A functional family of fluorescent nucleotide analogues to investigate actin dynamics and energetics.

Actin polymerization provides force for vital processes of the eukaryotic cell, but our understanding of actin dynamics and energetics remains limited due to the lack of high-quality probes. Most current probes affect dynamics of actin or its interactions with actin-binding proteins (ABPs), and cannot track the bound nucleotide. Here, we identify a family of highly sensitive fluorescent nucleotide analogues structurally compatible with actin. We demonstrate that these fluorescent nucleotides bind to actin, maintain functional interactions with a number of essential ABPs, are hydrolyzed within actin filaments, and provide energy to power actin-based processes. These probes also enable monitoring actin assembly and nucleotide exchange with single-molecule microscopy and fluorescence anisotropy kinetics, therefore providing robust and highly versatile tools to study actin dynamics and functions of ABPs.

Determination of the value of vertebral heart size regarding the weight and body area in canines / Determinação dos valores do vertebral heart size em relação ao peso e área corporal canina

The vertebral heart size is a method used to measure the cardiac dimension in order to identify the remodeling of the chambres in heart disease. This study aims to determinate the vertebral heart size values at right lateral and ventrodorsal radiographs views relating to canines weight and body area variations. For the purpose of the study 40 healthy dogs within the age of 1 to 6 years, males and females, with deep or intermediated thorax were selected, brachycephalic dogs were not included in the study; the dogs were separated in four groups: group 1(n=9) compound of dogs up to 5 kg; group 2 (n=8) with dogs from 5,1 to 10 kg; group 3 (n=12) with dogs from 10,1 to19 kg and group 4 (n=11) with dogs weighing more than 19,1 kg. The values of body score, body mass index and the thorax configuration where previously measured, as well as the VHS and the depth width ratio from the radiographs. The results demonstrated intervals of right lateral-lateral vertebral heart size 9.9 to 10.4v and ventro-dorsal vertebral heart size of 9.8-10.3v. The study results show that the vertebral heart size numbers did not correlate with weight or body area, regardless the type of radiography view. Therefore, it can be concluded that the vertebral heart size in right lateral and ventrodorsal radiography can be used to rate the cardiac area, not suffering influence by the dog's weight or body area.

O vertebral heart size é um método utilizado para mensurar a dimensão cardíaca visando identificar os remodelamentos das câmaras nas cardiopatias. O objetivo do estudo foi determinar os valores de vertebral heart size nas projeções radiográficas latero-lateral direita e ventro-dorsal conforme as variações do peso e área corporal. Para isso, foram selecionados 40 cães hígidos com idade entre 1 e 6 anos, machos e fêmeas, com padrão torácico intermediário e profundo, com exclusão dos braquicefálicos; os cães foram divididos em quatro grupos: grupo 1 (n=9) composto por cães de até 5 kg; grupo 2 (n=8) com cães de 5,1 a 10 kg; grupo 3 (n=12) com cães de 10,1 a 19 kg e grupo 4 (n=11) com cães acima de 19,1 kg. Os valores de escore corporal, índice de massa corporal e conformação torácica foram previamente mensurados, bem como os valores dos vertebral heart size a relação profundidade/largura torácica das radiografias. Os resultados demonstraram intervalos de vertebral heart size latero-lateral 9.9 a 10.4v e vertebral heart size ventro dorsal de 9.8-10.3v. Os valores não apresentaram correlação com o peso e área corporal nos grupos estudados, independente das projeções estudas. Assim, pode-se concluir que método vertebral heart size nas projeções estudadas é aplicável na avaliação da área cardíaca, não sofrendo influências do peso e área corporal canina.

Determination of the value of vertebral heart size regarding the weight and body area in canines / Determinação dos valores do vertebral heart size em relação ao peso e área corporal canina

The vertebral heart size is a method used to measure the cardiac dimension in order to identify the remodeling of the chambres in heart disease. This study aims to determinate the vertebral heart size values at right lateral and ventrodorsal radiographs views relating to canines weight and body area variations. For the purpose of the study 40 healthy dogs within the age of 1 to 6 years, males and females, with deep or intermediated thorax were selected, brachycephalic dogs were not included in the study; the dogs were separated in four groups: group 1(n=9) compound of dogs up to 5 kg; group 2 (n=8) with dogs from 5,1 to 10 kg; group 3 (n=12) with dogs from 10,1 to19 kg and group 4 (n=11) with dogs weighing more than 19,1 kg. The values of body score, body mass index and the thorax configuration where previously measured, as well as the vertebral heart size and the depth width ratio from the radiographs. The results demonstrated intervals of right lateral-lateral vertebral heart size 9.9 to 10.4v and ventro-dorsal vertebral heart size of 9.8-10.3v. The study results show that the vertebral heart size numbers did not correlate with weight or body area, regardless the type of radiography view. Therefore, it can be concluded that the vertebral heart size in right lateral and ventrodorsal radiography can be used to rate the cardiac area, not suffering influence by the dog's weight or body area.

O vertebral heart size é um método utilizado para mensurar a dimensão cardíaca visando identificar os remodelamentos das câmaras nas cardiopatias. O objetivo do estudo foi determinar os valores de vertebral heart size nas projeções radiográficas latero-lateral direita e ventro-dorsal conforme as variações do peso e área corporal. Para isso, foram selecionados 40 cães hígidos com idade entre 1 e 6 anos, machos e fêmeas, com padrão torácico intermediário e profundo, com exclusão dos braquicefálicos; os cães foram divididos em quatro grupos: grupo 1 (n=9) composto por cães de até 5 kg; grupo 2 (n=8) com cães de 5,1 a 10 kg; grupo 3 (n=12) com cães de 10,1 a 19 kg e grupo 4 (n=11) com cães acima de 19,1 kg. Os valores de escore corporal, índice de massa corporal e conformação torácica foram previamente mensurados, bem como os valores dos vertebral heart size a relação profundidade/largura torácica das radiografias. Os resultados demonstraram intervalos de vertebral heart size latero-lateral 9.9 a 10.4v e vertebral heart size ventro dorsal de 9.8-10.3v. Os valores não apresentaram correlação com o peso e área corporal nos grupos estudados, independente das projeções estudas. Assim, pode-se concluir que método vertebral heart size nas projeções estudadas é aplicável na avaliação da área cardíaca, não sofrendo influências do peso e área corporal canina.

Sizes of actin networks sharing a common environment are determined by the relative rates of assembly.

Within the cytoplasm of a single cell, several actin networks can coexist with distinct sizes, geometries, and protein compositions. These actin networks assemble in competition for a limited pool of proteins present in a common cellular environment. To predict how two distinct networks of actin filaments control this balance, the simultaneous assembly of actin-related protein 2/3 (Arp2/3)-branched networks and formin-linear networks of actin filaments around polystyrene microbeads was investigated with a range of actin accessory proteins (profilin, capping protein, actin-depolymerizing factor [ADF]/cofilin, and tropomyosin). Accessory proteins generally affected actin assembly rates for the distinct networks differently. These effects at the scale of individual actin networks were surprisingly not always correlated with corresponding loss-of-function phenotypes in cells. However, our observations agreed with a global interpretation, which compared relative actin assembly rates of individual actin networks. This work supports a general model in which the size of distinct actin networks is determined by their relative capacity to assemble in a common and competing environment.

The polyplex, protein corona, cell interplay: Tips and drawbacks.

Polyplexes (PX) are soft materials, obtained by blending polycations and nucleic acids, designed for gene delivery applications. While much is known about the transfection properties of PX, their protein corona, the biomolecules interacting with colloids once in a biological environment, represents an underlooked parameter in gene transfection. In this study, linear and branched polyethylenimines (lPEI and bPEI), the golden standard among non-viral vectors, were selected and used throughout the work: their physicochemical properties and protein corona when complexed to DNA were studied and linked to the toxicity and transfection efficiency arisen upon their delivery to cells. Interestingly, lPEIDNA and bPEIDNA complexes were characterized by similar physicochemical features, but different biological behavior. In fact, the biological milieu where cells and PX interact greatly influences their size, stability and transfection abilities. Using PX as a soft material model system, we spotlighted structure-activity relationships and methodologies that can help interpret their biological behavior and guide future studies in the field.