Political Representation and the Human Rights Model of Disability:A Bulgarian Case

Bulgaria ratified the UNCRPD in 2012 but what can be observed locally is a chronic failure to embrace and implement its fundamental principles. This article explores the current state and the future of the human rights model of disability in Bulgaria. It focuses on a fundamental pillar of the human rights model, namely the participation of disabled people in all decision making that affects them. We expose how the local definition of political “representation” diverges from what the human rights model envisages, and we argue that the organisations that are expected to “represent” disabled people remain stuck into needs-based attitudes and models. This makes them agents not of change but of further affirmation and cementing of practices and solutions that turn disabled people into “objects” of care, lock them into paternalist forms of dependency, and strongly depoliticise disability issues in the country

Perivascular adipose tissue as regulator of the force of artery contractions in health and disease

During the last two decades, perivascular adipose tissue (PVAT) has been revealed as an important regulator of vascular processes such as proliferation of smooth muscle cells, pro- and anti-oxidant reactions in the vascular wall, angiogenesis, inflammation, apoptosis of neutrophils, migration of monocytes and others. PVAT derived mediators either increase or decrease the amplitudes of the force of artery contraction measured using isometric small vessel myography. In healthy animals and humans predominates the relaxing effect while in diseases the contractile influence of PVAT is common. In aging and pathological conditions like atherosclerosis and diabetes, or with environmental factors like tobacco smoke and high-fat diet, the phenotype of perivascular adipocytes is changed from anti-inflammatory to pro-inflammatory. This change is accompanied by a significant rearrangement of mediators released from PVAT

BK channels in tail artery vascular smooth muscle cells of normotensive (WKY) and hypertensive (SHR) rats possess similar calcium sensitivity but different responses to the vasodilator iloprost

It has been reported that, in the spontaneously hypertensive rat (SHR) model of hypertension, different components of the G-protein/adenylate cyclase (AC)/Calcium-activated potassium channel of high conductance (BK) channel signaling pathway are altered differently. In the upstream part of the pathway (G-protein/AC), a comparatively low efficacy has been established, whereas downstream BK currents seem to be increased. Thus, the overall performance of this signaling pathway in SHR is elusive. For a better understanding, we focused on one aspect, the direct targeting of the BK channel by the G-protein/AC pathway and tested the hypothesis that the comparatively low AC pathway efficacy in SHR results in a reduced agonist-induced stimulation of BK currents. This hypothesis was investigated using freshly isolated smooth muscle cells from WKY and SHR rat tail artery and the patch-clamp technique. It was observed that: (1) single BK channels have similar current–voltage relationships, voltage-dependence and calcium sensitivity; (2) BK currents in cells with a strong buffering of the BK channel activator calcium have similar current–voltage relationships; (3) the iloprost-induced concentration-dependent increase of the BK current is larger in WKY compared to SHR; (4) the effects of activators of the PKA pathway, the catalytic subunit of PKA and the potent and selective cAMP-analogue Sp-5,6-DCl-cBIMPS on BK currents are similar. Thus, our data suggest that the lower iloprost-induced stimulation of the BK current in freshly isolated rat tail artery smooth muscle cells from SHR compared with WKY is due to the lower efficacy of upstream elements of the G-Protein/AC/BK channel pathway

Bone healing following different types of osteotomy: Scanning electron microscopy (SEM) and three-dimensional SEM analyses

The aim of the present study was to compare dynamics of the bone healing process after different types of osteotomies. In total, 24 Wistar rats were subjected to different types of osteotomy performed with standard steel bur, piezosurgery, contact, and non-contact Erbium:yttrium-aluminum-garnet (Er:YAG) laser ablation. The animals were randomly divided into four groups, to be euthanized immediately after the procedure, or at 1, 2, or 3 weeks after surgery. The obtained bone samples were analyzed by scanning electron microscopy (SEM). Immediately after surgery, there were significant differences in the appearance of the bone defects, with presence of bone fragments and debris after standard steel bur preparation, compared with the clean smooth walls and relatively sharp edges in all other groups. The initial bone formation in defects prepared by piezosurgery was observed to be the most rapid. After 3 weeks, all bone defects were completely restored; although, differences in the healing pattern were noted, with a modest initial delay in healing after laser preparation. The first stage of the bone healing process was delayed when contact and non-contact Er:YAG laser modes were used and accelerated by piezosurgery; however, the results after 3 weeks demonstrated similar restitution of defects in all tested groups

Review of cyanotoxicity studies based on cell cultures

Cyanotoxins (CTs) are a large and diverse group of toxins produced by the peculiar photosynthetic prokaryotes of the domain Cyanoprokaryota. Toxin-producing aquatic cyanoprokaryotes can develop in mass, causing “water blooms” or “cyanoblooms,” which may lead to environmental disaster—water poisoning, extinction of aquatic life, and even to human death. CT studies on single cells and cells in culture are an important stage of toxicological studies with increasing impact for their further use for scientific and clinical purposes, and for policies of environmental protection. The higher cost of animal use and continuous resistance to the use of animals for scientific and toxicological studies lead to a progressive increase of cell lines use. This review aims to present (1) the important results of the effects of CT on human and animal cell lines, (2) the methods and concentrations used to obtain these results, (3) the studied cell lines and their tissues of origin, and (4) the intracellular targets of CT. CTs reviewed are presented in alphabetical order as follows: aeruginosins, anatoxins, BMAA (β-N-methylamino-L-alanine), cylindrospermopsins, depsipeptides, lipopolysaccharides, lyngbyatoxins, microcystins, nodularins, cyanobacterial retinoids, and saxitoxins. The presence of all these data in a review allows in one look to advance the research on CT using cell cultures by facilitating the selection of the most appropriate methods, conditions, and cell lines for future toxicological, pharmacological, and physiological studies

Kv2.1 channels prevent vasomotion and safeguard myogenic reactivity in rat small superior cerebellar arteries

Vascular smooth muscle voltage-gated potassium (Kv) channels have been proposed to contribute to myogenic autoregulation. Surprisingly, in initial experiments, we observed that the Kv2 channel inhibitor stromatoxin induced vasomotion without affecting myogenic tone. Thus, we tested the hypothesis that Kv2 channels contribute to myogenic autoregulation by fine-tuning the myogenic response. Expression of Kv2 channel mRNA was determined using real-time PCR and ‘multiplex’ single-cell RT-PCR. Potassium currents were measured using the patch-clamp technique. Contractile responses of intact arteries were studied using isobaric myography. Expression of Kv2.1 but not Kv2.2 channels was detected in intact rat superior cerebellar arteries and in single smooth muscle cells. Stromatoxin, a high-affinity inhibitor of Kv2 channels, reduced smooth muscle Kv currents by 61% at saturating concentrations (EC50 36 nmol/L). Further, stromatoxin (10–100 nmol/L) induced pronounced vasomotion in 48% of the vessels studied. In vessels not exhibiting vasomotion, stromatoxin did not affect myogenic reactivity. Notably, in vessels exhibiting stromatoxin-induced vasomotion, pressure increases evoked two effects: First, they facilitated the occurrence of random vasodilations and/or vasoconstrictions, disturbing the myogenic response (24% of the vessels). Second, they modified the vasomotion by decreasing its amplitude and increasing its frequency, thereby destabilizing myogenic tone (76% of the vessels). Our study demonstrates that (i) Kv2.1 channels are the predominantly expressed Kv channels in smooth muscle cells of rat superior cerebellar arteries, and (ii) Kv2.1 channels provide a novel type of negative feedback mechanism in myogenic autoregulation by preventing vasomotion and thereby safeguarding the myogenic response

The Role of Insulin Therapy in Correcting Hepcidin Levels in Patients with Type 2 Diabetes Mellitus

Objectives: Iron overload can cause or contribute to the pathogenesis of type 2 diabetes mellitus (T2DM), but how the major parameters of iron metabolism change in different settings of diabetes are still unclear. The aim of this study was to determine the relationship between iron, ferritin, and hepcidin levels in diabetic patients and the effect of insulin treatment. Methods: The study included 80 subjects, 60 with T2DM and 20 without (control group). Serum hepcidin, insulin, ferritin, and iron levels were determined as well as other clinical parameters. The associations between these parameters were analyzed between both groups. Results: Hepcidin levels expressed as mean± standard deviation between groups showed no significant changes (14.4±6.7 ng/mL for the control group, and 18.4±7.9 ng/mL for patients with diabetes, p = 0.069). Parameters of iron metabolism showed modest correlation with the parameters of glucose metabolism. However, the correlation between ferritin and insulin in both groups was statistically significant (p = 0.032; ρ = 0.480 vs. p = 0.011; ρ = 0.328). Conclusions: Our study showed that hepcidin levels in patients with T2DM on insulin therapy do not change, which might be a result of treatment with insulin. In this context, insulin treatment can be used as a novel method for correction of hepcidin levels. By correcting hepcidin levels, we can prevent cellular iron overload and reduce the risk of diabetes

An Approach for Analysis and Assessment of the Pollution Indices of the Struma River in the Bulgarian Section

In this work, 13 pollution indices in 10 stations of the Struma river in the Bulgarian section are investigated: temperature (T°C), pH, dissolved oxygen (DO), oxygen saturation (SO2), electrical conductivity (EC), biological oxygen demand (BOD), permanganate oxidation (KMn3O4), ammonia nitrogen (NH3-N), nitrite nitrogen (NO2-N), nitrate nitrogen (NO3-N), orthophosphates (PO4), dissolved substances (DS), and unsolved substances (US). The analysis and assessment of the studied indices of pollution of the Struma river in the Bulgarian section is carried out by means of a recently proposed multi-criteria decision-making method called intercriteria decision analysis (ICDA). Application of ICDA showed that we have a degree of agreement for T°C for all stations with very few exceptions. This also applies to DO, KMn3O4, SO2 and EC. We had a degree of disagreement for all other indices. From the conducted research, it can be concluded that for all indicators, it is necessary to develop mathematical models in the studied stations according to the studied indicators of the Struma river in Bulgaria. The application of ICDA allows us to examine the correlations between individual indicators and eliminate those that are highly dependent on each other