迷你猪成新宠

英国最近流行养迷你猪，这些猪有着小小的蹄子，大大的耳朵，鼻子上有很多褶皱，样子非常可爱。它们刚出生时体型大约仅有一只茶杯那么大，体重只有255．15克.

Magnetic resonance-based total liver volume and magnetic resonance-diffusion weighted imaging for staging liver fibrosis in mini-pigs

AIM:To determine whether and how magnetic resonance imaging(MRI)-based total liver volume(TLV) and diffusion weighted imaging(DWI) could predict liver fibrosis.METHODS:Sixteen experimental mature mini-pigs(6 males,10 females),weighing between 20.0 and 24.0 kg were prospectively used to model liver fibrosis induced by intraperitoneal injection of 40% CCl4 dissolved in fat emulsion twice a week for 16 wk,and by feeding 40% CCl4 mixed with maize flour twice daily for the subsequent 5 wk.All the survival animals underwent percutaneous liver biopsy and DWI using b = 300,500 and 800 s/mm2 followed by abdominal gadolinium-enhanced MRI at the 0,5th,9th,16th and 21st weekend after beginning of the modeling.TLV was obtained on enhanced MRI,and apparent diffusion coefficient(ADC) was obtained on DWI.Hepatic tissue specimens were stained with hematoxylin and Masson' s trichrome staining for staging liver fibrosis.Pathological specimens were scored using the human METAVIR classification system.Statistical analyses were performed to determine whether and how the TLV and ADC could be used to predict the stage of liver fibrosis.RESULTS:TLV increased from stage 0 to 2 and decreased from stage 3(r = 0.211;P < 0.001).There was a difference in TLV between stage 0-1 and 2-4(P = 0.03) whereas no difference between stage 0-2 and 3-4(P = 0.71).TLV could predict stage ≥ 2 [area under receiver operating characteristic curve(AUC) = 0.682].There was a decrease in ADC values with increasing stage of fibrosis for b = 300,500 and 800 s/mm2(r =-0.418,-0.535 and-0.622,respectively;all P < 0.001).Differences were found between stage 0-1 and 2-4 in ADC values for b = 300,500 and 800 s/mm2,and between stage 0-2 and 3-4 for b = 500 or 800 s/mm2(all P < 0.05).For predicting stage ≥ 2 and ≥ 3,AUC was 0.803 and 0.847 for b = 500 s/mm2,and 0.848 and 0.887 for b = 800 s/mm2,respectively.CONCLUSION:ADC for b = 500 or 800 s/mm2 could be better than TLV and ADC for b = 300 s/mm2 to pre-dict fibrosis stage ≥ 2 or ≥ 3.

Effect of Intracoronary Infusion of Bone Marrow Mononuclear Cells or Peripheral Endothelial Progenitor Cells on Myocardial Ischemia-reperfusion Injury in Mini-swine

Objective To simulate and assess the clinical effect of intracoronary infusion of bone marrow mononuclear cells or peripheral endothelial progenitor cells on myocardial reperfusion injury in mini-swine model. Methods Twenty-three mini-swine with myocardial reperfusion injury were used as designed in the study protocol. About （3.54±0.90）×10^7 bone marrow mononuclear cells （MNC group, n=9） or （1.16± 1.07）× 10^7 endothelial progenitor cells （EPC group, n=7） was infused into the affected coronary segment of the swine. The other mini-swine were infused with phosphate buffered saline as control （n=7）. Echocardio- graphy and hemodynamic studies were performed before and 4 weeks after cell infusion. Myocardium infarc- tion size was calculated. Stem cell differentiation was analyzed under a transmission electromicroscope. Results Left ventricular ejection fraction dropped by 0% in EPC group, 2% in MNC group, and 10% in the control group 4 weeks after cell infusion, respectively （P〈0.05）. The systolic parameters increased in MNC and EPC groups but decreased in the control group. However, the diastolic parameters demonstrated no significant change in the three groups （P〉0.05）. EPC decreased total infarction size more than MNC did （1.60±0.26 cm2 vs. 3.71±1.38 cm2, P〈0.05）. Undermature endothelial cells and myocytes were found under transmission electromlcroscope. Conclusions Transplantation of either MNC or EPC may be beneficial to cardiac systolic function, but might not has obvious effect on diastolic function. Intracoronary infusion of EPC might be better than MNC in controlling infarction size. Both MNC and EPC may stimulate angiogenesis, inhibit flbrogenesis, and differentiate into myocardial cells.

Changes of Color and Blood Flow of the Tongue in the Mini-swine of Immune Hepatic Injury

Objective:To investigate color and microvascular blood flow of the tongue in the mini-swine with immune hepatic injury. Methods: Six Chinese mini-swine for experimental use, 3 males and 3 females, were randomly divided into two groups, normal group and model group, 3 swine in each group. The swine in the model group was administrated by injection of 5 mg/kg ConA into the vein of auricular back, once every other day, 3 times each week, for 2 weeks in total. The animal in the control group was administrated with equal volume of saline. At 9 o’clock in the morning of the 15th day of the experiment, each swine was anesthetized with intramuscular injection of 9 ml 2.5% pentobarbital sodium and 3 ml Maleate, and then picture of the tongue was taken, microvascular blood flow on the tongue and the liver was detected with a laser Doppler blood flowmeter; Blood was taken from the precaval vein. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST),total bilirubin (Tbil) and total protein (TP) were determined; Pathological changes of the liver and tongue tissues were investigated by means of HE staining; Serum TNF-α content was detected with ELISA assay. Results: In the mini-swine with immune hepatic injury induced by ConA, the tongue color showed cyanotic color, microvascular perfusion in the liver and the tongue, and partial pressure of oxygen in the tongue tissue significantly decreased; and the microcirculatory perfusion of the tongue was significantly correlated with that of the liver and the HIS color spatial value of the tongue; Serum TNF-α content significantly increased. Conclusion: The mini-swine with immune hepatic injury induced by ConA conforms to pathological characteristics of immune hepatic injury. Formation of the cyanotic tongue is related with microcirculatory disturbance of the tongue, which can indirectly reflect hepatic microcirculatory state in the immune hepatic injury.