OBJECTIVETo study the influences on mandibular development after removing the outer cortex of mandibular body in childhood minitype pig.

METHODSSix childhood minitype pigs were selected as the experimental animals. The outer cortex of mandibular body measured as 3.0 cm x 1.5 cm was removed in one side, and the other side remained intact as the control. The changes of mandibular modality and occlusion relationship as well as the histological and biomechanical changes were studied 24 weeks after operation.

RESULTSThere was no obvious difference compared with the control side in the height of the mandibular ramus and the length of the mandibular body, However, lateral deviation occlusion was found in some animals. The body thickness was thinner than that of the control side, there were no obvious biomechanical and histological differences between the two sides.

CONCLUSIONSThere was less influence on the growth of mandibular bone after removing one side of the outer cortex of the mandibular body in childhood minitype pig. But further study should be done for the cause of the lateral deviation of the mandible in part of the animals.

Animals ; Female ; Male ; Mandible ; growth & development ; surgery ; Mandibular Condyle ; surgery ; Osteotomy ; adverse effects ; Swine ; Swine, Miniature

Computed tomography (CT) exams were conducted to determine the distribution of abdominal fat identified based on the CT number measured in Hounsfield Units (HU) and to measure the volume of the abdominal visceral and subcutaneous fat in minipigs. The relationship between the CT-based fat volumes of several vertebral levels and the entire abdomen and anthropometric data including the sagittal abdominal diameter and waist circumference were evaluated. Moreover, the total fat volumes at the T11, T13, L3, and L5 levels were compared with the total fat volume of the entire abdomen to define the landmark of abdominal fat distribution. Using a single-detector CT, six 6-month-old male minipigs were scanned under general anesthesia. Three radiologists then assessed the HU value of visceral and subcutaneous abdominal fat by drawing the region of interest manually at the T11, T13, L1, L3, and L5 levels. The CT number and abdominal fat determined in this way by the three radiologists was found to be correlated (intra-class coefficient = 0.9). The overall HU ranges for the visceral and subcutaneous fat depots were -147.47 to -83.46 and -131.62 to -90.97, respectively. The total fat volume of the entire abdomen was highly correlated with the volume of abdominal fat at the T13 level (r = 0.97, p < 0.0001). These findings demonstrate that the volume of abdominal adipose tissue measured at the T13 level using CT is a strong and reliable predictor of total abdominal adipose volume.
Animals ; *Body Composition ; Male ; Subcutaneous Fat, Abdominal/*radiography ; Swine ; Swine, Miniature/growth & development/*physiology ; Tomography, X-Ray Computed/*veterinary

Animals ; Animals, Newborn ; Hepatocyte Growth Factor ; chemistry ; physiology ; Liver ; chemistry ; Molecular Weight ; Swine ; Swine, Miniature ; Tissue Extracts ; chemistry

Somatic cell nucleus transfer (SCNT) has been considered the most effective method for conserving endangered animals and expanding the quantity of adult animal models. Bama miniature pigs are genetically stable and share similar biological features to humans. These pigs have been used to establish animal models for human diseases, and for many other applications. However, there is a paucity of studies on the effect of ear fibroblasts derived from different age of adult Bama miniature pigs on nucleus transfer (NT). The present study examined the NT efficiency of ear fibroblasts from fetal, newborn, 1-, 2-, 4-, 6-, 12-month-old miniature pigs by using trypan blue staining, flow cytometry and NT technique, etc., and the cell biological function and SCNT efficiency were compared between groups. The results showed that ear fibroblasts grew well after passage in each group. Spindle-shaped cells initially predominated, and gradually declined with increase of culture time and replaced by polygonal cells. Irregular cell growth occurred in the 2-month-old group and the elder groups. The growth curves of the ear fibroblasts were "S-shaped" in different age groups. The cell proliferation of postnatal ear fibroblasts, especially those from 2-, 4-, 6-, 12-month-old miniature pigs was significantly different from that of fetus ear fibroblasts (P<0.05 or P<0.01). Two-month- and 4-month-old ear fibroblasts had a significantly higher proportion of G1 stage cells (85% to 91%) than those at 6 and 12 months (66% to 74%, P<0.01). The blastocyst rate of reconstructed embryos originating from newborn, 1-, 2-, 4-month-old donor pigs was 6.06% to 7.69% with no significant difference from that in fetus fibroblast group (8.06%). It was concluded that <4-month-old adult Bama miniature pigs represent a better donor cell resource than elder pigs.
Animals ; Blastocyst ; physiology ; Cell Proliferation ; Cells, Cultured ; Ear ; embryology ; growth & development ; Fibroblasts ; cytology ; physiology ; transplantation ; Nuclear Transfer Techniques ; Swine ; Swine, Miniature ; anatomy & histology ; embryology ; growth & development

OBJECTIVESTo determine the efficacy of combined use of transmyocardial stent with gene therapy to treat acute myocardial infarction in porcine model.

METHODS24 Chinese mini swines have been divided into 4 groups randomly: group myocardial infarction (group MI n(1) = 6), group transmyocardial stent (group ST n(2) = 6), group vascular endothelial growth factor (group VEGF n(3) = 6), group transmyocardial stent and VEGF (group ST + VEGF n(4) = 6). In group MI, acute myocardial infarction animal model has been established by the ligation of the left descending coronary artery. In group ST, after the establishment of the model, 3 transmyocardial stents were implanted. In group VEGF, an expression plasmid containing the gene-encoding VEGF(165) (300 microg) was administered directly in the myocardium at 6 sites. In group ST + VEGF, both transmyocardial stents and expression plasmid containing the gene-encoding VEGF(165) are applied. 4 weeks later, the animals are sacrificed and echocardiography and pathological analysis have been done.

RESULTSThe density of blood vessel in group ST, VEGF and ST + VEGF are significantly higher than group MI. And capillary density in group ST + VEGF is the highest in these groups statistically. Expression of VEGF was detected in group ST, VEGF and ST + VEGF, but in group VEGF and ST + VEGF the level of expression are higher.

CONCLUSIONCombined use of transmyocardial stent with gene therapy has synthetic effect for the treatment of acute myocardial ischemia in porcine model and can significantly increase the vascular density.

Animals ; Combined Modality Therapy ; Disease Models, Animal ; Genetic Therapy ; Myocardial Infarction ; therapy ; Random Allocation ; Stents ; Swine ; Swine, Miniature ; Vascular Endothelial Growth Factor A ; genetics

OBJECTIVEVectors commonly used for therapeutic angiogenesis such as adenovirus and plasmid had their own limitations. Adenovirus-associated virus (AAV) is a relatively new but probably more ideal vector as it is safe and efficient. We will study the efficiency of recombinant AAV-2 mediated vascular endothelial growth factor165 gene transfer in inducing angiogenesis and arteriogenesis, in improving blood flow and myocardium function in a porcine chronic myocardial ischemic model.

METHODSChinese experimental minipigs underwent placement of a left circumflex artery aneroid constrictor. Five weeks later, electrocardiogram, coronary angiography and magnetic resonance imaging were performed to confirm occlusion of LCX or ischemia of myocardium in LCX territory. Coronary blood flow, myocardium perfusion and left ventricular wall function were also evaluated. Then the animals were randomized to treatment with rAAV2-VEGF(165) (1 x 10(12) virus genome) or administration of PBS, both by direct myocardial injection. Three and six months after therapy, the animals were evaluated with regard to expression of VEGF(165) Capillary density and arteriole density of the ischemic myocardium, coronary angiography, myocardial perfusion and left ventricular function were also assessed six months after therapy.

RESULTSFive weeks after aneroid occluder implantation, all the animals demonstrated complete or nearly complete occlusion of LCX and perfusion deficiency in LCX territory. Three months after therapy, expression of VEGF(165) mRNA and protein were higher in the VEGF than control group. The difference between the two groups diminished after six months. There was significant increase in capillary density (1404.06 +/- 250.48/mm(2) vs 976.88 +/- 344.79/mm(2), P < 0.05) and arteriole density (167.81 +/- 36.29/mm(2) vs 116.56 +/- 34.48/mm(2), P < 0.05) in VEGF group compared with control. Comparison of myocardial perfusion demonstrated marked differences between the two groups with significant improvement in animals treated with rAAV2-VEGF(165). No significant improvement in left ventricular function was seen in either the VEGF or control group.

CONCLUSIONSTransmyocardial delivery of rAAV2-VEGF(165) resulted in VEGF gene expression for at least three months and stimulated angiogenesis and arteriogenesis in porcine model of chronic myocardial ischemia. Myocardial perfusion was also improved after VEGF gene delivery.

Adenoviridae ; genetics ; Animals ; Disease Models, Animal ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Male ; Myocardial Ischemia ; therapy ; Swine ; Swine, Miniature ; Vascular Endothelial Growth Factor A ; genetics ; therapeutic use

OBJECTIVEThe study was to evaluate the microscopic changes on skin and soft tissue after repeated expansion for clinical work.

METHODSSix little pigs were divideded as: conventional expansion group, repeated expansion group, and blank control group. Histologic, ultrastructure and bFGF of the skin were observed and measured in each group after samples had been made.

RESULTSThe skin and soft tissue after repeated expansion were healthy on the whole. Compared with the conventional expansion group, there was more microscopic change in the repeated expansion group. Collagen fibers were injured evidently. Cells were injured slightly and proliferated much more, and moreover, they were more activated. The content of bFGF was more higher.

CONCLUSIONSThe skin and soft tissue after repeated expansion are healthy on the whole by more growth and more repair though repeated expansion may result in more injuries. So repeated expansion is safe and feasible.

Animals ; Dermatologic Surgical Procedures ; Female ; Fibroblast Growth Factor 2 ; metabolism ; Male ; Reconstructive Surgical Procedures ; Skin ; metabolism ; Swine ; Swine, Miniature ; Tissue Expansion ; methods

The purpose of this study is to define the appearance of normal epiphyseal and metaphyseal marrow and normal changes of marrow due to fatty conversion on Gadolinium (Gd)-enhanced MR Imaging. Unenhanced and enhanced T1-weighted MR imaging were performed in proximal and distal femoral ends of 8 healthy piglets at the ages of 2, 4, 6 and 8 weeks, respectively. The changes with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow with age were examined. The correlation of MRI characteristics with histological findings was studied. Our study showed that marrow of the metaphysis and of periphery of the 2nd ossification center were well vascularized hematopoietic marrow and had great enhancements. The enhancement ratio of metaphysis was greater than that of epiphyseal marrow and both enhancement ratios degraded gradually with age. The central regions of the epiphyseal ossification center and of the diaphysis were of fatty marrow and had little enhancement. It is concluded that on Gd-enhanced MR imaging the hematopoietic marrow of metaphysis and of periphery of the 2nd ossification center had greater enhancement than that of fatty marrow of central region of the 2nd ossification center. All of their enhancements decreased gradually with age.
Epiphyses/*anatomy & histology ; Femur/anatomy & histology ; Femur/*growth & development ; Gadolinium/*diagnostic use ; Growth Plate/*anatomy & histology ; Growth Plate/blood supply ; Growth Plate/growth & development ; Image Enhancement ; Magnetic Resonance Imaging ; Swine ; Swine, Miniature

BACKGROUNDCarbon dioxide (CO2) laser soldering is an alternative technique for tissue bonding. Basic fibroblast growth factor (bFGF) and transforming growth factor β(1) (TGFβ(1)) are two key factors for wound healing. This study was performed to demonstrate the efficacy of CO2 laser soldering for dural reconstruction and the effect of bFGF and TGFβ(1) on healing.

METHODSIn Part I, 10 minipigs were randomized into two equal groups. Dural defects were reconstructed by conventional fibrin glue bonding (group I(a)) or CO2 laser soldering (group I(b)). The reconstructed dura was subjected to burst pressure (BP) measurement and immunohistochemical staining after 1 week. In Part II, 36 minipigs were randomized into three equal groups. Dural reconstruction was achieved by CO2 laser soldering. Exogenous bFGF (group II(b)) or TGFβ(1) (group II(c)) was administered while group II(a) served as a control group. The specimens were subjected to BP measurement after 1, 2, 3, and 4 weeks, respectively.

RESULTSIn Part I, the dura specimens displayed positive staining of only bFGF in group I(a) and of both bFGF and TGFβ(1) in group I(b). Group I(b) showed higher BP than group I(a) ((98.00 ± 21.41) mmHg vs. (70.80 ± 15.09) mmHg, respectively; P < 0.05). In Part II, BP of group II(c) was significantly higher than that of group II(a) (P < 0.01). The BP of group II(a) trended toward stabilization after 3 weeks of growth, while that of groups II(b) and II(c) trended toward stabilization after 2 weeks of growth.

CONCLUSIONSCO2 laser soldering is a reliable technique for dural reconstruction. The superior healing of dural reconstruction by CO2 laser soldering may be related to higher expression of bFGF and TGFβ(1), and CO2 lasers may stimulate their secretion. Exogenous bFGF or TGFβ(1) may improve healing by shortening the wound healing time, and exogenous TGFβ(1) may improve the tensile strength.

Animals ; Dura Mater ; drug effects ; surgery ; Female ; Fibrin Tissue Adhesive ; chemistry ; Fibroblast Growth Factor 2 ; therapeutic use ; Immunohistochemistry ; Lasers, Gas ; Male ; Swine ; Swine, Miniature ; Transforming Growth Factor beta1 ; therapeutic use ; Wound Healing ; drug effects

BACKGROUNDThe cardioprotective effects of soluble receptor for advanced glycation end-products (sRAGE) have not been evaluated in large animals and the underlying mechanisms are not fully understood. This study aimed to evaluate the effects of intra-coronary administration of sRAGE on left ventricular function and myocardial remodeling in a porcine model of ischemia-reperfusion (I/R) injury.

METHODSTen male minipigs with I/R injury were randomly allocated to receive intra-coronary administration of sRAGE (sRAGE group, n = 5) or saline (control group, n = 5). Echocardiography was performed before and 2 months after infarction. Myocardial expression of transforming growth factor (TGF)-beta1 was determined by immunohistochemistry and fibrosis was evaluated by Sirius red staining.

RESULTSAs compared with the baseline values in the control animals, left ventricular end-diastolic volume (from (19.5 +/- 5.1) to (32.3 +/- 5.6) ml, P < 0.05) and end-systolic volume (from (8.3 +/- 3.2) to (15.2 +/- 4.1) ml, P< 0.05) were significantly increased, whereas ejection fraction was decreased (from (61.6 +/- 13.3)% to (50.2 +/- 11.9)%, P < 0.05). No obvious change in these parameters was observed in the sRAGE group. Myocardial expression of TGF-beta1 was significantly elevated in the infarct and non-infarct regions in the control group, as compared with sRAGE group (both P< 0.01). Fibrotic lesions were consistently more prominent in the infarct region of the myocardium in the control animals (P < 0.05).

CONCLUSIONIntra-coronary sRAGE administration attenuates RAGE-mediated myocardial fibrosis and I/R injury through a TGF-beta1-dependent mechanism, suggesting a clinical potential in treating RAGE/ligand-associated cardiovascular diseases.

Animals ; Echocardiography ; Fibrosis ; Humans ; Male ; Myocardial Infarction ; etiology ; Myocardium ; metabolism ; pathology ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; administration & dosage ; Reperfusion Injury ; Swine ; Swine, Miniature ; Transforming Growth Factor beta1 ; genetics ; Ventricular Remodeling