Adult Female Swine Research Articles

Correlation of Noninvasive Cardiac MRI Measures of Left Ventricular Myocardial Function and Invasive Pressure-Volume Parameters in a Porcine Ischemia-Reperfusion Model.

Purpose To assess the correlation between noninvasive cardiac MRI-derived parameters with pressure-volume (PV) loop data and evaluate changes in left ventricular function after myocardial infarction (MI). Materials and Methods Sixteen adult female swine were induced with MI, with six swine used as controls and 10 receiving platelet-derived growth factor-AB (PDGF-AB). Load-independent measures of cardiac function, including slopes of end-systolic pressure-volume relationship (ESPVR) and preload recruitable stroke work (PRSW), were obtained on day 28 after MI. Cardiac MRI was performed on day 2 and day 28 after infarct. Global longitudinal strain (GLS) and global circumferential strain (GCS) were measured. Ventriculo-arterial coupling (VAC) was derived from PV loop and cardiac MRI data. Pearson correlation analysis was performed. Results GCS (r = 0.60, P = .01), left ventricular ejection fraction (LVEF) (r = 0.60, P = .01), and cardiac MRI-derived VAC (r = 0.61, P = .01) had a significant linear relationship with ESPVR. GCS (r = 0.75, P < .001) had the strongest significant linear relationship with PRSW, followed by LVEF (r = 0.67, P = .005) and cardiac MRI-derived VAC (r = 0.60, P = .01). GLS was not significantly correlated with ESPVR or PRSW. There was a linear correlation (r = 0.82, P < .001) between VAC derived from cardiac MRI and from PV loop data. GCS (-3.5% ± 2.3 vs 0.5% ± 1.4, P = .007) and cardiac MRI-derived VAC (-0.6 ± 0.6 vs 0.3 ± 0.3, P = .001) significantly improved in the animals treated with PDGF-AB 28 days after MI compared with controls. Conclusion Cardiac MRI-derived parameters of MI correlated with invasive PV measures, with GCS showing the strongest correlation. Cardiac MRI-derived measures also demonstrated utility in assessing therapeutic benefit using PDGF-AB. Keywords: Cardiac MRI, Myocardial Infarction, Pressure Volume Loop, Strain Imaging, Ventriculo-arterial Coupling Supplemental material is available for this article. © RSNA, 2024.

Animal Study of a Novel Device for Clampless Proximal Anastomosis in Coronary Bypass Surgery

PurposeLimitations of existing techniques for clampless proximal anastomosis (CPA) in coronary artery bypass grafting include air emboli and excessive bleeding. This study evaluated the safety and performance of a new device for performing CPA. DescriptionThe device includes a temporary adjustable sealing element that is connected by a catheter to a handle that controls its opening and closure. An aortic punch is mounted on the catheter and activated by a detachable handle. EvaluationSix adult female swine underwent partial coronary artery bypass grafting that included construction of a CPA using autologous arterial or venous conduits. During anastomosis construction, good sealing was achieved in all cases, and a blower was not needed in 4 of 6 animals. In the first 2 cases, the blower was intermittently used in 14 % of the entire anastomosis construction time. A mean flow rate of 140.0 ± 52.9 mL/min was measured for the arterial grafts and 666.7 ± 230.9 mL/min for the venous grafts. ConclusionsThe VIOLA device (Vascular Graft Solutions, Tel Aviv, Israel) is safe and associated with good hemostasis and minimal use of a blower during CPA construction in a swine model.

LapVac - a laparoscopic approach for negative pressure wound therapy application in open abdomen management: a porcine animal model.

IntroductionNegative pressure wound therapy (NPWT) in the open abdomen (OA) is recognized as a gold standard management method. Currently minimally invasive procedures are implemented in many clinical scenarios.AimTo demonstrate the feasibility of using negative pressure wound therapy in a laparoscopic approach for OA management in a porcine model termed as a laparoscopic vacuum (LapVac).Material and methodsAn adult female swine underwent a laparoscopic procedure. Briefly, a small incision was made and secured with a wound protector, pneumoperitoneum was created and two additional ports were placed. Then, a non-adhesive layer was precisely placed within the abdominal cavity.ResultsFinally, polyurethane foam and adhesive drape were applied. A volume of 200 ml of saline solution was instilled and drained completely within 30 min. We did not observe any technical problems with NPWT application.ConclusionsThis study confirmed the technical feasibility of NPWT application in the laparoscopic approach. LapVac seems to be a promising technique which may minimize the trauma and lead to better outcomes.

Impella CP or VA-ECMO in profound cardiogenic shock: left ventricular unloading and organ perfusion in a large animal model.

The aim of this study was to evaluate the Impella CP over veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and their impact on left ventricular unloading and end-organ perfusion. Cardiogenic shock (CS) was induced by injecting microspheres into the left coronary artery in fourteen adult female swine. Impella CP or VA-ECMO was initiated in the presence of CS and evaluated after 60 minutes. Left ventricular pressure-volume area (PVA, total mechanical work) was obtained from a conductance catheter. Results are presented as mean (95% confidence interval) and the rank-sum test was used to assess differences between devices. Compared to the CS state, PVA was unaffected by Impella CP and increased on VA-ECMO (from 2,548 [2,193; 2,904] mmHg x mL during CS to 5,775 [4,451; 7,099], between device p-value=0.02). Arterial lactate increased during CS and decreased on support with no difference between devices. Renal venous oxygen saturation decreased during CS and increased on support with no difference between devices. Cerebral venous oxygen saturation increased to 33% [25, 40] on Impella CP and to 69% [49, 89] on VA-ECMO, p=0.04. In this porcine model of profound CS, Impella CP unloaded the left ventricle compared to VA-ECMO. Both devices improved end-organ perfusion, with a tendency towards higher venous oxygen saturations on VA-ECMO.

Elucidation of Percutaneously Accessible Lymph Nodes in Swine: A Large Animal Model for Interventional Lymphatic Research

PurposeTo define percutaneously accessible, anatomically reproducible swine lymph nodes using magnetic resonance imaging, ultrasound, and ethiodized oil (Lipiodol; Guerbet, Bloomington, Indiana) lymphangiography. Materials and MethodsFive adult female swine (Yorkshire, 50–60 kg) were used. Under general anesthesia, T1-weighted and T2-weighted, coronal and axial images of the entire swine were obtained. The animal’s extrathoracic, extraperitoneal soft tissues from the neck to the groins were examined with ultrasound. Lymph nodes ≥ 1 cm were marked before the animal was transferred to the angiography suite. Under ultrasound guidance, the nodes were accessed, and lymphangiograms were obtained. The imaging findings between the 3 modalities were correlated, and the lymph node drainage was mapped. ResultsFour lymph nodes/lymph node groups were identified that were reproducible in all 5 animals, > 1 cm and percutaneously accessible: submandibular node, superficial cervical lymph node group, subiliac node, and superficial inguinal lymph node group. Drainage of these nodes mirrored human anatomy. The abdominopelvic lymphatics formed a retroperitoneal cisterna chyli and drained cephalad via a thoracic duct. ConclusionsThe swine exhibits reproducible lymphatic anatomy with at least 4 percutaneously accessible lymph nodes/lymph node groups. Based on these results, the swine may be a suitable large animal model for research into lymphatic interventions.

Biaxial mechanical properties of swine uterosacral and cardinal ligaments

Mechanical alterations to pelvic floor ligaments may contribute to the development and progression of pelvic floor disorders. In this study, the first biaxial elastic and viscoelastic properties were determined for uterosacral ligament (USL) and cardinal ligament (CL) complexes harvested from adult female swine. Biaxial stress-stretch data revealed that the ligaments undergo large strains. They are orthotropic, being typically stiffer along their main physiological loading direction (i.e., normal to the upper vaginal wall). Biaxial stress relaxation data showed that the ligaments relax equally in both loading directions and more when they are less stretched. In order to describe the experimental findings, a three-dimensional constitutive law based on the Pipkin-Rogers integral series was formulated. The model accounts for incompressibility, large deformations, nonlinear elasticity, orthotropy, and stretch-dependent stress relaxation. This combined theoretical and experimental study provides new knowledge about the mechanical properties of USLs and CLs that could lead to the development of new preventive and treatment methods for pelvic floor disorders.

Physiologic Response to a Simplified Venovenous Perfusion-Induced Systemic Hyperthermia System

Our original venovenous perfusion-induced systemic hyperthermia (vv-PISH) system appeared to significantly improve the survival of patients with lung cancer, but was too complex with numerous dialysis problems. We tested a simplified vv-PISH circuit that includes the Avalon Elite (Avalon Laboratories, LLC, Rancho Dominguez, CA) double lumen cannula, a modified heat exchanger, a water heater/cooler, and a centrifugal pump. The purpose of this study was to evaluate this simplified vv-PISH system (without hemodialyzer) and to investigate the physiologic response to whole-body hyperthermia in pigs. We tested our vv-PISH circuit in healthy adult female swine (n = 7, 55-68 kg). The therapeutic core temperature (42°C), calculated as mean of rectal, bladder, and esophageal temperatures, was achieved in six swine. A maximum difference of 0.5°C was observed between the individual temperature sensor readings, indicating homogeneous heat distribution. Heart rate and mean arterial pressure were transiently altered, but were safely managed. A significant elevation in pulmonary artery pressure occurred during the heating phase, resulting in death of one pig. In all other pigs, pulmonary artery pressure returned to physiologic values during the therapeutic phase. Arterial blood electrolytes were maintained without the need of a dialyzer. Major organ function was within normal parameters. The simplified vv-PISH circuit reliably delivered the hyperthermic dose with no need of dialysis.

Histopathological Evaluation of a Novel Radiofrequency Surgical Ablation System

: Using a porcine model, this feasibility study was undertaken to evaluate the histopathological characteristics of lesions created in the proximity of the pulmonary veins after ablation with a new endoscopic-guided radiofrequency device. : Five adult female swine underwent endoscopic surgical ablation on the epicardial surface of the beating heart. Histologic sections taken from around the pulmonary vein pedicle, representing 10 separate anatomic sites, underwent independent qualitative histopathological evaluation as well as quantitative histomorphometric measurement of lesion depth and section thickness. : Sections from all five animals had histologically identical lesions, with the majority of ablation foci having pronounced thermal injury characterized by deep and extensive zones of acute myocardial necrosis in the absence of tissue charring. Fifty-seven percent (13 of 23) of the lesions were completely transmural and 91% (21 of 23) of the sections demonstrated ≥70% transmurality. No collateral injuries were noted. : This irrigated, suction-stabilized unipolar radiofrequency device can produce histologically transmural lesions around the pulmonary veins and is amenable to endoscopic-guided application on the beating heart.

Extracorporeal heparin adsorption following cardiopulmonary bypass with a heparin removal device--an alternative to protamine.

To evaluate the therapeutic efficacy and applicability of a heparin removal device (HRD) based on plasma separation and poly-L-lysine (PLL) affinity adsorption as an alternative to protamine in reversing systemic heparinization following cardiopulmonary bypass (CPB). A prospective study. University research laboratory. Adult female swine (n=7). Female Yorkshire swine (n=7, 67.3+/-3.5 [SEM] kg) were subjected to 60 mins of right atrium-to-aortic, hypothermic (28 degrees C) CPB. After weaning from CPB, the right atrium was recannulated with a two-stage, dual-lumen cannula which was connected to an HRD via extracorporeal circulation. Blood flow was drained at 1431.2+/-25.4 mL/min from the inferior vena cava, through the plasma separation chamber of the HRD (where heparin was bound to PLL), and reinfused into the right atrium. The HRD run time was determined by a previously established mathematical model of first-order exponential depletion. Heart rate, mean arterial pressure, pulmonary arterial pressure, central venous pressure, kaolin and celite activated clotting time (ACT), activated partial thromboplastin time (APTT), heparin concentration, and plasma free hemoglobin were obtained before, during, and after the use of the HRD. Pre-CPB ACT was 167+/-89 secs (kaolin) and 99+/-7 secs (celite), and APTT was 34+/-5 secs. The HRD run time averaged 27.4 +/-1.5 mins targeted to remove 90% total body heparin. Use of the HRD was not associated with any adverse hemodynamic reactions or increases in plasma free hemoglobin. The heparin concentration immediately following CPB was 4.85+/-0.24 units/mL, with ACT >1000 secs and APTT >150 secs in all animals. During heparin removal, total body heparin content followed first-order exponential depletion kinetics. At the end of the HRD run, heparin concentration decreased to 0.51+/-0.09 units/mL, with kaolin ACT returning to 177+/-22 secs, celite ACT returning to 179+/-17 secs, and APTT returning to 27+/-3 secs (p > .05 vs. pre-CPB baseline for all variables). The HRD is capable of reversal of anticoagulation following CPB without significant blood cell damage or changes in hemodynamics. The HRD, therefore, can serve as an alternative to achieve heparin clearance in clinical situations where use of protamine may be contraindicated.

Distribution of mineralization indices of modeling and remodeling over eight months in middiaphyseal cross sections of femurs from adult swine

Background This study assessed the distribution of active mineral formation sites within the middiaphyseal femoral cross section of swine and determined the extent to which various subsections represented bone formation activity in the entire cross section. Methods Twenty adult female swine (sows) were injected with two double (10-day intervals) labels 8 months apart. Labels involved fluorochrome markers of active mineral formation sites. Intact femoral middiaphyseal cross sections were embedded in polymethylmethacrylate, cut, and ground to 80 μm for analysis. Each specimen was subdivided into 16 anatomical and eight geometric subsections. Labeled mineralizing surface and mineral apposition rate were determined in the periosteal and endocortical envelopes. The number of labeled osteons per unit area of bone and osteonal mineral apposition rate were determined in the intracortical envelope. Results Periosteal mineralizing surface followed a bimodal distribution with highest surface activation on the anterior and posterior segments. Periosteal mineral apposition rate followed a modal distribution with highest apposition rates in the posterior portion of the cross section. The distribution of forming osteons was modal with highest frequencies of labeled osteons in the posterior segment. No significant regional differences were detected for osteonal mineral apposition rate, endocortical mineralizing surface, or endocortical mineral apposition rate. The location of either a single or a combination of two to four subsections that best predicted mineralizing surface and mineral apposition rate in the entire cross section differed with each trait and envelope. Fifty percent of the entire area as alternate anatomical subsections was required to predict >90% of variation in all traits evaluated. Overall, the predictability of mineralizing surface and mineral apposition rate was similar for geometrically defined subsections. Conclusion At least 50% of the cross-sectional area from alternate anatomical subsections must be measured to predict >90% of variation in periosteal, intracortical, and endocortical mineralizing surface and mineral apposition rate in the sow middiaphyseal femur. Anat. Rec. 250:136–145, 1998. © 1998 Wiley-Liss, Inc.

Distribution of mineralization indices of modeling and remodeling over eight months in middiaphyseal cross sections of femurs from adult swine.

This study assessed the distribution of active mineral formation sites within the middiaphyseal femoral cross section of swine and determined the extent to which various subsections represented bone formation activity in the entire cross section. Twenty adult female swine (sows) were injected with two double (10-day intervals) labels 8 months apart. Labels involved fluorochrome markers of active mineral formation sites. Intact femoral middiaphyseal cross sections were embedded in polymethylmethacrylate, cut, and ground to 80 microm for analysis. Each specimen was subdivided into 16 anatomical and eight geometric subsections. Labeled mineralizing surface and mineral apposition rate were determined in the periosteal and endocortical envelopes. The number of labeled osteons per unit area of bone and osteonal mineral apposition rate were determined in the intracortical envelope. Periosteal mineralizing surface followed a bimodal distribution with highest surface activation on the anterior and posterior segments. Periosteal mineral apposition rate followed a modal distribution with highest apposition rates in the posterior portion of the cross section. The distribution of forming osteons was modal with highest frequencies of labeled osteons in the posterior segment. No significant regional differences were detected for osteonal mineral apposition rate, endocortical mineralizing surface, or endocortical mineral apposition rate. The location of either a single or a combination of two to four subsections that best predicted mineralizing surface and mineral apposition rate in the entire cross section differed with each trait and envelope. Fifty percent of the entire area as alternate anatomical subsections was required to predict > 90% of variation in all traits evaluated. Overall, the predictability of mineralizing surface and mineral apposition rate was similar for geometrically defined subsections. At least 50% of the cross-sectional area from alternate anatomical subsections must be measured to predict > 90% of variation in periosteal, intracortical, and endocortical mineralizing surface and mineral apposition rate in the sow middiaphyseal femur.

Biliary lithotripsy. Determination of stone fragmentation success and potential tissue injury in swine.

Application of extracorporeal shock wave lithotripsy to gallbladder stones was studied in 37 adult female swine. Twenty-two sows underwent cholecystostomy with implantation of human gallstones. In 20 animals, after a 10-day recovery period, extracorporeal shock wave lithotripsy, 2000 shocks (an amount determined in preliminary water bath studies to be effective), was performed. In 10 of these implanted swine, frequent focal point refocusing and biplanar ultrasonography were employed. Two animals served as operative controls. Fifteen other animals without gallstone implantation were studied for adverse effects of extracorporeal shock wave lithotripsy on tissue. These animals (unimplanted) received 5000 shocks; 7 animals were killed 1 to 4 days after treatment and the others were killed after 4 weeks. Biochemical tests (total bilirubin, alkaline phosphatase, lipase, amylase, alanine aminotransferase, and lactate dehydrogenase determinations) were performed on all animals at entry and every second or third day until they were killed. Successful fragmentation, defined as all residual gallstone fragments being less than or equal to 4 mm in greatest dimension, was achieved in 14 of 20 animals overall, but in 10 of 10 animals in which focal point refocusing had been used. Slight perivascular hemorrhage and minimal coagulation necrosis were seen histologically only in the liver parenchyma adjacent to the gallbladder bed. The remainder of the liver was grossly and histologically normal. No injuries to the colon, duodenum, common bile duct, or pancreas were observed. No alterations suggesting injury or altered function occurred in any of the biochemical tests.

Limiting amino acids in sorghum grain protein for adult female swine (1984)

Two 4 x 4 Latin square designs were used with 16 gilts at 10 mo of age and weighing 341 lb (gravid) and 301 lb (nongravid) to determine the limiting nitrogenous factors in sorghum grain protein for adult gravid (70th day postcoitum) and nongravid swine. Supplementation of the fortified sorghum grain diet with lysine increased (P<.05) nitrogen retention in both nongravid and gravid gilts. A further addition of threonine also increased (P >.05) nitrogen retention in both nongravid and gravid gilts. However, addition of both lysine and threonine to the sorghum diet failed to result in nitrogen retention equal to that observed for the control diet. Percentage of nitrogen digested was higher (P<.05) for the control diet than for the basal diet or the two diets with lysine and threonine added. Blood urea nitrogen was reduced (P<.05) when lysine was added to the basal diet with an additional reduction when threonine also was added to the diet. However, the control diet caused higher blood urea values when compared to both supplemented diets. These results suggest that another amino acid may be limiting in the sorghum grain diet supplemented with both lysine and threonine. These data and other published data demonstrate that lysine and threonine are the first and second limiting amino acids in sorghum grain for adult gravid and nongravid swine.; Swine Day, Manhattan, KS, November 15, 1984

Sterols in various organs of adult female swine

Sterols in various organs of adult female swine

USE OF AN INFLATABLE CATHETER FOR THE COLLECTION OF URINE FROM ADULT FEMALE SWINE

not available

Limiting Nitrogenous Factors in Corn Protein for Adult Female Swine

Littermate Yorkshire gilts, 10 months of age and weighing 135 kg, were employed in two long-term nitrogen balance assays to determine the limiting nitrogenous factors in corn protein for adult gravid (70th day post-coitum) and nongravid swine. Amino acid additions were designed to bring the concentration of the individual amino acids (or nitrogen in the case of nonspecific nitrogen addition) to the level present in a 12%-protein corn-soybean meal reference diet. Supplementation of the fortified corn diet with 0.25% L-lysine·HC1 increased nitrogen retention in both nongravid and gravid gilts. A further addition of 0.041% L-tryptophan also increased nitrogen retention in both non-gravid and gravid gilts. Addition of nonspecific amino nitrogen (L-glutamic acid and glycine) to the lysine and tryptophan-supplemented diet increased retention of dietary nitrogen by nongravid but not gravid gilts. The data suggest that the first- and second-limiting amino acids in corn protein for young adult female swine, both gravid and non-gravid, are lysine and tryptophan, respectively.