Pharmacological inhibition of heparin-binding EGF-like growth factor promotes peritoneal angiogenesis in a peritoneal dialysis rat model

Background

Molecular mechanisms of peritoneal dialysis (PD) ultrafiltration failure, peritoneal neo-angiogenesis, and fibrosis remain to be determined. We aimed to determine the role of heparin-binding EGF-like growth factor (HB-EGF) inhibition on angiogenesis of peritoneal membrane in a PD rat model.

Methods

32 male Wistar rats were assigned into (1) control group; (2) uremic non-PD group: subtotal nephrectomy-induced uremic rats without PD; (3) uremic rats subjected to PD: uremic rats that were dialyzed with Dianeal^® for 4 weeks; (4) CRM 197 group: dialyzed uremic rats were supplemented with CRM197, a specific HB-EGF inhibitor. Peritoneal transport function was examined by peritoneal equilibration test. Expression of HB-EGF and EGFR in peritoneal samples were examined by real-time PCR, immunohistochemical staining, and western blot.

Results

Progressive angiogenesis and fibrosis were observed in uremic PD rats, and there were associated with decreased net ultrafiltration (nUF), increased permeability of peritoneal membrane, and reduced expression of HB-EGF and EGFR protein and mRNA in uremic PD rats compared to uremic non-PD or control groups (both p < 0.05). CRM197 significantly induced peritoneal membrane permeability, decreased nUF, increased higher vessel density, and reduced pericyte count compared to that of uremic PD rats. The levels of HB-EGF and EGFR expression negatively correlated with vessel density in peritoneal membrane (both p < 0.001).

Conclusion

PD therapy was associated with peritoneal angiogenesis, functional deterioration, and downregulation of HB-EGF/EGFR. Pharmacological inhibition of HB-EGF promoted PD-induced peritoneal angiogenesis and fibrosis and ultrafiltration decline, suggesting that HB-EGF downregulation contributes to peritoneal functional deterioration in the uremic PD rat model.

     

不同相对分子质量玻璃酸钠对膝关节镜术后关节功能恢复的作用比较

目的:观察关节腔内留置不同相对分子质量玻璃酸钠对膝关节镜术后早期疼痛及功能恢复的影响。方法:于2005-11/2006-05选择北京大学人民医院骨关节科收治的行膝关节镜手术患者60例。关节镜手术中根据不同诊断分别行半月板成形术、游离体取出术以及软骨成形术。60例患者按随机数字表法分为3个实验组,分别为Mr1.5×106～2.5×106玻璃酸钠组,Mr3×106玻璃酸钠组,Mr6×106玻璃酸钠组。术后关节腔内注入不同相对分子质量玻璃酸钠2.0～2.5mL,并被动屈伸膝关节20次,使玻璃酸钠均匀分布于关节内。术后第1天开始股四头肌力量锻炼,坐在床边屈膝活动,并可下床。术后1周拆除缝线,术后6周门诊复查。分别于术前、术后1,2,3d,1,6周采用同一评分量表进行自觉疼痛程度、日常生活活动能力、膝关节屈曲角度测评,评分越高,功能恢复越好。结果:纳入患者60例,均进入结果分析。①自觉疼痛程度测定:术后6周Mr1.5×106～2.5×106,3×106,6×106玻璃酸钠组自觉疼痛程度评分均高于术前[分别为(8.5±1.3),(7.3±2.2)分;(8.5±1.3),(7.3±2.2)分;(8.5±1.3),(7.3±2.2)分]。②日常生活活动能力测定:术后6周Mr1.5×106～2.5×106,3×106,6×106玻璃酸钠组日常生活活动能力评分均高于术前[分别为(60.5±8.4),(59.3±7.0)分;(63.4±8.2),(59.4±8.3)分;(66.9±3.8),(53.8±19.0)分]。③膝关节屈曲角度评分:术后6周Mr1.5×106～2.5×106,3×106,6×106玻璃酸钠组膝关节屈曲角度评分均高于术前[分别为(9.1±1.4),(5.8±2.7)分;(8.1±3.1),(7.2±3.5)分;(6.3±3.8),(5.5±3.1)分]。④综合评分:术后6周Mr1.5×106～2.5×106,3×106,6×106玻璃酸钠组综合评分均高于术前[分别为(88.1±7.7),(79.8±11.1)分;(91.4±6.8),(84.9±13.7)分;(91.2±10.7),(73.5±23.7)分]。关节腔内留置3种不同相对分子质量玻璃酸钠在膝关节镜术后近期各项评分差异均无显著性意义(P>0.05)。结论:关节腔内留置不同相对分子质量玻璃酸钠在膝关节镜术后近期康复中具有相似的效果。     

Genistein对去卵巢后大鼠基底前脑神经元一氧化氮合酶表达及认知功能的影响

目的:观察去卵巢大鼠植物雌激素替代治疗后基底前脑一氧化氮合酶阳性神经元的表达和其认知功能在去卵巢后的时程变化。方法:实验于2004-07/2005-07在南通大学基础医学院人体解剖学教研室完成。3月龄雌性大鼠48只随机抽签法分为假手术组、去势组、Genistein替代组和雌激素替代组,每组12只。卵巢切除前,各组大鼠行避暗回避实验行为学检测。各组大鼠的处理:①去势组:切除双侧卵巢。②Genistein替代组:切除双侧卵巢后进行Genistein替代,剂量100μg(溶于200μLDMSO)。③雌激素替代组:切除双侧卵巢后进行雌激素替代,皮下注射苯甲酸雌二醇,剂量10μg(溶于100μL无菌芝麻油)。④假手术组:只切开双侧腰肌不触及卵巢,随即缝合伤口,相同条件下存活4周。药物注射隔日1次,时间固定,持续4周,分别于最后1次注射24h后进行灌注固定。各组大鼠在灌注前1周进行避暗回避实验。脑切片用NADPH-d组织化学方法染色,观察基底前脑内侧隔核、斜角带核垂直支脑区一氧化氮合酶阳性神经元的分布,并进行计数和统计分析。结果:实验过程中无动物死亡,全部进入结果分析。①去势前各组大鼠避暗回避实验的探索次数和滞留时间差异无显著性(P均>0.05);去势后行替代治疗1,2周后,各组大鼠避暗回避实验的探索次数和滞留时间差异无显著性(P均>0.05);替代治疗4周后,Genistein替代组和雌激素替代组大鼠的探索次数比去势组明显减少,滞留时间比去势组明显延长(P<0.05)。②大鼠基底前脑一氧化氮合酶阳性神经元染色为深蓝色,胞体边界清晰,突起明显,为双极或多极细胞。内侧隔核的一氧化氮合酶阳性细胞主要分布于中线两侧,呈倒“V”字形排列,体积较小,胞体多呈梭形,各组大鼠的神经元数目在术后各时间点的差异不明显。在斜角带核垂直支则呈“人”字形排列,胞体较内侧隔核大,多呈锥形或椭圆形,多为多极神经元。各组大鼠神经元的数目呈动态变化,Genistein或雌激素替代组一氧化氮合酶阳性神经元数目上升,而去势组减少,替代治疗后1,2周内,Genistein或雌激素替代组与去势组之间差异无显著性(P>0.05);第4周时Genistein或雌激素替代组一氧化氮合酶阳性神经元的数目接近于假手术组水平,与去势组间差异有显著性(P<0.01)。结论:去卵巢后行替代治疗能增加大鼠基底前脑一氧化氮合酶阳性神经元的表达,改善大鼠认知功能,可能对中枢神经系统退行性病变起保护作用。     

Estimation of the cortical functional connectivity with the multimodal integration of high-resolution EEG and fMRI data by directed transfer function

Nowadays, several types of brain imaging device are available to provide images of the functional activity of the cerebral cortex based on hemodynamic, metabolic, or electromagnetic measurements. However, static images of brain regions activated during particular tasks do not convey the information of how these regions communicate with each other. In this study, advanced methods for the estimation of cortical connectivity from combined high-resolution electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data are presented. These methods include a subject's multicompartment head model (scalp, skull, dura mater, cortex) constructed from individual magnetic resonance images, multidipole source model, and regularized linear inverse source estimates of cortical current density. Determination of the priors in the resolution of the linear inverse problem was performed with the use of information from the hemodynamic responses of the cortical areas as revealed by block-designed (strength of activated voxels) fMRI. We estimate functional cortical connectivity by computing the directed transfer function (DTF) on the estimated cortical current density waveforms in regions of interest (ROIs) on the modeled cortical mantle. The proposed method was able to unveil the direction of the information flow between the cortical regions of interest, as it is directional in nature. Furthermore, this method allows to detect changes in the time course of information flow between cortical regions in different frequency bands. The reliability of these techniques was further demonstrated by elaboration of high-resolution EEG and fMRI signals collected during visually triggered finger movements in four healthy subjects. Connectivity patterns estimated for this task reveal an involvement of right parietal and bilateral premotor and prefrontal cortical areas. This cortical region involvement resembles that revealed in previous studies where visually triggered finger movements were analyzed with the use of separate EEG or fMRI measurements.     

图片展示沟通技巧的临床应用

目的运用图片展示与暂时性失语患者进行沟通.方法通过对50例因疾病、上呼吸机或因手术治疗行气管切开但意识清醒的暂时性失语患者给予三方面支持,即情感支持、信息支持及医疗补偿性支持.结果通过应用图片展示辅以手势、体语来完成护患沟通,满足暂时性失语后患者的身心需求.结论本方法行之有效,对提高患者生活质量,增强护患关系有着十分重要的意义.     

Effects of Efflux Pump Inhibitors on Colistin Resistance in Multidrug-Resistant Gram-Negative Bacteria

We tested the effects of various putative efflux pump inhibitors on colistin resistance in multidrug-resistant Gram-negative bacteria. Addition of 10 mg/liter cyanide 3-chlorophenylhydrazone (CCCP) to the test medium could significantly decrease the MICs of colistin-resistant strains. Time-kill assays showed CCCP could reverse colistin resistance and inhibit the regrowth of the resistant subpopulation, especially in Acinetobacter baumannii and Stenotrophomonas maltophilia. These results suggest colistin resistance in Gram-negative bacteria can be suppressed and reversed by CCCP.     

Overcoming Chloroquine Resistance in Malaria: Design,Synthesis, and Structure-Activity Relationships of Novel Hybrid Compounds

Resistance to antimalarial therapies, including artemisinin, has emerged as a significant challenge. Reversal of acquired resistance can be achieved using agents that resensitize resistant parasites to a previously efficacious therapy. Building on our initial work describing novel chemoreversal agents (CRAs) that resensitize resistant parasites to chloroquine (CQ), we herein report new hybrid single agents as an innovative strategy in the battle against resistant malaria. Synthetically linking a CRA scaffold to chloroquine produces hybrid compounds with restored potency toward a range of resistant malaria parasites. A preferred compound, compound 35, showed broad activity and good potency against seven strains resistant to chloroquine and artemisinin. Assessment of aqueous solubility, membrane permeability, and in vitro toxicity in a hepatocyte line and a cardiomyocyte line indicates that compound 35 has a good therapeutic window and favorable drug-like properties. This study provides initial support for CQ-CRA hybrid compounds as a potential treatment for resistant malaria.