ADVANCES IN SKIN, WOUND AND TISSUE REPAIR
Year:2006 | Volume:4 | Issue:3 (25)|Papers Count:8

Background and Objectives: Considering wide applications of Ti alloys in medicine as medical implants, attentions are focused on surface properties of these alloys and their behaviour in body fluid.Material and Methods: In present research, the interaction of pulsed Nd:YAG laser with Ti6Al4V and its effects on surface properties were evaluated. Modelling of osteoblast cells adhesion to Ti6Al4V and its dependency on stress, temperature, time and surface microstructure was also studied.Results and Conclusions: The results indicate that irradiation of Ti6Al4V with Nd:YAG laser under optimum conditions have a number of considerable advantages including the increase of corrosion resistance, surface hardness and reduction of vanadium.

Background and Objectives: After injury to the peripheral nerves, one of the most common side effects is slow regeneration, leading to the atrophy of muscles innervated with injured nerves. Low power laser is one of the therapies, because of biostimulation effects of this type of laser. This study was undertaken to evaluate the effect of low power laser in regenerating of injured sciatic nerve in rat.Material and Methods: Sciatic nerve of 19 rats was crushed and irradiated with He-Ne laser (632.8 nm, 20 mW, and 300 s) for 24 days. Irradiation in 14 rats was locally in injury site and to evaluate the systemic effects was in plantar area in 5 rats. 14 rats were irradiated with sham laser in similar situation as control group. Angle-board test was considered to evaluate the function of sciatic nerve.Results: After 24 days, results of angle-board test showed that there was no significant difference between nerve function before injury and after laser irradiation in case groups; but in control group, the function of injured nerves according to angle-board test results were significantly lower in comparison with before injury (p-value=0.000).Conclusions: This study showed that low power laser has a positive effect on regeneration of sciatic nerve through both local and systemic irradiation.

Background and Objectives: Sperm motility and progressive velocity play a key role in the process of the fertilization of oocyte in vitro and in vivo. The biostimulating effect of laser has already been demonstrated in activating the redox reaction in the respiratory chain by exciting mitochondrial cytochromes in cell and influences the amount of calcium in sperm cells. The present study evaluated possible stimulatory effects of low level laser irradiation on normal human sperm motility velocity and mortality.Materials and Methods: A GaAlAs laser (Model No: AMM50) at different energy density 2, 4, and 8 J/cm2 (each 8 hour), was used to iiradiate sperm cells ejaculated from 12 cases. Sperm motility, velocity and mortality measured 24 hour after irradiation.Results: Motility and velocity of sperms which were exposed to 2 and 4 J/cm2 significantly enhanced compared to sham irradiated control group. Likewise number of dead sperms decreased in groups exposed to 2 and 4 J/cm2 laser irradiation. There was no significant differences between 8 J/cm2 irradiated and control groups.Conclusions: GaAlAs (810nm) irradiated at dose of 2 and 4 J/cm2 enhanced the motility and velocity of sperms and decreased the mortality of sperms, and it might be used to promote the the motility and survival of sperm in order to increase the fertility rate of infertile patient with motility dysfunction.

Background and Objectives: Bone marrow suppression is a common case that occurrs in many conditions such as chemotherapy in treatment of different cancers. Considering the effect of low level lasers on cell proliferation, we studied its effect on blood cells in rats with suppressed and natural bone marrow.Materials and Methods: The study was performed on 120 male rats. Sixty were injected a dose of Cyclophosphamide (75mg/kg IP) for bone marrow suppression. A GaAlAs laser device (50mw, 30j/cm2) was used for laser irradiation for five days in two groups when the other two groups served as control. At last blood samples were collected and bone marrow biopsies were performed.Results: There was no statistical significance in blood cell count between laser and control groups. But MCH and MCHC, both, were increased in laser irradiated group with suppressed bone marrow.Conclusions: This study failed to show any significant differences in blood cell count in laser irradiated groups and controls.

Background and Objectives: To determine the true efficacy of the 308-nm excimer laser for the treatment of vitiligo, while taking into account confounding factors such as anatomic site of treatment, age, sex, skin type, MED, and duration of evolution of the vitiligo. Material and Methods: Thirty-five patients with vitiligo were included. Each lesion was treated twice a week by the 308-nm excimer laser for a maximum of 24 sessions. Efficacy was blindly evaluated by two independent physicians. Results: Repigmentation was noted in 46 plaques/52 (88.5%). Repigmentation rate (75%) was obtained in 14 (26.9%). In ‘‘UV sensitive’’ areas (face, neck, trunk), 8/14 lesions (57.1%) had a repigmentation rate, 75% versus 6/38 (15.8%) in "UV resistant" areas (bony prominences and extremities) (P¼0.031). No relationship could be established between response to the treatment and the following variables: age, sex, skin type, MED, and duration of evolution of the vitiligo.Conclusions: An aesthetically reasonable result is achieved essentially in ‘‘UV sensitive’’ areas, thus appearing to be the appropriate places of choice for this treatment.

Background and Objectives: This investigation describes the effect of low level laser therapy (LLLT) on treatment of post-mastectomy lymphedema.Materials & Methods: Eleven women with unilateral arm lymphedema were included in this study. Patients received laser or placebo irradiation (GaAs/Mustng 890 nm, fluence: 1 J/cm2) over the arm and axillary area as laser and sham groups, respectively.Results: Four patients in each group (laser or sham) completed the treatments. Changes in limb circumference, pain score, motility and heaviness of the affected limb and desire to continue the treatment in five sessions of follow up were measured and compared to pre-treatment status. Pain reduction in laser group was more than sham group except for the weeks 3 and 9.Conclusions: Our study showed that LLLT with the wavelength of 890nm may have effects on reduction of pain and circumference of lymph-edematous limb after mastectomy.