颈静脉灌注精氨酸对泌乳中期奶牛血清生化和免疫指标的影响

本文旨在研究颈静脉灌注精氨酸对泌乳中期奶牛血清生化和免疫指标的影响。采用3×3复式拉丁方试验设计,选择6头体重、胎次、泌乳期、泌乳量和体况基本一致的荷斯坦奶牛为试验动物,随机分为3组(每组2头),分别为酪蛋白组(对照组)、精氨酸组(灌注37.66 g/d)、丙氨酸组(与精氨酸组等氮,灌注77.24 g/d);每个试验期为22 d(7 d灌注+15 d间隔),在每个试验灌注期的最后1 d晨饲前采血,测定血清生化和免疫指标。结果表明:精氨酸组的奶牛血清中总蛋白、免疫球蛋白G(Ig G)、肿瘤坏死因子α(TNF-α)浓度要显著高于其他2组(P0.05),白球比、白细胞介素1(IL-1)浓度显著高于丙氨酸组(P0.05),但是牛奶中体细胞数显著低于其他2组(P0.05),而血清中谷丙转氨酶、谷草转氨酶活性,免疫球蛋白A(Ig A)、免疫球蛋白E(Ig E)、白细胞介素6(IL-6)浓度在组间无显著差异(P0.05)。综上,灌注精氨酸能够通过提高血清总蛋白、Ig G及IL-1、TNF-α的浓度,从而一定程度上增强泌乳奶牛机体的免疫力和胎儿的被动免疫力。     

Functional changes of retinal ganglion cells in rd1 mice during midterm of retinal pigmentosa

AIM: To investigate how the function of retinal ganglion cells (RGCs) change in the midterm of retinal pigmentosa (RP) in rd1 mice (a transgenic animal model of RP). METHODS: The action potentials from multiple RGCs in rd1 mice at postnatal 20 d (P20) or normal C57 mice (control) were simultaneously recorded by multi-electrode array recording. The functional changes of surviving ganglion cells were evaluated by comparing spontaneous and light-evoked activities of RGCs between rd1 and control mice. The extent of photoreceptor degeneration was verified by immunohistochemical staining. RESULTS: Immunohistochemistry results showed the thickness of the retinal photoreceptor layer of rd1 mice was significantly lower than that in normal mice at P20. According to the light response properties, we classified ganglion cells into 6 subgroups: ON sustained, ON transient, ON-OFF sustained, ON-OFF transient, OFF sustained and OFF transient RGCs, with a very tiny percentage of OFF sustained RGCs (1.0%~3.1%). The percentage of RGCs remaining light responsive in rd1 mice was significantly lower than that in C57 mice. The average spontaneous spiking rate for rd1 RGCs was overall significantly increased compared to that in C57 cells, whereas different RGC types had different changes. The light-induced responses and light sensitivities of all types of RGCs in rd1 mice were both significantly lower than those in C57 mice. CONCLUSION: The photoreceptors of rd1 mice are severely degenerated in the midterm of retinal degeneration. The functions of RGCs in rd1 mice in the midterm of degeneration decay obviously, with variance in different RGCs types.     

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.     

Estrogen treatment enhances mesenteric lymphatic contractility in rats after hemorrhagic shock

AIM To investigate the effects of 17β-estradiol （E2） treatment on the mesenteric lymphatic microcirculation and isolated lymphatic contractility in rats after hemorrhagic shock, and to explore the relationship between contractility and the difference between intra- and extracellular calcium ion concentrations （［Ca²⁺］） of lymphatic smooth muscle cells （LSMCs）. METHODS Male Wistar rats were divided into sham group, shock group and shock+E2 group. The rats were subjected to hemorrhage ［（40±2） mmHg for 90 min］ and resuscitation with or without subcutaneous injection of E2 （2 mg/kg）. After resuscitation for 3 h, the mesenteric lymphatic microcirculation in vivo was observed. Moreover, the isolated mesenteric microlymphatic rings were prepared for the observations of lymphatic contractility evaluated by the indexes including end-systolic diameter, end-diastolic diameter, contraction frequency （CF） and passive diameter. Meanwhile, the difference between intra- and extracellular ［Ca²⁺］ of LSMCs was recorded during lymphatic contraction. RESULTS Treatment with E2 significantly enhanced the CF, total contractile fraction and lymphatic dynamics index in vivo in the rats after hemorrhagic shock, and increased the CF, the fractional pump flow and the difference between intra- and extracellular ［Ca²⁺］ of LSMCs in isolated lymphatics from the shocked rats （P<0.05）. CONCLUSION Estrogen treatment enhances lymphatic contractility in rats after hemorrhagic shock, which is related to enhancement of difference between intra- and extracellular ［Ca²⁺］ of LSMCs.     

Physiological and pathological roles of mast cells in adipose tissue

Mast cells are important cells for the innate immunity that reside in tissues including adipose tissue and are involved in various physiological and pathological processes by producing a range of biological mediators. Adipose tissue not only acts as an energy depot and regulator of energy homeostasis that can deposit excess energy and dissipate energy through heat, but also is an active endocrine organ capable of producing hormones and adipokines. The dysfunction of adipose tissue is highly correlated with metabolic disorders, such as obesity, type 2 diabetes mellitus and so on. This review focuses on the physiological and pathological roles of mast cells in adipose tissue.     

内毒素对肠黏膜微血管内皮细胞内分泌一氧化氮和内皮素的影响

目的是研究内毒素（lipopolysaccharide; LPS）导致肠黏膜微血管内皮细胞损伤的作用机制。将所培养的肠黏膜微血管内皮细胞分为空白对照组和LPS组，每组按时间分为4个亚组：3h、6h、9h、12h。空白对照组加维持培养液，LPS组加1μg/ml LPS培养液，在CO2培养箱内静置培养。结果表明，一氧化氮（NO）分泌明显升高，3h后达到高峰，随后逐渐降低，而内皮素（endothelin; ET）分泌急剧升高，9h后达到高峰，随后又开始逐渐降低，但一直保持在较高的水平。所以引起了NO和ET的升高可能是LPS导致肠黏膜微血管内皮细胞的损伤机制。     

Biodegradation of Linear Alkyl Benzene Sulphonate

The paper researches on the degradation of LAS (Linear Alkyl benzene Sulphonate) by combining AS1.860 immobilized with low intensity ultrasonic irradiation. The paper also discusses the influence of pH, rotary velocity, LAS concentration and the condition of low intensity ultrasonic irradiation on the degradation of LAS, the degradation rate of LAS is the main index of our experiment, the results of orthogonal test shows that low ultrasonic irradiation can increase the metabolizing of microorganism cells and facilitate the biodegradation of immobilized cells to LAS, here we research the degradation condition of 50mg/L LAS simulation wastewater with low ultrasonic irradiation, and the results show that the influence is obvious, the optimization degradation rate is about 83%, nine point five percent higher than that of the immobilized cells without ultrasonic irradiation.     

大丽轮枝菌粗毒素在棉花根冠细胞生物学测定方法上的研究

在棉花根冠细胞生物测定过程中,棉花黄萎病病菌通过提纯复壮而达到较强的侵染能力,并制备出较多的黄萎病菌粗毒素。介绍了粗毒素的简易制备、根冠细胞培养与制备过程以及染色过程中染色剂的选择、染色时间的长短。实验与传统方法相比有几点改进:总结出细胞振荡时间在1~2 min之内;之后黑暗条件下静置培养2~6 h;选用pH为6.5的0.01%中性红染色3~5 min,之后加入一滴0.2%伊文思兰染色,伊文思兰的染色时间应严格掌握在3min以内等,为根冠细胞测定方法的推广提供了一定的理论支持。     

小鼠ES细胞在不同饲养层上培养nanog基因的 表达水平与生长行为

观察小鼠ES-D3细胞在MEF、新生牛睾丸支持细胞(nBTSCs)和新生兔睾丸支持细胞(nRTSCs)饲养层上生长4 d nanog基因的表达水平和生长行为。RT-PCR分析显示，MEF饲养层上培养4d的ES-D3 nanog基因含量高；nBTSC饲养层上培养nanog基因表达较低；而RTSC饲养层上培养nanog基因表达最低。结果显示：不同饲养层上的ES-D3细胞集落形态和培养4d分化程度有差异。在MEF饲养层上的ES-D3细胞培养4d，集落形态仍然很规则，细胞间紧密，集落表面少见大细胞，AKP染色强阳性。在nBTSC饲养层上的ES-D3细胞，集落界限清晰，AKP染色显示，集落大部分细胞呈阳性，少数的细胞集落为弱阳性，可见集落表面分散有较多的大细胞。在nRTSC饲养层上的饲养层上的ES-D3，集落隆起不明显，集落界限不清晰，大部分集落形态不太规则，AKP染色显示集落中部分细胞呈阳性，少数的细胞集落为全阴性，集落表面有较少的大细胞，集落周围有伸出的成纤维细胞。