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Biomedical subjects

T Miyagi

Publications and source records attributed to T Miyagi.

At least 109 records · Page 6Linked to original sources
PubMed1990

Biochemical and immunological studies on two distinct ganglioside-hydrolyzing sialidases from the particulate fraction of rat brain.

Ganglioside-hydrolyzing sialidase activity was solubilized from rat brain particulate fraction by using Triton X-100 plus sodium deoxycholate. When chromatographed on AH-Sepharose 4B, the solubilized activity was resolved into two peaks, which were designated sialidases I and II in order of elution. The two sialidases were purified by using sequential chromatographies on Octyl-Sepharose CL-4B, Phenyl-Sepharose CL-4B, and Sephadex G-200. Sialidase II was purified further by Mono Q-FPLC. Overall purification was 450- and 2,150-fold, for sialidases I and II, respectively. Purified sialidases I and II were maximally active at near pH 5.0 and exhibited M = 70,000 by gel filtration. Sialidase I hydrolyzed gangliosides but scarcely other substrates including 4-methylumbelliferyl-NeuAc (4MU-NeuAc). Sialidase II hydrolyzed oligosaccharides, glycoproteins, and 4MU-NeuAc although gangliosides appeared to be preferential substrates. Sialidase II cleaved GM2 much faster than sialidase I. An antibody raised in rabbits against sialidase I reacted with only sialidase I and an antibody against sialidase II reacted with only sialidase II. A subcellular distribution study suggested sialidase I in the synaptosomal membrane and sialidase II in the synaptosomal and lysosomal membranes, and this was verified by using the above antibodies.

Animals↗
PubMed1990

Immunological discrimination of intralysosomal, cytosolic, and two membrane sialidases present in rat tissues.

Cytosolic sialidase was purified from rat skeletal muscle, and the purified enzyme migrated as a single band of Mr 43,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A polyclonal antibody raised against the enzyme inhibited and immunoprecipitated rat liver cytosolic sialidase as well as the muscle enzyme but failed to cross-react with the intralysosomal sialidase of rat liver and membrane sialidases I (synaptosomal) and II (lysosomal) of rat brain. The antibody against brain membrane sialidase I (anti-I) and that against sialidase II (anti-II), which could be useful to discriminate the two enzymes, did not cross-react with the intralysosomal and cytosolic sialidases of liver. Although more than 90% of liver plasma membrane sialidase was immunoprecipitated with anti-I, only 60% of liver lysosomal membrane sialidase was immunoprecipitated with anti-II, the remainder being immunoprecipitated with anti-I. In confirmation of these data, liver lysosomal membrane exhibited two peaks of ganglioside sialidase corresponding to the membrane sialidases I and II on Aminohexyl-Sepharose chromatography while only one peak of ganglioside sialidase corresponding to sialidase I was observed for liver plasma membrane. These results indicate that the four types of rat sialidase are proteins distinct from one another and that the three kinds of antisera described above are useful for discriminating these sialidases qualitatively and probably quantitatively.

Animals↗
PubMed1990

Neoplastic alteration of a membrane-associated sialidase of rat liver.

Rat liver particulate fraction contains two types of membrane-associated and gangliosides-hydrolyzing sialidase, which have been shown to be identical to two membrane-associated sialidases of rat brain (I and II) chromatographically, immunologically and in substrate specificity. Chromatography on AH-Sepharose 4B of the membrane sialidases of rat primary hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (MeDAB) further revealed that hepatocarcinogenesis induces a marked decrease in sialidase II but no decrease in sialidase I. Using antisera against sialidases I and II of rat brain, immunoprecipitation studies of the solubilized particulate fractions of rat liver and MeDAB-hepatoma gave results similar to those obtained chromatographically. Using the same immunological technique, sialidase II but not sialidase I was found to be decreased in AH109 A hepatoma and in regenerating and fetal liver.

Animals↗
PubMed1990

Tumor-promoting phorbol ester induces alterations of sialidase and sialyltransferase activities of JB6 cells.

Sialidase and sialyltransferase activities were studied in JB6 mouse epidermal cells before and after exposure to phorbol ester, 12-O-tetradecanoyl phorbol-13-acetate (TPA), which irreversibly induces anchorage-independent growth and tumorigenicity. JB6 cells exhibited sialidase activities toward 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid (4MU-NeuAc) and gangliosides at pH 4.5 in the particulate fraction but apparently not in the cytosol at pH 4.5 or 6.0. In JB6 cells exposed to TPA and in the anchorage-independent transformants, the sialidase activity toward 4MU-NeuAc was decreased and the activity toward gangliosides was increased compared with those in untreated JB6 cells. Immunological analysis with antisera against membrane-associated sialidases I and II revealed that plasma membrane-associated sialidase I was increased and lysosomal membrane-associated sialidase II was decreased under these conditions. TPA treatment also affected the sialyltransferase activities of JB6 cells: and elevation of the transfer activities toward asialo-orosomucoid and asialo-porcine submaxillary mucin but a reduction of GM3 and GD3 synthase activities were observed on exposure to TPA and in cells transformed by TPA to retain anchorage-independency. These results suggest that an increase in sialic acid bound to glycoproteins and a decrease in that bound to glycolipids may occur in JB6 cells exposed to TPA and in the anchorage-independent transformants.

Animals↗
PubMed1990

Effects of OK-432 activation on the sialidase activities of rat peritoneal macrophages.

Intraperitoneal treatment of rat peritoneal macrophages with OK-432 results in more than 9-fold increase in the activity of ganglioside sialidase, which seems to coincide with the appearance of a cell surface antigen, asialo-GM1. The results of subsequent studies suggest that the ganglioside sialidase is located in the plasma membrane, where the enzyme may be responsible for the formation of asialo-GM1 from GM1. In the macrophages activated with OK-432, sialidase activity toward 4-methylumbelliferyl-N-acetylneuraminic acid (4MU-NeuAc) is also increased. It appears that the 4MU-NeuAc sialidase is intralysosomal and is increased together with other acid hydrolases present in the lysosomes.

Animals↗
PubMed1990

[Prophylactic effect of UFT on the recurrence of bladder cancer].

To evaluate the effect of UFT, a mixture of ftorafur and uracil in a ratio of 1:4, in preventing postoperative recurrence of bladder cancer, we performed a randomized controlled study with a non-medication group as control. UFT was given orally 400 mg a day for 6 months. Of 111 patients, 56 were given UFT and 55 were followed up without any medication. The non-recurrence rate in the group treated with UFT was 62.8% after 1 year and 36.3% after 2 years of follow up, and that of the control group was 45.7% and 39.5%, respectively. The rate of non-recurrence in the UFT group was significantly higher (p less than 0.05) than that of the control group during the period of follow up for 2 years. The incidence of side effects was 6.8% in UFT patients. These results indicate the clinical usefulness of prophylactic administration of UFT for bladder cancer patients.

Administration, Oral↗
PubMed1990

[Clinical observation on renal pelvic and ureteral tumors].

During the 18 years from October, 1971 to September, 1989, 40 patients with renal pelvic and ureteral tumors were treated at our Department of Urology. Thirty were male and 10 female, and were between 44 and 83 years old with a mean age of 65.5 years. Histopathologically, there were 38 transitional cell carcinomas and 2 squamous cell carcinomas. There was a positive correlation between grade and stage of tumor. Among the patients with transitional cell carcinoma, the five-year survival rate was 54.4% for all the patients, 57.1% for patients with renal pelvic tumors and 48.4% for those with ureteral tumors respectively, as measured by the Kaplan-Meier's method. Stage and intravascular invasion of the tumor were the most influential factors for prognosis. There was no evidence in this series to show the usefulness of postoperative adjuvant chemotherapy, such as bladder instillation or peroral administration of various anti-tumor drugs, as a prophylactic use for recurrence of the bladder tumor in low stage cases.

Adult↗
PubMed1989

Direct and serial transplantation of Ph1-positive acute lymphoblastic leukemia into nude mice.

A new Philadelphia chromosome (Ph1-positive) acute lymphoblastic leukemia (ALL) cell line was established in nude mice by direct and serial transplantation of peripheral blood leukemia cells from an adult patient. Although the patient's leukemia cells did not grow in vitro, they were successfully transplanted for 8 serial passages, giving rise to progressive growth of tumors with frequent involvement of lymph nodes, liver, spleen, bone marrow, and meninges. The tumor cells could also be passaged in an ascites form. This in vivo cell line, designated PALL-I, retained the Ph1 chromosome, t(9;22) (q34;q11), and pre-B-cell phenotype (SmIg-, CpIg-, CD10+, CD19+, OKIaI+, and CD38+), like the original leukemia cells. Molecular genetic analysis of PALL-I cells revealed neither bcr rearrangement nor 8.5-kb abI-related mRNA that is characteristically seen in Ph1-positive chronic myelogenous leukemia (CML). Thus, the PALL-I cell line is genetically distinct from CML. It may provide a useful model for an understanding of the cellular and molecular biology of Ph1-positive ALL without classical bcr rearrangement.

Acute Disease↗
PubMed1989

[Seizure and tremor occurring in acute leukemia patients treated with imipenem/cilastatin].

We report here four patients with acute leukemia, who developed seizure or tremor following treatment with imipenem, a new broad-spectrum antibiotic. All four patients had no renal dysfunction and recovered after discontinuation of the drug. Two patients who developed seizure had a past history of cerebral hemorrhage with symptoms of meningitis in one and the other had received frequent intrathecal injections of methotrexate. Seizure also occurred in another patient who was given multiple intrathecal injections of methotrexate. The remaining old patient developed tremor after the first administration of imipenem which did not progress to convulsion. Cerebral hemorrhage or meningitis is known to predispose patients for convulsion following imipenem treatment. In addition, the present study suggests that central nervous system damage related with intrathecal injections of methotrexate may be a predisposing factor. Thus, imipenem should be given with caution to acute leukemia patients who often have risk factors for developing imipenem-related complications.

Acute Disease↗
PubMed1988

Trisomy 4 in a case of acute nonlymphocytic leukemia (M2).

Trisomy 4 in a Japanese patient with type M2 acute nonlymphocytic leukemia is reported. Karyotypic analysis was unsuccessful at diagnosis and complete remission lasted 4 years. The cytogenetic change was detected in the first and second relapses as the only chromosome abnormality. Unusual nuclear irregularities were found in many leukemic cells.

Acute Disease↗
PubMed1988

Membrane-associated sialidase of rat liver and its decrease in hepatomas.

Using the particulate fraction of tissue homogenate, plasma membrane-associated sialidase was assayed at pH 4.5 with bovine brain mixed gangliosides as the substrate. The activity was lower in rat hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (MeDAB) and transplantable AH-109A rat hepatoma than in normal rat liver. The enzyme was almost quantitatively solubilized from liver particulate fraction by using 0.5% (w/v) sodium deoxycholate plus 0.2% (w/v) Triton X-100. When chromatographed on DEAE-cellulose, the solubilized activity emerged as a single peak. The enzyme thus obtained was maximally active at pH 4.5, and readily hydrolyzed mixed gangliosides but was less active toward 4-methylumbelliferyl-alpha-N-acetylneuraminic acid, 3'-sialyllactose and fetuin. The corresponding enzyme from MeDAB-induced hepatoma was indistinguishable from the liver enzyme in terms of ease of solubilization, pH-activity relationship, chromatographic behavior and substrate preference. It therefore appears that the plasma membrane-associated sialidase of hepatomas differs from that of liver only in the tissue level of activity.

Animals↗
PubMed1988

Comparative study of the levels of sialyltransferases responsible for the formation of sugar chains in glycoproteins and gangliosides in rat liver and hepatomas.

Sialyltransferases responsible for the formation of sugar chains in glycoproteins were studied in rat hepatoma in comparison with rat liver. Hepatoma induced by feeding Wistar rats with 3'-methyl-4-dimethylaminoazobenzene (MeDAB) was more active than Wistar liver in sialylating asialo-orosomucoid, and this was due to an increased activity of Gal(beta 1----4)GlcNAc (alpha 2----6) sialyltransferase, the major sialyltransferase in these tissues. Gal(beta 1----3,4)GlcNAc (alpha 2----3) sialyltransferase and the sialyltransferase acting on asialo-bovine submaxillary mucin were, however, decreased in the hepatoma. A similar pattern of sialyltransferase alterations was observed in regenerating liver and other tumors such as AH-109A hepatoma and Sato lung cancer, both of which had been inoculated into Donryu rats. In contrast to these sialyltransferases, the activities of the sialyltransferases responsible for the formation of gangliosides were markedly different even between Wistar and Donryu livers. When compared with Wistar liver, MeDAB-induced hepatoma was higher in lactosylceramide- and lower in GM3-sialyltransferase activity, but these two activities were both lower in AH-109A compared with Donryu liver.

Animals↗
PubMed1987

[A new treatment of simple renal cyst: percutaneous instillation of minocycline hydrochloride into simple renal cyst].

Minocycline hydrochloride was percutaneously instilled into simple renal cysts to prevent recurrence of renal cysts after the puncture and aspiration of cystic fluid. Fifty-six simple renal cysts in 51 patients were punctured with an 18-gauge needle under ultrasonographic guidance, and the cystic fluid was aspirated under fluoroscopic control. A single 100 mg or 200 mg dose of minocycline hydrochloride dissolved in 5 ml of distilled water was instilled through the needle into the renal cyst. The patients were followed up by computed tomographic (CT) scan and ultrasonography 1, 3, 6 and 12 months after the treatment. Efficacy was evaluated after 3 months or longer. Of 20 renal cysts instilled with 100 mg of minocycline, efficacy was excellent in 10, good in 6 and poor in 4. Of 22 renal cysts instilled with 200 mg of minocycline, efficacy was excellent in 10, good in 9 and poor in 3. No significant difference was noted between the efficacy rate of 100 mg and 200 mg treatments. Complications attributable to treatment were observed in 15 patients: moderate pain in one, slight pain in 6, slight fever in 8 and slight hematuria in one. Neither severe adverse reactions nor infections were observed in any of the patients. These results suggest that the percutaneous instillation of minocycline into simple renal cysts is a new, simple, safe and effective treatment to prevent recurrence of the cyst and additionally to prevent infection following the puncture.

Administration, Cutaneous↗
PubMed1986

Evidence for sialidase hydrolyzing gangliosides GM2 and GM1 in rat liver plasma membrane.

Rat liver plasma membrane removed sialic acid from mixed bovine brain gangliosides more efficiently than from sialyllactose and orosomucoid with an optimal pH of 4.5. When individual gangliosides, each labeled with [14C]sialic acid or [3H]sphingosine, were tested, not only GD1a and GM3 but also GM2 and GM1, both of which had been considered to resist mammalian sialidases, were desialylated. The products of GM2 and GM1 hydrolysis were identified as asialo-GM2 and asialo-GM1, respectively, by thin-layer chromatography.

Animals↗
PubMed1986

Electron microscopic and immunohistochemical observations of differentiation of human myeloid leukemia line, PL-21.

A new human myeloid leukemia cell line, PL-21, consisting of promyelocytes, was microscopically and immunohistochemically studied for their maturation induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and retinoic acid (RA). More than 80% of PL-21 cells cultured for 4 days with 10 ng/ml of TPA became macrophage-like cells with functional and histochemical properties consistent with monocytes/macrophages. The cells adhered to the plastic flask, developed phagocytic activity and macrophage-specific intracytoplasmic alpha subunit of S-100 protein, and had reduced myeloid-specific cytochemical markers. In contrast, RA-treated PL-21 cells displayed mature neutrophil-like morphology after 7 days of exposure. Most of the cells had reduced nitro blue tetrazolium and acquired phagocytic activity with persistence of myeloid-specific cytochemical markers such as peroxidase, naphthol-AS-D chloroacetate esterase, and Sudan black B. These results indicate that the PL-21 cell line ca be induced to mature into two directions of macrophages and neutrophils by chemical inducers, and will provide a useful tool for studying the differentiation of leukemic cells and searching for other differentiation inducers.

Cell Differentiation↗