ABSTRACT
Plastination is an anatomical technique for preserving biological tissues based on the principle of replacing body fluids with a curable polymer. An inconvenient aspect of this technique is the tissue shrinkage it causes; several studies seek ways to reduce or avoid this shrinkage. Additionally, there are no studies in the literature that quantitatively evaluate the use of low viscosity silicones in plastination having shrinkage of tissue as a parameter. Therefore, this study aimed to evaluate the use of Silicones S10 (Biodur) and P1 (Polisil) in the plastination of different types of biological tissues of a sliced human body, having as a parameter the tissue shrinkage caused in the forced impregnation stage. Human cardiac, pulmonary, splenic, renal, hepatic, muscular, and bone tissues were analyzed. For such purpose, a male human body was used, sliced in 13-15-mm-thick pieces, having as a parameter the before and the after plastination with the different silicones. The standard protocol of the plastination of the slices was followed: dehydration, forced impregnation, and curation. Half of the pieces obtained were plastinated with silicone P1 (group P1) and the other half with S10 (group S10). All tissues and anatomical segments analyzed in this study showed less or equal shrinkage when plastination of the control group (S10) was compared with that of the P1 group. Therefore, we concluded that the lower viscosity silicone promoted less tissue shrinkage, making it a viable alternative to the reference.
Subject(s)
Plastination , Humans , Kidney , Male , Plastination/methods , Polymers , Silicones , ViscosityABSTRACT
Plastination is an anatomical technique for preserving biological tissues based on the principle of replacing body fluids with a curable polymer. An inconvenient aspect of this technique is the tissue shrinkage it causes; several studies seek ways to reduce or avoid this shrinkage. Additionally, there are no studies in the literature that quantitatively evaluate the use of low viscosity silicones in plastination having shrinkage of tissue as a parameter. Therefore, this study aimed to evaluate the use of Silicones S10 (Biodur) and P1 (Polisil) in the plastination of different types of biological tissues of a sliced human body, having as a parameter the tissue shrinkage caused in the forced impregnation stage. Human cardiac, pulmonary, splenic, renal, hepatic, muscular, and bone tissues were analyzed. For such purpose, a male human body was used, sliced in 13-15-mm-thick pieces, having as a parameter the before and the after plastination with the different silicones. The standard protocol of the plastination of the slices was followed: dehydration, forced impregnation, and curation. Half of the pieces obtained were plastinated with silicone P1 (group P1) and the other half with S10 (group S10). All tissues and anatomical segments analyzed in this study showed less or equal shrinkage when plastination of the control group (S10) was compared with that of the P1 group. Therefore, we concluded that the lower viscosity silicone promoted less tissue shrinkage, making it a viable alternative to the reference.
ABSTRACT
The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.
