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Biomedical subjects

M Miyake

Publications and source records attributed to M Miyake.

At least 73 records · Page 4Linked to original sources
PubMed2000

Immunocytochemical localization of beta-citryl-L-glutamate in primary neuronal cells and in the differentiation of P19 mouse embryonal carcinoma cells into neuronal cells.

The immunocytochemical localization of beta-citryl-L-glutamate (beta-CG) in primary neuronal cells and in the differentiation of P19 cells was examined. 1: Cells with the morphological features of neurons in the primary culture were specifically stained with the anti-beta-CG antibody both in neurites and in the cell body. 2: The neuronal cells differentiated from P19 cells were distinctly stained with the anti-beta-CG antibody both in neurites and in the cell body, while the non-neuronal cells were not. 3: The concentration of beta-CG was low in the P19 cells, but increased significantly with the differentiation of P19 cells into neurons. It was shown that beta-CG was localized exclusively in neurons. These findings suggest that beta-CG plays functional roles in the differentiation and growth of neuron.

Animals↗
PubMed2000

Immunohistochemical and chemical changes of beta-citryl-L-glutamate in the differentiation of bovine lens epithelial cells into lens fiber cells.

Beta-citryl-L-glutamate (beta-CG) concentration was determined by HPLC during the differentiation of bovine lens epithelial cells into lens fiber cells in culture. beta-CG increased from 1 to 4 weeks of culture and then decreased slightly, while alpha-crystallin, a marker of lens cell differentiation, increased rapidly 4 weeks after the culture and continued to increase gradually until week 11. In addition, the localization of beta-CG was immunohistochemically examined using anti-beta-CG antibody. Cells around lentoid bodies were stained with anti-beta-CG antibody, whereas cells in the bodies were stained strongly with anti-gamma-crystallin antibody. These findings suggest that beta-CG accumulated immediately before the differentiation of the bovine lens epithelial cells into lens fiber cells and may play a role in regulating the differentiation of lens cells.

Animals↗
PubMed2000

Anti-mouse sperm monoclonal antibody, A-1, inhibits sperm capacitation, acrosome reaction and calcium influx into spermatocytes.

An anti mouse sperm monoclonal antibody (A-1) inhibited sperm penetration into the egg zona pellucida and bound to an acrosomal area of sperm. In this study, we examined whether or not the antibody affects the sperm capacitation and the acrosome reaction. Sperm were incubated in modified Krebs-Ringer bicarbonate medium in the presence or absence of the antibody. The capacitation of sperm was assessed by chlortetracycline fluorescence pattern assay. The percentage of capacitated sperm did not increase in the presence of antibody, but increased time-dependently in its absence. The acrosome reaction of the capacitated sperm was induced by the addition of ionophore. The ionophore, however, failed to induce the reaction in the presence of the A-1 antibody. Next, the calcium influx into spermatocytes was examined. The capacitated sperm, preloaded with Fura-2, were treated with ionomycin in the presence or absence of the A-1 antibody. The influx of calcium ions into capacitated spermatozoa was also inhibited by the antibody. Thus a monoclonal antibody, A-1, inhibited the sperm capacitation, acrosome reaction and calcium influx into spermatocytes.

Acrosome Reaction↗
PubMed2000

Inhibition of in vitro fertilization of mouse gametes by sulfated sialic acid polymers.

The effect of sialic acid (N-acetyl neuraminic acid), sialic acid dimer, sialic acid polymers (colominic acid) and sulfated colominic acid on the activity of hyaluronidase, on the dispersion of cumulus cells by mouse sperm and on in vitro mouse fertilization (sperm penetration of zona pellucida) were evaluated. Bovine testicular hyaluronidase activity was significantly inhibited by colominic acid and sulfated colominic acid, but not by sialic acid and its dimer. The dispersion of cumulus cells from eggs by mouse sperm was also inhibited by colominic acid and sulfated colominic acid. In vitro fertilization of mouse gametes was inhibited by sulfated colominic acid. The IC50 value of sulfated colominic acid-induced inhibition of fertilization was 0.3 mg/ml (ca. 0.9 mM). The value changed from 0.9 mM for cumulus-surrounded egg to 1.5 mM for cumulus free-egg. On the other hand, colominic acid showed little or no inhibitory effect on mouse in vitro fertilization at 0.5 mg/ml (ca. 1.6 mM). This antifertility activity by sulfated colominic acid did not appear to be due to an effect on sperm motility or on the oocytes. These results suggest that (1) the cumulus cells surrounding the eggs were dispersed by sperm hyaluronidase, (2) hyaluronidase was inhibited by colominic acid and by sulfated colominic acid, (3) sulfated colominic acid inhibits sperm penetration of zona pellucida by the inhibition of hyaluronidase and/or some enzymes required for mouse gametes fertilization.

Animals↗
PubMed2000

Phosphotransacetylase as a key factor in biological production of polyhydroxybutyrate.

Phosphotransacetylase (Pta) catalyzes the reversible conversion of acetyl-coenzyme A (CoA) to acetyl phosphate. Polyhydroxybutyrate (PHB) synthase and accumulation were compared between a Pta-deficient mutant and the wild-type Escherichia coli, which were transformed with pAE100, coding for 3-ketothiolase, NADPH-dependent acetoacetyl-CoA reductase, and PHB synthase from Ralstonia eutropha. During the growth period, PHB synthase activity in the Pta-deficient mutant was lower than that in the wild type. PHB accumulation in the Pta-deficient mutant, however, was higher than that in wild-type cells grown in Luria-Bertani (LB) medium containing 1% glucose (high C:N ratio). The Pta-deficient mutant showed PHB accumulation even in LB medium (low C:N ratio), whereas wild-type cells showed no PHB accumulation. These data suggest the activation of PHB synthase by acetyl phosphate that is synthesized by Pta. A decrease in Pta activity probably causes some increase in acetyl-CoA as substrate for the PHB synthesis pathway, resulting in increased PHB accumulation.

Acyltransferases↗
PubMed2000

Polyhydroxybutyrate production from carbon dioxide by cyanobacteria.

Genetic characterization and enhancement of polyhydroxybutyrate (PHB) accumulation in cyanobacteria were investigated for efficient PHB production from CO2. The genome DNAs in the PHB-accumulating strains Synechococcus sp. MA19 and Spirulina platensis NIES46 retained the highly homologous region to phaC of Synechocystis PCC6803, whereas low homology was detected in the nonaccumulating strains Synechococcus sp. PCC7942 and Anabaena cylindrica NIES19. Synechococcus sp. MA19, which accumulates PHB up to 30% of dry cell weight from CO2 as the sole carbon source, was mutated by insertion of transposon Tn5 to enhance the PHB accumulation. Genetic and physiological analysis of the mutant indicated that decreased phosphotransacetylase activity could trigger an increase of acetyl coenzyme A leading to enhancement of PHB accumulation. PHB synthase in Synechococcus sp. MA19 was probably attached to thylakoid membrane since PHB granules were associated with pigments. A genetically engineered cyanobacteria retaining soluble PHB synthase from Ralstonia eutropha accumulated pigment-free PHB granules, which is an advantage for the purification of PHB.

Acyltransferases↗
PubMed2000

The K-ras gene regulates vascular endothelial growth factor gene expression in non-small cell lung cancers.

Tumor angiogenesis is an essential step for tumor cell growth, progression and metastasis. Vascular endothelial growth factor (VEGF) is mitogen specific for endothelial cells, and therefore is believed to play a key role in tumor angiogenesis. However, the mechanisms underlying the regulation of VEGF expression remain virtually unknown and the only major regulator of VEGF expression has been reported to be hypoxia. Recently, it was reported that a mutant p53 in#duced the expression of VEGF mRNA, and that wild-type p53 down-regulated endogenous VEGF mRNA levels. In contrast, it has also been reported that mutant ras oncogenes were associated with the marked up-regulation of VEGF in transformed epithelial cells. Based on these results, we performed a retrospective study of the p53 and K-ras genes status and VEGF gene expression in the tumor tissues from 181 patients with non-small cell lung cancer using SSCP, sequencing, RT-PCR and immunohistochemical techniques. Forty-six carcinomas (25.4%) were evaluated as having high VEGF expression, and 135 tumors (74.6%) had low VEGF expression. Of the 181 primary NSCLC studied, 63 carcinomas (34.8%) contained mutations of p53, whereas only 14 carcinomas (7.7%) had mutations of K-ras. There were no significant relationships between VEGF expression and p53 status or each mutant exon of p53. In contrast, a significant difference was found between VEGF expression and K-ras status. Of the 14 tumors with mutant K-ras genes, 7 cases (50.0%) had high VEGF expression whereas only 39 of the 167 tumors with wild-type K-ras (23.4%) had high VEGF expression (p=0.0278). The mean VEGF conservation rate for the 14 tumors with mutant K-ras genes was 0.77+/-0.58 and the rate of the 167 tumors with wild-type K-ras genes was 0.49+/-0.46 (p=0. 0350). Moreover, the overall survival rate of patients with high VEGF expression was lower than patients with low VEGF expression (45.7% vs 60.7%, p=0.0419). On the other hand, there was no significant difference in the overall survival rate between patients with a mutant p53 and those with a wild-type p53; there was also no difference in the overall survival between patients with a mutant K-ras and those with a wild-type K-ras. The Cox regression model analysis indicated that three variables, VEGF status, K-ras status and nodal status, were found to be significant indicators for prognosis (p=0.0236, p=0.0172 and p<0.0001, respectively). Our data suggest that a high expression of VEGF in lung cancer may be associated with a poor prognosis. This may be a clue to improving lung cancer diagnoses and therapies aimed at inhibiting tumor angiogenesis due to VEGF.

Adult↗
PubMed2000

Significance of integrin alpha5 gene expression as a prognostic factor in node-negative non-small cell lung cancer.

The integrin family plays a major role in complex biological events such as differentiation, development, wound healing, and the altered adhesive and invasive properties of tumor cells. Integrin (alpha5beta1 is a classical fibronectin receptor, and it has been known as a tumor suppressor gene because tumor cells overexpressing alpha5beta1 are less tumorigenic than their parent cells. However, this finding conflicts with some recent data that suggests that the emergence of alpha5beta1 expression correlates with the tumor progression. We, therefore, investigated the expression of alpha5beta1 integrin in 20 lung cancer cell lines by flow cytometric analysis and in 88 node-negative non-small cell lung cancers (NSCLCs) by RT-PCR and immunohistochemical assays to determine the significance of this prognostic factor. In the 20 lung cancer cell lines, 8 (40.0%) cell lines strongly expressed integrin alpha5, 3 (15.0%) cell lines had moderate or weak alpha5 expression, and the remaining 9 (45.0%) cell lines expressed no integrin alpha5. In the 88 node-negative NSCLC patients, 44 samples (50.0%) were evaluated as having integrin alpha5 overexpression, and the integrin alpha5 expression was significantly associated with the status of differentiation and the age of the patients (P = 0.0379 and 0.0312, respectively). In the node-negative patients, the overall survival rate for patients with integrin alpha5 overexpressed tumors was significantly worse than for those individuals whose tumors had normal integrin alpha5 expression (P = 0.016).

Aged↗
PubMed2000

[Investigation of the resolution and count recovery coefficients of a whole-body PET scanner (Shimadzu SET-2400W) in 2D and 3D mode image].

UNLABELLED: We measured the resolution and count recovery coefficients (RC) of the SET-2400W whole-body PET scanner (Shimadzu Co., Japan) in the 2D and 3D clinical modes. METHOD: The 3D images were reconstructed by using the full 3D image reconstruction method (3-D reprojection algorithm: 3DRP) and the Fourier rebinning method (FORE). The 2D images were reconstructed with conventional filtered back-projection method (FBP). The measurements of resolution and recovery coefficient were according to JRIA (Japan Radioisotope Association) protocols. RESULTS: The transaxial resolutions of all methods were better than 7 mm FWHM at a radius of 10 cm with 1.25 cm-1 cutoff frequency. The average slice width of 2D FBP, 3DRP and FORE are 5.8 mm, 8.0 mm and 6.8 mm respectively at the center of transaxial field of view. The RC values were measured in a range from 10 mm to 27 mm at 6 cm from the center with the cylindrical and spherical hot area phantoms. In all methods, RC values at 27 mm diameter were nearly 1.0 in both type of hot area. RC values at 10 mm diameter in 2D FBP, 3DRP and FORE of cylindrical hot area were 0.69, 0.72, 0.73 and those of spherical hot area were 0.52, 0.51, 0.53 respectively. CONCLUSION: At the SET-2400W, resolution and recovery coefficient of 3D mode image under the clinical mode showed the value which did not differ from the 2D mode image.

Image Processing, Computer-Assisted↗
PubMed2000

Thrombopoietin enhances neutrophil production by bone marrow hematopoietic progenitors with the aid of stem cell factor in congenital neutropenia.

We examined the effects of granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), and thrombopoietin (TPO), alone or in combination, on the generation of neutrophils by bone marrow (BM) cells from three patients with severe congenital neutropenia (SCN) through the use of a serum-deprived liquid culture system. Synergistic effects of G-CSF and SCF on the neutrophil production by BM CD34+CD38+c-kit+ cells were observed in SCN patients as well as in normal controls. The addition of TPO to the culture containing G-CSF and SCF further augmented the growth of neutrophils in the two groups. Single-cell culture experiments revealed that the three-factor combination caused increases in both the number and size of neutrophil colonies compared with G-CSF + SCF in normal BM cells, whereas only a significant increment in the colony size was observed in SCN patients. Even in the presence of SCF or SCF + TPO, the concentrations of G-CSF necessary for the substantial production of neutrophils by CD34+CD38+c-kit+ cells were higher in two patients compared with the levels obtained by normal control cells. In addition, TPO did not accelerate the maturation of neutrophilic cells supported by G-CSF + SCF. When BM CD34+CD38-c-kit+ cells were targeted, the addition of TPO to the culture containing G-CSF and SCF was required for significant neutrophil colony growth in the two groups. These results suggest that TPO enhances the G-CSF-dependent neutrophil production with the aid of SCF in this disorder.

ADP-ribosyl Cyclase↗
PubMed2000

[Treatment and prognosis of children with relapsed non-Hodgkin's lymphoma--a report from CCLSG-NHL 890 Study. Children's Cancer and Leukemia Study Group (CCLSG)].

To address the issue of salvageability in relapsed children with NHL who had all received the same frontline therapy, we retrospectively studied the treatment response and the outcome of 27 children who relapsed following the CCLSG-NHL890 protocol. The reinduction rates and 3-year survival rates (mean +/- SD) were as follows: lymphoblastic lymphoma (LB, n = 9), 44% & 17 +/- 14%; leukemia lymphoma syndrome (LLS, n = 8), 25% & 0%; large cell lymphoma (LC, n = 3) 100% & 67 +/- 27%; Burkitt's lymphoma (B, n = 7) 0% & 0%. Thus, the salvageability of LC lymphoma was good, but the outcome of Burkitt's lymphoma was very poor. CCLSG-NHL960 protocol for LB lymphomas and intensive multiagent regimens for LC lymphomas produced favorable response rates, but the effect of the high-dose Ara-C regimen for Burkitt's lymphoma was not determined. The initial stages of the disease seemed to be associated with the patient outcome: the outcome of the patients in stage IV was inferior to that of patients in stages II or III. Other clinical variables, such as relapse sites, relapse time and BM rescue did not affect the patients' outcome.

Adolescent↗
PubMed2000

[Chemotherapy with nedaplatin for an oral floor cancer patient undergoing chronic hemodialysis].

Since pharmacokinetics in patients undergoing hemodialysis differs from that in patients with normal renal function, the administration of chemotherapeutic drugs to a patient with renal failure should be sufficiently considered beforehand to avoid adverse effects. A case of carcinoma of the oral floor in a 69 year-old male receiving ongoing hemodialysis due to chronic renal failure is reported. Chemotherapy was given using nedaplatin and 5-FU; surgery was performed as well. To investigate the pharmacokinetics and determine the optimal dose of nedaplatin during ongoing hemodialysis, the concentrations of free-platinum and total-platinum in serum from the patient were measured periodically. The patient received approximately one half of the dose of nedaplatin for a patient with normal renal function. Hemodialysis was performed 3 hours after the start of the administration of nedaplatin and continued for 4 hours. As a result, the maximum concentration of nedaplatin (Cmax) was about one half of the normal range. However, the value of the area under the blood concentration time curve (AUC), which is considered a target index of administration, was close to the value in patients with normal renal function. No severe side effects were observed after chemotherapy. A Grade IV pathological effect on Ohboshi-Shimosato's classification was obtained from the specimen after radical resection.

Aged↗
PubMed2000

Mechanical tensile properties of the aortic wall in the premature rat exposed to the microgravity environment during space flight for 16 days.

Under microgravity environment, blood shifts headward and thereafter decrease in volume to adapt to the environment, which could affect cardiovascular hemodynamics and their regulatory mechanisms. Baroreceptor sensitivity is known to be reduced in newborn animals and to gradually increase with development. The baroreceptor is a stretch receptor; therefore its function is closely related to the rheological properties and fine structure of the aortic wall in which the baroreceptor lies. The mechanical and histological properties could be altered under microgravity conditions in the process of development with change in circulatory function. In the present study, we investigated the mechanical tensile characteristics and histological structure of the aortic wall in the proximal thoracic aorta of premature rats bred in the microgravity environment of the space shuttle for 16 days.

Animals↗
PubMed1999

Anti-tumor promoting activity of polyphenols from Cowania mexicana and Coleogyne ramosissima.

Chemical investigation on polyphenol-rich fractions of Cowania mexicana and Coleogyne ramosissima (Rosaceae) which showed significant inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), has led to the characterization of 10 compounds including C-glucosidic ellagitannin monomers and dimers from the former plant, and 17 polyphenols including flavonoid glycosides from the latter. The effects of individual components and their analogues with related structures on the TPA-induced EBV-EA activation were then evaluated. Among the compounds isolated from C. mexicana, two C-glucosidic ellagitannins, alienanin B and stenophyllanin A and a nitrile glucoside (lithospermoside), and among the constituents from C. ramosissima, two flavonoid glycosides, isorhamnetin 3-0-beta-D-glucoside and narcissin were revealed to possess strong inhibitory effects on EVB-EA activation, the potencies of which were either comparable to or stronger than that of a green tea polyphenol, (-)-epigallocatechin gallate. These polyphenols except for nitrile glucoside, which was not tested owing to an insufficient amount, were also found to exhibit anti-tumor promoting activity in two-stage mouse skin carcinogenesis using 7,12-dimethylbenz[a]anthracene (DMBA) and TPA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Cisplatin in combination with irinotecan in the treatment of patients with malignant pleural mesothelioma: a pilot phase II clinical trial and pharmacokinetic profile.

BACKGROUND: The purpose of this study was to assess the efficacy and toxicity of a combination of cisplatin and irinotecan (CPT-11) in the treatment of patients with malignant pleural mesothelioma and to characterize the pharmacokinetic profiles of CPT-11 and its active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38). METHODS: Fifteen previously untreated patients with malignant pleural mesothelioma were treated with cisplatin (60 mg/m2 on Day 1) and CPT-11 (60 mg/m2 on Days 1, 8, and 15) administered intravenously and followed by a 1-week rest period. The course of treatment was repeated every 28 days. After intravenous administration, the levels of CPT-11 and SN-38 in the plasma and pleural fluid were determined for each histologic subtype of mesothelioma. RESULTS: All patients were evaluable for response and toxicity. Four partial responses (response rate of 26.7%) with a median response duration of 25.9 weeks and 2 regressions of evaluable disease (overall response rate of 40%) were observed. The median survival time after chemotherapy was 28.3 weeks, and the median time to treatment failure was 22.1 weeks. The 1-year survival rate for all patients was 38.5%. Toxicity was well tolerated, and there were no treatment-related deaths. World Health Organization Grade 3 leukopenia occurred in 3 patients (20%), and Grade 1 or 2 diarrhea occurred in 3 patients (20%). There was no excess toxicity in patients with large pleural effusions compared with those with no pleural effusions. CPT-11 and SN-38 were detected in the pleural fluid 1 hour after intravenous administration. The maximum concentrations of CPT-11 and SN-38 in the pleural fluid were 36.5% and 75.8%, respectively, of the corresponding plasma values. CONCLUSIONS: The combination of cisplatin and CPT-11 had definite activity against malignant pleural mesothelioma and was well tolerated. The intravenous administration of CPT-11 produced adequate distribution of CPT-11 and its active metabolite SN-38 into the pleural fluid and allowed a higher concentration of the more active SN-38 to make contact with mesothelioma cells in the thoracic cavity. These results warrant further clinical evaluation of this combination chemotherapy for the treatment of malignant pleural mesothelioma in a confirmatory Phase II trial.

Adult↗
PubMed1999

Haemophilus influenzae has a GM1 ganglioside-like structure and elicits Guillain-Barré syndrome.

The authors report a patient with an axonal Guillain-Barré syndrome (acute motor axonal neuropathy) associated with anti-GM1 antibody after Haemophilus influenzae infection. The result of ELISA inhibition studies and cytochemical staining with cholera toxin suggest the presence of a GM1-like structure on the surface of H. influenzae isolated from the patient. A particular strain of H. influenzae may have a GM1-like structure and may elicit an axonal Guillain-Barré syndrome.

Adult↗