A comparative study of the effects of laser and light-emitting diode irradiation on the wound healing and functional activity of wound exudate leukocytes

The effects of coherent He-Ne laser and non-coherent light-emitting diode radiation on rat skin wound healing and functional activity of wound excudate leukocytes were compared. A comparative pathomorphological analysis showed that the He-Ne laser and light-emitting diode irradiation stimulated the transition of the inflammatory phase of the wound healing into the reparative (proliferative) and scarring phases sequentially. It was also detected that the functional activity of leucocytes changed in a dose-dependent manner. The leukocyte activity was found to be similar in the groups with laser and light-emitting diode irradiation. Thus, we can conclude that coherent laser and non-coherent light-emitting diode radiation have very close effects on wound healing and activity of wound exudate leukocytes, and coherence is not required for this activity.     

激光辐照洋葱L1代的生理效应研究

采用ＣＯ２和Ｈｅ－Ｎｅ两种激光的三种剂量,分别辐照两个洋葱品种的湿种子,采用生理生化的方法,从过氧化氢酶、叶绿素、总糖总量等三个方面考查研究洋葱Ｌ１各处理的生物学效应。结果表明：Ｈｅ－Ｎｅ激光辐照洋葱Ｌ１代的过氧化氢酶、叶绿素、总糖含量的变异大于ＣＯ２激光辐照,可作为激光诱导变洋葱育种参考。     

Critical evaluation of indications for the holmium:YAG laser and the neodymium:YAG laser in orthopedic surgery based on an in vitro study]

This is an in vitro study of the biophysical effects of holmium:YAG and neodymium-YAG lasers that was prompted by the poor clinical results obtained with lumbar percutaneous laser discus decompression (PLDD). In the absence of adequate cooling, ablation of tissue with the holmium:YAG laser causes thermal damage to the surrounding tissues. Utilizing the immediate colour-independent laser coupling effect, the holmium:YAG laser removes soft and hard tissue immediately. The low tissue penetrating power (max. 0.32 mm), together with the use of irrigation, avoids thermal problems, and this laser type with its high pulse energy and frequency is to be recommended for arthroscopic surgery. In contrast, the effects of the neodymium:YAG laser are highly dependent on tissue colour. Using this laser on light-coloured tissue only diffuse warming but no ablation of soft tissue was often seen. The depth of tissue penetration seen in our study was 0.58 mm, but is greatly dependent on the duration of application, and is much larger with long application times. In conclusion, we believe that the neodymium:YAG laser is more suitable for percutaneous intradiscal procedures than the holmium:YAG laser. For arthroscopic surgery, the holmium:YAG laser will be the better choice. The effect of each type of laser depends not only on its physical properties, but also on tissue properties (light or dark-coloured, thermal conductivity) and duration of application.     

激光诱变洋葱生理效应研究Ⅱ

采用CO2和He-Ne两种激光的三种剂量,分别辐照两个洋葱品种的湿种子,采用生理生化的方法,从净同化率,净光合速率,呼吸速率,蛋白质含量等四个方面研究洋葱各处理的生物学效应。结果表明：He-Ne激光辐照洋葱的净同化率,净光合速率,呼吸速率,蛋白质含量的变异大于CO2激光辐照,采用He-Ne激光辐照洋葱容易从其变异后代中选择出高产,优质的优良变异株,进而育成符合育种目标的优良新品种。     

低强度激光鼻腔照射对血脂异常作用的研究

目的：观察低强度激光（650nm／5mw）鼻腔照射疗法对血脂异常的作用。方法：30例原发性血脂异常患者随机分为两组,分别接受药物（舒降之）治疗和低强度激光鼻腔照射疗法,测定治疗前后的血脂水平。结果：在调整饮食的基础上,低强度激光经鼻腔照射使病人的血清总胆固醇水平降低了5．8％（P=0．031）,甘油三酯降低了8．8％;低强度激光鼻腔照射在有效调整血脂的同时,使谷丙转氨酶（J唧）水平下降了23．1％（P=0．022）,对肝功能具有保护作用。结论：与舒降之相比,低强度激光鼻腔照射疗法的调脂效果虽然相对较弱,但基于安全性的考虑,在饮食控制无效或肝功能异常的病人中使用低强度激光鼻腔照射仍然具有一定的应用价值。     

高频激光-DNA分子相互作用体系相空间的局域特征

利用激光与DNA分子相互作用的动力学模型,借助适当的数值方法,讨论了系统动力学演化及相空间特性。结果表明：高频激光可使DNA分子的运动状态发生变化;特别地,相空间分析表明,高频激光的作用会使DNA分子运动在一些特定状态之间转变。从而可说明高频激光作用下DNA分子呈现新的有序运动现象。     

低能量激光照射对小鼠脾脏NK细胞活性影响的试验研究

目的：研究能量激光照射对小鼠NK细胞活性的影响,以便从NK细胞活性的角度阐明其免疫调节效应。方法：以BALB／c小鼠为研究对象,应用7.337J/cm^2,11．00J/cm^2,14．67J/cm^2,22．00J/cm^2和36．67J/cm^2五种剂量的氦氖激光作小鼠内眼角照射,连续照射8d,并于照射开始后第3d,6d,9d,13d和第17d,动脉监测实验鼠脾脏NK细胞活性。结果：以日剂量为7.33J/cm^2,11.00J/cm^2,14.67J/cm^2和22.00J/cm^2LELI照射小鼠四个剂量组均可增强NL细胞的活性（P＜0．01或P＜0．05）,但其峰值的出现随着LELI剂量的增大而加快,22．00J/cm^2剂量组在第3d就达到峰值,而其余三组则分别在第9d或第13d时达到峰值,与相相反,大剂量36.6J/cm^2ELEI组NK活性则表现出明显的抑制效应。结论：适当剂量的低能量激光照射剂可对小鼠脾脏NK细胞活性产生增强效应,而过大剂是LELI则产生抑制效应。     

激光辐照洋葱种子的生物学效应初探

采用Ｈｅ－Ｎｅ激光和ＣＯ２激光辐照洋葱两个品种的湿种子,采用随机区组设计,重复３次,利用生物统计学的方法,从个体水平上初步考查诱变Ｌ１代的生物学效应。结果表明：在出苗率、苗高、叶数、须根长、须根数、苗重、须根重等性状表现出不同处理所引起的生物学效应差异,激光种类不同,引起须根长的变异达到５％的显著差异,激光剂量不同引起须根数变异显著,苗高和苗重的变异达到极显著。     

Effects of helium-neon laser on physico-chemical properties of the bile

The influence of helium-neon laser radiation on bile physico-chemical characteristics in healthy subjects and in patients with the physico-chemical stage of gallstone disease was studied in vitro. This type of laser was found to induce positive therapeutic effects, such as: correction of hydrogen ion concentrations, surface tension and viscosity decrease and prolonged bile nucleation in patients with gallstone disease.     

Effect of the He-Ne laser irradiation on resistance of the isolated heart to the ischemic and reperfusion injury

The aim of this work was to investigate the myocardial protection against ischemia/reperfusion using low level laser irradiation (LLLI). It has been shown that pulse pressure was higher in the period of post-ischemic reperfusion as compared with the control group. It provided a better restoration of myocardial contractility as well as increasing of coronary flow in the reperfusion period. The amount of ventricular rhythm disorder episodes decreased. These effects of laser application were registered in conditions of coronary flow reduction less than 50%. One of the suggested mechanisms of laser effect is an ATP-sensitive channel activation.     

Laser pyrolysis products-genotoxic, clastogenic and mutagenic effects of the particulate aerosol fractions

Laser therapy has gained wide acceptance and application in many medical disciplines. Nevertheless, during surgical procedures, the thermal destruction of tissue creates a smoke plume. Recent research data indicate that pyrolysates liberated during vaporisation of tissue induce DNA damage. However, assessing potential health hazards during medical laser treatment requires comprehensive insight into the cytotoxic, genotoxic, clastogenic and mutagenic capacity of laser pyrolysis products (LPP). Therefore, the aim of this study was to evaluate the cytotoxic, genotoxic, clastogenic and mutagenic potential of substances resulting from laser irradiation. Four different types of porcine tissues were irradiated with a surgical CO2 laser, the aerosols were sampled under defined conditions and subjected to the SCE test, micronucleus test and the HPRT test. The results showed that the pyrolysis products are strong inducers of cytotoxic effects. The pyrolysis products induced positive effects in the SCE test, micronucleus test and the HPRT test. The ability and extent to induce genotoxic and mutagenic effects turned out to be dependent on the type of tissue that had been irradiated. In general, the effects were most pronounced with liver pyrolysate. In all test systems, a clear dose relationship could be established. In conclusion, we were able to prove that the particulate fraction of laser pyrolysis aerosols originating from biological tissues undoubtedly have to be classified as cytotoxic, genotoxic, clastogenic and mutagenic. Therefore, they could be potential health hazards for humans.     

He-Ne激光对大鼠离体颈上神经节后神经元膜电导的影响

应用细胞内生物电记录技术 ,观测不同功率、不同照射时间的 He- Ne激光 (脉冲频率 1Hz)对大鼠离体颈上神经节后神经元快兴奋性突触后电位 (f- EPSP)期间膜电导的影响。功率密度为 2 m W/ cm2 的 He- Ne激光在照射初期 (1min～ 2 min)引起快兴奋性突触后电位 (f- EPSP)幅值增大 ,同时膜电导增大 ;而在激光照射后期 (后 3m in～8m in)引起节后神经元膜电导减少。功率密度为 5 m W/ cm2 的 He- Ne激光照射期膜电导无明显变化 .结果表明 :功率密度为 2 m W/ cm2 的 He- Ne激光照射初期引起膜电导 (Gl=34.6± 5 .4 n S)较照射前 (Gf=2 6 .8± 6 .2 n S)有明显增大 (P<0 .0 5 ) ,照射后期膜电导减少。提示 :He- Ne激光照射可能是通过两时相效应改变节后神经元膜电导来影响交感神经节内兴奋传递过程。这可能是低功率激光对神经细胞的一种作用机制。     

Cell wall reconstruction and DNA damage repair play a key role in the improved salt tolerance effects of He-Ne laser irradiation in tall fescue seedlings

The improved salt tolerance effects of He–Ne laser were further studied through the estimation of ROS levels, cell viability, DNA damage phenomena, physicochemical properties, and monosaccharide compositions of cell wall polysaccharides in tall fescue seedlings. Salt stress produced deleterious effects on seedlings growth and development. ROS levels and genomic DNA damage were markedly increased compared with controls. Physicochemical activities and monosaccharide proportions of cell wall polysaccharide were also pronouncedly altered. He–Ne laser irradiation improved plant growth retardation via increasing cell viability and reverting physicochemical parameters. According to the results of Fourier transform infrared (FTIR) scanning spectra and DNA apopladder analysis, He–Ne laser was showed to efficiently ameliorate cell wall polysaccharide damage and DNA fragmentation phenomena. The treatment with DNA synthesis inhibitor further demonstrated that DNA damage repair was correlated with the improvement effects of the laser. Therefore, our data illustrated that He–Ne laser irradiation resulted in cell wall reconstruction and genomic DNA injury repair in vivo in salt-stressed seedlings, then enhanced salt tolerance probably via interactions between plant cell wall and related resistance gene expression pattern.     

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。     

低强度激光的生物效应对组织修复的影响

本文概述了近几年低强度激光照射疗法对促进骨骼肌的再生、关节炎与骨折的修复、改善心肌微循环等方面生物效应的实验研究的新进展,其结果表明低强度激光照射组织具有显著的生物刺激作用和损伤后的修复功能。     

低强度激光生物效应机理研究

结合低强度激光生物效应研究的现状,对低强度激光生物效应机理研究的各种观点进行了归纳分析,提出了对低强度激光生物效应机理研究的一些初步思考,把低强度激光生物效应的一般过程归纳为：激光（辐射)→初始光受体→信号传导与放大→生物效应。并指出探讨低强度激光生物效应机理,应着重于寻找并研究初始光受体与激光的相互作用,以及随后的信号传导与放大过程。     

Comparison of the effects of laser and light-emitting diodes on lipid peroxidation in rat wound exudate

The effect of laser and light-emitting diode radiation on lipid peroxidation in rat wound exudate was studied with the aim to compare the efficiency of coherent laser and incoherent light-emitting diode radiations. A model of aseptic wound in rat suggested by L.I. Slutskii was used. A He-Ne laser (632 nm) and a U-332B light-emitting diode were used in this study. The intensity of lipid peroxidation was estimated by the TBA assay. The antioxidative capacity of rat wound fluid was evaluated by means of chemiluminescent assays in two model systems: a) aqueous system with ABAP and luminol and b) in phospholipid liposome suspension with Fe2+ and cumarin. It was shown that exposure of rat wounds to both laser and light-emitting diode radiation decreased the concentration of TBA products and increased the antioxidative capacity of wound exudates, compared with the control group (without irradiation). The results obtained show that exposure of wounds to both laser and light-emitting diode irradiation causes a decrease in the oxidative stress in the rat wound fluid. No significant quantitative difference between the effects of laser and light-emitting diode irradiation was found.     

激光对DNA作用机理的AFM研究

激光作用质粒DNA和小牛胸腺DNA产生损伤效应,导致DNA结构变化,利用一种改进的试样制备过程和纳米显微镜－－原子力显微镜（AFM）能够获得可重现的激光作用质粒DNA和小牛胸腺DNA的AFM图像,显示它们的特殊的表达结构,讨论了激光辐照导致DNA链断裂的作用机理。     

Light and scanning electron microscopic studies of the effects of CO2 laser on the palatine mucosa of rats

In order to verify the effects of CO2 laser on the palatine mucosa of rats, 15 animals were utilized. The animals were anaesthetized with thionembutal by intra-peritoneal injection and the palatine mucosa of each animal was irradiated with a single pulse of 10 W. The results showed that immediately after the irradiation of CO2 laser, the formation of small cavities is observed. The wound healing post operationem is gradually in 1 week. The region is totally occupied by neoformed connective tissue and epithelial cells. Numerous polymorphonuclear cells and fibroblasts may be seen between the neoformed collagen fibres.     

Ultrafast Mid-IR Laser Scalpel: Protein Signals of the Fundamental Limits to Minimally Invasive Surgery

Lasers have in principle the capability to cut at the level of a single cell, the fundamental limit to minimally invasive procedures and restructuring biological tissues. To date, this limit has not been achieved due to collateral damage on the macroscale that arises from thermal and shock wave induced collateral damage of surrounding tissue. Here, we report on a novel concept using a specifically designed Picosecond IR Laser (PIRL) that selectively energizes water molecules in the tissue to drive ablation or cutting process faster than thermal exchange of energy and shock wave propagation, without plasma formation or ionizing radiation effects. The targeted laser process imparts the least amount of energy in the remaining tissue without any of the deleterious photochemical or photothermal effects that accompanies other laser wavelengths and pulse parameters. Full thickness incisional and excisional wounds were generated in CD1 mice using the Picosecond IR Laser, a conventional surgical laser (DELight Er:YAG) or mechanical surgical tools. Transmission and scanning electron microscopy showed that the PIRL laser produced minimal tissue ablation with less damage of surrounding tissues than wounds formed using the other modalities. The width of scars formed by wounds made by the PIRL laser were half that of the scars produced using either a conventional surgical laser or a scalpel. Aniline blue staining showed higher levels of collagen in the early stage of the wounds produced using the PIRL laser, suggesting that these wounds mature faster. There were more viable cells extracted from skin using the PIRL laser, suggesting less cellular damage. β-catenin and TGF-β signalling, which are activated during the proliferative phase of wound healing, and whose level of activation correlates with the size of wounds was lower in wounds generated by the PIRL system. Wounds created with the PIRL systsem also showed a lower rate of cell proliferation. Direct comparison of wound healing responses to a conventional surgical laser, and standard mechanical instruments shows far less damage and near absence of scar formation by using PIRL laser. This new laser source appears to have achieved the long held promise of lasers in minimally invasive surgery.