Papers by Bistra Galunska
Journal of Chromatography B, 2007
A liquid chromatography method for simultaneous analysis of amino acids, polyamines, catecholeami... more A liquid chromatography method for simultaneous analysis of amino acids, polyamines, catecholeamines and metanephrines in human body fluids after derivatization with 9-fluorenylmethyloxycarbonyl chloride was developed. The chromatographic behavior of analytes at different pH of ...
Maturitas, 2014
Objectives: Vitamin K plays a pivotal role in the synthesis of Matrix Gla protein (MGP), a calcif... more Objectives: Vitamin K plays a pivotal role in the synthesis of Matrix Gla protein (MGP), a calcification inhibitor in vascular tissue. Vascular calcification has become an important predictor of cardiovascular disease. The aim of the current study was to examine the potential association of circulating desphosphocarboxylated and-uncarboxylated MGP (dp-cMGP and dp-ucMGP), reflecting vitamin K status, with the incidence of cardiovascular events and disease (CVD) in older individuals. Study design: The study was conducted in 577 community-dwelling older men and women of the Longitudinal Aging Study Amsterdam (LASA), aged >55 year, who were free of cardiovascular disease at baseline. Multivariate Cox proportional hazards models were used to analyze the data. Main outcome measures: Incidence of CVD. Results: After a mean follow-up of 5.6 ± 1.2 year, we identified 40 incident cases of CVD. After adjustment for classical confounders and vitamin D status, we observed a more than 2-fold significantly higher risk of CVD for the highest tertile of dp-ucMGP with a HR of 2.69 (95% CI, 1.09-6.62) as compared with the lowest tertile. Plasma dp-cMGP was not associated with the risk of CVD. Conclusions: Vitamin K insufficiency, as assessed by high plasma dp-ucMGP concentrations is associated with an increased risk for cardiovascular disease independent of classical risk factors and vitamin D status. Larger epidemiological studies on dp-ucMGP and CVD incidence are needed followed by clinical trials to test whether vitamin K-rich diets will lead to a decreased risk for cardiovascular events.
Cancers
The hallmark of multiple myeloma is myeloma related bone disease. Interactions between myeloma pl... more The hallmark of multiple myeloma is myeloma related bone disease. Interactions between myeloma plasma cells (MPCs), stromal cells, and the bone marrow (BM) microenvironment play a critical role in the pathogenesis of MBD. Bone remodeling is severely dysregulated with the prevalence of osteoclast activity. We aimed to assess circulating levels of sRANKL, periostin, and osteopontin as osteoclast activators in NDMM patients at diagnosis and in the course of treatment, correlations with clinical and laboratory data, and to evaluate their potential as additional biomarkers for the assessment of MBD. The current study involved 74 subjects (41 NDMM patients, 33 controls). MBD was assessed by whole-body low-dose computed tomography. sRANKL, periostin, and osteopontin were assayed by commercial ELISA kits. At diagnosis, all tested parameters were significantly higher in NDMM patients compared to the controls (p < 0.0001), correlating with disease stage, MBD grade, and BM infiltration by M...
Turkish Journal of Biochemistry
Objectives Plaque-induced gingivitis is one of the most widely distributed periodontal disorder d... more Objectives Plaque-induced gingivitis is one of the most widely distributed periodontal disorder during childhood. The control of the pathogenic potential of the plaque is associated with oral hygiene status at individual, group, and population levels. We hypothesize that regular application of complex oral hygiene-prophylaxis could beneficially modulate salivary amino acids profile in children with different stage of plaque-induced gingivitis. Therefore, we aimed to study the salivary amino acids’ profile in relation to certain clinical indicators and environmental variables for plaque-induced gingivitis in children. Methods Fifty children (29 girls, 21 boys; mean age 8.18 ± 2.32 years) without anamnestic data for common diseases, no medication, and no data for allergy were selected. Plaque and gingival indexes were determined for assessment oral hygiene and plaque accumulation. Unstimulated whole saliva was collected, centrifuged and supernatants stored at −80 °C. Amino acid analys...
The Kaohsiung Journal of Medical Sciences
The present cross‐sectional clinical study aimed to examine the connection between statin exposur... more The present cross‐sectional clinical study aimed to examine the connection between statin exposure, coronary artery calcification (CAC), and vitamin K‐dependent proteins (VKDPs) in patients with cardiovascular (CV) conditions. Two groups of patients were studied: patients with established CV disease (CVD) and healthy patients at moderate risk for CVD (a control group). The groups were also split into statin users and non‐users. The following VKDPs were measured in plasma: uncarboxylated Matrix Gla‐protein (ucMGP), undercarboxylated (ucOC), and carboxylated osteocalcin (cOC), Gla‐rich protein (GRP). CAC score (CACS) was determined by multislice computed tomography. Among all the participants in the study, CACS was more pronounced in statin users compared to non‐users; the same was found also among the CVD patients and among the controls. While the levels of ucMGP and GRP did not differ between statin users and non‐users, ucOC and ucOC/cOC were significantly elevated in statin users, ...
Scripta Scientifica Pharmaceutica, 2014
Scripta Scientifica Pharmaceutica, 2015
Introduction: Glutathione, a tripeptide normally found in nearly all mammalian cells, is the maj... more Introduction: Glutathione, a tripeptide normally found in nearly all mammalian cells, is the major intracellular non-protein thiol compound. Its metabolism in the body is described by the γ-glutamyl cycle. Glutathione has various important functions, including detoxification of xenobiotics and hydrogen peroxide and its role as an endogenous antioxidant. It can exist in reduced (GSH) and oxidized state (GSSG). The ratio of these two forms of glutathione determines the cell redox potential and is used as an indicator for oxidative stress. Determining blood and plasma concentrations of total (tGSH), reduced (GSH) and oxidized (GSSG) glutathione provides information on the oxidative status of the human organism. Aim: To overview the recent analytical methods for quantitative analysis of blood glutathione concentration and to analyze their strengths and limitations. Materials and methods: Systematic review of web databases (PubMed, ScienceDirect and Google Scholar) on the problem. Res...
This paper aims at improving the content of the biochemistry curriculum and the methods by which ... more This paper aims at improving the content of the biochemistry curriculum and the methods by which it was delivered at the Medical University of Varna in terms of course content, examination standards and obtaining a feedback from the students. The paper presents two-year follow-up outcomes. A working collaboration was established with two Western European Universities, the University of Marburg, Germany and the University of Dundee, UK. The innovative teaching methodology developed and used in the Department of Biochemistry at the University of Dundee was adopted considering the particular circumstances in the Medical University of Varna. The content of the basic biochemistry course was revised and expanded emphasizing the molecular basis of metabolic variation between different organs and molecular events and clinical medicine. New clinically case-oriented studies of biochemically-based disorders were introduced for the first time in the basic biochemistry course in the form of tuto...
Th conference is organised with the fiancial support of European Social Fund within the Project B... more Th conference is organised with the fiancial support of European Social Fund within the Project BG051PO001-3.1.07-0046 “Updating and approbation of the curricula of the Faculty of Pharmacy, Medical University of Varna according to the needs of the pharmaceutical business and the requirements of the labor market”
Twenty five-hydroxy-vitamin D (25OHD) levels are accepted as an indicator for vitamin D status an... more Twenty five-hydroxy-vitamin D (25OHD) levels are accepted as an indicator for vitamin D status and their measurement is still a challenge. The aim of the present study was to develop a robust and easy to use HPLC-method for simultaneous analysis of 25OHD 2 and 25OHD 3 in human plasma and to assess its analytical performance, Protein precipitation followed by liquid-liquid extraction with n-hexane was used for separation from the matrix substances. A HPLC-system with UV detector (Thermo Scientific Spectra System, USA) was used. HPLC-UV analysis was performed on a Synergy hydro-RP column 4,6x250 mm, 4.0 µm particle size with mobile phase consisting of methanol/acetonitrile/water (70/25/5) under isocratic elution at a flow rate of 1.2 mL/min and UV-detection at 265 nm. Our HPLC-method was compared with a validated ID-LC-MS/MS method and with a commercial immunochemical method. Linear regression was used for data analysis. Linearity of the HPLC-assay was between 5-160 ng/ml for each ana...
Vitamin K has long been associated solely with its role in haemostasis. The last two decades brou... more Vitamin K has long been associated solely with its role in haemostasis. The last two decades brought new intriguing insights to the function of vitamin K. While the present recommendations for daily intake are based mainly on amounts required to maintain coagulation, they may not be high enough to ensure adequate functions of vitamin K not involved in blood clotting, In the present review the role of vitamin K on bone in health and disease is being discussed. Theoretical grounds connected with the function and diagnostic application of the vitamin K-dependent protein osteocalcin is described. Available clinical data related to the use of vitamin K in the prevention and treatment of osteoporosis is provided.
Vitamin D deficiency is highly prevalent among children worldwide. It includes impaired immune re... more Vitamin D deficiency is highly prevalent among children worldwide. It includes impaired immune response to infection and decreased activity of gut antimicrobial peptides. Elucidating the impact of vitamin D deficiency for the severity of acute diarrhea among children may be helpful for the disease management. Determination of vitamin D status in toddlers with acute diarrhea and evaluation the relationship with diarrhea severity. 77 children (1.0–3.5 years) with acute diarrhea, hospitalized in the Department of Infectious diseases were enrolled in the study. The patients were divided into 2 groups: with risk factors for severe diarrhea (group A, n=30) and group B without risk factors (n=47). The severity of diarrhea was assessed by the number of stools. The levels of circulating vitamin D were assayed by liquid chromatography with tandem mas-spectrometric detection. One way ANOVA and Kruskal Wallis statistics were used for statistical analysis. Patients in group A were vitamin D insu...
Clinical Laboratory, 2020
BACKGROUND Inflammatory bowel disease (IBD) is a multifactorial immunologically mediated disorder... more BACKGROUND Inflammatory bowel disease (IBD) is a multifactorial immunologically mediated disorder characterized by repeated cycles of exacerbations and remissions. Diagnosis and monitoring of ulcerative colitis (UC) and Crohn's disease (CD) as common types of IBD require the usage of unpleasant invasive methods such as colonoscopy and cross-sectional imaging. Development of a non-invasive biomarker panel including different inflammatory parameters for evaluation of various aspects of gut inflammation and disease course is a priority task. In addition to the well-known inflammatory markers serum C-reactive protein (CRP) and fecal calprotectin (FC), adenosine deaminase (ADA) could be a promising candidate-biomarker. ADA has been shown to increase in several inflammatory conditions, but little is known about its significance in IBD. This preliminary research aims to study the serum levels of ADA in IBD patients and to evaluate its ability to adequately reflect the gut inflammatory process. METHODS Fifty-four IBD patients (40 with UC and 14 with CD) and 50 controls were enrolled in the study. Routine laboratory parameters such as white blood cells (WBC) count, erythrocyte sedimentation rate (ESR), and CRP were used. The specific biomarker for intestinal inflammation FC was measured by sandwich immunoassay (BÜHLMANN) and ADA activity - by two-step enzyme method (BioSystems). RESULTS The median [IQR: 25th - 75th percentile] ADA values in IBD patients were significantly higher than those in the controls (18.7 U/L [15.4 - 22.5] vs. 9.10 U/L [7.1 - 11.2] respectively; p < 0.0001). A significant difference was obtained when comparing median ADA values in patients with active disease (20.4 [17.8 - 25.3] U/L) with those in patients with mild form of the disease or in remission (15.3 [13.0 - 16.0]; p < 0.0001). A strong positive correlation between ADA and FC (r = 0.63; p < 0.0001) and moderate positive correlation between ADA and CRP (r = 0.46; p < 0.001) were observed. ROC-curve analysis revealed good ability of ADA to discriminate not only IBD patients from healthy individuals, but also patients with active disease and those in remission/mild form. CONCLUSIONS The present study revealed that ADA levels were significantly increased in IBD patients. Together with FC and CRP, ADA could be used as an effective biomarker for assessment of intestinal inflammation and as a potential indicator for disease activity.
Journal of Liquid Chromatography & Related Technologies, 2019
A new and simple LC-MS method for analysis of flavonoids from Sambucus ebulus berry extracts was ... more A new and simple LC-MS method for analysis of flavonoids from Sambucus ebulus berry extracts was developed and validated. Successfully were quantitated seven polyphenols: epicatechin, epigallocatechin gallate, rutin, resveratrol, myricetin, quercetin, and kaempferol. Two detectors, working in parallel, were used: photodiode-array and single quadrupole massdetector. The mass detection was used for identification and quantification of the analytes, while the diode-array detector was as confirmation tool. The following m/z were tracked: 457.15 (epigallocatechin gallate); 289.06 (epicatechin); 609.13 (rutin); 227.05 (resveratrol); 317.0 (myricetin); 301.02 (quercetin); 285.02 (kaempferol). For optimization the chromatographic separation three wavelengths 205 nm, 305 nm, 272 nm were monitored. The method was capable to detect in one run compounds with no UV or fluorescence chromophore and with very similar structures, such as plant polyphenols. The linearity was from 0.05 mg/L to 50 mg/L (R 2 0.9962-0.9987). The recoveries for all tested analytes were between 81.6% and 104.7%. The method was applied for analysis of crude extract of Sambucus ebulus ripe fruits. Three major polyphenolsepicatechin (0.84 mg/100gFW), quercetin (0.15 mg/100gFW) and kaempferol (0.05 mg/100gFW) were identified and quantified. The proposed method could be successfully used for routine analysis of epigallocatechin gallate, epicatechin, rutin, resveratrol, myricetin, quercetin, and kaempferol in Sambucus ebulus extracts.
International Journal of Experimental Pathology, 2017
SummaryEpidemiological studies reveal associations between obesity/metabolic syndrome and mood di... more SummaryEpidemiological studies reveal associations between obesity/metabolic syndrome and mood disorders. We assessed behavioural changes in rats fed diets enriched in fat and fructose in different proportions and correlated the observed alterations with biochemical changes induced by the diets. Three groups of rats were used as follows: control (C) animals fed regular rat chow, rats fed high‐fat diet (HF) and rats fed high‐fat and high‐fructose diet (HFHF). HF and HFHF animals were also given a 10% fructose solution as drinking water. Behavioural and biochemical parameters were determined. Anxiety was measured by the open‐field and the social interaction test. Depression‐like behaviour was evaluated by the forced swimming test. The object recognition test was utilized to assess effects on memory. Diet‐exposed animals displayed signs of anxiety in the open‐field (HF rats had reduced central time; HFHF rats had reduced number of central entries) and in the social interaction test (de...
Biological Markers in Fundamental and Clinical Medicine (collection of abstracts), 2018
Advances in Materials and Processing Technologies, 2015
ABSTRACT Austenitic stainless steel is one of the materials commonly used for manufacturing of or... more ABSTRACT Austenitic stainless steel is one of the materials commonly used for manufacturing of orthodontic appliances and brackets. In the present study samples of AISI 321 (EN X6CrNiTi 18-10) steel in initial condition and after laser surface melting were investigated in artificial saliva with pH 5,6. Two tests were conducted: measurement of open circuit potentials (free potentials) Ef until reaching steady state potentials Ess and potentiodynamic anodic polarization. The samples’ surface was characterized by SEM and EDX analysis was also done. Small amount of pits were observed on the surface of all samples – untreated and laser melted layers as well. The steady state potential of the base metal was about +238 mV, while that of the laser melted layers was approximately 50 mV lower. The pitting potentials Epit of the laser treated samples were lower than that of the untreated stainless steel (+802 mV). It was established that the laser melted surface layers of stainless steel are more susceptible to pitting corrosion in artificial saliva with higher acidity than the base metal.
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Papers by Bistra Galunska