Corneal alkali burns are potentially blinding injuries. Alkali induces oxidative stress in corneas followed by excessive corneal inflammation, neovascularization, and untransparent scar formation. Molecular hydrogen (H2), a potent reactive oxygen species (ROS) scavenger, suppresses oxidative stress and enables corneal healing when applied on the corneal surface. The purpose of this study was to examine whether the H2 pretreatment of healthy corneas evokes a protective effect against corneal alkali-induced oxidative stress. Rabbit eyes were pretreated with a H2 solution or buffer solution, by drops onto the ocular surface, and the corneas were then burned with 0.25 M NaOH. The results obtained with immunohistochemistry and pachymetry showed that in the corneas of H2-pretreated eyes, slight oxidative stress appeared followed by an increased expression of antioxidant enzymes. When these corneas were postburned with alkali, the alkali-induced oxidative stress was suppressed. This was in contrast to postburned buffer-pretreated corneas, where the oxidative stress was strong. These corneas healed with scar formation and neovascularization, whereas corneas of H2-pretreated eyes healed with restoration of transparency in the majority of cases. Corneal neovascularization was strongly suppressed. Our results suggest that the corneal alkali-induced oxidative stress was reduced via the increased antioxidant capacity of corneal cells against reactive oxygen species (ROS). It is further suggested that the ability of H2 to induce the increase in antioxidant cell capacity is important for eye protection against various diseases or external influences associated with ROS production.

• MeSH
• alkálie toxicita   MeSH
• antioxidancia metabolismus   MeSH
• chemické popálení farmakoterapie   metabolismus   patologie   MeSH
• epitelové buňky účinky léků   metabolismus   patologie   MeSH
• hojení ran účinky léků   MeSH
• králíci MeSH
• modely nemocí na zvířatech MeSH
• neovaskularizace rohovky prevence a kontrola   MeSH
• oxidační stres účinky léků   MeSH
• popálení oka chemicky indukované   farmakoterapie   metabolismus   patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka krevní zásobení   účinky léků   metabolismus   patologie   MeSH
• vodík farmakologie   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• alkálie MeSH
• antioxidancia MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

Our previous research revealed that trehalose, a nonreducing disaccharide of glucose and an important stress responsive factor, proved to have anti-inflammatory, antiapoptotic, and particularly antioxidant properties in UVB-irradiated corneas. Trehalose reduced oxidative stress in corneas induced by UVB irradiation, by means of a decrease in the antioxidant/prooxidant imbalance in the corneal epithelium. In this study, we demonstrate that trehalose of 3% or 6% concentration in eye drops directly decreases oxidative stress in UVB-irradiated corneas, by removing the excessive amount of reactive oxygen species (ROS). Trehalose drops applied on corneas during UVB irradiation once daily for four days resulted in a reduction or even absence of the oxidative stress, DNA damage, and peroxynitrite formation (detected by nitrotyrosine residues), seen in buffer-treated corneas. Furthermore, trehalose treatment applied curatively after repeated irradiation for the subsequent fourteen days led to the renewal of corneal transparency and significant suppression or even absence of neovascularization. This was in contrast to buffer-treated irradiated corneas, where the intracorneal inflammation was developed and the untransparent corneas were vascularized. In conclusion, the treatment of UVB-irradiated corneas with trehalose eye drops removed the excessive amount of ROS in the corneal epithelium, leading to the suppression of oxidative stress and favorable corneal healing. The 6% trehalose showed a higher intensive antioxidant effect.

• MeSH
• hojení ran účinky léků   účinky záření   MeSH
• interleukin-1beta metabolismus   MeSH
• keratiny metabolismus   MeSH
• králíci MeSH
• oxidační stres * účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   MeSH
• poškození DNA MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• reepitalizace účinky léků   účinky záření   MeSH
• rohovka účinky léků   patologie   účinky záření   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• trehalosa farmakologie   terapeutické užití   MeSH
• tyrosin analogy a deriváty   metabolismus   MeSH
• ultrafialové záření * MeSH
• vaskulární endoteliální růstový faktor A metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• 3-nitrotyrosine MeSH Prohlížeč
• interleukin-1beta MeSH
• keratiny MeSH
• reaktivní formy kyslíku MeSH
• synthasa oxidu dusnatého, typ II MeSH
• trehalosa MeSH
• tyrosin MeSH
• vaskulární endoteliální růstový faktor A MeSH

Trehalose, a disaccharide of glucose, is a naturally occurring nontoxic and nonreducing bioactive sugar. Trehalose is synthetized by many organisms when cells are exposed to stressful conditions, including dehydration, heat, oxidation, hypoxia or even anoxia. Although trehalose is not synthesized by mammalian cells, it has recently been demonstrated to have a number of important properties that indicate its utility in humans. Trehalose enables wound healing by protecting cells, especially cell membranes, from oxidative injury and dessication. When the injured cornea is treated with trehalose, corneal inflammation, scar formation and corneal neovascularization are suppressed. In dry eye disease, trehalose decreased cell apoptosis and reduced oxidative, inflammatory and proteolytic activity at the ocular surface. In UVB irradiated cornea, trehalose suppressed photodamage evoked by UVB rays. It decreased the intracorneal inflammation and reduced corneal neovascularization. Trehalose prevented postoperative fibrous scar formation after ocular surgery, such as glaucoma filtration surgery. The non-toxicity of trehalose allows its administration in humans for extended periods and enables its use in various disease states.

• MeSH
• antiflogistika chemie   farmakologie   MeSH
• antioxidancia chemie   farmakologie   MeSH
• apoptóza * MeSH
• hojení ran * MeSH
• klinické zkoušky jako téma MeSH
• králíci MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• oftalmologie MeSH
• oxidační stres * MeSH
• rohovka účinky léků   účinky záření   MeSH
• syndromy suchého oka farmakoterapie   MeSH
• trehalosa chemie   farmakologie   MeSH
• ultrafialové záření MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antiflogistika MeSH
• antioxidancia MeSH
• trehalosa MeSH

The aim of this study is to examine whether molecular hydrogen (H2) is able to reduce oxidative stress after corneal damage induced by UVB irradiation. We previously found that UVB irradiation of the cornea caused the imbalance between the antioxidant and prooxidant enzymes in the corneal epithelium, followed by the imbalance between metalloproteinases and their physiological inhibitors (imbalances in favour of prooxidants and metalloproteinases) contributing to oxidative stress and development of the intracorneal inflammation. Here we investigate the effect of H2 dissolved in PBS in the concentration 0.5 ppm wt/vol, applied on rabbit corneas during UVB irradiation and healing (UVB doses 1.01 J/cm2 once daily for four days). Some irradiated corneas remained untreated or buffer treated. In these corneas the oxidative stress appeared, followed by the excessive inflammation. Malondiladehyde and peroxynitrite expressions were present. The corneas healed with scar formation and neovascularization. In contrast, in H2 treated irradiated corneas oxidative stress was suppressed and malondiladehyde and peroxynitrite expressions were absent. The corneas healed with the restoration of transparency. The study provides the first evidence of the role of H2 in prevention of oxidative and nitrosative stress in UVB irradiated corneas, which may represent a novel prophylactic approach to corneal photodamage.

• MeSH
• králíci MeSH
• kyselina peroxydusitá metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• oxidační stres účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka účinky léků   metabolismus   účinky záření   MeSH
• ultrafialové záření * MeSH
• vodík terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• kyselina peroxydusitá MeSH
• malondialdehyd MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

INTRODUCTION: Corticosteroid therapy is very beneficial in many types of eye diseases. Corticosteroids are used in the treatment of inflammatory and immunological diseases of the eye. PURPOSE: The aim is to present basic informations about effects of steroids in tissues, their side effects and treatment strategy. METHODS AND RESULTS: Authors process overview of local and systemic steroids and their dosage forms. They refer to the most common problems associated with corticosteroid therapy. CONCLUSION: Although corticosteroids include medicine across to one of the most frequently prescribed drugs at all, it is always necessary to treat very carefully indicate any corticosteroid preparation and prior to its administration to eliminate all infectious diseases, take a thorough anamnesis and complete examine the patient.Key words: cornea, corneal healing, inflammatory cascade, corticosteroids.

• MeSH
• aplikace inhalační MeSH
• glukokortikoidy * škodlivé účinky   terapeutické užití   MeSH
• hormony kůry nadledvin MeSH
• lidé MeSH
• nemoci rohovky * farmakoterapie   MeSH
• rohovka * účinky léků   MeSH
• steroidy MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• glukokortikoidy * MeSH
• hormony kůry nadledvin MeSH
• steroidy MeSH

Changes in the biomechanical properties of the human cornea play an important role in the pathogenesis of corneal ectatic diseases. Many different pathological conditions in the cornea may reduce its biomechanical resistance. Corneal collagen cross-linking (CXL) has emerged as a promising technique to slow or even to stop the progression of ectasia. In this procedure, riboflavin (vitamin B2) is administered in conjunction with ultraviolet A light (UVA, 365 nm). This interaction causes the formation of reactive oxygen species, leading to additional covalent bonds between collagen molecules, with consequent biomechanical stiffening of the cornea. Although this method is not yet accepted as an evidence-based treatment of corneal ectasia, the results of prospective, randomised studies of CXL used in the treatment of this pathological entity show significant changes in the properties of corneal tissue. This procedure is currently the only aetiopathogenetic treatment of ectatic eyes that can delay or stop the process of cornea destabilisation, reducing the necessity for keratoplasty. Despite promising results, CXL is associated with issues that include long-term safety and duration of the stabilising effect.

• MeSH
• fotochemoterapie metody   MeSH
• fotosenzibilizující látky aplikace a dávkování   MeSH
• keratokonus farmakoterapie   MeSH
• lidé MeSH
• medicína založená na důkazech MeSH
• reagencia zkříženě vázaná účinky záření   MeSH
• riboflavin aplikace a dávkování   MeSH
• rohovka účinky léků   účinky záření   MeSH
• terapie ultrafialovými paprsky metody   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• fotosenzibilizující látky MeSH
• reagencia zkříženě vázaná MeSH
• riboflavin MeSH

The Purpose of present study was to investigate the effect of riboflavin/ultraviolet-A-induced collagen cross-linking (CXL) on central cornea, limbus and intraocular pressure (IOP). This was an animal experimental study. The right corneas of 10 rabbits were ultraviolet-A irradiated (3 mW/cm2 for 30 minutes) after de-epithelialization and instillation of 0.1% riboflavin / 20% Dextran drops. Left corneas served as controls. Samples were examined histologically one month postoperatively. Before and after treatment, IOP measurements were recorded bilaterally. At central cornea of eyes underwent CXL keratocyte repopulation, normal arrangement of collagen fibres and a statistically significant change in fibres diameter were detected, compared to controls. At limbus area, there were not any significant histological differences after CXL. There was no statistically significant difference between pre- and postoperative IOP in all eyes.

• Klíčová slova
• Cornea, Corneal Crosslinking, Intraocular pressure, Limbus,
• MeSH
• fotosenzibilizující látky farmakologie   MeSH
• kolagen chemie   ultrastruktura   MeSH
• králíci MeSH
• limbus corneae účinky léků   účinky záření   chirurgie   ultrastruktura   MeSH
• nitrooční tlak * účinky léků   účinky záření   MeSH
• reagencia zkříženě vázaná farmakologie   MeSH
• riboflavin farmakologie   MeSH
• rohovka účinky léků   účinky záření   chirurgie   ultrastruktura   MeSH
• ultrafialové záření * MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fotosenzibilizující látky MeSH
• kolagen MeSH
• reagencia zkříženě vázaná MeSH
• riboflavin MeSH

Two modifications of the rinsing procedure within the BCOP assay were proposed. Their ability to enhance the removal efficiency of highly viscous and colored samples was compared with an unmodified BCOP procedure (TG OECD 437). The first modification consisted of three-step washing of the applied chemicals from the cornea using Eagle's Minimum Essential Medium (EMEM), olive oil and EMEM, while the classical OECD TG 437 procedure prescribes only EMEM. Within the second modification, mechanical removal of the tested sample from the cornea surface prior to the two step washing procedure was performed. The in vitro irritation score (IVIS) exceeded the value of 55 for 9 out of 20 samples when a non-modified rinsing procedure was used. The first modification with the olive oil resulted in a decrease in IVIS for numerous samples, while an IVIS score drop below the threshold value of 55 was only observed for two of them. Mechanical removal of sample residua resulted in a further decline in the measured IVIS. Only the three samples treated by means of this procedure revealed an IVIS above 55. The decreases in IVIS observed during both modifications were mainly related to the reduced opacity, whereas the permeability mostly remained unaffected.

• Klíčová slova
• BCOP, Oils, Rinsing procedure, Viscous samples, Waxes,
• MeSH
• alternativy testů na zvířatech MeSH
• barva MeSH
• biotest metody   MeSH
• dráždivé látky toxicita   MeSH
• olivový olej MeSH
• permeabilita MeSH
• rohovka účinky léků   metabolismus   MeSH
• skot MeSH
• techniky in vitro MeSH
• viskozita MeSH
• zákal rohovky * MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dráždivé látky MeSH
• olivový olej MeSH

Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown.

• MeSH
• alkálie toxicita   MeSH
• oční roztoky terapeutické užití   MeSH
• oxidační stres * účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   metabolismus   patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka účinky léků   účinky záření   MeSH
• ultrafialové záření MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• alkálie MeSH
• oční roztoky MeSH
• reaktivní formy kyslíku MeSH

OBJECTIVES: Malathion is generally not classified as toxic. However, the toxicity seems to be species-dependent. Local and systemic toxicity data for birds are rare, but a decrease of wild bird densities in areas where malathion was applied was reported. Aim of the study was to extend knowledge on malathion toxicity on cellular and organ level and to evaluate embryotoxicity and genotoxicity for birds using the chick embryo model HET-CAM. METHODS: Skin and eye irritation was determined using reconstructed skin and eye cornea tissues and the chorioallantoic membrane of chick embryo to simulate conjunctiva. Cytotoxicity in 3T3 Balb/c fibroblast culture was determined to estimate acute systemic toxicity. Chick embryo model was further employed to evaluate acute embryotoxicity for birds (mortality and genotoxicity). Data were analysed by means of general linear models. RESULTS: Malathion is not a skin and eye irritant. Cytotoxicity in vitro test provided LD50 value of 616 mg/kg suggesting higher toxic potential than is generally published based on in vivo tests on laboratory rodents. Embryotoxicity studies revealed dose and age dependent mortality of chick embryos. Genotoxicity was identified by means of micronucleus test in erythroid cells isolated from chorioallantois vascular system of chick embryos. CONCLUSIONS: Using in vitro alternative toxicological methods, a higher toxic potential of malathion was demonstrated than is generally declared. An increased health and environmental hazard may occur in areas with intensive agricultural production. The environmental consequences of delayed effects and embryotoxicity for bird populations in areas exposed to organophosphate insecticides, such as malathion, are obvious.

• MeSH
• biologické modely MeSH
• buňky BALB 3T3 cytologie   účinky léků   MeSH
• chorioalantoická membrána cytologie   účinky léků   MeSH
• dráždivé látky toxicita   MeSH
• druhová specificita MeSH
• embryo nesavčí cytologie   účinky léků   MeSH
• insekticidy toxicita   MeSH
• kur domácí MeSH
• kuřecí embryo MeSH
• lineární modely MeSH
• malathion toxicita   MeSH
• mitóza účinky léků   MeSH
• myši MeSH
• rohovka cytologie   účinky léků   MeSH
• techniky in vitro MeSH
• testy akutní toxicity MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dráždivé látky MeSH
• insekticidy MeSH
• malathion MeSH