Retrievable inferior vena cava filter to prevent pulmonary embolism in patients with fractures and deep venous thrombosis of lower extremities: a single-center experience

ObjectiveTo evaluate the effectiveness of inserting a retrievable inferior vena cava filter (IVCF) to prevent pulmonary embolism (PE) in patients with bone fractures and acute deep venous thrombosis (DVT) before major orthopedic surgery.MethodsClinical data of patients with fractures and acute DVT who underwent IVCF insertion were analyzed. The patients were divided into above-knee DVT (AKDVT), popliteal vein thrombosis (PVT), and below-knee DVT (BKDVT) groups.ResultsAn IVCF was successfully implanted in 964 patients, among whom 929 were followed up (335, 470, and 124 in AKDVT, PVT, and BKDVT groups, respectively). There was no significant difference in the incidence of filter thrombosis among the groups (11.04%, 11.70%, and 8.06%, respectively). No symptomatic PE occurred during follow-up. The mean filter indwelling time was 18.4 ± 4.3 days, and the total filter removal rate was 76.87%. There was no significant difference in the rate of filter implantation, retrieval, complications, or mortality among the groups.ConclusionsRetrievable filters can effectively prevent PE before orthopedic surgery in patients with fractures and acute DVT of the lower limbs. AKDVT more readily forms a ≥1-cm thrombus in the IVCF than does BKDVT, and PVT more readily forms a <1-cm thrombus than does AKDVT.     

腔静脉滤器的临床应用:贵在恰当

分析临床应用腔静脉滤器的历史与现状,并对腔静脉滤器有可能被滥用的趋势,提出有必要重新审视滤器应用带来的利与弊,以及思考滤器植入的适应人群.该文对理想的腔静脉滤器应具备的条件,腔静脉滤器植入的适应证和植入后并发症的分析,认为可回收滤器的临床应用有逐步取代永久性滤器的趋势,也是未来腔静脉滤器的研究方向.     

大剂量尿激酶溶栓联合下腔静脉滤器预防肺动脉栓塞的效果观察

目的探讨下腔静脉滤器预防肺动脉栓塞的效果。方法对4例已形成肺动脉栓塞的患者,先行肺动脉介入治疗溶栓,然后如其余病例一样放置滤器,术后适当抗凝,积极溶栓。结果肺动脉介入溶栓后,血氧分压回升;放置滤器后,配合大剂量尿激酶溶栓,患者临床症状改善,患肢消肿。结论下腔静脉滤器可有效地阻止脱落的深静脉血栓流入肺动脉,术后能用大剂量尿激酶,使血栓溶解或消失。     

The use of dried cerebrospinal fluid filter paper spots as a substrate for PCR diagnosis of the aetiology of bacterial meningitis in the Lao PDR

We investigated whether dried cerebrospinal fluid (CSF) conserved on filter paper can be used as a substrate for accurate PCR diagnosis of important causes of bacterial meningitis in the Lao PDR. Using mock CSF, we investigated and optimized filter paper varieties, paper punch sizes, elution volumes and quantities of DNA template to achieve sensitive and reliable detection of bacterial DNA from filter paper specimens. FTA Elute Micro CardTM (Whatman, Maidstone, UK) was the most sensitive, consistent and practical variety of filter paper. Following optimization, the lower limit of detection for Streptococcus pneumoniae from dried mock CSF spots was 14 genomic equivalents (GE)/μL (interquartile range 5.5 GE/μL) or 230 (IQR 65) colony forming units/mL. A prospective clinical evaluation for S. pneumoniae, S. suis and Neisseria meningitidis was performed. Culture and PCR performed on fresh liquid CSF from patients admitted with a clinical diagnosis of meningitis (n = 73) were compared with results derived from dried CSF spots. Four of five fresh PCR-positive CSF samples also tested PCR positive from dried CSF spots, with one patient under the limit of detection. In a retrospective study of S. pneumoniae samples (n = 20), the median (IQR; range) CSF S. pneumoniae bacterial load was 1.1 × 10⁴ GE/μL (1.2 × 10⁵; 1 to ×.1 × 10⁶ DNA GE/μL). Utilizing the optimized methodology, we estimate an extrapolated sensitivity of 90%, based on the range of CSF genome counts found in Laos. Dried CSF filter paper spots could potentially help us to better understand the epidemiology of bacterial meningitis in resource-poor settings and guide empirical treatments and vaccination policies.     

Subtraction procedure for powerline interference removing from ECG: improvement for non-multiple sampling

This paper presents an improvement of the subtraction procedure for interference cancellation in ECG. In contrast to the well-known hardware and software filters, the procedure does not affect the signal frequency components around the rated powerline frequency. Originally, the procedure was developed for multiplicity between the sampling rate and the interference frequency. We analysed and improved the procedure structure in cases of non-multiple sampling, introducing a set of specially designed filters. Thus the implementation of the subtraction procedure is extended to almost all possible cases of sampling rate and interference frequency variation. The procedure has been adapted for online implementation. The research was initially carried out in a MATLAB environment. Further, programmes have been written in C^?+?+ language for digital signal processors and personal computers. The results obtained with real ECG signals show high efficiency of the interference cancellation.     

牡蛎壳的生物相容性评价：细胞毒性和遗传毒性研究

目的：探讨天然牡蛎壳粉末的生物相容性,为其进一步在临床上作为牙齿根管充填材料的研究提供理论依据。方法：按照我国医药行业对口腔材料生物学评价要求,制备牡蛎壳粉末的浸提液。分别采用分子滤过法和鼠伤寒沙门氏菌回复突变试验（Ames试验）的平板掺入法,对牡蛎壳粉末浸提液进行细胞毒性和遗传毒性检测。用测量滤膜褪色面积和计数平皿中细菌回变菌落数的方法判断该材料的毒性。结果：分子滤过法2h实验结果显示细胞毒性为0级,24h试验结果细胞毒性为1级。Ames各试验组菌落回变数均未高于相应菌株自发回变菌落数的2倍,且无剂量反应关系,实验结果为阴性。结论：牡蛎壳粉末具有较好的细胞生物相容性,致突变试验为阴性,对机体没有潜在的遗传毒性作用,符合口腔材料的临床前生物学要求。     

Fast Shear Compounding Using Robust 2-D Shear Wave Speed Calculation and Multi-directional Filtering

A fast shear compounding method was developed in this study using only one shear wave push-detect cycle, such that the shear wave imaging frame rate is preserved and motion artifacts are minimized. The proposed method is composed of the following steps: 1. Applying a comb-push to produce multiple differently angled shear waves at different spatial locations simultaneously; 2. Decomposing the complex shear wave field into individual shear wave fields with differently oriented shear waves using a multi-directional filter; 3. Using a robust 2-D shear wave speed calculation to reconstruct 2-D shear elasticity maps from each filter direction; and 4. Compounding these 2-D maps from different directions into a final map. An inclusion phantom study showed that the fast shear compounding method could achieve comparable performance to conventional shear compounding without sacrificing the imaging frame rate. A multi-inclusion phantom experiment showed that the fast shear compounding method could provide a full field-of-view, 2-D and compounded shear elasticity map with three types of inclusions clearly resolved and stiffness measurements showing excellent agreement to the nominal values.