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Biomedical subjects

T Miyagi

Publications and source records attributed to T Miyagi.

At least 91 records · Page 5Linked to original sources

Metastatic potential of transformed rat 3Y1 cell lines is inversely correlated with lysosomal-type sialidase activity.

We have investigated sialidase activities in transformed rat 3Y1 cells of different metastatic potential. Only lysosome-type sialidase was apparent in the particulate fractions of 3Y1 cells and their transformants. As compared with control 3Y1 cells, src-transformed cells exhibited decreased sialidase activity, and v-fos transfer to these latter induced even more severe decrease in the sialidase activity with acquisition of high lung metastatic ability. Various lysosomal enzymes other than sialidase were hardly affected by the transformation. Sialic acid transfer to N-linked glycoproteins was slightly elevated in the transformants, but not in parallel with their metastatic potential.

Animals↗

Fibroepithelial polyp of the verumontanum. A case report and literature review.

A case of fibroepithelial polyp of the verumontanum in a 20-year-old male is presented. The endoscopic examination revealed polypoid lesion protruding from the verumontanum, and transurethral resection of the tumour was performed. The histopathological diagnosis was fibroepithelial polyp, containing no prostatic glandular structures. As the nomenclature of the lesions is widely varying, we tried to classify polypoid or papillary lesions of the prostatic urethra by a literature review.

Adult↗

The effects of sunscreens on UVB erythema and Langerhans cell depression.

Langerhans cells (LCs) are epidermal antigen-presenting cells capable of initiating a specific T lymphocyte-mediated immune response. It is a well known fact that ultraviolet light B (UVB) suppresses LC number and function. In this study, we confirmed that the sunscreens CITY BLOCK, and TOTAL SUN SHIELD 28 (Clinique Laboratories Tokyo, Japan) protected the epidermis against the depletion of LC number. We also investigated whether or not sunscreens could provide LC protection from ultraviolet ray (UVR) damage other than the prevention of the decrease in the total number of cells. Our data showed that the LC population was depressed after irradiation by 100 mJ/cm2 or 10 mJ/cm2 of UVB, but recovered to within normal levels after 16 days. Both sunscreens provided protection against erythema and LC depression due to UVB irradiation. However, despite the fact that these sunscreens had completely suppressed UVB erythema, shrinkage of LC dendrites was seen. Apparently, sunscreens prevent UVB erythema, but do not protect against functional changes in LC due to UVB. Recently, it has been reported that sunscreens are less effective in protecting against systemic immunosuppression that against inflammation. The shrinkage of LC dendrites despite sunscreen application may help explain this discrepancy.

Animals↗

Primary adenocarcinoma of the vermiform appendix associated with transitional cell carcinoma of the bladder.

A case of primary adenocarcinoma of the vermiform appendix coexisting with transitional cell carcinoma (TCC) of the bladder is presented. The patient was a 74-year-old male who underwent radical cystectomy with continent urinary diversion using the Florida pouch. Two different cancers were found, TCC of the bladder and mucinous adenocarcinoma of the appendix. To our knowledge, this is the only such case reported in the medical literature.

Adenocarcinoma, Mucinous↗

Serum-free culture of rat keratinocytes.

Procedures for the serum-free culture of rat keratinocytes have been established. Basal cells prepared from epidermis of newborn rat were stored in liquid nitrogen and used for primary culture. Among the available media, MCDB 153, developed originally for human keratinocyte (HK) culture, was the best for the development of serum-free formulation. To grow rat keratinocytes, bovine serum albumin was arbitrarily substituted for the macromolecule supplements needed for HK culture, i.e. fetal bovine serum protein or bovine pituitary extract. Qualitative and quantitative adjustment of supplements was thereafter made to support rapid cell growth. Satisfactory cell growth was achieved in the optimized medium of MCDB 153 supplemented with growth factors and amino acids: insulin (10 micrograms/ml), hydrocortisone (0.1 microgram/ml), epidermal growth factor (25 ng/ml), calcium chloride (0.2 mM), histidine (0.23 mM), isoleucine (0.05 mM), tryptophane (0.015 mM), threonine (1.25 mM), tyrosine (0.031 mM), alanine (4.08 mM), and albumin (2 mg/ml). This optimized culture system was superior to the original HK culture condition for rapid growth of rat keratinocytes. Under our condition, cells grew as a monolayer, becoming confluent, but without stratification, and were passaged 2 to 3 times without any changes in morphology. The serum-free formulation allows us to control more accurately the concentrations of biomolecules in the medium including lipids and hormones, and therefore will be suitable for the study focusing on lipid metabolism or hormonal regulation of rat keratinocytes.

Amino Acids, Essential↗

Molecular cloning and expression of cDNA encoding rat skeletal muscle cytosolic sialidase.

We have isolated a cDNA clone encoding the cytosolic sialidase of rat skeletal muscle. Degenerate oligonucleotides, based on amino acid sequence data for the purified enzyme, were used as primers to amplify fragments of the gene from rat skeletal muscle cDNA by the polymerase chain reaction. The amplified cDNA fragment was then applied as probe to screen a rat skeletal muscle cDNA library. The longest cDNA clone thus isolated was incomplete at the 5'-end, and therefore an amplified cDNA from the 5'-end portion of the gene was further generated by polymerase chain reaction. These two cDNAs were used to construct a cDNA encoding the entire sequence of rat sialidase. The composite sequence encodes an open reading frame of 379 amino acids that include all sequenced peptides. Although the deduced amino acid sequence is not largely similar to those of bacterial and parasite sialidases, it contains two Asp blocks, the conserved sequence of the sialidases from these microorganisms. When the cDNA was inserted into an expression vector followed by transformation in Escherichia coli, sialidase activity appeared in the cell extract. The sialidase could be completely immunoprecipitated by antiserum against the cytosolic sialidase of rat skeletal muscle.

Amino Acid Sequence↗

Phenotypic and molecular analysis of Ph1-chromosome-positive acute lymphoblastic leukemia cell lines.

We have established 2 Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL) cell lines, designated PALL-1 and PALL-2, from distinct adult Ph1-positive ALL patients. PALL-1 was established in nude mice, and PALL-2 was established in culture. Both retained the Ph1 chromosome and expressed the ALL type bcr/abl chimeric mRNA containing the junction of the first exon of BCR gene (e1) and second exon of c-abl gene (a2). PALL-1 and PALL-2 expressed CD34 surface antigen which is characteristic of early hematopoietic progenitor cells. PALL-2 expressed antigens for both pre-B and early myeloid cells and had rearrangements of both the heavy chain of immunoglobulin gene and the beta chain of T-cell-receptor gene. Both PALL-1 and PALL-2 expressed detectable levels of p53 gene RNA. Polymerase-chain-reaction-single-strand conformation polymorphism (PCR-SSCP) analysis of the p53 gene showed a normal pattern of mobility in both cell lines. Taken together, the 2 cell lines had features of Ph1-positive ALL: (i) hematopoietic progenitor cells with pre-B-cell phenotype and, (ii) activation of e1-a2 type bcr/abl oncogene without alterations of p53 gene. These unique lines should provide a valuable tool for studying the pathogenesis of Ph1-positive ALL.

Adult↗

Differential effect of various inhibitors on four types of rat sialidase.

The inhibitory effect of various compounds on the activities of four types of rat sialidase was investigated. 2-Deoxy-2,3-dehydro-N-acetylneuraminic acid and N-acetylneuraminic acid were competitive inhibitors for the sialidases. The former was effective against cytosolic sialidase and intralysosomal sialidase more than two membrane-associated sialidases I and II, the latter being a much weaker inhibitor. A heavy metal ion such as Cu2+ (1 mM) and thiol-modifying 4-hydroxymercuribenzoate (50 microM) caused complete inhibition of the activities of cytosolic sialidase and membrane sialidase I, while no decrease in the activities of intralysosomal sialidase and membrane sialidase II was observed. When 4-nitrophenyloxamic acid and siastatin B, inhibitors of bacterial sialidases, and synthetic thioglycoside GM3 analogue Neu5Ac alpha-s-(2-6)Gal beta(1-4)Glc beta(1-1) ceramide, an inhibitor of influenza virus sialidase, were tested, they did not affect any activity of the rat sialidases. By the differential effect of these inhibitors, the four types of rat sialidase could be discriminated from one another and furthermore from viral and bacterial sialidases.

Animals↗

Expression of the candidate Wilm's tumor gene, WT1, in human leukemia cells.

Wilms' tumor (WT) is a pediatric malignancy that occurs in embryonic kidney. Recently, a putative Wilms' tumor gene (WT1), located on chromosome 11p13, was isolated and characterized. We found constitutive expression of WT1 mRNA in eight out of 22 hematopoietic cell lines and seven out of 26 clinical samples which were derived from patients with various types of hematologic malignancies. WT1 mRNA was detected in four out of six myeloid cell lines, four out of 10 cases of acute myelocytic leukemia, three out of 15 lymphoid cell lines, one out of nine cases of lymphoid malignancies, and one out of six cases of chronic myelocytic leukemia in accelerated phase and blast crisis. One unclassified hematopoietic cell line and a case of myelodysplastic syndrome also expressed WT1 mRNA. No mutations were detectable in the cell lines by Southern blot analysis and a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis in the four zinc finger domains of the WT1 gene. These results suggest that WT1 gene is expressed in several types of immature lymphoid or myeloid leukemia cells possibly without alterations of the WT1 gene.

Adult↗

Multiple forms of mammalian sialidase: altered expression in carcinogenesis.

We have demonstrated that rat liver contains at least four types of sialidase differing in subcellular location, in catalytic property and immunologically. They are intralysosomal, cytosolic and membrane-associated sialidases I and II. Membrane sialidase I locates mainly in plasma membrane and sialidase II in lysosomal membrane. Immunological study reveals that the same types of sialidase exist in various tissues of rat and of other mammalian species. Based on these results, we examined the sialidases in rat hepatomas and in transformed cells of JB6 mouse epidermal cell. Hepatomas were found to possess four types of sialidase and the three of them altered quantitatively. Intralysosomal sialidase activity was higher but cytosolic and lysosomal membrane sialidase activities were lower in hepatomas than in control liver. When the sialidases of transformants of JB6 cells were compared with those of control cells, the activities of two lysosomal sialidases were decreased and contrarily plasma membrane sialidase was increased. We discussed a possible significance of the sialidase alterations in carcinogenesis.

Animals↗

[Clinical evaluation of flucytosine in patients with urinary fungal infections].

The clinical effectiveness of flucytosine (5-FC) was evaluated in 52 patients with urinary fungal infections which were diagnosed because of the presence of both funguria (greater than or equal to 10(4) cfu/ml) and pyuria (greater than or equal to 5 WBC/hpf). The patients received oral daily doses of 5-FC ranging 20 to 150 mg/kg, with a mean treatment duration of 11 days. The 57 fungus strains isolated from urine specimens consisted of 51 Candida spp. including 28 Candida albicans, 10 Candida glabrata, 4 Candida tropicalis and 6 Trichosporon beigelii. Forty-seven (92.2%) and 4 (66.7%) of the 51 Candida spp. and 6 T. beigelii strains isolated were eradicated by the treatment, respectively, giving an overall eradication rate of 89.5%. Clinical responses in 32 patients, from whom only fungi were submitted, were excellent in 5, moderate in 22, and poor in 5, thus the overall efficacy rate was 84.4%, based on the criteria of Japanese UTI Committee. Of the 18 strains of Candida spp. tested, 5-FC showed 0.20 micrograms/ml or less of the minimum inhibitory concentrations (MICs) against 16 strains and higher than 100 micrograms/ml against the remaining 2 strains. The MICs of the 5 T. beigelii strains tested were between 3.12 and 6.25 micrograms/ml. As adverse reactions, only 2 patients (3.8%) experienced diarrhea but did not require treatment cessation. These results suggest that flucytosine is an effective drug for urinary fungal infections.

Adult↗

[Intensive induction chemotherapy of adult acute myelogenous leukemia by continuing daunorubicin, behenoyl-cytosine arabinoside, 6-mercaptopurine and prednisolone until marrow aplasia].

Intensive induction chemotherapy was applied to 25 patients with acute myelogenous leukemia by continuing drugs (daunorubicin, behenoyl-cytosine arabinoside, 6-mercaptopurine and prednisolone) until the achievement of severe bone marrow aplasia (leukemic cells less than 1,000/microliters). Complete remission (CR) was achieved in 18 (72%). Numbers of partial remission and an early death were 5 (20%) and 2 (8%), respectively. Although median nadirs of white blood cells (WBC) and platelet counts (Pl) (205/microliters and 8,200/microliters, respectively) were remarkably low, recovery of WBC (over 1,000/microliters) and Pl (over 50,000/microliters) were achieved in 23.8 and 24.5 days, after an initiation of the chemotherapy. Sepsis was a most frequently observed complication during induction stage and a duration of fever was 2-48 days (median 15). Median duration of CR was 22.9 months. Unexpectedly, 11 of 17 CR (except one with bone marrow transplanted) relapsed after 4.2-41.4 months (median; 9.4), but 6 (35.3%) still remain in first CR for 30.5-72.9 months (median; 51.4). A long-term survival might be obtained by intensifying induction chemotherapy in about one fourth of patients, but the intensification or application of non-cross resistant anti-leukemic agents in post-remission therapy may be required to avoid relapses even if induction is intensified.

Administration, Oral↗

Acute megakaryoblastic leukemia: establishment of a new cell line (MKPL-1) in vitro and in vivo.

A megakaryoblastic cell line (MKPL-1) was newly established from the bone marrow of an adult patient with acute megakaryoblastic leukemia. This cell line grew in single cell suspension with a doubling time of 30 h and consisted of large primitive blasts with persistent development of giant cells carrying multilobed nuclei. MKPL-1 cells were positive for platelet GPIIb/IIIa (CD41) and GPIIIa (CD61), and expressed OKM5 (CD36), MY7 (CD13), and MY9 (CD33) antigens in the absence of erythroid and lymphoid markers. The cytochemical and morphologic characteristics of MKPL-1 were also consistent with those of megakaryoblasts. The cells did not, however, express ultrastructural platelet peroxidase which is considered to be another marker of the megakaryocytic lineage. Cytogenetic analysis of MKPL-1 revealed a model chromosome number of 92 with abnormal chromosomes including those found in the patient's bone marrow cells. Furthermore, MKPL-1 cells were serially transplanted into nude mice for nine passages with production of lethal tumors and leukemic manifestation. Thus, our megakaryoblastic cell line which can be maintained both in vitro and in vivo would be useful for further studies of the biology of megakaryopoiesis and megakaryoblastic leukemia.

Aged↗

D-factor: modulation of expression in fibroblasts.

Differentiation inducing factor (D-factor) is a recently described protein. The gene has been cloned, but little is known concerning regulation of expression of the gene. Our study showed that fibroblasts from a variety of tissues (lung, bone marrow, gingiva, foreskin) constitutively expressed D-factor RNA. Levels of expression of this gene increased in fibroblasts of each of the tissues after exposure to several stimuli including products of activated macrophages and lymphocytes (tumor necrosis factor (TNF), interleukin 1 and lymphotoxin). Other stimuli were those capable of activating either protein kinase C (12-O-tetradecanoylphorbol-13-acetate (TPA) and teleocidin), G-binding proteins (NaF) or those inhibiting protein synthesis (cycloheximide). Accumulation of D-factor RNA by TNF may in part be explained by stabilization of D-factor transcripts; TPA and cycloheximide clearly stabilized D-factor transcripts. We and others have shown that these same signals similarly stimulated fibroblasts to express RNAs coding for a variety of cytokines including three colony-stimulating factors as well as interleukins 1 and 6. Taken together, D-factor probably is a participant in the cascade of cytokines that are produced in mesenchymal cells after various stimuli such as bacterial invasion.

Cells, Cultured↗

Bacteremia from transurethral prostatic resection under prophylactic use of antibiotics.

We studied the incidence of the postoperative bacteremia developing in 44 patients undergoing transurethral resection of the prostate under prophylactic use of antibiotics. In 15 of the patients, postoperative endotoxinemia was also investigated. Postoperative bacteremia was found in 10 (22.7%) of the patients, in only one of whom septicemia developed. The incidence of bacteremia was not influenced by the kind of antimicrobial agent administered prophylactically, but was significantly higher in the patients with preoperative urinary tract infection or prostatitis on histological examination of resected prostatic tissue (p less than 0.01). Concerning species isolated from the blood, gram-positive cocci were isolated more frequently than gram-negative bacteria, and Staphylococcus epidermidis was the most common species. In 7 (70%) of the bacteremia patients an identical species was isolated from preoperative urine cultures. In the patients with bacteremia, significant increases in white blood cell count and maximal body temperature were found within 3 hours after the procedure as compared to before the procedure. To lower the postoperative bacteremic rate, appropriate and adequate antimicrobial agents must be used preoperatively in patients with infection of the genitourinary tract. As to blood endotoxin, the endotoxin levels in the patients with postoperative fever did not significantly differ from those of the patients without this complication.

Aged↗

A Ki-1 (CD30)-positive T (E+, CD4+, Ia+)-cell line, DL-40, established from aggressive large cell lymphoma.

A new human lymphoma cell line, designated DL-40, was established from the peripheral blood of a 64-year-old woman with leukemic conversion of aggressive large cell lymphoma. The cell line grew in suspension with or without forming clumps of cells and exhibited large, round, or multiple nuclei in the relatively abundant cytoplasm that was positive for acid phosphatase. The cells expressed a Ki-1 antigen (CD30), E+, CD2+, CD4+, CD45+, Ia+ phenotype and had rearranged T-cell receptor beta chain but were negative for CD15, HTLV-I, and Epstein-Barr virus nuclear antigen. Chromosome analysis of this cell line showed a human female karyotype with complex hyperdiploid abnormalities. DL-40 cells produced tumors histologically similar to the original lymphoma when transplanted into nude mice and immunosuppressed hamsters. The DL-40 cell line could provide a useful tool for the understanding of biology of the Ki-1-positive non-Hodgkin's lymphoma.

Antigens, Differentiation↗

Characterization of the major sialidases of various types of rat blood cells: their comparison with rat liver sialidases.

The substrate specificity and subcellular location of the major sialidases of three types of rat blood cells were characterized and compared with those of the known three types of rat liver sialidase, which have been designated intralysosomal, cytosolic, and plasma membrane-associated sialidases. Platelets and leucocytes contain mainly an acid sialidase, which is highly active towards oligosaccharides and 4MU-NeuAc, and erythrocytes possess a high level of a sialidase acting on gangliosides. A Percoll gradient centrifugation study showed that the former is located in lysosomes and the latter in plasma membrane. When the sialidase was solubilized and partially purified from erythrocyte ghosts, the enzyme was found to hydrolyze actively gangliosides but only poorly other substrates such as 4MU-NeuAc, oligosaccharides, and glycoproteins. The sialidase partially purified from rat liver membrane fraction exhibited the same substrate specificity. It is concluded that the major sialidase of platelets and leucocytes corresponds to hepatic intralysosomal sialidase while erythrocytes contain almost exclusively a ganglioside sialidase which corresponds to hepatic plasma membrane sialidase.

Animals↗