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.

In-Line Phase Contrast Mammography, Phase Contrast Digital Breast Tomosynthesis, and Phase Contrast Breast Computed Tomography With a Dedicated CT Scanner and a Microfocus X-Ray Tube: Experimental Phantom Study

Abstract: We performed laboratory investigations of the image quality for 2-D [digital mammography (DM)] and 3-D [digital breast tomosynthesis (DBT) and computed tomography (CT)] in-line phase contrast imaging dedicated to the breast. We employed the cone-beam, microfocus CT scanner developed in-house. Planar imaging tests were carried out with BR50/50 and polymethylmethacrylate test objects, at tube voltages of 60 kV, 80 kV, and 100 kV. CT volume images, acquired at 80 kV at dose levels comparable to two-view mammography (mean glandular dose $\cong ~4$ mGy), as well as at 120 kV, were reconstructed from phase contrast projection images as well as from the corresponding phase retrieved projection images (Paganin’s algorithm). We assumed 3-D spatial uniform distribution of the ratio $\delta /\beta $ of the X-ray optical coefficients of the sample material, at the effective energy of the X-ray beam. In 2-D imaging, all phantom details showed higher contrast after phase retrieval. In particular, contrast-to-noise ratio between a simulated mass and phantom background in phase retrieved images resulted up to 6.5 times higher than for absorption-based images. CT and DBT phase retrieval images of a homogeneous 50/50 test object at 120 kV produced higher signal-to-noise ratio of microcalcifications than in phase contrast DBT and CT of the same object, at the same glandular dose. In CT reconstructed volume images, microcalcifications down to 0.230–0.290-mm size presented an increased visibility after phase retrieval, in a two-components 50/50 breast phantom. For the first time, the advantages of in-line phase imaging in microfocus breast imaging have been shown with one setup for all techniques (DM, DBT, and breast CT). These results motivate further research on in-line phase contrast 2-D and 3-D imaging of the breast with a microfocus X-ray tube for potential application in the clinic of in-line phase contrast DM, DBT, and breast CT at dose levels comparable with corresponding attenuation-based exams.

Application of chlorhexidine in endodontics

Abstract: Introduction: Bacterial populations in the root canal must be eliminated or at least significantly reduced to levels compatible with the healing process of periapical tissues in order to achieve optimal results of the performed endodontic treatment. Irrigation solutions play an important role in the removal of infected tissue, bacteria and their breakdown products, and also affect the decomposition of organic and inorganic matter in the root canal system. Medications currently used in root canal cleaning and preparation are NaOCl, CHX, EDTA and MTAD. None of these solutions has all the characteristics of an ideal irrigator. Aim: The aim of this study is to present chlorhexidine (CHX) as a drug used in endodontics, as well as describe its advantages and disadvantages. We will consider its structure and mechanisms of action as well as the target group of microorganisms it affects. Materials and Methods: We have reviewed studies and articles published by foreign and Bulgarian authors in order to present CHX as a medicine, used in endodontics. The main topic of the review is to emphasize the benefits of using it. Conclusion: CHX has a broad spectrum of antimicrobial activity against gram positive and gram-negative bacteria, but it does not have the ability to dissolve organic tissue. Therefore, it will not be effective when used alone. CHX can be very beneficial in reducing the amount of pathogenic bacteria inside the root canal system, which makes it an ideal irrigator for the final rinse of the root canal. Mixing CHX with Ca(OH)2 may increase its antimicrobial activity.

Effect of aronia melanocarpa fruit juice on reserpine-induced hypokinesia and oxydative stress in rats

Abstract: INTRODUCTION: Reserpine can cause hypokinesia due to depletion of monoamine stores in the central nervous system. PURPOSE: The aim of the present study was to investigate in the effects of Aronia melanocarpa fruit juice (AMFJ) on reserpine-induced hypokinesia and oxidative stress in male Wistar rats. MATERIAL AND METHODS: Reserpine was applied as a single intraperitoneal dose of 6 mg/kg (as a 0.3% solution in 5% DMSO, 2 ml/kg) and comparisons were made with the control group injected intraper- itoneally with 5% DMSO (2 ml/kg). AMFJ was applied orally at doses of 2.5 ml/kg, 5 ml/kg and 10 ml/kg three times (on the 0 th , 19 th and 23 rd hour) after reserpine administration while the control group received distilled water (10 ml/kg) at the same time points. The open field test (OFT) was used for investigation of lo- comotor activity. Oxidative stress was evaluated by the concentration of thiobarbituric acid reacting sub- stances (TBARS) in rat brain. RESULTS: Reserpine induced a significant reduction (p<0.001) in both horizontal and vertical locomotor activity of rats. Brain TBARS in reserpine-treated animals were significantly higher (p<0.05) in compari- son with those of the control rats which indicated that reserpine induced oxidative stress. AMFJ caused a non-significant increase in locomotor activity of reserpine-treated rats. The concentration of TBARS in the brains of rats treated with AMFJ after reserpine did not differ significantly from the control level.

Study of the level of 25-hydroxyvitamin D in patients with seborrheic dermatitis

Abstract: PURPOSE: Seborrheic dermatitis is papulosquamous disorder affecting 3-5% of the population. Its pathogenesis is not elucidated yet. The purpose of our study was to find out the serum level of 25-hydroxyvitamin D (25-(OH) vitamin D) in patients with clinicaly manifested seborrheic dermatitis. MATERIAL AND METHODS: Twenty-two patients, 11 females and 11males, were examined for serum 25-(OH) vitamin D. One patient was at remission stage. The values were measured by means of electrochemiluminescence immunoassay analyzer. The study was carried out between November and August. RESULTS: During the whole period of the study none of the patients showed optimal level of serum 25-(OH) vitamin D. Three patients presented with suboptimal values of 25-(OH) vitamin D (13.6% of the cases). The rest 19 patients (86,3%) showed insufficiency of 25-(OH) vitamin D with values under 30 ng/mL and 13 of them (68.4%) were with pronounced deficiency - serum 25-(OH) vitamin D under 20 ng/mL. Only two patients (10.5%) presented with a severe deficiency and value of 25-(OH) vitamin D under 10 ng/mL. CONCLUSION: We could conclude that the patients with exacerbated seborrheic dermatitis present with 25-(OH) vitamin D insufficiency and deficiency. Our results allow us to suggest that vit. D may play a role in the pathogenesis of seborrheic dermatitis. Consequently, its supplementation may be used in the treatment of this pathology. To our knowledge, this is the first study of serum 25-(OH) vitamin D levels in patients with seborrheic dermatitis and these results promise multiple directions for further research. Scripta Scientifica Medica 2013; 45(1): 75-78.

Comparison of fatty acids, cholesterol, fat soluble vitamins and carotenoids content of skin and edible tissue of farmed African catfish (Clarias gariepinus, Burchell 1822)

Abstract: Abstract African catfish (Clarias gariepinus) is new species for the Bulgarian market. It is a valuable source of biologically active components that play an important role in human diet, but there is lack of information for the quality of its dietary lipids. This study focuses on the assessment of skin and edible tissue lipid quality of farmed African catfish based on lipid content and detailed fatty acids, fat-soluble vitamins, cholesterol and carotenoids composition. Fatty acid composition was determined by gas chromatography with mass spectrometer (GC/MS) after lipid extraction. Vitamins A, D3 and E, beta-carotene, astaxanthin and cholesterol were analyzed simultaneously using high performance liquid chromatography (HPLC) with ultraviolet and fluorescence detectors. Lipids, cholesterol, astaxanthin and monounsaturated fatty acids (MUFA) were significantly higher in skin, whereas vitamin A and E, polyunsaturated fatty acids (PUFA) were higher in muscle tissue. Vitamin D3 showed comparable amounts in both tissues. Eicosapentaenoic acid (C20:5n3) and docosahexaenoic acid (C22:6n3) which are important indicators for fish lipids quality presented significantly high amounts. A portion of 100 g filet without skin contains approximately 600 mg. Results confirmed that African catfish meat - with or without the skin, can be valuable and preferable source of biologically active lipids.