Expressão da progranulina durante os primeiros estágios de desenvolvimento hepático em ratos Fischer 344

Transplants are the only effective therapy for the treatment of advanced liver diseases such as cirrhosis. Given the limited number of organ donors, regenerative medicine has sought for sources of cells and tissues for replacement therapy. Embryonic stem cells are a promising source of material for transplantation because of their exclusive property of being expanded indefinitely in culture, thus, they are a source of replacement tissue. Moreover, they are capable of differentiating into practically all cell types, and may be utilized in replacement therapy in various diseases. The liver bud has bipotent stem cells that have not yet differentiated into hepatocytes or biliary duct cells; however, they have great potential of proliferation and differentiation. Thus, the challenge is to identify methods that promote their differentiation in specific and functional strains. This study aimed to evaluate the role of the progranulin growth factor PGRN during the liver development of rats F344, since this growth factor could be utilized in protocols of differentiation of stem cells of the liver bud in functional hepatocytes. The results showed that PGRN is present during different periods of hepatogenesis in F344 rats, and that this growth factor should be involved in the process of differentiation of hepatoblasts into hepatocytes after activation by HNF4α , however, PGRN seems not to exert a cellular proliferation function during the hepatogenesis. Thus, PGRN can be used in future protocols of liver cell differentiation directed toward cellular therapy in Regenerative Medicine.Os transplantes são a única terapia eficaz para o tratamento de doenças hepáticas avançadas, como a cirrose. Dado o número limitado de doadores de órgãos, a medicina regenerativa tem procurado fontes de células para a terapia de substituição. As células embrionárias são uma fonte promissora de material para o transplante devido à sua propriedade exclusiva de ser expandida indefinidamente em cultura, assim, elas são uma fonte de tecido de substituição. Além disso, são capazes de se diferenciar em praticamente todos os tipos celulares, e podem ser utilizadas na terapia de substituição em várias doenças. O broto hepático tem células-tronco (CT) bipotenciais que ainda não se diferenciam em hepatócitos ou células do ducto biliar, contudo, elas têm um grande potencial de proliferação e de diferenciação. Desse modo, o desafio é identificar métodos que promovam sua diferenciação em linhagens específicas e funcionais. Este estudo teve como objetivo avaliar o papel do fator de crescimento progranulina (PGRN) durante o desenvolvimento hepático em ratos F344, uma vez que a PGRN poderia ser utilizada em protocolos de diferenciação de CT do broto hepático em hepatócitos funcionais. Os resultados mostraram que PGRN está presente durante diferentes períodos da hepatogênese em ratos F344, e que a mesma deve estar envolvida no processo de diferenciação de hepatoblastos em hepatócitos após ativação por HNF4α, no entanto, a PGRN parece não desempenhar uma função de proliferação celular durante a hepatogênese. Assim, a PGRN pode ser usada em futuros protocolos de diferenciação de células hepáticas voltadas para a terapia celular na medicina regenerativa

Morphological evaluation of fetal membranes and placenta of wild life Mazama gouazoubira deer in the first third of pregnancy

Mazama gouazoubira, o veado-catingueiro, é uma espécie de cervídeo de porte pequeno, que pode ser encontrado na América do Sul, desde o sul do Uruguai até o norte de Mato Grosso, no Brasil. Este estudo teve como objetivo descrever as membranas fetais e a placenta de M. gouazoubira no terço inicial de gestação. As amostras coletadas foram analisadas macroscopicamente e microscopicamente. O exame do útero demonstrou uma gestação univitelina e um embrião com crown-rump de 13mm. Na análise do embrião pode ser observado o olho pigmentado, as saliências auriculares, o mesonefro e e metanefro em desenvolvimento, o fígado e sua proeminência externa, o estômago, os membros torácicos e os brotos dos membros pélvicos. A placenta apresentou-se oligocotiledonária e no útero puderam ser observadas nove carúnculas. O saco gestacional mediu 15cm de comprimento e, como observado no início da gestação dos ruminantes domésticos, os cotilédones não puderam ser identificados macroscopicamente. Uma fraca adesão foi observada entre as carúnculas e a membrana corioalantóica (cotilédones) que formavam os placentônios. A membrana corioalantóica demonstrou um alantóide bem vascularizado composto por uma fina camada de células de núcleos e citoplasmas alongados. Na outra face da membrana, o cório foi composto por células cúbicas, de citoplasmas escassos e núcleos grandes e arredondados, características de células trofoblásticas. Envolvendo o embrião visualizou-se o saco amniótico constituído de duas camadas passíveis de separação mecânica, que apresentaram morfologia similar, sendo formadas por um epitélio pavimentoso avascular. Não foi observado saco vitelino no estágio gestacional do espécime estudado. Conclui-se que a placenta de M. gouazoubira é oligocotiledonária, como observado em outros cervídeos, e que as membranas fetais apresentam semelhanças com a de outros ruminantes, incluindo as características citológicas. Estudos adicionais são necessários para determinar a presença do saco vitelino e quando ocorre sua regressão.Mazama gouazoubira is a small-sized deer, which can be found in South America, from southern Uruguay to the north of Mato Grosso, Brazil. This study aimed to describe the fetal membranes and placenta of M. gouazoubira in the first third of pregnancy. Samples collected were macroscopically and microscopically analyzed. Uterus examination demonstrated univitelinic gestation with an embryo measuring a crown-rump length of 13mm. In the embryo analysis we could identify the pigmented eye, auricular hillocks, mesonephron and early metanephron, liver and its external prominence, stomach, thoracic members and buds of pelvic members. Placenta was oligocotyledonary and nine caruncles were found in the uterus. Gestational sac measured 15cm in length, and, as observed in the early gestation of domestic ruminants, cotyledons could not be identified macroscopically. A weak adhesion was found between caruncles and chorioallantoic membrane (cotyledons) forming the placentomes. The chorioallantoic membrane showed a well-vascularized allantoid composed by a thin layer of cells with stretched nucleus and cytoplasm. On the other side of the membrane, the chorion was composed by cubic cells with scant cytoplasm and large-rounded nuclei, features of trophoblast cells. Involving the embryo we identified a two-layered amniotic sac. Layers could be mechanically separated and had similar morphology, showing a non-vascularized squamous epithelium. There was no yolk sac in the gestational stage of this specimen. We concluded that the placenta of M. gouazoubira is an oligocotyledonary placenta, as observed in others cervids, and that the fetal membranes showed similarities with those from other domestic ruminants, including cytological characteristics. Further studies are required in order to determine the presence of the yolk sac and its regression time

Nanofibrous antibiotic‐eluting matrices: Biocompatibility studies in a rat model

This study evaluated the biocompatibility of degradable polydioxanone (PDS) electrospun drug delivery systems (hereafter referred as matrices) containing metronidazole (MET) or ciprofloxacin (CIP) after subcutaneous implantation in rats. Sixty adult male rats were randomized into six groups: SHAM (sham surgery); PDS (antibiotic‐free matrix); 1MET (one 25 wt% MET matrix); 1CIP (one 25 wt% CIP matrix); 2MET (two 25 wt% MET matrices); and 2CIP (two 25 wt% CIP matrices). At 3 and 30 days, animals were assessed for inflammatory cell response (ICR), collagen fibers degradation, and oxidative profile (reactive oxygen species [ROS]; lipid peroxidation [LP]; and protein carbonyl [PC]). At 3 days, percentages of no/discrete ICR were 100, 93.3, 86.7, 76.7, 50, and 66.6 for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP, respectively. At 30 days, percentages of no/discrete ICR were 100% for SHAM, PDS, 1MET, and 1CIP and 93.3% for 2MET and 2CIP. Between 3 and 30 days, SHAM, 1CIP, and 2CIP produced collagen, while 1MET and 2MET were unchanged. At 30 days, the collagen fiber means percentages for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP were 63.7, 60.7, 56.6, 62.6, 51.8, and 61.7, respectively. Antibiotic‐eluting matrices showed similar or better oxidative behavior when compared to PDS, except for CIP‐eluting matrices, which showed higher levels of PC compared to SHAM or PDS at 30 days. Collectively, our findings indicate that antibiotic‐eluting matrices may be an attractive biocompatible drug delivery system to fight periodontopathogens. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 2019.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152674/1/jbmb34389.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152674/2/jbmb34389_am.pd

In vitro evaluation of modified surface microhardness measurement, focus variation 3D microscopy and contact stylus profilometry to assess enamel surface loss after erosive-abrasive challenges

The aim of the study was to compare surface loss values after erosion-abrasion cycles obtained with modified surface microhardness measurement (mSMH), focus variation 3D microscopy (FVM) and contact stylus profilometry (CSP). We cut human molars into buccal and lingual halves, embedded them in resin and ground 200 μm of enamel away. The resulting surfaces were polished. To maintain a reference area, we applied Block-Out resin to partly cover the enamel surface. The samples were incubated in artificial saliva (37°C; 1 h), then rinsed in deionized water (10 s) and dried with oil-free air (5 s). We immersed the specimens individually in 30 mL citric acid (1%, pH 3.6) for 2 min (25°C, 70 rpm dynamic conditions) before brushing them (50 strokes, 200 g) in an automatic brushing machine with toothpaste-slurry. We calculated the surface loss as per mSMH, by re-measuring the length of the same six indentations made before the abrasive challenge. The experiment consisted of five experimental groups that received between 2 and 10 erosion-abrasion cycles. Each group contained 15 specimens and samples in groups 1, 2, 3, 4 and 5 underwent a total of 2, 4, 6, 8 and 10 cycles, respectively. The resin was removed from the reference area in one piece under 10× magnification and the FVM and CSP were performed. Agreement between the methods was calculated with the intraclass correlation coefficient (ICC) and depicted in Bland-Altman plots. All methods presented a linear pattern of surface loss measurements throughout the experiment, leading overall to a strong, statistically significant correlation between the methods (ICC = 0.85; p<0.001). So, despite the different surface loss values, all methods presented consistent results for surface loss measurement

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery