Effect of low-level laser therapy in an experimental model of osteoarthritis in rats evaluated through raman spectroscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Can low-level laser therapy when associated to exercise decrease adipocyte area?

Obesity affects approximately 20% of the world population, and exercise is the primary non-pharmacological therapy. The combined use of exercise and low-level laser therapy (LLLT) may potentiate the effects promoted by exercise. The objective of this study was to investigate the effects of exercise in combination with phototherapy on adipocyte area, activity of the enzyme citrate synthase and muscle morphological analysis. We used 64 Wistar rats, which were divided into eight groups with 8 rats each: sedentary chow-diet (SC); sedentary chow-diet plus laser therapy (SCL), exercised chow-diet (EC); exercised chow-diet plus laser therapy (ECL); sedentary high-fat diet (SH); sedentary high-fat diet plus laser therapy (SHL); exercised high-fat diet (EH); exercised high-fat diet, laser therapy (EHL). The animals were submitted to a program of swimming training for 90min/5 times per week for 8weeks and LLLT (GA-Al-AS, 830nm) at a dose of 4.7J/point and a total energy of 9.4J/animal, with duration of 47s, which was applied to both gastrocnemius muscles after exercise. We conclude that the combined use of exercise and phototherapy increases the activity of the enzyme citrate synthase and decreases the white adipocyte area epididymal, retroperitoneal and visceral in obese rats, enhancing the effects of exercise.

Effect of GaAIAs low-level laser therapy on the healing of human palate mucosa after connective tissue graft harvesting: randomized clinical trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High-level production of functional muscle alpha-tropomyosin in Pichia pastoris

Although numerous studies have reported the production of skeletal muscle alpha -tropomyosin in E. coli, the protein needs to be modified at the amino terminus in order to be active. Without these modifications the protein does not bind to actin, does not exhibit head-to-tail polymerization, and does not inhibit the actomyosin Mg2+-ATPase in the absence of troponin. on the other hand, the protein produced in insect cells using baculovirus as an expression vector (Urbancikova, M., and Hitchcock-DeGregori, S. E., J. Biol. Chem., 269, 24310-24315, 1994) is only partially acetylated at its amino terminal and therefore is not totally functional. In an attempt to produce an unmodified functional recombinant muscle alpha -tropomyosin for structure-function correlation studies we have expressed the chicken skeletal alpha -tropomyosin cDNA in the yeast Pichia pastoris. Recombinant protein was produced at a high level (20 mg/L) and was similar to the wild type muscle protein in its ability to polymerize, to bind to actin and to regulate the actomyosin S1 Mg2+-ATPase. (C) 2001 Academic Press.

Coherent properties and Rabi oscillations in two-level donor systems

Coherent properties and Rabi oscillations in two-level donor systems, under terahertz excitation, are theoretically investigated. Here we are concerned with donor states in bulk GaAs and GaAs-(Ga,Al)As quantum dots. We study confinement effects, in the presence of an applied magnetic field, on the electronic and on-center donor states in GaAs- (Ga,Al)As dots, as compared to the situation in bulk GaAs, and estimate some of the associated decay rate parameters. Using the optical Bloch equations with damping, we study the time evolution of the Is and 2p(+) states in the presence of an applied magnetic field and of a terahertz laser. We also discuss the role played by the distinct dephasing rates on the photocurrent and calculate the electric dipole transition moment. Results indicate that the Rabi oscillations are more robust as the total dephasing rate diminishes, corresponding to a favorable coherence time.

Evaluation of low intensity laser's action on silicone mammary implant pseudocapsules in rats

OBJETIVO: Avaliar o efeito do laser de baixa intensidade sobre a contração da pseudocápsula que ocorre ao redor de implantes de silicone. MÉTODOS: 60 ratos machos divididos em dois grupos receberam implante de silicone. Grupo I: implante no subcutâneo da região dorsal, sem tratamento após a cirurgia; Grupo II: animais receberam sete sessões de irradiação com laser de baixa intensidade após o implante. Trinta, 60 e 180 dias após a cirurgia, foi feita a tonometria dos implantes, em seguida, os animais foram sacrificados, removendo-se o material de estudo que foi preparado para exame histológico, avaliando-se morfometricamente a espessura da pseudocápsula e a reação inflamatória. A análise estatistica pela técnica da Análise de Variância e Teste de Tukey (P<0.0 5). RESULTADOS: Pressões significativamente menores foram encontradas nos animais do grupo Grupo II. O estudo histológico não mostrou diferença significativa entre os grupos, destacando-se apenas maior quantidade de vasos intumescidos no Grupo II. A espessura da pseudocápsula foi menor no Grupo II. CONCLUSÃO: O laser de baixa intensidade altera o processo de reparação tecidual ao redor dos implantes, sugerindo que o mesmo possa ser útil para a modelação das contraturas que se estabelecem ao redor dos implantes de silicone.

Comparison between laser therapy and non-surgical therapy for periodontitis in rats treated with dexamethasone

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Short-term clinical and immunologic effects of scaling and root planing with Er : YAG laser in chronic periodontitis

Background: Recently, the erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser has been used for periodontal therapy. This study compared Er:YAG laser irradiation (100 mJ/pulse, 10 Hz, 12.9 J/cm(2)) with or without conventional scaling and root planing (SRP) to SRP only for the treatment of periodontal pockets affected with chronic periodontitis.Methods: Twenty-one subjects with pockets from 5 to 9 mm in non-adjacent sites were studied. In a split-mouth design, each site was randomly allocated to a treatment group: SRP and laser (SRPL), laser only (L), SRP only (SRP), or no treatment (C). The plaque index (PI), gingival index (GI), bleeding on probing (BOP), and interleukin (IL)-1 beta levels in crevicular fluid were evaluated at baseline and at 12 and 30 days postoperatively, whereas probing depth (PD), gingival recession (GR), and clinical attachment level (CAL) were evaluated at baseline and 30 days after treatment. A statistical analysis was conducted (P<0.05).Results: Twelve days postoperatively, the PI decreased for SRPL and SRP groups (P<0.05); the GI increased for L, SRP, and C groups but decreased for the SRPL group (P<0.05); and BOP decreased for SRPL, L, and SRP groups (P<0.01). Thirty days postoperatively, BOP decreased for treated groups and was lower than the C group (P<0.05). PD decreased in treated groups (P<0.001), and differences were found between SRPL and C groups (P<0.05). CAL gain was significant only for the SRP group (P<0.01). GR increased for SRPL and L groups (P<0.05). No difference in IL-1 beta was detected among groups and periods.Conclusion: Er:YAG laser irradiation may be used as an adjunctive aid for the treatment of periodontal pockets, although a significant CAL gain was observed with SRP alone and not with laser treatment.

Clinical and Microbiologic Follow-Up Evaluations After Non-Surgical Periodontal Treatment With Erbium:YAG Laser and Scaling and Root Planing

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Low-power laser irradiation improves histomorphometrical parameters and bone matrix organization during tibia wound healing in rats

The influence of daily energy doses of 0.03, 0.3 and 0.9 J of He-Ne laser irradiation on the repair of surgically produced tibia damage was investigated in Wistar rats. Laser treatment was initiated 24 h after the trauma and continued daily for 7 or 14 days in two groups of nine rats (n=3 per laser dose and period). Two control groups (n=9 each) with injured tibiae were used. The course of healing was monitored using morphometrical analysis of the trabecular area. The organization of collagen fibers in the bone matrix and the histology of the tissue were evaluated using Picrosirius-polarization method and Masson's trichrome. After 7 days, there was a significant increase in the area of neoformed trabeculae in tibiae irradiated with 0.3 and 0.9 J compared to the controls. At a daily dose of 0.9 J (15 min of irradiation per day) the 7-day group showed a significant increase in trabecular bone growth compared to the 14-day group. However, the laser irradiation at the daily dose of 0.3 J produced no significant decrease in the trabecular area of the 14-day group compared to the 7-day group, but there was significant increase in the trabecular area of the 15-day controls compared to the 8-day controls. Irradiation increased the number of hypertrophic osteoclasts compared to non-irradiated injured tibiae (controls) on days 8 and 15. The Picrosirius-polarization method revealed bands of parallel collagen fibers (parallel-fibered bone) at the repair site of 14-day-irradiated tibiae, regardless of the dose. This organization improved when compared to 7-day-irradiated tibiae and control tibiae. These results show that low-level laser therapy stimulated the growth of the trabecular area and the concomitant invasion of osteoclasts during the first week, and hastened the organization of matrix collagen (parallel alignment of the fibers) in a second phase not seen in control, non-irradiated tibiae at the same period. The active osteoclasts that invaded the regenerating site were probably responsible for the decrease in trabecular area by the fourteenth day of irradiation. (C) 2003 Elsevier B.V. All rights reserved.

Analysis of plant LTR-retrotransposons at the fine-scale family level reveals individual molecular patterns

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mass spectrometric characterization of two novel inflammatory peptides from the venom of the social wasp Polybia paulista

The social wasp P. paulista is relatively common in southeast Brazil causing many medically important stinging incidents. The seriousness of these incidents is dependent on the amount of venom inoculated by the wasps into the victims, and the characteristic envenomation symptoms are strongly dependent on the types of peptides present in the venom. In order to identify some of these naturally occurring peptides available in very low amounts, an analytical protocol was developed that uses a combination of reversed-phase and normal-phase high-performance liquid chromatography (HPLC) of wasp venom for peptide purification, with matrix-assisted laser desorption/ionization time-of-flight post-source decay mass spectrometry (MALDI-Tof-PSD-MS) and low-energy collision-induced dissociation (CID) in a quadrupole time-of-flight tandem mass spectrometry (QTof-MS/MS) instrument for peptide sequencing at the sub-picomole level. The distinction between Leu and Ile was achieved both by observing d-type fragment ions obtained under CID conditions and by comparison of retention times of the natural peptides and their synthetic counterparts (with different combinations of I and/or L at N- and C-terminal positions). To distinguish the isobaric residues K and Q, acetylation of peptides was followed by Q-Tof-MS analysis. The primary sequences obtained were INWLKLGKMVIDAL-NH2 (MW 1611.98Da) and IDWLKLGKMVMDVL-NH2 (MW 1658.98Da). Micro-scale bioassay protocols characterized both peptides as presenting potent hemolytic action, mast cell degranulation, and chemotaxis of poly-morphonucleated leukocyte (PMNL) cells. The primary sequences and the bioassay results suggest that these toxins constitute members of a new sub-class of mastoparan toxins, directly involved in the occurrence of inflammatory processes after wasp stinging. Copyright (C) 2004 John Wiley Sons, Ltd.

Advantages of using nested collision induced dissociation/post-source decay with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: sequencing of novel peptides from wasp venom

We have examined the applicability of the 'nested' collision induced dissociation/post-source decay (CID/PSD) method to the sequencing of novel peptides from solitary wasps which have neurotoxic venom for paralyzing other insects. The CID/PSD spectrum of a ladder peptide derived from an exopeptidase digest was compared with that of the intact peptide. The mass peaks observed only in the CID/PSD spectrum of a ladder peptide were extracted as C-terminal fragment ions. Assignment of C-terminal fragment ions enabled calculation of N-terminal fragment masses, leading to differentiation between N-terminal fragment ions and internal fragment ions. This methodology allowed rapid and sensitive identification by removing ambiguity in the assignment of the fragment ions, and proved useful for sequencing unknown peptides, in particular those available as natural products with a limited supply. Copyright (C) 2000 John Wiley & Sons, Ltd.

The Effects of a 785-nm AlGaInP Laser on the Regeneration of Rat Anterior Tibialis Muscle After Surgically-Induced Injury

Objective: This study aims to investigate the effects of low-level laser therapy (LLLT) on muscle regeneration. For this purpose, the anterior tibialis muscle of 48 male Wistar rats received AlGaInP laser treatment (785 nm) after surgically-induced injury.Background Data: Few studies have been conducted on the effects of LLLT on muscle regeneration at different irradiation doses.Materials and Methods: The animals were randomized into four groups: uninjured rats (UN); uninjured and laser-irradiated rats (ULI); injured rats (IN); and injured and laser-irradiated rats (ILI). The direct contact laser treatment was started 24 h after surgery. An AlGaInP diode laser emitting 75 mW of continuous power at 785 nm was used for irradiation. The laser probe was placed at three treatment points to deliver 0.9 J per point, for a total dose of 2.7 J per treatment session. The animals were euthanized after treatment sessions 1, 2, and 4. Mounted sections were stained with hematoxylin and eosin and used for quantitative morphological analysis, in which the number of leukocytes and fibroblasts were counted over an area of 4480 mu m(2). The data were statistically analyzed by analysis of variance (ANOVA) and the Bonferroni t-test.Results: Quantitative data showed that the number of both polymorphonuclear and mononuclear leukocytes in the inflammatory infiltrate at the injury site was smaller in the ILI(1), ILI(2), and ILI(4) subgroups compared with their respective control subgroups (IN(1), IN(2), and IN(4)) for sessions 1, 2, and 4, respectively (p < 0.05). on the other hand, the number of fibroblasts increased after the fourth treatment session (p < 0.05). With regard to the regeneration of muscle fibers following injury, only after the fourth treatment session was it possible to find muscle precursor cells such as myoblasts and some myotubes in the ILI(4) subgroup.Conclusion: During the acute inflammatory phase, the AlGaInP laser treatment was found to have anti-inflammatory effects, reducing the number of leukocytes at the injury site and accelerating the regeneration of connective tissue.

Effect of GaAlAs Laser Irradiation on the Epiphyseal Cartilage of Rats

Objective: To study the effect of an 830-nm gallium-aluminum-arsenic (GaAlAs) diode laser at two different energy densities (5 and 15 J/cm(2)) on the epiphyseal cartilage of rats by evaluating bone length and the number of chondrocytes and thickness of each zone of the epiphyseal cartilage. Background Data: Few studies have been conducted on the effects of low-level laser therapy on the epiphyseal cartilage at different irradiation doses. Materials and Methods: A total of 30 male Wistar rats with 23 days of age and weighing 90 g on average were randomly divided into 3 groups: control group (CG, no stimulation), G5 group (energy density, 5 J/cm(2)), and G15 group (energy density, 15 J/cm(2)). Laser treatment sessions were administered every other day for a total of 10 sessions. The animals were killed 24 h after the last treatment session. Histological slides of the epiphyseal cartilage were stained with hematoxylin-eosin (HE), photographed with a Zeiss photomicroscope, and subjected to histometric and histological analyses. Statistical analysis was performed using one-way analysis of variance followed by Tukey's post hoc test. All statistical tests were performed at a significance level of 0.05. Results: Histological analysis and x-ray radiographs revealed an increase in thickness of the epiphyseal cartilage and in the number of chondrocytes in the G5 and G15 groups. Conclusion: The 830-nm GaAlAs diode laser, within the parameters used in this study, induced changes in the thickness of the epiphyseal cartilage and increased the number of chondrocytes, but this was not sufficient to induce changes in bone length.