Huntingtin (HTT)-lowering therapies hold promise to slow down neurodegeneration in Huntington's disease (HD). Here, we assessed the translatability and long-term durability of recombinant adeno-associated viral vector serotype 5 expressing a microRNA targeting human HTT (rAAV5-miHTT) administered by magnetic resonance imaging-guided convention-enhanced delivery in transgenic HD minipigs. rAAV5-miHTT (1.2 × 1013 vector genome (VG) copies per brain) was successfully administered into the striatum (bilaterally in caudate and putamen), using age-matched untreated animals as controls. Widespread brain biodistribution of vector DNA was observed, with the highest concentration in target (striatal) regions, thalamus, and cortical regions. Vector DNA presence and transgene expression were similar at 6 and 12 months after administration. Expression of miHTT strongly correlated with vector DNA, with a corresponding reduction of mutant HTT (mHTT) protein of more than 75% in injected areas, and 30 to 50% lowering in distal regions. Translational pharmacokinetic and pharmacodynamic measures in cerebrospinal fluid (CSF) were largely in line with the effects observed in the brain. CSF miHTT expression was detected up to 12 months, with CSF mHTT protein lowering of 25 to 30% at 6 and 12 months after dosing. This study demonstrates widespread biodistribution, strong and durable efficiency of rAAV5-miHTT in disease-relevant regions in a large brain, and the potential of using CSF analysis to determine vector expression and efficacy in the clinic.

• MeSH
• genetická terapie MeSH
• genetické vektory genetika   MeSH
• Huntingtonova nemoc * genetika   terapie   MeSH
• lidé MeSH
• mikro RNA * metabolismus   MeSH
• miniaturní prasata metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• prasata MeSH
• protein huntingtin genetika   metabolismus   MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Introduction: Pulsed field ablation (PFA) exploits the delivery of short high-voltage shocks to induce cells death via irreversible electroporation. The therapy offers a potential paradigm shift for catheter ablation of cardiac arrhythmia. We designed an AC-burst generator and therapeutic strategy, based on the existing knowledge between efficacy and safety among different pulses. We performed a proof-of-concept chronic animal trial to test the feasibility and safety of our method and technology. Methods: We employed 6 female swine - weight 53.75 ± 4.77 kg - in this study. With fluoroscopic and electroanatomical mapping assistance, we performed ECG-gated AC-PFA in the following settings: in the left atrium with a decapolar loop catheter with electrodes connected in bipolar fashion; across the interventricular septum applying energy between the distal electrodes of two tip catheters. After procedure and 4-week follow-up, the animals were euthanized, and the hearts were inspected for tissue changes and characterized. We perform finite element method simulation of our AC-PFA scenarios to corroborate our method and better interpret our findings. Results: We applied square, 50% duty cycle, AC bursts of 100 μs duration, 100 kHz internal frequency, 900 V for 60 pulses in the atrium and 1500 V for 120 pulses in the septum. The inter-burst interval was determined by the native heart rhythm - 69 ± 9 bpm. Acute changes in the atrial and ventricular electrograms were immediately visible at the sites of AC-PFA - signals were elongated and reduced in amplitude (p < 0.0001) and tissue impedance dropped (p = 0.011). No adverse event (e.g., esophageal temperature rises or gas bubble streams) was observed - while twitching was avoided by addition of electrosurgical return electrodes. The implemented numerical simulations confirmed the non-thermal nature of our AC-PFA and provided specific information on the estimated treated area and need of pulse trains. The postmortem chest inspection showed no peripheral damage, but epicardial and endocardial discolorations at sites of ablation. T1-weighted scans revealed specific tissue changes in atria and ventricles, confirmed to be fibrotic scars via trichrome staining. We found isolated, transmural and continuous scars. A surviving cardiomyocyte core was visible in basal ventricular lesions. Conclusion: We proved that our method and technology of AC-PFA is feasible and safe for atrial and ventricular myocardial ablation, supporting their systematic investigation into effectiveness evaluation for the treatment of cardiac arrhythmia. Further optimization, with energy titration or longer follow-up, is required for a robust atrial and ventricular AC-PFA.

• Publikační typ
• časopisecké články MeSH

The project is to test the effectiveness of the new design of self-expandable, biodegradable stent in the prevention of biliary anastomotic stenosis, based on applied research on a porcine model. It the second part the ex vivo, and subsequently, in vivo study will test a new prototype of balloon catheter – electrodes for non thermal tissue ablation method called irreversible electroporation. The published results will compare the healing of the anastomosis with and without the use of protective biodegradable stenting, in relation to short-term and long-term complications. They will also describe the reaction of liver and biliary tract to the ablation procedure with the new balloon catheter, along with an evaluation of the early and long-term complications of the procedure. The goal is to use this methodology in the clinical practice to reduce morbidity and treatment costs of patients requiring treatment of biliary tract (liver transplantation, biliary tract resection) and the treatment of malignant stenosis of the biliary tract and creation of industrial pattern for new device.

Náplní projektu je na základě aplikovaného výzkumu na porcinním modelu ověřit účinnost nového designu biodegradabilního samoexpandibilního stentu v prevenci stenozy anastomozy na žlučových cestách. V druhé části ex vivo a následně in vivo testování nového prototypu balónového katetru - elektrody, prostřednictvím kterého bude možné provádět ablaci tkáně non termální metodou, tzv. ireverzibilní elektroporací.. Výstupem projektu budou impaktované publikace popisující výsledky srovnání hojení anastomoz s a bez užití protektivní biodegradabilní stentáže z hlediska krátkodobých i dlouhodobých komplikací a popis reakce jaterní tkáně a žlučových cest na ablaci sledování poškození vaskulárních struktur v okolí spolu se zhodnocením komplikací v časných i dlouhodobých. Plánem je využití této metodiky přímo v klinické praxi pro snížení morbidity a nákladů na léčbu pacientů s nutností léčby nedilatovaných žlučových cest (transplantace jater, resekce žlučových cest) a léčby maligních stenóz žlučových cest. Dalším výstupem je přihlášení užitného vzoru pro vyvíjený nástroj pro elektroporaci.

• MeSH
• angioplastika MeSH
• biotechnologie MeSH
• elektroporace MeSH
• intravitální mikroskopie MeSH
• nemoci žlučových cest chirurgie   MeSH
• stenóza prevence a kontrola   terapie   MeSH
• stenty MeSH
• vstřebatelné implantáty MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• biomedicínské inženýrství
• gastroenterologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

BACKGROUND: Choosing the appropriate animal model for development of novel technologies requires an understanding of anatomy and physiology of these different models. There are little data about the characteristics of different animal models for the study of technologies used for epicardial ablation. We aimed to compare the incidence of ventricular arrhythmias during epicardial radiofrequency ablation between swine and canine models using novel epicardial ablation catheters. METHODS: We conducted a retrospective study using data obtained from epicardial ablation experiments performed on swine (Sus Scrofa) and canine (Canis familiaris) models. We compared the incidence of ventricular arrhythmias during ablation between swine and canine using multivariate regression analysis. Six swine and six canine animals underwent successful epicardial radiofrequency ablation. A total of 103 ablation applications were recorded. RESULTS: Ventricular arrhythmias requiring cardioversion occurred in 13.11% of radiofrequency ablation applications in swine and 9.75% in canine (relative risk: 117.6%, 95% confidence interval [CI]: 83.97-164.69, animal-based odds ratio [OR]: .55, 95% CI: .23-61.33; P = .184). When adjusting for application position, duration of ablation and power, the odds of developing potentially lethal ventricular arrhythmia in swine increased significantly compared to canine (OR: 3.60, 95% CI: 1.35-9.55; P = .010). CONCLUSIONS: The swine myocardium is more susceptible to developing ventricular arrhythmias compared to canine model during epicardial ablation. This issue should be carefully considered in future studies.

• MeSH
• incidence MeSH
• katetrizační ablace metody   MeSH
• komorová tachykardie etiologie   MeSH
• modely nemocí na zvířatech * MeSH
• perikard chirurgie   MeSH
• prasata MeSH
• psi MeSH
• retrospektivní studie MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

PURPOSE: To compare the accumulation and effect of liposomal doxorubicin in liver tissue treated by radiofrequency ablation (RFA) and irreversible electroporation (IRE) in in vivo porcine models. MATERIALS AND METHODS: Sixteen RFA and 16 IRE procedures were performed in healthy liver of two groups of three pigs. Multi-tined RFA parameters included: 100 W, target temperature 105°C for 7 min. 100 IRE pulses were delivered using two monopolar electrodes at 2250 V, 1 Hz, for 100 µsec. For each group, two pigs received 50 mg liposomal doxorubicin (0.5 mg/kg) as a drip infusion during ablation procedure, with one pig serving as control. Samples were harvested from the central and peripheral zones of the ablation at 24 and 72 h. Immunohistochemical analysis to evaluate the degree of cellular stress, DNA damage, and degree of apoptosis was performed. These and the ablation sizes were compared. Doxorubicin concentrations were also analyzed using fluorescence photometry of homogenized tissue. RESULTS: RFA treatment zones created with concomitant administration of doxorubicin at 24 h were significantly larger than controls (2.5 ± 0.3 cm vs. 2.2 ± 0.2 cm; p = 0.04). By contrast, IRE treatment zones were negatively influenced by chemotherapy (2.2 ± 0.4 cm vs. 2.6 ± 0.4 cm; p = 0.05). At 24 h, doxorubicin concentrations in peripheral and central zones of RFA were significantly increased in comparison with untreated parenchyma (0.431 ± 0.078 µg/g and 0.314 ± 0.055 µg/g vs. 0.18 ± 0.012 µg/g; p < 0.05). Doxorubicin concentrations in IRE zones were not significantly different from untreated liver (0.191 ± 0.049 µg/g and 0.210 ± 0.049 µg/g vs. 0.18 ± 0.012 µg/g). CONCLUSIONS: Whereas there is an increased accumulation of periprocedural doxorubicin and an associated increase in ablation zone following RFA, a contrary effect is noted with IRE. These discrepant findings suggest that different mechanisms and synergies will need to be considered in order to select optimal adjuvants for different classes of ablation devices.

• MeSH
• doxorubicin aplikace a dávkování   analogy a deriváty   metabolismus   MeSH
• elektroporace metody   MeSH
• játra chirurgie   MeSH
• modely u zvířat MeSH
• polyethylenglykoly metabolismus   MeSH
• prasata MeSH
• radiofrekvenční ablace metody   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: To demonstrate the feasibility of directional percutaneous epicardial ablation using a partially insulated catheter. METHODS: Partially insulated catheter prototypes were tested in 12 (6 canine, 6 porcine) animal studies in two centers. Prototypes had interspersed windows to enable visualization of epicardial structures with ultrasound. Epicardial unipolar ablation and ablation between two electrodes was performed according to protocol (5-60 W power, 0-60 mls/min irrigation, 78 s mean duration). RESULTS: Of 96 epicardial ablation attempts, unipolar ablation was delivered in 53.1%. Electrogram evidence of ablation, when analyzable, occurred in 75 of 79 (94.9%) therapies. Paired pre/post-ablation pacing threshold (N = 74) showed significant increase in pacing threshold post-ablation (0.9 to 2.6 mA, P < .0001). Arrhythmias occurred in 18 (18.8%) therapies (11 ventricular fibrillation, 7 ventricular tachycardia), mainly in pigs (72.2%). Coronary artery visualization was variably successful. No phrenic nerve injury was noted during or after ablation. Furthermore, there were minimal pericardial changes with ablation. CONCLUSIONS: Epicardial ablation using a partially insulated catheter to confer epicardial directionality and protect the phrenic nerve seems feasible. Iterations with ultrasound windows may enable real-time epicardial surface visualization thus identifying coronary arteries at ablation sites. Further improvements, however, are necessary.

• MeSH
• design vybavení * MeSH
• katetrizační ablace přístrojové vybavení   metody   MeSH
• komorová tachykardie diagnostické zobrazování   chirurgie   MeSH
• modely nemocí na zvířatech MeSH
• náhodné rozdělení MeSH
• nervus phrenicus zranění   MeSH
• peroperační komplikace prevence a kontrola   MeSH
• plocha pod křivkou MeSH
• prasata MeSH
• psi MeSH
• senzitivita a specificita MeSH
• srdeční katétry MeSH
• studie proveditelnosti MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The aim of the study was to assess serum hyaluronic acid (HA) and transforming growth factor beta 1 (TGF-β1) concentrations: 1) to differentiate hepatic fibrosis from other forms of liver disease, and 2) for the non-invasive staging of canine liver fibrosis. We also evaluated the association between serum HA concentration and the size of the shunt vessel as an indirect marker of decreased liver clearance in patients with single congenital vascular anomaly. Forty-one healthy client-owned dogs and forty dogs diagnosed with hepatobiliary disease were enrolled in the prospective study. Patients were divided into 4 subgroups: 1) congenital portosystemic shunts (CPSS); 2) parenchymal diseases (a. mild and moderate fibrosis, b. advanced fibrosis and cirrhosis); 3) hepatic neoplasia; 4) biliary tract disorders based on thorough clinical, ultrasound and histopathological examination. Serum HA and TGF-β1 concentrations were measured using ELISA. The HA concentration was significantly increased in patients with advanced liver fibrosis/cirrhosis (P < 0.001) and CPSS (P < 0.001) compared to healthy dogs. Using a cut-off HA concentration of 135.94 ng/ml, the sensitivity and specificity for diagnosis for advanced liver fibrosis/cirrhosis was 100% (95% CI, 50.6–100) and 90.8% (95% CI, 81.6–95.7), respectively. The TGF-β1 levels did not significantly differ among groups (P = 0.180). Negligible correlation was found between serum HA concentration and the size of portosystemic shunt vessel (rs = 0.07; P = 0.831). These findings suggest that serum HA concentration is a potential non-invasive biomarker for advanced liver fibrosis and/or cirrhosis in dogs. The utility of measuring serum concentration of TGF-β1 for diagnosing canine liver fibrosis was not supported.

• MeSH
• biologické markery krev   MeSH
• biopsie metody   MeSH
• chronická hepatitida krev   veterinární   MeSH
• diferenciální diagnóza MeSH
• ELISA MeSH
• jaterní cirhóza diagnóza   krev   veterinární   MeSH
• kyselina hyaluronová * krev   MeSH
• laparoskopie metody   MeSH
• nemoci jater diagnóza   klasifikace   krev   veterinární   MeSH
• nemoci trávicího systému diagnóza   klasifikace   krev   veterinární   MeSH
• prospektivní studie MeSH
• psi MeSH
• ROC křivka MeSH
• senzitivita a specificita MeSH
• statistika jako téma MeSH
• transformující růstový faktor beta1 * krev   MeSH
• Check Tag
• psi MeSH
• Publikační typ
• práce podpořená grantem MeSH

INTRODUCTION: Epicardial defibrillation systems currently require surgical access. We aimed to develop a percutaneous defibrillation system with partially-insulated epicardial coils to focus electrical energy on the myocardium and prevent or minimize extra-cardiac stimulation. METHODS: We tested 2 prototypes created for percutaneous introduction into the pericardial space via a steerable sheath. This included a partially-insulated defibrillation coil and a defibrillation mesh with a urethane balloon acting as an insulator to the face of the mesh not in contact with the epicardium. The average energy associated with a chance of successful defibrillation 75% of the time (ED75) was calculated for each experiment. RESULTS: Of 16 animal experiments, 3 pig experiments had malfunctioning mesh prototypes such that results were unreliable; these were excluded. Therefore, 13 animal experiments were analyzed - 6 canines (29.8±4.0kg); 7 pigs (41.1±4.4kg). The overall ED75 was 12.8±6.7J (10.9±9.1J for canines; 14.4±3.9J in pigs [P=0.37]). The lowest ED75 obtained in canines was 2.5J while in pigs it was 9.5J. The lowest energy resulting in successful defibrillation was 2J in canines and 5J in pigs. There was no evidence of coronary vessel injury or trauma to extra-pericardial structures. CONCLUSION: Percutaneous, epicardial defibrillation using a partially insulated coil is feasible and appears to be associated with low defibrillation thresholds. Focusing insulation may limit extra-cardiac stimulation and potentially lower energy requirements for efficient defibrillation.

• Publikační typ
• časopisecké články MeSH

• MeSH
• kardiovaskulární nemoci veterinární   MeSH
• kastrace škodlivé účinky   veterinární   MeSH
• kočky MeSH
• komorbidita * MeSH
• krmivo pro zvířata MeSH
• muskuloskeletální nemoci veterinární   MeSH
• nadváha veterinární   MeSH
• obezita * epidemiologie   komplikace   veterinární   MeSH
• pouto mezi člověkem a zvířetem MeSH
• psi MeSH
• rizikové faktory * MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• přehledy MeSH

Study trying to create safe methodology of irreversible electroporation of locally advanced pancreatic cancer and to compare the clinical effect of this aproach to another cryoablative method, radiofrequency ablation.

Studie, jejímž cílem je vypracovat metodiku ireverzibilní elektroporace lokálně pokročilých maligních nádorů pankreatu a srovnat klinický efekt této metody s další cytoredukční metodou, radiofrekvenční ablací.

• MeSH
• anastomóza chirurgická MeSH
• cytoredukční chirurgie MeSH
• elektroporace MeSH
• katetrizační ablace MeSH
• nádory slinivky břišní chirurgie   MeSH
• počítačová rentgenová tomografie MeSH
• pooperační péče MeSH
• výsledek terapie MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• gastroenterologie
• onkologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR