Developing a model for aqueous deficient dry eye secondary to periglandular cicatrizing conjunctivitis.

PURPOSE: The current study used various techniques to develop a rabbit animal model of lacrimal gland damage caused by scarring conjunctivitis in the periglandular area. METHODS: Left eyes of New Zealand white rabbits were injected with 0.1 ml of 1M NaOH subconjunctivally around superior and inferior lacrimal gland orifices (Group 1, n = 4), touched with 1M NaOH for 100 s to the superior and inferior fornices with conjunctival denuding (Group 2; n = 4), and electrocauterization to the ductal opening area (Group 3; n = 4). The ocular surface staining, Schirmer I, lacrimal gland, and conjunctival changes were observed at baseline,1, 4, 8, and 12 weeks. The degree of glandular inflammation, conjunctival fibrosis (Masson Trichrome), and goblet cell density (PAS) were also assessed. RESULTS: At 12 weeks, the lacrimal glands of group 1 rabbits with periglandular injection showed severe inflammation with mean four foci/10HPF and a significant mean reduction in the Schirmer values by 7.6 mm (P = 0.007). Lacrimal glands had diffuse acinar atrophy, loss of myoepithelial cells, and ductular dilatation. The overlying conjunctiva showed fibrosis, goblet cell loss, and corneal vascularization in the inferotemporal quadrant. No lacrimal gland or ocular surface changes were observed in groups 2 and 3 at 12 weeks, except for localized subconjunctival fibrosis. CONCLUSION: Periglandular injection of 0.1 ml of 1M NaOH induced extensive lacrimal gland damage with reduced secretion and scarring in the subconjunctival plane compared to direct cauterization or direct NaOH contact to the ductal orifices of the rabbit lacrimal gland.

Evaluation of the effectiveness of mother milk exosomes in the experimental corrosive esophagitis model.

PURPOSE: We aimed to examine the effectiveness of mother milk exosomes in treating corrosive esophageal burns. MATERIALS AND METHODS: 32 rats were separated into four equal groups and weighed individually before the procedure. A corrosive esophageal burn model was created with 12.5% sodium hydroxide by a 3F Fogarty catheter. Group 1 did not apply any process or treatment, Group 2 was burned, and no treatment was performed. Group 3 was burned, and then 0.5 cc/day of mother milk exosome extract was given. Group 4 was not applied any process, and 0.5 cc/day mother milk exosome extract was given. All rats were weighed again and sacrificed. Biopsy samples were sent to the pathology laboratory for histopathological examination (in terms of inflammation, fibrosis, and necrosis).Kindly check and confrm all email ids.The e-mail addresses and affiliation of all authors were checked. Affiliation departments are as stated on the title page. There is no change. RESULTS: A significant difference was found in the results of inflammation and fibrosis. There was a meaningful difference in fibrosis between the 2nd and 3rd groups. There was weight gain in groups 1, 3 and 4. Statistical evaluations for each group were significant. CONCLUSION: It was observed that breast milk exosomes may be effective in inflammation and fibrosis formation in treating corrosive esophageal burns. This suggested that breast milk exosomes reduce stricture formation due to esophageal corrosion.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [specify authors given name] Last name [specify authors last name]. Also, kindly confirm the details in the metadata are correct.The names and affiliation of all authors were checked. Affiliation departments are as stated on the title page. There is no change. Also we confirm the details in the metadata.

Standardization of corneal alkali burn methodology in rabbits.

Alkali burns are one of the most common injuries used in corneal wound healing studies. Investigators have used different conditions to produce corneal alkali injuries that have varied in sodium hydroxide concentration, application methods, and duration of exposure. A critical factor in the subsequent corneal healing responses, including myofibroblast generation and fibrosis localization, is whether, or not, Descemet's membrane and the endothelium are injured during the initial exposure. After exposures that produce injuries confined to the epithelium and stroma, anterior stromal myofibroblasts and fibrosis are typical, with sparing of the posterior stroma. However, if there is also injury to Descemet's membrane and the endothelium, then myofibroblast generation and fibrosis is noted full corneal thickness, with predilection to the most anterior and most posterior stroma and a tendency for relative sparring of the central stroma that is likely related to the availability of TGF beta from the tears, epithelium, and the aqueous humor. A method is described where a 5 mm diameter circle of Whatman #1 filter paper wetted with only 30 µL of alkali solution is applied for 15 s prior to profuse irrigation in rabbit corneas. When 0.6N, or lower, NaOH is used, then the injury, myofibroblasts, and fibrosis generation are limited to the epithelium and stroma. Use of 0.75N NaOH triggers injury to Descemet's membrane and the corneal endothelium with fibrosis throughout the stroma, but rare corneal neovascularization (CNV) and persistent epithelial defects (PED). Use of 1N NaOH with this method produces greater stromal fibrosis and increased likelihood that CNV and PED will occur in individual corneas.

Concentration-associated pathology of alkali burn in a mouse model using anterior segment optical coherence tomography with angiography.

Pathological features of alkali concentration-associated burn were studied using non-invasive anterior segment optical coherence tomography (AS-OCT) and OCT angiography (OCTA). Alkali burn was induced in C57BL/6J mice (n = 20) by placing filter paper soaked in 0.1, 0.25, 0.5, and 1 M NaOH for 30s on the right eye (left eye control). Longitudinal imaging was performed with AS-OCT/OCTA and fluorescein angiography over 14 days, after which eyes were enucleated at 7 and 14 days for histology and immunofluorescence. Concentration-associated corneal swelling was maximal at 0.5M, increasing linearly in a concentration-dependent fashion at 0.1, 0.25, and 0.5 M NaOH, to levels of 50%, 100%, and 175% of control, respectively. At 0.1M, corneal swelling and surface erosions were prominent, while at 0.25M, deep tissue damage, limbal neovascularization, and stromal haze were evident at 7 days. At 0.5M and 1M, severe exacerbation of the corneal swelling, angle closure, Descemet's membrane detachment, hyphema, and profuse central neovascularization were noted as early as day 3, which further progressed to inflammation, fibrosis, and opacity by day 7. We conclude that alkali concentration-dependent burn intensity biomarkers can be assessed by non-invasive AS-OCT/OCTA, distinguishing between mild, moderate, and severe ocular injury, with potential relevance toward clinical utilization in human eyes.

Strengthened rebamipide ocular nanoformulation to effectively treat corneal alkali burns in mice through the HMGB1 signaling pathway.

Corneal alkali burns are a major ophthalmic emergency, as current therapeutic treatments are limited. Novel treatment targets and new potential agents are required to combat this severe ocular injury. Glycyrrhizin and rebamipide (RBM) are both FDA-approved drugs with potential effects against corneal alkali burns, but RBM is limited by its low aqueous solubility and low bioavailability. This study aimed to utilize dipotassium glycyrrhizinate (DG, a dipotassium salt of glycyrrhizin) as a nanocarrier encapsulating RBM to formulate an ophthalmic solution (marked DG-RBM) with strengthened activities to treat corneal alkali burns. Results showed that an easy DG-RBM preparative process generated particles with high encapsulation efficacy and ultra-small micellar size. The solubility of RBM in DG-RBM in aqueous solution was 3.1 × 105-fold enhanced than its free solution. DG-RBM exhibited excellent storage stability. In vitro cytotoxicity, ex vivo conjunctival responses, and rabbit eye tolerance tests showed that DG-RBM possessed good ocular safety profiles. DG-RBM exhibited improved in vivo corneal permeation profiles and demonstrated a strong effect against H2O2-induced oxidative damage, with a significant effect on promoting epithelial wound healing in corneal cells in vitro. As expected, in a mouse model of corneal alkali burns, the topical administration of DG-RBM achieved a strengthened efficacy against alkali burn damages. The mechanism of this therapeutic effect involved regulating high-mobility group box 1 (HMGB1) signaling and its related angiogenic and proinflammatory cytokines. These findings demonstrate the ease of preparing DG-RBM and its great potential as a novel ocular topical formulation to treat corneal alkali burns by regulating HMGB1 signaling.

Protective effect of bromelain on corrosive burn in rats.

INTRODUCTION: In some cases, the tongue and oesophagus tissues are damaged by the corrosive burn. Surgical interventions may cause scar formation, and severe burns treatment methods are limited. This study aims to investigate bromelain, a phytotherapeutic product, on the corrosive burn as a non-surgical option and as an adjunctive therapy, insofar as the treatment of corrosive wounds is not limited only to the treatment of oxidative stress and inflammatory reactions. METHODS: On the tongues of Wistar albino rats, chemically produced oral ulcers were created by topical application of NaOH (40%) solution, and in the distal oesophagus same mixture was applied to produce a corrosive oesophageal burn. For a week, they were treated orally by bromelain (100 mg/kg/day) or saline solution. At the end of seven days, animals were decapitated to remove the tongue and oesophagus, and blood samples were collected to obtain serum. Myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), interleukin-1 beta (IL-1ß) and tumour necrosis factor-alpha (TNF-α) concentrations were measured in serum, and luminol and lucigenin chemiluminescence (CL) were measured in tissue samples. RESULTS: MDA and CL values were significantly increased, and GSH levels in tissue significantly decreased due to the corrosive burns. Saline treated corrosive burn group measured higher in the serum cytokines in according to the control group. CONCLUSIONS: Bromelain administration decreased oxidant and inflammatory parameters and increased antioxidant levels in NaOH-induced corrosive burns. Thus, we concluded that bromelain may protect the tongue and oesophagus tissues with its anti-inflammatory and antioxidant effects.

Potassium bromate (KBrO3) modulates oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis in Wistar rats.

Potassium bromate (KBrO3) present in consumed ozonised water was recently documented to exacerbate experimental gastric ulcer. Information, however, is vague as regards its effects in the colon where water reabsorption occurs. In this study, we observed the possible effects of KBrO3 on oxidative stress and inflammatory biomarkers in sodium hydroxide (NaOH) - induced Crohn's colitis (CC). Wistar rats (180-200 g) were divided into six groups (n = 10): (i) control; (ii) untreated CC (induced by 1.4% NaOH; intra-rectal administration); and (iii-vi) CC treated with vitamin E, KBrO3, vitamin E+KBrO3, and sulphazalazine, respectively, for 7 days. Body weight and stool score were monitored daily. By day 3 and 7, excised colon was evaluated for ulcer scores and biochemical and histological analysis. Blood samples collected on days 3 and 7 were assayed for haematological indices using standard methods. Data were subjected to analysis of variance (ANOVA) and p ≤ 0.05 considered significant. Platelet/lymphocyte ratio, colonic ulcer score, malondialdehyde, and mast cells were significantly decreased while colonic sulfhydryl, and Ca2+- and Na+/K+-ATPase activities were increased following KBrO3 treatment compared with untreated CC. These findings suggest that KBrO3 may mitigate against NaOH-induced CC via inhibiting mast cell population and oxidative and inflammatory content but stimulating colonic sulfhydryl and Ca2+- and Na+/K+-ATPase activities.

Long term observation of ocular surface alkali burn in rabbit models: Quantitative analysis of corneal haze, vascularity and self-recovery.

Limbal Stem Cell Deficiency (LSCD), caused due to corneal injury, primarily by chemical/alkali burns, leads to compromised vision. Recently, several animal models of corneal alkali burn injury have become available. The majority of the studies with these animal models start interventions soon after the injury. However, in the clinical setting, there is a considerable delay before the intervention is initiated. Detailed knowledge of the molecular, histopathological, and clinical parameters associated with the progression of the injury leading to LSCD is highly desirable. In this context, we set out to investigate clinical, histopathological parameters of ocular surface alkali burn over a long period of time, post-injury. Limbal stem cell-deficient animal models of rabbits were created by alkali burn using sodium hydroxide, which was then assessed for their progression towards LSCD by grading the alkali burn, corneal haze, and vascularization. Additionally, cells present on the corneal surface after the burn was investigated by histology and immunophenotyping. Grading of rabbit eyes post-alkali burn had shown complete conjunctivalization in 80% (n = 12/15) of the rabbits with the alkali burn grade score of 3.88 ± 0.29 in three months and remained stable at four months (4.12 ± 0.24). However, ocular surface showed self-healing in 20% (n = 3/15) of the rabbits with a score of 1.67 ± 0.34 in four months irrespective of similar alkali injury. These self-healing corneas exhibited decreased opacity score from 2.51 ± 0.39 to 0.66 ± 0.22 (p = 0.002) and regressed vascularity from 1.66 ± 0.41 to 0.66 ± 0.33 in one to nine months, respectively. Restoration of the corneal phenotype (CK3+) was observed in central and mid-peripheral regions of the self-healing corneas, and histology revealed the localization of inflammatory cells to the peripheral cornea when compared to conjunctivalized and scarred LSCD eyes. Our study shows the essentiality to consider the time required for surgical intervention after the corneal alkali injury in rabbit models as evident from their tendency to self-heal and restore corneal phenotype without therapy. Such information on the possibility of self-healing should be useful in further studies as well as determining interventional timings and strategy during clinical presentation of corneal alkali burns.

Rapamycin ameliorates corneal injury after alkali burn through methylation modification in mouse TSC1 and mTOR genes.

Alkali burn to the cornea is one of the most intractable injuries to the eye due to the opacity resulting from neovascularization (NV) and fibrosis. Numerous studies have focused on studying the effect of drugs on alkali-induced corneal injury in mouse, but fewer on the involvement of alkali-induced DNA methylation and the PI3K/AKT/mTOR signaling pathway in the mechanism of alkali-induced corneal injury. Thus, the aim of this study was to determine the involvement of DNA methyltransferase 3 B-madiated DNA methylation and PI3K/AKT/mTOR signaling modulation in the mechanism of alkali-induced corneal injury in a mouse model. To this end, we used bisulfite sequencing polymerase chain reaction and Western blot analysis, to study the effects of 5-aza-2'-deoxycytidine and 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one, which inhibit methyltransferase and PI3K respectively, on DNA methylation and expression of downstream effectors of PI3K related to corneal NV, including TSC1 and mTOR genes. The results showed that, after an intraperitoneal injection of rapamycin (2 mg/kg/day) for seven days, the alkali-induced opacity and NV were remarkably decreased mainly by suppressing the infiltration of immune cells into injured corneas, angiogenesis, VEGF expression and myofibroblasts differentiation; as well as by promoting corneal cell proliferation and PI3K/AKT/mTOR signaling. More significantly, these findings showed that epigenetic regulatory mechanisms by DNA methylation played a key role in corneal NV, including in corneal alkali burn-induced methylation modification and rapamycin-induced DNA demethylation which involved the regulation of the PI3K/AKT/mTOR signaling pathway at the protein level. The precise findings of morphological improvement and regulatory mechanisms are helpful to guide the use of rapamycin in the treatment of corneal angiogenesis induced by alkaline-burn.

Alkali Burn Over a LASIK Flap.

PURPOSE: To describe the management and outcome of an ocular surface alkali burn in the setting of previous laser in situ keratomileusis (LASIK). METHODS: This is a case report and review of relevant literature. RESULTS: A 25-year-old man with a history of LASIK presented 4 weeks after a sodium hydroxide splash to his left eye with visual acuity of 20/60 and a nonhealing epithelial defect adjacent to sectoral inferior limbal ischemia in the setting of trichiasis from upper eyelid cicatricial entropion. After topical corticosteroids were discontinued following the repair of the entropion, the patient returned 3 days later with worsening vision and severe diffuse lamellar keratitis with the melting of the LASIK flap. After promptly lifting the flap and debriding the interface, inflammation was managed with oral, instead of topical, corticosteroids. Over several weeks, the epithelium healed, and inflammation and interface edema resolved. At 10 years of follow-up, the patient had developed a localized pseudopterygium with mild corneal neovascularization but maintained 20/20 uncorrected visual acuity. CONCLUSIONS: A chemical burn over a LASIK flap poses a challenge for managing corticosteroids, which are required to prevent diffuse lamellar keratitis but can also contribute to keratolysis beyond the first week after an alkali injury. Oral corticosteroid therapy may be beneficial in this situation, with a low threshold to lift the LASIK flap and debride the interface if inflammation occurs.

In vivo biocompatibility and efficacy of dexamethasone-loaded PLGA-PEG-PLGA thermogel in an alkali-burn induced corneal neovascularization disease model.

Challenges of ophthalmic drug delivery arise not only from the limited solubility of hydrophobic therapeutics, but also the restricted permeability and fast clearance of drugs due to the complex anatomy and physiology of eyes. Excellent biocompatibility of a thermosensitive polymer, PLGA-PEG-PLGA (1800-1500-1800, LA:GA ratio = 3:1), as an ophthalmic delivery system was demonstrated in our previous work. In this study, delivery of dexamethasone using this thermogel via a single subconjunctival injection for prolonged treatment was evaluated with corneal neovascularization using an alkali-burn diseased model in rat. Solubility of dexamethasone in the polymeric solution was increased by 5.2-fold and the resulting drug-loaded solution formed in situ rigid gel at body temperature. Prolonged in vitro release of dexamethasone from the gel structure was noted. Dexamethasone gel formulation was demonstrated to be more effective in reducing the burn stimulus and neovascularization in the rat diseased model. The findings suggest the PLGA-PEG-PLGA in situ gelling system can be applied for ophthalmic drug delivery to achieve sustained drug release and improved efficacy.

Irrigation with phosphate-buffered saline causes corneal calcification during treatment of ocular burns.

Corneal calcification is a vision-threatening manifestation of calcium containing agents in ocular burn. As we previously reported, our interest was sparked by a particular discrepancy of a case: A patient treated for a non-calcium containing agent in eye burn from exposure to an alkaline mixture of NaOH and KOH, who unexpectedly developed corneal calcification. This current study aims to elucidate whether the 2min lasting irrigation with a phosphate-buffered saline itself, regardless of rinsing regimen, triggers corneal calcification. The Ex Vivo Eye Irritation Test (EVEIT) system was used on rabbit corneas to replicate the very same phosphate-buffered saline solution the patient was treated with. The rabbit corneas were first burned with 1 M NaOH, rinsed with 4.9% phosphate-buffered saline for 2 min, and were then moisturized with an artificial tear solution for 48 h. All corneas were fluorescein-stained for photo documentation, snap-frozen, lyophilizated, and the electrolyte content was analyzed by Energy-Dispersive X-ray spectroscopy (EDX). The EDX analysis revealed pathological phosphorous in corneal stroma after a single rinsing with phosphate-buffered saline. Ongoing application of artificial tears containing physiological 14.581 mmol Ca2+ /l led to macroscopically visible calcification, but only in areas of induced corneal erosion. Regardless of the rinsing protocol neither 2 or 15 min of eye rinsing with phosphate containing rinsing solutions, we have given proof that corneal calcification is a foreseeable effect of the phosphate-buffered saline rinsing of mechanically epithelial damaged and chemically burnt eyes. Thus, it is crucial to legally restrict the formulations of phosphate-buffered salines in the medical treatment of eye burns, corneal erosions or chemical splashes of the eye.

Induction of Fibroblast Senescence During Mouse Corneal Wound Healing.

Purpose: To investigate the presence and role of fibroblast senescence in the dynamic process of corneal wound healing involving stromal cell apoptosis, proliferation, and differentiation. Methods: An in vivo corneal wound healing model was performed using epithelial debridement in C57BL/6 mice. The corneas were stained using TUNEL, Ki67, and α-smooth muscle actin (α-SMA) as markers of apoptosis, proliferation, and myofibroblastic differentiation, respectively. Cellular senescence was confirmed by senescence-associated ß-galactosidase (SA-ß-gal) staining and P16Ink4a expression. Mitogenic response and gene expression were compared among normal fibroblasts, H2O2-induced senescent fibroblasts, and TGF-ß-induced myofibroblasts in vitro. The senescence was further detected in mouse models of corneal scarring, alkali burn, and penetrating keratoplasty (PKP). Results: The apoptosis and proliferation of corneal stromal cells were found to peak at 4 and 24 hours after epithelial debridement. Positive staining of SA-ß-gal was observed clearly in the anterior stromal cells at 3 to 5 days. The senescent cells displayed P16Ink4a+ vimentin+ α-SMA+, representing the major origin of activated corneal resident fibroblasts. Compared with normal fibroblasts and TGF-ß-induced myofibroblasts, H2O2-induced senescent fibroblasts showed a nonfibrogenic phenotype, including a reduced response to growth factor basic fibroblast growth factor (bFGF) or platelet-derived growth factor-BB (PDGF-BB), increased matrix metalloproteinase (MMP)1/3/13 expression, and decreased fibronectin and collagen I expression. Moreover, cellular senescence was commonly found in the mouse corneal scarring, alkali burn, and PKP models. Conclusions: Corneal epithelial debridement induced the senescence of corneal fibroblasts after apoptosis and proliferation. The senescent cells displayed a nonfibrogenic phenotype and may be involved in the self-limitation of corneal fibrosis.

Rare chemical burns: Review of the Literature.

There are many chemicals that can cause burns. Although they are generally acidic and basic in nature, there are more than one million known chemical compounds, of which 300 have been declared highly hazardous chemical substances by the National Fire Protection Society. Chemical burns account for approximately 10.7% of all burn injuries and 30% of deaths because of burns. Chemicals can be classified as acid, alkali, organic, and inorganic compounds. Acids act by denaturing and coagulating proteins. Alkaline burns cause deeper burns than acid burns.

Sodium hydroxide treatment effectively inhibits PrPCWD replication in farm soil.

Chronic wasting disease (CWD) agents are shed into biological samples, facilitating their horizontal transmission between cervid species. Once prions enter the environment, binding of PrPCWD by soil particles may maintain them near the soil surface, posing a challenge for decontamination. A 2 N sodium hydroxide (NaOH) or 2% sodium hypochlorite (NaClO) solution is traditionally recommended for prion decontamination of equipment and surfaces. Using protein misfolding cyclic amplification with beads and a bioassay with TgElk mice, we compared the effects of these disinfectants in CWD-contaminated soil for 1 or 16 h to those of controls of known infectious titres. Our results suggest that 2 N NaOH in a 1/5 farm soil volume provides a large decrease (>102-fold) in prion infectivity.

The Effect of Interleukin 38 on Inflammation-induced Corneal Neovascularization.

BACKGROUND: Angiogenesis is tightly linked to inflammation. Cytokines of interleukin 1 (IL-1) family are key mediators in modulating inflammatory responses. METHODS: In this study, we examined the role of IL-38, a member of the IL-1 family, in mediating inflammation-induced angiogenesis. RESULTS: The results showed that the angiogenesis was attenuated by topical administration of IL-38 to the injured corneas in a mouse model of alkali-induced corneal neovascularization (CNV). Further study showed that the expression of inflammatory cytokines TNF-α, IL-6, IL-8 and IL-1ß was decreased in the IL-38-treated corneas. Moreover, the angiogenic activities including the proliferation, migration and tube formation of human retinal endothelial cells were reduced by IL-38 treatment in vitro. CONCLUSION: The data indicate that IL-38 modulates inflammation-induced angiogenesis.

Is sex a biological variable in corneal wound healing?

Wound healing differs significantly between men and women in a tissue-dependent manner. Dermal wounds heal faster in women whereas mucosal wounds heal faster in men. However, the effect of sex as a variable in corneal wound healing is largely unknown. The primary objective of this study was to test whether sex is a biological variable in corneal wound healing activated by the trauma or injury using an established in vivo rabbit model with male and female New Zealand White rabbits. Corneal wounds in rabbits were produced by a single topical alkali (0.5N Sodium hydroxide) application. Serial slit-lamp, stereo biomicroscopy, and applanation tonometry evaluated corneal opacity, anterior segment ocular health, and intraocular pressure (IOP), respectively, at various times during the study. Fourteen days after alkali-wound, corneal tissues were collected after humane euthanasia to examine cellular and molecular wound healing parameters. Quantitative PCR (qPCR) and immunofluorescence were used to quantify changes in the extracellular modeling protein levels of alpha-smooth muscle actin (α-SMA), Fibronectin (FN), Collagen-I (Col-I), and Transforming growth factor beta 1 (TGFß1) involved in corneal healing. Hematoxylin and Eosin (H&E) staining was used to study histopathological changes in morphology and TUNEL assay to evaluate levels of apoptotic cell death. Male and female rabbits showed no significant differences in corneal opacity (Fantes score) or intraocular pressure (IOP) values (9.5 ±â€¯0.5 mm Hg) in live animals. Likewise, no statistically significant sex-based differences in the mRNA levels of α-SMA (male = 5.95 ±â€¯0.21 fold vs. female = 5.32 ±â€¯0.043), FN (male = 3.02 ±â€¯0.24 fold vs. female = 3.23 ±â€¯0.27), Col-I (male = 3.12 ±â€¯0.37 fold vs. female = 3.31 ±â€¯0.24), TGFß1 (male = 1.65 ±â€¯0.06 fold vs. female = 1.59 ±â€¯0.053); and protein levels of α-SMA (male = 74.16 ±â€¯4.6 vs. female = 71.58 ±â€¯7.1), FN (male = 60.11 ±â€¯4.6 vs. female = 57.41 ±â€¯8.3), Col-I (male = 84.11 ±â€¯2.8 vs. female = 84.55 ±â€¯3.6), TGFß1 (male = 11.61 ±â€¯2.8 vs. female = 9.5 ±â€¯3.04) were observed. Furthermore, H&E and TUNEL analyses found no statistically significant differences in cellular structures and apoptosis, respectively, in male vs. female corneas. Consistent with earlier reports, wounded corneas showed significantly increased levels of these parameters compared to the unwounded corneas. Our data suggest that sex is not a major biological variable during active early stages of corneal wound healing in rabbits in vivo.

Inflammation, vascularization and goblet cell differences in LSCD: Validating animal models of corneal alkali burns.

Limbal stem cell deficiency (LSCD) is one of the serious cause of visual impairment and blindness with loss of corneal clarity and vascularization. Factors such as ocular burns (acids, lime, thermal), genetic disorders or infections results in the loss of limbal stem cells leading to LSCD. Reliable animal models of LSCD are useful for understanding the pathophysiology and developing novel therapeutic approaches. The purpose of the present study was to validate small and large animal models of LSCD by immunohistochemcal, clinical and histopathological comparison with human. The animal models of LSCD were created by topical administration of sodium hydroxide on the ocular surface of C57BL/6 mice (m, n = 12) and New Zealand white rabbits (r, n = 12) as per the standard existing protocol. Human corneal specimens (h, n = 12) were obtained from tissue bank who had chemical burn-induced LSCD. All samples were either paraffin embedded or frozen in cryogenic medium and the sections were processed for Hematoxylin-Eosin and Periodic Acid-Schiff staining to analyse the morphology and histopathological features of the corneal surface such as vascularization, inflammation, presence of goblet cells, epithelial hyperplasia and keratinization. Immunofluorescence was performed to distinguish between corneal (CK3+), conjunctival (CK19+) and epidermal (CK10+) epithelial phenotype. Histological analysis of corneal specimens from the three groups showed the presence of goblet cells (h:83%, m:50%, r:50%, p = 0.014), epithelial hypertrophy (h:92%, m:50%, r:66.6%, p = 0.04), epithelial hyperplasia (h:50%, m:17%, r:17%, p = 0.18), intra epithelial edema (h:42%, m:33%, r:100%, p = 0.02), stromal inflammation (h:100%, m:67%, r:67%, p = 0.01) and stromal vascularization (h:100%, m:50%, r:67%), in varying proportions. Immunostaining showed presence of total LSCD (CK19 + and/or CK10+, CK3-) in 92% of human and 50% of animal specimens. While partial LSCD (CK19 + and/or CK10+, CK3+) was seen in 8% of human and 50% of animal specimens. Our study shows the significant differences in the extent of vascularization, inflammation, epithelial thickness and goblet cell formation in mice and rabbit models of LSCD when compared to post-chemical burn LSCD in human corneas. In both mice and rabbit models complete LSCD developed in only 50% of cases and this important fact needs to be considered when working with animal models of LSCD.

Molecular Bacterial Load Assay Concurs with Culture on NaOH-Induced Loss of Mycobacterium tuberculosis Viability.

Effective methods to detect viable Mycobacterium tuberculosis, the main causative agent of tuberculosis (TB), are urgently needed. To date, cultivation of M. tuberculosis is the gold standard, which depends on initial sample processing with N-acetyl-l-cysteine-sodium hydroxide (NALC-NaOH), chemicals that compromise M. tuberculosis viability and, consequently, the performance of downstream tests. We applied culture and the novel molecular bacterial load assay (MBLA) to measure the loss of M. tuberculosis viability following NALC-NaOH treatment of M. tuberculosis H37Rv pure culture and clinical sputum samples from pulmonary TB patients. Compared to the bacterial loads of untreated controls, NALC-NaOH treatment of M. tuberculosis reduced the MBLA-detectable bacillary load (estimated number of CFU [eCFU] per milliliter) by 0.66 ± 0.21 log10 at 23°C (P = 0.018) and 0.72 ± 0.08 log10 at 30°C (P = 0.013). Likewise, NALC-NaOH treatment reduced the viable count on solid culture by 0.84 ± 0.02 log10 CFU/ml at 23°C (P < 0.001) and 0.85 ± 0.01 log10 CFU/ml at 30°C (P < 0.001), respectively. The reduction in the viable count was reflected by a corresponding increase in the time to positivity of the mycobacterial growth indicator tube (MGIT) liquid culture: 1.2 days at 23°C (P < 0.001) and 1.1 days at 30°C (P < 0.001). This NaOH-induced M. tuberculosis viability loss was replicated in clinical sputum samples, with the bacterial load dropping by 0.65 ± 0.17 log10 from 5.36 ± 0.24 log10 eCFU/ml to 4.71 ± 0.16 log10 eCFU/ml for untreated and treated sputa, respectively. Applying the model of Bowness et al. (R. Bowness, M. J. Boeree, R. Aarnoutse, R. Dawson, et al., J Antimicrob Chemother 70:448-455, 2015, https://doi.org/10.1093/jac/dku415) revealed that the treated MGIT time to culture positivity of 142 ± 7.02 h was equivalent to 4.86 ± 0.28 log10 CFU, consistent with the MBLA-measured bacterial load. Our study confirms the contribution of NALC-NaOH treatment to the loss of viable bacterial counts. Tests that obviate the need for decontamination may offer an alternative option for the accurate detection of viable M. tuberculosis and treatment response monitoring.

Efficacy of Sunitinib, Sunitinib-Hesperetin, and Sunitinib-Doxycycline Combinations on Experimentally-Induced Corneal Neovascularization.

Purpose: To investigate the preventive effects of topical sunitinib, sunitinib-hesperetin and sunitinib-doxycycline combinations on corneal neovascularization (CNV), apoptosis and fibrosis in a corneal alkali burn model. Materials and Methods: The corneas of 32 Wistar albino rats were cauterized with silver nitrate to induce CNV. Four groups were created receiving artificial tears (sham), sunitinib (0.5 mg/ml), sunitinib-hesperetin (0.5 mg/ml-0.2 mg/ml), and sunitinib-doxycycline (0.5 mg/ml-20 mg/ml) treatments. Corneal photographs were taken on days 0, 7 and 15 . Photographs of the cornea were digitally analyzed to measure the size of the neovascularization area in comparison to the total corneal surface area. On the 15th day, the animals were euthanized, and the eyes were enucleated for immunohistochemical staining to investigate neovascularization, apoptosis, and fibrosis. Results: CNV areas on the 7th day in the sunitinib (4.8% ± 0.07%) and sunitinib-hesperetin (1.1% ± 0.03%) groups were smaller than those in the sham group (33.9% ± 0.12%) (p = 0.001 and, p < 0.001 respectively). On the 15th day, the CNV area in the sunitinib-hesperetin (20.8% ± 0.37%) group was significantly smaller than that of the sham group (74.6% ± 0.32%) (p = 0.039). The combination groups had lower levels of VEGF, TUNEL and α-SMA positivity than the sunitinib monotherapy group. TUNEL positivity was lowest in the sunitinib-hesperetin and sunitinib-doxycycline groups, and α-SMA positivity was lowest in the sunitinib-hesperetin group. Conclusion: Topical sunitinib-hesperetin was more effective than sunitinib alone and the sunitinib-doxycycline combination in the treatment of CNV. The combination of sunitinib and hesperetin seems to be a promising treatment for preventing corneal fibrosis and apoptosis.