The production of miniature animals has been suggested for use in organ transplantation. At present, many of the studies about application of animal organs to human have been focused on pigs because of the number of advantages involved and due to their similarities with human. However, a physiological analysis of the organs to be transplanted has not yet been carried out. Therefore, this study analyzed whether or not there were physiological and morphological differences in the hearts of conventionallyreared pigs and micropigs. In this study, the morphological and physiological functions of the heart were examined using radiographic and echocardiographic equipment. In the lateral radiographic view, the heart of the micropig has a larger cardiac long axis : short axis ratio than does the conventional pig, but the difference in the vertebral heart score was not significant. In addition, there were no morphological differences on the X-ray fluoroscopic view. There were no differences in echocardiographic values, except for several values in the left ventricle traces. Overall, it is expected that the values measured in this study will contribute to understanding of the physiological characteristics of micropigs.
Animals ; Echocardiography/veterinary ; Fluoroscopy/veterinary ; Heart/*physiology/*radiography ; Stroke Volume/physiology ; Swine ; Swine, Miniature

OBJECTIVETo investigate the local changes of biomechanics after osteotomy of mandibular outer cortex in body and angle areas.

METHODSSix minitype pigs at the age of 8 to 12 months were selected. The mandibular outer cortex that involves angle and part of body was removed in one side. The animals were killed 24 weeks after operation. Bone strut was taken from mandibular angle region bilaterally and sent for biomechanical test

RESULTSThere was no biomechanical difference between the two angle areas of experimental and normal sides 24 weeks after mandibular outer cortex osteotomy (maximum load P > 0.05, rigidity P > 0.05).

CONCLUSIONSMandibular outer cortex osteotomy had no influence on local biomechanics.

Animals ; Biomechanical Phenomena ; Female ; Male ; Mandible ; physiology ; surgery ; Osteotomy ; Postoperative Period ; Swine ; Swine, Miniature

BACKGROUNDMiniature pig (minipig) is increasingly used as a large animal model for a variety of biomedical studies. Little information is available in the literature on anatomy, histology and sialograghy of the submandibular gland of the minipig. The purpose of this study was to characterize the morphology of a miniature pig's (minipig) submandibular gland as a large animal model for further biomedical studies.

METHODSFive minipigs were subjected to sialographic, anatomic, histologic, histochemical and ultrastructural evaluations for submandibular glands.

RESULTSSialograms showed a long, horizontal main excretory duct and a pear-shaped gland located inferoposterior to the angle of the mandible. The submandibular glands lied superficial to the suprahyoid, and infrahyoid muscle groups, and were covered by the inferior portion of the parotid gland. The submandibular glands were characterized by a mixed parenchyma of mucous and serous secretory acini. Alcian blue (AB) staining and periodic acid-Schiff (PAS) reactions demonstrated that minipig submandibular glands synthesized and secreted acid mucous substances by serous cells and polysaccharide, and neutral mucous substances, by mucous cells.

CONCLUSIONThe submandibular gland of the minipig is considered a useful large salivary gland animal model for biomedical studies.

Animals ; Female ; Histocytochemistry ; Submandibular Gland ; chemistry ; cytology ; physiology ; ultrastructure ; Swine ; Swine, Miniature ; anatomy & histology

OBJECTIVETo investigate the relationship between the survival rate of expanded flap and expansion volume.

METHODSThe minipigs were used and divided into 5 groups according to different expansion volume of the tissue expanders: injection to full content, 50% over content, 100% over content, 0% content and normal control. In each animal, 4 expanders (100 ml) were designed to be implanted at the bilateral side of back. Normal skin control was also designed at the back. The skin histologic change and flap survival rate were detected and analyzed when the expansion volume changed.

RESULTSThe flap survival rate increased along with the increase of expansion volume. While the survival rate decreased when the expansion volume was exceeded to 100% over content.

CONCLUSIONSIn soft tissue and skin expansion, the flap survival rate and the flap size increased as the expansion is over the standard volume, while over-expansion to 100% over content may cause decreased survival rate of expanded flap.

Animals ; Back ; Graft Survival ; Surgical Flaps ; physiology ; Swine ; Swine, Miniature ; Tissue Expansion ; Tissue Expansion Devices

Spectral waveform analysis of blood flow velocity in the major arteries of six healthy, conscious immature micropigs was determined using Doppler ultrasonography. Doppler spectral tracings were recorded from the external iliac artery, femoral artery, and renal arcuate artery. Tracings were also taken from three parts of the common carotid artery and two parts of the abdominal aorta. Spectral Doppler parameters included peak systolic velocity, early diastolic velocity, peak systolic velocity-to-end diastolic velocity ratio, resistive index, and pulsatility index. In addition, the diameter of major arteries and indirect blood pressure were measured. These results from spectral Doppler analysis in major arteries may be useful as reference ranges in the future studies of vascular hemodynamics in immature micropigs.
Animals ; Arteries/physiology/*ultrasonography ; Blood Flow Velocity/physiology/*veterinary ; Male ; Swine ; Swine, Miniature ; Ultrasonography, Doppler, Color/*veterinary

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

OBJECTIVETo explore the effect of burying testis in thigh pocket on spermatogenesis.

METHODSGuizhou miniature male pigs at child-bearing period were randomly divided to receive operation of scrotum incision and dissection with the testis burying in thigh pocket (experimental group) or without (control group). 3 months later, testis biopsy was performed on 2 pigs from each group for pathological examination. Then every male pig from both experimental (n = 6) and control group (n = 6) got a mating partner and lived together for 3 months. The fertility of the male pigs was observed. 6 months after operation, testis biopsy was performed again on all the animals from both the groups.

RESULTSBoth at 3 months and 6 months after operation, the pathological examination showed the spermatogenic cells of all stage in contorted seminiferous tubules markedly decreased with no mature sperm in experimental group, while normal spermatogenic cells with mature sperm in control group. After the male pigs lived with mating partners for 3 months, no female pigs staying with the experimental group became pregnant, but the male pigs in control group had a normal fertility.

CONCLUSIONSBurying testis in thigh pocket impedes spermatogenesis in the miniature male pig. So burying testis in thigh pocket is not recommended for patients with scrotum skin defect who wish to remain fertile.

Animals ; Female ; Fertility ; Male ; Pregnancy ; Pregnancy Rate ; Scrotum ; Skin ; injuries ; Spermatogenesis ; Swine ; Swine, Miniature ; Testis ; physiology ; Thigh ; surgery

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

OBJECTIVETo study the method of preparing the hollow fiber bioreactor for culturing pig hepatocytes.

METHODSHepatocytes were isolated from experimental suckling minipigs by two-step perfusion with collagenase, and seeded onto hollow fiber bioreactor, then cultured with an artificial capillary cell culture system. The albumin-excretion, lidocaine-transforming rate, lactate dehydrogenase (LDH) release and the cell viability in bioreactors were examined.

RESULTSThe porcine albumin could be detected by SDS/PAGE on the 2nd, 4th, 6th day. The rates of lidocaine-transforming ranged from 89.6% to 96.1%. The release of LDH into the culture medium increased from (23.7+/-4.6) U/L to (127.8+/-17.4) U/L (F=39.582, P<0.01) during the experiments, and the viability of pig hepatocytes in hollow fiber bioreactor reduced from 95.8%+/-0.3% to 83.8%+/-4.7% (t=5.135, P<0.01).

CONCLUSIONThe hollow fiber bioreactor for culturing pig hepatocytes can be prepared by artificial capillary cell culture system, which provides a certain liver-specific function in 1 week.

Animals ; Bioreactors ; Biotechnology ; Cells, Cultured ; Female ; Hepatocytes ; cytology ; Liver ; cytology ; physiology ; Liver, Artificial ; Male ; Swine ; Swine, Miniature

The purpose was to optimize the vitrification for porcine embryos cryopreservation. Blastocyst/Morula (5-6th day-embryos) were collected from superovulated Bama mini-pigs (sows/gilts). We compared different cryopreservation methods, cryopreservation tools, thining of zona pellucida (ZP) and recipient breeds on the efficiency of porcine embryo cryopreservation. The results showed that: in embryo survival rate and blastocyst cell number, there were no significant differences between cryopreservation method I [embryos were vitrified by two step method with open pulled straw (OPS) and glass micropipette (GMP) in solution 1 (TCM199 + 20% FBS + 10% EG + 10% DMSO) for 3 min, and solution 2 (TCM199 + 20% FBS + 20% EG + 20% DMSO + 0.4 mol/L SUC) for 1 min, stored in liquid nitrogen] and method II[Blastocysts were cultured for 25 min in NCSU23 + 7.5 microg/mL cytochalasin B, centrifuged at approximately 13 000 xg for 12-13 min, and recovered back into pNCSU23. They were then equilibrated for 5 min in 2 mol/L ethylene glycol in pNCSU23, washed quickly in the vitrification medium, 8 mol/L ethylene glycol, 7% polyvinylpyrrolidone (PVP) in pNCSU23, loaded into OPS/GMP, and plunged into liquid nitrogen]. GMP vitrification method was more suitable and efficient than OPS method (P < 0.05) in embryo survival rate (83.8% vs 77.6%) and blastocyst cell number (53.1 vs 47.5) after thawing. Thining of ZP did not increase the survival rate, but significantly improved blastocyst cell number in the survival blastcysts (60.1 and 46, P < 0.01). Local pig breeds (Fengjing sows) were more suitable as recipients for embryo transfer of vitrified/warmed blastcysts, which can improve pregnant rate and embryo efficiency.
Animals ; Blastomeres ; cytology ; Cryopreservation ; methods ; veterinary ; Embryo Transfer ; veterinary ; Embryo, Mammalian ; Swine ; Swine, Miniature ; Vitrification ; Zona Pellucida ; physiology