组织因子途径抑制物2抑制胰腺癌血管生成的研究

目的研究组织因子途径抑制物2（TFPI-2）对胰腺癌血管生成的影响，探讨其抑制胰腺癌生长及侵袭、转移的机制。方法建立裸鼠角膜微囊移植模型，将3组细胞Pane-1TFPI-2、Pane-1-P和Pane-1-V分别接种裸鼠角膜微囊，观察角膜新生血管的形成；再将上述3组细胞接种于裸鼠皮下，观察裸鼠皮下肿瘤生长及转移情况，并采用抗CD34抗体进行血管免疫组织化学染色检测皮下肿瘤的微血管密度（MVD）。Pane-1-TFPI-2组为实验组，Panc-1-P和Pane-1-V组作为对照组。结果实验组角膜新生血管积分比对照组明显减少（P〈0．05），实验组和对照组裸鼠皮下均成瘤，实验组肿瘤体积（438．0±69．8）mm^3，对照组分别为（852．0±102．9）mm^3和（831．0±78．1）mm^3（P〈0．05）；同对照组比较，实验组未见明显远处转移，其肿瘤微血管密度（9．68±1．12），对照组分别为（18．69±2．51）和（20．32±2．08），差异有统计学意义（P〈0．05）。结论组织因子途径抑制物2能抑制肿瘤血管的形成，抑制胰腺癌生长。     

丙戊酸钠诱导胃癌细胞凋亡及其机制

目的观察丙戊酸钠（VPA）对胃癌细胞系BGC-823的生长抑制及诱导凋亡作用．并通过检测半胱氨酸天冬氨酸蛋白酶（caspase3、caspase8、caspase9）的活性和蛋白表达变化探讨VPA诱导凋亡的可能机制。方法M1Tr法检测细胞生长抑制、Annexin V／PI双染检测细胞凋亡、间接免疫荧光法分析caspase3、caspase8、caspase9蛋白变化，分光光度法检测caspase3、caspase8、caspase9活性改变。结果VPA0．75～4．00mmol／L干预BGC-823细胞24h和48h后，细胞生长被明显抑制，细胞凋亡率显著增加[VPA0．75mmol／L，24h时细胞凋亡率为（7．2±0．5）％，48h时为（9．2±1．0）％；VPA4．00mmol／L，24h时为（16．7±2．2）％，48h时为（20．4±1．6）％]，与对照组[24h时细胞凋亡率为（4．9±0．2）％，48h时为（5．1±0．8）％]比较．差异有统计学意义（P〈0．001），并呈时间、剂量依赖趋势；caspase3、caspase9蛋白表达被明显上调．活性升高．与对照组比较，差异有统计学意义（P〈0．001）。caspase8活性及蛋白表达在VPA作用24h后未见明显改变，48h后仅轻度增加。结论VPA可明显抑制胃癌细胞的生长并诱导其凋亡，而且该作用主要通过激活caspase9介导的内源性凋亡途径实现；caspase8介导的外源性细胞凋亡途径未参与或仅部分参与了该诱导过程。     

组织因子途径抑制物2基因对Panc-1细胞裸鼠成瘤及转移的影响

目的观察组织因子途径抑制物2（TFPI-2）对胰腺癌细胞系Pane-1细胞裸鼠成瘤及转移的影响。方法将Pane-1-TFPI-2细胞接种到裸鼠皮下作为实验组，观察肿瘤生长情况并测量其大小；取皮下新生肿瘤组织进行原位胰腺接种，观察其对周围组织浸润及远处转移能力的影响。同时以Pane-1-V和Pane-1-P细胞作为对照组。结果实验组和对照组裸鼠皮下均成瘤，但实验组肿瘤体积小于对照组，分别为（438．0±69．8）、（852．0±102．9）和（831．0±78．1）mm’，差异有统计学意义（P〈0．05）。原位胰腺接种，对照组移植瘤浸润胰腺组织，有肝、肺、淋巴结及腹膜转移灶形成，免疫染色显示转移灶CEA阳性，证实其为胰腺肿瘤转移而来。实验组移植瘤包膜完整，无明显浸润及转移现象。结论TFPI-2能抑制肿瘤细胞生长、周围组织浸润及远处转移，为胰腺癌的基因治疗奠定了实验基础。     

反义调控DNA甲基转移酶1基因对人胆管癌细胞生长的抑制效应

目的观察转染反义DNMT1基因真核表达载体对人胆管癌细胞QBC-939生长的影响,初步探讨DNMT1基因在胆管癌发生中的表遗传学机制。方法将构建好的反义DNMT1基因真核表达载体用脂质体介导法转入人胆管癌细胞QBC-939,Western blot检测转染前后DNMT1蛋白的表达变化,MTT法和软琼脂克隆形成试验观察各组细胞的生长增殖能力,流式细胞术观察细胞生长周期及凋亡率的变化。结果（1）Western blot检测证实转染反义基因能使DNMT1蛋白表达水平降低;（2）转染反义DNMT1基因能抑制QBC-939的生长曲线,并使其软琼脂克隆形成率从（38．020±4．120）％减少至（14．860±2．129）％,差异有显著性意义（P=0．000）;（3）转染反义DNMT1基因能影响QBC-939的细胞周期,使之阻滞于G1期,细胞凋亡率从（1．63±0．27）％增加到（6．19±0．78）％,差异亦有显著性意义（P=0．000）。结论通过转染反义DNMT1基因真核表达载体,可下调DNMT1在QBC-939细胞中的表达水平,并能抑制胆管癌细胞的生长和增殖,促进凋亡的发生,提示DNMT1可能通过甲基化途径与胆管癌的发生有关。     

粘着斑激酶在PDGF-BB诱导MHCC-97H细胞黏附侵袭中的作用

目的观察不同浓度血小板衍生生长因子（PDGF-BB）诱导MHCC-97H细胞中粘着斑激酶（focal adhesion kinase，FAK）mRNA的动态变化及FAK在细胞黏附、侵袭的作用。方法不同浓度（1，2．5，5，10，25ng／m1）PDGF-BB诱导MHCC-97H人肝癌细胞，Real-time PCR方法检测FAK及MMP-2的mRNA动态变化，黏附实验、侵袭实验分别检测诱导后MHCC-97H细胞的黏附、侵袭能力的变化。结果诱导后MHCC-97H细胞FAKmRNA水平上调，在10ng／ml浓度时达到最高，为对照组的112．6倍；MMP-2mRNA水平上调并与FAKmRNA水平上调呈一致性，在10ng／ml浓度时达到最高，为对照组的56．9倍。诱导后各组黏附率分别为（66±1．84）%、（69±1．41）％、（69±2．42）％、（71±1．37）%和（66±3．28）%，与对照组的（54±2．08）％比较均有统计学意义（P〈0．001）；诱导后5ng／ml和10ng／ml组侵袭细胞数分别为（26．63±4．5）、（28．75±4．2）个，与对照组（21．5±4．0）个比较有显著性差异（P〈0．05，P〈0．001）。诱导后黏附率与侵袭细胞数变化在10ng／ml浓度时都达到高峰。结论PDGF-BB上调MHCC-97H细胞中FAK表达，上调FAK促进MHCC-97H细胞的黏附和侵袭能力。     

良性脑膜瘤Ets-1和基质金属蛋白酶-9的表达及其与肿瘤复发的关系

目的 探讨良性脑膜瘤中E26转录因子-1（E26transformation-specific-1，Ets-1）和基质金属蛋白酶-9（MMP-9）的表达及其与肿瘤复发的关系。方法 选取52例SimpsonI级切除的良性脑膜瘤采用免疫组织化学法检测Ets-1和MMP-9的表达，分析其参数与肿瘤复发的关系。结果 Ets-1的表达：非复发组免疫组织化学（IHC）评分为（2．8±1．7），复发组为（6．3±1．5），复发组较非复发组的IHC评分增高，两者差异有统计学意义（P〈0．01）。MMP-9的表达：非复发组IHC评分为（2．2±1．8），复发组为（3．3±1．7），复发组较非复发组的IHC增高，两者差异有统计学意义（P〈0．05）。Ets-1和MMP-9的表达具有呈显著正相关（γ=0．822，P〈0．01）。结论 Ets-1正性调节MMP-9的表达水平；Ets-1和MMP-9可以作为预测良性脑膜瘤复发的危险因素。     

增殖细胞核抗原小干扰RNA对人结肠癌CaCO2细胞抑制作用

目的 观察增殖细胞核抗原（PCNA）小干扰RNA（siRNA）对人结肠癌CaCO2细胞抑制作用。方法 WST-8法和克隆形成抑制研究No．2和No．4PCNAsiRNA对CaC02细胞的作用；碘化丙锭（PI）单染检测细胞周期，Hochest33258染色观察凋亡形态，膜联蛋白（Annexin）V和PI双染测定捅亡百分率。结果 No.2和No．4PCNA siRNA与CaCO2细胞作用，增殖抑制率分别为（72．24±1.01）％和（74.67±3．35）％；克隆形成抑制率均达90％；两种药物转染细胞均出现明显亚二倍体峰，Sub-G1＋Go／G1期减少，S＋G2／M期增多；siRNA处理组细胞有较多凋亡形态变化；凋亡率随浓度增加而增加，且早期凋亡率持续高于晚期捅亡／坏死率。结论 PCNAsiRNA显著抑制人结肠癌CaCO2细胞增殖及克隆形成；细胞停留于G2／M期，明显诱导细胞凋亡。     

乙酰肝素酶反义寡核苷酸对人胰腺癌细胞侵袭力的抑制作用

目的探讨HPSE AS-ODN对人胰腺癌细胞HPSE基因、蛋白表达及体内、外侵袭力的抑制作用。方法用脂质体将HPSE AS-ODN转染Panc-1细胞,逆转录-聚合酶链反应(RT- PCR)和Western印迹法分别检测转染后HPSE mRNA和蛋白表达;Transwell法检测体外侵袭力。建立裸鼠皮下Panc-1肿瘤模型,按10 mg／kg体重瘤体内注射AS-ODN隔日1次×10。治疗结束后断颈处死裸鼠,剥瘤称重,计算抑瘤率。结果 AS-ODN组mRNA和蛋白表达受到明显抑制,体外侵袭细胞数(个／视野)为60．00±9．31,体内平均瘤重(g)为1．860±0．505;对照组和NS-ODN组体外侵袭细胞数分别为253．00±9.35和240．75±9．36,体内平均瘤重分别为2．948±0．483和2．768± 0．615。AS-ODN组与对照组相比差异有统计学意义(P<0．01)。结论 AS-ODN抑制人胰腺癌细胞 HPSE mRNA和蛋白的表达,并降低癌细胞的侵袭力。     

人类恶性胶质瘤细胞中变异型IκBα对基质金属蛋白酶-2、-9表达的调节作用

目的 探讨变异型IκBα（IκBαM）基因对人类多形性胶质母细胞瘤（GBM）细胞中基质金属蛋白酶（MMP）-2、-9表达的调控作用。方法 通过构建质粒、基因转染以及IκBαM蛋白表达的筛选，建立稳定表达IκBαM的人类GBM细胞株，运用逆转录．聚合酶链反应（RT-PCR）技术检测细胞及肿瘤组织内MMP-2、MMP-9在RNA水平的表达；并将肿瘤细胞植入裸鼠皮下制作异位移植瘤生长动物模型，进一步通过免疫组织化学染色方法分析MMP-2、MMP-9的蛋白表达。结果RT-PCR结果显示，体外试验中，MMP-2与对应GAPDH平均吸光度值的比值分别为1．450±0．180（G36Δ-W）、0．292±0．040（G36Δ-M）、1．187±0．140（G36Δ-P）和1．463±0．160（G36Δ）；MMP-9与对应GAPDH平均吸光度值的比值分别为1．424±0．130（G36Δ-W）、0．275±0．020（G36Δ-M）、1．357±0．180（G36Δ-P）和1．608±0．240（G36Δ）。在体内试验中，MMP-2与对应GAPDH平均吸光度值的比值分别为0．870±0．060（G36Δ-W）、0．024±0．010（G36Δ-M）、0．785±0．070（G36Δ-P）和0．686±0．070（G36Δ）；MMP-9与对应GAPDH平均吸光度值的比值分别为0．768±0．010（G36Δ-W）、0．054±0．010（G36Δ-M）、0．802±0．020（G36Δ-P）和0．746±0．020（G36Δ）。在体外和体内试验中，G36Δ-M组与其余各组之间的差异均有统计学意义（P〈0．05），而其他3组间差异无统计学意义。体内试验肿瘤组织中，MMP-2及MMP-9的在G36Δ-M组中的染色显著低于G36Δ、G36Δ-W和G36Δ-P组；而在G36Δ、G36Δ-W和G36Δ-P三组间的表达差异无统计学意义。结论 IκBαM基因可以在分子及蛋白水平显著抑制人类恶性胶质瘤中MMP-2、MMP-9的表达，减弱肿瘤细胞的侵袭和浸润能力。     

全反式维甲酸和三氧化二砷协同诱导胰腺癌细胞凋亡

目的研究与三氧化二砷（As2O2）具有协同效应治疗胰腺癌的药物。方法以胰腺癌细胞系SWl990为研究对象，观察5-氟尿嘧啶（5-Fu）、健择（Gemcitabine）和全反式维甲酸（AT—RA）与As2O3共同作用对细胞的影响。通过台盼蓝拒染法检测细胞生长和细胞活力，流式细胞仪检测AnnexinV或PI阳性细胞的含量，评价以上药物对细胞增殖和凋亡的作用。结果5-Fu和Gemcitabine与As2O3无协同效应。单独应用As2O3或ATRA均抑制SWl990细胞生长，不诱导细胞凋亡。其中，对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3组为（4．4±0．1）×10^5个／ml，ATRA组为（6．7±0．2）×10^5个／ml。但是，As203和ATRA共同处理SWl990细胞后，细胞生长明显抑制，并诱导细胞凋亡。对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3＋ATRA组为（3．3±0．1）×10^5个／ml；对照组细胞活力为（92，0±1．2）％，As2O3组为（90．0±1．3）％，ATRA组为（93．0±1．4）％，As2O3＋ATRA组为（65．0±2．1）％；对照组Annexin V和PI阳性细胞的含量为（6．0±1．2）％，As2O3组为（11．0±3．3）％，ATRA组为（5．0±1．4）％，As2O3＋ATRA组为（37．0±5．3）％。结论As2O3和ATRA可协同诱导胰腺癌细胞凋亡，两者联合应用可能作为胰腺癌辅助治疗的另一选择。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.