Effects of integrin-targeted photodynamic therapy on pancreatic carcinoma cell

AIM:To investigate the effects of photodynamic therapy with quantum dots-arginine-glycine-aspartic acid(RGD)probe as photosensitizer on the proliferation and apoptosis of pancreatic carcinoma cells.METHODS:Construction of quantum dots-RGD probe as photosensitizer for integrin-targeted photodynamic therapy was accomplished.After cells were treated with photodynamic therapy(PDT),the proliferation of SW1990 cells were measured by methyl thiazolyl tetrazolium assay.Morphologic changes,cell cycle retardance and apoptosis were observed under fluoroscope and flow cytometry.The expression of myeloid cell leukemia-1(Mcl-1),protein kinase B(Akt)and tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)mRNA were detected by reverse transcriptionpolymerase chain reaction.The amount of reactive oxygen species were also evaluated by fluorescence probe.RESULTS:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibited cell proliferation(P<0.01).Apoptotic cells and morphologic changes could be found under optical microscope.The FCM revealed PDT group had more significant cell apoptosis rate compared to control cells(F=130.617,P<0.01)and cell cycle G0/G1and S retardance(P<0.05)compared to control cells.The expression of Mcl-1 and Akt mRNA were down-regulated,while expression of TRAIL mRNA was up-regulated after cells treated with PDT.PDT group had more significant number of cells producing reactive oxygen species compared to control cells(F=3262.559,P<0.01).CONCLUSION:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibits cell proliferation and increases apoptosis in SW1990 cells.

Methylation of PTCH1a gene in a subset of gastric cancers

AIM： To establish if PTCHla transcriptional regulation region （TRR） is methylated in gastric cancer and its influence in gastric tumorigenesis.METHODS： The CpG islands in PTCHla TRR were analyzed by Methyl Primer Express v1.0 software. The region from -643 to -355 bp （the transcription initiation site of PTCHla was designated as 0） that contained 19 CpG sites was chosen for bisulfitesequencing PCR （BSP） and methylation-specific PCR （MSP） detection. The gastric cancer cell line AGS was treated with 5-aza-2′-deoxycytidine （5-Aza-dC; 1 μmol/L） for 3 d. Alterations in PTCHla TRR methylation in treated AGS cells was measured through BSP clone sequences, and their PTCH1 expression was measured by quantitative RT-PCR. The cell cycle and apoptosis were observed with flow cytometry through propidium iodide （PI） staining or annexin V/PI double staining. The prevalence of PTCHla TRR methylation was investigated in 170 gastric cancer tissue samples and the adjacent normal tissues by MSP. The correlation of PTCH1a TRR methylation with PTCH1 expression or with patients＇ clinical features was analyzed.RESULTS： Methylation of PTCHla TRR was observed in AGS ceils and a subset of gastric cancer tissues （32%, 55/170）, while no methylation amplification products were observed in any normal tissues by MSP. The methylation of PTCH1α TRR was correlated negatively with PTCH1 expression （Spearman＇s r = -0.380, P = 0.000）. However, methylation of PTCHla TRR was not related to the gastric cancer patients＇ clinical features, such as sex, age of onset, clinical stage, lymph node metastasis or histological grade. The methylation of PTCHla TRR in AGS cells was almost converted to non-methylation after 5-Aza-dC treatment, which increased PTCH1 expression （5.3 ± 2.5 times; n = 3） and apoptosis rate （3.0 ± 0.26 times; P 〈 0.05; n = 3）.CONCLUSION： Methylation of PTCH1α TRR is present in a subset of gastric cancers and correlated negatively with PTCH1 expression. This may be an early event in gastric tumorigenesis and a new treatment target.

The building of a dream:The inaugural editorial

For too long,China,the sleeping giant,was left unnoticed by the rest of the sport world.The giant,however,awoke from the slumber and has risen to the top of the world of sports since the 1980s.Throughout the monumental Beijing 2008 Summer Olympic Games,the world took notice at the outstanding performances of the Chinese athletes who took 51 gold medals, surpassing the superpowers USA and Russia,and made China the country winning the most gold medals.China’s strong presence at the Olympic Games,as commented by

Effect of Allocryptopine on Late sodium current of atrial myocytes in spontaneously hypertensive rats

Objective To explore the effect of allocryptopine （All） on the Late sodium current （INa,Late） of atrial myocytes in spontaneously hyper- tensive rats （SHR）. Method The enzyme digestion method was used to separate single atrial myocytes from SHR and Wistar-Kyoto rat （WKY） rats. INa,Late was record by patch-clamp technique and the effect of All on the current was evaluated. Results Comparing with WKY cells, markedly increasing of INa,Late current in SHR myocytes was found from 0.24 ± 0.02 pA/pF of WKY cells to 1.73± 0.04 pA/pF of SHR cells （P 〈 0.01, n = 15）. After treament with 30 μmol/L All; the current densities was reduced to 0.92 ± 0.03 pA/pF. The ratio of INa,Late/INa,peak of WKY and SHR were 0.09% ± 0.01% and 0.71% ± 0.02%, INa, Late/INa,peak of SHR was reduced to 0.37% ± 0.02% by 30 μmol/L All （P 〈 0.01, n = 15）. We also determined the effect of All on the gating mechanism of the INa,Late in the SHR cells. It was found that All decreased the INa,Late by alleviating the inactivation of the channels and increasing the window current of sodium channel. Conclusion Increased INa,Late in SHR atrial myocytes and the prolonged APD were inhibited by All coming from Chinese herb medicine.

Gut,metabolism and nutritional Support for COVID-19:Experiences from China

There is little research that focuses on the relationship between the gut,metabolism,nutritional support and COVID-19.As a group of Chinese physicians,nutritionists and scientists working on the frontline treating COVID-19 patients,we aim to integrate our experiences and the current clinical evidence to address this pressing issue in this article.Based on our clinical observations and available evidence,we recommend the following practice.Firstly,the Nutritional Risk Screening 2002 tool should be used routinely and periodically;for patients with a score≥3,oral nutritional supplements should be given immediately.Secondly,for patients receiving the antiviral agents lopinavir/ritonavir,gastrointestinal side effects should be monitored for and timely intervention provided.Thirdly,for feeding,the enteral route should be the first choice.In patients undergoing mechanical ventilation,establishing a jejunal route as early as possible can guarantee the feeding target being achieved if gastric dilatation occurs.Fourthly,we suggest a permissive underfeeding strategy for severe/critical patients admitted to the intensive care unit during the first week of admission,with the energy target no more than 20 kcal/kg/day(for those on mechanical ventilation,this target may be lowered to 10–15 kcal/kg/day)and the protein target around 1.0–1.2 g/kg/day.If the inflammatory condition is significantly alleviated,the energy target may be gradually increased to 25–30 kcal/kg/day and the protein target to 1.2–1.5 g/kg/day.Fifthly,supplemental parenteral nutrition should be used with caution.Lastly,omega-3 fatty acids may be used as immunoregulators,intravenous administration of omega-3 fatty emulsion(10 g/day)at an early stage may help to reduce the inflammatory reaction.

基于动态磁网络和Simulink的高速铁路牵引传动系统联合仿真（英文）

目的:提出基于动态磁网络和Simulink的高速铁路牵引传动系统的动态参数模型,提高高速铁路牵引传动系统仿真分析的准确度。方法:将动态磁网络计算得出的动态参数Ld,Lq等以查表的形式嵌入Simulink模型,有效地实现动态参数。结论:该动态参数模型能在不显著增加仿真运算量和仿真时间的条件下有效地提高计算的准确度。

A fault tolerant single sided matrix converter for flight control actuation systems

We describe a single sided matrix converter (SSMC) designed for safety critical applications like flight control actuation systems. Dynamic simulations of multi-phase SSMC using Matlab Simulink are carried out to evaluate the fault tolerance capabilities. Investigation into different numbers of phases and power converter topologies under single phase open circuit, single switch open circuit, and single switch short circuit has been executed. The simulation results confirm 5-phase SSMC design as a compromise between fault tolerance and converter size/volume. A 5-phase SSMC prototype was built. Experimental results verify the effectiveness of our design.