微小RNA-23a调节前列腺癌细胞骨架蛋白的分子机制

目的 探讨微小RNA-23a(miR-23a)影响前列腺癌细胞骨架迁移及侵袭行为的分子机制.方法 PC-3前列腺癌细胞转染siPAK6、miR-23a模拟物,48 h后以共聚焦显微镜观察细胞骨架的改变;Western blot法检测LIMK1、磷酸化LIMK1( p-LIMK1)、丝切蛋白(cofilin)和磷酸化丝切蛋白(p-eofilin)蛋白的表达.结果 转染siPAK6组及miRNA-23a组PC-3细胞骨架的应力纤维均明显减少,肌动蛋白形态皱缩.Western blot检测显示转染siPAK6组的p-LIMK1、p-cofilin的表达分别下降75％、80％(P＜0.01),而LIMK1、cofilin表达量无明显变化(P＞0.05);转染miRNA-23a组的p-LIMK1、p-cofilin的表达分别下降60％、70％ (P ＜0.01),LIMK1、cofilin的表达量无明显变化(P＞0.05).结论 miR-23a可通过p21活化激酶6(PAK6)-LIMKl-cofilin信号通路,影响前列腺癌细胞骨架的重构,抑制癌细胞迁移及侵袭能力.     

双螺杆挤压对香菇膳食纤维色泽的影响

香菇膳食纤维采用双螺杆挤压机进行挤压处理.通过响应面分析方法对不同操作变量(螺杆转速、套筒温度、喂料水分)对产品色泽(以L、A、B值表示)的影响进行了探讨.总体而言，挤压处理使其L值低于原料组(对照组)，而A值高于原料组，B值介于对照组及挤压组之间，在高螺杆转速、低套筒温度、高喂料水分操作条件下L、A及E值变化最小.     

酸敏感离子通道1a在视网膜色素上皮细胞氧化损伤过程中的作用

目的 观察酸敏感离子通道1a( ASIC1 a)在视网膜色素上皮细胞(RPE)氧化损伤过程中的作用.方法 采用实时逆转录-聚合酶链反应(RT-PCR)以及Western blot的方法检测RPE在1 mmol/L H2O2诱导的细胞氧化损伤过程中(0.5 ～4.0 h),ASIC1a的表达变化;同时分别采用ASICs阻断剂amiloride和PCTx1,以及通过细胞转染ASIC1a,检测对该氧化损伤过程的影响,并应用噻唑蓝(MTT)比色法评价细胞的活性.结果 实时RT-PCR以及Western blot的结果均显示RPE中ASIC1a在mRNA及蛋白水平均有表达.1mmol/L H2O2处理RPE 1、2、4h后,RPE中ASIC1a的蛋白表达明显降低至(70.5±11.0)％、(40.6±5.6)％和(45.6±7.6)％.PCTx1阻断ASIC1a后,RPE细胞存活率明显降低,至4h细胞存活率为(76.2±5.0)％(与对照组比较,P＜0.05),而过表达ASIC1a能够提高RPE氧化损伤过程中细胞的存活率,与H2O2处理组比较,4h组为(38.0±6.0)％比(16.2±2.0)％(P＜0.05).结论 ASIC1a在RPE中具有表达并对RPE的氧化损伤具有一定的细胞保护作用.     

下调微小RNA-19a对胶质瘤细胞侵袭能力的影响及机制

目的 探讨下调微小RNA(miR)-19a的表达对人脑胶质瘤细胞株U87侵袭能力的影响及其机制.方法 采用实时荧光定量聚合酶链反应(FQ-PCR)检测转染miR-19a抑制物的效率.转染后48 h,采用Western blot法检测U87细胞中多亮氨酸重复区免疫球蛋白样蛋白1(LRIG1)的表达,并通过Transwell实验检测U87细胞的侵袭能力.构建报告质粒,于转染后72 h用荧光素酶报告实验验证miR-19a和LRIG1的相互作用.结果 FQ-PCR结果显示转染miR-19a抑制物后,U87中miR-19a的表达量较对照组降低了(78.2±5.1)％,差异有统计学意义(P＜0.01).转染miR-19a抑制物后,U87穿膜细胞数较对照组明显减少,分别为(25.9±3.9)个和(85.3±6.1)个(P＜0.01).荧光素酶报告实验结果显示,下调miR-19a后野生型报告质粒的荧光素酶活性较对照组升高(4.89±0.26)倍(P＜0.01),而突变型质粒的荧光素酶活性较对照组无明显变化.Transwell实验结果表明在下调miR-19a后,LRIG1沉默组的穿膜细胞数较对照组明显增加,分别为(47.8±3.1)个和(22.7±4.2)个(P＜0.05).结论 下调miR-19a可以抑制U87细胞的侵袭力,其机制可能是上调LRIG1的表达.     

microRNA-449a靶向Notch1抑制膀胱癌细胞J82的迁移

【摘要】〓目的〓研究microRNA-449a(miR-449a)对膀胱癌细胞J82迁移能力的影响以及对靶基因Notch1表达的影响。方法〓通过mimics转染膀胱癌细胞株J82使其过表达miR-449a,利用Transwell实验、细胞划痕实验观察细胞迁移能力的变化;采用实时定量PCR和蛋白印迹检测细胞Notch1表达水平的变化,并通过荧光素酶实验验证miR-449a与Notch1基因的直接调控关系。结果〓与对照组相比,转染miR-449a组的J82细胞的迁移能力减弱。过表达miR-449a后,J82细胞Notch1的mRNA表达无明显变化(P=0.5739),但Notch1蛋白表达下调(P=0.0135)。荧光素酶报告基因实验显示,miR-449a能明显抑制Notch1-3’UTR的荧光素酶活性(P=0.0016)。结论〓过表达miR-449a可能通过靶向降低Notch1基因的蛋白表达,抑制膀胱癌细胞的迁移。     

静水压对软骨细胞凋亡和增殖细胞核抗原表达的影响

目的 探讨静水压对软骨细胞凋亡和增殖的影响及肿瘤坏死因子(TNF)-á和白细胞介素(IL)-1a与软骨细胞凋亡的关系.方法 兔膝关节软骨细胞放置在压力装置中采用不同持续时间(0、4、16、24h)和不同大小静水压力刺激(0、20、40、70 kp)后观察其凋亡及PCNA表达,测定相应细胞培养基中TNF-á和IL-1a的值.结果 软骨细胞受到不同大小静压力后,作用早期细胞凋亡显著(P＜0.05),随时间延长凋亡值出现不同的变化.PCNA的表达在不同的压力下和对照组比较均有差异有统计学意义(P＜0.05).TNF-á可重复双因素分析,时间和压力的交互作用(F=6.90,P＜0.01).IL-1a可重复双因素分析,时间和压力的交互作用(F=5.80,P＜0.01).结论 软骨细胞在持续高压力应力下凋亡增加,增殖减少;在持续低压力时出现相反的结果 .软骨细胞的凋亡和增殖和TNF-á和IL-1a变化有一定的相关性.     

地塞米松对利多卡因神经毒性的保护作用

目的 观察地塞米松(Dex)对利多卡因(Lido)诱导小鼠神经母细胞瘤细胞株(N2a)毒性的影响.方法 用0、100、250、500、1 000和1 500 μmol/L Lido孵化N2a细胞9 h后,将细胞分为对照(Con)组、Lido组、Dex组和Dex+Lido组.观察细胞形态学变化,并检测细胞凋亡率和细胞Akt磷酸化水平.结果 (1)与0 μmol/L Lido 比较,100、250和500 μmol/L Lido未引起明显细胞形态学变化,而1 000和1 500 μmol/L Lido引起显著细胞损伤;100和250 μmol/L Lido未引起明显的细胞凋亡增加,而500、1 000、1 500 μmol/L Lido分别引起轻度、中度和重度细胞凋亡(P<0.01).(2)Dex+Lido组核固缩率显著低于Lido组(P<0.01).(3)Dex+Lido组N2a细胞中Akt磷酸化水平显著高于IAdo组(P<0.01).结论 Lido呈浓度依赖性地诱导N2a细胞损伤,Dex预处理显著减轻Lido所致的细胞损伤,其保护机制与抑制Lido诱导的Akt脱磷酸化有关.     

大黄素与善得定对重症胰腺炎二十碳烯酸类代谢的影响

目的;观察大黄素与善得定对重症胰腺炎(AHNP)二十碳烯酸类代谢的影响.方法:以牛磺胆酸钠诱发大鼠AHNP模型,观察前列腺素E_2(PGE_2)、6-酮-前列腺素F_1a(6-keto-PGF_1a)、血栓烷B_2(TXB_2)等变化以及大黄素、善得定的作用.结果:重症胰腺炎发病6小时血浆TXB_2增高达假手术组的4.5倍;6-keto-PGF_1a以及PGE_2则呈下降趋势.大黄素或善得定组TXB_2增高显著受抑制;PGE_2和6-keto-PGF_1a则见上升趋势.两治疗组12小时的生存率显著高于非治疗组;病理组织学评分及电镜超微结构观察示给药组胰腺细胞坏死现象减轻.结论:大黄素和善得定能调整AHNP时TXB_2等的异常代谢,胰循环与细胞保护机制的改善可能是两药治疗的重要药理基础.     

酪蛋白酸钠膜的水分吸附特性

作者以大豆蛋白酪蛋白酸钠(NaCas)膜为对象,从吸附动力学和水分吸附等温线研究了蛋白膜的水分吸附特性.NaCas膜水分达到平衡所需要的时间受到所处相对湿度(RH)条件和增塑剂含量的影响.RH和增塑剂含量越低,达到平衡的时间越短;反之,则越长.TGase改性明显降低了蛋白膜的水分吸附速率及达到平衡的水分含量.NaCas膜水分吸附等温线数据能很好地与GAB模型吻合.     

LncRNA H19/miR-203a/PTEN轴在小鼠GC-1细胞缺血再灌注损伤中的作用及影响机制

目的:探讨长链非编码RNA(lncRNA) H19在小鼠体外GC-1细胞的表达,以及其通过调控微小RNA(miRNA)-203a/磷酸酯酶与张力蛋白同源物(PTEN)轴对GC-1细胞凋亡和增殖的影响。方法:建立GC-1细胞体外缺氧复氧模型,qRT-PCR检测GC-1细胞不同复氧损伤时间点lncRNA H19的表达变化;MTT法、流式细胞术测定沉默lncRNA H19对GC-1细胞增殖和凋亡的影响;Western印迹检测沉默lncRNA H19对GC-1细胞凋亡相关蛋白Bax和caspase-3表达的影响;qRT-PCR和Western印迹分别测定沉默lncRNA H19后GC-1细胞miR-203a和PTEN的表达变化。结果:随着复氧损伤时间的增加,GC-1细胞lncRNA H19表达明显增加,在缺氧3 h/复氧12 h达到峰值,与此同时miR-203a表达明显降低。此外,沉默lncRNA H19增强了GC-1细胞的增殖能力并降低了其凋亡水平,增加了miR-203a表达水平并降低了PTEN表达水平,结果显著。结论:LncRNA H19在体外GC-1细胞中高表达,其可能通过调控miR-203a/PTEN信号途径改变GC-1细胞增殖及凋亡的能力。     

超声弹性分级法鉴别诊断甲状腺实性结节的良恶性

目的探讨超声弹性成像分级法在甲状腺实性结节良恶性鉴别诊断中的价值及不同医师之间的诊断一致性。方法 72例(89个)甲状腺实性结节患者接受超声检查,由2名医师以超声弹性成像分级法进行分级,并将分级结果与术后病理结果进行对比研究。结果医师1以超声弹性成像分级法诊断恶性甲状腺结节的敏感度、特异度、准确率、阳性预测值及阴性预测值分别为82.93%(34/41)、83.33%(40/48)、83.15%(74/89)、80.95%(34/42)、85.11%(40/47);医师2分别为85.37%(35/41)、81.25%(39/48)、83.15%(74/89)、79.55%(35/44)、86.67%(39/45)。两名医师诊断一致率为95.55%,Kappa=0.752。结论超声弹性成像分级法对甲状腺实性结节良恶性鉴别诊断具有较好的应用价值,不同医生独立完成弹性成像的一致性较好。     

Intraoral moisture during operation under general anesthesia

BACKGROUND: Intra-operative intraoral moisture was examined using a moisture checker, on the hypothesis that as an operation is prolonged, the intraoral moisture decreases; consequently, intraoral drying level should increase. METHODS: This hypothesis was tested on 27 adult patients undergoing a regular operation. The subjects having fasted since 0:00 o'clock of the operation day entered the operating room, where their intraoral moisture was measured using an intraoral moisture checker (Life Co. Ltd., Tokyo) (the unit is % index). Then, propofol administration was started with simulated blood concentration of 4 microg x ml(-1). Anesthesia was induced with vecuronium 1 mg x kg(-1) and fentanyl 1.5 microg x mg(-1). Every hour from anesthesia induction to the end of operation, intraoral moisture was checked. The propofol simulated blood concentration during operation was set to remain at 2-3.5 microg x ml(-1), with fentanyl administered. Statistical analysis was done by two factor factorial ANOVA. P < 0.05 was considered significant. RESULTS AND CONCLUSIONS: The intraoral moisture during operation under general anesthesia showed no chronologically significant difference.     

Measurement of heat and moisture exchanger efficiency

Deciding between a passive heat and moisture exchanger or active humidification depends upon the level of humidification that either will deliver. Published international standards dictate that active humidifiers should deliver a minimum humidity of 33 mg.l^?1; however, no such requirement exists, for heat and moisture exchangers. Anaesthetists instead have to rely on information provided by manufacturers, which may not allow comparison of different devices and their clinical effectiveness. I suggest that measurement of humidification efficiency, being the percentage moisture returned and determined by measuring the temperature of the respired gases, should be mandated, and report a modification of the standard method that will allow this to be easily measured. In this study, different types of heat and moisture exchangers for adults, children and patients with a tracheostomy were tested. Adult and paediatric models lost between 6.5 mg.l^?1 and 8.5 mg.l^?1 moisture (corresponding to an efficiency of around 80%); however, the models designed for patients with a tracheostomy lost between 16 mg.l^?1 and 18 mg.l^?1 (60% efficiency). I propose that all heat and moisture exchangers should be tested in this manner and percentage efficiency reported to allow an informed choice between different types and models.     

The effect of a heat and moisture exchanger on humidity in a low-flow anaesthesia system

The heat and humidity in a low-flow breathing system was measured in order to study the inherent humidifying properties of the system at low fresh gas flows (< 1 and 2 l.min⁻¹) and whether a heat and moisture exchanger could compensate for the loss of heat and humidification occurring at higher fresh gas flows (5 l.min⁻¹) in these systems. Sixty patients were randomly divided into three groups (< 1, 2 and 5 l.min⁻¹ fresh gas flows) with a heat and moisture exchanger and three groups without a heat and moisture exchanger in the breathing system. Thirty minutes after the start of anaesthesia a control measurement was performed, after which a heat and moisture exchanger was inserted into the breathing system of the three groups randomly allocated to have one. Three more measurements were performed at 10, 30 and 60 min after control. At low fresh gas flows the humidifying properties of the low-flow breathing system are adequate (i.e. provide an absolute humidity > 20 mg.l⁻¹) but at a fresh gas flow of 5 l.min⁻¹ there is a need for a heat and moisture exchanger for adequate humidification of the inspired gas.     

Subepidermal moisture detection of pressure induced tissue damage on the trunk: The pressure ulcer detection study outcomes

We examined the relationship between subepidermal moisture measured using surface electrical capacitance and visual skin assessment of pressure ulcers at the trunk location (sacral, ischial tuberosities) in 417 nursing home residents residing in 19 facilities. Participants were on average older (mean age of 77 years), 58% were female, over half were ethnic minorities (29% African American, 12% Asian American, and 21% Hispanic), and at risk for pressure ulcers (mean score for Braden Scale for Predicting Pressure Ulcer Risk of 15.6). Concurrent visual assessments and subepidermal moisture were obtained at the sacrum and right and left ischium weekly for 16 weeks. Visual assessment was categorized as normal, erythema, stage 1 pressure ulcer, Deep Tissue Injury or stage 2+ pressure ulcer using the National Pressure Ulcer Advisory Panel 2009 classification system. Incidence of any skin damage was 52%. Subepidermal moisture was measured with a dermal phase meter where higher readings indicate greater moisture (range: 0–70 tissue dielectric constant), with values increasing significantly with the presence of skin damage. Elevated subepidermal moisture values co‐occurred with concurrent skin damage in generalized multinomial logistic models (to control for repeated observations) at the sacrum, adjusting for age and risk. Higher subepidermal moisture values were associated with visual damage 1 week later using similar models. Threshold values for subepidermal moisture were compared to visual ratings to predict skin damage 1 week later. Subepidermal moisture of 39 tissue dielectric constant units predicted 41% of future skin damage while visual ratings predicted 27%. Thus, this method of detecting early skin damage holds promise for clinicians, especially as it is objective and equally valid for all groups of patients.     

葡萄糖转移方法检测脂肪颗粒活性的研究

目的 以高速离心为损伤模型,了解以葡萄糖转移量来体现组织块活性的可能性、可靠性,建立新的脂肪颗粒活性检测方法,为脂肪移植研究提供一基础.方法 将同条件抽取的脂肪颗粒分为5组,分别经1 000、2000、3 000、4 000、5 000 r/min离心纯化后,每组得60 ml样本,每个样本分为12个实验标本（5 ml/标本）置于12个培养皿中（内含10 mlDMEM、1 U正规胰岛素/皿）,每组设一个不含脂肪颗粒的空白标本,所有标本同时进行孵育,1 h后测量每个标本DMEM中葡萄糖的浓度.以5组空白标本的葡萄糖浓度均值为基础浓度,其与每个实验标本的葡萄糖浓度差值代表标本的葡萄糖转移量即活性.t检验分析比较每组标本的活性.将5组样本送病理学检查,比较各组切片完整细胞数,并与上述实验结果进行对比.结果 各组样本经含糖DMEM孵育后,其葡萄糖转移量即活性用SNK方差分析检验得出：1 000 r/min组＞2 000 r/min组＞3 000 r/min组＞4 000 r/min组,5000 r/min组与4 000 r/min组比较,差异无统计学意义,但显著小于前4组（P＜0.05）,即随离心速率增大,脂肪颗粒活性逐渐下降.病理切片显示：5 000 r/min组大部分细胞壁形态不规则或碎裂.完整细胞计数结果用SNK方差分析检验得出：5 000 r/min组明显较其他各组少（P＜0.05）;其他4组完整细胞数差异无统计学意义（P＞0.05）.结论 葡萄糖转移实验可较准确地检测脂肪颗粒活性的活性状态,病理学检查在反应脂肪颗粒活性方面有局限性.     

Subepidermal moisture detection of heel pressure injury: The pressure ulcer detection study outcomes

We examined subepidermal moisture (SEM) and visual skin assessment of heel pressure injury (PrI) among 417 nursing home residents in 19 facilities over 16 weeks. Participants were older (mean age 77 years), 58% were female, over half were ethnic minorities (29% African American, 12% Asian American, 21% Hispanic), and at risk for PrI (mean Braden Scale Risk score = 15.6). Blinded concurrent visual assessments and SEM measurements were obtained at heels weekly. Visual skin damage was categorised as normal, erythema, stage 1 PrI, deep tissue injury (DTI) or stage 2 or greater PrI. PrI incidence was 76%. Off‐loading occurred with pillows (76% of residents) rather than heel boots (21%) and often for those with DTI (91%). Subepidermal moisture was measured with a device where higher readings indicate greater moisture (range: 0‐70 tissue dielectric constant), with normal skin values significantly different from values in the presence of skin damage. Subepidermal moisture was associated with concurrent damage and damage 1 week later in generalised multinomial logistic models adjusting for age, diabetes and function. Subepidermal moisture detected DTI and differentiated those that resolved, remained and deteriorated over 16 weeks. Subepidermal moisture may be an objective method for detecting PrI.     

Biological experimental models in orthopedics]

Experimental research in orthopedics is conducted on different experimental models. Animal models have to be characterized by high similarity and consistence of the animal bone tissue with human metabolism and must undergo similar biomechanical changes. This paper presents the advantages and disadvantages of the most commonly used animal models, with particular attention given to sheep.     

Effectiveness of a heat and moisture exchanger in preventing hyperpnoea induced bronchoconstriction in subjects with asthma.

The effect of a heat and moisture exchanger, a device with hygroscopic material for conditioning inspired air, on hyperpnoea induced bronchoconstriction was studied in nine non-smoking volunteers with asthma, aged 19-32 years. Each had previously shown an increase of at least 100% in specific airways resistance (sRaw) to isocapnic hyperpnoea with dry air. On two separate days the subject performed isocapnic hyperpnoea with dry air at 60-70 l min-1 for five minutes. Before, immediately after, and five minutes after completion of a test sRaw measurements were made. Heat and moisture exchangers were placed in the breathing circuit on one of the two days. All subjects had an increase in sRaw of 100% or more without the heat and moisture exchangers (average increase 300%) but were protected from bronchoconstriction with the devices in place (average increase 7%) (p less than 0.005). The exchanger's resistance to airflow was less than 1 cm H2O for flow rates of 100 l min-1. A heat and moisture exchanger designed as a facemask or mouthpiece may allow a person with asthma to exercise without the need for prophylactic drugs.     

Larsen's syndrome

A girl with the characteristic abnormalities of Larsen's syndrome is presented. A soft flabby consistence of the cartilaginous skeleton of the larynx and trachea was thought to be the cause of attacks of respiratory failure which suddenly caused her death at the age of 9 months. Microscopy revealed a considerably reduced number of elastic fibres in the larynx, trachea and bronchi. Closed reduction of the knee dislocation by skin traction seemed to be successful.