ASCORBIC ACID MODULATES SPONTANEOUS THYMOCYTE APOPTOSIS

The aim of the paper was to analyze the effect of various concentrations of ascorbic acid on spontaneous apoptosis of lymphocytes.About 58% of all thymocytes are subjected to a spontaneous apoptosis, after 24-hour cultivation in the complete medium. The number of apoptotic thymocytes was much lower in the culture with different concentrations of ascorbic acid. The most dramatic effect was detected in the culture with the highest concentration of ascorbic acid (10000 μg/ml). In this culture, the number of apoptotic thymocytes was about 32%. These results, compared with the results of spontaneous apoptosis, show that the most significant inhibition of apoptosis was detected in the culture with 10000 μg/ml of ascorbic acid. High concentration of ascorbic acid can inhibit spontaneous apoptosis of thymocytes. Such inhibition of T cell apoptosis, as the effector cells in immune system, can represent one of the major factors by which ascorbic acid influence the immune system

Hypoplastic arteries of the cerebral arterial ring in the blind spot of computed tomography angiography

Background: Some variations of the cerebral arterial circle (CAC) are associated with an increased risk for the development of various pathological conditions. This paper aimed to determine the prevalence of hypoplastic arteries of CAC and to emphasize the limited possibility of their visualization by computed tomography angiography (CTA). Materials and methods: The research was performed on 400 adult cadavers by macro- and microdissection of the cerebral arteries. Each case was photographed and the diameter of the arteries was measured digitally, by analyzing photographs of the bases of the brain in the ImageJ program. Results: The largest prevalence of artery diameter <1mm (<0.6mm) in CAC had the posterior communicating artery (PCoA). PCoA on the left side was hypoplastic in 44.9% (11.4%) of cases, while the same artery on the right side was hypoplastic in 44.3% (6.6%) of cases. The posterior cerebral artery was hypoplastic on the left side in 3% (0.6%) and on the right side in 4.2% (0.6%) of cases. The anterior cerebral artery had a hypoplastic caliber only on the right side in 2.4% (0.6%) of the cases, while the internal carotid arteries did not have a diameter <1mm in any case. The anterior communicating artery showed the greatest variability in morphology. Studies on CTA describe the occurrence of aplasia in a statistically significantly higher percentage, and the occurrence of hypoplastic arteries in a statistically significantly lower percentage compared to studies on cadavers. Conclusions: Due to significant differences between cadaveric and radiological studies, it is necessary to analyze their results regarding arterial hypoplasia and aplasia separately. A diameter of less than 1 mm has been suggested as a criterion for arterial hypoplasia

Original paper<br>The effect of monosodium glutamate on rat thymocyte proliferation and Bcl-2/bax protein expression

Introduction: Monosodium glutamate (MSG) is one of the commonest food additives in modern nutrition. Recent studies showed the modulatory effect of MSG on rat thymocyte apoptosis in vivo and under in vitro conditions. However, the influence of MSG on thymocyte proliferation is largely unknown. Material and methods: We evaluated the effect of increased MSG concentrations on thymocyte proliferation, as well as the expression of their two apoptosis-related proteins, Bcl-2 and Bax. Proliferation was detected by PCNA monoclonal antibody, and cells were analyzed using a flow cytometer. Expression of Bcl-2 and Bax protein were determined with flow cytometry, using respective monoclonal antibodies. Results: The results obtained in our study demonstrate that MSG significantly decreased thymocyte proliferation, in a dose dependent manner, followed by significantly increased cytotoxicity. The expression of Bcl-2 protein was significantly decreased, while Bax protein expression was not changed in our study. Conclusions: The results presented in our study indicate that MSG significantly modulated intensity of thymocyte proliferation as a consequence of increased cytotoxicity. The expression of Bcl-2 and Bax proteins suggests that this protein level is an important event in thymocyte cytotoxicity, triggered by MS

THE EFFECT OF QUERCETIN ON RAT THYMOCYTE MITOCHONDRIA TREATED WITH MANCOZEB

Quercetin is one of the most commonly used flavonoids, which people continuously consume through food. This flavonoid has potent antioxidant and anti-inflammatory effect. In the current study, we evaluated the effect of Mancozeb (0.2, 2 I 5 µg/ml), Mancozeb and quercetin, only qercetin (10mM) on viability, apoptosis, ROS production and mitochondrial membrane potential (MMP) in rat thymocytes, in in vitro conditions. The application of Mancozeb resulted in dose-dependent reduction of cell viability, apoptosis induction, which was followed by increased ROS production and MMP reduction. Quercetin significantly reduced the cytotoxicity in cell cultures with 0.2 and 2µg/ml of Mancozeb, together with the reduction of ROS and MMP increase. Quercetin in cell cultures treated with 5µg/ml of Mancozeb failed to reduce toxicity but increased the total number of apoptotic cells. The obtained results show that ROS production, together with mitochondrial dysfunction, may represent a key factor in toxicity induced by Mancozeb. The application of quercetin reduces cell toxicity which is induced by lower Mancozeb concentrations, with a possibility to induce apoptosis and prevent necrosis, with final reduction of the development of secondary immunological consequences

PENICILLIN EPILEPSY IN RATS

The purpose of this study is to test, in a model of experimental penicillin epilepsy, a hypothesis of primary and dominant role of cortex in genesis of epileptic discharges, by using recordings of electrocorticograms (EcoG). The experiments were made with around two and a half old male rats. The rats were divided into four groups of five animals each. In the case of the first group, antibiotics were applied intraperitoneally (i.p.). Epileptic generalized discharges of this group were not registered until administering a dosage of antibiotics higher than 1.8 x 106 IU/kg. In the second group, application of a dosage of 1.2 x 106 IU/kg resulted in individual discharges. In the third group, antibiotics were applied intracortically (i.c.) in a dosage of 50 IU and caused individual discharges without big seizures. The fourth group needed a dosage of 100 IU/kg of penicillin applied i.c. to develop a big seizure. Discharges in the first three groups were registered first as unilateral with a subsequent development of bilateral synchrony. In the case of the fourth group, immediately and abruptly after the application of penicillin big seizures developed violently and repeated several times. We consider that the very implantation of electrodes provokes occurrence of discharging

ORIGINAL PAPER <br> The effect of monosodium glutamate on the apoptosis of rat thymocytes and Bcl-2 protein expression

Introduction: Monosodium glutamate (MSG) is the sodium salt of glutamic acid widely spread in modern nutrition. Numerous recent studies have shown the existance of glutamic receptors on different non-neuronal cells, which among others also include lymphocytes and thymocytes. However, it has not yet been precisely established what modulatory effect is created by the activation of these receptors on the immune system cells. Material and methods: We have evaluated the effect of different MSG doses on the intensity of apoptosis of rat thymocytes, as well as the expression of their antiapoptotic protein, Bcl-2. Apoptosis was detected using the Annexin V-FITC apoptosis detection kit and cells were analysed using a flow cytometer. Expression of Bcl-2 was determined with flow cytometry using respective monoclonal antibodies. Results: The current study results demonstrate that different MSG doses significantly increase the intensity of thymocyte apoptosis in a culture. Also, the expression of Bcl-2 proteins in the thymocyte culture, after it has been cultivated with different MSG doses, is significantly reduced. Conclusions: The results presented in our study indicate that different MSG doses significantly modulate the intensity of the apoptotic thymocyte process in a culture, and that one of the possible ways through which MSG induces apoptosis is the reduction of Bcl-2 protein expression

Therapeutic role of methotrexate in pediatric Crohn’s disease

The main role of therapy in Crohn’s disease (CD) is to achieve long-term clinical remission, and to allow for normal growth and development of children. The immunomodulatory drugs used for the maintenance of remission in CD include thiopurines (azathioprine and 6-mercaptopurine) and methotrexate (MTX). Development of hepatosplenic T-cell lymphoma in some patients with inflammatory bowel disease, treated with thiopurines only or in combination with anti-tumor necrosis factor agents, resulted in a growing interest in the therapeutic application of MTX in children suffering from CD. This review summarizes the literature on the therapeutic role of MTX in children with CD. MTX is often administered as a second-line immunomodulator, and 1-year clinical remission was reported in 25–69% of children with CD after excluding for the use of thiopurines. Initial data on MTX effectiveness in mucosal healing, and as a first-line immunomodulator in pediatric patients with CD, are promising. A definite conclusion, however, may only be made on the basis of additional research with a larger number of subjects