Towards understanding regional meniscus characteristics important for tissue engineering efforts, meniscus cells were characterized biomechanically and an effective method for isolating these cells for tissue engineering was determined. It was found that the meniscus contains cells that are biomechanically distinct, with outer meniscus cells showing higher stiffness than inner cells. It was also determined that meniscus cells as a whole were more biomechanically similar to ligament cells than to articular chondrocytes, indicating that tissue properties may correlate with cellular mechanics. In addition to showing regionally distinct biomechanical properties, enzymatic isolation of meniscus cells was found to cause varying phenotypic changes in cells from the inner, middle, and outer regions. A comparison of isolation techniques also indicated that sequential digestion of meniscus tissue with pronase and collagenase was able to yield more cells with higher viability than other techniques tested, and those isolated cells created stiffer and more glycosaminoglycan (GAG) rich constructs when used in a tissue engineering modality than cells isolated using only collagenase. The identification of an effective mode of isolating meniscus cells is of great use to tissue engineering efforts, as they often require a large cell numbers. These findings illustrate that known regional variations in meniscus cell phenotype and biochemical composition are also evident in cellular mechanics, and phenotypic responses of these cells to isolation are varied and distinct. To be successful tissue replacements, tissue engineered meniscus constructs must not elicit an immune response and must have sufficient mechanical properties to survive when implanted. To determine if allogeneic or xenogeneic implantation of scaffold-free meniscus constructs could be feasible, the immunogenicity of bovine and leporine meniscus cells and articular chondrocytes were determined in an in vitro model system. It was found that neither bovine nor leporine meniscus cells or articular chondrocytes caused activation of leporine immune cells, suggesting that they may serve as allogeneic or xenogeneic cell sources for meniscus engineering. Additional analysis of the mechanical role of meniscus GAGs indicated that they are mechanically important in all regions of the meniscus, but especially in the inner region where the relatively high GAG content affects both compressive and tensile properties. Therefore, tissue engineering efforts should try to recapitulate GAG content and distribution to enhance the functionality of meniscus replacements. As a major obstacle for meniscus engineering is the identification of an abundant cell source, this thesis also investigated the use of skin cells as an alternative to primary cells for tissue engineering. Previously identified chondroinducible dermis cells were found to have multilineage differentiation capacity, and were subsequently termed dermis isolated adult stem cells (DIAS). DIAS cells were also able to be expanded in monolayer without losing chondroinductive capacity, and were able to create constructs with cartilaginous properties which could be varied with growth factor application. Given the ease of expansion and ability of DIAS cells to form fibrocartilaginous tissue, these cells present an abundant cell source for meniscus tissue engineering.

p-Dichlorobenzene (p-DCB) and naphthalene are compounds classified as Group C carcinogens according to the USEPA. Sources of p-DCB and naphthalene include moth repellents and deodorizers typically used in closets, garment bags, and toilet bowls found in pure form. In this study, laboratory, closet, and garment bag experiments were used to determine emission rates of p-DCB and naphthalene from consumer products (closet air freshener, toilet bowl deodorizer, and moth repellent). Emission rates varied considerably between products that contain p-DCB, primarily due to product packaging, and were generally suppressed when the product was used in a closed closet or garments bag, relative to products placed in well-ventilated chambers. Experimental mass emission rates were used in conjunction with a well-mixed reactor model to predict indoor p-DCB and naphthalene concentrations for a range of reasonable residential scenarios. Results suggest that exposures under worst-case scenarios could lead to excess lifetime cancer risks of greater than 20,000 in a million (2%) for those who use consumer products that are pure p-DCB, a risk that dwarfs any reported environmental cancer risks over large segments of the US population. Since such products are typically used where clothing is kept, significant chemical adsorption onto clothing is possible following sublimation from the solid product. Chamber experiments were used to determine the amount of p-DCB and naphthalene mass that adsorbs onto selected clothing materials made of cotton, polyester, or wool. Cloth specimens were kept inside a chamber through which an air stream containing p-DCB or naphthalene was passed for one month. After this time, p-DCB or naphthalene were chemically extracted from the cloth specimens. Polyester was determined to be the most adsorbent material, while cotton was the least adsorbent for each chemical. Equilibrium partition coefficients of 0.01 m³/g for p-DCB and 0.02 m³/g for naphthalene were determined experimentally for wool. Desorption rates were determined in both laboratory chambers and a closet in a test house. Results suggest prolonged persistence of p-DCB and naphthalene on polyester and wool, e.g., half-lives of 12 to 20 days after a moth repellent is removed from the clothes storage environment. An exposure scenario was also carried out to compare the inhalation and dermal exposure risks associated with contaminated clothing. / text

Cobalt is a commonly known sensitiser in industrial settings and has been classified by the IARC as a possible group (2B) human carcinogen. Workers at a South African base metal refinery are potentially exposed to cobalt in the cobalt packaging area. The respiratory and dermal exposure to cobalt is a possible health risk. Quantifying the exposures levels assists in determining the degree of the risk as well as the management thereof. The objectives of this study were to assess dermal and respiratory exposure of workers at a cobalt packaging area and to assess their skin condition by measuring transepidermal water loss (TEWL) and skin hydration indices. The skin hydration index was measured on the back of the hand, forehead, wrist and palm at the start, during and end of the shift. The TEWL index was measured at the start and end of the shift on the same areas as the hydration index. Ghostwipes was chosen as preferred wipe sampling media to collect dermal and surface samples. Wipe samples were also taken on suspected contaminated workplace surfaces. Respiratory samples were taken by using the Institute of Occupational Medicine (IOM) inhalable aerosol sampler at a flow rate of 2 l/min. Wipes and respiratory samples were analysed for cobalt according to NIOSH method 9102 using inductively coupled plasma–atomic emission spectrometry (ICP–AES). The hydration indices indicated that worker’s skin are slightly dry to normal at the beginning of the shift. Hydration on the wrist increased significantly during the shift. TEWL indices increased significantly on the back of the hand, wrist and forehead during the shift. TEWL indices of the palm showed a low barrier function before the shift and deteriorated further to a very low barrier function at the end of the shift. Significant dermal cobalt loading occurred on the back of the hand, forehead, wrist and palm during the shift. The palm was the most exposed and the forehead least. The barrier function of the skin is most likely to be affected by exposure to cobalt. The skin condition of workers put them at greater risk to develop adverse health effects of cobalt. Workplace surfaces were contaminated with cobalt. Airborne cobalt was visible at different working stations. Cobalt exposure is due to numerous sources in the packaging area, thus contributing to the dermal exposure. Respiratory exposure exceeded the 8 hour occupational exposure limit for most of the workers. The guidance limit for short term exposure was exceeded by half of the workers. It is important to minimise the exposure to cobalt in packaging area. Manifestation of the adverse health effects are usually not visible in the short term, the necessary precautions have to be taken to protect the workers. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Cobalt is a commonly known sensitiser in industrial settings and has been classified by the IARC as a possible group (2B) human carcinogen. Workers at a South African base metal refinery are potentially exposed to cobalt in the cobalt packaging area. The respiratory and dermal exposure to cobalt is a possible health risk. Quantifying the exposures levels assists in determining the degree of the risk as well as the management thereof. The objectives of this study were to assess dermal and respiratory exposure of workers at a cobalt packaging area and to assess their skin condition by measuring transepidermal water loss (TEWL) and skin hydration indices. The skin hydration index was measured on the back of the hand, forehead, wrist and palm at the start, during and end of the shift. The TEWL index was measured at the start and end of the shift on the same areas as the hydration index. Ghostwipes was chosen as preferred wipe sampling media to collect dermal and surface samples. Wipe samples were also taken on suspected contaminated workplace surfaces. Respiratory samples were taken by using the Institute of Occupational Medicine (IOM) inhalable aerosol sampler at a flow rate of 2 l/min. Wipes and respiratory samples were analysed for cobalt according to NIOSH method 9102 using inductively coupled plasma–atomic emission spectrometry (ICP–AES). The hydration indices indicated that worker’s skin are slightly dry to normal at the beginning of the shift. Hydration on the wrist increased significantly during the shift. TEWL indices increased significantly on the back of the hand, wrist and forehead during the shift. TEWL indices of the palm showed a low barrier function before the shift and deteriorated further to a very low barrier function at the end of the shift. Significant dermal cobalt loading occurred on the back of the hand, forehead, wrist and palm during the shift. The palm was the most exposed and the forehead least. The barrier function of the skin is most likely to be affected by exposure to cobalt. The skin condition of workers put them at greater risk to develop adverse health effects of cobalt. Workplace surfaces were contaminated with cobalt. Airborne cobalt was visible at different working stations. Cobalt exposure is due to numerous sources in the packaging area, thus contributing to the dermal exposure. Respiratory exposure exceeded the 8 hour occupational exposure limit for most of the workers. The guidance limit for short term exposure was exceeded by half of the workers. It is important to minimise the exposure to cobalt in packaging area. Manifestation of the adverse health effects are usually not visible in the short term, the necessary precautions have to be taken to protect the workers. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Objectives: The objectives of this study were to establish the extent of dermal and respiratory exposure at selected locations at a South African platinum mine. The study included exposure to lead oxide fumes in an assay laboratory, nickel sulfate powder at a nickel sulfate crystallizer circuit and packing site and metallic copper dust whilst executing copper stripping. Methods: In an availability study, the dermal metal exposures were measured before, during and at the end of shifts. Dermal exposure samples were taken with GhostwipesTM from the dominant hand, wrist and forehead. Wipes were analyzed using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Wipe samples were taken from surfaces in the workplace and analyzed according to NIOSH 9102, using ICP-AES. Personal and static inhalable dust samples were taken and the dust samples were analyzed according to NIOSH 7300, using ICP-AES. A validated questionnaire was used to evaluate self reported dermatological complaints of the workers at the fire assay laboratory and base metal recovery plant. Results: 100% of the nickel respiratory exposures and 36.8% of the lead respiratory exposures were above the occupational exposure limits (OEL). Copper respiratory exposure was present but less significant with a geometric mean of 0.071 mg m-3. All of the dermal lead measurements and the majority of the nickel and copper dermal measurements were below the limit of detection. Nickel surface contamination was the most significant and ranged between 8.430 μg cm-2 and 387.488 μg cm-2. Only 30% of the copper surface sample results were below the detection limit with a maximum surface sample of 14.41 μg cm-2. Lead surface contamination was low with 90% of the samples below the limit of detection. All of the workers at the nickel crystallizer circuit and packing site had a Dalgard score above 1.3 and therefore are at a higher risk of developing a skin disease. None of the workers at the copper stripping site had a significant Dalgard score and only one worker at the fire assay laboratory had a score above 1.3 and therefore is at a higher risk of developing a skin disease. Conclusions: Recommendations were made to lower the exposure to inhalable lead and nickel. The low lead dermal measurements may be due to adequate personal protective equipment usage and hygiene practices. Although the ethnicity of the workers may be the reason for the low incidence of dermatological complaints, the Dalgard score indicated that five workers are at risk of developing skin diseases. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011

Wound healing is governed by a complex cascade of related processes, involving cells, extracellular matrix and cytokines. In adults this always results in a scar whilst embryonic wound healing is scarless and extensive research worldwide is aimed at reducing scarring in adults. A mathematical framework for problems in dermal wound healing is developed that incorporates models of the individual processes involved. Cells are modelled as discrete individuals. Cytokines and other biologically active factors are modelled as continua. A novel tensorial approach is taken to modelling the extracellular matrix. The numeric and computational challenges associated with combining models for the individual processes are identified and investigated. These include the development of data structures and numeric methods for the continuous and discrete species. Effective visualisation methods for the large amounts of data generated by the model are also discussed. The possibilities offered by high performance computing in mathematical biology are highlighted in this work. The final part of this thesis gives an example of a combined model of the inflammatory and proliferative phases of dermal wound healing using the new computational framework. Both quantitative and qualitative methods are used to analyse the information-rich data sets generated by the model, offering insight into the dynamic systems that can be modelled using the new approach.

Orientador: Silvana Artioli Schellini / Resumo: OBJETIVO: Avaliar a eficiência da injeção de ácido hialurônico (AH) ou de soro fisiológico (SF), aplicados no subcutâneo da pálpebra inferior de portadores de ectrópio cicatricial, visando à correção não cirúrgica do mal posicionamento palpebral. MÉTODOS: este foi um estudo prospectivo, intervencionista, envolvendo 23 pálpebras de 15 portadores de ectrópio cicatricial, divididos aleatoriamente em dois grupos: G1 (13 pálpebras) no qual foram feitas quatro aplicações de 4ml de SF (Cloreto de Sódio 0,9%, Equiplex, Goiás, Brasil), associado a 1ml de cloridrato de lidocaína a 2,0% sem vasoconstritor (Xylestesin®, Cristália, São Paulo, Brasil), em intervalos de uma semana entre as aplicações; e G2 (10 pálpebras) que receberam aplicação de 1 ml de AH (Restylane® Lidocaine, Q med, Uppsala, Suécia) em aplicação única. Foram avaliadas as variáveis demográficas dos participantes, as queixas, o grau do ectrópio, o grau de flacidez palpebral, a localização do ectrópio, além de avaliações quantitativas realizadas utilizando-se a fotodocumentação sistematizada dos olhos dos pacientes, 30 dias após a primeira aplicação no G1 e 7 e 30 dias após as aplicações do G2. As imagens obtidas foram transferidas para um computador e avaliadas utilizando-se o programa Image J, avaliando-se a distância da pálpebra inferior até o reflexo corneano (DMR2), distância limbo-margem (LM), ângulo da comissura interna (AI) e externa (AE), área total (AT), lateral (AL) e medial (AM). As áreas a serem avaliadas for... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: PURPOSE: Evaluate the efficiency of injection of hyaluronic acid (HA) or saline solution (SF) applied to the lower eyelid subcutaneous, aiming at the non-surgical correction of cicatricial ectropion. METHODS: This was a prospective study involving 23 eyelids of 15 patients with cicatricial ectropion, randomly divided into two groups: G1 (13 eyelids) with four applications of 4ml of SF (Sodium Chloride 0.9%, Equiplex, Goiás , Brazil), associated to 1ml of lidocaine hydrochloride 2% without vasoconstrictor (Xylestesin®, Cristália, São Paulo, Brazil), with a one-week interval between applications; and G2 (10 eyelids) which received single application of 1 ml of AH (Restylane® Lidocaine, Q med, Uppsala, Sweden). Demographic variables, complaints, ectropion degree, eyelid flaccidity degree, ectropion location, and quantitative assessments using the systematized photodocumentation of patients eyelids 30 days after the first application in G1 and 7 and 30 days after applications in G2 were studied. The images were transferred to a computer and evaluated using the Image J program and the distance between the lower eyelid margin to corneal reflex (DMR2), limbus margin distance (LM), internal angle (IA) and external angle (EA), total (TA), lateral (LA) and medial areas (MA) were analyzed. The area measurements were delimited by a line between the two commissures and along the lid margin of the lower eyelid. The evaluations were done without traction and with traction downward of the lo... (Complete abstract click electronic access below) / Mestre

Orientador: Vera Lucia Borges Isaac / Coorientador: Marcos Antonio Corrêa / Banca: Hérida Regina Nunes Salgado / Banca: André Rolim Baby / Resumo: O aumento da expectativa de vida tem provocado grande demanda por produtos que auxiliem na prevenção do envelhecimento da pele. O ácido hialurônico (AH) está sendo muito utilizado em formulações antienvelhecimento por se acreditar que ele possa atenuar os efeitos que o tempo produz na pele. Porém, para o desenvolvimento de um cosmético, é necessário avaliar o risco potencial dos ingredientes que compõem a formulação, que devem estar em concentração que apresente margem de segurança adequada, sendo importante a realização de teste de absorção, estudo do potencial de risco irritativo e testes de mutagenicidade. O objetivo deste estudo foi desenvolver um gel de ácido hialurônico com alta massa molecular e incorporar ácido hialurônico de massas moleculares menores, realizar o controle microbiológico dos géis, avaliar a toxicidade dérmica aguda e a citotoxicidade, determinar o comportamento reológico das formulações, analisar seu perfil de liberação, permeação e retenção cutânea in vitro. Foi preparado como gel base, a mistura de água e AH de alta massa molecular e, posteriormente, neste gel formado foram incorporados os AHs de menores massas moleculares. O controle de qualidade microbiológico foi realizado de acordo com a Farmacopeia Brasileira (2010), a avaliação da toxicidade dérmica aguda foi realizada utilizando-se 25 ratos wistar, que foram divididos em 5 grupos com 5 animais em que cada grupo recebeu a aplicação de um dos géis para posterior analise dos resultados. Para a avaliação da citotoxicidade utilizou-se o método colorimétrico 3-(4,5-dimetiltiazol-2-il)2,5-difenil brometo de tetrazoilium (MTT) descrito por MOSMANN, utilizando-se linhagens celulares de HepG2 (Human Epidermoide Cancer Cells) e HaCaT. As amostras tiveram seu comportamento reológico avaliado em reômetro HAAKE. O estudo de liberação, permeação e retenção cutânea... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Increased life expectancy has caused a great demand for products that help in the prevention of skin aging. Hyaluronic acid is being used in anti-aging formulations because it is expected that it can decrease the effects of time in the skin. However, for the development of a cosmetic it is necessary to evaluate the potential risk of the ingredients in the formulation that should be with adequate concentration to provide a margin of safety, being important to carry out absorption test, studies of the potential risk of irritating the skin and mutagenicity tests. The aim of this study was to develop a gel of hyaluronic acid with high molecular weight and incorporate hyaluronic acid with small molecular weights in it, analyze the microbiological control of the gels, evaluate the acute dermal toxicity and cytotoxicity, determine rheological characteristics, analyze the release profile, skin permeation and retention in vitro. It was prepared like gel base, the mixture of water and AH of high molecular weight, and after was incorporate AH of smaller molecular weight. The quality control microbiological was accomplished in agreement with Brazilian Pharmacopoeia (2010), the evaluate the acute dermal toxicity was made with 25 rat wistar, that were divided in 5 groups with 5 animals in each group received the application from one of the gels for subsequent analyzes of the results. For the evaluation of the cytotoxicity was used the method colorimeter 3-(4,5-dimetiltiazol-2-il)2,5-difenil tetrazoilium bromide (MTT) described by MOSMANN (1983), being used cellular lineages of HepG2 (Human Epidermoide Câncer Cells) and HaCaT. The samples had its behavior rheological characteristics. The analyze the release profile, skin permeation and retention were accomplished using cells of Franz modified. The microbiological was in agreement... (Complete abstract click electronic access below) / Mestre

The thesis presents a rational path for the optimization of the selection of optical treatment parameters in photobiomodulation of human skin fibroblasts. The project begins with an extensive analysis of 90 bibliographic reports in photobiomodulation published between 1985 and 2015, and revealed major inconsistencies in optical parameters selected for clinical applications. Seeking greater clarity for optimal parameter choice, a systematic approach to disentangle the multiple factors underpinning the response of human dermal fibroblasts in vitro to visible and near-infra red (NIR) light was employed. Light-based devices were constructed to specifically and systematically screen the optical parameter window (i.e. wavelength, irradiance and dose) observed in literature. Additionally, critical culture and treatment conditions that have dramatic impact on the outcome of specific light treatment of these human skin dermal cells were identified. In particular, environmental oxygen concentration, cell confluency and serum concentration were all found to have a great effect on the response of dermal fibroblasts to light. In parallel, the induction of reactive oxygen species (ROS) by short visible wavelengths on two dermal fibroblast sub-populations or lineage, reticular and papillary, was monitored by live-cell imaging. The ROS species were found to be created in or close to mitochondria. Lastly, gene expression studies revealed a strong impact of short visible wavelengths, as compared to long and NIR wavelengths on both subpopulations of human dermal fibroblasts. In particular, blue light (450 nm) specifically down-regulated proliferation, metabolism and protein synthesis molecular pathways. At the protein level, 450-nm light inhibited the production of procollagen I in human reticular and papillary fibroblasts in a dose-dependent manner. Gene expression results were in agreement i.e., the same light parameter down-regulated collagen fiber genes, integrins and up-regulated collagenase MMP1. This thesis concludes with a chapter presenting a characterization of the accuracy of a potential translation tool for the prediction of optical photon density inside human skin.

Made available in DSpace on 2014-06-11T19:33:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-02-14Bitstream added on 2014-06-13T21:06:14Z : No. of bitstreams: 1 oliveira_ca_dr_arafo.pdf: 373237 bytes, checksum: 63181781c60cf9cb130f5b53b34e9b3d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O propósito deste estudo foi avaliar histológica e histometricamente o resultado da utilização das matrizes de colágeno de Pericárdio Bovino (MPB) e Dérmica Acelular (MAD) no tratamento de deiscências ósseas criadas cirurgicamente em cães. Foram criados defeitos periodontais do tipo deiscência óssea na superfície vestibular dos 2os, 3os e 4os pré-molares inferiores de seis cães. Estes dentes foram divididos em 3 grupos: grupo I: MAD; grupo II: controle e grupo III: MPB, ambos com reposição coronária do retalho. Após 70 dias os animais foram sacrificados, os dentes retirados em bloco e processados histologicamente. Realizou-se análise histológica descritiva e histométrica, medindo-se a extensão do tecido epitelial, neoformação óssea e cementária e nível gengival para os grupos I, II e III. Os resultados demonstraram valores estatisticamente iguais para as medianas (em mm) dos valores de epitélio: 1,49, 1,91 e 1,82; cemento: 3,18, 3,09 e 3,31 respectivamente para os grupos I, II e III. Foi encontrada diferença estatisticamente significante em relação à neoformação óssea, com medianas (em mm) de 1,23, 1,82 e 1,62, respectivamente para os grupos I, II e III. Foi observado escasso infiltrado inflamatório. Com isso, pudemos concluir que as matrizes de MPB e MAD são materiais que permitem a reparação dos tecidos periodontais. / The goal of this investigation was to compare, histologically and histometrically, the healing process of dehiscence-type defects treated by acellular dermal matrix (AD) and bovine pericardium matrix (PB). Six mongrel dogs were used. Buccal osseous deiscences were surgically created on mesial roots of the mandibular second, third and fourth premolars. The defects were randomly assigned to one of the treatments: AD, control and PB. After 70 days of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival level, epithelial length, new cementum and new bone. No statistically significant differences were found between PB, AD and control groups for epithelial length and new cementum parameters (p<0,05). Statistically significant differences were found between PB, AD and control groups for new bone (minor for AD). The presence of a slight inflammation was observed. Withim the limits of this study, it can be concluded that PB and AD showed good biocompatibility, but did not bring a complete periodontal tissue regeneration.