Over the past decade, dramatic progress has been made in dental research areas involving laser therapy. The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster. Additionally, photobiomodulation therapy (PBMT), a non-invasive treatment, when applied in orthodontics, contributes to alleviating pain and reducing inflammation induced by orthodontic forces, along with improving tissue healing processes. Moreover, PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption (OIIRR) during orthodontic treatment (OT) due to its capacity to modulate inflammatory, apoptotic, and anti-antioxidant responses. However, a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement (OTM) in relation to OIIRR, casting doubt on its beneficial effects. In PBMT-assisted orthodontics, delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues. The penetration of light to the root surface is another crucial unknown factor. Both the penetration depth and distribution of light in periodontal tissues are unknown. Thus, advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations. This review explores possibilities for improving the application and effectiveness of PBMT during OTM. The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells, with a special focus on immunomodulatory effects during OTM.
Humans ; Inflammation ; Low-Level Light Therapy/adverse effects* ; Orthodontics ; Root Resorption/therapy* ; Tooth Movement Techniques

Low-level laser therapy (LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals (12-33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group (LG) or a placebo group (PG) (1:1). The LG received LLLT (810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale (NRS) of pain, pressure pain thresholds (PPTs), cold detection thresholds (CDTs), warmth detection thresholds (WDTs), cold pain thresholds (CPTs), and heat pain thresholds (HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance (ANOVA). The NRS pain scores were significantly lower in the LG group (P = 0.01). The CDTs, CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG (P < 0.033). The parameters tested also showed significantly less sensitivity on the non-treatment side of the LG compared to that of the PG (P < 0.043). There were no differences between the groups for any quantitative sensory testing (QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment. Further clinical applications are suggested.
Adolescent ; Adult ; Female ; Humans ; Low-Level Light Therapy ; methods ; Male ; Pain Management ; Pain Measurement ; Pain Threshold ; physiology ; Tooth Movement Techniques ; adverse effects ; Toothache ; etiology ; radiotherapy ; Treatment Outcome ; Young Adult

The present study aimed to improve the processing of data acquired from laser speckle contrast imaging (LSCI) to provide a standardization method to explore changes in regional cerebral blood flow (rCBF) and to determine the correlations among rCBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic (PT) ischemia. rCBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized rCBF (SrCBF), defined as the ratio of rCBF measured in the ipsilateral region of interest (ROI) to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and SrCBF were analyzed over time. The results showed that the cortical rCBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with SrCBF in the ischemic region. Changes in the microvascular density were similar to those observed in SrCBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical rCBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and SrCBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.
Animals ; Brain Ischemia ; diagnostic imaging ; etiology ; Cerebrovascular Circulation ; Diagnostic Imaging ; methods ; Intracranial Thrombosis ; diagnostic imaging ; etiology ; Laser-Doppler Flowmetry ; methods ; Light ; adverse effects ; Male ; Mice ; Mice, Inbred C57BL

Monoclonal immunoglobulin deposition disease is rare in medical practice. The light and heavy chain deposition disease is characterized by deposition of monoclonal antibodies in the basement of membrane. Kidney is the most frequently involved organ. There was a male patient diagnosed as light and heavy chain deposition disease in department of Nephrology of the Second Xiangya Hospital, Central South University by renal biopsy. After treatment by oral prednisone, melphalan and thalidomide, the patient's proteinuria and serum creatinine decreased. The retrospective analysis of this case provides a guide for doctors to understand the light and heavy chain deposition disease. Early diagnosis and treatment could improve the prognosis.
Antibodies, Monoclonal ; adverse effects ; Basement Membrane ; physiopathology ; Biopsy ; Creatinine ; blood ; Heavy Chain Disease ; diagnosis ; drug therapy ; Humans ; Immunoglobulin Light Chains ; Kidney ; physiopathology ; Male ; Proteinuria

OBJECTIVETo investigate the Influence of risk factors that cause the phototoxic maculopathy by welding arc in occupational welders.

METHODSWe examined randomly a group of 86 male occupational welders 172 eyes from some local metal manufacturing enterprise from August 2010 to December 2013. The ophthalmologic examination which the participants underwent thorough including the best visual acuity, fundus examination by the supplementary lens, fundus photography, and the high definition optical coherence tomography (OCT) scan. All participants of this study underwent thorough the medicine examined by a specialist of occupational who prior to the OCT. All the subjects were divided into groups according to age, protection degrees , length of service, operating time . The incidences of phototoxic maculopathy were compared within groups. The subjects was divided randomly into the lutein group and the placebo group. The examination including the best visual acuity, serum lutein concentrations, macular pigmentoptical density (MPOD), Contrast and glare Sensitivity.

RESULTS(1) The total incidence of phototoxic maculopathy is 32.0%. (2) The incidences of phototoxic maculopathy in the strict protection group, the randomed protective group and the nonprofessional protection group were respectively 21.4%, 36.7%, 53.6%. The incidence in the strict protection group was lower than the other two groups, the incidence was the highest in the nonprofessional protection group, and the difference was statistically significant. (3) The longer length of service, and operating time , the more incidence of phototoxic maculopathy develop. (4) The lutein group prior to the placebo group at the best visual acuity, serum lutein concentrations, macular pigmentoptical density (MPOD), Contrast and glare Sensitivity.

CONCLUSIONThe risk factors of phototoxic maculopathy in male occupational welders are the length of service, operating time, protection degrees and the lutein assistantly. The incidence of phototoxic maculopathy occurs regardless of age.

Cross-Sectional Studies ; Humans ; Light ; adverse effects ; Lutein ; analysis ; Macula Lutea ; radiation effects ; Macular Pigment ; analysis ; Male ; Occupational Diseases ; epidemiology ; Occupational Exposure ; adverse effects ; Personal Protective Equipment ; Radiation Injuries ; Retinal Diseases ; Risk Factors ; Tomography, Optical Coherence ; Visual Acuity ; radiation effects ; Welding

Animals ; Cell Survival ; radiation effects ; Light ; adverse effects ; Mice ; Mice, Knockout ; Protein Tyrosine Phosphatase, Non-Receptor Type 1 ; antagonists & inhibitors ; metabolism ; Retinal Rod Photoreceptor Cells ; cytology ; enzymology ; radiation effects

BACKGROUNDMethanesulfonic acid sodium salt (Dipyrone), an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy.

METHODSOne hundred mice were assigned randomly into vehicle (V), methanesulfonic acid sodium salt (D), light damage model plus vehicle (MV) and light damage model plus methanesulfonic acid sodium salt (MD) groups (n = 25 each). In the MD group, methanesulfonic acid sodium salt (100 mg/kg) was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy (TEM) were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 mm from the optic nerve. Electroretinography (ERG) test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c (CytC) and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation.

RESULTSThe photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group (P < 0.05). TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 (Apaf-1), caspase 3, p53, p53-upregulated modulator of apoptosis (PUMA), Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-X(L) were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-X(L) decreased, whereas Bax immunoreactivity precipitated by Bcl-X(L) increased in the MD group compared to those in the MV group.

CONCLUSIONMethanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.

Animals ; Apoptosis ; drug effects ; radiation effects ; Blotting, Western ; Electroretinography ; Immunoprecipitation ; Light ; adverse effects ; Male ; Mesylates ; therapeutic use ; Mice ; Microscopy, Electron, Transmission ; Mitochondrial Proteins ; metabolism ; Random Allocation ; Retina ; drug effects ; radiation effects ; ultrastructure ; Tumor Suppressor Protein p53 ; metabolism

BACKGROUNDRetinal light injury can lead to degeneration of the photoreceptor cell layer. It has been hypothesized that the mechanism for this process is the photochemical damage. Ginkgo balboa extract (Ginkgo biloba extract EGB761) EGB761 is a free radical scavenger. The purpose of this study was to investigate the possible effect of orally administered EGB761 on retinal light damage of mouse photoreceptor cells.

METHODSKunming mice were randomly chosen for the following groups containing 20 animals in each: control group, light damage group, saline control group, and drug treatment group. The drug treatment group and saline control group were given daily gavage of EGB761 (150 mg×kg(-1)×d(-1)) one week before light exposure. At 7, 14, and 30 days after light exposure, animals were sacrificed and eyes were examined by light microscopy, electron microscopy, and retinal histopathology using in situ detection of apoptotic cells.

RESULTSIn the light damage group after 7 days there was visible edema, and the outer nuclear layer appeared withered with deeply stained dead cells, leaving only a thin nuclear layer of 7 - 8 cells. After 14 days, the photoreceptor cell layer disappeared, leaving only the outer nuclear layer of 1 - 3 cells with an average thickness of (37.988 ± 1.207) µm. The average thickness of the retina was (126.32 ± 2.31) µm. In the drug treatment group, the photoreceptor cell layer and outer nuclear layer damage were significantly lower than the saline group (t = 21.993, P < 0.001), demonstrating that EGB761, especially at 14 days after light exposure, can reduce retinal light damage in mice.

CONCLUSIONOral administration of EGB761 can partially inhibit apoptosis of photoreceptor cells, resulting in increased photoreceptor cell survival.

Animals ; Eye Injuries ; etiology ; prevention & control ; Light ; adverse effects ; Male ; Mice ; Microscopy, Electron ; Photoreceptor Cells ; drug effects ; radiation effects ; ultrastructure ; Plant Extracts ; therapeutic use ; Rats ; Retina ; drug effects ; radiation effects ; ultrastructure

Exposure to light can induce photoreceptor cell death and exacerbate retinal degeneration. In this study, mice with genetic knockout of several genes, including rhodopsin kinase (Rhok-/-), arrestin (Sag-/-), transducin (Gnat1-/-), c-Fos (c-Fos-/-) and arrestin/transducin (Sag-/-/Gnat1-/-), were examined. We measured the expression levels of thousands of genes in order to investigate their roles in phototransduction signaling in light-induced retinal degeneration using DNA microarray technology and then further explored the gene network using pathway analysis tools. Several cascades of gene components were induced or inhibited as a result of corresponding gene knockout under specific light conditions. Transducin deletion blocked the apoptotic signaling induced by exposure to low light conditions, and it did not require c-Fos/AP-1. Deletion of c-Fos blocked the apoptotic signaling induced by exposure to high intensity light. In the present study, we identified many gene transcripts that are essential for the initiation of light-induced rod degeneration and proposed several important networks that are involved in pro- and anti-apoptotic signaling. We also demonstrated the different cascades of gene components that participate in apoptotic signaling under specific light conditions.
Animals ; Apoptosis/radiation effects ; G-Protein-Coupled Receptor Kinase 1/genetics ; GTP-Binding Protein alpha Subunits/genetics ; *Gene Expression Profiling ; Genes, fos/genetics ; Light/adverse effects ; Light Signal Transduction/*genetics/physiology/radiation effects ; Mice ; Mice, Knockout ; Oligonucleotide Array Sequence Analysis ; Retina/metabolism/pathology/radiation effects ; Retinal Degeneration/etiology/*genetics/physiopathology ; Transducin/genetics

Photoaging is clinical character by dyspigmentations, telangiectacia, and wrinkles. Therefore, the assessment of therapeutic effects of photoaging depends on the management results of these three lesions. This article introduces the effect of laser and light-based therapies on photoaging.
Humans ; Low-Level Light Therapy ; Pigmentation Disorders ; radiotherapy ; Skin Aging ; radiation effects ; Telangiectasis ; radiotherapy ; Ultraviolet Rays ; adverse effects