心肌自噬在异丙肾上腺素诱导心肌肥厚中的作用

目的 探讨心肌自噬在异丙肾上腺素（ISO）诱导大鼠心肌肥厚中的作用。方法 将 29只大鼠随机分为 3组：皮下联合腹腔注射生理盐水（Con）组 9只、腹腔注射生理盐水联合皮下注射异丙肾上腺（ISO）组 10只、腹腔注射雷帕霉素（RAP）联合皮下注射 ISO（ISO+RAP）组 10 只。连续干预 14 d 后,将 Con 组和 ISO 组存活大鼠（Con,n=9;ISO,n=8）行心脏超声检查左室壁厚度及左室射血分数（LVEF）,再将各组大鼠腹腔注射过量的 10%水合氯醛处死,摘除心脏,计算心脏体质量指数（HWI）。心肌组织病理切片行 HE染色和 Masson染色,Western blot检测 p62表达和LC3Ⅱ/Ⅰ比值,透射电镜观察心肌组织自噬泡数量。结果 与 Con组比较,ISO组左室壁厚度和 LVEF明显增加（P＜0.01）。与 Con组比较,ISO组和 ISO+RAP组的 HWI增大（P＜0.01）,且 ISO+RAP组的 HWI小于 ISO组（P＜0.01）。与Con组比较,ISO组心肌病理切片显示心肌组织病理性肥厚改变明显;而与 ISO组比较,ISO+RAP组心肌组织病理性肥厚明显改善。与 Con 组比较,ISO 组心肌组织 LC3Ⅱ/Ⅰ比值下调,而 p62 表达上调,自噬泡数量明显减少（P＜0.05）;与 ISO组比较,ISO+RAP组心肌组织 LC3Ⅱ/Ⅰ比值上调,而 p62表达下调,自噬泡数量明显增多（P＜0.01）。结论 上调心肌自噬活性可以逆转 ISO诱导的病理性心肌肥厚。     

Low-grade albuminuria is associated with peripheral artery disease in Chinese diabetic patients

Background

Increasing studies have suggested that albuminuria might be an important risk factor for peripheral artery disease (PAD). However, studies focusing on the association between low-grade albuminuria and PAD are limited. It would be of great interest to elucidate the association between low-grade albuminuria and PAD in diabetic subjects.

Methods

A cross-sectional study was conducted in 1386 diabetic subjects (age ≥ 40 years) with normal urinary albumin levels from Shanghai, China. A first voided early morning spot urine sample was obtained for urinary albumin and creatinine measurements. Subjects were divided into three groups according to sex-specific cutoff points of urinary albumin–creatinine ratio (UACR) tertiles. Subjects in the upper tertile of UACR were classified as having low-grade albuminuria. PAD was defined by ankle–brachial index (ABI) <0.9 or >1.4.

Results

Overall, 106 (7.7%) of the study population had PAD. The prevalence of PAD in tertile 3 of UACR was higher than the prevalence in tertile 2 and tertile 1 (10.2%, 6.4% and 6.4%, respectively; P < 0.05). A fully adjusted logistic regression analysis revealed that compared with subjects in tertile 1 of normal UACR, those in tertile 3 had 1.7-fold increased risk for the presence of PAD.

Conclusions

In diabetic patients, high normal UACR level, which is below the current cutoff point of microalbuminuria, was associated with the increased prevalence of PAD. It suggested that low-grade albuminuria might be an early marker for the detection of PAD in diabetic patients.     

肝硬化心肌病的CMR与USG研究进展

肝硬化心肌病(CCM)是肝硬化的严重并发症之一,主要表现为心肌对应激的收缩反应受损和/或舒张功能障碍及电生理功能异常。超声心动图(USG)目前广泛应用于CCM的诊断,但CCM发病机制复杂、血流动力学特殊,仅凭单一的USG技术很难完整揭示其结构、功能及心肌内部的改变。心脏磁共振(CMR)成像是目前公认的评估心脏功能的“金标准”,能多维度评价CCM心肌损伤。就USG、CMR技术在CCM心脏结构、功能、心肌纤维化评估及预后判断中的应用予以综述。     

Reversible cardiac dysfunction in severe COVID-19 infection,mechanisms and case report

A previously healthy 49-year-old male patient presented with COVID-19 infection and required mechanical ventilation and extracorporeal membrane oxygenation due to severe hypoxemia. Echocardiography showed cardiac dysfunction with an apical sparing strain pattern, which rapidly normalized within a week. Apical sparing myocardial strain in patients with COVID-19 infection may suggest reverse-type stress cardiomyopathy.     

Sibling concordance for clinical features of Duchenne and Becker muscular dystrophies

Introduction: The correlation of markers of disease severity among brothers with Duchenne or Becker muscular dystrophy has implications for clinical guidance and clinical trials. Methods: Sibling pairs with Duchenne or Becker muscular dystrophy (n = 60) were compared for ages when they reached clinical milestones of disease progression, including ceased ambulation, scoliosis of ≥ 20°, and development of cardiomyopathy. Results: The median age at which younger brothers reached each milestone, compared with their older brothers ranged from 25 months younger for development of cardiomyopathy to 2 months older for ceased ambulation. For each additional month of ambulation by the older brother, the hazard of ceased ambulation by the younger brother decreased by 4%. Conclusions: The ages when siblings reach clinical milestones of disease vary widely between siblings. However, the time to ceased ambulation for older brothers predicts the time to ceased ambulation for their younger brothers. Muscle Nerve 49 : 814–821, 2014