Coronary heart disease (CHD) remains the leading cause of death in DM2. The purpose of this study is to determine the usefulness and effectiveness of exercise electrocardiography (Ex-ECG) and standard two-dimensional echocardiography (2DE) among type 2 diabetic (DM2) and nondiabetic (NDM) of both genders in the diagnosis of CHD accompanied with biochemical risk factors for CHD A total of 102 age-matched DM2 and non-diabetic individuals in both genders were recruited in the current study. All cases were assessed for CHD diagnosis using the guidelines of the Bengali version of the Rose Angina Questionnaire. All groups were examined clinically by cardiologists and applying Ex-ECG and 2DE accompanied by biochemical parameters analysis of all participants in Ematiga's laboratory. All diabetic and non-diabetic subjects are age-matched. The diabetic women were obese with a BMI of (>30 kg/m2 ). The duration of diabetes in females was (10.2±1.02 yrs) and in males was (9.7±0.8 yrs). There was a positive relationship between the duration of diabetes and HbA1c level. Some evidence presented in this study revealed that the percentage of LVEF is negatively correlated with the duration of diabetes mellitus. In addition, there is statistical significance in ST-depression between both genders in (ND) and (D) groups. The relationship between STdepression expressed as mV detected by Ex-ECG and duration of diabetes in females and males. In conclusion, both Ex-ECG, and 2DE testing are non-invasive, easy to perform, and accessible in rural hospitals and clinics. It can be beneficial in diagnosing, risk stratifying or assessing patients with CHD provided appropriate patient selection is used to enhance its sensitivity and specificity, especially in presence of biochemical risk factors for coronary heart disease explained in this study helped identify or exclude the early diagnosis of CHD.

ABSTRACT Coronary artery disease (CAD) is quite common among diabetics in all age groups and its risk is independently affiliated with Lipoprotein-associated phospholipase A2 (LP-PLA2). There is strong evidence that the elevated plasma level of Lp-PLA2 indicates vascular inflammation associated with plaque formation within the arteries. Therefore, the relationship between the plasma Lp-PLA2 level and coronary

artery disease risk factors between non-diabetic and diabetic patients will be studied. Materials and Methods: A total of 181 individuals were recruited from the National Heart Centre Tajoura and divided into 4 groups (40 healthy controls (HC), 43 non-diabetics (NDM) who had CAD, 54 DM2 without CAD, and 44 DM2 who had CAD). The relationship between Lp-PLA2 and the potential biochemical risk markers for CAD will be studied between the groups. Results: All the groups that participated in this study have similar body mass index. There is statistical significance in the level of plasma level Lp-PLA2 between DM2 with CAD, DM2 without CAD and HC with ( ***P<0.0001, **P<0.006), respectively; and likewise between NDM with CAD and HC with *P<0.05. Although there is a significant difference between the plasma levels of Lp-PLA2 between the groups below the age of 60 years, there is no statistical significance between the groups above the age of 60 years. Correspondingly, there is a statistical difference in the plasma level of Lp-PLA2 between healthy controls and both DM2 without CAD and DM2 with CAD with (**P<0.006, and ***P<0.0001), respectively. Once more, there is statistical significance in the plasma level of Lp-PLA2 between NDM with CAD and healthy controls with *P<0.05. Furthermore, there is a statistical difference in the serum level of CRP between DM2 with CAD and HC. In addition, there is a positive relationship exists between the duration of diabetes mellitus without CAD and the level of glycated haemoglobin (HbA1c) with **P <0.003 in both genders. Conclusion: In this study, the high level of Lp-PLA2 and CRP strongly indicate the presence of vascular inflammation associated with the formation of arterial atherosclerosis with thrombus formation. These findings are also correlated with diabetic duration and they could be used in the diagnosis and prognosis of coronary artery disease. 

Diabetic retinopathy is one of the most common diabetic complications, and is a major cause of new blindness in the working-age population of developed countries. Progression of vascular abnormalities, including the selective loss of pericytes, formation of acellular capillaries, thickening of the basement membrane, and increased vascular permeability characterizes early nonproliferative diabetic retinopathy (NPDR). Capillary occlusion, as shown on fluorescein angiograms, is also one of the earliest clinically recognizable lesion of NPDR. In response to capillary non-perfusion, there is dilation of neighbouring capillaries, leading to early blood-retinal barrier breakdown, capillary non-perfusion, and endothelial cell injury and death. The resulting ischemia leads to increased production of growth factors, and the development of proliferative diabetic retinopathy (PDR), which is characterized by growth of new vessels and potential severe and irreversible visual loss. The exact pathogenic mechanism by which capillary non-perfusion occurs is still unclear but growing evidence now suggests that increased leukocyte-endothelial cell adhesion and entrapment (retinal leukostasis) in retinal capillaries is an early event associated with areas of vascular non-perfusion and the development of diabetic retinopathy. The leukocytes in diabetic patients are less deformable more activated, and demonstrate increased adhesion to the vascular endothelium. This review summarizes the current literature on the role of leukocytes in the pathogenesis of capillary occlusion, and discusses the potential of leukostasis as a new promising target in the treatment of diabetic retinopathy.

Aims/hypothesis: Increasing evidence suggests that chronic, subclinical inflammation plays an important role in the pathogenesis of diabetic retinopathy. We recently reported that a glycosylating enzyme, core 2 beta-1,6-N-acetylglucosaminyltransferase (core 2 GlcNAc-T), is implicated in increased leucocyte-endothelial cell adhesion in diabetic retinopathy via an upregulation mechanism controlled by TNF-alpha.

Subjects, materials and methods: We examined the functional link between circulating TNF-alpha and the activity and phosphorylation of core 2 GlcNAc-T in polymorphonuclear leucocytes of patients with type 1 and type 2 diabetes.

Results: Plasma levels of TNF-alpha, although similar in patients with type 1 and type 2 diabetes, were significantly higher than in age-matched healthy controls, and correlated well with the severity of retinopathy. Core 2 GlcNAc-T activity followed the same trend and was associated with phosphorylation of the enzyme. Finally, the observation that TNF-alpha levels are also linked to glycaemic values suggests that in patients, as well as in vitro, the glycosylation-mediated cell adhesion process that plays a role in diabetic retinopathy may involve glucose- and TNF-alpha-induced protein kinase beta2 activation, and subsequently raise activity of core 2 GlcNAc-T through increased enzyme phosphorylation.

Conclusions/interpretation: Our results reveal a novel rationale towards a specific treatment of diabetic retinopathy, based on the inhibition of core 2 GlcNAc-T activity and/or the blockage of cognate glycans.

A large body of evidence now implicates increased leukocyte-endothelial cell adhesion as a key early event in the development of diabetic retinopathy. We recently reported that raised activity of the glycosylating enzyme core 2 beta 1,6-N-acetylglucosaminyltransferase (GlcNAc-T) through protein kinase C (PKC)beta2-dependent phosphorylation plays a fundamental role in increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy. In the present study, we demonstrate that following exposure to plasma from diabetic patients, the human promonocytic cell line U937 exhibits a significant elevation in core 2 GlcNAc-T activity and increased adherence to cultured retinal capillary endothelial cells. These effects of diabetic plasma on enzyme activity and cell adhesion, mediated by PKCbeta2-dependent phosphorylation of the core 2 GlcNAc-T protein, were found to be triggered by increased plasma levels of tumor necrosis factor (TNF)-alpha. Levels of enzyme activity in plasma-treated U937 cells were closely dependent on the severity of diabetic retinopathy, with the highest values observed upon treatment with plasma of patients affected by proliferative retinopathy. Furthermore, we noted much higher correlation, as compared with control subjects, between increased values of core 2 GlcNAc-T activity and cell adhesion properties. Based on the prominent role of TNF-alpha in the development of diabetic retinopathy, these observations further validate the significance of core 2 GlcNAc-T in the pathogenesis of capillary occlusion, thereby enhancing the therapeutic potential of specific enzyme inhibitors.

Increased leukocyte-endothelial cell adhesion is a key early event in the development of retinopathy and atherogenesis in diabetic patients. We recently reported that raised activity of glycosylating enzyme [beta]1,6 acetylglucosaminyltransferase (core 2 GlcNAc-T) is responsible for increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy. Here, we demonstrate that elevated glucose increases the activity of core 2 GlcNAc-T and adhesion of human leukocytes to retinal capillary endothelial cells, in a dose-dependent manner, through diabetes-activated serine/threonine protein kinase C beta2 (PKCbeta2)-dependent phosphorylation. This regulatory mechanism, involving phosphorylation of core 2 GlcNAc-T, is also present in polymorphonuclear leukocytes isolated from type 1 and type 2 diabetic patients. Inhibition of PKCbeta2 activation with the specific inhibitor, LY379196, attenuated serine phosphorylation of core 2 GlcNAc-T and prevented increased leukocyte-endothelial cell adhesion. Raised activity of core 2 GlcNAc-T was associated with a threefold increase in O-linked glycosylation of P-selectin glycoprotein ligand-1 on the surface of leukocytes of diabetic patients compared with age-matched control subjects. PKCbeta2-dependent phosphorylation of core 2 GlcNAc-T may thus represent a novel regulatory mechanism for activation of this key enzyme in mediating increased leukocyte-endothelial cell adhesion and capillary occlusion in diabetic retinopathy.

The exact mechanism for capillary occlusion in diabetic retinopathy is still unclear, but increased leukocyte-endothelial cell adhesion has been implicated. We examined the possibility that posttranslational modification of surface O-glycans by increased activity of core 2 transferase (UDP-Glc:Galbeta1-3GalNAcalphaRbeta-N-acetylglucoaminyltr ansferase) is responsible for increased adhesion of leukocytes to vascular endothelium in diabetes. The mean activity of core 2 transferase in polymorphonuclear leukocytes isolated from type 1 and type 2 diabetic patients was higher compared with age-matched control subjects (1,638 +/- 91 [n = 42] vs. 249 +/- 35 pmol x h(-1) x mg(-1) protein [n = 24], P = 0.00013; 1,459 +/- 194 [n = 58] vs. 334 +/- 86 [n = 11], P = 0.01). As a group, diabetic patients with retinopathy had significantly higher mean activity of core 2 transferase compared with individuals with no retinopathy. There was a significant association between enzyme activity and severity of retinopathy in type 1 and type 2 diabetic patients. There was a strong correlation between activity of core 2 transferase and extent of leukocyte adhesion to cultured retinal capillary endothelial cells for diabetic patients but not for age-matched control subjects. Results from transfection experiments using human myelocytic cell line (U937) demonstrated a direct relationship between increased activity of core 2 transferase and increased binding to cultured endothelial cells. There was no relationship between activity of core 2 transferase and HbA(1c) (P = 0.8314), serum advanced glycation end product levels (P = 0.4159), age of the patient (P = 0.7896), and duration of diabetes (P = 0.3307). On the basis that branched O-glycans formed by the action of core 2 transferase participate in leukocyte adhesion, the present data suggest the involvement of this enzyme in increased leukocyte-endothelial cell adhesion and the pathogenesis of capillary occlusion in diabetic retinopathy.