Kolagen je v medicíně používán už po celá desetiletí. Nejpoužívanější je kolagen bovinní, který má známé nedostatky, jako antigenicitu, alergicitu a přenos zoonóz. Podle publikovaných informací se zdá být slibnou alternativou rybí kolagen. Předpokládá se, že je nízce antigenní, nealergenní a biologicky bezpečnější. Dále má pravděpodobně schopnost depotizace léčiv s možností kontrolovaného uvolňování léčiva . Cílem projektu, je systematicky a experimentálně vyhodnotit chemické, biologické, fyzikální a technologické vlastnosti vybraného rybího kolagenu, především s ohledem na jeho využití při výrobě implantátů a jako nosiče farmak. Na základě znalostí a rozsáhlých zkušeností expertního interdisciplinárního výzkumného týmu, stanoveného pro návrhy v oblasti výroby cévních protéz bude vyvinuta inovativní, bezpečnější, novější a hypoalergenní kolagenová protéza, s možností kontrolovaného uvolňování léčiv. Budou testovány i další výrobky z rybího kolagenu, jako např. pěny a materiály na krytí ran. Tímto projektem očekáváme významný dopad hned na několik odvětví biomedicínského průmyslu; For decades, collagen has frequently been used in medicine. The most typical one is bovine collagen that carries known issues such as antigenicity, allergenicity and zoonoses transmission. According to rather limited published data fish collagen seems as a promising alternative. It is believed to be low antigenic, non-allergenic and biologically safer. Further, it likely exhibits depotization effect on drugs, i.e. allows for controlled drug release. The project aim is to systemically, experimentally evaluate chemical, biological, physical and technological properties of select fish collagens, specifically with the respect to its potential use in implants and as a drug carrier. Based on the information gained and vast experience of established interdisciplinary research team in vascular prosthesis design, the novel, safer, nonallergic collagen-treated prosthesis with the capability of predictable drug release will be developed. Other collagen products such as foams and wound dressings will be tested. Significant impact on several areas of biomedical industry is expected.

• MeSH
• antigeny MeSH
• cévní protézy MeSH
• kolagen farmakokinetika   MeSH
• léky s prodlouženým účinkem MeSH
• nosiče léků farmakokinetika   MeSH
• rybí proteiny farmakokinetika   MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• farmacie a farmakologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Introduction: The aim of this study was to develop a prototype of an artificial blood vessel which has similar mechanical properties to a human saphenous vein graft and to experimentally verify the function of the prosthesis via ovine carotid bypass implantation. Material and methods: The prototype of an artificial graft prosthesis for low flow was developed and manufactured from a collagenous matrix and reinforcing polyester mesh. We compared the results of both the pressurisation and the mechanical stress evaluation tests of VSM with four types of hybrid vascular graft. The most similar graft (type II) was chosen for the first ovine model implantation. Results: Dominant behavior e.g. mechanical response of VSM graft in plots of circumferential and axial stress during loading is observed in circumferential direction. Average results of used VSM showed area of ideal mechanical response and the properties of artificial blood vessels were fitted into this area. Developed graft remained patent after 161 days of follow up in ovine model. Conclusions: The mechanical properties of the graft were designed and adjusted to be similar to the behaviour of human saphenous veins. This approach showed promising results and enhanced the final performance of the prosthesis.

• MeSH
• cévní protézy * MeSH
• cévy - implantace protéz metody   MeSH
• chirurgické síťky MeSH
• kolagen terapeutické užití   MeSH
• mechanický stres MeSH
• složené pryskyřice MeSH
• vena saphena transplantace   MeSH
• Publikační typ
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH

BACKGROUND: Median arcuate ligament syndrome (MALS) describes clinical symptoms in patients with stenosis of the celiac artery due to external compression by the ligament. There is an ongoing debate, whether sole release of the median arcuate ligament warrants long-term relief of the symptoms. MATERIALS AND METHODS: Eight patients diagnosed with MALS underwent open surgical treatment beginning with the release of the ligament. Systemic pressure and pressure in the left gastric artery were measured before and after division of the median arcuate ligament and release of the celiac artery. In patients with persistent gradient above 15 mm Hg after the release a PTFE bypass was performed. RESULTS: After the release, the pressure gradient decreased from 66 ± 19 to 48 ± 14 mm Hg (p = .001) and therefore in all patients either an aorto-celiac bypass (n = 6) or aorto-hepatic bypass (n = 2) was created. Consequently, the gradient decreased to 7 ± 2 mm Hg (p = .0001). One month postoperatively, three patients were free of symptoms and the rest reported relief of symptoms. CONCLUSIONS: Release of the celiac artery resulted in insufficient decrease of pressure gradient, which was achieved by bypassing the segment with favorable mid-term outcome. We believe that the effect of the release should always be assessed to decide on subsequent treatment.

• MeSH
• bolesti břicha diagnóza   etiologie   MeSH
• cévní rezistence fyziologie   MeSH
• chirurgická dekomprese metody   MeSH
• CT angiografie metody   MeSH
• Dunbarův syndrom diagnostické zobrazování   patofyziologie   chirurgie   MeSH
• hodnocení rizik MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• peroperační péče metody   MeSH
• předoperační péče metody   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• stupeň závažnosti nemoci MeSH
• tlak MeSH
• výkony cévní chirurgie metody   MeSH
• výsledek terapie MeSH
• vzorkové studie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Aim: The aim of this study was to evaluate short-term patency of the new prosthetic graft and its structural changes after explantation. Methods: The study team developed a three-layer conduit composed of a scaffold made from polyester coated with collagen from the inner and outer side with an internal diameter of 6 mm. The conduit was implanted as a bilateral bypass to the carotid artery in 7 sheep and stenosis was created in selected animals. After a period of 161 days, the explants were evaluated as gross and microscopic specimens. Results: The initial flow rate (median ± IQR) in grafts with and without artificial stenosis was 120 ± 79 ml/min and 255 ± 255 ml/min, respectively. Graft occlusion occurred after 99 days in one of 13 conduits (patency rate: 92%). Wall-adherent thrombi occurred only in sharp curvatures in two grafts. Microscopic evaluation showed good engraftment and preserved structure in seven conduits; inflammatory changes with foci of bleeding, necrosis, and disintegration in four conduits; and narrowing of the graft due to thickening of the wall with multifocal separation of the outer layer in two conduits. Conclusions: This study demonstrates good short-term patency rates of a newly designed three-layer vascular graft even in low-flow conditions in a sheep model.

• MeSH
• arteriae carotides účinky léků   MeSH
• cévní protézy MeSH
• cévy - implantace protéz metody   MeSH
• kolagen metabolismus   MeSH
• okluze cévního štěpu farmakoterapie   MeSH
• ovce MeSH
• prospektivní studie MeSH
• protézy - design metody   MeSH
• průchodnost cév účinky léků   MeSH
• zákroky plastické chirurgie metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The objective of our study was to compare the cellular and extracellular matrix (ECM) structure and the biomechanical properties of human pericardium (HP) with the normal human aortic heart valve (NAV). HP tissues (from 12 patients) and NAV samples (from 5 patients) were harvested during heart surgery. The main cells in HP were pericardial interstitial cells, which are fibroblast-like cells of mesenchymal origin similar to the valvular interstitial cells in NAV tissue. The ECM of HP had a statistically significantly (p < 0.001) higher collagen I content, a lower collagen III and elastin content, and a similar glycosaminoglycans (GAGs) content, in comparison with the NAV, as measured by ECM integrated density. However, the relative thickness of the main load-bearing structures of the two tissues, the dense part of fibrous HP (49 ± 2%) and the lamina fibrosa of NAV (47 ± 4%), was similar. In both tissues, the secant elastic modulus (Es) was significantly lower in the transversal direction (p < 0.05) than in the longitudinal direction. This proved that both tissues were anisotropic. No statistically significant differences in UTS (ultimate tensile strength) values and in calculated bending stiffness values in the longitudinal or transversal direction were found between HP and NAV. Our study confirms that HP has an advantageous ECM biopolymeric structure and has the biomechanical properties required for a tissue from which an autologous heart valve replacement may be constructed.

• MeSH
• aorta * MeSH
• biomechanika MeSH
• biopolymery chemie   MeSH
• extracelulární matrix metabolismus   MeSH
• lidé MeSH
• mechanické jevy * MeSH
• perikard cytologie   MeSH
• pevnost v tahu MeSH
• srdeční chlopně cytologie   MeSH
• testování materiálů MeSH
• tkáňové inženýrství * MeSH
• tkáňové podpůrné struktury chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Extracorporeal membrane oxygenation (ECMO) is an established tool for respiratory and circulatory support. In computed tomography, altered hemodynamics in ECMO patients requires special considerations and handling in contrast injection and its timing. In this article, we demonstrate changes in hemodynamics in ECMO patients captured on contrast-enhanced CT examinations and pitfalls in strategies for contrast injection in relation to the ECMO flow, cardiac function and the placement of ECMO cannulas. Contrast-enhanced CT of patients with ECMO requires prior knowledge of the ECMO cannulas, central venous lines, changes of hemodynamics induced by low cardiac output and the influence of adjustment of ECMO on blood flow in order to optimize injection of the contrast material and timing of the scan. Special considerations include temporary reduction of the ECMO flow, selection of the injection site and increasing volume or flow rate of the contrast material.

• MeSH
• dospělí MeSH
• hemodynamika * MeSH
• kontrastní látky aplikace a dávkování   analýza   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mimotělní membránová oxygenace metody   MeSH
• počítačová rentgenová tomografie metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• biokompatibilní materiály účinky záření   MeSH
• ethylenoxid MeSH
• kolagen MeSH
• polyestery MeSH
• sterilizace metody   MeSH
• testování materiálů metody   MeSH
• Publikační typ
• práce podpořená grantem MeSH

It is known that large arteries in situ are subjected to significant axial prestretch. This prestretch plays an important physiological role in optimizing the biomechanical response of an artery. It is also known that the prestretch declines with age. However, a detailed description of age-related changes in prestretch is available only for the abdominal aorta and for the femoropliteal artery. Our study presents results of measurements of axial prestretch in 229 left common carotid arteries excised in autopsies. It was found that the prestretch of the carotid artery correlates significantly with age ([Formula: see text], p value < 0.001). A linear regression model was used to fit the observations. Simultaneously with the measurement of the prestretch in the carotid artery, the axial prestretch was also measured in abdominal aorta. By comparing data obtained from these locations, it was concluded that the axial prestretch in the carotid artery is greater than in the abdominal aorta, and that atherosclerosis develops more rapidly in the abdominal aorta than in the carotid artery. Histological sections obtained from 8 carotid arteries and aortas suggest that the medial layer of the left common carotid artery is significantly thinner than aortic media (median/IQR: 0.343/0.086 vs. 0.482/0.172 mm, [Formula: see text] in Wilcoxon signed-rank test) and simultaneously that carotid media contains a lower number of elastic membranes (median/IQR: 26.5/11.8 vs. 31.5/11.8, [Formula: see text] in the Wilcoxon signed-rank test). This could be a reason for the different extent of the prestretch observed in aorta and in carotid artery. Our data sample also contains 5 measurements of the axial prestretch in abdominal aortas suffering from an aneurysm. It was found that aneurysmatic aortas also exhibit axial retraction when excised from in situ position. To the best of our knowledge, this is the first time that detailed data characterizing axial prestretch of the human left common carotid artery have been presented.

• MeSH
• aneurysma patologie   MeSH
• aorta abdominalis fyziologie   MeSH
• arteriae carotides fyziologie   MeSH
• ateroskleróza patologie   MeSH
• biofyzikální jevy * MeSH
• biologické modely * MeSH
• lidé MeSH
• lineární modely MeSH
• věkové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Aim. To compare the differences between medial and intercondylar infragenicular femoropopliteal prosthetic bypasses in terms of their midterm patency and limb salvage rates. Methods. Ninety-three consecutive patients with peripheral arterial disease who underwent a simple distal femoropopliteal bypass using a reinforced polytetrafluorethylene graft were included in this retrospective study. The bypass was constructed in the intercondylar route in 52 of the patients (group A) and in 41 in the medial route (group B). Results. Median observation time of the patients was 12.7 (IQR 4.6-18.5) months. There were 22 and 24 interventional or surgical procedures (angioplasty, stenting, thrombolysis, thrombectomy, or correction of the anastomosis) performed to restore patency of the reconstruction in groups A and B, respectively (p = 0.14). The 20-month primary, assisted, and secondary patency rates and limb salvage rates were 57%, 57%, 81%, and 80% in group A compared to 21%, 23%, 55%, and 82% in group B (p = 0.0012, 0.0052, 0.022, and 0.44, resp.). Conclusion. Despite better primary, assisted, and secondary patency rates in patients with a prosthetic infragenicular femoropopliteal bypass embedded in the intercondylar fossa compared to patients with the medial approach, there is no benefit in terms of the limb salvage rate and the number of interventions required to maintain patency of the reconstruction.

• MeSH
• arteria femoralis chirurgie   MeSH
• arteria poplitea chirurgie   MeSH
• dolní končetina chirurgie   MeSH
• lidé MeSH
• onemocnění periferních arterií * chirurgie   MeSH
• retrospektivní studie MeSH
• výkony cévní chirurgie * metody   MeSH
• záchrana končetiny MeSH
• zajištění kvality zdravotní péče MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• srovnávací studie MeSH