Effect of Low-Level Laser Therapy on Mast Cells in Second-Degree Burns in Rats

Efficacy of photobiomodulation in the treatment of oral mucositis in patients undergoing antineoplastic therapy: systematic review and meta-analysis

PURPOSE

To evaluate the effectiveness of photobiomodulation in the treatment of oral mucositis.

METHODS

Systematic review and meta-analysis encompassing in the electronic databases: LILACS, MEDLINE, EMBASE, COCHRANE, SCOPUS, WEB OF SCIENCE, and CINAHL and in http://clinicaltrials.gov . Eligibility criteria were randomized, non-randomized, and observational studies that used photobiomodulation for the treatment of oral mucositis. The endpoints were reduction in the severity of oral mucositis, duration of lesions, and pain reduction. For data analysis, the Review Manager 5.4 program was used.

RESULTS

A total of 316 studies were identified, 297 in the electronic databases and 19 in http://clinicaltrials.gov . After removing duplicates, 260 studies were selected for title and abstract reading, of which 223 were excluded. A total of 37 studies were chosen for full reading, of which 6 were included in the review, totaling 299 patients. The treatment used was photobiomodulation. The patients were divided into two groups: the laser group used only photobiomodulation or associated with other therapies, and the control group did not use photobiomodulation. For the endpoint reduction in the severity of oral mucositis (OM), the chance of reduction of the OM was greater in the laser group as compared to the control group. For the endpoints duration of OM lesions and pain reduction, it was not possible to carry out a meta-analysis due to the high heterogeneity between studies. In the interpretation of the meta-analysis, the reduction in the severity of oral mucositis was greater in the group that received photobiomodulation.

CONCLUSION

Photobiomodulation was effective in the treatment of oral mucositis.

Burn-Induced Local and Systemic Immune Response: Systematic Review and Meta-Analysis of Animal Studies

As burn injuries are often followed by a derailed immune response and excessive inflammation, a thorough understanding of the occurring reactions is key to prevent secondary complications. This systematic review, that includes 247 animal studies, shows the post-burn response of 14 different immune cell types involved in immediate and long-term effects, in both wound tissue and circulation. Peripheral blood neutrophil and monocyte numbers increased directly after burns, whereas thrombocyte numbers increased near the end of the first week. Lymphocyte numbers, however, were decreased for at least two weeks. In burn wound tissue, neutrophil and macrophage numbers accumulated during the first three weeks. Burns also altered cellular functions as we found increased migratory potential of leukocytes, impaired antibacterial activity of neutrophils and enhanced inflammatory mediator production by macrophages. Neutrophil surges were positively associated with burn size and were highest in rats. Altogether, this comprehensive overview of the temporal immune cell dynamics shows that unlike normal wound healing, burn injury induces a long-lasting inflammatory response. It provides a fundamental research basis to improve experimental set-ups, burn care and outcome.

Low-level laser therapy for the treatment of early stage cutaneous leishmaniasis: A pilot study

Low-Level Laser Therapy (LLLT) has been investigated for the treatment of various dermatological disorders. Here, we investigate the efficacy of LLLT for the treatment of cutaneous leishmaniasis (CL). This study comprised of 53 patients (total 123 lesions) with a confirmed diagnosis of CL via positive smear of LD-bodies. The CL lesions were classified in Grade I (ie, papule of size ≤1 cm) to Grade V (ie, vesicle formation, ulceration, and superadded infection of size >4 cm). All the patients were divided into group 1 with low grade (ie, Grade I and II) CL lesions and group 2 with high-grade disease (ie, Grade III-V). Red laser light (wavelength = 635 nm) was used for the lesion irradiation, with a light dose of 75 J/cm2 and at a low power of 300 mW. The treatment was divided into four sessions, one session per week. Disease assessment at 10 months follow-up revealed complete response in 91% and partial response in 9% patients of group 1, while no response was observed in patients of group 2. LLLT offers a promising treatment modality for patients presenting with early-stage (ie, Grade I and II) CL lesions.

Evaluation of the effect of photodynamic therapy on chemotherapy induced oral mucositis

BACKGROUND

In this study the effect of photodynamic therapy on chemotherapy induced mucositis was evaluated.

METHODS

This randomized single blind clinical pilot evaluation evaluated the effect of PDT with methylene blue on 15 patients with chemotherapy induced bilateral oral mucositis. They were divided into 2 groups (control side and intervention side). Methylene blue was applied on the lesions of both sides, after 10 min the lesion of intervention side was irradiated by a 660 nm diode laser InGaAlP(Azor-2 K) for 10 min (power: 25 mW, dose:19.23 J/CM2, probe diameter: 0.78 cm2) for three sessions (day1,3,5) and followed on day 12. In control side only sham laser was used. Data were analyzed by Wilcoxon and Mann-Whitney test using SPSS version 22.

RESULTS

Comparing the WCCNR and NCI difference in different sessions between intervention and control group, represented significant improvement in oral mucositis in photodynamic therapy group for sessions 1-0, 2-0, 3-0 (P.value<0.05).

CONCLUSION

Photodynamic therapy can improve chemotherapy induced oral mucositis.

Skin regenerative medicine advancements in the Islamic Republic of Iran: a concise review

In the last decade, the Islamic Republic of Iran has witnessed significant improvement and growth in the field of interdisciplinary medicine and in its translation to patients, including the field of cell and stem cell therapy. The main aim of this report is to highlight various advances in regenerative medicine for skin and dermatology using stem cell technology, and its translation to clinic in the past two decades, in Iranian academic centers, clinical institutes and hospitals. While there have been numerous positive advances in clinical outcomes reported in Iran, there is no comparative analytical information on these studies. Here we present a historical overview of the progress and key advancements seen in skin regeneration in this country, review the research frameworks, regulatory approach and pathways and offer perspectives for the future.

Phenotypic assays in yeast and zebrafish reveal drugs that rescue ATP13A2 deficiency

Mutations in ATP13A2 (PARK9) are causally linked to the rare neurodegenerative disorders Kufor-Rakeb syndrome, hereditary spastic paraplegia and neuronal ceroid lipofuscinosis. This suggests that ATP13A2, a lysosomal cation-transporting ATPase, plays a crucial role in neuronal cells. The heterogeneity of the clinical spectrum of ATP13A2-associated disorders is not yet well understood and currently, these diseases remain without effective treatment. Interestingly, ATP13A2 is widely conserved among eukaryotes, and the yeast model for ATP13A2 deficiency was the first to indicate a role in heavy metal homeostasis, which was later confirmed in human cells. In this study, we show that the deletion of YPK9 (the yeast orthologue of ATP13A2) in Saccharomyces cerevisiae leads to growth impairment in the presence of Zn2+, Mn2+, Co2+ and Ni2+, with the strongest phenotype being observed in the presence of zinc. Using the ypk9Δ mutant, we developed a high-throughput growth rescue screen based on the Zn2+ sensitivity phenotype. Screening of two libraries of Food and Drug Administration-approved drugs identified 11 compounds that rescued growth. Subsequently, we generated a zebrafish model for ATP13A2 deficiency and found that both partial and complete loss of atp13a2 function led to increased sensitivity to Mn2+. Based on this phenotype, we confirmed two of the drugs found in the yeast screen to also exert a rescue effect in zebrafish-N-acetylcysteine, a potent antioxidant, and furaltadone, a nitrofuran antibiotic. This study further supports that combining the high-throughput screening capacity of yeast with rapid in vivo drug testing in zebrafish can represent an efficient drug repurposing strategy in the context of rare inherited disorders involving conserved genes. This work also deepens the understanding of the role of ATP13A2 in heavy metal detoxification and provides a new in vivo model for investigating ATP13A2 deficiency.

Photobiomodulation and bacterial cellulose membrane in the treatment of third-degree burns in rats

Burns are injuries caused mainly by thermal trauma, which can progress to unsatisfactory results healing. This study aimed to evaluate the biomaterial (bacterial cellulose membrane) and photobiomodulation, exclusively and associated, in the treatment of third degree burns in rats. Forty male Wistar rats (±280 g) were randomly divided into four groups, with 10 animals each: control group (CG); bacterial cellulose membrane group (MG); laser group (LG) and bacterial cellulose membrane and laser group (MG + L). The burn was caused with a 1 cm² aluminum plate heated to 150 °C and pressed on the animal's back for 10 s. The treatments were started immediately after induction of injury. For to laser irradiation (660 nm, 100 mW, 25 J/cm² and energy of 1 J) on five distinct application points were used, on alternate days, a total of five sessions. After ten days of treatment the animals were euthanized for collected samples. One-way ANOVA and Tukey's tests (P < 0.05) were used. Histological analysis revealed differences regarding the healing process phase in each experimental group. MG showed the proliferative phase. The LG demonstrated greater amount of blood vessels and immune expression of VEGF. However, when the treatments were combined, the number of vessels and the immune expression of VEGF factor was lower than LG. Thus, it was concluded that both treatments proposed (biomaterial and LLLT) are good alternatives for third degree burns when applied isolated because they stimulate the healing process by acting on the modulation of the inflammatory phase and promote stimulation of angiogenesis.

Effects of Photobiomodulation on Degranulation and Number of Mast Cells and Wound Strength in Skin Wound Healing of Streptozotocin-Induced Diabetic Rats

BACKGROUND

A lack of effective treatments still exists for patients suffering from diabetes mellitus. Photobiomodulation is proved as a beneficial therapeutic modality for wounds.

OBJECTIVE

The aim of this study is to examine the effect of degranulation of mast cells and total number of mast cells in the remodeling step of an ischemic model of wound healing under the influence of photobiomodulation and conditioned medium (CM) from human bone marrow-derived mesenchymal stem cells (hBM-MSCs-CM), or CM, administered alone and or in combination.

MATERIALS AND METHODS

Initially, type 1 diabetes mellitus was induced in 72 male adult rats. Then, after a month, one incision was made on the back of each rat. Subsequently, the rats were divided into four groups. The first group was considered as the control (placebo) group, the second group received CM, the third group received photobiomodulation, and the fourth group received photobiomodulation+CM. On days 4, 7, and 15, samples were extracted from the wound for histological and tensiometric examinations. The total number of mast cells, including the three types of mast cells, was counted by the stereological methods. The tensiometric properties of the repairing tissue were examined.

RESULTS

The administration of photobiomodulation and CM, alone or in combination, significantly increased the tensiometric properties within the healing wounds. Histologically, photobiomodulation+CM, CM, and photobiomodulation groups showed a significant decrease in the three types of mast cells and in the total number of mast cells compared with the control group on day 15.

CONCLUSIONS

We conclude that photobiomodulation and CM alone and or in combination significantly accelerated the healing process in a rat with a diabetic and ischemic wound, and significantly decreased the total number of mast cells and degranulation of mast cells. We suggest that the increased number of type 2 mast cells in the control group adversely affected the tensiometric properties of wounds in this group.

Furaltadone suppresses IgE-mediated allergic response through the inhibition of Lyn/Syk pathway in mast cells

Mast cells are critical cells that prompt various allergic response-inducing factors, contributing to allergic diseases. While used as an antibiotic for livestock, there is no study on the effect of furaltadone on allergic response. This study investigated the effect of furaltadone on mast cells and passive cutaneous anaphylaxis (PCA). Furaltadone inhibited the degranulation of mast cells stimulated by antigen (IC₅₀, ~ 3.9 μM), and also suppressed the production of tumor necrosis factor (TNF)-α and interleukin (IL)-4 in a concentration dependent manner. In addition, furaltadone inhibited allergic responses in an acute allergy animal model, PCA. Further investigation on the mechanism for these inhibitory effects of furaltadone found that the activities of Lyn/Syk and Syk-dependent downstream proteins such as mitogen-activated protein (MAP) kinases were inhibited by furaltadone in mast cells. Taken together, this study demonstrates that furaltadone inhibits the activation of mast cells by antigen via the suppression of the Lyn/Syk pathway and ameliorates allergic responses in vivo.

Effect of 670 nm laser photobiomodulation on vascular density and fibroplasia in late stages of tissue repair

This study aimed to investigate the effects of gallium-aluminum-arsenium (GaAlAs) (670 nm) laser therapy on neoangiogenesis and fibroplasia during tissue remodelling. Forty male Wistar rats underwent cutaneous surgery and were divided into 2 experimental groups: the Control and Laser group (9 mW, 670 nm, 0.031 W/cm² , 4 J/cm² ). After 14, 21, 28, and 35 days, the animals were euthanised. Descriptive and quantitative analyses were performed in sections stained with haematoxylin-eosin and Sirius Red, respectively. The amounts of VEGF+ and CD31+ cells were evaluated by immunohistochemistry and histomorphometric analysis, respectively. Statistical analysis was performed using the Mann-Whitney, Friedman, and Spearman correlation test, P < 0.05. The collagen expression was significantly higher in the laser group compared with the control group on days 14 and 21 after the creation of the skin wound (P = 0.008; P = 0.016) and in the control group between 14 and 28 and 14 and 35 days (P = 0.001; P = 0.007). There were more blood vessels in three periods of the study only in the (Laser) treated group, with statistical significance at day 14 (P = 0.016). There was no statistically significant difference in VEGF+ cell count in the different experimental groups throughout the study, although a positive correlation was shown with the area of collagen on days 14 and 28 (P = 0.037). Laser treatment had a positive effect in the late course of healing, particularly with regards to collagen expression and the number of newly formed vessels. VEGF+ cells were present in both experimental groups, and VEGF appeared to influence fibroplasia in the treated group.

Synthesis and retention properties of molecularly imprinted polymers for antibiotics containing a 5-nitrofuran ring

Impedimetric sensor based on molecularly imprinted polymers synthetized for antibiotics containing a 5-nitrofuran ring.

Comparative effects of two different doses of low-level laser therapy on wound healing third-degree burns in rats

Burns are injuries caused by direct or indirect contact to chemical, physical, or biological agents. Low-level laser therapy (LLLT) is a promising treatment since it is low-cost, non-invasive, and induces cell proliferation. This study aimed to investigate the effects of LLLT (660 nm) at two different fluences (12.5 J/cm(2) and 25 J/cm(2) ) per point of application on third-degree burns in rats. Thirty rats (Wistar) divided into GC, GL12.5, and GL25 were used in the study, and submitted to burn injury through a soldering iron at 150°C, pressed on their back for 10 s. LLLT was applied immediately, and 2, 4, 6, and 8 days after wound induction. Histological analysis revealed a decreased inflammatory infiltrate in the group treated with 25 J/cm(2) , and intense inflammatory infiltrate in the control group and in the group treated with 12.5 J/cm(2) . The immunostaining of COX-2 was more intense in the control groups and in the group treated with 12.5 J/cm(2) than in the group treated with 25 J/cm(2) . Conversely, VEGF immunomarking was more expressive in the group treated with 25 J/cm(2) than it was in the other two groups. Therefore, our findings suggest that the use of 25 J/cm(2) and 1 J of energy was more effective in stimulating the cellular processes involved in tissue repair on third-degree burns in rats by reducing the inflammatory phase, and stimulating angiogenesis, thus restoring the local microcirculation which is essential for cell migration.

Effect of low-level laser therapy (λ660 nm) on angiogenesis in wound healing: a immunohistochemical study in a rodent model

The aim of the present investigation was to evaluate the angiogenesis on dorsal cutaneous wounds in a rodent model treated with λ660 nm laser light. New vessel formation is a multistep process involving vessel sprouting, endothelial cell migration, proliferation and tube formation. Although several in vivo studies have shown that laser phototherapy influences tissue repair, a fully understanding of angiogenesis mechanisms are not yet known. Twenty-four young adult male Wistar rats weighing between 200 and 250 g were used. Under general anesthesia, one excisional wound was created on the dorsum of each animal and they were randomly distributed into two groups: one control and one treated with laser (λ660 nm, 16 mW, 10 J/cm2). Each group was subdivided into three subgroups according to the animal death timing (2, 4 and 6 days). Laser irradiation started immediately after surgery and was repeated every other day during the experiment and marked with Sirius Red, specific for collagen, and immunomarked with anti-TGF-β and anti-von Willebrand factor. Marked sections underwent histological analysis by light microscopy and the mean area of the wound of each animal was calculated and analyzed by ANOVA and Tukey's test (α=0.05). Although at some death periods, collagen expression and number of blood vessels on irradiated animals were higher than in the control ones, no significant differences were found at any time in relation to TGF-β expression (p>0.05). It was concluded that laser treatment (λ660 nm) contributed to increase angiogenesis.

Macroscopic effect of blue light cure on wound healing in NMRI mice NMRI

Background:

Wound healing is a complex process and has been an ongoing challenge all over the world. Some studies have suggested light cure as a modality to accelerate wound repair. It can induce fibroblast proliferation, increase collagen synthesis and activate cellular processes involved in expression of procollagen type I and III mRNA. This study was designed to assess the macroscopic effect of halogen dental curing blue light on full-thickness open wound healing in NMRI mice.

Materials and Methods:

Forty male NMRI mice were divided into control and treatment groups. A full-thickness wound of 6 mm in diameter was induced on the lower back of all mice under general anesthesia and sterile conditions. The mice of the treatment group received a 5-min exposure of halogen light Coltolux II (QHL), 420-500 nm, daily for 7 days. The diameter of the wound was measured in both the treatment and the control groups every second day up to Day 14. Data were analyzed by SPSS version 12 software using Student's t-test. A significance level of P ≤ 0.05 was considered for each comparison.

Results:

There was a significant difference in wound diameter between the control and the treatment groups at all measurements after Day 3 (P ≤ 0/05).

Conclusion:

The results of this study suggest improvement of full-thickness wound healing by daily irradiation of halogen dental curing blue light of 420-500 nm for 7 days.

A novel 2-(2-methyl-2-nitrovinyl)-furan ectoparasitic drug: physicochemical characterization and determination of the raw material by gas chromatography mass spectrometry

2-(2-methyl-2-nitrovinyl)-furan (NVF) has recently been synthesized and the pharmaceutical industry interest in this compound has grown due to its antibacterial, fungicidal and anti-ectoparasitic activities. Therefore, the physicochemical characterization of new drug was conducted. In addition, two rapid, simple and suitable GC methods were developed for determination of NVF. Analyses were carried out with an Agilent DB-5ms capillary column (60 m × 0.25 mm i.d., 0.25 µm film thickness). The GC-FID analysis employed splitless mode of injection, oven/injector/detector temperature of 160/230/280°C and nitrogen carrier at the flow of 5.0 mL min−1. The GC-MS analysis employed splitless mode of injection, helium carrier at the flow of 1.5 mL min−1, column temperature program with 2 min at 100°C, ramp at 50°C min−1 to 260°C and injector and detector temperature of 250 and 290°tC, respectively. The MS conditions were ionization voltage, 70 eV; mass range, m/z 40–350; and ion source temperature, 200°C. The analysis time took less than 6 min. The results obtained in the validation of the methods suggest that these methods are economic, precise, accurate and linear over the range of analysis. The methods were successfully employed during the synthesis of NVF in order to ensure the quality of the raw material.

Effect of low-level treatment with an 80-Hz pulsed infrared diode laser on mast-cell numbers and degranulation in a rat model of third-degree burn

BACKGROUND DATA

Low-level laser therapy (LLLT) has been reported to be capable of changing mast cell numbers and degranulation in experimental burns in rats.

OBJECTIVE

We conducted a study of the influence of LLLT on mast cells in a rat model of third-degree burn.

METHODS

In this study we divided 48 rats equally into two groups of 24 rats each. Third-degree burns were inflicted at three different locations on each rat in each group. The first burn site on rats in group I was treated with 890-nm pulsed laser, 75W peak, 80 Hz, 180 ns, average power 1mW, illuminated area 1 cm(2), 1 mW/cm(2), 856 sec, 0.924 J/cm(2). The second burn site on both groups of rats was treated with 0.2% nitrofurazone cream. Mast cell numbers and degranulation at each burn site on each group of rats were then assessed at 4, 8, 13, and 20 days after the infliction of burns.

RESULTS

Analysis of variance on day 4 showed that the total numbers of mast cells were significantly lower at the laser-treated burn sites than at other burn sites on both groups of rats. On day 8 the total numbers of mast cells were again significantly lower at the laser-treated burn sites than at other burn sites, and on day 13, the numbers of both types 1 and 2 mast cells were significantly lower at the laser-treated burn sites than at other burn sites.

CONCLUSIONS

We conclude that LLLT can significantly decrease total numbers of mast cells during the proliferation and remodeling phases of healing in a rat model of third-degree burn.

Influence of 670 nm low-level laser therapy on mast cells and vascular response of cutaneous injuries

Laser biomodulation has been getting considerable attention when it comes to its effects on the inflammatory process. Its action upon mast cells have been already studied, but none of the previous papers related the resulting effect to the inflammatory and vascular status of the wounds. Therefore, the acute inflammatory process as well as the mast cells behavior and the vascular response were analyzed under the influence of laser treatment on cutaneous wounds. Surgical procedures were performed on 60 rats divided into sham and laser groups. Low-level laser therapy was performed following surgical procedures (670 nm, 9 mW, 4 J/cm(2), 124 s). Histological specimens were analyzed for cell morphology and immunohistochemistry using anti-von Willebrand Factor and anti-Vascular Endothelial Growth Factor antibody. Laser treatment resulted in an increased acute inflammatory response in irradiated tissues; surgical wounds treated with laser therapy had increased polymorphonuclear cells, mast cells and vasodilation and lower numbers of vessels than those in control rats. Laser treatment resulted in higher expression of VEGF in irradiated tissues 6-24h post-treatment (p=0.002). It is possible to observe an amplification of acute inflammatory process during the first hours after surgical procedure in rats submitted to laser therapy.

Effect of photodynamic therapy on the healing of cutaneous third-degree-burn: histological study in rats

The aim of this study was to conduct a histological assessment of the effect of photodynamic therapy (PDT) on the repairing of third-degree-burn wounds made on the backs of rats with a heated scalpel. Ninety-six rats were divided into groups: G1, control (n = 24), cold scalpel; G2, burned, heated scalpel (n = 24); G3, low-level laser therapy (LLLT) (n = 24), on burns; and G4, photodynamic therapy (PDT) (n = 24), toluidine-O blue (100 microg/ml) and LLLT treatment on burns. The laser (685 nm) was applied in continuous mode, 50 mW, 4.5 J/cm(2), contact mode at nine points (9 s/point). Eight animals in each group were killed at 3 days, 7 days or 14 days after surgery, and tissue specimens containing the whole wounded area were removed and processed for histological analysis; the results were statistically analyzed with Kruskal-Wallis and Dunn's tests (P < 0.05). The results demonstrated significant differences between G2 and G3, and between G2 and G4, at both 3 days and 7 days, with regard to acute inflammation scores; G1 and G2 showed significant differences when compared with G4 at 3 days, with regard to neo-angiogenesis scores; G1 and G2 were statistically different from G3 and G4 at both 3 days and 7 days, with regard to re-epithelization scores; G2 showed statistically significant differences when compared with G3 and G4 with regard to collagen fiber scores at 7 days. LLLT and PDT acted as a biostimulating coadjuvant agent, balancing the undesirable effect of the burn on the wound healing process, acting mainly in the early healing stages, hastening inflammation and increasing collagen deposition.