Diabetes in 2007 - What are the promises & challenges?

No Abstrac

Orally active insulin mimics: where do we stand now?

The war against diabetes through the development of new drugs is an ongoing continuous process to counter the alarming global increase in the prevalence of diabetes and its complications, particularly in developing countries like India. Unfortunately, the speed with which our knowledge of diabetes and its effects is expanding is not matched by the availability of new drugs. Following the identification of the insulin receptor (IR), its intrinsic kinase activity and molecular cloning, many studies have looked at IR as an ideal drug target. This review summarizes in brief the latest advancements in this field with particular reference to the current situation in respect of the development of orally active insulin mimetics in the treatment of type 2 diabetes

Telomere shortening: a marker of atherosclerosis?

This article does not have an abstract

Evaporating Spray in Supersonic Streams Including Turbulence Effects

Evaporating spray plays an important role in spray combustion processes. This paper describes the development of a new finite-conductivity evaporation model, based on the two-temperature film theory, for two-phase numerical simulation using Eulerian-Lagrangian method. The model is a natural extension of the T-blob/T-TAB atomization/spray model which supplies the turbulence characteristics for estimating effective thermal diffusivity within the droplet phase. Both one-way and two-way coupled calculations were performed to investigate the performance of this model. Validation results indicate the superiority of the finite-conductivity model in low speed parallel flow evaporating sprays. High speed cross flow spray results indicate the effectiveness of the T-blob/T-TAB model and point to the needed improvements in high speed evaporating spray modeling

Investigation of Compressibility Effect for Aeropropulsive Shear Flows

Rocket Based Combined Cycle (RBCC) engines operate within a wide range of Mach numbers and altitudes. Fundamental fluid dynamic mechanisms involve complex choking, mass entrainment, stream mixing and wall interactions. The Propulsion Research Center at the University of Alabama in Huntsville is involved in an on- going experimental and numerical modeling study of non-axisymmetric ejector-based combined cycle propulsion systems. This paper attempts to address the modeling issues related to mixing, shear layer/wall interaction in a supersonic Strutjet/ejector flow field. Reynolds Averaged Navier-Stokes (RANS) solutions incorporating turbulence models are sought and compared to experimental measurements to characterize detailed flow dynamics. The effect of compressibility on fluids mixing and wall interactions were investigated using an existing CFD methodology. The compressibility correction to conventional incompressible two- equation models is found to be necessary for the supersonic mixing aspect of the ejector flows based on 2-D simulation results. 3-D strut-base flows involving flow separations were also investigated

Genomics and Proteomics of Type 2 Diabetes in Indians

No Abstrac

Differential gene expression of NADPH oxidase (p22phox) and hemoxygenase-1 in patients with Type 2 diabetes and microangiopathy

Aims: While the downstream effects of increased reactive oxygen species (ROS) in the pathogenesis of diabetes were well studied, only a few studies have explored the cellular sources of ROS. We examined whether protection against oxidative stress is altered in patients with diabetes and microangiopathy by examining changes in NADPH oxidase (p22phox) and hemoxygenase‐1 (HO‐1) levels. Methods: NADPH oxidase (p22phox) and HO‐1 gene expression were probed by RT‐PCR using leucocytes from patients with Type 2 diabetes without (n = 19) and with microangiopathy (n = 20) and non‐diabetic subjects (n = 17). Levels of lipid peroxidation as measured by thiobarbituric reactive substances (TBARS) and protein carbonyl content (PCO) were determined by fluorimetric and spectrophotometric methods, respectively. Results: p22phox gene expression (mean ± se) was significantly (P < 0.05) higher in diabetic patients with (0.99 ± 0.04) and without microangiopathy (0.86 ± 0.05) compared with control subjects (0.66 ± 0.05). Consistent with the mRNA data, the p22phox protein expression and NADPH oxidase activity was also increased in cells from diabetic patients compared with control subjects. However, HO‐1 gene expression was significantly (P < 0.05) lower in patients with (0.73 ± 0.03) and without microangiopathy (0.85 ± 0.02) compared with control subjects (1.06 ± 0.03). The mean (± se) levels of TBARS were significantly (P < 0.05) higher in diabetic patients with (14.36 ± 1.3 nm/ml) and without microangiopathy (12.20 ± 1.3 nm/ml) compared with control subjects (8.58 ± 0.7 nm/ml). The protein carbonyl content was also significantly (P < 0.05) higher in diabetic patients with (1.02 ± 0.04 nmol/mg protein) and without microangiopathy (0.84 ± 0.06 nmol/mg protein) compared with control subjects (0.48 ± 0.02 nmol/mg protein). In diabetic subjects, increased p22phox gene expression was negatively correlated with HO‐1 and positively correlated with TBARS, PCO, HbA1c and diabetes duration. In contrast, HO‐1 gene expression was correlated negatively with p22phox, TBARS, PCO, HbA1c and diabetes duration. Conclusion: Our results indicate that increased oxidative damage is seen in Asian Indians with Type 2 diabetes and microangiopathy and is associated with increased NADPH oxidase (p22phox) and decreased HO‐1 gene expression

Oxidative DNA damage and augmentation of poly(ADP-ribose) polymerase/nuclear factor-kappa B signaling in patients with Type 2 diabetes and microangiopathy

Although oxidative stress and the subsequent DNA damage is one of the obligatory signals for poly(ADP-ribose) polymerase (PARP) activation and nuclear factor-kappa B (NFκB) alterations, these molecular aspects have not been collectively examined in epidemiological and clinical settings. Therefore, this study attempts to assess the oxidative DNA damage and its downstream effector signals in peripheral blood lymphocytes from Type 2 diabetes subjects without and with microangiopathy along with age-matched non-diabetic subjects. The basal DNA damage, lipid peroxidation and protein carbonyl content were significantly (p < 0.05) higher in patients with and without microangiopathy compared to control subjects. Formamido Pyrimidine Glycosylase (FPG)-sensitive DNA strand breaks which represents reliable indicator of oxidative DNA damage were also significantly (p < 0.001) higher in diabetic patients with (19.41 ± 2.5) and without microangiopathy (16.53 ± 2.0) compared to control subjects (1.38 ± 0.85). Oxidative DNA damage was significantly correlated to poor glycemic control. PARP mRNA expression and PARP activity were significantly (p < 0.05) increased in cells from diabetic patients with (0.31 ± 0.03 densitometry units; 0.22 ± 0.02 PARP units/mg protein, respectively) and without (0.35 ± 0.02; 0.42 ± 0.05) microangiopathy compared to control (0.19 ± 0.02; 0.11 ± 0.02) subjects. Diabetic subjects with and without microangiopathy exhibited a significantly (p < 0.05) higher (80%) NFκB binding activity compared to control subjects. In diabetic patients, FPG-sensitive DNA strand breaks correlated positively with PARP gene expression, PARP activity and NFκB binding activity. This study provides a comprehensive molecular evidence for increased oxidative stress and genomic instability in Type 2 diabetic subjects even prior to vascular pathology and hence reveals a window of opportunity for early therapeutic intervention