机械应力对幼鼠髋臼发育影响的实验研究

目的阐明异常机械应力对髋臼发育和髋臼软骨生长板内软骨细胞增殖的影响,探讨髋臼发育不良的修复方法。方法将60只3周龄的雌性Wistar大鼠分成3组,每组20只,左侧髋关节为实验侧,右侧为对照侧。A组:在2周内反复将髋关节手法脱位后再复位;B组:膝关节伸直位钢针固定,制作髋臼发育不良的动物模型,2周后拔出钢针;C组:持续伸直位固定膝关节。三组动物分别于第5、7、9、12周时进行钼靶软X线、组织形态学及透射电镜观察。结果A组第5周时唇缘变钝,髋臼角比对侧增大约5°,软骨生长板内增殖层软骨细胞极向紊乱,SO染色无差异,圆韧带有淋巴细胞浸润,第7、9、12周时变化小,两侧无差异;B组第5周时髋臼角比对侧明显增大,第7周时唇缘变钝、内翻,纤维增生,柱状细胞极性紊乱,肥大细胞层增多,第9、12周时接近正常,12周时髋臼角为23.4°,髋臼入口最短径为5.0mm;C组髋臼角比对侧持续增大,没有任何改善倾向,第12周时唇缘内翻、扁平,无明显柱状细胞排列,细胞核变小,细胞器减少,空泡形成,髋臼角为71.3°,髋臼入口最短径为2.9mm。结论在髋臼发育旺盛期解除异常机械应力、恢复头臼同心,髋臼发育不良有治愈倾向。造成髋臼发育不良的直接原因是软骨生长板内增殖层软骨细胞代谢功能发生改变,骨化延迟。     

Mechanobiology and force transduction in scars developed in darker skin types

BACKGROUND: Scarring is a complex process involving many cell types, cytokines and biological pathways including mechanobiology. Some subtle mechanical properties of skin can be assessed by measuring the speed of ultrasound shear wave propagation. The orientation of abnormal skin tension forces can be visualized, particularly in darker skin types, using dermoscopy showing distinct patterns of rete ridges' conformation. AIM: To assess some mechanobiological features of scars in darker skin types. PATIENTS AND METHODS: Large atrophic and hypertrophic surgical scars were examined on the trunk of 35 darker skin subjects. The surrounding skin was used as a comparator. Dermoscopic aspects were recorded. Resonance running time measurements (RRTM) were performed using a shear wave propagation device (Reviscometer). They were performed in four specific directions at given angles with regard to the long axis of the scar. The minimum, maximum and mean RRTM values were recorded at each site. RESULTS: Dermoscopy revealed patterns of melanin deposits in scars distinct from the normal honeycomb network seen in the surrounding skin. Hypertrophic scars showed a patchy pattern of large macular melanoderma dispersed in a lighter background. In these cases, low RRTM values were obtained with little variations according to the orientation of the measurements. By contrast, atrophic scars showed a streaky laddering melanotic pattern under dermoscopy. Higher RRTM values were often obtained, particularly in the transversal direction of the scars. Mechanical anisotropy was greater in the atrophic scars compared with the normal skin. DISCUSSION: Darker skin types represent a model for visualizing the main orientation of the epidermal rete ridges. A correlation was found between the pattern of melanized rete ridges of scars and the main orientation of the intrinsic forces in the skin.     

Distal radial fractures Injectable calcium phosphate bone cement versus conventional treatment

AMEDLINEsearchwasconductedtoidentifystudiespublishedfromJanuary1999toMarch2004thatcom-paredinjectablecalciumphosphatebone(NorianSRS)cementwithconventionaltreatmentindistalradialfrac-tures.Fromalistof13articlesidentifiedfromthesearchstrategy,fourarticleswe…     

Nasal septum lesions caused by chromium exposure among chromium electroplating workers

A chromium electroplating worker, suffering from epistaxis during work, was found to have nasal septum perforation. To determine the etiology and prevalence of nasal septum lesions, we conducted a survey of seven chromium electroplating factories and examined 79 workers. Forty workers from three aluminum electroplating factories were also enrolled as the reference group. Subjects were thoroughly examined by an otolaryngologist and each of them provided a blood and urine sample. A questionnaire interview regarding symptoms of the upper respiratory tract, past medical history, life style, and work history was also conducted. Air chromium concentrations were measured by taking area samples for 4–6 hours. Based on field observation and chromium measurements, we divided chromium electroplating into three different exposure zones: workers directly dealing with electroplating tanks (n = 31), other process workers (n = 29), and office workers and drivers (n = 19). Among the 79 chromium electroplating workers, there were 16 cases of nasal septum perforation, and 42 with either scar formation or ulceration; 10 chromium electroplating workers developed skin ulcers after performing chrome plating. No workers from aluminum electroplating factories had any nasal septum or skin abnormalities. There was a consistent trend between the degree of chromium exposure and the signs and symptoms related to the nose, throat, and skin. Immediate improvement of occupational hygiene is warranted.     

ADJUSTABLE SUTURES IN STRABISMUS SURGERY: A PERSONAL SERIES OF CASES

A personal series of 77 separate primary adjustable suture procedures performed on 69 patients is analysed. Adjustable suture surgery was performed on patients over ten years of age undergoing rectus muscle surgery, and a few selected younger patients. The ages ranged from 7 to 74 years. A 24-month-old infant who had a two-stage-anaesthesia is included in the series.
Thirty-eight of the 69 patients were reoperations. Of the 77 primary procedures, 48 (62.3%) required postoperative adjustment; 29 (37.7%) were tied down without adjustment.
Sixty-two of the 69 patients (89.8%) achieved a "cure". A further four patients (5.8%) were initially in desired alignment, but deteriorated within the follow-up period. Three of these were successfully reoperated. Of the three primary failures (4.4 %) two were reoperated with one achieving orthophoria.
Apart from alignment failure in the primary procedure, complications were minimal. Current follow-up periods range from one to 24 months.     

A breathing lung phantom for 81mKr lung ventilation studies its use in dosimetry and quality control

The construction of a breathing lung phantom that can be used to measure the amount of radioactive gas in the lungs as well as to determine the absorbed dose is described. For a lung ventilation study that consists of 6 views of 300 kents each, an effective dose equivalent of 50 Sv was calculated. The phantom is also suitable for comparison of different generator systems.     

Mechanical heart valve prostheses:: identification and evaluation (erratum)

Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons. It is essential for the practicing pathologist to be able to identify the prosthesis and be aware of some of its reported complications and modes of failure. This article, and a second one on bioprosthetic heart valves, is designed as a ready reference guide to heart valve prostheses, their important identifying features, their common complications, and modes of failure. It should help in the accurate identification of explanted prosthetic valves and more definitive reports. This accuracy of identification as well as tracking of abnormalities noted will, we hope, permit the identification of new failure modes and the recording of causes of failure of new (or even modified) prosthetic heart valves.     

微机控制的韧带动态力学特性测试系统

本系统是为自动测试人体韧带或类似组织的动态力学特性试验而研制的。在试验时,受控的加载过程和数据采集过程同时进行。系统向韧带试件提供一个快速的匀速可控的拉伸载荷,模拟人体剧烈运动的实况,同时实时采集力和变形的数据。系统还提供对所采集数据的分析手段,从而得到力、变形、应力、应变、弹性模量和变形能等参数之间的关系,并可以图形和文字形式输出。系统亦可将各数据文件转换为其它应用软件包可接受的形式,以便利用标准商品软件包的数据和图象处理能力。系统采用菜单提示的人机对话方式进行监控。     

Patient-ventilator interaction: A general model for nonpassive mechanical ventilation

A general mathematical model for the dynamic behaviour of asingle-compartment respiratory system in response to an arbitraryapplied inspiratory airway pressure and arbitrary respiratorymuscle activity is investigated. The model is used to computeexplicit expressions for ventilation and pressure variablesof clinical interest for clinician-selected and impedance-determinedinputs. The outcome variables include tidal volume, end-expiratorypressure, minute ventilation, mean alveolar pressure, averagepleural pressure, as well as the work performed by the ventilatorand the respiratory muscles. It is also demonstrated that undersuitable conditions, there is a flow reversal that can occurduring inspiration.