Оцінювання зволоженості гірських водозборів при математичному моделюванні дощових паводків

Розроблено процедуру оцінювання зволоженості водозбору, яка не потребує тривалого моделювання в оперативних умовах.Разработана процедура оценивания увлажненности водосбора, которая исключает необходимость продолжительного моделирования в оперативных условиях

Failure of decellularized porcine small intestinal submucosa as a heart valved conduit

Objective: Decellularized extracellular matrix made from porcine small intestinal submucosa, commercially available as CorMatrix (CorMatrix Cardiovascular, Inc, Roswell, Ga) is used off-label to reconstruct heart valves. Recently, surgeons experienced failures and words of caution were raised. The aim of this study was to evaluate decellularized porcine small intestinal submucosa as right-sided heart valved conduit in a xenogeneic animal model. Methods: A pulmonary valve replacement was performed with custom-made valved conduits in 10 lambs and 10 sheep (1 month [3 lambs and 3 sheep], 3 months [3 lambs and 3 sheep], 6 months [4 lambs and 4 sheep]). Valve function was assessed after implantation and before the animal was put to death. Explanted conduits were inspected macroscopically and analyzed using immunohistochemistry and scanning electron microscopy. They also underwent mechanical testing and testing for biochemical composition. Results: All valved conduits were successfully implanted. Five sheep and 2 lambs died due to congestive heart failure within 2 months after surgery. In the animals that died, the valve leaflets were thickened with signs of inflammation (endocarditis in 4). Five sheep and 8 lambs (1 month: 6 out of 6 animals, 3 months: 4 out of 6 animals, 6 months: 3 out of 8 animals) survived planned follow-up. At the time they were put to death, 5 lambs had significant pulmonary stenosis and 1 sheep showed severe regurgitation. A well-functioning valve was seen in 4 sheep and 3 lambs for up to 3 months. These leaflets showed limited signs of remodeling. Conclusions: Fifty percent of sheep and 20% of lambs died due to valve failure before the planned follow-up period was complete. A well-functioning valve was seen in 35% of animals, albeit with limited signs of tissue remodeling at ≤3 months after implantation. Further analysis is needed to understand the disturbing dichotomous outcome before clinical application can be advised

Early Determinants of Adverse Motor Outcomes in Preschool Children with a Critical Congenital Heart Defect

Neurodevelopmental disabilities are common in infants with critical congenital heart disease (CCHD). A prospective, longitudinal cohort study was conducted to establish the prevalence and early determinants of adverse motor outcomes in infants who underwent cardiac surgery with cardiopulmonary bypass before six months of age. Motor development was assessed in 147 preschoolers using the Movement Assessment Battery for children-II. Although the majority displayed an average motor development, 22% of preschool children with CCHD deteriorated in their motor developmental score compared to their previous assessment at 18 months, especially in those with an aortic arch anomaly (AAA) (35%). Individual stability over time appeared to be moderate and the number of children with a motor delay increased, up to 20% in children with AAA. Motor development up to 42 months was best predicted by gestational age, cardio pulmonary bypass time, aortic cross clamp time, number of heart catheterizations up to 18 months and early motor outcomes. The increase in number of preschool children with a motor delay underlines the importance of longitudinal screening of motor skills in children with CCHD at risk for adverse motor outcomes. Offering early interventions may protect their current and future cardiovascular health as motor development is an independent predictor of exercise capacity, physical activity and participation in daily living

Development of Non-Cell Adhesive Vascular Grafts Using Supramolecular Building Blocks

Cell-free approaches to in situ tissue engineering require materials that are mechanically stable and are able to control cell-adhesive behavior upon implantation. Here, the development of mechanically stable grafts with non-cell adhesive properties via a mix-and-match approach using ureido-pyrimidinone (UPy)-modified supramolecular polymers is reported. Cell adhesion is prevented in vitro through mixing of end-functionalized or chain-extended UPy-polycaprolactone (UPy-PCL or CE-UPy-PCL, respectively) with end-functionalized UPy-poly(ethylene glycol) (UPy-PEG) at a ratio of 90:10. Further characterization reveals intimate mixing behavior of UPy-PCL with UPy-PEG, but poor mechanical properties, whereas CE-UPy-PCL scaffolds are mechanically stable. As a proof-of-concept for the use of non-cell adhesive supramolecular materials in vivo, electrospun vascular scaffolds are applied in an aortic interposition rat model, showing reduced cell infiltration in the presence of only 10% of UPy-PEG. Together, these results provide the first steps toward advanced supramolecular biomaterials for in situ vascular tissue engineering with control over selective cell capturin

In situ tissue engineering of functional small-diameter blood vessels by host circulating cells only

\u3cp\u3eInflammation is a natural phase of the wound healing response, which can be harnessed for the in situ tissue engineering of small-diameter blood vessels using instructive, bioresorbable synthetic grafts. This process is dependent on colonization of the graft by host circulating cells and subsequent matrix formation. Typically, vascular regeneration in small animals is governed by transanastomotic cell ingrowth. However, this process is very rare in humans and hence less relevant for clinical translation. Therefore, a novel rat model was developed, in which cell ingrowth from the adjacent tissue is inhibited using Gore-Tex sheathing. Using this model, our aim here was to prove that functional blood vessels can be formed in situ through the host inflammatory response, specifically by blood-borne cells. The model was validated by implanting sex-mismatched aortic segments on either anastomoses of an electrospun poly(ɛ-caprolactone) (PCL) graft, filled with fibrin gel, into the rat abdominal aorta. Fluorescent in situ hybridization analysis revealed that after 1 and 3 months in vivo, over 90% of infiltrating cells originated from the bloodstream, confirming the effective shielding of transanastomotic cell ingrowth. Using the validated model, PCL/fibrin grafts were implanted, either or not loaded with monocyte chemotactic protein-1 (MCP-1), and cell infiltration and tissue development were investigated at various key time points in the healing cascade. A phased healing response was observed, initiated by a rapid influx of inflammatory cells, mediated by the local release of MCP-1. After 3 months in vivo, the grafts consisted of a medial layer with smooth muscle cells in an oriented collagen matrix, an intimal layer with elastin fibers, and confluent endothelium. This study proves the regenerative potential of cells in the circulatory system in the setting of in situ vascular tissue engineering.\u3c/p\u3

Aortic dissection masquerading as a code stroke: A single-centre cohort study

Introduction: Data on the incidence of acute aortic dissection in the code stroke population are scarce. We report estimated incidence, clinical manifestations, treatment and outcomes of patients with an acute aortic dissection in a code stroke cohort from a comprehensive stroke centre. Patients and methods: We used data from a single-centre prospective registry of consecutive adult patients who presented to the emergency department between 2015 and 2018 with neurological deficits suggestive of an acute stroke (‘code stroke’). All patients routinely underwent non-contrast computed tomography of the brain and computed tomography-angiography of the aortic arch, cervical and intracranial arteries. Results: Of 2874 code stroke patients, 1563 (54.4%) had acute ischaemia (ischaemic stroke or transient ischaemic attack). Fifteen patients (0.5% of code stroke patients and 0.8% of patients with acute ischaemia) had an acute aortic dissection (all Stanford classification type A). Discerning clinical manifestations were decreased consciousness in 11/15 (73%), pain in 8/15 (53%) and low systolic blood pressure (mean 106 mmHg, SD30). Acute aortic dissection was an incidental finding during computed tomography-angiography in 4/15 (27%). Two out of 15 patients (13%) received intravenous thrombolysis, 9/15 (60%) underwent aortic surgery and 10/15 (67%) died. Of those who survived, 3/5 (60%) had a good functional outcome (modified Rankin Scale 0–2). Discussion and Conclusion: In our comprehensive stroke centre, about 1/200 code stroke patients and 1/125 patients with acute ischaemia had an acute aortic dissection. Multicentre studies are necessary to acquire a more reliable estimate of the incidence of acute aortic dissection in the code stroke population. Given the ramifications of missing this diagnosis, imaging of the entire aortic arch is important in these patients

In situ tissue engineering of functional small-diameter blood vessels by host circulating cells only

\u3cp\u3eInflammation is a natural phase of the wound healing response, which can be harnessed for the in situ tissue engineering of small-diameter blood vessels using instructive, bioresorbable synthetic grafts. This process is dependent on colonization of the graft by host circulating cells and subsequent matrix formation. Typically, vascular regeneration in small animals is governed by transanastomotic cell ingrowth. However, this process is very rare in humans and hence less relevant for clinical translation. Therefore, a novel rat model was developed, in which cell ingrowth from the adjacent tissue is inhibited using Gore-Tex sheathing. Using this model, our aim here was to prove that functional blood vessels can be formed in situ through the host inflammatory response, specifically by blood-borne cells. The model was validated by implanting sex-mismatched aortic segments on either anastomoses of an electrospun poly(ɛ-caprolactone) (PCL) graft, filled with fibrin gel, into the rat abdominal aorta. Fluorescent in situ hybridization analysis revealed that after 1 and 3 months in vivo, over 90% of infiltrating cells originated from the bloodstream, confirming the effective shielding of transanastomotic cell ingrowth. Using the validated model, PCL/fibrin grafts were implanted, either or not loaded with monocyte chemotactic protein-1 (MCP-1), and cell infiltration and tissue development were investigated at various key time points in the healing cascade. A phased healing response was observed, initiated by a rapid influx of inflammatory cells, mediated by the local release of MCP-1. After 3 months in vivo, the grafts consisted of a medial layer with smooth muscle cells in an oriented collagen matrix, an intimal layer with elastin fibers, and confluent endothelium. This study proves the regenerative potential of cells in the circulatory system in the setting of in situ vascular tissue engineering.\u3c/p\u3

In situ tissue engineering of functional small-diameter blood vessels by host circulating cells only

Inflammation is a natural phase of the wound healing response, which can be harnessed for the in situ tissue engineering of small-diameter blood vessels using instructive, bioresorbable synthetic grafts. This process is dependent on colonization of the graft by host circulating cells and subsequent matrix formation. Typically, vascular regeneration in small animals is governed by transanastomotic cell ingrowth. However, this process is very rare in humans and hence less relevant for clinical translation. Therefore, a novel rat model was developed, in which cell ingrowth from the adjacent tissue is inhibited using Gore-Tex sheathing. Using this model, our aim here was to prove that functional blood vessels can be formed in situ through the host inflammatory response, specifically by blood-borne cells. The model was validated by implanting sex-mismatched aortic segments on either anastomoses of an electrospun poly(ε-caprolactone) (PCL) graft, filled with fibrin gel, into the rat abdominal aorta. Fluorescent in situ hybridization analysis revealed that after 1 and 3 months in vivo, over 90% of infiltrating cells originated from the bloodstream, confirming the effective shielding of transanastomotic cell ingrowth. Using the validated model, PCL/fibrin grafts were implanted, either or not loaded with monocyte chemotactic protein-1 (MCP-1), and cell infiltration and tissue development were investigated at various key time points in the healing cascade. A phased healing response was observed, initiated by a rapid influx of inflammatory cells, mediated by the local release of MCP-1. After 3 months in vivo, the grafts consisted of a medial layer with smooth muscle cells in an oriented collagen matrix, an intimal layer with elastin fibers, and confluent endothelium. This study proves the regenerative potential of cells in the circulatory system in the setting of in situ vascular tissue engineering