Animals ; Dentistry ; Swine ; Swine, Miniature

All endoureteromy procedures have in common the use of a ureteral stent as post-procedure However, the optimal stent size necessary to promote satisfactory healing is not known. Herein we compared healing of an endoureterotomy over a 7 Fr indwelling ureteral stent (IUS) with healing over a 14 Fr endopyelotomy stent( ES). A mid-ureteral stricture was created in each of 25 anesthetized, female minipigs using a retrograde electrified stone basket. Six weeks later, retrograde ureterograms(RU) revealed a stricture in 24 pigs ; ureteral incision was performed with a 24 Fr cutting balloon device. Twenty pigs were randomized to receive a 7 Fr IUS or a 14 Fr ES; 4 control pigs were performed to confirm proper stent position and the stents were removed. At 3 months. RU was repeated and the ureters were grossly examined and harvested for histological studies. Two pigs in each group had recurrent strictures. Despite a 50 years history of endoureterotomy, optimal stent size remains an endourologic unknown. Our study represents the first attempt at directly comparing stents of different size in an in vivo ureteral stricture model. There is no significant difference between 7 Fr and 14 Fr stents.
Constriction, Pathologic* ; Female ; Humans ; Stents* ; Swine ; Swine, Miniature ; Ureter*

OBJECTIVETo evaluate the effects of a solitary megadose protocol of ionizing radiation (IR) to parotid gland on the structured and function changes of bilateral parotid glands in miniature pig.

METHODSFourteen minipigs were subjected to either 15 or 20 Gy to one parotid gland with a linear accelerator, while another four minipigs served as non-IR controls. Salivary flow rates and salivary chemistries were measured pre-IR, and 4 and 16 weeks post-IR. A quantitative assessment of gland weight and acinar area, and detailed serum chemistry and hematological analyses, were also performed.

RESULTSParotid gland weights were significantly decreased in the 15 and 20 Gy groups at 4 and 16 weeks post-IR. The acinar cell area in glands of both IR groups was significantly reduced. Parotid flow rates decreased by 60% with 15 Gy at 16 weeks post-IR. In the 20 Gy group, salivary flow rates were reduced by 80% at 16 weeks post-IR. Additionally, parotid flow rates significantly reduced in contralateral glands with 20 Gy at 16 weeks, while structure and weight did not changes in parotid glands.

CONCLUSIONStructural changes in salivary gland parenchyma occurred relatively early after IR, while the alterations in salivary output were relatively delayed. Further, reductions in salivary flow were not proportional to acinar cell area loss. There isn't a significant structured change of contralateral glands, but significant reduction of parotid flow rate at this time.

Animals ; Parotid Gland ; radiation effects ; Swine ; Swine, Miniature

BACKGROUNDThe aim of this research was to evaluate the feasibility and efficacy of absorbable bandage wrapping in the treatment of cases of severe liver trauma.

METHODSElectric firecrackers were detonated in 16 miniature swine to produce a severe blast liver injury. After fluid resuscitation, the animals were randomly divided into two groups (n = 8 each) and were either treated with absorbable bandage wrapping of the injured lobe of liver (Group B) or hepatic lobectomy (Group H). Time to hemostasis, blood loss during the treatment period, and other parameters were compared, including postoperative serum total bilirubin (TB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST).

RESULTSBlood loss during the treatment period was significantly lower in Group B than that in Group H ((81.3 ± 26.0) ml vs. (130.8 ± 29.5) ml, P = 0.0031). Serum AST and ALT were transiently increased post-surgically. These transient increases were significantly higher in Group B. No difference in time to hemostasis was noted ((8.70 ± 2.27) minutes vs. (10.28 ± 1.93) minutes, P = 0.1559) in Groups B and H, respectively. Two pigs were humanely euthanized 28 days post-surgically and the wrapped liver lobes appeared atrophies. Microscopically, there was evidence of emerging and mature fibrous tissue.

CONCLUSIONAbsorbable bandage wrapping is both feasible and effective in the treatment of severe blast liver injury.

Animals ; Bandages ; Female ; Liver ; injuries ; surgery ; Male ; Swine ; Swine, Miniature

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 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

OBJECTIVETo establish a neonatal Tibet minipig model of hypoxic-ischemic encephalopathy and evaluate the magnetic resonance imaging (MRI) manifestations and pathological findings.

METHODSSix neonatal (1-3 days old) Tibet minipigs were randomized into model group (n=4) and control group (n=2). In model group, hypoxic-ischemic encephalopathy was induced by surgical ligation of the bilateral carotid artery followedimmediately by hypoxic exposure in a hypoxia chamber for 1 h. ESWAN was performed at 2 h, 24 h, 3 days and 5 days after induction of HIE or at 2 h after sham surgery in the control animals to evaluate the brain damage. Conventional MRI scans (T2FLAIR, T2WI, and DWI) were also performed at 24 h after the modeling.

RESULTSIn the neostriatum, values of T(2)*-weighted MRI increased and reached the peak level at 3 days post-injury (P<0.05). Subcortical white matter T(2)* values reached the peak level at 24 h (P<0.05). Neostriatum R(2)* values were at the lowest level at 3 days (P<0.05). Magnitude values were significantly increased after the model establishment (P<0.05). DWI showed multiple mild focal high signals in the bifrontal subcortical white matter and bilateral neostriatum; T2FLAIR showed slightly increased signal; T2WI showed no obvious abnormalities. SWI showed dilated medulla veins adjacent to the bilateral lateral ventricles and basal ganglia. In the early stage of HIE, brain pathologies were characterized mainly by edema and venous congestion with occasional focal necrosis and hemosiderin deposition.

CONCLUSIONESWAN sequence is capable of detecting bleeding and brain edema, and T(2)*, R(2)*, and magnitude values can be used to estimate the changes of brain damage following HIE.

Animals ; Disease Models, Animal ; Hypoxia-Ischemia, Brain ; diagnosis ; pathology ; Magnetic Resonance Imaging ; Swine ; Swine, Miniature ; Tibet

OBJECTIVETo study scutellarin starch microspheres' permeability through nasal mucosa of different animals in vitro.

METHODThe Franz diffusion cell method was used to experiment the permeability test (n = 4), taking fresh nasal mucosa of dog, swine and domestica in vitro as permeation barrier separately, with scutellarin starch microspheres (scutellarin 0.25 mg) above them, and blank pH 6.8 PBS as absorption liquid to detemine the scutellarin by HPLC.

RESULTThe permeability coefficient of scutellarin starch microspheres through nasal mucosa of dog, swine and domestica in vitro were (5.295 +/- 0.637) x 10(-3) (4.065 +/- 1.140) x 10(-3), (1.855 +/- 0.150) x 10(-3) cm x mL(-1) separately. The permeability coefficient order of scutellarin starch microspheres through nasal mucosa of different animals in vitro is dog > swine > domestica, and there are significant differences between the permeability coefficient of scutellarin starch microspheres through nasal mucosa of dog, swine in vitro, and that through nasal mucosa of swine and domestica in vitro.

CONCLUSIONDrugs in scutellarin starch microspheres could permeate through the above-mentioned nasal mucosa in vitro. There might be different permeability coefficient among different species.

Animals ; Apigenin ; pharmacokinetics ; Dogs ; Glucuronates ; pharmacokinetics ; Microspheres ; Nasal Mucosa ; metabolism ; Permeability ; Starch ; pharmacokinetics ; Swine ; Swine, Miniature

OBJECTIVETo evaluate the diagnostic value of dobutamine stress magnetic resonance imaging (MRI) for myocardial viability.

METHODSTen male miniswines underwent left ventriculography and coronary angiography, followed by stenosis of the left circumflex coronary artery (LCX) using ameroid constrictor. More than one month later, left ventriculography and coronary angiography were performed again, followed by cine-MRI at rest and during stress with incremental dose of dobutamine 5 - 20 micro g.kg(-1).min(-1). Traditional and/or breath-hold cine-MRI were used to evaluate regional left ventricular wall motion, corresponding to basal, midventricular and apical short-axis tomograms. Regional wall motion score index (WMSI) was calculated. The miniswines were finally sacrificed for pathological examination. Triphenyl tetrazolium chloride (TTC) delineated myocardial infarction. Microscopy was used to identify myocardial cellular changes.

RESULTSOne pig died, one pig suffered from aneurysm and another showed no negative findings. The other seven pigs were found with hypokinetic (n = 4) or akinetic (n = 3) myocardial regions related to stenosed LCX. Their mean WMSI at rest for the lateral and posteroinferior walls (ischemic regions) of the left ventricle was 2.27 +/- 0.32, as compared with 1.00 +/- 0.00 (P < 0.01) for the corresponding nonischemic anteroseptal regions. Further, the mean WMSI for the ischemic regions was 2.27 +/- 0.32 at rest compared with 1.40 +/- 0.39 (P < 0.01) at the dose of dobutamine 5 micro g.kg(-1).min(-1). However, the mean WMSI at the doses of dobutamine 10 and 20 micro g.kg(-1). min(-1) were 1.70 +/- 0.76 and 1.75 +/- 0.83, respectively, with no significant difference as compared with the mean WSCI at rest (P > 0.05). The pathologic examination showed viable myocardium at the ischemic regions.

CONCLUSIONLow-dose dobutamine (5 micro g.kg(-1).min(-1)) recovers hypokinetic or akinetic myocardial regions, and dobutamine stress MRI can be used to detect myocardial viability.

Animals ; Dobutamine ; Magnetic Resonance Imaging, Cine ; methods ; Male ; Swine ; Swine, Miniature ; Ventricular Function, Left

BACKGROUNDAutologous transplantation of the submandibular gland (SMG) into the temporal fossa with microvascular anastomosis has been successfully applied in severe xerophthalmia patients as a permanent tear substitute. However, severe xerophthalmia can be accompanied by salivary gland dysfunction, making such autotransplantation unsuitable. Therefore, SMG allotransplantation might be a solution. The aim of this study was to assess the technical feasibility of submandibular gland allotransplantation.

METHODSTwelve miniature swine were randomized to serve as donors or recipients. One SMG was transplanted between a donor and a recipient. The donor SMG was revascularized by microvascular anastomosis of its vascular pedicle to the recipient lingual artery and external jugular vein. The secretory duct was implanted into the vestibule of the mouth through a subcutaneous tunnel. No immunosuppressive agent was administered. The results were assessed by visual inspection of the secretion, and histopathological examination of the transplanted SMG.

RESULTSTechnically, all surgical procedures were successful. Clear secretion flowed out of the duct as soon as blood supply of the transplanted submandibular gland was reestablished. The secretion of the gland lasted for 5 days. As expected, an acute rejection reaction occurred after surgery because no immunosuppressive agents were used. Secretion from the transplanted SMG ceased within 5 days.

CONCLUSIONSA model of SMG allotransplantation can be established in miniature swine. The technique of submandibular gland allotransplantation is feasible.

Animals ; Microscopy, Electron ; Models, Animal ; Submandibular Gland ; pathology ; transplantation ; ultrastructure ; Swine ; Swine, Miniature ; Transplantation, Homologous