基于光学相干层析成像技术的皮肤组织非消融性光热损伤过程

使用OCT技术观察活体小鼠皮肤组织在非消融性激光作用后光热损伤及其修复过程,得出皮肤组织在此过程中形态卜的变化规律.利用OCT散射模型得出皮肤在激光作用前后光学参数中衰减系数的变化,根据所获得的光学参数的变化量来判断热损伤程度,并分析引起散射参数变化的原因,作为临床上无损的判断光热作用下皮肤内部损伤情况的依据.结果表明OCT是一种很有潜力的活体监测光热损伤及其修复过程的工具.     

激光蚀除和选择性光热解在治疗皮肤病中的光热作用研究

目的:探究皮肤病中应用选择性光热解与激光蚀除的光热作用。方法:将我校第三附属医院2014年6月至2015年3月接收的皮肤病患者40例作为研究对象,按数字奇偶法随机分为对照组与治疗组,各20例,对照组应用激光蚀除治疗,治疗组应用激光蚀除加选择性光热解治疗;分析激光蚀除联合选择性光热解治疗皮肤病的光热作用,观察其对皮肤病患者的治疗效果。结果:治疗组治疗疗效为95.00%,对照组治疗疗效为80.00%,组间比较,差异具有统计学意义(p0.05)。结论:激光蚀除与选择性光热解在治疗皮肤病中疗效显著,通过对组织温度分布选择性的强化,能够使选择性光热解治疗效果优化。     

Q开关Nd:YAG 1064nm和532nm激光对犬心肌切割作用的研究

目的 :研究 10 64nm和 53 2nm波长激光在激光能量为 14 0mJ/pulse(脉冲 )时对犬心肌切割效率。方法 :用Q开关Nd :YAG 10 64和 53 2nm波长脉冲激光分别照射犬离体和在体心肌组织 ,光学显微镜和偏振光学显微镜行组织学分析 ,观察不同条件下激光切割组织的深度和光热对组织的损伤。结果 :离体和在体实验 ,10 64nm波长激光的切割效率高于 53 2nm(p <0 .0 1)。在体和离体实验显示 10 64nm激光能量和重复率相同时 ,所致的切割效率无明显差异 (p >0 .0 5) ,血液对 10 64nm激光的切割效率影响较小。相反 ,在 53 2nm时血液对其影响较大 ,相同的激光能量和重复率 ,离体实验切割效率高于在体 (p <0 .0 1)。 10 64nm激光所致的光热和机械损伤均轻于 53 2nm激光。结论 :在切割效率方面 ,10 64nm激光比 53 2nm更适用于TMLR。 10 64nmQ开关Nd :YAG激光可通过光导纤维传输 ,是TMLR的一个有潜力的激光源     

国产Nd:YAP激光组织热损伤效应的比较研究

目的:通过比较1 341 nm Nd:YAP与临床常用激光器脉冲Nd:YAG和连续Nd:YAG对皮肤、肌肉、静脉和肝脏组织的热损伤效应,了解Nd:YAP激光的作用特点,为其临床应用提供实验依据。方法:以大鼠作为实验对象,分为皮肤、肌肉组和静脉、肝脏组。皮肤、肌肉组:Nd:YAP激光、连续和脉冲Nd:YAG选择能量密度1000 J/cm2、2 000 J/cm2,静脉、肝脏组采用Nd:YAP激光和连续Nd:YAG两种激光器,能量密度选择500 J/cm2和1 000 J/cm2,对组织进行非接触式点状照射。照射过程中观察组织变化和损伤直径大小,并于照射后即刻、3天取材做病理切片,光镜下观察病理变化,比较相同能量密度下三种激光器对组织的热损伤和损伤修复情况。结果:皮肤、肌肉组:Nd:YAP激光在1 000 J/cm2条件下对组织的损伤以热凝固效应为主,2 000 J/cm2条件下组织发生明显气化、有一定的切割作用。相同能量密度下,脉冲Nd:YAP激光气化作用较两种Nd:YAG激光显著,而凝固损伤范围较连续Nd:YAG浅,较脉冲Nd:YAG深。肝脏、静脉组:Nd:YAP激光对肝脏的热凝固效应与Nd:YAG激光近似,气化作用明显;Nd:YAP激光对血管及其周围组织的凝固及气化作用均较连续Nd:YAG激光明显。结论:Nd:YAP激光具有良好的凝固与气化作用。     

基于动态光热作用模型的激光诱导肿瘤间质热疗中的参数选择

建立了描述温控加热方式下激光诱导肿瘤间质热疗过程中动态光热作用的二维圆柱坐标下的数学模型,采用基于网格的蒙特卡罗方法数值模拟热疗过程中激光能量在非均质生物组织内的传输过程,基于Pennes生物传热方程和Arrhen ius方程数值求解组织内的温度场和热损伤体积的变化。通过数值模拟的方法分析了激光波长、激光功率、温控范围等因素对激光诱导肿瘤间质热疗中热损伤体积的影响。数值模拟的结果表明,通过选择合适的治疗参数,可以得到各种不同大小的热疗区域。本文的结果和结论对于临床治疗方案的制定具有一定的理论指导意义。     

强激光作用下生物组织光致破裂效应的研究

基于激光与生物组织作用时产生的光致破裂效应,利用脉冲激光直接聚焦于孕囊内的胚胎内部,激光产生的光致破裂效应对胚胎心脏造成损伤,造成胚胎的快速死亡,初步证明利用激光进行减胎手术有望成为一种新方法。采用输出波长1 064 nm、脉宽8 ns、单脉冲能量60～96 mJ可调的脉冲激光作用于牛肌肉组织样品,并用光学相干层析成像(OCT)系统测量实验样品的损伤直径和损伤深度,建立了不同的激光参数与被作用样品的损伤直径及损伤深度之间的关系。得出结论:样品的损伤深度和损伤直径与激光的脉冲能量成正相关关系,而与激光的脉冲频率成负相关关系。这对于激光应用于减胎手术时参数的优化和精确控制起到一定的指导作用。     

皮肤的光学模型

基于人体皮肤的组织结构,光在皮肤组织中的传输特性以及皮肤各层的组织光学参数,建立了正常皮肤的光学模型,介绍了该模型中的组织光学参数的确定方法。本文建立的皮肤组织光学模型及其方法,可应用于皮肤光学基础与临床的其它研究中。     

532 nm和808 nm激光及其线偏振激光辐照人正常膀胱与膀胱癌组织光学特性

采用双积分球系统和光辐射测量技术的基本原理 ,以及运用生物组织的光学模型 ,研究了 5 32nm和80 8nm激光及其线偏振激光辐照人正常膀胱和膀胱癌组织的光学特性 .结果表明 :膀胱癌组织对同一波长的激光或其线偏振激光的衰减明显较正常膀胱组织的要大 ,膀胱癌组织对 5 32nm和 80 8nm激光的衰减均较其线偏振激光的要略大一些 .膀胱癌组织对 5 32nm和 80 8nm激光及其线偏振激光的衰减明显较正常膀胱组织的要大 .正常膀胱或膀胱癌组织对同一波长的激光及其线偏振激光的折射率均没有明显的差异 ,膀胱癌组织对 5 32nm和80 8nm激光的折射率比正常膀胱的明显要大 .Kubelka Munk二流模型下 ,两种组织对同一波长的激光或其线偏振激光的光学特性均有显著性差异 (P <0 0 1) .同一组织对不同波长的激光及其线偏振激光的光学特性也有显著性差异 (P <0 0 1) ,正常膀胱组织对同一波长的激光及其线偏振激光的光学性有明显差异 ,而膀胱癌组织对同一波长的激光及其线偏振激光的光学特性则没有明显差异 .膀胱癌组织对 5 32nm和 80 8nm激光及其线偏振激光的前向散射通量i (x)、后向散射通量 j (x)、总散射通量I (x)的衰减均较正常膀胱组织的明显要大得多 ,且其i (x)均明显较j (x)要强     

基于光学相干层析成像技术的小鼠表皮厚度的无损测量及分析

光学相干层析成像技术(optical coherence tomography,OCT)在研究活体皮肤的表皮和真皮上层方面是一种很有潜力的手段.本文以小白鼠为研究对象,脱毛后,采用OCT系统对同一部位的小鼠皮肤在制作切片过程中(活体、离体、固定24 h后)进行成像跟踪,分别获得OCT强度图中第一强度峰到第一个波谷,以及第一、二强度峰之间的距离,比较两种结果和组织学的对应情况,并分析其原因,同时关注切片过程中各种物理、化学因素对皮肤各层厚度的影响,研究了OCT图像的各个反射峰与实际皮肤的结构之间联系.     

激光和生物组织的光热作用及临床应用

激光和生物组织的光热作用机理及在临床上的应用作了全面的论述,同时建立了一个定量描述光热作用的模型。讨论了光热作用中热产生,传导及热效应。     

Evaluation of bone healing following Er:YAG laser ablation in rat calvaria compared with bur drilling

The Er:YAG laser is currently used for bone ablation. However, the effect of Er:YAG laser irradiation on bone healing remains unclear. The aim of this study was to investigate bone healing following ablation by laser irradiation as compared with bur drilling. Rat calvarial bone was ablated using Er:YAG laser or bur with water coolant. Er:YAG laser effectively ablated bone without major thermal changes. In vivo micro‐computed tomography analysis revealed that laser irradiation showed significantly higher bone repair ratios than bur drilling. Scanning electron microscope analysis showed more fibrin deposition on laser‐ablated bone surfaces. Microarray analysis followed by gene set enrichment analysis revealed that IL6/JAK/STAT3 signaling and inflammatory response gene sets were enriched in bur‐drilled bone at 6 hours, whereas the E2F targets gene set was enriched in laser‐irradiated bone. Additionally, Hspa1a and Dmp1 expressions were increased and Sost expression was decreased in laser‐irradiated bone compared with bur‐drilled bone. In granulation tissue formed after laser ablation, Alpl and Gblap expressions increased compared to bur‐drilled site. Immunohistochemistry showed that osteocalcin‐positive area was increased in the laser‐ablated site. These results suggest that Er:YAG laser might accelerate early new bone formation with advantageous surface changes and cellular responses for wound healing, compared with bur‐drilling.      

Efficacy and safety of long pulse 1064 and 2940 nm lasers in noninvasive lipolysis and skin tightening

Noninvasive body shaping is becoming a growing demand. The aim of this study was to investigate the efficacy and safety of the combined treatments of 1064 nm Nd:YAG and 2940 nm Er:YAG in noninvasive lipolysis and skin tightening. Ten females were enrolled, and all women's side of the waist or the lower part of the abdomen were treated. In the first step, the 1064 nm Nd:YAG was used. As a second step, the 2940 nm Er:YAG laser was applied. Each woman was treated four times, once every 2 weeks. The effects were determined by comparative photo documentation, waist circumference measurement, two‐dimensional B‐mode ultrasonography and low‐dose native computer tomography (CT), whereas body fat was monitored with bioelectric impedance. The tissue firmness was measured by ultrasound shear wave elastography. Combined laser treatment significantly reduced waist circumference and total body fat. Ultrasonography has revealed that the treatment considerably decreased fat thickness and improved skin stiffness in the treated region. Subcutaneous fat volume, measured by low‐dose CT, displayed a moderate decrease in the waist region. The combined 1064 nm Nd:YAG and 2940 nm Er:YAG laser treatment results in the reduction of fat tissue and tightens the skin as confirmed by objective measurements.      

Side effects and complications of variable-pulsed erbium:yttrium-aluminum-garnet laser skin resurfacing: extended experience with 50 patients

Recent advances in technology have provided laser surgeons with new options for cutaneous laser resurfacing. Despite its popularity, there is limited information on the short-term and long-term side effects and complications of variable-pulsed erbium:yttrium-aluminum-garnet (erbium:YAG) laser skin resurfacing. The purpose of this study was to prospectively evaluate postoperative wound healing, side effects, and complications of multiple-pass, variable-pulsed erbium:YAG laser skin resurfacing for facial photodamage, rhytides, and atrophic scarring. Fifty consecutive patients with facial photodamage, rhytides, or atrophic scarring were treated with a variable-pulsed erbium:YAG laser. Side effects and complications relating to postoperative healing, erythema, and pigmentary changes were tabulated. Patients were evaluated at postoperative days 3 through 7 and at 1, 3, 6, and 12 months after laser skin resurfacing. The average time for reepithelialization was 5.1 days. Prolonged erythema (>1 month) was observed in three patients (6 percent). Transient hyperpigmentation occurred in 20 patients (40 percent), with an average duration of 10.4 weeks. No cases of hypopigmentation or scarring were seen. In summary, a variable-pulsed erbium:YAG laser can safely be used for the treatment of facial photodamage, rhytides, and atrophic scarring. Although more postoperative erythema is seen after variable-pulsed erbium:YAG laser treatment than is usually produced with a short-pulsed erbium:YAG system, the side-effect profile and recovery period after variable-pulsed erbium:YAG laser skin resurfacing still are more favorable than after multiple-pass carbon dioxide laser skin resurfacing.     

Biological effects of Er:YAG laser irradiation on the proliferation of primary human gingival fibroblasts

We investigated the biological effects of Er:YAG laser (2940‐nm; DELight, HOYA ConBio, Fremont, California) irradiation at fluences of 3.6, 4.2, 4.9, 6.3, 8.1 or 9.7 J cm^?2 at 20 or 30 Hz for 20 or 30 seconds on primary human gingival fibroblasts (HGFs). Irradiation at 6.3 J cm^?2 promoted maximal cell proliferation, determined by WST‐8 assay and crystal violet staining, but was accompanied by lactate dehydrogenase release, on day 3 post‐irradiation. Elevation of ATP level, Ki67 staining, and cyclin‐A2 mRNA expression confirmed that Er:YAG affected the cell cycle and increased the number of proliferating cells. Transmission electron microscopy showed alterations of mitochondria and ribosomal endoplasmic reticulum (ER) at 3 hours post‐irradiation at 6.3 J cm^?2, and the changes subsided after 24 hours, suggesting transient cellular injury. Microarray analysis revealed up‐regulation of 21 genes involved in heat‐related biological responses and ER‐associated degradation. The mRNA expression of heat shock protein 70 family was increased, as validated by Real‐time PCR. Surface temperature measurement confirmed that 6.3 J cm^?2 generated heat (40.9°C post‐irradiation). Treatment with 40°C‐warmed medium increased proliferation. Laser‐induced proliferation was suppressed by inhibition of thermosensory transient receptor potential channels. Thus, despite causing transient cellular damage, Er:YAG laser irradiation at 6.3 J cm^?2 strongly potentiated HGF proliferation via photo‐thermal stress, suggesting potential wound‐healing benefit.      

Er,Cr:YSGG激光照射对牙根尖封闭效果影响的实验研究

目的:深入探讨在根尖倒充填术中Er,Cr:YSGG激光照射对牙根尖的封闭效果,为此激光在口腔临床上的应用与推广提供重要的理论与实验依据。方法:将56颗新拔除的单根牙随机分成7组,每组8颗牙。去除牙冠,常规进行根管预备、根管充填。将倒充填的牙根尖进行预备,然后银汞合金倒充填。预备方法:1手机切除根尖后,制备成烧瓶状洞形;2手机处理方法同1,然后Er,Cr:YSGG激光于不同能量(1W、2W)及不同方式(喷水或无水)下对洞内壁进行照射。结合微渗漏检测与扫描电镜观察对Er,Cr:YSGG激光照射后的牙根尖封闭效果进行评估。结果:Er,Cr:YSGG激光可有效去除根切面上的玷污层及碎屑;与手机加银汞倒充填组相比,激光照射后的根尖染料微渗漏深度有所减少;但只有1WEr,Cr:YSGG激光于无水条件下照射时,根尖染料微渗漏深度显著减少(P<0.05)。结论:Er,Cr:YSGG激光应用于根尖倒充填术中可减少微渗漏的发生;促进根尖封闭;在特定的能量参数下可获得优于常规银汞倒充填术的治疗效果。因此我们推荐临床上将Er,Cr:YSGG激光照射与常规银汞倒充填术结合使用,这将有助于提高根尖倒充填术治疗的成功率。     

Combined erbium:YAG laser resurfacing and face lifting

Facial aging occurs secondary to gravity-induced tissue ptosis and photoaging. Combined face lifting and carbon dioxide laser resurfacing provides a comprehensive one-stage approach to facial rejuvenation but is condemned by many plastic surgeons due to the nonspecific thermal effects of the laser and risk of skin necrosis. Newer high-energy erbium:YAG lasers allow precise tissue ablation with minimal thermal effect. In this study, various facial rejuvenation techniques were combined with simultaneous erbium:YAG laser resurfacing to assess results and complications. A total of 257 patients from Florida, Melbourne, Australia, and Tel Aviv, Israel, underwent combined erbium:YAG laser resurfacing and surgical facial rejuvenation. Various face-lift methods were used, including endoscopic, deep plane, and subcutaneous. Simultaneous, full-facial laser resurfacing was performed using a variety of erbium:YAG lasers. It was found that combined laser resurfacing and face lifting was successful in greater than 95 percent of patients with minimal morbidity. Two patients (1 percent) (both heavy smokers) developed small areas of skin necrosis that healed with minor pigment changes. Five patients (2 percent) developed synechia that was treated with no residual effect. Two additional patients (1 percent) developed temporary ectropion. There were no other cases of scarring, infection, or cosmetically obvious hypopigmentation. Although larger studies are necessary, it seems that the lack of thermal injury from the erbium:YAG laser makes it possible to safely perform laser resurfacing with surgical facial rejuvenation in nonsmokers. However, the authors caution that familiarity with the nuances of erbium:YAG laser resurfacing be obtained before performing combined laser resurfacing and face lifting.     

Er,Cr:YSGG激光照射对根管封闭效果影响的实验研究

探讨常规根管预备后使用不同能量参数Er,C r:YSGG激光进行根管内照射对根管封闭效果的影响,为此激光在根管治疗领域的临床应用提供重要的实验依据。选择新拔除的单根管牙80颗,分成4组,每组20颗牙。常规根管预备后,分别使用1 W、2 W、3 W Er,C r:YSGG激光于有水条件下进行根管内照射,另选一组不做任何处理,作为阴性对照。扫描电子显微镜下观察根管内壁形态学改变后,常规根管充填,检测根管微渗漏情况。采用单因素方差分析及q检验进行统计学处理。结果可见:(1)形态学观察:与对照组相比,激光照射均可有效去除根管内壁的玷污层及碎屑;牙本质小管口清晰可见;未见熔融及炭化等热损伤改变;其中3 W激光处理后根管内壁形态最为理想。(2)微渗漏检测:与对照组相比,各激光组根管微渗漏深度均显著减少(P<0.05);但各激光组间比较无显著性差异(P>0.05)。综上,使用Er,C r:YSGG激光进行根管内照射可达到较为理想的根管清洁目的,显著改善根管充填后的封闭效果,因此有望在临床上应用提高根管治疗的成功率。     

Comparison of tensile bond strengths of four one-bottle self-etching adhesive systems with Er:YAG laser-irradiated dentin

This study aimed to investigate the interaction of current one-bottle self-etching adhesives and Er:YAG laser with dentin using a tensile bond strength (TBS) test and scanning electron microscopy (SEM) in vitro. Two hundred and thirteen dentin discs were randomly distributed to the Control Group using bur cutting and to the Laser Group using an Er:YAG laser (200 mJ, VSP, 20 Hz). The following adhesives were investigated: one two-step total-etch adhesive [Prime & Bond NT (Dentsply)] and four one-step self-etch adhesives [G-Bond plus (GC), XENO V (Dentsply), iBond Self Etch (Heraeus) and Adper Easy One (3 M ESPE)]. Samples were restored with composite resin, and after 24-hour storage in distilled water, subjected to the TBS test. For morphological analysis, 12 dentin specimens were prepared for SEM. No significant differences were found between the control group and laser group (p = 0.899); dentin subjected to Prime & Bond NT, XENOV and Adper Easy One produced higher TBS. In conclusion, this study indicates that Er:YAG laser-prepared dentin can perform as well as bur on TBS, and some of the one-step one-bottle adhesives are comparable to the total-etch adhesives in TBS on dentin.     

脉冲Nd:YAG激光对单层KB细胞损伤效应的研究

目的：观察脉冲Nd：YAG激光照射体外单层培养KB细胞后的形态改变及损伤后HSP70,c-Fos的表达情况,初步探讨较强脉冲激光对细胞的损伤效应及损伤修复机制。方法：建立单层培养细胞的脉冲Nd：YAG激光损伤模型,每个脉冲能量密度为160J／cm^2～186J／cm^2或220J／cm^2～257J／cm^2,分别于照后即刻、2h和6h,用台盼蓝染色、TUNEL检测分析该激光对KB细胞的损伤特点,免疫组化法检测HSP70,c-Fos的表达水平。结果：当照射剂量为220J／ecm^2～257J／cm^2时,照后即刻,光斑中央细胞形态严重破坏,直接坏死;周围细胞形态未发生明显改变。2h后周围细胞TUNEL。着色也增强,呈强阳性。照后6h光斑中央及周围细胞着色均减弱。TUNEL着色区直径随时间先扩大后缩小。当照射剂量为160J／cm^2～186J／cm^2时,细胞内HSP70、c-Fos表达随时问先显著增强,而后减弱至正常。结论：脉冲Nd：YAG激光在所选剂量下,可以引起单层KB细胞的损伤,包括即刻坏死、延迟性死亡及可逆性损伤。HSP70、c-Fos的高表达说明它们在保护受损细胞、修复激光所致损伤中发挥重要作用。