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Biomedical subjects

Y Takeda

Publications and source records attributed to Y Takeda.

At least 181 records · Page 10Linked to original sources
PubMed2000

Nontumorous decrease in Tc-99m GSA accumulation.

Nontutimorous decrease in 99mTc-GSA accumulation has not been well covered in the literature. Understanding of this phenomenon is, however, essential for accurate evaluation of regional hepatic function. Scintigrams (transaxial SPECT) of 269 patients who underwent 99mTc-GSA liver scintigraphy were reviewed for the presence of nontumorous decreases in 99mTc-GSA accumulation. Nontumorous decreases in 99mTc-GSA accumulation were seen in 32 of 269 patients (12%). In 16 of the 32 patients (6%), nontumorous decreases in 99mTc-GSA accumulation corresponded to regional decrease in portal venous flow. The causes of such decrease in portal venous flow were portal thrombus of hepatocellular carcinomas in eight patients, portal venous stenosis or occlusion by hilar cholangiocarcinomas in five patients, inter alia. In eight patients (3%), the regions with decreased 99mTc-GSA accumulation correlated with massive hepatic necrosis in fulminant hepatitis, scar in hepatitis, or confleuent in portal venous flow, lobar biliary stasis, or both. In four patients (1.5%), the exact causes of nontumorous decrease in 99mTc-GSA accumulation could not be determined.

Adult↗
PubMed2000

Improved recovery of trace amounts of gold (III), palladium (II) and platinum (IV) from large amounts of associated base metals using anion-exchange resins.

The adsorption and desorption behaviors of gold (III), palladium (II) and platinum (IV) were surveyed in column chromatographic systems consisting of one of the conventional anion-exchange resins of large ion-exchange capacity and dilute thiourea solutions. The noble metals were strongly adsorbed on the anion-exchange resins from dilute hydrochloric acid, while most base metals did not show any marked adsorbability. These facts made it possible to separate the noble metals from a large quantity of base metals such as Ag (I), Al (III), Co (II), Cu (II), Fe (III), Mn (II), Ni (II), Pb (II), and Zn (II). Although it used to be very difficult to desorb the noble metals from the resins used, the difficulty was easily overcome by use of dilute thiourea solutions as an eluant. In the present study, as little as 1.00 microg of the respective noble metals was quantitatively separated and recovered from as much as ca. 10 mg of a number of metals on a small column by elution with a small amount of dilute thiourea solution. The present systems should be applicable to the separation, concentration and recovery of traces of the noble metals from a number of base metals coexisting in a more extended range of amounts and ratios.

Journal Article↗
PubMed2000

Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion.

This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn.

Adult↗
PubMed2000

Brunner's gland adenoma with a focus of p53-positive atypical glands.

A submucosal tumor was resected endoscopically from the duodenal bulb in a 43-year-old man complaining of epigastric discomfort. The tumor, measuring 22 x 20 x 19mm, consisted mainly of Brunner's glands with no atypia. However, close histologic examination disclosed a focus of glands with cellular and structural atypia. The atypical glands showed staining by periodic acid-Schiff, alcian blue, and high iron-diamine methods. Mucin histochemistry was examined, and the atypical glands resembled the excretory ducts rather than the acinar cells of the tumor. Immunohistochemically, positivity for MIB-1 was high (38.0%), and p53-positive cells were detected sporadically in the atypical glands. These results indicated that the atypical glands probably represented a neoplastic lesion. Brunner's gland adenomas associated with foci of true neoplasm are very rare; only two cases, including one patient with microcarcinoid tumors, have been reported.

Adenoma↗
PubMed2000

A new variant deletion of a copper-transporting P-type ATPase gene found in patients with Wilson's disease presenting with fulminant hepatic failure.

A candidate gene (ATP7B) for Wilson's disease, an autosomal recessive disorder of copper transport, has recently been identified. We examined the ATP7B gene in two Japanese sisters with Wilson's disease presenting with fulminant hepatic failure but who did not exhibit Kayser-Fleischer rings or abnormal neurological findings. Genomic DNA was isolated from the whole blood of the patients and their family. Entire exons of ATP7B, and their associated splice junctions, were amplified by polymerase chain reaction. The sequencing of all exons was performed by a non-radioactive sequencing method. The sequencing of exon 12 of ATP7B revealed a 9-bp deletion. The mutation deleted 922Gly, 923Tyr, and 924Phe, and three residues conserved in the Menkes gene, ATP7A, located in the fifth transmembrane region. Of the 14 family members tested, 7 were normal and 7 were heterozygous for the deletion. Mean serum copper and cerulopasmin levels were significantly lower in the family members who were heterozygous for the deletion than in the normal family members, and two heterozygous family members showed abnormally low ceruloplasmin levels; however, there were no differences in mean aspartate aminotransferase or alanine aminotransferase levels between the two groups.

Adenosine Triphosphatases↗
PubMed2000

Sesquiterpenoids from Ferula kuhistanica.

Methanol extracts of the air-dried roots and stems of Ferula kuhistanica afforded seven daucane-type sesquiterpenes, called kuhistanicaol A-G, together with 13 known daucane esters. Their structures were established on the basis of spectroscopic evidence and the results of chemical reactions.

Apiaceae↗
PubMed2000

Iridoid glycosides from Lonicera quinquelocularis.

A new iridoid glycoside 6'-O-beta-apiofuranosylsweroside was isolated from the ethanolic extract of the roots of Lonicera quinquelocularis along with the known compounds loganin and sweroside.

Disaccharides↗
PubMed2000

Phlorigidosides A-C, iridoid glucosides from Phlomis rigida.

From the aerial parts of Phlomis rigida, three iridoid glucosides, phlorigidoside A (2-O-acetyllamiridoside), B (8-O-acetyl-6-beta-hydroxyipolamide) and C (5-deoxysesamoside), were isolated together with the known iridoid glucosides, shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, deoxypulcheloside I, lamiridoside, and 6-beta-hydroxyipolamide. The structures of the new compounds were elucidated based on spectral and chemical evidence.

Glucosides↗
PubMed2000

Coumarins and bicoumarin from Ferula sumbul: anti-HIV activity and inhibition of cytokine release.

The methanol extract of the dried roots of Ferula sumbul afforded two furanocoumarin esters, fesumtuorin A, B, one bicoumarin, fesumtuorin C, five spirobicoumarins, fesumtuorin D, E, F, G and H, along with nineteen known coumarins. Their structures were established on the basis of spectroscopic studies. Some of the isolated compounds showed anti-HIV activity and very weak inhibition of cytokine release.

Anti-HIV Agents↗
PubMed2000

Ex vivo measurement of tissue distribution of a nitroxide radical after intravenous injection and its in vivo imaging using a rapid scan ESR-CT system.

To establish the usefulness of ESR-CT imaging with 3-carbamoyl-2,2,5, 5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL) in living animals, we investigated the tissue distribution of carbamoyl-PROXYL after i. v. injection. Ten minutes after injection of carbamoyl-PROXYL, its concentrations in the liver, spleen, kidney, and plasma were higher than those in the small intestine and stomach. However, the inter-organ differences in concentrations were not striking. We selected the liver as a representative organ and attempted to measure the concentration of carbamoyl-PROXYL in it after washing out all of the blood by in situ perfusion with saline. The ESR spectrum of the liver homogenate after complete blood washout revealed that the concentration of carbamoyl-PROXYL was significantly reduced. Thus, at this time, carbamoyl-PROXYL was distributed predominantly in the plasma and/or loosely attached to the surfaces of cells. We obtained high-quality ESR-CT images of the murine abdomen at a measurement time of 40 s and found that a high-intensity area of carbamoyl-PROXYL appeared in the liver and kidneys, indicating an abundant blood circulation. Although the organ specificity of carbamoyl-PROXYL was weak, we consider that ESR-CT imaging with carbamoyl-PROXYL will be a powerful new tool for non-invasive anatomic analysis of the liver and the kidneys.

Animals↗
PubMed2000

Idiopathic hyperaldosteronism: analysis of aldosterone synthase gene.

We analyzed the CYP11B2, the gene encoding aldosterone synthase, in mononuclear leukocytes in eight patients with primary aldosteronism due to zona glomerulosa hyperplasia (idiopathic hyperaldosteronism) and compared the results with aldosterone-producing adenomas. In idiopathic hyperaldosteronism, aldosterone synthase activity was significantly increased in accordance with gene expression (P < 0.05), compared with aldosterone-producing adenomas. No genetic mutations were found in coding regions of DNA. The T (-344) C allele polymorphism was present in a similar frequency in the general population. In one patient with idiopathic hyperaldosteronism. de novo homozygous mutation in upstream of the 5' flanking region C (-463) T was detected, which cannot be explained by polymorphism. The pathophysiological significance of this mutation for aldosterone hypersecretion is not known. There were no mutations in the known promoter sequences for angiotensin II related cis-segments. Possible contribution of co-regulators for angiotensin 11-induced signalling pathway is discussed.

Adenoma↗
PubMed2000

Dysfunctional regulation of the development of monocyte-derived dendritic cells in cancer patients.

Dendritic cells (DCs) are highly effective antigen (Ag)-presenting cells (APCs) that are required for the initiation of the immune response. DCs derived from cancer patients have been shown to be defective in several phenotypic and functional properties. However, little is known about the capacity of monocytes derived from cancer patients to differentiate into DCs. Herein, we examined the differentiation of monocyte-derived DCs in cancer patients. Flow cytometric analysis revealed that monocytes derived from cancer patients cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) plus interleukin-4 (IL-4) exhibited lower levels of CD11c, CD40, CD86, and HLA-DR expression as compared with those of monocyte-derived DCs from healthy volunteers. Furthermore, the capacities of DCs derived from cancer patients' monocytes to stimulate allogeneic T cell responses and to migrate in response to regulated-on-activation normal T cells expressed and secreted (RANTES) were impaired in comparison with those of monocyte-derived DCs from healthy volunteers. However, the two cell types had similar pinocytotic capacities for fluorescein isothiocyanate labeled-dextran (FITC-DX) and lucifer yellow (LY). These results suggest that monocytes from cancer patients may be defective in the capacity to develop into DCs.

Aged↗
PubMed2000

Expanding multiple antibiotic resistance among clinical strains of Vibrio cholerae isolated from 1992-7 in Calcutta, India.

Antimicrobial susceptibilities of Vibrio cholerae strains isolated from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India for 6 years were analysed to determine the changing trends; 840 V. cholerae strains isolated in 1992-1997 were included in this study. Among V. cholerae serogoup O1 and O139, ampicillin resistance increased from 1992 (35 and 70%, respectively) to 1997 (both serogroups 100%). Resistance to furazolidone and streptomycin was constantly high among V. cholerae O1 strains with gradual increase in resistance to other drugs such as ciprofloxacin, co-trimoxazole, neomycin and nalidixic acid. V. cholerae O139 strains exhibited susceptibilities to furazolidone and streptomycin comparable with those of O1 strains. However, after initial increase in resistance to chloramphenicol and co-trimoxazole, all the V. cholerae O139 strains became susceptible to these two drugs from 1995 onwards. Both V. cholerae O1 and O139 remained largely susceptible to gentamicin and tetracycline. V. cholerae non-O1, non-O139 strains, in contrast, exhibited high levels of resistance to virtually every class of antimicrobial agents tested in this study especially from 1995. Kruskal-Wallis one-way analysis showed that V. cholerae O1 Ogawa serogroup exhibited significant yearly increase in resistance to nine antibiotics followed by non-O1 non-O139 and O139 strains to six antibiotics and two antibiotics respectively. Interesting observation encountered in this study was the dissipation of some of the resistant patterns commonly found among V. cholerae non-O1 non-O139 or O1 serogroups to the O139 serogroup and vice versa during the succeeding years.

Cholera↗
PubMed2000

Clonal dissemination of Vibrio parahaemolyticus displaying similar DNA fingerprint but belonging to two different serovars (O3:K6 and O4:K68) in Thailand and India.

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, showed the appearance of the O4:K68 serovar for the first time in March 1998 alongside the continued predominant incidence of the O3:K6 serovar. Strains belonging to both these serovars have been reported to possess pandemic potential. The genomes of O3:K6 and O4:K68 strains and for comparison, non-O3:K6 and non-O4:K68 strains isolated from two different countries, India and Thailand, were examined by different molecular techniques to determine their relatedness. The O3:K6 and O4:K68 strains from Calcutta and Bangkok carried the tdh gene but not the trh gene. Characterization of representative strains of these two serovars by ribotyping and by arbitrarily primed-polymerase chain reaction (AP-PCR) showed that the isolates had identical ribotype and DNA fingerprint. Pulsed-field gel electrophoresis (PFGE) performed with the same set of strains yielded nearly similar restriction fragment length polymorphism (RFLP) patterns for the O3:K6 and O4:K68 isolates from Calcutta and Thailand. Phylogenetic analysis of the NotI RFLP showed that the O3:K6 and O4:K68 strains formed a cluster with 78-91% similarity thus indicating close genetic relationship between the two different serovars isolated during the same time-frame but from widely separated geographical regions. The non-O3:K6 and non-O4:K68, in contrast, showed different ribotype, AP-PCR and PFGE patterns.

DNA Fingerprinting↗
PubMed2000

C(18) acetylenic fatty acids of Ximenia americana with potential pesticidal activity.

Bioactivity-driven fractionation of the CHCl(3) extract of the root of Ximenia americana, using the brine shrimp lethality test (BST) and hatchability test with Clavigralla tomentosicollis eggs, gave C(18) acetylenic fatty acids 1 and 2. 1 is octadeca-5-ynoic acid (tariric acid). 2 is a novel ene-ene-yne-ene acetylenic fatty acid (10Z,14E,16E-octadeca-10,14,16-triene-12-ynoi c acid). The structures of 1 and 2 were assigned from the MS and NMR data. Fractions that are rich in acetylenic fatty acids inhibited the hatching of C. tomentosicollis eggs.

Acetylene↗
PubMed2000

Isolation and structure determination of new antioxidative ferulic acid glucoside esters from the rhizome of Alpinia speciosa, a Zingiberaceae plant used in Okinawan food culture.

An assay-guided isolation gave three antioxidants including two newly identified compounds from the rhizomes of Alpinia speciosa, which is used as an important plant in the food culture of the Okinawa area of Japan. Spectroscopic analysis of the two new compounds revealed them to be new glucoside esters of ferulic acid. The antioxidant activity of the esters was measured using two different methods. Both compounds showed greater activity than that of Trolox in the TLC method; however, one of the compounds showed weaker inhibitory activity than that of Trolox and epicatechin against AMVN-induced methyl linoleate oxidation.

Antioxidants↗
PubMed2000

Sesquiterpene coumarins and related derivatives from Ferula pallida.

Six new compounds-two sesquiterpene coumarins, pallidones A and B (1, 2), and four related derivatives, pallidones C-F (3-6), as well as two known sesquiterpene coumarins, feselol (7) and conferol (8), have been isolated from the EtOAc extracts of the roots of Ferula pallida. All structures of these compounds were determined on the basis of spectral evidence, especially 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and NOESY) and HRMS. The possible biosynthetic pathway of pallidones C-F (3-6) is discussed.

Coumarins↗