Impact of Thermo-Responsive N-Acetylcysteine Hydrogel on Dermal Wound Healing and Oral Ulcer Regeneration.

This study investigates the efficacy of a thermo-responsive N-acetylcysteine (NAC) hydrogel on wound healing and oral ulcer recovery. Formulated by combining NAC with methylcellulose, the hydrogel's properties were assessed for temperature-induced gelation and cell viability using human fibroblast cells. In vivo experiments on Sprague Dawley rats compared the hydrogel's effects against saline, NAC solution, and a commercial NAC product. Results show that a 5% NAC and 1% methylcellulose solution exhibited optimal outcomes. While modest improvements in wound healing were observed, significant enhancements were noted in oral ulcer recovery, with histological analyses indicating fully regenerated mucosal tissue. The study concludes that modifying viscosity enhances NAC retention, facilitating tissue regeneration. These findings support previous research on the beneficial effects of antioxidant application on damaged tissues, suggesting the potential of NAC hydrogels in improving wound care and oral ulcer treatment.

Oral ulcer treatment using human tonsil-derived mesenchymal stem cells encapsulated in trimethyl chitosan hydrogel: an animal model study.

BACKGROUND: Oral ulcers are a common side effect of chemotherapy and affect patients' quality of life. While stem cell transplantation is a potential treatment for oral ulcers, its efficacy is limited as the stem cells tend to remain in the affected area for a short time. This study aims to develop a treatment for oral ulcers by using trimethyl chitosan (TMC) hydrogel with human tonsil-derived stem cells (hTMSCs) to increase the therapeutic effect of stem cells and investigate their effectiveness. METHODS: Animals were divided into four experimental groups: Control, TMC hydrogel, hTMSCs, and hTMSCs loaded in TMC hydrogel (Hydrogel + hTMSCs) (each n = 8). Oral ulcers were chemically induced by anesthetizing the rats followed by injection of dilute acetic acid in the right buccal mucosa. After confirming the presence of oral ulcers in the animals, a single subcutaneous injection of 100 µL of each treatment was applied to the ulcer area. Histological analyses were performed to measure inflammatory cells, oral mucosal thickness, and fibrosis levels. The expression level of inflammatory cytokines was also measured using RT-PCR to gauge therapeutic the effect. RESULTS: The ulcer size was significantly reduced in the TMC hydrogel + hTMSCs group compared to the control group. The stem cells in the tissue were only observed until Day 3 in the hTMSCs treated group, while the injected stem cells in the TMC Hydrogel + hTMSCs group were still present until day 7. Cytokine analysis related to the inflammatory response in the tissue confirmed that the TMC Hydrogel + hTMSCs treated group demonstrated superior wound healing compared to other experimental groups. CONCLUSION: This study has shown that the adhesion and viability of current stem cell therapies can be resolved by utilizing a hydrogel prepared with TMC and combining it with hTMSCs. The combined treatment can promote rapid healing of oral cavity wounds by enhancing anti-inflammatory effects and expediting wound healing. Therefore, hTMSC loaded in TMC hydrogel was the most effective wound-healing approach among all four treatment groups prolonging stem cell survival. However, further research is necessary to minimize the initial inflammatory response of biomaterials and assess the safety and long-term effects for potential clinical applications.

Photobiomodulation Recovers the Submandibular Gland in Vismodegib-Treated Rats.

Objective: The submandibular gland (SMG) produces the most saliva, and factors such as aging and chemotherapy can affect its structure and function. However, there are only temporary treatments available for salivary hypofunction. This study aimed to evaluate the effects of photobiomodulation (PBM) on the function of SMG by using a rat animal model and vismodegib, an antagonist of the sonic hedgehog (SHH) pathway. Methods: Vismodegib (10 mg/kg) drug was gavaged orally for 14 days in rats to significantly decrease the SHH signaling proteins [SHH, protein patched homolog 1 (PTCH1), smoothened protein (SMO), glioma-associated oncogene homolog 1 (GLI1)], induce damage in SMG tissue, and affect salivary functional markers AQP5 and Keratin5. After that, in conjunction with vismodegib administration, PBM was performed using an 850 nm high-power light-emitting diode (LED) device treated daily for 6 days at varying total energy densities of 60, 120, and 180 J/cm2 in at least 3 rats per group. The test results were confirmed by Western blot, immunofluorescence staining, and hematoxylin and eosin staining, and the statistics were t-test or one-way analysis of variance (ANOVA) with Tukey's multiple comparisons tests. Results: Significant decreases in the expression of SHH-related proteins (PTCH1, SMO, GLI1, p < 0.05) with damage of SMG ductal cells were observed with vismodegib administration. However, a significant increase in the expression levels of SHH-related proteins (SHH, SMO, GLI1, p < 0.05) and recovery of SMG ductal cells damaged after vismodegib administration were observed for PBM-treated groups. Salivary functional marker AQP5 also showed the same increase or decrease. Conclusions: This study found that vismodegib damages SMG ductal cells and decreases SHH-related proteins and associated salivary functional markers. Also, 850 nm high-power LED recovered the damaged structure of SMG and increased SHH-related proteins and salivary functional markers. The study results suggest that PBM can restore SMG structure and function through SHH signaling.

Endoscope-Assisted Hairline Approach for Head and Neck Masses: A Review.

Conventional surgery through a transcervical incision is indicated for the treatment of certain tumors in the head and neck. However, this method can cause multiple problems, including scarring and cosmetic concerns. The endoscope-assisted hairline approach, which serves as an alternative to conventional surgical procedures, is gaining popularity due to its excellent cosmetic and functional outcomes. However, given the anatomical complexity involved, the endoscope-assisted hairline technique is not frequently employed in head and neck surgery. The evolution of the hairline surgical approach has been influenced by changes in disease conditions and recent advances in surgical tools. This review article discusses the use of endoscope-assisted hairline approaches in the resection of head and neck masses, focusing on the surgical procedure and postoperative clinical outcomes.

Electrochemical lipolysis of subcutaneous adipose tissue in a porcine animal model.

OBJECTIVES: There is a considerable demand for noninvasive low-cost fat reduction methods with fewer side effects and shorter recovery times. This study aims to develop a fat-reduction method through electrochemical lipolysis of subcutaneous adipocytes using needle-based electrodes, body tissue fluids, and electrical current application. METHODS: Electrochemical lipolysis was performed by inserting a 4-pin needle electrode connected to a DC power supply into the pig's abdomen. Applied electrical current (0.5 and 1 mA) and treatment time (5 or 10 minutes) were varied systematically. Ultrasound imaging was performed before and after treatment to determine changes in fat thickness. Tissue samples were collected at 0, 2, and 4 weeks posttreatment for histological evaluation to determine the mechanism of action and the procedure's efficacy. RESULTS: Electrochemical subcutaneous adipose tissue lipolysis in a porcine model was achieved through hydrolysis of physiologic fluid within the vicinity of the inserted electrode where an electric current is applied, leading to localized disruption of fat cell membranes and necrosis. Electric current configuration 1.0 mA showed more pronounced lipolysis effects applied for 10 minutes, significantly decreasing adipocyte content per treatment area. The electrochemical treatment method also stimulates collagen synthesis, which helps reduce fat. CONCLUSIONS: Electrochemical lipolysis is a potential new noninvasive localized technique to reduce fat. The treatment method induces fat cell necrosis via in situ reduction-oxidation reaction by the electrochemical activation of physiologic fluid in the surrounding tissue. Electrochemical lipolysis is a simple, low-cost, fat-reducing treatment method without harmful side effects.

Analysis of penetration depth and healing process of a needleless laser lancet using swept-source optical coherence tomography.

BACKGROUND AND OBJECTIVES: Needleless laser lancets have been used to reduce needle pain in people who undertake self-monitoring of blood glucose (SMBG). Although clinical trials have been conducted to understand the degree of pain associated with the developed laser blood sampling device, it is only judged by the patients' subjective judgment. This study aimed to analyze the performance and healing process of a needleless laser lancet. In particular, the penetration depth and healing process of a conventional lancet and a needleless laser lancet were quantitatively analyzed using a swept-source optical coherence tomography (SS-OCT) system. MATERIALS AND METHODS: To reduce unnecessary animal sacrifice, pig skin was used to establish and set the conditions for needleless laser lancets (wavelength of 2.94 µm; LMT-5000; Lameditech), and the penetration depth and healing process were quantitatively assessed at 0, 6, 9, and 16 h after laser (energy, 150-270 mJ in stages; voltage, 7.4 Vdc ; pulse width, approximately 200 microsecond) irradiation using 7-week-old male BALB/c nude mice. The penetration depth and healing process were measured using homemade SS-OCT, and histopathological examination was performed to observe the healing process. RESULTS: Four 7-week-old male BALB/c nude mice were tested at intensity levels of 1-3 using a needleless laser lancet and compared with the experimental values using a conventional lancet. After the lancet test, the diameter and depth of the puncture were measured using SS-OCT and the healing process was confirmed using SS-OCT and pathological slides. The puncture diameter of the needleless laser lancet was about 0.5 mm regardless of the level. In addition, the average depths at Levels 1, 2, and 3 of the measured needleless laser lancet were approximately 1.05, 1.18, and 1.52 mm, respectively, and the last common lancet was approximately 0.9 mm. In addition, the healing process of the needleless laser lancet and conventional lancet was confirmed through the SS-OCT system. CONCLUSION: After using the needleless laser lancet, quantitative indicators such as the diameter of puncture, penetration depth, and healing process were confirmed through two-dimensional and three-dimensional images of the homemade SS-OCT system and microscopic imaging of pathological slides.

Trimethyl chitosan postoperative irrigation solution modulates inflammatory cytokines related to adhesion formation.

Lavage or irrigation has been instilled in surgical practice for wound clearance and surgical site infection prevention during and after surgery. Herein, we developed a new irrigation solution using trimethyl chitosan (TMC), a quaternized chitosan derivative. The TMC-saline irrigation solution developed in the study possesses highly effective bactericidal properties with hemostatic and anti-adhesion properties. The anti-adhesion property of TMC was investigated in relation to inflammatory cytokine response and wound healing. TMC-saline irrigation solution showed reduced pro-inflammatory cytokine protein and gene expressions relevant in the cascade of wound healing and cytokine-related orchestration of postoperative adhesion formation. Further development of this multifunctional TMC-saline irrigation solution can be beneficial for surgical applications and postoperative wound management.

Improved healing and macrophage polarization in oral ulcers treated with photobiomodulation (PBM).

OBJECTIVES: The effect of photobiomodulation (PBM) treatment on wound healing and macrophage polarization was investigated in vivo. Animal models of oral ulcers were simulated through chemically induced oral ulcers in rats. MATERIALS AND METHODS: PBM treatment using an infrared pulsed laser was used to treat oral ulcers in the animal models. Twelve Sprague-Dawley rats were randomly divided into four groups depending on set absorbed energy: Group 1 (control), Group 2 (30 J), Group 3 (60 J), and Group 4 (100 J). Laser treatment was performed every other day for 8 days after ulcer confirmation. Parameters used were as follows: wavelength 808 nm, power output 50 mW, spot size 10 mm, frequency 10 Hz, and pulse duration 1 millisecond. Ulcers were measured to determine the effect of the treatments over time. Histology, immunostaining, and real-time polymerase chain reaction analyses were performed to evaluate the effect of PBM treatment on macrophage-related (IL-6/IL-10) and wound-healing-related (TNF-α/TGF-ß/MMP-2) cytokine expression. RESULTS: Histological examinations indicate that the PBM treatment stimulated a higher level of wound recovery after 8 days of treatment at 60 J absorbed energy compared to other treatment groups. Analyses of relative gene expression of proinflammatory, anti-inflammatory, and tissue remodeling cytokines indicate that the macrophages in the tissue samples were predominantly characterized as M2 subtypes (alternatively activated), which possibly accounts for the accelerated tissue repair in the animal model of oral ulcer. CONCLUSION: This preliminary study stands as a proof of concept regarding the potential use of infrared laser PBM treatment for oral ulcers which have not been previously investigated upon. PBM treatment affects macrophage polarization and enhances wound healing. Further experimentation will be conducted to expand the understanding of how PBM treatment affects the healing mechanism of ulcers.

Role of Transient Receptor Potential Vanilloid 1 in Sonic Hedgehog-Dependent Taste Bud Differentiation.

Taste bud cell differentiation is extremely important for taste sensation. Immature taste bud cells cannot function during taste perception transmission to the nerve. In this study, we investigated whether hedgehog signaling affected taste bud cell differentiation and whether transient receptor potential vanilloid 1 (TRPV1) played a key role in dry mouth. The induction of dry mouth due to salivary gland resection (SGR) was confirmed on the basis of reduced salivation and disrupted fungiform papillae. The expression of keratin 8 (K8) of taste bud cells, neurofilament (NF), sonic hedgehog (Shh), and glioma-associated oncogene homolog 1 (Gli1) around taste bud cells was downregulated; however, the expression of TRPV1, P2X purinoceptor 3 (P2X3), and hematopoietic stem cell factor (c-Kit) was upregulated at the NF ends in the dry mouth group. To investigate the effect of TRPV1 defect on dry mouth, we induced dry mouth in the TRPV-/- group. The K8, NF, and P2X3 expression patterns were the same in the TRPV1 wild-type and TRPV1-/- dry mouth groups. However, Shh and c-Kit expression decreased regardless of dry mouth in the case of TRPV1 deficiency. These results indicated that TRPV1 positively regulated proliferation during taste bud cell injury by blocking the Shh/Gli1 pathway. In addition, not only cell proliferation but also differentiation of taste bud cells could not be regulated under TRPV1-deficiency conditions. Thus, TRPV1 positively regulates taste bud cell innervation and differentiation; this finding could be valuable in the clinical treatment of dry mouth-related taste dysfunction.

Endoscopically-Assisted Scar-Free Midline Neck Mass Excision.

Traditional open surgery is indicated for the treatment of selected tumor subsites in the head and neck. However, it can cause major cosmetic problems and functional pathologies. The endoscopically-assisted transoral approach is increasingly preferred in some surgical fields due to its superior cosmetic and functional outcomes. Nonetheless, endoscopically-assisted transoral approach is not yet standard in the head and neck due to their anatomical complexity. The transoral surgical approach has been used for head and neck masses since the 1960s, and its application continues to evolve with changing disease conditions and recent innovations in surgical instruments. The potential for wide application of transoral surgery continues to be investigated, with a focus on minimizing occurrence of the complications. This review presents details of the surgical procedure and postoperative clinical outcomes, as well as endoscopically-assisted scar-free techniques for the resection of midline neck masses.

Effect of TSH Suppression Therapy on Bone Mineral Density in Differentiated Thyroid Cancer: A Systematic Review and Meta-analysis.

CONTEXT: Because subclinical hyperthyroidism increases the risk of osteoporosis and fractures, concerns are growing about the long-term skeletal safety of TSH suppression therapy after total thyroidectomy in patients with differentiated thyroid cancer (DTC). OBJECTIVE: We aimed to determine the effect of TSH suppression therapy on bone mineral density (BMD) in DTC patients. METHODS: We searched PubMed, Embase, the Cochrane library, and other sources. Eligible observational studies included DTC patients who underwent TSH suppression therapy and BMD measurement. Two independent reviewers extracted data on the studies' characteristics and outcomes and determined their risk of bias. Data were extracted from each study for postmenopausal/premenopausal women's and men's lumbar spine (LS), femoral neck (FN), and total hip (TH) BMD and summed using a random-effects meta-analysis model. The weighted mean differences with 95% CIs are expressed for the differences in outcome measurements between groups. RESULTS: Seventeen studies (739 patients and 1085 controls) were included for quantitative analysis. In postmenopausal women, TSH suppression therapy showed a significant decrease in LS BMD (-0.03; -0.05, -0.02), and a similar trend was seen in TH. In premenopausal women, TSH suppression therapy significantly increased LS BMD (0.04; 0.02, 0.06) and FN BMD (0.02; 0.01, 0.04). In men, there was no significant association between TSH suppression therapy and BMD at any site compared with the controls. CONCLUSION: Evidence from observational studies suggests that postmenopausal women treated with TSH suppression therapy are at risk for lower BMD. Attention should be paid to long-term skeletal safety in DTC survivors.

Effect of Photobiomodulation on Restoration of Ionization Radiation-Induced Thyroid Dysfunction Through p53 and Retinoblastoma Signaling.

Objective: This study aimed to investigate whether photobiomodulation (PBM) restores normal thyroid follicular cells affected by ionizing radiation, and to determine the mechanism of PBM on thyroid function. Background: Despite diverse applications of PBM to medical therapy, there has been no evidence of its involvement with thyroid function. Methods: A light emission diode (850 nm) array was used at 2, 5, and 10 J/cm2 for in vitro analysis in human thyroid N-Thy-3.1 cells, and at 120 J/cm2 for in vivo analysis in C58BL6 mice. Cell survival and proliferation were evaluated through clonogenic and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] assays. Cell cycle was measured using flow cytometry. Cell cycle markers, such as p53, retinoblastoma (Rb), and E2F1, were investigated by western blot analysis. In vitro levels of cyclic adenosine monophosphate (cAMP) and thyroglobulin (TG) and in vivo levels of cAMP, TG, thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) were measured using enzyme-linked immunosorbent assay. Results: A lethal dose for N-Thy-3.1 cells was 6 Gy. PBM at 2 J/cm2 was the most effective for causing cell cycle arrest by ionizing radiation. PBM regulated p53, Rb, and cAMP expression levels in vitro. PBM restored proliferation by regulating Rb and p53 in ionizing radiated thyroid follicular tissues. PBM also recovered cAMP, TG, and thyroid function marker expression (TSH, T3, and T4) by ionizing radiation in vivo. Conclusions: PBM restored ionizing radiation-induced thyroid follicular cell dysfunction by increasing cAMP proliferation and expression. PBM is effective for ionizing radiation-induced hypothyroidism by complementing cell proliferation and cAMP, presenting a novel method for clinical application.

Biochemical and Pain Comparisons Between the Laser Lancing Device and Needle Lancets for Capillary Blood Sampling: A Randomized Control Trial.

BACKGROUND AND OBJECTIVES: Patients around the world use a lancing device to perform self-monitoring of blood sugar (SMBG). However, there are always fears of needles and pain. Therefore, less painful devices are being developed. The purpose of this study was to compare the usefulness and safety of a laser lancing device (without a needle) to a conventional needle lancet (with a needle) for capillary blood sampling. STUDY DESIGN/MATERIALS AND METHODS: A total of 40 healthy subjects were enrolled in the study. Capillary blood was collected from a laser lancing device (without a needle) and a conventional needle lancet (with a needle) on opposite fingers, the choice of which was randomly selected. The laser lancing device (LMT-3000) uses a 2940 nm mono-pulse laser, a radiation field of 350 µm, laser energy of 210 mJ, and a 3.7 V battery. One week later, capillary blood was obtained by switching the devices and fingers. The biochemical measurements and pain were compared between the two groups. Puncture pain was measured on a pain scale from 0 to 10. RESULT: All patients were tested with both a laser lancing device and a conventional needle lancet. In the biochemical analysis, the blood glucose level was 103.21 ± 17.20 mg/dl in laser lancing device group and 102.25 ± 22.44 mg/dl in the conventional needle lancet group, and there were no significant differences between the two groups (P = 0.940). The pH, CO2 , O2 , lactate and hematocrit levels of the blood were no significant differences between the two groups. In the first trial, the median pain score (interquartile range) of patients using laser lancing device was 2.0 (1.0-3.0), whereas it was 2.5 (2.0-4.0) in patients using a conventional needle lancet (P = 0.029). In the second trial, one week later, the median pain score in the laser lancing device group was 2.5 (1.0-4.0), whereas it was 3.5 (2.25-5.0) in the conventional needle lancet group (P = 0.001). The difference in pain scores between the first and second trials was significant in the conventional needle lancet group (P = 0.007), but not in the laser lancing device group (P = 0.150). CONCLUSION: There was no difference in biochemical results between the laser lancing device group and the conventional needle lancet group. The laser lancing device demonstrated comparatively lower pain than the conventional needle lancet. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Survival Benefits From Surgery for Stage IVa Head and Neck Squamous Cell Carcinoma: A Multi-institutional Analysis of 1,033 Cases.

OBJECTIVES: Head and neck squamous cell carcinomas (HNSCs) are frequently diagnosed at the locoregional advanced stage (stage IVa), but controversy remains regarding whether stage IVa HSNCs should be treated with upfront surgery or definitive chemoradiation therapy (CRT). The purpose of this study was to compare overall survival (OS) and disease-free survival (DFS) in patients with stage IVa HNSC treated primarily by surgery with curative intent with/without (neo)adjuvant treatment (surgery group) versus those treated primarily with CRT (CRT group). METHODS: We reviewed data of 1,033 patients with stage IVa HNSC treated with curative intent at 17 cancer centers between 2010 and 2016. RESULTS: Among 1,033 patients, 765 (74.1%) received upfront surgery and 268 (25.9%) received CRT. The 5-year OS and DFS rates were 64.4% and 62.0% in the surgery group and 49.5% and 45.4% in the CRT group, respectively. In multivariate analyses, OS and DFS were better in the surgery group than in the CRT group (odds ratio [OR] for death, 0.762; 95% confidence interval [CI], 0.592-0.981; OR for recurrence, 0.628; 95% CI, 0.492-0.802). In subgroup analyses, the OS and DFS of patients with oropharyngeal cancer were better in the surgery group (OR for death, 0.548; 95% CI, 0.341-0.879; OR for recurrence, 0.598; 95% CI, 0.377-0.948). In the surgery group, patients with laryngeal cancer showed better OS (OR for death, 0.432; 95% CI, 0.211-0.882), while those with hypopharyngeal cancer DFS was improved (OR for recurrence, 0.506; 95% CI, 0.328-0.780). CONCLUSION: A survival benefit from surgery may be achieved even in patients with stage IVa HNSC, particularly those with oropharyngeal and laryngeal cancer. Surgery led to a reduction in the recurrence rate in patients with hypopharyngeal cancer.

Protective Effect of Alpha-Lipoic Acid on Salivary Dysfunction in a Mouse Model of Radioiodine Therapy-Induced Sialoadenitis.

Radioiodine (RI) therapy is known to cause salivary gland (SG) dysfunction. The effects of antioxidants on RI-induced SG damage have not been well described. This study was performed to investigate the radioprotective effects of alpha lipoic acid (ALA) administered prior to RI therapy in a mouse model of RI-induced sialadenitis. Four-week-old female C57BL/6 mice were divided into four groups (n = 10 per group): group I, normal control; group II, ALA alone (100 mg/kg); group III, RI alone (0.01 mCi/g body weight, orally); and group IV, ALA + RI (ALA at 100 mg/kg, 24 h and 30 min before RI exposure at 0.01 mCi/g body weight). The animals in these groups were divided into two subgroups and euthanized at 30 or 90 days post-RI treatment. Changes in salivary 99mTc pertechnetate uptake and excretion were tracked by single-photon emission computed tomography. Salivary histological examinations and TUNEL assays were performed. The 99mTc pertechnetate excretion level recovered in the ALA treatment group. Salivary epithelial (aquaporin 5) cells of the ALA + RI group were protected from RI damage. The ALA + RI group exhibited more mucin-containing parenchyma and less fibrotic tissues than the RI only group. Fewer apoptotic cells were observed in the ALA + RI group compared to the RI only group. Pretreatment with ALA before RI therapy is potentially beneficial in protecting against RI-induced salivary dysfunction.

Alpha-Lipoic Acid Ameliorates Radiation-Induced Salivary Gland Injury by Preserving Parasympathetic Innervation in Rats.

Radiation therapy is a standard treatment for patients with head and neck cancer. However, radiation exposure to the head and neck induces salivary gland (SG) dysfunction. Alpha lipoic acid (ALA) has been reported to reduce radiation-induced toxicity in normal tissues. In this study, we investigated the effect of ALA on radiation-induced SG dysfunction. Male Sprague-Dawley rats were assigned to the following treatment groups: control, ALA only (100 mg/kg, intraperitoneally), irradiation only, and ALA administration 24 h or 30 min prior to irradiation. The neck area, including SGs, was irradiated evenly at 2 Gy/min (total dose, 18 Gy) using a photon 6 MV linear accelerator. The rats were sacrificed at 2, 6, 8, and 12 weeks after irradiation. Radiation decreased SG weight, saliva secretion, AQP5 expression, parasympathetic innervation (GFRα2 and AchE expression), regeneration potentials (Shh and Ptch expression), salivary trophic factor levels (brain-derived neurotrophic factor and neurturin), and stem cell expression (Sca-1). These features were restored by treatment with ALA. This study demonstrated that ALA can rescue radiation-induced hyposalivation by preserving parasympathetic innervation and regenerative potentials.

Anatomical study of gasless transoral thyroidectomy and clinical application.

BACKGROUND: Transoral thyroidectomy is becoming a preferred technique because it has the advantage of not leaving a scar after surgery. However, it is not yet standard because of the anatomic nerve complexity of this oral cavity and difficulty of approach. The aim of this study was to determine the safety zone of a gasless transoral thyroidectomy approach using an anatomical study and to evaluate the efficacy of this approach on clinical application. METHODS: Phase 1, twenty unilateral specimens from fresh cadavers underwent staining by the modified Sihler's method to identify nerves around the oral vestibules. Then, the safety zone of the transoral thyroidectomy approach was proposed. Phase 2, a comparative analysis of the clinical outcomes of gasless transoral thyroidectomy through the safety zone versus transcutaneous thyroidectomy approach. RESULTS: In phase 1, numerous inferior labial branches diverged from the mental nerve and were distributed across the lower lip. In most cases, the most lateral branch reached almost to the corner of the mouth, whereas a nerve-free area was present at the medial region of the lower lip. The suggested safety zone was presented as a trapezoid shape. In phase 2, there were no significant differences in age, mass size, or complications between the two groups. However, the operation time in the transoral thyroidectomy group was longer than in the transcutaneous group (p = 0.001). CONCLUSIONS: Based on the anatomical study, we suggested a safety zone for the gasless transoral thyroidectomy. On application of this safety zone, gasless transoral thyroidectomy is a safe and feasible procedure.

Endoscope-assisted hairline approach for resecting maxillofacial masses.

The endoscope-assisted hairline approach is becoming a preferred technique in several surgical disciplines because of its advantage of good cosmetic outcomes. However, such operations are not yet standard for benign lesions in the maxillofacial area due to the anatomical complexity of this region. This study describes an endoscope-assisted technique for resecting benign lesions in the maxillofacial area via a hairline approach. The clinical outcomes with this approach were compared to those obtained with the conventional transcutaneous approach. Benign maxillofacial lesions were excised via endoscope-assisted hairline approach in 27 patients and via transcutaneous approach in 28 patients. Clinical outcomes and complications related to the procedures were evaluated; the primary outcome was the efficacy of the procedure and the secondary outcome was cosmetic satisfaction. There were no significant differences with respect to overall demographic characteristics between the groups, although the operation time was longer for the hairline approach (P=0.001). Cosmetic satisfaction showed much better results for the hairline approach (P=0.001). Endoscope-assisted excision of benign maxillofacial lesions via the hairline approach is a feasible method with excellent cosmetic results.

Endoscope-assisted transoral accessory parotid mass excision: Multicenter prospective observational study.

OBJECTIVE: Transoral surgery is gaining favor because it has the advantage of leaving no scar after surgery. The aim of this study was to evaluate the technical feasibility and safety of endoscope-assisted transoral accessory parotid mass excision. STUDY DESIGN: Multicenter, prospective, observational study. METHODS: This study was designed as a 7-year, prospective, multicenter evaluation of endoscope-assisted transoral accessory parotid mass excision. Clinical outcomes and complications related to the procedures were evaluated in patients. RESULTS: Twenty patients underwent endoscope-assisted transoral accessory parotid mass excisions, and 22 patients underwent conventional parotidectomy approach excisions. There was no significant difference with respect to overall demographic characteristics between the groups. However, the operation times were shorter in the transoral approach group (P = 0.001), and cosmetic satisfaction was much better in the transoral group (P < 0.001). CONCLUSION: Endoscope-assisted transoral accessory parotid mass excision is a potentially safe and effective procedure with excellent outcomes. LEVEL OF EVIDENCE: 2 Laryngoscope, 130:1218-1226, 2020.

Alpha-Lipoic Acid Ameliorates Radiation-Induced Lacrimal Gland Injury through NFAT5-Dependent Signaling.

Dry eye syndrome related to radiation therapy is relatively common and can severely impair a patient's daily life. The nuclear factor of activated T cells 5(NFAT5) is well known for its osmoprotective effect under hyperosmolar conditions, and it also has immune-modulating functions. We investigated the role of NFAT5 and the protective effect of α-lipoic acid(ALA) on radiation-induced lacrimal gland (LG) injuries. Rats were assigned to control, ALA only, radiation only, and ALA administered prior to irradiation groups. The head and neck area, including the LG, was evenly irradiated with 2 Gy/minute using a photon 6-MV linear accelerator. NFAT5 expression was enhanced and localized in the LG tissue after irradiation and was related to cellular apoptosis. ALA had a protective effect on radiation-induced LG injury through the inhibition of NFAT5 expression and NFAT5-dependent signaling pathways. Functional radiation-induced damage of the LG and cornea was also restored with ALA treatment. NFAT5 expression and its dependent signaling pathways were deeply related to radiation-induced dry eye, and the condition was improved by ALA treatment. Our results suggest a potential role of NFAT5 and NF-κB in the proinflammatory effect in LGs and cornea, which offers a target for new therapies to treat dry eye syndrome.