Browsing by Author "Petrovic, Milan (56240355100)"

Various studies have shown that the serum concentration of folic acid is inversely related to the serum homocysteine concentration. In addition, data suggest that increases in serum homocysteine levels decrease the activity of acetyl cholinesterase (AChE). The aim of this study was to investigate the effects of acute folic acid treatment on AChE activity in the brain, heart and the blood of a rat. We used male Wistar rats, with a body mass of 250-300 g divided into two categories: a control group given placebo (1 ml 0.9% NaCl, i.p. n1=6) and an experimental group treated with folic acid (1 ml 0.011 μmol/g per body mass, pH 7.4, i.p., n2=6). Sixty minutes after the treatment, the rats were decapitated. The brain and the heart were removed, and blood was taken. The brain and heart were homogenised in phosphate buffer pH 8 (1 ml buff er/20 mg tissue). Th e homogenised tissues and blood were used as a substrate for the spectrophotometric analysis, and enzyme activity was measured in vitro by the Ellman method. Rats treated with folic acid showed significantly reduced AChE activity in the brain and blood compared to the control group (38% and 82%, respectively). We did not observe a significant difference between the enzyme activity in the blood of treated versus untreated rats. In conclusion, this study shows that acute treatment with folic acid decreases the AChE activity in the brain and heart of rats without affecting the AChE activity in the blood.

AIM: To evaluate the clinical characteristics of splenic marginal-zone lymphoma (SMZL) following antigen expression and the influence of therapeutic approaches on clinical outcome and overall survival (OS). METHODS: A total of 30 patients with typical histological and immunohistochemical SMZL patterns were examined. Splenectomy plus chemotherapy was applied in 20 patients, while splenectomy as a single treatment-option was performed in 10 patients. Prognostic factor and overall survival rate were analyzed. RESULTS: Complete remission (CR) was achieved in 20 (66.7%), partial remission (PR) in seven (23.3%), and lethal outcome due to disease progression occurred in three (10.0%) patients. Median survival of patients with a splenectomy was 93.0 mo and for patients with splenectomy plus chemotherapy it was 107.5 mo (Log rank = 0.056, P > 0.05). Time from onset of first symptoms to the beginning of the treatment (mean 9.4 mo) was influenced by spleen dimensions, as measured by computerized tomography and ultra-sound ( t = 2.558, P = 0.018). Strong positivity (+++) of CD20 antigen expression in splenic tissue had a positive influence on OS (Log rank = 5.244, P < 0.05). The analysis of factors interfering with survival (by the Kaplan-Meier method) revealed that gender, general symptoms, clinical stage, and spleen infiltration type (nodular vs diffuse) had no significant ( P > 0.05) effects on the OS. The expression of other antigens (immunohistochemistry) also had no effect on survival-rate, as measured by a χ2 test ( P > 0.05). CONCLUSION: Initial splenectomy combined with chemotherapy has been shown to be beneficial due to its advanced remission rate/duration; however, a larger controlled clinical study is required to confirm our findings. © 2009 The WJG Press and Baishideng. All rights reserved.

Limited data exist in the literature regarding the effects of homocysteine thiolactone on the activity of the acetylcholinesterase (AChE) in the blood, and practically no data exist regarding the influence of homocysteine thiolactone on the enzyme in the brain and heart. Taking into consideration the importance of hyperhomocysteinemia in clinical practice, it has been thought to be of particular interest to examine the effect of homocysteine thiolactone on the activity of AChE in the rat's blood, brain and heart. In this study, male Wistar rats (weighing 250-300g) were used, and they were divided into two groups; one served as a control group and receieved a placebo (1 ml 0.9 % NaCl, i.p.), while the other group received a homocysteine thiolactone solution (5.5 mmol/kg b.m., i.p.). An hour after the administration, the rats were euthanized by decapitation, heir tissues were harvested, buffered, and homogenized in a phosphate buffer (pH 8). The concentration in the tissue homogenates was 20 mg of tissue per 1 ml of buffer. The buffered and homogenized parts of the tissues were used as substrates for spectrophotometric measurements. The AChE activity was then measured by the Ellman method. Statistical analysis was conducted using a one-way ANOVA test, and the intergroup comparisons were performed using a Bonfferoni test. The results showed a significant reduction in AChE activity in all tissues obtained from the animals treated with homocysteine thiolactone compared to the enzyme activity of the control group. In addition, the results also showed that the blood enzyme activity inhibition was the lowest (12%), while the enzyme activity was slightly higher in the brain (27.8%) and heart specimens (86.3%). It was concluded that homocysteine thiolactone significantly inhibited AChE activity in the heart and brain tissue, but not in the blood of the rat.