Lasers in Medical Science最新文献

Although the technologies for auricular reconstruction in microtia have improved, issues such as low hairlines or excessive hair growth can still pose aesthetic problems for the reconstructed ear. Laser depilation has been reported as a solution for hair problems. However, few studies have discussed the appropriate region for hair removal. A retrospective analysis was performed on 276 patients with unilateral microtia who underwent the Nagata two-stage ear reconstruction. The gender ratio of male to female was 2.5 (198 males/78 females). Intense pulsed light depilation was used to remove hair. To determine the proper hair removal area, we measured the extent of hair removal. Before the first stage, the average vertical distance between the upper point (after localization) and hairline was 3.42 ± 4.75 mm (-10-20 mm). After the first stage, the average vertical distance between the upper point of the reconstructed ear and the hairline was 1.27 ± 2.41 mm (-10-15 mm). By using chi-square test to assess differences in hair removal success rates among various regions, we aimed to identify the suitable depilation region. Before the first stage, a depilation vertical distance ≥ 10 mm led to a 92.1% success rate. After the first stage surgery, among the patients needing additional hair removal, a vertical depilation distance ≥ 4 mm resulted in an 81.3% success rate. Based on our observation, we suggested that a depilation region of ≥ 10 mm (before the first surgery) or ≥ 4 mm (after the first surgery) would be the ideal range for laser hair removal.

Clearance of comedone is challenging in the treatment of acne, as it is very likely to develop into inflammatory lesions. However, there is lack of effective treatments for dense comedones. Comedone extractor has been widely employed by dermatologists, but the effect is temporary and may cause irritation. CO₂ laser is a potential method for dense comedones, but the efficacy and safety need to be explored. In this single-center, randomized, single-blind, self-controlled study, the faces of patients with dense comedones were randomly assigned into two sides receiving either ultra-pulse dynamic CO₂ laser or comedone extraction at an interval of 2 weeks for 4 sessions. After 4 treatments, the average comedone reduction rate of the CO₂ laser was 64.49%, which was higher than that by the extractor (46.36%) (P < .001). 79.16% of the patients reached over 50% reduction by CO₂ laser, while only 37.5% on extractor treated side reached 50% clearance. Texture index, porphyrin index, red zone, erythema index, and transepidermal water loss decreased after both treatments, and CO₂ laser showed more improvement. There was no difference in hydration index and melanin index between the two treatments. No permanent or severe side effects were observed on both sides. The CO₂ laser showed higher comedone clearance with lower pain scores than the comedone extractor.

This scoping review aims to summarize the literature on photobiomodulation (PBM) therapy as an adjunct to resistance exercise among older adults, focusing on its effects on muscle metrics, functional balance, capacity, and physical performance. The participants included were older adults aged ≥ 60 years and either gender. The concept was the application of PBM and resistance exercises with no limits on the context parameters. The databases Medline, Embase, Scopus and Web of Science were searched from inception till February 2024. Methodological quality was assessed using the Cochrane risk of bias 2.0. A total of 10 studies were included in the review. PBM, along with resistance training, was reported in six studies, whereas four reported PBM with isometric fatigue protocol. PBM with a wavelength of 808 nm was given on the belly of the rectus femoris muscle in most of the studies. The common dosimetry parameters used were- power density 35.7 W/cm², energy density 250 J/cm², 8 sites, energy per site 7 J, duration of 70 s per site, spot size per diode of 0.028 cm², and stationary contact of application. The application of PBM therapy alongside resistance exercise has been found to improve muscle metrics, functional capacity, and functional performance and reduce fatigability when compared with the control group in most of the studies. When incorporating PBM therapy as an adjunct to resistance training, it is crucial to consider the dosimetry parameters involved-to achieve the intended therapeutic effect. Adjusting treatment parameters with this information can optimize the effectiveness of PBM therapy and improve treatment outcomes for patients.

To evaluate the efficacy of yellow light-emitting diode (LED) irradiation at 590 nm, alone or in combination with anti-inflammatory active substances against ultraviolet (UV)-induced inflammation in keratinocytes. HaCaT keratinocytes were pretreated with LED yellow light (590 nm) alone or in combination with an antiinflammatory active substance such as glycerophosphoinositol choline (GC), extract of grains of paradise (Aframomum melegueta Schum, AM), or a bisabolol and ginger root extract mixture (Bb-GE) before UVB irradiation. Following each treatment, we measured the levels of inflammatory mediators secreted by keratinocytes. HaCaT keratinocytes treated with UVB (300 mJ cm^-²) and then cultured for 24 h exhibited significantly upregulated expression of proinflammatory factors, including interleukin (IL)-1α, prostaglandin E2 (PGE2), and IL-8. After pretreatment with 590 nm LED, UVB-induced inflammatory responses were significantly inhibited. Co-pretreatment with 590 nm LED irradiation and GC further inhibited the expression of IL-1α and IL-8. IL-8 expression was inhibited by co-pretreatment with 590 nm LED irradiation and AM, whereas PGE2 expression was inhibited by co-pretreatment with 590 nm LED irradiation and Bb-GE. Co-treatment with 590 nm LED irradiation and various active substances modulated UVB-induced inflammation in keratinocytes, suggesting the potential application of this approach to prevent damage caused by voluntary sun exposure in daily life.

The aim of the present study was to evaluate the photothermal effects of a subdermal high-power diode laser at a wavelength (λ) of 1470 nm in the skin of rats. Twenty male Wistar rats were used, divided into 2 groups: placebo laser (PL) and active laser (AL). A high-power diode laser equipment was applied to 5 subdermal vectors on the animal's back region. The results demonstrated that active laser animals showed a better arrangement of collagen fiber bands, an increase in the thickness of the dermis and the number of vessels. Furthermore, animals treated with active laser showed an increased immunoexpression of TGF-β and VEGF compared to the placebo. The present work demonstrated that the subdermal high-power diode laser increases the vascularization and the expression of factors that enhance skin regeneration and may be promising resource in the esthetic and dermatology clinical treatment of skin rejuvenation.

Antimicrobial photodynamic therapy (aPDT) has shown efficacy in inactivating different bacterial species by photosensitizer-induced free radical production. Despite aPDT is considered unable to cause resistant strains, enzymatic pathways for detoxification of reactive oxygen species and transmembrane photosensitizer efflux systems could cause resistance to aPDT. Resistance mechanisms can be evaluated by measurement of mRNA from by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Thus, the aim of this study was to access the mRNA level data obtained by RT-qPCR in bacterial cells submitted to photodynamic therapy. Studies performed on mRNA levels in bacteria after PDT were assessed on MEDLINE/Pubmed. The mRNA levels from genes related to various functions have been successfully evaluated in both Gram-positive and -negative bacteria after aPDT by RT-qPCR. Such an approach has improved the understanding of aPDT-induced effects, and reinforced the effectiveness of aPDT on bacteria, which can cause infections in different human tissues.

Photodynamic therapy (PDT) has significant advantages in the treatment of malignant lung tumors. The research on the mechanism of PDT mediated by hematoporphyrin derivatives (HPD) and its cytotoxic effects on lung cancer cells has primarily focused on lung adenocarcinoma cells. However, the impact of HPD-PDT on lung squamous cell carcinoma has not been thoroughly studied. This study aimed to investigate the effects of 630 nm laser on apoptosis, metastasis, invasion, and epithelial-mesenchymal transition (EMT) in human lung squamous cell carcinoma H520 cells mediated by HPD. H520 cells were divided into four groups: control group, photosensitizer group, irradiation group, and HPD-PDT group. Cell proliferation was assessed using CCK8 assay; cell apoptosis was detected by Hoechst 33258 staining and flow cytometry; cell migration and invasion abilities were evaluated using wound-healing and invasion assays; and protein and mRNA expressions were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) respectively. Results showed that HPD-PDT significantly inhibited cell proliferation, promoted apoptosis (P < 0.05), suppressed cell migration and invasion (P < 0.05), decreased Bcl-2 mRNA expression, and increased Bax and Caspase-9 mRNA expression(P < 0.05). Western blotting analysis indicated increased expression of Bax, Caspase-9, and E-cadherin, and decreased expression of Bcl-2, N-cadherin, and Vimentin (P < 0.05). In conclusion, 630 nm laser mediated by HPD promoted cell apoptosis via upregulation of Bax and caspase-9, and downregulation of Bcl-2, and inhibited cell migration and invasion by regulating EMT in H520 cells.

This study investigates the effectiveness of photobiomodulation therapy (PBMT) in treating chronic high-frequency tinnitus with the TINI device, a near-infrared (830 nm) laser. The study includes preliminary animal experiments with 28 mice and a randomized controlled trial with 56 participants to examine the functional and molecular changes in the auditory system that PBMT may cause. The animal model used sodium salicylate to induce tinnitus, followed by PBMT, which showed promising reductions in the behavioral evidence of tinnitus and a reversal of tinnitus-associated upregulation of vesicular glutamate transporters 2 expression in the ipsilateral dorsal cochlear nucleus (p < 0.05). In the clinical trial, participants with chronic high-frequency tinnitus received trans-tympanic application of the TINI device. The results did not show a significant difference in tinnitus score at the final time point when compared to the sham group. However, questionnaires revealed significant improvements in tinnitus symptoms and psychological outcomes following treatment with the TINI device compared to before treatment (p < 0.05). These findings suggest that while PBMT has potential benefits, its clinical effectiveness may be unclear due to its complex nature and interaction with other conditions. Further research is required to optimize treatment parameters and gain a complete understanding of the therapeutic potential of PBMT in managing tinnitus.

Background: Low-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL).

Methods: Tissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay.

Results: Fibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment.

Conclusion: Our study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.