Full-length enriched multistage cDNA library construction covering floral bud development in Populus tomentosa

Flowering involves expression of a suite of genes associated with floral development. The genome of the Chinese white poplar (Populus trichocarpa) was sequenced because of its importance as a model tree for genetic studies as well as being an economically important woody plant. However, information on expressed genes involved in poplar floral bud development is insufficient to allow annotation of genes and use of the genomic information. To isolate and characterize genes involved in flowering of Populus tomentosa, floral bud samples were collected at different developmental stages from floral bud initiation to flower maturity, and full-length enriched cDNA libraries from both male and female floral buds were constructed. The results of titer analysis showed that the titer of the female and male primary libraries were 8.00 × 105 and 7.20 × 105 pfu/ml, respectively, and the titer of the amplified libraries were 2.60 × 108 and 2.56 × 108 pfu/ml, respectively. The combination ratio reached 90% and the insert size was 400 to 2000 bp. The results indicated that cDNA libraries were successfully constructed.Keywords: cDNA library, floral bud, flowering, Populus tomentosaAfrican Journal of Biotechnology Vol. 11(29), pp. 7373-7377, 10 April, 201

Knockdown of Rab5a expression decreases cancer cell motility and invasion through integrin-mediated signaling pathway

<p>Abstract</p> <p>Background</p> <p>Rab GTPases function as modulators in intracellular transport. Rab5a, a member of the Rab subfamily of small GTPases, is an important regulator of vesicle traffic from the plasma membrane to early endosomes. Recent findings have reported that Rab5a gene was involved in the progression of cancer. In the present study, we investigated the effect of Rab5a on cervical cancer invasion and metastasis and the molecular mechanism underlying the involvement of Rab5a.</p> <p>Methods</p> <p>Rab5a expression was assessed by immunohistochemical analysis on a cervical cancer tissue microarray. RNA interference (RNAi) was performed to knock down the endogenous expression of Rab5a gene in HeLa and SiHa cells. Cell motility was evaluated using invasion assay and wound migration assay <it>in vitro</it>. The expression levels of integrin-associated molecules were detected by Western blot and immunofluorescence.</p> <p>Results</p> <p>We found that Rab5a was expressed at a high level in cervical cancer tissues. Silencing of Rab5a expression significantly decreased cancer cell motility and invasiveness. The down-regulation of integrin-associated focal adhesion signaling molecules was further detected in Rab5a knockdown cells. Meanwhile, active GTP-bound Rac1, Cdc42, and RhoA were also down-regulated, accompanied with the reduction in the number and size of filopodia and lamellipodia.</p> <p>Conclusions</p> <p>Taken together, these data suggest that Rab5a functions in regulating the invasion phenotype, and we propose that this regulation may be via integrin-mediated signaling pathway in cervical cancer cells.</p

Geometric bionics: Lotus effect helps polystyrene nanotube films get good blood compatibility

Various biomaterials have been widely used for manufacturing biomedical applications including artificial organs, medical devices and disposable clinical apparatus, such as vascular prostheses, blood pumps, artificial kidney, artificial hearts, dialyzers and plasma separators, which could be used in contact with blood^1^. However, the research tasks of improving hemocompatibility of biomaterials have been carrying out with the development of biomedical requirements^2^. Since the interactions that lead to surface-induced thrombosis occurring at the blood-biomaterial interface become a reason of familiar current complications with grafts therapy, improvement of the blood compatibility of artificial polymer surfaces is, therefore a major issue in biomaterials science^3^. After decades of focused research, various approaches of modifying biomaterial surfaces through chemical or biochemical methods to improve their hemocompatibility were obtained^1^. In this article, we report that polystyrene nanotube films with morphology similar to the papilla on lotus leaf can be used as blood-contacted biomaterials by virtue of Lotus effect^4^. Clearly, this idea, resulting from geometric bionics that mimicking the structure design of lotus leaf, is very novel technique for preparation of hemocompatible biomaterials

Heterodichogamy in Kingdonia (Circaeasteraceae, Ranunculales)

Background and Aims Preliminary field observations in 2001 and 2002 suggested that Kingdonia uniflora (Circaeasteraceae, Ranunculales) exhibits heterodichogamy, an unusual kind of reproductive heteromorphy, hitherto unreported in Ranunculales and known from only one other genus in basal eudicots. Methods During several subsequent years flowers were observed in the field. Flowers were fixed in FAA and studied with microtome sections series and with the scanning electron microscope. Key Results The flowers proved to be heterodichogamous, with protandrous and protogynous morphs, which have a 1 : 1 ratio. Both morphs equally set fruit. Each year a single flower is formed at the tip of a rhizome or more rarely two flowers. The flowers are already open when they appear at the soil surface, before they are receptive and before pollen is dispersed. In both floral morphs the styles elongate early and the stigmas are positioned above the anthers before anthesis begins. In protogynous flowers the stigmas become receptive in this position; later the styles become reflexed and then the anthers dehisce. In contrast, in protandrous flowers the stamen filaments elongate during early anthesis such that the dehiscing anthers come to lie above the (still unreceptive) stigmas; after dehiscence of all anthers in a flower the styles begin to elongate and become receptive. Conclusions This is the first record of heterodichogamy in a representative of Ranunculales, in an herbaceous eudicot, and in a plant with uniflorous ramets. The occurrence of heterodichogamy in Kingdonia in which clonal reproduction appears to be dominant might be an adaptation to avoid mating between the ramets from a common mother individual (genet

Leukotriene B4, administered via intracerebroventricular injection, attenuates the antigen-induced asthmatic response in sensitized guinea pigs

<p>Abstract</p> <p>Background</p> <p>Despite intensive studies focused on the pathophysiology of asthmatic inflammation, little is known about how cross-talk between neuroendocrine and immune systems regulates the inflammatory response during an asthmatic attack. We recently showed corresponding changes of cytokines and leukotriene B₄(LTB₄) in brain and lung tissues of antigen-challenged asthmatic rats. Here, we investigated how LTB₄interacts with the neuroendocrine-immune system in regulating antigen-induced asthmatic responses in sensitized guinea pigs.</p> <p>Methods</p> <p>Ovalbumin-sensitized guinea pigs were challenged by inhalation of antigen. Vehicle, LTB₄or U75302 (a selective LTB₄BLT1 receptor inhibitor) was given via intracerebroventricular injection (i.c.v.) 30 min before challenge. Airway contraction response was evaluated using Penh values before and after antigen challenge. The inflammatory response in lung tissue was evaluated 24 h after challenge. The LTB₄content of lung and brain homogenate preparations was detected by reversed phase high-performance liquid chromatography (RP-HPLC). Plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were measured using ELISA kits.</p> <p>Results</p> <p>Antigen challenge impaired pulmonary function and increased inflammatory cell infiltration in lung tissue. These responses could be significantly suppressed by LTB₄, 30 ng i.c.v., in ovalbumin-sensitized guinea pigs. LTB₄content of lung and brain homogenates from antigen-challenged guinea pigs was significantly increased. In addition, administration of LTB₄via i.c.v. markedly increased CORT and ACTH level in plasma before antigen challenge, and there were further increases in CORT and ACTH levels in plasma after antigen challenge. U75302, 100 ng i.c.v., completely blocked the effects of LTB₄. In addition, U75302, 100 ng via i.c.v. injection, markedly decreased LTB₄content in lung homogenates, but not in brain homogenates.</p> <p>Conclusions</p> <p>Increased LTB₄levels in brain during asthmatic attacks down-regulates airway contraction response and inflammation through the BLT1 receptor. Stimulation of the hypothalamic-pituitary-adrenal axis by LTB₄may result in an increase in systemic glucocorticoids which, in turn, would feed back to suppress the asthmatic response.</p

Protective effect of fasudil hydrochloride against acute renal injury in septicopyemia rats

AbstractObjectiveTo observe the protective effect of fasudil hydrochloride against acute renal injury in septicopyemia rats.MethodsA total of 60 Wister rats were included in the study and divided into control group (n = 10), model group (n = 25) and treatment group (n = 25). Model group and treatment group received intraperitoneal injection of endotoxin (ET) to establish acute renal injury models while the control group only received daily intraperitoneal injection of normal saline 1 mL. Five rats were taken out of model group and treatment group respectively at 1 h (T1), 6 h (T2), 12 h (T3), 24 h (T4) and 48 h (T5), for intraperitoneal injection of ET 30 mg/kg. Treatment group received intraperitoneal injection of fasudil hydrochloride 30 mg/kg 1 h before injection of ET. For three groups, 5 mL blood samples were collected from postcava for determination of serum creatinine and urea nitrogen levels at different time points. Concentrations of serum tumor necrosis factor α and ET-1 were determined by using ELISA. The renal pathologic changes were observed under the microscope.ResultsSerum creatinine levels in both model group and treatment group were significantly higher than control group at T2–T5 (P < 0.05) while the levels in treatment group were significantly lower than control group at T3–T5 (P < 0.05). At T2–T5, blood urea nitrogen levels in model group and treatment group were significantly higher than control group (P < 0.05) while the levels in treatment group were significantly lower than model group at T3–T5 (P < 0.05). Concentrations of serum tumor necrosis factor α in model group and treatment group were significantly higher than control group at T1–T5 (P < 0.05) while the levels in treatment group were significantly lower than model group at T1–T5 (P < 0.05). Serum ET-1 concentrations in model group and treatment group were significantly higher than control group at T1–T5 (P < 0.05) while the levels in treatment group at T1–T4 were significantly lower than model group (P < 0.05). Rats in control group showed no swelling or hyperemia in kidney cells but normal structure and normally arranged renal tubular epithelial cells. Obvious injury was observed in model group at T3 and renal tubular epithelial cells in disorder and at swelling condition, hyperemia and angiectasis in glomerulus, degenerative opacities and vacuolar degeneration, and maximized injury were observed at T4. Injury in renal tissue in treatment group was significantly milder than model group.ConclusionsFasudil hydrochloride has the significantly protective effect against acute renal injury in septicopyemia rats

Ionic Liquids Catalysis for Carbon Dioxide Conversion With Nucleophiles

Carbon dioxide, as a promising C1 synthon, has attracted great interest in organic synthesis. Due to the thermodynamic stability and kinetic inertness of CO2, developing efficient strategies for CO2 activation and subsequent conversion is very crucial. In this context, Ionic liquids (ILs) show great potential for capturing and activating CO2 owing to their unique structures and properties, making them become ideal alternatives to volatile organic solvents and/or catalysts for CO2 transformation. This minireview aims at summarizing ILs-promoted reactions of CO2 with N-nucleophiles (primary amines)/O-nucleophiles (primary alcohols, water). Two catalytic systems i.e., metal/ILs binary systems such as Cu/ILs systems and Ag/ILs systems as well as single ILs systems including anion-functionalized ILs and bifunctionalized ILs have been developed for CO2 catalytic conversion, for instance, carboxylative cyclization of nucleophiles e.g., propargylic alcohols, amines, 2-aminobenzonitriles and o-aminobenzenethiol, and formylation of amines or 2-aminothiophenols with hydrosilanes to afford various value-added chemicals e.g., cyclic carbamates, unsymmetrical organic carbonates, α-hydroxyl ketones, and benzimidazolones. In a word, IL could provide a powerful tool for efficient CO2 utilization

Forecasting the Short-Term Passenger Flow on High-Speed Railway with Neural Networks

Short-term passenger flow forecasting is an important component of transportation systems. The forecasting result can be applied to support transportation system operation and management such as operation planning and revenue management. In this paper, a divide-and-conquer method based on neural network and origin-destination (OD) matrix estimation is developed to forecast the short-term passenger flow in high-speed railway system. There are three steps in the forecasting method. Firstly, the numbers of passengers who arrive at each station or depart from each station are obtained from historical passenger flow data, which are OD matrices in this paper. Secondly, short-term passenger flow forecasting of the numbers of passengers who arrive at each station or depart from each station based on neural network is realized. At last, the OD matrices in short-term time are obtained with an OD matrix estimation method. The experimental results indicate that the proposed divide-and-conquer method performs well in forecasting the short-term passenger flow on high-speed railway