These results are explained by the proposed dual binding sites model for ubiquinone (cited above). The inhibition behavior of MQ18 for proton pumping activity was similar to that for electron transfer activity. The good correlation of the inhibition behavior for the two activities indicates that both ubiquinone binding sites contribute to redox-driven proton pumping. On the other hand, N-methyl-4-[2-methyl-3-(p-tert-butylphenyl)]propylpyridinium (MP6) without TPB- brought about approximately 50% inhibition at 5 microM, but the inhibition reached a plateau at this level over a wide range of concentrations. Almost complete inhibition was readily obtained at low concentrations of MP6 in the presence of TPB-. Thus MP6 appears to be a selective inhibitor of one of the two ubiquinone binding sites. With a combined use of MP6 and 2,3-diethoxy-5-methyl-6-geranyl-1,4-benzoquinone, we also provided kinetic evidence for the existence of two ubiquinone binding sites.

1-Methyl-4-phenylpyridinium↗
PubMed1997

Prostacyclin analog-suppressed ischemia-reperfusion injury of the rat liver: evaluation by calpain mu activation.

Prostaglandin I2 has a protective effect on hepatic ischemia-reperfusion injury. However, the exact intracellular mechanisms of this effect have not been elucidated. Calpain micro, a Ca2+-dependent protease, has been found to play a role in the ischemia-reperfusion injury of various organs. The hilar area of the left lateral and median lobes of rat livers was clamped for 60 min. A prostaglandin I2 analog (OP2507, C35H41NO4) was intravenously administered at 0.1, 0.32, or 1.0 microg/kg/min from 20 min before the ischemia. In addition to biochemical and microscopic analyses, the activation of calpain mu was investigated using specific antibodies against the intermediate (activated) and preactivated forms of calpain mu. The degradation of talin was also studied by Western blotting. When OP2507 was infused at 0.32 and 1.0 microg/kg/min, bile flow significantly increased after reperfusion compared with the control group, consistent with the decrease in serum transaminase levels. Membrane bleb formation and the appearance of the intermediate form of calpain mu were observed at 60 min of ischemia in the control and OP2507 (0.1 microg/kg/min) groups and remained present until 120 min after reperfusion. OP2507 (1.0 microg/kg/min) markedly suppressed not only membrane bleb formation but also calpain mu activation and the degradation of talin. In conclusion, OP2507 suppresses ischemia-reperfusion injury of the rat liver, and its cytoprotective effect is closely associated with the inhibition of calpain mu activation.

Alanine Transaminase↗
PubMed1997

Chromosomal mapping and developmental study of Tattered-Hokkaido (Tdho).

We found a new X-linked dominant mouse mutation. This mouse has the same phenotype as Td, which exhibits hyperkeratotic skin, reduced viability in affected females, a tendency to be smaller, lighter weight than the normal sibs during weaning age, and prenatal lethality in affected males. To map the locus, we tested 267 progeny from an intraspecific backcross between affected females and wild-origin strain males. Polymerase chain reaction (PCR) was performed with microsatellite markers of the proximal region of the mouse X Chromosome (Chr). This mutant showed no recombination with DXMit 123, DXMit 55, or DXMit 26. The gene position and phenotype of this mutant were very similar to those of Td. Therefore, it is speculated that the new mutant gene is a multiple allele of Td, and we designated it Tattered-Hokkaido (Tdho). Linkage analysis of these animals suggested a possible gene order of cen-(Tdho, DXMit123, DXMit55, DXMit26)-DXMit161-DXMit54-DXMit103-DXMit52 -DXMit190-DXMit138) in the X Chr. Prenatal lethality of male mutants was also investigated, with 12.5 to 16.5 embryonic day (E) backcrossed embryos from affected F1 females. It was found that the male mutants died between E12.5 and E14.5. The cause of death of male mutants is discussed in relation with the other proximal genes of the X Chr.

Animals↗
PubMed1997

Efficacy of prophylactic sclerotherapy in patients with hepatocellular carcinoma and varices negative for the red color sign.

BACKGROUND: A prospective randomized controlled study was performed to evaluate the usefulness of prophylactic endoscopic sclerotherapy in patients with hepatocellular carcinoma complicated by esophageal varices. METHODS: The subjects included 58 patients with esophageal varices negative for the red color sign and hepatocellular carcinoma without tumor emboli in the portal trunk or primary portal branches. Patients were randomly assigned to prophylactic sclerotherapy (n = 29) or control (n = 29) groups, and their bleeding and survival rates were compared. RESULTS: A mean of 3.0 sclerotherapy sessions was required for complete disappearance of varices in patients receiving prophylactic sclerotherapy. During the observation period, transcatheter arterial embolization for hepatocellular carcinoma was performed more often in patients with prophylactic sclerotherapy (mean 3.8 times) than in control patients (mean 2.0 times) (p < .05). Percutaneous ethanol injection therapy was performed more often in patients with prophylactic sclerotherapy than in controls (mean 8.1 times vs 5.0 times, respectively) (p < .05). The 3-year bleeding rates were 50% for the control group and 18% for the prophylactic sclerotherapy group (p < 0.05), and the 3-year survival rates were 16% for the control group and 37% for the therapy group (p < 0.05). CONCLUSIONS: Prophylactic sclerotherapy improves survival in patients with hepatocellular carcinoma complicated by red color sign-negative esophageal varices without tumor emboli in the portal trunk or primary portal branches.

Adult↗
PubMed1997

Estrogen inhibits cuff-induced intimal thickening of rat femoral artery: effects on migration and proliferation of vascular smooth muscle cells.

The present study was performed to elucidate the mechanism underlying the anti-atherogenic action of estrogen. We investigated the effect of estrogen on intimal thickening of the rat femoral artery induced by cuff placement and further examined the effect of estrogen on migration and proliferation of vascular smooth muscle cells (VSMCs) in culture. Intimal thickening was significantly greater in males than in control females. Intimal thickening in females was increased to the level in males by ovariectomy. Estrogen replacement to ovariectomized rats reversed this effect. Proliferating cell nuclear antigen immunohistochemistry showed that in vivo proliferation of VSMCs contributed to the difference in intimal thickening. There was no difference in blood pressure and serum lipids, suggesting that estrogen directly acted on artery and inhibited intimal thickening. 17 beta-Estradiol (E2, 1-100 nmol/l) inhibited migration of cultured rat VSMCs, assayed using a microchemotaxis chamber, in a concentration-dependent manner. E2 (0.01-100 nmol/l), but not progesterone or testosterone, also inhibited [3H]thymidine incorporation in rat VSMCs in a concentration-dependent manner. Indomethacin, NG-monomethyl-L-arginine and methylene blue did not influence the inhibitory action of E2 on [3H]thymidine incorporation, suggesting that prostanoids and nitric oxide are not involved in the action of E2. E2 did not provoke VSMC injury, as measured by the release of incorporated [3H]2-deoxy-D-glucose. These results suggest that the inhibition of migration and proliferation of VSMCs contributes to the inhibitory effect of estrogen on intimal thickening.

Animals↗