Search PubMed⌕ Search

Biomedical subjects

M Matsuo

Publications and source records attributed to M Matsuo.

At least 37 records · Page 2Linked to original sources
PubMed2002

Evidence of oncotic cell death and DNA fragmentation in human hypertrophic chondrocytes in chondro-osteophyte.

OBJECTIVE: To investigate the population and morphology of in situ terminal deoxynucleotidyle transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) stain positive non-apoptotic chondrocytes in hypertrophic zone of human chondro-osteophytes. MATERIALS AND METHODS: Chondro-osteophytes from osteoarthritic patients were obtained at joint replacement surgery. Apoptosis was verified by light microscopic examination of Safranin O stained sections and TUNEL stain. TUNEL staining was also performed on hydrophilic resin embedded semi-thin and ultra-thin sections combined with the treatment with streptavidin-gold conjugates, observed by light microscopy with silver enhancement technique (TUNEL-LM with SE) and transmission electron microscopy (TUNEL-TEM) respectively for the simultaneous evaluation of cellular structure and DNA fragmentation. RESULTS: In paraffin embedded sections (N=18), 31.5+/-6.1% of cells in the hypertrophic zone were TUNEL positive, but only 3.8+/-1.2% cells in this zone showed apoptotic appearances with cell shrinkage and nuclear condensation. Both in TUNEL-TEM and TUNEL-LM with SE, gold particles, which indicate DNA fragmentation, were observed within the nucleus of morphologically apoptotic chondrocytes, as well as of disintegrated, swollen chondrocytes. CONCLUSIONS: In human chondro-osteophytes, hypertrophic chondrocytes might die by oncotic cell death with DNA fragmentation, as well as apoptosis.

Adult↗
PubMed2002

The inorganic and organic characters for predicting bioconcentration on wide variety of chemicals in fish.

The applicability of Fujita's inorganic (i) and organic (o) characters as descriptors for predicting bioconcentration factor (BCF) in fish was investigated with a wide variety of organic chemicals. Among 612 BCF data recently released by National Institute of Technology and Evaluation (NITE), the values for the chemicals with a molecular weight of less than 600 and the 1-octanol/water partition coefficient (log P) of less than six were extracted and analyzed. By applying theoretically derived model equation, a good relationship between these BCF and each Fujita's sigma i: sigma o was established. Statistical analyses and model validations revealed that the estimations of our approach were very excellent. More precise predictions were attained than those by using other published models, especially, for chemicals such as disperse dye having hetero atoms.

Animals↗
PubMed2001

Photoswitching of intramolecular magnetic interaction using diarylethene with oligothiophene pi-conjugated chain.

Diarylethenes having two nitronyl nitroxide radicals at both ends of the molecule with oligothiophene spacers were synthesized. The diradicals underwent photochromic reactions upon alternate irradiation with UV and visible light. ESR spectra of the diradicals reversibly changed with the photochromism. The magnetic interaction between spins through oligothiophene spacers was stronger than that through oligophenylene spacers, and the photochromic reactivity of the diradical diarylethenes with oligothiophene spacers was much reduced. The difference of the exchange interaction between open- and closed-ring form isomers was estimated to be more than 150-fold.

Journal Article↗
PubMed2001

Additional gene therapy with Ad5CMV-p53 enhanced the efficacy of radiotherapy in human prostate cancer cells.

PURPOSE: The aim of this study was to investigate the efficacy of combination therapy of ionizing radiation (IR) and adenoviral p53 gene therapy and to evaluate its molecular mechanisms. METHODS AND MATERIALS: Two human prostate cancer cell lines, DU145 and PC-3 cells, containing different types of p53 gene mutations, were investigated. The recombinant adenovirus vector containing the wild-type p53 gene (Ad5CMV-p53) was used for this study. Cells were irradiated (in 0, 2, 4, and 6 Gy, 300 cGy/min) and after 12 h of irradiation, the cells were infected with various doses of Ad5CMV-p53 (0-40 multiplicity of infection [MOI]). Cytotoxicity was determined by clonogenic assay. The molecular mechanisms were evaluated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), apoptotic cell detection, and cell cycle analysis. RESULTS: The cell growth inhibition in DU145 (p53-mutated) cells by IR was strongly enhanced by additional Ad5CMV-p53 infection in a viral dose-dependent manner. In DU145 cells, IR alone induced minimal p53 mRNA expression. However, IR combined with Ad5CMV-p53 infection stimulated significant increase in p53 mRNA expression supplemented with Bax and p21 mRNA expressions. In PC-3 (p53-null), IR induced Bax and p21 mRNA expression, while the combination effects were observed in p53, Bax, and p21 mRNA expression. Apoptotic cell deaths were rarely observed after IR alone (DU145: 3%, PC-3: 5%). However, after combination therapy, the proportion of apoptotic cells greatly increased (sevenfold in DU145 cells, and twice in PC-3 cells). G1 cell cycle arrest was observed after Ad5CMV-p53 infection and the combination in both cell lines. CONCLUSION: In this study, we demonstrated that the combination of IR and Ad5CMV-p53 gene therapy resulted in remarkable synergistic effects in human prostate cancer cells. This combination therapy could be one of the optimal treatment strategies for radioresistant prostate cancer.

Adenoviridae↗
PubMed2001

Effect of FR194738, a potent inhibitor of squalene epoxidase, on cholesterol metabolism in HepG2 cells.

(E)-N-ethyl-N-(6,6-dimethyl-2-hepten-4-ynyl)-3-[2-methyl-2-(3-thienylmethoxy)propyloxy]benzylamine hydrochloride (FR194738) inhibited squalene epoxidase activity in HepG2 cell homogenates with an IC50 value of 9.8 nM. In the study using intact HepG2 cells, FR194738 inhibited cholesterol synthesis from [14C]acetate with an IC50 value of 4.9 nM, and induced intracellular [14C]squalene accumulation. On the other hand, the 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitor simvastatin reduced both cholesterol and squalene synthesis from [14C]acetate. Incubation with simvastatin for 18 h produced increases in HMG-CoA reductase activity in HepG2 cells, which was related to the degree of reduction in cholesterol synthesis. The HMG-CoA reductase activity increased by 13- and 19-fold at the concentrations of simvastatin that inhibited cholesterol synthesis by 65% and 82%, respectively. In contrast, FR194738 did not increase HMG-CoA reductase activity at the concentrations that inhibited cholesterol synthesis by 24% and 69%, and moderate increase (4.6-fold) was observed at the concentration that inhibited cholesterol synthesis by 90%. These results suggest that non-sterol metabolite(s) derived from mevalonate prior to the squalene epoxidation step in the cholesterol synthetic cascade have a regulatory role in the suppression of HMG-CoA reductase activity. We speculate that FR194738 inhibits cholesterol synthesis with a minimal change of the regulator(s) and would be highly effective in the treatment of hypercholesterolemia.

Benzylamines↗
PubMed2001

Drug-resistant human bladder-cancer cells are more sensitive to adenovirus-mediated wild-type p53 gene therapy compared to drug-sensitive cells.

We investigated the therapeutic potential and molecular mechanism of adenovirus-mediated wt p53 gene therapy for drug-resistant human bladder cancers. KK47, a human bladder-cancer cell line, along with the drug-resistant sublines KK47/DDP10, KK47/DDP20 (cisplatin-resistant) and KK47/ADM (doxorubicin-resistant) were used for the experiments. All 4 KK47 cell lines had genetically normal p53 genes. Using an in vitro cytotoxicity assay, the drug-resistant cell lines were more sensitive to Ad-CMV-p53 cell killing than the KK47 parental cell line. Ad-CMV-p53 induced higher levels of p53 protein and mRNA in the drug-resistant cell lines than in the parental cell line and, consequently, higher levels of p21 and Bax mRNA, which resulted in higher percentages of G(1) cell-cycle arrest and apoptosis. The higher efficiencies of adenoviral gene transfer in the drug-resistant cell lines were confirmed by X-gal staining after infection with Ad-CMV-beta-gal. In conclusion, adenovirus-mediated wt p53 gene therapy was more effective in the drug-resistant bladder-cancer cell lines than in the drug-sensitive bladder-cancer cell line.

Adenoviridae↗
PubMed2001

Atypically enhancing hepatic cavernous hemangiomas: high-spatial-resolution gadolinium-enhanced triphasic dynamic gradient-recalled-echo imaging findings.

We retrospectively investigated the appearance and frequency of atypically enhancing cavernous hemangiomas with high-spatial-resolution (512x224 matrix) gadolinium-enhanced triphasic dynamic gradient-recalled-echo (GRE) MR images. Images of 132 hepatic cavernous hemangiomas (ranging in size from 4 to 72 mm; mean size 17.2 mm) in 95 patients (42 men and 53 women; age range 25-85 years; mean age 54 years) were retrospectively reviewed by two independent radiologists. Forty (30%) of 132 lesions atypically enhanced. Smaller hemangiomas (< or =15 mm) more frequently (29%) showed early entire enhancement with or without arterio-portal shunting in the hepatic arterial-dominant phase ( p<0.001); most of them showed hyperintense complete fill-in in the equilibrium phase and were readily characterized. "Bright dot" or minimal peripheral enhancement in the equilibrium phase was seen in a small number of lesions (6% each). With T2-weighted images, 130 (98%) lesions showed moderately to very high signal intensity and only 2 (2%) with minimal peripheral enhancement showed hyperintensity of slight degree. The high-spatial-resolution dynamic GRE images clearly revealed minute enhancement characteristics of hemangiomas. Although moderately to very high signal intensity with T2-weighted MR images is informative for the diagnosis of most cavernous hemangiomas, when a lesion shows minimal peripheral enhancement in the equilibrium phase and hyperintensity of slight degree with T2-weighted images, further follow-up or biopsy may be warranted to discriminate hypovascular metastases.

Adult↗
PubMed2001

Dissection and weighing of accessory sex glands after formalin fixation, and a 5-day assay using young mature rats are reliable and feasible in the Hershberger assay.

The rodent Hershberger assay has been used predominantly by the pharmaceutical industry to evaluate androgenic and antiandrogenic chemicals for potential therapeutic use. However, this assay has not yet been formally validated and standardized for use in toxicology testing. There are many variations in the protocol used for this assay. The weight of androgen-dependent tissues is a definitive endpoint in the Hershberger assay. To find out the reliable assay protocol with feasibility, although many possible factors may affect assay reliability, the present study consist of a series of three separate experiments focused on method of dissection and weighing of accessory sex glands (ASGs: ventral and dorso-lateral prostate, seminal vesicles together with coagulating glands, and Cowper's glands), animal age and number of doses. Furthermore, male pubertal assay, an alternative to the Hershberger assay, was also examined its reliability. Experiment 1 explored whether reliably accurate ASG weights can be obtained after formalin fixation. The ASGs were collected from castrated male rats (11 weeks of age) treated daily with corn oil, or testosterone propionate (TP, 0.25 mg/kg/day, s.c.) and p,p'-DDE (0 or 100 mg/kg/day, p.o.) for 5 days. One day after the final treatment, the ASGs were removed carefully and weighed separately, and then fixed overnight in a 10% neutral-buffered formalin and weighed again. After that, the tissues were dried overnight in an oven and weighed again. A high correlation between fresh and fixed tissue weights, and a high correlation between fixed and dried tissue weights were noted. The changes in the tissue weight due to fixation were marginal and were proportional to the fresh weights of the individual tissue. Standard deviation of the fixed tissue weight in each group and the magnitude of responses to TP or p,p'-DDE in fixed tissues were equivalent to those in fresh or dried tissues. These findings indicate that formalin fixation does not interfere with interpretation of assay results, and this procedure was used in the subsequent experiments. Experiments 2 and 3 explored whether animal age or treatment duration altered assay sensitivity. In Experiment 2, antiandrogenic effect of p,p'-DDE (100 mg/kg/day) was detected after 5-and 10-day treatment irrespective of animal age (7 vs 11 weeks). In Experiment 3, antiandrogenic effects of flutamide (1 and 10 mg/kg/day) and p,p'-DDE (10 and 100 mg/kg/day) were compared between two different protocols, the 10-day assay using peripubertal rats and the 5-day assay using young mature rats. Results demonstrated that both protocols could significantly detect antiandrogenic effects of flutamide and p,p'-DDE. These findings demonstrate that (1) dissection and weighing of ASGs after formalin fixation is reliable in the Hershberger assay, (2) when this procedure is used, the 5-day Hershberger assay using young mature rats, expected to be more feasible assay than the 10-day assay using peripubertal rats, is also reliable as well as the 10-day assay using peripubertal rats. Furthermore, we confirmed that male pubertal assay with use of dissection and weighing of fixed tissues also reliable.

Androgens↗
PubMed2001

Alternative splicing regulates the endoplasmic reticulum localization or secretion of soluble secreted endopeptidase.

A subfamily of zinc metalloproteases, represented by Neutral endopeptidase (EC ) and endothelin-converting enzyme, is involved in the metabolism of a variety of biologically active peptides. Recently, we cloned and characterized a novel member of this metalloprotease family termed soluble secreted endopeptidase (SEP), which hydrolyzes many vasoactive peptides. Here we report that alternative splicing of the mouse SEP gene generates two polypeptides, SEP(Delta) and SEP. After synthesis, both isoforms are inserted into the endoplasmic reticulum (ER) as type II membrane proteins. SEP(Delta) then becomes an ER resident, whereas SEP, which differs by only the presence of 23 residues at the beginning of its luminal domain, is proteolytically cleaved by membrane secretase(s) in the ER and transported into the extracellular compartment. An analysis of the chimeric proteins between SEP(Delta) and bovine endothelin-converting enzyme-1b (bECE-1b) demonstrated that the retention of SEP(Delta) in the ER is mediated by the luminal domain. In addition, the dissection of the chimeric bECE-1b/SEP insertion showed that its insertion domain is obviously responsible for its secretion. A series of mutagenesis in this region revealed that the minimal requirement for cleavage was found to be a WDERTVV motif. Our results suggest that the unique subcellular localization and secretion of SEP proteins provide a novel model of protein trafficking within the secretory pathway.

Alternative Splicing↗
PubMed2001

Age-related changes in oxidative damage to lipids and DNA in rat skin.

Skin is a tissue exposed most frequently to oxidative stress from the environment in daily life. Age-related changes of oxidative damage and antioxidant enzyme activity in the skin were examined in male Fischer 344 rats aged 6 to 30 months. The contents of phosphatidylcholine hydroperoxide (PCOOH) and thiobarbituric acid-reacting substances (TBARS) increased linearly with age. The content of cholesterol hydroperoxide increased until 24 months of age and then decreased. The content of 8-oxo-2'-deoxyguanosine (8-oxodG) increased gradually with age, and was significantly higher at 30 months of age than at 6 months of age. Superoxide dismutase activity tended to decrease with age. The activities of catalase and glutathione peroxidase showed no changes with age. We examined the effect of dietary restriction on the accumulation of oxidative damage in rat skin. The increase in PCOOH content in the skin of dietary-restricted rats was suppressed until 30 months of age. The TBARS and cholesterol hydroperoxide contents in the skin of dietary-restricted rats were significantly lower than in the skin of ad libitum-fed rats, while the 8-oxodG content was somewhat lower in the dietary-restricted rats than the ad libitum-fed rats. These results indicate that oxidative damage to the lipids and DNA in rat skin increases with age and that dietary restriction delays the accumulation of oxidative damage in skin.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Studies on intake of heavy metals by Bradybaena similaris, land snails, by XAFS measurement.

We have applied XAFS in order to determine both the chemical form and the place where heavy metals are stored in cultivated land snails. From Cu and Zn XANES spectra, the shells showed similar patterns as those of soft tissues and not like carbonates. This indicates that heavy metals are not completely taken into carbonate structures but are present within organic components in the shells. In addition, Cu XANES spectra of the samples showed low absorption edge-energy in the order of hepatopancreas, mantle, body, and shell. By comparing samples with standard reagents, each of which has only S- or O-ligand, it was found that the metals in hepatopancreas exist mostly as S-bound chemical components. To quantify the relative abundance of S-bound chemical component, partial least-squares (PLS) regression was applied. The PLS result indicated that for Cu, S-bound compound was higher in the order of hepatopancreas > mantle > body >shell.

Animals↗
PubMed2001

47,XXX male: A clinical and molecular study.

We report a 53-year-old Japanese male with a 47,XXX karyotype. His clinical features included hypoplastic scrotal testes (4 ml bilaterally), normally formed small penis (3.8 cm), relatively poor pubic hair development (Tanner stage 3), gynecomastia, age-appropriate male height (159.1 cm), and mental retardation (verbal IQ of 56). Serum testosterone was markedly reduced (0.6 nmol/L). A needle biopsy showed severe testicular degeneration. FISH analysis revealed complex mosaicism consisting of (1) 47,XXX cells with a single copy of SRY (n = 177), two copies of SRY (n = 3), and no SRY (n = 1); (2) 46,XX cells with a single copy of SRY (n = 9) and no SRY (n = 3); (3) 45,X cells with no SRY (n = 5); and (4) 48,XXXX cells with a single copy of SRY (n = 1) and two copies of SRY (n = 1). PCR analysis showed the presence of Yp portion with the breakpoint between DYS264 and AMELY. Microsatellite analysis demonstrated three alleles for DMD and AR. X-inactivation analysis for the methylation status of the AR gene showed random inactivation of the three X chromosomes. The results suggest that this 47,XXX male has resulted from abnormal X-Y interchange during paternal meiosis and X-X nondisjunction during maternal meiosis. Complex mosaicism may be due to the age-related increase in mitotic nondisjunction which is prone to occur in rapidly dividing lymphocytes and to the presence of two randomly inactivated X chromosomes which may behave asynchronously during mitosis, and clinical features of this male would primarily be explained by the genetic information on the SRY (+) der(X) chromosome and his advanced age.

Adolescent↗
PubMed2001

Malignant hepatic tumor detection with ferumoxides-enhanced MR imaging with a 1.5-T system: comparison of four imaging pulse sequences.

The purpose of our study was to compare observer performance in the detection of malignant hepatic tumors with ferumoxides-enhanced magnetic resonance (MR) images obtained with proton density-weighted spin-echo (SE), T2-weighted fast SE, T2*-weighted gradient-recalled-echo (GRE), and proton density-weighted echo-planar (EP) sequences. Ferumoxides-enhanced MR images obtained with the four sequences in 50 patients with 92 solid malignant and 64 nonsolid benign lesions were retrospectively analyzed. Image review was conducted on a segment-by-segment basis; a total of 397 liver segments was reviewed separately for solid and nonsolid lesions by three independent readers. Observer performance was evaluated with receiver operating characteristic analysis. Lesion-to-liver contrast-to-noise ratio was higher with SE and EP than with GRE and fast SE images for solid lesions (P < 0.05), and higher with fast SE and SE than with GRE images for nonsolid lesions (P < 0.01). Proton density-weighted SE and T2-weighted fast-SE images were superior to T2*-weighted GRE and proton density-weighted EP images for detection of malignant hepatic tumors. T2-weighted fast SE images were the best for detection of nonsolid lesions. T2-weighted fast SE images that were comparable to proton density-weighted SE images for solid tumor detection, that were the best for nonsolid lesion detection, and that had an acquisition time of one third to half of that of SE imaging may be able to replace SE images for ferumoxides-enhanced liver imaging.

Aged↗
PubMed2001

Expression of prostaglandin H synthase-2 in human brain tumors.

Numerous studies have demonstrated that prostaglandin H synthase-2 (PHS-2) is involved in gastrointestinal carcinogenesis, and that nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit PHS, can reduce the risk of colon cancer. In brain tumors, elevated prostaglandin production and its correlation to anaplastic grade of gliomas have been demonstrated. To determine whether the increased prostaglandin production is due to enhanced expression of PHS-2 and whether the up-regulation of PHS-2 has any correlation to histopathological findings in brain tumors, we evaluated the profile of PHS expression in several human glioma cell lines and surgical specimens from patients with various types of brain tumors. In glioma cell lines, five out of six cell lines showed constitutive expression of PHS-2, whereas PHS-1 was weakly expressed in all of them. All surgical specimens, except an ependymoma, which expressed both isozymes equally, expressed PHS-2 mRNA predominantly. Immunohistochemistry of various types of brain tumors, including six glioblastomas, nine astrocytomas, six meningiomas, five medulloblastomas, four craniopharyngiomas, three ependymomas, three neurinomas, two oligodendrogliomas, two malignant lymphomas, two dysembryoplastic neuroepitherial tumors and one metastatic brain tumor showed PHS-2 staining in most cases. In gliomas, astrocytomas (grade 2 and 3) were strongly stained, but the staining intensity of glioblastomas was relatively weak. Meningiomas and a metastatic brain tumor were also strongly stained. Our data thus suggest that most brain tumors express PHS-2, which may also play a role in tumorigenesis in the brain.

Adolescent↗
PubMed2001

Comparative genomics of medaka: the major histocompatibility complex (MHC).

The major histocompatibility complex (MHC) is one of the best characterized regions of the vertebrate genome. The human MHC has three subregions, classes I, II, and III. The MHC of chicken and Xenopus contain all three subregions. In contrast, in all teleost species so far analyzed, the class I and II genes are not linked to each other, suggesting that there was extensive genomic reorganization of the MHC region during an early stage of vertebrate evolution. To elucidate the details of this reorganization, we carried out genetic and physical analyses of the medaka MHC genes. We isolated the medaka counterparts of human MHC genes, class I A, class II B, LMP2, LMP7, TAP2, complement Bf and C4, and subjected them to linkage analysis. Except for the linkage of class IA, LMP2, LMP7, and TAP2 on linkage group (LG)11, all other genes were assigned to separate linkage groups. Thus, the class IA gene and the genes involved in class I antigen presentation seem to form the evolutionary stable core of the MHC. A physical analysis of medaka MHC class I region is in progress.

Journal Article↗
PubMed2001

Fukuyama muscular dystrophy associated with lack of C-terminal domain of dystrophin.

The first reported female patient with the Fukuyama type of congenital muscular dystrophy associated with a lack of C-terminal domain of dystrophin is presented. Clinically, the patient had characteristic features and magnetic resonance imaging findings of Fukuyama muscular dystrophy. Dystrophin analysis revealed a lack of the C-terminal domain but preserved N-terminal and rod domains of dystrophin in biopsied muscle. Moreover, she had reduced expression of merosin, syntrophin, and beta-dystroglycan in the skeletal muscle. Reverse transcriptase-polymerase chain reaction analysis of mRNA in the patient's muscle illustrated a complete lack of exons 71-74 of the dystrophin gene. These deletions, which remove the beta-dystroglycan and syntrophin binding site, may cause changes in the function of both beta-dystroglycan and syntrophin in human muscle.

Alcohol Oxidoreductases↗