Molecular adaptations in Antarctic fish and bacteria

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The relative frequency of odontogenic tumors : a study of 376 cases in a Brazilian population

Odontogenic tumors (OTs) are rare lesions, exclusive of the jaws, that are derived from epithelial and/or ectomesenchymal elements of the tooth-forming apparatus. Their biological behavior is heterogeneous, including hamartomatous tissue proliferation, benign nonaggressive and aggressive neoplasms, and malignant tumors with metastatic capacity. The aim of this study was to describe the relative frequency of odontogenic tumors in a Brazilian population. In addition, a review of the literature identified studies on odontogenic tumors that follow the 2005 World Health Organization. A total of 376 cases of odontogenic tumors from an oral pathology service were reviewed about age, gender, anatomic site and histologic diagnosis. Keratocystic odontogenic tumors (31.6%) were the most common, followed by ameloblastoma (28.5%), and odontoma (22.6%). The mean age was 32.2 years, and more than half the patients (52.1%) were in the second and third decades of life. The male to female ratio was 1:1.37, with a maxilla to mandible ratio of 1:2.08. The variation in relative frequency of tumors observed among the several series, including the present study, is probably due in part to cultural differences between geographic areas but also to the study design

Hemoglobin is present as a canonical α2β2 tetramer in dopaminergic neurons

AbstractHemoglobin is the oxygen carrier in blood erythrocytes. Oxygen coordination is mediated by α2β2 tetrameric structure via binding of the ligand to the heme iron atom. This structure is essential for hemoglobin function in the blood. In the last few years, expression of hemoglobin has been found in atypical sites, including the brain. Transcripts for α and β chains of hemoglobin as well as hemoglobin immunoreactivity have been shown in mesencephalic A9 dopaminergic neurons, whose selective degeneration leads to Parkinson's disease. To gain further insights into the roles of hemoglobin in the brain, we examined its quaternary structure in dopaminergic neurons in vitro and in vivo. Our results indicate that (i) in mouse dopaminergic cell line stably over-expressing α and β chains, hemoglobin exists as an α2β2 tetramer; (ii) similarly to the over-expressed protein, endogenous hemoglobin forms a tetramer of 64kDa; (iii) hemoglobin also forms high molecular weight insoluble aggregates; and (iv) endogenous hemoglobin retains its tetrameric structure in mouse mesencephalon in vivo. In conclusion, these results suggest that neuronal hemoglobin may be endowed with some of the biochemical activities and biological function associated to its role in erythroid cells. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins

Anti-inflammatory Properties of Cannabidiol, a Nonpsychotropic Cannabinoid, in Experimental Allergic Contact Dermatitis

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Radiomics in Cross-Sectional Adrenal Imaging: A Systematic Review and Quality Assessment Study

In this study, we aimed to systematically review the current literature on radiomics applied to cross-sectional adrenal imaging and assess its methodological quality. Scopus, PubMed and Web of Science were searched to identify original research articles investigating radiomics applications on cross-sectional adrenal imaging (search end date February 2021). For qualitative synthesis, details regarding study design, aim, sample size and imaging modality were recorded as well as those regarding the radiomics pipeline (e.g., segmentation and feature extraction strategy). The methodological quality of each study was evaluated using the radiomics quality score (RQS). After duplicate removal and selection criteria application, 25 full-text articles were included and evaluated. All were retrospective studies, mostly based on CT images (17/25, 68%), with manual (19/25, 76%) and two-dimensional segmentation (13/25, 52%) being preferred. Machine learning was paired to radiomics in about half of the studies (12/25, 48%). The median total and percentage RQS scores were 2 (interquartile range, IQR = −5–8) and 6% (IQR = 0–22%), respectively. The highest and lowest scores registered were 12/36 (33%) and −5/36 (0%). The most critical issues were the absence of proper feature selection, the lack of appropriate model validation and poor data openness. The methodological quality of radiomics studies on adrenal cross-sectional imaging is heterogeneous and lower than desirable. Efforts toward building higher quality evidence are essential to facilitate the future translation into clinical practice

Solução Paralela em Agregado de PCs de um Código de Elementos Finitos Aplicado à Elasticidade Linear

Este trabalho apresenta os resultados comparativos de desempenho de códigos paralelos, baseados no método dos elementos finitos aplicado à elasticidade linear para problemas estruturais, que utilizam o método dos gradientes conjugados para solução do sistema de equações. Os programas foram executados em um agregado de PCs, por ser uma opção economicamente viável, já que utiliza tecnologia depurada de alta disponibilidade e confiabilidade e softwares de domínio público. Foram implementadas duas versões utilizando PVM e MPI. O desempenho dos programas paralelos foi medido pelos tempos de execução e speedup relativo, em função do tamanho do problema e do número de processadores

Intralesional corticosteroid injections in the treatment of central giant cell lesions of the jaws: a meta-analytic study

Objective: The aim of this study was to evaluate the response of treatment of central giant cell lesion to intral - esional corticosteroid injections. Study Design: Review of articles indexed in PubMed on the topic between the years 1988 and 2011, and develop - ment of a descriptive meta-analysis of the results. Results: Sample of 41 patients primarily treated with intralesional corticosteroid injections was obtained, with a male female ratio of 1:0.95, being 23 aggressive and 18 non-aggressive central giant cell lesions. Triamcinolone acetonide and triamcinolone hexacetonide were the drugs used, and 78.0% cases were considered as good result, 14.6% were considered as moderate response and 7.3% were considered as negative result to treatment. Consider - ing the aggressiveness, 88.9% of non-aggressive lesions presented a good response to treatment, in aggressive central giant cell lesions, 69.6% presented a good response to intralesional corticosteroid injections. Conclusion: In view of the results analyzed, intralesional corticosteroid injections could be considered as first treat - ment option for central giant cell lesion

EVOLUTIONARY ADAPTATIONS IN ANTARCTIC FISH: THE OXYGEN-TRANSPORT SYSTEM

Understanding molecular adaptations evolved in response to environmental temperature changes is essential, because temperature affects the kinetic energy of molecules and modifies molecular interactions, macromolecular stability/functioning and membrane features. Environmental oxygen availability may also play an important role in the evolution of polar marine organisms, as suggested by the physiological and biochemical strategies adopted by these organisms to acquire, deliver and scavenge oxygen.This review summarises the current knowledge on the structure and function of hemoglobins of fish living in Antarctic habitats. The variety of adaptations underlying the ability of Antarctic fish to survive at temperatures permanently close to freezing is unique among teleosts. The dominant perciform suborder Notothenioidei affords an excellent study group for elaborating the evolution of biochemical adaptation to temperature. The availability of notothenioid taxa living in a wide range of latitudes (Antarctic, sub-Antarctic, and temperate regions) offers a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost in response to cold and to reconstruct the likely evolutionary events modulating the ability to carry oxygen in freezing habitats. Although oxygen can be transported in freely dissolved form most animals rely on one or more protein carriers to deliver it to the respiring tissues. Compared to temperate and tropical species, high-Antarctic notothenioids have evolved reduced hemoglobin concentration/multiplicity. The Antarctic family Channichthyidae (the notothenioid crown group) is devoid of hemoglobin. All extant icefish species lack hemoglobin and many have lost myoglobin expression. In these species, oxygen delivery to tissues occurs by transport of the gas physically dissolved in the plasma.ADAPTACIONES EVOLUTIVAS EN PECES ANTÁRTICOS: EL SISTEMA DE TRANSPORTE DE OXÍGENO. Comprender las adaptaciones moleculares que han evolucionado en respuesta a los cambios de temperatura del medio ambiente es esencial, porque la temperatura afecta la energía cinética de las moléculas y  modiica  las  interacciones  moleculares,  la  estabilidad  de  las  macromoleculares,  sus  características  y  el funcionamiento de la membrana. La disponibilidad de oxígeno ambiental desempeña un papel importante en la evolución de los organismos marinos polares, como se evidencia en las estrategias isiológicas y bioquímicas adoptadas  por  estos  organismos  para  adquirir,  gastar  y  usar  oxígeno.  Esta  revisión  resume  el  conocimiento actual sobre la estructura y función de la hemoglobina de los peces que viven en hábitats antárticos. La amplia variedad de adaptaciones que permiten que los peces antárticos tengan la capacidad para sobrevivir de forma permanente en temperaturas cerca de la congelación es única entre los teleósteos. El suborden Notothenioidei, perteneciente a los Perciformes, es un excelente grupo para el estudio de la evolución y adaptación bioquímica a la temperatura. La gran variedad de taxones de nototénidos que viven en una amplia variedad de latitudes (Antártida, sub-antárticas, y las regiones templadas) ofrece una oportunidad extraordinaria para estudiar las características  isiológicas  y  bioquímicas  adquiridas  y  perdidas  por  este  grupo  en  respuesta  al  frío,  además de la posibilidad de reconstruir  los eventos más probables que direccionaron la evolución de la capacidad de transportar oxígeno en hábitats polares. Aunque el oxígeno puede ser transportado en su forma libre disuelta, la mayoría de los animales dependen de una o más proteínas para entregarlo a los tejidos para la respiración. En comparación con especies de zonas templadas y tropicales, los nototenoideos de la alta Antártida han evolucionado reduciendo la concentración y multiplicidad de hemoglobina. La familia antártica Channichthyidae (el grupo con corona de los Nototénidos) carece de la hemoglobina. Todas las especies de peces existentes que viven en el hielo carecen de hemoglobina y muchas han perdido la expresión de la mioglobina. En estas especies, el aporte de oxígeno a los tejidos se produce por el transporte del gas físicamente disuelto en el plasma. Palabras clave: Antártida; adaptaciones al frio; evolución; hemoglobina.ADAPTAÇÕES EVOLUTIVAS EM PEIXES ANTÁTRTICOS: O SISTEMA DE TRANSPORTE DE OXIGÊNIO.  Compreender as adaptações moleculares envolvidas na resposta às mudanças na temperatura  ambiental  é  essencial,  pois  a  temperatura  afeta  a  energia  cinética  das  moléculas  e  modiica  as interações moleculares, a estabilidade/funcionamento das macromoléculas e as características da membrana. A disponibilidade de oxigênio no ambiente pode também ter um importante papel na evolução dos organismos marinhos polares, como indicado pelas estratégias isiológicas e bioquímicas adotadas por estes organismos para adquirir, transportar e trocar oxigênio.   Esta revisão resume o conhecimento atual da estrutura e funcionamento das hemoglobinas de peixes que ocorrem em ambientes Antárticos. A diversidade de adaptações que sustentam a habilidade de peixes antárticos sobreviverem em temperaturas permanentemente próximas do congelamento é  única  entre  os  teleósteos.  A  dominante  sub-ordem  Perciforme  Notothenioidei  apresenta-se  como  um excelente  grupo  de  estudo  para  melhorar  o  conhecimento  sobre  a  evolução  das  adaptações  bioquímicas  à temperatura. A ocorrência de nototenióides em uma ampla variedade de latitudes (Antártica, sub-Antártica e regiões temperadas) oferece uma oportunidade notável para estudar as características isiológicas e bioquímicas obtidas  e,  por  outro  lado,  perdidas  em  resposta  ao  frio,  além  de  tornar  possível  a  reconstrução  dos  eventos evolutivos  que  provavelmente  modularam  a  habilidade  desses  peixes  de  transportar  oxigênio  em  ambientes extremamente frios. Embora  o  oxigênio  possa  ser  transportado  livremente  na  sua  forma  dissolvida,  a  maioria  dos  animais depende de um ou mais tipos de proteínas carreadoras para entregar o oxigênio aos tecidos. Quando comparadas às  espécies  temperadas  e  tropicais,  os  nototenióides  da  região Antártica,  propriamente  dita,  desenvolveram reduzida  concentração/multiplicidade  de  hemoglobinas.  A  família  de  peixes  Antárticos  Channichthyidae (crown group  nototenióide)  não  apresenta  hemoglobina.  Todas  as  espécies  de iceish  (peixes-do-gelo)  não possuem hemoglobinas e muitas também não produzem mioglobinas. Nessas espécies, o transporte de oxigênio aos tecidos ocorre através do gás isicamente dissolvido no plasma. Palavras-chave: Antártica; adaptações ao frio; evolução; hemoglobina