基于ARM的细胞压力加载装置的研制

细胞骨架是细胞内分子的网络结构,该网络结构能够在一定压力下保持细胞稳定,以保证细胞生存和维持其正常形态。如何为细胞提供体外生存环境,支持细胞研究工作,是该研究的目的。该研究基于细胞力学研究的需要,研制了一种基于ARM的细胞压力加载装置。此装置是模拟细胞体内受力特性建立的一个特殊的压力加载装置,它能够对体外细胞施加特定的压力,构建细胞的体外生存环境。此装置采用ARM开发板控制电磁阀和直线步进电机运行,进而控制培养皿内的气体压力,其控制部分具有较强的实操性,使用操作简易方便。

植物细胞质膜的分布电荷所引起的电场和细胞内压力

根据细胞双电层模型和电学原理,推出了植物细胞膜上电荷产生的细胞内压力的计算公式。利用该公式分析了植物细胞膜上电荷产生的电场力对细胞内压力的影响。得出了细胞的实际内压力和植物体的实际刚度比只考虑机械压力的理论结果要大些,细胞的实际破裂情况比只考虑机械压力时的理论分析结果要容易些三点结论。

内部核糖体进入位点(IRES)调控细胞血清饥饿应激条件下PRDM13的翻译

PRDM13是锌指蛋白转录抑制因子（positive regulatory domain zinc finger protein,PRDM）家族中的一员,其在细胞分化、肿瘤的发生和恶性转化中起着重要的作用。而对于PRDM13基因侧翼序列是否含有内部核糖体进入位点（internal ribosome entry site,IRES）及其功能所知甚少。本研究对PRDM13 5＇端的非翻译区（5＇UTR）进行IRES结构与功能分析,探索其在细胞血清饥饿应激条件下对PRDM13翻译的影响。实验发现,在血清饥饿的条件下,肝癌细胞Bel7402/WT中PRDM13的蛋白质水平增加,但是其mRNA水平基本没有变化。将PRDM13 5＇UTR的序列插入双顺反子的报告载体（pRL-FL）中,并且将构建的载体（pRL-PRDM13-FL）转染进细胞中,结果显示,PRDM13 5＇UTR含有IRES,且发现PRDM13 5＇UTR中的105 nt（53~157）对其IRES的功能至关重要。在帽依赖的翻译（cap-dependent translation）机制被抑制时,IRES这种机制可有效维持PRDM13蛋白合成。本研究提供了在细胞压力条件下调节PRDM13蛋白合成的一种新的解释。

橡胶树乳管膨压的测定技术及其变化规律

橡胶树胶乳是其韧皮部乳管在受到伤害胁迫后排出的液体细胞质。胶乳的再生和排出均与乳管膨压存在一定关联。本文综述了橡胶树乳管膨压的测定技术及其变化规律的研究结果,发现现有的几种乳管膨压测定技术均存在一定缺憾,对乳管膨压变化规律的研究也因测定方法等的限制不够深入、系统,且未与目前生产上普遍使用的乙烯利刺激割胶制度联系起来;并展望了将植物细胞压力探针技术改进后用于橡胶树乳管膨压测定研究的可能性。

Higher CO_2-insufflation pressure inhibits the expression of adhesion molecules and the invasion potential of colon cancer cells

AIM： To investigate the influence of CO2-insufflation pressure on adhesion, invasion and metastatic potential of colon cancer cells based on adhesion molecules expression. METHODS： With an/n vitro artificial pneumoperitoneum model, SW1116 human colon carcinoma cells were exposed to CO2-insufflation in 5 different pressure groups： 6 mmHg, 9 mmHg, 12 mmHg, 15 mmHg and control group, respectively for 1 h. Expression of E-cadherin, ICAM-I, CD44 and E-selectin was meas- ured at 0, 12, 24, 48 and 72 h after CO2-insufflation using flow cytometry. The adhesion and invasion capacity of SW1116 cells before and after exposure to CO2-insufflation was detected by cell adhesion/invasion assay in vitro. Each group of cells was injected intraperitoneally into 16 BALB/C mice. The number of visible abdominal cavity tumor nodules, visceral metas-tases and survival of the mice were recorded in each group. RESULTS： The expression of E-cadherin, ICAM-1, CD44 and E-selectin in SWl116 cells were changed significantly following exposure to CO2 insufflation at different pressures （P 〈 0.05）. The expression of E-cadherin, CD44 and ICAM-1 decreased with increasing CO2-insufflation pressure. The adhesive/ invasive cells also decreased gradually with increasing pressure as determined by the adhesion/invasion assay. In animal experiments, the number of abdominal cavity tumor nodules in the 15 mmHg group was also significantly lower than that in the 6 mmHg group （29.7± 9.91 vs 41.7±14.90, P = 0.046）. However, the survival in each group was not statistically different. CONCLUSION： CO2-insufflation induced a temporary change in the adhesion and invasion capacity of cancer cells in vitro. Higher CO2-insufflation pressure inhibited adhesion, invasion and metastatic potential in vitro and in vivo, which was associated with reduced expression of adhesion molecules.

CRISPR/Cas9方法失活白念珠菌CaMIT1基因及其突变株表型分析

目的构建白念珠菌CaMIT1基因突变株,研究CaMIT1基因在白念珠菌中的功能。方法本文采用CRISPR(Clustered Regularly Interspaced Short Palindromic Repeat)/Cas9这种新的方法构建CaMIT1失活突变株,并通过倍比稀释的方法初步研究CaMIT1的功能。结果成功获得了CaMIT1基因的纯合子失活突变株,表型实验结果显示该基因突变株对钙离子、锂离子、十二烷基磺酸钠、克霉唑、酮康唑、Anidualafungin敏感,对刚果红耐受。结论 CaMIT1与白念珠菌的细胞质膜和细胞壁完整性以及钙离子的稳态相关。

Use of casing and its effect on pressure cells

Although pressure cells have been produced and installed successfully for decades,the accuracy of measured pressure is often inadequate.Due to large differences between the stiffness of pressure cells and the surrounding media,there is a considerable difference between applied pressure and that measured from pressure cells.It is often difficult and expensive to make a pressure cell with stiffness（modulus of elasticity） similar to the surrounding material in which it will be embedded.In order to improve this situation,a casing material with proportional dimensions is recommended as a means to obtain reliable results.In our study,the effect of using casing in the installation of pressure cells is investigated,providing the characteristics of casing.Some practical recommendations are presented to improve the accuracy of the results using casing.

白念珠菌CaSPO75基因的敲除与功能研究

酿酒酵母中ScCsc1是一个最近鉴定的钙离子通透性压力门控阳离子通道蛋白,参与调控胞内离子稳态。ScSpo75是ScCsc1的一个同源蛋白,可能参与孢子壁的装配过程。在白念珠菌中存在一个与ScSPO75同源的基因CaSPO75,其功能尚不清楚,因此采用SAT1-flipper方法敲除CaSPO75的两个等位基因以研究其功能。通过表型筛选,发现该基因的缺失导致白念珠菌对特比萘芬(Teb)、荧光增白剂(CFW)、氯化锰和氯化锌耐受,对酮康唑(KCZ)敏感。因此,CaSPO75基因可能参与白念珠菌耐药性和细胞壁压力反应的调控,以及胞内锰离子和锌离子稳态的调控。

Low central venous pressure reduces blood loss in hepatectomy

AIM： To investigate the effect of low central venous pressure （LCVP） on blood loss during hepatectomy for hepatocellular carcinoma （HCC）. METHODS： By the method of sealed envelope, 50 HCC patients were randomized into LCVP group （n=25） and control group （n=25）. In LCVP group, CVP was maintained at 2-4 mmHg and systolic blood pressure （SBP） above 90 mmHg by manipulation of the patient＇s posture and administration of drugs during hepatectomy, while in control group hepatectomy was performed routinely without lowering CVP. The patients＇ preoperative conditions, volume of blood loss during hepatectomy, volume of blood transfusion, length of hospital stay, changes in hepatic and renal functions were compared between the two groups. RESULTS： There were no significant differences in patients＇ preoperative conditions, maximal tumor dimension, pattern of hepatectomy, duration of vascular occlusion, operation time, weight of resected liver tissues, incidence of post-operative complications, hepatic and renal functions between the two groups. LCVP group had a markedly lower volume of total intraoperative blood loss and blood loss during hepatectomy than the control group, being 903.9 ± 180.8 mL vs 2 329.4 ±2 538.4 （W=495.5, P〈0.01） and 672.4±429.9 mL vs 1 662.6±1 932.1 （W=543.5, P〈0.01）. There were no remarkable differences in the pre-resection and post-resection blood losses between the two groups. The length of hospital stay was significantly shortened in LCVP group as compared with the control group, being 16.3±6.8 d vs 21.5 ± 8.6 d （W= 532.5, P〈0.05）.CONCLUSION： LCVP is easily achievable in technique. Maintenance of CVP ≤4 mmHg can help reduce blood loss during hepatectomy, shorten the length of hospital stay, and has no detrimental effects on hepatic or renal function.

Assessments of Immunological Activity of Achillea Millefolium Methanolic Extract on Albino Male Mice

Achillea millefolium （Asteraceae） is a permanent herb highly recognized in traditional medicine for its anti-oxidant and anti-inflammation properties. However, studies on phytochemical constituents of A. millefolium underlying these properties are scarce. The present work focuses on examining the effect of methanol extract of A. millefolium L. on total and differential blood cells account on albino male mice. The results showed the methanol extract increased the account of lymphocyte, and monocyte cells, and total account as well as this extract showed high decrease in the oxidative stress of MTX after the interfere between the extract and MTX due to increase in the leucocyte cells compared with controls. Concluded from these results that methanol extract of A. millefolium has ability enhancement in leucocyte cells in the blood and it has detoxification effect of MTX.

Science Letters:Cellular growth under hydrostatic pressure using bovine aortic EC-SMC co-cultured ePTFE vascular graft

High blood pressure (hypertension) is implicated in the development of atherosclerosis. Blood vessels are constantly subjected to stretch due to blood pressure and changes in stretch usually instigate adaptive vascular remodeling, including abnormal growth and proliferation of vascular smooth muscle cells (VSMCs) as well as extracellular matrix (ECM). In this experiment, we used bovine aortic endothelial cells and smooth muscle cells (EC-SMC) co-cultured ePTFE vascular grafts subjected to normal atmospheric pressure (as a control), and 100 mmHg hydrostatic pressure for 7 d. The increase of cell layer thickness was observed. When measured, the cell layer thickness increased by 116.2%. The increase of collagen (Type Ⅳ)synthesis was also observed in the immunohistochemistry assay. When stained with toluidine blue, the cells showed metachromatic phenomenon.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles

AIM To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques.METHODS From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were analyzed.RESULTS Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy(90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity(88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination(score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-m L(P = 0.03, P = 0.014), 10-m L(P = 0.005; P = 0.006) and 20-mL syringes(P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-m L(P = 0.001) and 20-mL syringes(P = 0.007).CONCLUSION The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

细菌细胞被膜压力响应的研究进展

细胞被膜是细菌监测外部环境变化并及时作出响应的第一道屏障,在面对温度、pH、渗透压、金属离子、活性氧以及抗生素压力时,对细胞进行保护。细胞被膜压力响应可以感受细胞被膜损伤,并通过调控转录以缓解压力,其中双组分系统和胞质外功能性σ因子是主要的压力响应系统。同时,越来越多的研究发现,非编码小RNA可与二者协同作用共同调节细胞被膜压力。由于革兰氏阴性菌和阳性菌的被膜结构不同,各自的响应机制也有所差异。该文基于细胞被膜结构,从革兰氏阴性菌和阳性菌两个方面详细介绍了细胞被膜压力响应及其最新研究进展,并展望了细胞被膜压力响应的未来研究方向。

Alpha-fetoprotein expression is a potential prognostic marker in hepatocellular carcinoma

AIM： To characterize the alpha-fetoprotein （AFP） positive and negative hepatocellular carcinoma （HCC） samples. METHODS： Thirty-seven paraffin-embedded human HCC samples were analyzed by immunohistochemistry for the following antigens： AFP,β-catenin, p53, CD44, MSH-2, MLH-1, and HNF-4. The tumors were divided into two groups based on the AFP expression. The immunophenotypic data and important clinical parameters were studied between the two groups. RESULTS： Twenty-one of the thirty-seven examined HCCs were AFP positive. Seven with nudear p53 staining were AFP positive, while seven tumors with nuclear β-catenin staining were AFP negative. CD44 staining and high histological tumor grade were more frequent among the AFP-positive HCCs. The other immunophenotypical and dinical parameters did not show statistically significant difference in their distribution between the AFP positive and negative samples. CONCLUSION： AFP expression in HCC correlates with unfavorable prognostic factors, while nuclear β-catenin positivity is more common among the AFP-negative liver tumors. This observation supports the microarray data on in vivo human tumors.

Sleep-disordered breathing is associated with depletion of circulating endothelial progenitor cells and elevation in pulmonary arterial pressure in patients with decompensated systolic heart failure

Background Sleep-disordered breathing （SDB） is known to occur frequently in and may predict worsening progression of patients with congestive heart failure （CHF）. SDB is also known to play an important role in the development of idiopathic pulmonary arterial hyper- tension （PAH） via inducing endothelial dysfunction and vascular remodeling, a pathological process that can be significantly influenced by factors such as osteoprotegerin （OPG） and endothelial progenitor cells （EPCs）. The objective of this study is to determine if CHF with SDB is associated with changes in OPG, EPCs, and PAIl. Methods EPCs were isolated, cultured, and quantified from CHF patients with SDB （n = 52）, or without SDB （n - 68）. OPG and N-terminal pro-brain natriuretic peptide （NT-proBNP） from each group was analyzed and cor- related with EPCs and the mean pulmonary artery pressure （mPAP） measured by right heart catheterization. Results A significant decrease in circulating EPCs （29.30 ± 9.01 vs. 45.17 ± 10.51 EPCs/x 200 field; P 〈 0.05） was found in CHF patients with SDB compared to those without SDB. Both OPG （789.83 ±89.38 vs. 551.29 ± 42.12 pg/mL; P 〈 0.05） and NT-proBNP （5946.50 ± 1434.50 vs. 3028.60 ± 811.90 ng/mL; P 〈 0.05） were also significantly elevated in SDB CHF patients who also had significantly elevated mPAP （50.2 ± 9.5 vs. 36.4 ± 4.1 mm Hg; P 〈 0.05）. EPC numbers correlated inversely with the episodes of apnea and hypopnea per hour （RDI, r = -0.45, P = 0.037） and blood level of OPG （r =-0.53, P = 0.011）. Although NT-proBNP was also increased significantly in patients with SDB, it had no correlation with either EPCs or RD1. Conclusions SDBdue to hypoxemia from decompensated CHF is associated with （1） OPG elevation, （2） EPC depletion, and （3） mPAP elevation. The inverse relationship of circulating OPG with EPCs suggests a likely mechanism for hypoxemia and OPG in the development of pulmonary vascular dysfunction via depleting EPCs, thus worsening prognosis of CHF.

High glucose augments stress-induced apoptosis in endothelial cells.

Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. EAhy 926 endothelial ceils were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide （HzO2） or tumour necrosis factor- α （TNF- α ）, following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of EAhy 926 cells to apoptosis in the presence of 500 gmol/L H2O2 , above that induced in normal glucose （P〈0.02）. A reduction of H2O2- and TNF- a -induced apoptosis occurred in both high and low glucose after treatment with dexamethasone （P〈0.05）. Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

Development and installation of bedload monitoring systems with submerged load cells

Bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been developed to directly measure bedload discharge. The system consists of： （1） an iron box which is 1 m long, 0.5 m wide and 0.1 m in depth, （2） two submerged load cells 0.7 m apart, （3） a pressure sensor and, （4） an electromagnetic velocity meter. This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight. Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions. The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute （DPRI） of Kyoto University to obtain bedload discharge under natural conditions. Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes. The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells, Bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells. This study clarifies the reasons why bedload measurements are difficult, and provides some solutions using the monitoring systems with submerged load cells through the field measurements. Additionally, the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.

A Method for Calculating Blast Pressure of Failed Lithium-Ion Cells with C-H-O Solvents

Blast pressure of C-H-O solvents on failed lithium-ion cells at the voltage range between 3.8 V and 4.18 V may be calculated by means of the simple semi-empirical equation, y = （Ia ＋ Jb）/（Ka ＋ Lb ＋ Me）, p is the initial density of solvent, Q is the chemical energy of explosion, v is the voltage. The values of a, b, c depend on C-H-O composition. Value of I, J, K, L, Mmay be estimated from the H20-CO2 arbitrary decomposition assumption. Blast pressure derived in this manner can provide preliminary protective estimation and it is compared with experiment results by adiabatic calorimeter.

液泡膜内在蛋白基因OsTIP1;1异位表达对油菜根皮层细胞水分关系参数的影响

在水培条件下,以水稻Os TIP1;1转基因油菜、空载体p HB转基因油菜以及野生型‘沪油15号’油菜为实验材料,用细胞压力探针技术研究正常水分条件和PEG-6000模拟–0.2 MPa水分胁迫条件下,液泡膜内在蛋白基因Os TIP1;1异位表达对油菜根皮层细胞水分关系参数的影响。结果表明,与正常水分条件相比,水分胁迫显著降低了细胞膨压(P)以及细胞水导(Lp),而使细胞壁体积弹性模量(ε)和水分跨膜转运半时间(TW1/2)增加。在两种水分条件下,细胞膨压(P)和细胞水导(Lp)都表现为Os TIP1;1转基因油菜>空载体p HB转基因油菜以及野生型油菜,而Os TIP1;1转基因油菜的TW1/2显著小于其他两种油菜,ε值在正常水分条件下明显小于其他两种油菜,水分胁迫后不同材料间差异不显著。说明水稻液泡膜内在蛋白基因Os TIP1;1在转基因油菜中异位表达可提高油菜根系的水分运输效率。

气孔运动中pH对保卫细胞壁弹性模量的影响

保卫细胞壁的特性对气孔运动有重要的影响.以前的研究多集中于保卫细胞壁的解剖结构,对气孔运动中保卫细胞壁物理性质的改变了解很少.本研究以蚕豆叶片表皮条为材料,运用细胞压力探针技术,对气孔运动中不同pH下的保卫细胞壁弹性模量(??)进行了测量.研究发现,当pH从8.60降至6.50时,保卫细胞壁的弹性模量从7.098Pa降至5.690Pa.气孔运动中,较低的保卫细胞壁弹性模量有利于保卫细胞改变体积,进而有助于气孔运动的完成.从保卫细胞通过调控细胞壁pH改变细胞壁弹性模量的角度来分析气孔运动机理,对于完善气孔运动机理假说,进而深刻理解气孔运动,具有重要的意义.