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Biomedical subjects

K Miyake

Publications and source records attributed to K Miyake.

At least 217 records · Page 12Linked to original sources

Efficient isolation of mutant antigen presenting cell lines by functional selection using T cell clones.

An efficient method for the isolation of mutant antigen-presenting cell (APC) lines is described. When mixtures of transfectant APC lines TA beta z (that express A beta z/A alpha d MHC class II molecules) and hypothetical variant APC lines TA beta d (that express A beta d/A alpha d class II molecules) were cultured with and selected by autoreactive A beta z/A alpha d-restricted T cell clones, the percentage of TA beta d APC lines increased from less than 1% of the original APC mixtures to almost 100% after several cycles of selection. This increase of hypothetical variant was shown to be due to the formation of aggregates of wild-type TA beta z APC lines with A beta z/A alpha d-restricted autoreactive T cell clones that results in the inhibition of proliferation and probably killing of TA beta z APC lines. Based on this, ethyl methane sulfonate (EMS)-treated TA beta z APC lines or B-B hybridoma APC lines MW4 (that express A beta z/A alpha d and A beta z/A alpha z class II molecules) were cultured with and selected by A beta z/A alpha d-restricted autoreactive T cell clones to obtain mutant APC lines that escaped the recognition by T cell clones. After cloning, about 43% of clones examined lost the ability to stimulate T cell clones with concomitant loss of class II molecule expression. Less than 1% showed loss of stimulatory activity against T cell clones in spite of the expression of normal amounts of class II molecules. Initial analysis revealed that they include APC mutant lines with (1) altered MHC class II sequences, (2) loss of adhesion molecule expression and (3) possible impairment of the peptide loading. The method described here may provide a variety of mutant APC lines that are useful for the analysis of antigen processing and presentation pathways as well as of class II structure for T cell stimulation.

Animals↗

The Impacts of Breast Conserving Treatment and Mastectomy on the Quality of Life in Early-stage Breast Cancer Patients.

The quality of life (QOL) in 55 early-stage breast cancer patients after surgery was prospectively assessed using a newly developed Japanese QOL questionnaire: The QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs (QOL-ACD). The impacts of breast conserving treatment (BCT) (22 cases) and modified radical mastectomy (MRM) (33 cases) on the QOL in those subjects were compared. The overallQOL scores were evaluated during four periods (before surgery, 0-2, 3-12, and 13-24 months after surgery). The mean scores of the four categories of the QOL-ACD (activity, physical condition, psychological condition, and social relationships) were also compared. The results demonstrated that a significant improvement was observed in the overall QOL scores among the three periods after surgery (0-2, 3-12, and 13-24 months) only in the BCT group (p<0.05). There were no significant differences between the two groups in the overall QOL scores during any of the three periods after surgery, and the mean score of the 'psychological condition' during 0-2 months period in the BCT group was significantly lower than that in the MRM group (p<0.05). These results suggest that BCT does not always improve the patients' QOL more than MRM does, and that the patients receiving BCT require more psychological support than those receiving MRM during the early postoperative period.

Journal Article↗

Protein tyrosine kinases expressed in glomeruli and cultured glomerular cells: Flt-1 and VEGF expression in renal mesangial cells.

Protein tyrosine kinases play an important role in cellular proliferation and differentiation of various cell types. To identify potential tyrosine kinases involved in glomerular functions we have utilized the polymerase chain reaction (PCR) and degenerate oligonucleotides for isolation of such genes from isolated glomeruli, cultured mesangial cell, and glomerular endothelial cells. Sequence analysis of PCR-amplified cDNAs resulted in the isolation of 24 tyrosine kinases. Here we describe for the first time the constitutive expression of 15 tyrosine kinases, tyro-1, tyro-4, tyro-6, hyk, Ptk-3, Ryk, tie, yes, lyn, tec, Jak1, Jak2, Jak3, c-abl, and flk, in renal glomeruli. In addition, Flt-1, an endothelial cell-specific receptor for vascular endothelial growth factor (VEGF), is expressed in renal mesangial cells and its gene expression is up-regulated upon the stimulation of platelet-derived growth factor (PDGF) with the concomitant up-regulation of VEGF. These data suggest that possible involvement of VEGF/Flt-1 system in cytokine-induced mesangial cell proliferations.

Animals↗

RP105, a novel B cell surface molecule implicated in B cell activation, is a member of the leucine-rich repeat protein family.

The RP105 Ag is a murine B cell surface molecule that transmits an activation signal into B cells following ligation with anti-RP105 mAb. The activation leads to protection of B cells from irradiation- or dexamethasone-induced apoptosis, and to B cell proliferation. A cDNA encoding the RP105 Ag was isolated. An encoded protein is a type I transmembrane protein consisting of 641 amino acids in a mature form. Northern hybridization with a probe specific for the cDNA clone detected a transcript with a size of approximately 3 kb. The transcript was observed in spleen, but not in thymus, kidney, muscle, heart, brain, or liver. Stable transfection of the cDNA clone conferred the expression of the RP105 Ag on a pro-B cell line, which was confirmed by immunofluorescence staining and immunoprecipitation with anti-RP105 mAb. The RP105 molecule possesses 22 tandem repeats of a leucine-rich motif. These repeated motifs are observed in members of the leucine-rich repeat protein family, and have been implicated in protein-protein interactions, such as cell adhesion or receptor-ligand binding. Amino- and carboxyl-flanking regions that are characteristically conserved among members of the family are located on both sides of tandemly repeated leucine-rich motifs in RP105 molecule. These results demonstrate that RP105 is a novel member of the leucine-rich repeat protein family, and the first member that is specifically expressed on B cells.

Amino Acid Sequence↗

Inactivation of the DCC tumor suppressor gene in a B-cell lymphoma cell line with the alteration of chromosome 18.

A B-cell lymphoma cell line, designated KML-1, was established from pleural effusion of a patient with non-Hodgkin's lymphoma of large-cell type. The lymphoma arose in the pelvis and ran an aggressive clinical course. Chromosome analysis of the cell line exhibited a complex karyotype including the loss of chromosome 18. To evaluate the molecular events in the cell line that may be associated with the development of the lymphoma, we investigated the expression and/or alterations of several classes of human genes, including oncogenes, tumor suppressor genes, and cytokine genes. The expression of the DCC (deleted in colorectal cancer) gene, located on the chromosome 18q21, was extremely reduced in KML-1 cell line, as compared with that in a normal spleen tissue and other 4 lymphoma cell lines by the reverse transcription-polymerase-chain-reaction (RT-PCR) method. This finding suggests that inactivation of the DCC gene might play a role in the pathogenesis of the case of lymphoma.

Adult↗

Evaluation of a low-dose intravesical bacillus Calmette-Guérin (Tokyo strain) therapy for superficial bladder cancer.

To examine whether intravesical instillation of low-dose bacillus Calmette-Guérin (BCG) therapy is effective with low toxicity, we reviewed data for 111 patients with superficial bladder cancer (stages Ta and T1). Among them, 74 received the BCG treatment for prophylaxis of intravesical recurrence after transurethral resection, and the remaining 37 therapeutically for Ta or T1 tumours. The patients were divided into two groups by instillation dose of BCG (Tokyo 172 strain): 40 mg (n = 55) and 80 mg (n = 56), and statistically compared for recurrence, antitumour effect and toxicity. The mean instillations were done 8.4 times in the 40 mg dose group and 8.6 times in the 80 mg dose group. Among the 74 patients with BCG therapy for prophylaxis those with a previous episode of bladder cancer treatment (n = 47) experienced a significantly (p = 0.006) shorter recurrence-free interval than those with no episode (n = 27). Among 47 patients with a previous treatment episode, those receiving the 80 mg dose demonstrated a significantly longer recurrence-free interval than those given the 40 mg dose (p = 0.03). Among the 27 patients without previous treatment no significant difference in recurrence-free intervals was found between the two dose groups. Univariate and multivariate analyses using Cox's proportional hazards model confirmed the above findings. The recurrence index was also significantly reduced after BCG therapy in the 80 mg and 40 mg groups and similar antitumour effects for Ta or T1 tumours were observed in the two dose groups. The degree of toxicity due to BCG therapy was significantly (p = 0.02) lower with the 40 mg dose. The present study suggests that (1) a 40 mg BCG low-dose (Tokyo 172 strain) regimen is useful for preventing recurrence, with sufficient therapeutic efficacy and low frequency of toxicity, among patients without a previous treatment, and (2) prophylactic effects with the 80 mg dose regimen are much superior for previous treatment cases.

Aged↗

Surgical treatment of renal cell carcinoma metastases: prognostic significance.

Between January 1980 and March 1993, 166 patients with renal cell carcinoma were treated at Nagoya University Hospital. Among them 16 (9.6%) underwent surgical removal of 21 metastatic lesions: 12 patients had distant metastases at diagnosis and the other 4 demonstrated new distant metastases during their clinical course after nephrectomy. The metastatic lesions involved the brain in 6 patients, bone in 4, lung in 2, contralateral adrenal glands in 2, soft tissues in 2, lymph nodes in 2, pleura in 1, pancreas in 1, and contralateral renal pelvis in 1. All of the 16 patients underwent nephrectomy and 15 of them (93%) received interferon-alpha therapy. Patients with lesions which were completely resected had significantly longer survival than those with lesions which were palliatively treated and those with metastatic lesions at other sites (p = 0.02). Improvement of performance status was observed in 5 of 6 (83%) patients undergoing palliative surgical treatment. The present study suggests that surgical removal of metastatic lesions prolongs survival in a limited number of renal cell carcinoma patients and that it improves performance status in those symptoms related to metastasis.

Bone Neoplasms↗

Establishment and characterization of a villous lymphoma cell line from splenic B-cell lymphoma.

A new B-cell line (VL51) with cytoplasmic villi was established from a female patient with splenic lymphoma with circulating villous lymphocytes (SLVL). The patient exhibited a clinical picture characteristic of SLVL, including massive enlargement of the spleen. Tartrate-resistant acid phosphatase (TRAP)-negative villous lymphocytes were seen in the peripheral blood, bone marrow (BM) and both red and white pulps of the spleen. Monoclonality of the VL51 cell line was confirmed by clonal genotype abnormalities in the immunoglobulin heavy chain (IgH) gene and the T-cell receptor beta (TCR beta) gene. Evidence for commitment of phenotype of the VL51 cell line to the B lineage was also shown by the immunophenotype, including expression of CD10, CD19, CD20 and surface immunoglobins. The VL51 cells were positive for Epstein-Barr virus nuclear antigen (EBNA). The VL51 cell line is the first SLVL cell line to be established, and it is expected to be useful in clarifying the leukemogenesis of SLVL.

Acid Phosphatase↗

Developmental defects of lymphoid cells in Jak3 kinase-deficient mice.

Jak3 is a tyrosine kinase mediating cytokine receptor signaling through the association with the common gamma chain of the cytokine receptors such as IL-2, IL-4, IL-7, IL-9, and IL-15. Unlike other members of the Jak family, the expression of Jak3 is highly restricted in hematopoietic cells. To elucidate in vivo function of Jak3, Jak3-deficient mice were generated by homologous recombination. Mice homozygous for Jak3 null mutation showed severe defects, specifically in lymphoid cells. B cell precursors in bone marrow, thymocytes, and both T and B cells in the spleen drastically decreased, although these defects were significantly recovered as aging occurred. Peripheral lymph nodes, NK cells, dendritic epidermal T cells, and intestinal intraepithelial gamma delta T cells were absent. Normal number of hematopoietic stem cells in bone marrow from Jak3-deficient mice and the similar capability to generate myeloid and erythroid colonies as wild-type mice indicated specific defects in lymphoid stem cells. Furthermore, the abnormal architecture of lymphoid organs suggested the involvement of Jak3 in the function of epithelial cells. T cells developed in the mutant mice did not respond to either IL-2, IL-4, or IL-7. These findings establish the crucial role of Jak3 in the development of lymphoid cells.

Animals↗

Comparison of the effectiveness of placebo and alpha-blocker therapy for the treatment of idiopathic oligozoospermia.

OBJECTIVE: To determine whether alpha-blocker (bunazosin) improves fertility and/or semen parameters DESIGN: Placebo-controlled, double-blind clinical study. SETTING: Nagoya University Hospital Andrology Clinic, Nagoya, Japan. PATIENTS: Thirty-four men with sperm density between 5 and 20 x 10(6) sperm/mL, normal serum gonadotropins and T, and a fertile partner were enrolled in this study. INTERVENTIONS: After a 3-month control period, patients randomly were prescribed bunazosin 2 mg/d or a placebo, two tablets per day, for 6 months. Semen and blood samples were collected before and after therapy. Semen parameters, serum gonadotropins, T, PRL, and E2 were evaluated before and after therapy. RESULTS: The pregnancy rate (PR) in the alpha-blocker group was 25%, compared with 6.7% in the placebo group. There was no statistical difference in the PR between groups. The alpha-blocker group had significantly higher levels of sperm density and total motile sperm count. There were no differences between the placebo and alpha-blocker groups in seminal volume, the percentage of motile sperm, and normal morphology or hormone levels. CONCLUSIONS: The authors conclude that alpha-blocker is a useful drug in the treatment of idiopathic moderate oligozoospermic men.

Adrenergic alpha-Antagonists↗

New treatment of idiopathic severe oligozoospermia with mast cell blocker: results of a single-blind study.

OBJECTIVE: To determine whether mast cell blocker (tranilast) improves fertility and/or semen parameters in severe oligozoospermia. DESIGN: Placebo-controlled single-blind clinical study. SETTING: Nagoya University Hospital Andrology Clinic, Nagoya, Japan. PATIENTS: Fifty men with sperm density < 5 x 10(6) sperm/mL, normal serum gonadotropins, and T, and a fertile partner were enrolled in this study. INTERVENTIONS: Patients were prescribed randomly 300 mg/d tranilast or a placebo, three tablets per day, for 3 months. Semen and blood samples were collected before and after therapy. Semen parameters, serum gonadotropins, T, and PRL were evaluated before and after therapy. RESULTS: The pregnancy rate (PR) in the mast cell blocker group was 28.6% compared with 0% in the placebo group. There was a statistical difference in the PR between groups. The mast cell blocker group had significantly higher levels of sperm density, sperm motility, and total motile sperm count. There were no differences between the mast cell blocker and placebo groups in seminal volume and normal sperm morphology. CONCLUSIONS: The authors conclude that mast cell blocker is clinically useful for the treatment of idiopathic severe oligozoospermic men.

Adult↗

Monoclonal antibodies to CD44 and their influence on hyaluronan recognition.

Antibodies to CD44 have been used to inhibit a variety of processes which include lymphohemopoiesis, lymphocyte migration, and tumor metastasis. Some, but not all, CD44-mediated functions derive from its ability to serve as a receptor for hyaluronan (HA). However, sites on CD44 that interact with either ligands or antibodies are poorly understood. Interspecies rat/mouse CD44 chimeras were used to analyze the specificity of 25 mAbs and to determine that they recognize at least seven epitopes. Amino acid substitutions that resulted in loss of antibody recognition were all located in the region of homology to other cartilage link family proteins. While at least five epitopes were eliminated by single amino acid replacements, multiple residues had to be changed to destroy binding by other antibodies. One antibody was sensitive to changes in any of three separate parts of the molecule and some antibodies to distinct epitopes cross-blocked each other. Certain antibodies had the ability to increase HA binding by lymphocytes but this did not correlate absolutely with antibody specificity and was only partially attributable to CD44 cross-linking. Antibodies that consistently blocked HA recognition were all sensitive to amino acid changes within a short stretch of CD44. Such blocking antibodies interacted with CD44 more strongly than ligand in competition experiments. One large group of antibodies blocked ligand binding, but only with a particular cell line. This detailed analysis adds to our understanding of functional domains within CD44 and requirements for antibodies to influence recognition of one ligand.

Amino Acid Sequence↗

Vesicle accumulation and exocytosis at sites of plasma membrane disruption.

Plasma membrane disruptions are resealed by an active molecular mechanism thought to be composed, in part, of kinesin, CaM kinase, snap-25, and synaptobrevin. We have used HRP to mark the cytoplasmic site of a mechanically induced plasma membrane disruption. Transmission electron microscopy revealed that vesicles of a variety of sizes rapidly (s) accumulate in large numbers within the cytoplasm surrounding the disruption site and that microvilli-like surface projections overlie this region. Scanning electron microscopy confirmed that tufts of microvilli rapidly appear on wounded cells. Three assays, employing the membrane specific dye FM1-43, provide quantitative evidence that disruption induces Ca(2+)-dependent exocytosis involving one or more of the endosomal/lysosomal compartments. Confocal microscopy revealed the presence in wounded cells of cortical domains that were strikingly depleted of FM dye fluorescence, suggesting that a local bolus of exocytosis is induced by wounding rather than global exocytosis. Finally, flow cytometry recorded a disruption-induced increase in cell forward scatter, suggesting that cell size increases after injury. These results provide the first direct support for the hypothesis that one or more internal membrane compartments accumulate at the disruption site and fuse there with the plasma membrane, resulting in the local addition of membrane to the surface of the mechanically wounded cell.

Animals↗

Effects of alpha-blocker on sperm concentration, motility, intraluminal pressure and fluid movement in the rat cauda epididymis.

PURPOSE: To investigate whether alpha blocker has an effect on epididymal sperm parameters, intraluminal pressure and fluid movement. MATERIALS AND METHODS: Sprague-Dawley rats were given daily oral doses 1 mg./kg., 2 mg./kg., or 10 mg./kg. of Bunazosin, a selective alpha blocker, for 1 month. A micropuncture technique was used to collect intraluminal fluids. RESULTS: Epididymal sperm concentrations were significantly increased. Progressive motility of spermatozoa was not altered. Intraluminal pressures were significantly reduced, and intraluminal fluid movement rates were significantly increased. CONCLUSION: Alpha blocker has an effect on sperm transport and storage in the rat testis and epididymis.

Adrenergic alpha-Antagonists↗

Bulk sperm collection by epididymal micropuncture and stimulation of the spermatic nerve; a novel method for sperm retrieval for IVF for surgically irreparable vasal obstruction.

We have developed a new sperm collection method by epididymal micropuncture in conjunction with perivascular nerve stimulation to obtain as many uncontaminated spermatozoa as possible for IVF for patients with surgically unreconstructable vasal obstruction. Fifteen azoospermic men with congenital absence of the vas deferens or vasal obstruction not amenable to surgical repair enrolled in this study. Under general anaesthesia the testis and epididymis were retrieved and stabilized in a testicular holder with the aid of 2% agar. The epididymal micropuncture was performed using a micropipette placed in a micromanipulator. A pair of Ag-AgCl ring electrodes were placed around the spermatic cord for perivascular nerve stimulation with DC (intensity 136 V, frequency 20 Hz) for 30 s. Electrical stimulation was repeated every 1 min until no further fluid was obtained. Epididymal fluid obtained ranged from 78 to 980 microliters (mean 169 microliters). Sperm concentration ranged from 0.7 to 200 million (mean 53.5 million). Sperm motility ranged from 0.5% to 70% (mean: 19.9%). The percentage of spermatozoa with normal morphology ranged from 3% to 32% (mean 16.4%). Of 16 cycles in which spermatozoa and oocytes were retrieved, 56% (9/16) resulted in fertilization and 18.8% (3/16) developed clinical pregnancies. The clinical pregnancy rate per couple was 20% (3/15). This is the first clinical experience of the bulk sperm collection system for IVF for the treatment of unreconstructable obstructive azoospermia. Our results indicate that our new technique, in conjunction with IVF, is clinically useful for patients with surgically irreparable vasal obstruction.

Cell Separation↗