Landrace Swine Research Articles

Measurement of the Luminal Diameter of Peripheral Arterial Vasculature in Yorkshire × Landrace Swine by Using Ultrasonography and Angiography.

To select animals of appropriate size for preclinical studies of cardiovascular devices, reference knowledge of the cardio- vascular anatomy relative to body weight is crucial. We measured the luminal diameters of the arteries (carotid, femoral, and iliac arteries) that are the common access vessels for endovascular and vascular procedures in Yorkshire × Landrace swine. Measurements were performed by using both ultrasound and angiographic methods and were correlated with body weight. Results showed no statistically significant difference between the left and right vessels in the diameters of the carotid, femoral, and iliac arteries. The diameters of the measured arteries showed high correlation with animal weight in pigs that weighed less than 70 kg.

Efficacy of venous recanalization by non-invasive pulsed ultrasonic cavitation therapy on swine model of acute deep venous thrombosis with 14 days of follow-up

Post thrombotic syndrome is a frequent complication of deep venous thrombosis, associated with high morbidity. Treatments currently available are invasive. Pulsed cavitational ultrasound therapy (PCUT) is a new technique to destroy remotely soft tissue. We demonstrated that PCUT was able to recanalize non-invasively in in-vitro model of human blood clot. We aim to test the safety and efficacy of venous recanalization by non-invasive PCUT in vivo swine model of acute venous thrombosis. All the experiments were performed on White large X Landrace swine. We induced an acute femoral deep venous thrombosis by using endovascular approach combined with local injection of thrombin. A 3 cm length occlusive thrombosis was obtained after 2 hours. Swine were divided in three groups: one with PCUT without follow-up ( n = 11), one with PCUT and follow-up at 14 days ( n = 8), and a control group also followed for 14 days ( n = 5). Acutely and during follow up all swine received curative anticoagulation. To achieve PCUT, a 2.25 MHz transducer (Imasonic©) centered by a linear probe was used and cavitation was obtained in the centre of the vein. Effectiveness of recanalization was evaluated by echo-Doppler and phlebography. Safety was assessed by Doppler ultrasound and by histological analysis of vein, artery and lungs. Among the 24 swine, we obtained 22 occlusive venous thromboses and 2 partials. The median length of the thrombus was 26 ± 4.4 mm. Acutely, thrombosis recanalization was obtained among the 19 swine with PCUT with median treatment duration of 33 min. After a 14-day follow-up, 75% of recanalisation remains permeable vs. 0% of vein permeable in the no therapy group ( P = 0.008). Residual diameter was 2.6 ± 1.2 mm, 50% of the venous diameter. No embolism or pulmonary infarction was observed in all pigs ( Fig. 1 ). We have demonstrated in vivo the safety and the efficacy of PCUT for non-invasive venous recanalization, persistent after 2 weeks.

Cardiovascular magnetic resonance-derived left ventricular mechanics\u2014strain, cardiac power and end-systolic elastance under various inotropic states in swine

BackgroundCardiovascular magnetic resonance (CMR) strain imaging is an established technique to quantify myocardial deformation. However, to what extent left ventricular (LV) systolic strain, and therefore LV mechanics, reflects classical hemodynamic parameters under various inotropic states is still not completely clear. Therefore, the aim of this study was to investigate the correlation of LV global strain parameters measured via CMR feature tracking (CMR-FT, based on conventional cine balanced steady state free precession (bSSFP) images) with hemodynamic parameters such as cardiac index (CI), cardiac power output (CPO) and end-systolic elastance (Ees) under various inotropic states.Methods Ten anaesthetized, healthy Landrace swine were acutely instrumented closed-chest and transported to the CMR facility for measurements. After baseline measurements, two steps were performed: (1) dobutamine-stress (Dobutamine) and (2) verapamil-induced cardiovascular depression (Verapamil). During each protocol, CMR images were acquired in the short axisand apical 2Ch, 3Ch and 4Ch views. MEDIS software was utilized to analyze global longitudinal (GLS), global circumferential (GCS), and global radial strain (GRS).ResultsDobutamine significantly increased heart rate, CI, CPO and Ees, while Verapamil decreased them. Absolute values of GLS, GCS and GRS accordingly increased during Dobutamine infusion, while GLS and GCS decreased during Verapamil. Linear regression analysis showed a moderate correlation between GLS, GCS and LV hemodynamic parameters, while GRS correlated poorly. Indexing global strain parameters for indirect measures of afterload, such as mean aortic pressure or wall stress, significantly improved these correlations, with GLS indexed for wall stress reflecting LV contractility as the clinically widespread LV ejection fraction.ConclusionGLS and GCS correlate accordingly with LV hemodynamics under various inotropic states in swine. Indexing strain parameters for indirect measures of afterload substantially improves this correlation, with GLS being as good as LV ejection fraction in reflecting LV contractility. CMR-FT-strain imaging may be a quick and promising tool to characterize LV hemodynamics in patients with varying degrees of LV dysfunction.

P2765Efficacy of venous recanalization by noninvasive pulsed cavitational ultrasound therapy on swine model of acute deep venous thrombosis

Abstract Background Post thrombotic syndrome is a frequent complication of deep venous thrombosis and is associated with high morbidity and hospitalization. Treatments currently available are invasive, involve use of endovenous procedures with stents and balloons, and frequently require general anesthesia. Pulsed cavitational ultrasound therapy (PCUT) emerged recently as a new technique to destroy remotely soft tissue. We recently demonstrated that PCUT was able to recanalize non-invasively in in vitro model of acute venous thrombosis (human blood clot). Purpose We aim to test the safety and efficacy of venous recanalization by noninvasive PCUT in vivo swine model of acute venous thrombosis. Methods All the experiments were performed on White large X Landrace swine. We induced an acute femoral deep venous thrombosis by using occlusive balloons introduced from jugular and popliteal vein combined with local injection of 50 IU of human thrombin. A 3 cm length occlusive thrombosis was obtained after 2 hours. Swines were divided in three groups: one with PCUT without follow-up (n=11), one with PCUT and follow-up at 14 days (n=8), and a control group also followed for 14 days (n=5). Acutely and during the follow up all swines received curative anticoagulation. To achieve PCUT, a 2.25 MHz transducer centered by a linear probe was used and cavitation was obtained in the center of the vein (Figure). After manual determination of thrombus location, a robotic arm was used to automatically move the transducer along the thrombus. Effectiveness of recanalization was evaluated by echo-Doppler and phlebography. Safety was assessed by Doppler ultrasound of the insonified area (artery, veins and surrounding tissue) and by histological analysis (local femoral vein and artery and lungs for pulmonary embolism). Results Among the 24 swines, we obtained 22 occlusive venous thromboses and 2 partial. The median length of the thrombus was 26±4.4 mm with vein diameter of 8.5±1.6 mm. Acutely, thrombosis recanalization was systematically obtained among the 19 swine with PCUT with median treatment duration of 33 minutes with residual diameter of 2.9±0.9 mm. No extravasation of contrast material or hematoma was observed after the therapy. After a 14-day follow-up, 75% of recanalisation remain permeable vs. 0% of vein permeable in the no therapy group (p=0.008). Residual diameter was 2.6±1.2 mm, which correspond to 50% of the venous diameter. No vein or artery damage and no embolism or pulmonary infarction was observed in all pigs. Figure 1 Conclusion We have demonstrated in vivo the safety and the efficacy of PCUT for non-invasive venous recanalization, persistent after 2 weeks. Acknowledgement/Funding French society of cardiology

EFEKTIVITAS PENAMBAHAN EKSTRAK MESOCARP Borassus flabellifer PADA PENGENCER BELTSVILLE THAWING SOLUTION TERHADAP VIABILITAS SPERMATOZOA ASAL KAUDA EPIDIDIMIS BABI

This study aimed to determine the effectiveness of adding various concentrations of palm fruit mesocarp (Borassus flabellifer) extract to Beltsville Thawing Solution (BTS) diluents on the viability of swines cauda epididymis spermatozoa at 13°C for 4 days. During the storage period, the metabolic activity of spermatozoa will produce free radicals which can reduce spematozoa viability. Borassus flabellifer mesocarp extract contains antioxidants that can counteract free radicals. Testicular and epididymal samples from the 3-4 years old Duroc Landrace Swine Crossbreed. Swine cauda epididymis were obtained from the Oeba Abattoir, Kupang. Cauda epididymis spermatozoa were collected using a combination of incision, rinsing and suppression methods then collected and diluted using BTS and divided into four groups to be given various concentrations of Borassus flabellifer mesocarp extract (K0: without extract; K1: 0.01%; K2: 0.03%; and K3: 0.05 %) and preserved at 13°C for 4 days. Evaluation of spermatozoa viability was carried out microscopically. The results of cauda epididymis sperm viability were K0 = 43.57%; K1 = 54.81%; K2 = 50.52%; and K3 = 49.95%. Analysis of variance showed that the addition Borassus flabellifer mesocarp extract gave a significant difference (P> 0.05) to spermatozoa viability. The Duncan region test showed a significant difference (P <0.05) between treatment K1 with treatments K0, K2 and K3 on the viability of spermatozoa. The conclusions of this study was the addition of Borassus flabellifer mesocarp extract at 0.01% concentration was the most appropriate dose to maintain the viability of swine cauda epididymis spermatozoa. Keywords: Borassus flabellifer, Cauda Epididymal, Mesocarp Extract, Spermatozoa, Swine.

Serial Optical Coherence Tomography at Baseline, 7 Days, and 1, 3, 6 and 12 Months After Bioresorbable Scaffold Implantation in a Growing Porcine Model

Little is known about serial changes in lumen and device dimensions after bioresorbable scaffold implantation in a growing animal model. Methods and Results: ABSORB (n=14) or bare metal stents (ICROS amg [Abbott Vascular, Santa Clara, CA, USA], Winsen-Luhe, Germany; n=15) were implanted in the coronary arteries of domestic swine (a hybrid of Finnish-Norwegian Landrace swine) weighing 30-35 kg. Angiography and optical coherence tomography (OCT) were performed immediately after implantation and repeated at 7 days, 1, 3, 6 and 12 months after the index procedure. One month after implantation, mean lumen area decreased relative to baseline in both groups (relative area change from baseline, -41.4±15.6% for ABSORB vs. -20.9±18.6% for ICROS) while mean device area decreased only in the ABSORB group (relative area change: -11.1±9.4% vs. +0.14±7.95%, respectively). At 12 months, mean lumen area increased relative to baseline in both groups (relative area change from baseline, +55.6±22.4% vs. +32.3±83.6%, respectively) in accordance with the swine growth weighing up to 260-300 kg. Mean device area in the ICROS group remained stable whereas that in the ABSORB group began to increase between 3 and 6 months along with the vessel growth (relative area change: +107.8±25.7% vs. +0.14±7.95%). In the growing porcine model, ABSORB was associated with greater extent of recoil 1 month after implantation compared with ICROS but demonstrated substantial adaptability to vessel growth in late phase.

Ossabaw Pigs With a PCSK9 Gain-of-Function Mutation Develop Accelerated Coronary Atherosclerotic Lesions: A Novel Model for Preclinical Studies.

BackgroundOssabaw pigs are unique miniature swine with genetic predisposition to develop metabolic syndrome and coronary atherosclerosis after extended periods receiving atherogenic diets. We have hypothesized that transgenic Ossabaw swine expressing chimp PCSK9 (proprotein convertase subtilisin‐like/kexin type 9) containing the D374Y gain of function would develop familial hypercholesterolemia and coronary artery plaques more rapidly than Landrace swine with the same transgene.Methods and ResultsOssabaw and Landrace PCSK9 gain‐of‐function founders were generated by Sleeping Beauty transposition and cloning. Histopathologic findings in the Ossabaw founder animal showed more advanced plaques and higher stenosis than in the Landrace founder, underscoring the Ossabaw genetic predisposition to atherosclerosis. We chose to further characterize the Ossabaw PCSK9 gain‐of‐function animals receiving standard or atherogenic diets in a 6‐month longitudinal study using computed tomography, magnetic resonance (MR) imaging, intravascular ultrasound, and optical coherence tomography, followed by pathological analysis of atherosclerosis focused on the coronary arteries. The Ossabaw model was consistently hypercholesterolemic, with or without dietary challenge, and by 6 months had consistent and diffuse fibrofatty or fibroatheromatous plaques with necrosis, overlying fibrous caps, and calcification in up to 10% of coronary plaques.ConclusionsThe Ossabaw PCSK9 gain‐of‐function model provides consistent and robust disease development in a time frame that is practical for use in preclinical therapeutic evaluation to drive innovation. Although no animal model perfectly mimics the human condition, this genetic large‐animal model is a novel tool for testing therapeutic interventions in the context of developing and advanced coronary artery disease.

Model of Short Bowel Syndrome and Segmental Intestinal Autotransplantation in Swine

Introduction: Intestinal transplantation using living-related donors could minimize the shortage of donor grafts. Nevertheless, the number of living donor small bowel transplantation in the clinical practice is small, probably due to lack of experimental models of this procedure. Objective: To describe a swine model of segmental intestinal autotransplantation producing short bowel syndrome and simulating living donor transplantation, based in our previous technique of liver autotransplantation1. Methods: Six males Landrace swine weighting 25 to 40 Kg were used. A midline incision with the exposition of the entire small bowel was performed (figure 1). The middle part of the mesenteric artery and vein were dissected to identify the pedicle (figures 2 and 3) from a segment in the middle of the small bowel with approximately 300 centimeters length that represents about 1/7 of the swine’s entire small bowel. These mesenteric artery and vein branches were sectioned near the main mesenteric artery and vein (figures 3 and 4). The graft was flashed with cold lactate ringer by the arterial branch (5). The remaining small bowel was removed from the proximal jejune to the distal ileum. A segment of the infrarenal aorta and inferior vena cava was dissected, cross clamped and anastomosed to the mesenteric artery and vein branches (figure 6). Following reperfusion, ileum and jejune anastomoses were performed. The grafts were monitored macroscopically. Animal were sacrificed after two hours of the reperfusion and samples from the graft were removed for histological analysis. Results: All animals survived until the end of the experiment. After reperfusion all grafts rapidly turned in a normal color (figure 7) and no major anastomosis complications were observed. The median period of total operation time, graft cold ischemia and vascular anastomosis were 104, 52 and 33 minutes respectively. The histological analysis observed mild reperfusion injury in two cases and normal in the other grafts. Conclusion: This model of segmental intestinal transplantation is feasible and simulates short bowel syndrome and living donation transplantation. This model is cheaper than allotransplantation and optimal for intestinal transplantation training and to study segmental intestinal graft physiology.Figure

Assessment of M. longissimus fibre types and metabolic enzymes in Bama miniature pigs and Landrace swine

Overt differences exist between Chinese local pigs and exotic pig breeds, especially in muscle growth rate and meat quality. However, the underlying molecular mechanisms remain unclear. This study aimed to assess muscle fibre types and metabolic enzymes in Bama miniature pigs and Landrace swine. Meat quality traits, including intramuscular fat content, and muscle colour, conductivity, and tenderness, were assessed in these pig breeds. Then, muscle fibre types were classified, and mRNA amounts and activities of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) assessed, in M. longissimus from the two pig breeds, at various ages. Our data showed significantly higher back fat thickness, muscle conductivity, and intramuscular fat content in samples from Bama miniature pigs compared with the values obtained for Landrace pigs (p < .05). In addition, SDH activity was significantly higher, and LDH activity overtly lower in Bama pigs compared with Landrace swine (p < .05). Furthermore, myosin heavy-chain (MyHC) II A, II B, and II X mRNA levels in Bama miniature pigs at 180 were significantly higher than values obtained for Landrace pigs of the same age. Although MyHC I gene expression levels were similar in Bama miniature and Landrace pigs at 180 days of age, significantly higher amounts were obtained in 300 day old Bama miniature pigs compared with 180 day old Landrace pigs (p < .05). Collectively, these preliminary findings indicated that skeletal muscles from Bama miniature pigs may contain more oxidative fibres compared with those from Landrace pigs, which might explain the meat quality differences between the two pig breeds.

Splenectomy Versus Sham Splenectomy in a Swine Model of Controlled Hemorrhagic Shock.

Splenectomy is controversial in acute hemorrhagic shock models. To compare splenectomized (SP) versus sham-splenectomized (SSP) swine during acute controlled hemorrhage. Twenty-six male Landrace White swine (mean body weight ± standard deviation, 33.8 ± 2.9 kg) were used. Ethics approval was obtained. Landrace swine underwent splenectomy (n = 13) or sham-splenectomy (n = 13), were bled to mean arterial blood pressure (MAP) of 40 mm Hg, which was held for 60 min, given 125 mL IV RescueFlow, held for a further 60 min, given whole blood, and held for a final 60 min. Tissue oxygen saturation, thromboelastography, oncotic pressure, urine volume and specific gravity, complete blood count, serum chemistry, body temperature, hematocrit, total solids, arterial and mixed venous blood gas, bispectral index, SAP, MAP, DAP, cardiac index, total blood volume (TBV) removed and returned, rate of hemorrhage and transfusion, spleen weight, heart rate (HR), arterial pH, lactate, PaO2, PaCO2, respiratory rate, cranial mesenteric and renal artery blood flow were recorded. Groups were compared using two-way ANOVA with post hoc Bonferroni (P < 0.05) for repeated measures or t test for non-repeated measures. Compared with the SSP swine, SP swine had higher HR post-splenectomy for the duration of the experiment (P < 0.03), and higher hematocrits at 15 and 60 min post splenectomy (P < 0.01, P < 0.001, respectively). SSP swine had greater TBV removed during hemorrhage (P < 0.01); however, when blood loss based on splenic weight was considered, TBV removed was similar between groups. Splenectomy likely accounts for the transient increase in hematocrit and the higher HR in SP swine prior to hemorrhage, and the differences in TBV removed between the two groups during hemorrhage. With a fixed end point model using a moderate rate of acute hemorrhage and an MAP of 40 mm Hg, splenectomy is not necessary and may confound results.

Genetic parameters and trends for production and reproduction traits of a Landrace herd in China

The objectives of this study were to estimate the genetic parameters and the breeding progress in a Landrace herd in China, and to predict the potential benefits by applying new breeding technology. Hereby, the performance records from a Landrace swine herd in China, composing over 33 000 pigs born between 2001 and 2013, were collected on six economically important traits, i.e., average daily gain between 30–100 kg (ADG), adjusted backfat thickness at 100 kg (BF), adjusted days to 30 kg (D30), adjusted days to 100 kg (D100), number born alive (NBA), and total number born (TNB). The genetic parameters were estimated by restricted maximum likelihood via DMU, and realized genetic trends were analyzed. Based on the real population structure and genetic parameters obtained from this herd, the potential genetic trends by applying genomic selection (GS) were predicted via a computer simulation study. Results showed that the heritability estimates in this Landrace herd were 0.55 (0.02), 0.42 (0.01), and 0.12 (0.01), for BF, D100, and TNB, respectively. Favorable genetic trends were obtained for D100, BF, and TNB due to direct selection, for ADG and NBA due to indirect selection. Long-term selection against D100 did not improve D30, though they are highly genetically correlated (0.64). Appling GS in such a swine herd, the genetic gain can be increased by 25%, or even larger for traits with low heritability or individuals without phenotypes before selection. It can be concluded that conventional breeding strategy was effective in the herd studied, while applying GS is promising and hence the road ahead in swine breeding.

UM206, a Peptide Fragment of Wnt5a, Attenuates Adverse Remodeling after Myocardial Infarction in Swine

IntroductionFollowing myocardial infarction (MI), left ventricular (LV) remodeling aims to maintain cardiac function. Nevertheless, adverse remodeling results in thinning of the infarct and LV dilation which may subsequently lead to the development of heart failure (HF) with poor prognosis. Wnt/Frizzled signaling plays a key role in cardiac remodeling following MI. We have shown previously that blockade of Wnt/Frizzled signaling with UM206 suppresses adverse remodeling and prevents HF development in mice post‐MI. Here we investigated the effects of UM206 therapy in a clinically relevant large animal model.MethodsTwelve Yorkshire x Landrace swine were subjected to 2h of myocardial ischemia by ligation of the proximal left circumflex artery, followed by reperfusion. Starting 24h post‐MI, 6 animals were treated with UM206 (0.6 μg/kg/day i.v.) for 5 weeks. The 6 control swine were treated with vehicle. Cardiac dimensions and infarct mass (IM) were determined by echocardiography and dedicated markers, respectively.ResultsTreatment with UM206 for 5 weeks resulted in a significant decrease in IM compared to baseline, whereas IM remained unaffected in the control group. This was accompanied by progressive dilation of the LV in the control group between 3 and 5 weeks after MI while adverse remodeling was halted in the UM206 treated group.ConclusionUM206 treatment in a clinically relevant swine model of reperfused myocardial infarction attenuates adverse remodeling.Supported by the Dutch Heart Foundation (2010B196)

Chemical renal denervation by vincristine: the role of the flow rate of delivery.

Vincristine has been proven promising regarding its safety and efficacy for the renal artery denervation both in experimental models and in humans. The aim of the study was to compare in an experimental model the efficacy of constant versus random flow rate delivery of vincristine on renal sympathetic denervation. We used 10 juvenile Landrace swine. After the introduction of a 7F sheath into the femoral artery, a guide wire was advanced into the distal part of the renal artery. Then the first delivery balloon catheter, which delivers vincristine in random flow rate, was advanced at the proximal part of the artery, and the balloon was inflated in order to locally deliver vincristine to the media of the renal artery. The process was repeated in the contralateral renal artery, with the use of the double balloon catheter that delivers vincristine with a constant flow rate. Euthanasia of the animals was performed at 28 days. All sections were processed for histological and immunohistochemical analysis. The delivery of vincristine with both catheters was successful and uncomplicated. Immunohistochemistry showed that the mean number of intact nerves in all sections was significantly lower in the group of vincristine delivered with constant flow catheter compared to the group that the delivery was performed in a random fashion. (1.48 ± 0.37 vs. 1.70 ± 0.41, p = 0.04). Chemical renal denervation with vincristine by a constant flow rate catheter is more effective compared to the denervation performed by a catheter that delivers vincristine in a random fashion.

Cardiopulmonary Bypass Is Associated With Altered Vascular Reactivity of Isolated Pulmonary Artery in a Porcine Model: Therapeutic Potential of Inhaled Tezosentan

Whereas it is established that endothelin-1 elicits sustained deleterious effects on the cardiovascular system during cardiopulmonary bypass (CPB), presently it remains unknown whether the inhaled administration of the dual ETA and ETB antagonist tezosentan prevents the development of pulmonary endothelial dysfunction. A prospective, randomized laboratory investigation. University research laboratory. Landrace swine. Three groups of animals underwent a 90-minute period of full bypass followed by a 60-minute period of reperfusion. Among treated groups, one received tezosentan through inhalation prior to CPB, whereas the other one received it intravenously at weaning from CPB; the third group remained untreated. Pulmonary vascular reactivity studies, realized on a total of 285 rings, were performed in all groups, including 1 sham. The contractility of pulmonary arteries to prostaglandin F2α and to the thromboxane A2 mimetic U46619 was preserved in animals submitted to CPB. By contrast, there were significant increases both in the maximal contraction to endothelin-1 and in the plasma levels of the peptide 60minutes after reperfusion. Tezosentan administered by inhalation or intravenously did not prevent the development of pulmonary CPB-associated endothelial dysfunction. However, while hemodynamic disturbances were improved with both routes, the inhaled administration had a beneficial effect on oxygen parameters over intravenous administration. Despite the blockade of the endothelin-1 pathway with tezosentan, the development of the pulmonary endothelial dysfunction associated with CPB still occurred. However, only the inhalation route had a significant impact on gas exchange during CPB.

Correlation of near-infrared spectroscopy and direct pressure monitoring in an acute porcine compartmental syndrome model.

To correlate near-infrared spectroscopy (NIRS) and the tibial intracompartmental perfusion pressure (TIPP) in an acute limb compartmental syndrome. Landrace swine were subdivided into 2 groups: plasma infusion (n = 16) and blunt trauma plus plasma infusion (n = 15). NIRS sensors were placed over the craniolateral muscle compartment of proximal both tibiae. Albumin infusion elevated tibial intracompartmental pressures (TICP). Time-synchronized measures of systolic, diastolic, and mean arterial pressures, TICP, and percent oxygenation from each leg were collected. For the blunt trauma group, trauma was induced by dropping a 2-kg weight 30 times from 100 cm directly on the muscle compartment. For each group, a repeated-measures analysis of variance model was used to test differences in the TICP, TIPP, and oxygenation values. Pearson correlations were calculated between TICP and oxygenation and between TIPP and oxygenation. Both models created reproducible increases in TICP and decreases in TIPP. Trauma did not alter TICP, TIPP, or percent oxygenation in the model. NIRS was able to detect significant changes in tissue oxygenation at all the same time points. NIRS was able to detect decreased oxygenation at every TIPP decrease and subsequent increase after fasciotomies. An increase in percent oxygenation was seen in all cases once fasciotomy was performed and TICP was reduced. NIRS provided a sensitive measure correlating to both an increase and decrease in TICP and TIPP, respectively, in this infusion model. The addition of blunt trauma to the model did not alter the correlations of NIRS values with TICP and TIPP. Fasciotomy produced a rebound in oxygenation values.

In vitro generation of atrioventricular heart valve neoscaffolds.

Tissue engineering of cardiovascular structures represents a novel approach to improve clinical strategies in heart valve disease treatment. The aim of this study was to engineer decellularized atrioventricular heart valve neoscaffolds with an intact ultrastructure and to reseed them with umbilical cord-derived endothelial cells under physiological conditions in a bioreactor environment. Mitral (n=38) and tricuspid (n=36) valves were harvested from 40 hearts of German Landrace swine from a selected abattoir. Decellularization of atrioventricular heart valves was achieved by a detergent-based cell extraction protocol. Evaluation of the decellularization method was conducted with light microscopy and quantitative analysis of collagen and elastin content. The presence of residual DNA within the decellularized atrioventricular heart valves was determined with spectrophotometric quantification. The described decellularization regime produced full removal of native cells while maintaining the mechanical stability and the quantitative composition of the atrioventricular heart valve neoscaffolds. The surface of the xenogeneic matrix could be successfully reseeded with in vitro-expanded human umbilical cord-derived endothelial cells under physiological flow conditions. After complete decellularization with the detergent-based protocol described here, physiological reseeding of the xenogeneic neoscaffolds resulted in the formation of a confluent layer of human umbilical cord-derived endothelial cells. These results warrant further research toward the generation of atrioventricular heart valve neoscaffolds on the basis of decellularized xenogeneic tissue.

A Novel and Effective Balanced Intravenous-Inhalant Anaesthetic Protocol in Swine by Using Unrestricted Drugs

Nowadays, because of increasing employment of swine for experimental studies and medical training, it is hopeful to investigate novel and effective anaesthetic protocols for preserving the animal welfare in medical investigation and concurrently improving the quality of research. Therefore, the aim of this study was to investigate a novel and effective anaesthetic protocol in swine undergoing major surgery, by translating know-how of combined anaesthesia from human protocols. Seven landrace swine were anaesthetized for three hours by a combined trial anaesthetic protocol (sedation: medetomidine, acepromazine, atropine and tramadol; induction: propofol, medetomidine and acepromazine; anaesthesia: isofluorane, propofol, medetomidine and acepromazine) and both clinical and haemodynamic parameters were compared with those of five swine anaesthetized with a control protocol (sedation: diazepam, ketamine and atropina; induction: diazepam and ketamine; anaesthesia: isofluorane). Both cardiac frequency (CF) and mean blood pressure (MBP) were significantly (P<0.05) more stable in trial protocol (CF: 78.3 ± 4.6-81.1 ± 5, MBP: 63.9 ± 10.7-96.4 ± 13.0) compared to control protocol (CF: 93.7 ± 5.5-102.5 ± 8.5, MBP: 71.0 ± 6.6-108.7 ± 7.2). The body temperature remained stable in trial protocol (°C: 36.9 ± 0.7-37.2 ± 0.3) compared to control anaesthesia (°C: 36.4 ± 0.3-37.3 ± 0.2, P<0.05). Haematosis improved undergoing combined anaesthesia (+2%, P<0.05) whereas did not change in control animals. There were no differences in respiratory rate between trial and control protocols. This study demonstrates that the proposed balanced intravenous-inhalant protocol permits to carry out a very effective, stable and safe anaesthesia in swine undergoing deep anaesthesia.

Novel and effective balanced intravenous-inhalant anaesthetic protocol in swine by using unrestricted drugs.

Nowadays, because of increasing employment of swine for experimental studies and medical training, it is hopeful to investigate novel and effective anaesthetic protocols for preserving the animal welfare in medical investigation and concurrently improving the quality of research. Therefore, the aim of this study was to investigate a novel and effective anaesthetic protocol in swine undergoing major surgery, by translating know-how of combined anaesthesia from human protocols. Seven landrace swine were anaesthetized for three hours by a combined trial anaesthetic protocol (sedation: medetomidine, acepromazine, atropine and tramadol; induction: propofol, medetomidine and acepromazine; anaesthesia: isofluorane, propofol, medetomidine and acepromazine) and both clinical and haemodynamic parameters were compared with those of five swine anaesthetized with a control protocol (sedation: diazepam, ketamine and atropina; induction: diazepam and ketamine; anaesthesia: isofluorane). Both cardiac frequency (CF) and mean blood pressure (MBP) were significantly (P<0.05) more stable in trial protocol (CF: 78.3 ± 4.6-81.1 ± 5, MBP: 63.9 ± 10.7-96.4 ± 13.0) compared to control protocol (CF: 93.7 ± 5.5-102.5 ± 8.5, MBP: 71.0 ± 6.6-108.7 ± 7.2). The body temperature remained stable in trial protocol (°C: 36.9 ± 0.7-37.2 ± 0.3) compared to control anaesthesia (°C: 36.4 ± 0.3-37.3 ± 0.2, P<0.05). Haematosis improved undergoing combined anaesthesia (+2%, P<0.05) whereas did not change in control animals. There were no differences in respiratory rate between trial and control protocols. This study demonstrates that the proposed balanced intravenous-inhalant protocol permits to carry out a very effective, stable and safe anaesthesia in swine undergoing deep anaesthesia.

Comparison of arterial and venous whole blood clot initiation, formation, and strength by thromboelastography in anesthetized swine

Thromboelastography (TEG) analysis was used to determine if differences exist between venous and arterial samples in anesthetized swine, using identical sampling techniques for each of the samples. We hypothesized that TEG parameters would not differ between native whole blood venous and arterial samples. Thirty male Landrace swines were included in the study. Both the femoral artery and vein were catheterized using standard cut-down techniques and with identically sized catheters to rule out any catheter size effects on the results. Standard TEG parameters for native whole venous and arterial blood samples (r, K, α, MA, G, and coagulation index) were measured or calculated, and t-test or Mann-Whitney rank-sum test used for comparison when appropriate. Significant differences were detected for r (venous < arterial), K (venous < arterial), α (venous > arterial), and coagulation index (venous > arterial) TEG parameters. No significant differences were measured for MA or G. These differences are important, especially when temporal changes in TEG are utilized to monitor patient stability and fluid therapy protocols using trends in coagulation properties. Taken together, these results suggest that clots are more likely to form at a faster rate in venous samples compared to arterial samples, but the overall clot strength does not differ. Therefore, if TEG analysis is being used to monitor coagulation profiles in a patient, care should be taken to use the same site and technique if results are to be used for comparative purposes.

Does Tissue Ischemia Actually Contribute To Leak after Sleeve Gastrectomy? An Experimental Study

Staple line leak, although rare, is among the most common postoperative complications after sleeve gastrectomy (SG) and usually occurs in the gastroesophageal (GE) junction. Increased intragastric pressure, regional ischemia, and technical failure of stapling devices have been reported as the main risk factors of postoperative leak. The aim of this study was to evaluate the impact of ischemia and intraluminal pressure in leak appearance. Landrace swine (n = 12) were subjected to SG and total gastrectomy subsequently. Lactic acid, glycerol, and pyruvate were measured by microdialysis in GE junction and pylorus before and nine times after operation, and lactate/pyruvate (L/P) ratio was calculated as well. Moreover, ex vivo air was insufflated inside the tubularized stomach till a rupture of the staple line occurs. Maximum air pressure reached and location of rupture were recorded. Increase of lactic acid and L/P ratio were demonstrated in GE junction measurements; however, when the measurements between GE junction and pylorus were compared, no statistically significant differences were found, with the exception of a slightly increased lactate concentration in pylorus in the midst of measurements. The maximum air pressure recorded varied from 3 to 75mmHg (mean 24.5mmHg) and the majority of ruptures (n = 8) occurred in GE junction. In one of them, clip displacement was noticed. No evidence of increased ischemia in GE junction compared to pylorus was recorded. Increased intraluminal pressure and stapling malfunction may play the most important role in leak appearance.