Effect of C-peptide Alone or in Combination with Nicotinamide on Insulin Levels from Pancreatic Islets in Mouse

Background: Both c-peptide and nicotinamide are known to increase blood insulin in diabetes. In the present study, we examined the effect of c-peptide alone or in combination with nicotinamide on insulin levels in pancreatic islets in mice. Methods: This study was conducted with 60 adult male Naval Medical Research Institute (NMARI) mice weighing 25 to 30 g. Pancreatic islets from normal mice were isolated by the collagenase digestion method. Mice were divided into ten groups of six (n = 6): control, glyburide (1 and 10 μM), C-peptide (50 and 100 nM), nicotinamide (10, 25, and 100 mM), nicotinamide + C-peptide (100 mM and 100 nM), and buffer in different glucose concentrations (2.8, 5.6, and 16.7 mM). Insulin secretion was measured using insulin radioimmunoassay method. Results: Insulin secretion significantly increased at 16.7 mM glucose concentration compared with 2.8 and 5.6 mM glucose concentrations. Incubation of islets at 2.8 and 5.6 mM glucose concentrations and nicotinamide + C-peptide, nicotinamide 25 and 100 mM, and C-peptide 100 nM significantly increased insulin secretion compared with the control group. In addition, incubation of islets at 16.7 mM glucose with nicotinamide + C-peptide significantly increased insulin secretion. Glyburide at 10 μM concentration was more effective than nicotinamide at 10 and 100 mM, C-peptide 50 and 100 nM in the presence of 16.7 mM glucose concentration. However, the combination of nicotinamide + C-peptide was more effective than glyburide at a concentration of 10 μM in the presence of a 16.7 mM glucose concentration. Conclusions: This paper suggests that c-peptide, nicotinamide, and the combination of c-peptide and nicotinamide in-creases insulin secretion from pancreatic islets.

Effect of C-peptide Alone or in Combination with Nicotinamide on Glucose and Insulin Levels in Streptozotocin–Nicotinamide-Induced Type 2 Diabetic Mice

Background: Both C-peptide and nicotinamide are known to reduce blood glucose in type 1 diabetes. In the present study, the effects of C-peptide alone or in combination with nicotinamide on glucose and insulin levels in streptozotocin-nicotinamide-induced type 2 diabetic mice. Methods: The study used 70 adult male NMARI mice, weighing 25–35 g, divided into seven groups: control; type 1 diabetic; type 2 diabetic; type 2 diabetic + C-peptide; type 2 diabetic + nicotinamide; type 2 diabetic + nicotinamide and C-peptide; type 2 diabetic + glyburide. Type 2 diabetes was induced with ip injection of streptozotocin–nicotinamide. Twenty eight days after the onset of diabetes, treatment with C-peptide, nicotinamide, nicotinamide + C-peptide, or glyburide were initiated. Glucose and insulin levels were evaluated. One-way ANOVA and Least Significant Difference (LSD) tests were used to test for significance. Results: Blood glucose significantly increased (P < 0.001) in all diabetic mice compared with control mice. Insulin resistance and blood glucose levels were significantly reduced (P < 0.05) in C-peptide and nicotinamide + C-peptide mice compared with type 2 diabetic mice. Conclusions: The present study supports the anti-diabetic effects of C-peptide, nicotinamide + C-peptide, and suggests that one of the anti-diabetic mechanisms of these compounds is mediated through the reduction of insulin resistance.

[Evaluation of nutritional quality and microbial contamination of enteral feeding solutions in hospitalized patients referred to neurosurgical ICU of Poursina hospital in Rasht]

The aim of this study was to evaluate enteral feeding solutions used in trauma patients in terms of their nutritional quality and microbial contamination. Enteral feeding solutions prepared in the hospital were collected during 3 months. Microbial counts of solutions and macronutrient contents were evaluated and compared with food tables. One sample t test was used for comparing data with the predicted values. Energy and protein contents of 27 enteral feeding solutions prepared in different days were in range of 26.04-87.25 kcal and 1.33-8.44 g/100 ml, respectively; their mean values were 59.23 +/- 2.5 and 4.46 +/- 0.3 respectively. There was a significant difference between laboratory results and predicted values based on food tables. Coloni count of aerobic and coliform, 4 h after preparation of 22 solutions, were reported to be 2x10[6] +/- 2.9x10[5] and 8.9x10[5] +/- 6.8x10[5] CFU / g respectively and were much higher than PFA permitted value. The results showed that the real energy of solutions was less than the predicted values, so the energy intake of the patients is affected. In addition, these solutions had higher bacterial contamination than the allowed amount

Causes of blindness and severe visual impairment in children in schools for the blind in east azerbaijan state

To determine the anatomical site and underlying causes of blindness and severe visual impairment [BL/SVI], in schools for the blind in East Azerbaijan state with determining potentially preventable and treatable causes. Between October 2003 and November 2004 a total of 124 students attending three schools for the blind in East Azerbaijan state were examined clinically and data reported using the WHO/PEL childhood blindness assessment form. Most of the students [91.9%] were blind. The major causes of BL/SVI in our study were: Retinal dystrophy [mainly early onset retinitis pigmentosa] in 34.7% of participents; cataract and aphakia in 14.5%; corneal scar/haze in 15.4% and microphthalmus in 13.7%. The retina was the major anatomical site of visual loss [41.1%] followed by the whole globe [23.4%], lens [14.5%], cornea [15.3%] and optic nerve [5.6%]. A relatively high proportion of childhood blindness in East Azerbaijan state has avoidable causes. Most cases of corneal scars and phthisis can be prevented, and cataract is potentially treatable condition