Effects of Th2 cytokines on expression of collagen, MMP-1, and TIMP-1 in conjunctival fibroblasts.

PURPOSE. To determine whether cytokines involved in chronic allergic conjunctival disorders may affect formation of giant papillae and tissue remodeling. METHODS. Conjunctival fibroblast cultures were challenged with different concentrations of human recombinant interleukin (IL)-4, IL-13, interferon (IFN)- and tumor necrosis factor (TNF)-. Procollagens I (PIP) and III (PIIIP), matrix metalloproteinase (MMP)-1 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants, and their respective mRNAs were evaluated by RT-PCR. RESULTS. IL-4 and -13 (10 ng/mL) significantly increased production and expression of PIP compared with nonstimulated cells, whereas IFN- elicited the opposite effect, at both the protein and mRNA levels. Both IL-4 and -13 significantly decreased production of MMP-1 and increased that of TIMP-1, whereas TNF- increased production of MMP-1 and -9. Expression of MMP-1 was reduced by IL-4 and increased by the other tested cytokines, whereas expression of TIMP-1 was increased by all tested cytokines. CONCLUSIONS. IL-4 and -13 increased production of collagen and modified the equilibrium between MMP-1 and its inhibitor, TIMP-1. These effects were partially opposed by IFN- and TNF- .( Invest Ophthalmol Vis Sci. 2003;44:183‐189) DOI

Th1- and Th2-type cytokines in chronic ocular allergy

BACKGROUND: Previous reports have suggested that Th2-type cytokines are important in the pathogenesis of ocular allergic diseases. The purpose of this study is to measure levels and mRNA expression of Th1- and Th2-type cytokines in patients with active vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). METHODS: Tear samples and tear-isolated cells were obtained from 9 healthy participants (CT--controls), 28 VKC, and 6 AKC patients. IL-4, IL-13, and interferon gamma (IFNgamma) tear levels were determined by ELISA, and IL-4 and IFNgamma tear cell mRNA expression by RT-PCR. Effects of these cytokines on IL-6 and IL-8 secretion, and on ICAM-1 expression by conjunctival fibroblasts, were evaluated by ELISA and flow cytometry respectively. RESULTS: Interleukin-4 tear levels were increased in VKC and AKC compared with CT, but only IFNgamma significantly correlated with corneal involvement. An IL-4/13-dominant profile was found in 50% of VKC and in 17% of AKC patients, while a IFNgamma-dominant profile was found in 18% of VKC and in 17% of AKC patients. IL-4 and IFNgamma transcripts were detected in tear cells from 11 out of 12 VKC patients. IFNgamma upregulated expression of ICAM-1 on conjunctival fibroblasts and the secretion of IL-6 and IL-8. CONCLUSIONS: Although both IL-4 and IFNgamma are detected in tears, only IFNgamma levels correlated with disease severity and upregulated ICAM-1 on conjunctival fibroblasts, suggesting the role of IFNgamma in the inflammatory phase of chronic allergic eye diseases

Early detection of university students in potential difficulty : a case study

Rate of success in the first year at University in Belgium is very low regarding other foreign universities. The University of Liege, as other Universities, has already taken different initiatives. But by early identifying students who have a high probability to face difficulties if nothing is done, the Universities might develop adapted methods to attack the problem with more emphasis where it is more needed and when it is still possible. Thus we want to develop a decision tool able to identify these students to help them. For that, we consider three standard datamining methods: logistic regression, artificial neural networks and decision trees and focus on early detection, i.e. before starting at the University. Then, we suggest to adapt these three methods as well as the classification framework in order to increase the probability of correct identification of the students. In our approach, we do not restrict the classification to two extreme classes, e.g. failure or success, but we create subcategories for different levels of confidence: high risk of failure, risk of failure, expected success or high probability of success. The algorithms are modified accordingly and to give more weight to the class that really matters. Note that this approach remains valid for any other classification problems for which the focus is on some extreme classes; e.g. fraud detection, credit default... Finally, simulations are conducted to measure the performances of the three methods, with and without the suggested adaptation. We check if the factors of success/failure we can identify are similar to those reported in the literature. We also make a ``what-if sensitivity analysis''. The goal is to measure in more depth the impact of some factors and the impact of some solutions, e.g., a complementary training or a reorientation

The effect on the macular function of laser photocoagulation for diabetic macular edema.

The benefit of focal and grid-laser photocoagulation in reducing the risk of visual loss from diabetic macular edema has been established. In order to investigate the effect of this treatment on macular function, 30 diabetics with macular edema and 1.0 visual acuity were tested before and after laser treatment at intervals of 1 week, and 1 and 3 months, respectively. The test was carried out by means of nyctometry, contrast sensitivity, hue discrimination and critical flicker frequency of blue cones. All patients had abnormal results in macular tests before treatment. During the follow-up, visual acuity remained stable and the macular tests did not statistically modify, except for nyctometry, which deteriorated at the 1-week follow-up (P = 0.02) and then increased to the basal values, and contrast sensitivity [improved at the last control (P = 0.006)]. Clinical regression of macular edema was observed, but macular function tests never normalized. Patients with diabetic macular edema and good visual acuity should be monitored with many functional methods, and laser treatment should be performed before macular function deteriorates irreversibly

Corneal confocal microscopy in patients with vernal keratoconjunctivitis

Abstract: Purpose: To compare corneal morphologic features using in vivo confocal microscopy in vernal keratoconjunctivitis (VKC) patients compared with normal subjects. Design: Prospective, comparative study. Participants: Thirty-two VKC patients (26 males, 6 females; mean age, 17.1 years) and 40 normal subjects (20 males, 20 females; mean age, 19.3 years) were included. Methods: All subjects underwent a full ophthalmologic examination. Confoscan CS4 (Nidek, Gamagori, Japan) images of the central cornea were obtained with a X40 noncontact lens and Z-ring device. Main Outcome Measures: The superficial and basal epithelium, subbasal nerve plexus, anterior stroma, stromal nerves, and endothelium of the central cornea were studied. Results: The VKC patients had increased diameter, reflectivity, and presence of nuclear activation of superficial epithelial cells; reduced density of the basal membrane; lower density of keratocytes, increased presence of activated keratocytes, and inflammatory cells in the anterior stroma; and lower density and number of fibers, lower number of beadings, and higher grade of tortuosity of fibers in the subbasal nerve plexus. Increased alterations in thickness, deflections, and tortuosity were observed in stromal corneal nerves. An increased number of inflammatory cells in close proximity to the subbasal and stromal nerve fibers also was observed in VKC subjects. Conclusions: Corneal involvement in VKC is associated with alterations of the epithelium and subbasal and stromal corneal nerves. These changes may relate to the tear dysfunction and nonspecific hyperreactivity typical of these patients. Corneal confocal microscopy is a useful tool for studying in vivo pathologic corneal changes in VKC. Ophthalmology 2012;119:509-515 (C) 2012 by the American Academy of Ophthalmology

Cytostatic and Cytotoxic Effects of 5-Fluorouracil on Human Corneal Epithelial Cells and Keratocytes.

PURPOSE:: To investigate the effects of various 5-fluorouracil (5-FU) concentrations, exposure times, and application techniques on in vitro-cultured human corneal cells. METHODS:: Human corneal epithelial cell (HCEC) and human corneal keratocyte (HCK) cultures were exposed to different 5-FU concentrations (0.025%-1%) and incubation durations (5 minutes to 2 hours). The cytostatic effect was evaluated as the percentage of inhibition of migration relative to the control. The evaluation of cytotoxic effect included both phase contrast microscopic observations and viability measures performed using an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] colorimetric assay. The results are expressed as ratio of optical density (OD) reduction 24 hours after exposure. RESULTS:: The cytostatic effect was time and dose dependent. The 50% inhibiting dose was 0.55% after 1 hour of incubation for HCECs and was 0.5% after 2 hours of incubation for HCKs. A 100% inhibitory effect was never observed at any concentration or incubation duration. No cytotoxic changes were observed using an 5-FU concentration of <1%; 1% 5-FU showed time-dependent cytotoxic changes in HCEC cultures only. MTT analysis showed no OD reduction at 5-FU concentrations of <1%, whereas 1% 5-FU showed OD reduction <50% at any tested exposure time. HCECs showed higher reduction in OD than HCKs. CONCLUSIONS:: 5-FU formulations topically used in clinical practice showed limited toxicity in normal cultured corneal epithelial cells and keratocytes

Effects of cyclosporin A on human conjunctival fibroblasts

objective: To evaluate the effects of cyclosporin A (CsA) on cytokine and/or collagen production, cell growth, and apoptosis in conjunctival fibroblast cultures. Methods: Fibroblast cultures derived from normal subjects and patients with vernal keratoconjunctivitis and pemphigoid were exposed to different concentrations of CsA for either 24 hours or 30 days. The effects were evaluated by the colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) test to assess cell proliferation, and by the measurement of procollagen I (PIP) and procollagen III (PIIIP) cytokines and total protein in culture medium. CsA-induced apoptosis was assessed by fluorescence-activated cell sorter analysis. Results: After 24 hours of exposure to doses of CsA of more than 10 mug/mL, cell proliferation and migration were significantly reduced. Cyclosporin A reduced PIP and interleukin 1 (IL-1) production in a dose-dependent manner. Interleukin 6 and IL-8 were increased by 10 mug/mL of CsA, whereas transforming growth factor P, PIIIP, and total protein were unaffected. Cyclosporin A exposure induced apoptosis in a time- and dose-dependent manner. Long-term exposure to CsA reduced IL-6 but did not modify PIIIP production. Conclusion: Exposure to CsA directly modified fibroblast behavior. Clinical Relevance: Cyclosporin A ability to accelerate apoptosis in clinically fibrotic tissues may prove to be therapeutic and useful in hyperproliferative conjunctival disorders

Effects of Th2 cytochines on expression of collagen, MMP-1 and TIMP-1 in conjunctival fibroblasts

Abstract PURPOSE: To determine whether cytokines involved in chronic allergic conjunctival disorders may affect formation of giant papillae and tissue remodeling. METHODS: Conjunctival fibroblast cultures were challenged with different concentrations of human recombinant interleukin (IL)-4, IL-13, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha. Procollagens I (PIP) and III (PIIIP), matrix metalloproteinase (MMP)-1 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants, and their respective mRNAs were evaluated by RT-PCR. RESULTS: IL-4 and -13 (10 ng/mL) significantly increased production and expression of PIP compared with nonstimulated cells, whereas IFN-gamma elicited the opposite effect, at both the protein and mRNA levels. Both IL-4 and -13 significantly decreased production of MMP-1 and increased that of TIMP-1, whereas TNF-alpha increased production of MMP-1 and -9. Expression of MMP-1 was reduced by IL-4 and increased by the other tested cytokines, whereas expression of TIMP-1 was increased by all tested cytokines. CONCLUSIONS: IL-4 and -13 increased production of collagen and modified the equilibrium between MMP-1 and its inhibitor, TIMP-1. These effects were partially opposed by IFN-gamma and TNF-alpha

In vitro effects of fluorochinolone and aminoglycoside antibiotics on human keratocytes

Abstract PURPOSE: The purpose of this study was to assess the cytotoxic effects of the fluoquinolone ofloxacin and the aminoglycoside netilmicin on stromal human keratocytes in vitro. METHODS: Cultured human keratocytes were exposed to various concentrations of ofloxacin or netilmicin (0.16-5.0 mg/mL). Both cell proliferation (MTT assay) and cell morphology (phase-contrast microscopy) were evaluated after 1, 4, 12, and 24 hours of incubation. Measurement of annexin V binding performed in association with the dye exclusion test using propidium iodide (PI) was also performed by FACS analysis after 4 hours of exposure. RESULTS: Both antimicrobials induced dose- and time-dependent morphologic changes in keratocytes, yet the effects of netilmicin were minimal. After 24 hours of exposure, both drugs induced a dose-dependent inhibition of cell proliferation; however, ofloxacin demonstrated significantly more toxic effects than netilmicin (t test for ED50 values, P < 0.0001). Statistical differences between 2 antibiotics start at concentrations above 1.25 mg/mL (ANOVA with post-hoc test, P < 0.01). Expression of the apoptotic marker annexin V was unaffected by antibiotic exposure, whereas the uptake of the necrotic marker PI was increased by ofloxacin (5 mg/mL) but not by netilmicin (ofloxacin versus netilmicin, ANOVA, P < 0.05). CONCLUSIONS: Relative effects of aminoglycosides and fluoroquinolones on stromal keratocytes appear to be different: netilmicin was shown to be significantly less toxic than ofloxacin. This finding is particularly relevant in deciding the optimal antibiotic to be applied in clinical situations in which the epithelium is absent or compromised, as after photorefractive keratectomy, alkali burns, or ulcerative keratiti