ABSTRACT
An open-access microfluidic chip which enabled automatic cell distribution and complex multi-step operations was developed.The microfluidic chip featured a key structure in which a nanoporous membrane was sandwiched by a cell culture chamber array layer and a corresponding media reservoir array layer.The microfluidic approach took advantage of the characteristics of the nanoporous membrane.On one side, this membrane permitted the flow of air but not liquid, thus acting as a flow-stop valve to enable automatic cell distribution.On the other side, it allowed diffusion-based media exchange and thus, mimicked the endothelial layer.In synergy with a liquid transferring platform, the open-access microfluidic system enabled complex multi-step operations involving medium exchange, drug treatment, and cell viability testing.By using this microfluidic protocol, a 10 × 10 tissue arrays was constructed in 90 s, followed by schedule-dependent drug testing.Morphological and immunohistochemical assays results indicated that the resultant tumor tissue was faithful to that in vivo.Drug testing assays showed that the microfluidic tissue array promised multi-step cell assays under biomimetic microenvironment, thus providing an advantageous tool for cell research.
ABSTRACT
Objective:To investigate the impact of different hospitals on reperfusion time in acute ST-segment elevation myocardial infarction (STEMI) patients from regional cooperative chest pain center (CPC).Methods:A total of 364 STEMI patients received percutaneous coronary intervention (PCI) at 18 months before and after CPC establishment were enrolled.Based on hospital levels,the patients were divided into 2 groups:Initial PCI hospital group,n=197 and Initial non-PCI hospital group,n=167.According to hospital visiting time,Initial PCI hospital group was further divided into 2 subgroups as Green channel subgroup,n=91 and CPC subgroup,n=106;Initial non-PCI hospital group was further divided into 2 subgroups as Routine referral subgroup,n=71 and CPC referral subgroup,n=96.Total ischemia time,from onset to first medical contact (S-FMC) time,from S-FMC to balloon dilatation (FMC2B) time,from hospital visit to balloon dilatation (D2B) time were compared among relevant patients;the impact factors for total ischemia time were studied by multivariate regression analysis.Results:Compared with Routine referral subgroup,the following parameters were shortened in CPC referral subgroup:total ischemia time 325 (236,1185) min vs 367 (214,1340) min,P＜0.05;FMC2B time 115 (82,227) min vs 149 (94,483) min,P＜0.05;D2B time 69 (35,195) min vs 105 (55,260) min,P＜0.05.Compared with CPC referral subgroup,the following parameters were further shortened in Initial PCI hospital group:total ischemia time 283 (168,873) min vs 325 (236,1185) min,P＜0.05;FMC2B time 78 (45,265) min vs 115 (82,227) min,P＜0.05.Multivariate linear regression analysis presented that high school or above education (β=-0.117,P=0.047),arrived PCI hospital within 60 min of onset (β=-0.243,P=0.000)and using initial PCI hospital (β=-0.175,P=0.000) were the independent impact factors for total ischemia time in STEMI patients.Conclusion:Regional cooperative CPC may shorten FMC2B time by patients' referral;visiting PCI hospital within 60 min of onset was the best way to reduce total isehemia time in STEMI patients.
ABSTRACT
Objective:To investigate the impact of different hospitals on reperfusion time in acute ST-segment elevation myocardial infarction (STEMI) patients from regional cooperative chest pain center (CPC).Methods:A total of 364 STEMI patients received percutaneous coronary intervention (PCI) at 18 months before and after CPC establishment were enrolled.Based on hospital levels,the patients were divided into 2 groups:Initial PCI hospital group,n=197 and Initial non-PCI hospital group,n=167.According to hospital visiting time,Initial PCI hospital group was further divided into 2 subgroups as Green channel subgroup,n=91 and CPC subgroup,n=106;Initial non-PCI hospital group was further divided into 2 subgroups as Routine referral subgroup,n=71 and CPC referral subgroup,n=96.Total ischemia time,from onset to first medical contact (S-FMC) time,from S-FMC to balloon dilatation (FMC2B) time,from hospital visit to balloon dilatation (D2B) time were compared among relevant patients;the impact factors for total ischemia time were studied by multivariate regression analysis.Results:Compared with Routine referral subgroup,the following parameters were shortened in CPC referral subgroup:total ischemia time 325 (236,1185) min vs 367 (214,1340) min,P＜0.05;FMC2B time 115 (82,227) min vs 149 (94,483) min,P＜0.05;D2B time 69 (35,195) min vs 105 (55,260) min,P＜0.05.Compared with CPC referral subgroup,the following parameters were further shortened in Initial PCI hospital group:total ischemia time 283 (168,873) min vs 325 (236,1185) min,P＜0.05;FMC2B time 78 (45,265) min vs 115 (82,227) min,P＜0.05.Multivariate linear regression analysis presented that high school or above education (β=-0.117,P=0.047),arrived PCI hospital within 60 min of onset (β=-0.243,P=0.000)and using initial PCI hospital (β=-0.175,P=0.000) were the independent impact factors for total ischemia time in STEMI patients.Conclusion:Regional cooperative CPC may shorten FMC2B time by patients' referral;visiting PCI hospital within 60 min of onset was the best way to reduce total isehemia time in STEMI patients.
ABSTRACT
BACKGROUND: Because of complicated physiological environment and difficulty to control experimental conditions, it is difficult to get satisfactory results from in vivo studies of cell mechanics.OBJECTIVE: To study the action and mechanism of p38MAPK signaling pathways on myoblast apoptosis based on successful construction of in vitro mechanical stimulation models.METHODS: The C2C12 cells cultured in vitro were divided into control group and SB203580 treatment group. Cyclic tensile stress was applied on the C2C12 myoblast cells for 0, 6, 12 and 24 hours in each group. The Flexcell Strain Unit-5000T was used to expose C2C12 myoblast cell to an equiaxial cyclic of 15% magnitude and a frequency of 10 cycles/min, each cycle including the 3 s stretch and 3 s relaxation. Hoechst 33258 fluorescent staining and optical microscope were used to detect cell apoptosis. RT-PCR, flow cytometric analysis were used to observe the apoptosis of C2C12 myoblast cells and Western blotting were used to detect the activity of p38MAPK and p-p38MAPK. RESULTS AND CONCLUSION: The optical microscope tested the change in the morphology. Hoechst 33258 staining showed that after treatment with cyclic stress, the cell took the typical appearance of apoptosis with chromatin condensation and apoptotic bodies. RT-PCR and flow cytometry showed that with the extension of time the rate of the apoptosis of C2C12 myoblast cell increased. And cells imposed SB203580 before imposing cyclical tensile stress, the results showed that the apoptosis was markedly affected, and the p-p38MAPK expression declined apparently. These findings demonstrate that p38MAPK signaling pathways in stress mediated into C2C12 myoblast cell apoptosis plays an important role.
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A pair of degenerate primers were designed based on NBS (nucleotide binding site, NBS) domain of resistance(R) gene and used to perform PCR with cDNA from the translocation line 6VS/6AL of Triticum aestivum-Haynaldia villosa. A clone (N7) characterized with NBS was obtained by sequencing analysis. Two specific primers were designed from the N7 sequence and used to screen a genomic TAC (transformation-competent artificial chromosome, TAC) library of 6VS/6AL consisting of ca. 2 x 10(6) clones. The library was stored as clone pools in twenty-two 96-well plates, each well containing approximately 1000 TAC clones. TAC plasmids were prepared from all the 2112 pools. Using a pooled PCR screening procedure, a positive TAC clone having a 40 kb insert was obtained. The positive clone was confirmed by Southern hybridization with the NBS fragment as a probe. The results indicate that the pooled PCR method is effective for screening of genomic libraries having large number of clones.