Fine-grained differences in gender-cue strength affect predictive processing in children: Cross-linguistic evidence from Russian and Bulgarian

We tested predictive gender agreement processing in adjective-noun phrases by 45 4- to 6-year-old Russian- and Bulgarian-speaking children using the visual world eye-tracking paradigm. Russian and Bulgarian are closely related languages that have three genders but differ in the nature and number of gender cues on adjectives. Analysis of the proportion and time course of looks to the target noun showed that only Bulgarian children used gender cues to predict the upcoming noun. We argue that the cross-linguistic difference in the gender cue strength is revealed through the operation of economy, transparency, and interdependence in a gender complexity matrix. The documented advantage for Bulgarian children in gender agreement processing and acquisition underscores the need for a comparative language acquisition approach to typologically close languages.

First detection of a cefiderocol-resistant and extensively drug-resistant Acinetobacter baumannii clinical isolate in Bulgaria

Cefiderocol (CFDC) is a first-in-class siderophore cephalosporin with potent activity against multidrug-resistant Gram-negative bacteria including carbapenem-resistant Acinetobacter baumannii. The present study aimed to explore the CFDC resistance mechanisms of an extensively drug-resistant A. baumannii isolate from Bulgaria. The A. baumannii Aba52 strain (designated Aba52) was obtained in 2018 from a blood sample of a critically ill patient. The methodology included antimicrobial susceptibility testing, whole-genome sequencing (WGS), reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), multilocus sequence typing, and phylogenomic analysis. The isolate demonstrated high-level resistance to CFDC (MIC = 64 mg L-1), resistance to carbapenems, aminoglycosides, fluoroquinolones, sulfamethoxazole-trimethoprim, and tigecycline, as well as susceptibility only to colistin. WGS-based resistome analysis revealed the existence of blaOXA-23, blaOXA-66 and blaADC-73. Seven non-conservative missense mutations affecting iron transport-related genes were detected: exbD4 (p.Ser61Pro), tonB2 (p.Ala268Val), bauA (p.Thr61Ala), ftsI (p.Ala515Val), piuA (p.Gly216Val), and feoB (p.Ser429Pro and p.Thr595Ala). A variety of virulence factors associated with adherence, biofilm formation, enzyme production, immune invasion, iron uptake, quorum sensing, and two-component regulatory systems were identified, suggesting a significant pathogenic potential of Aba52. The performed RT-qPCR analysis showed diminished (0.17) and absent expression of the pirA and piuA genes, respectively, encoding TonB-dependent siderophore receptors. Aba52 belonged to the widespread high-risk sequence type ST2 (Pasteur scheme). To the best of our knowledge, this is the first documented case of CFDC-resistant A. baumannii in Bulgaria even though, CFDC has never been applied in our country. The emerging resistance highlights the crucial need for nationwide surveillance targeting the implementation of novel antibiotics.

The acoustics of Contemporary Standard Bulgarian vowels: A corpus study

A comprehensive examination of the acoustics of Contemporary Standard Bulgarian vowels is lacking to date, and this article aims to fill that gap. Six acoustic variables-the first three formant frequencies, duration, mean f0, and mean intensity-of 11 615 vowel tokens from 140 speakers were analysed using linear mixed models, multivariate analysis of variance, and linear discriminant analysis. The vowel system, which comprises six phonemes in stressed position, [ε a ɔ i ɤ u], was examined from four angles. First, vowels in pretonic syllables were compared to other unstressed vowels, and no spectral or durational differences were found, contrary to an oft-repeated claim that pretonic vowels reduce less. Second, comparisons of stressed and unstressed vowels revealed significant differences in all six variables for the non-high vowels [ε a ɔ]. No spectral or durational differences were found in [i ɤ u], which disproves another received view that high vowels are lowered when unstressed. Third, non-high vowels were compared with their high counterparts; the height contrast was completely neutralized in unstressed [a-ɤ] and [ɔ-u] while [ε-i] remained distinct. Last, the acoustic correlates of vowel contrasts were examined, and it was demonstrated that only F1, F2 frequencies and duration were systematically employed in differentiating vowel phonemes.

Initial experience with Bulgarian Arthroplasty Register

INTRODUCTION

National arthroplasty registries date back to 1975, when the Swedish Knee Arthroplasty Register was founded. This method of database collecting has since been employed for both patient follow-up and the creation of annual statistical reports. In Bulgaria, there is currently no state-approved software that offers these features.

Current status and prognosis of Raphidiopsis raciborskii distribution in Bulgaria as part of the southeastern region of Europe

The cyanobacterial species Raphidiopsis raciborskii (Wołoszyńska) Aguilera et al. has a high invasiveness potential, which in less than a century leads to its cosmopolitan spread. In the temperate climate of Europe, R. raciborskii has been reported in many countries, but there is still a lack of detailed information about the current status of its distribution in lakes of Bulgaria, as a part of the southeastern range of its spread in Europe. We investigated the distribution of the species using data on the phytoplankton of 122 lakes surveyed during 13-years period (2009-2022). The species was found in 33 lakes (up to 324 m asl), and 14 new localities were registered during the studied period. The results reveal that the number of lakes with the presence of R. raciborskii (27 % of all research lakes) and its contribution to the total phytoplankton biomass, has increased significantly over the last decade. The species has successfully adapted and dominated the phytoplankton in 9 lakes, forming a bloom in 8 of them. The dominant position of R. raciborskii causes loss of species and functional diversity of phytoplankton and displaces the native bloom-forming cyanobacteria. Lakes with and without the species were compared based on the available data on bioclimatic and local environmental variables. Statistically significant differences were established with respect to water transparency, conductivity, maximum depth and maximum air temperature in the warmest month. Species distribution models (SDMs) were used to identify lakes in high risk of future invasion by R. raciborskii. The results of the SDMs implementation confirmed the high maximum air temperature and low water transparency to be important predictors of the occurrence of R. raciborskii in freshwater lakes in Bulgaria. In the areas with high summer temperatures the most suitable for R. raciborskii development were found to be shallow polymictic or medium deep lakes with small surface area and low water transparency. In areas with a suitable climate, the large, deep reservoirs with high transparency as well as macrophyte dominated lakes have a low probability of occurrence of R. raciborskii. Future colonization of lakes above 500 m asl (but most likely below 700 m asl) is also possible, especially in the conditions of global warming. SDMs account for climatic and biogeographic differences of lakes and could help in elucidating the underlying factors that control the occurrence and adaptation of R. raciborskii in a given area.

High-resolution characterization of KIR genes polymorphism in healthy subjects from the Bulgarian population-A pilot study

Although killer-cell immunoglobulin-like receptor (KIR) gene content has been widely studied in health and disease, with the advancement of next-generation sequencing (NGS) technology the high-resolution characterization of this complex gene region has become achievable. KIR allele-level diversity has lately been described across human populations. The present study aimed to analyze for the first time the allele-level polymorphism of nine KIR genes in 155 healthy, unrelated individuals from the Bulgarian population by applying NGS. The highest degree of polymorphism was detected for the KIR3DL3 gene with 40 observed alleles at five-digit resolution in total, 22 of which were common. On the other hand, the KIR3DS1 gene was found to have the lowest degree of polymorphism among the studied KIR genes with one common allele: KIR3DS1*01301 (31.6%). To better understand KIR allelic associations and patterns in Bulgarians, we have estimated the pairwise linkage disequilibrium (LD) for the 10 KIR loci, where KIR2DL3*00501 allele was found in strong LD with KIR2DL1*00101 (D' = 1.00, R2  = 0.742). This is the first study investigating KIR polymorphism at the allele level in a population from the South-East European region. Considering the effect of the populationally shaped KIR allelic polymorphism on NK cell function, this data could lead to a better understanding of the genetic heterogeneity of this region and can be carried into clinical practice by improvement of the strategies taken for NK-mediated diseases.

Virus-specific humoral immune response in Bulgarian COVID-19 patients with varying disease severity

INTRODUCTION

Our study aimed to analyze virus-specific humoral immune responses in COVID-19 patients with varying disease severity.

METHODOLOGY

A total of 109 serum samples from 87 patients, symptomatic for COVID-19 were studied using anti-SARS-CoV-2 immunoassays detecting different classes of immunoglobulins.

RESULTS

Clinical samples were divided into 2 groups - collected up to and more than 2 weeks post-onset of symptoms (PoS). In the first group, the highest percentage of positive samples was found for IgA class virus-specific antibodies (78.1%), followed by IgM (71.9%/59.4%) and IgG (56.3%/53.1%). In the second group, samples positive for virus-specific IgA class antibodies were also the most (97.7%) along with those positive for IgG. A total of 72 IgA and/or IgM and/or IgG positive samples were further tested for SARS-CoV-2 neutralizing antibodies (NAbs) - 89.1% and 100% of samples obtained up to and after 2 weeks PoS, respectively were positive. Serological test results were also analyzed depending on the severity of the disease - SARS-CoV-2 positive samples in mild forms of COVID-19 were fewer than in moderate and severe forms but this difference was not statistically significant.

CONCLUSIONS

SARS-CoV-2 specific antibodies and a high virus neutralization capacity of these antibodies appear early PoS; Immunoglobulins of IgA class are of most significant diagnostic value for detection of SARS-CoV-2 infection; Timing of testing is the most important factor for positivity rate.

High vaccine confidence and strong approval of the mandatory immunization schedule among Bulgarian general practitioners in 2022

In a context of recently decreasing childhood immunization coverage and low uptake of COVID-19 vaccines in Bulgaria, this study measures vaccine hesitancy among general practitioners (GPs) in the country, as they are central to forming patients' attitudes. In 2022, a face-to-face survey was conducted through a simple random sample from an exhaustive national database of Bulgarian GPs. This study measured attitudes on vaccine importance, safety, and effectiveness, and attitudes toward the Bulgarian immunization schedule. Information was collected on demographic and GP practice characteristics and possible predictors of vaccine confidence in order to test for associations with attitudes toward immunization. GP attitudes toward vaccines and the immunization schedule in Bulgaria were generally positive. Among 358 respondents, 351 (98%,95%CI96-99%) strongly agreed/agreed that vaccines are important, 352 (98%,95%CI96-99%) that vaccines are effective, and 341 (95%,95%CI93-97%) that vaccines are safe. 347 respondents (97%,95%CI95-98%) affirmed that "it's good that vaccines from the children's immunization schedule are mandatory", and 331 (92%,95%CI89-95%) agreed with the statement "Bulgaria's childhood immunization has my approval". Trust in information from official institutions was among the strongest predictors of vaccine confidence. Respondents' vaccine confidence levels are within the ranges reported by GPs in other European countries and above those reported within the general Bulgarian population. GPs' vaccine confidence is highly associated with trust in official institutions. It is important to maintain trust in official institutions and to support GPs in communicating vaccine knowledge with patients so that vaccine hesitancy in the general population is countered.

Cardiovascular Manifestations of Multisystem Inflammatory Syndrome in Children: A Single-Center Bulgarian Study

Background and objectives: Multisystem inflammatory syndrome in children (MIS-C) poses challenges to the healthcare system, especially with frequent heart involvement. The current retrospective observational study aims to summarize the type and degree of cardiovascular involvement in children with MISC and to find possible associations between laboratory, inflammatory, and imaging abnormalities and the predominant clinical phenotype using a cluster analysis. Material and methods: We present a retrospective observational single-center study including 51 children meeting the MIS-C criteria. Results: Fifty-three percent of subjects presented with at least one sign of cardiovascular involvement (i.e., arterial hypotension, heart failure, pericardial effusion, myocardial dysfunction, pericarditis without effusion, myocarditis, coronaritis, palpitations, and ECG abnormalities). Acute pericarditis was found in 30/41 of the children (73%) assessed using imaging: 14/30 (46.7%) with small pericardial effusion and 16/30 (53.3%) without pericardial effusion. The levels of CRP were significantly elevated in the children with pericarditis (21.6 ± 13 mg/dL vs. 13.9 ± 11 mg/dL, p = 0.035), and the serum levels of IL-6 were higher in the children with small pericardial effusion compared to those without (191 ± 53 ng/L vs. 88 ± 27 ng/L, p = 0.041). Pericarditis with detectable pericardial effusion was significantly more frequent in the female vs. male subjects, 72% vs. 30% (p = 0.007). The hierarchical clustering analysis showed two clusters: Cluster 1 includes the children without cardiovascular symptoms, and Cluster 2 generalizes the MIS-C children with mild and severe cardiovascular involvement, combining pericarditis, myocarditis, heart failure, and low blood pressure. Also, subjects from Cluster 2 displayed significantly elevated levels of fibrinogen (5.7 ± 0.3 vs. 4.6 ± 0.3, p = 0.03) and IL-6 (158 ± 36 ng/mL vs. 66 ± 22 ng/mL, p = 0.032), inflammatory markers suggestive of a cytokine storm. Conclusions: Our results confirm that children with oligosymptomatic MIS-C or those suspected of long COVID-19 should be screened for possible cardiological involvement.

nov.a new aphid species from Bulgaria (Hemiptera, Aphididae)

Here we present a description of a new aphid species from the subgenus Asterobium Hille Ris Lambers, 1938 of the genus Macrosiphoniella Del Guercio, 1911 in the tribe Macrosiphini Wilson, 1910 (Aphididae). The new speciesMacrosiphiniella (Asterobium) herczeki sp. nov. living on Galatella villosa (Asteraceae) in Tolbuchin region, Bulgaria, is described based on apterous viviparous females. The new species is morphologically similar to M. (Asterobium) konyratica Kadyrbekov, 2018 from Kazakhstan from which it differs in several morphological and metric characters. We provided an updated key to Blackmans & Eastop online key to Aster-feeding aphids.

Efficacy and safety of TV-46000, a long-acting, subcutaneous, injectable formulation of risperidone, for schizophrenia: a randomised clinical trial in the USA and Bulgaria

BACKGROUND

TV-46000 is a long-acting, subcutaneous, antipsychotic agent that combines risperidone and an innovative, copolymer-based drug delivery technology in a suspension that was approved in April, 2023 for subcutaneous use. The aim of the phase 3 Risperidone Subcutaneous Extended-release (RISE) study was to evaluate the efficacy of TV‑46000 in schizophrenia.

METHODS

The RISE study consisted of two treatment stages: a 12-week, open-label stabilisation phase with oral risperidone (stage 1), and an open-ended, randomised, double-blind, placebo-controlled, relapse-prevention phase with subcutaneous TV-46000 (stage 2) done at 69 clinical sites across the USA and Bulgaria. Patients diagnosed with schizophrenia more than 1 year before screening by DSM-5 criteria and confirmed at screening by the Structured Clinical Interview for DSM-5 and who had at least one relapse within 24 months before screening were eligible for enrolment. Patients who were outpatients and stabilised in stage 1 continued to stage 2 and were randomly assigned 1:1:1 by a computer-generated randomisation list to receive either subcutaneous TV-46000 once monthly, TV-46000 once every 2 months, or placebo until relapse, early discontinuation, or the study was stopped because the prespecified stopping criterion of at least 90 relapse events was met. The primary endpoint was time to impending relapse of the intention-to-treat patient population in stage 2. This study is registered with ClinicalTrials.gov, number NCT03503318, and is complete.

FINDINGS

The study enrolled the first patient on June 1, 2018, and the last patient completed on Dec 3, 2020. 1267 patients were screened, 863 enrolled, and 544 (male, n=332 [61%], female, n=212 [39%]; mean [SD] age, 49·3 [10·98] years; Black or African American, n=322 [59%]; White, n=206 [38%]; Asian, n=7 [1%]; Native Hawaiian or other Pacific Islander, n=2 [<1%]; race not reported, n=3 [<1%]; other race, n=4 [<1%]; Hispanic or Latinx, n=117 [22%]) randomly assigned to subcutaneous TV-46000 once monthly (n=183), TV-46000 once every 2 months (n=180), or placebo (n=181). Time to impending relapse was significantly prolonged by 5·0 times with TV-46000 once monthly (hazard ratio, 0·200 [95% CI 0·109-0·367]; p<0·0001) and by 2·7 times with TV-46000 once every 2 months (0·375 [0·227-0·618]; p<0·0001) versus placebo. Most frequently reported treatment-related adverse events (ie, ≥5% of patients in either TV-46000 group) that occurred more often in patients receiving TV-46000 (once monthly or once every 2 months) versus placebo were injection site nodules (7% for TV-46000 once monthly, 7% for TV-46000 once every 2 months, 3% for placebo), weight increased (4%, 6%, 2%, respectively), and extrapyramidal disorder (5%, 3%, 0% respectively). Serious adverse events were reported for eight (4%) patients in the TV-46000 once-monthly group, ten (6%) patients in the TV-46000 once-every-2-months group, and 14 (8%) patients in the placebo group. The safety profile of TV-46000 was consistent with other approved formulations of risperidone. No new safety signals were identified.

INTERPRETATION

In patients with schizophrenia, subcutaneous TV-46000 once monthly and once every 2 months significantly delayed impending relapse versus placebo. TV-46000 is an effective long-acting, subcutaneous, antipsychotic agent treatment option in adult patients with schizophrenia, with a favourable benefit-risk profile.

FUNDING

Teva Branded Pharmaceutical Products R&D.

Real-world effectiveness of fingolimod in patients with multiple sclerosis in Bulgaria

INTRODUCTION

Fingolimod, a sphingosine-1-phosphate receptor agonist used for the treatment of multiple sclerosis (MS). Our goal was to assess the impact of fingolimod on quality of life in patients with relapsing-remitting multiple sclerosis (RRMS) after 2 years of treatment in this real-world study.

PATIENTS AND METHODS

This was a 2-year, prospective, observational study conducted in Bulgaria in RRMS patients treated with fingolimod. Quality of life was assessed using the Bulgarian-language version of the MSQoL-54 scale. The primary endpoint was the change from baseline in the MSQoL-54 score after 2 years of treatment. Secondary endpoints included the change from baseline in the MSQoL-54 score after one year of treatment, furthermore the assessment of depression level using the Hamilton D-17 score.

RESULTS

A total of 87 eligible patients were included in the study with a mean age of 38.7 ± 8.45 years. The median Expanded Disability Status Scale (EDSS) score was 3.5 points. We found statistically significant improvement in 10 subscales at month 12 and in seven subscales at month 24. The mental health composite score increased from 64.0 ± 16.69 points to 67.5 ± 15.94 points at month 24 (p = 0.012). The physical health composite score increased from 61.7 ± 17.61 to 66.3 ± 16.70 (p = 0.001). Depression level measured by the HAM-D17 decreased significantly by month 12 and month 24. The EDSS score decreased or remained stable in more than half of the patients (61.6%). We detected better quality of life in patients with a lower EDSS score.

CONCLUSIONS

Quality of life scores and the depression level are improved in RRMS patients treated with fingolimod over 2 years in real-life setting.

Molecular Analysis of Dihydropteroate Synthase Gene Mutations in Pneumocystis jirovecii Isolates among Bulgarian Patients with Pneumocystis Pneumonia

Pneumocystis jirovecii pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the DHPS gene. This study aims to investigate the presence of DHPS gene mutations among P. jirovecii isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the P. jirovecii mitochondrial large subunit rRNA gene and further at the DHPS locus. P. jirovecii DNA was detected in 50 (15.34%) specimens. A 370 bp DHPS locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all (n = 21) P. jirovecii isolates showed DHPS genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by P. jirovecii mutants potentially resistant to sulfonamides are still rare events in Bulgaria. DHPS genotype 1 at codons 55 and 57 is the predominant P. jirovecii strain in the country.

[The brief characteristic of manpower potential in health care of Greece, Spain, Bulgaria]

The article presents brief descriptive review of manpower resources in health care of Greece, Spain and Bulgaria. It is noted that countries differ in redundancy of specialists at relative deficiency of general practitioners. The medical personnel of analyzed countries are characterized by aging, tendency to migration to other countries, deficiency of paramedical personnel and excess of required number of dentists that is especially pronounced in Bulgaria. Furthermore, accessibility of medical care is reduced by limits of number of patients per one physician established for specified time period in Greece. The salary level of physicians in these countries varies from minimal (Greece, Bulgaria) to maximal in Spain. At that, training of medical personnel is implemented according to Bologna system (bachelor course, magistracy, etc.) and is characterized by long period (4-5 years) of training physician for independent work.

PAs in the Bulgarian healthcare system

ABSTRACT

This article examines the importance of the physician associate/assistant (PA) profession in the healthcare system in Bulgaria. PAs in the country primarily work in emergency medicine and surgery, and are needed in other clinical settings, such as obstetrics and gynecology and psychiatric clinics, that are experiencing challenges because of physician shortages.

Assessment of beach macrolitter using unmanned aerial systems: A study along the Bulgarian Black Sea Coast

Over the years, the Black Sea has been impacted by the issue of marine litter, which poses ecological and health threats. A mid-term monitoring program initiated in 2018 assessed the abundance, density, and composition of beach litter (BL) on 40 frequently visited beaches. From 2018 to 2022, there was a significant increase in average abundance, rising by 261 %. Artificial polymer materials accounted for the majority (84 %) of the litter. Land-based sources dominated 77 % of the litter. The Clean Coast Index (CCI) categorized the beaches as "moderate" with an average value of 8.9 for the period between 2018 and 2022. However, the years 2021 and 2022, during the COVID-19 epidemic, were identified as the "dirtiest period" with 11 beaches classified as "extremely dirty" due to high domestic tourist pressure. The study demonstrates a successful combination of standard in situ visual assessment supported by unmanned aerial systems for beach litter surveys.

Indoor radon concentrations in kindergartens in three Bulgarian districts

This article examines the results of a study of radon concentrations in kindergartens in three districts of north-western Bulgaria. For the period from December 2019 to May 2020, passive radon measurements were accomplished in 1490 premises of 130 kindergartens. The highest arithmetic mean (AM) value of 219 Bq m-3 and geometric mean (GM) value of 156 Bq m-3 radon concentration were found in the state kindergartens of the Vratsa district. The radon values for the remaining two districts are as follows: Lovech-AM = 156 Bq m-3 and GM = 114 Bq m-3; Montana-AM = 125 Bq m-3 and GM = 88 Bq m-3. The effects of various factors on the radon concentration including district, year of building construction, presence of basement, place of premise, wall, and floor interior covering materials, and presence of a ventilation system were investigated. Factor Analysis was used to assess the combined effects of those factors on indoor radon concentration. The results revealed three combinations of the investigated factors: the first combined the district in which the kindergartens were located and the materials used for the floor of the premises, the second combined the year of construction of the building and the presence of a building foundation, and the third combined the rest of the investigated factors. It is concluded that a regional assessment of predictors of radon variability is needed. The walls in kindergartens should not be covered by gypsum, and floors should not be made from materials that can easily develop cracks such as terra cotta. The installation of a ventilation system reduces the radon concentrations in the premises, which is of particular importance in cases where the measured value is above the national reference levels.

Netherton syndrome in a Bulgarian patient : Presentation of a case and an update of therapeutic options

Comel-Netherton syndrome, or Netherton syndrome (NS), is a rare chronic genetic skin condition affecting the daily life of patients, which often results in poorly developed social skills and anxiety. Genetic predisposition plays a key role alongside the clinical findings, and clinicians must be aware of it as it can mimic other well-known skin conditions. Diagnosis is challenging both clinically and histologically. Clinically, it can mimic a severe form of atopic dermatitis, psoriasiform dermatitis overlapping with atopic dermatitis, or erythrokeratodermia variabilis. The difficulties in making histological diagnosis are similar, and it is often necessary to take several biopsies in order to clarify the diagnosis. Although retinoids are used for both psoriasis, erythrokeratodermia variabilis, and other congenital forms of keratodermia, the recommended treatment doses are different. This often results in poor treatment outcome. We present a 16-year-old patient previously diagnosed as erythrokeratodermia variabilis and treated with little to no improvement. Systemic therapy with acitretin 10 mg daily, local pimecrolimus 1%, emollients, and bilastine 20 mg once daily was initiated. Due to the limited application of retinoids and the difficulties in achieving permanent remission, modern medicine is faced with the challenge of seeking innovative therapeutic solutions. New hopes are placed on targeted or anti-cytokine therapy, based on inhibiting the inflammatory component of the disease. This article is mainly focused on innovative therapeutic options, including modern medications such as dupilumab, infliximab, secukinumab, anakinra, omalizumab, and others.

Blood pressure reduction in difficult-to-control patients and the effect of a nurse-led program in Bulgaria

Hypertension is a major contributor to cardiovascular morbidity and mortality. Although there has been significant improvement in blood pressure (BP) control during the last decades, it is still far from optimal. Several strategies for hypertension management have been proposed, and among all - nurse-led programs seem encouraging.

AIM

To evaluate the effect of a complex nurse program aiming to reduce BP in patients with uncontrolled hypertension.

PATIENTS AND METHODS

In a cardiologist's office, a trained nurse included patients with uncontrolled hypertension and newly referred patients with high BP in a program for hypertension management. It consisted of patient education, assessment of quality of life, lifestyle advice, medication improvement and adherence stimulation. All patients were followed for 6 months and their BP, lifestyle indicators, and quality of life measurements were recorded. Statistical analyses included two- and one sample t-tests, chi-square test, correlation and multivariate linear regression.

RESULTS

Overall, 47 patients, presenting with uncontrolled hypertension and with BP>140/90 mm Hg were included in this research. Their BP was reduced within 6 months by mean 30 /11 mm Hg and after 6 months, from 162/88 to 133/77 mm Hg. The drop of BP values was present at the first month with mean BP 140/82 mm Hg. Control of hypertension improved from 2% to 55% at the 1st month mark and to 79% at the 6th month, p<0.0001. The decrease in SBP was positively correlated to decrease in waist circumference, p = 0.47, p = 0.009. In multivariate linear regression analysis, the difference in BP was significantly related to self-assessment health scoring and marginally significant with renal impairment.

CONCLUSIONS

The development of a complex nurse-led program, tailored to patients with uncontrolled hypertension, leads to significant positive effect on BP decrease and improves hypertension control in primary care. This may be cost effective and improve BP control in low- to middle-income countries.

Anti-tumor necrosis factor therapy in Bulgarian pediatric patients with inflammatory bowel disease - an 8-year experience of a referral center

INTRODUCTION

Anti-tumor necrosis factor (anti-TNF) therapy has become a mainstay in the treatment of patients with inflammatory bowel disease over the past few decades.

Cholangioscopy-guided lithotripsy in the treatment of difficult bile ducts stones - Bulgarian and Egyptian experience

Introduction: Up to 10% of bile duct stones are deemed 'difficult' because they cannot be extracted using standard endoscopic techniques. In these situations, cholangioscopy allows for stone fragmentation under direct visual control.

The 32nd Annual Conference of ECOG, Albena, Bulgaria, September 7-9 2023, Abstracts

This meeting is the report of the European Childhood Obesity Group 32nd Annual Congress in Albena (Bulgaria), taking place from the 7th to the 9th of September 2023.

Essential Oil

Common tansy (Tanacetum vulgare L.) is a plant with medicinal properties that has traditionally been used in folk medicine for its anthelmintic, antispasmodic, and choleretic effects, for the treatment of diarrhea and digestive problems, and externally, as an insecticide in veterinary practices. In the current study, we investigated, for the first time, the chemical profile and antioxidant activity of essential oil from a wild population of T. vulgare L. growing in Bulgaria. Common tansy essential oil (EO), which is rich in bicyclic monoterpenes, was obtained using hydrodistillation and characterized by using gas chromatography-mass spectrometry (GC-MS). Thirty-seven compounds were identified in Bulgarian tansy EO. Among the major constituents were oxygenated monoterpenes, including compounds such as camphor (25.24%), trans-chrysantenyl acetate (18.35%), cis-verbenol (10.58%), thujone (6.06%), eucaliptol (5.99%), and α-campholenal (5.98%). The analysis results identified the essential oil from T. vulgare L. grown in the western Rhodope Mountains of Bulgaria as the camphor chemotype. Furthermore, its antioxidant activity was analyzed using the oxygen radical absorbance capacity (ORAC) method and was found to be 605.4 ± 49.3 µmol TE/mL. The essential oil was also tested for single-dose acute toxicity on Wistar rats and was found to be non-toxic by oral administration. The mean lethal dose by intraperitoneal administration was LD50 i.p. = 14.9 g/kg body weight. The results of the conducted study can serve as a basis for the evaluation and subsequent exploration of other pharmacotherapeutic effects of the essential oil obtained from the inflorescences of the Bulgarian species T. vulgare L.

Repetition velocity as a measure of loading intensity in the free weight and Smith machine Bulgarian split squat

This study investigated the grouped and individualized load-velocity profile (GLVP vs. ILVP) in Bulgarian split squat using Smith machine and free weight. Seventy five recreational male lifters completed two incremental loading tests of Bulgarian split squat. Mean velocity was measured by a linear-position transducer (GymAware). Linear regression equation was applied to construct the GLVP and ILVP. The agreement of predicted %1RM and measured %1RM was assessed by a combination of intraclass correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM) and Bland-Altman analysis. Acceptable validity was defined as ICC > 0.75, CV ≤ 10% and p ≥ 0.05 (a paired Wilcoxon signed-rank test). A very high level of inverse load-velocity relationships were demonstrated in Bulgarian split squat (r =  - 0.92) with free weights and a Smith machine. ILVP (ICC ≥ 0.98, CV ≤ 8.73%, p ≥ 0.56) was valid enough to predict the %1RM, but GLVP of both limbs revealed large CVs in free weights (CV: 15.4%,15.63%) and a Smith machine (CV: 11.24%, 12.25%). Cross-validation between the actual %1RM and predicted %1RM using free weights and a Smith machine ILVP was not acceptable (p ≤ 0.03, CV ≥ 14.07%). A very high level of inverse relationship were observed between %1RM and MV in Bulgarian split squat using free weights and a Smith machine, indicating individualized load velocity properties, and the ILVP showed high between-devices variability in both scenarios. Using velocity as a measure of loading intensity in Bulgarian split squat needs to consider the individualized load velocity properties, and difference between free weights and a Smith machine.

KRAS Mutation Status in Bulgarian Patients with Advanced and Metastatic Colorectal Cancer

RAS somatic variants are predictors of resistance to anti-EGFR therapy for colorectal cancer (CRC) and affect the outcome of the disease. Our study aimed to evaluate the frequency of RAS, with a focus on KRAS variants, and their association with tumor location and some clinicopathological characteristics in Bulgarian CRC patients. We prospectively investigated 236 patients with advanced and metastatic CRC. Genomic DNA was extracted from FFPE tumor tissue samples, and commercially available kits were used to detect RAS gene somatic mutations via real-time PCR. A total of 115 (48.73%) patients tested positive for RAS mutations, with 106 (44.92%) testing positive for KRAS mutations. The most common mutation in exon 2 was c.35G>T p.Gly12Val (32.56%). We did not find a significant difference in KRAS mutation frequency according to tumor location. However, patients with a mutation in exon 4 of KRAS were 3.23 times more likely to have a tumor in the rectum than in other locations (95% CI: 1.19-8.72, p = 0.021). Studying the link between tumor location and KRAS mutations in exon 4 is crucial for better characterizing CRC patients. Further research with larger cohorts, especially in rectal cancer patients, could provide valuable insights for patient follow-up and treatment selection.

[Brief description of the personnel potential of healthcare in Greece, Spain and Bulgaria]

The article presents a brief descriptive overview of the human resources of healthcare in Greece, Spain and Bulgaria. It is noted that they differ in the redundancy of specialist doctors with a relative shortage of general practitioners. The medical personnel of these countries are characterized by aging, a tendency to migrate to other countries, a shortage of secondary medical personnel, an excess of the required number of dentists, which is especially pronounced in Bulgaria. In addition, the availability of medical care and the limits on the number of patients for a certain time period with one doctor, established in Greece, reduce. The salary level of doctors in these countries varies from the minimum (Greece, Bulgaria) to the maximum in Spain. At the same time, the training of medical personnel is carried out according to the Bologna system (bachelor's degree, master's degree, etc.) and is characterized by a long period (4-5 years) of preparing a doctor for independent work.

[Brief description of the healthcare systems of Greece, Spain and Bulgaria]

The review of healthcare systems presented in the article notes the diversity of healthcare management in Greece, Spain, and Bulgaria. All these systems have more or less pronounced state subsystems with different centralization of management, the maximum level of which is represented in Bulgaria. Medical care is provided at several levels, while the provision of primary health care still requires improvement in Greece and Bulgaria. A fairly high percentage of GDP spent in these countries on healthcare does not prevent the co-financing of medical services at the expense of personal funds of citizens, including through informal payments. At the same time, in all three countries, the provision of medical care in hospitals still prevails over outpatient care.

What is the awareness of rare diseases among medical students? A survey in Bulgaria

BACKGROUND

Rare diseases (RDs) are life-threatening or chronically debilitating and offer a high level of complexity. The aim of this study is to assess medical students' knowledge and awareness of RDs as well as their perceptions of potential measures to boost training in RDs. The cross-sectional survey was conducted at the Medical University of Plovdiv, Bulgaria, in 2019. The questionnaire contained 12 questions, divided into three main categories: (1) sociodemographic profile; (2) knowledge and awareness of RDs; and (3) attitudes about potential measures to improve training in RDs.

RESULTS

A total of 1189 medical students completed the survey with an overall response rate of 56.4%. Only 13% of participants knew the correct definition of RDs, and a low overall level of awareness was found with regard to orphan drugs (20.3%) and genetic counselling and testing (0.5%). Respondents believed that society as a whole was largely unaware of RDs as a major public health issue. Students suggested elective courses, and invited lectures by RDs experts, and participation in research projects as the most preferred measures to improve undergraduate training.

CONCLUSIONS

It is crucial to address the gaps in medical students' knowledge and awareness of RDs. University curricula should consider incorporating different RDs training modalities. It is essential to encourage various stakeholders to play a more proactive role and to collaborate in these activities. Involvement of patient organisations and advocacy groups might enhance students' knowledge of the challenges faced by people with RDs. Not least, the media should be partners in this important endeavour as well.

BULGARIAN PATIENT WITH ATROPHODERMA OF PASINI AND PIERINI- DESCRIPTION OF A CASE AND SHORT UPDATE

Atrophoderma of Pasini and Pierini is a rare, considered benign, skin disease characterized by single or multiple asymptomatic atrophic plaques. Lesions can occur everywhere on the body with the trunk being the most often reported affected site. It appears in the second or third decade of life and affects mostly the female population, with male to female ratio of 1:6, commonly of white European descent. Different risk factors were described in the literature - genetic predisposition, infections with Epstein-Barr virus, varicella zoster and Borrelia burgdorferi, vaccinations, local trauma and more. Since the pandemic with COVID-19, skin manifestations after the viral infection with COVID-19 were reported. After a thorough search of the existing medical literature, we believe, we present the first case of a rapid progression of Atrophoderma of Pasini and Pierini after COVID-19 infection. Due to its similarity to morphea in some aspects, the condition is often misdiagnosed, and the proper treatment is often delayed. Sometimes the dilemma "Is it atrophoderma Pasini-Pierini or is it in fact morphea?" stays, but the exact histopathological verification and the "diagnostic clues" which can be used during the examination stage, are usually enough to diagnose the condition. We present a 63-year-old female with a rapid progression of atrophoderma of Pasini and Pierini after a COVID-19 infection. The lesion that she presented with was single, asymptomatic, with central hypopigmentation and slight atrophy, with a smooth, shiny surface and ivory color, and peripheral hyperpigmentation, measured 18x5cm, without the presence of perilesional erythema. The patient was initially diagnosed clinically with localized scleroderma (morphea) and treated with hydroxychloroquine 200 mg once daily for a 5-year period without improvement. Years later two biopsies from different lesional sites were taken, resulting in absence of sclerosis and dermal atrophy, but - reduction in the thickness of the dermis with fragmentation and hyalinization of collagen fibers forming a parallel orientation, dilated vascular vessels of small caliber and reduced number of skin appendages, confirming the diagnosis of atrophoderma Pasini-Pierini. The patient's therapy was switched to methotrexate with good therapeutic response. Often, the two conditions - morphea and atrophoderma of Pasini and Pierini can be mistaken due to its clinical similarity and sometimes coexistence. Therefore, we will shortly review the existing literature with key points on the similarities and differences.

Characteristics of patients with severe asthma in primary and secondary care settings considered eligible for biological therapy - the Bulgarian RECOGNISE study

INTRODUCTION

Asthma is a major non-communicable disease. It affects both children and adults, but is the most common chronic condition among the former. While inhaled controller drugs stabilize the disease in most asthma patients, there are a certain number of people who suffer from severe asthma, which requires treatment escalation. Oral corticosteroids are usually added, but they are associated with various side effects that may limit their application. The introduction of biologicals targeting inflammatory mediators has opened a new era of asthma treatment highlighting the importance of patient characterization.

Molecular and morphological characterization of Xylaria karsticola (Ascomycota) isolated from the fruiting body of Macrolepiota procera (Basidiomycota) from Bulgaria

The present study is the first to report Xylaria karsticola isolated from the basidiocarp of Macrolepiota procera (Basidiomycota), from Stara Planina Mountain, Bulgaria and second report for such species found in Europe. The fungal isolate was in vitro cultivated and the morphology was observed. It was primarily determined as a xylariaceous morphotype at the intragenus level, based on the evaluation of colony growth rate, color, and stromatic structure formation and was confirmed by unique conidiophores and conidia. The molecular identification of the isolate was performed by amplification of ITS1-5.8S-ITS2 region and the strain was identified as Xylaria karsticola with 97.57% of confidence. The obtained sequence was deposited in the GenBank database under the accession number MW996752 and in the National Bank of Industrial Microorganisms and Cell Cultures of Bulgaria under accession number NBIMCC 9097. The phylogenetic analysis of the isolate was also conducted by including 26 sequences obtained from different Xylaria isolates. Considering the phylogenetic data, X. karsticola NBIMCC 9097 was grouped along with other X. karsticola isolates, although the DNA sequence of the novel X. karsticola was rather distantly related to the other X. karsticola sequence data. The results were supported by the bootstrap analysis (100%) and indicated the different origin of the examined X. karsticola NBIMCC 9097.

Natural Mineral Water and Diuresis: A Systematic Review

The present systematic review is aimed at evaluating the diuretic effects determined according to the natural mineral water consumption on healthy individuals. This systematic review has been performed following the guidelines of the PRISMA (preferred reporting items for systematic reviews and meta-analyses) Statement, investigating PubMed, Scopus, Web of Science and Cochrane Library from inception to November 2022. Studies performed both on animals and on humans were considered. After screening, a total of 12 studies have been identified. Of these, 11 studies were performed in Italy and 1 in Bulgaria. The time range of publication is very wide, ranging from 1962 to 2019 for human studies and from 1967 to 2001 for animal studies. All the included studies found an increase in diuresis determined according to the consumption of natural mineral water, in some cases after just one administration of the tested water. However, the quality of the studies is not so high, especially for the research conducted many years ago. Thus, it would be desirable to carry out new clinical studies using more appropriate methodological approaches and more refined methods of statistical data processing.

Extraction, Structural Characterization, and In Vivo Anti-Inflammatory Effect of Alginate from Cystoseira crinita (Desf.) Borry Harvested in the Bulgarian Black Sea

The aim of this study was to identify the chemical composition and sequential structure of alginate isolated from C. crinita harvested in the Bulgarian Black Sea, as well as its effects in histamine-induced paw inflammation in rats. The serum levels of TNF-α, IL-1β, IL-6, and IL-10 in rats with systemic inflammation, and the levels of TNF-α in a model of acute peritonitis in rats were also investigated. The structural characterization of the polysaccharide was obtained by FTIR, SEC-MALS, and 1H NMR. The extracted alginate had an M/G ratio of 1.018, a molecular weight of 7.31 × 104 g/mol, and a polydispersity index of 1.38. C. crinita alginate in doses of 25 and 100 mg/kg showed well-defined anti-inflammatory activity in the model of paw edema. A significant decrease in serum levels of IL-1β was observed only in animals treated with C. crinita alginate in a dose of 25 mg/kg bw. The concentrations of TNF-α and IL-6 in serum were significantly reduced in rats treated with both doses of the polysaccharide, but no statistical significance was observed in the levels of the anti-inflammatory cytokine IL-10. A single dose of alginate did not significantly alter the levels of the pro-inflammatory cytokine TNF-α in the peritoneal fluid of rats with a model of peritonitis.

The essential oil composition of the endemic plant species Centaurea vandasii and chemotaxonomy of section Phalolepis (Asteraceae)

In the present study, the chemical composition of the essential oil from aerial parts of the endemic plant species, Centaurea vandasii Velen (sect. Phalolepis, Asteraceae), collected in its locus classicus in Rhodope Mts, Bulgaria, was evaluated by GC-MS. The main components of the oil were hexadecanoic acid (18.3%), tetradecanoic acid (13.8%), caryophyllene oxide (12.1%) and germacrene D (8.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Phalolepis, studied so far, was performed. HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analyses) were used in order to demonstrate chemotaxonomical variations in the composition of the essential oils.

Multidetector computed tomography angiography study of the renal arterial vasculature anatomy and its variations in a Bulgarian adult population

PURPOSE

Renal arterial anatomy has a great clinical importance during surgical and endovascular procedures. However, comprehensive data on renal arterial variations in the Bulgarian population has not yet been provided. The aim of this study was to conduct a detailed research about the normal anatomy and variations of the renal arteries in the Bulgarian population.

METHODS

Five hundred sixty-one patients underwent contrast-enhanced multidetector computed tomography scans for the period 2016-2021. The images were retrospectively reviewed. Number, branching pattern, origin level and course of the renal arteries were noted. Data were categorized on the basis of laterality, gender and symmetry.

RESULTS

Only 46.3% of the patients exhibited normal renal arterial anatomy. Variations were observed in 301 patients (53.7%). The most common variant was the presence of accessory renal arteries (ARA), discovered in 41.2% of the subjects. There was no significant difference based on gender and laterality (p > 0.05). Hilar ARA (72.6%) were significantly more common than polar ARA (p < 0.001). The most common origin location of the main renal arteries and ARA was the aorta, followed by the common iliac arteries. Early division was observed in 21.7% of the patients, significantly more common on the right. Precaval course was found in 0.5% of the right main renal arteries and in 30% of ARA and the difference was significant (p < 0.001).

CONCLUSION

These results show novel insight into the prevalence of renal arterial variations in the Bulgarian population. Anatomic renal vasculature variants are common therefore awareness is crucial for the success of surgical and interventional procedures.

Criminal insanity in Bulgaria and Norway: Analysing the prospect of a common approach

This article raises the question of the prospect of a common approach to mentally ill offenders in Europe, through a comparative discussion of the criminal insanity rules and systems in Norway and Bulgaria. The underlying motivation is to fill a gap in current legal research where the insanity discourse is still to a certain extent nationally oriented. Bulgaria is to date not represented at all in the international discussion of criminal insanity. Starting out from recognizing the different history, rules, culture and welfare of Norway and Bulgaria, the authors argue that these countries have a similar practical understanding of insanity and how it is associated with mental disorders as well as common challenges in their forensic and legal systems. These insights can provide a basis for further comparative explorations concerning a possible harmonization of insanity law in Europe.

How do parents refer to their children while playing? A cross-linguistic comparison of parental input to Bulgarian- and English-speaking children with ASD

Instances of person-reference, in the form of personal pronouns, names, or terms of endearment, are frequently used in child-directed speech. Examining this aspect of parental input is especially relevant to children with autism, who experience difficulties with person-reference. In this study, we compared the person-reference during parent-child interactions of Bulgarian (N=37) and English-speaking (N=37) parents of children with autism, who were matched on the language ability of their child. English-speaking parents used significantly more personal pronouns to refer to their children, while Bulgarian-speaking parents used the child's name more along with kinship terms. Furthermore, Bulgarian-speaking parents used significantly more different ways to refer to their child. These group differences were interpreted in the context of structural differences in the pronominal systems of Bulgarian and English, and in terms of culturally different discourse practices.

Back to the future: The advantage of studying key events in human evolution using a new high resolution radiocarbon method

Radiocarbon dating is the most widely applied dating method in archaeology, especially in human evolution studies, where it is used to determine the chronology of key events, such as the replacement of Neanderthals by modern humans in Europe. However, the method does not always provide precise and accurate enough ages to understand the important processes of human evolution. Here we review the newest method developments in radiocarbon dating ('Radiocarbon 3.0'), which can lead us to much better chronologies and understanding of the major events in recent human evolution. As an example, we apply these new methods to discuss the dating of the important Palaeolithic site of Bacho Kiro (Bulgaria).

Longitudinal Analysis of Sustainable Tourism Potential of the Black Sea Riparian States Bulgaria, Romania and Turkey

The three states that border the Black Sea benefit from an important potential for tourism and consider the development of this sector to be a major objective. Nonetheless, they face environmental risks. Tourism does not have a neutral impact on the ecosystem. We evaluated tourism sustainability for three states bordering the Black Sea, Bulgaria, Romania and Turkey. We used a longitudinal data analysis applied to five variables for the period between 2005 and 2020. The data were taken from the World Bank website. The results show that tourism receipts significantly influence the environment. For all three countries, the total receipts from international tourism are unsustainable, while the receipts for travel items are sustainable. Sustainability factors are different for each country. The international tourism expenditures for Bulgaria, the total receipts for Romania and the receipts for travel items for Turkey are sustainable. In Bulgaria, the receipts from international tourism contribute to higher greenhouse gas emissions, i.e., negative environmental impact. In Romania and Turkey, the number of arrivals has the same impact. No sustainable tourism model could be identified for the three countries. Tourism activity was found to be sustainable only due to the receipts for travel items, that is, indirectly, from tourism-related activities.

Treatment patterns, adherence to international guidelines, and financial mechanisms of the market access of advanced breast cancer therapy in Bulgaria

Introduction

Breast cancer is the most common type of cancer affecting women in Europe. Advanced breast cancer (ABC) poses a significant therapeutic challenge, and therefore, timely access to treatment is crucial. The aim of the present study was to evaluate the treatment patterns and patients' access to new therapies for ABC in Bulgaria.

Methods

We conducted a retrospective study in the period 2008-2021. Based on the European Medicines Agency (EMA) database, we analyzed a number of medicinal products with marketing authorization for ABC in the last 13 years. Time to market access was evaluated as the degree of availability, which is measured by the number of medicines that are available to patients (availability index, AI), and the average time elapsed between obtaining a marketing authorization and time to inclusion in the Positive Drug List. Data were analyzed through descriptive statistics via Microsoft Excel version 10.

Results

The average time to access was 564 days for targeted therapy. The availability and compliance index for chemotherapy and hormonal therapy in advanced breast cancer was 1, while the average AI for targeted therapy was 0.67. Patient access to targeted oncology therapy of ABC is above average for Europe and takes 1-2 years.

Conclusion

Faster access is more evident for biosimilars. National regulatory requirements for pricing and reimbursement have a major impact on market access.

Development of psychology in Bulgaria after the political changes in 1989

This article outlines the significant organizational and scientific changes that occurred in Bulgarian psychology after the fall of the totalitarian regime in 1989. These included the establishment of new university and research centers in psychology, the abolition of ideological censorship in psychology publications, free choice of research methodology and methods, free communication, and exchange of ideas with foreign psychologists, and the development of psychoanalytic practice and psychological services. The liberalization of the social conditions for the development of science, in general, made psychology a much sought-after science and practice. In this time of social transition, its authority grew significantly due to the fact that its calling was to study and solve, above all, the problems of the people, especially as they were faced with new social conditions. In the last 30 years, psychological science in Bulgaria has been significantly humanized. These changes allowed scientists to propose new methodological approaches not only to the study of the psyche, but also to the study of both Bulgarian and foreign history of psychology. Although in the last 30 years not all measures taken in the institutional management of the psychological science were positive, Bulgarian psychology was given a new opportunity to join the international scientific community.

The Balkan Wars in prof. Přecechtěl's memories

Professor Přecechtěl's memories of the Balkan Wars of 1912-1913 have various facets and encompass different impressions and phases of these events. They trace the preparations in Prague and the journey to Montenegro, the ancient city of Cetinje among the poor and primitive people, experiences in the Albanian environment plagued by diseases, and the war experienced in Bulgaria. Czech doctors enthusiastically aided their Slavic brethren in the Balkans, who fought for liberation and rights. Initially, they were received coolly and with reservation as the local population had no experience with Czech doctors. However, over time, the medical expeditions proved their worth. Albania presented many obstacles, including a shortage of medicines and suitable food. The army suffered from droughts and exhaustion, leading to high mortality rates and infections. Medical activities were carried out under difficult conditions, lacking hygiene and basic supplies. Despite all the difficulties, the doctors strove to provide help, and their work was invaluable. Memories of the Balkan War are filled with stories of scarcity, challenges, human suffering, and determination to aid and solidarity.

Frequency Distribution of CYP2C9 and VKORC1 Mutations among Bulgarian Patients and their Importance for Anticoagulant Therapy

BACKGROUND

Genetic polymorphisms of CYP2C9 and VKORC1 play a major role in pharmacokinetics and pharmacodynamics of coumarin anticoagulants. The purpose of our study was to assess the relative frequency of the above mutations in Bulgarian population in order to predict bleeding tendencies and precisely manage the anticoagulant therapy during the postoperative period after cardiac surgery with extracorporeal circulation.

METHODS

Genomic DNA samples from 200 Bulgarian patients subjected to cardiac surgery with extracorporeal circulation were analyzed for VKORC1 1639G>A and CYP2C9*2&*3 polymorphisms by real-time polymerase chain reaction (PCR), then allele frequencies of various genotypes were calculated by Hardy-Weinberg Equilibrium.

RESULTS

Median patients' age was 63.9 ± 10.8 years; 66.5% were male. Median BMI was 28.6 ± 5.4 kg/m2. Genotype distribution for CYP2C9 was *1/*1 - 51%, *1/*2 - 21%, *1/*3 - 13.5%, *2/*3 - 4%, *3/*3 - 2%, and *2/*2 - 1.5%. The calculated frequency of CYP2C9*1 allele was 74.25%, CYP2C9*2 allele was 13%, and CYP2C9*3 allele was 12.75%, and all allelic frequencies were in Hardy-Weinberg equilibrium (p-value = 0.358). The major VKORC1 genotype was G/A - 47%, followed by G/G - 35.5% and A/A - 17.5%). Based on Hardy-Weinberg Equilibrium, there was no significant difference between observed and expected frequencies (X - -3.779), presumably as a result of the homogeneity in the population.

CONCLUSIONS

Analysis of the data obtained in the course of the study suggested that identification of homozygous carriers of VKORC1-1639 G>A (rs9923231) in Bulgarians may be useful in developing recommendations for personalized therapy. On the contrary, homozygous carriers of CYP2C9*2 or *3, included only 4.5% of the studied patients, thus indicating that this group would benefit less from dosing algorithms. Our results demonstrated good agreement with the results obtained in other studies conducted in the Caucasian population.

Cuspidothrix Is the First Genetically Proved Anatoxin A Producer in Bulgarian Lakes and Reservoirs

The paper presents the first proof of planktonic cyanoprokaryote genus Cuspidothrix as an anatoxin A (ATX) producer in Bulgarian wetlands. The results from polymerase chain reaction (PCR) obtained from two summer sampling campaigns in 26 selected lakes and reservoirs demonstrated presence of the anaC gene, responsible for ATX production in 21 strains of the genus. They were found in three waterbodies sampled in 2018 (coastal lake Vaya, coastal reservoir Poroy, inland reservoir Sinyata Reka) and in four waterbodies sampled in 2019 (inland reservoirs Duvanli, Koprinka, Plachidol 2, Sinyata Reka). The detected genetic diversity generally corresponds to the observations conducted by conventional light microscopy, by which we distinguished three species of Cuspidothrix (Cuspidothrix issatschenkoi, Cuspidothrix elenkinii and Cuspidothrix tropicalis, the latter considered alien in the country). Eleven strains showed high similarity to two sequences of C. issatschenkoi available from the National Centre for Biotechnology Information (NCBI). Ten other strains assembled in a group, which-in lack of available from NCBI genetic sequences-were presumed related to C. tropicalis and C. elenkinii after comparison with the results from light microscopy. Cuspidothrix strains found in Bulgarian waterbodies showed high genetic similarity to those isolated and sequenced from Asia (Japan, China) and Northern Europe (Norway, Finland).

Circulating miRNA-16 in inflammatory bowel disease and some clinical correlations - a cohort study in Bulgarian patients

OBJECTIVE

The pathogenesis of the inflammatory bowel disease (IBD) includes chronic inflammation and altered immune reactions. There are several publications, reporting that micro ribonucleic acids (miRNAs) may serve as a diagnostic biomarker with a potential to assess inflammation severity and treatment response1,2 in IBD patients. The objective of the study is to assess and correlate the serum expression of circulating miR-16 in IBD patients with some clinical parameters, such as extent, activity and severity of the disease.

PATIENTS AND METHODS

70 IBD patients [35 with ulcerative colitis (UC) and 35 with Crohn's disease (CD)] were included in the study. Serum miR-16 expression in both IBD diseases was assessed using reverse transcription quantitative real time PCR (RT-qPCR). Circulating miR-16 levels were also correlated with disease extent, activity and severity indices [Crohn's Disease Activity Index (CDAI), Montreal classification, Partial Mayo score]. Serum expression of miR-16 in the 70 patients was also compared to miR-16 serum levels in 30 healthy control subjects.

RESULTS

The patients' group showed mean serum miR-16 expression of 3.07 for CD, 1.97 for UC and 1.61 for the control group of healthy subjects with a significant difference in the expression between groups. There is a significant correlation between increased serum expression of miR-16 and disease activity, extent and severity.

CONCLUSIONS

The increased miR-16 serum expression correlates with disease activity, intestinal localization of CD, stenotic and penetrating phenotype. MiR-16 could serve as a potential biomarker to assess inflammation.

Conditions and processes of precipitation of iron compounds upon discharge of high-mineralized artesian water from artesian borehole R-30, Staro Oryahovo, Bulgaria

The artesian borehole R-30-Staro Oryahovo with total depth of 1740 m gives waters of chlorine-sodium type with a mineralization of 31 g/L from formations of Paleogene age. These waters contain high concentrations of iron and because of this, intense precipitation of iron compounds takes place at and around the wellhead. To clarify the ongoing processes, samples of precipitates and overflow water were taken. It was shown that the predominant form of iron in the water before reaching the surface is Fe²⁺-85-90% and FeCl⁺-4-11%. The calculated saturation index for a number of Fe²⁺-containing minerals showed that hydroxides and sulfates of Fe²⁺ are the possible candidates for sources of iron in the water. The reductive dissolution of wide spread Fe³⁺-containing minerals (hematite, goethite) was assumed as a possible alternative process releasing Fe²⁺ into water. At the surface, due to the contacts with the atmospheric oxygen, the environment is sharply changed to oxidizing one thus forming a geochemical barrier and causing mass precipitation of Fe³⁺ oxides. Simultaneous Fe²⁺ oxidation, hydrolysis of Fe³⁺ and co-precipitation with silica and other components are assumed as the major processes causing the formation of low-crystalline Si-containing ferrihydrite or ferrihydrite-like phase. After formation, the precipitated gels due to the processes of aging and continued interaction with the outflowing water have suffered the further change including the formation of goethite. It was shown that due to the intensive precipitation processes, the iron migration to the surface is limited to a very small area and does not affect adjacent agricultural territories with Fe.

1887": The return of the manuscript in Russia

The previous report partially brought to light history of publishing of "The letters of S. P. Botkin from Bulgaria 1877". The original letters were abroad for many years and they were returned to the USSR in 1974 by grandchildren of S. P. Botkin, S. P. Chekhov and D. P. Chekhov, who resided in France. The circumstances of handing over of the letters to the N. A. Semashko Institute of Health Organization and Social Hygiene are presented. The letters have not been republished for 130 years, but their historical, moral and educational significance remains actual and nowadays. The modern edition of the complete manuscript, along with introductory article and detailed scientific commentary, will become a significant contribution to representation of biography of S.P Botkin, to supplementation of written sources about the Russian-Turkish war of 1877-1878, and to comprehension of centuries-old Middle Eastern geopolitics of Russia.

Reporting adverse events of COVID-19 vaccines: The case of Bulgaria

As a member state of the European Union, where vaccines against COVID-19 are available and affordable, Bulgaria reports the lowest immunization coverage and the most pronounced vaccine distrust. The present study aimed to assess the self-reported adverse reactions following COVID-19 vaccination as a possible tool to increase the trust in vaccines. A cross-sectional survey-based study, covering 761 vaccinated respondents, was conducted in Plovdiv (469 with an mRNA vaccine and 292 with an adenoviral vector vaccine). Descriptive statistics parametric and non-parametric methods were applied. Statistical significance was set at p<0.05. The median age of the respondents was 42 years, females (72.5%). At least one adverse reaction was reported in 89.9% of those immunized with mRNA vaccine and 93.8% in the adenoviral vector vaccine group (p>0.05). They were mild to moderate and resolved within several days. The levels of local reactions were comparable: 91.7% in those who received mRNA and 89.7% in those who received an adenoviral vector vaccine (p = 0.366). The most common types of systemic reactions were fatigue, headache, and muscle pains. An association was found between the systemic reactions and the type of vaccine administered: 59.7% in mRNA recipients and 89.4% in adenoviral vector vaccinees (p<0.001). None of the registered systemic reactions required medical attention. There were 3 reports of generalized urticaria after an mRNA and 2 after an adenoviral vector vaccine. The reported reactions are relatively high but expected and no adverse events have been reported that are not listed in the official Summary of Product Characteristics.