The key role of the endothelium in vascular-dependent diseases led to an increase in scientific interest in examining the endothelial function as a tool for screening, as well as for monitoring of the disease and its treatment. In the period from 2016 till 2019, a high level of scientific interest in the assessment of endothelial function has been observed, as expressed in the number of published clinical trials between 369 and 477 per year with the total number of subjects between 49,634 and 75,934. Currently, none of the known methods of assessing vascular endothelial function is widely used in clinical practice. This may be a result of various factors: scientific (lack of standardization in terms of quantitative indicators of endothelial function), formal (lack of official recommendations for endothelial assessment), financial (the best-validated methods and devices are costly, which renders it unsustainable to use them in screening diagnostics) and technological (high susceptibility of many measurement methods to errors). Nevertheless, it can be expected that non-invasive methods for the early detection of endothelial dysfunction in screening programs will gradually gain importance.
Background and Objectives: Recently, novel noiseless device for the assessment of baroreceptor function with the neck suction (NS) has been presented. In this study, we present another in-house approach to the variable-pressure neck chamber method. Our device offers further critical improvements. First, it enables delivery of negative (NS) as well as positive pressure (neck pressurizing, NP) in a noiseless manner. Second, we used small, 3D-printed cups positioned over the carotid sinuses instead of cumbersome neck collar to improve subject comfort and to test feasibility of tracking the pressure-induced changes in carotid artery with ultrasonography.Methods: Five healthy, non-smoking, normal-weight subjects aged 29 ± 3 years (mean ± SD) volunteered for the study. Heart rate (HR, bpm) and mean arterial pressure (MAP, mmHg) responses to short, 7-s long episodes of NS and NP were recorded. Each trial consisted of 12 episodes of variable-pressure: six episodes of NS (suction ranging between -10 and -80 mmHg) and six episodes of NP (pressure ranging between + 10 and + 80 mmHg). Carotid artery sonography was performed during the NS and NP in four subjects, on another occasion.Results: The variable-pressure episodes resulted consistently in the expected pattern of hemodynamic alterations: HR and MAP increases or decreases following the NP and NS, respectively, as evidenced by the coefficient of determination (R2) of ≥0.78 for the carotid-HR response curve (for all five participants) and the carotid-MAP response curve (for four out of five participants; the curve cannot be calculated for one subject). We found a linear, dose-dependent relation between the applied pressure and the systolic-diastolic difference in carotid artery diameter.Conclusion: The novel device enables noiseless stimulation and unloading of the carotid baroreceptors with the negative and positive pressure, respectively, applied on the subject’s neck via small, asymmetric and one-side flattened, 3D-printed cups. The unique design of the cups enables concomitant visualizing of the carotid artery during the NS or NP administration, and thereby direct monitoring of the intensity of mechanical stimulus targeting the carotid baroreceptors.
Objectives: Venous thrombosis represents a major clinical problem, both because of its high incidence and the fact that is often complicated with fatal pulmonary embolism. D-dimer level is the diagnostic parameter used to exclude venous thrombosis and to confirm thrombosis revealed by diagnostic imaging studies. The aim of this study was to assess D-dimer levels in a group of patients scheduled for femoropopliteal bypass and to compare results of this laboratory test to those obtained in a group of volunteers without lower limb ischaemia. Material and methods:The study group consisted of 102 patients presenting with lower limb ischaemia (50 with stage IIb according to Fontaine's classification and 52 with stage III) and 49 individuals in the control group. Results: Levels of D-dimer differed significantly between the groups. In patients presenting with Fontaine's stage IIb, Fontaine's stage III, and in control group they were, respectively: 0.87 ±0.31 µg/ml, 0.90 ±0.95 µg/ml, and 0.44 ±0.21 µg/ml. Conclusions: In comparison with healthy controls, D-dimer levels were significantly higher in patients presenting with lower limb ischaemia.
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