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Energy security has always been the most crucial objective for nations seeking sustainable economic growth. The present study examined the impact of political institutions on energy security using panel data from 34 high-income countries for the years 2000–2018. To investigate the mechanisms through which political variables affect energy security, the study took into account the roles of economic growth, trade, financial development, and urbanization. For the empirical estimation of the research’s objective, Panel robust Driscoll-Kraay standard error technique and Dumitrescu and Hurlin causality test are used. Empirical findings demonstrated the positive effects of trade, economic growth, and financial development on energy security. Particularly, political institutions have a positive impact on energy security in the sample nations. However, the findings showed urbanization has a negative influence on energy security. Additionally, there is a two-way causal link between trade, financial development, and energy security. The study suggested that more green investment in the energy sector for sustainable development might be a result of strong political institutions.

Dialysis access-related distal ischaemia is a rare yet potentially rather risky complication of haemodialysis angioaccess. Timely diagnosis is crucial to target both the goals of the access team: first of all to preserve the function of the hand ideally along with angioaccess patency. Unfortunately for some patients, urgent access ligation and central vein catheter insertion would be needed to save the hand. After a first clinical examination to determine the diagnostic suspicion, the ultrasound evaluation would provide nearly all the needed information to confirm the diagnosis and to determine the most appropriate procedure to rescue the patient from distal ischaemia. In some cases, photoplethysmography would help in the differential diagnosis of other non-ischaemic causes of similar signs and symptoms. Angiography would complete the preoperative evaluation for some. Dialysis access-related distal ischaemia would be briefly reviewed, and a deep description of the ultrasound examination tools and findings would be provided for a tailored therapeutic approach.

Aims Patients on chronic haemodialysis have a wide range of changes in cardiac function and structure, including left ventricular hypertrophy, dilation and diastolic dysfunction or pulmonary hypertension. All these changes were linked to increased mortality in previous studies. High-flow arteriovenous fistulas (AVF) are supposed to be a factor contributing to their development. This study investigated the early effect of surgical AVF blood flow (Qa) reduction on these changes in patients with or without heart failure changes. Methods and results Forty-two patients in chronic haemodialysis programme with high-flow AVF (Qa over 1500 mL/min), indicated for surgery for ≥1 of the following indications: 1.manifest heart failure; 2.hand ischemia; 3.advanced structural heart changes detected by echocardiography. The patients underwent echocardiography on selection visit, before blood flow reducing surgery and six weeks thereafter. The Qa reduction led to decrease of left ventricular mass (p = 0.02), end-diastolic volume (p = 0.008), end-diastolic diameter (p = 0.003) and left atrial volume (p = 0.0006). Diastolic function improved. Similarly, right ventricular diameter and right atrial volume decreased (p = 0.000001 and 0.00009, respectively) together with the decrease of estimated pulmonary artery systolic pressure. 81% of patients suffered from pulmonary hypertension prior to surgery, only 36% thereafter. Conclusion The surgical restriction of the hyperkinetic circulation leads to several improvements of heart structure and function, which was linked to higher mortality in other studies. The beneficial effect of Qa reduction is present even in patients without symptoms of heart failure. The contribution of AVF must be considered with structural or functional heart changes.

Physical examination (PE) is considered the backbone before vascular access (VA) placement, during maturation period and for follow-up. However, it may be inadequate in identifying suitable vasculature, mainly in comorbid patients, or in detecting complications. This review highlights the advantages of ultrasound imaging to manage VA before placement, during maturation and follow-up. Furthermore, it analyses the future perspectives in evaluating early and late VA complications thank to the availability of multiparametric platforms, point of care of ultrasound, and portable/wireless systems. Technical improvements and low-cost systems should favor the widespread ultrasound-based VA surveillance programs. This significant turning point needs an adequate training of nephrologists and dialysis nurses and the standardization of exams, parameters, and procedures.

Aims High‐flow arteriovenous fistula (AVF) for haemodialysis leads to profound haemodynamic changes and sometimes to heart failure (HF). Cardiac output (CO) is divided between the AVF and body tissues. The term effective CO (COef) represents the difference between CO and AVF flow volume (Qa) and better characterizes the altered haemodynamics that may result in organ hypoxia. We investigated the effects of Qa reduction on systemic haemodynamics and on brain oxygenation. Methods and results This is a single‐centre interventional study. Twenty‐six patients on chronic haemodialysis with high Qa (>1500 mL/min) were indicated for surgical Qa reduction for HF symptoms and/or signs of structural heart disease on echocardiography. The included patients underwent three sets of examinations: at 4 months and then 2 days prior and 6 weeks post‐surgical procedure. Clinical status, echocardiographical haemodynamic assessment, Qa, and brain oximetry were recorded. All parameters remained stable from selection to inclusion. After the procedure, Qa decreased from 3.0 ± 1.4 to 1.3 ± 0.5 L/min, P 2.0 L/min. These observations were mirrored by higher brain oxygenation and might explain HF symptoms and improved haemodynamics even in asymptomatic high Qa patients.

Hemodialysis arteriovenous fistula is a shortcut of the systemic circulation and sometimes fistula flow exceeds 2 L/min. Possible hemodynamic and clinical consequences are discussed.

Background: Heart failure (HF) is a frequent cause of morbidity and mortality of end-stage kidney disease (ESKD) patients on hemodialysis. It is not easy to distinguish HF from water overload. The traditional HF definition has low sensitivity and specificity in this population. Moreover, many patients on hemodialysis have exercise limitations unrelated to HF. Therefore, we postulated two new HF definitions ((1) Modified definition of the Acute Dialysis Quality Improvement working group; (2) Hemodynamic definition based on the calculation of the effective cardiac output). We hypothesize that the newer definitions will better identify patients with higher number of endpoints and with more advanced structural heart disease. Methods: Cohort, observational, longitudinal study with recording predefined endpoints. Patients ( n = 300) treated by hemodialysis in six collaborating centers will be examined centrally in a tertiary cardiovascular center every 6–12 months lifelong or till kidney transplantation by detailed expert echocardiography with the calculation of cardiac output, arteriovenous dialysis fistula flow volume calculation, bio-impedance, and basic laboratory analysis including NTproBNP. Effective cardiac output will be measured as the difference between measured total cardiac output and arteriovenous fistula flow volume and systemic vascular resistance will be also assessed non-invasively. In case of water overload during examination, dry weight adjustment will be recommended, and the patient invited for another examination within 6 weeks. A composite major endpoint will consist of (1) Cardiovascular death; (2) HF worsening/new diagnosis of; (3) Non-fatal myocardial infarction or stroke. The two newer HF definitions will be compared with the traditional one in terms of time to major endpoint analysis. Discussion: This trial will differ from others by: (1) detailed repeated hemodynamic assessment including arteriovenous access flow and (2) by careful assessment of adequate hydration to avoid confusion between HF and water overload.

Changes in access blood flow (QVA) are of utmost importance in vascular access (VA) management when deciding on VA referral for an intervention. The article elucidates impact of different factors on QVA changes. Methods: Records of 10,000 QVA measurement performed in 549 patients over 20 years were used as retrospective and anonymized data source, making ethical commission involvement unnecessary. Two approaches are used to elucidate association of QVA changes with different factors: analyses of smaller cohorts in which both the QVA and the respective factor were measured (e.g. association of QVA with cardiac output (CO)), or—in case of rare phenomena—a form of a well illustrated case reports was used (e.g. association of QVA and Kt/V). Results: Significant increase in CO after permanent VA creation (3-4-fold of the QVA value) was found. Impact of intradialytic CO changes on QVA is attenuated by relatively stable VA resistance compared to systemic resistance. Blood pressure impact is much stronger and it should therefore be noted at each QVA measurement. As reproducibility of different QVA measurement methods varies, use of the same method should be preferred. Direction of the arterial needle insertion in VA affects the QVA measured, especially in synthetic grafts, too. Also patient’s own QVA variability may be quite high. All this makes KDOQI/EBPG recommended acceptable QVA drops too strict, they should be revised. In re-stenoses prone patients, measurement intervals should be shortened, too. Conclusion: QVA values are significantly affected by many factors. Their knowledge appears essential for safe and effective VA surveillance and management.

Background: Decreased cerebral perfusion and oxygenation are common in hemodialysis patients. Magnitude of the arteriovenous fistula involvement in this phenomenon is not known. The aim of this study was to investigate the effect that a short-term arteriovenous fistula flow interruption has on cerebral oxygenation and to review and suggest possible explanations. Methods: In 19 patients, basic laboratory and clinical data were obtained and arteriovenous fistula flow volume was measured by ultrasonography. Baseline regional cerebral oxygen saturation (rSO2) was measured by near-infrared spectroscopy. Manual pressure was then applied on the fistula, resulting in total blood flow interruption. After 1 min of manual compression, rSO2 and blood pressure values were noted again. The compression-related change in rSO2 was assessed, as well as its association with arteriovenous fistula flow volume, blood pressure, and other parameters. Results: Mean cerebral rSO2 increased after arteriovenous fistula compression (from 53.6% ± 11.4% to 55.6% ± 10.8%; p = 0.000001; 95% confidence interval = 1.39–2.56). The rSO2 increase was higher in patients with lower rSO2 at baseline (r = −0.46; p = 0.045). Conclusion: A significant rise in cerebral oxygenation was observed following the manual compression of arteriovenous fistula. Therefore, the arteriovenous fistula could have a role in impaired cerebral oxygenation in hemodialysis patients.

Chronic hemodialysis therapy required regular entry into the patient’s blood stream with adequate flow. The use of arteriovenous fistulas and grafts is linked with lower morbidity and mortality than the use of catheters. However, these types of accesses are frequently affected by stenoses, which decrease the flow and lead to both inadequate dialysis and access thrombosis. The idea of duplex Doppler ultrasound surveillance is based on the presumption that in-time diagnosis of an asymptomatic significant stenosis and its treatment prolongs access patency. Details of performed trials are conflicting, and current guidelines do not support ultrasound surveillance. This review article summarizes the trials performed and focuses on the reasons of conflicting results. We stress the need of precise standardized criteria of significant access stenosis and the weakness of the metaanalyses performed.

The goal of vascular access creation is to achieve a functioning arteriovenous fistula (AVF) or arteriovenous graft (AVG). An autologous fistula has been shown to be superior to AVG or to central venous catheters (CVCs) with lowest rate of re-intervention, but vessel obstruction or immaturity accounts for 20 % to 54% of cases with primary failure of AVF. This review is focused on the factors influencing maturation; indication and timing of preoperative mapping/creation of vascular access; ultrasound parameters for creation AVF/AVG; early postoperative complications following creation of a vascular access; ultrasound determinants of fistula maturation and endovascular intervention in vascular access with maturation failure. However, vascular accesses that fail to develop, have a high incidence of correctable abnormalities, and these need to be promptly recognized by ultrasonography and managed effectively if a high success rate is to be expected. We review approaches to promoting fistula maturation and duplex ultrasonography (DUS) of evaluating vascular access maturation.

Chronic kidney disease is associated with increased cardiovascular morbidity and mortality. A well-functioning vascular access is associated with improved survival and among the available types of vascular access the arterio-venous (AV) fistula is the one associated with the best outcomes. However, AV access may affect heart function and, in some patients, could worsen the clinical status. This review article focuses on the specific cardiovascular hemodynamics of dialysis patients and how it is affected by the AV access; the effects of an excessive increase in AV access flow, leading to high-output heart failure; congestive heart failure in CKD patients and the contraindications to AV access; pulmonary hypertension. In severe heart failure, peritoneal dialysis (PD) might be the better choice for cardiac health, but if contraindicated suggestions for vascular access selection are provided based on the individual clinical presentation. Management of the AV access after kidney transplantation is also addressed, considering the cardiovascular benefit of AV access ligation compared to the advantage of having a functioning AVF as backup in case of allograft failure. In PD patients, who need to switch to hemodialysis, vascular access should be created timely. The influence of AV access in patients undergoing cardiac surgery for valvular or ischemic heart disease is also addressed. Cardiovascular implantable electronic devices are increasingly implanted in dialysis patients, but when doing so, the type and location of vascular access should be considered.

Chronic kidney disease (CKD) leads to profound metabolic and hemodynamic changes, which damage other organs, such as heart and brain. The brain abnormalities and cognitive deficit progress with the severity of the CKD and are mostly expressed among hemodialysis patients. They have great socio-economic impact. In this review, we present the current knowledge of involved mechanisms.

Brain tissue oxygenation (rSO2) measured by near-infrared spectroscopy (NIRS) is lower in hemodialysis patients than in the healthy population and is associated with cognitive dysfunction. The involved mechanisms are not known. We conducted this study to identify the factors that influence the rSO2 values in end-stage renal disease (ESRD) patients and to describe rSO2 changes during hemodialysis. We included a cohort of ESRD patients hemodialyzed in our institution. We recorded rSO2 using INVOS 5100C oximetry system (Medtronic, Essex, U.K.) and analyzed changes in basic laboratory values and hemodynamic fluctuations. Baseline rSO2 was lower in patients with heart failure (45.2±8.3 % vs. 54.1±7.8 %, p=0.006) and was significantly linked to higher red cell distribution width (RDW) (r=-0.53, p˂0.001) and higher BNP level (r=-0.45, p=0.01). The rSO2 value decreased in first 15 min of hemodialysis, this decrease correlated with drop in white blood count during the same period (r=0.43, p=0.02 in 10 min, r=0.43, p=0.02 in 20 min). Lower rSO2 values in patients with heart failure and higher RDW suggest that hemodynamic instability combined with vascular changes probably leads to worse cerebral oxygenation in these patients. Decrease of rSO2 in 15th minute of hemodialysis accompanied with a significant drop in leukocyte count could be explained by complement activation.

Větsina pacientů s chronickým onemocněnim ledvin umira na kardiovaskularni komplikace. Echokardiografie je zakladni metoda k odhaleni větsiny z nich. Zahrnuji předevsim dilataci a dysfunkce leve komory i leve sině, hypertrofii leve komory, diastolickou dysfunkci leve komory, kalcifikacni postiženi srdce, ktere může vest až k rozvoji stenotických vad, dysfunkci prave komory a plicni hypertenzi. Zvlastnosti pacientů s chronickým selhanim ledvin je cyklicky se měnici stav hydratace a přitomnost nizkoodporoveho dialyzacniho zkratu (přistupu pro hemodialýzu). Tyto faktory zasadně ovlivňuji aktualni echokardiografický nalez.

Background/Aims: High rates of cognitive impairment (CI) are an alarming problem in patients undergoing chronic hemodialysis (HD). Its pathophysiology remains unclear and there are indications that brain ischemia might be one of the key causes. Cerebral tissue oxygenation, as measured by near-infrared spectroscopy, is known to be decreased in HD patients. However, it is unknown whether CI is associated or not associated with lower cerebral oxygenation in these patients. The primary aim of our study was to probe this possible association. Our secondary aim was to assess other factors possibly related to cerebral ischemia and CI. Methods: Thirty-nine patients treated by chronic HD were included in this cross-sectional study. All measurements were performed before the initiation of an HD session. The Montreal Cognitive Assessment (MoCA) was administered according to published recommendations. Regional saturation of oxygen (rSO2) of the left frontal lobe was measured using the INVOS 5100C device. Basic medical history and laboratory data were recorded, and handgrip strength was analyzed. We used the unpaired t test to compare the rSO2 and other variables between cognitively normal patients (MoCA score ≥26) and those who displayed CI (MoCA score Results: Cognitively impaired patients had lower brain rSO2 values compared to cognitively normal patients (48 ± 9 vs. 57 ± 10%, p = 0.01). Among other variables, higher red cell distribution width (15.8 ± 1.9 vs. 13.8 ± 1.6%, p = 0.01) and lower hand grip strength (49.2 ± 23.3 vs. 99.3 ± 31.4 lbs, p < 0.001) also displayed a significant association with CI. The relation between rSO2 and MoCA score was significant after adjustment for age and gender (p = 0.007). Conclusion: Decreased brain oxygenation is associated with weaker cognitive performance in patients undergoing chronic HD. Further understanding the causes of cerebral ischemia in HD patients could lead to the prevention of cognitive decline in this population.

Cardiovascular complications are responsible not only for the high mortality, but also the morbidity of end-stage renal disease patients. Cyclic changes of fluid load, together with the altered metabolism, are responsible and are mirrored in many particular parts of the heart. A review of the mechanisms involved is presented and the role of dialysis access is highlighted.

Funding Acknowledgements Grant of the Grant Agency of Charles University and grant of the Czech Health Research council Introduction Over 50% of patients treated by chronic haemodialysis programme die of cardiovascular diseases. Changes of heart structure and function can be detected by echocardiography. The most frequent changes are left ventricle hypertrophy (LVH) and its diastolic dysfunction. One of the considered contributing mechanisms is the hyperkinetic circulation. Purpose The aim of this study was to analyse the effect of high flow arteriovenous fistula (AVF) on eft ventricular hypertrophy and diastolic function. Materials and methods We included 30 patients with a high-flow arteriovenous fistula into the study, indicated for AVF blood flow reduction because of heart failure or hand ischemia. All the patients underwent echocardiographic examination and ultrasonographic measurement of AVF blood flow before and 6 weeks after the surgery. Results The AVF banding led to significant reduction of Qa (from 2977 ± 1408 to 1295 ± 610 mL/min; p ˂ 10-6, accompanied by significant decrease of cardiac index (from 4.34 ± 1.09 to 3.56 ± 0.90 L/min.m2). These findings were accompanied by significant reduction of left ventricle mass index (from 125 ± 31 to 116 ± 32 g/m2; p = 0.04) and by improvement of diastolic dysfunction grade (from 1.66 ± 0.67 to 1.14 ± 0.95; p = 0.03). The maximum velocity of tricuspid regurgitation decreased (from 3.1 ± 0.4 to 2.7 ± 0.5), and so did the left atrium volume index (from 47 ± 14 to 42 ± 15 mL/m2; p = 0.01). Conclusions LVH and diastolic dysfunction are frequent in haemodialysis patients; hyperkinetic circulation caused by high-flow arteriovenous fistula is one of the significant contributing mechanisms. Surgical reduction of AVF blood flow improved diastolic function of the left ventricle and reduced the hypertrophy in our patient population. AVF flow volume should be always considered during cardiological examination of haemodialysis patients.

The objective of this prospective randomized single-center study was to compare primary and secondary patency rates, number of percutaneous transluminal angioplasty (PTA) interventions and cost-effectiveness among PTA, deployment of a stent, or a stent graft in the treatment of failing arteriovenous dialysis grafts (AVG) due to restenosis in the venous anastomosis or the outflow vein. Altogether 60 patients with failing AVG and restenosis in the venous anastomosis or the outflow vein were randomly assigned to either PTA, placement of a stent (E-Luminexx(®)) or stent graft (Fluency Plus(®)). After the procedure, patients with stent or stent graft received dual antiplatelet therapy for the next three months. Follow-up angiography was scheduled at 3, 6, and 12 months unless requested earlier due to suspected stenosis or malfunction of the access. Subsequently, angiography was performed only if requested by the clinician. During a median follow-up of 22.4 (IQR=5.7) months patients with PTA, stent, or stent graft required 3.1±1.7, 2.5±1.7, or 1.7±2.1 (P=0.031) secondary PTA interventions. The primary patency rates were 0, 18 and 65% at 12 months and 0, 18 and 37% at 24 months in the PTA, stent, and stent graft group respectively (P

BackgroundCognitive deficit is a common problem in end-stage renal disease (ESRD) patients. Ultrafiltration and hemodialysis lead to profound hemodynamic changes. The aim of this pilot study was to describe brain and hand oxygenation values in ESRD patients and their changes during hemodialysis.MethodsTwenty-seven patients treated by chronic hemodialysis and 17 controls patients of the same age were included in the study. Regional saturation of oxygen (SrO2) was measured at the brain frontal lobe and at the hand with dialysis access using the INVOS 5100C. In 17 of ESRD patients, SrO2was also monitored throughout hemodialysis. Finger systolic blood pressure and basic hemodialysis and laboratory data were collected.ResultsDialysis patients had lower brain and also hand SrO2values at rest (51.5 ± 10.9 vs. 68 ± 7%, p2to 47 ± 8%, p2decrease was related to the ultrafiltration rate, the hand SrO2decrease to the finger pressure and to blood hemoglobin.ConclusionsChronic dialysis patients suffer from tissue ischemia and that even worsens after the beginning of hemodialysis. This observation may contribute to the understanding of cognitive deficit etiology.

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon’s experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon’s specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs.

The prevalence of the left ventricular hypertrophy (LVH) is very high in end-stage renal disease treated by hemodialysis. Diastolic dysfunction is a frequent consequence and leads to the development of heart failure with preserved ejection fraction. New American/European echocardiographic guidelines for the assessment of diastolic function simplified the evaluation and were published recently. The aim of this study was to reveal if the new guidelines stratify asymptomatic hemodialysis patients by the levels of brain-natriuretic peptide (BNP). A cohort of 46 patients hemodialyzed in one center with the lack of overt heart failure, systolic dysfunction, arrhythmia or significant valvular disease were examined by echocardiography before and after a single hemodialysis and blood samples for BNP analysis were drawn at both occasions. The LVH was present in 53% of patients, concentric remodeling in another 17%. Higher indexed left ventricular mass was related to higher BNP levels (r = 0.58, p = 0.0001). Before hemodialysis, diastolic dysfunction was present in 61%: grade 1 in 25%, grade 2 in 21% and grade 3 in 8%. The higher grade of diastolic dysfunction was associated with the incremental increase of BNP. The post-dialysis echocardiography did not allow the assessment of diastolic function in as many as 37% of patients. Our study has shown that the application of the current guidelines for the assessment of diastolic function based on simple four criteria differentiate hemodialysis symptomless patients with preserved systolic function according to BNP levels. BNP levels also rose together with the left ventricular mass. The ratio E/eʹ medial seemed to be a better predictor of increased BNP than E/eʹ lateral or E/eʹ averaged.

Background: Creation of vascular access leads to considerable local haemodynamic changes with decreased hand perfusion. Distal limb tissues then represent a model of hand ischaemia effect on muscles. The aim of our study was to investigate how the presence of vascular access influences the hand muscle strength in end-stage renal disease patients. Methods: We included 52 chronically haemodialysed patients with upper limb access without clinical signs of hand ischaemia. Muscle strength was evaluated by dynamometry. Finger pressure was measured on the second and fourth fingers and averaged for further analysis. Thenar tissue oxygenation (rSO2) was analysed using near-infrared spectroscopy. All examinations were performed in both the hands. Basic laboratory analysis was added. Data were processed with unpaired t-test and correlation analysis. Results: Hands with dialysis access had lower values of handgrip strength (54.2 ± 29.1 lbs vs 48.6 ± 23.4 lbs, p = 0.0006), systolic finger pressure (127.1 ± 32.0 mmHg vs 101.4 ± 31.6 mmHg, p < 10−8) and of thenar rSO2 (45.8% ± 12.9% vs 42.5% ± 13.3%, p = 0.002). Muscle strength (handgrip) was directly related to the thenar oxygenation ( r = 0.36; p = 0.014) and to the finger systolic pressure ( r = 0.38; p = 0.007) on the access extremity. On the extremity without dialysis access, handgrip strength was inversely related to patient’s age ( r = −0.41, p = 0.003), dialysis vintage ( r = −0.32, p = 0.02) and red cell distribution width ( r = −0.37, p = 0.01). Conclusion: The presence of dialysis access leads to the decrease of finger pressure, oxygenation, and also muscle strength even in the absence of clinically overt hand ischaemia. All these parameters are interrelated. This study underlines the consequences of inadequate muscle perfusion.

Vascular stenosis is often described only by its percentage in both clinical and scientific praxis. Previous studies gave inconclusive results regarding the effect of stenosis eccentricity on its hemodynamic effect. The aim of this experimental study was to investigate and quantify the effect of stenosis severity and eccentricity on the pressure drop. A combination of pressure and flow measurements by Particle Imaging Velocimetry (PIV) method was used. Models of the same stenosis significance but with different levels of eccentricity were studied in vitro by PIV. This study has shown that stenosis asymmetry is associated with more profound pressure drop and flow volume decrease. On the contrary, pressure drop and flow volume decrease were not further significantly influenced by the level of asymmetry. Hemodynamic changes associated with stenosis eccentricity must be taken into account in both clinical and scientific studies.

Pakistan's mobile phone market is one of the world's fastest growing markets with a subscriber base of 137 million users. Competition in the country's telecommunication industry is dominated by four players and customer demand is high. In addition Pakistan is the first country in South Asia to have implemented Mobile Number Portability (MNP) in March 2007. MNP is a facility that allows mobile subscribers to switch between service providers without changing their existing phone numbers. Mobile phone service provider's selection may be influenced by various factors. Therefore this research was undertaken to explore factors affecting MNP and to determine which factors were most influential in the selection of mobile phone service providers in a developing economy like Pakistan. Moreover the study also probed into differences in customer perceptions between pre-paid and post-paid customers. This exploratory study is based on primary data collected from 300 customers using services of different cellular companies who had experienced MNP facility. Factor analysis was carried out on obtained data and reliability of the resultant scale was verified to achieve the objectives of the study. The outcome of this research provided a concise framework of the various dimensions of customer choice. Contrary to previous researches the result of this study indicated that infrastructural services customer relationships call quality and promotional packages were the most important factors affecting MNP. However price of services was found less important factor in selection of telecommunication service providers. This study also showed that pre-paid and post-paid customers can be significantly different for many value-added services and promotional tools. (C) 2017 The Authors. Published by IASE. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The correlation between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intoxication and the parameters of metabolic impairment was examined in the last eight male survivors of 80 workers exposed to TCDD during the production of herbicides in a chemical factory in 1965-1967. Their median TCDD blood level was 112 (46-390) pg/g lipids, and the median TCDD body deposit was 3.9 (0.8-11.7) μg. This puts these patients into the most severely intoxicated group of subjects, according to back-calculated levels of TCDD. The median TCDD blood level in eight controls was 12 pg/g (0.10 to 22.2 pg/g). Markers of metabolic impairment - diabetes, dyslipidaemia, arterial hypertension, carotid artery plaque, skin microvascular reactivity, eye fundus hypertensive angiopathy and history of coronary heart disease - were assessed and compared to a general male population of comparable age. Measured parameters compared with a population of comparable age were as follows: prevalence of diabetes (62.5% versus 17.6%), arterial hypertension (87.5% versus 71.8%), dyslipidaemia (87.5% versus 88.8%), history of coronary heart disease (62.5% versus 26.0%) and eye fundus hypertension angiopathy (50% versus 14%). All eight patients (100% versus 43%) developed plaques in carotid arteries, six had stenosis50% and two had a carotid intervention (stenting or endarterectomy). Total cholesterol levels decreased compared to the earlier study this patient group in 2008, most likely due to a more intensive use of lipid-lowering drugs. Several metabolic parameters were higher (diabetes as much as 3.5-fold) in the group of severely TCDD-intoxicated subjects than in a general population of comparable age. This suggests that TCDD plays a role in the development of metabolic impairment and vascular changes.

Günümüzde, bir dergi kapağına veya bir televizyon reklamına baktığımızda yüksek olasılıkla gösterilen kadınlar uzun boylu ve gerçeklikten uzak ölçüde zayıftır. Medya ve toplumumuz, medya tarafından standartları oluşturulmuş bu güzellik kavramına uymayanları kabul etmemeye başlamıştır. Bu araştırmanın amacı, medyadaki beden imgesinin genç kadınlar üzerinde oluşturduğu öz güvensizlik, yeme bozuklukları ve bedenlerinin yetersizlikleri fikirlerini bulmak ve kadınlar üzerindeki etkilerini gözlemlemektir.Araştırma genç kadınlara yapılan anketlerden elde edilen bilgiler doğrultusunda rakamlarla desteklenmiştir. Araştırma sonuçları göstermiştir ki medyanın rolü ve mütemadiyen yansıttığı mükemmel beden ve daha zayıf olunması gerekliliği fikri yüzünden genç kadınlar görünüş ve bedenleri için çok endişelidir. Medyadaki beden imgesi kadınlarda sadece beden öz güvensizliğini artırmakla kalmaz, dahası yeme bozuklukları ve öz saygı eksikliğine yol açar. Today, if we look at a magazine cover or a television commercial, the odds are that the woman are being shown as tall and extremely thin. Media and our society have eventually begun to cast out those who do not fit this ideal image of beauty which has been set as a standard by the media. This research aims in finding and examining the impact of the body image in media on the female adolescents, with the specific focus laid on the body dissatisfaction, self-esteem and eating disorders. The research is quantitative in nature and the focus has been laid to collect the data through the questionnaires from the adolescent females. The research results identified and revealed that the young women are very much concerned about their looks and bodies because of the role of media and its influence that is dynamically reflecting perfect body images and preference of becoming slimmer. Moreover, the body image in media not only influences by increasing the body dissatisfaction but creates eating disorders and causes decrease in self-esteem of female adolescents as well. 86

Endothelial activation and dysfunction may play a significant role in the progression of breast cancer. In our study we examined markers of endothelial activation (soluble ICAM-1, P-selectin, E-selectin) in 98 young patients with breast cancer (< 40 years). In 50 of them (and 20 age-matched controls) we also measured flow mediated vasodilation. Patients with breast cancer had significantly higher serum levels of soluble E-selectin, P-selectin and ICAM-1, P-selectin was higher in patients with larger tumors, node involvement and seemed to be apredictor of poor outcome. We were unable to find significant difference in the parameters of flow mediated vasodilation between patients with breast cancer and healthy subjects, although both peak blood flow (PBF) and flow mediated vasodilation (FMD) seemed to be skewed compared to healthy subjects toward mean and lower levels. Cluster analysis enabled us to distinguish several larger groups of patients with different degree of endothelial activation and function and different outcome. Group of patients with high E-selectin, high ICAM-1 (higher endothelial activation) and low VEGF (putative endothelial damage) had more frequently negative estrogen receptors and had worse outcome compared to the group of patients with lower E-selectin, lower ICAM-1 and mostly positive estrogen receptors. Further studies of larger groups of patients should help to identify the panel of endothelial markers which could help in predicting the outcome of young patients with breast cancer.