A novel ophthalmic latanoprost 0.005% nanoemulsion: a cytotoxicity study.

BACKGROUND: Benzalkonium chloride (BAK), the most commonly used preservative in anti-glaucoma eye drops, inflicts damage to the ocular surface. A novel anti-glaucoma formulation that avoids the use of BAK has been developed. The aim of this study was to evaluate the cytotoxicity of this formulation and to compare it with an ophthalmic solution containing BAK. METHODS: Two different latanoprost eye drops were used: one ophthalmic solution (LSc) containing BAK 0.02% and one ophthalmic nanoemulsion (LNe) with a soft preservative (potassium sorbate 0.18%). Human epithelial conjunctival cells were incubated for 15, 30, and 60 min with either LSc or LNe. The cytotoxicity was determined by MTT assay. Cell death was measured by flow cytometry using annexin V-FITC and propidium iodide. RESULTS: The values of cell viability and proliferation obtained from cells exposed to LNe were between 80 and 90% relative to the control group, whereas values obtained from cells exposed to LSc were around 30% at all study times (p < 0.05 at 15 and 30 min; p < 0.01 at 60 min). The percentage of viable cells decreased significantly when cells were incubated with LSc compared with cells incubated with LNe at all the study times, while the percentage of cells in late apoptosis/necrosis increased significantly in cells exposed to LSc compared to LNe. CONCLUSIONS: The new latanoprost nanoemulsion is significantly less cytotoxic on human conjunctival cells than LSc. These results suggest that the new formulation might be gentler on the eye surface than currently available BAK-preserved latanoprost solutions.

Urban air pollution induces redox imbalance and epithelium hyperplasia in mice cornea.

The aim of the study was to evaluate the time course of the effects of urban air pollutants on the ocular surface, focusing on the morphological changes, the redox balance, and the inflammatory response of the cornea. 8-week-old mice were exposed to urban or filtered air (UA-group and FA-group, respectively) in exposure chambers for 1, 2, 4, and 12 weeks. After each time, the eyes were enucleated and the corneas were isolated for biochemical analysis. UA-group corneas exhibited a continuous increase in NADPH oxidase-4 levels throughout the exposure time, suggesting an increased production of reactive oxygen species (ROS). After 1 week, an early adaptive response to ROS was observed as an increase in antioxidant enzymes. After 4 weeks, the enzymatic antioxidants were decreased, meanwhile an increase of the glutathione was shown, as a later compensatory antioxidant response. However, redox imbalance took place, evidenced by the increased oxidized proteins, which persisted up to 12 weeks. At this time point, corneal epithelium hyperplasia was also observed. The inflammatory response was modulated by the increase in IL-10 levels after 1 week, which early regulates the release of TNF-α and IL-6. These results suggest that air pollution alters the ocular surface, supported by the observed cellular hyperplasia. The redox imbalance and the inflammatory response modulated by IL-10 play a key role in the response triggered by air pollutants on the cornea. Taking into account this time course study, the ocular surface should also be considered as a relevant target of urban air pollutants.

Diesel exhaust particles (DEP) induce an early redox imbalance followed by an IL-6 mediated inflammatory response on human conjunctival epithelial cells.

The aim of this study was to evaluate the time course of oxidative stress markers and inflammatory mediators in human conjunctival epithelial cells (IOBA-NHC) exposed to diesel exhaust particles (DEP) for 1, 3, and 24 h. Reactive oxygen species (ROS) production, lipid and protein oxidation, Nrf2 pathway activation, enzymatic antioxidants, glutathione (GSH) levels and synthesis, as well as cytokine release and cell proliferation were analyzed. Cells exposed to DEP showed an increase in ROS at all time points. The induction of NADPH oxidase-4 appeared later than mitochondrial superoxide anion production, when the cell also underwent a proinflammatory response mediated by IL-6. DEP exposure triggered the activation of Nrf2 in IOBA-NHC, as a strategy for increasing cellular antioxidant capacity. Antioxidant enzyme activities were significantly increased at early stages except for glutathione reductase (GR) that showed a significant decrease after a 3-h-incubation. GSH levels were found increased after 1 and 3 h of incubation with DEP, despite the increase in its consumption by the antioxidant enzymes as it works as a cofactor. GSH recycling and the de novo synthesis were responsible for the maintenance of its content at these time points, respectively. After 24 h, the decrease in GR and glutamate cysteine ligase as wells as the enhanced activity of glutathione peroxidase and glutathione S-transferase produced a depletion in the GSH pool. Lipid-peroxidation was found increased in cells exposed to DEP after 1-h-incubation, whereas protein oxidation was found increased in cells exposed to DEP after a 3-h-incubation that persisted after a longer exposure. Furthermore, DEP lead IOBA-NHC cells to hyperplasia after 1 and 3 h of incubation, but a decrease in cell proliferation was found after longer exposure. ROS production seems to be an earlier event triggered by DEP on IOBA-NHC, comparing to the proinflammatory response mediated by IL-6. Despite the fact that under short periods of exposure to DEP lipids and then proteins are targets of oxidative damage, the viability of the cells is not affected at early stages, since cell hyperplasia was detected as compensatory mechanism. Although after 24 h Nrf2 pathway is still enhanced, the epithelial cell capacity to maintain redox balance is exceeded. The antioxidant enzymes activation and the depleted GSH pool are not capable of counteracting the increased ROS production, leading to oxidative damage.

Volcanic ash from Puyehue-Cordón Caulle Volcanic Complex and Calbuco promote a differential response of pro-inflammatory and oxidative stress mediators on human conjunctival epithelial cells.

Volcanic ash could pose a hazard to the ocular surface as it is constantly exposed to environmental particles. We exposed conjunctival cells to Puyehue-Cordón Caulle volcanic complex (PCCVC) or Calbuco ash particles and evaluated proliferation, viability, apoptosis, MUC1 expression, pro-inflammatory cytokines, and oxidative stress markers. Ash particles from these volcanoes vary in size, composition, and morphology. Our results demonstrate that PCCVC but not Calbuco ash particles induce cytotoxicity on human conjunctival epithelial cells viewed as a decrease in cell proliferation and the transmembrane mucin MUC1 expression; a pro-inflammatory response mediated by IL-6 and IL-8; and an imbalance of the redox environment leading to protein oxidative damage. This is the first in vitro study that assesses the biological effect of volcanic ash particles on human conjunctival epithelial cells and the involvement of inflammatory mediators and oxidative stress as the mechanisms of damage. Our results could provide a better understanding of the ocular symptoms manifested by people living near volcanic areas.

Sex-dependent effect of sublethal copper concentrations on de novo cholesterol synthesis in astrocytes and their possible links to variations in cholesterol and amyloid precursor protein levels in neuronal membranes.

BACKGROUND: Cholesterol (Cho) is an essential lipophilic molecule in cells; however, both its decrease and its increase may favor the development of neurological diseases such as Alzheimer's disease (AD). Although copper (Cu) is an essential trace metal for cells, the increased plasma concentration of its free form has been linked with AD development and severity. AD affects aged people, but its prevalence and severity are higher in women than in men. We have previously shown that Cu promotes Cho de novo synthesis in immature neurons as well as increased Cho in membrane rafts and Aß levels in culture medium, but there are no results yet regarding sex differences in the effects of sublethal Cu exposure on Cho de novo synthesis. METHODS: We examined the potential sex-specific impact of sublethal Cu concentrations on de novo Cho synthesis in primary cultures of male and female astrocytes. We also explored whether this had any correlation with variations in Cho and APP levels within neuronal membrane rafts. RESULTS: Flow cytometry analysis demonstrated that Cu treatment leads to a greater increase in ROS levels in female astrocytes than in males. Furthermore, through RT-PCR analysis, we observed an upregulation of SREBP-2 and HMGCR. Consistently, we observed an increase in de novo Cho synthesis. Finally, western blot analysis indicated that the levels of ABCA1 increase after Cu treatment, accompanied by a higher release of radiolabeled Cho and an elevation in Cho and APP levels in neuronal membrane rafts. Importantly, all these results were significantly more pronounced in female astrocytes than in males. CONCLUSIONS: Our findings confirm that Cu stimulates Cho synthesis in astrocytes, both in a ROS-dependent and -independent manner. Moreover, female astrocytes displayed elevated levels of HMGCR, and de novo Cho synthesis compared to males following TBH and Cu treatments. This corresponds with higher levels of Cho released into the culture medium and a more significant Cho and APP rise within neuronal rafts. We consider that the increased risk of AD in females partly arises from sex-specific responses to metals and/or exogenous substances, impacting key enzyme regulation in various biochemical pathways, including HMGCR.

Alzheimer's disease (AD) primarily affects the elderly and is linked to excess cholesterol (Cho) and copper (Cu). It is more prevalent and severe in women. Previous research suggested that Cu may enhance Cho synthesis in developing neurons, raising Cho levels in specialized membrane structures (rafts) and Aß protein in the culture medium. However, the specific effects of Cu exposure on Cho synthesis in males and females are not entirely understood. We conducted experiments using astrocytes, the primary cells in the brain that produce Cho in adults, and neurons, both from male and female rats. We exposed them to non-lethal levels of Cu to explore its potential sex-related effects on (1) Cho metabolism in astrocytes, and (2) The relationship between the Cho released by astrocytes and the levels of Cho and amyloid precursor protein (APP) in neuronal membrane rafts. Our findings suggested that reactive oxygen species (ROS)-responsive sensitivity is higher in females than in male astrocytes. Cu, alongside ROS, promoted Cho synthesis, with female astrocytes being more susceptible. These released more Cho into the medium after Cu exposure, and Cho and APP levels were also higher in female neuronal rafts exposed to Cu-treated astrocyte-conditioned medium. Our results thus imply that the higher risk of AD in females may arise partly from sex-related disparities in cellular responses to external substances, impacting such crucial biochemical pathways as Cho synthesis.

Alpha hemolysin of Escherichia coli induces a necrotic-like procoagulant state in platelets.

Uropathogenic strains of E. coli (UPEC) is a leading cause of sepsis, deploying multiple virulence factors to evade host immune responses. Notably, alpha-hemolysin (HlyA) produced by UPEC is implicated in septic symptoms associated with bacteremia, correlating with thrombocytopenia, a critical indicator of organ dysfunction and a predictor of poorer patient prognosis. This study meticulously explores the impact of sublytic concentrations of HlyA on platelets. Findings reveal that HlyA triggers an increase in intracellular calcium, activating calpain and exposing phosphatidylserine to the cell surface, as validated by flow cytometric experiments. Electron microscopy reveals a distinctive balloon-like shape in HlyA-treated platelets, indicative of a procoagulant state. The toxin induces the release of procoagulant extracellular vesicles and the secretion of alpha and dense granules. Overall, the results point to HlyA inducing a necrotic-like procoagulant state in platelets. The effects of sublytic concentrations of HlyA on both erythrocytes and platelets could have a potential impact on capillary microcirculation. Targeting HlyA emerges as a viable therapeutic strategy to mitigate the adverse effects of UPEC infections, especially in South American countries where these infections are endemic, underscoring its significance as a potential therapeutic target.

[Crystalline keratopathy: an infrequent corneal infection produced by the Streptococcus mitis group]. / Queratopatía cristalina: diagnóstico clínico y microbiológico de una infección corneal infrecuente causada por el grupo Streptococcus mitis.

The objective of this report is to describe a case of crystalline keratopathy caused by the Streptococcus mitis group corresponding to a patient who attended hospital for discomfort in her right eye. The ophthalmological examination showed an interrupted stitch of 10-0 nylon suture without tension and with attached mucus secretions. The loose suture was removed under aseptic conditions. Moxifloxacin 0.5 % eye drops were topically indicated. The treated eye successfully epithelialized and evolved favorably. However, after 15 days, a white tree-shaped infiltrate developed. A corneal sample was taken in the operating room, threading the intrastromal path of the removed stitch with a 7-0 vicryl suture. Vancomycin 50 mg/ml drops were indicated. The infiltrate, which was stable for 45 days, later increased its size and tissue necrosis occurred with danger of corneal perforation. A bipedicle conjunctival flap was performed in the affected corneal area, which evolved favorably. After spontaneous conjunctival flap retraction, only corneal scarring and neovascularization outside the visual axis were observed.

Tear Lysozyme in Sjögren´s syndrome, Meibomian gland dysfunction, and non-dry-eye.

PURPOSE: To evaluate the concentration of tear lysozyme in individuals with Sjogren´s syndrome, meibomian gland dysfunction, and non-dry-eye disease. METHODS: Ninety subjects were recruited for this study, including 30 with Sjogren´s syndrome, 30 with meibomian gland dysfunction, and 30 with non-dry-eye disease. All subjects were referred to participate in the study based on a "dry eye" investigation. They underwent a complete ocular surface ophthalmic examination encompassing ocular surface disease index, biomicroscopy, tear break-up time, Schirmer test type I, conjunctival vital staining with fluorescein and lissamine green, tear lysozyme concentration, and impression cytology. RESULTS: Clinical tests yielded the following results: ocular surface disease index Sjogren´s syndrome: 64.5 ± 22.6 meibomian gland dysfunction: 43.5 ± 21.4, non-dry-eye disease: 6.7 ± 4.3 (p=0.02 between groups); Schirmer I test (mm/5 min): Sjogren´s syndrome: 4.95 ± 2.25, meibomian gland dysfunction: 13.28 ± 1.53, non-dry-eye disease 13.70 ± 1.39 (p<0.01 Sjogren´s syndrome vs. non-dry-eye disease and p<0.01 meibomian gland dysfunction vs. non-dry-eye disease); tear break-up time (seconds): Sjogren´s syndrome: 3.97 ± 1.47, meibomian gland dysfunction: 3.95 ± 0.86, non-dry-eye disease: 7.25 ± 1.90 (p<0.01 Sjogren´s syndrome vs. non-dry-eye disease and p<0.01 meibomian gland dysfunction vs. non-dry-eye disease); Lissamine green score: Sjogren´s syndrome-dry-eye: 6.18 ± 2.14, meibomian gland dysfunction-dry-eye: 5.27 ± 1.27, non-dry-eye disease: 1.52 ± 0.97 (p<0.01 Sjogren´s syndrome vs. non-dry-eye disease and p<0.01 meibomian gland dysfunction vs. non-dry-eye disease); impression cytology score: Sjogren´s syndrome: 1.88 ± 0.92, meibomian gland dysfunction: 1.67 ± 0.56, non-dry-eye: 0.45 ± 0.44 (p<0.01 Sjogren´s syndrome vs. non-dry-eye disease and p<0.01 meibomian gland dysfunction vs. non-dry-eye disease) and; tear lysozyme concentration (µg/mL): Sjogren´s syndrome: 751.25 ± 244.73, meibomian gland dysfunction: 1423.67 ± 182.75, non-dry-eye disease: 1409.90 ± 188.21 (p<0.01 Sjogren´s syndrome vs. non-dry-eye disease and p<0.01 Sjogren´s syndrome vs. meibomian gland dysfunction). CONCLUSION: The concentration of lysozyme in the tears was lower in Sjögren's syndrome patients than in meibomian gland dysfunction and non-dry-eye disease groups. Hence, the lacrimal lysozyme could be considered as a simple, non-invasive, and economical biomarker to differentiate between Sjögren's syndrome dry eye disease and meibomian gland dysfunction dry eye disease.

Polluted Air Exposure Compromises Corneal Immunity and Exacerbates Inflammation in Acute Herpes Simplex Keratitis.

Air pollution is a serious environmental issue worldwide in developing countries' megacities, affecting the population's health, including the ocular surface, by predisposing or exacerbating other ocular diseases. Herpes simplex keratitis (HSK) is caused by the herpes simplex virus type 1 (HSV-1). The primary or recurring infection in the ocular site causes progressive corneal scarring that may result in visual impairment. The present study was designed to study the immunopathological changes of acute HSK under urban polluted air, using the acute HSK model combined with an experimental urban polluted air exposure from Buenos Aires City. We evaluated the corneal clinical outcomes, viral DNA and pro-inflammatory cytokines by RT-PCR and ELISA assays, respectively. Then, we determined the innate and adaptive immune responses in both cornea and local lymph nodes after HSV-1 corneal by immunofluorescence staining and flow cytometry. Our results showed that mice exposed to polluted air develop a severe form of HSK with increased corneal opacity, neovascularization, HSV-1 DNA and production of TNF-α, IL-1ß, IFN-γ, and CCL2. A high number of corneal resident immune cells, including activated dendritic cells, was observed in mice exposed to polluted air; with a further significant influx of bone marrow-derived cells including GR1+ cells (neutrophils and inflammatory monocytes), CD11c+ cells (dendritic cells), and CD3+ (T cells) during acute corneal HSK. Moreover, mice exposed to polluted air showed a predominant Th1 type T cell response over Tregs in local lymph nodes during acute HSK with decreased corneal Tregs. These findings provide strong evidence that urban polluted air might trigger a local imbalance of innate and adaptive immune responses that exacerbate HSK severity. Taking this study into account, urban air pollution should be considered a key factor in developing ocular inflammatory diseases.

A Pilot Cross-Sectional Study to Investigate the Biomarker Potential of Phosphorylated Neurofilament-H and Immune Mediators of Disability in Patients With 5 Year Relapsing-Remitting Multiple Sclerosis.

Objective: To test the feasibility of conducting a full-scale project evaluating the potential value of the phosphorylated neurofilament H (pNF-H) and several cytokines as disability markers in relapsing-remitting multiple sclerosis (RRMS). Methods: Twenty-four patients with 5-year RRMS evolution and eleven healthy control subjects entered the study. None of the participants had an inflammatory systemic or metabolic disease. Disability progression was evaluated using the Expanded Disability Status Scale. Serum level of pNF-H, the anti-inflammatory cytokine transforming growth factor-ß 1 (TGF-ß1), and the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-17A (IL-17A), monocyte chemotactic protein-1 (MCP-1), and soluble intercellular cell-adhesion molecule 1 (sICAM-1) were quantified using enzyme-linked immunosorbent assay (ELISA). Results: The patients had higher serum level of TGF-ß1, IL-6, sICAM-1, and pNF-H. Based on these findings, a sample of at least 49 controls and 89 recent-onset RRMS patients is required to find an at least 1-point between-group difference in pNF-H with a power of 80% and an α error = 0.05. The progression of the disease was correlated with the level of pNF-H (Spearman rho = 0.624, p = 0.006), but not with the cytokines'. Conclusions: The serum level of pNF-H, EDSS score-correlated, might stand for a potential biomarker of disability in RRMS reflecting progressive axonal damage and cumulative neurological deterioration. The novelty of these results warrants conducting a larger confirmatory trial.

Impact of environmental pollution on the ocular surface of Sjögren's syndrome patients.

PURPOSE: To evaluate the effect of air pollution on the ocular surface of patients with Sjögren's syndrome. METHODS: We investigated the ocular surfaces of thirty patients with Sjögren's syndrome and thirty healthy volunteers (control group) living in the Metropolitan Area of Buenos Aires. We used nitrogen dioxide as an indicator of exposure to air pollution. An ocular symptoms questionnaire was answered by all subjects, who also underwent a complete ocular surface ophthalmic examination-including an Ocular Surface Disease Index questionnaire, biomicroscopy, tear breakup time, Schirmer 1 test, corneal and conjunctival vital staining with fluorescein and lissamine green, tear lysozyme concentration, and impression cytology. RESULTS: In almost all ocular surface test findings, we found a positive and significant correlation between higher levels of exposure to air pollution and higher levels of ocular surface damage in both the control group and Sjögren's syndrome patients. In Sjögren's syndrome patients, the Ocular Surface Disease Index questionnaire, tear breakup time, vital staining and impression cytology showed a significant correlation between high levels of air pollution and ocular surface disease. In the control group, the Ocular Surface Disease Index questionnaire, tear breakup time, and impression cytology showed a significant correlation between high levels of air pollution and ocular surface disease. CONCLUSIONS: Here we demonstrated that in patients with dry eye syndrome associated with Sjögren, abnormalities of the ocular surface and eye irritation related to air pollution are more severe than those in the control group. We believe that measuring air quality should be not only an integral part of the evaluation of ocular surface disease but also a therapeutic consideration.

Immune-Mediated Inflammation Promotes Subclinical Atherosclerosis in Recent-Onset Psoriatic Arthritis Patients without Conventional Cardiovascular Risk Factors.

Studies on the inflammatory burden in recent-onset psoriatic arthritis (PsA) patients without conventional cardiovascular risk factors (CVRFs) are not available. This preliminary study focuses on cardiovascular risk in cutaneous psoriasis (CPs) and recent-onset PsA patients. Blood biochemistry (glucose, cholesterol, uric acid, lipid profile and apolipoprotein B) was analyzed using standard kits. Proatherogenic inflammation markers, C-reactive protein (CRP) and interleukin-6 (IL-6), and endothelial activators monocyte chemoattractant protein-1 (MCP-1) and soluble intercellular adhesion molecule-1 (sICAM-1), were determined by enzyme-linked immunosorbent assay. Ultrasound images allowed measuring carotid intima-media thickness (cIMT). Our study first shows an increase in cIMT, and in serum levels of sICAM-1 and CRP in recent-onset PsA patients not presenting conventional CVRFs over the non-medicated time-period, from disease diagnosis to the beginning of pharmacological treatment, compared with healthy subjects. The outcome highlights the importance of monitoring serum level of sICAM1, CRP, and cIMT, and the value of primary prevention in psoriatic patients even with no history of cardiovascular events.

Effects of PUFAs in a Mouse Model of HSV-1 Chorioretinitis.

PURPOSE: To examine the effects of n-3 and n-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs) in a murine model of herpetic chorioretinitis. METHODS: BALB/c mice were fed on three high fat diets, which contained: Menhaden oil (rich in n-3 PUFAs); Safflower oil (rich in n-6 PUFAs); or Corn oil (rich in saturated fatty acids) as control group, 14 days previously and until 12 days following anterior chamber (AC) HSV-1 inoculation. RESULTS: Mice fed on Menhaden oil present an early development of contralateral chorioretinitis by day 6 post-AC HSV-1 inoculation and also significant increase of RNA HSV-1 expression compared with Safflower and Corn oil groups. Furthermore, mice fed on Menhaden oil showed a significant decrease secretion of TNF-α, IFN-γ, IL-2 and IL-10 in splenic cells and both retinas. CONCLUSION: Our results showed that mice fed on Menhaden oil (n-3 PUFAs) presented an early development of contralateral chorioretinitis by day 6 post-AC HSV-1 inoculation and also a significant increase in RNA HSV-1 expression compared with animals fed on Safflower and Corn oils. This increase of HSV-1 could be associated with the higher development of chorioretinitis.

Neuronal Damage Induced by Perinatal Asphyxia Is Attenuated by Postinjury Glutaredoxin-2 Administration.

The general disruption of redox signaling following an ischemia-reperfusion episode has been proposed as a crucial component in neuronal death and consequently brain damage. Thioredoxin (Trx) family proteins control redox reactions and ensure protein regulation via specific, oxidative posttranslational modifications as part of cellular signaling processes. Trx proteins function in the manifestation, progression, and recovery following hypoxic/ischemic damage. Here, we analyzed the neuroprotective effects of postinjury, exogenous administration of Grx2 and Trx1 in a neonatal hypoxia/ischemia model. P7 Sprague-Dawley rats were subjected to right common carotid ligation or sham surgery, followed by an exposure to nitrogen. 1 h later, animals were injected i.p. with saline solution, 10 mg/kg recombinant Grx2 or Trx1, and euthanized 72 h postinjury. Results showed that Grx2 administration, and to some extent Trx1, attenuated part of the neuronal damage associated with a perinatal hypoxic/ischemic damage, such as glutamate excitotoxicity, axonal integrity, and astrogliosis. Moreover, these treatments also prevented some of the consequences of the induced neural injury, such as the delay of neurobehavioral development. To our knowledge, this is the first study demonstrating neuroprotective effects of recombinant Trx proteins on the outcome of neonatal hypoxia/ischemia, implying clinical potential as neuroprotective agents that might counteract neonatal hypoxia/ischemia injury.

Impact of wildfire smoke in Buenos Aires, Argentina, on ocular surface.

PURPOSE: To evaluate the acute impact of the wildfire smoke episode in 2008 on the ocular surface of subjects living in the Metropolitan Area of Buenos Aires (MABA). METHODS: A total of 86 subjects were evaluated: Group 1 comprised patients from a public ophthalmology hospital (N=35) and Group 2 comprised healthy volunteers (N=51). All subjects answered a questionnaire on ocular symptoms and underwent ophthalmologic examination [bulbar conjunctival hyperemia, corneal fluorescein staining, rose bengal vital staining, tear break-up time (TBUT), Schirmer I test, tear lysozyme, and impression cytology] during and after the acute episode. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and particulate matter (PM) were measured before, during, and after the acute episode. RESULTS: Both groups showed a statically significant increase in ocular symptoms and bulbar conjunctival hyperemia and a statically significant decrease in tear break-up time during the acute episode. Group 1 showed more severe symptoms and a statistically significant increase in fluorescein and rose bengal staining intensities during the acute episode. We found a significant negative correlation between ocular symptoms and tear break-up time. During the episode, the levels of CO, NO2, and particulate matter in MABA were four times higher than the usual average levels for the same period in 2007 and 2009. CONCLUSIONS: Increased air pollution from the burning of biomass is associated with a decrease in the stability of the tear film (TBUT), generating areas of ocular surface exposure that may be the cause of the increased feeling of irritation. Group 1 was more affected by not having a healthy ocular surface, and thus consulted an ophthalmologist. Cytological changes in the conjunctiva were not observed, which could be due to the short duration of the episode.

Evaluation of Oxidative Stress Markers in Human Conjunctival Epithelial Cells Exposed to Diesel Exhaust Particles (DEP).

PURPOSE: The aim of this study was to evaluate oxidative stress markers in human conjunctival epithelial cells (IOBA-NHC) exposed to diesel exhaust particles (DEP). METHODS: Reactive oxygen (ROS) and nitrogen (RNS) species production; hydrogen peroxide (H2O2) levels; protein oxidation; antioxidant enzymes activities (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], glutathione S-transferase [GST], and glutathione reductase [GR]); total reactive antioxidant potential (TRAP); reduced (GSH) and oxidized glutathione (GSSG) were evaluated. Transmission electron microscopy was performed to evaluate DEP uptake. RESULTS: Diesel exhaust particles were entrapped by membrane protrusions developed by IOBA-NHC. Cells exposed to DEP 50 and 100 µg/mL showed a significant increase in ROS, RNS, H2O2 levels, SOD, GPx, and GST compared with the control group. A significant decay in GR was observed in both groups, meanwhile CAT levels remained unchanged. The group exposed to DEP 100 µg/mL displayed a significant increase in protein oxidation. In both groups, TRAP was significantly reduced as well as the GSH/GSSG ratio. CONCLUSIONS: The decrease in nonenzymatic antioxidants and the compensatory increase of SOD, GPX, and GST activities are consequence of the increase in ROS and RNS production due to DEP exposure and its accumulation inside the cells. The decay in GR activity leads to the decrease in GSH/GSSG recycling. These results suggest that oxidative stress could play an important role in the development of DEP effects on human conjunctival epithelial cells.

Treatment of Acanthamoeba keratitis by corneal cross-linking.

PURPOSE: To evaluate the efficacy of corneal cross-linking (CXL; riboflavin/ultraviolet A) as a simple therapy for Acanthamoeba keratitis. METHODS: Twenty rabbits were systemically anesthetized and the stroma of their right corneas was inoculated with a suspension of Acanthamoeba. Rabbits were divided into 2 groups: one group was treated with corneal CXL 3 days after infection and the other did not receive any treatment (control). All eyes in both groups were examined before (days 0 and 3) and after (day 7) CXL treatment. On day 7, the eyes were enucleated; 18 corneal buttons (9 of each group) were sent for microbiological examination and 2 (1 of each group) for histopathologic examination. RESULTS: All animals developed Acanthamoeba keratitis. There was no statistically significant difference between groups before treatment (day 0, P = 1, and day 3, P = 0.684). The treated corneas had a higher score (3.48 ± 0.30) at the time of enucleation compared with control corneas (2.60 ± 0.26). This difference was statistically significant (P = 0.008). Microbiological analysis revealed that the treated corneas had a higher protozoal count (2.86 ± 0.09) compared with the control corneas (2.18 ± 0.07); this difference was statistically significant (P = 0.001). CONCLUSIONS: Treatment of Acanthamoeba keratitis by corneal CXL (riboflavin/ultraviolet A) did not prove effective in decreasing the intensity and severity of Acanthamoeba keratitis.

Diesel exhaust particles selectively induce both proinflammatory cytokines and mucin production in cornea and conjunctiva human cell lines.

PURPOSE: To evaluate the effect of diesel exhaust particles (DEP) on the viability, proliferation, apoptosis, secretion of cytokines (IL-6, IL-8, and TNF-α), and mucin gene transcription (MUC1, MUC5AC, and MUC16) in human epithelial cells of the cornea (HCLE) and conjunctiva (IOBA-NHC). METHODS: HCLE and IOBA-NHC cells were incubated with DEP (10-500 µg/mL) for 24 hours. Cell proliferation was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were measured by an annexin V-FITC and propidium iodide kit for flow cytometry. Proinflammatory cytokines were determined by an ELISA kit. Mucin gene transcription was quantified by real-time PCR. RESULTS: DEP significantly decreased the viability, proliferation, and secretion of IL-8, but increased the secretion of IL-6 on both HCLE and IOBA-NHC cell lines in a dose-dependent manner. Neither cornea nor conjunctiva cells incubated with DEP released TNF-α. DEP induced a significant increase in the percentage of apoptotic cells in IOBA-NHC, whereas no changes were observed in HCLE. Finally, DEP significantly decreased the transcription levels of MUC1 and MUC16 in HCLE, but increased the transcription levels of MUC1, MUC5AC, and MUC16 in IOBA-NHC. CONCLUSIONS: These findings suggest that human corneal and conjunctival epithelial cells incubated with DEP showed cytotoxicity and an inflammatory response mediated by IL-6, not by TNF-α or IL-8. Also, the decrease in mucin expression in the cornea cells might leave exposed areas in the cornea for contact with DEP. Finally, the increase in mucin expression in the conjunctiva cells might be involved at least in the clearance of DEP to protect the ocular epithelium.

Impact of environmental pollution on the ocular surface of Sjögren's syndrome patients / Impacto da poluição ambiental na superfície ocular de pacientes com síndrome de Sjögren

ABSTRACT Purpose: To evaluate the effect of air pollution on the ocular surface of patients with Sjögren's syndrome. Methods: We investigated the ocular surfaces of thirty patients with Sjögren's syndrome and thirty healthy volunteers (control group) living in the Metropolitan Area of Buenos Aires. We used nitrogen dioxide as an indicator of exposure to air pollution. An ocular symptoms questionnaire was answered by all subjects, who also underwent a complete ocular surface ophthalmic examination-including an Ocular Surface Disease Index questionnaire, biomicroscopy, tear breakup time, Schirmer 1 test, corneal and conjunctival vital staining with fluorescein and lissamine green, tear lysozyme concentration, and impression cytology. Results: In almost all ocular surface test findings, we found a positive and significant correlation between higher levels of exposure to air pollution and higher levels of ocular surface damage in both the control group and Sjögren's syndrome patients. In Sjögren's syndrome patients, the Ocular Surface Disease Index questionnaire, tear breakup time, vital staining and impression cytology showed a significant correlation between high levels of air pollution and ocular surface disease. In the control group, the Ocular Surface Disease Index questionnaire, tear breakup time, and impression cytology showed a significant correlation between high levels of air pollution and ocular surface disease. Conclusions: Here we demonstrated that in patients with dry eye syndrome associated with Sjögren, abnormalities of the ocular surface and eye irritation related to air pollution are more severe than those in the control group. We believe that measuring air quality should be not only an integral part of the evaluation of ocular surface disease but also a therapeutic consideration.

RESUMO Objetivo: Avaliar o efeito da poluição do ar na superfície ocular de pacientes com síndrome de Sjögren. Métodos: Foram investigadas as superfícies oculares de trinta pacientes com síndrome de Sjögren e trinta voluntários saudáveis (grupo controle) residentes na Região Metropolitana de Buenos Aires. Usamos o dióxido de nitrogênio como um indicador de exposição à poluição do ar. Um questionário de sintomas oculares foi respondido por todos os indivíduos, que também foram submetidos a um exame oftalmológico completo da superfície ocular - incluindo um questionário do Índice da Doença da Superfície Ocular, biomicroscopia, tempo de ruptura do filme lacrimal, teste de Schirmer 1, coloração da córnea e conjuntiva com fluoresceína e lissamina verde, concentração de lisozima lacrimal e citologia de impressão. Resultados: Em quase todos os achados do teste de superfície ocular, encontramos uma correlação positiva e significativa entre níveis mais altos de exposição à poluição do ar e níveis mais elevados de danos na superfície ocular tanto no grupo controle quanto nos pacientes com síndrome de Sjögren. Em pacientes com síndrome de Sjögren, o questionário do Índice da Doença da Superfície Ocular, tempo de ruptura do filme lacrimal, coloração vital e citologia de impressão mostraram uma correlação significativa entre altos níveis de poluição do ar e doença da superfície ocular. No grupo controle, o questionário do Índice de Doenças da Superfície Ocular, tempo de ruptura do filme lacrimal e citologia de impressão mostraram uma correlação significativa entre altos níveis de poluição do ar e doença da superfície ocular. Conclusões: Aqui demonstramos que, pacientes com síndrome de olho seco associada a Sjögren, as anormalidades da superfície ocular e a irritação ocular relacionadas à poluição do ar são mais graves do que aquelas no grupo controle. Acreditamos que a medição da qualidade do ar não deve ser apenas uma parte integral da avaliação da doença da superfície ocular, mas também uma consideração terapêutica.

Topical use of rapamycin in herpetic stromal keratitis.

PURPOSE: To evaluate and compare the efficacy of rapamycin used topically in a mouse model of herpetic stromal keratitis. METHODS: The corneas were infected with herpes simplex virus type-1 strain KOS. Animals were divided into: control (CG), rapamycin (RAPA), cyclosporine (CsA), and dexamethasone (DEXA). The evolution of the disease was assessed clinically and histologically. RESULTS: On day 10 postinfection (pi), the RAPA group showed only a significantly lower angiogenic development than the CG. On day 14 pi, the treated groups had significantly lower scores for angiogenesis and necrosis than the CG. Also, on day 14 pi, the RAPA and DEXA groups showed significantly lower histopathological scores compared to the CG. CONCLUSIONS: The topical application of 0.05% rapamycin showed greater efficacy than 0.5% cyclosporine and similar efficacy to 0.1% dexamethasone to minimize the immuno-inflammatory process. Also, rapamycin showed early inhibition of the formation of new vessels.