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.     

A comparative study of the effects of laser and light-emitting diode radiation on superoxide dismutase activity and nitric oxide production in rat wound fluid

The effect of laser and light-emitting diode radiation in the visible region of the spectrum on the content of reactive nitrogen species and superoxide dismutase activity in rat wound fluid was studied. The efficiency of action of coherent laser radiation and incoherent light-emitting diode radiation in the red region of the spectrum on the parameters analyzed was compared. The study was performed using the model of cut aseptic wounds proposed by L.I. Slutskii. A He-Ne laser (632 nm) or an U-332B light-emitting diode (630 nm) was used as the source of radiation. It was shown that (1) exposure of wounds to visible light of both laser and light-emitting diode causes dose-dependent changes in superoxide dismutase activity and nitrite production and that (2) radiation coherence does not play a significant role in the changes in superoxide dismutase activity or nitric oxide production by wound fluid phagocytes.     

A comparison of the effects of laser and light-emitting diodes on superoxide dismutase activity and nitric oxide production in rat wound fluid

The action of laser and light-emitting diode radiation in the visible region on the content of reactive nitrogen species and activity of superoxide dismutase in rat wound fluid was studied, and efficiency of action of coherent laser and incoherent light emitting diode radiations in the red region of the spectrum on the parameters under study was compared. A model of incised aseptic wounds in rats proposed by L.I. Slutskiy was used. A He-Ne laser (632 nm) and a Y-332B light emitting diode served as radiation sources. It was shown that (1) exposure of wounds to the visible light of both laser and light-emitting diodes causes dose-dependent changes in superoxide dismutase activity and production of nitrites and (2) the radiation coherence does not play any significant role in the changes of superoxide dismutase activity or nitrogen oxide formation by wound fluid phagocytes.     

Effect of photosensitizers pheophorbide a and protoporphyrin IX on skin wound healing upon low-intensity laser irradiation

The effect of photosensitizer with subsequent He-Ne (632.8 nm; 3 mW/cm²) laser irradiation on experimental skin wound healing has been studied. Pheophorbide a and protoporphyrin IX were used as photosensitizers. It was found that application of the photosensitizer and subsequent laser irradiation, first, decreased the amount and the functional activity of leukocytes in the wound exudate and, second, inhibited the SOD activity as compared with that of the control group. Moreover, pheophorbide and protoporphyrin practically did not affect the total healing period but decreased the length of the inflammation stage. It was supposed that these effects are related to generation of reactive oxygen species during irradiation.     

A study of the effect of low-intensity laser radiation of the blue, green, and red spectral regions on the healing of experimental skin wounds in rats

The effect of low-intensity laser radiation of the blue (441.2 nm), green (532 nm), and red (632.8 nm) spectral regions on the healing of experimental skin wounds in rats has been studied. The effect of the traditionally applied laser radiation in the red region has been compared with the effect of laser radiation in the other spectral regions, assuming that, upon irradiation of wounds by lasers emitting in the blue and green regions, a similar effect can be achieved at lower doses. The following parameters characterizing the healing of experimental wounds were used: the functional activity of phagocytes of wound exudates, which was determined by luminol-dependent chemiluminescence, and their number; the antioxidant activity of wound exudates; and the rate of healing, which was determined as a change in the wound area. It was shown that irradiation with laser accelerated the healing of wounds in all cases. The exposure to laser radiations in the red (1.5 J/cm), blue, and green (0.75 J/cm2) spectral regions shortened the time of wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes after the exposure increased on day 5 after the infliction of the wound, whereas in the control it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after the operation. A maximum increase in the superoxide dismutase activity occurred after the exposure to laser radiation in the red region at a dose of 1.5 J/cm and in the blue and green spectral regions at a dose of 0.75 J/cm2.     

A comparative study of the effects of laser and LED radiation on lipid peroxidation in rat wound fluid

The effect of laser (632 nm) and LED (630 nm) on lipid peroxidation in rat wound fluid (exudate) was studied with the aim of comparing the efficiency of coherent and incoherent light on the processes that take place during wound healing. The study was performed using the model of cut aseptic wounds proposed by L.I. Slutskii. It was shown that irradiation of wounds with light of both laser and LED caused a decrease in the concentration of lipid peroxidation products in wound fluid as compared with the control group. An increase in the antioxidative activity of wound fluid was observed. It was concluded that irradiation with light of both laser and LED decreases the level of oxidative stress in wound fluid and that radiation coherence does not play a significant role.     

The effect of low-intensity laser irradiation in the blue, green, and red spectral ranges on healing of experimental skin wounds in rats

The effects of low-intensity laser irradiation in the red (632.8 nm), green (532 nm), and blue (441.2 nm) spectral ranges on wound healing has been studied in rats. The effect of the traditionally used red laser irradiation has been compared with the effect caused by laser irradiation in other spectral ranges, aiming to support the provisional hypothesis that a similar healing effect could be achieved at lower doses of wound irradiation by lasers emitting in the blue and green spectral ranges. The following parameters have been used to characterize healing of the experimental wounds: the functional activity of phagocytes in the wound exudate, which was determined from luminol-dependent chemiluminescence, the phagocyte number; the wound exudates’ antioxidant activity; and the rate of healing, which was determined as the change of the wound surface area. It was found that in all cases the laser irradiation accelerated the healing of wounds. Exposure to red laser irradiation at the dose of 1.5 J/cm²), and to blue or green laser irradiation at a dose of 0.75 J/cm² shortened the time of the wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes in irradiated groups increased by day 5 after surgery, whereas in the control group it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after surgery. Laser irradiation in the red spectral range at a dose of 1.5 J/cm² resulted in a larger increase in superoxide dismutase activity, as compared to that found after exposure to laser irradiation in the blue and green spectral ranges at a dose of 0.75 J/cm².     

The role of endogenous porphyrins in laser therapy of experimental skin wounds

The role of endogenous porphyrins in the effect of laser irradiation on the superoxide dismutase (SOD) activity of wound exudate and rat leukocyte activity has been studied on models of aseptic incised skin wounds. Wounds were irradiated with a He-Ne laser (632.8 nm, 1.5 J/cm²) on the 2nd, 3rd, and 4th days after the beginning of the experiment. Irradiation effects were evaluated by the SOD activity (NBT test) and the activity of leukocytes of the wound exudate (as a chemiluminescent response to opsonized zymosan). It was found that in animals subjected to laser irradiation, the SOD activity sharply increased. This effect depended on endogenous porphyrin concentration and was retained throughout the experiment. The SOD activity in unirradiated animals decreased from the 2nd to the 5th day of experiment. The evaluation of the activity of wound exudate leukocytes did not reveal any distinct dependence of the effect on the concentration of endogenous porphyrins.     

He—Ne激光辐照与UV-B辐射对小麦幼苗细胞器中Na^＋／K^＋-ATP酶活性的影响

分别采用5mJ·s^-1·mm^-2He-Ne激光辐照、10．08kJ·m·^-2,d^-1增强UV-B辐射及二者组合对小麦（Triticum aestivum）晋麦8号（Triticum aestivum‘Jinmai8’）幼苗进行处理。第5天开始测定各处理小麦幼苗叶片中线粒体、叶绿体及细胞溶质中Na^＋／K^＋-ATP酶活性的变化。结果表明,随着处理天数的增加,小麦幼苗叶片线粒体、叶绿体及细胞溶质中Na^＋／K^＋-ATP酶活性均在第6天下降,第7天升高,而后又逐渐下降。在处理的第7天,仅He—Ne激光辐照可使小麦幼苗叶片线粒体、叶绿体及细胞溶质中Na^＋／K^＋-ATP酶活性升高：增强UV-B辐射使各细胞器中Na^＋／K^＋-ATP酶活性下降：复合处理后小麦各细胞器中Na^＋／K^＋-ATP酶活性均高于UV-B单独辐射处理。实验结果表明,一定剂量的He-Ne激光辐照能够部分修复UV-B辐射对小麦幼苗细胞器中Na^＋／K^＋-ATP酶造成的损伤。     

低功率He-Ne激光照射下细胞内活性氧自由基的产生和游离Ca^2＋浓度的研究

在临床应用中,低功率He-Ne激光(632.8 nm)能促进骨骼肌修复,加速创伤愈合,降低牙齿的超敏感性,减缓疼痛等.大量研究表明:低功率He-Ne激光能调节细胞的众多行为,如细胞增殖、分泌、迁移、粘附、蛋白质合成和基因表达等.但低功率He-Ne激光调节细胞行为的分子机制并未阐明,考察低功率He-Ne激光照射后细胞内活性氧自由基的产生水平和游离ca2 浓度是否会发生变化,通过激光扫描共聚焦显微镜,分别利用H:DCFDA和Fluo-3/AM这两种荧光探针,检测到经He-Ne激光照射后,肺腺癌细胞内活性氧自由基的水平上调以及游离Ca2 浓度增加.该研究为低功率He-Ne激光的生物光刺激效应提供了可能的分子机理.     

He-Ne 激光辐照与UV-B 辐射对小麦幼苗细胞器中Na+/K+-ATP 酶活性的影响

分别采用5 mJ.s^-1.mm^-2 He-Ne激光辐照、10.08 kJ.m^-2.d^-1增强UV-B辐射及二者组合对小麦(Triticum aestivum)晋麦8号(Triticum aestivum ‘Jinmai8’)幼苗进行处理。第5 天开始测定各处理小麦幼苗叶片中线粒体、叶绿体及细胞溶质中Na⁺/K⁺-ATP酶活性的变化。结果表明, 随着处理天数的增加, 小麦幼苗叶片线粒体、叶绿体及细胞溶质中Na⁺/K⁺-ATP酶活性均在第6天下降, 第7天升高, 而后又逐渐下降。在处理的第7天, 仅He-Ne激光辐照可使小麦幼苗叶片线粒体、叶绿体及细胞溶质中Na⁺/K⁺-ATP酶活性升高; 增强UV-B辐射使各细胞器中Na⁺/K⁺-ATP酶活性下降; 复合处理后小麦各细胞器中Na⁺/K⁺-ATP酶活性均高于UV-B单独辐射处理。实验结果表明 , 一定剂量的He-Ne激光辐照能够部分修复UV-B辐射对小麦幼苗细胞器中Na^+/K⁺-ATP酶造成的损伤。     

He-Ne激光和增强UV-B辐射对小麦幼苗微管结合蛋白MAP65s的影响

分别采用5 mW/mm2 He-Ne激光辐照、10.08 kJ/m2·d 增强UV-B辐射及二者组合对"临优2018"小麦幼苗进行处理,通过紫外吸收法测定各处理组幼苗中微管结合蛋白MAP65s的含量,并且采用SDS-聚丙烯酰胺凝胶电泳对MAP65s蛋白进行鉴定,进一步分析He-Ne激光对增强UV-B辐射引起的小麦幼苗微管骨架损伤的修复效应.结果显示:经UV-B处理(B)后,小麦幼苗中的MAP65s蛋白含量低于对照组(CK)(P<0.01);单独激光(L)处理,MAP65s蛋白含量高于对照组(CK)(P<0.05);经He-Ne激光和UV-B复合处理(BL)后,MAP65s蛋白含量高于UV-B处理组,低于CK组.该结果表明:一定剂量的He-Ne激光辐照能够促进小麦幼苗微管结合蛋白MAP65s的合成,并且可能在一定程度上修复增强UV-B辐射对小麦幼苗微管骨架系统造成的损伤.     

NO对He-Ne激光和增强UV-B辐射小麦幼苗气孔运动的作用机理研究

为探讨NO对He-Ne激光和增强UV-B辐射小麦（Triticum aestivuml）气孔运动的作用机理,采用低剂量（5 mW.mm-2）He-Ne激光和增强（10.08 kJ.m-2.d-1）UV-B辐射并结合药理学实验和激光共聚焦显微技术,对ML7113小麦的叶片及表皮条进行不同的处理,结果显示：（1）UV-B辐射既可诱导小麦叶片气孔关闭,又能够明显增加气孔保卫细胞和叶片的NO水平,且NO清除剂明显抑制了UV-B辐射诱导的小麦叶片气孔关闭,同时气孔保卫细胞和叶片内的NO含量明显减少。（2）一氧化氮合酶（NOS）抑制剂L-NAME对经UV-B辐射诱导的小麦幼苗气孔开度及保卫细胞和叶片内NO含量的抑制程度明显大于硝酸还原酶（NR）抑制剂NaN3对其的抑制程度,说明一氧化氮合酶（NOS）合成途径是小麦叶片经UV-B辐射后NO的主要产生途径。（3）就气孔开度而言,L〉CK〉BL〉B。就小麦叶片及保卫细胞内NO含量而言,B〉BL〉CK〉L。就硝酸还原酶（NR）和一氧化氮合酶（NOS）的活性而言,B组NR活性最低,NOS活性最高,L组NR活性最高,NOS活性最低。表明经He-Ne激光和增强UV-B辐射诱导的小麦气孔开度的变化确实与保卫细胞及叶片中NO含量的多少有关,气孔开度的减小及增大对应于NO含量的增多或减少,同时进一步证实了小麦叶片经He-Ne激光单独辐照后,NO的主要合成途径也来源于NOS途径。     

Assay of radiation effects in mouse skin as expressed in wound healing

The effect of 150 kVp X irradiation on the healing of full depth surgical wounds in the lower dorsal skin of the mouse was assayed by measuring the wound strength of seven 2-mm-wide segments along each wound. The strength of unirradiated wounds increased with time in two phases: during the first 2 weeks it reached nearly half of the values recorded from unwounded skin, after which the rate of increase slowed for at least 2 weeks before beginning a second increase. By 150 days, the breaking strength of the wound was about 80% of that of unwounded skin. A single dose of 18 Gy prior to wounding reduced the strength of the wounds to about one-third to one-half that of an unirradiated wounds within the 3 months of follow-up. The effect of irradiation on wound strength did not change as the interval between exposure and wounding was increased to 2 months but decreased slightly when this interval was extended to 3 months. When the healing wound was irradiated within 5 days of surgery, the effect on healing was about the same as with preirradiation; if irradiation was delayed for 12 days after wounding the second phase of healing was only postponed and the wound strength ultimately approached the values recorded from unirradiated wounds. The wound strength of skin preirradiated by X rays and assayed 14 days after wounding showed a clear sigmoid dose response with a threshold between 8 and 10 Gy and a plateau at the maximum effect above 20 Gy. The persistence for at least 3 months of the effect of radiation on wound healing suggests that the tissues involved in the healing process are normally proliferating slowly. The accelerated expression of radiation injury through surgical wounding permits the early quantification of the radiation response of tissues that would normally be delayed in their expression of radiation damage.     

Demonstration of elevated type I and type III procollagen mRNA levels in cutaneous wounds treated with helium-neon laser. Proposed mechanism for enhanced wound healing

To assess laser modulation of wound healing, full-thickness cutaneous wounds were produced in the backs of pigs, and subjected to treatment with helium-neon laser. For comparison, some wounds were treated with non-laser energy source (a tungsten light) or left untreated as controls. Type I and type III procollagen mRNA levels were determined in the wounds by molecular hybridization with cDNA probes. The results indicated that type I and type III mRNA levels were markedly increased at days 17 and 28 of the healing in wounds treated with He-Ne laser, when compared to control or tungsten light-treated wounds. The results suggest that helium-neon laser stimulates wound healing by enhancing procollagen gene expression. These observations may have relevance to previous clinical studies suggesting that helium-neon laser stimulates wound healing.     

增强UV-B辐射和He-Ne激光对小麦原生质体微管骨架的影响

以小麦叶片原生质体为材料,采用间接免疫荧光定位法标记其微管系统,并利用激光共聚焦扫描显微系统进行观察。研究了低剂量He-Ne激光(5mW.mm-2)、增强UV-B辐射(10.08kJ.m-2.d-1)及二者的复合处理对小麦幼苗叶肉细胞中微管骨架的影响。结果表明,增强UV-B辐射后,小麦叶片细胞中微管骨架发生解聚,呈短棒状或点状分布,微管束弥散且荧光强度减弱;而增强UV-B辐射后再施以He-Ne激光处理,小麦叶肉细胞微管骨架有部分断裂,但较单独UV-B处理组的损伤程度轻,说明低剂量的He-Ne激光可以部分修复增强UV-B辐射对微管骨架的损伤,且对微管的聚合有促进作用。     

Effect of helium-neon laser on wound healing

To estimate the biostimulatory effects of low intensity laser radiation on healing of skin wounds, two linear skin wounds were produced on either side of dorsal midline in rats and immediately sutured. Wounds on the left side were irradiated daily with helium neon laser at 4 Joules/sq.cm for 5 min., while those on right side were not exposed and served as controls. The mean time required for complete closure in control group was 7 days while irradiated test wounds took only 5 days to heal (P < 0.01). The mean breaking strength, as measured by the ability of the wound to resist rupture against force, was found to be significantly increased in the test group. Early epithelization, increased fibroblastic reaction, leucocytic infiltration and neovascularization were seen in the laser irradiated wounds. The results establish the biostimulatory effects of low intensity laser radiation on healing of skin wounds.     

The effects of low laser irradiation on angiogenesis in injured rat tibiae

The influence of He-Ne laser radiation on the formation of new blood vessels in the bone marrow compartment of a regenerating area of the mid-cortical diaphysis of the tibiae of young adult rats was studied. A small hole was surgically made with a dentistry burr in the tibia and the injured area received a daily laser therapy over 7 or 14 days transcutaneously starting 24 h from surgery. Incident energy density dosages of 31.5 and 94.5 Jcm(-2) were applied during the period of the tibia wound healing investigated. Light microscopic examination of histological sections of the injured area and quantification of the newly-formed blood vessels were undertaken. Low-level energy treatment accelerated the deposition of bone matrix and histological characteristics compatible with an active recovery of the injured tissue. He-Ne laser therapy significantly increased the number of blood vessels after 7 days irradiation at an energy density of 94.5 Jcm(-2), but significantly decreased the number of vessels in the 14-day irradiated tibiae, independent of the dosage. These effects were attributed to laser treatment, since no significant increase in blood vessel number was detected between 8 and 15 non-irradiated control tibiae. Molecular mechanisms involved in low-level laser therapy of angiogenesis in post-traumatic bone regeneration needs further investigation.     

Stress and wound healing.

An experiment was performed to compare the effects of stressors--cold, heat and noise--on primary wound activity (i.e., wound closure in the first 24 h after wound infliction) and on rate of healing in mice. A significant correlation was found between reduced primary wound activity and a faster rate of healing. Conversely, a correlation was found between relatively greater primary wound activity and a slower rate of healing. A possible explanation of this correlation is a compensatory mechanism inherent to the skin healing process. This mechanism is visualized as (1) stress exposure affecting the skin by (a) causing it to become thinner and tauter and (b) causing it to have less elastic recoil; therefore, (2) when a square wound is produced in stressed skin, (a) the wound does not recoil readily or gapes soon after cutting and (b) a longer wound perimeter results. Because there is evidence that rate of healing is governed by cells on the wound perimeter, the greater the perimeter, the greater the number of cells that will undergo rapid mitosis and the faster will be the rate of healing. Therefore, stressed skin will heal at a faster rate, compensating for the loss of elasticity and cellular depletion caused by stress. This study is of interest to anthropology because it deals with dynamic adaptation, trying to grasp the meaning of the elusive endocrine interface between environmental stimulation and a measurable physical entity like healing. This work may have revealed a functional complex that is common to the healing of all mammalian skin, whereby retarding effects of stress on the healing process are obviated.     

He-Ne激光对增强UV-B辐射小麦幼苗多胺氧化酶和过氧化物酶活性的研究

采用He-Ne激光辐照对增强UV-B辐射后小麦幼苗的损伤修复作用进行了研究。小麦种子在盛有湿滤纸的培养皿内25℃下进行萌发。萌发后小麦幼苗在经10.08 kJ·m^-2·d^-1的增强UV-B辐射,然后再用5 mW·mm^-2的He-Ne激光进行辐照。通过小麦幼苗叶片游离脯氨酸含量、多胺氧化酶和过氧化物酶的活性变化,测定了He-Ne激光对小麦UV-B损伤的修复情况。结果表明,游离脯氨酸、多胺氧化酶、过氧化物酶的变化同小麦幼苗损伤的修复的能力相关联。He-Ne激光辐照可使由增强UV-B辐射后诱导叶片升高的游离脯氨酸含量降低。增强UV-B辐射对多胺氧化酶（PAO）活性和过氧化物酶（POD）活性呈促进的作用。辐射6 d后PAO和POD总的活性呈正相关性,PAO和POD活性都呈现B组最高,L组最低,且差异显著。显示He-Ne激光对两种酶由于增强UV-B辐照造成的伤害有一定的修复。