Chlorine-Induced Toxicity on Murine Cornea: Exploring the Potential Therapeutic Role of Antioxidants.

Chlorine (Cl2) exposure poses a significant risk to ocular health, with the cornea being particularly susceptible to its corrosive effects. Antioxidants, known for their ability to neutralize reactive oxygen species (ROS) and alleviate oxidative stress, were explored as potential therapeutic agents to counteract chlorine-induced damage. In vitro experiments using human corneal epithelial cells showed decreased cell viability by chlorine-induced ROS production, which was reversed by antioxidant incubation. The mitochondrial membrane potential decreased due to both low and high doses of Cl2 exposure; however, it was recovered through antioxidants. The wound scratch assay showed that antioxidants mitigated impaired wound healing after Cl2 exposure. In vivo and ex vivo, after Cl2 exposure, increased corneal fluorescein staining indicates damaged corneal epithelial and stromal layers of mice cornea. Likewise, Cl2 exposure in human ex vivo corneas led to corneal injury characterized by epithelial fluorescein staining and epithelial erosion. However, antioxidants protected Cl2-induced damage. These results highlight the effects of Cl2 on corneal cells using in vitro, ex vivo, and in vivo models while also underscoring the potential of antioxidants, such as vitamin A, vitamin C, resveratrol, and melatonin, as protective agents against acute chlorine toxicity-induced corneal injury. Further investigation is needed to confirm the antioxidants' capacity to alleviate oxidative stress and enhance the corneal healing process.

Wound-Healing Effects of Mesenchymal Stromal Cell Secretome in the Cornea and the Role of Exosomes.

Mesenchymal stromal/stem cells (MSCs) and their secreted factors have been shown to have immunomodulatory and regenerative effects. In this study, we investigated human bone-marrow-derived MSC secretome (MSC-S) for the treatment of corneal epithelial wounds. Specifically, we evaluated the role of MSC extracellular vesicles (EV)/exosomes in mediating the wound-healing effects of the MSC-S. In vitro studies using human corneal epithelial cells showed that MSC-CM increased cell proliferation in HCEC and HCLE cells, while EV-depleted MSC-CM showed lower cell proliferation in both cell lines compared to the MSC-CM group. In vitro and in vivo experiments revealed that 1X MSC-S consistently promoted wound healing more effectively than 0.5X MSC-S, and MSC-CM promoted wound healing in a dose-dependent manner, while exosome deprivation delayed wound healing. We further evaluated the incubation period of MSC-CM on corneal wound healing and showed that MSC-S collected for 72 h is more effective than MSC-S collected for 48 h. Finally, we evaluated the stability of MSC-S under different storage conditions and found that after one cycle of freeze-thawing, MSC-S is stable at 4 °C for up to 4 weeks. Collectively, we identified the following: (i) MSC-EV/Exo as the active ingredient in MSC-S that mediates the wound-healing effects in the corneal epithelium, providing a measure to optimize its dosing for a potential clinical product; (ii) Treatment with EV/Exo-containing MSC-S resulted in an improved corneal barrier and decreased corneal haze/edema relative to EV/Exo-depleted MSC-S; (iii) The stability of MSC-CM for up to 4 weeks showed that the regular storage condition did not significantly impact its stability and therapeutic functions.

Therapeutic Potential of Mesenchymal Stem Cell-Secreted Factors on Delay in Corneal Wound Healing by Nitrogen Mustard.

Ocular surface exposure to nitrogen mustard (NM) leads to severe ocular toxicity which includes the separation of epithelial and stromal layers, loss of endothelial cells, cell death, and severe loss of tissue function. No definitive treatment for mustard gas-induced ocular surface disorders is currently available. The research was conducted to investigate the therapeutic potential of mesenchymal stem cell-conditioned media (MSC-CM) in NM-induced corneal wounds. NM was added to different types of corneal cells, the ocular surface of porcine, and the ocular surface of mice, followed by MSC-CM treatment. NM significantly induced apoptotic cell death, cellular ROS (Reactive oxygen species), and reduced cell viability, metabolic gene expression, and mitochondrial function, and, in turn, delayed wound healing. The application of MSC-CM post NM exposure partially restored mitochondrial function and decreased intracellular ROS generation which promoted cell survival. MSC-CM therapy enhanced wound healing process. MSC-CM inhibited NM-induced apoptotic cell death in murine and porcine corneal tissue. The application of MSC-CM following a chemical insult led to significant improvements in the preservation of corneal structure and wound healing. In vitro, ex vivo, and in vivo results suggest that MSC-CM can potentially provide targeted therapy for the treatment of chemical eye injuries, including mustard gas keratopathy (MGK) which presents with significant loss of vision alongside numerous corneal pathologies.

Aspirin Exacerbated Respiratory Disease and Nasal Polyp Phenotyping.

Aspirin exacerbated respiratory disease (AERD) is known by the triad of chronic rhinosinusitis with nasal polyposis (CRSwNP), aspirin hypersensitivity, and asthma, but its etiology and physiopathogenesis are still unclear. This cross-sectional study was designed to investigate allergy and inflammatory cells (neutrophils vs. eosinophils) dominancy in nasal polyp tissue of patients with AERD compared to non-AERD patients. CRSwNP patients scheduled for endoscopic sinus surgery were recruited in this study. Nasal polyp tissue was analyzed for infiltrating cells, and Eosinophil dominant and neutrophil dominant polyps were determined. AERD was confirmed by oral aspirin challenge (OAC). Demographics data; history of asthma, exacerbation by using NSAIDs, routine use of aspirin, type of surgery (primary or revision), and results of skin prick test and spirometry were recorded. Pathology results and contributing factors compared between AERD and non-AERD patients. Sixty-five patients (39 women, 26 men) were enrolled in the study (mean age 38.83 ± 12.43 years). Thirty (46%) patients had positive OAC tests. Totally 41 patients (63.1%) had eosinophilic polyps. 80% of patients with eosinophilic polyp had positive OAC and were AERD (P < 0.05). There was no significant difference in demographics, revision surgery, and concomitant asthma between AERD and non-AERD groups (P > 0.05). The positive skin prick test was higher in AERD and also in eosinophilic polyp patients, but it was not statistically significant (P = 0.086 and P = 0.177). Eosinophilic polyps are more common in AERD. A positive skin prick test is associated with AERD and eosinophilic polyp.

Effects of Steroids and Curcumin on Prevention of Laryngeal Stenosis Secondary to Trauma.

INTRODUCTION: The aim of this study was to compare the preventive effects of corticosteroids and curcumin on subglottic stenosis in an animal model. MATERIALS AND METHODS: Twenty-one male German Shepherd dogs were used for this study. After standardized trauma to the subglottic area, the dogs were divided into three groups. Group A received curcumin (450 mg/ day) for 15 days; Group B received beclomethasone (2 puffs/day, 50 µg/dose) for 15 days; Group C received saline spray only. At 6 weeks after the injury, the larynx specimens were examined histopathologically to assess epithelialization, inflammation, and fibrosis. RESULTS: Complete epithelial covering of the steroid-treated group was significantly less than that of the control group. Despite inflammation and fibrosis, there was no significant difference between the steroid and control groups. In the curcumin-treated group, there was no significant difference between the groups. CONCLUSION: Topically applied steroid decreases epithelialization after induced subglottic injury. It is recommended that further studies be conducted in order to investigate the effects of the two drugs on airway stenosis prevention.

Stealth Nanogels of Histinylated Poly Ethyleneimine for Sustained Delivery of Methotrexate in Collagen-Induced Arthritis Model.

PURPOSE: The study aimed to illustrate application of polycation Stealth nanogels for sustained delivery of methotrexate (MTX) in collagen induced arthritis (CIA) model in C57Bl/6 mice. METHODS: Nanogel synthesis involves metal ion coordinated self-assembly of PEGylated poly ethyleneimine (L-histidine substituted), chemical crosslinking and subsequent removal of the coordinated metal. The nanogels were characterized by TEM and DLS-zeta potential. Comparative efficacy and pharmacokinetics of the i.v. administred MTX-loaded nanogels were investigated in the CIA model. Inflammation site passive accumulation of the fluorophore-labeled nanogels was tested using in-vivo imaging of mice paw received unilateral injection of lipopolysaccharide. RESULTS: Uniform nanogels (sizes ~40 nm by TEM) were loaded with MTX (entrapment efficiency = 62% and drug loading = 54% at the MTX feeding ratio of 0.3 relative to total molar concentration of the polymer amines). The nanogels exhibited neutral surface charge and an acceptable biocompatibility in terms of albumin aggregation, hemolysis, erythrocyte aggregation and cytotoxicity. Single dose pharmacokinetics of the MTX-loaded nanogels, unlike free drug, showed a sustained plasma profile. When arthritis established as confirmed by histopathology, a remarkable decline of paw swelling and clinical scores was observed. Fluorescence intensity of the nanogels was enhanced about 2.7 folds at the inflamed than control normal ankle. CONCLUSION: Sustained delivery of MTX and preferential accumulation of the nanogels in inflamed paw might explain the superior clinical outcome of the MTX-loaded nanogels.

Increased mast cell counts in benign and malignant salivary gland tumors.

Background and aims. Mast cells are one of the characteristic factors in angiogenesis, growth, and metastatic spread of tumors. The distribution and significance of mast cells in many tumors have been demonstrated. However, few studies have evaluated mast cell infiltration in salivary gland tumors. In this study, mast cell counts were evaluated in benign and malig-nant salivary gland tumors. Materials and methods. This descriptive and cross-sectional study assessed 30 cases of pleomorphic adenoma, 13 cases of adenoid cystic carcinoma, 7 cases of mucoepidermoid carcinoma (diagnosed on the basis of 2005 WHO classifica-tion), with adequate stroma in peritumoral and intratumoral areas, and 10 cases of normal salivary glands. The samples were stained with 5% diluted Giemsa solution and the average stained cell counts were calculated in 10 random microscopic fields in peri- and intra-tumoral areas. Data were analyzed by t-test and Mann-Whitney and Krusskal-Wallis tests. Results. The average mast cell counts increased in the tumors compared to normal salivary glands. There was no signifi-cant difference between benign and malignant tumors and also between different malignant tumors. Infiltration was signifi-cantly denser in peri-tumoral stroma in both tumoral groups (P = 0.001). Minor salivary glands contained significantly more numerous mast cells. Conclusion. Although mast cell counts increased in benign and malignant salivary gland tumors, there were no signifi-cant differences between the tumoral groups. Further studies are suggested to determine the type of these cells which might be useful in the assessment of biological nature of the tumor and its future treatment modality.

Salivary gland tumors: a clinicopathologic study of 366 cases in southern Iran.

BACKGROUND: Salivary gland tumors (SGT) are one of the most complex human neoplasms, demonstrating variations in their clinicopathological profile related to racial and geographic differences. Few studies with large samples have been reported in Iran. We here investigated a large group of patients in southern Iran. MATERIALS AND METHODS: In this retrospective study, all cases of primary epithelial salivary gland tumors, which had been recorded in a 5 years period from 2005-2009, were enrolled. Clinical data such as histopathologic type and site of the lesion as well as patients' age and gender were analyzed. RESULTS: Data of 366 cases of SGTs were recorded. Pleomorphic adenoma (80.2%) and adenoid cystic carcinoma (46.6%) were the most common benign and malignant neoplasms. Male to female ratio (M/F) and the mean age of patients were 1:1.05 and 37.7 for benign tumors while they were 1.2:1 and 50.6 for malignant tumors, respectively. Parotid and minor salivary glands were involved more frequently. CONCLUSIONS: Although the salivary gland tumours encountered were similar in most of their characteristics to those reported in other countries, some differences such as relative frequency and age and gender prevalence were discovered. These findings should help surgeons and pathologists for more accurate diagnosis, management and treatment.

A clinico-pathologic study of 142 orofacial tumors in children and adolescents in southern iran.

OBJECTIVE: The prevalence, patients' age and sex and the site of the lesions are important factors for diagnosis and they may be different in various populations. The aim of this study was to determine the type and distribution of orofacial tumors among children and adolescents in an Iranian population METHODS: In this retrospective, case series study, data about the type, age, sex and site of 142 tumors in patients ≤18 years afflicted with orofacial neoplasms referred 2005-2009 to two referral centers in Shiraz, Southern Iran, were collected and analyzed. FINDINGS: There were 142 (2.8%) tumors among the subjects. The most common types of benign and malignant tumors were odontoma and lymphoma in children and pleomorphic adenoma and rhabdomyosarcoma in adolescents. Parotid and posterior parts of the mandible were the most common sites of soft tissue and intrabony tumors. In the oral cavity, the palate was the most common affected site. The tumors were found in boys with higher frequency (Male:Female ratio was 1.4:1). CONCLUSION: The observed differences in tumor type and distribution in comparison with previous studies may be attributed to genetic and geographic variations in the populations; however the design and methods of the studies are different, too.