Screening and Identification of Disaccharides with Insulin Mimetic Activity against L6 Cells

Insulin mimetics are considered as prospective anti-diabetic agents, and the disaccharide, neohesperidose, has been found to show insulin mimetic activity against L6 cells. We screened several other disaccharides for their insulin mimetic activity and identified three new insulin mimetic disaccharides

Synthesis and α-amylase inhibitory activity of glucose–deoxynojirimycin conjugates

Inhibitors of α-amylase have attracted attention for their putative effects against diabetes mellitus. Although numerous studies have explored natural small molecule inhibitors, acarbose is currently the only compound with sufficient inhibitory potency and drug-like characteristics to be considered as a potential therapeutic agent. We have synthesized conjugates of the potent glucosidase inhibitor, 1-deoxynojirimycin, and glucose, with the aim of enhancing inhibitory activity against α-amylase. This synthetic conjugate showed increased inhibition of α-amylase compared to 1-deoxynojirimycin alone, suggesting that similar modifications of existing glucosidase inhibitors may yield more potent α-amylase inhibitors

Preparation of Mullite Dispersed Silica Ceramics through Sol-Gel Processing

Mullite-dispersed silica ceramics were prepared through sol-gel processing by the use of tetraethoxy silane, aluminium nitrate and aluminium isopropoxide as the Si and Al sources where HCl and HN0(3) were the catalyst. Effect of the starting materials, solvents and catalysts was examined on the gelation time or temperature of mullite precipitation. Apparent activation energy of gelation ranged from 80 to 95kJ/mol. The presence of AI in the sols elongated the gelling time suggesting the formation of chelate bonds between AI and Si-OR or Si-OH bonds

Three novel oligosaccharides synthesized using Thermoanaerobacter brockii kojibiose phosphorylase

<p>Abstract</p> <p>Background</p> <p>Recently synthesized novel oligosaccharides have been produced primarily by hydrolases and glycosyltransferases, while phosphorylases have also been subject of few studies. Indeed, phosphorylases are expected to give good results via their reversible reaction. The purpose of this study was to synthesis other novel oligosaccharides using kojibiose phosphorylase.</p> <p>Results</p> <p>Three novel oligosaccharides were synthesized by glucosyltransfer from β-D-glucose 1-phosphate (β-D-G1P) to xylosylfructoside [<it>O</it>-α-D-xylopyranosyl-(1→2)-β-D-fructofuranoside] using <it>Thermoanaerobacter brockii </it>kojibiose phosphorylase. These oligosaccharides were isolated using carbon-Celite column chromatography and preparative high performance liquid chromatography. Gas liquid chromatography analysis of methyl derivatives, MALDI-TOF MS and NMR measurements were used for structural characterisation. The ¹H and ¹³C NMR signals of each saccharide were assigned using 2D-NMR including COSY (correlated spectroscopy), HSQC (herteronuclear single quantum coherence), CH₂-selected E-HSQC (CH₂-selected Editing-HSQC), HSQC-TOCSY (HSQC-total correlation spectroscopy) and HMBC (heteronuclear multiple bond correlation).</p> <p>Conclusion</p> <p>The structure of three synthesized saccharides were determined, and these oligosaccharides have been identified as <it>O</it>-α-D-glucopyranosyl-(1→2)-<it>O</it>-α-D-xylopyranosyl-(1→2)-β-D-fructofuranoside (saccharide <b>1</b>), <it>O</it>-α-D-glucopyranosyl-(1→2)-<it>O</it>-α-D-glucopyranosyl-(1→2)-<it>O</it>-α-D-xylopyranosyl-(1→2)-β-D-fructofuranoside (saccharide <b>2</b>) and <it>O</it>-α-D-glucopyranosyl-(1→[2-<it>O</it>-α-D-glucopyranosyl-1]₂→2)-<it>O</it>-α-D-xylopyranosyl-(1→2)-β-D-fructofuranoside (saccharide <b>3</b>).</p

Prospective evaluation of core number of biopsy for renal tumor: are multiple cores preferable?

Purpose This single-center, single-arm, prospective, open-label study was conducted to evaluate the optimal number of cores (single or multiple) in renal tumor biopsy. Materials and methods Forty-four biopsies of 44 tumors (mean diameter, 2.7 ± 1.0 cm; range, 1.6–5.0 cm) were included. Biopsy was performed under ultrasound or computed tomography fluoroscopy guidance using an 18-gauge cutting needle and the co-axial method. Two or more specimens were obtained, which were divided into first and subsequent specimens. “First specimen” and “all specimens” were histologically evaluated (i.e., appropriateness of specimen, histological diagnosis, subtype, and Fuhrman grade of renal cell carcinoma [RCC]) blindly and independently by two board-certified pathologists. Results Multiple specimens were successfully and safely obtained in all the biopsies. All tumors were histologically diagnosed; 40 malignancies included 39 RCCs and 1 solitary fibrous tumor, and 4 benign lesions included 2 angiomyolipomas, 1 oncocytoma, and 1 capillary hemangioma. In all RCCs, the subtype could be determined (32 clear cell RCCs, 4 chromophobe RCCs, and 3 papillary RCCs), and the Furman grade was determined in 38 RCCs. When only the first specimen was evaluated, 22.7% of the specimens were inappropriate for diagnosis, and 34 (77.3%) were histologically diagnosed. The diagnostic yield was significantly lower than that of all specimens (P = 0.0044). Univariate analysis revealed that smaller lesions were a significant predictor of diagnostic failure (P = 0.020). Conclusion Biopsy with multiple cores significantly improved diagnostic yield. Thus, operators should obtain multiple cores during renal tumor biopsy

Safe and efficient method for cryopreservation of human induced pluripotent stem cell-derived neural stem and progenitor cells by a programmed freezer with a magnetic field

AbstractStem cells represent a potential cellular resource in the development of regenerative medicine approaches to the treatment of pathologies in which specific cells are degenerated or damaged by genetic abnormality, disease, or injury. Securing sufficient supplies of cells suited to the demands of cell transplantation, however, remains challenging, and the establishment of safe and efficient cell banking procedures is an important goal. Cryopreservation allows the storage of stem cells for prolonged time periods while maintaining them in adequate condition for use in clinical settings. Conventional cryopreservation systems include slow-freezing and vitrification both have advantages and disadvantages in terms of cell viability and/or scalability. In the present study, we developed an advanced slow-freezing technique using a programmed freezer with a magnetic field called Cells Alive System (CAS) and examined its effectiveness on human induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs). This system significantly increased cell viability after thawing and had less impact on cellular proliferation and differentiation. We further found that frozen-thawed hiPSC-NS/PCs were comparable with non-frozen ones at the transcriptome level. Given these findings, we suggest that the CAS is useful for hiPSC-NS/PCs banking for clinical uses involving neural disorders and may open new avenues for future regenerative medicine

Krüppel-like is required for nonskeletogenic mesoderm specification in the sea urchin embryo

金沢大学大学院自然科学研究科遺伝情報学The canonical Wnt pathway plays a central role in specifying vegetal cell fate in sea urchin embryos. SpKrl has been cloned as a direct target of nuclear β-catenin. Using Hemicentrotus pulcherrimus embryos, here we show that HpKrl controls the specification of secondary mesenchyme cells (SMCs) through both cell-autonomous and non-autonomous means. Like SpKrl, HpKrl was activated in both micromere and macromere progenies. To examine the functions of HpKrl in each blastomere, we constructed chimeric embryos composed of blastomeres from control and morpholino-mediated HpKrl-knockdown embryos and analyzed the phenotypes of the chimeras. Micromere-swapping experiments showed that HpKrl is not involved in micromere specification, while micromere-deprivation assays indicated that macromeres require HpKrl for cell-autonomous specification. Transplantation of normal micromeres into a micromere-less host with morpholino revealed that macromeres are able to receive at least some micromere signals regardless of HpKrl function. From these observations, we propose that two distinct pathways of endomesoderm formation exist in macromeres, a Krl-dependent pathway and a Krl-independent pathway. The Krl-independent pathway may correspond to the Delta/Notch signaling pathway via GataE and Gcm. We suggest that Krl may be a downstream component of nuclear β-catenin required by macromeres for formation of more vegetal tissues, not as a member of the Delta/Notch pathway, but as a parallel effector of the signaling (Krl-dependent pathway). © 2007 Elsevier Inc. All rights reserved