Segmental innervation of the Göttingen minipig hind body. An electrophysiological study

The Göttingen minipig is being used increasingly in biomedical research. The anatomical structure of the porcine peripheral nervous system has been extensively characterized, but no equivalent to the dermatome map, which is so valuable in human neurophysiological research, has been created. We characterized the medullar segmental skin and muscle innervations of the minipig hind body, using neurophysiological methodology. Six adult minipigs underwent unilateral laminectomy from L2 to S3, exposing the nerve roots. The skin of the hind part of the body was divided into 36 predefined fields, based on anatomical landmarks for consistent reproducibility. We recorded the evoked potential in each exposed nerve root L2‐S3 for cutaneous stimulation of each skin field, mapping the sensory innervation of the entire hind body. We subsequently recorded the motor response in seven predefined muscles during sequential stimulation of the L2‐S3 nerve roots. We obtained a clear sensory evoked potential in the nerve roots during stimulation of the skin fields, allowing us to map the sensory innervation of the minipig hind body. Neurophysiological data from skin stimulation and muscle recordings enabled us to map the sensory innervation of the Göttingen minipig hind body and provide information about muscular innervation. The skin fields were sensory innervated by more than one root. The muscles each had one dominant root with minor contribution from neighboring roots. This is consistent with experimental data from human studies.     

Comparison of the osteogenic capacity of minipig and human bone marrow‐derived mesenchymal stem cells

Minipigs are a recommended large animal model for preclinical testing of human orthopedic implants. Mesenchymal stem cells (MSCs) are the key repair cells in bone healing and implant osseointegration, but the osteogenic capacity of minipig MSCs is incompletely known. The aim of this study was to isolate and characterize minipig bone marrow (BM) and peripheral blood (PB) MSCs in comparison to human BM‐MSCs. BM sample was aspirated from posterior iliac crest of five male Göttingen minipigs (age 15 ± 1 months). PB sample was drawn for isolation of circulating MSCs. MSCs were selected by plastic‐adherence as originally described by Friedenstein. Cell morphology, colony formation, proliferation, surface marker expression, and differentiation were examined. Human BM‐MSCs were isolated and cultured from adult fracture patients (n = 13, age 19–60 years) using identical techniques. MSCs were found in all minipig BM samples, but no circulating MSCs could be detected. Minipig BM‐MSCs had similar morphology, proliferation, and colony formation capacities as human BM‐MSCs. Unexpectedly, minipig BM‐MSCs had a significantly lower ability than human BM‐MSCs to form differentiated and functional osteoblasts. This observation emphasizes the need for species‐specific optimization of MSC culture protocol before direct systematic comparison of MSCs between human and various preclinical large animal models can be made. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1019–1025, 2012     

小型猪慢性心力衰竭模型研究进展

慢性心力衰竭是一种复杂的心血管综合征,建立合适的慢性心力衰竭动物模型是研究慢性心力衰竭发病机制及相关药物治疗的关键。小型猪因其在病理生理、解剖结构等方面更接近人类,故建立小型猪慢性心力衰竭模型已成为研究热点。目前较成熟的小型猪慢性心力衰竭模型制备方法主要有心肌梗死型、前负荷过载型、后负荷过载型、药源型和心动过速型等。     

体外培养版纳微型猪近交系骨髓基质干细胞的生物学特性

目的　分离培养成年版纳微型猪近交系骨髓基质干细胞并探讨其体外生物学特性。方法　成年版纳微型猪骨髓基质干细胞通过密度梯度离心法分离获得 ,用含 15 %小牛血清的 DMEM在 37℃ ,5 % CO2 条件下培养 ;通过克隆生长特性、特异抗原表达和成骨分化能力鉴定其干细胞特性。结果　版纳微型猪近交系骨髓分离获得的基质干细胞具有多种形状 ,但主要为梭形。其具有很强的增殖能力 ,在体外培养条件下可以观察到明显的克隆样生长 ;表达 SH2、SH3、SH4、SB10和 SB2 1等骨髓基质干细胞的特异标记 ;经成骨添加剂诱导培养之后能分化为成骨细胞 ,碱性磷酸酶活性增强并具有细胞外基质矿化能力。结论　成年版纳微型猪近交系骨髓来源的基质干细胞具有干细胞的一般生物学特性     

New surgical technique reduces the susceptibility artefact at air–tissue interfaces on in vivo cerebral MRI in the Göttingen minipig

Advanced and exclusive software solutions are offered to reduce susceptibility artefacts on MRI echo-planar sequences. We present a straightforward surgical technique to reduce the cortical distortion and signal loss that normally occur using diffusion tensor imaging (DTI) of the Göttingen minipig brain. Pronounced pneumatisation of the minipig cranium causes considerable susceptibility artefacts at the air/tissue interface around the frontal sinuses. Five Göttingen minipigs had burr holes drilled through the outer lamina of the skull bilaterally at the level of bregma. The underlying frontal sinuses were filled with a suspension of an MRI-compatible alginate. DTI was obtained before and after placing the medium in the sinus, quantifying the change using mutual information and Wilcoxon's rank-sum test. Fibertracking algorithms were applied to visualize the effect of treatment. We showed that the susceptibility artefacts were reduced at the air, bone and brain interfaces and that major cortical fiberbundles could be reliably visualized. This study demonstrated that DTI fibertracking of cortical bundles in experimental animals with extensive skull pneumatisation is feasible even when advanced software is unavailable.     

Lower cardiovagal tone and baroreflex sensitivity associated with hepatic insulin resistance and promote cardiovascular disorders in Tibetan minipigs induced by a high fat and high cholesterol diet

Aims

A long-term high-fat/cholesterol (HFC) diet leads to hepatic insulin resistance (IR), which is associated with autonomic dysfunction and cardiovascular diseases risk increasing. However, whether this occurs in Tibetan minipigs remains unknown. We tested that a long-term HFC diet caused hepatic IR and promote cardiovascular disorders in Tibetan minipigs, and are associated with the reduction of cardiovagal tone and baroreflex sensitivity (BRS).

腰椎穿刺术在小型猪的应用

目的 探索小型猪腰椎穿刺技术的可行性和注意事项,测定脑脊液的生理指标.方法 10只小型猪全身麻醉后行腰椎穿刺术,测量颅内压力并留取标本.术毕麻醉维持4h,术后1周每天观察动物并记录动物的行为学(包括摄食能力、活动能力、步态),神经损害体征,穿刺局部情况,采用改良Tarlov评分标准评价其神经功能,改良的切口愈合等级评分标准评价其穿刺局部情况.结果 穿刺术后动物行为学均于当天恢复正常.小型猪颅内压均值为(130.73±38.299)mmH2O,其脑脊液外观清亮,细胞总数、白细胞、蛋白、氯化物、糖的平均水平分别为(2.73±2.314)/μL、(1.00±1.363)/μL、(27.87±9.257)mg/dL、(120.47±4.998)mmol/L、(2.60±0.629)mmol/L.观察期间,小型猪穿刺点局部愈合良好,无腰穿相关并发症.结论 小型猪腰椎穿刺术操作简便,安全性好,可行性强.脑脊液的生理指标为相关研究提供了参考.     

西藏小型猪胰岛细胞体外分离和纯化方法

的确定成体西藏小型猪胰岛细胞体外分离、纯化的理想条件,为异种移植治疗糖尿病提供高质量的胰岛细胞。方法对比不同质量浓度的胶原酶（1mg／ml,2mg／ml,3mg／ml,4mg／m1）和同一质量浓度不同时间点（0min,15min,30min,45min,60min,75min,90min）分离获得胰岛细胞的数量和效果;使用Ficoll400密度梯度离心、淋巴分离液分离、离心和静置4种方法纯化胰岛细胞悬液,比较最终收集到的胰岛细胞数量和效果;用DTZ染色计算胰岛细胞的纯度;用AO／PI染色计算胰岛细胞存活率。结果确定了不同质量浓度的胶原酶获取胰岛细胞的最佳时间,胶原酶lmg／ml和2mg／ml组为45min,3mg／ml和4mg／ml组为30min,各组在最佳时间点获得胰岛细胞的数量最多的为1mg／ml组,胰岛细胞形态完整;4种纯化方法中,收集的胰岛细胞数量由多到少依次为静置组〉Ficoll400密度梯度离心组〉离心组〉淋巴分离液离心组。经AO／PI染色后检测胰岛细胞的存活率为95．00％以上。结论在组织块剪碎消化的情况下,胶原酶质量浓度lmg／ml、消化时间45min的分离条件可获得数量较多的胰岛细胞,Ficoll400密度梯度离心的纯化手段收集到的胰岛细胞效果最好。     

Minipigs as models in drug discovery

ABSTRACT

Introduction: Influenza continues to be a major public health concern. Antivirals play an important role in limiting the burden of disease and preventing infection and/or transmission. The developments of such agents are heavily dependent on pre-clinical evaluation where animal models are used to answer questions that cannot be easily addressed in human clinical trials. There are numerous animal models available to study the potential benefits of influenza antivirals but each animal model has its own pros and cons.

Areas covered: In this review, the authors describe the advantages and disadvantages of using mice, ferrets, guinea pigs, cotton rats, golden hamsters and non-human primates to evaluate influenza therapeutics.

Expert opinion: Animals used for evaluating influenza therapeutics differ in their susceptibility to influenza virus infection, their ability to display clinical signs of illness following viral infection and in their practical requirements such as housing. Therefore, defining the scientific question being asked and the data output required will assist in selecting the most appropriate animal model.