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Sample records for monitored porcine model

  1. Evaluation of a Model-Based Hemodynamic Monitoring Method in a Porcine Study of Septic Shock

    PubMed Central

    Revie, James A.; Stevenson, David; Chase, J. Geoffrey; Pretty, Chris J.; Lambermont, Bernard C.; Ghuysen, Alexandre; Kolh, Philippe; Shaw, Geoffrey M.; Desaive, Thomas

    2013-01-01

    Introduction. The accuracy and clinical applicability of an improved model-based system for tracking hemodynamic changes is assessed in an animal study on septic shock. Methods. This study used cardiovascular measurements recorded during a porcine trial studying the efficacy of large-pore hemofiltration for treating septic shock. Four Pietrain pigs were instrumented and induced with septic shock. A subset of the measured data, representing clinically available measurements, was used to identify subject-specific cardiovascular models. These models were then validated against the remaining measurements. Results. The system accurately matched independent measures of left and right ventricle end diastolic volumes and maximum left and right ventricular pressures to percentage errors less than 20% (except for the 95th percentile error in maximum right ventricular pressure) and all R2 > 0.76. An average decrease of 42% in systemic resistance, a main cardiovascular consequence of septic shock, was observed 120 minutes after the infusion of the endotoxin, consistent with experimentally measured trends. Moreover, modelled temporal trends in right ventricular end systolic elastance and afterload tracked changes in corresponding experimentally derived metrics. Conclusions. These results demonstrate that this model-based method can monitor disease-dependent changes in preload, afterload, and contractility in porcine study of septic shock. PMID:23585774

  2. Porcine cancer models for translational oncology

    PubMed Central

    Sieren, Jessica C.; Quelle, Dawn; Meyerholz, David K.; Rogers, Christopher S.

    2014-01-01

    Large-animal cancer models are needed to advance the development of innovative and clinically applicable tumor diagnostic, therapeutic, and monitoring technologies. We developed a genetically modified porcine model of cancer based on a TP53 mutation, and established its utility for tracking tumorigenesis in vivo through non-invasive clinical imaging approaches. PMID:27308376

  3. Noninvasive carbon dioxide monitoring in a porcine model of acute lung injury due to smoke inhalation and burns.

    PubMed

    Belenkiy, Slava; Ivey, Katherine M; Batchinsky, Andriy I; Langer, Thomas; Necsoiu, Corina; Baker, William; Salinas, José; Cancio, Leopoldo C

    2013-06-01

    In critically ill intubated patients, assessment of adequacy of ventilation relies on measuring partial pressure of arterial carbon dioxide (PaCO2), which requires invasive arterial blood gas analysis. Alternative noninvasive technologies include transcutaneous CO2 (tPCO2) and end-tidal CO2 (EtCO2) monitoring. We evaluated accuracy of tPCO2 and EtCO2 monitoring in a porcine model of acute lung injury (ALI) due to smoke inhalation and burns. Eight anesthetized Yorkshire pigs underwent mechanical ventilation, wood-bark smoke inhalation injury, and 40% total body surface area thermal injury. tPCO2 was measured with a SenTec system (SenTec AG, Therwil, Switzerland) and EtCO2 with a Capnostream-20 (Oridion Medical, Jerusalem, Israel). These values were compared with PaCO2 measurements from an arterial blood gas analyzer. Paired measurements of EtCO2-PaCO2 (n = 276) and tPCO2-PaCO2 (n = 250) were recorded in the PaCO2 range of 25 to 85 mmHg. Overlapping data sets were analyzed based on respiratory and hemodynamic status of animals. Acute lung injury was defined as PaO2/FIO2 ≤ 300 mmHg; hemodynamic instability was defined as mean arterial pressure ≤ 60 mmHg. Before ALI, EtCO2 demonstrated moderate correlation with PaCO2 (R = 0.45; P < 0.0001), which deteriorated after onset of ALI (R = 0.12; P < 0.0001). Before ALI, tPCO2 demonstrated moderate correlation (R = 0.51, P < 0.0001), which was sustained after onset of ALI (R = 0.78; P < 0.0001). During hemodynamic stability, EtCO2 demonstrated moderate correlation with PaCO2 (R = 0.44; P < 0.0001). During hemodynamic instability, EtCO2 did not correlate with PaCO2 (R = 0.03; P = 0.29). tPCO2 monitoring demonstrated strong correlation with PaCO2 during hemodynamic stability (R = 0.80, P < 0.0001), which deteriorated under hemodynamically unstable conditions (R = 0.39; P < 0.0001). Noninvasive carbon dioxide monitors are acceptable for monitoring trends in PaCO2 under conditions of hemodynamic and pulmonary stability. Under

  4. A porcine model of osteosarcoma

    PubMed Central

    Saalfrank, A; Janssen, K-P; Ravon, M; Flisikowski, K; Eser, S; Steiger, K; Flisikowska, T; Müller-Fliedner, P; Schulze, É; Brönner, C; Gnann, A; Kappe, E; Böhm, B; Schade, B; Certa, U; Saur, D; Esposito, I; Kind, A; Schnieke, A

    2016-01-01

    We previously produced pigs with a latent oncogenic TP53 mutation. Humans with TP53 germline mutations are predisposed to a wide spectrum of early-onset cancers, predominantly breast, brain, adrenal gland cancer, soft tissue sarcomas and osteosarcomas. Loss of p53 function has been observed in >50% of human cancers. Here we demonstrate that porcine mesenchymal stem cells (MSCs) convert to a transformed phenotype after activation of latent oncogenic TP53R167H and KRASG12D, and overexpression of MYC promotes tumorigenesis. The process mimics key molecular aspects of human sarcomagenesis. Transformed porcine MSCs exhibit genomic instability, with complex karyotypes, and develop into sarcomas on transplantation into immune-deficient mice. In pigs, heterozygous knockout of TP53 was sufficient for spontaneous osteosarcoma development in older animals, whereas homozygous TP53 knockout resulted in multiple large osteosarcomas in 7–8-month-old animals. This is the first report that engineered mutation of an endogenous tumour-suppressor gene leads to invasive cancer in pigs. Unlike in Trp53 mutant mice, osteosarcoma developed in the long bones and skull, closely recapitulating the human disease. These animals thus promise a model for juvenile osteosarcoma, a relatively uncommon but devastating disease. PMID:26974205

  5. Tissue Sampling Guides for Porcine Biomedical Models.

    PubMed

    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. PMID:26883152

  6. Porcine models of muscular dystrophy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duchenne muscular dystrophy is a progressive, fatal, X-linked disease caused by a failure to accumulate the cytoskeletal protein, dystrophin. This disease is modeled by a variety of animal models including several fish models, mice, rats, and dogs. While these models have contributed substantially t...

  7. Porcine Models of Muscular Dystrophy1

    PubMed Central

    Selsby, Joshua T.; Ross, Jason W.; Nonneman, Dan; Hollinger, Katrin

    2015-01-01

    Duchenne muscular dystrophy is a progressive, fatal, X-linked disease caused by a failure to accumulate the cytoskeletal protein dystrophin. This disease has been studied using a variety of animal models including fish, mice, rats, and dogs. While these models have contributed substantially to our mechanistic understanding of the disease and disease progression, limitations inherent to each model have slowed the clinical advancement of therapies, which necessitates the development of novel large-animal models. Several porcine dystrophin-deficient models have been identified, although disease severity may be so severe as to limit their potential contributions to the field. We have recently identified and completed the initial characterization of a natural porcine model of dystrophin insufficiency. Muscles from these animals display characteristic focal necrosis concomitant with decreased abundance and localization of dystrophin-glycoprotein complex components. These pigs recapitulate many of the cardinal features of muscular dystrophy, have elevated serum creatine kinase activity, and preliminarily appear to display altered locomotion. They also suffer from sudden death preceded by EKG abnormalities. Pig dystrophinopathy models could allow refinement of dosing strategies in human-sized animals in preparation for clinical trials. From an animal handling perspective, these pigs can generally be treated normally, with the understanding that acute stress can lead to sudden death. In summary, the ability to create genetically modified pig models and the serendipitous discovery of genetic disease in the swine industry has resulted in the emergence of new animal tools to facilitate the critical objective of improving the quality and length of life for boys afflicted with such a devastating disease. PMID:25991703

  8. Porcine survival model to simulate acute upper gastrointestinal bleedings.

    PubMed

    Prosst, Ruediger L; Schurr, Marc O; Schostek, Sebastian; Krautwald, Martina; Gottwald, Thomas

    2016-06-01

    The existing animal models used for the simulation of acute gastrointestinal bleedings are usually non-survival models. We developed and evaluated a new porcine model (domestic pig, German Landrace) in which the animal remains alive and survives the artificial bleeding without any cardiovascular impairment. This consists of a bleeding catheter which is implanted into the stomach, then subcutaneously tunnelled from the abdomen to the neck where it is exteriorized and fixed with sutures. Using the injection of porcine blood, controllable and reproducible acute upper gastrointestinal bleeding can be simulated while maintaining normal gastrointestinal motility and physiology. Depending on the volume of blood applied through the gastric catheter, the bleeding intensity can be varied from traces of blood to a massive haemorrhage. This porcine model could be valuable, e.g. for testing the efficacy of new bleeding diagnostics in large animals before human use. PMID:26306615

  9. LUMOR: an app for standardized control and monitoring of a porcine lung and its nutrient cycle.

    PubMed

    Lenz, Gregor; Frohner, Matthias; Sauermann, Stefan; Forjan, Mathias

    2014-01-01

    The outcome of the EU-funded project ElBik has been the lung simulator 'iLung', which imitates an actively breathing human lung with a porcine lung. In order to keep the explanted lung in a nearly physiological state during transportation from the slaughterhouse to the ventilation laboratory the tissue needs to be nourished and temperature controlled. The Project AlveoPic designs a mobile transport vehicle implementing an ISO/IEEE 11073-20601 compliant communication interface for the exchange of the physical parameters, alert messages and setpoint-values. An appropriate 11073 domain information model is designed and limitations of the defined services and attributes are identified. For monitoring purposes the Android App LUMOR is implemented providing a user with an easy-to-handle GUI. It was found, that alert capabilities and remote set features are not well supported in ISO/IEEE 11073-20601 at the moment and possible workarounds are discussed. PMID:24825688

  10. Development of a Porcine Model of Cystic Fibrosis

    PubMed Central

    Welsh, Michael J.; Rogers, Christopher S.; Stoltz, David A.; Meyerholz, David K.; Prather, Randall S.

    2009-01-01

    Cystic Fibrosis (CF) is a common autosomal recessive disease that affects multiple organs. The lack of an animal model with manifestations like those typically found in humans has slowed understanding of its pathogenesis. Therefore, because of the similarities between human and swine anatomy, biochemistry, physiology, size, and genetics, we chose to develop a porcine model of CF. We used homologous recombination in primary cultures of porcine fibroblasts to disrupt the CFTR gene and then used those cells as nuclear donors for somatic cell nuclear transfer. After crossing heterozygous pigs, we produced CFTR−/− pigs. The newborn CFTR null piglets manifested meconium ileus, pancreatic destruction, early focal biliary cirrhosis, and gall bladder abnormalities that were very similar to those observed in humans with CF. At birth, there were no abnormalities in the airway epithelium or submucosal glands and no evidence of inflammation, consistent with findings in the newborn human. We hope that this porcine model will help elucidate the pathogenesis of CF and thereby lead to the development of new mechanism-based therapies. PMID:19768173

  11. Development of a porcine model of cystic fibrosis.

    PubMed

    Welsh, Michael J; Rogers, Christopher S; Stoltz, David A; Meyerholz, David K; Prather, Randall S

    2009-01-01

    Cystic Fibrosis (CF) is a common autosomal recessive disease that affects multiple organs. The lack of an animal model with manifestations like those typically found in humans has slowed understanding of its pathogenesis. Therefore, because of the similarities between human and swine anatomy, biochemistry, physiology, size, and genetics, we chose to develop a porcine model of CF. We used homologous recombination in primary cultures of porcine fibroblasts to disrupt the CFTR gene and then used those cells as nuclear donors for somatic cell nuclear transfer. After crossing heterozygous pigs, we produced CFTR-/- pigs. The newborn CFTR null piglets manifested meconium ileus, pancreatic destruction, early focal biliary cirrhosis, and gall bladder abnormalities that were very similar to those observed in humans with CF. At birth, there were no abnormalities in the airway epithelium or submucosal glands and no evidence of inflammation, consistent with findings in the newborn human. We hope that this porcine model will help elucidate the pathogenesis of CF and thereby lead to the development of new mechanism-based therapies. PMID:19768173

  12. A Porcine Pneumothorax Model for Teaching Ultrasound Diagnostics

    PubMed Central

    Oveland, Nils Petter; Sloth, Erik; Andersen, Gratien; Lossius, Hans Morten

    2012-01-01

    Objectives: Ultrasound (US) is a sensitive diagnostic tool for detecting pneumothorax (PTX), but methods are needed to optimally teach this technique outside of direct patient care. In training and research settings, porcine PTX models are sometimes used, but the description of the PTX topography in these models is lacking. The study purpose was to define the distribution of air using the reference imaging standard computed tomography (CT), to see if pleural insufflation of air into a live anaesthetized pig truly imitates a PTX in an injured patient. Methods: A unilateral catheter was inserted into one pleural cavity of each of 20 pigs, and 500 mL of air was insufflated. After a complete thoracic CT scan, the anterior, lateral, medial, basal, apical, and posterior components of the PTXs were compared. The amount of air in each location was quantified by measuring the distance from the lung edge to the chest wall (LE-CW). A supine anteroposterior chest radiograph (CXR) was taken from each model and interpreted by a senior radiologist, and the image results were compared to CT. Results: All 20 hemithoraces with PTX were correctly identified by CT, while six remained occult after interpreting the CXRs. The PTXs were anterior (100%), lateral (95%), medial (80%), basal (60%), apical (45%), and posterior (15%). The major proportion of the insufflated 500-mL volume was found in the anterior, medial, and basal recesses. Conclusions: The authors found the distribution of the intrathoracic air to be similar between a porcine model and that to be expected in human trauma patients, all having predominantly anterior PTX topographies. In a training facility, the model is easy to set up and can be scanned by the participants multiple times. To acquire the necessary skills to perform thoracic US examinations for PTX, the porcine models could be useful. PMID:22594363

  13. In vivo porcine training model for cranial neurosurgery.

    PubMed

    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. PMID:25240530

  14. The porcine lung as a potential model for cystic fibrosis

    PubMed Central

    Rogers, Christopher S.; Abraham, William M.; Brogden, Kim A.; Engelhardt, John F.; Fisher, John T.; McCray, Paul B.; McLennan, Geoffrey; Meyerholz, David K.; Namati, Eman; Ostedgaard, Lynda S.; Prather, Randall S.; Sabater, Juan R.; Stoltz, David Anthony; Zabner, Joseph; Welsh, Michael J.

    2008-01-01

    Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF. PMID:18487356

  15. The porcine lung as a potential model for cystic fibrosis.

    PubMed

    Rogers, Christopher S; Abraham, William M; Brogden, Kim A; Engelhardt, John F; Fisher, John T; McCray, Paul B; McLennan, Geoffrey; Meyerholz, David K; Namati, Eman; Ostedgaard, Lynda S; Prather, Randall S; Sabater, Juan R; Stoltz, David Anthony; Zabner, Joseph; Welsh, Michael J

    2008-08-01

    Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF. PMID:18487356

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

    PubMed

    Andrews, Christine J; 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

  17. Use of an Ex Vivo Porcine Mucosal Model to Study Superantigen Penetration.

    PubMed

    Squier, Christopher A; Mantz, Mary J

    2016-01-01

    In vitro perfusion studies are frequently used to determine the penetration of compounds through skin and mucosa. Porcine tissue has been shown to be an excellent model for human tissue in terms of structure, function, and reactivity. We describe the use of porcine tissue ex-vivo in a continuous flow perfusion system to study the behavior of superantigens in this model. PMID:26676044

  18. MR Monitoring of Minimally Invasive Delivery of Mesenchymal Stem Cells into the Porcine Intervertebral Disc

    PubMed Central

    Barczewska, Monika; Wojtkiewicz, Joanna; Habich, Aleksandra; Janowski, Miroslaw; Adamiak, Zbigniew; Holak, Piotr; Matyjasik, Hubert; Bulte, Jeff W. M.; Maksymowicz, Wojciech; Walczak, Piotr

    2013-01-01

    Purpose Bone marrow stem cell therapy is a new, attractive therapeutic approach for treatment of intervertebral disc (IVD) degeneration; however, leakage and backflow of transplanted cells into the structures surrounding the disc may lead to the formation of undesirable osteophytes. The purpose of this study was to develop a technique for minimally invasive and accurate delivery of stem cells. Methods Porcine mesenchymal stem cells (MSCs) were labeled with superparamagnetic iron oxide nanoparticles (SPIO, Molday ION rhodamine) and first injected into the explanted swine lumbar IVD, followed by ex vivo 3T MRI. After having determined sufficient sensitivity, IVD degeneration was then induced in swine (n=3) by laser-evaporation. 3 x 106 SPIO-labeled cells embedded within hydrogel were injected in 2 doses using a transcutaneous cannula and an epidural anesthesia catheter. T2-weighted MR images were obtained at 3T before and immediately after cell infusion. Two weeks after injection, histological examination was performed for detection of transplanted cells. Results MSCs were efficiently labeled with Molday ION rhodamine. Cells could be readily detected in the injected vertebral tissue explants as distinct hypointensities with sufficient sensitivity. MR monitoring indicated that the MSCs were successfully delivered into the IVD in vivo, which was confirmed by iron-positive Prussian Blue staining of the tissue within the IVD. Conclusion We have developed a technique for non-invasive monitoring of minimally invasive stem delivery into the IVD at 3T. By using a large animal model mimicking the anatomy of IVD in humans, the present results indicate that this procedure may be clinically feasible. PMID:24058619

  19. Porcine incisional hernia model: Evaluation of biologically derived intact extracellular matrix repairs

    PubMed Central

    Delossantos, Aubrey I; Rodriguez, Neil L; Patel, Paarun; Franz, Michael G; Wagner, Christopher T

    2013-01-01

    We compared fascial wounds repaired with non-cross-linked intact porcine-derived acellular dermal matrix versus primary closure in a large-animal hernia model. Incisional hernias were created in Yucatan pigs and repaired after 3 weeks via open technique with suture-only primary closure or intraperitoneally placed porcine-derived acellular dermal matrix. Progressive changes in mechanical and biological properties of porcine-derived acellular dermal matrix and repair sites were assessed. Porcine-derived acellular dermal matrix–repaired hernias of additional animals were evaluated 2 and 4 weeks post incision to assess porcine-derived acellular dermal matrix regenerative potential and biomechanical changes. Hernias repaired with primary closure showed substantially more scarring and bone hyperplasia along the incision line. Mechanical remodeling of porcine-derived acellular dermal matrix was noted over time. Porcine-derived acellular dermal matrix elastic modulus and ultimate tensile stress were similar to fascia at 6 weeks. The biology of porcine-derived acellular dermal matrix–reinforced animals was more similar to native abdominal wall versus that with primary closure. In this study, porcine-derived acellular dermal matrix–reinforced repairs provided more complete wound healing response compared with primary closure. PMID:24555008

  20. Stent linker effect in a porcine coronary restenosis model.

    PubMed

    Park, Jun-Kyu; Lim, Kyung Seob; Bae, In-Ho; Nam, Joung-Pyo; Cho, Jae Hwa; Choi, Changyong; Nah, Jae-Woon; Jeong, Myung Ho

    2016-01-01

    In this study, we aimed to evaluate the mechanical effects of different stent linker designs on in-stent restenosis in porcine coronary arteries. We fabricated stents with an open-cell structure composed of nine main cells and three linker structures in model 1 (I-type), model 2 (S-types) and model 3 (U-types)) as well as Model 4, which is similar to a commercial bare metal stent design. The stent cells were 70 mm thick and wide, with a common symmetrical wave pattern. As the radial force increased, the number of main cells increased and the length of linker decreased. Radial force was higher in model 1, with a linear I-linker, than in models with S- or U-linkers. The flexibility measured by three-point bending showed a force of 1.09 N in model 1, 0.35 N in model 2, 0.19 N in model 3, and 0.31 N in model 4. The recoil results were similar in all models except model 4 and were related to the shape of the main cells. The foreshortening results were related to linker shape, with the lowest foreshortening observed in model 3 (U-linker). Restenosis areas in the porcine restenosis model 4 weeks after implantation were 35.4 ± 8.39% (model 1), 30.4 ± 7.56% (model 2), 40.6 ± 9.87% (model 3) and 45.1 ± 12.33% (model 4). In-stent restenosis rates measured by intravascular ultrasound (IVUS) and micro-computed tomography (micro-CT) showed similar trends as percent area stenosis measured by micro-CT. Model 2, with optimized flexibility and radial force due to its S-linker, showed significantly reduced restenosis in the animal model compared to stents with different linker designs. These results suggest that the optimal stent structure has a minimum radial force for vascular support and maximum flexibility for vascular conformability. The importance of the effects of these differences in stent design and their potential relationship with restenosis remains to be determined. PMID:26318568

  1. Laparoscopic anatrophic nephrolithotomy: feasibility study in a chronic porcine model.

    PubMed

    Kaouk, Jihad H; Gill, Inderbir S; Desai, Mihir M; Banks, Kevin L W; Raja, Shanker S; Skacel, Marek; Sung, Gyung Tak

    2003-02-01

    PURPOSE Anatrophic nephrolithotomy performed via open surgery involves incising the renal parenchyma along an avascular plane to remove a large, complex renal stone. We determined the feasibility of performing laparoscopic anatrophic nephrolithotomy in a survival porcine model. Furthermore, we present a novel technique of creating a staghorn calculus in the porcine model. MATERIALS AND METHODS After developing the technique in 3 pigs the survival study was performed in 10 consecutive animals. The procedure comprised 2 aspects. 1) We developed an animal model for staghorn calculi by retrograde injection of polyurethane (Fomo Products, Inc., Norton, Ohio) into the renal pelvis through a ureteral catheter. For a 2-week period the staghorn calculus was allowed to create hydronephrosis. 2) Laparoscopic anatrophic nephrolithotomy was done, involving control of the renal artery and vein, in situ renal hypothermia with ice slush in 1 animal, lateral renal parenchymal incision, stone extraction and suture repair of the incised collecting system and renal parenchyma. RESULTS Synthetic stone formation and laparoscopic anatrophic nephrolithotomy were successful in all 10 animals, including 1 that underwent staged bilateral anatrophic nephrolithotomy. Mean operative time for anatrophic nephrolithotomy was 125 minutes. Mean blood loss was 68 cc and mean warm ischemia time was 30 minutes (range 23 to 39). A residual small pelvicaliceal calculus was noted postoperatively in the initial 3 cases only. Thereafter, routine intraoperative ultrasonography and flexible endoscopy were done for stone localization, resulting in a stone-free rate of 100% in all 7 remaining animals. Diethylenetriamine pentaacetic acid renal scans documented improvement in the glomerular filtration rate from a mean of 26.4 ml. per minute after stone creation and hydronephrosis to 54.8 ml. per minute 4 to 5 weeks after laparoscopic anatrophic nephrolithotomy. CONCLUSIONS Laparoscopic techniques can be applied

  2. Salivary Stone Pneumatic Lithotripsy in a Live Porcine Model.

    PubMed

    Walvekar, Rohan R; Hoffman, Henry T; Kolenda, Jack; Hernandez, Stephen

    2016-06-01

    The purpose of this study is to evaluate the efficacy of endoscopic fragmentation and removal of artificial calculi in a live porcine model employing intracorporeal pneumatic lithotripsy. In this experimental study, 7 submandibular ducts were accessed and artificial calculi placed. A salivary pneumatic lithotripter probe was inserted through an interventional sialendoscope to fragment the calculi. A salivary duct catheter was then used to flush stone fragments, followed by endoscopy to assess complete fragmentation and ductal trauma. Ultimately, 7 artificial stones (3-10 mm, 4F/5F) were successfully fragmented without causing significant endoluminal trauma. Number of pulses for adequate stone fragmentation averaged 20 (range, 5-31). In all cases, stone fragments were successfully flushed out with the salivary duct catheter. Postprocedure endoscopy confirmed ductal integrity in all 7 ducts. While more studies are needed, this preliminary animal model demonstrates efficacy of endoscopic pneumatic lithotripsy for the management of sialolithiasis. PMID:27048662

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

    PubMed Central

    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. PMID:26973698

  4. Biphasic Presence of Fibrocytes in a Porcine Hypertrophic Scar Model

    PubMed Central

    Travis, Taryn E.; Mino, Matthew J.; Moffatt, Lauren T.; Mauskar, Neil A.; Prindeze, Nicholas J.; Ghassemi, Pejhman; Ramella-Roman, Jessica C.; Jordan, Marion H.; Shupp, Jeffrey W.

    2014-01-01

    Objective The duroc pig has been described as a promising animal model for use in the study of human wound healing and scar formation. However little is known about the presence and chronology of the fibrocyte cell population in the healing process of these animals. Methods Wounds known to form scar were created on red duroc swine (3“ × 3”) with a dermatome to a total depth of either 0.06“ or 0.09”. These wounds were allowed to heal completely and were biopsied at scheduled time points during the healing process. Biopsies were formalin-fixed and paraffin embedded for immunohistochemical analysis. Porcine-reactive antibodies to CD-45 and procollagen-1 and a human-reactive antibody to LSP-1 were used to detect the presence of fibrocytes in immunohistochemistry an immunocytochemistry. Results Initial immunohistochemical studies showed evidence of a biphasic presence of fibrocytes. Pigs with 0.06“ deep wounds showed positive staining for CD-45 and LSP-1 within highly cellular areas at days 2 and 4 after wounding. Additional animals with 0.09” deep wounds showed positive staining within similar areas at days 56, 70, and 113 after wounding. There was no immunohistochemical evidence of fibrocytes in skin biopsies taken at days 14, 28, or 42. Procollagen-1 staining was diffuse in all samples. Cultured cells stained for CD-45, LSP-1, and procollagen-1 by immunocytochemistry. Conclusions These data confirm that fibrocytes are indeed present in this porcine model. We conclude that these cells are present after initial wounding and later during scar formation and remodeling. We believe that this is evidence of a biphasic presence of fibrocytes, first as an acute response to skin wounding followed by later involvement in the remodeling process, prompted by continued inflammation in a deep partial thickness wound. PMID:25051518

  5. Brain microabscesses in a porcine model of Staphylococcus aureus sepsis

    PubMed Central

    2013-01-01

    Background Sepsis caused by Staphylococcus aureus often leads to brain microabscesses in humans. Animal models of haematogenous brain abscesses would be useful to study this condition in detail. Recently, we developed a model of S. aureus sepsis in pigs and here we report that brain microabscesses develop in pigs with such induced S. aureus sepsis. Twelve pigs were divided into three groups. Nine pigs received an intravenous inoculation of S. aureus once at time 0 h (group 1) or twice at time 0 h and 12 h (groups 2 and 3). In each group the fourth pig served as control. The pigs were euthanized at time 12 h (Group 1), 24 h (Group 2) and 48 h (Group 3) after the first inoculation. The brains were collected and examined histopathologically. Results All inoculated pigs developed sepsis and seven out of nine pigs developed brain microabscesses. The microabscesses contained S. aureus and were located in the prosencephalon and mesencephalon. Chorioditis and meningitis occurred from 12 h after inoculation. Conclusions Pigs with experimental S. aureus sepsis often develop brain microabscesses. The porcine brain pathology mirrors the findings in human sepsis patients. We therefore suggest the pig as a useful animal model of the development of brain microabscesses caused by S. aureus sepsis. PMID:24176029

  6. A Simple Porcine Model of Inducible Sustained Atrial Fibrillation.

    PubMed

    Lee, Anson M; Miller, Jacob R; Voeller, Rochus K; Zierer, Andreas; Lall, Shelly C; Schuessler, Richard B; Damiano, Ralph J; Melby, Spencer J

    2016-01-01

    The surgical management of atrial fibrillation (AF) is an evolving field with a history of testing various lesion sets and ablation technologies. Previous animal models of AF require a chronic intervention to make AF reliably inducible. Our objective was to create an acute, reliable, and reproducible porcine model of sustained AF. To accomplish this, 21 adult domestic pigs underwent median sternotomy. Methods to induce AF were then performed sequentially: manual stimulation, rapid pacing (200 beats per minute), and then rapid pacing of 8 beats with a cycle length of 300 milliseconds, followed by an extra stimulus at decreasing cycle lengths. If AF was not induced, burst pacing was performed at a cycle length of 90 milliseconds for 30 seconds. If AF was still not induced, intravenous neostigmine was administered, and the process was repeated. Atrial fibrillation was considered sustained after 1 minute. Attempts at AF induction were successful in 18 (86%) of 21. Atrial fibrillation was induced during manual stimulation in four (19%), during rapid pacing in five (24%), during burst pacing in five (24%), and after the administration of neostigmine in four (19%). Mean (SD) duration of AF was 3.6 (2.6) minutes. Of the 18, 14 (78%) reverted to sinus rhythm spontaneously and 4 (22%) required an antiarrhythmic. This technique of inducing AF can easily be used to evaluate new technologies and lesion sets without the need for creating a chronic animal model. PMID:26889882

  7. Validation of a vertical progression porcine burn model.

    PubMed

    Singer, Adam J; Hirth, Douglas; McClain, Steve A; Crawford, Laurie; Lin, Fubao; Clark, Richard A F

    2011-01-01

    A major potential goal of burn therapy is to limit progression of partial- to full-thickness burns. To better test therapies, the authors developed and validated a vertical progression porcine burn model in which partial-thickness burns treated with an occlusive dressing convert to full-thickness burns that heal with scarring and wound contraction. Forty contact burns were created on the backs and flanks of two young swine using a 150 g aluminum bar preheated to 70°C, 80°C, or 90°C for 20 or 30 seconds. The necrotic epidermis was removed and the burns were covered with a polyurethane occlusive dressing. Burns were photographed at 1, 24, and 48 hours as well as at 7, 14, 21, and 28 days postinjury. Full-thickness biopsies were obtained at 1, 4, 24, and 48 hours as well as at 7 and 28 days. The primary outcomes were presence of deep contracted scars and wound area 28 days after injury. Secondary outcomes were depth of injury, reepithelialization, and depth of scars. Data were compared across burn conditions using analysis of variance and χ(2) tests. Eight replicate burns were created with the aluminum bar using the following temperature/contact-time combinations: 70/20, 70/30, 80/20, 80/30, and 90/20. The percentage of burns healing with contracted scars were 70/20, 0%; 70/30, 25%; 80/20, 50%; 80/30, 75%; and 90/20, 100% (P = .05). Wound areas at 28 days by injury conditions were 70/20, 8.1 cm(2); 70/30, 7.8 cm(2); 80/20, 6.6 cm(2); 80/30, 4.9 cm(2); and 90/20, 4.8 cm(2) (P = .007). Depth of injury judged by depth of endothelial damage for the 80/20 and 80/30 burns at 1 hour was 36% and 60% of the dermal thickness, respectively. The depth of injury to the endothelial cells 1 hour after injury was inversely correlated with the degree of scar area (Pearson's correlation r = -.71, P < .001). Exposure of porcine skin to an aluminum bar preheated to 80°C for 20 or 30 seconds results initially in a partial-thickness burn that when treated with an occlusive dressing

  8. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin

    NASA Astrophysics Data System (ADS)

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C.

    2015-03-01

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure—PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery.

  9. Cavitation-enhanced delivery of insulin in agar and porcine models of human skin.

    PubMed

    Feiszthuber, Helga; Bhatnagar, Sunali; Gyöngy, Miklós; Coussios, Constantin-C

    2015-03-21

    Ultrasound-assisted transdermal insulin delivery offers a less painful and less invasive alternative to subcutaneous insulin injections. However, ultrasound-based drug delivery, otherwise known as sonophoresis, is a highly variable phenomenon, in part dependent on cavitation. The aim of the current work is to investigate the role of cavitation in transdermal insulin delivery. Fluorescently stained, soluble Actrapid insulin was placed on the surface of human skin-mimicking materials subjected to 265 kHz, 10% duty cycle focused ultrasound. A confocally and coaxially aligned 5 MHz broadband ultrasound transducer was used to detect cavitation. Two different skin models were used. The first model, 3% agar hydrogel, was insonated with a range of pressures (0.25-1.40 MPa peak rarefactional focal pressure-PRFP), with and without cavitation nuclei embedded within the agar at a concentration of 0.05% w/v. The second, porcine skin was insonated at 1.00 and 1.40 MPa PRFP. In both models, fluorescence measurements were used to determine penetration depth and concentration of delivered insulin. Results show that in agar gel, both insulin penetration depth and concentration only increased significantly in the presence of inertial cavitation, with up to a 40% enhancement. In porcine skin the amount of fluorescent insulin was higher in the epidermis of those samples that were exposed to ultrasound compared to the control samples, but there was no significant increase in penetration distance. The results underline the importance of instigating and monitoring inertial cavitation during transdermal insulin delivery. PMID:25716689

  10. Dynamic and Volumetric Variables Reliably Predict Fluid Responsiveness in a Porcine Model with Pleural Effusion

    PubMed Central

    Broch, Ole; Gruenewald, Matthias; Renner, Jochen; Meybohm, Patrick; Schöttler, Jan; Heß, Katharina; Steinfath, Markus; Bein, Berthold

    2013-01-01

    Background The ability of stroke volume variation (SVV), pulse pressure variation (PPV) and global end-diastolic volume (GEDV) for prediction of fluid responsiveness in presence of pleural effusion is unknown. The aim of the present study was to challenge the ability of SVV, PPV and GEDV to predict fluid responsiveness in a porcine model with pleural effusions. Methods Pigs were studied at baseline and after fluid loading with 8 ml kg−1 6% hydroxyethyl starch. After withdrawal of 8 ml kg−1 blood and induction of pleural effusion up to 50 ml kg−1 on either side, measurements at baseline and after fluid loading were repeated. Cardiac output, stroke volume, central venous pressure (CVP) and pulmonary occlusion pressure (PAOP) were obtained by pulmonary thermodilution, whereas GEDV was determined by transpulmonary thermodilution. SVV and PPV were monitored continuously by pulse contour analysis. Results Pleural effusion was associated with significant changes in lung compliance, peak airway pressure and stroke volume in both responders and non-responders. At baseline, SVV, PPV and GEDV reliably predicted fluid responsiveness (area under the curve 0.85 (p<0.001), 0.88 (p<0.001), 0.77 (p = 0.007). After induction of pleural effusion the ability of SVV, PPV and GEDV to predict fluid responsiveness was well preserved and also PAOP was predictive. Threshold values for SVV and PPV increased in presence of pleural effusion. Conclusions In this porcine model, bilateral pleural effusion did not affect the ability of SVV, PPV and GEDV to predict fluid responsiveness. PMID:23418546

  11. Feasibility and safety of endoscopic cryoablation at the duodenal papilla: Porcine model

    PubMed Central

    Yang, Dennis; Reinhard, Mary K; Wagh, Mihir S

    2015-01-01

    AIM: To assess the feasibility and safety of liquid nitrogen spray cryoablation at the duodenal papilla in a porcine model. METHODS: This prospective study protocol was approved by the University of Florida Institutional Animal Care and Use Committee. Six pigs underwent liquid nitrogen spray cryotherapy at the duodenal papilla. Freeze time of 20-s was applied per cycle (4 cycles/session). Survival animals (n = 4) were monitored for adverse events. Hemoglobin, white blood count, liver tests, and lipase were obtained at baseline and post-treatment. EGD was performed on day#7 to evaluate the papilla and for histology. All animals were euthanized and necropsy was performed at the end of the one-week survival period. Feasibility was defined as successful placement of the decompression tube in the duodenum, followed by delivery of spray cryotherapy to the duodenal papilla. Safety was determined by monitoring post-treatment blood tests and clinical course. Treatment effect was defined as endoscopic and histologic changes after cryotherapy. This was established by comparing endoscopic and histologic findings from mucosal biopsies prior to cryotherapy and on post-operative day (POD)#7. Full-thickness specimen was obtained post-mortem to assess depth of injury. RESULTS: Spray cryotherapy was feasible and successfully performed in all 6/6 (100%) animals. Cryospray with liquid nitrogen (four 20-s freeze-thaw cycles) at the duodenal papilla resulted in white frost formation at and around the target region. The mean procedural time was 54.5 min (range 50-58 min). All six animals studied had stable blood pressure, heart rate, and pulse oximetry measurements during the procedure. There were no significant intra-procedural adverse events. There were no significant differences in hemoglobin, white cell count, liver tests or lipase from baseline to post-cryotherapy. Survival animals were monitored daily post-operatively without any clinical ill effects from the cryotherapy. There was

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Experimental factors affecting in vitro absorption of six model compounds across porcine skin.

    PubMed

    Karadzovska, Daniela; Brooks, James D; Riviere, Jim E

    2012-10-01

    This comparative study evaluated the effect of several experimental variables on the absorption of six model [(14)C]-labeled compounds (caffeine, cortisone, diclofenac sodium, mannitol, salicylic acid, and testosterone) through porcine skin. Using static and flow-through diffusion cells, finite or infinite, saturated or unsaturated doses were applied in one of three vehicles: propylene glycol, water, and ethanol following a full factorial experimental design. The flux of each compound into the receptor phase, with or without bovine serum albumin (BSA), was monitored over 24 h. Levels of radioactivity were also determined in the stratum corneum by tape stripping and in the remaining skin. Apparent permeability coefficients (Kp) and dose absorbed were calculated and compared. The overall results emphasize the importance of experimental design and confirm previous findings that identified dose volume, saturation level and vehicle as the main sources of variation in the in vitro assessment of dermal absorption, whilst diffusion cell model and the presence/absence of BSA in the receptor phase had minimal effect. Although the acquired data do not directly reveal new mechanistic information on dermal absorption, the unique and complete study design has provided a suitable data source for the development of dermal absorption prediction models. PMID:22750544

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

    PubMed

    Zakrzewski, Silke S; Richter, Jan F; Krug, Susanne M; Jebautzke, Britta; Lee, In-Fah M; Rieger, Juliane; Sachtleben, Monika; Bondzio, Angelika; Schulzke, Jörg D; Fromm, Michael; Günzel, Dorothee

    2013-01-01

    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. PMID:24260272

  15. Improved Cell Line IPEC-J2, Characterized as a Model for Porcine Jejunal Epithelium

    PubMed Central

    Zakrzewski, Silke S.; Richter, Jan F.; Krug, Susanne M.; Jebautzke, Britta; Lee, In-Fah M.; Rieger, Juliane; Sachtleben, Monika; Bondzio, Angelika; Schulzke, Jörg D.; Fromm, Michael; Günzel, Dorothee

    2013-01-01

    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. PMID:24260272

  16. Met-myoglobin formation, accumulation, degradation, and myoglobin oxygenation monitoring based on multiwavelength attenuance measurement in porcine meat

    NASA Astrophysics Data System (ADS)

    Nguyen, Thien; Phan, Kien Nguyen; Lee, Jee-Bum; Kim, Jae Gwan

    2016-05-01

    We propose a simple, rapid, and nondestructive method to investigate formation, accumulation, and degradation of met-myoglobin (met-Mb) and myoglobin oxygenation from the interior of porcine meat. For the experiment, color photos and attenuance spectra of porcine meat (well-bled muscle, fat, and mixed) were collected daily to perform colorimetric analysis and to obtain the differences of attenuance between 578 and 567 nm (A578-A567) and between 615 and 630 nm (A630-A615), respectively. Oxy-, deoxy-, and met-myoglobin concentration changes over storage time were also calculated using Beer-Lamberts' law with reflectance intensities at 557, 582, and 630 nm. The change of A578-A567 was well matched with the change of myoglobin oxygenation, and the change of A630-A615 corresponded well with the formation and degradation of met-Mb. In addition, attenuation differences, A578-A567 and A630-A615, were able to show the formation of met-Mb earlier than colorimetric analysis. Therefore, the attenuance differences between wavelengths can be indicators for estimating myoglobin oxygenation and met-Mb formation, accumulation, and degradation, which enable us to design a simple device to monitor myoglobin activities in porcine meat.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27279391

  18. Study of Cardiac Arrest Caused by Acute Pulmonary Thromboembolism and Thrombolytic Resuscitation in a Porcine Model

    PubMed Central

    Zhao, Lian-Xing; Li, Chun-Sheng; Yang, Jun; Tong, Nan; Xiao, Hong-Li; An, Le

    2016-01-01

    Background: The success rate of resuscitation in cardiac arrest (CA) caused by pulmonary thromboembolism (PTE) is low. Furthermore, there are no large animal models that simulate clinical CA. The aim of this study was to establish a porcine CA model caused by PTE and to investigate the pathophysiology of CA and postresuscitation. Methods: This model was induced in castrated male pigs (30 ± 2 kg; n = 21) by injecting thrombi (10–15 ml) via the left external jugular vein. Computed tomographic pulmonary angiography (CTPA) was performed at baseline, CA, and return of spontaneous circulation (ROSC). After CTPA during CA, cardiopulmonary resuscitation (CPR) with thrombolysis (recombinant tissue plasminogen activator 50 mg) was initiated. Hemodynamic, respiratory, and blood gas data were monitored. Cardiac troponins T, cardiac troponin I, creatine kinase-MB, myoglobin, and brain natriuretic peptide (BNP) were measured by enzyme-linked immunosorbent assay. Data were compared between baseline and CA with paired-sample t-test and compared among different time points for survival animals with repeated measures analysis of variance. Results: Seventeen animals achieved CA after emboli injection, while four achieved CA after 5–8 ml more thrombi. Nine animals survived 6 h after CPR. CTPA showed obstruction of the pulmonary arteries. Mean aortic pressure data showed occurrence of CA caused by PTE (Z = −2.803, P = 0.002). The maximal rate of mean increase of left ventricular pressure (dp/dtmax) was statistically decreased (t = 6.315, P = 0.000, variation coefficient = 0.25), and end-tidal carbon dioxide partial pressure (PetCO2) decreased to the lowest value (t = 27.240, P = 0.000). After ROSC (n = 9), heart rate (HR) and mean right ventricular pressure (MRVP) remained different versus baseline until 2 h after ROSC (HR, P = 0.036; MRVP, P = 0.027). Myoglobin was statistically increased from CA to 1 h after ROSC (P = 0.036, 0.026, 0.009, respectively), and BNP was increased

  19. Validation of subject-specific cardiovascular system models from porcine measurements.

    PubMed

    Revie, James A; Stevenson, David J; Chase, J Geoffrey; Hann, Christopher E; Lambermont, Bernard C; Ghuysen, Alexandre; Kolh, Philippe; Shaw, Geoffrey M; Heldmann, Stefan; Desaive, Thomas

    2013-02-01

    A previously validated mathematical model of the cardiovascular system (CVS) is made subject-specific using an iterative, proportional gain-based identification method. Prior works utilised a complete set of experimentally measured data that is not clinically typical or applicable. In this paper, parameters are identified using proportional gain-based control and a minimal, clinically available set of measurements. The new method makes use of several intermediary steps through identification of smaller compartmental models of CVS to reduce the number of parameters identified simultaneously and increase the convergence stability of the method. This new, clinically relevant, minimal measurement approach is validated using a porcine model of acute pulmonary embolism (APE). Trials were performed on five pigs, each inserted with three autologous blood clots of decreasing size over a period of four to five hours. All experiments were reviewed and approved by the Ethics Committee of the Medical Faculty at the University of Liege, Belgium. Continuous aortic and pulmonary artery pressures (P(ao), P(pa)) were measured along with left and right ventricle pressure and volume waveforms. Subject-specific CVS models were identified from global end diastolic volume (GEDV), stroke volume (SV), P(ao), and P(pa) measurements, with the mean volumes and maximum pressures of the left and right ventricles used to verify the accuracy of the fitted models. The inputs (GEDV, SV, P(ao), P(pa)) used in the identification process were matched by the CVS model to errors <0.5%. Prediction of the mean ventricular volumes and maximum ventricular pressures not used to fit the model compared experimental measurements to median absolute errors of 4.3% and 4.4%, which are equivalent to the measurement errors of currently used monitoring devices in the ICU (∼5-10%). These results validate the potential for implementing this approach in the intensive care unit. PMID:22126892

  20. Porcine models of digestive disease: the future of large animal translational research.

    PubMed

    Gonzalez, Liara M; Moeser, Adam J; Blikslager, Anthony T

    2015-07-01

    There is increasing interest in nonrodent translational models for the study of human disease. The pig, in particular, serves as a useful animal model for the study of pathophysiological conditions relevant to the human intestine. This review assesses currently used porcine models of gastrointestinal physiology and disease and provides a rationale for the use of these models for future translational studies. The pig has proven its utility for the study of fundamental disease conditions such as ischemia-reperfusion injury, stress-induced intestinal dysfunction, and short bowel syndrome. Pigs have also shown great promise for the study of intestinal barrier function, surgical tissue manipulation and intervention, as well as biomaterial implantation and tissue transplantation. Advantages of pig models highlighted by these studies include the physiological similarity to human intestine and mechanisms of human disease. Emerging future directions for porcine models of human disease include the fields of transgenics and stem cell biology, with exciting implications for regenerative medicine. PMID:25655839

  1. Noncontact imaging of burn depth and extent in a porcine model using spatial frequency domain imaging

    PubMed Central

    Mazhar, Amaan; Saggese, Steve; Pollins, Alonda C.; Cardwell, Nancy L.; Nanney, Lillian; Cuccia, David J.

    2014-01-01

    Abstract. The standard of care for clinical assessment of burn severity and extent lacks a quantitative measurement. In this work, spatial frequency domain imaging (SFDI) was used to measure 48 thermal burns of graded severity (superficial partial, deep partial, and full thickness) in a porcine model. Functional (total hemoglobin and tissue oxygen saturation) and structural parameters (tissue scattering) derived from the SFDI measurements were monitored over 72 h for each burn type and compared to gold standard histological measurements of burn depth. Tissue oxygen saturation (stO2) and total hemoglobin (ctHbT) differentiated superficial partial thickness burns from more severe burn types after 2 and 72 h, respectively (p<0.01), but were unable to differentiate deep partial from full thickness wounds in the first 72 h. Tissue scattering parameters separated superficial burns from all burn types immediately after injury (p<0.01), and separated all three burn types from each other after 24 h (p<0.01). Tissue scattering parameters also showed a strong negative correlation to histological burn depth as measured by vimentin immunostain (r2>0.89). These results show promise for the use of SFDI-derived tissue scattering as a correlation to burn depth and the potential to assess burn depth via a combination of SFDI functional and structural parameters. PMID:25147961

  2. Vascular endothelial growth factor-A gene electrotransfer promotes angiogenesis in a porcine model of cardiac ischemia.

    PubMed

    Bulysheva, A A; Hargrave, B; Burcus, N; Lundberg, C G; Murray, L; Heller, R

    2016-08-01

    This study aimed to assess safety and therapeutic potential of gene electrotransfer (GET) as a method for delivery of plasmid encoding vascular endothelial growth factor A (VEGF-A) to ischemic myocardium in a porcine model. Myocardial ischemia was induced by surgically occluding the left anterior descending coronary artery in swine. GET following plasmid encoding VEGF-A injection was performed at four sites in the ischemic region. Control groups either received injections of the plasmid without electrotransfer or injections of the saline vehicle. Animals were monitored for 7 weeks and the hearts were evaluated for angiogenesis, myocardial infarct size and left ventricular contractility. Arteriograms suggest growth of new arteries as early as 2 weeks after treatment in electrotransfer animals. There is a significant reduction of infarct area and left ventricular contractility is improved in GET-treated group compared with controls. There was no significant difference in mortality of animals treated with GET of plasmid encoding VEGF-A from the control groups. Gene delivery of plasmid encoding VEGF-A to ischemic myocardium in a porcine model can be accomplished safely with potential for myocardial repair and regeneration. PMID:27078083

  3. Effect of porcine circovirus type 2a or 2b on infection kinetics and pathogenicity of two genetically divergent strains of porcine reproductive and respiratory syndrome virus in the conventional pig model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to characterize the infection dynamics and pathogenicity of two heterologous type 2 porcine reproductive and respiratory syndrome virus (PRRSV) isolates in a conventional pig model under the influence of concurrent porcine circovirus (PCV) subtype 2a or 2b infection. ...

  4. A Zebrafish Larval Model to Assess Virulence of Porcine Streptococcus suis Strains.

    PubMed

    Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M; van Baarlen, Peter

    2016-01-01

    Streptococcus suis is an encapsulated Gram-positive bacterium, and the leading cause of sepsis and meningitis in young pigs resulting in considerable economic losses in the porcine industry. It is also considered an emerging zoonotic agent. In the environment, both avirulent and virulent strains occur in pigs, and virulent strains appear to cause disease in both humans and pigs. There is a need for a convenient, reliable and standardized animal model to assess S. suis virulence. A zebrafish (Danio rerio) larvae infection model has several advantages, including transparency of larvae, low cost, ease of use and exemption from ethical legislation up to 6 days post fertilization, but has not been previously established as a model for S. suis. Microinjection of different porcine strains of S. suis in zebrafish larvae resulted in highly reproducible dose- and strain-dependent larval death, strongly correlating with presence of the S. suis capsule and to the original virulence of the strain in pigs. Additionally we compared the virulence of the two-component system mutant of ciaRH, which is attenuated for virulence in both mice and pigs in vivo. Infection of larvae with the ΔciaRH strain resulted in significantly higher survival rate compared to infection with the S10 wild-type strain. Our data demonstrate that zebrafish larvae are a rapid and reliable model to assess the virulence of clinical porcine S. suis isolates. PMID:26999052

  5. A Zebrafish Larval Model to Assess Virulence of Porcine Streptococcus suis Strains

    PubMed Central

    Zaccaria, Edoardo; Cao, Rui; Wells, Jerry M.; van Baarlen, Peter

    2016-01-01

    Streptococcus suis is an encapsulated Gram-positive bacterium, and the leading cause of sepsis and meningitis in young pigs resulting in considerable economic losses in the porcine industry. It is also considered an emerging zoonotic agent. In the environment, both avirulent and virulent strains occur in pigs, and virulent strains appear to cause disease in both humans and pigs. There is a need for a convenient, reliable and standardized animal model to assess S. suis virulence. A zebrafish (Danio rerio) larvae infection model has several advantages, including transparency of larvae, low cost, ease of use and exemption from ethical legislation up to 6 days post fertilization, but has not been previously established as a model for S. suis. Microinjection of different porcine strains of S. suis in zebrafish larvae resulted in highly reproducible dose- and strain-dependent larval death, strongly correlating with presence of the S. suis capsule and to the original virulence of the strain in pigs. Additionally we compared the virulence of the two-component system mutant of ciaRH, which is attenuated for virulence in both mice and pigs in vivo. Infection of larvae with the ΔciaRH strain resulted in significantly higher survival rate compared to infection with the S10 wild-type strain. Our data demonstrate that zebrafish larvae are a rapid and reliable model to assess the virulence of clinical porcine S. suis isolates. PMID:26999052

  6. Cell Sheet Transplantation for Esophageal Stricture Prevention after Endoscopic Submucosal Dissection in a Porcine Model

    PubMed Central

    Pidial, Laetitia; Camilleri, Sophie; Bellucci, Alexandre; Casanova, Amaury; Viel, Thomas; Tavitian, Bertrand; Cellier, Christophe; Clement, Olivier

    2016-01-01

    Background & Aims Extended esophageal endoscopic submucosal dissection (ESD) is highly responsible for esophageal stricture. We conducted a comparative study in a porcine model to evaluate the effectiveness of adipose tissue-derived stromal cell (ADSC) double cell sheet transplantation. Methods Twelve female pigs were treated with 5 cm long hemi-circumferential ESD and randomized in two groups. ADSC group (n = 6) received 4 double cell sheets of allogenic ADSC on a paper support membrane and control group (n = 6) received 4 paper support membranes. ADSC were labelled with PKH-67 fluorophore to allow probe-based confocal laser endomicroscopie (pCLE) monitoring. After 28 days follow-up, animals were sacrificed. At days 3, 14 and 28, endoscopic evaluation with pCLE and esophagography were performed. Results One animal from the control group was excluded (anesthetic complication). Animals from ADSC group showed less frequent alimentary trouble (17% vs 80%; P = 0.08) and higher gain weight on day 28. pCLE demonstrated a compatible cell signal in 4 animals of the ADSC group at day 3. In ADSC group, endoscopy showed that 1 out of 6(17%) animals developed a severe esophageal stricture comparatively to 100% (5/5) in the control group; P = 0.015. Esophagography demonstrated a decreased degree of stricture in the ADSC group on day 14 (44% vs 81%; P = 0.017) and day 28 (46% vs 90%; P = 0.035). Histological analysis showed a decreased fibrosis development in the ADSC group, in terms of surface (9.7 vs 26.1 mm²; P = 0.017) and maximal depth (1.6 vs 3.2 mm; P = 0.052). Conclusion In this model, transplantation of allogenic ADSC organized in double cell sheets after extended esophegeal ESD is strongly associated with a lower esophageal stricture’s rate. PMID:26930409

  7. Porcine gonadogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Five images submitted for teaching purposes related to porcine gonadogenesis (2), porcine fetal testicular development (2), and porcine fetal ovarian development. Key words include: Egg cell nests, Embryo, GATA4, Genital ridge, Gonad, Leydig cell, Mesonephros, MIS, Ovary, P450c17, Porcine, Sertoli ...

  8. Extrahepatic islet transplantation with microporous polymer scaffolds in syngeneic mouse and allogeneic porcine models

    PubMed Central

    Gibly, Romie F.; Zhang, Xiaomin; Graham, Melanie L.; Hering, Bernhard J.; Kaufman, Dixon B.; Lowe, William L.; Shea, Lonnie D.

    2011-01-01

    Intraportal transplantation of islets has successfully treated select patients with type 1 diabetes. However, intravascular infusion and the intrahepatic site contribute to significant early and late islet loss, yet a clinical alternative has remained elusive. We investigated non-encapsulating, porous, biodegradable polymer scaffolds as a vehicle for islet transplantation into extrahepatic sites, using syngeneic mouse and allogeneic porcine models. Scaffold architecture was modified to enhance cell infiltration leading to re-vascularization of the islets with minimal inflammatory response. In the diabetic mouse model, 125 islets seeded on scaffolds implanted into the epididymal fat pad restored normoglycemia within an average of 1.95 days and transplantation of only 75 islets required 12.1 days. Increasing the pore size to increase islet-islet interactions did not significantly impact islet function. The porcine model was used to investigate early islet engraftment. Increasing the islet seeding density led to a greater mass of engrafted islets, though the efficiency of islet survival decreased. Transplantation into the porcine omentum provided greater islet engraftment than the gastric submucosa. These results demonstrate scaffolds support murine islet transplantation with high efficiency, and feasibility studies in large animals support continued pre-clinical studies with scaffolds as a platform to control the transplant microenvironment. PMID:21959005

  9. A novel coculture model of porcine central neuroretina explants and retinal pigment epithelium cells

    PubMed Central

    Di Lauro, Salvatore; Rodriguez-Crespo, David; Gayoso, Manuel J.; Garcia-Gutierrez, Maria T.; Pastor, J. Carlos; Srivastava, Girish K.

    2016-01-01

    Purpose To develop and standardize a novel organ culture model using porcine central neuroretina explants and RPE cells separated by a cell culture membrane. Methods RPE cells were isolated from porcine eyes, expanded, and seeded on the bottom of cell culture inserts. Neuroretina explants were obtained from the area centralis and cultured alone (controls) on cell culture membranes or supplemented with RPE cells in the same wells but physically separated by the culture membrane. Finally, cellular and tissue specimens were processed for phase contrast, cyto-/histological, and immunochemical evaluation. Neuroretina thickness was also determined. Results Compared to the neuroretinas cultured alone, the neuroretinas cocultured with RPE cells maintained better tissue structure and cellular organization, displayed better preservation of photoreceptors containing rhodopsin, lower levels of glial fibrillary acidic protein immunoexpression, and preservation of cellular retinaldehyde binding protein both markers of reactive gliosis. Neuroretina thickness was significantly greater in the cocultures. Conclusions A coculture model of central porcine neuroretina and RPE cells was successfully developed and standardized. This model mimics a subretinal space and will be useful in studying interactions between the RPE and the neuroretina and to preclinically test potential therapies. PMID:27081295

  10. Short Duration Combined Mild Hypothermia Improves Resuscitation Outcomes in a Porcine Model of Prolonged Cardiac Arrest

    PubMed Central

    Yu, Tao; Yang, Zhengfei; Li, Heng; Ding, Youde; Huang, Zitong; Li, Yongqin

    2015-01-01

    Objective. In this study, our aim was to investigate the effects of combined hypothermia with short duration maintenance on the resuscitation outcomes in a porcine model of ventricular fibrillation (VF). Methods. Fourteen porcine models were electrically induced with VF and untreated for 11 mins. All animals were successfully resuscitated manually and then randomized into two groups: combined mild hypothermia (CH group) and normothermia group (NT group). A combined hypothermia of ice cold saline infusion and surface cooling was implemented in the animals of the CH group and maintained for 4 hours. The survival outcomes and neurological function were evaluated every 24 hours until a maximum of 96 hours. Neuron apoptosis in hippocampus was analyzed. Results. There were no significant differences in baseline physiologies and primary resuscitation outcomes between both groups. Obvious improvements of cardiac output were observed in the CH group at 120, 180, and 240 mins following resuscitation. The animals demonstrated better survival at 96 hours in the CH group when compared to the NT group. In comparison with the NT group, favorable neurological functions were observed in the CH group. Conclusion. Short duration combined cooling initiated after resuscitation improves survival and neurological outcomes in a porcine model of prolonged VF. PMID:26558261

  11. Shear mechanical properties of the porcine pancreas: experiment and analytical modelling.

    PubMed

    Nicolle, S; Noguer, L; Palierne, J-F

    2013-10-01

    We provide the first account of the shear mechanical properties of porcine pancreas using a rheometer both in linear oscillatory tests and in constant strain-rate tests reaching the non-linear sub-failure regime. Our results show that pancreas has a low and weakly frequency-dependent dynamic modulus and experiences a noticeable strain-hardening beyond 20% strain. In both linear and non-linear regime, the viscoelastic behaviour of porcine pancreas follows a four-parameter bi-power model that has been validated on kidney, liver and spleen. Among the four solid organs of the abdomen, pancreas proves to be the most compliant and the most viscous one. PMID:23820244

  12. Structural investigation of porcine stomach mucin by X-ray fiber diffraction and homology modeling

    SciTech Connect

    Veluraja, K.; Vennila, K.N.; Umamakeshvari, K.; Jasmine, A.; Velmurugan, D.

    2011-03-25

    Research highlights: {yields} Techniques to get oriented mucin fibre. {yields} X-ray fibre diffraction pattern for mucin. {yields} Molecular modeling of mucin based on X-ray fibre diffraction pattern. -- Abstract: The basic understanding of the three dimensional structure of mucin is essential to understand its physiological function. Technology has been developed to achieve orientated porcine stomach mucin molecules. X-ray fiber diffraction of partially orientated porcine stomach mucin molecules show d-spacing signals at 2.99, 4.06, 4.22, 4.7, 5.37 and 6.5 A. The high intense d-spacing signal at 4.22 A is attributed to the antiparallel {beta}-sheet structure identified in the fraction of the homology modeled mucin molecule (amino acid residues 800-980) using Nidogen-Laminin complex structure as a template. The X-ray fiber diffraction signal at 6.5 A reveals partial organization of oligosaccharides in porcine stomach mucin. This partial structure of mucin will be helpful in establishing a three dimensional structure for the whole mucin molecule.

  13. ENDOSCOPIC HIGH-INTENSITY FOCUSED US: TECHNICAL ASPECTS AND STUDIES IN AN IN VIVO PORCINE MODEL

    PubMed Central

    Li, Tong; Khokhlova, Tatiana; Wang, Yak-Nam; Maloney, Ezekiel; D'Andrea, Samantha; Starr, Frank; Farr, Navid; Morrison, Kyle; Keilman, George; Hwang, Joo Ha

    2015-01-01

    Background High-intensity focused ultrasound (HIFU) is becoming more widely used for non-invasive and minimally invasive ablation of benign and malignant tumors. Recent studies suggest that HIFU can also enhance targeted drug delivery and stimulate an anti-tumor immune response in many tumors. However, targeting of pancreatic and liver tumors using an extracorporeal source is challenging due to the lack of an adequate acoustic window. The development of an endoscopic ultrasound (EUS)-guided HIFU transducer has many potential benefits including improved targeting, decreased energy requirements and decreased potential for injury to intervening structures. Objective To design, develop and test an EUS-guided HIFU transducer for endoscopic applications. Design A pre-clinical, pilot characterization and feasibility study. Setting Academic research center. Patients Studies were performed in an in vivo porcine model. Intervention Thermal ablation of in vivo porcine pancreas and liver was performed with EUS guided focused ultrasound through the gastric tract. Results The transducer successfully created lesions in gel phantoms and ex vivo bovine livers. In vivo studies demonstrated that targeting and creating lesions in the porcine pancreas and liver are feasible. Limitations This is a pre-clinical, single-center feasibility study with a limited number of subjects. Conclusion An EUS-guided HIFU transducer was successfully designed and developed with dimensions that are appropriate for endoscopic use. Feasibility of performing EUS-guided HIFU ablation in vivo has been demonstrated in an in vivo porcine model. Further development of this technology will allow endoscopists to perform precise therapeutic ablation of peri-lumenal lesions without breaching the wall of the gastric tract. PMID:25759124

  14. Small-Incision Laparoscopy-Assisted Surgery Under Abdominal Cavity Irrigation in a Porcine Model

    PubMed Central

    Ishii, Takuro; Aoe, Tomohiko; Yu, Wen-Wei; Ebihara, Yuma; Kawahira, Hiroshi; Isono, Shiro; Naya, Yukio

    2016-01-01

    Abstract Background: Laparoscopic and robot-assisted surgeries are performed under carbon dioxide insufflation. Switching from gas to an isotonic irrigant introduces several benefits and avoids some adverse effects of gas insufflation. We developed an irrigating device and apparatus designed for single-incision laparoscopic surgery and tested its advantages and drawbacks during surgery in a porcine model. Materials and Methods: Six pigs underwent surgical procedures under general anesthesia. A 30-cm extracorporeal cistern was placed over a 5–6-cm abdominal incision. The abdomen was irrigated with warm saline that was drained via a suction tube placed near the surgical field and continuously recirculated through a closed circuit equipped with a hemodialyzer as a filter. Irrigant samples from two pigs were cultured to check for bacterial and fungal contamination. Body weight was measured before and after surgery in four pigs that had not received treatments affecting hemodynamics or causing diuresis. Results: One-way flow of irrigant ensured laparoscopic vision by rinsing blood from the surgical field. Through a retroperitoneal approach, cystoprostatectomy was successfully performed in three pigs, nephrectomy in two, renal excision in two, and partial nephrectomy in one, under simultaneous ultrasonographic monitoring. Through a transperitoneal approach, liver excision and hemostasis with a bipolar sealing device were performed in three pigs, and bladder pedicle excision was performed in one pig. Bacterial and fungal contamination of the irrigant was observed on the draining side of the circuit, but the filter captured the contaminants. Body weight increased by a median of 2.1% (range, 1.2–4.4%) of initial weight after 3–5 hours of irrigation. Conclusions: Surgery under irrigation is feasible and practical when performed via a cistern through a small abdominal incision. This method is advantageous, especially in the enabling of continuous and free

  15. Long-term survival and integration of porcine expanded neural precursor cell grafts in a rat model of Parkinson's disease.

    PubMed

    Harrower, T P; Tyers, P; Hooks, Y; Barker, R A

    2006-01-01

    Porcine fetal neural tissue has been considered as an alternative source to human allografts for transplantation in neurodegenerative disorders by virtue of the fact that it can overcome the ethical and practical difficulties using human fetal neural tissue. However, primary porcine neural xenografts are rejected while porcine expanded neural precursor neural cells (PNPCs) seem to be less immunogenic and thus survive better [Armstrong, R.J., Harrower, T.P., Hurelbrink, C.B., McLaughin, M., Ratcliffe, E.L., Tyers, P., Richards, A., Dunnett, S.B., Rosser, A.E., Barker, R.A., 2001a. Porcine neural xenografts in the immunocompetent rat: immune response following grafting of expanded neural precursor cells. Neuroscience 106, 201-216]. In this study, we extended these observations to investigate the long-term survival of such transplants in immunosuppressed rats. Unilateral 6 OHDA lesioned rats received grafts into the dopamine denervated striatum of either primary porcine fetal neural tissue dissected from the E26 cortex or cortically derived neural stem cells which had been derived from the same source but expanded in vitro for 21 days. All cortically derived neural stem cell grafts survived up to 5 months in contrast to the poor survival of primary porcine xenografts. Histological analysis demonstrated good graft integration with fibers extending into the surrounding host tissue including white matter with synapse formation, and in addition there was evidence of host vascularization and myelinated fibers within the graft area. This study has therefore shown for the first time the reliable long-term survival of grafts derived from porcine expanded neural precursors in a rat model of PD, with maturation and integration into the host brain. This demonstrates that such xenografted cells may be able to recreate the damaged circuitry in PD although strategies for dopaminergic differentiation of the porcine neural precursor cell remain to be refined. PMID:16246328

  16. Creating a model of diseased artery damage and failure from healthy porcine aorta.

    PubMed

    Noble, Christopher; Smulders, Nicole; Green, Nicola H; Lewis, Roger; Carré, Matt J; Franklin, Steve E; MacNeil, Sheila; Taylor, Zeike A

    2016-07-01

    Large quantities of diseased tissue are required in the research and development of new generations of medical devices, for example for use in physical testing. However, these are difficult to obtain. In contrast, porcine arteries are readily available as they are regarded as waste. Therefore, reliable means of creating from porcine tissue physical models of diseased human tissue that emulate well the associated mechanical changes would be valuable. To this end, we studied the effect on mechanical response of treating porcine thoracic aorta with collagenase, elastase and glutaraldehyde. The alterations in mechanical and failure properties were assessed via uniaxial tension testing. A constitutive model composed of the Gasser-Ogden-Holzapfel model, for elastic response, and a continuum damage model, for the failure, was also employed to provide a further basis for comparison (Calvo and Peña, 2006; Gasser et al., 2006). For the concentrations used here it was found that: collagenase treated samples showed decreased fracture stress in the axial direction only; elastase treated samples showed increased fracture stress in the circumferential direction only; and glutaraldehyde samples showed no change in either direction. With respect to the proposed constitutive model, both collagenase and elastase had a strong effect on the fibre-related terms. The model more closely captured the tissue response in the circumferential direction, due to the smoother and sharper transition from damage initiation to complete failure in this direction. Finally, comparison of the results with those of tensile tests on diseased tissues suggests that these treatments indeed provide a basis for creation of physical models of diseased arteries. PMID:26945437

  17. A model of security monitoring

    NASA Technical Reports Server (NTRS)

    Bishop, Matt

    1990-01-01

    A model of security monitoring is presented that distinguishes between two types of logging and auditing. Implications for the design and use of security monitoring mechanisms are drawn from this model. The usefulness of the model is then demonstrated by analyzing several different monitoring mechanisms.

  18. A model of security monitoring

    NASA Technical Reports Server (NTRS)

    Bishop, Matt

    1989-01-01

    A model of security monitoring is presented that distinguishes between two types of logging and auditing. Implications for the design and use of security monitoring mechanisms are drawn from this model. The usefulness of the model is then demonstrated by analyzing several different monitoring mechanisms.

  19. Novel technique for full-thickness resection of gastric malignancy: feasibility of nonexposed endoscopic wall-inversion surgery (news) in porcine models.

    PubMed

    Mitsui, Takashi; Goto, Osamu; Shimizu, Nobuyuki; Hatao, Fumihiko; Wada, Ikuo; Niimi, Keiko; Asada-Hirayama, Itsuko; Fujishiro, Mitsuihiro; Koike, Kazuhiko; Seto, Yasuyuki

    2013-12-01

    Full-thickness resection for gastric malignancy carries a risk of peritoneal dissemination due to opening of the gastric lumen. We evaluated the feasibility and safety a novel method of full-thickness resection without transmural communication, called nonexposed endoscopic wall-inversion surgery in ex vivo and in vivo porcine models. Six explanted porcine stomachs and 6 live pigs were used for this study. After marking and submucosal injection around 3 cm simulated lesions, the seromuscular layer was laparoscopically cut and sutured with the lesion inverted to the inside. Consecutively, a mucosubmucosal incision was made endoscopically. Three pigs used for the survival study were monitored for 7 days. All 12 lesions were successfully resected en bloc without perforation. The 3 pigs survived for 1 week without adverse events, and necropsy revealed neither leakage nor abscess formation related to the operation. We demonstrated nonexposed endoscopic wall-inversion surgery to be technically feasible and safe in both ex vivo and in vivo porcine studies. PMID:24300935

  20. Material Properties and Constitutive Modeling of Infant Porcine Cerebellum Tissue in Tension at High Strain Rate

    PubMed Central

    Li, Kui; Zhao, Hui; Liu, Wenjun; Yin, Zhiyong

    2015-01-01

    Background The mechanical characterization of infant porcine cerebellum tissue in tension at high strain rate is crucial for modeling traumatic cerebellum injury, which is in turn helpful for understanding the biomechanics of such injuries suffered in traffic accidents. Material and Method In this study, the infant porcine cerebellum tissue was given three loading velocities, ie, 2s-1, 20s-1 and 100s-1 with up to 30% strain to investigate the tensile properties. At least six tensile tests for each strain rate were validly performed. Fung, Gent, Ogden and exponential models were applied to fit the constitutive equations, so as to obtain material parameters from the experimental data. Results The Lagrange stress of infant porcine cerebellum tissue in tension appeared to be no more than 3000Pa at each loading velocity. More specifically, the Lagrange stress at 30% strain was (393.7±84.4)Pa, (928.3±56.3)Pa and (2582.4±282.2)Pa at strain rates of 2s-1, 20s-1 and 100s-1, respectively. Fung (0.833≤R2≤0.924), Gent (0.797≤R2≤0.875), Ogden (0.859≤R2≤0.944) and exponential (0.930≤R2≤0.972) models provided excellent fitting to experimental data up to 30% strain. Conclusions The infant cerebellum tissue shows a stiffer response with increase of the loading speed, indicating a strong strain-rate sensitivity. This study will enrich the knowledge on the material properties of infant brain tissue, which may augment the biofidelity of finite element model of human pediatric cerebellum. PMID:25830545

  1. Porcine models of digestive disease: the future of large animal translational research

    PubMed Central

    Gonzalez, Liara M.; Moeser, Adam J.; Blikslager, Anthony T.

    2015-01-01

    There is increasing interest in non-rodent translational models for the study of human disease. The pig, in particular, serves as a useful animal model for the study of pathophysiological conditions relevant to the human intestine. This review assesses currently used porcine models of gastrointestinal physiology and disease and provides a rationale for the use of these models for future translational studies. The pig has proven its utility for the study of fundamental disease conditions such as ischemia/ reperfusion injury, stress-induced intestinal dysfunction, and short bowel syndrome. Pigs have also shown great promise for the study of intestinal barrier function, surgical tissue manipulation and intervention, as well as biomaterial implantation and tissue transplantation. Advantages of pig models highlighted by these studies include the physiological similarity to human intestine as well as to mechanisms of human disease. Emerging future directions for porcine models of human disease include the fields of transgenics and stem cell biology, with exciting implications for regenerative medicine. PMID:25655839

  2. A Porcine Anterior Segment Perfusion and Transduction Model With Direct Visualization of the Trabecular Meshwork

    PubMed Central

    Loewen, Ralitsa T.; Roy, Pritha; Park, Daniel B.; Jensen, Adrianna; Scott, Gordon; Cohen-Karni, Devora; Fautsch, Michael P.; Schuman, Joel S.; Loewen, Nils A.

    2016-01-01

    Purpose To establish a consistent and affordable, high quality porcine anterior segment perfusion and transduction model that allows direct visualization of the trabecular meshwork. Methods Porcine anterior segments were cultured within 2 hours of death by removing lens and uvea and securing in a specially designed petri dish with a thin bottom to allow direct visualization of the trabecular meshwork with minimal distortion. Twenty-two control eyes (CO) with a constant flow rate were compared to eight gravity perfused eyes (COgr, 15 mm Hg). We established gene delivery to the TM using eGFP expressing feline immunodeficiency virus (FIV) vector GINSIN at 108 transducing units (TU) per eye (GINSIN_8, n = 8) and 107 TU (GINSIN_7, n = 8). Expression was assessed for 14 days before histology was obtained. Results Pig eyes were a reliable source for consistent and high quality anterior segment cultures with a low failure rate of 12%. Control eyes had an intraocular pressure (IOP) of 15.8 ± 1.9 mm Hg at fixed pump perfusion with 3 μL/min compared to gravity perfused COgr with imputed 3.7 ± 1.6 μL/min. Vector GINSIN_8 eyes experienced a transient posttransduction IOP increase of 44% that resolved at 48 hours; this was not observed in GINSIN_7 eyes. Expression was higher in GINSIN_8 than in GINSIN_7 eyes. Trabecular meshwork architecture was well preserved. Conclusions Compared with previously used human donor eyes, this inexpensive porcine anterior segment perfusion model is of sufficient, repeatable high quality to develop strategies of TM bioengineering. Trabecular meshwork could be observed directly. Despite significant anatomic differences, effects of transduction replicate the main aspects of previously explored human, feline and rodent models. PMID:27002293

  3. Robot-Assisted Pterygium Surgery: Feasibility Study in a Nonliving Porcine Model

    PubMed Central

    Bourcier, Tristan; Nardin, Mathieu; Sauer, Arnaud; Gaucher, David; Speeg, Claude; Mutter, Didier; Marescaux, Jacques; Liverneaux, Philippe

    2015-01-01

    Purpose This study aims to investigate the feasibility of pterygium surgery using the DaVinci Si HD robotic surgical system, and to describe a porcine model for pterygium surgery and evaluate its usefulness. Methods The pterygium models were constructed using enucleated pig eyes and cold cuts. Robotically-assisted pterygium surgeries in nonliving biological pterygium models were performed using the DaVinci Si HD robotic surgical system. Twelve models were prepared, and 12 pterygium excision and conjunctival autografts were performed. Results The DaVinci system provided the necessary dexterity to perform delicate ocular surface surgery and robotic tools were safe for the tissues. The mean duration of the surgical procedures was 36 minutes. There were no intraoperative complications and no unexpected events. Conclusions Robotic-assisted pterygium surgery is technically feasible for porcine eyes using the DaVinci Si HD robotic surgical system. The pterygium model that we describe could be of interest for surgical training. Translational Relevance Little research has been done in robotic microsurgery. Animal experimentation will allow the advantages of robotic-assisted microsurgery to be identified, while underlining the improvements and innovations necessary for clinical use. PMID:25722953

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Constitutive Modeling of Porcine Liver in Indentation Using 3D Ultrasound Imaging

    PubMed Central

    Jordan, P.; Socrate, S.; Zickler, T.E.; Howe, R.D.

    2009-01-01

    In this work we present an inverse finite-element modeling framework for constitutive modeling and parameter estimation of soft tissues using full-field volumetric deformation data obtained from 3D ultrasound. The finite-element model is coupled to full-field visual measurements by regularization springs attached at nodal locations. The free ends of the springs are displaced according to the locally estimated tissue motion and the normalized potential energy stored in all springs serves as a measure of model-experiment agreement for material parameter optimization. We demonstrate good accuracy of estimated parameters and consistent convergence properties on synthetically generated data. We present constitutive model selection and parameter estimation for perfused porcine liver in indentation and demonstrate that a quasilinear viscoelastic model with shear modulus relaxation offers good model-experiment agreement in terms of indenter displacement (0.19 mm RMS error) and tissue displacement field (0.97 mm RMS error). PMID:19627823

  6. Mesenchymal stem cells preserve neonatal right ventricular function in a porcine model of pressure overload.

    PubMed

    Wehman, Brody; Sharma, Sudhish; Pietris, Nicholas; Mishra, Rachana; Siddiqui, Osama T; Bigham, Grace; Li, Tieluo; Aiello, Emily; Murthi, Sarah; Pittenger, Mark; Griffith, Bartley; Kaushal, Sunjay

    2016-06-01

    Limited therapies exist for patients with congenital heart disease (CHD) who develop right ventricular (RV) dysfunction. Bone marrow-derived mesenchymal stem cells (MSCs) have not been evaluated in a preclinical model of pressure overload, which simulates the pathophysiology relevant to many forms of CHD. A neonatal swine model of RV pressure overload was utilized to test the hypothesis that MSCs preserve RV function and attenuate ventricular remodeling. Immunosuppressed Yorkshire swine underwent pulmonary artery banding to induce RV dysfunction. After 30 min, human MSCs (1 million cells, n = 5) or placebo (n = 5) were injected intramyocardially into the RV free wall. Serial transthoracic echocardiography monitored RV functional indices including 2D myocardial strain analysis. Four weeks postinjection, the MSC-treated myocardium had a smaller increase in RV end-diastolic area, end-systolic area, and tricuspid vena contracta width (P < 0.01), increased RV fractional area of change, and improved myocardial strain mechanics relative to placebo (P < 0.01). The MSC-treated myocardium demonstrated enhanced neovessel formation (P < 0.0001), superior recruitment of endogenous c-kit+ cardiac stem cells to the RV (P < 0.0001) and increased proliferation of cardiomyocytes (P = 0.0009) and endothelial cells (P < 0.0001). Hypertrophic changes in the RV were more pronounced in the placebo group, as evidenced by greater wall thickness by echocardiography (P = 0.008), increased cardiomyocyte cross-sectional area (P = 0.001), and increased expression of hypertrophy-related genes, including brain natriuretic peptide, β-myosin heavy chain and myosin light chain. Additionally, MSC-treated myocardium demonstrated increased expression of the antihypertrophy secreted factor, growth differentiation factor 15 (GDF15), and its downstream effector, SMAD 2/3, in cultured neonatal rat cardiomyocytes and in the porcine RV myocardium. This is the first report of the use of MSCs as a therapeutic

  7. In vivo porcine left atrial wall stress: Computational model.

    PubMed

    Di Martino, Elena S; Bellini, Chiara; Schwartzman, David S

    2011-10-13

    Most computational models of the heart have so far concentrated on the study of the left ventricle, mainly using simplified geometries. The same approach cannot be adopted to model the left atrium, whose irregular shape does not allow morphological simplifications. In addition, the deformation of the left atrium during the cardiac cycle strongly depends on the interaction with its surrounding structures. We present a procedure to generate a comprehensive computational model of the left atrium, including physiological loads (blood pressure), boundary conditions (pericardium, pulmonary veins and mitral valve annulus movement) and mechanical properties based on planar biaxial experiments. The model was able to accurately reproduce the in vivo dynamics of the left atrium during the passive portion of the cardiac cycle. A shift in time between the peak pressure and the maximum displacement of the mitral valve annulus allows the appendage to inflate and bend towards the ventricle before the pulling effect associated with the ventricle contraction takes place. The ventricular systole creates room for further expansion of the appendage, which gets in close contact with the pericardium. The temporal evolution of the volume in the atrial cavity as predicted by the finite element simulation matches the volume changes obtained from CT scans. The stress field computed at each time point shows remarkable spatial heterogeneity. In particular, high stress concentration occurs along the appendage rim and in the region surrounding the pulmonary veins. PMID:21907340

  8. ULTRASOUND-ENHANCED rt-PA THROMBOLYSIS IN AN EX VIVO PORCINE CAROTID ARTERY MODEL

    PubMed Central

    Hitchcock, Kathryn E.; Ivancevich, Nikolas M.; Haworth, Kevin J.; Caudell Stamper, Danielle N.; Vela, Deborah C.; Sutton, Jonathan T.; Pyne-Geithman, Gail J.; Holland, Christy K.

    2014-01-01

    Ultrasound is known to enhance recombinant tissue plasminogen activator (rt-PA) thrombolysis. In this study, occlusive porcine whole blood clots were placed in flowing plasma within living porcine carotid arteries. Ultrasonically induced stable cavitation was investigated as an adjuvant to rt-PA thrombolysis. Aged, retracted clots were exposed to plasma alone, plasma containing rt-PA (7.1 ± 3.8 μg/mL) or plasma with rt-PA and Definity® ultrasound contrast agent (0.79 ± 0.47 μL/mL) with and without 120-kHz continuous wave ultrasound at a peak-to-peak pressure amplitude of 0.44 MPa. An insonation scheme was formulated to promote and maximize stable cavitation activity by incorporating ultrasound quiescent periods that allowed for the inflow of Definity®-rich plasma. Cavitation was measured with a passive acoustic detector throughout thrombolytic treatment. Thrombolytic efficacy was measured by comparing clot mass before and after treatment. Average mass loss for clots exposed to rt-PA and Definity® without ultrasound (n = 7) was 34%, and with ultrasound (n = 6) was 83%, which constituted a significant difference (p < 0.0001). Without Definity® there was no thrombolytic enhancement by ultrasound exposure alone at this pressure amplitude (n = 5, p < 0.0001). In the low-oxygen environment of the ischemic artery, significant loss of endothelium occurred but no correlation was observed between arterial tissue damage and treatment type. Acoustic stable cavitation nucleated by an infusion of Definity® enhances rt-PA thrombolysis without apparent treatment-related damage in this ex vivo porcine carotid artery model. PMID:21723448

  9. Porcine aortic organ culture: a model to study the cellular response to vascular injury.

    PubMed

    Gotlieb, A I; Boden, P

    1984-07-01

    Organ cultures of porcine thoracic aorta were studied to define the characteristics of this system as a model to study the reaction of endothelial cells (ECs) and the underlying smooth muscle cells (SMCs) to injury. Both nonwounded and wounded cultures, the latter having had part of the endothelial surface gently denuded with a scalpel blade, were studied over a 7 d period by scanning and transmission electron microscopy. The results showed that the nonwounded ECs underwent a shape change from elongated to polygonal within 24 h in culture. In both nonwounded and wounded explants there was cell proliferation beneath the nondenuded endothelium so that by 7 d several layers of cells were present showing features of the secretory type of SMCs. This proliferation, however, did not occur if the endothelium was totally removed from the aorta. There was also evidence of gaps between the surface ECs, and by 7 d lamellipodia of cells beneath the surface were present in these gaps. Occasionally, elongated cells were seen to be present on the surface of the endothelium. In the wounded organ culture, cell migration and proliferation occurred extending from the wound edge and producing a covering of cells on the denuded area. There were also multilayered cells beneath the surface similar to the nonwounded area. Occasional foam cells were seen in the depth of the multilayered proliferating cells. The results indicate that organ culture of porcine thoracic aorta is a good model to study the reaction of ECs and underlying SMCs to injury. PMID:6469272

  10. Restenosis and the proportional neointimal response to coronary artery injury: results in a porcine model.

    PubMed

    Schwartz, R S; Huber, K C; Murphy, J G; Edwards, W D; Camrud, A R; Vlietstra, R E; Holmes, D R

    1992-02-01

    Restenosis is a reparative response to arterial injury occurring with percutaneous coronary revascularization. However, the quantitative characteristics of the relation between vessel injury and the magnitude of restenotic response remain unknown. This study was thus performed to determine the relation between severity of vessel wall injury and the thickness of resulting neointimal proliferation in a porcine model of coronary restenosis. Twenty-six porcine coronary artery segments in 24 pigs were subjected to deep arterial injury with use of overexpanded, percutaneously delivered tantalum wire coils. The vessels were studied microscopically 4 weeks after coil implantation to measure the relation between the extent of injury and the resulting neointimal thickness. For each wire site, a histopathologic score proportional to injury depth and the neointimal thicknesses at that site were determined. Mean injury scores were compared with both mean neointimal thickness and planimetry-derived area percent lumen stenosis. The severity of vessel injury strongly correlated with neointimal thickness and percent diameter stenosis (p less than 0.001). Neointimal proliferation resulting from a given wire was related to injury severity in adjacent wires, suggesting an interaction among effects at injured sites. If the results in this model apply to human coronary arteries, restenosis may depend on the degree of vessel injury sustained during angioplasty. PMID:1732351

  11. Porcine retinal cell line VIDO R1 and Chlamydia suis to modelize ocular chlamydiosis.

    PubMed

    Käser, Tobias; Cnudde, Thomas; Hamonic, Glenn; Rieder, Meghanne; Pasternak, J Alex; Lai, Ken; Tikoo, Suresh K; Wilson, Heather L; Meurens, François

    2015-08-15

    Human ocular Chlamydia trachomatis infections can lead to trachoma, the major cause of infectious blindness worldwide. Trachoma control strategies are very helpful but logistically challenging, and a trachoma vaccine is needed but not available. Pigs are a valuable large animal model for various immunological questions and could facilitate the study of human ocular chlamydial infections. In addition, a recent study identified the zoonotic potential of Chlamydia suis, the natural pathogen of pigs. In terms of the One Health Initiative, understanding the host-pathogen-interactions and finding a vaccine for porcine chlamydia infections would also benefit human health. Thus, we infected the porcine retinal cell line VIDO R1 with C. suis and analyzed the chlamydial life cycle and the innate immune response of the infected cells. Our results indicate that C. suis completes its life cycle in VIDO R1 cells within 48 h, comparable to C. trachomatis in humans. C. suis infection of VIDO R1 cells led to increased levels of various innate immune mediators like pathogen recognition receptors, cytokines and chemokines including IL6, TNFα, and MMP9, also most relevant in human C. trachomatis infections. These results illustrate the first steps in the host-pathogen-interactions of ocular C. suis infections in pigs and show their similarity to C. trachomatis infections in humans, justifying further testing of pigs as an animal model for human trachoma. PMID:26103808

  12. A novel device to create consistent deep dermal burns in a porcine model

    PubMed Central

    Menon, Seema; Chan, Queenie; Bertinetti, Monique; Harvey, John G; Hei, Erik R La; Holland, Andrew JA

    2016-01-01

    We conducted this study to evaluate a novel device to create a consistent and reproducible deep partial thickness burn in a porcine model. A thermostatically controlled, heated aluminium disc device was fashioned by the Biomedical Department of our institution. Contact burns were made on the flank of two Great White pigs by applying the device heated to 92°C at intervals of 5, 10, 15 and 20 seconds to four separate test areas area of skin. Biopsies for histological analysis of burn depth were taken on day 0 at 10 minutes post burn and on day 8. Biopsies taken at day 0 revealed superficial to mid-dermal burns, with minimal dermal edema and necrosis. Those from day 8 showed mid to deep dermal edema and necrosis in all four test areas following a 20 second contact duration burn. The new contact burn device was able to create a consistent deep dermal burn after 20 seconds of contact. We anticipate that this new device could be used to investigate the development of hypertrophic scarring in a porcine model. PMID:27335694

  13. Laparoscopic colonic anastomosis using a degradable stent in a porcine model

    PubMed Central

    Ma, Liang; Cai, Xiu-Jun; Wang, Hai-Hong; Yu, Yan-Lan; Huang, Di-Yu; Ge, Guang-Ju; Hu, Hai-Yi; Yu, Shi-Cheng

    2016-01-01

    AIM: To explore the feasibility and safety of laparoscopic colonic anastomosis using a degradable stent in a porcine model. METHODS: Twenty Bama mini-pigs were randomly assigned to a stent group (n = 10) and control group (hand-sewn anastomosis, n = 10). The anastomotic completion and operation times were recorded, along with histological examination, postoperative general condition, complications, mortality, bursting pressure, and the average anastomotic circumference (AC). RESULTS: All pigs survived postoperatively except for one in the stent group that died from ileus at 11 wk postoperatively. The operation and anastomotic completion times of the stent group were significantly shorter than those of the control group (P = 0.004 and P = 0.001, respectively). There were no significant differences in bursting pressure between the groups (P = 0.751). No obvious difference was found between the AC and normal circumference in the stent group, but AC was significantly less than normal circumference in the control group (P = 0.047, P < 0.05). No intestinal leakage and luminal stenosis occurred in the stent group. Histological examination revealed that the stent group presented with lower general inflammation and better healing. CONCLUSION: Laparoscopic colonic anastomosis with a degradable stent is a simple, rapid, and safe procedure in this porcine model. PMID:27217702

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

    PubMed Central

    Weuster, Matthias; Mommsen, Philipp; Pfeifer, Roman; Mohr, Juliane; Ruchholtz, Steffen; Flohé, Sascha; Fröhlich, Matthias; Keibl, Claudia; Seekamp, Andreas; van Griensven, Martijn; 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

  15. Sinus Hypoplasia Precedes Sinus Infection in a Porcine Model of Cystic Fibrosis

    PubMed Central

    Chang, Eugene H; Pezzulo, Alejandro A; Meyerholz, David K; Potash, Andrea E; Wallen, Tanner J; Reznikov, Leah R; Sieren, Jessica C; Karp, Philip H; Ernst, Sarah; Moninger, Thomas O; Gansemer, Nicholas D; McCray, Paul B; Stoltz, David A; Welsh, Michael J; Zabner, Joseph

    2012-01-01

    Objectives/Hypothesis Chronic sinusitis is nearly universal in humans with cystic fibrosis (CF) and is accompanied by sinus hypoplasia (small sinuses). However, whether impaired sinus development is a primary feature of loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or a secondary consequence of chronic infection remains unknown. Our objective was to study the early pathogenesis of sinus disease in CF. Study Design Animal/basic science research. Methods Sinus development was studied in a porcine CF model. Results Porcine sinus epithelia expressed CFTR and exhibited transepithelial anion transport. Disruption of the CFTR gene eliminated both. Sinuses of newborn CF pigs were not infected and showed no evidence of inflammation, yet were hypoplastic at birth. Older CF pigs spontaneously developed sinus disease similar to that seen in humans with CF. Conclusions These results define a role for CFTR in sinus development and suggest the potential of the CF pig as a genetic model of CF-sinus disease in which to test therapeutic strategies to minimize sinus-related CF morbidity. PMID:22711071

  16. Ventricular Arrhythmias and Mortality Associated with Isoflurane and Sevoflurane in a Porcine Model of Myocardial Infarction

    PubMed Central

    Regueiro-Purriños, Marta; Fernández-Vázquez, Felipe; de Prado, Armando Perez; Altónaga, Jose R; Cuellas-Ramón, Carlos; Ajenjo-Silverio, Jose M; Orden, Asuncion; Gonzalo-Orden, Jose M

    2011-01-01

    Ischemia of the myocardium can lead to reversible or irreversible injury depending on the severity and duration of the preceding ischemia. Here we compared sevoflurane and isoflurane with particular reference to their hemodynamic effects and ability to modify the effects of acute severe myocardial ischemia and reperfusion on ventricular arrhythmias and mortality in a porcine model of myocardial infarction. Female Large White pigs were premedicated with ketamine, midazolam, and atropine. Propofol was given intravenously for the anesthetic induction, and anesthesia was maintained with isoflurane or sevoflurane. Endovascular, fluoroscopy-guided, coronary procedures were performed to occlude the midleft anterior descending artery by using a coronary angioplasty balloon. After 75 min, the balloon catheter system was withdrawn and the presence of adequate reperfusion flow was verified. The pigs were followed for 2 mo, and overall mortality rate was calculated. The isoflurane group showed lower arterial pressure throughout the procedure, with the difference reaching statistical significance after induction of myocardial ischemia. The ventricular fibrillation rate was higher in isoflurane group (81.3%) than the sevoflurane group (51.7%; relative risk, 1.57 [1.03 to 2.4]). Overall survival was lower in the isoflurane group (75%) than the sevoflurane group (96.4%). In conclusion, in this porcine model of myocardial ischemia and reperfusion, sevoflurane was associated with higher hemodynamic stability and fewer ventricular arrhythmias and mortality than was isoflurane. PMID:21333167

  17. A porcine model of full-thickness burn, excision and skin autografting

    PubMed Central

    Branski, Ludwik K.; Mittermayr, Rainer; Herndon, David N.; Norbury, William B.; Masters, Oscar E.; Hofmann, Martina; Traber, Daniel L.; Redl, Heinz; Jeschke, Marc G.

    2008-01-01

    Acute burn wounds often require early excision and adequate coverage to prevent further hypothermia, protein and fluid losses, and the risk of infection. Meshed autologous skin grafts are generally regarded as the standard treatment for extensive full-thickness burns. Graft take and rate of wound healing, however, depend on several endogenous factors. This paper describes a standardized reproducible porcine model of burn and skin grafting which can be used to study the effects of topical treatments on graft take and re-epithelialization. Procedures provide a protocol for successful porcine burn wound experiments with special focus on pre-operative care, anesthesia, burn allocation, excision and grafting, postoperative treatment, dressing application, and specimen collection. Selected outcome measurements include percent area of wound closure by planimetry, wound assessment using a clinical assessment scale, and histological scoring. The use of this standardized model provides burn researchers with a valuable tool for the comparison of different topical drug treatments and dressing materials in a setting that closely mimics clinical reality. PMID:18617332

  18. Evaluation of aortic cannula jet lesions in a porcine cardiopulmonary bypass (CPB) model.

    PubMed

    Schnürer, C; Hager, M; Györi, G; Velik-Salchner, C; Moser, P L; Laufer, G; Lorenz, I H; Kolbitsch, C

    2011-02-01

    In cardiosurgery patients atherosclerotic debris displaced from the cannulation site but also from the opposite aortic wall by the "sandblast-like" effect of the high-pressure jet emanating from the cannula is a potential source of intraoperative arterial embolization and consequently postoperative neurologic dysfunction. The present study examined the extent to which shear stress exerted on the intact aortic intima by an aortic cannula jet stream can cause endothelial lesions that promote thrombogenesis and consequently thrombembolism. A single-stream, straight-tip aortic cannula was used in a porcine cardiopulmonary bypass (CPB) model. Following a 120-minute CPB pump run, a 60-minute stabilization period was allowed before sacrificing the pigs (N.=40) for histological evaluation of the ascending aorta and the brain. Opposite the cannulation site endothelial lesions (diameter: 3.81±1.3 mm; depth: 0.017±0.003 mm) were present in 22.5% (9/40) of aortic specimens. Cerebral thrombembolic lesions were not found. The present study showed that single-stream, straight-tip aortic cannulas caused jet lesions of the formerly intact aortic endothelium opposite the cannulation site in 22.5% of cases in a porcine CPB model. PMID:21224818

  19. Taenia solium: Development of an Experimental Model of Porcine Neurocysticercosis

    PubMed Central

    Fleury, Agnès; Trejo, Armando; Cisneros, Humberto; García-Navarrete, Roberto; Villalobos, Nelly; Hernández, Marisela; Villeda Hernández, Juana; Hernández, Beatriz; Rosas, Gabriela; Bobes, Raul J.; S. de Aluja, Aline; Sciutto, Edda; Fragoso, Gladis

    2015-01-01

    Human neurocysticercosis (NC) is caused by the establishment of Taenia solium larvae in the central nervous system. NC is a severe disease still affecting the population in developing countries of Latin America, Asia, and Africa. While great improvements have been made on NC diagnosis, treatment, and prevention, the management of patients affected by extraparenchymal parasites remains a challenge. The development of a T. solium NC experimental model in pigs that will allow the evaluation of new therapeutic alternatives is herein presented. Activated oncospheres (either 500 or 1000) were surgically implanted in the cerebral subarachnoid space of piglets. The clinical status and the level of serum antibodies in the animals were evaluated for a 4-month period after implantation. The animals were sacrificed, cysticerci were counted during necropsy, and both the macroscopic and microscopic characteristics of cysts were described. Based on the number of established cysticerci, infection efficiency ranged from 3.6% (1000 oncospheres) to 5.4% (500 oncospheres). Most parasites were caseous or calcified (38/63, 60.3%) and were surrounded by an exacerbated inflammatory response with lymphocyte infiltration and increased inflammatory markers. The infection elicited specific antibodies but no neurological signs. This novel experimental model of NC provides a useful tool to evaluate new cysticidal and anti-inflammatory approaches and it should improve the management of severe NC patients, refractory to the current treatments. PMID:26252878

  20. Taenia solium: Development of an Experimental Model of Porcine Neurocysticercosis.

    PubMed

    Fleury, Agnès; Trejo, Armando; Cisneros, Humberto; García-Navarrete, Roberto; Villalobos, Nelly; Hernández, Marisela; Villeda Hernández, Juana; Hernández, Beatriz; Rosas, Gabriela; Bobes, Raul J; de Aluja, Aline S; Sciutto, Edda; Fragoso, Gladis

    2015-01-01

    Human neurocysticercosis (NC) is caused by the establishment of Taenia solium larvae in the central nervous system. NC is a severe disease still affecting the population in developing countries of Latin America, Asia, and Africa. While great improvements have been made on NC diagnosis, treatment, and prevention, the management of patients affected by extraparenchymal parasites remains a challenge. The development of a T. solium NC experimental model in pigs that will allow the evaluation of new therapeutic alternatives is herein presented. Activated oncospheres (either 500 or 1000) were surgically implanted in the cerebral subarachnoid space of piglets. The clinical status and the level of serum antibodies in the animals were evaluated for a 4-month period after implantation. The animals were sacrificed, cysticerci were counted during necropsy, and both the macroscopic and microscopic characteristics of cysts were described. Based on the number of established cysticerci, infection efficiency ranged from 3.6% (1000 oncospheres) to 5.4% (500 oncospheres). Most parasites were caseous or calcified (38/63, 60.3%) and were surrounded by an exacerbated inflammatory response with lymphocyte infiltration and increased inflammatory markers. The infection elicited specific antibodies but no neurological signs. This novel experimental model of NC provides a useful tool to evaluate new cysticidal and anti-inflammatory approaches and it should improve the management of severe NC patients, refractory to the current treatments. PMID:26252878

  1. [The isolated perfused porcine kidney model for investigations concerning surgical therapy procedures].

    PubMed

    Peters, Kristina; Michel, Maurice Stephan; Matis, Ulrike; Häcker, Axel

    2006-01-01

    Experiments to develop innovative surgical therapy procedures are conventionally conducted on animals, as crucial aspects like tissue removal and bleeding disposition cannot be investigated in vitro. Extracorporeal organ models however reflect these aspects and could thus reduce the use of animals for this purpose fundamentally in the future. The aim of this work was to validate the isolated perfused porcine kidney model with regard to its use for surgical purposes on the basis of histological and radiological procedures. The results show that neither storage nor artificial perfusion led to any structural or functional damage which would affect the quality of the organ. The kidney model is highly suitable for simulating the main aspects of renal physiology and allows a constant calibration of perfusion pressure and tissue temperature. Thus, with only a moderate amount of work involved, the kidney model provides a cheap and readily available alternative to conventional animal experiments; it allows standardised experimental settings and provides valid results. PMID:17086351

  2. Immunohistochemistry of porcine skin.

    PubMed

    Wollina, U; Berger, U; Mahrle, G

    1991-01-01

    The present paper reports immunohistological findings in porcine skin, which were obtained by use of mono- and polyclonal antihuman antibodies and either alkaline phosphatase anti-alkaline phosphatase (APAAP) or peroxidase (POX) technique. Epidermal staining was observed with antibodies to keratins (K 8.12, RSKE 60), filaggrin, and calmodulin (ACAM). Staining of connective tissue and vessels was achieved using antibodies to vimentin (V9(1)), collagen type IV, and fibronectin. In general, these antibodies gave a staining pattern similar to that of normal human skin. The similarities of immunoreactivity to poly- and monoclonal antihuman antibodies in porcine and human skin render porcine skin a reliable model in biomedical research. PMID:1710864

  3. Percentile growth charts for biomedical studies using a porcine model.

    PubMed

    Corson, A M; Laws, J; Laws, A; Litten, J C; Lean, I J; Clarke, L

    2008-12-01

    Increasing rates of obesity and heart disease are compromising quality of life for a growing number of people. There is much research linking adult disease with the growth and development both in utero and during the first year of life. The pig is an ideal model for studying the origins of developmental programming. The objective of this paper was to construct percentile growth curves for the pig for use in biomedical studies. The body weight (BW) of pigs was recorded from birth to 150 days of age and their crown-to-rump length was measured over the neonatal period to enable the ponderal index (PI; kg/m3) to be calculated. Data were normalised and percentile curves were constructed using Cole's lambda-mu-sigma (LMS) method for BW and PI. The construction of these percentile charts for use in biomedical research will allow a more detailed and precise tracking of growth and development of individual pigs under experimental conditions. PMID:22444086

  4. Novel A20-gene-eluting stent inhibits carotid artery restenosis in a porcine model

    PubMed Central

    Zhou, Zhen-hua; Peng, Jing; Meng, Zhao-you; Chen, Lin; Huang, Jia-Lu; Huang, He-qing; Li, Li; Zeng, Wen; Wei, Yong; Zhu, Chu-Hong; Chen, Kang-Ning

    2016-01-01

    Background Carotid artery stenosis is a major risk factor for ischemic stroke. Although carotid angioplasty and stenting using an embolic protection device has been introduced as a less invasive carotid revascularization approach, in-stent restenosis limits its long-term efficacy and safety. The objective of this study was to test the anti-restenosis effects of local stent-mediated delivery of the A20 gene in a porcine carotid artery model. Materials and methods The pCDNA3.1EHA20 was firmly attached onto stents that had been collagen coated and treated with N-succinimidyl-3-(2-pyridyldithiol)propionate solution and anti-DNA immunoglobulin fixation. Anti-restenosis effects of modified vs control (the bare-metal stent and pCDNA3.1 void vector) stents were assessed by Western blot and scanning electron microscopy, as well as by morphological and inflammatory reaction analyses. Results Stent-delivered A20 gene was locally expressed in porcine carotids in association with significantly greater extent of re-endothelialization at day 14 and of neointimal hyperplasia inhibition at 3 months than stenting without A20 gene expression. Conclusion The A20-gene-eluting stent inhibits neointimal hyperplasia while promoting re-endothelialization and therefore constitutes a novel potential alternative to prevent restenosis while minimizing complications. PMID:27540277

  5. Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol

    PubMed Central

    Kaths, J. Moritz; Echeverri, Juan; Goldaracena, Nicolas; Louis, Kristine S.; Yip, Paul; John, Rohan; Mucsi, Istvan; Ghanekar, Anand; Bagli, Darius; Selzner, Markus; Robinson, Lisa A.

    2016-01-01

    Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality of life when compared to dialysis. Although the last few decades have seen major improvements in patient outcomes following kidney transplantation, the increasing shortage of available organs represents a severe problem worldwide. To expand the donor pool, marginal kidney grafts recovered from extended criteria donors (ECD) or donated after circulatory death (DCD) are now accepted for transplantation. To further improve the postoperative outcome of these marginal grafts, research must focus on new therapeutic approaches such as alternative preservation techniques, immunomodulation, gene transfer, and stem cell administration. Experimental studies in animal models are the final step before newly developed techniques can be translated into clinical practice. Porcine kidney transplantation is an excellent model of human transplantation and allows investigation of novel approaches. The major advantage of the porcine model is its anatomical and physiological similarity to the human body, which facilitates the rapid translation of new findings to clinical trials. This article offers a surgical step-by-step protocol for an autotransplantation model and highlights key factors to ensure experimental success. Adequate pre- and postoperative housing, attentive anesthesia, and consistent surgical techniques result in favorable postoperative outcomes. Resection of the contralateral native kidney provides the opportunity to assess post-transplant graft function. The placement of venous and urinary catheters and the use of metabolic cages allow further detailed evaluation. For long-term follow-up studies and investigation of alternative graft preservation techniques, autotransplantation models are superior to allotransplantation models, as they avoid the confounding bias posed by rejection and immunosuppressive medication. PMID

  6. Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol.

    PubMed

    Kaths, J Moritz; Echeverri, Juan; Goldaracena, Nicolas; Louis, Kristine S; Yip, Paul; John, Rohan; Mucsi, Istvan; Ghanekar, Anand; Bagli, Darius; Selzner, Markus; Robinson, Lisa A

    2016-01-01

    Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality of life when compared to dialysis. Although the last few decades have seen major improvements in patient outcomes following kidney transplantation, the increasing shortage of available organs represents a severe problem worldwide. To expand the donor pool, marginal kidney grafts recovered from extended criteria donors (ECD) or donated after circulatory death (DCD) are now accepted for transplantation. To further improve the postoperative outcome of these marginal grafts, research must focus on new therapeutic approaches such as alternative preservation techniques, immunomodulation, gene transfer, and stem cell administration. Experimental studies in animal models are the final step before newly developed techniques can be translated into clinical practice. Porcine kidney transplantation is an excellent model of human transplantation and allows investigation of novel approaches. The major advantage of the porcine model is its anatomical and physiological similarity to the human body, which facilitates the rapid translation of new findings to clinical trials. This article offers a surgical step-by-step protocol for an autotransplantation model and highlights key factors to ensure experimental success. Adequate pre- and postoperative housing, attentive anesthesia, and consistent surgical techniques result in favorable postoperative outcomes. Resection of the contralateral native kidney provides the opportunity to assess post-transplant graft function. The placement of venous and urinary catheters and the use of metabolic cages allow further detailed evaluation. For long-term follow-up studies and investigation of alternative graft preservation techniques, autotransplantation models are superior to allotransplantation models, as they avoid the confounding bias posed by rejection and immunosuppressive medication. PMID

  7. A porcine model of early atrial fibrillation using a custom-built, radio transmission-controlled pacemaker.

    PubMed

    Schwarzl, Michael; Alogna, Alessio; Zweiker, David; Verderber, Jochen; Huber, Stefan; Manninger, Martin; Scherr, Daniel; Antoons, Gudrun; Pieske, Burkert M; Post, Heiner; Lueger, Andreas

    2016-01-01

    Mechanisms underlying atrial remodeling toward atrial fibrillation (AF) are incompletely understood. We induced AF in 16 pigs by 6weeks of rapid atrial pacing (RAP, 600bpm) using a custom-built, telemetrically controlled pacemaker. AF evolution was monitored three times per week telemetrically in unstressed, conscious animals. We established a dose-response relationship between RAP duration and occurrence of sustained AF >60minutes. Left atrial (LA) dilatation was present already at 2weeks of RAP. There was no evidence of left ventricular heart failure after 6weeks of RAP. As a proof-of-principle, arterial hypertension was induced in 5/16 animals by implanting desoxycorticosterone acetate (DOCA, an aldosterone-analog) subcutaneously to accelerate atrial remodeling. RAP+DOCA resulted in increased AF stability with earlier onset of sustained AF and accelerated anatomical atrial remodeling with more pronounced LA dilatation. This novel porcine model can serve to characterize effects of maladaptive stimuli or protective interventions specifically during early AF. PMID:26803554

  8. In vivo tissue response following implantation of shape memory polyurethane foam in a porcine aneurysm model

    PubMed Central

    Rodriguez, Jennifer N.; Clubb, Fred J.; Wilson, Thomas S.; Miller, Matthew W.; Fossum, Theresa W.; Hartman, Jonathan; Tuzun, Egemen; Singhal, Pooja; Maitland, Duncan J.

    2014-01-01

    Cerebral aneurysms treated by traditional endovascular methods using platinum coils have a tendency to be unstable, either due to chronic inflammation, compaction of coils, or growth of the aneurysm. We propose to use alternate filling methods for the treatment of intracranial aneurysms using polyurethane based shape memory polymer (SMP) foams. SMP polyurethane foams were surgically implanted in a porcine aneurysm model to determine biocompatibility, localized thrombogenicity, and their ability to serve as a stable filler material within an aneurysm. The degree of healing was evaluated via gross observation, histopathology and low vacuum scanning electron microscopy (LV-SEM) imaging after zero, thirty and ninety days. Clotting was initiated within the SMP foam at time zero (less than one hour exposure to blood prior to euthanization), partial healing was observed at thirty days, and almost complete healing had occurred at ninety days in vivo, with minimal inflammatory response. PMID:23650278

  9. A retrospective review of burn dressings on a porcine burn model.

    PubMed

    Wang, Xue-Qing; Kravchuk, Olena; Kimble, Roy M

    2010-08-01

    This is a study to compare wound healing among three types of dressings on a porcine model with deep-dermal-partial-thickness burns. The burns in this study were from eight animal trials conducted in the past for other purposes and only burns with a uniform pale appearance that had served as controls in original experiments were selected. In total, there were 57 burns in 33 pigs, using one of following three dressings: Acticoat (Silver) (3 trials), Jelonet (Gauze) (3 trials), and Solosite Gel/Jelonet (Gel/Gauze) (2 trials). The wound healing assessments included wound re-epithelialisation during a 6-week period, clinical and histological scar assessments at week 6 after burn. Of all wound healing/scar assessments, only re-epithelialisation showed statistical difference between dressings. Earlier re-epithelialisation was observed in Gel/Gauze dressings compared to Silver and/or Gauze dressings. However, this study revealed huge variation in wound healing outcome between 3 trials within both Silver and/or Gauze dressings, supported by significant differences on re-epithelialisation, clinical and histological scar measurements. In addition, it was found that larger animals healed better than smaller ones, based on weights from 21 pigs. Of all dressings, Silver delivers the best protection for wound colonization/infection. Wound colonization/infection was found to confine wound healing and lead to thinner RND in scars. From this study, we cannot find enough evidence to suggest the beneficial effect of one dressing(s) over others on burn wound healing outcome on a porcine model with small deep-dermal-partial-thickness burns with a relative small sample size. PMID:19864074

  10. Vascular histopathologic reaction to pulmonary artery banding in an in vivo growing porcine model.

    PubMed

    Nedorost, Lukáš; Uemura, Hideki; Furck, Anke; Saeed, Imran; Slavik, Zdenek; Kobr, Jiří; Tonar, Zbyněk

    2013-10-01

    Pulmonary artery banding (PAB) is used as a surgical palliation to reduce excessive pulmonary blood flow caused by congenital heart defects. Due to the lack of microscopic studies dealing with the tissue remodeling caused by contemporary PAB materials, this study aimed to assess histologic changes associated with PAB surgery by analyzing local tissue reaction to the presence of Gore-Tex strips fixed around the pulmonary artery. Gore-Tex strips were used for PAB in a growing porcine model. After 5 weeks, histologic samples with PAB (n = 5) were compared with healthy pulmonary arterial segments distal to the PAB or from a sham-treated animal (n = 1). Stereology was used to quantify the density of the vasa vasorum and the area fraction of elastin, smooth muscle actin, macrophages, and nervi vasorum within the pulmonary arterial wall. The null hypothesis stated that samples did not differ histopathologically from adjacent vascular segments or sham-treated samples. The PAB samples had a greater area fraction of macrophages, a lower amount of nervi vasorum, and a tendency toward decreased smooth muscle content compared with samples that had no PAB strips. There was no destruction of elastic membranes, no medionecrosis, no pronounced inflammatory infiltration or foreign body reaction, and no vasa vasorum deficiency after the PAB. All the histopathologic changes were limited to the banded vascular segment and did not affect distal parts of the pulmonary artery. The study results show the tissue reaction of palliative PAB and suggest that Gore-Tex strips used contemporarily for PAB do not cause severe local histologic damage to the banded segment of the pulmonary arterial wall after 5 weeks in a porcine PAB model. PMID:23591800

  11. Bovine Serum Albumin Glutaraldehyde for Completely Sutureless Laparoscopic Heminephrectomy in a Survival Porcine Model

    PubMed Central

    Gamboa, Aldrin Joseph R.; Kaplan, Adam G.; Khosravi, Amanda; Truong, Hung; Andrade, Lorena; Lin, Rachelle; Alipanah, Reza; Ortiz, Cervando; McCormick, David; Box, Geoffrey N.; Lee, Hak J.; Deane, Leslie A.; Edwards, Robert A.; McDougall, Elspeth M.; Clayman, Ralph V.

    2010-01-01

    Abstract Introduction Laparoscopic partial nephrectomy (LPN) has not received widespread clinical application because of its technical challenge. Bovine serum albumin glutaraldehyde (BSAG) is a hemostatic agent that is independent of the clotting cascade. We evaluated the use of BSAG as the sole agent for parenchymal and collecting system closure during LPN in a survival porcine model. Methods Eighteen pigs underwent hilar clamping and LPN by longitudinal excision of the lateral one-third of the right kidney. The opened collecting system was covered with oxidized cellulose to prevent BSAG seepage into the urinary tract. BSAG was allowed to set for 10 or 5 minutes. Twelve animals underwent survival LPN BSAG only closure; six control pigs were acutely studied using saline. Urinary extravasation was evaluated by injection of furosemide and indigo carmine, and then evaluating the renal surface and bladder catheter drainage for dye. A subjective bleeding score was assigned after hilum unclamping. At 6 weeks, BSAG kidneys were harvested for burst pressure testing and histopathological analysis. Results All 12 pigs survived for 6 weeks. No pigs had urinary extravasation. Mean percentage of kidney removed by weight was 19%. Mean warm ischemia time was 29 minutes. Five pigs required a second BSAG application to achieve a bleeding score of 0. Mean arterial and collecting system burst pressures were 301.8 and 322.4 mm Hg, respectively. Mean postoperative creatinine increase was 0.07 mg/dL. Conclusion BSAG for completely sutureless LPN in a survival porcine model was feasible. PMID:20059350

  12. Histologic Characterization of Acellular Dermal Matrices in a Porcine Model of Tissue Expander Breast Reconstruction

    PubMed Central

    Carruthers, Christopher A.; Dearth, Christopher L.; Reing, Janet E.; Kramer, Caroline R.; Gagne, Darcy H.; Crapo, Peter M.; Garcia, Onelio; Badhwar, Amit; Scott, Jeffrey R.

    2015-01-01

    Background: Acellular dermal matrices (ADMs) have been commonly used in expander-based breast reconstruction to provide inferolateral prosthesis coverage. Although the clinical performance of these biologic scaffold materials varies depending on a number of factors, an in-depth systematic characterization of the host response is yet to be performed. The present study evaluates the biochemical composition and structure of two ADMs, AlloDerm® Regenerative Tissue Matrix and AlloMax™ Surgical Graft, and provides a comprehensive spatiotemporal characterization in a porcine model of tissue expander breast reconstruction. Methods: Each ADM was characterized with regard to thickness, permeability, donor nucleic acid content, (residual double-stranded DNA [dsDNA]), and growth factors (basic fibroblast growth factor [bFGF], vascular endothelial growth factor [VEGF], and transforming growth factor-beta 1 [TGF-β1]). Cytocompatibility was evaluated by in vitro cell culture on the ADMs. The host response was evaluated at 4 and 12 weeks at various locations within the ADMs using established metrics of the inflammatory and tissue remodeling response: cell infiltration, multinucleate giant cell formation, extent of ADM remodeling, and neovascularization. Results: AlloMax incorporated more readily with surrounding host tissue as measured by earlier and greater cell infiltration, fewer foreign body giant cells, and faster remodeling of ADM. These findings correlated with the in vitro composition and cytocompatibility analysis, which showed AlloMax to more readily support in vitro cell growth. Conclusions: AlloMax and AlloDerm demonstrated distinct remodeling characteristics in a porcine model of tissue expander breast reconstruction. PMID:24941900

  13. Endoscopic spray cryotherapy for genitourinary malignancies: safety and efficacy in a porcine model

    PubMed Central

    Power, Nicholas E.; Silberstein, Jonathan L.; Tarin, Tatum; Au, Joyce; Thorner, Daniel; Ezell, Paula; Monette, Sébastien; Fong, Yuman; Rusch, Valerie; Finley, David

    2013-01-01

    Objective: To examine the effects and safety of using endoscopic spray cryotherapy (ESC) on bladder, ureteral, and renal pelvis urothelium in a live porcine model. Subjects and methods: ESC treatments were systematically applied to urothelial sites in the bladder, ureter, and renal pelvis of eight female Yorkshire swine in a prospective trial. Freeze–thaw cycles ranged from 5 to 60 s/cycle for one to six cycles using a 7 French cryotherapy catheter. Tissue was evaluated histologically for treatment-related effects. Acute physiologic effects were evaluated with pulse oximetry, Doppler sonography, and postmortem findings. Results: In bladder, treatment depth was inconsistent regardless of dose, demonstrating urothelial necrosis in one, muscularis propria depth necrosis in two, and full thickness necrosis in all remaining samples. In ureter, full thickness necrosis was seen in all samples, even with the shortest spray duration (5 s/cycle for six cycles or 30 s/cycle for one cycle). Treatment to the renal pelvis was complicated by adiabatic gas expansion of liquid nitrogen to its gaseous state, resulting in high intraluminal pressures requiring venting to avoid organ perforation, even at the lowest treatment settings. At a planned dose of 5 s/cycle for six cycles of the first renal pelvis animal, treatment was interrupted by sudden and unrecoverable cardiopulmonary failure after three cycles. Repeated studies replicated this event. Ultrasound and immediate necropsy confirmed the creation of a large gaseous embolism and reproducible cardiopulmonary effects. Conclusion: ESC in a porcine urothelial treatment model results in full-thickness tissue necrosis in bladder, ureter, and renal pelvis at a minimal treatment settings of 5 s/cycle for six cycles. Adiabatic gas expansion may result in fatal pyelovenous gas embolism and collateral organ injury, as seen in both animals receiving treatment to the renal pelvis in this study. These results raise safety concerns for use

  14. Monitoring Survivability and Infectivity of Porcine Epidemic Diarrhea Virus (PEDv) in the Infected On-Farm Earthen Manure Storages (EMS)

    PubMed Central

    Tun, Hein M.; Cai, Zhangbin; Khafipour, Ehsan

    2016-01-01

    In recent years, porcine epidemic diarrhea virus (PEDv) has caused major epidemics, which has been a burden to North America’s swine industry. Low infectious dose and high viability in the environment are major challenges in eradication of this virus. To further understand the viability of PEDv in the infected manure, we longitudinally monitored survivability and infectivity of PEDv in two open earthen manure storages (EMS; previously referred to as lagoon) from two different infected swine farms identified in the province of Manitoba, Canada. Our study revealed that PEDv could survive up to 9 months in the infected EMS after the initial outbreak in the farm. The viral load varied among different layers of the EMS with an average of 1.1 × 105 copies/ml of EMS, independent of EMS temperature and pH. In both studied EMS, the evidence of viral replication was observed through increased viral load in the later weeks of the samplings while there was no new influx of infected manure into the EMS, which was suggestive of presence of potential alternative hosts for PEDv within the EMS. Decreasing infectivity of virus over time irrespective of increased viral load suggested the possibility of PEDv evolution within the EMS and perhaps in the new host that negatively impacted virus infectivity. Viral load in the top layer of the EMS was low and mostly non-infective suggesting that environmental factors, such as UV and sunlight, could diminish the replicability and infectivity of the virus. Thus, frequent agitation of the EMS that could expose virus to UV and sunlight might be a potential strategy for reduction of PEDv load and infectivity in the infected EMS. PMID:27014197

  15. Experimental validation of a new biphasic model of the contact mechanics of the porcine hip

    PubMed Central

    Wang, Qianqian; Jin, Zhongmin; Williams, Sophie; Fisher, John; Wilcox, Ruth K

    2014-01-01

    Hip models that incorporate the biphasic behaviour of articular cartilage can improve understanding of the joint function, pathology of joint degeneration and effect of potential interventions. The aim of this study was to develop a specimen-specific biphasic finite element model of a porcine acetabulum incorporating a biphasic representation of the articular cartilage and to validate the model predictions against direct experimental measurements of the contact area in the same specimen. Additionally, the effect of using a different tension–compression behaviour for the solid phase of the articular cartilage was investigated. The model represented different radial clearances and load magnitudes. The comparison of the finite element predictions and the experimental measurement showed good agreement in the location, size and shape of the contact area, and a similar trend in the relationship between contact area and load was observed. There was, however, a deviation of over 30% in the magnitude of the contact area, which might be due to experimental limitations or to simplifications in the material constitutive relationships used. In comparison with the isotropic solid phase model, the tension–compression solid phase model had better agreement with the experimental observations. The findings provide some confidence that the new biphasic methodology for modelling the cartilage is able to predict the contact mechanics of the hip joint. The validation provides a foundation for future subject-specific studies of the human hip using a biphasic cartilage model. PMID:24878736

  16. Resolving the viscoelasticity and anisotropy dependence of the mechanical properties of skin from a porcine model.

    PubMed

    Wong, W L E; Joyce, T J; Goh, K L

    2016-04-01

    The mechanical response of skin to external loads is influenced by anisotropy and viscoelasticity of the tissue, but the underlying mechanisms remain unclear. Here, we report a study of the main effects of tissue orientation (TO, which is linked to anisotropy) and strain rate (SR, a measure of viscoelasticity), as well as the interaction effects between the two factors, on the tensile properties of skin from a porcine model. Tensile testing to rupture of porcine skin tissue was conducted to evaluate the sensitivity of the tissue modulus of elasticity (E) and fracture-related properties, namely maximum stress [Formula: see text] and strain [Formula: see text] at [Formula: see text], to varying SR and TO. Specimens were excised from the abdominal skin in two orientations, namely parallel (P) and right angle (R) to the torso midline. Each TO was investigated at three SR levels, namely 0.007-0.015 [Formula: see text] (low), 0.040 [Formula: see text] (mid) and 0.065 [Formula: see text] (high). Two-factor analysis of variance revealed that the respective parameters responded differently to varying SR and TO. Significant changes in the [Formula: see text] were observed with different TOs but not with SR. The [Formula: see text] decreased significantly with increasing SR, but no significant variation was observed for different TOs. Significant changes in E were observed with different TOs; E increased significantly with increasing SR. More importantly, the respective mechanical parameters were not significantly influenced by interactions between SR and TO. These findings suggest that the trends associated with the changes in the skin mechanical properties may be attributed partly to differences in the anisotropy and viscoelasticity but not through any interaction between viscoelasticity and anisotropy. PMID:26156308

  17. Three dimensional electromechanical model of porcine heart with penetrating wound injury.

    PubMed

    Usyk, Taras; Kerckhoffs, Roy

    2005-01-01

    The aim of this study is development a prototype computational model of the pig heart that can be used to predict physiological responses to a penetrating wound injury. The pig has been chosen for this model studies because it shares many anatomical similarities with humans. Three-dimensional cubic Hermite finite element meshes based on detailed measurements of porcine anatomy combined into an integrated anatomic model. The pig ventricular model includes detailed left and right ventricular geometry and myofiber and laminar sheet orientations throughout the mesh. The cardiac mesh was refined and monodomain equations for action potential propagation solved using well-established collocation-Galerkin finite element methods. The membrane kinetic equations for the action potential model was based on detailed cellular models of transmembrane ionic fluxes and intracellular calcium fluxes in canine ventricular myocytes and human atrial myocytes. We modified the anisotropic myocardial conductivity tensor on the endocardial surface of the ventricles by making use of a surface model fitted to measured of Purkinje fiber network anatomy. The mechanical model compute regional three-dimensional stress and strain distributions using anisotropic constitutive laws referred to local material coordinate axes defined by local myofiber and laminar sheet orientations. Passive myocardial mechanics modeled using exponential orthotropic strain energy functions. Active systolic myocardial stresses computed from a multi-scale model that uses crossbridge theory to predict calcium-activated sarcomere length- and velocity-dependent tension filament tension. Since the electrical and mechanical models use a common finite element mesh as the parent parametric framework and both models are solved within our custom finite element package, it is straightforward to couple these models, as we have recently done for a model of coupled ventricular electromechanics. We apply the coupled electromechanical

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

    PubMed Central

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

    2014-01-01

    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. PMID:25190415

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

    PubMed

    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. PMID:25190415

  20. Development and translational imaging of a TP53 porcine tumorigenesis model

    PubMed Central

    Sieren, Jessica C.; Meyerholz, David K.; Wang, Xiao-Jun; Davis, Bryan T.; Newell, John D.; Hammond, Emily; Rohret, Judy A.; Rohret, Frank A.; Struzynski, Jason T.; Goeken, J. Adam; Naumann, Paul W.; Leidinger, Mariah R.; Taghiyev, Agshin; Van Rheeden, Richard; Hagen, Jussara; Darbro, Benjamin W.; Quelle, Dawn E.; Rogers, Christopher S.

    2014-01-01

    Cancer is the second deadliest disease in the United States, necessitating improvements in tumor diagnosis and treatment. Current model systems of cancer are informative, but translating promising imaging approaches and therapies to clinical practice has been challenging. In particular, the lack of a large-animal model that accurately mimics human cancer has been a major barrier to the development of effective diagnostic tools along with surgical and therapeutic interventions. Here, we developed a genetically modified porcine model of cancer in which animals express a mutation in TP53 (which encodes p53) that is orthologous to one commonly found in humans (R175H in people, R167H in pigs). TP53R167H/R167H mutant pigs primarily developed lymphomas and osteogenic tumors, recapitulating the tumor types observed in mice and humans expressing orthologous TP53 mutant alleles. CT and MRI imaging data effectively detected developing tumors, which were validated by histopathological evaluation after necropsy. Molecular genetic analyses confirmed that these animals expressed the R167H mutant p53, and evaluation of tumors revealed characteristic chromosomal instability. Together, these results demonstrated that TP53R167H/R167H pigs represent a large-animal tumor model that replicates the human condition. Our data further suggest that this model will be uniquely suited for developing clinically relevant, noninvasive imaging approaches to facilitate earlier detection, diagnosis, and treatment of human cancers. PMID:25105366

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

    SciTech Connect

    Muehlenbruch, Georg Nikoubashman, Omid; Steffen, Bjoern; Dadak, Mete; Palmowski, Moritz; Wiesmann, Martin

    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.

  2. Protective effects of N-acetylcysteine on acetic acid-induced colitis in a porcine model

    PubMed Central

    2013-01-01

    Background Ulcerative colitis is a chronic inflammatory disease and involves multiple etiological factors. Acetic acid (AA)-induced colitis is a reproducible and simple model, sharing many characteristics with human colitis. N-acetylcysteine (NAC) has been widely used as an antioxidant in vivo and in vitro. NAC can affect several signaling pathways involving in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and inflammatory response. Therefore, NAC may not only protect against the direct injurious effects of oxidants, but also beneficially alter inflammatory events in colitis. This study was conducted to investigate whether NAC could alleviate the AA-induced colitis in a porcine model. Methods Weaned piglets were used to investigate the effects of NAC on AA-induced colitis. Severity of colitis was evaluated by colon histomorphology measurements, histopathology scores, tissue myeloperoxidase activity, as well as concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon. The protective role of NAC was assessed by measurements of antioxidant status, growth modulator, cell apoptosis, and tight junction proteins. Abundances of caspase-3 and claudin-1 proteins in colonic mucosae were determined by the Western blot method. Epidermal growth factor receptor, amphiregulin, tumor necrosis factor-alpha (TNF-α), and toll-like receptor 4 (TLR4) mRNA levels in colonic mucosae were quantified using the real-time fluorescent quantitative PCR. Results Compared with the control group, AA treatment increased (P < 0.05) the histopathology scores, intraepithelial lymphocyte (IEL) numbers and density in the colon, myeloperoxidase activity, the concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon, while reducing (P < 0.05) goblet cell numbers and the protein/DNA ratio in the colonic mucosa. These adverse effects of AA were partially ameliorated (P < 0.05) by dietary

  3. Modeling the adaptive permeability response of porcine iliac arteries to acute changes in mural shear.

    PubMed

    Hazel, A L; Grzybowski, D M; Friedman, M H

    2003-04-01

    The hypothesis that much of the uptake of macromolecules by the vascular wall takes place while the endothelial lining is adapting to changes in its hemodynamic environment is being tested by a series of in vivo measurements of the uptake of Evans-blue-dye-labeled albumin by porcine iliac arteries subjected to acute changes in blood flow. The uptake data are interpreted through an ad hoc model of the dynamic permeability response that is proposed to accompany alterations in mural shear. The model is able to correlate, with a single set of parameters, the vascular response to a variety of experimental protocols, including sustained step increases and decreases in shear, and alternations in shear of various periods. The best-fit parameters of the model suggest that the adaptive response to an increase in shear proceeds with a latency of approximately 1.5 min and a time constant of approximately 90 min that is substantially shorter than the response to a decrease in shear. PMID:12723682

  4. A Porcine Model of Traumatic Brain Injury via Head Rotational Acceleration.

    PubMed

    Cullen, D Kacy; Harris, James P; Browne, Kevin D; Wolf, John A; Duda, John E; Meaney, David F; Margulies, Susan S; Smith, Douglas H

    2016-01-01

    Unique from other brain disorders, traumatic brain injury (TBI) generally results from a discrete biomechanical event that induces rapid head movement. The large size and high organization of the human brain makes it particularly vulnerable to traumatic injury from rotational accelerations that can cause dynamic deformation of the brain tissue. Therefore, replicating the injury biomechanics of human TBI in animal models presents a substantial challenge, particularly with regard to addressing brain size and injury parameters. Here we present the historical development and use of a porcine model of head rotational acceleration. By scaling up the rotational forces to account for difference in brain mass between swine and humans, this model has been shown to produce the same tissue deformations and identical neuropathologies found in human TBI. The parameters of scaled rapid angular accelerations applied for the model reproduce inertial forces generated when the human head suddenly accelerates or decelerates in falls, collisions, or blunt impacts. The model uses custom-built linkage assemblies and a powerful linear actuator designed to produce purely impulsive non-impact head rotation in different angular planes at controlled rotational acceleration levels. Through a range of head rotational kinematics, this model can produce functional and neuropathological changes across the spectrum from concussion to severe TBI. Notably, however, the model is very difficult to employ, requiring a highly skilled team for medical management, biomechanics, neurological recovery, and specialized outcome measures including neuromonitoring, neurophysiology, neuroimaging, and neuropathology. Nonetheless, while challenging, this clinically relevant model has proven valuable for identifying mechanisms of acute and progressive neuropathologies as well as for the evaluation of noninvasive diagnostic techniques and potential neuroprotective treatments following TBI. PMID:27604725

  5. Intracoronary photodynamic therapy reduces neointimal growth without suppressing re‐endothelialisation in a porcine model

    PubMed Central

    Waksman, R; Leitch, I M; Roessler, J; Yazdi, H; Seabron, R; Tio, F; Scott, R W; Grove, R I; Rychnovsky, S; Robinson, B; Pakala, R; Cheneau, E

    2006-01-01

    Objective To examine the effects of intracoronary PhotoPoint photodynamic therapy (PDT) with a new photosensitiser, MV0611, in the overstretch balloon and stent porcine models of restenosis. Methods 28 pigs were injected with 3 mg/kg of MV0611 systemically 4 h before the procedure. Animals were divided into either the balloon overstretch injury (BI) group (n  =  19) or the stented group (n  =  9). After BI, a centred delivery catheter was positioned in the artery to cover the injured area, and light (532 nm, 125 J/cm2) was applied to activate the drug (n  =  10). Control arteries (n  =  9) were not activated by light. In the stented group, the drug was light activated before stent deployment. Serial sections of vessels were processed 14 days after treatment in the BI group and 30 days after treatment in the stented group for histomorphometric or immunohistochemical analysis. Results Intracoronary PDT significantly reduced intimal thickness in both BI and stented arteries (about 65%: 0.22 (SEM 0.05) mm v 0.62 (0.05) mm, p < 0.01; and about 26%: 0.40 (0.04) mm v 0.54 (0.04) mm, p < 0.01, respectively). PDT increased luminal area by ⩽ 60% and 50% within BI and stented arteries (3.43 (0.27) mm2v 5.51 (0.52) mm2, p < 0.05; 4.0 (0.02) mm2v 6.0 (0.16) mm2, p < 0.01), respectively. Complete re‐endothelialisation was observed by immunohistochemical and gross histological analyses in all PDT and control arteries. There were no cases of aneurysm formation or thrombosis. Conclusion Intracoronary PhotoPoint PDT with MV0611 reduces intimal proliferation without suppressing re‐endothelialisation in a porcine model of restenosis. PMID:16399853

  6. Model based vibration monitoring

    SciTech Connect

    Esat, I.; Paya, B.; Badi, M.N.M.

    1996-11-01

    The principal source of vibratory excitation of gear system is the unsteady component of the relative angular motion of pair of meshing spur gears. This vibratory excitation is described by the transmission error. The transmission error present itself as a varying force at the contact point of the meshing gear teeth. The varying force is also influenced by the varying tooth stiffness due to change of orientation of teeth relative to each other, during the contact phase of each pair. Such a varying force produces both lateral and torsional excitation to the gear system. This paper presents analytical formulation of a simple two meshing spur gear system as a three mass system (18 DOF). The mathematical model also incorporates the analytical formulation of the tooth stiffness. The analytical results are compared with the experimental results. At this stage of analysis the procedure developed for handling the nonlinear influences of the tooth geometry is not fully implemented and the tooth stiffness taken as a constant value representing the average tooth stiffness. The comparison between the analytical and experimental results are encouraging as three main frequency obtained from FFT of the experimental results correlates very closely with the analytical results.

  7. Systemic Inflammatory Response After Natural Orifice Translumenal Surgery: Transvaginal Cholecystectomy in a Porcine Model

    PubMed Central

    Fan, Joe K. M.; Tong, Daniel K. H.; HO, David W. Y.; Luk, John; Law, Simon

    2009-01-01

    Objective: We analyzed circulating TNF-α and IL-6 to determine systemic inflammatory responses associated with transvaginal cholecystectomy in a porcine model. Methods: Six female pigs were used for a survival study after transvaginal cholecystectomy (NOTES group) using endoscopic submucosal dissection (ESD) instruments and a single-channel endoscope. Blood was drawn preoperatively and 24 hours and 48 hours postoperatively. Four pigs were used as controls. In addition, laparoscopic cholecystectomy was performed in 2 pigs for laparoscopic control. Results: In all 6 pigs in the NOTES group, no major intraoperative complications occurred. No significant differences were found between control, laparoscopic, and NOTES groups in terms of preoperative IL-6 level (P=0.897) and at 24 hours (P=0.790), and 48 hours postoperatively (P=0.945). Similarly, there was no significant difference in mean preoperative (P=0.349) and mean day 2 postoperative TNF-α levels (P=0.11). But a significant increase in day 1 postoperative TNF-α levels in the laparoscopic group compared with that in the control and NOTES groups was observed (P=0.049). One limitation of our study is that the sample size was relatively small. Conclusion: NOTES is safe in animal models in terms of anatomical and cellular level changes with minimal systemic inflammatory host responses elicited. Further study needs to be carried out in humans before NOTES can be recommended for routine use. PMID:19366533

  8. Acellular hydrogel for regenerative burn wound healing: translation from a porcine model

    PubMed Central

    Papa, Arianne; Burke, Jacqueline; Volk, Susan W; Gerecht, Sharon

    2015-01-01

    Currently available skin grafts and skin substitute for healing following third-degree burn injuries is fraught with complications, often resulting in long-term physical and psychological sequelae. Synthetic treatment that can promote wound healing in a regenerative fashion would provide an off-the-shelf, non-immunogenic strategy to improve clinical care of severe burn wounds. Here, we demonstrate vulnerary efficacy and accelerated healing mechanism of dextran-based hydrogel in third-degree porcine burn model. The model was optimized to allow examination of the hydrogel treatment for clinical translation and its regenerative response mechanisms. Hydrogel treatment accelerated third-degree burn wound healing by rapid wound closure, improved reepithelialization, enhanced extracellular matrix remodeling, and greater nerve reinnervation, compared to the dressing treated group. These effects appear to be mediated through the ability of the hydrogel to facilitate a rapid but brief initial inflammatory response that coherently stimulates neovascularization within the granulation tissue during the first week of treatment, followed by an efficient vascular regression to promote a regenerative healing process. Our results suggest that the dextran-based hydrogels may substantially improve healing quality and reduce skin grafting incidents and thus pave the way for clinical studies to improve the care of severe burn injury patients. PMID:26358387

  9. Finite element model of the temperature increase in excised porcine cadaver iris during direct illumination by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Kurtz, Ronald M.; Juhasz, Tibor

    2012-07-01

    In order to model the thermal effect of laser exposure of the iris during laser corneal surgery, we simulated the temperature increase in porcine cadaver iris. The simulation data for the 60 kHz FS60 Laser showed that the temperature increased up to 1.23°C and 2.45°C (at laser pulse energy 1 and 2 µJ, respectively) by the 24 second procedure time. Calculated temperature profiles show good agreement with data obtained from ex vivo experiments using porcine cadaver iris. Simulation results of different types of femtosecond lasers indicate that the Laser in situ keratomileusis procedure does not present a safety hazard to the iris.

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

    PubMed Central

    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). PMID:26241648

  11. Computed Tomography Perfusion Imaging Detection of Microcirculatory Dysfunction in Small Intestinal Ischemia-Reperfusion Injury in a Porcine Model

    PubMed Central

    Shi, Haifeng; Li, Ruokun; Qiang, Jinwei; Li, Ying; Wang, Li; Sun, Rongxun

    2016-01-01

    Objective To evaluate multi-slice computed tomography (CT) perfusion imaging (CTPI) for identifying microcirculatory dysfunction in small intestinal ischemia−reperfusion (IR) injury in a porcine model. Materials and Methods Fifty-two pigs were randomly divided into 4 groups: (1) the IR group (n = 24), where intestinal ischemia was induced by separating and clamping the superior mesenteric artery (SMA) for 2 h, followed by reperfusion for 1, 2, 3, and 4 h (IR-1h, IR-2h, IR-3h, and IR-4h; n = 6, respectively); (2) the sham-operated (SO) group (n = 20), where the SMA was separated without clamping and controlled at postoperative 3, 4, 5, and 6 h (SO-3h, SO-4h, SO-5h, and SO-6h; n = 5, respectively); (3) the ischemia group (n = 4), where the SMA was separated and clamped for 2 h, without reperfusion, and (4) baseline group (n = 4), an additional group that was not manipulated. Small intestinal CTPI was performed at corresponding time points and perfusion parameters were obtained. The distal ileum was resected to measure the concentrations of malondialdehyde (MDA) and superoxide dismutase (SOD) and for histopathological examination. Results The perfusion parameters of the IR groups showed significant differences compared with the corresponding SO groups and the baseline group (before ischemia). The blood flow (BF), blood volume (BV), and permeability surface (PS) among the 4 IR groups were significantly different. BF and BV were significantly negatively correlated with MDA, and significantly positively correlated with SOD in the IR groups. Histopathologically, the effects of the 2-h ischemic loops were not significantly exacerbated by reperfusion. Conclusion CTPI can be a valuable tool for detecting microcirculatory dysfunction and for dynamic monitoring of small intestinal IR injury. PMID:27458696

  12. Antibody Responses to Sarcoptes scabiei Apolipoprotein in a Porcine Model: Relevance to Immunodiagnosis of Recent Infection

    PubMed Central

    Rampton, Melanie; Walton, Shelley F.; Holt, Deborah C.; Pasay, Cielo; Kelly, Andrew; Currie, Bart J.; McCarthy, James S.; Mounsey, Kate E.

    2013-01-01

    No commercial immunodiagnostic tests for human scabies are currently available, and existing animal tests are not sufficiently sensitive. The recombinant Sarcoptes scabiei apolipoprotein antigen Sar s 14.3 is a promising immunodiagnostic, eliciting high levels of IgE and IgG in infected people. Limited data are available regarding the temporal development of antibodies to Sar s 14.3, an issue of relevance in terms of immunodiagnosis. We utilised a porcine model to prospectively compare specific antibody responses to a primary infestation by ELISA, to Sar s 14.3 and to S. scabiei whole mite antigen extract (WMA). Differences in the antibody profile between antigens were apparent, with Sar s 14.3 responses detected earlier, and declining significantly after peak infestation compared to WMA. Both antigens resulted in >90% diagnostic sensitivity from weeks 8–16 post infestation. These data provide important information on the temporal development of humoral immune responses in scabies and further supports the development of recombinant antigen based immunodiagnostic tests for recent scabies infestations. PMID:23762351

  13. Development of Off-pump Mitral Valve Replacement in a Porcine Model

    PubMed Central

    Gillespie, Matthew J.; Aoki, Chikashi; Satoshi, Takebayashi; Shimaoka, Toru; McGarvey, Jeremy R.; Gorman, Robert C.; Gorman, Joseph H.

    2015-01-01

    Purpose We describe our initial experience with on-bypass and off-bypass (off-pump) mitral valve replacement with the modified version of our novel catheter-based sutureless mitral valve (SMV2) technology, which was developed to atraumatically anchor and seal in the mitral position. Description The SMV is a self-expanding device consisting of a custom designed nitinol framework and a pericardial leaflet valve mechanism. For the current studies our original device was modified (SMV2) to reduce the delivery profile and to allow for controlled deployment whilst still maintaining the key principles necessary for atraumatic anchoring and sealing in the MV position. Evaluation Ten Yorkshire pigs underwent successful SMV2 device implantation via a left atriotomy (on-pump N=6; off-pump N=4). Echocardiography and angiography revealed excellent LV systolic function, no significant perivalvular leak, no MV stenosis, no left ventricular (LV) outflow tract obstruction and no aortic valve insufficiency. Necropsy demonstrated that the SMV2 devices were anchored securely. Conclusions This study demonstrates the feasibility and short-term success of off-pump mitral valve replacement using a novel, catheter-based device in a porcine model. PMID:25841820

  14. Adipose tissue remodeling in a novel domestic porcine model of diet-induced obesity

    PubMed Central

    Pawar, Aditya S.; Zhu, Xiang-Yang; Eirin, Alfonso; Tang, Hui; Jordan, Kyra L.; Woollard, John R.; Lerman, Amir; Lerman, Lilach O.

    2014-01-01

    Objective To establish and characterize a novel domestic porcine model of obesity. Design and Methods Fourteen domestic pigs were fed normal (lean, n=7) or high-fat/high-fructose diet (obese, n=7) for 16 weeks. Subcutaneous abdominal adipose tissue biopsies were obtained after 8, 12 and 16 weeks of diet, and pericardial adipose tissue after 16 weeks, for assessments of adipocyte size, fibrosis, and inflammation. Adipose tissue volume and cardiac function were studied with multi-detector computed-tomography, and oxygenation with magnetic resonance imaging. Plasma lipids profiles, insulin resistance, and markers of inflammation were evaluated. Results Compared with lean, obese pigs had elevated cholesterol and triglycerides levels, blood pressure, and insulin resistance. Both abdominal and pericardial fat volume increased after 16 weeks of obese. In abdominal subcutaneous adipose tissue, adipocyte size and both tumor necrosis factor (TNF)-α expression progressively increased. Macrophage infiltration showed in both abdominal and pericardial adipose tissues. Circulating TNF-α increased in obese only at 16 weeks. Compared with Lean, obese pigs had similar global cardiac function, but myocardial perfusion and oxygenation were significantly impaired. Conclusion A high-fat/high-fructose diet induces in domestic pigs many characteristics of metabolic syndrome, which is useful to investigate the effects of the obesity. PMID:25627626

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

    NASA Astrophysics Data System (ADS)

    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%.

  16. A pilot study on ultrasound-assisted liposuction of the greater omentum in porcine models.

    PubMed

    Sumiyama, Kazuki; Utsunomiya, Kazunori; Ohya, Tomohiko; Aihara, Hiroyuki; Ikeda, Keiichi; Imazu, Hiroo; Tamai, Naoto; Nagano, Hiroshi; Ishinoda, Yasuhiro; Tajiri, Hisao

    2012-03-01

    The greater omentum is the largest depot of visceral fat, and recent studies implicate removal of omental fat as a therapeutic option for metabolic syndrome (MS). This study evaluated the technical feasibility of reducing omental fat by using ultrasound-assisted liposuction (UAL) in porcine models. We removed as much omental adipose tissues as possible with a novel ultrasonic aspirator specifically designed for visceral liposuction that was inserted into the peritoneal cavity via the bilateral hypochondrial trocars. The greater part of the omental surface was emulsified and suctioned within 12.4 ± 9.2 (mean ± SD) min. In the survival study, all animals survived for two weeks without clinically evident complications following UAL. Histological examinations confirmed a substantial reduction in omental fat in pigs subjected to UAL. In conclusion, the pilot animal study conducted here demonstrated the technical feasibility of omental liposuction. UAL thus has potential as a relatively non-invasive liposuction approach to treat MS by selectively reducing the visceral fat content of the greater omentum. PMID:21395461

  17. Anti-inflammatory effects of mannanase-hydrolyzed copra meal in a porcine model of colitis.

    PubMed

    Ibuki, Masahisa; Fukui, Kensuke; Kanatani, Hiroyuki; Mine, Yoshinori

    2014-05-01

    We evaluated the anti-inflammatory activity of mannanase-hydrolyzed copra meal (MNB), including β-1,4-mannobiose (67.8%), in a dextran sodium sulfate (DSS)-induced porcine model of intestinal inflammation. In the DSS-positive control (POS) and MNB treatment (MCM) groups, DSS was first administered to piglets via intragastric catheter for 5 days, followed by 5 days administration of saline or MCM. A negative control group (NEG) received a saline alternative to DSS and MNB. Inflammation was assessed by clinical signs, morphological and histological measurements, gut permeability and neutrophil infiltration. Local production of TNF-α and IL-6 were analyzed by ELISA, colonic and ileal inflammatory gene expressions were assessed by real time RT-PCR, and CD4+CD25+ cell populations were analyzed by flow cytometry. Crypt elongation and muscle thickness, D-mannitol gut permeation, colonic expression of the inflammatory mediators TNF-α and IL-6 and myeloperoxidase activity were significantly lower in the MCM group than in that of POS group. The mRNA levels of ileal IL-1β, IL-6, IL-17 and TNF-α were significantly lower following MCM treatment than with POS treatment.MNB exerts anti-inflammatory activity in vivo, suggesting that MNB is a novel therapeutic that may provide relief to human and animals suffering from intestinal inflammation. PMID:24430661

  18. Adenoviral gene transfer corrects the ion transport defect in the sinus epithelia of a porcine CF model.

    PubMed

    Potash, Andrea E; Wallen, Tanner J; Karp, Philip H; Ernst, Sarah; Moninger, Thomas O; Gansemer, Nicholas D; Stoltz, David A; Zabner, Joseph; Chang, Eugene H

    2013-05-01

    Cystic fibrosis (CF) pigs spontaneously develop sinus and lung disease resembling human CF. The CF pig presents a unique opportunity to use gene transfer to test hypotheses to further understand the pathogenesis of CF sinus disease. In this study, we investigated the ion transport defect in the CF sinus and found that CF porcine sinus epithelia lack cyclic AMP (cAMP)-stimulated anion transport. We asked whether we could restore CF transmembrane conductance regulator gene (CFTR) current in the porcine CF sinus epithelia by gene transfer. We quantified CFTR transduction using an adenovirus expressing CFTR and green fluorescent protein (GFP). We found that as little as 7% of transduced cells restored 6% of CFTR current with 17-28% of transduced cells increasing CFTR current to 50% of non-CF levels. We also found that we could overcorrect cAMP-mediated current in non-CF epithelia. Our findings indicate that CF porcine sinus epithelia lack anion transport, and a relatively small number of cells expressing CFTR are required to rescue the ion transport phenotype. These studies support the use of the CF pig as a preclinical model for future gene therapy trials in CF sinusitis. PMID:23511247

  19. Bioartificial Heart: A Human-Sized Porcine Model – The Way Ahead

    PubMed Central

    Weymann, Alexander; Patil, Nikhil Prakash; Sabashnikov, Anton; Jungebluth, Philipp; Korkmaz, Sevil; Li, Shiliang; Veres, Gabor; Soos, Pal; Ishtok, Roland; Chaimow, Nicole; Pätzold, Ines; Czerny, Natalie; Schies, Carsten; Schmack, Bastian; Popov, Aron-Frederik; Simon, André Rüdiger; Karck, Matthias; Szabo, Gabor

    2014-01-01

    Background A bioartificial heart is a theoretical alternative to transplantation or mechanical left ventricular support. Native hearts decellularized with preserved architecture and vasculature may provide an acellular tissue platform for organ regeneration. We sought to develop a tissue-engineered whole-heart neoscaffold in human-sized porcine hearts. Methods We decellularized porcine hearts (n = 10) by coronary perfusion with ionic detergents in a modified Langendorff circuit. We confirmed decellularization by histology, transmission electron microscopy and fluorescence microscopy, quantified residual DNA by spectrophotometry, and evaluated biomechanical stability with ex-vivo left-ventricular pressure/volume studies, all compared to controls. We then mounted the decellularized porcine hearts in a bioreactor and reseeded them with murine neonatal cardiac cells and human umbilical cord derived endothelial cells (HUVEC) under simulated physiological conditions. Results Decellularized hearts lacked intracellular components but retained specific collagen fibers, proteoglycan, elastin and mechanical integrity; quantitative DNA analysis demonstrated a significant reduction of DNA compared to controls (82.6±3.2 ng DNA/mg tissue vs. 473.2±13.4 ng DNA/mg tissue, p<0.05). Recellularized porcine whole-heart neoscaffolds demonstrated re-endothelialization of coronary vasculature and measurable intrinsic myocardial electrical activity at 10 days, with perfused organ culture maintained for up to 3 weeks. Conclusions Human-sized decellularized porcine hearts provide a promising tissue-engineering platform that may lead to future clinical strategies in the treatment of heart failure. PMID:25365554

  20. In vivo porcine lipopolysaccharide inflammation models to study immunomodulation of drugs.

    PubMed

    Wyns, H; Plessers, E; De Backer, P; Meyer, E; Croubels, S

    2015-08-15

    Lipopolysaccharide (LPS), a structural part of the outer membrane of Gram-negative bacteria, is one of the most effective stimulators of the immune system and has been widely applied in pigs as an experimental model for bacterial infection. For this purpose, a variety of Escherichia coli serotypes, LPS doses, routes and duration of administration have been used. LPS administration induces the acute phase response (APR) and is associated with dramatic hemodynamic, clinical and behavioral changes in pigs. Pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α), interleukin (IL)-1 and IL-6 are involved in the induction of the eicosanoid pathway and the hepatic production of acute phase proteins, including C-reactive protein (CRP), haptoglobin (Hp) and pig major acute phase protein (pig-MAP). Prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) play a major role in the development of fever and pulmonary hypertension in LPS-challenged pigs, respectively. The LPS-induced APR can be modulated by drugs. Steroidal and nonsteroidal anti-inflammatory drugs ((N)SAIDs) possess anti-inflammatory, antipyretic and analgesic properties through (non)-selective central and peripheral cyclooxygenase (COX) inhibition. Antimicrobial drugs, especially macrolide antibiotics, which are commonly used in veterinary medicine for the treatment of bacterial respiratory diseases, have been recurrently reported to exert clinically important immunomodulatory effects in human and murine research. To investigate the influence of these drugs on the clinical response, production of pro-inflammatory cytokines, acute phase proteins (APP) and the course of the febrile response in pigs, in vivo LPS inflammation models can be applied. Yet, to date, in vivo research on the immunomodulatory properties of antimicrobial drugs in these models in pigs is largely lacking. This review provides acritical overview of the use of in vivo porcine E. coli LPS inflammation models for the study of the APR, as

  1. Feasibility of 68Ga-labeled Siglec-9 peptide for the imaging of acute lung inflammation: a pilot study in a porcine model of acute respiratory distress syndrome

    PubMed Central

    Retamal, Jaime; Sörensen, Jens; Lubberink, Mark; Suarez-Sipmann, Fernando; Borges, João Batista; Feinstein, Ricardo; Jalkanen, Sirpa; Antoni, Gunnar; Hedenstierna, Göran; Roivainen, Anne; Larsson, Anders; Velikyan, Irina

    2016-01-01

    There is an unmet need for noninvasive, specific and quantitative imaging of inherent inflammatory activity. Vascular adhesion protein-1 (VAP-1) translocates to the luminal surface of endothelial cells upon inflammatory challenge. We hypothesized that in a porcine model of acute respiratory distress syndrome (ARDS), positron emission tomography (PET) with sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9) based imaging agent targeting VAP-1 would allow quantification of regional pulmonary inflammation. ARDS was induced by lung lavages and injurious mechanical ventilation. Hemodynamics, respiratory system compliance (Crs) and blood gases were monitored. Dynamic examination using [15O]water PET-CT (10 min) was followed by dynamic (90 min) and whole-body examination using VAP-1 targeting 68Ga-labeled 1,4,7,10-tetraaza cyclododecane-1,4,7-tris-acetic acid-10-ethylene glycol-conjugated Siglec-9 motif peptide ([68Ga]Ga-DOTA-Siglec-9). The animals received an anti-VAP-1 antibody for post-mortem immunohistochemistry assay of VAP-1 receptors. Tissue samples were collected post-mortem for the radioactivity uptake, histology and immunohistochemistry assessment. Marked reduction of oxygenation and Crs, and higher degree of inflammation were observed in ARDS animals. [68Ga]Ga-DOTA-Siglec-9 PET showed significant uptake in lungs, kidneys and urinary bladder. Normalization of the net uptake rate (Ki) for the tissue perfusion resulted in 4-fold higher uptake rate of [68Ga]Ga-DOTA-Siglec-9 in the ARDS lungs. Immunohistochemistry showed positive VAP-1 signal in the injured lungs. Detection of pulmonary inflammation associated with a porcine model of ARDS was possible with [68Ga]Ga-DOTA-Siglec-9 PET when using kinetic modeling and normalization for tissue perfusion. PMID:27069763

  2. Feasibility of (68)Ga-labeled Siglec-9 peptide for the imaging of acute lung inflammation: a pilot study in a porcine model of acute respiratory distress syndrome.

    PubMed

    Retamal, Jaime; Sörensen, Jens; Lubberink, Mark; Suarez-Sipmann, Fernando; Borges, João Batista; Feinstein, Ricardo; Jalkanen, Sirpa; Antoni, Gunnar; Hedenstierna, Göran; Roivainen, Anne; Larsson, Anders; Velikyan, Irina

    2016-01-01

    There is an unmet need for noninvasive, specific and quantitative imaging of inherent inflammatory activity. Vascular adhesion protein-1 (VAP-1) translocates to the luminal surface of endothelial cells upon inflammatory challenge. We hypothesized that in a porcine model of acute respiratory distress syndrome (ARDS), positron emission tomography (PET) with sialic acid-binding immunoglobulin-like lectin 9 (Siglec-9) based imaging agent targeting VAP-1 would allow quantification of regional pulmonary inflammation. ARDS was induced by lung lavages and injurious mechanical ventilation. Hemodynamics, respiratory system compliance (Crs) and blood gases were monitored. Dynamic examination using [(15)O]water PET-CT (10 min) was followed by dynamic (90 min) and whole-body examination using VAP-1 targeting (68)Ga-labeled 1,4,7,10-tetraaza cyclododecane-1,4,7-tris-acetic acid-10-ethylene glycol-conjugated Siglec-9 motif peptide ([(68)Ga]Ga-DOTA-Siglec-9). The animals received an anti-VAP-1 antibody for post-mortem immunohistochemistry assay of VAP-1 receptors. Tissue samples were collected post-mortem for the radioactivity uptake, histology and immunohistochemistry assessment. Marked reduction of oxygenation and Crs, and higher degree of inflammation were observed in ARDS animals. [(68)Ga]Ga-DOTA-Siglec-9 PET showed significant uptake in lungs, kidneys and urinary bladder. Normalization of the net uptake rate (Ki) for the tissue perfusion resulted in 4-fold higher uptake rate of [(68)Ga]Ga-DOTA-Siglec-9 in the ARDS lungs. Immunohistochemistry showed positive VAP-1 signal in the injured lungs. Detection of pulmonary inflammation associated with a porcine model of ARDS was possible with [(68)Ga]Ga-DOTA-Siglec-9 PET when using kinetic modeling and normalization for tissue perfusion. PMID:27069763

  3. Invasive surgery reduces infarct size and preserves cardiac function in a porcine model of myocardial infarction

    PubMed Central

    van Hout, Gerardus PJ; Teuben, Michel PJ; Heeres, Marjolein; de Maat, Steven; de Jong, Renate; Maas, Coen; Kouwenberg, Lisanne HJA; Koenderman, Leo; van Solinge, Wouter W; de Jager, Saskia CA; Pasterkamp, Gerard; Hoefer, Imo E

    2015-01-01

    Reperfusion injury following myocardial infarction (MI) increases infarct size (IS) and deteriorates cardiac function. Cardioprotective strategies in large animal MI models often failed in clinical trials, suggesting translational failure. Experimentally, MI is induced artificially and the effect of the experimental procedures may influence outcome and thus clinical applicability. The aim of this study was to investigate if invasive surgery, as in the common open chest MI model affects IS and cardiac function. Twenty female landrace pigs were subjected to MI by transluminal balloon occlusion. In 10 of 20 pigs, balloon occlusion was preceded by invasive surgery (medial sternotomy). After 72 hrs, pigs were subjected to echocardiography and Evans blue/triphenyl tetrazoliumchloride double staining to determine IS and area at risk. Quantification of IS showed a significant IS reduction in the open chest group compared to the closed chest group (IS versus area at risk: 50.9 ± 5.4% versus 69.9 ± 3.4%, P = 0.007). End systolic LV volume and LV ejection fraction measured by echocardiography at follow-up differed significantly between both groups (51 ± 5 ml versus 65 ± 3 ml, P = 0.033; 47.5 ± 2.6% versus 38.8 ± 1.2%, P = 0.005). The inflammatory response in the damaged myocardium did not differ between groups. This study indicates that invasive surgery reduces IS and preserves cardiac function in a porcine MI model. Future studies need to elucidate the effect of infarct induction technique on the efficacy of pharmacological therapies in large animal cardioprotection studies. PMID:26282710

  4. Virtual Electrophysiologic Study in a Three-dimensional Cardiac MRI Model of Porcine Myocardial Infarction

    PubMed Central

    Ng, Jason; Jacobson, Jason T; Ng, Justin K; Gordon, David; Lee, Daniel C; Carr, James C.; Goldberger, Jeffrey J

    2012-01-01

    Objective This study sought to test the hypothesis that “virtual” electrophysiologic studies (EPS) on an anatomic platform generated by 3D MRI reconstruction of the left ventricle (LV) can reproduce the reentrant circuits of induced ventricular tachycardia (VT) in a porcine model of myocardial infarction (MI). Background Delayed-enhancement MRI has been used to characterize MI and “gray zones”, which are thought to reflect heterogeneous regions of viable and non-viable myocytes. Methods MI by coronary artery occlusion was induced in eight pigs. After a recovery period, 3D cardiac MRIs were obtained from each pig in-vivo. Normal areas, gray zones, and infarct cores were classified based on voxel intensity. In the computer model, gray zones were assigned slower conduction and longer action potential durations than those for normal myocardium. Virtual EPS was performed and was compared to results of actual in vivo programmed stimulation and non-contact mapping. Results The LV volumes ranged from 97.8 to 166.2 cm3 with 4.9 to 17.5% of voxels classified as infarct zones. Six of the seven pigs that developed VT during actual EPS were also inducible with virtual EPS. Four of the six pigs that had simulated VT had reentrant circuits that approximated the circuits seen with non-contact mapping, while the remaining two had similar circuits but propagating in opposite directions. Conclusions This initial study demonstrates the feasibility of applying a mathematical model to MRI reconstructions of the LV to predict VT circuits. Virtual EPS may be helpful to plan catheter ablation strategies or to identify patients who are at risk for future episodes of VT. PMID:22633654

  5. Development of a Bronchial Wall Model: Triple Culture on a Decellularized Porcine Trachea.

    PubMed

    Melo, Esther; Kasper, Jennifer Y; Unger, Ronald E; Farré, Ramon; Kirkpatrick, Charles James

    2015-09-01

    In vitro coculture models mimicking the bronchial barrier are a significant step forward in investigating the behavior and function of the upper respiratory tract mucosa. To date, mostly synthetic materials have been used as substrates to culture the cells. However, decellularized tissues provide a more in vivo-like environment based on the native extracellular matrix. In this study, an in vitro, bronchial wall coculture model has been established using a decellularized, porcine luminal trachea membrane and employing three relevant human cell types. The tissue was decellularized and placed in plastic transwell supports. The human bronchial epithelial cell line, 16HBE14o-, was seeded on the apical side of the membrane with the human lung fibroblast cell line, Wi-38, and/or the microvascular endothelial cell line, ISO-HAS-1, seeded on the basolateral side. Transepithelial electrical resistance (TER) was measured over 10 days and tight/adherens junctions (ZO-1, occludin/β-catenin) were studied through immunofluorescence. Scanning electron microscopy (SEM) was performed to evaluate microvilli and cilia formation. All cultures grew successfully on the membrane. TER values of 555 Ω·cm(2) (±21, SEM) were achieved in the monoculture. Cocultures with fibroblasts reached 565 Ω·cm(2) (±41, SEM), with endothelial cells at 638 Ω·cm(2) (±37, SEM), and the triple culture achieved 552 Ω·cm(2) (±38, SEM). ZO-1, occludin, and β-catenin were expressed in 16HBE14o- under all culture conditions. Using SEM, a dense microvilli population was found. Prominent cell-cell contacts and clusters of emerging cilia could be identified. Fibroblasts and endothelial cells strengthened the formation of a tight barrier by the 16HBE14o-. Thus, the coculture of three relevant cell types in combination with native decellularized scaffolds as a substrate approaches more closely the in vivo situation and could be used to study mechanisms of upper respiratory damage and regeneration. PMID

  6. Cholesteryl esters accumulate in the heart in a porcine model of ischemia and reperfusion.

    PubMed

    Drevinge, Christina; Karlsson, Lars O; Ståhlman, Marcus; Larsson, Thomas; Perman Sundelin, Jeanna; Grip, Lars; Andersson, Linda; Borén, Jan; Levin, Malin C

    2013-01-01

    Myocardial ischemia is associated with intracellular accumulation of lipids and increased depots of myocardial lipids are linked to decreased heart function. Despite investigations in cell culture and animal models, there is little data available on where in the heart the lipids accumulate after myocardial ischemia and which lipid species that accumulate. The aim of this study was to investigate derangements of lipid metabolism that are associated with myocardial ischemia in a porcine model of ischemia and reperfusion. The large pig heart enables the separation of the infarct area with irreversible injury from the area at risk with reversible injury and the unaffected control area. The surviving myocardium bordering the infarct is exposed to mild ischemia and is stressed, but remains viable. We found that cholesteryl esters accumulated in the infarct area as well as in the bordering myocardium. In addition, we found that expression of the low density lipoprotein receptor (LDLr) and the low density lipoprotein receptor-related protein 1 (LRP1) was up-regulated, suggesting that choleteryl ester uptake is mediated via these receptors. Furthermore, we found increased ceramide accumulation, inflammation and endoplasmatic reticulum (ER) stress in the infarcted area of the pig heart. In addition, we found increased levels of inflammation and ER stress in the myocardium bordering the infarct area. Our results indicate that lipid accumulation in the heart is one of the metabolic derangements remaining after ischemia, even in the myocardium bordering the infarct area. Normalizing lipid levels in the myocardium after ischemia would likely improve myocardial function and should therefore be considered as a target for treatment. PMID:23637933

  7. Remote Ischemic Preconditioning Reduces Cerebral Oxidative Stress Following Hypothermic Circulatory Arrest in a Porcine Model.

    PubMed

    Arvola, Oiva; Haapanen, Henri; Herajärvi, Johanna; Anttila, Tuomas; Puistola, Ulla; Karihtala, Peeter; Tuominen, Hannu; Anttila, Vesa; Juvonen, Tatu

    2016-01-01

    Remote ischemic precondition has become prominent as one of the most promising methods to mitigate neurological damage following ischemic insult. The purpose of this study was to investigate whether the effects of remote ischemic preconditioning can be seen in the markers of oxidative stress or in redox-regulating enzymes in a porcine model. A total of 12 female piglets were randomly assigned to 2 groups. The study group underwent an intervention of 4 cycles of 5-minute ischemic preconditioning on the right hind leg. All piglets underwent 60-minute hypothermic circulatory arrest. Oxidative stress marker 8-hydroxydeoxyguanosine (8-OHdG) was measured from blood samples with enzyme-linked immunosorbent assay. After 7 days of follow-up, samples from the brain, heart, kidney, and ovary were harvested for histopathologic examination. The immunohistochemical stainings of hypoxia marker hypoxia-inducible factor-1-α, oxidative stress marker 8-OHdG, DNA repair enzyme 8-oxoguanine glycosylase, and antioxidant response regulators nuclear factor erythroid 2-related factor 2 and protein deglycase were analyzed. The level of 8-OHdG referred to baseline was decreased in the sagittal sinus׳ blood samples in the study group after a prolonged deep hypothermic circulatory arrest at 360 minutes after reperfusion. Total histopathologic score was 3.8 (1.8-6.0) in the study group and was 4.4 (2.5-6.5) in the control group (P = 0.72), demonstrating no statistically significant difference in cerebral injury. Our findings demonstrate that the positive effects of remote ischemic preconditioning can be seen in cellular oxidative balance regulators in an animal model after 7 days of preconditioned ischemic insult. PMID:27568144

  8. Sclera-Choroid-RPE Transport of Eight β-Blockers in Human, Bovine, Porcine, Rabbit, and Rat Models

    PubMed Central

    Kadam, Rajendra S.; Cheruvu, Narayan P. S.; Edelhauser, Henry F.

    2011-01-01

    Purpose. To determine the influence of drug lipophilicity, ocular pigmentation, and species differences on transscleral solute transport. Methods. The transport of eight β-blockers across excised sclera/sclera-choroid-RPE (SCRPE) of albino rabbit, pigmented rabbit, human, porcine, and bovine eyes was determined over 6 hours. The ex vivo transscleral β-blocker transport to the vitreous at the end of 6 hours was determined in euthanatized, pigmented Brown Norway rats. The thicknesses of the sclera and SCRPE and the melanin content in choroid-RPE (CRPE) were measured to determine whether species differences in drug transport can be explained on this basis. Results. Solute lipophilicity inversely correlated with the SCRPE cumulative percentage of transport in all species (R2 ≥ 0.80). The CRPE impeded the SCRPE transport of all β-blockers (51%–64% resistance in the rabbits; 84%–99.8% in the bovine and porcine eyes) more than the sclera, with the impedance increasing with lipophilicity. SCRPE transport followed the trend albino rabbit > pigmented rabbit > human > porcine > bovine, and a cross-species comparison showed good Spearman's rho correlation (R2 ≥ 0.85). Bovine (R2 = 0.84), porcine (R2 = 0.84), and human (R2 = 0.71) SCRPE transport was more predictive than that in the rabbit models (R2 = 0.60–0.61) of transscleral solute transport to the vitreous in rats. The CRPE concentrations were higher in pigmented rabbits than in albino rabbits. The melanin content of the CRPE exhibited the trend albino rabbit ≪ pigmented rabbit < porcine ∼ bovine < rat. Normalization to scleral thickness abolished the species differences in scleral transport. Normalization to SCRPE thickness and melanin content significantly reduced species differences in SCRPE transport. Conclusions. Owing to the presence of pigment and drug binding, choroid-RPE is the principal barrier to transscleral β-blocker transport, with the barrier being more significant for lipophilic

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Carbon dioxide laser ablation with immediate autografting in a full-thickness porcine burn model.

    PubMed Central

    Glatter, R D; Goldberg, J S; Schomacker, K T; Compton, C C; Flotte, T J; Bua, D P; Greaves, K W; Nishioka, N S; Sheridan, R L

    1998-01-01

    OBJECTIVE: To compare the long-term clinical and histologic outcome of immediate autografting of full-thickness burn wounds ablated with a high-power continuous-wave CO2 laser to sharply débrided wounds in a porcine model. SUMMARY BACKGROUND DATA: Continuous-wave CO2 lasers have performed poorly as tools for burn excision because the large amount of thermal damage to viable subeschar tissues precluded successful autografting. However, a new technique, in which a high-power laser is rapidly scanned over the eschar, results in eschar vaporization without significant damage to underlying viable tissues, allowing successful immediate autografting. METHODS: Full-thickness paravertebral burn wounds measuring 36 cm2 were created on 11 farm swine. Wounds were ablated to adipose tissue 48 hours later using either a surgical blade or a 150-Watt continuous-wave CO2 laser deflected by an x-y galvanometric scanner that translated the beam over the tissue surface, removing 200 microm of tissue per scan. Both sites were immediately autografted and serially evaluated clinically and histologically for 180 days. RESULTS: The laser-treated sites were nearly bloodless. The mean residual thermal damage was 0.18+/-0.05 mm. The mean graft take was 96+/-11% in manual sites and 93+/-8% in laser sites. On postoperative day 7, the thickness of granulation tissue at the graft-wound bed interface was greater in laser-debrided sites. By postoperative day 180, the manual and laser sites were histologically identical. Vancouver scar assessment revealed no differences in scarring at postoperative day 180. CONCLUSIONS: Long-term scarring, based on Vancouver scar assessments and histologic evaluation, was equivalent at 6 months in laser-ablated and sharply excised sites. Should this technology become practical, the potential clinical implications include a reduction in surgical blood loss without sacrifice of immediate engraftment rates or long-term outcome. Images Figure 1. Figure 2. Figure 3

  11. Laparoendoscopic single-site simple nephrectomy using a magnetic anchoring system in a porcine model

    PubMed Central

    Choi, Young Hyo; Lee, Hye Won; Lee, Seo Yeon; Han, Deok Hyun; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han Yong

    2016-01-01

    Purpose Magnetic anchoring devices may reduce the number of port sites needed in laparoscopic surgery. In this study, we prospectively assessed the feasibility of using a magnetic anchoring and guidance system (MAGS) in laparoendoscopic single-site (LESS) surgery performed by novices. Materials and Methods A total of 10 LESS simple nephrectomies were performed with or without MAGS in a nonsurvival porcine model by 6 operators with no previous LESS surgery experience. After installation of the homemade single port, an intra-abdominal magnet was fixed to the renal parenchyma with suturing and stabilized by an external magnet placed on the flank so that the position of the kidney could be easily changed by moving the external handheld magnet. The length of the procedure and any intraoperative complications were evaluated. Results Operative time (mean±standard deviation) was shorter in the group using the magnetic anchoring device (M-LESS-N) than in the group with conventional LESS nephrectomy (C-LESS-N) (63±20.8 minutes vs. 82±40.7 minutes, respectively). Although all nephrectomies were completed uneventfully in the M-LESS-N group, renal vein injury occurred during dissection of the renal hilum in two cases of C-LESS-N and was resolved by simultaneous transection of the renal artery and vein with an Endo-GIA stapler. Conclusions LESS-N using MAGS is a feasible technique for surgeons with no LESS surgery experience. Taking into account the 2 cases of renal vein injury in the C-LESS-N group, the application of MAGS may be beneficial for overcoming the learning curve of LESS surgery. PMID:27195320

  12. Efficacy of Trypsin in Treating Coral Snake Envenomation in the Porcine Model.

    PubMed

    Parker-Cote, Jennifer L; O'Rourke, Dorcas P; Brewer, Kori L; Lertpiriyapong, Kvin; Punja, Mohan; Bush, Sean P; Miller, Susan N; Meggs, William J

    2015-12-01

    Antivenom is the definitive treatment for venomous snakebites. Alternative treatments warrant investigation because antivenom is sometimes unavailable, expensive, and can have deleterious side effects. This study assesses the efficacy of trypsin to treat coral snake envenomation in an in vivo porcine model. A randomized, blinded study was conducted. Subjects were 13 pigs injected subcutaneously with 1 mL of eastern coral snake venom (10 mg/mL) in the right distal hind limb. After 1 min, subjects were randomized to have the envenomation site injected with either 1 mL of saline or 1 mL of trypsin (100 mg/mL) by a blinded investigator. Clinical endpoint was survival for 72 h or respiratory depression defined as respiratory rate <15 breaths per minute, falling pulse oximetry, or agonal respirations. Fisher's exact t test was used for between group comparisons. Average time to toxicity for the saline control was 263 min (191-305 min). The development of respiratory depression occurred more frequently in control pigs than treated pigs (p = 0.009). Four of the six pigs that received trypsin survived to the end of the 3-day study. No control pigs survived. Two of the trypsin treatment pigs died with times to toxicity of 718 and 971 min. Survival to 12 and 24 h was significantly greater in the trypsin treatment group (p = 0.002, p = 0.009, respectively). Local injection of trypsin, a proteolytic enzyme, at the site of envenomation decreased the toxicity of eastern coral snake venom and increased survival significantly. Further investigation is required before these results can be extended to human snakebites. PMID:25952763

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

    SciTech Connect

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

    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.

  14. Donor site healing dynamics: molecular, histological, and noninvasive imaging assessment in a porcine model.

    PubMed

    Mauskar, Neil A; Sood, Subeena; Travis, Taryn E; Matt, Sarah E; Mino, Matthew J; Burnett, Mary-Susan; Moffatt, Lauren T; Fidler, Philip; Epstein, Stephen E; Jordan, Marion H; Shupp, Jeffrey W

    2013-01-01

    Understanding the physiology of donor site healing will lead to advances in how these wounds are treated and may ultimately allow faster healing, more frequent autografting, and more effective care of the burn-injured patient. Unfortunately, a paucity of data exists regarding perfusion metrics over the course of donor site healing. Furthermore, there are no studies that interrelate indices of perfusion with the molecular and cellular processes of donor site healing. Male Duroc pigs were anesthetized and donor site wounds were created using a Zimmer dermatome at a depth of 0.060 inch (1.52 mm). Digital photographs, laser Doppler images, and punch biopsies were obtained before and after excision and on days 2, 4, 7, 9, 11, 14, and 16 until wounds were healed. RNA isolation was performed and quantitative polymerase chain reaction was used to examine differential gene expression over the time course. Formalin-fixed biopsies were embedded in paraffin, sectioned, stained, and examined. Wound surfaces were 83% re-epithelialized by day 16. Perfusion peaked on day 2 then declined, but it remained significantly elevated compared to before excision (P < .05). From day 9 onward, mean perfusion units were not significantly different from baseline (P < .05). Twenty-two representative genes were selected for examination. RNA expression of collagen, tenascin-cytoactin, inflammatory cytokines, remodeling enzymes, growth factors, and Wnt was increased. Inflammatory cells and cytokines were demonstrated histologically. Nuclei per high powered field peaked at day 7 and neodermal thickness increased daily to day 14. A novel porcine model for donor site wound healing that interrelates re-epithelilaizationand perfusion with molecular and cellular indices has been demonstrated. PMID:23511287

  15. Experimental laparoscopic and thoracoscopic discectomy and instrumented spinal fusion. A feasibility study using a porcine model.

    PubMed

    Mühlbauer, M; Ferguson, J; Losert, U; Koos, W T

    1998-03-01

    To explore the safety and the effectiveness of laparoscopic and thoracoscopic spinal surgery, an acute/non-survival animal trial was performed in 5 pigs using rigid and flexible endoscopes, flouroscopy, a holmium-YAG laser, and prototype instruments and implants. Our study aimed to approach the intervertebral disc space and spinal canal using laparoscopic and thoracoscopic techniques and to explore the potential and limits for endoscopic anterior spinal decompression and fusion. In a lateral recumbency access was provided to the anterolateral aspect of the lumbar spine from L1/2 to L7/S1, the thoracic spine was accessible from T2/3 to the diaphragmatic insertion. Complete disc space emptying with penetration into the spinal canal could be performed, epidural bleeding could be controlled by a hemostatic sponge, however bleeding restricted visualization for further endoscopic manipulation in the spinal canal. Intervertebral fusion was accomplished at T6/7, L4/5 and L7/S1 using small fragment plates with 3.5 mm screws and iliac bone grafts or prototype carbon fiber cages. On post mortem examination we found no dural tears and no nerve root damage, all animals had stabilized fusion sites and good implant position. We conclude that minimally invasive thoracoscopic and laparoscopic approaches to the spine are feasible and safe to perform disc decompression and implant placement for spinal fusion. In addition to currently performed laparoscopic interbody fusion, also plate fixation to reestablish lordosis of the lumbar spine is feasible at least in the porcine model. Careful disc decompression must be performed prior to implant introduction to prevent iatrogenic disc protrusion and spinal cord or nerve root compression. However, further surgical exploration of the spinal canal using these techniques does not provide adequate visualization of epidural spaces and therefore must be regarded as unsafe. PMID:9565956

  16. Low-shear modelled microgravity environment maintains morphology and differentiated functionality of primary porcine hepatocyte cultures.

    PubMed

    Nelson, Leonard J; Walker, Simon W; Hayes, Peter C; Plevris, John N

    2010-01-01

    Hepatocytes cultured in conventional static culture rapidly lose polarity and differentiated function. This could be explained by gravity-induced sedimentation, which prevents formation of complete three-dimensional (3D) cell-cell/cell-matrix interactions and disrupts integrin-mediated signals (including the most abundant hepatic integrin alpha(5)beta(1)), important for cellular polarity and differentiation. Cell culture in a low fluid shear modelled microgravity (about 10(-2) g) environment promotes spatial colocation/self-aggregation of dissociated cells and induction of 3D differentiated liver morphology. Previously, we demonstrated the utility of a NASA rotary bioreactor in maintaining key metabolic functions and 3D aggregate formation of high-density primary porcine hepatocyte cultures over 21 days. Using serum-free chemically defined medium, without confounding interactions of exogenous bioscaffolding or bioenhancing surface materials, we investigated features of hepatic cellular polarity and differentiated functionality, including expression of hepatic integrin alpha(5), as markers of functional morphology. We report here that in the absence of exogenous biomatrix scaffolding, hepatocytes cultured in serum-free chemically defined medium in a microgravity environment rapidly (<24 h) form macroscopic (2-5 mm), compacted 3D hepatospheroid structures consisting of a shell of glycogen-positive viable cells circumscribing a core of eosinophilic cells. The spheroid shell layers exhibited ultrastructural, morphological and functional features of differentiated, polarized hepatic tissue including strong expression of the integrin alpha(5) subunit, functional bile canaliculi, albumin synthesis, and fine ultrastructure reminiscent of in vivo hepatic tissue. The low fluid shear microgravity environment may promote tissue-like self-organization of dissociated cells, and offer advantages over spheroids cultured in conventional formats to delineate optimal conditions for

  17. PET Imaging of Serotonin Transporters With 4-[(18)F]-ADAM in a Parkinsonian Rat Model With Porcine Neural Xenografts.

    PubMed

    Chiu, Chuang-Hsin; Li, I-Hsun; Weng, Shao-Ju; Huang, Yuahn-Sieh; Wu, Shinn-Chih; Chou, Ta-Kai; Huang, Wen-Sheng; Liao, Mei-Hsiu; Shiue, Chyng-Yann; Cheng, Cheng-Yi; Ma, Kuo-Hsing

    2016-01-01

    Parkinson's disease (PD) is a neurodegenerative disease characterized by a loss of dopaminergic neurons in the nigrostriatal pathway. Apart from effective strategies to halt the underlying neuronal degeneration, cell replacement now offers novel prospects for PD therapy. Porcine embryonic neural tissue has been considered an alternative source to human fetal grafts in neurodegenerative disorders because its use avoids major practical and ethical issues. This study was undertaken to evaluate the effects of embryonic day 27 (E27) porcine mesencephalic tissue transplantation in a PD rat model using animal positron emission tomography (PET) coupled with 4-[(18)F]-ADAM, a serotonin transporter (SERT) imaging agent. The parkinsonian rat was induced by injecting 6-hydroxydopamine into the medial forebrain bundle (MFB) of the right nigrostriatal pathway. The apomorphine-induced rotation behavioral test and 4-[(18)F]-ADAM/animal PET scanning were carried out following 6-OHDA lesioning. At the second week following 6-OHDA lesioning, the parkinsonian rat rotates substantially on apomorphine-induced contralateral turning. In addition, the mean striatal-specific uptake ratio (SUR) of 4-[(18)F]-ADAM decreased by 44%. After transplantation, the number of drug-induced rotations decreased markedly, and the mean SUR of 4-[(18)F]-ADAM and the level of SERT immunoreactivity (SERT-ir) in striatum were partially restored. The mean SUR level was restored to 71% compared to that for the contralateral intact side, which together with the abundant survival of tyrosine hydroxylase (TH) neurons accounted for functional recovery at the fourth week postgraft. In regard to the extent of donor-derived cells, we found the neurons of the xenografts from E27 transgenic pigs harboring red fluorescent protein (RFP) localized with TH-ir cells and SERT-ir in the grafted area. Thus, transplanted E27 porcine mesencephalic tissue may restore dopaminergic and serotonergic systems in the parkinsonian rat

  18. Clot retraction affects the extent of ultrasound-enhanced thrombolysis in an ex vivo porcine thrombosis model

    PubMed Central

    Sutton, Jonathan T.; Ivancevich, Nikolas M.; Perrin, Stephen R.; Vela, Deborah C.; Holland, Christy K.

    2013-01-01

    Using an FDA-approved contrast agent (Definity®) and thrombolytic drug (rt-PA), we investigated ultrasound-enhanced thrombolysis in two whole-blood clot models. Porcine venous blood was collected from donor hogs and coagulated in two different materials. This method produced clots with differing compositional properties, as determined by routine scanning electron microscopy and histology. Clots were deployed in an ex vivo porcine thrombolysis model, while an intermittent ultrasound scheme previously developed to maximize stable cavitation was applied and acoustic emissions were detected. Exposure of clots to 3.15 μg/mL rt-PA promoted lysis in both clot models, compared to exposure to plasma alone. However, in the presence of rt-PA, Definity®, and ultrasound, only unretracted clots experienced significant enhancement of thrombolysis compared to treatment with rt-PA. In these clots, microscopy studies revealed loose erythrocyte aggregates, a significantly less extensive fibrin network, and a higher porosity, which may facilitate increase penetration of thrombolytics by cavitation. PMID:23453629

  19. First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 5: recipient monitoring and response plan for preventing disease transmission.

    PubMed

    Denner, Joachim; Tönjes, Ralf R; Takeuchi, Yasu; Fishman, Jay; Scobie, Linda

    2016-01-01

    Xenotransplantation of porcine cells, tissues, and organs may be associated with the transmission of porcine microorganisms to the human recipient. A previous, 2009, version of this consensus statement focused on strategies to prevent transmission of porcine endogenous retroviruses (PERVs). This version addresses potential transmission of all porcine microorganisms including monitoring of the recipient and provides suggested approaches to the monitoring and prevention of disease transmission. Prior analyses assumed that most microorganisms other than the endogenous retroviruses could be eliminated from donor animals under appropriate conditions which have been called "designated pathogen-free" (DPF) source animal production. PERVs integrated as proviruses in the genome of all pigs cannot be eliminated in that manner and represent a unique risk. Certain microorganisms are by nature difficult to eliminate even under DPF conditions; any such clinically relevant microorganisms should be included in pig screening programs. With the use of porcine islets in clinical trials, special consideration has to be given to the presence of microorganisms in the isolated islet tissue to be used and also to the potential use of encapsulation. It is proposed that microorganisms absent in the donor animals by sensitive microbiological examination do not need to be monitored in the transplant recipient; this will reduce costs and screening requirements. Valid detection assays for donor and manufacturing-derived microorganisms must be established. Special consideration is needed to preempt potential unknown pathogens which may pose a risk to the recipient. This statement summarizes the main achievements in the field since 2009 and focus on issues and solutions with microorganisms other than PERV. PMID:26918415

  20. Renoprotective Mechanism of Remote Ischemic Preconditioning Based on Transcriptomic Analysis in a Porcine Renal Ischemia Reperfusion Injury Model

    PubMed Central

    Kim, Sook Young; Cho, Young In; Lee, Kwang Suk; Kim, Kwang Hyun; Yang, Seung Choul; Han, Woong Kyu

    2015-01-01

    Ischemic preconditioning (IPC) is a well-known phenomenon in which tissues are exposed to a brief period of ischemia prior to a longer ischemic event. This technique produces tissue tolerance to ischemia reperfusion injury (IRI). Currently, IPC’s mechanism of action is poorly understood. Using a porcine single kidney model, we performed remote IPC with renal IRI and evaluated the IPC mechanism of action. Following left nephrectomy, 15 female Yorkshire pigs were divided into three groups: no IPC and 90 minutes of warm ischemia (control), remote IPC immediately followed by 90 minutes of warm ischemia (rIPCe), and remote IPC with 90 minutes of warm ischemia performed 24 hours later (rIPCl). Differential gene expression analysis was performed using a porcine-specific microarray. The microarray analysis of porcine renal tissues identified 1,053 differentially expressed probes in preconditioned pigs. Among these, 179 genes had altered expression in both the rIPCe and rIPCl groups. The genes were largely related to oxidation reduction, apoptosis, and inflammatory response. In the rIPCl group, an additional 848 genes had altered expression levels. These genes were primarily related to immune response and inflammation, including those coding for cytokines and cytokine receptors and those that play roles in the complement system and coagulation cascade. In the complement system, the membrane attack complex was determined to be sublytic, because it colocalized with phosphorylated extracellular signal-regulated kinase. Furthermore, alpha 2 macroglobulin, tissue plasminogen activator, uterine plasmin trypsin inhibitor, and arginase-1 mRNA levels were elevated in the rIPCl group. These findings indicate that remote IPC produces renoprotective effects through multiple mechanisms, and these effects develop over a long timeframe rather than immediately following IPC. PMID:26489007

  1. Geophysical Model Applications for Monitoring

    SciTech Connect

    Pasyanos, M; Walter, W; Tkalcic, H; Franz, G; Gok, R; Rodgers, A

    2005-07-11

    Geophysical models constitute an important component of calibration for nuclear explosion monitoring. We will focus on four major topics and their applications: (1) surface wave models, (2) receiver function profiles, (3) regional tomography models, and (4) stochastic geophysical models. First, we continue to improve upon our surface wave model by adding more paths. This has allowed us to expand the region to all of Eurasia and into Africa, increase the resolution of our model, and extend results to even shorter periods (7 sec). High-resolution models exist for the Middle East and the YSKP region. The surface wave results can be inverted either alone, or in conjunction with other data, to derive models of the crust and upper mantle structure. One application of the group velocities is to construct phase-matched filters in combination with regional surface-wave magnitude formulas to improve the mb:Ms discriminant and extend it to smaller magnitude events. Next, we are using receiver functions, in joint inversions with the surface waves, to produce profiles directly under seismic stations throughout the region. In the past year, we have been focusing on deployments throughout the Middle East, including the Arabian Peninsula and Turkey. By assembling the results from many stations, we can see how regional seismic phases are affected by complicated upper mantle structure, including lithospheric thickness and anisotropy. The next geophysical model item, regional tomography models, can be used to predict regional travel times such as Pn and Sn. The times derived by the models can be used as a background model for empirical measurements or, where these don't exist, simply used as is. Finally, we have been exploring methodologies such as Markov Chain Monte Carlo (MCMC) to generate data-driven stochastic models. We have applied this technique to the YSKP region using surface wave dispersion data, body wave travel time data, receiver functions, and gravity data. The models

  2. Evaluation of a minimally invasive renal cooling device using heat transfer analysis and an in vivo porcine model.

    PubMed

    Cervantes, Thomas M; Summers, Edward K; Batzer, Rachel; Simpson, Christie; Lewis, Raymond; Dhanani, Nadeem N; Slocum, Alexander H

    2013-06-01

    Partial nephrectomy is the gold standard treatment for renal cell carcinoma. This procedure requires temporary occlusion of the renal artery, which can cause irreversible damage due to warm ischemia after 30 min. Open surgical procedures use crushed ice to induce a mild hypothermia of 20°C in the kidney, which can increase allowable ischemia time up to 2.5 h. The Kidney Cooler device was developed previously by the authors to achieve renal cooling using a minimally invasive approach. In the present study an analytical model of kidney cooling in situ was developed using heat transfer equations to determine the effect of kidney thickness on cooling time. In vivo porcine testing was conducted to evaluate the cooling performance of this device and to identify opportunities for improved surgical handling. Renal temperature was measured continuously at 6 points using probes placed orthogonally to each other within the kidney. Results showed that the device can cool the core of the kidney to 20°C in 10-20 min. Design enhancements were made based on surgeon feedback; it was determined that the addition of an insulating air layer below the device increased difficulty of positioning the device around the kidney and did not significantly enhance cooling performance. The Kidney Cooler has been shown to effectively induce mild renal hypothermia of 20°C in an in vivo porcine model. PMID:22951039

  3. Paracrine Factors from Irradiated Peripheral Blood Mononuclear Cells Improve Skin Regeneration and Angiogenesis in a Porcine Burn Model

    PubMed Central

    Hacker, Stefan; Mittermayr, Rainer; Nickl, Stefanie; Haider, Thomas; Lebherz-Eichinger, Diana; Beer, Lucian; Mitterbauer, Andreas; Leiss, Harald; Zimmermann, Matthias; Schweiger, Thomas; Keibl, Claudia; Hofbauer, Helmut; Gabriel, Christian; Pavone-Gyöngyösi, Mariann; Redl, Heinz; Tschachler, Erwin; Mildner, Michael; Ankersmit, Hendrik Jan

    2016-01-01

    Burn wounds pose a serious threat to patients and often require surgical treatment. Skin grafting aims to achieve wound closure but requires a well-vascularized wound bed. The secretome of peripheral blood mononuclear cells (PBMCs) has been shown to improve wound healing and angiogenesis. We hypothesized that topical application of the PBMC secretome would improve the quality of regenerating skin, increase angiogenesis, and reduce scar formation after burn injury and skin grafting in a porcine model. Full-thickness burn injuries were created on the back of female pigs. Necrotic areas were excised and the wounds were covered with split-thickness mesh skin grafts. Wounds were treated repeatedly with either the secretome of cultured PBMCs (SecPBMC), apoptotic PBMCs (Apo-SecPBMC), or controls. The wounds treated with Apo-SecPBMC had an increased epidermal thickness, higher number of rete ridges, and more advanced epidermal differentiation than controls. The samples treated with Apo-SecPBMC had a two-fold increase in CD31+ cells, indicating more angiogenesis. These data suggest that the repeated application of Apo-SecPBMC significantly improves epidermal thickness, angiogenesis, and skin quality in a porcine model of burn injury and skin grafting. PMID:27125302

  4. Paracrine Factors from Irradiated Peripheral Blood Mononuclear Cells Improve Skin Regeneration and Angiogenesis in a Porcine Burn Model.

    PubMed

    Hacker, Stefan; Mittermayr, Rainer; Nickl, Stefanie; Haider, Thomas; Lebherz-Eichinger, Diana; Beer, Lucian; Mitterbauer, Andreas; Leiss, Harald; Zimmermann, Matthias; Schweiger, Thomas; Keibl, Claudia; Hofbauer, Helmut; Gabriel, Christian; Pavone-Gyöngyösi, Mariann; Redl, Heinz; Tschachler, Erwin; Mildner, Michael; Ankersmit, Hendrik Jan

    2016-01-01

    Burn wounds pose a serious threat to patients and often require surgical treatment. Skin grafting aims to achieve wound closure but requires a well-vascularized wound bed. The secretome of peripheral blood mononuclear cells (PBMCs) has been shown to improve wound healing and angiogenesis. We hypothesized that topical application of the PBMC secretome would improve the quality of regenerating skin, increase angiogenesis, and reduce scar formation after burn injury and skin grafting in a porcine model. Full-thickness burn injuries were created on the back of female pigs. Necrotic areas were excised and the wounds were covered with split-thickness mesh skin grafts. Wounds were treated repeatedly with either the secretome of cultured PBMCs (Sec(PBMC)), apoptotic PBMCs (Apo-Sec(PBMC)), or controls. The wounds treated with Apo-Sec(PBMC) had an increased epidermal thickness, higher number of rete ridges, and more advanced epidermal differentiation than controls. The samples treated with Apo-Sec(PBMC) had a two-fold increase in CD31+ cells, indicating more angiogenesis. These data suggest that the repeated application of Apo-Sec(PBMC) significantly improves epidermal thickness, angiogenesis, and skin quality in a porcine model of burn injury and skin grafting. PMID:27125302

  5. Ultrasound Evaluation of the Combined Effects of Thoracolumbar Fascia Injury and Movement Restriction in a Porcine Model

    PubMed Central

    Bishop, James H.; Fox, James R.; Maple, Rhonda; Loretan, Caitlin; Badger, Gary J.; Henry, Sharon M.; Vizzard, Margaret A.; Langevin, Helene M.

    2016-01-01

    The persistence of back pain following acute back “sprains” is a serious public health problem with poorly understood pathophysiology. The recent finding that human subjects with chronic low back pain (LBP) have increased thickness and decreased mobility of the thoracolumbar fascia measured with ultrasound suggest that the fasciae of the back may be involved in LBP pathophysiology. This study used a porcine model to test the hypothesis that similar ultrasound findings can be produced experimentally in a porcine model by combining a local injury of fascia with movement restriction using a “hobble” device linking one foot to a chest harness for 8 weeks. Ultrasound measurements of thoracolumbar fascia thickness and shear plane mobility (shear strain) during passive hip flexion were made at the 8 week time point on the non-intervention side (injury and/or hobble). Injury alone caused both an increase in fascia thickness (p = .007) and a decrease in fascia shear strain on the non-injured side (p = .027). Movement restriction alone did not change fascia thickness but did decrease shear strain on the non-hobble side (p = .024). The combination of injury plus movement restriction had additive effects on reducing fascia mobility with a 52% reduction in shear strain compared with controls and a 28% reduction compared to movement restriction alone. These results suggest that a back injury involving fascia, even when healed, can affect the relative mobility of fascia layers away from the injured area, especially when movement is also restricted. PMID:26820883

  6. Simultaneous irrigation and negative pressure wound therapy enhances wound healing and reduces wound bioburden in a porcine model.

    PubMed

    Davis, Kathryn; Bills, Jessica; Barker, Jenny; Kim, Paul; Lavery, Lawrence

    2013-01-01

    Infected foot wounds are one of the most common reasons for hospitalization and amputation among persons with diabetes. The objective of the study was to investigate a new wound therapy system that employs negative pressure wound therapy (NPWT) with simultaneous irrigation therapy. For this study, we used a porcine model with full-thickness excisional wounds, inoculated with Pseudomonas aeruginosa. Wounds were treated for 21 days of therapy with either NPWT, NPWT with simultaneous irrigation therapy using normal saline or polyhexanide biguanide (PHMB) at low or high flow rates, or control. Data show that NPWT with either irrigation condition improved wound healing rates over control-treated wounds, yet did not differ from NPWT alone. NPWT improved bioburden over control-treated wounds. NPWT with simultaneous irrigation further reduced bioburden over control and NPWT-treated wounds; however, flow rate did not affect these outcomes. Together, these data show that NPWT with simultaneous irrigation therapy with either normal saline or PHMB has a positive effect on bioburden in a porcine model, which may translate clinically to improved wound healing outcomes. PMID:24134060

  7. The intrapleural volume threshold for ultrasound detection of pneumothoraces: An experimental study on porcine models

    PubMed Central

    2013-01-01

    Background Small pneumothoraxes (PTXs) may not impart an immediate threat to trauma patients after chest injuries. However, the amount of pleural air may increase and become a concern for patients who require positive pressure ventilation or air ambulance transport. Lung ultrasonography (US) is a reliable tool in finding intrapleural air, but the performance characteristics regarding the detection of small PTXs need to be defined. The study aimed to define the volume threshold of intrapleural air when PTXs are accurately diagnosed with US and compare this volume with that for chest x-ray (CXR). Methods Air was insufflated into a unilateral pleural catheter in seven incremental steps (10, 25, 50, 100, 200, 350 and 500 mL) in 20 intubated porcine models, followed by a diagnostic evaluation with US and a supine anteroposterior CXR. The sonographers continued the US scanning until the PTXs could be ruled in, based on the pathognomonic US “lung point” sign. The corresponding threshold volume was noted. A senior radiologist interpreted the CXR images. Results The mean threshold volume to confirm the diagnosis of PTX using US was 18 mL (standard deviation of 13 mL). Sixty-five percent of the PTXs were already diagnosed at 10 mL of intrapleural air; 25%, at 25 mL; and the last 10%, at 50 mL. At an air volume of 50 mL, the radiologist only identified four out of 20 PTXs in the CXR pictures; i.e., a sensitivity of 20% (95% CI: 7%, 44%). The sensitivity of CXR increased as a function of volume but leveled off at 67%, leaving one-third (1/3) of the PTXs unidentified after 500 mL of insufflated air. Conclusion Lung US is very accurate in diagnosing even small amounts of intrapleural air and should be performed by clinicians treating chest trauma patients when PTX is among the differential diagnoses. PMID:23453044

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

    PubMed Central

    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

  9. Establishment of a simplified in vitro porcine blood–brain barrier model with high transendothelial electrical resistance

    PubMed Central

    Patabendige, Adjanie; Skinner, Robert A.; Abbott, N. Joan

    2013-01-01

    Good in vitro blood–brain barrier (BBB) models that mimic the in vivo BBB phenotype are essential for studies on BBB functionality and for initial screening in drug discovery programmes, as many potential therapeutic drug candidates have poor BBB permeation. Difficulties associated with the availability of human brain tissue, coupled with the time and cost associated with using animals for this kind of research have led to the development of non-human cell culture models. However, most BBB models display a low transendothelial electrical resistance (TEER), which is a measure of the tightness of the BBB. To address these issues we have established and optimised a robust, simple to use in vitro BBB model using porcine brain endothelial cells (PBECs). The PBEC model gives high TEER without the need for co-culture with astrocytes (up to 1300 Ω cm2 with a mean TEER of ∼800 Ω cm2) with well organised tight junctions as shown by immunostaining for occludin and claudin-5. Functional assays confirmed the presence of high levels of alkaline phosphatase (ALP), and presence of the efflux transporter, P-glycoprotein (P-gp, ABCB1). Presence of the breast cancer resistance protein (BCRP, ABCG2) was confirmed by TaqMan real-time RT-PCR assay. Real-time RT-PCR assays for BCRP, occludin and claudin-5 demonstrated no significant differences between batches of PBECs, and also between primary and passage 1 PBECs. A permeability screen of 10 compounds demonstrated the usefulness of the model as a tool for drug permeability studies. Qualitative and quantitative results from this study confirm that this in vitro porcine BBB model is reliable and robust; it is also simpler to generate than most other BBB models. This article is part of a Special Issue entitled Electrical Synapses. PMID:22789905

  10. Vesicoureteral reflux in young children: a study of radiometric thermometry as detection modality using an ex vivo porcine model

    NASA Astrophysics Data System (ADS)

    Jacobsen, Svein; Klemetsen, Øystein; Birkelund, Yngve

    2012-09-01

    Microwave radiometry is evaluated for renal thermometry tailored to detect the pediatric condition of vesicoureteral urine reflux (VUR) from the bladder through the ureter into the kidney. Prior to a potential reflux event, the urine is heated within the bladder by an external body contacting a hyperthermia applicator to generate a fluidic contrast temperature relative to normal body temperature. A single band, miniaturized radiometer (operating at 3.5 GHz) is connected to an electromagnetic-interference-shielded and suction-coupled elliptical antenna to receive thermal radiation from an ex vivo porcine phantom model. Brightness (radiometric) and fiberoptic temperature data are recorded for varying urine phantom reflux volumes (20-40 mL) and contrast temperatures ranging from 2 to 10 °C within the kidney phantom. The kidney phantom itself is located at 40 mm depth (skin-to-kidney center distance) and surrounded by the porcine phantom. Radiometric step responses to injection of urine simulant by a syringe are shown to be highly correlated with in situ kidney temperatures measured by fiberoptic probes. Statistically, the performance of the VUR detecting scheme is evaluated by error probabilities of making a wrong decision. Laboratory testing of the radiometric system supports the feasibility of passive non-invasive kidney thermometry for the detection of VUR classified within the two highest grades

  11. Vesicoureteral reflux in young children: a study of radiometric thermometry as detection modality using an ex vivo porcine model.

    PubMed

    Jacobsen, Svein; Klemetsen, Øystein; Birkelund, Yngve

    2012-09-01

    Microwave radiometry is evaluated for renal thermometry tailored to detect the pediatric condition of vesicoureteral urine reflux (VUR) from the bladder through the ureter into the kidney. Prior to a potential reflux event, the urine is heated within the bladder by an external body contacting a hyperthermia applicator to generate a fluidic contrast temperature relative to normal body temperature. A single band, miniaturized radiometer (operating at 3.5 GHz) is connected to an electromagnetic-interference-shielded and suction-coupled elliptical antenna to receive thermal radiation from an ex vivo porcine phantom model. Brightness (radiometric) and fiberoptic temperature data are recorded for varying urine phantom reflux volumes (20-40 mL) and contrast temperatures ranging from 2 to 10 °C within the kidney phantom. The kidney phantom itself is located at 40 mm depth (skin-to-kidney center distance) and surrounded by the porcine phantom. Radiometric step responses to injection of urine simulant by a syringe are shown to be highly correlated with in situ kidney temperatures measured by fiberoptic probes. Statistically, the performance of the VUR detecting scheme is evaluated by error probabilities of making a wrong decision. Laboratory testing of the radiometric system supports the feasibility of passive non-invasive kidney thermometry for the detection of VUR classified within the two highest grades. PMID:22892477

  12. 3D thoracoscopic ultrasound volume measurement validation in an ex vivo and in vivo porcine model of lung tumours

    NASA Astrophysics Data System (ADS)

    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.

  13. Dye-Free Porcine Model of Experimental Branch Retinal Vein Occlusion: A Suitable Approach for Retinal Proteomics

    PubMed Central

    Jørgensen Cehofski, Lasse; Kruse, Anders; Kjærgaard, Benedict; Stensballe, Allan; Honoré, Bent; Vorum, Henrik

    2015-01-01

    Branch retinal vein occlusion induces complex biological processes in the retina that are generated by a multitude of interacting proteins. These proteins and their posttranslational modifications can effectively be studied using modern proteomic techniques. However, no method for studying large-scale protein changes following branch retinal vein occlusion has been available until now. Obtainment of retinal tissue exposed to branch retinal vein occlusion is only available through experimental animal models. Traditional models of experimental branch retinal vein occlusion require the use of Rose Bengal dye combined with argon laser photocoagulation. The use of Rose Bengal dye is problematic in proteomic studies as the dye can induce multiple protein modifications when irradiated. This paper presents a novel technique for proteomic analysis of porcine retinal tissue with branch retinal vein occlusion combining a dye-free experimental model with label-free liquid chromatography mass spectrometry based proteomics. PMID:26064675

  14. Evaluation of a novel laparoscopic camera for characterization of renal ischemia in a porcine model using digital light processing (DLP) hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Olweny, Ephrem O.; Tan, Yung K.; Faddegon, Stephen; Jackson, Neil; Wehner, Eleanor F.; Best, Sara L.; Park, Samuel K.; Thapa, Abhas; Cadeddu, Jeffrey A.; Zuzak, Karel J.

    2012-03-01

    Digital light processing hyperspectral imaging (DLP® HSI) was adapted for use during laparoscopic surgery by coupling a conventional laparoscopic light guide with a DLP-based Agile Light source (OL 490, Optronic Laboratories, Orlando, FL), incorporating a 0° laparoscope, and a customized digital CCD camera (DVC, Austin, TX). The system was used to characterize renal ischemia in a porcine model.

  15. Cell Lineage Identification and Stem Cell Culture in a Porcine Model for the Study of Intestinal Epithelial Regeneration

    PubMed Central

    Gonzalez, Liara M.; Williamson, Ian; Piedrahita, Jorge A.; Blikslager, Anthony T.; Magness, Scott T.

    2013-01-01

    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. PMID:23840480

  16. A porcine model of relief of unilateral ureteral obstruction: study on self-repairing capability over multiple time points.

    PubMed

    Liu, Yingying; Sun, Jing; Miao, Lining; Ji, Lei; Luo, Manyu; Li, Bing; Cui, Wenpeng; Wang, Yangwei; Xie, Yuansheng; Chen, Xiangmei

    2016-08-01

    It is still controversial whether renal tubular interstitial fibrosis (TIF) is a reversible process. Although previous studies examining TIF have been carried out in rodents, their kidney size and physiological character differ with humans, and the difference among diverse individuals before and after damage was obvious. Thus an experimental animal model to simulate human kidney disease was urged to be established. In order to clarify whether TIF is reversible, and the exact time points that the kidney has the capacity to be repaired, a porcine relief of unilateral ureteral obstruction (R-UUO) model was developed. Kidney damage and reparation were observed dynamically in vivo over various time points. Pigs were randomized divided into three groups (n = 6): UUO 5 days group, UUO 7 days, and UUO 10 days group. Each porcine in that groups underwent UUO and subsequent R-UUO for three time points. Renal function, histological structure, and protein expressions of α-smooth muscle actin (α-SMA), vimentin and E-cadherin were evaluated at different time points. Following R-UUO after 5 and 7 days of UUO, compared to UUO, serum creatinine levels were significantly decreased. Renal pathological tissue damage was repaired. The expressions of α-SMA and vimentin were decreased and E-cadherin expression was increased (P < 0.05). However, during R-UUO 14, 28, and 56 days after 10 days of UUO, serum creatinine was not decreased significantly. The expressions of α-SMA and vimentin consistently remained at high levels. Renal damage was unable to be restored and resulted in chronic lesions. Kidney damage induced by UUO can be reversed in early stages. However, longer time of UUO with significant levels of TIF showed limited reversibility. The porcine R-UUO model provides an ideal animal model for the investigation of kidney injury and repair as well as for the evaluation of the effect of drug treatment. PMID:27381184

  17. Intracapsular hip pressures in a porcine model: does position and volume matter?

    PubMed

    Hosalkar, Harish S; Varley, Eric S; Glaser, Diana A; Farnsworth, Christine L; Wenger, Dennis R

    2011-09-01

    This study outlines a relationship between joint volume, positioning, and intracapsular pressure in a healthy hip. After measuring the native intracapsular pressure in 12 porcine specimens, each joint was injected with radio-opaque-colored saline as pressures were measured. At 20 mmHg, the hip was placed in its position of ease and then in differing positions while pressures were recorded. Position significantly altered pressures, with the lowest values in neutral and the highest in hyperextension (P<0.001). Extreme hip positions may be detrimental because of high pressures created within the joint, possibly explaining complications associated with some hip diagnostic and treatment methods. PMID:21606854

  18. Physiologic Changes in the Heart Following Cessation of Mechanical Ventilation in a Porcine Model of Donation After Circulatory Death: Implications for Cardiac Transplantation.

    PubMed

    White, C W; Lillico, R; Sandha, J; Hasanally, D; Wang, F; Ambrose, E; Müller, A; Rachid, O; Li, Y; Xiang, B; Le, H; Messer, S; Ali, A; Large, S R; Lee, T W; Dixon, I M C; Lakowski, T M; Simons, K; Arora, R C; Tian, G; Nagendran, J; Hryshko, L V; Freed, D H

    2016-03-01

    Hearts donated following circulatory death (DCD) may represent an additional source of organs for transplantation; however, the impact of donor extubation on the DCD heart has not been well characterized. We sought to describe the physiologic changes that occur following withdrawal of life-sustaining therapy (WLST) in a porcine model of DCD. Physiologic changes were monitored continuously for 20 min following WLST. Ventricular pressure, volume, and function were recorded using a conductance catheter placed into the right (N = 8) and left (N = 8) ventricles, and using magnetic resonance imaging (MRI, N = 3). Hypoxic pulmonary vasoconstriction occurred following WLST, and was associated with distension of the right ventricle (RV) and reduced cardiac output. A 120-fold increase in epinephrine was subsequently observed that produced a transient hyperdynamic phase; however, progressive RV distension developed during this time. Circulatory arrest occurred 7.6±0.3 min following WLST, at which time MRI demonstrated an 18±7% increase in RV volume and a 12±9% decrease in left ventricular volume compared to baseline. We conclude that hypoxic pulmonary vasoconstriction and a profound catecholamine surge occur following WLST that result in distension of the RV. These changes have important implications on the resuscitation, preservation, and evaluation of DCD hearts prior to transplantation. PMID:26663659

  19. Contrast-enhanced sonothrombolysis in a porcine model of acute peripheral arterial thrombosis and prevention of anaphylactic shock.

    PubMed

    Nederhoed, Johanna H; Slikkerveer, Jeroen; Meyer, Klaas W; Wisselink, Willem; Musters, René J P; Yeung, Kak K

    2014-03-01

    Acute peripheral arterial thrombosis can be threatening to life and limb. Dissolution of the thrombus local catheter-directed intra-arterial infusion of fibrinolytic agents such as urokinase is the standard therapy for thrombosis; however, this method is time-intensive, and amputation of the affected limb is still needed in 10-30% of cases. Furthermore, thrombolytic therapy carries the risk of bleeding complications. The use of small gas-filled bubbles, or ultrasound contrast agents (UCAs), in combination with ultrasound has been investigated as an improved thrombolytic therapy in acute coronary and cerebral arterial thrombosis. The authors describe a porcine model of acute peripheral arterial occlusion to test contrast-enhanced sonothrombolysis approaches that combine ultrasound, UCAs and fibrinolytic agents and recommend a strategy for preventing severe allergic reactions to UCAs in the pigs. PMID:24552914

  20. Silver absorption on burns after the application of Acticoat: data from pediatric patients and a porcine burn model.

    PubMed

    Wang, Xue-Qing; Kempf, Margit; Mott, Jonathon; Chang, Hong-En; Francis, Rod; Liu, Pei-Yun; Cuttle, Leila; Olszowy, Henry; Kravchuk, Olena; Mill, Julie; Kimble, Roy M

    2009-01-01

    Silver dressings have been widely used to successfully prevent burn wound infection and sepsis. However, a few case studies have reported the functional abnormality and failure of vital organs, possibly caused by silver deposits. The aim of this study was to investigate the serum silver level in the pediatric burn population and also in several internal organs in a porcine burn model after the application of Acticoat. A total of 125 blood samples were collected from 46 pediatric burn patients. Thirty-six patients with a mean of 13.4% TBSA burns had a mean peak serum silver level of 114 microg/L, whereas 10 patients with a mean of 1.85% TBSA burns had an undetectable level of silver (<5.4 microg/L). Overall, serum silver levels were closely related to burn sizes. However, the highest serum silver was 735 microg/L in a 15-month-old toddler with 10% TBSA burns and the second highest was 367 microg/L in a 3-year old with 28% TBSA burns. In a porcine model with 2% TBSA burns, the mean peak silver level was 38 microg/L at 2 to 3 weeks after application of Acticoat and was then significantly reduced to an almost undetectable level at 6 weeks. Of a total of four pigs, silver was detected in all four livers (1.413 microg/g) and all four hearts (0.342 microg/g), three of four kidneys (1.113 microg/g), and two of four brains (0.402 microg/g). This result demonstrated that although variable, the level of serum silver was positively associated with the size of burns, and significant amounts of silver were deposited in internal organs in pigs with only 2% TBSA burns, after application of Acticoat. PMID:19165102

  1. Efficacy of platelet-rich plasma as a shielding technique after endoscopic mucosal resection in rat and porcine models

    PubMed Central

    Lorenzo-Zúñiga, Vicente; Boix, Jaume; Moreno de Vega, Vicente; Bon, Ignacio; Marín, Ingrid; Bartolí, Ramón

    2016-01-01

    Background and study aims: The aims were to assess the efficacy of endoscopic application of Platelet-rich plasma (PRP) to prevent delayed perforation and to induce mucosal healing after endoscopic resections. Patients and methods: Colonic induced lesions were performed in rats (n = 16) and pigs (n = 4). Animals were randomized to receive onto the lesions saline (control) or PRP. Animals underwent endoscopic follow-up. Thermal injury was assessed with a 1 – 4 scale: (1) mucosal necrosis; (2) submucosal necrosis; (3) muscularis propria necrosis; and (4) serosal necrosis Results: Saline treatment showed 50 % of mortality in rats (P = 0.02). Mean ulcerated area after 48 hours and 7 days was significantly smaller with PRP than with saline (0.27 ± 0.02 cm2 and 0.08 ± 0.01 cm2 vs. 0.56 ± 0.1 cm2 and 0.40 ± 0.06 cm2; P < 0.001). The incidence of thermal injury was significantly lower with PRP (1.25 ± 0.46) than in controls (2.25 ± 0.50); P = 0.006. The porcine model showed a trend toward higher mucosal restoration in animals treated with PRP than with saline at weeks 1 and 2 (Median area in cm2: 0.55 and 0.40 vs. 1.32 and 0.79) Conclusions: Application of PRP to colonic mucosal lesions showed strong healing properties in rat and porcine models. PMID:27540573

  2. Effects of Intracoronary Administration of Autologous Adipose Tissue-Derived Stem Cells on Acute Myocardial Infarction in a Porcine Model

    PubMed Central

    Lee, Hye Won; Park, Jong Ha; Kim, Bo Won; Ahn, Jinhee; Kim, Jin Hee; Park, Jin Sup; Oh, Jun-Hyok; Choi, Jung Hyun; Cha, Kwang Soo; Hong, Taek Jong; Park, Tae Sik; Kim, Sang-Pil; Song, Seunghwan; Kim, Ji Yeon; Park, Mi Hwa; Jung, Jin Sup

    2015-01-01

    Purpose Adipose-derived stem cells (ADSCs) are known to be potentially effective in regeneration of damaged tissue. We aimed to assess the effectiveness of intracoronary administration of ADSCs in reducing the infarction area and improving function after acute transmural myocardial infarction (MI) in a porcine model. Materials and Methods ADSCs were obtained from each pig's abdominal subcutaneous fat tissue by simple liposuction. After 3 passages of 14-days culture, 2 million ADSCs were injected into the coronary artery 30 min after acute transmural MI. At baseline and 4 weeks after the ADSC injection, 99mTc methoxyisobutylisonitrile-single photon emission computed tomography (MIBI-SPECT) was performed to evaluate the left ventricular volume, left ventricular ejection fraction (LVEF; %), and perfusion defects as well as the myocardial salvage (%) and salvage index. At 4 weeks, each pig was sacrificed, and the heart was extracted and dissected. Gross and microscopic analyses with specific immunohistochemistry staining were then performed. Results Analysis showed improvement in the perfusion defect, but not in the LVEF in the ADSC group (n=14), compared with the control group (n=14) (perfusion defect, -13.0±10.0 vs. -2.6±12.0, p=0.019; LVEF, -8.0±15.4 vs. -15.9±14.8, p=0.181). There was a tendency of reducing left ventricular volume in ADSC group. The ADSCs identified by stromal cell-derived factor-1 (SDF-1) staining were well co-localized by von Willebrand factor and Troponin T staining. Conclusion Intracoronary injection of cultured ADSCs improved myocardial perfusion in this porcine acute transmural MI model. PMID:26446632

  3. Decolonisation of MRSA, S. aureus and E. coli by Cold-Atmospheric Plasma Using a Porcine Skin Model In Vitro

    PubMed Central

    Maisch, Tim; Shimizu, Tetsuji; Li, Yang-Fang; Heinlin, Julia; Karrer, Sigrid; Morfill, Gregor; Zimmermann, Julia L.

    2012-01-01

    In the last twenty years new antibacterial agents approved by the U.S. FDA decreased whereas in parallel the resistance situation of multi-resistant bacteria increased. Thus, community and nosocomial acquired infections of resistant bacteria led to a decrease in the efficacy of standard therapy, prolonging treatment time and increasing healthcare costs. Therefore, the aim of this work was to demonstrate the applicability of cold atmospheric plasma for decolonisation of Gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Methicillin-sensitive Staphylococcus aureus) and Gram-negative bacteria (E. coli) using an ex vivo pig skin model. Freshly excised skin samples were taken from six month old female pigs (breed: Pietrain). After application of pure bacteria on the surface of the explants these were treated with cold atmospheric plasma for up to 15 min. Two different plasma devices were evaluated. A decolonisation efficacy of 3 log10 steps was achieved already after 6 min of plasma treatment. Longer plasma treatment times achieved a killing rate of 5 log10 steps independently from the applied bacteria strains. Histological evaluations of untreated and treated skin areas upon cold atmospheric plasma treatment within 24 h showed no morphological changes as well as no significant degree of necrosis or apoptosis determined by the TUNEL-assay indicating that the porcine skin is still vital. This study demonstrates for the first time that cold atmospheric plasma is able to very efficiently kill bacteria applied to an intact skin surface using an ex vivo porcine skin model. The results emphasize the potential of cold atmospheric plasma as a new possible treatment option for decolonisation of human skin from bacteria in patients in the future without harming the surrounding tissue. PMID:22558091

  4. Semi-spherical Radiofrequency Bipolar Device - A New Technique for Liver Resection: Experimental In Vivo Study on the Porcine Model.

    PubMed

    Vavra, P; Penhaker, M; Jurcikova, J; Skrobankova, M; Crha, M; Ostruszka, P; Ihnat, P; Grepl, J; Delongova, P; Dvorackova, J; Prochazka, V; Salounova, D; Skoric, M; Rauser, P; Habib, N; Zonca, P

    2015-10-01

    The incidence of colorectal carcinoma is still growing in the Czech Republic and also all around the world. With success of oncological treatment is also growing a number of potential patients with liver metastases, who can profit from surgical therapy. The aim of this study was to confirm on porcine models that this method by using new surgical device is effective and safe for patients who have to undergo liver resection. The primary hypothesis of the study was to evaluate whether this new device is able to consistently produce homogeneous and predictable areas of coagulation necrosis without the Pringle maneuver of vascular inflow occlusion. The secondary hypothesis of the study was to compare the standard linear radiofrequency device and a new semi-spherical bipolar device for liver ablation and resection in a hepatic porcine model. Twelve pigs were randomly divided into two groups. Each pig underwent liver resection from both liver lobes in the marginal, thinner part of liver parenchyma. The pigs in first group were operated with standard using device and in the second group we used new developed semi-spherical device. We followed blood count in 0(th), 14(th) and 30(th) day from operation. 14(th) day from resection pigs underwent diagnostic laparoscopy to evaluate of their state, and 30(th) day after operation were all pigs euthanized and subjected to histopathological examination. Histopathological evaluation of thermal changes at the resection margin showed strong thermal alteration in both groups. Statistical analysis of collected dates did not prove any significant (p < 0.05) differences between standard using device and our new surgical tool. We proved safety of new designed semi-spherical surgical. This device can offer the possibility of shortening the ablation time and operating time, which is benefit for patients undergoing the liver resection. PMID:24945372

  5. Pericytes support neutrophil transmigration via interleukin-8 across a porcine co-culture model of the blood-brain barrier.

    PubMed

    Pieper, Christian; Pieloch, Paulina; Galla, Hans-Joachim

    2013-08-01

    Transmigration of neutrophils across the blood-brain barrier (BBB) to an inflamed brain tissue is an important process during neuronal inflammation. The process of neutrophil activation as well as their way of rolling along the endothelium and their transmigration is quite well understood. Nevertheless, relatively little is known about the fate of neutrophils after they have transmigrated through the endothelium. The role of the other cells of the neurovascular unit in this process is also poorly understood. Here we studied the potential of pericytes to chemo-attract neutrophils under inflammatory conditions. Quantitative real time PCR, western blot analysis, and a chemotaxis assay showed that pericytes are able to chemo-attract neutrophils by interleukin-8 (IL-8) after stimulation with lipopolysaccharides (LPS), tumor necrosis factor-alpha (TNF-α), or interleukin-1beta (IL-1β). Then, a co-culture model consisting of primary porcine brain capillary endothelial cells (PBCECs) and primary porcine brain capillary pericytes (PBCPs) was used to analyze neutrophil transmigration across the BBB. As a model for inflammation, LPS was used and the effects of the cytokines TNF-α, IL-1β, and interferon-gamma (IFN-γ) were analyzed. In general, all stimulants apart from IFN-γ were able to increase transendothelial neutrophil migration. This effect was significantly reduced by a specific inhibitor of matrix metalloproteinases (MMPs)-2 and -9. MMP-2/-9 secretion is expected to decrease adhesion to pericytes and thus support the transmigration of neutrophils. Additionally, in an adhesion experiment, we showed that MMP-2/-9 inhibition significantly enhances the adhesion of neutrophils to pericytes. PMID:23769734

  6. Progenitor Cell Therapy in a Porcine Acute Myocardial Infarction Model Induces Cardiac Hypertrophy, Mediated by Paracrine Secretion of Cardiotrophic Factors Including TGFβ1

    PubMed Central

    Doyle, Brendan; Sorajja, Paul; Hynes, Brian; Kumar, Arun H.S.; Araoz, Phillip A.; Stalboerger, Paul G.; Miller, Dylan; Reed, Cynthia; Schmeckpeper, Jeffrey; Wang, Shaohua; Liu, Chunsheng; Terzic, Andre; Kruger, David; Riederer, Stephen

    2008-01-01

    Administration of endothelial progenitor cells (EPC) is a promising therapy for post-infarction cardiac repair. However, the mechanisms that underlie apparent beneficial effects on myocardial remodeling are unclear. In a porcine model of acute myocardial infarction, we investigated the therapeutic effects of a mixed population of culture modified peripheral blood mononuclear cells (termed hereafter porcine EPC). Porcine EPC were isolated using methods identical to those previously adopted for harvest of EPC in human cell therapy studies. In addition the therapeutic effects of paracrine factors secreted by these cells was evaluated in vitro and in vivo. Intracoronary injection of autologous porcine EPC was associated with increased infarct territory mass and improved regional ventricular systolic function at 2 months compared to control. Treatment with conditioned media derived from autologous EPC was associated with similar improved effects on infarct territory mass and function. Histologic analysis of the infarct territory revealed significantly increased cardiomyocyte size in EPC and conditioned media treated groups, when compared to controls. A paracrine EPC effect was also verified in a pure myocardial preparation in which cardiomyocytes devoid of fibroblast, neuronal and vascular elements directly responded by increasing cell mass when exposed to the same conditioned media. Analysis of conditioned media revealed elevated levels of TGFβ1 (human 267.3±11.8 pg/ml, porcine 57.1±6.1 pg/ml), a recognized mediator of hypertrophic signaling in the heart. Neutralizing antibodies to TGFβ1 attenuated the pro-hypertrophic effect of conditioned media, and use of recombinant TGFβ1 added to fresh media replicated the pro-hypertrophic effects of conditioned media in vitro. These data demonstrate the potential of paracrine factors secreted from endothelial progenitor cells to induce cardiomyocyte hypertrophy contributing to increased infarct territory LV mass, with

  7. Enzymolysis kinetics, thermodynamics and model of porcine cerebral protein with single-frequency countercurrent and pulsed ultrasound-assisted processing.

    PubMed

    Zou, Ye; Ding, Yangyang; Feng, Weiwei; Wang, Wei; Li, Qian; Chen, Yao; Wu, Huiyu; Wang, Xintong; Yang, Liuqing; Wu, Xiangyang

    2016-01-01

    The present work investigated the enzymolysis kinetics, thermodynamics and model of porcine cerebral protein (PCP) which was pretreated by single-frequency countercurrent and pulsed ultrasound. The kinetic constants for ultrasonic pretreated and traditional enzymolysis have been determined. Results showed that the value of KM in ultrasonic PCP (UPCP) enzymolysis decreased by 9% over that in the traditional enzymolysis. The values of reaction rate constant (k) for UPCP enzymolysis increased by 207%, 121%, 62%, and 45% at 293, 303, 313 and 323 K, respectively. For the thermodynamic parameters, ultrasound decreased activation energy (Ea), change in enthalpy (ΔH) and entropy (ΔS) by 76%, 82% and 31% in PCP, respectively. However, ultrasound had little change in Gibbs free energy (ΔG) value in the temperature range of 293-323 K. Therefore, a general kinetic equation for the enzymolysis model of UPCP by a simple empirical equation was suggested. The experimental values fits with the enzymolysis kinetic model with a low average relative error (4%) confirmed that the kinetic model was accurate to reflect the enzymolysis process. The positive effect of single-frequency countercurrent and pulsed ultrasound in this study and application of the kinetic model may be useful for the release of bioactive peptides from meat processing by-products. PMID:26384911

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

    PubMed

    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. PMID:26838473

  9. Evaluation of intravascular microdialysis for continuous blood glucose monitoring in hypoglycemia: an animal model.

    PubMed

    Schierenbeck, Fanny; Wallin, Mats; Franco-Cereceda, Anders; Liska, Jan

    2014-07-01

    We have previously shown that intravascular microdialysis in a central vein is an accurate method for continuous glucose monitoring in patients undergoing cardiac surgery. However, no hypoglycemia occurred in our earlier studies, prompting further evaluation of the accuracy of intravascular microdialysis in the hypoglycemic range. Thus, this animal study was performed. A porcine model was developed; hypoglycemia was induced using insulin injections. The pigs were monitored with intravascular microdialysis integrated in a triple-lumen central venous catheter. As reference, venous blood gas samples were taken every 5 minutes and analyzed in a blood gas analyzer. Ethical permission for the animal experiments was obtained from the Stockholm Regional Ethical Committee, reference no N397/09. A total of 213 paired samples were obtained for analysis, and 126 (59.2%) of these were in the hypoglycemic range (<74 mg/dl). Using Clarke error grid analysis, 100% of the paired samples were in region AB and 99% in region A. The ISO standard (ISO15197) was met. Bland-Altman analysis showed bias (mean difference) ± limits of agreement was -0.18 ± 16.2 mg/dl. No influence from glucose infusions was seen. The microdialysis monitoring system was found to be very responsive in rapid changes in blood glucose concentration. This study shows that intravascular microdialysis in a central vein is an accurate method for continuous glucose monitoring in hypoglycemia in a porcine experimental model. Furthermore, the system was not influenced by glucose administration and was found to be responsive in rapid blood glucose fluctuations. PMID:24876424

  10. In-vivo tissue repair using light-activated surgical adhesive in a porcine model

    NASA Astrophysics Data System (ADS)

    McNally-Heintzelman, Karen M.; Riley, Jill N.; Dickson, Tonya J.; Hou, Dong Ming; Rogers, Pamela; March, Keith L.

    2001-05-01

    An in vivo study was conducted to investigate the feasibility, mechanical function, and chronic biocompatibility of a new light-activated surgical adhesive for achieving rapid hemostasis of the puncture site following diagnostic catheterization and interventional cardiac procedures. Porcine carotid arteries (nequals6) and femoral arteries (nequals6) were exposed, and an incision was made in the arterial walls using a 16G needle. The surgical adhesive, composed of a poly(L-lactic-co-glycolic acid) scaffold doped with the traditional protein solder mix of serum albumin and indocyanine green dye, was used to close the incisions in conjunction with an 805-nm diode laser. Blood flow was restored to the vessels immediately after the procedure and the incision sites were checked for patency. The strength and hemostatic abilities of the new surgical adhesive were evaluated in the context of arterial pressure, persistence of hemostatis and presence of any inflammatory reaction after 3 days. After this evaluation period, the surgical procedure was repeated on the carotid arteries (nequals6) and femoral arteries (nequals6) of three additional animals that had been heparinized prior to surgery to closer approximate the conditions seen in a typical vascular surgical setting.

  11. Investigating detrusor muscle concentrations of oxybutynin after intravesical delivery in an ex vivo porcine model.

    PubMed

    Williams, Nicholas A; Lee, Kay M; Allender, Chris J; Bowen, Jenna L; Gumbleton, Mark; Harrah, Tim; Raja, Aditya; Joshi, Hrishi B

    2015-07-01

    Intravesical oxybutynin is highly effective in the treatment of overactive bladder. Traditionally the mechanism of action was explained by antagonism of muscarinic receptors located in the detrusor, however evidence now suggests antimuscarinics may elicit their effect by modifying afferent pathways in the mucosal region. This study aimed to investigate the bladder wall distribution of oxybutynin in an ex vivo setting providing tissue - layer specific concentrations of drug achieved after intravesical delivery. Whole ex vivo porcine bladders were intravesically instilled with 0.167 mg mL(-1) oxybutynin solution. After 60 min, tissue samples were excised, serially sectioned parallel to the urothelial surface and extracted drug quantified. Drug distribution into the urothelium, lamina propria and detrusor was determined. Oxybutynin permeated into the bladder wall at a higher rate than other drugs previously investigated (apparent transurothelial Kp = 1.36 × 10(-5) cm s(-1) ). After 60 min intravesical instillation, concentrations achieved in the urothelium (298.69 μg g(-1) ) and lamina propria (43.65 μg g(-1) ) but not the detrusor (0.93 μg g(-1) ) were greater than reported IC50 values for oxybutynin. This work adds to the increasing body of evidence suggesting antimuscarinics elicit their effects via mechanisms other than direct inhibition of detrusor contraction. PMID:25989054

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

    SciTech Connect

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

    2011-12-15

    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.

  13. Using heterogeneity in the population structure of U.S. swine farms to compare transmission models for porcine epidemic diarrhoea

    PubMed Central

    O’Dea, Eamon B.; Snelson, Harry; Bansal, Shweta

    2016-01-01

    In 2013, U.S. swine producers were confronted with the disruptive emergence of porcine epidemic diarrhoea (PED). Movement of animals among farms is hypothesised to have played a role in the spread of PED among farms. Via this or other mechanisms, the rate of spread may also depend on the geographic density of farms and climate. To evaluate such effects on a large scale, we analyse state-level counts of outbreaks with variables describing the distribution of farm sizes and types, aggregate flows of animals among farms, and an index of climate. Our first main finding is that it is possible for a correlation analysis to be sensitive to transmission model parameters. This finding is based on a global sensitivity analysis of correlations on simulated data that included a biased and noisy observation model based on the available PED data. Our second main finding is that flows are significantly associated with the reports of PED outbreaks. This finding is based on correlations of pairwise relationships and regression modeling of total and weekly outbreak counts. These findings illustrate how variation in population structure may be employed along with observational data to improve understanding of disease spread. PMID:26947420

  14. Development of a novel ex vivo porcine skin explant model for the assessment of mature bacterial biofilms.

    PubMed

    Yang, Qingping; Phillips, Priscilla L; Sampson, Edith M; Progulske-Fox, Ann; Jin, Shouguang; Antonelli, Patrick; Schultz, Gregory S

    2013-01-01

    Bacterial biofilms have been proposed to be a major factor contributing to the failure of chronic wounds to heal because of their increased tolerance to antimicrobial agents and the prolonged inflammation they cause. Phenotypic characteristics of bacterial biofilms vary depending on the substratum to which they attach, the nutritional environment, and the microorganisms within the biofilm community. To develop an ex vivo biofilm model that more closely mimics biofilms in chronic skin wounds, we developed an optimal procedure to grow mature biofilms on a central partial-thickness wound in 12-mm porcine skin explants. Chlorine gas produced optimal sterilization of explants while preserving histological properties of the epidermis and dermis. Pseudomonas aeruginosa and Staphylococcus aureus developed mature biofilms after 3 days that had dramatically increased tolerance to gentamicin and oxacillin (∼100× and 8,000× minimal inhibitory concentration, respectively) and to sodium hypochlorite (0.6% active chlorine). Scanning electron microscopy and confocal microscopy verified extensive exopolymeric biofilm structures on the explants. Despite a significant delay, a ΔlasI quorum-sensing mutant of P. aeruginosa developed biofilm as antibiotic-tolerant as wild-type after 3 days. This ex vivo model simulates growth of biofilms on skin wounds and provides an accurate model to assess effects of antimicrobial agents on mature biofilms. PMID:23927831

  15. Hybrid Modeling Improves Health and Performance Monitoring

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Scientific Monitoring Inc. was awarded a Phase I Small Business Innovation Research (SBIR) project by NASA's Dryden Flight Research Center to create a new, simplified health-monitoring approach for flight vehicles and flight equipment. The project developed a hybrid physical model concept that provided a structured approach to simplifying complex design models for use in health monitoring, allowing the output or performance of the equipment to be compared to what the design models predicted, so that deterioration or impending failure could be detected before there would be an impact on the equipment's operational capability. Based on the original modeling technology, Scientific Monitoring released I-Trend, a commercial health- and performance-monitoring software product named for its intelligent trending, diagnostics, and prognostics capabilities, as part of the company's complete ICEMS (Intelligent Condition-based Equipment Management System) suite of monitoring and advanced alerting software. I-Trend uses the hybrid physical model to better characterize the nature of health or performance alarms that result in "no fault found" false alarms. Additionally, the use of physical principles helps I-Trend identify problems sooner. I-Trend technology is currently in use in several commercial aviation programs, and the U.S. Air Force recently tapped Scientific Monitoring to develop next-generation engine health-management software for monitoring its fleet of jet engines. Scientific Monitoring has continued the original NASA work, this time under a Phase III SBIR contract with a joint NASA-Pratt & Whitney aviation security program on propulsion-controlled aircraft under missile-damaged aircraft conditions.

  16. Numerical modeling for underground nuclear test monitoring

    NASA Astrophysics Data System (ADS)

    Taylor, Steven R.; Kamm, James R.

    The symposium for Numerical Modeling for Underground Nuclear Test Monitoring was held March 23-25 in Durango, Colo. Funded by the DOE Office of Arms Control and Nonproliferation (OACN) and hosted by the Source Region Program at Los Alamos National Laboratory (LANL), the meetings's purpose was to discuss the state-of-the-art in numerical simulations of nuclear explosion phenomenology with applications to test-ban monitoring. In particular, we wished to focus on the uniqueness of model fits to data, the measurement and characterization of material response models, advanced modeling techniques, and applications of modeling to monitoring problems.The concept for the meeting arose through discussions with Marv Denny, who was on assignment at Department of Energy Headquarters from Lawrence Livermore National Laboratory (LLNL). In these conversations, the following question was discussed: how are numerical modeling techniques being used to understand the effects of explosion- source phenomenology on test-ban treaty monitoring? Numerical studies are becoming increasingly important in the evaluation of capabilities for proliferation monitoring; this trend has accelerated with the curtailment of the nuclear testing program. During these discussions, the issue of the uniqueness and limitations of numerical models arose. It was decided to address these questions by convening a group of experts to present and discuss the problems associated with modeling of close-in data from explosions.

  17. Effect of stents coated with a combination of sirolimus and alpha-lipoic acid in a porcine coronary restenosis model.

    PubMed

    Lim, Kyung Seob; Park, Jun-Kyu; Jeong, Myung Ho; Bae, In-Ho; Nah, Jae-Woon; Park, Dae Sung; Kim, Jong Min; Kim, Jung Ha; Lee, So Youn; Jang, Eun Jae; Jang, Suyoung; Kim, Hyun Kuk; Sim, Doo Sun; Park, Keun-Ho; Hong, Young Joon; Ahn, Youngkeun; Kang, Jung Chaee

    2016-04-01

    The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-L-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78% in BMS vs. 51.5 ± 12.20% in AES vs. 34.7 ± 7.23% in SES vs. 28.7 ± 7.30% in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0-1.0) in BMS vs. 1.0 (range 1.0-1.0) in AES vs. 2.0 (range 2.0-2.0) in SES vs. 2.0 (range 2.0-2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88% in BMS vs. 50.4 ± 14.87% in AES vs. 34.5 ± 7.22% in SES vs. 28.9 ± 7.22% in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia. PMID:26886814

  18. In-vivo regional myocardial perfusion measurements in a porcine model by ECG-gated multislice computed tomography

    NASA Astrophysics Data System (ADS)

    Stantz, Keith M.; Liang, Yun; Meyer, Cristopher A.; Teague, Shawn; Stecker, Michael; Hutchins, Gary; McLennan, Gordon; Persohn, Scott

    2003-05-01

    Purpose: To evaluate whether functional multi-slice computed tomography (MSCT) can identify regional areas of normally perfused and ischemic myocardium in a porcine model. Material and Methods: Three out bred pigs, two of which had ameroids surgically implanted to constrict flow within the LAD and LCx coronary arteries, were injected with 25 mL of iopromide (Isovue) at a rate of 5 mL/second via the femoral or jugular vein. Sixty axial scans along the short axis of the heart was acquired on a 16-slice CT scanner (Philips MX8000-IDT) triggered at end-diastole of the cardiac cycle and acquiring an image within 270 msec. A second series of scans were taken after an intravenous injection of a vasodilator, 150 μg/kg/min of adenosine. ROIs were drawn around the myocardial tissue and the resulting time-density curves were used to extract perfusion values. Results: Determination of the myocardial perfusion and fractional blood volume implementing three different perfusion models. A 5-point averaging or 'smoothing' algorithm was employed to effectively filter the data due to its noisy nature. The (preliminary) average perfusion and fractional blood volume values over selected axial slices for the pig without an artificially induced stenosis were measured to be 84 +/- 22 mL/min/100g-tissue and 0.17 +/- 0.04 mL/g-tissue, the former is consistent with PET scan and EBCT results. The pig with a stenosis in the left LAD coronary artery showed a reduced global perfusion value -- 45 mL/min/100g-tissue. Correlations in regional perfusion values relative to the stenosis were weak. During the infusion of adenosine, averaged perfusion values for the three subjects increased by 46 (+/-45) percent, comparable to increases measured with PET. Conclusion: Quantifying global perfusion values using MDCT appear encouraging. Future work will focus resolving the systematic effects from noise due to signal fluctuation from the porcine tachyardia (80-93 BPM) and provide a more robust measurement

  19. Mechanical Intestinal Obstruction in a Porcine Model: Effects of Intra-Abdominal Hypertension. A Preliminary Study

    PubMed Central

    Sánchez-Margallo, F. M.; Latorre, R.; López-Albors, O.; Wise, R.; Malbrain, M. L. N. G.; Castellanos, G.

    2016-01-01

    Introduction Mechanical intestinal obstruction is a disorder associated with intra-abdominal hypertension and abdominal compartment syndrome. As the large intestine intraluminal and intra-abdominal pressures are increased, so the patient’s risk for intestinal ischaemia. Previous studies have focused on hypoperfusion and bacterial translocation without considering the concomitant effect of intra-abdominal hypertension. The objective of this study was to design and evaluate a mechanical intestinal obstruction model in pigs similar to the human pathophysiology. Materials and Methods Fifteen pigs were divided into three groups: a control group (n = 5) and two groups of 5 pigs with intra-abdominal hypertension induced by mechanical intestinal obstruction. The intra-abdominal pressures of 20 mmHg were maintained for 2 and 5 hours respectively. Hemodynamic, respiratory and gastric intramucosal pH values, as well as blood tests were recorded every 30 min. Results Significant differences between the control and mechanical intestinal obstruction groups were noted. The mean arterial pressure, cardiac index, dynamic pulmonary compliance and abdominal perfusion pressure decreased. The systemic vascular resistance index, central venous pressure, pulse pressure variation, airway resistance and lactate increased within 2 hours from starting intra-abdominal hypertension (p<0.05). In addition, we observed increased values for the peak and plateau airway pressures, and low values of gastric intramucosal pH in the mechanical intestinal obstruction groups that were significant after 3 hours. Conclusion The mechanical intestinal obstruction model appears to adequately simulate the pathophysiology of intestinal obstruction that occurs in humans. Monitoring abdominal perfusion pressure, dynamic pulmonary compliance, gastric intramucosal pH and lactate values may provide insight in predicting the effects on endorgan function in patients with mechanical intestinal obstruction. PMID

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

    PubMed Central

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

    2016-01-01

    Background 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. 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 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. 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 conditions, since it, if so, potentially could represent a new drug for stabilizing small abdominal aneurysms. PMID:27144001

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

    NASA Astrophysics Data System (ADS)

    Cain, Clarence P.; Polhamus, Garrett D.; Roach, William P.; Stolarski, David J.; Schuster, Kurt J.; Stockton, Kevin; Rockwell, Benjamin A.; Chen, Bo; Welch, Ashley J.

    2006-07-01

    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 µs) at 24-h postexposure are measured to be 99 and 83 Jcm-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 Jcm-2 for a 5-mm-diam top-hat laser pulse.

  2. Increased survival time after delayed histamine and prostaglandin blockade in a porcine model of severe sepsis-induced lung injury.

    PubMed

    Byrne, K; Sielaff, T D; Michna, B; Carey, P D; Blocher, C R; Vasquez, A; Sugerman, H J

    1990-03-01

    A combination of cimetidine, diphenhydramine, and ibuprofen has been shown to be an effective treatment in a porcine model of septic acute lung injury. The present study was designed to evaluate this therapy in a delayed treatment survival model. Three groups of animals were studied: a control group (C, n = 6) received a sham infusion of 0.9% saline; a septic group (Ps, n = 5) received a continuous infusion of live Pseudomonas aeruginosa organisms; and a treatment group (CID, n = 6) received P. aeruginosa plus cimetidine 150 mg, ibuprofen 12.5 mg/kg, and diphenhydramine 10 mg/kg given at 90 min after P. aeruginosa infusion, and hourly thereafter. Group Ps developed fulminant acute lung injury and hypodynamic septic shock. CID therapy ameliorated temporarily the progressive course of hypoxemia and increased extravascular lung water (EVLW), delayed the onset of cardiovascular deterioration, and improved significantly survival time. It was concluded that CID therapy given at 90 min after the onset of lethal continuous P. aeruginosa infusion improved significantly animal survival time by improving temporarily hypoxemia and increase in EVLW and delaying cardiovascular collapse. PMID:2302957

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

    PubMed

    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 < or =0.05. Our results showed similar preoperative penile length and circumference in both groups. However, 2 months after the surgery, the mean penile circumference of the SIS group has grown significantly larger than the control group, while the mean penile length remained unchanged. The histological study of the rat penises revealed minimal amounts of fibrosis under the graft, and the elastic fibers of the graft showed orientation in a circular manner. In conclusion, SIS appears promising for material use in a penile enhancement. PMID:16049525

  4. Is intervertebral disc pressure linked to herniation?: An in-vitro study using a porcine model.

    PubMed

    Noguchi, Mamiko; Gooyers, Chad E; Karakolis, Thomas; Noguchi, Kimihiro; Callaghan, Jack P

    2016-06-14

    Approximately 40% of low back pain cases have been attributed to internal disc disruption. This disruption mechanism may be linked to intradiscal pressure changes, since mechanical loading directly affects the pressure and the stresses that the inner annulus fibrosus experiences. The objective of this study was to characterize cycle-varying changes in four dependent measures (intradiscal pressure, flexion-extension moments, specimen height loss, and specimen rotation angle) using a cyclic flexion-extension (CFE) loading protocol known to induce internal disc disruption. A novel bore-screw pressure sensor system was used to instrument 14 porcine functional spinal units. The CFE loading protocol consisted of 3600 cycles of flexion-extension range of motion (average 18.30 (SD 3.76) degrees) at 1Hz with 1500N of compressive load. On average, intradiscal pressure and specimen height decreased by 47% and 62%, respectively, and peak moments increased by 102%. From 900 to 2100 cycles, all variables exhibited significant changes between successive time points, except for the specimen posture at maximum pressure, which demonstrated a significant shift towards flexion limit after 2700 cycles. There were no further changes in pressure range after 2100 cycles, whereas peak moments and height loss were significantly different from prior time points throughout the CFE protocol. Twelve of the 14 specimens showed partial herniation; however, injury type was not significantly correlated to any of the dependent measures. Although change in pressure was not predictive of damage type, the increase in pressure range seen during this protocol supports the premise that repetitive combined loading (i.e., radial compression, tension and shear) imposes damage to the inner annulus fibrosus, and its failure mechanism may be linked to fatigue. PMID:27157242

  5. Long-Term Effects of Induced Hypothermia on Local and Systemic Inflammation - Results from a Porcine Long-Term Trauma Model

    PubMed Central

    Horst, K.; Eschbach, D.; Pfeifer, R.; Relja, B.; Sassen, M.; Steinfeldt, T.; Wulf, H.; Vogt, N.; Frink, M.; Ruchholtz, S.; Pape, H. C.; Hildebrand, F.

    2016-01-01

    Background Hypothermia has been discussed as playing a role in improving the early phase of systemic inflammation. However, information on the impact of hypothermia on the local inflammatory response is sparse. We therefore investigated the kinetics of local and systemic inflammation in the late posttraumatic phase after induction of hypothermia in an established porcine long-term model of combined trauma. Materials & Methods Male pigs (35 ± 5kg) were mechanically ventilated and monitored over the study period of 48 h. Combined trauma included tibia fracture, lung contusion, liver laceration and pressure-controlled hemorrhagic shock (MAP < 30 ± 5 mmHg for 90 min). After resuscitation, hypothermia (33°C) was induced for a period of 12 h (HT-T group) with subsequent re-warming over a period of 10 h. The NT-T group was kept normothermic. Systemic and local (fracture hematoma) cytokine levels (IL-6, -8, -10) and alarmins (HMGB1, HSP70) were measured via ELISA. Results Severe signs of shock as well as systemic and local increases of pro-inflammatory mediators were observed in both trauma groups. In general the local increase of pro- and anti-inflammatory mediator levels was significantly higher and prolonged compared to systemic concentrations. Induction of hypothermia resulted in a significantly prolonged elevation of both systemic and local HMGB1 levels at 48 h compared to the NT-T group. Correspondingly, local IL-6 levels demonstrated a significantly prolonged increase in the HT-T group at 48 h. Conclusion A prolonged inflammatory response might reduce the well-described protective effects on organ and immune function observed in the early phase after hypothermia induction. Furthermore, local immune response also seems to be affected. Future studies should aim to investigate the use of therapeutic hypothermia at different degrees and duration of application. PMID:27144532

  6. Relationship between retrograde coronary blood flow and the extent of no-reflow and infarct size in a porcine ischemia-reperfusion model.

    PubMed

    Stavrakis, Stavros; Terrovitis, John; Tsolakis, Elias; Drakos, Stavros; Dalianis, Argirios; Bonios, Michael; Koudoumas, Dimitrios; Malliaras, Konstantinos; Nanas, John

    2011-02-01

    Recanalization of an infarct-related artery does not predictably reflect tissue reperfusion. We examined the relationship between coronary blood flow (CBF) pattern during reperfusion and infarcted (IA) and no-reflow (NR) area in a porcine ischemia-reperfusion model. The mid-left anterior descending artery of 18 pigs was occluded for 1 h and reperfused for 2 h. CBF during reperfusion was measured with a transit-time ultrasound flowmeter, while systemic arterial and left atrial pressures were monitored. IA and NR were measured with triphenyl tetrazolium chloride and thioflavin staining, respectively. In 13 pigs, early systolic retrograde CBF developed within the first 30 min and persisted throughout reperfusion. No retrograde CBF was observed in five pigs. Mean retrograde CBF at 2 h of reperfusion predicted a larger IA (r = 0.71; p = 0.001). Time-to-development of retrograde CBF was inversely related to IA (r = -0.55; p = 0.019) and NR (r = -0.62; p = 0.006). A larger IA (OR 1.12, 95% CI 1.01-1.24, p = 0.037) and NR (OR 1.09, 95% CI 1.01-1.18, p = 0.037) predicted the presence of retrograde CBF. Retrograde CBF during recanalization of the infarct-related artery predicts IA and NR and might be used as an index of successful reperfusion at the tissue level. PMID:21153063

  7. Successful treatment of adult respiratory distress syndrome by histamine and prostaglandin blockade in a porcine Pseudomonas model.

    PubMed

    Sielaff, T D; Sugerman, H J; Tatum, J L; Blocher, C R

    1987-08-01

    , ibuprofen, is effective and essential in the treatment of hypoxemia, early pulmonary hypertension, and pulmonary microvascular injury in this fulminant model of porcine Pseudomonas ARDS. PMID:3112984

  8. Monitoring the influence of compression therapy on pathophysiology and structure of a swine scar model using multispectral imaging system

    NASA Astrophysics Data System (ADS)

    Ghassemi, Pejhman; Travis, Taryn E.; Shuppa, Jeffrey W.; Moffatt, Lauren T.; Ramella-Romana, Jessica C.

    2014-03-01

    Scar contractures can lead to significant reduction in function and inhibit patients from returning to work, participating in leisure activities and even render them unable to provide care for themselves. Compression therapy has long been a standard treatment for scar prevention but due to the lack of quantifiable metrics of scar formation scant evidence exists of its efficacy. We have recently introduced a multispectral imaging system to quantify pathophysiology (hemoglobin, blood oxygenation, melanin, etc) and structural features (roughness and collagen matrix) of scar. In this study, hypertrophic scars are monitored in-vivo in a porcine model using the imaging system to investigate influence of compression therapy on its quality.

  9. Effect of age and maternal antibodies on the systemic and mucosal immune response after neonatal immunization in a porcine model

    PubMed Central

    Guzman-Bautista, Edgar R; Garcia-Ruiz, Carlos E; Gama-Espinosa, Alicia L; Ramirez-Estudillo, Carmen; Rojas-Gomez, Oscar I; Vega-Lopez, Marco A

    2014-01-01

    Newborn mammals are highly susceptible to respiratory infections. Although maternal antibodies (MatAb) offer them some protection, they may also interfere with their systemic immune response to vaccination. However, the impact of MatAb on the neonatal mucosal immune response remains incompletely described. This study was performed to determine the effect of ovalbumin (OVA)-specific MatAb on the anti-OVA antibody response in sera, nasal secretions and saliva from specific pathogen-free Vietnamese miniature piglets immunized at 7 or 14 days of age. Our results demonstrated that MatAb increased antigen-specific IgA and IgG responses in sera, and transiently enhanced an early secretory IgA response in nasal secretions of piglets immunized at 7 days of age. In contrast, we detected a lower mucosal (nasal secretion and saliva) anti-OVA IgG response in piglets with MatAb immunized at 14 days of age, compared with piglets with no MatAb, suggesting a modulatory effect of antigen-specific maternal factors on the isotype transfer to the mucosal immune exclusion system. In our porcine model, we demonstrated that passive maternal immunity positively modulated the systemic and nasal immune responses of animals immunized early in life. Our results, therefore, open the possibility of inducing systemic and respiratory mucosal immunity in the presence of MatAb through early vaccination. PMID:24754050

  10. Synthesis and anti-staphylococcal activity of TiO2 nanoparticles and nanowires in ex vivo porcine skin model.

    PubMed

    Nataraj, Namrata; Anjusree, G S; Madhavan, Asha Anish; Priyanka, P; Sankar, Deepthi; Nisha, N; Lakshmi, S V; Jayakumar, R; Balakrishnan, Avinash; Biswas, Raja

    2014-05-01

    Staphylococcus aureus is one of the major causes of skin and soft tissue infections. In this study we compared the antimicrobial activity of two different TiO2 nanoformulations against Staphylococcus aureus. We synthesized TiO2 nanoparticles of approximately 80 nm diameter and TiO2 nanowires of approximately 100 nm diameter. Both nanoformulations possess anti-microbial activity; were non-hemolytic and cytocompatible. However, the anti-staphylococcal activity of TiO2 nanowires was better than the nanoparticles. In broth culture, growth of S. aureus was only partially inhibited by 2% and 4 wt% TiO2 nanoparticles and completely inhibited by TiO2 nanowires till 24 h. TiO2 nanowires treated S. aureus cells exhibits diminished membrane potential than nanoparticle treated cells. The anti-microbial properties of both TiO2 nanoformulations were validated using ex vivo porcine skin model which supplements the in vitro assays. Anti-bacterial activity of the TiO2 nanowires were also validated against multi drug resistant pathogenic strains of S. aureus, showing the clinical potency of the TiO2 nanowires compared to its nanoparticles. PMID:24734539

  11. Enamel pathology resulting from loss of function in the cystic fibrosis transmembrane conductance regulator in a porcine animal model.

    PubMed

    Chang, Eugene H; Lacruz, Rodrigo S; Bromage, Timothy G; Bringas, Pablo; Welsh, Michael J; Zabner, Joseph; Paine, Michael L

    2011-01-01

    Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR), a phosphorylation- and ATP-regulated anion channel. CFTR expression and activity is frequently associated with an anion exchanger (AE) such as AE2 coded by the Slc4a2 gene. Mice null for Cftr and mice null for Slc4a2 have enamel defects, and there are some case reports of enamel anomalies in patients with CF. In this study we demonstrate that both Cftr and AE2 expression increased significantly during the rat enamel maturation stage versus the earlier secretory stage (5.6- and 2.9-fold, respectively). These qPCR data im- ply that there is a greater demand for Cl(-) and bicarbonate (HCO₃⁻) transport during the maturation stage of enamel formation, and that this is, at least in part, provided by changes in Cftr and AE2 expression. In addition, the enamel phenotypes of 2 porcine models of CF, CFTR-null, and CFTR-ΔF508 have been examined using backscattered electron microscopy in a scanning electron microscope. The enamel of newborn CFTR-null and CFTR-ΔF508 animals is hypomineralized. Together, these data provide a molecular basis for interpreting enamel disease associated with disruptions to CFTR and AE2 expression. PMID:21525720

  12. Enamel Pathology Resulting from Loss of Function in the Cystic Fibrosis Transmembrane Conductance Regulator in a Porcine Animal Model

    PubMed Central

    Chang, Eugene H.; Lacruz, Rodrigo S.; Bromage, Timothy G.; Bringas, Pablo; Welsh, Michael J.; Zabner, Joseph; Paine, Michael L.

    2011-01-01

    Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR), a phosphorylation- and ATP-regulated anion channel. CFTR expression and activity is frequently associated with an anion exchanger (AE) such as AE2 coded by the Slc4a2 gene. Mice null for Cftr and mice null for Slc4a2 have enamel defects, and there are some case reports of enamel anomalies in patients with CF. In this study we demonstrate that both Cftr and AE2 expression increased significantly during the rat enamel maturation stage versus the earlier secretory stage (5.6- and 2.9-fold, respectively). These qPCR data im- ply that there is a greater demand for Cl– and bicarbonate (HCO3–) transport during the maturation stage of enamel formation, and that this is, at least in part, provided by changes in Cftr and AE2 expression. In addition, the enamel phenotypes of 2 porcine models of CF, CFTR-null, and CFTR-ΔF508 have been examined using backscattered electron microscopy in a scanning electron microscope. The enamel of newborn CFTR-null and CFTR-ΔF508 animals is hypomineralized. Together, these data provide a molecular basis for interpreting enamel disease associated with disruptions to CFTR and AE2 expression. PMID:21525720

  13. ICG angiography predicts burn scarring within 48 h of injury in a porcine vertical progression burn model.

    PubMed

    Fourman, Mitchell S; McKenna, Peter; Phillips, Brett T; Crawford, Laurie; Romanelli, Filippo; Lin, Fubao; McClain, Steve A; Khan, Sami U; Dagum, Alexander B; Singer, Adam J; Clark, Richard A F

    2015-08-01

    The current standard of care in determining the need to excise and graft a burn remains with the burn surgeon, whose clinical judgment is often variable. Prior work suggests that minimally invasive perfusion technologies are useful in burn prognostication. Here we test the predictive capabilities of Laser Doppler Imaging (LDI) and indocyanine green dye (ICG) angiography in the prediction of burn scarring 28 days after injury using a previously validated porcine burn model that shows vertical progression injury. Twelve female Yorkshire swine were burned using a 2.5 × 2.5 cm metal bar at variable temperature and application times to create distinct burn depths. Six animals (48 injuries total) each were analyzed with LDI or ICG angiography at 1, 24, 48, and 72 h following injury. A linear regression was then performed correlating perfusion measurements against wound contraction at 28 days after injury. ICG angiography showed a peak linear correlate (r(2)) of .63 (95% CI .34 to .92) at 48 h after burn. This was significantly different from the LDI linear regression (p < .05), which was measured at r(2) of .20 (95% CI .02 to .39). ICG angiography linear regression was superior to LDI at all timepoints. Findings suggest that ICG angiography may have significant potential in the prediction of long-term burn outcomes. PMID:25499407

  14. Hepatic and Splenic Stiffness Augmentation Assessed with MR Elastography in an in vivo Porcine Portal Hypertension Model

    PubMed Central

    Yin, Meng; Kolipaka, Arunark; Woodrum, David A.; Glaser, Kevin J.; Romano, Anthony J; Manduca, Armando; Talwalkar, Jayant A.; Araoz, Philip A.; McGee, Kiaran P.; Anavekar, Nandan S.; Ehman, Richard L.

    2013-01-01

    Purpose To investigate the influence of portal pressure on the shear stiffness of the liver and spleen in a well-controlled in vivo porcine model with MR Elastography (MRE). A significant correlation between portal pressure and tissue stiffness could be used to noninvasively assess increased portal venous pressure (portal hypertension), which is a frequent clinical condition caused by cirrhosis of the liver and is responsible for the development of many lethal complications. Materials and Methods During multiple intra-arterial infusions of Dextran-40 in three adult domestic pigs in vivo, 3-D abdominal MRE was performed with left ventricle and portal catheters measuring blood pressure simultaneously. Least-squares linear regressions were used to analyze the relationship between tissue stiffness and portal pressure. Results Liver and spleen stiffness have a dynamic component that increases significantly following an increase in portal or left ventricular pressure. Correlation coefficients with the linear regressions between stiffness and pressure exceeded 0.8 in most cases. Conclusion The observed stiffness-pressure relationship of the liver and spleen could provide a promising noninvasive method for assessing portal pressure. Using MRE to study the tissue mechanics associated with portal pressure may provide new insights into the natural history and pathophysiology of hepatic diseases and may have significant diagnostic value in the future. PMID:23418135

  15. Integrating model abstraction into monitoring strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed and performed to investigate the opportunities and benefits of integrating model abstraction techniques into monitoring strategies. The study focused on future applications of modeling to contingency planning and management of potential and actual contaminant release sites wi...

  16. Implementation of a 3D porcine lumbar finite element model for the simulation of monolithic spinal rods with variable flexural stiffness.

    PubMed

    Brummund, Martin; Brailovski, Vladimir; Facchinello, Yann; Petit, Yvan; Mac-Thiong, Jean-Marc

    2015-08-01

    Monolithic superelastic-elastoplastic spinal rods (MSER) are promising candidates to provide (i) dynamic stabilisation in spinal segments prone to mechanical stress concentration and adjacent segment disease and (ii) to provide fusion-ready stabilization in spinal segments at risk of implant failure. However, the stiffness distributions along the rod's longitudinal axis that best meet clinical requirements remain unknown. The present study is part of a mixed numerical experimental research project and aims at the implementation of a 3D finite element model of the porcine lumbar spine to study the role of MSER material properties and stiffness distributions on the intradiscal pressure distribution in the adjacent segment. In this paper, preliminary intradiscal pressure predictions obtained at one functional spinal unit are presented. Due to a lack of porcine material property data, these predictions were obtained on the basis of uncalibrated human vertebral disc data which were taken from the literature. The results indicate that human annulus and nucleus data predict experimental porcine in vivo and in vitro data reasonably well for the compressive forces of varying magnitudes. PMID:26736412

  17. Resuscitation with Valproic Acid Alters Inflammatory Genes in a Porcine Model of Combined Traumatic Brain Injury and Hemorrhagic Shock.

    PubMed

    Bambakidis, Ted; Dekker, Simone E; Sillesen, Martin; Liu, Baoling; Johnson, Craig N; Jin, Guang; de Vries, Helga E; Li, Yongqing; Alam, Hasan B

    2016-08-15

    Traumatic brain injury and hemorrhagic shock (TBI+HS) elicit a complex inflammatory response that contributes to secondary brain injury. There is currently no proven pharmacologic treatment for TBI+HS, but modulation of the epigenome has been shown to be a promising strategy. The aim of this study was to investigate whether valproic acid (VPA), a histone deacetylase inhibitor, modulates the expression of cerebral inflammatory gene profiles in a large animal model of TBI+HS. Ten Yorkshire swine were subjected to computer-controlled TBI+HS (40% blood volume). After 2 h of shock, animals were resuscitated with Hextend (HEX) or HEX+VPA (300 mg/kg, n = 5/group). Six hours after resuscitation, brains were harvested, RNA was isolated, and gene expression profiles were measured using a porcine microarray. Ingenuity Pathway Analysis® (IPA), gene ontology (GO), Parametric Gene Set Enrichment Analysis (PGSEA), and DAVID (Database for Annotation, Visualization, and Integrated Discovery) were used for pathway analysis. Key microarray findings were verified using real-time polymerase chain reaction (PCR). IPA analysis revealed that VPA significantly down-regulated the complement system (p < 0.001), natural killer cell communication (p < 0.001), and dendritic cell maturation (p < 0.001). DAVID analysis indicated that a cluster of inflammatory pathways held the highest rank and gene enrichment score. Real-time PCR data confirmed that VPA significantly down-expressed genes that ultimately regulate nuclear factor-kB (NF-kB)-mediated production of cytokines, such as TYROBP, TREM2, CCR1, and IL-1β. This high-throughput analysis of cerebral gene expression shows that addition of VPA to the resuscitation protocol significantly modulates the expression of inflammatory pathways in a clinically realistic model of TBI+HS. PMID:26905959

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

    PubMed

    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. PMID:26837238

  19. Efficacy of a bio-electric dressing in healing deep, partial-thickness wounds using a porcine model .

    PubMed

    Harding, Andrew C; Gil, Joel; Valdes, Jose; Solis, Michael; Davis, Stephen C

    2012-09-01

    Numerous physical modalities have been used in attempts to augment the healing process, including ultrasound, low- energy light therapy, and electrical stimulation (ES). ES has been shown to benefit tissue repair in a variety of wound types, but variations in study designs, administration, and parameters render its application in clinical practice somewhat unconventional. A dressing was designed to generate an electric potential of 0.6 V to 0.7 V in the presence of moisture, thereby delivering a sustained micro-current without the need for an external power source. The purpose of this study was to examine the effects of this bio-electric dressing (BED) on deep, partial-thickness wounds using six female specific pathogen-free animals and a well established porcine model for wound healing. Wounds (10 mm x 7 mm x 0.5 mm) were created in paravertebral and thoracic areas of these animals using a specialized electrokeratome and covered with the active polyester BED and a polyurethane film dressing (n = 30) (treatment) or an inactive polyester and film dressing (n = 30). Using an epidermal migration assay, wounds were assessed daily from day 4 through day 8 post-wounding. Differences in the proportion of wounds healed were statistically significant (P <0.001) on days 5 and 6 post-wounding. These results show BED is more effective than a control dressing treatment with moisture-retentive dressings in this animal model. Controlled clinical studies are warranted to elucidate the potential clinical implications of this treatment modality. PMID:22933701

  20. Geophysical Models for Nuclear Explosion Monitoring

    SciTech Connect

    Pasyanos, M E; Walter, W R; Flanagan, M

    2003-07-16

    Geophysical models are increasingly recognized as an important component of regional calibrations for seismic monitoring. The models can be used to predict geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. While empirical measurements of these geophysical parameters might be preferred, in aseismic regions or regions without seismic stations, this data might not exist. In these cases, models represent a 'best guess' of the seismic properties in a region, which improves on global models such as the PREM (Preliminary Reference Earth Model) or the IASPEI (International Association of Seismology and Physics of the Earth's Interior) models. The model-based predictions can also serve as a useful background for the empirical measurements by removing trends in the data. To this end, Lawrence Livermore National Laboratory (LLNL) has developed the WENA model for Western Eurasia and North Africa. This model is constructed using a regionalization of several dozen lithospheric (crust and uppermost mantle) models, combined with the Laske sediment model and 3SMAC upper mantle. We have evaluated this model using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis. Similarly, Los Alamos National Laboratory (LANL) has developed a geophysical model for East Asia, allowing LLNL/LANL to construct a model for all of Eurasia and North Africa. These models continue to evolve as new and updated datasets are used to critically assess the predictive powers of the model. Research results from this meeting and other reports and papers can be used to update and refine the regional boundaries and regional models. A number of other groups involved in monitoring have also developed geophysical models. As these become available, we will be assessing the models and their constitutive components for their suitability for inclusion in the National Nuclear Security

  1. System monitoring and diagnosis with qualitative models

    NASA Technical Reports Server (NTRS)

    Kuipers, Benjamin

    1991-01-01

    A substantial foundation of tools for model-based reasoning with incomplete knowledge was developed: QSIM (a qualitative simulation program) and its extensions for qualitative simulation; Q2, Q3 and their successors for quantitative reasoning on a qualitative framework; and the CC (component-connection) and QPC (Qualitative Process Theory) model compilers for building QSIM QDE (qualitative differential equation) models starting from different ontological assumptions. Other model-compilers for QDE's, e.g., using bond graphs or compartmental models, have been developed elsewhere. These model-building tools will support automatic construction of qualitative models from physical specifications, and further research into selection of appropriate modeling viewpoints. For monitoring and diagnosis, plausible hypotheses are unified against observations to strengthen or refute the predicted behaviors. In MIMIC (Model Integration via Mesh Interpolation Coefficients), multiple hypothesized models of the system are tracked in parallel in order to reduce the 'missing model' problem. Each model begins as a qualitative model, and is unified with a priori quantitative knowledge and with the stream of incoming observational data. When the model/data unification yields a contradiction, the model is refuted. When there is no contradiction, the predictions of the model are progressively strengthened, for use in procedure planning and differential diagnosis. Only under a qualitative level of description can a finite set of models guarantee the complete coverage necessary for this performance. The results of this research are presented in several publications. Abstracts of these published papers are presented along with abtracts of papers representing work that was synergistic with the NASA grant but funded otherwise. These 28 papers include but are not limited to: 'Combined qualitative and numerical simulation with Q3'; 'Comparative analysis and qualitative integral representations

  2. GULF OF MEXICO HYPOXIA MONITORING AND MODELING

    EPA Science Inventory

    Greene, Richard M. and Russell G. Kreis. In press. Gulf of Mexico Hypoxia Monitoring and Modeling (Abstract). To be presented at the EPA Science Forum: Healthy Communities and Ecosystems, 1-3 June 2004, Washington, DC. 1 p. (ERL,GB R990).

    Oxygen-depleted or hypoxic bottom...

  3. Monitoring issues from a modeling perspective

    NASA Technical Reports Server (NTRS)

    Mahlman, Jerry D.

    1993-01-01

    Recognition that earth's climate and biogeophysical conditions are likely changing due to human activities has led to a heightened awareness of the need for improved long-term global monitoring. The present long-term measurement efforts tend to be spotty in space, inadequately calibrated in time, and internally inconsistent with respect to other instruments and measured quantities. In some cases, such as most of the biosphere, most chemicals, and much of the ocean, even a minimal monitoring program is not available. Recently, it has become painfully evident that emerging global change issues demand information and insights that the present global monitoring system simply cannot supply. This is because a monitoring system must provide much more than a statement of change at a given level of statistical confidence. It must describe changes in diverse parts of the entire earth system on regional to global scales. It must be able to provide enough input to allow an integrated physical characterization of the changes that have occurred. Finally, it must allow a separation of the observed changes into their natural and anthropogenic parts. The enormous policy significance of global change virtually guarantees an unprecedented level of scrutiny of the changes in the earth system and why they are happening. These pressures create a number of emerging challenges and opportunities. For example, they will require a growing partnership between the observational programs and the theory/modeling community. Without this partnership, the scientific community will likely fall short in the monitoring effort. The monitoring challenge before us is not to solve the problem now, but rather to set appropriate actions in motion so as to create the required framework for solution. Each individual piece needs to establish its role in the large problem and how the required interactions are to take place. Below, we emphasize some of the needs and opportunities that could and should be

  4. Monitoring Microcirculatory Blood Flow with a New Sublingual Tonometer in a Porcine Model of Hemorrhagic Shock

    PubMed Central

    Palágyi, Péter; Kaszaki, József; Rostás, Andrea; Érces, Dániel; Németh, Márton; Boros, Mihály; Molnár, Zsolt

    2015-01-01

    Tissue capnometry may be suitable for the indirect evaluation of regional hypoperfusion. We tested the performance of a new sublingual capillary tonometer in experimental hemorrhage. Thirty-six anesthetized, ventilated mini pigs were divided into sham-operated (n = 9) and shock groups (n = 27). Hemorrhagic shock was induced by reducing mean arterial pressure (MAP) to 40 mmHg for 60 min, after which fluid resuscitation started aiming to increase MAP to 75% of the baseline value (60–180 min). Sublingual carbon-dioxide partial pressure was measured by tonometry, using a specially coiled silicone rubber tube. Mucosal red blood cell velocity (RBCV) and capillary perfusion rate (CPR) were assessed by orthogonal polarization spectral (OPS) imaging. In the 60 min shock phase a significant drop in cardiac index was accompanied by reduction in sublingual RBCV and CPR and significant increase in the sublingual mucosal-to-arterial PCO2 gap (PSLCO2 gap), which significantly improved during the 120 min resuscitation phase. There was significant correlation between PSLCO2 gap and sublingual RBCV (r = −0.65, p < 0.0001), CPR (r = −0.64, p < 0.0001), central venous oxygen saturation (r = −0.50, p < 0.0001), and central venous-to-arterial PCO2 difference (r = 0.62, p < 0.0001). This new sublingual tonometer may be an appropriate tool for the indirect evaluation of circulatory changes in shock. PMID:26504837

  5. Monitoring Microcirculatory Blood Flow with a New Sublingual Tonometer in a Porcine Model of Hemorrhagic Shock.

    PubMed

    Palágyi, Péter; Kaszaki, József; Rostás, Andrea; Érces, Dániel; Németh, Márton; Boros, Mihály; Molnár, Zsolt

    2015-01-01

    Tissue capnometry may be suitable for the indirect evaluation of regional hypoperfusion. We tested the performance of a new sublingual capillary tonometer in experimental hemorrhage. Thirty-six anesthetized, ventilated mini pigs were divided into sham-operated (n = 9) and shock groups (n = 27). Hemorrhagic shock was induced by reducing mean arterial pressure (MAP) to 40 mmHg for 60 min, after which fluid resuscitation started aiming to increase MAP to 75% of the baseline value (60-180 min). Sublingual carbon-dioxide partial pressure was measured by tonometry, using a specially coiled silicone rubber tube. Mucosal red blood cell velocity (RBCV) and capillary perfusion rate (CPR) were assessed by orthogonal polarization spectral (OPS) imaging. In the 60 min shock phase a significant drop in cardiac index was accompanied by reduction in sublingual RBCV and CPR and significant increase in the sublingual mucosal-to-arterial PCO2 gap (PSLCO2 gap), which significantly improved during the 120 min resuscitation phase. There was significant correlation between PSLCO2 gap and sublingual RBCV (r = -0.65, p < 0.0001), CPR (r = -0.64, p < 0.0001), central venous oxygen saturation (r = -0.50, p < 0.0001), and central venous-to-arterial PCO2 difference (r = 0.62, p < 0.0001). This new sublingual tonometer may be an appropriate tool for the indirect evaluation of circulatory changes in shock. PMID:26504837

  6. Quantitative analysis of Porcine Reproductive and Respiratory Syndrome (PRRS) viremia profiles from experimental infection: a statistical modelling approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine reproductive and respiratory syndrome (PRRS) is the most economically significant viral disease facing the global swine industry. Viremia profiles of PRRS virus challenged pigs reflect the severity and progression of the infection within the host and provide crucial information for subsequen...

  7. Ultrasound-guided tissue fractionation by high intensity focused ultrasound in an in vivo porcine liver model.

    PubMed

    Khokhlova, Tatiana D; Wang, Yak-Nam; Simon, Julianna C; Cunitz, Bryan W; Starr, Frank; Paun, Marla; Crum, Lawrence A; Bailey, Michael R; Khokhlova, Vera A

    2014-06-01

    The clinical use of high intensity focused ultrasound (HIFU) therapy for noninvasive tissue ablation has been recently gaining momentum. In HIFU, ultrasound energy from an extracorporeal source is focused within the body to ablate tissue at the focus while leaving the surrounding organs and tissues unaffected. Most HIFU therapies are designed to use heating effects resulting from the absorption of ultrasound by tissue to create a thermally coagulated treatment volume. Although this approach is often successful, it has its limitations, such as the heat sink effect caused by the presence of a large blood vessel near the treatment area or heating of the ribs in the transcostal applications. HIFU-induced bubbles provide an alternative means to destroy the target tissue by mechanical disruption or, at its extreme, local fractionation of tissue within the focal region. Here, we demonstrate the feasibility of a recently developed approach to HIFU-induced ultrasound-guided tissue fractionation in an in vivo pig model. In this approach, termed boiling histotripsy, a millimeter-sized boiling bubble is generated by ultrasound and further interacts with the ultrasound field to fractionate porcine liver tissue into subcellular debris without inducing further thermal effects. Tissue selectivity, demonstrated by boiling histotripsy, allows for the treatment of tissue immediately adjacent to major blood vessels and other connective tissue structures. Furthermore, boiling histotripsy would benefit the clinical applications, in which it is important to accelerate resorption or passage of the ablated tissue volume, diminish pressure on the surrounding organs that causes discomfort, or insert openings between tissues. PMID:24843132

  8. Dose reduction assessment in dynamic CT myocardial perfusion imaging in a porcine balloon-induced-ischemia model

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    We investigated the use of an advanced hybrid iterative reconstruction (IR) technique (iDose4, Philips Health- care) for low dose dynamic myocardial CT perfusion (CTP) imaging. A porcine model was created to mimic coronary stenosis through partial occlusion of the left anterior descending (LAD) artery with a balloon catheter. The severity of LAD occlusion was adjusted with FFR measurements. Dynamic CT images were acquired at end-systole (45% R-R) using a multi-detector CT (MDCT) scanner. Various corrections were applied to the acquired scans to reduce motion and imaging artifacts. Absolute myocardial blood flow (MBF) was computed with a deconvolution-based approach using singular value decomposition (SVD). We compared a high and a low dose radiation protocol corresponding to two different tube-voltage/tube-current combinations (80kV p/100mAs and 120kV p/150mAs). The corresponding radiation doses for these protocols are 7.8mSv and 34.3mSV , respectively. The images were reconstructed using conventional FBP and three noise-reduction strengths of the IR method, iDose. Flow contrast-to-noise ratio, CNRf, as obtained from MBF maps, was used to quantitatively evaluate the effect of reconstruction on contrast between normal and ischemic myocardial tissue. Preliminary results showed that the use of iDose to reconstruct low dose images provide better or comparable CNRf to that of high dose images reconstructed with FBP, suggesting significant dose savings. CNRf was improved with the three used levels of iDose compared to FBP for both protocols. When using the entire 4D dynamic sequence for MBF computation, a 77% dose reduction was achieved, while considering only half the scans (i.e., every other heart cycle) allowed even further dose reduction while maintaining relatively higher CNRf.

  9. The influence of acute unloading on left ventricular strain and strain rate by speckle tracking echocardiography in a porcine model.

    PubMed

    Dahle, Geir Olav; Stangeland, Lodve; Moen, Christian Arvei; Salminen, Pirjo-Riitta; Haaverstad, Rune; Matre, Knut; Grong, Ketil

    2016-05-15

    Noninvasive measurements of myocardial strain and strain rate by speckle tracking echocardiography correlate to cardiac contractile state but also to load, which may weaken their value as indices of inotropy. In a porcine model, we investigated the influence of acute dynamic preload reductions on left ventricular strain and strain rate and their relation to the pressure-conductance catheter-derived preload recruitable stroke work (PRSW) and peak positive first derivative of left ventricular pressure (LV-dP/dtmax). Speckle tracking strain and strain rate in the longitudinal, circumferential, and radial directions were measured during acute dynamic reductions of end-diastolic volume during three different myocardial inotropic states. Both strain and strain rate were sensitive to unloading of the left ventricle (P < 0.001), but the load dependency for strain rate was modest compared with strain. Changes in longitudinal and circumferential strain correlated more strongly to changes in end-diastolic volume (r = -0.86 and r = -0.72) than did radial strain (r = 0.35). Longitudinal, circumferential, and radial strain significantly correlated with LV-dP/dtmax (r = -0.53, r = -0.46, and r = 0.86), whereas only radial strain correlated with PRSW (r = 0.55). Strain rate in the longitudinal, circumferential and radial direction significantly correlated with both PRSW (r = -0.64, r = -0.58, and r = 0.74) and LV-dP/dtmax (r = -0.95, r = -0.70, and r = 0.85). In conclusion, the speckle tracking echocardiography-derived strain rate is more robust to dynamic ventricular unloading than strain. Longitudinal and circumferential strain could not predict load-independent contractility. Strain rates, and especially in the radial direction, are good predictors of preload-independent inotropic markers derived from conductance catheter. PMID:26968547

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

    PubMed Central

    Terry, Christi M.; Zhuplatov, Ilya; He, Yuxia; Wun, Tze-Chein; Kim, Seong-Eun; Cheung, Alfred K.

    2015-01-01

    Background 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. Methods 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. Results 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

  11. A Comparison between splenic fossa and subhepatic fossa auxiliary partial heterotopic liver transplantation in a porcine model.

    PubMed

    Ai, Lemin; Liang, Xiao; Wang, Zhifei; Shen, Jie; Yu, Feiyan; Xie, Limei; Pan, Yongming; Lin, Hui

    2016-06-01

    To test the alternative possible locations for the placement of a liver graft and the relevant surgical technique issues, we developed a porcine model of auxiliary partial heterotopic liver transplantation (APHLT) and evaluated the difference between 2 styles of liver transplantation, either subhepatic fossa or splenic fossa APHLT, by comparing survival and biochemical indexes. Thirty-eight miniature pigs were randomly divided into 2 groups. A left hemihepatic graft without the middle hepatic vein (HV) was procured from the living donor. In group A (n = 9), an 8 mm diameter polytetrafluoroethylene (PTFE) graft approximately 2.5 cm long was connected to the left HV while another PTFE graft of the same size was connected to the left portal vein (PV). The liver graft was implanted in the right subhepatic fossa following splenectomy and right nephrectomy. In group B (n = 10), a PTFE graft of the same size was connected to the left HV while the liver graft was implanted in the splenic fossa following splenectomy and left nephrectomy. Survival rate and complications were observed at 2 weeks after transplantation. Data were collected from 5 animals in group A and 6 animals in group B that survived longer than 2 weeks. The liver function and renal function of the recipients returned to normal at 1 week after surgery in both groups. Eighty-eight percent (14/16) of the PTFE grafts remained patent at 2 weeks after surgery, but 44% of the PTFE grafts (7/16) developed mural thrombus. No significant differences in the survival rate and biochemistry were found between the 2 groups. In conclusion, the splenic fossa APHLT can achieve beneficial outcomes similar to the subhepatic fossa APHLT in miniature pigs, although it also has a high morbidity rate due to hepatic artery thrombosis, PV thrombosis, and PTEF graft mural thrombus formation. Liver Transplantation 22 812-821 2016 AASLD. PMID:26785299

  12. Comparison of Pull-out Strength for Different Bone Block Length in a Porcine Anterior Cruciate Ligament Model

    PubMed Central

    Posner, Matthew; Owens, Brett; Johnson, Paul; Masciello, Noreen; Cameron, Kenneth; Roach, Christopher; Svoboda, Steven; Floersheim, Bruce

    2014-01-01

    Background: Bone block length for bone–patellar tendon–bone (BPTB) anterior cruciate ligament (ACL) reconstruction has traditionally been 25 mm in length. The previous surgical technique did not require the surgeon to pay particular attention to the length of the bone block, and therefore, there is scant evidence in the literature describing ideal lengths. With the gaining popularity of accessory medial portal drilling of the femoral tunnel, concerns with tunnel length and graft shuttling have surfaced. Newer techniques have advised shortening of the femoral bone block to accommodate the shorter tunnel and for ease of bone block manipulation into the aperture of the tunnel. Purpose: To compare the effects of bone block length on the pull-out strength of patellar tendon grafts using metal interference screws in a porcine ACL reconstruction model. The hypothesis was that the pull-out strength of each length of bone block under cyclic and ultimate load to failure testing would surpass the physiologic loads experienced by a normal ACL. Study Design: Controlled laboratory study. Methods: This study used 27 unmatched porcine femurs and BPTB constructs. Specimens were randomly assigned to a 10-, 15-, or 20-mm bone block reconstruction and a cycle load of 100, 500, or 1000 cycles. This resulted in 9 specimen groups with 3 specimens in each group. A central composite design (CCD) for the test matrix was selected, as this was optimum for requiring relatively few experiments while still exploring the complete range of interest for 2 independent variables. Each reconstruction used a 7 × 20–mm titanium interference screw. All reconstructions were performed on the femoral side using 10-mm-wide patellar tendon grafts, and tensile tests were performed. The loading protocol started with a 20-N preload, then cyclic testing to the appropriate number of cycles in the elastic region between 50 and 150 N at a strain rate of 200 mm/min, and then ended with ultimate load

  13. Myocardial ATP hydrolysis rates in vivo: a porcine model of pressure overload-induced hypertrophy

    PubMed Central

    Xiong, Qiang; Zhang, Pengyuan; Guo, Jing; Swingen, Cory; Jang, Albert

    2015-01-01

    Left ventricular (LV) hypertrophy (LVH) and congestive heart failure are accompanied by changes in myocardial ATP metabolism. However, the rate of ATP hydrolysis cannot be measured in the in vivo heart with the conventional techniques. Here, we used a double-saturation phosphorous-31 magnetic resonance spectroscopy-magnetization saturation transfer protocol to monitor ATP hydrolysis rate in swine hearts as the hearts became hypertrophic in response to aortic banding (AOB). Animals that underwent AOB (n = 22) were compared with animals that underwent sham surgery (n = 8). AOB induced severe LVH (cardiac MRI). LV function (ejection fraction and systolic thickening fraction) declined significantly, accompanied by deferent levels of pericardial effusion, and wall stress increased in aorta banded animals at week 1 after AOB, suggesting acute heart failure, which recovered by week 8 when concentric LVH restored LV wall stresses. Severe LV dysfunction was accompanied by corresponding declines in myocardial bioenergetics (phosphocreatine-to-ATP ratio) and in the rate of ATP production via creatine kinase at week 1. For the first time, the same linear relationships of the rate increase of the constants of the ATP hydrolysis rate (kATP→Pi) vs. the LV rate-pressure product increase during catecholamine stimulation were observed in vivo in both normal and LVH hearts. Collectively, these observations demonstrate that the double-saturation, phosphorous-31 magnetic resonance spectroscopy-magnetization saturation transfer protocol can accurately monitor myocardial ATP hydrolysis rate in the hearts of living animals. The severe reduction of LV chamber function during the acute phase of AOB is accompanied by the decrease of myocardial bioenergetic efficiency, which recovers as the compensated LVH restores the LV wall stresses. PMID:26024682

  14. Novel porcine repetitive elements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An analysis of 220 fully sequenced porcine BACs generated by the Comparative Vertebrate Sequencing Initiative (http://www.nisc.nih.gov/) revealed 27 distinct, novel porcine repetitive elements ranging in length from 55 to 1059 nucleotides. This set of fully sequenced BACs covers approximately 1% of...

  15. Cloning and characterization of porcine resistin gene.

    PubMed

    Dai, M H; Xia, T; Chen, X D; Gan, L; Feng, S Q; Qiu, H; Peng, Y; Yang, Z Q

    2006-02-01

    Resistin is a member of resistin-like molecules (RELMs) and a hormone secreted from mature adipocytes in rodents and leukocytes in human. We now report the cloning and characterization of the full-length porcine resistin cDNA and gene. Sequence analysis indicated that the pig resistin cDNA sequence had an open reading frame of 330 bp encoding a 12 kDa protein of 109 amino acids. The deduced amino acid sequence showed 75.2% identity to the human resistin. The porcine resistin gene was composed of four exons and had exactly the same exon structure as the human resistin gene. The tissue distribution of porcine resistin mRNA was assessed by semi-quantitative RT-PCR. Resistin gene expression was the highest in porcine leukocytes and low in adipose tissue. Resistin protein could be detected in porcine serum by western blotting and it circulated in serum as dimers and trimers. We provided the first evidence that resistin was abundantly expressed in porcine leukocytes and had an expression pattern similar to that in human resistin mRNA and protein. This suggests that the pig may be a suitable animal model for studying the function of resistin in human insulin resistance. PMID:16023825

  16. Monitoring and Modelling Lakes and Coastal Environments

    NASA Astrophysics Data System (ADS)

    Odada, Eric

    2009-01-01

    The monitoring and modeling of lakes and coastal environments is becoming ever more important, particularly because these environments bear heavy loads in terms of human population, and their resources are critical to the livelihoods and well-being of coastal inhabitants and ecosystems. Monitoring and Modelling Lakes and Coastal Environments is a collection of 18 papers arising from the Lake 2004 International Conference on Conservation, Restoration and Management of Lakes and Coastal Wetlands, held in Bhubaneswar, Orissa, India, 9-13 December 2004. Consequently, 15 of the papers are concerned with studies on the Indian subcontinent, and many of the papers focus on India's Lake Chilika, the site of a special session during the conference. Two papers concern Japan, and one focuses on North America's Great Lakes region. Although the book has a regional bias, the replication of best practices that can be drawn from these studies may be useful for an international audience.

  17. Degradation Modelling for Health Monitoring Systems

    NASA Astrophysics Data System (ADS)

    Stetter, R.; Witczak, M.

    2014-12-01

    Condition-monitoring plays an increasingly important role for technical processes in order to improve reliability, availability, maintenance and lifetime of equipment. With increasing demands for efficiency and product quality, plus progress in the integration of automatic control systems in high-cost mechatronic and critical safety processes, the field of health monitoring is gaining interest. A similar research field is concerned with an estimation of the remaining useful life. A central question in these fields is the modelling of degradation; degradation is a process of a gradual and irreversible accumulation of damage which will finally result in a failure of the system. This paper is based on a current research project and explores various degradation modelling techniques. These results are explained on the basis of an industrial product - a system for the generation of health status information for pump systems. The result of this fuzzy-logic based system is a single number indicating the current health of a pump system.

  18. Porcine acute liver failure model established by two-phase surgery and treated with hollow fiber bioartificial liver support system

    PubMed Central

    Gao, Yi; Mu, Ning; Xu, Xiao-Ping; Wang, Yan

    2005-01-01

    changes. CONCLUSION: The porcine ALF model established by two-phase devascularized surgery is valid and reproducible. The hollow fiber BALSS can meet the needs of life support and is effective in treating ALF. PMID:16222738

  19. Evidence of disseminated intravascular coagulation in a porcine model following radiation exposure

    NASA Astrophysics Data System (ADS)

    Krigsfeld, G. S.; Shah, J. B.; Sanzari, J. K.; Lin, L.; Kennedy, A. R.

    2014-10-01

    Recent evidence has suggested that disseminated intravascular coagulation (DIC) plays an integral role in death at the LD50 dose of either gamma or solar particle event (SPE)-like proton radiation in ferrets. In these studies, Yucatan minipigs were evaluated to determine whether they were susceptible to the development of radiation induced DIC. Yucatan minipigs were exposed to a dose of 2.5 Gray (Gy) with X-rays and monitored over the course of 30 days. Evidence of DIC was evaluated by way of thromboelastometry parameters, platelet counts, fibrinogen concentration, and the d-dimer assay. Pigs exposed to X-rays developed signs of DIC within 2 days' post-irradiation. The development of DIC was exacerbated over the course of the studies, and one of the pigs died at day 14 and another had to be euthanized on day 16 post-irradiation. For both of these pigs, DIC was evident at the time of death. The following observations were indicated or were suggestive of DIC: whole blood clotting was impaired (as evidenced by thromboelastometry alterations), there were decreased platelet counts, elevated d-dimer concentrations in the blood, and/or hemorrhaging and the presence of fibrin in tissues observed during post-mortem examination. The extrapolation of data from these studies, in combination with other published data, have led to the hypothesis that there could be a correlation between the propensity to develop DIC, as indicated by hemorrhaging at death at relatively low doses of radiation, and the LD50 for a particular species. Our data suggest that the development of DIC may contribute to death at the LD50 dose in large mammals.

  20. Evidence of Disseminated Intravascular Coagulation in a Porcine Model Following Radiation Exposure

    PubMed Central

    Krigsfeld, G.S.; Shah, J.B.; Sanzari, J.K.; Lin, L.; Kennedy, A.R.

    2014-01-01

    Recent evidence has suggested that disseminated intravascular coagulation (DIC) plays an integral role in death at the LD50 dose of either gamma or solar particle event (SPE)-like proton radiation in ferrets. In these studies, Yucatan minipigs were evaluated to determine whether they were susceptible to the development of radiation induced DIC. Yucatan minipigs were exposed to a dose of 2.5 Gray (Gy) with x-rays and monitored over the course of 30 days. Evidence of DIC was evaluated by way of thromboelastometry parameters, platelet counts, fibrinogen concentration, and the d-dimer assay. Pigs exposed to x-rays developed signs of DIC within 2 days post-irradiation. The development of DIC was exacerbated over the course of the studies, and one of the pigs died at day 14 and another had to be euthanized on day 16 post-irradiation. For both of these pigs, DIC was evident at the time of death. The following observations were indicated or were suggestive of DIC: whole blood clotting was impaired (as evidenced by thromboelastometry alterations), there were decreased platelet counts, elevated d-dimer concentrations in the blood, and/or hemorrhaging and the presence of fibrin in tissues observed during post-mortem examination. The extrapolation of data from these studies, in combination with other published data, have led to the hypothesis that there could be a correlation between the propensity to develop DIC, as indicated by hemorrhaging at death at relatively low doses of radiation, and the LD50 for a particular species. Our data suggest that the development of DIC may contribute to death at the LD50 dose in large mammals. PMID:25197627

  1. Generating a Natural Porcine Model of Gastrointestinal Food Allergy to Peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The peanut (Arachis hypogaea) is an extremely potent allergen and is one of the most life-threatening food sensitivities known. Peanuts cause the majority of food-related anaphylaxis in children, adolescents, and adults. There is no good animal model currently in place to study peanut allergies. Exp...

  2. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1.

    PubMed

    Davis, Catherine C; Baccam, Mekhine; Mantz, Mary J; Osborn, Thomas W; Hill, Donna R; Squier, Christopher A

    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 ((3)H2O) 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)H2O. 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)H2O 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. PMID:24333258

  3. Porcine Sialoadhesin: A Newly Identified Xenogeneic Innate Immune Receptor

    PubMed Central

    Brock, Linda G.; Delputte, Peter L.; Waldman, Joshua P.; Nauwynck, Hans J.; Rees, Michael A.

    2012-01-01

    Extracorporeal porcine liver perfusion is being developed as a bridge to liver allotransplantation for patients with fulminant hepatic failure. This strategy is limited by porcine Kupffer cell destruction of human erythrocytes, mediated by lectin binding of a sialic acid motif in the absence of antibody and complement. Sialoadhesin, a macrophage restricted lectin that binds sialic acid, was originally described as a sheep erythrocyte binding receptor. Given similarities between sialoadhesin and the unidentified macrophage lectin in our model, we hypothesized porcine sialoadhesin contributed to recognition of human erythrocytes. Two additional types of macrophages were identified to bind human erythrocytes - spleen and alveolar. Expression of sialoadhesin was confirmed by immunofluorescence in porcine tissues and by flow cytometry on primary macrophages. A stable transgenic cell line expressing porcine sialoadhesin (pSn CHO) bound human erythrocytes, while a sialoadhesin mutant cell line did not. Porcine macrophage and pSn CHO recognition of human erythrocytes was inhibited approximately 90% by an anti-porcine sialoadhesin monoclonal antibody and by human erythrocyte glycoproteins. Furthermore, this binding was substantially reduced by sialidase treatment of erythrocytes. These data support the hypothesis that porcine sialoadhesin is a xenogeneic receptor that mediates porcine macrophage binding of human erythrocytes in a sialic acid-dependent manner. PMID:22958948

  4. In Vivo Evaluation of Lung Microwave Ablation in a Porcine Tumor Mimic Model

    SciTech Connect

    Planche, Olivier; Teriitehau, Christophe; Boudabous, Sana; Robinson, Joey Marie; Rao, Pramod; Deschamps, Frederic; Farouil, Geoffroy; Baere, Thierry de

    2013-02-15

    To evaluate the microwave ablation of created tumor mimics in the lung of a large animal model (pigs), with examination of the ablative synergy of multiple antennas. Fifty-six tumor-mimic models of various sizes were created in 15 pigs by using barium-enriched minced collected thigh muscle injected into the lung of the same animal. Tumors were ablated under fluoroscopic guidance by single-antenna and multiple-antenna microwaves. Thirty-five tumor models were treated in 11 pigs with a single antenna at 75 W for 15 min, with 15 measuring 20 mm in diameter, 10 measuring 30 mm, and 10 measuring 40 mm. Mean circularity of the single-antenna ablation zones measured 0.64 {+-} 0.12, with a diameter of 35.7 {+-} 8.7 mm along the axis of the antenna and 32.7 {+-} 12.8 mm perpendicular to the feeding point. Multiple-antenna delivery of 75 W for 15 min caused intraprocedural death of 2 animals; modified protocol to 60 W for 10 min resulted in an ablation zone with a diameter of 43.0 {+-} 7.7 along the axis of the antenna and 54.8 {+-} 8.5 mm perpendicular to the feeding point; circularity was 0.70 {+-} 0.10. A single microwave antenna can create ablation zones large enough to cover lung tumor mimic models of {<=}4 cm with no heat sink effect from vessels of {<=}6 mm. Synergic use of 3 antennas allows ablation of larger volumes than single-antenna or radiofrequency ablation, but great caution must be taken when 3 antennas are used simultaneously in the lung in clinical practice.

  5. CT and MRI of experimentally induced mesenteric ischemia in a porcine model

    SciTech Connect

    Klein, H.M.; Seggewib, C.; Weghaus, P.; Kamp, M.; Guenther, R.W.

    1996-03-01

    Our goal was to assess the value of CT and MRI for the detection of bowel wall changes in experimentally induced mesenteric ischemia. In 18 female pigs. a percutaneous embolization of the superior mesenteric artery was performed with buthyl-2-cyanoacrylate and Lipoidal (1:1) (experimental group). In six animals, only diagnostic imaging and histologic evaluation were performed (control group). CT was carried out 3, 6, and 12 h after occlusion. Incremental CT (1 s scan time, 5 mm slice thickness, 7 mm increment, 120 kV/290 mAs) and spiral CT (slice thickness 5 mm, pitch 1.5, 120 kV/165 mA) were performed pre and post contrast injection (Somatom Plus/ Siemens). Serial CT was carried out after intravenous contrast injection (I ml/kg, 2 ml/s). MRI (Magnetom 1.5 T: Siemens) was performed with T1 (pre and post 0.01 mmol/kg Gd-DTPA; Magnevist; Schering. Germany), T2, and proton density images in axial orientation. Slice thickness was 3 mm and slice gap 1 mm. Additionally, a T1-weighted GE sequence was obtained in dynamic technique (before and 30, 60, and 90 s after contrast agent injection) with a slice thickness of 5 mm. Biometrical monitoring included blood pressure, heart frequency, blood cell count, electrolyte status, blood gas analysis, and determination of serum lactate. Image evaluation included morphological analysis and determination of the enhancement pattern. Histological specimens were obtained and analyzed according to the Chiu classification. The histologic workup of the specimen 3, 6, and 12 h after vascular occlusion revealed an average Chiu state 3, 4, and 5. On CT, the bowel wall had a thickness of 4.7 mm on average in the ischemic segments. There was a significant difference from the control group. Free intraperitoneal fluid and intramural gas were seen after 12 h of ischemia in 80%. In ischemic bowel segments, no mural enhancement was seen. Normal segments and the bowel of the control animals showed an enhancement of 34 HU on average.

  6. Monitoring and modeling growing season dynamics

    NASA Astrophysics Data System (ADS)

    White, Michael Aaron

    Phenology, the study of recurring biological cycles and their connection to climate, is a growing field of global change research. Vegetation phenology exerts a strong control over carbon cycles, weather, and global radiation partitioning between sensible and latent heat fluxes. Phenological monitors of the timing and length of the growing season can also be used as barometers of vegetation responses to climatic variability. In the following chapters, I present research investigating the monitoring and interpretation of growing season dynamics. Ecological modeling is limited more by data availability than by model theory. In particular, the description of vegetation functional types (biomes) for distributed modeling has been lacking. In chapter 1, I present a documented description and sensitivity analysis of the 34 parameters used in the ecosystem model, BIOME-BGC, for major temperate biomes. I applied BIOME-BGC in the eastern U.S. deciduous broad leaf forest and found that minor phenological variation created large impacts on simulated net ecosystem exchange of carbon (chapter 2). In addition to simulating the effects of growing season variability, it is also important to develop accurate field monitoring techniques, both as a means of testing modeling activities and as a validation of satellite remote sensing estimates. I conducted an intercomparison of field techniques that could be used to monitor phenological dynamics in and ecosystems (chapter 3). I found that methodological barriers to rapid, low cost monitoring were severe, but that a digital camera with both visible and near-infrared channels was a viable option. Satellite remote sensing provides the only means of obtaining consistent estimates of phenological variation at a global scale, yet our understanding of these data has been limited by a lack of ground observations. To address this problem, I proposed, developed, and wrote a phenology measurement protocol for the Global Learning and Observations

  7. Establishment of a novel, eco-friendly transgenic pig model using porcine pancreatic amylase promoter-driven fungal cellulase transgenes.

    PubMed

    Lin, Y S; Yang, C C; Hsu, C C; Hsu, J T; Wu, S C; Lin, C J; Cheng, W T K

    2015-02-01

    Competition between humans and livestock for cereal and legume grains makes it challenging to provide economical feeds to livestock animals. Recent increases in corn and soybean prices have had a significant impact on the cost of feed for pig producers. The utilization of byproducts and alternative ingredients in pig diets has the potential to reduce feed costs. Moreover, unlike ruminants, pigs have limited ability to utilize diets with high fiber content because they lack endogenous enzymes capable of breaking down nonstarch polysaccharides into simple sugars. Here, we investigated the feasibility of a transgenic strategy in which expression of the fungal cellulase transgene was driven by the porcine pancreatic amylase promoter in pigs. A 2,488 bp 5'-flanking region of the porcine pancreatic amylase gene was cloned by the genomic walking technique, and its structural features were characterized. Using GFP as a reporter, we found that this region contained promoter activity and had the potential to control heterologous gene expression. Transgenic pigs were generated by pronuclear microinjection. Founders and offspring were identified by PCR and Southern blot analyses. Cellulase mRNA and protein showed tissue-specific expression in the pancreas of F1 generation pigs. Cellulolytic enzyme activity was also identified in the pancreas of transgenic pigs. These results demonstrated the establishment of a tissue-specific promoter of the porcine pancreatic amylase gene. Transgenic pigs expressing exogenous cellulase may represent a way to increase the intake of low-cost, fiber-rich feeds. PMID:25063310

  8. Amniotic Fluid-Derived Mesenchymal Stem Cells Prevent Fibrosis and Preserve Renal Function in a Preclinical Porcine Model of Kidney Transplantation

    PubMed Central

    Baulier, Edouard; Favreau, Frederic; Le Corf, Amélie; Jayle, Christophe; Schneider, Fabrice; Goujon, Jean-Michel; Feraud, Olivier; Bennaceur-Griscelli, Annelise; Turhan, Ali G.

    2014-01-01

    It is well known that ischemia/reperfusion injuries strongly affect the success of human organ transplantation. Development of interstitial fibrosis and tubular atrophy is the main deleterious phenomenon involved. Stem cells are a promising therapeutic tool already validated in various ischemic diseases. Amniotic fluid-derived mesenchymal stem cells (af-MSCs), a subpopulation of multipotent cells identified in amniotic fluid, are known to secrete growth factors and anti-inflammatory cytokines. In addition, these cells are easy to collect, present higher proliferation and self-renewal rates compared with other adult stem cells (ASCs), and are suitable for banking. Consequently, af-MSCs represent a promising source of stem cells for regenerative therapies in humans. To determine the efficiency and the safety of af-MSC infusion in a preclinical porcine model of renal autotransplantation, we injected autologous af-MSCs in the renal artery 6 days after transplantation. The af-MSC injection improved glomerular and tubular functions, leading to full renal function recovery and abrogated fibrosis development at 3 months. The strong proof of concept generated by this translational porcine model is a first step toward evaluation of af-MSC-based therapies in human kidney transplantation. PMID:24797827

  9. Primary in vitro culture of porcine tracheal epithelial cells in an air-liquid interface as a model to study airway epithelium and Aspergillus fumigatus interactions.

    PubMed

    Khoufache, Khaled; Cabaret, Odile; Farrugia, Cécile; Rivollet, Danièle; Alliot, Annie; Allaire, Eric; Cordonnier, Catherine; Bretagne, Stéphane; Botterel, Françoise

    2010-12-01

    Since the airway epithelium is the first tissue encountered by airborne fungal spores, specific models are needed to study this interaction. We developed such a model using primary porcine tracheal epithelial cells (PTEC) as a possible alternative to the use of primary human cells. PTEC were obtained from pigs and were cultivated in an air-liquid interface. Fluorescent brightener was employed to quantify the internalization of Aspergillus fumigatus conidia. Potential differences (Vt) and transepithelial resistances (Rt) after challenge with the mycotoxin, verruculogen, were studied. Primers for porcine inflammatory mediator genes IL-8, TNF-alpha, and GM-CSF were designed for a quantitative real-time PCR procedure to study cellular responses to challenges with A. fumigatus conidia. TEM showed the differentiation of ciliated cells and the PTEC ability to internalize conidia. The internalization rate was 21.9 ± 1.4% after 8 h of incubation. Verruculogen (10(-6) M) significantly increased Vt without having an effect on the Rt. Exposure of PTEC to live A. fumigatus conidia for 24 h induced a 10- to 40-fold increase in the mRNA levels of inflammatory mediator genes. PTEC behave similarly to human cells and are therefore a suitable alternative to human cells for studying interaction between airway epithelium and A. fumigatus. PMID:20608777

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

    PubMed Central

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

    2015-01-01

    Background A 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. Methods 10 pigs (group A) underwent infrarenal aortic dissection, balloon dilatation, infusion of elastase into the lumen and placement of a stenosing cuff around the aorta. 10 control pigs (group B) underwent a sham procedure. The subsequent 28 days the AP-diameters of the aneurysms were measured using ultrasound, hereafter the pigs were euthanized for inspection and AAA wall sampling for histological analysis. Results In 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 equivalent to 9.3% which was significantly less than in group A (p < 0.001). In group A, a significant negative association between the preoperative weight and the resulting AP-diameters was found. Histology shoved more or less complete resolution of the elastic tissue in the tunica media in group A. The most frequent complication was a neurological deficit in the lower limbs. Conclusion In 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 model for further studies of novel endovascular devices and their complications. PMID:25685342

  11. Scaffold-Based Delivery of Autologous Mesenchymal Stem Cells for Mandibular Distraction Osteogenesis: Preliminary Studies in a Porcine Model

    PubMed Central

    Sun, Zongyang; Tee, Boon Ching; Kennedy, Kelly S.; Kennedy, Patrick M.; Kim, Do-Gyoon; Mallery, Susan R.; Fields, Henry W.

    2013-01-01

    Purpose Bone regeneration through distraction osteogenesis (DO) is promising but remarkably slow. To accelerate it, autologous mesenchymal stem cells have been directly injected to the distraction site in a few recent studies. Compared to direct injection, a scaffold-based method can provide earlier cell delivery with potentially better controlled cell distribution and retention. This pilot project investigated a scaffold-based cell-delivery approach in a porcine mandibular DO model. Materials and Methods Eleven adolescent domestic pigs were used for two major sets of studies. The in-vitro set established methodologies to: aspirate bone marrow from the tibia; isolate, characterize and expand bone marrow-derived mesenchymal stem cells (BM-MSCs); enhance BM-MSC osteogenic differentiation using FGF-2; and confirm cell integration with a gelatin-based Gelfoam scaffold. The in-vivo set transplanted autologous stem cells into the mandibular distraction sites using Gelfoam scaffolds; completed a standard DO-course and assessed bone regeneration by macroscopic, radiographic and histological methods. Repeated-measure ANOVAs and t-tests were used for statistical analyses. Results From aspirated bone marrow, multi-potent, heterogeneous BM-MSCs purified from hematopoietic stem cell contamination were obtained. FGF-2 significantly enhanced pig BM-MSC osteogenic differentiation and proliferation, with 5 ng/ml determined as the optimal dosage. Pig BM-MSCs integrated readily with Gelfoam and maintained viability and proliferative ability. After integration with Gelfoam scaffolds, 2.4–5.8×107 autologous BM-MSCs (undifferentiated or differentiated) were transplanted to each experimental DO site. Among 8 evaluable DO sites included in the final analyses, the experimental DO sites demonstrated less interfragmentary mobility, more advanced gap obliteration, higher mineral content and faster mineral apposition than the control sites, and all transplanted scaffolds were completely

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

    NASA Astrophysics Data System (ADS)

    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

  13. Low-Intensity Pulsed Ultrasound Induces Angiogenesis and Ameliorates Left Ventricular Dysfunction in a Porcine Model of Chronic Myocardial Ischemia

    PubMed Central

    Hanawa, Kenichiro; Ito, Kenta; Aizawa, Kentaro; Shindo, Tomohiko; Nishimiya, Kensuke; Hasebe, Yuhi; Tuburaya, Ryuji; Hasegawa, Hideyuki; Yasuda, Satoshi; Kanai, Hiroshi; Shimokawa, Hiroaki

    2014-01-01

    Background 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. Methods and Results 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. Conclusions These results suggest that the LIPUS therapy is promising as a new, non-invasive therapy for IHD. PMID:25111309

  14. Effects of renal pelvic high-pressure perfusion on nephrons in a porcine pyonephrosis model.

    PubMed

    Wang, Jian; Zhou, DA-Qing; He, Meng; Li, Wen-Gang; Pang, Xiang; Yu, Xiao-Xiang; Jiang, Bo

    2013-05-01

    The aim of this study was to investigate the effects of various renal pelvic pressure gradients on nephrons with purulent infection. Five miniature test pigs were selected. One side of the kidney was used to prepare the pyonephrosis model and the other side was used as the healthy control. A piezometer and a water fill tube were inserted into the renal pelvis through the ureter. Prior to perfusion, punctures were made on the healthy and purulent sides of the kidneys to obtain tissues (as controls). Subsequently, a puncture biopsy was conducted on the kidneys at five pressure levels: 10, 20, 30, 40 and 50 mmHg. Once the renal pelvic pressure had increased, the healthy and injured kidneys presented pathological changes, including dilation of the renal tubule and capsule and compression of the renal glomerulus. When the renal pelvic pressure exceeded 20 mmHg, the injured kidney presented more damage. Electron microscopy revealed that the increase in pressure resulted in the following: the podocyte gap widened, the epithelial cells of the renal capsule separated from the basement membrane, the basement membrane thickness became uneven, the continuity of the basement membrane was interrupted at multiple positions and the renal tubule microvillus arrangement became disorganised. The manifestations in the pyonephrosis model were more distinct compared with those in the healthy kidney. As the renal pelvic pressure exceeds 20 mmHg under a renal purulent infection status, the nephrons become damaged. The extent of the damage is aggravated as the pressure is increased. PMID:23737886

  15. Effects of renal pelvic high-pressure perfusion on nephrons in a porcine pyonephrosis model

    PubMed Central

    WANG, JIAN; ZHOU, DA-QING; HE, MENG; LI, WEN-GANG; PANG, XIANG; YU, XIAO-XIANG; JIANG, BO

    2013-01-01

    The aim of this study was to investigate the effects of various renal pelvic pressure gradients on nephrons with purulent infection. Five miniature test pigs were selected. One side of the kidney was used to prepare the pyonephrosis model and the other side was used as the healthy control. A piezometer and a water fill tube were inserted into the renal pelvis through the ureter. Prior to perfusion, punctures were made on the healthy and purulent sides of the kidneys to obtain tissues (as controls). Subsequently, a puncture biopsy was conducted on the kidneys at five pressure levels: 10, 20, 30, 40 and 50 mmHg. Once the renal pelvic pressure had increased, the healthy and injured kidneys presented pathological changes, including dilation of the renal tubule and capsule and compression of the renal glomerulus. When the renal pelvic pressure exceeded 20 mmHg, the injured kidney presented more damage. Electron microscopy revealed that the increase in pressure resulted in the following: the podocyte gap widened, the epithelial cells of the renal capsule separated from the basement membrane, the basement membrane thickness became uneven, the continuity of the basement membrane was interrupted at multiple positions and the renal tubule microvillus arrangement became disorganised. The manifestations in the pyonephrosis model were more distinct compared with those in the healthy kidney. As the renal pelvic pressure exceeds 20 mmHg under a renal purulent infection status, the nephrons become damaged. The extent of the damage is aggravated as the pressure is increased. PMID:23737886

  16. Edmund Prince Fowler Award Thesis. Evaluation of random skin flap survival in a porcine model.

    PubMed

    Pratt, M F

    1996-06-01

    The pathophysiology of random skin flap necrosis in the pig model was studied the effects of several drugs on skin flap survival were examined. The investigated drugs included acetylsalicylic acid (ASA), pentoxifylline (PTX), prostaglandin E2 (PGE2), and an experimental 21-aminosteroid, U-74389G. Each drug altered different parameters known to be associated with tissue necrosis. Demonstrated mechanisms of skin flap failure included the alteration of erythrocyte flexibility and platelet function and the activation of neutrophils with resultant accumulation of damaging oxygen-free radicals. Random skin flap survival did not improve with ASA but did improve significantly with PTX, PGE2, and U-74389G. The results of this study underscore the importance of neutrophil-mediated necrosis in the pathophysiology of skin flap failure. The data further demonstrate the need to develop drugs aimed at reversing or preventing the tissue damage from oxygen-free radicals in order to enhance the survival of random skin flaps. PMID:8656954

  17. The impact of force on the timing of bruises evaluated in a porcine model.

    PubMed

    Barington, Kristiane; Jensen, Henrik Elvang

    2016-05-01

    In animal models developed in order to estimate the age of bruises, focus has been on the changes over time and not considering the force used to inflict the trauma. In the present study, gross and histological changes in 2, 4, 6 and 8 h old bruises which were inflicted with a low, moderate and high force were compared. Twelve experimental pigs were randomly assigned to three groups of force (low, moderate and high force). All pigs were anesthetized, and on each animal four blunt traumas were inflicted on the back with the low, moderate or high force according to the groups. The pigs were kept in anesthesia for 2, 4, 6 or 8 h, after which they were euthanized, and skin and muscle tissues were sampled for histology. As control, two pigs were included. The gross appearance of bruises developed similarly until 0.5 h after infliction at which time the visibility of the bruises depended on the force. The infiltration of subcutaneous neutrophils depended on the time and force used which was confirmed by both manual evaluation and image analysis of immunostained skin sections. In the muscle tissue, the number of macrophages was found useful for age determination in bruises inflicted with the highest force. Therefore, when evaluating forensic cases of bruises in both human and veterinary pathology the impact of force and not only the timing should be taken into consideration. PMID:27085141

  18. A model aerosol exposure system for induction of porcine Haemophilus pleuropneumonia.

    PubMed Central

    Sebunya, T N; Saunders, J R; Osborne, A D

    1983-01-01

    One group of six pigs and another group of three pigs were separately exposed in a polyethylene enclosed chamber for ten minutes, respectively, to Haemophilus pleuropneumoniae serotype 1 and Bacillus subtilis aerosols generated by an ultrasonic nebulizer. Haemophilus pleuropneumoniae and B. subtilis were deposited throughout the lungs immediately following aerosol exposure. The number of H. pleuropneumoniae and B. subtilis deposited varied within and between lungs in each group. The mean numbers of both organisms deposited in the posterior (caudal and accessory) lobes were significantly greater than those in the anterior (cranial and middle) lobes (P less than 0.001). The four principals that received H. pleuropneumoniae aerosols and the two contact controls developed fatal fibrinous pneumonia which simulated that seen in natural infections. Since this exposure system consistently resulted in clinical disease it has good potential as a model for the study of pathogenesis of the disease and more specifically for the evaluation of vaccines. Images Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. PMID:6403208

  19. Acute Hematological Effects of Solar Particle Event Proton Radiation in the Porcine Model

    PubMed Central

    Sanzari, J. K.; Wan, X. S.; Wroe, A. J.; Rightnar, S.; Cengel, K. A.; Diffenderfer, E. S.; Krigsfeld, G. S.; Gridley, D. S.; Kennedy, A. R.

    2013-01-01

    Acute radiation sickness (ARS) is expected to occur in astronauts during large solar particle events (SPEs). One parameter associated with ARS is the hematopoietic syndrome, which can result from decreased numbers of circulating blood cells in those exposed to radiation. The peripheral blood cells are critical for an adequate immune response, and low blood cell counts can result in an increased susceptibility to infection. In this study, Yucatan minipigs were exposed to proton radiation within a range of skin dose levels expected for an SPE (estimated from previous SPEs). The proton-radiation exposure resulted in significant decreases in total white blood cell count (WBC) within 1 day of exposure, 60% below baseline control value or preirradiation values. At the lowest level of the blood cell counts, lymphocytes, neutrophils, monocytes and eosinophils were decreased up to 89.5%, 60.4%, 73.2% and 75.5%, respectively, from the preirradiation values. Monocytes and lymphocytes were decreased by an average of 70% (compared to preirradiation values) as early as 4 h after radiation exposure. Skin doses greater than 5 Gy resulted in decreased blood cell counts up to 90 days after exposure. The results reported here are similar to studies of ARS using the nonhuman primate model, supporting the use of the Yucatan minipig as an alternative. In addition, the high prevalence of hematologic abnormalities resulting from exposure to acute, whole-body SPE-like proton radiation warrants the development of appropriate countermeasures to prevent or treat ARS occurring in astronauts during space travel. PMID:23672458

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:27310573

  2. Acute hematological effects of solar particle event proton radiation in the porcine model.

    PubMed

    Sanzari, J K; Wan, X S; Wroe, A J; Rightnar, S; Cengel, K A; Diffenderfer, E S; Krigsfeld, G S; Gridley, D S; Kennedy, A R

    2013-07-01

    Acute radiation sickness (ARS) is expected to occur in astronauts during large solar particle events (SPEs). One parameter associated with ARS is the hematopoietic syndrome, which can result from decreased numbers of circulating blood cells in those exposed to radiation. The peripheral blood cells are critical for an adequate immune response, and low blood cell counts can result in an increased susceptibility to infection. In this study, Yucatan minipigs were exposed to proton radiation within a range of skin dose levels expected for an SPE (estimated from previous SPEs). The proton-radiation exposure resulted in significant decreases in total white blood cell count (WBC) within 1 day of exposure, 60% below baseline control value or preirradiation values. At the lowest level of the blood cell counts, lymphocytes, neutrophils, monocytes and eosinophils were decreased up to 89.5%, 60.4%, 73.2% and 75.5%, respectively, from the preirradiation values. Monocytes and lymphocytes were decreased by an average of 70% (compared to preirradiation values) as early as 4 h after radiation exposure. Skin doses greater than 5 Gy resulted in decreased blood cell counts up to 90 days after exposure. The results reported here are similar to studies of ARS using the nonhuman primate model, supporting the use of the Yucatan minipig as an alternative. In addition, the high prevalence of hematologic abnormalities resulting from exposure to acute, whole-body SPE-like proton radiation warrants the development of appropriate countermeasures to prevent or treat ARS occurring in astronauts during space travel. PMID:23672458

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

    PubMed Central

    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

    2015-01-01

    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. PMID:25713753

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

    PubMed

    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. PMID:26256624

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

    PubMed Central

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

    2015-01-01

    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 dermis 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. PMID:26256624

  6. Evaluation of a Novel Laser-assisted Coronary Anastomotic Connector - the Trinity Clip - in a Porcine Off-pump Bypass Model

    PubMed Central

    Stecher, David; Bronkers, Glenn; Noest, Jappe O.T.; Tulleken, Cornelis A.F.; Hoefer, Imo E.; van Herwerden, Lex A.; Pasterkamp, Gerard; Buijsrogge, Marc P.

    2014-01-01

    To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated. PMID:25490000

  7. Interactive real-time mapping and catheter ablation of the cavotricuspid isthmus guided by magnetic resonance imaging in a porcine model

    PubMed Central

    Hoffmann, Boris A.; Koops, Andreas; Rostock, Thomas; Müllerleile, Kai; Steven, Daniel; Karst, Roman; Steinke, Mark U.; Drewitz, Imke; Lund, Gunnar; Koops, Susan; Adam, Gerhard; Willems, Stephan

    2010-01-01

    Aims We investigated the feasibility of real-time magnetic resonance imaging (RTMRI) guided ablation of the cavotricuspid isthmus (CTI) by using a MRI-compatible ablation catheter. Methods and results Cavotricuspid isthmus ablation was performed in an interventional RTMRI suite by using a novel 7 French, steerable, non-ferromagnetic ablation catheter in a porcine in vivo model (n = 20). The catheter was introduced and navigated by RTMRI visualization only. Catheter position and movement during manipulation were continuously visualized during the entire intervention. Two porcine prematurely died due to VT/VF. Anatomical completion of the CTI ablation line could be achieved after a mean of 6.3±3 RF pulses (RF energy: 1807±1016.4 Ws/RF pulse, temperature: 55.9±5.9°C) in n = 18 animals. In 15 of 18 procedures (83.3%) a complete CTI block was proven by conventional mapping in the electrophysiological (EP) lab. Conclusion Completely non-fluoroscopic ablation guided by RTMRI using a steerable and non-ferromagnetic catheter is a promising novel technology in interventional electrophysiology. PMID:19897495

  8. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system.

    PubMed

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

    2016-03-21

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR  <  0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR [Formula: see text] 0.65, the anterior-to-lateral flow ratio was 0.29  ±  0.01, over-estimating stenosis severity as compared to 0.42  ±  0.01 (p  <  0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50  ±  0.04 falsely indicating an actionable ischemic condition

  9. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR  <  0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29  ±  0.01, over-estimating stenosis severity as compared to 0.42  ±  0.01 (p  <  0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50  ±  0.04 falsely indicating an actionable ischemic condition in a healthy

  10. Georeferenced model simulations efficiently support targeted monitoring

    NASA Astrophysics Data System (ADS)

    Berlekamp, Jürgen; Klasmeier, Jörg

    2010-05-01

    The European Water Framework Directive (WFD) demands the good ecological and chemical status of surface waters. To meet the definition of good chemical status of the WFD surface water concentrations of priority pollutants must not exceed established environmental quality standards (EQS). Surveillance of the concentrations of numerous chemical pollutants in whole river basins by monitoring is laborious and time-consuming. Moreover, measured data do often not allow for immediate source apportionment which is a prerequisite for defining promising reduction strategies to be implemented within the programme of measures. In this context, spatially explicit model approaches are highly advantageous because they provide a direct link between local point emissions (e.g. treated wastewater) or diffuse non-point emissions (e.g. agricultural runoff) and resulting surface water concentrations. Scenario analyses with such models allow for a priori investigation of potential positive effects of reduction measures such as optimization of wastewater treatment. The geo-referenced model GREAT-ER (Geography-referenced Regional Exposure Assessment Tool for European Rivers) has been designed to calculate spatially resolved averaged concentrations for different flow conditions (e.g. mean or low flow) based on emission estimations for local point source emissions such as treated effluents from wastewater treatment plants. The methodology was applied to selected pharmaceuticals (diclofenac, sotalol, metoprolol, carbamazepin) in the Main river basin in Germany (approx. 27,290 km²). Average concentrations of the compounds were calculated for each river reach in the whole catchment. Simulation results were evaluated by comparison with available data from orienting monitoring and used to develop an optimal monitoring strategy for the assessment of water quality regarding micropollutants at the catchment scale.

  11. Endoscopic knot tying: In vitro assessment in a porcine stomach model

    PubMed Central

    Ciocirlan, Mihai; Ionescu, Mirela Elena; Diculescu, Mircea Mihai

    2013-01-01

    AIM: To determine if surgical knotting performed via endoscopy is an effective closure method for natural orifice translumenal endoscopic surgery. METHODS: The proposed method was tested on an in vitro pig stomach model using standard endoscopy suite materials. A single use laparoscopy trocar (Versaport Plus manufactured by Tyco Healthcare) was fixed onto a plastic rectangular box in a horizontal position. A fresh pig stomach was tightly attached via its esophageal end to the trocar opening on the inner side of the box. The stomach cavity was closed at the duodenal end with Kocher forceps. A standard upper gastrointestinal endoscope fitted at its tip with a transparent plastic cap was introduced into the stomach through the outer trocar opening, so that the passage of the surgical trocar would mimic the passage of an esophagus. The stomach was subsequently inflated, followed by irrigation and washing. A neutral electrode of an electrocautery unit was placed inside the plastic box, underneath the pig stomach. The stomach’s outer surface was kept moist using normal saline in order to maintain the natural elasticity and to ensure good contact with the electrode. RESULTS: The submucosal space on the anterior face of the stomach was accessed using the technique of endoscopic submucosal dissection. First, a site on the anterior face of the stomach was chosen, near the angle. Then, saline was injected into the submucosa with a standard endoscopic needle, so as to create a 20 mm diameter elevation. A linear 15 mm vertical incision was created at its center using a Dual Knife (KD650U manufactured by Olympus). This incision was used to access the submucosal space, and about 10 mm was dissected on both sides of the incision. The endoscope was then pushed through to the outside of the stomach after dilating a small puncture made by the Dual Knife in the muscularis propria, which simulated the peritoneoscopy procedure. Then, a 0.025” guidewire (Jagwire/450 cm manufactured

  12. Numerical modeling of explosions for nuclear monitoring

    NASA Astrophysics Data System (ADS)

    Stevens, J. L.

    2014-12-01

    Monitoring the Earth for underground nuclear explosions requires a detailed understanding of the explosion source. In this context, "source" refers to the source of seismic waves, and it is generated by the complex nonlinear near-source motion that accompanies the nuclear explosion. In particular, nuclear monitoring requires understanding the transition from the hydrodynamic to elastic regimes, and propagation of waveforms from the source to stations at distances of hundreds to thousands of kilometers. In the transition region, shear strength is critically important, as are changes in shear strength as the shock wave propagates. Numerical modeling using 1D spherically symmetric, 2D axisymmetric and full 3D calculations provides important insights into the seismic source and the waveforms it generates. Important considerations for numerical modeling include emplacement conditions (tamped or in a cavity), source type (chemical or nuclear), material models for strength and strength reduction, and geologic conditions including topography and tectonic stresses in the source region. In addition to calculating the near source ground motion, we propagate the near source solution to regional and teleseismic distances where the observations of seismic signals from nuclear explosions are made. The objectives of nuclear monitoring are detection of seismic events (earthquakes, quarry blasts and other sources in addition to nuclear explosions), accurate location of these events, discrimination of nuclear explosions from other types of sources, and estimation of nuclear explosion yield. Numerical modeling is particularly important for discrimination and yield estimation. Numerical modeling is used to understand unexpected anomalies that occur, such as the large surface waves generated by the three North Korean nuclear tests, which may have been caused by a difference in tectonic stress state between North Korea and other test sites. Another important issue that can be addressed

  13. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

    SciTech Connect

    Davis, Catherine C.; Baccam, Mekhine; Mantz, Mary J.; Osborn, Thomas W.; Hill, Donna R.; Squier, Christopher A.

    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.

  14. The Porcine Immunology and Nutrition Resource Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diverse genomics-based databases have been developed to facilitate research with human and rodent models. Current porcine gene databases, however, lack the nutritional and immunological orientation and robust annotation to design effective molecular tools to study relevant pig models. To address t...

  15. Effect of Splenic Regulatory T-cell Apoptosis on the Postresuscitation Immune Dysfunction in a Porcine Model

    PubMed Central

    Gu, Wei; Zhang, Qian; Li, Chun-Sheng

    2016-01-01

    Background: Postresuscitation immune dysfunction contributes to the low survival rate after successful resuscitation, but its mechanism remains poorly understood. The purpose of this study was to investigate whether splenic regulatory T-cell (Treg) apoptosis was involved in the postresuscitation immune dysfunction. Methods: Thirty-eight pigs were randomly divided into sham-operated group (SHAM group, n = 8), 12 h post return of spontaneous circulation (ROSC) group, 24 h post-ROSC group, and 48 h post-ROSC group (n = 10 per group). A Wuzhishan miniature porcine model of 8-min ventricular fibrillation cardiac arrest (CA) was established. The apoptosis rates of Treg in the spleen were tested by flow cytometry; the expressions of forkhead/winged helix transcription factor (Foxp3) of Treg in the spleen were detected by real-time polymerase chain reaction; and the levels of interleukin-4 (IL-4), IL-10, and interferon gamma (IFN-γ) of Treg in the spleen were detected by enzyme-linked immunosorbent assay. Results: The apoptosis rates of Treg in all post-ROSC groups were significantly lower than that of SHAM group (7.7% ± 1.9%, 7.1% ± 1.8%, 6.2% ± 0.4% vs. 13.1% ± 1.6%; P < 0.05); the expression levels of Foxp3 and IL-10 were also decreased with the increase of apoptosis rates of Treg. Helper T-cells CD4+ lymphocyte subsets were significantly lower in the post-ROSC groups compared with SHAM group (29.1% ± 2.2%, 24.3% ± 2.2%, 24.1% ± 2.5% vs. 43.8% ± 4.5%; P < 0.01) at 12, 24, and 48 h after ROSC. Compared with SHAM group, the levels of IFN-γ (161.0 ± 12.9, 167.7 ± 10.5, 191.2 ± 7.7 vs. 7.6 ± 0.9 ng/L) and IL-4 (27.7 ± 6.2, 35.9 ± 3.5, 50.6 ± 6.1 vs. 13.3 ± 2.3 ng/L) and the ratio of IFN-γ/IL-4 (8.6 ± 2.3, 4.9 ± 0.4, 4.5 ± 0.9 vs. 0.8 ± 0.2) were all greatly elevated in all post-ROSC groups (P < 0.05). Conclusions: Apoptosis rate of Treg was significantly decreased after CA, and thus the proportion of Treg was increased and the inhibitory effects were

  16. Lentiviral vector gene transfer to porcine airways.

    PubMed

    Sinn, Patrick L; Cooney, Ashley L; Oakland, Mayumi; Dylla, Douglas E; Wallen, Tanner J; Pezzulo, Alejandro A; Chang, Eugene H; McCray, Paul B

    2012-01-01

    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).Molecular Therapy - Nucleic Acids (2012) 1, e56; doi:10.1038/mtna.2012.47; published online 27 November 2012. PMID:23187455

  17. The Effects of Negative Pressure by External Tissue Expansion Device on Epithelial Cell Proliferation, Neo-Vascularization and Hair Growth in a Porcine Model

    PubMed Central

    Hsiao, Hui-Yi; Liu, Jia-Wei; Brey, Eric M.; Cheng, Ming-Huei

    2016-01-01

    While pre-treating a fat transplant recipient site with negative pressure has shown promise for increasing the fat survival rate, the underlying mechanisms have not been investigated, partly due to challenges related to immobilization of vacuum domes on large animal subjects. The aim of this study was to examine the effect of negative pressure treatment by External Tissue Expansion Device (ETED) on fat grating recipient sites in a porcine model. The ETED was designed to provide negative pressure on the dorsum of swine. Pressure treatment (-70 mmHg) was applied for 1 or 3 hours every other day for 10 and 20 treatments. The treated areas (3.5 cm in diameter) were harvested and examined for histological changes, vessel density, cell proliferation (Ki67) and growth factor expression (FGF-1, VEGF and PDGB-bb). The application of the ETED increased epidermis thickness even after 1-hour treatments repeated 10 times. The results of Ki67 analysis suggested that the increasing thickness was due to cell proliferation in the epidermis. There was a more than two-fold increase in the vessel density, indicating that the ETED promotes vascularization. Unexpectedly, the treatment also increased the number of hair follicles. Negative pressure provided by the ETED increases the thickness of epidermis section of tissue, cell proliferation and vessel density. The porcine model provides a better representation of the effect of the ETED on skin tissue compared to small animal models and provides an environment for studying the mechanisms underlying the clinical benefits of negative pressure treatment. PMID:27128731

  18. The Effects of Negative Pressure by External Tissue Expansion Device on Epithelial Cell Proliferation, Neo-Vascularization and Hair Growth in a Porcine Model.

    PubMed

    Hsiao, Hui-Yi; Liu, Jia-Wei; Brey, Eric M; Cheng, Ming-Huei

    2016-01-01

    While pre-treating a fat transplant recipient site with negative pressure has shown promise for increasing the fat survival rate, the underlying mechanisms have not been investigated, partly due to challenges related to immobilization of vacuum domes on large animal subjects. The aim of this study was to examine the effect of negative pressure treatment by External Tissue Expansion Device (ETED) on fat grating recipient sites in a porcine model. The ETED was designed to provide negative pressure on the dorsum of swine. Pressure treatment (-70 mmHg) was applied for 1 or 3 hours every other day for 10 and 20 treatments. The treated areas (3.5 cm in diameter) were harvested and examined for histological changes, vessel density, cell proliferation (Ki67) and growth factor expression (FGF-1, VEGF and PDGB-bb). The application of the ETED increased epidermis thickness even after 1-hour treatments repeated 10 times. The results of Ki67 analysis suggested that the increasing thickness was due to cell proliferation in the epidermis. There was a more than two-fold increase in the vessel density, indicating that the ETED promotes vascularization. Unexpectedly, the treatment also increased the number of hair follicles. Negative pressure provided by the ETED increases the thickness of epidermis section of tissue, cell proliferation and vessel density. The porcine model provides a better representation of the effect of the ETED on skin tissue compared to small animal models and provides an environment for studying the mechanisms underlying the clinical benefits of negative pressure treatment. PMID:27128731

  19. GLAST Burst Monitor Instrument Simulation and Modeling

    SciTech Connect

    Hoover, A. S.; Kippen, R. M.; Wallace, M. S.; Pendleton, G. N.; Fishman, G. J.; Meegan, C. A.; Kouveliotou, C.; Wilson-Hodge, C. A.; Bhat, P. N.; Briggs, M. S.; Connaughton, V.; Paciesas, W. S.; Preece, R. D.

    2008-05-22

    The GLAST Burst Monitor (GBM) is designed to provide wide field of view observations of gamma-ray bursts and other fast transient sources in the energy range 10 keV to 30 MeV. The GBM is composed of several unshielded and uncollimated scintillation detectors (twelve NaI and two BGO) that are widely dispersed about the GLAST spacecraft. As a result, reconstructing source locations, energy spectra, and temporal properties from GBM data requires detailed knowledge of the detectors' response to both direct radiation as well as that scattered from the spacecraft and Earth's atmosphere. This full GBM instrument response will be captured in the form of a response function database that is derived from computer modeling and simulation. The simulation system is based on the GEANT4 Monte Carlo radiation transport simulation toolset.

  20. Revelation of the IFNα, IL-10, IL-8 and IL-1β as promising biomarkers reflecting immuno-pathological mechanisms in porcine Huntington's disease model.

    PubMed

    Valekova, Ivona; Jarkovska, Karla; Kotrcova, Eva; Bucci, John; Ellederova, Zdenka; Juhas, Stefan; Motlik, Jan; Gadher, Suresh Jivan; Kovarova, Hana

    2016-04-15

    Studies on Huntington's disease (HD) demonstrated altered immune response in HD gene carriers. Using multiplexing immunoassay, we simultaneously investigated seven cytokines in secretomes of microglia and blood monocytes, cerebrospinal fluid (CSF) and serum collected from transgenic HD minipigs at pre-symptomatic disease stage. Decline in IFNα and IL-10 was observed in CSF and secretome of microglia whilst elevated IL-8 and IL-1β levels were secreted by microglia. Additionally, IL-8 was increased in serum. The proportion of mutant huntingtin in microglia may have causative impact on cytokine production. IFNα, IL-10, IL-8 and IL-1β represent promising biomarkers reflecting immuno-pathological mechanisms in porcine HD model. PMID:27049565

  1. Effect of Pretreatment of Ezetimibe/Simvastatin on Arterial Healing and Endothelialization after Drug-Eluting Stent Implantation in a Porcine Coronary Restenosis Model

    PubMed Central

    Sim, Doo Sun; Park, Dae Sung; Kim, Jung Ha; Lim, Kyung Seob; Kim, Hyun Kuk; Kim, Sung Soo; Cho, Jae Yeong; Jeong, Hae Chang; Park, Keun Ho; Hong, Young Joon; Kim, Ju Han; Ahn, Youngkeun; Cho, Jeong Gwan; Park, Jong Chun

    2015-01-01

    Background and Objectives We sought to evaluate the effect of the early use of ezetimibe/simvastatin (Vytorin®) on arterial healing and endothelialization after the implantation of a drug-eluting stent (DES) in a porcine model of coronary restenosis. Materials and Methods A total of 20 pigs (40 coronary arteries) were randomly allocated to a pretreatment or no treatment group. The pretreatment group (n=20) received oral ezetimibe/simvastatin (10/20 mg) daily for 7 days before stenting and the no pretreatment group (n=20) did not. All pigs were treated with ezetimibe/simvastatin (10/20 mg) daily after stenting for 4 weeks. Stenting was performed using a bare-metal stent (BMS, n=10) and three types of DES: biolimus A9-eluting stent (BES, n=10), zotarolimus-eluting stent (ZES, n=10), and everolimus-eluting stents (EES, n=10). Four weeks later, pigs underwent a follow-up coronary angiography and were sacrificed for histopathologic analysis. Results There were no significant differences between the pretreatment and no pretreatment groups in the internal elastic lamina area, lumen area, neointima area, stenotic area, injury score, fibrin score, and inflammation score. In both groups, the fibrin score was higher in pigs with DES than in BMS, particularly in ZES and EES. The inflammatory score was not different between DES and BMS. Conclusion In a porcine model of coronary restenosis, pretreatment with ezetimibe/simvastatin before DES implantation failed to improve arterial healing and endothelialization compared to treatment after stenting. PMID:25810732

  2. An Ultrasound Image-Based Dynamic Fusion Modeling Method for Predicting the Quantitative Impact of In Vivo Liver Motion on Intraoperative HIFU Therapies: Investigations in a Porcine Model

    PubMed Central

    N'Djin, W. Apoutou; Chapelon, Jean-Yves; Melodelima, David

    2015-01-01

    Organ motion is a key component in the treatment of abdominal tumors by High Intensity Focused Ultrasound (HIFU), since it may influence the safety, efficacy and treatment time. Here we report the development in a porcine model of an Ultrasound (US) image-based dynamic fusion modeling method for predicting the effect of in vivo motion on intraoperative HIFU treatments performed in the liver in conjunction with surgery. A speckle tracking method was used on US images to quantify in vivo liver motions occurring intraoperatively during breathing and apnea. A fusion modeling of HIFU treatments was implemented by merging dynamic in vivo motion data in a numerical modeling of HIFU treatments. Two HIFU strategies were studied: a spherical focusing delivering 49 juxtapositions of 5-second HIFU exposures and a toroidal focusing using 1 single 40-second HIFU exposure. Liver motions during breathing were spatially homogenous and could be approximated to a rigid motion mainly encountered in the cranial-caudal direction (f = 0.20Hz, magnitude >13mm). Elastic liver motions due to cardiovascular activity, although negligible, were detectable near millimeter-wide sus-hepatic veins (f = 0.96Hz, magnitude <1mm). The fusion modeling quantified the deleterious effects of respiratory motions on the size and homogeneity of a standard “cigar-shaped” millimetric lesion usually predicted after a 5-second single spherical HIFU exposure in stationary tissues (Dice Similarity Coefficient: DSC<45%). This method assessed the ability to enlarge HIFU ablations during respiration, either by juxtaposing “cigar-shaped” lesions with spherical HIFU exposures, or by generating one large single lesion with toroidal HIFU exposures (DSC>75%). Fusion modeling predictions were preliminarily validated in vivo and showed the potential of using a long-duration toroidal HIFU exposure to accelerate the ablation process during breathing (from 0.5 to 6 cm3·min-1). To improve HIFU treatment control

  3. Hydrometeorological network for flood monitoring and modeling

    NASA Astrophysics Data System (ADS)

    Efstratiadis, Andreas; Koussis, Antonis D.; Lykoudis, Spyros; Koukouvinos, Antonis; Christofides, Antonis; Karavokiros, George; Kappos, Nikos; Mamassis, Nikos; Koutsoyiannis, Demetris

    2013-08-01

    Due to its highly fragmented geomorphology, Greece comprises hundreds of small- to medium-size hydrological basins, in which often the terrain is fairly steep and the streamflow regime ephemeral. These are typically affected by flash floods, occasionally causing severe damages. Yet, the vast majority of them lack flow-gauging infrastructure providing systematic hydrometric data at fine time scales. This has obvious impacts on the quality and reliability of flood studies, which typically use simplistic approaches for ungauged basins that do not consider local peculiarities in sufficient detail. In order to provide a consistent framework for flood design and to ensure realistic predictions of the flood risk -a key issue of the 2007/60/EC Directive- it is essential to improve the monitoring infrastructures by taking advantage of modern technologies for remote control and data management. In this context and in the research project DEUCALION, we have recently installed and are operating, in four pilot river basins, a telemetry-based hydro-meteorological network that comprises automatic stations and is linked to and supported by relevant software. The hydrometric stations measure stage, using 50-kHz ultrasonic pulses or piezometric sensors, or both stage (piezometric) and velocity via acoustic Doppler radar; all measurements are being temperature-corrected. The meteorological stations record air temperature, pressure, relative humidity, wind speed and direction, and precipitation. Data transfer is made via GPRS or mobile telephony modems. The monitoring network is supported by a web-based application for storage, visualization and management of geographical and hydro-meteorological data (ENHYDRIS), a software tool for data analysis and processing (HYDROGNOMON), as well as an advanced model for flood simulation (HYDROGEIOS). The recorded hydro-meteorological observations are accessible over the Internet through the www-application. The system is operational and its

  4. High-resolution structural model of porcine P2 myelin membrane protein with associated fatty acid ligand: fact or artifact?

    PubMed

    Sedzik, Jan; Jastrzebski, Jan Pawel

    2011-06-01

    Myelin membrane is a biological complex of glial cells origin; it is composed of 25% (w/w) proteins and 75% lipids, and more than 300 proteins are associated with central nervous system myelin (for peripheral nervous system myelin, such data are lacking). Myelin plays an important role in maintaining propagation of nerve signals. To uncover the nature of propagation phenomena, it is essential to study biochemistry of myelin proteins and lipids, myelin composition, and myelin structure. Nearly all myelin proteins are like antigens, causing clinically well-defined devastating diseases; multiple sclerosis and Guillain-Barré syndrome are two of them. In this article, a high-resolution study (1.8 Å) of porcine myelin P2 protein is presented. Myelin was purified from porcine intradural spinal roots, which were stored at -80°C for 10 years before myelin and P2 protein were purified (spinal roots were a gift of Prof. Kunio Kitamura, Saitama Medical School). The three-dimensional structural analysis uncovered embedded 18-carbons-long fatty acid. Some speculative interpretation is presented, to uncover how this ligand of fatty acid may form cholesterol ester and stabilize the myelin structure or form simple raft microdomain. Protein crystallography indicates that the ligand may be 18-carbons-long fatty acid. This is unlike previous work with mass spectrometry, in which three ligands were determined. In other protein crystallography-based studies of P2 (bovine), an oleic fatty acid was suggested, but, for recombinant (human) protein, palmitic acid was found. There is no fatty acid ligand in equine P2 protein. PMID:21425316

  5. Safety of Porcine Reproductive and Respiratory Syndrome Modified Live Virus (MLV) vaccine strains in a young pig infection model

    PubMed Central

    2013-01-01

    The objective of this study was to compare the safety of all modified live virus vaccines commercially available in Europe against Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) under the same experimental conditions. For this purpose, one hundred and twenty three-week-old piglets, divided into five groups, were used. On day 0 of the experiment, nine pigs per group were removed and the remaining fifteen were vaccinated with the commercial vaccines Ingelvac PRRS MLV, Amervac PRRS, Pyrsvac-183 and Porcilis PRRS by the IM route or were mock vaccinated and used as controls. On day 3, the nine unvaccinated pigs were re-introduced into their respective groups and served as sentinel pigs. Clinical signs were recorded daily and lung lesions were determined on days 7, 14 and 21, when 5 vaccinated pigs per group were euthanized. Blood samples and swabs were taken every three days and different organs were collected at necropsy to determine the presence of PRRSV. None of the vaccines studied caused detectable clinical signs in vaccinated pigs although lung lesions were found. Altogether, these results indicate that all vaccines can be considered clinically safe. However, some differences were found in virological parameters. Thus, neither Pyrsvac-183 nor Porcilis PRRS could be detected in porcine alveolar macrophage (PAM) cultures or in lung sections used to determine PRRSV by immunohistochemistry, indicating that these viruses might have lost their ability to replicate in PAM. This inability to replicate in PAM might be related to the lower transmission rate and the delay in the onset of viremia observed in these groups PMID:24308693

  6. Biodegradable elastic patch plasty ameliorates left ventricular adverse remodeling after ischemia–reperfusion injury: A preclinical study of a porous polyurethane material in a porcine model

    PubMed Central

    Hashizume, Ryotaro; Fujimoto, Kazuro L.; Hong, Yi; Guan, Jianjun; Toma, Catalin; Tobita, Kimimasa; Wagner, William R.

    2013-01-01

    Objective Myocardial infarction (MI) can lead to irreversible adverse left ventricular remodeling resulting in subsequent severe dysfunction. The objective of this study was to investigate the potential for biodegradable, elastomeric patch implantation to positively alter the remodeling process after MI in a porcine model. Methods Yorkshire pigs underwent a 60-minute catheter balloon occlusion of the left circumflex artery. Two weeks after MI animals underwent epicardial placement of a biodegradable, porous polyurethane (poly(ester urethane)urea; PEUU) patch (MI+PEUU, n = 7) or sham surgery (MI+sham, n = 8). Echocardiography before surgery and at 4 and 8 weeks after surgery measured the end-diastolic area (EDA) and fractional area change (% FAC). All animals were humanely killed 8 weeks after surgery and hearts were histologically assessed. Results At 8 weeks, echocardiography revealed greater EDA values in the MI+sham group (23.6 ± 6.6 cm2 , mean ± standard deviaation) than in the MI+PEUU group (15.9 ± 2.5 cm2) (P < .05) and a lower %FAC in the MI+sham group (24.8 ± 7.6) than in the MI+PEUU group (35.9 ± 7.8) (P < .05). The infarcted ventricular wall was thicker in the MI+PEUU group (1.56 ± 0.5 cm) than in the MI+sham group (0.91 ± 0.24 cm) (P < .01). Conclusions Biodegradable elastomeric PEUU patch implantation onto the porcine heart 2 weeks post-MI attenuated left ventricular adverse remodeling and functional deterioration and was accompanied by increased neovascularization. These findings, although limited to a 2-month follow-up, may suggest an attractive clinical option to moderate post-MI cardiac failure. PMID:23219497

  7. Corneal-Protective Effects of an Artificial Tear Containing Sodium Hyaluronate and Castor Oil on a Porcine Short-Term Dry Eye Model

    PubMed Central

    HASEGAWA, Takashi; AMAKO, Hideki; YAMAMOTO, Takeshi; TAZAWA, Mariko; SAKAMOTO, Yuji

    2014-01-01

    ABSTRACT 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. PMID:24881653

  8. 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.

    PubMed

    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) . PMID:21590723

  9. Atmospheric corrosion model and monitor for low cost solar arrays

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.; Mansfeld, F. B.; Jeanjaquet, S. L.; Kendig, M.

    1981-01-01

    An atmospheric corrosion model and corrosion monitoring system has been developed for low cost solar arrays (LSA). The corrosion model predicts that corrosion rate is the product of the surface condensation probability of water vapor and the diffusion controlled corrosion current. This corrosion model is verified by simultaneous monitoring of weather conditions and corrosion rates at the solar array test site at Mead, Nebraska.

  10. Modeling the effect of experimental variables on the in vitro permeation of six model compounds across porcine skin.

    PubMed

    Karadzovska, Daniela; Brooks, James D; Riviere, Jim E

    2013-02-25

    A majority of quantitative structure-permeability relationships (QSPeRs) predict the permeability coefficient (k(p)) of compounds topically applied as infinite, saturated doses from water vehicles. Alternate delivery vehicles and other experimental variables are rarely incorporated in such models. This research presents the development and statistical validation of QSPeR models that incorporate the effects of penetrant, vehicle, and experimental conditions such as dose volume (finite/infinite), and saturation level (saturated/unsaturated). A composite parameter, a mixture factor (MF), was also included to account for the physicochemical properties of the compound/vehicle mixture components. The resultant models effectively described skin flux and absorption, identifying the summation of hydrogen bond acidity and basicity, excess molar refractivity, dose volume, saturation level, and vehicle as the most prominent factors influencing flux values. The main factors influencing absorption values were the summation of hydrogen bond basicity, dipolarity/polarizability, the McGowan characteristic volume, dose volume, saturation level, and vehicle. The same MF (inverse of the melting point) was considered suitable to describe both flux and absorption. For endpoints involving skin deposition, log propylene glycol solubility was a more suitable MF. Such models show potential for use in drug delivery and toxicology research, specifically in assessing percutaneous absorption data collected under different experimental conditions. PMID:23313919

  11. Novel Sensor-Enabled Ex Vivo Bioreactor: A New Approach towards Physiological Parameters and Porcine Artery Viability

    PubMed Central

    Mundargi, Raghavendra; Venkataraman, Divya; Kumar, Saranya; Mogal, Vishal; Ortiz, Raphael; Loo, Joachim; Venkatraman, Subbu; Steele, Terry

    2015-01-01

    The aim of the present work is to design and construct an ex vivo bioreactor system to assess the real time viability of vascular tissue. Porcine carotid artery as a model tissue was used in the ex vivo bioreactor setup to monitor its viability under physiological conditions such as oxygen, pressure, temperature, and flow. The real time tissue viability was evaluated by monitoring tissue metabolism through a fluorescent indicator “resorufin.” Our ex vivo bioreactor allows real time monitoring of tissue responses along with physiological conditions. These ex vivo parameters were vital in determining the tissue viability in sensor-enabled bioreactor and our initial investigations suggest that, porcine tissue viability is considerably affected by high shear forces and low oxygen levels. Histological evaluations with hematoxylin and eosin and Masson's trichrome staining show intact endothelium with fresh porcine tissue whereas tissues after incubation in ex vivo bioreactor studies indicate denuded endothelium supporting the viability results from real time measurements. Hence, this novel viability sensor-enabled ex vivo bioreactor acts as model to mimic in vivo system and record vascular responses to biopharmaceutical molecules and biomedical devices. PMID:26609536

  12. Absolute Cerebral Blood Flow Infarction Threshold for 3-Hour Ischemia Time Determined with CT Perfusion and 18F-FFMZ-PET Imaging in a Porcine Model of Cerebral Ischemia

    PubMed Central

    Cockburn, Neil; Kovacs, Michael

    2016-01-01

    CT Perfusion (CTP) derived cerebral blood flow (CBF) thresholds have been proposed as the optimal parameter for distinguishing the infarct core prior to reperfusion. Previous threshold-derivation studies have been limited by uncertainties introduced by infarct expansion between the acute phase of stroke and follow-up imaging, or DWI lesion reversibility. In this study a model is proposed for determining infarction CBF thresholds at 3hr ischemia time by comparing contemporaneously acquired CTP derived CBF maps to 18F-FFMZ-PET imaging, with the objective of deriving a CBF threshold for infarction after 3 hours of ischemia. Endothelin-1 (ET-1) was injected into the brain of Duroc-Cross pigs (n = 11) through a burr hole in the skull. CTP images were acquired 10 and 30 minutes post ET-1 injection and then every 30 minutes for 150 minutes. 370 MBq of 18F-FFMZ was injected ~120 minutes post ET-1 injection and PET images were acquired for 25 minutes starting ~155–180 minutes post ET-1 injection. CBF maps from each CTP acquisition were co-registered and converted into a median CBF map. The median CBF map was co-registered to blood volume maps for vessel exclusion, an average CT image for grey/white matter segmentation, and 18F-FFMZ-PET images for infarct delineation. Logistic regression and ROC analysis were performed on infarcted and non-infarcted pixel CBF values for each animal that developed infarct. Six of the eleven animals developed infarction. The mean CBF value corresponding to the optimal operating point of the ROC curves for the 6 animals was 12.6 ± 2.8 mL·min-1·100g-1 for infarction after 3 hours of ischemia. The porcine ET-1 model of cerebral ischemia is easier to implement then other large animal models of stroke, and performs similarly as long as CBF is monitored using CTP to prevent reperfusion. PMID:27347877

  13. Interactions of porcine circovirus 2 with its hosts.

    PubMed

    Ren, Linzhu; Chen, Xinrong; Ouyang, Hongsheng

    2016-08-01

    Porcine circovirus 2 (PCV2) can cause porcine circovirus diseases and porcine circovirus-associated diseases (PCVD/PCVAD), which are widely presented in swine-producing countries. Since the discovery of this virus, considerable efforts have been devoted to understanding this pathogen and its interactions with its host. Here, we review the current state of knowledge on interactions between host cell factors and PCV2 with respect to viral proliferation, virus-induced cell apoptosis and autophagy, and host antiviral defenses during PCV2 infection. We also review mouse model systems for PCV2 infection. PMID:27016220

  14. Pulse Oximetry: A Non-Invasive, Novel Marker for the Quality of Chest Compressions in Porcine Models of Cardiac Arrest

    PubMed Central

    Han, Fei; Li, Yan; Walline, Joseph; Fu, Yangyang; Yao, Dongqi; Zhang, Xiaocui; Zhang, Hui; Zhu, Huadong; Guo, Shubin; Wang, Zhong; Yu, Xuezhong

    2015-01-01

    Objective Pulse oximetry, which noninvasively detects the blood flow of peripheral tissue, has achieved widespread clinical use. We have noticed that the better the quality of cardiopulmonary resuscitation (CPR), the better the appearance of pulse oximetry plethysmographic waveform (POP). We investigated whether the area under the curve (AUC) and/or the amplitude (Amp) of POP could be used to monitor the quality of CPR. Design Prospective, randomized controlled study. Setting Animal experimental center in Peking Union Medical Collage Hospital, Beijing, China. Subjects Healthy 3-month-old male domestic swine. Interventions 34 local pigs were enrolled in this study. After 4 minutes of untreated ventricular fibrillation, animals were randomly assigned into two resuscitation groups: a “low quality” group (with a compression depth of 3cm) and a “high quality” group (with a depth of 5cm). All treatments between the two groups were identical except for the depth of chest compressions. Hemodynamic parameters [coronary perfusion pressure (CPP), partial pressure of end-tidal carbon dioxide (PETCO2)] as well as AUC and Amp of POP were all collected and analyzed. Measurements and Findings There were statistical differences between the “high quality” group and the “low quality” group in AUC, Amp, CPP and PETCO2 during CPR (P<0.05). AUC, Amp and CPP were positively correlated with PETCO2, respectively (P<0.01). There was no statistical difference between the heart rate calculated according to the POP (FCPR) and the frequency of mechanical CPR at the 3rd minute of CPR. The FCPR was lower than the frequency of mechanical CPR at the 6th and the 9th minute of CPR. Conclusions Both the AUC and Amp of POP correlated well with CPP and PETCO2 in animal models. The frequency of POP closely matched the CPR heart rate. AUC and Amp of POP might be potential noninvasive quality monitoring markers for CPR. PMID:26485651

  15. Stability of Reference Gene Expression After Porcine Sapelovirus Infection in Porcine Intestinal Epithelial Cells.

    PubMed

    Huang, Yong; Chen, Yabing; Sun, Huan; Lan, Daoliang

    2016-01-01

    Intestinal epithelial cells, which serve as the first physical barrier to protect intestinal tract from external antigens, have an important role in the local innate immunity. Screening of reference genes that have stable expression levels after viral infection in porcine intestinal epithelial cells is critical for ensuring the reliability of the expression analysis on anti-infection genes in porcine intestinal epithelial cells. In this study, nine common reference genes in pigs, including ACTB, B2M, GAPDH, HMBS, SDHA, HPRT1, TBP, YWHAZ, and RPL32, were chosen as the candidate reference genes. Porcine sapelovirus (PSV) was used as a model virus to infect porcine intestinal epithelial cell line (IPEC-J2). The expression stability of the nine genes was assessed by the geNorm, NormFinder, and BestKeeper software. Moreover, RefFinder program was used to evaluate the analytical results of above three softwares, and a relative expression experiment of selected target gene was used to verify the analysis results. The comprehensive results indicated that the gene combination of TBP and RPL32 has the most stable expression, which could be considered as an appropriate reference gene for research on gene expression after PSV infection in IPEC-J2cells. The results provided essential data for expression analysis of anti-infection genes in porcine intestinal epithelial cells. PMID:27092424

  16. GABAA and GABAC receptors in adult porcine cones: evidence from a photoreceptor–glia co-culture model

    PubMed Central

    Picaud, Serge; Pattnaik, Bikash; Hicks, David; Forster, Valérie; Fontaine, Valérie; Sahel, José; Dreyfus, Henri

    1998-01-01

    Edge contrast enhancement is an integrated visual function based on the complex centre-surround organization of the cone photoreceptor light response. While centre responses result from direct light activation, surround responses are thought to result from lateral inhibition mediated by horizontal cells. This feedback signal has been attributed to GABAA receptors which have been found in lower vertebrate cones. In order to study the GABA response of adult mammalian photoreceptors, we designed a culture system consisting of isolated photoreceptors seeded on a layer of retinal glial cells. Mature rods and cones required the presence of Müller glial cells to survive and develop neurites; they degenerated in the absence of glial cells. Cone photoreceptors generated large GABA responses whereas rod photoreceptors did not respond to GABA applications. Cone GABA responses consisted of two distinct components, one suppressed by the GABAA receptor blockers bicuculline and SR95531, and the second by the GABAC receptor antagonists TPMPA and imidazole-4-acetic acid (I4AA). Pentobarbital greatly increased the GABAA receptor component whereas it did not affect, or even reduced, the GABAC receptor component. During long GABA applications, GABAA receptor currents desensitized by 78 %, contrasting with the sustained GABAC response. Expression of GABAC receptors in cone photoreceptors was confirmed by anti-ρ-subunit immunolabelling of porcine retinal sections. These results indicate that both GABAA and GABAC receptors may participate in the feedback synapse from horizontal cells to cone photoreceptors in the mammalian retina. PMID:9782157

  17. Biomechanical comparison of different combinations of hook and screw in one spine motion unit - an experiment in porcine model

    PubMed Central

    2014-01-01

    Background The biomechanical performance of the hooks and screws in spinal posterior instrumentation is not well-characterized. Screw-bone interface failure at the uppermost and lowermost vertebrae is not uncommon. Some have advocated for the use of supplement hooks to prevent screw loosening. However, studies describing methods for combined hook and screw systems that fully address the benefits of these systems are lacking. Thus, the choice of which implant to use in a given case is often based solely on a surgeon’s experience instead of on the biomechanical features and advantages of each device. Methods We conducted a biomechanical comparison of devices instrumented with different combinations of hooks and screws. Thirty-six fresh low thoracic porcine spines were assigned to three groups (12 per group) according to the configuration used for of fixation: (1) pedicle screw; (2) lamina hook and (3) combination of pedicle screw and lamina hook. Axial pullout tests backward on transverse plane in the direction normal to the rods were performed using a material testing machine and a specially designed grip with self-aligned function. Results The pullout force for the pedicle screws group was significantly greater than for the hooks and the combination (p < 0.05). However, no significant difference was found between the hooks and the combination (p > 0.05). Conclusions Pedicle screws achieve the maximal pullout strength for spinal posterior instrumentation. PMID:24913189

  18. A Porcine Animal Model for Early Meniscal Degeneration – Analysis of Histology, Gene Expression and Magnetic Resonance Imaging Six Months after Resection of the Anterior Cruciate Ligament

    PubMed Central

    Kreinest, Michael; Reisig, Gregor; Ströbel, Philipp; Dinter, Dietmar; Attenberger, Ulrike; Lipp, Peter; Schwarz, Markus

    2016-01-01

    Background/Objective The menisci of the mammalian knee joint balance the incongruence between femoral condyle and tibial plateau and thus menisci absorb and distribute high loads. Degeneration processes of the menisci lead to pain syndromes in the knee joint. The origin of such degenerative processes on meniscal tissue is rarely understood and may be described best as an imbalance of anabolic and catabolic metabolism. A standardized animal model of meniscal degeneration is needed for further studies. The aim of the current study was to develop a porcine animal model with early meniscal degeneration. Material and Methods Resection of the anterior cruciate ligament (ACLR) was performed on the left knee joints of eight Göttingen minipigs. A sham operation was carried out on the right knee joint. The grade of degeneration was determined 26 weeks after the operation using histology and magnetic resonance imaging (MRI). Furthermore, the expression of 14 genes which code for extracellular matrix proteins, catabolic matrix metalloproteinases and inflammation mediators were analyzed. Results Degenerative changes were detected by a histological analysis of the medial meniscus after ACLR. These changes were not detected by MRI. In terms of their gene expression profile, these degenerated medial menisci showed a significantly increased expression of COL1A1. Conclusion This paper describes a new animal model for early secondary meniscal degeneration in the Göttingen minipig. Histopathological evidence of the degenerative changes could be described. This early degenerative changes could not be seen by NMR imaging. PMID:27434644

  19. Cardiac repair in a porcine model of acute myocardial infarction with human induced pluripotent stem cell-derived cardiovascular cell populations

    PubMed Central

    Ye, Lei; Chang, Ying-Hua; Xiong, Qiang; Zhang, Pengyuan; Zhang, Liying; Somasundaram, Porur; Lepley, Mike; Swingen, Cory; Su, Liping; Wendel, Jacqueline S.; Guo, Jing; Jang, Albert; Rosenbush, Daniel; Greder, Lucas; Dutton, James R.; Zhang, Jianhua; Kamp, Timothy J.; Kaufman, Dan S.; Ge, Ying; Zhang, Jianyi

    2014-01-01

    Summary Human induced pluripotent stem cells (hiPSCs) hold promise for myocardial repair following injury, but preclinical studies in large animal models are required to determine optimal cell preparation and delivery strategies to maximize functional benefits and to evaluate safety. Here, we utilized a porcine model of acute myocardial infarction (MI) to investigate the functional impact of intramyocardial transplantation of hiPSC-derived cardiomyocytes, endothelial cells, and smooth muscle cells, in combination with a 3D fibrin patch loaded with insulin growth factor (IGF)-encapsulated microspheres. hiPSC-derived cardiomyocytes integrated into host myocardium and generated organized sarcomeric structures, and endothelial and smooth muscle cells contributed to host vasculature. Tri-lineage cell transplantation significantly improved left ventricular function, myocardial metabolism, and arteriole density, while reducing infarct size, ventricular wall stress and apoptosis without inducing ventricular arrhythmias. These findings in a large animal MI model highlight the potential of utilizing hiPSC-derived cells for cardiac repair. PMID:25479750

  20. A novel culture system for adult porcine intestinal crypts.

    PubMed

    Khalil, Hassan A; Lei, Nan Ye; Brinkley, Garrett; Scott, Andrew; Wang, Jiafang; Kar, Upendra K; Jabaji, Ziyad B; Lewis, Michael; Martín, Martín G; Dunn, James C Y; Stelzner, Matthias G

    2016-07-01

    Porcine models are useful for investigating therapeutic approaches to short bowel syndrome and potentially to intestinal stem cell (ISC) transplantation. Whereas techniques for the culture and genetic manipulation of ISCs from mice and humans are well established, similar methods for porcine stem cells have not been reported. Jejunal crypts were isolated from murine, human, and juvenile and adult porcine small intestine, suspended in Matrigel, and co-cultured with syngeneic intestinal subepithelial myofibroblasts (ISEMFs) or cultured without feeder cells in various culture media. Media containing epidermal growth factor, noggin, and R-spondin 1 (ENR medium) were supplemented with various combinations of Wnt3a- or ISEMF-conditioned medium (CM) and with glycogen synthase kinase 3 inhibitor (GSK3i), and their effects were studied on cultured crypts. Cell lineage differentiation was assessed by immunohistochemistry and quantitative polymerase chain reaction. Cultured porcine cells were serially passaged and transduced with a lentiviral vector. Whereas ENR medium supported murine enteroid growth, it did not sustain porcine crypts beyond 5 days. Supplementation of Wnt3a-CM and GSK3i resulted in the formation of complex porcine enteroids with budding extensions. These enteroids contained a mixture of stem and differentiated cells and were successfully passaged in the presence of GSK3i. Crypts grown in media supplemented with porcine ISEMF-CM formed spheroids that were less well differentiated than enteroids. Enteroids and spheroids were transfected with a lentivirus with high efficiency. Thus, our method maintains juvenile and adult porcine crypt cells long-term in culture. Porcine enteroids and spheroids can be successfully passaged and transduced by using lentiviral vectors. PMID:26928041

  1. Splicing variants of porcine synphilin-1.

    PubMed

    Larsen, Knud; Madsen, Lone Bruhn; Farajzadeh, Leila; Bendixen, Christian

    2015-09-01

    Parkinson's disease (PD), idiopathic and familial, is characterized by degradation of dopaminergic neurons and the presence of Lewy bodies (LB) in the substantia nigra. LBs contain aggregated proteins of which α-synuclein is the major component. The protein synphilin-1 interacts and colocalizes with α-synuclein in LBs. The aim of this study was to isolate and characterize porcine synphilin-1 and isoforms hereof with the future perspective to use the pig as a model for Parkinson's disease. The porcine SNCAIP cDNA was cloned by reverse transcriptase PCR. The spatial expression of SNCAIP mRNA was investigated by RNAseq. The presented work reports the molecular cloning and characterization of the porcine (Sus scrofa) synphilin-1 cDNA (SNCAIP) and three splice variants hereof. The porcine SNCAIP cDNA codes for a protein (synphilin-1) of 919 amino acids which shows a high similarity to human (90%) and to mouse (84%) synphilin-1. Three shorter transcript variants of the synphilin-1 gene were identified, all lacking one or more exons. SNCAIP transcripts were detected in most examined organs and tissues and the highest expression was found in brain tissues and lung. Conserved splicing variants and a novel splice form of synhilin-1 were found in this study. All synphilin-1 isoforms encoded by the identified transcript variants lack functional domains important for protein degradation. PMID:26101749

  2. Modeling Behavioral Measures of Error Detection in Choice Tasks: Response Monitoring versus Conflict Monitoring

    ERIC Educational Resources Information Center

    Steinhauser, Marco; Maier, Martin; Hubner, Ronald

    2008-01-01

    The present study investigated the mechanisms underlying error detection in the error signaling response. The authors tested between a response monitoring account and a conflict monitoring account. By implementing each account within the neural network model of N. Yeung, M. M. Botvinick, and J. D. Cohen (2004), they demonstrated that both accounts…

  3. Porcine Head Response to Blast

    PubMed Central

    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 (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  4. Mathematical models and lymphatic filariasis control: monitoring and evaluating interventions.

    PubMed

    Michael, Edwin; Malecela-Lazaro, Mwele N; Maegga, Bertha T A; Fischer, Peter; Kazura, James W

    2006-11-01

    Monitoring and evaluation are crucially important to the scientific management of any mass parasite control programme. Monitoring enables the effectiveness of implemented actions to be assessed and necessary adaptations to be identified; it also determines when management objectives are achieved. Parasite transmission models can provide a scientific template for informing the optimal design of such monitoring programmes. Here, we illustrate the usefulness of using a model-based approach for monitoring and evaluating anti-parasite interventions and discuss issues that need addressing. We focus on the use of such an approach for the control and/or elimination of the vector-borne parasitic disease, lymphatic filariasis. PMID:16971182

  5. Analysis of different routes of administration of heterologous 5-azacytidine-treated mesenchymal stem cells in a porcine model of myocardial infarction.

    PubMed

    Moscoso, I; Barallobre, J; de Ilarduya, O M; Añón, P; Fraga, M; Calviño, R; Aldama, G; Doménech, N

    2009-01-01

    Stem cell therapy constitutes an exciting, powerful therapy to repair the heart. Nevertheless, there are numerous doubts about the best route of stem cell administration to achieve implantation into the injured myocardium. Development of a preclinical, large animal model may be useful to obtain a better approach to clinical situations. The aim of this work was to study the effectiveness of various routes of heterologous bone marrow mesenchymal stem cell (MSCs) administration in a porcine model of myocardial infarction. MSC treated with 5-azacytidine were stained with a fluorescent compound (DiO) before their administration to previously infarcted pigs via 3 routes: intracoronary (IC), intramyocardial (IM), or endocardial (EC; n = 5 each group). Healthy, noninfarcted animals were used as a control group. At 30 days after delivery, hearts were divided into 12 parts: infarcted zone (1-6), right-left atria, interatrial and interventricular septa, and right-left ventricles. In each zone we looked for and quantified, injected fluorescence-stained cells. In the animals in which presence of DiO-stained cells was detected, cells were located preferentially in the infarcted zone and not in the atria, ventricles, or septa. Comparing various administration routes, the mean number of engrafted cells within the infarct zone was significantly greater after IC infusion than either IM or EC injection. Fluorescent cells were not observed in healthy zones of the myocardium or in healthy animals. PMID:19715895

  6. Time-dependent image changes after ethanol injection into the pancreas: an experimental study using a porcine model

    PubMed Central

    Matsumoto, Kazuyuki; Kato, Hironari; Tsutsumi, Koichiro; Fushimi, Soichiro; Iwamuro, Masaya; Oda, Shinsuke; Mizukawa, Sho; Akimoto, Yutaka; Uchida, Daisuke; Tomoda, Takeshi; Yamamoto, Naoki; Horiguchi, Shigeru; Okada, Hiroyuki

    2016-01-01

    Background Ethanol, a commonly available agent, has been used to successfully ablate cystic and solid lesions in the pancreas. The aim of this study is to investigate the effects of an ethanol injection into the porcine pancreas and observe the time-dependent image changes in the pancreatic parenchyma. Methods Pure ethanol was injected into the pancreatic tail using a 25-gauge EUS needle with direct ultrasound guidance under celiotomy: 1 mL and 2 mL were injected, respectively. The abdomen was closed after the injection. MRI was performed before the procedure, immediately after, and on postoperative day (POD) seven. Blood samples were taken before the procedure and on PODs one, three, five, and seven. The pigs were euthanised on POD seven. Results Immediately after the injection, linear high signal areas in the pancreatic tail on T2 and rounded speckled high signal areas on DWI images were detected in both animals, measuring 35 × 32 mm in the 1 mL injected pig and 42 × 38mm in the 2 mL injected pig. After POD seven, rounded high signal areas were noted on T2 images, measuring 22 × 18 mm and 36 × 28 mm respectively. On POD one, the 1 mL injected animal had a 53% elevation in serum amylase while the 2 mL injected animal had a 66% elevation. Histologically, cystic and necrotic changes in the parenchyma were observed, measuring 23 × 22 mm and 40 × 35 mm respectively. Conclusions Our results, which are limited to normal pancreas, suggested that a 1 mL injection caused localised changes within the pancreas while a 2 mL injection induced more widespread changes beyond the pancreas. The effective area of ethanol was widespread immediately after injection, and then the area was reduced with cystic and necrosis changes. PMID:27594908

  7. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    PubMed

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design. PMID:26737430

  8. Development of a network based model to simulate the between-farm transmission of the porcine reproductive and respiratory syndrome virus.

    PubMed

    Thakur, Krishna K; Sanchez, Javier; Hurnik, Daniel; Poljak, Zvonimir; Opps, Sheldon; Revie, Crawford W

    2015-11-18

    Contact structure within a population can significantly affect the outcomes of infectious disease spread models. The objective of this study was to develop a network based simulation model for the between-farm spread of porcine reproductive and respiratory syndrome virus to assess the impact of contact structure on between-farm transmission of PRRS virus. For these farm level models, a hypothetical population of 500 swine farms following a multistage production system was used. The contact rates between farms were based on a study analyzing movement of pigs in Canada, while disease spread parameters were extracted from published literature. Eighteen distinct scenarios were designed and simulated by varying the mode of transmission (direct versus direct and indirect contact), type of index herd (farrowing, nursery and finishing), and the presumed network structures among swine farms (random, scale-free and small-world). PRRS virus was seeded in a randomly selected farm and 500 iterations of each scenario were simulated for 52 weeks. The median epidemic size by the end of the simulated period and percentage die-out for each scenario, were the key outcomes captured. Scenarios with scale-free network models resulted in the largest epidemic sizes, while scenarios with random and small-world network models resulted in smaller and similar epidemic sizes. Similarly, stochastic die-out percentage was least for scenarios with scale-free networks followed by random and small-world networks. Findings of the study indicated that incorporating network structures among the swine farms had a considerable impact on the spread of PRRS virus, highlighting the importance of understanding and incorporating realistic contact structures when developing infectious disease spread models for similar populations. PMID:26464321

  9. Functional Genomics Unique to Week 20 Post Wounding in the Deep Cone/Fat Dome of the Duroc/Yorkshire Porcine Model of Fibroproliferative Scarring

    PubMed Central

    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.

    2011-01-01

    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. PMID:21533106

  10. Self-calibrating models for dynamic monitoring and diagnosis

    NASA Technical Reports Server (NTRS)

    Kuipers, Benjamin

    1996-01-01

    A method for automatically building qualitative and semi-quantitative models of dynamic systems, and using them for monitoring and fault diagnosis, is developed and demonstrated. The qualitative approach and semi-quantitative method are applied to monitoring observation streams, and to design of non-linear control systems.

  11. Comparison of gene expression profiles in a porcine infarct model after intracoronary, transthoracic, or transendocardiac injection of heterologous bone marrow mesenchymal cells.

    PubMed

    Barallobre-Barreiro, J; de Ilárduya, O M; Moscoso, I; Calviño, R; Aldama, G; López-Peláez, E; Centeno, A; Doménech, N

    2009-01-01

    An in vivo porcine model of myocardial infarction was developed with the aim of comparing the effectiveness for cardiac repair of intracoronary, transthoracic, or transendocardial delivery strategies for bone marrow mesenchymal stem cells (BMMSC) using an analysis of expression levels of transcripts related to various cellular processes at 8 heart regions using quantitative reverse transcriptase polymerase chain reaction. We observed significant rises in cardiomyogenic markers Mef2C, Gata4 and Nkx2.5, and contractibility marker Serca2A at infarcted regions for cell-treated pigs. We also observed differences in Sdf1 expression related to the organ stress response between delivery strategies. Unexpectedly, increased expression of Col1A1 was detected in 2 cell-treated groups at various heart regions. Our results suggest improvements in both contractility and cardiomyogenic capability of damaged tissue after BMMSC injection, but also warned us about the relevance of the chosen delivery strategy and potential undesired effects like increasing fibrosis after treatment. PMID:19715897

  12. A porcine adenovirus with low human seroprevalence is a promising alternative vaccine vector to human adenovirus 5 in an H5N1 virus disease model.

    PubMed

    Patel, Ami; Tikoo, Suresh; Kobinger, Gary

    2010-01-01

    Human adenovirus 5 (AdHu5) vectors are robust vaccine platforms however the presence of naturally-acquired neutralizing antibodies may reduce vector efficacy and potential for re-administration. This study evaluates immune responses and protection following vaccination with a replication-incompetent porcine adenovirus 3 (PAV3) vector as an alternative vaccine to AdHu5 using an avian influenza H5N1 disease model. Vaccine efficacy was evaluated in BALB/c mice following vaccination with different doses of the PAV3 vector expressing an optimized A/Hanoi/30408/2005 H5N1 hemagglutinin antigen (PAV3-HA) and compared with an AdHu5-HA control. PAV3-HA rapidly generated antibody responses, with significant neutralizing antibody titers on day 21, and stronger cellular immune responses detected on day 8, compared to AdHu5-HA. The PAV3-HA vaccine, administered 8 days before challenge, demonstrated improved survival and lower virus load. Evaluation of long-term vaccine efficacy at 12 months post-vaccination showed better protection with the PAV3-HA than with the AdHu5-HA vaccine. Importantly, as opposed to AdHu5, PAV3 vector was not significantly neutralized by human antibodies pooled from over 10,000 individuals. Overall, PAV3-based vector is capable of mediating swift, strong immune responses and offer a promising alternative to AdHu5. PMID:21179494

  13. Vascular replacement using a layered elastin-collagen vascular graft in a porcine model: one week patency versus one month occlusion

    PubMed Central

    Koens, M J W; Krasznai, A G; Hanssen, A E J; Hendriks, T; Praster, R; Daamen, W F; van der Vliet, J A; van Kuppevelt, T H

    2015-01-01

    abstract A persistent clinical demand exists for a suitable arterial prosthesis. In this study, a vascular conduit mimicking the native 3-layered artery, and constructed from the extracellular matrix proteins type I collagen and elastin, was evaluated for its performance as a blood vessel equivalent. A tubular 3-layered graft (elastin-collagen-collagen) was prepared using highly purified type I collagen fibrils and elastin fibers, resembling the 3-layered native blood vessel architecture. The vascular graft was crosslinked and heparinised (37 ± 4 μg heparin/mg graft), and evaluated as a vascular graft using a porcine bilateral iliac artery model. An intra-animal comparison with clinically-used heparinised ePTFE (Propaten®) was made. Analyses included biochemical characterization, duplex scanning, (immuno)histochemistry and scanning electron microscopy. The tubular graft was easy to handle with adequate suturability. Implantation resulted in pulsating grafts without leakage. One week after implantation, both ePTFE and the natural acellular graft had 100% patencies on duplex scanning. Grafts were partially endothelialised (Von Willebrand-positive endothelium with a laminin-positive basal membrane layer). After one month, layered thrombi were found in the natural (4/4) and ePTFE graft (1/4), resulting in occlusion which in case of the natural graft is likely due to the porosity of the inner elastin layer. In vivo application of a molecularly-defined tubular graft, based on nature's matrix proteins, for vascular surgery is feasible. PMID:26060888

  14. Vascular replacement using a layered elastin-collagen vascular graft in a porcine model: one week patency versus one month occlusion.

    PubMed

    Koens, M J W; Krasznai, A G; Hanssen, A E J; Hendriks, T; Praster, R; Daamen, W F; van der Vliet, J A; van Kuppevelt, T H

    2015-01-01

    A persistent clinical demand exists for a suitable arterial prosthesis. In this study, a vascular conduit mimicking the native 3-layered artery, and constructed from the extracellular matrix proteins type I collagen and elastin, was evaluated for its performance as a blood vessel equivalent. A tubular 3-layered graft (elastin-collagen-collagen) was prepared using highly purified type I collagen fibrils and elastin fibers, resembling the 3-layered native blood vessel architecture. The vascular graft was crosslinked and heparinised (37 ± 4 μg heparin/mg graft), and evaluated as a vascular graft using a porcine bilateral iliac artery model. An intra-animal comparison with clinically-used heparinised ePTFE (Propaten®) was made. Analyses included biochemical characterization, duplex scanning, (immuno)histochemistry and scanning electron microscopy. The tubular graft was easy to handle with adequate suturability. Implantation resulted in pulsating grafts without leakage. One week after implantation, both ePTFE and the natural acellular graft had 100% patencies on duplex scanning. Grafts were partially endothelialised (Von Willebrand-positive endothelium with a laminin-positive basal membrane layer). After one month, layered thrombi were found in the natural (4/4) and ePTFE graft (1/4), resulting in occlusion which in case of the natural graft is likely due to the porosity of the inner elastin layer. In vivo application of a molecularly-defined tubular graft, based on nature's matrix proteins, for vascular surgery is feasible. PMID:26060888

  15. Intrinsic Monitoring Using Behaviour Models in IPv6 Networks

    NASA Astrophysics Data System (ADS)

    Höfig, Edzard; Coşkun, Hakan

    In conventional networks, correlating path information to resource utilisation on the granularity of packets is a hard problem when using policy-based traffic handling schemes. We introduce a new approach termed ‘intrinsic monitoring’ which relies on the use of IPv6 extension headers in combination with formal behaviour models to gather resource information along a path. This allows a network monitoring system to delegate monitoring functionality to the network devices themselves, with the result of a drastic reduction in management traffic due to the increased autonomy of the monitoring system. As monitoring information travels in-band with the network traffic, path information remains perfectly accurate.

  16. The porcine ear skin as a model system for the human integument: influence of storage conditions on basic features of epidermis structure and function--a histological and histochemical study.

    PubMed

    Meyer, W; Zschemisch, N H; Godynicki, S

    2003-01-01

    Based on careful tissue processing, detailed structural analysis, and histochemical as well as cytophotometrical evaluation of the epidermis, the study presents data with respect to changes of tissue integrity during two storing modes (room temperature and 4 degrees C) and various storage times of the porcine auricle. Structural degeneration was first noted in the barrier region of the epidermis from where such changes spread, independent of storage conditions, from small horizontal necrotic islands and continuously with increasing storage time. The histochemical results corroborated these observations, emphasizing, however, that the lower epidermal layers seemed intact for a longer time period than the upper layers. Cytophotometrical evaluation of histochemical stainings showed, with regard to the enzyme succinate dehydrogenase, that oxidative metabolism was negatively affected in the early stages of storage, whereas epidermal lipids (neutral fats, glycolipids) remained relatively stable, even during storage at room temperature. In conclusion, it was obvious that the barrier region is the most sensitive element of the porcine ear epidermis. Taking into consideration that this part of the epidermis is most important for permeation studies, it seems reasonable to avoid any storage of porcine auricles at room temperature, and to use only auricles that have been stored at 4 degrees C for not more than 4 to 6 hours, immediately after delivery from the slaughter-house. In this way better tissue preservation can be achieved, whereby the use of shinkage-free water-soluble plastic embedding would generally improve the histological control of structural integrity, and the application of an easy to handle enzyme histochemical procedure (e.g. succinate dehydrogenase demonstration) to unfixed fresh-frozen sections would help to control basic aspects of tissue functions. The results are discussed in relation to the use of porcine integument as a model in human dermatological

  17. Edelman's equation is valid in acute hyponatremia in a porcine model: plasma sodium concentration is determined by external balances of water and cations.

    PubMed

    Overgaard-Steensen, Christian; Larsson, Anders; Bluhme, Henrik; Tønnesen, Else; Frøkiaer, Jørgen; Ring, Troels

    2010-01-01

    Acute hyponatremia is a serious condition, which poses major challenges. Of particular importance is what determines plasma sodium concentration ([Na(+)]). Edelman introduced an explicit model to describe plasma [Na(+)] in a population as [Na(+)] = alpha.(exchangeable Na(+) + exchangeable K(+))/(total body water) - beta. Evidence for the clinical utility of the model in the individual and in acute hyponatremia is sparse. We, therefore, investigated how the measured plasma [Na(+)] could be predicted in a porcine model of hyponatremia. Plasma [Na(+)] was estimated from in vivo-determined balances of water, Na(+), and K(+), according to Edelman's equation. Acute hyponatremia was induced with desmopressin acetate and infusion of a 2.5% glucose solution in anesthetized pigs. During 480 min, plasma [Na(+)] and osmolality were reduced from 136 (SD 2) to 120 mmol/l (SD 3) and from 284 (SD 4) to 252 mosmol/kgH(2)O (SD 5), respectively. The following interpretations were made. First, Edelman's model, which, besides dilution, takes into account Na(+) and K(+), fits plasma [Na(+)] significantly better than dilution alone. Second, a common value of alpha = 1.33 (SD 0.08) and beta = -13.04 mmol/l (SD 7.68) for all pigs explains well the plasma [Na(+)] in the individual animal. Third, measured exchangeable Na(+) and calculated exchangeable Na(+) + K(+) per weight in the pigs are close to Edelman's findings in humans, whereby the methods are cross-validated. In conclusion, plasma [Na(+)] can be explained in the individual animal by external balances, according to Edelman's construct in acute hyponatremia. PMID:19864338

  18. Local delivery of allogeneic bone marrow and adipose tissue-derived mesenchymal stromal cells for cutaneous wound healing in a porcine model.

    PubMed

    Hanson, Summer E; Kleinbeck, Kyle R; Cantu, David; Kim, Jaeyhup; Bentz, Michael L; Faucher, Lee D; Kao, W John; Hematti, Peiman

    2016-02-01

    Wound healing remains a major challenge in modern medicine. Bone marrow- (BM) and adipose tissue- (AT) derived mesenchymal stromal/stem cells (MSCs) are of great interest for tissue reconstruction due to their unique immunological properties and regenerative potential. The purpose of this study was to characterize BM and AT-MSCs and evaluate their effect when administered in a porcine wound model. MSCs were derived from male Göttingen Minipigs and characterized according to established criteria. Allogeneic BM- or AT-MSCs were administered intradermally (1 x 10(6) cells) into partial-thickness wounds created on female animals, and covered with Vaseline® gauze or fibrin in a randomized pattern. Animals were euthanized at 7, 10, 14 and 21 days. Tissues were analyzed visually for healing and by microscopic examination for epidermal development and remodelling. Polymerase chain reaction (PCR) was used to detect the presence of male DNA in the specimens. All wounds were healed by 14 days. MSC-injected wounds were associated with improved appearance and faster re-epithelialization compared to saline controls. Evaluation of rete ridge depth and architecture showed that MSC treatment promoted a faster rate of epidermal maturation. Male DNA was detected in all samples at days 7 and 10, suggesting the presence of MSCs. We showed the safety, feasibility and potential efficacy of local injection of allogeneic BM- and AT-MSCs for treatment of wounds in a preclinical model. Our data in this large animal model support the potential use of BM- and AT-MSC for treatment of cutaneous wounds through modulation of healing and epithelialization. PMID:23418160

  19. Xenotransplantation of Human Cardiomyocyte Progenitor Cells Does Not Improve Cardiac Function in a Porcine Model of Chronic Ischemic Heart Failure. Results from a Randomized, Blinded, Placebo Controlled Trial

    PubMed Central

    Jansen of Lorkeers, Sanne J.; Gho, Johannes M. I. H.; Koudstaal, Stefan; van Hout, Gerardus P. J.; Zwetsloot, Peter Paul M.; van Oorschot, Joep W. M.; van Eeuwijk, Esther C. M.; Leiner, Tim; Hoefer, Imo E.; Goumans, Marie-José; Doevendans, Pieter A.; Sluijter, Joost P. G.; Chamuleau, Steven A. J.

    2015-01-01

    Background Recently cardiomyocyte progenitor cells (CMPCs) were successfully isolated from fetal and adult human hearts. Direct intramyocardial injection of human CMPCs (hCMPCs) in experimental mouse models of acute myocardial infarction significantly improved cardiac function compared to controls. Aim Here, our aim was to investigate whether xenotransplantation via intracoronary infusion of fetal hCMPCs in a pig model of chronic myocardial infarction is safe and efficacious, in view of translation purposes. Methods & Results We performed a randomized, blinded, placebo controlled trial. Four weeks after ischemia/reperfusion injury by 90 minutes of percutaneous left anterior descending artery occlusion, pigs (n = 16, 68.5 ± 5.4 kg) received intracoronary infusion of 10 million fetal hCMPCs or placebo. All animals were immunosuppressed by cyclosporin (CsA). Four weeks after infusion, endpoint analysis by MRI displayed no difference in left ventricular ejection fraction, left ventricular end diastolic and left ventricular end systolic volumes between both groups. Serial pressure volume (PV-)loop and echocardiography showed no differences in functional parameters between groups at any timepoint. Infarct size at follow-up, measured by late gadolinium enhancement MRI showed no difference between groups. Intracoronary pressure and flow measurements showed no signs of coronary obstruction 30 minutes after cell infusion. No premature death occurred in cell treated animals. Conclusion Xenotransplantation via intracoronary infusion of hCMPCs is feasible and safe, but not associated with improved left ventricular performance and infarct size compared to placebo in a porcine model of chronic myocardial infarction. PMID:26678993

  20. Effect of Carbohydrate Composition in Barley and Oat Cultivars on Microbial Ecophysiology and Proliferation of Salmonella enterica in an In Vitro Model of the Porcine Gastrointestinal Tract▿ †

    PubMed Central

    Pieper, Robert; Bindelle, Jérôme; Rossnagel, Brian; Van Kessel, Andrew; Leterme, Pascal

    2009-01-01

    The influence of the carbohydrate (CHO) composition of cereal cultivars on microbial ecophysiology was studied using an in vitro model of the porcine gastrointestinal tract. Ten hull-less barley cultivars, six barley cultivars with hulls, six oat cultivars, and six oat groats that differed in β-glucan, nonstarch polysaccharide (NSP), and starch contents and starch type were hydrolyzed enzymatically and incubated for 72 h with pig feces. Fermentation kinetics were modeled, and microbial compositions and short-chain fatty acid (SCFA) profiles were analyzed using terminal restriction fragment length polymorphism and gas chromatography. Cluster analysis and canonical ordination revealed different effects on fermentation and microbial ecology depending on the type of CHO and cultivar. First, in cultivars of barley with hulls and oats, the cellulose and insoluble NSP contents (i) increased Ruminococcus flavefaciens-like and Clostridium xylanolyticum-like phylotypes, (ii) increased acetate production, and (iii) decreased fermentation activity. Second, in hull-less barley cultivars the β-glucan, amylose, amylopectin, crude protein, and soluble NSP contents determined the microbial community composition and activity as follows: (i) the amylose contents of the hull-less barley varieties increased the butyrate production and the abundance of Clostridium butyricum-like phylotypes, (ii) the β-glucan content determined the total amounts of SCFA, and (iii) the amylopectin and starch contents affected the abundance of Clostridium ramosum-like phylotypes, members of Clostridium cluster XIVa, and Bacteroides-like bacteria. Finally, the effect of CHO on proliferation of Salmonella enterica in the model was determined. Salmonella cell counts were not affected, but the relative proportion of Salmonella decreased with hull-less barley cultivars and increased with oat cultivars as revealed by quantitative PCR. Our results shed light on the complex interactions of cereal CHO with

  1. Admittance‐based pressure–volume loops versus gold standard cardiac magnetic resonance imaging in a porcine model of myocardial infarction

    PubMed Central

    van Hout, Gerardus P. J.; Jansen, Sanne J.; Gho, Johannes M. I. H.; Doevendans, Pieter A.; van Solinge, Wouter W.; Pasterkamp, Gerard; Chamuleau, Steven A. J.; Hoefer, Imo E.

    2014-01-01

    Abstract A novel admittance‐based pressure–volume system (AS) has recently been developed and introduced. Thus far, the new technique has been validated predominantly in small animals. In large animals it has only been compared to three‐dimensional echocardiography (3DE) where the AS showed to overestimate left ventricular (LV) volumes. To fully determine the accuracy of this device, we compared the AS with gold standard cardiac magnetic resonance imaging (CMRI) in a porcine model of chronic myocardial infarction (MI). Fourteen pigs were subjected to 90 min closed chest balloon occlusion of the left anterior descending artery. After 8 weeks of follow up, pigs were consecutively subjected to LV volume measurements by the AS, CMRI, and 3DE under general anesthesia. The AS overestimated end diastolic volume (EDV; +20.9 ± 30.6 mL, P = 0.024) and end systolic volume (ESV; +17.7 ± 29.4 mL, P = 0.042) but not ejection fraction (EF; +2.46 ± 6.16%, P = NS) compared to CMRI. Good correlations of EDV (R = 0.626, P = 0.017) and EF (R = 0.704, P = 0.005) between the AS and CMRI were observed. EF measured by the AS and 3DE also correlated significantly (R = 0.624, P = 0.030). After subjection of pigs to MI, the AS very moderately overestimates LV volumes and shows accurate measurements for EF compared to CMRI. This makes the AS a useful tool to determine cardiac function and dynamic changes in large animal models of cardiac disease. PMID:24771693

  2. Computational model for monitoring cholesterol metabolism.

    PubMed

    Selvakumar, R; Rashith Muhammad, M; Poornima Devi, G

    2014-12-01

    A non-deterministic finite automaton is designed to observe the cholesterol metabolism with the states of acceptance and rejection. The acceptance state of the automaton depicts the normal level of metabolism and production of good cholesterol as an end product. The rejection state of this machine shows the inhibition of enzymatic activity in cholesterol synthesis and removal of free fatty acids. The deficiency in human cholesterol metabolism pathway results in abnormal accumulation of cholesterol in plasma, arterial tissues leading to diseases such as hypercholesterolemia, atherosclerosis respectively and formation of gallstones. The designed machine can be used to monitor the cholesterol metabolism at molecular level through regulation of enzymes involved in the biosynthesis and metabolism of cholesterol for the treatment of diseases incident due to the respective metabolic disorder. In addition, an algorithm for this machine has been developed to compare the programmed string with the given string. This study demonstrates the construction of a machine that is used for the development of molecular targeted therapy for the disorders in cholesterol metabolism. PMID:26396654

  3. Tissue damage by laser radiation: an in vitro comparison between Tm:YAG and Ho:YAG laser on a porcine kidney model.

    PubMed

    Huusmann, Stephan; Wolters, Mathias; Kramer, Mario W; Bach, Thorsten; Teichmann, Heinrich-Otto; Eing, Andreas; Bardosi, Sebastian; Herrmann, Thomas R W

    2016-01-01

    The understanding of tissue damage by laser radiation is very important for the safety in the application of surgical lasers. The objective of this study is to evaluate cutting, vaporization and coagulation properties of the 2 µm Tm:YAG laser (LISA Laser Products OHG, GER) in comparison to the 2.1 µm Ho:YAG laser (Coherent Medical Group, USA) at different laser power settings in an in vitro model of freshly harvested porcine kidneys. Laser radiation of both laser generators was delivered by using a laser fiber with an optical core diameter of 550 µm (RigiFib, LISA Laser GER). Freshly harvested porcine kidneys were used as tissue model. Experiments were either performed in ambient air or in aqueous saline. The Tm:YAG laser was adjusted to 5 W for low and 120 W for the high power setting. The Ho:YAG laser was adjusted to 0.5 J and 10 Hz (5 W average power) for low power setting and to 2.0 J and 40 Hz (80 W average power) for high power setting, accordingly. The specimens of the cutting experiments were fixed in 4 % formalin, embedded in paraffin and stained with Toluidin blue. The laser damage zone was measured under microscope as the main evaluation criteria. Laser damage zone consists of an outer coagulation zone plus a further necrotic zone. In the ambient air experiments the laser damage zone for the low power setting was 745 ± 119 µm for the Tm:YAG and 614 ± 187 µm for the Ho:YAG laser. On the high power setting, the damage zone was 760 ± 167 µm for Tm:YAG and 715 ± 142 µm for Ho:YAG. The incision depth in ambient air on the low power setting was 346 ± 199 µm for Tm:YAG, 118 ± 119 µm for Ho:YAG. On the high power setting incision depth was 5083 ± 144 µm (Tm:YAG) and 1126 ± 383 µm (Ho:YAG) respectively. In the saline solution experiments, the laser damage zone was 550 ± 137 µm (Tm:YAG) versus 447 ± 65 µm (Ho:YAG), on the low power setting and 653 ± 137 µm (Tm:YAG) versus 677 ± 134 µm (Ho

  4. Statistical models for the control phase of clinical monitoring.

    PubMed

    Stevens, Richard J; Oke, Jason; Perera, Rafael

    2010-08-01

    The rise in the prevalence of chronic conditions means that these are now the leading causes of death and disability worldwide, accounting for almost 60% of all deaths and 43% of the global burden of disease. Management of chronic conditions requires both effective treatment and ongoing monitoring. Although costs related to monitoring are substantial, there is relatively little evidence on its effectiveness. Monitoring is inherently different to diagnosis in its use of regularly repeated tests, and increasing frequency can result in poorer rather than better statistical properties because of multiple testing in the presence of high variability. We present here a general framework for modelling the control phase of a monitoring programme, and for the estimation of quantities of potential clinical interest such as the ratio of false to true positive tests. We show how four recent clinical studies of monitoring cardiovascular disease, hypertension, diabetes and HIV infection can be thought as special cases of this framework; as well as using this framework to clarify the choice of estimation and calculation methods available. Noticeably, in each of the presented examples over-frequent monitoring appears to be a greater problem than under-frequent monitoring. We also present recalculations of results under alternative conditions, illustrating conceptual decisions about modelling the true or observed value of a clinical measure. PMID:20442195

  5. Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model

    PubMed Central

    Shi, Hong; Jiang, Sheng-Jun; Li, Bin; Fu, Deng-Ke; Xin, Pei; Wang, Yong-Guang

    2011-01-01

    AIM: To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model. METHODS: The Erbe Jet2 water-jet system allows a needleless, tissue-selective hydro-dissection with a pre-selected pressure. Using this system, wedge hepatic resection was performed through three natural routes (trans-anal, trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia. Entry into the peritoneal cavity was via a 15-mm incision using a hook knife. The targeted liver segment was marked by an APC probe, followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane. The exposed vascular and ductal structures were clipped with Endoclips. Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery. After the procedure, the incision site was left open, and the animal was euthanized followed by necropsy. RESULTS: Using the Erbe Jet2 water-jet system, trans-anal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance. Trans-umbilical attempt failed due to an unstable operating platform. The incision for peritoneal entry took 1 min, and about 2 h was spent on excision of the liver tissue. The intra-operative blood loss ranged from 100 to 250 mL. Microscopically, the hydro-dissections were relatively precise and gentle, preserving most vessels. CONCLUSION: The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES, which deserves further studies to shorten the dissection time. PMID:21412502

  6. Evaluation of feasibility, efficiency and safety of a pure NOTES gastrojejunal bypass with gastric outlet obstruction, in an in vivo porcine model

    PubMed Central

    Gonzalez, J.-M.; Bonin, E. A.; Vanbiervliet, G.; Garnier, E.; Berdah, S.; Matthes, K.; Barthet, M.

    2013-01-01

    Introduction: Natural orifice transluminal endoscopic surgery (NOTES) gastrojejunal anastomosis (GJA) is a less invasive surgery for bariatric procedures and gastric outlet obstruction. The aim of this study was to evaluate the feasibility, efficacy, and safety of a pure NOTES gastrojejunal bypass using an in vivo porcine model. Material and methods: A prospective study was performed on nine swine. A double-channel scope was used. The intervention steps were: (i) gastric incision; (ii) peritoneal access; (iii) jejunal loop selection and mobilization into the stomach; (iv) stoma creation within the gastric wall and incision; (v) anastomosis suture and pylorus closure using a T-tag prototype. The animals were assessed clinically for 3 weeks including the weight gain. The patency of the GJA was assessed at necropsy and a histological analysis was performed. Results: We successfully performed all the procedures with a mean (standard deviation [SD]) operative time of 108 (26) minutes. We used a mean of 5.55 (1.30) stitches. There were no intraprocedural adverse events. Five animals survived up till euthanasia at 3 weeks (65 %). These showed a significant difference in weight curves of a loss of 3.2 kg compared with gain of 5.2 kg in a control group. Four pigs died from anastomotic dehiscence complicated by peritonitis. Conclusion: Gastrojejunal bypass with a pure NOTES approach is feasible. This procedure is effective, resulting in a patent anastomosis and a significant weight loss. However, the anastomotic dehiscence is a major concern because of its mortality rate, and further studies including improvement of the suturing device and the technique are needed. PMID:26135510

  7. Porcine circovirus type 2 (PCV2) vaccination reduces PCV2 in a PCV2 and Salmonella enterica serovar Choleraesuis coinfection model.

    PubMed

    Takada-Iwao, A; Seki, M; Nakanishi, M; Souma, J; Okuda, S; Okuda, Y; Imai, Y; Sato, S

    2013-02-22

    We previously reported that prior porcine circovirus type 2 (PCV2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of Salmonella enterica serovar Choleraesuis in infected pigs. Here, we evaluated whether PCV2 vaccination is effective in reducing fecal shedding and tissue dissemination of S. Choleraesuis and improving clinical signs associated with PCV2 and S. Choleraesuis infection in 15 Cesarean-derived, colostrum-deprived pigs randomly assigned to 3 groups (n=5/group). The vaccinated and co-infected (VAC-COINF) group received 2 ml of a commercial PCV2 vaccine at age 3 weeks. The VAC-COINF and co-infected (COINF) groups were inoculated intranasally with PCV2 and S. Choleraesuis at 5 and 7 weeks of age, respectively. The CONTROL group pigs received a similar volume of PBS for sham-vaccination and sham-inoculation. PCV2 vaccination clearly reduced PCV2 DNA load in the serum and postmortem tissue samples and decreased PCV2 antigen levels in tissue samples of the VAC-COINF group. After S. Choleraesuis infection, the incidence of several clinical signs increased in the VAC-COINF group compared to that in the COINF group. The microscopic lung lesions and weight gain, fecal shedding and tissue dissemination of S. Choleraesuis except in the spleen were not significantly different in the VAC-COINF and COINF groups. Thus, PCV2 vaccination reduced PCV2 in the S. Choleraesuis and PCV2 coinfection model and the effects on S. Choleraesuis were minimal. PMID:23107657

  8. Comparative analysis of in situ versus ex situ perfusion on flow and microcirculation in kidney procurement: research on a porcine model

    PubMed Central

    2013-01-01

    Background The first crucial step in transplantation appears to be the effective rinsing of the graft during organ procurement. Even though there is strong suspicion that ex situ perfusion results in better rinsing of the graft, there is no proof for this hypothesis. The aim of this study was to analyse the differences of in situ and ex situ kidney perfusion in a porcine model. Methods Standardised multiorgan procurement was performed in 15 German landrace pigs. Perfusion was carried out using histidine–tryptophan–ketoglutarate solution (HTK) under the application of pressure. In one kidney, in situ perfusion via the aorta was carried out while the second kidney received ex situ perfusion via the renal artery (RA). Perfusate flow inside the aorta and the RA was recorded at different pressure steps. In order to visualise the effect on the microcirculation, different coloured microparticles (MPs; 10 μm) were administered via the aorta or RA. Subsequently, frozen sections of the explanted kidneys were analysed histologically and MPs were evaluated quantitatively. Results Ex situ kidney perfusion resulted in significantly improved flow rates (P<0.0001) compared with in situ perfusion. By applying ex situ perfusion it was even possible to attain physiological flow levels on the RA under the application of external pressure of 150 to 200 mmHg. The amount of MPs was able to highlight the positive impact of ex situ perfusion on microcirculation of the kidney graft (P<0.0001). Conclusions The use of MPs represents a valuable tool for quantitative investigation and illustration of kidney perfusion in experimental setups. Additional ex situ perfusion is able to improve the quality of kidney perfusion. PMID:23837545

  9. Latent porcine circovirus type 2-infected domestic pigs: A potential infection model for the effective development of vaccines against latent or chronic virus induced diseases.

    PubMed

    Sydler, Titus; Brägger, Stefanie; Handke, Martin; Hartnack, Sonja; Lewis, Fraser I; Sidler, Xaver; Brugnera, Enrico

    2016-02-17

    Until recently, knowledge of the pathogenicity of Circoviridae and Anelloviridae family members was limited. Our previous discoveries provided clues toward resolving this issue based on studies of the latent nature of porcine circovirus type 2 (PCV2) genotype group members. We developed a conventional pig infection model that indicated that weaners already harbored latent PCV2 infection in the thymus, which enabled the viruses to specifically modulate the maturation of T-helper cells. This finding raised the possibility that the thymi of normal fetuses were already infected with PCV2. The present findings further substantiate our hypothesis that PCV2 masquerades as the host by infecting fetuses before they acquire immune-competence. We provide the first demonstration that all domestic pig fetuses preferentially harbor latent PCV2-infected cells in their thymi. These PCV2-infected cells are different from thymocytes and are located in the medulla of the fetal thymus. These latent PCV2-infected cells in fetuses are found at the same location and share characteristics with the infected cells observed in adolescent pigs. Moreover, fetuses also harbor these infected cells in other lymph system organs. We provide the first demonstration that the fetal thymus virus pools are minimally affected by sow vaccination, highlighting the immune-privileged character of this organ. Furthermore, we found a striking reduction in virus-infected cells in the fetal spleen and an increase in PCV2-infected cells in the fetal intestine of anti-PCV2-vaccinated mothers. These data indicate that specific immune response interactions occur between mothers and their progeny that are not dependent on the humoral immunity of the mother and cannot be attributed to the rudimentary humoral responses of the fetuses because these pig fetuses do not have any PCV2-specific antibodies. These shifts in our understanding of the PCV2-infected cell pool will lead to different avenues in the search for

  10. Autogenous bone marrow stromal cell sheets-loaded mPCL/TCP scaffolds induced osteogenesis in a porcine model of spinal interbody fusion.

    PubMed

    Abbah, Sunny A; Lam, Christopher X F; Ramruttun, Kumarsing A; Goh, James C H; Wong, Hee-Kit

    2011-03-01

    This study was designed to investigate whether a tissue-engineered construct composed of autogenous cell sheets and a polycaprolactone-based bioresorbable scaffold would enhance bone regeneration and spinal interbody fusion in a large animal model. Porcine-derived autogenous bone marrow stromal cells (BMSCs) cultured into multilayered cell sheets were induced into osteogenic differentiation with dexamethasone, l-ascorbic acid, and β-glycerol phosphate. These cell sheets were assembled with bioresorbable scaffolds made from medical-grade poly(epsilon-caprolactone) incorporating 20% β-tricalcium phosphate (mPCL/TCP) as tissue-engineered BMSC constructs. L2/3, L4/5 discectomies and decortication of the vertebral end plates were performed on 16 SPF Yorkshire pigs through an anterolateral approach. The tissue-engineered BMSC constructs were transplanted into the prepared intervertebral disc spaces of half of the pigs (n = 8), whereas cell-free mPCL/TCP served as controls in the remaining pigs. New bone formation and spinal fusion were evaluated at 3 and 6 months using microcomputed tomography, histology, fluorochrome bone labeling, and biomechanical testing. New bone formation was evident as early as 3 months in the BMSC group. At 6 months, bony fusion was observed in >60% (5/8) of segments in the BMSC group. None of the control animals with cell-free scaffold showed fusion at both time points. Biomechanical evaluation further revealed a significantly increased segmental stability in the BMSC group compared with the cell-free group at 6 months postimplantation (p < 0.01). These findings suggest that mPCL/TCP scaffolds loaded with in vitro differentiated autogenous BMSC sheets could induce bone formation and interbody fusion. This in turn resulted in enhanced segmental stability of the lumbar spine. PMID:20973747

  11. Prospective randomized comparison of endoscopic submucosal tunnel dissection and conventional submucosal dissection in the resection of superficial esophageal/gastric lesions in a living porcine model

    PubMed Central

    Gomercic, Cécile; Vanbiervliet, Geoffroy; Gonzalez, Jean-Michel; Saint-Paul, Marie-Christine; Garcès-Duran, Rodrigo; Garnier, Emmanuelle; Hébuterne, Xavier; Berdah, Stéphane; Barthet, Marc

    2015-01-01

    Background and study aims: To assess experimentally endoscopic submucosal tunnel dissection (ESTD) as an alternative technique of endoscopic submucosal resection. Patients and methods: This was a prospective, randomized, comparative experimental animal study carried out over a period of 9 months at the surgical research and teaching center of Aix-Marseille University, France. Virtual esophageal and gastric lesions measuring 3 cm in diameter were resected in pigs weighing 25 to 30 kg. The primary aim was to evaluate ESTD’s efficacy compared with endoscopic submucosal dissection (ESD). The secondary aims were to determine complication rates as well as to assess procedure time and procedure speed, histologic quality of the resected specimen, and procedure cost. Results: Eighteen procedures (9 ESD and 9 ESTD) were performed in nine pigs. The technical success rate was 88.9 % for both techniques, with one single failure in each. The en bloc resection rate was 100 % for ESTD and 88.9 % for ESD (one failure). The complication rate (22 %) and median procedure time were similar but dissection speed was quicker with ESTD in the esophagus (P = 0.03). Median procedure cost (728 Euros for ESD and ESTD) did not differ. On histologic examination, the lateral margins were healthy in 100 % of ESTD and in 88.9 % of ESD (P = 0.49). Deep resection margins were of better quality in ESTD (median submucosal thickness: 1307.1 µm vs. 884.7 µm; P = 0.039). Conclusions: ESTD is feasible and safe but not superior in the treatment of superficial esophageal/gastric lesions in porcine models compared with ESD. Nevertheless it provides a better quality histologic specimen. PMID:26716116

  12. ATMOSPHERIC DEPOSITION MODELING AND MONITORING OF NUTRIENTS

    EPA Science Inventory

    This talk presents an overview of the capabilities and roles that regional atmospheric deposition models can play with respect to multi-media environmental problems. The focus is on nutrient deposition (nitrogen). Atmospheric deposition of nitrogen is an important contributor to...

  13. Porcine prion protein amyloid

    PubMed Central

    Hammarström, Per; Nyström, Sofie

    2015-01-01

    ABSTRACT 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. PMID:26218890

  14. Simulation of between-farm transmission of porcine reproductive and respiratory syndrome virus in Ontario, Canada using the North American Animal Disease Spread Model.

    PubMed

    Thakur, Krishna K; Revie, Crawford W; Hurnik, Daniel; Poljak, Zvonimir; Sanchez, Javier

    2015-03-01

    Porcine reproductive and respiratory syndrome (PRRS), a viral disease of swine, has major economic impacts on the swine industry. The North American Animal Disease Spread Model (NAADSM) is a spatial, stochastic, farm level state-transition modeling framework originally developed to simulate highly contagious and foreign livestock diseases. The objectives of this study were to develop a model to simulate between-farm spread of a homologous strain of PRRS virus in Ontario swine farms via direct (animal movement) and indirect (sharing of trucks between farms) contacts using the NAADSM and to compare the patterns and extent of outbreak under different simulated conditions. A total of 2552 swine farms in Ontario province were allocated to each census division of Ontario and geo-locations of the farms were randomly generated within the agriculture land of each Census Division. Contact rates among different production types were obtained using pig movement information from four regions in Canada. A total of 24 scenarios were developed involving various direct (movement of infected animals) and indirect (pig transportation trucks) contact parameters in combination with alternating the production type of the farm in which the infection was seeded. Outbreaks were simulated for one year with 1000 replications. The median number of farms infected, proportion of farms with multiple outbreaks and time to reach the peak epidemic were used to compare the size, progression and extent of outbreaks. Scenarios involving spread only by direct contact between farms resulted in outbreaks where the median percentage of infected farms ranged from 31.5 to 37% of all farms. In scenarios with both direct and indirect contact, the median percentage of infected farms increased to a range from 41.6 to 48.6%. Furthermore, scenarios with both direct and indirect contact resulted in a 44% increase in median epidemic size when compared to the direct contact scenarios. Incorporation of both animal

  15. Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

    NASA Technical Reports Server (NTRS)

    Ramirez, W. Fred; Skliar, Mikhail; Narayan, Anand; Morgenthaler, George W.; Smith, Gerald J.

    1996-01-01

    Progress and results in the development of an integrated air quality modeling, monitoring, fault detection, and isolation system are presented. The focus was on development of distributed models of the air contaminants transport, the study of air quality monitoring techniques based on the model of transport process and on-line contaminant concentration measurements, and sensor placement. Different approaches to the modeling of spacecraft air contamination are discussed, and a three-dimensional distributed parameter air contaminant dispersion model applicable to both laminar and turbulent transport is proposed. A two-dimensional approximation of a full scale transport model is also proposed based on the spatial averaging of the three dimensional model over the least important space coordinate. A computer implementation of the transport model is considered and a detailed development of two- and three-dimensional models illustrated by contaminant transport simulation results is presented. The use of a well established Kalman filtering approach is suggested as a method for generating on-line contaminant concentration estimates based on both real time measurements and the model of contaminant transport process. It is shown that high computational requirements of the traditional Kalman filter can render difficult its real-time implementation for high-dimensional transport model and a novel implicit Kalman filtering algorithm is proposed which is shown to lead to an order of magnitude faster computer implementation in the case of air quality monitoring.

  16. Ischemic Postconditioning and Nitric Oxide Administration Failed to Confer Protective Effects in a Porcine Model of Extracorporeal Cardiopulmonary Resuscitation.

    PubMed

    Psotova, Hana; Ostadal, Petr; Mlcek, Mikulas; Kruger, Andreas; Janotka, Marek; Vondrakova, Dagmar; Svoboda, Tomas; Hrachovina, Matej; Taborsky, Ludek; Dudkova, Vlasta; Strunina, Svitlana; Kittnar, Otomar; Neuzil, Petr

    2016-04-01

    The protective effects of ischemic postconditioning (IPC) and nitric oxide (NO) administration have been demonstrated in several ischemic scenarios. However, current evidence regarding the effect of IPC and NO in extracorporeal cardiopulmonary resuscitation remains lacking. Fifteen female swine (body weight 45 kg) underwent veno-arterial extracorporeal membrane oxygenation (ECMO) implantation; cardiac arrest-ventricular fibrillation was induced by rapid ventricular pacing. After 20 min of cardiac arrest, blood flow was restored by increasing the ECMO flow rate to 4.5 L/min. The animals (five per group) were then randomly assigned to receive IPC (three cycles of 3 min ischemia and reperfusion), NO (80 ppm via oxygenator), or mild hypothermia (HT; 33.0°C). Cerebral oximetry and aortic blood pressure were monitored continuously. After 90 min of reperfusion, blood samples were drawn for the measurement of troponin I, myoglobin, creatine-phosphokinase, alanine aminotransferase, neuron-specific enolase, cystatin C, and reactive oxygen metabolite (ROM) levels. Significantly higher blood pressure and cerebral oxygen saturation values were observed in the HT group compared with the IPC and NO groups (P < 0.05). The levels of troponin I, myoglobin, creatine phosphokinase, and alanine aminotransferase were significantly lower in the HT group (P < 0.05); levels of neuron-specific enolase, cystatin C, and ROM were not significantly different. IPC and NO were comparable in all monitored parameters. The results of the present study indicate that IPC and NO administration are not superior interventions to HT for the maintenance of blood pressure, cerebral oxygenation, organ protection, and suppression of oxidative stress following extracorporeal cardiopulmonary resuscitation. PMID:26412075

  17. Screening and Characterization of Spontaneous Porcine Congenital Heart Defects for Gene Identification and Models of Human Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Rodent models of human congenital birth defects have been instrumental for gene discovery and investigation of mechanisms of disease. However, these models are limited by their small size making practiced intervention or detailed anatomic evaluation difficult. Swine have similar anato...

  18. Multi-metric model-based structural health monitoring

    NASA Astrophysics Data System (ADS)

    Jo, Hongki; Spencer, B. F.

    2014-04-01

    ABSTRACT The inspection and maintenance of bridges of all types is critical to the public safety and often critical to the economy of a region. Recent advanced sensor technologies provide accurate and easy-to-deploy means for structural health monitoring and, if the critical locations are known a priori, can be monitored by direct measurements. However, for today's complex civil infrastructure, the critical locations are numerous and often difficult to identify. This paper presents an innovative framework for structural monitoring at arbitrary locations on the structure combining computational models and limited physical sensor information. The use of multi-metric measurements is advocated to improve the accuracy of the approach. A numerical example is provided to illustrate the proposed hybrid monitoring framework, particularly focusing on fatigue life assessment of steel structures.

  19. A hierarchical wireless sensor network model for structural monitoring system

    NASA Astrophysics Data System (ADS)

    Niu, Jianjun; Deng, Zhidong

    2007-12-01

    Based on the technology of wireless sensor networks, topology planning of a large building structural monitoring system is investigated in this paper. A three-level transmission power model and two constrained premise are built up to form a clustering hierarchy based routing model for low delay and high data rate demands. Aim to minimize total power consumption of the whole system, particle swarm optimization (PSO) algorithm is applied to optimize the power level of each nodes. This optimized topology approach is important to design a more permanent wireless sensor network for structural monitoring system in the initial stage.

  20. A global, real-time flood monitoring model

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2014-07-01

    Floods kill thousands of people and cause billions of dollars in damage each year, and many floods occur in areas of the world that lack resources for flood monitoring and forecasting systems. Wu et al. report on an experimental real-time global flood monitoring system that employs a widely used land surface model coupled with a hierarchical dominant river tracing-based runoff routing model and satellite-based precipitation data to provide streamflow and flood detection/estimation information over most of the globe every 3 hours.

  1. Can we properly model the neutron monitor count rate?

    NASA Astrophysics Data System (ADS)

    Gil, Agnieszka; Usoskin, Ilya G.; Kovaltsov, Gennady A.; Mishev, Alexander L.; Corti, Claudio; Bindi, Veronica

    2015-09-01

    Neutron monitors provide continuous measurements of secondary nucleonic particles produced in the atmosphere by the primary cosmic rays and form the main tool to study the heliospheric modulation of cosmic rays. In order to study cosmic rays using the world network of neutron monitor and needs to be able to model the neutron monitor count rate. Earlier it was difficult because of the poorly known yield function, which has been essentially revisited recently. We have presented a verification of the new yield function of the standard neutron monitor (NM) using a recently released data on the direct in situ measurements of the galactic cosmic rays energy spectrum during 2006-2009 (the period of the record high cosmic ray flux) by Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics spaceborne spectrometer, and on NM latitude surveys performed during the period of 1994-2007, including periods of high solar activity. We found a very good agreement between the measured count rates of sea level NMs and the modeled ones in very different conditions: from low to high solar activity and from polar to tropical regions. This implies that the count rate of a sea level neutron monitor can be properly modeled in all conditions, using the new yield function.

  2. Model-aware Monitoring of SOAs for Compliance

    NASA Astrophysics Data System (ADS)

    Holmes, Ta'id; Mulo, Emmanuel; Zdun, Uwe; Dustdar, Schahram

    Business processes today are supported by process-driven service oriented architectures. Due to the increasing importance of compliance of an organization with regulatory requirements and internal policies, there is a need for appropriate techniques to monitor organizational information systems as they execute business processes. Event-based monitoring of processes is one of the ways to provide runtime process-state information. This type of monitoring, however, has limitations mostly related to the type and amount of information available in events and process engines. We propose a novel approach - model-aware monitoring of business processes - to address these limitations. Emitted events contain unique identifiers of models that can be retrieved dynamically during runtime from a model-aware repository and service environment (MORSE). The size of the events is kept small and patterns of events that signify interesting occurrences are identified through complex event processing and are signaled to interesting components such as a business intelligence. To illustrate our approach we present an industry case study where we have applied this generic infrastructure for the compliance monitoring of business processes.

  3. Development of an ex vivo porcine lung model for studying growth, virulence, and signaling of Pseudomonas aeruginosa.

    PubMed

    Harrison, Freya; Muruli, Aneesha; Higgins, Steven; Diggle, Stephen P

    2014-08-01

    Research into chronic infection by bacterial pathogens, such as Pseudomonas aeruginosa, uses various in vitro and live host models. While these have increased our understanding of pathogen growth, virulence, and evolution, each model has certain limitations. In vitro models cannot recapitulate the complex spatial structure of host organs, while experiments on live hosts are limited in terms of sample size and infection duration for ethical reasons; live mammal models also require specialized facilities which are costly to run. To address this, we have developed an ex vivo pig lung (EVPL) model for quantifying Pseudomonas aeruginosa growth, quorum sensing (QS), virulence factor production, and tissue damage in an environment that mimics a chronically infected cystic fibrosis (CF) lung. In a first test of our model, we show that lasR mutants, which do not respond to 3-oxo-C(12)-homoserine lactone (HSL)-mediated QS, exhibit reduced virulence factor production in EVPL. We also show that lasR mutants grow as well as or better than a corresponding wild-type strain in EVPL. lasR mutants frequently and repeatedly arise during chronic CF lung infection, but the evolutionary forces governing their appearance and spread are not clear. Our data are not consistent with the hypothesis that lasR mutants act as social "cheats" in the lung; rather, our results support the hypothesis that lasR mutants are more adapted to the lung environment. More generally, this model will facilitate improved studies of microbial disease, especially studies of how cells of the same and different species interact in polymicrobial infections in a spatially structured environment. PMID:24866798

  4. Development of an Ex Vivo Porcine Lung Model for Studying Growth, Virulence, and Signaling of Pseudomonas aeruginosa

    PubMed Central

    Muruli, Aneesha; Higgins, Steven; Diggle, Stephen P.

    2014-01-01

    Research into chronic infection by bacterial pathogens, such as Pseudomonas aeruginosa, uses various in vitro and live host models. While these have increased our understanding of pathogen growth, virulence, and evolution, each model has certain limitations. In vitro models cannot recapitulate the complex spatial structure of host organs, while experiments on live hosts are limited in terms of sample size and infection duration for ethical reasons; live mammal models also require specialized facilities which are costly to run. To address this, we have developed an ex vivo pig lung (EVPL) model for quantifying Pseudomonas aeruginosa growth, quorum sensing (QS), virulence factor production, and tissue damage in an environment that mimics a chronically infected cystic fibrosis (CF) lung. In a first test of our model, we show that lasR mutants, which do not respond to 3-oxo-C12-homoserine lactone (HSL)-mediated QS, exhibit reduced virulence factor production in EVPL. We also show that lasR mutants grow as well as or better than a corresponding wild-type strain in EVPL. lasR mutants frequently and repeatedly arise during chronic CF lung infection, but the evolutionary forces governing their appearance and spread are not clear. Our data are not consistent with the hypothesis that lasR mutants act as social “cheats” in the lung; rather, our results support the hypothesis that lasR mutants are more adapted to the lung environment. More generally, this model will facilitate improved studies of microbial disease, especially studies of how cells of the same and different species interact in polymicrobial infections in a spatially structured environment. PMID:24866798

  5. Self-, other-, and joint monitoring using forward models

    PubMed Central

    Pickering, Martin J.; Garrod, Simon

    2014-01-01

    In the psychology of language, most accounts of self-monitoring assume that it is based on comprehension. Here we outline and develop the alternative account proposed by Pickering and Garrod (2013), in which speakers construct forward models of their upcoming utterances and compare them with the utterance as they produce them. We propose that speakers compute inverse models derived from the discrepancy (error) between the utterance and the predicted utterance and use that to modify their production command or (occasionally) begin anew. We then propose that comprehenders monitor other people’s speech by simulating their utterances using covert imitation and forward models, and then comparing those forward models with what they hear. They use the discrepancy to compute inverse models and modify their representation of the speaker’s production command, or realize that their representation is incorrect and may develop a new production command. We then discuss monitoring in dialogue, paying attention to sequential contributions, concurrent feedback, and the relationship between monitoring and alignment. PMID:24723869

  6. Model-based monitoring of stormwater runoff quality.

    PubMed

    Birch, Heidi; Vezzaro, Luca; Mikkelsen, Peter Steen

    2013-01-01

    Monitoring of micropollutants (MP) in stormwater is essential to evaluate the impacts of stormwater on the receiving aquatic environment. The aim of this study was to investigate how different strategies for monitoring of stormwater quality (combining a model with field sampling) affect the information obtained about MP discharged from the monitored system. A dynamic stormwater quality model was calibrated using MP data collected by automatic volume-proportional sampling and passive sampling in a storm drainage system on the outskirts of Copenhagen (Denmark) and a 10-year rain series was used to find annual average (AA) and maximum event mean concentrations. Use of this model reduced the uncertainty of predicted AA concentrations compared to a simple stochastic method based solely on data. The predicted AA concentration, obtained by using passive sampler measurements (1 month installation) for calibration of the model, resulted in the same predicted level but with narrower model prediction bounds than by using volume-proportional samples for calibration. This shows that passive sampling allows for a better exploitation of the resources allocated for stormwater quality monitoring. PMID:24037157

  7. Model Selection for Monitoring CO2 Plume during Sequestration

    SciTech Connect

    2014-12-31

    The model selection method developed as part of this project mainly includes four steps: (1) assessing the connectivity/dynamic characteristics of a large prior ensemble of models, (2) model clustering using multidimensional scaling coupled with k-mean clustering, (3) model selection using the Bayes' rule in the reduced model space, (4) model expansion using iterative resampling of the posterior models. The fourth step expresses one of the advantages of the method: it provides a built-in means of quantifying the uncertainty in predictions made with the selected models. In our application to plume monitoring, by expanding the posterior space of models, the final ensemble of representations of geological model can be used to assess the uncertainty in predicting the future displacement of the CO2 plume. The software implementation of this approach is attached here.

  8. Model Selection for Monitoring CO2 Plume during Sequestration

    Energy Science and Technology Software Center (ESTSC)

    2014-12-31

    The model selection method developed as part of this project mainly includes four steps: (1) assessing the connectivity/dynamic characteristics of a large prior ensemble of models, (2) model clustering using multidimensional scaling coupled with k-mean clustering, (3) model selection using the Bayes' rule in the reduced model space, (4) model expansion using iterative resampling of the posterior models. The fourth step expresses one of the advantages of the method: it provides a built-in means ofmore » quantifying the uncertainty in predictions made with the selected models. In our application to plume monitoring, by expanding the posterior space of models, the final ensemble of representations of geological model can be used to assess the uncertainty in predicting the future displacement of the CO2 plume. The software implementation of this approach is attached here.« less

  9. Monitoring and modeling human interactions with ecosystems

    NASA Astrophysics Data System (ADS)

    Milesi, Cristina

    With rapidly increasing consumption rates and global population, there is a growing interest in understanding how to balance human activities with the other components of the Earth system. Humans alter ecosystem functioning with land cover changes, greenhouse gas emissions and overexploitation of natural resources. On the other side, climate and its inherent interannual variability drive global Net Primary Productivity (NPP), the base of energy for all trophic levels, shaping humans' distribution on the land surface and their sensitivity to natural and accelerated patterns of variation in ecosystem processes. In this thesis, I analyzed anthropogenic influences on ecosystems and ecosystems impacts on humans through a multi-scale approach. Anthropogenic influences were analyzed with a special focus on urban ecosystems, the living environment of nearly half of the global population and almost 90% of the population in the industrialized countries. A poorly quantified aspect of urban ecosystems is the biogeochemistry of urban vegetation, intensively managed through fertilization and irrigation. In chapter 1, adapting the ecosystem model Biome-BGC, I simulated the growth of turf grasses across the United States, and estimated their potential impact on the continental water and carbon budget. Using a remote sensing-based approach, I also developed a methodology to estimate the impact of land cover changes due to urbanization on the regional photosynthetic capacity (chapter 2), finding that low-density urbanization can retain high levels of net primary productivity, although at the expense of inefficient sprawl. One of the feedbacks of urbanization is the urban heat island effect, which I analyzed in conjunction with a remote sensing based estimate of fractional impervious surface area, showing how this is related to increases in land surface temperatures, independently from geographic location and population density (chapter 3). Finally, in chapter 4, I described the

  10. 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

    PubMed Central

    2012-01-01

    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 modulations point to

  11. Model-free execution monitoring in behavior-based robotics.

    PubMed

    Pettersson, Ola; Karlsson, Lars; Saffiotti, Alessandro

    2007-08-01

    In the near future, autonomous mobile robots are expected to help humans by performing service tasks in many different areas, including personal assistance, transportation, cleaning, mining, or agriculture. In order to manage these tasks in a changing and partially unpredictable environment without the aid of humans, the robot must have the ability to plan its actions and to execute them robustly and safely. The robot must also have the ability to detect when the execution does not proceed as planned and to correctly identify the causes of the failure. An execution monitoring system allows the robot to detect and classify these failures. Most current approaches to execution monitoring in robotics are based on the idea of predicting the outcomes of the robot's actions by using some sort of predictive model and comparing the predicted outcomes with the observed ones. In contrary, this paper explores the use of model-free approaches to execution monitoring, that is, approaches that do not use predictive models. In this paper, we show that pattern recognition techniques can be applied to realize model-free execution monitoring by classifying observed behavioral patterns into normal or faulty execution. We investigate the use of several such techniques and verify their utility in a number of experiments involving the navigation of a mobile robot in indoor environments. PMID:17702287

  12. Model based condition monitoring in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Singh, Amardeep; Izadian, Afshin; Anwar, Sohel

    2014-12-01

    In this paper, a model based condition monitoring technique is developed for lithium-ion battery condition monitoring. Here a number of lithium-ion batteries are cycled using two separate over discharge test regimes and the resulting shift in battery parameters is recorded. The battery models are constructed using the equivalent circuit methodology. The condition monitoring setup consists of a model bank representing the different degree of parameter shift due to overdischarge in the lithium ion battery. Extended Kalman filters (EKF) are used to maintain increased robustness of the condition monitoring setup while estimating the terminal voltage of the battery cell. The information carrying residuals are generated and evaluation process is carried out in real-time using multiple model adaptive estimation (MMAE) methodology. The condition evaluation function is used to generate probabilities that indicate the presence of a particular operational condition. Using the test data, it is shown that the performance shift in lithium ion batteries due to over discharge can be accurately detected.

  13. A bio-inspired memory model for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; Zhu, Yong

    2009-04-01

    Long-term structural health monitoring (SHM) systems need intelligent management of the monitoring data. By analogy with the way the human brain processes memories, we present a bio-inspired memory model (BIMM) that does not require prior knowledge of the structure parameters. The model contains three time-domain areas: a sensory memory area, a short-term memory area and a long-term memory area. First, the initial parameters of the structural state are specified to establish safety criteria. Then the large amount of monitoring data that falls within the safety limits is filtered while the data outside the safety limits are captured instantly in the sensory memory area. Second, disturbance signals are distinguished from danger signals in the short-term memory area. Finally, the stable data of the structural balance state are preserved in the long-term memory area. A strategy for priority scheduling via fuzzy c-means for the proposed model is then introduced. An experiment on bridge tower deformation demonstrates that the proposed model can be applied for real-time acquisition, limited-space storage and intelligent mining of the monitoring data in a long-term SHM system.

  14. Fluid resuscitation guided by sublingual partial pressure of carbon dioxide during hemorrhagic shock in a porcine model.

    PubMed

    Xu, Jiefeng; Ma, Linhao; Sun, Shijie; Lu, Xiaoye; Wu, Xiaobo; Li, Zilong; Tang, Wanchun

    2013-04-01

    To avoid aggressive fluid resuscitation during hemorrhagic shock, fluid resuscitation is best guided by a specific measurement of tissue perfusion. We investigated whether fluid resuscitation guided by sublingual PCO2 would reduce the amount of resuscitation fluid without compromising the outcomes of hemorrhagic shock. Ten male domestic pigs weighing between 34 and 37 kg were used. Forty-five percent of estimated blood volume was removed during an interval of 1 h. The animals were then randomized to receive fluid resuscitation based on either sublingual PCO2 or blood pressure (BP). In the sublingual PCO2-guided group, resuscitation was initiated when sublingual PCO2 exceeded 70 Torr and stopped when it decreased to 50 Torr. In the BP-guided group, resuscitation was initiated when mean aortic pressure decreased to 60 mmHg and stopped when it increased to 90 mmHg. First, Ringer's lactate solution (RLS) of 30 mL kg was administered; subsequently, the shed blood was transfused if sublingual PCO2 remained greater than 50 Torr in the sublingual PCO2-guided group or mean aortic pressure was less than 90 mmHg in the BP-guided group. All the animals were monitored for 4 h and observed for an additional 68 h. In the sublingual PCO2-guided group, fluid resuscitation was required in only 40% of the animals. In addition, a significantly lower volume of RLS (170 ± 239 mL, P = 0.005 vs. BP-guided group) was administered without the need for blood infusion in this group. However, in the BP-guided group, all the animals required a significantly larger volume of fluid (955 ± 381 mL), including both RLS and blood. There were no differences in postresuscitation tissue microcirculation, myocardial and neurologic function, and 72-h survival between groups. During hemorrhagic shock, fluid resuscitation guided by sublingual PCO2 significantly reduced the amount of resuscitation fluid without compromising the outcomes of hemorrhagic shock. PMID:23364438

  15. Development of a Porcine Delayed Wound-Healing Model and Its Use in Testing a Novel Cell-Based Therapy

    SciTech Connect

    Hadad, Ivan; Johnstone, Brian H.; Brabham, Jeffrey G.; Blanton, Matthew W.; Rogers, Pamela I.; Fellers, Cory; Solomon, James L.; Merfeld-Clauss, Stephanie; DesRosiers, Colleen M.; Dynlacht, Joseph R.; Coleman, John J.; March, Keith L.

    2010-11-01

    Purpose: A delayed full-thickness wound-healing model was developed and used for examining the capacity of adipose-derived stem cells (ASCs), either alone or in platelet-rich fibrin gels, to promote healing. Methods and Materials: Four pigs received electron beam radiation to the dorsal skin surface. Five weeks after radiation, subcutaneous fat was harvested from nonirradiated areas and processed to yield ASCs. Two weeks later, 28 to 30 full-thickness 1.5-cm{sup 2} wounds were made in irradiated and nonirradiated skin. Wounds were treated with either saline solution, ASCs in saline solution, platelet-rich plasma (PRP) fibrin gel, ASCs in PRP, or non-autologous green fluorescence protein-labeled ASCs. Results: The single radiation dose produced a significant loss of dermal microvasculature density (75%) by 7 weeks. There was a significant difference in the rate of healing between irradiated and nonirradiated skin treated with saline solution. The ASCs in PRP-treated wounds exhibited a significant 11.2% improvement in wound healing compared with saline solution. Enhancement was dependent on the combination of ASCs and PRP, because neither ASCs nor PRP alone had an effect. Conclusions: We have created a model that simulates the clinically relevant late radiation effects of delayed wound healing. Using this model, we showed that a combination of ASCs and PRP improves the healing rates of perfusion-depleted tissues, possibly through enhancing local levels of growth factors.

  16. Pharmacokinetics of 1-methyl-L-tryptophan after single and repeated subcutaneous application in a porcine model

    PubMed Central

    Wirthgen, Elisa; Kanitz, Ellen; Tuchscherer, Margret; Tuchscherer, Armin; Domanska, Grazyna; Weitschies, Werner; Seidlitz, Anne; Scheuch, Eberhard; Otten, Winfried

    2015-01-01

    Increased activity of the tryptophan-metabolizing enzyme indoleamine 2,3-dioxygenase (IDO) is associated with immunological and neurological disorders, and inhibition of its enzyme activity could be a therapeutic approach for treatment of these disorders. The aim of the present study was to establish a large animal model to study the accumulation of the potential IDO inhibitor 1-methyltryptophan (1-MT) in blood and different organs of domestic pigs (Sus scrofa domestica). Because 1-MT has not been previously evaluated in pigs, the pharmacokinetics of a single subcutaneous 1-MT application was investigated. Based on this kinetic study, a profile for repeated 1-MT applications over a period of five days was simulated and tested. The results show that a single administration of 1-MT increases its concentrations in blood, with the maximum concentration being obtained at 12 h. Repeated daily injections of 1‑MT generated increasing plasma concentrations followed by a steady-state after two days. Twelve hours after the final application, accumulation of 1-MT was observed in the brain and other organs, with a substantial variability among various tissues. The concentrations of 1-MT measured in plasma and tissues were similar to, or even higher, than those of tryptophan. Our data indicate that repeated subcutaneous injections of 1-MT provide a suitable model for accumulation of 1-MT in plasma and tissues of domestic pigs. These findings provide a basis for further research on the immunoregulatory functions of IDO in a large animal model. PMID:26725587

  17. Pharmacokinetics of 1-methyl-L-tryptophan after single and repeated subcutaneous application in a porcine model.

    PubMed

    Wirthgen, Elisa; Kanitz, Ellen; Tuchscherer, Margret; Tuchscherer, Armin; Domanska, Grazyna; Weitschies, Werner; Seidlitz, Anne; Scheuch, Eberhard; Otten, Winfried

    2016-05-20

    Increased activity of the tryptophan-metabolizing enzyme indoleamine 2,3-dioxygenase (IDO) is associated with immunological and neurological disorders, and inhibition of its enzyme activity could be a therapeutic approach for treatment of these disorders. The aim of the present study was to establish a large animal model to study the accumulation of the potential IDO inhibitor 1-methyltryptophan (1-MT) in blood and different organs of domestic pigs (Sus scrofa domestica). Because 1-MT has not been previously evaluated in pigs, the pharmacokinetics of a single subcutaneous 1-MT application was investigated. Based on this kinetic study, a profile for repeated 1-MT applications over a period of five days was simulated and tested. The results show that a single administration of 1-MT increases its concentrations in blood, with the maximum concentration being obtained at 12 h. Repeated daily injections of 1‑MT generated increasing plasma concentrations followed by a steady-state after two days. Twelve hours after the final application, accumulation of 1-MT was observed in the brain and other organs, with a substantial variability among various tissues. The concentrations of 1-MT measured in plasma and tissues were similar to, or even higher, than those of tryptophan. Our data indicate that repeated subcutaneous injections of 1-MT provide a suitable model for accumulation of 1-MT in plasma and tissues of domestic pigs. These findings provide a basis for further research on the immunoregulatory functions of IDO in a large animal model. PMID:26725587

  18. Detection and Characterization of Porcine Endogenous Retrovirus in Porcine Plasma and Porcine Factor VIII

    PubMed Central

    Takefman, Daniel M.; Wong, Susan; Maudru, Thomas; Peden, Keith; Wilson, Carolyn A.

    2001-01-01

    The pig genome contains porcine endogenous retroviruses (PERVs) capable of infecting human cells. Detection of infectious retrovirus in porcine peripheral blood mononuclear cells and endothelial cells suggested to us that pig plasma is likely to contain PERV. Both PERV env sequences and viral reverse transcriptase (RT) activity were detected in all plasma samples isolated from four NIH minipigs. To detect infectious virus from plasma, we performed a culture assay using three cell lines of feline, swine, and human origin that had previously been shown to be permissive for PERV. Infectious virus was successfully cultured from all four NIH minipig plasmas on the swine cell line ST-IOWA. Using RT-PCR with env-specific primers, we could detect expression of PERV class C envelope in the supernatant of ST-IOWA cells that had been exposed to each pig plasma. We next examined a pig plasma derivative, Hyate:C (porcine factor VIII), and found evidence of PERV particles, since all six lots examined were positive for PERV RNA and RT activity. However, infectious virus could not be detected in clinical lots of Hyate:C, suggesting that the manufacturing process might reduce the load of infectious virus to levels below detectable limits of the assay. Detection of infectious virus in porcine plasma confirms and extends the previous findings that certain porcine cells express PERV when manipulated in vitro and clearly demonstrates that there are porcine cells that express infectious PERV constitutively in vivo. PMID:11312325

  19. Isolation, Culture and Identification of Porcine Skeletal Muscle Satellite Cells

    PubMed Central

    Li, Bo-jiang; Li, Ping-hua; Huang, Rui-hua; Sun, Wen-xing; Wang, Han; Li, Qi-fa; Chen, Jie; Wu, Wang-jun; Liu, Hong-lin

    2015-01-01

    The objective of this study was to establish the optimum protocol for the isolation and culture of porcine muscle satellite cells. Mononuclear muscle satellite cells are a kind of adult stem cell, which is located between the basal lamina and sarcolemma of muscle fibers and is the primary source of myogenic precursor cells in postnatal muscle. Muscle satellite cells are a useful model to investigate the mechanisms of muscle growth and development. Although the isolation and culture protocols of muscle satellite cells in some species (e.g. mouse) have been established successfully, the culture system for porcine muscle satellite cells is very limited. In this study, we optimized the isolation procedure of porcine muscle satellite cells and elaborated the isolation and culture process in detail. Furthermore, we characterized the porcine muscle satellite cells using the immunofluorecence. Our study provides a reference for the isolation of porcine muscle satellite cells and will be useful for studying the molecular mechanisms in these cells. PMID:26104526

  20. Gender and genetic differences in bladder smooth muscle PPAR mRNA in a porcine model of the metabolic syndrome.

    PubMed

    Mattern, Heather M; Lloyd, Pamela G; Sturek, Michael; Hardin, Christopher D

    2007-08-01

    The metabolic syndrome and diabetes are associated with bladder dysfunction in many people. Peroxisome proliferator-activated receptors (PPARs) may play a role in the effects of the metabolic syndrome on bladder smooth muscle (BSM). The purpose of this study was to determine if there are gender and genetic differences in PPAR levels in BSM. We measured PPAR levels using quantitative PCR in BSM from male Yucatan swine and male and female Ossabaw Island swine, which is a model for the metabolic syndrome. Male Ossabaw swine had 0.732 +/- 0.111 the amount of PPAR-alpha mRNA as male Yucatan swine (P < 0.05), suggesting a genetic difference in PPAR-alpha levels. This difference may possibly contribute to the incidence of metabolic syndrome in the Ossabaw model compared to the Yucatan model. PPAR-delta mRNA was 2-fold higher in male Ossabaw swine than in female Ossabaw swine, with no significant differences in PPAR-alpha levels. However, PPAR-gamma mRNA was 4.067 +/- 0.134 times higher in female Ossabaw swine than in their male counterparts (P < 0.001). Changing the percentage of calories derived from fat did not alter any PPAR mRNA levels. Thus, PPAR-delta and PPAR-gamma mRNA levels in male and female Ossabaw swine BSM are not only different, but may also result in gender differences in lipid metabolism in bladder smooth muscle. We conclude that PPAR profiles in BSM may contribute to the susceptibility of BSM to lipotoxicity in the metabolic syndrome. PMID:17318406

  1. Towards Comprehensive Variation Models for Designing Vehicle Monitoring Systems

    NASA Technical Reports Server (NTRS)

    McAdams, Daniel A.; Tumer, Irem Y.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    When designing vehicle vibration monitoring systems for aerospace devices, it is common to use well-established models of vibration features to determine whether failures or defects exist. Most of the algorithms used for failure detection rely on these models to detect significant changes in a flight environment. In actual practice, however, most vehicle vibration monitoring systems are corrupted by high rates of false alarms and missed detections. This crucial roadblock makes their implementation in real vehicles (e.g., helicopter transmissions and aircraft engines) difficult, making their operation costly and unreliable. Research conducted at the NASA Ames Research Center has determined that a major reason for the high rates of false alarms and missed detections is the numerous sources of statistical variations that are not taken into account in the modeling assumptions. In this paper, we address one such source of variations, namely, those caused during the design and manufacturing of rotating machinery components that make up aerospace systems. We present a novel way of modeling the vibration response by including design variations via probabilistic methods. Using such models, we develop a methodology to account for design and manufacturing variations, and explore the changes in the vibration response to determine its stochastic nature. We explore the potential of the methodology using a nonlinear cam-follower model, where the spring stiffness values are assumed to follow a normal distribution. The results demonstrate initial feasibility of the method, showing great promise in developing a general methodology for designing more accurate aerospace vehicle monitoring systems.

  2. Effect of Negative Pressure Therapy on the Inflammatory Response of the Intestinal Microenvironment in a Porcine Septic Model

    PubMed Central

    Norbury, Kenneth C.; Moyer, Mary Pat

    2015-01-01

    In a swine model of ischemia/reperfusion injury coupled with sepsis, we have previously shown attenuation of secondary organ injury and decreased mortality with negative pressure therapy (NPT). We hypothesized that NPT modulates the intestinal microenvironment by mediating the innate immune system. Sepsis was induced in 12 anesthetized female pigs. Group 1 (n = 6) was decompressed at 12 hrs after injury (T12) and treated with standard of care (SOC), and group 2 (n = 6) with NPT for up to T48. Immunoparalysis was evident as lymphocytopenia at T24 in both groups; however, survival was improved in the NPT group versus SOC (Odds ratio = 4.0). The SOC group showed significant reduction in lymphocyte numbers compared to NPT group by T48 (p < 0.05). The capacity of peritoneal fluid to stimulate a robust reactive oxygen species response in vitro was greater for the NPT group, peaking at T24 for both M1 (p = 0.0197) and M2 macrophages (p = 0.085). Plasma elicited little if any effect which was confirmed by microarray analysis. In this septic swine model NPT appeared to modulate the intestinal microenvironment, facilitating an early robust, yet transient, host defense mediated by M1 and M2 macrophages. NPT may help overcome immunoparalysis that occurs during inflammatory response to septic injury. PMID:26294849

  3. Evaluation of a dynamic in vitro model to simulate the porcine ileal digestion of diets differing in carbohydrate composition.

    PubMed

    Meunier, J P; Manzanilla, E G; Anguita, M; Denis, S; Pérez, J F; Gasa, J; Cardot, J-M; Garcia, F; Moll, X; Alric, M

    2008-05-01

    The aim of the study was to assess the ability of a dynamic in vitro model to determine the digestibility of OM, CP, and starch compared with a validated, static, in vitro method and in vivo ileal digestibility obtained from growing pigs fitted with a T-cannula. Five experimental diets with different carbohydrate types and level were assessed: a standard corn-based diet (ST) or the same diet with coarse ground corn (CC), 8% sugar beet pulp (BP), 10% wheat bran (WB), or 8% sugar beet pulp and 10% wheat bran (HF). In the in vivo experiment, diets CC and HF reduced (P = 0.015) ileal digestibility of OM compared with the ST diet. The inclusion of sugar beet pulp reduced (P = 0.049) ileal CP digestibility of the BP diet. This reduction was not statistically significant when sugar beet pulp was combined with the wheat bran in the HF diet. No differences were shown for in vivo starch digestibility among diets. With the static in vitro method, the OM disappearance was greater than that observed in the in vivo experiment. In this static method, the BP and HF diets reduced (P = 0.004 and < 0.001, respectively) the disappearance of the OM compared with the ST diet. The coarse grinding of corn did not alter OM digestibility but decreased (P = 0.005) the starch digestibility. The R(2) between the in vivo results and the static in vitro methods for OM and starch digestibility was 0.99 when the CC diet was not considered. The dynamic in vitro model yielded OM and CP digestibility coefficients comparable with those obtained in vivo for the ST and CC diets. However, the values were considerably affected by the incorporation of the fibrous ingredients. Diets BP, WB, and HF had decreased (P = 0.009, 0.058, and 0.004, respectively) OM digestibility compared with the ST diet. Protein digestibility was also decreased (P < 0.001, P = 0.019, and P = 0.003, respectively) with the BP, WB, and HF diets compared with the ST diet. However, digestibility was decreased to a greater extent in the

  4. The feasibility of imaging myocardial ischemic/reperfusion injury using 99mTc-labeled duramycin in a porcine model

    PubMed Central

    Wang, Lei; Wang, Feng; Fang, Wei; Johnson, Steven E.; Audi, Said; Zimmer, Michael; Holly, Thomas A; Lee, Daniel; Zhu, Bao; Zhu, Haibo; Zhao, Ming

    2015-01-01

    When pathologically externalized, phosphatidylethanolamine (PE) is a potential surrogate marker for detecting tissue injuries. 99mTc-labeled duramycin is a peptide-based imaging agent that binds PE with high affinity and specificity. The goal of the current study was to investigate the clearance kinetics of 99mTc-labeled duramycin in a large animal model (normal pigs) and to assess its uptake in the heart using a pig model of myocardial ischemia-reperfusion injury. Methods The clearance and distribution of intravenously injected 99mTc-duramycin were characterized in sham-operated animals (n = 5). In a closed chest model of myocardial ischemia, coronary occlusion was induced by balloon angioplasty (n = 9). 99mTc-duramycin (10-15 mCi) was injected intravenously at 1 hour after reperfusion. SPECT/CT was acquired at 1 and 3 hours after injection. Cardiac tissues were analyzed for changes associated with acute cellular injuries. Autoradiography and gamma counting was used to determine radioactivity uptake. For the remaining animals, 99mTc-tetrafosamin scan was performed on the second day to identify the infarct site. Results Intravenously injected 99mTc-duramycin cleared from circulation predominantly via the renal/urinary tract with an α-phase half-life of 3.6 ± 0.3 minutes and β-phase half-life of 179.9 ± 64.7 minutes. In control animals, the ratios between normal heart and lung were 1.76 ± 0.21, 1.66 ± 0.22, 1.50 ± 0.20 and 1.75 ± 0.31 at 0.5, 1, 2 and 3 hours post injection, respectively. The ratios between normal heart and liver were 0.88 ± 0.13, 0.80 ± 0.13, 0.82 ± 0.19 and 0.88 ± 0.14. In vivo visualization of focal radioactivity uptake in the ischemic heart was attainable as early as 30 min post injection. The in vivo ischemic-to-normal uptake ratios were 3.57 ± 0.74 and 3.69 ± 0.91 at 1 and 3 hours post injection, respectively. Ischemic-to-lung ratios were 4.89 ± 0.85 and 4.93 ± 0.57; and ischemic-to-liver ratios were 2.05 ± 0.30 to 3.23 ± 0

  5. Sustained release nitrite therapy results in myocardial protection in a porcine model of metabolic syndrome with peripheral vascular disease

    PubMed Central

    Bradley, Jessica M.; Islam, Kazi N.; Polhemus, David J.; Donnarumma, Erminia; Brewster, Luke P.; Tao, Ya-Xiong; Goodchild, Traci T.

    2015-01-01

    Metabolic syndrome (MetS) reduces endothelial nitric oxide (NO) bioavailability and exacerbates vascular dysfunction in patients with preexisting vascular diseases. Nitrite, a storage form of NO, can mediate vascular function during pathological conditions when endogenous NO is reduced. The aims of the present study were to characterize the effects of severe MetS and obesity on dyslipidemia, myocardial oxidative stress, and endothelial NO synthase (eNOS) regulation in the obese Ossabaw swine (OS) model and to examine the effects of a novel, sustained-release formulation of sodium nitrite (SR-nitrite) on coronary vascular reactivity and myocardial redox status in obese OS subjected to critical limb ischemia (CLI). After 6 mo of an atherogenic diet, obese OS displayed a MetS phenotype. Obese OS had decreased eNOS functionality and NO bioavailability. In addition, obese OS exhibited increased oxidative stress and a significant reduction in antioxidant enzymes. The efficacy of SR-nitrite therapy was examined in obese OS subjected to CLI. After 3 wk of treatment, SR-nitrite (80 mg·kg−1·day−1 bid po) increased myocardial nitrite levels and eNOS function. Treatment with SR-nitrite reduced myocardial oxidative stress while increasing myocardial antioxidant capacity. Ex vivo assessment of vascular reactivity of left anterior descending coronary artery segments demonstrated marked improvement in vasoreactivity to sodium nitroprusside but not to substance P and bradykinin in SR-nitrite-treated animals compared with placebo-treated animals. In conclusion, in a clinically relevant, large-animal model of MetS and CLI, treatment with SR-nitrite enhanced myocardial NO bioavailability, attenuated oxidative stress, and improved ex vivo coronary artery vasorelaxation. PMID:25957218

  6. Laparo- and thoracoscopic aortic aneurysm neck optimization and treatment of potential endoleaks type IA and II in a porcine model

    PubMed Central

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

    2015-01-01

    Background Endovascular repair of aortic aneurysms has a higher incidence of late complications, and open conversion (OC) associated with high mortality may be required. As alternatives to OCs, we propose minimal invasive laparo-/thoracoscopic approaches, either to control endoleaks after endovascular repair, or to convert non-endovascular treatable cases due to a hostile neck anatomy by inserting a peri-aortic PTFE collar before endovascular repair. Such interventions may reduce complications and the necessity for OCs in the future. Methods In twelve pigs, were 10 had infra-/juxtrarenal AAAs, externally placed collars/aneuwraps around the proximal AAA neck and just below the left subclavian artery and division of the aortic side branches were carried out laparo-and thoracoscopically. Results For the laparoscopic and thoracoscopic procedures respectively, mean operative time was 143 ± 41 min and 86 ± 51 min and a mean of 2.6 and 2.25 aortic side branches were ligated/divided. For both procedures, the last half in the series were carried out significantly faster (p < 0.05) indicating a learning curve. Blood loss was minimal and no procedure related complications were seen. Conclusion Using these minimal invasive endoscopic approaches, it seems feasible to externally band aneurysm necks and ligate aortic side branches in a pig model. These procedures could potentially be considered as alternatives to OCs in controlling endoleaks and in improving the safety of endovascular interventions. As endoscopic aortic surgery is challenging a learning curve is expected. Practicing the described procedures using this model, can be used as a learning tool prior to similar interventions on humans. PMID:26793311

  7. Hydrogeologic Modeling for Monitoring, Reporting and Verification of Geologic Sequestration

    NASA Astrophysics Data System (ADS)

    Kolian, M.; De Figueiredo, M.; Lisa, B.

    2011-12-01

    In December 2010, EPA finalized Subpart RR of the Greenhouse Gas (GHG) Reporting Program, which requires facilities that conduct geologic sequestration (GS) of carbon dioxide (CO2) to report GHG data to EPA annually. The GHG Reporting Program requires reporting of GHGs and other relevant information from certain source categories in the United States, and information obtained through Subpart RR will inform Agency decisions under the Clean Air Act related to the use of carbon dioxide capture and sequestration for mitigating GHGs. This paper examines hydrogeologic modeling necessities and opportunities in the context of Subpart RR. Under Subpart RR, facilities that conduct GS by injecting CO2 for long-term containment in subsurface geologic formations are required to develop and implement an EPA-approved site-specific monitoring, reporting, and verification (MRV) plan; and report basic information on CO2 received for injection, annual monitoring activities and the amount of CO2 geologically sequestered using a mass balance approach. The major components of the MRV plan include: identification of potential surface leakage pathways for CO2 and the likelihood, magnitude, and timing, of surface leakage of CO2 through these pathways; delineation of the monitoring areas; strategy for detecting and quantifying any surface leakage of CO2; and the strategy for establishing the expected baselines for monitoring CO2 surface leakage. Hydrogeologic modeling is an integral aspect of the design of an MRV plan. In order to prepare an adequate monitoring program that addresses site specific risks over the full life of the project the MRV plan must reflect the full spatial extent of the free phase CO2 over time. Facilities delineate the maximum area that the CO2 plume is predicted to cover and how monitoring can be phased in over this area. The Maximum Monitoring Area (MMA) includes the extent of the free phase CO2 plume over the lifetime of the project plus a buffer zone of one

  8. Comparison of human and porcine skin for characterization of sunscreens

    NASA Astrophysics Data System (ADS)

    Weigmann, Hans-Jürgen; Schanzer, Sabine; Patzelt, Alexa; Bahaban, Virginie; Durat, Fabienne; Sterry, Wolfram; Lademann, Jürgen

    2009-03-01

    The universal sun protection factor (USPF) characterizing sunscreen efficacy based on spectroscopically determined data, which were obtained using the tape stripping procedure. The USPF takes into account the complete ultraviolet (UV) spectral range in contrast to the classical sun protection factor (SPF). Until now, the USPF determination has been evaluated only in human skin. However, investigating new filters not yet licensed excludes in vivo investigation on human skin but requires the utilization of a suitable skin model. The penetration behavior and the protection efficacy of 10 commercial sunscreens characterized by USPF were investigated, comparing human and porcine skin. The penetration behavior found for typical UV filter substances is nearly identical for both skin types. The comparison of the USPF obtained for human and porcine skin results in a linear relation between both USPF values with a correlation factor R2=0.98. The results demonstrate the possibility for the use of porcine skin to determine the protection efficacy of sunscreens.

  9. Model-based condition monitoring for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Kim, Taesic; Wang, Yebin; Fang, Huazhen; Sahinoglu, Zafer; Wada, Toshihiro; Hara, Satoshi; Qiao, Wei

    2015-11-01

    Condition monitoring for batteries involves tracking changes in physical parameters and operational states such as state of health (SOH) and state of charge (SOC), and is fundamentally important for building high-performance and safety-critical battery systems. A model-based condition monitoring strategy is developed in this paper for Lithium-ion batteries on the basis of an electrical circuit model incorporating hysteresis effect. It systematically integrates 1) a fast upper-triangular and diagonal recursive least squares algorithm for parameter identification of the battery model, 2) a smooth variable structure filter for the SOC estimation, and 3) a recursive total least squares algorithm for estimating the maximum capacity, which indicates the SOH. The proposed solution enjoys advantages including high accuracy, low computational cost, and simple implementation, and therefore is suitable for deployment and use in real-time embedded battery management systems (BMSs). Simulations and experiments validate effectiveness of the proposed strategy.

  10. Pulmonary Artery Denervation Reduces Pulmonary Artery Pressure and Induces Histological Changes in an Acute Porcine Model of Pulmonary Hypertension

    PubMed Central

    Arnold, Nadine D.; Chang, William; Watson, Oliver; Swift, Andrew J.; Condliffe, Robin; Elliot, Charlie A.; Kiely, David G.; Suvarna, S. Kim; Gunn, Julian; Lawrie, Allan

    2015-01-01

    Background— Pulmonary arterial hypertension is a devastating disease with high morbidity and mortality and limited treatment options. Recent studies have shown that pulmonary artery denervation improves pulmonary hemodynamics in an experimental model and in an early clinical trial. We aimed to evaluate the nerve distribution around the pulmonary artery, to determine the effect of radiofrequency pulmonary artery denervation on acute pulmonary hypertension induced by vasoconstriction, and to demonstrate denervation of the pulmonary artery at a histological level. Methods and Results— Histological evaluation identified a circumferential distribution of nerves around the proximal pulmonary arteries. Nerves were smaller in diameter, greater in number, and located in closer proximity to the luminal aspect of the pulmonary arterial wall beyond the pulmonary artery bifurcation. To determine the effect of pulmonary arterial denervation acute pulmonary hypertension was induced in 8 pigs by intravenous infusion of thromboxane A2 analogue. Animals were assigned to either pulmonary artery denervation, using a prototype radiofrequency catheter and generator, or a sham procedure. Pulmonary artery denervation resulted in reduced mean pulmonary artery pressure and pulmonary vascular resistance and increased cardiac output. Ablation lesions on the luminal surface of the pulmonary artery were accompanied by histological and biochemical alteration in adventitial nerves and correlated with improved hemodynamic parameters. Conclusions— Pulmonary artery denervation offers the possibility of a new treatment option for patients with pulmonary arterial hypertension. Further work is required to determine the long-term efficacy and safety. PMID:26553697

  11. Porcine salivary analysis by 2-dimensional gel electrophoresis in 3 models of acute stress: A pilot study

    PubMed Central

    Fuentes-Rubio, María; Cerón, José J.; de Torre, Carlos; Escribano, Damián; Gutiérrez, Ana M.; Tecles, Fernando

    2014-01-01

    The purpose of this research was to study changes in the salivary proteome of healthy pigs in stressful situations to identify any potential new salivary biomarker of stress. Three groups of animals were subjected to 3 stress models: snaring restraint followed by simulated sampling of vena cava blood; brief transport by road; and restriction of movement in a digestibility cage. Saliva was obtained from each animal before and 15 and 30 min after the induction of stress. The samples from the animals that showed the greatest increase in salivary cortisol concentration were pooled and run on 2-dimensional gels. Coomassie Brilliant Blue R-250 was used for spot detection and mass spectrometry for spot identification. Statistical analyses showed that 2 proteins had significant differences in expression before and after the induction of stress. These proteins were identified as odorant-binding protein and fragments of albumin. Further studies will be necessary to confirm the value of using these proteins as salivary biomarkers of stress in pigs. PMID:24688174

  12. Cost of post-weaning multi-systemic wasting syndrome and porcine circovirus type-2 subclinical infection in England – An economic disease model

    PubMed Central

    Alarcon, Pablo; Rushton, Jonathan; Wieland, Barbara

    2013-01-01

    Post-weaning multi-systemic wasting syndrome (PMWS) is a multi-factorial disease with major economic implications for the pig industry worldwide. The present study aimed to assess the economic impact of PMWS and porcine circovirus type 2 (PCV2) subclinical infections (PCV2SI) for farrow-to-finish farms and to estimate the resulting cost to the English pig industry. A disease model was built to simulate the varying proportions of pigs in a batch that get infected with PCV2 and develop either PMWS, subclinical disease (reduce growth without evident clinical signs) or remain healthy (normal growth and no clinical signs), depending on the farm level PMWS severity. This PMWS severity measure accounted for the level of post-weaning mortality, PMWS morbidity and proportion of PCV2 infected pigs observed on farms. The model generated six outcomes: infected pigs with PMWS that die (PMWS-D); infected pigs with PMWS that recover (PMWS-R); subclinical pigs that die (Sub-D); subclinical pigs that reach slaughter age (Sub-S); healthy pigs sold (H-S); and pigs, infected or non-infected by PCV2, that die due to non-PCV2 related causes (nonPCV2-D). Enterprise and partial budget analyses were used to assess the deficit/profits and the extra costs/extra benefits of a change in disease status, respectively. Results from the economic analysis at pig level were combined with the disease model's estimates of the proportion of different pigs produced at different severity scores to assess the cost of PMWS and subclinical disease at farm level, and these were then extrapolated to estimate costs at national level. The net profit for a H-S pig was £19.2. The mean loss for a PMWS-D pig was £84.1 (90% CI: 79.6–89.1), £24.5 (90% CI: 15.1–35.4) for a PMWS-R pig, £82.3 (90% CI: 78.1–87.5) for a Sub-D pig, and £8.1 (90% CI: 2.18–15.1) for a Sub-S pig. At farm level, the greatest proportion of negative economic impact was attributed to PCV2 subclinical pigs. The economic impact for the

  13. 7 CFR 1230.611 - Porcine animal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Porcine animal. 1230.611 Section 1230.611 Agriculture... CONSUMER INFORMATION Procedures for the Conduct of Referendum Definitions § 1230.611 Porcine animal. The term Porcine animal means a swine, that is raised: (a) As a feeder pig, that is, a young pig sold...

  14. 7 CFR 1230.611 - Porcine animal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Porcine animal. 1230.611 Section 1230.611 Agriculture... CONSUMER INFORMATION Procedures for the Conduct of Referendum Definitions § 1230.611 Porcine animal. The term Porcine animal means a swine, that is raised: (a) As a feeder pig, that is, a young pig sold...

  15. 7 CFR 1230.611 - Porcine animal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Porcine animal. 1230.611 Section 1230.611 Agriculture... CONSUMER INFORMATION Procedures for the Conduct of Referendum Definitions § 1230.611 Porcine animal. The term Porcine animal means a swine, that is raised: (a) As a feeder pig, that is, a young pig sold...

  16. 7 CFR 1230.611 - Porcine animal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Porcine animal. 1230.611 Section 1230.611 Agriculture... CONSUMER INFORMATION Procedures for the Conduct of Referendum Definitions § 1230.611 Porcine animal. The term Porcine animal means a swine, that is raised: (a) As a feeder pig, that is, a young pig sold...

  17. 7 CFR 1230.611 - Porcine animal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Porcine animal. 1230.611 Section 1230.611 Agriculture... CONSUMER INFORMATION Procedures for the Conduct of Referendum Definitions § 1230.611 Porcine animal. The term Porcine animal means a swine, that is raised: (a) As a feeder pig, that is, a young pig sold...

  18. Treatment with the C5a receptor antagonist ADC-1004 reduces myocardial infarction in a porcine ischemia-reperfusion model

    PubMed Central

    2010-01-01

    Background Polymorphonuclear neutrophils, stimulated by the activated complement factor C5a, have been implicated in cardiac ischemia/reperfusion injury. ADC-1004 is a competitive C5a receptor antagonist that has been shown to inhibit complement related neutrophil activation. ADC-1004 shields the neutrophils from C5a activation before they enter the reperfused area, which could be a mechanistic advantage compared to previous C5a directed reperfusion therapies. We investigated if treatment with ADC-1004, according to a clinically applicable protocol, would reduce infarct size and microvascular obstruction in a large animal myocardial infarct model. Methods In anesthetized pigs (42-53 kg), a percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 minutes, followed by 4 hours of reperfusion. Twenty minutes after balloon inflation the pigs were randomized to an intravenous bolus administration of ADC-1004 (175 mg, n = 8) or saline (9 mg/ml, n = 8). Area at risk (AAR) was evaluated by ex vivo SPECT. Infarct size and microvascular obstruction were evaluated by ex vivo MRI. The observers were blinded to the treatment at randomization and analysis. Results ADC-1004 treatment reduced infarct size by 21% (ADC-1004: 58.3 ± 3.4 vs control: 74.1 ± 2.9%AAR, p = 0.007). Microvascular obstruction was similar between the groups (ADC-1004: 2.2 ± 1.2 vs control: 5.3 ± 2.5%AAR, p = 0.23). The mean plasma concentration of ADC-1004 was 83 ± 8 nM at sacrifice. There were no significant differences between the groups with respect to heart rate, mean arterial pressure, cardiac output and blood-gas data. Conclusions ADC-1004 treatment reduces myocardial ischemia-reperfusion injury and represents a novel treatment strategy of myocardial infarct with potential clinical applicability. PMID:20875134

  19. Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

    PubMed Central

    Schlimp, Christoph J.; Solomon, Cristina; Keibl, Claudia; Zipperle, Johannes; Nürnberger, Sylvia; Öhlinger, Wolfgang; Redl, Heinz; Schöchl, Herbert

    2014-01-01

    be time consuming. LEVEL OF EVIDENCE Prospective, randomized, therapeutic feasibility study in an animal model, level V. PMID:24747454

  20. Tube-Load Model Parameter Estimation for Monitoring Arterial Hemodynamics

    PubMed Central

    Zhang, Guanqun; Hahn, Jin-Oh; Mukkamala, Ramakrishna

    2011-01-01

    A useful model of the arterial system is the uniform, lossless tube with parametric load. This tube-load model is able to account for wave propagation and reflection (unlike lumped-parameter models such as the Windkessel) while being defined by only a few parameters (unlike comprehensive distributed-parameter models). As a result, the parameters may be readily estimated by accurate fitting of the model to available arterial pressure and flow waveforms so as to permit improved monitoring of arterial hemodynamics. In this paper, we review tube-load model parameter estimation techniques that have appeared in the literature for monitoring wave reflection, large artery compliance, pulse transit time, and central aortic pressure. We begin by motivating the use of the tube-load model for parameter estimation. We then describe the tube-load model, its assumptions and validity, and approaches for estimating its parameters. We next summarize the various techniques and their experimental results while highlighting their advantages over conventional techniques. We conclude the review by suggesting future research directions and describing potential applications. PMID:22053157

  1. Myocardial function after polarizing versus depolarizing cardiac arrest with blood cardioplegia in a porcine model of cardiopulmonary bypass†

    PubMed Central

    Aass, Terje; Stangeland, Lodve; Moen, Christian Arvei; Salminen, Pirjo-Riitta; Dahle, Geir Olav; Chambers, David J.; Markou, Thomais; Eliassen, Finn; Urban, Malte; Haaverstad, Rune; Matre, Knut; Grong, Ketil

    2016-01-01

    OBJECTIVES Potassium-based depolarizing St Thomas' Hospital cardioplegic solution No 2 administered as intermittent, oxygenated blood is considered as a gold standard for myocardial protection during cardiac surgery. However, the alternative concept of polarizing arrest may have beneficial protective effects. We hypothesize that polarized arrest with esmolol/adenosine/magnesium (St Thomas' Hospital Polarizing cardioplegic solution) in cold, intermittent oxygenated blood offers comparable myocardial protection in a clinically relevant animal model. METHODS Twenty anaesthetized young pigs, 42 ± 2 (standard deviation) kg on standardized tepid cardiopulmonary bypass (CPB) were randomized (10 per group) to depolarizing or polarizing cardiac arrest for 60 min with cardioplegia administered in the aortic root every 20 min as freshly mixed cold, intermittent, oxygenated blood. Global and local baseline and postoperative cardiac function 60, 120 and 180 min after myocardial reperfusion was evaluated with pressure–conductance catheter and strain by Tissue Doppler Imaging. Regional tissue blood flow, cleaved caspase-3 activity, GRK2 phosphorylation and mitochondrial function and ultrastructure were evaluated in myocardial tissue samples. RESULTS Left ventricular function and general haemodynamics did not differ between groups before CPB. Cardiac asystole was obtained and maintained during aortic cross-clamping. Compared with baseline, heart rate was increased and left ventricular end-systolic and end-diastolic pressures decreased in both groups after weaning. Cardiac index, systolic pressure and radial peak systolic strain did not differ between groups. Contractility, evaluated as dP/dtmax, gradually increased from 120 to 180 min after declamping in animals with polarizing cardioplegia and was significantly higher, 1871 ± 160 (standard error) mmHg/s, compared with standard potassium-based cardioplegic arrest, 1351 ± 70 mmHg/s, after 180 min of reperfusion (P = 0

  2. Using models for the optimization of hydrologic monitoring

    USGS Publications Warehouse

    Fienen, Michael N.; Hunt, Randall J.; Doherty, John E.; Reeves, Howard W.

    2011-01-01

    Hydrologists are often asked what kind of monitoring network can most effectively support science-based water-resources management decisions. Currently (2011), hydrologic monitoring locations often are selected by addressing observation gaps in the existing network or non-science issues such as site access. A model might then be calibrated to available data and applied to a prediction of interest (regardless of how well-suited that model is for the prediction). However, modeling tools are available that can inform which locations and types of data provide the most 'bang for the buck' for a specified prediction. Put another way, the hydrologist can determine which observation data most reduce the model uncertainty around a specified prediction. An advantage of such an approach is the maximization of limited monitoring resources because it focuses on the difference in prediction uncertainty with or without additional collection of field data. Data worth can be calculated either through the addition of new data or subtraction of existing information by reducing monitoring efforts (Beven, 1993). The latter generally is not widely requested as there is explicit recognition that the worth calculated is fundamentally dependent on the prediction specified. If a water manager needs a new prediction, the benefits of reducing the scope of a monitoring effort, based on an old prediction, may be erased by the loss of information important for the new prediction. This fact sheet focuses on the worth or value of new data collection by quantifying the reduction in prediction uncertainty achieved be adding a monitoring observation. This calculation of worth can be performed for multiple potential locations (and types) of observations, which then can be ranked for their effectiveness for reducing uncertainty around the specified prediction. This is implemented using a Bayesian approach with the PREDUNC utility in the parameter estimation software suite PEST (Doherty, 2010). The

  3. A truncated diphtheria toxin based recombinant porcine CTLA-4 fusion toxin.

    PubMed

    Peraino, Jaclyn Stromp; Schenk, Marian; Zhang, Huiping; Li, Guoying; Hermanrud, Christina E; Neville, David M; Sachs, David H; Huang, Christene A; Duran-Struuck, Raimon; Wang, Zhirui

    2013-05-31

    Targeted cell therapies are possible through the generation of recombinant fusion proteins that combine a toxin, such as diphtheria toxin (DT), with an antibody or other molecule that confers specificity. Upon binding of the fusion protein to the cell of interest, the diphtheria toxin is internalized which results in protein synthesis inhibition and subsequent cell death. We have recently expressed and purified the recombinant soluble porcine CTLA-4 both with and without N-glycosylation in yeast Pichia pastoris for in vivo use in our preclinical swine model. The glycosylated and non-N-glycosylated versions of this recombinant protein each bind to a porcine CD80 expressing B-cell lymphoma line (LCL13271) with equal affinity (K(D)=13 nM). In this study we have linked each of the glycosylated and non-N-glycosylated soluble porcine CTLA-4 proteins to the truncated diphtheria toxin DT390 through genetic engineering yielding three versions of the porcine CTLA-4 fusion toxins: 1) monovalent glycosylated soluble porcine CTLA-4 fusion toxin; 2) monovalent non-N-glycosylated soluble porcine CTLA-4 fusion toxin and 3) bivalent non-N-glycosylated soluble porcine CTLA-4 fusion toxin. Protein synthesis inhibition analysis demonstrated that while all three fusion toxins are capable of inhibiting protein synthesis in vitro, the non-N-glycosylated porcine CTLA-4 isoforms function most efficiently. Binding analysis using flow cytometry of the porcine CTLA-4 fusion toxins to LCL13271 cells also demonstrated that the non-N-glycosylated porcine CTLA-4 isoforms bind to these cells with higher affinity compared to the glycosylated fusion toxin. The monovalent non-N-glycosylated porcine CTLA-4 fusion toxin was tested in vivo. NSG (NOD/SCID IL-2 receptor γ(-)/(-)) mice were injected with porcine CD80(+) LCL13271 tumor cells. All animals succumbed to tumors and those treated with the monovalent non-N-glycosylated porcine CTLA-4 fusion toxin survived longer based on a symptomatic scoring

  4. Porcine Dentin Sialophosphoprotein

    PubMed Central

    Yamakoshi, Yasuo; Lu, Yuhe; Hu, Jan C.-C.; Kim, Jung-Wook; Iwata, Takanori; Kobayashi, Kazuyuki; Nagano, Takatoshi; Yamakoshi, Fumiko; Hu, Yuanyuan; Fukae, Makoto; Simmer, James P.

    2008-01-01

    Dentin sialophosphoprotein (DSPP) is critical for proper mineralization of tooth dentin, and mutations in DSPP cause inherited dentin defects. Dentin phosphoprotein (DPP) is the C-terminal cleavage product of DSPP that binds collagen and induces intrafibrillar mineralization. We isolated DPP from individual pigs and determined that its N-terminal and C-terminal domains are glycosylated and that DPP averages 155 phosphates per molecule. Porcine DPP is unstable at low pH and high temperatures, and complexing with collagen improves its stability. Surprisingly, we observed DPP size variations on SDS-PAGE for DPP isolated from individual pigs. These variations are not caused by differences in proteolytic processing or degrees of phosphorylation or glycosylation, but rather to allelic variations in Dspp. Characterization of the DPP coding region identified 4 allelic variants. Among the 4 alleles, 27 sequence variations were identified, including 16 length polymorphisms ranging from 3 to 63 nucleotides. None of the length variations shifted the reading frame, and all localized to the highly redundant region of the DPP code. The 4 alleles encode DPP domains having 551, 575, 589, or 594 amino acids and completely explain the DPP size variations. DPP length variations are polymorphic and are not associated with dentin defects. PMID:18359767

  5. Wind-driven desertification: Process modeling, remote monitoring, and forecasting

    NASA Astrophysics Data System (ADS)

    Okin, Gregory Stewart

    Arid and semiarid landscapes comprise nearly a third of the Earth's total land surface. These areas are coming under increasing land use pressures. Despite their low productivity these lands are not barren. Rather, they consist of fragile ecosystems vulnerable to anthropogenic disturbance. The purpose of this thesis is threefold: (I) to develop and test a process model of wind-driven desertification, (II) to evaluate next-generation process-relevant remote monitoring strategies for use in arid and semiarid regions, and (III) to identify elements for effective management of the world's drylands. In developing the process model of wind-driven desertification in arid and semiarid lands, field, remote sensing, and modeling observations from a degraded Mojave Desert shrubland are used. This model focuses on aeolian removal and transport of dust, sand, and litter as the primary mechanisms of degradation: killing plants by burial and abrasion, interrupting natural processes of nutrient accumulation, and allowing the loss of soil resources by abiotic transport. This model is tested in field sampling experiments at two sites and is extended by Fourier Transform and geostatistical analysis of high-resolution imagery from one site. Next, the use of hyperspectral remote sensing data is evaluated as a substantive input to dryland remote monitoring strategies. In particular, the efficacy of spectral mixture analysis (SMA) in discriminating vegetation and soil types and determining vegetation cover is investigated. The results indicate that hyperspectral data may be less useful than often thought in determining vegetation parameters. Its usefulness in determining soil parameters, however, may be leveraged by developing simple multispectral classification tools that can be used to monitor desertification. Finally, the elements required for effective monitoring and management of arid and semiarid lands are discussed. Several large-scale multi-site field experiments are proposed to

  6. Chiller condition monitoring using topological case-based modeling

    SciTech Connect

    Tsutsui, Hiroaki; Kamimura, Kazuyuki

    1996-11-01

    To increase energy efficiency and economy, commercial building projects now often utilize centralized, shared sources of heat such as district heating and cooling (DHC) systems. To maintain efficiency, precise monitoring and scheduling of maintenance for chillers and heat pumps is essential. Low-performance operation results in energy loss, while unnecessary maintenance is expensive and wasteful. Plant supervisors are responsible for scheduling and supervising maintenance. Modeling systems that assist in analyzing system deterioration are of great benefit for these tasks. Topological case-based modeling (TCBM) (Tsutsui et al. 1993; Tsutsui 1995) is an effective tool for chiller performance deterioration monitoring. This paper describes TCBM and its application to this task using recorded historical performance data.

  7. Assessment of Alternative Conceptual Models Using Reactive Transport Modeling with Monitoring Data

    NASA Astrophysics Data System (ADS)

    Dai, Z.; Price, V.; Heffner, D.; Hodges, R.; Temples, T.; Nicholson, T.

    2005-12-01

    Monitoring data proved very useful in evaluating alternative conceptual models, simulating contaminant transport behavior, and reducing uncertainty. A graded approach using three alternative conceptual site models was formulated to simulate a field case of tetrachloroethene (PCE) transport and biodegradation. These models ranged from simple to complex in their representation of subsurface heterogeneities. The simplest model was a single-layer homogeneous aquifer that employed an analytical reactive transport code, BIOCHLOR (Aziz et al., 1999). Due to over-simplification of the aquifer structure, this simulation could not reproduce the monitoring data. The second model consisted of a multi-layer conceptual model, in combination with numerical modules, MODFLOW and RT3D within GMS, to simulate flow and reactive transport. Although the simulation results from the second model were comparatively better than those from the simple model, they still did not adequately reproduce the monitoring well concentrations because the geological structures were still inadequately defined. Finally, a more realistic conceptual model was formulated that incorporated heterogeneities and geologic structures identified from well logs and seismic survey data using the Petra and PetraSeis software. This conceptual model included both a major channel and a younger channel that were detected in the PCE source area. In this model, these channels control the local ground-water flow direction and provide a preferential chemical transport pathway. Simulation results using this conceptual site model proved compatible with the monitoring concentration data. This study demonstrates that the bias and uncertainty from inadequate conceptual models are much larger than those introduced from an inadequate choice of model parameter values (Neuman and Wierenga, 2003; Meyer et al., 2004; Ye et al., 2004). This case study integrated conceptual and numerical models, based on interpreted local hydrogeologic and

  8. Mapping, Monitoring and Modeling Submersed Aquatic Vegetation Species and Communities

    NASA Astrophysics Data System (ADS)

    Hartis, Brett Michael

    Aquatic macrophyte communities are critically important habitat species in aquatic systems worldwide. None are more important than those found beneath the water's surface, commonly referred to as submersed aquatic vegetation (SAV). Although vital to such systems, many native submersed plants have shown near irreversible declines in recent decades as water quality impairment, habitat destruction, and encroachment by invasive species have increased. In the past, aquatic plant science has emphasized the restoration and protection of native species and the management of invasive species. Comparatively little emphasis has been directed toward adequately mapping and monitoring these resources to track their viability over time. Modeling the potential intrusion of certain invasive plant species has also been given little attention, likely because aquatic systems in general can be difficult to assess. In recent years, scientists and resource managers alike have begun paying more attention to mapping SAV communities and to address the spread of invasive species across various regions. This research attempts to provide new, cutting-edge techniques to improve SAV mapping and monitoring efforts in coastal regions, at both community and individual species levels, while also providing insights about the establishment potential of Hydrilla verticillata, a noxious, highly invasive submersed plant. Technological advances in satellite remote sensing, interpolation and spatial analysis in geographic information systems, and state-of-the-art climate envelope modeling techniques were used to further assess the dynamic nature of SAV on various scales. This work contributes to the growing science of mapping, monitoring, and modeling of SAV

  9. Monitors.

    ERIC Educational Resources Information Center

    Powell, David

    1984-01-01

    Provides guidelines for selecting a monitor to suit specific applications, explains the process by which graphics images are produced on a CRT monitor, and describes four types of flat-panel displays being used in the newest lap-sized portable computers. A comparison chart provides prices and specifications for over 80 monitors. (MBR)

  10. Self-calibrating models for dynamic monitoring and diagnosis

    NASA Technical Reports Server (NTRS)

    Kuipers, Benjamin

    1994-01-01

    The present goal in qualitative reasoning is to develop methods for automatically building qualitative and semiquantitative models of dynamic systems and to use them for monitoring and fault diagnosis. The qualitative approach to modeling provides a guarantee of coverage while our semiquantitative methods support convergence toward a numerical model as observations are accumulated. We have developed and applied methods for automatic creation of qualitative models, developed two methods for obtaining tractable results on problems that were previously intractable for qualitative simulation, and developed more powerful methods for learning semiquantitative models from observations and deriving semiquantitative predictions from them. With these advances, qualitative reasoning comes significantly closer to realizing its aims as a practical engineering method.

  11. An in-depth comparison of the porcine, murine and human inflammasomes; lessons from the porcine genome and transcriptome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emerging evidence suggests that swine are a scientifically acceptable intermediate species between rodents and humans to model immune function relevant to humans. The swine genome has recently been sequenced and several preliminary structural and functional analysis of the porcine immunome have been...

  12. Research Advancements in Porcine Derived Mesenchymal Stem Cells.

    PubMed

    Bharti, Dinesh; Shivakumar, Sharath Belame; Subbarao, Raghavendra Baregundi; Rho, Gyu-Jin

    2016-01-01

    In the present era of stem cell biology, various animals such as Mouse, Bovine, Rabbit and Porcine have been tested for the efficiency of their mesenchymal stem cells (MSCs before their actual use for stem cell based application in humans. Among them pigs have many similarities to humans in the form of organ size, physiology and their functioning, therefore they have been considered as a valuable model system for in vitro studies and preclinical assessments. Easy assessability, few ethical issues, successful MSC isolation from different origins like bone marrow, skin, umbilical cord blood, Wharton's jelly, endometrium, amniotic fluid and peripheral blood make porcine a good model for stem cell therapy. Porcine derived MSCs (pMSCs have shown greater in vitro differentiation and transdifferention potential towards mesenchymal lineages and specialized lineages such as cardiomyocytes, neurons, hepatocytes and pancreatic beta cells. Immunomodulatory and low immunogenic profiles as shown by autologous and heterologous MSCs proves them safe and appropriate models for xenotransplantation purposes. Furthermore, tissue engineered stem cell constructs can be of immense importance in relation to various osteochondral defects which are difficult to treat otherwise. Using pMSCs successful treatment of various disorders like Parkinson's disease, cardiac ischemia, hepatic failure, has been reported by many studies. Here, in this review we highlight current research findings in the area of porcine mesenchymal stem cells dealing with their isolation methods, differentiation ability, transplantation applications and their therapeutic potential towards various diseases. PMID:26201864

  13. Monitoring Network Design for Discriminating and Reducing Models in Bayesian Model Averaging Paradigm

    NASA Astrophysics Data System (ADS)

    Tsai, F. T.; Pham, H. V.

    2013-12-01

    Bayesian model averaging (BMA) is often adopted to quantify model prediction and uncertainty using multiple models generated from various sources of uncertainty. Due to the lack of data and knowledge, the number of models with non-dominant posterior model probabilities can be overwhelming. Conducting prediction and uncertainty analysis using a great deal of computationally intensive simulation models (e.g., groundwater models) can become intractable under the BMA framework. Moreover, prediction results using the BMA can be useless when prediction uncertainty is very high. This study implements a monitoring network design under the BMA framework to discriminate groundwater models and in turn reduce the number of models. The posterior model probabilities are re-evaluated by using BMA prediction as 'future observation data' and historical data. Given a design criterion of posterior model probability (e.g. 85%), the monitoring network design aims to find the optimal number and location of monitoring wells at existing wells for continuous observation. If using existing wells cannot achieve the design criterion, then exploration of new monitoring well location is necessary. Once the design criterion is met, other models will be discriminated from the best model. Between-model variance will be significantly reduced. We use the monitoring network design to discriminate 18 complex groundwater models that include the '1,200-foot', '1,500-foot', and '1,700-foot' sands in the Baton Rouge area, southeastern Louisiana. The sources of uncertainty that creates the groundwater models are from hydrostratigraphic architecture, fault permeability architecture, and boundary conditions. To speed up model calibration, we develop a parallel version of CMA-ES and implement it to SuperMike II cluster at Louisiana State University. Results show that in the model calibration period from 1975 to 2010, eleven models have posterior model probabilities ranging from 3.5% to 17.4%. The purpose of

  14. Hierarchical Bayesian spatial models for multispecies conservation planning and monitoring.

    PubMed

    Carroll, Carlos; Johnson, Devin S; Dunk, Jeffrey R; Zielinski, William J

    2010-12-01

    Biologists who develop and apply habitat models are often familiar with the statistical challenges posed by their data's spatial structure but are unsure of whether the use of complex spatial models will increase the utility of model results in planning. We compared the relative performance of nonspatial and hierarchical Bayesian spatial models for three vertebrate and invertebrate taxa of conservation concern (Church's sideband snails [Monadenia churchi], red tree voles [Arborimus longicaudus], and Pacific fishers [Martes pennanti pacifica]) that provide examples of a range of distributional extents and dispersal abilities. We used presence-absence data derived from regional monitoring programs to develop models with both landscape and site-level environmental covariates. We used Markov chain Monte Carlo algorithms and a conditional autoregressive or intrinsic conditional autoregressive model framework to fit spatial models. The fit of Bayesian spatial models was between 35 and 55% better than the fit of nonspatial analogue models. Bayesian spatial models outperformed analogous models developed with maximum entropy (Maxent) methods. Although the best spatial and nonspatial models included similar environmental variables, spatial models provided estimates of residual spatial effects that suggested how ecological processes might structure distribution patterns. Spatial models built from presence-absence data improved fit most for localized endemic species with ranges constrained by poorly known biogeographic factors and for widely distributed species suspected to be strongly affected by unmeasured environmental variables or population processes. By treating spatial effects as a variable of interest rather than a nuisance, hierarchical Bayesian spatial models, especially when they are based on a common broad-scale spatial lattice (here the national Forest Inventory and Analysis grid of 24 km(2) hexagons), can increase the relevance of habitat models to multispecies

  15. Sustained inflation and incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation in a large porcine model of acute respiratory distress syndrome

    PubMed Central

    Muellenbach, Ralf M; Kredel, Markus; Zollhoefer, Bernd; Wunder, Christian; Roewer, Norbert; Brederlau, Joerg

    2006-01-01

    Background To compare the effect of a sustained inflation followed by an incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation on oxygenation and hemodynamics in a large porcine model of early acute respiratory distress syndrome. Methods Severe lung injury (Ali) was induced in 18 healthy pigs (55.3 ± 3.9 kg, mean ± SD) by repeated saline lung lavage until PaO2 decreased to less than 60 mmHg. After a stabilisation period of 60 minutes, the animals were randomly assigned to two groups: Group 1 (Pressure controlled ventilation; PCV): FIO2 = 1.0, PEEP = 5 cmH2O, VT = 6 ml/kg, respiratory rate = 30/min, I:E = 1:1; group 2 (High-frequency oscillatory ventilation; HFOV): FIO2 = 1.0, Bias flow = 30 l/min, Amplitude = 60 cmH2O, Frequency = 6 Hz, I:E = 1:1. A sustained inflation (SI; 50 cmH2O for 60s) followed by an incremental mean airway pressure (mPaw) trial (steps of 3 cmH2O every 15 minutes) were performed in both groups until PaO2 no longer increased. This was regarded as full lung inflation. The mPaw was decreased by 3 cmH2O and the animals reached the end of the study protocol. Gas exchange and hemodynamic data were collected at each step. Results The SI led to a significant improvement of the PaO2/FiO2-Index (HFOV: 200 ± 100 vs. PCV: 58 ± 15 and TAli: 57 ± 12; p < 0.001) and PaCO2-reduction (HFOV: 42 ± 5 vs. PCV: 62 ± 13 and TAli: 55 ± 9; p < 0.001) during HFOV compared to lung injury and PCV. Augmentation of mPaw improved gas exchange and pulmonary shunt fraction in both groups, but at a significant lower mPaw in the HFOV treated animals. Cardiac output was continuously deteriorating during the recruitment manoeuvre in both study groups (HFOV: TAli: 6.1 ± 1 vs. T75: 3.4 ± 0.4; PCV: TAli: 6.7 ± 2.4 vs. T75: 4 ± 0.5; p < 0.001). Conclusion A sustained inflation followed by an incremental mean airway pressure trial in HFOV improved oxygenation at a lower mPaw than during conventional lung protective

  16. Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

    NASA Technical Reports Server (NTRS)

    Ramirez, W. Fred; Skliar, Mikhail; Narayan, Anand; Morgenthaler, George W.; Smith, Gerald J.

    1998-01-01

    Control of air contaminants is a crucial factor in the safety considerations of crewed space flight. Indoor air quality needs to be closely monitored during long range missions such as a Mars mission, and also on large complex space structures such as the International Space Station. This work mainly pertains to the detection and simulation of air contaminants in the space station, though much of the work is easily extended to buildings, and issues of ventilation systems. Here we propose a method with which to track the presence of contaminants using an accurate physical model, and also develop a robust procedure that would raise alarms when certain tolerance levels are exceeded. A part of this research concerns the modeling of air flow inside a spacecraft, and the consequent dispersal pattern of contaminants. Our objective is to also monitor the contaminants on-line, so we develop a state estimation procedure that makes use of the measurements from a sensor system and determines an optimal estimate of the contamination in the system as a function of time and space. The real-time optimal estimates in turn are used to detect faults in the system and also offer diagnoses as to their sources. This work is concerned with the monitoring of air contaminants aboard future generation spacecraft and seeks to satisfy NASA's requirements as outlined in their Strategic Plan document (Technology Development Requirements, 1996).

  17. Geophysical Monitoring for Validation of Transient Permafrost Models (Invited)

    NASA Astrophysics Data System (ADS)

    Hauck, C.; Hilbich, C.; Marmy, A.; Scherler, M.

    2013-12-01

    Permafrost is a widespread phenomenon at high latitudes and high altitudes and describes the permanently frozen state of the subsurface in lithospheric material. In the context of climate change, both, new monitoring and modelling techniques are required to observe and predict potential permafrost changes, e.g. the warming and degradation which may lead to the liberation of carbon (Arctic) and the destabilisation of permafrost slopes (mountains). Mountain permafrost occurrences in the European Alps are characterised by temperatures only a few degrees below zero and are therefore particularly sensitive to projected climate changes in the 21st century. Traditional permafrost observation techniques are mainly based on thermal monitoring in vertical and horizontal dimension, but they provide only weak indications of physical properties such as ice or liquid water content. Geophysical techniques can be used to characterise permafrost occurrences and to monitor their changes as the physical properties of frozen and unfrozen ground measured by geophysical techniques are markedly different. In recent years, electromagnetic, seismic but especially electrical methods have been used to continuously monitor permafrost occurrences and to detect long-term changes within the active layer and regarding the ice content within the permafrost layer. On the other hand, coupled transient thermal/hydraulic models are used to predict the evolution of permafrost occurrences under different climate change scenarios. These models rely on suitable validation data for a certain observation period, which is usually restricted to data sets of ground temperature and active layer depth. Very important initialisation and validation data for permafrost models are, however, ground ice content and unfrozen water content in the active layer. In this contribution we will present a geophysical monitoring application to estimate ice and water content and their evolution in time at a permafrost station in

  18. Peculiarity of Porcine Amniotic Membrane and Its Derived Cells: A Contribution to the Study of Cell Therapy from a Large Animal Model.

    PubMed

    Lange-Consiglio, Anna; Corradetti, Bruna; Bertani, Sabrina; Notarstefano, Valentina; Perrini, Claudia; Marini, Maria Giovanna; Arrighi, Silvana; Bosi, Giampaolo; Belloli, Angelo; Pravettoni, Davide; Locatelli, Valentina; Cremonesi, Fausto; Bizzaro, Davide

    2015-12-01

    The aim of this work was to provide, for the first time, a protocol for isolation and characterization of stem cells from porcine amniotic membrane in view of their potential uses in regenerative medicine. From three samples of allanto-amnion recovered at delivery, the amniotic membrane was stripped from overlying allantois and digested with trypsin and collagenase to isolate epithelial (amniotic epithelial cells [AECs]) and mesenchymal cells, respectively. Proliferation, differentiation, and characterization studies by molecular biology and flow cytometry were performed. Histological examination revealed very few mesenchymal cells in the stromal layer, and a cellular yield of AECs of 10 × 10(6)/gram of digested tissue was achieved. AECs readily attached to plastic culture dishes displaying typical cuboidal morphology and, although their proliferative capacity decreased to the fifth passage, AECs showed a mean doubling time of 24.77 ± 6 h and a mean frequency of one fibroblast colony-forming unit (CFU-F) for every 116.75 plated cells. AECs expressed mesenchymal stem cell (MSC) mRNA markers (CD29, CD166, CD90, CD73, CD117) and pluripotent markers (Nanog and Oct 4), whereas they were negative for CD34 and MHCII. Mesodermic, ectodermic, and endodermic differentiation was confirmed by staining and expression of specific markers. We conclude that porcine amniotic membrane can provide an attractive source of stem cells that may be a useful tool for biomedical research. PMID:26540004

  19. Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling

    NASA Astrophysics Data System (ADS)

    La Loggia, Goffredo; Capodici, Fulvio; Ciraolo, Giuseppe; Drago, Aldo; Maltese, Antonino

    2011-11-01

    Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial surveillance and satellite images) research project on the synergistic use of remote sensing, forecasting, cleanup measures and environmental consequences. The paper also investigates techniques of oil spill detection using SAR images, presenting the first results of "Monitoring of marine pollution due to oil slick", a COSMO-SkyMed funded research project where X-band SAR constellation images provided by the Italian Space Agency are used. Finally, the prospect of using real time observations of marine surface conditions is presented through CALYPSO project (CALYPSO-HF Radar Monitoring System and Response against Marine Oil Spills in the Malta Channel), partly financed by the EU under the Operational Programme Italia-Malta 2007-2013. The project concerns the setting up of a permanent and fully operational HF radar observing system, capable of recording surface currents (in real-time with hourly updates) in the stretch of sea between Malta and Sicily. A combined use of collected data and numerical models, aims to optimize intervention and response in the case of marine oil spills.

  20. Electrical Resistivity Monitoring of Voids: Results of Dynamic Modeling Experiments

    NASA Astrophysics Data System (ADS)

    Lane, J. W.; Day-Lewis, F. D.; Singha, K.

    2006-05-01

    Remote, non-invasive detection of voids is a challenging problem for environmental and engineering investigations in karst terrain. Many geophysical methods including gravity, electrical, electromagnetic, magnetic, and seismic have potential to detect voids in the subsurface; lithologic heterogeneity and method- specific sources of noise, however, can mask the geophysical signatures of voids. New developments in automated, autonomous geophysical monitoring technology now allow for void detection using differential geophysics. We propose automated collection of electrical resistivity measurements over time. This dynamic approach exploits changes in subsurface electrical properties related to void growth or water-table fluctuation in order to detect voids that would be difficult or impossible to detect using static imaging approaches. We use a series of synthetic modeling experiments to demonstrate the potential of difference electrical resistivity tomography for finding (1) voids that develop vertically upward under a survey line (e.g., an incipient sinkhole); (2) voids that develop horizontally toward a survey line (e.g., a tunnel); and (3) voids that are influenced by changing hydrologic conditions (e.g., void saturation and draining). Synthetic datasets are simulated with a 3D finite-element model, but the inversion assumes a 2D forward model to mimic conventional practice. The results of the synthetic modeling experiments provide insights useful for planning and implementing field-scale monitoring experiments using electrical methods.

  1. Conceptual models as hypotheses in monitoring urban landscapes.

    PubMed

    Lookingbill, Todd R; Gardner, Robert H; Townsend, Philip A; Carter, Shawn L

    2007-08-01

    Many problems and challenges of ecosystem management currently are driven by the rapid pace and spatial extent of landscape change. Parks and reserves within areas of high human population density are especially challenged to meet the recreational needs of local populations and to preserve valued environmental resources. The complex problem of managing multiple objectives and multiple resources requires an enormous quantity of information, and conceptual models have been proposed as tools for organizing and interpreting this information. Academics generally prefer a bottom-up approach to model construction that emphasizes ecologic theory and process, whereas managers often use a top-down approach that takes advantage of existing information to address more pragmatic objectives. The authors propose a formal process for developing, applying, and testing conceptual models to be used in landscape monitoring that reconciles these seemingly opposing perspectives. The four-step process embraces the role of hypothesis testing in the development of models and evaluation of their utility. An example application of the process to a network of national parks in and around Washington, DC illustrates the ability of the approach to systematically identify monitoring data that would both advance ecologic theory and inform management decisions. PMID:17562105

  2. Conceptual Models as Hypotheses in Monitoring Urban Landscapes

    NASA Astrophysics Data System (ADS)

    Lookingbill, Todd R.; Gardner, Robert H.; Townsend, Philip A.; Carter, Shawn L.

    2007-08-01

    Many problems and challenges of ecosystem management currently are driven by the rapid pace and spatial extent of landscape change. Parks and reserves within areas of high human population density are especially challenged to meet the recreational needs of local populations and to preserve valued environmental resources. The complex problem of managing multiple objectives and multiple resources requires an enormous quantity of information, and conceptual models have been proposed as tools for organizing and interpreting this information. Academics generally prefer a bottom-up approach to model construction that emphasizes ecologic theory and process, whereas managers often use a top-down approach that takes advantage of existing information to address more pragmatic objectives. The authors propose a formal process for developing, applying, and testing conceptual models to be used in landscape monitoring that reconciles these seemingly opposing perspectives. The four-step process embraces the role of hypothesis testing in the development of models and evaluation of their utility. An example application of the process to a network of national parks in and around Washington, DC illustrates the ability of the approach to systematically identify monitoring data that would both advance ecologic theory and inform management decisions.

  3. Coastal Ecosystems and Climate Change: Is Modeling and Monitoring Enough?

    NASA Astrophysics Data System (ADS)

    Cronin, T. M.; Walker, H. A.

    2005-05-01

    Many coastal ecosystems are severely degraded due to a variety of human factors, requiring large and expensive monitoring and modeling efforts for restoration and management. Climate variability, including abrupt climate change, is seldom factored into coastal ecosystem management despite growing evidence for climate forcing of precipitation, river discharge, water quality, salinity, turbidity, faunal and phytoplankton dynamics, dissolved oxygen, and other ecosystem processes. We will review evidence from long-term monitoring records, multi-proxy paleoclimatic and paleoecological records, and climatic modeling that suggests that the effects of climate can override local and regional human activities and may potentially diminish the success of restoration efforts. Because ecosystem restoration often involves long-term objectives requiring decades to achieve, our focus will be on examples from sub-tropical and temperate estuaries in North America that show ecosystem response over decadal timescales to variability related to El Niño-Southern Oscillation, the Pacific Decadal Oscillation and the North Atlantic Oscillation. Climatic variability evident from paleo-records of the past few centuries exceeds that recorded in most 20th century monitoring records. This raises issues about the efficacy of local and regional ecosystem and hydrodynamic models designed to simulate ecosystem response to anthropogenic changes in sediment and nutrient input, fresh-water discharge, and land-use because such models, though tested with rigorous validation procedures, use calibration data sets limited to a few years. Thus, they might not be appropriate for simulating response to climatic extremes on the scale and duration of past events outside their calibration range. Understanding the complexities of ecosystem response to climatic forcing, especially in the context of local and regional ecosystem disturbance, raises formidable challenges, but attempts to integrate climate

  4. Osteogenic and adipogenic potential of porcine adipose mesenchymal stem cells.

    PubMed

    Qu, Chang-qing; Zhang, Guo-hua; Zhang, Li-jie; Yang, Gong-she

    2007-02-01

    Human, rat, and mouse studies have demonstrated the existence of a population of adipose mesenchymal stem cells (AMSCs) that can undergo multilineage differentiation in vitro. Understanding the clinical potential of AMSCs may require their use in preclinical large-animal models such as pigs. Thus, the objectives of this study were to establish a protocol for the isolation of porcine AMSCs from adipose tissue and to examine their ex vivo differentiation potential to adipocytes and osteoblast. The porcine AMSCs from passage 4 were selected for differentiation analysis. The adipocytes were identified morphologically by staining with Oil Red O, and the adipogenic marker genes were examined by RT-PCR technique. Osteogenic lineage was documented by deposition of calcium stained with Alzarin Red S, visualization of alkaline phosphatase activity, and expression of marker gene. Our result indicates that porcine AMSCs have been successfully isolated and induced differentiation into adipocytes and osteoblasts. This study suggested that porcine AMSCs are also a valuable model system for the study on the mesenchymal lineages for basic research and tissue engineering. PMID:17570023

  5. Porcine Reproductive and Respiratory Syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine reproductive and respiratory syndrome (PRRS) first appeared in the late 1980s, though serologic evidence indicates that it had been circulating in swine for some time prior to being recognized. PRRS has since become a highly significant infectious disease affecting swine production worldwid...

  6. Unilateral Partial Nephrectomy with Warm Ischemia Results in Acute Hypoxia Inducible Factor 1-Alpha (HIF-1α) and Toll-Like Receptor 4 (TLR4) Overexpression in a Porcine Model

    PubMed Central

    Zhang, Zhiyong; Haimovich, Beatrice; Kwon, Young Suk; Lu, Tyler; Fyfe-Kirschner, Billie; Olweny, Ephrem Odoy

    2016-01-01

    Purpose Ischemia/reperfusion (I/R) during partial nephrectomy (PN) contributes to acute kidney injury (AKI), which is inaccurately assessed using existent clinical markers of renal function. We evaluated I/R-related changes in expression in hypoxia inducible factor 1α (HIF-1α) and toll-like receptor 4 (TLR4), within kidney tissue and peripheral blood leukocytes (PBL) in a porcine model of PN. Materials and Methods Three adult pigs each underwent unilateral renal hilar cross clamping for 180 min followed by a 15 min reperfusion. The contralateral kidney served as control. Biopsies of clamped kidneys were obtained at baseline (time 0), every 60 min during the hypoxic phase, and post-reperfusion. Control kidneys were biopsied once at 180 min. Peripheral blood was sampled at time 0, every 30 min during the hypoxic phase, and post-reperfusion. HIF-1α and TLR4 expression in kidney tissue and PBL were analyzed by Western blotting. I/R-related histological changes were assessed. Results Expression of HIF-1α in clamped kidneys and PBL was below detection level at baseline, rising to detectable levels after 60 min of hypoxia, and continuing to rise throughout the hypoxic and reperfusion phases. Expression of TLR-4 in clamped kidneys followed a similar trend with initial detection after 30–60 min of hypoxia. Control kidneys exhibited no change in HIF-1α or TLR-4 expression. I/R-related histologic changes were minimal, primarily mild tubular dilatation. Conclusions In a porcine model of PN, HIF-1α and TLR4 exhibited robust, I/R-related increases in expression in kidney tissue and PBL. Further studies investigating these molecules as potential markers of AKI are warranted. PMID:27149666

  7. Meteor velocity distribution and an optimum monitoring mathematical model

    NASA Technical Reports Server (NTRS)

    Volkov, N. G.; Salimov, O. N.

    1987-01-01

    At present, there are a great number of radio meteor, ionosphere and rocket observation data for the altitude range of 80 to 100 km which indicate the existence of large scale circulation systems in the mesopause to low thermosphere range which change regularly with season and latitude. But the existing observation network and observation programs are not optimal for revealing the main factors forming the circulation mode at these altitudes. A generalized optimum monitoring mathematical model is offered for consideration. The model input data are distribution density, response function, individual measurement root mean square uncertainty and detection effectiveness function. The model makes it possible to obtain the observation distribution density, the minimal possible dispersion and optimized system effectiveness.

  8. Polarimetric SAR Models for Oil Fields Monitoring in China Seas

    NASA Astrophysics Data System (ADS)

    Buono, A.; Nunziata, F.; Li, X.; Wei, Y.; Ding, X.

    2014-11-01

    In this study, physical-based models for polarimetric Synthetic Aperture Radar (SAR) oil fields monitoring are proposed. They all share a physical rationale relying on the different scattering mechanisms that characterize a free sea surface, an oil slick-covered sea surface, and a metallic target. In fact, sea surface scattering is well modeled by a Bragg-like behaviour, while a strong departure from Bragg scattering is in place when dealing with oil slicks and targets. Furthermore, the proposed polarimetric models aim at addressing simultaneously target and oil slick detection, providing useful extra information with respect to single-pol SAR data in order to approach oil discrimination and classification. Experiments undertaken over East and South China Sea from actual C-band RadarSAT-2 full-pol SAR data witness the soundness of the proposed rationale.

  9. Mouse retrovirus mediates porcine endogenous retrovirus transmission into human cells in long-term human-porcine chimeric mice

    PubMed Central

    Yang, Yong-Guang; Wood, James C.; Lan, Ping; Wilkinson, Robert A.; Sykes, Megan; Fishman, Jay A.; Patience, Clive

    2004-01-01

    Porcine endogenous retrovirus (PERV) is a potential pathogen in clinical xenotransplantation; transmission of PERV in vivo has been suggested in murine xenotransplantation models. We analyzed the transmission of PERV to human cells in vivo using a model in which immunodeficient NOD/SCID transgenic mice were transplanted with porcine and human lymphohematopoietic tissues. Our results demonstrate, we believe for the first time, that human and pig cells can coexist long-term (up to 25 weeks) without direct PERV infection of human cells. Despite the transplantation of porcine cells that did not produce human-tropic PERV, human cells from the chimeric mice were frequently found to contain PERV sequences. However, this transmission was due to the pseudotyping of PERV-C (a virus without human tropism) by xenotropic murine leukemia virus, rather than to de novo generation of human-tropic PERV. Thus, pseudotyping might account for the PERV transmission previously observed in mice. The absence of direct human cell infection following long-term in vivo coexistence with large numbers of porcine cells provides encouragement regarding the potential safety of using pigs that do not produce human-tropic PERV as source animals for transplantation to humans. PMID:15343388

  10. Automated medical diagnosis with fuzzy stochastic models: monitoring chronic diseases.

    PubMed

    Jeanpierre, Laurent; Charpillet, François

    2004-01-01

    As the world population ages, the patients per physician ratio keeps on increasing. This is even more important in the domain of chronic pathologies where people are usually monitored for years and need regular consultations. To address this problem, we propose an automated system to monitor a patient population, detecting anomalies in instantaneous data and in their temporal evolution, so that it could alert physicians. By handling the population of healthy patients autonomously and by drawing the physicians' attention to the patients-at-risk, the system allows physicians to spend comparatively more time with patients who need their services. In such a system, the interaction between the patients, the diagnosis module, and the physicians is very important. We have based this system on a combination of stochastic models, fuzzy filters, and strong medical semantics. We particularly focused on a particular tele-medicine application: the Diatelic Project. Its objective is to monitor chronic kidney-insufficient patients and to detect hydration troubles. During two years, physicians from the ALTIR have conducted a prospective randomized study of the system. This experiment clearly shows that the proposed system is really beneficial to the patients' health. PMID:15520535

  11. Monitoring and modeling agricultural drought for famine early warning (Invited)

    NASA Astrophysics Data System (ADS)

    Verdin, J. P.; Funk, C.; Budde, M. E.; Lietzow, R.; Senay, G. B.; Smith, R.; Pedreros, D.; Rowland, J.; Artan, G. A.; Husak, G. J.; Michaelsen, J.; Adoum, A.; Galu, G.; Magadzire, T.; Rodriguez, M.

    2009-12-01

    The Famine Early Warning Systems Network (FEWS NET) makes quantitative estimates of food insecure populations, and identifies the places and periods during which action must be taken to assist them. Subsistence agriculture and pastoralism are the predominant livelihood systems being monitored, and they are especially drought-sensitive. At the same time, conventional climate observation networks in developing countries are often sparse and late in reporting. Consequently, remote sensing has played a significant role since FEWS NET began in 1985. Initially there was heavy reliance on vegetation index imagery from AVHRR to identify anomalies in landscape greenness indicative of drought. In the latter part of the 1990s, satellite rainfall estimates added a second, independent basis for identification of drought. They are used to force crop water balance models for the principal rainfed staple crops in twenty FEWS NET countries. Such models reveal seasonal moisture deficits associated with yield reduction on a spatially continuous basis. In 2002, irrigated crops in southwest Asia became a concern, and prompted the implementation of a gridded energy balance model to simulate the seasonal mountain snow pack, the main source of irrigation water. MODIS land surface temperature data are also applied in these areas to directly estimate actual seasonal evapotranspiration on the irrigated lands. The approach reveals situations of reduced irrigation water supply and crop production due to drought. The availability of MODIS data after 2000 also brought renewed interest in vegetation index imagery. MODIS NDVI data have proven to be of high quality, thanks to significant spectral and spatial resolution improvements over AVHRR. They are vital to producing rapid harvest assessments for drought-impacted countries in Africa and Asia. The global food crisis that emerged in 2008 has led to expansion of FEWS NET monitoring to over 50 additional countries. Unlike previous practice, these

  12. Blood gas and hematological changes in experimental peracute porcine pleuropneumonia.

    PubMed Central

    Kiorpes, A L; MacWilliams, P S; Schenkman, D I; Bäckström, L R

    1990-01-01

    The effect of experimental, peracute, porcine pleuropneumonia on arterial blood gases, acid base status, the leukogram, and gross and microscopic lung structure was studied in nine growing pigs (mean weight +/- SD 10.6 +/- 2.0 kg). Pigs were inoculated intranasally with a virulent serotype 5 isolate of Actinobacillus pleuropneumoniae, and all showed signs typical of the disease within four hours. Death occurred in all pigs from 4.5 to 32 hours postinoculation (mean 14 hours). Gross and microscopic changes were typical of porcine pleuropneumonia in all pigs. Changes in the leukogram included a rapid decline in total white cells, segmented neutrophils, lymphocytes, monocytes, and eosinophils. Pigs maintained alveolar ventilation throughout the study as arterial CO2 tension was unchanged; however, arterial O2 tension and pH decreased from (mean +/- SD) 95.2 +/- 5.7 torr and 7.463 +/- 0.018 at baseline to 62.1 +/- 12.3 torr and 7.388 +/- 0.045, respectively, within 90 minutes prior to death. The data showed that in this model of peracute porcine pleuropneumonia, progressive ventilatory failure was not a feature of the disease, and the blood gas values and acid base status were maintained within physiological ranges. The histopathological hematological and physiological findings were consistent with the hypothesis that peracute porcine pleuropneumonia resembles septic shock. Images Fig. 2. Fig. 3. PMID:2106382

  13. Molecular interactions of a model bile salt and porcine bile with (1,3:1,4)-β-glucans and arabinoxylans probed by (13)C NMR and SAXS.

    PubMed

    Gunness, Purnima; Flanagan, Bernadine M; Mata, Jitendra P; Gilbert, Elliot P; Gidley, Michael J

    2016-04-15

    Two main classes of interaction between soluble dietary fibres (SDFs), such as (1,3:1,4)-β-D-glucan (βG) and arabinoxylan (AX) and bile salt (BS) or diluted porcine bile, were identified by (13)C NMR and small angle X-ray scattering (SAXS). Small chemical shift differences of BS NMR resonances were consistent with effective local concentration or dilution of BS micelles mostly by βG, suggesting dynamic interactions; whilst the reduced line widths/intensities observed were mostly caused by wheat AX and the highest molecular size and concentrations of βG. SAXS showed evidence of changes in βG but not AX in the presence of BS micelles, at >13 nm length scale consistent with molecular level interactions. Thus intermolecular interactions between SDF and BS depend on both SDF source and its molecular weight and may occur alone or in combination. PMID:26617003

  14. A model for the dynamic nuclear/nucleolar/cytoplasmic trafficking of the porcine reproductive and respiratory syndrome virus (PRRSV) nucleocapsid protein based on live cell imaging

    SciTech Connect

    You, Jae-Hwan; Howell, Gareth; Pattnaik, Asit K.; Osorio, Fernando A.; Hiscox, Julian A.

    2008-08-15

    Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus, in common with many other positive strand RNA viruses, encodes a nucleocapsid (N) protein which can localise not only to the cytoplasm but also to the nucleolus in virus-infected cells and cells over-expressing N protein. The dynamic trafficking of positive strand RNA virus nucleocapsid proteins and PRRSV N protein in particular between the cytoplasm and nucleolus is unknown. In this study live imaging of permissive and non-permissive cell lines, in conjunction with photo-bleaching (FRAP and FLIP), was used to investigate the trafficking of fluorescent labeled (EGFP) PRRSV-N protein. The data indicated that EGFP-PRRSV-N protein was not permanently sequestered to the nucleolus and had equivalent mobility to cellular nucleolar proteins. Further the nuclear import of N protein appeared to occur faster than nuclear export, which may account for the observed relative distribution of N protein between the cytoplasm and the nucleolus.

  15. Advanced modelling, monitoring, and process control of bioconversion systems

    NASA Astrophysics Data System (ADS)

    Schmitt, Elliott C.

    Production of fuels and chemicals from lignocellulosic biomass is an increasingly important area of research and industrialization throughout the world. In order to be competitive with fossil-based fuels and chemicals, maintaining cost-effectiveness is critical. Advanced process control (APC) and optimization methods could significantly reduce operating costs in the biorefining industry. Two reasons APC has previously proven challenging to implement for bioprocesses include: lack of suitable online sensor technology of key system components, and strongly nonlinear first principal models required to predict bioconversion behavior. To overcome these challenges batch fermentations with the acetogen Moorella thermoacetica were monitored with Raman spectroscopy for the conversion of real lignocellulosic hydrolysates and a kinetic model for the conversion of synthetic sugars was developed. Raman spectroscopy was shown to be effective in monitoring the fermentation of sugarcane bagasse and sugarcane straw hydrolysate, where univariate models predicted acetate concentrations with a root mean square error of prediction (RMSEP) of 1.9 and 1.0 g L-1 for bagasse and straw, respectively. Multivariate partial least squares (PLS) models were employed to predict acetate, xylose, glucose, and total sugar concentrations for both hydrolysate fermentations. The PLS models were more robust than univariate models, and yielded a percent error of approximately 5% for both sugarcane bagasse and sugarcane straw. In addition, a screening technique was discussed for improving Raman spectra of hydrolysate samples prior to collecting fermentation data. Furthermore, a mechanistic model was developed to predict batch fermentation of synthetic glucose, xylose, and a mixture of the two sugars to acetate. The models accurately described the bioconversion process with an RMSEP of approximately 1 g L-1 for each model and provided insights into how kinetic parameters changed during dual substrate

  16. Monitoring and modelling terbuthylazine and desethyl-terbuthylazine in groundwater.

    NASA Astrophysics Data System (ADS)

    Fait, G.; Balderacchi, M.; Ferrari, F.; Capri, E.; Trevisan, M.

    2009-04-01

    the future. Therefore, after the monitoring study the leaching of terbuthylazine and desethyl-terbuthylazine in groundwater was simulated with the aim to: 1) to verify a possible dilution effect due to lateral recharge; 2) to verify that the sampling time during the monitoring study was appropriate; 3) to verify the leaching of the metabolites in time. The model MACRO (version 5.1) was used. MACRO is a physically based one-dimensional model, which considers preferential flow (i.e. 'micropores' and 'macropores') to describe the transport of water and solutes in soils. Using the data coming from the monitoring (i.e.: soil, climatic, geology and hydrological data) a scenario was set in each of the eleven Italian sites monitored from 2005 to 2007. A maize monoculture was simulated for 20 years in each site, with a pre-emergence treatment every year. Daily measurements of groundwater table depth were available for each site, and then these data were used in order to reach a good calibration of the soil hydrology. Two sets of soil data were used: soil data acquired from the analysis of the soil core sampled in each site and soil data of the corresponding reference profile obtained from the regional soil maps. Furthermore, in order to estimate soil hydraulic parameters, two sets of pedotransfer functions were used: one developed for the northern Europe soils and one developed for the Po Valley soils. The results showed that the groundwater table depth simulated fitted quite well with the measured data, and then it was demonstrated that the groundwater recharge was constant in time. Only in one site measured and simulated groundwater table depth did not match to each other. This case suggested that hydrological equilibrium was not given only by precipitation/irrigation and evapotranspiration, then lateral or bottom recharge and a consequent dilution effect were assumed. Furthermore, in order to estimate the lateral recharge "Darcy's Law" was applied and it was demonstrated

  17. Comparison of autologous 111In-leukocytes, 18F-FDG, 11C-methionine, 11C-PK11195 and 68Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous staphylococcus aureus osteomyelitis model

    PubMed Central

    Nielsen, Ole L; Afzelius, Pia; Bender, Dirk; Schønheyder, Henrik C; Leifsson, Páll S; Nielsen, Karin M; Larsen, Jytte O; Jensen, Svend B; Alstrup, Aage KO

    2015-01-01

    The aim of this study was to compare 111In-labeled leukocyte single-photon emission computed tomography (SPECT) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve detection of osteomyelitis. We chose 11C-methionine, 11C-PK11195 and 68Ga-citrate and validated their diagnostic utility in a porcine haematogenous osteomyelitis model. Four juvenile 14-15 weeks old female pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of Staphylococcus aureus using a sequential scan protocol with 18F-FDG, 68Ga-citrate, 11C-methionine, 11C-PK11195, 99mTc-Nanocoll and 111In-labelled autologous leukocytes. This was followed by necropsy of the pigs and gross pathology, histopathology and microbial examination. The pigs developed a total of five osteomyelitis lesions, five lesions characterized as abscesses/cellulitis, arthritis in three joints and five enlarged lymph nodes. None of the tracers accumulated in joints with arthritis. By comparing the 10 infectious lesions, 18F-FDG accumulated in nine, 111In-leukocytes in eight, 11C-methionine in six, 68Ga-citrate in four and 11C-PK11195 accumulated in only one lesion. Overall, 18F-FDG PET was superior to 111In-leukocyte SPECT in marking infectious and proliferative, i.e. hyperplastic, lesions. However, leukocyte SPECT was performed as early scans, approximately 6 h after injection of the leukocytes, to match the requirements of the 18 h long scan protocol. 11C-methionine and possibly 68Ga-citrate may be useful for diagnosis of soft issue lesions. PMID:25973338

  18. Comparison of autologous (111)In-leukocytes, (18)F-FDG, (11)C-methionine, (11)C-PK11195 and (68)Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous staphylococcus aureus osteomyelitis model.

    PubMed

    Nielsen, Ole L; Afzelius, Pia; Bender, Dirk; Schønheyder, Henrik C; Leifsson, Páll S; Nielsen, Karin M; Larsen, Jytte O; Jensen, Svend B; Alstrup, Aage Ko

    2015-01-01

    The aim of this study was to compare (111)In-labeled leukocyte single-photon emission computed tomography (SPECT) and (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve detection of osteomyelitis. We chose (11)C-methionine, (11)C-PK11195 and (68)Ga-citrate and validated their diagnostic utility in a porcine haematogenous osteomyelitis model. Four juvenile 14-15 weeks old female pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of Staphylococcus aureus using a sequential scan protocol with (18)F-FDG, (68)Ga-citrate, (11)C-methionine, (11)C-PK11195, (99m)Tc-Nanocoll and (111)In-labelled autologous leukocytes. This was followed by necropsy of the pigs and gross pathology, histopathology and microbial examination. The pigs developed a total of five osteomyelitis lesions, five lesions characterized as abscesses/cellulitis, arthritis in three joints and five enlarged lymph nodes. None of the tracers accumulated in joints with arthritis. By comparing the 10 infectious lesions, (18)F-FDG accumulated in nine, (111)In-leukocytes in eight, (11)C-methionine in six, (68)Ga-citrate in four and (11)C-PK11195 accumulated in only one lesion. Overall, (18)F-FDG PET was superior to (111)In-leukocyte SPECT in marking infectious and proliferative, i.e. hyperplastic, lesions. However, leukocyte SPECT was performed as early scans, approximately 6 h after injection of the leukocytes, to match the requirements of the 18 h long scan protocol. (11)C-methionine and possibly (68)Ga-citrate may be useful for diagnosis of soft issue lesions. PMID:25973338

  19. Magnetic resonance Elastography of the Lung parenchyma in an in situ porcine model with a non-invasive mechanical driver: Correlation of Shear Stiffness with Trans-respiratory system Pressures

    PubMed Central

    Mariappan, Yogesh K; Kolipaka, Arunark; Manduca, Armando; Hubmayr, Rolf D; Ehman, Richard L; Araoz, Philip; McGee, Kiaran P

    2011-01-01

    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 (MRE) 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 1H based MRE 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 (Pao) in 10 adult pigs. In all animals, shear stiffness was successfully quantified at four different Pao 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 Pao values of 5, 10, 15 and 20 cm H2O respectively. Shear stiffness increased with increasing Pao, in agreement with the literature. It is concluded that in an in situ porcine lung shear stiffness can be quantitated with 1H MRE using a noninvasive mechanical driver, and that it is feasible to measure the change in shear stiffness due to change in Pao. PMID:21590723

  20. Metabolic Pattern of the Acute Phase of Subarachnoid Hemorrhage in a Novel Porcine Model: Studies with Cerebral Microdialysis with High Temporal Resolution

    PubMed Central

    Nyberg, Christoffer; Karlsson, Torbjörn; Hillered, Lars; Engström, Elisabeth Ronne

    2014-01-01

    Background Aneurysmal subarachnoid hemorrhage (SAH) may produce cerebral ischemia and systemic responses including stress. To study immediate cerebral and systemic changes in response to aneurysm rupture, animal models are needed. Objective To study early cerebral energy changes in an animal model. Methods Experimental SAH was induced in 11 pigs by autologous blood injection to the anterior skull base, with simultaneous control of intracranial and cerebral perfusion pressures. Intracerebral microdialysis was used to monitor concentrations of glucose, pyruvate and lactate. Results In nine of the pigs, a pattern of transient ischemia was produced, with a dramatic reduction of cerebral perfusion pressure soon after blood injection, associated with a quick glucose and pyruvate decrease. This was followed by a lactate increase and a delayed pyruvate increase, producing a marked but short elevation of the lactate/pyruvate ratio. Glucose, pyruvate, lactate and lactate/pyruvate ratio thereafter returned toward baseline. The two remaining pigs had a more severe metabolic reaction with glucose and pyruvate rapidly decreasing to undetectable levels while lactate increased and remained elevated, suggesting persisting ischemia. Conclusion The animal model simulates the conditions of SAH not only by deposition of blood in the basal cisterns, but also creating the transient global ischemic impact of aneurysmal SAH. The metabolic cerebral changes suggest immediate transient substrate failure followed by hypermetabolism of glucose upon reperfusion. The model has features that resemble spontaneous bleeding, and is suitable for future research of the early cerebral and systemic responses to SAH that are difficult to study in humans. PMID:24940881

  1. Characterization of the porcine synovial fluid proteome and a comparison to the plasma proteome.

    PubMed

    Bennike, Tue Bjerg; Barnaby, Omar; Steen, Hanno; Stensballe, Allan

    2015-12-01

    Synovial fluid is present in all joint cavities, and protects the articular cartilage surfaces in large by lubricating the joint, thus reducing friction. Several studies have described changes in the protein composition of synovial fluid in patients with joint disease. However, the protein concentration, content, and synovial fluid volume change dramatically during active joint diseases and inflammation, and the proteome composition of healthy synovial fluid is incompletely characterized. We performed a normative proteomics analysis of porcine synovial fluid, and report data from optimizing proteomic methods to investigate the proteome of healthy porcine synovial fluid (Bennike et al., 2014 [1]). We included an evaluation of different proteolytic sample preparation techniques, and an analysis of posttranslational modifications with a focus on glycosylation. We used pig (Sus Scrofa) as a model organism, as the porcine immune system is highly similar to human and the pig genome is sequenced. Furthermore, porcine model systems are commonly used large animal models to study several human diseases. In addition, we analyzed the proteome of human plasma, and compared the proteomes to the obtained porcine synovial fluid proteome. The proteome of the two body fluids were found highly similar, underlining the detected plasma derived nature of many synovial fluid components. The healthy porcine synovial fluid proteomics data, human rheumatoid arthritis synovial fluid proteomics data used in the method optimization, human plasma proteomics data, and search results, have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD000935. PMID:26543887

  2. Characterization of the porcine synovial fluid proteome and a comparison to the plasma proteome

    PubMed Central

    Bennike, Tue Bjerg; Barnaby, Omar; Steen, Hanno; Stensballe, Allan

    2015-01-01

    Synovial fluid is present in all joint cavities, and protects the articular cartilage surfaces in large by lubricating the joint, thus reducing friction. Several studies have described changes in the protein composition of synovial fluid in patients with joint disease. However, the protein concentration, content, and synovial fluid volume change dramatically during active joint diseases and inflammation, and the proteome composition of healthy synovial fluid is incompletely characterized. We performed a normative proteomics analysis of porcine synovial fluid, and report data from optimizing proteomic methods to investigate the proteome of healthy porcine synovial fluid (Bennike et al., 2014 [1]). We included an evaluation of different proteolytic sample preparation techniques, and an analysis of posttranslational modifications with a focus on glycosylation. We used pig (Sus Scrofa) as a model organism, as the porcine immune system is highly similar to human and the pig genome is sequenced. Furthermore, porcine model systems are commonly used large animal models to study several human diseases. In addition, we analyzed the proteome of human plasma, and compared the proteomes to the obtained porcine synovial fluid proteome. The proteome of the two body fluids were found highly similar, underlining the detected plasma derived nature of many synovial fluid components. The healthy porcine synovial fluid proteomics data, human rheumatoid arthritis synovial fluid proteomics data used in the method optimization, human plasma proteomics data, and search results, have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD000935. PMID:26543887

  3. Structural and functional annotation of the porcine immunome

    PubMed Central

    2013-01-01

    Background The domestic pig is known as an excellent model for human immunology and the two species share many pathogens. Susceptibility to infectious disease is one of the major constraints on swine performance, yet the structure and function of genes comprising the pig immunome are not well-characterized. The completion of the pig genome provides the opportunity to annotate the pig immunome, and compare and contrast pig and human immune systems. Results The Immune Response Annotation Group (IRAG) used computational curation and manual annotation of the swine genome assembly 10.2 (Sscrofa10.2) to refine the currently available automated annotation of 1,369 immunity-related genes through sequence-based comparison to genes in other species. Within these genes, we annotated 3,472 transcripts. Annotation provided evidence for gene expansions in several immune response families, and identified artiodactyl-specific expansions in the cathelicidin and type 1 Interferon families. We found gene duplications for 18 genes, including 13 immune response genes and five non-immune response genes discovered in the annotation process. Manual annotation provided evidence for many new alternative splice variants and 8 gene duplications. Over 1,100 transcripts without porcine sequence evidence were detected using cross-species annotation. We used a functional approach to discover and accurately annotate porcine immune response genes. A co-expression clustering analysis of transcriptomic data from selected experimental infections or immune stimulations of blood, macrophages or lymph nodes identified a large cluster of genes that exhibited a correlated positive response upon infection across multiple pathogens or immune stimuli. Interestingly, this gene cluster (cluster 4) is enriched for known general human immune response genes, yet contains many un-annotated porcine genes. A phylogenetic analysis of the encoded proteins of cluster 4 genes showed that 15% exhibited an accelerated

  4. Porcine acellular lung matrix for wound healing and abdominal wall reconstruction: A pilot study

    PubMed Central

    Fernandez-Moure, Joseph S; Van Eps, Jeffrey L; Rhudy, Jessica R; Cabrera, Fernando J; Acharya, Ghanashyam S; Tasciotti, Ennio; Sakamoto, Jason; Nichols, Joan E

    2016-01-01

    Surgical wound healing applications require bioprosthetics that promote cellular infiltration and vessel formation, metrics associated with increased mechanical strength and resistance to infection. Porcine acellular lung matrix is a novel tissue scaffold known to promote cell adherence while minimizing inflammatory reactions. In this study, we evaluate the capacity of porcine acellular lung matrix to sustain cellularization and neovascularization in a rat model of subcutaneous implantation and chronic hernia repair. We hypothesize that, compared to human acellular dermal matrix, porcine acellular lung matrix would promote greater cell infiltration and vessel formation. Following pneumonectomy, porcine lungs were processed and characterized histologically and by scanning electron microscopy to demonstrate efficacy of the decellularization. Using a rat model of subcutaneou implantation, porcine acellular lung matrices (n = 8) and human acellular dermal matrices (n = 8) were incubated in vivo for 6 weeks. To evaluate performance under mechanically stressed conditions, porcine acellular lung matrices (n = 7) and human acellular dermal matrices (n = 7) were implanted in a rat model of chronic ventral incisional hernia repair for 6 weeks. After 6 weeks, tissues were evaluated using hematoxylin and eosin and Masson’s trichrome staining to quantify cell infiltration and vessel formation. Porcine acellular lung matrices were shown to be successfully decellularized. Following subcutaneous implantation, macroscopic vessel formation was evident. Porcine acellular lung matrices demonstrated sufficient incorporation and showed no evidence of mechanical failure after ventral hernia repair. Porcine acellular lung matrices demonstrated significantly greater cellular density and vessel formation when compared to human acellular dermal matrix. Vessel sizes were similar across all groups. Cell infiltration and vessel formation are well-characterized metrics of incorporation

  5. Porcine acellular lung matrix for wound healing and abdominal wall reconstruction: A pilot study.

    PubMed

    Fernandez-Moure, Joseph S; Van Eps, Jeffrey L; Rhudy, Jessica R; Cabrera, Fernando J; Acharya, Ghanashyam S; Tasciotti, Ennio; Sakamoto, Jason; Nichols, Joan E

    2016-01-01

    Surgical wound healing applications require bioprosthetics that promote cellular infiltration and vessel formation, metrics associated with increased mechanical strength and resistance to infection. Porcine acellular lung matrix is a novel tissue scaffold known to promote cell adherence while minimizing inflammatory reactions. In this study, we evaluate the capacity of porcine acellular lung matrix to sustain cellularization and neovascularization in a rat model of subcutaneous implantation and chronic hernia repair. We hypothesize that, compared to human acellular dermal matrix, porcine acellular lung matrix would promote greater cell infiltration and vessel formation. Following pneumonectomy, porcine lungs were processed and characterized histologically and by scanning electron microscopy to demonstrate efficacy of the decellularization. Using a rat model of subcutaneou implantation, porcine acellular lung matrices (n = 8) and human acellular dermal matrices (n = 8) were incubated in vivo for 6 weeks. To evaluate performance under mechanically stressed conditions, porcine acellular lung matrices (n = 7) and human acellular dermal matrices (n = 7) were implanted in a rat model of chronic ventral incisional hernia repair for 6 weeks. After 6 weeks, tissues were evaluated using hematoxylin and eosin and Masson's trichrome staining to quantify cell infiltration and vessel formation. Porcine acellular lung matrices were shown to be successfully decellularized. Following subcutaneous implantation, macroscopic vessel formation was evident. Porcine acellular lung matrices demonstrated sufficient incorporation and showed no evidence of mechanical failure after ventral hernia repair. Porcine acellular lung matrices demonstrated significantly greater cellular density and vessel formation when compared to human acellular dermal matrix. Vessel sizes were similar across all groups. Cell infiltration and vessel formation are well-characterized metrics of incorporation

  6. Fluorescence spectroscopy and chemometric modeling for bioprocess monitoring.

    PubMed

    Faassen, Saskia M; Hitzmann, Bernd

    2015-01-01

    On-line sensors for the detection of crucial process parameters are desirable for the monitoring, control and automation of processes in the biotechnology, food and pharma industry. Fluorescence spectroscopy as a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states. During a cultivation process significant changes occur in the fluorescence spectra. By means of chemometric modeling, prediction models can be calculated and applied for process supervision and control to provide increased quality and the productivity of bioprocesses. A range of applications for different microorganisms and analytes has been proposed during the last years. This contribution provides an overview of different analysis methods for the measured fluorescence spectra and the model-building chemometric methods used for various microbial cultivations. Most of these processes are observed using the BioView® Sensor, thanks to its robustness and insensitivity to adverse process conditions. Beyond that, the PLS-method is the most frequently used chemometric method for the calculation of process models and prediction of process variables. PMID:25942644

  7. Fluorescence Spectroscopy and Chemometric Modeling for Bioprocess Monitoring

    PubMed Central

    Faassen, Saskia M.; Hitzmann, Bernd

    2015-01-01

    On-line sensors for the detection of crucial process parameters are desirable for the monitoring, control and automation of processes in the biotechnology, food and pharma industry. Fluorescence spectroscopy as a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states. During a cultivation process significant changes occur in the fluorescence spectra. By means of chemometric modeling, prediction models can be calculated and applied for process supervision and control to provide increased quality and the productivity of bioprocesses. A range of applications for different microorganisms and analytes has been proposed during the last years. This contribution provides an overview of different analysis methods for the measured fluorescence spectra and the model-building chemometric methods used for various microbial cultivations. Most of these processes are observed using the BioView® Sensor, thanks to its robustness and insensitivity to adverse process conditions. Beyond that, the PLS-method is the most frequently used chemometric method for the calculation of process models and prediction of process variables. PMID:25942644

  8. Stochastic model to monitor mechanical vibrations in pressurized water reactors

    SciTech Connect

    Shieh, D.J.; Upadhyaya, B.R.

    1984-01-01

    The feasibility of using neutron flux and core-exit temperature signals in PWRs for estimating core coolant flow velocity has been demonstrated using normal operational data from both the LOFT reactor and a commerical PWR. The LOFT analysis further showed that the core coolant velocity can be accurately monitored for various flow rates using the linear phase-frequency relationship in the frequency range 0.1 to 2 Hz. The development of the technique for monitoring core coolant velocity in PWRs provides a valuable alternative for flow measurement. Theoretical studies of core heat transfer in PWRs showed that the fluctuating heat sources have a dominating effect on the core-exit temperature compared to fluctuations of the coolant flow rate and core inlet coolant temperature. In the present analysis a detailed distributed parameter model of a PWR core was developed with the purpose of studying the following aspects of core coolant flow rate measurement: the mechanisms causing linear phase relationship between neutron flux and coolant temperature signals due to various perturbation sources; the effect of axial flux shape on the phase slope (or estimated transit delay time); and the relationship between transit delay time and effective distance of temperature noise propagation to maintain the flow velocity invariant.

  9. Watershed monitoring and modelling and USA regulatory compliance.

    PubMed

    Turner, B G; Boner, M C

    2004-01-01

    The aim of the Columbus program was to implement a comprehensive watershed monitoring-network including water chemistry, aquatic biology and alternative sensors to establish water environment health and methods for determining future restoration progress and early warning for protection of drinking water supplies. The program was implemented to comply with USA regulatory requirements including Total Maximum Daily Load (TMDL) rules of the Clean Water Act (CWA) and Source Water Assessment and Protection (SWAP) rules under the Safe Drinking Water Act (SDWA). The USEPA Office of Research and Development and the Water Environment Research Foundation provided quality assurance oversight. The results obtained demonstrated that significant wet weather data is necessary to establish relationships between land use, water chemistry, aquatic biology and sensor data. These measurements and relationships formed the basis for calibrating the US EPA BASINS Model, prioritizing watershed health and determination of compliance with water quality standards. Conclusions specify priorities of cost-effective drainage system controls that attenuate stormwater flows and capture flushed pollutants. A network of permanent long-term real-time monitoring using combination of continuous sensor measurements, water column sampling and aquatic biology surveys and a regional organization is prescribed to protect drinking water supplies and measure progress towards water quality targets. PMID:15685974

  10. Mechanical characterization of porcine corneas.

    PubMed

    Boschetti, F; Triacca, V; Spinelli, L; Pandolfi, A

    2012-03-01

    An experimental program has been carried out in order to investigate the mechanical behavior of porcine corneas. We report the results of inflation tests on the whole cornea and uniaxial tests on excised corneal strips, performed on 51 fresh porcine eyes. Uniaxial tests have been performed on specimens cut from previously inflated corneas. The cornea behavior is characterized by means of elastic stiffness, measured on both average pressure-apex displacement and average uniaxial stress-strain curves; and by means of transversal contraction coefficient, peak stress, and failure stress measured on uniaxial stress-strain curves. Uniaxial tests performed on excised strips allowed to measure the anisotropy in the corneal stiffness and to compare the stiffness of the cornea with the one of the sclera. Viscous properties of the cornea have been obtained through uniaxial relaxation curves on excised corneal strips. The relevant geometrical parameters have been measured and, with the aid of the elastic thin shell theory, a stress-strain curve has been derived from the average inflation test data and compared with similar data available in the literature. The experimental system has been developed in view of future applications to the mechanical testing of both porcine and human corneas. PMID:22482683

  11. Immunodiagnosis of porcine cysticercosis: identification of candidate antigens through immunoproteomics.

    PubMed

    Diaz-Masmela, Yuliet; Fragoso, Gladis; Ambrosio, Javier R; Mendoza-Hernández, Guillermo; Rosas, Gabriela; Estrada, Karel; Carrero, Julio César; Sciutto, Edda; Laclette, Juan P; Bobes, Raúl J

    2013-12-01

    Cysticercosis, caused by the larval stage of Taenia solium, is a zoonotic disease affecting pigs and humans that is endemic to developing countries in Latin America, Africa and South East Asia. The prevalence of infection in pigs, the intermediate host for T. solium, has been used as an indicator for monitoring disease transmission in endemic areas. However, accurate and specific diagnostic tools for porcine cysticercosis remain to be established. Using proteomic approaches and the T. solium genome sequence, seven antigens were identified as specific for porcine cysticercosis, namely, tropomyosin 2, alpha-1 tubulin, beta-tubulin 2, annexin B1, small heat-shock protein, 14-3-3 protein, and cAMP-dependent protein kinase. None of these proteins were cross-reactive when tested with sera from pigs infected with Ascaris spp., Cysticercus tenuicollis and hydatid cysts of Echinococcus spp. or with serum from a Taenia saginata-infected cow. Comparison with orthologues, indicated that the amino acid sequences of annexin B1 and cAMP-dependent protein kinase possessed highly specific regions, which might make them suitable candidates for development of a specific diagnostic assay for porcine cysticercosis. PMID:24161749

  12. Monitoring with Trackers Based on Semi-Quantitative Models

    NASA Technical Reports Server (NTRS)

    Kuipers, Benjamin

    1997-01-01

    In three years of NASA-sponsored research preceding this project, we successfully developed a technology for: (1) building qualitative and semi-quantitative models from libraries of model-fragments, (2) simulating these models to predict future behaviors with the guarantee that all possible behaviors are covered, (3) assimilating observations into behaviors, shrinking uncertainty so that incorrect models are eventually refuted and correct models make stronger predictions for the future. In our object-oriented framework, a tracker is an object which embodies the hypothesis that the available observation stream is consistent with a particular behavior of a particular model. The tracker maintains its own status (consistent, superceded, or refuted), and answers questions about its explanation for past observations and its predictions for the future. In the MIMIC approach to monitoring of continuous systems, a number of trackers are active in parallel, representing alternate hypotheses about the behavior of a system. This approach is motivated by the need to avoid 'system accidents' [Perrow, 1985] due to operator fixation on a single hypothesis, as for example at Three Mile Island. As we began to address these issues, we focused on three major research directions that we planned to pursue over a three-year project: (1) tractable qualitative simulation, (2) semiquantitative inference, and (3) tracking set management. Unfortunately, funding limitations made it impossible to continue past year one. Nonetheless, we made major progress in the first two of these areas. Progress in the third area as slower because the graduate student working on that aspect of the project decided to leave school and take a job in industry. I enclosed a set of abstract of selected papers on the work describe below. Several papers that draw on the research supported during this period appeared in print after the grant period ended.

  13. Monitoring

    DOEpatents

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

    2004-11-23

    The invention provides apparatus and methods which facilitate movement of an instrument relative to an item or location being monitored and/or the item or location relative to the instrument, whilst successfully excluding extraneous ions from the detection location. Thus, ions generated by emissions from the item or location can successfully be monitored during movement. The technique employs sealing to exclude such ions, for instance, through an electro-field which attracts and discharges the ions prior to their entering the detecting location and/or using a magnetic field configured to repel the ions away from the detecting location.

  14. NE Ohio Urban Growth Monitoring and Modeling Prototype. Revised

    NASA Technical Reports Server (NTRS)

    Siebert, Loren; Klosterman, Richard E.

    2001-01-01

    At the University of Akron, Dr. Loren Siebert, Dr. Richard Klosterman, and their graduate research assistants (Jung-Wook Kim, Mohammed Hoque, Aziza Parveen, and Ben Stabler) worked on the integration of remote sensing and GIs-based planning support systems. The primary goal of the project was to develop methods that use remote sensing land cover mapping and GIs-based modeling to monitor and project urban growth and farmland loss in northeast Ohio. Another research goal has been to use only GIS data that are accessible via the World Wide Web, to determine whether Ohio's small counties and townships that do not currently have parcel-level GIS systems can apply these techniques. The project was jointly funded by NASA and USGS OhioView grants during the 2000-2001 academic year; the work is now being continued under a USGS grant.

  15. Experimentally Derived Kinetic Model for Sensor-Based Gait Monitoring.

    PubMed

    Ketema, Yohannes; Gebre-Egziabher, Demoz

    2016-01-01

    A method for estimating gait parameters (shank, thigh, and stance leg angles) from a single, in situ, scalar acceleration measurement is presented. A method for minimizing the impact of errors due to unpredictable variations in muscle actuation and acceleration measurement biases is developed. This is done by determining the most probable gait progression by minimization of a cost function that reflects the size of errors in the gait parameters. In addition, a model for gait patterns that takes into account their variations due to walking speed is introduced and used. The approach is tested on data collected from subjects in a gait study. The approach can estimate limb angles with errors less than 6 deg (one standard deviation) and, thus, is suitable for many envisioned gait monitoring applications in nonlaboratory settings. PMID:26593150

  16. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    SciTech Connect

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim; Gilbert, Bob; Lake, Larry W.; Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett; Thomas, Sunil G.; Rightley, Michael J.; Rodriguez, Adolfo; Klie, Hector; Banchs, Rafael; Nunez, Emilio J.; Jablonowski, Chris

    2006-11-01

    survivability issues. Our findings indicate that packaging represents the most significant technical challenge associated with application of sensors in the downhole environment for long periods (5+ years) of time. These issues are described in detail within the report. The impact of successful reservoir monitoring programs and coincident improved reservoir management is measured by the production of additional oil and gas volumes from existing reservoirs, revitalization of nearly depleted reservoirs, possible re-establishment of already abandoned reservoirs, and improved economics for all cases. Smart Well monitoring provides the means to understand how a reservoir process is developing and to provide active reservoir management. At the same time it also provides data for developing high-fidelity simulation models. This work has been a joint effort with Sandia National Laboratories and UT-Austin's Bureau of Economic Geology, Department of Petroleum and Geosystems Engineering, and the Institute of Computational and Engineering Mathematics.

  17. Renal Artery Embolization Combined With Radiofrequency Ablation in a Porcine Kidney Model: Effect of Small and Narrowly Calibrated Microparticles as Embolization Material on Coagulation Diameter, Volume, and Shape

    SciTech Connect

    Sommer, C. M. Kortes, N.; Zelzer, S.; Arnegger, F. U.; Stampfl, U.; Bellemann, N.; Gehrig, T.; Nickel, F.; Kenngott, H. G.; Mogler, C.; Longerich, T.; Meinzer, H. P.; Richter, G. M.; Kauczor, H. U.; Radeleff, B. A.

    2011-02-15

    The purpose of this study was to evaluate the effect of renal artery embolization with small and narrowly calibrated microparticles on the coagulation diameter, volume, and shape of radiofrequency ablations (RFAs) in porcine kidneys. Forty-eight RFAs were performed in 24 kidneys of 12 pigs. In 6 animals, bilateral renal artery embolization was performed with small and narrowly calibrated microparticles. Upper and lower kidney poles were ablated with identical system parameters. Applying three-dimensional segmentation software, RFAs were segmented on registered 2 mm-thin macroscopic slices. Length, depth, width, volume{sub s}egmented, and volume{sub c}alculated were determined to describe the size of the RFAs. To evaluate the shape of the RFAs, depth-to-width ratio (perfect symmetry-to-lesion length was indicated by a ratio of 1), sphericity ratio (perfect sphere was indicated by a sphericity ratio of 1), eccentricity (perfect sphere was indicated by an eccentricity of 0), and circularity (perfect circle was indicated by a circularity of 1) were determined. Embolized compared with nonembolized RFAs showed significantly greater depth (23.4 {+-} 3.6 vs. 17.2 {+-} 1.8 mm; p < 0.001) and width (20.1 {+-} 2.9 vs. 12.6 {+-} 3.7 mm; p < 0.001); significantly larger volume{sub s}egmented (8.6 {+-} 3.2 vs. 3.0 {+-} 0.7 ml; p < 0.001) and volume{sub c}alculated (8.4 {+-} 3.0 ml vs. 3.3 {+-} 1.1 ml; p < 0.001); significantly lower depth-to-width (1.17 {+-} 0.10 vs. 1.48 {+-} 0.44; p < 0.05), sphericity (1.55 {+-} 0.44 vs. 1.96 {+-} 0.43; p < 0.01), and eccentricity (0.84 {+-} 0.61 vs. 1.73 {+-} 0.91; p < 0.01) ratios; and significantly greater circularity (0.62 {+-} 0.14 vs. 0.45 {+-} 0.16; p < 0.01). Renal artery embolization with small and narrowly calibrated microparticles affected the coagulation diameter, volume, and shape of RFAs in porcine kidneys. Embolized RFAs were significantly larger and more spherical compared with nonembolized RFAs.

  18. Monitored and modeled coral population dynamics and the refuge concept.

    PubMed

    Riegl, B; Purkis, S J; Keck, J; Rowlands, G P

    2009-01-01

    With large-scale impacts on coral reefs due to global climatic change projected to increase dramatically, and suitability of many areas for reef growth projected to decrease, the question arises whether particular settings might serve as refugia that can maintain higher coral populations than surrounding areas. We examine this hypothesis on a small, local scale in Honduras, western Caribbean. Dense coral thickets containing high numbers of the endangered coral Acropora cervicornis occur on offshore banks while being rare on the fringing reef on nearby Roatán. Geomorphological setting and community dynamics were evaluated and monitored from 1996 to 2005. A model of population dynamics was developed to test assumptions derived from monitoring. Coral cover on the fringing reef declined in 1998 from >30% to <20%, but the banks maintained areas of very dense coral cover (32% cover by A. cervicornis on the banks but <1% on the fringing reef). Bathymetry from satellite images showed the banks to be well-separated from the fringing reef, making asexual connectivity between banks and fringing reef impossible but protecting the banks from direct land-runoff during storms. Exposure to SE tradewinds also causes good flushing. Only four A. cervicornis recruits were recorded on the fringing reef over 6 years. Runoff associated with hurricanes caused greater mortality than did bleaching in 1998 and 2005 on the fringing reef, but not on the banks. Since 1870, our analysis suggests that corals on the banks may have been favored during 17 runoff events associated with tropical depressions and storms and potentially also during five bleaching events, but this is more uncertain. Our model suggests that under this disturbance regime, the banks will indeed maintain higher coral populations than the fringing reef and supports the assumption that offshore banks could serve as refugia with the capacity to subsidize depleted mainland populations. PMID:19100585

  19. [Research Advances in the Porcine Deltacoronavirus].

    PubMed

    Fang, Puxian; Fang, Liurong; Dong, Nan; Xiao, Shaobo

    2016-03-01

    The deltacoronavirus is a new member of the subfamily Coronaviridae of the family Coronaviridae. Deltacoronaviruses can infect birds and mammals. Deltacoronaviruses were detected in early 2007 in Asian leopard cats and Chinese ferret badgers. In 2014, porcine deltacoronavirus (PDCoV) infection spread rapidly in the USA. Moreover, cell culture-adapted PDCoV has been obtained from infected piglets. Animal experiments have confirmed that the isolated PDCoV is highly pathogenic and causes severe diarrhea in piglets. Thus, the PDCoV can be considered to be a good model to study the deltacoronavirus. In this review, we discuss the etiology, epidemiology, pathogenicity, culture, and diagnostic methods of the PDCoV. PMID:27396171

  20. Feature and Statistical Model Development in Structural Health Monitoring

    NASA Astrophysics Data System (ADS)

    Kim, Inho

    All structures suffer wear and tear because of impact, excessive load, fatigue, corrosion, etc. in addition to inherent defects during their manufacturing processes and their exposure to various environmental effects. These structural degradations are often imperceptible, but they can severely affect the structural performance of a component, thereby severely decreasing its service life. Although previous studies of Structural Health Monitoring (SHM) have revealed extensive prior knowledge on the parts of SHM processes, such as the operational evaluation, data processing, and feature extraction, few studies have been conducted from a systematical perspective, the statistical model development. The first part of this dissertation, the characteristics of inverse scattering problems, such as ill-posedness and nonlinearity, reviews ultrasonic guided wave-based structural health monitoring problems. The distinctive features and the selection of the domain analysis are investigated by analytically searching the conditions of the uniqueness solutions for ill-posedness and are validated experimentally. Based on the distinctive features, a novel wave packet tracing (WPT) method for damage localization and size quantification is presented. This method involves creating time-space representations of the guided Lamb waves (GLWs), collected at a series of locations, with a spatially dense distribution along paths at pre-selected angles with respect to the direction, normal to the direction of wave propagation. The fringe patterns due to wave dispersion, which depends on the phase velocity, are selected as the primary features that carry information, regarding the wave propagation and scattering. The following part of this dissertation presents a novel damage-localization framework, using a fully automated process. In order to construct the statistical model for autonomous damage localization deep-learning techniques, such as restricted Boltzmann machine and deep belief network

  1. Monitoring and modelling terbuthylazine and desethyl-terbuthylazine in groundwater.

    NASA Astrophysics Data System (ADS)

    Fait, G.; Balderacchi, M.; Ferrari, F.; Capri, E.; Trevisan, M.

    2009-04-01

    the future. Therefore, after the monitoring study the leaching of terbuthylazine and desethyl-terbuthylazine in groundwater was simulated with the aim to: 1) to verify a possible dilution effect due to lateral recharge; 2) to verify that the sampling time during the monitoring study was appropriate; 3) to verify the leaching of the metabolites in time. The model MACRO (version 5.1) was used. MACRO is a physically based one-dimensional model, which considers preferential flow (i.e. 'micropores' and 'macropores') to describe the transport of water and solutes in soils. Using the data coming from the monitoring (i.e.: soil, climatic, geology and hydrological data) a scenario was set in each of the eleven Italian sites monitored from 2005 to 2007. A maize monoculture was simulated for 20 years in each site, with a pre-emergence treatment every year. Daily measurements of groundwater table depth were available for each site, and then these data were used in order to reach a good calibration of the soil hydrology. Two sets of soil data were used: soil data acquired from the analysis of the soil core sampled in each site and soil data of the corresponding reference profile obtained from the regional soil maps. Furthermore, in order to estimate soil hydraulic parameters, two sets of pedotransfer functions were used: one developed for the northern Europe soils and one developed for the Po Valley soils. The results showed that the groundwater table depth simulated fitted quite well with the measured data, and then it was demonstrated that the groundwater recharge was constant in time. Only in one site measured and simulated groundwater table depth did not match to each other. This case suggested that hydrological equilibrium was not given only by precipitation/irrigation and evapotranspiration, then lateral or bottom recharge and a consequent dilution effect were assumed. Furthermore, in order to estimate the lateral recharge "Darcy's Law" was applied and it was demonstrated

  2. Perforation forces of the intact porcine anterior lens capsule.

    PubMed

    Ullrich, Franziska; Lussi, Jonas; Felekis, Dimitrios; Michels, Stephan; Petruska, Andrew J; Nelson, Bradley J

    2016-09-01

    During the first step of cataract surgery, the lens capsule is perforated and a circular hole is created with a sharp instrument, a procedure called capsulorhexis. To develop automated systems that can assist ophthalmologists during capsulorhexis, the forces required must be quantified. This study investigates perforation forces of the central anterior lens capsule in porcine eyes, which are used as a conservative model for the human eye. A micro-mechanical characterisation method is presented that measures capsular bag perforation forces with a high precision positioning and high-resolution force sensing system. The force during perforation of the anterior lens capsule was measured with various sized needles and indentation speeds and is found to be 15-35mN. A bio-mechanical model is identified that describes an exponential correlation between indentation force and depth, indicating strain hardening behaviour of the porcine anterior lens capsule. PMID:27254279

  3. A model for the dynamic nuclear/nucleolar/cytoplasmic trafficking of the porcine reproductive and respiratory syndrome virus (PRRSV) nucleocapsid protein based on live cell imaging.

    PubMed

    You, Jae-Hwan; Howell, Gareth; Pattnaik, Asit K; Osorio, Fernando A; Hiscox, Julian A

    2008-08-15

    Porcine reproductive and respiratory syndrome virus (PRRSV), an arterivirus, in common with many other positive strand RNA viruses, encodes a nucleocapsid (N) protein which can localise not only to the cytoplasm but also to the nucleolus in virus-infected cells and cells over-expressing N protein. The dynamic trafficking of positive strand RNA virus nucleocapsid proteins and PRRSV N protein in particular between the cytoplasm and nucleolus is unknown. In this study live imaging of permissive and non-permissive cell lines, in conjunction with photo-bleaching (FRAP and FLIP), was used to investigate the trafficking of fluorescent labeled (EGFP) PRRSV-N protein. The data indicated that EGFP-PRRSV-N protein was not permanently sequestered to the nucleolus and had equivalent mobility to cellular nucleolar proteins. Further the nuclear import of N protein appeared to occur faster than nuclear export, which may account for the observed relative distribution of N protein between the cytoplasm and the nucleolus. PMID:18550142

  4. 7 CFR 1230.18 - Porcine animal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Porcine animal. 1230.18 Section 1230.18 Agriculture... animal. Porcine animal means a swine, that is raised as (a) a feeder pig, that is, a young pig sold to another person to be finished for slaughtering over a period of more than 1 month; (b) for...

  5. 7 CFR 1230.18 - Porcine animal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Porcine animal. 1230.18 Section 1230.18 Agriculture... animal. Porcine animal means a swine, that is raised as (a) a feeder pig, that is, a young pig sold to another person to be finished for slaughtering over a period of more than 1 month; (b) for...

  6. 7 CFR 1230.18 - Porcine animal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Porcine animal. 1230.18 Section 1230.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... animal. Porcine animal means a swine, that is raised as (a) a feeder pig, that is, a young pig sold...

  7. 7 CFR 1230.18 - Porcine animal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Porcine animal. 1230.18 Section 1230.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... animal. Porcine animal means a swine, that is raised as (a) a feeder pig, that is, a young pig sold...

  8. 7 CFR 1230.18 - Porcine animal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Porcine animal. 1230.18 Section 1230.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... animal. Porcine animal means a swine, that is raised as (a) a feeder pig, that is, a young pig sold...

  9. Monitoring and modeling Hong Kong ionosphere using regional GPS networks

    NASA Astrophysics Data System (ADS)

    Gao, Shan

    The ionosphere is the region from 90 km to 2000 km altitude, where the solar radiation produces partially ionized plasma of different gas components. Knowledge of ionospheric electronic density and its variation is essential for a wide range of applications, such as radio and telecommunications, satellite tracking, earth observation from space, and satellite navigation. This research aims at monitoring detailed low latitude structures of the ionosphere using Hong Kong GPS network. In this study, the distribution characteristics of ionospheric TEC and disturbances are investigated and researched. It is shown that in Hong Kong, there is a two-dimensional peak along local solar time and latitude for the TEC distribution due to the solar radiation and equatorial ionospheric anomaly. The peak values appear around geographic latitude 22° north and the local solar time 2pm. On both sides of the peak, there exist large TEC slopes. Therefore, even with short baselines (i.e. <10 km), ionospheric delays cannot be eliminated by double difference technique. Ionospheric disturbances happen frequently in Hong Kong, with the severe ones mainly concentrating at geographic latitude 22° north and the local solar time 10pm. Both ionospheric TEC values and disturbances reach their seasonal maximum around the equinoxes. With the aids of PPP technique and satellite difference widelane technique, ionospheric modeling equation is reformed with less unknown parameters, which support the stable and precise estimation of ionospheric VTEC along with the constant biases within a short and peace period. On this basis, a new localized ionospheric modeling technique, which models ionospheric VTEC along the satellite track on the assumed ionospheric shell for each satellite with a short piecewise modeling period, is proposed for precise ionospheric TEC modeling, especially in low latitude regions where the ionosphere is active. The numerical results demonstrate that the new model has a several

  10. An ecohydraulic model to identify and monitor Moapa dace habitat.

    PubMed

    Hatten, James R; Batt, Thomas R; Scoppettone, Gary G; Dixon, Christopher J

    2013-01-01

    Moapa dace (Moapa coriacea) is a critically endangered thermophilic minnow native to the Muddy River ecosystem in southeastern Nevada, USA. Restricted to temperatures between 26.0 and 32.0 °C, these fish are constrained to the upper two km of the Muddy River and several small tributaries fed by warm springs. Habitat alterations, nonnative species invasion, and water withdrawals during the 20th century resulted in a drastic decline in the dace population and in 1979 the Moapa Valley National Wildlife Refuge (Refuge) was created to protect them. The goal of our study was to determine the potential effects of reduced surface flows that might result from groundwater pumping or water diversions on Moapa dace habitat inside the Refuge. We accomplished our goal in several steps. First, we conducted snorkel surveys to determine the locations of Moapa dace on three warm-spring tributaries of the Muddy River. Second, we conducted hydraulic simulations over a range of flows with a two-dimensional hydrodynamic model. Third, we developed a set of Moapa dace habitat models with logistic regression and a geographic information system. Fourth, we estimated Moapa dace habitat over a range of flows (plus or minus 30% of base flow). Our spatially explicit habitat models achieved classification accuracies between 85% and 91%, depending on the snorkel survey and creek. Water depth was the most significant covariate in our models, followed by substrate, Froude number, velocity, and water temperature. Hydraulic simulations showed 2-11% gains in dace habitat when flows were increased by 30%, and 8-32% losses when flows were reduced by 30%. To ensure the health and survival of Moapa dace and the Muddy River ecosystem, groundwater and surface-water withdrawals and diversions need to be carefully monitored, while fully implementing a proactive conservation strategy. PMID:23408999

  11. An ecohydraulic model to identify and monitor moapa dace habitat

    USGS Publications Warehouse

    Hatten, James R.; Batt, Thomas R.; Scoppettone, Gayton G.; Dixon, Christopher J.

    2013-01-01

    Moapa dace (Moapa coriacea) is a critically endangered thermophilic minnow native to the Muddy River ecosystem in southeastern Nevada, USA. Restricted to temperatures between 26.0 and 32.0°C, these fish are constrained to the upper two km of the Muddy River and several small tributaries fed by warm springs. Habitat alterations, nonnative species invasion, and water withdrawals during the 20th century resulted in a drastic decline in the dace population and in 1979 the Moapa Valley National Wildlife Refuge (Refuge) was created to protect them. The goal of our study was to determine the potential effects of reduced surface flows that might result from groundwater pumping or water diversions on Moapa dace habitat inside the Refuge. We accomplished our goal in several steps. First, we conducted snorkel surveys to determine the locations of Moapa dace on three warm-spring tributaries of the Muddy River. Second, we conducted hydraulic simulations over a range of flows with a two-dimensional hydrodynamic model. Third, we developed a set of Moapa dace habitat models with logistic regression and a geographic information system. Fourth, we estimated Moapa dace habitat over a range of flows (plus or minus 30% of base flow). Our spatially explicit habitat models achieved classification accuracies between 85% and 91%, depending on the snorkel survey and creek. Water depth was the most significant covariate in our models, followed by substrate, Froude number, velocity, and water temperature. Hydraulic simulations showed 2-11% gains in dace habitat when flows were increased by 30%, and 8-32% losses when flows were reduced by 30%. To ensure the health and survival of Moapa dace and the Muddy River ecosystem, groundwater and surface-water withdrawals and diversions need to be carefully monitored, while fully implementing a proactive conservation strategy.

  12. An Ecohydraulic Model to Identify and Monitor Moapa Dace Habitat

    PubMed Central

    Hatten, James R.; Batt, Thomas R.; Scoppettone, Gary G.; Dixon, Christopher J.

    2013-01-01

    Moapa dace (Moapa coriacea) is a critically endangered thermophilic minnow native to the Muddy River ecosystem in southeastern Nevada, USA. Restricted to temperatures between 26.0 and 32.0°C, these fish are constrained to the upper two km of the Muddy River and several small tributaries fed by warm springs. Habitat alterations, nonnative species invasion, and water withdrawals during the 20th century resulted in a drastic decline in the dace population and in 1979 the Moapa Valley National Wildlife Refuge (Refuge) was created to protect them. The goal of our study was to determine the potential effects of reduced surface flows that might result from groundwater pumping or water diversions on Moapa dace habitat inside the Refuge. We accomplished our goal in several steps. First, we conducted snorkel surveys to determine the locations of Moapa dace on three warm-spring tributaries of the Muddy River. Second, we conducted hydraulic simulations over a range of flows with a two-dimensional hydrodynamic model. Third, we developed a set of Moapa dace habitat models with logistic regression and a geographic information system. Fourth, we estimated Moapa dace habitat over a range of flows (plus or minus 30% of base flow). Our spatially explicit habitat models achieved classification accuracies between 85% and 91%, depending on the snorkel survey and creek. Water depth was the most significant covariate in our models, followed by substrate, Froude number, velocity, and water temperature. Hydraulic simulations showed 2–11% gains in dace habitat when flows were increased by 30%, and 8–32% losses when flows were reduced by 30%. To ensure the health and survival of Moapa dace and the Muddy River ecosystem, groundwater and surface-water withdrawals and diversions need to be carefully monitored, while fully implementing a proactive conservation strategy. PMID:23408999

  13. Caenorhabditis elegans: a model to monitor bacterial air quality

    PubMed Central

    2011-01-01

    Background Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards to chemicals and particles contrary to micro-organisms. Indeed, pertinent and reliable tests to evaluate this biohazard are scarce. In this work, our purpose was to evaluate the Caenorhaditis elegans killing test, a model considered as an equivalent to the mouse acute toxicity test in pharmaceutical industry, in order to monitor air bacterial quality. Findings The present study investigates the bacterial population in dust clouds generated during crop ship loading in harbor installations (Rouen harbor, Normandy, France). With a biocollector, airborne bacteria were impacted onto the surface of agar medium. After incubation, a replicate of the colonies on a fresh agar medium was done using a velvet. All the replicated colonies were pooled creating the "Total Air Sample". Meanwhile, all the colonies on the original plate were isolated. Among which, five representative bacterial strains were chosen. The virulence of these representatives was compared to that of the "Total Air Sample" using the Caenorhaditis elegans killing test. The survival kinetic of nematodes fed with the "Total Air Sample" is consistent with the kinetics obtained using the five different representatives strains. Conclusions Bacterial air quality can now be monitored in a one shot test using the Caenorhaditis elegans killing test. PMID:22099854

  14. Instrument Response Modeling and Simulation for the GLAST Burst Monitor

    SciTech Connect

    Kippen, R. M.; Hoover, A. S.; Wallace, M. S.; Pendleton, G. N.; Meegan, C. A.; Fishman, G. J.; Wilson-Hodge, C. A.; Kouveliotou, C.; Preece, R. D.; Connaughton, V.; Briggs, M. S.; Paciesas, W. S.; Bhat, P. N.

    2007-07-12

    The GLAST Burst Monitor (GBM) is designed to provide wide field of view observations of gamma-ray bursts and other fast transient sources in the energy range 10 keV to 30 MeV. The GBM is composed of several unshielded and uncollimated scintillation detectors (twelve NaI and two BGO) that are widely dispersed about the GLAST spacecraft. As a result, reconstructing source locations, energy spectra, and temporal properties from GBM data requires detailed knowledge of the detectors' response to both direct radiation as well as that scattered from the spacecraft and Earth's atmosphere. This full GBM instrument response will be captured in the form of a response function database that is derived from computer modeling and simulation. The simulation system is based on the GEANT4 Monte Carlo radiation transport simulation toolset, and is being extensively validated against calibrated experimental GBM data. We discuss the architecture of the GBM simulation and modeling system and describe how its products will be used for analysis of observed GBM data. Companion papers describe the status of validating the system.

  15. A model for monitoring of Hsp90-buffered genetic variations

    NASA Astrophysics Data System (ADS)

    Kozeko, Liudmyla

    Genetic material of terrestrial organisms can be considerably injured by cosmic rays and UV-radiation in the space environment. Organisms onboard are also exposed to the entire complex of negative physical factors which can generate genetic variations and affect morphogenesis. However, species phenotypes must be robust to genetic variation, requiring "buffering" systems to ensure normal development. The molecular chaperone Hsp90 can serve as such "a buffer". It is important in the maturation and conformational regulation of a diverse set of signal transducers. The requirement of many principal regulatory proteins for Hsp90 renders entire metabolic pathways sensitive to impairment of its function. So inhibition of Hsp90 function can open cryptic genetic variations and produce morphological changes. In this paper, we present a model for monitoring of cryptic Hsp90-buffered genetic variations arising during exposure to space and spaceflight factors. This model has been developed with Arabidopsis thaliana seeds gathered in natural habitats with high anthropogenic pressure and wild type (Col-0) seeds subjected to negative influences (UV, heavy metals) experimentally. The phenotypic traits of early seedlings grown under reduction of Hsp90 activity were characterized to estimate Hsp90-buffered genetic variations. Geldanamycin was used as an inhibitor of Hsp90 function.

  16. Regional Mapping, Modelling, and Monitoring of Tree Aboveground Biomass Carbon

    NASA Astrophysics Data System (ADS)

    Hudak, Andrew

    2016-04-01

    Airborne lidar collections are preferred for mapping aboveground biomass carbon (AGBC), while historical Landsat imagery are preferred for monitoring decadal scale forest cover change. Our modelling approach tracks AGBC change regionally using Landsat time series metrics; training areas are defined by airborne lidar extents within which AGBC is accurately mapped with high confidence. Geospatial topographic and climate layers are also included in the predictive model. Validation is accomplished using systematically sampled Forest Inventory and Analysis (FIA) plot data that have been independently collected, processed and summarized at the county level. Our goal is to demonstrate that spatially and temporally aggregated annual AGBC map predictions show no bias when compared to annual county-level summaries across the Northwest USA. A prominent source of bias is trees outside forest; much of the more arid portions of our study area meet the FIA definition of non-forest because the tree cover does not exceed their minimum tree cover threshold. We employ detailed tree cover maps derived from high-resolution aerial imagery to extend our AGBC predictions into non-forest areas. We also employ Landsat-derived annual disturbance maps into our mapped AGBC predictions prior to aggregation and validation.

  17. Pulsed ultrasound enhances the delivery of nitric oxide from bubble liposomes to ex vivo porcine carotid tissue

    PubMed Central

    Sutton, JT; Raymond, JL; Verleye, MC; Pyne-Geithman, GJ; Holland, CK

    2014-01-01

    Ultrasound-mediated drug delivery is a novel technique for enhancing the penetration of drugs into diseased tissue beds noninvasively. By encapsulating drugs into microsized and nanosized liposomes, the therapeutic can be shielded from degradation within the vasculature until delivery to a target site by ultrasound exposure. Traditional in vitro or ex vivo techniques to quantify this delivery profile include optical approaches, cell culture, and electrophysiology. Here, we demonstrate an approach to characterize the degree of nitric oxide (NO) delivery to porcine carotid tissue by direct measurement of ex vivo vascular tone. An ex vivo perfusion model was adapted to assess ultrasound-mediated delivery of NO. This potent vasodilator was coencapsulated with inert octafluoropropane gas to produce acoustically active bubble liposomes. Porcine carotid arteries were excised post mortem and mounted in a physiologic buffer solution. Vascular tone was assessed in real time by coupling the artery to an isometric force transducer. NO-loaded bubble liposomes were infused into the lumen of the artery, which was exposed to 1 MHz pulsed ultrasound at a peak-to-peak acoustic pressure amplitude of 0.34 MPa. Acoustic cavitation emissions were monitored passively. Changes in vascular tone were measured and compared with control and sham NO bubble liposome exposures. Our results demonstrate that ultrasound-triggered NO release from bubble liposomes induces potent vasorelaxation within porcine carotid arteries (maximal relaxation 31%±8%), which was significantly stronger than vasorelaxation due to NO release from bubble liposomes in the absence of ultrasound (maximal relaxation 7%±3%), and comparable with relaxation due to 12 μM sodium nitroprusside infusions (maximal relaxation 32%±3%). This approach is a valuable mechanistic tool for assessing the extent of drug release and delivery to the vasculature caused by ultrasound. PMID:25336947

  18. Applying model abstraction techniques to optimize monitoring networks for detecting subsurface contaminant transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving strategies for monitoring subsurface contaminant transport includes performance comparison of competing models, developed independently or obtained via model abstraction. Model comparison and parameter discrimination involve specific performance indicators selected to better understand s...

  19. Prospective Study in a Porcine Model of Sarcoptes scabiei Indicates the Association of Th2 and Th17 Pathways with the Clinical Severity of Scabies

    PubMed Central

    Mounsey, Kate E.; Murray, Hugh C.; Bielefeldt-Ohmann, Helle; Pasay, Cielo; Holt, Deborah C.; Currie, Bart J.; Walton, Shelley F.; McCarthy, James S.

    2015-01-01

    Background Understanding of scabies immunopathology has been hampered by the inability to undertake longitudinal studies in humans. Pigs are a useful animal model for scabies, and show clinical and immunologic changes similar to those in humans. Crusted scabies can be readily established in pigs by treatment with the glucocorticoid dexamethasone (Dex). Methodology/ Principal Findings Prospective study of 24 pigs in four groups: a) Scabies+/Dex+, b) Scabies+/Dex-, c) Scabies-/Dex+ and d) Scabies-/Dex-. Clinical symptoms were monitored. Histological profiling and transcriptional analysis of skin biopsies was undertaken to compare changes in cell infiltrates and representative cytokines. A range of clinical responses to Sarcoptes scabiei were observed in Dex treated and non-immunosuppressed pigs. An association was confirmed between disease severity and transcription of the Th2 cytokines IL-4 and IL-13, and up-regulation of the Th17 cytokines IL-17 and IL-23 in pigs with crusted scabies. Immunohistochemistry revealed marked infiltration of lymphocytes and mast cells, and strong staining for IL-17. Conclusions/ Significance While an allergic Th2 type response to scabies has been previously described, these results suggest that IL-17 related pathways may also contribute to immunopathology of crusted scabies. This may lead to new strategies to protect vulnerable subjects from contracting recurrent crusted scabies. PMID:25730203

  20. Modeling ultrasonic NDE and guided wave based structural health monitoring

    NASA Astrophysics Data System (ADS)

    Ravi, Nitin B.; Rathod, Vivek T.; Chakraborty, Nibir.; Mahapatra, D. R.; Sridaran, Ramanan; Boller, Christian

    2015-04-01

    Structural Health Monitoring (SHM) systems require integration of non-destructive technologies into structural design and operational processes. Modeling and simulation of complex NDE inspection processes are important aspects in the development and deployment of SHM technologies. Ray tracing techniques are vital simulation tools to visualize the wave path inside a material. These techniques also help in optimizing the location of transducers and their orientation with respect to the zone of interrogation. It helps in increasing the chances of detection and identification of a flaw in that zone. While current state-of-the-art techniques such as ray tracing based on geometric principle help in such visualization, other information such as signal losses due to spherical or cylindrical shape of wave front are rarely taken into consideration. The problem becomes a little more complicated in the case of dispersive guided wave propagation and near-field defect scattering. We review the existing models and tools to perform ultrasonic NDE simulation in structural components. As an initial step, we develop a ray-tracing approach, where phase and spectral information are preserved. This enables one to study wave scattering beyond simple time of flight calculation of rays. Challenges in terms of theory and modelling of defects of various kinds are discussed. Various additional considerations such as signal decay and physics of scattering are reviewed and challenges involved in realistic computational implementation are discussed. Potential application of this approach to SHM system design is highlighted and by applying this to complex structural components such as airframe structures, SHM is demonstrated to provide additional value in terms of lighter weight and/or longevity enhancement resulting from an extension of the damage tolerance design principle not compromising safety and reliability.

  1. Antibody recognition of porcine circovirus type 2 capsid protein epitopes after vaccination, infection, and disease.

    PubMed

    Trible, Benjamin R; Kerrigan, Maureen; Crossland, Nicholas; Potter, Megan; Faaberg, Kay; Hesse, Richard; Rowland, Raymond R R

    2011-05-01

    Open reading frame 2 (ORF2) of porcine circovirus type 2 (PCV2) codes for the 233-amino-acid capsid protein (CP). Baculovirus-based vaccines that express only ORF2 are protective against clinical disease following experimental challenge or natural infection. The goal of this study was to identify regions in CP preferentially recognized by sera from experimentally infected and vaccinated pigs and to compare these responses to those of pigs diagnosed with porcine circovirus-associated disease (PCVAD), including porcine multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). The approach was to react porcine sera with CP polypeptide fragments followed by finer mapping studies using overlapping oligopeptides that covered amino acids 141 to 200. The results showed that vaccinated pigs preferentially recognized only the largest polypeptide fragment, CP(43-233). A subset of experimentally infected pigs and pigs with PDNS showed strong reactivity against a CP oligopeptide, 169-STIDYFQPNNKR-180. Alanine scanning identified Y-173, F-174, Q-175, and K-179 as important for antibody recognition. The results from this study support the notion of PCV2 modulation of immunity, including antibody responses that may represent a precursor for disease. The recognition of CP(169-180) and other polypeptides provides opportunities to devise diagnostic tests for monitoring the immunological effectiveness of vaccination. PMID:21430122

  2. Enzymes enhance degradation of the fiber-starch-protein matrix of distillers dried grains with solubles as revealed by a porcine in vitro fermentation model and microscopy.

    PubMed

    Jha, R; Woyengo, T A; Li, J; Bedford, M R; Vasanthan, T; Zijlstra, R T

    2015-03-01

    Effects of treating corn and wheat distillers dried grains with solubles (DDGS) with a multicarbohydrase alone or in combination with a protease on porcine in vitro fermentation characteristics and the matrix structure of the DGGS before and after the fermentation were studied. Three DDGS samples (wheat DDGS sample 1 [wDDGS1], wheat DDGS sample 2 [wDDGS2], and corn DDGS [cDDGS]) were predigested with pepsin and pancreatin. Residues were then subjected to in vitro fermentation using buffered mineral solution inoculated with fresh pig feces without or with a multicarbohydrase alone or in combination with protease in a 3 × 3 factorial arrangement. Accumulated gas production was measured for up to 72 h. Concentration of VFA was measured in fermented solutions. The matrix of native DDGS and their residues after fermentation was analyzed using confocal laser scanning microscopy and scanning electron microscopy to determine internal and external structures, respectively. On a DM basis, wDDGS1, wDDGS2, and cDDGS contained 35.5, 43.4, and 29.0% CP; 2.23, 0.51, and 6.40% starch; 0.82, 0.80, and 0.89% available Lys; and 24.8, 22.5, and 23.0% total nonstarch polysaccharides, respectively. The in vitro digestibility of DM for wDDGS1, wDDGS2, and cDDGS was 67.7, 72.1, and 59.6%, respectively. The cDDGS had greater ( < 0.05) total gas and VFA production than both wheat DDGS. The wDDGS2 had lower ( < 0.05) total gas production than wDDGS1. Multicarbohydrase increased ( < 0.05) total gas production for cDDGS and total VFA production for wDGGS1 but did not increase gas or VFA production for wDDGS2. Addition of protease with multicarbohydrase to DDGS reduced ( < 0.05) total gas and VFA productions and increased ( < 0.05) branched-chain VFA regardless of DDGS type. Confocal laser scanning microscopy and scanning electron microscopy revealed that DDGS were mainly aggregates of resistant and nonfermentable starchy and nonstarchy complexes formed during DDGS production. After in vitro

  3. Porous Gelatin Particles for Uterine Artery Embolization: An Experimental Study of Intra-Arterial Distribution, Uterine Necrosis, and Inflammation in a Porcine Model

    SciTech Connect

    Sone, Miyuki; Osuga, Keigo; Shimazu, Kohki; Higashihara, Hiroki; Nakazawa, Tetsuro; Kato, Kenichi; Tomabechi, Makiko; Ehara, Shigeru; Nakamura, Hironobu; Morii, Eiichi; Aozasa, Katsuyuki

    2010-10-15

    PurposeWe evaluated the location of porous gelatin particles (GP; Gelpart; Nippon Kayaku/Astellas, Tokyo, Japan) within the arterial vasculature and their acute effects on uterine necrosis and inflammation after uterine artery embolization (UAE) in swine.Materials and MethodsAdult nonpregnant pigs (n = 6) were allocated to either 1- (n = 3) or 2-mm GP (n = 3). Superselective and bilateral embolization of the uterine arteries was performed. All animals were killed 1 week after UAE. Macroscopic and microscopic findings, including the level of arterial occlusion and their effect on uterine necrosis and inflammation, were analyzed.ResultsAll UAE procedures were completed without severe complications. The macroscopic necrosis was seen in two animals in the 2-mm group with an extent of <50%. The location of the occluded arteries did not differ significantly between groups. The median diameters of the occluded arteries were 449 {mu}m (95% confidence interval [CI] 417-538 {mu}m) in the 1-mm GP group and 484 {mu}m (95% CI 370-560 {mu}m) in the 2-mm GP group. As for microscopic necrosis, no statistically significant difference was observed. The qualitative inflammatory reaction was significantly greater in the 2-mm GP group than in the 1-mm group (p < 0.001).ConclusionsBoth 1- and 2-mm GP occluded the arteries relevant to the target diameter for UAE in porcine uterus, presumably due to the plastic deformity. Both sizes of GP were associated with limited areas of necrosis; however, evaluation of inflammatory reaction was preliminary. Further study with adequate evaluation of inflammatory reactions is suggested.

  4. What Kind of Capsule Endoscope Is Suitable for a Controllable Self-Propelling Capsule Endoscope? Experimental Study Using a Porcine Stomach Model for Clinical Application (with Videos)

    PubMed Central

    Ota, Kazuhiro; Nouda, Sadaharu; Takeuchi, Toshihisa; Iguchi, Munetaka; Kojima, Yuichi; Kuramoto, Takanori; Inoue, Takuya; Shindo, Yasunori; Uesugi, Kenshiro; Fujito, Yoshiaki; Nishihara, Hironori; Ohtsuka, Naotake; Higuchi, Kazuhide

    2015-01-01

    Background We have been developing the Self-Propelling Capsule Endoscope (SPCE) that allows for controllability from outside of the body and real-time observation. What kind of capsule endoscope (CE) is suitable for a controllable SPCE is unclear and a very critical point for clinical application. We compared observing ability of three kinds of SPCEs with different viewing angles and frame rates. Methods Eleven buttons were sewed in an excised porcine stomach. Four examiners controlled the SPCE using PillCamSB2, -ESO2, and -COLON2 (Given Imaging Ltd., Israel), for 10 minutes each with the aim of detecting as many buttons and examining them as closely as possible. The ability to find lesions was assessed based on the number of detected buttons. The SPCE-performance score (SPS) was used to evaluate the ability to examine the lesions in detail. Results The SPCE-ESO2, -COLON2, and -SB2 detected 11 [interquartile range (IQR): 0], 10.5 (IQR, 0.5), and 8 (IQR, 1.0) buttons, respectively. The SPCE-ESO2 and -COLON2 had a significantly better ability to detect lesions than the -SB2 (p < 0.05). The SPCE-ESO2, -COLON2, and -SB2 had significantly different SPS values of 22 (IQR, 0), 16.5 (IQR, 1.5), and 14 (IQR, 1.0), respectively (p < 0.05 for all comparisons; SPCE-SB2 vs. -ESO2, -SB2 vs. -COLON2, and -ESO2 vs. -COLON2). Conclusions PillCamESO2 is most suitable in different three CEs for SPCE for examining lesions in detail of the stomach. PMID:26447694

  5. Characterization of a Pathogenic Full-Length cDNA Clone and Transmission Model for Porcine Epidemic Diarrhea Virus Strain PC22A

    PubMed Central

    Beall, Anne; Yount, Boyd; Lin, Chun-Ming; Hou, Yixuan; Wang, Qiuhong; Saif, Linda

    2016-01-01

    ABSTRACT Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic alphacoronavirus. In the United States, highly virulent PEDV strains cause between 80 and 100% mortality in suckling piglets and are rapidly transmitted between animals and farms. To study the genetic factors that regulate pathogenesis and transmission, we developed a molecular clone of PEDV strain PC22A. The infectious-clone-derived PEDV (icPEDV) replicated as efficiently as the parental virus in cell culture and in pigs, resulting in lethal disease in vivo. Importantly, recombinant PEDV was rapidly transmitted to uninoculated pigs via indirect contact, demonstrating virulence and efficient transmission while replicating phenotypes seen in the wild-type virus. Using reverse genetics, we removed open reading frame 3 (ORF3) and replaced this region with a red fluorescent protein (RFP) gene to generate icPEDV-ΔORF3-RFP. icPEDV-ΔORF3-RFP replicated efficiently in vitro and in vivo, was efficiently transmitted among pigs, and produced lethal disease outcomes. However, the diarrheic scores in icPEDV-ΔORF3-RFP-infected pigs were lower than those in wild-type-virus- or icPEDV-infected pigs, and the virus formed smaller plaques than those of PC22A. Together, these data describe the development of a robust reverse-genetics platform for identifying genetic factors that regulate pathogenic outcomes and transmission efficiency in vivo, providing key infrastructural developments for developing and evaluating the efficacy of live attenuated vaccines and therapeutics in a clinical setting. PMID:26733065

  6. Optofluidic phantom mimicking optical properties of porcine livers

    PubMed Central

    Long, Ruiqi; King, Travis; Akl, Tony; Ericson, M. Nance; Wilson, Mark; Coté, Gerard L.; McShane, Michael J.

    2011-01-01

    One strategy for assessing efficacy of a liver transplant is to monitor perfusion and oxygenation after transplantation. An implantable optical sensor is being developed to overcome inadequacies of current monitoring approaches. To facilitate sensor design while minimizing animal use, a polydimethylsiloxane (PDMS)-based liver phantom was developed to mimic the optical properties of porcine liver in the 630-1000 nm wavelength range and the anatomical geometry of liver parenchyma. Using soft lithography to construct microfluidic channels in pigmented elastomer enabled the 2D approximation of hexagonal liver lobules with 15mm sinusoidal channels, which will allow perfusion with blood-mimicking fluids to facilitate the development of the liver perfusion and oxygenation monitoring system. PMID:21750766

  7. Hydrological modelling of slopes from field monitoring data

    NASA Astrophysics Data System (ADS)

    Comegna, Luca; Damiano, Emilia; Greco, Roberto; Guida, Andrea; Olivares, Lucio; Picarelli, Luciano

    2013-04-01

    A simplified hydrological model of a steep slope covered with loose granular pyroclastic deposits is presented. The slope is located in the mountains northern of Naples, and the soil cover, constituted by layers of loose volcanic ashes and pumices with a total thickness of 2.5m, lays upon a fractured limestone bedrock. At the interface between the bedrock and the soil cover, a layer of weathered ashes, with significant clay fraction, is sometimes observed. The slope has a fairly regular inclination of 40°, and is covered by chestnut woods and thick brushwood growing in late spring. The inclination of the slope is comparable with the internal friction angle of the ashes, thus the equilibrium is possible thanks to the contribution offered to the shear strength by the soil suction in unsaturated conditions. Indeed, in December 1999, a landslide was triggered by prolonged and intense precipitations. As it frequently happens with similar pyroclastic covers, the triggered slide exhibited a flow-like behavior, covering 2km in few minutes, heavily hitting the nearby town of Cervinara (AV). Since then, the slope has been constantly monitored, and during the last two years an automated station with seven TDR probes for the measurement of soil water content, eight tensiometers for the measurement of soil suction, and a rain gauge, has been operating. The data, collected every two hours, allowed getting more insight of the hydrological behavior of the slope and building up an effective hydrological model. In the model, the layered soil profile has been replaced with a single homogeneous layer, with water retention curve estimated by coupling the values of