补骨脂素抗增生性瘢痕作用机制研究

目的探讨补骨脂素抗增生性瘢痕的作用机制。方法体外培养成纤维细胞,按随机数字表法分为正常组(培养正常成纤维细胞)、瘢痕组(培养增生性瘢痕成纤维细胞)、TGF-β1组(10 ng/ml TGF-β1处理增生性瘢痕成纤维细胞5 min^12 h)、Smurf2 RNA干扰组[Smad泛素化调节因子2(Smad ubiquitin regulatory factor2,Smurf2)siRNA转染增生性瘢痕成纤维细胞72 h]、补骨脂素组(10μmol/L补骨脂素处理增生性瘢痕成纤维细胞继续培养72 h)、补骨脂素+TGF-β1组(增生性瘢痕成纤维细胞加入补骨脂素培养72 h后加入TGF-β1培养6 h)。采用Western blot法检测Smurf2、α-平滑肌肌动蛋白(α-actin SMA,α-SMA)蛋白表达;RT-PCR法检测Ⅰ型胶原蛋白mRNA表达;ELISA法检测TGF-β1蛋白分泌。结果与正常组比较,瘢痕组Smurf2蛋白[(0.83±0.08)比(0.38±0.07)]表达增加(P<0.05);与瘢痕组比较,Smurf2 RNA干扰组TGF-β1[(2.2±0.18)比(4.2±0.47)]表达降低(P<0.05);TGF-β1组Smurf2[(0.71±0.06)比(0.42±0.04)]、α-SMA[(1.42±0.12)比(0.91±0.09)]蛋白表达增加(P<0.05),Ⅰ型胶原蛋白mRNA[(0.72±0.09)比(0.41±0.07)]表达增加(P<0.05);补骨脂素组Smurf2[(0.05±0.01)比(0.42±0.04)]、α-SMA[(0.71±0.07)比(0.91±0.09)]蛋白表达降低(P<0.05),Ⅰ型胶原蛋白mRNA表达[(0.12±0.04)比(0.41±0.07)]降低(P<0.05)。结论补骨脂素可能通过TGF-β1/Smurf2信号通路抑制α-SMA蛋白表达,从而降低Ⅰ型胶原蛋白表达,起到抑制瘢痕形成的作用。     

Entitlement: The big problem in medical education we will not talk about

Abstract

Entitlement is a problem in medical education that has received relatively little attention. First, it is felt by educators, who often feel pressured to conform curricula and evaluations to satisfy learner demands and administrative pressures lest their careers are penalized. Second, entitlement affects the medical system, as entitled physicians are less empathetic and focus more on personal goods rather than patient needs. This shifts the humanistic basis for medicine. Thirdly, entitlement is problematic for learners, as constant accommodations ironically undermine self-reliance and adaptability. Constantly meeting these demands can diminish gratitude and overall happiness. To address this issue, learners must acknowledge the problem and seek remedies to it themselves, as top-down interventions will likely be rebuffed. Rather than focusing solely on the learning environment, solutions should also empower learners to engage their environment in effective and productive ways. This should include correcting cognitive distortions that lead learners to expect administrative interventions in all circumstances perceived as harmful. Other solutions include practicing gratitude and developing work friendships. While certainly not all learners are entitled and some environmental amendments should be made, learners and educators must realize that entitlement is shaping medical culture and collectively take steps to mitigate its negative effects.     

Host–microbiome interactions: the aryl hydrocarbon receptor as a critical node in tryptophan metabolites to brain signaling

ABSTRACT

Tryptophan (Trp) is not only a nutrient enhancer but also has systemic effects. Trp metabolites signaling through the well-known aryl hydrocarbon receptor (AhR) constitute the interface of microbiome-gut-brain axis. However, the pathway through which Trp metabolites affect central nervous system (CNS) function have not been fully elucidated. AhR participates in a broad variety of physiological and pathological processes that also highly relevant to intestinal homeostasis and CNS diseases. Via the AhR-dependent mechanism, Trp metabolites connect bidirectional signaling between the gut microbiome and the brain, mediated via immune, metabolic, and neural (vagal) signaling mechanisms, with downstream effects on behavior and CNS function. These findings shed light on the complex Trp regulation of microbiome-gut-brain axis and add another facet to our understanding that dietary Trp is expected to be a promising noninvasive approach for alleviating systemic diseases.     

Double-balloon enteroscopy for retrieving retained small-bowel video capsule endoscopes: a systematic review

Abstract

Background and aim: Capsule retention is the most common adverse event associated with video capsule endoscopy. The use of double-balloon enteroscopy-assisted capsule endoscope retrieval has been increasingly reported in recent years. However, evidence is limited regarding its success rate, associated factors, and subsequent clinical outcomes.

Methods: A systematic review of relevant studies published before January 2019 was performed. Successful retrieval rate and associated factors, rate of endoscopic balloon dilation, and outcomes after double-balloon enteroscopy were summarized and pooled.

Results: Within 154 associated original articles, 12 including 150 cases of capsule retrieval by double-balloon enteroscopy were included. The estimated pooled successful retrieval rate was 86.5% (95% confidence interval, 75.6–95.1%). Anterograde approach and capsules retained in the jejunum or trapped by malignant strictures were associated with a higher successful retrieval rate than the retrograde approach (62/83 [74.7%] vs. 10/38 [26.3%], p?<?.001) and capsules retained in the ileum (41/41 [100.0%] vs. 43/58 [74.1%], p?<?.001) or trapped by benign strictures (21/21 [100.0%] vs. 65/83 [78.3%], p?=?.043). Endoscopic balloon dilation was performed in 38.8% (95% confidence interval, 22.3–56.3%) of patients with benign strictures. Two perforations (1.3%) were reported as severe adverse events after double-balloon enteroscopy. A significantly lower surgery rate was found among cases with successful video capsule removal compared with unsuccessful cases (7.2% vs. 38.5%, p?=?.002).

Conclusions: Double-balloon enteroscopy is feasible and safe for removing retained video capsule endoscopes, and its use could decrease the need for surgery in patients with benign strictures and facilitate subsequent surgery in patients with malignant strictures.     

1.318 μm近红外激光视网膜损伤阈值研究

目的研究1·318μm激光对视网膜的损伤效应,确定其损伤阈值。方法用输出波长1·318μm的Nd∶YAG激光为照射光源,固定照射时间0·2s,以不同剂量的激光照射散瞳后的家兔(25只)和大鼠(28只)眼睛,照射光斑直径分别为5mm和2mm,于照后1h和24h观察视网膜损伤发生率,用加权概率单位法计算损伤发生率为50%时所对应的激光剂量,即损伤阈值ED50。并于照后24h对损伤视网膜做病理切片观察。结果1·318μm激光致家兔和大鼠视网膜损伤的阈值角膜剂量分别为13·7J/cm2和10·4J/cm2,阈值角膜能量分别为2·69J和0·33J。受损视网膜可见清晰的白色凝固斑,损伤重者累及视网膜全层。结论1·318μm激光可导致家兔和大鼠视网膜损伤,损伤阈值ED50分别为13·7J/cm2和10·4J/cm2。     

非体外循环冠状动脉旁路移植术后造血干细胞动员的临床研究

目的研究非体外循环冠状动脉旁路移植术(OPCAB)后造血干细胞动员的规律及影响因素。方法对55例择期行OPCAB、近期无急性心肌梗死患者,分别于术前30m in、术后6、12、24、48、72和120h采外周静脉血4m l,CD 34和CD 45双抗标记、流式细胞仪检测造血干细胞计数,同时检测心肌酶谱及肌钙蛋白T的变化。结果冠心病患者术前造血干细胞计数占外周血有核细胞数计数的0.13%±0.12%,OPCAB后明显升高,24h达到峰值(0.34%±0.20%),术后120h回到术前基线水平;吸烟、高血脂、糖尿病对造血干细胞动员无明显影响,但合并高血压病患者外周血造血干细胞动员明显低于无高血压病患者;术后24h造血干细胞动员与肌酸激酶及肌酸激酶同工酶、乳酸脱氢酶、肌钙蛋白T呈正相关(r=0.692,P=0.000;r=0.558,P=0.000;r=0.447,P=0.000;r=0.401,P=0.004)。结论OPCAB术后造血干细胞快速、短暂动员,心肌损伤程度、冠心病危险因素参与了造血干细胞动员的调节。     

不同剂量帕米磷酸二钠治疗骨转移癌疼痛的疗效观察

目的观察不同剂量帕米磷酸二钠治疗骨转移癌引起疼痛的治疗效果。方法对66例确诊为骨转移癌的患者随机分为大剂量组和常规剂量组,大剂量组予静滴帕米磷酸二钠90mg;常规剂量组予静滴帕米磷酸二钠45mg,均为第1天和第2天连续给药。两组均每4周重复,共两次。结果大剂量组止痛效果及生活质量均优于常规剂量组。两组比较有显著性差异(P<0.01),两组均无严重不良反应。结论大剂量帕米磷酸二钠在止痛、改善患者生活质量方面明显优于常规剂量,且无严重不良反应,值得临床上进一步应用。