Lasers in Medical Science

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Average VISIA pore counts from baseline through 2-month follow-up visit (2 M FU). N = 18. Tx, treatment. NAFL, 1565-nm non-ablative fractional laser; LPNY, long-pulsed 1064-nm Nd:YAG laser
Split-face comparison of pores of a 25-year-old woman at baseline and 2-month follow-up visit with the VISIA system, highlighting the pores available for counting. a LPNY-treated side at baseline. b NAFL-treated side at baseline. c LPNY-treated side at 2-month follow-up, pore number decreased by 28.9% compared to baseline. d NAFL-treated side at 2-month follow-up, pore number decreased by 43% compared to baseline. NAFL, 1565-nm non-ablative fractional laser; LPNY, long-pulsed 1064-nm Nd:YAG laser
Pores of a 36-year-old woman pretreatment and at a 2-month follow-up visit after five treatments with the VISIA system. a LPNY-treated side at baseline. b NAFL-treated side at baseline. c LPNY-treated side at 2-month follow-up. d NAFL-treated side at 2-month follow-up. Visible pores were reduced after both laser treatments. More apparent improvement of pores can be observed in NAFL-treated side. NAFL, 1565-nm non-ablative fractional laser; LPNY, long-pulsed 1064-nm Nd:YAG laser
Subjective assessments. Participants rated improvement in appearance of pores after each treatment (Tx) and at 2-month follow-up (2 M FU). N = 18. Avg, average; NAFL, 1565-nm non-ablative fractional laser; LPNY, long-pulsed 1064-nm Nd:YAG laser
Facial pores are visible openings of pilosebaceous follicles, and they are one of the major factors influencing facial skin appearance. This article aims to evaluate and compare the efficacy and safety of 1565-nm non-ablative fractional laser (NAFL) and long-pulsed 1064-nm Nd:YAG laser (LPNY) in treating enlarged facial pores. All subjects were treated with NAFL on their left faces and LPNY on their right. Five treatments were administered at 2-week intervals, with one follow-up session 2 months after the final treatment. Treatment efficacy was evaluated by subjective (pore improvement and subject satisfaction ratings) assessments and objective (pore number) assessments. At each appointment, any side effects or complications were recorded to evaluate the safety of the two lasers. A total of 18 individuals participated in this study. At the 2-month follow-up, NAFL and LPNY sides had significant reduction in pores (p < 0.0001 and p < 0.0001, respectively). However, there was no statistically significant difference in the mean number of pore reductions on either side (p > 0.05). There was no significant difference in pore improvement ratings and satisfaction ratings between the two sides (p > 0.05 and p > 0.05, respectively). Both lasers showed minimal side effects. Both lasers effectively treated enlarged facial pores and were well tolerated. The side effects of the 1064-nm LPNY were less severe than those of the 1565-nm NAFL. Identifier: NCT05360043.
Flow chart of eligible randomized controlled trials
Forest plot showing meta-analysis results for effect of LLLT on neck pain relief (vs. control)
Funnel plot of LLLT versus control by pain outcome
Forest plot showing meta-analysis results for effect of LLLT on pressure pain threshold relief (vs. control)
Low-level laser therapy (LLLT) is one of recent modalities for treatment of myofascial neck pain (MNP). Several RCTs have been conducted on its effectiveness. The aim of this comprehensive meta-analysis was to evaluate the effectiveness of LLLT on MNP. Electronic databases were searched for identifying eligible studies comparing the effectiveness of LLLT using any wavelength with placebo or active control in myofascial neck pain up to June 2022. Data related to pain intensity, pain pressure threshold (PPT), range of motion (ROM), and disability was analyzed as a pooled estimate of mean difference or standard mean difference (SMD) with 95% confidence intervals (CIs) using random/fixed-effect model. Funnel plot and Egger’s linear regression test were also conducted to examine the risk of publication bias. A total of 13 randomized controlled trials were included in this systematic review and meta-analysis. The data assessing laser effectiveness on different outcomes of 556 patients were considered for meta-analysis. Pooled results revealed that LLLT was significantly effective in pain reduction (MD = − 1.29, 95% CI = − 2.36; − 0.23, P < 0.001). Also, secondary outcomes including PPT (SMD of 2.63, 95% CI = 0.96; 4.30, P < 0.01) and right bending ROM (SMD of 3.44, 95% CI = 0.64; 6.24, P < 0.01) were improved, while disability (MD of − 7.83, 95% CI = − 17.1; 0.08, P = 1.34) did not improve significantly after LLLT. Our meta-data revealed that LLLT may reduce myofascial neck pain and its related outcomes. LLLT is suggested to be used by clinicians along with other therapies such as manual and exercise therapy.
The CBCT imaging of a peri-implantitis case showing bone loss around dental implant
The mean and standard deviations of all the clinical parameters and anaerobic bacteria counts at the baseline, treatment periods (2 weeks and 4 weeks), and follow-ups (3 months and 6 months). a Probing depth, b marginal bone loss, c bleeding on probing, d anaerobic culture. BL, baseline; 2 W, 2 weeks; 4 W, 4 weeks; 3 M, 3 months; 6 M, 6 months
The aims of this study were to identify the microbiological changes in the periodontal pockets following an Er:YAG laser (ERL) irradiation and mechanical debridement to compare the effectiveness of ERL irradiation to mechanical debridement for peri-implantitis treatment through randomized controlled trials. Twenty-three patients with peri-implantitis lesions were treated in either a test group, ERL set at energy level of 100 mJ/pulse, frequency of 10 Hz, pulse duration was 100 µs, and irradiated by three passages, or a control group, with mechanical debridement using an ultrasonic scaler. An examiner measured the following clinical parameters at different stages (a baseline and at 3- and 6-month post-treatment): probing depth (PD), bleeding on probing (BOP), marginal bone loss (MBL), and anaerobic bacteria counts. Linear regression, with generalized estimation equations, was used to compare the clinical parameters and anaerobic bacterial counts at different stages and between groups. The anaerobic bacterial counts significantly decreased within the control group during the follow-ups. At the 6-month follow-up, both groups showed a significant reduction in PD (test group: mean difference of 0.84 mm; control group: mean difference of 0.41 mm), and the test group showed a significantly higher PD reduction on the buccal site (1.31 mm) compared to that of the control group (0.25 mm). Both ERL and mechanical debridement treatments led to significant improvements in PD. When mechanical debridement therapy was used, significant anaerobic bacterial count reductions were observed. Future treatment of peri-implantitis should involve a combination of both of these therapies.
Steps in the preparation of the samples
Experimental design of the study considering the treatments
Schematic diagram of the laser ablation process
SEM image of dentin ablation by the Er,Cr:YSGG laser
Objective The study aimed to evaluate the bond strength of universal adhesives to dentin after Er,Cr:YSGG laser irradiation with nanosecond-domain and microsecond-domain pulses. Methods Eighty extracted caries-free, sound human molars were divided into eight groups. The enamel was removed until the dentin occlusal flat dentin surface was exposed. Etch-and-rinse followed by adhesive was applied to group 1, and a self-etch adhesive was applied to group 2. Er,Cr:YSGG laser (3 mJ, 100 Hz, 100 ns), (3 mJ, 100 Hz, 150 μs), and (20 mJ, 100 Hz, 150 μs) were applied to groups 3–4, 5–6, and 7–8, respectively. The laser preparation was followed by self-etch adhesives or adhesives treatment. When the composite resin had been built up on the samples, the shear bond strength was tested, and the data were statistically analyzed using analysis of variance (ANOVA). Results Groups prepared with nanosecond-pulse laser showed significantly higher bond strength values than the microsecond-pulse laser groups and self-etch mode group, and the SEM photographs also showed more dentinal tubules and no damage in the ablation area. The shear bond strength of long pulse laser ablated was comparable to that of self-etching system when it was combined with a self-etch adhesive at low energy, but higher energy laser degraded shear bond strength. Conclusions The pulse width of Er,Cr:YSGG laser affects the bond strength, nanosecond pulses of laser irradiation without water cooling can enhance bond strength, but microsecond pulses of laser cannot enhance bond strength.
The application points and as well as the dosages used
Illustration of the analysis of the visual analog scale to check the level of dissatisfaction with tinnitus in individuals with chronic tinnitus symptom. in functions of the intervention group
Illustration of the visual analog scale analysis to check the level of dissatisfaction with tinnitus in individuals with chronic tinnitus symptoms, depending on the session
Illustration of the analysis of the visual analog scale to check the level of dissatisfaction with tinnitus in individuals with chronic tinnitus symptoms, depending on the session and intervention group
To verify the effect of photobiomodulation therapy (PBMT) in individuals with chronic tinnitus without hearing loss, 20 patients who met the inclusion criteria were randomly divided into group 1: active low-level laser (LLL) and group 2: equipment without laser (placebo). Upon anamnesis, data collection, and audiological exams, the Tinnitus Handicap Inventory (THI) and the Visual-Analog Scale (EVA) were applied to measure the level of discomfort with tinnitus and the level of discomfort before and after laser treatment. The protocol used included 12 active LLL sessions for group 1 and not active for group 2, varying red and infrared wavelengths. There was a reduction in the disadvantage of individuals with tinnitus after the intervention and between the initial and final sessions, regardless of the intervention, although group 1 showed a greater reduction than group 2, regardless of point in time of assessment and number of session. There was no statistical difference as to group and point in time for the high-frequency audiometry and acuphenometry outcomes. Individuals with chronic tinnitus reduced the complaint, regardless of point in time and group of intervention; however, the group that received PBMT improved the level of satisfaction, regardless of point in time of assessment and number of session.
Push-out bond strength among evaluated groups
Proper bond strength of endodontic materials is an essential factor in the final success of root canal treatments, including perforation repairs. This study was designed to evaluate the effect of two power outputs of Nd:YAG laser (1064 nm) on push-out bond strength (PBS) of ProRoot mineral trioxide aggregate (MTA) and calcium-enriched mixture cement (CEM Cement) in the repair of artificial furcal perforations. This ex vivo study enrolled 66 extracted human molars. After preparing the access cavity, perforations were created on the floor of the pulp chamber with a diameter of 1.4 mm. The teeth were randomly distributed into the following six groups according to the repair material (MTA and CEM) and power output of laser irradiation (1 W and 1.5 W); A: MTA (case), B: CEM (case), C: Nd:YAG (1 W)/MTA, D: Nd:YAG (1 W)/CEM, E: Nd:YAG (1.5 W)/MTA, and F: Nd:YAG (1.5 W)/CEM. Then, a universal testing machine was utilized to assess the PBS. Data analysis was performed using ANOVA and T tests. Significant level was considered at P < 0.05. The highest mean ± SD of PBS was noted in Group Nd:YAG (1 W)/MTA (58.92 ± 36.13), followed by Nd:YAG (1.5 W)/MTA > Nd:YAG (1.5 W)/CEM > Nd:YAG (1 W)/CEM > MTA > and CEM. A significant difference was noted between laser and non-laser applications (P < 0.05). However, the increase of power output from 1 to 1.5 W had no significant influence on PBS (P > 0.05). The PBS of MTA groups was always significantly greater than that of CEM groups (P < 0.05). Although Nd:YAG laser irradiation positively influenced on PBS values in both material studied, increasing power output was not effective.
Systematic review flow diagram
Scarring is one of the most esthetically challenging and psychologically burdening aspects following inflammatory acne. While “macular” disease is the scar subtype with the least complicated outcome, its phase can be regarded as the most defining in the ultimate scar appearance. Moreover, with lasers recently gaining much popularity in the scientific community for managing several dermatologic conditions, we aimed to evaluate whether they would lead to significant benefits. For this systematic review, four databases consisting of PubMed, Scopus, Embase, and Web of Science were searched using a comprehensive string, with the data from the relevant yet eligible identified records qualitatively synthesized. After investigating the data obtained from the nine included studies, we found the utilized lasers, namely neodymium-doped yttrium aluminum garnet, fractional carbon dioxide, pulsed dye, erbium:glass, pro-yellow, and high-power optically pumped semiconductor, to be highly effective in managing the erythematous or dyspigmented appearance with the reduced elasticity also significantly improving. Moreover, the adverse events were both bearable and minimal, and transient. However, the degree of improvement each type of scar demonstrated following laser therapy varied based on the laser used. Neodymium-doped yttrium aluminum garnet, fractional carbon dioxide, and pulsed dye are the most commonly investigated lasers for managing macular acne scars, demonstrating eye-catching capabilities in managing either erythema or dyspigmentation. However, we still recommend that further comparative interventional studies be carried out, while the intended outcomes also assessed with objective measures for further clarification.
Although intense pulsed light (IPL) has been commonly used in the field of medical cosmetics in recent years, the exact outcomes of IPL in the treatment of inflammatory skin diseases remain unclear. To assess the clinical evidence for the use of IPL in the treatment of various inflammatory skin diseases and propose evidence-based recommendations, we searched for relevant publications in the PubMed and Web of Science databases and provided updated information. The inflammatory skin diseases treated with IPL consisted of acne vulgaris, rosacea, psoriasis, hidradenitis suppurativa (HS), atopic dermatitis (AD), Riehl’s melanosis, lupus erythematosus, cutaneous sarcoidosis, pilonidal cysts, and pigmented actinic lichen planus (PALP). The efficacy of IPL treatment for these inflammatory skin diseases was described and evaluated. Forty-two studies were included to provide this assessment. The evidence suggests that IPL can effectively and safely improve acne vulgaris and rosacea (recommendation grade B). For other described inflammatory skin diseases, IPL can be used as a tentative or supplementary treatment (recommendation grade C and D). The main complications include transitory erythema, edema, and pain, with the possibility of hyperpigmentation, blisters, and a burning sensation in some individuals.
Discomfort and dull pain are known side effects of orthodontic treatment. Pain is expected to be reduced by near-infrared (NIR) lasers; however, the mechanism underlying effects of short-pulse NIR lasers in the oral and maxillofacial area remains unclear. This study aimed to examine the effects of high-frequency NIR diode laser irradiation on pain during experimental tooth movement (ETM) on 120 J. NIR laser with 910 nm wavelength, 45 W maximum output power, 300 mW average output power, and 200 ns pulse width (Lumix 2; (Lumix 2; Fisioline, Verduno CN, Italy) was used for the experiment. A nickel–titanium-closed coil was used to apply a 50-gf force between the maxillary left-side first molar and incisor in 7-week-old Sprague–Dawley rats (280–300 g) to induce ETM. We measured facial-grooming frequency and vacuous chewing movement (VCM) period between laser-irradiation and ETM groups. We performed immunofluorescent histochemistry analysis to quantify levels of Iba-1, astrocytes, and c-fos protein-like immunoreactivity (Fos-IR) in the trigeminal spinal nucleus caudalis (Vc). Compared with the ETM group, the laser irradiation group had significantly decreased facial-grooming frequency (P = 0.0036), VCM period (P = 0.043), Fos-IR (P = 0.0028), Iba-1 levels (P = 0.0069), and glial fibrillary acidic protein (GFAP) levels (P = 0.0071). High-frequency NIR diode laser irradiation appears to have significant analgesic effects on ETM-induced pain, which involve inhibiting neuronal activity, microglia, and astrocytes, and it inhibits c-fos, Iba-1, and GFAP expression, reducing ETM-induced pain in rats. High-frequency NIR diode laser application could be applied to reduce pain during orthodontic tooth movement.
Illustration of the three experimental groups in experiment 1. Control indicated no laser treatment
Illustration of the 2-lap laser irradiation in group E: a first lap and b second lap
Effect of the Er,Cr:YSGG laser on growth of A. actinomycetemcomitans (a–c) and P. gingivalis (d–f) on agar plates. Growth inhibition zones were observed at 3 different irradiation durations; 30 s (a, d), 60 s (b, e), and 90 s (c, f)
Log CFU/ml of A. actinomycetemcomitans following laser irradiation. Group A: no irradiation, B: 12 s × 1 lap, C: 24 s × 1 lap, D: 48 s × 1 lap, E: 24 s × 2 laps
Log CFU/ml of P. gingivalis following laser irradiation. Group A: no irradiation, B: 12 s × 1 lap, C: 24 s × 1 lap, D: 48 s × 1 lap, E: 24 s × 2 laps
In vitro bacterial elimination using the erbium, chromium: yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser against periodontopathic bacteria was investigated. Bacterial suspensions of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were spread on agar plates and the Er,Cr:YSGG laser was applied at 40 mJ pulse energy for durations of 30 s, 60 s, and 90 s. The agar plates were incubated, and growth inhibition zones were assessed. Optimal laser irradiation durations to achieve maximal bacterial elimination were evaluated using laser ablation on the bacterial colonies. The remaining viable bacteria were determined by the colony-forming unit (CFU) counting method. Growth inhibition zones were observed at all irradiation durations for both A. actinomycetemcomitans and P. gingivalis. Mean logarithmic values of CFU/ml after bacterial colony irradiation for 0 s (control), 12 s × 1 lap, 24 s × 1 lap, 48 s × 1 lap, and 24 s × 2 laps were 8.82 ± 0.35, 7.31 ± 0.94, 6.32 ± 0.61, 3.17 ± 2.90, and 0.00, respectively, for A. actinomycetemcomitans and 9.83 ± 0.50, 9.42 ± 0.11, 6.90 ± 1.60, 2.33 ± 3.19, and 0.00 for P. gingivalis. Significant differences were found between the control group and the two irradiated groups 48 s × 1 lap and 24 s × 2 laps (p < 0.05), and also between irradiated groups 12 s × 1 lap and 24 s × 2 laps (p < 0.05). An Er,Cr:YSGG laser with power setting 1.5 W and 30 Hz frequency showed potential for bacterial elimination against A. actinomycetemcomitans and P. gingivalis in vitro. Significant bacterial elimination (> 99.99%) was observed after 48 s of irradiation.
Tattoos have become ingrained in our society and have served varied purposes throughout human civilization. So long as tattoos have existed, there has been demand for their removal. Lasers are currently the modality of choice in the removal of tattoos, as they are more efficacious than previously used methods. The most common lasers are the 532 nm and 1064 nm neodymium-doped yttrium aluminum garnet lasers, the quality-switched 694 nm Ruby laser, and the quality-switched 755 nm alexandrite laser. However, picosecond lasers are rapidly gaining favor in tattoo removal. An in-depth understanding of laser principles and how they can be applied in the setting of tattoo removal is key. Also, a greater understanding of the origin of and colors within a tattoo, the presence of tattoo layering, and a patient’s Fitzpatrick skin type increase the odds of satisfactory results. This review provides dermatologists with a comprehensive summary on laser fundamentals, an overview on treatment principles, and recent developments in the field of laser tattoo removal.
Flow diagram of the literature search and included studies
Quality assessment of the included studies
To evaluate and synthesize the evidence from the individual reviews that evaluated the efficacy of PDT therapy in root canal disinfection by undertaking an umbrella review. The protocol of the review was registered in the PROSPERO database under number CRD42021214056. The literature search was conducted using the following electronic databases: PubMed, Scopus, Web of Science, BVS, Cochrane Database of Systematic Reviews, Embase, and Epistemonikos, from inception to July 2021. Systematic reviews that evaluated the efficacy of PDT for root canal disinfection were included. Two authors independently performed a literature search, data extraction, and quality assessment of the included studies. Any disagreements were resolved by a third reviewer. The quality of the reviews was assessed using the AMSTAR 2 tool and the final categorization of each systematic reviews was classified as of “high,” “moderate,” “low,” or “critically low” quality. Six systematic reviews were included in the current umbrella review and all of them were graded as critically low quality. From the critically low-quality evidence available, this umbrella review showed that the efficacy of PDT in root canal disinfection remains yet undetermined.
Flow diagram of included studies
Bias risk assessment of included studies
Forest plot for complete cure rate
Forest plot for mycological cure rate
Forest plot for clinical effective rate (a). Sensitivity analysis was not performed (b). After excluding one RCT by Rajbanshi et al., a sensitivity analysis was performed
Introduction Onychomycosis is a common fungal infection of the nail. Laser and topical antifungal agent combination therapy is an emerging treatment for onychomycosis. The objective of this study was to systematically evaluate the efficacy and safety of laser and topical antifungal agent combination therapy for onychomycosis. Methods The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP databases were searched from inception to November 2021. Randomised controlled trials (RCTs) on laser therapy combined with topical antifungal agents for onychomycosis were included. The Cochrane Collaboration tool was used to assess the risk of bias, and Revman 5.3 software was used in the meta-analysis. Results Twelve studies involving 869 patients were included in this meta-analysis. The results showed that compared with topical antifungal agents alone, laser and topical antifungal agent combination therapy was superior in terms of the complete cure rate (RR 6.04,95% CI (2.17, 16.85), P = 0.0006), mycological cure rate (RR 1.27, 95% CI (1.10, 1.48), P = 0.001), clinical effective rate (RR 1.38, 95% CI (1.20, 1.57), P < 0.00001) and patient satisfaction rate (RR 1.47,95% CI (1.17, 1.84), P = 0.0009).The subgroup analysis of outcome indicators, including mycological cure rate and clinical effective rate, demonstrated that both carbon dioxide (CO2) laser therapy combined with topical antifungal therapy and 1064-nm neodymium-doped:yttrium aluminium garnet (Nd:YAG) laser therapy combined with topical antifungal therapy showed better results than topical antifungal therapy alone. No adverse events were identified except for three studies reporting transient burning sensation without treatment and mild to moderate pain, both of which were well tolerated. Conclusion The present study indicated that laser and topical antifungal agent combination therapy is effective for onychomycosis. However, more large-scale and well-designed RCTs are warranted.
The aim of this study was to evaluate the participation of nitric oxide (NO) in the hypotensive and vasorelaxation effect induced by PBM using an aluminum gallium arsenide (AlGaAs) diode laser (660 nm). Male Wistar rats were treated with the inhibitor of nitric oxide synthase (l-NAME). A red laser (660 nm; 63 J/cm²; 56 s/point) was applied to the abdominal region at six different points. Thoracic aorta was dissected for vascular reactivity study, and a laser (660 nm; 96 J/cm²; 56 s) was applied after incubation with the NO donor DETA-NO, PBS, or hydroxicobalamin. Endothelial cells (HUVEC) were treated with DETA-NO or CuSO4, and then, PBM (63 J/cm²) was applied, and the nitric oxide was detected. Hypertensive l-NAME rats did not exhibit a decrease in blood pressure after PBM. PBM promoted vasodilation in the aorta isolated from normotensive rats, and less effect in the aorta of l-NAME rats and the addition of the NO donor, DETA-NO, promoted greater vasodilation by PBM in the aorta of l-NAME rats. In endothelial cells, an increase in NO, after PBM, was detected; however, with the addition of CuSO4, which catalyzes the decomposition of NO storage, there was no detection of NO after PBM. The results of this study demonstrate that the hypotensive and vasodilatory effect of PBM with a red laser at 660 nm is modulated by the release of nitric oxide from the storage.
Forest plot for the event “clinical attachment level” (CAL) (reported in mm) treated with SRP vs Nd:YAG + Er:YAG combination laser therapy
Forest plot for the event reduction in “probing depth” (PD) (reported in mm) treated with SRP vs Nd:YAG + Er:YAG combination laser therapy
Forest plot for the event reduction in “recession coverage” (REC) (reported in mm) treated with SRP vs Nd:YAG + Er:YAG combination laser therapy
Assessments of the risk of bias of randomized clinical trials
Lasers are increasingly utilized in the non-surgical treatment of periodontal disease. The aim of the present systematic review with meta-analysis was to investigate the combination use of Nd:YAG and Er:YAG laser therapy in the treatment of severe periodontitis. A systematic review of the literature including searches in PubMed/Medline, Cochrane Library, Google Scholar, and Grey Literature databases, as well as manual searches, was performed until November 1, 2021. Only studies a combination of lasers during non-surgical treatment of pockets ≥ 6mm were included. The eligibility criteria for meta-analysis comprised randomized controlled trials (RCTs) comparing the use of combination laser therapy with/without adjunctive mechanical for the non-surgical management of periodontitis. From 57 initial articles, 6 full-text articles were assessed for eligibility. Two studies were excluded, one study was not a randomized clinical trial (case series), and one study was an in vitro study. Four RCTs were included in the meta-analysis. It was shown that combination of Nd:YAG and Er:YAG may be beneficial for non-surgical periodontal therapy with an additional average reduction in pocket depth and clinical attachment level reported at 1.01 and 0.77 mm respectively when compared to controls. The findings suggest that the combination of Nd:YAG and Er:YAG lasers may lead to additional clinical improvements compared to nonsurgical treatment alone. Future research is needed to substantiate these findings and optimize clinical guidelines including more specific laser protocols. Preliminary data suggest favorable outcomes following the combination of Nd:YAG and Er:YAG lasers for non-surgical periodontal therapy.
Our aim was to evaluate the long-term results of micropulse laser trabeculoplasty (MLT) with 577-nm yellow wavelength in the treatment of glaucoma. We reviewed the medical records of 51 patients (51 eyes) with uncontrolled primary open-angle glaucoma or pseudoexfoliation glaucoma who underwent 180° MLT for the first time. The success of MLT was defined as an IOP reduction of ≥ 20% and IOP < 21 mmHg after treatment. If the number of medications was increased or further laser trabeculoplasty or glaucoma surgery was required after treatment, the case was considered unsuccessful. The mean duration of patient follow-up was 18.39 ± 12.17 months (range 3–52 months). Patients included in the study used 2–4 types of antiglaucoma eye drops (mean 3.43 ± 0.7). The mean number of MLT spots was 65.54 ± 6.19, and the mean energy level was 750.98 ± 101.73 mJ. The decrease in intraocular pressure compared to baseline measurements was: 16.72 ± 11.87%, 15.07 ± 13.76%, 12.63 ± 14.29%, 16.66 ± 19.32%, and 16.75 ± 19.78% during follow-up at 3, 6, 12, 24, and 36–48 months. Successful response was achieved in 35.41%, 36.95%, 34.21%, 40%, 41.17%, and 42.85% of patients during 3, 6, 12, 18, 24, and 36–48 months of follow-ups, respectively. Of the 51 eyes studied, 12 patients (23.5%) underwent post-MLT glaucoma surgery, and 7 patients (13.7%) had cataract surgery, whose follow-up data were subsequently censored. The reduction of intraocular pressure showed a significant correlation with baseline intraocular pressure, while age and laser power showed no correlation (p > 0.05). MLT is a novel treatment option for patients with glaucoma with favorable long-term outcomes and a good safety profile.
Optical coherence tomography (OCT) is a noninvasive, radiation-free, and high-resolution imaging technology. The intraoperative classification of normal and cancerous tissue is critical for surgeons to guide surgical operations. Accurate classification of gastric cancerous OCT images is beneficial to improve the effect of surgical treatment based on the deep learning method. The OCT system was used to collect images of cancerous tissues removed from patients. An intelligent classification method of gastric cancerous tissues based on the residual network is proposed in this study and optimized with the ResNet18 model. Four residual blocks are used to reset the model structure of ResNet18 and reduce the number of network layers to identify cancerous tissues. The model performance of different residual networks is evaluated by accuracy, precision, recall, specificity, F1 value, ROC curve, and model parameters. The classification accuracies of the proposed method and ResNet18 both reach 99.90%. Also, the model parameters of the proposed method are 44% of ResNet18, which occupies fewer system resources and is more efficient. In this study, the proposed deep learning method was used to automatically recognize OCT images of gastric cancerous tissue. This artificial intelligence method could help promote the clinical application of gastric cancerous tissue classification in the future.
Arrangement of visible (black circles) and infrared lasers (white circles) on helmet (A). The helmet with illuminated lasers (B) and a patient wearing the helmet (C)
Consort flowchart of the study profile
The PANSS score test changes over the 2-month period in chronic patients with schizophrenia comparing the sham-controlled group and the laser-treated group
The MMSE score test changes over the 2-month period in chronic patients with schizophrenia comparing the sham-controlled group and the laser-treated group
Low-level laser therapy (LLLT) is a noninvasive technique used in different medical fields. It has been applied in different medical areas such as wound healing, traumatic brain injuries, neurological disorders, cognitive disorders, Alzheimer’s disease, pain, and arthritis, with different results. We studied the effectiveness of LLLT on cognitive impairment in patients with chronic schizophrenia. A randomized controlled double-blind clinical trial was performed in a men’s chronic treatment center, in Razi Psychiatric Hospital, in Tehran, Iran. We screened the cognitive impairment by Mini-Mental State Examination (MMSE). Positive And Negative Syndrome Scale (PANSS) was also used to assess the patients’ positive and negative symptoms. Seventeen consenting patients were randomly allocated to the treatment arm, and 15 to the sham treatment control arm. The mean age of the control and treated patients was 49.47 ± 6.99 and 50.24 ± 7.69, respectively. No significant difference in PANSS and MMSE test scores was detected in both groups after the 6th session and after 2 months of follow-up after laser therapy. The positive and negative scales and agitation and excitement levels did not change significantly in either group. Nevertheless, the depression/anxiety subscale in the PANSS test showed a significant reduction after 6 sessions but did not persist after 2 months. No improvement in cognitive impairment or the positive and negative symptoms was detected after LLLT in patients with chronic schizophrenia. Trial registration: IRCT 20210520051349N1.
Top view of the experimental apparatus geometry (left) and a reflectance profile with its derivative and associated critical point (right)
Interindividual evolution of the complex refractive index with wavelength for breast tissue of the indicated type. Points indicate the average value and error bars the standard error of the respective real (left) and imaginary (right) component across all patients with the indicated diagnosis. Cauchy fits according to (6) with the optimal coefficients of Table 1 are also plotted for each diagnosis
Photon mean free paths according to (7) for three types of breast tissue and the average imaginary index values of Fig. 2. Lines are least square fits with optimal parameters given in Table 3
Real index contrast between breast tissues with the indicated diagnoses. Error bars indicate the propagated standard error
Real index contrast at the indicated wavelengths as laid out in Table 4. Patients A1 through A3 suffer from fibroadenoma and patients C1 through C5 suffer from cancer. Error bars indicate the propagated standard error of real index measurements
We report differences in the refractive index of healthy and tumorous freshly excised human breast tissue as determined from reflectance profile measurements at five wavelengths (432 nm, 532 nm, 633 nm, 964 nm, 1551 nm) in the visible and near-infrared using a standard prism-coupling refractometer. These refractive index differences, particularly in the near-infrared, can be used to distinguish fibroadenomas and cancerous growths not only from normal breast tissue but also from each other.
Laser has been considered to show many favorable characteristics, including wound healing acceleration, hemostasis, biostimulation, and microbial inhibition. Previous studies have investigated the effect of laser treatment during the process of wound healing, with conflicting results. To date, there is still no unified conclusion on the effect and application principle of clinical laser therapy. This study evaluated the incision morphology, wound healing speed, and histological changes in mice oral mucosal wounds excised with diode laser, Er:YAG laser, and cold scalpel. The results showed that compared with the cold scalpel group, laser treatments caused more tissue thermal damage and carbonization, which led to a healing delay. However, lasers also showed some advantages, including hemostasis, regular incision, and immune response mobilization, suggesting that lasers may be beneficial in some specific cases, such as reducing intraoperative accidents and wound tissue laceration and controlling bleeding and postoperative infection. This study provides a theoretical basis for clarifying the effect of laser treatments and their clinical application principle.
Schematic representation of the experimental process
Trend chart of the push-out bond strengths of fiber posts in each group
SEM images of the bonding interface in the coronal, middle, and apical regions of the roots in groups A, B and C (× 2000) (P, fiber post; RT, resin tags; D, root dentine)
The objective of this study was to evaluate the effect of Er:YAG laser irrigation on the push-out bond strength of fiber posts to the root dentine. Sixty extracted human mandibular first premolars were collected and decoronated. The residual roots received endodontic treatment. The treated roots were randomly divided into three groups according to different irrigation protocols: group LAI (Er:YAG laser–activated irrigation), group PUI (passive ultrasonic irrigation, positive control), and group CSI (conventional syringe irrigation, negative control) ( n = 20). Each group was divided into two subgroups, either total-etching modes or self-etching modes ( n = 10). After fiber post restoration, all roots were sectioned into seven 1.0-mm-thick slices. The slices received a push-out test by a universal test machine. The resin tag on the segments’ bonding interfaces was observed by scanning electron microscope. There were significant differences in the effects of the irrigation method, bonding modes, and root regions on the push-out bond strength among the groups ( p < 0.05). The specimens with Er:YAG laser–activated irrigation and self-etching mode showed significantly the highest bonding strength ( p < 0.001). The lengths and densities of resin tags in group PUI or group LAI with self-etching modes were longer than those in group CSI with total-etching modes. The laser-activated irrigation with self-etching modes improved the bond strength of fiber post to root dentine compared to the passive ultrasonic irrigation or conventional syringe irrigation with total or self-etching modes.
Cell viability and cell cycle distribution assessment. a CAL-27 cells were treated with different concentrations of HMME at 0–16 μg/ml, different intensities of laser at 0–2.4 J/cm², and HMME plus laser. Cell viability was determined by the CCK-8 assay. *P < 0.05 vs. control, and **P < 0.01 vs. control. b Histogram represents the percentage of cells arrested in different phases of the cell cycle. *P < 0.05 vs. control. c The percentages of cell cycle distribution in different groups (HMME: 2.5 μg/ml; laser: 1.8 J/cm²) were analyzed using flow cytometry. Data are means ± SD of three independent experiments
The target miRNA of HMME-PDT. a Venn diagram indicated intersection of differentially expressed miRNAs (DEMs) in the two datasets GES28100, and GES137865. b miR-21 and miR-155 expressions in normal and OSCC tissues based on the TCGA database. *P < 0.05 vs. normal, and **P < 0.01 vs. normal. The expression levels of miR-21(c) and miR-155 (d) in different groups (HMME, 2.5 μg/ml; laser, 1.8 J/cm²) were analyzed by real-time PCR. The expressions of miR-21and miR-155 were normalized to U6 snRNA. **P < 0.01 vs. control. Data are means ± SD of three independent experiments
Prediction of miR-21 target genes. a Pearson correlation analysis demonstrated that the expressions of target genes (PDCD4, RECK, and SPRY2) and miR-498 were markedly negatively correlated in OSCC tissues. b The expressions of PDCD4, RECK, and SPRY2 in normal and OSCC tissues based on the TCGA database. **P < 0.01 vs. normal, and ***P < 0.001 vs. normal
Expression levels of P53, PDCD4, RECK, and SPRY2 after different treatments (HMME: 2.5 μg/ml; laser: 1.8 J/cm²). a P53, PDCD4, RECK, and SPRY2 protein expressions were upregulated in the HMME-PDT group (HMME: 2.5 μg/ml; laser: 1.8 J/cm²). β-actin served as the loading control. b Histogram represents the percentages of relative protein expressions in different treatment groups. **P < 0.01 vs. control. Data are means ± SD of three independent experiments
HMME-PDT (HMME, 2.5 μg/ml; laser, 1.8 J/cm²) regulated the expressions of miR-21 and target genes (PDCD4, RECK, and SPRY2) via ¹O2. a The levels of intracellular ¹O2 induced by HMME-PDT. The cells were labeled with SOSG and observed by fluorescence microscopy (magnification × 400). Green fluorescence indicates the level of intracellular ¹O2. b The expression levels of miR-21 were determined by real-time PCR in CAL-27 cells. The expression of miR-21 was normalized to U6 snRNA. **P < 0.01 between groups. c Representative expression of miR-21 target genes with and without histidine (10 mM) in CAL-27 cells. β-actin served as the loading control. d Histogram represents the percentages of relative protein expression in different treatment groups. **P < 0.01 between groups. Data are means ± SD of three independent experiments
The objective of this study was to determine the mechanism and effect of hematoporphyrin monomethyl ether mediated photodynamic therapy (HMME-PDT) on oral squamous cell carcinoma (OSCC). Human OSCC CAL-27 cells were randomly divided into four groups: control group, HMME group, laser group, and HMME-PDT group. Cell viability was detected by the CCK-8 method. Cell cycle distribution was evaluated by flow cytometry. GEO database was used to screen differentially expressed microRNAs (DEMs), and TCGA database was performed to verify DEM expression in OSCC and normal tissues. The effects of HMME-PDT on DEM expression were assayed by real-time PCR, and the expressions of miRNAs target genes were measured by western blot. Fluorescence probes were used to determine the production of singlet oxygen (¹O2). Compared with the other three groups, HMME-PDT dramatically inhibited CAL-27 cell proliferation and induced G0/G1 cycle arrest. The expressions of miR-21 and miR-155 were significantly upregulated in OSCC. HMME-PDT downregulated the expression of miR-21 but had no obvious effect on miR-155. HMME-PDT remarkably upregulated the levels of P53 and miR-21 target proteins, such as PDCD4, RECK, and SPRY2. ¹O2 was generated during HMME-PDT, and inhibition of ¹O2 production could reverse the regulation of HMME-PDT on P53, miR-21, and its target proteins, thus restoring cell viability. HMME-PDT can significantly inhibit the growth of OSCC cells, and the mechanism of this effect is related to the regulation of the P53-miR-21-PDCD4 axis via ¹O2 induced by HMME-PDT.
aTrilogy linear accelerator (RapidArc) (Varian, USA). b Positioning of animals for the radiotherapy protocol
Micro-CT examination. a Skyscan 1172 microtomograph (Skyscan Kontich, Belgium) with positioned hemimandible. b Close-up view of the hemimandibles positioned for micro-CT image acquisition
a Micro-CT image of the interradicular portion of the lower second molar. b Demarcation of the area containing only trabecular bone (red circle). c Region of interest (ROI) selected for trabecular bone microarchitecture analysis
Interradicular portion of mandibular second molar and area for analysis of the percentage proportion of trabecular area in each group. a ROI control group. b ROI radiotherapy group. c Immediate laser group ROI. d ROI late laser group
To investigate whether low-level laser therapy (LLLT), at different times of application (immediate and late) in the region of the parotid glands, has a distance effect on the microarchitecture of the trabecular bone in mandible of rats irradiated by volumetric modular arc therapy (VMAT). Thirty adult Wistar rats were randomly divided into placebo control groups (CG, n = 2), only radiotherapy (RG, n = 2), only LPLT (LG, n = 2), and two other groups using LLLT in the immediate time (24 h) (ILG, n = 12) and late (120 h) (LLG, n = 12) to radiotherapy by VMAT in a single dose of 12 Gy. LLLT with AsGaAl laser (660 nm, 100 mW), a spot size of 0.0028 cm2, was applied in three points in the region of the right parotid gland, with energy of 2 J/cm2, 20 s per point, for 10 consecutive days. After euthanasia, the right hemimandibles of each animal were dissected, prepared, and analyzed by computerized microtomography (micro-CT) and histomorphometry. The different groups were analyzed by the Tukey and Bonferroni multiple comparison tests. The micro-CT analysis found statistically significant differences between the groups, especially in the LLG, which had the highest average bone volume compared to the CG (p = 0.001) and ILG (p = 0.002) and a greater number of trabeculae than the CG (p = 0.000) and ILG (p = 0.031). The ILG also had a higher number of trabeculae than the CG (p = 0.005). Trabecula separation (Tb.Sp) was lower in the LLG (p = 0.000) and ILG (p = 0.002) when compared to the CG. In the histomorphometry, there was no statistical difference between the groups in relation to all the analyzed variables. Micro-CT analysis showed that the LLLT, even applied at a distance, both in the immediate and late VMAT times, has an effect on the mandibular bone microarchitecture by increasing the volume and number of trabeculae and decreasing the spaces between them.
Schematic representation of study design
Failure types for each group in percentages
SEM representative micrograph images showing surfaces ti-bases subjected to different debonding procedures and the surface of control group with no debonding procedure (original magnification × 1000)
Representative micrograph images of fractured surfaces at × 50 magnification. O, origin of fracture; H, hackle lines; AL, arrest lines; CC, compression curl
To evaluate the efficacy of Er,Cr:YSGG laser irradiation on the removal of zirconia hybrid abutment crowns (HAC) from ti-bases and investigate the effects of laser output power and zirconia generation on debonding time and fracture resistance of crowns. A hundred monolithic zirconia HACs were fabricated by using 4Y-TZP and 5Y-TZP materials and subsequently cemented onto the ti-bases with a resin luting agent. Each zirconia group was further divided into 5 subgroups according to the debonding procedure as control (no debonding), 4.5 W-, 5 W-, and 6 W-laser irradiation, heat processed (n = 10). Er,Cr:YSGG laser (Waterlase MD; Biolase Technology Inc., Irvine, CA) was used on a noncontact hard tissue mode at a 20-Hz repetition rate and 140-μs pulse duration with 50% water and 50% air. Debonding durations were recorded for each specimen, and modes of failure were investigated. Crowns were re-cemented on their corresponding ti-bases, and HACs were subjected to fracture strength test. Debonding duration and fracture strength data were statistically analyzed. Fractured zirconia crown surfaces of ti-bases were examined under the scanning electron microscope. 5Y-TZP crowns were debonded from ti-bases in significantly lower durations in comparison with 4Y-TZP crowns for all output powers [4.5 W (P = 0.001), 5 W (P = 0.002), and 6 W (P = 0.0014)]. For both 4Y-TZP and 5Y-TZP materials, debonding duration was significantly decreased with the increase in laser output power (P ≤ 0.001 for 4Y- and 5Y-TZP). In comparison with 4Y-TZP heat-processed group to the 4Y-TZP laser-irradiated groups, no significant differences were detected in terms of fracture strength (P > 0.05), while heat-processed crowns exhibited significantly lower fracture strength values than those of control group (P = 0.006). All debonding procedures significantly reduced fracture strength values of 5Y-TZP crowns in comparison with the control group (P ≤ 0.001). The common failure type was the adhesive failure between the zirconia crown and resin cement for all groups. SEM evaluation showed no visible damage caused by laser irradiation or heat application. The use of Er,Cr:YSGG laser irradiation is an efficient way to retrieve zirconia crowns from ti-bases. The higher the output power of the laser, the shorter the bonding procedure. The debonding duration and fracture strength of the crown were affected by the zirconia generation. Debonded 5Y-TZP zirconia crowns should not be reused due to the decrease in mechanical strength values.
Infrared thermography of thighs of a man (left) and a woman (right) as representative image of male and female patterns for cellulite. Five men were evaluated as negative controls for thermographic images
Frequency histogram of standard deviation intervals calculated from a sample size of 60 thighs. Each thigh presented 30 points of affeered temperatures by infrared thermography. Eight equal intervals were generated and frequency distribution is represented
Linear regression and correlation of standard deviation of thigh temperatures × visual cellulite grade. N = 60 thighs; correlations with Spearman r were considered significant
Linear regression and correlation of visual cellulite grade with skin phototype. Standard deviation of thigh temperatures × visual cellulite grade. N = 60 thighs; correlations with Spearman r was considered significant
Cellulite is a morphological alteration of the tegument tissue, directly interfering in self-esteem with etiology and pathophysiology far from being a consensus. Although the visual diagnosis of cellulitis is well known, it does not represent the real pathological condition of the subcutaneous tissue. The aim of the study was to investigate the hypothesis that the more heterogeneous tissue pattern analyzed by infrared thermography, the more severe is the cellulite grade. Forty female participants were selected and 60 thighs were analyzed by clinical anamnesis and infrared thermography. Classical visual analysis was correlated to the tissue heterogeneity measured by thermography. R Spearman’s correlation between visual evaluation and thermography was 0.92. Phototype presented a negative significant correlation of 0.67 with classical visual analysis. In the present study, we presented a simple method based on infrared thermography that can be adopted in any esthetics office with a correlation of 0.92 with the visual classic evaluation, but, besides, may be very helpful to the clinician to decide which treatment will be adopted, i.e., an aggressive and inflammatory approach such as the radiofrequency of shockwave therapy or an anti-inflammatory approach such as photobiomodulation, depending on the inflammatory status of cellulite.
The aim of the present study was to analyze the effects of light-emitting diode therapy (LEDT) on cardiovascular effort during a single bout of high-intensity interval training (HIIT) and on blood pressure (BP), salivary nitrite, and heart rate variability (HRV) responses after the exercise session in postmenopausal women. Sixteen postmenopausal women between 50 and 70 years of age participated in the present study. The intervention comprised two sessions: placebo plus HIIT and LEDT plus HIIT, with a 14-day interval between sessions. The oxygen uptake (VO2), heart rate (HR), and rating of perceived exertion (RPE) were monitored throughout the HIIT sessions. Salivary samples were taken before, immediately post, and 30’ and 60’ post-HIIT sessions for nitric oxide (NO) analysis. In addition, HR and BP were checked before, 15 min, 30 min, 45 min, and 60 min post-HIIT sessions. HR data were used to calculate the HRV indices. Cardiovascular parameters during HIIT and BP, HRV, and NO responses were not different between placebo and LEDT conditions (p > 0.05). BP responses increased after compared to pre-exercise (p < 0.01). HRV was impaired post- compared to pre-exercise (p < 0.05). LEDT did not improve physiological performance during HIIT and did not accelerate the recovery of BP and autonomic modulation or change the NO release after exercise in postmenopausal women.
Pre-treatment (A) and post-treatment (B) photographs of a 19-y-old male patient. Pre-treatment ECCA score was 113.33, and post-treatment ECCA score was 66.67
Pre-treatment (A) and post-treatment (B) photographs of a 23-y-old male patient. Pre-treatment ECCA score was 116.67, and post-treatment ECCA score was 73.33
Pre-treatment (A) and post-treatment (B) photographs of a 22-y-old male patient. About 1 month after treatment, cord scars appeared on the face
Ablative fractional laser treatment has been extensively used for resurfacing atrophic acne scars. However, few studies have investigated how the parameters set during laser procedures affect efficacy. In this retrospective study, we examined the relationship between efficacy and Fitzpatrick skin type, gender, age, follow-up duration, energy, and treatment sessions utilizing ablative fractional carbon dioxide (CO2) laser in Asians with Fitzpatrick skin types III–IV. We then analyzed the relationship between outcome and adverse effects including hyperpigmentation. Three blinded dermatologists used the ECCA (Echelle d’Evaluation Clinique des Cicatrices d’Acnluation Clinique des Cicospectively review 82 of 1034 patients who presented at our institution for atrophic acne scar treatment between August 2013 and August 2019. Factors associated with efficacy, including age, gender, Fitzpatrick skin type, energy, treatment sessions, follow-up duration, and pigmentation, were analyzed. 82 patients met inclusion criteria. Patients underwent one to three CO2 laser treatment sessions. Parameter settings for individual patients were consistent across treatments. Mean ECCA scores decreased from 102.70 ± 24.95 to 87.28 ± 24.48 (p ≤ 0.001). The number of treatment sessions and duration of pigmentation lasting shorter than 3 months positively correlated with better outcomes. All patients had erythema, which lasted longer than 3 months in 16 patients (19.51%). Post-inflammatory hyperpigmentation (PIH) affected 60 patients (73.17%) and lasted longer than 3 months in 26 patients (31.71%). One patient experienced hypopigmentation (1.22%), while 8 experienced acne flare-up (9.76%). Post-laser scars occurred in 2 patients (2.44%). Our data suggest that in atrophic acne scar treatment in Asians using fractional CO2 laser, 3 treatment sessions and duration of hyperpigmentation within 3 months have better outcomes regardless of energy, gender, age, Fitzpatrick skin type, follow-up duration, and disease course.
Changes of uncorrected distance visual acuity (UDVA) after SMILE surgery with different cap thickness. * Repeated measures test
To compare visual and refractive outcomes as well as changes in high-order aberrations in patients with 120- versus 140-µm cap thicknesses 12 months after small incision lenticule extraction. Ninety-four patients were randomized to receive small incision lenticule extraction with either a 120-µm cap thickness (n = 47) or a 140-µm cap thickness (n = 47) to treat myopia or myopic astigmatism, if not both. In an analysis of right eyes only during the 12-month follow-up period, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive outcomes, and high-order aberrations were evaluated. The distribution of patients by age and sex between the groups did not differ significantly (P = .803 and P = .680, respectively). CDVA, spherical and cylindrical refraction, and changes in total high-order aberration, spherical aberration, coma, and trefoil were similar between the groups at 6 and 12 months, postoperatively. However, UDVA was statistically significantly higher in patients with 140-μm cap thicknesses than with 120-μm cap thicknesses at 6 and 12 months postoperatively (P < .001 and P < .001, respectively). Patients with 140-µm cap thickness showed greater improvement in UDVA than ones with 120-µm cap thickness at 12-month follow-up (P = .005). Both 120- and 140-μm cap thicknesses in small incision lenticule extraction were safe and effective thicknesses for correcting myopia or myopic astigmatism. The patients with 140-μm cap thickness had better improvement in UDVA after 12-month follow-up compared to patients with 120-μm cap thickness.
Experimental schematic (A, B, C) and representative photographs of tumors according to ablation dose (D, E). A Laser ablation of PANC-1 cancer cells in xenografted mice. B Gross examination of harvested tumors. C Study schematic. D Immediately after laser ablation. E Three days post-LA
H&E staining of tumor cross-sections. A C: Central core of tumor tissue burned by the laser (red). CN: Coagulated and necrotic tumor after laser irradiation (blue). Necrosis: Necrotic tissue (yellow). P: Non-treated tumor tissue. Scale bar, 1000 μm. B Cross-section of a tumor and H&E-stained sections, day 0 (immediately after ablation) and day 3 (3 days after ablation at 200 J). Tumor tissues were analyzed using 5 sections per 2 mm
Comparison of necrotic areas according to the sections in animals exposed to 200, 400, 600, 800, and 1000 J of laser energy. Left: day 0. Right: day 3
Comparison of necrotic areas (mm²) immediately after and at 3 days after laser ablation. A Necrotic areas immediately after laser ablation. **p < 0.01, #p < 0.05, and + p < 0.05. B Necrotic areas 3 days after laser ablation. ***p < 0.01, ###p < 0.001, and +  + p < 0.001. C Correlation between laser ablation doses and necrotic areas immediately after laser ablation, r = 0.374, p = 0.001. D Correlation between laser ablation dose and necrotic areas 3 days after laser ablation, r = 0.776, p < 0.001
Central cores of vaporized areas immediately after laser ablation
Pancreatic cancer (PC) is a leading cause of cancer death and its incidence and mortality have shown an increasing trend. Despite improvements in outcomes, another treatment option is required for PC. Laser ablation (LA) has been evaluated for the treatment of various types of cancer. The aim of this study was to assess the safety and feasibility of a novel cylindrical light diffuser in a xenograft model of PC. This study was performed using a customized high-power laser system. PANC-1 cells and BALB/c mice were used for experiments at a laser power of 5 W for 40 to 200 s at five different energy levels (n = 30). There was no acute bleeding or major complication. Using the cylindrical light diffuser, tumors were irradiated with similar size in each energy group. A correlation between laser dose and tumor necrosis was observed. Pearson’s correlation for the relation between the amount of necrosis area and laser ablation energy on day 3 was 0.78 (p < 0.01). No statistical difference of necrosis area was exhibited when the necrosis area of each harvested tumor analyzed by dividing into 5 specimens for each energy. The study demonstrates that LA treatment using a cylindrical light diffuser induced remarkable tumor necrosis at histopathologic examinations. Laser ablation dosage and tumor response were strongly correlated, and the ablation procedure resulted in homogeneous tissue necrosis. No adverse event was encountered. These findings suggest that the devised cylindrical light diffuser offers a safe and effective means of treating pancreatic cancer.
Laser lipolysis is a promising body contouring technology. However, the skin tissue could be thermally damaged owing to the laser energy absorption by water, which limits the lipolysis efficiency. To protect skin tissue and improve the lipolysis effect, cryogen spray cooling is introduced and synergized with the pulsed laser irradiation aiming to propose a new therapy protocol. By simulating heat conduction in the skin after spray cooling assisted laser lipolysis, the temperature distribution in the skin tissue was obtained to analyze the tissue damage by the Arrhenius integral. After parameter optimization according to the damage threshold of skin and adipose tissue, a new protocol with high laser intensity and short time was proposed including 150-ms R134a spray cooling with spray distance of 30 mm, and 100 ms 1064 nm laser irradiation with energy density of 20 J/cm², with a relaxation for 9.75 s. This cycle of 10 s can be repeated 90 to 150 times for a total of 15 to 25 min. Compared with previous treatment procedure, new protocol can increase the fat dissolution depth from 2 to 4.5 mm beneath the dermis with same order laser fluence.
Flow chart for patents with propensity score matching
Low-level laser therapy (LLLT) has been a treatment modality by many androgenetic alopecia (AGA) patients in recent years. It remained unclear as to how long the treatment regime should be maintained, and which characteristics of patients should this be recommended. A real-world study was carried out with an FDA-cleared low-level laser helmet for 1383 patients. Ordinal logistic regression analysis with propensity score matching (PSM) was used to investigate the factors related to efficacy assessment. More than 80% of users were between 18 and 40 years old. The median use times were 133 for mild AGA patients and 142 for moderate-to-severe AGA patients, which equated to 38 weeks and 40 weeks, respectively. The overall clinical effectiveness was nearly 80%. PSM analysis revealed that gender (P = 0.002), use period (P = 0.068), scalp conditions with dandruff, rash, and itchy symptoms were associated with the grading of efficacy assessment. Male users (ordinal OR: 1.35, CI: (1.01, 1.79)); use for more than 180 times or use period for 1 year (ordinal OR: 1.40, CI: (1.11, 1.96)); and those with scalp dandruff (ordinal OR: 1.34, CI: (1.01, 1.87)), rash (ordinal OR: 1.47, CI: (1.04, 2.07)), and itchy symptoms (ordinal OR: 1.51, CI: (1.12, 2.03)) had better efficacy assessments. The recommended treatment regime with low-level laser helmet was more than 1 year or 180 use times. Male patients with dandruff, rash, and itchy symptoms in scalps tended to have a better efficacy assessment.
Viability of cultured human dental pulp stem cells (hDPSCs) on Er:YAG or air-abrasion decontaminated titanium discs. The cell viability was evaluated using MTT assay at 24 h after culture. The graph shows “mean ± SD” for four independent experiments. Stars on the top of the columns represent P < 0.05 compared with the corresponding negative control group. Stars between columns (linked with horizontal lines) indicate a significant difference between experimental groups (P < 0.05)
Alkaline phosphatase activity on experimental titanium discs. ALP activity was assessed 30 days after culture. The graph shows mean ± SD for four independent experiments. Stars at the top of the columns indicate a statistically significant difference (P < 0.05) from the negative control group in each experiment
Osteocalcin production on decontaminated titanium surfaces compared to control discs, 28 days after culture. Gene expression was assessed using real-time PCR. The graph shows mean ± SD for four independent experiments. Stars at the top of the columns indicate a statistically significant difference (P < 0.05) from the negative control group in each experiment
Alizarin red staining of cultured cells in experimental specimens (top figure from a–d, respectively) and the view of each experimental group under the light microscope at 20 × (bottom): a sterile group (top-left of the bottom figure); b Er:YAG laser decontaminated group (top-right of the bottom figure); c air-abrasion decontaminated group (bottom-left of the bottom figure); d contaminated group (bottom-right of the bottom figure)
SEM micrographs (magnification 1000 × (column 1); 5000 × (column 2); 10,000 × (column 3) and 25,000 × (column 4)) of cultured human dental pulp stem cells (hDPSCs) on experimental titanium discs after 30 days of culture: 1a–4a Sterile group, showing hDPSCs grown on titanium discs in different magnifications. 1b–4b Contaminated group, demonstrating Escherichia coli presented on titanium discs. 1c–4c Er:YAG decontaminated group, stretched with filopodia hDPSCs. 1d–4d Air-abrasion decontaminated group, less stretched with filopodia hDPSCs in comparison with 1c–4c. White arrows indicate bacteria (Escherichia coli) whereas white arrow in heads in other figures shows hDPSCs
Decontamination of implant surfaces is important to the treatment of peri-implantitis. Er:YAG laser and air-powder abrasion system are regarded as the most effective means of decontamination of implant surfaces. The aim of this in vitro study was to compare the activity of human dental pulp stem cells (hDPSCs) cultured on decontaminated sandblasted titanium discs using Er:YAG laser irradiation and air-powder abrasion. Forty-five titanium discs were contaminated with Escherichia coli (E. coli) bacteria and fifteen titanium discs served as sterile control groups. Thirty contaminated titanium discs were decontaminated with Er:YAG laser or air-powder abrasion system and fifteen contaminated discs were used as contaminated control group. Afterwards, hDPSCs were seeded on all sixty experimental titanium discs. The effects of two decontamination tools on hDPSCs viability were evaluated by MTT assay. Alkaline phosphatase (ALP) activity assay, quantitative real-time PCR analysis and alizarin red staining method were performed to assess hDPSCs osteogenic differentiation. Scanning microscope electron (SEM) was also used to evaluate the effects of two different decontaminated methods on cellular morphology. Our study showed that decontamination using Er:YAG laser caused maximum cell viability. However, the ALP activity was not different in laser and air-abrasion groups. The significant expression of an osteoblastic marker and stronger Alizarin red staining were observed in laser irradiation groups. In addition, SEM observation indicated that grown cells were more stretched and more filopodia in Er:YAG-treated discs. In the present study, Er:YAG laser and air-powder abrasion improved the activity of the cells cultured on the decontaminated titanium discs. However, in comparison with air-powder abrasion, Er:YAG laser was more effective.
The 1064 nm Nd:YAG laser shows a good prospect for the treatment of port-wine stain (PWS), but it is necessary to enhance the blood absorption to laser energy by exogenous chromophore. Owing to the conjunction effect of local surface plasmon resonance (LSPR) by gold nanoparticle and drug delivery as well as lumen blockage abilities by liposome, liposome@Au core–shell nanoparticles are used as exogenous chromophore, and the efficiency of photothermal therapy is studied systematically. In this work, theoretical simulations were conducted to investigate the electric field and solid heat conduction of liposome@Au core–shell nanoparticles with various size and particles distance, aiming to achieve maximum photothermal conversion efficiency during the laser irradiation. Thereafter, liposome@Au core–shell nanoparticles with optimal size and structure were prepared, and in vivo experiments were conducted to evaluate the thermal damage of blood vessels enhanced by liposome@Au core–shell nanoparticles. Theoretical results imply that maximum temperature rise (167 K) is obtained when radius is 45 nm and shell thickness is 5 nm with distance of 4 nm. Liposome@Au core–shell nanoparticles were prepared with diameter of 101 nm and shell thickness of 5 nm according to the finite element simulation of electric field and solid heat conduction. When the molar ratio of chloroauric acid to phospholipid is 2.25, the LSPR absorption peak is about 981 nm, which is close to the wavelength of Nd:YAG laser. In vivo experiments show that injecting liposome@Au core–shell nanoparticles into the blood vessels can effectively reduce the number of laser pulses and the corresponding energy density required for obvious vasoconstriction.
Melanoma is a metastatic cancer resistant to a wide range of therapies, including standard chemotherapy and radiation therapy, and cannot be treated with existing treatments owing to its intrinsic drug resistance. In terms of convenience and cheap cost of fabrication, one of the novel treatments is using polydopamine-coated iron oxide nanoparticles (IONs@PDA). Iron oxide nanoparticles (IONs) were synthesized (7.36 nm) and coated with polydopamine (15-20 nm). To examine the effect of photothermal ablation in melanoma cells (B16-F10), a Q-switched ruby laser (λ = 694 nm, spot size = 4 mm, output power = 5 J/s) was used. The prepared nanoprobe was applied to mice, and their survival after treatment was evaluated. Then histopathological studies were done on the livers and skins of the treated mice. The nanoparticles absorb the laser, raising the temperature and initiating photothermal treatment, with significant apoptosis (74%) after the 4th time of treatment. Photothermal therapy (PTT) by using IONs@PDA proved to be effective in the treatment of melanoma cells (tumor size of < 2 mm) without side effects. The lifespan of mice was significantly increased in a group of mice post-administered IONs@PDA and laser ablation. The fabricated nanoprobe (IONs@PDA) enhanced the melanoma cell apoptosis in the mice model, and it has promise for the treatment of melanoma (B16-F10) cells using photothermal therapy.
Flow diagram for study selection
Risk of bias summary of included studies
Forest plot for BOP. aPDT, antimicrobial photodynamic therapy; BOP, bleeding on probing; IV, inverse variance; MB, methylene blue; PC, phenothiazine chloride; P-iM, peri-implant mucositis; 3 M, 3 months; 6 M, 6 months
Forest plot PD. aPDT, antimicrobial photodynamic therapy; IV, inverse variance; MB, methylene blue; PC, phenothiazine chloride; PD, probing depth; P-iM, peri-implant mucositis; 3 M, 3 months; 6 M, 6 months
Forest plot for PI. aPDT, antimicrobial photodynamic therapy; IV, inverse variance; MB, methylene blue; PC, phenothiazine chloride; PI, plaque index; P-iM, peri-implant mucositis; 3 M, 3 months; 6 M, 6 months
Antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunctive treatment strategy for peri-implant diseases. This systematic review aimed to determine whether aPDT as an adjunct to mechanical debridement has an additional benefit for smokers with peri-implant diseases. Randomized controlled trials (RCTs), which evaluated the clinical outcomes of mechanical debridement alone versus mechanical debridement + aPDT among smokers, were considered eligible to be included. The primary outcome was bleeding on probing (BOP) and secondary outcomes included probing depth (PD), plaque index (PI), and crestal bone loss (CBL). Meta-analyses using a random-effects model were conducted to calculate the mean difference (MD) with a 95% confidence interval (CI). The quality of evidence was assessed according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). A total of four RCTs (188 participants) were included. The aPDT group showed significantly improved PD (MD = − 1.26, 95% CI = − 2.19 to − 0.32, p = 0.008) and PI (MD = − 10.6%, 95% CI = − 14.46 to − 6.74%, p = 0.0001) compared with mechanical debridement group at 3-month follow-up. No significant difference in bleeding on probing (BOP) was observed at 3-month follow-up (MD = − 0.60%, 95% CI = − 2.36 to 1.16%, p = 0.50). The subgroup analyses on photosensitizers demonstrated significant differences between the two groups on PD (MD = − 1.23, 95% CI = − 2.41 to − 0.05, p = 0.04) and PI (MD = − 12.33, 95% CI = − 14.74 to − 9.92, p < 0.00001) by the use of methylene blue (MB). Within the limitation of this study, compared with mechanical debridement alone, combined use of aPDT was more effective in reducing PD and PI in smokers at 3-month follow-up. MB was a predictable photosensitizer for aPDT. However, the findings should be interpreted with caution due to the limited number of included studies, methodological deficiencies, and heterogeneity between studies.
A Eight points of laser application used in the treatment of Bell’s palsy (adapted from Bernal 1993). B Scanned area of MLS laser on the affected facial side
Flow diagram of the study
Comparison of the HBS, PEFI, and SFDI among treatment groups
The objective of this study is to investigate the effect of scanning and point application of multiwave locked system (MLS) laser therapy on the recovery of patients with idiopathic Bell’s palsy (IBP). A randomized double-blind placebo-controlled trial was carried out on 60 patients with subacute BP. Patients were randomly assigned into three groups of 20 patients each. Facial massage and facial exercises were applied to all patients. Group one received MLS laser as a manual scanning technique (10 J/cm², area 50cm², total energy 500 J). Group two received MLS laser using point application technique (10 J/point, 8 points, total 80 J). Group three received placebo laser. House–Brackmann scale (HBS) and facial disability index (FDI) were used to evaluate the facial recovery. Assessment was performed at baseline and after 3 and 6 weeks of treatment. Comparison within and between groups was performed statistically with significance level p < 0.05. Results showed significant improvement in the FDI and HBS after treatment in all groups. Both scanning and point application significantly improved the score of FDI and HBS more than placebo group. Scanning technique combined with facial massage and exercises had a more significant effect than the point application group or the placebo group in improving FDI and HBS scores after 3 and 6 weeks of treatment. The MLS laser is an effective physiotherapy method used for the treatment of patients with IBP. MLS laser in scanning or point application techniques was more effective than exercise alone with greater effect of scanning technique than point application technique.
CONSORT flowchart of the study
Appearance of the gingiva a before, b, c during and d 6 months after treatment in the control group. UNC-15 probe with acrylic guide stent in place in a and d
Appearance of the gingiva a before, b during and c 6 months after treatment in the test group, with the help of d diode laser. UNC-15 probe with acrylic guide stent in place in a and c
Lasers have been found to be effective as an adjunctive in periodontal therapy. The objective of the study was to compare the outcomes of non-surgical adjunctive use of 980-nm diode laser to that of conventional flap surgery in terms of clinical outcome measures and radiographic osseous defect depths. This study was designed as a double-blinded split-mouth randomised controlled clinical trial. A total of fifteen patients (30 quadrants) with generalised periodontitis stage III grade B were randomly assigned test group (diode laser) and control group (conventional flap surgery). Both test and control groups had 15 quadrants each. At 3 months, the probing pocket depth (PPD) was 3.46 ± 0.19 mm (test) and 4.20 ± 0.20 mm (control), with a statistically significant difference between the groups (p = 0.01). Similarly, at 6 months re-evaluation, PPD was 1.46 ± 0.12 mm (test) and 2.33 ± 0.13 mm (control) with a highly significant statistical difference (p = 0.001). Plaque index showed a difference between both test and control groups at baseline, 3 months and 6 months (p = 0.001) while gingival index, modified sulcular bleeding index and radiographic osseous defect depth showed a difference at 3 months and 6 months (p = 0.001). Within the study’s limitations, 980-nm diode laser can result in significant improvements in the clinical and radiographic parameters and is very well tolerated by the subjects.
Narrowband UVB (NB-UVB) has been shown to be effective for the treatment of early mycosis fungoides (MF) in light-skinned patients, but the effect of NB-UVB on patients with darker skin phototypes needs further investigation. The aim of this study was to evaluate the effect of NB-UVB in the treatment of early-stage MF in Iranian patients. In this retrospective study, 24 patients with the diagnosis of early MF (9 stage AI, 15 stage IB) were enrolled. All patients were treated with NB-UVB phototherapy 2-3 times weekly. After achieving complete response, a maintenance treatment was recommended. The response rate, side effects, and recurrence rate in the follow-up period were assessed. The follow-up period was ranged 6 to 24 months. Ten patients (41.7%) had complete remission after a mean number of 42.9 treatment and mean cumulative dose of 58.11 J/cm2. Twelve patients (50%) had partial response, and 2 patients (8.3%) had no response. After discontinuation of maintenance treatment, 4 of 10 patients (40%) with complete remission relapsed within a mean of 5 months. Side effects were limited to erythema (12.5%) and hyperpigmentation (4%). NB-UVB is a safe and effective method for the treatment of early MF, but it seems that more treatment sessions and higher doses of NB-UVB are required for darker skin phototypes.
Cancer is a life-threatening disease that has claimed the lives of many people worldwide. With the current diagnostic methods, it is hard to determine cancer at an early stage, due to its versatile nature and lack of genomic biomarkers. The rapid development of biophotonics has emerged as a potential tool in cancer detection and diagnosis. Using the fluorescence, scattering, and absorption characteristics of cells and tissues, it is possible to detect cancer at an early stage. The diagnostic techniques addressed in this review are highly sensitive to the chemical and morphological changes in the cell and tissue during disease progression. These changes alter the fluorescence signal of the cell/tissue and are detected using spectroscopy and microscopy techniques including confocal and two-photon fluorescence (TPF). Further, second harmonic generation (SHG) microscopy reveals the morphological changes that occurred in non-centrosymmetric structures in the tissue, such as collagen. Again, Raman spectroscopy is a non-destructive method that provides a fingerprinting technique to differentiate benign and malignant tissue based on Raman signal. Photoacoustic microscopy and spectroscopy of tissue allow molecule-specific detection with high spatial resolution and penetration depth. In addition, terahertz spectroscopic studies reveal the variation of tissue water content during disease progression. In this review, we address the applications of spectroscopic and microscopic techniques for cancer detection based on the optical properties of the tissue. The discussed state-of-the-art techniques successfully determines malignancy to its rapid diagnosis.
Participant flow chart
DPL concomitant with oral isotretinoin accelerated the onset of effects and showed better effects than the isotretinoin monotherapy control. Patients received low-dose oral isotretinoin, one side of the face was treated with DPL at low energy, the other side served as control (Ctrl.). a GAGS score, number of b papules, c pustules, and d comedones were counted before each therapy (week 0–6), and 4 weeks after the last therapy (week 10). e Representative photographs of 2 patients before the study (baseline) and at week 10. Data shown are mean ± SEM with n = 33. *p < 0.05, **p < 0.01, ***p < 0.001
Isotretinoin in combination with DPL facilitated the repairment of skin barrier. Patients received low-dose oral isotretinoin, one side of the face was treated with DPL, the other side served as control (Ctrl.). a Transepidermal water loss (TEWL), b erythema index (EI), and c melanin index (MI) were detected 4 weeks after the last therapy (week 10). Mean ± SEM, n = 33. *p < 0.05, **p < 0.01, ***p < 0.001
The improvement and satisfactory score were higher on DPL-treated side than on the control side. a % of improvement was calculated as (week 10 − week 0)/week 0 × 100%. b Patients’ satisfactory score was assessed at week 10. Mean ± SEM, n = 33. ***p < 0.001
Acne vulgaris (AV) is a common dermatosis that causes psychological problems. Isotretinoin is the first-line treatment for moderate-to-severe AV, but its onset of effect is delayed. Although light-based therapy is widely used in the treatment of AV, there is a lack of reports on delicate pulsed light (DPL) which has a narrow therapeutic spectrum (500-600 nm). Low-level light therapy (LLLT) has shown an emerging role in anti-inflammatory effects and skin repair. This study investigates the efficacy and safety of low-dose oral isotretinoin combined with LLLT using DPL in patients with moderate-to-severe AV. Thirty-six patients with moderate-to-severe AV were enrolled and received low-dose oral isotretinoin (10-20 mg/day). The two sides of the face were randomly assigned to receive DPL (6-9 J/cm2) or not at an interval of 2 weeks for 4 treatment sessions (weeks 0, 2, 4, 6). Photos, GAGS score, counts of papules, pustules, comedones, TEWL, melanin and erythema index, side effects, efficacy, and satisfactory score were recorded at each visit and at 4 weeks after the final treatment (week 10). Thirty-three patients completed the study. DPL and oral isotretinoin combined therapy exhibited significantly improved GAGS score as well as the number of the lesions from week 2 and maintained until week 10. At the end of the observation, the improvement of GAGS was 70.88% on the DPL and isotretinoin combined side versus 62.12% on the side with isotretinoin monotherapy (p = 0.0009). The improvement for papule number was 61.58% on the DPL combined side versus 43.33% on the control side (p < 0.0001), for comedone was 63.15% versus 43.30% (p = 0.0008). TEWL and indexes of melanin and erythema also had better outcomes with DPL combined therapy at week 10. All the side effects were temporary and tolerable; no adverse effects were observed. Oral low-dose isotretinoin combined with LLLT by DPL offers a combination with reduced side effects and better outcomes within a limited treatment duration, which advances the onset of effect of isotretinoin monotherapy and improves lesion clearance.
Flow diagram of study (n = number of patients)
Graphical display of ΔE00 values in diode laser and LED-activated bleaching
Color evaluation of LED-activated bleaching at baseline (a), immediately after (b), and at 9 months (c). Color evaluation of diode laser-activated bleaching at baseline (d), immediately after (e), and at 9 months (f)
This study aims to evaluate the effect of diode laser- or LED-activated tooth bleaching on color change, tooth sensitivity(TS), temperature variation, and gingival irritation (GI) for 9 months. Thirty-five subjects having anterior teeth with a color of A2 or darker were enrolled in the study. In a split-mouth design, one side of each arch was activated by a diode laser (Epic X, Biolase), and the other side was activated by an LED (Radii Plus, SDI) in conjunction with a bleaching agent (35%, Whiteness HP). The color change was evaluated by subjective (VitaClassic/Vita3D Master Bleachguide) and objective (spectrophotometer, Vita Easyshade) methods for up to 9 months. TS and GI were assessed by visual analogue scale (VAS) and gingival index, respectively, at the same recall periods. During the bleaching, the temperature variation was also recorded using a thermocouple. Statistical analyses were performed (p < 0.05). In the color evaluation, no statistically significant difference was found between diode laser and LED (p > 0.05), except for the 6-month spectrophotometric assessment (ΔE00, ΔEab), where higher values were obtained with the laser (p < 0.05). The temperature difference and maximum temperature with diode were found to be significantly higher than LED (p < 0.05). Higher values were obtained with LED when the mean temperatures were compared (p < 0.05). There was no difference between the two activation methods in terms of TS and GI at any of the recalls (p > 0.05). The bleaching activated either with diode laser or LED performed similar clinical performance in terms of effective color change, tooth sensitivity, and gingival irritation with minimum temperature variations.
PRISMA flow diagram for the current systematic review [14]
a Diagrammatic representation of placement of the radial fiber flush (fEVLA) at the saphenofemoral junction. Radial energy application targets the vein wall preventing damage to the deep veins and EHIT. b Diagrammatic representation of non-targeted and forward heat transfer by bare fiber, which when used flush may cause damage to the deep veins. CFV common femoral vein, SEV superficial epigastric vein, AASV anterior accessory saphenous vein, PASV posterior accessory saphenous vein, P1 proximal ostial point at the saphenofemoral or sapheno-popliteal junction, P2 distal ostial point at the saphenofemoral or sapheno-popliteal junction
The aim of this systematic review was to summarize the currently available literature reporting clinical application of endovenous laser ablation (EVLA) by means of laser systems emitting at wavelengths > 1900 nm, pertaining dosimetry, intraoperative parameters, postoperative outcomes, and efficacy based on occlusion rates, recanalization, and postoperative complications. A literature search was conducted in PubMed, Cochrane Library, Embase, OVID, and Web of Science for publications since the year 2000 until December 2021. Case series, prospective trials, retrospective studies, and randomized controlled trials describing the application of a 1920/1940-nm wavelength laser for EVLA in humans with a minimum of one postoperative follow-up visit were included in the study. Four case series and one randomized controlled trial with a total of 509 EVLA procedures (396 great saphenous veins and 113 small saphenous veins) were identified, meeting the inclusion criteria. The studies were heterogenous in their documentation, EVLA, and duplex ultrasound protocol and result reporting. Overall, the applied average cumulative LEED values ranged from 17.8 to 53 J/cm. Complications observed were pigmentation (0–9.75%), paresthesia (2.5–7.3%), thrombophlebitis (0–5%), EHIT Class 2 (2.26–2.4%), and EHIT Class 1 (1.2–2.4%). Four cases of recanalizations were observed in one study cohort within the first month after treatment. Follow-up at 12 months was available for 3 studies (procedures n = 218) with recanalizations in 8 limbs. Follow-up at 24–36 months was available for 2 studies (procedures n = 126) showing recanalizations in 5 limbs. Recanalizations were asymptomatic and incidental findings on follow-up duplex ultrasound. Pooled occlusion rates were 99.2% at 1 M, 96.3% at 12 M, and 96% at 24 M. Overall, patients undergoing EVLA with long wavelength laser systems > 1900 nm show high occlusion rates, significant improvement in VCSS, low postoperative complication rate, low pain levels, low analgesic requirement, and early convalescence. Apart from persistent paresthesia, all the complications regressed spontaneously within 6 months. EVLA by means of 1920/1940 nm shows promising clinical results with high efficacy and low complication rates. Heterogeneity still exists regarding ideal protocol for duplex ultrasound examination and documentation of anatomical parameters (e.g., vein diameter, ideal stump length and status of accessory veins) and light dosimetry for EVLA.
Acute myocardial infarction (MI) is found to be a major causative factor for global mortality and morbidity. This situation demands necessity of developing efficient and rapid diagnostic tools to detect acute MI. Raman spectroscopy is a non-destructive optical diagnostic technique, which has high potential in probing biochemical changes in clinical samples during initiation and progress of diseases. In this work, blood was taken as the sample to examine inflammation in acute MI patients using Raman spectroscopy. Ratio of Raman peak intensities that corresponds to phenylalanine (1000 cm ⁻¹ ) and tyrosine (825 cm ⁻¹ ) can facilitate indirect information about tetrahydrobiopterin (BH4) availability, which can indicate inflammatory status in patients. This ratio obtained was higher for MI patients in comparison with control subjects. The decrease in phenylalanine and tyrosine ratio (Phe-Tyr ratio) is attributed to the prognosis of standard of care (medications like antiplatelets including aspirin, statin and revascularisation) leading to inflammation reduction. Phe-Tyr ratio estimated from the Raman spectra of blood can be exploited as a reliable method to probe inflammation due to MI. The method is highly objective, require only microliters of sample and minimal sample preparation, signifying its clinical utility.
Profile of diameter distribution of MB/NE (black) and unloaded NE (gray) from DLS analyses after 83 days of synthesis
Spectra of fluorescence emission in UV/Vis of free MB (black) and MB/NE (gray) with maximum excitation at 645 nm, emission 674 nm, and spectral slits 3.0/3.0 nm and 5.0/5.0 nm for free and nanoencapsulated MB respectively (A) and spectra of absorbance with maximum at 655 nm at insert (B)
In vitro cytotoxicity test in NIH/3T3 fibroblast cells (ATCC® CRL-1658) of MB/NE (black) and free MB (white) (B). Cells were incubated in different MB/NE concentrations (10, 25, 50, 75, 100, 125 μmol·L⁻¹) and free MB (100 and 125 μmol·L⁻¹) concentrations (A). Statistical significance was determined using the one-way ANOVA analysis of variance test followed by the Tukey post-test for multiple comparisons. Data were presented as mean ± SEM of three independent experiments (CT, control, *p < 0.001)
In vitro photodynamic therapy assay using MB/NE (50 μmol·L⁻¹) in OSCC cells (A) in different fluences at λ = 660 nm (0.5, 5, and 10 J·cm⁻²) (B). Statistical significance was determined using the one-way ANOVA analysis of variance test followed by the Tukey post-test for multiple comparisons. Data were presented as mean ± SEM of three independent experiments (CT, control, *p < 0.01; **p < 0.001)
In vitro photodynamic therapy assay using MB/NE (50 μmol·L⁻¹) in HeLa cells (A) in different fluences at λ = 660 nm (0.5, 5, and 10 J·cm⁻²) (B). Statistical significance was determined using the one-way ANOVA analysis of variance test followed by the Tukey post-test for multiple comparisons. Data were presented as mean ± SEM of three independent experiments (CT, control, *p < 0.001)
Photodynamic therapy (PDT) is a therapeutic modality with high contributions in the treatment of cancer. This approach is based on photophysical principles, which presents as a less invasive strategy than conventional therapies. Combined with nanotechnology, the therapy becomes more efficient because nanoparticles (NPs) have advantageous characteristics such as biocompatibility, controlled, and targeted release, promoting solubility and decreasing the toxicity and side effects involved. In this work were developed nanoemulsions containing the methylene blue photosensitizer (MB) (MB/NE) and in the empty form (unloaded/NE). Subsequently, the mentioned nanomaterials were characterized by the measurement of dynamic light scattering (DLS). The MB/NE and unloaded/NE showed appropriate physical and chemical characteristics, with particle size ≤ 200 nm, polydispersity index close to 0.3, and zeta potential exhibiting negative charge, showing stable values during the analysis. The incorporation of the MB did not cause changes in the photophysical profile of the photosensitizer. The quantification performed showed an incorporation rate of 81.9%. Viability studies showed an absence of cytotoxicity for MB/NE in the concentrations of 10–75 µmol·L⁻¹, free MB at the concentration of 75 µmol·L⁻¹, and unloaded NE 47.5% (v/v), presenting viability close to 90%, respectively. PDT in vitro protocols applied to OSCC and HeLa cells showed a decrease in cell viability through only one irradiation, evidencing the photodynamic activity of the formulation when applied to cancer cells. The results obtained were superior to those found in the literature where they use free MB, showing that the association between nanotechnology and PDT optimizes the proposed protocol. From the results obtained, it is possible to indicate that the NE have high stability, with satisfactory physical–chemical parameters, in addition to not presenting cytotoxicity in the tested concentrations, showing their in vitro biocompatibility, in addition to presenting satisfactory effects when combined MB/NE with PDT, showing the potential of MB/NE as a very promising nanostructured photosensitizer for the treatment of some types of cancer. Graphical abstract
The study aimed to design a reliable and straightforward PBM method by implanting a medical scattering fiber above surgically exposed spinal cord in SCI patients. Moreover, the safety of this method was examined. Twelve patients with acute SCI (ASIA B) requiring posterior decompression were recruited. The medical scattering fiber was implanted above the spinal cord, and was continuously irradiated at 810 nm, 300 mW, 30 min/day, once per day for 7 days. The vital signs (temperature, blood pressure, respiratory rate, heart rate, and oxygen saturation), infection indicators (WBC, NEUT, hs-CRP, and PCT), photo-allergic reaction indicators (Eosinophil and Basophil), coagulation function indicators (PT, APTT, TT) and neurological stability indicators (ASIA sensory and motor scores) were recorded to evaluate the safety of PBM. Three months after surgery, 12 patients completed follow-up. In our study, direct PBM on SCI site did not cause clinically pathologic changes in vital signs of the patients. All patients had higher WBC, NEUT, and hs-CRP at day 3 during irradiation than those before surgery, and returned to normal at day 7. The changes in Eosinophil and Basophil that were closely associated with allergic reactions were within normal limits throughout the course of irradiation. The coagulation function (PT, APTT, and TT) of patients were also in the normal range. The ASIA sensory and motor scores of all patients had no changes throughout the irradiation process. However, in the follow-up, both ASIA sensory and motor scores of all patients had minor improvement than those in pre-irradiation, and 7 patients had adverse events, but they were not considered to be related to PBM. Our study might firstly employ direct PBM in the SCI by using scattered optical fibers. In a limited sample size, our study concluded that direct PBM at the site of SCI would not produce adverse effects within the appropriate irradiation parameters. The method is safe, feasible, and does not add additional trauma to the patient. Our preliminary study might provide a new methodology for the clinical PBM treatment of acute SCI.
Backround Early treatment of oral precancerous lesions is considered as a key strategy for in oral carcinogenesis prevention. Increasing evidence has suggested that the transforming growth factor beta (TGF-β) signaling pathway is tightly involved in the process of oral-carcinogenesis. In this study, we investigated the inhibition effect and potential mechanism of 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) in human oral precancerous cells via TGF-β pathway. Materials and methods Here, the dysplastic oral keratinocyte (DOK) cells were incubated with ALA concentration of 1 mM/mL for 4 h and then irradiated with a Helium–Neon (He–Ne) ion laser at 633 nm (200 mW/cm²). The control cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) medium. We analyzed the differentially expressed genes and correlated pathways in oral precancerous cells following ALA-PDT using Affymetrix microarrays. TGF-β pathway was analyzed by quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. Bioinformatics analysis was performed to evaluate the expression of TGF-β1 in human oral cancer samples and adjacent normal samples. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), flow cytometry, 2′-7′-dichlorodihydrofluorescein diacetate (DCFH-DA), and wound healing assay were used to assess the effects of ALA-PDT plus TGF-β receptor inhibitor (LY2109761) in DOK cells. Results The TGF-β signaling could exert in suppressive effects on DOK cells after ALA-PDT. The cell proliferation and migration rate of DOK cells was significantly reduced and apoptosis and ROS generation induced more effectively by ALA-PDT combined with LY2109761. Furthermore, cell cycle analysis revealed that the combined treatment resulted in G0/G1 phase arrest. Conclusions ALA-PDT suppresses the growth of oral precancerous cells by regulating the TGF-β signaling pathway, and its suppressive effect was enhanced using LY2109761. These results indicate that it could be a promising alternative treatment against oral precancerous lesions.
Top-cited authors
Paulo De Tarso Camillo De Carvalho
  • Universidade Nove de Julho
Norbert Gutknecht
  • RWTH Aachen University
Rodrigo Alvaro Brandão Lopes-Martins
Nivaldo A Parizotto
  • Brasil University
Jan Magnus Bjordal
  • University of Bergen