Immobilization of insulin-like growth factor-1 onto thermosensitive hydrogels to enhance cardiac progenitor cell survival and differentiation under ischemic conditions

Stem cell therapy is a promising approach to treat myocardial infarction. However, direct delivery of stem cells into hearts experiences poor cell engraftment and differentiation, due to ischemic conditions (low nutrient and oxygen) in the infarct hearts. Development of suitable cell carriers capable of supporting cell survival and differentiation under these harsh conditions is critical for improving the efficacy of current stem cell therapy. In this work, we created a family of novel cell carriers based on thermosensitive hydrogels and insulin-like growth factor 1 (IGF-1), and investigated if these cell carriers can improve cell survival and differentiation under ischemic conditions. The thermosensitive hydrogels were synthesized from N-isopropylacrylamide, acrylic acid, acrylic acid N-hydroxysuccinicimide ester, and 2-hydroxyethyl methacrylate-oligo(hydroxybutyrate). The hydrogel solutions can be readily injected through 26G needles, and can quickly solidify at 37 °C to form highly flexible hydrogels. IGF-1 was immobilized into the hydrogels in order to support long-term cell survival and differentiation. Different amount of IGF-1 was immobilized by using hydrogels with different content of N-hydroxysuccinicimide ester groups. Cardiosphere derived cells were encapsulated in the hydrogels and cultured under ischemic conditions. The results demonstrated that a significant improvement of cell survival and differentiation was achieved after IGF-1 immobilization. These IGF-1 immobilized hydrogels have the potential to improve cell survival and differentiation in infarct hearts.     

Silicon nanowires as field-effect transducers for biosensor development: A review

The unique electronic properties and miniaturized dimensions of silicon nanowires (SiNWs) are attractive for label-free, real-time and sensitive detection of biomolecules. Sensors based on SiNWs operate as field effect transistors (FETs) and can be fabricated either by top–down or bottom–up approaches. Advances in fabrication methods have allowed for the control of physicochemical and electronic properties of SiNWs, providing opportunity for interfacing of SiNW-FET probes with intracellular environments. The Debye screening length is an important consideration that determines the performance and detection limits of SiNW-FET sensors, especially at physiologically relevant conditions of ionic strength (>100 mM). In this review, we discuss the construction and application of SiNW-FET sensors for detection of ions, nucleic acids and protein markers. Advantages and disadvantages of the top–down and bottom–up approaches for synthesis of SiNWs are discussed. An overview of various methods for surface functionalization of SiNWs for immobilization of selective chemistry is provided in the context of impact on the analytical performance of SiNW-FET sensors. In addition to in vitro examples, an overview of the progress of use of SiNW-FET sensors for ex vivo studies is also presented. This review concludes with a discussion of the future prospects of SiNW-FET sensors.     

健身气功·八段锦对老年人心肺功能影响

本研究观察经6个月健身气功·八段锦锻炼后对老年人心肺功能的影响．随机选取大连市沙河口区40名健康、无锻炼习惯的退休职工为实验对象,并随机分为实验组和对照组．验组在教师的指导下进行6个月、每天一次的健身气功“八段锦”锻炼．结果显示,与对照组比较,实验组肺活量及肺活量指数显著升高（P〈0．01）;LPET／LVET及平均动脉压明显下降（P〈0．05及P〈0．01）;CO、SV及台阶实验指数显著升高（P〈0．05及P〈0．01）．结果显示,6个月健身气功“八段锦”锻炼对老年人心肺功能的改善具有良好的促进作用．     

心磁和心电信号的混沌时间序列分析

计算了一组心磁和心电检测信号的关联维数和最大李亚普诺夫(Lyapunov)指数.心磁和心电信号的关联维数分别在2.28±0.27和1.12±0.13范围内,最大Lyapunov指数分别在0.68±0.12和0.32±0.04范围内.对其它4组数据中心测点的计算结果也说明心磁和心电信号具有混沌特性.此外,结果显示心磁边缘测点的混沌吸引子与中心部分有明显差别,可用于分析信号的有效检测范围.     

心脏瓣膜置换术后妊娠的处理（附8例）

目的：探讨心脏瓣膜置换术后妊娠的临床情况及处理。方法：分析经治的8例心脏瓣膜置换术后妊娠患者的临床表现、处理及结局。结果：8例心脏瓣膜置换术后妊娠患者经过合理抗凝,适时剖宫产分娩,母婴平安出院。结论：对心脏瓣膜置换术后妊娠患者应予重视,合理抗凝、密切监护,以保证患者在孕期和分娩期的安全。     

Cytotoxicity,apoptosis, interaction with DNA,cellular uptake,and cell cycle arrest of ruthenium(II) polypyridyl complexes containing 4,4′-dimethyl-2,2′-bipyridine as ancillary ligand

Two new ruthenium(II) polypyridyl complexes, [Ru(dmb)₂(DNPIP)](ClO₄)₂ (1) (DNPIP?=?2-(2,4-dinitrophenyl)imidazo[4,5-f][1,10]phenanthroline, dmb?=?4,4′-dimethyl-2,2′-bipyridine) and [Ru(dmb)₂(DAPIP)](ClO₄)₂ (2) (DAPIP?=?2-(2,4-diaminophenyl)imidazo[4,5f][1,10]phenanthroline), were synthesized and characterized. The DNA-binding behaviors of these complexes have been studied by UV-Vis absorption titration, viscosity measurements, and photocleavage. The DNA-binding constants are 7.39 (±0.16)?×?10⁴ (s?=?2.68) and 2.73 (±0.16)?×?10^4?(mol?L^?1)^?1 (s?=?0.64) for 1 and 2, respectively. Their evaluation as cytotoxic agents on different cancer cell lines was investigated with IC₅₀ values of 59.5, 51.3, and 70.3?µmol?L^?1 for 1, >100, 87.9, and 77.9?µmol?L^?1 for 2 against BEL-7402, HepG-2, and MCF-7 cells, respectively. Complex 1 is more active than 2 against selected cancer cell lines. The apoptosis induced by these complexes was studied. Cellular uptake showed that these complexes could enter into the cytoplasm and accumulate in the nuclei. The cell cycle arrest and antioxidant activity against hydroxyl radicals were also investigated.     

Synthesis,characterization, photocleavage,cytotoxicity in vitro,apoptosis, and cell cycle arrest of ruthenium(II) complexes

Two new ruthenium(II) complexes, [Ru(dmp)₂(BHIP)]²⁺ (1) and [Ru(dmb)₂(BHIP)]²⁺ (2), were synthesized and characterized by elemental analysis, ESI-MS, and ¹H NMR. DNA-binding constants of these complexes with calf-thymus DNA (ct-DNA) were determined to be 2.09 (±0.18)?×?10⁴ (mol?L^?1)^?1 (s?=?2.58) and 1.48 (±0.17)?×?10⁵ (mol?L^?1)^?1 (s?=?1.57), respectively. Viscosity measurements show that 1 and 2 interact with ct-DNA by intercalation. Upon irradiation at 365?nm, 1 and 2 induce cleavage of pBR322 DNA. The cytotoxicity of these complexes was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptosis induced by the complexes was studied by flow cytometry. The results of the cell cycle arrest show that 2 can inhibit the proliferation of BEL-7402 cells in the G0/G1 phase.     

Novel carbon-bridged citrinin dimers from a volcano ash-derived fungus Penicillium citrinum and their cytotoxic and cell cycle arrest activities

Three novel carbon-bridged citrinin dimers, dicitrinones A-C (1-3), were isolated from a volcano ash-derived fungus Penicillium citrinum. Their structures were elucidated by spectroscopic methods. Dicitrinone A (1) and B (2) are two atropisomeric mixtures, which were verified by both NMR and quantum chemical calculations. Their cytotoxicity against four tumor cell lines (HL-60, MOLT-4, A-549, and BEL-7402) was evaluated by SRB and MTT methods. Dicitrinone B (2) arrested the HL-60 cell cycle at the G2/M phase, which was analyzed using flow cytometry.     

Strip saturation model solution for a piezoelectric plate by linearly varying electrical loads under mode-I conditions

A strip saturation model solution is obtained for a poled cracked piezoelectric ceramic plate. The plate is cut along a straight finite hair line crack whose rims are perpendicular to the poling axis of the plate. A mechanical load and an electric field applied open the rims of the crack and, as a result, saturation zones develop ahead of its tips. To arrest the crack from further opening, a linearly varying saturation limit normal electrical displacement is prescribed on rims of the saturation zones. The technique of complex variables is used to obtain the solution to the problem. A case study is presented for PZT-4, PZT-5, and PZT-7 ceramics. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 45, No. 1, pp. 85–92, January–February, 2009.     

Computational-Based Discovery of the Anti-Cancer Activities of Pyrrole-Based Compounds Targeting the Colchicine-Binding Site of Tubulin

Despite the tubulin-binding agents (TBAs) that are widely used in the clinic for cancer therapy, tumor resistance to TBAs (both inherited and acquired) significantly impairs their effectiveness, thereby decreasing overall survival (OS) and progression-free survival (PFS) rates, especially for the patients with metastatic, recurrent, and unresectable forms of the disease. Therefore, the development of novel effective drugs interfering with the microtubules’ dynamic state remains a big challenge in current oncology. We report here about the novel ethyl 2-amino-1-(furan-2-carboxamido)-5-(2-aryl/tert-butyl-2-oxoethylidene)-4-oxo-4,5-dihydro-1H-pyrrole-3-carboxylates (EAPCs) exhibiting potent anti-cancer activities against the breast and lung cancer cell lines in vitro. This was due to their ability to inhibit tubulin polymerization and induce cell cycle arrest in M-phase. As an outcome, the EAPC-treated cancer cells exhibited a significant increase in apoptosis, which was evidenced by the expression of cleaved forms of PARP, caspase-3, and increased numbers of Annexin-V-positive cells. By using the in silico molecular modeling methods (e.g., induced-fit docking, binding metadynamics, and unbiased molecular dynamics), we found that EAPC-67 and -70 preferentially bind to the colchicine-binding site of tubulin. Lastly, we have shown that the EAPCs indicated above and colchicine utilizes a similar molecular mechanism to inhibit tubulin polymerization via targeting the T7 loop in the β-chain of tubulin, thereby preventing the conformational changes in the tubulin dimers required for their polymerization. Collectively, we identified the novel and potent TBAs that bind to the colchicine-binding site and disrupt the microtubule network. As a result of these events, the compounds induced a robust cell cycle arrest in M-phase and exhibited potent pro-apoptotic activities against the epithelial cancer cell lines in vitro.