WorldWideScience

Sample records for porcine liver model

  1. Bloodless laparoscopic liver resection using radiofrequency thermal energy in the porcine model.

    Science.gov (United States)

    Tsalis, Konstantinos; Blouhos, Konstantinos; Vasiliadis, Konstantinos; Kalfadis, Stavros; Tsachalis, Theodoros; Savvas, Ioannis; Betsis, Dimitrios

    2007-02-01

    The aim of this study was to assess the feasibility and safety of laparoscopic hepatectomy using radiofrequency (RF) thermal energy in a porcine model. Fifteen female domestic pigs weighing 29.3 kg (range 25 to 35 kg) were used. Five transversal abdominal incisions (3 of 1 cm and 2 of 0.5 cm) were made for the introduction of the video camera and the other laparoscopic instruments. With the porta hepatis not clamped, the liver was inspected and the preferred lobe each time was divided using RF (cool-tip electrode 3 cm) with minimum bleeding. Serum liver enzymes and blood counts were drawn pre and postoperatively. All animals were killed after 1 week. The mean time of the procedures was 119 minutes (range 100 to 155 min). There were no intraoperative complications. Mean blood loss was 27 mL (range 5 to 60 mL), and the mass of the resected specimen was 132.5 g (range 65 to 305 g). There were no postoperative complications or deaths. Bloodless laparoscopic hepatectomy was technically feasible and safe in the porcine model using cool-tip electrode and 500-kHz RF Generator.

  2. CT-based liver volumetry in a porcine model: impact on clinical volumetry prior to living donated liver transplantation

    International Nuclear Information System (INIS)

    Frericks, B.B.J.; Kiene, T.; Stamm, G.; Shin, H.; Galanski, M.

    2004-01-01

    Purpose: Exact preoperative determination of the liver volume is of great importance prior to hepatobiliary surgery, especially in living donated liver transplantation (LDLT). In the current literature, a strong correlation between preoperatively calculated and intraoperatively measured liver volumes has been described. Such accuracy seems questionable, primarily due to a difference in the perfusion state of the liver in situ versus after explantation. Purpose of the study was to asses the influence of the perfusion state on liver volume and the validity of the preoperative liver volumetry prior to LDLT. Methods: In an experimental study, 20 porcine livers were examined. The livers were weighted and their volumes were determined by water displacement prior and after fluid infusion to achieve a pressure physiologically found in the liver veins. The liver volumes in the different perfusion states were calculated based on CT-data. The calculated values were compared with the volume measured by water displacement and the weight of the livers. Results: Assessment of calculated CT volumes and water displacements at identical perfusion states showed a tight correlation and differed on average by 4 ± 5%. However, livers before and after fluid infusion showed a 33 ± 8% (350 ± 150 ml) difference in volume. Conclusion: CT-volumetry acquires highly accurate data as confirmed by water displacement studies. However, the perfusion state has major impact on liver volume, which has to be accounted for in clinical use. (orig.) [de

  3. Development of an invasively monitored porcine model of acetaminophen-induced acute liver failure

    Directory of Open Access Journals (Sweden)

    Howie Forbes

    2010-03-01

    Full Text Available Abstract Background The development of effective therapies for acute liver failure (ALF is limited by our knowledge of the pathophysiology of this condition, and the lack of suitable large animal models of acetaminophen toxicity. Our aim was to develop a reproducible invasively-monitored porcine model of acetaminophen-induced ALF. Method 35kg pigs were maintained under general anaesthesia and invasively monitored. Control pigs received a saline infusion, whereas ALF pigs received acetaminophen intravenously for 12 hours to maintain blood concentrations between 200-300 mg/l. Animals surviving 28 hours were euthanased. Results Cytochrome p450 levels in phenobarbital pre-treated animals were significantly higher than non pre-treated animals (300 vs 100 pmol/mg protein. Control pigs (n = 4 survived 28-hour anaesthesia without incident. Of nine pigs that received acetaminophen, four survived 20 hours and two survived 28 hours. Injured animals developed hypotension (mean arterial pressure; 40.8 +/- 5.9 vs 59 +/- 2.0 mmHg, increased cardiac output (7.26 +/- 1.86 vs 3.30 +/- 0.40 l/min and decreased systemic vascular resistance (8.48 +/- 2.75 vs 16.2 +/- 1.76 mPa/s/m3. Dyspnoea developed as liver injury progressed and the increased pulmonary vascular resistance (636 +/- 95 vs 301 +/- 26.9 mPa/s/m3 observed may reflect the development of respiratory distress syndrome. Liver damage was confirmed by deterioration in pH (7.23 +/- 0.05 vs 7.45 +/- 0.02 and prothrombin time (36 +/- 2 vs 8.9 +/- 0.3 seconds compared with controls. Factor V and VII levels were reduced to 9.3 and 15.5% of starting values in injured animals. A marked increase in serum AST (471.5 +/- 210 vs 42 +/- 8.14 coincided with a marked reduction in serum albumin (11.5 +/- 1.71 vs 25 +/- 1 g/dL in injured animals. Animals displayed evidence of renal impairment; mean creatinine levels 280.2 +/- 36.5 vs 131.6 +/- 9.33 μmol/l. Liver histology revealed evidence of severe centrilobular necrosis

  4. Real-time ultrasound imaging of irreversible electroporation in a porcine liver model adequately characterizes the zone of cellular necrosis.

    Science.gov (United States)

    Schmidt, Carl R; Shires, Peter; Mootoo, Mary

    2012-02-01

      Irreversible electroporation (IRE) is a largely non-thermal method for the ablation of solid tumours. The ability of ultrasound (US) to measure the size of the IRE ablation zone was studied in a porcine liver model.   Three normal pig livers were treated in vivo with a total of 22 ablations using IRE. Ultrasound was used within minutes after ablation and just prior to liver harvest at either 6 h or 24 h after the procedure. The area of cellular necrosis was measured after staining with nitroblue tetrazolium and the percentage of cell death determined by histomorphometry.   Visible changes in the hepatic parenchyma were apparent by US after all 22 ablations using IRE. The mean maximum diameter of the ablation zone measured by US during the procedure was 20.1 ± 2.7 mm. This compared with a mean cellular necrosis zone maximum diameter of 20.3 ± 2.9 mm as measured histologically. The mean percentage of dead cells within the ablation zone was 77% at 6 h and 98% at 24 h after ablation.   Ultrasound is a useful modality for measuring the ablation zone within minutes of applying IRE to normal liver tissue. The area of parenchymal change measured by US correlates with the area of cellular necrosis. © 2011 International Hepato-Pancreato-Biliary Association.

  5. New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

    International Nuclear Information System (INIS)

    Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun

    2017-01-01

    To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments

  6. New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-01-15

    To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments.

  7. Xenotransplantation of neonatal porcine liver cells.

    Science.gov (United States)

    Garkavenko, O; Emerich, D F; Muzina, M; Muzina, Z; Vasconcellos, A V; Ferguson, A B; Cooper, I J; Elliott, R B

    2005-01-01

    Xenotransplantation of porcine liver cell types may provide a means of overcoming the shortage of suitable donor tissues to treat hepatic diseases characterized by inherited inborn errors of metabolism or protein production. Here we report the successful isolation, culture, and xenotransplantation of liver cells harvested from 7- to 10-day-old piglets. Liver cells were isolated and cultured immediately after harvesting. Cell viability was excellent (>90%) over the duration of the in vitro studies (3 weeks) and the cultured cells continued to significantly proliferate. These cells also retained their normal secretory and metabolic capabilities as determined by continued release of albumin, factor 8, and indocyanin green (ICG) uptake. After 3 weeks in culture, porcine liver cells were loaded into immunoisolatory macro devices (Theracyte devices) and placed into the intraperitoneal cavity of immunocompetant CD1 mice. Eight weeks later, the devices were retrieved and the cells analyzed for posttransplant determinations of survival and function. Post mortem analysis confirmed that the cell-loaded devices were biocompatible, and were well-tolerated without inducing any notable inflammatory reaction in the tissues immediately surrounding the encapsulated cells. Finally, the encapsulated liver cells remained viable and functional as determined by histologic analyses and ICG uptake/release. The successful harvesting, culturing, and xenotransplantation of functional neonatal pig liver cells support the continued development of this approach for treating a range of currently undertreated or intractable hepatic diseases.

  8. Robotically Assisted Sonic Therapy as a Noninvasive Nonthermal Ablation Modality: Proof of Concept in a Porcine Liver Model.

    Science.gov (United States)

    Smolock, Amanda R; Cristescu, Mircea M; Vlaisavljevich, Eli; Gendron-Fitzpatrick, Annette; Green, Chelsey; Cannata, Jonathan; Ziemlewicz, Timothy J; Lee, Fred T

    2018-05-01

    Purpose To determine the feasibility of creating a clinically relevant hepatic ablation (ie, an ablation zone capable of treating a 2-cm liver tumor) by using robotically assisted sonic therapy (RAST), a noninvasive and nonthermal focused ultrasound therapy based on histotripsy. Materials and Methods This study was approved by the institutional animal use and care committee. Ten female pigs were treated with RAST in a single session with a prescribed 3-cm spherical treatment region and immediately underwent abdominal magnetic resonance (MR) imaging. Three pigs (acute group) were sacrificed immediately following MR imaging. Seven pigs (chronic group) were survived for approximately 4 weeks and were reimaged with MR imaging immediately before sacrifice. Animals underwent necropsy and harvesting of the liver for histologic evaluation of the ablation zone. RAST ablations were performed with a 700-kHz therapy transducer. Student t tests were performed to compare prescribed versus achieved ablation diameter, difference of sphericity from 1, and change in ablation zone volume from acute to chronic imaging. Results Ablation zones had a sphericity index of 0.99 ± 0.01 (standard deviation) (P < .001 vs sphericity index of 1). Anteroposterior and transverse dimensions were not significantly different from prescribed (3.4 ± 0.7; P = .08 and 3.2 ± 0.8; P = .29, respectively). The craniocaudal dimension was significantly larger than prescribed (3.8 ± 1.1; P = .04), likely because of respiratory motion. The central ablation zone demonstrated complete cell destruction and a zone of partial necrosis. A fibrous capsule surrounded the ablation zone by 4 weeks. On 4-week follow-up images, ablation zone volumes decreased by 64% (P < .001). Conclusion RAST is capable of producing clinically relevant ablation zones in a noninvasive manner in a porcine model. © RSNA, 2018.

  9. Liver repair and hemorrhage control by using laser soldering of liquid albumin in a porcine model.

    Science.gov (United States)

    Wadia, Y; Xie, H; Kajitani, M

    2000-01-01

    We evaluated laser soldering by using liquid albumin for welding liver injuries. Major liver trauma has a high mortality because of immediate exsanguination and a delayed morbidity from septicemia, peritonitis, biliary fistulae, and delayed secondary hemorrhage. Eight laceration (6 x 2 cm) and eight nonanatomic resection injuries (raw surface, 6 x 2 cm) were repaired. An 805-nm laser was used to weld 50% liquid albumin-indocyanine green solder to the liver surface, reinforcing it with a free autologous omental scaffold. The animals were heparinized and hepatic inflow occlusion was used for vascular control. All 16 soldering repairs were evaluated at 3 hours. All 16 laser mediated liver repairs had minimal blood loss as compared with the suture controls. No dehiscence, hemorrhage, or bile leakage was seen in any of the laser repairs after 3 hours. Laser fusion repair of the liver is a reliable technique to gain hemostasis on the raw surface as well as weld lacerations. Copyright 2000 Wiley-Liss, Inc.

  10. Liver repair and hemorrhage control using laser soldering of liquid albumin in a porcine model

    Science.gov (United States)

    Wadia, Yasmin; Xie, Hua; Kajitani, Michio; Gregory, Kenton W.; Prahl, Scott A.

    2000-05-01

    The purpose of this study was to evaluate laser soldering using liquid albumin for welding liver lacerations and sealing raw surfaces created by segmental resection of a lobe. Major liver trauma has a high mortality due to immediate exsanguination and a delayed morbidity and mortality from septicemia, peritonitis, biliary fistulae and delayed secondary hemorrhage. Eight laceration injuries (6 cm long X 2 cm deep) and eight non-anatomical resection injuries (raw surface 6 cm X 2 cm) were repaired. An 805 nm laser was used to weld 53% liquid albumin-ICG solder to the liver surface, reinforcing it with a free autologous omental scaffold. The animals were heparinized to simulate coagulation failure and hepatic inflow occlusion was used for vascular control. For both laceration and resection injuries, eight soldering repairs each were evaluated at three hours. A single suture repair of each type was evaluated at three hours. All 16 laser mediated liver repairs were accompanied by minimal blood loss as compared to the suture controls. No dehiscence, hemorrhage or bile leakage was seen in any of the laser repairs after three hours. In conclusion laser fusion repair of the liver is a quick and reliable technique to gain hemostasis on the cut surface as well as weld lacerations.

  11. Dietary Supplementation with Lactobacillus casei Alleviates Lipopolysaccharide-Induced Liver Injury in a Porcine Model

    Directory of Open Access Journals (Sweden)

    Di Zhao

    2017-11-01

    Full Text Available This study aims to determine whether Lactobacillus casei (L. casei could relieve liver injury in piglets challenged with lipopolysaccharide (LPS. Piglets were randomly allocated into one of the three groups: control, LPS, and L. casei. The control and LPS groups were fed a corn- and soybean meal-based diet, whereas the L. casei group was fed the basal diet supplemented with 6 × 106 cfu/g L. casei. On Day 31 of the trial, piglets in the LPS and L. casei groups received intraperitoneal administration of LPS (100 µg/kg body weight, while the control group received the same volume of saline. Blood and liver samples were collected for analysis. Results showed that L. casei supplementation decreased the feed/gain ratio (p = 0.027 and diarrhea incidence (p < 0.001, and attenuated LPS-induced liver histomorphological abnormalities. Compared with the control group, LPS challenge dramatically increased glutamyl transpeptidase activity (p = 0.001 in plasma as well as the concentrations of Interleukin 6 (IL-6 (p = 0.048, Tumor necrosis factor-alpha (TNF-α (p = 0.041, and Malondialdehyde (MDA (p = 0.001 in the liver, while decreasing the hepatic SOD activity. LPS also increased (p < 0.05 the mRNA levels for IL-6, IL-8, TNF-α, Toll-like receptors 4 (TLR4, Nuclear factor κB (NF-κB and Heat shock protein 70 (HSP70 in the liver. The adverse effects of LPS challenge were ameliorated by L. casei supplementation. In conclusion, dietary L. casei alleviates LPS-induced liver injury via reducing pro-inflammatory cytokines and increasing anti-oxidative capacity.

  12. Formation of reactive aldehydes (MDA, HHE, HNE) during the digestion of cod liver oil: comparison of human and porcine in vitro digestion models.

    Science.gov (United States)

    Tullberg, Cecilia; Larsson, Karin; Carlsson, Nils-Gunnar; Comi, Irene; Scheers, Nathalie; Vegarud, Gerd; Undeland, Ingrid

    2016-03-01

    In this work, we investigated lipid oxidation of cod liver oil during gastrointestinal (GI) digestion using two types of in vitro digestion models. In the first type of model, we used human GI juices, while we used digestive enzymes and bile from porcine origin in the second type of model. Human and porcine models were matched with respect to factors important for lipolysis, using a standardized digestion protocol. The digests were analysed for reactive oxidation products: malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and 4-hydroxy-trans-2-hexenal (HHE) by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS), and for free fatty acids (FFA) obtained during the digestion by gas chromatography-mass spectrometry (GC-MS). The formation of the oxidation products MDA, HHE, and HNE was low during the gastric digestion, however, it increased during the duodenal digestion. The formation of the oxidation products reached higher levels when digestive juices of human origin were used (60 μM of MDA, 0.96 μM of HHE, and 1.6 μM of HNE) compared to when using enzymes and bile of porcine origin (9.8, and 0.36 μM of MDA; 0.16, and 0.026 μM of HHE; 0.23, and 0.005 μM of HNE, respectively, in porcine models I and II). In all models, FFA release was only detected during the intestinal step, and reached up to 31% of total fatty acids (FA). The findings in this work may be of importance when designing oxidation oriented lipid digestion studies.

  13. Mechanics of fresh, frozen-thawed and heated porcine liver tissue.

    Science.gov (United States)

    Wex, Cora; Stoll, Anke; Fröhlich, Marlen; Arndt, Susann; Lippert, Hans

    2014-06-01

    For a better understanding of the effects of thermally altered soft tissue, the biothermomechanics of these tissues need to be studied. Without the knowledge of the underlying physical processes and the parameters that can be controlled clinically, thermal treatment of cancerous hepatic tissue or the preservation of liver grafts are based primarily on trial and error. Thus, this study is concerned with the investigation of the influence of temperature on the rheological properties and the histological properties of porcine liver. Heating previously cooled porcine liver tissue above 40 °C leads to significant, irreversible stiffness changes observed in the amplitude sweep. The increase of the complex shear module of healthy porcine liver from room temperature to 70 °C is approximately 9-fold. Comparing the temperatures -20 °C and 20 °C, no significant difference of the mechanical properties was observed. Furthermore, there is a strong relation between the mechanical and histological properties of the porcine liver. Temperatures above 40 °C destroy the collagen matrix within the liver tissue. This results in the alteration of the biomechanical properties. The time-temperature superposition principle is applied to generate temperature-dependent shift factors that can be described by a two-part exponential function model with an inflection temperature of 45 °C. Tumor ablation techniques such as heating or freezing have a significant influence on the histology of liver tissue. However, only for temperatures above body temperature an influence on the mechanical properties of hepatic tissues was noticeable. Freezing up to -20 °C did not affect the liver mechanics.

  14. Lesions in Porcine Liver Tissues Created by Continuous High Intensity Ultrasound Exposures in Vitro

    International Nuclear Information System (INIS)

    Zhang Zhe; Chen Tao; Zhang Dong

    2013-01-01

    Lesions in porcine liver tissues created by continuous high intensity focused ultrasound (HIFU) exposures in vitro are theoretically and experimentally investigated, with the transmitter moving along a linear path at a fixed speed. Numerical simulations of the lesion formation are performed based on the Khokhlov—Zabolotskaya—Kuznetov equation and the bio-heat equation. In order to verify the theoretical predictions, experiments are performed in the one-dimensional scanning mode to measure the cross-sectional area of lesions created in the in vitro porcine liver exposed to 1.01-MHz HIFU pulses with the acoustic power of 70 W. The results indicate that, compared to the traditional discrete treatment protocol, the application of a continuous scanning model can create more uniform lesions in tissues and significantly reduces the total treatment time from 47s to 30s

  15. Appraisal of the porcine kidney autotransplantation model

    NARCIS (Netherlands)

    Post, Ivo C. J. H.; Dirkes, Marcel C.; Heger, Michal; van Loon, Johannes P. A. M.; Swildens, Bas; Huijzer, Goos M.; van Gulik, Thomas M.

    2012-01-01

    Animal models are extensively used for transplantation related research, especially kidney transplantation. Porcine autotransplantation models are considered to be favorable regarding translatability to the human setting. The key determinants for translatability of the model are discussed,

  16. Porcine model of hemophilia A.

    Directory of Open Access Journals (Sweden)

    Yuji Kashiwakura

    Full Text Available Hemophilia A is a common X chromosome-linked genetic bleeding disorder caused by abnormalities in the coagulation factor VIII gene (F8. Hemophilia A patients suffer from a bleeding diathesis, such as life-threatening bleeding in the brain and harmful bleeding in joints and muscles. Because it could potentially be cured by gene therapy, subhuman animal models have been sought. Current mouse hemophilia A models generated by gene targeting of the F8 have difficulties to extrapolate human disease due to differences in the coagulation and immune systems between mice and humans. Here, we generated a porcine model of hemophilia A by nuclear transfer cloning from F8-targeted fibroblasts. The hemophilia A pigs showed a severe bleeding tendency upon birth, similar to human severe hemophiliacs, but in contrast to hemophilia A mice which rarely bleed under standard breed conditions. Infusion of human factor VIII was effective in stopping bleeding and reducing the bleeding frequency of a hemophilia A piglet but was blocked by the inhibitor against human factor VIII. These data suggest that the hemophilia A pig is a severe hemophilia A animal model for studying not only hemophilia A gene therapy but also the next generation recombinant coagulation factors, such as recombinant factor VIII variants with a slower clearance rate.

  17. How preservation time changes the linear viscoelastic properties of porcine liver.

    Science.gov (United States)

    Wex, C; Stoll, A; Fröhlich, M; Arndt, S; Lippert, H

    2013-01-01

    The preservation time of a liver graft is one of the crucial factors for the success of a liver transplantation. Grafts are kept in a preservation solution to delay cell destruction and cellular edema and to maximize organ function after transplantation. However, longer preservation times are not always avoidable. In this paper we focus on the mechanical changes of porcine liver with increasing preservation time, in order to establish an indicator for the quality of a liver graft dependent on preservation time. A time interval of 26 h was covered and the rheological properties of liver tissue studied using a stress-controlled rheometer. For samples of 1 h preservation time 0.8% strain was found as the limit of linear viscoelasticity. With increasing preservation time a decrease in the complex shear modulus as an indicator for stiffness was observed for the frequency range from 0.1 to 10 Hz. A simple fractional derivative representation of the Kelvin Voigt model was applied to gain further information about the changes of the mechanical properties of liver with increasing preservation time. Within the small shear rate interval of 0.0001-0.01 s⁻¹ the liver showed Newtonian-like flow behavior.

  18. Optimizing Perfusion-Decellularization Methods of Porcine Livers for Clinical-Scale Whole-Organ Bioengineering

    Directory of Open Access Journals (Sweden)

    Qiong Wu

    2015-01-01

    Full Text Available Aim. To refine the decellularization protocol of whole porcine liver, which holds great promise for liver tissue engineering. Methods. Three decellularization methods for porcine livers (1% sodium dodecyl sulfate (SDS, 1% Triton X-100 + 1% sodium dodecyl sulfate, and 1% sodium deoxycholate + 1% sodium dodecyl sulfate were studied. The obtained liver scaffolds were processed for histology, residual cellular content analysis, and extracellular matrix (ECM components evaluation to investigate decellularization efficiency and ECM preservation. Rat primary hepatocytes were seeded into three kinds of scaffold to detect the biocompatibility. Results. The whole liver decellularization was successfully achieved following all three kinds of treatment. SDS combined with Triton had a high efficacy of cellular removal and caused minimal disruption of essential ECM components; it was also the most biocompatible procedure for primary hepatocytes. Conclusion. We have refined a novel, standardized, time-efficient, and reproducible protocol for the decellularization of whole liver which can be further adapted to liver tissue engineering.

  19. No evidence of in vitro and in vivo porcine endogenous retrovirus infection after plasmapheresis through the AMC-bioartificial liver

    NARCIS (Netherlands)

    Di Nicuolo, Giuseppe; van de Kerkhove, Maarten-Paul; Hoekstra, Ruurdtje; Beld, Marcel G. H. M.; Amoroso, Pietro; Battisti, Sonia; Starace, Maria; di Florio, Ernesto; Scuderi, Vincenzo; Scala, Simona; Bracco, Adele; Mancini, Antonio; Chamuleau, Robert A. F. M.; Calise, Fulvio

    2005-01-01

    Background: Currently a number of bioartificial livers (BAL) based on porcine liver cells have been developed as a treatment to bridge acute liver failure patients to orthotopic liver transplantation or liver regeneration. These xenotransplantation related treatments hold the risk of infection of

  20. Bisphenol A Causes Liver Damage and Selectively Alters the Neurochemical Coding of Intrahepatic Parasympathetic Nerves in Juvenile Porcine Models under Physiological Conditions

    Directory of Open Access Journals (Sweden)

    Michael Thoene

    2017-12-01

    Full Text Available Bisphenol A (BPA is an extremely common polymer that is used in typical everyday products throughout the world, especially in food and beverage containers. Within the last ten years, it has been found that the BPA monomer tends to leach into foodstuffs, and nanogram concentrations of it may cause a variety of deleterious health effects. These health problems are very evident in developing children and in young adults. The aim of this study was to expose developing pigs to dietary BPA at both legally acceptable and ten-fold higher levels. Livers that had been exposed to BPA showed vacuolar degeneration, sinusoidal dilatation, vascular congestion and glycogen depletion that increased with exposure levels. Furthermore, the livers of these models were then examined for irregularities and double-labeled immunofluorescence was used to check the innervated hepatic samples for varying neuronal expression of selected neuronal markers in the parasympathetic nervous system (PSNS. It was found that both the PSNS and all of the neuronal markers showed increased expression, with some of them being significant even at recommended safe exposure levels. The implications are quite serious since these effects have been observed at recommended safe levels with expression increasing in-line with exposure levels. The increased neuronal markers studied here have been previously correlated with behavioral/psychological disorders of children and young adults, as well as with childhood obesity and diabetes. However, further research must be performed in order to develop a mechanism for the above-mentioned correlations.

  1. Purification and characterization of glutaryl-CoA dehydrogenase from porcine and human liver

    International Nuclear Information System (INIS)

    Lenich, A.C.

    1985-01-01

    Glutaryl-CoA dehydrogenase (GCDH) was purified from porcine liver mitochondria by pH and ammonium sulfate fractionations followed by a series of column chromatographies. The purified porcine enzyme was found by sodium dodecyl-sulfate polyacrylamide gel electrophoresis to have a subunit molecular weight of 47,800 and by gradient polyacrylamide gel electrophoresis (PAGE) to have a native molecular weight of approximately 186,000. The product of the GCDH reaction with its primary substrate, glutaryl-CoA, was investigated by radio-gas chromatography and found to be crotonyl-CoA. Alternate substrates as well as crotonyl-CoA, the glutaryl-CoA reaction end product, demonstrated competitive inhibition when incubated with (1,5- 14 C)-glutaryl-CoA in the presence of porcine GCDH. Kinetic parameters for the interaction of both ETF and glutaryl-CoA with porcine GCDH were determined. Purified porcine GCDH was used to produce an antiserum which cross-reacted with human liver GCDH with a reaction of partial identity, but proved too insensitive to detect GCDH in control human fibroblasts. As a result of these negative findings, GCDH was purified by a series of column chromatographies from human liver. The purified human enzyme was found by SDS-PAGE and gel filtration to have subunit and native molecular weights of 58,800 and 256,000 respectively

  2. CT-guided Irreversible Electroporation in an Acute Porcine Liver Model: Effect of Previous Transarterial Iodized Oil Tissue Marking on Technical Parameters, 3D Computed Tomographic Rendering of the Electroporation Zone, and Histopathology

    International Nuclear Information System (INIS)

    Sommer, C. M.; Fritz, S.; Vollherbst, D.; Zelzer, S.; Wachter, M. F.; Bellemann, N.; Gockner, T.; Mokry, T.; Schmitz, A.; Aulmann, S.; Stampfl, U.; Pereira, P.; Kauczor, H. U.; Werner, J.; Radeleff, B. A.

    2015-01-01

    PurposeTo evaluate the effect of previous transarterial iodized oil tissue marking (ITM) on technical parameters, three-dimensional (3D) computed tomographic (CT) rendering of the electroporation zone, and histopathology after CT-guided irreversible electroporation (IRE) in an acute porcine liver model as a potential strategy to improve IRE performance.MethodsAfter Ethics Committee approval was obtained, in five landrace pigs, two IREs of the right and left liver (RL and LL) were performed under CT guidance with identical electroporation parameters. Before IRE, transarterial marking of the LL was performed with iodized oil. Nonenhanced and contrast-enhanced CT examinations followed. One hour after IRE, animals were killed and livers collected. Mean resulting voltage and amperage during IRE were assessed. For 3D CT rendering of the electroporation zone, parameters for size and shape were analyzed. Quantitative data were compared by the Mann–Whitney test. Histopathological differences were assessed.ResultsMean resulting voltage and amperage were 2,545.3 ± 66.0 V and 26.1 ± 1.8 A for RL, and 2,537.3 ± 69.0 V and 27.7 ± 1.8 A for LL without significant differences. Short axis, volume, and sphericity index were 16.5 ± 4.4 mm, 8.6 ± 3.2 cm 3 , and 1.7 ± 0.3 for RL, and 18.2 ± 3.4 mm, 9.8 ± 3.8 cm 3 , and 1.7 ± 0.3 for LL without significant differences. For RL and LL, the electroporation zone consisted of severely widened hepatic sinusoids containing erythrocytes and showed homogeneous apoptosis. For LL, iodized oil could be detected in the center and at the rim of the electroporation zone.ConclusionThere is no adverse effect of previous ITM on technical parameters, 3D CT rendering of the electroporation zone, and histopathology after CT-guided IRE of the liver

  3. CT-guided Irreversible Electroporation in an Acute Porcine Liver Model: Effect of Previous Transarterial Iodized Oil Tissue Marking on Technical Parameters, 3D Computed Tomographic Rendering of the Electroporation Zone, and Histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Fritz, S., E-mail: stefan.fritz@med.uni-heidelberg.de [University Hospital Heidelberg, Department of General Visceral and Transplantation Surgery (Germany); Vollherbst, D., E-mail: dominikvollherbst@web.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Zelzer, S., E-mail: s.zelzer@dkfz-heidelberg.de [German Cancer Research Center (dkfz), Medical and Biological Informatics (Germany); Wachter, M. F., E-mail: fredericwachter@googlemail.com; Bellemann, N., E-mail: nadine.bellemann@med.uni-heidelberg.de; Gockner, T., E-mail: theresa.gockner@med.uni-heidelberg.de; Mokry, T., E-mail: theresa.mokry@med.uni-heidelberg.de; Schmitz, A., E-mail: anne.schmitz@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Aulmann, S., E-mail: sebastian.aulmann@mail.com [University Hospital Heidelberg, Department of General Pathology (Germany); Stampfl, U., E-mail: ulrike.stampfl@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Pereira, P., E-mail: philippe.pereira@slk-kliniken.de [SLK Kliniken Heilbronn GmbH, Clinic for Radiology, Minimally-invasive Therapies and Nuclear Medicine (Germany); Kauczor, H. U., E-mail: hu.kauczor@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Werner, J., E-mail: jens.werner@med.uni-heidelberg.de [University Hospital Heidelberg, Department of General Visceral and Transplantation Surgery (Germany); Radeleff, B. A., E-mail: boris.radeleff@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany)

    2015-02-15

    PurposeTo evaluate the effect of previous transarterial iodized oil tissue marking (ITM) on technical parameters, three-dimensional (3D) computed tomographic (CT) rendering of the electroporation zone, and histopathology after CT-guided irreversible electroporation (IRE) in an acute porcine liver model as a potential strategy to improve IRE performance.MethodsAfter Ethics Committee approval was obtained, in five landrace pigs, two IREs of the right and left liver (RL and LL) were performed under CT guidance with identical electroporation parameters. Before IRE, transarterial marking of the LL was performed with iodized oil. Nonenhanced and contrast-enhanced CT examinations followed. One hour after IRE, animals were killed and livers collected. Mean resulting voltage and amperage during IRE were assessed. For 3D CT rendering of the electroporation zone, parameters for size and shape were analyzed. Quantitative data were compared by the Mann–Whitney test. Histopathological differences were assessed.ResultsMean resulting voltage and amperage were 2,545.3 ± 66.0 V and 26.1 ± 1.8 A for RL, and 2,537.3 ± 69.0 V and 27.7 ± 1.8 A for LL without significant differences. Short axis, volume, and sphericity index were 16.5 ± 4.4 mm, 8.6 ± 3.2 cm{sup 3}, and 1.7 ± 0.3 for RL, and 18.2 ± 3.4 mm, 9.8 ± 3.8 cm{sup 3}, and 1.7 ± 0.3 for LL without significant differences. For RL and LL, the electroporation zone consisted of severely widened hepatic sinusoids containing erythrocytes and showed homogeneous apoptosis. For LL, iodized oil could be detected in the center and at the rim of the electroporation zone.ConclusionThere is no adverse effect of previous ITM on technical parameters, 3D CT rendering of the electroporation zone, and histopathology after CT-guided IRE of the liver.

  4. Tissue Sampling Guides for Porcine Biomedical Models.

    Science.gov (United States)

    Albl, Barbara; Haesner, Serena; Braun-Reichhart, Christina; Streckel, Elisabeth; Renner, Simone; Seeliger, Frank; Wolf, Eckhard; Wanke, Rüdiger; Blutke, Andreas

    2016-04-01

    This article provides guidelines for organ and tissue sampling adapted to porcine animal models in translational medical research. Detailed protocols for the determination of sampling locations and numbers as well as recommendations on the orientation, size, and trimming direction of samples from ∼50 different porcine organs and tissues are provided in the Supplementary Material. The proposed sampling protocols include the generation of samples suitable for subsequent qualitative and quantitative analyses, including cryohistology, paraffin, and plastic histology; immunohistochemistry;in situhybridization; electron microscopy; and quantitative stereology as well as molecular analyses of DNA, RNA, proteins, metabolites, and electrolytes. With regard to the planned extent of sampling efforts, time, and personnel expenses, and dependent upon the scheduled analyses, different protocols are provided. These protocols are adjusted for (I) routine screenings, as used in general toxicity studies or in analyses of gene expression patterns or histopathological organ alterations, (II) advanced analyses of single organs/tissues, and (III) large-scale sampling procedures to be applied in biobank projects. Providing a robust reference for studies of porcine models, the described protocols will ensure the efficiency of sampling, the systematic recovery of high-quality samples representing the entire organ or tissue as well as the intra-/interstudy comparability and reproducibility of results. © The Author(s) 2016.

  5. Porcine foetal and neonatal CYP3A liver expression

    Directory of Open Access Journals (Sweden)

    Marie Louise Hiort Hermann

    2011-05-01

    Full Text Available Human cytochrome P450 3A7 (CYP3A7 and cytochrome P450 3A4 (CYP3A4 are hepatic metabolising enzymes which participates in the biotransformation of endo- and exogenous substances in foetuses and neonates respectively. These CYP3A enzymes display an inverse relationship: CYP3A7 is the dominant enzyme in the foetal liver, whereas the expression of CYP3A4 is low. After parturition there is a shift in the expression, thus CYP3A7 is down regulated, while the level of CYP3A4 gradually increases and becomes the dominant metabolising CYP3A enzyme in the adult. The minipig is increasingly being used as a model for humans in biomedical studies, because of its many similarities with the human physiology and anatomy. The aim of this study was to examine whether, as in humans, a shift is seen in the hepatic expression of a CYP3A7- like enzyme to cytochrome P450 3A29 (CYP3A29 (an orthologue to the human CYP3A4 in minipigs. This was elucidated by examining the hepatic mRNA expression of CYP3A7 and CYP3A29 in 39 foetuses and newborn Göttingen minipigs using quantitative real time polymerase chain reaction (qPCR. Furthermore the immunochemical level of CYP3A7-LE and CYP3A29 was measured in liver microsomes using western blotting. The expression of CYP3A29 was approximately 9- fold greater in neonates compared to foetuses, and a similar difference was reflected on the immunochemical level. It was not possible to detect a significant level of foetal CYP3A7 mRNA, but immunoblotting showed a visible difference depending on age. This study demonstrates an increase in the expression of CYP3A29, the CYP3A4 orthologue in perinatal minipigs as in humans, which suggests that the minipig could be a good model when testing for human foetal toxicity towards CYP3A4 substrates.

  6. Porcine alanine transaminase after liver allo-and xenotransplantation

    OpenAIRE

    Ekser, Burcin; Gridelli, Bruno; Cooper, David K.C.

    2012-01-01

    Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was t...

  7. Porcine alanine transaminase after liver allo-and xenotransplantation.

    Science.gov (United States)

    Ekser, Burcin; Gridelli, Bruno; Cooper, David K C

    2012-01-01

    Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was the source of the graft. We hypothesized that the cience of Galα1,3Gal in GTKO pig livers may render pig hepatocytes similar to human and baboon hepatocytes in their response to hepatocellular injury. Reviewing the literature, after WT pig liver allotransplantation or xenotransplantation, in the majority of reports, although changes in AST were reported, no mention was made of changes in ALT, suggesting that there was no change in ALT. However, Ramirez et al. reported two cases of liver xenotransplants from hCD55 pigs, following which there were increases in both AST and ALT, suggesting that it is not simply the cience of expression of Galα1,3Gal that is the cause. We acknowledge that our observation is based on a small number of experiments, but we believe it is worth recording. © 2012 John Wiley & Sons A/S.

  8. Porcine foetal and neonatal CYP3A liver expression

    DEFF Research Database (Denmark)

    Hermann-Bank, Marie Louise; Skaanild, Mette Tingleff

    2011-01-01

    enzyme in the foetal liver, whereas the expression of CYP3A4 is low. After parturition there is a shift in the expression, thus CYP3A7 is down regulated, while the level of CYP3A4 gradually increases and becomes the dominant metabolising CYP3A enzyme in the adult. The minipig is increasingly being used......3A4) in minipigs. This was elucidated by examining the hepatic mRNA expression of CYP3A7 and CYP3A29 in 39 foetuses and newborn Göttingen minipigs using quantitative real time polymerase chain reaction (qPCR). Furthermore the immunochemical level of CYP3A7-LE and CYP3A29 was measured in liver...

  9. In vivo measurement of nitric oxide production in porcine gut, liver and muscle during hyperdynamic endotoxaemia

    NARCIS (Netherlands)

    Bruins, Maaike J.; Lamers, Wouter H.; Meijer, Alfred J.; Soeters, Peter B.; Deutz, Nicolaas E. P.

    2002-01-01

    1. During prolonged endotoxaemia, an increase in arginine catabolism may result in limiting substrate availability for nitric oxide (NO) production. These effects were quantitated in a chronically instrumented porcine endotoxaemia model. 2. Ten days prior to the beginning of the experiments, pigs

  10. VIP receptors from porcine liver: High yield solubilization in a GTP-insensitive form

    International Nuclear Information System (INIS)

    Voisin, T.; Couvineau, A.; Guijarro, L.; Laburthe, M.

    1990-01-01

    Vasoactive intestinal peptide (VIP) receptors were solubilized from porcine liver membranes using CHAPS. The binding of 125 I-VIP to solubilized receptors was reversible, saturable and specific. Scatchard analysis indicated the presence of one binding site with a Kd of 6.5 ± 0.3 nM and a Bmax of 1.20 ± 0.15 pmol/mg protein. Solubilized and membrane-bound receptors displayed the same pharmacological profile since VIP and VIP-related peptides inhibited 125 I-VIP binding to both receptor preparations with the same rank order of potency e.g. VIP>helodermin>rat GRF>rat PHI>secretin>human GRF. GTP inhibited 125 I-VIP binding to membrane-bound receptors but not to solubilized receptors supporting functional uncoupling of VIP receptor and G protein during solubilization. Affinity labeling of solubilized and membrane-bound VIP receptors with 125 I-VIP revealed the presence of a single molecular component with Mr 55,000 in both cases. It is concluded that VIP receptors from porcine liver can be solubilized with a good yield, in a GTP-insensitive, G protein-free form. This represents a major advance towards the purification of VIP receptors

  11. A porcine model of haematogenous brain infectionwith staphylococcus aureus

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg

    2012-01-01

    A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark boye@life.ku.dk 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...... thromboemboli (two pigs). The venous catheter was used for blood sampling before, during and after inoculation. The pigs were euthanized either 24 or 48 hours after inoculation. The brains were collected and examined histologically. Results We describe unifocal suppurative encephalitis 48 hours after...

  12. Tissue ablation accelerated by peripheral scanning mode with high-intensity focused ultrasound: a study on isolated porcine liver perfusion.

    Science.gov (United States)

    Bu, Rui; Yin, Li; Yang, Han; Wang, Qi; Wu, Feng; Zou, Jian Zhong

    2013-08-01

    The aims of this study were to investigate the feasibility of accelerated tissue ablation using a peripheral scanning mode with high-intensity focused ultrasound (HIFU) and to explore the effect of flow rate on total energy consumption of the target tissues. Using a model of isolated porcine liver perfusion via the portal vein and hepatic artery, we conducted a scanning protocol along the periphery of the target tissues using linear-scanned HIFU to carefully adjust the varying focal depth, generator power, scanning velocity and line-by-line interval over the entire ablation range. Porcine livers were divided into four ablation groups: group 1, n = 12, with dual-vessel perfusion; group 2, n = 11, with portal vein perfusion alone; group 3, n = 10, with hepatic artery perfusion alone; and group 4, n = 11, control group with no-flow perfusion. The samples were cut open consecutively at a thickness of 3 mm, and the actual ablation ranges were calculated along the periphery of the target tissues after triphenyl tetrazolium chloride staining. Total energy consumption was calculated as the sum of the energy requirements at various focal depths in each group. On the basis of the pre-supposed scanning protocol, the peripheral region of the target tissue formed a complete coagulation necrosis barrier in each group with varying dose combinations, and the volume of the peripheral necrotic area did not differ significantly among the four groups (p > 0.05). Furthermore, total energy consumption in each group significantly decreased with the corresponding decrease in flow rate (p Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  13. Time dependence of electrical bioimpedance on porcine liver and kidney under a 50 Hz ac current

    International Nuclear Information System (INIS)

    Spottorno, J; Rivero, G; Venta, J de la; Multigner, M; Alvarez, L; Santos, M

    2008-01-01

    The purpose of this work is to study the changes of the bioimpedance from its 'in vivo' value to the values measured in a few hours after the excision from the body. The evolution of electrical impedance with time after surgical extraction has been studied on two porcine organs: the liver and the kidney. Both in vivo and ex vivo measurements of electrical impedance, measuring its real and imaginary components, have been performed. The in vivo measurements have been carried out with the animal anaesthetized. The ex vivo measurements have been made more than 2 h after the extraction of the organ. The latter experiment has been carried out at two different stabilized temperatures: at normal body temperature and at the standard preservation temperature for transplant surgery. The measurements show a correlation between the biological evolution and the electrical bioimpedance of the organs, which increases from its in vivo value immediately after excision, multiplying its value by 2 in a few hours

  14. Normothermic extracorporeal perfusion of isolated porcine liver after warm ischaemia: a preliminary report.

    Science.gov (United States)

    Bellomo, Rinaldo; Suzuki, Satoshi; Marino, Bruno; Starkey, Graeme K; Chambers, Brenton; Fink, Michael A; Wang, Bao Zhong; Houston, Shane; Eastwood, Glenn; Calzavacca, Paolo; Glassford, Neil; Skene, Alison; Jones, Daryl A; Jones, Robert

    2012-09-01

    Liver transplantation is a major life-saving procedure, and donation after cardiac death (DCD) has increased the pool of potential liver donors. However, DCD livers are at increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to protect, evaluate and, in future, transplant DCD livers. We conducted proof-of-concept experiments using a DCD model in the pig to assess the short-term (4 hours) feasibility and functional efficacy of NELP. Using extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion, and physiological perfusion pressures, we achieved NELP and evidence of function (bile production, paracetamol removal, maintenance of normal ammonia and lactate levels) for 4 hours in pig livers subjected to 15 and 30 minutes of cardiac arrest before explantation. Our experiments justify further investigations of the feasibility and efficacy of human DCD liver preservation by ex-vivo perfusion.

  15. Pancreas specific expression of oncogenes in a porcine model

    DEFF Research Database (Denmark)

    Berthelsen, Martin Fogtmann; Callesen, Morten Møbjerg; Østergaard, Tanja Stenshøj

    2017-01-01

    crucial for successful treatment. However, pancreatic cancer is difficult to detect in its earliest stages and once symptoms appear, the cancer has often progressed beyond possibility for curing. Research into the disease has been hampered by the lack of good models. We have generated a porcine m...

  16. Transplantation of Porcine Hepatocytes Cultured with Polylactic Acid-O-Carboxymethylated Chitosan Nanoparticles Promotes Liver Regeneration in Acute Liver Failure Rats

    Directory of Open Access Journals (Sweden)

    Zhong Chen

    2011-01-01

    Full Text Available In this study, free porcine hepatocytes suspension (Group A, porcine hepatocytes embedded in collagen gel (Group B, porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel (Group C, and PLA-O-CMC nanoparticles alone (Group D were transplanted into peritoneal cavity of ALF rats, respectively. The result showed that plasma HGF levels were elevated post-transplantation with a peak at 12 hr. The rats in Group C showed highest plasma HGF levels at 2, 6, 12, 24 and 36 hr post-transplantation and lowest HGF level at 48 hr. Plasma VEGF levels were elevated at 48 hr post-transplantation with a peak at 72 hr. The rats in Group C showed highest plasma HGF levels at 48, 72, and 96 hr post-transplantation. The liver functions in Group C were recovered most rapidly. Compared with Group B, Group C had significant high liver Kiel 67 antigen labeling index (Ki-67 LI at day 1 post-HTx (P<.05. Ki-67 LI in groups B and C was higher than that in groups A and D at days 5 and 7 post-HTx. In conclusion, intraperitoneal transplantation of porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel can promote significantly liver regeneration in ALF rats.

  17. Computational Modeling in Liver Surgery

    Directory of Open Access Journals (Sweden)

    Bruno Christ

    2017-11-01

    Full Text Available The need for extended liver resection is increasing due to the growing incidence of liver tumors in aging societies. Individualized surgical planning is the key for identifying the optimal resection strategy and to minimize the risk of postoperative liver failure and tumor recurrence. Current computational tools provide virtual planning of liver resection by taking into account the spatial relationship between the tumor and the hepatic vascular trees, as well as the size of the future liver remnant. However, size and function of the liver are not necessarily equivalent. Hence, determining the future liver volume might misestimate the future liver function, especially in cases of hepatic comorbidities such as hepatic steatosis. A systems medicine approach could be applied, including biological, medical, and surgical aspects, by integrating all available anatomical and functional information of the individual patient. Such an approach holds promise for better prediction of postoperative liver function and hence improved risk assessment. This review provides an overview of mathematical models related to the liver and its function and explores their potential relevance for computational liver surgery. We first summarize key facts of hepatic anatomy, physiology, and pathology relevant for hepatic surgery, followed by a description of the computational tools currently used in liver surgical planning. Then we present selected state-of-the-art computational liver models potentially useful to support liver surgery. Finally, we discuss the main challenges that will need to be addressed when developing advanced computational planning tools in the context of liver surgery.

  18. Ultrasound imaging of Nd:YAG laser-induced tissue coagulation in porcine livers.

    Science.gov (United States)

    Ritzel, U; Wietzke-Braun, P; Brinck, U; Leonhardt, U; Ramadori, G

    2001-12-01

    Absorption of laser light energy induces denaturation of proteins and thermocoagulation of irradiated tissue. Recently, MRI-guided laser coagulation in combination with MR thermometry was reported as a treatment of liver tumours. In the present study ultrasonographic imaging was evaluated for its suitability in laser induced tissue thermocoagulation. Fresh porcine livers were used for ex vivo examinations. Placement of the laser catheter and tissue coagulation during laser light emission were online monitored by ultrasonography. Nd:YAG laser-induced tissue damage was evaluated by macroscopical and microscopical examinations of histological sections. During laser light emission a marked hyperdense signal enhancement was observed by ultrasonography which strongly correlated with the extent of macroscopic tissue damage. The size of laser-induced coagulation zone depended on both the power setting and total energy delivered. Carbonization of the tissue surrounding the laser tip is a limiting factor because of laser light absorption. However our data indicate that using appropriate laser energy and exposure time prevent carbonization although carbonization can not be visualized by ultrasonography. It is concluded from the present ex vivo studies that laser coagulation can be effectively performed under ultrasonographic guidance.

  19. Cardiac Dysfunction in a Porcine Model of Pediatric Malnutrition

    DEFF Research Database (Denmark)

    Fabiansen, Christian; Lykke, Mikkel; Hother, Anne-Louise

    2015-01-01

    BACKGROUND: Half a million children die annually of severe acute malnutrition and cardiac dysfunction may contribute to the mortality. However, cardiac function remains poorly examined in cases of severe acute malnutrition. OBJECTIVE: To determine malnutrition-induced echocardiographic disturbances...... and longitudinal changes in plasma pro-atrial natriuretic peptide and cardiac troponin-T in a pediatric porcine model. METHODS AND RESULTS: Five-week old piglets (Duroc-x-Danish Landrace-x-Yorkshire) were fed a nutritionally inadequate maize-flour diet to induce malnutrition (MAIZE, n = 12) or a reference diet...... groups. The myocardial performance index was 86% higher in MAIZE vs AGE-REF (pMalnutrition associates with cardiac dysfunction in a pediatric porcine model by increased myocardial performance index and pro-atrial natriuretic peptide...

  20. Machine Perfusion of Porcine Livers with Oxygen-Carrying Solution Results in Reprogramming of Dynamic Inflammation Networks

    Directory of Open Access Journals (Sweden)

    David Sadowsky

    2016-11-01

    Full Text Available Background: Ex vivo machine perfusion (MP can better preserve organs for transplantation. We have recently reported on the first application of a MP protocol in which liver allografts were fully oxygenated, under dual pressures and subnormothermic conditions, with a new hemoglobin-based oxygen carrier solution specifically developed for ex vivo utilization. In those studies, MP improved organ function post-operatively and reduced inflammation in porcine livers. Herein, we sought to refine our knowledge regarding the impact of MP by defining dynamic networks of inflammation in both tissue and perfusate. Methods: Porcine liver allografts were preserved either with MP (n = 6 or with cold static preservation (CSP; n = 6, then transplanted orthotopically after 9 h of preservation. Fourteen inflammatory mediators were measured in both tissue and perfusate during liver preservation at multiple time points, and analyzed using Dynamic Bayesian Network (DyBN inference to define feedback interactions, as well as Dynamic Network Analysis (DyNA to define the time-dependent development of inflammation networks.Results: Network analyses of tissue and perfusate suggested an NLRP3 inflammasome-regulated response in both treatment groups, driven by the pro-inflammatory cytokine interleukin (IL-18 and the anti-inflammatory mediator IL-1 receptor antagonist (IL-1RA. Both DyBN and DyNA suggested a reduced role of IL-18 and increased role of IL-1RA with MP, along with increased liver damage with CSP. DyNA also suggested divergent progression of responses over the 9 h preservation time, with CSP leading to a stable pattern of IL-18-induced liver damage and MP leading to a resolution of the pro-inflammatory response. These results were consistent with prior clinical, biochemical, and histological findings after liver transplantation. Conclusion: Our results suggest that analysis of dynamic inflammation networks in the setting of liver preservation may identify novel

  1. Time dependence of electrical bioimpedance on porcine liver and kidney under a 50 Hz ac current

    Energy Technology Data Exchange (ETDEWEB)

    Spottorno, J; Rivero, G; Venta, J de la [Instituto de Magnetismo Aplicado (ADIF-UCM-CSIC), PO Box 155, Las Rozas, Madrid 28230 (Spain); Multigner, M [Departamento de Fisica de Materiales, UCM, Ciudad Universitaria, 28040 Madrid (Spain); Alvarez, L; Santos, M [Centro de Investigacion Biomedica en Red en BioingenierIa, Biomateriales y Nanomedicina (CIBER-BBN), Madrid (Spain)

    2008-03-21

    The purpose of this work is to study the changes of the bioimpedance from its 'in vivo' value to the values measured in a few hours after the excision from the body. The evolution of electrical impedance with time after surgical extraction has been studied on two porcine organs: the liver and the kidney. Both in vivo and ex vivo measurements of electrical impedance, measuring its real and imaginary components, have been performed. The in vivo measurements have been carried out with the animal anaesthetized. The ex vivo measurements have been made more than 2 h after the extraction of the organ. The latter experiment has been carried out at two different stabilized temperatures: at normal body temperature and at the standard preservation temperature for transplant surgery. The measurements show a correlation between the biological evolution and the electrical bioimpedance of the organs, which increases from its in vivo value immediately after excision, multiplying its value by 2 in a few hours.

  2. Radiofrequency thermal ablation of benign cystic lesion: an experimental pilot study in a porcine gallbladder model

    International Nuclear Information System (INIS)

    Song, Ho Taek; Rhim, Hyun Chul; Choi, Jung Bin; Oh, Jae Cheon; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Seo, Heung Suk; Joo, Kyung Bin

    2001-01-01

    To determine whether radiofrequency thermal ablation can be used to treat benign cystic lesions in a porcine gallbladder model. This experimental study of radiofrequency thermal ablation involved the use of 15 exvivo porcine gallbladders and 15-G expandable needle electrodes. To investigate optimal temperature parameters, three groups of five were designated according to target temperature:Group A: 70 deg C; Group B: 80 deg C; Group C: 90 deg C. After the target temperature was reached, ablation lasted for one minute. Gallbladder width, height and length were measured before and after ablation , and the estimated volume reduction ratios of the three groups were compared. Whether adjacent liver parenchyma around the gallbladder fossa was ablated by heat conducted from hot bile was also determined, and the thickness of the ablated area of the liver was measured. The volume reduction ratio in Group A, B and C was 42.7%, 41.7% and 42.9%, respectively (ρ>.05). In all 15 cases, gallbladder walls lost their transparency and elasticity at about 70 deg C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 deg C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A livers, only one case showed minimal gradual parenchymal change. Microscopically, all three groups showed complete coagulation necrosis of the wall. On the basis of this feasibility study, radiofrequency thermal ablation is potentially suitable for the ultrasound-guided treatment of symptomatic cystic lesions including benign hepatic or renal cyst

  3. Mechanism of porcine liver xanthine oxidoreductase mediated N-oxide reduction of cyadox as revealed by docking and mutagenesis studies.

    Directory of Open Access Journals (Sweden)

    Chigang Chen

    Full Text Available Xanthine oxidoreductase (XOR is a cytoplasmic molybdenum-containing oxidoreductase, catalyzing both endogenous purines and exogenous compounds. It is suggested that XOR in porcine hepatocytes catalyzes the N-oxide reduction of quinoxaline 1,4-di-N-oxides (QdNOs. To elucidate the molecular mechanism underlying this metabolism, the cDNA of porcine XOR was cloned and heterologously expressed in Spodoptera frugiperda insect cells. The bovine XOR, showing sequence identity of 91% to porcine XOR, was employed as template for homology modeling. By docking cyadox, a representative compound of QdNOs, into porcine XOR model, eight amino acid residues, Gly47, Asn352, Ser360, Arg427, Asp430, Asp431, Ser1227 and Lys1230, were located at distances of less than 4Å to cyadox. Site-directed mutagenesis was performed to analyze their catalytic functions. Compared with wild type porcine XOR, G47A, S360P, D431A, S1227A, and K1230A displayed altered kinetic parameters in cyadox reduction, similarly to that in xanthine oxidation, indicating these mutations influenced electron-donating process of xanthine before subsequent electron transfer to cyadox to fulfill the N-oxide reduction. Differently, R427E and D430H, both located in the 424-434 loop, exhibited a much lower K(m and a decreased V(max respectively in cyadox reduction. Arg427 may be related to the substrate binding of porcine XOR to cyadox, and Asp430 is suggested to be involved in the transfer of electron to cyadox. This study initially reveals the possible catalytic mechanism of porcine XOR in cyadox metabolism, providing with novel insights into the structure-function relationship of XOR in the reduction of exogenous di-N-oxides.

  4. Porcine models of biofilm infections with focus on pathomorphology

    DEFF Research Database (Denmark)

    Jensen, Louise Kruse; Johansen, Anne Sofie Boyum; Jensen, Henrik Elvang

    2017-01-01

    , and reproducible animal models of the infections. In this review, the advantages of in vivo studies are compared to in vitro studies of biofilm formation in infectious diseases. The pig is the animal of choice when developing and applying large animal models of infectious diseases due to its similarity of anatomy......, physiology, and immune system to humans. Furthermore, conventional pigs spontaneously develop many of the same chronic bacterial infections as seen in humans. Therefore, in this review porcine models of five different infectious diseases all associated with biofilm formation and chronicity in humans...

  5. [An experimental model of transgastric ooforectomy using a porcine model].

    Science.gov (United States)

    Tomulescu, V; Gheorghe, C; Piţigoi, D; Kosa, A; Ciocarlan, M; Pietrăreanu, D; Turcu, F; Copăescu, C; Droc, G; Popescu, H; Grigorescu, B; Stănciulea, O; Herlea, V; Popescu, I

    2010-01-01

    Transabdominal routes for surgery entail general anaesthesia with its inherent risks and complications (prolonged hospital stay, abdominal incisions that may be difficult in obese patients). Minimally invasive procedures require shorter hospitalization, have shorter recovery periods, less postoperative discomfort, and lower morbidity and complications. The purpose of this study was to use a porcine model to determine the feasibility and the safety of organ resection (oophorectomy and tubectomy). 10 Big White pigs between 25-30 kg underwent transgastric ooforectomy. The first 5 cases were performed in a hybrid procedure (laparoscopic-NOTES) in order to have a better control and supervise the maneuvers done by the mobile endoscope and to guide in the abdominal cavity. Adnexectomy was possible in all ten experiments. Full operative time (from starting endoscopy to complete gastrectomy closing) was 180 min to 270 min. The gastric defect closing was the most difficult manoever lasting from 10 min with OTSC clips to 100 using endoloops and clips. The animals have tolerated well the experiments and there have been no remarkable incidents during our 10 experments. In only one case a bleeding from gastotomy required electric coagulation. Transgastric ooforectomy in an experimental model is a procedure that requires advanced laparoscopical and endoscopical skills. Our early results are promissing. Its application in humans needs further confirmation of the method.

  6. In vivo porcine training model for cranial neurosurgery.

    Science.gov (United States)

    Regelsberger, Jan; Eicker, Sven; Siasios, Ioannis; Hänggi, Daniel; Kirsch, Matthias; Horn, Peter; Winkler, Peter; Signoretti, Stefano; Fountas, Kostas; Dufour, Henry; Barcia, Juan A; Sakowitz, Oliver; Westermaier, Thomas; Sabel, Michael; Heese, Oliver

    2015-01-01

    Supplemental education is desirable for neurosurgical training, and the use of human cadaver specimen and virtual reality models is routine. An in vivo porcine training model for cranial neurosurgery was introduced in 2005, and our recent experience with this unique model is outlined here. For the first time, porcine anatomy is illustrated with particular respect to neurosurgical procedures. The pros and cons of this model are described. The aim of the course was to set up a laboratory scenery imitating an almost realistic operating room in which anatomy of the brain and neurosurgical techniques in a mentored environment free from time constraints could be trained. Learning objectives of the course were to learn about the microsurgical techniques in cranial neurosurgery and the management of complications. Participants were asked to evaluate the quality and utility of the programme via standardized questionnaires by a grading scale from A (best) to E (worst). In total, 154 residents have been trained on the porcine model to date. None of the participants regarded his own residency programme as structured. The bleeding and complication management (97%), the realistic laboratory set-up (89%) and the working environment (94%) were favoured by the vast majority of trainees and confirmed our previous findings. After finishing the course, the participants graded that their skills in bone drilling, dissecting the brain and preserving cerebral vessels under microscopic magnification had improved to level A and B. In vivo hands-on courses, fully equipped with microsurgical instruments, offer an outstanding training opportunity in which bleeding management on a pulsating, vital brain represents a unique training approach. Our results have shown that education programmes still lack practical training facilities in which in vivo models may act as a complementary approach in surgical training.

  7. Development of a Consistent and Reproducible Porcine Scald Burn Model

    Science.gov (United States)

    Kempf, Margit; Kimble, Roy; Cuttle, Leila

    2016-01-01

    There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. PMID:27612153

  8. Experimental models of liver fibrosis.

    Science.gov (United States)

    Yanguas, Sara Crespo; Cogliati, Bruno; Willebrords, Joost; Maes, Michaël; Colle, Isabelle; van den Bossche, Bert; de Oliveira, Claudia Pinto Marques Souza; Andraus, Wellington; Alves, Venâncio Avancini Ferreira; Leclercq, Isabelle; Vinken, Mathieu

    2016-05-01

    Hepatic fibrosis is a wound healing response to insults and as such affects the entire world population. In industrialized countries, the main causes of liver fibrosis include alcohol abuse, chronic hepatitis virus infection and non-alcoholic steatohepatitis. A central event in liver fibrosis is the activation of hepatic stellate cells, which is triggered by a plethora of signaling pathways. Liver fibrosis can progress into more severe stages, known as cirrhosis, when liver acini are substituted by nodules, and further to hepatocellular carcinoma. Considerable efforts are currently devoted to liver fibrosis research, not only with the goal of further elucidating the molecular mechanisms that drive this disease, but equally in view of establishing effective diagnostic and therapeutic strategies. The present paper provides a state-of-the-art overview of in vivo and in vitro models used in the field of experimental liver fibrosis research.

  9. Characterization of a porcine model of chronic superficial varicose veins.

    Science.gov (United States)

    Jones, Gregory T; Grant, Mark W; Thomson, Ian A; Hill, B Geraldine; van Rij, André M

    2009-06-01

    Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins. Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins. Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening. The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.

  10. Prevention of primary vascular graft infection with silver-coated polyester graft in a porcine model

    DEFF Research Database (Denmark)

    Gao, H; Sandermann, J; Prag, J

    2010-01-01

    To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model.......To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model....

  11. Creating Porcine Biomedical Models Through Recombineering

    Directory of Open Access Journals (Sweden)

    Lawrence B. Schook

    2006-03-01

    Full Text Available Recent advances in genomics provide genetic information from humans and other mammals (mouse, rat, dog and primates traditionally used as models as well as new candidates (pigs and cattle. In addition, linked enabling technologies, such as transgenesis and animal cloning, provide innovative ways to design and perform experiments to dissect complex biological systems. Exploitation of genomic information overcomes the traditional need to choose naturally occurring models. Thus, investigators can utilize emerging genomic knowledge and tools to create relevant animal models. This approach is referred to as reverse genetics. In contrast to ‘forward genetics’, in which gene(s responsible for a particular phenotype are identified by positional cloning (phenotype to genotype, the ‘reverse genetics’ approach determines the function of a gene and predicts the phenotype of a cell, tissue, or organism (genotype to phenotype. The convergence of classical and reverse genetics, along with genomics, provides a working definition of a ‘genetic model’ organism (3. The recent construction of phenotypic maps defining quantitative trait loci (QTL in various domesticated species provides insights into how allelic variations contribute to phenotypic diversity. Targeted chromosomal regions are characterized by the construction of bacterial artificial chromosome (BAC contigs to isolate and characterize genes contributing towards phenotypic variation. Recombineering provides a powerful methodology to harvest genetic information responsible for phenotype. Linking recombineering with gene-targeted homologous recombination, coupled with nuclear transfer (NT technology can provide ‘clones’ of genetically modified animals.

  12. Functional Characterization of a Porcine Emphysema Model

    DEFF Research Database (Denmark)

    Bruun, Camilla Sichlau; Jensen, Louise Kruse; Leifsson, Páll Skuli

    2013-01-01

    Lung emphysema is a central feature of chronic obstructive pulmonary disease (COPD), a frequent human disease worldwide. Cigarette smoking is the major cause of COPD, but genetic predisposition seems to be an important factor. Mutations in surfactant protein genes have been linked to COPD...... phenotypes in humans. Also, the catalytic activities of metalloproteinases (MMPs) are central in the pathogenesis of emphysema/COPD. Especially MMP9, but also MMP2, MMP7, and MMP12 seem to be involved in human emphysema. MMP12−/− mice are protected from smoke-induced emphysema. ITGB6−/− mice spontaneously...... develop age-related lung emphysema due to lack of ITGB6-TGF-β1 regulation of the MMP12 expression.A mutated pig phenotype characterized by age-related lung emphysema and resembling the ITGB6−/− mouse has been described previously. To investigate the emphysema pathogenesis in this pig model, we examined...

  13. Towards the establishment of a porcine model to study human amebiasis.

    Directory of Open Access Journals (Sweden)

    Fabienne Girard-Misguich

    Full Text Available BACKGROUND: Entamoeba histolytica is an important parasite of the human intestine. Its life cycle is monoxenous with two stages: (i the trophozoite, growing in the intestine and (ii the cyst corresponding to the dissemination stage. The trophozoite in the intestine can live as a commensal leading to asymptomatic infection or as a tissue invasive form producing mucosal ulcers and liver abscesses. There is no animal model mimicking the whole disease cycle. Most of the biological information on E. histolytica has been obtained from trophozoite adapted to axenic culture. The reproduction of intestinal amebiasis in an animal model is difficult while for liver amebiasis there are well-described rodent models. During this study, we worked on the assessment of pigs as a new potential model to study amebiasis. METHODOLOGY/PRINCIPAL FINDINGS: We first co-cultured trophozoites of E. histolytica with porcine colonic fragments and observed a disruption of the mucosal architecture. Then, we showed that outbred pigs can be used to reproduce some lesions associated with human amebiasis. A detailed analysis was performed using a washed closed-jejunal loops model. In loops inoculated with virulent amebas a severe acute ulcerative jejunitis was observed with large hemorrhagic lesions 14 days post-inoculation associated with the presence of the trophozoites in the depth of the mucosa in two out four animals. Furthermore, typical large sized hepatic abscesses were observed in the liver of one animal 7 days post-injection in the portal vein and the liver parenchyma. CONCLUSIONS: The pig model could help with simultaneously studying intestinal and extraintestinal lesion development.

  14. The safety and availability of xenotransplantated encapsulized newborn porcine islets into the diabetic dog's liver via hepatic artery

    International Nuclear Information System (INIS)

    Ye Bin; Wang Wei; Liu Sheng

    2006-01-01

    Objective: To evaluate the biocompatibility, immunology and physiologic features of encapsulated Newborn Porcine Islets (NPI) in the liver of the recipient dogs with type I diabetes. Methods: Type I diabetic dogs were perfused with 400000-600000 encapsulated NPI (group A, n=15) or unencapsulated NPI (group B, n=15) through the hepatic artery without immunosuppressive treatment. Liver function and CD4/CD8 in the recipients were measured before and after the transplantation. The livers from all NPI recipient dogs were analyzed by histopathology 6 months after transplantation(Tx). Results: Insulin dose administrated to group A was reduced gradually within one week after Tx, from 22 u before Tx to 5 u after Tx, exogenous insulin required for group B was decreased from 24 u to 10 u. However, 2 to 3 weeks after Tx, the insulin dose given to group B returned to the original level before Tx. In contrast, the amount of insulin administrated to group A was continually reduced to 8 u. Moreover, CD4 + cells in the blood of group B recipients were higher than that before Tx, whereas no significant alteration of CD4+ cells and CD8+ cells in the blood of group A after Tx. All NPI recipient dogs demonstrated a normal function and structure of the liver after Tx. Conclusion: Microcapsulated NPI has a good biocompatibility in recipients livers providing prolongation of xenograft survival, and correcting the hyperglycemia of diabetic canines. (authors)

  15. Anatomy and bronchoscopy of the porcine lung. A model for translational respiratory medicine.

    LENUS (Irish Health Repository)

    Judge, Eoin P

    2014-09-01

    The porcine model has contributed significantly to biomedical research over many decades. The similar size and anatomy of pig and human organs make this model particularly beneficial for translational research in areas such as medical device development, therapeutics and xenotransplantation. In recent years, a major limitation with the porcine model was overcome with the successful generation of gene-targeted pigs and the publication of the pig genome. As a result, the role of this model is likely to become even more important. For the respiratory medicine field, the similarities between pig and human lungs give the porcine model particular potential for advancing translational medicine. An increasing number of lung conditions are being studied and modeled in the pig. Genetically modified porcine models of cystic fibrosis have been generated that, unlike mouse models, develop lung disease similar to human cystic fibrosis. However, the scientific literature relating specifically to porcine lung anatomy and airway histology is limited and is largely restricted to veterinary literature and textbooks. Furthermore, methods for in vivo lung procedures in the pig are rarely described. The aims of this review are to collate the disparate literature on porcine lung anatomy, histology, and microbiology; to provide a comparison with the human lung; and to describe appropriate bronchoscopy procedures for the pig lungs to aid clinical researchers working in the area of translational respiratory medicine using the porcine model.

  16. 915 MHz microwave ablation with implanted internal cooled-shaft antenna: Initial experimental study in in vivo porcine livers

    International Nuclear Information System (INIS)

    Cheng Zhigang; Xiao Qiujin; Wang Yang; Sun Yuanyuan; Lu Tong; Liang Ping

    2011-01-01

    Purpose: To explore a preferred power output for further clinical application based on the ablated lesions induced by the four power outputs of 915 MHz microwave in experimental study of in vivo porcine livers. Materials and methods: A KY2000-915 microwave ablation system with an implanted 915 MHz internal cooled-shaft antenna was used in this study. A total of 24 ablations were performed in eight in vivo porcine livers. The energy was applied for 10 min at microwave output powers of 50 W, 60 W, 70 W, and 80 W. Long-axis and short-axis diameters of the coagulation zone were measured on all gross specimens. Results: The shapes of the 915 MHz microwave ablation lesions were elliptical commonly. As the power increased, the long-axis and short-axis diameters of the coagulation zone had a tendency to rise. But the long-axis diameter of the ablated lesion at 50 W was not significantly smaller than that of the ablated lesion at 60 W (P > 0.05) and there were no statistical differences in short-axis diameters of the ablated lesion among the three power outputs of 60 W, 70 W and 80 W (P > 0.05). After 10 min irradiation of 60 W, the long-axis and short-axis diameters of the coagulation zone were 5.02 ± 0.60 cm and 3.65 ± 0.46 cm, respectively. Conclusions: For decreasing the undesired damages of liver tissues along the shaft and the number of antenna in further clinically percutaneous microwave ablation treatment, the power of 60 W may be a preferred setting among the four power outputs used in present study.

  17. Emerging technologies to create inducible and genetically defined porcine cancer models

    Directory of Open Access Journals (Sweden)

    Lawrence B Schook

    2016-02-01

    Full Text Available There is an emerging need for new animal models that address unmet translational cancer research requirements. Transgenic porcine models provide an exceptional opportunity due to their genetic, anatomic and physiological similarities with humans. Due to recent advances in the sequencing of domestic animal genomes and the development of new organism cloning technologies, it is now very feasible to utilize pigs as a malleable species, with similar anatomic and physiological features with humans, in which to develop cancer models. In this review, we discuss genetic modification technologies successfully used to produce porcine biomedical models, in particular the Cre-loxP System as well as major advances and perspectives the CRISPR/Cas9 System. Recent advancements in porcine tumor modeling and genome editing will bring porcine models to the forefront of translational cancer research.

  18. Emerging Technologies to Create Inducible and Genetically Defined Porcine Cancer Models.

    Science.gov (United States)

    Schook, Lawrence B; Rund, Laurie; Begnini, Karine R; Remião, Mariana H; Seixas, Fabiana K; Collares, Tiago

    2016-01-01

    There is an emerging need for new animal models that address unmet translational cancer research requirements. Transgenic porcine models provide an exceptional opportunity due to their genetic, anatomic, and physiological similarities with humans. Due to recent advances in the sequencing of domestic animal genomes and the development of new organism cloning technologies, it is now very feasible to utilize pigs as a malleable species, with similar anatomic and physiological features with humans, in which to develop cancer models. In this review, we discuss genetic modification technologies successfully used to produce porcine biomedical models, in particular the Cre-loxP System as well as major advances and perspectives the CRISPR/Cas9 System. Recent advancements in porcine tumor modeling and genome editing will bring porcine models to the forefront of translational cancer research.

  19. Liver Cancer Risk Prediction Models

    Science.gov (United States)

    Developing statistical models that estimate the probability of developing liver cancer over a defined period of time will help clinicians identify individuals at higher risk of specific cancers, allowing for earlier or more frequent screening and counseling of behavioral changes to decrease risk.

  20. Pathology and biofilm formation in a porcine model of staphylococcal osteomyelitis

    DEFF Research Database (Denmark)

    Johansen, L K; Koch, J; Frees, D

    2012-01-01

    A porcine model was used to examine the potential of human and porcine Staphylococcus aureus isolates to induce haematogenously spread osteomyelitis. Pigs were inoculated in the right femoral artery with one of the following S. aureus strains: S54F9 (from a porcine lung abscess; n = 3 animals), N...... dependent on the strain of bacteria inoculated and on the formation of a biofilm....... with colonies of S. aureus as demonstrated immunohistochemically. By peptide nucleic acid fluorescence in situ hybridization bacterial aggregates were demonstrated to be embedded in an opaque matrix, indicating that the bacteria had formed a biofilm. Development of experimental osteomyelitis was therefore...

  1. A porcine astrocyte/endothelial cell co-culture model of the blood-brain barrier.

    Science.gov (United States)

    Jeliazkova-Mecheva, Valentina V; Bobilya, Dennis J

    2003-10-01

    A method for the isolation of porcine atrocytes as a simple extension of a previously described procedure for isolation of brain capillary endothelial cells from adolescent pigs [Methods Cell Sci. 17 (1995) 2] is described. The obtained astroglial culture purified through two passages and by the method of the selective detachment was validated by a phase contrast microscopy and through an immunofluorescent assay for the glial fibrillary acidic protein (GFAP). Porcine astrocytes were co-cultivated with porcine brain capillary endothelial cells (PBCEC) for the development of an in vitro blood-brain barrier (BBB) model. The model was visualized by an electron microscopy and showed elevated transendothellial electrical resistance and reduced inulin permeability. To our knowledge, this is the first report for the establishment of a porcine astrocyte/endothelial cell co-culture BBB model, which avoids interspecies and age differences between the two cell types, usually encountered in the other reported co-culture BBB models. Considering the availability of the porcine brain tissue and the close physiological and anatomical relation between the human and pig brain, the porcine astrocyte/endothelial cell co-culture system can serve as a reliable and easily reproducible model for different in vitro BBB studies.

  2. Estudo ultrassonográfico morfométrico do fígado e trato biliar de suínos submetidos a obstrução biliar experimental Sonographic morphometry of the liver and biliary tract in porcine models submitted to experimental biliary obstruction

    Directory of Open Access Journals (Sweden)

    Aline Gomes de Campos

    2013-04-01

    Full Text Available OBJETIVO: Comparar as alterações anatômicas decorrentes de um quadro de icterícia obstrutiva experimental induzida em suínos nos períodos pré e pós-operatório por meio de exame ultrassonográfico. MATERIAIS E MÉTODOS: Seis suínos da raça Landrace, com 36 dias de idade, foram submetidos a obstrução biliar completa mediante ligadura do ducto colédoco por cirurgia videolaparoscópica. RESULTADOS: Não ocorreram dificuldades na execução dos procedimentos obstrutivos e a recuperação cirúrgica foi eficiente. Decorridos sete dias, os animais apresentaram icterícia, bilirrubinúria e acolia fecal. O exame ultrassonográfico comparativo permitiu visualizar hepatomegalia, colecistomegalia e aumento no calibre do ducto colédoco em todos os animais, assim como alterações decorrentes da colestase. A avaliação morfométrica revelou aumento significativo nos diâmetros da vesícula biliar e do lobo hepático lateral esquerdo. CONCLUSÃO: Os suínos representam um modelo experimental adequado de icterícia obstrutiva, e o exame ultrassonográfico demonstrou-se sensível e relevante no diagnóstico das alterações decorrentes de obstrução biliar extra-hepática nesses animais.OBJECTIVE: To compare, by means of ultrasonography, pre- and postoperative anatomical changes arising from experimentally induced obstructive jaundice in porcine models. MATERIALS AND METHODS: Six 36-day-old Landrace pigs underwent laparoscopically induced complete biliary obstruction by common bile duct ligation. RESULTS: No difficulty was faced during the procedures and the surgical recovery was uneventful. After seven days, the animals showed jaundice, bilirubinuria and acholic stools. Comparative ultrasonography allowed visualization of hepatomegaly, cholecystomegaly and increased caliber of the common bile duct in all the animals, as well as changes resulting from cholestasis. The morphometric analysis revealed a significant increase in diameter of the

  3. The effect of intra-abdominal hypertension incorporating severe acute pancreatitis in a porcine model.

    Directory of Open Access Journals (Sweden)

    Lu Ke

    Full Text Available INTRODUCTION: Abdominal compartment syndrome (ACS and intra abdominal hypertension(IAH are common clinical findings in patients with severe acute pancreatitis(SAP. It is thought that an increased intra abdominal pressure(IAP is associated with poor prognosis in SAP patients. But the detailed effect of IAH/ACS on different organ system is not clear. The aim of this study was to assess the effect of SAP combined with IAH on hemodynamics, systemic oxygenation, and organ damage in a 12 h lasting porcine model. MEASUREMENTS AND METHODS: Following baseline registrations, a total of 30 animals were divided into 5 groups (6 animals in each group: SAP+IAP30 group, SAP+IAP20 group, SAP group, IAP30 group(sham-operated but without SAP and sham-operated group. We used a N(2 pneumoperitoneum to induce different levels of IAH and retrograde intra-ductal infusion of sodium taurocholate to induce SAP. The investigation period was 12 h. Hemodynamic parameters (CO, HR, MAP, CVP, urine output, oxygenation parameters(e.g., S(vO(2, PO(2, PaCO(2, peak inspiratory pressure, as well as serum parameters (e.g., ALT, amylase, lactate, creatinine were recorded. Histological examination of liver, intestine, pancreas, and lung was performed. MAIN RESULTS: Cardiac output significantly decreased in the SAP+IAH animals compared with other groups. Furthermore, AST, creatinine, SUN and lactate showed similar increasing tendency paralleled with profoundly decrease in S(vO(2. The histopathological analyses also revealed higher grade injury of liver, intestine, pancreas and lung in the SAP+IAH groups. However, few differences were found between the two SAP+IAH groups with different levels of IAP. CONCLUSIONS: Our newly developed porcine SAP+IAH model demonstrated that there were remarkable effects on global hemodynamics, oxygenation and organ function in response to sustained IAH of 12 h combined with SAP. Moreover, our model should be helpful to study the mechanisms of IAH

  4. Internal vacuum-assisted closure device in the swine model of severe liver injury

    Directory of Open Access Journals (Sweden)

    Everett Christopher B

    2012-12-01

    Full Text Available Abstract Objectives The authors present a novel approach to nonresectional therapy in major hepatic trauma utilizing intraabdominal perihepatic vacuum assisted closure (VAC therapy in the porcine model of Grade V liver injury. Methods A Grade V injury was created in the right lobe of the liver in a healthy pig. A Pringle maneuver was applied (4.5 minutes total clamp time and a vacuum assisted closure device was placed over the injured lobe and connected to suction. The device consisted of a perforated plastic bag placed over the liver, followed by a 15 cm by 15cm VAC sponge covered with a nonperforated plastic bag. The abdomen was closed temporarily. Blood loss, cardiopulmonary parameters and bladder pressures were measured over a one-hour period. The device was then removed and the animal was euthanized. Results Feasibility of device placement was demonstrated by maintenance of adequate vacuum suction pressures and seal. VAC placement presented no major technical challenges. Successful control of ongoing liver hemorrhage was achieved with the VAC. Total blood loss was 625 ml (20ml/kg. This corresponds to class II hemorrhagic shock in humans and compares favorably to previously reported estimated blood losses with similar grade liver injuries in the swine model. No post-injury cardiopulmonary compromise or elevated abdominal compartment pressures were encountered, while hepatic parenchymal perfusion was maintained. Conclusion These data demonstrate the feasibility and utility of a perihepatic negative pressure device for the treatment of hemorrhage from severe liver injury in the porcine model.

  5. Surgical induction of choroidal neovascularization in a porcine model

    DEFF Research Database (Denmark)

    Lassota, Nathan; Kiilgaard, Jens Folke; Prause, Jan Ulrik

    2007-01-01

    PURPOSE: To develop a reproducible surgical technique for the induction of choroidal neovascularization (CNV) in the subretinal space of porcine eyes and to analyse the resulting CNV clinically and histologically. METHODS: Two different modifications of a surgical technique previously described...... were compared with the original method. In ten porcine eyes retinal pigment epithelial (RPE) cells were removed using a silicone tipped cannula, in ten porcine eyes Bruch's membrane was perforated once with a retinal perforator without prior RPE removal and in ten eyes RPE removal was followed...... by a single perforation of Bruch's membrane. Fifteen of the eyes, five from each group, were enucleated 30 minutes after surgery, while the remaining eyes were enucleated after 14 days. Prior to enucleation, at day 14, fundus photographs and fluorescein angiograms were obtained. Eyes were examined by light...

  6. Development of porcine model of chronic tachycardia-induced cardiomyopathy.

    Science.gov (United States)

    Paslawska, Urszula; Gajek, Jacek; Kiczak, Liliana; Noszczyk-Nowak, Agnieszka; Skrzypczak, Piotr; Bania, Jacek; Tomaszek, Alicja; Zacharski, Maciej; Sambor, Izabela; Dziegiel, Piotr; Zysko, Dorota; Banasiak, Waldemar; Jankowska, Ewa A; Ponikowski, Piotr

    2011-11-17

    There are few experimental models of heart failure (HF) in large animals, despite structural and functional similarities to human myocardium. We have developed a porcine model of chronic tachycardia-induced cardiomyopathy. Homogenous siblings of White Large breed swine (n=6) underwent continuous right ventricular (RV) pacing at 170 bpm; 2 subjects served as controls. In the course of RV pacing, animals developed a clinical picture of HF and were presented for euthanasia at subsequent stages: mild, moderate and end-stage HF. Left ventricle (LV) sections were analyzed histologically and relative ANP, BNP, phospholamban and sarcoplasmic reticulum calcium ATPase 2a transcript levels in LV were quantified by real time RT-PCR. In the course of RV pacing, animals demonstrated reduced exercise capacity (time of running until being dyspnoeic: 6.6 ± 0.5 vs. 2.4 ± 1.4 min), LV dilatation (LVEDD: 4.9 ± 0.4 vs. 6.7 ± 0.4 cm), impaired LV systolic function (LVEF: 69 ± 8 vs. 32 ± 7 %), (all baseline vs. before euthanasia, all p<0.001). LV tissues from animals with moderate and end-stage HF demonstrated local foci of interstitial fibrosis, congestion, cardiomyocyte hypertrophy and atrophy, which was not detected in controls and mild HF animals. The up-regulation of ANP and BNP and a reduction in a ratio of sarcoplasmic reticulum calcium ATPase 2a and phospholamban in failing myocardium were observed as compared to controls. In pigs, chronic RV pacing at relatively low rate can be used as an experimental model of HF, as it results in a gradual deterioration of exercise tolerance accompanied by myocardial remodeling confirmed at subcellular level. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Comparison of temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna: Results in ex vivo porcine livers

    International Nuclear Information System (INIS)

    Sun Yuanyuan; Cheng Zhigang; Dong Lei; Zhang Guoming; Wang Yang; Liang Ping

    2012-01-01

    Objective: To compare temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna in ex vivo porcine livers. Materials and methods: The 915- and 2450-MHz microwave ablation and thermal monitor system were used in this study. A total of 56 ablation zones and 280 temperature data were obtained in ex vivo porcine livers. The output powers were 50, 60, 70, and 80 W and the setting time was 600 s. The temperature curve of every temperature spot, the short- and long-axis diameters of the coagulation zones were recorded and measured. Results: At all four power output settings, the peak temperatures of every temperature spot had a tendency to increase accordingly as the MW output power was increased, and except for 5 mm away from the antenna, the peak temperatures for the 915 MHz cooled-shaft antenna were significantly higher than those for the 2450 MHz cooled-shaft antenna (p < 0.05). Meanwhile, the short- and long-axis diameters for the 915 MHz cooled-shaft antenna were significantly larger than those for the 2450 MHz cooled-shaft antenna (p < 0.05). Conclusion: The 915 MHz cooled-shaft antenna can yield a significantly larger ablation zone and achieve higher temperature in ablation zone than a 2450 MHz cooled-shaft antenna in ex vivo porcine livers.

  8. Possibilities of microscopic detection of isolated porcine proteins in model meat products

    Directory of Open Access Journals (Sweden)

    Michaela Petrášová

    2016-05-01

    Full Text Available In recent years, various protein additives intended for manufacture of meat products have increasing importance in the food industry. These ingredients include both, plant-origin as well as animal-origin proteins. Among animal proteins, blood plasma, milk protein or collagen are used most commonly. Collagen is obtained from pork, beef, and poultry or fish skin. Collagen does not contain all the essential amino acids, thus it is not a full protein in terms of essential amino acids supply for one's organism. However, it is rather rich in amino acids of glycine, hydroxyproline and proline which are almost absent in other proteins and their synthesis is very energy intensive. Collagen, which is added to the soft and small meat products in the form of isolated porcine protein, significantly affects the organoleptic properties of these products. This work focused on detection of isolated porcine protein in model meat products where detection of isolated porcine protein was verified by histological staining and light microscopy. Seven model meat products from poultry meat and 7 model meat products from beef and pork in the ratio of 1:1, which contained 2.5% concentration of various commercially produced isolated porcine proteins, were examined. These model meat products were histologically processed by means of cryosections and stained with hematoxylin-eosin staining, toluidine blue staining and Calleja. For the validation phase, Calleja was utilized. To determine the sensitivity and specificity, five model meat products containing the addition of isolated porcine protein and five model meat products free of it were used. The sensitivity was determined for isolated porcine protein at 1.00 and specificity was determined at 1.00. The detection limit of the method was at the level of 0.001% addition. Repeatability of the method was carried out using products with addition as well as without addition of isolated porcine protein and detection was repeated

  9. Characterisation of the porcine eyeball as an in-vitro model for dry eye.

    Science.gov (United States)

    Menduni, Francesco; Davies, Leon N; Madrid-Costa, D; Fratini, Antonio; Wolffsohn, James S

    2018-02-01

    To characterise the anatomical parameters of the porcine eye for potentially using it as a laboratory model of dry eye. Anterior chamber depth and angle, corneal curvature, shortest and longest diameter, endothelial cell density, and pachymetry were measured in sixty freshly enucleated porcine eyeballs. Corneal steepest meridian was 7.85±0.32mm, corneal flattest meridian was 8.28±0.32mm, shortest corneal diameter was 12.69±0.58mm, longest corneal diameter was 14.88±0.66mm and central corneal ultrasonic pachymetry was 1009±1μm. Anterior chamber angle was 28.83±4.16°, anterior chamber depth was 1.77±0.27mm, and central corneal thickness measured using OCT was 1248±144μm. Corneal endothelial cell density was 3250±172 cells/mm 2 . Combining different clinical techniques produced a pool of reproducible data on the porcine eye anatomy, which can be used by researchers to assess the viability of using the porcine eye as an in-vitro/ex-vivo model for dry eye. Due to the similar morphology with the human eye, porcine eyeballs may represent a useful and cost effective model to individually study important key factors in the development of dry eye, such as environmental and mechanical stresses. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  10. Improved stability and catalytic activity of graphene oxide/chitosan hybrid beads loaded with porcine liver esterase.

    Science.gov (United States)

    Sunderrajan, Shruthi; Miranda, Lima Rose; Pennathur, Gautam

    2018-04-21

    Graphene oxide/chitosan and reduced graphene oxide/chitosan (GO/CS and RGO/CS) beads were prepared by precipitation with NaOH. Porcine liver esterase was immobilized on these beads to give GO/CS/E and RGO/CS/E beads. The optimum conditions for the maximum activity of RGO/CS/E beads were pH 8 and 50°C. The stability of the enzyme immobilized on GO/CS/E and RGO/CS/E was high in the pH range of 5-8. The GO/CS/E beads showed superior stability compared to that of the free enzyme and CS/E beads between 20 and 50°C. Kinetic analysis showed that GO/CS/E was a better catalyst than the RGO/CS/E beads with a lower K m value of 0.9 mM. The hybrid beads also retained more than 95% activity after 10 consecutive cycles. The GO/CS/E and RGO/CS/E beads retained 84% and 87% activity after 40 days at 4°C. The GO/CS/E beads were used for the successful hydrolysis of methyl 4-hydroxy benzoate.

  11. Selective Activation of N,N'-Diacyl Rhodamine Pro-fluorophores Paired with Releasing Enzyme, Porcine Liver Esterase (PLE).

    Science.gov (United States)

    Abney, Kristopher K; Ramos-Hunter, Susan J; Romaine, Ian M; Godwin, J Shawn; Sulikowski, Gary A; Weaver, Charles David

    2018-04-21

    This study reports the synthesis and testing of a family of rhodamine pro-fluorophores and an enzyme capable of converting pro-fluorophores to Rhodamine 110. We prepared a library of simple N,N'-diacyl rhodamines and investigated Porcine Liver Esterase (PLE) as an enzyme to activate rhodamine-based pro-fluorophores. A PLE-expressing cell line generated an increase in fluorescence rapidly upon pro-fluorophore addition demonstrating the rhodamine pro-fluorophores are readily taken up and fluorescent upon PLE-mediated release. Rhodamine pro-fluorophore amides trifluoroacetamide (TFAm) and proponamide (PAm) appeared to be the best substrates using a cell-based assay using PLE expressing HEK293. Our pro-fluorophore series showed diffusion into live cells and resisted endogenous hydrolysis. The use of our engineered cell line containing the exogenous enzyme PLE demonstrated the rigorousness of amide masking when compared to cells not containing PLE. This simple and selective pro-fluorophore rhodamine pair with PLE offers the potential to be used in vitro and in vivo fluorescence based assays. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Hypothermic Oxygenated Machine Perfusion in Porcine Donation After Circulatory Determination of Death Liver Transplant

    NARCIS (Netherlands)

    Fondevila, Constantino; Hessheimer, Amelia J.; Maathuis, Mark-Hugo J.; Munoz, Javier; Taura, Pilar; Calatayud, David; Leuvenink, Henri; Rimola, Antoni; Garcia-Valdecasas, Juan C.; Ploeg, Rutger J.

    2012-01-01

    Background. Livers from donation after circulatory determination-of-death (DCD) donors suffer ischemic injury during a preextraction period of cardiac arrest and are infrequently used for transplantation; they have the potential, however, to considerably expand the donor pool. We aimed to determine

  13. CT radiation dose and image quality optimization using a porcine model.

    Science.gov (United States)

    Zarb, Francis; McEntee, Mark F; Rainford, Louise

    2013-01-01

    To evaluate potential radiation dose savings and resultant image quality effects with regard to optimization of commonly performed computed tomography (CT) studies derived from imaging a porcine (pig) model. Imaging protocols for 4 clinical CT suites were developed based on the lowest milliamperage and kilovoltage, the highest pitch that could be set from current imaging protocol parameters, or both. This occurred before significant changes in noise, contrast, and spatial resolution were measured objectively on images produced from a quality assurance CT phantom. The current and derived phantom protocols were then applied to scan a porcine model for head, abdomen, and chest CT studies. Further optimized protocols were developed based on the same methodology as in the phantom study. The optimization achieved with respect to radiation dose and image quality was evaluated following data collection of radiation dose recordings and image quality review. Relative visual grading analysis of image quality criteria adapted from the European guidelines on radiology quality criteria for CT were used for studies completed with both the phantom-based or porcine-derived imaging protocols. In 5 out of 16 experimental combinations, the current clinical protocol was maintained. In 2 instances, the phantom protocol reduced radiation dose by 19% to 38%. In the remaining 9 instances, the optimization based on the porcine model further reduced radiation dose by 17% to 38%. The porcine model closely reflects anatomical structures in humans, allowing the grading of anatomical criteria as part of image quality review without radiation risks to human subjects. This study demonstrates that using a porcine model to evaluate CT optimization resulted in more radiation dose reduction than when imaging protocols were tested solely on quality assurance phantoms.

  14. Immunohistochemical and radiological characterization of wound healing in porcine liver after radiofrequency ablation.

    Science.gov (United States)

    Stadlbauer, Vanessa; Lang-Olip, Ingrid; Leber, Bettina; Mayrhauser, Ursula; Koestenbauer, Sonja; Tawdrous, Monika; Moche, Michael; Sereinigg, Michael; Seider, Daniel; Iberer, Florian; Wiederstein-Grasser, Iris; Portugaller, Rupert Horst; Stiegler, Philipp

    2016-01-01

    Radiofrequency ablation (RFA) is a minimal invasive therapeutic option for patients with hepatocellular carcinoma or liver metastases. We investigated RFA-induced cellular changes in the liver of pigs. Healthy pigs (n=18) were sacrificed between day 0 and 3 months after RFA. The wound healing process was evaluated by computed tomography (CT), chromotrope anilinblue (CAB) staining of large-scale and standard tissue sections. Immunohistochemistry (IHC) for heat shock protein 70, Caspase-3, Ki67, Reelin, Vinculin, Vimentin and α-SMA was perfomed. One day after RFA, CAB staining showed cell damage and massive hyperaemia. All IHC markers were predominantly expressed at the outer borders of the lesion, except Reelin, which was mainly detected in untreated liver regions. By staining for Hsp70, the heat stress during RFA was monitored, which was most distinct 1-2 days after RFA. CT revealed decreased lesion size after one week. Development of a Vimentin and α-SMA positive fibrotic capsule was observed. In the early phase signs of cell damage, apoptosis and proliferation are dominant. Reduced expression of Reelin suggests a minor role of hepatic stellate cells in the RFA zone. After one week myofibroblasts become prominent and contribute to the development of the fibrotic capsule. This elucidates the pathophysiology of RFA and could contribute to the future optimization of RFA procedures.

  15. Improved cell line IPEC-J2, characterized as a model for porcine jejunal epithelium.

    Directory of Open Access Journals (Sweden)

    Silke S Zakrzewski

    Full Text Available Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS or species-specific (porcine serum, PS conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS, compared to conventional FBS culture (IPEC-J2/FBS, the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line's initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function.

  16. Comparing the reported burn conditions for different severity burns in porcine models: a systematic review.

    Science.gov (United States)

    Andrews, Christine J; Cuttle, Leila

    2017-12-01

    There are many porcine burn models that create burns using different materials (e.g. metal, water) and different burn conditions (e.g. temperature and duration of exposure). This review aims to determine whether a pooled analysis of these studies can provide insight into the burn materials and conditions required to create burns of a specific severity. A systematic review of 42 porcine burn studies describing the depth of burn injury with histological evaluation is presented. Inclusion criteria included thermal burns, burns created with a novel method or material, histological evaluation within 7 days post-burn and method for depth of injury assessment specified. Conditions causing deep dermal scald burns compared to contact burns of equivalent severity were disparate, with lower temperatures and shorter durations reported for scald burns (83°C for 14 seconds) compared to contact burns (111°C for 23 seconds). A valuable archive of the different mechanisms and materials used for porcine burn models is presented to aid design and optimisation of future models. Significantly, this review demonstrates the effect of the mechanism of injury on burn severity and that caution is recommended when burn conditions established by porcine contact burn models are used by regulators to guide scald burn prevention strategies. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  17. Evaluation of hands-on seminar for reduced port surgery using fresh porcine cadaver model

    Directory of Open Access Journals (Sweden)

    Saseem Poudel

    2016-01-01

    Full Text Available Background: The use of various biological and non-biological simulators is playing an important role in training modern surgeons with laparoscopic skills. However, there have been few reports of the use of a fresh porcine cadaver model for training in laparoscopic surgical skills. The purpose of this study was to report on a surgical training seminar on reduced port surgery using a fresh cadaver porcine model and to assess its feasibility and efficacy. Materials and Methods: The hands-on seminar had 10 fresh porcine cadaver models and two dry boxes. Each table was provided with a unique access port and devices used in reduced port surgery. Each group of 2 surgeons spent 30 min at each station, performing different tasks assisted by the instructor. The questionnaire survey was done immediately after the seminar and 8 months after the seminar. Results: All the tasks were completed as planned. Both instructors and participants were highly satisfied with the seminar. There was a concern about the time allocated for the seminar. In the post-seminar survey, the participants felt that the number of reduced port surgeries performed by them had increased. Conclusion: The fresh cadaver porcine model requires no special animal facility and can be used for training in laparoscopic procedures.

  18. Evaluation of hands-on seminar for reduced port surgery using fresh porcine cadaver model.

    Science.gov (United States)

    Poudel, Saseem; Kurashima, Yo; Shichinohe, Toshiaki; Kitashiro, Shuji; Kanehira, Eiji; Hirano, Satoshi

    2016-01-01

    The use of various biological and non-biological simulators is playing an important role in training modern surgeons with laparoscopic skills. However, there have been few reports of the use of a fresh porcine cadaver model for training in laparoscopic surgical skills. The purpose of this study was to report on a surgical training seminar on reduced port surgery using a fresh cadaver porcine model and to assess its feasibility and efficacy. The hands-on seminar had 10 fresh porcine cadaver models and two dry boxes. Each table was provided with a unique access port and devices used in reduced port surgery. Each group of 2 surgeons spent 30 min at each station, performing different tasks assisted by the instructor. The questionnaire survey was done immediately after the seminar and 8 months after the seminar. All the tasks were completed as planned. Both instructors and participants were highly satisfied with the seminar. There was a concern about the time allocated for the seminar. In the post-seminar survey, the participants felt that the number of reduced port surgeries performed by them had increased. The fresh cadaver porcine model requires no special animal facility and can be used for training in laparoscopic procedures.

  19. The effect of dietary fatty acids on post-operative inflammatory response in a porcine model

    DEFF Research Database (Denmark)

    Langerhuus, Sine Nygaard; Jensen, Karin Hjelholt; Tønnesen, Else Kirstine

    2012-01-01

    ), sunflower oil (SO, n 28), or animal fat (AF, n 28) was evaluated with respect to post-operative responses in inflammatory markers in a porcine model on aortic vascular prosthetic graft infection. In the early post-operative period (0 necrosis factor...

  20. Corneal epithelial cell viability of an ex vivo porcine eye model.

    Science.gov (United States)

    Chan, Ka Yin; Cho, Pauline; Boost, Maureen

    2014-07-01

    The aim was to assess the consistency of corneal epithelial cell viability of an ex vivo porcine eye model. Six porcine eye models (four test and two control) were prepared for each experiment. The model has a computer-controlled mechanical arm, which could move the eyelid of the porcine eye and apply phosphate buffered saline to simulate blinking and lacrimation. The four test eyes were set up to simulate evaporative dry eyes with simulated lacrimation and blinking (one blink and one drop of buffered saline per minute) over three hours. Control A models were set up to collect pre-experimental baseline data, while those of control B were the same as the test eyes but without lacrimation and blinking simulation. All porcine eyes were kept in a closed chamber with temperature and humidity well controlled. After three hours, the cells of all eyes (except control A, which were assessed immediately before commencement of the experiment) were assessed. The eyes were first dipped into 0.4 per cent trypan blue solution. Following the dissection and separation of the cells, the number of dead cells were then counted under the microscope with a field size of 0.25 mm(2). The experiment was repeated 11 times. No significant differences were found in the number of dead cells among the four test eyes in both the central and peripheral cornea. There were significantly more dead cells in the test eyes compared to control A but significantly less when compared to control B. More dead cells were found in the central cornea than the peripheral cornea in the test eyes but the difference was not observed in controls A and B. Epithelial cell viabilities among the four porcine eye models with simulated lacrimation and blinking were consistent. The majority of cells were viable before the experiment and simulated lacrimation and blinking maintained more viable cells over time. © 2014 The Authors. Clinical and Experimental Optometry © 2014 Optometrists Association Australia.

  1. Optimal conditions for cordycepin production in surface liquid-cultured Cordyceps militaris treated with porcine liver extracts for suppression of oral cancer.

    Science.gov (United States)

    Lin, Liang-Tzung; Lai, Ying-Jang; Wu, She-Ching; Hsu, Wei-Hsuan; Tai, Chen-Jei

    2018-01-01

    Cordycepin is one of the most crucial bioactive compounds produced by Cordyceps militaris and has exhibited antitumor activity in various cancers. However, industrial production of large amounts of cordycepin is difficult. The porcine liver is abundant in proteins, vitamins, and adenosine, and these ingredients may increase cordycepin production and bioconversion during C. militaris fermentation. We observed that porcine liver extracts increased cordycepin production. In addition, air supply (2 h/d) significantly increased the cordycepin level in surface liquid-cultured C. militaris after 14 days. Moreover, blue light light-emitting diode irradiation (16 h/d) increased cordycepin production. These findings indicated that these conditions are suitable for increasing cordycepin production. We used these conditions to obtain water extract from the mycelia of surface liquid-cultured C. militaris (WECM) and evaluated the anti-oral cancer activity of this extract in vitro and in vivo. The results revealed that WECM inhibited the cell viability of SCC-4 oral cancer cells and arrested the cell cycle in the G2/M phase. Oxidative stress and mitochondrial dysfunction (mitochondrial fission) were observed in SCC-4 cells treated with WECM for 12 hours. Furthermore, WECM reduced tumor formation in 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis through the downregulation of proliferating cell nuclear antigen, vascular endothelial growth factor, and c-fos expression. The results indicated that porcine liver extracts irradiated with blue light light-emitting diode and supplied with air can be used as a suitable medium for the growth of mycelia and production of cordycepin, which can be used in the treatment of oral cancer. Copyright © 2017. Published by Elsevier B.V.

  2. Model Predictions and Measured Skin Damage Thresholds for 1.54 Micrometers Laser Pulses in Porcine Skin

    National Research Council Canada - National Science Library

    Roach, William P; Cain, Clarence; Schuster, Kurt; Stockton, Kevin; Stolarski, David S; Galloway, Robert; Rockwell, Benjamin

    2004-01-01

    A new source-term thermal model was used to determine the skin temperature rise using porcine skin parameters for various wavelengths, pulse durations, and laser spot sizes and is compared to the Takata thermal model...

  3. An ultrasound needle insertion guide in a porcine phantom model.

    Science.gov (United States)

    Whittaker, S; Lethbridge, G; Kim, C; Keon Cohen, Z; Ng, I

    2013-08-01

    We compared nerve blockade with and without the Infiniti(TM) needle guide in an ultrasound in-plane porcine simulation. We recruited 30 anaesthetists with varying blockade experience. Using the guide, the needle tip was more visible (for a median (IQR [range]) of 67 (56-100]) % of the time; and invisible for 2 (1-4 [0-19]) s) than when the guide was not used (respectively 23 (13-43 [0-80]) % and 25 (9-52 [1-198]) s; both p < 0.001). The corresponding block times were 8 (6-10 [3-28]) s and 32 (15-67 [5-225]) s, respectively; p < 0.001. The needle guide reduced the block time and the time that the needle was invisible, irrespective of anaesthetist experience. Anaesthesia © 2013 The Association of Anaesthetists of Great Britain and Ireland.

  4. Transcriptome Analysis of Porcine PBMCs Reveals the Immune Cascade Response and Gene Ontology Terms Related to Cell Death and Fibrosis in the Progression of Liver Failure

    Directory of Open Access Journals (Sweden)

    YiMin Zhang

    2018-01-01

    Full Text Available Background. The key gene sets involved in the progression of acute liver failure (ALF, which has a high mortality rate, remain unclear. This study aims to gain a deeper understanding of the transcriptional response of peripheral blood mononuclear cells (PBMCs following ALF. Methods. ALF was induced by D-galactosamine (D-gal in a porcine model. PBMCs were separated at time zero (baseline group, 36 h (failure group, and 60 h (dying group after D-gal injection. Transcriptional profiling was performed using RNA sequencing and analysed using DAVID bioinformatics resources. Results. Compared with the baseline group, 816 and 1,845 differentially expressed genes (DEGs were identified in the failure and dying groups, respectively. A total of five and two gene ontology (GO term clusters were enriched in 107 GO terms in the failure group and 154 GO terms in the dying group. These GO clusters were primarily immune-related, including genes regulating the inflammasome complex and toll-like receptor signalling pathways. Specifically, GO terms related to cell death, including apoptosis, pyroptosis, and autophagy, and those related to fibrosis, coagulation dysfunction, and hepatic encephalopathy were enriched. Seven Kyoto Encyclopedia of Genes and Genomes (KEGG pathways, cytokine-cytokine receptor interaction, hematopoietic cell lineage, lysosome, rheumatoid arthritis, malaria, and phagosome and pertussis pathways were mapped for DEGs in the failure group. All of these seven KEGG pathways were involved in the 19 KEGG pathways mapped in the dying group. Conclusion. We found that the dramatic PBMC transcriptome changes triggered by ALF progression was predominantly related to immune responses. The enriched GO terms related to cell death, fibrosis, and so on, as indicated by PBMC transcriptome analysis, seem to be useful in elucidating potential key gene sets in the progression of ALF. A better understanding of these gene sets might be of preventive or

  5. Bimodal electric tissue ablation (BETA) - in-vivo evaluation of the effect of applying direct current before and during radiofrequency ablation of porcine liver

    International Nuclear Information System (INIS)

    Cockburn, J.F.; Maddern, G.J.; Wemyss-Holden, S.A.

    2007-01-01

    Aim: To examine the effect of applying increasing amounts of direct current (DC) before and during alternating current radiofrequency ablation of porcine liver. Materials and methods: Using a Radiotherapeutics RF3000 generator, a 9 V AC/DC transformer and a 16 G plain aluminium tube as an electrode, a control group of 24 porcine hepatic radiofrequency ablation zones was compared with 24 zones created using a bimodal electric tissue ablation (BETA) technique in three pigs. All ablations were terminated when tissue impedance rose to greater than 999 Ω or radiofrequency energy input fell below 5 W on three successive measurements taken at 1 min intervals. BETA ablations were performed in two phases: an initial phase of variable duration DC followed by a second phase during which standard radiofrequency ablation was applied simultaneously with DC. During this second phase, radiofrequency power input was regulated by the feedback circuitry of the RF3000 generator according to changes in tissue impedance. The diameters (mm) of each ablation zone were measured by two observers in two planes perpendicular to the plane of needle insertion. The mean short axis diameter of each ablation zone was subjected to statistical analysis. Results: With increased duration of prior application of DC, there was a progressive increase in the diameter of the ablation zone (p < 0.001). This effect increased sharply up to 300 s of pre-treatment after which a further increase in diameter occurred, but at a much lesser rate. A maximum ablation zone diameter of 32 mm was produced (control diameters 10-13 mm). Conclusion: Applying a 9 V DC to porcine liver in vivo, and continuing this DC application during subsequent radiofrequency ablation, results in larger ablation zone diameters compared with radiofrequency ablation alone

  6. Sampling Strategies and Processing of Biobank Tissue Samples from Porcine Biomedical Models.

    Science.gov (United States)

    Blutke, Andreas; Wanke, Rüdiger

    2018-03-06

    In translational medical research, porcine models have steadily become more popular. Considering the high value of individual animals, particularly of genetically modified pig models, and the often-limited number of available animals of these models, establishment of (biobank) collections of adequately processed tissue samples suited for a broad spectrum of subsequent analyses methods, including analyses not specified at the time point of sampling, represent meaningful approaches to take full advantage of the translational value of the model. With respect to the peculiarities of porcine anatomy, comprehensive guidelines have recently been established for standardized generation of representative, high-quality samples from different porcine organs and tissues. These guidelines are essential prerequisites for the reproducibility of results and their comparability between different studies and investigators. The recording of basic data, such as organ weights and volumes, the determination of the sampling locations and of the numbers of tissue samples to be generated, as well as their orientation, size, processing and trimming directions, are relevant factors determining the generalizability and usability of the specimen for molecular, qualitative, and quantitative morphological analyses. Here, an illustrative, practical, step-by-step demonstration of the most important techniques for generation of representative, multi-purpose biobank specimen from porcine tissues is presented. The methods described here include determination of organ/tissue volumes and densities, the application of a volume-weighted systematic random sampling procedure for parenchymal organs by point-counting, determination of the extent of tissue shrinkage related to histological embedding of samples, and generation of randomly oriented samples for quantitative stereological analyses, such as isotropic uniform random (IUR) sections generated by the "Orientator" and "Isector" methods, and vertical

  7. Open wedge high tibial osteotomy using three-dimensional printed models: Experimental analysis using porcine bone.

    Science.gov (United States)

    Kwun, Jun-Dae; Kim, Hee-June; Park, Jaeyoung; Park, Il-Hyung; Kyung, Hee-Soo

    2017-01-01

    The purpose of this study was to evaluate the usefulness of three-dimensional (3D) printed models for open wedge high tibial osteotomy (HTO) in porcine bone. Computed tomography (CT) images were obtained from 10 porcine knees and 3D imaging was planned using the 3D-Slicer program. The osteotomy line was drawn from the three centimeters below the medial tibial plateau to the proximal end of the fibular head. Then the osteotomy gap was opened until the mechanical axis line was 62.5% from the medial border along the width of the tibial plateau, maintaining the posterior tibial slope angle. The wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The open wedge HTO surgery was reproduced in porcine bone using the 3D-printed model and the osteotomy site was fixed with a plate. Accuracy of osteotomy and posterior tibial slope was evaluated after the osteotomy. The mean mechanical axis line on the tibial plateau was 61.8±1.5% from the medial tibia. There was no statistically significant difference (P=0.160). The planned and post-osteotomy correction wedge angles were 11.5±3.2° and 11.4±3.3°, and the posterior tibial slope angle was 11.2±2.2° pre-osteotomy and 11.4±2.5° post-osteotomy. There were no significant differences (P=0.854 and P=0.429, respectively). This study showed that good results could be obtained in high tibial osteotomy by using 3D printed models of porcine legs. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Anatomical manifestations of primary blast ocular trauma observed in a postmortem porcine model.

    Science.gov (United States)

    Sherwood, Daniel; Sponsel, William E; Lund, Brian J; Gray, Walt; Watson, Richard; Groth, Sylvia L; Thoe, Kimberly; Glickman, Randolph D; Reilly, Matthew A

    2014-02-24

    We qualitatively describe the anatomic features of primary blast ocular injury observed using a postmortem porcine eye model. Porcine eyes were exposed to various levels of blast energy to determine the optimal conditions for future testing. We studied 53 enucleated porcine eyes: 13 controls and 40 exposed to a range of primary blast energy levels. Eyes were preassessed with B-scan and ultrasound biomicroscopy (UBM) ultrasonography, photographed, mounted in gelatin within acrylic orbits, and monitored with high-speed videography during blast-tube impulse exposure. Postimpact photography, ultrasonography, and histopathology were performed, and ocular damage was assessed. Evidence for primary blast injury was obtained. While some of the same damage was observed in the control eyes, the incidence and severity of this damage in exposed eyes increased with impulse and peak pressure, suggesting that primary blast exacerbated these injuries. Common findings included angle recession, internal scleral delamination, cyclodialysis, peripheral chorioretinal detachments, and radial peripapillary retinal detachments. No full-thickness openings of the eyewall were observed in any of the eyes tested. Scleral damage demonstrated the strongest associative tendency for increasing likelihood of injury with increased overpressure. These data provide evidence that primary blast alone (in the absence of particle impact) can produce clinically relevant ocular damage in a postmortem model. The blast parameters derived from this study are being used currently in an in vivo model. We also propose a new Cumulative Injury Score indicating the clinical relevance of observed injuries.

  9. Establishment and characterization of a differentiated epithelial cell culture model derived from the porcine cervix uteri

    Directory of Open Access Journals (Sweden)

    Miessen Katrin

    2012-03-01

    Full Text Available Abstract Background Cervical uterine epithelial cells maintain a physiological and pathogen-free milieu in the female mammalian reproductive tract and are involved in sperm-epithelium interaction. Easily accessible, differentiated model systems of the cervical epithelium are not yet available to elucidate the underlying molecular mechanisms within these highly specialized cells. Therefore, the aim of the study was to establish a cell culture of the porcine cervical epithelium representing in vivo-like properties of the tissue. Results We tested different isolation methods and culture conditions and validated purity of the cultured cells by immunohistochemistry against keratins. We could reproducibly culture pure epithelial cells from cervical tissue explants. Based on a morphology score and the WST-1 Proliferation Assay, we optimized the growth medium composition. Primary porcine cervical cells performed best in conditioned Ham's F-12, containing 10% FCS, EGF and insulin. After cultivation in an air-liquid interface for three weeks, the cells showed a discontinuously multilayered phenotype. Finally, differentiation was validated via immunohistochemistry against beta catenin. Mucopolysaccharide production could be shown via alcian blue staining. Conclusions We provide the first suitable protocol to establish a differentiated porcine epithelial model of the cervix uteri, based on easily accessible cells using slaughterhouse material.

  10. Establishment and characterization of a differentiated epithelial cell culture model derived from the porcine cervix uteri.

    Science.gov (United States)

    Miessen, Katrin; Einspanier, Ralf; Schoen, Jennifer

    2012-03-19

    Cervical uterine epithelial cells maintain a physiological and pathogen-free milieu in the female mammalian reproductive tract and are involved in sperm-epithelium interaction. Easily accessible, differentiated model systems of the cervical epithelium are not yet available to elucidate the underlying molecular mechanisms within these highly specialized cells. Therefore, the aim of the study was to establish a cell culture of the porcine cervical epithelium representing in vivo-like properties of the tissue. We tested different isolation methods and culture conditions and validated purity of the cultured cells by immunohistochemistry against keratins. We could reproducibly culture pure epithelial cells from cervical tissue explants. Based on a morphology score and the WST-1 Proliferation Assay, we optimized the growth medium composition. Primary porcine cervical cells performed best in conditioned Ham's F-12, containing 10% FCS, EGF and insulin. After cultivation in an air-liquid interface for three weeks, the cells showed a discontinuously multilayered phenotype. Finally, differentiation was validated via immunohistochemistry against beta catenin. Mucopolysaccharide production could be shown via alcian blue staining. We provide the first suitable protocol to establish a differentiated porcine epithelial model of the cervix uteri, based on easily accessible cells using slaughterhouse material.

  11. Description and evaluation of a bench porcine model for teaching surgical residents vascular anastomosis skills

    Directory of Open Access Journals (Sweden)

    Jauch Karl-Walter

    2010-07-01

    Full Text Available Abstract Background Numerous models, of variable quality, exist to impart the complex skills required to perform vascular anastomosis. These models differ with regard to the kinds of materials used, as well as their sizes, the time needed for their preparation, their availability, and the associated costs. The present study describes a bench model that uses formalin-fixed porcine aorta, and its evaluation by young surgical residents during a recent skills course. Findings The aortic segments used were a by-product of slaughtering. They were fixed and stored after harvesting for eventual use. Ten young surgical residents participated, and each performed one end-to-side vascular anastomosis. The evaluation was a questionnaire maintaining anonymity of the participant containing questions addressing particular aspects of the model and the experiences of the trainee, along with their ratings concerning the need for a training course to learn vascular anastomosis techniques. The scoring on the survey was done using a global 6-point rating scale (Likert Scale. In addition, we ranked the present model by reviewing the current literature for models that address vascular anastomosis skills. The trainees who participated were within their first two years of training (1.25 ± 0.46. A strong agreement in terms of the necessity of training for vascular anastomosis techniques was evident among the participating trainees (5.90 ± 0.32, who had only few prior manual experiences (total number 1.50 ± 0.53. The query revealed a strong agreement that porcine aorta is a suitable model that fits the needs for training vascular anastomosis skills (5.70 ± 0.48. Only a few bench models designed to teach surgical residents vascular anastomosis techniques were available in the literature. Conclusions The preparatory and financial resources needed to perform anastomosis skills training using porcine aorta are few. The presented bench model appears to be appropriate for

  12. Risk Factor Analyses for the Return of Spontaneous Circulation in the Asphyxiation Cardiac Arrest Porcine Model

    Directory of Open Access Journals (Sweden)

    Cai-Jun Wu

    2015-01-01

    Full Text Available Background: Animal models of asphyxiation cardiac arrest (ACA are frequently used in basic research to mirror the clinical course of cardiac arrest (CA. The rates of the return of spontaneous circulation (ROSC in ACA animal models are lower than those from studies that have utilized ventricular fibrillation (VF animal models. The purpose of this study was to characterize the factors associated with the ROSC in the ACA porcine model. Methods: Forty-eight healthy miniature pigs underwent endotracheal tube clamping to induce CA. Once induced, CA was maintained untreated for a period of 8 min. Two minutes following the initiation of cardiopulmonary resuscitation (CPR, defibrillation was attempted until ROSC was achieved or the animal died. To assess the factors associated with ROSC in this CA model, logistic regression analyses were performed to analyze gender, the time of preparation, the amplitude spectrum area (AMSA from the beginning of CPR and the pH at the beginning of CPR. A receiver-operating characteristic (ROC curve was used to evaluate the predictive value of AMSA for ROSC. Results: ROSC was only 52.1% successful in this ACA porcine model. The multivariate logistic regression analyses revealed that ROSC significantly depended on the time of preparation, AMSA at the beginning of CPR and pH at the beginning of CPR. The area under the ROC curve in for AMSA at the beginning of CPR was 0.878 successful in predicting ROSC (95% confidence intervals: 0.773∼0.983, and the optimum cut-off value was 15.62 (specificity 95.7% and sensitivity 80.0%. Conclusions: The time of preparation, AMSA and the pH at the beginning of CPR were associated with ROSC in this ACA porcine model. AMSA also predicted the likelihood of ROSC in this ACA animal model.

  13. A comparison of microwave ablation and bipolar radiofrequency ablation both with an internally cooled probe: Results in ex vivo and in vivo porcine livers

    International Nuclear Information System (INIS)

    Yu Jie; Liang Ping; Yu Xiaoling; Liu Fangyi; Chen Lei; Wang Yang

    2011-01-01

    Purpose: The purpose of this study was to compare the effectiveness of microwave (MW) ablation and radiofrequency (RF) ablation using a single internally cooled probe in a hepatic porcine model. Materials and methods: In the ex vivo experiment, MW ablations (n = 40) were performed with a 2450 MHz and 915 MHz needle antenna, respectively at 60 W, 70 W power settings. Bipolar RF ablations (n = 20) were performed with a 3-cm (T30) and 4-cm (T40) active tip needle electrodes, respectively at a rated power 30 W and 40 W according to automatically systematic power setting. In the in vivo experiment, the 2450 MHz and 915 MHz MW ablation both at 60 W and T30 bipolar RF ablation at 30 W were performed (n = 30). All of the application time were 10 min. Long-axis diameter (Dl), short-axis diameter (Ds), ratio of Ds/Dl, the temperature data 5 mm from the needle and the time of temperature 5 mm from the needle rising to 54 deg. C were measured. Results: Both in ex vivo and in vivo models, Ds and Dl of 915 MHz MW ablations were significantly larger than all the RF ablations (P < 0.05); the Ds for all the 2450 MHz MW ablations were significantly larger than that of T30 RF ablations (P < 0.05). 2450 MHz MW and T30 RF ablation tended to produce more elliptical-shaped ablation zone. Tissue temperatures 5 mm from the needle were considerably higher with MW ablation, meanwhile MW ablation achieved significantly faster rate of temperature rising to 54 deg. C than RF ablation. For in vivo study after 10 min of ablation, the Ds and Dl of 2450 MHz MW, 915 MHz MW and Bipolar RF were 2.35 ± 0.75, 2.95 ± 0.32, 1.61 ± 0.33 and 3.86 ± 0.81, 5.79 ± 1.03, 3.21 ± 0.51, respectively. Highest tissue temperatures 5 mm from the needle were 80.07 ± 12.82 deg. C, 89.07 ± 3.52 deg. C and 65.56 ± 15.31 deg. C and the time of temperature rising to 54 deg. C were respectively 37.50 ± 7.62 s, 24.50 ± 4.09 s and 57.29 ± 23.24 s for three applicators. Conclusion: MW ablation may have higher

  14. Modeling liver electrical conductivity during hypertonic injection.

    Science.gov (United States)

    Castellví, Quim; Sánchez-Velázquez, Patricia; Moll, Xavier; Berjano, Enrique; Andaluz, Anna; Burdío, Fernando; Bijnens, Bart; Ivorra, Antoni

    2018-01-01

    Metastases in the liver frequently grow as scattered tumor nodules that neither can be removed by surgical resection nor focally ablated. Previously, we have proposed a novel technique based on irreversible electroporation that may be able to simultaneously treat all nodules in the liver while sparing healthy tissue. The proposed technique requires increasing the electrical conductivity of healthy liver by injecting a hypersaline solution through the portal vein. Aiming to assess the capability of increasing the global conductivity of the liver by means of hypersaline fluids, here, it is presented a mathematical model that estimates the NaCl distribution within the liver and the resulting conductivity change. The model fuses well-established compartmental pharmacokinetic models of the organ with saline injection models used for resuscitation treatments, and it considers changes in sinusoidal blood viscosity because of the hypertonicity of the solution. Here, it is also described a pilot experimental study in pigs in which different volumes of NaCl 20% (from 100 to 200 mL) were injected through the portal vein at different flow rates (from 53 to 171 mL/minute). The in vivo conductivity results fit those obtained by the model, both quantitatively and qualitatively, being able to predict the maximum conductivity with a 14.6% average relative error. The maximum conductivity value was 0.44 second/m, which corresponds to increasing 4 times the mean basal conductivity (0.11 second/m). The results suggest that the presented model is well suited for predicting on liver conductivity changes during hypertonic saline injection. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Determination of vitamin D3, vitamin D2 and their 25-hydroxy metabolites in porcine liver using high performance liquid chromatography

    International Nuclear Information System (INIS)

    Travis, B.D.; Holmes, R.P.

    1986-01-01

    A method has been developed for the determination of vitamin D 3 , vitamin D 2 and their corresponding 25-hydroxy metabolites in porcine liver. The vitamins and metabolites were estimated by extracting the non-saponifiable lipids from the saponifiable lipids from the samples. This was followed by purification and separation of the vitamin D 2 and vitamin D 3 from their 25-hydroxy metabolites using a 3 ml Bond Elut SCX column that was impregnated with silver nitrate. The two fractions were further purified on a Resolve cyanopropyl HPLC column. This column does not separate vitamin D 2 and vitamin D 3 but will separate 25-hydroxyvitamin D 2 from 25-hydroxyvitamin D 2 . Quantitation used Nova Pak C-18 and Resolve C-18 HPLC columns in series, measuring the absorbance at 254 nm. This gave baseline separation of vitamin D 2 and vitamin D 3 . Recoveries were determined by adding 3 H-vitamin D 3 and 3 H-25-hydroxyvitamin D 3 before saponification and assuming similar recoveries for the vitamin D 2 and 25-hydroxyvitamin D 2 . The method was found to be reproducible when a sample was minced and subdivided. The range of vitamin D 3 in liver was 5.2 to 14.0 ng/g. Vitamin D 2 , 25-hydroxyvitamin D 2 were not detectable. Preliminary results indicate the method may also be used with muscle, kidney and adipose, with adipose having a much higher level of vitamin D 3 than liver

  16. Covalent triazine framework-1 as adsorbent for inline solid phase extraction-high performance liquid chromatographic analysis of trace nitroimidazoles in porcine liver and environmental waters.

    Science.gov (United States)

    Zhong, Cheng; Chen, Beibei; He, Man; Hu, Bin

    2017-02-03

    In this study, covalent triazine framework-1 (CTF-1) was adopted as solid phase extraction (SPE) sorbents, and a method of SPE inline coupled with high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for trace analysis of three nitroimidazolaes (including metronidazole, ronidazole and dimetridazole) in porcine liver and environmental water samples. CTF-1 has rich π-electron and N containing triazine, thus can form π-π interaction and intermolecular hydrogen bond with three target polar nitroimidazoles, resulting in high extraction efficiency (87%-98%). Besides, CTF-1 has large specific area, which benefits rapid mass transfer and low column pressure, leading to fast adsorption/desorption dynamics. Several parameters affecting inline SPE including pH, sample flow rate, sample volume, desorption reagents, elution flow rate, elution volume, and ionic strength were investigated. Under the optimal experimental conditions, the limits of detection (S/N=3) were found to be in the range of 0.11-0.13μg/L. The enrichment factors (EFs) ranged from 52 to 59 fold (theoretical EF was 60-fold). The relative standard deviations were in the range of 4.3-9.4% (n=7, c=1μg/L), and the linear range was 0.5-500μg/L for three target analytes. The sample throughput is 7/h. The proposed method was successfully applied to the analysis of nitroimidazoles in porcine liver and environmental water samples with good recoveries for the spiked samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Development of left ventricular hypertrophy in a novel porcine model of mitral regurgitation

    DEFF Research Database (Denmark)

    Ravn, Nathja; Zois, Nora Elisabeth; Moesgaard, Sophia Gry

    2014-01-01

    OBJECTIVES: We aimed to develop a porcine model for chronic nonischemic mitral regurgitation (MR) to investigate left ventricular (LV) enlargement and eccentric hypertrophy. DESIGN: Nonischemic MR was induced in 30 pigs by open-chest immobilization of the posterior mitral leaflet by transannular...... (LVIDd) from baseline to follow-up was significantly higher in the sMR group compared to that of the control group (P = 0.0017). Furthermore, LV weight was significantly increased in the mMR (P = 0.047) and the sMR (P = 0.0087) groups compared to that of the control group. CONCLUSIONS: A new model...

  18. Nicotine permeability across the buccal TR146 cell culture model and porcine buccal mucosa in vitro

    DEFF Research Database (Denmark)

    Nielsen, Hanne Mørck; Rassing, Margrethe Rømer

    2002-01-01

    The present study was conducted to investigate and compare the effect of pH and drug concentration on nicotine permeability across the TR146 cell culture model and porcine buccal mucosa in vitro. As a further characterization of the TR146 cell culture model, it was explored whether the results were...... comparable for bi-directional and uni-directional transport in the presence of a transmembrane pH gradient. Nicotine concentrations between 10(-5) and 10(-2) M were applied to the apical side of the TR146 cell culture model or the mucosal side of porcine buccal mucosa. Buffers with pH values of 5.5, 7.......4 and 8.1 were used to obtain different fractions of non- and mono-ionized nicotine. The apparent permeability (P(app)) of nicotine across both models increased significantly with increasing pH, and the P(app) values obtained with the two models could be correlated in a linear manner. With increasing...

  19. Chronic Porcine Two-Hit Model with Hemorrhagic Shock and textitPseudomonas aeruginosa Sepsis

    OpenAIRE

    Eissner, B.;Matz, K.;Smorodchenko, A.;Röschmann, A.;Specht, B. U. v.

    2016-01-01

    Background: Sepsis is still a major cause of death despite well-developed therapeutical strategies such as antibiotics and supportive medication. The aim of this study was to characterize the long-term effects of a two-hit porcine sepsis model with a hemorrhagic shock as ‘first hit’ followed by a Pseudomonas aeruginosa infusion as ‘second hit’. Materials and Methods: Twelve juvenile healthy pigs were anesthetized and hemodynamically monitored. The two-hit group (n = 6) underwent a hemorrhagic...

  20. Porcine cadaver iris model for iris heating during corneal surgery with a femtosecond laser

    Science.gov (United States)

    Sun, Hui; Fan, Zhongwei; Wang, Jiang; Yan, Ying; Juhasz, Tibor; Kurtz, Ron

    2015-03-01

    Multiple femtosecond lasers have now been cleared for use for ophthalmic surgery, including for creation of corneal flaps in LASIK surgery. Preliminary study indicated that during typical surgical use, laser energy may pass beyond the cornea with potential effects on the iris. As a model for laser exposure of the iris during femtosecond corneal surgery, we simulated the temperature rise in porcine cadaver iris during direct illumination by the femtosecond laser. Additionally, ex-vivo iris heating due to femtosecond laser irradiation was measured with an infrared thermal camera (Fluke corp. Everett, WA) as a validation of the simulation.

  1. Brief report: biomarkers of aortic vascular prosthetic graft infection in a porcine model with Staphylococcus aureus

    DEFF Research Database (Denmark)

    Langerhuus, S. N.; Tønnesen, E. K.; Jensen, K. H.

    2010-01-01

    Aortic vascular prosthetic graft infection (AVPGI) with Staphylococcus aureus is a feared post-operative complication. This study was conducted to evaluate the clinical signs and potential biomarkers of infection in a porcine AVPGI model. The biomarkers evaluated were: C-reactive protein (CRP......), fibrinogen, white blood cells (WBC), major histocompatibility complex II (MHC II) density, lymphocyte CD4:CD8 ratio and tumour necrosis factor-alpha (TNF-α) in vitro responsiveness. Sixteen pigs were included in the study, and randomly assigned into four groups (n = 4): “SHAM” pigs had their infra...

  2. Ideal Experimental Rat Models for Liver Diseases

    OpenAIRE

    Lee, Sang Woo; Kim, Sung Hoon; Min, Seon Ok; Kim, Kyung Sik

    2011-01-01

    There are many limitations for conducting liver disease research in human beings due to the high cost and potential ethical issues. For this reason, conducting a study that is difficult to perform in humans using appropriate animal models, can be beneficial in ascertaining the pathological physiology, and in developing new treatment modalities. However, it is difficult to determine the appropriate animal model which is suitable for research purposes, since every patient has different and dive...

  3. Insights into coronary collateral formation from a novel porcine semiacute infarction model.

    Science.gov (United States)

    Krackhardt, Florian; Harnoss, Jonathan M; Waliszewski, Matthias W; Ritter, Zully; Granzow, Susanne; Felsenberg, Dieter; Neumann, Konrad; Lerman, Lilian O; Hillmeister, Philipp; Gebker, Rolf; Paetsch, Ingo; Riediger, Fabian; Bramlage, Peter; Buschmann, Ivo R

    2018-03-01

    For patients with severe ischemic heart disease, complete revascularization by a percutaneous coronary intervention or coronary artery bypass grafting is often not achieved and may still cause residual angina. In case of progressive coronary artery occlusions, therapeutic arteriogenesis constitutes a promising strategy for increasing blood supply to the ischemic myocardium. Whether the formation of collaterals in the hypofused myocardium is angiogenetic in nature or based on preformed coronary artery anastomoses remains debatable. The objectives of this research were (i) the development of an appropriate research methodology to study a humanoid animal semiacute infarction model with low mortality and (ii) to answer the question of whether collateral revascularization follows a pre-existing 'blueprint'. A porcine model was chosen in which a step-wise vessel occlusion was performed by implantation of a copper stent into the distal left anterior descending artery. Vessel occlusion and collateral development were confirmed in vivo every 14 days up to day 56 by repeated coronary angiography and myocardial perfusion measurement using cardiac MRI. After the completion of the in-vivo imaging studies, animals were euthanized and collateral growth was evaluated using microcomputer tomography. Our porcine model of semiacute noninvasive coronary artery occlusion confirmed the existence of preformed coronary anastomoses and the proliferation of functional vessels in hypoperfused myocardium. Repetitive intra-animal MRIs showed the functional impact of these growing collaterals. The confirmation of preformed coronary anastomoses during the process of collateralization (natural bypasses) offers a preclinical avenue to carry out arteriogenetic pharmaceutical research in patients with ischemic heart disease.

  4. Establishment of a porcine model of patent foramen ovale

    International Nuclear Information System (INIS)

    Jiang Weijian; Xiao Xiangsheng

    2007-01-01

    Objective: To investigate the feasibility of developing an animal model of patent foramen ovale (PFO) in piglets by percutaneous atrial septal puncture and balloon dilation. Methods: A standardized percutaneous atrial trans-septal puncture and balloon dilation was conducted in eleven healthy piglets under general anesthesia. A Rups-100 system inserted through a femoral vein was used for the trans-septal puncture, and subsequent balloon dilatation was performed at the puncture site to imitate a PFO. Euthanasia and autopsy were performed on day-1 in 1 piglet (early autopsy), and on day-21 in the remaining 10 piglets (late autopsy). Results: Artificial PFO was successfully created in all piglets and verified by fluoroscopy. No major technical difficulty or complication was encountered except in one which developed mild hemopericardium. In the piglet which had early autopsy, the artificial foramen was measured 0.8 cm x 0.7 cm in cross-section and aggregates of erythrocytes were revealed over its rim under light microscopy. In the late autopsy group (n=10), 7 piglets had the created foramens healed and sealed off; while the other 3 showed relatively small residual lumens measuring 0.1 cm x 0.2 cm, 0.2 cm x 0.2 cm and 0.1 cm x 0.3 cm in cross-section respectively. Histological examination of specimens from the late autopsy group showed variable neointima hyperplasia, loss of neointima, infiltration of lymphocytes, focal hydropic degeneration of cardiac muscle, and focal fibrosis of interstitium at the immediate vicinity of regardless of the course of healing. Conclusion: Artificial creation of PFO in piglets is feasible by percutaneous atrial septal puncture and balloon dilation. This protocol may serve as a research model for PFO-related stroke in human. (authors)

  5. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    Science.gov (United States)

    Mommsen, Philipp; Pfeifer, Roman; Mohr, Juliane; Ruchholtz, Steffen; Flohé, Sascha; Fröhlich, Matthias; Keibl, Claudia; Seekamp, Andreas; Witte, Ingo

    2015-01-01

    Background. The deterioration of hemodynamics instantly endangers the patients' life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C) was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals' hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia. PMID:26170533

  6. Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

    Directory of Open Access Journals (Sweden)

    Matthias Weuster

    2015-01-01

    Full Text Available Background. The deterioration of hemodynamics instantly endangers the patients’ life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals’ hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia.

  7. Irreversible electroporation of the pancreas is feasible and safe in a porcine survival model.

    Science.gov (United States)

    Fritz, Stefan; Sommer, Christof M; Vollherbst, Dominik; Wachter, Miguel F; Longerich, Thomas; Sachsenmeier, Milena; Knapp, Jürgen; Radeleff, Boris A; Werner, Jens

    2015-07-01

    Use of thermal tumor ablation in the pancreatic parenchyma is limited because of the risk of pancreatitis, pancreatic fistula, or hemorrhage. This study aimed to evaluate the feasibility and safety of irreversible electroporation (IRE) in a porcine model. Ten pigs were divided into 2 study groups. In the first group, animals received IRE of the pancreatic tail and were killed after 60 minutes. In the second group, animals received IRE at the head of the pancreas and were followed up for 7 days. Clinical parameters, computed tomography imaging, laboratory results, and histology were obtained. All animals survived IRE ablation, and no cardiac adverse effects were noted. Sixty minutes after IRE, a hypodense lesion on computed tomography imaging indicated the ablation zone. None of the animals developed clinical signs of acute pancreatitis. Only small amounts of ascites fluid, with a transient increase in amylase and lipase levels, were observed, indicating that no pancreatic fistula occurred. This porcine model shows that IRE is feasible and safe in the pancreatic parenchyma. Computed tomography imaging reveals significant changes at 60 minutes after IRE and therefore might serve as an early indicator of therapeutic success. Clinical studies are needed to evaluate the efficacy of IRE in pancreatic cancer.

  8. A novel porcine model of ventilator-associated pneumonia caused by oropharyngeal challenge with Pseudomonas aeruginosa.

    Science.gov (United States)

    Li Bassi, Gianluigi; Rigol, Montserrat; Marti, Joan-Daniel; Saucedo, Lina; Ranzani, Otavio T; Roca, Ignasi; Cabanas, Maria; Muñoz, Laura; Giunta, Valeria; Luque, Nestor; Rinaudo, Mariano; Esperatti, Mariano; Fernandez-Barat, Laia; Ferrer, Miquel; Vila, Jordi; Ramirez, Jose; Torres, Antoni

    2014-05-01

    Animal models of ventilator-associated pneumonia (VAP) in primates, sheep, and pigs differ in the underlying pulmonary injury, etiology, bacterial inoculation methods, and time to onset. The most common ovine and porcine models do not reproduce the primary pathogenic mechanism of the disease, through the aspiration of oropharyngeal pathogens, or the most prevalent human etiology. Herein the authors characterize a novel porcine model of VAP due to aspiration of oropharyngeal secretions colonized by Pseudomonas aeruginosa. Ten healthy pigs were intubated, positioned in anti-Trendelenburg, and mechanically ventilated for 72 h. Three animals did not receive bacterial challenge, whereas in seven animals, a P. aeruginosa suspension was instilled into the oropharynx. Tracheal aspirates were cultured and respiratory mechanics were recorded. On autopsy, lobar samples were obtained to corroborate VAP through microbiological and histological studies. In animals not challenged, diverse bacterial colonization of the airways was found and monolobar VAP rarely developed. In animals with P. aeruginosa challenge, colonization of tracheal secretion increased up to 6.39 ± 0.34 log colony-forming unit (cfu)/ml (P VAP was confirmed in six of seven pigs, in 78% of the cases developed in the dependent lung segments (right medium and lower lobes, P = 0.032). The static respiratory system elastance worsened to 41.5 ± 5.8 cm H2O/l (P = 0.001). The authors devised a VAP model caused by aspiration of oropharyngeal P. aeruginosa, a frequent causative pathogen of human VAP. The model also overcomes the practical and legislative limitations associated with the use of primates. The authors' model could be employed to study pathophysiologic mechanisms, as well as novel diagnostic/preventive strategies.

  9. A Novel Porcine Model of Septic Shock Induced by Acute Respiratory Distress Syndrome due to Methicillin-resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    2017-01-01

    Conclusions: In the present study, we developed a novel porcine model of septic shock induced by ARDS due to severe MRSA pneumonia with characteristic hyperdynamic and hypodynamic phases in 24 h, which mimicked the hemodynamic changing of septic shock in human.

  10. Putative biomarkers for evaluating antibiotic treatment: an experimental model of porcine Actinobacillus pleuropneumoniae infection

    DEFF Research Database (Denmark)

    Lauritzen, B.; Lykkesfeldt, J.; Skaanild, M.T.

    2003-01-01

    Biomarkers of infection were screened for their possible role as evaluators of antibiotic treatment in an aerosol infection model of porcine pneumonia caused by Actinobacillus pleuropneumoniae (Ap). Following infection of 12 pigs, clinical signs of pneumonia developed within 20 h, whereafter...... antibiotic treatment of acute Ap-infection ill pigs. The present model provides a valuable tool in the evaluation of antibiotic treatments, offering the advantage of clinical and pathological examinations combined with the use of biochemical infection markers....... recovered clinically within 24h after treatment, whereas tiamulin-treated animals remained clinically ill until the end of the study, 48 h after treatment. A similar Picture was seen for the biomarkers of infection. During the infection period, plasma C-reactive protein (CRP), interleukin-6 and haptoglobin...

  11. Ideal Experimental Rat Models for Liver Diseases.

    Science.gov (United States)

    Lee, Sang Woo; Kim, Sung Hoon; Min, Seon Ok; Kim, Kyung Sik

    2011-05-01

    There are many limitations for conducting liver disease research in human beings due to the high cost and potential ethical issues. For this reason, conducting a study that is difficult to perform in humans using appropriate animal models, can be beneficial in ascertaining the pathological physiology, and in developing new treatment modalities. However, it is difficult to determine the appropriate animal model which is suitable for research purposes, since every patient has different and diverse clinical symptoms, adverse reactions, and complications due to the pathological physiology. Also, it is not easy to reproduce identically various clinical situations in animal models. Recently, the Guide for the Care and Use of Laboratory Animals has tightened up the regulations, and therefore it is advisable to select the appropriate animals and decide upon the appropriate quantities through scientific and systemic considerations before conducting animal testing. Therefore, in this review article the authors examined various white rat animal testing models and determined the appropriate usable rat model, and the pros and cons of its application in liver disease research. The authors believe that this review will be beneficial in selecting proper laboratory animals for research purposes.

  12. Comparison of Acute Thrombogenicity for Magnesium versus Stainless Steel Stents in a Porcine Arteriovenous Shunt Model.

    Science.gov (United States)

    Lipinski, Michael J; Acampado, Eduardo; Cheng, Qi; Adams, Lila; Torii, Sho; Gai, Jiaxiang; Torguson, Rebecca; Hellinga, David G; Joner, Michael; Harder, Claus; Zumstein, Philine; Finn, Aloke V; Kolodgie, Frank D; Virmani, Renu; Waksman, Ron

    2018-05-08

    Aims The aetiology for reduced thrombogenicity of the Magmaris resorbable magnesium scaffold (RMS) when compared with the Absorb bioresorbable vascular scaffold remains unclear. We therefore investigated whether the Magmaris RMS has platelet-repelling properties by comparing its acute thrombogenicity with an equivalent stainless steel stent in an arteriovenous shunt model. Methods and Results An ex vivo porcine carotid jugular arteriovenous shunt was established and connected to Sylgard tubing containing the Magmaris RMS with sirolimus-eluting PLLA coating and an equivalent 316L stainless steel stent with sirolimus-eluting PLLA coating. Six shunts (2 shunt runs per pig) were run comparing the 2 scaffolds (n=9) in alternating order. Nested generalised linear mixed models were employed to compare variables between scaffold groups. Confocal fluorescent microscopy costaining CD61/CD42b demonstrated that the 316L equivalent stent had significantly greater platelet coverage of the total scaffold compared with Magmaris (5.8% vs. 2.8%, Rate ratio 2.21 [1.41, 3.47], p=0.012). Scanning electron microscopy demonstrated significantly greater thrombus deposition on the 316L equivalent stent as a percentage of the total scaffold compared with Magmaris (8.0% vs. 5.3%, p=0.009). Magmaris also had significantly less CD14 positive monocyte deposition and a trend toward less PM-1 positive neutrophil compared with the 316L equivalent stent. Conclusion Despite having identical scaffold characteristics regarding geometrical design, Magmaris had significantly less thrombogenicity and inflammatory cell deposition compared with the equivalent 316L stainless steel stent in a porcine arteriovenous shunt model. These data suggest resorbable magnesium scaffolds may have inherent properties that reduce adhesion of platelets and inflammatory cells.

  13. Combined in vivo and ex vivo analysis of mesh mechanics in a porcine hernia model.

    Science.gov (United States)

    Kahan, Lindsey G; Lake, Spencer P; McAllister, Jared M; Tan, Wen Hui; Yu, Jennifer; Thompson, Dominic; Brunt, L Michael; Blatnik, Jeffrey A

    2018-02-01

    Hernia meshes exhibit variability in mechanical properties, and their mechanical match to tissue has not been comprehensively studied. We used an innovative imaging model of in vivo strain tracking and ex vivo mechanical analysis to assess effects of mesh properties on repaired abdominal walls in a porcine model. We hypothesized that meshes with dissimilar mechanical properties compared to native tissue would alter abdominal wall mechanics more than better-matched meshes. Seven mini-pigs underwent ventral hernia creation and subsequent open repair with one of two heavyweight polypropylene meshes. Following mesh implantation with attached radio-opaque beads, fluoroscopic images were taken at insufflation pressures from 5 to 30 mmHg on postoperative days 0, 7, and 28. At 28 days, animals were euthanized and ex vivo mechanical testing performed on full-thickness samples across repaired abdominal walls. Testing was conducted on 13 mini-pig controls, and on meshes separately. Stiffness and anisotropy (the ratio of stiffness in the transverse versus craniocaudal directions) were assessed. 3D reconstructions of repaired abdominal walls showed stretch patterns. As pressure increased, both meshes expanded, with no differences between groups. Over time, meshes contracted 17.65% (Mesh A) and 0.12% (Mesh B; p = 0.06). Mesh mechanics showed that Mesh A deviated from anisotropic native tissue more than Mesh B. Compared to native tissue, Mesh A was stiffer both transversely and craniocaudally. Explanted repaired abdominal walls of both treatment groups were stiffer than native tissue. Repaired tissue became less anisotropic over time, as mesh properties prevailed over native abdominal wall properties. This technique assessed 3D stretch at the mesh level in vivo in a porcine model. While the abdominal wall expanded, mesh-ingrown areas contracted, potentially indicating stresses at mesh edges. Ex vivo mechanics demonstrate that repaired tissue adopts mesh properties, suggesting

  14. Functional recovery after experimental RPE debridement, mfERG studies in a porcine model

    DEFF Research Database (Denmark)

    Sørensen, Nina Buus; Lassota, Nathan; Kyhn, Maria Voss

    2013-01-01

    BACKGROUND: The correlation between histologically identified regeneration of retinal pigment epithelium (RPE) and functional outcome measured by multifocal electroretinography (mfERG) following surgical debridement is examined in a porcine model. In humans, visual acuity is reduced in diseases......, and by brushing the Bruch's membrane with a silicone catheter. Immediately following surgery (baseline) and after 2 and 6 weeks respectively, the animals were examined by mfERG, fundus photographs (FPs), fluorescein angiograms (FAs), and histopathology. RESULTS: The mfERG P1 amplitude was decreased 2 weeks (T2....... CONCLUSION: This is the first study to show that the histological regeneration of hypopigmented RPE correlates to a return of the retinal function, measured by mfERG....

  15. N-Acetylcysteine and Desferoxamine Reduce Pulmonary Oxidative Stress Caused by Hemorrhagic Shock in a Porcine Model.

    Science.gov (United States)

    Mani, Alexandra; Staikou, Chryssoula; Karmaniolou, Iosifina; Orfanos, Nikolaos; Mylonas, Anastassios; Nomikos, Tzortzis; Pafiti, Agathi; Papalois, Apostolos; Arkadopoulos, Nikolaos; Smyrniotis, Vassilios; Theodoraki, Kassiani

    2017-02-01

    To investigate the pulmonary oxidative stress and possible protective effect of N-Acetylcysteine (NAC) and Desferoxamine (DFX)in a porcine model subjected to hemorrhagic shock. Twenty-one pigs were randomly allocated to Group-A (sham, n = 5), Group-B (fluid resuscitation, n = 8) and Group-C (fluid, NAC and DFX resuscitation, n = 8). Groups B and C were subjected to a 40-min shock period induced by liver trauma, followed by a 60-min resuscitation period. During shock, the mean arterial pressure (MAP) was maintained at 30-40 mmHg. Resuscitation consisted of crystalloids (35 mL/kg) and colloids (18 mL/kg) targeting to MAP normalization (baseline values ± 10%). In addition, Group-C received pretreatment with NAC 200 mg/kg plus DFX 2 g as intravenous infusions. Thiobarbituric Acid Reactive Substances (TBARS), protein carbonyls and glutathione peroxidase (GPx) activity were determined in lung tissue homogenates. Also, histological examination of pulmonary tissue specimens was performed. TBARS were higher in Group-B than in Group-A or Group-C: 2.90 ± 0.47, 0.57 ± 0.10, 1.78 ± 0.47 pmol/μg protein, respectively (p 0.05). GPx activity did not differ significantly between the three groups (p > 0.05). Lung histology was improved in Group-C versus Group-B, with less alveolar collapse, interstitial edema and inflammation. NAC plus DFX prevented the increase of pulmonary oxidative stress markers and protein damage after resuscitated hemorrhagic shock and had beneficial effect on lung histology. NAC/DFX combination may be used in the multimodal treatment of hemorrhagic shock, since it may significantly prevent free radical injury in the lung.

  16. Electroejaculation functions primarily by direct activation of pelvic musculature: Perspectives from a porcine model

    Directory of Open Access Journals (Sweden)

    Adam M.R. Groh

    2018-03-01

    Full Text Available Ejaculatory dysfunction is a significant cause of infertility in men that have incurred spinal cord injury or iatrogenic lesions to the sympathetic nerves in the retroperitoneum. For such patients, electroejaculation – whereby a voltage is applied transrectally under general anesthesia – is a highly-effective procedure to obtain ejaculate. At present, however, there remains uncertainty as to the physiological mechanism by which electroejaculation prompts seminal emission in males with neurogenic anejaculation. Thus, in the present study, we aimed to determine, for the first time, whether electroejaculation functions by mimicking a neurophysiological response, or by directly activating local pelvic musculature. Using electroejaculation in a novel porcine model, we monitored the strength of contraction of the internal urethral sphincter (a smooth muscle involved in ejaculation before and after lesioning its sympathetic innervation with a combination of progressively-worsening surgical and pharmacological insults in three anesthetized boars (46.1 ± 7.4 kg. Importantly, prior to this investigation, we confirmed the comparative structural anatomy of the porcine model to humans through gross dissection and histological analysis of the infrarenal retroperitoneal sympathetic nerves and ganglia in 18 unembalmed boars. Prior to sacrifice, three of these boars underwent functional testing to confirm control of the internal urethral sphincter by the hypogastric nerves. Our results demonstrate that electroejaculation-induced contraction of the internal urethral sphincter was preserved following each progressive neural insult compared to the control state (p > 0.05. In contrast, these same insults resulted in paralysis/paresis of the internal urethral sphincter when its sympathetic innervation was directly stimulated with bipolar electrodes (p < 0.05. Taken together, our results provide the first empirical evidence to suggest that

  17. Recellularization of rat liver: An in vitro model for assessing human drug metabolism and liver biology.

    Directory of Open Access Journals (Sweden)

    Matthew J Robertson

    Full Text Available Liver-like organoids that recapitulate the complex functions of the whole liver by combining cells, scaffolds, and mechanical or chemical cues are becoming important models for studying liver biology and drug metabolism. The advantages of growing cells in three-dimensional constructs include enhanced cell-cell and cell-extracellular matrix interactions and preserved cellular phenotype including, prevention of de-differentiation. In the current study, biomimetic liver constructs were made via perfusion decellularization of rat liver, with the goal of maintaining the native composition and structure of the extracellular matrix. We optimized our decellularization process to produce liver scaffolds in which immunogenic residual DNA was removed but glycosaminoglycans were maintained. When the constructs were recellularized with rat or human liver cells, the cells remained viable, capable of proliferation, and functional for 28 days. Specifically, the cells continued to express cytochrome P450 genes and maintained their ability to metabolize a model drug, midazolam. Microarray analysis showed an upregulation of genes involved in liver regeneration and fibrosis. In conclusion, these liver constructs have the potential to be used as test beds for studying liver biology and drug metabolism.

  18. Endoscopic intestinal bypass creation by using self-assembling magnets in a porcine model.

    Science.gov (United States)

    Ryou, Marvin; Agoston, A Tony; Thompson, Christopher C

    2016-04-01

    A purely endoluminal method of GI bypass would be desirable for the treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets that create large-caliber anastomoses (Incisionless Anastomosis System [IAS]). The aim of this study was to evaluate procedural characteristics of IAS deployment and long-term anastomotic integrity and patency. We performed a 3-month survival study of Yorkshire pigs (5 interventions, 3 controls). Intervention pigs underwent simultaneous enteroscopy/colonoscopy performed with the animals under intravenous sedation. The IAS magnets were deployed and coupled with reciprocal magnets under fluoroscopy. Every 3 to 6 days pigs underwent endoscopy until jejunocolonic anastomosis (dual-path bypass) creation and magnet expulsion. Necropsies and histological evaluation were performed. The primary endpoints were technical success; secondary endpoints of anastomosis integrity, patency, and histological characteristics were weight trends. Under intravenous sedation, endoscopic bypass creation by using IAS magnets was successfully performed in 5 of 5 pigs (100%). Given porcine anatomy, the easiest dual-path bypass to create was between the proximal jejunum and colon. The mean procedure time was 14.7 minutes. Patent, leak-free anastomoses formed by day 4. All IAS magnets were expelled by day 12. All anastomoses were fully patent at 3 months with a mean diameter of 3.5 cm. The mean 3-month weight was 45 kg in bypass pigs and 78 kg in controls (P = .01). At necropsy, adhesions were absent. Histology showed full re-epithelialization across the anastomosis without fibrosis or inflammation. Large-caliber, leak-free, foreign body-free endoscopic intestinal bypass by using IAS magnets can be safely and rapidly performed in the porcine by model using only intravenous sedation. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  19. No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers.

    Directory of Open Access Journals (Sweden)

    Won Chang

    Full Text Available To evaluate the in vivo technical feasibility, efficiency, and safety of switching bipolar (SB and switching monopolar (SM radiofrequency ablation (RFA as a no-touch ablation technique in the porcine liver.The animal care and use committee approved this animal study and 16 pigs were used in two independent experiments. In the first experiment, RFA was performed on 2-cm tumor mimickers in the liver using a no-touch technique in the SM mode (2 groups, SM1: 10 minutes, n = 10; SM2: 15 minutes, n = 10 and SB-mode (1 group, SB: 10 minutes, n = 10. The technical success with sufficient safety margins, creation of confluent necrosis, ablation size, and distance between the electrode and ablation zone margin (DEM, were compared between groups. In the second experiment, thermal injury to the adjacent anatomic organs was compared between SM-RFA (15 minutes, n = 13 and SB-RFA modes (10 minutes, n = 13.The rates of the technical success and the creation of confluent necrosis were higher in the SB group than in the SM1 groups (100% vs. 60% and 90% vs. 40%, both p < 0.05. The ablation volume in the SM2 group was significantly larger than that in the SB group (59.2±18.7 cm3 vs. 39.8±9.7 cm3, p < 0.05, and the DEM in the SM2 group was also larger than that in the SB group (1.39±0.21 cm vs. 1.07±0.10 cm, p < 0.05. In the second experiment, the incidence of thermal injury to the adjacent organs and tissues in the SB group (23.1%, 3/13 was significantly lower than that in the SM group (69.2%, 8/13 (p = 0.021.SB-RFA was more advantageous for a no-touch technique for liver tumors, showing the potential of a better safety profile than SM-RFA.

  20. Modeling the mechanical properties of liver fibrosis in rats.

    Science.gov (United States)

    Zhu, Ying; Chen, Xin; Zhang, Xinyu; Chen, Siping; Shen, Yuanyuan; Song, Liang

    2016-06-14

    The progression of liver fibrosis changes the biomechanical properties of liver tissue. This study characterized and compared different liver fibrosis stages in rats in terms of viscoelasticity. Three viscoelastic models, the Voigt, Maxwell, and Zener models, were applied to experimental data from rheometer tests and then the elasticity and viscosity were estimated for each fibrosis stage. The study found that both elasticity and viscosity are correlated with the various stages of liver fibrosis. The study revealed that the Zener model is the optimal model for describing the mechanical properties of each fibrosis stage, but there is no significant difference between the Zener and Voigt models in their performance on liver fibrosis staging. Therefore the Voigt model can still be effectively used for liver fibrosis grading. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A comprehensive computational model of sound transmission through the porcine lung.

    Science.gov (United States)

    Dai, Zoujun; Peng, Ying; Henry, Brian M; Mansy, Hansen A; Sandler, Richard H; Royston, Thomas J

    2014-09-01

    A comprehensive computational simulation model of sound transmission through the porcine lung is introduced and experimentally evaluated. This "subject-specific" model utilizes parenchymal and major airway geometry derived from x-ray CT images. The lung parenchyma is modeled as a poroviscoelastic material using Biot theory. A finite element (FE) mesh of the lung that includes airway detail is created and used in comsol FE software to simulate the vibroacoustic response of the lung to sound input at the trachea. The FE simulation model is validated by comparing simulation results to experimental measurements using scanning laser Doppler vibrometry on the surface of an excised, preserved lung. The FE model can also be used to calculate and visualize vibroacoustic pressure and motion inside the lung and its airways caused by the acoustic input. The effect of diffuse lung fibrosis and of a local tumor on the lung acoustic response is simulated and visualized using the FE model. In the future, this type of visualization can be compared and matched with experimentally obtained elastographic images to better quantify regional lung material properties to noninvasively diagnose and stage disease and response to treatment.

  2. Evaluation of regeneration of liver function in pig model of auxiliary partial liver transplantation

    International Nuclear Information System (INIS)

    Li Jiaxin; Chen Xiaopeng; Rui Ging; Shong Qun; Chen Fangman; Lu Meijing; Chen Yongquan

    2010-01-01

    Objective: To establish a pig model of auxiliary partial liver transplantation and observe the liver function regeneration of host liver and graft. Methods: The portal vein providing for the host liver were gradually contracted; the donor hepatic veins were eng-to-side anastomosed to inferior vena cava in host caudal; graft was transplanted into the space under the host liver, part of receivers relieved portal vein angiography and color Doppler flow imaging was performed 3 days after surgery. Liver function of double livers in relievers was checked up, 3 days and 1 week after surgery respectively. Results: After surgery 10 relievers survived over 1 week, blood enzymology from hepatic vein of grafts 1 week after surgery were not ameliorative significantly compared with those 3 days after surgery (P > 0.05). Blood enzymology indexes from hepatic veins of grafts 1 week after surgery were were improved significantly compared with 3 days after surgery (P < 0.05). The graft did not reveal atrophic and gained favorable function. Conclusion: Favorable regeneration in the auxiliary partial liver transplantation model has achieved. Ideal foundation has been established for simulating and investigating human auxiliary liver transplantation. (authors)

  3. Endovascular Broad-Neck Aneurysm Creation in a Porcine Model Using a Vascular Plug

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg, E-mail: gmuehlenbruch@ukaachen.de; Nikoubashman, Omid; Steffen, Bjoern; Dadak, Mete [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, University Hospital (Germany); Palmowski, Moritz [RWTH Aachen University, Department of Nuclear Medicine, University Hospital (Germany); Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, University Hospital (Germany)

    2013-02-15

    Ruptured cerebral arterial aneurysms require prompt treatment by either surgical clipping or endovascular coiling. Training for these sophisticated endovascular procedures is essential and ideally performed in animals before their use in humans. Simulators and established animal models have shown drawbacks with respect to degree of reality, size of the animal model and aneurysm, or time and effort needed for aneurysm creation. We therefore aimed to establish a realistic and readily available aneurysm model. Five anticoagulated domestic pigs underwent endovascular intervention through right femoral access. A total of 12 broad-neck aneurysms were created in the carotid, subclavian, and renal arteries using the Amplatzer vascular plug. With dedicated vessel selection, cubic, tubular, and side-branch aneurysms could be created. Three of the 12 implanted occluders, two of them implanted over a side branch of the main vessel, did not induce complete vessel occlusion. However, all aneurysms remained free of intraluminal thrombus formation and were available for embolization training during a surveillance period of 6 h. Two aneurysms underwent successful exemplary treatment: one was stent-assisted, and one was performed with conventional endovascular coil embolization. The new porcine aneurysm model proved to be a straightforward approach that offers a wide range of training and scientific applications that might help further improve endovascular coil embolization therapy in patients with cerebral aneurysms.

  4. Endovascular Broad-Neck Aneurysm Creation in a Porcine Model Using a Vascular Plug

    International Nuclear Information System (INIS)

    Mühlenbruch, Georg; Nikoubashman, Omid; Steffen, Björn; Dadak, Mete; Palmowski, Moritz; Wiesmann, Martin

    2013-01-01

    Ruptured cerebral arterial aneurysms require prompt treatment by either surgical clipping or endovascular coiling. Training for these sophisticated endovascular procedures is essential and ideally performed in animals before their use in humans. Simulators and established animal models have shown drawbacks with respect to degree of reality, size of the animal model and aneurysm, or time and effort needed for aneurysm creation. We therefore aimed to establish a realistic and readily available aneurysm model. Five anticoagulated domestic pigs underwent endovascular intervention through right femoral access. A total of 12 broad-neck aneurysms were created in the carotid, subclavian, and renal arteries using the Amplatzer vascular plug. With dedicated vessel selection, cubic, tubular, and side-branch aneurysms could be created. Three of the 12 implanted occluders, two of them implanted over a side branch of the main vessel, did not induce complete vessel occlusion. However, all aneurysms remained free of intraluminal thrombus formation and were available for embolization training during a surveillance period of 6 h. Two aneurysms underwent successful exemplary treatment: one was stent-assisted, and one was performed with conventional endovascular coil embolization. The new porcine aneurysm model proved to be a straightforward approach that offers a wide range of training and scientific applications that might help further improve endovascular coil embolization therapy in patients with cerebral aneurysms.

  5. A porcine ex vivo lung perfusion model with maximal argon exposure to attenuate ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    An Martens

    2017-01-01

    Full Text Available Argon (Ar is a noble gas with known organoprotective effects in rodents and in vitro models. In a previous study we failed to find a postconditioning effect of Ar during ex vivo lung perfusion (EVLP on warm-ischemic injury in a porcine model. In this study, we further investigated a prolonged exposure to Ar to decrease cold ischemia-reperfusion injury after lung transplantation in a porcine model with EVLP assessment. Domestic pigs (n = 6/group were pre-conditioned for 6 hours with 21% O 2 and 79% N 2 (CONTR or 79% Ar (ARG. Subsequently, lungs were cold flushed and stored inflated on ice for 18 hours inflated with the same gas mixtures. Next, lungs were perfused for 4 hours on EVLP (acellular while ventilated with 12% O 2 and 88% N 2 (CONTR group or 88% Ar (ARG group. The perfusate was saturated with the same gas mixture but with the addition of CO 2 to an end-tidal CO 2 of 35-45 mmHg. The saturated perfusate was drained and lungs were perfused with whole blood for an additional 2 hours on EVLP. Evaluation at the end of EVLP did not show significant effects on physiologic parameters by prolonged exposure to Ar. Also wet-to-dry weight ratio did not improve in the ARG group. Although in other organ systems protective effects of Ar have been shown, we did not detect beneficial effects of a high concentration of Ar on cold pulmonary ischemia-reperfusion injury in a porcine lung model after prolonged exposure to Ar in this porcine model with EVLP assessment.

  6. Per-Oral Endoscopic Myotomy (POEM) After Previous Laparoscopic Heller Myotomy Is Feasible and Safe in a Porcine Model.

    Science.gov (United States)

    Miles, Luke F; Frelich, Matthew J; Gould, Jon C; Dua, Kulwinder S; Jensen, Eric S; Kastenmeier, Andrew S

    2015-10-01

    We sought to evaluate the feasibility, safety, and difficulty of performing the per-oral endoscopic myotomy (POEM) procedure in the setting of a prior Heller myotomy using a survival porcine model. Four pigs underwent laparoscopic Heller myotomy with Dor partial anterior fundoplication followed by the POEM performed 4 weeks later. Two additional pigs served as controls, undergoing only the POEM. All procedures were completed without complications. The revisional POEM was not significantly more difficult than POEM controls based on procedure time, POEM procedure components, or procedure difficulty scores. Revisional POEM had a longer mean operative time when compared with Heller myotomy (126.0 vs. 83.8 min; PHeller myotomy is safe and feasible in the porcine model and has potential as an option for patients suffering from recurrent or persistent symptoms after failed surgical myotomy.

  7. Establishment of animal model with half-liver cirrhosis

    International Nuclear Information System (INIS)

    Yang Zhenghan; Zhou Cheng; Chen Min; Xie Jingxia; Zhang Yuewu; Hu Bifang; Mo Hongbo; Wu Xiao

    2003-01-01

    Objective: To establish a new cirrhosis model suitable for imaging study. Methods: Via a 4 F catheter, 50-100 μl of carbon tetrachloride was injected into the left or right hepatic artery of 12 dogs fortnightly. Liver functional test, imaging study, and pathological examination were performed in these dogs regularly. Results: As the times of injection increased, necrosis of hepatocytes, fibrosis, and cirrhosis of the liver aggravated. In each dog, cirrhosis was more serious in the half liver with carbon tetrachloride injection than in the other half liver without carbon tetrachloride injection. With this model, it was convenient to perform the imaging study of liver cirrhosis. Conclusion: Animal model with half-liver cirrhosis can be established by combining catheter technique and traditional method

  8. Systemic release of cytokines and heat shock proteins in porcine models of polytrauma and hemorrhage

    Science.gov (United States)

    Baker, Todd A.; Romero, Jacqueline; Bach, Harold H.; Strom, Joel A.; Gamelli, Richard L.; Majetschak, Matthias

    2011-01-01

    Objective To define systemic release kinetics of a panel of cytokines and heat shock proteins (HSP) in porcine polytrauma/hemorrhage models and to evaluate whether they could be useful as early trauma biomarkers. Design and Setting Prospective study in a research laboratory. Subjects Twenty-one Yorkshire pigs. Measurements and Main Results Pigs underwent polytrauma (femur fractures/lung contusion, P), hemorrhage (mean arterial pressure 25-30mmHg, H), polytrauma plus hemorrhage (P/H) or sham procedure (S). Plasma was obtained at baseline, in 5-15min intervals during a 60min shock period without intervention and in 60-120min intervals during fluid resuscitation for up to 300min. Plasma was assayed for IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12/IL-23p40, IL-13, IL-17, IL-18, IFNγ, TGFβ, TNFα, HSP40, HSP70 and HSP90 by ELISA. All animals after S, P and H survived (n=5/group). Three of six animals after P/H died. IL-10 increased during shock after P and this increase was attenuated after H. TNFα increased during the shock period after P, H and also after S. P/H abolished the systemic IL-10 and TNFα release and resulted in 20-30% increased levels of IL-6 during shock. As fluid resuscitation was initiated TNFα and IL-10 levels decreased after P, H and P/H, HSP 70 increased after P, IL-6 levels remained elevated after P/H and also increased after P and S. Conclusions Differential regulation of the systemic cytokine release after polytrauma and/or hemorrhage, in combination with the effects of resuscitation, can explain the variability and inconsistent association of systemic cytokine/HSP levels with clinical variables in trauma patients. Insults of major severity (P/H) partially suppress the systemic inflammatory response. The plasma concentrations of the measured cytokines/HSPs do not reflect injury severity or physiological changes in porcine trauma models and are unlikely to be able to serve as useful trauma biomarkers in patients. PMID:21983369

  9. Anti-Inflammatory Effect of Gallic Acid-Eluting Stent in a Porcine Coronary Restenosis Model

    Science.gov (United States)

    Seob Lim, Kyung; Park, Jun-Kyu; Ho Jeong, Myung; Ho Bae, In; Sung Park, Dae; Won Shim, Jae; Ha Kim, Jung; Kuk Kim, Hyun; Soo Kim, Sung; Sun Sim, Doo; Joon Hong, Young; Han Kim, Ju; Ahn, Youngkeun

    2018-01-01

    Background Gallic acid (3,4,5-trihydroxybenzoic acid) is a natural polyphenol and strong natural antioxidant found abundantly in red wine and green tea. The aim of this study was to examine the anti-inflammatory effect of a novel gallic acid-eluting stent in a porcine coronary restenosis model. Methods Fifteen pigs were randomized into three groups; in which a total of 30 coronary arteries (10 in each group) were implanted with gallic acid-eluting stents (GESs, n = 10), gallic acid and sirolimus-eluting stents (GSESs, n = 10), or sirolimus-eluting stents (SESs, n = 10). Histopathologic analysis was performed 28 days after stenting. Results There were no significant differences in injury score and fibrin score among the groups, however there were significant differences in the internal elastic lamina (4.0 ± 0.83 mm2 in GES vs. 3.0 ± 0.53 mm2 in GSES vs. 4.6 ± 1.43 mm2 in SES, p < 0.0001), lumen area (2.3 ± 0.49 mm2 in GES vs. 1.9 ± 0.67 mm2 in GSES vs. 2.9 ± 0.56 mm2 in SES, p < 0.0001), neointimal area (1.7 ± 0.63 mm2 in GES vs. 1.1 ± 0.28 mm2 in GSES vs. 1.7 ± 1.17 mm2 in SES, p < 0.05), and percent area of stenosis (42.4% ± 9.22% in GES vs. 38.2% ± 12.77% in GSES vs. 33.9% ± 15.64% in SES, p < 0.05). The inflammation score was significantly lower in the GES and GSES groups compared to that in the SES group [1.0 (range: 1.0 to 2.0) in GES vs. 1.0 (range: 1.0 to 1.0) in GSES vs. 1.5 (range: 1.0 to 3.0) in SES, p < 0.05]. Conclusions The GES group had a greater percent area of stenosis than the SES group. Although gallic acid in the GES and GSES groups did not show a synergistic effect in suppressing neointimal hyperplasia, it resulted in greater inhibition of the inflammatory reaction in the porcine coronary restenosis model than in the SES group. PMID:29844643

  10. Bioengineered Liver Models for Drug Testing and Cell Differentiation Studies

    Directory of Open Access Journals (Sweden)

    Gregory H. Underhill

    2018-01-01

    Full Text Available In vitro models of the human liver are important for the following: (1 mitigating the risk of drug-induced liver injury to human beings, (2 modeling human liver diseases, (3 elucidating the role of single and combinatorial microenvironmental cues on liver cell function, and (4 enabling cell-based therapies in the clinic. Methods to isolate and culture primary human hepatocytes (PHHs, the gold standard for building human liver models, were developed several decades ago; however, PHHs show a precipitous decline in phenotypic functions in 2-dimensional extracellular matrix–coated conventional culture formats, which does not allow chronic treatment with drugs and other stimuli. The development of several engineering tools, such as cellular microarrays, protein micropatterning, microfluidics, biomaterial scaffolds, and bioprinting, now allow precise control over the cellular microenvironment for enhancing the function of both PHHs and induced pluripotent stem cell–derived human hepatocyte-like cells; long-term (4+ weeks stabilization of hepatocellular function typically requires co-cultivation with liver-derived or non–liver-derived nonparenchymal cell types. In addition, the recent development of liver organoid culture systems can provide a strategy for the enhanced expansion of therapeutically relevant cell types. Here, we discuss advances in engineering approaches for constructing in vitro human liver models that have utility in drug screening and for determining microenvironmental determinants of liver cell differentiation/function. Design features and validation data of representative models are presented to highlight major trends followed by the discussion of pending issues that need to be addressed. Overall, bioengineered liver models have significantly advanced our understanding of liver function and injury, which will prove useful for drug development and ultimately cell-based therapies.

  11. A novel ex-vivo porcine renal xenotransplantation model using a pulsatile machine preservation system.

    Science.gov (United States)

    Guarrera, James V; Stone, Jonathan; Tulipan, Jacob; Jhang, Jeffrey; Arrington, Ben; Boykin, Jason; Markowitz, Glen; Ratner, Lloyd E

    2011-01-01

    Animal models to investigate pathophysiology and xenotransplantation require complex techniques and significant animal utilization. The aim of the study was to develop a reliable ex-vivo technique to test xenotransplant interventions. Miniature Swine being utilized for a nonsurvival study acted as donor animals. Kidneys were flushed and rapidly explanted and chilled to 4°C. Kidneys were assigned to be the control (CK) (n=3) and the mate were used as a Xenograft Kidneys (XK) (n=3). Kidneys were perfused on separate Waters RM 3 perfusion devices. Perfusion temperature was 35-37°C and pressure was 100-110/60-70 mmHg at 60 pulses per minute. CKs were reperfused with autologous blood collected at the time of organ procurement. XKs were reperfused using freshly donated whole human blood. Physical characteristics, urine output were recorded. Core needle biopsies were obtained and examined by a blinded pathologist for evidence of antibody mediated rejection. XK kidneys demonstrated homogenous reperfusion which rapidly became patchy at 5-7 minutes. XK kidneys had become complete black and thrombosed by 60-70 minutes. XK biopsies demonstrated peritubular capillaritis. CK kidneys demonstrated homogenous reperfusion and urine production. H&E stain of CKs only demonstrated nonspecific inflammation. Our ex-vivo porcine xenotransplant model shows early promise as a tool for studying Xeno- associated hyperacute rejection. This technique saves resources and animal utilization.

  12. Assessment of motor recovery and MRI correlates in a porcine spinal cord injury model

    Directory of Open Access Journals (Sweden)

    Igor Šulla

    2014-01-01

    Full Text Available The study concentrated on behavioral and magnetic resonance imaging (MRI characteristics in a porcine spinal cord injury model. Six adult minipigs weighing 32–35 kg were narcotized by thiopental, intubated, and placed on a volume-cycled ventilator. Anaesthesia was maintained by 1.5% sevoflurane with oxygen. Following location of the 1st lumbar vertebra animals were fastened in an immobilization frame. The spinal cord, exposed through a laminectomy, was compressed by a 5 mm thick circular rod with a peak force of 0.8 kg at a velocity of 3 cm·s-1. The next day the minipigs were paraplegic but improved rapidly to paraparesis. On the 12th postoperative day they were euthanasied. Neural tissue changes were evaluated by post mortem MRI, which showed damage to the spinal cord white and/or gray matter in the epicentre of compression with longitudinal spreading over one segment cranially and caudally. Statistical analyses performed by Spearman’s rho test revealed positive correlations between damaged areas and the whole area of the spinal cord white/gray matter (P = 0.047; rs = 0.742 and (P = 0.002; rs = 0.943, respectively. The study confirmed the reliability and reproducibility of the utilised model of spinal cord trauma. The structural changes in the epicentre of injury did not impede the rapid but incomplete recovery of motor functions.

  13. Models of alcoholic liver disease in rodents: a critical evaluation

    DEFF Research Database (Denmark)

    de la M. Hall, P.; Lieber, C.S.; De Carli, L.M.

    2001-01-01

    ) Lieber-DeCarli liquid diet for alcohol-induced liver injury in rats, by C. S. Lieber and L. M. DeCarli; (3) Tsukamoto-French model of alcoholic liver injury, by S. W. French; (4) Animal models to study endotoxin-ethanol interactions, by K. O. Lindros and H. Järveläinen; and (5) Jejunoileal bypass...

  14. Allogeneic amniotic membrane-derived mesenchymal stromal cell transplantation in a porcine model of chronic myocardial ischemia

    Directory of Open Access Journals (Sweden)

    Kimura M

    2012-01-01

    Full Text Available Introduction. Amniotic membrane contains a multipotential stem cell population and is expected to possess the machinery to regulate immunological reactions. We investigated the safety and efficacy of allogeneic amniotic membrane-derived mesenchymal stromal cell (AMSC transplantation in a porcine model of chronic myocardial ischemia as a preclinical trial. Methods. Porcine AMSCs were isolated from amniotic membranes obtained by cesarean section just before delivery and were cultured to increase their numbers before transplantation. Chronic myocardial ischemia was induced by implantation of an ameroid constrictor around the left circumflex coronary artery. Four weeks after ischemia induction, nine swine were assigned to undergo either allogeneic AMSC transplantation or normal saline injection. Functional analysis was performed by echocardiography, and histological examinations were carried out by immunohistochemistry 4 weeks after AMSC transplantation. Results. Echocardiography demonstrated that left ventricular ejection fraction was significantly improved and left ventricular dilatation was well attenuated 4 weeks after AMSC transplantation. Histological assessment showed a significant reduction in percentage of fibrosis in the AMSC transplantation group. Injected allogeneic green fluorescent protein (GFP-expressing AMSCs were identified in the immunocompetent host heart without the use of any immunosuppressants 4 weeks after transplantation. Immunohistochemistry revealed that GFP colocalized with cardiac troponin T and cardiac troponin I. Conclusions. We have demonstrated that allogeneic AMSC transplantation produced histological and functional improvement in the impaired myocardium in a porcine model of chronic myocardial ischemia. The transplanted allogeneic AMSCs survived without the use of any immunosuppressants and gained cardiac phenotype through either their transdifferentiation or cell fusion.

  15. Thermal Ablation of the Pancreas With Intraoperative High-Intensity Focused Ultrasound: Safety and Efficacy in a Porcine Model.

    Science.gov (United States)

    Dupré, Aurélien; Melodelima, David; Pflieger, Hannah; Chen, Yao; Vincenot, Jérémy; Kocot, Anthony; Langonnet, Stéphan; Rivoire, Michel

    2017-02-01

    New focal destruction technologies such as high-intensity focused ultrasound (HIFU) may improve the prognosis of pancreatic ductal adenocarcinoma. Our objectives were to demonstrate the safety and efficacy of intraoperative pancreatic HIFU ablation in a porcine model. In a porcine model (N = 12), a single HIFU ablation was performed in either the body or tail of the pancreas, distant to superior mesenteric vessels. All animals were sacrificed on the eighth day. The primary objective was to obtain an HIFU ablation measuring at least 1 cm without premature death. In total, 12 HIFU ablations were carried out. These ablations were performed within 160 seconds and on average measured 20 (15-27) × 16 (8-26) mm. The primary objective was fulfilled in all but 1 pig. There were no premature deaths or severe complications. High-intensity focused ultrasound treatment was associated with a transitory increase in amylase and lipase levels, and pseudocysts were observed in half of the pigs without being clinically apparent. All ablations were well delimited at both gross and histological examinations. Intraoperative thermal destruction of porcine pancreas with HIFU is feasible. Reproducibility and safety have to be confirmed when applied close to mesenteric vessels and in long-term preclinical studies.

  16. A Triple Culture Model of the Blood-Brain Barrier Using Porcine Brain Endothelial cells, Astrocytes and Pericytes.

    Science.gov (United States)

    Thomsen, Louiza Bohn; Burkhart, Annette; Moos, Torben

    2015-01-01

    In vitro blood-brain barrier (BBB) models based on primary brain endothelial cells (BECs) cultured as monoculture or in co-culture with primary astrocytes and pericytes are useful for studying many properties of the BBB. The BECs retain their expression of tight junction proteins and efflux transporters leading to high trans-endothelial electric resistance (TEER) and low passive paracellular permeability. The BECs, astrocytes and pericytes are often isolated from small rodents. Larger species as cows and pigs however, reveal a higher yield, are readily available and have a closer resemblance to humans, which make them favorable high-throughput sources for cellular isolation. The aim of the present study has been to determine if the preferable combination of purely porcine cells isolated from the 6 months old domestic pigs, i.e. porcine brain endothelial cells (PBECs) in co-culture with porcine astrocytes and pericytes, would compare with PBECs co-cultured with astrocytes and pericytes isolated from newborn rats with respect to TEER value and low passive permeability. The astrocytes and pericytes were grown both as contact and non-contact co-cultures as well as in triple culture to examine their effects on the PBECs for barrier formation as revealed by TEER, passive permeability, and expression patterns of tight junction proteins, efflux transporters and the transferrin receptor. This syngenic porcine in vitro BBB model is comparable to triple cultures using PBECs, rat astrocytes and rat pericytes with respect to TEER formation, low passive permeability, and expression of hallmark proteins signifying the brain endothelium (tight junction proteins claudin 5 and occludin, the efflux transporters P-glycoprotein (PgP) and breast cancer related protein (BCRP), and the transferrin receptor).

  17. A Triple Culture Model of the Blood-Brain Barrier Using Porcine Brain Endothelial cells, Astrocytes and Pericytes.

    Directory of Open Access Journals (Sweden)

    Louiza Bohn Thomsen

    Full Text Available In vitro blood-brain barrier (BBB models based on primary brain endothelial cells (BECs cultured as monoculture or in co-culture with primary astrocytes and pericytes are useful for studying many properties of the BBB. The BECs retain their expression of tight junction proteins and efflux transporters leading to high trans-endothelial electric resistance (TEER and low passive paracellular permeability. The BECs, astrocytes and pericytes are often isolated from small rodents. Larger species as cows and pigs however, reveal a higher yield, are readily available and have a closer resemblance to humans, which make them favorable high-throughput sources for cellular isolation. The aim of the present study has been to determine if the preferable combination of purely porcine cells isolated from the 6 months old domestic pigs, i.e. porcine brain endothelial cells (PBECs in co-culture with porcine astrocytes and pericytes, would compare with PBECs co-cultured with astrocytes and pericytes isolated from newborn rats with respect to TEER value and low passive permeability. The astrocytes and pericytes were grown both as contact and non-contact co-cultures as well as in triple culture to examine their effects on the PBECs for barrier formation as revealed by TEER, passive permeability, and expression patterns of tight junction proteins, efflux transporters and the transferrin receptor. This syngenic porcine in vitro BBB model is comparable to triple cultures using PBECs, rat astrocytes and rat pericytes with respect to TEER formation, low passive permeability, and expression of hallmark proteins signifying the brain endothelium (tight junction proteins claudin 5 and occludin, the efflux transporters P-glycoprotein (PgP and breast cancer related protein (BCRP, and the transferrin receptor.

  18. Effect of skin graft thickness on scar development in a porcine burn model.

    Science.gov (United States)

    DeBruler, Danielle M; Blackstone, Britani N; McFarland, Kevin L; Baumann, Molly E; Supp, Dorothy M; Bailey, J Kevin; Powell, Heather M

    2018-06-01

    Animal models provide a way to investigate scar therapies in a controlled environment. It is necessary to produce uniform, reproducible scars with high anatomic and biologic similarity to human scars to better evaluate the efficacy of treatment strategies and to develop new treatments. In this study, scar development and maturation were assessed in a porcine full-thickness burn model with immediate excision and split-thickness autograft coverage. Red Duroc pigs were treated with split-thickness autografts of varying thickness: 0.026in. ("thin") or 0.058in. ("thick"). Additionally, the thin skin grafts were meshed and expanded at 1:1.5 or 1:4 to evaluate the role of skin expansion in scar formation. Overall, the burn-excise-autograft model resulted in thick, raised scars. Treatment with thick split-thickness skin grafts resulted in less contraction and reduced scarring as well as improved biomechanics. Thin skin autograft expansion at a 1:4 ratio tended to result in scars that contracted more with increased scar height compared to the 1:1.5 expansion ratio. All treatment groups showed Matrix Metalloproteinase 2 (MMP2) and Transforming Growth Factor β1 (TGF-β1) expression that increased over time and peaked 4 weeks after grafting. Burns treated with thick split-thickness grafts showed decreased expression of pro-inflammatory genes 1 week after grafting, including insulin-like growth factor 1 (IGF-1) and TGF-β1, compared to wounds treated with thin split-thickness grafts. Overall, the burn-excise-autograft model using split-thickness autograft meshed and expanded to 1:1.5 or 1:4, resulted in thick, raised scars similar in appearance and structure to human hypertrophic scars. This model can be used in future studies to study burn treatment outcomes and new therapies. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  19. Protective ventilation reduces Pseudomonas aeruginosa growth in lung tissue in a porcine pneumonia model.

    Science.gov (United States)

    Sperber, Jesper; Nyberg, Axel; Lipcsey, Miklos; Melhus, Åsa; Larsson, Anders; Sjölin, Jan; Castegren, Markus

    2017-08-31

    Mechanical ventilation with positive end expiratory pressure and low tidal volume, i.e. protective ventilation, is recommended in patients with acute respiratory distress syndrome. However, the effect of protective ventilation on bacterial growth during early pneumonia in non-injured lungs is not extensively studied. The main objectives were to compare two different ventilator settings on Pseudomonas aeruginosa growth in lung tissue and the development of lung injury. A porcine model of severe pneumonia was used. The protective group (n = 10) had an end expiratory pressure of 10 cm H 2 O and a tidal volume of 6 ml x kg -1 . The control group (n = 10) had an end expiratory pressure of 5 cm H 2 O and a tidal volume of 10 ml x kg -1 . 10 11 colony forming units of Pseudomonas aeruginosa were inoculated intra-tracheally at baseline, after which the experiment continued for 6 h. Two animals from each group received only saline, and served as sham animals. Lung tissue samples from each animal were used for bacterial cultures and wet-to-dry weight ratio measurements. The protective group displayed lower numbers of Pseudomonas aeruginosa (p protective group was unchanged (p protective ventilation with lower tidal volume and higher end expiratory pressure has the potential to reduce the pulmonary bacterial burden and the development of lung injury.

  20. Transparency-enhancing technology allows three-dimensional assessment of gastrointestinal mucosa: A porcine model.

    Science.gov (United States)

    Mizutani, Hiroya; Ono, Satoshi; Ushiku, Tetsuo; Kudo, Yotaro; Ikemura, Masako; Kageyama, Natsuko; Yamamichi, Nobutake; Fujishiro, Mitsuhiro; Someya, Takao; Fukayama, Masashi; Koike, Kazuhiko; Onodera, Hiroshi

    2018-02-01

    Although high-resolution three-dimensional imaging of endoscopically resected gastrointestinal specimens can help elucidating morphological features of gastrointestinal mucosa or tumor, there are no established methods to achieve this without breaking specimens apart. We evaluated the utility of transparency-enhancing technology for three-dimensional assessment of gastrointestinal mucosa in porcine models. Esophagus, stomach, and colon mucosa samples obtained from a sacrificed swine were formalin-fixed and paraffin-embedded, and subsequently deparaffinized for analysis. The samples were fluorescently stained, optically cleared using transparency-enhancing technology: ilLUmination of Cleared organs to IDentify target molecules method (LUCID), and visualized using laser scanning microscopy. After observation, all specimens were paraffin-embedded again and evaluated by conventional histopathological assessment to measure the impact of transparency-enhancing procedures. As a result, microscopic observation revealed horizontal section views of mucosa at deeper levels and enabled the three-dimensional image reconstruction of glandular and vascular structures. Besides, paraffin-embedded specimens after transparency-enhancing procedures were all assessed appropriately by conventional histopathological staining. These results suggest that transparency-enhancing technology may be feasible for clinical application and enable the three-dimensional structural analysis of endoscopic resected specimen non-destructively. Although there remain many limitations or problems to be solved, this promising technology might represent a novel histopathological method for evaluating gastrointestinal cancers. © 2018 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

  1. Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model.

    Science.gov (United States)

    Rosow, David E; Sahani, Dushyant; Strobel, Oliver; Kalva, Sanjeeva; Mino-Kenudson, Mari; Holalkere, Nagaraj S; Alsfasser, Guido; Saini, Sanjay; Lee, Susanna I; Mueller, Peter R; Fernández-del Castillo, Carlos; Warshaw, Andrew L; Thayer, Sarah P

    2005-12-01

    Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findings--compared with pathologic diagnoses-- predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia.

  2. In vivo perfusion assessment of an anastomosis surgery on porcine intestinal model (Conference Presentation)

    Science.gov (United States)

    Le, Hanh N. D.; Opferman, Justin; Decker, Ryan; Cheon, Gyeong W.; Kim, Peter C. W.; Kang, Jin U.; Krieger, Axel

    2016-04-01

    Anastomosis, the connection of two structures, is a critical procedure for reconstructive surgery with over 1 million cases/year for visceral indication alone. However, complication rates such as strictures and leakage affect up to 19% of cases for colorectal anastomoses and up to 30% for visceral transplantation anastomoses. Local ischemia plays a critical role in anastomotic complications, making blood perfusion an important indicator for tissue health and predictor for healing following anastomosis. In this work, we apply a real time multispectral imaging technique to monitor impact on tissue perfusion due to varying interrupted suture spacing and suture tensions. Multispectral tissue images at 470, 540, 560, 580, 670 and 760 nm are analyzed in conjunction with an empirical model based on diffuse reflectance process to quantify the hemoglobin oxygen saturation within the suture site. The investigated tissues for anastomoses include porcine small (jejunum and ileum) and large (transverse colon) intestines. Two experiments using interrupted suturing with suture spacing of 1, 2, and 3 mm and tension levels from 0 N to 2.5 N are conducted. Tissue perfusion at 5, 10, 20 and 30 min after suturing are recorded and compared with the initial normal state. The result indicates the contrast between healthy and ischemic tissue areas and assists the determination of suturing spacing and tension. Therefore, the assessment of tissue perfusion will permit the development and intra-surgical monitoring of an optimal suture protocol during anastomosis with less complications and improved functional outcome.

  3. Dynamic CT myocardial perfusion imaging: detection of ischemia in a porcine model with FFR verification

    Science.gov (United States)

    Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2014-03-01

    Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood ow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional ow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal ow condition was obtained with balloon completely de ated. Partial occlusion was induced by balloon in ation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction (iDose4, Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral ltering to reduce partial scan artifacts and noise variation. Absolute blood ow was calculated with a deconvolutionbased approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identi ed in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and ow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.

  4. Preliminary study of laser welding for aortic dissection in a porcine model using a diode laser with indocyanine green.

    Science.gov (United States)

    Fujita, Masanori; Morimoto, Yuji; Ohmori, Sayaka; Usami, Noriko; Arai, Tsunenori; Maehara, Tadaaki; Kikuchi, Makoto

    2003-01-01

    The objective of this study was to determine whether a dissected aorta could be welded by a diode laser with a solder using an in vitro porcine aortic dissection model. Porcine aortic strips were dissected into two flaps and the dissected faces were immersed in a solution of indocyanine green. The two flaps were pressed at 0.2 kg/cm2 with contact between the two immersed faces. The pressed flaps were irradiated with a diode laser (810 nm) at intensities of 170-425 W/cm2 for 8 seconds. The welded flaps were studied by light microscopy and the adhesive strengths were measured. The irradiated flaps were successfully welded. The breaking stress, the maximum stress recorded in a stress-strain curve, increased with increase in irradiation intensity up to 396 W/cm2 (2.7 x 10(2) mmHg) and decreased when the intensity reached 425 W/cm2. In the specimen irradiated at 396 W/cm2, the welded faces showed continuous fusion of elastin layers, while some voids were seen between the welded faces in the specimen irradiated at 425 W/cm2. The dissected porcine aortas were successfully welded using a laser with solder. The results suggest that the welded aorta can bear physiological blood pressure. Copyright 2003 Wiley-Liss, Inc.

  5. Effects of burn location and investigator on burn depth in a porcine model.

    Science.gov (United States)

    Singer, Adam J; Toussaint, Jimmy; Chung, Won Taek; Thode, Henry C; McClain, Steve; Raut, Vivek

    2016-02-01

    In order to be useful, animal models should be reproducible and consistent regardless of sampling bias, investigator creating burn, and burn location. We determined the variability in burn depth based on biopsy location, burn location and investigator in a porcine model of partial thickness burns. 24 partial thickness burns (2.5 cm by 2.5 cm each) were created on the backs of 2 anesthetized pigs by 2 investigators (one experienced, one inexperienced) using a previously validated model. In one of the pigs, the necrotic epidermis covering each burn was removed. Five full thickness 4mm punch biopsies were obtained 1h after injury from the four corners and center of the burns and stained with Hematoxylin and Eosin and Masson's trichrome for determination of burn depth by a board certified dermatopathologist blinded to burn location and investigator. Comparisons of burn depth by biopsy location, burn location and investigator were performed with t-tests and ANOVA as appropriate. The mean (SD) depth of injury to blood vessels (the main determinant of burn progression) in debrided and non-debrided pigs pooled together was 1.8 (0.3)mm, which included 75% of the dermal depth. Non-debrided burns were 0.24 mm deeper than debrided burns (Plocations, in debrided burns. Additionally, there were also no statistical differences in burn depths from midline to lateral in either of these burn types. Burn depth was similar for both investigators and among biopsy locations. Burn depth was greater for caudal locations in non-debrided burns and overall non-debrided burns were deeper than debrided burns. However, burn depth did not differ based on investigator, biopsy site, and medial-lateral location. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  6. Establishment of animal model of dual liver transplantation in rat.

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    Full Text Available The animal model of the whole-size and reduced-size liver transplantation in both rat and mouse has been successfully established. Because of the difficulties and complexities in microsurgical technology, the animal model of dual liver transplantation was still not established for twelve years since the first human dual liver transplantation has been made a success. There is an essential need to establish this animal model to lay a basic foundation for clinical practice. To study the physiological and histopathological changes of dual liver transplantation, "Y" type vein from the cross part between vena cava and two iliac of donor and "Y' type prosthesis were employed to recanalize portal vein and the bile duct between dual liver grafts and recipient. The dual right upper lobes about 45-50% of the recipient liver volume were taken as donor, one was orthotopically implanted at its original position, the other was rotated 180° sagitally and heterotopically positioned in the left upper quadrant. Microcirculation parameters, liver function, immunohistochemistry and survival were analyzed to evaluate the function of dual liver grafts. No significant difference in the hepatic microcirculatory flow was found between two grafts in the first 90 minutes after reperfusion. Light and electronic microscope showed the liver architecture was maintained without obvious features of cellular destruction and the continuity of the endothelium was preserved. Only 3 heterotopically positioned graft appeared patchy desquamation of endothelial cell, mitochondrial swelling and hepatocytes cytoplasmic vacuolization. Immunohistochemistry revealed there is no difference in hepatocyte activity and the ability of endothelia to contract and relax after reperfusion between dual grafts. Dual grafts made a rapid amelioration of liver function after reperfusion. 7 rats survived more than 7 days with survival rate of 58.3.%. Using "Y" type vein and bile duct prosthesis, we

  7. Measurement of Thermal Conductivity of Porcine Liver in the Temperature Range of Cryotherapy and Hyperthermia (250~315k) by A Thermal Sensor Made of A Micron-Scale Enameled Copper Wire.

    Science.gov (United States)

    Jiang, Z D; Zhao, G; Lu, G R

      BACKGROUND: Cryotherapy and hyperthermia are effective treatments for several diseases, especially for liver cancers. Thermal conductivity is a significant thermal property for the prediction and guidance of surgical procedure. However, the thermal conductivities of organs and tissues, especially over the temperature range of both cryotherapy and hyperthermia are scarce. To provide comprehensive thermal conductivity of liver for both cryotherapy and hyperthermia. A hot probe made of stain steel needle and micron-sized copper wire is used for measurement. To verify data processing, both the least square method and the Monte Carlo inversion method are used to determine the hot probe constants, respectively, with reference materials of water and 29.9 % Ca 2 Cl aqueous solution. Then the thermal conductivities of Hanks solution and pork liver bathed in Hanks solution are measured. The effective length for two methods is nearly the same, but the heat capacity of probe calibrated by the Monte Carlo inversion is temperature dependent. Fairly comprehensive thermal conductivity of porcine liver measured with these two methods in the target temperature range is verified to be similar. We provide an integrated thermal conductivity of liver for cryotherapy and hyperthermia in two methods, and make more accurate predictions possible for surgery. The least square method and the Monte Carlo inversion method have their advantages and disadvantages. The least square method is available for measurement of liquids that not prone to convection or solids in a wide temperature range, while the Monte Carlo inversion method is available for accurate and rapid measurement.

  8. Mechanical characterization of porcine abdominal organs.

    Science.gov (United States)

    Tamura, Atsutaka; Omori, Kiyoshi; Miki, Kazuo; Lee, Jong B; Yang, King H; King, Albert I

    2002-11-01

    Typical automotive related abdominal injuries occur due to contact with the rim of the steering wheel, seatbelt and armrest, however, the rate is less than in other body regions. When solid abdominal organs, such as the liver, kidneys and spleen are involved, the injury severity tends to be higher. Although sled and pendulum impact tests have been conducted using cadavers and animals, the mechanical properties and the tissue level injury tolerance of abdominal solid organs are not well characterized. These data are needed in the development of computer models, the improvement of current anthropometric test devices and the enhancement of our understanding of abdominal injury mechanisms. In this study, a series of experimental tests on solid abdominal organs was conducted using porcine liver, kidney and spleen specimens. Additionally, the injury tolerance of the solid organs was deduced from the experimental data.

  9. A Liver-centric Multiscale Modeling Framework for Xenobiotics

    Science.gov (United States)

    We describe a multi-scale framework for modeling acetaminophen-induced liver toxicity. Acetaminophen is a widely used analgesic. Overdose of acetaminophen can result in liver injury via its biotransformation into toxic product, which further induce massive necrosis. Our study foc...

  10. A model study on color and related structural properties of cured porcine batters

    NARCIS (Netherlands)

    Palombo, R.

    1990-01-01

    Color, determined by tristimulus colorimeters, and related structural properties, i.e., microstructure, surface rheology, and bulk rheology, of cured porcine meat batters were studied.

    Effects of various processing factors (such as, temperature, air pressure during chopping, and

  11. The rolling-circle melting-pot model for porcine circovirus DNA replication

    Science.gov (United States)

    A stem-loop structure, formed by a pair of inverted repeats during DNA replication, is a conserved feature at the origin of DNA replication (Ori) among plant and animal viruses, bacteriophages and plasmids that replicate their genomes via the rolling-circle replication (RCR) mechanism. Porcine circo...

  12. Assessment of Chronological Effects of Irreversible Electroporation on Hilar Bile Ducts in a Porcine Model

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Woong, E-mail: cooljay@korea.ac.kr; Lu, David S. K., E-mail: dlu@mednet.ucla.edu; Osuagwu, Ferdnand, E-mail: fosuagwu@mednet.ucla.edu; Raman, Steven, E-mail: sraman@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Department of Radiology (United States); Lassman, Charles, E-mail: classman@mednet.ucla.edu [David Geffen School of Medicine at UCLA, Department of Pathology (United States)

    2013-11-07

    PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE. Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position.

  13. Assessment of Chronological Effects of Irreversible Electroporation on Hilar Bile Ducts in a Porcine Model

    International Nuclear Information System (INIS)

    Choi, Jae Woong; Lu, David S. K.; Osuagwu, Ferdnand; Raman, Steven; Lassman, Charles

    2014-01-01

    PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE. Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position

  14. Irreversible Electroporation of the Pancreas Using Parallel Plate Electrodes in a Porcine Model: A Feasibility Study.

    Science.gov (United States)

    Rombouts, Steffi J E; Nijkamp, Maarten W; van Dijck, Willemijn P M; Brosens, Lodewijk A A; Konings, Maurits; van Hillegersberg, R; Borel Rinkes, Inne H M; Hagendoorn, Jeroen; Wittkampf, Fred H; Molenaar, I Quintus

    2017-01-01

    Irreversible electroporation (IRE) with needle electrodes is being explored as treatment option in locally advanced pancreatic cancer. Several studies have shown promising results with IRE needles, positioned around the tumor to achieve tumor ablation. Disadvantages are the technical difficulties for needle placement, the time needed to achieve tumor ablation, the risk of needle track seeding and most important the possible occurrence of postoperative pancreatic fistula via the needle tracks. The aim of this experimental study was to evaluate the feasibility of a new IRE-technique using two parallel plate electrodes, in a porcine model. Twelve healthy pigs underwent laparotomy. The pancreas was mobilized to enable positioning of the paddles. A standard monophasic external cardiac defibrillator was used to perform an ablation in 3 separate parts of the pancreas; either a single application of 50 or 100J or a serial application of 4x50J. After 6 hours, pancreatectomy was performed for histology and pigs were terminated. Histology showed necrosis of pancreatic parenchyma with neutrophil influx in 5/12, 11/12 and 12/12 of the ablated areas at 50, 100, and 4x50J respectively. The electric current density threshold to achieve necrosis was 4.3, 5.1 and 3.4 A/cm2 respectively. The ablation threshold was significantly lower for the serial compared to the single applications (p = 0.003). The content of the ablated areas differed between the applications: areas treated with a single application of 50 J often contained vital areas without obvious necrosis, whereas half of the sections treated with 100 J showed small islands of normal looking cells surrounded by necrosis, while all sections receiving 4x 50 J showed a homogeneous necrotic lesion. Pancreatic tissue can be successfully ablated using two parallel paddles around the tissue. A serial application of 4x50J was most effective in creating a homogeneous necrotic lesion.

  15. Irreversible Electroporation of the Pancreas Using Parallel Plate Electrodes in a Porcine Model: A Feasibility Study.

    Directory of Open Access Journals (Sweden)

    Steffi J E Rombouts

    Full Text Available Irreversible electroporation (IRE with needle electrodes is being explored as treatment option in locally advanced pancreatic cancer. Several studies have shown promising results with IRE needles, positioned around the tumor to achieve tumor ablation. Disadvantages are the technical difficulties for needle placement, the time needed to achieve tumor ablation, the risk of needle track seeding and most important the possible occurrence of postoperative pancreatic fistula via the needle tracks. The aim of this experimental study was to evaluate the feasibility of a new IRE-technique using two parallel plate electrodes, in a porcine model.Twelve healthy pigs underwent laparotomy. The pancreas was mobilized to enable positioning of the paddles. A standard monophasic external cardiac defibrillator was used to perform an ablation in 3 separate parts of the pancreas; either a single application of 50 or 100J or a serial application of 4x50J. After 6 hours, pancreatectomy was performed for histology and pigs were terminated.Histology showed necrosis of pancreatic parenchyma with neutrophil influx in 5/12, 11/12 and 12/12 of the ablated areas at 50, 100, and 4x50J respectively. The electric current density threshold to achieve necrosis was 4.3, 5.1 and 3.4 A/cm2 respectively. The ablation threshold was significantly lower for the serial compared to the single applications (p = 0.003. The content of the ablated areas differed between the applications: areas treated with a single application of 50 J often contained vital areas without obvious necrosis, whereas half of the sections treated with 100 J showed small islands of normal looking cells surrounded by necrosis, while all sections receiving 4x 50 J showed a homogeneous necrotic lesion.Pancreatic tissue can be successfully ablated using two parallel paddles around the tissue. A serial application of 4x50J was most effective in creating a homogeneous necrotic lesion.

  16. Porcine lens nuclei as a model for comparison of 3 ultrasound modalities regarding efficiency and chatter.

    Science.gov (United States)

    Oakey, Zack B; Jensen, Jason D; Zaugg, Brian E; Radmall, Bryce R; Pettey, Jeff H; Olson, Randall J

    2013-08-01

    To validate a porcine lens model by comparing density and ultrasound (US) with known human standards using the Infiniti Ozil with Intelligent Phacoemulsification (torsional), Whitestar Signature Micropulse (longitudinal), and Ellips FX (transversal) modalities. Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. Lens nuclei were formalin soaked in hour-based intervals and divided into 2.0 mm cubes. Density was characterized by crushing experiments and compared with known human measures. Efficiency and chatter were examined. The mean weight to cut thickness in half ranged from 16.9 g ± 5.5 (SD) in the 0-hour group to 121.3 ± 47.5 gm in the 4-hour group. Lenses in the 2-hour group (mean 70.2 ± 19.1 g) best matched human density (P=.215). The mean efficiency ranged from 0.432 ± 0.178 seconds to 9.111 ± 2.925 seconds; chatter ranged from zero to 1.85 ± 1.927 bounces. No significant difference was detected when comparing the 2-hour formalin group with human lenses in torsional and transversal US. There was no significant difference between transversal and torsional modalities, consistent with human studies. Although longitudinal (6 milliseconds on, 12 milliseconds off) was significantly more efficient at 50% power than at 25%, there was no significant difference compared with transversal or torsional US. Animal lenses soaked for 2 hours in formalin were most comparable to human lenses. Longitudinal US may be an acceptable alternative to torsional and transversal US. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  17. Proteomic Profiling in Early Venous Stenosis Formation in a Porcine Model of Hemodialysis Graft

    Science.gov (United States)

    Misra, Sanjay; Fu, Alex A.; Puggioni, Alessandra; Glockner, James F.; McKusick, Michael A.; Bjarnason, Haraldur; Mukhopadhyay, Debabrata

    2009-01-01

    PURPOSE To use proteomic analysis to identify up- and downregulated proteins in early venous stenosis formation in a porcine model of hemodialysis graft failure. MATERIALS AND METHODS Pigs had chronic renal insufficiency created by subtotal renal infarction caused by renal artery embolization. Arteriovenous polytetrafluoroethylene grafts were placed 28 days later and the animals were killed after a further 3 days (n = 4), 7 days (n = 4), or 14 days (n = 4). Proteomic analysis with isotope-coded affinity tags and multidimensional liquid chromatography followed by tandem mass spectrometry was performed on the venous stenosis and control vessels. Expression of proteins was further confirmed by Western blot analysis. The blood urea nitrogen (BUN) and creatinine levels were determined before renal artery embolization and at the time of graft placement. RESULTS At graft placement, mean BUN and creatinine levels were significantly higher than before embolization (P < .05). Six proteins were identified that were common to all four animals at the same time point. Five proteins (α-fetoprotein, fetuin A, macrophage migration inhibitory factor, pyruvate dehydrogenase E1 component, and lactoferrin) were upregulated and one protein (decorin) was downregulated. Expression of macrophage migration inhibitory factor, α-fetoprotein, and lactoferrin was further validated with Western blotting. By day 14, lactoferrin and fetuin-A expression were increased significantly in early venous stenosis formation. CONCLUSIONS Significantly increased expression of lactoferrin and fetuin-A were observed in early venous stenosis by day 14. Understanding the role of lactoferrin and fetuin-A in hemodialysis vascular access failure could help in improving outcomes in patients undergoing hemodialysis. PMID:19028119

  18. Evaluation of functionality and biological response of the multilayer flow modulator in porcine animal models.

    Science.gov (United States)

    Sultan, Sherif; Kavanagh, Edel P; Hynes, Niamh; Diethrich, Edward B

    2016-02-01

    This study outlines the use of non-aneurysmal porcine animal models to study device functionality and biological response of the Multilayer Flow Modulator (MFM) (Cardiatis, Isnes, Belgium), with an emphasis on preclinical device functionality and biological response characteristics in an otherwise healthy aorta. Twelve animals were implanted with the study device in the abdominal aorta, in 6 animals for 1 month and 6 animals for 6 months. Upon completion of the study period, each animal underwent a necropsy to examine how the implanted device had affected the artery and surrounding tissue. Neointima and stenosis formation were recorded via morphometry, and endothelialization via histopathological analysis. The MFM devices were delivered to their respective implantation sites without difficulty. Six of the implanted stents were oversized with percentages ranging from 2.6% to 18.8%. Statistical analysis was carried out and showed no significance between the regular sized stent group and oversized stent group for neointimal area (P=0.17), neointimal thickness (P=0.17), and percentage area stenosis (P=0.65). Histopathological findings showed in most areas flattened endothelium like cells lined the luminal surface of the neointima. Scanning electron microscopy also showed the devices were well tolerated, inciting only a minimal neointimal covering and little fibrin or platelet deposition. Neointimal thickness of 239.7±55.6 μm and 318.3±130.4 μm, and percentage area stenosis of 9.6±2.6% and 12.6±5% were recorded at 1 and 6 months respectively. No statistical differences were found between these results. The MFM devices were delivered to their respective implantation sites without difficulty and incited little neointimal and stenosis formation in the aorta, affirming its functionality and biocompatibility.

  19. Noninvasive treatment of deep venous thrombosis using pulsed ultrasound cavitation therapy (histotripsy) in a porcine model.

    Science.gov (United States)

    Maxwell, Adam D; Owens, Gabe; Gurm, Hitinder S; Ives, Kimberly; Myers, Daniel D; Xu, Zhen

    2011-03-01

    This study evaluated histotripsy as a noninvasive, image-guided method of thrombolysis in a porcine model of deep vein thrombosis. Histotripsy therapy uses short, high-intensity, focused ultrasound pulses to cause mechanical breakdown of targeted soft tissue by acoustic cavitation, which is guided by real-time ultrasound imaging. This is an in vivo feasibility study of histotripsy thrombolysis. Acute thrombi were formed in the femoral vein of juvenile pigs weighing 30-40 kg by balloon occlusion with two catheters and thrombin infusion. A 10-cm-diameter 1-MHz focused transducer was used for therapy. An 8-MHz ultrasound imager was used to align the clot with the therapy focus. Therapy consisted of five cycle pulses delivered at a rate of 1 kHz and peak negative pressure between 14 and 19 MPa. The focus was scanned along the long axis of the vessel to treat the entire visible clot during ultrasound exposure. The targeted region identified by a hyperechoic cavitation bubble cloud was visualized via ultrasound during treatment. Thrombus breakdown was apparent as a decrease in echogenicity within the vessel in 10 of 12 cases and in 7 cases improved flow through the vein as measured by color Doppler. Vessel histology found denudation of vascular endothelium and small pockets of hemorrhage in the vessel adventitia and underlying muscle and fatty tissue, but perforation of the vessel wall was never observed. The results indicate histotripsy has potential for development as a noninvasive treatment for deep vein thrombosis. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  20. Research advances in animal models of nonalcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    HUANG Haiyan

    2014-09-01

    Full Text Available In recent years, the incidence of nonalcoholic fatty liver disease (NAFLD has increased gradually along with the rising prevalence of obesity, type 2 diabetes, and hyperlipidemia, and NAFLD has become one of the most common chronic liver diseases in the world and the second major liver disease after chronic viral hepatitis in China. However, its pathogenesis has not yet been clarified. Animal models are playing an important role in researches on NAFLD due to the facts that the development and progression of NAFLD require a long period of time, and ethical limitations exist in conducting drug trials in patients or collecting liver tissues from patients. The animal models with histopathology similar to that of NAFLD patients are reviewed, and their modeling principle, as well as the advantages and disadvantages, are compared. Animal models provide a powerful tool for further studies of NAFLD pathogenesis and drug screening for prevention and treatment of NAFLD.

  1. Comparison of Acute Thrombogenicity for Metallic and Polymeric Bioabsorbable Scaffolds: Magmaris Versus Absorb in a Porcine Arteriovenous Shunt Model.

    Science.gov (United States)

    Waksman, Ron; Lipinski, Michael J; Acampado, Eduardo; Cheng, Qi; Adams, Lila; Torii, Sho; Gai, Jiaxiang; Torguson, Rebecca; Hellinga, David M; Westman, Peter C; Joner, Michael; Zumstein, Philine; Kolodgie, Frank D; Virmani, Renu

    2017-08-01

    A comparison in acute thrombogenicity between the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold and the Absorb bioresorbable vascular scaffold has not been performed. This study assessed acute thrombogenicity of Magmaris compared with Absorb and the Orsiro hybrid drug-eluting stent in a porcine arteriovenous shunt model. An ex vivo porcine carotid jugular arteriovenous shunt was established and connected to SYLGARD tubing containing the Magmaris, Absorb, and Orsiro scaffolds/stents and allowed to run in the shunt for a maximum of 1 hour. Twelve shunts (2 shunt runs per pig) were run comparing the 3 scaffolds in alternating order. Nested generalized linear mixed models were used to compare variables between scaffold groups while adjusting for variability between shunt runs. Confocal fluorescent microscopy costaining CD61/CD42b demonstrated that both Magmaris (3.0%) and Orsiro (4.6%) had less platelet coverage of the total scaffold compared with Absorb (21.8%). Scanning electron microscopy demonstrated significantly less thrombus deposition to Magmaris as a percentage of the total scaffold compared with Absorb (5.0% versus 16.1%, P =0.02). Magmaris had significantly less PM-1-positive neutrophil and CD14-positive monocyte adherence compared with both Orsiro and Absorb. Orsiro had significantly less monocyte deposition compared with Absorb. Despite a similar scaffold strut thickness, the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold was significantly less thrombogenic compared with the Absorb bioresorbable vascular scaffold in an ex vivo porcine arteriovenous shunt model. Further studies are needed to determine whether the reduced thrombogenicity of Magmaris will result in reductions in major cardiovascular events. © 2017 American Heart Association, Inc.

  2. A porcine model of bladder outlet obstruction incorporating radio-telemetered cystometry.

    Science.gov (United States)

    Shaw, Matthew B; Herndon, Claude D; Cain, Mark P; Rink, Richard C; Kaefer, Martin

    2007-07-01

    To present a novel porcine model of bladder outlet obstruction (BOO) with a standardized bladder outlet resistance and real-time ambulatory radio-telemetered cystometry, as BOO is a common condition with many causes in both adults and children, with significant morbidity and occasional mortality, but attempts to model this condition in many animal models have the fundamental problem of standardising the degree of outlet resistance. BOO was created in nine castrated male pigs by dividing the mid-urethra; outflow was allowed through an implanted bladder drainage catheter containing a resistance valve, allowing urine to flow across the valve only when a set pressure differential was generated across the valve. An implantable radio-telemetered pressure sensor monitored the pressure within the bladder and abdominal cavity, and relayed this information to a remote computer. Four control pigs had an occluded bladder drainage catheter and pressure sensor placed, but were allowed to void normally through the native urethra. Intra-vesical pressure was monitored by telemetry, while the resistance valve was increased weekly, beginning with 2 cmH2O and ultimately reaching 10 cmH2O. The pigs were assessed using conventional cystometry under anaesthesia before death, and samples conserved in formalin for haematoxylin and eosin staining. The pigs had radio-telemetered cystometry for a median of 26 days. All telemetry implants functioned well for the duration of the experiment, but one pig developed a urethral fistula and was excluded from the study. With BOO the bladder mass index (bladder mass/body mass x 10 000) increased from 9.7 to 20 (P = 0.004), with a significant degree of hypertrophy of the detrusor smooth muscle bundles. Obstructed bladders were significantly less compliant than control bladders (8.3 vs 22.1 mL/cmH2O, P = 0.03). Telemetric cystometry showed that there was no statistically significance difference in mean bladder pressure between obstructed and control pigs

  3. The genetic regulation of the terminating phase of liver regeneration

    DEFF Research Database (Denmark)

    Nygård, Ingvild E.; Mortensen, Kim E.; Hedegaard, Jakob

    2012-01-01

    Background After partial hepatectomy (PHx), the liver regeneration process terminates when the normal liver-mass/body-weight ratio of 2.5% has been re-established. To investigate the genetic regulation of the terminating phase of liver regeneration, we performed a 60% PHx in a porcine model. Liver...... biopsies were taken at the time of resection, after three weeks and upon termination the sixth week. Gene expression profiles were obtained using porcine oligonucleotide microarrays. Our study reveals the interactions between genes regulating the cell cycle, apoptosis and angiogenesis, and the role...... of Transforming Growth Factor-β (TGF-β) signalling towards the end of liver regeneration. Results Microarray analysis revealed a dominance of genes regulating apoptosis towards the end of regeneration. Caspase Recruitment Domain-Containing Protein 11 (CARD11) was up-regulated six weeks after PHx, suggesting...

  4. Experimental models of hepatotoxicity related to acute liver failure

    Energy Technology Data Exchange (ETDEWEB)

    Maes, Michaël [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Vinken, Mathieu, E-mail: mvinken@vub.ac.be [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Jaeschke, Hartmut [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City (United States)

    2016-01-01

    Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposure or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure. - Highlights: • The murine APAP model is very close to what is observed in patients. • The Gal/ET model is useful to study TNFα-mediated apoptotic signaling mechanisms. • Fas receptor activation is an effective model of apoptosis and secondary necrosis. • The ConA model is a relevant model of auto-immune hepatitis and viral hepatitis. • Multiple time point evaluation needed in experimental models of acute liver injury.

  5. Selective Retrograde Venous Revascularization of the Myocardium when PCI or CABG Is Impossible: Investigation in a Porcine Model

    DEFF Research Database (Denmark)

    Møller, Christian H; Nørgaard, Martin A; Gøtze, Jens P

    2008-01-01

    We investigated the possibility of nourishing the myocardium through selective retrograde coronary venous bypass grafting (CVBG) with an off-pump technique and evaluated various methods of monitoring the physiological effects of this procedure. In a porcine model, the left internal mammary artery...... tension decreased, but with time some recovery was seen. Cardiac troponin T was elevated. Histological analysis showed ischemic changes. In control pigs, microdialysis was performed for 1.5 hours up to LAD artery ligation, after which all pigs died in ventricular fibrillation arrest. No increase...

  6. Melatonin Does Not Affect Oxidative/Inflammatory Biomarkers in a Closed-Chest Porcine Model of Acute Myocardial Infarction

    DEFF Research Database (Denmark)

    Halladin, Natalie L.; Ekelof, Sarah; Jensen, Svend Eggert

    2014-01-01

    Aim: To test whether melatonin reduces oxidative and inflammatory biomarkers in a closed-chest porcine model of acute myocardial infarction. Materials and Methods: Twenty pigs were randomized to receive a total dosage of 200 mg (0.4 mg/ml) of melatonin, or placebo immediately prior to reperfusion....... There was an increase in hs-TnT, but no significant difference between the melatonin-treated and placebo-treated groups. There were no significant differences in development of any of the circulating plasma markers between the two groups. Conclusion: Melatonin treatment did not result in reduction of inflammatory...

  7. Beneficial antimicrobial effect of the addition of an aminoglycoside to a β-lactam antibiotic in an E. coli porcine intensive care severe sepsis model.

    Science.gov (United States)

    Skorup, Paul; Maudsdotter, Lisa; Lipcsey, Miklós; Castegren, Markus; Larsson, Anders; Jonsson, Ann-Beth; Sjölin, Jan

    2014-01-01

    This study aimed to determine whether the addition of an aminoglycoside to a ß-lactam antibiotic increases the antimicrobial effect during the early phase of Gram-negative severe sepsis/septic shock. A porcine model was selected that considered each animal's individual blood bactericidal capacity. Escherichia coli, susceptible to both antibiotics, was given to healthy pigs intravenously during 3 h. At 2 h, the animals were randomized to a 20-min infusion with either cefuroxime alone (n = 9), a combination of cefuroxime+tobramycin (n = 9), or saline (control, n = 9). Blood samples were collected hourly for cultures and quantitative polymerase chain reaction (PCR). Bacterial growth in the organs after 6 h was chosen as the primary endpoint. A blood sample was obtained at baseline before start of bacterial infusion for ex vivo investigation of the blood bactericidal capacity. At 1 h after the administration of the antibiotics, a second blood sample was taken for ex vivo investigation of the antibiotic-induced blood killing activity. All animals developed severe sepsis/septic shock. Blood cultures and PCR rapidly became negative after completed bacterial infusion. Antibiotic-induced blood killing activity was significantly greater in the combination group than in the cefuroxime group (pantibiotic groups compared with the controls (pantibiotic groups. Bacterial growth in the liver was significantly less in the combination group than in the cefuroxime group (pantibiotic-induced blood killing activity and less bacteria in the liver than cefuroxime alone. Individual blood bactericidal capacity may have a significant effect on antimicrobial outcome.

  8. Protective effect of active perfusion in porcine models of acute myocardial ischemia

    Science.gov (United States)

    Feng, Zanxiang; Mao, Zhifu; Dong, Shengjun; Liu, Baohui

    2016-01-01

    Mortality rates associated with off-pump coronary artery bypass (CAB) are relatively high, as the majority of patients requiring CAB are at a high risk for cardiac events. The present study aimed to establish porcine models of acute myocardial ischemia, and evaluate the protective role of shunt and active perfusion. A total of 30 pigs were randomly assigned to five groups, as follows: i) Sham (control); ii) A1 (shunt; stenosis rate, 55%); iii) A2 (shunt; stenosis rate, 75%); iv) B1 (active perfusion; stenosis rate, 55%); and v) B2 (active perfusion; stenosis rate, 75%) groups. Aortic pressure (P0), left anterior descending coronary pressure (P1), and coronary effective perfusion pressure (P1/P0) were measured. The expression levels of tumor necrosis factor-α (TNF-α), cardiac troponin (cTnI), creatine kinase-myocardial band (CK-MB), interleukin (IL)-6, IL-10, B-cell lymphoma 2 (Bcl-2), and caspase-3 were detected using enzyme-linked immunosorbent assay or western blotting. The myocardial apoptosis rate was determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Ischemia models with stenosis rates of 55 and 75% were successfully constructed following suturing of the descending artery. Compared with the control, the 55 and 75% stenosis groups demonstrated significantly decreased P1/P0, increased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, an increased rate of myocardial apoptosis, and a decreased expression level of anti-apoptotic protein, Bcl-2. At 30 min following successful establishment of the model (ST segment elevation to 1 mm), group B demonstrated significantly increased P1/P0, decreased expression levels of TNF-α, cTnI, CK-MB, IL-6, IL-10 and caspase-3, a decreased rate of myocardial apoptosis, and an increased expression level of anti-apoptotic protein, Bcl-2. Furthermore, the current study indicated that active perfusion was more efficacious in maintaining myocardial perfusion and alleviating

  9. Sustained analgesic effect of clonidine co-polymer depot in a porcine incisional pain model

    Directory of Open Access Journals (Sweden)

    Wilsey JT

    2018-04-01

    viable nonopioid, nonamide anesthetic therapy for the treatment of acute postsurgical nociceptive sensitization. Keywords: amide anesthetic, bio-erodible polymer, peripherally acting analgesic, imidazoline, porcine model, postoperative pain, regional anesthesia, sustained release

  10. Generating a normalized geometric liver model with warping

    International Nuclear Information System (INIS)

    Boes, J.L.; Weymouth, T.E.; Meyer, C.R.; Quint, L.E.; Bland, P.H.; Bookstein, F.L.

    1990-01-01

    This paper reports on the automated determination of the liver surface in abdominal CT scans for radiation treatment, surgery planning, and anatomic visualization. The normalized geometric model of the liver is generated by averaging registered outlines from a set of 15 studies of normal liver. The outlines have been registered with the use of thin-plate spline warping based on a set of five homologous landmarks. Thus, the model consists of an average of the surface and a set of five anatomic landmarks. The accuracy of the model is measured against both the set of studies used in model generation and an alternate set of 15 normal studies with use of, as an error measure, the ratio of nonoverlapping model and study volume to total model volume

  11. Evaluation of adenosine preconditioning with 99mTc-His10-annexin V in a porcine model of myocardium ischemia and reperfusion injury: preliminary study

    International Nuclear Information System (INIS)

    Ye Fei; Fang Wei; Wang Feng; Hua Zichun; Wang Zizheng; Yang Xiang

    2011-01-01

    Purpose: The goal of this study was to evaluate the feasibility of 99m Tc-His 10 -annexin V for the detection of acute myocardial cell death and to assess the effect of adenosine preconditioning in a porcine model of myocardium ischemia and reperfusion injury (RI). Materials and Methods: 99m Tc-His 10 -annexin V was prepared by one-step direct labeling, and RCP and radiostability were tested. The binding of 99m Tc-His 10 -annexin V to apoptosis was validated in vitro using camptothecin-induced Jurkat cells. In vivo biodistribution was determined in mice by the dissection method. Ischemia of 20-30 min was induced by balloon occlusion of the epicardial coronary artery of the porcine model (n=14). Adenosine was infused intravenously in six pigs before coronary occlusion. 99m Tc-His 10 -annexin V (n=12) was injected intravenously at 1 h after reperfusion. SPECT/CT was acquired at 3 h postinjection. Myocardial perfusion imaging (MPI) with 99m Tc-MIBI was also performed 1 day after His 10 -annexin V imaging. Cardiac tissues were analyzed postmortem using hematoxylin-and-eosin and TUNEL staining. Caspase-3 activity was measured to confirm the presence of apoptosis. Results: 99m Tc-His 10 -annexin V had a RCP >98% and high stability 2 h after radiolabeling; it could bind to apoptotic cells with high affinity. Biodistribution of 99m Tc-His 10 -annexin V showed a predominant uptake in the kidney and relatively low uptake in the myocardium, liver and gastrointestinal tract; rapid clearance from blood and kidney was observed. In the untreated group, intense uptake of His 10 -annexin V was visualized in the defect which was shown in MPI, whereas in the adenosine group a mild uptake of 99m Tc-His 10 -annexin was found in the risk area which showed no defects in the 99m Tc-MIBI image. TUNEL staining and activated caspase-3 confirmed the ongoing apoptosis in RI. Adenosine preconditioning significantly diminished the level of apoptosis. Uptake of His 10 -annexin V in RI correlated

  12. Dermal absorption behavior of fluorescent molecules in nanoparticles on human and porcine skin models.

    Science.gov (United States)

    Debotton, Nir; Badihi, Amit; Robinpour, Mano; Enk, Claes D; Benita, Simon

    2017-05-30

    The percutaneous passage of poorly skin absorbed molecules can be improved using nanocarriers, particularly biodegradable polymeric nanospheres (NSs) or nanocapsules (NCs). However, penetration of the encapsulated molecules may be affected by other factors than the nanocarrier properties. To gain insight information on the skin absorption of two fluorescent cargos, DiIC 18 (5) and coumarin-6 were incorporated in NSs or NCs and topically applied on various human and porcine skin samples. 3D imaging techniques suggest that NSs and NCs enhanced deep dermal penetration of both probes similarly, when applied on excised human skin irrespective of the nature of the cargo. However, when ex vivo pig skin was utilized, the cutaneous absorption of DiIC 18 (5) was more pronounced by means of PLGA NCs than NSs. In contrast, PLGA NSs noticeably improved the porcine skin penetration of coumarin-6, as compared to the NCs. Furthermore, the porcine skin results were reproducible when triplicated whereas from various human skin samples, as expected, the results were not sufficiently reproducible and large deviations were observed. The overall findings from this comprehensive comparison emphasize the potential of PLGA NCs or NSs to promote cutaneous bioavailability of encapsulated drugs, exhibiting different physicochemical properties but depending on the nature of the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model

    Science.gov (United States)

    Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

    2014-01-01

    Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first

  14. Scabies mites alter the skin microbiome and promote growth of opportunistic pathogens in a porcine model.

    Directory of Open Access Journals (Sweden)

    Pearl M Swe

    Full Text Available BACKGROUND: The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. METHODOLOGY/PRINCIPAL FINDINGS: In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. CONCLUSIONS

  15. Repeated subretinal surgery and removal of subretinal decalin is well tolerated - evidence from a porcine model.

    Science.gov (United States)

    Sørensen, Nina Buus; Klemp, Kristian; Kjær, Troels Wesenberg; Heegaard, Steffen; la Cour, Morten; Kiilgaard, Jens Folke

    2017-09-01

    Subretinal perfluorocarbon liquid (PFCL) is a serious complication that can occur after retinal detachment repair. It is possible to remove the PFCL surgically, but retinal damage related to the procedure is unknown. Also, increasing interest in subretinal treatment makes it relevant to examine the functional and morphological consequences of repeated subretinal manipulation. We hypothesized that PFCL in a porcine model can be injected in the subretinal space and removed with minimal effect on retinal structure and function. The left eyes of ten healthy three-month-old female domestic pigs were included. Multifocal electroretinograms (mfERG) were recorded before surgery. Following vitrectomy, a PFCL bleb (decalin) was injected subretinally using a 41G cannula. After 14 days the decalin was removed through a 41G cannula in combination with a 2 ml syringe and an intermediate flexible tube. Two weeks after removal, a control mfERG was recorded, the pigs were enucleated and sacrificed and eyes were examined histologically. All statistics were carried out with a paired t-test in SAS Enterprise Guide 7.1® (SAS Institute Inc., Cary, NC, USA). There was no significant difference in mfERG amplitude ratio (left/right eye) between baseline and recordings two weeks after removal of decalin (P1 (M = 0.26, SD = 0.80, p = 0.39), second order kernel (M = -0.18, SD = 0.86, p = 0.57), Direct Response (M = 0.39, SD = 0.61, p = 0.12) or Induced Component (M = -0.03, SD = 0.40, p = 0.80)). Histologically, the photoreceptor outer segments were minimally affected. Otherwise the retina was normal 14 days after removal of decalin. In four pigs the subretinal decalin displaced inferiorly and was no longer accessible for removal. Subretinal decalin can be removed within 14 days without lasting retinal damage. Decalin is a heavy liquid where the risk of displacement is high. Future studies using PFCLs to control duration of an experimental retinal separation

  16. Reliable porcine coronary model of chronic total occlusion using copper wire stents and bioabsorbable levo-polylactic acid polymer.

    Science.gov (United States)

    Sim, Doo Sun; Jeong, Myung Ho; Cha, Kyoung Rae; Park, Suk Ho; Park, Jong Oh; Shin, Young Min; Shin, Heungsoo; Hong, Young Joon; Ahn, Youngkeun; Schwartz, Robert S; Kang, Jung Chaee

    2012-12-01

    Chronic total occlusion (CTO) remains a challenge in interventional cardiology. We investigated the feasibility and reliability of copper wire stents and levo-polylactic acid (l-PLA) as a means of CTO induction in a porcine model. In one group of 20 swine, copper stents were crimped on a 3.0mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD). In the other group of 20 swine, l-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0mm balloon catheter to induce embolization. Of 20 swine which underwent copper stent implantation, 13 died of stent thrombosis. In the remaining 7 swine, total or near total occlusion with collateral circulation was observed at 5 weeks. Of 20 swine which underwent l-PLA embolization, 4 died of ventricular fibrillation during or shortly after the procedure. Serial histopathologic studies showed complete absorption of the polymer with replacement by fibrotic tissue approximately 4 weeks following the polymer implantation. CTO could be reliably induced in porcine coronary arteries by copper stents and l-PLA. These models may support investigation of new percutaneous devices to facilitate CTO interventions. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  17. Second-generation magnesium scaffold Magmaris: device design and preclinical evaluation in a porcine coronary artery model.

    Science.gov (United States)

    Waksman, Ron; Zumstein, Philine; Pritsch, Martin; Wittchow, Eric; Haude, Michael; Lapointe-Corriveau, Capucine; Leclerc, Guy; Joner, Michael

    2017-07-20

    The second-generation drug-eluting absorbable magnesium scaffold Magmaris, recently introduced for the treatment of obstructive coronary atherosclerotic lesions, suggests a good safety profile, but preclinical assessment is important for predicting clinical performance. The aim of the present study was to assess subacute and long-term safety as well as pharmacokinetic properties of the Magmaris compared with a current-generation metallic DES and an approved BRS in porcine and rabbit animal models. Ninety Magmaris scaffolds were implanted into non-diseased porcine and rabbit models. A bioresorbable vascular scaffold (Absorb) and a permanent drug-eluting stent (XIENCE Xpedition) served as controls. Scanning electron microscopy showed increased endothelialisation and decreased thrombus formation at three and 28 days in the Magmaris group compared with the Absorb group. In the XIENCE group, inflammation exceeded the level in the Magmaris group at 365 and 730 days. Neointimal growth was greater in the Magmaris group than in the XIENCE group. Late lumen loss decreased over time in both groups. Optical coherence tomography (OCT) showed stable luminal dimensions in both the Magmaris and XIENCE groups. Pharmacokinetic studies demonstrated a retarded elution profile in the Magmaris group with 69.4% of sirolimus released at 90 days. Preclinical results suggest that the Magmaris has a favourable safety profile with advanced healing relative to benchmark, low acute thrombogenicity, and absence of excessive lumen loss up to two years. These results support clinical application of Magmaris for human use.

  18. A retinaculum-sparing surgical approach preserves porcine stifle joint cartilage in an experimental animal model of cartilage repair.

    Science.gov (United States)

    Bonadio, Marcelo B; Friedman, James M; Sennett, Mackenzie L; Mauck, Robert L; Dodge, George R; Madry, Henning

    2017-12-01

    This study compares a traditional parapatellar retinaculum-sacrificing arthrotomy to a retinaculum-sparing arthrotomy in a porcine stifle joint as a cartilage repair model. Surgical exposure of the femoral trochlea of ten Yucatan pigs stifle joint was performed using either a traditional medial parapatellar approach with retinaculum incision and luxation of the patella (n = 5) or a minimally invasive (MIS) approach which spared the patellar retinaculum (n = 5). Both classical and MIS approaches provided adequate access to the trochlea, enabling the creation of cartilage defects without difficulties. Four full thickness, 4 mm circular full-thickness cartilage defects were created in each trochlea. There were no intraoperative complications observed in either surgical approach. All pigs were allowed full weight-bearing and full range of motion immediately postoperatively and were euthanized between 2 and 3 weeks. The traditional approach was associated with increased cartilage wear compared to the MIS approach. Two blinded raters performed gross evaluation of the trochlea cartilage surrounding the defects according to the modified ICRS cartilage injury classification. The traditional approach cartilage received a significantly worse score than the MIS approach group from both scorers (3.2 vs 0.8, p = 0.01 and 2.8 vs 0, p = 0.005 respectively). The MIS approach results in less damage to the trochlear cartilage and faster return to load bearing activities. As an arthrotomy approach in the porcine model, MIS is superior to the traditional approach.

  19. Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

    Science.gov (United States)

    Kuijk, Ewart W.; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M.; Cuppen, Edwin

    2016-01-01

    The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as cystic organoids, were characterized by high expression of the stem cell marker Lgr5, by the expression of liver progenitor and duct markers, and by low expression of hepatocyte markers, oval cell markers, and stellate cell markers. Prolonged cultures of rat liver organoids depended on high levels of WNT-signalling and the inhibition of BMP-signaling. Upon transplantation of clonal lines to a Fah−/− Il2rg−/− rat model of liver failure, the rat liver stem cells engrafted into the host liver where they differentiated into areas with FAH and Albumin positive hepatocytes. Rat liver stem cell lines hold potential as consistent reliable cell sources for pharmacological, toxicological or metabolic studies. In addition, rat liver stem cell lines may contribute to the development of regenerative medicine in liver disease. To our knowledge, the here described liver stem cell lines represent the first organoid culture system in the rat. PMID:26915950

  20. Similarities in the immunoglobulin response and VH gene usage in rhesus monkeys and humans exposed to porcine hepatocytes

    Directory of Open Access Journals (Sweden)

    Borie Dominic C

    2006-03-01

    Full Text Available Abstract Background The use of porcine cells and organs as a source of xenografts for human patients would vastly increase the donor pool; however, both humans and Old World primates vigorously reject pig tissues due to xenoantibodies that react with the polysaccharide galactose α (1,3 galactose (αGal present on the surface of many porcine cells. We previously examined the xenoantibody response in patients exposed to porcine hepatocytes via treatment(s with bioartficial liver devices (BALs, composed of porcine cells in a support matrix. We determined that xenoantibodies in BAL-treated patients are predominantly directed at porcine αGal carbohydrate epitopes, and are encoded by a small number of germline heavy chain variable region (VH immunoglobulin genes. The studies described in this manuscript were designed to identify whether the xenoantibody responses and the IgVH genes encoding antibodies to porcine hepatocytes in non-human primates used as preclinical models are similar to those in humans. Adult non-immunosuppressed rhesus monkeys (Macaca mulatta were injected intra-portally with porcine hepatocytes or heterotopically transplanted with a porcine liver lobe. Peripheral blood leukocytes and serum were obtained prior to and at multiple time points after exposure, and the immune response was characterized, using ELISA to evaluate the levels and specificities of circulating xenoantibodies, and the production of cDNA libraries to determine the genes used by B cells to encode those antibodies. Results Xenoantibodies produced following exposure to isolated hepatocytes and solid organ liver grafts were predominantly encoded by genes in the VH3 family, with a minor contribution from the VH4 family. Immunoglobulin heavy-chain gene (VH cDNA library screening and gene sequencing of IgM libraries identified the genes as most closely-related to the IGHV3-11 and IGHV4-59 germline progenitors. One of the genes most similar to IGHV3-11, VH3-11cyno, has

  1. A novel porcine model of implant associated osteomyelitis: a comprehensive analysis of local, regional and systemic response

    DEFF Research Database (Denmark)

    Jensen, Louise Kruse; Koch, Janne; Dich-Jorgensen, Kirstine

    2017-01-01

    Pigs are favorable experimental animals for infectious diseases in humans. However, implant associated osteomyelitis (IAO) models in pigs have only been evaluated using high-inoculum infection (>108 CFU) models in 1975 and 1993. Therefore, the aim of this paper was to present a new low inoculum...... porcine model of human IAO based on 42 experimental pigs. The model was created by drilling an implant cavity in the tibial bone followed by insertion of a small steel implant and simultaneous inoculation of Staphylococcus aureus bacteria (n = 32) or saline (n = 10). The infected pigs were either...... inoculated with 104 CFU (n = 26) or 102 and 103 CFU (n = 6). All animals were euthanized five days after insertion of implants. Pigs receiving the high-inoculum infections showed a significantly higher volume of bone lesion, number of neutrophils around the implant, concentrations of acute phase proteins...

  2. Liver

    International Nuclear Information System (INIS)

    Bernardino, M.E.; Sones, P.J. Jr.; Barton Price, R.; Berkman, W.A.

    1984-01-01

    Evaluation of the liver for focal lesions is extremely important because the liver is one of the most common sites for metastatic disease. Most patients with metastatic deposits to the liver have a survival rate of about 6 months. Thus, metastatic disease to the liver has an extremely grave prognosis. In the past patients with hepatic lesions had no therapeutic recourse. However, with recent aggressive surgical advances (such as partial hepatectomies) and hepatic artery embolization, survival of patients with hepatic metastases has increased. Thus it is important for noninvasive imaging not only to detect lesions early in their course, but also to give their true hepatic involvement and the extent of the neoplastic process elsewhere in the body. Recent advances in imaging have been rapidly changing over the past 5 years. These changes have been more rapid in computed tomography (CT) and ultrasound than in radionuclide imaging. Thus, the question addressed in this chapter is: What is the relationship of hepatic ultrasound to the other current diagnostic modalities in detecting metastatic liver disease and other focal liver lesions? Also, what is its possible future relationship to nuclear magnetic resonance?

  3. Clinical and pathological outcomes after irreversible electroporation of the pancreas using two parallel plate electrodes: a porcine model.

    Science.gov (United States)

    Rombouts, Steffi J E; van Dijck, Willemijn P M; Nijkamp, Maarten W; Derksen, Tyche C; Brosens, Lodewijk A A; Hoogwater, Frederik J H; van Leeuwen, Maarten S; Borel Rinkes, Inne H M; van Hillegersberg, Richard; Wittkampf, Fred H; Molenaar, Izaak Q

    2017-12-01

    Irreversible electroporation (IRE) by inserting needles around the tumor as treatment for locally advanced pancreatic cancer entails several disadvantages, such as incomplete ablation due to field inhomogeneity, technical difficulties in needle placement and a risk of pancreatic fistula development. This experimental study evaluates outcomes of IRE using paddles in a porcine model. Six healthy pigs underwent laparotomy and were treated with 2 separate ablations (in head and tail of the pancreas). Follow-up consisted of clinical and laboratory parameters and contrast-enhanced computed tomography (ceCT) imaging. After 2 weeks, pancreatoduodenectomy was performed for histology and the pigs were terminated. All animals survived 14 days. None of the animals developed signs of infection or significant abdominal distention. Serum amylase and lipase peaked at day 1 postoperatively in all pigs, but normalized without signs of pancreatitis. On ceCT-imaging the ablation zone was visible as an ill-defined, hypodense lesion. No abscesses, cysts or ascites were seen. Histology showed a homogenous fibrotic lesion in all pigs. IRE ablation of healthy porcine pancreatic tissue using two plate electrodes is feasible and safe and creates a homogeneous fibrotic lesion. IRE-paddles should be tested on pancreatic adenocarcinoma to determine the effect in cancer tissue. Copyright © 2017. Published by Elsevier Ltd.

  4. 3D thoracoscopic ultrasound volume measurement validation in an ex vivo and in vivo porcine model of lung tumours

    International Nuclear Information System (INIS)

    Hornblower, V D M; Yu, E; Fenster, A; Battista, J J; Malthaner, R A

    2007-01-01

    The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial 'tumours' were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the 'tumours' were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ultrasound images and a manual-radial segmentation technique and these were compared with the known volumes of the agar. In vitro measurements had average accuracy and precision of 4.76% and 1.77%, respectively; in vivo measurements had average accuracy and precision of 8.18% and 1.75%, respectively. The 3D thoracoscopic ultrasound can be used to accurately and reproducibly measure 'tumour' volumes both in vivo and ex vivo

  5. 3D thoracoscopic ultrasound volume measurement validation in an ex vivo and in vivo porcine model of lung tumours

    Energy Technology Data Exchange (ETDEWEB)

    Hornblower, V D M [Canadian Surgical Technologies and Advanced Robotics, London, Ontario (Canada); Yu, E [Canadian Surgical Technologies and Advanced Robotics, London, Ontario (Canada); Fenster, A [Canadian Surgical Technologies and Advanced Robotics, London, Ontario (Canada); Battista, J J [Canadian Surgical Technologies and Advanced Robotics, London, Ontario (Canada); Malthaner, R A [Canadian Surgical Technologies and Advanced Robotics, London, Ontario (Canada)

    2007-01-07

    The purpose of this study was to validate the accuracy and reliability of volume measurements obtained using three-dimensional (3D) thoracoscopic ultrasound (US) imaging. Artificial 'tumours' were created by injecting a liquid agar mixture into spherical moulds of known volume. Once solidified, the 'tumours' were implanted into the lung tissue in both a porcine lung sample ex vivo and a surgical porcine model in vivo. 3D US images were created by mechanically rotating the thoracoscopic ultrasound probe about its long axis while the transducer was maintained in close contact with the tissue. Volume measurements were made by one observer using the ultrasound images and a manual-radial segmentation technique and these were compared with the known volumes of the agar. In vitro measurements had average accuracy and precision of 4.76% and 1.77%, respectively; in vivo measurements had average accuracy and precision of 8.18% and 1.75%, respectively. The 3D thoracoscopic ultrasound can be used to accurately and reproducibly measure 'tumour' volumes both in vivo and ex vivo.

  6. New Insights from Rodent Models of Fatty Liver Disease

    Science.gov (United States)

    2011-01-01

    Abstract Rodent models of fatty liver disease are essential research tools that provide a window into disease pathogenesis and a testing ground for prevention and treatment. Models come in many varieties involving dietary and genetic manipulations, and sometimes both. High-energy diets that induce obesity do not uniformly cause fatty liver disease; this has prompted close scrutiny of specific macronutrients and nutrient combinations to determine which have the greatest potential for hepatotoxicity. At the same time, diets that do not cause obesity or the metabolic syndrome but do cause severe steatohepatitis have been exploited to study factors important to progressive liver injury, including cell death, oxidative stress, and immune activation. Rodents with a genetic predisposition to overeating offer yet another model in which to explore the evolution of fatty liver disease. In some animals that overeat, steatohepatitis can develop even without resorting to a high-energy diet. Importantly, these models and others have been used to document that aerobic exercise can prevent or reduce fatty liver disease. This review focuses primarily on lessons learned about steatohepatitis from manipulations of diet and eating behavior. Numerous additional insights about hepatic lipid metabolism, which have been gained from genetically engineered mice, are also mentioned. Antioxid. Redox Signal. 15, 535–550. PMID:21126212

  7. Acute and chronic effects of dysfunction of right ventricular outflow tract components on right ventricular performance in a porcine model: implications for primary repair of tetralogy of fallot

    NARCIS (Netherlands)

    Bove, Thierry; Bouchez, Stefaan; de Hert, Stefan; Wouters, Patrick; de Somer, Filip; Devos, Daniel; Somers, Pamela; van Nooten, Guido

    2012-01-01

    This study investigates the contribution of infundibular versus pulmonary valve (PV) dysfunction on right ventricular (RV) function in a porcine model. Clinical outcome after repair of tetralogy of Fallot is determined by the adaptation of the right ventricle to the physiological sequelae of the

  8. Cell lineage identification and stem cell culture in a porcine model for the study of intestinal epithelial regeneration.

    Directory of Open Access Journals (Sweden)

    Liara M Gonzalez

    Full Text Available Significant advances in intestinal stem cell biology have been made in murine models; however, anatomical and physiological differences between mice and humans limit mice as a translational model for stem cell based research. The pig has been an effective translational model, and represents a candidate species to study intestinal epithelial stem cell (IESC driven regeneration. The lack of validated reagents and epithelial culture methods is an obstacle to investigating IESC driven regeneration in a pig model. In this study, antibodies against Epithelial Adhesion Molecule 1 (EpCAM and Villin marked cells of epithelial origin. Antibodies against Proliferative Cell Nuclear Antigen (PCNA, Minichromosome Maintenance Complex 2 (MCM2, Bromodeoxyuridine (BrdU and phosphorylated Histone H3 (pH3 distinguished proliferating cells at various stages of the cell cycle. SOX9, localized to the stem/progenitor cells zone, while HOPX was restricted to the +4/'reserve' stem cell zone. Immunostaining also identified major differentiated lineages. Goblet cells were identified by Mucin 2 (MUC2; enteroendocrine cells by Chromogranin A (CGA, Gastrin and Somatostatin; and absorptive enterocytes by carbonic anhydrase II (CAII and sucrase isomaltase (SIM. Transmission electron microscopy demonstrated morphologic and sub-cellular characteristics of stem cell and differentiated intestinal epithelial cell types. Quantitative PCR gene expression analysis enabled identification of stem/progenitor cells, post mitotic cell lineages, and important growth and differentiation pathways. Additionally, a method for long-term culture of porcine crypts was developed. Biomarker characterization and development of IESC culture in the porcine model represents a foundation for translational studies of IESC-driven regeneration of the intestinal epithelium in physiology and disease.

  9. A Liver-Centric Multiscale Modeling Framework for Xenobiotics.

    Directory of Open Access Journals (Sweden)

    James P Sluka

    Full Text Available We describe a multi-scale, liver-centric in silico modeling framework for acetaminophen pharmacology and metabolism. We focus on a computational model to characterize whole body uptake and clearance, liver transport and phase I and phase II metabolism. We do this by incorporating sub-models that span three scales; Physiologically Based Pharmacokinetic (PBPK modeling of acetaminophen uptake and distribution at the whole body level, cell and blood flow modeling at the tissue/organ level and metabolism at the sub-cellular level. We have used standard modeling modalities at each of the three scales. In particular, we have used the Systems Biology Markup Language (SBML to create both the whole-body and sub-cellular scales. Our modeling approach allows us to run the individual sub-models separately and allows us to easily exchange models at a particular scale without the need to extensively rework the sub-models at other scales. In addition, the use of SBML greatly facilitates the inclusion of biological annotations directly in the model code. The model was calibrated using human in vivo data for acetaminophen and its sulfate and glucuronate metabolites. We then carried out extensive parameter sensitivity studies including the pairwise interaction of parameters. We also simulated population variation of exposure and sensitivity to acetaminophen. Our modeling framework can be extended to the prediction of liver toxicity following acetaminophen overdose, or used as a general purpose pharmacokinetic model for xenobiotics.

  10. Acute retinal ischemia caused by controlled low ocular perfusion pressure in a porcine model. Electrophysiological and histological characterisation

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Warfvinge, Karin; Scherfig, Erik

    2009-01-01

    The purpose of this study was to establish, and characterize a porcine model of acute, controlled retinal ischemia. The controlled retinal ischemia was produced by clamping the ocular perfusion pressure (OPP) in the left eye to 5 mm Hg for 2 h. The OPP was defined as mean arterial blood pressure...... of the amplitudes obtained in the experimental, left eye, and the control, right eye. Quantitative histology was performed to measure the survival of ganglion cells, amacrine cells and horizontal cells 2-6 weeks after the ischemic insult. An OPP of 5 mm Hg for 2h induced significant reductions in the amplitudes...... the ischemic insult. This model seems to be suitable for investigations of therapeutic initiatives in diseases involving acute retinal ischemia....

  11. Inhibition of early AAA formation by aortic intraluminal pentagalloyl glucose (PGG) infusion in a novel porcine AAA model

    DEFF Research Database (Denmark)

    Kloster, Brian O; Lund, Lars; Lindholt, Jes S

    2016-01-01

    to prevent or delay their expansion. In this study, we investigated whether intraluminal delivered pentagalloyl glucose (PGG) can impair the early AAA development in a porcine model. METHODS: The infrarenal aorta was exposed in thirty pigs. Twenty underwent an elastase based AAA inducing procedure and ten...... of these received an additional intraluminal PGG infusion. The final 10 were sham operated and served as controls. RESULTS: All pigs who only had an elastase infusion developed macroscopically expanding AAAs. In pigs treated with an additional PGG infusion the growth rate of the AP-diameter rapidly returned...... and histology. CONCLUSION: In our model, intraluminal delivered PGG is able to penetrate the aortic wall from the inside and impair the early AAA development by stabilizing the elastic lamellae and preserving their integrity. The principle holds a high clinical potential if it can be translated to human...

  12. Sodium nitroprusside enhanced cardiopulmonary resuscitation improves short term survival in a porcine model of ischemic refractory ventricular fibrillation.

    Science.gov (United States)

    Yannopoulos, Demetris; Bartos, Jason A; George, Stephen A; Sideris, George; Voicu, Sebastian; Oestreich, Brett; Matsuura, Timothy; Shekar, Kadambari; Rees, Jennifer; Aufderheide, Tom P

    2017-01-01

    Sodium nitroprusside (SNP) enhanced CPR (SNPeCPR) demonstrates increased vital organ blood flow and survival in multiple porcine models. We developed a new, coronary occlusion/ischemia model of prolonged resuscitation, mimicking the majority of out-of-hospital cardiac arrests presenting with shockable rhythms. SNPeCPR will increase short term (4-h) survival compared to standard 2015 Advanced Cardiac Life Support (ACLS) guidelines in an ischemic refractory ventricular fibrillation (VF), prolonged CPR model. Sixteen anesthetized pigs had the ostial left anterior descending artery occluded leading to ischemic VF arrest. VF was untreated for 5min. Basic life support was performed for 10min. At minute 10 (EMS arrival), animals received either SNPeCPR (n=8) or standard ACLS (n=8). Defibrillation (200J) occurred every 3min. CPR continued for a total of 45min, then the balloon was deflated simulating revascularization. CPR continued until return of spontaneous circulation (ROSC) or a total of 60min, if unsuccessful. SNPeCPR animals received 2mg of SNP at minute 10 followed by 1mg every 5min until ROSC. Standard ACLS animals received 0.5mg epinephrine every 5min until ROSC. Primary endpoints were ROSC and 4-h survival. All SNPeCPR animals (8/8) achieved sustained ROSC versus 2/8 standard ACLS animals within one hour of resuscitation (p=0.04). The 4-h survival was significantly improved with SNPeCPR compared to standard ACLS, 7/8 versus 1/8 respectively, p=0.0019. SNPeCPR significantly improved ROSC and 4-h survival compared with standard ACLS CPR in a porcine model of prolonged ischemic, refractory VF cardiac arrest. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Comparison of 3 vaccination strategies against porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and porcine circovirus type 2 on a 3 pathogen challenge model.

    Science.gov (United States)

    Jeong, Jiwoon; Kang, Ikjae; Kim, Seeun; Park, Kee Hwan; Park, Changhoon; Chae, Chanhee

    2018-01-01

    The objective of this study was to compare clinical, microbiologic, immunologic, and pathologic parameters in pigs each concurrently administered porcine reproductive and respiratory syndrome virus (PRRSV), Mycoplasma hyopneumoniae, and porcine circovirus type 2 (PCV2) vaccine from 1 of 2 commercial sources at 21 days of age and challenged with field strains of each of the 3 pathogens. Pigs were challenged with PRRSV and M. hyopneumoniae at 42 days of age (-14 days post-challenge, dpc) followed by a challenge with PCV2 at 56 days of age (0 dpc). Significant differences were observed between vaccinated challenged and unvaccinated challenged groups in clinical (average daily gain and clinical signs), microbiologic (viremia and nasal shedding), immunologic (antibodies and interferon-γ secreting cells), and pathologic (lesions) outcomes. Significant differences were observed among the 3 vaccinated challenged groups in microbiologic (nasal shedding of M. hyopneumoniae and viremia of PCV2) and immunologic ( M. hyopneumoniae - and PCV2-specific interferon-γ secreting cells) outcomes. The vaccination regimen for PRRSV vaccine, M. hyopneumoniae vaccine, and PCV2 vaccine is efficacious for controlling triple challenge with PRRSV, M. hyopneumoniae, and PCV2 from weaning to finishing period.

  14. Testing Danegaptide Effects on Kidney Function after Ischemia/Reperfusion Injury in a New Porcine Two Week Model.

    Directory of Open Access Journals (Sweden)

    Chris Amdisen

    Full Text Available Ischemia/reperfusion injury (I/R-I is a leading cause of acute kidney injury (AKI and is associated with increased mortality. Danegaptide is a selective modifier of the gap junction protein connexion 43. It has cytoprotective as well as anti-arrhythmic properties and has been shown to reduce the size of myocardial infarct in pigs. The aim of this study was to investigate the ischemia-protective effect of Danegaptide in a porcine renal I/R-I model with two weeks follow up.Unilateral renal I/R-I was induced in pigs by clamping the left renal artery over a two hour period. The model allowed examination of renal blood flow by magnetic resonance imaging (MRI and the measurement of single kidney GFR two weeks after injury. Eleven animals were randomized to Danegaptide-infusion while nine animals received placebo. Kidney histology and urinary neutrophil gelatinase-associated lipocalin (NGAL excretion were included as markers of AKI.Unilateral kidney I/R-I resulted in an immediate ~50% GFR reduction, associated with a four-fold increase in urinary NGAL-excretion. Fourteen days after I/R-I, the total GFR was ~75% of baseline with a significantly lower GFR in the injured left kidney compared to the right kidney. No differences in GFR were observed between the treated and non-treated animals immediately after I/R-I or at Day 14. Furthermore, no differences were observed in the urinary excretion of NGAL, renal blood flow or other markers of renal function.As expected this porcine renal I/R-I model was associated with reduced GFR two weeks after injury. Danegaptide did not improve renal function after I/R-I.

  15. Local and Global Function Model of the Liver

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

    2016-01-01

    Purpose: To develop a local and global function model in the liver based on regional and organ function measurements to support individualized adaptive radiation therapy (RT). Methods and Materials: A local and global model for liver function was developed to include both functional volume and the effect of functional variation of subunits. Adopting the assumption of parallel architecture in the liver, the global function was composed of a sum of local function probabilities of subunits, varying between 0 and 1. The model was fit to 59 datasets of liver regional and organ function measures from 23 patients obtained before, during, and 1 month after RT. The local function probabilities of subunits were modeled by a sigmoid function in relating to MRI-derived portal venous perfusion values. The global function was fitted to a logarithm of an indocyanine green retention rate at 15 minutes (an overall liver function measure). Cross-validation was performed by leave-m-out tests. The model was further evaluated by fitting to the data divided according to whether the patients had hepatocellular carcinoma (HCC) or not. Results: The liver function model showed that (1) a perfusion value of 68.6 mL/(100 g · min) yielded a local function probability of 0.5; (2) the probability reached 0.9 at a perfusion value of 98 mL/(100 g · min); and (3) at a probability of 0.03 [corresponding perfusion of 38 mL/(100 g · min)] or lower, the contribution to global function was lost. Cross-validations showed that the model parameters were stable. The model fitted to the data from the patients with HCC indicated that the same amount of portal venous perfusion was translated into less local function probability than in the patients with non-HCC tumors. Conclusions: The developed liver function model could provide a means to better assess individual and regional dose-responses of hepatic functions, and provide guidance for individualized treatment planning of RT.

  16. Early outcome in renal transplantation from large donors to small and size-matched recipients - a porcine experimental model

    DEFF Research Database (Denmark)

    Ravlo, Kristian; Chhoden, Tashi; Søndergaard, Peter

    2012-01-01

    in small recipients within 60 min after reperfusion. Interestingly, this was associated with a significant reduction in medullary RPP, while there was no significant change in the size-matched recipients. No difference was observed in urinary NGAL excretion between the groups. A significant higher level......Kidney transplantation from a large donor to a small recipient, as in pediatric transplantation, is associated with an increased risk of thrombosis and DGF. We established a porcine model for renal transplantation from an adult donor to a small or size-matched recipient with a high risk of DGF...... and studied GFR, RPP using MRI, and markers of kidney injury within 10 h after transplantation. After induction of BD, kidneys were removed from ∼63-kg donors and kept in cold storage for ∼22 h until transplanted into small (∼15 kg, n = 8) or size-matched (n = 8) recipients. A reduction in GFR was observed...

  17. Novel diffuse optics system for continuous tissue viability monitoring: extended recovery in vivo testing in a porcine flap model

    Science.gov (United States)

    Lee, Seung Yup; Pakela, Julia M.; Hedrick, Taylor L.; Vishwanath, Karthik; Helton, Michael C.; Chung, Yooree; Kolodziejski, Noah J.; Stapels, Christopher J.; McAdams, Daniel R.; Fernandez, Daniel E.; Christian, James F.; O'Reilly, Jameson; Farkas, Dana; Ward, Brent B.; Feinberg, Stephen E.; Mycek, Mary-Ann

    2017-02-01

    In reconstructive surgery, tissue perfusion/vessel patency is critical to the success of microvascular free tissue flaps. Early detection of flap failure secondary to compromise of vascular perfusion would significantly increase the chances of flap salvage. We have developed a compact, clinically-compatible monitoring system to enable automated, minimally-invasive, continuous, and quantitative assessment of flap viability/perfusion. We tested the system's continuous monitoring capability during extended non-recovery surgery using an in vivo porcine free flap model. Initial results indicated that the system could assess flap viability/perfusion in a quantitative and continuous manner. With proven performance, the compact form constructed with cost-effective components would make this system suitable for clinical translation.

  18. Reflex vocal fold adduction in the porcine model: the effects of stimuli delivered to various sensory nerves.

    Science.gov (United States)

    Woo, Jeong-Soo; Hundal, Jagdeep S; Sasaki, Clarence T; Abdelmessih, Mikhail W; Kelleher, Stephen P

    2008-10-01

    The aim of this study was to identify a panel of sensory nerves capable of eliciting an evoked glottic closure reflex (GCR) and to quantify the glottic closing force (GCF) of these responses in a porcine model. In 5 pigs, the internal branch of the superior laryngeal nerve (iSLN) and the trigeminal, pharyngeal plexus, glossopharyngeal, radial, and intercostal nerves were surgically isolated and electrically stimulated. During stimulation of each nerve, the GCR was detected by laryngeal electromyography and the GCF was measured with a pressure transducer. The only nerve that elicited the GCR in the 5 pigs was the iSLN. The average GCF was 288.9 mm Hg. This study demonstrates that the only afferent nerve that elicits the GCR in pigs is the iSLN, and that it should remain the focus of research for the rehabilitation of patients with absent or defective reflex vocal fold adduction.

  19. A hyaluronic acid membrane delivery system for cultured keratinocytes: clinical "take" rates in the porcine kerato-dermal model.

    Science.gov (United States)

    Myers, S R; Grady, J; Soranzo, C; Sanders, R; Green, C; Leigh, I M; Navsaria, H A

    1997-01-01

    The clinical take rates of cultured keratinocyte autografts are poor on a full-thickness wound unless a dermal bed is provided. Even under these circumstances two important problems are the time delay in growing autografts and the fragility of the grafts. A laser-perforated hyaluronic acid membrane delivery system allows grafting at early confluence without requiring dispase digestion to release grafts from their culture dishes. We designed this study to investigate the influence of this membrane on clinical take rates in an established porcine kerato-dermal grafting model. The study demonstrated a significant reduction in take as a result of halving the keratinocyte seeding density onto the membrane. The take rates, however, of grafts grown on the membrane at half or full conventional seeding density and transplanted to a dermal wound bed were comparable, if not better, than those of keratinocyte sheet grafts.

  20. Intracoronary Poloxamer 188 Prevents Reperfusion Injury in a Porcine Model of ST-Segment Elevation Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Jason A. Bartos, MD, PhD

    2016-06-01

    Full Text Available Poloxamer 188 (P188 is a nonionic triblock copolymer believed to prevent cellular injury after ischemia and reperfusion. This study compared intracoronary (IC infusion of P188 immediately after reperfusion with delayed infusion through a peripheral intravenous catheter in a porcine model of ST-segment elevation myocardial infarction (STEMI. STEMI was induced in 55 pigs using 45 min of endovascular coronary artery occlusion. Pigs were then randomized to 4 groups: control, immediate IC P188, delayed peripheral P188, and polyethylene glycol infusion. Heart tissue was collected after 4 h of reperfusion. Assessment of mitochondrial function or infarct size was performed. Mitochondrial yield improved significantly with IC P188 treatment compared with control animals (0.25% vs. 0.13%, suggesting improved mitochondrial morphology and survival. Mitochondrial respiration and calcium retention were also significantly improved with immediate IC P188 compared with control animals (complex I respiratory control index: 7.4 vs. 3.7; calcium retention: 1,152 nmol vs. 386 nmol. This benefit was only observed with activation of complex I of the mitochondrial respiratory chain, suggesting a specific effect from ischemia and reperfusion on this complex. Infarct size and serum troponin I were significantly reduced by immediate IC P188 infusion (infarct size: 13.9% vs. 41.1%; troponin I: 19.2 μg/l vs. 77.4 μg/l. Delayed P188 and polyethylene glycol infusion did not provide a significant benefit. These results demonstrate that intracoronary infusion of P188 immediately upon reperfusion significantly reduces cellular and mitochondrial injury after ischemia and reperfusion in this clinically relevant porcine model of STEMI. The timing and route of delivery were critical to achieve the benefit.

  1. Renal artery nerve distribution and density in the porcine model: biologic implications for the development of radiofrequency ablation therapies.

    Science.gov (United States)

    Tellez, Armando; Rousselle, Serge; Palmieri, Taylor; Rate, William R; Wicks, Joan; Degrange, Ashley; Hyon, Chelsea M; Gongora, Carlos A; Hart, Randy; Grundy, Will; Kaluza, Greg L; Granada, Juan F

    2013-12-01

    Catheter-based renal artery denervation has demonstrated to be effective in decreasing blood pressure among patients with refractory hypertension. The anatomic distribution of renal artery nerves may influence the safety and efficacy profile of this procedure. We aimed to describe the anatomic distribution and density of periarterial renal nerves in the porcine model. Thirty arterial renal sections were included in the analysis by harvesting a tissue block containing the renal arteries and perirenal tissue from each animal. Each artery was divided into 3 segments (proximal, mid, and distal) and assessed for total number, size, and depth of the nerves according to the location. Nerve counts were greatest proximally (45.62% of the total nerves) and decreased gradually distally (mid, 24.58%; distal, 29.79%). The distribution in nerve size was similar across all 3 sections (∼40% of the nerves, 50-100 μm; ∼30%, 0-50 μm; ∼20%, 100-200 μm; and ∼10%, 200-500 μm). In the arterial segments ∼45% of the nerves were located within 2 mm from the arterial wall whereas ∼52% of all nerves were located within 2.5 mm from the arterial wall. Sympathetic efferent fibers outnumbered sensory afferent fibers overwhelmingly, intermixed within the nerve bundle. In the porcine model, renal artery nerves are seen more frequently in the proximal segment of the artery. Nerve size distribution appears to be homogeneous throughout the artery length. Nerve bundles progress closer to the arterial wall in the distal segments of the artery. This anatomic distribution may have implications for the future development of renal denervation therapies. Crown Copyright © 2013. Published by Mosby, Inc. All rights reserved.

  2. Intracoronary infusion of Wharton’ jelly derived mesenchymal stem cells in the treatment of chronic ischemia cardiomyopathy in porcine model

    Directory of Open Access Journals (Sweden)

    Ning-kun ZHANG

    2015-11-01

    Full Text Available Objective To investigate the safety and efficacy of transplantation of allogeneic Wharton' jelly-derived mesenchymal stem cells (WJMSCs in a porcine model of chronic ischemia cardiomyopathy. Methods Cardiomyopathy models (CIMP were reproduced in 25 minipigs out of 29 by left anterior descending coronary artery balloon occlusion, and the 4 remains served as sham group. The left ventricular ejection fraction (LVEF was detected by echocardiography, and the value ≤45% was defined as successful modeling. Of that 25 minipigs, 5 died, 3 failed of modeling and 17 remains were successfully modelled. The dose safety experiment of WJMSCs transplantation was firstly performed in 3 successful models and 3 failed models. Three doses were teste d in turn at 6×106, 1×107 and 2×107 with 1 successful and 1 failed model for each dose, and TIMI 3 was considered safety dosage. The remainder 14 CIMP models were randomly assigned to transplantation group and control group (7 each, and given 2×107 WJMSCs intracoronary infusion or equal amounts of normal saline respectively. Echocardiography, histopathology and immunofluorescence tests were performed 8 weeks after WJMSCs transplantation. Results LVEF increased by 11.6% (P<0.01 and the left ventricular end systolic volume decreased by 4.1ml (P<0.05 in CIMP models 8 weeks after WJMSCs transplantation, while in control group the ventricular function further deteriorated (LVEF decreased from 42.8% to 35.9%, P<0.01 and the left ventricular further expanded [left ventricular end diastolic volume (LVEDV increased from 42.8±1.2ml to 46.7±1.3ml (P<0.05]. Histopathological assessment showed that the ventricular wall in the infarction area was significantly thickening and the vascular density in the border zone was obviously increased in transplantation group. Immunofluorescence test revealed that the injected Myc-WJMSCs survived in the immunocompetent host heart, and colocalized with cardiac troponin T, α-actin and

  3. Human precision-cut liver slices as a model to test antifibrotic drugs in the early onset of liver fibrosis

    NARCIS (Netherlands)

    Westra, Inge M.; Mutsaers, Henricus A. M.; Luangmonkong, Theerut; Hadi, Mackenzie; Oosterhuis, Dorenda; de Jong, Koert P.; Groothuis, Geny M. M.; Olinga, Peter

    Liver fibrosis is the progressive accumulation of connective tissue ultimately resulting in loss of organ function. Currently, no effective antifibrotics are available due to a lack of reliable human models. Here we investigated the fibrotic process in human precision-cut liver slices (PCLS) and

  4. Measurement and Finite Element Model Validation of Immature Porcine Brain-Skull Displacement during Rapid Sagittal Head Rotations.

    Science.gov (United States)

    Pasquesi, Stephanie A; Margulies, Susan S

    2018-01-01

    Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain-skull displacement in the neonatal piglet head ( n  = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain-skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain-skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain-skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain-skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations.

  5. Measurement and Finite Element Model Validation of Immature Porcine Brain–Skull Displacement during Rapid Sagittal Head Rotations

    Science.gov (United States)

    Pasquesi, Stephanie A.; Margulies, Susan S.

    2018-01-01

    Computational models are valuable tools for studying tissue-level mechanisms of traumatic brain injury, but to produce more accurate estimates of tissue deformation, these models must be validated against experimental data. In this study, we present in situ measurements of brain–skull displacement in the neonatal piglet head (n = 3) at the sagittal midline during six rapid non-impact rotations (two rotations per specimen) with peak angular velocities averaging 51.7 ± 1.4 rad/s. Marks on the sagittally cut brain and skull/rigid potting surfaces were tracked, and peak values of relative brain–skull displacement were extracted and found to be significantly less than values extracted from a previous axial plane model. In a finite element model of the sagittally transected neonatal porcine head, the brain–skull boundary condition was matched to the measured physical experiment data. Despite smaller sagittal plane displacements at the brain–skull boundary, the corresponding finite element boundary condition optimized for sagittal plane rotations is far less stiff than its axial counterpart, likely due to the prominent role of the boundary geometry in restricting interface movement. Finally, bridging veins were included in the finite element model. Varying the bridging vein mechanical behavior over a previously reported range had no influence on the brain–skull boundary displacements. This direction-specific sagittal plane boundary condition can be employed in finite element models of rapid sagittal head rotations. PMID:29515995

  6. Reduction of IFNα and IL-10 in central nervous system and increase in peripheral IL-8 in transgenic porcine Huntington´s disease model

    Czech Academy of Sciences Publication Activity Database

    Kovářová, Hana; Valeková, Ivona; Jarkovská, Karla; Kotrčová, Eva; Motlík, Jan; Gadher, S. J.

    2015-01-01

    Roč. 78, Suppl 2 (2015), s. 10-11 ISSN 1210-7859. [Conference on Animal Models for neurodegenerative Diseases /3./. 08.11.2015-10.11.2015, Liblice] R&D Projects: GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 Keywords : porcine Huntington ´s disease model * IFNα * IL-10 Subject RIV: EB - Genetics ; Molecular Biology

  7. POLARIZATION IMAGING AND SCATTERING MODEL OF CANCEROUS LIVER TISSUES

    Directory of Open Access Journals (Sweden)

    DONGZHI LI

    2013-07-01

    Full Text Available We apply different polarization imaging techniques for cancerous liver tissues, and compare the relative contrasts for difference polarization imaging (DPI, degree of polarization imaging (DOPI and rotating linear polarization imaging (RLPI. Experimental results show that a number of polarization imaging parameters are capable of differentiating cancerous cells in isotropic liver tissues. To analyze the contrast mechanism of the cancer-sensitive polarization imaging parameters, we propose a scattering model containing two types of spherical scatterers and carry on Monte Carlo simulations based on this bi-component model. Both the experimental and Monte Carlo simulated results show that the RLPI technique can provide a good imaging contrast of cancerous tissues. The bi-component scattering model provides a useful tool to analyze the contrast mechanism of polarization imaging of cancerous tissues.

  8. Development of a novel ex vivo porcine laparoscopic Heller myotomy and Nissen fundoplication training model (Toronto lap-Nissen simulator).

    Science.gov (United States)

    Ujiie, Hideki; Kato, Tatsuya; Hu, Hsin-Pei; Bauer, Patrycja; Patel, Priya; Wada, Hironobu; Lee, Daiyoon; Fujino, Kosuke; Schieman, Colin; Pierre, Andrew; Waddell, Thomas K; Keshavjee, Shaf; Darling, Gail E; Yasufuku, Kazuhiro

    2017-06-01

    Surgical trainees are required to develop competency in a variety of laparoscopic operations. Developing laparoscopic technical skills can be difficult as there has been a decrease in the number of procedures performed. This study aims to develop an inexpensive and anatomically relevant model for training in laparoscopic foregut procedures. An ex vivo , anatomic model of the human upper abdomen was developed using intact porcine esophagus, stomach, diaphragm and spleen. The Toronto lap-Nissen simulator was contained in a laparoscopic box-trainer and included an arch system to simulate the normal radial shape and tension of the diaphragm. We integrated the use of this training model as a part of our laparoscopic skills laboratory-training curriculum. Afterwards, we surveyed trainees to evaluate the observed benefit of the learning session. Twenty-five trainees and five faculty members completed a survey regarding the use of this model. Among the trainees, only 4 (16%) had experience with laparoscopic Heller myotomy and Nissen fundoplication. They reported that practicing with the model was a valuable use of their limited time, repeating the exercise would be of additional benefit, and that the exercise improved their ability to perform or assist in an actual case in the operating room. Significant improvements were found in the following subjective measures comparing pre- vs. post-training: (I) knowledge level (5.6 vs. 8.0, Pmyotomy and fundoplication.

  9. Preliminary Results of the Influence of Duodenojejunal Bypass in a Porcine Model of Streptozotocin-Induced Diabetes Mellitus.

    Science.gov (United States)

    Hiridis, S; Konstantinidis, K; Menenakos, E; Diamantis, Th; Papalois, A; Zografos, G

    2016-04-01

    Type 2 diabetic obese patients present with a normalization of plasma glucose levels shortly after most bariatric procedures, before any significant weight loss takes place. There is only scarce literature in the new field of metabolic surgery, with most experiments being performed on small animal models. Our aim is to develop a reliable large animal model for assessment of surgical correction of diabetes. Titrated doses of streptozotocin (STZ) were used for induction of diabetes mellitus. After standardization of the surgical technique to avoid any restrictive component, three groups were created, a duodenojejunal bypass (DJB; n = 4), a gastroileal conduit (GIC; n = 3) near the ileocecal valve, and a sham (control; n = 5) group. Preoperative and postoperative glycemic curves were recorded by means of intravenous glucose tolerance tests. Body weight fluctuations were recorded as well. Diabetes was successfully induced with the use of STZ in all cases. Animals in the sham group remained diabetic for 3 weeks after operation. There was normalization of blood glucose levels in the operative groups during the 3-week postoperative follow-up, without significant body weight changes. The duodenojejunal group resulted in stronger positive response of glycemia. STZ-induced diabetes in swine leads to a reliable large animal model for assessment of metabolic surgical procedures. STZ is an effective but highly toxic means for inducing stable diabetes in the sensitive porcine model. Duodenojejunal bypass, although less invasive, seems to exert better antidiabetic effects than gastroileal conduit.

  10. Penile enhancement using a porcine small intestinal submucosa graft in a rat model.

    Science.gov (United States)

    Leungwattanakij, S; Pummangura, N; Ratana-Olarn, K

    2006-01-01

    Several biodegradable materials have been experimented for penile enhancement, but none show the potential for clinical use. This study was designed to use porcine small intestinal submucosa (SIS) augmenting the normal tunica albuginea to increase the functional girth of the rat penis. In all, 20 adult male Sprague-Dawley rats constituted the study population. The animals were divided into two groups: group 1 consisted of the control (n=10) and group 2 (n=10) consisted of rats that underwent penile enhancement by a longitudinal I-shaped incision of the tunica albuginea on both sides, and the dissection of the plane between tunica albuginea and cavernosal tissue was carried out (n=10). The incision was then patched with a 3 x 10 mm2 piece of SIS, using a 6/0 nylon suture material. The penile length and mid-circumference were then measured using a Vernier Caliper before and 2 months after surgery. All rat penises underwent histological examination using Masson's trichome and Verhoff's van Giesen's stain for collagen and elastic fibers. The penile length, mid-circumference and degree of fibrosis score were expressed as mean+/-s.e. (standard error) and analyzed using a Wilcoxon rank-sum test. A statistical significance was accepted at P-value enhancement.

  11. The effect of percutaneous transmyocardial laser revascularization on left ventricular function in a porcine model of hibernating myocardium

    International Nuclear Information System (INIS)

    Almeda, Francis Q.; Glock, Dana; Sandelski, Joanne; Ibrahim, Osama; Macioch, James E.; Allen, Trisha; Dainauskas, John R.; Parrillo, Joseph E.; Snell, R. Jeffrey; Schaer, Gary L.

    2004-01-01

    Background: Hibernating myocardium is defined as a state of persistently impaired myocardial function at rest due to reduced coronary blood flow that can partially or completely be restored to normal if the myocardial oxygen supply/demand relationship is favorably altered. Percutaneous laser revascularization (PMR) is an emerging catheter-based technique that involves creating channels in the myocardium, directly through a percutaneous approach with a laser delivery system, and has been shown to reduce symptoms in patients with severe refractory angina; however, its effect on improving regional wall motion abnormalities in hibernating myocardium has not been clearly established. We sought to determine the effect of PMR using the Eclipse System (Cardiogenesis) on left ventricular function in a porcine model of hibernating myocardium. Methods: A model of hibernating myocardium was created by placement of an ameroid constrictor in the proximal left anterior descending artery of a 35 kg male Yorkshire pig. The presence of hibernating myocardium was confirmed with dobutamine stress echocardiography (DSE) and defined as severe hypocontractility at rest, with an improvement in systolic wall thickening with low-dose dobutamine in myocardial regions with a subsequent deterioration in function at peak stress (biphasic response). After the demonstration of hibernating myocardium, PMR was performed in the area of hypocontractile function, and the serial echocardiography was performed. The echocardiograms were reviewed by an experienced echocardiologist blinded to the results, and regional wall motion was assessed using the American Society of Echocardiography Wall Motion Score. Six weeks after PMR, the animal was sacrificed and the heart sent for histopathologic studies. Results: A comparison of the regional wall motion function of the area distal to the ameroid constrictor and in the contralateral wall at baseline, post-ameroid placement, and post-PMR was performed

  12. Evaluation of adenosine preconditioning with {sup 99m}Tc-His{sub 10}-annexin V in a porcine model of myocardium ischemia and reperfusion injury: preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Ye Fei [Department of Cardiology, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); Fang Wei [Cardiovascular Institute and Fuwai Hospital, No. 167 Bei-Li-Shi-Lu, Beijing 100037 (China); Wang Feng, E-mail: fengwang1972cn@gmail.co [Department of Nuclear Medicine, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Hua Zichun [State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Wang Zizheng [Department of Nuclear Medicine, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); Yang Xiang [State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2011-05-15

    Purpose: The goal of this study was to evaluate the feasibility of {sup 99m}Tc-His{sub 10}-annexin V for the detection of acute myocardial cell death and to assess the effect of adenosine preconditioning in a porcine model of myocardium ischemia and reperfusion injury (RI). Materials and Methods: {sup 99m}Tc-His{sub 10}-annexin V was prepared by one-step direct labeling, and RCP and radiostability were tested. The binding of {sup 99m}Tc-His{sub 10}-annexin V to apoptosis was validated in vitro using camptothecin-induced Jurkat cells. In vivo biodistribution was determined in mice by the dissection method. Ischemia of 20-30 min was induced by balloon occlusion of the epicardial coronary artery of the porcine model (n=14). Adenosine was infused intravenously in six pigs before coronary occlusion. {sup 99m}Tc-His{sub 10}-annexin V (n=12) was injected intravenously at 1 h after reperfusion. SPECT/CT was acquired at 3 h postinjection. Myocardial perfusion imaging (MPI) with {sup 99m}Tc-MIBI was also performed 1 day after His{sub 10}-annexin V imaging. Cardiac tissues were analyzed postmortem using hematoxylin-and-eosin and TUNEL staining. Caspase-3 activity was measured to confirm the presence of apoptosis. Results: {sup 99m}Tc-His{sub 10}-annexin V had a RCP >98% and high stability 2 h after radiolabeling; it could bind to apoptotic cells with high affinity. Biodistribution of {sup 99m}Tc-His{sub 10}-annexin V showed a predominant uptake in the kidney and relatively low uptake in the myocardium, liver and gastrointestinal tract; rapid clearance from blood and kidney was observed. In the untreated group, intense uptake of His{sub 10}-annexin V was visualized in the defect which was shown in MPI, whereas in the adenosine group a mild uptake of {sup 99m}Tc-His{sub 10}-annexin was found in the risk area which showed no defects in the {sup 99m}Tc-MIBI image. TUNEL staining and activated caspase-3 confirmed the ongoing apoptosis in RI. Adenosine preconditioning significantly

  13. Long-Term Adult Feline Liver Organoid Cultures for Disease Modeling of Hepatic Steatosis

    Directory of Open Access Journals (Sweden)

    Hedwig S. Kruitwagen

    2017-04-01

    Full Text Available Summary: Hepatic steatosis is a highly prevalent liver disease, yet research is hampered by the lack of tractable cellular and animal models. Steatosis also occurs in cats, where it can cause severe hepatic failure. Previous studies demonstrate the potential of liver organoids for modeling genetic diseases. To examine the possibility of using organoids to model steatosis, we established a long-term feline liver organoid culture with adult liver stem cell characteristics and differentiation potential toward hepatocyte-like cells. Next, organoids from mouse, human, dog, and cat liver were provided with fatty acids. Lipid accumulation was observed in all organoids and interestingly, feline liver organoids accumulated more lipid droplets than human organoids. Finally, we demonstrate effects of interference with β-oxidation on lipid accumulation in feline liver organoids. In conclusion, feline liver organoids can be successfully cultured and display a predisposition for lipid accumulation, making them an interesting model in hepatic steatosis research. : In this study Kruitwagen and colleagues establish and characterize a feline liver organoid culture, which has adult stem cell properties and can be differentiated toward hepatocyte-like cells. They propose liver organoids as a tool to model hepatic steatosis and show that feline liver organoids accumulate more lipids than human organoids when provided with excess fatty acids. Keywords: feline liver organoids, adult liver stem cells, hepatic steatosis, disease modeling, feline hepatic lipidosis, species differences

  14. Evaluation of human acellular dermis versus porcine acellular dermis in an in vivo model for incisional hernia repair.

    Science.gov (United States)

    Ngo, Manh-Dan; Aberman, Harold M; Hawes, Michael L; Choi, Bryan; Gertzman, Arthur A

    2011-05-01

    Incisional hernias commonly occur following abdominal wall surgery. Human acellular dermal matrices (HADM) are widely used in abdominal wall defect repair. Xenograft acellular dermal matrices, particularly those made from porcine tissues (PADM), have recently experienced increased usage. The purpose of this study was to compare the effectiveness of HADM and PADM in the repair of incisional abdominal wall hernias in a rabbit model. A review from earlier work of differences between human allograft acellular dermal matrices (HADM) and porcine xenograft acellular dermal matrices (PADM) demonstrated significant differences (P strength 15.7 MPa vs. 7.7 MPa for HADM and PADM, respectively. Cellular (fibroblast) infiltration was significantly greater for HADM vs. PADM (Armour). The HADM exhibited a more natural, less degraded collagen by electrophoresis as compared to PADM. The rabbit model surgically established an incisional hernia, which was repaired with one of the two acellular dermal matrices 3 weeks after the creation of the abdominal hernia. The animals were euthanized at 4 and 20 weeks and the wounds evaluated. Tissue ingrowth into the implant was significantly faster for the HADM as compared to PADM, 54 vs. 16% at 4 weeks, and 58 vs. 20% for HADM and PADM, respectively at 20 weeks. The original, induced hernia defect (6 cm(2)) was healed to a greater extent for HADM vs. PADM: 2.7 cm(2) unremodeled area for PADM vs. 1.0 cm² for HADM at 20 weeks. The inherent uniformity of tissue ingrowth and remodeling over time was very different for the HADM relative to the PADM. No differences were observed at the 4-week end point. However, the 20-week data exhibited a statistically different level of variability in the remodeling rate with the mean standard deviation of 0.96 for HADM as contrasted to a mean standard deviation of 2.69 for PADM. This was significant with P < 0.05 using a one tail F test for the inherent variability of the standard deviation. No

  15. Gingiva laser welding: preliminary study on an ex vivo porcine model.

    Science.gov (United States)

    Rasca, Emilia; Nyssen-Behets, Catherine; Tielemans, Marc; Peremans, André; Hendaoui, Nordine; Heysselaer, Daniel; Romeo, Umberto; Nammour, Samir

    2014-08-01

    The use of lasers to fuse different tissues has been studied for 50 years. As none of these experiments concerned the oral soft tissues, our objective was to assess the feasibility of laser gingiva welding. Porcine full-thickness gingival flaps served to prepare calibrated samples in the middle of which a 2 cm long incision was closed, either by conventional suture or by laser tissue welding (LTW). To determine the irradiation conditions yielding the best tensile strength, 13 output power values, from 0.5 to 5 W, delivered either at 10 Hz or in continuous wave mode, were tested on six indocyanine green (ICG) concentrations, from 8% to 13% (588 samples). Then, some samples served to compare the tensile strength between the laser welded and the sutured gingiva; the other samples were histologically processed in order to evaluate the thermal damage extent. The temperature rise during the LTW was measured by thermocouples. Another group of 12 samples was used to measure the temperature elevation by thermal camera. In the laser welding groups, the best tensile strength (pwelded gingiva at 4.5 W, 10 Hz, and 9% ICG solution. The mean temperature was 74±5.4°C at the upper surface and 42±8.9°C at the lower surface. The damaged zone averaged 333 μm at the upper surface. The 808 nm diode laser associated with ICG can achieve oral mucosa LTW, which is conceivable as a promising technique of gingival repair.

  16. Diagnostic accuracy of a novel software technology for detecting pneumothorax in a porcine model.

    Science.gov (United States)

    Summers, Shane M; Chin, Eric J; April, Michael D; Grisell, Ronald D; Lospinoso, Joshua A; Kheirabadi, Bijan S; Salinas, Jose; Blackbourne, Lorne H

    2017-09-01

    Our objective was to measure the diagnostic accuracy of a novel software technology to detect pneumothorax on Brightness (B) mode and Motion (M) mode ultrasonography. Ultrasonography fellowship-trained emergency physicians performed thoracic ultrasonography at baseline and after surgically creating a pneumothorax in eight intubated, spontaneously breathing porcine subjects. Prior to pneumothorax induction, we captured sagittal M-mode still images and B-mode videos of each intercostal space with a linear array transducer at 4cm of depth. After collection of baseline images, we placed a chest tube, injected air into the pleural space in 250mL increments, and repeated the ultrasonography for pneumothorax volumes of 250mL, 500mL, 750mL, and 1000mL. We confirmed pneumothorax with intrapleural digital manometry and ultrasound by expert sonographers. We exported collected images for interpretation by the software. We treated each individual scan as a single test for interpretation by the software. Excluding indeterminate results, we collected 338M-mode images for which the software demonstrated a sensitivity of 98% (95% confidence interval [CI] 92-99%), specificity of 95% (95% CI 86-99), positive likelihood ratio (LR+) of 21.6 (95% CI 7.1-65), and negative likelihood ratio (LR-) of 0.02 (95% CI 0.008-0.046). Among 364 B-mode videos, the software demonstrated a sensitivity of 86% (95% CI 81-90%), specificity of 85% (81-91%), LR+ of 5.7 (95% CI 3.2-10.2), and LR- of 0.17 (95% CI 0.12-0.22). This novel technology has potential as a useful adjunct to diagnose pneumothorax on thoracic ultrasonography. Published by Elsevier Inc.

  17. Percutaneous Irreversible Electroporation Lung Ablation: Preliminary Results in a Porcine Model

    International Nuclear Information System (INIS)

    Deodhar, Ajita; Monette, Sébastien; Single, Gordon W.; Hamilton, William C.; Thornton, Raymond H.; Sofocleous, Constantinos T.; Maybody, Majid; Solomon, Stephen B.

    2011-01-01

    Objective: Irreversible electroporation (IRE) uses direct electrical pulses to create permanent “pores” in cell membranes to cause cell death. In contrast to conventional modalities, IRE has a nonthermal mechanism of action. Our objective was to study the histopathological and imaging features of IRE in normal swine lung. Materials and Methods: Eleven female swine were studied for hyperacute (8 h), acute (24 h), subacute (96 h), and chronic (3 week) effects of IRE ablation in lung. Paired unipolar IRE applicators were placed under computed tomography (CT) guidance. Some applicators were deliberately positioned near bronchovascular structures. IRE pulse delivery was synchronized with the cardiac rhythm only when ablation was performed within 2 cm of the heart. Contrast-enhanced CT scan was performed immediately before and after IRE and at 1 and 3 weeks after IRE ablation. Representative tissue was stained with hematoxylin and eosin for histopathology. Results: Twenty-five ablations were created: ten hyperacute, four acute, and three subacute ablations showed alveolar edema and necrosis with necrosis of bronchial, bronchiolar, and vascular epithelium. Bronchovascular architecture was maintained. Chronic ablations showed bronchiolitis obliterans and alveolar interstitial fibrosis. Immediate post-procedure CT images showed linear or patchy density along the applicator tract. At 1 week, there was consolidation that resolved partially or completely by 3 weeks. Pneumothorax requiring chest tube developed in two animals; no significant cardiac arrhythmias were noted. Conclusion: Our preliminary porcine study demonstrates the nonthermal and extracellular matrix sparing mechanism of action of IRE. IRE is a potential alternative to thermal ablative modalities.

  18. Muscle pathologies after cervical spine distortion-like exposure--a porcine model.

    Science.gov (United States)

    Gales, N; Kunz, S N; Rocksén, D; Arborelius, U P; Svensson, M Y; Hell, W; Schick, S

    2013-01-01

    Histological evaluation of porcine posterior cervical muscles after a forceful translational and extensional head retraction simulating high-speed rear end impact. Four anesthetized pigs were exposed to a cervical spine distortion (CSD)-like motion in a lying position. After 2 different survival times of 4 and 6 h (posttrauma), the pigs were euthanized and tissue sampling of posterior cervical muscles was performed. A standard histological staining method involving paraffin-embedded sections was used to analyze the muscles, focusing on injury signs like hemorrhage and inflammatory cell reaction. A pig that was not subjected to impact was used as a control pig and was subjected to the same procedure to exclude any potential artifacts from the autopsy. The differentiation of 8 different posterior neck muscles in the dissection process was successful in more than 50 percent for each muscle of interest. Staining and valid analysis was possible from all extracted samples. Muscle injuries to the deepest posterior neck muscles could be found, especially in the musculus obliquus samples, which showed laminar bleedings in 4 out of 4 samples. In addition, in 4 out of 4 samples we were able to see increased cellular reactions. The splenius muscle also showed bleeding in all 4 samples. All animals showed muscle injury signs in more than three quarters of analyzed neck muscles. Differences between survival times of 4 and 6 h in terms of muscular injury were not of primary interest and could not be found. By simulating a CSD-like motion we were able to confirm injuries in the posterior cervical muscles under severe loading conditions. Further studies need to be conducted to determine whether these muscle injuries also occur under lower exposure forces.

  19. The role of bile salt toxicity in the pathogenesis of bile duct injury after non-heart-beating porcine liver transplantation

    NARCIS (Netherlands)

    Yska, Marit J.; Buis, Carlijn I.; Monbaliu, Diethard; Schuurs, Theo A.; Gouw, Annette S. H.; Kahmann, Olivier N. H.; Visser, Dorien S.; Pirenne, Jacques; Porte, Robert J.

    2008-01-01

    Background. Intrahepatic bile duct strictures are a serious complication after non-heart-beating (NHB) liver transplantation. Bile salt toxicity has been identified as an important factor in the pathogenesis of bile duct injury and cholangiopathies. The role of bile salt toxicity in the development

  20. Porcine skin visible lesion thresholds for near-infrared lasers including modeling at two pulse durations and spot sizes.

    Science.gov (United States)

    Cain, C P; Polhamus, G D; Roach, W P; Stolarski, D J; Schuster, K J; Stockton, K L; Rockwell, B A; Chen, Bo; Welch, A J

    2006-01-01

    With the advent of such systems as the airborne laser and advanced tactical laser, high-energy lasers that use 1315-nm wavelengths in the near-infrared band will soon present a new laser safety challenge to armed forces and civilian populations. Experiments in nonhuman primates using this wavelength have demonstrated a range of ocular injuries, including corneal, lenticular, and retinal lesions as a function of pulse duration. American National Standards Institute (ANSI) laser safety standards have traditionally been based on experimental data, and there is scant data for this wavelength. We are reporting minimum visible lesion (MVL) threshold measurements using a porcine skin model for two different pulse durations and spot sizes for this wavelength. We also compare our measurements to results from our model based on the heat transfer equation and rate process equation, together with actual temperature measurements on the skin surface using a high-speed infrared camera. Our MVL-ED50 thresholds for long pulses (350 micros) at 24-h postexposure are measured to be 99 and 83 J cm(-2) for spot sizes of 0.7 and 1.3 mm diam, respectively. Q-switched laser pulses of 50 ns have a lower threshold of 11 J cm(-2) for a 5-mm-diam top-hat laser pulse.

  1. Inhibition of early AAA formation by aortic intraluminal pentagalloyl glucose (PGG) infusion in a novel porcine AAA model.

    Science.gov (United States)

    Kloster, Brian O; Lund, Lars; Lindholt, Jes S

    2016-05-01

    The vast majority of abdominal aortic aneurysms found in screening programs are small, and as no effective treatment exits, many will expand until surgery is indicated. Therefore, it remains intriguing to develop a safe and low cost treatment of these small aneurysms, that is able to prevent or delay their expansion. In this study, we investigated whether intraluminal delivered pentagalloyl glucose (PGG) can impair the early AAA development in a porcine model. The infrarenal aorta was exposed in thirty pigs. Twenty underwent an elastase based AAA inducing procedure and ten of these received an additional intraluminal PGG infusion. The final 10 were sham operated and served as controls. All pigs who only had an elastase infusion developed macroscopically expanding AAAs. In pigs treated with an additional PGG infusion the growth rate of the AP-diameter rapidly returned to physiological values as seen in the control group. In the elastase group, histology revealed more or less complete resolution of the elastic lamellae in the media while they were more abundant, coherent and structurally organized in the PGG group. The control group displayed normal physiological growth and histology. In our model, intraluminal delivered PGG is able to penetrate the aortic wall from the inside and impair the early AAA development by stabilizing the elastic lamellae and preserving their integrity. The principle holds a high clinical potential if it can be translated to human conditions, since it, if so, potentially could represent a new drug for stabilizing small abdominal aneurysms.

  2. Bridging a patient with acute liver failure to liver transplantation by the AMC-bioartificial liver

    NARCIS (Netherlands)

    van de Kerkhove, Maarten-Paul; di Florio, Ernesto; Scuderi, Vincenzo; Mancini, Antonio; Belli, Antonello; Bracco, Adele; Scala, Daniela; Scala, Simona; Zeuli, Laura; Di Nicuolo, Giuseppe; Amoroso, Pietro; Calise, Fulvio; Chamuleau, Robert A. F. M.

    2003-01-01

    Recently a phase I clinical trial has been started in Italy to bridge patients with acute liver failure (ALF) to orthotopic liver transplantation (OLT) by the AMC-bioartificial liver (AMC-BAL). The AMC-BAL is charged with 10 X 109 viable primary porcine hepatocytes isolated from a specified

  3. Comparative Analysis of the Regulatory T Cells Dynamics in Peripheral Blood in Human and Porcine Polytrauma

    Directory of Open Access Journals (Sweden)

    Rafael Serve

    2018-03-01

    Full Text Available BackgroundSeverely injured patients experience substantial immunological stress in the aftermath of traumatic insult, which often results in systemic immune dysregulation. Regulatory T cells (Treg play a key role in the suppression of the immune response and in the maintenance of immunological homeostasis. Little is known about their presence and dynamics in blood after trauma, and nothing is known about Treg in the porcine polytrauma model. Here, we assessed different subsets of Treg in trauma patients (TP and compared those to either healthy volunteers (HV or data from porcine polytrauma.MethodsPeripheral blood was withdrawn from 20 TP with injury severity score (ISS ≥16 at the admittance to the emergency department (ED, and subsequently on day 1 and at day 3. Ten HV were included as controls (ctrl. The porcine polytrauma model consisted of a femur fracture, liver laceration, lung contusion, and hemorrhagic shock resulting in an ISS of 27. After polytrauma, the animals underwent resuscitation and surgical fracture fixation. Blood samples were withdrawn before and immediately after trauma, 24 and 72 h later. Different subsets of Treg, CD4+CD25+, CD4+CD25+FoxP3+, CD4+CD25+CD127−, and CD4+CD25+CD127−FoxP3+ were characterized by flow cytometry.ResultsAbsolute cell counts of leukocytes were significantly increasing after trauma, and again decreasing in the follow-up in human and porcine samples. The proportion of human Treg in the peripheral blood of TP admitted to the ED was lower when compared to HV. Their numbers did not recover until 72 h after trauma. Comparable data were found for all subsets. The situation in the porcine trauma model was comparable with the clinical data. In porcine peripheral blood before trauma, we could identify Treg with the typical immunophenotype (CD4+CD25+CD127−, which were virtually absent immediately after trauma. Similar to the human situation, most of these cells expressed FoxP3, as assessed by

  4. Catheter-directed Intraportal Delivery of Endothelial Cell Therapy for Liver Regeneration: A Feasibility Study in a Large-Animal Model of Cirrhosis.

    Science.gov (United States)

    Lee, Kyungmouk Steve; Santagostino, Sara F; Li, David; Ramjit, Amit; Serrano, Kenneth; Ginsberg, Michael D; Ding, Bi-Sen; Rafii, Shahin; Madoff, David C

    2017-10-01

    Purpose To demonstrate the feasibility of imaging-guided catheter-directed delivery of endothelial cell therapy in a porcine model of cirrhosis for liver regeneration. Materials and Methods After approval from the institutional animal care and use committee, autologous liver endothelial cells were grown from core hepatic specimens from swine. Cirrhosis was induced in swine by means of transcatheter infusion of ethanol and iodized oil into the hepatic artery. Three weeks after induction of cirrhosis, the swine were randomly assigned to receive autologous cell therapy (endothelial cells, n = 4) or control treatment (phosphate-buffered saline, n = 4) by means of imaging-guided transhepatic intraportal catheterization. Fluorescence-activated cell sorting analysis was performed on biopsy samples 1 hour after therapy. Three weeks after intraportal delivery of endothelial cells, the swine were euthanized and the explanted liver underwent quantitative pathologic examination. Statistical analysis was performed with an unpaired t test by using unequal variance. Results Liver endothelial cells were successfully isolated, cultured, and expanded from eight 20-mm, 18-gauge hepatic core samples to 50 × 10 6 autologous cells per pig. Intraportal delivery of endothelial cell therapy or saline was technically successful in all eight swine, with no complications. Endothelial cells were present in the liver for a minimum of 1 hour after intraportal infusion. Swine treated with endothelial cell therapy showed mean levels of surrogate markers of hepatobiliary injury that were consistent with decreases in hepatic fibrosis and biliary ductal damage relative to the control animals, although statistical significance was not met in this pilot study: The mean percentage of positive pixels at Masson trichrome staining was 7.28% vs 5.57%, respectively (P = .20), the mean proliferation index with cytokeratin wide-spectrum was 2.55 vs 1.13 (P = .06), and the mean proliferation index with Ki67

  5. A low protein diet during pregnancy provokes a lasting shift of hepatic expression of genes related to cell cycle throughout ontogenesis in a porcine model

    Directory of Open Access Journals (Sweden)

    Oster Michael

    2012-03-01

    Full Text Available Abstract Background In rodent models and in humans the impact of gestational diets on the offspring's phenotype was shown experimentally and epidemiologically. Adverse environmental conditions during fetal development provoke an intrauterine adaptive response termed 'fetal programming', which may lead to both persistently biased responsiveness to extrinsic factors and permanent consequences for the organismal phenotype. This leads to the hypothesis that the offspring's transcriptome exhibits short-term and long-term changes, depending on the maternal diet. In order to contribute to a comprehensive inventory of genes and functional networks that are targets of nutritional programming initiated during fetal life, we applied whole-genome microarrays for expression profiling in a longitudinal experimental design covering prenatal, perinatal, juvenile, and adult ontogenetic stages in a porcine model. Pregnant sows were fed either a gestational low protein diet (LP, 6% CP or an adequate protein diet (AP, 12% CP. All offspring was nursed by foster sows receiving standard diets. After weaning, all offspring was fed standard diets ad libitum. Results Analyses of the hepatic gene expression of the offspring at prenatal (94 dies post conceptionem, dpc and postnatal stages (1, 28, 188 dies post natum, dpn included comparisons between dietary groups within stages as well as comparisons between ontogenetic stages within diets to separate diet-specific transcriptional changes and maturation processes. We observed differential expression of genes related to lipid metabolism (e.g. Fatty acid metabolism, Biosynthesis of steroids, Synthesis and degradation of ketone bodies, FA elongation in mitochondria, Bile acid synthesis and cell cycle regulation (e.g. Mitotic roles of PLK, G1/S checkpoint regulation, G2/M DNA damage checkpoint regulation. Notably, at stage 1 dpn no regulation of a distinct pathway was found in LP offspring. Conclusions The transcriptomic

  6. Characterisation of an in vitro blood-brain barrier model based on primary porcine capillary endothelial cells in monoculture or co-culture with primary rat or porcine astrocytes and pericytes

    DEFF Research Database (Denmark)

    Thomsen, Louiza Bohn; Larsen, Annette Burkhart; Moos, Torben

    to in vivo such as efflux transporters, tight junction proteins, and high transendothelial electric resistance (TEER). Primary BCECs are isolated from a variety of mammals such as rats, mice, cattle and pigs. Often bovine and porcine BCECs are cultured in monoculture or in co-culture with rat astrocytes......In vitro blood-brain barrier (BBB) models based on primary brain capillary endothelial cells (BCECs) in monoculture or in co-culture with primary astrocytes and pericytes are often applied for studying physiology of the BBB. Primary BCECs retain many morphological and biochemical properties similar...... obtained from neonatal rats which have been shown to strengthen the barrier properties of the BCECs. In this study, brain endothelial cells (PBECs), astrocytes and pericytes are isolated from pig brains donated by the local abattoir. The brains are from 6 month old domestic pigs. The availability and high...

  7. Porcine models of non-bacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE) caused by Staphylococcus aureus: a preliminary study.

    Science.gov (United States)

    Christiansen, Johanna G; Jensen, Henrik E; Johansen, Louise K; Kochl, Janne; Koch, Jørgen; Aalbaek, Bent; Nielsen, Ole L; Leifsson, Páll S

    2013-05-01

    Non-bacterial thrombotic endocarditis (NBTE) and, in particular, infective endocarditis (IE), are serious and potentially life-threatening diseases. An increasingly important agent of human IE is Staphylococcus aureus, which typically causes an acute endocarditis with high mortality. The study aim was to evaluate the pig as a model for non-bacterial as well as S. aureus-associated endocarditis, as these models would have several advantages compared to other laboratory animal models. Fourteen animals underwent surgery with placement of a plastic catheter in the left side of the heart. Six of the pigs did not receive a bacterial inoculation and were used to study the development of NBTE. The remaining eight pigs were inoculated intravenously once or twice with S. aureus, 10(5)-10(7) cfu/kg body weight. Two bacterial strains were used: S54F9 (porcine) and NCTC8325-4 (human). Clinical examination, echocardiography and bacterial blood cultures were used to diagnose and monitor the development of endocarditis. Animals were euthanized at between two and 15 days after catheter placement, and tissue samples were collected for bacteriology and histopathology. Pigs inoculated with 10(7) cfu/kg of S. aureus strain S54F9 developed clinical, echocardiographic and pathologic signs of IE. All other pigs, except one, developed NBTE. Serial blood cultures withdrawn after inoculation were positive in animals with IE, and negative in all other animals. S. aureus endocarditis was successfully induced in pigs with an indwelling cardiac catheter after intravenous inoculation of 10(7) cfu/kg of S. aureus strain S54F9. The model simulates typical pathological, clinical and diagnostic features seen in the human disease. Furthermore, NBTE was induced in all but one of the pigs without IE. Thus, the pig model can be used in future studies of the pathogenesis, diagnosis and therapy of NBTE and S. aureus endocarditis.

  8. Effects of dietary n-3 and n-6 fatty acids on clinical outcome in a porcine model on postoperative infection

    DEFF Research Database (Denmark)

    Langerhuus, Sine Nygaard; Tønnesen, Else Kirstine; Jensen, Karin Hjelholt

    2012-01-01

    , daily body-weight gain was determined in both periods. The preoperative changes in plasma and erythrocyte n-3 and n-6 LC-PUFA concentrations reflected the fatty acid compositions of the dietary treatments given, and plasma PGE2 metabolite concentration decreased in the fish oil treatment (P ...The present study was performed to evaluate the effects of dietary n-3 and n-6 long-chain PUFA (LC-PUFA) on clinical outcome in a porcine model on early aortic vascular prosthetic graft infection (AVPGI). A total of eighty-four pigs were randomised to a 35 d dietary treatment with 10 % (w/w) fish......·001). In the post-operative period, feed intake (P = 0·004) and body-weight gain (P = 0·038) were higher in the fish oil treatment compared with the sunflower oil treatment. The dietary treatments did not affect the number of days pigs were showing fever, weakness in the hindquarters or impaired general appearance...

  9. Urinary Excretion of Tetrodotoxin Modeled in a Porcine Renal Proximal Tubule Epithelial Cell Line, LLC-PK1

    Directory of Open Access Journals (Sweden)

    Takuya Matsumoto

    2017-07-01

    Full Text Available This study examined the urinary excretion of tetrodotoxin (TTX modeled in a porcine renal proximal tubule epithelial cell line, LLC-PK1. Time course profiles of TTX excretion and reabsorption across the cell monolayers at 37 °C showed that the amount of TTX transported increased linearly for 60 min. However, at 4 °C, the amount of TTX transported was approximately 20% of the value at 37 °C. These results indicate that TTX transport is both a transcellular and carrier-mediated process. Using a transport inhibition assay in which cell monolayers were incubated with 50 µM TTX and 5 mM of a transport inhibitor at 37 °C for 30 min, urinary excretion was significantly reduced by probenecid, tetraethylammonium (TEA, l-carnitine, and cimetidine, slightly reduced by p-aminohippuric acid (PAH, and unaffected by 1-methyl-4-phenylpyridinium (MPP+, oxaliplatin, and cefalexin. Renal reabsorption was significantly reduced by PAH, but was unaffected by probenecid, TEA and l-carnitine. These findings indicate that TTX is primarily excreted by organic cation transporters (OCTs and organic cation/carnitine transporters (OCTNs, partially transported by organic anion transporters (OATs and multidrug resistance-associated proteins (MRPs, and negligibly transported by multidrug and toxic compound extrusion transporters (MATEs.

  10. Comparison of shape memory polymer foam versus bare metal coil treatments in an in vivo porcine sidewall aneurysm model.

    Science.gov (United States)

    Horn, John; Hwang, Wonjun; Jessen, Staci L; Keller, Brandis K; Miller, Matthew W; Tuzun, Egemen; Hartman, Jonathan; Clubb, Fred J; Maitland, Duncan J

    2017-10-01

    The endovascular delivery of platinum alloy bare metal coils has been widely adapted to treat intracranial aneurysms. Despite the widespread clinical use of this technique, numerous suboptimal outcomes are possible. These may include chronic inflammation, low volume filling, coil compaction, and recanalization, all of which can lead to aneurysm recurrence, need for retreatment, and/or potential rupture. This study evaluates a treatment alternative in which polyurethane shape memory polymer (SMP) foam is used as an embolic aneurysm filler. The performance of this treatment method was compared to that of bare metal coils in a head-to-head in vivo study utilizing a porcine vein pouch aneurysm model. After 90 and 180 days post-treatment, gross and histological observations were used to assess aneurysm healing. At 90 days, the foam-treated aneurysms were at an advanced stage of healing compared to the coil-treated aneurysms and showed no signs of chronic inflammation. At 180 days, the foam-treated aneurysms exhibited an 89-93% reduction in cross-sectional area; whereas coiled aneurysms displayed an 18-34% area reduction. The superior healing in the foam-treated aneurysms at earlier stages suggests that SMP foam may be a viable alternative to current treatment methods. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1892-1905, 2017. © 2016 Wiley Periodicals, Inc.

  11. Evaluation of poly-L-lactic acid and polyglycolic acid resorbable stents for repair of tracheomalacia in a porcine model.

    Science.gov (United States)

    Nalwa, S S; Hartig, G K; Warner, T; Connor, N P; Thielman, M J

    2001-11-01

    Poly-L-lactic acid and polyglycolic acid (PLPG) resorbable stents may offer a potential solution to the problem of tracheomalacia. Advantages of this material include its strength, its versatile shaping characteristics, and its resorbability, which would preclude surgical removal and allow for airway growth. The purpose of this pilot study was to examine the usefulness of PLPG stents for temporary external airway stenting of tracheomalacia in a porcine model. A severe tracheomalacia was created in 6 pigs by submucosal resection of segments of tracheal cartilage from 6 consecutive rings. The PLPG stent was then shaped to recreate the tracheal contour and sutured to the underlying airway. Endoscopic photodocumentation during spontaneous ventilation was obtained before and after reconstruction. After creation of the malacic tracheal segment, all animals developed stridor, retractions, and cyanosis during spontaneous ventilation. After repair, all animals were extubated without complication. All animals survived the follow-up period of 9 to 12 weeks without evidence of respiratory distress and with rapid weight gain. Repeat bronchoscopy showed no evidence of airway collapse during spontaneous ventilation. Tracheal measurements revealed growth of the stented segment with a mild narrowing within the repaired region. Histologic examination showed preservation of respiratory epithelium. These preliminary findings suggest that PLPG stents may serve a useful role in the surgical management of tracheomalacia.

  12. Early decreased TLR2 expression on monocytes is associated with their reduced phagocytic activity and impaired maturation in a porcine polytrauma model

    Science.gov (United States)

    Schimunek, Lukas; Serve, Rafael; Teuben, Michel P. J.; Störmann, Philipp; Auner, Birgit; Woschek, Mathias; Pfeifer, Roman; Horst, Klemens; Simon, Tim-P.; Kalbitz, Miriam; Sturm, Ramona; Pape, Hans-C.; Hildebrand, Frank; Marzi, Ingo

    2017-01-01

    In their post-traumatic course, trauma patients suffering from multiple injuries have a high risk for immune dysregulation, which may contribute to post-injury complications and late mortality. Monocytes as specific effector cells of the innate immunity play a crucial role in inflammation. Using their Pattern Recognition Receptors (PRRs), notably Toll-Like Receptors (TLR), the monocytes recognize pathogens and/or pathogen-associated molecular patterns (PAMPs) and organize their clearance. TLR2 is the major receptor for particles of gram-positive bacteria, and initiates their phagocytosis. Here, we investigated the phagocytizing capability of monocytes in a long-term porcine severe trauma model (polytrauma, PT) with regard to their TLR2 expression. Polytrauma consisted of femur fracture, unilateral lung contusion, liver laceration, hemorrhagic shock with subsequent resuscitation and surgical fracture fixation. After induction of PT, peripheral blood was withdrawn before (-1 h) and directly after trauma (0 h), as well as 3.5 h, 5.5 h, 24 h and 72 h later. CD14+ monocytes were identified and the expression levels of H(S)LA-DR and TLR2 were investigated by flow cytometry. Additionally, the phagocytizing activity of monocytes by applying S. aureus particles labelled with pHrodo fluorescent reagent was also assessed by flow cytometry. Furthermore, blood samples from 10 healthy pigs were exposed to a TLR2-neutralizing antibody and subsequently to S. aureus particles. Using flow cytometry, phagocytizing activity was determined. P below 0.05 was considered significant. The number of CD14+ monocytes of all circulating leukocytes remained constant during the observational time period, while the percentage of CD14+H(S)LA-DR+ monocytes significantly decreased directly, 3.5 h and 5.5 h after trauma. The percentage of TLR2+ expressing cells out of all monocytes significantly decreased directly, 3.5 h and 5.5 h after trauma. The percentage of phagocytizing monocytes decreased

  13. Accuracy of spiral CT and 3D reconstruction in the detection of acute pulmonary embolism - development of an animal model using porcine lungs and technical specimens. Development of an animal model using porcine lungs and technical specimens

    International Nuclear Information System (INIS)

    Ries, B.G.; Kauczor, H.U.; Thelen, M.; Konerding, M.A.

    2001-01-01

    Purpose: To develop a model for simulation the CT morphologic situation of acute pulmonary embolism, to evaluate the accuracy of spiral CT and 3D reconstruction in the detection of artificial emboli and to investigate the influence of the orientation of emboli depending on z-axis orientation. Materials and Methods: Standardized artificial emboli made of wax and of defined size and shape were positioned into the pulmonary arteries of porcine lungs. Castings of the embolized pulmonary arterial trees were made by injection of a special opaque resin. After performance of spiral CT the data sets of the emboli and the pulmonary arteries were post-processed. The 3D segmentations were compared with the anatomic preparation to evaluate the accuracy of spiral CT/3D reconstruction-technique. Technical specimens simulating CT-morphology of acute embolized vessels underwent spiral CT in six different positions with respect to the z-axis. The CT data were reconstructed using a standardized and a contrastadapted method with interactive correction. The 3D emboli were analysed under qualitative aspects, and measurements of their extent were done. Results: In nearly 91%, there was complete agreement between CT and the corresponding findings at the anatomical preparation. Measurements of the 3D reconstructed technical specimens showed discrepancies of shape and size in dependence of the size of the original preparation, orientation and reconstruction technique. Overestimation up to 4 mm and underestimation to 2,2 mm were observed. Measurements of preparations with heights from 14 to 26 mm showed variances of ±1,5 mm (∝6-11%). Conclusion: The presented models are suitable to simulate CT morphology of acute pulmonary embolism under ex-vivo conditions. Accuracy in the detection of artificial emboli using spiral CT/3D reconstruction is affected by localization, size and orientation of the emboli and the reconstruction technique. (orig.) [de

  14. A novel porcine cell culture based protocol for the propagation of hepatitis E virus

    Directory of Open Access Journals (Sweden)

    Walter Chingwaru

    2016-08-01

    Full Text Available Objective: To present a comprehensive protocol for the processing of hepatitis E virus (HEV infected samples and propagation of the virus in primary cell cultures. Methods: Hepatitis E was extracted from porcine liver and faecal samples following standard protocols. The virus was then allowed to attach in the presence of trypsin to primary cells that included porcine and bovine intestinal epithelial cells and macrophages over a period of up to 3 h. The virus was propagated by rotational passaging through the cell cultures. Propagation was confirmed by immunoblotting. Results: We developed a comprehensive protocol to propagate HEV in porcine cell model that includes (i rotational culturing of the virus between porcine cell types, (ii pre-incubation of infected cells for 210 min, (iii use of a semi-complete cell culture medium supplemented with trypsin (0.33 µg/mL and (iv the use of simple immunoblot technique to detect the amplified virus based on the open reading frame 2/3. Conclusions: This protocol opens doors towards systematic analysis of the mechanisms that underlie the pathogenesis of HEV in vitro. Using our protocol, one can complete the propagation process within 6 to 9 d.

  15. Manipulation of nitric oxide in an animal model of acute liver injury ...

    African Journals Online (AJOL)

    We evaluated the impact of altering nitric oxide release on acute liver injury, the associated gut injury and bacterial translocation, at different time intervals. Methods: An acute rat liver injury model induced by D-galactosamine was used. Sprague Dawley rats were divided into four main groups: normal control, acute liver ...

  16. Continuous stroke volume estimation from aortic pressure using zero dimensional cardiovascular model: proof of concept study from porcine experiments.

    Science.gov (United States)

    Kamoi, Shun; Pretty, Christopher; Docherty, Paul; Squire, Dougie; Revie, James; Chiew, Yeong Shiong; Desaive, Thomas; Shaw, Geoffrey M; Chase, J Geoffrey

    2014-01-01

    Accurate, continuous, left ventricular stroke volume (SV) measurements can convey large amounts of information about patient hemodynamic status and response to therapy. However, direct measurements are highly invasive in clinical practice, and current procedures for estimating SV require specialized devices and significant approximation. This study investigates the accuracy of a three element Windkessel model combined with an aortic pressure waveform to estimate SV. Aortic pressure is separated into two components capturing; 1) resistance and compliance, 2) characteristic impedance. This separation provides model-element relationships enabling SV to be estimated while requiring only one of the three element values to be known or estimated. Beat-to-beat SV estimation was performed using population-representative optimal values for each model element. This method was validated using measured SV data from porcine experiments (N = 3 female Pietrain pigs, 29-37 kg) in which both ventricular volume and aortic pressure waveforms were measured simultaneously. The median difference between measured SV from left ventricle (LV) output and estimated SV was 0.6 ml with a 90% range (5th-95th percentile) -12.4 ml-14.3 ml. During periods when changes in SV were induced, cross correlations in between estimated and measured SV were above R = 0.65 for all cases. The method presented demonstrates that the magnitude and trends of SV can be accurately estimated from pressure waveforms alone, without the need for identification of complex physiological metrics where strength of correlations may vary significantly from patient to patient.

  17. Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Thiex, R.; Hans, F.J.; Gilsbach, J.M. [Aachen University, Department of Neurosurgery, Aachen (Germany); Krings, T. [Aachen University, Department of Neuroradiology, Aachen (Germany); Sellhaus, B. [Aachen University, Department of Neuropathology, Aachen (Germany)

    2005-10-01

    We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0{+-}3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8{+-}41.5 to 693.8{+-}72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

  18. Technical pitfalls in a porcine brain retraction model. The impact of brain spatula on the retracted brain tissue in a porcine model: a feasibility study and its technical pitfalls

    International Nuclear Information System (INIS)

    Thiex, R.; Hans, F.J.; Gilsbach, J.M.; Krings, T.; Sellhaus, B.

    2005-01-01

    We describe technical pitfalls of a porcine brain injury model for identifying primary and secondary pathological sequelae following brain retraction by brain spatula. In 16 anaesthetised male pigs, the right frontal brain was retracted in the interhemispheric fissure by a brain spatulum with varying pressures applied by the gravitational force of weights from 10 to 70 g for a duration of 30 min. The retracted brain tissue was monitored for changes in intracranial pressure and perfusion of the cortex using a Laser Doppler Perfusion Imager (MoorLDI). To evaluate the extent of oedema and cortical contusions, MRI was performed 30 min and 72 h after brain retraction. Following the MR scan, the retracted brain areas were histopathologically assessed using H and E and Fluoro-Jade B staining for neuronal damage. Sinus occlusion occurred in four animals, resulting in bilateral cortical contusions and extensive brain oedema. Retracting the brain with weights of 70 g (n=4) caused extensive oedema on FLAIR images that correlated clinically with a hemiparesis in three animals. Morphologically, an increased number of Fluoro-Jade B-positive neurons were found. A sequential decrease in weights prevented functional deficits in animals. A retraction pressure applied by 10-g weights (n=7) caused a mean rise in intracranial pressure to 4.0±3.1 mm Hg, and a decrement in mean cortical perfusion from 740.8±41.5 to 693.8±72.4 PU/cm2, (P<0.24). A meticulous dissection of the interhemispheric fissure and a reduction of weights to 10 g were found to be mandatory to study the cortical impact caused by brain spatula reproducibly. (orig.)

  19. Effects of Combined Milrinone and Levosimendan Treatment on Systolic and Diastolic Function During Postischemic Myocardial Dysfunction in a Porcine Model.

    Science.gov (United States)

    Axelsson, Birger; Häggmark, Sören; Svenmarker, Staffan; Johansson, Göran; Gupta, Anil; Tydén, Hans; Wouters, Patrick; Haney, Michael

    2016-09-01

    It is not known whether there are positive or negative interactions on ventricular function when a calcium-sensitizing inotrope is added to a phosphodiesterase inhibitor in the clinical setting of acute left ventricular (LV) dysfunction. We hypothesized that when levosimendan is added to milrinone treatment, there will be synergetic inotropic and lusitropic effects. This was tested in an anesthetized porcine postischemic global LV injury model, where ventricular pressures and volumes (conductance volumetry) were measured. A global ischemic injury was induced by repetitive left main stem coronary artery occlusions. Load-independent indices of LV function were assessed before and after ventricular injury, after milrinone treatment, and finally after addition of levosimendan to the milrinone treatment. Nonparametric, within-group comparisons were made. The protocol was completed in 12 pigs, 7 of which received the inotrope treatment and 5 of which served as controls. Milrinone led to positive lusitropic effects seen by improvement in tau after myocardial stunning. The addition of levosimendan to milrinone further increased lusitropic state. The latter effect could however not be attributed solely to levosimendan, since lusitropic state also improved spontaneously in time-matched controls at the same rate during the corresponding period. When levosimendan was added to milrinone infusion, there was no increase in systolic function (preload recruitable stroke work) compared to milrinone treatment alone. We conclude that in this model of postischemic LV dysfunction, there appears to be no clear improvement in systolic or diastolic function after addition of levosimendan to established milrinone treatment but also no negative effects of levosimendan in this context. © The Author(s) 2016.

  20. Pharmacokinetic/pharmacodynamic integration and modelling of oxytetracycline for the porcine pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida.

    Science.gov (United States)

    Dorey, L; Pelligand, L; Cheng, Z; Lees, P

    2017-10-01

    Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules of oxytetracycline for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) were determined in broth and porcine serum. PK/PD integration established ratios of average concentration over 48 h (C av0-48 h )/MIC of 5.87 and 0.27 μg/mL (P. multocida) and 0.70 and 0.85 μg/mL (A. pleuropneumoniae) for broth and serum MICs, respectively. PK/PD modelling of in vitro time-kill curves established broth and serum breakpoint values for area under curve (AUC 0-24 h )/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4 log 10 reductions in bacterial count. Doses were then predicted for each pathogen, based on Monte Carlo simulations, for: (i) bacteriostatic and bactericidal levels of kill; (ii) 50% and 90% target attainment rates (TAR); and (iii) single dosing and daily dosing at steady-state. For 90% TAR, predicted daily doses at steady-state for bactericidal actions were 1123 mg/kg (P. multocida) and 43 mg/kg (A. pleuropneumoniae) based on serum MICs. Lower TARs were predicted from broth MIC data; corresponding dose estimates were 95 mg/kg (P. multocida) and 34 mg/kg (A. pleuropneumoniae). © 2017 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.

  1. In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model.

    Science.gov (United States)

    Cressman, Erik N K; Shenoi, Mithun M; Edelman, Theresa L; Geeslin, Matthew G; Hennings, Leah J; Zhang, Yan; Iaizzo, Paul A; Bischof, John C

    2012-01-01

    To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.

  2. Assessment of Novel Anti-thrombotic Fusion Proteins for Inhibition of Stenosis in a Porcine Model of Arteriovenous Graft.

    Directory of Open Access Journals (Sweden)

    Christi M Terry

    Full Text Available Hemodialysis arteriovenous synthetic grafts (AVG provide high volumetric blood flow rates shortly after surgical placement. However, stenosis often develops at the vein-graft anastomosis contributing to thrombosis and early graft failure. Two novel fusion proteins, ANV-6L15 and TAP-ANV, inhibit the tissue factor/factor VIIa coagulation complex and the factor Xa/factor Va complex, respectively. Each inhibitor domain is fused to an annexin V domain that targets the inhibitor activity to sites of vascular injury to locally inhibit thrombosis. This study's objective was to determine if these antithrombotic proteins are safe and effective in inhibiting AVG stenosis.A bolus of either TAP-ANV or ANV-6L15 fusion protein was administered intravenously immediately prior to surgical placement of a synthetic graft between the external jugular vein and common carotid artery in a porcine model. At surgery, the vein and artery were irrigated with the anti-thrombotic fusion protein. Control animals received intravenous heparin. At 4 weeks, MRI was performed to evaluate graft patency, the pigs were then euthanized and grafts and attached vessels were explanted for histomorphometric assessment of neointimal hyperplasia at the vein-graft anastomosis. Blood was collected at surgery, immediately after surgery and at euthanasia for serum metabolic panels and coagulation chemistries.No acute thrombosis occurred in the control group or in either experimental group. No abnormal serum chemistries, activated clotting times or PT, PTT values were observed after treatment in experimental or control animals. However, at the vein-graft anastomosis, there was no difference between the control and experimental groups in cross-sectional lumen areas, as measured on MRI, and no difference in hyperplasia areas as determined by histomorphometry. These results suggest that local irrigation of TAP-ANV or ANV-6L15 intra-operatively was as effective in inhibiting acute graft thrombosis

  3. Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence.

    Science.gov (United States)

    Borel, Nicole; Dumrese, Claudia; Ziegler, Urs; Schifferli, Andrea; Kaiser, Carmen; Pospischil, Andreas

    2010-07-27

    Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV) may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. Infected cultures were investigated by immunofluorescence (IF), transmission electron microscopy (TEM) and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs), medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 microm in diameter. No re-differentiation into elementary bodies (EBs) was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections.

  4. Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence

    Directory of Open Access Journals (Sweden)

    Kaiser Carmen

    2010-07-01

    Full Text Available Abstract Background Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. Results Infected cultures were investigated by immunofluorescence (IF, transmission electron microscopy (TEM and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs, medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 μm in diameter. No re-differentiation into elementary bodies (EBs was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. Conclusions In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections.

  5. Impact of neonatal iron deficiency on hippocampal DNA methylation and gene transcription in a porcine biomedical model of cognitive development.

    Science.gov (United States)

    Schachtschneider, Kyle M; Liu, Yingkai; Rund, Laurie A; Madsen, Ole; Johnson, Rodney W; Groenen, Martien A M; Schook, Lawrence B

    2016-11-03

    Iron deficiency is a common childhood micronutrient deficiency that results in altered hippocampal function and cognitive disorders. However, little is known about the mechanisms through which neonatal iron deficiency results in long lasting alterations in hippocampal gene expression and function. DNA methylation is an epigenetic mark involved in gene regulation and altered by environmental factors. In this study, hippocampal DNA methylation and gene expression were assessed via reduced representation bisulfite sequencing and RNA-seq on samples from a previous study reporting reduced hippocampal-based learning and memory in a porcine biomedical model of neonatal iron deficiency. In total 192 differentially expressed genes (DEGs) were identified between the iron deficient and control groups. GO term and pathway enrichment analysis identified DEGs associated with hypoxia, angiogenesis, increased blood brain barrier (BBB) permeability, and altered neurodevelopment and function. Of particular interest are genes previously implicated in cognitive deficits and behavioral disorders in humans and mice, including HTR2A, HTR2C, PAK3, PRSS12, and NETO1. Altered genome-wide DNA methylation was observed across 0.5 million CpG and 2.4 million non-CpG sites. In total 853 differentially methylated (DM) CpG and 99 DM non-CpG sites were identified between groups. Samples clustered by group when comparing DM non-CpG sites, suggesting high conservation of non-CpG methylation in response to neonatal environment. In total 12 DM sites were associated with 9 DEGs, including genes involved in angiogenesis, neurodevelopment, and neuronal function. Neonatal iron deficiency leads to altered hippocampal DNA methylation and gene regulation involved in hypoxia, angiogenesis, increased BBB permeability, and altered neurodevelopment and function. Together, these results provide new insights into the mechanisms through which neonatal iron deficiency results in long lasting reductions in cognitive

  6. A Direct Comparison between Norepinephrine and Phenylephrine for Augmenting Spinal Cord Perfusion in a Porcine Model of Spinal Cord Injury.

    Science.gov (United States)

    Streijger, Femke; So, Kitty; Manouchehri, Neda; Gheorghe, Ana; Okon, Elena B; Chan, Ryan M; Ng, Benjamin; Shortt, Katelyn; Sekhon, Mypinder S; Griesdale, Donald E; Kwon, Brian K

    2018-03-28

    Current clinical guidelines recommend elevating the mean arterial blood pressure (MAP) to increase spinal cord perfusion in patients with acute spinal cord injury (SCI). This is typically achieved with vasopressors such as norepinephrine (NE) and phenylephrine (PE). These drugs differ in their pharmacological properties and potentially have different effects on spinal cord blood flow (SCBF), oxygenation (PO 2 ), and downstream metabolism after injury. Using a porcine model of thoracic SCI, we evaluated how these vasopressors influenced intraparenchymal SCBF, PO 2 , hydrostatic pressure, and metabolism within the spinal cord adjacent to the injury site. Yorkshire pigs underwent a contusion/compression SCI at T10 and were randomized to receive either NE or PE for MAP elevation of 20 mm Hg, or no MAP augmentation. Prior to injury, a combined SCBF/PO 2 sensor, a pressure sensor, and a microdialysis probe were inserted into the spinal cord adjacent to T10 at two locations: a "proximal" site and a "distal" site, 2 mm and 22 mm from the SCI, respectively. At the proximal site, NE and PE resulted in little improvement in SCBF during cord compression. Following decompression, NE resulted in increased SCBF and PO 2 , whereas decreased levels were observed for PE. However, both NE and PE were associated with a gradual decrease in the lactate to pyruvate (L/P) ratio after decompression. PE was associated with greater hemorrhage through the injury site than that in control animals. Combined, our results suggest that NE promotes better restoration of blood flow and oxygenation than PE in the traumatically injured spinal cord, thus providing a physiological rationale for selecting NE over PE in the hemodynamic management of acute SCI.

  7. The superiority of the autografts inactivated by high hydrostatic pressure to decellularized allografts in a porcine model.

    Science.gov (United States)

    Morimoto, Naoki; Mahara, Atsushi; Jinno, Chizuru; Ogawa, Mami; Kakudo, Natsuko; Suzuki, Shigehiko; Fujisato, Toshia; Kusumoto, Kenji; Yamaoka, Tetsuji

    2017-11-01

    We are developing a novel skin regeneration therapy in which the inactivation of nevus tissue via high hydrostatic pressure (HHP) is used in the reconstruction of the dermis in combination with a cultured epidermal autograft. In this study, we used a porcine skin graft model to explore whether autologous skin including cellular debris inactivated by HHP or allogeneic skin decellularized by HHP is better for dermal reconstruction. Grafts (n = 6) were prepared for five groups each: autologous skin without pressurization group (control group), autologous skin inactivated by 200 MPa group, autologous skin inactivated by 1000 MPa group, allogeneic skin decellularized by 200 MPa group, and allogeneic skin decellularized by 1000 MPa group. All of the grafts at 1, 4, and 12 weeks showed complete engraftment macroscopically. The mean areas of the grafts of the control group (p < 0.01) and autologous 200 MPa group (p < 0.01) were larger than that of the allogeneic 1000 MPa group at four weeks after implantation. The thickness of the control group and autologous 200 MPa group was comparable, and that of the autologous 200 MPa group was significantly thicker than that of the allogeneic 200 MPa group (p < 0.01). This suggests that the autologous dermis was superior to the allogeneic decellularized dermis as a skin graft, and that HHP at 200 MPa provided a better outcome than HHP at 1000 MPa. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2653-2661, 2017. © 2016 Wiley Periodicals, Inc.

  8. A review of the human vs. porcine female genital tract and associated immune system in the perspective of using minipigs as a model of human genital Chlamydia infection.

    Science.gov (United States)

    Lorenzen, Emma; Follmann, Frank; Jungersen, Gregers; Agerholm, Jørgen S

    2015-09-28

    Sexually transmitted diseases constitute major health issues and their prevention and treatment continue to challenge the health care systems worldwide. Animal models are essential for a deeper understanding of the diseases and the development of safe and protective vaccines. Currently a good predictive non-rodent model is needed for the study of genital chlamydia in women. The pig has become an increasingly popular model for human diseases due to its close similarities to humans. The aim of this review is to compare the porcine and human female genital tract and associated immune system in the perspective of genital Chlamydia infection. The comparison of women and sows has shown that despite some gross anatomical differences, the structures and proportion of layers undergoing cyclic alterations are very similar. Reproductive hormonal cycles are closely related, only showing a slight difference in cycle length and source of luteolysing hormone. The epithelium and functional layers of the endometrium show similar cyclic changes. The immune system in pigs is very similar to that of humans, even though pigs have a higher percentage of CD4(+)/CD8(+) double positive T cells. The genital immune system is also very similar in terms of the cyclic fluctuations in the mucosal antibody levels, but differs slightly regarding immune cell infiltration in the genital mucosa - predominantly due to the influx of neutrophils in the porcine endometrium during estrus. The vaginal flora in Göttingen Minipigs is not dominated by lactobacilli as in humans. The vaginal pH is around 7 in Göttingen Minipigs, compared to the more acidic vaginal pH around 3.5-5 in women. This review reveals important similarities between the human and porcine female reproductive tracts and proposes the pig as an advantageous supplementary model of human genital Chlamydia infection.

  9. Modeling toxicodynamic effects of trichloroethylene on liver in mouse model of autoimmune hepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Kathleen M., E-mail: gilbertkathleenm@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Reisfeld, Brad, E-mail: brad.reisfeld@colostate.edu [Colorado State University, Fort Collins, CO (United States); Zurlinden, Todd J., E-mail: tjzurlin@rams.colostate.edu [Colorado State University, Fort Collins, CO (United States); Kreps, Meagan N., E-mail: MNKreps@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Erickson, Stephen W., E-mail: serickson@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Blossom, Sarah J., E-mail: blossomsarah@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States)

    2014-09-15

    Chronic exposure to industrial solvent and water pollutant trichloroethylene (TCE) in female MRL +/+ mice generates disease similar to human autoimmune hepatitis. The current study was initiated to investigate why TCE-induced autoimmunity targeted the liver. Compared to other tissues the liver has an unusually robust capacity for repair and regeneration. This investigation examined both time-dependent and dose-dependent effects of TCE on hepatoprotective and pro-inflammatory events in liver and macrophages from female MRL +/+ mice. After a 12-week exposure to TCE in drinking water a dose-dependent decrease in macrophage production of IL-6 at both the transcriptional and protein level was observed. A longitudinal study similarly showed that TCE inhibited macrophage IL-6 production. In terms of the liver, TCE had little effect on expression of pro-inflammatory genes (Tnfa, Saa2 or Cscl1) until the end of the 40-week exposure. Instead, TCE suppressed hepatic expression of genes involved in IL-6 signaling (Il6r, gp130, and Egr1). Linear regression analysis confirmed liver histopathology in the TCE-treated mice correlated with decreased expression of Il6r. A toxicodynamic model was developed to estimate the effects of TCE on IL-6 signaling and liver pathology under different levels of exposure and rates of repair. This study underlined the importance of longitudinal studies in mechanistic evaluations of immuntoxicants. It showed that later-occurring liver pathology caused by TCE was associated with early suppression of hepatoprotection rather than an increase in conventional pro-inflammatory events. This information was used to create a novel toxicodynamic model of IL-6-mediated TCE-induced liver inflammation. - Highlights: • We developed a toxicodynamic model to study effects of trichloroethylene on liver. • We examined protective as well as pro-inflammatory events in the liver. • Trichloroethylene inhibits IL-6 production by macrophages. • Trichloroethylene

  10. Modeling toxicodynamic effects of trichloroethylene on liver in mouse model of autoimmune hepatitis

    International Nuclear Information System (INIS)

    Gilbert, Kathleen M.; Reisfeld, Brad; Zurlinden, Todd J.; Kreps, Meagan N.; Erickson, Stephen W.; Blossom, Sarah J.

    2014-01-01

    Chronic exposure to industrial solvent and water pollutant trichloroethylene (TCE) in female MRL +/+ mice generates disease similar to human autoimmune hepatitis. The current study was initiated to investigate why TCE-induced autoimmunity targeted the liver. Compared to other tissues the liver has an unusually robust capacity for repair and regeneration. This investigation examined both time-dependent and dose-dependent effects of TCE on hepatoprotective and pro-inflammatory events in liver and macrophages from female MRL +/+ mice. After a 12-week exposure to TCE in drinking water a dose-dependent decrease in macrophage production of IL-6 at both the transcriptional and protein level was observed. A longitudinal study similarly showed that TCE inhibited macrophage IL-6 production. In terms of the liver, TCE had little effect on expression of pro-inflammatory genes (Tnfa, Saa2 or Cscl1) until the end of the 40-week exposure. Instead, TCE suppressed hepatic expression of genes involved in IL-6 signaling (Il6r, gp130, and Egr1). Linear regression analysis confirmed liver histopathology in the TCE-treated mice correlated with decreased expression of Il6r. A toxicodynamic model was developed to estimate the effects of TCE on IL-6 signaling and liver pathology under different levels of exposure and rates of repair. This study underlined the importance of longitudinal studies in mechanistic evaluations of immuntoxicants. It showed that later-occurring liver pathology caused by TCE was associated with early suppression of hepatoprotection rather than an increase in conventional pro-inflammatory events. This information was used to create a novel toxicodynamic model of IL-6-mediated TCE-induced liver inflammation. - Highlights: • We developed a toxicodynamic model to study effects of trichloroethylene on liver. • We examined protective as well as pro-inflammatory events in the liver. • Trichloroethylene inhibits IL-6 production by macrophages. • Trichloroethylene

  11. Quantification of intervertebral displacement with a novel MRI-based modeling technique: Assessing measurement bias and reliability with a porcine spine model.

    Science.gov (United States)

    Mahato, Niladri K; Montuelle, Stephane; Goubeaux, Craig; Cotton, John; Williams, Susan; Thomas, James; Clark, Brian C

    2017-05-01

    The purpose of this study was to develop a novel magnetic resonance imaging (MRI)-based modeling technique for measuring intervertebral displacements. Here, we present the measurement bias and reliability of the developmental work using a porcine spine model. Porcine lumbar vertebral segments were fitted in a custom-built apparatus placed within an externally calibrated imaging volume of an open-MRI scanner. The apparatus allowed movement of the vertebrae through pre-assigned magnitudes of sagittal and coronal translation and rotation. The induced displacements were imaged with static (T 1 ) and fast dynamic (2D HYCE S) pulse sequences. These images were imported into animation software, in which these images formed a background 'scene'. Three-dimensional models of vertebrae were created using static axial scans from the specimen and then transferred into the animation environment. In the animation environment, the user manually moved the models (rotoscoping) to perform model-to-'scene' matching to fit the models to their image silhouettes and assigned anatomical joint axes to the motion-segments. The animation protocol quantified the experimental translation and rotation displacements between the vertebral models. Accuracy of the technique was calculated as 'bias' using a linear mixed effects model, average percentage error and root mean square errors. Between-session reliability was examined by computing intra-class correlation coefficients (ICC) and the coefficient of variations (CV). For translation trials, a constant bias (β 0 ) of 0.35 (±0.11) mm was detected for the 2D HYCE S sequence (p=0.01). The model did not demonstrate significant additional bias with each mm increase in experimental translation (β 1 Displacement=0.01mm; p=0.69). Using the T 1 sequence for the same assessments did not significantly change the bias (p>0.05). ICC values for the T 1 and 2D HYCE S pulse sequences were 0.98 and 0.97, respectively. For rotation trials, a constant bias (

  12. Characterization of the porcine TOR1A gene: The first step towards generation of a pig model for dystonia

    DEFF Research Database (Denmark)

    Henriksen, Carina; Madsen, Lone Bruhn; Bendixen, Christian

    2009-01-01

    . The TOR1A gene was demonstrated to be localized on porcine chromosome 1. Single nucleotide polymorphism (SNP) analysis revealed several SNPs in the porcine TOR1A gene, both in the coding region and also in the 3′ UTR region. Overexpression of mutant (Δ∆E303-304) porcine TorsinA in neuroblastoma cells...

  13. Extracellular Vesicles from Human Liver Stem Cells Reduce Injury in an Ex Vivo Normothermic Hypoxic Rat Liver Perfusion Model.

    Science.gov (United States)

    Rigo, Federica; De Stefano, Nicola; Navarro-Tableros, Victor; David, Ezio; Rizza, Giorgia; Catalano, Giorgia; Gilbo, Nicholas; Maione, Francesca; Gonella, Federica; Roggio, Dorotea; Martini, Silvia; Patrono, Damiano; Salizzoni, Mauro; Camussi, Giovanni; Romagnoli, Renato

    2018-05-01

    The gold standard for organ preservation before transplantation is static cold storage, which is unable to fully protect suboptimal livers from ischemia/reperfusion injury. An emerging alternative is normothermic machine perfusion (NMP), which permits organ reconditioning. Here, we aimed to explore the feasibility of a pharmacological intervention on isolated rat livers by using a combination of NMP and human liver stem cells-derived extracellular vesicles (HLSC-EV). We established an ex vivo murine model of NMP capable to maintain liver function despite an ongoing hypoxic injury induced by hemodilution. Livers were perfused for 4 hours without (control group, n = 10) or with HLSC-EV (treated group, n = 9). Bile production was quantified; perfusate samples were collected hourly to measure metabolic (pH, pO2, pCO2) and cytolysis parameters (AST, alanine aminotransferase, lactate dehydrogenase). At the end of perfusion, we assessed HLSC-EV engraftment by immunofluorescence, tissue injury by histology, apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, tissue hypoxia-inducible factor 1-α, and transforming growth factor-beta 1 RNA expression by quantitative reverse transcription-polymerase chain reaction. During hypoxic NMP, livers were able to maintain homeostasis and produce bile. In the treated group, AST (P = 0.018) and lactate dehydrogenase (P = 0.032) levels were significantly lower than those of the control group at 3 hours of perfusion, and AST levels persisted lower at 4 hours (P = 0.003). By the end of NMP, HLSC-EV had been uptaken by hepatocytes, and EV treatment significantly reduced histological damage (P = 0.030), apoptosis (P = 0.049), and RNA overexpression of hypoxia-inducible factor 1-α (P < 0.0001) and transforming growth factor-beta 1 (P = 0.014). HLSC-EV treatment, even in a short-duration model, was feasible and effectively reduced liver injury during hypoxic NMP.

  14. Fumarylacetoacetate hydrolase deficient pigs are a novel large animal model of metabolic liver disease

    Directory of Open Access Journals (Sweden)

    Raymond D. Hickey

    2014-07-01

    FAH-deficiency produced a lethal defect in utero that was corrected by administration of 2-(2-nitro-4-trifluoromethylbenzoyl-1,3 cyclohexanedione (NTBC throughout pregnancy. Animals on NTBC were phenotypically normal at birth; however, the animals were euthanized approximately four weeks after withdrawal of NTBC due to clinical decline and physical examination findings of severe liver injury and encephalopathy consistent with acute liver failure. Biochemical and histological analyses, characterized by diffuse and severe hepatocellular damage, confirmed the diagnosis of severe liver injury. FAH−/− pigs provide the first genetically engineered large animal model of a metabolic liver disorder. Future applications of FAH−/− pigs include discovery research as a large animal model of HT1 and spontaneous acute liver failure, and preclinical testing of the efficacy of liver cell therapies, including transplantation of hepatocytes, liver stem cells, and pluripotent stem cell-derived hepatocytes.

  15. Modeling toxicodynamic effects of trichloroethylene on liver in mouse model of autoimmune hepatitis.

    Science.gov (United States)

    Gilbert, Kathleen M; Reisfeld, Brad; Zurlinden, Todd J; Kreps, Meagan N; Erickson, Stephen W; Blossom, Sarah J

    2014-09-15

    Chronic exposure to industrial solvent and water pollutant trichloroethylene (TCE) in female MRL+/+mice generates disease similar to human autoimmune hepatitis. The current study was initiated to investigate why TCE-induced autoimmunity targeted the liver. Compared to other tissues the liver has an unusually robust capacity for repair and regeneration. This investigation examined both time-dependent and dose-dependent effects of TCE on hepatoprotective and pro-inflammatory events in liver and macrophages from female MRL+/+mice. After a 12-week exposure to TCE in drinking water a dose-dependent decrease in macrophage production of IL-6 at both the transcriptional and protein level was observed. A longitudinal study similarly showed that TCE inhibited macrophage IL-6 production. In terms of the liver, TCE had little effect on expression of pro-inflammatory genes (Tnfa, Saa2 or Cscl1) until the end of the 40-week exposure. Instead, TCE suppressed hepatic expression of genes involved in IL-6 signaling (Il6r, gp130, and Egr1). Linear regression analysis confirmed liver histopathology in the TCE-treated mice correlated with decreased expression of Il6r. A toxicodynamic model was developed to estimate the effects of TCE on IL-6 signaling and liver pathology under different levels of exposure and rates of repair. This study underlined the importance of longitudinal studies in mechanistic evaluations of immuntoxicants. It showed that later-occurring liver pathology caused by TCE was associated with early suppression of hepatoprotection rather than an increase in conventional pro-inflammatory events. This information was used to create a novel toxicodynamic model of IL-6-mediated TCE-induced liver inflammation. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Effects of 32P radioactive stents on in-stent restenosis in a double stent injury model of the porcine coronary arteries

    International Nuclear Information System (INIS)

    Kim, Han-Soo; Chan, Rosanna C.; Kollum, Marc; Au, Arthur; Tio, Fermin O.; Yazdi, Hamid A.; Ajani, Andrew E.; Waksman, Ron

    2001-01-01

    Background: The major limitation of coronary stenting remains in-stent restenosis, due to the development of neointimal proliferation. Radioactive stents have demonstrated the ability to reduce this proliferation in the healthy nonatherosclerotic porcine animal model. However, inhibition of tissue proliferation in the in-stent restenotic lesion in a porcine model is not well characterized. The objective of this study was to examine the efficacy and safety of the 32 P radioactive stent for the treatment of in-stent restenosis in a double stent injury model of the porcine coronaries. Methods and Materials: Eighteen coronary arteries in 9 pigs underwent nonradioactive stent (8 mm in length) implantation. Thirty days after the initial stent implantation, a 32 P radioactive stent (18 mm in length) with an activity of 0 and 18 μCi was implanted to cover the initial stent. The swine were killed 30 days after the second stent implantation. Histomorphometric analysis was performed for vessel area (VA), stent strut area (SSA), intimal area (IA), and lumen area (LA). Results: Injury scores, VA, SSA, and LA were similar among the control and radiated groups. Neointimal formation was significantly reduced after placement of radioactive stents as compared to control in both the overlapped (0.93±0.12 vs. 1.31±0.51 mm 2 , p 2 , p 32 P radioactive stents may be safe and effective in reducing neointimal formation leading to in-stent restenosis. Longer follow-up will be required to examine whether these positive findings can be maintained

  17. An ex vivo porcine skin model to evaluate pressure-reducing devices of different mechanical properties used for pressure ulcer prevention.

    Science.gov (United States)

    Yeung, Ching-Yan C; Holmes, David F; Thomason, Helen A; Stephenson, Christian; Derby, Brian; Hardman, Matthew J

    2016-11-01

    Pressure ulcers are complex wounds caused by pressure- and shear-induced trauma to skin and underlying tissues. Pressure-reducing devices, such as dressings, have been shown to successfully reduce pressure ulcer incidence, when used in adjunct to pressure ulcer preventative care. While pressure-reducing devices are available in a range of materials, with differing mechanical properties, understanding of how a material's mechanical properties will influence clinical efficacy remains limited. The aim of this study was to establish a standardized ex vivo model to allow comparison of the cell protection potential of two gel-like pressure-reducing devices with differing mechanical properties (elastic moduli of 77 vs. 35 kPa). The devices also displayed differing energy dissipation under compressive loading, and resisted strain differently under constant load in compressive creep tests. To evaluate biological efficacy we employed a new ex vivo porcine skin model, with a confirmed elastic moduli closely matching that of human skin (113 vs. 119 kPa, respectively). Static loads up to 20 kPa were applied to porcine skin ex vivo with subsequent evaluation of pressure-induced cell death and cytokine release. Pressure application alone increased the percentage of epidermal apoptotic cells from less than 2% to over 40%, and increased cellular secretion of the pro-inflammatory cytokine TNF-alpha. Co-application of a pressure-reducing device significantly reduced both cellular apoptosis and cytokine production, protecting against cellular damage. These data reveal new insight into the relationship between mechanical properties of pressure-reducing devices and their biological effects. After appropriate validation of these results in clinical pressure ulcer prevention with all tissue layers present between the bony prominence and external surface, this ex vivo porcine skin model could be widely employed to optimize design and evaluation of devices aimed at reducing pressure

  18. Imaging and Pathological Features of Percutaneous Cryosurgery on Normal Lung Evaluated in a Porcine Model

    Directory of Open Access Journals (Sweden)

    Lizhi NIU

    2010-07-01

    Full Text Available Background and objective Lung cancer is one of the most commonly occurring malignancies and frequent causes of death in the world. Cryoablation is a safe and alternative treatment for unresectable lung cancer. Due to the lung being gas-containing organ and different from solid organs such as liver and pancreas, it is difficult to achieve the freezing range of beyond the tumor edge 1 cm safety border. The aim of this study is to examine the effect of different numbers of freeze cycles on the effectiveness of cryoablation on normal lung tissue and to create an operation guideline that gives the best effect. Methods Six healthy Tibetan miniature pigs were given a CT scan and histological investigation after percutaneous cryosurgery. Cryoablation was performed as 2 cycles of 10 min of active freezing in the left lung; each freeze followed by a 5 min thaw. In the right lung, we performed the same 2 cycles of 5 min of freezing followed by 5 min of thawing. However, for the right lung, we included a third cycle of consisting of 10 min of freezing followed by 5 min of thawing. Three cryoprobes were inserted into the left lung and three cryoprobes in the right lung per animal, one in the upper and two in the lower lobe, so as to be well away from each other. Comparison under the same experimental condition was necessary. During the experiment, observations were made regarding the imaging change of ice-ball. The lungs were removed postoperatively at 3 intervals: 4 h, 3 d of postoperation and 7 d of postoperation, respectively, to view microscopic and pathological change. Results The ice-ball grew gradually in relation to the increase in time, and the increase in number of cycles. The size of the cryolesion (hypothesis necrotic area in specimens, over time, became larger in size than the size of the ice-ball during operation, regardless of whether 2 or 3 freeze-thaw cycles were performed. The area of necrosis was gradually increased over the course of time

  19. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    BackgroundA large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. Methods10 pigs...

  20. Liver BCATm transgenic mouse model reveals the important role of the liver in maintaining BCAA homeostasis.

    Science.gov (United States)

    Ananieva, Elitsa A; Van Horn, Cynthia G; Jones, Meghan R; Hutson, Susan M

    2017-02-01

    Unlike other amino acids, the branched-chain amino acids (BCAAs) largely bypass first-pass liver degradation due to a lack of hepatocyte expression of the mitochondrial branched-chain aminotransferase (BCATm). This sets up interorgan shuttling of BCAAs and liver-skeletal muscle cooperation in BCAA catabolism. To explore whether complete liver catabolism of BCAAs may impact BCAA shuttling in peripheral tissues, the BCATm gene was stably introduced into mouse liver. Two transgenic mouse lines with low and high hepatocyte expression of the BCATm transgene (LivTg-LE and LivTg-HE) were created and used to measure liver and plasma amino acid concentrations and determine whether the first two BCAA enzymatic steps in liver, skeletal muscle, heart and kidney were impacted. Expression of the hepatic BCATm transgene lowered the concentrations of hepatic BCAAs while enhancing the concentrations of some nonessential amino acids. Extrahepatic BCAA metabolic enzymes and plasma amino acids were largely unaffected, and no growth rate or body composition differences were observed in the transgenic animals as compared to wild-type mice. Feeding the transgenic animals a high-fat diet did not reverse the effect of the BCATm transgene on the hepatic BCAA catabolism, nor did the high-fat diet cause elevation in plasma BCAAs. However, the high-fat-diet-fed BCATm transgenic animals experienced attenuation in the mammalian target of rapamycin (mTOR) pathway in the liver and had impaired blood glucose tolerance. These results suggest that complete liver BCAA metabolism influences the regulation of glucose utilization during diet-induced obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Hepatocyte Hypoxia Inducible Factor-1 Mediates the Development of Liver Fibrosis in a Mouse Model of Nonalcoholic Fatty Liver Disease.

    Directory of Open Access Journals (Sweden)

    Omar A Mesarwi

    Full Text Available Obstructive sleep apnea (OSA is associated with the progression of non-alcoholic fatty liver disease (NAFLD to steatohepatitis and fibrosis. This progression correlates with the severity of OSA-associated hypoxia. In mice with diet induced obesity, hepatic steatosis leads to liver tissue hypoxia, which worsens with exposure to intermittent hypoxia. Emerging data has implicated hepatocyte cell signaling as an important factor in hepatic fibrogenesis. We hypothesized that hepatocyte specific knockout of the oxygen sensing α subunit of hypoxia inducible factor-1 (HIF-1, a master regulator of the global response to hypoxia, may be protective against the development of liver fibrosis.Wild-type mice and mice with hepatocyte-specific HIF-1α knockout (Hif1a-/-hep were fed a high trans-fat diet for six months, as a model of NAFLD. Hepatic fibrosis was evaluated by Sirius red stain and hydroxyproline assay. Liver enzymes, fasting insulin, and hepatic triglyceride content were also assessed. Hepatocytes were isolated from Hif1a-/-hep mice and wild-type controls and were exposed to sustained hypoxia (1% O2 or normoxia (16% O2 for 24 hours. The culture media was used to reconstitute type I collagen and the resulting matrices were examined for collagen cross-linking.Wild-type mice on a high trans-fat diet had 80% more hepatic collagen than Hif1a-/-hep mice (2.21 μg collagen/mg liver tissue, versus 1.23 μg collagen/mg liver tissue, p = 0.03, which was confirmed by Sirius red staining. Body weight, liver weight, mean hepatic triglyceride content, and fasting insulin were similar between groups. Culture media from wild-type mouse hepatocytes exposed to hypoxia allowed for avid collagen cross-linking, but very little cross-linking was seen when hepatocytes were exposed to normoxia, or when hepatocytes from Hif1a-/-hep mice were used in hypoxia or normoxia.Hepatocyte HIF-1 mediates an increase in liver fibrosis in a mouse model of NAFLD, perhaps due to liver

  2. A simple method to approximate liver size on cross-sectional images using living liver models

    International Nuclear Information System (INIS)

    Muggli, D.; Mueller, M.A.; Karlo, C.; Fornaro, J.; Marincek, B.; Frauenfelder, T.

    2009-01-01

    Aim: To assess whether a simple. diameter-based formula applicable to cross-sectional images can be used to calculate the total liver volume. Materials and methods: On 119 cross-sectional examinations (62 computed tomography and 57 magnetic resonance imaging) a simple, formula-based method to approximate the liver volume was evaluated. The total liver volume was approximated measuring the largest craniocaudal (cc), ventrodorsal (vd), and coronal (cor) diameters by two readers and implementing the equation: Vol estimated =ccxvdxcorx0.31. Inter-rater reliability, agreement, and correlation between liver volume calculation and virtual liver volumetry were analysed. Results: No significant disagreement between the two readers was found. The formula correlated significantly with the volumetric data (r > 0.85, p < 0.0001). In 81% of cases the error of the approximated volume was <10% and in 92% of cases <15% compared to the volumetric data. Conclusion: Total liver volume can be accurately estimated on cross-sectional images using a simple, diameter-based equation.

  3. Improvement of specific growth rate of Pichia pastoris for effective porcine interferon-α production with an on-line model-based glycerol feeding strategy.

    Science.gov (United States)

    Gao, Min-Jie; Zheng, Zhi-Yong; Wu, Jian-Rong; Dong, Shi-Juan; Li, Zhen; Jin, Hu; Zhan, Xiao-Bei; Lin, Chi-Chung

    2012-02-01

    Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor. The influence of the glycerol feeding strategy on the specific growth rate and protein production was investigated. The traditional DO-stat feeding strategy led to very low cell growth rate resulting in low dry cell weight (DCW) of about 90 g/L during the subsequent induction phase. The previously reported Artificial Neural Network Pattern Recognition (ANNPR) model-based glycerol feeding strategy improved the cell density to 120 g DCW/L, while the specific growth rate decreased from 0.15 to 0.18 to 0.03-0.08 h(-1) during the last 10 h of the glycerol feeding stage leading to a variation of the porcine interferon-α production, as the glycerol feeding scheme had a significant effect on the induction phase. This problem was resolved by an improved ANNPR model-based feeding strategy to maintain the specific growth rate above 0.11 h(-1). With this feeding strategy, the pIFN-α concentration reached a level of 1.43 g/L, more than 1.5-fold higher than that obtained with the previously adopted feeding strategy. Our results showed that increasing the specific growth rate favored the target protein production and the glycerol feeding methods directly influenced the induction stage. Consequently, higher cell density and specific growth rate as well as effective porcine interferon-α production have been achieved by our novel glycerol feeding strategy.

  4. Precision-cut liver slices as a model for the early onset of liver fibrosis to test antifibrotic drugs

    NARCIS (Netherlands)

    Westra, Inge M.; Oosterhuis, Dorenda; Groothuis, Geny M. M.; Olinga, Peter

    2014-01-01

    Induction of fibrosis during prolonged culture of precision-cut liver slices (PCLS) was reported. In this study, the use of rat PCLS was investigated to further characterize the mechanism of early onset of fibrosis in this model and the effects of antifibrotic compounds. Rat PCLS were incubated for

  5. Development and validation of a viscoelastic and nonlinear liver model for needle insertion

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Yo [Waseda University, Consolidated Research Institute for Advanced Science and Medical Care, Shinjuku, Tokyo (Japan); Onishi, Akinori; Hoshi, Takeharu; Kawamura, Kazuya [Waseda University, Graduate School of Science and Engineering, Shinjuku (Japan); Hashizume, Makoto [Kyushu University Hospital, Center for the Integration of Advanced Medicine and Innovative Technology, Fukuoka (Japan); Fujie, Masakatsu G. [Waseda University, Graduate School of Science and Engineering, Faculty of Science and Engineering, Shinjuku (Japan)

    2009-01-15

    The objective of our work is to develop and validate a viscoelastic and nonlinear physical liver model for organ model-based needle insertion, in which the deformation of an organ is estimated and predicted, and the needle path is determined with organ deformation taken into consideration. First, an overview is given of the development of the physical liver model. The material properties of the liver considering viscoelasticity and nonlinearity are modeled based on the measured data collected from a pig's liver. The method to develop the liver model using FEM is also shown. Second, the experimental method to validate the model is explained. Both in vitro and in vivo experiments that made use of a pig's liver were conducted for comparison with the simulation using the model. Results of the in vitro experiment showed that the model reproduces nonlinear and viscoelastic response of displacement at an internally located point with high accuracy. For a force up to 0.45 N, the maximum error is below 1 mm. Results of the in vivo experiment showed that the model reproduces the nonlinear increase of load upon the needle during insertion. Based on these results, the liver model developed and validated in this work reproduces the physical response of a liver in both in vitro and in vivo situations. (orig.)

  6. Evaluation of a novel cryoballoon swipe ablation system in bench, porcine, and human esophagus models

    NARCIS (Netherlands)

    Louie, B. E.; Hofstetter, W.; Triadafilopoulos, G.; Weusten, B. L.

    2018-01-01

    Current ablation devices for dysplastic Barrett's esophagus are effective but have significant limitations. This pilot study aims to evaluate the safety, feasibility, and dose response of a novel cryoballoon swipe ablation system (CbSAS) in three experimental in vitro and in vivo models. CbSAS is a

  7. Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes

    DEFF Research Database (Denmark)

    Che, Brita Ngum; Oksbjerg, Niels; Hellgren, Lars

    2013-01-01

    and tritiated 2-deoxyglucose (2-DOG) was used to measure glucose uptake, in relation to PA and 2-DOG exposure times and also in relation to PA and insulin concentrations. The MIXED procedure model of SAS was used for statistical analysis of data. RESULTS: PA increased glucose uptake by approximately 35...

  8. Establishing a Reproducible Hypertrophic Scar following Thermal Injury: A Porcine Model

    Directory of Open Access Journals (Sweden)

    Scott J. Rapp, MD

    2015-02-01

    Conclusions: Deep partial-thickness thermal injury to the back of domestic swine produces an immature hypertrophic scar by 10 weeks following burn with thickness appearing to coincide with the location along the dorsal axis. With minimal pig to pig variation, we describe our technique to provide a testable immature scar model.

  9. Therapy of haematogenous osteomyelitis--a comparative study in a porcine model and Angolan children

    DEFF Research Database (Denmark)

    Johansen, Maria Louise; Koch, Janne; Kirketerp-Møller, Klaus

    2013-01-01

    It is generally accepted that surgery is necessary for the proper treatment of chronic haematogenous osteomyelitis (HO) in children. However, the correct timing of surgery and the technique most effective for debridement of infectious bone tissue is debated. Theoretically, large animal models of HO...

  10. Anti-colchicine Fab fragments prevent lethal colchicine toxicity in a porcine model: a pharmacokinetic and clinical study.

    Science.gov (United States)

    Eddleston, Michael; Fabresse, Nicolas; Thompson, Adrian; Al Abdulla, Ibrahim; Gregson, Rachael; King, Tim; Astier, Alain; Baud, Frederic J; Clutton, R Eddie; Alvarez, Jean-Claude

    2018-08-01

    Colchicine poisoning is commonly lethal. Colchicine-specific Fab fragments increase rat urinary colchicine clearance and have been associated with a good outcome in one patient. We aimed to develop a porcine model of colchicine toxicity to study the pharmacokinetics and efficacy of ovine Fab. A Göttingen minipig critical care model was established and serial blood samples taken for colchicine and Fab pharmacokinetics, clinical chemistry, and haematology. Animals were euthanised when the mean arterial pressure fell below 45 mmHg without response to vasopressor, or at study completion. Initial studies indicated that oral dosing produced variable pharmacokinetics and time-to-euthanasia. By contrast, intravenous infusion of 0.25 mg/kg colchicine over 1 h produced reproducible pharmacokinetics (AUC 0-20 343 [SD = 21] µg/L/h), acute multi-organ injury, and cardiotoxicity requiring euthanasia a mean of 22.5 (SD = 3.2) h after dosing. A full-neutralising equimolar Fab dose given 6 h after the infusion (50% first hour, 50% next 6 h [to reduce renal-loss of unbound Fab]) produced a 7.35-fold increase in plasma colchicine (AUC 0-20 2,522 [SD = 14] µg/L/h), and removed all free plasma colchicine, but did not prevent toxicity (euthanasia at 29.1 [SD = 3.4] h). Earlier administration over 1 h of the full-neutralising dose, 1 or 3 h after the colchicine, produced a 12.9-fold (AUC 0-20 4,433 [SD = 607] µg/L/h) and 6.0-fold (AUC 0-20 2,047 [SD = 51] µg/L/h) increase in plasma colchicine, respectively, absence of free plasma colchicine until 20 h, and survival to study end without marked cardiotoxicity. Colchicine-specific Fab given early, in equimolar dose, bound colchicine, eliciting its movement into the blood, and preventing severe toxicity. Clinical studies are now needed to determine how soon this antidote must be given to work in human poisoning.

  11. A comparison of micropore membrane inlet mass spectrometry-derived pulmonary shunt measurement with Riley shunt in a porcine model.

    Science.gov (United States)

    Duenges, Bastian; Vogt, Andreas; Bodenstein, Marc; Wang, Hemei; Böhme, Stefan; Röhrig, Bernd; Baumgardner, James E; Markstaller, Klaus

    2009-12-01

    The multiple inert gas elimination technique was developed to measure shunt and the ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung (V(A)'/Q') distributions. Micropore membrane inlet mass spectrometry (MMIMS), instead of gas chromatography, has been introduced for inert gas measurement and shunt determination in a rabbit lung model. However, agreement with a frequently used and accepted method for quantifying deficits in arterial oxygenation has not been established. We compared MMIMS-derived shunt (M-S) as a fraction of total cardiac output (CO) with Riley shunt (R-S) derived from the R-S formula in a porcine lung injury model. To allow a broad variance of atelectasis and therefore shunt fraction, 8 sham animals did not receive lavage, and 8 animals were treated by lung lavages with 30 mL/kg warmed lactated Ringer's solution as follows: 2 animals were lavaged once, 5 animals twice, and 1 animal 3 times. Variables were recorded at baseline and twice after induction of lung injury (T1 and T2). Retention data of sulfur hexafluoride, krypton, desflurane, enflurane, diethyl ether, and acetone were analyzed by MMIMS, and M-S was derived using a known algorithm for the multiple inert gas elimination technique. Standard formulas were used for the calculation of R-S. Forty-four pairs of M-S and R-S were recorded. M-S ranged from 0.1% to 35.4% and R-S from 3.7% to 62.1%. M-S showed a correlation with R-S described by linear regression: M-S = -4.26 + 0.59 x R-S (r(2) = 0.83). M-S was on average lower than R-S (mean = -15.0% CO, sd = 6.5% CO, and median = -15.1), with lower and upper limits of agreement of -28.0% and -2.0%, respectively. The lower and upper limits of the 95% confidence intervals were -17.0 and -13.1 (P < 0.001, Student's t-test). Shunt derived from MMIMS inert gas retention data correlated well with R-S during breathing of oxygen. Shunt as derived by MMIMS was generally less than R-S.

  12. Pharmacological targeting of chemokine (C-X-C motif) receptor 4 in porcine polytrauma and hemorrhage models

    Science.gov (United States)

    Bach, Harold H.; Wong, Yee M.; LaPorte, Heather M.; Gamelli, Richard L.; Majetschak, Matthias

    2016-01-01

    BACKGROUND Recent evidence suggests that chemokine receptor CXCR4 regulates vascular α1-adrenergic receptor function and that the noncognate CXCR4 agonist ubiquitin has therapeutic potential after trauma/hemorrhage. Pharmacologic properties of ubiquitin in large animal trauma models, however, are poorly characterized. Thus, the aims of the present study were to determine the effects of CXCR4 modulation on resuscitation requirements after polytrauma, to assess whether ubiquitin influences survival times after lethal polytrauma-hemorrhage, and to characterize its dose-effect profile in porcine models. METHODS Anesthetized pigs underwent polytrauma (PT, femur fractures/lung contusion) alone (Series 1) or PT/hemorrhage (PT/H) to a mean arterial blood pressure of 30 mmHg with subsequent fluid resuscitation (Series 2 and 3) or 40% blood volume hemorrhage within 15 minutes followed by 2.5% blood volume hemorrhage every 15 minutes without fluid resuscitation (Series 4). In Series 1, ubiquitin (175 and 350 nmol/kg), AMD3100 (CXCR4 antagonist, 350 nmol/kg), or vehicle treatment 60 minutes after PT was performed. In Series 2, ubiquitin (175, 875, and 1,750 nmol/kg) or vehicle treatment 60 minutes after PT/H was performed. In Series 3, ubiquitin (175 and 875 nmol/kg) or vehicle treatment at 60 and 180 minutes after PT/H was performed. In Series 4, ubiquitin (875 nmol/kg) or vehicle treatment 30 minutes after hemorrhage was performed. RESULTS In Series 1, resuscitation fluid requirements were significantly reduced by 40% with 350-nmol/kg ubiquitin and increased by 25% with AMD3100. In Series 2, median survival time was 190 minutes with vehicle, 260 minutes with 175-nmol/kg ubiquitin, and longer than 420 minutes with 875-nmol/kg and 1,750-nmol/kg ubiquitin (p 0.05). CONCLUSION These findings further suggest CXCR4 as a drug target after PT/H. Ubiquitin treatment reduces resuscitation fluid requirements and provides survival benefits after PT/H. The pharmacological effects of

  13. Strategies, models and biomarkers in experimental non-alcoholic fatty liver disease research

    Science.gov (United States)

    Willebrords, Joost; Pereira, Isabel Veloso Alves; Maes, Michaël; Yanguas, Sara Crespo; Colle, Isabelle; Van Den Bossche, Bert; Da silva, Tereza Cristina; Oliveira, Cláudia P; Andraus, Wellington; Alves, Venâncio Avancini Ferreira; Cogliati, Bruno; Vinken, Mathieu

    2015-01-01

    Non-alcoholic fatty liver disease encompasses a spectrum of liver diseases, including simple steatosis, steatohepatitis, liver fibrosis and cirrhosis and hepatocellular carcinoma. Non-alcoholic fatty liver disease is currently the most dominant chronic liver disease in Western countries due to the fact that hepatic steatosis is associated with insulin resistance, type 2 diabetes mellitus, obesity, metabolic syndrome and drug-induced injury. A variety of chemicals, mainly drugs, and diets is known to cause hepatic steatosis in humans and rodents. Experimental non-alcoholic fatty liver disease models rely on the application of a diet or the administration of drugs to laboratory animals or the exposure of hepatic cell lines to these drugs. More recently, genetically modified rodents or zebrafish have been introduced as non-alcoholic fatty liver disease models. Considerable interest now lies in the discovery and development of novel non-invasive biomarkers of non-alcoholic fatty liver disease, with specific focus on hepatic steatosis. Experimental diagnostic biomarkers of non-alcoholic fatty liver disease, such as (epi)genetic parameters and ‘-omics’-based read-outs are still in their infancy, but show great promise. . In this paper, the array of tools and models for the study of liver steatosis is discussed. Furthermore, the current state-of-art regarding experimental biomarkers such as epigenetic, genetic, transcriptomic, proteomic and metabonomic biomarkers will be reviewed. PMID:26073454

  14. Development of experimental fibrotic liver diseases animal model by Carbon Tetracholoride.

    Science.gov (United States)

    Gitiara, Atoosa; Tokhanbigli, Samaneh; Mazhari, Sogol; Baghaei, Kaveh; Hatami, Behzad; Hashemi, Seyed Mahmoud; Asadi Rad, Ali; Moradi, Afshin; Nasiri, Meyam; Zarrabi Ahrabi, Nakisa; Zali, Mohammad Reza

    2017-01-01

    This study is presenting an effective method of inducing liver fibrosis by CCL4 as a toxin in two different breeds of rat models. Liver fibrosis is a result of inflammation and liver injury caused by wound healing responses which ultimately lead to liver failure. Consequently, after liver fibrosis, the progression will be continued to liver cirrhosis and at the end stage hepatocellular carcinoma (HCC). Many studies have demonstrated that one of the most important causes of liver fibrosis is Non-alcoholic steatohepatitis (NASH). Fibrotic Liver is affected by an excessive accumulation of extracellular matrix (ECM) proteins like collagen and α-SMA. In two different experiments, male Vistar, and Sprague Dawley Rat models ranging from 200±60, corresponding to an age of approximately 10 weeks were utilized in order to induce CCL4 treated liver fibrosis. After 6 weeks of CCL4 injection, different tests have been carried out to verify the liver fibrosis including serum markers such as Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT), molecular tests containing, laminin and α-SMA and also pathological observation by Hematoxylin and eosin staining in both fibrosis and control group. The results of Pathology and Real-time PCR showed that fibrosis was induced much more effectively in Sprague Dawley rat model compared with Wistar rats.

  15. Lyman NTCP model analysis of radiation-induced liver disease in hypofractionated conformal radiotherapy for primary liver carcinoma

    International Nuclear Information System (INIS)

    Xu Zhiyong; Zhu Yi; Zhao Jiaodong; Fu Xiaolong; Jiang Guoliang; Liang Shixiong; Zhu Xiaodong

    2006-01-01

    Objective: To identify the factors associated with radiation-induced liver disease (RILD) and to describe the probability of RILD using the Lyman normal tissue complication(NTCP) model for primary liver carcinoma(PLC) treated with hypofractionated conformal therapy (CRT). Methods: A total of 109 PLC patients treated with hypofractionated CRT were prospectively followed according to the Child-Pugh classification for liver cirrhosis, 93 patients in class A and 16 in class B. The mean dose of radiation to the isocenter was (53.5±5.5) Gy, fractions of (4.8±0.5) Gy, with interfraction interval of 48 hours and irradiation 3 times per week. Maximal likelihood analysis yielded the best estimates of parameters of the Lyman NTCP model for all patients; Child-Pugh A and Child-Pugh B patients, respectively. Results: Of all the patients, 17 developed RILD (17/109), 8 in Child-Pugh A (8/93) and 9 in Child-Pugh B (9/16). By multivariate analysis, only the Child-Pugh Grade of liver cirrhosis was the independent factor (P=0.000) associated with the developing of BILD. The best estimates of the NTCP parameters for all 109 patients were n=1.1, m=0.35 and TD 50 (1)=38.5 Gy. The n, m, TD 50 (1) estimated from patients with Child-Pugh A was 1.1, 0.28, 40.5 Gy, respectively, compared with 0.7, 0.43, 23 Gy respectively, for patients with Child-Pugh B. Conclusions: Primary liver cancer patients who possess Child-Pugh B cirrhosis would present a significantly greater susceptibility to RILD after hypofractionated CRT than patients with Child-Pugh A cirrhosis. The predominant risk factor for developing RILD is the severity of hepatic cirrhosis in the liver of PLC patients. (authors)

  16. Porcine models for the study of local and systemic regulation of innate immune factors in obesity

    DEFF Research Database (Denmark)

    Højbøge, Tina Rødgaard

    state of low-grade inflammation in the adipose tissues, which involves several factors of the innate immune response having a range of systemic effects and which has been implicated in the development of the metabolic syndrome. To investigate the impact of obesity and obesity-related diseases good...... translational animal models are needed, and as such pigs have been proposed as relevant models for human obesity-induced inflammation as pigs share many genetic, anatomical and physiological features with humans. In this project the up- and downregulation of genes and proteins involved in the innate immune...... the number of animals to be used in a trial to obtain statistical power. For the gene regulation analysis, two platforms for quantitative real-time PCR (qPCR) were employed: The Rotor-Gene Q instrument and the microfluidics-based high-throughput Bio-Mark. For the serum protein concentrations analysis several...

  17. Malignant infarction of the middle cerebral artery in a porcine model. A pilot study.

    Directory of Open Access Journals (Sweden)

    Fuat Arikan

    Full Text Available Interspecies variability and poor clinical translation from rodent studies indicate that large gyrencephalic animal stroke models are urgently needed. We present a proof-of-principle study describing an alternative animal model of malignant infarction of the middle cerebral artery (MCA in the common pig and illustrate some of its potential applications. We report on metabolic patterns, ionic profile, brain partial pressure of oxygen (PtiO2, expression of sulfonylurea receptor 1 (SUR1, and the transient receptor potential melastatin 4 (TRPM4.A 5-hour ischemic infarct of the MCA territory was performed in 5 2.5-to-3-month-old female hybrid pigs (Large White x Landrace using a frontotemporal approach. The core and penumbra areas were intraoperatively monitored to determine the metabolic and ionic profiles. To determine the infarct volume, 2,3,5-triphenyltetrazolium chloride staining and immunohistochemistry analysis was performed to determine SUR1 and TRPM4 expression.PtiO2 monitoring showed an abrupt reduction in values close to 0 mmHg after MCA occlusion in the core area. Hourly cerebral microdialysis showed that the infarcted tissue was characterized by reduced concentrations of glucose (0.03 mM and pyruvate (0.003 mM and increases in lactate levels (8.87mM, lactate-pyruvate ratio (4202, glycerol levels (588 μM, and potassium concentration (27.9 mmol/L. Immunohistochemical analysis showed increased expression of SUR1-TRPM4 channels.The aim of the present proof-of-principle study was to document the feasibility of a large animal model of malignant MCA infarction by performing transcranial occlusion of the MCA in the common pig, as an alternative to lisencephalic animals. This model may be useful for detailed studies of cerebral ischemia mechanisms and the development of neuroprotective strategies.

  18. Clinical and histological findings after intravitreal injection of bevacizumab (Avastin) in a porcine model of choroidal neovascularization

    DEFF Research Database (Denmark)

    Lassota, Nathan; Prause, Jan Ulrik; Scherfig, Erik

    2010-01-01

    PURPOSE: To examine the effect of intravitreally injected bevacizumab (Avastin) on the histological and angiographic morphology of choroidal neovascularization (CNV) in a masked and placebo-controlled animal study. METHODS: Choroidal neovascularization was induced surgically in 11 porcine eyes by...... these membranes. After a single injection, bevacizumab did not exhibit a size reducing effect on CNV, but it was still present in the membranes 14 days after intravitreal injection....

  19. Biophysical model for thorotrast-induced liver cancers

    International Nuclear Information System (INIS)

    Noesterer, M; Hofmann, W.; Andreev, S.G.

    1996-01-01

    In Germany between 1930 and 1950, an estimated 10,000 to 20,000 patients received Thorostrast injections, mostly for angiographic examinations. About 59% of the intravascularly injected Thorotrast was retained by the liver. Based on a mean injected volume of 25 ml and an average exposure time of about 40 years, Thorotrast patients received a mean liver dose of about 9.5 Gy. As a consequence, about 20% of the 2,326 Thorotrast patients examined in the German Thorotrast Study died of liver tumors, while only 2 cases of primary liver tumors were observed in the 1,890 control patients

  20. A Pharmacodynamic Analysis of Choroidal Neovascularization in a Porcine Model Using Three Targeted Drugs

    Science.gov (United States)

    Tran, Jeffrey; Craven, Caroline; Wabner, Kathy; Schmit, Jenn; Matter, Brock; Kompella, Uday; Grossniklaus, Hans E.; Olsen, Timothy W.

    2017-01-01

    Purpose To compare the efficacy of microneedle-delivered suprachoroidal (SC) pazopanib to intravitreal (Ivit) delivery of pazopanib, bevacizumab, or a fusion protein hI-con1 versus vehicle controls on choroidal neovascularization (CNV) growth in a pig model. Methods Forty-one pigs were injected on the day of CNV induction (hI-con1 on postinduction day 14) with either 2.5 mg Ivit bevacizumab (n = 9), 1 mg Ivit pazopanib (n = 9), 300 Ivit μg hI-con1 (n = 4), or 1 mg SC pazopanib (n = 9), vs. 10 vehicle controls (3 SC + 7 Ivit = 10). Pigs were euthanized at week 2 (11), 3 (8), 4 (11), and 8 (11), and eyes were fixed for histology. The size of the CNV was determined from histology, and CNV height was the primary outcome measure. Immunostaining for cytotoxic T-cells was performed in the hI-con1 study. Results In 39 of 41 (95%) eyes, type 2 CNV lesions were identified. One CNV lesion was lost during dissection. One animal was euthanized due to surgical complications. For mean CNV size comparisons, Ivit pazopanib had smaller mean height measurements (90 ± 20 μm) versus controls (180 ± 20 μm; P = 0.009), and Ivit pazopanib had smaller maximum CNV height (173 ± 43 μm) compared to SC pazopanib (478 ± 105 μm; P = 0.018). The mean lesion size in hI-con1–treated animals trended smaller than in controls (P = 0.11). Immunostaining did not detect cytotoxic T-cells. Conclusions Intravitreal pazopanib and to a lesser extent hI-con1 reduced the size of CNV lesions. The pig model has nearly a 100% rate of type 2 CNV induction and is a reliable preclinical model with pharmacodynamics similar to humans. PMID:28738417

  1. Epicardial shock-wave therapy improves ventricular function in a porcine model of ischaemic heart disease.

    Science.gov (United States)

    Holfeld, Johannes; Zimpfer, Daniel; Albrecht-Schgoer, Karin; Stojadinovic, Alexander; Paulus, Patrick; Dumfarth, Julia; Thomas, Anita; Lobenwein, Daniela; Tepeköylü, Can; Rosenhek, Raphael; Schaden, Wolfgang; Kirchmair, Rudolf; Aharinejad, Seyedhossein; Grimm, Michael

    2016-12-01

    Previously we have shown that epicardial shock-wave therapy improves left ventricular ejection fraction (LVEF) in a rat model of myocardial infarction. In the present experiments we aimed to address the safety and efficacy of epicardial shock-wave therapy in a preclinical large animal model and to further evaluate mechanisms of action of this novel therapy. Four weeks after left anterior descending (LAD) artery ligation in pigs, the animals underwent re-thoracotomy with (shock-wave group, n = 6) or without (control group, n = 5) epicardial shock waves (300 impulses at 0.38 mJ/mm 2 ) applied to the infarcted anterior wall. Efficacy endpoints were improvement of LVEF and induction of angiogenesis 6 weeks after shock-wave therapy. Safety endpoints were haemodynamic stability during treatment and myocardial damage. Four weeks after LAD ligation, LVEF decreased in both the shock-wave (43 ± 3%, p wave animals 6 weeks after treatment (62 ± 9%, p = 0.006); no improvement was observed in controls (41 ± 4%, p = 0.36), yielding a significant difference. Quantitative histology revealed significant angiogenesis 6 weeks after treatment (controls 2 ± 0.4 arterioles/high-power field vs treatment group 9 ± 3; p = 0.004). No acute or chronic adverse effects were observed. As a potential mechanism of action in vitro experiments showed stimulation of VEGF receptors after shock-wave treatment in human coronary artery endothelial cells. Epicardial shock-wave treatment in a large animal model of ischaemic heart failure exerted a positive effect on LVEF improvement and did not show any adverse effects. Angiogenesis was induced by stimulation of VEGF receptors. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  2. A novel, comprehensive, and reproducible porcine model for determining the timing of bruises in forensic pathology

    DEFF Research Database (Denmark)

    Barington, Kristiane; Jensen, Henrik Elvang

    2016-01-01

    Purpose Calculating the timing of bruises is crucial in forensic pathology but is a challenging discipline in both human and veterinary medicine. A mechanical device for inflicting bruises in pigs was developed and validated, and the pathological reactions in the bruises were studied over time......-dependent response. Combining these parameters, bruises could be grouped as being either less than 4 h old or between 4 and 10 h of age. Gross lesions and changes in the epidermis and dermis were inconclusive with respect to time determination. Conclusions The model was reproducible and resembled forensic cases...

  3. Long-Term Adult Feline Liver Organoid Cultures for Disease Modeling of Hepatic Steatosis

    NARCIS (Netherlands)

    Kruitwagen, Hedwig S.; Oosterhoff, Loes A.; Vernooij, Ingrid G.W.H.; Schrall, Ingrid M.; van Wolferen, Monique E.; Bannink, Farah; Roesch, Camille; van Uden, Lisa; Molenaar, Martijn R.; Helms, J. Bernd; Grinwis, Guy C.M.; Verstegen, Monique M.A.; van der Laan, Luc J.W.; Huch, Meritxell; Geijsen, Niels; Vries, Robert G.; Clevers, Hans; Rothuizen, Jan; Schotanus, Baukje A.; Penning, Louis C.; Spee, Bart

    2017-01-01

    Hepatic steatosis is a highly prevalent liver disease, yet research is hampered by the lack of tractable cellular and animal models. Steatosis also occurs in cats, where it can cause severe hepatic failure. Previous studies demonstrate the potential of liver organoids for modeling genetic diseases.

  4. Long-Term Adult Feline Liver Organoid Cultures for Disease Modeling of Hepatic Steatosis

    NARCIS (Netherlands)

    Kruitwagen, H.S. (Hedwig S.); Oosterhoff, L.A. (Loes A.); Vernooij, I.G.W.H. (Ingrid G.W.H.); Schrall, I.M. (Ingrid M.); M.E. van Wolferen (Monique); Bannink, F. (Farah); Roesch, C. (Camille); van Uden, L. (Lisa); Molenaar, M.R. (Martijn R.); J.B. Helms (J. Bernd); G.C.M. Grinwis (Guy C.); M.M.A. Verstegen (Monique); L.J.W. van der Laan (Luc); M. Huch (Meritxell); N. Geijsen (Niels); R.G.J. Vries (Robert); H.C. Clevers (Hans); J. Rothuizen (J.); B.A. Schotanus (Baukje A.); C. Penning (Corine); B. Spee (B.)

    2017-01-01

    textabstractHepatic steatosis is a highly prevalent liver disease, yet research is hampered by the lack of tractable cellular and animal models. Steatosis also occurs in cats, where it can cause severe hepatic failure. Previous studies demonstrate the potential of liver organoids for modeling

  5. The Effect Of Supraphysiologic Blood Pressure on Traumatic Brain Injury and Proximal Tissue Beds During Resuscitative Balloon Occlusion of the Aorta and Variable Aortic Control in a Porcine Model (Sus scrofa) of Polytrauma.

    Science.gov (United States)

    2017-04-27

    Control In A Porcine Model (Sus Scrofa) Of Polytrauma . PRINCIPAL INVESTIGATOR (PI) / TRAINING COORDINATOR (TC): Lt Col Timothy Williams DEPARTMENT...Mandatory) The Effect of REBOA, Partial Aortic Occlusion and Aggressive Blood Transfusion on Traumatic Brain Injury in a Swine Polytrauma Model

  6. Induction of continuous expanding infrarenal aortic aneurysms in a large porcine animal model

    DEFF Research Database (Denmark)

    Kloster, Brian Ozeraitis; Lund, Lars; Lindholt, Jes S.

    2015-01-01

    frequent complication was a neurological deficit in the lower limbs. ConclusionIn pigs it’s possible to induce continuous expanding AAA’s based upon proteolytic degradation and pathological flow, resembling the real life dynamics of human aneurysms. Because the lumbars are preserved, it’s also a potential......BackgroundA large animal model with a continuous expanding infrarenal aortic aneurysm gives access to a more realistic AAA model with anatomy and physiology similar to humans, and thus allows for new experimental research in the natural history and treatment options of the disease. Methods10 pigs......, hereafter the pigs were euthanized for inspection and AAA wall sampling for histological analysis. ResultsIn group A, all pigs developed continuous expanding AAA’s with a mean increase in AP-diameter to 16.26 ± 0.93 mm equivalent to a 57% increase. In group B the AP-diameters increased to 11.33 ± 0.13 mm...

  7. Low-intensity pulsed ultrasound induces angiogenesis and ameliorates left ventricular dysfunction in a porcine model of chronic myocardial ischemia.

    Directory of Open Access Journals (Sweden)

    Kenichiro Hanawa

    Full Text Available Although a significant progress has been made in the management of ischemic heart disease (IHD, the number of severe IHD patients is increasing. Thus, it is crucial to develop new, non-invasive therapeutic strategies. In the present study, we aimed to develop low-intensity pulsed ultrasound (LIPUS therapy for the treatment of IHD.We first confirmed that in cultured human endothelial cells, LIPUS significantly up-regulated mRNA expression of vascular endothelial growth factor (VEGF with a peak at 32-cycle (P<0.05. Then, we examined the in vivo effects of LIPUS in a porcine model of chronic myocardial ischemia with reduced left ventricular ejection fraction (LVEF (n = 28. The heart was treated with either sham (n = 14 or LIPUS (32-cycle with 193 mW/cm2 for 20 min, n = 14 at 3 different short axis levels. Four weeks after the treatment, LVEF was significantly improved in the LIPUS group (46±4 to 57±5%, P<0.05 without any adverse effects, whereas it remained unchanged in the sham group (46±5 to 47±6%, P = 0.33. Capillary density in the ischemic region was significantly increased in the LIPUS group compared with the control group (1084±175 vs. 858±151/mm2, P<0.05. Regional myocardial blood flow was also significantly improved in the LIPUS group (0.78±0.2 to 1.39±0.4 ml/min/g, P<0.05, but not in the control group (0.84±0.3 to 0.97±0.4 ml/min/g. Western blot analysis showed that VEGF, eNOS and bFGF were all significantly up-regulated only in the LIPUS group.These results suggest that the LIPUS therapy is promising as a new, non-invasive therapy for IHD.

  8. Dynamic myocardial perfusion in a porcine balloon-induced ischemia model using a prototype spectral detector CT

    Science.gov (United States)

    Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Levi, Jacob; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2015-03-01

    Myocardial CT perfusion (CTP) imaging is an application that should greatly benefit from spectral CT through the significant reduction of beam hardening (BH) artifacts using mono-energetic (monoE) image reconstructions. We used a prototype spectral detector CT (SDCT) scanner (Philips Healthcare) and developed advanced processing tools (registration, segmentation, and deconvolution-based flow estimation) for quantitative myocardial CTP in a porcine ischemia model with different degrees of coronary occlusion using a balloon catheter. The occlusion severity was adjusted with fractional flow reserve (FFR) measurements. The SDCT scanner is a single source, dual-layer detector system, which allows simultaneous acquisitions of low and high energy projections, hence enabling accurate projection-based material decomposition and effective reduction of BH-artifacts. In addition, the SDCT scanner eliminates partial scan artifacts with fast (0.27s), full gantry rotation acquisitions. We acquired CTP data under different hemodynamic conditions and reconstructed conventional 120kVp images and projection-based monoenergetic (monoE) images for energies ranging from 55keV-to-120keV. We computed and compared myocardial blood flow (MBF) between different reconstructions. With balloon completely deflated (FFR=1), we compared the mean attenuation in a myocardial region of interest before iodine arrival and at peak iodine enhancement in the left ventricle (LV), and we found that monoE images at 70keV effectively minimized the difference in attenuation, due to BH, to less than 1 HU compared to 14 HU with conventional 120kVp images. Flow maps under baseline condition (FFR=1) were more uniform throughout the myocardial wall at 70keV, whereas with 120kVp data about 12% reduction in blood flow was noticed on BH-hypoattenuated areas compared to other myocardial regions. We compared MBF maps at different keVs under an ischemic condition (FFR < 0.7), and we found that flow

  9. A Porcine Model for Initial Surge Mechanical Ventilator Assessment and Evaluation of Two Limited Function Ventilators

    Science.gov (United States)

    Dickson, Robert P; Hotchkin, David L; Lamm, Wayne JE; Hinkson, Carl; Pierson, David J; Glenny, Robb W; Rubinson, Lewis

    2013-01-01

    Objective To adapt an animal model of acute lung injury for use as a standard protocol for a screening, initial evaluation of limited function, or “surge,” ventilators for use in mass casualty scenarios. Design Prospective, experimental animal study. Setting University research laboratory. Subjects 12 adult pigs. Interventions 12 spontaneously breathing pigs (6 in each group) were subjected to acute lung injury/acute respiratory distress syndrome (ALI/ARDS) via pulmonary artery infusion of oleic acid. Following development of respiratory failure, animals were mechanically ventilated with a limited function ventilator (Simplified Automatic Ventilator [SAVe] I or II; Automedx) for one hour or until the ventilator could not support the animal. The limited function ventilator was then exchanged for a full function ventilator (Servo 900C; Siemens). Measurements and Main Results Reliable and reproducible levels of ALI/ARDS were induced. The SAVe I was unable to adequately oxygenate 5 animals, with PaO2 (52.0 ± 11.1 torr) compared to the Servo (106.0 ± 25.6 torr; p=0.002). The SAVe II was able to oxygenate and ventilate all 6 animals for one hour with no difference in PaO2 (141.8 ± 169.3 torr) compared to the Servo (158.3 ± 167.7 torr). Conclusions We describe a novel in vivo model of ALI/ARDS that can be used to initially screen limited function ventilators considered for mass respiratory failure stockpiles, and is intended to be combined with additional studies to defintively assess appropriateness for mass respiratory failure. Specifically, during this study we demonstrate that the SAVe I ventilator is unable to provide sufficient gas exchange, while the SAVe II, with several more functions, was able to support the same level of hypoxemic respiratory failure secondary to ALI/ARDS for one hour. PMID:21187747

  10. Reduced dose measurement of absolute myocardial blood flow using dynamic SPECT imaging in a porcine model

    International Nuclear Information System (INIS)

    Timmins, Rachel; Klein, Ran; Petryk, Julia; Marvin, Brian; Kemp, Robert A. de; Ruddy, Terrence D.; Wells, R. Glenn; Wei, Lihui

    2015-01-01

    Purpose: Absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements provide important additional information over traditional relative perfusion imaging. Recent advances in camera technology have made this possible with single-photon emission tomography (SPECT). Low dose protocols are desirable to reduce the patient radiation risk; however, increased noise may reduce the accuracy of MBF measurements. The authors studied the effect of reducing dose on the accuracy of dynamic SPECT MBF measurements. Methods: Nineteen 30–40 kg pigs were injected with 370 + 1110 MBq of Tc-99m sestamibi or tetrofosmin or 37 + 111 MBq of Tl-201 at rest + stress. Microspheres were injected simultaneously to measure MBF. The pigs were imaged in list-mode for 11 min starting at the time of injection using a Discovery NM 530c camera (GE Healthcare). Each list file was modified so that 3/4, 1/2, 1/4, 1/8, 1/16, and 1/32 of the original counts were included in the projections. Modified projections were reconstructed with CT-based attenuation correction and an energy window-based scatter correction and analyzed with FlowQuant kinetic modeling software using a 1-compartment model. A modified Renkin-Crone extraction function was used to convert the tracer uptake rate K1 to MBF values. The SPECT results were compared to those from microspheres. Results: Correlation between SPECT and microsphere MBF values for the full injected activity was r ≥ 0.75 for all 3 tracers and did not significantly degrade over all count levels. The mean MBF and MFR and the standard errors in the estimates were not significantly worse than the full-count data at 1/4-counts (Tc99m-tracers) and 1/2-counts (Tl-201). Conclusions: Dynamic SPECT measurement of MBF and MFR in pigs can be performed with 1/4 (Tc99m-tracers) or 1/2 (Tl-201) of the standard injected activity without significantly reducing accuracy and precision

  11. Reduced dose measurement of absolute myocardial blood flow using dynamic SPECT imaging in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Timmins, Rachel; Klein, Ran; Petryk, Julia; Marvin, Brian; Kemp, Robert A. de; Ruddy, Terrence D.; Wells, R. Glenn, E-mail: gwells@ottawaheart.ca [Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario K1Y4W7 (Canada); Wei, Lihui [Nordion, Inc., Ottawa, Ontario K2K 1X8 (Canada)

    2015-09-15

    Purpose: Absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) measurements provide important additional information over traditional relative perfusion imaging. Recent advances in camera technology have made this possible with single-photon emission tomography (SPECT). Low dose protocols are desirable to reduce the patient radiation risk; however, increased noise may reduce the accuracy of MBF measurements. The authors studied the effect of reducing dose on the accuracy of dynamic SPECT MBF measurements. Methods: Nineteen 30–40 kg pigs were injected with 370 + 1110 MBq of Tc-99m sestamibi or tetrofosmin or 37 + 111 MBq of Tl-201 at rest + stress. Microspheres were injected simultaneously to measure MBF. The pigs were imaged in list-mode for 11 min starting at the time of injection using a Discovery NM 530c camera (GE Healthcare). Each list file was modified so that 3/4, 1/2, 1/4, 1/8, 1/16, and 1/32 of the original counts were included in the projections. Modified projections were reconstructed with CT-based attenuation correction and an energy window-based scatter correction and analyzed with FlowQuant kinetic modeling software using a 1-compartment model. A modified Renkin-Crone extraction function was used to convert the tracer uptake rate K1 to MBF values. The SPECT results were compared to those from microspheres. Results: Correlation between SPECT and microsphere MBF values for the full injected activity was r ≥ 0.75 for all 3 tracers and did not significantly degrade over all count levels. The mean MBF and MFR and the standard errors in the estimates were not significantly worse than the full-count data at 1/4-counts (Tc99m-tracers) and 1/2-counts (Tl-201). Conclusions: Dynamic SPECT measurement of MBF and MFR in pigs can be performed with 1/4 (Tc99m-tracers) or 1/2 (Tl-201) of the standard injected activity without significantly reducing accuracy and precision.

  12. Lack of acute cardioprotective effect from preischaemic erythropoietin administration in a porcine coronary occlusion model

    DEFF Research Database (Denmark)

    Kristensen, Jens; Mæng, Michael; Rehling, Michael

    2005-01-01

    preconditioning may be involved. Before clinical testing such possible cardioprotective effects needs assessment in an experimental large animal model with closer similarity to human ischaemic pathophysiology. METHODS: A control group and two rhEPO groups were studied. EPO1 pigs were given EPO corresponding...... by myocardial perfusion imaging (MPI) and postmortem by a histochemical procedure (at 150 min of reperfusion). RESULTS: IS/AAR did not differ significantly between control (C), EPO1 and EPO2 groups, neither measured by MPI (mean+/-SD for C: 0.87+/-0.13; EPO1: 0.92+/-0.08; EPO2: 0.87+/-0.11), nor histochemically...... (mean+/-SD for C: 0.64+/-0.20; EPO1: 0.75+/-0.17; EPO2: 0.80+/-0.07). In the EPO2 group mean arterial pulmonary pressure and dP/dtmax were increased compared with control group. CONCLUSION: Despite promising results from studies in rodents, rhEPO did not reduce infarct size measured after 2.5 h...

  13. Characterization of ventricular depolarization and repolarization changes in a porcine model of myocardial infarction.

    Science.gov (United States)

    Romero, Daniel; Ringborn, Michael; Demidova, Marina; Koul, Sasha; Laguna, Pablo; Platonov, Pyotr G; Pueyo, Esther

    2012-12-01

    In this study, several electrocardiogram (ECG)-derived indices corresponding to both ventricular depolarization and repolarization were evaluated during acute myocardial ischemia in an experimental model of myocardial infarction produced by 40 min coronary balloon inflation in 13 pigs. Significant changes were rapidly observed from minute 4 after the start of coronary occlusion, achieving their maximum values between 11 and 22 min for depolarization and between 9 and 12 min for repolarization indices, respectively. Subsequently, these maximum changes started to decrease during the latter part of the occlusion. Depolarization changes associated with the second half of the QRS complex showed a significant but inverse correlation with the myocardium at risk (MaR) estimated by scintigraphic images. The correlation between MaR and changes of the downward slope of the QRS complex, [Formula: see text], evaluated at the two more relevant peaks observed during the occlusion, was r = -0.75, p evolution, respectively. Repolarization changes, analyzed by evaluation of ST segment elevation at the main observed positive peak, also showed negative, however non-significant correlation with MaR: r = -0.34, p = 0.28. Our results suggest that changes evaluated in the latter part of the depolarization, such as those described by [Formula: see text], which are influenced by R-wave amplitude, QRS width and ST level variations simultaneously, correlate better with the amount of ischemia than other indices evaluated in the earlier part of depolarization or during the ST segment.

  14. Dermatopathology effects of simulated solar particle event radiation exposure in the porcine model.

    Science.gov (United States)

    Sanzari, Jenine K; Diffenderfer, Eric S; Hagan, Sarah; Billings, Paul C; Gridley, Daila S; Seykora, John T; Kennedy, Ann R; Cengel, Keith A

    2015-07-01

    The space environment exposes astronauts to risks of acute and chronic exposure to ionizing radiation. Of particular concern is possible exposure to ionizing radiation from a solar particle event (SPE). During an SPE, magnetic disturbances in specific regions of the Sun result in the release of intense bursts of ionizing radiation, primarily consisting of protons that have a highly variable energy spectrum. Thus, SPE events can lead to significant total body radiation exposures to astronauts in space vehicles and especially while performing extravehicular activities. Simulated energy profiles suggest that SPE radiation exposures are likely to be highest in the skin. In the current report, we have used our established miniature pig model system to evaluate the skin toxicity of simulated SPE radiation exposures that closely resemble the energy and fluence profile of the September, 1989 SPE using either conventional radiation (electrons) or proton simulated SPE radiation. Exposure of animals to electron or proton radiation led to dose-dependent increases in epidermal pigmentation, the presence of necrotic keratinocytes at the dermal-epidermal boundary and pigment incontinence, manifested by the presence of melanophages in the derm is upon histological examination. We also observed epidermal hyperplasia and a reduction in vascular density at 30 days following exposure to electron or proton simulated SPE radiation. These results suggest that the doses of electron or proton simulated SPE radiation results in significant skin toxicity that is quantitatively and qualitatively similar. Radiation-induced skin damage is often one of the first clinical signs of both acute and non-acute radiation injury where infection may occur, if not treated. In this report, histopathology analyses of acute radiation-induced skin injury are discussed. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  15. Biomechanical investigation of impact induced rib fractures of a porcine infant surrogate model.

    Science.gov (United States)

    Blackburne, William B; Waddell, J Neil; Swain, Michael V; Alves de Sousa, Ricardo J; Kieser, Jules A

    2016-09-01

    This study investigated the structural, biomechanical and fractographic features of rib fractures in a piglet model, to test the hypothesis that fist impact, apart from thoracic squeezing, may result in lateral costal fractures as observed in abused infants. A mechanical fist with an accelerometer was constructed and fixed to a custom jig. Twenty stillborn piglets in the supine position were impacted on the thoracic cage. The resultant force versus time curves from the accelerometer data showed a number of steps indicative of rib fracture. The correlation between impact force and number of fractures was statistically significant (Pearson׳s r=0.528). Of the fractures visualized, 15 completely pierced the parietal pleura of the thoracic wall, and 5 had butterfly fracture patterning. Scanning electron microscopy showed complete bone fractures, at the zone of impact, were normal to the axis of the ribs. Incomplete vertical fractures, with bifurcation, occurred on the periphery of the contact zone. This work suggests the mechanism of rib failure during a fist impact is typical of the transverse fracture pattern in the anterolateral region associated with cases of non-accidental rib injury. The impact events investigated have a velocity of ~2-3m/s, approximately 2×10(4) times faster than previous quasi-static axial and bending tests. While squeezing the infantile may induce buckle fractures in the anterior as well as posterior region of the highly flexible bones, a fist punch impact event may result in anterolateral transverse fractures. Hence, these findings suggest that the presence of anterolateral rib fractures may result from impact rather than manual compression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Proarrhythmic remodelling of the right ventricle in a porcine model of repaired tetralogy of Fallot

    Science.gov (United States)

    Benoist, David; Dubes, Virginie; Roubertie, François; Gilbert, Stephen H; Charron, Sabine; Constantin, Marion; Elbes, Delphine; Vieillot, Delphine; Quesson, Bruno; Cochet, Hubert; Haïssaguerre, Michel; Rooryck, Caroline; Bordachar, Pierre; Thambo, Jean-Benoit; Bernus, Olivier

    2017-01-01

    Objective The growing adult population with surgically corrected tetralogy of Fallot (TOF) is at risk of arrhythmias and sudden cardiac death. We sought to investigate the contribution of right ventricular (RV) structural and electrophysiological remodelling to arrhythmia generation in a preclinical animal model of repaired TOF (rTOF). Methods and results Pigs mimicking rTOF underwent cardiac MRI functional characterisation and presented with pulmonary regurgitation, RV hypertrophy, dilatation and dysfunction compared with Sham-operated animals (Sham). Optical mapping of rTOF RV-perfused wedges revealed a significant prolongation of RV activation time with slower conduction velocities and regions of conduction slowing well beyond the surgical scar. A reduced protein expression and lateralisation of Connexin-43 were identified in rTOF RVs. A remodelling of extracellular matrix-related gene expression and an increase in collagen content that correlated with prolonged RV activation time were also found in these animals. RV action potential duration (APD) was prolonged in the epicardial anterior region at early and late repolarisation level, thus contributing to a greater APD heterogeneity and to altered transmural and anteroposterior APD gradients in rTOF RVs. APD remodelling involved changes in Kv4.3 and MiRP1 expression. Spontaneous arrhythmias were more frequent in rTOF wedges and more complex in the anterior than in the posterior RV. Conclusion Significant remodelling of RV conduction and repolarisation properties was found in pigs with rTOF. This remodelling generates a proarrhythmic substrate likely to facilitate re-entries and to contribute to sudden cardiac death in patients with rTOF. PMID:28051771

  17. Preclinical Evaluation of Tegaderm™ Supported Nanofibrous Wound Matrix Dressing on Porcine Wound Healing Model.

    Science.gov (United States)

    Ong, Chee Tian; Zhang, Yanzhong; Lim, Raymond; Samsonraj, Rebekah; Masilamani, Jeyakumar; Phan, Tran Hong Ha; Ramakrishna, Seeram; Lim, Ivor; Kee, Irene; Fahamy, Mohammad; Templonuevo, Vilma; Lim, Chwee Teck; Phan, Toan Thang

    2015-02-01

    Objective: Nanofibers for tissue scaffolding and wound dressings hold great potential in realizing enhanced healing of wounds in comparison with conventional counterparts. Previously, we demonstrated good fibroblast adherence and growth on a newly developed scaffold, Tegaderm™-Nanofiber (TG-NF), made from poly ɛ-caprolactone (PCL)/gelatin nanofibers electrospun onto Tegaderm (TG). The purpose of this study is to evaluate the performance and safety of TG-NF dressings in partial-thickness wound in a pig healing model. Approach: To evaluate the rate of reepithelialization, control TG, human dermal fibroblast-seeded TG-NF(+) and -unseeded TG-NF(-) were randomly dressed onto 80 partial-thickness burns created on four female and four male pigs. Wound inspections and dressings were done after burns on day 7, 14, 21, and 28. On day 28, full-thickness biopsies were taken for histopathological evaluation by Masson-Trichrome staining for collagen and hematoxylin-eosin staining for cell counting. Results: No infection and severe inflammation were recorded. Wounds treated with TG-NF(+) reepithelialized significantly faster than TG-NF(-) and control. Wound site inflammatory responses to study groups were similar as total cell counts on granulation tissues show no significant differences. Most of the wounds completely reepithelialized by day 28, except for two wounds in control and TG-NF(-). A higher collagen coverage was also recorded in the granulation tissues treated with TG-NF(+). Innovation and Conclusion: With better reepithelialization achieved by TG-NF(+) and similar rates of wound closure by TG-NF(-) and control, and the absence of elevated inflammatory responses to TG-NF constructs, TG-NF constructs are safe and demonstrated good healing potentials that are comparable to Tegaderm.

  18. Sustained analgesic effect of clonidine co-polymer depot in a porcine incisional pain model.

    Science.gov (United States)

    Wilsey, Jared T; Block, Julie H

    2018-01-01

    Previous research suggests that the α 2 adrenergic agonist clonidine, a centrally acting analgesic and antihypertensive, may also have direct effects on peripheral pain generators. However, aqueous injections are limited by rapid systemic absorption leading to off target effects and a brief analgesic duration of action. The aim of this study was to examine the efficacy of a sustained-release clonidine depot, placed in the wound bed, in a pig incisional pain model. The depot was a 15 mm ×5 mm ×0.3 mm poly(lactide-co-caprolactone) polymer film containing 3% (w/w) clonidine HCl (MDT3). Fifty-two young adult mix Landrace pigs (9-11 kg) were divided into seven groups. All subjects received a 6 cm, full-thickness, linear incision into the left lateral flank. Group 1 served as a Sham control group (Sham, n=8). Group 2 received three placebo strips (PBO, n=8), placed end-to-end in the subcutaneous wound bed before wound closure. Group 3 received one MDT3 and two PBO (n=8), Group 4 received two MDT3 and one PBO (n=8), and Group 5 received three MDT3 (n=8). Positive control groups received peri-incisional injections of bupivacaine solution (Group 6, 30 mg/day bupivacaine, n=8) or clonidine solution (Group 7, 225 µg/day, n=4). The surgical procedure was associated with significant peri-incisional tactile allodynia. There was a dose-dependent effect of MDT3 in partially reversing the peri-incisional tactile allodynia, with maximum pain relief relative to Sham at 72 hours. Daily injections of bupivacaine (30 mg), but not clonidine (up to 225 µg), completely reversed allodynia within 48 hours. There was a statistically significant correlation between the dose of MDT3 and cumulative withdrawal threshold from 4 hours through the conclusion of the study on day 7. These data suggest that a sustained-release clonidine depot may be a viable nonopioid, nonamide anesthetic therapy for the treatment of acute postsurgical nociceptive sensitization.

  19. Large animal evaluation of riboflavin and ultraviolet light-treated whole blood transfusion in a diffuse, nonsurgical bleeding porcine model.

    Science.gov (United States)

    Okoye, Obi T; Reddy, Heather; Wong, Monica D; Doane, Suzann; Resnick, Shelby; Karamanos, Efstathios; Skiada, Dimitra; Goodrich, Raymond; Inaba, Kenji

    2015-03-01

    The Mirasol system has been demonstrated to effectively inactivate white blood cells (WBCs) and reduce pathogens in whole blood in vitro. The purpose of this study was to compare the safety and efficacy of Mirasol-treated fresh whole blood (FWB) to untreated FWB in an in vivo model of surgical bleeding. A total of 18 anesthetized pigs (40 kg) underwent a 35% total blood volume bleed, cooling to 33°C, and a standardized liver injury. Animals were then randomly assigned to resuscitation with either Mirasol-treated or untreated FWB, and intraoperative blood loss was measured. After abdominal closure, the animals were observed for 14 days, after which the animals were euthanized and tissues were obtained for histopathologic examination. Mortality, tissue near-infrared spectroscopy, red blood cell (RBC) variables, platelets (PLTs), WBCs, and coagulation indices were analyzed. Total intraoperative blood loss was similar in test and control arms (8.3 ± 3.2 mL/kg vs. 7.7 ± 3.9 mL/kg, p = 0.720). All animals survived to Day 14. Trended values over time did not show significant differences-tissue oxygenation (p = 0.605), hemoglobin (p = 0.461), PLTs (p = 0.807), WBCs (p = 0.435), prothrombin time (p = 0.655), activated partial thromboplastin time (p = 0.416), thromboelastography (TEG)-reaction time (p = 0.265), or TEG-clot formation time (p = 0.081). Histopathology did not show significant differences between arms. Mirasol-treated FWB did not impact survival, blood loss, tissue oxygen delivery, RBC indices, or coagulation variables in a standardized liver injury model. These data suggest that Mirasol-treated FWB is both safe and efficacious in vivo. © 2015 AABB.

  20. Patterns of glycogen turnover in liver characterized by computer modeling

    International Nuclear Information System (INIS)

    Youn, J.H.; Bergman, R.N.

    1987-01-01

    The authors used a computer model of liver glycogen turnover to reexamine the data of Devos and Hers, who reported the time course of accumulation in and loss from glycogen of label originating in [1- 14 C]galactose injected at different times after the start of refeeding of 40-h fasted mice or rats. In the present study computer representation of individual glycogen molecules was utilized to account for growth and degradation of glycogen according to specific hypothetical patterns. Using this model they could predict the accumulation and localization within glycogen of labeled glucose residues and compare the predictions with the previously published data. They considered three specific hypotheses of glycogen accumulation during refeeding: (1) simultaneous, (2) sequential, and (3) accelerating growth. Hypothetical patterns of glycogen degradation were (1) ordered and (2) random degradation. The pattern of glycogen synthesis consistent with experimental data was a steadily increasing number of growing glycogen molecules, whereas during degradation glycogen molecules are exposed to degrading enzymes randomly, rather than in a specific reverse order of synthesis. These patterns predict the existence of a specific mechanism for the steadily increasing seeding of new glycogen molecules during synthesis

  1. Quantification of Porcine Vocal Fold Geometry.

    Science.gov (United States)

    Stevens, Kimberly A; Thomson, Scott L; Jetté, Marie E; Thibeault, Susan L

    2016-07-01

    The aim of this study was to quantify porcine vocal fold medial surface geometry and three-dimensional geometric distortion induced by freezing the larynx, especially in the region of the vocal folds. The medial surface geometries of five excised porcine larynges were quantified and reported. Five porcine larynges were imaged in a micro-CT scanner, frozen, and rescanned. Segmentations and three-dimensional reconstructions were used to quantify and characterize geometric features. Comparisons were made with geometry data previously obtained using canine and human vocal folds as well as geometries of selected synthetic vocal fold models. Freezing induced an overall expansion of approximately 5% in the transverse plane and comparable levels of nonuniform distortion in sagittal and coronal planes. The medial surface of the porcine vocal folds was found to compare reasonably well with other geometries, although the compared geometries exhibited a notable discrepancy with one set of published human female vocal fold geometry. Porcine vocal folds are qualitatively geometrically similar to data available for canine and human vocal folds, as well as commonly used models. Freezing of tissue in the larynx causes distortion of around 5%. The data can provide direction in estimating uncertainty due to bulk distortion of tissue caused by freezing, as well as quantitative geometric data that can be directly used in developing vocal fold models. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  2. Use of prototype two-channel endoscope with elevator enables larger lift-and-snare endoscopic mucosal resection in a porcine model.

    Science.gov (United States)

    Atkinson, Matthew; Chukwumah, Chike; Marks, Jeffrey; Chak, Amitabh

    2014-02-01

    Flat and depressed lesions are becoming increasingly recognized in the esophagus, stomach, and colon. Various techniques have been described for endoscopic mucosal resection (EMR) of these lesions. To evaluate the efficacy of lift-grasp-cut EMR using a prototype dual-channel forward-viewing endoscope with an instrument elevator in one accessory channel (dual-channel elevator scope) as compared to standard dual-channel endoscopes. EMR was performed using a lift-grasp-cut technique on normal flat rectosigmoid or gastric mucosa in live porcine models after submucosal injection of 4 mL of saline using a dual-channel elevator scope or a standard dual-channel endoscope. With the dual-channel elevator scope, the elevator was used to attain further lifting of the mucosa. The primary endpoint was size of the EMR specimen and the secondary endpoint was number of complications. Twelve experiments were performed (six gastric and six colonic). Mean specimen diameter was 2.27 cm with the dual-channel elevator scope and 1.34 cm with the dual-channel endoscope (P = 0.018). Two colonic perforations occurred with the dual-channel endoscope, vs no complications with the dual-channel elevator scope. The increased lift of the mucosal epithelium, through use of the dual-channel elevator scope, allows for larger EMR when using a lift-grasp-cut technique. Noting the thin nature of the porcine colonic wall, use of the elevator may also make this technique safer.

  3. Model and methods to assess hepatic function from indocyanine green fluorescence dynamical measurements of liver tissue.

    Science.gov (United States)

    Audebert, Chloe; Vignon-Clementel, Irene E

    2018-03-30

    The indocyanine green (ICG) clearance, presented as plasma disappearance rate is, presently, a reliable method to estimate the hepatic "function". However, this technique is not instantaneously available and thus cannot been used intra-operatively (during liver surgery). Near-infrared spectroscopy enables to assess hepatic ICG concentration over time in the liver tissue. This article proposes to extract more information from the liver intensity dynamics by interpreting it through a dedicated pharmacokinetics model. In order to account for the different exchanges between the liver tissues, the proposed model includes three compartments for the liver model (sinusoids, hepatocytes and bile canaliculi). The model output dependency to parameters is studied with sensitivity analysis and solving an inverse problem on synthetic data. The estimation of model parameters is then performed with in-vivo measurements in rabbits (El-Desoky et al. 1999). Parameters for different liver states are estimated, and their link with liver function is investigated. A non-linear (Michaelis-Menten type) excretion rate from the hepatocytes to the bile canaliculi was necessary to reproduce the measurements for different liver conditions. In case of bile duct ligation, the model suggests that this rate is reduced, and that the ICG is stored in the hepatocytes. Moreover, the level of ICG remains high in the blood following the ligation of the bile duct. The percentage of retention of indocyanine green in blood, which is a common test for hepatic function estimation, is also investigated with the model. The impact of bile duct ligation and reduced liver inflow on the percentage of ICG retention in blood is studied. The estimation of the pharmacokinetics model parameters may lead to an evaluation of different liver functions. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Cell sources for in vitro human liver cell culture models

    Science.gov (United States)

    Freyer, Nora; Damm, Georg; Seehofer, Daniel; Knöspel, Fanny

    2016-01-01

    In vitro liver cell culture models are gaining increasing importance in pharmacological and toxicological research. The source of cells used is critical for the relevance and the predictive value of such models. Primary human hepatocytes (PHH) are currently considered to be the gold standard for hepatic in vitro culture models, since they directly reflect the specific metabolism and functionality of the human liver; however, the scarcity and difficult logistics of PHH have driven researchers to explore alternative cell sources, including liver cell lines and pluripotent stem cells. Liver cell lines generated from hepatomas or by genetic manipulation are widely used due to their good availability, but they are generally altered in certain metabolic functions. For the past few years, adult and pluripotent stem cells have been attracting increasing attention, due their ability to proliferate and to differentiate into hepatocyte-like cells in vitro. However, controlling the differentiation of these cells is still a challenge. This review gives an overview of the major human cell sources under investigation for in vitro liver cell culture models, including primary human liver cells, liver cell lines, and stem cells. The promises and challenges of different cell types are discussed with a focus on the complex 2D and 3D culture approaches under investigation for improving liver cell functionality in vitro. Finally, the specific application options of individual cell sources in pharmacological research or disease modeling are described. PMID:27385595

  5. Effect of liver histopathology on islet cell engraftment in the model mimicking autologous islet cell transplantation.

    Science.gov (United States)

    Desai, Chirag S; Khan, Khalid M; Ma, Xiaobo; Li, Henghong; Wang, Juan; Fan, Lijuan; Chen, Guoling; Smith, Jill P; Cui, Wanxing

    2017-11-02

    The inflammatory milieu in the liver as determined by histopathology is different in individual patients undergoing autologous islet cell transplantation. We hypothesized that inflammation related to fatty-liver adversely impacts islet survival. To test this hypothesis, we used a mouse model of fatty-liver to determine the outcome of syngeneic islet transplantation after chemical pancreatectomy. Mice (C57BL/6) were fed a high-fat-diet from 6 weeks of age until attaining a weight of ≥28 grams (6-8 weeks) to produce a fatty liver (histologically > 30% fat);steatosis was confirmed with lipidomic profile of liver tissue. Islets were infused via the intra-portal route in fatty-liver and control mice after streptozotocin induction of diabetes. Outcomes were assessed by the rate of euglycemia, liver histopathology, evaluation of liver inflammation by measuring tissue cytokines IL-1β and TNF-α by RT-PCR and CD31 expression by immunohistochemistry. The difference in the euglycemic fraction between the normal liver group (90%, 9/10) and the fatty-liver group (37.5%, 3/8) was statistically significant at the 18 th day post- transplant and was maintained to the end of the study (day 28) (p = 0.019, X 2 = 5.51). Levels of TNF-α and IL-1β were elevated in fatty-liver mice (p = 0.042, p = 0.037). Compared to controls cytokine levels were elevated after islet cell transplantation and in transplanted fatty-liver mice as compared to either fatty- or islet transplant group alone (p = NS). A difference in the histochemical pattern of CD31 could not be determined. Fatty-liver creates an inflammatory state which adversely affects the outcome of autologous islet cell transplantation.

  6. A composite computational model of liver glucose homeostasis. I. Building the composite model.

    Science.gov (United States)

    Hetherington, J; Sumner, T; Seymour, R M; Li, L; Rey, M Varela; Yamaji, S; Saffrey, P; Margoninski, O; Bogle, I D L; Finkelstein, A; Warner, A

    2012-04-07

    A computational model of the glucagon/insulin-driven liver glucohomeostasis function, focusing on the buffering of glucose into glycogen, has been developed. The model exemplifies an 'engineering' approach to modelling in systems biology, and was produced by linking together seven component models of separate aspects of the physiology. The component models use a variety of modelling paradigms and degrees of simplification. Model parameters were determined by an iterative hybrid of fitting to high-scale physiological data, and determination from small-scale in vitro experiments or molecular biological techniques. The component models were not originally designed for inclusion within such a composite model, but were integrated, with modification, using our published modelling software and computational frameworks. This approach facilitates the development of large and complex composite models, although, inevitably, some compromises must be made when composing the individual models. Composite models of this form have not previously been demonstrated.

  7. Short communication Identification of gene variation within porcine ...

    African Journals Online (AJOL)

    user

    characteristics and possible biological function of porcine PRDM16 gene have been less reported. ... included the heart, liver, spleen, lung, kidney, brain, longissimus dorsi muscle, interior fat, stomach, small ... al., 2008), and the copy number of PRDM16 molecules of patients with osteosarcoma was .... BMC Cancer 4, 45.

  8. Computer-based decision making in medicine : A model for surgery of colorectal liver metastases

    NARCIS (Netherlands)

    Langenhoff, B S; Krabbe, P F M; Ruers, T J M

    2007-01-01

    AIMS: Seeking the best available treatment for patients with colorectal liver metastases may be complex due to the interpretation of many variables. In this study conjoint analysis is used to develop a decision model to help clinicians selecting patients eligible for surgery of liver metastases.

  9. Long-Term Adult Feline Liver Organoid Cultures for Disease Modeling of Hepatic Steatosis.

    Science.gov (United States)

    Kruitwagen, Hedwig S; Oosterhoff, Loes A; Vernooij, Ingrid G W H; Schrall, Ingrid M; van Wolferen, Monique E; Bannink, Farah; Roesch, Camille; van Uden, Lisa; Molenaar, Martijn R; Helms, J Bernd; Grinwis, Guy C M; Verstegen, Monique M A; van der Laan, Luc J W; Huch, Meritxell; Geijsen, Niels; Vries, Robert G; Clevers, Hans; Rothuizen, Jan; Schotanus, Baukje A; Penning, Louis C; Spee, Bart

    2017-04-11

    Hepatic steatosis is a highly prevalent liver disease, yet research is hampered by the lack of tractable cellular and animal models. Steatosis also occurs in cats, where it can cause severe hepatic failure. Previous studies demonstrate the potential of liver organoids for modeling genetic diseases. To examine the possibility of using organoids to model steatosis, we established a long-term feline liver organoid culture with adult liver stem cell characteristics and differentiation potential toward hepatocyte-like cells. Next, organoids from mouse, human, dog, and cat liver were provided with fatty acids. Lipid accumulation was observed in all organoids and interestingly, feline liver organoids accumulated more lipid droplets than human organoids. Finally, we demonstrate effects of interference with β-oxidation on lipid accumulation in feline liver organoids. In conclusion, feline liver organoids can be successfully cultured and display a predisposition for lipid accumulation, making them an interesting model in hepatic steatosis research. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. Modeled Perfluorooctanoic Acid (PFOA) Exposure and Liver Function in a Mid-Ohio Valley Community.

    Science.gov (United States)

    Darrow, Lyndsey A; Groth, Alyx C; Winquist, Andrea; Shin, Hyeong-Moo; Bartell, Scott M; Steenland, Kyle

    2016-08-01

    Perfluorooctanoic acid (PFOA or C8) has hepatotoxic effects in animals. Cross-sectional epidemiologic studies suggest PFOA is associated with liver injury biomarkers. We estimated associations between modeled historical PFOA exposures and liver injury biomarkers and medically validated liver disease. Participants completed surveys during 2008-2011 reporting demographic, medical, and residential history information. Self-reported liver disease, including hepatitis, fatty liver, enlarged liver and cirrhosis, was validated with healthcare providers. Alanine aminotransferase (ALT), γ-glutamyltransferase (GGT) and direct bilirubin, markers of liver toxicity, were obtained from blood samples collected in the C8 Health Project (2005-2006). Historically modeled PFOA exposure, estimated using environmental fate and transport models and participant residential histories, was analyzed in relation to liver biomarkers (n = 30,723, including 1,892 workers) and liver disease (n = 32,254, including 3,713 workers). Modeled cumulative serum PFOA was positively associated with ALT levels (p for trend indicating possible liver toxicity. An increase from the first to the fifth quintile of cumulative PFOA exposure was associated with a 6% increase in ALT levels (95% CI: 4, 8%) and a 16% increased odds of having above-normal ALT (95% CI: odds ratio: 1.02, 1.33%). There was no indication of association with either elevated direct bilirubin or GGT; however, PFOA was associated with decreased direct bilirubin. We observed no evidence of an effect of cumulative exposure (with or without a 10-year lag) on all liver disease (n = 647 cases), nor on enlarged liver, fatty liver, and cirrhosis only (n = 427 cases). Results are consistent with previous cross-sectional studies showing association between PFOA and ALT, a marker of hepatocellular damage. We did not observe evidence that PFOA increases the risk of clinically diagnosed liver disease. Darrow LA, Groth AC, Winquist A, Shin HM, Bartell SM

  11. Human Umbilical Cord-Derived Mesenchymal Stromal Cells Improve Left Ventricular Function, Perfusion, and Remodeling in a Porcine Model of Chronic Myocardial Ischemia

    Science.gov (United States)

    Liu, Chuan-Bin; Huang, He; Sun, Ping; Ma, Shi-Ze; Liu, An-Heng; Xue, Jian; Fu, Jin-Hui; Liang, Yu-Qian; Liu, Bing; Wu, Dong-Ying

    2016-01-01

    Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton’s jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia. Significance Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called “no-option” patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation. PMID

  12. Robotic kidney autotransplantation in a porcine model: a procedure-specific training platform for the simulation of robotic intracorporeal vascular anastomosis.

    Science.gov (United States)

    Tiong, Ho Yee; Goh, Benjamin Yen Seow; Chiong, Edmund; Tan, Lincoln Guan Lim; Vathsala, Anatharaman

    2018-03-31

    Robotic-assisted kidney transplantation (RKT) with the Da Vinci (Intuitive, USA) platform has been recently developed to improve outcomes by decreasing surgical site complications and morbidity, especially in obese patients. This potential paradigm shift in the surgical technique of kidney transplantation is performed in only a few centers. For wider adoption of this high stake complex operation, we aimed to develop a procedure-specific simulation platform in a porcine model for the training of robotic intracorporeal vascular anastomosis and evaluating vascular anastomoses patency. This paper describes the requirements and steps developed for the above training purpose. Over a series of four animal ethics' approved experiments, the technique of robotic-assisted laparoscopic autotransplantation of the kidney was developed in Amsterdam live pigs (60-70 kg). The surgery was based around the vascular anastomosis technique described by Menon et al. This non-survival porcine training model is targeted at transplant surgeons with robotic surgery experience. Under general anesthesia, each pig was placed in lateral decubitus position with the placement of one robotic camera port, two robotic 8 mm ports and one assistant port. Robotic docking over the pig posteriorly was performed. The training platform involved the following procedural steps. First, ipsilateral iliac vessel dissection was performed. Second, robotic-assisted laparoscopic donor nephrectomy was performed with in situ perfusion of the kidney with cold Hartmann's solution prior to complete division of the hilar vessels, ureter and kidney mobilization. Thirdly, the kidney was either kept in situ for orthotopic autotransplantation or mobilized to the pelvis and orientated for the vascular anastomosis, which was performed end to end or end to side after vessel loop clamping of the iliac vessels, respectively, using 6/0 Gore-Tex sutures. Following autotransplantation and release of vessel loops, perfusion of the

  13. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

    International Nuclear Information System (INIS)

    Davis, Catherine C.; Baccam, Mekhine; Mantz, Mary J.; Osborn, Thomas W.; Hill, Donna R.; Squier, Christopher A.

    2014-01-01

    Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen—TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ( 3 H 2 O) through porcine vaginal mucosa was determined at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52 °C) did not significantly increase flux of 3 H 2 O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of 3 H 2 O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. - Highlights: • Model assessed local effects of tampon use on vaginal mucosa. • Risks were evaluated using two tracers to assess permeability in an ex vivo model. • Mechanical damage to the epithelial surface increased tracer penetration. • Surfactants increased

  14. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Catherine C.; Baccam, Mekhine [Feminine Care Global Product Stewardship, 6110 Center Hill Road, The Procter and Gamble Company, Cincinnati, OH 45224 (United States); Mantz, Mary J. [Dows Institute for Dental Research, The University of Iowa, Iowa City, IA 52242 (United States); Osborn, Thomas W.; Hill, Donna R. [Feminine Care Product Development, 6110 Center Hill Road, The Procter and Gamble Company, Cincinnati, OH 45224 (United States); Squier, Christopher A. [Dows Institute for Dental Research, The University of Iowa, Iowa City, IA 52242 (United States)

    2014-01-15

    Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen—TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ({sup 3}H{sub 2}O) through porcine vaginal mucosa was determined at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52 °C) did not significantly increase flux of {sup 3}H{sub 2}O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of {sup 3}H{sub 2}O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. - Highlights: • Model assessed local effects of tampon use on vaginal mucosa. • Risks were evaluated using two tracers to assess permeability in an ex vivo model. • Mechanical damage to the epithelial surface increased tracer penetration.

  15. Statistical Fractal Models Based on GND-PCA and Its Application on Classification of Liver Diseases

    Directory of Open Access Journals (Sweden)

    Huiyan Jiang

    2013-01-01

    Full Text Available A new method is proposed to establish the statistical fractal model for liver diseases classification. Firstly, the fractal theory is used to construct the high-order tensor, and then Generalized -dimensional Principal Component Analysis (GND-PCA is used to establish the statistical fractal model and select the feature from the region of liver; at the same time different features have different weights, and finally, Support Vector Machine Optimized Ant Colony (ACO-SVM algorithm is used to establish the classifier for the recognition of liver disease. In order to verify the effectiveness of the proposed method, PCA eigenface method and normal SVM method are chosen as the contrast methods. The experimental results show that the proposed method can reconstruct liver volume better and improve the classification accuracy of liver diseases.

  16. Lentiviral Vector Gene Transfer to Porcine Airways

    Directory of Open Access Journals (Sweden)

    Patrick L Sinn

    2012-01-01

    Full Text Available In this study, we investigated lentiviral vector development and transduction efficiencies in well-differentiated primary cultures of pig airway epithelia (PAE and wild-type pigs in vivo. We noted gene transfer efficiencies similar to that observed for human airway epithelia (HAE. Interestingly, feline immunodeficiency virus (FIV-based vectors transduced immortalized pig cells as well as pig primary cells more efficiently than HIV-1–based vectors. PAE express TRIM5α, a well-characterized species-specific lentiviral restriction factor. We contrasted the restrictive properties of porcine TRIM5α against FIV- and HIV-based vectors using gain and loss of function approaches. We observed no effect on HIV-1 or FIV conferred transgene expression in response to porcine TRIM5α overexpression or knockdown. To evaluate the ability of GP64-FIV to transduce porcine airways in vivo, we delivered vector expressing mCherry to the tracheal lobe of the lung and the ethmoid sinus of 4-week-old pigs. One week later, epithelial cells expressing mCherry were readily detected. Our findings indicate that pseudotyped FIV vectors confer similar tropisms in porcine epithelia as observed in human HAE and provide further support for the selection of GP64 as an appropriate envelope pseudotype for future preclinical gene therapy studies in the porcine model of cystic fibrosis (CF.

  17. A prediction model for the grade of liver fibrosis using magnetic resonance elastography.

    Science.gov (United States)

    Mitsuka, Yusuke; Midorikawa, Yutaka; Abe, Hayato; Matsumoto, Naoki; Moriyama, Mitsuhiko; Haradome, Hiroki; Sugitani, Masahiko; Tsuji, Shingo; Takayama, Tadatoshi

    2017-11-28

    Liver stiffness measurement (LSM) has recently become available for assessment of liver fibrosis. We aimed to develop a prediction model for liver fibrosis using clinical variables, including LSM. We performed a prospective study to compare liver fibrosis grade with fibrosis score. LSM was measured using magnetic resonance elastography in 184 patients that underwent liver resection, and liver fibrosis grade was diagnosed histologically after surgery. Using the prediction model established in the training group, we validated the classification accuracy in the independent test group. First, we determined a cut-off value for stratifying fibrosis grade using LSM in 122 patients in the training group, and correctly diagnosed fibrosis grades of 62 patients in the test group with a total accuracy of 69.3%. Next, on least absolute shrinkage and selection operator analysis in the training group, LSM (r = 0.687, P prediction model. This prediction model applied to the test group correctly diagnosed 32 of 36 (88.8%) Grade I (F0 and F1) patients, 13 of 18 (72.2%) Grade II (F2 and F3) patients, and 7 of 8 (87.5%) Grade III (F4) patients in the test group, with a total accuracy of 83.8%. The prediction model based on LSM, ICGR15, and platelet count can accurately and reproducibly predict liver fibrosis grade.

  18. Progress, problems and prospects of porcine pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Hanning WANG,Yangli PEI,Ning LI,Jianyong HAN

    2014-02-01

    Full Text Available Pluripotent stem cells (PSCs, including embryonic stem cells (ESCs and induced PSCs (iPSCs, can differentiate into cells of the three germ layers, suggesting that PSCs have great potential for basic developmental biology research and wide applications for clinical medicine. Genuine ESCs and iPSCs have been derived from mice and rats, but not from livestock such as the pig─an ideal animal model for studying human disease and regenerative medicine due to similarities with human physiologic processes. Efforts to derive porcine ESCs and iPSCs have not yielded high-quality PSCs that can produce chimeras with germline transmission. Thus, exploration of the unique porcine gene regulation network of preimplantation embryonic development may permit optimization of in vitro culture systems for raising porcine PSCs. Here we summarize the recent progress in porcine PSC generation as well as the problems encountered during this progress and we depict prospects for generating porcine naive PSCs.

  19. Elicitation of strong immune responses by a DNA vaccine expressing a secreted form of hepatitis C virus envelope protein E2 in murine and porcine animal models

    DEFF Research Database (Denmark)

    Li, Yiping; Kang, H.N.; Babiuk, L.A.

    2006-01-01

    boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-gamma secreting cells, and cytotoxic T lymphocyte assays...... and shifted the immune response towards Th2-like ones in piglets. CONCLUSION: A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response......AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without...

  20. Plaque Burden Influences Accurate Classification of Fibrous Cap Atheroma by In-Vivo Optical Coherence Tomography in a Porcine Model of Advanced Coronary Atherosclerosis

    DEFF Research Database (Denmark)

    Poulsen, Christian B; Pedrigi, Ryan M; Pareek, Nilesh

    2018-01-01

    AIMS: In-vivo validation of coronary optical coherence tomography (OCT) against histology and the effects of plaque burden (PB) on plaque classification remain unreported. We investigated this in a porcine model with human-like coronary atherosclerosis. METHODS AND RESULTS: Five female Yucatan D374...... a validated algorithm. Lesions were adjudicated using the Virmani classification and PB assessed from histology. OCT had a high sensitivity, but modest specificity (92.9% and 74.6%), for identifying fibrous cap atheroma (FCA). The reduced specificity for OCT was due to misclassification of plaques...... with histologically defined pathological intimal thickening (PIT) as FCA (46.1% of the frames with histological PIT were misclassified). PIT lesions misclassified as FCA by OCT had a statistically higher PB than in other OCT frames (median 32.0% versus 13.4%; p

  1. The unsuitability of implantable Doppler probes for the early detection of renal vascular complications - a porcine model for prevention of renal transplant loss

    DEFF Research Database (Denmark)

    Amdisen, Chris; Jespersen, Bente; Møldrup, Ulla

    2017-01-01

    Abstract Background: Vascular occlusion is a rare, but serious complication after kidney transplantation often resulting in graft loss. We therefore aimed to develop an experimental porcine model for stepwise reduction of the renal venous blood flow and to compare an implantable Doppler probe...... and microdialysis for fast detection of vascular occlusion. Methods: In 20 pigs, implantable Doppler probes were placed on the renal artery and vein and a microdialysis catheter was placed in the renal cortex. An arterial flowprobe served as gold standard. Following two-hour baseline measurements, the pigs were....../3 (66%) reduction in renal blood flow. The implantable Doppler probe was not able to detect flow changes until there was total venous occlusion. Microdialysis detected changes in local metabolism after both arterial and venous occlusion; the implantable Doppler probe could only detect vascular...

  2. Inactivated Orf virus (Parapoxvirus ovis) elicits antifibrotic activity in models of liver fibrosis.

    Science.gov (United States)

    Nowatzky, Janina; Knorr, Andreas; Hirth-Dietrich, Claudia; Siegling, Angela; Volk, Hans-Dieter; Limmer, Andreas; Knolle, Percy; Weber, Olaf

    2013-05-01

    Inactivated Orf virus (ORFV, Parapoxvirus ovis) demonstrates strong antiviral activity in animal models including a human hepatitis B virus (HBV)-transgenic mouse. In addition, expression of interferon (IFN)-γ and interleukin-10 (IL-10) was induced after administration of inactivated ORFV in these mice. IFN-γ and IL-10 are known to elicit antifibrotic activity. We therefore aimed to study antifibrotic activity of inactivated ORFV in models of liver fibrosis. We characterized ORFV-induced hepatic cytokine expression in rats. We then studied ORFV in two models of liver fibrosis in rats, pig serum-induced liver fibrosis and carbon tetrachloride (CCL4 )-induced liver fibrosis. ORFV induced hepatic expression of IFN-γ and IL-10 in rats. ORFV mediated antifibrotic activity when administrated concomitantly with the fibrosis-inducing agents in both models of liver fibrosis. Importantly, when CCL4 -induced liver fibrosis was already established, ORFV application still showed significant antifibrotic activity. In addition, we were able to demonstrate a direct antifibrotic effect of ORFV on stellate cells. These results establish a potential novel antifibrotic therapeutic approach that not only prevents but also resolves established liver fibrosis. Further studies are required to unravel the details of the mechanisms involved. © 2012 The Japan Society of Hepatology.

  3. Establishment of a rat model of early-stage liver failure and Th17/Treg imbalance

    OpenAIRE

    LI Dong; LU Zhonghua; GAN Jianhe

    2016-01-01

    ObjectiveTo investigate the methods for establishing a rat model of early-stage liver failure and the changes in Th17, Treg, and Th17/Treg after dexamethasone and thymosin interventions. MethodsA total of 64 rats were randomly divided into carbon tetrachloride (CCl4) group and endotoxin [lipopolysaccharide (LPS)]/D-galactosamine (D-GalN) combination group to establish the rat model of early-stage liver failure. The activities of the rats and changes in liver function and whole blood Th17 and ...

  4. Opening the Blood-Brain Barrier with MR Imaging-guided Focused Ultrasound: Preclinical Testing on a Trans-Human Skull Porcine Model.

    Science.gov (United States)

    Huang, Yuexi; Alkins, Ryan; Schwartz, Michael L; Hynynen, Kullervo

    2017-01-01

    Purpose To develop and test a protocol in preparation for a clinical trial on opening the blood-brain barrier (BBB) with magnetic resonance (MR) imaging-guided focused ultrasound for the delivery of chemotherapy drugs to brain tumors. Materials and Methods The procedures were approved by the institutional animal care committee. A trans-human skull porcine model was designed for the preclinical testing. Wide craniotomies were applied in 11 pigs (weight, approximately 15 kg). A partial human skull was positioned over the animal's brain. A modified clinical MR imaging-guided focused ultrasound brain system was used with a 3.0-T MR unit. The ultrasound beam was steered during sonications over a 3 × 3 grid at 3-mm spacing. Acoustic power levels of 3-20 W were tested. Bolus injections of microbubbles at 4 μL/kg were tested for each sonication. Levels of BBB opening, hemorrhage, and cavitation signal were measured with MR imaging, histologic examination, and cavitation receivers, respectively. A cavitation safety algorithm was developed on the basis of logistic regression of the measurements and tested to minimize the risk of hemorrhage. Results BBB openings of approximately 1 cm 3 in volume were visualized with gadolinium-enhanced MR imaging after sonication at an acoustic power of approximately 5 W. Gross examination of histologic specimens helped confirm Evans blue (bound to macromolecule albumin) extravasation, and hematoxylin-eosin staining helped detect only scattered extravasation of red blood cells. In cases where cavitation signals were higher than thresholds, sonications were terminated immediately without causing hemorrhage. Conclusion With a trans-human skull porcine model, this study demonstrated BBB opening with a 230-kHz system in preparation for a clinical trial. © RSNA, 2016 Online supplemental material is available for this article.

  5. Combined administration of mesenchymal stem cells overexpressing IGF-1 and HGF enhances neovascularization but moderately improves cardiac regeneration in a porcine model.

    Science.gov (United States)

    Gómez-Mauricio, Guadalupe; Moscoso, Isabel; Martín-Cancho, María-Fernanda; Crisóstomo, Verónica; Prat-Vidal, Cristina; Báez-Díaz, Claudia; Sánchez-Margallo, Francisco M; Bernad, Antonio

    2016-07-16

    Insulin-like growth factor 1 (IGF-1) and hepatocyte growth factor (HGF) are among the most promising growth factors for promoting cardiorepair. Here, we evaluated the combination of cell- and gene-based therapy using mesenchymal stem cells (MSC) genetically modified to overexpress IGF-1 or HGF to treat acute myocardial infarction (AMI) in a porcine model. Pig MSC from adipose tissue (paMSC) were genetically modified for evaluation of different therapeutic strategies to improve AMI treatment. Three groups of infarcted Large White pigs were compared (I, control, non-transplanted; II, transplanted with paMSC-GFP (green fluorescent protein); III, transplanted with paMSC-IGF-1/HGF). Cardiac function was evaluated non-invasively using magnetic resonance imaging (MRI) for 1 month. After euthanasia and sampling of the animal, infarcted areas were studied by histology and immunohistochemistry. Intramyocardial transplant in a porcine infarct model demonstrated the safety of paMSC in short-term treatments. Treatment with paMSC-IGF-1/HGF (1:1) compared with the other groups showed a clear reduction in inflammation in some sections analyzed and promoted angiogenic processes in ischemic tissue. Although cardiac function parameters were not significantly improved, cell retention and IGF-1 overexpression was confirmed within the myocardium. The simultaneous administration of IGF-1- and HGF-overexpressing paMSC appears not to promote a synergistic effect or effective repair. The combined enhancement of neovascularization and fibrosis in paMSC-IGF-1/HGF-treated animals nonetheless suggests that sustained exposure to high IGF-1 + HGF levels promotes beneficial as well as deleterious effects that do not improve overall cardiac regeneration.

  6. A comparative study of precision cut liver slices, hepatocytes, and liver microsomes from the Wistar rat using metronidazole as a model substance

    DEFF Research Database (Denmark)

    Sidelmann, U. G.; Cornett, Claus; Tjornelund, J.

    1996-01-01

    1. Metronidazole is metabolized by rat liver in vitro models to form a hydroxy metabolite, an acetic acid metabolite, a glucuronic acid conjugate, and a sulphate conjugate. 2. Four different in vitro systems for investigation of drug metabolism based on liver preparations from the male Wistar rat...

  7. Development and validation of a dynamic outcome prediction model for paracetamol-induced acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Wang, Yanzhong; Maggs, James

    2016-01-01

    : The models developed here show very good discrimination and calibration, confirmed in independent datasets, and suggest that many patients undergoing transplantation based on existing criteria might have survived with medical management alone. The role and indications for emergency liver transplantation......BACKGROUND: Early, accurate prediction of survival is central to management of patients with paracetamol-induced acute liver failure to identify those needing emergency liver transplantation. Current prognostic tools are confounded by recent improvements in outcome independent of emergency liver...... transplantation, and constrained by static binary outcome prediction. We aimed to develop a simple prognostic tool to reflect current outcomes and generate a dynamic updated estimation of risk of death. METHODS: Patients with paracetamol-induced acute liver failure managed at intensive care units in the UK...

  8. The Role of Interface on the Impact Characteristics and Cranial Fracture Patterns Using the Immature Porcine Head Model.

    Science.gov (United States)

    Deland, Trevor S; Niespodziewanski, Emily; Fenton, Todd W; Haut, Roger C

    2016-01-01

    The role of impact interface characteristics on the biomechanics and patterns of cranial fracture has not been investigated in detail, and especially for the pediatric head. In this study, infant porcine skulls aged 2-19 days were dropped with an energy to cause fracturing onto four surfaces varying in stiffness from a rigid plate to one covered with plush carpeting. Results showed that heads dropped onto the rigid surface produced more extensive cranial fracturing than onto carpeted surfaces. Contact forces generated at fracture initiation and the overall maximum contact forces were generally lower for the rigid than carpeted impacts. While the degree of cranial fracturing from impacts onto the heavy carpeted surface was comparable to that of lower-energy rigid surface impacts, there were fewer diastatic fractures. This suggests that characteristics of the cranial fracture patterns may be used to differentiate energy level from impact interface in pediatric forensic cases. © 2015 American Academy of Forensic Sciences.

  9. Towards Additive Manufacture of Functional, Spline-Based Morphometric Models of Healthy and Diseased Coronary Arteries: In Vitro Proof-of-Concept Using a Porcine Template

    Directory of Open Access Journals (Sweden)

    Rachel Jewkes

    2018-02-01

    Full Text Available The aim of this study is to assess the additive manufacture of morphometric models of healthy and diseased coronary arteries. Using a dissected porcine coronary artery, a model was developed with the use of computer aided engineering, with splines used to design arteries in health and disease. The model was altered to demonstrate four cases of stenosis displaying varying severity, based on published morphometric data available. Both an Objet Eden 250 printer and a Solidscape 3Z Pro printer were used in this analysis. A wax printed model was set into a flexible thermoplastic and was valuable for experimental testing with helical flow patterns observed in healthy models, dominating the distal LAD (left anterior descending and left circumflex arteries. Recirculation zones were detected in all models, but were visibly larger in the stenosed cases. Resin models provide useful analytical tools for understanding the spatial relationships of blood vessels, and could be applied to preoperative planning techniques, but were not suitable for physical testing. In conclusion, it is feasible to develop blood vessel models enabling experimental work; further, through additive manufacture of bio-compatible materials, there is the possibility of manufacturing customized replacement arteries.

  10. Towards Additive Manufacture of Functional, Spline-Based Morphometric Models of Healthy and Diseased Coronary Arteries: In Vitro Proof-of-Concept Using a Porcine Template.

    Science.gov (United States)

    Jewkes, Rachel; Burton, Hanna E; Espino, Daniel M

    2018-02-02

    The aim of this study is to assess the additive manufacture of morphometric models of healthy and diseased coronary arteries. Using a dissected porcine coronary artery, a model was developed with the use of computer aided engineering, with splines used to design arteries in health and disease. The model was altered to demonstrate four cases of stenosis displaying varying severity, based on published morphometric data available. Both an Objet Eden 250 printer and a Solidscape 3Z Pro printer were used in this analysis. A wax printed model was set into a flexible thermoplastic and was valuable for experimental testing with helical flow patterns observed in healthy models, dominating the distal LAD (left anterior descending) and left circumflex arteries. Recirculation zones were detected in all models, but were visibly larger in the stenosed cases. Resin models provide useful analytical tools for understanding the spatial relationships of blood vessels, and could be applied to preoperative planning techniques, but were not suitable for physical testing. In conclusion, it is feasible to develop blood vessel models enabling experimental work; further, through additive manufacture of bio-compatible materials, there is the possibility of manufacturing customized replacement arteries.

  11. A Model for Micro-Dosimetry in Virtual Liver Tissues

    Science.gov (United States)

    Motivation: Humans are potentially exposed to over 6,000 environmental chemicals. The liver is the primary organ for metabolism and often the first site of chemical-induced toxicity in animal testing, but it remains difficult to translate these outcomes to humans. To address thi...

  12. A Multiscale Agent-Based in silico Model of Liver Fibrosis Progression

    Energy Technology Data Exchange (ETDEWEB)

    Dutta-Moscato, Joyeeta [Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA (United States); Department of Surgery, University of Pittsburgh, Pittsburgh, PA (United States); Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Solovyev, Alexey [Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Department of Mathematics, University of Pittsburgh, Pittsburgh, PA (United States); Mi, Qi [Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA (United States); Nishikawa, Taichiro [McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Department of Surgery, Children’s Hospital of Pittsburgh, Pittsburgh, PA (United States); Soto-Gutierrez, Alejandro [McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Department of Pathology, University of Pittsburgh, Pittsburgh, PA (United States); Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA (United States); Fox, Ira J. [McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Department of Surgery, Children’s Hospital of Pittsburgh, Pittsburgh, PA (United States); Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA (United States); Vodovotz, Yoram, E-mail: vodovotzy@upmc.edu [Department of Surgery, University of Pittsburgh, Pittsburgh, PA (United States); Center for Inflammation and Regenerative Modeling, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA (United States)

    2014-05-30

    Chronic hepatic inflammation involves a complex interplay of inflammatory and mechanical influences, ultimately manifesting in a characteristic histopathology of liver fibrosis. We created an agent-based model (ABM) of liver tissue in order to computationally examine the consequence of liver inflammation. Our liver fibrosis ABM (LFABM) is comprised of literature-derived rules describing molecular and histopathological aspects of inflammation and fibrosis in a section of chemically injured liver. Hepatocytes are modeled as agents within hexagonal lobules. Injury triggers an inflammatory reaction, which leads to activation of local Kupffer cells and recruitment of monocytes from circulation. Portal fibroblasts and hepatic stellate cells are activated locally by the products of inflammation. The various agents in the simulation are regulated by above-threshold concentrations of pro- and anti-inflammatory cytokines and damage-associated molecular pattern molecules. The simulation progresses from chronic inflammation to collagen deposition, exhibiting periportal fibrosis followed by bridging fibrosis, and culminating in disruption of the regular lobular structure. The ABM exhibited key histopathological features observed in liver sections from rats treated with carbon tetrachloride (CCl{sub 4}). An in silico “tension test” for the hepatic lobules predicted an overall increase in tissue stiffness, in line with clinical elastography literature and published studies in CCl{sub 4}-treated rats. Therapy simulations suggested differential anti-fibrotic effects of neutralizing tumor necrosis factor alpha vs. enhancing M2 Kupffer cells. We conclude that a computational model of liver inflammation on a structural skeleton of physical forces can recapitulate key histopathological and macroscopic properties of CCl{sub 4}-injured liver. This multiscale approach linking molecular and chemomechanical stimuli enables a model that could be used to gain translationally relevant

  13. A Multiscale Agent-Based in silico Model of Liver Fibrosis Progression

    International Nuclear Information System (INIS)

    Dutta-Moscato, Joyeeta; Solovyev, Alexey; Mi, Qi; Nishikawa, Taichiro; Soto-Gutierrez, Alejandro; Fox, Ira J.; Vodovotz, Yoram

    2014-01-01

    Chronic hepatic inflammation involves a complex interplay of inflammatory and mechanical influences, ultimately manifesting in a characteristic histopathology of liver fibrosis. We created an agent-based model (ABM) of liver tissue in order to computationally examine the consequence of liver inflammation. Our liver fibrosis ABM (LFABM) is comprised of literature-derived rules describing molecular and histopathological aspects of inflammation and fibrosis in a section of chemically injured liver. Hepatocytes are modeled as agents within hexagonal lobules. Injury triggers an inflammatory reaction, which leads to activation of local Kupffer cells and recruitment of monocytes from circulation. Portal fibroblasts and hepatic stellate cells are activated locally by the products of inflammation. The various agents in the simulation are regulated by above-threshold concentrations of pro- and anti-inflammatory cytokines and damage-associated molecular pattern molecules. The simulation progresses from chronic inflammation to collagen deposition, exhibiting periportal fibrosis followed by bridging fibrosis, and culminating in disruption of the regular lobular structure. The ABM exhibited key histopathological features observed in liver sections from rats treated with carbon tetrachloride (CCl 4 ). An in silico “tension test” for the hepatic lobules predicted an overall increase in tissue stiffness, in line with clinical elastography literature and published studies in CCl 4 -treated rats. Therapy simulations suggested differential anti-fibrotic effects of neutralizing tumor necrosis factor alpha vs. enhancing M2 Kupffer cells. We conclude that a computational model of liver inflammation on a structural skeleton of physical forces can recapitulate key histopathological and macroscopic properties of CCl 4 -injured liver. This multiscale approach linking molecular and chemomechanical stimuli enables a model that could be used to gain translationally relevant insights into

  14. How predictive quantitative modelling of tissue organisation can inform liver disease pathogenesis.

    Science.gov (United States)

    Drasdo, Dirk; Hoehme, Stefan; Hengstler, Jan G

    2014-10-01

    From the more than 100 liver diseases described, many of those with high incidence rates manifest themselves by histopathological changes, such as hepatitis, alcoholic liver disease, fatty liver disease, fibrosis, and, in its later stages, cirrhosis, hepatocellular carcinoma, primary biliary cirrhosis and other disorders. Studies of disease pathogeneses are largely based on integrating -omics data pooled from cells at different locations with spatial information from stained liver structures in animal models. Even though this has led to significant insights, the complexity of interactions as well as the involvement of processes at many different time and length scales constrains the possibility to condense disease processes in illustrations, schemes and tables. The combination of modern imaging modalities with image processing and analysis, and mathematical models opens up a promising new approach towards a quantitative understanding of pathologies and of disease processes. This strategy is discussed for two examples, ammonia metabolism after drug-induced acute liver damage, and the recovery of liver mass as well as architecture during the subsequent regeneration process. This interdisciplinary approach permits integration of biological mechanisms and models of processes contributing to disease progression at various scales into mathematical models. These can be used to perform in silico simulations to promote unravelling the relation between architecture and function as below illustrated for liver regeneration, and bridging from the in vitro situation and animal models to humans. In the near future novel mechanisms will usually not be directly elucidated by modelling. However, models will falsify hypotheses and guide towards the most informative experimental design. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  15. Therapeutic effect of angiogenesis inhibitor combined with radiotherapy on liver metastasis model of colon cancer

    International Nuclear Information System (INIS)

    Jin Liugen; Zhou Shifu

    2005-01-01

    Objective: To observe the therapeutic effect of angiogenesis inhibitor combined with radiotherapy on liver metastasis model of colon cancer. Methods: Nude mice liver metastasis model of colon cancer was established with human colon cancer cells line (LS174T) inoculated into mice' spleen and followed by splenectomy. Angiogenesis inhibitor 2-ME and radiotherapy were administered after-wads. The growth inhibition effect on metastases and neovessel was examined. Results: The incidences of liver metastasis were 100% in this intrasplenic injection model. The mean weight and microvessel density 4 weeks after inoculation were 53.6 ± 4.7 mg, 8.4 ± 1.7 in treatment group as compared to 173.9 ± 11.6 mg, 41.2 ± 6.3 in control group respectively. Conclusion: 2-ME combined with radiotherapy has significant inhibition on the growth of liver metastases. Angiogenesis inhibition is one of the mechanisms of its efficiency. (authors)

  16. Mouse models in liver cancer research: A review of current literature

    Science.gov (United States)

    Leenders, Martijn WH; Nijkamp, Maarten W; Rinkes, Inne HM Borel

    2008-01-01

    Primary liver cancer remains one of the most lethal malignancies worldwide. Due to differences in prevalence of etiological factors the incidence of primary liver cancer varies among the world, with a peak in East-Asia. As this disease is still lethal in most of the cases, research has to be done to improve our understanding of the disease, offering insights for possible treatment options. For this purpose, animal models are widely used, especially mouse models. In this review, we describe the different types of mouse models used in liver cancer research, with emphasis on genetically engineered mice used in this field. We focus on hepatocellular carcinoma (HCC), as this is by far the most common type of primary liver cancer, accounting for 70%-85% of cases. PMID:19058325

  17. Quantification of iron in the presence of calcium with dual-energy computed tomography (DECT) in an ex vivo porcine plaque model

    International Nuclear Information System (INIS)

    Wang Jia; Duan Xinhui; Leng Shuai; Yu Lifeng; McCollough, Cynthia H; Garg, Nitin; Liu Yu; Kantor, Birgit; Ritman, Erik L

    2011-01-01

    Iron deposits secondary to microbleeds often co-exist with calcium in coronary plaques. The purpose of this study was to quantify iron in the presence of calcium in an ex vivo porcine arterial plaque model using a clinical dual-energy CT (DECT) scanner. A material decomposition method to quantify the mass fractions of iron and calcium within a mixture using DECT was developed. Mixture solutions of known iron and calcium concentrations were prepared to calibrate and validate the DECT-based algorithm. Simulated plaques with co-existing iron and calcium were created by injecting the mixture solutions into the vessel wall of porcine carotid arteries and aortas. These vessel regions were harvested and scanned using a clinical DECT system and iron mass fraction was calculated for each sample. Iron- and calcium-specific staining was conducted on 5 µm thick histological sections of vessel samples to confirm the co-existence of iron and calcium in the simulated plaques. The proposed algorithm accurately quantified iron and calcium amounts in mixture solutions. Maps of iron mass fraction of 60 artery segments were obtained from CT images at two energies. The sensitivity for detecting the presence of iron was 83% and the specificity was 92% using a threshold at an iron mass fraction of 0.25%. Histological analysis confirmed the co-localization of iron and calcium within the simulated plaques. Iron quantification in the presence of calcium was feasible in excised arteries at an iron mass fraction of around 1.5% or higher using current clinical DECT scanners.

  18. Evaluation of standardized porcine bone models to test primary stability of dental implants, using biomechanical tests and Micro-CT. An in vitro pilot study

    Directory of Open Access Journals (Sweden)

    C. Delmondes Freitas Dantas

    2015-06-01

    Full Text Available Aim This study evaluated a new porcine bone model to test the primary stability of different implants, analyzing Micro-CT, insertion torque, and pull-out strength. Materials and methods Bone cylinders were prepared from porcine bone and separated into 2 groups: 10 high density bone cylinders (HDB, and 10 low density bone cylinders (LDB. Then, 3D pre-implant analyses were performed, evaluating tridimensional bone density (ratio of trabecular bone volume and total tomographic volume, BV/TV, trabecular separation; percentage of closed pores; percentage of open pores; percentage of total porosity, in 3 bone levels (L1 bone volume corresponding to the internal part of the threads; L2 corresponding to the area between 0 to 0.5 mm from the end of threads; L3 corresponding to the area between 0.5 to 1.5 mm from the end of threads. Twenty implants of two different macrostructures were inserted in the bone cylinders, and divided into 4 groups (5 implants each: Group 1, e-Fix HE implant placed in HDB cylinder; Group 2, e-Fix HE implant in LDB cylinder; Group 3, e-Fix HE Silver implant placed in HDB cylinder; Group 4, e-Fix HE Silver implant in LDB cylinder. The insertion torque was recorded and bone cylinders were re-evaluated by Micro-CT (post-implant analysis. Then a pull-out strength test was performed. Results 3D analysis showed that pre- and post-implants intra-groups evaluation had statistically significant differences in Group 3 and 4, for all tomographic parameters assessed. Group 3 showed the best values for biomechanical tests (Friedman Test, p<0.05. Conclusion This methodology can produce standardized bone cylinders of high and low bone density, in which different implant designs are able to promote different effects, evidenced by biomechanical and image analysis.

  19. Corneal-protective effects of an artificial tear containing sodium hyaluronate and castor oil on a porcine short-term dry eye model.

    Science.gov (United States)

    Hasegawa, Takashi; Amako, Hideki; Yamamoto, Takeshi; Tazawa, Mariko; Sakamoto, Yuji

    2014-09-01

    The corneal-protective effects of an artificial tear containing sodium hyaluronate (SH) and castor oil (CO) were evaluated on a porcine short-term dry eye model. Fresh porcine eyes with an intact cornea were treated with an artificial tear of saline, SH solution (0.1%, 0.5% or 1%), CO solution (0.5%, 1% or 5%) or a mixture solution containing 0.5% SH and 1% CO and then desiccated for 60, 90 or 180 min. To assess corneal damage, the eyes were stained with methylene blue (MB) or lissamine green (LG). The staining score of MB, absorbance of MB extracted from the cornea and staining density of LG increased significantly with increasing desiccation time in untreated and all artificial tear-treated eyes, although there were no significant differences in staining scores and absorbance of MB between eyes treated continuously with saline and 1% SH-treated ones at 60 and 90 min of desiccation or the mixture-treated eyes at 60 min of desiccation. No significant differences in the staining density of LG were also found between continuous saline-treated eyes and ones desiccated for 60 min and treated with 1% SH and the mixture. Mild cytoplasmic vacuolations were histopathologically observed in the basal and wing cells in eyes desiccated for 60 min and treated with 1% SH and the mixture. The mixture solution containing 0.5% SH and 1% CO has protective effects against corneal desiccation similar to those of 1% SH and would be helpful as an artificial tear.

  20. Magnetic resonance elastography of the lung parenchyma in an in situ porcine model with a noninvasive mechanical driver: correlation of shear stiffness with trans-respiratory system pressures.

    Science.gov (United States)

    Mariappan, Yogesh K; Kolipaka, Arunark; Manduca, Armando; Hubmayr, Rolf D; Ehman, Richard L; Araoz, Philip; McGee, Kiaran P

    2012-01-01

    Quantification of the mechanical properties of lung parenchyma is an active field of research due to the association of this metric with normal function, disease initiation and progression. A phase contrast MRI-based elasticity imaging technique known as magnetic resonance elastography is being investigated as a method for measuring the shear stiffness of lung parenchyma. Previous experiments performed with small animals using invasive drivers in direct contact with the lungs have indicated that the quantification of lung shear modulus with (1) H based magnetic resonance elastography is feasible. This technique has been extended to an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. This approach was tested to measure the change in parenchymal stiffness as a function of airway opening pressure (P(ao) ) in 10 adult pigs. In all animals, shear stiffness was successfully quantified at four different P(ao) values. Mean (±STD error of mean) pulmonary parenchyma density corrected stiffness values were calculated to be 1.48 (±0.09), 1.68 (±0.10), 2.05 (±0.13), and 2.23 (±0.17) kPa for P(ao) values of 5, 10, 15, and 20 cm H2O, respectively. Shear stiffness increased with increasing P(ao) , in agreement with the literature. It is concluded that in an in situ porcine lung shear stiffness can be quantitated with (1) H magnetic resonance elastography using a noninvasive mechanical driver and that it is feasible to measure the change in shear stiffness due to change in P(ao) . Copyright © 2011 Wiley-Liss, Inc.

  1. The Hepatoprotection Provided by Taurine and Glycine against Antineoplastic Drugs Induced Liver Injury in an Ex Vivo Model of Normothermic Recirculating Isolated Perfused Rat Liver

    Directory of Open Access Journals (Sweden)

    Reza Heidari

    2016-03-01

    Full Text Available Taurine (2-aminoethane sulfonic acid is a non-protein amino acid found in high concentration in different tissues. Glycine (Amino acetic acid is the simplest amino acid incorporated in the structure of proteins. Several investigations indicate the hepatoprotective properties of these amino acids. On the other hand, antineoplastic agents-induced serum transaminase elevation and liver injury is a clinical complication. The current investigation was designed to screen the possible hepatoprotective properties of taurine and glycine against antineoplastic drugs-induced hepatic injury in an ex vivo model of isolated perfused rat liver. Rat liver was perfused with different concentration (10 μM, 100 μM and 1000 μM of antineoplastic drugs (Mitoxantrone, Cyclophosphamide, Cisplatin, 5 Fluorouracil, Doxorubicin and Dacarbazine via portal vein. Taurine and glycine were administered to drug-treated livers and liver perfusate samples were collected for biochemical measurements (ALT, LDH, AST, and K+. Markers of oxidative stress (reactive oxygen species formation, lipid peroxidation, total antioxidant capacity and glutathione were also assessed in liver tissue. Antineoplastic drugs caused significant pathological changes in perfusate biochemistry. Furthermore, markers of oxidative stress were significantly elevated in drug treated livers. It was found that taurine (5 and 10 mM and glycine (5 and 10 mM administration significantly mitigated the biomarkers of liver injury and attenuated drug induced oxidative stress. Our data indicate that taurine and glycine supplementation might help as potential therapeutic options to encounter anticancer drugs-induced liver injury.

  2. Radiofrequency Ablation (RFA): Development of a Flow Model for Bovine Livers for Extensive Bench Testing

    International Nuclear Information System (INIS)

    Lubienski, Andreas; Bitsch, Rudi G.; Lubienski, Katrin; Kauffmann, Guenter; Duex, Markus

    2006-01-01

    Purpose. To develop a flow model for bovine livers for extensive bench testing of technical improvements or procedure-related developments of radiofrequency ablation excluding animal experiments. Methods. The perfusion of bovine livers directly from the slaughterhouse was simulated in a liver perfusion tank developed for the experimental work. The liver perfusion medium used was a Tyrode solution prepared in accordance with physiologic criteria (as for liver transplants) which was oxygenated by an oxygenator and heated to 36.5 deg. C. Portal vein circulation was regulated via a flow- and pressure-controlled pump and arterial circulation using a dialysis machine. Flow rate and pressure were adjusted as for the physiology of a human liver converted to bovine liver conditions. The fluid discharged from the liver was returned into the perfusion system through the vena cava. Extendable precision swivel arms with the radiofrequency probe attached were mounted on the liver perfusion tank. RFA was conducted with the RF3000 generator and a 2 cm LeVeen needle (Boston Scientific, Ratingen, Germany) in a three-dimensional grid for precise localization of the generated thermolesions. Results. Four bovine livers weighing 8.4 ± 0.4 kg each were prepared, connected to the perfusion system, and consecutively perfused for the experiments. Mean arterial flow was 569 ± 43 ml/min, arterial pressure 120 mmHg, portovenous flow 1440 ± 305 ml/min, and portal pressure 10 mmHg. Macroscopic evaluation after the experiments revealed no thrombi within the hepatic vessels. A total of 136 RF thermolesions were generated with an average number of 34 per liver. Mean RF duration was 2:59 ± 2:01 min:sec with an average baseline impedance of 28.2 ± 3.4 ohms. The mean diameter of the thermolesions along the puncture channel was 22.98 ± 4.34 mm and perpendicular to the channel was 23.27 ± 4.82 mm. Conclusion. Extracorporeal perfusion of bovine livers with consecutive standardized RF ablation was

  3. Effects of aspirin and enoxaparin in a rat model of liver fibrosis.

    Science.gov (United States)

    Li, Chen-Jie; Yang, Zhi-Hui; Shi, Xiao-Liu; Liu, De-Liang

    2017-09-21

    To examine the effects of aspirin and enoxaparin on liver function, coagulation index and histopathology in a rat model of liver fibrosis. METHODS Forty-five male Sprague-Dawley rats were randomly divided into the control group (n = 5) and model group (n = 40). Thioacetamide (TAA) was used to induce liver fibrosis in the model group. TAA-induced fibrotic rats received TAA continuously (n = 9), TAA + low-dose aspirin (n = 9), TAA + high-dose aspirin (n = 9) or TAA + enoxaparin (n = 9) for 4 wk. All rats were euthanized after 4 wk, and both hematoxylin-eosin and Masson staining were performed to observe pathological changes in liver tissue. Liver fibrosis was assessed according to the METAVIR score. Compared with untreated cirrhotic controls, a significant improvement in fibrosis grade was observed in the low-dose aspirin, high-dose aspirin and enoxaparin treated groups, especially in the high-dose aspirin treated group. Alanine aminotransferase and total bilirubin were higher, albumin was lower and both prothrombin time and international normalized ratio were prolonged in the four treatment groups compared to controls. No significant differences among the four groups were observed. Aspirin and enoxaparin can alleviate liver fibrosis in this rat model.

  4. Porcine SLITRK1

    DEFF Research Database (Denmark)

    Larsen, Knud Erik; Momeni, Jamal; Farajzadeh, Leila

    2014-01-01

    The membrane protein SLITRK1 functions as a developmentally regulated stimulator of neurite outgrowth and variants in this gene have been implicated in Tourette syndrome. In the current study we have cloned and characterized the porcine SLITRK1 gene. The genomic organization of SLITRK1 lacks...

  5. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  6. Administration of intrapulmonary sodium polyacrylate to induce lung injury for the development of a porcine model of early acute respiratory distress syndrome.

    Science.gov (United States)

    Henderson, William R; Barnbrook, Julian; Dominelli, Paolo B; Griesdale, Donald Eg; Arndt, Tara; Molgat-Seon, Yannick; Foster, Glen; Ackland, Gareth L; Xu, James; Ayas, Najib T; Sheel, Andrew W

    2014-12-01

    The loss of alveolar epithelial and endothelial integrity is a central component in acute respiratory distress syndrome (ARDS); however, experimental models investigating the mechanisms of epithelial injury are lacking. The purpose of the present study was to design and develop an experimental porcine model of ARDS by inducing lung injury with intrapulmonary administration of sodium polyacrylate (SPA). The present study was performed at the Centre for Comparative Medicine, University of British Columbia, Vancouver, British Columbia. Human alveolar epithelial cells were cultured with several different concentrations of SPA; a bioluminescence technique was used to assess cell death associated with each concentration. In the anesthetized pig model (female Yorkshire X pigs (n = 14)), lung injury was caused in 11 animals (SPA group) by injecting sequential aliquots (5 mL) of 1% SPA gel in aqueous solution into the distal airway via a rubber catheter through an endotracheal tube. The SPA was dispersed throughout the lungs by manual bag ventilation. Three control animals (CON group) underwent all experimental procedures and measurements with the exception of SPA administration. The mean (± SD) ATP concentration after incubation of human alveolar epithelial cells with 0.1% SPA (0.92 ± 0.27 μM/well) was approximately 15% of the value found for the background control (6.30 ± 0.37 μM/well; p congestion of the dorsal lung lobes in SPA-treated animals, with light-microscopy evidence of bronchiolar and alveolar spaces filled with neutrophilic infiltrate, proteinaceous debris, and fibrin deposition. These findings were absent in animals in the CON group. Electron microscopy of lung tissue from SPA-treated animals revealed injury to the alveolar epithelium and basement membranes, including intra-alveolar neutrophils and fibrin on the alveolar surface and intravascular fibrin (microthrombosis). In this particular porcine model, the nonimmunogenic polymer SPA

  7. Human Adipose Tissue Derived Stem Cells Promote Liver Regeneration in a Rat Model of Toxic Injury

    Directory of Open Access Journals (Sweden)

    Eva Koellensperger

    2013-01-01

    Full Text Available In the light of the persisting lack of donor organs and the risks of allotransplantations, the possibility of liver regeneration with autologous stem cells from adipose tissue (ADSC is an intriguing alternative. Using a model of a toxic liver damage in Sprague Dawley rats, generated by repetitive intraperitoneal application of retrorsine and allyl alcohol, the ability of human ADSC to support the restoration of liver function was investigated. A two-thirds hepatectomy was performed, and human ADSC were injected into one remaining liver lobe in group 1 (n = 20. Injection of cell culture medium performed in group 2 (n = 20 served as control. Cyclosporine was applied to achieve immunotolerance. Blood samples were drawn weekly after surgery to determine liver-correlated blood values. Six and twelve weeks after surgery, animals were sacrificed and histological sections were analyzed. ADSC significantly raised postoperative albumin (P < 0.017, total protein (P < 0.031, glutamic oxaloacetic transaminase (P < 0.001, and lactate dehydrogenase (P < 0.04 levels compared to injection of cell culture medium alone. Transplanted cells could be found up to twelve weeks after surgery in histological sections. This study points towards ADSC being a promising alternative to hepatocyte or liver organ transplantation in patients with severe liver failure.

  8. Sequence conservation between porcine and human LRRK2

    DEFF Research Database (Denmark)

    Larsen, Knud; Madsen, Lone Bruhn

    2009-01-01

     Leucine-rich repeat kinase 2 (LRRK2) is a member of the ROCO protein superfamily (Ras of complex proteins (Roc) with a C-terminal Roc domain). Mutations in the LRRK2 gene lead to autosomal dominant Parkinsonism. We have cloned the porcine LRRK2 cDNA in an attempt to characterize conserved...... and expression patterns are conserved across species. The porcine LRRK2 gene was mapped to chromosome 5q25. The results obtained suggest that the LRRK2 gene might be of particular interest in our attempt to generate a transgenic porcine model for Parkinson's disease...

  9. Inhibitory effect of gene combination in a mouse model of colon cancer with liver metastasis.

    Science.gov (United States)

    DU, Tong; Niu, Hongxin

    2014-09-01

    The aim of the present study was to establish an animal liver metastasis model with human colon cancer and investigate the inhibitory effect of the wild type (WT) p53 gene combined with thymidine kinase/ganciclovir (TK/GCV) and cytosine deaminase/5-fluorocytosine (CD/5-FC) systems on liver metastasis of colon cancer. A nude mouse liver metastasis model with human colon cancer was established via a spleen cultivation method. A total of 32 nude mice were randomly divided into four groups, each group with eight mice. Group 1 mice received splenic injections of SW480 cells (control group), while group 2 mice were injected with SW480/p53 cells in the spleen. Group 3 mice were administered splenic injections of SW480/TK-CD cells, and GCV and 5-FC were injected into the abdominal cavity. Finally, group 4 mice received splenic injections of SW480/p53 cells mixed in equal proportion with SW480/TK-CD cells, as well as GCV and 5-FC injections in the abdominal cavity. These cells described were constructed in our laboratory and other laboratories. The number of liver metastatic tumors, the liver metastasis rate, conventional pathology, electron microscopy and other indicators in the nude mice of each group were compared and observed. The nude mouse liver metastasis model with human colon cancer was successfully established; the liver metastasis rate of the control group was 100%. The results demonstrated that the rate of liver metastasis in the nude mice in each treatment group decreased, as well as the average number of liver metastatic tumors. Furthermore, the effect of the treatment group with genetic combination (group 4) was the most effective, demonstrating that WTp53 had a synergistic effect with TK/GCV and CD/5-FC. Therefore, the present study successfully established a mouse model of liver metastasis with colon cancer by injecting human colon cancer cells in the spleen. Combined gene therapy was shown to have a synergistic effect, which effectively inhibited the

  10. Medium chain triglycerides dose-dependently prevent liver pathology in a rat model of nonalcoholic fatty liver disease

    Science.gov (United States)

    Obesity is often associated with a cluster of increased health risks collectively known as "Metabolic Syndrome" (MS). MS is often accompanied by development of fatty liver. Sometimes fatty liver results in damage leading to reduced liver function, and need for a transplant. This condition is known...

  11. Ex vivo Porcine Model to Measure pH Dependence of gagCEST in the Inter-Vertebral Disc

    Science.gov (United States)

    Melkus, Gerd; Grabau, Michelle; Karampinos, Dimitrios C.; Majumdar, Sharmila

    2013-01-01

    Purpose Studies have linked low pH and loss of glycosaminoglycan (GAG) in the intervertebral discs (IVDs) of patients with discogenic back pain. The purpose of the present study is to determine whether the chemical exchange saturation transfer (CEST) effect of GAG (gagCEST) is pH-dependent and whether it can be used to detect pH changes in IVD specimens. Iopromide, a FDA approved agent for CT/X-Ray, was also evaluated as a pH-sensitive CEST probe to explore the agents’ potential to measure IVD pH. Methods The pH dependency of the CEST effect of chondroitin sulfate (containing GAG) and Iopromide phantoms was investigated at 7 T. Z-spectra from porcine IVD specimens were acquired before and after manipulating the pH with sodium lactate. Iopromide was injected into the specimens and the calibration curve was used to determine the pH status. Results Chondroitin sulfate showed a non-linear dependence of gagCEST effect with pH and gagCEST signal differences were detected in the specimens. The CEST effect of Iopromide resulted in a sigmoidal relation with pH and was used to measure pH. Conclusion gagCEST is sensitive to pH and enables investigation of the IVD pH status. Iopromide CEST is independent of the local GAG concentration and has the potential for measuring pH in the IVD. PMID:23818244

  12. Mouse precision-cut liver slices as an ex vivo model to study idiosyncratic drug-induced liver injury.

    Science.gov (United States)

    Hadi, Mackenzie; Chen, Yixi; Starokozhko, Viktoriia; Merema, Marjolijn T; Groothuis, Geny M M

    2012-09-17

    Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in increased toxicity (inflammatory stress hypothesis). Aiming to develop a robust ex vivo screening method to study inflammatory stress-related IDILI mechanisms and to find biomarkers that can detect or predict IDILI, mouse precision-cut liver slices (mPCLS) were coincubated for 24 h with IDILI-related drugs and lipopolysaccharide. Lipopolysaccharide exacerbated ketoconazole (15 μM) and clozapine (45 μM) toxicity but not their non-IDILI-related comparators, voriconazole (1500 μM) and olanzapine (45 μM). However, the other IDILI-related drugs tested [diclofenac (200 μM), carbamazepine (400 μM), and troglitazone (30 μM)] did not cause synergistic toxicity with lipopolysaccharide after 24 h of incubation. Lipopolysaccharide further decreased the reduced glutathione levels caused by ketoconazole or clozapine in mPCLS after 24 h of incubation, which was not the case for the other drugs. Lipopolysaccharide significantly increased nitric oxide (NO), cytokine, and chemokine release into the mPCLS media, while the treatment with the drugs alone did not cause any substantial change. All seven drugs drastically reduced lipopolysaccharide-induced NO production. Interestingly, only ketoconazole and clozapine increased the lipopolysaccharide-induced granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. Pilot experiments showed that diclofenac and troglitazone, but not carbamazepine, demonstrated synergistic toxicity with lipopolysaccharide after a longer incubation of 48 h in mPCLS. In conclusion, we have developed an ex vivo model to detect inflammatory stress-related liver toxicity and identified ketoconazole, clozapine

  13. Inhibition of p53 attenuates steatosis and liver injury in a mouse model of non-alcoholic fatty liver disease.

    Science.gov (United States)

    Derdak, Zoltan; Villegas, Kristine A; Harb, Ragheb; Wu, Annie M; Sousa, Aryanna; Wands, Jack R

    2013-04-01

    p53 and its transcriptional target miRNA34a have been implicated in the pathogenesis of fatty liver. We tested the efficacy of a p53 inhibitor, pifithrin-α p-nitro (PFT) in attenuating steatosis, associated oxidative stress and apoptosis in a murine model of non-alcoholic fatty liver disease (NAFLD). C57BL/6 mice were fed a high-fat (HFD) or control diet for 8 weeks; PFT or DMSO (vehicle) was administered three times per week. Markers of oxidative stress and apoptosis as well as mediators of hepatic fatty acid metabolism were assessed by immunohistochemistry, Western blot, real-time PCR, and biochemical assays. PFT administration suppressed HFD-induced weight gain, ALT elevation, steatosis, oxidative stress, and apoptosis. PFT treatment blunted the HFD-induced upregulation of miRNA34a and increased SIRT1 expression. In the livers of HFD-fed, PFT-treated mice, activation of the SIRT1/PGC1α/PPARα axis increased the expression of malonyl-CoA decarboxylase (MLYCD), an enzyme responsible for malonyl-CoA (mCoA) degradation. Additionally, the SIRT1/LKB1/AMPK pathway (upstream activator of MLYCD) was promoted by PFT. Thus, induction of these two pathways by PFT diminished the hepatic mCoA content by enhancing MLYCD expression and function. Since mCoA inhibits carnitine palmitoyltransferase 1 (CPT1), the decrease of hepatic mCoA in the PFT-treated, HFD-fed mice increased CPT1 activity, favored fatty acid oxidation, and decreased steatosis. Additionally, we demonstrated that PFT abrogated steatosis and promoted MLYCD expression in palmitoleic acid-treated human HepaRG cells. The p53 inhibitor PFT diminished hepatic triglyceride accumulation and lipotoxicity in mice fed a HFD, by depleting mCoA and favoring the β-oxidation of fatty acids. Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  14. Influence of matrix nature on the functional efficacy of biomedical cell product for the regeneration of damaged liver (experimental model of acute liver failure

    Directory of Open Access Journals (Sweden)

    S. V. Gautier

    2017-01-01

    Full Text Available Aim. A comparative analysis of the functional efficacy of biomedical cell products (BMCP for the regeneration of damaged liver based on biopolymer scaffolded porous and hydrogel matrices was performed on the experimental model of acute liver failure. Materials and methods. Matrices allowed for clinical use were employed for BMCP in the form of a sponge made from biopolymer nanostructured composite material (BNCM based on a highly purified bacterial copolymers of poly (β-hydroxybutyrate-co-β-oxyvalerate and polyethylene glycol and a hydrogel matrix from biopolymer microheterogeneous collagen-containing hydrogel (BMCH. Cellular component of BMCP was represented by liver cells and multipotent mesenchymal bone marrow stem cells. The functional efficacy of BMCP for the regeneration of damaged liver was evaluated on the experimental model of acute liver failure in Wistar rats (n = 40 via biochemical, morphological, and immunohistochemical methods. Results. When BMCP was implanted to regenerate the damaged liver on the basis of the scaffolded BNCM or hydrogel BMCH matrices, the lethality in rats with acute liver failure was absent; while in control it was 66.6%. Restoration of the activity of cytolytic enzyme levels and protein-synthetic liver function began on day 9 after modeling acute liver failure, in contrast to the control group, where recovery occurred only by days 18–21. Both matrices maintained the viability and functional activity of liver cells up to 90 days with the formation of blood vessels in BMCP. The obtained data confirm that scaffolded BNCM matrix and hydrogel BMCH matrix retain for a long time (up to 90 days the vital activity of the adherent cells in the BMCP composition, which allows using them to correct acute liver failure. At the same time, hydrogel matrix due to the presence of bioactive components contributes to the creation of the best conditions for adhesion and cell activity which accelerate the regeneration processes

  15. Hemodynamic effects of spiral ePTFE prosthesis compared with standard arteriovenous graft in a carotid to jugular vein porcine model.

    Science.gov (United States)

    Jahrome, Ommid K; Hoefer, Imo; Houston, Graeme J; Stonebridge, Peter A; Blankestijn, Peter J; Moll, Frans L; de Borst, Gert J

    2011-01-01

    The primary patency rate of arteriovenous (AV) grafts is limited by distal venous anastomosis stenosis or occlusion due to intimal hyperplasia associated with distal graft turbulence. The normal blood flow in native arteries is spiral laminar flow. Standard vascular grafts do not produce spiral laminar flow at the distal anastomosis. Vascular grafts which induce a spiral laminar flow distally result in lower turbulence, particularly near the vessel wall. This initial study compares the hemodynamic effects of a spiral flow-inducing graft and a standard graft in a new AV carotid to jugular vein crossover graft porcine model. Four spiral flow grafts and 4 control grafts were implanted from the carotid artery to the contralateral jugular vein in 4 pigs. Two animals were terminated after 48 hours and 2 at 14 days. Graft patency was assessed by selective catheter digital angiography, and the flow pattern was assessed by intraoperative flow probe and color Doppler ultrasound (CDU) measurements. The spiral grafts were also assessed at enhanced flow rates using an external roller pump to simulate increased flow rates that may occur during dialysis using a standard dialysis needle cannulation. The method increased the flow rate through the graft by 660 ml/min. The graft distal anastomotic appearances were evaluated by explant histopathology. All grafts were patent at explantation with no complications. All anastomoses were found to be wide open and showed no significant angiographic stenosis at the distal anastomosis in both spiral and control grafts. CDU examinations showed a spiral flow pattern in the spiral graft and double helix pattern in the control graft. No gross histopathological effects were seen in either spiral or control grafts. This porcine model is robust and allows hemodynamic flow assessment up to 14 days postimplantation. The spiral flow-inducing grafts produced and maintained spiral flow at baseline and enhanced flow rates during dialysis needle

  16. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    International Nuclear Information System (INIS)

    Wu, Weibin; Zhu, Bo; Peng, Xiaomin; Zhou, Meiling; Jia, Dongwei; Gu, Jianxin

    2014-01-01

    Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients

  17. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    Energy Technology Data Exchange (ETDEWEB)

    Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

    2014-02-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

  18. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    International Nuclear Information System (INIS)

    Yannam, Govardhana Rao; Han, Bing; Setoyama, Kentaro; Yamamoto, Toshiyuki; Ito, Ryotaro; Brooks, Jenna M.; Guzman-Lepe, Jorge; Galambos, Csaba; Fong, Jason V.; Deutsch, Melvin; Quader, Mubina A.; Yamanouchi, Kosho; Kabarriti, Rafi; Mehta, Keyur; Soto-Gutierrez, Alejandro

    2014-01-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury

  19. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weibin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China); Zhu, Bo; Peng, Xiaomin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Jia, Dongwei, E-mail: jiadongwei@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China)

    2014-01-03

    Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

  20. Sildenafil Protects against Myocardial Ischemia-Reperfusion Injury Following Cardiac Arrest in a Porcine Model: Possible Role of the Renin-Angiotensin System

    Science.gov (United States)

    Wang, Guoxing; Zhang, Qian; Yuan, Wei; Wu, Junyuan; Li, Chunsheng

    2015-01-01

    Sildenafil, a phosphodiesterase-5 inhibitor sold as Viagra, is a cardioprotector against myocardial ischemia/reperfusion (I/R) injury. Our study explored whether sildenafil protects against I/R-induced damage in a porcine cardiac arrest and resuscitation (CAR) model via modulating the renin-angiotensin system. Male pigs were randomly divided to three groups: Sham group, Saline group, and sildenafil (0.5 mg/kg) group. Thirty min after drug infusion, ventricular fibrillation (8 min) and cardiopulmonary resuscitation (up to 30 min) was conducted in these animals. We found that sildenafil ameliorated the reduced cardiac function and improved the 24-h survival rate in this model. Sildenafil partly attenuated the increases of plasma angiotensin II (Ang II) and Ang (1–7) levels after CAR. Sildenafil also decreased apoptosis and Ang II expression in myocardium. The increases of expression of angiotensin-converting-enzyme (ACE), ACE2, Ang II type 1 receptor (AT1R), and the Ang (1–7) receptor Mas in myocardial tissue were enhanced after CAR. Sildenafil suppressed AT1R up-regulation, but had no effect on ACE, ACE2, and Mas expression. Sildenafilfurther boosted the upregulation of endothelial nitric oxide synthase (eNOS), cyclic guanosine monophosphate (cGMP) and inducible nitric oxide synthase(iNOS). Collectively, our results suggest that cardioprotection of sildenafil in CAR model is accompanied by an inhibition of Ang II-AT1R axis activation. PMID:26569234

  1. Sildenafil Protects against Myocardial Ischemia-Reperfusion Injury Following Cardiac Arrest in a Porcine Model: Possible Role of the Renin-Angiotensin System

    Directory of Open Access Journals (Sweden)

    Guoxing Wang

    2015-11-01

    Full Text Available Sildenafil, a phosphodiesterase-5 inhibitor sold as Viagra, is a cardioprotector against myocardial ischemia/reperfusion (I/R injury. Our study explored whether sildenafil protects against I/R-induced damage in a porcine cardiac arrest and resuscitation (CAR model via modulating the renin-angiotensin system. Male pigs were randomly divided to three groups: Sham group, Saline group, and sildenafil (0.5 mg/kg group. Thirty min after drug infusion, ventricular fibrillation (8 min and cardiopulmonary resuscitation (up to 30 min was conducted in these animals. We found that sildenafil ameliorated the reduced cardiac function and improved the 24-h survival rate in this model. Sildenafil partly attenuated the increases of plasma angiotensin II (Ang II and Ang (1–7 levels after CAR. Sildenafil also decreased apoptosis and Ang II expression in myocardium. The increases of expression of angiotensin-converting-enzyme (ACE, ACE2, Ang II type 1 receptor (AT1R, and the Ang (1–7 receptor Mas in myocardial tissue were enhanced after CAR. Sildenafil suppressed AT1R up-regulation, but had no effect on ACE, ACE2, and Mas expression. Sildenafilfurther boosted the upregulation of endothelial nitric oxide synthase (eNOS, cyclic guanosine monophosphate (cGMP and inducible nitric oxide synthase(iNOS. Collectively, our results suggest that cardioprotection of sildenafil in CAR model is accompanied by an inhibition of Ang II-AT1R axis activation.

  2. Gradient-dependent release of the model drug TRITC-dextran from FITC-labeled BSA hydrogel nanocarriers in the hair follicles of porcine ear skin.

    Science.gov (United States)

    Tran, Ngo Bich Nga Nathalie; Knorr, Fanny; Mak, Wing Cheung; Cheung, Kwan Yee; Richter, Heike; Meinke, Martina; Lademann, Jürgen; Patzelt, Alexa

    2017-07-01

    Hair follicle research is currently focused on the development of drug-loaded nanocarriers for the targeting of follicular structures in the treatment of skin and hair follicle-related disorders. In the present study, a dual-label nanocarrier system was implemented in which FITC-labeled BSA hydrogel nanocarriers loaded with the model drug and dye TRITC-dextran were applied topically to porcine ear skin. Follicular penetration and the distribution of both dyes corresponding to the nanocarriers and the model drug in the follicular ducts subsequent to administration to the skin were investigated using confocal laser scanning microscopy. The release of TRITC-dextran from the particles was induced by washing of the nanocarriers, which were kept in a buffer containing TRITC-labeled dextran to balance out the diffusion of the dextran during storage, thereby changing the concentration gradient. The results showed a slightly but statistically significantly deeper follicular penetration of fluorescent signals corresponding to TRITC-dextran as opposed to fluorescence corresponding to the FITC-labeled particles. The different localizations of the dyes in the cross-sections of the skin samples evidenced the release of the model drug from the labeled nanoparticles. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Expression and localization of regenerating gene I in a rat liver regeneration model

    International Nuclear Information System (INIS)

    Wang Jingshu; Koyota, Souichi; Zhou, Xiaoping; Ueno, Yasuharu; Ma Li; Kawagoe, Masami; Koizumi, Yukio; Okamoto, Hiroshi; Sugiyama, Toshihiro

    2009-01-01

    Regenerating gene (Reg) I has been identified as a regenerative/proliferative factor for pancreatic islet cells. We examined Reg I expression in the regenerating liver of a rat model that had been administered 2-acetylaminofluorene and treated with 70% partial hepatectomy (2-AAF/PH model), where hepatocyte and cholangiocyte proliferation was suppressed and the hepatic stem cells and/or hepatic progenitor cells were activated. In a detailed time course study of activation of hepatic stem cells in the 2-AAF/PH model, utilizing immunofluorescence staining with antibodies of Reg I and other cell-type-specific markers, we found that Reg I-expressing cells are present in the bile ductules and increased during regeneration. Reg I-expressing cells were colocalized with CK19, OV6, and AFP. These results demonstrate that Reg I is significantly upregulated in the liver of the 2-AAF/PH rat model, accompanied by the formation of bile ductules during liver regeneration.

  4. Porcine head response to blast.

    Science.gov (United States)

    Shridharani, Jay K; Wood, Garrett W; Panzer, Matthew B; Capehart, Bruce P; Nyein, Michelle K; Radovitzky, Raul A; Bass, Cameron R 'dale'

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300-2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G's and were well correlated with peak incident overpressure (R(2) = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  5. A novel animal model for in vivo study of liver cancer metastasis

    Institute of Scientific and Technical Information of China (English)

    Shinsuke Fujiwara; Katsutoshi Yoshizato; Hikaru Fujioka; Chise Tateno; Ken Taniguchi; Masahiro Ito; Hiroshi Ohishi; Rie Utoh; Hiromi Ishibashi; Takashi Kanematsu

    2012-01-01

    AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein (AFP)-producing human gastric cancer cells (h-GCCs) and h-hepatocytes as donor cells in a transgenic mouse line expressing urokinase-type plasminogen activator (uPA) driven by the albumin enhancer/promoter crossed with a severe combined immunodeficient (SCID) mouse line (uPA/SCID mice).Host mice were divided into two groups (A and B).Group A mice were transplanted with h-GCCs alone,and group B mice were transplanted with h-GCCs and h-hepatocytes together.The replacement index (RI),which is the ratio of transplanted h-GCCs and h-hepatocytes that occupy the examined area of a histological section,was estimated by measuring h-AFP and h-albumin concentrations in sera,respectively,as well as by immunohistochemical analyses of h-AFP and human cytokeratin 18 in histological sections.RESULTS:The h-GCCs successfully engrafted,repopulated,and colonized the livers of mice in group A (RI =22.0% ± 2.6%).These mice had moderately differentiated adenocarcinomatous lesions with disrupted glandular structures,which is a characteristics feature of gastric cancers.The serum h-AFP level reached 211.0 ± 142.2 g/mL (range,7.1-324.2 g/mL).In group B mice,the h-GCCs and h-hepatocytes independently engrafted,repopulated the host liver,and developed colonies (RI =12.0% ± 6.8% and 66.0% ± 12.3%,respectively).h-GCC colonies also showed typical adenocarcinomatous glandular structures around the h-hepatocyte-colonies.These mice survived for the full 56day-study and did not exhibit any metastasis of h-GCCs in the extrahepatic regions during the observational period.The mice with an h-hepatocyte-repopulated liver possessed metastasized h-GCCs and therefore could be a useful humanized liver animal model for studying liver cancer metastasis in vivo.CONCLUSION:A novel animal model of

  6. Promiscuous activity of the LXR antagonist GSK2033 in a mouse model of fatty liver disease

    International Nuclear Information System (INIS)

    Griffett, Kristine; Burris, Thomas P.

    2016-01-01

    The liver X receptor (LXR) functions as a receptor for oxysterols and plays a critical role in the regulation of glucose and lipid metabolism. We recently described a synthetic LXR inverse agonist that displayed efficacy in treatment of hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD). This compound, SR9238, was designed to display liver specificity so as to avoid potential detrimental effects on reverse cholesterol transport in peripheral tissues. Here, we examined the effects of a LXR antagonist/inverse agonist, GSK2033, which displays systemic exposure. Although GSK2033 performed as expected in cell-based models as a LXR inverse agonist, it displayed unexpected activity in the mouse NAFLD model. The expression of lipogenic enzyme genes such as fatty acid synthase and sterol regulatory binding protein 1c were induced rather than suppressed and no effect on hepatic steatosis was found. Further characterization of the specificity of GSK2033 revealed that it displayed a significant degree of promiscuity, targeting a number of other nuclear receptors that could clearly alter hepatic gene expression. - Highlights: • The LXR antagonist GSK2033 suppresses the expression of lipogenic genes FASN and SREBF1 in HepG2 cells. • GSK2033 exhibits sufficient exposure to perform animal experiments targeting the liver. • GSK2033 has fails to suppress hepatic Fasn and Srebf1 expression in an animal model of non-alcoholic fatty liver disease. • GSK2033 may regulate the activity of several nuclear receptors.

  7. Graft tendon slippage with metallic and bioabsorbable interference screws under cyclic load: a biomechanical study in a porcine model

    Directory of Open Access Journals (Sweden)

    Ari Digiácomo Ocampo Moré

    Full Text Available Introduction The rupture of the anterior cruciate ligament (ACL is the most common type of knee injury. Reconstructive surgery is the ‘gold standard’ treatment. During the immediate post-operative period, the fixation of the graft is entirely dependent on the ability of the grafted implant to be secured inside the bone tunnel under the cyclical loads associated with daily tasks. Poor fixation can lead to graft slippage, thus impairing the healing and integration of the graft. The aim of this study was to evaluate the biomechanical performance of tendon graft fixation devices with metallic and bioabsorbable interference screws. Methods Twenty ACL reconstructions were carried out in porcine tibias using deep flexor tendons to fix 9 × 20 mm metallic (n=10 and PLLA 70/30 bioabsorbable screws (n=10. To verify the ability of a construct to resist immediate postoperative (PO rehabilitation protocols for immediate load bearing, a cyclic loading test was applied with 50-250 N of tensile force at 1 Hz for 1000 cycles, and the displacement was measured at 10, 50, 100, 500 and 1000 load cycles to quantify the slippage of the graft during the test. After the cyclic loading test, a single-cycle load-to-failure test was applied. Results The slippage of the graft using metallic screws did not differ (P = 0.616 from that observed when using bioabsorbable screws. Conclusion The results obtained in this experiment indicate that metallic screws may promote a similar amount of graft slippage during low cyclic loading as bioabsorbable screws. Additionally, there was no difference in the biomechanical performance of these two types of screws during high failure loads.

  8. Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model.

    Science.gov (United States)

    Beer, Andreas; Gahleitner, André; Holm, Anders; Birkfellner, Wolfgang; Homolka, Peter

    2007-02-01

    The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self-tapping implants in cancellous bone. In adapted preparation, bone condensation - and thus, insertion torque - is controlled by changing the diameter of the drilling. After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem Mk III implants (3.75 x 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Based on the average torque recorded during implant insertion into the pre-drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw-shaped implant. Thus, using an individualized bone mineralization-dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm(3). The results indicate that using a bone-dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.

  9. Radiofrequency ablation of pancreas and optimal cooling of peripancreatic tissue in an ex-vivo porcine model

    Directory of Open Access Journals (Sweden)

    Michal Crha

    2011-01-01

    Full Text Available Radiofrequency ablation is a possible palliative treatment for patients suffering from pancreatic neoplasia. However, radiofrequency-induced damage to the peripancreatic tissues during pancreatic ablation might cause fatal complications. The aim of this experimental ex vivo study on pigs was to verify ablation protocols and evaluate whether or not the cooling of peripancereatic tissues during pancreatic ablation has any benefit for their protection against thermal injury. Radiofrequency ablation was performed on 52 pancreatic specimens obtained from pigs. During each pancreatic ablation, continuous measurements of the temperature in the portal vein and duodenal lumen were performed. Peripancreatic tissues were either not cooled or were cooled by being submerged in 14 °C water, or by a perfusion of the portal vein and duodenum with 14 °C saline. The effects of variation in target temperature of the ablated area (90 °C and 100 °C, duration of ablation (5 and 10 min and the effect of peripancreatic tissues cooling were studied. We proved that optimal radiofrequency ablation of the porcine pancreas can be reached with the temperature of 90  °C for 5 min in the ablated area. The perfusion of the duodenal and portal vein by 14 °C saline was found to be the most effective cooling method for minimizing damage to the walls. Continuous measurement of temperatures in peripancreatic tissues will provide useful feedback to assist in their protection against thermal injury. This therapy could be used in the treatment of pancreatic tumours.

  10. Porcine circovirus diseases

    Directory of Open Access Journals (Sweden)

    Ristoski Trpe

    2009-05-01

    Full Text Available Porcine circovirus type 2 belongs on the family Circoviridae. This virus family includes small, non-enveloped viruses, with a circular, single-standed DNA genome.This virus causes mainly subclinical infections, but a number of diseases have been linked to it (porcine circovirus diseases, PCVD. The most economically important PCVD is postweaning multisystemic wasting syndrome (PMWS, which mainly affects pigs of 2 to 5 months of age, with progressive wasting, diarrhea and respiratory disorders. Main PMWS lesions are found in lymphoid tissues, which are characterized by lymphocyte depletion with granulomatous (histiocytic and multinucleate giant cell infiltration. PMWS is considered as multifactorial disease, with a number of infectious and non-infectious factors able to act as disease triggering in PCV2 infected pigs. PCVDs are worldwide distributed, and PMWS was diagnosed in Macedonia in 2007.

  11. Multi-state models for bleeding episodes and mortality in liver cirrhosis

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Esbjerg, Sille; Sørensen, Thorkild I.A.

    2000-01-01

    Data from a controlled clinical trial in liver cirrhosis are used to illustrate that multi-state models may be a useful tool in the analysis of data where survival is the ultimate outcome of interest but where intermediate, transient states are identified. We compare models for the marginal survi...

  12. The Effect of Negative Pressure Wound Therapy With Antiseptic Instillation on Biofilm Formation in a Porcine Model of Infected Spinal Instrumentation.

    Science.gov (United States)

    Singh, Devinder P; Gowda, Arvind U; Chopra, Karan; Tholen, Michael; Chang, Sarah; Mavrophilipos, Vasilios; Semsarzadeh, Nina; Rasko, Yvonne; Holton Iii, Luther

    2017-06-01

    This study evaluates the effect of negative pressure wound therapy with antiseptic instillation (NPWTi) in the clearance of infection and biofilm formation in an in vivo model of infected spinal implants compared to traditional treatment modalities. Five pigs underwent titanium rod implantation of their spinous processes followed by injection of 1 x 106 CFUs/100μL of methicillin-resistant Staphylococcus aureus through the fascia at each site. At 1 week postoperatively, an experimental arm of 3 pigs received NPWTi, and a control arm of 2 pigs received wet-to-dry dressings. The persistence of local infection in the experimental group was compared to the control group using tissue cultures. Biofilm development on spinal implants was evaluated using scanning electron microscopy. Mean bacterial count showed a statistical difference between the experimental and the control groups (P < .05). Scanning electron microscopy revealed the presence of uniform biofilm formation across the surface of control group instrumentation, whereas the experimental group showed interrupted areas between biofilm formations. The authors concluded that NPWTi is associated with decreased bacterial load and biofilm formation compared to wet-to-dry dressings in an in vivo porcine model of infected spinal instrumentation.

  13. High regenerative capacity of the liver and irreversible injury of male reproductive system in carbon tetrachloride-induced liver fibrosis rat model.

    Science.gov (United States)

    Bubnov, Rostyslav V; Drahulian, Maria V; Buchek, Polina V; Gulko, Tamara P

    2018-03-01

    Liver fibrosis (LF) is a chronic disease, associated with many collateral diseases including reproductive dysfunction. Although the normal liver has a large regenerative capacity the complications of LF could be severe and irreversible. Hormone and sex-related issues of LF development and interactions with male reproductive have not been finally studied. The aim was to study the reproductive function of male rats in experimental CCl 4 -induced liver fibrosis rat model, and the capability for restoration of both the liver and male reproduction system. Studies were conducted on 20 3-month old Wistar male rats. The experimental animals were injected with freshly prepared 50% olive oil solution of carbohydrate tetrachloride (CCl 4 ). On the 8th week after injection we noted the manifestations of liver fibrosis. The rats were left to self-healing of the liver for 8 weeks. All male rats underwent ultrasound and biopsy of the liver and testes on the 8th and 16th weeks. The male rats were mated with healthy females before CCl 4 injection, after modeling LF on the 8th week, and after self-healing of the liver. Pregnancy was monitored on ultrasound. On the 8th week of experiment we observed ultrasound manifestation of advanced liver fibrosis, including hepatosplenomegaly, portal hypertension. Ultrasound exam of the rat testes showed testicular degeneration, hydrocele, fibrosis, scarring, petrifications, size reduction, and restriction of testicular descent; testes size decreased from 1.24 ± 0.62 ml to 0.61 ± 0.13, p  reproductive system and altering of fertility: the offspring of male rats with advanced LF was 4.71 ± 0.53 born alive vs 9.55 ± 0.47 born from mating with healthy males, p  reproductive system.

  14. Sutureless anastomoses using magnetic rings in canine liver transplantation model.

    Science.gov (United States)

    Liu, Shi-Qi; Lei, Peng; Cui, Xiao-Hai; Lv, Yi; Li, Jian-Hui; Song, Yu-Long; Zhao, Ge

    2013-12-01

    In the first posttransplant month, the most frequent complications are due to technical problems related to complex vascular and bile duct reconstructions during the operation. Moreover, despite great improvements in suturing technique and materials, severe organ ischemia-reperfusion caused by time-consuming hand suturing is still an important factor in graft survival. During the operation, severe hypotension, hypoxic acidosis, hyperkalemia, and renal dysfunction may occur during the anhepatic phase due to the prolonged venous clamping time required for hand suturing. Therefore, hand suturing is a handicap in the development of further advancements in liver transplantation. In this study, we aimed to test a new "mechanical installation method" for rapid vascular reconstruction. The magnetic pinning-ring device was developed consisting of paired magnetic rings coated with titanium oxide and embedded in a polypropylene shell. The rings were equipped with alternately spaced holes and titanium pins. Forty adult mongrel dogs were randomly divided into groups: A (n = 16), all vascular and bile duct reconstruction by magnetic ring without venous bypass; B (n = 16), all vascular and bile duct reconstruction by hand suturing with venous bypass; C (n = 8), sham transplantation group, transection of all vessels and common bile duct followed by anastomosis with the magnetic rings without liver transplantation. From groups A and B, dogs were randomly selected as donors (n = 8) or recipients (n = 8) of liver transplantations. We recorded operation time, vascular and bile duct anastomosis time, anhepatic time, administration of supplemental fluids during operation, and survival; blood samples were collected for the detection of liver damage (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) and tumor necrosis factor α level. Patency was confirmed using ultrasound scans at various time points as late as 24 wk after surgery. Angiography was used to evaluate the

  15. Kidney function and mortality post-liver transplant in the Model for End-Stage Liver Disease era

    Directory of Open Access Journals (Sweden)

    Sethi A

    2011-11-01

    Full Text Available Aastha Sethi1, Michelle M Estrella1, Richard Ugarte2, Mohamed G Atta1 1Johns Hopkins University School of Medicine, Department of Medicine, Baltimore, MD, USA; 2University of Maryland Medical Center, Department of Medicine, Baltimore, MD, USA Abstract: The Model for End-Stage Liver Disease (MELD score incorporates serum creatinine and was introduced to facilitate allocation of orthotopic liver transplantation (LT. The objective is to determine the impact of MELD and kidney function on all-cause mortality. Among LTs performed in a tertiary referral hospital between 1995 and 2009, 419 cases were studied. Cox proportional hazards models were constructed to estimate the hazard ratios (HR and 95% confidence intervals (CI for death. Over mean follow-ups of 8.4 and 3.1 years during the pre-MELD and MELD era, 57 and 63 deaths were observed, respectively. Those transplanted during the MELD era had a higher likelihood of hepatorenal syndrome (8% vs 2%, P < 0.01, lower kidney function (median estimated glomerular filtration rate [eGFR] 77.8 vs 92.6 mL/min/1.73 m2, P < 0.01, and more pretransplantation renal replacement therapy (RRT (5% vs 1%; P < 0.01. All-cause mortality risk was similar in the MELD vs the pre-MELD era (HR: 0.98, 95% CI: 0.58–1.65. The risk of death, however, was nearly 3-fold greater (95% CI: 1.14–6.60 among those requiring pre-transplant RRT. Similarly, eGFR < 60 mL/min/1.73 m2 post-transplant was associated with a 2.5-fold higher mortality (95% CI: 1.48–4.11. The study suggests that MELD implementation had no impact on all-cause mortality post-LT. However, the need for pre-transplant RRT and post-transplant kidney dysfunction was associated with a more than 2-fold greater risk of subsequent death. Keywords: eGFR, mortality, MELD, liver transplant

  16. Adeno-associated viral vector serotype 5 poorly transduces liver in rat models.

    Directory of Open Access Journals (Sweden)

    Paula S Montenegro-Miranda

    Full Text Available Preclinical studies in mice and non-human primates showed that AAV serotype 5 provides efficient liver transduction and as such seems a promising vector for liver directed gene therapy. An advantage of AAV5 compared to serotype 8 already shown to provide efficient correction in a phase 1 trial in patients suffering from hemophilia B, is its lower seroprevalence in the general population. Our goal is liver directed gene therapy for Crigler-Najjar syndrome type I, inherited severe unconjugated hyperbilirubinemia caused by UGT1A1 deficiency. In a relevant animal model, the Gunn rat, we compared the efficacy of AAV 5 and 8 to that of AAV1 previously shown to be effective. Ferrying a construct driving hepatocyte specific expression of UGT1A1, both AAV8 and AAV1 provided an efficient correction of hyperbilirubinemia. In contrast to these two and to other animal models AAV5 failed to provide any correction. To clarify whether this unexpected finding was due to the rat model used or due to a problem with AAV5, the efficacy of this serotype was compared in a mouse and two additional rat strains. Administration of an AAV5 vector expressing luciferase under the control of a liver specific promoter confirmed that this serotype poorly performed in rat liver, rendering it not suitable for proof of concept studies in this species.

  17. Assessment of the diagnostic value of dual-energy CT and MRI in the detection of iatrogenically induced injuries of anterior cruciate ligament in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Fickert, S.; Niks, M.; Lehmann, L. [University Medical Center Mannheim, Center of Orthopaedics and Traumatology, Mannheim (Germany); Dinter, D.J.; Hammer, M.; Weckbach, S.; Schoenberg, S.O.; Jochum, S. [University Medical Center Mannheim, Department of Clinical Radiology and Nuclear Medicine, Mannheim (Germany)

    2013-03-15

    Magnetic resonance imaging (MRI) is the standard of reference for the non-invasive evaluation of ligament injuries of the knee. The development of dual-energy CT (DE-CT) made it possible to differentiate between tissues of different density by two simultaneous CT measurements with different tube voltages. This approach enables DE-CT to discriminate ligament structures without intra-articular contrast media injection. The aims of this study were on the one hand to determine the delineation of the anterior cruciate ligament (ACL) and on the other hand to assess the diagnostic value of DE-CT and MRI in the detection of iatrogenically induced injury of the ACL in a porcine knee joint model. Twenty porcine hind legs, which were placed in a preformed cast in order to achieve a standardized position, were scanned using DE-CT. Thereafter, a 1.5-T MRI using a standard protocol was performed. The imaging procedures were repeated with the same parameters after inducing defined lesions (total or partial incision) on the ACL arthroscopically. After post-processing, two radiologists and two orthopedic surgeons first analyzed the delineation of the ACL and then, using a consensus approach, the iatrogenically induced lesions. The result of the arthrotomy was defined as the standard of reference. The ACL could be visualized both on DE-CT and MRI in 100% of the cases. As for the MRI, the sensitivity and specificity of detecting the cruciate ligament lesion respectively compared with the defined arthrotomy was 66.7% and 78.6% for intact cruciate ligaments, 100% and 75% in the case of a complete lesion, 33.3% and 78.6% for lesions of the anteromedial bundle, and 0% and 100% for lesions of the posterolateral bundle. In comparison, DE-CT demonstrated a sensitivity and specificity of 66.7% and 71.4% in the case of intact cruciate ligaments, 75% and 68.8% in the case of completely discontinued ACLs, 0% and 92.9% in the case of lesions of the anteromedial bundle, and 25% and 87.5% in the

  18. Functional genomics unique to week 20 post wounding in the deep cone/fat dome of the Duroc/Yorkshire porcine model of fibroproliferative scarring.

    Science.gov (United States)

    Engrav, Loren H; Tuggle, Christopher K; Kerr, Kathleen F; Zhu, Kathy Q; Numhom, Surawej; Couture, Oliver P; Beyer, Richard P; Hocking, Anne M; Carrougher, Gretchen J; Ramos, Maria Luiza C; Klein, Matthew B; Gibran, Nicole S

    2011-04-20

    Hypertrophic scar was first described over 100 years ago; PubMed has more than 1,000 references on the topic. Nevertheless prevention and treatment remains poor, because 1) there has been no validated animal model; 2) human scar tissue, which is impossible to obtain in a controlled manner, has been the only source for study; 3) tissues typically have been homogenized, mixing cell populations; and 4) gene-by-gene studies are incomplete. We have assembled a system that overcomes these barriers and permits the study of genome-wide gene expression in microanatomical locations, in shallow and deep partial-thickness wounds, and pigmented and non-pigmented skin, using the Duroc(pigmented fibroproliferative)/Yorkshire(non-pigmented non-fibroproliferative) porcine model. We used this system to obtain the differential transcriptome at 1, 2, 3, 12 and 20 weeks post wounding. It is not clear when fibroproliferation begins, but it is fully developed in humans and the Duroc breed at 20 weeks. Therefore we obtained the derivative functional genomics unique to 20 weeks post wounding. We also obtained long-term, forty-six week follow-up with the model. 1) The scars are still thick at forty-six weeks post wounding further validating the model. 2) The differential transcriptome provides new insights into the fibroproliferative process as several genes thought fundamental to fibroproliferation are absent and others differentially expressed are newly implicated. 3) The findings in the derivative functional genomics support old concepts, which further validates the model, and suggests new avenues for reductionist exploration. In the future, these findings will be searched for directed networks likely involved in cutaneous fibroproliferation. These clues may lead to a better understanding of the systems biology of cutaneous fibroproliferation, and ultimately prevention and treatment of hypertrophic scarring.

  19. Functional genomics unique to week 20 post wounding in the deep cone/fat dome of the Duroc/Yorkshire porcine model of fibroproliferative scarring.

    Directory of Open Access Journals (Sweden)

    Loren H Engrav

    Full Text Available BACKGROUND: Hypertrophic scar was first described over 100 years ago; PubMed has more than 1,000 references on the topic. Nevertheless prevention and treatment remains poor, because 1 there has been no validated animal model; 2 human scar tissue, which is impossible to obtain in a controlled manner, has been the only source for study; 3 tissues typically have been homogenized, mixing cell populations; and 4 gene-by-gene studies are incomplete. METHODOLOGY/PRINCIPAL FINDINGS: We have assembled a system that overcomes these barriers and permits the study of genome-wide gene expression in microanatomical locations, in shallow and deep partial-thickness wounds, and pigmented and non-pigmented skin, using the Duroc(pigmented fibroproliferative/Yorkshire(non-pigmented non-fibroproliferative porcine model. We used this system to obtain the differential transcriptome at 1, 2, 3, 12 and 20 weeks post wounding. It is not clear when fibroproliferation begins, but it is fully developed in humans and the Duroc breed at 20 weeks. Therefore we obtained the derivative functional genomics unique to 20 weeks post wounding. We also obtained long-term, forty-six week follow-up with the model. CONCLUSIONS/SIGNIFICANCE: 1 The scars are still thick at forty-six weeks post wounding further validating the model. 2 The differential transcriptome provides new insights into the fibroproliferative process as several genes thought fundamental to fibroproliferation are absent and others differentially expressed are newly implicated. 3 The findings in the derivative functional genomics support old concepts, which further validates the model, and suggests new avenues for reductionist exploration. In the future, these findings will be searched for directed networks likely involved in cutaneous fibroproliferation. These clues may lead to a better understanding of the systems biology of cutaneous fibroproliferation, and ultimately prevention and treatment of hypertrophic scarring.

  20. Validation of 99mTechnetium-labeled mebrofenin hepatic extraction method to quantify meal-induced splanchnic blood flow responses using a porcine model

    DEFF Research Database (Denmark)

    Zacho, Helle Damgaard; Kristensen, Niels Bastian; Henriksen, Jens Henrik Sahl

    2012-01-01

    The aim of this study was to evaluate the measurement of the total splanchnic blood flow (SBF) using a clinical diagnostic method based on Fick's principle and hepatic extraction of 99mTc-mebrofenin (99mTc-MBF) compared with a paraaminohippuric acid (pAH) dilution method in a porcine model. Another...... aim was to investigate whether enterohepatic cycling of 99mTc-MBF affected the SBF measurement. Five indwelling catheters were placed in each pig (n = 15) in the portal, mesenteric, and hepatic veins, as well as in the aorta and the vena cava. The SBF was measured using both methods. The portal blood...... flow; the intestinal and hepatic oxygen uptake; the net fluxes of oxygen, lactate, and glucose; and the extraction fraction (EF) of 99mTc-MBF were measured before and for 70 min after feeding. The mean baseline SBF was 2,961 ml/min vs. 2,762 ml/min measured by pAH and 99mTc-MBF, respectively...

  1. Cyclic PaO2 oscillations assessed in the renal microcirculation: correlation with tidal volume in a porcine model of lung lavage.

    Science.gov (United States)

    Thomas, Rainer; Möllmann, Christian; Ziebart, Alexander; Liu, Tanghua; David, Matthias; Hartmann, Erik K

    2017-07-11

    Oscillations of the arterial partial pressure of oxygen induced by varying shunt fractions occur during cyclic alveolar recruitment within the injured lung. Recently, these were proposed as a pathomechanism that may be relevant for remote organ injury following acute respiratory distress syndrome. This study examines the transmission of oxygen oscillations to the renal tissue and their tidal volume dependency. Lung injury was induced by repetitive bronchoalveolar lavage in eight anaesthetized pigs. Cyclic alveolar recruitment was provoked by high tidal volume ventilation. Oscillations of the arterial partial pressure of oxygen were measured in real-time in the macrocirculation by multi-frequency phase fluorimetry and in the renal microcirculation by combined white-light spectrometry and laser-Doppler flowmetry during tidal volume down-titration. Significant respiratory-dependent oxygen oscillations were detected in the macrocirculation and transmitted to the renal microcirculation in a substantial extent. The amplitudes of these oscillations significantly correlate to the applied tidal volume and are minimized during down-titration. In a porcine model oscillations of the arterial partial pressure of oxygen are induced by cyclic alveolar recruitment and transmitted to the renal microcirculation in a tidal volume-dependent fashion. They might play a role in organ crosstalk and remote organ damage following lung injury.

  2. Host homeostatic responses to alcohol-induced cellular stress in animal models of alcoholic liver disease.

    Science.gov (United States)

    Wang, He Joe; Murray, Gary J; Jung, Mary Katherine

    2015-01-01

    Humans develop various clinical phenotypes of severe alcoholic liver disease, including alcoholic hepatitis and cirrhosis, generally after decades of heavy drinking. In such individuals, following each episode of drinking, their livers experience heightened intracellular and extracellular stresses that are closely associated with alcohol consumption and alcohol metabolism. This article focuses on the latest advances made in animal models on evolutionarily conserved homeostatic mechanisms for coping with and resolving these stress conditions. The mechanisms discussed include the stress-activated protein kinase JNK, energy regulator AMPK, autophagy and the inflammatory response. Over time, the host may respond variably to stress with protective mechanisms that are critical in determining an individual's vulnerability to developing severe alcoholic liver disease. A systematic review of these mechanisms and their temporal changes in animal models provides the basis for general conclusions, and raises questions for future studies. The relevance of these data to human conditions is also discussed.

  3. The Use of an Acellular Oxygen Carrier in a Human Liver Model of Normothermic Machine Perfusion.

    Science.gov (United States)

    Laing, Richard W; Bhogal, Ricky H; Wallace, Lorraine; Boteon, Yuri; Neil, Desley A H; Smith, Amanda; Stephenson, Barney T F; Schlegel, Andrea; Hübscher, Stefan G; Mirza, Darius F; Afford, Simon C; Mergental, Hynek

    2017-11-01

    Normothermic machine perfusion of the liver (NMP-L) is a novel technique that preserves liver grafts under near-physiological conditions while maintaining their normal metabolic activity. This process requires an adequate oxygen supply, typically delivered by packed red blood cells (RBC). We present the first experience using an acellular hemoglobin-based oxygen carrier (HBOC) Hemopure in a human model of NMP-L. Five discarded high-risk human livers were perfused with HBOC-based perfusion fluid and matched to 5 RBC-perfused livers. Perfusion parameters, oxygen extraction, metabolic activity, and histological features were compared during 6 hours of NMP-L. The cytotoxicity of Hemopure was also tested on human hepatic primary cell line cultures using an in vitro model of ischemia reperfusion injury. The vascular flow parameters and the perfusate lactate clearance were similar in both groups. The HBOC-perfused livers extracted more oxygen than those perfused with RBCs (O2 extraction ratio 13.75 vs 9.43 % ×10 per gram of tissue, P = 0.001). In vitro exposure to Hemopure did not alter intracellular levels of reactive oxygen species, and there was no increase in apoptosis or necrosis observed in any of the tested cell lines. Histological findings were comparable between groups. There was no evidence of histological damage caused by Hemopure. Hemopure can be used as an alternative oxygen carrier to packed red cells in NMP-L perfusion fluid.

  4. Assessment of non-invasive models for liver fibrosis in chronic hepatitis B virus related liver disease patients in resource limited settings.

    Science.gov (United States)

    Shrivastava, Rakesh; Sen, Sourav; Banerji, Debabrata; Praharaj, Ashok K; Chopra, Gurvinder Singh; Gill, Satyajit Singh

    2013-01-01

    A total of 350 million individuals are affected by chronic hepatitis B virus infection world-wide. Historically, liver biopsy has been instrumental in adequately assessing patients with chronic liver disease. A number of non-invasive models have been studied world-wide. The aim of this study is to assess the utility of non-invasive mathematical models of liver fibrosis in chronic hepatitis B (CHB). Indian patients in a resource limited setting using routinely performed non-invasive laboratory investigations. A cross-sectional study carried out at a tertiary care center. A total of 52 consecutive chronic liver disease patients who underwent percutaneous liver biopsy and 25 healthy controls were enrolled in the study. Routine laboratory investigations included serum aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Gama glutamyl transpeptidase (GGT), total bilirubin, total cholesterol, prothrombin time and platelet count. Three non-invasive models for namely aspartate aminotransferase to platelet ratio index (APRI), Fibrosis 4 (FIB-4) and Forn's index were calculated. Outcomes were compared for the assessment of best predictor of fibrosis by calculating the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of each index. Medcalc online software and by Microsoft Excel Worksheet. Chi-square test was used for significance. P value value of all 3 indices were significantly higher in patients group as compare with the controls (P model for excluding significant liver fibrosis while FIB-4 with a PPV of 61% showed fair correlation with significant fibrosis. Thus, these two non-invasive models for predicting of liver fibrosis, namely APRI and FIB-4, can be utilized in combination as screening tools in monitoring of CHB patients, especially in resource limiting settings.

  5. Validation and comparison of seventeen noninvasive models for evaluating liver fibrosis in Chinese hepatitis B patients.

    Science.gov (United States)

    Dong, Minhui; Wu, Jingwen; Yu, Xueping; Li, Jing; Yang, Sisi; Qi, Xun; Mao, Richeng; Zhang, Yongmei; Yu, Jie; Zhu, Haoxiang; Yang, Feifei; Qin, Yanli; Zhang, Jiming

    2018-01-03

    To avoid liver biopsy, many noninvasive models comprised of serum markers for liver fibrosis assessment have been developed. Given that most of them were developed in hepatitis C cohorts and few of them have been validated in Chinese hepatitis B patients, we aim to conduct this validation and compare their diagnostic accuracies in such a population. A total of 937 HBV-infected patients who underwent liver biopsy were included in this single-centre retrospective study. The diagnostic accuracies of the 17 noninvasive models were assessed by areas under the receiver-operating characteristic curves (AUROCs), using histologically evaluated fibrotic stages of the biopsy specimens as standards. To compare efficiencies of the models, a grading system based on AUROC levels was developed. For discriminating significant fibrosis in all patients, the best three noninvasive models were King's score (AUROC = 0.756), Virahep-C model (AUROC = 0.756) and GPR (AUROC = 0.744); and for diagnosing cirrhosis, Lok index (AUROC = 0.832), FI (AUROC = 0.820) and FIB-4 (AUROC = 0.818) got the first three places. AUROCs in HBeAg-positive group were generally higher than those in HBeAg-negative group. In addition, based on the grading system, Virahep-C and GPR outstood others in evaluating liver fibrosis in all patients. In Chinese HBV-infected patients, Virahep-C models and GPR had high accuracies in diagnosing liver fibrosis and cirrhosis, while the most discussed models like APRI and FIB-4 did not outstand. Assessment should take into account the HBeAg sero-status, since these noninvasive models were more appropriate for HBeAg-positive patients than HBeAg-negative ones. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Ultrasound imaging in an experimental model of fatty liver disease and cirrhosis in rats

    Directory of Open Access Journals (Sweden)

    Campos de Carvalho Antonio

    2010-01-01

    Full Text Available Abstract Background Domestic dogs and cats are very well known to develop chronic hepatic diseases, including hepatic lipidosis and cirrhosis. Ultrasonographic examination is extensively used to detect them. However, there are still few reports on the use of the ultrasound B-mode scan in correlation with histological findings to evaluate diffuse hepatic changes in rodents, which represent the most important animal group used in experimental models of liver diseases. The purpose of this study was to determine the reliability of ultrasound findings in the assessment of fatty liver disease and cirrhosis when compared to histological results in Wistar rats by following up a murine model of chronic hepatic disease. Results Forty Wistar rats (30 treated, 10 controls were included. Liver injury was induced by dual exposure to CCl4 and ethanol for 4, 8 and 15 weeks. Liver echogenicity, its correlation to the right renal cortex echogenicity, measurement of portal vein diameter (PVD and the presence of ascites were evaluated and compared to histological findings of hepatic steatosis and cirrhosis. Liver echogenicity correlated to hepatic steatosis when it was greater or equal to the right renal cortex echogenicity, with a sensitivity of 90%, specificity of 100%, positive and negative predictive values of 100% and 76.9% respectively, and accuracy of 92.5%. Findings of heterogeneous liver echogenicity and irregular surface correlated to liver cirrhosis with a sensitivity of 70.6%, specificity of 100%, positive and negative predictive values of 100% and 82.1% respectively, and accuracy of 87.5%. PVD was significantly increased in both steatotic and cirrhotic rats; however, the later had greater diameters. PVD cut-off point separating steatosis from cirrhosis was 2.1 mm (sensitivity of 100% and specificity of 90.5%. One third of cirrhotic rats presented with ascites. Conclusion The use of ultrasound imaging in the follow-up of murine diffuse liver disease

  7. Ultrasound imaging in an experimental model of fatty liver disease and cirrhosis in rats

    Science.gov (United States)

    2010-01-01

    Background Domestic dogs and cats are very well known to develop chronic hepatic diseases, including hepatic lipidosis and cirrhosis. Ultrasonographic examination is extensively used to detect them. However, there are still few reports on the use of the ultrasound B-mode scan in correlation with histological findings to evaluate diffuse hepatic changes in rodents, which represent the most important animal group used in experimental models of liver diseases. The purpose of this study was to determine the reliability of ultrasound findings in the assessment of fatty liver disease and cirrhosis when compared to histological results in Wistar rats by following up a murine model of chronic hepatic disease. Results Forty Wistar rats (30 treated, 10 controls) were included. Liver injury was induced by dual exposure to CCl4 and ethanol for 4, 8 and 15 weeks. Liver echogenicity, its correlation to the right renal cortex echogenicity, measurement of portal vein diameter (PVD) and the presence of ascites were evaluated and compared to histological findings of hepatic steatosis and cirrhosis. Liver echogenicity correlated to hepatic steatosis when it was greater or equal to the right renal cortex echogenicity, with a sensitivity of 90%, specificity of 100%, positive and negative predictive values of 100% and 76.9% respectively, and accuracy of 92.5%. Findings of heterogeneous liver echogenicity and irregular surface correlated to liver cirrhosis with a sensitivity of 70.6%, specificity of 100%, positive and negative predictive values of 100% and 82.1% respectively, and accuracy of 87.5%. PVD was significantly increased in both steatotic and cirrhotic rats; however, the later had greater diameters. PVD cut-off point separating steatosis from cirrhosis was 2.1 mm (sensitivity of 100% and specificity of 90.5%). One third of cirrhotic rats presented with ascites. Conclusion The use of ultrasound imaging in the follow-up of murine diffuse liver disease models is feasible and

  8. Significantly improved survival time in pigs with complete liver ischemia treated with a novel bioartificial liver

    NARCIS (Netherlands)

    Flendrig, L. M.; Calise, F.; Di Florio, E.; Mancini, A.; Ceriello, A.; Santaniello, W.; Mezza, E.; Sicoli, F.; Belleza, G.; Bracco, A.; Cozzolino, S.; Scala, D.; Mazzone, M.; Fattore, M.; Gonzales, E.; Chamuleau, R. A.

    1999-01-01

    Aim of the study was to evaluate treatment efficacy and safety of a scaled-up version of our porcine hepatocytes based BAL system in pigs with complete liver ischemia (LIS). Thirty-one pigs underwent total devascularization of the liver (LIS) by termino-lateral porta-caval shunts and sutures around

  9. HEPATOKIN1 is a biochemistry-based model of liver metabolism for applications in medicine and pharmacology.

    Science.gov (United States)

    Berndt, Nikolaus; Bulik, Sascha; Wallach, Iwona; Wünsch, Tilo; König, Matthias; Stockmann, Martin; Meierhofer, David; Holzhütter, Hermann-Georg

    2018-06-19

    The epidemic increase of non-alcoholic fatty liver diseases (NAFLD) requires a deeper understanding of the regulatory circuits controlling the response of liver metabolism to nutritional challenges, medical drugs, and genetic enzyme variants. As in vivo studies of human liver metabolism are encumbered with serious ethical and technical issues, we developed a comprehensive biochemistry-based kinetic model of the central liver metabolism including the regulation of enzyme activities by their reactants, allosteric effectors, and hormone-dependent phosphorylation. The utility of the model for basic research and applications in medicine and pharmacology is illustrated by simulating diurnal variations of the metabolic state of the liver at various perturbations caused by nutritional challenges (alcohol), drugs (valproate), and inherited enzyme disorders (galactosemia). Using proteomics data to scale maximal enzyme activities, the model is used to highlight differences in the metabolic functions of normal hepatocytes and malignant liver cells (adenoma and hepatocellular carcinoma).

  10. Modeling the spatio-temporal dynamics of porcine reproductive & respiratory syndrome cases at farm level using geographical distance and pig trade network matrices.

    Science.gov (United States)

    Amirpour Haredasht, Sara; Polson, Dale; Main, Rodger; Lee, Kyuyoung; Holtkamp, Derald; Martínez-López, Beatriz

    2017-06-07

    Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating infectious diseases for the swine industry. A better understanding of the disease dynamics and the transmission pathways under diverse epidemiological scenarios is a key for the successful PRRS control and elimination in endemic settings. In this paper we used a two step parameter-driven (PD) Bayesian approach to model the spatio-temporal dynamics of PRRS and predict the PRRS status on farm in subsequent time periods in an endemic setting in the US. For such purpose we used information from a production system with 124 pig sites that reported 237 PRRS cases from 2012 to 2015 and from which the pig trade network and geographical location of farms (i.e., distance was used as a proxy of airborne transmission) was available. We estimated five PD models with different weights namely: (i) geographical distance weight which contains the inverse distance between each pair of farms in kilometers, (ii) pig trade weight (PT ji ) which contains the absolute number of pig movements between each pair of farms, (iii) the product between the distance weight and the standardized relative pig trade weight, (iv) the product between the standardized distance weight and the standardized relative pig trade weight, and (v) the product of the distance weight and the pig trade weight. The model that included the pig trade weight matrix provided the best fit to model the dynamics of PRRS cases on a 6-month basis from 2012 to 2015 and was able to predict PRRS outbreaks in the subsequent time period with an area under the ROC curve (AUC) of 0.88 and the accuracy of 85% (105/124). The result of this study reinforces the importance of pig trade in PRRS transmission in the US. Methods and results of this study may be easily adapted to any production system to characterize the PRRS dynamics under diverse epidemic settings to more timely support decision-making.

  11. Estimating Parameters Related to the Lifespan of Passively Transferred and Vaccine-Induced Porcine Reproductive and Respiratory Syndrome Virus Type I Antibodies by Modeling Field Data

    Directory of Open Access Journals (Sweden)

    Mathieu Andraud

    2018-01-01

    Full Text Available The outputs of epidemiological models are strongly related to the structure of the model and input parameters. The latter are defined by fitting theoretical concepts to actual data derived from field or experimental studies. However, some parameters may remain difficult to estimate and are subject to uncertainty or sensitivity analyses to determine their variation range and their global impact on model outcomes. As such, the evaluation of immunity duration is often a puzzling issue requiring long-term follow-up data that are, most of time, not available. The present analysis aims at characterizing the kinetics of antibodies against Porcine Reproductive and Respiratory Syndrome virus (PRRSv from longitudinal data sets. The first data set consisted in the serological follow-up of 22 vaccinated gilts during 21 weeks post-vaccination (PV. The second one gathered the maternally derived antibodies (MDAs kinetics in piglets from three different farms up to 14 weeks of age. The peak of the PV serological response against PRRSv was reached 6.9 weeks PV on average with an average duration of antibodies persistence of 26.5 weeks. In the monitored cohort of piglets, the duration of passive immunity was found relatively short, with an average duration of 4.8 weeks. The level of PRRSv-MDAs was found correlated with the dams’ antibody titer at birth, and the antibody persistence was strongly related to the initial MDAs titers in piglets. These results evidenced the importance of PRRSv vaccination schedule in sows, to optimize the delivery of antibodies to suckling piglets. These estimates of the duration of active and passive immunity could be further used as input parameters of epidemiological models to analyze their impact on the persistence of PRRSv within farms.

  12. Diet-induced metabolic hamster model of nonalcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    Bhathena J

    2011-06-01

    Full Text Available Jasmine Bhathena, Arun Kulamarva, Christopher Martoni, Aleksandra Malgorzata Urbanska, Meenakshi Malhotra, Arghya Paul, Satya PrakashBiomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering, Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, Montreal, Québec, CanadaBackground: Obesity, hypercholesterolemia, elevated triglycerides, and type 2 diabetes are major risk factors for metabolic syndrome. Hamsters, unlike rats or mice, respond well to diet-induced obesity, increase body mass and adiposity on group housing, and increase food intake due to social confrontation-induced stress. They have a cardiovascular and hepatic system similar to that of humans, and can thus be a useful model for human pathophysiology.Methods: Experiments were planned to develop a diet-induced Bio F1B Golden Syrian hamster model of dyslipidemia and associated nonalcoholic fatty liver disease in the metabolic syndrome. Hamsters were fed a normal control diet, a high-fat/high-cholesterol diet, a high-fat/high-cholesterol/methionine-deficient/choline-devoid diet, and a high-fat/high-cholesterol/choline-deficient diet. Serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, atherogenic index, and body weight were quantified biweekly. Fat deposition in the liver was observed and assessed following lipid staining with hematoxylin and eosin and with oil red O.Results: In this study, we established a diet-induced Bio F1B Golden Syrian hamster model for studying dyslipidemia and associated nonalcoholic fatty liver disease in the metabolic syndrome. Hyperlipidemia and elevated serum glucose concentrations were induced using this diet. Atherogenic index was elevated, increasing the risk for a cardiovascular event. Histological analysis of liver specimens at the end of four weeks showed increased fat deposition in the liver of animals fed

  13. Mouse Precision-Cut Liver Slices as an ex Vivo Model To Study Idiosyncratic Drug-Induced Liver Injury

    NARCIS (Netherlands)

    Hadi, Mackenzie; Chen, Yixi; Starokozhko, Viktoriia; Groothuis, Geny M. M.; Merema, M.T.

    Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in

  14. Kinetic Modelling of Infection Tracers [18F]FDG, [68Ga]Ga-Citrate, [11C]Methionine, and [11C]Donepezil in a Porcine Osteomyelitis Model

    DEFF Research Database (Denmark)

    Jødal, Lars; Jensen, Svend Borup; Nielsen, Ole Lerberg

    2017-01-01

    Introduction. Positron emission tomography (PET) is increasingly applied for infection imaging using [18F]FDG as tracer, but uptake is unspecific. The present study compares the kinetics of [18F]FDG and three other PET tracers with relevance for infection imaging. Methods. A juvenile porcine...... osteomyelitis model was used. Eleven pigs underwent PET/CT with 60-minute dynamic PET imaging of [18F]FDG, [68Ga]Ga-citrate, [11C]methionine, and/or [11C]donepezil, along with blood sampling. For infectious lesions, kinetic modelling with one- and two-tissue-compartment models was conducted for each tracer...... for the analysis. Conclusions. The kinetics of the four studied tracers in infection was characterized. For clinical applications, [18F]FDG remains the first-choice PET tracer. [11C]methionine may have a potential for detecting soft tissue infections. [68Ga]Ga-citrate and [11C]donepezil were not found useful...

  15. A cellular model to study drug-induced liver injury in nonalcoholic fatty liver disease: Application to acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Michaut, Anaïs; Le Guillou, Dounia [INSERM, U991, Université de Rennes 1, Rennes (France); Moreau, Caroline [INSERM, U991, Université de Rennes 1, Rennes (France); Service de Biochimie et Toxicologie, CHU Pontchaillou, Rennes (France); Bucher, Simon [INSERM, U991, Université de Rennes 1, Rennes (France); McGill, Mitchell R. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Martinais, Sophie [INSERM, U991, Université de Rennes 1, Rennes (France); Gicquel, Thomas; Morel, Isabelle [INSERM, U991, Université de Rennes 1, Rennes (France); Service de Biochimie et Toxicologie, CHU Pontchaillou, Rennes (France); Robin, Marie-Anne [INSERM, U991, Université de Rennes 1, Rennes (France); Jaeschke, Hartmut [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Fromenty, Bernard, E-mail: bernard.fromenty@inserm.fr [INSERM, U991, Université de Rennes 1, Rennes (France)

    2016-02-01

    Obesity and nonalcoholic fatty liver disease (NAFLD) can increase susceptibility to hepatotoxicity induced by some xenobiotics including drugs, but the involved mechanisms are poorly understood. For acetaminophen (APAP), a role of hepatic cytochrome P450 2E1 (CYP2E1) is suspected since the activity of this enzyme is consistently enhanced during NAFLD. The first aim of our study was to set up a cellular model of NAFLD characterized not only by triglyceride accumulation but also by higher CYP2E1 activity. To this end, human HepaRG cells were incubated for one week with stearic acid or oleic acid, in the presence of different concentrations of insulin. Although cellular triglycerides and the expression of lipid-responsive genes were similar with both fatty acids, CYP2E1 activity was significantly increased only by stearic acid. CYP2E1 activity was reduced by insulin and this effect was reproduced in cultured primary human hepatocytes. Next, APAP cytotoxicity was assessed in HepaRG cells with or without lipid accretion and CYP2E1 induction. Experiments with a large range of APAP concentrations showed that the loss of ATP and glutathione was almost always greater in the presence of stearic acid. In cells pretreated with the CYP2E1 inhibitor chlormethiazole, recovery of ATP was significantly higher in the presence of stearate with low (2.5 mM) or high (20 mM) concentrations of APAP. Levels of APAP-glucuronide were significantly enhanced by insulin. Hence, HepaRG cells can be used as a valuable model of NAFLD to unveil important metabolic and hormonal factors which can increase susceptibility to drug-induced hepatotoxicity. - Highlights: • Nonalcoholic fatty liver disease (NAFLD) is frequent in obese individuals. • NAFLD can favor hepatotoxicity induced by some drugs including acetaminophen (APAP). • A model of NAFLD was set up by using HepaRG cells incubated with stearate or oleate. • Stearate-loaded HepaRG cells presented higher cytochrome P450 2E1 (CYP2E1

  16. A model of hydraulic interactions in liver parenchyma as forces behind the intrahepatic bile flow.

    Science.gov (United States)

    Kurbel, S; Kurbel, B; Dmitrovic, B; Wagner, J

    2001-05-01

    The small diameters of bile canaliculi and interlobular bile ducts make it hard to attribute the bile flow solely to the process of secretion. In the model liver within its capsule is considered a limited space in which volume expansions of one part are possible only through the shrinking of other parts. The liver capsule allows only very slow volume changes. The rate of blood flow through the sinusoides is governed by the Poisseuill-Hagen law. The model is based on a concept of circulatory liver units. A unit would contain a group of acini sharing the same conditions of arterial flow. We can imagine them as an acinar group behind the last pressure reducer on one arterial branch. Acini from neighboring units compose liver lobules and drain through the same central venule. One lobule can contain acini from several neighboring circulatory units. The perfusion cycle in one unit begins with a transient tide in the arterial flow, governed by local mediators. Corresponding acini expand, grabbing the space by compressing their neighbors in the same lobules. Vascular resistance is reduced in dilated and increased in compressed acini. Portal blood flows through the dilated acini, bypassing the compressed neighbors. The cycle ends when the portal tide slowly diminishes and acinar volume is back on the interphase value until the new perfusion cycle is started in another circulatory unit. Each cycle probably takes minutes to complete. Increased pressures both in dilated and in compressed acini force the bile to move from acinar canalicules. Both up and down changes in acinar volume might force the acinar biliary flow. In cases of arterial vasoconstriction, increased activity of vasoactive substances would keep most of the circulatory units in the interphase and increased liver resistance can be expected. Liver fibrosis makes all acini to be of fixed volume and result in increased resistance. Because of that, low pressure portal flow would be more compromised, as reported. In

  17. Sorafenib prevents liver fibrosis in a non-alcoholic steatohepatitis (NASH) rodent model

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, J.T.; Pereira, I.V.A.; Torres, M.M.; Bida, P.M. [Disciplina de Gastroenterologia Clínica (LIM-07), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Coelho, A.M.M. [Disciplina de Transplante de Órgãos do Aparelho Digestivo (LIM-37), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Xerfan, M.P. [Disciplina de Gastroenterologia Clínica (LIM-07), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Cogliati, B. [Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP (Brazil); Barbeiro, D.F. [Disciplina de Emergências Clínicas (LIM-51), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Mazo, D.F.C. [Disciplina de Gastroenterologia Clínica (LIM-07), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Kubrusly, M.S.; D' Albuquerque, L.A.C. [Disciplina de Transplante de Órgãos do Aparelho Digestivo (LIM-37), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Souza, H.P. [Disciplina de Emergências Clínicas (LIM-51), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Carrilho, F.J.; Oliveira, C.P. [Disciplina de Gastroenterologia Clínica (LIM-07), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-02-24

    Liver fibrosis occurring as an outcome of non-alcoholic steatohepatitis (NASH) can precede the development of cirrhosis. We investigated the effects of sorafenib in preventing liver fibrosis in a rodent model of NASH. Adult Sprague-Dawley rats were fed a choline-deficient high-fat diet and exposed to diethylnitrosamine for 6 weeks. The NASH group (n=10) received vehicle and the sorafenib group (n=10) received 2.5 mg·kg{sup -1}·day{sup -1} by gavage. A control group (n=4) received only standard diet and vehicle. Following treatment, animals were sacrificed and liver tissue was collected for histologic examination, mRNA isolation, and analysis of mitochondrial function. Genes related to fibrosis (MMP9, TIMP1, TIMP2), oxidative stress (HSP60, HSP90, GST), and mitochondrial biogenesis (PGC1α) were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Liver mitochondrial oxidation activity was measured by a polarographic method, and cytokines by enzyme-linked immunosorbent assay (ELISA). Sorafenib treatment restored mitochondrial function and reduced collagen deposition by nearly 63% compared to the NASH group. Sorafenib upregulated PGC1α and MMP9 and reduced TIMP1 and TIMP2 mRNA and IL-6 and IL-10 protein expression. There were no differences in HSP60, HSP90 and GST expression. Sorafenib modulated PGC1α expression, improved mitochondrial respiration and prevented collagen deposition. It may, therefore, be useful in the treatment of liver fibrosis in NASH.

  18. Novel porcine repetitive elements

    Directory of Open Access Journals (Sweden)

    Nonneman Dan J

    2006-12-01

    Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

  19. Quantification of physiological levels of vitamin D3 and 25-hydroxyvitamin D3 in porcine fat and liver in subgram sample sizes

    DEFF Research Database (Denmark)

    Burild, Anders; Frandsen, Henrik Lauritz; Poulsen, Morten

    2014-01-01

    Most methods for the quantification of physiological levels of vitamin D3 and 25‐hydroxyvitamin D3 are developed for food analysis where the sample size is not usually a critical parameter. In contrast, in life science studies sample sizes are often limited. A very sensitive liquid chromatography...... with tandem mass spectrometry method was developed to quantify vitamin D3 and 25‐hydroxyvitamin D3 simultaneously in porcine tissues. A sample of 0.2–1 g was saponified followed by liquid–liquid extraction and normal‐phase solid‐phase extraction. The analytes were derivatized with 4‐phenyl‐1,2,4‐triazoline‐3...

  20. Liver transplant

    Science.gov (United States)

    Hepatic transplant; Transplant - liver; Orthotopic liver transplant; Liver failure - liver transplant; Cirrhosis - liver transplant ... The donated liver may be from: A donor who has recently died and has not had liver injury. This type of ...

  1. Precision-cut liver slices as a model for the early onset of liver fibrosis to test antifibrotic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Westra, Inge M. [Division of Pharmacokinetics, Toxicology and Targeting, Department of Pharmacy, University of Groningen (Netherlands); Oosterhuis, Dorenda [Division of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, University of Groningen (Netherlands); Groothuis, Geny M.M. [Division of Pharmacokinetics, Toxicology and Targeting, Department of Pharmacy, University of Groningen (Netherlands); Olinga, Peter, E-mail: p.olinga@rug.nl [Division of Pharmaceutical Technology and Biopharmacy, Department of Pharmacy, University of Groningen (Netherlands)

    2014-01-15

    Induction of fibrosis during prolonged culture of precision-cut liver slices (PCLS) was reported. In this study, the use of rat PCLS was investigated to further characterize the mechanism of early onset of fibrosis in this model and the effects of antifibrotic compounds. Rat PCLS were incubated for 48 h, viability was assessed by ATP and gene expression of PDGF-B and TGF-β1 and the fibrosis markers Hsp47, αSma and Pcol1A1 and collagen1 protein expressions were determined. The effects of the antifibrotic drugs imatinib, sorafenib and sunitinib, PDGF-pathway inhibitors, and perindopril, valproic acid, rosmarinic acid, tetrandrine and pirfenidone, TGFβ-pathway inhibitors, were determined. After 48 h of incubation, viability of the PCLS was maintained and gene expression of PDGF-B was increased while TGF-β1 was not changed. Hsp47, αSma and Pcol1A1 gene expressions were significantly elevated in PCLS after 48 h, which was further increased by PDGF-BB and TGF-β1. The increased gene expression of fibrosis markers was inhibited by all three PDGF-inhibitors, while TGFβ-inhibitors showed marginal effects. The protein expression of collagen 1 was inhibited by imatinib, perindopril, tetrandrine and pirfenidone. In conclusion, the increased gene expression of PDGF-B and the down-regulation of fibrosis markers by PDGF-pathway inhibitors, together with the absence of elevated TGF-β1 gene expression and the limited effect of the TGFβ-pathway inhibitors, indicated the predominance of the PDGF pathway in the early onset of fibrosis in PCLS. PCLS appear a useful model for research of the early onset of fibrosis and for testing of antifibrotic drugs acting on the PDGF pathway. - Highlights: • During culture, fibrosis markers increased in precision-cut liver slices (PCLS). • Gene expression of PDGF-β was increased, while TGFβ was not changed in rat PCLS. • PDGF-pathway inhibitors down-regulated this increase of fibrosis markers. • TGFβ-pathway inhibitors had only

  2. Dynamic PET of human liver inflammation: impact of kinetic modeling with optimization-derived dual-blood input function.

    Science.gov (United States)

    Wang, Guobao; Corwin, Michael T; Olson, Kristin A; Badawi, Ramsey D; Sarkar, Souvik

    2018-05-30

    The hallmark of nonalcoholic steatohepatitis is hepatocellular inflammation and injury in the setting of hepatic steatosis. Recent work has indicated that dynamic 18F-FDG PET with kinetic modeling has the potential to assess hepatic inflammation noninvasively, while static FDG-PET did not show a promise. Because the liver has dual blood supplies, kinetic modeling of dynamic liver PET data is challenging in human studies. The objective of this study is to evaluate and identify a dual-input kinetic modeling approach for dynamic FDG-PET of human liver inflammation. Fourteen human patients with nonalcoholic fatty liver disease were included in the study. Each patient underwent one-hour dynamic FDG-PET/CT scan and had liver biopsy within six weeks. Three models were tested for kinetic analysis: traditional two-tissue compartmental model with an image-derived single-blood input function (SBIF), model with population-based dual-blood input function (DBIF), and modified model with optimization-derived DBIF through a joint estimation framework. The three models were compared using Akaike information criterion (AIC), F test and histopathologic inflammation reference. The results showed that the optimization-derived DBIF model improved the fitting of liver time activity curves and achieved lower AIC values and higher F values than the SBIF and population-based DBIF models in all patients. The optimization-derived model significantly increased FDG K1 estimates by 101% and 27% as compared with traditional SBIF and population-based DBIF. K1 by the optimization-derived model was significantly associated with histopathologic grades of liver inflammation while the other two models did not provide a statistical significance. In conclusion, modeling of DBIF is critical for kinetic analysis of dynamic liver FDG-PET data in human studies. The optimization-derived DBIF model is more appropriate than SBIF and population-based DBIF for dynamic FDG-PET of liver inflammation. © 2018

  3. Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems.

    Science.gov (United States)

    Harari, Colin M; Magagna, Michelle; Bedoya, Mariajose; Lee, Fred T; Lubner, Meghan G; Hinshaw, J Louis; Ziemlewicz, Timothy; Brace, Christopher L

    2016-01-01

    To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue. All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type. On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery. © RSNA, 2015.

  4. Experimental liver fibrosis research: update on animal models, legal issues and translational aspects

    Science.gov (United States)

    2013-01-01

    Liver fibrosis is defined as excessive extracellular matrix deposition and is based on complex interactions between matrix-producing hepatic stellate cells and an abundance of liver-resident and infiltrating cells. Investigation of these processes requires in vitro and in vivo experimental work in animals. However, the use of animals in translational research will be increasingly challenged, at least in countries of the European Union, because of the adoption of new animal welfare rules in 2013. These rules will create an urgent need for optimized standard operating procedures regarding animal experimentation and improved international communication in the liver fibrosis community. This review gives an update on current animal models, techniques and underlying pathomechanisms with the aim of fostering a critical discussion of the limitations and potential of up-to-date animal experimentation. We discuss potential complications in experimental liver fibrosis and provide examples of how the findings of studies in which these models are used can be translated to human disease and therapy. In this review, we want to motivate the international community to design more standardized animal models which might help to address the legally requested replacement, refinement and reduction of animals in fibrosis research. PMID:24274743

  5. Evaluation of a fully absorbable poly-4-hydroxybutyrate/absorbable barrier composite mesh in a porcine model of ventral hernia repair.

    Science.gov (United States)

    Scott, Jeffrey R; Deeken, Corey R; Martindale, Robert G; Rosen, Michael J

    2016-09-01

    The objective of this study was to evaluate the mechanical and histological properties of a fully absorbable poly-4-hydroxybutyrate/absorbable barrier composite mesh (Phasix™ ST) compared to partially absorbable (Ventralight™ ST), fully absorbable (Phasix™), and biologically derived (Strattice™) meshes in a porcine model of ventral hernia repair. Bilateral abdominal surgical defects were created in twenty-four Yucatan pigs, repaired with intraperitoneal (Phasix™ ST, Ventralight™ ST) or retromuscular (Phasix™, Strattice™) mesh, and evaluated at 12 and 24 weeks (n = 6 mesh/group/time point). Prior to implantation, Strattice™ demonstrated significantly higher (p weeks, mesh/repair strength was significantly greater than NAW (p weeks (p > 0.05). Phasix™ mesh/repair strength was significantly greater than Strattice™ (p weeks, and Ventralight™ ST mesh/repair strength was significantly greater than Phasix™ ST mesh (p weeks. At 12 and 24 weeks, Phasix™ ST and Ventralight™ ST were associated with mild inflammation and minimal-mild fibrosis/neovascularization, with no significant differences between groups. At both time points, Phasix™ was associated with minimal-mild inflammation/fibrosis and mild neovascularization. Strattice™ was associated with minimal inflammation/fibrosis, with minimal neovascularization at 12 weeks, which increased to mild by 24 weeks. Strattice™ exhibited significantly less neovascularization than Phasix™ at 12 weeks and significantly greater inflammation at 24 weeks due to remodeling. Phasix™ ST demonstrated mechanical and histological properties comparable to partially absorbable (Ventralight™ ST) and fully resorbable (Phasix™) meshes at 12 and 24 weeks in this model. Data also suggest that fully absorbable meshes with longer-term resorption profiles may provide improved mechanical and histological properties compared to biologically derived scaffolds.

  6. Endoscopic ultrasound-guided biliary drainage using a newly designed metal stent with a thin delivery system: a preclinical study in phantom and porcine models.

    Science.gov (United States)

    Minaga, Kosuke; Kitano, Masayuki; Itonaga, Masahiro; Imai, Hajime; Miyata, Takeshi; Yamao, Kentaro; Tamura, Takashi; Nuta, Junya; Warigaya, Kenji; Kudo, Masatoshi

    2017-12-08

    This study was designed to evaluate the feasibility and safety of a newly designed self-expandable metal stent for endoscopic ultrasound-guided biliary drainage (EUS-BD) when it was delivered via three different stent delivery systems: a 7.5Fr delivery catheter with a bullet-shaped tip (7.5Fr-bullet), a 7Fr catheter with a bullet-shaped tip (7Fr-bullet), or a 7Fr catheter with a tee-shaped tip (7Fr-tee). This experimental study utilized a porcine model of biliary dilatation involving ten pigs. In the animal study, technical feasibility and clinical outcomes of the stent when placed with each of the delivery systems were examined. In addition, a phantom model was used to measure the resistance of these delivery systems to advancement. Phantom experiments showed that, compared with 7Fr-bullet, 7Fr-tee had less resistance force to the advancement of the stent delivery system. EUS-BD was technically successful in all ten pigs. Fistulous tract dilation was necessary in 100% (2/2), 75% (3/4), and 0% (0/4) of the pigs that underwent EUS-BD using 7.5Fr-bullet, 7Fr-bullet, and 7Fr-tee, respectively. There were no procedure-related complications. Our newly designed metal stent may be feasible and safe for EUS-BD, particularly when delivered by 7Fr-tee, because it eliminates the need for fistulous tract dilation.

  7. The Use of Bovine Pericardial Buttress on Linear Stapler Fails to Reduce Pancreatic Fistula Incidence in a Porcine Pancreatic Transection Model

    Directory of Open Access Journals (Sweden)

    A. Maciver

    2011-01-01

    Full Text Available We investigate the effectiveness of buttressing the surgical stapler to reduce postoperative pancreatic fistulae in a porcine model. As a pilot study, pigs (n=6 underwent laparoscopic distal pancreatectomy using a standard stapler. Daily drain output and lipase were measured postoperative day 5 and 14. In a second study, pancreatic transection was performed to occlude the proximal and distal duct at the pancreatic neck using a standard stapler (n=6, or stapler with bovine pericardial strip buttress (n=6. Results. In pilot study, 3/6 animals had drain lipase greater than 3x serum on day 14. In the second series, drain volumes were not significantly different between buttressed and control groups on day 5 (55.3 ± 31.6 and 29.3 ± 14.2 cc, resp., nor on day 14 (9.5 ± 4.2 cc and 2.5 ± 0.8 cc, resp., P=0.13. Drain lipase was not statistically significant on day 5 (3,166 ± 1,433 and 6,063 ± 1,872 U/L, resp., P=0.25 or day 14 (924 ± 541 and 360 ± 250 U/L. By definition, 3/6 developed pancreatic fistula; only one (control demonstrating a contained collection arising from the staple line. Conclusion. Buttressed stapler failed to protect against pancreatic fistula in this rigorous surgical model.

  8. Vascular endothelial growth factor-A, matrix metalloproteinase-1, and macrophage migration inhibition factor changes in the porcine remnant kidney model: Evaluation by MRI

    Science.gov (United States)

    Misra, Sanjay; Misra, Khamal D; Glockner, James F.

    2010-01-01

    Purpose To determine the expression of vascular endothelial growth factor-A (VEGF-A), macrophage migration inhibition factor (MIF), and matrix metalloproteinase-1 (MMP-1) in the porcine remnant kidney model and quantify renal blood flow and volume using phase contrast magnetic resonance imaging with magnetic resonance angiography (PC MRI/MRA). Material and methods In 23 pigs, the left renal artery was completely embolized using polyvinyl acrylide (PVA) particles and the right kidney partially embolized (remnant kidney) while six pigs served as controls. The animals were sacrificed early (day 3, 7, and 14, N=3), day 24 (D24, N=5), day 37 (D37, N=3), day 42 (D42, N=9), and day 84 (D84, N=3). MRI/PC MRA of the kidneys was performed prior to sacrifice. The remnant and control kidneys were harvested for Western blotting of VEGF-A, MMP-1, and MIF. Blood was removed for BUN and creatinine prior to embolization and at time of sacrifice. Results The kidney function after the embolization was characterized by chronic renal insufficiency. The renal artery blood flow, volume, and weight of the remnant kidney increased significantly over time when compared to controls. At early time points, there was increased expression of MIF and MMP-1 followed by an increase in the expression of VEGF-A by day 37 (P<0.05 when compared to control). Masson's trichrome staining of the remnant kidney revealed scarring in the tubulointerstitial space. Conclusions In this model, renal blood flow and volume increase as the remnant kidney hypertrophies and scars. There is increased expression of MIF, VEGF-A, and MMP-1 in the remnant kidney. PMID:20610182

  9. In vitro porcine blood-brain barrier model for permeability studies: pCEL-X software pKa(FLUX) method for aqueous boundary layer correction and detailed data analysis.

    Science.gov (United States)

    Yusof, Siti R; Avdeef, Alex; Abbott, N Joan

    2014-12-18

    In vitro blood-brain barrier (BBB) models from primary brain endothelial cells can closely resemble the in vivo BBB, offering valuable models to assay BBB functions and to screen potential central nervous system drugs. We have recently developed an in vitro BBB model using primary porcine brain endothelial cells. The model shows expression of tight junction proteins and high transendothelial electrical resistance, evidence for a restrictive paracellular pathway. Validation studies using small drug-like compounds demonstrated functional uptake and efflux transporters, showing the suitability of the model to assay drug permeability. However, one limitation of in vitro model permeability measurement is the presence of the aqueous boundary layer (ABL) resulting from inefficient stirring during the permeability assay. The ABL can be a rate-limiting step in permeation, particularly for lipophilic compounds, causing underestimation of the permeability. If the ABL effect is ignored, the permeability measured in vitro will not reflect the permeability in vivo. To address the issue, we explored the combination of in vitro permeability measurement using our porcine model with the pKa(FLUX) method in pCEL-X software to correct for the ABL effect and allow a detailed analysis of in vitro (transendothelial) permeability data, Papp. Published Papp using porcine models generated by our group and other groups are also analyzed. From the Papp, intrinsic transcellular permeability (P0) is derived by simultaneous refinement using a weighted nonlinear regression, taking into account permeability through the ABL, paracellular permeability and filter restrictions on permeation. The in vitro P0 derived for 22 compounds (35 measurements) showed good correlation with P0 derived from in situ brain perfusion data (r(2)=0.61). The analysis also gave evidence for carrier-mediated uptake of naloxone, propranolol and vinblastine. The combination of the in vitro porcine model and the software

  10. Modeling of NAD+ analogues in horse liver alcohol dehydrogenase

    NARCIS (Netherlands)

    Beijer, N.A.; Buck, H.M.; Sluyterman, L.A.A.E.; Meijer, E.M.

    1990-01-01

    So far, the interactions of nicotinamide adenine dinucleotide (NAD+) derivatives with dehydrogenases are not very well understood. This hampers the introduction of NAD+ analogues with improved characteristics concerning industrial application. We have developed an AMBER molecular mechanics model in

  11. A live-attenuated chimeric porcine circovirus type 2 (PCV2) vaccine is transmitted to contact pigs but is not upregulated by concurrent infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) and is efficacious in a PCV2b-PRRSV-PPV challenge model.

    Science.gov (United States)

    Opriessnig, T; Shen, H G; Pal, N; Ramamoorthy, S; Huang, Y W; Lager, K M; Beach, N M; Halbur, P G; Meng, X J

    2011-08-01

    The live chimeric porcine circovirus type 2 (PCV2) vaccine with the capsid gene of the emerging subtype 2b cloned in the genomic backbone of the nonpathogenic PCV1 is attenuated in vivo and induces protective immunity against PCV2. To further determine the safety and efficacy of this experimental vaccine, we tested for evidence of pig-to-pig transmission by commingling nonvaccinated and vaccinated pigs, determined potential upregulation by simultaneous vaccination and infection with porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV), and determined vaccine efficacy by challenging pigs 4 weeks after vaccination with PCV2b, PRRSV, and PPV. Forty-six 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups. Twenty-nine of 46 pigs were challenged with PCV2b, PRRSV, and PPV at day 28, 8/46 remained nonvaccinated and nonchallenged and served as negative controls, and 9/46 remained nonchallenged and served as vaccination controls. All animals were necropsied at day 49. PCV1-PCV2 viremia was detected in nonvaccinated contact pigs commingled with vaccinated pigs, indicating pig-to-pig transmission; however, PCV1-PCV2 DNA levels remained low in all vaccinated and contact pigs regardless of concurrent infection. Finally, vaccination 28 days before challenge resulted in significantly (P attenuated chimeric PCV2 vaccine, although transmissible to contact pigs, remains attenuated in pigs concurrently infected with PRRSV and PPV and induces protective immunity against PCV2b when it is administered 28 days before PCV2 exposure.

  12. Porcine prion protein amyloid.

    Science.gov (United States)

    Hammarström, Per; Nyström, Sofie

    2015-01-01

    Mammalian prions are composed of misfolded aggregated prion protein (PrP) with amyloid-like features. Prions are zoonotic disease agents that infect a wide variety of mammalian species including humans. Mammals and by-products thereof which are frequently encountered in daily life are most important for human health. It is established that bovine prions (BSE) can infect humans while there is no such evidence for any other prion susceptible species in the human food chain (sheep, goat, elk, deer) and largely prion resistant species (pig) or susceptible and resistant pets (cat and dogs, respectively). PrPs from these species have been characterized using biochemistry, biophysics and neurobiology. Recently we studied PrPs from several mammals in vitro and found evidence for generic amyloidogenicity as well as cross-seeding fibril formation activity of all PrPs on the human PrP sequence regardless if the original species was resistant or susceptible to prion disease. Porcine PrP amyloidogenicity was among the studied. Experimentally inoculated pigs as well as transgenic mouse lines overexpressing porcine PrP have, in the past, been used to investigate the possibility of prion transmission in pigs. The pig is a species with extraordinarily wide use within human daily life with over a billion pigs harvested for human consumption each year. Here we discuss the possibility that the largely prion disease resistant pig can be a clinically silent carrier of replicating prions.

  13. Development of a new auxiliary heterotopic partial liver transplantation technique using a liver cirrhosis model in minipigs: Preliminary report of eight transplants

    Science.gov (United States)

    ZHANG, JUN-JING; NIU, JIAN-XIANG; YUE, GEN-QUAN; ZHONG, HAI-YAN; MENG, XING-KAI

    2012-01-01

    This study aimed to develop a new auxiliary heterotopic partial liver transplantation (AHPLT) technique in minipigs using a model of liver cirrhosis. Based on our previous study, 14 minipigs were induced to cirrhosis by administration of carbon tetrachloride (CCl4) through intraperitoneal injection. All of the cirrhotic animals were utilized as recipients. The donor’s liver was placed on the recipient’s splenic bed, and the anastomosis was performed as follows: end-to-end anastomosis between the donor’s portal vein and the recipient’s splenic vein, end-to-side anastomosis between the donor’s suprahepatic vena cava and the recipient’s suprahepatic vena cava, and end-to-end anastomosis between the donor’s hepatic artery and the recipient’s splenic artery. The common bile duct of the donor was intubated and bile was collected with an extracorporeal bag. Vital signs, portal vein pressure (PVP), hepatic venous pressure (HVP) and portal vein pressure gradient (PVPG) were monitored throughout the transplantation. All 8 minipigs that developed liver cirrhosis were utilized to establish the new AHPLT; 7 cases survived. Following the surgical intervention, the PVP and PVPG of the recipients were lower than those prior to the operation (P<0.05), whereas the PVP and PVPG of the donors increased significantly compared to those of the normal animals (P<0.05). A new operative technique for AHPLT has been successfully described herein using a model of liver cirrhosis. PMID:22969983

  14. Ursodeoxycholic acid inhibits hepatic cystogenesis in experimental models of polycystic liver disease.

    Science.gov (United States)

    Munoz-Garrido, Patricia; Marin, José J G; Perugorria, María J; Urribarri, Aura D; Erice, Oihane; Sáez, Elena; Úriz, Miriam; Sarvide, Sarai; Portu, Ainhoa; Concepcion, Axel R; Romero, Marta R; Monte, María J; Santos-Laso, Álvaro; Hijona, Elizabeth; Jimenez-Agüero, Raúl; Marzioni, Marco; Beuers, Ulrich; Masyuk, Tatyana V; LaRusso, Nicholas F; Prieto, Jesús; Bujanda, Luis; Drenth, Joost P H; Banales, Jesús M

    2015-10-01

    Polycystic liver diseases (PLDs) are genetic disorders characterized by progressive biliary cystogenesis. Current therapies show short-term and/or modest beneficial effects. Cystic cholangiocytes hyperproliferate as a consequence of diminished intracellular calcium levels ([Ca(2+)]i). Here, the therapeutic value of ursodeoxycholic acid (UDCA) was investigated. Effect of UDCA was examined in vitro and in polycystic (PCK) rats. Hepatic cystogenesis and fibrosis, and the bile acid (BA) content were evaluated from the liver, bile, serum, and kidneys by HPLC-MS/MS. Chronic treatment of PCK rats with UDCA inhibits hepatic cystogenesis and fibrosis, and improves their motor behaviour. As compared to wild-type animals, PCK rats show increased BA concentration ([BA]) in liver, similar hepatic Cyp7a1 mRNA levels, and diminished [BA] in bile. Likewise, [BA] is increased in cystic fluid of PLD patients compared to their matched serum levels. In PCK rats, UDCA decreases the intrahepatic accumulation of cytotoxic BA, normalizes their diminished [BA] in bile, increases the BA secretion in bile and diminishes the increased [BA] in kidneys. In vitro, UDCA inhibits the hyperproliferation of polycystic human cholangiocytes via a PI3K/AKT/MEK/ERK1/2-dependent mechanism without affecting apoptosis. Finally, the presence of glycodeoxycholic acid promotes the proliferation of polycystic human cholangiocytes, which is inhibited by both UDCA and tauro-UDCA. UDCA was able to halt the liver disease of a rat model of PLD through inhibiting cystic cholangiocyte hyperproliferation and decreasing the levels of cytotoxic BA species in the liver, which suggests the use of UDCA as a potential therapeutic tool for PLD patients. Copyright © 2015 European Association for the Study of the Liver. All rights reserved.

  15. Utility of (11)C-methionine and (11)C-donepezil for imaging of Staphylococcus aureus induced osteomyelitis in a juvenile porcine model

    DEFF Research Database (Denmark)

    Afzelius, Pia; Alstrup, Aage Ko; Schønheyder, Henrik C

    2016-01-01

    in the right femoral artery with a porcine strain of Staphylococcus aureus. The sequential scan protocol included Computed Tomography, (11)C-methionine and (11)C-donepezil PET, (99m) Tc-DPD and (111)In-labelled leukocytes scintigraphy, and (18)F-FDG PET. This was followed by necropsy of the pigs and gross...

  16. Simulating the Risk of Liver Fluke Infection using a Mechanistic Hydro-epidemiological Model

    Science.gov (United States)

    Beltrame, Ludovica; Dunne, Toby; Rose, Hannah; Walker, Josephine; Morgan, Eric; Vickerman, Peter; Wagener, Thorsten

    2016-04-01

    Liver Fluke (Fasciola hepatica) is a common parasite found in livestock and responsible for considerable economic losses throughout the world. Risk of infection is strongly influenced by climatic and hydrological conditions, which characterise the host environment for parasite development and transmission. Despite on-going control efforts, increases in fluke outbreaks have been reported in recent years in the UK, and have been often attributed to climate change. Currently used fluke risk models are based on empirical relationships derived between historical climate and incidence data. However, hydro-climate conditions are becoming increasingly non-stationary due to climate change and direct anthropogenic impacts such as land use change, making empirical models unsuitable for simulating future risk. In this study we introduce a mechanistic hydro-epidemiological model for Liver Fluke, which explicitly simulates habitat suitability for disease development in space and time, representing the parasite life cycle in connection with key environmental conditions. The model is used to assess patterns of Liver Fluke risk for two catchments in the UK under current and potential future climate conditions. Comparisons are made with a widely used empirical model employing different datasets, including data from regional veterinary laboratories. Results suggest that mechanistic models can achieve adequate predictive ability and support adaptive fluke control strategies under climate change scenarios.

  17. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    International Nuclear Information System (INIS)

    Li, YanHua; Li, AiHua; Yang, Z.Q.

    2016-01-01

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  18. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    Energy Technology Data Exchange (ETDEWEB)

    Li, YanHua, E-mail: liyanhua.1982@aliyun.com [Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Children’s Hospital of Chongqing Medical University, Chongqing 400014 (China); Li, AiHua [Chongqing Cancer Institute & Hospital & Cancer Center, Chongqing 404100 (China); Yang, Z.Q. [Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2016-09-09

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  19. Self-assembling peptide matrix for the prevention of esophageal stricture after endoscopic resection: a randomized controlled trial in a porcine model.

    Science.gov (United States)

    Barret, M; Bordaçahar, B; Beuvon, F; Terris, B; Camus, M; Coriat, R; Chaussade, S; Batteux, F; Prat, F

    2017-05-01

    Esophageal stricture formation after extensive endoscopic resection remains a major limitation of endoscopic therapy for early esophageal neoplasia. This study assessed a recently developed self-assembling peptide (SAP) matrix as a wound dressing after endoscopic resection for the prevention of esophageal stricture. Ten pigs were randomly assigned to the SAP or the control group after undergoing a 5-cm-long circumferential endoscopic submucosal dissection of the lower esophagus. Esophageal diameter on endoscopy and esophagogram, weight variation, and histological measurements of fibrosis, granulation tissue, and neoepithelium were assessed in each animal. The rate of esophageal stricture at day 14 was 40% in the SAP-treated group versus 100% in the control group (P = 0.2). Median interquartile range (IQR) esophageal diameter at day 14 was 8 mm (2.5-9) in the SAP-treated group versus 4 mm (3-4) in the control group (P = 0.13). The median (IQR) stricture indexes on esophagograms at day 14 were 0.32 (0.14-0.48) and 0.26 (0.14-0.33) in the SAP-treated and control groups, respectively (P = 0.42). Median (IQR) weight variation during the study was +0.2 (-7.4; +1.8) and -3.8 (-5.4; +0.6) in the SAP-treated and control groups, respectively (P = 0.9). Fibrosis, granulation tissue, and neoepithelium were not significantly different between the groups. The application of SAP matrix on esophageal wounds after a circumferential endoscopic submucosal dissection delayed the onset of esophageal stricture in a porcine model. © International Society for Diseases of the Esophagus 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Laparoendoscopic single site (LESS) in vivo suturing using a magnetic anchoring and guidance system (MAGS) camera in a porcine model: impact on ergonomics and workload.

    Science.gov (United States)

    Yin, Gang; Han, Woong Kyu; Faddegon, Stephen; Tan, Yung Khan; Liu, Zhuo-Wei; Olweny, Ephrem O; Scott, Daniel J; Cadeddu, Jeffrey A

    2013-01-01

    To compare the ergonomics and workload of the surgeon during single-site suturing while using the magnetic anchoring and guidance system (MAGS) camera vs a conventional laparoscope. Seven urologic surgeons were enrolled and divided into an expert group (n=2) and a novice group (n=5) according to their laparoendoscopic single-site (LESS) experience. Each surgeon performed 2 conventional LESS and 2 MAGS camera-assisted LESS vesicostomy closures in a porcine model. A Likert scale (scoring 1-5) questionnaire assessing workload, ergonomics, technical difficulty, visualization, and needle handling, as well as a validated National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire were used to evaluate the tasks and workloads. MAGS LESS suturing was universally favored by expert and novice surgeons compared with conventional LESS in workload (3.4 vs 4.2), ergonomics (3.4 vs 4.4), technical challenge (3.3 vs 4.3), visualization (2.4 vs 3.3), and needle handling (3.1 vs 3.9 respectively; PNASA-TLX assessments found MAGS LESS suturing significantly decreased the workload in physical demand (P=.004), temporal demand (P=.017), and effort (P=.006). External instrument clashing was significantly reduced in MAGS LESS suturing (P<.001). The total operative time of MAGS LESS suturing was comparable to that of conventional LESS (P=.89). MAGS camera technology significantly decreased surgeon workload and improved ergonomics. Nevertheless, LESS suturing and knot tying remains a challenging task that requires training, regardless of which camera is used. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Computed tomography scout views vs. conventional radiography in body-packers – Delineation of body-packs and radiation dose in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Ziegeler, Edvard, E-mail: edvard.ziegeler@campus.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Grimm, Jochen M., E-mail: jochen.grimm@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Wirth, Stefan, E-mail: tefan.wirth@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Uhl, Michael, E-mail: michael.uhl@polizei.bayern.de [Bavarian State Criminal Police Office, Maillingerstrasse 15, 80636 Munich (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Scherr, Michael K., E-mail: Michael.Scherr@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany)

    2012-12-15

    Objective: To compare abdominal computed tomography (CT) scout views with conventional radiography regarding radiation dose and delineation of drug packages in a porcine body-packer model. Materials and methods: Nine samples of illicit drugs packed in ovoid plastic containers were consecutively placed in the rectum of a 121.5 kg pig cadaver. Antero-posterior and lateral scout views were obtained at 120 kVp and 80 mA, 150 mA and 200 mA, respectively, using a 64-row MDCT. Scout views were compared with conventional abdominal antero-posterior radiographs (77 kV and 106 ± 13 mAs). Visibility of three body pack characteristics (wrapping, content, shape) was rated independently by two radiologists and summarized to a delineation score ranging from 0 to 9 with a score ≥6 representing sufficient delineation. Mean delineation scores were calculated for each conventional radiography and single plane scout view separately and for a combined rating of antero-posterior and lateral scout views. Results: Even the lowest single plane scout view delineation score (5.3 ± 2.0 for 80 mA lateral; 0.4 mSv; sensitivity = 44%) was significantly higher than for conventional radiographs (3.1 ± 2.5, p < 0.001; 2.4 ± 0.3 mSv; sensitivity = 11%). Combined reading of antero-posterior and lateral scout views 80 mA yielded sufficient delineation (6.2 ± 1.4; 0.8 mSv; sensitivity = 56%). Conclusions: All CT scout views showed significantly better delineation ratings and sensitivity than conventional radiographs. Scout views in two planes at 80 mA provided a sufficient level of delineation and a sensitivity five times higher than conventional radiography at less than one third of the radiation dose. In case of diagnostic insecurity, CT can be performed without additional logistical effort.

  2. Does treatment of split-thickness skin grafts with negative-pressure wound therapy improve tissue markers of wound healing in a porcine experimental model?

    Science.gov (United States)

    Ward, Christopher; Ciraulo, David; Coulter, Michael; Desjardins, Steven; Liaw, Lucy; Peterson, Sarah

    2012-08-01

    Negative-pressure wound therapy (NPWT) has been used for to treat wounds for more than 15 years and, more recently, has been used to secure split-thickness skin grafts. There are some data to support this use of NPWT, but the actual mechanism by which NPWT speeds healing or improves skin graft take is not entirely known. The purpose of this project was to assess whether NPWT improved angiogenesis, wound healing, or graft survival when compared with traditional bolster dressings securing split-thickness skin grafts in a porcine model. We performed two split-thickness skin grafts on each of eight 30 kg Yorkshire pigs. We took graft biopsies on postoperative days 2, 4, 6, 8, and 10 and submitted the samples for immunohistochemical staining, as well as standard hematoxylin and eosin staining. We measured the degree of vascular ingrowth via immunohistochemical staining for von Willenbrand's factor to better identify blood vessel epithelium. We determined the mean cross-sectional area of blood vessels present for each representative specimen, and then compared the bolster and NPWT samples. We also assessed each graft for incorporation and survival at postoperative day 10. Our analysis of the data revealed that there was no statistically significant difference in the degree of vascular ingrowth as measured by mean cross-sectional capillary area (p = 0.23). We did not note any difference in graft survival or apparent incorporation on a macroscopic level, although standard hematoxylin and eosin staining indicated that microscopically, there seemed to be better subjective graft incorporation in the NPWT samples and a nonsignificant trend toward improved graft survival in the NPWT group. We were unable to demonstrate a significant difference in vessel ingrowth when comparing NPWT and traditional bolster methods for split-thickness skin graft fixation. More studies are needed to elucidate the manner by which NPWT exerts its effects and the true clinical magnitude of these

  3. Ti-24Nb-4Zr-8Sn Alloy Pedicle Screw Improves Internal Vertebral Fixation by Reducing Stress-Shielding Effects in a Porcine Model.

    Science.gov (United States)

    Qu, Yang; Zheng, Shuang; Dong, Rongpeng; Kang, Mingyang; Zhou, Haohan; Zhao, Dezhi; Zhao, Jianwu

    2018-01-01

    To ensure the biomechanical properties of Ti-24Nb-4Zr-8Sn, stress-shielding effects were compared between Ti-24Nb-4Zr-8Sn and Ti-6Al-4V fixation by using a porcine model. Twelve thoracolumbar spines (T12-L5) of 12-month-old male pigs were randomly divided into two groups: Ti-24Nb-4Zr-8Sn (EG, n = 6) and Ti-6Al-4V (RG, n = 6) fixation. Pedicle screw was fixed at the outer edge of L4-5 vertebral holes. Fourteen measuring points were selected on the front of transverse process and middle and posterior of L4-5 vertebra. Electronic universal testing machine was used to measure the strain resistance of measuring points after forward and backward flexion loading of 150 N. Meanwhile, stress resistance was compared between both groups. The strain and stress resistance of measurement points 1, 2, 5, 6, 9, and 10-14 in Ti-24Nb-4Zr-8Sn fixation was lower than that of Ti-6Al-4V fixation after forward and backward flexion loading ( P Ti-24Nb-4Zr-8Sn fixation than that of Ti-6Al-4V fixation ( P Ti-24Nb-4Zr-8Sn internal fixation were less than that of Ti-6Al-4V internal fixation. These results suggest that Ti-24Nb-4Zr-8Sn elastic fixation has more biomechanical goals than conventional Ti-6Al-4V internal fixation by reducing stress-shielding effects.

  4. Comparison of Different Compression to Ventilation Ratios (2: 1, 3: 1, and 4: 1) during Cardiopulmonary Resuscitation in a Porcine Model of Neonatal Asphyxia.

    Science.gov (United States)

    Pasquin, Matteo P; Cheung, Po-Yin; Patel, Sparsh; Lu, Min; Lee, Tze-Fun; Wagner, Michael; O'Reilly, Megan; Schmölzer, Georg M

    2018-04-12

    High-quality chest compression is essential during neonatal cardiopulmonary resuscitation (CPR). However, the optimal compression to ventilation ratio (C:V) that should be used during neonatal CPR to optimize coronary and cerebral perfusion while providing adequate ventilation remains unknown. We hypothesized that different C:V ratios (e.g., 2: 1 or 4: 1) will reduce the time to return of spontaneous circulation (ROSC) in severely asphyxiated piglets. Thirty-one newborn piglets (1-4 days old) were anesthetized, intubated, instrumented, and exposed to 50-min normocapnic hypoxia followed by asphyxia. Piglets were randomized into 4 groups: 2: 1 (n = 8), 3: 1 (n = 8), 4: 1 (n = 8) C:V ratio, or a sham group (n = 7). Cardiac function, carotid blood flow, cerebral oxygenation, and respiratory parameters were continuously recorded throughout the experiment. Thirty-one piglets were included in the study, and there was no difference in the duration of asphyxia or the degree of asphyxiation (as indicated by pH, PaCO2, and lactate) among the different groups. The median (IQR) time to ROSC was similar between the groups with 127 (82-210), 96 (88-126), and 119 (83-256) s in the 2: 1, 3: 1, and 4: 1 C:V ratio groups, respectively (p = 0.67 between groups). Similarly, there was no difference in 100% oxygen requirement or epinephrine administration between the experimental groups. Different C:V ratios resulted in similar ROSC, mortality, oxygen, and epinephrine administration during resuscitation in a porcine model of neonatal asphyxia. © 2018 S. Karger AG, Basel.

  5. Chest Compressions during Sustained Inflations Improve Recovery When Compared to a 3:1 Compression:Ventilation Ratio during Cardiopulmonary Resuscitation in a Neonatal Porcine Model of Asphyxia.

    Science.gov (United States)

    Li, Elliott S; Görens, Immanuel; Cheung, Po-Yin; Lee, Tze-Fun; Lu, Min; O'Reilly, Megan; Schmölzer, Georg M

    2017-01-01

    Recently, sustained inflations (SI) during chest compression (CC) (CC+SI) have been suggested as an alternative to the current approach during neonatal resuscitation. No previous study compared CC+SI using CC rates of 90/min to the current 3:1 compression:ventilation ratio (C:V). To determine whether CC+SI versus a 3:1 C:V reduces the time to the return of spontaneous circulation (ROSC) and improves hemodynamic recovery in newborn piglets with asphyxia-induced bradycardia. Term newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-min normocapnic hypoxia followed by asphyxia. Cardiopulmonary resuscitation (CPR) was initiated when the heart rate decreased to 25% of baseline. Piglets were randomized into 3 groups: CC during SI at a rate of 90 CC/min (SI+CC 90, n = 8), a 3:1 C:V using 90 CC and 30 inflations (3:1, n = 8), or a sham group (n = 6). Cardiac function, carotid blood flow, cerebral oxygenation, and respiratory parameters were continuously recorded throughout the experiment. CC+SI significantly reduced the median (IQR) time of ROSC, i.e., 34 s (28-156 s) versus 210 s (72-300 s) in the 3:1 group (p = 0.048). CC+SI also significantly reduced the requirement for 100% oxygen, improved respiratory parameters, and resulted in a similar hemodynamic recovery. CC+SI during CPR significantly improved ROSC in a porcine model of neonatal resuscitation. This is of considerable clinical relevance because improved respiratory and hemodynamic parameters potentially minimize morbidity and mortality in newborn infants. © 2017 S. Karger AG, Basel.

  6. Antecedent thermal injury worsens split-thickness skin graft quality: A clinically relevant porcine model of full-thickness burn, excision and grafting.

    Science.gov (United States)

    Carlsson, Anders H; Rose, Lloyd F; Fletcher, John L; Wu, Jesse C; Leung, Kai P; Chan, Rodney K

    2017-02-01

    Current standard of care for full-thickness burn is excision followed by autologous split-thickness skin graft placement. Skin grafts are also frequently used to cover surgical wounds not amenable to linear closure. While all grafts have potential to contract, clinical observation suggests that antecedent thermal injury worsens contraction and impairs functional and aesthetic outcomes. This study evaluates the impact of antecedent full-thickness burn on split-thickness skin graft scar outcomes and the potential mediating factors. Full-thickness contact burns (100°C, 30s) were created on the backs of anesthetized female Yorkshire Pigs. After seven days, burn eschar was tangentially excised and covered with 12/1000th inch (300μm) split-thickness skin graft. For comparison, unburned wounds were created by sharp excision to fat before graft application. From 7 to 120days post-grafting, planimetric measurements, digital imaging and biopsies for histology, immunohistochemistry and gene expression were obtained. At 120days post-grafting, the Observer Scar Assessment Scale, colorimetry, contour analysis and optical graft height assessments were performed. Twenty-nine porcine wounds were analyzed. All measured metrics of clinical skin quality were significantly worse (pskin graft quality, likely by multiple mechanisms including burn-related inflammation, microscopically inadequate excision, and dysregulation of tissue remodeling. A valid, reliable, clinically relevant model of full-thickness burn, excision and skin replacement therapy has been demonstrated. Future research to enhance quality of skin replacement therapies should be directed toward modulation of inflammation and assessments for complete excision. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  7. Remodelling of cardiac sympathetic re-innervation with thoracic spinal cord stimulation improves left ventricular function in a porcine model of heart failure.

    Science.gov (United States)

    Liao, Song-Yan; Liu, Yuan; Zuo, Mingliang; Zhang, Yuelin; Yue, Wensheng; Au, Ka-Wing; Lai, Wing-Hon; Wu, Yangsong; Shuto, Chika; Chen, Peter; Siu, Chung-Wah; Schwartz, Peter J; Tse, Hung-Fat

    2015-12-01

    Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear. We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05). In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  8. Modeling the relationships between quality and biochemical composition of fatty liver in mule ducks.

    Science.gov (United States)

    Theron, L; Cullere, M; Bouillier-Oudot, M; Manse, H; Dalle Zotte, A; Molette, C; Fernandez, X; Vitezica, Z G

    2012-09-01

    The fatty liver of mule ducks (i.e., French "foie gras") is the most valuable product in duck production systems. Its quality is measured by the technological yield, which is the opposite of the fat loss during cooking. The purpose of this study was to determine whether biochemical measures of fatty liver could be used to accurately predict the technological yield (TY). Ninety-one male mule ducks were bred, overfed, and slaughtered under commercial conditions. Fatty liver weight (FLW) and biochemical variables, such as DM, lipid (LIP), and protein content (PROT), were collected. To evaluate evidence for nonlinear fat loss during cooking, we compared regression models describing linear and nonlinear relations between biochemical measures and TY. We detected significantly greater (P = 0.02) linear relation between DM and TY. Our results indicate that LIP and PROT follow a different pattern (linear) than DM and showed that LIP and PROT are nonexclusive contributing factors to TY. Other components, such as carbohydrates, other than those measured in this study, could contribute to DM. Stepwise regression for TY was performed. The traditional model with FLW was tested. The results showed that the weight of the liver is of limited value in the determination of fat loss during cooking (R(2) = 0.14). The most accurate TY prediction equation included DM (in linear and quadratic terms), FLW, and PROT (R(2) = 0.43). Biochemical measures in the fatty liver were more accurate predictors of TY than FLW. The model is useful in commercial conditions because DM, PROT, and FLW are noninvasive measures.

  9. Testing the validity of a receptor kinetic model via TcNGA functional imaging of liver transplant recipients. Final report

    International Nuclear Information System (INIS)

    Stadalnik, R.C.

    1993-01-01

    The author had accomplished the expertise for I-125-HSA plasma volume, galactose clearance for determination of hepatic plasma flow as well as finalizing the kinetic model. They have just completed modifying the microscale Scatchard assay for greater precision of receptor measurement using only 5--10 mg of liver tissue. In addition, he determined during the past year that the most practical method and clinically reasonable measurement of liver volume was to measure the transplanted liver in vivo using Tc-NGA images in the anterior, posterior, and right lateral projections, using the method of Rollo and DeLand. Direct measurement of liver weight obtained during transplant operation was not reliable due to variability of fluid retention in the donor liver secondary to ischemia, preservation fluid, etc., which thereby did not reflect an accurate liver weight which is needed in the kinetic analysis comparison, i.e., V h (hepatic plasma volume)

  10. Combined endeavor of Neutrosophic Set and Chan-Vese model to extract accurate liver image from CT scan.

    Science.gov (United States)

    Siri, Sangeeta K; Latte, Mrityunjaya V

    2017-11-01

    Many different diseases can occur in the liver, including infections such as hepatitis, cirrhosis, cancer and over effect of medication or toxins. The foremost stage for computer-aided diagnosis of liver is the identification of liver region. Liver segmentation algorithms extract liver image from scan images which helps in virtual surgery simulation, speedup the diagnosis, accurate investigation and surgery planning. The existing liver s