Transvenous Lead Extraction (TLE) Procedure: Experience from a Tertiary Care Center in Thailand

BackgroundTransvenous Lead Extraction (TLE) is a standard treatment for some late Cardiac Implantable Electronics Device (CIED) complications. The outcome of transvenous lead extraction procedure in Thailand is not robust.MethodsA Single-center retrospective cohort of TLE procedures performed at Ramathibodi hospital between January 2008 and December 2020 was studied.ResultsThere were 157 leads from 105 patients who underwent lead removal procedure during the specified period. Data analysis was performed from 79 TLE patients due to incomplete data and lead explant procedure of the excluded subjects. Mean patients’ age was 57.7 ± 18.7 years, with 70.9% male. There were 82 pacemaker leads, 35 ICD leads, and 5 CS leads (mean number of leads were 1.54 ± 0.66 per patient), with mean implanted duration of 87.8 ± 68.2 months. Main indication for TLE was infection-related, which accounted for 67.1% of the cases.Overall clinical success rate was 97.5%. Mean operative time was 163.8 ± 69.5 min. Major complications occurred in 4 patients (5.1%) with one in-hospital mortality from severe sepsis.ConclusionTLE using laser sheath and rotating mechanical sheath for transvenous lead extraction is effective and safe, even outside high-volume center.     

AV Nodal Reentrant Tachycardia Causing Inappropriate ICD Shocks In A Patient With Arrhythmogenic RV Dysplasia

We report a patient with an implantable cardioverter defibrillator (ICD) for arrhythmogenic right ventricular dysplasia (ARVD) who received inappropriate shocks for atrioventricular node reentry tachycardia (AVRNT). Patient had multiple shocks for tachycardia with EGM characteristics of very short VA interval and CL of 300 msec. An electrophysiologic (EP) study reproducibly induced typical AVNRT with similar features. The slow AV nodal pathway ablation resolved the ICD shocks. Despite increasingly sophisticated discrimination algorithms available in modern ICDs, the ability to differentiate SVT from VT can be challenging. Our patient received inappropriate shocks for AVNRT. When device interrogation alone is not conclusive, an EP study may be necessary to determine the appropriate therapeutic course.     

Narrating Kidney Disease: The Significance Of Sensation And Time In The Emplotment Of Patient Experience

Drawing on research conducted among patients in Ireland, this article examines the narrative constructions of chronic kidney failure and explores the ways in which patient narratives cross-cut and subvert modernist medical constructions of transplantation as a therapeutic outcome, an endgame, a “gift of life.” In experience, patients dismantle this construction structure by emplotting their stories around the painful lack of an ending, ardently brought to bear by the lived realities of immunosuppressant drug therapy, the silent fears of graft rejection, and the isolation of recipiency. They articulate, instead, stories that disclose a multi-directional flow between past and future therapeutic interventions, between the altering nature of the renal body and personal experience. These storied dimensions are phenomenologically embedded in the sensory and temporal aspects of this condition as essential elements of chronic illness and as organizational properties of patient narratives.     

Inadvertent Lead Placement In The Left Ventricle: A Case Report And Brief Review

Inadvertent lead placement in the left ventricle (LV) is an uncommon and often under-diagnosed complication of cardiac device implantation. Thromboembolic (TE) events are common and usually secondary to fibrosis or thrombus formation on or around the lead. Anticoagulation can prevent TE events. Percutaneous and surgical LV lead extractions have been performed successfully, but the risks of percutaneous lead removal are not well-defined. In this report, we describe a case of inadvertent LV lead placement and briefly review the contemporary literature.     

一种高效的植物DNA提取和PCR扩增体系建立

报道一种高效简易的植物DNA提取和PCR扩增体系。该体系仅需一步即可提取DNA,扩增时延长PCR预变性时间便能获得较好的目的基因扩增结果。本体系具有较高的实验稳定性和较好的物种适用性,将大大提高植物分子生物学实验和基于分子标记辅助的植物育种实验效率,节省科研成本。     

一种从鸟类剥制标本提取DNA的改进方法

应用非损伤性取样的方法,收集鸟类剥制标本的皮肤组织和羽毛,用无水乙醇、浸泡液预处理的方法抽提DNA,结果两者都可提取DNA供PCR扩增。将PCR产物经序列测定和比对分析,证明提取的DNA为目的DNA,表明本试验方法可行。鸟类剥制标本的皮肤组织和羽毛可以作为研究种群遗传学的资源。     

Radiofrequency Catheter Ablation Of Atrioventricular Nodal Reentry Tachycardia In A Patient With Inferior Vena Cava Anomaly

Curative radiofrequency catheter modification of the slow pathway is the recommended therapy for patients suffering from recurrent symptomatic atrioventricular nodal reentry tachycardia. This is usually performed via femoral vein and the inferior vena cava (IVC). Presence of venous occlusion or complex venous anomaly involving the IVC may preclude this approach. Here, we report a case with a complex venous anomaly involving the inferior vena cava, who underwent electrophysiological study and successful radiofrequency ablation by an alternative approach.     

Noncryogenic Preservation of Mammalian Tissues for DNA Extraction: An Assessment of Storage Methods

Reliable field methods for the storage of tissues to be used for DNA extraction and amplification are critical to many studies employing molecular techniques. Protection from DNA degradation was compared among three commonly used methods of noncryogenic storage of tissues over a time scale of 2 years. All three methods prevented DNA degradation during storage for at least 6 months. DMSO (dimethyl sulfoxide)-salt solution provided the best protection from DNA degradation of tissues stored for up to 2 years. High molecular weight DNA was recovered from lysis buffer in which tissue was stored for 2 years, however, moderate amounts of degraded DNA was also present. High molecular weight DNA was recovered from tissues stored in ethanol for 2 years, however, the yield was relatively small compared to the other two noncryogenic storage techniques. Much of the DNA degradation in ethanol preserved tissues appeared to occur during the extraction procedure and can be reduced by soaking the tissue in lysis buffer for a few hours prior to beginning the extraction. The yield of PCR products was greatest from DNA extracted from DMSO-salt solution preserved tissues, whereas DNA from tissues stored in either lysis buffer or ethanol produced lower yields.     

An Efficient Extraction Method of Persistent Organic Pesticides in Soil Samples for Their Chromatographic Determination

In order to determine persistent organic pesticides (OPs) and their metabolites in soil samples, an analytical procedure was developed, optimized and validated. It possesses advantages like suitable limits of detection, low solvent volume and time consume, and requires a chromatography detector commonly used in routine laboratories. The method allows the determination of Methoxychlor, p,p’-DDT, Endosulfan sulfate, Endrin aldehyde, p,p’-DDD, Endosulfan II, Endrin, Dieldrin, p,p’-DDE, Endosulfan I, Heptachlor epoxide, Aldrin, Heptachlor, δ-HCH, γ-HCH, β-HCH, α-HCH, Etridiazole, Trifluralin, Hexachlorobencene, Chlorothalonil, Chlorpyrifos, DCPA, γ-Chlordane, α-Chlordane, Clorbenzilate, trans-Permethrin, cis-Permethrin. Linearity is evaluated and the analytical parameters are presented. The average recoveries obtained for each pesticide (28 OPs) by using 3, 15 and 22.5 µg kg^?1 spiked samples ranged between 50 and 97.3%, 57 and 103% and from 60 to 100% for each case. The limits of detection and quantification vary from 0.18 to 1.28 μg kg^?1 and from 0.60 to 4.22 μg kg^?1. The reproducibility obtained as relative standard deviation percentages is less than 7.5, 5.3 and 4.2% for low, middle and high level of concentrations, respectively. The procedure is statistically validated for its application to soil samples and compared with other published methods.     

Radiofrequency Ablation Of Typical Atrial Flutter Via Right Subclavian/jugular Vein Access In A Patient With Implanted Filter In The Inferior Vena Cava

Radiofrequency ablation of Cavotricuspid Isthmus-dependent Atrial Flutter (CTI AFL), a usual and safe therapeutic procedure in interventional electrophysiology with a high success rate, aiming to induce permanent block of conduction over CTI, is normally performed via the femoral access, which allows practical access to the CTI through the inferior vena cava (IVC). In rare cases of obstruction of IVC, ablation of CTI can be performed only through the superior vena cava (SVC) access. We present a case of typical atrial flutter that was ablated through the right subclavian/jugular veins because of iatrogenic obstruction of the IVC due to a previously implanted thrombus filter. Furthermore we discuss about how we resolved access-related problems of instability during catheter ablation on CTI.     

An Improved Methodology to Overcome Key Issues in Human Fecal Metagenomic DNA Extraction

Microbes are ubiquitously distributed in nature, and recent culture-independent studies have highlighted the significance of gut microbiota in human health and disease. Fecal DNA is the primary source for the majority of human gut microbiome studies. However, further improvement is needed to obtain fecal metagenomic DNA with sufficient amount and good quality but low host genomic DNA contamination. In the current study, we demonstrate a quick, robust, unbiased,and cost-effective method for the isolation of high molecular weight(23 kb) metagenomic DNA(260/280 ratio 1.8) with a good yield(55.8 ± 3.8 ng/mg of feces). We also confirm that there is very low human genomic DNA contamination(eubacterial: human genomic DNA marker genes = 2~(27.9):1) in the human feces. The newly-developed method robustly performs for fresh as well as stored fecal samples as demonstrated by 16 S r RNA gene sequencing using 454 FLX+.Moreover, 16 S r RNA gene analysis indicated that compared to other DNA extraction methods tested, the fecal metagenomic DNA isolated with current methodology retains species richnessand does not show microbial diversity biases, which is further confirmed by q PCR with a known quantity of spike-in genomes. Overall, our data highlight a protocol with a balance between quality,amount, user-friendliness, and cost effectiveness for its suitability toward usage for cultureindependent analysis of the human gut microbiome, which provides a robust solution to overcome key issues associated with fecal metagenomic DNA isolation in human gut microbiome studies.     

大白菜线粒体DNA有效、快速提取方法

目的:建立一种有效、快捷的大白菜线粒体DNA(mtDNA)提取方法。方法:采用差速离心和蔗糖衬垫相结合的方法先从大白菜胞质雄性不育系及保持系叶片中分离出线粒体,然后用SDS—蛋白酶K裂解法提取mtDNA。结果:琼脂糖凝胶电泳表明,采用该方法提取的mtDNA片段大小在30~45kb之间,电泳条带清晰,无明显降解发生;以提取的mtDNA为模板进行RAPD反应,不育系和保持系均扩增出较多的条带,而且呈现出丰富的多态性,大小分布在500bp-3000bp之间,且条带清晰,没有脱尾现象。结论:该方法提取mtDNA,省时、省钱,对实验设备要求较低,而且分离出的mtDNA质量较高,能满足后续分子生物学研究工作需要。     

Unusual Pauses In Sinus rhythm And Intermittent 2 to 1 AV Block In A Patient With Concealed His Extra Systoles - A Rare Cause Of Bradycardia

A 56 year old male with a past medical history of hypertension and dyslipidemia presented with recurrent dizziness. Routine EKG was performed, which suggested frequent junctional extra systoles with compensatory pauses. During telemetry periods of 2:1 block with effective ventricular rate of 34 bpm was observed. His bundle study suggested frequent His extra systoles causing functional AV block. Treatment with anti-arrhythmic medication, paradoxically improved AV block and symptoms in our patient.     

栽培草莓叶绿体分离与cpDNA的提取方法

以栽培草莓‘红颊’(Fragaria×ananassa Duch.‘Benihoppe’)新鲜幼嫩叶片为材料,利用高盐-低pH的缓冲液结合Percoll密度梯度离心分离纯化叶绿体,再用SDS-蛋白酶K法提取叶绿体DNA(cpDNA)。经荧光显微镜、琼脂糖凝胶电泳和PCR扩增检测,结果表明:该方法分离的草莓叶绿体完整性高,叶绿体DNA质量好,纯度高,能够满足后续基因组测序等实验的基本要求,为草莓属及其他草本植物cpDNA的提取提供参考。     

An In Vitro Procedure for Estimation of Lead Relative Bioavailability: With Validation

The relative bioaccessibility leaching procedure (RBALP) is a simple, reproducible, and rapid in vitro procedure for estimating the in vivo (juvenile swine) relative bioavailability (RBA) of lead in solid media. Control of pH, temperature, and agitation are the most critical parameters of this in vitro procedure. The performance of the method was evaluated by triplicate analyses of each of 19 different test substances by the author and three independent laboratories, and comparison of the results to relative bioavailability (RBA) values measured in vivo. The results indicate that the RBALP measurements are strongly correlated with the in vivo RBA values (r² = 0.924, p < 0.0001), with an average absolute error of 10% and an average predictive error of 20%. Comparison of results within and between laboratories indicates that the procedure is highly reproducible, with inter-and intra-laboratory coefficients of variation of 4% and 6%, respectively, and within-sample precision of approximately 7%. Based on the results reported here, the RBALP can be effective in providing reliable estimates of lead RBA as predicted by the immature swine model. The method may also be valuable in evaluating site-specific differences in bioaccessibility, assessing remedial technologies intended to reduce lead RBA, providing a screening mechanism for futurein vivo studies, and providing insight into the chemical and physical factors that control lead bioavailability.     

Maintenance of Complex Life Cycles Via Cryptic Differences In The Ecophysiology Of Haploid And Diploid Spores Of An Isomorphic Red Alga1

Recognition of the wide diversity of organisms that maintain complex haploid–diploid life cycles has generated interest in understanding the evolution and persistence of such life cycles. We empirically tested the model where complex haploid–diploid life cycles may be maintained by subtle/cryptic differences in the vital rates of isomorphic haploid–diploids, by examining the ecophysiology of haploid tetraspores and diploid carpospores of the isomorphic red alga Chondrus verrucosus. While tetraspores and carpospores of this species did not differ in size or autofluorescence, concentrations of phycobiliproteins of carpospores were greater than that of tetraspores. However, tetraspores were more photosynthetically competent than carpospores over a broader range of photosynthetic photon flux densities (PPFDs) and at PPFDs found at both the depth that C. verrucosus is found at high tide and in surface waters in which planktonic propagules might disperse. These results suggest potential differences in dispersal potential and reproductive success of haploid and diploid spores. Moreover, these cryptic differences in ecological niche partitioning of haploid and diploid spores contribute to our understanding of some of the differences between these ploidy stages that may ultimately lead to the maintenance of the complex haploid–diploid life cycle in this isomorphic red alga.     

中国野生葡萄叶绿体分离及叶绿体DNA提取的研究

以中国野生刺葡萄、山葡萄、桑叶葡萄和东南葡萄的成熟叶片为材料,比较柱式植物叶绿体DNAout试剂盒和改良的高盐-低pH法分离叶绿体及提取cpDNA效果。结果显示:(1)2种方法均分离得到了中国野生葡萄的叶绿体,但与柱式植物叶绿体DNAout试剂盒相比,改良的高盐-低pH法得到的叶绿体浓度高、杂质少,更适合中国野生葡萄叶绿体分离。(2)柱式植物叶绿体DNAout试剂盒提取的cpDNA,其OD260/OD280在1.28~1.36之间,质量浓度为4.2~7.8ng·μL~(-1),质量低,不能满足后续测序要求;而改良的高盐-低pH法提取的cpDNA,其OD260/OD280值在1.84~1.90之间,质量浓度为2 514.4~4 133.7ng·μL~(-1),质量高,纯度好,能满足后续测序要求。研究表明,改良的高盐-低pH法能简便、快速获得中国野生葡萄完整叶绿体及高质量cpDNA,并且提取的cpDNA可满足后续测序要求,为葡萄属植物叶绿体基因组的深入研究奠定了基础。     

Proboscidean DNA from Museum and Fossil Specimens: An Assessment of Ancient DNA Extraction and Amplification Techniques

Applications of reliable DNA extraction and amplification techniques to postmortem samples are critical to ancient DNA research. Commonly used methods for isolating DNA from ancient material were tested and compared using both soft tissue and bones from fossil and contemporary museum proboscideans. DNAs isolated using three principal methods served as templates in subsequent PCR amplifications, and the PCR products were directly sequenced. Authentication of the ancient origin of obtained nucleotide sequences was established by demonstrating reproducibility under a blind testing system and by phylogenetic analysis. Our results indicate that ancient samples may respond differently to extraction buffers or purification procedures, and no single method was universally successful. A CTAB buffer method, modified from plant DNA extraction protocols, was found to have the highest success rate. Nested PCR was shown to be a reliable approach to amplify ancient DNA templates that failed in primary amplification.