柚皮素对结直肠癌细胞侵袭能力及细胞中MMP-2、MMP-9表达的影响

目的探讨柚皮素对结直肠癌细胞侵袭能力及细胞中基质金属蛋白酶(MMP)-2、MMP-9表达的影响。方法以人结直肠癌细胞SW620为研究对象,分别用0、10、20、40、60、80、120μg/ml的柚皮素作用于SW620细胞,培养48 h后,四甲基偶氮唑盐(MTT)检测细胞增殖能力并计算半数抑制浓度。0、50μg/ml的柚皮素作用于SW620细胞48 h后,Transwell小室检测细胞侵袭能力,Western印迹检测细胞中MMP-2、MMP-9、发状分裂相关增强子1(Hes1)、Notch神经同源蛋白1前体(Notch1)表达水平。结果 10、20、40、60、80、120μg/ml的柚皮素作用后的细胞存活率均明显低于0μg/ml柚皮素作用组(P<0.01)。计算半数抑制浓度为(51.76±1.48)μg/ml。50μg/ml柚皮素作用后的侵袭细胞数目及细胞中MMP-2、MMP-9、Hes1、Notch1水平均明显低于0μg/ml柚皮素作用组(P<0.01)。结论柚皮素能够抑制结直肠癌细胞增殖、侵袭能力,作用机制可能与Notch1信号通路有关。     

雷公藤配伍金钱草抗肺癌增效作用的组成配比及其量效关系

目的考察雷公藤(LGT)配伍金钱草(JQC)体外抗人非小细胞肺癌(NSCLC)A549细胞增效作用的组成配比及其量效关系。方法将LGT与JQC按照不同质量配比(1/4、1/2、1/1、2/1、4/1)混合后,分别用水和75%乙醇回流提取,制备LGT/JQC饮片不同质量配比的提取物;采用体外MTT法检测LGT-JQC不同配比配伍提取物(200μg/ml)对人A549细胞增殖抑制的影响,确定LGT-JQC配伍增效作用的最佳组成配比;进一步采用体外MTT法检测最佳组成配比的提取物对人A549细胞增殖抑制作用的量效关系,计算其半数抑制浓度(IC50)。结果 LGT-JQC在质量配比2/1~4/1配伍的醇提物(200μg/ml)具有抑制NSCLC A549细胞增殖的增效作用(P0.05),且配比在2/1时增效作用最强(与配比4/1组比较,P0.01),而LGT-JQC配伍的水提物(200μg/ml)在既定配比下均无增效作用(P0.05);LGT-JQC配比在2/1(最佳配比)的醇提物,在浓度为50~400μg/ml范围内对A549细胞的增殖抑制呈现出良好的剂量依赖性关系,其IC50值为249.40μg/ml。结论 LGT-JQC配伍的醇提物对体外人小细胞肺癌A549细胞增殖的抑制具有协同增效作用,二者组成配比应在2/1~4/1,尤以在2/1作用为佳;LGT-JQC配比为2/1的醇提物,在浓度为50~400μg/m L对A549细胞的增殖抑制具有良好的量效关系。     

红霉素对聚甲基丙烯酸甲酯磨损颗粒刺激下MC3T3-E1细胞成骨作用的影响

目的 探讨红霉素对聚甲基丙烯酸甲酯(PMMA)磨损颗粒刺激下MC3T3-E1细胞成骨作用的影响及其潜在机制.方法 对MC3T3-E1细胞予以不同浓度(0.0μg/ml、0.2μg/ml、1.0μg/ml、5.0μg/ml和10.0μg/ml)的红霉素进行预处理,后加入PMMA磨损颗粒进行干预刺激,72 h后对MC3T3...     

多种药物对体外培养泡球蚴作用的观察

目的观察6种药物单独或联合用药对体外培养泡球蚴的作用。方法泡球蚴体外培养5周后,收集囊泡,随机分为17组,每组约120~140个囊泡,分别加入不同药物进行培养,①单独用药组:阿苯达唑组(1μg/ml、10μg/ml)、伊曲康唑组(0.7 mg/ml)、伊维菌素组(1.75 mg/ml)、米替福新组(0.5μg/ml、2.5μg/ml和7.5μg/ml)、硝唑尼特组(0.1μg/ml、1μg/ml和10μg/ml)、利福平组(10μg/ml);②联合用药组:硝唑尼特联合阿苯达唑10μg/ml+10μg/ml组、10μg/ml+1μg/ml组、1μg/ml+10μg/ml组和1μg/ml+1μg/ml组;③对照组:二甲基亚砜组(2μl/ml)和空白对照组。培养6周,观察囊泡塌陷情况,对囊泡进行计数,并绘制囊泡曲线。6周后停药,联合用药组连续观察3周、3个月和6个月,观察泡球蚴囊泡生长情况。将各药物组体外培养的泡球蚴接种于雌性BALB/c小鼠,饲养8周后处死并剖检观察小鼠腹腔内有无泡球蚴生长并称重,测试泡球蚴活力。结果伊维菌素、米替福新和利福平对泡球蚴无抑制或杀灭作用。阿苯达唑、伊曲康唑、硝唑尼特,及硝唑尼特与阿苯...     

隐球菌临床及环境分离株对卡泊芬净与特比萘芬的体外联合药敏试验

目的　了解隐球菌临床及环境分离株对卡泊芬净与特比萘芬的体外联合抗菌活性。方法　采用美国国家实验室标准委员会 (NCCLS)M 2 7 A方案推荐的酵母菌微量稀释法及其微量稀释棋盘法 ,检测 78株新生隐球菌临床和环境分离株对卡泊芬净与特比萘芬的体外抗菌活性及其联合抗菌活性。结果　卡泊芬净和特比萘芬对新生隐球菌最小抑菌浓度 (MIC)值范围分别是 0 .2 5～ 32 μg/ml、2～16 μg/ml;几何均数分别是 32 μg/ml、8μg/ml。联合药敏试验结果显示 ,两者联合后对其中 5 %菌株有协同作用 ,4 2 %菌株有累加作用及 5 3%菌株有无关作用 ,任何菌株均无拮抗作用。同时卡泊芬净的MIC几何均数由 2 6 .8μg/ml降至 2 0 .6 μg/ml(P <0 .0 0 0 1) ,特比萘芬的MIC几何均数由7.9μg/ml降至 1.3μg/ml(P <0 .0 0 0 1)。此外 ,有 4株菌株对卡泊芬净药物敏感 ,其MIC分别是 2 μg/ml、2 μg/ml、0 .5 μg/ml、0 .2 5 μg/ml。 结论　卡泊芬净与特比萘芬的体外联合药敏试验表明 ,两者联合应用对新生隐球菌具有较好的体外抗菌活性     

人型支原体共生与阴道毛滴虫甲硝唑耐药性的关系

目的研究人型支原体(Mycoplasma hominis)的共生与阴道毛滴虫(Trichomonas vaginalis)甲硝唑耐药性的关系。方法2010年11月至2011年7月,自四川省妇幼保健院妇科门诊患者生殖道分泌物中分离出160株阴道毛滴虫,用梯度浓度1 024、512、256……4、2和1μg/ml甲硝唑分别处理该批虫株,以死亡率≥90%的最低浓度作为甲硝唑最小致死浓度(MLC)。以160个阴道毛滴虫分离株中提取的DNA为模板,用PCR技术特异性扩增人型支原体16S rRNA基因,检测滴虫细胞内是否有人型支原体共生。对检出人型支原体DNA的分离株用32μg/ml多西环素清除支原体,比较清除前后甲硝唑MLC的变化。结果 160个阴道毛滴虫分离株中甲硝唑MLC为1～8μg/ml的占61.3%(98/160),16～32μg/ml的占26.3%(42/160),64～256μg/ml的占12.5%(20/160)。PCR检测结果显示,有61株(38.1%)检出人型支原体DNA,其中MLC为1～8μg/ml的分离株检出率为13.3%(13/98),16～32μg/ml的分离株检出率为73.8%(31/42),64～256μg/ml的分离株检出率为85.0%(17/20),不同MLC范围的分离株人型支原体检出率差异有统计学意义(P<0.01)。用多西环素处理后,61株中仅有8株支原体被清除,清除前后甲硝唑MLC无明显变化。结论四川地区的阴道毛滴虫分离株对甲硝唑表现出一定程度的耐药性,人型支原体的共生可能与之有关,但尚未发现直接证据。     

蛔虫抗菌肽酵母发酵产物对骨髓瘤细胞杀伤作用的效果观察

目的观察蛔虫抗菌肽酵母发酵产物对于骨髓瘤细胞杀伤作用的效果。方法培养骨髓瘤细胞至对数生长期,调整细胞浓度为(3～5)×105/ml,接种于96孔组织培养板中,100μl/孔,于37℃、5%CO2、饱和湿度条件下培养24h。设实验孔、空白对照孔和5-FU阳性对照孔。实验孔分别于10μl对数生长期骨髓瘤细胞中加入蛔虫抗菌肽酵母发酵产物浓缩上清液至终浓度分别为30、60、90、120、150、180μg/ml,每个浓度重复9孔,5-FU阳性对照孔终浓度为400μg/ml。连续培养24、48和72h后,采用MTT法检测各浓度蛔虫抗菌肽酵母发酵产物浓缩上清液对骨髓瘤细胞的杀伤效果。结果蛔虫抗菌肽酵母发酵产物对骨髓瘤细胞SP2/0有杀伤作用,发酵产物浓度为150μg/ml时,杀伤作用最大,杀伤率最大为78.845%,相当于400μg/ml的5-FU对骨髓瘤细胞SP2/0的杀伤作用。结论蛔虫抗菌肽酵母发酵产物对于骨髓瘤细胞具有杀伤作用。     

吡喹酮注射液在健康水牛体内的药物动力学

目的研究吡喹酮注射液在水牛体内的药物动力学特征及其与吡喹酮片之间的相对生物利用度。方法选用6头健康成年水牛,采用两周期随机交叉实验设计,单剂量内服吡喹酮片(20 mg/kg)或肌注吡喹酮注射液(10 mg/kg),高效液相色谱法(HPLC)测定水牛血浆中吡喹酮浓度,进行非房室模型分析,计算药动学参数。结果水牛内服吡喹酮片的峰时(T_(max))为(0.60±0.29)h,峰浓度(C_(max))为(0.57±0.37)μg/ml,消除半衰期(T_(1/2β))为(0.70±0.42)h,药-时曲线下面积(AUC)为(0.80±0.70)(μg/ml)·h。水牛肌注吡喹酮注射液的T_(max)为(0.65±0.49)h,C_(max)为(3.82±1.17)μg/ml,T_(1/2β)为(1.00±0.73)h,AUC为(1.61±0.89)(μg/ml)·h。吡喹酮注射液相对于吡喹酮片的生物利用度为402.5%。结论吡喹酮注射液肌注给药后在水牛体内具有吸收迅速,生物利用度高,体内分布广的药物动力学特征,临床推荐给药剂量为10 mg/kg。     

溴隐亭对垂体泌乳素腺瘤血管形成的影响及其分子作用机制研究

目的探讨溴隐亭对垂体泌乳素腺瘤血管形成的影响及其分子作用机制。方法 2014年1月—2015年6月,体外培养MMQ细胞株并进行MTT比色实验,共设置6个实验组、1个对照组和1个空白组,实验组在培养基和细胞悬液中添加不同浓度(0.125、0.250、0.500、1.000、2.000、4.000μg/ml)溴隐亭,分别记为0.125μg/ml组、0.250μg/ml组、0.500μg/ml组、1.000μg/ml组、2.000μg/ml组、4.000μg/ml组,对照组加入等体积的培养基及细胞悬液,空白组仅加入等体积的培养基;根据半数抑制浓度(IC50)筛选最适浓度溴隐亭进行后续试验。再采用最适浓度的溴隐亭处理MMQ细胞48 h,制备条件培养液(CM),各实验组在培养基和细胞悬液基础上分别加入最适溶度的溴隐亭和CM,对照组加入等体积的培养基和细胞悬液,采用酶联免疫吸附试验(ELISA)检测泌乳素(PRL)浓度及其变化率。用携带GFP基因的慢病毒(LV-GFP)感染人脐静脉血管内皮细胞(HUVEC)制备HUVEC/LV-GFP,用CM孵育HUVEC/LV-GFP细胞,各实验组在培养基和细胞悬液基础上分别加入最适浓度的溴隐亭和CM,CM组在培养基和细胞悬液基础上仅加入CM,1.000μg/ml组在培养基和细胞悬液基础上仅加入1.000μg/ml溴隐亭,对照组加入等体积培养基和细胞悬液;24 h后在荧光显微镜下观察血管样结构形成情况并计数。采用Western blotting法检测对照组与最适浓度溴隐亭组垂体瘤转化基因(PTTG)和血管内皮生长因子(VEGF)表达情况。结果 6个实验组MMQ细胞增殖抑制率时间与组间存在交互作用(P0.05);培养48 h、72 h 0.125μg/ml组、0.250μg/ml组、0.500μg/ml组、1.000μg/ml组、2.000μg/ml组、4.000μg/ml组MMQ细胞增殖抑制率高于培养24 h,培养72 h 0.125μg/ml组、0.250μg/ml组、0.500μg/ml组、1.000μg/ml组、2.000μg/ml组MMQ细胞增殖抑制率高于培养48 h(P0.05);而培养48 h与培养72 h 4.000μg/ml组MMQ细胞增殖抑制率比较,差异无统计学意义(P0.05)。通过软件计算抑制MMQ细胞增殖的IC50接近0.500μg/ml,遂选用0.250、0.500、1.000μg/ml溴隐亭进行后续实验。1.000μg/ml+CM组PRL浓度及变化率均低于0.500μg/ml+CM组、0.250μg/ml+CM组和对照组;0.500μg/ml+CM组PRL浓度及变化率均低于0.250μg/ml+CM组和对照组;0.250μg/ml+CM组PRL浓度及变化率均低于对照组(P0.05)。CM组MMQ细胞外血管样结构计数多于0.250μg/ml+CM组、0.500μg/ml+CM组、1.000μg/ml+CM组、1.000μg/ml组、对照组;0.250μg/ml+CM组MMQ细胞外血管样结构计数多于0.500μg/ml+CM组、1.000μg/ml+CM组、1.000μg/ml组、对照组;0.500μg/ml+CM组MMQ细胞外血管样结构计数多于1.000μg/ml+CM组、1.000μg/ml组、对照组;1.000μg/ml+CM组MMQ细胞外血管样结构计数多于1.000μg/ml组、对照组;1.000μg/ml组与对照组MMQ细胞外血管样结构计数比较,差异无统计学意义(P0.05)。对照组PTTG、VEGF表达水平高于0.250μg/ml组、0.500μg/ml组、1.000μg/ml组,0.250μg/ml组PTTG、VEGF表达水平高于0.500μg/ml组、1.000μg/ml组,0.500μg/ml组PTTG、VEGF表达水平高于1.000μg/ml组(P0.05)。结论溴隐亭可通过抑制垂体泌乳素腺瘤的血管形成而抑制其生长与侵袭,而这种抑制作用与下调PTTG/VEGF信号通路有关。     

中西药体外抑制幽门螺杆菌效果观察

目的探讨苦参、金银花、胃康和阿莫西林对幽门螺杆菌（Hp）的抑菌作用。方法取Hp标准菌株（SS1,NT2）菌液各1μl,分别接种于含不同浓度的苦参、金银花、胃康和阿莫西林血琼脂培养皿中,37℃培养72 h后观察最低抑菌浓度（MIC）。结果 4种药物对Hp SS1、NT2的MIC阿莫西林为16和32μg/ml,胃康均为1 000μg/ml,金银花为12 500和6 250μg/ml,苦参均〉25 000μg/ml。结论直接抑制和杀灭Hp效果西药优于中药。中西药联用可提高Hp根除率。     

Pioglitazone: an anti-diabetic compound with anti-aging properties

Insulin and Insulin-Growth-Factor-like (IGF) signaling pathways are well known longevity pathways in nematodes, insects and mammals. To our knowledge, there are no systematic pharmacological studies evaluating the anti-aging properties of medications that target this pathway in Drosophila. Although there are no published data implicating an anti-aging role for these compounds in Drosophila, we hypothesized that their promising pharmacological profile might decrease mortality. However, the decrease in mortality could be due to a number of potential artifacts and confounds such as fecundity depression, decrease in metabolic rate, or CNS depression. Therefore, the mere finding that a compound decreases mortality does not qualify it as an anti-aging compound. In this study, we evaluated the anti-aging properties of four compounds that might target the insulin signaling pathway in Drosophila. Once it was established that the compound decreased mortality, we proceeded to evaluate possible confounding factors that could have contributed to the mortality reduction. We show that only piolglitazone displayed anti-aging properties. At present, we do not have a mechanistic explanation for this pharmacological disparity.     

Anti-aging effects of anti-lipolytic drugs

Genetic disruption of insulin and insulin-like signaling pathways may extend lifespan. Hyperinsulinemia and insulin resistance may accelerate aging. The hypothesis was tested that a once-a-week life-long inhibition of insulin secretion by the administration of anti-lipolytic drugs might have anti-aging effects. Groups of 3-month-old male Sprague-Dawley rats were (a) given standard laboratory food ad libitum (AL); (b) fed AL 6 days and fasted 1 day every week (FW); (c) fed AL every other day (EOD), (d) fed like FW and given Acipimox (50 mg/kg b.w.) on the day of fasting (FWA) by the gastric tube. The AL, FW and EOD groups received saline intragastrically. Treatment with ACIPIMOX transiently decreased plasma free fatty acids, glucose and insulin and increased valine plasma levels, and had no long-term effect on food consumption and body weight. By age 6, 12 and 24 months subgroups were taken and the age-related changes in liver dolichol and autophagic proteolysis--which are correlated with life-expectancy--were measured. Liver dolichol levels increased and autophagic proteolysis decreased in mature and older AL rats; EOD and FWA fully counteracted these changes; FW rats had significant but smaller beneficial effects. It is concluded that life-long weekly-repeated transient inhibition of insulin secretion by antilipolytic drugs may have an anti-aging effect, additive to the anti-aging effect of a milder caloric restriction. Speculation is that transiently lower plasma insulin levels might stimulate the anti-aging cell-repair mechanism autophagy, which has longer lasting effects on cell housekeeping.     

Contentious terminology and complicated cartography of anti-aging medicine

Serving as an introduction to the cultural significance of the contemporary emergence of anti-aging medicine, this article outlines some of the distinctions and controversies regarding the usage of the term “anti-aging medicine.” By sketching out the complex field of researchers, practitioners, organizations, companies it is clear that “anti-aging medicine” is a highly contentious term that means different things to different groups. Thus, analysis demands a keen attention to contextualizing its usage. However, despite the critically important distinctions in how “anti-aging medicine” is used and what it connotes both to the user and the audience, the core principle of anti-aging is the notion that aging can be targeted for biomedical intervention. It is the orientation toward this explicit goal that marks anti-aging medicine. While neither advocating for/against anti-aging medicine nor excavating the large body of biological literature, this ethnographically researched article explicates the cultural use of “anti-aging medicine” and maps out its main varieties, controversies, stakes, and challenges.     

The war on "anti-aging medicine"

Leading members of the gerontological community have recently launched a war on anti-aging medicine, seeking to discredit what they judge to be fraudulent and harmful products and therapies, and to distinguish their research from what they regard as the pseudoscience of the anti-aging movement. This article interprets the contemporary war on anti-aging medicine as largely an attempt by established gerontological researchers to preserve their hard-won scientific and political legitimacy, as well as to maintain and enhance funding for research on the basic biological mechanisms of aging. First, it recounts the difficult struggle of U.S. biogerontologists to join the scientific mainstream in terms of legitimization and public funding. Second, it examines how elements of a contemporary anti-aging movement seem to threaten the hard-won public legitimacy of established gerontological researchers and practitioners. Third, it looks at the "boundary work" responses of the gerontological community to the anti-aging movement. Finally, it assesses the consequences of the war on anti-aging medicine to date.     

Interaction between a perfluorocarbon emulsion and radiographic contrast media

This study evaluated specially designed perfluorocarbon (PFC) emulsions as blood substitutes in case of induced ischemia of the left heart ventricle in healthy farm pigs. Two hundred ml of perfluorocarbon emulsion were infused while 200 ml of blood were simultaneously drawn. Radiographic contrast media were given to aid placement of balloon catheters in the left coronary artery. Histopathological analysis showed that right heart failure caused the deaths of both pigs. Particles (up to>3 micro) of foreign body materials obstructed capillaries of all organs analyzed (heart, lung, liver, kidneys and spleen). Laboratory investigation showed severe interference between the PFC emulsion and radiographic contrast media, resulting in the deterioration of the PFC emulsion. The strongest interference occurred when PFC emulsion and Accupaque interacted; particle size started at an initial 311 nm and went up to >3 micro within seconds. Great care must be taken when PFC emulsions are used in combination with x-ray contrast media. None of the described radiographic contrast media should be used within 48 hours prior to the use of this PFC emulsion. Also, the use of these contrast media should be avoided for a certain period of time after using PFC emulsion. The mechanisms of elimination of PFC emulsions from the circulation are not completely understood and has yet to be evaluated.     

抗衰1号对老年小鼠肝线粒体DNA缺失的影响

目的研究抗衰1号对老年Balb/c小鼠肝线粒体DNA(mtDNA)缺失突变的影响.方法老年Balb/c小鼠随机分为老年空白组和抗衰1号组,分别给予生理盐水和抗衰1号4个月.采用聚合酶链反应(PCR)技术和光密度扫描检测两组mtDNA的缺失情况.结果与老年空白对照组比较,抗衰1号能显著减少老年Balb/c小鼠mtDNA的缺失(P＜0.001). 结论抗衰1号可以抑制老年小鼠mtDNA的缺失,提示补肾健脾活血通腑法组方能减少mtDNA的氧化损伤,对mtDNA有保护作用,从而从分子水平提供了本法延缓衰老的可能机理.     

Effect of single versus multiple dosing on perfluorochemical distribution and elimination during partial liquid ventilation.

The objective of this study was to quantitate perfluorochemical (PFC) elimination kinetics during partial liquid ventilation (PLV) following an initial fill with or without hourly dosing. Young New Zealand rabbits were studied in two groups: Gr I (n = 6), PLV with a single dose of PFC liquid (perflubron: LiquiVent, Alliance Pharmaceutical Corp.); and Gr II (n = 5), PLV with PFC liquid and multiple hourly dosing . All rabbits were studied for 4 h, following initial instillation of a volume of PFC liquid equal to the measured gas functional residual capacity. Animals were ventilated at a constant breathing frequency (30 br/min), tidal volume (9.3+/-0.3 SE mL/kg), positive end expiratory pressure (4 cm H2O), and inspiratory time (0.30 s). PFC saturation of mixed expired gas (PFC-Sat) was assessed with a thermal conductivity analyzer, and PFC elimination was calculated from PFC-Sat, minute ventilation, and temperature of the expired gas. In GR II, PFC was supplemented hourly at a volume determined by PFC elimination calculations. The results demonstrated a decrease in PFC-sat and PFC loss with time, independent of group (P< 0.05). In addition, with hourly supplementation (GR II), PFC-Sat and PFC elimination over time was significantly (P < 0.05) greater than in animals (GR I) which did not receive additional doses. These data demonstrate that the PFC elimination rate is not constant and is related to the amount of PFC in the respiratory system. This may have occurred due to distributional differences of ventilation and PFC liquid between the single and multiple dosing groups. These findings also suggest that evaluation of PFC concentrations in expired gas may be a clinically useful index of intrapulmonary PFC distribution during PLV, and that maintained elevation of expired gas PFC saturation may guide optimal PFC dosing intervals and distribution to maximize protection against barotrauma.     

Social cognition in alcoholism: a link to prefrontal cortex dysfunction?

AIMS: Alcoholism is associated with a range of cognitive deficits. These deficits might be explained by the 'frontal lobe hypothesis' which suggests a specific vulnerability of the prefrontal cortex (PFC) to the neurotoxic effects of alcohol. Social cognition is thought to be processed in the PFC, but so far only few studies have addressed the issue of social cognition deficits in alcoholism. This review aims to evaluate the deficits in social cognition in alcoholic patients. In addition an outline for future perspectives is given. METHODS: Medline and Psyclit searches were performed for a 30-year period (1977-2007). RESULTS: Alcoholism is associated clearly with social cognition impairments which include emotional face and prosody perception problems, theory of mind deficits and humour processing difficulties. CONCLUSIONS: In summary, the social cognition impairments are consistent with the frontal lobe hypothesis of alcoholism. Future studies should focus on (i) the delineation of the basic cognitive processes which underlie social cognition deficits; and (ii) their relevance as predictors of treatment outcome in alcoholism.     

Perfluorochemical elimination from the lungs: effect of initial dose

Liquid-assisted ventilation with perfluorochemical (PFC) has been beneficial in a variety of respiratory diseases in animals and humans. Although PFC evaporation from the lungs is in part dependent on ventilation strategy and positioning, guidelines for initial and replacement dosing are unclear. We hypothesized that PFC evaporative loss over time is dependent on the size of the initial dose. Juvenile rabbits (n = 18) were ventilated using constant animal position and ventilator strategy. PFC (perflubron: LiquiVent ) was instilled endotracheally, using four groups with initial doses of 2, 6, 12, and 17 mL/kg. A previously described thermal detector that measures PFC in expired gas was used to calculate loss rate, residual perflubron in the lung, and volume loss as a % of initial fill volume. There was a significant dose, time, and dose-time interaction such that evaporative loss was dependent on initial PFC volume and time after fill (P < 0.05). Evaporative loss rate decreased earlier at lower doses. The percentage of initial volume lost to evaporation over time was inversely related to dose and could not be predicted by decreasing % PFC saturations, independent of dose. Evaporative loss should be considered to optimize both the application of PFC to the lung and replacement dosing during partial liquid ventilation.     

The efficacy and safety of health qigong for anti-aging: Protocol for a systematic review and meta-analysis

Background:Aging is a phenomenon that human''s physiology and psychology is progressive decline for natural environment. Health Qigong, as a convenient and effective exercise therapy,is widely used for anti-aging. However, there are no systematic reviews or meta-analysises to evaluate the efficacy and safety of Health Qigong on anti-aging.Methods:We will systematically search for 7 English databases(PubMed, Excerpta Medica Database, MEDLINE, Web of Science, Cochrane Library, SpringerLink, and WHO International Clinical Trials Registry Platform) and 4 Chinese databases(namely the China National Knowledge Infrastructure Database, the Wanfang Database, the Chinese Scientific Journal Database, and the Chinese BioMedical Literature Database) from their inceptions to August 2020. Randomized controlled trials (RCTs) using Health Qigong to anti-aging will be included. After the selection and extraction of eligible studies, a meta-analysis will be undertaken to assess the efficacy and safety of Health Qigong on anti-aging. Moreover, study selection, data extraction, and the evaluation of the methodological quality of trials will each be independently completed by at least 2 researchers. The Review Manager Software V.5.3 will be employed for meta-analysis to assess the risk of bias, data synthesis, and subgroup analysis.Results:This review will provide the latest knowledge and evidence on the efficacy and safety of Health Qigong for anti-aging through the analysis of various evaluation scales.Conclusion:The conclusion of this review will help clinicians provide effective exercise therapy for anti-aging.Registration number:INPLASY202090017