Estudos sobre cronificação têm se mostrado cada vez mais importantes, visto que, tanto na medicina humana, quanto na medicina veterinária, tem sido comum a ocorrência de lesões crônicas, que muitas vezes apresentam dificuldade de cicatrização com terapia convencional. Por este motivo, o presente trabalho tem por objetivo estabelecer modelo de ferida crônica em ratos Wistar, com o uso de agentes químicos, comumente utilizados na rotina clínica como antissépticos, em doses consideradas tóxicas ao leito da ferida. Para isso, foram utilizados 48 ratos Wistar, machos, divididos em quatro grupos de 12 animais cada. (Controle, Polivinilpirrolidona - PVPI 1%, Clorexidina 1% e H2O2 35%). Os animais foram submetidos a anestesia inalatória e sofreram lesão circular de 1cm de diâmetro, confeccionada com o uso de trépano corneal. Foram realizadas duas feridas simétricas paralelas e em seguida à confecção iniciou-se a aplicação tópica dos agentes químicos, com auxílio de pipeta de 50μl, sendo instilados duas vezes ao dia, durante 15 ou 30 dias. As avaliações macroscópicas das feridas induzidas cirurgicamente eram realizadas a cada dois dias, através de medição com paquímetro, além de observação quanto a presenças de sangramentos e outras secreções. Foram avaliadas também através de histologia e imuno-histoquímica. Como resultados o grupo PVPI teve maior taxa de contração, cicatrizando em menor tempo que o grupo controle, embora essa diferença de tempo não tenha sido significativa estatisticamente; apesar das feridas se apresentarem cicatrizadas macroscopicamente, à avaliação histológica foi possível perceber que haviam alterações, dignas de processo cicatricial em curso; o grupo H2O2 proporcionou resultados positivos perante aquilo que foi proposto. Sugere-se que novos estudos sejam realizados, com o H2O2, nos quais os períodos de uso do agente sejam prolongados, superiores aos usados no presente estudo, utilizando ainda material de silicone, fixado nas bordas da ferida, com o intuito de evitar cicatrização por contração. Sugere-se também o uso de doses elevadas de analgésicos durante todo o tempo de experimento. / Research on chronic lesions have been of increased interest in both human and veterinary medicine, as different conditions can delay and lead to difficulties on wound healing, even after conventional therapy has been instituted. Although there are several reports on experimental models for the study of acute wound healing, the establishment of chronic lesions using chemical agents, for scientific purposes, is scarce. This study pursued the development of a chronic skin wound model with chemical substances routinely used as antiseptics, in concentrations considered detrimental to injured tissue. For that, forty-eight Wistar rats were divided in four groups of 12 animals each, for of one of the topical treatments: povidone-iodine solution, 1% chlorhexidine, 35% hydrogen peroxide (H2O2), and control with 0.9% saline solution (NaCl). Under general anesthesia, two circular full skin defects, with 1cm diameter, were produced (with a corneal trephine) in the dorsal cervical region of all the animals. Immediately after the incisions, 50μl of one of the treatments were administrated twice daily, for either 15 or 30 days. Macroscopic evaluations were performed every other day, recording wound size (with a pachymeter) and occurrence of bleeding or exudates. Microscopically, at day 15 or 30, histologic and immunohistochemical studies were carried out with the complete removal of the wound or cicatricial region. Macroscopically, the povidone-iodine group showed faster wound contraction and healing rate than the control, yet, this difference was not statistically significant. Although, under clinical observation, the incised regions presented scar tissue, the histopathological evaluation of the respective specimens showed uncompleted healing process features. The hydrogen peroxide demonstrated promising results to the proposed intent. However, a bigger sample is needed to ascertain the found evidences. Furthermore, studies with longer or more frequent periods of substance exposure, along with devices to circumvent wound contraction and higher doses of analgesics, are recommended.

Estudos sobre cronificação têm se mostrado cada vez mais importantes, visto que, tanto na medicina humana, quanto na medicina veterinária, tem sido comum a ocorrência de lesões crônicas, que muitas vezes apresentam dificuldade de cicatrização com terapia convencional. Por este motivo, o presente trabalho tem por objetivo estabelecer modelo de ferida crônica em ratos Wistar, com o uso de agentes químicos, comumente utilizados na rotina clínica como antissépticos, em doses consideradas tóxicas ao leito da ferida. Para isso, foram utilizados 48 ratos Wistar, machos, divididos em quatro grupos de 12 animais cada. (Controle, Polivinilpirrolidona - PVPI 1%, Clorexidina 1% e H2O2 35%). Os animais foram submetidos a anestesia inalatória e sofreram lesão circular de 1cm de diâmetro, confeccionada com o uso de trépano corneal. Foram realizadas duas feridas simétricas paralelas e em seguida à confecção iniciou-se a aplicação tópica dos agentes químicos, com auxílio de pipeta de 50μl, sendo instilados duas vezes ao dia, durante 15 ou 30 dias. As avaliações macroscópicas das feridas induzidas cirurgicamente eram realizadas a cada dois dias, através de medição com paquímetro, além de observação quanto a presenças de sangramentos e outras secreções. Foram avaliadas também através de histologia e imuno-histoquímica. Como resultados o grupo PVPI teve maior taxa de contração, cicatrizando em menor tempo que o grupo controle, embora essa diferença de tempo não tenha sido significativa estatisticamente; apesar das feridas se apresentarem cicatrizadas macroscopicamente, à avaliação histológica foi possível perceber que haviam alterações, dignas de processo cicatricial em curso; o grupo H2O2 proporcionou resultados positivos perante aquilo que foi proposto. Sugere-se que novos estudos sejam realizados, com o H2O2, nos quais os períodos de uso do agente sejam prolongados, superiores aos usados no presente estudo, utilizando ainda material de silicone, fixado nas bordas da ferida, com o intuito de evitar cicatrização por contração. Sugere-se também o uso de doses elevadas de analgésicos durante todo o tempo de experimento. / Research on chronic lesions have been of increased interest in both human and veterinary medicine, as different conditions can delay and lead to difficulties on wound healing, even after conventional therapy has been instituted. Although there are several reports on experimental models for the study of acute wound healing, the establishment of chronic lesions using chemical agents, for scientific purposes, is scarce. This study pursued the development of a chronic skin wound model with chemical substances routinely used as antiseptics, in concentrations considered detrimental to injured tissue. For that, forty-eight Wistar rats were divided in four groups of 12 animals each, for of one of the topical treatments: povidone-iodine solution, 1% chlorhexidine, 35% hydrogen peroxide (H2O2), and control with 0.9% saline solution (NaCl). Under general anesthesia, two circular full skin defects, with 1cm diameter, were produced (with a corneal trephine) in the dorsal cervical region of all the animals. Immediately after the incisions, 50μl of one of the treatments were administrated twice daily, for either 15 or 30 days. Macroscopic evaluations were performed every other day, recording wound size (with a pachymeter) and occurrence of bleeding or exudates. Microscopically, at day 15 or 30, histologic and immunohistochemical studies were carried out with the complete removal of the wound or cicatricial region. Macroscopically, the povidone-iodine group showed faster wound contraction and healing rate than the control, yet, this difference was not statistically significant. Although, under clinical observation, the incised regions presented scar tissue, the histopathological evaluation of the respective specimens showed uncompleted healing process features. The hydrogen peroxide demonstrated promising results to the proposed intent. However, a bigger sample is needed to ascertain the found evidences. Furthermore, studies with longer or more frequent periods of substance exposure, along with devices to circumvent wound contraction and higher doses of analgesics, are recommended.

The professional public have registered and increased incidence of injuries to children caused by chemical substances during the last years. The issue has recently been neither given appropriate publicity in media nor solved sufficiently, however, with respect to the high frequency and seriousness of injuries, it deserves to be given more significant attention. The research study focused on detailed mapping of the causes and circumstances of the occurrence of the respiratory and gastrointestinal tract injuries in children caused by chemical substances. The research sample comprised of children less than 18 years old who suffered injuries caused by a chemical substance in the monitored period, while being hospitalized in connection with such an injury at the Nemocnice České Budějovice, a. s., Nemocnice Most, o. z., and Fakultní nemocnice Motol, Prague, hospitals. The research study included 90 children (out of which 44 girls and 46 boys). The youngest hospitalized child was five months old, the oldest was seventeen. The required data were collected in a prospective manner (May 1, 2008 - October 31, 2008) and in a retrospective manner (January 1, 2006 {--} April 30, 2008). I obtained the research result though the secondary data analysis (medical documentation) and the analysis of products (those that where staded in the medical documentation to have been packed in an original package). The results of the secondary analysis of the medical documentation refer to the fact that 94 per cent of all the injuries caused by chemical substances were induced by children in their domestic environment. Damage to the organism was caused by agents commonly used in Czech households (waste pipe cleaners, dishwasher tablets, cooker cleaners, etc). It is understandable that packals of these products attract children's attention because producers have selected rich colours (yellow, blue, violet, pink) only for their products as a part of their fight-for-customers strategy. Many products have not been fitted with safety cap closures and in combination with unsuitable storing there was nothing left to prevent an injury. The appearance of new detergents, such as for example dishwasher tablets, on the market is accompanied with the risk of occurrence of new injury types that need to be drawn attention to. In my opinion, sufficient public healt educational campaigns should lead to the decreasing of the number of injuries. Information campaign should be organised in a manner addressing the highest possible number of parents and persons taking care of children. I consider efficient to place information leaflets on the websites of organisations and institutions working with children population, to use TV spots and to distribute information leaflets of brochures to paediatric surgeries and nursery schools. The leaflets should contain information not only about proper household storing of such products, but also several pieces of advice in the case when an injury has already been suffered.

Estudos sobre cronificação têm se mostrado cada vez mais importantes, visto que, tanto na medicina humana, quanto na medicina veterinária, tem sido comum a ocorrência de lesões crônicas, que muitas vezes apresentam dificuldade de cicatrização com terapia convencional. Por este motivo, o presente trabalho tem por objetivo estabelecer modelo de ferida crônica em ratos Wistar, com o uso de agentes químicos, comumente utilizados na rotina clínica como antissépticos, em doses consideradas tóxicas ao leito da ferida. Para isso, foram utilizados 48 ratos Wistar, machos, divididos em quatro grupos de 12 animais cada. (Controle, Polivinilpirrolidona - PVPI 1%, Clorexidina 1% e H2O2 35%). Os animais foram submetidos a anestesia inalatória e sofreram lesão circular de 1cm de diâmetro, confeccionada com o uso de trépano corneal. Foram realizadas duas feridas simétricas paralelas e em seguida à confecção iniciou-se a aplicação tópica dos agentes químicos, com auxílio de pipeta de 50μl, sendo instilados duas vezes ao dia, durante 15 ou 30 dias. As avaliações macroscópicas das feridas induzidas cirurgicamente eram realizadas a cada dois dias, através de medição com paquímetro, além de observação quanto a presenças de sangramentos e outras secreções. Foram avaliadas também através de histologia e imuno-histoquímica. Como resultados o grupo PVPI teve maior taxa de contração, cicatrizando em menor tempo que o grupo controle, embora essa diferença de tempo não tenha sido significativa estatisticamente; apesar das feridas se apresentarem cicatrizadas macroscopicamente, à avaliação histológica foi possível perceber que haviam alterações, dignas de processo cicatricial em curso; o grupo H2O2 proporcionou resultados positivos perante aquilo que foi proposto. Sugere-se que novos estudos sejam realizados, com o H2O2, nos quais os períodos de uso do agente sejam prolongados, superiores aos usados no presente estudo, utilizando ainda material de silicone, fixado nas bordas da ferida, com o intuito de evitar cicatrização por contração. Sugere-se também o uso de doses elevadas de analgésicos durante todo o tempo de experimento. / Research on chronic lesions have been of increased interest in both human and veterinary medicine, as different conditions can delay and lead to difficulties on wound healing, even after conventional therapy has been instituted. Although there are several reports on experimental models for the study of acute wound healing, the establishment of chronic lesions using chemical agents, for scientific purposes, is scarce. This study pursued the development of a chronic skin wound model with chemical substances routinely used as antiseptics, in concentrations considered detrimental to injured tissue. For that, forty-eight Wistar rats were divided in four groups of 12 animals each, for of one of the topical treatments: povidone-iodine solution, 1% chlorhexidine, 35% hydrogen peroxide (H2O2), and control with 0.9% saline solution (NaCl). Under general anesthesia, two circular full skin defects, with 1cm diameter, were produced (with a corneal trephine) in the dorsal cervical region of all the animals. Immediately after the incisions, 50μl of one of the treatments were administrated twice daily, for either 15 or 30 days. Macroscopic evaluations were performed every other day, recording wound size (with a pachymeter) and occurrence of bleeding or exudates. Microscopically, at day 15 or 30, histologic and immunohistochemical studies were carried out with the complete removal of the wound or cicatricial region. Macroscopically, the povidone-iodine group showed faster wound contraction and healing rate than the control, yet, this difference was not statistically significant. Although, under clinical observation, the incised regions presented scar tissue, the histopathological evaluation of the respective specimens showed uncompleted healing process features. The hydrogen peroxide demonstrated promising results to the proposed intent. However, a bigger sample is needed to ascertain the found evidences. Furthermore, studies with longer or more frequent periods of substance exposure, along with devices to circumvent wound contraction and higher doses of analgesics, are recommended.