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Biomedical subjects

S Matsunaga

Publications and source records attributed to S Matsunaga.

At least 37 records · Page 2Linked to original sources
PubMed2001

Possible prevention by abieslactone of development of diethylnitrosamine-initiated GST-P positive foci in the rat liver.

Triterpenoid compounds, isolated from plants of Abies genus (Pinceae), are known to exert anti-tumor promotion activities in mouse skin carcinogenesis. In the present study, we investigated whether AVB-1 and acid and acid methyl ester derivatives have inhibitory effects on rat hepatocarcinogenesis by using a liver medium-term bioassay for carcinogens (Ito's test), immunohistochemically assessing the numbers and areas per cm(2) of preneoplastic lesions, glutathione S-transferase placental form (GST-P)-positive foci. In experiment 1, 6-week-old male Fisher 344 rats were given a single intraperitoneal injection of diethylnitrosamine (200 mg/kg b.w.) and subjected to two-thirds partial hepatectomy at week 3. From weeks 2 to 8, the compounds were given three times a week at a dose of 1 mg/kg b.w. by i.g. gavage and found to significantly decrease the number of GST-P-positive foci in the liver. In experiment 2, AVB-1 was given three times a week at doses of 3, 1, or 0.3 mg/kg b.w. by i.g. gavage from weeks 2 to 8. All doses of AVB-1 significantly decreased the numbers of GST-P-positive foci. Thus, our results suggest that AVB-1 is a chemopreventive agent for rat hepatocarcinogenesis.

Alkylating Agents↗
PubMed2001

Gender-specific haplotype association of collagen alpha2 (XI) gene in ossification of the posterior longitudinal ligament of the spine.

Among Japanese, ossification of the posterior longitudinal ligament of the spine (OPLL) is a leading cause of myelopathy, showing ectopic bone formation in the paravertebral ligament. We have provided genetic evidence that the collagen alpha2 (XI) (COL11A2) locus of chromosome 6 constitutes susceptibility for OPLL. Five distinct single nucleotide polymorphisms (SNPs), identified in COL11A2, were combined to construct possible haplotypes by the use of a maximum likelihood program. Estimated haplotype frequency was compared in OPLL patients and non-OPLL controls. We report a gender-specific association of the COL11AA2 haplotvpe with OPLL. The frequency of the most commonly observed haplotype was significantly higher in male patients (P = 0.0003) compared with controls, but not in female patients (P = 0.21). OPLL is predominantly observed in males. with a prevalence ratio of 2:1, and our gender-specific associations indicate that genetic factors involving COL11A2 play a specific role in the etiology of OPLL exclusively in males.

Aged↗
PubMed2001

Photocatalytic degradation of trichloroethylene in water using TiO2 pellets.

A recirculating system of aqueous trichloroethylene (TCE) solutions through the packed bed reactor with TiO2 pellets has been developed in order to mineralize TCE without difficulties for filtration and recovery of catalyst. The TiO2 pellets prepared by sol gel method have photocatalytic activity similar to commercially available PC-101 and PC-102 in the powder form and to ST-B11 pellets. In batch experiments with TiO2 powders, Degussa P-25 is the most active photocatalyst, which indicates that specific surface area is not an important factor controlling the photocatalytic activity in aqueous solutions. The degradation rates of TCE in the recirculating system with TiO2 pellets decreased in the presence of H2O2, while were remarkably accelerated by adding S2O8(2-). The presence of S2O8(2-) ions more than 0.01 mol dm(-3) completely suppressed hole-electron recombination and mineralized 50 ppm TCE with the 2 h irradiation. In a reactor without TiO2 photocatalysts, TCE was photodegraded by SO4- radicals which produced by photodissociation of S2O8(2-). The degradation rates increased with increase of the initial S2O8(2-) concentration. However, TCE was not mineralized but converted to intermediates which were slowly degraded to Cl- by continuing the irradiation.

Catalysis↗
PubMed2001

Anti-tumor promoting diterpenes from the stem bark of Thuja standishii (Cupressaceae).

Three new labdane-type diterpenoids, labda-8(17),13-dien-15,12R-olid-19-oic acid (1), 12S-hydroxylabda-8(17),13(16),14-trien-19-oic acid (2) and 13-ethoxylabda-8(17),11,14-trien-19-oic acid (3), along with known diterpenoids, trans-communic acid (4), totarol (5), 12-methoxyabieta-8,11,13-trien-11-ol (6), and 7 alpha,8 alpha-epoxy-6 alpha-hydroxyabieta-9(11),13-dien-12-one (7) were isolated from the stem bark of Thuja standishii. The structures of 1--3 were established by spectroscopic methods and chemical conversion. These compounds together with standishinal (8), 12-hydroxy-6,7-seco-abieta-8,11,13-trien-6,7-dial (9) and 6 alpha-hydroxysugiol (10) were tested for their inhibitory effects on Epstein--Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), as a test for potential cancer chemopreventive agents. Compound 10 showed strong inhibitory effect on EBV-EA induction (100% inhibition at 1000 mol ratio/TPA), and compounds 2 and 6 showed moderate inhibitory effects on EBV-EA induction. In addition, 15-oxolabda-8(17),11Z,13E-trien-19-oic acid (11) was found to exhibit the anti-tumor promoting activity in two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene and TPA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Structure and stereochemistry of epoxyserratanes from the cuticle of Piceajezoensis var. jezoensis.

Three new epoxytriterpenes, 14 beta,15 beta-epoxy-21 beta-hydroxyserratan-3-one (1), 13 alpha,14 alpha-epoxy-21 alpha-methoxyserratan-3-one (2), and 13 alpha,14 alpha-epoxy-3 beta-methoxyserratan-21 beta-ol (3), were isolated together with two known triterpenoids, 21 alpha-methoxyserrat-13-en-3-one (4) and 21 beta-hydroxyserrat-14-en-3-one (5), from the cuticle of Picea jezoensis var. jezoensis. The structures of these new compounds were established on the basis of spectral data (NMR, MS) and single-crystal X-ray analyses (1 and 2) and partial synthesis (2 and 3).

Chromatography, Thin Layer↗
PubMed2001

Four new bioactive pyrrole-derived alkaloids from the marine sponge Axinella brevistyla.

Four new alkaloids (1-4) were isolated from the marine sponge Axinella brevistyla, and their structures were determined on the basis of spectroscopic analysis. The alkaloids 1-4 were antifungal against the yeast Saccharomyces cerevisiae at <1.0, <1.0, 30, and 100 microg/disk, respectively. Compounds 1-3 also exhibited cytotoxicity against L1210 cells with IC(50) values of 1.1, 0.66, and 2.5 microg/mL, respectively.

Alkaloids↗
PubMed2001

Inactivation of sarcoplasmic reticulum Ca(2+)-atpase in low-frequency stimulated rat muscle.

Continuous low-frequency stimulation (CLFS) by implanted electrodes for 12-24 h led to a significant (approximately 30%) decrease in the activity of sarcoplasmic reticulum Ca(2+)-ATPase in fast-twitch extensor digitorum longus (EDL) and tibialis anterior (TA) muscles of intact rats. The decline in catalytic activity after 24 h of CLFS was accompanied by an approximately twofold increase in dinitrophenylhydrazine-reactive carbonyl groups of the enzyme. It also correlated with an immunochemically determined 30% decrease in Ca2(+)-ATPase protein. Recovery studies after 12 h of CLFS revealed a relatively slow (48-72 h) re-establishment of normal catalytic activity. These findings suggest that the 30% decline of Ca(2+)-ATPase activity in low-frequency stimulated rat muscle led to an irreversible modification by protein oxidation. The decrease in Ca(2+)-ATPase protein most likely resulted from the degradation of inactive Ca(2+)-ATPase molecules. The relatively slow recovery of Ca(2+)-ATPase activity suggests that de novo synthesis of the enzyme may be necessary to re-attain normal activity.

Animals↗
PubMed2001

Epidural analgesia with a combination of bupivacaine and buprenorphine in rats.

We determined the analgesic effects of epidural administration of either bupivacaine at 62.5, 125, 250, and 500 micrograms/kg; buprenorphine at 5 and 10 micrograms/kg; and the combination of bupivacaine at 125 micrograms/kg and buprenorphine at 5 or 10 micrograms/kg, using the tail flick (TF) and colorectal distension (CD) tests in rats and compared the results with those obtained using morphine at 100 micrograms/kg. In both the TF and CD tests, all doses of bupivacaine alone produced potent anti-nociceptive effects, although the effect rapidly diminished after 20-30 min of administration. The administration of buprenorphine at 10 and 5 micrograms/kg produced mild to moderate anti-nociceptive effects in both the TF and CD tests, and the effects were relatively constant throughout the 2-h experimental period. Combinations of 5 or 10 micrograms/kg of buprenorphine with 125 mg/kg of bupivacaine produced a significantly higher percentage of maximum possible analgesic effect (%MPE) than that of the calculated additive effect of each drug alone in the TF and CD tests. The analgesic effect of this combination was similar to that of morphine. Minimal ataxia was observed in rats administered this combination.

Analgesia, Epidural↗
PubMed2001

Abietane diterpenoids from the cones of Larix kaempferi and their inhibitory effects on Epstein-Barr virus activation.

Four known (1-3, 8) and four new abietane diterpenes, 15-hydroxy-8alpha,14alpha,12alpha,13alpha-diepoxyabietan-18-oic acid (4), 7alpha,8alpha,13beta,14beta-diepoxyabietan-18-oic acid (5), 18-nor-abieta-8,11,13-triene-4alpha,7alpha,15-triol (6), and abieta-8,11,13-triene-7alpha,15,18-triol (7) were isolated from the CHCl3 extract of the cones of Larix koempferi. A known compound, 13,14-seco-13,14-dioxoabiet-13-en-18-oic acid (8) was isolated from natural sources for the first time. Their structures were determined by chemical and spectroscopic methods including 1D and 2D NMR techniques. The absolute stereostructure of 5 was determined by X-ray crystallographic analysis. The inhibitory effects of these compounds on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), were examined as a primary screening for antitumor promotors.

Abietanes↗
PubMed2001

Localization of male-specifically expressed MROS genes of Silene latifolia by PCR on flow-sorted sex chromosomes and autosomes.

The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species.

Amino Acid Sequence↗
PubMed2001

G2/M-phase-specific transcription during the plant cell cycle is mediated by c-Myb-like transcription factors.

Plant B-type cyclin genes are expressed specifically in late G2- and M-phases during the cell cycle. Their promoters contain a common cis-acting element, called the MSA (M-specific activator) element, that is necessary and sufficient for periodic promoter activation. This motif also is present in the tobacco kinesin-like protein gene NACK1, which is expressed with timing similar to that of B-type cyclin genes. In this study, we show that G2/M-phase-specific activation of the NACK1 promoter also is regulated by the MSA element, suggesting that a defined set of G2/M-phase-specific genes are coregulated by an MSA-mediated mechanism. In a search for MSA binding factors by yeast one-hybrid screening, we identified three different Myb-like proteins that interact specifically with the MSA sequence. Unlike the majority of plant Myb-like proteins, these Myb proteins, NtmybA1, NtmybA2, and NtmybB, have three imperfect repeats in the DNA binding domain, as in animal c-Myb proteins. During the cell cycle, the level of NtmybB mRNA did not change significantly, whereas the levels of NtmybA1 and A2 mRNAs fluctuated and peaked at M-phase, when B-type cyclin genes were maximally induced. In transient expression assays, NtmybA1 and A2 activated the MSA-containing promoters, whereas NtmybB repressed them. Furthermore, expression of NtmybB repressed the transcriptional activation mediated by NtmybA2. Our data show that a group of plant Myb proteins that are structurally similar to animal c-Myb proteins have unexpected roles in G2/M-phase by modulating the expression of B-type cyclin genes and may regulate a suite of coexpressed genes.

Base Sequence↗
PubMed2001

Expression of matrix metalloproteinases during ascorbate-induced differentiation of osteoblastic MC3T3-E1 cells.

The mouse calvarial osteoblast MC3T3-E1 cells released 92 kDa and 68 kDa of gelatinase activities into the conditioned media (CMs) from undifferentiated cells. When differentiation was induced by cultivating cells with ascorbate-2-phosphate (AscP), 68-kDa activity increased significantly in parallel with production of 60-kDa activity. These enzymes required Ca2+ and Zn2+ ions for their proteolytic activities. The 68-kDa activity was immunologically identified as latent matrix metalloproteinase 2 (MMP-2). The 92-kDa activity was deduced to be latent MMP-9 based on its molecular mass. The 60-kDa activity band was found to possess both gelatin and beta-casein hydrolyzing activities, indicating that this activity band might comprise the active form of MMP-2 and latent MMP-13. MC3T3-E1 cells were found to express MMP-2, MMP-13, and membrane type (MT)1-MMP genes by Northern blotting. MMP-2 was expressed constitutively. MMP-13 was up-regulated during the growth with AscP. MT1-MMP expression also was modulated by AscP; at the early stage of differentiation, its messenger RNA (mRNA) level increased and then decreased gradually to the control level. These changes in the profiles of MMPs observed here could be attributed to the maturation of collagenous extracellular matrix (ECM) induced by AscP.

3T3 Cells↗
PubMed2001

Pronociceptive effects of nociceptin/orphanin FQ (13-17) at peripheral and spinal level in mice.

The heptadecapeptide nociceptin/orphanin FQ (N/OFQ) is reported to be metabolized by aminopeptidase N and endopeptidase 24.15. In the present study, N/OFQ C-terminal fragments elicited nociceptive responses in the peripheral nociceptors and in the spinal cord, whereas N-terminal fragments had no significant nociception. The nociceptive effect of N/OFQ (13-17) was most potent and remained unchanged in N/OFQ peptide receptor (NOPR) gene knockout mice, indicating that N/OFQ (13-17)-induced nociception is mediated through a novel mechanism independent of the activation of NOPR. This finding was further confirmed by in vitro guanosine 5'-O-(3-[35S]thio)triphosphate binding experiments, in which N/OFQ (13-17) showed no significant binding activity in baculovirus/sf21 cells expressing NOPR together with G protein alpha(i)1-, beta1-, and gamma2-subunits, whereas N/OFQ showed stimulation in a concentration-dependent manner. On the other hand, although a typical bell-shaped dose-response relationship was observed with a wide range of N/OFQ doses in both peripheral and central nociception tests, N/OFQ (13-17) did not show bell-shaped dose-response relationship in the central nociception test. This finding indicates that N/OFQ (13-17), in contrast to N/OFQ, lacks the postsynaptic antinociceptive actions modulating substance P signaling in the spinal cord. Together, our results suggest that C-terminal fragments of N/OFQ have potent nociceptive actions, and N/OFQ (13-17) could have the potential to mediate its actions through a novel mechanism independent of the activation of NOPR in the nociceptors and in spinal synapses.

Animals↗
PubMed2001

[A case of malignant pericardial effusion due to breast cancer successfully controlled by intrapericardial chemotherapy using pirarubicin].

We report a case of malignant pericardial effusion due to breast cancer that was successfully controlled by intrapericardial chemotherapy using pirarubicin. A 53-year-old woman underwent breast conserving therapy for left breast cancer in 1996. She was given CAF therapy and UFT as adjuvant therapy. Three years and 10 months after operation, she had malignant pericardial and pleural effusion. Pericardiocentesis and pleurocentesis were performed immediately. Pericardial effusion relapsed after some time and she was treated with intrapericardial chemotherapy using pirarubicin. After this treatment she has not suffered from pericardial effusion for 1 year and 4 months to date. This case suggests that intrapericardial chemotherapy is effective for malignant pericardial effusion.

Adenocarcinoma↗
PubMed2000

Cancer chemopreventive agents, labdane diterpenoids from the stem bark of Thuja standishii (Gord.) Carr.

Seven labdane-type diterpenoids from the stem bark of Thuja standishii (Gord.) Carr. (Cupressaceae) and their analogues showed strong inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Among these compounds, 15,16-bisnor-13-oxolabda-8(17), 11E-dien-19-oic acid was revealed to have the strongest inhibitory effect on the EBV-EA activation, being stronger than that of beta-carotene which has been intensively studied in cancer prevention using animal models. 15,16-bisnor-13-Oxolabda-8(17), 11E-dien-19-oic acid was also found to exhibit the excellent anti-tumor promoting activity in two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene and TPA.

9,10-Dimethyl-1,2-benzanthracene↗