OBJECTIVE: To investigate the effect of mild hypothermia on neurological function in rats with spinal cord injury (SCI) based on the adenosine monophosphate activated protein kinase (AMPK)/Nod-like receptor protein 3 (NLRP3) pathway. METHODS: Fifty 7-8 weeks old SPF male Sprague Dawley rats were used to establish rat model of SCI by Allen's method. Among them, 48 successfully modeled rats were randomly divided into SCI group, mild hypothermia group (SCI+mild hypothermia treatment), and Compound C group (SCI+mild hypothermia+intraperitoneal injection of 20 mg/kg AMPK/NLRP3 pathway inhibitor Compound C), with 16 rats in each group. Another 16 normal rats with laminectomy were selected as sham-operation group. Basso-Beattie-Bresnahan (BBB) score was used to evaluate the motor ability of rats at 1, 3, 7, 14 days after treatment. After 14 days, the rats were sacrificed, and the spinal cord histopathological morphology was observed by HE staining, the neuronal apoptosis in spinal cord tissue was detected by TUNEL assay, and the serum levels of interleukin 2 (IL-2), IL-6, transforming growth factor β ₁ (TGF-β ₁), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by ELISA. The expressions of AMPK/NLRP3 pathway proteins in spinal cord tissue, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved-Caspase-9 were detected by Western blot. RESULTS: At 1 day after treatment, the rats in SCI group, mild hypothermia group, and Compound C group did not recover their motor ability. With the prolongation of time, the motor function of rats in each group gradually recovered. Among them, the BBB score of SCI group was significantly lower than that of sham-operation group and mild hypothermia group ( P<0.05), and the BBB score of Compound C group was significantly lower than that of mild hypothermia group ( P<0.05). Compared with the sham-operation group, the SCI group displayed obvious pathological changes in the spinal cord tissue, with disordered tissue architecture, inflammatory infiltration, and blurred interstitial boundaries. The neuronal apoptosis rate, Bax/Bcl-2 ratio, cleaved Caspase-9 expression, NLRP3 protein expression, serum IL-2, IL-6, and MDA levels were elevated, whereas serum TGF-β ₁, SOD levels, and spinal cord phosphorylation AMPK/AMPK protein expression significantly decreased ( P<0.05). Compared with the SCI group, the above phenomena significantly improved in the mild hypothermia group ( P<0.05), while the Compound C group showed the opposite trend of change compared to the mild hypothermia group ( P<0.05). CONCLUSION Mild hypothermia can attenuate neurological dysfunction after SCI in rats, potentially by activating the AMPK/NLRP3 pathway.
Animals ; Spinal Cord Injuries/physiopathology* ; Rats, Sprague-Dawley ; Male ; Rats ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Hypothermia, Induced ; Signal Transduction ; Spinal Cord/pathology* ; Apoptosis ; Interleukin-6/metabolism* ; Disease Models, Animal ; bcl-2-Associated X Protein/metabolism* ; Superoxide Dismutase/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 9/metabolism*

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with diverse clinical symptoms, which involves multiple systems and organs such as the kidney, cardiovascular system, and nervous system. The main characteristic of SLE is the mistaken attacks on self-tissues by the immune system, but the specific pathogenesis is still unclear. This paper reviews and compares the modeling mechanisms and main pathological manifestations of spontaneous and experimental mouse models of SLE, which can provide evidences for selecting appropriate mouse models in studies on the pathogenesis, clinical diagnosis and treatment of SLE.
Animals ; Lupus Erythematosus, Systemic/immunology* ; Disease Models, Animal ; Mice ; Humans

Objective To explore the effect of Evodiamine (Evo) on the immune function of allergic rhinitis (AR) rats and the regulatory mechanism on C-C motif chemokine ligand 2 (CCL2)/ C-C motif chemokine receptor 2 (CCR2) pathway. Methods The related targets of Evo-AR-immune function were screened by network pharmacology, and the protein interaction network diagram of intersecting targets was constructed. The AR rat model was established by ovalbumin (OVA) combined with aluminium hydroxide, and the rats were divided into six groups: a normal control (NC) group, a model group, a Loratadine (LOR) group, an Evodiamine low dose (Evo-L) group, a Evodiamine high dose (Evo-H) groups, and an Evo-H combined with CCL2 group. After the last administration, the symptoms of rats in each group were scored; ELISA was applied to detect the levels of histamine, immunoglobulin E (IgE), interleukin 4 (IL-4), IL-13 and interferon γ (IFN-γ); Diff-Quick staining solution was applied to detecte the number of cells in the nasal lavage fluid (NALF); hematoxylin eosin (HE) staining was applied to observe the pathological changes of nasal mucosa tissue; real-time quantitative PCR was applied to detect the levels of CCL2 and CCR2 mRNA in tissue; Western blot was applied to detect the expression levels of CCL2, CCR2 and CXC motif chemokine ligand 8 (CXCL8) proteins in nasal mucosa. Results There were eight intersection targets of EVo-AR-immune function, and protein interaction network diagram showed that CXCL8 was the core target. Compared with the NC group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in the model group were increased, while the level of IFN-γ was decreased. Compared with the model group, the score of nasal symptoms, the levels of histamine, IgE, IL-4 and IL-13, the numbers of eosinophil, macrophages, neutrophils, lymphocytes and total cells, the mRNA and protein expression levels of CCL2 and CCR2, and the expression of CXCL8 protein in LOR and Evo groups were decreased, while the level of IFN-γ was increased. Further use of CCL2 recombinant protein for compensatory experiments revealed that the improvement effect of Evo on immune function in AR rats was reversed by CCL2. Conclusion Evo can improve the immune function of AR rats, and its mechanism may be related to the inhibition of the CCL2/CCR2 pathway.
Animals ; Receptors, CCR2/immunology* ; Signal Transduction/drug effects* ; Chemokine CCL2/immunology* ; Rats ; Rhinitis, Allergic/metabolism* ; Immunoglobulin E/blood* ; Quinazolines/pharmacology* ; Male ; Interferon-gamma ; Rats, Sprague-Dawley ; Interleukin-13 ; Histamine ; Interleukin-4/immunology* ; Disease Models, Animal

Objective To explore the effects of S100 calcium-binding protein A9 (S100A9) gene knockout on the phenotype of systemic lupus erythematosus (SLE) in mice and to clarify the role of S100A9 in the pathogenesis of SLE. Methods Ten female C57BL/6 wild-type and S100A9 knockout (S100A9-KO ) mice were selected, with five wild-type and five S100A9-KO B6 mice receiving imiquimod (IMQ) cream to establish SLE mouse model. The other five wild-type and five S100A9-KO B6 mice were treated as control groups by wiping the skin of the right ear with a cotton swab. After 8 weeks, the mice were sacrificed. The serum was collected from each mouse to detect the levels of anti-double-stranded DNA (dsDNA) antibodies, immunoglobulin G (IgG), B cell activating factor (BAFF), and interleukin 6 (IL-6) using ELISA. The levels of serum creatinine were determined using a sarcosine oxidase method. Urine was collected to measure urinary protein concentration. Kidneys were collected and stained with hematoxylin and eosin (H&E) for evaluating histological changes. Results After IMQ treatment, the length and weight of spleen, levels of serum creatinine, anti-dsDNA antibodies, IgG, BAFF, IL-6, and urinary protein in the IMQ B6 group and IMQ S100A9-KO B6 group were significantly higher than those of the control groups. Lupus-like changes including increased glomerular volume and tubular epithelial swelling were observed in kidneys from the IMQ and IMQ S100A9-KO groups. However, compared with the IMQ B6 group, the IMQ S100A9-KO B6 group exhibited milder levels of serum and urine indicators as well as the lupus-like symptoms. Conclusion IMQ could induce lupus-like symptoms in both wild-type B6 mice and S100A9-KO B6 mice, but the lesions in S100A9 knockout mice are milder. Theses results suggested that S100A9 is involved in and promotes the pathogenesis of SLE.
Animals ; Lupus Erythematosus, Systemic/chemically induced* ; Female ; Calgranulin B/genetics* ; Mice, Knockout ; Mice, Inbred C57BL ; Phenotype ; Mice ; Interleukin-6/blood* ; Disease Models, Animal ; Antibodies, Antinuclear/blood* ; B-Cell Activating Factor/blood* ; Immunoglobulin G/blood* ; Kidney/pathology*

Objective To investigate the effects of cucurbitacin B (CucB) on alleviating skin lesions and inflammation in psoriasis mice via the cGAS-STING signaling pathway. Methods The expression of genes associated with the cGAS-STING signaling pathway in psoriatic lesions and non-lesional skin was analyzed, and hallmark gene set enrichment analysis was performed. The cytotoxicity of CucB on BMDMs was evaluated using the CCK-8 assay. The expression levels of genes and proteins related to the cGAS-STING signaling pathway, along with the secretion of inflammatory cytokines, were measured at different concentrations of CucB using quantitative PCR, Western blotting, and ELISA. Imiquimod-induced psoriasis BALB/c mice were divided into four groups: normal group, model group, low-dose CucB group [0.1 mg/ (kg.d)], and high-dose CucB group [0.4 mg/ (kg.d)], with five mice per group. PASI scoring was performed to assess the severity of psoriasis after 6 days of treatment, and HE staining was conducted to observe pathological damage. Meanwhile, the mRNA levels of inflammatory cytokines and their secretion were detected by qPCR and ELISA. Results Most cGAS-STING signaling-related genes were upregulated in lesional skin of psoriasis patients, and the hallmark gene set enrichment analysis revealed that the most significantly upregulated genes were primarily associated with immune response signaling pathways. CucB inhibited dsDNA-induced phosphorylation of interferon regulatory factor 3 (IRF3) and STING proteins in both bone-marrow derived macrophages(BMDMs) and THP-1 cells. CucB also suppressed dsDNA-induced mRNA expression of IFNB1, TNF, IFIT1, CXCL10, ISG15, and reduced the secretion of cytokines such as IFN-β, IL-1β, and TNF-α in THP-1 cells. In the imiquimod-induced psoriasis mouse model, CucB treatment reduced psoriatic symptoms, alleviated skin lesions, and attenuated inflammation. ELISA and qPCR results showed that CucB significantly reduced serum secretion levels of IL-6, TNF-α, and IL-1β, as well as the mRNA levels of IL23A, IL1B, IL6, TNF, and IFNB1. Conclusion CucB inhibits cytoplasmic DNA-induced activationc of the GAS-STING pathway. CucB significantly attenuates skin lesions and inflammation in IMQ-induced psoriatic mice, and the potential molecular mechanism may be related to the down-regulation of the cGAS-STING pathway.
Animals ; Psoriasis/pathology* ; Signal Transduction/drug effects* ; Membrane Proteins/genetics* ; Mice ; Nucleotidyltransferases/genetics* ; Disease Models, Animal ; Mice, Inbred BALB C ; Skin/metabolism* ; Triterpenes/therapeutic use* ; Humans ; Cytokines/metabolism* ; Inflammation/drug therapy* ; Male

Objective To generate and characterize natural killer cell (NK cell)-conditional Cd226 gene knockout mice using Cre-loxP technology, and to explore the role of CD226 on NK cells in alleviating intestinal inflammation in a murine model of ulcerative colitis (UC). Methods NK cell-conditional Cd226 gene knockout mice were generated by crossing loxP-flanked Cd226 mice with Ncr1-Cre mice via the Cre-loxP system. Polymerase chain reaction (PCR) and agarose gel electrophoresis were used for genotyping. A UC model was established by dextran sulfate sodium (DSS) induction. Flow cytometry was performed to analyze CD226 expression levels on NK cells and the infiltration of related immune cells in colon tissues. Hematoxylin-eosin (HE) staining was performed to assess the degree of colonic inflammation. Results DNA gel electrophoresis and flow cytometry confirmed the successful generation of NK cell-specific Cd226 knockout mice. After conditional knockout of Cd226 in NK cells, inflammation in the UC mouse model was alleviated. Flow cytometry results showed a reduced proportion of NK cells in peripheral blood and the colon lamina propria, while HE staining demonstrated attenuated inflammatory responses. Conclusion Specific knockout of Cd226 in NK cells mitigates intestinal inflammation in UC mice by reducing NK cell numbers and inhibiting their pro-inflammatory functions.
Animals ; Colitis, Ulcerative/pathology* ; Killer Cells, Natural/metabolism* ; Mice, Knockout ; T Lineage-Specific Activation Antigen 1 ; Antigens, Differentiation, T-Lymphocyte/genetics* ; Mice ; Disease Models, Animal ; Mice, Inbred C57BL ; Male

Objective To investigate the effects and underlying mechanisms of human placental chorionic plate-derived mesenchymal stem cells (hpcMSCs) on cognitive dysfunction, neuroinflammation, neuronal damage and synaptic plasticity in a mouse model of stroke. Methods A mouse model of middle cerebral artery occlusion (MCAO) was adopted. The mice were randomly divided into three groups: sham operation group, MCAO group and hpcMSCs treatment group, with seven mice in each group. The hpcMSCs treatment group received hpcMSCs transplantation on the 1st, 3rd and 10th day after MCAO. One month after MCAO, the cognitive ability of the mice was evaluated by Morris water maze and Y maze behavioral tests; the morphological changes and synaptic functions of hippocampal neurons were analyzed by HE staining, Nissl staining, Golgi staining and immunofluorescence staining techniques; the density and activation status of microglia was analyzed by Fluorescent labeling method; the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and IL-6 in brain tissue were analyzed by ELISA; the expressions of phosphorylated-mitogen-activated protein kinase kinase 1 (p-MEK1), phosphorylated-extracellular regulated protein kinase (p-ERK) and phosphorylated-cAMP-response element binding protein (p-CREB) and other proteins related to neuroprotection in the signal pathways were detected by Western blotting; and electrophysiological detection was performed using hippocampal slices in vitro. Results Compared with the MCAO group, mice in the hpcMSCs treatment group showed significant improvements, including improved cognitive ability, alleviated neuroinflammation (demonstrated by reduced microglial activation and decreased levels of inflammatory factors TNF-α, IL-1β and IL-6), and increased neuronal density with normalized morphology of neurons in the hippocampal CA1 region. The treatment group also demonstrated a significantly increased number of Nissl-positive cells and density of dendritic spines of hippocampal neurons, along with restored frequency of miniature excitatory postsynaptic potential (mEPSP). Moreover, hpcMSCs treatment significantly increased the expression levels of p-MEK1, p-ERK and p-CREB in the hippocampus. Conclusion Transplantation of hpcMSCs ameliorates cognitive dysfunction and hippocampal neuronal injury in stroke mice through the reduction of neuroinflammation, restoration of hippocampal neuronal function, promotion of synaptic plasticity and activation of the MEK/ERK/CREB signaling pathway. These findings suggest a new potential therapeutic approach for post-stroke neural repair.
Animals ; Hippocampus/physiopathology* ; Mice ; Cognitive Dysfunction/etiology* ; Mesenchymal Stem Cell Transplantation ; Male ; Neurons/metabolism* ; Stroke/metabolism* ; Humans ; Neuroinflammatory Diseases/therapy* ; Female ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Disease Models, Animal ; Mesenchymal Stem Cells/cytology* ; Mice, Inbred C57BL

Objective To explore the effects of Shuanglu Tongnao Formula on neuroinflammation in ischemic stroke (IS) rats via the P2X purinoceptor 7 receptor (P2X7R)/NLR family pyrin domain-containing 3 (NLRP3) pathway. Methods The rats were divided into five groups: the IS group, control group, Shuanglu Tongnao Formula group, P2X7R inhibitor brilliant blue G (BBG) group, and Shuanglu Tongnao Formula combined with P2X7R activator adenosine triphosphate (ATP) group, with 18 rats in each group. Except for the control group, rats in all other groups were used to construct an IS model using the suture method. After successful modeling, the drug was given once a day for 2 weeks. Neurological function scores and cerebral infarction volume ratios were measured in rats. Pathological examination of the ischemic penumbra brain tissue was performed. Immunofluorescence staining was used to quantify the proportions of microglia co-expressing both inducible nitric oxide synthase (iNOS) and ionized calcium-binding adapter molecule 1 (Iba1), as well as arginase 1 (Arg1) and Iba1, in the ischemic penumbra brain tissue. ELISA was used to detect tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interleukin 6 (IL-6) and IL-10 in the ischemic penumbra brain tissue. Western blotting was used to measure P2X7R, NLRP3, and IL-1β proteins in the ischemic penumbra brain tissue. Results Compared with the control group, the IS group showed disordered neuronal arrangement, nuclear condensation, and obvious infiltration of inflammatory cells in the ischemic penumbra; significantly elevated neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with reduced proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. Compared with the IS group, the Zhuang medicine Shuanglu Tongnao Formula and BBG groups demonstrated alleviated brain tissue damage; reduced neurological function scores, cerebral infarction volume ratios, proportions of microglia co-expressing iNOS and Iba1, and levels of TNF-α, IL-6, and P2X7R, NLRP3, IL-1β proteins; along with increased proportions of microglia co-expressing Arg1 and Iba1 and levels of TGF-β and IL-10. ATP reversed the effects of Zhuang medicine Shuanglu Tongnao Formula on microglial polarization and neuroinflammation in IS rats. Conclusion Zhuang medicine Shuanglu Tongnao Formula may promote the transformation of microglia from M1 type to M2 type by inhibiting the P2X7R/NLRP3 pathway, thereby improving neuroinflammation in IS rats.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Receptors, Purinergic P2X7/metabolism* ; Male ; Drugs, Chinese Herbal/pharmacology* ; Rats ; Ischemic Stroke/pathology* ; Rats, Sprague-Dawley ; Disease Models, Animal ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Brain Ischemia/drug therapy* ; Microglia/metabolism*

PURPOSE: To investigate the pathological changes of the synovium in mice with post-traumatic osteoarthritis (PTOA) treated with 4-octyl itaconate (4-OI) and evaluate the therapeutic effects of 4-OI. METHODS: In the phenotypic validation experiment, the mice were randomly divided into 3 groups: wild-type (WT) group, sham group, and destabilization of the medial meniscus (DMM) group. Through MRI, micro-CT, and histological analysis, it was determined that the DMM surgery induced a mouse PTOA model with significant signs of synovitis. At 12 weeks post-DMM surgery, synovial tissues from the DMM group and WT group mice were collected for ribonucleic acid sequencing analysis. In the 4-OI treatment experiment, mice were randomly divided into the sham group, DMM group, DMM + 4-OI (50 mg/kg) group, and DMM + 4-OI (100 mg/kg) group. Von Frey tests and open field tests were conducted at intervals during the 12 weeks following the DMM surgery. After 12 weeks of surgery, the efficacy of 4-OI treatment on PTOA in mice was evaluated using MRI, micro-CT, histological analysis, and quantitative real-time polymerase chain reaction. Finally, we utilized network pharmacology analysis to predict the mechanism of 4-OI in treating PTOA synovitis and conducted preliminary validation. Statistical analysis was performed using one-way ANOVA and the Kruskal-Wallis test. Difference was considered statistically significant at p < 0.05. RESULTS: The DMM surgery effectively induced a PTOA mouse model, which displayed significant symptoms of synovitis. These symptoms included a notable increase in both the number of calcified tissues and osteophytes (p < 0.001), an enlargement of the calcified meniscus and synovial tissue volume (p < 0.001), and thickening of the synovial lining layer attributable to M1 macrophage accumulation (p = 0.035). Additionally, we observed elevated histological scores for synovitis (p < 0.001). Treatment with 4-OI inhibited the thickening of M1 macrophages in the synovial lining layer of PTOA mice (p < 0.001) and reduced fibrosis in the synovial stroma (p = 0.004). Furthermore, it reduced the histological scores of knee synovitis in PTOA mice (p = 0.006) and improved the inflammatory microenvironment associated with synovitis. Consequently, this treatment alleviated pain in PTOA mice (p < 0.001) and reduced spontaneous activity (p = 0.003). Bioinformatics and network pharmacology analyses indicated that 4-OI may exert its therapeutic effects by inhibiting the differentiation of synovial Th17 cells. Specifically, compared to the lipopolysaccharide stimulation group, 4-OI reduced the levels of positive regulatory factors of Th17 cell differentiation (IL-1: p < 0.001, IL-6: p < 0.001), key effector molecules (IL-17A: p < 0.001, IL-17F: p = 0.004), and downstream effector molecules in the IL-17 signaling pathway (CCL2: p < 0.001, MMP13: p < 0.001). CONCLUSION 4-OI is effective in inhibiting synovitis in PTOA, thereby alleviating the associated painful symptoms.
Animals ; Synovitis/etiology* ; Mice ; Osteoarthritis/etiology* ; Disease Models, Animal ; Male ; Succinates/pharmacology* ; Mice, Inbred C57BL ; X-Ray Microtomography

PURPOSE: To investigate the protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on ischemic hypoxic injury of yorkshire brain tissue caused by traumatic blood loss. METHODS: This article performed a random controlled trial. Brain tissue of 7 yorkshire was selected and divided into the sub-low temperature anterograde machine perfusion group (n = 4) and the blank control group (n = 3) using the random number table method. A yorkshire model of brain tissue injury induced by traumatic blood loss was established. Firstly, the perfusion temperature and blood oxygen saturation were monitored in real-time during the perfusion process. The number of red blood cells, hemoglobin content, NA⁺, K⁺, and Ca²⁺ ions concentrations and pH of the perfusate were detected. Following perfusion, we specifically examined the parietal lobe to assess its water content. The prefrontal cortex and hippocampus were then dissected for histological evaluation, allowing us to investigate potential regional differences in tissue injury. The blank control group was sampled directly before perfusion. All statistical analyses and graphs were performed using GraphPad Prism 8.0 Student t-test. All tests were two-sided, and p value of less than 0.05 was considered to indicate statistical significance. RESULTS: The contents of red blood cells and hemoglobin during perfusion were maintained at normal levels but more red blood cells were destroyed 3 h after the perfusion. The blood oxygen saturation of the perfusion group was maintained at 95% - 98%. NA⁺ and K⁺ concentrations were normal most of the time during perfusion but increased significantly at about 4 h. The Ca²⁺ concentration remained within the normal range at each period. Glucose levels were slightly higher than the baseline level. The pH of the perfusion solution was slightly lower at the beginning of perfusion, and then gradually increased to the normal level. The water content of brain tissue in the sub-low and docile perfusion group was 78.95% ± 0.39%, which was significantly higher than that in the control group (75.27% ± 0.55%, t = 10.49, p < 0.001), and the difference was statistically significant. Compared with the blank control group, the structure and morphology of pyramidal neurons in the prefrontal cortex and CA1 region of the hippocampal gyrus were similar, and their integrity was better. The structural integrity of granulosa neurons was destroyed and cell edema increased in the perfusion group compared with the blank control group. Immunofluorescence staining for glail fibrillary acidic protein and Iba1, markers of glial cells, revealed well-preserved cell structures in the perfusion group. While there were indications of abnormal cellular activity, the analysis showed no significant difference in axon thickness or integrity compared to the 1-h blank control group. CONCLUSIONS Mild hypothermic machine perfusion can improve ischemia and hypoxia injury of yorkshire brain tissue caused by traumatic blood loss and delay the necrosis and apoptosis of yorkshire brain tissue by continuous oxygen supply, maintaining ion homeostasis and reducing tissue metabolism level.
Animals ; Perfusion/methods* ; Disease Models, Animal ; Brain Injuries/etiology* ; Swine ; Male ; Hypothermia, Induced/methods*