苏云金芽胞杆菌spoⅢD基因缺失突变株的特点

微镜观察和芽胞计数分析显示,突变株基本丧失了形成芽胞的能力,但依然形成晶体.SDS-PAGE结果显示,在SSM培养基中,突变株对伴胞晶体蛋白的形成量影响并不显著;在营养较富集的Luria-Bertani培养基中,突变株中伴胞晶体蛋白的形成量较野生型和互补株明显降低.利用载体pHT315携带spoⅢD操纵子互补突变株,互补株恢复了产生晶体和芽胞的能力.[结论]本研究证明spoⅢD基因是苏云金芽胞杆菌芽胞形成所必需,同时与晶体蛋白的表达相关.     

佛山市土地资源可持续利用探讨

土地资源的持续利用是实现生态、经济和社会可持续发展的基础。着重分析了广东省佛山市土地利用现状特点及存在问题,并在此基础上,提出土地可持续利用的对策与建议。农业用地应采取用地与养地相结合,改善农业生产条件,努力提高单产水平,优化农业用地结构,建设农业生产基地,发展外向型农业,因地制宜地开发未利用土地资源;对非农用地要做好建设用地需求预测工作,统筹规划,城镇用地内函与外延并重;合理调整农业和非农业用地结构;加大土地资源管理的力度,明晰土地产权,完善土地管理制度等。     

High glucose concentration induces endothelial cell proliferation by regulating cyclin‐D2‐related miR‐98

Cyclin D2 is involved in the pathology of vascular complications of type 2 diabetes mellitus (T2DM). This study investigated the role of cyclin‐D2‐regulated miRNAs in endothelial cell proliferation of T2DM. Results showed that higher glucose concentration (4.5 g/l) significantly promoted the proliferation of rat aortic endothelial cells (RAOECs), and significantly increased the expression of cyclin D2 and phosphorylation of retinoblastoma 1 (p‐RB1) in RAOECs compared with those under low glucose concentration. The cyclin D2‐3′ untranslated region is targeted by miR‐98, as demonstrated by miRNA analysis software. Western blot also confirmed that cyclin D2 and p‐RB1 expression was regulated by miR‐98. The results indicated that miR‐98 treatment can induce RAOEC apoptosis. The suppression of RAOEC growth by miR‐98 might be related to regulation of Bcl‐2, Bax and Caspase 9 expression. Furthermore, the expression levels of miR‐98 decreased in 4.5 g/l glucose‐treated cells compared with those treated by low glucose concentration. Similarly, the expression of miR‐98 significantly decreased in aortas of established streptozotocin (STZ)‐induced diabetic rat model compared with that in control rats; but cyclin D2 and p‐RB1 levels remarkably increased in aortas of STZ‐induced diabetic rats compared with those in healthy control rats. In conclusion, this study demonstrated that high glucose concentration induces cyclin D2 up‐regulation and miR‐98 down‐regulation in the RAOECs. By regulating cyclin D2, miR‐98 can inhibit human endothelial cell growth, thereby providing novel therapeutic targets for vascular complication of T2DM.     

Production of L(+)-lactic acid with Rhizopus oryzae immobilized in polyurethane foam cubes

Summary Polyurethane foam cubes were employed as carriers to immobilize Rhizopus oryzae for L(+)-lactic acid production. The immobilizing capacity reached 450 g-fresh cell/l-cube. The production rate of L(+)-lactic acid could be threefold increased by using the immobilized R. oryzae. The immobilized cells could be steadily used in repetitive fermentations for more than 10 batches.     

白木香组织培养及快速繁殖

白木香腋芽外植体在含０．０５ｍｇ／ＬＢＡＰ的ＭＳ基本培养基上增殖系数为４．９３。采用间接法诱导芽生根,生根率达９４．４％。白木香试管苗移栽成活率为９３．８％。     

Proton receptor GPR68 expression in dendritic-cell-like S100β-positive cells of rat anterior pituitary gland: GPR68 induces interleukin-6 gene expression in extracellular acidification

S100β-positive cells, which do not express the classical pituitary hormones, appear to possess multifunctional properties and are assumed to be heterogeneous in the anterior pituitary gland. The presence of several protein markers has shown that S100β-positive cells are composed of populations such as stem/progenitor cells, epithelial cells, astrocytes and dendritic cells. Recently, we succeeded in separating S100β-positive cells into round-cell (dendritic-cell-like) and process-cell types. We also found the characteristic expression of anti-inflammatory factors (interleukin-6, Il-6) and membrane receptors (integrin β-6) in the round type. Here, we further investigate the function of the subpopulation of S100β-positive cells. Since IL-6 is also a paracrine factor that regulates hormone producing-cells, we examine whether a correlation exists among extracellular acid stress, IL-6 and hormone production by using primary cultures of anterior pituitary cells. Dendritic-cell-like S100β-positive cells notably expressed Gpr68 (proton receptor) and Il-6. Furthermore, the expression of Il-6 and proopiomelanocortin (Pomc) was up-regulated by extracellular acidification. The functional role of IL-6 and GPR68 in the gene expression of Pomc during extracellular acidification was also examined. Small interfering RNA for Il-6 up-regulated Pomc expression and that for Gpr68 reversed the down-regulation of Il-6 and up-regulated Pomc expression by extracellular acidification. Thus, S100β-positive dendritic-like cells can sense an increase in extracellular protons via GPR68 and respond by the production of IL-6 in order to suppress the up-regulation of Pomc expression.     

Four New C19-Diterpenoid Alkaloids from Aconitum nagarum Stapf

Four new aconitine-type C₁₉-diterpenoid alkaloids, were isolated from the roots of Aconitum nagarum Stapf which were named as nagarutines A–D ( 1–4 ), together with eleven known compounds ( 5–15 ). The structures of the compounds were identified by IR, HR-ESI-MS, 1D and 2D NMR spectra. All compounds were tested for the inhibitory effect on LPS induced NO production in RAW 264.7 macrophages, compound 7 showed moderate anti-inflammatory activity effect and Inhibition rate is about 44.50%.     

Activated proline‐rich tyrosine kinase 2 regulates meiotic spindle assembly in the mouse oocyte

Proline‐rich tyrosine kinase 2 (PYK2), a member of the protein tyrosine kinase family, plays an important role in various cellular processes. PYK2 can be phosphorylated on tyrosine 402 by diverse stimuli at the cell surface, and recent studies have shown that this activated form of PYK2 is enriched in oocytes and required for fertilization. However, the subcellular localization and functions of activated PYK2 in oocytes remain elusive. In this study, we demonstrate that the localization of p‐PYK2 undergoes dynamic changes during in vitro maturation of mouse oocytes. The signal of p‐PYK2 is initially dispersed in the cytoplasm, but begins to decorate organized microtubules after the germinal vesicle breakdown and localizes to spindle poles at metaphase. Our data further show that p‐PYK2 colocalizes with γ‐tubulin from the germinal vesicle stage through the end of meiosis in mouse oocytes. Nocodazole treatment and washout experiments confirm that p‐PYK2 associates with the oocyte spindle and spindle poles. Moreover, pharmacological inhibition of PYK2 activity dramatically alters the morphology of the bipolar spindle and prevents oocyte maturation. Together, these data suggest that activated PYK2 may function as a component of the microtubule organizing center to regulate spindle assembly during the meiotic process of mouse oocytes.     

Contact Toxicity and Repellency of the Essential Oil from Mentha haplocalyx Briq. against Lasioderma serricorne

The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Mentha haplocalyx was investigated by GC‐FID and GC/MS analyses. In sum, 23 components, representing 92.88% of the total oil composition, were identified, and the main compounds were found to be menthol (59.71%), menthyl acetate (7.83%), limonene (6.98%), and menthone (4.44%). By bioassay‐guided fractionation (contact toxicity), three compounds were obtained from the essential oil and identified as menthol, menthyl acetate, and limonene. The essential oil and the three isolated compounds exhibited potent contact toxicity against Lasioderma serricorne adults, with LD₅₀ values of 16.5, 7.91, 5.96, and 13.7 μg/adult, respectively. Moreover, the oil and its isolated compounds also exhibited strong repellency against L. serricorne adults. At the lower concentrations tested and at 2 h after exposure, menthol showed even significantly stronger repellency than the positive control DEET. The study revealed that the bioactivity properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components, which indicates that the M. haplocalyx oil and its isolated compounds have potential for the development as natural insecticides and/or repellents to control insects in stored grains and traditional Chinese medicinal materials.