Imbalance of angiogenesis in diabetic complications: the mechanisms

Type 2 diabetes mellitus is a complex disease and a chronic health-care problem. Nowadays, because of alteration of lifestyle such as lack of exercise, intake of high fat diet subsequently obesity and aging population, the prevalence of diabetes mellitus is increasing quickly in around the world. The international diabetes federation estimated in 2008, that 246 million adults in worldwide suffered from diabetes mellitus and the prevalence of disease is expected to reach to 380 million by 2025. Although, mainly in management of diabetes focused on hyperglycemia, however, it is documented that abnormalities of angiogenesis may contribute in the pathogenesis of diabetes complications. Angiogenesis is the generation of new blood vessels from pre-existing ones. Normal angiogenesis depends on the intricate balance between angiogenic factors [such as VEGF, FGF[2], TGF-[registered sign], angiopoietins] and angiostatic factors [angiostatin, endostatin, thrombospondins]. Vascular abnormalities in different tissues including retina and kidney can play a role in pathogenesis of micro-vascular complications of diabetes; also vascular impairment contributes in macrovascular complications e.g., diabetic neuropathy and impaired formation of coronary collaterals. Therefore, identifying of different mechanisms of the diabetic complications can give us an opportunity to prevent and/or treat the following complications and improves quality of life for patients and society. In this review, we studied the mechanisms of angiogenesis in micro-vascular and macro-vascular complications of diabetes mellitus

Protective role of selective nitric oxide synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats

Different vasoactive factors can modulate cardiovascular adaptation to hemorrhagic shock including Nitric Oxide [NO]. In this study we investigated the effect of the NO synthase inhibitor for treatment of decompensated hemorrhagic shock in normotensive and hypertensive rats. Twenty four male Wistar rats were divided into two groups: The normotensive and hypertensive groups. Hypertension was induced by the DOCA Salt method for eight weeks. Then, the animals were given hemorrhagic shock by continuously withdrawing blood until the mean arterial pressure [MAP] reached to 40 mmHg. The animals were maintained in the shock state for 120 minutes. Subsequently, they were randomly assigned to L-NAME-treated and non treated groups and monitored for 60 minutes. The survival time was recorded. Blood samples were taken before and after the shock and 60 minutes after L NAME administration. Infusion of L-NAME caused a significant increase in MAP in normotensive animals, however, slightly increased MAP in hypertensive animals. The heart rate did not significantly alter. Hemorrhage caused a marked increase in serum nitrite levels in both groups [P<0.05]. L NAME treatment significantly reduced the serum nitrite concentration in the normotensive group [P<0.05], without any change in the hypertensive group. All animals who received L-NAME treatment survived at the end of experiment. Fifty percent of the hypertensive animals died four hours after the experiment. The 72 hour survival rate was similar in the L-NAME treated groups. L-NAME infusion during decompensated hemorrhagic shock plays a protective role in the improvement of hemodynamic responses and short term survival rate in normotensive animals

Comparison of the value of two different sputum staining for diagnosis of acid-fast bacilli

The aim of this study was to compare the diagnostic value of fluorochrome microscopy [FM] with Ziehl-Neelsen [ZN] staining in the diagnosis of tuberculosis [TB]. In this study, 920 consecutive patients suspected of having pulmonary TB, referred to TB laboratory, provincial office of health care, Birjand University of Medical Sciences, recruited and a total of 2760 sputum specimens were collected from them. All samples were smeared and stained using both Ziehl Neelsen and auraminphenol methods as recommended by WHO. All positive smears by fluorescent microscopy were over-stained by ZN technique for confirmation. The sensitivity of ZN staining was also evaluated in different contamination conditions. A total of 102 out of 920 study subjects had pulmonary TB, of them 68 [66.66%] patients were smear positive by either staining method while others were smear negative. The proportion of positive smears detected was 51% and 57% for the ZN and auramine phenol staining methods, respectively. The sensitivity, specificity, positive predictive value and negative predictive value were 51%, 100%, 100%, 94% and 57%,100%,100, 95% for the ZN and auramine phenol staining methods, respectively. FM is more sensitive than ZN for diagnosis of TB. However, since FM is more sensitive and rapid, using this method in clinical laboratories with large specimen numbers is recommended

effect of aspirin on serum vascular endothelial growth factor and nitric oxide concentration in high-cholesterol fed rabbits

Hypercholesterolemia is one of the major risk factors for atherosclerosis which is characterized by endothelial dysfunction. This study was designed to investigate the effect of aspirin on serum vascular endothelial growth factor [VEGF] and nitric oxide [NO] concentrations in hypercholesterolemic animals. Sixteen male rabbits were randomly divided into two groups, aspirin-treated and control. Aspirin [10 mg/kg/day] was administered orally using feeding tube. All animals were fed with high-cholesterol diet [1%] during the experiment. After five weeks, blood pressure, serum lipid and lipoprotein profiles, serum VEGF and NO concentrations were measured. Aspirin did not change blood pressure. Aspirin significantly decreased serum LDL [1276 +/- 72.1 vs. 1505 +/- 68.03 mg/dl] and triglyceride [477.5 +/- 8.3 vs. 649.1 +/- 15.2 mg/dl] [P<0.05]. High-cholesterol diet significantly decreased serum VEGF level in both groups [control: 24.59 +/- 0.42 vs. 38.09 +/- 2.49 pg/ml; aspirin: 24.72 +/- 0.84 vs. 42.29 +/- 2.03 pg/ml] [P<0.05] and aspirin did not change serum VEGF level in hypercholesterolemic animals [P>0.05]. Serum NO concentration was also significantly decreased after five weeks of high-cholesterol diet [control: 5.87 +/- 0.33 vs. 8.67 +/- 0.68 ?mol/lit; aspirin: 5.66 +/- 0.33 vs. 8.58 +/- 0.60 ?mol/lit] [P<0.05]. Aspirin did not change serum NO level [P>0.05]. We conclude that under the conditions of this study, aspirin cannot change serum VEGF and NO concentrations in high-cholesterol fed animals

Mathematical model for determination of colloid osmotic pressure: the role of albumin-globulin ratio

Colloid Osmotic Pressure [COP] is an important factor in the fluid balance of body compartments. COP is related to Total Protein [TP] concentration and Albumin: Globulin Ratio [A/G]. The A/G was not included in pervious empirical models, and therefore the main objective of this study was to develop a mathematical model to determine the COP in terms of TP concentration and A/G. Sera with different A/G were prepared in-vitro, and COP was measured directly using colloid osmometer. The relationship between COP, TP concentration and A/G were determined mathematically. The validity of developed empirical models was confirmed by statistical comparison between measured and calculated COP in 122 serum samples obtained from hospitalized patients and healthy individuals. By non-linear regression, the following relationships were found between COP, TP concentration and A/G. All coefficients were statistically significant [p<0.05]: COP = [4.0814 A/G TP]/[A/G + 0.0153 TP]; r[2] = 0. 91272. COP = [5.3192 A/G -2.2252 [A/G]2 + 0.2939 [A/G]3] TP; r[2] = 0.94737 No significant differences were indicated between measured COP and calculated one in clinical data. The variation of A/G may be the most effective factor for the differences between calculated and measured COP. This parameter must be considered when the direct measurement of COP is unavailable