Lasting Developmental Effects of Neonatal Fentanyl Exposure in Preweanling Rats

The present study aimed to determine whether neonatal treatment with fentanyl has lasting effects on stressed developing brain. Six-day-old rats were assigned to one of three groups (10 males/group): (1) fentanyl (incision+fentanyl), (2) saline (incision+0.9% saline), and (3) unoperated (unoperated sham). Pups with a plantar paw incision received repetitive subcutaneous injections of fentanyl or vehicle through postnatal days (PNDs) 6 to 8. A nonoperated sham group served as nonstressed control. Studies included assessment of development from PND 6 to PND 21 (growth indices and behavioral testing). Fentanyl administered twice daily for three days after surgical incision had no impact on early growth and development, as measured on PND 9, but showed a lasting impact on later growth, enhanced behavioral development, and lower anxiety, as measured through PNDs 10–21. While this does not completely support a benefit from such treatment, our findings may contribute to support the neonatal use of fentanyl, when indicated, even in premature newborns

Anestesia Pediátrica em Período de Imaturidade Cerebral e Perturbações do Neurodesenvolvimento

INTRODUCTION: Several experimental and clinical studies suggest that drugs used in pediatric anesthesia may exert undesirable effects on the developing central nervous system. The objective of this review was to assess the results and conclusions of published studies on long lasting neurodevelopment disorders following exposure to anesthetics in children in a phase of brain immaturity. MATERIAL AND METHODS: We performed a literature search in several sources (PubMed, SciELO and Cochrane Library) using the terms 'Pediatric anesthesia OR Pediatric anesthetic OR Developing brain anesthetic OR Developing brain anesthesia AND behavior disorders'. We selected human studies, referring to long lasting neurodevelopment effects after exposure to anesthetics in the first four years of life. RESULTS: Ten retrospective studies met the inclusion criteria. Of these, seven suggest risk of neurobehavioral disorders after exposure of small children to anesthetics, as opposed to the results obtained by the other three. DISCUSSION: Although mostly using large databases, the studies found are retrospective, vary in test groups, include sometimes avoidable confounders and some present inaccuracies in the choice of the test and control populations that can compromise the reliability of the results. CONCLUSION: Because of the numerous limitations of the few studies available, the reported results are still deemed insufficient to change current clinical practice. However, although it is undisputable that anesthesia should be provided when needed, regardless of age, the warnings found in literature are worrisome, therefore whenever surgery is unavoidable in small children, alternatives that may help reduce the risks of anesthetic exposure should be sought.info:eu-repo/semantics/publishedVersio

Synthesis and characterization of new methacrylate based hydrogels

Hidrogéis têm sido utilizados para diversas aplicações, incluindo produção de lentes de contato, produtos sanitários e materiais para encerramento de ferimentos. O objetivo deste trabalho consistiu no desenvolvimento de novos hidrogéis a base de metacrilato. Estes materiais apresentam a vantagem de serem facilmente produzidos com diferentes composições e conseqüentemente com distintas permeabilidades e padrões de difusão. Por este motivo, torna-se possível sintetizar hidrogéis que possam ser usados para imobilizar uma grande variedade de compostos, tais como fármacos, proteínas ou mesmo células e tecidos. Neste trabalho foram preparados diferentes polímeros baseados em monômeros de metacrilato. A sua caracterização foi realizada através de diferentes técnicas, como Espectroscopia no Infravermelho com Transformada de Fourier (FTIR), avaliação da capacidade de intumescimento, Calorimetria Diferencial de Varredura (DSC) e avaliação das propriedades mecânicas. A sua toxicidade subaguda subcutânea foi também determinada utilizando ratos Wistar.Hydrogels have been used for several applications, including production of contact lenses, sanitary products and materials for wound dressing. The aim of this work was the development of new methacrylate based hydrogels. These materials present the advantage of being easily produced with different compositions and consequently different permeability and diffusion patterns. Therefore it becomes possible to synthesize hydrogels that can be used to immobilize a variety of compounds, such as drugs, proteins or even cells. During this work new polymers based on methacrylate monomers were prepared. Their characterization was accomplished by several techniques, e.g. Fourier Transform Infrared Spectroscopy (FTIR), swelling measurement, Differential Scanning Calorimetry (DSC) and evaluation of mechanical properties. Their subacute subcutaneous toxicity was also evaluated by using Wistar rats

Effects on gastric mucosa induced by dental bleaching – an experimental study with 6% hydrogen peroxide in rats

The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed.Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals.Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa.Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group.Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized

Teses

Apresentação dos resumos e abstracts de algumas teses de doutoramento defendidas na Universidade Lusófona, na área da Educação

Contribuição para o estudo do carcinoma colo-rectal.

Estudaram-se 401 neoplasias colo-rectais no que se refere à sua macroscopia e microscia, usando técnicas de histoquímica e imunocitoquímica para avaliação morfológicas. Os parâmetros morfológicos macroscópicos, avaliados foram: Diâmetro máximo da neoplasia, localização da neoplasia, tipo macroscópico e complicações. Os parâmetros morfológicos microscópicos, avaliados foram: Padrão de crescimento, tipo histológico, grau de diferenciação, profundidade da lesão, metástases ganglionares e de órgão, invasão vascular, fibrose do estroma, infiltrado inflamatório, mitoses, atipias, padrão de mucinas e os graus de Dukes, estadio TNM e estadio DNM. Foram ainda realizados estudos de imunocitoquímica para a caracterização das lesões quanto à presença de antigénio carcinoembrionário, Hormona coriópnica gonadotrófica, B2, microglobulina, hialuronidase e proteína P 170. Os vários parâmetros foram correlacionados entre si com a sobrevida, avaliando de que forma e quais, em conjunto ou isoladamente, podem ser bons indicadores de sobrevida. Este estudo foi complementado com um estudo de xenotransplante de neoplasia colorrectal humana sob a cápsula do rim do rato Wistar subcutaneamente no murganho atímico para caracterização das alterações fenotípicas durante o xenotransplante, com eventual interesse para ensaios terapêuticos. Foi igualmente caracterizado um modelo experimental de neoplasia colorectal no rato, para estudos de quimioprevenção. Este modelo foi caracterizado pelo estudo radiológico e anatomopatológico das lesões. A avaliação Anatomopatológica compreendeu: Localização das lesões, dimensão das lesões - volume, tipo histológico, produção de mucinas e superfície colagénica. Foi ainda introduzido o conceito de superfície de contacto, como toda a superfície de contacto do tecido neoplásico com o tecido não neoplásico

Lasting Developmental Effects of Neonatal Fentanyl Exposure in Preweanling Rats

The present study aimed to determine whether neonatal treatment with fentanyl has lasting effects on stressed developing brain. Six-day-old rats were assigned to one of three groups (10 males/group): (1) fentanyl (incision+fentanyl), (2) saline (incision+0.9% saline), and (3) unoperated (unoperated sham). Pups with a plantar paw incision received repetitive subcutaneous injections of fentanyl or vehicle through postnatal days (PNDs) 6 to 8. A nonoperated sham group served as nonstressed control. Studies included assessment of development from PND 6 to PND 21 (growth indices and behavioral testing). Fentanyl administered twice daily for three days after surgical incision had no impact on early growth and development, as measured on PND 9, but showed a lasting impact on later growth, enhanced behavioral development, and lower anxiety, as measured through PNDs 10-21. While this does not completely support a benefit from such treatment, our findings may contribute to support the neonatal use of fentanyl, when indicated, even in premature newborns