Search

Objective: There are numerous publications on the parameters of conventional medications, which contribute to their cariogenic and erosive potential. Little is known about the homeopathic remedies (HR) and the changes in the oral cavity they lead to, especially during childhood.

Structural changes in rural areas are a subject of widespread discussion. During the transition to a market economy, Bulgarian agriculture underwent serious reforms, and after the accession to the EU, the transformations of the sector became even more significant. Political and socio-economic changes have an impact on agricultural production, organisational structure, and market performance. These processes have played an essential role in the development of rural areas. The aim of the study is based on an analysis of structural changes in Bulgarian agriculture, to outline their impact on the models of transformation of rural areas and make recommendations for sustainable development. Significant changes are observed during the analysed period. The agricultural sector remains polarised and dominated by several significant sub-sectors – cereals and oilseeds. The Common Agricultural Policy (CAP) does not contribute to balanced and sustainable development and deepens disparities. During the new programming period, the opportunities for modelling the CAP are significant and vary considerably. A new conceptual framework needs to be implemented in Bulgaria - the local model related to regional specifics can solve some of the challenges.

Actinobacillus pleuropneumoniae (App) is the etiological agent of porcine pleuropneumonia. The purpose of the study was to present a serological report on App prevalence among pigs in industrial farms in Bulgaria. Seventy-two pigs from four industrial farms in four districts of Bulgaria - Eastern Bulgaria (Razgrad and Yambol districts) and Western Bulgaria (Lovech and Sofia districts) were included. Animals were divided in two age groups: weaners and fattening pigs. A commercial enzyme-linked immunosorbent assay (ELISA, INgezim APP MIX, Eurofins Ingenasa, Madrid, Spain) for the detection of antibodies against App parasuis in porcine serum was used. Microtitr? plate was coated with App antigen of the serovars 1, 2, 9 and 11. Positive results for anti-App antibodies were detected in 32 (44.4%) of all 72 tested sera. The overall seropositivity in weaners and fattening pigs was 22.2% (8/36), and 66.7% (24/36), respectively. The highest App seropositivity in pigs was found in Eastern Bulgaria ? 61.1% (22/36; P<0.001) in comparison to App seropositivity in Western Bulgaria - 27.8% (10/36; P=0.137). This study on anti-App prevalence among pigs in Bulgaria gives new insights on App epidemiology in our country. [ABSTRACT FROM AUTHOR]

The development of rural regions and rural disparities are the main issues in the European Union regional policy. The topic continues to be an object of serious discussion among policymakers and scientist. Agriculture plays an important role in rural areas and contributes to generating employment and income. In the past decades, the CAP is reforming and changing to address the challenges in the EU rural regions. The aim of the study is based on the socio-economic analysis of the rural regions in Bulgaria to formulate opportunities for more balanced and sustainable development. The paper observes possibilities and prospects for the rural areas in Bulgaria in the context of the CAP post-2020. The study reveals that depopulation and marginalization of rural regions remain major issues in Bulgaria. Therefore, the implementation of the territorial and local model should dominate in Pillar II for the 2014-2020 programming period. These approaches could stimulate transformations and transition to sustainable regional development. In order to maximize the potential of the Pillar II funding, the national regional policy also should be reviewed. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the healing and prophylactic effect of drying-off antibiotic therapy using the selective and non-selective approach of administration of the antibiotics. First experimental group at the start of the dry period were treated non-selectively (all halves) intracisternally with antibiotics. In the second group, we only treated those halves that were diagnosed with subclinical mastitis. The control group of 9 goats was not treated. The number of somatic cells in treated groups after birth decreased from 2586 x 10³/ mL to 560 x 10³/mL in the first group and from 1978 x 10³/mL to 526 x 10³/mL in the second. Post partum, 10% of the halves were found to have subclinical mastitis. A healing effect was achieved in 25% (n=5) milk halves. New intramammary infections developed during the dry period also occurred in 5% (n=1) of the milk halves. In the second post-partum study, subclinical mastitis was observed only in 5% (n=1). Healing was achieved in 30% (n = 6) and the new intramammary infections (NIMIs) were 10% (n=2). In the control group, healing was only observed in 5% (n=1) and NIMI were 27.78% (n=5). The application of both treatment approaches, results in reduction in prevalence and manifestation of mastitis, as well as reduction of somatic cells in milk after kidding. The selective treatment method may be preferred, in order to reduce the cost of medications in conducting treatment and prophylaxis programs. [ABSTRACT FROM AUTHOR]

Aim: The overview of the interdependence of the immune system and the system metabolism. Regulation of metabolism is immunomodulatory, and targeting key cellular metabolic enzymes impacts T-cell development, altering the immune functions. Background: The diet, gastrointestinal microbiota and the balanced function of liver, adipose and muscle tissues underlie the immune ecology. Chronic inflammation (macrophage, TH1, and TH17 T-cell infiltration) associates with obesity, and the development of metabolic syndrome, cardiovascular diseases, type 2 diabetes, IBD and intestinal malignancies. While naive T-cells use beta-oxidation, TCA cycle, and mitochondrial respiration to produce ATP, activated T-cells, similarly to cancer cells, employ the Warburg's effect to power their function. The development of T-cells depends on key metabolic regulators, like mTORC1 (TH1 and TH17 T-cells) and mTORC2 (TH2 T-cells). Inhibition of HIF1-alpha (critical for TH17 T-cells) results in the development of FOXP3+ Treg T-cells, improving autoimmune disorders. Metabolic flexibility of normal cells underlines the successful treatment of neoplastic, autoimmune and hyper-sensitivity disorders. Conclusions: The immune system influences the system metabolism, and depends on the function of adipose tissue, muscles, liver, pancreas, lungs and gastro-intestinal tract. Diet and pharmacological regulation of T-cell metabolic activity influence immune function during autoimmunity, infections, and vaccinations. [ABSTRACT FROM AUTHOR]

As Bulgaria transitions away from Global Fund grant, robust estimates of the comparative impact of the various response strategies under consideration are needed to ensure sustained effectiveness of the tuberculosis (TB) programme. We tailored an established mathematical model for TB control to the epidemic in Bulgaria to project the likely outcomes of seven intervention scenarios. Under existing programmatic conditions projected forward, the country’s targets for achieving TB elimination in the coming decades will not be achieved. No interventions under consideration were predicted to accelerate the baseline projected reduction in epidemiological indicators significantly. Discontinuation of the ‘Open Doors’ program and activities of non-governmental organisations would result in a marked exacerbation of the epidemic (increasing incidence in 2035 by 6–8% relative to baseline conditions projected forward). Changing to a short course regimen for multidrug-resistant TB (MDR-TB) would substantially decrease MDR-TB mortality (by 21.6% in 2035 relative to baseline conditions projected forward). Changing to ambulatory care for eligible patients would not affect TB burden but would be markedly cost-saving. In conclusion, Bulgaria faces important challenges in transitioning to a primarily domestically-financed TB programme. The country should consider maintaining currently effective programs and shifting towards ambulatory care to ensure program sustainability. [ABSTRACT FROM AUTHOR]

Agriculture is an important sector in Bulgaria, especially in the rural areas where it is considered an important source of income and employment. Bulgarian agriculture has changed substantially over the past ten years, which has led to a transformation in production, farm, organizational and sectorial structures. The aim of the paper is to observe the regional differences in Bulgarian farm structure and outline main prospects for the next programming period, 2023-2027. The survey reveals a significant decline in the number of holdings in parallel with the decreased role of small farms. By contrast, the importance of large holdings is increasing. There are different patterns of agricultural transformation in the regions of Bulgaria. While large extensive producers dominate North Bulgaria, there is more balanced agricultural development in the South part of the country. The new CAP 2023-2027 is directed to more ambitious objectives related to climate, innovations and convergence. The subsidiarity principles could help Bulgaria to overcome some of these challenges if the agricultural policy is better targeted and oriented towards intensive sectors and more balanced and sustainable rural development. [ABSTRACT FROM AUTHOR]

We focus on black branes and toroidal black holes in N = 2 gauged supergravities that asymptote to AdS4, and derive formulas for the mass and central charge densities. We derive the corresponding BPS bound from the superalgebra of the asymptotic vacuum and illustrate our procedure with explicit examples of genuine black brane solutions with non-trivial scalars. [ABSTRACT FROM AUTHOR]

A breeding program, aimed at utilizing chemical mutagenesis and mutation breeding for induction of additional genetic variation in well-known elite maize (Zea mays L.) lines and hybrids, has been conducted in Bulgaria since 1973. The phenotypic variation created by chemically induced mutagenesis included important quantitative traits, such as grain yield, high protein content, reduced flowering time, changes in grain type, improved general (GCA) and specific combining ability (SCA) as well as improved abiotic stress tolerance. Twelve mutant lines obtained by chemical mutagenesis, followed by recurrent reciprocal mutation breeding (RRMB), and their initial lines Oh43, Oh40b, C103, B37, and a Pioneer brand hybrid 3737, were assessed for the induced genetic variability using 18 SSR markers. The mutant inbred lines, chosen because of their improved GCA and SCA for grain yield and proven predominance in Bulgarian breeding programs, showed shifts in their flowering time as compared with the initial inbreds. The SSR markers discriminated between the initial classical breeding inbred lines and the mutant inbreds that resulted from them. The level of the genetic diversity in the population of mutant inbreds with improved agronomic characteristics (0.651) was higher than that of classical inbreds (0.608). This indicates that chemical mutagenesis is a valuable tool for creating genetic variation in modern maize breeding programs for yield improvement and stress tolerance. [ABSTRACT FROM PUBLISHER]

Direct payments are the main component of the Common Agricultural Policy (CAP). They form approximately 76% of CAP budget in the programming period 2014-2020. The main purpose of the study is to outline the opportunities and challenges for Bulgarian agriculture, based on the analysis of direct payments distribution. The Lorenz curve, as the most widely used measure of inequality, is applied in the paper to surveying the disparities in the direct payments distribution. The results of the analysis show highly uneven distribution of the direct support across Bulgarian farms. The Lorenz curve indicates that payments are accumulated mainly in the larger-scale farms, thereby generating problems for small holdings and structural imbalances. The allocation of EU funds has impacted on the level of investments, productivity and economic efficiency of Bulgarian agriculture. [ABSTRACT FROM AUTHOR]

A case of Trichuris ovis infection in a lamb is presented. In June 2012 a herd of 12 infected with T. ovis lambs in Brestnik (Southern Bulgaria) were discovered. A diarrhea and loss in body weight in 2 lambs have been observed. Despite antibiotic treatment one of the animals died. Parasitological examination was done. During necropsy of the gastro-intestinal tract, adult worms in the caecum were found. Standart staining and immunohistochemistry were performed to detect the cell population in the affected areas of the caecum. [ABSTRACT FROM AUTHOR]

Introduction: Clinical research increasingly recognizes the role and value of patient-centric data incorporation in trial design, aiming for more relevant, feasible, and engaging studies for participating patients. Despite recognition, research on analytical models regarding qualitative patient data analysis has been insufficient., Aim: This pilot study aims to explore and demonstrate the analytical framework of the "patient feasibility" concept-a novel approach for integrating patient-centric data into clinical trial design using psychometric latent class analysis (LCA) and interval response theory (IRT) models., Methods: A qualitative survey was designed to capture the diverse experiences and attitudes of patients in an oncological indication. Results were subjected to content analysis and categorization as a preparatory phase of the study. The analytical phase further employed LCA and hybrid IRT models to discern distinct patient subgroups and characteristics related to patient feasibility., Results: LCA identified three latent classes each with distinct characteristics pertaining to a latent trait defined as patient feasibility. Covariate analyses further highlighted subgroup behaviors. In addition, IRT analyses using the two-parameter logistic model, generalized partial credit model, and nominal response model highlighted further distinct characteristics of the studied group. The results provided insights into perceived treatment challenges, logistic challenges, and limiting factors regarding the standard of care therapy and clinical trial attitudes., Competing Interests: MK were employed by Boehringer Ingelheim International GmbH. BS was employed by Boehringer Ingelheim SComm. MT, KH, and TM were employed by FindMeCure Ltd., (© 2024 Klüglich, Santy, Tanev, Hristov and Mincheva.)

Objective: To investigate the influence of citric acid on the osteogenic and angiogenic potential of stem cells from apical papillae (SCAPs)., Materials and Methods: Stem cells from apical papillae were isolated from freshly extracted third permanent molars. These cells were treated with 20 and 100 μM citric acid. Alizarin red staining was used to evaluate mineral deposition. The secreted levels of vascular endothelial growth factor (VEGF) were assessed by ELISA on days 18, 24 and 28. Immunofluorescence analysis was performed to assess the expression of surface markers after exposure to 20 and 100 μM citric acid., Results: Different mineralisation patterns were observed. Supplemented with citric acid, media showed more diffuse and less dense crystals. On day 18, most VEGF was secreted from the cells with no added citric acid. On day 24, there was a significant increase (p < 0.05) in the levels of VEGF secreted from cells treated with 20 μM citric acid. On day 28, cells from the control group did not secrete VEGF. There was a reduction in the levels of VEGF secreted by cells treated with 20 μM citric acid and a significant increase in the cells exposed to 100 μM citric acid (p < 0.05)., Conclusion: Citric acid can promote the differentiation of SCAPs and angiogenesis.

This study aimed to characterize the anatomical and physiological features of pits and fissures in primary and permanent molars by microtomographic (micro-CT) examination and three-dimensional (3D) printing. The occlusal surfaces of 84 primary molars and 60 permanent third molars were examined. The samples were scanned with micro-CT and the occlusal surface separated. The areas of the crown, its occlusal part, and fissures and pits were calculated. Digital impression of the occlusal surface was created and 3D printed. The frequency of different fissure types was determined by direct observation. Data were subjected to statistical analysis using Mann-Whitney U Test and chi-square test ( p < 0.05). There was statistically significant difference between the ratio of occlusal surface and the crown area for the molars in primary and permanent dentitions (24.78% and 28.85% respectively, p < 0.05). In terms of the percentage ratio of the fissure area to the occlusal surface (24.24% and 22.30%) and the fissure area to the crown (6.02% and 6.52%), no significant difference was observed ( p > 0.05). V-shaped fissures were predominant in both primary and permanent teeth, with a higher occurrence in primary dentition (59.48%, p < 0.05). Permanent molars exhibited a higher prevalence of I-type and U-type fissure configurations compared to primary molars ( p < 0.05), with I-type fissures being the least common in primary molars. In both dentitions there was no statistically significant difference in the prevalence of IK-configuration ( p > 0.05). The fissure depth was significantly greater in permanent molars than primary molars ( p < 0.05). In conclusion, this study revealed remarkable diversity in fissure morphology among primary and permanent molars., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

The endodontic treatment of immature permanent teeth with necrotic pulp is a significant clinical challenge. The success of regenerative endodontic procedure is highly dependent on disinfection of the root canal and an accurate anatomical knowledge of the root canal. The aim of this study was to use micro-computed tomography (micro-CT) analysis to investigate the configuration of root canals in the upper permanent third maxillary molars with incomplete root development in their coronal, apical and middle third portions. Thirty immature third permanent maxillary molars were scanned using a micro-CT system. Then, we measured the diameters and areas of the root canal in the coronal, middle and apical third of the roots. The ratio between the long and short diameter of each root canal was then calculated and the canals were divided into several groups: round, oval, long oval, flat and irregular. The round configuration was not observed in the distobuccal and mesiobuccal roots in any of their anatomical regions. Oval and long oval canals predominated in the distobuccal root. The greatest variations were observed in the mesiobuccal root, with the ribbon-shaped canal predominating in the middle region and an irregular shape in the apical region. In the coronal region of the palatal canal, the round configuration predominated; in the middle third, we observed an almost equivalent distribution between round and oval configurations; apically, the oval shape predominated. In conclusion, we observed significant complexity and variation in the morphology and configuration of root canals in immature permanent molars, thus generating additional obstacles for the success of regenerative endodontics., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

Introduction: The traditional treatment of immature permanent teeth with necrotic pulp involves creating an apical barrier by using calcium hydroxide or an MTA plug for an extended period of time. A novel therapeutic approach called regenerative endodontic procedures (REP) is used to allow root development to continue., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The aim of the present study was to determine the parameters characterising the blood flow velocity in the fetal heart and aorta in goats by Doppler ultrasonography. Twenty-four Bulgarian White milk goats, aged 4-6 years, weighing 45-51 kg were used in the study. Doppler ultrasound measurements of the blood flow velocity in fetal heart were done at the end of first, second and third trimesters of pregnancy, and in the fetal aorta - at the end of the second and third trimesters of pregnancy. Ultrasound investigations were carried out by transabdominal approach with linear and convex transducers, with frequency 8.0 MHz. Blood flow parameters that included maximum and minimum systolic velocity, end-diastolic velocity, pulsatility index, resistance index and systolic/diastolic ratio were measured by spectral Doppler ultrasonography. The results showed that the highest maximum systolic velocity in the fetal heart was observed at the end of the first pregnancy trimester. Statistically significantly (p < 0.05) lower values of this parameter were registered in the second and third pregnancy trimesters. A similar tendency was observed for minimum systolic velocity, end-diastolic velocity and systolic/diastolic ratio. The pulsatility index and resistance index had similar values for the three studied periods. Examination of the fetal aorta showed statistically significant differences (p < 0.05) of minimum systolic velocity, end-diastolic velocity, pulsatility and resistance index in the third, compared with the second trimester of pregnancy. The analysis of the results suggested that Doppler ultrasonography can be used to monitor fetal blood flow changes during the various stages of pregnancy., (© 2021 The Authors Veterinary Medicine and Science Published by John Wiley & Sons Ltd.)

Introduction: Dental operating microscopes (DOM) enable dentists to examine, with the aid of magnification and photodocumentation in clinical conditions, the occlusal anatomy of newly erupted permanent molars and to detect any early carious lesions more precisely., Aim: To determine the advantages of magnifying technology in detecting early occlusal carious lesions in newly erupted permanent first molars., Materials and Methods: We examined 176 first molars of 44 children divided into two age groups: 7-8 and 9-10 years. The surfaces of each of the teeth were examined after they were cleaned with a brush without paste. The diagnoses were first made using only illumination and a clinical examination. These were followed by a visual examination of the occlusal surface using a DOM at ×8 magnification. A photo of the occlusal surface was then taken with a camera at the respective magnification for the purposes of photodocumentation., Results: This study demonstrated that dental operating microscopes increased by 7% the rate of successful detection of early caries lesions on the occlusal surfaces. There was also a significant increase of the number of diagnosed cavitated caries in the dentine in comparison with those detected with naked eye. Using DOMs in pediatric dentistry facilitates the more detailed and precise diagnosing of early stage carious lesions and/or cavitations in the fissures., Conclusion: The use of a DOM facilitates differential diagnosing between deep fissures and early carious lesions, which is a key point in the assessment of occlusal surfaces of newly erupted permanent molars, necessary for their preventative sealing and micro-invasive treatment., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

We study four-derivative corrections to four-dimensional N=2 minimal gauged supergravity controlled by two real constants. The solutions of the equations of motion in the two-derivative theory are not modified by the higher-derivative corrections. We use this to derive a general formula for the regularized on-shell action for any asymptotically locally AdS&#95;{4} solution of the theory and show how the higher-derivative corrections affect black hole thermodynamic quantities in a universal way. We employ our results in the context of holography to derive explicit expressions for the subleading corrections in the large N expansion of supersymmetric partition functions on various compact manifolds for a large class of three-dimensional SCFTs.

Objective: This study piloted a European technical protocol for conducting chronic hepatitis C prevalence surveys in the general population. The pilot study took place in the Bulgarian city of Stara Zagora in 2018, and results of setting up, conducting and evaluating the survey are presented., Results: A probability-based sample of the general adult population was drawn from the local population registry, stratified by age and sex. A sample size of 999 was calculated, and accounting for 50% non-response, 1998 registered invitation letters were sent. Venous blood samples and questionnaire data were collected by the Regional Health Inspectorate in Stara Zagora. Blood samples were tested for anti-HCV, and if reactive for RNA. 252 (21.6%) of the participants were included in the study. Mean age and sex distribution differed between the participants (55.9 years, 60.3% females) and the total sample (48.9 years, 53.4%). The weighted chronic HCV prevalence among participants was 0.9% [95% CI 0.2-4.2%]. The approach of only sending registered letters contributed to a low response rate, and more efforts are needed to reduce non-response, especially among men and younger age groups. Results of the evaluation were integrated in the final technical protocol.

Introduction: The full decontamination and disinfection of the root canal system is essential for the success of regenerative endodontic procedures. The current literature does not have information regarding mechanical cleaning of immature teeth with contemporary endodontic instuments., Aim: To compare the thickness and volume of the dentin removed from the roots of immature teeth after endodontic preparation using XP-endo Finisher, GentleFile Brush and a standard H-file scraping technique through micro-computed tomography., Methods: The study included 51 immature permanent molars. Endodontic access was prepared and without performing preliminary extirpation of the pulp, the teeth were divided into three groups. The first group of teeth were instrumented for two minutes with XP-endo Finisher, the second - two minutes with Gentlefile Brush, in the third group the root canals walls were scraped with a No. 40 H-file. The thickness and the volume of the removed dentin was assessed using micro-CT imaging before and after the use of the instruments., Results: There is no statistically significant difference in the mean values of thickness of dentin removed between the teeth, prepared with XP-endo finisher and Gentlefile Brush. When comparing the mean values of volume of dentin removed between the separate groups, a statistically significant difference was discovered for every compared pair with the highest volume of removed dentin in the group prepared with a hand instrument., Conclusion: The endodontic systems tested when used in immature permanent teeth remove significantly less quantity of hard dental structures compared to a hand file for scraping the root canal., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: The study of histopathological changes caused by influenza A (H5N8) viral infection in bird species is essential for the understanding of their role in the spread of this highly infectious virus. However, there are few such studies under natural conditions in minor gallinaceous species. This article describes the pathomorphological findings in Colchis pheasants infected naturally with H5N8 during an epizootic outbreak in Bulgaria., Material and Methods: Samples of internal organs of 10 carcasses were collected for histopathological and immunohistochemical evaluation, virus isolation and identification, and nucleic acid detection., Results: Consistent macroscopic findings were lesions affecting the intestine, heart, lung, and pancreas. Congestion and mononuclear infiltrate were common findings in the small intestine, as were necrosis and lymphoid clusters in the lamina propria of the caeca. Congestion with small focal necrosis and gliosis with multifocal nonpurulent encephalitis were observed in the brain. Myocardial interstitial oedema and degenerative necrobiotic processes were also detected. Immunohistological analysis confirmed systemic infection and revealed influenza virus nucleoprotein in all analysed organs., Conclusion: Variable necrosis was observed in the brain, liver, trachea, heart, small intestine, and caeca. Viral antigen was commonly found in the brain, heart, lung and trachea. Contact with migrating waterfowls was suspected as a reason for the outbreak., Competing Interests: Conflict of Interest Conflict of Interests Statement: The authors declare that there is no conflict of interests regarding the publication of this article., (© 2019 G.M. Stoimenov et al. published by Sciendo.)

We compared membrane permeabilization by nanosecond pulsed electric field (nsPEF) in HEK293 cells with and without assembled CaV1.3 L-type voltage-gated calcium channel (VGCC). Individual cells were subjected to one 300-ns pulse at 0 (sham exposure); 1.4; 1.8; or 2.3 kV/cm, and membrane permeabilization was evaluated by measuring whole-cell currents and by optical monitoring of cytosolic Ca 2+ . nsPEF had either no effect (0 and 1.4 kV/cm), or caused a lasting (>80 s) increase in the membrane conductance in about 50% of cells (1.8 kV/cm), or in all cells (2.3 kV/cm). The conductance pathway opened by nsPEF showed strong inward rectification, with maximum conductance increase for the inward current at the most negative membrane potentials. Although these potentials were below the depolarization threshold for VGCC activation, the increase in conductance in cells which expressed VGCC (VGCC+ cells) was about twofold greater than in cells which did not (VGCC- cells). Among VGCC+ cells, the nsPEF-induced increase in membrane conductance showed a positive correlation with the amplitude of VGCC current measured in the same cells prior to nsPEF exposure. These findings demonstrate that the expression of VGCC makes cells more susceptible to membrane permeabilization by nsPEF. Time-lapse imaging of nsPEF-induced Ca 2+ transients confirmed permeabilization by a single 300-ns pulse at 1.8 or 2.3 kV/cm, but not at 1.4 kV/cm, and the transients were expectedly larger in VGCC+ cells. However, it remains to be established whether larger transients reflected additional Ca 2+ entry through VGCC, or were a result of more severe electropermeabilization of VGCC+ cells., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In the present study, we investigated both the age- and heat exposure-related redox changes of blood plasma by analyzing GSH, thiol status and carbonyl groups. Our results clearly indicated that the plasma redox balance shifted toward oxidation during both aging and acute heat exposure. To further confirm this age- and heat exposure-related redox shift, we quantified the changes in thiol content. The total thiol level was found to be significantly decreased in the aged group. A similar pattern can be explained by low levels of serum GSH in old rats compared to young rats. The significance of the present study are the data showing increased oxidative stress in plasma during aging, attributed to a decrease in major antioxidant components in serum. OTC treatment, in relation to C=O regarded as a marker of oxidative damage was probably much more effective in increasing of GSH synthesis than in prevention of protein oxidation.

T cells orchestrate the adaptive immune response, making them targets for immunotherapy. Although immunosuppressive therapies prevent disease progression, they also leave patients susceptible to opportunistic infections. To identify novel drug targets, we established a logical model describing T-cell receptor (TCR) signaling. However, to have a model that is able to predict new therapeutic approaches, the current drug targets must be included. Therefore, as a next step we generated the interleukin-2 receptor (IL-2R) signaling network and developed a tool to merge logical models. For IL-2R signaling, we show that STAT activation is independent of both Src- and PI3-kinases, while ERK activation depends upon both kinases and additionally requires novel PKCs. In addition, our merged model correctly predicted TCR-induced STAT activation. The combined network also allows information transfer from one receptor to add detail to another, thereby predicting that LAT mediates JNK activation in IL-2R signaling. In summary, the merged model not only enables us to unravel potential cross-talk, but it also suggests new experimental designs and provides a critical step towards designing strategies to reprogram T cells.

The hypothesis is that the ghrelin signal pathway consists of new participants including a local second mediator in human mesenteric arteries. The contractile force of isometric artery preparations was measured using a wire-myograph. Whole-cell patch clamp experiments were performed on freshly isolated single smooth muscle cells from the same tissue. After the addition of ghrelin (100 nmol) the outward potassium currents conducted through iberiotoxin-sensitive calcium-activated potassium channels with a large conductance were almost entirely abolished. The effect of ghrelin on potassium currents was insensitive to selective inhibitors of cAMP-dependent protein kinase and soluble guanylate cyclase, but was eliminated in the presence of des-octanoyl ghrelin and O-(octahydro-4,7-methano-1H-inden-5-yl) carbonopotassium dithioate (D-609). Ghrelin dose-dependently increased the force of contraction of native, endothelium-denuded and mostly of endothelium-denuded and treated with tetrodotoxin human mesenteric arteries preconstricted with 1 nmol endothelin-1. This effect of ghrelin was blocked when the bath solution contained 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U0126), 4-amino-5-(4-methylphenyl)-7-(t-butyl) pyrazolo[3,4-d] pyrimidine (PP2), D-609, 2-[1-(3-dimethylaminopropyl)indol-3-yl]-3-(indol-3-yl) maleimide (GF109203x), pertussis toxin, 2-aminoethyl diphenylborinate (2-APB), indomethacin, (5Z,13E)-(9S,11S,15R)-9,15,Dihydroxy-11-fluoro-15-(2-indanyl)-16,17,18,19,20,pentanor-5,13-prostadienoic acid (AL-8810) - a non-selective prostanoid receptor antagonist, 5-(4-Chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethyl pyrazolo (SC-560) - a selective cyclooxygenase 1 inhibitor, ozagrel - a selective thromboxane A(2) synthase inhibitor or T prostanoid receptor antagonist GR32191B. It is concluded that ghrelin increases the force of contraction of human mesenteric arteries by a novel mechanism that involves Src kinase, mitogen-activated protein kinase kinase (MEK), cyclooxygenase 1 and T prostanoid receptor agonist, most probably thromboxane A(2).

Ghrelin is a 28-amino acid peptide hormone which modulates many physiological functions including cardiovascular homeostasis. Here we report some novel findings about the action of ghrelin on smooth muscle cells (SMC) freshly isolated from human mesenteric arteries. Ghrelin (10(-7) mol/l) significantly suppressed the iberiotoxin-blockable component of potassium currents (I(K)) and depolarized the cell membrane, while having no effect on Ca(2+) currents. Inhibition of inositol-trisphosphate (IP(3))-activated Ca(2+) release channels, depletion of sarcoplasmic reticulum (SR) Ca(2+) stores, blockade of phospholipase D (PLD) or protein kinase C (PKC) each abolished the effect of ghrelin on I(K), while the inhibition of phospholipase C (PLC) did not. These data imply that in human mesenteric artery SMC ghrelin suppresses I(K) via PLD, PKC and SR Ca(2+)-dependent signaling pathway.

The aim of the present study was to determine whether cobalt poisoning induces haem oxidase isoenzyme-1 (HO-1) in coronary artery smooth muscle, or accounts for any changes in coronary smooth muscle cell (SMCs) membrane ionic currents that could result from this type of heavy metal poisoning. In SMCs isolated from cobalt-treated guinea-pig coronaries, K+ channel currents (IK) were much smaller than those in cells isolated from non-treated animals. Haemin (HO substrate) increased IK concentration dependently. This effect was mimicked by 1% CO and was abolished by pretreatment of cells with a competitive HO inhibitor, by inhibitors of guanylyl cyclase, protein kinase G or phospholipase C, as well as by blocking inositol trisphosphate-dependent Ca release, or sarcoplasmic reticulum Ca-ATPase, or by bathing cells in Ca-free external solution. Expression of the Na/Ca exchanger-1 (NCX-1) protein was reduced substantially in SMCs from coronary arteries of cobalt-treated animals. No expression of HO-1 was detected. It is concluded that acute cobalt poisoning in vivo depresses Ca-sensitive K currents via CO-dependent modulation of intracellular calcium availability, most probably by suppressing the expression of NCX-1 protein.

Phospholipase A2 is an "interfacial" enzyme and its binding to negatively charged surfaces is an important step during catalysis. The Gln48 phospholipase A2 from the venom of Vipera ammodytes meridionalis plays the role of chaperone and directs a toxic His48 PLA2 onto its acceptor. In the venom the two phospholipases A2 exist as a postsynaptic neurotoxic complex, Vipoxin. The X-ray structure of Gln48 PLA2, complexed to sulphate ions, which mimic the negatively charged groups of anionic membranes, has been determined by the molecular replacement method and refined to 1.9A resolution. The protein forms a homodimer stabilized by ionic, hydrophobic, and hydrogen-bond interactions. The structure reveals two anion-binding sites per subunit. These sites are probably involved in interactions with the negatively charged membrane surface and, in this way, in the "targeting" of the toxic component to the receptors of the postsynaptic membranes. In the absence of the chaperone subunit the toxin changes the target of the physiological attack. A comparison of the homodimeric Gln48 PLA2 structure with that of the heterodimeric Vipoxin reveals differences in regions involved in the pharmacological activity of the toxin. This fact, except the active site histidine substitution, can explain the absence of toxicity in the Gln48 protein in comparison to the His48 phospholipase A2.

The neurotoxin vipoxin is the lethal component of the venom of Vipera ammodytes meridionalis. It is a heterodimer of a basic toxic His-48 phospholipase A2 (PLA2) and an acidic nontoxic Gln-48 PLA2. The shape of the neurotoxin and its separated components in solution as well as their interactions with calcium, the brain phospholipid phosphatidylcholine, and two inhibitors, elaidoylamide and vitamin E, were investigated by dynamic light scattering. Calcium binding is connected with a conformational change in vipoxin observed as a change of the hydrodynamic shape from oblate ellipsoid to a shape closer to a sphere. The Ca2+-bound form of vipoxin, which is catalytically active, is more compact and symmetric than the calcium-free heterodimer. Similar changes were observed as a result of the Ca2+-binding to the two separated subunits. In the presence of aggregated phosphatidylcholine, the neurotoxic complex dissociates to subunits. It is supposed that only the toxic component binds to the substrate, and the other subunit, which plays a chaperone function, remains in solution. The inhibition of vipoxin with the synthetic inhibitor elaidoylamide and the natural compound vitamin E changes the shape of the toxin from oblate to prolate ellipsoid. The inhibited toxin is more asymmetric in comparison to the native one. Similar, but not so pronounced, effects were observed after the inhibition of the monomeric and homodimeric forms of the toxic His-48 PLA2. Circular dichroism measurements in the presence of urea, methylurea, and ethylurea indicate a strong hydrophobic stabilization of the neurotoxin. Hydrophobic interactions stabilize not only the folded regions but also the regions of intersubunit contacts.

Carbon monoxide (CO) is well known as a relaxing substance in the vasculature, where it is released during the heme oxygenase (HO) reaction. Little is known about the tissue-specific targets of CO in smooth muscles. To date the functional role of CO in the coronary artery remains unclear. The expression of HO-2, the constitutive isoform of HO, but not of HO-1 (inducible HO isoform) was demonstrated by immunohistochemical reaction. Contractile studies, performed under isometrical conditions, showed that CO, as well as hemin (given as a substrate for HO), relax de-endothelized coronary smooth muscle after the blockade of neuronal transmission. The action of hemin was antagonized by preliminary treatment of the vessel with SnPPIX--a competitive inhibitor of HO. The relaxatory effects of hemin were abolished in the presence of guanylyl-cyclase or protein kinase G antagonists. Patch-clamp studies revealed that hemin caused activation of iberiotoxin-blockable K outward current (I(K)) via guanylyl-cyclase and protein-kinase-G-dependent mechanisms. This activation coincided with hyperpolarization of the plasma membrane of single coronary smooth muscle cells by 8+/-3 mV, which was prevented by preliminary exposure of cells to 10 microM SnPPIX. The I(K)-augmenting effect of hemin was not affected by pretreatment of cells with cyclopiazonic acid and/or ryanodine, blockers of phospholipase C or heparin (applied via pipette), but was not observed when ATP was omitted from the dialyzing solution, or in the presence of Na-free, ATP-containing pipette solution. The omission of Ca(2+) from the bath or the replacement of Na with Li in both pipette and bath media also prevented the I(K)-activating effect of hemin. These results suggest that the constitutive HO-2 in coronary artery smooth muscle cells plays role in the modulation of tone. At the level of smooth muscle cells CO and its precursor hemin may cause hyperpolarization of the plasma membrane by activation of iberiotoxin-sensitive I(K) presumably via PKG-dependent activation of the Na/Ca exchanger. This activation is thought to increase the submembrane Ca(2+) concentration in the vicinity of large-conductance, Ca(2+)-sensitive K channels, thus causing voltage-dependent inhibition of Ca(2+) entry and subsequent relaxation of the vessel.