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Biomedical subjects

Y Takeda

Publications and source records attributed to Y Takeda.

At least 127 records · Page 7Linked to original sources
PubMed2001

Concomitant infection of enterotoxigenic Escherichia coli in an outbreak of cholera caused by Vibrio cholerae O1 and O139 in Ahmedabad, India.

In Ahmedabad, a major city in the state of Gujarat, India, an outbreak of acute secretory diarrhea caused by Vibrio cholerae O1 Ogawa El Tor, V. cholerae O139, and multiple serotypes of enterotoxigenic Escherichia coli (ETEC) occurred in January 2000. All of the representative V. cholerae O1 and O139 isolates examined harbored the ctxA gene (encoding the A subunit of cholera toxin) and the El Tor variant of the tcpA gene (encoding toxin-coregulated pilus). ETEC isolates of different serotypes were positive for the elt gene, encoding heat-labile enterotoxin. To further understand the molecular characteristics of the pathogens, representative isolates were examined by ribotyping and pulsed-field gel electrophoresis (PFGE). Ribotyping showed that the isolates of V. cholerae O1 Ogawa exhibited a pattern identical to that of the prevailing clone of O1 in areas where cholera is endemic in India, and all of the O139 isolates were identical to the BII clone of V. cholerae O139. PFGE of the representative O1 Ogawa isolates exhibited an identical pattern, comparable to the H pattern of the new clone of O1 reported in Calcutta, India. PFGE analysis of the V. cholerae O139 isolates showed identical patterns, but these differed from the PFGE patterns of O139 isolates reported during 1992 to 1997 in Calcutta. ETEC isolates showed genetic heterogeneity among isolates belonging to the same serotype, although the identical PFGE pattern was also observed among ETEC isolates of different serotypes. Antibiograms of the isolates were unusual, because all of the O139 isolates were resistant to nalidixic acid. Likewise, all of the E. coli isolates showed resistance to ciprofloxacin, norfloxacin, and nalidixic acid. This is a unique outbreak, and we believe that it is the first in which V. cholerae and ETEC were concomitantly involved.

Anti-Bacterial Agents↗
PubMed2001

Molecular dissection of hepatitis C virus expression.

OBJECTIVE: The 5' untranslated region (5' UTR) of the hepatitis C virus genome is thought to be important for the control of viral gene expression and a likely target for therapeutic interception. A functional role of this viral gene segment was analyzed both in vivo and in vitro. METHODS: Transgenic mice carrying a reporter gene that contains the complete 5' UTR sequence were made. Cellular protein(s) which associate with the 5' UTR were analyzed by gel shift analysis and a following affinity purification. RESULTS: Transgenic mice revealed protein accumulation only in periportal hepatocytes around the portal triad and not in perivenous hepatocytes around the central vein. Gel shift analysis using mouse liver extracts provides further evidence that trans-acting proteins, which recognize a specific cis-acting element with the 5' UTR (an apparent stemmed structure formed by two noncontiguous RNA sequences), are present in adult mice but not in young mice. A similar 5' UTR RNA-protein complex was also detected with human liver extracts. CONCLUSION: The presence of cellular factor(s) which allow HCV 5' UTR to express in tissue and differentiation state-specific manner was suggested.

5' Untranslated Regions↗
PubMed2001

Involvement of bradykinin and nitric oxide in leptin-mediated glucose uptake in skeletal muscle.

Regulation of glucose metabolism in peripheral tissues by leptin has been highlighted recently, although its mechanism is unclear. In this study, we postulated that bradykinin and nitric oxide (NO) are involved in the effect of leptin-mediated glucose uptake in peripheral tissues and examined these possibilities. Injection of leptin (200 pg/mouse) into the ventromedial hypothalamus-enhanced glucose uptake in skeletal muscle and brown adipose tissue, but not in white adipose tissue. Treatment with Hoe140 (0.1 mg/kg), bradykinin B2 receptor antagonist, or L-NAME (N:(G)-nitro-L-arginine methyl ester) (30 mg/kg), nitric oxide synthase inhibitor, did not influence the basal level of glucose uptake in skeletal muscle and the adipose tissue, whereas Hoe140 and L-NAME inhibited leptin-mediated glucose uptake in skeletal muscles, but had no effect in adipose tissue. However, Hoe140 and L-NAME did not inhibit insulin (1.0 U/kg)-mediated glucose uptake in all tissues examined. Taken together, these results suggest that leptin enhances bradykinin and/or the NO system, which contributes at least partially to the enhanced glucose uptake in skeletal muscles.

Animals↗
PubMed2001

Phlomisflavosides A and B, new flavonol bisglycosides from Phlomis spinidens.

From the aerial parts of Phlomis spinidens, two new flavonol bisglycosides, phlomisflavosides A (1) and B (2), were isolated together with the known compounds, astragalin, isoquercitrin, lamiridoside, phlomoside A, shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, phlorigidoside C, rodioloside (=salidroside), forsythoside B, citroside A and lariciresinol-4'-O-beta-D-glucoside. The structures of the new compounds were elucidated based on spectral and chemical evidence.

Flavonoids↗
PubMed2001

Myrsinionosides A-E: megastigmane glycosides from the leaves of Myrsine seguinii Lev.

Eight megastigmane glycosides were isolated from the leaves of Myrsine seguinii collected in Okinawa. Three of them were found to be known compounds, i.e., ampelopsisionoside, alangionoside J, and linarionoside A. The structures of the new megastigmane glycosides were elucidated from the spectroscopic data and their absolute stereochemistries were determined in detail using a modified Mosher's method.

Acetylation↗
PubMed2001

Farnesyl hydroxybenzoic acid derivatives from Ferula kuhistanica.

Four new farnesyl hydroxybenzoic acid derivatives, kuhistanols E-H (1-4), were isolated from the roots of the Uzbekistan medicinal plant Ferula kuhistanica. The structures of the new compounds were elucidated based on spectroscopic and chemical evidence.

Apiaceae↗
PubMed2001

Major isoforms of starch branching enzymes in premature seeds of kidney bean (Phaseolus vulgaris L.).

Developing seeds of the kidney bean (Phaseolus vulgaris L.) contain several isoforms of starch branching enzymes. Two of them, KBE1 and KBE2, which are the major forms in the premature seeds, were purified as a single band of protein on SDS-PAGE and native PAGE by chromatographies on DEAE-Sepharose, Bio-Gel P-200, and amylose-binding Sepharose 6B. The enzymes had similar pH optimum (7.0), pH stability (7.0-9.5), temperature optimum (25-30 degrees C), and temperature stability (up to 40 degrees C). Additionally, both were inhibited by various divalent metal ions and activated by citrate. Finally, though their N-terminal amino acid sequences were identical, their molecular masses and affinities for amylose differed; 80 kDa and 1.27 mM for KBE1 and 77 kDa and 0.74 mM for KBE2.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2001

Isolation and antioxidant activity of galloyl flavonol glycosides from the seashore plant, Pemphis acidula.

Four kinds of galloyl flavonol glycosides were found in the leaf extract of Pemphis acidula, a plant growing on the subtropical seashore. Their chemical structures were elucidated to be quercetin or kaempferol 6"-O-galloyl-beta-D-glycosides by using spectroscopic and chemical analyses. One of the flavonols, kaempferol-3-O-(6-O-galloyl-beta-D-galactopyranoside), was newly isolated from natural sources and its structure was completely determined in this investigation. The antioxidant-related activities of the galloyl flavonoids were examined by the DPPH antiradical activity, inhibition of methyl linoleate oxidation, and inhibition of oxidative cell death. These results were compared with those of the corresponding non-galloylated flavonol glycosides and their aglycones. The galloyl flavonoids showed more efficient activity than that of the corresponding flavonol glycosides, but not more than that of the corresponding aglycones in the three assays applied.

Africa↗
PubMed2001

Genetic alterations in patients with primary aldosteronism.

The syndrome of primary aldosteronism is characterized by hypertension with excessive production of aldosterone, potassium loss, and suppression of the renin-angiotensin system. The most common clinical subtypes of primary aldosteronism are aldosterone-producing adrenocortical adenoma (APA) and bilateral adrenal cortical hyperplasia (idiopathic hyperaldosteronism, or IHA). It has been reported that renin suppression and aldosterone levels are lower and hypokalemia milder in patients with IHA than in patients with APA. In the present study, we investigated the genetic analysis of aldosterone synthase gene, CYP11B2 in patients with primary aldosteronism and review the recent studies. The chimeric CYP11B1/CYP11B2 gene, which is a candidate gene for glucocorticoid-remediable hyperaldosteronism, was not found in either the DNA from aldosteronoma or in the genomic DNA from patients with APA or IHA. Mutations in the CYP21 or CYP11B1 gene were not present in patients with APA. No mutations in the coding region of the CYP11B2 gene were found in patients with IHA or APA. The level of CYP11B2 messenger RNA (mRNA) was much higher in the aldosteronoma portion than in nonadenomatous portion. The overexpression of CYP11B2 mRNA seen in the mononuclear leukocytes of patients with IHA suggests that unidentified aldosterone-stimulating factors or abnormalities of the CYP11B2 promoter region may cause the overproduction of aldosterone characteristic of IHA. The variants of the CYP11B2 gene may also contribute to dysregulation of aldosterone synthesis and lead to susceptibility to IHA.

Cytochrome P-450 CYP11B2↗
PubMed2001

The roles of cell adhesion molecules on the formation of peripheral myelin.

Several cell adhesion molecules of the immunoglobulin superfamily (IGSF) are expressed differently during the development and myelination of the peripheral nervous system. To examine the relationship between the expression of IGSF molecules and Schwann cell differentiation, we established a useful system for myelin formation in vitro on collagen gel using primary neuron/Schwann cell co-cultures from neonatal dorsal root ganglions (DRG). At 10 days in vitro (DIV), many Schwann cells were found in the areas surrounding aggregates of DRG neurons. After 20 DIV, Schwann cells positioned next to axons and elongated their processes along the axons. Some of them started loosely elaborating a large axon. Under electron microscopy, compact myelin was shown to be formed at 30 DIV. Thus the speed of myelination was much slower in vitro than in vivo. In co-cultures, L1 and neural cell adhesion molecule (NCAM) were detected at the premyelinating stage, L1 was precisely expressed earlier than NCAM. Expression of myelin associated glycoprotein (MAG) was transiently up-regulated at the early stage of myelination, and then P0 expression was finally increased as myelination proceeded. The change of expression pattern of these molecules in co-cultures was quite similar to that observed in the development in vivo. When Schwann cell proliferation was blocked by low serum culture condition, L1 and NCAM expressions were up-regulated. In contrast, the presence of cholera toxin in low serum media markedly increased expressions of P0 and MAG, but decreased the levels of both L1 and NCAM. These results suggest that both L1 and NCAM play roles in the contact and/or recognition between axons and Schwann cells at an early stage of myelination. On the other hand, MAG and P0 are important for axon ensheathment and myelin compaction.

Animals↗
PubMed2001

Papillary squamous cell carcinoma of the oral mucosa: immunohistochemical comparison with other carcinomas of oral mucosal origin.

Papillary squamous cell carcinoma (PSCC) is a poorly described variant of squamous cell carcinoma, and may be confused with verrucous carcinoma of the head and neck. To add to existing knowledge of this rare tumor, we describe two cases of PSCC arising in the oral mucosa. The lesions were composed of exophytic proliferation of atypical to overtly malignant cells similar to those of conventional squamous cell carcinoma, and invasion into the superficial region of the underlying fibrous tissue was seen in the form of islands and cords of malignant cells. Immunohistochemical assessment of cellular proliferative activity showed a significantly high mean percentage of Ki-67 expression in comparison with verrucous carcinoma, but there was no significant difference of Ki-67 expression among PSCC, conventional squamous cell carcinoma and microinvasive squamous cell carcinoma. These results suggest that the biological behavior of PSCC is analogous to that of SCC.

Aged↗
PubMed2001

An unusual staining of the tooth roots: a case report with histological and micro-analytical studies.

The discoloration of tooth roots is rare. We report here a 22-year-old Japanese woman with blackish-brown staining of the roots of the upper and lower third molars. Staining was found in the dentin and cementum. Electron probe X-ray microanalysis showed no significant difference in the composing elements between the stained tooth root and control tooth. Fluorescent bands coincided with staining in the dentin of the root and cementum along the incremental lines under confocal laser-scanning microscope.

Adult↗
PubMed2001

Histological and analytical studies of a tooth in a patient with cleidocranial dysostosis.

A histopathological and analytical study of a permanent tooth from a patient with cleidocranial dysostosis (CCD) was performed. The patient was a 47-year-old woman, who had 10 erupted permanent teeth and 2 partially erupted and 19 completely impacted teeth, including supernumerary teeth. The erupted right upper premolar was extracted and observed using a light microscope and an electron probe X-ray microanalyzer (EPMA). Findings showed enamel hypoplasia, predominantly irregular globular dentin and Tomes' granular layer, and a complete lack of cellular cementum in the ground section. The incremental von Ebner and counter Owen lines were obscure. Comparative quantitative analysis using the EPMA showed that the quantities of calcium and phosphate were lower in the enamel and dentin than those of the control sample.

Bicuspid↗
PubMed2001

Salivary duct cyst: its frequency in a certain Japanese population group (Tohoku districts), with special reference to adenomatous proliferation of the epithelial lining.

It is reported in the European and American literature that salivary duct cysts constitute about 10% of all cysts of the salivary glands, although they appear to be rare in Japan. Between 1975 and 1999, only 3 (0.5%) of 586 salivary gland cysts were diagnosed as salivary duct cysts at the Division of Clinical Pathology, Iwate Medical University Hospital. Histologically, two cases appeared as a unilocular lesion lined by double- and multi-layered epithelium. The other case showed marked, intraluminar and intramural adenomatous proliferation of the epithelial lining, suggesting that the lesion was a benign tumor. A review of the literature yielded only two cases of tumors arising in pre-existing salivary duct cysts.

Adult↗
PubMed2001

[Determination method of polysorbates in powdered soup by HPLC].

A method for qualitative and quantitative analyses of polysorbates in powdered soup by HPLC was studied. Polysorbates in samples were extracted with acetonitrile after rinsing with n-hexane to remove fats and oils. The extract was cleaned up using a Bond Elut silica gel cartridge (500 mg). The cartridge was washed with ethyl acetate and polysorbates were eluted with a small amount of acetonitrile-methanol (1:2) mixture. The eluate was treated with cobalt thiocyanate solution to form a blue complex with polysorbate. In order to determine polysorbate, the complex was subjected to HPLC with a GPC column, using a mixture of acetonitrile-water (95:5) as a mobile phase, with a detection wavelength of 620 nm. The recoveries of polysorbate 80 added to powdered soups were more than 75% and the determination limit was 0.04 mg/g. When the proposed method was applied to the determination of polysorbates in 16 commercial samples of powdered soup for instant noodles and seasoning consomme, no polysorbates were detected in any sample.

Chromatography, High Pressure Liquid↗