Mediastinitis after coronary artery bypass grafting: the effect of vacuum‐assisted closure versus traditional closed drainage on survival and re‐infection rate

Mediastinitis is treated with either vacuum‐assisted closure (VAC) or traditional closed drainage (TCD) with irrigation. The aim of the study was to determine the effect of the two treatments on mortality and re‐infection rate in a source population, using 21 314 consecutive patients undergoing isolated coronary artery bypass grafting (CABG) from January 1997 to October 2010. Median observation time was 2·9 years in the VAC group and 8·0 years in the TCD group. The epidemiological design was of an exposed (VAC, n = 64) versus non‐exposed (TCD, n = 66) cohort with two endpoints: (1) mortality and (2) failure of sternal wound healing or re‐infection. The crude effect of treatment technique versus endpoint was estimated by univariate analysis. Stratification analysis by the Mantel–Haenszel method was performed to quantify confounders and to pinpoint effect modifiers. Adjustment for confounders was performed using Cox regression analysis. Mediastinitis was diagnosed 6–105 (median 14) days after primary operation in the VAC group and 13 (5–29) days in the TCD group. There was no difference between groups in long‐term survival. Failure of sternal wound healing or re‐infection occurred less frequently in the VAC group (6%) than in the TCD group (21%; relative risk = 0·29, 95% CI = 0·06–0·88, P = 0·01). There are concerns for increase in right ventricle rupture in VAC compared with TCD. There was no difference in survival after VAC therapy and TCD therapy of post‐CABG mediastinitis. Failure of sternal wound healing or re‐infection was more common after TCD therapy.     

人参须根中皂苷类成分提取工艺的研究

目的:研究人参须根中皂苷类成分的最佳提取工艺。方法:比较了乙醇回流提取法和超声波提取法提取人参皂苷的差异。在此实验基础上,通过单因素实验和正交实验,筛选出超声波法从人参须根中提取皂苷类成分的最优提取工艺。结果:人参须根中皂苷类成分的最优提取条件为50%乙醇,提取2次,每次40min,提取温度40℃,料液比为1:20。结论:该提取方法操作简单,有效成分的提取率高。     

From expert-derived user needs to user-perceived ease of use and usefulness: A two-phase mixed-methods evaluation framework

Underspecified user needs and frequent lack of a gold standard reference are typical barriers to technology evaluation. To address this problem, this paper presents a two-phase evaluation framework involving usability experts (phase 1) and end-users (phase 2). In phase 1, a cross-system functionality alignment between expert-derived user needs and system functions was performed to inform the choice of “the best available” comparison system to enable a cognitive walkthrough in phase 1 and a comparative effectiveness evaluation in phase 2. During phase 2, five quantitative and qualitative evaluation methods are mixed to assess usability: time-motion analysis, software log, questionnaires – System Usability Scale and the Unified Theory of Acceptance of Use of Technology, think-aloud protocols, and unstructured interviews. Each method contributes data for a unique measure (e.g., time motion analysis contributes task-completion-time; software log contributes action transition frequency). The measures are triangulated to yield complementary insights regarding user-perceived ease-of-use, functionality integration, anxiety during use, and workflow impact. To illustrate its use, we applied this framework in a formative evaluation of a software called Integrated Model for Patient Care and Clinical Trials (IMPACT). We conclude that this mixed-methods evaluation framework enables an integrated assessment of user needs satisfaction and user-perceived usefulness and usability of a novel design. This evaluation framework effectively bridges the gap between co-evolving user needs and technology designs during iterative prototyping and is particularly useful when it is difficult for users to articulate their needs for technology support due to the lack of a baseline.     

人参皂甙Rg3对糖尿病肾病大鼠肾组织Bax和B淋巴细胞瘤-2蛋白表达及肾细胞凋亡的影响

目的探讨糖尿病肾病(diabetic nephropathy,DN)大鼠应用人参皂甙Rg3处理后肾组织Bax、B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)蛋白表达变化及肾细胞凋亡情况。方法120只雄性SD大鼠,随机分为模型组、治疗组和对照组各40只。模型组、治疗组腹腔注射质量分数2%链尿佐菌素溶液制备DN模型,对照组腹腔注射等量生理盐水。造模成功后,治疗组将0.5 mg/kg人参皂甙Rg3与生理盐水混合溶液灌胃,模型组、对照组大鼠给予等量生理盐水灌胃,均1次/d,连续28 d。疗程结束后大鼠麻醉处死,取肾组织行病理检查,采用TUNEL法检测肾组织细胞凋亡,Western blot法检测肾组织Bax、Bcl-2蛋白相对表达量,实时荧光定量PCR法检测肾组织Bax mRNA、Bcl-2 mRNA相对表达量。结果对照组大鼠肾组织系膜结构、肾小管均正常,小管膜完整光滑,间质未增生;模型组大鼠肾组织系膜结构异常,间质严重增生,肾小管萎缩严重,小管膜粗糙;与模型组比较,治疗组大鼠肾组织系膜细胞增生减轻,肾小管萎缩减少,纤维组织减少;模型组、治疗组、对照组大鼠肾细胞凋亡率[(0.91±0.23)%、(0.56±0.14)%、(0.21±0.03)%]依次降低(P<0.05);模型组、治疗组、对照组肾组织Bax蛋白相对表达量(1.79±0.31、2.73±0.24、3.26±0.12)、Bcl-2蛋白相对表达量(1.42±0.12、2.59±0.25、4.40±0.31)、Bax mRNA相对表达量(0.35±0.02、1.45±0.91、3.12±1.17)、Bcl-2 mRNA相对表达量(1.34±0.87、1.73±0.67、3.91±0.75)依次增高(P<0.05)。结论人参皂甙Rg3对DN大鼠有显著治疗作用,可明显改善大鼠肾组织形态,降低肾细胞凋亡率,上调Bax、Bcl-2表达。     

人参皂苷Rg1抑制PGF_(2α)诱导心肌细胞肥大

目的观察人参皂苷Rg1(ginsenoside Rg1,Rg1)对前列腺素F2α(prostaglandin F2α,PGF2α)所致心肌肥大的影响。方法利用培养的新生大鼠心肌细胞,以细胞直径、蛋白含量?心房利钠因子(atrial natriuretic factor,ANF)mRNA的表达为心肌肥大标志,观察药物的抗心肌肥大效应。AN-FmRNA的表达用Real-time PCR检测;用Fura-2/AM负载的培养心肌细胞检测细胞内游离钙浓度([Ca2+]i);一氧化氮试剂盒测定细胞上清液中一氧化氮(nitric oxide,NO)代谢物的含量,以探讨Rg1可能的作用机制。结果PGF2α0.1μmol·L-1使心肌细胞直径明显增大,蛋白质含量明显增加,ANF mRNA的表达增强,并使[Ca2+]i明显升高。Rg115.6、31.2和62.4μmol·L-1使经PGF2α处理的心肌细胞的直径分别缩短18.4%、32.7%和43.8%;使心肌细胞蛋白含量分别减少8.2%、14.6%和17.7%;Rg1 62.4μmol·L-1还使ANF mRNA的表达降低;Rg1 15.6、31.2和62.4μmol·L-1呈剂量依赖地抑制PGF2α所致的[Ca2+]i升高;NO前体L-精氨酸(L-arg)1 mmol.L-1具有相似的作用。此外,NO合酶抑制剂L-NAME可取消L-arg的作用,并部分抑制Rg1的效应;Rg1还明显升高心肌细胞上清液NO代谢物的含量。结论Rg1可抑制PGF2α诱导的心肌细胞肥大,该作用可能与其促进心肌细胞NO的释放,降低由PGF2α所升高的心肌细胞[Ca2+]i有关。     

RP—HPLC测定人参各部位人参皂苷compound K的含量

目的:考察人参皂苷 compound K 是否存在于人参植物体中并测定其含量。方法:采用氯仿-甲醇(15∶1)超声提取,并用 Zorbax SB C_(18)色谱柱(4.6 mm×150 mm,5μm),以乙腈和水作为流动相进行二元梯度洗脱,流速为0.8 mL·min~(-1),检测波长为203 nm。结果:人参花和人参果中人参皂苷 compound K 的含量分别为0.02%和0.04%。人参皂苷 compound K 在0.523～10.45μg范围内呈良好的线性关系(r=0.9996),平均回收率为97.55%。在人参茎叶、鲜人参主根、红参芦头、红参主根、红参须根中未检出人参皂苷 compound K。结论:在人参植物体中存在人参皂苷 compound K。本方法简便、灵敏和准确,可作为人参皂苷 compound K 的有效分析方法。     

HPLC法测定双参龙胶囊中人参皂苷Rb1的含量

目的:建立双参龙胶囊中人参皂苷 Rb_1含量测定的高效液相色谱法。方法:采用 Kromasil C_(18)柱(KR100-5C_(18),4.6 mm×250 mm,5μm),乙腈-水(28.7:71.3)为流动相;流速为1.0 mL·min~(-1);检测波长为203 nm。结果:人参皂苷 Rb_1在0.848～4.24μg范围内,线性关系良好(r=0.9991),方法平均回收率为99.3%,RSD=1.2%(n=6)。结论:方法简便,结果准确,可用于双参龙胶囊中人参皂苷 Rb_1的定量。     

初均速法预测人参茎叶皂苷的稳定性

目的采用了初均速法,研究不同温度下人参茎叶皂苷药物中人参皂苷Re含量变化情况,HPLC方法测定其含量,预测药物的有效期。方法以反应初始速度Vo代替反应速度常数K,按Arrhenius规律,选择60,65,70,75,80,85,90℃,放置设计时间,考察人参茎叶皂苷的稳定性。结果lgVo对1/(T×10-3)进行回归分析得回归方程,logVoi=12.4327-4.2633×1/(T×10-3),(r=0.996)。通过回归方程计算t2950%℃(T=298)为11058.7 h≈460.78 d≈1.26年。结论用初均速法预测人参茎叶皂苷的稳定性,以测定人参皂苷Re含量为指标,其操作简便,结果可靠。所以该药物在储存时应避高温,用室温保存,以保证药物的质量。