Metformin use and cardiovascular outcomes after acute myocardial infarction in patients with type 2 diabetes: a cohort study

Background: The use of metformin after acute myocardial infarction (AMI) has been associated with reduced mortality in people with type 2 diabetes mellitus (T2DM). However, it is not known if it is acutely cardioprotective in patients taking metformin at the time of AMI. We compared patient outcomes according to metformin status at the time of admission for fatal and non-fatal AMI in a large cohort of patients in England. Methods: This study used linked data from primary care, hospital admissions and death registry from 4.7 million inhabitants in England, as part of the CALIBER resource. The primary endpoint was a composite of acute myocardial infarction requiring hospitalisation, stroke and cardiovascular death. The secondary endpoints were heart failure (HF) hospitalisation and all-cause mortality. Results: 4,030 patients with T2DM and incident AMI recorded between January 1998 and October 2010 were included. At AMI admission, 63.9% of patients were receiving metformin and 36.1% another oral hypoglycaemic drug. Median follow-up was 343 (IQR: 1–1436) days. Adjusted analyses showed an increased hazard of the composite endpoint in metformin users compared to non-users (HR 1.09 [1.01–1.19]), but not of the secondary endpoints. The higher risk of the composite endpoint in metformin users was only observed in people taking metformin at AMI admission, whereas metformin use post-AMI was associated with a reduction in risk of all-cause mortality (0.76 [0.62–0.93], P = 0.009). Conclusions: Our study suggests that metformin use at the time of first AMI is associated with increased risk of cardiovascular disease and death in patients with T2DM, while its use post-AMI might be beneficial. Further investigation in well-designed randomised controlled trials is indicated, especially in view of emerging evidence of cardioprotection from sodium-glucose co-transporter-2 (SGLT2) inhibitors

Detection of embryonic stem cell markers in adult human adipose tissue-derived stem cells

Background: Bone marrow transplantation is already an established therapy, which is now widely used in medicine to treat leukemia, lymphoma, and several inherited blood disorders. The culture of multilineage cells from easily available adipose tissue is another source of multipotent mesenchymal stem cells, and is referred to as adipose tissue-derived stem cells (ADSCs). While ADSCs are being used to treat various conditions, some lacuna exists regarding the specific proteins in these. It was therefore decided to analyze the specific proteins of embryonic cells in ADSCs. Aims: To analyze the specific protein of embryonic stem cells (ESCs) in ADSCs. Materials and Methods: Adult human adipose tissue-derived stem cells (ADSCs) were harvested from 13 patients after obtaining patients′ consent. The specific markers of ESCs included surface proteins CD10, CD13, CD44, CD59, CD105, and CD166, and further nucleostemin,(NS) NANOG, peroxisome proliferator-activated receptor-gγ, collagen type 1 (Coll1), alkaline phosphate, (ALP) osteocalcin (OC), and core binding factor 1 (Cbfa1) were analyzed using by reverse transcription-polymerase chain reaction, (RT-PCR) immunofluorescence (IF), and western blot. Results: All the proteins were expressed distinctly, except CD13 and OC. CD13 was found individually with different expressions, and OC expression was discernable. Conclusions: Although the ESC with its proven self-renewal capacity and pluripotency seems appropriate for clinical use, the recent work on ADSCs suggests that these adult stem cells would be a valuable source for future biotechnology, especially since there is a relative ease of procurement

The Proneural Proteins Atonal and Scute Regulate Neural Target Genes through Different E-Box Binding Sites

For a particular functional family of basic helix-loop-helix (bHLH) transcription factors, there is ample evidence that different factors regulate different target genes but little idea of how these different target genes are distinguished. We investigated the contribution of DNA binding site differences to the specificities of two functionally related proneural bHLH transcription factors required for the genesis of Drosophila sense organ precursors (Atonal and Scute). We show that the proneural target gene, Bearded, is regulated by both Scute and Atonal via distinct E-box consensus binding sites. By comparing with other Ato-dependent enhancer sequences, we define an Ato-specific binding consensus that differs from the previously defined Scute-specific E-box consensus, thereby defining distinct E(Ato) and E(Sc) sites. These E-box variants are crucial for function. First, tandem repeats of 20-bp sequences containing E(Ato) and E(Sc) sites are sufficient to confer Atonal- and Scute-specific expression patterns, respectively, on a reporter gene in vivo. Second, interchanging E(Ato) and E(Sc) sites within enhancers almost abolishes enhancer activity. While the latter finding shows that enhancer context is also important in defining how proneural proteins interact with these sites, it is clear that differential utilization of DNA binding sites underlies proneural protein specificity