Bama Miniature Pigs Research Articles

Structural, functional and histological features of a novel ischemic heart failure model.

There is still no satisfactory large-animal model of ischemic heart failure (IHF) with ideal survival rate and model time. The aim of this study is to explore a novel chronic IHF model in swine. 23 healthy Ba-Ma miniature pigs were included. Pigs in the experimental group underwent multiple strategic ligations on side branches of the left anterior descending (LAD) and circumflex coronary arteries. One week later, sequential intervention occlusion of the distal end of the LAD trunk was performed. In the experimental groups, LV end-diastolic (LVEDV) and end-systolic volume (LVESV) gradually increased starting at 4 weeks postoperation. At 12 WPO, LVEDV increased from 45.0 ± 2.9 ml at baseline to 110.0 ± 9.8 ml and LVESV increased from 17.0 ± 1.4 ml at baseline to 42.0 ± 3.6 ml. Meanwhile, left ventricular ejection fraction significantly decreased from 73.8 ± 4.2 % at baseline to 31.0 ± 2.5%. According to histomorphometric assessment, viable cells were observed in infarction lesions, indicating the model has replicated the structural and functional features of chronic IHF.

Effect of Hemiepiphysiodesis on the Growth Plate: The Histopathological Changes and Mechanism Exploration of Recurrence in Mini Pig Model.

Purpose Hemiepiphysiodesis has been widely used to correct angular deformity of long bone in immature patients. However, there is a limited knowledge about the biomechanical effect of this technique on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal. We aimed to evaluate the biomechanical effect of hemiepiphysiodesis on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal in Bama miniature pigs, and to explore the role of asymmetric stress during this procedure. Methods Eight 3-month-old male Bama miniature pigs sustained surgeries on the bilateral medial hind leg proximal tibia as the intervention group (n=16), and four pigs sustained bilateral sham surgeries as the control (n=8). In the 18th week after surgeries, hardware was removed in the unilateral leg of each animal in the intervention group. In the 24th week of the study, all animals were euthanized. A total of 24 samples were obtained and stained with H&E, TUNEL, and immunohistochemistry. Sixteen samples in the intervention group were divided into two subgroups. The tibias without an implant were included in the implant removal group (IR group), while the tibias with an implant were included in the implant persist group (IP group). The proximal tibia specimens were divided into 3 equidistant parts from medial to lateral, named as area A, area B, and area C, respectively. The change of thickness of growth plates, chondral apoptosis index, and the expression of Caspase-3, Caspase-9, CHOP, and P65 were compared. Results H&E staining showed the thickness of growth plate to be varied in different areas. In the IP group, the thickness of growth plate in areas A and B was statistically significantly thinner than that in area C (p<0.05). In the IR group, the thickness of growth plate in areas A and B was statistically significantly thicker than that in area C (p<0.05). TUNEL staining showed that the apoptosis rate increased significantly after hemiepiphysiodesis and declined after implant removal (p<0.05). Immunohistochemical staining suggested that the expression of Caspase-3, Caspase-9, P65, and CHOP protein was upregulated in the experimental group and downregulated after implant removal. Conclusion The thickness parameter of the growth plate changes with asymmetric pressure. When the pressure is relieved, the recurrence of malformation is related to the thickening of the growth plate.

Hydrogen-rich saline protects against hepatic injury induced by ischemia-reperfusion and laparoscopic hepatectomy in swine

Hydrogen-rich saline (HRS) has antioxidative, anti-inflammatory and anti-apoptotic properties. We investigated the effects of hydrogen on hepatic ischemia-reperfusion (I/R) and laparoscopic hepatectomy in swine. Twenty-one healthy Bama miniature pigs were randomly divided into the sham group, ischemia-reperfusion injury (IRI) group, HRS-5 (5 mL/kg) group, and HRS-10 (10 mL/kg) group. HRS was injected through the portal vein 10 min before reperfusion and at postoperative day 1, 2 and 3. The roles of HRS on oxidative stress, inflammatory response and liver regeneration were studied. Compared with the IRI group, HRS treatment attenuated oxidative stress by increasing catalase activity and reducing myeloperoxidase. White blood cells in the HRS-10 group were reduced compared with the IRI group (P < 0.01). In the HRS-10 group, interleukin-1 beta, interleukin-6 and tumor necrosis factor alpha, C-reactive protein and cortisol were downregulated, whereas interleukin-10 was upregulated. In addition, HRS attenuated endothelial cell injury and promoted the secretion of angiogenic cytokines, including vascular endothelial growth factor, angiopoietin-1 and angiopoietin-2. HRS elevated the levels of hepatocyte growth factor, Cyclin D1, proliferating cell nuclear antigen, Ki-67 and reduced the secretion of transforming growth factor-beta. HRS treatment may exert a protective effect against I/R and hepatectomy-induced hepatic damage by reducing oxidative stress, suppressing the inflammatory response and promoting liver regeneration.

Adipose-derived stem cells alleviate liver apoptosis induced by ischemia-reperfusion and laparoscopic hepatectomy in swine

Hepatic ischemia-reperfusion (I/R) injury is inevitable during hepatectomy and may cause both postoperative morbidity and mortality. Regenerative medicine suggested adipose-derived stem cells (ADSCs) as an attractive tool for the treatment of liver diseases. In this study, we investigated the effect of ADSCs in an I/R model combined with laparoscopic hepatectomy in swine. Eighteen Bama miniature pigs were randomly divided into Sham, IRI, and ADSCs groups. ADSCs (1 × 106/kg) were injected through liver parenchyma immediately after hemihepatectomy. The apoptosis-related role of ADSCs was studied. The results showed that ADSCs transplantation reduced both pathological and ultrastructural changes and decreased the number of apoptotic-positive cells. In the ADSCs group, Fas, Fas ligand (FasL) protein, and mRNA were downregulated and the enzyme activities of Caspase3, Caspase8, and Caspase9 were significantly decreased. In addition, ADSC therapy significantly increased the ratio of Bcl-2/Bax protein and mRNA compared to the IRI group. In conclusion, ADSCs attenuated both I/R and hepatectomy-induced liver apoptosis in a porcine model, and offers a potential therapeutic option for hepatic I/R and hepatectomy.

Intracranial pressure responsiveness to positive end-expiratory pressure in different respiratory mechanics: a preliminary experimental study in pigs

BackgroundRespiratory mechanics affects the effect of positive end-expiratory pressure (PEEP) on intracranial pressure (ICP). Respiratory mechanics of the lung and the chest wall was not differentiated in previous studies. In the present study, we investigated the influence of the following possible determinants of ICP responsiveness to PEEP: chest wall elastance (ECW), lung elastance (EL), and baseline ICP.MethodsEight healthy Bama miniature pigs were studied. The increase of EL was induced by instillation of hydrochloride, and the increase of ECW was induced by strapping the animals’ chest wall and abdomen. A balloon-tipped catheter was placed intracranially for inducing intracranial hypertension. Six experimental conditions were investigated in sequence: 1) Normal; 2) Stiff Chest Wall; 3) Lung Injury; 4) Lung Injury + Stiff Chest Wall; 5) Lung Injury + Stiff Chest Wall + Intracranial Hypertension and 6) Lung Injury + Intracranial Hypertension. PEEP was gradually increased in a 5 cm H2O interval from 5 to 25 cm H2O in each condition. Blood pressure, central venous pressure, ICP, airway pressure and esophageal pressure were measured.ResultsHydrochloride instillation significantly increased EL in conditions with lung injury. ECW significantly increased in the conditions with chest wall and abdomen strapping (all p < 0.05). ICP significantly increased with increments of PEEP in all non-intracranial hypertension conditions (p < 0.001). The greatest cumulative increase in ICP was observed in the Stiff Chest Wall condition (6 [5.3, 6.8] mm Hg), while the lowest cumulative increase in ICP was observed in the Lung Injury condition (2 [1.3, 3.8] mm Hg). ICP significantly decreased when PEEP was increased in the intracranial hypertension conditions (p < 0.001). There was no significant difference in cumulative ICP change between the two intracranial hypertension conditions (p = 0.924).ConclusionsDifferent respiratory mechanics models can be established via hydrochloride induced lung injury and chest wall and abdominal strapping. The effect of PEEP on ICP is determined by respiratory mechanics in pigs with normal ICP. However, the responsiveness of ICP to PEEP is independent of respiratory mechanics when there is intracranial hypertension.

Adipose-derived stem cells reduce liver oxidative stress and autophagy induced by ischemia-reperfusion and hepatectomy injury in swine

AimsHepatic ischemia-reperfusion (I/R) injury is an unavoidable complication of liver surgery, often resulting in postoperative complications and liver dysfunction. Adipose-derived stem cells (ADSCs) have been recognized as a potential tool to be exploited in the field of regenerative medicine for the treatment of a variety of diseases. In the present study, the efficacy of ADSCs in a porcine I/R model of laparoscopic hepatectomy was evaluated. Main methodsTwelve Bama miniature pigs were randomly divided into IRI and ADSCs group. ADSCs were injected through the liver parenchyma following a partial laparoscopic hepatectomy. The roles of ADSCs on oxidative stress and autophagy were analyzed. Key findingsIt was observed that serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T-BIL) and lactate dehydrogenase (LDH) was significantly decreased in response to the ADSC treatment. The data were suggestive of the mechanism of action through which ADSCs exert their attenuating effects on oxidative stress by increasing the activity of superoxide dismutase (SOD), and by suppressing the generation of both myeloperoxidase (MPO) and malondialdehyde (MDA). Moreover, the expression of the critical markers of autophagy including Beclin1, ATG5, ATG12 and LC3II all decreased, whereas expression of P62 increased during phagophore expansion. SignificanceIn conclusion, ADSCs attenuate hepatic I/R and hepatectomy-induced liver damage by reducing oxidative stress and inhibiting autophagy.

Effects of pretreatment with nicorandil on PDCD4/NF-κB/TNF-α pathway in coronary microembolization

Objective To investigate the role of nicorandil pretreatment on protecting myocardium after coronary microembolization (CME) and on the PDCD4/NF-κB/TNF-α signaling pathway in miniature pigs. Methods Fifteen Bama miniature pigs were randomly(random number) divided into the sham operation group (sham group), microembolization group (CME group) and CME plus nicorandil group, with 5 pigs in each group. The CME model was constructed by injecting polyethylene microspheres via microcatheter into the left anterior descending artery, and pigs in the sham group were injected with the same amount of saline. Pigs in the CME plus nicorandil group were injected intravenously with nicorandil (150 μg/kg) via ear vein 30 min before CME. Cardiac function indexes were measured using cardiac ultrasonography. The expression of PDCD4 and TNF-α mRNA in myocardium were detected by fluorescence quantitative PCR, and the protein expression of PDCD4 and TNF-α in myocardium were detected by Western blotting. NF-κB activation was evaluated by electrophoretic mobility shift assay. Results (1) Cardiac function was significantly lower and the level of serum cTnI was significantly higher in the CME group compared with the sham group. CME reduced myocardial systolic dysfunction and left ventricular dilatation. The CME plus nicorandil group showed improved CME-induced cardiac function and reduced serum cTnI level when compared with the CME Group (P < 0.05). (2) Compared with the CME group, the CME plus nicorandil group showed lower PDCD4 and TNF-α expression and NF-κB activity as well as improved cardiac function (P < 0.05). Conclusions The pretreatment of nicorandil effectively reduced the myocardial damage caused by CME, mainly through inhibiting the PDCD4/NF-κB/TNF-α pathway in cardiomyocytes. Key words: Coronary vessels; Embolism; Nicorandil; Programmed cell death 4; Nuclear facotr-κappa B; Tumor necrosis factor α; Inflammation; Myocardial damage

Apolipoprotein E deficiency accelerates atherosclerosis development in miniature pigs.

ABSTRACTMiniature pigs have advantages over rodents in modeling atherosclerosis because their cardiovascular system and physiology are similar to that of humans. Apolipoprotein E (ApoE) deficiency has long been implicated in cardiovascular disease in humans. To establish an improved large animal model of familial hypercholesterolemia and atherosclerosis, the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 system (CRISPR/Cas9) was used to disrupt the ApoE gene in Bama miniature pigs. Biallelic-modified ApoE pigs with in-frame mutations (ApoEm/m) and frameshift mutations (ApoE−/−) were simultaneously produced. ApoE−/− pigs exhibited moderately increased plasma cholesterol levels when fed with a regular chow diet, but displayed severe hypercholesterolemia and spontaneously developed human-like atherosclerotic lesions in the aorta and coronary arteries after feeding on a high-fat and high-cholesterol (HFHC) diet for 6 months. Thus, these ApoE−/− pigs could be valuable large animal models for providing further insight into translational studies of atherosclerosis.

Quantification of in vivo gastric fluid volume in Bama miniature pigs in fasted state.

Although the study of bioequivalence waivers in humans is already well-established, their application and translation into animals, which are complicated by differences in physiology, have only recently become subjects of interest. The main purpose of this paper is to quantify the liquid volume affecting drug dissolution in pig stomachs. We used magnetic resonance imaging (MRI) to scan 18 Bama miniature pigs weighing 15, 30 or 50kg. Amira 6.0.1 software was used for 3D image processing. We found that the gastric fluid volume had a linear relationship with the weight of pig (R2 =0.9935) over this weight range. The pig weight, therefore, could be used as a surrogate for the fasted gastric fluid volume. After combining data of gastric fluid secretion and drinking water volumes, our results could be used as a reference for the evaluation of oral drug absorption in pigs.

Effect of hydrogen-rich saline on apoptosis induced by hepatic ischemia reperfusion upon laparoscopic hepatectomy in miniature pigs

Hepatic ischemia reperfusion injury (HIRI) occurs commonly in liver surgery and liver transplantation. Hydrogen, a safe and effective antioxidant, exerts a protective effect against liver injury. In this study, we investigated the role of hydrogen-rich saline (HRS) in apoptosis in a miniature pig model of laparoscopic HIRI upon hepatectomy. Bama miniature pigs were randomly assigned to sham, I/R and HRS groups. The pigs received 10 mL/kg HRS by portal venous injection 10 min before reperfusion and at 1 d, 2 d, and 3 d after surgery. The results showed that HRS treatment significantly decreased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) activity and TUNEL-positive cells. Upon HRS treatment, the expression of P53 and Bax mRNA and protein by RT-qPCR and Western blot was markedly decreased, whereas the expression of bcl-2 mRNA and protein was significantly increased. Moreover, Caspase-3 and Caspase-9 activities were significantly decreased upon treatment with HRS. In conclusion, the results indicate that HRS could alleviate liver injury and improve liver function via inhibiting apoptosis after laparoscopic HIRI and hepatectomy injury in miniature pigs.

Tmax is a sensitive indicator of myocardial ischaemia under adenosine stress as determined by static PET imaging: a study in a porcine model

To evaluate Tmax, defined as the time of residual function R(t) reaching its maximum, as an indicator of myocardial ischaemia and compare its efficacy with other computed tomography perfusion (CTP) parameters. Eight Bama miniature pigs with 50-90% left anterior descending artery stenosis underwent adenosine stress myocardial CTP and 13NNH3 position-emission tomography (PET) perfusion imaging. Tmax, myocardial blood flow (MBF), myocardial blood volume (MBV), mean transit time (MTT), and time to peak (TTP) were calculated from CTP images. PET images were evaluated as ischaemia or non-ischaemia. Using PET as a reference standard, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Multiple comparisons of the receiver operating characteristic (ROC) curves between Tmax and other parameters were performed. The diagnostic performance of the combination of each two parameters was calculated and compared with Tmax. RESULTS: Tmax was significantly higher in ischaemic segments compared with non-ischaemic segments. Multiple comparisons of the ROCs indicated that Tmax was better than MBF or TTP but not statistically different from MBV. Tmax was superior to the combination of (MBF+MBV) but not to (MBF+TTP) or (MBV+TTP). Tmax in dynamic stress CTP provides good diagnostic accuracy for detecting myocardial ischaemia, especially in sensitivity and NPV, compared with PET method. Tmax has better performance than MBF or TTP or combination of (MBF+MBV) in diagnosing myocardial ischaemia.

Therapeutic potential of Bama miniature pig adipose stem cells induced hepatocytes in a mouse model with acute liver failure.

The role of mesenchymal stem cells (MSCs) in cellular therapy is well recognized in this work. MSCs have advantages of high proliferation, clone formation, multi-lineage differentiation and immunosuppression. Furthermore, adipose-resident MSCs (ADSCs) are extensively employed due to its advantages of abundant source, low cost and simple operation. Many researchers have emphasized the role of adipose-resident MSCs in the development of therapies for liver injury, but few attentions were paid on the use of induced functional hepatocytes. Therefore, in this work the role of adipose-resident MSCs induced functional hepatocytes was mainly investigated. The function of induced hepatocytes by ELISA and the induction rate was confirmed by flow cytometryand evaluated by experimental observations. The induced hepatocytes were firstly transplanted into CCl4-caused liver damage ICR mice by tail vein. After transplantation, both liver fibrosis and function could be improved by hepatocytes, which were examined through histology, immunofluorescence staining, serum profile and biochemical parameters levels. The production of cytokines was then compared with normal mice and injury mice to explore the therapeutic mechanisms of hepatocytes. Finally, the secretions of TGF-β1, IL-6 and IL-10 in hepatocytes transplanted mice were determined and found to be higher than that of the normal and injury mice. The hepatocytes derived from ADSCs were proven to have a great significance in the therapeutic efficacy and clinical settings of liver disease animal models.

A study on the classification of intestinal contents based on miniature reflection ultrasound

The present artificial anal sphincter fails to distinguish the different states of intestinal contents. In this study, we tried to distinguish the intestinal content by using a reflection type ultrasonic system, so as to lay the foundation for the development of artificial anal sphincter with sensing function. We measured the numbers of reflected waves when there were solid, liquid, gaseous or no contents in the recta of 30 Bama Miniature pigs. The results showed significant difference among the numbers of reflected waves of the 4 conditions ( F = 1 088, P < 0.05). Our research suggested the reflection-type ultrasonic system could be utilized to distinguish various contents inside the intestinal lumen, thus it might offer a new effective method for the development of artificial anal sphincter with sensing function.

A DNA nanorobot functions as a cancer therapeutic in response to a molecular trigger in vivo.

Nanoscale robots have potential as intelligent drug delivery systems that respond to molecular triggers. Using DNA origami we constructed an autonomous DNA robot programmed to transport payloads and present them specifically in tumors. Our nanorobot is functionalized on the outside with a DNA aptamer that binds nucleolin, a protein specifically expressed on tumor-associated endothelial cells, and the blood coagulation protease thrombin within its inner cavity. The nucleolin-targeting aptamer serves both as a targeting domain and as a molecular trigger for the mechanical opening of the DNA nanorobot. The thrombin inside is thus exposed and activates coagulation at the tumor site. Using tumor-bearing mouse models, we demonstrate that intravenously injected DNA nanorobots deliver thrombin specifically to tumor-associated blood vessels and induce intravascular thrombosis, resulting in tumor necrosis and inhibition of tumor growth. The nanorobot proved safe and immunologically inert in mice and Bama miniature pigs. Our data show that DNA nanorobots represent a promising strategy for precise drug delivery in cancer therapy.

Cholecystokinin octapeptide inhibits the inflammatory response and improves neurological outcome in a porcine model of cardiopulmonary resuscitation.

Previous studies have demonstrated that cholecystokinin octapeptide (CCK8) induces hypothermia and inhibits the systemic inflammatory response in septic shock in rat and murine models. The present study aimed to ascertain whether CCK8 induced hypothermia and improved the neurological outcomes in a porcine model of cardiopulmonary resuscitation (CPR). Ventricular fibrillation was induced and left untreated for 10 min in 12 male Bama miniature pigs. Defibrillation was attempted after 5 min of CPR. At 5 min following resuscitation, the pigs were randomized and equally assigned into the CCK8 or the control group. CCK8 was continuously infused for 1 h at a dose of 44.4 µg/kg/h and a rate of 20 ml/h in the CCK8 group. Body temperature, hemodynamic measurements and post-resuscitation myocardial function were monitored in the first 4 h following CPR. Neuron specific enzyme (NSE), S100B protein, tumor necrosis factor (TNF)-α and interleukin (IL)-6 were measured at baseline and 4, 12 and 24 h following resuscitation. The neurological deficient score (NDS) was recorded and cerebral samples were collected for terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling assay and integrated optical density (IOD) analysis at 24 h following CPR. The results revealed that hypothermia was not induced by CCK8; however, post-resuscitation NSE, S100B, IL-6 and TNF-α were significantly decreased, and NDS and IOD were significantly improved in the CCK8 group compared with the control group (P<0.05). The present study revealed that in a porcine model of CPR, CCK8 does not induce hypothermia, but inhibits the inflammatory response and significantly improves neurological outcomes.

Hydrogen-rich saline protects against small-scale liver ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress

AimOur research investigated the role of Hydrogen-rich saline (HRS) on the Endoplasmic reticulum stress (ERS) pathway and the effect of HRS on tissue injury in small Bama pig model of hepatic ischemia-reperfusion combined with partial hepatectomy. Main methodsEighteen healthy Bama miniature pigs were randomly divided equally into three groups: Sham, IRI, and HRS. Laparoscopic technique was employed to establish the model of hepatic ischemia-reperfusion combined with partial hepatectomy. HRS (10mL/kg) was injected into the portal vein 10min before perfusion. Histological examinations of the liver tissues were performed after HE staining. Additionally, transmission electron microscopy was performed to detect liver cell microstructure. Real-time PCR, Western blotting, and immunohistochemical staining were performed to analyze various ERS molecules including GRP78, p-eIF2α, XBP-1s, Full-length ATF6α, p-JNK, ATF4, and CHOP. Key findingsWe observed that HRS visibly improved ischemia-reperfusion injury (IRI) by reducing various parameters of ERS stress as evidenced by down-regulation of the mRNA as well as protein levels of GRP78, p-eIF2α, XBP-1s, p-JNK, and CHOP, and reducing the cleavage of Full-length ATF6α. SignificanceOur study demonstrates that HRS protects the liver from IRI by inhibiting ERS.

Thyroid hormone regulates hematopoiesis via the TR-KLF9 axis

AbstractCongenital hypothyroidism (CH) is one of the most prevalent endocrine diseases, for which the underlying mechanisms remain unknown; it is often accompanied by anemia and immunodeficiency in patients. Here, we created a severe CH model together with anemia and T lymphopenia to mimic the clinical features of hypothyroid patients by ethylnitrosourea (ENU) mutagenesis in Bama miniature pigs. A novel recessive c.1226A>G transition of the dual oxidase 2 (DUOX2) gene was identified as the causative mutation. This mutation hindered the production of hydrogen peroxide (H2O2) and thus contributed to thyroid hormone (TH) synthesis failure. Transcriptome sequencing analysis of the thymuses showed that Krüppel-like factor 9 (KLF9) was predominantly downregulated in hypothyroid mutants. KLF9 was verified to be directly regulated by TH in a TH receptor (TR)-dependent manner both in vivo and in vitro. Furthermore, knockdown of klf9 in zebrafish embryos impaired hematopoietic development including erythroid maturation and T lymphopoiesis. Our findings suggest that the TR-KLF9 axis is responsible for the hematopoietic dysfunction and might be exploited for the development of novel therapeutic interventions for thyroid diseases.

Partial (two-thirds) nephrectomy in pigs: A comparison of three surgical approaches

Partial (2/3) nephrectomy can be performed via the laparoscopic, retroperitoneal, and transperitoneal approach. Outcomes of the three approaches were compared in this study. 2/3 nephrectomy were performed in 21 healthy Bama miniature pigs (mean bodyweight 20.59±2.78kg). Pigs were divided into three groups: those that underwent 2/3 nephrectomy via laparoscopy (LN group, n=7), the retroperitoneal approach (RN group, n=7), or the transperitoneal approach (TN group, n=7). We monitored pre- and postoperative physiologic parameters, blood cell count, and stress and renal function biomarkers. Differences among groups were analyzed. 2/3 nephrectomy was successfully performed in all pigs without any complications. Mean surgical time in the LN group (60.71±7.34min) and the TN group (58.57±4.72min) was significantly longer than that in the RN group (41.14±5.33min). Warm ischemia in the LN group (38±7.57min) was significantly longer than that in the TN group (28.86±4.53min), which was significantly longer than that in the RN group (17.86±2.34min). The postoperative serum concentration of C-reactive protein in the TN group was significantly higher than that in the LN group (p<0.05). So retroperitoneal approach was best choice in case of bilateral renal lesion resulted in shortest ischemia time, and laparoscopic partial nephrectomy should be the primary choice in majority situations resulted in less body stress, smaller surgical incisions and less blood loss.

POSS-modified PEG adhesives for wound closure

PEG-related adhesives are limited in clinical use because they are easy to swell and cannot support the cell growth. In this study, we produced a series of POSS-modified PEG adhesives with high adhesive strength. Introduction of inorganic hydrophobic POSS units decreased the swelling of the adhesives and enhanced cell adhesion and growth. The in vitro cytotoxicity and in vivo inflammatory response experiments clearly demonstrated that the adhesives were nontoxic and possessed excellent biocompatibility. Compared with the sutured wounds, the adhesive-treated wounds showed an accelerated healing process in wounded skin model of the Bama miniature pig, demonstrating that the POSS-modified PEG adhesive is a promising candidate for wound closure.

Development and Assessment of Normothermic Machine Perfusion Preservation for Extracorporeal Splitting of Pig Liver.

BACKGROUND Studies have shown that normothermic machine perfusion (NMP) exerts a significant protective role for donations after cardiac death (DCD) livers and verified the effects of NMP in preservation, repair, and preoperative assessment of human donor livers. The objective of this study was to verify the effectiveness and stability of NMP system by splitting pig livers in perfusion preservation. MATERIAL AND METHODS Four healthy Ba-Ma miniature pigs were used. The livers were harvested, and then connected to the NMP system to split the livers. The indexes during the splitting were recorded, the serological indices were measured, and routine pathological examination of liver tissue were observed. RESULTS With splitting, the portal vein pressure and the hepatic artery pressure were not significantly changed. The flow in the portal vein and hepatic artery reduced respectively from 455±107.55 mmHg, 180.75±59.46 mmHg before splitting to 392.5±125.27 mmHg and 126.25±6.99 mmHg after splitting. The liver preservation temperature was controlled to 38.83±0.24 to 38.93±0.43°C during splitting. At the beginning of perfusion preservation, the alanine aminotransferase(ALT), lactate dehydrogenase(LDH), and alkaline phosphatase (ALP) were lower than the baseline level; ALT and LDH gradually increased with splitting, whereas ALP was maintained in a lower level in the splitting. At the beginning of perfusion preservation, aspartate aminotransferase(AST) was comparable with the baseline value, and it was gradually increased with splitting. The cell structure in the liver before NMP preservation and after splitting did not show significant changes. CONCLUSIONS The NMP device developed in this study can be used for donor liver preservation and splitting, without causing significant liver damage.