Landrace Pigs Research Articles

Генотипова структура мікропопуляцій свиней вітчизняних порід за локусом ріанодинового рецептора RYR1

An important problem in transplant medicine is the lack of organs and tissues for human transplantation. One of the promising areas of its solution today is the use of organs and tissues of animals — xenotransplantation. Pigs for medical and biological needs must be stress-resistant and adapted to the conditions of keeping and feeding within the vivarium. Stress syndrome in pigs is caused by a point mutation that replaces 1843CT in exon 17 of the ryanodine RYR1 receptor gene in a homozygous state. The aim of the study was to examine the genetic structure of individual pig populations at the locus of the RYR1 gene responsible for hypersensitivity. DNA testing of 102 pigs of Poltava meat, Myrhorod, Great White, Landrace and Pietren breeds was performed. The studies were performed on DNA samples obtained from pig blood. DNA was isolated using Chelex 100 reagent. Studies of the RYR1 gene fragment were performed by restriction fragment length polymorphism (RFPR) by polymerase chain reaction (PCR). Two alleles of the ryanodine RYR1 receptor gene (n and N) and three genotypes (NN, Nn, nn) were identified in the studied animals. A molecular study of pigs of different breeds revealed a polymorphism of the RYR1 gene. The number of animals carrying the recessive allele n of the ryanodine receptor gene RYR1, which is responsible for the sensitivity of pigs to stress factors, varied considerably: from its complete absence in the Vietnamese Pot-bellied, Ukrainian meat, Large White and Ukrainian Spotted Steppe breeds up to 100% of animals of homozygous RYR1nn genotype in the Piétrain breed and 50% of Landrace individuals with the heterozygous RYR1Nn genotype The mutant RYR1n allele was found in animals of the Piétrain breed with a 100% frequency. Heterozygous genotype RYR1Nn was found in pigs of Poltava Meat (10%), Landrace (50%), Myrhorod (15%) Ukrainian Spotted Steppe (50%). Homozygous RYR1NN genotype was detected in all Large White, Vietnamese Pot-bellied, and Ukrainian Meat pigs studied, indicating the absence of stress syndrome. It has been established that pigs of the Great White, Vietnamese Pot-bellied, and Ukrainian Meat breeds are preferred for breeding for biomedical purposes. Breeding of Piétrain pigs and any combinations with this breed makes it impossible to use such animals for biomedical experimental work.

Selection of the Optimal Method for Creating Various Forms of Biocompatible Xenodermal Materials.

The aim of the study was to select the optimal method for creating surgical porcine dermis-based biomaterials and to assess their biological safety.Materials and MethodsTo create xenodermal biomaterials, the native skin of a 4-month-old Landrace pig was used. The porcine dermis was processed with saline (protocol No.1), peroxide-alkaline (protocol No.2), and alkaline (protocol No.3) solutions. The obtained samples were stained with hematoxylin-eosin and a DAPI fluorescent dye. Quantitative DNA analysis and assessment of cytotoxicity by the LIVE/DEAD assay were also performed. Samples were implanted/injected subcutaneously to 6-month-old male Wistar rats (n=30) weighing 260±20 g and explanted on day 14 of the experiment. Histological sections were stained with hematoxylin-eosin. Computer morphometry was performed using GraphPad Prism v. 6.04.ResultsSamples of surgical materials obtained according to the three protocols had different physical characteristics: dermis treated according to protocol No.1 was dense and white in color after processing; samples processed by protocol No.2 were transparent and dense, and samples treated according to protocol No.3 had transparent gel-like structures. Histological analysis has shown oxyphilicity and extracellular matrix structure loss in all samples, and DAPI staining has revealed the destruction of cell nuclei. Nevertheless, DNA amount in the samples processed according to protocol No.1 did not meet the established quality criterion for decellularization (50 ng/mg dry weight). Further cytotoxicity assessment in vitro and in vivo was carried out only for samples fabricated according to protocols No.2 and No.3. According to the LIVE/DEAD analysis, both samples were not cytotoxic. On day 14 after the subcutaneous sample implantation, no signs of suppuration and immune rejection were found in the animals.ConclusionTo obtain surgical materials in the form of bioplastic coatings, it is recommended to use alkaline-peroxide treatment of the dermis, while hydrogel coatings are produced by alkaline hydrolysis.

In vitro and in vivo parameters for identification of landrace pigs with low reproductive performance

In pig farming, measurements of production parameters play a fundamental role in the success of the activity. Minimal differences in fertility between breeders can lead to less reproductive efficiency and, less productivity. However, assessing the fertility of each male and the early identification of subfertile males is a difficult task to be performed. Thus, the aim of this study was to evaluate the use of in vitro and in vivo parameters in the identification of subfertile males of the Landrace breed, aiming to collaborate with genetic improvement programs, routine optimization in the Genetic Diffusion Units (GDUs) and the results of performance. In experiment 1, an approach to identify males with subfertility was evaluated based on retrospective data. For this, the results (averages of birth rates, number of total births and average percentages of female and male piglets per litter) were evaluated for a total of 996 matings and 847 parturitions. The inseminations came from ejaculates of 32 males, who had at least 19 females inseminated with homospermic doses in the concentration of 2.5 x 109 total sperm from the same male. As for the birth rate (BR), an average of 85.47% ± 6.05 was observed with a group of median males, seven males that stood out and one individual (M32) with a performance of 58.06% ± 9.0. For the total number of piglets born (PB) the average was 13.41 ± 0.56, with three males with better performance and one (M32) with very poor performance (8.62 ± 0.59). In experiment 2, it was verified whether evaluations of inseminating doses (ID) of semen in vitro (motility and sperm morphology) after 96 hours of storage had correlations with fertility in vivo, which can be used to identify subfertile males. The evaluations were performed on 30 ejaculates regarding the means of BR and PB, considering only those who had at least 7 females inseminated. There were no correlations between the motility assessments and semen morphological changes and the reproductive parameters evaluated. The results obtained in vivo, referring to BR and PB, demonstrated that it was possible to identify differences between males, the individual (M32) had the worst results for the percentages of BR and PB. It is concluded that there are males of high and low fertility and that only the in vitro analyzes carried out in this study are not enough to categorize them, however, the evaluation of retrospective data was efficient for this purpose.

Quality of Landrace Semen in Yolk Citrate Cement which Plus Glucose with Different Concentrations

The purpose of this study was to determine the effect of using yolk citrate diluent with different concentrations of glucose added on the motility, viability, abnormalities and pH of landrace pig cement.The cement used was fresh cement from a 3 year old Landrace pig stud.This study used an experimental method using a completely randomized design (CRD) with four treatments (P1 5%, P2 10%, P3 15% and P4 20%) and four replications so that there were 16 experimental units.The results showed that the concentration of glucose in the yolk citrate diluent was not significantly different (P>0.05) on the motility of spermatozoa with the average value of each treatment being P1 (65%), P2 (60%), P3 (63, 8%) and P4 (67.5%).The percentage of spermatozoa viability was very significantly different (P<0.01) between treatments, where in treatment P2 was relatively the same as treatment P3 and P4 but higher than treatment P1 with the value of each treatment P1 (83%), P2 (90.1 %), P3 (93.5%) and P4 (91.5%). Percentage of spermatozoa abnormalities resulting from analysis of variance (ANOVA) from each treatment there was a non-significant difference (P>0.05) where the values ​​were P1 (8.2%), P2 (9.2%), P3 (8.1%) and P4 (9.2%). The pH was significantly different (P<0.05) between treatments, where P1 treatment was relatively the same as P2 but higher than P4 treatment. On the other hand, treatment P3 was relatively the same as treatment P1, P2 and P4, with the values ​​of each treatment being P1 (8.36), P2 (7.99), P3 (7.676) and P4 (6.83). It can be concluded that the use of different glucose concentrations in the egg yolk citrate diluent with good quality, namely in the P3 treatment with a glucose concentration of 15%, the average percentage of individual motility was 64%, the percentage of live spermatozoa was 93.5%, the percentage of abnormal spermatozoa was 8.1%. and the average pH of cement is 7.68. It was concluded that the quality semen of Landrace pig could be improved optimally using glucose concentration in egg yolk citrate diluent by 15%.

Spinal fixation after laminectomy in pigs prevents postoperative spinal cord injury.

BackgroundA safe, effective, and ethically sound animal model is essential for preclinical research to investigate spinal medical devices. We report the initial failure of a porcine spinal survival model and a potential solution by fixating the spine.MethodsEleven female Dutch Landrace pigs underwent a spinal lumbar interlaminar decompression with durotomy and were randomized for implantation of a medical device or control group. Magnetic resonance imaging (MRI) was performed before termination.ResultsNeurological deficits were observed in 6 out of the first 8 animals. Three of these animals were terminated prematurely because they reached the predefined humane endpoint. Spinal cord compression and myelopathy was observed on postoperative MRI imaging. We hypothesized postoperative spinal instability with epidural hematoma, inherent to the biology of the model, and subsequent spinal cord injury as a potential cause. In the subsequent 3 animals, we fixated the spine with Lubra plates. All these animals recovered without neurological deficits. The extent of spinal cord compression on MRI was variable across animals and did not seem to correspond well with neurological outcome.ConclusionThis study shows that in a porcine in vivo model of interlaminar decompression and durotomy, fixation of the spine after lumbar interlaminar decompression is feasible and may improve neurological outcomes. Additional research is necessary to evaluate this hypothesis.

Rare isolation of human-tropic recombinant porcine endogenous retroviruses PERV-A/C from Göttingen minipigs

BackgroundPorcine endogenous retroviruses (PERVs) can infect human cells and pose a risk for xenotransplantation when pig cells, tissues or organs are transplanted to human recipients. Xenotransplantation holds great promise to overcome the shortage of human donor organs after solving the problems of rejection, functionality and virus safety. We recently described the transmission of a human-tropic recombinant PERV-A/C, designated PERV-F, from peripheral blood mononuclear cells (PBMCs) of a Göttingen Minipig (GöMP) to human 293 cells (Krüger et al., in Viruses 12(1):38, 2019). The goal of this study was to characterize PERV-F in more detail and to analyze the probability of virus isolation from other animals.MethodsThe recombination site in the envelope (env) gene, the long terminal repeats (LTR), the proteins and the morphology of the recombinant PERV-F were characterized by polymerase chain reaction (PCR), sequencing, Western blot analysis, immunofluorescence, and transmissible electron microscopy. Mitogen-stimulated PBMCs from 47 additional pigs, including 17 new GöMP, were co-cultured with highly susceptible human 293 T cells, and the PERV-A/C prevalence and PERV transmission was analyzed by PCR.ResultsPERV-F, isolated from a GöMP, is an infectious human-tropic PERV-A/C virus with a novel type of recombination in the env gene. The length of the LTR of PERV-F increased after passaging on human cells. In a few minipigs, but not in German landrace pigs, PERV-A/C were found. There was no transmission of human-tropic PERV-A/C from additional 47 pigs, including 17 GöMP, to human cells.ConclusionThese data show that human-tropic recombinant PERV-A/C proviruses can only be found in a very small number of minipigs, but not in other pigs, and that their isolation as infectious virus able to replicate on human cells is an extremely rare event, even when using highly susceptible 293 cells.

24-hour Perfusion of Porcine Myocutaneous Flaps Mitigates Reperfusion Injury: A 7-day Follow-up Study.

Background:Static cold storage is the gold standard of preservation in vascularized composite allotransplantation and allows a preservation time of 4–6 hours. Machine preservation is a promising technique for prolonged preservation; however, studies on extended preservation that compare different preservatives are scarce. This study aims to assess the feasibility of 24-hour acellular perfusion and compares different preservation solutions in a porcine myocutaneous flap replantation model.Methods:Six harvested bilateral myocutaneous flaps of three Dutch Landrace pigs were perfused hypothermically for 24 hours with University of Wisconsin machine perfusion solution (UW-MPS; n = 2) or histidine-tryptophan-ketoglutarate solution (HTK; n = 2) or preserved on ice for 4 hours (n = 2) before orthotopic replantation. Animals were observed for 7 days after replantation. Skeletal muscle injury was assessed by biochemical markers during perfusion, and muscle biopsies were analyzed for ischemia reperfusion injury directly after preservation and at 1, 3, and 7 days after replantation.Results:Markers of muscle damage varied during perfusion, but decreased overall in both perfusion groups. Flap weight increased 60% and 97% in the HTK-perfused flaps, compared with -6% and -7% in the UW-MPS-perfused flaps after 24 hours. Histopathologic evaluation demonstrated decreased muscle damage in flaps perfused with HTK compared with the UW-MPS-perfused flaps at 1 week after replantation.Conclusions:Machine perfusion of myocutaneous flaps for 24 hours with subsequent replantation is feasible, but warrants further research. Perfusion with HTK solution seemed to result in better histological outcomes 7 days after reperfusion compared with UW-MPS.

Multiparametric Monitoring of Early Pathophysiological Changes in a Porcine Model of Sequential Focal and Global Cerebral Ischemia

Large animal models of cerebral ischemia have the potential to increase the translational value of stroke research. This study aims to measure early changes of brain tissue oxygen pressure (ptiO2) and cerebral blood flow (CBF) to characterize a porcine model of sequential middle cerebral artery occlusion (MCAO) and common carotid artery occlusion (CCAO). Eight juvenile German Landrace pigs received unilateral MCAO via a frontotemporal approach under continuous intraparenchymal multiparametric monitoring. Insufficient reduction (i.e., <50% in both ptiO2 and CBF) was followed by additional bilateral CCAO. Neurodegenerative changes were detected by Fluoro-Jade B (FJB) staining. Only 1 of 8 animals demonstrated a decrease of >50% in both ptiO2 and CBF after MCAO. Additional CCAO in 7 pigs led to a significant reduction of both ipsilateral and contralateral ptiO2 (P < 0.01) but not of CBF. There was no difference in ptiO2 and FJB positive area between hemispheres in this group. Measurement of ptiO2 correlated negatively with the FJB positive area (P < 0.05). Intraparenchymal multiparametric measurements of acute changes in ptiO2 and CBF were variable after MCAO. Bilateral CCAO led to a consistent decrease in ptiO2 and correlated with early degenerative histologic changes, but CBF did not. Real-time procedural ptiO2 monitoring could provide useful guidance in large animal ischemia models. Feasibility in the context of global cerebral hypoperfusion is demonstrated.

Cloning of FITM2 gene and investigating its expression levels in Banna miniature inbred pig (Sus scrofa) tissues

Fat storage-inducing transmembrane protein 2 (FITM2) plays an important role in regulating lipid storage and could be regarded as a candidate gene for intramuscular fat deposition in pigs. The aim of this study was to clone the coding domain sequence (CDS) of FITM2 gene, to compare the nucleotide acid and deduced amino acid sequences between breeds and species, to analyze the structure and characteristics of protein and to detect the expression profile of gene. The results exhibited that the CDS of FITM2 gene was 789 bp in length. The mutation of nucleotide acids led to the mutation of deduced amino acids between Banna miniature inbred pigs and other two breeds (Yorkshire × Landrace pigs and Duroc × (Landrace × Yorkshire) pigs). It was indicated that high identities of nucleotide acid and deduced amino acid sequences between Banna miniature inbred pigs and other species. The deduced amino acids were composed of loops and alpha helices in the structure. FITM2 protein may be a 30 kDa hydrophobic protein with 26 phosphorylation sites and one potential N-glycosylated site. FITM2 gene was widely expressed in various tissues, and the highest expression level was in adipose tissue.

A Comparative Analysis of Metabolic Profiles of Embryonic Skeletal Muscle from Lantang and Landrace Pigs.

Simple SummaryThe pig is one of the most important domesticated meat animals. Some studies have revealed that pigs with low meat production show more intense myogenesis at the early stage of embryonic muscle development than pigs with high meat production. Here, by gas chromatography–mass spectrometry GC–MS based metabolomics, we concluded that the nucleotide metabolism and energy metabolism of the longissimus lumborum (LL) were increased in Lantang pigs compared with Landrace pigs, indicating rapid synthesis of nucleic acids and ATP to meet the material and energy requirements of rapid cell proliferation and differentiation in Lantang pigs.Elucidation of the complex regulation of porcine muscle development is key to increasing pork output and improving pork quality. However, the molecular mechanisms involved in early porcine embryonic muscle development in different pig breeds remain largely unknown. Here, GC–MS based metabolomics and metabolomic profiling was used to examine the longissimus lumborum (LL) of the Lantang (LT) and the Landrace (LR) pig at embryonic day 35 (E35). Metabolites showed clear separation between LT and LR, with 40 metabolites having higher abundances in LT and 14 metabolites having lower abundances in LT compared with LR. In addition, these metabolic changes were mainly associated with nucleotide metabolism and energy metabolism, such as purine metabolism, pyrimidine metabolism, the pentose phosphate pathway, and the TCA cycle. More interestingly, the contents of DNA, RNA, and ATP per unit mass of LL tissues were higher in LT, indicating rapid synthesis of nucleic acids and ATP, to meet both the material and energy requirements of rapid cell proliferation and differentiation. Furthermore, enzyme activity associated with the TCA cycle and pentose phosphate pathway, including α-ketoglutaric dehydrogenase (KGDH), malate dehydrogenase (MDH), pyruvate dehydrogenase (PDH), succinate dehydrogenase (SDH), and glucose-6-phosphate dehydrogenase (G6PDH), were higher in LT. Based on these results, we conclude that there are significant differences in nucleotide metabolism and energy metabolism of LL between LT and LR, and we speculate that the enhanced nucleic acid metabolism and energy metabolism in LT can meet the material and energy requirements of rapid cell proliferation and differentiation, making myogenesis more intense in LT compared to LR which might be the metabolic mechanism underlying the distinct skeletal muscle development in the two breeds.

Growth of Intestinal Neomucosa on Pedicled Gastric Wall Flap, a Novel Technique in an Animal Model

Background: Short bowel syndrome (SBS) remains an unsolved issue in modern medicine. Numerous experimental surgical techniques have been proposed in the attempt to increase the intestinal absorptive capacity. Materials and Methods: Ten female Landrace pigs, divided in two groups of 5 (A and B), were explored through a midline incision. A spindle-shaped vascularized full-thickness gastric wall flap (GWF) consisting of part of the major curvature with the gastroepiploic arch preserved was de-epithelialized and then placed as a “patch” to cover an antimesenteric border defect of either a nonfunctional blind intestinal loop (group A) or a functional intestinal loop of the gastrointestinal tract (group B). A spindle-shaped curved, rigid, low density polyethylene (LDPE) splint was sutured on the external surface of the patch in order to prevent shrinkage of GWF and collapse of the intestinal wall in group A. Results: There was a decrease of both dimensions of the patch. Microscopically a thin layer of columnar epithelial cells covered the center of the patch, evolving in shorter, blunt, poorly developed villi with increasing maturation laterally. The patch surface was covered by nearly 90%. In the three animals that died prematurely the coverage of GWF was negligent or suboptimal directly dependent on the length of survival. Conclusions: The hereby-described patching technique demonstrated the growth of intestinal neomucosa on the GWF. The capability of the stomach to provide large flaps and the advantages of the use of native tissues render this animal model valuable for the future research in the field.

Integrative Analysis of the lncRNA-Associated ceRNA Regulatory Network Response to Hypoxia in Alveolar Type II Epithelial Cells of Tibetan Pigs.

The function of alveolar type II epithelial (ATII) cells is severely hampered by oxygen deficiency, and understanding the regulatory mechanisms controlling responses to hypoxia may assist in relieving injury induced by hypoxia. In this study, we cultured ATII cells from Tibetan pigs and Landrace pigs under hypoxic and normoxic environments to screen for differentially expressed (DE) lncRNAs, DEmiRNAs, and construct their associated ceRNA regulatory networks in response to hypoxia. Enrichment analysis revealed that target genes of DElncRNAs of Tibetan pigs and Landrace pig between the normoxic (TN, LN) and hypoxic (TL, LL) groups significantly enriched in the proteoglycans in cancer, renal cell carcinoma, and erbB signaling pathways, while the target genes of DEmiRNAs were significantly enriched in the axon guidance, focal adhesion, and mitogen-activated protein kinase (MAPK) signaling pathways. Hypoxia induction was shown to potentially promote apoptosis by activating the focal adhesion/PI3K-Akt/glycolysis pathway. The ssc-miR-20b/MSTRG.57127.1/ssc-miR-7-5p axis potentially played a vital role in alleviating hypoxic injury by regulating ATII cell autophagy under normoxic and hypoxic conditions. MSTRG.14861.4-miR-11971-z-CCDC12, the most affected axis, regulated numerous RNAs and may thus regulate ATII cell growth in Tibetan pigs under hypoxic conditions. The ACTA1/ssc-miR-30c-3p/MSTRG.23871.1 axis is key for limiting ATII cell injury and improving dysfunction and fibrosis mediated by oxidative stress in Landrace pigs. Our findings provide a deeper understanding of the lncRNA/miRNA/mRNA regulatory mechanisms of Tibetan pigs under hypoxic conditions.

Hyperthermia-induced doxorubicin delivery from thermosensitive liposomes via MR-HIFU in a pig model

PurposeEncapsulation of cytotoxic drugs for a localized release is an effective way to increase the therapeutic window of such agents. In this article we present the localized release of doxorubicin (DOX) from phosphatidyldiglycerol (DPPG2) based thermosensitive liposomes using MR-HIFU mediated hyperthermia in a swine model. Materials and methodsGerman landrace pigs of weights between 37.5 and 53.5 kg received a 30-min infusion of DOX containing thermosensitive liposomes (50 mg DOX/m2). The pigs' biceps femoris was treated locally in two separate target areas with mild hyperthermia using magnetic resonance guided high intensity focused ultrasound, starting 10 min and 60 min after initiation of the infusion, respectively. The pharmacokinetics and biodistribution of DOX were determined and an analysis of the treatment parameters' influence was performed. ResultsCompared to untreated tissue, we found a 15-fold and a 7-fold increase in DOX concentration in the muscle volumes that had undergone hyperthermia starting 10 min and 60 min after the beginning of the infusion, respectively. The pharmacokinetic analysis showed a prolonged circulation time of DOX and a correlation between the AUC of extra-liposomal DOX in the bloodstream and the amount of DOX accumulated in the target tissue. ConclusionsWe have demonstrated a workflow for MR-HIFU hyperthermia drug delivery that can be adapted to a clinical setting, showing that HIFU-hyperthermia is a suitable method for local drug release of DOX using DPPG2 based thermosensitive liposomes in stationary targets. Using the developed pharmacokinetic model, an optimization of the drug quantity deposited in the target via the timing of infusion and hyperthermia should be possible.

Left ventricular mass quantification by echocardiography; a novel accurate and more reproducible 2D-method validated by cardiac magnetic resonance in humans and cardiac autopsy in pigs

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): The research fund of The Heart Center at Rigshospitalet, Denmark Background Left ventricular mass (LVM) is a strong independent risk factor for adverse cardiovascular events, but conventional echocardiographic methods used to assess and monitor individuals are currently limited by poor reproducibility and accuracy. Purpose We aimed to develop and validate an echocardiographic method for LVM-quantification that is simple, reproducible and accurate. Methods Our ‘novel method’ (Figure) adds the left ventricular wall thickness (t) to the left ventricular end-diastolic volume acquired by endocardial tracings using the biplane method of discs. For development of the novel method, cardiac assessment was performed using echocardiography followed immediately by gold standard cardiac magnetic resonance (CMR) in 85 humans with different left ventricular geometries, ranging from patients with various cardiac disorders (n = 41) to individuals without known cardiac disorders (n = 44). We compared the novel two-dimensional (2D) method to various conventional one-dimensional (1D) and 2D methods as well as three-dimensional (3D) echocardiography. Validation against anatomical LVM by cardiac autopsy was performed in thirty-four Danish Landrace pigs, weight 47-59 kg. Echocardiography was performed during anaesthesia, the pigs were euthanised, the heart explanted, and cardiac autopsy was performed where the left ventricle was trimmed and weighed for autopsy LVM. Results In humans, the novel method had better reproducibility in intra-examiner (coefficients of variation (CV) 8.6% vs. 11.0-14.5%) and inter-examiner analysis (CV 9.0% vs. 10.2-19.6%) than any other method, including 3D (CV intra-examiner 14.3%, inter-examiner 16.6%). Accuracy of the novel method against CMR was similar to 3D (mean difference ± 95% limits of agreement, CV): Novel: 2 ± 50g, 15.4% vs. 3D: 2 ± 51g, 15.6%; and better than the 1D-method by Devereux (7 ± 76g, 23.0%). Feasibility for the novel method was 95%. Autopsy validation in pigs confirmed high reproducibility; intra-examiner (CV 8.7% vs. 9.1-11.4%) and inter-examiner-analysis (CV 8.7% vs. 8.8-10.0%). Accuracy of the novel method against autopsy LVM was better than for the conventional echocardiographic methods: Novel -1 ± 20g, 7.8% vs. Devereux 26 ± 37g, 11.3%. 3D-validation was not available in pigs. Conclusions The novel 2D-based method for LVM-quantification had better reproducibility than any other echocardiographic method. Accuracy was similar to 3D and better than any conventional method. Autopsy validation in pigs supported our findings amongst the human population. As endocardial tracings using the biplane method forms part of the standard echocardiographic protocol, the novel method can easily be integrated into any echocardiographic software without substantially increasing analysis time, and provides an equivalent yet simpler alternative to 3D echocardiography. Abstract Figure.

Identification of Potential Candidate Genes From Co-Expression Module Analysis During Preadipocyte Differentiation in Landrace Pig.

Preadipocyte differentiation plays an important role in lipid deposition and affects fattening efficiency in pigs. In the present study, preadipocytes isolated from the subcutaneous adipose tissue of three Landrace piglets were induced into mature adipocytes in vitro. Gene clusters associated with fat deposition were investigated using RNA sequencing data at four time points during preadipocyte differentiation. Twenty-seven co-expression modules were subsequently constructed using weighted gene co-expression network analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed three modules (blue, magenta, and brown) as being the most critical during preadipocyte differentiation. Based on these data and our previous differentially expressed gene analysis, angiopoietin-like 4 (ANGPTL4) was identified as a key regulator of preadipocyte differentiation and lipid metabolism. After inhibition of ANGPTL4, the expression of adipogenesis-related genes was reduced, except for that of lipoprotein lipase (LPL), which was negatively regulated by ANGPTL4 during preadipocyte differentiation. Our findings provide a new perspective to understand the mechanism of fat deposition.

Portocaval shunt can optimize transhepatic flow following extended hepatectomy: a short-term study in a porcine model

The aim of this study was to evaluate whether the portocaval shunt (PCS) corrects these unwanted changes in transhepatic flow after extended hepatectomy (EH). Forty female Landrace pigs were divided into two main groups: (A) EH (75%) and (B) no EH. Group A was divided into 3 subgroups: (A1) EH without PCS; (A2) EH with side-to-side PCS; and (A3) EH with end-to-side PCS. Group B was divided into 2 subgroups: (B1) side-to-side PCS and (B2) end-to-side PCS. HAF, PVF, and PVP were measured in each animal before and after the surgical procedure. EH increased the PVF/100 g (173%, p < 0.001) and PVP (68%, p < 0.001) but reduced the HAF/100 g (22%, p = 0.819). Following EH, side-to-side PCS reduced the increased PVF (78%, p < 0.001) and PVP (38%, p = 0.001). Without EH, side-to-side PCS reduced the PVF/100 g (68%, p < 0.001) and PVP (12%, p = 0.237). PVP was reduced by end-to-side PCS following EH by 48% (p < 0.001) and without EH by 21% (p = 0.075). PCS can decrease and correct the elevated PVP and PVF/100 g after EH to close to the normal values prior to resection. The decreased HAF/100 g in the remnant liver following EH is increased and corrected through PCS.

Effects of different routes of heparin on instant blood-mediated inflammatory reaction after portal vein islet transplantation.

Heparin is mainly used as an anticoagulant in clinic, and it also has a certain anti-inflammatory effect. At present, after portal vein islet transplantation in diabetic patients, heparin is mainly infused through the peripheral veins of the limbs to achieve the purpose of anticoagulation and protection of the graft, rather than through the portal vein. In this study, animal experiments were conducted to investigate the effect of heparin infusion via the portal vein and marginal ear vein on the instant blood-mediated inflammatory reaction (IBMIR) after portal vein islet transplantation, which is the choice of anticoagulation methods for clinical islet transplantation to provide a basis for decision-making. A total of 50 neonatal pigs (Xeno-1 type, 3-5 days) were selected. Islets were isolated and purified from the pancreas of neonatal pigs. Ten non-diabetic Landrace pigs (1.5-2.0 months) served as recipients, and 12 000 IEQ/kg neonatal porcine islets were transplanted into the liver through the portal vein. All recipients received bolus injection of 50 U/kg of heparin 10 minutes before transplantation. After the bolus injection of heparin, the experimental group received heparin via the portal vein [10 U/(kg·h), 5 recipients], and the control group received heparin via the marginal ear vein [10 U/(kg·h), 5 recipients]. The superior vena cava blood was collected from the 2 groups pre-operation at 1, 3, 24 h post-operation of the transplantation. The portal vein blood was collected from the experimental group at 1 and 3 h after the transplantation as well. The levels of complement C3a, C5a, thrombin-antithrombin complex (TAT), β-thromboglobulin (β-TG), and D-dimer as well as activated partial thromboplastin time (APTT) in superior vena cava blood from 1 and 3 h post-transplantation were detected in the 2 groups, and the levels of anti-Xa and anti-IIa in the portal vein and superior vena cava blood from 1 and 3 h post-transplantation in the experimental group were detected. Twenty four hours after the transplantation, the liver tissues in the 2 groups were collected for pathological examination to observe the inflammatory cell infiltration and peripheral thrombosis around the islets graft in liver. Before transplantation, there was no statistically significant difference in C3a, C5a, TAT, β-TG, D-dimer levels and APTT between the 2 groups (all P>0.05). At 1 and 3 h after transplantation, the C3a, TAT, and D-dimer levels in the experimental group were significant decreased than those in the control groups (all P<0.05), and at 3 h after transplantation the C5a was significant decreased than that in the control group (P<0.05). At 1 and 3 h after transplantation, the anti-Xa and anti-IIa levels in the portal vein blood were significantly increased than those in the superior vena cava blood in the experimental group (all P<0.05). Pathological results showed the presence of islet cell clusters in the liver blood vessels. The thrombus formation and neutrophil infiltration around islet graft was not obvious in the experimental group, while massive thrombus formation and neutrophil infiltration in the control group. Compared with marginal ear vein infusion of heparin, the direct infusion of heparin in the portal vein has a certain inhibitory effect on complement system, coagulation system activation and inflammatory cell infiltration in portal vein islet transplantation, which may attenuate the occurrence of IBMIR.

A practical guide to setting up pig models for cardiovascular catheterization, electrophysiological assessment and heart disease research.

Over the past years, the use of large animals has become increasingly interesting in translational research, to bridge the gap between basic research in rodents and targeted therapies in humans. Pigs are highly valued in cardiovascular research because of their anatomical, hemodynamic and electrophysiological features, which closely resemble those of humans. For studying these aspects in swine, cardiac catheterization techniques are essential procedures. Although cardiac catheterization seems to be comparatively easy in pigs as human equipment can be used to perform the procedure, there are some pitfalls. Here we provide a detailed protocol to guide the reader through different aspects of cardiac catheterization in pigs. We suggest an approach for safe intubation and extubation, provide tips for perioperative and postoperative management of the animals and guide the reader through different experimental steps, including sheath insertion. We also describe the procedures for basic electrophysiological assessment of conduction properties and atrial fibrillation induction, hemodynamic assessment via pressure-volume loops, right heart and left heart catheterization and the development of a myocardial infarction model by balloon occlusion. This protocol was developed in Landrace pigs and can be adapted to other pig breeds or other large animal species. This protocol requires approximately six and a half working hours in total and should be performed by researchers with previous experience in large animal experimentation and in the presence of a veterinarian.

Segmental composition of the porcine iliopsoas muscle and influence of the body size and posture on the composition of the iliopsoas muscle

The iliopsoas muscle (IPM) of the pig consists of the iliacus muscle (IM) and the psoas major muscle (PMM). Due to the differences in posture and size between animal species, the musculoskeletal system is subjected to different functional demands, which affects the morphological characteristics of the musculoskeletal system. The aim of this study was to determine the muscle fiber type composition in pigs IPM, as pigs are large quadrupeds that differ in body size and posture from humans and small mammals, and to determine the influence of body size and posture on the composition of IPM. Muscle samples were collected from the Pietrain Landrace pigs, a sample from IM and a samples at four segments of the PMM. Samples were analyzed with monoclonal antibodies specific for different isoforms of the myosin heavy chain. The percentages and cross-sectional area (CSA) of type I, IIA, and IIX/IIB muscle fibers were calculated. Our studies revealed that in pigs IPM, type IIX/IIB muscle fibers were predominant with the largest CSA. A decrease in the proportion of type IIX/IIB muscle fibers, an increase in type I and IIA muscle fibers, and a decrease in the CSA of all muscle fiber types from the cranial to the caudal part of the PMM were observed. The pig IPM has primarily a dynamic function. The function of the PMM in the cranio-caudal direction changes from a dynamic to a static role. Body size and posture influence the composition of the IPM.

Transcriptome and Metabolome Integration Provides New Insights Into the Regulatory Networks of Tibetan Pig Alveolar Type II Epithelial Cells in Response to Hypoxia

Tibetan pigs show a widespread distribution in plateau environments and exhibit striking physiological and phenotypic differences from others pigs for adaptation to hypoxic conditions. However, the regulation of mRNAs and metabolites as well as their functions in the alveolar type II epithelial (ATII) cells of Tibetan pigs remain undefined. Herein, we carried out integrated metabolomic and transcriptomic profiling of ATII cells between Tibetan pigs and Landrace pigs across environments with different oxygen levels to delineate their signature pathways. We observed that the differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs) profiles displayed marked synergy of hypoxia-related signature pathways in either Tibetan pigs or Landrace pigs. A total of 1,470 DEGs shared between normoxic (TN, ATII cells of Tibetan pigs were cultured under 21% O2; LN, ATII cells of Landrace pigs were cultured under 21% O2) and hypoxic (TL, ATII cells of Tibetan pigs were cultured under 2% O2; LL, ATII cells of Landrace pigs were cultured under 2% O2) groups and 240 DAMs were identified. Functional enrichment assessment indicated that the hypoxia-related genes and metabolites were primarily involved in glycolysis and aldosterone synthesis and secretion. We subsequently constructed an interaction network of mRNAs and metabolites related to hypoxia, such as guanosine-3′, 5′-cyclic monophosphate, Gly-Tyr, and phenylacetylglycine. These results indicated that mitogen-activated protein kinase (MAPK) signaling, aldosterone synthesis and secretion, and differences in the regulation of MCM and adenosine may play vital roles in the better adaptation of Tibetan pigs to hypoxic environments relative to Landrace pigs. This work provides a new perspective and enhances our understanding of mRNAs and metabolites that are activated in response to hypoxia in the ATII cells of Tibetan pigs.