Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment. SETTING: Zhongshan Hospital Affiliated to Dalian University. MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI. RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.     

Clostridium difficile PCR ribotype 046 is common among neonatal pigs and humans in Sweden

Clostridium difficile PCR ribotype 046 was found in 67% of neonatal piglets (45/67) sampled from three separate pig-breeding farms in Sweden. Sows from the same farms were tested and 50% were colonized in faeces and 30% were colonized on skin. An environmental source was suggested because identical PCR ribotypes were isolated from faeces as well as externally. Human C. difficile infection outbreaks in southern Sweden by the identical PCR ribotype 046 indicate its zoonotic potential.     

Polychlorinated dibenzo‐p‐dioxins and dibenzofurans levels in piglet liver with various diseases

This study deals with the levels of toxic polychlorinated dibenzo‐p‐dioxin and furan congeners (PCDD/Fs) in the livers of piglets affected by infectious diseases using isotope dilution high‐resolution gas chromatography/high‐resolution mass spectrometry (HRGC/HRMS). Seventeen toxic congeners in the liver samples infected with bacterial and viral diseases were compared. For porcine reproductive and respiratory syndrome virus (PRRSV) samples, the North American‐ and European‐type PRRS diseases were observed. This study shows that there are significantly different levels of PCDD/Fs, present, which vary according to the types of diseases as evidenced by our analysis of the piglet liver samples.     

Low immunoreactive glycated soybean antigen proteins production: system-wide analysis of their immunogenicity in vitro and in vivo

The current study aimed to remit the immunoreactivity of glycinin and β-conglycinin through the methods of glycation. The immunoreactivity of the glycated soybean antigen proteins after hydrolyzed was analyzed in vitro. Then in the in vivo trial, 24 crossbred castrated piglets were allocated to four dietary treatments in a complete block design, each treatment with six replicates. From day 29–43, the control groups were fed diets with 4% unglycated glycinin or β-conglycinin, while the treatment groups received diets containing 4% glycated glycinin or β-conglycinin. Generally, the immunoreactivity removal rate increased in all products as time went on both in vitro and in vivo. The immunoreactivity residual rate of unglycated soybean antigen protein was much higher than those of the glycated ones in vitro. Moreover, pepsin and trypsin affected glycated glycinin and glycated β-conglycinin in a different way.     

Detection of Sialic Acid-Utilising Bacteria in a Caecal Community Batch Culture Using RNA-Based Stable Isotope Probing

Sialic acids are monosaccharides typically found on cell surfaces and attached to soluble proteins, or as essential components of ganglioside structures that play a critical role in brain development and neural transmission. Human milk also contains sialic acid conjugated to oligosaccharides, glycolipids, and glycoproteins. These nutrients can reach the large bowel where they may be metabolised by the microbiota. However, little is known about the members of the microbiota involved in this function. To identify intestinal bacteria that utilise sialic acid within a complex intestinal community, we cultured the caecal microbiota from piglets in the presence of ¹³C-labelled sialic acid. Using RNA-based stable isotope probing, we identified bacteria that consumed ¹³C-sialic acid by fractionating total RNA in isopycnic buoyant density gradients followed by 16S rRNA gene analysis. Addition of sialic acid caused significant microbial community changes. A relative rise in Prevotella and Lactobacillus species was accompanied by a corresponding reduction in the genera Escherichia/Shigella, Ruminococcus and Eubacterium. Inspection of isotopically labelled RNA sequences suggests that the labelled sialic acid was consumed by a wide range of bacteria. However, species affiliated with the genus Prevotella were clearly identified as the most prolific users, as solely their RNA showed significantly higher relative shares among the most labelled RNA species. Given the relevance of sialic acid in nutrition, this study contributes to a better understanding of their microbial transformation in the intestinal tract with potential implications for human health.     

金属硫蛋白对仔猪抗氧化功能及SOD基因表达的影响

目的：用仔猪作模型,研究经锌元素诱导的外源性金属硫蛋白（Zn—MT）对机体抗氧化功能和超氧化物歧化酶（SOD）基因表达的影响．方法：选用杜长大杂交仔猪18头,随机分为3组（1,2和3）．分别肌肉注射经生理盐水溶解的猪肝Zn—MT0mg／kg（1组）,0．8mg／kg（2组）,1．6mg／kg（3组）,让仔猪运动产生应激．注射MT后3h和6h,分别从每组取3头仔猪屠宰取肝脏,测定肝脏中与抗氧化有关的生化指标,检测肝脏SOD基因表达水平．结果：在应激条件下,补充外源性Zn—MT一段时间后,仔猪肝脏SOD,GSH—PX活性显著升高（P〈0．05）,MDA含量显著降低（P〈0．05）,肝脏抗活性氧和抗超氧阴离子水平也有提高的趋势．在注射Zn—MT后6h,0．8mg／kg．1．6mg／kg组仔猪肝脏SOD基因表达水平比对照组显著提高（P〈0．05）．0．8ms／kg组和1．6ms／kg组6hSOD基因表达水平比3h显著增加,表明MT对SOD基因表达的诱导与时间和剂量关系密切．结论：补充外源性Zn—MT可提高应激机体的抗氧化物酶活性,从而提高机体的抗应激能力．     

Evaluation of the Safety of a Plant-Based Infant Formula Containing Almonds and Buckwheat in a Neonatal Piglet Model

A randomized neonatal piglet trial was conducted to evaluate the safety and the effects of a plant-based formula containing almonds and buckwheat as the main ingredients on growth and plasma parameters. From postnatal day (PND) 2 to 21, the piglets were fed a dairy-based milk formula (Similac Advance) or a plant-based formula (Else Nutrition) and all piglets were euthanized at day 21. No diarrhea was observed after PND 8 and all the piglets completed the trial. Body growth, kcal intake, the complete plasma count parameters and hematological parameters were within the reference range in both groups. Organ growth and development was similar between the two groups. Plasma glucose was higher in the dairy-based-fed piglets relative to the plant-based at 2 weeks of age. Liver function biomarkers levels were greater in the plasma of the plant-based compared to the dairy-based fed group. In addition, calcium levels were higher in the plant-based fed piglets at 1 week of age. Thus, the plant-based formula tested in this study was well tolerated by the piglets and supported similar growth compared to dairy-based milk formula. Therefore, the results support the safety of the tested plant-based infant formula during the neonatal period in comparison to the dairy-based formula fed group.     

Perinatal expression of heat-shock protein 27 in brain regions and nonneural tissues of the piglet

Important stressful events occur at birth or within the few hours that follow this event. To unravel a possible involvement of stress proteins, it is important to determine their levels of expression. Expression of HSP27 protein was determined by Western blotting in several nonneural tissues and in brain regions of the developing pig (fetal to adult). Maximum levels of expression were observed in heart, liver, and lung. In kidney, the expression was reduced during the first hours of life. Brain parts included whole brain, cerebellum, cortex, hippocampus, hypothalamus, and striatum. HSP27 immunogenicity was observed in all the brain regions studied. In whole brain, cerebellum, cortex, hippocampus, and hypothalamus extracts, the levels of HSP27 were decreased during the first hours of age (4 h to 2 d). In striatum, levels of expression were very low—if detectable—during the early postnatal days of life. Changes in environmental parameters, like temperature and/or hypoxia can be possibly related to differential expressions of HSPs, which can result in severe adverse developmental outcomes. The results are discussed in terms of using the newborn piglet as a model to study different forms of stress on the heat-shock protein postnatal expression.     

Nitric oxide inhalation inhibits pulmonary apoptosis but not inflammatory injury in porcine meconium aspiration

To investigate the possible protective effects of nitric oxide (NO) inhalation in newborns with meconium aspiration, 18 10-12-d-old piglets were studied for 6h after an intratracheal bolus (3 ml/kg) of a 65-mg/ml mixture of human meconium. Twelve of the piglets were treated with continuous NO inhalation at a dose of 1 ppm ( n = 6) or 10 ppm ( n = 6), started 30 min before the insult. Pulmonary haemodynamics and systemic oxygenation were followed, and lung tissue samples were studied for signs of inflammation, evidence of ultrastructural injury and apoptotic cell changes. Inhalation of 10 ppm NO, in contrast to 1 ppm NO, significantly delayed the meconium-induced pulmonary pressure rise and the increase in intrapulmonary shunt fraction, and maintained better oxygenation in the piglets. Histologically and biochemically, treatment with 1 or 10 ppm NO inhalation did not protect the lungs against meconium-induced inflammatory injury. Further, ultrastructural lung tissue analysis revealed a significant amount of alveolar exudate and oedematous alveolar epithelium and endothelium after meconium instillation, also in the lungs treated with NO inhalation. However, the increase in apoptotic epithelial cell deaths, previously shown to be stimulated by intratracheal meconium, was significantly impeded after inhalation of 10 ppm. These results thus show that early continuous NO inhalation controls the rise in pulmonary artery pressure and improves the efficiency of arterial oxygenation, and further prevents the increase in epithelial apoptosis, but does not protect against early inflammatory damage caused by meconium aspiration.