Carlos José de Lima

Anti-Inflammatory Effect of Low-Level Laser and Light-Emitting Diode in Zymosan-Induced Arthritis

OBJECTIVE The aim of this work was to investigate the effect of low-level laser therapy (LLLT) and light-emitting diode (LED) on formation of edema, increase in vascular permeability, and articular joint hyperalgesia in zymosan-induced arthritis. BACKGROUND DATA It has been suggested that low-level laser and LED irradiation can modulate inflammatory processes. MATERIAL AND METHODS Arthritis was induced in male Wistar rats (250-280 g) by intra-articular injection of zymosan (1 mg in 50 microL of a sterile saline solution) into one rear knee joint. Animals were irradiated immediately, 1 h, and 2 h after zymosan administration with a semiconductor laser (685 nm and 830 nm) and an LED at 628 nm, with the same dose (2.5 J/cm(2)) for laser and LED. In the positive control group, animals were injected with the anti-inflammatory drug dexamethasone 1 h prior to the zymosan administration. Edema was measured by the wet/dry weight difference of the articular tissue, the increase in vascular permeability was assessed by the extravasation of Evans blue dye, and joint hyperalgesia was measured using the rat knee-joint articular incapacitation test. RESULTS Irradiation with 685 nm and 830 nm laser wavelengths significantly inhibited edema formation, vascular permeability, and hyperalgesia. Laser irradiation, averaged over the two wavelengths, reduced the vascular permeability by 24%, edema formation by 23%, and articular incapacitation by 59%. Treatment with LED (628 nm), with the same fluence as the laser, had no effect in zymosan-induced arthritis. CONCLUSION LLLT reduces inflammatory signs more effectively than LED irradiation with similar irradiation times (100 sec), average outputs (20 mW), and energy doses (2 J) in an animal model of zymosan-induced arthritis. The anti-inflammatory effects of LLLT appear to be a class effect, which is not wavelength specific in the red and infrared parts of the optical spectrum.

Photodynamic Antifungal Therapy Against Chromoblastomycosis

Photodynamic therapy (PDT) is a minimally invasive approach, in which a photosensitizer compound is activated by exposure to light. The activation of the sensitizer drug results in several chemical reactions, such as the production of reactive oxygen species and other reactive molecules, which presence in the biological site leads to the damage of target cells. Although PDT has been primarily developed to combat cancerous lesions, this therapy can be employed for the treatment of several conditions, including infectious diseases. A wide range of microorganisms, including Gram-positive and Gram-negative bacteria, viruses, protozoa, and fungi, have demonstrated susceptibility to antimicrobial PDT. This treatment might consist in an alternative for the management of fungal infections. Antifungal photodynamic therapy has been successfully employed against Candida species, dermatophytes, and Aspergillus niger. Chromoblastomycosis is an infection that involves skin and subcutaneous tissues caused by the traumatic inoculation of dematiaceous fungi species, being that the most prevalent are Fonsecaea pedrosoi and Claphialophora carrionii. In the present work, the clinical applications of PDT for the treatment of chromoblastomycosis are evaluated. We have employed methylene blue as photosensitizer and a LED (Light Emitting Diode) device as light source. The results of this treatment are positive, denoting the efficacy of PDT against chromoblastomycosis. Considering that great part of the published works are focused on in vitro trials, these clinical tests can be considered a relevant source of information about antifungal PDT, since its results have demonstrated to be promising. The perspectives of this kind of treatment are analyzed in agreement with the recent literature involving antifungal PDT.

Analgesic Effect of Light‐Emitting Diode (LED) Therapy at Wavelengths of 635 and 945 nm on Bothrops moojeni Venom‐Induced Hyperalgesia

Envenoming induced by Bothrops snakes is characterized by drastic local tissue damage involving hemorrhage, myonecrosis and proeminent inflammatory and hyperalgesic response. The most effective treatment is antivenom therapy, which is ineffective in neutralizing the local response. Herein, it was evaluated the effectiveness of light‐emitting diode (LED) at wavelengths of 635 and 945 nm in reducing inflammatory hyperalgesia induced by Bothrops moojeni venom (BmV) in mice, produced by an subplantar injection of BmV (1 μg). Mechanical hyperalgesia and allodynia were assessed by von Frey filaments at 1, 3, 6 and 24 h after venom injection. The site of BmV injection (1.2 cm2) was irradiated by LEDs at 30 min and 3 h after venom inoculation. Both 635 nm (110 mW, fluence of 3.76 J/cm2 and 41 s of irradiation time) and 945 nm (120 mW, fluence of 3.8 J/cm2 and 38 s of irradiation time) LED inhibited mechanical allodynia and hyperalgesia of mice alone or in combination with antivenom treatment, even when the symptoms were already present. The effect of phototherapy in reducing local pain induced by BmV should be considered as a novel therapeutic tool for the treatment of local symptoms induced after bothropic snake bites.

Effect of incoherent LED radiation on third-degree burning wounds in rats

Abstract The main physiological characteristics in a burn process are the increase of the capillary permeability and the occurrence of edema and exudation. Light-emitting diode (LED) has been proposed as treatment of burning. This study investigated the effects of LED on the repair process of rat skin submitted to a third-degree burning. The lesions were produced on the dorsal surface of male Wistar rats. Animals were divided into 4 groups (n = 6) as follows: L1 and L2 groups as LED-treated burned rats, and received LED therapy along 7 and 15 days with 48 hours intervals, respectively; C1 and C2 groups as control, non-treated burned rats. A red LED (640 nm, 30 mW) operating with a fluence of 4 J/cm2 was used. The wound area was measured daily after irradiation. Animals were euthanized at the 8th and 16th days after burning, and the wound fragment was submitted to histology. The inflammatory cells as well as the damaged area at the 8th day after burns were significantly lower for the LED-treated group when compared to control. Furthermore, the LED phototherapy effect on cellular migration was even more pronounced at the 16th day. Our results indicated that the treatment with a LED system was clearly effective in reducing the number of inflammatory cells and improving the healing process in an experimental model of third-degree burnings.

Optical Fiber Catheter with Distal End Bending Mechanism Control for Raman Biospectroscopy

Abstract This work proposes the development of an optical catheter with bending control of the distal end. The probe consists of seven optical fibers wrapped in a resin and a biocompatible flexible teflon tube with a novel mechanical device that allows bending of the distal extremity to access a desired location of a human organ. A central fiber is used for tissue Raman excitation, five fibers are used for Raman signal collection, and the seventh for “optoclinical” treatment applications. Infrared, dispersive Raman spectra at 785 nm excitation were employed to optically characterize the proposed catheter. An excitation transmission loss of 16% was found compared to the traditional six collecting fibers catheter, both with their distal tip straight. By bending of the distal tip at different angles, with turning the intermediated section of the catheter around cylinders of different diameters (one finds a correlation between curvature angle of the tip and cylinder diameter), the transmission loss coefficient and transmission were determined for each distal tip angle. A transmission reduction of 5% was found for a 180° curvature. This optical catheter could be very useful in clinics, providing a way to control the fiber tip position and angle onto the tissue or organ.

In vitro photodynamic therapy against Foncecaea pedrosoi and Cladophialophora carrionii

Photodynamic therapy (PDT) has been originally developed for cancer treatment, but recently, it has been successfully employed against microorganisms, including fungi. Chromoblastomycosis is a subcutaneous fungal infection that is recalcitrant to conventional antifungal drug therapy. The most frequent species involved are Foncecaea pedrosoi and Cladophialophora carrionii. The present study aimed to verify the efficacy in vitro of PDT employing methylene blue (MB) as a photosensitiser and Light emmiting diode (LED) (InGaAl) as the light source. Methylene blue at the concentrations of 16, 32 and 64 μg/mL and LED (InGalP) were employed for 15 min against spores of two isolates of F. pedrosoi and two isolates of C. carrionii. The spores were plated on Sabouraud Dextrose agar and the number of colony forming units was counted after 7–10 days of incubation at 37 °C. The PDT with MB and LED was efficient in reducing the growth of all samples tested. Better results were obtained for the concentration of 32 μg/mL of MB. The treatment proved to be highly effective in killing the samples of F. pedrosoi and Cladophialophora pedrosoi tested in vitro. PDT arises as a promising alternative for the treatment of this subcutaneous infection.

Optimizing the Raman signal for characterizing organic samples: The effect of slit aperture and exposure time

The present work is focused on the influence of the slit aperture and time exposure of the infrared light on the Charge Coupled Device (CCD) in relation to their physical effects, in order to improve the Raman spectrum characteristics. Indeed, the alterations in slit aperture and CCD time exposure affect significantly important spectral properties, such as the spectral intensity, Signal to Noise Ratio (SNR) and band width resolution of the Raman spectra. Therefore, the present proposal has the aim of to found the optimum conditions of instrumental arrangement, involving the minimum collection time and maximum signal quality in dispersive Raman spectrometers. Samples of dehydrated human teeth and naphthalene were evaluated with a Raman dispersive spectrometer employing excitation wavelength of 830 nm in several integration times and spectrometer slit apertures. The analysis of the spectral intensity, SNR and band width of selected Raman peaks allowed to infer that these properties of a dispersive Raman spectrum depend directly of the exposure time on the detector as well as spectrograph slit aperture. It is important to register that the higher SNR was obtained with higher exposure time intervals. To the samples evaluated in the present article, the band width has lower values for slit apertures of 100-150 µm, i.e., in this aperture range the spectral resolution is maximum. On the other hand, the intensity and SNR of the Raman spectra becomes optimal for slit apertures of 150-200 µm, since this aperture does not affect significantly the integrity of the Raman signal. In this way, we can to propose that in approximately 150 µm, it is possible to obtain an optimum condition, involving spectral resolution as well as SNR and spectral intensity. In any case, depending of the priorities of each spectral measurement, the instrumental conditions can be altered according with the necessities of each specific chemical analysis involving a determined sample. The present data are discussed in details in agreement with recent data from literature.

Use of Ozonated Water for Disinfecting Gastrointestinal Endoscopes

ABSTRACT The reprocessing of endoscopes is a complex procedure due to their structural design. In the constant search for new antimicrobial substances, recent studies with ozone have yielded great benefits. The present study evaluated the effects of ozonated water used to disinfect endoscopes comparing its efficacy with the conventional technique (2% glutaraldehyde). According to the results obtained, when ozonated water was used (330 mg.min.L−1), induced a 2 log reduction of the viable microorganisms under the conditions tested. Ozonated water was a potent gastrointestinal endoscopic sanitizer, suggesting it is a feasible alternative for disinfection.

Characterization of nutritional parameters in bovine milk by Raman spectroscopy with least squares modeling

ABSTRACT The macronutrient constitution of bovine milk was investigated by Raman spectroscopy involving 830 nm excitation at 300 mW from 600–1800 cm−1 with a probe. Bovine milk was analyzed for total proteins, casein, total fat, and lactose by standard assays. The concentrations of these components were estimated by correlating these assays with the fitting coefficients based on least-squares fitting of lactose, casein, triolein, and stearic acid and milk spectra to prepare calibration curves. The model was employed for the analysis of milk from local markets. The spectra of milk were dominated by bands of proteins, lipids, and carbohydrates. There was a strong correlation between the concentrations of total proteins and casein (r = 0.75 and 0.73, respectively), and very strong correlation for total fat and lactose (r = 0.93 and 0.91, respectively) with the standard errors of prediction of 0.49, 0.38, 0.61, and 0.27 mg/dL, respectively. The milk contained lower concentrations of lactose and protein than in the nutritional facts table. The amount of saturated fat was close to the nutritional value with more unsaturated fat. A single Raman spectrum was employed to characterize the composition of milk and may have application for rapid quality control.

Disinfection of Dental Instruments Contaminated with Streptococcus mutans Using Ozonated Water Alone or Combined with Ultrasound

Ozone gas diluted in water has been shown to produce significant results in terms of the elimination of microorganisms. Streptococcus mutans is the etiologic agent of dental caries. Methods using water containing ozone and an ultrasonic cleaner were employed for the disinfection of a curette. Streptococcus mutans was grown in a selective medium. The curette was submitted to disinfection by water containing ozone, by ultrasound, and then both techniques were combined. The results show that either method produced a significant microbial reduction, but the efficacy of both methods combined was greater. This method of disinfection proved to be both viable and cheap.