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Biomedical subjects

T Tanahashi

Publications and source records attributed to T Tanahashi.

At least 19 recordsLinked to original sources
PubMed2001

Tetrahydroisoquinoline-monoterpene and iridoid glycosides from Alangium lamarckii.

From the water soluble fraction of the dried fruits of Alangium lamrckii, four tetrahydroisoquinoline-monoterpene glycosides, 6-O-methyl-N-deacetylisoipecosidic acid, 7-O-methyl-N-deacetylisoipecosidic acid, 6,7-di-O-methyl-N-deacetylisoipecosidic acid and 6"-O-alpha-D-glucopyranosyl-6-O-methyl-N-deacetylisoipecosidic acid, and an iridoid glycoside, 6'-O-alpha-D-glucopyranosylloganic acid, were isolated, together with six known compounds. The structures of the previously unknown compounds were determined by spectroscopic and chemical means. The significance of these glucosides in the biogenesis of Alangium alkaloids is discussed; 6-O-methyl-N-deacetylisoipecosidic acid was also chemically converted into 10-O-demethylprotoemetine and dihydroisoalangine.

Asteraceae↗
PubMed2001

Dibenzofurans from the cultured lichen mycobionts of Lecanora cinereocarnea.

From the cultures of the spore-derived mycobionts of the lichen Lecanora cinereocarnea, five dibenzofurans, 3,7-dihydroxy-1,9-dimethyldibenzofuran, 2-chloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 2,8-dichloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 3-hydroxy-7-methoxy-1,9-dimethyldibenzofuran, and 2-chloro-7-hydroxy-3-methoxy-1,9-dimethyldibenzofuran, were isolated. Their structures were determined by spectroscopic methods.

Benzofurans↗
PubMed2001

Glycosides of benzyl and salicyl alcohols from Alangium chinense.

From the water-soluble fraction of the dried leaves of Alangium chinense, three new glycosides, benzyl alcohol beta-D-glucopyranosyl-(1 --> 2)-[beta-D-xylopyranosyl-(1 --> 6)]-beta-D-glucopyranoside, 2'-O-beta-D-glucopyranosylsalicin, and 2'-O-beta-D-glucopyranosyl-6'-O-beta-D-xylopyranosylsalicin were isolated along with seven known glycosides. The structures of the new compounds were determined by spectroscopic and chemical means.

Benzyl Alcohols↗
PubMed2001

Hypervascular liver metastasis from hypovascular ductal cell carcinoma of the pancreas.

In a case of hypervascular metastatic liver tumor, the vascularity of primary focus, pancreatic carcinoma was hypovascular. Based on the imaging findings, we thought before the operation that the two lesions were double cancers. Histological examination showed that the stromal volume of metastatic tumorous tissue was richer than that of the primary focus. It was suggested that the difference in the stromal volume was related to the difference of the vascularity. Some foctors originating in stromal cells might be involved in angiogenesis.

Carcinoma, Pancreatic Ductal↗
PubMed2000

Endoscopic mucosal resection using a partial transparent hood for lesions located tangentially to the endoscope.

BACKGROUND: Numerous methods have been developed to resect early-stage gastric and esophageal cancers, but it is difficult to resect lesions viewed tangentially with the endoscope. METHODS: We have designed and developed an original method of endoscopic mucosal resection using a partial transparent hood to treat difficult cases in which the lesions are located tangentially to the endoscope. The hood was attached on the right side of the endoscope and, after insertion into the stomach or the esophagus, was lightly pressed on the orad side of the lesion. Then the lesion was resected using grasping forceps and electrosurgical current snare. RESULTS: The average diameter of specimens was 26 +/- 8 mm in gastric lesions and 20 +/- 3 mm in esophageal lesions, both 6 mm larger than those obtained by previous methods. CONCLUSION: This device and technique were extremely useful for mucosal resection of lesions located tangentially to the endoscope.

Electrosurgery↗
PubMed2000

Two Alangium alkaloids from Alangium lamarckii.

Two new Alangium alkaloids, 1',2'-dehydrotubulosine (1) and alangine (2), were isolated from the dried fruits of Alangium lamarckii along with tubulosine (3), isotubulosine (4), deoxytubulosine, cephaeline, isocephaeline, psychotrine, neocephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1" -beta-D-fructopyranosyl)cephaeline, protoemetine, protoemetinol, salsoline, and alangiside. The structures of the new alkaloids (1 and 2) were determined by spectroscopic and chemical means.

Alkaloids↗
PubMed2000

Five phenolic glycosides from Alangium chinense.

From the dried leaves of Alangium chinense, five novel phenolic glycosides, 6'-O-galloylsalicin (1); 4',6'-di-O-galloylsalicin (2); 4',6'-O-(S)-hexahydroxydiphenoylsalicin (3); 4', 6'-O-(R)-hexahydroxydiphenoylsalicin (4); and pyrocatechol 1-O-beta-D-xylopyranosyl(1-->6)-beta-D-glucopyranoside (5) were isolated. The structures of these new compounds were determined by spectroscopic methods.

Carbohydrate Conformation↗
PubMed2000

Cytokine expression and production by purified Helicobacter pylori urease in human gastric epithelial cells.

Cytokines have been proposed to play an important role in Helicobacter pylori-associated gastroduodenal diseases, but the exact mechanism of the cytokine induction remains unclear. H. pylori urease, a major component of the soluble proteins extracted from bacterial cells, is considered to be one of the virulence factors for the inflammation in the gastric mucosa that is produced in H. pylori infection. However, the response of human gastric epithelial cells to the stimulation of urease has not been investigated. In the present study, we used human gastric epithelial cells in a primary culture system and examined whether H. pylori urease stimulates the gastric epithelial cells to induce proinflammatory cytokines by reverse transcription-PCR and enzyme-linked immunosorbent assay. First, by using peripheral blood mononuclear cells (PBMC) and a gastric cancer cell line (MKN-45 cells), we confirmed the ability of purified H. pylori urease to induce the production of proinflammatory cytokines. Furthermore, we demonstrated that the human gastric epithelial cells produced interleukin-6 (IL-6) and tumor necrosis factor alpha, but not IL-8, following stimulation with purified urease. The patterns of cytokine induction differed among human PBMC, MKN-45 cells, and human gastric epithelial cells. These results suggest that the human gastric epithelial cells contribute to the induction of proinflammatory cytokines by the stimulation of H. pylori urease, indicating that the epithelial cells were involved in the mucosal inflammation that accompanied H. pylori infection.

Adult↗
PubMed2000

Comparison of PCR-restriction fragment length polymorphism analysis and PCR-direct sequencing methods for differentiating Helicobacter pylori ureB gene variants.

A method utilizing PCR-restriction fragment length polymorphism (RFLP) in the Helicobacter pylori genes is widely used to differentiate strains. However, with this typing method only a single base change at a specific restriction site can be detected. In addition, it is unclear whether the nucleotide base change recognized by RFLP is related to a substitution of encoded amino acid. To examine the validity of the PCR-RFLP method, 933-bp PCR products were obtained from 41 different clinical H. pylori isolates and were digested with Sau3A restriction endonuclease. Furthermore, the nucleotides of the same region in the ureB gene were directly sequenced and compared. PCR-RFLP confirmed that there was genetic diversity within the ureB gene with three distinct types, one being well conserved and the other two being variations. However, the direct sequencing method revealed that there was no difference at the nucleotide level among these RFLP types. Base substitutions recognized by Sau3A occurred in the third-base position and did not change the encoded amino acid. In addition, many nucleotide mutations, which could not be recognized by Sau3A, were frequently found. These results suggest that the PCR-RFLP method provides for an easy typing scheme of isolates, but does not reveal the true extent of genetic diversity. It is proposed that careful observation is required for the interpretation of results when clinical isolates are differentiated.

Base Sequence↗
PubMed2000

Quaternary isoquinoline alkaloids from Stephania cepharantha.

From the quaternary alkaloidal fraction of the dried tubers of Stephania cepharantha, two new isoquinoline alkaloids, stecepharine and tetradehydroreticuline have been isolated along with the known compounds, magnoflorine, menisperine, steponine, cyclanoline, oblongine, cis-N-methylcapaurine and 2'-N-methylisotetrandrine. cis-N-Methylcapaurine (=9-O-methylstecepharine) was isolated as a natural product for the first time. Their structures were determined on the basis of spectroscopic evidence.

Alkaloids↗
PubMed2000

A tetrahydroisoquinoline-monoterpene glucoside and an iridoid glucoside from Alangium kurzii.

From the leaves of Alangium kurzii, a new tetrahydroisoquinoline-monoterpene glucoside, 6-O-methyl-N-deacetylipecosidic acid and a new iridoid glucoside, 10-O-benzoyladoxosidic acid, were isolated along with alangiside, demethylalangiside, 6''-O-beta-D-glucosylhenryoside, uridine and four known flavonoid glycosides. The structures of new glucosides were determined on the basis of spectroscopic and chemical methods.

Acetylation↗
PubMed2000

Overt congestive heart failure with mitral and aortic regurgitation due to antiphospholipid syndrome in a patient with systemic lupus erythematosus.

A 51-year-old woman with overt congestive heart failure with pleural and pericardial effusion was treated with furosemide and nifedipine, leading to improvement in her condition and a decrease in effusions. An echocardiography demonstrated mitral and aortic regurgitation with mitral valve prolapse, which caused the congestive heart failure. Since leukocytopenia and lymphocytopenia with arthralgia could be observed, serological investigations were performed. She was diagnosed as having systemic lupus erythematosus (SLE) with antiphospholipid syndrome, and started on a treatment of prednisolone and aspirin. Based on the treatment, the pleural and pericardial effusion went into complete remission, indicating that the serositis related to SLE had overlapped the heart failure. Since there was no evidence of any other diseases that could be responsible for the valvular lesions, we concluded that they were due to antiphospholipid syndrome. The administration of prednisolone had no significant effect on valvular morphology or function as demonstrated by echocardiography. When patients with valvular disease are seen, a valvulopathy related to antiphospholipid syndrome should be considered as part of the differential diagnosis.

Antiphospholipid Syndrome↗
PubMed2000

Secoiridoid glucosides from Fraxinus americana.

Investigation of the leaves of Fraxinus americana led to the isolation of five secoiridoid glucosides, demethylligstroside, (2"R)- and (2"S)-2"-hydroxyoleuropeins, fraxamoside and frameroside, together with 18 known compounds. Their structures were determined on the basis of spectroscopic studies and chemical evidence.

Journal Article↗
PubMed2000

Secoiridoid glucosides from Fraxinus americana.

Investigation of the leaves of Fraxinus americana led to the isolation of five secoiridoid glucosides, demethylligstroside, (2"R)- and (2"S)-2"-hydroxyoleuropeins, fraxamoside and frameroside, together with 18 known compounds. Their structures were determined on the basis of spectroscopic studies and chemical evidence.

Glucosides↗
PubMed1999

Ipecac alkaloids from Cephaelis acuminata.

From the dried roots of Cephaelis acuminata, five ipecac alkaloids, neocephaeline, 7'-O-demethylcephaeline, 10-O-demethylcephaeline, 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)cephaeline and 2'-N-(1"-deoxy-1"-beta-D-fructopyranosyl)neocephaeline, were isolated, along with emetine, cephaeline, psychotrine, protoemetine, 9-demethylprotoemetinol and isocephaeline. Structures were determined by spectroscopic and chemical means.

Ipecac↗
PubMed1999

Three secoiridoid glucosides from Jasminum nudiflorum.

Phytochemical study of the leaves and stems of Jasminum nudiflorum has led to the isolation of three secoiridoid glucosides, jasnudiflosides A-C (1-3). The structures of these compounds were elucidated on the basis of chemical and spectroscopic evidence.

Carbohydrate Conformation↗
PubMed1999

Carcinosarcoma of the ampulla of Vater: a case report with immunohistochemical and ultrastructural studies.

Carcinosarcoma of the duodenum has not been reported previously, although this type of tumor has been detected in other organs. We present here a case of carcinosarcoma of the duodenum, including immunohistochemical and electron microscopical findings. An ulcerating tumor, located in the duodenal ampullary region, contained two divergent components: ordinary differentiated tubular adenocarcinoma, and sarcomatoid tissue composed of spindle tumor cells. Immunohistochemically, the adenocarcinoma cells were stained with antibodies against epithelial markers including keratin and CA19-9. In contrast, the sarcomatoid tissue was strongly positive for vimentin and was focally positive for myoglobin, keratin, and CA19-9. We speculate that the sarcomatoid element of the carcinosarcoma arose from part of the ordinary adenocarcinoma tissue.

Ampulla of Vater↗