新生大鼠缺氧缺血后不同脑区神经元变性的动态观察

目的：观察新生大鼠缺氧缺血（HI）后不同脑区神经元变性的动态变化,探讨其与星形胶质细胞反应的关系。方法：采用Fluoro-Jade B（FJB）染色法及免疫组化法分别观察变性神经元荧光染色强度及胶质纤维酸性蛋白（GFAP）表达的动态变化。结果：正常新生大鼠各脑区内均未见FJB阳性细胞,GFAP呈弱表达。HI后1d即可见FJB阳性细胞,3d阳性细胞增多,5d达高峰,以纹状体受累最重,皮质次之,海马各区易损顺序为CA1、CA4、CA2、CA3、齿状回。GFAP表达的强度与FJB阳性细胞数密切相关。结论：新生大鼠HI后脑易损部位为纹状体、皮质、海马,FJB染色是一种标记变性神经元的有效方法,反应性胶质细胞增生是应答神经元损伤的结果。     

Role of Pulmonary Veins Isolation in Persistent Atrial Fibrillation Ablation:

Background: The role of pulmonary veins (PV) isolation in patients with persistent atrial fibrillation (AF) is still debated. The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation (anatomical approach).
Methods: We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach (group A, n = 36, mean age = 60 ± 8 years, 29 males) or an integrated approach (group B, n = 61, mean age 59 ± 10 years, 48 males). In all patients, radiofrequency (RF) ablation was performed by means of a nonfluoroscopic navigation system, in order to anatomically create circumferential lines around the PV. In group B, the persistence of PV potentials was ascertained with a multipolar circular catheter. If PV potentials persisted, RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV. Past a 2-month period of observation, success was defined as absence of any atrial tachyarrhythmia recurrence lasting >30 seconds.
Results: Total procedure duration (220 ± 62 minutes vs 140 ± 43 minutes, P < 0.001), fluoroscopy time (35 ± 15 minutes vs 17 ± 9 minutes, P < 0.001), and RF delivery time (48 ± 22 minutes vs 27 ± 9 minutes, P < 0.001) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 ± 9.1 months, 21 patients in group A (58%) and 34 patients in group B (56%) were free of atrial tachyarrhythmia recurrence (P = 0.9).
Conclusions: In patients with persistent AF, who underwent an anatomical approach, electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times, without effect on the long-term outcomes.     

Left Ventricular Functional Recovery During Cardiac Resynchronization Therapy:

Cardiac resynchronization therapy (CRT) improves myocardial performance in patients with heart failure (HF) and left bundle-branch block (LBBB). Tissue Doppler echocardiography (TDE) has already been used to guide the selection of candidates for CRT. The objective of this study is to correlate the effects of CRT on left ventricular (LV) systolic function with wall motion synchrony assessed by TDE. High frame TDE data were obtained in 15 patients (mean age = 68.9 years, 11 men) with LBBB (QRS = 163 ± 13 ms) to derive temporal intraventricular horizontal asynchrony indexes, expressed as the time difference at the onset of shortening between the septum and the lateral (S-L) and antero-inferior (A-I) walls, and measure the amount of delayed longitudinal contraction (DLC) within the LV. All measurements were made at baseline, 24 hours after implantation, and at 1 year of follow-up. The results show that LV ejection fraction (EF) increased from 25 ± 6.2% at baseline to 36.9 ± 7.9% at 1 year, and was strongly related to DLC, expressed either by time duration (DLCd, r =−0.51; P < 0.0001) or percent of the basal segments (%DLC, r =−0.50; P < 0.001). New York Heart Association functional class, which decreased from 3.6 ± 0.5 to 2.3 ± 0.8, was correlated with %DLC (r = 0.50) and DLCd (r = 0.48, P < 0.001). Weaker correlations were found between LVEF and S-Li (r =−0.40) and between NYHA and S-Li (r = 0.40). It is concluded that DLC was the best among intraventricular asynchrony indexes in predicting increases in LVEF after CRT. DLC may be useful to identify responders to CRT.     

Features of Regression in Dermoscopic Diagnosis: A Confounding Factor? Two Clinical, Dermoscopic-Pathologic Case Studies

BACKGROUND: In dermoscopy, the presence of regression areas is generally associated with melanocytic lesions and is often considered a clue of malignancy. However, some lesions included in the differential diagnosis of melanoma may show dermoscopic regression parameters. Regression may indeed be one of the most confounding dermoscopic parameters because it tends to cover, or rather to destroy, other parameters, thus often hindering a correct diagnosis. OBJECTIVE: We propose to raise the issue of the actual diagnostic role of this parameter. METHODS: We discuss two clinical cases (melanoma and basal cell carcinoma) with major dermoscopic regression features. CONCLUSION: Dermoscopic regression parameters should not be regarded as almost pathognomonic signs of melanocytic lesions. Rather, they should be taken into account only after having considered other dermoscopic parameters of greater diagnostic significance and just as signs that may better typify the lesion.     

Antiarrhythmic Drug Therapy after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation

Objectives: The use of antiarrhythmic drugs after ablation is a controversial issue when evaluating the efficacy of atrial fibrillation (AF) ablation. This study compares in a prospective and randomized fashion the impact of an antiarrhythmic drug in preventing AF recurrence after AF ablation.
Methods: From February 2004 to May 2005, 107 consecutive patients (mean age 57 ± 10 years, 69 men), with paroxysmal (60%) or persistent (40%) drug refractory AF, were randomly assigned to ablation alone (Group A, 53 patients) or combined with the best antiarrhythmic therapy, preferably amiodarone (Group B, 54 patients). All patients underwent cavo-tricuspid and left inferior pulmonary vein (PV)-mitral isthmus ablation plus circumferential PV ablation, using a guided electro-anatomical approach. Standard electrocardiograms (ECG), and ambulatory and transtelephonic ECG monitoring were used to assess AF recurrences. Recurrences during the first month after ablation were excluded from this analysis.
Results: At 12 months of follow-up, no significant difference was observed in the rates of AF recurrences between Group A (18/53 patients, 34%) and Group B (16/54 patients, 30%). The percentage of patients with ≥1 asymptomatic AF episode was higher in Group B than in Group A (10/16 patients, 63%, vs 5/18 patients, 28%, P = 0.04).
Conclusions: Continuing antiarrhythmic drug therapy in patients who undergo catheter ablation for AF did not lower the rate of AF recurrences. Antiarrhythmic drugs increased the proportion of patients with asymptomatic AF episodes.     

Influence of Different Materials in Multicomponent Bandages on Pressure and Stiffness of the Final Bandage

BACKGROUND The physical characteristics of bandage kits, in which different materials are combined, cannot be predicted by laboratory tests. They can only be assessed in vivo by measuring the interface pressure and calculation of stiffness.
OBJECTIVE The objective was to investigate pressure and stiffness of some widely used multicomponent, multilayer bandages and to investigate the effect of modifications of their components.
METHODS AND MATERIALS Twelve healthy volunteers were investigated. Interface pressure and stiffness were measured in the lying and standing position after application of four-layer elastic bandage (Profore, Smith & Nephew, Hull, UK), two-layer elastic bandage (Proguide, Smith & Nephew), and four-layer short-stretch bandage (Rosidal sys, Lohmann & Rauscher GmbH, Neuwied, Germany) applied according to the manufacturer's recommendations and after some modifications of the padding layer.
RESULTS Both Profore, made up of elastic, and Rosidal sys, made up of inelastic components, fulfill the criteria for bandages with high stiffness. The stiffness of Proguide, consisting of elastic components, is in a gray zone between elastic and inelastic materials. Altering the padding layers changes the stiffness of these bandages completely.
CONCLUSION Pressure and stiffness of composite bandage kits differ from the physical properties of their components. Modifying the padding layers leads to a change of these physical properties that can only be assessed by in vivo tests on the human leg.