饲粮营养水平对猪背最长肌IMF含量及部分相关因子的影响

试验选用84头体重接近10 kg的杜洛克×长白×大约克三元杂交(DLY)阉公猪,随机分成2组,每组6个重复,每个重复7头猪。研究在NRC(1998)标(准对照组)和荣昌猪饲养标(准试验组)2种饲粮条件下,营养水平对DLY生长肥育期血液胰岛素、背最长肌IMFc、AMPI、R含量及ACC mRNA表达量的影响。结果表明:①荣昌猪饲养标准下,各阶段试验组背最长肌肌内脂肪含量均高于对照组,50kg时达到了显著水平(P<0.05)。②试验组背最长肌cAMP水平50kg时低于对照组(P<0.01);IR含量80kg时显著低于对照组(P<0.05)。     

In vitro evaluation of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System

OBJECTIVE: To evaluate the mechanical properties of the 18 and 36 kg Securos Cranial Cruciate Ligament Repair System. STUDY DESIGN: In vitro mechanical evaluation. SAMPLE POPULATION: Loop constructs of 18, 27, and 36 kilogram test (kgt) nylon leader line (NLL) secured with Securos crimp-clamps (SCC, n=40 per NLL test weight) or by a clamped square knot (CSK; n=40/NLL test weight). METHODS: The 36 kg SCC were used for the 27 and 36 kgt NLL, and 18 kg SCC were used for the 18 kgt NLL. Loop constructs were mounted on a material testing machine, and distracted at 500 mm/min for static tests, and for cyclic tests at 500 mm/min to a distraction limit of 6 mm (18 kgt) or 7.5 mm (27 and 36 kgt) for 49 cycles, until failure. Constructs were tested at 20 degrees C except for 1 group of 27 kgt CSK loops tested at 40 degrees C. Load at failure, elongation, and stiffness was recorded and compared between groups under static or cyclic testing conditions. RESULTS: All 27 and 36 kgt loops failed by disruption of NLL contained within the knot or crimp-clamp, whereas 18 kgt SCC loops failed by the NLL pulling through the crimp-clamp. The 18 kg SCC loops had considerable variability in ultimate load and elongation (coefficient of variation 29.6% and 18.3%, respectively). There was no significant difference in elongation between 27.3 kgt CSK loops tested at 20 degrees C and 40 degrees C. Generally, in both static and cyclic testing, SCC constructs formed with 27.3 or 36.4 kgt NLL performed as well or better than CSK constructs, resulting in loops that were strong, underwent minimal elongation, and had high stiffness. CONCLUSION: The results support use of the 36 kg Securos system but not the 18 kg Securos system (with the clamp and crimping device used). The significantly lower load required for failure, slippage through the clamp, and substantial variability suggested that the crimp tube diameter or the crimping device tested may be inappropriate for use with 18 kgt NLL. CLINICAL RELEVANCE: Surgeons should be aware that crimp-clamp design is important in controlling suture slippage or breakage within the clamp, and that novel systems should undergo mechanical testing with the size suture material they are intended to secure before clinical use.     

日粮核苷酸对机体炎症抗炎症平衡体系的影响

为探讨日粮核苷酸对小鼠炎症／抗炎症平衡体系的作用，用CpG DNA和脂多糖（LPS）刺激小鼠构建炎症反应模型，观察分别饲喂无核苷酸（NF）日粮和核苷酸（NT）日粮小鼠的炎性细胞因子IL-1、IFN-λ，、抗炎性细胞因子IL-10水平和小肠髓过氧化物酶（MPO）活性变化。结果显示，在刺激后第4h时，NT组小鼠的IL-1（P〈0．05）、IFN-λ，（P〈0．01）和小肠MPO（P〈0．01）明显低于NF组，IL-10（P〉0．05）高于NF组；刺激后第18h时，NT与NF组的IL-1（P〈0．01）、IFN-λ，（P〈0．01）、IL-10（P〉0．05）和MPO（P〈0．01）均较刺激后第4h有所降低，NT组的IL-1（P〉0．05）、IFN-λ，（P〈0．05）和小肠MPO（P〈0．05）仍低于NF组，IL-10（P〉0．05）仍高于NF组。表明，日粮核苷酸对CpG DNA或LPS所诱导的炎症反应有明显的抑制作用，有助于维持机体炎症／抗炎症平衡，保护机体免受炎症损伤。     

日粮核苷酸对动物免疫功能的影响研究进展

核苷酸（嘌呤和嘧啶）是组成DNA和RNA单体，在体内具有重要的生理生化作用。人和动物能从头合成核苷酸。在机体迅速生长、或动物受到免疫挑战时，一些器官、组织内源合成的不能满足机体的需要。补充日粮核苷酸对于动物免疫细胞、器官的发育及维持免疫系统正常功能有积极作用。     

磷酸二酯酶基因在小型猪骨骼肌组织的表达

提取中国实验用小型猪骨骼肌组织总RNA，应用反转录聚合酶链反应测定磷酸二酯酶(PDE)同工酶在骨骼肌组织中的表达分布。结果可见PDE1A、1C、2A、3A、3B、4A、4B、4C、4D、5A、7A、7B、8A、8B、9A和11A共16种PDE同工酶mRNA在中国实验用小型猪骨骼肌组织中表达，其中PDE1A、1C、2A、3A、4B、4C、8A和8B共8种在人和其他动物骨骼肌组织中的表达分布未见报道，PDE1B和10A3种同工酶未见表达。16种PDE同工酶mRNA在骨骼肌组织中的表达，从电泳条带上可以看到各种PDE表达量存在着差异，但需要进一步做定量分析加以评定。     

Changes of AC activity and content of cAMP in hypothalamus of rats with fever and hypothermia

AIM:To observe the changes of AC activity and content of cAMP at different time point in hypothalamus of rats with fever and hypothermia. METHODS:Radioisotope method was used to measure the enzymatic activity of AC and the content of cAMP. RESULTS:(1)The fresh yeast caused fever after making model 4 h(P＜0.01). AC activity reached a peak value 3 h after making model (P＜0.05), subsequently AC activity rapidly decreased and increased again over normal level (P＜0.01);The change of cAMP content was positively related to the body temperature. (2) Aminopyrine induced rat hypothermia state after making model 15 min (P＜0.05). AC activity rapidly weakened and cAMP content rapidly descended to the lowest value at making model 45 min, subsequently AC activity and cAMP content in hypothalamus gradually increased again to normal range. CONCLUSION:(1)In fever model, it might be an important cause of febrile response that AC induced increase in intracellular cAMP content; (2) In hypothermia model, the significant decrease of AC activity and cAMP content indicate that cAMP might play a role in keeping hypothermia.     

北京市发展循环农业的问题及对策建议

循环农业是发展循环经济,促进可持续发展的重要内容。笔者以探讨北京市发展循环农业的现实意义为出发点,结合北京市资源紧缺、农业面源污染严重、畜牧业生产排污量大、产业关联性不强等农业生产与农村环境中存在的现实问题,遵照循环经济理论及经验,提出北京市发展循环农业的相关建议。     

Signals controlling renin release in aglomerular toadfish

The toadfish,Opsanus tau, lacks renal glomeruli and macula densa, but has high renal renin activity and abundant granulated cells in renal arteries and arterioles. Reduction of blood pressure (BP) or blood volume by hemorrhage or vasodilatory drugs causes renin release, indicating that an intrarenal or extrarenal pressure- or volume-sensitive mechanism exists for controlling renin release in the toadfish. Thus, we examined whether 1) β-adrenergic receptor-mediated activation of renin release, and 2) calcium influx which may underlie the baroreceptor mechanism are involved in the cellular control of renin release. Acute injection of isoproterenol (1 μg/kg, n = 6) decreased BP and increased plasma renin activity (PRA) 4–5 fold in unanesthetized toadfish. Propranolol abolished both effects, but did not decrease basal PRA levels.In vitro superfusion of renal slices with bicarbonate Ringer's solution showed a steady secretion of renin, and addition of 50 mM K⁺ (K⁺ methylsulfate replacing NaCl, n = 10) to the superfusate markedly suppressed renin secretion. Nifedipine (10⁻⁵ M, n = 8) completely restored the high K⁺-induced inhibition of renin secretion from renal slices, whereas isoproterenol (10⁻⁴ M, n = 6) neither increased basal renin secretion nor restored K⁺-induced renin suppression. These results suggest that calcium influx may mediate inhibitory messages for renin secretion, while the β-adrenoceptor-mediated activation of granulated cells appears absent in toadfish.     

不同葡萄废果组成对厌氧发酵转化活性物质的影响

为分析不同葡萄废果组成对厌氧发酵过程和发酵产物中活性物质组分的影响,以葡萄废果为原材料,添加酵母菌进行厌氧发酵,设置不同葡萄废果组成,考察含有葡萄皮和籽粒是否会对葡萄废果厌氧发酵产生影响。结果表明：不同底物组成对发酵过程中pH的动态变化有影响,去除葡萄皮和籽粒（T2）处理的pH高于含有葡萄废果全部成分（T1）的处理;而底物组成的差异对EC值的动态变化没有明显影响。添加酵母菌进行厌氧发酵能显著提高产物中游离氨基酸和总有效氮的含量（P<0.05）,与发酵前相比分别提高了226.05%~276.66%和31.13%~40.75%。去除葡萄皮和籽粒后有利于发酵产物中游离氨基酸含量的提高,T2处理在9类氨基酸的含量上均具有显著优势,但F^-、总酚和总酸的含量出现了显著降低。研究表明,外源添加酵母菌进行厌氧发酵是一种潜在的葡萄废果资源化循环利用方式,不同底物组成对发酵产物的组分有一定影响,发酵产物中含有丰富的营养元素和活性物质,具有较高的再利用价值。