A Relationship between the Structures and Neurotoxic Effects of Aß Oligomers Stabilized by Different Metal Ions.

Oligomeric assemblies of the amyloid ß peptide (Aß) have been investigated for over two decades as possible neurotoxic agents in Alzheimer's disease. However, due to their heterogeneous and transient nature, it is not yet fully established which of the structural features of these oligomers may generate cellular damage. Here, we study distinct oligomer species formed by Aß40 (the 40-residue form of Aß) in the presence of four different metal ions (Al3+, Cu2+, Fe2+, and Zn2+) and show that they differ in their structure and toxicity in human neuroblastoma cells. We then describe a correlation between the size of the oligomers and their neurotoxic activity, which provides a type of structure-toxicity relationship for these Aß40 oligomer species. These results provide insight into the possible role of metal ions in Alzheimer's disease by the stabilization of Aß oligomers.

Hematological change parameters in patients with pressure ulcer at long-term care hospital.

OBJECTIVE: To assess factors associated with the development of pressure ulcers, and to compare the effectiveness of pharmacological treatments. METHODS: The factors associated with the development of pressure ulcers were compared in lesion-carrying patients (n=14) and non-carriers (n=16). Lesion-carrying patients were treated with 1% silver sulfadiazine or 0.6IU/g collagenase and were observed for 8 weeks. The data collected was analyzed with p<0.05 being statistically relevant. RESULTS: The prevalence of pressure ulcers was about 6%. The comparison of carrier and non-carrier groups of pressure ulcers revealed no statistically significant difference in its occurrence with respect to age, sex, skin color, mobility, or the use of diapers. However, levels of hemoglobin, hematocrit, and red blood cells were found to be statistically different between groups, being lower in lesion-carrying patients. There was no significant difference found in lesion area between patients treated with collagenase or silver sulfadiazine, although both groups showed an overall reduction in lesion area through the treatment course. CONCLUSION: Hematologic parameters showed a statistically significant difference between the two groups. Regarding the treatment of ulcers, there was no difference in the area of the lesion found between the groups treated with collagenase and silver sulfadiazine.

Hematological change parameters in patients with pressure ulcer at long-term care hospital / Alterações dos parâmetros hematológicos em pacientes portadores de úlcera por pressão em um hospital de longa permanência

Objective To assess factors associated with the development of pressure ulcers, and to compare the effectiveness of pharmacological treatments. Methods The factors associated with the development of pressure ulcers were compared in lesion-carrying patients (n=14) and non-carriers (n=16). Lesion-carrying patients were treated with 1% silver sulfadiazine or 0.6IU/g collagenase and were observed for 8 weeks. The data collected was analyzed with p<0.05 being statistically relevant. Results The prevalence of pressure ulcers was about 6%. The comparison of carrier and non-carrier groups of pressure ulcers revealed no statistically significant difference in its occurrence with respect to age, sex, skin color, mobility, or the use of diapers. However, levels of hemoglobin, hematocrit, and red blood cells were found to be statistically different between groups, being lower in lesion-carrying patients. There was no significant difference found in lesion area between patients treated with collagenase or silver sulfadiazine, although both groups showed an overall reduction in lesion area through the treatment course. Conclusion Hematologic parameters showed a statistically significant difference between the two groups. Regarding the treatment of ulcers, there was no difference in the area of the lesion found between the groups treated with collagenase and silver sulfadiazine. .

Objetivo Avaliar os fatores associados ao desenvolvimento da úlcera por pressão e comparar a efetividade de tratamentos farmacológicos. Métodos Os fatores associados ao desenvolvimento de úlcera por pressão foram comparados entre pacientes portadores (n=14) e não portadores (n=16) da lesão. Os pacientes com a ferida foram tratados com sulfadiazina de prata 1% ou colagenase 0,6UI/g, sendo acompanhados durante 8 semanas. Os dados coletados foram analisados considerando-se estatisticamente significativo se p<0,05. Resultados A prevalência de úlcera por pressão foi de cerca de 6%. A comparação entre os grupos de portadores e não portadores de úlcera por pressão não revelou diferença estatística significativa entre ocorrência desta segundo idade, sexo, cor da pele, mobilidade e uso de fralda. Por outro lado, os valores de hemoglobina, hematócrito e hemácias foram estatisticamente diferentes entre os grupos, sendo menor naqueles pacientes portadores da lesão. Não houve diferença significativa na área da lesão entre aqueles pacientes tratados com colagenase ou sulfadiazina de prata, embora ambos os tratamentos tenham evidenciado uma redução média da área da lesão. Conclusão Os parâmetros hematológicos apresentaram diferença estatística entre os dois grupos avaliados, ao contrário das demais variáveis analisadas. Em relação ao tratamento das úlceras, não houve diferença na área da lesão na comparação entre a colagenase e a sulfadiazina. .