Nd∶YAG激光防治根管治疗期间急症发生的效果分析

目的分析激光消毒根管,防治根管治疗期间急症(endodonticinterappointmentemergencies,EIAE)发生的效果。方法慢性根尖周炎、慢性牙髓炎、牙髓坏死患者189例,随机分为激光组94例和对照组95例。激光组用激光消毒根管后一次性完成根管治疗;对照组直接行一次性完成根管治疗。对激光防治EIAE的效果进行临床评估。结果EIAE的发生率激光组为9.6%,对照组为35.8%,两组比较差异有显著意义(P<0.01)。结论运用激光消毒根管能有效地预防和降低根管治疗期间急症的发生。     

准分子激光原位角膜磨镶术治疗儿童远视性屈光参差

目的 评价准分子激光原位角膜磨镶术(excimer laser in situ keratomileusis,LASIK)治疗儿童远视性屈光参差的疗效.方法 使用美国Summit公司的SVS Apex plus准分子激光系统及Moria公司的微型板层角膜切割系统(LSK),对8例9～14岁远视性屈光参差患者进行LASIK手术,术后进行双眼视训练和系统的弱视治疗.结果 术后裸眼视力和矫正视力明显提高,术前平均最佳矫正视力0.23,术后6个月平均最佳矫正视力0.65;屈光度明显降低,但平均仍残留 2.81D;8例患者全部建立同时视和融合功能,6例有立体视功能.结论 LASIK治疗儿童远视性屈光参差安全有效,可明显提高视力,恢复和建立双眼视功能.     

Economic appraisal of laser applications in health care. Report of a project

This article reports on the results of a project evaluating effectiveness and cost-effectiveness of laser applications in health care. The literature was collected, emphasizing well-designed clinical trials and cost-effectiveness analyses. Few randomized clinical trials (RCTs) have been done outside the specialty of ophthalmology. Even fewer cost-effectiveness studies have been done, despite the frequent claims of cost-effectiveness in the medical literature. Review papers were commissioned, and a group of laser experts, economists, and policy-analysts met for 2 days to discuss the policy implications of lasers. The main conclusion from the conference is that inappropriate and unskilled use of lasers is presently the greatest problem with their application in health care.     

低强度激光对兔实验性牙齿移动牙槽骨组织中骨钙素水平变化的影响

目的观察低强度激光照射对兔实验性牙齿移动牙槽骨组织中骨钙素水平变化的影响。方法30只雄性大耳白兔,随机分为1、3、5、7、14和21d组,共6组,每组5只。在兔左右上颌第一磨牙与上颌切牙之间放置不锈钢闭合螺旋弹簧,牵引第一、二磨牙向近中移动。右侧为实验侧,以2.5J/cm2的He-Ne激光和514J/cm2的CO2激光同时照射。左侧为对照侧,不照射激光。拔除上颌第一磨牙,分别取其近、远中牙槽骨组织(根上2/3处),以放射免疫法检测牙槽骨组织中的骨钙素含量。结果低强度激光照射侧张力区骨钙素含量在施力1、3、5d组高于对照侧(P<0.05);压力区骨钙素含量以施力7d组最高,3、5d组照射侧骨钙素含量低于对照侧(P<0.05)。结论骨钙素在实验性正畸牙齿移动过程中参与了破骨与成骨活动,低强度激光照射可影响正畸牙周组织中骨钙素水平的变化,对正畸牙周组织的骨改建有促进作用。     

Laser-generated acoustic emission in urological and arterial surgery

Acoustic emission from renal calculi irradiated by a pulsed dye laser was observed in vivo and investigated in vitro. A number of acoustic frequency spectra were recorded from laser exposure of ureteric calculi, calcified arterial wall and bladder tissue. Although differences were observed between spectra, these did not depend on target material. Investigations with model targets suggested that variations in acoustic emission were caused by fluctuations in the strength of the laser plasma, due to changes in the local surface absorption of laser light, and by alterations in the relative orientation of laser fibre, target and transducer. Interaction between lasers and stones is reviewed and discussed.     

低强度激光照射诱导大鼠胸主动脉金属硫蛋白的生成

目的：观察低强度红激光照射对大鼠脑主动脉金属硫蛋白（metallothionein,MT)生成的影响，探讨激光照射的细胞保护机制。方法：取24只大鼠的胸主动脉，将其制成厚度为0．5mm的薄片，置于含10％胎牛血清Krebs-Henseleit液6孔培养板，经95％O2－5％CO2、37℃孵育。设对照组及3个实验组，对照组不照射激光，3个实验组分别以功率密度为3、6和12J／cm^2的632nm波长的激光照射。采用竞争性RT－PCR法测定胸主动脉内MT的mRNA水平变化，以^109Cd牛血红蛋白饱和法测定MT的含量。结果：3个实验组MT1 mRNA水平分别比对照组增加175％（P＞0.05)、418．6％（P＜0．05）和668．2％（P＜0．01）；MT2 mRNA水平分别比对照组增加163．9（P＞0．05）、615％、（P＜0．01）和1087％（P＜0．01）；相应的MT蛋白含量分别比对照组增加142．8％（P＜0．05）、170．8％（P＜0．05）和142．1％（P＜0．05）。     

Endoscopic laser pancreatic cystogastrostomy

Traditionally the drainage of pancreatic pseudocysts has been carried out operatively, forming a cystenterostomy. A simple endoscopic method of forming a pancreatic cystogastrostomy with laser is presented. This procedure does not require a general anesthetic, is safe, and allows resolution of symptoms.     

585nm脉冲染料激光治疗皮肤血管异常性疾病的副作用及相关因素分析

目的观察585nm脉冲染料激光治疗皮肤血管异常性疾病的副作用及相关因素。方法回顾性分析500例患者经585nm脉冲染料激光治疗后的副作用及与疾病种类、治疗次数、治疗能量的关系。结果500例患者中术后>1个月发生副作用者66例(13.2%),其中色素沉着35例(7.0%),色素减退12例(2.4%),萎缩性瘢痕17例(3.4%),增生性瘢痕2例(0.4%)。术后>6个月仍有皮肤异常者24例(4.8%),其中色素沉着7例(1.4%),色素减退2例(0.4%),萎缩性瘢痕13例(2.6%),增生性瘢痕2例(0.4%)。色素沉着、色素减退、萎缩性瘢痕发生率在激光能量密度≥8.0J/cm2级高于其他能量级,差异有显著意义(P<0.05)。草莓状血管瘤组萎缩性瘢痕发生率高于其他病种组,差异有显著意义(P<0.05)。结论出现副作用与治疗次数无关,与激光能量密度、疾病种类有关。585nm脉冲染料激光治疗皮肤血管异常性疾病是安全的,无连续激光治疗后引起的增生性瘢痕、持续性色素沉着等副作用。     

A small angle light scattering device for planar connective tissue microstructural analysis

The planar fibrous connective tissues of the body are composed of a dense extracellular network of collagen and elastin fibers embedded in a ground matrix, and thus can be thought of as biocomposites. Thus, the quantification of fiber architecture is an important step in developing an understanding of the mechanics of planar tissues in health and disease. We have used small angle light scattering (SALS) to map the gross fiber orientation of several soft membrane connective tissues. However, the device and analysis methods used in these studies required extensive manual intervention and were unsuitable for largescale fiber architectural mapping studies. We have developed an improved SALS device that allows for rapid data acquisition, automated high spatial resolution specimen positioning, and new analysis methods suitable for large-scale mapping studies. Extensive validation experiments revealed that the SALS device can accurately measure fiber orientation for up to a tissue thickness of at least 500 μm to an angular resolution of∼1^o and a spatial resolution of±254 μm. To demonstrate the new device’s capabilities, structural measurements from porcine aortic valve leaflets are presented. Results indicate that the new SALS device provides an accurate method for rapid quantification of the gross fiber structure of planar connective tissues.