地塞米松缓释微粒在增生性玻璃体视网膜病变的应用

目的：观察含地塞米松（DEX）的缓释微粒治疗增生性玻璃体视网膜病变（PVR）的临床疗效。方法：9例（9只眼）视网膜脱离伴PVR患者进行常规玻璃体视网膜手术，并在玻璃体腔内植入1粒DEX微粒（含地塞米松1mg），观察术后反应及视力、PVR发展、DEX的位置及形状变化等。结果：术后炎症反应轻，7只眼视网膜复位，3只眼后极部视网膜前有增生；2只眼视网膜局限性脱离，最终3只眼玻璃腔内硅油填充。随访视力有8只眼较术前提高（P=0.015）。DEX未见对视网膜有不良影响，仅在随着处有少量色素吸附，4-6月后吸收。结论：DEX抑制PVR术后炎症反应及较远期作用是安全、有效的；对手术未完全清除的视网膜前增生有一定的抑制作用。     

Hemodynamic Parameters Influencing Clinical Performance of Novacor Left Ventricular Assist System

The interrelationships between hemodynamic variables including right ventricular (RV) performance with filling/ejection dynamics of the Novacor left ventricular assist system (LVAS) were determined in 10 of 11 patients who received LVAS as a bridge to heart transplant. Nine were successfully transplanted. Data were obtained intraoperatively, at periodic intervals up to 48 h postimplant and at explant. The hypotheses investigated included (a) RV performance influences LVAS filling characteristics and (b) LVAS pump output is influenced by systemic vascular resistance (SVR). During the period of LVAS support (2-126 days), pumping characteristics included a mean filling volume of 51 ml (range, 24-70), residual volume of 4.9 ml (range, 1-18), pump rate of 113/min (range, 63-175), and pump output of 5.81/min (range, 2.8-8.2). Multiple regression analysis identified pulmonary vascular resistance (PVR), RV stroke work index (RVSWI), and pulmonary capillary wedge pressure, but not RV ejection fraction, pulmonary artery pressure, or central venous pressure (CVP) as the most important correlates with LVAS filling volume (p less than 0.001, R2 = 0.6). In addition, LVAS pump output was influenced mainly by RVSWI, PVR, and SVR (p less than 0.001, R2 = 0.7). It was concluded that LVAS performance is highly dependent on RV function and systemic/pulmonary vascular resistances.     

Immunocytochemical Study of Cells in the Vitreous of Proliferative Virteoretretinopathy

Purpose: To identify the cellular components of vitreous samples obtained during vit-rectomy for proliferative vitreoretinopathy(PVR).Methods: With the use of three intermediate filament (IF) proteins, vimentin, glialfibrillary acidic protein (GFAP), and cytokeratin (CK), cytocentrifuge slides of 14fresh vitreous aspirates were detected with immunohistochemical technique.Results: All the specimens contained epithelial-like proliferative cells with or withoutpigment and some membrane-like pieces. Immunocytochemical staining showed that76.0-90.0% cells stained for CK, 17.4-29.6% cells expressed GFAP, and 80.1-91.0% cells were positive for vimentin.Conclusions : Majority of cells in the vitreous samples originated from retinal pigmentepithelial cells (RPE) and glial cells in PVR. Expression of IF proteins may be determinedby tissue of origin and local microenvironment. Eye Science 1999 ; 15; 13 - 16.     

水蛭素对兔增生性玻璃体视网膜病变闪光视网膜电图的影响

目的观察水蛭素对实验性增生性玻璃体视网膜病变(proliferative vitreoretinopathy,PVR)闪光视网膜电图(flash electroretinograme,F-ERG)b波的影响.方法将日本大耳白兔34只随机分为正常对照组、模型对照组、生理盐水组、高剂量和低剂量治疗组,各组分别分为短期组和长期组.采用眼穿通伤加注血法制备PVR模型,各治疗组在造模同时分别将生理盐水配制的高、低剂量水蛭素注入玻璃体腔.分别在3天和28天检测闪光视网膜电图b波波幅.结果与模型对照组比较,高、低剂量治疗组均能提高闪光视网膜电图b波波幅(P＜0.01),高剂量治疗组优于低剂量治疗组(P＜0.05).结论水蛭素能改善实验性PVR的视网膜功能,对视网膜有保护作用.     

增生性玻璃体视网膜病变的药物治疗研究进展

临床上对于增生性玻璃体视网膜病变(PVR)的治疗和预防主要是通过手术方法,有约1/3的病例由于视网膜表面细胞的再次增生最终失败,现提出联合药物手段控制PVR发展,由于PVR本质上是细胞的增生和收缩引起的病变,抑制细胞增生就成为药物治疗的关键,综述相关文献对实验室和临床上进行研究和应用的药物进行分述.     

The lowest VE/VCO2 ratio best identifies chronic thromboembolic pulmonary hypertension

Introduction

The natural history of acute pulmonary embolism (PE) under treatment is about a gradual resolution of the thrombi, and uncommonly, the development of chronic thromboembolic pulmonary hypertension (CTEPH). We hypothesized that ventilatory efficiency parameters during cardiopulmonary exercise testing (CPET) may be able to monitor the process and predict CTEPH.

Methods

15 patients rehabilitated from acute PE (total resolution of thrombi), 44 patients with chronic PE (with residual thrombi), 66 patients with CTEPH, and 36 sedentary healthy controls performed incremental CPET.

Results

The lowest VE/VCO₂ was higher in CTEPH patients than that in chronic PE and rehabilitated patients (43.4 L/min vs 29.9 L/min vs 27.1 L/min, p < 0.005). The VE/VCO₂ slope (48.4 L/min/L/min vs 29.9 L/min/L/min vs 28.0 L/min/L/min, p < 0.005) and oxygen uptake efficiency plateau (OUEP) (37.1 L/min vs 27.0 L/min vs 25.2 L/min, p < 0.005) had the similar changes. In logistic regression analysis, the lowest VE/VCO₂ ≥ 34.35 L/min was the best predictor of CTEPH (OR 159.0, 95% CI 36.0-702.3, p < 0.001). The lowest VE/VCO₂ was higher in chronic PE patients compared with the controls (29.9 L/min vs 26.5 L/min, p < 0.05), but there was no difference between the rehabilitated patients and the controls. In multiple linear regression analysis, the percentage of vascular obstruction by ventilation-perfusion lung scanning (PVO) was the most significant independent predictor for indices of ventilatory efficiency in chronic PE and rehabilitated patients.

Conclusions

CTEPH is associated with weakened ventilatory efficiency. The lowest VE/VCO2 ratio has the best capability to predict CTEPH. Ventilatory inefficiency improves along with recovery of acute PE.