大约克夏生长肥育期生长规律的研究

对60头大约克夏从70～190日龄,每隔15d测定体重和背膘厚,分析其生长发育规律。结果表明:①大约克夏生长肥育期的各阶段日龄与体重间的相关系数r≥0.67(P<0.0001)。②Logistic模型和Compertz模型均可拟合大约克夏在生长肥育期的生长曲线(P<0.0001),但Logistic模型(R2=0.9967)优于Compertz模型(R2=0.9694)。③大约克夏130￣160日龄间的背膘厚度与体重保持极小的比值(约0.11),160日龄前背膘厚的分化生长率小于1(0.2653￣0.7711);大约克夏190日龄时体重为119.31kg,背膘厚为14.59mm。     

Mechanisms for protection of berberine against LPS-induced acute lung injury in mice

AIM:To investigate the mechanisms by which berberine attenuates LPS-induced acute lung injury, and provide a new strategy for the treatment of the lung injury due to LPS. METHODS:BALB/c mice were randomly assigned into three groups (control, LPS group, and berberine treatment group). Mice were administered intragastrically with distilled water (0.1 mL/10 g) or neutral sulfate berberine (50 mg/kg) once a day for 3 days, 1 h after intragastrical treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally (ip). All animals were sacrificed 12 h after LPS injection, the left lung tissue sections were prepared for histology analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D). In another experiment, bronchoalveolar lavage fluid (BALF) was collected, and then the total protein content, and the amounts of white blood cells (WBC) and polymorphonuclear neutrophils (PMN) in BALF were determined. Furthermore, the phosphorylation of cytosolic phospholipase A₂ (cPLA₂) was detected with immunohistochemical analysis by using phospho-cPLA2(Ser505) antibody, and the contents of thromboxane B₂ (TXB₂) in BALF, malondialdehyde (MDA) in the lungs, and activity of superoxide dismutase (SOD) in lung tissues were also determined.RESULTS:LPS induced acute lung injury, activated cPLA₂, and increased TXB₂ content in the BALF and MDA level in the lung tissue. The pretreatment with berberine significantly attenuated lung injury, lung edema and protein leakage induced by intraperitoneal injection of LPS. The expression of phospho-cPLA₂ in the lung tissues and TXB₂ content in the BALF in the berberine treatment group were lower than those in LPS group (P<0.05). In addition, the content of MDA in the lung tissue was lower in the berberine treatment group than LPS group (P<0.05), but there was no significant difference in activity of lung SOD between the berberine treatment and LPS group (P>0.05). CONCLUSION:Pretreatment with berberine remarkably reduces the LPS-induced lung injury, which is, at least in part, through inhibiting phosphorylation of cPLA₂ and decreasing lipid peroxidation. These findings provide a new strategy for the prevention and treatment of LPS-induced acute lung injury.     

Effects of atorvastatin on cardiac myocyte hypertrophy of neonatal rat induced by angiotensinⅡ in vitro and TLR4 expression

AIM: To assess effects of atorvastatin (Ator) on cardiac myocytes (CM) hypertrophy of neonatal rat induced by angiotensinⅡ (AngⅡ) in vitro and Toll like receptor 4 (TLR4) expression for theoretical bases of preventing and treating myocardial hypertrophy.METHODS: CM of neonatal Sprague-Dawley (SD) rats were isolated with trypsin digestion method and those growth-arrested cells were stimulated with 10^-7 mol/L AngⅡ in the presence of various concentrations of Ator.The method of coomassie brilliant blue was adopted to evaluate the protein contents of CM.The changes in β-MHC,AT₁ receptor and TLR4 mRNA expression were observed by RT-PCR.RESULTS: ① AngⅡ increased the protein content of CM and β-MHC mRNA expression significantly,upregulated AT₁ receptor and TLR4 gene expression.② In a dose-dependent manner,Ator inhibited the increases in the protein contents of CM and β-MHC mRNA expression induced by AngⅡ.③ In a dose-dependent manner,Ator downregulated the AT₁ receptor and TLR4 mRNA expression of CM hypertrophy of neonatal rat induced by AngⅡ.CONCLUSION: Ator inhibits CM hypertrophy,downregulates the AT₁ receptor and TLR4 gene expression.     

Overexpressed human FAT10 protein induces the apoptosis in the starved HEK293 cells

AIM: To study the effect of human FAT10 on the apopotosis of HEK293 cells using flag-tagged human FAT10 protein.METHODS: The fragment of FAT10 gene was cloned into the pcDNA3-flag vector,which was identified by PCR,enzyme digestion and sequencing.The reconstructed plasmids were transfected into HEK293 cells.The expression of introduced FAT10 in the normal cultured and starved cells was detected respectively by Western blotting.XTT assay and DNA ladder method were used to analyze the effect of FAT10 on the apoptosis of starved HEK293 cells.RESULTS: The reconstructed plasmids were highly expressed in HEK293 cells with different expression mode at the mormal cultured and starved state.The livability of starved FAT10 overexpressed HEK293 cells was significantly lower than that of normal cultured cells.DNA ladder was observed in the starved FAT10 overexpressed cells,but not in the normal cultured cells.CONCLUSION: The eukaryotic expressed plasmids of flag-tagged FAT10 were constructed successfully,and highly expressed in HEK293.Overexpressed FAT10 enhances the apoptosis in the starved HEK293 cells.     

马铃薯Y病毒CP基因5'端和3'端反向重复结构介导的抗病性研究

 本研究克隆了来源于马铃薯Y病毒坏死株系(PVY^N)外壳蛋白(CP)基因(PVY^N CP)5'端和3'端的反向重复cDNA序列,并构建了植物表达载体pROKⅡ-5'IR和pROKⅡ-3'IR,利用农杆菌介导的叶盘法转化烟草NC89,分别获得166和126株转基因烟草。抗病性试验表明,转化PVY^N CP基因3'端茎50 bp(环50 bp) hpRNA(hairpin RNA)的烟草抗病率达69%,而转化PVY^N CP基因5'端相同片段长度的hpRNA的烟草却全部发病。Southern blot结果表明,转基因植株的抗病性与转基因的拷贝数之间无明显的相关性;Northern blot结果表明,目的片段转录产物的积累量与植株的抗病性呈负相关,证明所获得的抗病性是RNA介导的抗病性。研究结果证明PVY^N CP基因的3'端比5'端更能有效地诱发基因沉默,并且hpRNA茎部的长度可减少到50 bp。该结果为探索利用CP基因的最短长度和有效部位的基因片段来培育多抗病毒转基因植物提供了依据。     

椰心叶甲饥饿耐受性研究

研究了椰心叶甲的饥饿耐受时间,饥饿状态下的化蛹率和羽化率.结果表明常温下,椰心叶甲幼虫阶段的饥饿耐受时间从长到短分别为5龄幼虫、4龄幼虫、3龄幼虫、2龄幼虫、1龄幼虫,随发育历期的延长饥饿耐受时间逐渐增加.雌成虫的饥饿耐受时间较雄成虫长.饥饿状态下,椰心叶甲幼虫的化蛹率和羽化率随发育历期的延长而逐渐增加.     

噬菌体生物扩增法检测犬结核病

2006年4月12日,四川省崇州市张某将两只贵宾犬(价值80余万元)送四川农业大学兽医院就诊。病犬在成都某宠物医院按照肺炎医治16天,但效果不佳,且症状加剧。在我院经实验室检测,最后确诊为犬结核病。其中一条犬因病情严重,来我     

^3H—BA不同溶解法对脐橙果实吸收^3H—BA的影响

＾３Ｈ－ＢＡ分别采用普通热酒精溶解法,加ＰＴ３９助溶剂的改进溶解法配成＾３Ｈ－ＢＡ＋ＧＡ３,于“清家”脐橙第一次重量落果高峰前涂果,改进溶解法使脐橙幼果在２４小时吸收＾３Ｈ－ＢＡ达２２３８８ｄｐｍ,果内＾３Ｈ－ＢＡ浓度达０．８８×１０＾－６,而普通热酒精溶解法仅分别为１２８９０ｄｍｐ和０．４５×１０＾－６,无论采用哪种方法溶解＾３Ｈ－ＢＡ脐橙幼果对＾３Ｈ－ＢＡ的吸收速度都是果后２４小时内最快,此后     

采后操作对荔枝果实品质、失水与呼吸的影响

探讨了98℃热水处理、熏硫及结合酸浸等技术、包装方式与贮藏条件对‘黑叶’荔枝果实品质、失重与呼吸作用的影响。结果表明：热浸、熏硫结合酸浸处理可提高果皮酸度,对果肉可溶性固形物含量与酸度无影响;无包装自然放置与有孔或无孔塑料盒包装相比,无孔塑料盒包装的果实失重显著减缓;贮藏于4℃的热处理果实与对照果实有相似的失重曲线;无论包装方式与贮藏环境的温湿度如何,果实均不存在呼吸高峰;呼吸速率在贮藏初期随着果实失重的增加而下降,后期变化趋于平稳。