Biomedical subjects

K Miyake

Publications and source records attributed to K Miyake.

At least 289 records · Page 16Linked to original sources

PubMed1994

Recognition of murine integrin beta 1 by a rat anti-stromal cell monoclonal antibody.

Previous studies with the rat monoclonal antibody KMI6 had localized its antigen in vivo to a discrete subpopulation of marrow stromal cells. The KMI6 antigen has now been identified as the murine homolog of integrin beta 1 by amino acid sequence analysis and by cross-reactivity with antiserum to the avian integrin beta 1. The relative tissue abundance of murine integrin beta 1 was determined by Western blot. Although immunoperoxidase staining of fixed murine hematopoietic tissues demonstrated an abundance of intracellular beta 1, few primary-derived cells of lymphohematopoietic origin were surface positive as assessed by immunofluorescence and flow cytometry. Fetal erythroblasts provided the only exception. In contrast, the antigen was readily detected on the surface of several cultured cell lines in association with a variety of alpha chains. The biochemical properties of the surface labeled murine integrin beta 1 were similar to those of its human counterpart, exhibiting an altered electrophoretic migration under reduced conditions or following N-glycanase treatment. The antibody recognition of the protein was insensitive to glycosylation state, presence of divalent cations, detergents, or transfer to a nitrocellulose membrane. However, on Western blot, the epitope was lost on reduction of the protein, suggesting that it is conformation dependent. These data indicate that although KMI6 epitope is widely distributed, its surface expression in vivo may be restricted within lymphohemopoietic tissues.

Amino Acid Sequence↗

PubMed1994

Pre-B cells adhere to fibronectin via interactions of integrin alpha 5/alpha V with RGDS as well as of integrin alpha 4 with two distinct V region sequences at its different binding sites.

The present study aimed to develop an assay system capable of directly examining the adhesion of cells to each cell-binding site on fibronectin (FN) and to investigate molecular mechanisms underlying the pre-B cell-FN interaction. Treatment of culture plates with 3-(2-pyridyldithio) propionic acid N-hydroxysuccinimide ester and subsequently with dithiothreitol (DTT) allowed the plates to adsorb DTT-treated extracellular matrix (ECM) proteins as well as synthetic peptides containing cysteine at the N-terminal. These treatments produced culture plates coated with ECM proteins or peptides corresponding to its cell-binding sequences, i.e. three sites on FN termed RGDS, LDVP, and RGDV. Pre-B cells exhibited potent adhesiveness to FN-coated plates. Its FN binding was most efficiently inhibited by adding a combination of free forms of RGDS, LDVP, and RGDV peptides, indicating the involvement of these three cell-binding sites in the pre-B cell-FN interaction. In accordance with this, pre-B cells exhibited considerable and potent binding to the respective RGDS-, LDVP-, or RGDV-coated plates. Such binding was specific for the peptide used for coating, because each binding to a given peptide-coated plate was inhibited only by addition of a homologous free peptide. This assay system further demonstrated that the pre-B cell binding to RGDS was mediated by the alpha 5 and alpha v integrins, whereas the binding to LDVP and RGDV was mediated by the alpha 4 integrin. It was also shown that LDVP binding was inhibited by LDVP but not by RGDV and, likewise, RGDV binding was inhibited by RGDV but not by LDVP.2+ interaction involving complex molecular mechanisms.

Amino Acid Sequence↗

PubMed1994

Activation-induced expression of thymic shared antigen-1 on T lymphocytes and its inhibitory role for TCR-mediated IL-2 production.

We have produced a hamster mAb, PRST1, which reacts with thymic shared Ag-1 (TSA-1), a product of the Ly6 gene family. By cross-blocking experiments, we found that TSA-1 is identical to stem cell Ag-2 (Sca-2). Using PRST1, the changes of TSA-1/Sca-2 expression on mature T cells during the activation process were analyzed. Although freshly isolated T cells did not express detectable TSA-1 on their cell surface, in vitro stimulation of T cells with concanavalin A induced a marked increase of surface TSA-1 expression. The increased expression of TSA-1 on T cells was detected from 12 h after stimulation and was associated with the increase of TSA-1 mRNA. In vivo injection of mice with staphylococcal enterotoxin B (SEB) resulted in the enhanced TSA-1 expression in splenic V beta 8+ T cells. This antigen-specific induction of TSA-1 expression in vivo preceded a detectable increase in numbers of V beta 8- T cells after SEB injection. Functionally, whereas anti-TSA-1 mAb was not mitogenic to T cells, it inhibited anti-CD3-induced IL-2 production by T cell hybridomas. These results indicate that TSA-1/Sca-2 is a unique marker for T cell activation and a signal through this molecule may have a negative feedback role to limit IL-2 production from activated T cells stimulated through the TCR.

Animals↗

PubMed1994

A calcium- or manganese-dependent epitope on the integrin beta 1 chain recognized by a unique mAb.

A calcium- or manganese-dependent epitope was demonstrated on the beta 1 integrin chain by a newly established mAb. In immunoprecipitation, the mAb was able to bind to the solubilized beta 1 integrin chain in the presence of calcium but not magnesium. Cation chelating reagents completely affected the binding of the antibody to the intact beta 1 integrin chain on a cell surface. Calcium but not magnesium restored the binding of the antibody. Quantitative analyses revealed that chelating reagents reduced the affinity of the antibody. Moreover, manganese also rescued epitope expression. These results suggested that divalent cations, particularly calcium or manganese, had a crucial role in the conformation of the beta 1 integrin chain recognized by the SG/7 antibody. This antibody would be of great use for studying the divalent cation-dependent modulation of the integrin molecules and bring another aspect to the understanding of the regulatory mechanisms of ligand binding of the integrin molecules.

Antibodies, Monoclonal↗

PubMed1994

Androgen receptor expression in the preputial gland and its sebocytes.

As in other sebaceous glands, preputial gland sebocytes are stimulated to proliferate and produce lipid by androgen. As a necessary step in understanding the role of androgen in sebaceous gland growth and development, we have undertaken studies to determine the relationship between androgen receptor gene expression and sebocyte differentiation. Sebocytes throughout the preputial gland, with the exception of some basal sebocytes, stain intensely for androgen receptor. Quantitative assessment of androgen receptor mRNA by RNase protection assay confirms that androgen receptor mRNA abundance is similar in sebaceous and prostate epithelial cells, but is tenfold less in epidermal cells. When sebocytes were separated according to their state of differentiation by gradient density centrifugation, sebocytes in the 1.080 density fraction contrasted with the more buoyant fractions in that they immunostained weakly for androgen receptors. The 1.080 fraction consists of approximately 50% immature (undifferentiated and early differentiated) sebocytes, whereas more mature sebocytes predominate in the other fractions. Androgen receptor mRNA quantity was found by RNase protection assay to be half as great in the 1.080 density fraction as in the fractions in which more mature sebocytes predominate. In primary monolayer culture androgen receptor mRNA content was significantly higher in sebaceous epithelial cells than in epidermal cells and similar to that in the 1.080 fraction of freshly dispersed sebocytes. These results suggest that there is little if any androgen receptor gene expression in undifferentiated preputial sebocytes and that androgen receptor gene expression increases as sebocytes begin to differentiate. Because androgen receptor expression seems to approach its maximum as sebocytes attain mid-differentiation, the stage at which sebocytes switch from a proliferative mode to commence their specialized holocrine function, androgen is postulated to play a direct role in regulating these aspects of sebocyte development.

Animals↗

PubMed1994

Signal transmission through MHC class II molecules in a human B lymphoid progenitor cell line: different signaling pathways depending on the maturational stages of B cells.

The function of MHC class II HLA-DR molecules expressed on a human B lymphoid progenitor cell line FL8.2.4.4 (abbreviated as FL4.4) was examined. FL4.4 cells expressed HLA-DR molecules and stimulation of the DR molecules by anti-DR mAb or by superantigen TSST-1 induced strong augmentation of homocytic aggregation and protein tyrosine phosphorylation in FL4.4 cells. Induced homocytic aggregation in FL4.4 consists both of LFA-1/ICAM-1-dependent and -independent pathways as revealed by mAb blocking experiments. Metabolic inhibitors, NaN3 and cytochalasin B, blocked the induced homocytic aggregation of FL4.4. Early mature Daudi B cell lines also showed a similar type of homocytic aggregation by stimulation with anti-DR mAb. Daudi cells are more sensitive to protein kinase inhibitors herbimycin A and H7 than FL4.4 cells in their blocking of induced homocytic aggregation, while W7 showed stronger inhibitory effects on FL4.4 cells than on Daudi cells. Western blotting analysis revealed that the stimulation of DR molecules induced protein tyrosine phosphorylation of 100-kDa, 90-kDa, 60-kDa and 55-kDa proteins in FL4.4 cells, while, in Daudi cells 110-kDa, 100-kDa and 80-kDa proteins were phosphorylated. These results suggest that different signaling pathways through class II molecules are employed depending on the maturational stage of B-cell differentiation.

Antibodies, Monoclonal↗

PubMed1994

CD30 antigen in non-Hodgkin's lymphoma.

Expression of the CD30 antigen in lymphoid neoplasms and reactive lesions were examined immunohistologically using the monoclonal antibody BerH2. CD30 antigen was expressed in 17 of 18 patients with Hodgkin's disease (HD), all of three anaplastic large cell lymphomas (ALCL), 11 of 52 T-cell malignant lymphomas (TML) including ALCL, 13 of 153 B-cell malignant lymphomas (BML) including ALCL, two of three malignant histiocytosis and one of four plasmacytomas. Although a single case of small cell lymphoma was positive, in cases of mixed cellular morphology, neoplastic cells of larger or more pleomorphic nuclei tended to be stained more extensively and intensively. This antigen is expressed in TML significantly more often than in BML (P < 0.05). CD30 antigen was expressed less frequently at clinical stage I than those of stages II to IV. There was no significant relationship between CD30 antigen expression and that of proliferating cell nuclear antigen or CD43 antigen in non-Hodgkin's lymphomas (NHL). The CD30 antigen expression did not affect the prognosis of NHL overall, but in high grade TML, CD30 antigen-positive individuals tended to have a more favorable prognosis than those that were negative. In reactive diseases, some plasma cells, immunoblasts, interdigitating cells, follicular center cells and histiocytes were stained positively, but not always, and with variable intensity. These results suggest that CD30 antigen is expressed in various cell lineages to some extent and may relate to cellular activation in some instances. When making the histopathologic diagnosis of HD or NHL including ALCL, CD30-positive cell should be carefully interpreted.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗

PubMed1994

Role of prostate-specific antigen and digital rectal examination in the detection of prostate cancer.

Prostate-specific antigen (PSA) is a kallikrein-like serine protease that is secreted exclusively by the epithelial cells of all types of prostatic tissue, benign and malignant. Its serum concentration is raised in men with prostatic disease including cancer. We have evaluated its usefulness in the diagnosis of prostate cancer by measuring serum PSA concentrations in 260 men aged 50 years or over. All had abnormalities at digital rectal examination (DRE) involving suspected cancer, signs and symptoms of benign prostatic hyperplasia and equivocal findings on DRE, and miscellaneous other conditions, including hematospermia, chronic prostatitis and microscopic hematuria. Transrectal prostatic needle biopsies were performed in the men with abnormal findings on DRE or elevated serum PSA (above 4 ng/ml). Serum PSA ranged from 4.0 to 9.9 ng/ml in 14 (5%) of the 260 men. Four of the men in this group (31%) who underwent prostatic biopsy had prostate cancer. Serum PSA levels greater than or equal to 10.0 ng/ml were found in 8 (3%) of the 260 men. 5 of these 8 (63%) who underwent prostatic biopsy had cancer. If DRE alone had been used to screen the men having biopsies, 4 of the 10 cancers (40%) would have been missed. If PSA alone had been used to screen these men, only 1 of the 10 cancers would have been missed. Serum PSA measurement was more reliable than DRE for detecting prostate cancer. Since these two methods do not always detect the same malignant tumor, the combined use of DRE and PSA testing affords a more complete evaluation of the prostate gland for malignant involvement.

Aged↗

PubMed1994

Effects of naftidrofuryl oxalate on microsphere embolism-induced decrease in regional blood flow of rat brain.

1. The purpose of the present study was to determine whether naftidrofuryl oxalate (naftidrofuryl), a vasodilator, is capable of improving brain regional blood flow of animals in sustained ischaemia. 2. Cerebral ischaemia was induced by injecting 900 microspheres (48 microns in diameter) into the right internal carotid artery of rats. Cerebral blood flow of brain regions was measured by a hydrogen clearance method on the 3rd, 7th and 28th days after the onset of ischaemia. Ischaemic animals were treated with naftidrofuryl, 15 mg kg-1 day-1 i.p., from the first to 28th day. 3. Microsphere-embolism caused a sustained decrease in cortical and striatal blood flow over a period of 28 days, whereas hippocampal blood flow was decreased on the 3rd day but not on the 7th or 28th day. On the 3rd day, the striatal and hippocampal but not cortical blood flow of naftidrofuryl-treated, microsphere-embolized rats was higher than untreated rats. On the 7th and 28th days, the cortical and striatal blood flow of the treated and untreated animals did not differ. 4. Brain slices from microsphere-embolized rats contained areas, which were not stained with triphenyltetrazolium chloride (TTC), to a similar degree on the 3rd, 7th and 28th days, indicating the genesis of cerebral infarction. TTC-unstained areas of microsphere-embolized rats that had received naftidrofuryl treatment were smaller than those of untreated rats on the 3rd and 7th days, but not on the 28th day. 5. The results suggest that naftidrofuryl improves cerebral circulation impaired by microsphere-induced ischaemia and this higher level of cerebral blood flow of the treated animal may account for the delayed development of cerebral infarction.

Animals↗

PubMed1994

Enantioselective pharmacokinetics of homochlorcyclizine: disposition of (+)- and (-)-homochlorcyclizine after intravenous and oral administration of racemic homochlorcyclizine to rats.

Concentrations of homochlorcyclizine enantiomers in blood, urine, and tissues of the liver, lung, kidney, brain, heart, spleen, intestine and stomach of rats after drug administration were determined by high-performance liquid chromatography on a chiral stationary phase. After intravenous administration (10 mg kg-1), homochlorcyclizine was rapidly distributed in many tissues, with the highest concentration in lung. No differences were found between enantiomers in blood concentrations. After oral administration (50 mg kg-1), the concentrations of the (+)-isomer in nearly all tissues were higher than those of the (-)-isomer. The AUC0-infinity values of the (+)- and (-)-isomers differed significantly. The absorption of racemic homochlorcyclizine from rat small intestine was not enantioselective. These results suggested that the different concentrations between enantiomers after oral administration were not caused by enantioselective absorption or distribution but rather by preferential first-pass metabolism of the (-)-isomer in the liver. The enantioselectivity of metabolism was also demonstrated by in-vitro experiments.

Administration, Oral↗

PubMed1994

Immunocytochemically demonstrated expression of epithelial membrane antigen and carcinoembryonic antigen by exfoliated urinary cells in patients with bladder cancer.

The localization of epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA) in exfoliated cells from voided urine was examined to clarify whether immunostaining for these markers is more useful than conventional cytology for diagnosis of patients with transitional cell carcinoma of the bladder. Both EMA and CEA were present more frequently in specimens from higher-grade and higher-stage tumors than lower-grade and lower-stage tumors. Cells positive for one or both of these markers were also found in specimens from cancer patients with only suspicious results by conventional cytology. In grade 1 tumors, the positive rates were 50% for EMA staining and 40% for CEA staining compared with 10% for conventional cytology. In 12 patients with cystitis, results for EMA staining and conventional cytology were all negative, whereas CEA staining proved positive in 6 patients (50%). None of 10 normal subjects with conventional cytology had positive results for EMA or CEA staining. These findings indicate that immunocytochemistry for EMA is a more useful adjunctive method than CEA staining or conventional cytology for detection of tumor cells, especially in cases of low-grade bladder cancer.

Aged↗

PubMed1994

Changes of cholecystokinin octapeptide tissue levels in rat brain following dopamine neuron lesions induced by 6-hydroxydopamine.

Cholecystokinin octapeptide sulfated (CCK8) tissue levels in several regions of the rat brain were measured by amino terminal specific radioimmunoassay following the intracerebroventricular administration of 6-hydroxydopamine (6-OHDA) to investigate the interaction between CCK8 and dopamine (DA). Pargyline and desmethylimipramine were administered 2 h before 6-OHDA injection. The levels of CCK8-like immunoreactivity in the frontal cortex, striatum, hippocampus, substantia nigra, and nucleus accumbens increased transiently on day 1 after 6-OHDA treatment. The levels in the frontal cortex, striatum and substantia nigra fell gradually to reach a subnormal level on day 7. In the nucleus accumbens, where the coexisting CCK8 and DA neurons lie, the tissue levels fell to a subnormal level on day 3. These decreased levels were unchanged until day 28. The irreversible destruction of DA neurons induced by 6-OHDA might cause drastic changes in regional CCK8-like immunoreactivity. The changes would depend on the neuromorphological differences in each structure. These results suggest that the CCK8 systems are closely related to the DA systems in several brain regions and that DA plays an important role in CCK8 release.

Animals↗

PubMed1994

Effect of first-pass metabolism on enantioselective pharmacokinetics after oral administration of (+)-, (-)- and racemic homochlorcyclizine to rats.

The enantioselective relationship between the pharmacokinetics and hepatic metabolism of homochlorcyclizine hydrochloride (HCZ) was investigated using rats. There were no significant differences in blood concentrations between the three forms after intravenous administration (5 mg/kg) of (+)-, (-)- and racemic HCZ. On the other hand, there were significant differences in the pharmacokinetics between (-)- and (+)-HCZ and between (-)- and racemic HCZ after oral administration (50 mg/kg) of these three forms. The Cmax and AUC0-infinity of (-)-HCZ were lower than those of (+)-isomer and racemate, and its CLo was clearly higher than the others. The (+)-isomer and racemate showed no significant differences in their pharmacokinetic parameters. At a lower dose (10 mg/kg), however, no enantiomeric differences were found in the pharmacokinetic parameters of (+)- and (-)-HCZ. Also examined was the cytochrome p-450-dependent-oxidative metabolism of (+)-, (-)- and racemic HCZ in vitro using rat liver 9000 x g supernatant fraction. The in vitro metabolism of (-)-HCZ was extremely fast, compared with those of the (+)-isomer and the racemate. The Vmax in vitro showed a good correlation with the CLo in vivo after oral administration (50 mg/kg) of all three forms of HCZ. In vitro study of enantiomeric inhibition of the metabolism showed that (+)-HCZ was a competitive inhibitor of (-)-HCZ metabolism, with a Ki of 6.96 microM. (-)-HCZ was also a competitive inhibitor of (+)-HCZ metabolism, with a Ki of 20.4 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1994

Expression of the DCC gene in human hematological malignancies.

Inactivation of the deleted in colorectal carcinoma (DCC) tumor suppressor gene has been reported not only in colorectal carcinoma but also in other human malignancies. In order to evaluate the role of the DCC gene in leukemogenesis, we examined DCC expression using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Expression of the DCC gene was reduced or absent in 10 of 39 (26%) patients with acute myelogenous leukemia (AML), three of 14 (29%) patients with acute lymphocytic leukemia (ALL), seven of 33 (21%) patients with chronic myelogenous leukemia (CML), three of 39 (8%) patients with myelodysplastic syndromes (MDS), and five of nine (56%) patients with overt leukemia progressed from MDS. These findings suggest that inactivation of the DCC gene contributes to some instances of leukemogenesis.

Gene Expression↗

PubMed1994

[Trigonoplasty for vesicoureteral reflux--from open surgery to endoscopic surgery].

To evaluate endoscopic trigonoplasty compared to open trigonoplasty for vesicoureteral reflux, we analyzed clinical results, complications, the use of analgesics for postoperative pain and bladder irritability and postoperative length of hospitalization. One of six patients undergoing endoscopic trigonoplasty subsequently underwent open trigonoplasty due to failure of trocar placement, therefore, 7 patients having vesicoureteral refluxy renoureteral units underwent open trigonoplasty and 5 patients with vesicoureteral reflux 7 renoureteral units underwent endoscopic trigonoplasty. Mean operative time was 143 +/- 48 minutes for open surgery and 185 +/- 54 minutes for endoscopic surgery. Vesicoureteral reflux disappeared in 8 renoureteral units but was worse in one unit after open trigonoplasty, while vesicoureteral reflux subsided in 6 units and improved in one unit from grade II to grade I after endoscopic trigonoplasty. There were no intraoperative complications after open surgery, while one patient had pneumoperitoneum due to inadequate placement of a trocar during endoscopic surgery. There were no early postoperative complications after endoscopic surgery. However, 2 patients developed hematuria after open surgery. The degree of postoperative pain and irritability following endoscopic trigonoplasty was lower than that after open trigonoplasty and analgesics were used less frequently after endoscopic surgery. The mean postoperative hospital stay was 16.7 +/- 3.2 days for open surgery and 14.4 +/- 2.9 days for endoscopic surgery. These results indicate that endoscopic trigonoplasty is a useful procedure for vesicoureteral reflux because it is minimally invasive.

Adolescent↗

PubMed1994

Appearance of spermatozoon after administration of mast cell blocker to a patient with azoospermia.

Since a close relationship has been suggested to exist between testicular disfunction and the increased mast cells in the testis, we used a mast cell blocker for the treatment of patients with idiopathic infestility. An infertile male with idiopathic azoospermia was treated with administration of a mast cell blocker, tranilast for one year. The patient was found to have sperm within his ejaculate. However, the ultimate goal of pregnancy was not achieved by the microfertilization technique. To evaluate the possible significance of this new treatment, further basic research will be needed to clarify the relationship between mast cell proliferation and impaired testicular function.

Adult↗

PubMed1994

[Sequential monitoring of various HCV-related markers in chronic hepatitis C with interferon treatment].

Interferon (IFN) which is a powerful antiviral cytokine is capable to cure approximately 40% of patients with chronic hepatitis C. We should like to know in detail whether IFN is operating enough to improve chronic hepatitis C during IFN treatment. Therefore it was evaluated what kind of HCV related markers were important to monitor the clinical course. We discussed HCV-RNA (RT-PCR, DNA probe assay) and some antibodies to HCV including our new IgM antibody to a HCV core peptide, cp14 (amino acid 5-40 of the core protein). HCV-RNA assayed by RT-PCR was considered best to monitor the therapeutic effect of IFN on chronic hepatitis C. However, as it is still not in general, IgM anti-cp14 might be an alternative in monitoring the response to IFN in patients with chronic hepatitis C.

Biomarkers↗

PubMed1994

Successful treatment of hemorrhagic cystitis secondary to cyclophosphamide chemotherapy with intravesical instillation of prostaglandin F2 alpha.

The treatment of cyclophosphamide-induced hemorrhagic cystitis is difficult. We report a successful case of severe cyclophosphamide-induced hemorrhagic cystitis treated with intravesical instillation of prostaglandin F2 alpha. A 32-year-old woman underwent high-dose cyclophosphamide conditioning before the autologous bone marrow transplantation. She developed clot retention which required continuous irrigation with normal saline. The patient had failed to respond to continuous bladder irrigation with saline and intravesical administration of 1% alum. Fifty ml of prostaglandin F2 alpha solution (1 mg in 100 ml normal saline) was instilled into the bladder, with a dwelling time of 60 minutes, three times a day for 5 days. The hematuria cleared completely 3 days after therapy. The only adverse effect was bladder spasm which was controlled with oxybutynin chloride. The success of this therapy suggests that prostaglandin F2 alpha is a safe and useful therapy for hemorrhagic cystitis secondary to cyclophosphamide chemotherapy.

Administration, Intravesical↗