فصلنامه لیزر در پزشکی
سال ششم شماره 4 (پیاپی 33، زمستان 1388)

This RCT was designed to evaluate the analgesic effect of single-session of NACLT on major recurrent aphthous stomatitis (maRAS).

Five patients, each with two discrete major aphthous ulcers, were included. One of the ulcers was randomly allocated to be treated with CO2 laser (1 W of power in de-focused continuous mode) and the other one served as a placebo. Before laser irradiation, a layer of transparent, non-anesthetic gel with high water content was placed on both the laser lesions and the placebo ones. The patients graded their pain on a visual analog scale up to 4 days post-operatively.

The reduction of pain scores was significantly greater in the laser group than in the placebo group in all follow-up periods (p <0.001). The procedure was not painful, and anesthesia was not required. There were no visible side effects after NACLT and during follow-up periods.

Our results suggested that irradiation of CO2 laser through a layer of transparent gel with high water content (NACLT)could reduce pain in maRAS immediately and significantly, without any visible side effects.

Previous neuroimaging studies using task stimulation data have found hyperactivation in the cerebellum and motor cortex and hypoactivation in the basal ganglia in patients with Parkinson's disease (PD). However, resting state analysis and functional connectivity between regions are rarely investigated in PD. In the present study, three important problems have been considered: First, we calculated the low frequency fluctuations in resting state Parkinson disease and compared to the controls. Second, we analyzed the regional homogeneity for measuring the local similarity between PD and controls and third the functional connectivity and correlation between regions in PD were investigated. The results from group analysis on low frequency fluctuation maps confirmed the previous finding on task stimulation data and showed hyperactivation in the cerebellum and motor cortex and hypoactivation in the basal ganglia in PD. Moreover, regional homogeneity analysis did not show any significant difference between two groups. In addition, the results of statistical tests on functional connectivity showed the negative significant correlation in low frequency fluctuations between some regions in motor area and basal ganglia. This negative connectivity is only in PD and there are positive significant correlations within motor area and basal ganglia regions in control groups.

Trichophyton rubrum is one of the major causes of dermatophytosis both in the world and in Iran. Trichophyton rubrum invades keratinized tissues (hair, skin and nails) of humans and animals. Dermatophytosis is recurrent and drug-resistant. Furthe more, it often needs expensive treatmens. In a search about new treatment modalities alongside conventional drug therapies in order to achieve a better control for dermatophytosis, we studied the effect of Low Level Laser Therapy(LLLT) using diode laser (685 and 830 nm) on Trichophyton rubrum in an in-vitro setting.

In this in-vitro study,at first we identified T.rubrum using standard methods. Then equal amounts of T.rubrum were cultured on Sabouraud Dextrose Agar with Chloramphenicol and Cyclohexamide (Scc) plates. Afterwards,the plates were irradiated in 9 group using Diode laser(BTL 2000) 685 nm (25 mW; 3,5,10,20 J/Cm2)and 830 nm (200mW;3,5,10,30,50 J/Cm2). In each group 12 plates were irradiated. Also 12 plates served as control group. Then plates were examined for inhibition of growth, macroscopic and microscopic morphology, minimum inhibitory concentrations (MIC) and genomic changes following exposure.

The results of this study indicated that the fungal growth were observed in all groups, but LLLT is effective on quality of growth of Trichophyton rubrum in a dose dependent manner. All these changes were obvious in laser groups irradiated by 685 nm and 830 nm at a fluencies ≥ 10 J/cm2. The most changes were observed at the fluence 20 J/CM2 (685nm) and 30 J/CM2 (830 nm). (p<0/001).

In this study, LLLT didn’t inhibit the fungal growth, but changes in the quality of growth of Trichophyton rubrum imply that LLLT h effects on the T.rubrum independently, and these changes probably occur on the protein synthesis level and gene expressions.

Many biomaterials have convenient bulk properties and they need some special surface treatments to enhance the requirements of biomedical usage. The laser has some unique properties for surface treatment. Some of common advantages of laser treatments in comparison to alternatives includes cleanliness, controlled thermal and shape changes, less after-machining, remote non contact processing. At present, the lasers are being used in some surface treatments like laser patterning, pulsed laser deposition, matrix-assisted pulsed laser evaporation (MAPLE) and MAPLE direct write (MDW) and laser grafting, which will be discussed.

Once, laser and IPL Procedures were limited to physicians and operating rooms, but during the last decade, the laser and light-based devices have become much smaller, cheaper and easier to use. Such home-use and light sources should be not only really clinically effective, but also being safe. In addition they should be cost-effective in mass production and easy to use without special training. Since laser hair reduction seems to require less expertise than other laser procedures, companies have developed low- energy laser and pulsed-light devices for hair removal. Although the results of these home-use devices for hair reduction are still inferior to office-based ones, it seems that market for these devices will rapidly expand in the next years. In these articles we will focus on currently available IPL and laser sources for hair reduction and then we will discuss about other home-use laser and light-based devices in dermatology.