Hypothesis: Trimethoprim promotes wound healing, decreases lesion counts and improves quality of life of recessive dystrophic epidermolysis bullosa (RDEB) patients. Objectives: Assess feasibility of conducting a large randomized clinical trial. Determine efficacy of trimethoprim in healing of chronic wounds, decreasing lesion counts and improving quality of life of RDEB patients. Methods: Prospective, randomized, double-blinded, placebo-controlled, cross-over pilot study. Results: Ten patients enrolled in the trial, 7 completed both study periods. Despite showing that all patients improved on trimethoprim and that there was a 41% difference in affected area percent change favoring trimethoprim, the cross-over analysis did not show a significant difference between the drug and placebo (p=0.08). Secondary outcome measures did not achieve statistical significance. Limitations: Small sample size, large variation in wound size and unaccounted confounders. Conclusions: Although patients experienced improvement while on trimethoprim, no statistical significant change was showed when compared to placebo.

Potential targeting of impaired wounds resulting from hyperglycemia using mesenchymal stem cells is a promising approach. We hypothesized that when administered to dermal wounds in hyperglycemic subjects, neonatal mesenchymal stem cells (MSCs) would be more effective than adult mesenchymal cells in accelerating healing. We examined the in vitro impact of various glucose conditions on proliferation and senescence of human umbilical cord perivascular cells (HUCPVCs) and adult bone marrow MSCs (hBM-MSCs). We also investigated the healing potential of both cells in dermal wounds of streptozotocin-induced NOD-scid-gamma (NSG) mice utilizing planimetry and histomorphometry. HUCPVCs showed higher proliferation under normal and hyperglycemic conditions and lower senescence under all conditions compared to hBM-MSCs. Wound closure was better in treated wounds compared to untreated wounds. Disease tolerance varied among mice which affected healing. HUCPVCs still holds a potential over adult MSCs for impaired wounds; yet more studies are needed to recognize their bona fide capacity.

Although nanocrystalline silver is used commercially to treat burns and wounds, the mechanisms of action (MOA) for its activity are not clear. The purposes of this work were to determine if nanocrystalline silver has anti-inflammatory activity, determine physicochemical properties critical for its MOA, and develop nanocrystalline silver-derived solutions for use in the treatment of lung diseases, including ARDS and pneumonia. In a porcine contact dermatitis model, nanocrystalline silver had anti-inflammatory activity independent of antimicrobial activity, with increased apoptosis induction in inflammatory cells, but not keratinocytes; decreased expression of TNF-, TGF-, IL-8, and MMPs; and increased expression of IL-4, EGF, KGF, and KGF-2. Treatment with AgNO3 (Ag+) increased inflammation, and caused apoptosis induction in keratinocytes. Thus, nanocrystalline silver releases additional species, perhaps Ag^(0)-containing clusters, resulting in anti-inflammatory activity. SIMS analysis showed significant deposition of Ag-clusters after nanocrystalline silver, but not AgNO3, treatment. Nanocrystalline silver had a systemic effect, despite SIMS analysis showing minimal skin penetration by silver, suggesting that nanocrystalline silver interacts with cells near tissue surfaces that release signals altering the inflammatory cascade. Relative to various Ag+-releasing dressings, nanocrystalline silver had significantly enhanced antimicrobial activity, Ag+-resistant bacteria kill, and was not prone to development of resistant bacteria, indicating that nanocrystalline silver releases antimicrobial species additional to Ag+, and has multiple bactericidal MOA. Single silver nanocrystals are inactive, and heat treatment of nanocrystalline silver resulting in crystallites over ~30 nm caused loss of antimicrobial activity, soluble silver, silver oxide, and oxygen. This indicates a poly-nanocrystalline silver structure is necessary for optimal antimicrobial activity, as is having silver oxide to pin the nanostructure, preventing its growth. While oxygen is necessary during sputtering to produce silver oxide, too much oxygen reduces antimicrobial activity, as silver oxide is predominantly deposited. Sufficient total silver, modifiable with current and time, is also important for activity. Nanocrystalline silver-derived solution properties vary significantly with dissolution conditions. Solutions generated at pH 4-6 have stronger antimicrobial activity, and solutions generated at pH 9 have stronger anti-inflammatory activity. Overall, nanocrystalline silver-derived solutions have biological properties similar to nanocrystalline silver, indicating that they may be useful in a variety of medical applications.

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.

This project sought to develop a system that facilitated the visual inspection of venous leg ulcers by establishing a selection of reliable parameters. The project had three principal aims: to develop a reliable method for capturing the colours exhibited by a venous leg ulcer; to establish a colour range that experienced clinicians believed represented wet necrotic tissue and erythema; and to develop software that highlighted the two manifestations in digital photographs. The project method was divided into three phases. The first phase examined images taken from twenty-two patients over forty-seven episodes of care. During each episode three sequential images were captured using a frame to control for orientation, magnification and lighting resulting in a bank of 141 images. The reliability of the system to accurately capture colour was then determined by examining the amount of colour variation recorded across the set of three images taken at each episode. The second phase asked eight experienced clinicians to examine a set of twenty photographs taken from the bank established in phase one. On each photograph the clinicians were asked to identify areas of wet necrotic tissue or erythema and outline the areas with a colour pen supplied for each manifestation. A colour range was then constructed to represent each manifestation by measuring the range, mean and standard deviation of pixels that were located within the outlined areas. The third phase developed a computerised system that used the colour range established in phase two to highlight areas of a digital image that represented either erythema or wet necrotic tissue. The validity of the highlighted areas was then tested by asking experienced clinicians to identify their level of agreement with the areas selected by the computer system. Analysis of the results from phase one indicated that the system used to record images at each episode of care provided a reliable method for maintaining consistent orientation, magnification and replication of colour. Results from phase two yielded a two distinct colour representation of erythema and wet necrotic tissue. Erythema ranged from 3600 to 3780 of hue with a mean of 369.210, and wet necrotic tissue ranged from 3670 to 3900 of hue with a mean of 387.730. Results from phase three indicated that whilst clearly delineated areas of erythema and wet necrotic tissue were visible, the validity of the representations was varied. 50 per cent of experienced clinicians agreed with the areas selected as erythema and 60 per cent agreed with the areas selected by the computer system as wet necrotic tissue. The system developed during this study for recording images of venous leg ulcers provides a reliable method for further research into the visual progression of this disease. However, the colour range identified as being representative of erythema or wet necrotic tissue and the computer system developed to highlight such areas in a digital image, requires further investigation before it is applicable to the clinical setting. The findings do however provide further insights into the varied nature of expert opinion when judging the colour of venous leg ulceration.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Technology, Sydney, 2004. / Bibliographic references: leaves 174-199.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.

Thesis (Ph.D.)--Duquesne University, 2008. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 231-271) and index.