Treatment with diazoxide causes prolonged improvement of β-cell function in rat islets transplanted to a diabetic environment
摘要:
Prolonged hyperglycemia desensitizes beta cells. A role for hyperglycemia-induced excessive stimulation can be tested by diazoxide, which inhibits glucose-induced insulin secretion. Using diazoxide, we have investigated in a rat transplantation model whether excessive stimulation can induce lasting effects on beta cells. One batch with 150 islets and another with 20 islets isolated from Wistar-Furth rats were transplanted under the left-kidney capsule of syngeneic streptozotocin-diabetic recipients. In a first series, recipients were treated for 8 weeks with or without 0.2% diazoxide in the food. Graft-bearing kidneys were then perfused and excised. Diazoxide treatment increased by 5.5;fold the insulin response to 10 mmol/L arginine, by 4.1-fold the graft insulin content, and by 2.3-fold the preproinsulin mRNA versus nontreated diabetic controls. The persistence of these effects was assessed in a second series in which 8 weeks of diazoxide treatment was followed by 1 week of no treatment. Again, perfusion experiments showed a higher insulin response to arginine in diazoxide-treated rats (136.0 +/- 25.7 v 62.3 +/- 11.8 fmol/min, P < .05). Also, the response to 27.8 mmol/L glucose was increased (54.0 +/- 17.1 v 13.6 +/- 7.8 fmol/min, P < .05). The insulin content was increased (2.2 +/- 0.6 v 1.0 +/- 0.4 pmol/islet, P < .05), as well as the preproinsulin mRNA (0.60 +/- 0.08 v 0.22 +/- 0.02 pg/islet, P < .05). In a third series, we tested the impact of diazoxide treatment when given only during the first 2 weeks following transplantation. When tested 6 weeks later, insulin secretion was unaffected, whereas there was a strong tendency for a higher preproinsulin mRNA and insulin content in grafts of diazoxide;treated rats. In conclusion, this study demonstrates that beta-cell function in transplanted islets is improved by diazoxide long after the end of treatment, an effect that is likely due to removal of hyperglycemia induced excessive stimulation. Copyright (C) 2000 by W.B. Saunders Company.
peculiar profile of pentadecylidenemalonate 1b, the first activator/inhibitor of histoneacetyltransferases. Together with the powerful apoptotic effect (particularly notable if considering that anacardic acid and other KAT inhibitors are not cell permeable) appoint them as valuable biological tools to understand the mechanisms of lysineacetyltransferases.
A series of novel malonic acid diamides (second generation) with two long hydrophobic alkyl chains and an alkaline polar head group was synthesised and characterised as a new class of amino‐functionalised lipids. These peptide‐mimic lipids are suitable for polynucleotide transfer. The lipids bear a novel backbone consisting of a lysine unit and a malonic acid unit. Six different head‐group structures
Bithiophenesulfonamide Building Block for π-Conjugated Donor–Acceptor Semiconductors
作者:Ferdinand S. Melkonyan、Wei Zhao、Martin Drees、Nicholas D. Eastham、Matthew J. Leonardi、Melanie R. Butler、Zhihua Chen、Xinge Yu、Robert P. H. Chang、Mark A. Ratner、Antonio F. Facchetti、Tobin J. Marks
DOI:10.1021/jacs.6b03498
日期:2016.6.8
We report here π-conjugated small molecules and polymers based on the new π-acceptor building block, bithiophenesulfonamide (BTSA). Molecular orbital computations and optical, electrochemical, and crystal structure analyses illuminate the architecture and electronic structure of the BTSA unit versus other acceptor building blocks. Field-effecttransistors and photovoltaic cells demonstrate that BTSA
Bithiophene sulfonamide-based molecular and polymeric semiconductors
申请人:Polyera Corporation
公开号:US09666805B2
公开(公告)日:2017-05-30
The present invention relates to new semiconducting compounds having at least one optionally substituted bithiophene sulfonamide moiety. The compounds disclosed herein can exhibit high carrier mobility and/or efficient light absorption/emission characteristics, and can possess certain processing advantages such as solution-processability and/or good stability at ambient conditions.
NOVEL XYLENE-BASED AMPHIPHILIC COMPOUND AND USE THEREOF
申请人:Industry-University Cooperation Foundation Hanyang University Erica Campus
公开号:US20180273570A1
公开(公告)日:2018-09-27
The present invention relates to a xylene-based amphiphilic compound, a method for preparing the same, and a method for extracting, solubilizing, stabilizing or crystallizing a membrane protein using the same. By using the xylene-based compound according to the present invention, a membrane protein may be stably stored in an aqueous solution for a long time, and may be applied in functional and structural analyses. The structural and functional analysis of the membrane protein is one of the fields of highest interest in biology and chemistry, and the xylene-based compound according to the present invention can be applied in research on protein structure that is closely related to development of a new drug.