Doped diamond-like carbon coatings for surgical instruments reduce protein and prion-amyloid biofouling and improve subsequent cleaning

Doped diamond-like carbon (DLC) coatings offer potential antifouling surfaces against microbial and protein attachment. In particular, stainless steel surgical instruments are subject to tissue protein and resilient prion protein attachment, making decontamination methods used in sterile service departments ineffective, potentially increasing the risk of iatrogenic Creutzfeldt-Jakob disease during surgical procedures. This study examined the adsorption of proteins and prion-associated amyloid to doped DLC surfaces and the efficacy of commercial cleaning chemistries applied to these spiked surfaces, compared to titanium nitride coating and stainless steel. Surfaces inoculated with ME7-infected brain homogenate were visualised using SYPRO Ruby/Thioflavin T staining and modified epi-fluorescence microscopy before and after cleaning. Reduced protein and prion amyloid contamination was observed on the modified surfaces and subsequent decontamination efficacy improved. This highlights the potential for a new generation of coatings for surgical instruments to reduce the risk of iatrogenic CJD infection.     

超声空化强度测量的研究进展

近几十年来,超声波已经广泛应用于生物学和医学领域,在医学领域中超声波可以作为信息载体用于探测人体的病变信息,并且可以用一定剂量的超声波作用于人体病变组织,并通过它对组织的作用达到一定的治疗目的。作为一种无创、非介入性外科技术,它的疗效和安全性越来越被人们所关注。超声波与人体组织的相互作用有三种,分别是机械机制,热学机制,和空化机制。对于机械机制和热机制人们比较熟悉,而对于空化机制则相对陌生。随着超声空化在医学中的应用越来越广泛,其安全性越来越受到人们的关心。要么是其强度迭不到治疗效果,要么是其强度过大损伤人体,因此其强度已成为人们关心的主要主题。本文主要介绍超声空化的主要探讨了几种测量方法及对超声空化有影响的几种参量,并对超声空化的发展进行了展望。     

Advantages of ultrasonic surgical instruments in experimental neurophysiology

The effect of ultrasonic neurosurgical instruments on the functional state of the brain and its individual structures was studied to establish the most adequate and the least traumatic method of brain structures extirpation. Cortical zones were destroyed by ultrasound, thermocoagulated or extirpated. Parallel recordings of evoked potentials to single and paired stimuli were performed in adjacent neocortical areas. It was established that ultrasonic instruments permit the least traumatic extirpation of brain cortical zones.     

Evaluation of non-specific tissue alkaline phosphatase on bone samples from traditional and piezoelectric osteotomy

The aim of this study is to test the response of bone during cutting actions in dental procedures by sampling alkaline phosphatase (ALP) as a biological reference marker. ALP is found abundantly in bone tissue. In the first series of experiments a temporal-minimum quantity of ALP enzyme response was recorded, the observed period was 40 minutes. The ALP samples treated with piezoelectric surgery showed a rapid increase, with peak at 30 min, and then declined rapidly within the next 10 minutes. A second experiment was performed to evaluate 4 cutting instruments: drill bits high speed turbine (T1); drill bits contra-angle (T2) Piezoelectric insertions (T3), and manual instruments (controls). This second experiment was to evaluate the ALP activity at 30 min. The T1 samples produced the highest results (3,66499 +- 0,51394); control groups had a lower response (0,72793 +- 0,22353), while the T2 group produced statistically significant higher results (2,77793 +- 0,40553) than T3 (1,16608 +- 0,32676). The different values obtained for ALP in these two experiments for a short period of time (30 min) cannot be interpreted as a response of bone tissue regeneration subjected to surgical trauma. The MINIMUM trauma caused by the surgical piezoelectric instruments, in respect to conventional surgical instruments is clearly evident from the phosphatase inflammatory activity.     

Effects of traditional and ultrasonic liposuction on adipose tissue: a biochemical approach

Little is known about the interaction of ultrasonic liposculpture with fat tissue. The surgical technique is well established and its clinical effects are satisfactory. However, the in vivo effects on adipose tissue remain to be determined. Previous studies have shown that ultrasound waves break fat cells. The purpose of this study was to ascertain whether ultrasound waves can cause the release of fatty acids from the molecular structure of triglycerides. A double-blind study was designed with samples obtained from traditional and ultrasonic liposuction of an equivalent area in the same patient. Samples were checked for triglycerides and for free fatty acids. Triglyceride values were always higher in the sample that had undergone ultrasonic procedure. No significant differences were observed between the free fatty acid chromatograms of the two kinds of samples analyzed. Data showed that no changes occurred in the triglyceride molecule when using ultrasound waves in the experimental conditions.     

环境介质中铂族金属形态分析方法的研究进展

环境中铂族金属(PGMs)的赋存形态多样,形态分析对识别其生态风险具有十分重要的意义。本文综述了环境中3种主要铂族金属(铂、钯、铑)的形态分析方法,包括化学顺序提取、仪器联用技术及计算机模拟等,概述了这些方法的类型、特点及应用,同时阐述了它们存在的不足,并对未来发展方向进行了展望。化学顺序提取法普遍用于固相样品形态分析,当前研究中提出的提取条件和步骤多样,但不能很好地标准化;仪器联用技术在溶液元素形态分析上具有显著优势,毛细管电泳联用系统能够分离具有相同电泳能力的相似物质,但在分离能力和检出限方面不如液相色谱联用系统;计算机模拟则进一步拓展了形态分析的途径,能够实现复杂的形态计算。建议今后将多个方法进行结合,通过相互补充与完善,不断提高分析技术准确性。     

Surgical implantation techniques for electronic tags in fish

Intracoelomic implantation of transmitters into fish requires making a surgical incision, incision closure, and other surgery related techniques; however, the tools and techniques used in the surgical process vary widely. We review the available literature and focus on tools and techniques used for conducting surgery on juvenile salmonids because of the large amount of research that is conducted on them. The use of sterilized surgical instruments properly selected for a given size of fish will minimize tissue damage and infection rates, and speed the wound healing of fish implanted with transmitters. For the implantation of transmitters into small fish, the optimal surgical methods include making an incision on the ventral midline along the linea alba (for studies under 1 month), protecting the viscera (by lifting the skin with forceps while creating the incision), and using absorbable monofilament suture with a small-swaged-on swaged-on tapered or reverse-cutting needle. Standardizing the implantation techniques to be used in a study involving particular species and age classes of fish will improve survival and transmitter retention while allowing for comparisons to be made among studies and across multiple years. This review should be useful for researchers working on juvenile salmonids and other sizes and species of fish.     

Modelling of non-linear elastic tissues for surgical simulation

Realistic modelling of the interaction between surgical instruments and human organs has been recognised as a key requirement in the development of high-fidelity surgical simulators. Primarily due to computational considerations, most of the past real-time surgical simulation research has assumed linear elastic behaviour for modelling tissues, even though human soft tissues generally possess non-linear properties. For a non-linear model, the well-known Poynting effect developed during shearing of the tissue results in normal forces not seen in a linear elastic model. Using constitutive equations of non-linear tissue models together with experiments, we show that the Poynting effect results in differences in force magnitude larger than the absolute human perception threshold for force discrimination in some tissues (e.g. myocardial tissues) but not in others (e.g. brain tissue simulants).     

Finite element modeling of the left atrium to facilitate the design of an endoscopic atrial retractor

With the worldwide prevalence of cardiovascular diseases, much attention has been focused on simulating the characteristics of the human heart to better understand and treat cardiac disorders. The purpose of this study is to build a finite element model of the left atrium (LA) that incorporates detailed anatomical features and realistic material characteristics to investigate the interaction of heart tissue and surgical instruments. This model is used to facilitate the design of an endoscopically deployable atrial retractor for use in minimally invasive, robotically assisted mitral valve repair. Magnetic resonance imaging (MRI) scans of a pressurized explanted porcine heart were taken to provide a 3D solid model of the heart geometry, while uniaxial tensile tests of porcine left atrial tissue were conducted to obtain realistic material properties for noncontractile cardiac tissue. A finite element model of the LA was constructed using ANSYS Release 9.0 software and the MRI data. The Mooney-Rivlin hyperelastic material model was chosen to characterize the passive left atrial tissue; material constants were derived from tensile test data. Finite element analysis (FEA) models of a CardioVations Port Access retractor and a prototype endoscopic retractor were constructed to simulate interaction between each instrument and the LA. These contact simulations were used to compare the quality of retraction between the two instruments and to optimize the design of the prototype retractor. Model accuracy was verified by comparing simulated cardiac wall deflections to those measured by MRI. FEA simulations revealed that peak forces of approximately 2.85 N and 2.46 N were required to retract the LA using the Port Access and prototype retractors, respectively. These forces varied nonlinearly with retractor blade displacement. Dilation of the atrial walls and rigid body motion of the chamber were approximately the same for both retractors. Finite element analysis is shown to be an effective tool for analyzing instrument/tissue interactions and for designing surgical instruments. The benefits of this approach to medical device design are significant when compared to the alternatives: constructing prototypes and evaluating them via animal or clinical trials.     

Simple techniques for freeze clamping and for cutting and milling of frozen tissue at low temperature for the purpose of two- or three-dimensional metabolic studies in vivo

A technique is described for freeze-clamping of parenchymal tissue (e.g., liver) which causes the tissue to be rigidly fixed to an aluminium cup in the frozen state with a well-defined, reproducible orientation of the tissue as well as a minimum of morphological distortion of the major part of the sample. Furthermore, three instruments for low-temperature cutting or milling of the frozen sample for the purpose of two- or three-dimensional metabolic studies are described. The cutting and milling instruments work according to the principle of ordinary workshop machines for steel work. The frozen sample fixed in the aluminium cup may be mounted in the milling instrument and cut at the temperature of liquid nitrogen with high precision; e.g., one instrument may be adjusted to mill off tissue layers of a thickness of only 20 μm. Thermocouple readings from the frozen sample suggest that the milling process does not cause significant heating of the sample. This is further supported by the fact that the amount of labile metabolites, ATP, ADP, AMP, lactate, and pyruvate, is unaffected by the milling process.     

Ultrasonic characterization of biological tissues

Ultrasonic imaging has become increasingly important as a diagnostic tool in medicine because it is noninvasive and it can provide valuable information otherwise unattainable. However, at present, clinical interpretation of an ultrasonic image still mostly relies on recognition of boundaries and positional relationship of anatomical structures and a subjective analysis of the distribution or texture of echo amplitudes. Other potentially useful information carried back by the echoes is completely discarded. The aim of ultrasonic tissue characterization research is to develop methods to extract additional information from the returned echoes so that tissue pathology or abnormality can be reliably identifed and severity of the pathology objectively assessed with quantitative criteria. A number of ultrasonic parameters including acoustic velocity, impedance, attentuation and scattering, have been utilized in attempting to achieve this goal. In this paper, recent progress in this research will be discussed and relevant results presented.     

生物组织超声散射系数与温度相关性的研究

在随机起伏介质超声散射理论基础上,根据生物非均匀介质中声波动方程,推导出散射系数与温度的关系,然后分别采用了回波直接截取、经验模态分层（EDM）两种方法进行实验验证分析.结果表明超声散射系数与温度有依次递增的对应关系,可以运用它从超声回波信号中有效地提取组织温度信息.经验模态分层法的数据处理结果一致性要好些,总体趋势更接近理论分析.     

Rapid cooling via dry ice preserves the genetic and morphological integrity of fish embryos

Larval fishes provide a valuable metric for assessing and monitoring species, populations, and ecosystem trends and condition. However, taxonomic resolution for this life stage is inherently problematic because of their individual sizes, limited morphological characteristics and high tissue degradation rates. There is little research on methods that rapidly preserve larval tissues for later morphological and molecular identification. The goal of this study was to test methods of rapidly killing fish embryos that maintain both morphological and molecular integrity. Rapid cooling with dry ice successfully maintained morphological and molecular integrity and may offer a simple and cost-effective approach for larval fish identification.     

Evaluation of residual protein on unprocessed and decontaminated dental extraction forceps

Research into protein contamination of surgical instruments has received increasing attention and has focused on a quantitative analysis, without subsequent identification of these proteins. This study aimed to validate methods for the isolation and identification of instrument protein contamination using extraction forceps as a model. The working ends of used, unclean and decontaminated forceps were boiled in 1% (v/v) SDS and samples precipitated using StrataClean? resin and Amicon® filtration. Proteins were visualised using SDS-PAGE and identified by mass spectrometry and Western blot. A total of 17 proteins were identified from used, unclean forceps, including blood and bacterial proteins and 2 protein bands from decontaminated forceps samples which could not be accurately identified. The methods described, when used in conjunction with quantitative and surface analysis of instruments, can aid development of cleaning processes by identifying contaminants on used devices that have been removed following cleaning.     

Rapid Detection of high-level oncogene amplifications in ultrasonic surgical aspirations of brain tumors

ABSTRACT: BACKGROUND: Genomic tumor information, such as identification of amplified oncogenes, can be used to plan treatment. The two sources of a brain tumor that are commonly available include formalin-fixed, paraffin-embedded (FFPE) sections from the small diagnostic biopsy and the ultrasonic surgical aspiration that contains the bulk of the tumor. In research centers, frozen tissue of a brain tumor may also be available. This study compared ultrasonic surgical aspiration and FFPE specimens from the same brain tumors for retrieval of DNA and molecular assessment of amplified oncogenes. METHODS: Surgical aspirations were centrifuged to separate erythrocytes from the tumor cells that predominantly formed large, overlying buffy coats. These were sampled to harvest nuclear pellets for DNA purification. Four glioblastomas, 2 lung carcinoma metastases, and an ependymoma were tested. An inexpensive PCR technique, multiplex ligation-dependent probe amplification (MLPA), quantified 79 oncogenes using 3 kits. Copy number (CN) results were normalized to DNA from non-neoplastic brain (NB) in calculated ratios, [tumor DNA]/[NB DNA]. Bland-Altman and Spearman rank correlative comparisons were determined. Regression analysis identified outliers. RESULTS: Purification of DNA from ultrasonic surgical aspirations was rapid (<3 days) versus FFPE (weeks) and yielded greater amounts in 6 of 7 tumors. Gene amplifications up to 15-fold corresponded closely between ultrasonic aspiration and FFPE assays in Bland-Altman analysis. Correlation coefficients ranged from 0.71 to 0.99 using 3 kit assays per tumor. Although normalized CN ratios greater than 2.0 were more numerous in FFPE specimens, some were found only in the ultrasonic surgical aspirations, consistent with tumor heterogeneity. Additionally, CN ratios revealed 9 high-level ([greater than or equal to] 6.0) gene amplifications in FFPE of which 8 were also detected in the ultrasonic aspirations at increased levels. The ultrasonic aspiration levels of these amplified genes were also greater than 6.0 CN ratio, except in one case (3.53 CN ratio). Ten of 17 mid-level ([greater than or equal to]3.0 & <6.0 CN ratio) amplifications detected in FFPE were also detected as being increased ([greater than or equal to] 2.0 CN ratio) in the aspirations. CONCLUSIONS: Buffy coats of centrifuged ultrasonic aspirations contained abundant tumor cells whose DNA permitted rapid, multiplex detection of high-level oncogene amplifications that were confirmed in FFPE. Virtual slides http://www.diagnosticpathology.diagnomx.eu/vs/1883718801686466.     

Evaluation of residual protein on unprocessed and decontaminated dental extraction forceps

Research into protein contamination of surgical instruments has received increasing attention and has focused on a quantitative analysis, without subsequent identification of these proteins. This study aimed to validate methods for the isolation and identification of instrument protein contamination using extraction forceps as a model. The working ends of used, unclean and decontaminated forceps were boiled in 1% (v/v) SDS and samples precipitated using StrataClean? resin and Amicon? filtration. Proteins were visualised using SDS-PAGE and identified by mass spectrometry and Western blot. A total of 17 proteins were identified from used, unclean forceps, including blood and bacterial proteins and 2 protein bands from decontaminated forceps samples which could not be accurately identified. The methods described, when used in conjunction with quantitative and surface analysis of instruments, can aid development of cleaning processes by identifying contaminants on used devices that have been removed following cleaning.     

RFID技术在手术灭菌器械质量追溯管理中的应用

根据原卫生部提出的手术灭菌器械的可追溯管理要求,采用RFID信息化追溯管理技术,通过与医院HIS对接,结合无线网络、中间件等技术,实现了手术器械从回收、清洗、检查、包装、灭菌、发放和使用各个关键环节信息数据的全程跟踪监控,有效保证了各类手术器械的质量管理,使消毒供应中心工作更加科学、规范、高效、便捷,提升了医院手术器械的管理水平。     

基于B超图像评价HIFU治疗剂量对组织损伤程度的影响

基于B超图像分析HIFU治疗中辐照剂量、组织凝固性坏死区域和图像参数之间的关系。通过对高强度聚焦超声辐照新鲜离体组织前后获得的B超图像做数字减影处理,计算图像灰度平均值,同时切片观察并记录生物组织的凝固性坏死区域大小,在此基础上得到大批量数据的统计特性。结果表明：辐照剂量、组织凝固性坏死区域与B超图像灰度平均值在一定范围内成正相关性;当凝固性坏死区域增大到一定程度时,B超图像灰度平均值不再增大,而是呈无规律分布。B超图像灰度可反映组织损伤程度,为实时监控HIFU治疗效果提供依据。     

防护细节管理在消毒供应中心微生物污染手术器械处理中的应用

探讨防护细节管理在消毒供应中心微生物污染手术器械处理中的应用价值。

随机选取我院做到防护细节管理的600件手术器械(A组)和未实施防护细节管理的600件手术器械(B组)作为研究对象, 对比实施防护细节管理对手术器械微生物污染的影响。比较实施前后器械无菌检验和微生物限度检验一次合格率、质量管理情况(回收、分类、清洗消毒、包装不合格情况)以及患者医院感染发生率变化情况。

A组器械无菌检验一次合格率为98.67%, B组器械其一次检验合格率为95.67%, 差异有统计学意义(χ²=9.953, P=0.001 6)。A组器械微生物限度检验一次合格率为99.33%, B组为95.17%(χ²=9.305, P=0.002 3)。A组器械回收不合格率为0.33%, B组不合格率为2.00%。A组器械分类不合格率为0.50%, B组为1.50%。A组器械清洗消毒不合格率为0.83%, 器械包装不合格率为0.33%;B组器械清洗消毒不合格率为1.83%, 手术器械包装不合格率1.33%。A组和B组器械导致的医院感染发生率分别为0.67%、1.67%。

防护细节管理在降低消毒供应中心手术器械微生物的污染, 提高管理质量以及降低医院感染发生率方面有重要价值。

     

生物组织散射元平均间距估计的一种新方法

生物组织散射元平均间中划描述生物组织微观结构特性和生物组织超微散射特性的重要参数。本文在对生物组织超声背向散射随机模的基础上,提出了基于生物组织超声背向散射信号突变点检测的工用射元平均间距估计的新方法。该方法是生物组织超声散射分析的有效方法。