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BACKGROUND/AIM The most effective method for human adult pancreatic islets purification is density-gradient centrifugation. The aim of this study was to analyze the effects of non-automated purification on preservation of functional capacity of human adult pancreatic islet cells. METHODS Human pancreata were obtained after pancreatectomy in the patients with chronic pancreatitis or benign tumors. Pancreatic islets were purified by non-automated method in discontinuous Ficoll density gradient. The samples were divided in 2 fractions: purified (P) and non-purified (NP) cultures. Islets were stained with diphenyl-thiocarbazone. The efficiency of separation was determined by comparing percentage of stained cells in P and NP cultures on day 1, 3 and 7 of shortterm cultivation. Glucose-stimulated insulin secretion was expressed as stimulation index (SI). RESULTS The results obtained showed a statistically significant difference (p < 0.01) between P and NP cultures. P cultures had higher percentages of stained cells (70.43 +/- 3.97%, 73.77 +/- 4.22% and 71.34 +/- 4.69% on the first, third and seventh day of cultivation, respectively) than NP cultures (53.68 +/- 1.71%, 57.14 +/- 3.94% and 43.97 +/- 4.56%, respectively). P cultures had higher values of SI for the first, third and seventh day of cultivation than NP cultures (0.45 +/- 0.08, 0.80 +/- 0.21, 1.28 +/- 0.15 and 0.46 +/- 0.10, 0.752 +/- .0.16, 0.76 +/- 0.11 for P and NP cultures respectively). The difference was statistically significant on day seven (p = 0.01). CONCLUSION Although during purification process islets were exposed to a number of insults that might result in cellular damage and functional impairment, our assessments showed that islets in P cultures preserved their functional capacity better than islets in NP cultures, since they had greater insulin secretion.

We investigated the influence of short-term culture in vitro on the appearance of apoptosis of human fetal pancreatic islets (HFIs) and its effect on the mass and insulin-secretory capacity (ISC) of ?-cells. It was found that apoptosis was present from the end of the culture period, increasing as a function of time and leading to decrease of ?-cell mass. At the same time, ISC decreased. The decrease of ?-cell mass and ISC may influence significantly the clinical outcome of HFIs transplantation in type 1 diabetic patients.

Summary: Oxidative stress and hyperglycemia play an important role in the aethiology of vascular complications in diabetes. Hyperglycemia induces a large number of alterations in vascular tissue that potentially accelerate the atherosclerotic process. Nonenzymatic glycosylation of proteins and lipids which can interfere with their normal function by disrupting molecular conformation, alter enzymatic activity, reduce degradative capacity and interfere with receptor recognition, oxidative stress and protein kinase C activations are the major processes that encompass most of the pathological alterations in the diabetic vasculature. Diabetes-associated oxidative stress is a consequence of both increased production of free radicals and reduced capacity for antioxidative defense. The aim of this study was to test the parameters of antioxidative defense: superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and total antioxidant status (TAS), in type 2 diabetic patients with and without cardiovascular complications in order to determine the effect of hyperglycemia on the extent of disorders of antioxidative parameters. Sixty nine type 2 diabetic patients with cardiovascular complications, along with 48 diabetics without complications and 42 healthy subjects were examined. Determination of antioxidant parameters was performed using commercial tests manufactured by Randox Laboratories, UK, based on spectrophotometer determination methods. Statistical data processing revealed significantly lower SOD, GSH-Px, GR and TAS values in type 2 diabetic patients with cardiovascular complications in comparison to the control group (p