Modified capillary electrophoresis based measurement of the binding between DNA aptamers and an unknown concentration target.

The recognition of targets such as biomacromolecules, viruses and cells by their aptamers is crucial in aptamer-based biosensor platforms and research into protein function. However, it is difficult to evaluate the binding constant of aptamers and their targets that are hard to purify and quantify, especially when the targets are undefined. Therefore, we aimed to develop a modified capillary electrophoresis based method to determine the dissociation constant of aptamers whose targets are hard to quantify. A protein target, human thrombin, and one of its aptamers were used to validate our modified method. We demonstrated that the result calculated by our method, only depending on the aptamer's concentrations, was consistent with the classical method, which depended on the concentrations of both the aptamers and the targets. Furthermore, a series of DNA aptamers binding with avian influenza virus H9N2 were confirmed by a four-round selection of capillary electrophoresis-systematic evolution of ligands by exponential enrichment, and we identified the binding constant of these aptamers by directly using the whole virus as the target with the modified method. In conclusion, our modified method was validated to study the interaction between the aptamer and its target, and it may also advance the evaluation of other receptor-ligand interactions.

[Professor SHAO Jing-ming's clinical experience of fire needling for surgical diseases].

Professor SHAO Jing-ming's clinical experience of fire needling for bone-joint tuberculosis, tuberculous cervical lymphadenitis, ganglion cyst and thyrophyma is summarized. Professor SHAO used fire needling to treat bone-joint tuberculosis. The acupoints included ashi points and nearby acupoints, particularly local opposite acupoints (Neixiyan [EX-LE 4] and Dubi [ST 35], Yinlingquan [SP 9] and Yanglingquan [GB 34], Xuehai [SP 10] and Liangqiu [ST 34]), and for the patients with severe yin-cold syndrome, Yanghe decoction was additionally used. For tuberculous cervical lymphadenitis, fire needling was used at different stages. In the early stage, the nucleus was punctured with fire needling; in the middle stage, the pustule was punctured with fire needling combined with cupping; in the late stage, the fire needling was inserted into the fistula or sinus tract, and the surrounding granulation tissue was treated with horizontal penetrating needling. For ganglion cyst, fire needling combined with centro-square needling was applied. For thyrophyma, the surrounding needling with filiform was used; for simple thyroid mass and thyroid nodule, the surrounding needling with fire needling was used.

[Effect of acupuncture preconditioning combined with PI3K blocker LY294002 on airway inflammation in asthmatic rats].

OBJECTIVE: To observe the effect of acupuncture preconditioning combined with PI3K blocker LY294002 on the expression of PI3K and Akt proteins and genes in the lung tissue and the contents of serum IL-12 and IL-13 in asthmatic rats, so as to explore its preprotective mechanism underlying improving asthma. METHODS: Sixty male Wistar rats were randomly divided into blank control, model, acupuncture pretreatment + blank, acupuncture pretreatment, acupuncture pretreatment + LY294002 and LY294002 groups (n=10 in each group). The asthma model was established by intraperitoneal injection of mixture solution of OVA and Al(OH)3 and followed inhalation of 1%OVA for 30 min, once daily for 7 days. Rats of the blocker groups received inhalation of atomized LY294002 solution for 30 min before inhalation of 1% OVA, and acupuncture was applied to "Feishu"(BL13), "Dazhui"(GV14) and "Fengmen"(BL12) for 20 min, once daily for 7 days before modeling. H.E. staining was used to assess histopathological changes of the lung tissue, and ELISA was used to detect the contents of serum IL-12 and IL-13. The immunoactivity of PI3K and Akt and expression of Akt mRNA of the lung tissue were detected by using immunohistochemistry and fluorescence quantitative real-time PCR, separately. RESULTS: Compared with the blank control group, the content of serum IL-12 was significantly decreased (P<0.01), and the content of serum IL-13, the expression levels of PI3K, Akt protein and Akt mRNA were remarkably increased (P<0.01) in the model group. In comparison with the model group, the content of serum IL-12 in the pretreatment, pretreatment + LY294002 and LY294002 groups was significantly increased (P<0.01, P<0.05), while the content of IL-13 and the expression levels of PI3K, Akt protein and Akt mRNA were considerably decreased (P<0.01, P<0.05) in the acupuncture pretreatment, acupuncture pretreatment+LY294002 and LY294002 groups. The therapeutic effect of acupuncture pretreatment+LY294002 was obviously superior to that of simple acupuncture pretreatment and LY294002 (except PI3K and Akt in the LY294002 group) in up-regulating serum IL-12 level, and in down-regulating serum IL-13, and PI3K and Akt protein levels in the lung tissue (P<0.01). H.E. staining showed severe inflammatory factor infiltration in the bronchus and pulmonary interstitium, and obvious bronchial lumen narrowing with increased exudate in rats of the model group, which was relatively milder in rats of the acupuncture pretreatment, acupuncture pretreatment+LY294002 and LY294002 groups. There were no significant diffe-rences between blank control and pretreatment+blank groups in all of the above indicators （P>0.05）. CONCLUSION: Acupuncture preconditioning can inhibit airway inflammation in asthmatic rats, which may be associated with its functions in down-regulating the levels of pulmonary PI3K and Akt and serum IL-13 and up-regulating the content of serum IL-12. Acupuncture preconditioning combined with LY294002 has the best effect.

[Distributions, Sources and Pollution Assessment of Hg in Sediment of Douhe Reservoir in Tangshan City].

Sediment cores from Douhe reservoir in Tangshan City were sampled in August 2013, in order to evaluate the mercury (Hg) pollution degree and its possible sources. Agriculture soils surrounding the Douhe reservoir and sediments from an upstream reservoir (Daheiting) were also collected. Total mercury (THg), methylmercury (MeHg), dissolved mercury in pore water (DHg) and organic matter (OM) in sediment of Douhe reservoir were analyzed, while, only THg in the agriculture soils and upstream reservoir sediments was determined. Finally, the geoaccumulation index method was applied to evaluate the Hg pollution status in soils and reservoir sediments. The results showed that THg content in sediment of Douhe reservoir ranged from 19 to 97 ng·g-1. dw, MeHg (dw) from 0.02 to 1.27 ng·g-1, and the contents of both THg and MeHg were higher in the upper layers than the deeper layers, indicating that Hg in sediments was increasing in recent years by the exogenetic loadings. THg (dw) in soils offshore the Douhe reservoir, which is close to a large coal-fired power plant, averaged at 22 ng·g-1. Among the three sediment cores of Douhe reservoir, the central point had the highest THg, followed by the western site, and the eastern site had the lowest THg. While, THg content (dw) in sediments of Daheiting reservoir was much higher, with a mean of 176 ng·g-1. Combining all the above information, we concluded that Hg in Douhe reservoir was mainly derived from the Daheiting reservoir and the mercury atmospheric deposition from the nearby coal-fired power plant contributed a less content. THg and MeHg in the sediments of Douhe reservoir were positively correlated with OM, indicating that OM in sediments had good ability of adsorbing THg and MeHg, and also played an important role in Hg methylation. The geoaccumulation index (Igeo) showed that the Hg pollution status deceased in this order:central of Daheting, Daba of Daheting, central of Douhe, western of Douhe, eastern of Douhe, soils surrounding Douhe. Central and western sites in Douhe belonged to moderate pollution and the eastern site belonged to slight pollution. While, sediments of Daheiting reservoir, affected by the iron ore mining activities, were in the moderate and strong pollution status.