Lasers in Medicine
Year:2008 | Volume:5 | Issue:2 (28)|Papers Count:7

Background/ Objective: In this study, we investigated the effect of Low- Intensity Ultrasound on Osteogenic differentiation of rat bone-marrow derived mesenchymal stem cells (rMSCs).Material and Methods: Ultrasound instrument with 3MHz frequency was calibrated by radiation force method. rMSCs isolated from rat's Tibia and Femur central canal were cultured in medium complemented with FBS. We promoted rMSCs for three successive passages in order to purify them. The ultrasound (US) group received US stimulation at a frequency of 3 MHz and intensity of 355 mW.cm-2, continuous mode, for 5 min every day up to 2 weeks, while the control group had no US stimulation. Alkaline phosphatase activity assay and semi-quantitative RT-PCR for alkaline phosphatase, Osteocalcin and Osteopontin expression were made at 1st, 2nd, 3rd, 5th, 7th, 9th, 11th and 14th days post-stimulation, respectively.Results: Our results showed that alkaline phosphatase activity in US group was significantly more than that of control (88.6±12% versus 30.14±23%) (p £0.005). According to semi quantitative RT-PCR data, group differentiation gene expression was significantly different in two groups (p£0.005).Conclusion: This study suggests that ultrasound may have some stimulatory effects on the Osteogenesis of rMSCs in vitro.

Background/ Objectives: Acne vulgaris affects most people at some time in their life and can have devastating effects on a person's quality of life and may leave permanent scars. Some invetations have shown favorable effects within the phototherapy for the treatment of acne vulgaris.In this study, we have evaluated the use of two wave length of low level laser therapy (LLLT) in the treatment of acne vulgaris.Material and Methods: Twenty eight patients (18 female and 10 male) with acne were enrolled. The righe and left sides of patients’ face were irradiated with red (630 nm) and infrared (890 nm) LLLT, respectively. Active lesion counts for clinical assessments were conducted before starting treatment, at 2, 4, 6 and 8 weeks.Results: Active lesions were reduced more on red LLLT-treated than on infrared LLLT-treated sides (p<0.05).Conclusion: Red LLLT is superior to infra-red LLLT for the treatment of inflammatory acne.

Background/ Objective: A major problem in the treatment of cancer is the lack of an appropriate method for the early diagnosis of the disease. The breast cancer is a widespread disease within the population of women, and its early diagnosis can greatly prevent the mortality rate. At present, there is no appropriate tumor marker for early diagnosis of the disease. The chemical reaction within an organ may be reflected in the form of proteomic patterns in the serum, sputum, or urine. The surface-enhanced laser desorption/ ionization time-of-flight mass spectrometry is a valuable tool for extracting proteomic patterns from biological samples. A major challenge in analysis of such patterns is the presentation of a data mining algorithm to select appropriate biomarkers to distinguish between healthy and cancer cases.Materials and Methods: In this research, the data corresponding to proteomic patterns of serum from patients with breast cancer was analyzed. Using a mathematical model and discrete wavelet transform, baseline and electrical noises were eliminated in the preprocessing stage with subsequent normalization of the mass spectra.Our hybrid data mining algorithm is based on a statistical test, class separability measure, and peak scoring. With our method, the best protein subset was selected from 13488 data points while maintaining the valuable information and discriminative power. The selected feature subset was then used for the detection of biomarkers.Results: Using the method of k-fold cross validation, the samples under study were divided randomly into two sets namely the learning and test sets. We identified the least threshold value of 1.96. The data mining algorithm was applied to the remaining data points from thresholding step. Then, the best feature subset was selected which included high power discriminatory biomarkers. Using linear discriminant analysis (LDA), 19 proteins were selected as biomarkers that were able to discriminate healthy and cancer samples with accuracy of 100%, specificity of 100%, and sensitivity of 100%.Conclusion: With the generation of complete information from biological specimens, we can use these to diagnose the diseases showing poor markers such as cancer. Disease diagnosis is an example of pattern recognition. In this paper, we have introduced a data mining algorithm to select the best feature subset from protein patterns. Our proposed method has shown to have a good discriminative power with reduction of the number of biomarkers. Our results suggest that the appropriate selection of significant proteins have an important effect for biomarker identification in the correct diagnosis of the disease.

Background/ Objective:Melanoma is one of the common types of skin cancer the diagnosis of which is difficult for most dermatologists. To observe and diagnose the type of skin cancer, the non-invasive dermatoscopy is generally used. As this method depends on visual observation and evaluation, the diagnosing of melanoma, particularly in its early stage, is rather complicated and difficult. The diagnosis can be made easier if the boundary between the lesion and the surrounding non-affected area can be determined accurately. This article presents a method which can determine the boundary accurately and therefore facilitate diagnosis of the melanoma.Materials & Methods: We have shown, using simulation work, the importance of using polarized filter for determining the boundary between the lesion and surrounding area. The simulated polarized filter, with an appropriate selection of polarizer angle, is applied to the dermatoscopic image. This technique provides a new approach to preprocessing of images of cancerous lesions by increasing the contrast between the lesion and shadows. The boundary detection algorithm can then be used on the best preprocessed image to define the boundary. The resulting image can then be used by the dermatologist to diagnose possible melanoma.Results: Before using the boundary detection algorithm, applying the simulated polarized filter to the image causes reduction of noise considerably. One of the sources of noise in the image is the presence of hair. The use of polarized filter will greatly decrease interfering noise due to the presence of hair. Another source of noise is the inclusion of surrounding area within the boundary while leaving out part of the lesion under study. By appropriate selection of polarizer angle one can define the boundary more accurately.Conclusion: The simulated polarized filter provides an efficient preprocessing tool for determining the boundary between the lesions and surrounding tissue very accurately. This is very important when melanoma is being examined by the dermatologist. In this article, we have shown that using the above technique can assist the dermatologist to diagnose melanoma more accurately.

Background/ Objective: During past 30 years, low-level lasers have been widely used in medical fields. Lowlevel laser irradiation (LLLI) in red and near infrared region, locally or intravenously may result in vasodilatation, increased tissue perfusion and neovascularization. Here, we describe apatient with acute atheroembolism who treated with LLLI.Case- Report: A 64-year old Iranian man was referred to our clinic with acute atheroembolism of distal phalanx index finger. There was no predisposing cardiovascular factor except for a mild hypercholesterolemia, and physical examination was generally normal. We used low-level laser therapy with infrared light, 980 nm/ 100 mW and red light, 650 nm/ 30 mW, associated with 3 sessions of intravenous red light laser, 630nm, 2 mW. After 12 sessions (about 30 days) ischemia disappeared and the finger was quite normal. On 12 months of follow-up, the patient was uneventful.Conclusion: Delivery energy to the ischemia-induced necrotic area may have an important beneficial effect on patients with acute thromboembolism of fingers, preventing them from amputation or other invasive surgical interventions. However, additional studies and more clinical evidence are needed to demonstrate the various aspects of this application of lasers in medical practice.