扩散加权成像对椎体骨折性质的鉴别

目的评价磁共振的扩散加权成像(DWI)在溶骨性转移瘤和良性骨质疏松性所致椎体压缩骨折的鉴别诊断作用。方法对37例X射线诊断为椎体压缩性骨折患者,进行磁共振成像(MRI)检查,分析DWI及表观扩散系数(ADC)值在骨质疏松性和转移瘤性骨折的表现,并与病理诊断相比较。结果椎体溶骨性转移瘤致压缩骨折的DWI呈高信号有24例。溶骨性转移瘤骨折的ADC值为(1.261±0.2)×10~(-3)mm~2/s,显著高于良性骨质疏松性骨折的(0.593±0.457)×10~(-3) mm~2/s(P=0.001)。结论磁共振的DWI能够可靠地区分椎体溶骨性转移瘤骨折与良性骨质疏松性骨折,ADC值亦是一个有较大鉴别作用的指标。     

MR扩散加权成像及ADC值的测量对乳腺良恶性肿瘤腋窝淋巴结的诊断价值

目的:评价扩散加权成像及ADC值的测量对腋窝良恶性淋巴结鉴别的价值.方法:收集2006-06-2008-02在我院进行乳腺动态增强扫描及扩散加权成像,有明确手术病理结果和/或针吸活检病理结果的56例共217个痛灶作为研究对象进行回顾性分析.结果:DWI可以准确判断乳腺癌腋窝淋巴结转移,47例乳腺癌中出现163个淋巴结转移,与对照组9例54个良性病变反应增生性淋巴结在DWI均表现为高信号,随b值增加信号不减低,但前者信号高于后者;前者ADC值为(1.017±0.114)×10-3mm2/s,后者ADC值为(1.905±0.136)×10-3mm2/s,两者比较有显著性差异(P<0.05).结论:MR动态增强减影技术对乳腺良恶性病灶具有较高的诊断与鉴别诊断价值.DWI和ADC值测量是一种安全、无创、准确、快速的诊断腋窝转移性淋巴结和良性反应增生性淋巴结的手段.     

磁共振弥散加权成像在颅内囊性病变中的应用

目的探讨磁共振弥散加权成像(DWI)在颅内囊性病变鉴别诊断中的应用价值。方法对62例颅内囊性病变患者分别进行传统MRI及DWI扫描,计算病变区和健侧脑组织的表现弥散系数(ADC)值,比较其间的差别。结果脑脓肿、囊性坏死性脑肿瘤、表皮样囊肿和蛛网膜囊肿在T1WI和T2WI上呈相同的信号改变,在DWI上,脑脓肿和表皮样囊肿呈高信号,囊性坏死性脑肿瘤和蛛网膜囊肿呈低信号。脑脓肿的ADC值(5.739×10-4mm2/s)明显低于囊性坏死性脑肿瘤(28.589×10-4mm2/s),表皮样囊肿的ADC值(10.197×10-4mm2/s)明显低于蛛网膜囊肿(30.098×10-4mm2/s)。结论传统MRI通常无法对颅内囊性病变进行有效鉴别,DWI可应用于颅内囊性病变的鉴别诊断。     

弥散加权成像在眼眶良恶性肿瘤鉴别中的应用价值

目的:探讨弥散加权成像(DWI)及表观扩散系数(ADC)值对鉴别眼眶良恶性肿瘤的应用价值。方法:应用3.0T磁共振扫描仪,对46例眼眶肿瘤的患者(病理证实:28例良性肿瘤,18例恶性肿瘤)行常规MRI扫描和DWI序列扫描。观察DWI图像特征,并测量ADC值。对良性、恶性肿瘤的ADC值进行统计学比较。结果:DWI图像显示与大部分良性肿瘤相比,大多数恶性肿瘤呈高信号。良性肿瘤的ADC值为(1.34±0.25)×10-3mm2/s;恶性肿瘤的ADC值为(0.76±0.14)×10-3mm2/s,良恶性肿瘤的ADC值之间的差异具有统计学意义(t=6.335,P=0.000<0.01)。结论:DWI为眼眶良恶性肿瘤的鉴别诊断提供了有效的影像学依据。     

磁共振动态增强和弥散加权成像在颅内感染诊断中的应用价值

目的探讨磁共振动态增强和弥散加权成像在颅内感染诊断中的应用价值。方法研究收集2015年11月-2017年8月于中山一院神经内科/外科经手术或脑脊液细菌学培养明确诊断为中枢神经系统感染患者68例,所有入组患者均行常规磁共振成像(Magnetic Resonance Imaging,MRI)检查、弥散加权成像及动态增强扫描,分析各类颅内感染性病变的影像特征、表观弥散系数(apparent diffusion coefficient,ADC)值变化情况,比较弥散加权成像及动态增强扫描在颅内感染性疾病中的应用价值。结果颅内感染性病变可因致病因素的不同而表现出不同的影像征象,如病毒性感染的发病部位多位于边缘系统(颞叶、岛叶等区域),而结核感染则好发于脑底部(鞍上池等),DWI序列除寄生虫感染外,其他类圆形病原体感染均表现为高/稍高信号,ADC值不同程度减低,增强扫描呈轻度强化。病毒性脑炎、化脓性细菌感染、结核杆菌感染及真菌感染的患者ADC值分别为0.571×10~(-3)mm~2/s、0.347×10~(-3)mm~2/s、0.621×10~(-3)mm~2/s、0.578×10~(-3)mm~2/s,较正常脑实质的ADC值0.980×10~(-3)mm~2/s均减低,其中以化脓杆菌感染患者ADC值减低为著(P<0.05);MRI DWI序列及动态增强扫描序列对病毒、化脓性细菌、结核、真菌以及寄生虫感染的诊断符合率均要高于常规MRI序列,但MRI动态扫描在鉴别病毒、化脓性细菌、结核及寄生虫感染方面,优于DWI序列(P<0.05)。结论 MRI DWI序列及动态增强扫描序列能够显著提高各类颅内感染性病变的诊断符合率,且MRI动态扫描在鉴别病毒、化脓性细菌、结核及寄生虫感染方面,要优于DWI序列。     

原发性颅内毛细胞星形细胞瘤的MRI与扩散特征分析

目的:探讨原发性颅内毛细胞星形细胞瘤的常规MRI与扩散特征。方法:回顾性分析17例经手术、病理证实的原发性颅内毛细胞星形细胞瘤的常规MRI、MR扩散加权成像(DWI)特征,定量测定肿瘤实质和对侧正常脑白质区表观扩散系数(ADC)的值,比较两者平均ADC值的差异。结果:17例毛细胞星形细胞瘤MRI表现为囊性部分呈长T1长T2信号,实性部分呈等、稍长T1等、稍长T2信号。增强扫描可以分为不强化的囊壁及显著强化的壁结节、环形强化的囊壁及显著强化的壁结节、单纯环形强化的囊壁、实性肿瘤的均匀强化、肿瘤大部分为实性成分的不均匀强化等几种。肿瘤DWI低信号15例,等低混杂样信号2例,SWI可见低信号2例,信号低于对侧正常脑实质,ADC值升高。瘤体ADC值为(1.46～1.93)×10-3mm2/s,高于肿瘤对侧正常脑实质区的ADC值(0.86～1.26)×10-3mm2/s,差异有统计学意义(t=7.139,P<0.01)。结论:在传统的MRI序列基础上,应用DWI成像技术对于毛细胞星形细胞瘤的诊断及鉴别诊断具有重要作用。     

多序列磁共振对儿童溃疡性结肠炎活动性的诊断价值

目的探讨多序列磁共振(MRI)检查在儿童溃疡性结肠炎患儿中的应用价值。方法选取医院2019年10月至2021年9月经内镜证实为儿童溃疡性结肠炎患者18例。所有患者均行MRI检测,分析儿童溃疡性结肠炎活动期病变肠壁及非病变肠管壁扩散加权成像(DWI)信号及表观扩散系数(ADC)值差异。结果儿童溃疡性结肠炎肠壁活动期DWI为中高-高信号17例,稍低信号1例,ADC值为(1.55±0.12)×10^(-3)mm^(2)/s,非病变段肠壁DWI信号为稍低-低信号18例,ADC值为(2.10±0.14)×10^(-3)mm^(2)/s,两组DWI信号与ADC值比较差异均有统计学意义(P<0.05)。结论多序列MRI扫描中DWI信号及ADC值可为儿童溃疡性结肠炎活动期判定提供一定的诊断价值。     

基底节区病毒性脑炎和急性脑梗死的磁共振诊断

目的 探讨磁共振DWI及ADC值对累及基底节区的病毒性脑炎和急性脑梗死的鉴别诊断.方法 回顾性分析累及基底节区的69例病毒性脑炎(A组)、100例急性脑梗死(B组)的常规MRI和DWI资料,以60例健康成人作为对照组(C组),比较分析ADC值.结果 A组病灶DWI呈稍高信号,B组病灶呈明显高信号,A组病灶DWI信号较B组低;A组病灶ADC图均呈稍低或低信号,B组病灶均呈明显低信号.A、B组病灶平均ADC值为(0.78±0.19)×10-3和(0.39±0.16)×10-3 mm2/s,对照组为(0.96±0.26)×10-3 mm2/s,三组间两两比较差异有统计学意义.病毒性脑炎常同时累及多个脑叶,急性脑梗死病灶范围与血供分布区域一致.结论 磁共振DWI及ADC值能反映病变组织微观结构的信息变化,对基底节区病毒性脑炎和急性脑梗死的早期诊断和鉴别诊断有一定帮助.     

磁共振扩散加权成像在前列腺疾病中的诊断价值

目的：探讨磁共振扩散加权成像（DWI）对前列腺疾病的诊断与鉴别诊断价值。方法：选取118例前列腺疾病患者,其中BPH患者71例,前列腺癌患者47例。所有患者均进行磁共振常规扫描和DWI扫描,分析前列腺增生（BPH）和前列腺癌的DWI和表观扩散系数（ADC）图表现,并测量癌肿区的ADC值及BPH的平均ADC值,进行统计学分析。结果：BPH的DWI和ADC图上外周带信号均匀,中央腺体区信号不均匀;前列腺癌病灶在DWI上呈高信号,ADC图呈低信号,受累的精囊,淋巴结转移和骨转移病灶DWI上呈高信号,ADC图上呈低信号;前列腺癌的ADC值（78±16）×10-5mm2/s,BPH组的平均ADC值为（146±44）×10-5mm2/s,两者差异有统计学意义（P〈0.05）。结论：DWI检查在前列腺相关疾病诊断中有特征性表现,并对前列腺增生和前列腺癌具有鉴别诊断价值。     

磁共振弥散加权成像在宫颈癌放化疗疗效早期评估作用

目的：评估宫颈癌放化疗应用磁共振弥散加权成像(DWI)进行早期评估的作用效果。方法：选择本院经手术或宫颈病理活检诊断确诊的60例宫颈癌患者作为观察组,选择同期接受检查的非盆腔疾病患者60例作为对照组,术前开展磁共振成像(MRI)与DWI检查,比较两组检查时表现扩散系数(ADC)在不同病理与疗效时的数值差异变化。结果：对照组开展DWI检查显示,T1WI为均匀等信号,T2WI为多层样改变,宫颈管内黏液呈高信号,宫颈黏膜皱襞与子宫肌外层为中等信号,宫颈纤维基质为低信号;宫颈管内膜ADC值为(1.35±0.17)×10-3mm²/s,结合带ADC值为(1.54±0.15)×10-3mm²/s,肌层ADC值为(2.02±0.22)×10-3mm²/s。观察组宫颈癌患者的T1WI为等信号,T2WI呈均匀或混杂稍高信号影,DWI呈高信号,平均ADC值为(0.95±0.13)×10-3mm²/s,与对照组正常宫颈平均ADC相比更低,有统计差异(P<0.05)。宫颈鳞癌的ADC值(0.89±0.12)×10-3...     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.