Tacrine, the first approved drug against Alzheimer's disease (AD), was withdrawn from clinical use due to serious adverse effects. The main concern was the human hepatotoxicity, stemming probably from the liver biotransformation and clinically manifested as hepatocellular necrosis, and lobular hepatitis. Concerning the biotransformation, 7-OH-tacrine metabolite is generally suspected of being a precursor of toxic quinone methide, which binds to intracellular -SH proteins and/or depletes intracellular glutathione, and by that probably causes the hepatotoxicity. However, to study these toxic effects, proper animal model is needed to monitor the interspecies differences of metabolism. To fully describe in vivo ADMET parameters of tacrine, five experimental pigs (Sus scrofa f. domestica), as the most physiologically human-like in vivo model showing similar tacrine biotransformation, were used. We studied tacrine and its metabolites ADMET characteristics after both acute i.g. single dose and chronic 42 days p.o daily dose administration of 200 mg of tacrine. Tacrine and its two major metabolites show Tmax in plasma of 360 min, so the absorption is much slower than in human (Tmax = 120 min) and are primarily distributed to the gastro-intestinal tract and CNS. Furthermore, due to the lower activity of CYP1A2 in pigs, tacrine is biotransformed much less efficiently than in humans. This study showed that tacrine accumulates only in adipose tissue, and organ histology and plasma biochemistry assessment revealed no signs of hepatotoxicity even after chronic tacrine administration. Pigs are therefore an unsuitable human-like animal model for evaluating tacrine toxicity.

• MeSH
• Biotransformation MeSH
• Cholinesterase Inhibitors toxicity   pharmacokinetics   MeSH
• Liver * drug effects   metabolism   pathology   MeSH
• Chemical and Drug Induced Liver Injury * metabolism   pathology   MeSH
• Humans MeSH
• Swine MeSH
• Sus scrofa MeSH
• Tacrine * pharmacokinetics   toxicity   metabolism   analogs & derivatives   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

There is increasing pressure on meat producers worldwide due to the need for higher yields and improved meat quality. This is why anabolic androgenic steroids (AAS) have been widely used in most countries, due to their ability to accelerate animal muscle growth. However, out of concern for their side effects, EU states have banned their use and implemented control mechanisms. But they are reaching their limits, and therefore, it is necessary to look for new ways and investigate the mechanism of action of AAS on muscle tissue. This study replicated the administration of banned AAS (testosterone, nandrolone and their combination) and observed their effect on pig muscle. The pig model was purposely chosen for the study, as no such research has been carried out on this species. At the same time, pork is one of the most consumed meats in Europe. It focused on histological changes in muscle structure, specifically the size of muscle fibres and the number of satellite cells per muscle fibre. Furthermore, ultrastructural changes in muscle fibres, the diameter of myofibrils, the number of myofibrils per area, the distance between myofibrils and the size of sarcomeres were examined. The results using the techniques of histology, fluorescent labelling and transmission electron microscopy showed that, after the application of AAS, there is an increase in the diameter of muscle fibres, an increase in the diameter of myofibrils, a decrease in the number of myofibrils per surface area and, in the case of testosterone, an increase in the distance between myofibrils and an increase in the length of sarcomeres. There was also a significant increase in the number of satellite cells per muscle fibre. The detected statistically significant differences between control and experimental groups provide evidence that selected histological parameters could be additional mechanisms for detecting the presence of AAS in pork meat in the future.

• MeSH
• Anabolic Agents * pharmacology   MeSH
• Muscle Fibers, Skeletal * drug effects   ultrastructure   MeSH
• Muscle, Skeletal drug effects   anatomy & histology   ultrastructure   MeSH
• Myofibrils * drug effects   ultrastructure   MeSH
• Nandrolone * pharmacology   MeSH
• Swine anatomy & histology   MeSH
• Sarcomeres drug effects   ultrastructure   MeSH
• Satellite Cells, Skeletal Muscle drug effects   ultrastructure   MeSH
• Testosterone * pharmacology   MeSH
• Microscopy, Electron, Transmission veterinary   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: The effect of dexmedetomidine on regional splanchnic blood flow remain unclear. OBJECTIVES: We hypothesized, that there is no difference in regional rectal perianastomotic perfusion and oxygenation when using non-opioid dexmedetomidine-isoflurane anesthesia when compared to fentanyl-isoflurane anesthesia. METHODS: Ten female pigs were randomly divided into two groups (Dexmedetomidine, DEX, Fentanyl, FNT). Analgesia was provided by either dexmedetomidine (0.7-1.0 μg/kg/h) or fentanyl (6-10 μg/kg/h). The model of rectosigmoid resection in pigs was used. Two combined Laser Doppler flowmetry (LDF) and oxymetry probes were fixed on the antimesenterial site of the rectosigmoid, one orally and the second distally to resection zone. At the end of the experiment all animals were woken up and extubated. The healing of the anastomosis was controlled seven days after the operation. RESULTS: All experimental animals were hemodynamically stable throughout the experiment. No anastomotic leakage was detected. All animals survived until the seventh postoperative day. In the DEX group the median of the LDF signal on aboral site at the end of experiment was 35% (23-49%), in FNT group the median of the LDF signal was 19% (12-28%), which was statistically significantly lower (p < 0,05). CONCLUSIONS: This study has shown some protective effects of dexmedetomidine-isoflurane based anesthesia on perianastomotic microcirculation when compared to fentanyl-isoflurane based anesthesia.

• MeSH
• Anastomosis, Surgical methods   MeSH
• Anesthesia methods   MeSH
• Dexmedetomidine * pharmacology   MeSH
• Fentanyl * pharmacology   MeSH
• Colorectal Surgery methods   MeSH
• Swine MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

The effects of a large arteriovenous fistula (AVF) on pulmonary perfusion remains to be elucidated. We aimed to study, for the first time, the real-time acute effects of a large AVF on regional distribution of pulmonary perfusion in a novel porcine model. Ten healthy swine under general anesthesia were studied. AVF was created by the connection of femoral artery and femoral vein using high-diameter perfusion cannulas. The AVF was closed and after 30 min of stabilization the first values were recorded. The fistula was then opened, and new data were collected after reaching stable state. Continuous hemodynamic monitoring was performed throughout the protocol. The following functional images were analyzed by electrical impedance tomography (EIT): perfusion and ventilation distributions. We found an increased cardiac output and right ventricular work, which was strongly correlated to an increased pulmonary artery mean pressure (r=0.878, P=0.001). The ventral/dorsal ratio of pulmonary perfusion decreased from 1.9+/-1.0 to 1.5+/-0.7 (P=0.025). The percentage of total pulmonary blood flow through the dorsal lung region increased from 38.6+/-11.7 to 42.2+/-10.4 (P=0.016). In conclusion, we have used EIT for the first time for studying the acute effects of a large AVF on regional distribution of pulmonary perfusion in a novel porcine model. In this new experimental model of hyperkinetic circulation caused by AVF, we documented an increased percentage of total pulmonary blood flow through the dorsal lung region and a more homogeneous perfusion distribution. Key words Arteriovenous fistula, Hyperkinetic circulation, Tissue perfusion, Animal model, Pulmonary blood flow.

• MeSH
• Pulmonary Artery diagnostic imaging   physiopathology   MeSH
• Arteriovenous Fistula physiopathology   diagnostic imaging   MeSH
• Arteriovenous Shunt, Surgical MeSH
• Lung blood supply   diagnostic imaging   MeSH
• Pulmonary Circulation * physiology   MeSH
• Swine MeSH
• Femoral Vein diagnostic imaging   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: The pathophysiology of sepsis-induced acute kidney injury remains elusive. Although mitochondrial dysfunction is often perceived as the main culprit, data from preclinical models yielded conflicting results so far. The aim of this study was to assess the immune-metabolic background of sepsis-associated renal dysfunction using sequential biopsy approach with mitochondria function evaluation in a large clinically relevant porcine models mimicking two different paces and severity of sepsis and couple this approach with traditional parameters of renal physiology. METHODS: In this randomized, open-label study, 15 anaesthetized, mechanically ventilated and instrumented (renal artery flow probe and renal vein catheter) pigs were randomized in two disease severity groups-low severity (LS) sepsis (0.5 g/kg of autologous faeces intraperitoneally) and high severity (HS) sepsis (1 g/kg of autologous faeces intraperitoneally). Sequential cortical biopsies of the left kidney were performed and a pyramid-shaped kidney specimen with cortex, medulla and renal papilla was resected and processed at the end of the experiment. Oxygraphic data and western blot analysis of proteins involved in mitochondrial biogenesis and degradation were obtained. RESULTS: In contrast to increased mitochondrial activity observed in LS sepsis, a significant decrease in the oxidative phosphorylation capacity together with an increase in the respiratory system uncoupling was observed during the first 24 h after sepsis induction in the HS group. Those changes preceded alterations of renal haemodynamics. Furthermore, serum creatinine rose significantly during the first 24 h, indicating that renal dysfunction is not primarily driven by haemodynamic changes. Compared to cortex, renal medulla had significantly lower oxidative phosphorylation capacity and electron-transport system activity. PGC-1-alfa, a marker of mitochondrial biogenesis, was significantly decreased in HS group. CONCLUSIONS: In this experimental model, unique sequential tissue data show that the nature and dynamics of renal mitochondrial responses to sepsis are profoundly determined by the severity of infectious challenge and resulting magnitude of inflammatory insult. High disease severity is associated with early and stepwise progression of mitochondria dysfunction and acute kidney injury, both occurring independently from later renal macro-haemodynamic alterations. Our data may help explain the conflicting results of preclinical studies and suggest that sepsis encompasses a very broad spectrum of sepsis-induced acute kidney injury endotypes.

• Publication type
• Journal Article MeSH

BACKGROUND: Adrenaline (ADR) is a cornerstone of advanced life support (ALS) in cardiac arrest (CA), although its neurologically favourable survival outcomes remain unclear. ADR increases coronary perfusion pressure (CPP), with levels >15 mmHg associated with successful defibrillation. This study aimed to elucidate the relationship between ADR, myocardial microvascular blood flow, and resuscitation outcomes using a porcine CA model simulating refractory ventricular fibrillation (VF). METHODS: This study involved 24 domestic pigs. After instrumentation, intubation, and baseline measurements, the animals were randomised into the ADR or control (saline) groups. VF was induced, and cardiopulmonary resuscitation was initiated using continuous mechanical chest compressions and ventilation. ADR or saline was administered following ALS guidelines. After 21 min of ALS, defibrillation was performed. Continuous measurements of arterial and venous blood pressures using an electrocardiogram and index of myocardial resistance (IMR) and transit mean time (Tmn) 1 min before and after each injection or peak blood pressure were recorded and compared between the groups. CPP-IMR, amplitude spectrum area (AMSA)-IMR, CPP-Tmn, and AMSA-Tmn correlations were assessed. RESULTS: Compared with six animals in the control group, three in the ADR group achieved a return of spontaneous circulation. No difference was observed in IMR or AMSA; however, significant increases in CPP and arterial end-diastolic blood pressure were observed at several time points. Tmn differed between groups only at two time points. CONCLUSION: Repeated ADR doses during prolonged ALS simulating refractory VF did not improve myocardial microvascular blood flow, as measured using IMR, despite leading to an increase in CPP.

• Publication type
• Journal Article MeSH

BACKGROUND/AIMS: The functional lumen imaging probe (FLIP) relies on the principle of impedance planimetry that enables direct measurement of intraluminal pressure, cross-sectional areas, and wall biomechanical properties. The aim of our pilot project was to introduce this method to assess function of the lower oesophageal sphincter and pyloric muscle in experimental pigs. METHODS: All measurements were accomplished in one session in six adult female pigs (mean weight 34.2 ± 3.6 kg), using the EndoFLIP 1.0 System with EndoFLIP catheters. Five major parameters were evaluated: balloon pressure (mm Hg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mm Hg), and zone compliance (mm3/mm Hg). RESULTS: In total, 180 readings were successfully accomplished. Most of the measured values were nearing lower average figures for the lower oesophageal sphincter, and upper average figures for the pylorus in healthy humans. The porcine pyloric sphincter is composed of the Torus pyloricus. It serves as a study "gatekeeper" between the stomach and D1 duodenum, thus explaining higher pyloric readings. There was a clear trend for increasing values of CSA (cross-sectional area), diameter, and balloon pressure with increased filling balloon volumes. However, the sphincter distensibility did not change with increasing filling volumes, either for the lower oesophageal sphincter or pylorus. CONCLUSION: Endoscopic functional luminal planimetry in experimental pigs is feasible, both for the lower oesophageal sphincter and the pylorus. This is an important starting point for future experimental endoscopic trials and pharmacology studies.

• MeSH
• Esophageal Sphincter, Lower * physiology   diagnostic imaging   MeSH
• Electric Impedance * MeSH
• Pilot Projects MeSH
• Swine MeSH
• Pylorus * MeSH
• Pressure MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Background/Objectives: Tacrine is a centrally active non-competitive reversible acetylcholinesterase inhibitor. It also exerts antagonising activity against N-methyl-D-aspartate receptors. Tacrine was approved for the treatment of Alzheimer's disease in 1993, but was withdrawn from clinical use in 2013 because of its hepatotoxicity and gastrointestinal side effects. Nevertheless, tacrine is currently facing a renewed wave of interest primarily due to several new tacrine-incorporated hybrids and derivates. There were two specific aims for this study: firstly, to explain the mechanisms of the adverse action of tacrine, as a distinctive example of a highly effective acetylcholinesterase inhibitor; and secondly to check whether luminal impedance planimetry is feasible for preclinical testing of possible side effects of compounds potentially toxic to the gastrointestinal tract. Methods: Six experimental pigs were used as the animal model in this study. Five major parameters were evaluated: luminal pressure (mmHg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mmHg), and zone compliance (mm3/mmHg). All measurements were performed before and 360 min after intragastric administration of 200 mg tacrine (at the porcine tacrine Tmax). Results: This study consistently demonstrated an increase in luminal pressure (a directly measured indicator) for the particular balloon filling volumes used, and inversely a reciprocal decrease in the other parameters after tacrine administration. Conclusions: Endoscopic luminal impedance planimetry is a feasible method to evaluate functional response of the lower oesophageal sphincter to tacrine in experimental pigs. Tacrine did not compromise the function of the lower oesophageal sphincter either toward oesophageal spasms or, in contrast, decreased competence of the lower oesophageal sphincter.

• Publication type
• Journal Article MeSH

OBJECTIVES: Submental fullness has been associated with being perceived as unattractive. Technology combining radiofrequency and muscle stimulation offers submental contouring through fat reduction, muscle stimulation, and skin tightening. This study aims to demonstrate the effectiveness and safety of fat reduction aspect with a novel submentum applicator delivering HIFES and synchronized radiofrequency+ (RF+) energies. MATERIALS AND METHODS: Six white pigs (sus scrofa domesticus, n = 6, 60-80 kg) were recruited for this study, five in the active group (n = 5) received four treatments on the abdominal area, one sow served as a control (n = 1). Ultrasound, histological, and RT-qPCR methods were used as evaluation methods. RESULTS: Fat thickness decreased at 1 month by -17.35% and at 2 month by 31.40%. Proapoptotic caspase-9 gene expression increased (at 1 h, 6 h, 24 h to +43.45%, +21.22%, -8.36%), as well as caspase-3 (+15.28%, +21.77%, -6.71%), while bcl2l1 activity decreased (-11.46% at 1 h, -17.02% at 6 h, -3.9% at 24 h). While the AI in the control animal had minimal change (at 1 h -0.08%, at 6 h -0.09%, and at 24 h -0.025%), the active group's AI increased from the baseline of 9.14 to 44.85 at 1 h (+391%), peaked at 6 h to 53.50 (+485%), and at 24 h to 38.17 (+318%). CONCLUSION: The study results indicate the efficacy and safety of subcutaneous fat reduction following the novel technology combining HIFES and RF+ energies, designed to target small localized areas.

• MeSH
• High-Intensity Focused Ultrasound Ablation methods   MeSH
• Body Contouring methods   MeSH
• Lipectomy methods   instrumentation   MeSH
• Models, Animal MeSH
• Subcutaneous Fat * MeSH
• Swine MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Anastomotický leak a poruchy pasáže zažívacím traktem způsobené tvorbou peritoneálních adhezí patří mezi zásadní pooperační komplikace v kolorektální chirurgii. Na trhu nejsou k dispozici materiály, které by tyto komplikace spolehlivě eliminovaly. Cílem projektu je vyvinout unikátní dvouvrstvý nanovlákenný materiál s odlišnými vlastnostmi jednotlivých stran pro krytí chirurgických anastomóz. Materiál se bude skládat ze syntetických biokompatibilních a biodegradabilních polymerů a bude připraven kombinací electrospinningu a electrosprayingu na NanospiderTM. Vnitřní polymerní vlákna přilnou k anastomóze a podpoří hojení. Morfologie vnější antiadhezivní strany bude inspirována nativním superhydrofobním lotosovým povrchem a bude sloužit jako prevence adhezí. Materiály budou analyzovány in vitro testy za použití NIH/3T3 fibroblastů. Přilnavost k tkáni bude testována mechanicky. Funkce materiálu bude popsána na prasečím modelu komplikovaného hojení anastomózy na tračníku s třítýdenní observací zvířat zakončenou systematickým hodnocením peritoneálních adhezí a kvality anastomózy.; Anastomotic leakage and gastrointestinal obstruction due to formation of peritoneal adhesions are major postoperative complications in colorectal surgery. There are no available materials on the market capable of preventing such complications. The aim of the project is to develop a unique double-layered nanofibrous material to cover the intestinal anastomoses. The material will be composed of synthetic biocompatible and biodegradable polymers and prepared by combining the electrospinning and the electrospraying via NanospiderTM. The inner polymeric fibers will adhere to anastomosis and support healing. The outer anti-adhesive side will be inspired by the natural superhydrophobic lotus leaf structure and thus prevent the adhesions. The materials will be assessed in vitro using NIH/3T3 fibroblasts. The adhesion to tissue will be tested mechanically. The functionality of the material will be described in experimental model of complicated healing of colonic anastomosis on pig with three weeks observation period concluded with evaluation of peritoneal adhesions and anastomotic healing.

• Keywords
• biokompatibilita, biocompatibility, nanovlákna, nanofibers, biodegradabilita, biodegradability, gastrointestinální anastomóza, anastomotický leak, pooperační adheze, abdominální chirurgie, superhydrofobicita, gastrointestinal anastomosis, anastomotic leakage, postoperative adhesion, abdominal surgery, superhydrophobic surface,

• NML Publication type
• závěrečné zprávy o řešení grantu AZV MZ ČR