Keloids are classically regarded as scars that `outgrow the boundary of the original injury'. Ambiguous data concerning certain characteristics of keloid fibroblasts (such as proliferation rates and collagen production), however, have served only to confuse researchersT. he lack of an in vivo model and of detailed clinical accounts are added problems. In this study, a murine granulomatous tissue resolution model was used to investigate the profile of a number of cytokines suspectedto be involved in the aetiology of keloids. The results obtained from these experiments were then extrapolated to clarify the observations made in keloids. The results of these extrapolated comparisons revealed elevated levels of interleukin (IL)-4, IL-10, vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF) and transforming growth factor beta (TGF)-ß in keloid samples and decreasedle vels of interferon (IFN)-y and IL-2. The murine model was also used to investigate the implications of the low levels of IFN-y known to be present in the serum of keloid patients and shown here to be present in clinical samples. The results were found to support the hypothesis that the addition of IFN-y reduces the fibrosis so typical of keloids by rectifying the abnormality of the absence of IFNy content. The same model was used to provide evidence that the inhibition of VEGF activity in resolving wounds may halt the development of keloid lesions. The immunohistochemical profiles of cellular proliferation, apoptosis, lymphokines and cytokines for resolution (and, to a certain extent, the model) were used to compare with the abnormally resolved wounds which were available as clinical samples. Immunohistochemistry was also employed to describe the cellular nature of the clinical tissue samples in detail and to facilitate the development of the following hypothesis for keloid formation and propagation: lymphocytes migrate to the site of an (alleged) endogenous antigen present in the skin. The nature of these lymphocytes is characteristic of a type 2 immune response, they produce IL-4 (and IL-10) which in turn inhibit(s) the production of IFN-y and IL-2. Aside from this immunological response, wound resolution is taking place: fibroblasts are producing PDGF, EGF and TGF-ß to aid matrix remodelling and collagen synthesis. The provisional matrix is being vascularised by the action of VEGF, to allow the replenishment of nutrients; regression of blood vessels occurs through the action of an apoptosis-dependent mechanism, as does the 'normalisation' of fibroblastic populations. The keloid scar continues to grow after the cessation of resolution because the immune response to the 'endogenous' antigen continues and the lymphocytes continue to migrate to the site of the wound and continue to stimulate fibroblast proliferation and collagen production through the release of IL-4.

Orientador: Lucilene Delazari dos Santos / Coorientador: Luciana Patricia Fernandes Abbade / Resumo: Introdução: Úlceras venosas crônicas atingem até 4% da população mundial >65 anos, causando impacto socioeconômico, principalmente relacionado à diminuição da mobilidade e autoestima. O exsudato destas lesões, pode ser útil na identificação dos fatores envolvidos na reparação tecidual. Objetivos: Identificar proteínas expressas no exsudato de úlceras venosas, agrupando-as de acordo com suas principais funções, e correlancionando-as com variaveis clínicas e epidemiológicas. Métodos: Estudo clínico do tipo transversal, descritivo e analítico envolvendo trinta e sete úlceras de 28 pacientes. Todos os pacientes foram submetidos à questionário clínico-epidemiológico auto descritivo, análise de área e a coleta de exsudato das úlceras. Fluidos das lesões foram submetidos à digestão tríptica em solução e sequenciados por espectrometria de massas para identificação do perfil proteômico. A análise multivariada entre dados clínicos e expressão proteica do exsudato foi explorada por escalonamento multidimensional, a partir da distância euclidiana entre as variáveis. Resultados: A maioria dos pacientes era do sexo feminino (62%), com idade média de 70(±10.1) anos, relatando adesão à compressão e ao repouso, histórico de varizes primárias e hipertensão arterial sistêmica, apresentando tecido desvitalizado no leito da ferida e tempo de evolução >10 anos. Foram identificadas 74 proteínas no exsudato, agrupadas de acordo com sua principal função na cicatrização. O perfil proteômico evidenciou... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: not available / Mestre

Orientador: Rosemary Adriana Chiérici Marcantonio / Resumo: O objetivo desse estudo foi avaliar o efeito de uma membrana de látex natural sobre a cicatrização de feridas no palato duro provenientes da remoção de enxerto gengival livre. Vinte e quatro pacientes participaram desse estudo e foram divididos aleatoriamente em 2 grupos de acordo com o tratamento utilizado para proteger o leito doador: Grupo controle (GC): A ferida foi recoberta com placa acrílica associada ao cimento cirúrgico (n=14); Grupo Látex (GL): A ferida foi recoberta com placa acrílica associada a membrana de látex natural (n=10). Foram realizadas tomadas fotográficas padronizadas das regiões das feridas nos períodos de baseline, 3, 7, 15 e 30 dias após o procedimento cirúrgico. Um examinador cego e calibrado realizou avaliação clínica, levando se em consideração os parâmetros: 1) fechamento de ferida; 2) área de superfície epitelizada por meio da utilização da água oxigenada aplicada na região; 3) Avaliação do auto relato de sensação dolorosa por meio da aplicação da escala de dor VAS. Os resultados obtidos mostraram que em ambos os grupos, houve diminuição gradativa da área da ferida cirúrgica, sendo que a partir dos 15 dias essa era inexistente para todos os pacientes avaliados e em relação à dor houve uma redução significativa da sensibilidade dolorosa relatada pelos pacientes do grupo látex em relação ao grupo controle. O uso da membrana de látex não promoveu efeito adicional a cicatrização, apresentando os mesmos resultados clínicos que a utilização de cimento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this project was to evaluate the effect of a natural latex membrane in wound healing on donor sites of free gingival grafts. Twenty-four patients were used in this study and were randomly divided in 2 groups according with the treatment used to protect the donor site: Control group (CG) – Donor site was covered with an acrylic plate associated with surgical cement (n=14); Látex group (LG) – Donor site was covered with acrylic plate associated with a natural latex membrane and surgical cement (n=10). At baseline, 3, 7, 15 and 30 days after surgery, standardized photos of the wound were taken. A blind and calibrated examiner made the clinical evaluation by considering the parameters: 1) total wound area; 2) epithelized surface area through the use of hydrogen peroxide applied in the region; 3) Evaluation of self-report of pain sensation through the application of the VAS pain scale. The achieve results showed that both groups had a gradual decrease in the area of the surgical wound, and from 15 days this was non-existent for all patients evaluated and on the pain avaliation we found that the patients in latex group had significant reduction in reported pain when compared to the control group. The use of natural latex membrane didn’t promote any additional effect for wound healing, showing the same clinical results as the use of surgical cement with the addition of a lower pain report by the patients. / Mestre

The Ectodysplasin/Ectodysplasin receptor (Eda/Edar) signalling pathway is critical during development for the formation of skin appendages. However, its roles during adulthood are only recently being elucidated. Adult appendages, such as hair follicles (HFs), are known to become activated to respond to cutaneous injury. However, the HF houses distinct cell populations that display differing capacities to participate and persist in re-epithelialisation. We show, contrary to previous findings, that the best-characterised stem cell (SC) niche within the HF (the bulge) does not respond to injury during the earliest stages of wound healing. We propose that bulge SCs are prevented from participating in early repair as a protection mechanism against tumourigenesis. Despite the bulge niche not participating in early repair, we found the upper HF outer root sheath (ORS) to respond rapidly to injury. Our investigation into the role of Eda/Edar signalling during wound healing revealed that activation of the pathway was able to specifically induce proliferation within this portion of the HF. We further demonstrate a number of roles for the Eda/Edar pathway during adult wound healing, including, surprisingly, influencing several wound responses within the dermis. Specifically, an absence of Eda/Edar signalling in Tabby mice results in delayed wound healing, whereas acute activation of the pathway in wild-type (WT) mice can stimulate re-epithelialisation and enhance wound repair. These effects also translate to a model of human wound healing, where activation of Eda/Edar signalling accelerates re-epithelialisation and increases peri-wound proliferation. RNA-seq analysis reveals diverse gene regulation in the presence/absence of Eda/Edar signalling. Overall, these findings suggest that manipulation of the Eda/Edar pathway may represent an attractive potential therapeutic for enhancement of wound repair, potentially through maximising the natural growth capacity of peri-wound HFs.

Patients who suffer from severe joint destruction caused by arthritis often undergo total joint arthroplasty (TJA). A major limitation of this treatment and common long-term complication is the development of aseptic loosening of the prosthesis in as many as 20% of patients. The current paradigm to explain aseptic loosening proposes that wear debris generated from the prosthesis initiates a macrophage-mediated inflammatory response by resident macrophages, leading to osteoclast activation and bone resorption at the implant interface. This can then lead to the development of a peri-prosthetic fracture. The principal aim of fracture healing is to restore the bone to its original form and strength. However, this ultimate goal can be altered if the healing is impaired. This impairment may be due to bone disease (osteoporosis) or even the introduction of a foreign material such as PE wear debris that could have migrated from the articulating surface to the fracture site. A standard closed unilateral fracture of the right femur was performed in both normal and oestrogen deficient rats following fixation with a k-wire. Ceridust (PE wear debris) was combined with hyaluronic acid and saline and injected directly into the fracture site. Femurs were assessed using radiographs, histology and immunohistochemistry. Histological analysis revealed that complete remodelling was achieved in all control groups by 6 weeks post-fracture with mechanical strength returning to normal values. The mechanical properties of the fractures were not influenced by the presence of PE wear debris in the dose and timing examined. Histology and immunohistochemistry however, did reveal a local effect of the presence of PE wear debris. The histology adjacent to the PE particles was inferior to the controls but did not manifest itself in a reduction in the mechanical properties except in the oestrogen deficient bone at 6 weeks post-fracture. The levels of MMP-1 and TNF-?? correlated to the presence of PE particles. In this thesis, I have shown the mechanism by which bone remodelling in fracture healing could be retarded due to the presence of PE wear debris, by increased matrix degradation in both normal and oestrogen deficient animals.

Transglutaminase II (TG2) is a complex protein with five different reported activities. Increases in TG2 expression and TGase activity have previously been observed during wound healing in rat studies; however, it has been unclear whether these phenomena were directly involved in the healing process or if they were simply a by-product of it. The aims of this thesis were, thus, to determine if TG2 plays a role in wound healing in vivo and to elucidate the mechanism of any effects TG2 may have at the cellular level. TG2 ablation resulted in delayed wound healing. To gain mechanistic insight into this abnormality, primary fibroblast cultures from TG2-knockout and wildtype mouse embryos were analysed. TG2-null fibroblasts displayed decreased adhesion and integrin signalling during initial stages of adhesion. Intriguingly, TG2-null cells showed faster activation of Rac1 and RhoA in response to adhesion. Long-term adhesion of TG2-null fibroblasts resulted in increased basal phosphorylation of FAK and number of paxillin-stained focal adhesions, enhanced PI3-kinase signalling, faster actin dynamics and altered activation of p44/42 MAPK. These results are indicative of futile cycling of intracellular signalling pathways resulting from reduced focal adhesion turnover in the TG2-knockout fibroblasts. Rescue experiments demonstrated that TG2-mediated effects on cell adhesion occurred in the extracellular environment and that neither GTP-binding nor TGase activity is required for these effects. Results further showed that a ???compact??? conformation of TG2 was not required for this role of TG2. Interestingly, addition of recombinant TG2 to the extracellular environment increased cell spreading of TG2-null cells to a level far greater than that seen in wildtype cells, which did not increase their spreading in response to exogenous TG2. Demonstration of faster activation of the small GTPases in the TG2-null MEFs, and the apparent inhibition of exogenous TG2???s extracellular effects on cell spreading by endogenous protein in the wildtype cells, provide tantalising evidence for a role for intracellular TG2 in regulating activation of the small GTPases to promote efficient fibroblast migration. This work identifies TG2 as a facilitator of efficient wound closure through extracellular effects on integrin-mediated signalling and intracellular effects on activation of the small GTPases.

Thesis (M. D. S.)--University of Hong Kong, 2003. / Title proper from title frame. Also available in printed format.

歯科基礎医学会, 飯塚 正 = Tadashi Iizuka, 放射線照射ラットの抜歯創治癒過程に関する形態学的研究 = Morphological studies on the healing process of extraction wound in irradiated rats, 歯科基礎医学会雑誌, 26(3), SEP 1984, pp.745-785 / Hokkaido University (北海道大学) / 博士 / 歯学

When an accident involving the possibility of a plutonium contaminated wound occurs, the contamination is often quantified using sodium iodide (NaI(Tl)) and high purity germanium (HPGe) detection systems. The NaI(Tl) system is used to quantify the amount of contamination, while HPGe is used to gauge the depth of contamination in the wound. Assessment of plutonium contaminated wounds is difficult due to the lowenergy and yield of the uranium L-shell x rays used for the measurement, which can be effected by source distance, shape, and tissue attenuation. These effects on wound counting systems used at Los Alamos National Laboratory (LANL) were characterized experimentally using common source shapes (disk, point, and line) and acrylic plastic as a tissue substitute. Experiments were conducted to characterize detector responses as a function of tissue attenuation, source distance, and source depth in tissue. The computer code MCNP5 was used to model both systems for wound counting and better examine angular displacement of a line source in tissue. The NaI(Tl) detector response was characterized using absolute detector efficiency for all experimental measurements. Measurements showed that the NaI(Tl) system is significantly effected by the source to detector position and depth in tissue. Characterization of the HPGe detection system was done utilizing the peak-to-peak ratio from the two low-energy x rays. HPGe peak-to-peak ratios were not affected by source to detector distance, but showed an increased response to source depth in tissue. MCNP results suggested that small incident angles from the plane of the detector face can cause significant effects on the response of both detectors. In summary, the response of both systems showed dependence on source geometry and depth of contamination in tissue. Correction values and uncertainties were determined based on these dependencies.

Activin is a dimeric protein of inhibin beta subunit, which is abundantly stored in normal bone matrix, presumably produced by osteoblasts in the process of normal bone formation. The expression of activins was examined in the wound healing of diabetic rats. In this study,insulin-dependent diabetes mellitus was induced in a group of mature Sprague-Dawley rats by injecting streptozotocin. Control animals were injected with citrate buffer only. After 3 weeks,all of rats underwent extraction of the right maxillary molars teeth after anesthesia. Rats were killed at varying intervals and the maxilla and calvaria were recovered in continuity. Tissue sections were stained with hematoxylin-eosin as well as immunohistochemical gent. Hematoxylin-eosin analyses showed that at 7 days after tooth extraction in the control and insulin-streptozotocin-treated rats there were, thick collagen fibers which formed a pretrabecular the scaffold dictated the direction of the forming trabeculae. However,the collagen fibers in the diabetic socket were thin and scanty, and only formed a narrow layer in the apical part of the socket. These histologic observations suggest that in uncontrolled, insulin-dependent diabetes, the formation of the collagenous framework in the tooth extraction socket is inhibited, resulting in delayed healing.The immunohistochemical analyses showed that at 7 days after tooth extraction in both control and insulin-streptozotocin-treated rats, osteoblasts were increased in extra-alveolar bone formation.Our findings also suggested that activin was actively involve in bone modeling during osteogenesis. These findings suggest that activin may play important role in the regulation of bone formation and it may be useful in the future for the wound healing in diabetic patients.