Effects of psychological stress on in vitro expression of activated surface molecules on T cells of peripheral blood from healthy persons

AIM: To study cellular and molecular mechanism involved in increasing susceptibility of infection in psychological stress persons. METHODS: Comparative studies were performed with double staining and flow cytometry analysis on immunophenotyping and in vitro expression of early activating surface molecule CD69 in response to mitogens on T cells from peripheral blood of 20 healthy college student volunteers before and after psychological stress. A series of term final examinations was defined as psychological stress. RESULTS: Immunophenotyping analysis showed no statistically significant difference in the percentage of CD2, CD3, CD4, CD8, CD19, CD20, CD16 and CD56 positive lymphocyte populations before and after psychological stress. There was a statistically significant decrease in the in vitro expression of CD69 in response to polyclonal stimulators on the T cells from persons after psychological stress than those before psychological stress. The percentage of CD69 expression (CD69⁺CD3⁺/CD3⁺%) in response to PHA and PDB in the whole blood culture for 72 hours decreased respectively from 28.1±4.1 and 80.7±6.8 on the T cells obtained before psychological stress to 17.6±3.8 and 65.8±7.9 on those obtained after psychological stress, while there was no statistically significant difference between the CD69 expression rates without stimulators on the T cells obtained before and after psychological stress. CONCLUSIONS: The effects of psychological stress to immune system is not on the level of changing proportions of the sub-populations within peripheral blood lymphocytes. Psychological stress can decrease the activating response of T cells in healthy persons, which may be responsible for the increase of susceptibility to infection in the psychological stress persons.     

中华鲟胚胎细胞的冷冻保存及其核移植

为了保存濒危鱼类中华鲟种质资源,对其囊胚细胞和原肠细胞进行了冷冻保存和核移植试验。用二甲亚砜(DMSO)、1,2-丙二醇(PG)、羟乙基淀粉(HES)3种抗冻剂,配制4种冷冻保护液:CP1(12%D)、CP2(10%P)、CP3(8%D 6%E)、CP4(7%P 6%E),冷冻细胞存活率分别为47.4%±4.7%、64.4%±3.6%、54.7%±4.7%、76.7%±5.7%,CP4保存效果最好,说明添加非渗透型抗冻剂羟乙基淀粉能提高冷冻保存细胞的存活率。比较了两种冷冻方法,发现细胞在-7℃平衡30min之后直接投入液氮的一步冷冻降温法是可行的。对不同发育时期的胚胎细胞冷冻存活率进行了比较,结果表明原肠细胞冷冻存活率(64.4%±11.8%)明显比囊胚细胞的(57.1%±11.2%)高(P<0.05)。用冷冻复苏后的囊胚细胞和原肠细胞作供体,以中华鲟未受精卵作受体进行核移植,各移植了469和392枚卵,分别获得了5尾和2尾克隆鱼,核移植成功率分别为1.1%和0.5%。表明可通过冷冻保存胚胎细胞结合核移植技术保存鱼类种质资源。     

副溶血弧菌VP-5的分离鉴定及其与鲈鱼免疫信号通路相互关系研究

为探讨福建省漳州市盛明养殖场鲈鱼的致病菌及其与鲈鱼免疫信号通路的相互关系,从而可以预防和治疗该疾病。解剖患病鲈鱼肝脏组织后划线培养分离纯化了致病菌VP-5。显微镜观察该致病菌VP-5形态为球杆状,弧形,有单鞭毛,运动活跃,革兰阴性菌。在VITEK-32全自动微生物分析仪鉴定后,该致病菌对酪氨酸、葡萄糖、甘露醇等反应阳性,对蔗糖,阿拉伯糖和棉子糖等反应阴性。分析了该致病菌16SrRNA和tdh1基因序列,发现其与副溶血弧菌的亲缘关系非常接近。综合后鉴定致病菌VP-5为副溶血弧菌。并研究了副溶血弧菌VP-5侵染鲈鱼后寄主免疫信号通路基因cd63/cxcr4/il-8的表达水平差异。鲈鱼腹腔注射感染副溶血弧菌VP-5,感染后0-96h解剖鲈鱼肝脏组织和表皮组织。采用Trizol试剂盒抽提鲈鱼总RNA,反转录后生成cDNA。利用实时荧光定量PCR技术对鲈鱼免疫信号通路基因cd63/cxcr4/il-8表达水平进行测定。鲈鱼受到副溶血弧菌VP-5感染后,免疫信号通路基因cd63/cxcr4/il-8在鲈鱼肝脏组织的表达量12h和24h时与对照组相比较差异显著(P<0.05);在表皮组织的表达量在24h和36h时与对照组相比较差异显著(P<0.05)。证实鲈鱼肝脏组织免疫信号通路基因的表达与副溶血弧菌VP-5的感染正相关,相对于表皮组织反应更快。因此鲈鱼的免疫信号通路基因cd63/cxcr4/il-8积极反应于致病菌,这些基因的快速表达会引发鲈鱼自身免疫应答,增强其抵抗致病菌的能力。     

温湿度调控对番茄灰霉病菌产生的细胞壁降解酶的影响

 番茄灰霉病菌在致病过程中能够产生4种细胞壁降解酶,以PMG酶活性最高,其次是β-葡萄糖苷酶和PG酶,Cx最少。灰霉病菌在不同温度下侵染番茄叶片时产生的致病酶活性不同,4种酶在20℃时表现了最高的活性,15℃次之,当温度达到25℃时,各种酶的活性都急剧下降,随着温度的再升高,酶活更低。随着湿度的增高,病菌产生的细胞壁降解酶的活性也增加,当相对湿度达到90%以上时,4种酶的活性也达到最高。温湿度对番茄灰霉病菌产生细胞壁降解酶的影响趋势,与其对发病的影响趋势是一致的。     

Expression of natural killer cell stimulatory receptor NKG2D and its ligand MICA in Tibetan patients with gastric cancer at Qinghai plateau

AIM: To investigate the expression of natural killer cell stimulation receptor D(NKG2D) in peripheral blood and the expression of major histocompatibility complex class I chain-related protein A(MICA) on the gastric carcinoma tissue and the neighboring non-cancerous tissue in Tibetan patients with gastric cancer at Qinghai plateau. METHODS: Samples of 33 patients and 20 healthy persons were collected to detect NKG2D in peripheral blood by Flow cytometry analysis. The expressions of MICA in part of the correspondent tissues were examined by RT-PCR and immunohistochemistry.RESULTS: The expression of NKG2D in the plateau of Tibetan patients with gastric cancer group (13.47 ±5.26)% was significantly lower than that in healthy groups (32.62±10.08)%. The mRNA level of MICA in gastric cancer was significantly higher than that in neighboring non-cancerous tissue (P<0.05). The expressions of MICA proteins showed a significant difference between the neighboring non-cancerous tissue (21.21%, 7/33) and the gastric carcinoma tissue (78.79%, 26/33), between the high differentiation (60.00%, 3/5) and the moderate (72.73%, 8/11), low differentiation (88.24%, 15/17). The expressions of MICA were not correlated with tumor size, sex, age, lymph node metastasis of the patients (P>0.05). Spearman rank correlation displayed that the expressions of MICA mRNA were positively correlated with the MICA protein level (r=0.903, P<0.01).CONCLUSION: The immune escape in Tibetan patients with gastric cancer at Qinghai plateau probably relates to the down-regulation of NKG2D and the up-regulation of its ligand MICA. The activity of NK cells and the anti-cancer cellular immunity level are descending in the plateau of Tibetan patients with gastric cancer. The decrease in the receptor NKG2D is a reason for the activity of NK cell descending.     

早熟马铃薯新品种洛马铃薯8号的选育

洛马铃薯8号由“中薯3号x秦芋30号”杂交选育而成。早熟,生育期66d,休眠期中等,51d左右。薯块卵圆形,黄皮黄肉,薯皮光滑,芽眼浅,薯块较整齐,平均单株薯块数2．5个,单薯质量104．72g,商品薯率94．46％,淀粉含量13．6％,VC含量24．4m~100g,蛋白质2．70％,还原糖含量0．19％,较抗病毒病和晚疫病．667m2产量1302．04kg以上,适宜中原二季作区春秋两季种植。     

四倍体甜瓜花粉母细胞减数分裂的观察

以同源四倍体甜瓜为材料,采用常规压片法研究花粉母细胞减数分裂行为。结果表明:同源四倍体甜瓜花粉母细胞减数分裂过程与二倍体类似,但有其特殊性。主要表现在:粗线期观察到有6.7%的细胞出现双核;终变期的四倍体染色体构型较复杂,有二价体、多价体、三价体和单价体;中期I和中期II有赤道板外染色体;后期I和后期II出现染色体桥和落后染色体;四分体时期出现二分体、三分体和多分体。花粉母细胞减数分裂的异常是同源四倍体甜瓜育性低的细胞学原因。     

鹿茸干细胞体外培养技术的研究

利用消化酶消化法,用DMEM培养基对鹿茸干细胞进行了体外培养,分别从原代培养、传代、冻存、以及复苏等几个环节进行了试验。摸索鹿茸干细胞合适的体外培养条件,为鹿茸的各项相关研究打基础。结果表明,用透明质酸酶和胶原酶对组织样进行消化,然后用10%DMEM培养基进行培养细胞生长效果较好。适宜培养条件是37℃、5%CO2最大饱和湿度。     

含PRRS病毒ORF5的伪狂犬病病毒TK基因缺失转移载体的构建

提取伪狂犬病病毒（ＰＲＶ）ＢａｒｔｈａＫ６１株基因组ＤＮＡ,用限制性内切酶ＫｐｎＩ充分消化,回收５．９ｋｂ片段（Ｊ片段）,将其克隆于质粒ｐＵＣ１１９ ＫｐｎＩ位点上,获得ｐＢＫＪ。用两对针对ＰＲＶ ＴＫ基因的特异性引物对重组质粒进行ＰＣＲ鉴定,证明其中含有ＰＲＶ ＴＫ基因。然后用ＫｐｎＩ、ＰｓｔＩ和ＢａｍＨＩ等限制性内切酶对其进行酶切分析,确定了克隆片段的物理图谱。进一步研究证实ＴＫ基因位于其中的