A chronocoulometric aptasensor based on gold nanoparticles as a signal amplification strategy for detection of thrombin

A sensitive chronocoulometric aptasensor for the detection of thrombin has been developed based on gold nanoparticle amplification. The functional gold nanoparticles, loaded with link DNA (LDNA) and report DNA (RDNA), were immobilized on an electrode by thrombin aptamers performing as a recognition element and capture probe. LDNA was complementary to the thrombin aptamers and RDNA was noncomplementary, but could combine with [Ru(NH₃)₆]³⁺ (RuHex) cations. Electrochemical signals obtained by RuHex that bound quantitatively to the negatively charged phosphate backbone of DNA via electrostatic interactions were measured by chronocoulometry. In the presence of thrombin, the combination of thrombin and thrombin aptamers and the release of the functional gold nanoparticles could induce a significant decrease in chronocoulometric signal. The incorporation of gold nanoparticles in the chronocoulometric aptasensor significantly enhanced the sensitivity. The performance of the aptasensor was further increased by the optimization of the surface density of aptamers. Under optimum conditions, the chronocoulometric aptasensor exhibited a wide linear response range of 0.1–18.5 nM with a detection limit of 30 pM. The results demonstrated that this nanoparticle-based amplification strategy offers a simple and effective approach to detect thrombin.     

The rs2233678 Polymorphism in PIN1 Promoter Region Reduced Cancer Risk: A Meta-Analysis

Background

Published evidence suggests that the rs2233678 (−842 G>C) polymorphism in the PIN1 (peptidyl-prolyl cis/trans somerase NIMA-interacting 1) promoter region may be associated with cancer risk; however, the conclusion is still inconclusive.

Methods

We conducted a meta-analysis to determine whether −842 G>C polymorphism was associated with cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Genotype distribution data and adjusted ORs were collected to calculate the pooled ORs. Meta-regression was conducted to detect the source of heterogeneity. Publication bias was evaluated by Egger’s test and Begg’s test.

Results

A total of 11 eligible studies, including 9280 participants, were identified and analyzed. Overall, we found that carriers of the −842 C allele were associated with significantly decreased cancer risk (C vs. G, OR = 0.750, 95% CI: 0.639–0.880, P_{heterogeneity} = 0.014, estimated by genotype distribution data; CC+GC vs. GG, OR = 0.668, 95% CI: 0.594–0.751, P_{heterogeneity} = 0.638, estimated by adjusted ORs). No evidence of publication bias was observed. Meta-regression revealed that ethnicities (p = 0.021) and sample size (p = 0.02) but not sources of control (p = 0.069) were the source of heterogeneity.

Conclusion

These results suggest that the PIN1 rs2233678 (−842 G>C) polymorphism significantly reduces cancer risk.     

Fatty Acid Binding Proteins FABP9 and FABP10 Participate in Antibacterial Responses in Chinese Mitten Crab,Eriocheir sinensis

Invertebrates rely solely on the innate immune system for defense against pathogens and other stimuli. Fatty acid binding proteins (FABP), members of the lipid binding proteins superfamily, play a crucial role in fatty acid transport and lipid metabolism and are also involved in gene expression induced by fatty acids. In the vertebrate immune system, FABP is involved in inflammation regulated by fatty acids through its interaction with peroxidase proliferator activate receptors (PPARs). However, the immune functions of FABP in invertebrates are not well characterized. For this reason, we investigated the immune functionality of two fatty acid binding proteins, Es-FABP9 and Es-FABP10, following lipopolysaccharide (LPS) challenge in the Chinese mitten crab (Eriocheir sinensis). An obvious variation in the expression of Es-FABP9 and Es-FABP10 mRNA in E. sinensis was observed in hepatopancreas, gills, and hemocytes post-LPS challenge. Recombinant proteins rEs-FABP9 and rEs-FABP10 exhibited distinct bacterial binding activity and bacterial agglutination activity against Escherichia coli and Staphylococcus aureus. Furthermore, bacterial growth inhibition assays demonstrated that rEs-FABP9 responds positively to the growth inhibition of Vibrio parahaemolyticuss and S. aureus, while rEs-FABP10 responds positively to the growth inhibition of Aeromonas hydrophila and Bacillus subtilis. Coating of agarose beads with recombinant rEs-FABP9 and rEs-FABP10 dramatically enhanced encapsulation of the beads by crab hemocytes in vitro. In conclusion, the data presented here demonstrate the participation of these two lipid metabolism-related proteins in the innate immune system of E. sinensis.     

Low‐Temperature Solution‐Based Phosphorization Reaction Route to Sn4P3/Reduced Graphene Oxide Nanohybrids as Anodes for Sodium Ion Batteries

Different from previously reported mechanical alloying route to synthesize Sn _x P₃, novel Sn₄P₃/reduced graphene oxide (RGO) hybrids are synthesized for the first time through an in situ low‐temperature solution‐based phosphorization reaction route from Sn/RGO. Sn₄P₃ nanoparticles combining with advantages of high conductivity of Sn and high capacity of P are homogenously loaded on the RGO nanosheets, interconnecting to form 3D mesoporous architecture nanostructures. The Sn₄P₃/RGO hybrid architecture materials exhibit significantly improved electrochemical performance of high reversible capacity, high‐rate capability, and excellent cycling performance as sodium ion batteries (SIBs) anode materials, showing an excellent reversible capacity of 656 mA h g^?1 at a current density of 100 mA g^?1 over 100 cycles, demonstrating a greatly enhanced rate capability of a reversible capacity of 391 mA h g^?1 even at a high current density of 2.0 A g^?1. Moreover, Sn₄P₃/RGO SIBs anodes exhibit a superior long cycling life, delivering a high capacity of 362 mA h g^?1 after 1500 cycles at a high current density of 1.0 A g^?1. The outstanding cycling performance and rate capability of these porous hierarchical Sn₄P₃/RGO hybrid anodes can be attributed to the advantage of porous structure, and the synergistic effect between Sn₄P₃ nanoparticles and RGO nanosheets.     

Effect of Stem Cell Therapy on Bone Mineral Density: A Meta-Analysis of Preclinical Studies in Animal Models of Osteoporosis

Background

Preclinical studies of the therapeutic role of stem cell based therapy in animal models of osteoporosis have largely yielded inconsistent results. We performed a meta-analysis to provide an overview of the currently available evidence.

Methods

Pubmed, Embase and Cochrane Library databases were systematically searched for relevant controlled studies. A random-effect model was used for pooled analysis of the effect of stem cell based therapy on bone mineral density (BMD). Stratified analyses were performed to explore the effect of study characteristics on the outcomes.

Results

Pooled results from 12 preclinical studies (110 animals in stem cell treatment groups, and 106 animals in control groups) indicated that stem cell based treatment was associated with significantly improved BMD (standardized mean difference [SMD] = 1.29, 95% Confidence Interval [CI]: 0.84–1.74, P < 0.001) with moderate heterogeneity (Cochrane’s Q test: P = 0.02, I² = 45%) among the constituent studies. Implantation of bone marrow cells, bone marrow mesenchymal stem cells, adipose-derived stem cells, and human umbilical cord blood-derived CD34+ cells, were all associated with improved BMD as compared to that in the controls (P < 0.05 for all); the only exception being the use of embryonic stem cell transplantation (P > 0.05). Egger’s test detected potential publication bias (P = 0.055); however, ‘trim and fill’ analysis yielded similar results after statistically incorporating the hypothetical studies in the analysis (SMD = 1.24, 95% CI: 0.32–2.16, P < 0.001).

Conclusions

Stem cell transplantation may improve BMD in animal models of osteoporosis. Our meta-analysis indicates a potential therapeutic role of stem cell based therapy for osteoporosis, and serves to augment the rationale for clinical studies.     

Sensitive and selective turn‐on fluorescence method for cetyltrimethylammonium bromide determination based on acridine orange–polystyrene sulfonate complex

This work proposed a rapid and novel fluorescence‐sensing system using a complex of acridine orange (AO) and polystyrene sulfonate (PSS) to sensitively recognize and monitor cetyltrimethylammonium bromide (CTAB) in an aqueous medium. AO can interact with PSS and a complex is formed via electrostatic attraction and hydrophobic interaction. The fluorescence of AO is greatly quenched after the introduction of PSS. Upon its subsequent addition, CTAB can interact and form a complex with PSS because the electrostatic attraction between CTAB and PSS is much stronger than that between AO and PSS, which results in significant fluorescence recovery. Interestingly, the proposed method can be applied for the discrimination and detection of surfactants with different hydrocarbon chain lengths due to their different binding affinity toward PSS. The detection limit for CTAB is as low as 0.2 µg/mL and the linear range is from 0.5 to 3.5 µg/mL. Moreover, we applied the sensor to the successful detection of CTAB in water samples. Copyright © 2015 John Wiley & Sons, Ltd.     

快速现场细胞学评价在经支气管针吸活检术诊断肺部良恶性疾病的临床应用

目的:超声引导下的经支气管针吸活检术(Endobronchial ultrasound guided transbronchial needle aspiration, EBUS-TBNA)是临床上广泛开展的经支气管的微创介入技术,在EBUS-TBNA过程中,快速现场细胞学评价(Cytologicalrapidon-siteevaluation,C-ROSE)是切实可行的临床辅助技术。本研究探讨C-ROSE在EBUS-TBNA对肺部疾病诊断的细胞学特点及诊断价值。方法:对41例经胸部计算机断层扫描(Computed tomography,CT)发现存在纵隔和(或)肺门病灶(包括肿大的淋巴结/肿块)而行EBUS-TBNA及C-ROSE患者进行回顾性分析。结果:C-ROSE镜下的细胞学具有明显特点,对肺部良恶性疾病的穿刺成功率无差异,诊断率分别为90.48%和66.67%(P0.05),且C-ROSE可完全排除恶性疾病的诊断,二组并发症发生率分别为9.52%和6.67%(P0.05)。结论:C-ROSE在EBUS-TBNA中对肺部良恶性病变均具有诊断价值,可以提高穿刺成功率及诊断率、减少并发症,值得在临床医疗介入中心推广。