Spelling suggestions: "subject:"frost's""
11 |
Células-tronco mesenquimais em modelo de lesão cutânea induzida experimentalmente por nitrogênio líquido em ratos WistarValente, Fernanda Soldatelli January 2018 (has links)
A criocirurgia tem sido utilizada no tratamento de diferentes enfermidades de sistemas e órgãos, tanto na medicina humana quanto na medicina veterinária, sendo sua maior indicação o tratamento de dermatopatias. Contudo, efeitos adversos como a cicatrização lenta, cicatrizes extensas, disfunção estética e funcional, são relatados após a aplicação da substância criogênica. Ainda, existem as lesões que ocorrem naturalmente pela exposição ao frio extremo, afetando principalmente o nariz, dedos das mãos e pés ou orelhas. Na maioria das vezes resultam em gangrena e são bem comuns nos habitantes dos polos, turistas e praticantes de modalidades na neve. O presente trabalho tem como objetivo avaliar a influência das células-tronco mesenquimais de origem adiposa (ADSCs) na cicatrização de feridas cutâneas padronizadas e induzidas pelo nitrogênio líquido em ratos em duas fases da cicatrização cutânea: fase de proliferação e fase de remodelação. Utilizaram-se 83 ratos Wistar, machos, hígidos, com oito semanas de idade, sendo três animais usados como doadores de tecido adiposo para posterior obtenção das ADSCs e, 80 animais divididos aleatoriamente em oito grupos de tratamento (n=10). Através da aplicação do nitrogênio líquido pela técnica do spray aberto, realizou-se a indução de uma ferida, de aproximadamente 15 mm de diâmetro, na região dorsal de cada rato. A ferida recebeu o tratamento de acordo com o grupo ao qual pertencia: a) aplicação das ADSCs, por via subcutânea, no 15º dia (T1), no 30º dia (T2) ou nos dois tempos mencionados (T3) após a indução da lesão; b) aplicação da solução cloreto de sódio 0,9%, por via subcutânea, no 15º dia (S1), no 30º dia (S2) ou nesses dois tempos (S3) após a indução da lesão; c) nenhuma intervenção até o momento da eutanásia dos animais no 45º dia (C1) ou no 60º dia (C2). Macroscopicamente, a cada cinco dias, analisaram-se as medidas das lesões e calculou- se a área e a taxa de contração cicatricial das mesmas. No 45º ou no 60º dia pós- operatório, procedeu-se à coleta das biópsias para avaliação histopatológica e imuno- histoquímica. Com base nos resultados obtidos concluiu-se que: 1) o grupo T1 apresenta as maiores taxas de contração média das feridas no 20º e 25º dia; 2) o grupo T3 obteve a maior taxa de contração média das feridas no 30º dia pós-operatório; 3) o grupo T2 apresenta as maiores taxas de contração média das feridas no 55º e 60º dia; 4) o grupo T1 obteve diferença estatisticamente significativa em relação ao grupo sham (S3) quanto à neovascularização, avaliada pela técnica de imuno-histoquímica com o VEGF; 5) o grupo sham (S1) obteve diferença estatística significativa em relação aos grupos tratados com as ADSCs (T2 e T3) quanto à proliferação epitelial, avaliada pela técnica de imuno-histoquímica com o anticorpo Ki-67; 6) a terapia com as ADSCs proporciona uma relevante evolução clínica das feridas, podendo ser constatada ao final do período de avaliação por cicatrizes mais estreitas e compridas com as medidas da área final inferiores às cicatrizes dos grupos controle (C1 e C2) e sham (S1, S2 e S3). Propõem-se a necessidade de novos estudos com as ADSCs na cicatrização de lesões cutâneas provocadas pela criocirurgia ou por outra modalidade de congelamento, realizando biópsias com análises histopatológicas e imuno-histoquímicas em períodos de tempo menores e maiores aos realizados nesse estudo, a fim de detectar, respectivamente, diferenças no processo de cicatrização imediatamente após a aplicação das ADSCs e, também, acompanhar o remodelamento da cicatriz por um período mais longo. / Cryosurgery has been used to treat different diseases of systems and organs in both human and veterinary medicine. Although treatment of skin disorders is the leading indication, adverse effects such as delayed wound healing, large scars, esthetical deformation and functional impairment have been reported from administration of cryogenic substance. Beside that there are injuries caused naturally by the exposure to extreme cold weather conditions, which affect specially nose, fingers, toes and ears, mostly resulting in gangrene. These frostbites are very common in people who live in the Poles, tourists and snowboarders. This study aims to evaluate the influence of adipose-derived stem cells (ADSCs) on cutaneous wound healing that were standardized and induced by liquid nitrogen in rats according to two phases of cutaneous healing: proliferation phase and remodelling phase. For research purposes, 83 male, healthy and eight-weeks-old Wistar rats were required. Among 83 rats, three were used as adipose tissue donor for later ADSCs obtention and 80 Wistar rats were randomly divided in eight treatment groups (n=10). Through the application of liquid nitrogen by spraying technique, a 15 millimetres in diameter lesion was produced in the dorsal region of each rat. The wound received treatment according to the group it belonged: a) subcutaneously ADSCs application on the 15th day (T1), on the 30th day (T2) or in both periods mentioned (T3) after wound induction; b) subcutaneously application of 0.9% sodium chloride solution on the 15th day (S1), on the 30th day (S2) or in both periods mentioned (S3) after wound induction; c) no intervention until euthanasia on the 45th day (C1) or 60th day (C2) Macroscopically, every five days, the wounds were measured to calculate their area and healing rate. On the 45th and 60th postoperative day, biopsies were performed for histopathological and immunohistochemical evaluations. By the obtained results, the study concludes that:1) T1 group shows the highest wound average contraction rate on the 20th and 25th day; 2) T3 group presents the highest wound average contraction rate on the 30th postoperative day; 3) T2 group has the highest wound average contraction rate on the 55th and 60th day; 4) T1 group got a significant statistical difference in relation to sham group (S3) when it refers to neovascularization, which was evaluated by immunohistochemical technique with VEGF; 5) sham group (S1) obtained a significant statistical difference when compared to ADSCs groups (T2 and T3) with respect to epithelial proliferation, that was evaluated by immunohistochemical technique using antibody Ki-67; 6) the ADSCs therapy provides an important clinical evolution of wounds. This was verified at the end of evaluation period through narrower and longer scars with bottom end area measurements inferior to control group scars (C1 and C2) and sham group scars (S1, S2 and S3). Lastly, this paper proposes the necessity of new studies about the uses of ADSCs for cutaneous wound healing caused by cryosurgery or other sort of freeze. Furthermore it is opportune taking an action on studies that do biopsies with histopathological and immunohistochemical analyses using shorter and longer periods of time that those executed on this paper. Thus it will be possible to find out, respectively, differences on the healing process immediately after applying ADSCs and also follow up the scar remodelling for a longer period.
|
12 |
A TEMPORAL STABLE DISTANCE TO EDGE ANTI-ALIASING TECHNIQUE FOR GCN ARCHITECTUREGöransson, Jonas Alexander January 2015 (has links)
Context. Aliasing artifacts are a present problem in both the game industryand the movie industry. With the GCN (Graphics Core Next) architectureused on both new generation of consoles; Xbox One and Playstation 4, aunified Anti-Aliasing solution can be constructed with high performance,temporal stable edges and satisfying visual fidelity. Objective. This thesis aims to implement several prototypes which willbe utilizing GCN architecture to solve aliasing artifacts such as temporalstability. Method. By doing performance measurements, a survey and an experimenton the constructed prototypes and current state of the art solutionsthis thesis will create both a benchmark between given state of the art solutionsfor the industry and at the same time evaluate the new solutions givenin this thesis. Result. With having potential of being the fastest Anti-Aliasing solutionin the field it does not only bring high performance, but also very temporalstable edges and satisfying visual quality. Conclusion. If not used as a standalone solution, the prototype can be decoupledfrom GCN specific features and be a very suitable complement forMulti Sample Anti-Aliasing which can not handle alpha clipped edges.
|
13 |
Células-tronco mesenquimais em modelo de lesão cutânea induzida experimentalmente por nitrogênio líquido em ratos WistarValente, Fernanda Soldatelli January 2018 (has links)
A criocirurgia tem sido utilizada no tratamento de diferentes enfermidades de sistemas e órgãos, tanto na medicina humana quanto na medicina veterinária, sendo sua maior indicação o tratamento de dermatopatias. Contudo, efeitos adversos como a cicatrização lenta, cicatrizes extensas, disfunção estética e funcional, são relatados após a aplicação da substância criogênica. Ainda, existem as lesões que ocorrem naturalmente pela exposição ao frio extremo, afetando principalmente o nariz, dedos das mãos e pés ou orelhas. Na maioria das vezes resultam em gangrena e são bem comuns nos habitantes dos polos, turistas e praticantes de modalidades na neve. O presente trabalho tem como objetivo avaliar a influência das células-tronco mesenquimais de origem adiposa (ADSCs) na cicatrização de feridas cutâneas padronizadas e induzidas pelo nitrogênio líquido em ratos em duas fases da cicatrização cutânea: fase de proliferação e fase de remodelação. Utilizaram-se 83 ratos Wistar, machos, hígidos, com oito semanas de idade, sendo três animais usados como doadores de tecido adiposo para posterior obtenção das ADSCs e, 80 animais divididos aleatoriamente em oito grupos de tratamento (n=10). Através da aplicação do nitrogênio líquido pela técnica do spray aberto, realizou-se a indução de uma ferida, de aproximadamente 15 mm de diâmetro, na região dorsal de cada rato. A ferida recebeu o tratamento de acordo com o grupo ao qual pertencia: a) aplicação das ADSCs, por via subcutânea, no 15º dia (T1), no 30º dia (T2) ou nos dois tempos mencionados (T3) após a indução da lesão; b) aplicação da solução cloreto de sódio 0,9%, por via subcutânea, no 15º dia (S1), no 30º dia (S2) ou nesses dois tempos (S3) após a indução da lesão; c) nenhuma intervenção até o momento da eutanásia dos animais no 45º dia (C1) ou no 60º dia (C2). Macroscopicamente, a cada cinco dias, analisaram-se as medidas das lesões e calculou- se a área e a taxa de contração cicatricial das mesmas. No 45º ou no 60º dia pós- operatório, procedeu-se à coleta das biópsias para avaliação histopatológica e imuno- histoquímica. Com base nos resultados obtidos concluiu-se que: 1) o grupo T1 apresenta as maiores taxas de contração média das feridas no 20º e 25º dia; 2) o grupo T3 obteve a maior taxa de contração média das feridas no 30º dia pós-operatório; 3) o grupo T2 apresenta as maiores taxas de contração média das feridas no 55º e 60º dia; 4) o grupo T1 obteve diferença estatisticamente significativa em relação ao grupo sham (S3) quanto à neovascularização, avaliada pela técnica de imuno-histoquímica com o VEGF; 5) o grupo sham (S1) obteve diferença estatística significativa em relação aos grupos tratados com as ADSCs (T2 e T3) quanto à proliferação epitelial, avaliada pela técnica de imuno-histoquímica com o anticorpo Ki-67; 6) a terapia com as ADSCs proporciona uma relevante evolução clínica das feridas, podendo ser constatada ao final do período de avaliação por cicatrizes mais estreitas e compridas com as medidas da área final inferiores às cicatrizes dos grupos controle (C1 e C2) e sham (S1, S2 e S3). Propõem-se a necessidade de novos estudos com as ADSCs na cicatrização de lesões cutâneas provocadas pela criocirurgia ou por outra modalidade de congelamento, realizando biópsias com análises histopatológicas e imuno-histoquímicas em períodos de tempo menores e maiores aos realizados nesse estudo, a fim de detectar, respectivamente, diferenças no processo de cicatrização imediatamente após a aplicação das ADSCs e, também, acompanhar o remodelamento da cicatriz por um período mais longo. / Cryosurgery has been used to treat different diseases of systems and organs in both human and veterinary medicine. Although treatment of skin disorders is the leading indication, adverse effects such as delayed wound healing, large scars, esthetical deformation and functional impairment have been reported from administration of cryogenic substance. Beside that there are injuries caused naturally by the exposure to extreme cold weather conditions, which affect specially nose, fingers, toes and ears, mostly resulting in gangrene. These frostbites are very common in people who live in the Poles, tourists and snowboarders. This study aims to evaluate the influence of adipose-derived stem cells (ADSCs) on cutaneous wound healing that were standardized and induced by liquid nitrogen in rats according to two phases of cutaneous healing: proliferation phase and remodelling phase. For research purposes, 83 male, healthy and eight-weeks-old Wistar rats were required. Among 83 rats, three were used as adipose tissue donor for later ADSCs obtention and 80 Wistar rats were randomly divided in eight treatment groups (n=10). Through the application of liquid nitrogen by spraying technique, a 15 millimetres in diameter lesion was produced in the dorsal region of each rat. The wound received treatment according to the group it belonged: a) subcutaneously ADSCs application on the 15th day (T1), on the 30th day (T2) or in both periods mentioned (T3) after wound induction; b) subcutaneously application of 0.9% sodium chloride solution on the 15th day (S1), on the 30th day (S2) or in both periods mentioned (S3) after wound induction; c) no intervention until euthanasia on the 45th day (C1) or 60th day (C2) Macroscopically, every five days, the wounds were measured to calculate their area and healing rate. On the 45th and 60th postoperative day, biopsies were performed for histopathological and immunohistochemical evaluations. By the obtained results, the study concludes that:1) T1 group shows the highest wound average contraction rate on the 20th and 25th day; 2) T3 group presents the highest wound average contraction rate on the 30th postoperative day; 3) T2 group has the highest wound average contraction rate on the 55th and 60th day; 4) T1 group got a significant statistical difference in relation to sham group (S3) when it refers to neovascularization, which was evaluated by immunohistochemical technique with VEGF; 5) sham group (S1) obtained a significant statistical difference when compared to ADSCs groups (T2 and T3) with respect to epithelial proliferation, that was evaluated by immunohistochemical technique using antibody Ki-67; 6) the ADSCs therapy provides an important clinical evolution of wounds. This was verified at the end of evaluation period through narrower and longer scars with bottom end area measurements inferior to control group scars (C1 and C2) and sham group scars (S1, S2 and S3). Lastly, this paper proposes the necessity of new studies about the uses of ADSCs for cutaneous wound healing caused by cryosurgery or other sort of freeze. Furthermore it is opportune taking an action on studies that do biopsies with histopathological and immunohistochemical analyses using shorter and longer periods of time that those executed on this paper. Thus it will be possible to find out, respectively, differences on the healing process immediately after applying ADSCs and also follow up the scar remodelling for a longer period.
|
14 |
Effects of cold and hand-arm vibration on the peripheral neurosensory and vascular system : an occupational perspectiveCarlsson, Daniel January 2017 (has links)
Background In Swedish working life, exposure to cold and exposure to hand-arm vibration (HAV) are two common health hazards. Health effects of HAV in the neurosensory, vascular and musculoskeletal systems are collectively denoted hand-arm vibration syndrome (HAVS), and have been thoroughly studied. Effects of cold exposure in terms of effects on the peripheral neurosensory and vascular system are on the contrary limited, especially in an occupational setting. Effects of cold exposure or cold injury have not previously been assessed with quantitative sensory testing (QST). Commonly reported symptoms after exposure to HAV and after cold injuries, includes cold sensitivity and sensation of cold. Cold sensitivity can also occur without previous exposure to vibration or cold and may have a major impact on quality of life. Other possible risk factors for cold sensitivity need to be assessed. Sensation of cold hands could theoretically imply an early manifestation of damage to the neurosensory or vascular system, and therefore be of importance to enable early detection of vascular and neurosensory HAVS. The purpose of this thesis was to increase the knowledge about health effects from cold and HAV on the peripheral neurosensory and vascular system, with an occupational perspective. The aims were: first, to identify and evaluate health effects and sequelae in the peripheral neurosensory and vascular system due to cold injury and cold exposure; second, to investigate if sensation of cold hands is a predictor for future onset of Raynaud's phenomenon or paresthesia; and third, to identify possible risk factors associated with cold sensitivity. Methods A case series on 15 military conscripts with local cold injuries in the hands or feet, involving QST and symptom descriptions, was conducted to investigate the hypothesis that cold injuries can result in similar neurosensory and vascular impairments as in HAVS. To assess health effects of cold exposure, a cohort study on 54 military conscripts in cold winter military training, with cold exposure assessments, was conducted. Possible health effects were assessed after 14 months of military training, containing considerable cold exposure, by means of QST, Finger systolic blood pressure after local cooling (FSBP) and a questionnaire. To investigate if sensation of cold hands is a predictor for vascular or neurosensory HAVS we investigated a cohort of 178 employees at a manufacturing company where HAV was a common exposure. The cohort was followed during 21 years and both vibration exposure and health outcomes were assessed regularly. Questionnaire items were used to assess sensations of cold hands as well as signs of Raynaud’s phenomenon and paresthesia. To identify risk factors for cold sensitivity a case-control study was conducted involving 997iiiparticipants from the general population in northern Sweden. The study was cross-sectional and explored possible risk factors for cold sensitivity. Results Cold injuries and cold exposure were associated with reduced sensibility in QST and increase severity and prevalence of neurosensory and vascular symptoms. Our results did not show any impairment in peripheral blood flow due to cold exposure, detectable by FSBP. The risk of developing Raynaud's phenomenon was increased for workers previously reporting sensation of cold hands (OR 6.3, 95% CI 2.3-17.0). No increased risk for paresthesia in relation to a sensation of cold hands was observed. The identified risk factors for cold sensitivity were frostbite in the hands, rheumatic disease, nerve injury in upper extremities or neck, migraine and vascular disease. When analysing women and men separately, women’s risk factors were frostbite in the hands, rheumatic disease, migraine and cold exposure. Men’s risk factors were frostbite in the hands, vibration exposure and nerve injury in upper extremities or neck. BMI > 25 was a protective factor for both men and women. Conclusion Cold injury and cold exposure are associated with impairments in the neurosensory system, detectable by QST. Symptoms such as sensation of cold hands and white fingers indicate vascular involvement, even though no vascular impairments due to cold exposure could be detected by objective measurements. A sensation of cold hands is a risk factor for development of Raynaud´s phenomenon, but not for paresthesia. At the individual level, reporting cold hands does not appear to be useful information when considering the possibility of a future development of Raynaud’s phenomenon. Frostbite in the hands is a risk factor for cold sensitivity among both women and men. For women rheumatic disease, migraine and cold exposure are also independent risk factors, and for men, exposure to HAV. Being overweight is a protective factor for both women and men.
|
Page generated in 0.0455 seconds