Medical University of Varna

About: Medical University of Varna is a education organization based out in Varna, Varna, Bulgaria. It is known for research contribution in the topics: Population & Medicine. The organization has 1199 authors who have published 1273 publications receiving 32940 citations. The organization is also known as: MU-Varna & Higher Medical Institute of Varna.

Ethanol induces IL-6 and TNF-α cytokine and iNOS and COX-2 enzyme gene expression in 3T3-L1 preadipocytes

Abstract: t is known that alcohol influences on human health and its effects are widely studied. Adipose tissue (AT) may be an important target of ethanol action. Data about the effect of ethanol on cytokine and pro-inflammatory enzymes` gene expression in adipocytes are scarce. The aim of the present study was to establish its effect on transcription of inflammatory markers IL-6, TNF-α, COX-2 and iNOS in cultured 3T3-L1 cells. MTT test was performed in order to determine ethanol effect on cell viability. Expression of selected genes was measured using two step quantitative PCR. Results were analyzed using 2-I”I”Ct method. Exposure of 3T3-L1 cells to increasing ethanol concentrations (0.125%-0.625%) resulted in gradual cell viability decline. Expression of all the genes studied was up-regulated upon ethanol treatment. In cells treated with 0.5% ethanol, there was a 4.8- (p < 0.001), 6.3- (p<0.001), 5.5- (p<0.05) and 3.6- (p<0.05) fold increase of mRNA levels of IL-6, TNF-α, iNOS and COX-2, respectively, as compared with untreated controls. mRNA levels of the respective genes highly correlated with the applied ethanol concentration. In conclusion, our results show that ethanol treatment may increase the inflammatory potential of AT up-regulating expression of inflammatory cytokines IL-6 and TNF-α and inflammatory enzymes iNOS and COX-2 on transcription level. Scripta Scientifica Medica 2012; 44(2): 31-35.

JC polyomavirus in the aetiology and pathophysiology of glial tumours

Abstract: Glial brain tumours with their poor prognosis, limited treatment modalities and unclear detailed pathophysiology represent a significant health concern. The purpose of the current study was to investigate and describe the possible role of the human polyomavirus JC as an underlying cancerogenic or co-cancerogenic factor in the complex processes of glial tumour induction and development. Samples from 101 patients with glial tumours were obtained during neurosurgical tumour resection. Small tissue pieces were taken from several areas of the histologically verified solid tumour core. Biopsies were used for DNA extraction and subsequent amplification reactions of sequences from the JC viral genome. Real-time polymerase chain reaction was used for detection and quantification of its non-coding control region (NCCR) and gene encoding the regulatory protein Large T antigen (LT). An average of 37.6% of all patients was found to be LT positive, whereas only 6.9% tested positive for NCCR. The analysis of the results demonstrated significant variance between the determined LT prevalence and the rate for NCCR, with a low starting copy number in all positive samples and threshold cycles in the range of 36 to 42 representing viral load in the range from 10 to 1000 copies/μl. The results most probably indicate incomplete JC viral replication. Under such conditions, mutations in the host cell genome may be accumulated due to interference of the virus with the host cell machinery, and eventually malignant transformation may occur.

Liquid chromatography method for the simultaneous quantification of fat soluble vitamins in fish tissue

Abstract: The aim of the present study was to develop simple and accurate small-scale method for simultaneous determination of retinol, a-tocopherol, ergocalciferol, and cholecalciferol in edible fish tissue High performance liquid chromatography was the method of choice since it provides rapid, sensitive and accurate detection of all four fat-soluble vitamins and requires small amounts of sample The sample preparation procedure was improved using single reaction tube for both hydrolysis and extraction of the analytes The overall recovery exceeded 76% for retinol and ergocalciferol, 93% for al pha-tocopherol, and 83% for cholecalciferol The method precision (relative standard deviation) was below 10% for all analytes The method was verified on real fish tissue samples and the results for the tested fat-soluble vitamin contents were in a good agreement with the data given by other authors Scripta Scientifica Medica 2011;V43(1):35-38

Composition and antioxidant activity of aronia melanocarpa fruit juice

Abstract: Aronia melanocarpa is a woody shrub of the Rosaceae family. Its fruits are used for consumption either fresh, or as juice, jam and wine. The aim of the present study was to measure the concentration of some biologically active substances and the antioxidant activity of two samples of Aronia melanocarpa fruit juice (AMFJ). The juice was prepared from fresh fruits. One of the samples was produced using a juice centrifuge and was preserved with potassium sorbate (1.0 g/l). The other sample was produced by crushing and squeezing of fruits after which the juice was filtered and sterilized at 100 °C for 10 min. The contents of biologically active substances in the juice samples were measured by spectrophotometric and high-performance liquid chromatography methods. The antioxidant activity of the two juice samples was measured by the ORAC (oxygen radical absorbance capacity) and HORAC (hydroxyl radical аverting capacity) methods. The results showed that both samples were extremely rich in polyphenolic substances, amongst which the highest was the concentration of procyanidins followed by phenolic acids (chlorogenic and neochlorogenic) and anthocyanins. Sample 1 had higher concentration of total phenolics and contained higher quantities of most polyphenolic substances with the exception of anthocyanins. It also contained micro-quantities of cyanogens. The variations in the composition of the two samples could be attributed to the different methods of juice production and conservation. Both juice samples showed very high ORAC and HORAC values which were higher for sample 1 (the sample with the higher concentration of polyphenolic substances). The high antioxidant activity of the two AMFJ samples could be attributed to their polyphenolic ingredients.

Production of high-quality temporary crowns and bridges by stereolithography

Abstract: Introduction: Temporary crowns and bridges are the main elements in the treatment with fixed partial dentures. They are usually manufactured from methacrylate polymers and composites by heat-curing or CAD/CAM milling. Additive technologies (ATs) offer a number of advantages in the production of temporary dental restorations. However, there is a lack of information about the application of AT for manufacturing of provisional prostheses due to the multiple variants and complexity of their design as well as the wide variety of the 3D printing processes. Aim: The aim of the present paper was to establish the peculiarities in the production of high-quality temporary crowns and bridges by stereolithography (SLA) with digital light projection (DLP). Materials and Methods: Two groups of samples - cubic (5 mm x 5 mm x 5 mm) and four-part dental bridges (1-st premolar to 2-nd molar) were printed with different layer thickness - 35 µm and 50 µm from NextDent C+B polymer using RapidShape D30 . Results and Discussion: It was established that for effective production of temporary crowns and bridges with high dimensional accuracy and surface smoothness, it is necessary to take into account the peculiarities of the 3D printing process and to make corrections still at the stage of virtual model generation. Individual corrections of the dimensions along the separate axes of the virtual model have to be done with correction coefficients, depending on the construction type - crown or bridge. In order to obtain high smoothness, the construction should be positioned with the vertical axes of the teeth parallel to the printing direction (Z-axis). The number of the supports has to be increased (≥4 per tooth) for reduction of the deformations during 3D printing and final photopolymerization. Conclusion: The findings in the present study could be very helpful in the development of proper construction design and technological process for improving the quality of temporary restorations.