LASER FLORENCE 2009: A Gallery Through the Laser Medicine World
1226(2010); http://dx.doi.org/10.1063/1.3453785View Description Hide Description
Light therapy commonly referred to as low level laser therapy can alter cellular functions and clinical conditions. Some of the commonly reported in vitro and in vivo effects of light therapy include cellular proliferation, alterations in the inflammatory response to injury, and increases in mitochondrial respiration and adenosine triphosphate synthesis. Based on the known effects of light on cells and tissues in general and on reports in the last 5 years on the interaction of light with stem cells, evidence is mounting indicating that light therapy could greatly benefit stem cell regenerative medicine. Experiments on a variety of harvested adult stem cells demonstrate that light therapy enhances differentiation and proliferation of the cells and alters the expression of growth factors in a number of different types of adult stem cells and progenitors in vitro. It also has the potential to attenuate cytotoxic effects of drugs used to purge harvested autologous stem cells and to increase survival of transplanted cells.
Intracavity Laser Refractometry In Reflection: Development And Implementation In Biomedical Investigations1226(2010); http://dx.doi.org/10.1063/1.3453771View Description Hide Description
The Intracavity Laser Refractometry in Reflection (ILRR) method is developed for precise investigation of the processes on an interface of different media in real time. This method is very attractive for the study of biological liquids. It is based on the control of two‐mode phase‐anisotropic laser spectrum. In the aggregate the values of the sensitivity, time of measuring, potential parameters of investigated media of ILRR method correspond to the best results in optical refractometry. The absolute value of refractive index correlates with the course of different diseases. It can serve the objective parameter for an estimation of a level of illness processes in organism and drug efficiency. In result of the investigation of the photoresponse of the blood to low‐level laser irradiation both the slow thermal effect and fast biophysical effect were discovered. The refractive index behaviour in real time allows the photoacceptors and maximum therapeutic doses on organism, cellular, and molecular levels to be determined.
1226(2010); http://dx.doi.org/10.1063/1.3453782View Description Hide Description
Background and Objectives: Cellulite is a biological caused modification of the female connective tissue. In extracorporeal shockwave therapy (ESWT) pulses are penetrating into the tissue without causing a thermal effect or micro lesions, but leading to a stimulation of tissue metabolism and blood circulation, inducing a natural repair process with cell activation and stem cells proliferation. Recently ESWT treatment showed evidence of remodelling collagen within the dermis and of stimulating microcirculation in fatty tissue.
Study Design and Methods: The study was designed to assess acoustic wave treatment for cellulite by comparison treated vs. untreated side (upper‐leg and buttock). Each individual served as its own control. 11 females with a BMI less then 30 and an age over 18 years were included. 6 treatments were given weekly with radial acoustic waves. Documentation was done before and 1, 4, 12 weeks after last treatment by standardized photo documentation, relaxed and with muscle contraction, measurement of body weight and circumference of the thigh, pinch test, and evaluation of hormonal status and lifestyle. The efficacy of AWT/EPAT was evaluated before and 1, 4, 12 weeks after last treatment. Patients rated the improvement of cellulite, overall satisfaction and acceptance. The therapist assessed improvement of cellulite, side effects and photo documentation treated vs. untreated side, before vs. after treatment. The blinded investigator evaluated the results using photo documentation right vs. left leg, before vs. after treatment in a frontal, lateral and dorsal view, relaxed and with muscle contraction.
Results: The improvement of cellulite at the treated side was rated by patients with 27,3% at week 4 and 12, by the therapist with 34,1% at week 4 and 31,2% at week 12 after the last treatment The blinded investigator could verify an improvement of cellulite in an increasing number of patients with increasing time interval after treatment. No side effects were seen.
Conclusion: Radial acoustic waves are effective and safe to treat cellulite. The effect of treatment begins delayed and is first seen after 5 treatments. The improvement of cellulite increases continual up to 3 months. Patients’ satisfaction and acceptance is high
1226(2010); http://dx.doi.org/10.1063/1.3453783View Description Hide Description
The aim of the present study is to demonstrate the possibility to assess the depth of suspected skin lesion in‐vivo, using multispectral digital dermatoscopy (MDD); being malignant lesion depth an important factor related to survival rate. The system realised in this work is based on a special multi‐wavelength LED illuminator (700 nm, 940 nm and 950 nm) and an high quality CCD camera which allows to acquire a detailed image of the suspected skin lesion. A statistically significant correlation between contrast of the area of the lesion at single wavelength and the depth of the lesions in vivo (as determined by histopathology survey) has been found using 39 samples. Interesting results, have been especially obtained using illuminating wavelength at 940 nm and 950 nm. Using a linear fitting of our data the maximum depth of melanoma has been overestimation of 0.43 ± 0.26 mm. The present study shows a possible use of our MDD system as in the assessment of maximum depth of suspected skin lesions.
1226(2010); http://dx.doi.org/10.1063/1.3453784View Description Hide Description
Dermatography is the application of medical tattooing techniques. In the past, similar techniques were tried but none led to reproducible results. This study deals with the negative effects of ‐(Er:YAG) laser treatment used for cosmetic facial resurfacing. These effects can be subdivided into two categories: the sequelae of poor (post‐)operative techniques, and the inadequacy of postoperative treatment modalities. Dermatography has been applied to treat the adverse effects successfully.
1226(2010); http://dx.doi.org/10.1063/1.3453786View Description Hide Description
The use of 5‐aminolevulinic acid (ALA) administration has led to many applications of photodynamic therapy (PDT) in cancer. However, the hydrophilic nature of ALA limits its ability to penetrate the cells and tissues, and therefore the need for ALA derivatives became an urgent research target. In this study we investigated the activity of novel multifunctional acyloxyalkyl ester prodrugs of ALA that upon metabolic hydrolysis release active components such as, formaldehyde, and the histone deacetylase inhibitory moiety, butyric acid. Evaluation of these prodrugs under photo‐irradiation conditions showed that butyryloxyethyl 5‐amino‐4‐oxopentanoate (ALA‐BAC) generated the most efficient photodynamic destruction compared to ALA. ALA‐BAC stimulated a rapid biosynthesis of protoporphyrin IX (PpIX) in human glioblastoma U‐251 cells which resulted in generation of intracellular ROS, reduction of mitochondrial activity, leading to apoptotic and necrotic death of the cells. The apoptotic cell death induced by ALA / ALA‐BAC followed by PDT equally activate intrinsic and extrinsic apoptotic signals and both pathways may occur simultaneously. The main advantage of ALA‐BAC over ALA stems from its ability to induce photo‐damage at a significantly lower dose than ALA.
1226(2010); http://dx.doi.org/10.1063/1.3453787View Description Hide Description
Accelerated synthesis of protoporphyrinIX (PpIX) following ALA pre‐treatment followed by light irradiation is the principle of ALA‐PDT. Several limiting enzymes were suggested to control PpIX accumulation and PDT efficacy, among them porphobilinogen deaminase (PBGD) and ferrochelatase. Here we reveal the centrality of ALA dehydratase (ALAD) activity in predicting ALA‐PDT efficacy. Silencing of ALAD expression and activity was carried out in leukemic cells using shRNA plasmid transfection or intoxication. ALAD activity, porphyrin synthesis and mitochondrial activity were determined versus PDT efficacy.
In K562 ALAD‐silenced cells, ALAD activity and expression were reduced and as a result, PpIX synthesis was almost abolished. Following ALA treatment and irradiation, ALAD‐silenced cells depicted normal mitochondrial activity, in contrast to control and non‐silencing transfected cells where accumulated PpIX and irradiation caused ROS formation and mitochondrial damage. Morphological analysis by scanning electron microscopy (SEM) of ALA‐PDT treated cells showed no morphological changes in ALAD‐silenced cells, while controls exhibited cell deformations and lysis. Annexin V‐FITC/PI staining as well as LDH‐L leakage testing showed that membrane integrity was undamaged following ALA‐PDT in ALAD silenced cells. treatment in MEL cells impaired ALAD activity and reduced PpIX synthesis but to a lesser extent.
In conclusion, we show that a dramatic reduction in PpIX accumulation following down regulation of ALAD expression prevents an efficient PDT. Thus, ALAD has a major role in regulating PpIX synthesis and ALA‐PDT therapeutic outcome. Monitoring ALAD expression or activity in various tumors may be useful as prognostic tool to predict PDT efficacy.
Metal‐free Phtalocyanine and 5‐Aminolevulenic Acid in Photodynamic Treatment of Human Vascular Cells1226(2010); http://dx.doi.org/10.1063/1.3453788View Description Hide Description
Originally developed as a tumor therapy, now photodynamic therapy (PDT) may become a useful tool for treatment of cardiovascular diseases. Different cell types are involved in this vascular pathology, and these cells possess different susceptibility to PDT. In this study we screened the effects of two new photosensitizers (PtS and ALA) on human vascular cells. Human macrophages (Mph), aorta endothelial (HAEC) and smooth muscle (SMC) cells were obtained and cultured as described elsewhere. PtS was added to culture medium 24 h before PDT. ALA was added in concentration in serum‐free culture medium. Then cells were washed carefully and illuminated with 692‐nm (PtS) or 633‐nm (ALA) light. Cellular viability was measured with MTT‐test. Except the case of use 5–10 mM ALA, either photosensitizer accumulation alone or laser illumination alone did not affect cells. Illumination of PtS or ALA–loaded cells impaired cellular viability in dose‐dependent manner. for different vascular cells with PtS were as follows: HAEC ‐1 SMC Mph HAEC and some Mph were unsusceptible to ALA‐PDT. SMC LD90 with ALA was Effects of ALA‐PDT depended on protoporphyrin IX (PpIX) formation in cells. HAEC didn’t accumulate PpIX and were non‐sensitive to ALA‐PDT. PpIX formation in Mph changed individually according to donor. Illumination of ALA‐loaded Mph with low PpIX formation did not affect cells. However for Mph with high PpIX formation comprised All cell types were more susceptible to PtS‐PDT compared to ALA‐PDT. Among tested photosensitizers PtS was the most effective one. HAEC were the most susceptible to PtS‐PDT.
Percutaneous Laser Disc Decompression (PLDD): Experience and Results From Multiple Centers and 19,880 Procedures1226(2010); http://dx.doi.org/10.1063/1.3453789View Description Hide Description
In mid‐February 1986, Peter Ascher and Daniel Choy performed the first Percutaneous Laser Disc Decompression (PLDD) at the Neurosurgical Department, University of Graz, Graz, Austria. It was planned to deliver 1000 joules with a Nd:YAG laser to a herniated L4‐5 disc causing sciatica. At 600 joules the procedure was terminated because the pain was gone.
Since then, PLDD has spread all over the world, with procedures being performed in the entire spine except for T1‐T4 because these discs do not permit percutaneous access with a needle. The success rate has ranged from 70 to 89%, and the complication rate, chiefly discitis, from 0.3 to 1.0%. When successful, return to normal work averages one week. Long term follow‐up to 23 years yields a recurrence rate of 4–5%.
1226(2010); http://dx.doi.org/10.1063/1.3453790View Description Hide Description
A new type of the surgical instruments is being developed—sapphire scalpels with a possibility of the fluorescent diagnostics of the state of incised tissue near the cutting edge directly in the process of the surgical operation. The principle of the new system is based on the use of two isolated capillary channels in the volume of the sapphire scalpel for introducing of quartz waveguides. One of the waveguides is used for delivering the laser radiation directly to the blade and excitation of photoluminescence near the cutting edge. The second one is used for catching and transfer of photoluminescence to spectrometer. The scalpel employs rapid real‐time feedback analysis for on‐line diagnostics of tissues during surgery to remove a tumor.
1226(2010); http://dx.doi.org/10.1063/1.3453791View Description Hide Description
Investigation of combined application of different type of cells, delivery methods with laser irradiation of retina on an animal model in vivo(rabbit eye) was the purpose of the study. An argon at 514nm and a dye laser at 577nm with were used to provide a controlled damage on the rabbit retina. Two type of human progenitor stem cells(hPSC) were tested: Mesenchymal and Neural. Four cell delivery methods were compared: Retrobulbar, Introvitreous, Subconjuctival and Suprachoroidal injections. Electroretinography(ERG) was used as a diagnostics of retina functionality. Selective immunohystochemical analysis was performed to assess cells migration and viability. Controlled laser damage on retina provides strong attracting signal for stem cells. Application of laser light enhances results of stem cells injection in posterior eye and may have benefits for treatment of different types of retinopathy and macular degeneration.
Detection of Cervical Cancer Analyzing Blood Samples with Raman Spectroscopy and Multivariate Analysis1226(2010); http://dx.doi.org/10.1063/1.3453792View Description Hide Description
The use of Raman spectroscopy to analyze blood biochemistry and hence distinguish between normal and abnormal blood was investigated. The blood samples were obtained from 20 patients who were clinically diagnosed with cervical cancer and 10 healthy volunteer. The imprint was put under the Olympus microscope and several points were chosen for Raman measurement. All spectra were collected at a Jobin‐Yvon LabRAM HR800 Raman Spectrometer with NIR 830 nm laser. It is shown that the serum samples from patients with cervical cancer and from the control group can be discriminated when the multivariate statistical methods of Principal Component Analysis (PCA) and Linear Discriminated Analysis (LDA) is applied to their Raman spectra. The ratios of some band intensities were analyzed and some band ratios were significant and corresponded to proteins, phospholipids, and polysaccharides. The preliminary results suggest that Raman spectroscopy could be a new technique for the detection using just blood samples.
1226(2010); http://dx.doi.org/10.1063/1.3453793View Description Hide Description
The biomarker discovery for accurate detection and diagnosis of cervical carcinoma and its malignant precursors represents one of the current challenges in clinical medicine. Laser induced autofluorescence spectra in cervical smear content were fitted to predict the cervical epithelium diagnosis as a lab off ”optical biopsy“ method. Liquid PAP supernatant sediment dried on Quartz plate spectroscopy was performed by 355 nm Nd YAG microlaser STA‐1 (Standa, Ltd). For comparison a liquid supernatant spectroscopy was formed by laboratory ”Perkin Elmer LS 50B spetrometer at 290, 300, 310 nm excitations. Analysis of spectrum was performed by approximation using the multi‐peaks program with Lorentz functions for the liquid samples and with Gaussian functions for the dry samples. Ratio of spectral components area to the area under whole experimental curve (SPP) was calculated. The spectral components were compared by averages of SPP using Mann‐Whitney U‐test in histology groups. Results. Differentiation of Normal and HSIL/CIN2+ cases in whole supernatant could be performed by stationary laboratory lamp spectroscopy at excitation 290 nm and emission >379 nm with accuracy AUC 0,69, Sens 0,72, Spec 0,65. Differentiation Normal versus HSIL/CIN2+ groups in dried enriched supernatant could be performed by 355 nm microlaser excitation at emission 405–424 nm with accuracy (AUC 0,96, Sens 0,91, Spec 1.00). Diagnostic algorithm could be created for all histology groups differentiation under 355 nm excitation. Microlaser induced ”optical biopsy “looks promising method for cervical screening at the point of care.
Carbon dioxide laser turbinectomy versus submucosal diathermy of hypertrophied turbinates. Histopathological prospective study1226(2010); http://dx.doi.org/10.1063/1.3453769View Description Hide Description
Aim: To assess suspected turbinate mucosal distractive changes of CO2 laser partial turbinectomy as compared to submucosal diathermy technique of hypertrophied inferior turbinates and thus risk of appearance of mucosal atrophic changes.
Introduction: CO2 laser turbinotomy or turbinectomy has become an established well documented line of treatment of hypertrophied inferior turbinates not responding to medical treatment. Although there have been several reports discussing the clinical aspects of laser turbinectomy, but exact pathological changes that take place following laser application to the turbinate have not been described completely and clearly. For this reason this study was conducted to confirm these possible histopathological changes and compared with those following submucosal diathermy technique.
Patients and methods: Twenty patients with chronic hypertrophied inferior turbinates and presenting mainly with nasal obstruction, ten out of them were subjected to CO2 laser turbinectomy while other half underwent to submucosal diathermy technique. Tiny biopsies were taken immediately after surgery (within one week after surgery ), as well as 4–6 weeks later and processed for further histopathological evaluation.
Results: By 100%, the all patients of two groups showed areas of epithelial loss were observed immediately after both techniques. 4–6 weeks after laser application 60% of patients showed normal epithelial areas as compared to second group where 20% of patients who showed normal epithelial picture.
Conclusion: CO2 laser turbinectomy can be considered as more preservative technique for nasal mucosa as well as the function of the nose as compared to submucosal diathermy technique.
1226(2010); http://dx.doi.org/10.1063/1.3453770View Description Hide Description
Background: Methycillin resistant staphylococcus aureus (MRSA) bacteria continue to defy most available antibiotics. As a result infections with MRSA remain a growing public health concern. As a paradigm shift and a significant departure from the on‐going trend to develop stronger drug‐based therapies, we studied the effect of 405 nm and 470 nm wavelengths of blue light on two strains of MRSA—US‐300 strain of CA‐MRSA and the IS853 strain of HA‐MRSA—in vitro. Methods: We cultured and plated each strain, following which bacteria colonies were irradiated with 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 25, 30, 35, 40, 45, 50, 55, or energy densities—just once. Specimens were incubated at 35° C for 24 h. Then, digital images obtained were quantified to obtain colony counts and the aggregate area occupied by bacteria colonies. Results: Each wavelength produced a statistically significant dose‐dependent reduction in both the number and the aggregate area of colonies formed by each bacteria strain (P<0.001). Maximum eradication of the US‐300 (92.1%) and the IS‐853 colonies (93.5%) was achieved within 10 minutes of irradiation with each wavelength. The longer the irradiation the more bacteria were eradicated. However, the effect was non‐linear as increases of energy densities between 1.0 and resulted in more bacteria death than similar increases between and Conclusion: At low doses, blue light photo‐destroys HA‐MRSA and CA‐MRSA in vitro; raising the prospect that phototherapy may be an effective clinical tool in the on‐going effort to stem MRSA infections.
Post‐evaluation of the neurophaties treatment post‐trauma with therapeutic laser. Model in sciatic nerve of frog1226(2010); http://dx.doi.org/10.1063/1.3453772View Description Hide Description
The purpose of this study was to evaluate the compound nerve action potential amplitude and latency measured to determine the degree of myelination and the number of fibers stimulated in a model of stimulated frog sciatic nerve laser at 810 nm as perioperative treatment after injury. It used 30 bullfrogs (Rana catesbeiana) to obtain 60 sciatic nerves forming four groups, groups 1 and 2 worked with nerves in vitro, were dissected in humid chambers for placing isolated organ, was recorded on compound nerve action potential, the second group laser was applied at 24, 48, 72, 96 and 120 hours and at the same time were placed in 10% formalin. Groups 3 and 4 are worked in vivo localizing the nerve and causing damage through compression, occurred over the compound nerve action potential to assess the degree of myelination and the number of fibers stimulated, the group 4 was applied to 810 nm laser (500 Hz, 10 J, 200 mW) after injury, after 48 hours, three frogs were sacrificed by introducing the nerves in 10% formalin. The latency recorded by stimulating the sciatic nerve of frog to 0.5 mA and 100 ms in groups 1 and 2 show significant differences (p<0.001 and p<000) as in the amplitude (p<000 and p<000). Groups 3 and 4, which was stimulated at 100 mA and 100 ms latency showed no statistically significant difference (p>000), as to the extent, if any statistically significant difference. (p<0.001 and p<0.000). The laser produces a favorable response in the treatment of paresthesia (post‐traumatic neuropathy).
1226(2010); http://dx.doi.org/10.1063/1.3453773View Description Hide Description
Nd:YAG, currently used since 1970 in dental laboratories to weld metals on dental prostheses has some limits such great dimensions, high costs and fixed delivery system. Recently it was proposed the possibility to use the Nd:YAG laser device commonly utilised in dental office, to repair broken fixed, removable and orthodontic prostheses and to weld metals directly into the mouth.
The aim of this work is to value, through SEM (Scanning Electron Microscope), EDS (Energy Dispersive X‐Ray Spectroscopy) and DMA (Dynamic Mechanical Analysis), quality and mechanical strength of the welding process comparing a device normally used in dental lab and a device normally used in dental office for oral surgery.
Sixteen CoCrMo metal plates and twenty steel orthodontic wires were divided in four groups: one was welded without metal apposition by laboratory laser, one was welded with metal apposition by laboratory laser, one was welded without metal apposition by office laser and one was welded with metal apposition by office laser. The welding process was analysed by SEM, EDS and DMA to compare the differences between the different samples.
By SEM analysis it was seen that the plates welded by office laser without apposition metal showed a greater number of fissurations compared with the other samples. By EDS analysis it was seen a homogeneous composition of the metals in all the samples. The mechanical tests showed a similar elastic behaviour of the samples, with minimal differences between the two devices. No wire broke even under the maximum strength by the Analyser.
This study seems to demonstrate that the welding process by office Nd:YAG laser device and the welding process by laboratory Nd:YAG laser device, analysed by SEM, EDS and DMA, showed minimal and not significant differences even if these data will be confirmed by a greater number of samples.
1226(2010); http://dx.doi.org/10.1063/1.3453774View Description Hide Description
The laser illumination of holograms for public display is governed by international standard IEC 60825‐3, to which the Australian Standard AS/NZS 2211.3 conforms. These standards do not accommodate vital mitigating factors of hologram replay that impinge on the level of laser power i.e. angle of the replay reference beam, the divergence of the beam, the distance of the viewer from the holographic plate and the diffraction efficiency of the hologram plate itself. Such factors indicate that a more meaningful calculation of the radiation level would be obtained from direct measurement at the position of the viewer of the hologram. The purpose of this paper is to demonstrate the importance of these factors in realistically determining the maximum permissible exposure (MPE) for viewers of large format holograms. Materials and Methods: A comparison is made between measurements based on the power or energy that can pass through a fully open pupil for Class 3B and Class 4 lasers (1. medical copper bromide laser, 2. diode laser, and 3. argon continuous wave laser), and the actual power levels when the measurement is taken from the beholder’s point of view. Discussion and conclusion: these results indicate a need to review current standards.
1226(2010); http://dx.doi.org/10.1063/1.3453775View Description Hide Description
Extracellular matrices (ECMs) are currently applied in reconstructive surgery to enhance wound healing and tissue remodelling. Sutures and staples are usually employed to stabilize ECM on tissue although they may damage the matrix structure. In this investigation, a novel biocompatible bandage was developed to implant ECM on tissue without sutures. An adhesive film, based on chitosan, was integrated with small intestine submucosa (SIS) in a single bandage strip. This bandage was bonded to sheep small intestine upon laser irradiation of the chitosan film to assess tissue adhesion strength. Thermocouples were used to estimate temperatures under SIS during laser irradiation. The bandage successfully bonded to intestine achieving a shear stress of During laser irradiation, the temperature increased modestly to beneath the ECM portion of the bandage. The SIS‐chitosan bandage bonded effectively to tissue without sutures and preserved the ECM structure avoiding irreversible thermal denaturation of imbedded bioactive proteins.