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A common challenge in pathogen discovery by deep sequencing approaches is to recognize viral or subviral pathogens in samples of diseased tissue that share no significant homology with a known pathogen. Here we report a homology-independent approach for discovering viroids, a distinct class of free circular RNA subviral pathogens that encode no protein and are known to infect plants only. Our approach involves analyzing the sequences of the total small RNAs of the infected plants obtained by deep sequencing with a unique computational algorithm, progressive filtering of overlapping small RNAs (PFOR). Viroid infection triggers production of viroid-derived overlapping siRNAs that cover the entire genome with high densities. PFOR retains viroid-specific siRNAs for genome assembly by progressively eliminating nonoverlapping small RNAs and those that overlap but cannot be assembled into a direct repeat RNA, which is synthesized from circular or multimeric repeated-sequence templates during viroid replication. We show that viroids from the two known families are readily identified and their full-length sequences assembled by PFOR from small RNAs sequenced from infected plants. PFOR analysis of a grapevine library further identified a viroid-like circular RNA 375 nt long that shared no significant sequence homology with known molecules and encoded active hammerhead ribozymes in RNAs of both plus and minus polarities, which presumably self-cleave to release monomer from multimeric replicative intermediates. A potential application of the homology-independent approach for viroid discovery in plant and animal species where RNA replication triggers the biogenesis of siRNAs is discussed.  相似文献   
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From 1981 to 1989, a total of 26 women with locally or regionally advanced carcinoma of the uterine cervix were treated with radiotherapy (RT) and pelvic regional hyperthermia (HT), in the Divisions of Radiation Oncology at the University of Utah Medical Center (UU) and the Kenneth Norris Jr Cancer Hospital of the University of Southern California (USC). HT was produced by the BSD-1000 HT system and the annular phased array (AA) applicator usually driven at 60-65 MHz, or the BSD-2000 HT system and the Sigma-60 (S60) applicator usually driven at 70-85 MHz. During the HT sessions acute toxicity was common, particularly because of pain within or outside the applicator, which was power-limiting in 43% of the patients overall. Pain was more easily manipulated, but more commonly power-limiting with the S60. Systemic stress was power-limiting in 22% of patients treated with the AA, but in no patients with the S60. Detailed thermal mapping and temperature analysis were performed on 26 patients. The mean overall average intratumour temperature achieved was 41 +/- 1.1 degrees C for 30 min; 5% and 35% of the monitored intratumour loci exceeded 43 degrees C and 42 degrees C, respectively. Temperatures recorded in the cervical os and proximal vagina appeared lower relative to the monitored normal structures in the region. Subacute treatment related toxicities occurred in five patients and included protracted pain (three) and superficial second degree burns (one), all of which resolved with supportive non-surgical therapy.  相似文献   
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Twenty-five patients with recurrent ventricular tachyarrhythmias underwent implantation of an automatic implantable cardioverter-defibrillator. The mean length of follow-up was 11.9 +/- 10.8 months. Before the implantation, the patients had survived one or more cardiac arrests (mean, 1.7; range, 1 to 4) and episodes of syncope (mean, 2.2; range, 2 to 3) and had received 6.0 +/- 1.0 antiarrhythmic drug trials. The in-hospital complications included death (two patients), reoperation (one patient), intraoperative myocardial infarction (one patient), sensing-failure (one patient), infection (five patients), and pocket seroma (two patients). The posthospital complications included device failure (four patients), device deactivation (one patient), and inappropriate discharge (two patients). The device discharged appropriately in seven patients due to sustained ventricular tachycardia. During electrophysiologic measurements, the energy requirement for successful cardioversion-defibrillation was related to the type of ventricular arrhythmia induced (monomorphic or pleomorphic ventricular tachycardia or fibrillation). Ventricular tachycardia acceleration occurred in ten patients (40%). No significant changes were found in the size of the electrograms or in the cardioversion threshold during early and late follow-up measurements. Life table analysis showed a 12-month survival rate of 86% and an arrhythmic death survival rate of 100%. We confirm the improved rate of survival in this high-risk group of patients, despite significant complications.  相似文献   
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INTRODUCTION: Recently catheter ablation has been accepted as standard therapy for symptomatic supraventricular tachycardia in children. Nature of childhood and the variability of congenital heart diseases and congenital heart surgery distinguishes pediatric catheter ablation from the adult practice. OBJECTIVES: The aim of the present study was to summarize a single-center experience of the first 30 consecutive patients regarding the electrophysiological studies and catheter ablations, moreover to report on the national adoption of these interventions for pediatric patients in Hungary. METHODS: Between April 1996 and September 2004 catheter ablation was offered for 30 children as treatment of their supraventricular tachycardia because of failure of pharmacological therapy or parents preference. RESULTS: The mean age of the patients was 13.7 years (2.3-18.0 years) and the mean weight was 52.0 kg (12.0-81 kg). Electrophysiology study revealed 33 arrhythmogenic substrates in 30 patients, 30 of those 33 were congenital while 3 were acquired. Catheter ablation was attempted in 27 patients with acute success in 24 cases (89%). Recurrence was observed in 2 patients and the redo ablation was effective in both, although a second recurrence occurred later in one of them. There were no major complications, but two minor ones (pseudoaneurysm of arteria femoralis, transient ventricular ectopy) occurred. CONCLUSIONS: Catheter ablation is safe and effective in children with congenital heart disease. Our results are comparable with the international data.  相似文献   
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Background: Statins are shown to have cholesterol‐independent properties such as anti‐inflammation and immunomodulation. Activated hepatic stellate cells (HSCs) acquire the capacity to synthesize matrix proteins in damaged liver. We tested the hypothesis that atorvastatin may be capable of inducing apoptosis in HSCs. Methods: Primary cultures of rat HSCs were exposed to atorvastatin, mevalonic acid and U0126. Quantification of living, apoptotic and necrotic HSCs was performed by flow cytometry and laser‐scan microscopy. Cell‐cycle analysis was performed by flow cytometry. Pro‐ and anti‐apoptotic factors were investigated by Western blot and electrophoresis mobility shift assay. Protease activity of caspases was calculated using a colorimetric kit. Results: Atorvastatin leads to a G2‐arrest and induces apoptosis in activated HSCs. Atorvastatin‐mediated apoptosis could be blocked by co‐administration of mevalonic acid and U0126. No effects of atorvastatin on gene expression of CD95, CD95L, NF‐κB, p53 and p21WAF1 could be observed. Atorvastatin‐induced apoptosis in activated HSCs is related to an increased protease activity of caspase‐9 and ‐3. Gene expression of the major proteins of the bcl‐system shows that truncated Bid is involved in apoptosis mediated by atorvastatin. By blocking the extracellular signal‐regulated protein kinase (ERK1/2) activation by adding U0126, we could prevent the apoptosis induced by atorvastatin. By Western blot we could not detect any change in the activation of c‐jun N‐terminal kinase (JNK). Conclusions: Atorvastatin induces apoptosis in activated HSCs acting through an ERK‐dependent cleavage of Bid and a highly increased protease activity of caspase‐9 and ‐3. JNK is not involved in atorvastatin‐mediated apoptosis in HSCs.  相似文献   
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