Vasopressin stimulates erythropoiesis.

Purpose: Thrombus perviousness, depicting the interaction of occlusive clot with contrast media as measured with computed tomography (CT) is a relatively new imaging biomarker in acute ischemic stroke (AIS). This approach holds the potential to tailor revascularization strategies and post-interventional treatments, thereby enhancing functional outcomes. However, its predictive value is not yet conclusive despite its association with several clinical parameters. Methods: This scoping review provides a comprehensive overview of 51 articles that explore this issue. It focuses on the analysis of applied methodology in measuring perviousness, the predictive value of perviousness based on available data, and the future perspectives and potentials this biomarker may have in AIS imaging. Results: Although some data are contradictory, in the vast majority of published studies, pervious thrombi were easier to remove with mechanical thrombectomy, responded better to thrombolytic treatment and showed better functional outcome than impervious thrombi. The methodology of measuring perviousness is not yet standardized, which may lead to inconsistency in the findings. New data on time-resolved (dynamic) perviousness show more promising results and refined characterization of occlusive thrombi in AIS.

Configuration changes of the parent artery (PA) after flow diverter (FD) stent reconstruction, due to the bending force of the device, may have an additional role in aneurysm occlusion due to the secondary alteration of intra-aneurysmal hemodynamics related to the geometry alteration of the vessel. To determine the degree of parent artery deformation (PAD) and aneurysm occlusion rates after deployment of two different types of FDs. Patients treated with two different designs of cobalt-chromium braid (48 and 64 wire braid) structure FD were subjects to analysis. Vascular angle changes at the level of the reconstructed segment immediately after FD deployment and at one year follow-up were measured and the potential relationship with aneurysmal occlusion rate were analyzed. Forty-two patients harboring 48 aneurysms were included in the present study. The aneurysms were divided into side wall (85.4%) and bifurcation types (14.6%). Twenty-six aneurysms were treated using the Pipeline (48 wire braid) FD (54.2%) and 22 using the Evolve FD (64 wire braid, 45.8%). Of the 48 aneurysms, 42 (87.5%) met the primary endpoint of complete occlusion at 12 months. The median post-deployment angle change was 7.04° ± 4.59° for the Pipeline, and 5.05° ± 2.49° for the Evolve, whereas the median 12-month follow-up angle change was 15.49° ± 10.99° and 10.01° ± 8.83° respectively. Parent artery angle changes were significantly higher in the bifurcation group compared to the side wall group both during procedure and at 12-month follow-up. Angle change had a statistically non-significant association with complete aneurysm occlusion. PAD starts immediately after deployment and remodeling continues over 1 year after. Aneurysms located in the vessel bifurcation were more prone to parent artery straightening after FDs deployment than side wall aneurysms. Furthermore, Pipeline appeared to be more prone to inducing vascular deformation, compared with Evolve.

Background: The predictive value of thrombus perviousness in acute ischemic stroke (AIS), as measured by computed tomography (CT), has been intensively studied with conflicting results. In this study, we investigate the predictive potential of the novel concept of dynamic perviousness using three-dimensional (3D) volumetric evaluation of occlusive thrombi. Methods: The full thrombus volume in 65 patients with a hyperdense artery sign on non-contrast CT (NCCT), who underwent mechanical thrombectomy (MT), was segmented. Perviousness maps were computed voxel-wise for the entire thrombus volume as thrombus attenuation increase (TAI) between NCCT and CT angiography (CTA) as well as between CTA and late venous phase CT (CTV). Perviousness was analyzed for its association with NIHSS at admission, Thrombolysis In Cerebral Infarction (TICI) score, and number of MT passes. Results: The mean late-uptake TAI of thrombi with NIHSS scores greater than 21 at admission was approximately 100% higher than for lower scored NIHSS (p between 0.05 and 0.005). Concerning revascularization results, thrombi requiring less than four MT passes had ca. 80% higher group mean late-uptake TAI than clots requiring four or more passes (p = 0.03), and thrombi with TICI score III had ca. 95% higher group mean late-uptake TAI than thrombi with TICI II (p = 0.03). Standard perviousness showed no significant correlation with MT results. Conclusion: Standard thrombus perviousness of 3D clot volume is not associated with revascularization results in AIS. In contrast, dynamic perviousness assessed with a voxel-wise characterization of 3D thrombi volume may be a better predictor of MT outcomes than standard perviousness.

Exercise elicits a systemic adaptation reaction, involving both neuroendocrine and cellular/paracrine stress responses, exemplified by the sympathoadrenergic activity and the release of cellular Hsp70 into the circulation. Regular sports training is known to result in increased fitness. In this study, we characterized the plasma norepinephrine and Hsp70 levels and modeled their relationship in response to exercise stress by bicycle ergometer in 12 trained judoka athletes and in 10 healthy controls. Resting norepinephrine was similar in both groups, whereas Hsp70 was significantly higher in controls compared to athletes. Intense exercise load induced both norepinephrine and Hsp70 elevation. However, both norepinephrine and Hsp70 were significantly lower in athletes compared to the control group. A reaction kinetic model was developed that provided a quantitative description of norepinephrine-facilitated extracellular Hsp70 release, congruent with the experimental data. Our study indicates that exercise-induced norepinephrine and extracellular Hsp70 may be coordinated responses to physiological stress, which are robustly affected by regular sports activity.

Background: Acute ischemic stroke (AIS) is one of the leading causes of death in the industrialized world and causes a heavy personal and economic burden. Thrombus perviousness, measured with pre-interventional computed tomography (CT), is a relatively new imaging biomarker with the potential to estimate clinical outcome in AIS and optimize therapy. However, reported findings on the relationship between thrombus perviousness and clinical parameters in AIS are conflicting. In this study, we investigated the characteristics of the time-resolved contrast agent uptake in thrombi and the predictive potential for clinical outcomes. Methods: We analyzed 55 AIS patients who underwent pre-interventional CT perfusion and recanalization with mechanical thrombectomy. A thrombus with a visible hyperdense artery sign was segmented in 2D. Thrombus standard perviousness was measured as the mean thrombus attenuation increase (TAI) between CT angiography (CTA) and NCCT. For dynamic perviousness, the time-resolved contrast agent uptake curve (CAU) was derived from a 30-phase CT perfusion (CTP) measurement. The rise time (t_rise) and the TAI increase rate per second (∆d), as well as the time window for the 10th (tW₁₀), 20th (tW₂₀), and 30th (tW₃₀) percentiles of the CAU peak, were calculated. The standard and dynamic perviousness (t_rise, ∆d, tW₁₀, tW₂₀, and tW₃₀₎ were analyzed for their associations with clinical outcomes (3-month mRS) with the Wilcoxon signed rank test. Results: Dynamic perviousness was associated with the clinical outcome. The group mean t_rise and ∆d for thrombi with good clinical outcomes (mRS ≤ 2) were approximately 20% lower (p = 0.04) and 36% higher (p = 0.02) than those for thrombi with poor outcomes (mRS > 2). The time windows for the 10, 20, and 30% maximum contrast agent concentrations in the thrombus were approximately 40% (p = 0.004), 18% (p = 0.02) and 33% (p = 0.004) lower in thrombi with good outcomes than in thrombi with poor outcomes, respectively. Standard perviousness showed no association with clinical outcome. Conclusion: Dynamic perviousness from perfusion imaging retrieves the CAU characteristics of thrombi with greater resolution detail than standard perviousness. Thrombi with relatively fast contrast agent uptake dynamics are more prone to good clinical outcomes than thrombi with slow uptake dynamics.