Biomedical subjects

T Nikaido

Publications and source records attributed to T Nikaido.

At least 55 records · Page 3Linked to original sources

PubMed1999

Sensitization of methamphetamine-induced disorganization of daily locomotor activity rhythm in male rats.

Methamphetamine (MAP) was administered to rats through drinking water repeatedly (three sessions, one session:administration for 60 days followed by withdrawal of 30 days) in order to examine whether or not MAP-induced disorganization of daily activity rhythm is sensitized. Each session (60 days) was divided into six blocks of 10 days. In the 1st session, daily locomotor activity rhythm of rats became disorganized around at 40 days (4th block) after the start of MAP drinking. However, MAP-induced disorganization of daily activity rhythm appeared at 20 days (2nd block) in the 2nd session and at 10 days (1st block) in the 3rd session following re-start of MAP drinking. On the other hand, the amount of MAP intake was decreased on the 2nd and 3rd sessions as compared with the 1st session. These results indicate that the mechanism of MAP-induced disorganization of daily activity rhythm may involve sensitization.

Activity Cycles↗

PubMed1999

Expression of cyclins and cyclin-dependent kinases in smooth muscle tumors of the uterus.

To investigate the cell cycle regulatory mechanisms involved in the growth of smooth muscle tumors, we studied the expression of Ki-67, cyclins E and A, and their catalytic partners, the cyclin-dependent kinases cdk2 and cdc2 by using tissue specimens from benign and malignant smooth muscle tumors. These included 20 cases of usual leiomyoma (UL), 18 of cellular leiomyoma (CL), 8 of bizarre leiomyoma (BL), 8 of uncertain malignant potential tumors (UMP) and 20 of leiomyosarcoma (LMS). The proliferation rate detected by Ki-67 was low in normal myometrium and leiomyomas (UL, CL and BL), but it was markedly increased in LMS. The expression of the cyclins (E and A) and cdks (cdk2 and cdc2) was also low in normal myometrium and leiomyomas. However, the expression of these factors was markedly increased in LMS. In addition, a survival analysis using Log-rank test, revealed that LMSs with positive staining for cyclin A and with diffusely staining for cyclin E were associated with significantly shorter survival. Our results suggest that expression of cyclins and cdks may be involved in the growth control of uterine smooth muscle tumors.

Adult↗

PubMed1999

Identification of a novel gene, OASIS, which encodes for a putative CREB/ATF family transcription factor in the long-term cultured astrocytes and gliotic tissue.

Gliosis is a characteristic response of astrocytes to inflammation and trauma of the central nervous system (CNS). To study the mechanisms underlying gliosis, we performed differential display screening for genes specifically induced in long-term cultured astrocytes used as an in vitro gliosis model. We identified and characterized a gene (named OASIS, for old astrocyte specifically-induced substance) expressed in long-term cultured mouse astrocytes, or 'old astrocytes (OA)'. The OASIS gene encoded a putative transcription factor belonging to the cyclic AMP responsive element binding protein/activating transcription factor (CREB/ATF) gene family, with homology to box B-binding factor-2 (BBF-2), a Drosophila transcription factor. Its expression was developmentally regulated; OASIS mRNA was primarily expressed in the salivary gland and cartilage in the mouse embryo and it was transiently upregulated in the brain during postnatal two weeks. The expression became weaker in the adult brain. We also demonstrated that an expression of the OASIS mRNA was induced in response to the cryo-injury of the mouse cerebral cortex. The distribution pattern of the OASIS-positive cells in the injured cortex was very similar to that of the glial fibrillary acidic protein (GFAP)-positive cells. These results suggest that OASIS protein may play a role in gliotic events.

Activating Transcription Factors↗

PubMed1999

Possible role of calponin h1 as a tumor suppressor in human uterine leiomyosarcoma.

BACKGROUND: Calponin h1, a basic actin-binding protein capable of inhibiting smooth muscle contraction, is a constitutive element of smooth muscle cells. However, in leiomyosarcoma (a type of smooth muscle neoplasm of the uterus), reduced expression of calponin h1 is observed, as we have reported previously. In this study, we sought to assess the effects (in vitro and in vivo) of increasing calponin h1 expression in leiomyosarcoma cells. METHODS: A plasmid containing a human calponin h1 complementary DNA and a bacterial neomycin-resistance gene was transfected into the human leiomyosarcoma cell lines SKN and SK-LMS-1 by electroporation. Southern blotting, reverse transcription-polymerase chain reaction analysis, western blotting, and immunohistochemistry were used to confirm DNA transfer and expression of the calponin h1 protein in neomycin-resistant clones. We characterized the morphology of calponin h1-transfected cells, and we evaluated their proliferative activity and tumorigenicity by use of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, an anchorage-independent growth assay, and a nude mouse tumorigenicity assay. RESULTS: The morphology of calponin h1-transfected cells in culture resembled that of cultured normal myometrial smooth muscle cells. With SK-LMS-1 cells, proliferation of calponin h1-transfection cells was reduced to 69% of control; with SKN cells, calponin h1 transfection reduced proliferation to 70% of control. In assays of anchorage-independent growth and in vivo tumorigenicity, both growth and tumorigenicity were statistically significantly reduced in calponin h1-transfected leiomyosarcoma cells. CONCLUSIONS: Calponin h1 may function as a tumor suppressor in leiomyosarcoma. Clinically, transfer of a calponin h1 complementary DNA into poorly differentiated leiomyosarcoma cells may be of potential therapeutic value through induction of a normal, differentiated cellular phenotype.

Animals↗

PubMed1999

Eos: a novel member of the Ikaros gene family expressed predominantly in the developing nervous system.

We identified a novel member of the Ikaros gene family, which has critical roles in the development of lymphoid lineages. This gene, which we named Eos, was expressed predominantly in the developing central and peripheral nervous system. Eos protein could interact with itself and Ikaros protein through its C-terminal portion in the yeast two hybrid assay. These findings suggested that Eos may have important roles in neural development similarly to the Ikaros family in the development of hemolymphoid tissue.

Amino Acid Sequence↗

PubMed1999

Clear cell carcinoma has an expression pattern of cell cycle regulatory molecules that is unique among ovarian adenocarcinomas.

BACKGROUND: The purpose of this study was to identify biologic differences between ovarian clear cell carcinoma and other ovarian adenocarcinomas by comparing the expression of cell cycle regulatory molecules and by analyzing the survival of the patients. METHODS: In 51 cases of epithelial ovarian carcinoma, the expression of the cell proliferation marker Ki-67 and that of the cell cycle regulatory molecules p53, p16, p21, p27, cyclin E, and cyclin A was studied using immunohistochemical techniques. The correlations among clinical stage, histologic subtype, labeling index for Ki-67, and expression of these cell cycle regulators were examined statistically. Multivariate survival analysis was performed using these factors in the Cox proportional hazards model. RESULTS: Clear cell carcinoma revealed such trends as low expression of both p53 and cyclin A and significantly increased expression of both p21 and cyclin E (compared with the other histologic subtypes). In all ovarian carcinomas, a very strong positive correlation (correlation coefficient 0.79; P < 0.0001) between p53 positive staining and cyclin A positive staining and a weak positive correlation (correlation coefficient 0.47; P < 0.01) between p21 positive staining and cyclin E positive staining were recognized at the level of expression of cell cycle regulatory molecules. Clinical stage was the only independent predictive factor for the survival of the patients. CONCLUSIONS: Among ovarian adenocarcinomas, clear cell carcinoma exhibits a unique pattern of expression of cell cycle regulatory molecules, though in this study the survival of the patients did not correlate with histologic subtype, only with clinical stage.

Adenocarcinoma↗

PubMed1999

Frequent occurrence of loss of heterozygosity among tumor suppressor genes in uterine leiomyosarcoma.

OBJECTIVE: Leiomyosarcoma of the uterus is a rare smooth muscle tumor; it is extremely malignant and the rates of local recurrence and metastasis are high. Since tumor suppressor genes are commonly altered in malignant tumors, it is possible that mutations in such genes are involved in the development of uterine leiomyosarcoma. METHODS: Fifty-five patients (37-70 years of age) diagnosed as having smooth muscle tumors of the uterus were selected. DNA was extracted from four or five 8-microm-thick consecutive tissue sections of each smooth muscle tumor from the paraffin-embedded blocks. Loss of heterozygosity (LOH) was investigated at nine loci within or close to tumor suppressor genes (TP53, RB1, DCC, NM23, WT1, D14S267, P16, DPC4, PTCH). RESULTS: Nineteen of twenty leiomyosarcomas revealed at least one instance of LOH among eight of the nine markers tested (one locus showed no LOH at all). In fact, 11 of the 20 cases exhibited two or more instances of LOH and, of the remaining 9 cases, 4 showed a point mutation of p53 in addition to an alteration in one of the 9 markers, while one exhibited a p53 mutation only. CONCLUSION: An accumulation of genetic alterations among tumor suppressor genes may play a key role in the tumorigenesis and progression of uterine leiomyosarcoma.

Adult↗

PubMed1999

Acyclic and incompletely cyclized triterpene alcohols in the seed oils of theaceae and gramineae.

The triterpene alcohol constituents of the non-saponifiable lipids of two Theaceae seed oils, sasanqua and camellia oils, and two Gramineae seed oils, wheat germ and rice bran oils, were investigated. This led to the isolation and characterization of one acyclic and eight incompletely cyclized triterpene alcohols. They are camelliol A, camelliol B, camelliol C, achilleol A, helianol, isohelianol, sasanquol, graminol A [(13R, 14R)-3,4-seco-25(10->9)abeo-8alpha,9beta,10al phapodioda-4,17,21 -trien-3-ol], and (2Z,6Z,10Z,14E,18E)-farnesyl-farnesol. Two other compounds isolated were characterized as (2Z,6Z,10E,14E)-geranylfarnesol, a sesterterpene alcohol, and phytol, a diterpene alcohol. Graminol A and (2Z,6Z,10E,14E)-geranylfarnesol are considered to be new natural products.

Alcohols↗

PubMed1999

Tranilast inhibits the proliferation of human coronary smooth muscle cell through the activation of p21waf1.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) occurs due to vascular smooth muscle cell proliferation and migration. Recently, tranilast, an anti-allergic drug, has been used for the prevention of restenosis after PTCA. To determine the molecular mechanism involved, the effect of tranilast on the proliferation of human coronary smooth muscle cells (SMCs) was investigated. Tranilast arrested the proliferation of human coronary SMCs at the G0/G1 phase of the cell cycle. In association with this inhibitory effect, tranilast increased p21waf1 and p53 tumor suppressor factor, and decreased cyclin-dependent kinase 2 (CDK2) activity. These results suggest that tranilast inhibits the proliferation of human coronary SMCs during restenosis after PTCA via an induction of p21waf1 and p53. Tranilast may thus allow us to prevent restenosis after PTCA by interfering with this mechanism.

Anti-Allergic Agents↗

PubMed1999

Triterpenoidal saponins from Gleditsia sinensis.

Six bisdesmosidic triterpenoidal saponins, gleditsiosides H-K and gleditsia saponins C' and E', were isolated from the anomalous fruits of Gleditsia sinensis. Their structures were established by a combination of extensive NMR (DEPT, DQF-COSY, HETCOR, HOHAHA, HMBC and ROESY) studies and chemical degradation.

Carbohydrate Conformation↗

PubMed1999

Localization of huntingtin-interacting protein-2 (Hip-2) mRNA in the developing mouse brain.

Huntingtin-interacting protein-2 (Hip-2) was identified as a human protein specifically associated with huntingtin in vitro, a gene product affected in patients with Huntington disease (HD). It is a ubiquitin-conjugating enzyme identical to the previously characterized bovine E2-25k. We identified the mouse Hip-2 homologue (mHip-2) and examined its distribution patterns in the developing mouse brain in order to gain an insight into the functional significance of the Hip-2 protein in the normal brain as well as in the pathogenesis of HD. As reported with huntingtin, the mHip-2 mRNA expression developed in parallel with neuronal maturation and became distributed widely in the postnatal mouse brain. This spatiotemporal pattern of mHip-2 mRNA expression resembled that of huntingtin. We further demonstrated that mHip-2 mRNA was colocalized with huntingtin-like immunoreactivity in a single neuron. These findings suggested that the Hip-2 interacted with huntingtin in vivo and played an important role in HD pathogenesis.

Amino Acid Sequence↗

PubMed1999

Two diterpenoids from the roots of gaultheria yunnanensis

Two new diterpenoids, gaultheric acid (1) and gaultheronoterpene (2), were isolated from the roots ofGaultheria yunnanensis. Their structures were elucidated as 12-hydroxy-13-acetyl-8,11, 13-podocarpatrien-18-oic acid (1) and 3beta, 12-dihydroxy-13-acetyl-4(18),8,11,13-podocarpatetraene (2) on the basis of spectral analysis.

Journal Article↗

PubMed1999

New triterpenoid saponins from Maesa japonica.

New triterpenoid saponins, maejaposides A, B, C, D, and E, were isolated from the roots of Maesa japonica and were, respectively, defined to be 3-O-[beta-D-xylopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->2)-bet a-D-galactopyranosyl-(1-->3)] [beta-D-galactopyranosyl-(1-->2)]beta-D-glucuronopyranosides of 22alpha-[(Z)-2-hexenoyloxy]-13beta,28-oxido-olean++ +-16alpha, 28alpha-diol (1); 22alpha-[2'-methylbutanoyl]-13beta, 28-oxido-olean-16alpha,28alpha-diol (2a) and 22alpha-angeloyloxy-13beta,28-oxido-olean-16a lpha,28alpha-diol (2b); 21beta,22alpha-diangeloyloxy-13beta,28-oxido- olean-16alpha, 28alpha-diol (3); 21beta-angeloyloxy, 22alpha-(2'-methylbutanoyl)-13beta,28-oxido-olean++ +-16alpha, 28alpha-diol (4), and 21beta-angeloyloxy, 22alpha-[(Z)-2'-hexenoyl]-13beta,28-oxido-olean- 16alpha,28alpha-diol (5). Their structures were established on the basis of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC, and NOESY) and ESIMS/MS studies, along with chemical degradation.

Carbohydrate Sequence↗

PubMed1999

Camelliols A-C, three novel incompletely cyclized triterpene alcohols from sasanqua oil (Camellia sasanqua)

Three novel triterpene alcohols, camelliols A (1), B (3), and C (5), possessing a mono-, bi-, and tricyclic ring system, respectively, have been isolated, along with achilleol A, a known monocyclic triterpene alcohol, from the nonsaponifiable lipids of sasanqua oil (Camellia sasanqua). The structures of these new alcohols were determined on the basis of spectroscopic methods.

Journal Article↗

PubMed1999

Saponarioside C, the first alpha-D-galactose containing triterpenoid saponin, and five related compounds from Saponaria officinalis.

Six novel triterpenoid saponins, named saponariosides C-H, were isolated from the whole plants of Saponaria officinalis. Their structures were established as saponarioside C (1), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-alpha-D-galactopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-- >6)-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside D (2), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside E (3), 3-O-beta-D-glucopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside F (4), 3-O-beta-D-xylopyranosyl-16alpha-hydroxygypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6) -[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside; saponarioside G (5), 3-O-beta-D-xylopyranosyl-16alpha-hydroxygypsogenic acid-28-O-beta-D-glucopyranosyl-(1-->6)-[beta-D-glucopyranosyl-(1-->3 )]-beta-D-glucopyranoside; and saponarioside H (6), 3-O-beta-D-xylopyranosyl-gypsogenic acid-28-O-beta-D-glucopyranoside, by a combination of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC, and NOESY) studies and chemical degradation.

Carbohydrate Sequence↗

PubMed1999

Four new triterpenoidal saponins acylated with one monoterpenic acid from Gleditsia sinensis.

Four new oleanane-type triterpenoidal glycosides, named gleditsiosides A-D (1-4), were isolated from the anomalous fruits of Gleditsia sinensis. Using modern NMR techniques, including DQF-COSY, HETCOR, HOHAHA, HMBC, and ROESY experiments and MS analysis as well as chemical methods, their structures were determined as 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha- L-rhamnopyranosyl-(1-->2)-[(6S,2E)-6-hydroxy-2,6-dimethyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (1); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha- L-rhamnopyranosyl-(1-->2)-[(2E)-2-hydroxylmethyl-6-hydroxy-6-methy l-2 ,7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (2); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta- D-galactopyranosyl-(1-->2)]-alpha-L-rhamnopyranosyl-(1-->2)-[(2E)-2-h ydroxylmethyl-6-hydroxy-6-methyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (3); and 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- bet a-D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta- D-galactopyranosyl-(1-->2)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6S, 2E)-6-hydroxy-2,6-dimethyl-2, 7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (4).

Carbohydrate Sequence↗

PubMed1999

Gleditsiosides N-Q, new triterpenoid saponins from Gleditsia sinensis.

The structures of gleditsiosides N, O, P, and Q (1-4), isolated from anomalous fruits of Gleditsia sinensis, were characterized as novel complex bisdesmosidic triterpenoid glycosides acylated with monoterpenoid units, by means of extensive 1D and 2D NMR studies. The four compounds shared a common structural feature with a trisaccharide [(beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-be ta- D-glucopyranoside)] affixed to C-3 and a tetrasaccharide [(beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-r hamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester)] attached to C-28. Gleditsioside P (3) is the first saponin of this type found to date bearing three monoterpenoid units.

Carbohydrate Sequence↗

PubMed1999

New triterpenoid saponins and sapogenins from Saponaria officinalis.

Five new triterpenoid saponins, named saponariosides I-M, were isolated from the whole plants of Saponario officinalis. Their structures were established as saponarioside I (1) 3-O-beta-D-xylopyranosyl-16 alpha-hydroxygypsogenic acid 28-O-alpha-D-galactopyranosyl-(1-->6)-beta-D- glucopyranosyl-(1-->3)[-beta-D-glucopyranoside[, saponarioside J (3) 3-O-beta-D-xylopyranosylolean-11,13(18)-diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[- beta-D-glucopyranoside[, saponarioside K (4) 3,4-seco-16 alpha-hydroxygypsogenic acid 28-O-beta-D-glucopyranosyl- (1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta-D-glucopyranoside[, saponarioside L (5) 3-O-beta-D-xylopyranosylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)[-beta- D- glucopyranoside[, and saponarioside M (6) 3-O-beta-D-glucopyrano-sylgypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1--6)-beta-D- glucopyranoside[ by NMR studies and chemical degradations. The aglycons of saponariosides J (3) and K (4) are new sapogenins.

Fabaceae↗