No description available.

No description available.

No description available.

This work used <i>Pax6</i>^+/- mice as a model for Pax6-realted corneal diseases and assessed the roles of oxidative stress and epithelial injury in the aetiology of ARK. Histological investigation revealed epithelial lesions in <i>Pax</i>6^+/- corneas. Proteomic analysis demonstrated reduced levels of protective enzymes, transketolase, aldehyde dehydrogenase 3A1 and glutathione S-transferase α4, and cytoskeletal proteins. Keratin 5 and 12 in <i>Pax</i>6^+/- adult mouse corneas. These physical/structural and chemical defects imply that <i>Pax</i>6^+/- corneas may be in a chronic ‘stressed and wounded’ state. Using a DNPH/protein oxidation assay, <i>Pax</i>6^+/- corneal protein oxidation was found to be consistently higher than that in <i>wild-type</i> (WT), and to get worse with age, in parallel with the development of corneal opacity. H₂O₂ was used to induce oxidative stress in mouse corneas and this was found to activate the Ca²⁺ (protein kinase C/ phospholipase C) → p38/p42/p44 mitogen activated kinase signalling pathway. Oxidative stress-induced Pax6 exclusion form cell nucleus led to abnormal expression of non-corneal epithelial markers, indicating a metaplasia process that may cause normally transparent epithelial cells to become opaque. This report for the first time describes cytoskeleton architectures <i>in vivo</i> using flat-mount mouse corneal epithelial by fluorescent staining and confocal microscopy, which is potentially applicable to studies interested in cytoskeleton <i>in vivo</i>. Keratin, desmoplakin and actin cytoskeletal structures were found to be heterogeneous and defective in <i>Pax</i>6^+/- cells. Twenty-one hours after wounding WT corneal epithelia <i>in vivo</i>, healing cells developed desmoplakin and actin structural features, intercellular gaps, interdigitated filopodia-like processes and vesicles similar to the unscratched <i>Pax</i>6^+/- corneal epithelia. These data support the hypothesis of a ‘chronic wounded’ state in apparently uninjured <i>Pax</i>6^+/- corneal epithelia and reveal the cytoskeletal origins of poor adhesion and cellular structure.

The increasing occurrence of diabetes in the general population as a result of over nutrition and increasingly inactive lifestyle has led to an obesity epidemic which is set to grow over time. With an ever increasing obese population type 2 diabetes and cardiovascular complications are set to become the major causes of human mortality. Chronic non healing wounds are a major cause of mortality and morbidity in patients with type 2 diabetes. They are predominantly caused by macrophage dysfunction and a lack of migration of fibroblasts into the wound. This study aimed to investigate diabetic wound healing through development of an artificial scratch assay. An in vitro scratch assay developed in WS1 cells. The effect of heat shock treatments from 39°C to 45° was tested to determine if cell migration increased; however, no significant difference was seen. Mitomycin C was used to determine if wound closure occurred as a result of cell proliferation and migration or migration alone. 10μg/ml of mitomycin C inhibited cell division by 79.9% without exhibiting cytotoxicity over a 12h period. The effect of hyperglycaemia and heat shock was also tested and showed no significant difference when compared to control conditions, suggesting that fibroblast migration in vivo is hindered through other factors such as debridement or macrophage dysfunction in the wound. GLUT4 is present in insulin sensitive organs (liver, adipose and muscle) and is the major glucose transporter responsible for the clearance of glucose from the blood after a meal, thus playing a central role in glucose homeostasis. Monocytes are precursors to macrophages and can easily be isolated from whole blood. They have also been shown to express GLUT4 in response to insulin and could be used as model to assess inflammation in diabetes. A glucose uptake assay was developed in U937 cells using a fluorescent glucose analogue, 2NBDG. 2NBDG fluorescence was shown to be competitively inhibited by increasing concentrations of glucose suggesting that 2NBDG enters the cell through glucose transporters. 2NBDG uptake was also assessed at different pH and in presence of membrane fluidizers (DMSO, benzyl alcohol and phenethyl alcohol). Extremes of pH significantly reduced cell viability and only at pH 4 was 2NBDG fluorescence significantly reduced. Treatment with DMSO showed that at high concentrations (≤ 1.56%) cell viability was reduced with a concurrent reduction in 2NBDG fluorescence. The effect of benzyl alcohol and phenethyl alcohol was foundto be insignificant at the concentrations and time points tested. The presence of GLUT4 was also determined by flow cytometry and Western blotting and found to be situated in the cytoplasmic region of the cell. This study indicates that monocytes and macrophages could be a potential therapeutic target to improve diabetic wound healing as they are a source of growth factors and cytokines that can bring about resolution of inflammation and it is their dysfunction in diabetic wounds that causes poor clinical outcomes.

No description available.

Wound healing is a dynamic process that ultimately leads to restoration of tissue integrity and function. The pineal gland hormone melatonin is known for its anti-oncotic, anti- inflammatory and immuno-modulatory effects. However, its role in wound healing has not been established. Since melatonin is synthesised endogenously, we primarily sought to investigate whether the melatonin receptors played a role in the wound healing process. Using immunohistochemical methods and Western blot analysis we observed that MT₁ was normally absent in the rat skin but was strongly expressed on day 1 to day 3 post wounding in the epidermis adjacent to the wound edge. MT₁ expression was restricted to the stratum granulosum and stratum spinosum layers of the epidermis in the rat wounds. MT₁ expression declined thereafter and became nonexistent by day 21 when the wound had completely healed. In contrast, MT₂ was constitutively expressed in all the layers of the normal rat epidermis. MT₂ expression gradually decreased at the injury site following wounding but returned to the normal profile by day 21. Aged rat epidermis showed similar MT₁ and MT₂ expression as adult rats. The profile of tissue distribution of MT₁ and MT₂ in the human epidermis was comparable to the rat epidermis. In the CVUs MT₁ and MT₂ localisation profiles resembled that of a healing wound, akin to a day 1 or day 3 rat dermal wound, during the inflammatory phase. Surprisingly, in contrast to all the tissues investigated, MT₁ was also localised in the stratum basale layer of the keloid epidermis. MT₂ localisation in the same keloid tissues however resembled normal human skin profiles. Secondly, we determined the effects of exogenously administered melatonin, on scarring and wound healing, using a full thickness incisional model of wound healing in rats. Melatonin treatment significantly improved the quality of scarring by day 21. However, our findings would have been strengthened by a more explicit wound closure analysis, measurement of granulation tissue weight, tensile strength, hydroxyl proline content and immunohistochemical assessments of neutrophil infiltration, macrophages, fibroblasts, myofibroblasts and reepithelialization. The treatment also accelerated the angiogenic process and enhanced the VEGF protein profile. Arginase generates proline, the building block for collagen synthesis. Melatonin treatment increased arginase activity and consequently would increase collagen synthesis from day 1. An increase in NOS activity and therefore NO production is known to be detrimental during inflammation. However, various studies have also shown that the NO is essential for granulation tissue formation. Melatonin treatment significantly decreased iNOS activity during the acute inflammatory phase in this study, but significantly increased iNOS activity during the resolving phase. Other markers of inflammatory response and repair were also examined in this study. COX-2 has been shown to play an anti-inflammatory role and melatonin increased COX-2 activity and protein following wounding. SOD (the antioxidant enzyme) activity was also significantly increased during the chronic inflammatory phase on melatonin administration. HO-1 and HO-2 isoforms have also been previously demonstrated to participate in the repair process. Melatonin treatment increased up-regulation of both HO-1 and HO-2 protein expression in the wounded skin. A significant decrease in all the mitochondrial enzyme activities (except complex-II-III), was observed post wounding. Melatonin treatment restored the complex activities to near normal levels. Melatonin also protected mitochondrial membrane integrity and reduced oxidative stress as evidenced by the maintained level of aconitase and citrate synthase activities at near normal levels. In vitro experiments using macrophage and fibroblast cell lines illustrated that melatonin may decrease NOS activity and protein profiles indirectly by stimulating arginase activity and thereby depleting the availability of arginine. This study is the first to fully demonstrate the distribution of melatonin receptors in normal and abnormal wounds. Improvement in the quality of scarring in a rat model of wound healing on melatonin administration is promising but much more quantitative work and preclinical studies are required before melatonin advances into clinical assessment.

<p>Sår är ett stort problem som medför lidande för patienten, är tidskrävande och medför stora kostnader för sjukvården. Nutrition är livsnödvändigt och en rätt sammansatt kost är viktig för att kroppen ska må bra och fungera väl. Sår och nutrition ligger inom sjuksköterskans ansvarsområde och därför är det av stor vikt att beskriva näringsämnens och nutritionssupplements inverkan på sårläkning. Syftet med denna studie var att beskriva nutritionens betydelse för sårläkning. Studien genomfördes som en deskriptiv litteraturstudie där vetenskapliga artiklar sökts i tidskrifter. Dessa tidskrifter har haft orden nutrition, wound eller nursing i tidskriftens namn. Resultatet, baserat på 13 vetenskapliga artiklar, visar att nutrition har betydelse för sårläkning. I alla studier har en signifikant förbättrad sårläkning påvisats genom nutrition utom i en studie där ett signifikant samband inte fanns men där en trend sågs som antydde på samband. I alla studier som använt sig av nutritionssupplement har en förbättrad sårläkning påvisats, men då flertalet studier innefattar många olika näringsämnen är det svårt att avgöra vilka av dessa som enskilt påverkar sårläkningen.</p>

Epithelial wound healing is a common occurrence in many organisms. In spite of a long history of study in this field, we do not have a complete understanding of the molecular and cellular mechanisms of wound healing, which is a key element to appreciate in order to modulate this process for better clinical outcomes. Optimal outcomes are especially critical in the cornea as a failure to regenerate can result in blindness and a huge decline in quality of life. Matrix Metalloproteinases (MMPs) are a family of zinc dependent proteases that have been shown to be both regulators and effectors of the corneal wound healing process. Strict regulation of MMP-9, the most extensively studied member of the MMP family, has been shown to be critical for efficient wound regeneration. While we now know that MMP-9 is important, and we even have evidence defining some of the roles it plays in the corneal wound healing process, the mechanism by which MMP-9 is regulated is still under debate. Possible extracellular regulatory mechanisms range from cell-cell interactions to cell-matrix interactions to secreted factors. However, the detailed mechanism of events that takes place on the extracellular surface and the downstream signals that mediate MMP-9 are unknown. Therefore, one of the objectives of the presented work is to define the external mechanisms which mediate MMP-9 expression in resurfacing epithelial cells and to link these external signals to internal signaling pathways in vitro. Furthermore, while MMP-9 acts to slow the resurfacing phase of wound healing, other MMPs seem to cause opposing effects. The second objective of the presented work is to provide the first global spatial and temporal MMP expression profile for an in vivo epithelial wound healing scenario and to define possible macroscopic roles of these heretofore unknown MMPs. Finally, this thesis will look at the expression of many MMP family members in a penetrating model which is an increasingly more common wound scenario due to the increase in corrective surgery. The final objective is to examine human post-LASIK corneas and correlate MMP expression with age, post-operative time, or histopathological abnormalities. The knowledge obtained from all aspects of these studies will contribute to the current understanding and knowledge about the roles and regulatory mechanisms of MMPs in the corneal wound healing process.

Sår är ett stort problem som medför lidande för patienten, är tidskrävande och medför stora kostnader för sjukvården. Nutrition är livsnödvändigt och en rätt sammansatt kost är viktig för att kroppen ska må bra och fungera väl. Sår och nutrition ligger inom sjuksköterskans ansvarsområde och därför är det av stor vikt att beskriva näringsämnens och nutritionssupplements inverkan på sårläkning. Syftet med denna studie var att beskriva nutritionens betydelse för sårläkning. Studien genomfördes som en deskriptiv litteraturstudie där vetenskapliga artiklar sökts i tidskrifter. Dessa tidskrifter har haft orden nutrition, wound eller nursing i tidskriftens namn. Resultatet, baserat på 13 vetenskapliga artiklar, visar att nutrition har betydelse för sårläkning. I alla studier har en signifikant förbättrad sårläkning påvisats genom nutrition utom i en studie där ett signifikant samband inte fanns men där en trend sågs som antydde på samband. I alla studier som använt sig av nutritionssupplement har en förbättrad sårläkning påvisats, men då flertalet studier innefattar många olika näringsämnen är det svårt att avgöra vilka av dessa som enskilt påverkar sårläkningen.