Moisture Movement and Transformation Law under Soil Moisture Conserving Irrigation in Winter Wheat Field

[Objective] The aim was to provide theoretical basis for field moisture conserving irrigation.[Method] With Xiaoyan No.6 as tested material,three different kinds of mulching irrigation treatments were carried out （straw mulching;plastic mulching;PAM control adjustment mulching）.With non-mulching treatment as control,moisture conserving effect of different treatments were compared.[Result] The results showed that the water consumption of winter wheat under different soil moisture conservation treatments was low at earlier stage and later stage,but high at mid-stage,which was consistent with the water consumption law of control.There were some differences in terms of consumption intensity because of irrigation schedule and growth condition;soil moisture conservation treatments could restrain ineffective evaporation of soil moisture before anthesis.We also found that the variation of soil moisture at depth of 0-20 cm in PAM and control treatment was dramatic.The soil moisture of the former was lower than the latter at the depth of 0-20 cm,but higher at the depth of 20-50 cm.The difference of soil moisture at the depth of 0-50 cm was significant.[Conclusion] Plastic mulching and straw mulching could restrain evaporation effectively.

Targeted migration and differentiation of engrafted neural precursor cells in amyloid β-treated hippocampus in rats

Objective To observe the migration and differentiation of the neural precursor cells （NPCs） that derived from murine embryonic stem cells （ESCs） when they were transplanted into amyloid β （Aβ）-treated rat hippocampus. Methods MESPU35, a murine ESC cell line that express the enhanced green fluorescent protein （EGFP）, was induced differentiation into nestin-positive NPCs by modified serum-free methods. The Aβ plaques and the differentiation of the grafted cells were observed by immunofluorescent staining. Results Comparing 16 weeks with 4 weeks post-transplantation, the migration distance increased about 5 times; the rate of migratory NPCs differentiating into glial fibrillary acidic protein （GFAP）-positive cells kept rising from （30.41 ± 1.45）% to （49.25± 1.23）%, and the rate of NPCs differentiating into neurofilament 200 （NF200） positive cells increased from （16.68±0.95）% to （27.94± 1.21）%. Meanwhile, the GFAP-positive cells targeting to the ipsilateral side of Aβ plaques increased from 60.2% to 81.3 %, while the NF200-positive cells increased from 61.3% to 84.1%. The migration distance had significant positive linear correlations to the neuronal differentiation rate （r = 0.991） and to the astrocytic differentiation rate （r = 0.953）. Conclusion Engrafted NPCs migrate targetedly to the Aβ injection site and differentiate into neurons and astrocytes.

表皮干细胞及其信号通路的研究进展

1 表皮干细胞特点及其在创伤愈合中的作用皮肤是人体最大的器官,表皮位于皮肤最外层,具有自我更新能力的组织(约每个月更新1次)[1].近年来,人们逐渐认识到存在于上皮组织的成体干细胞ESCs与皮肤的发生、修复、改建以及与上皮源肿瘤、皮肤免疫性疾病有着密切关系.在正常成人表皮基层主要含有三种细胞亚群维持着其新陈代谢:①表皮干细胞;②表皮干细胞的子代细胞-短暂扩充细胞(TA,类似定向祖细胞);③有丝分裂后分化细胞(Postmitotic differentiating cells, PM-D Cells),表皮脚及毛囊隆突部表皮干细胞向表皮迁移分化为表皮祖细胞,为表皮新陈代谢提供细胞源;向下迁移,为毛囊循环周期提供细胞源.

Transplanted neuronal precursors migrate and differentiate in the devel-oping mouse brain

The subventricular zone (SVZ), lining the lateral ventricle in forebrain, retains a population of neuronal precursors with the ability of proliferation in adult mammals. To test the potential of neuronal precursors in adult mice, we transplanted adult SVZ cells labeled with fluorescent dye PKH26 into the lateral ventricle of the mouse brain in different development stages. The preliminary results indicated that the grafted cells were able to survive and migrate into multiple regions of the recipient brain, including SVZ, the third ventricle, thalamus, superior colliculus, inferior colliculus, cerebellum and olfactory bulb etc; and the amount of survival cells in different brain regions was correlated with the development stage of the recipient brain. Immunohistochemical studies showed that most of the grafted cells migrating into the specific target could express neuronal or astrocytic marker. Our results revealed that the neuronal precursors in adult SVZ still retained immortality and ability of proliferation, which is likely to be induced by some environmental factors.

Cell transformation as aberrant differentiation: Environmentally dependent sportaneous transformation of NIH 3T3 cells

NIH 3T3 cells, a mouse fibroblast cell line used as routine target cells for transfection experiments, undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal bovina serum (FBS) or lower coneentrafcion of calf serum (CS). The transformation takes the form of foci of multiplying cells among the surrounding cells which have stopped cell division. However, no focus of transformed cells could be seen in medium containing high concentration (10%) of OS. Further experiments indicated that the frequency of transformation is highly dependent on the concentration of serum and the transformation in OS is changeable when the cells are passaged in FBS. 8H-thymidine autoradiography has been proved to be a sensitive measurement indicator for foous formation. Our results suggest that the high frequency of transformation and its dependence on confmenoy as well as on medium composition are characteristics of cell differentiation rather than mutation. The role of the NIH 3T3 cell line as a cancer-initiated cell population and its accelerated transformation by rat oncogene might be considered as a form of tumor promotion is discussed.

溃疡性结肠炎与骨髓间充质干细胞的研究进展及中医药治疗新思路

溃疡性结肠炎(UC)病程迁延、无法治愈。间充质干细胞(MSCs)是一种具有多向分化潜能的细胞,研究表明其通过对损伤部位的免疫调节,或间质细胞分化,能够促进UC肠黏膜屏障的重建。结肠黏膜干细胞数量减少从而导致病变黏膜损伤以及骨髓干细胞转分化为结肠黏膜干细胞和上皮细胞的情况值得研究,这有可能从根本上治疗该病提供新思路。文章就其中有关MSCs迁移分化与UC的研究进展进行综述,并分析中医药治疗与MSCs的关系,以便更全面的研究中医药治疗UC的作用机制。