185 research outputs found
Cellular Hyperproliferation and Cancer as Evolutionary Variables
Technological advances in biology have begun to dramatically change the way we think about evolution, development, health and disease. The ability to sequence the genomes of many individuals within a population, and across multiple species, has opened the door to the possibility of answering some long-standing and perplexing questions about our own genetic heritage. One such question revolves around the nature of cellular hyperproliferation. This cellular behavior is used to effect wound healing in most animals, as well as, in some animals, the regeneration of lost body parts. Yet at the same time, cellular hyperproliferation is the fundamental pathological condition responsible for cancers in humans. Here, I will discuss why microevolution, macroevolution and developmental biology all have to be taken into consideration when interpreting studies of both normal and malignant hyperproliferation. I will also illustrate how a synthesis of evolutionary sciences and developmental biology through the study of diverse model organisms can inform our understanding of both health and disease
Slicing across Kingdoms: Regeneration in Plants and Animals
Multicellular organisms possessing relatively long life spans are subjected to diverse, constant, and often intense intrinsic and extrinsic challenges to their survival. Animal and plant tissues wear out as part of normal physiological functions and can be lost to predators, disease, and injury. Both kingdoms survive this wide variety of insults by strategies that include the maintenance of adult stem cells or the induction of stem cell potential in differentiated cells. Repatterning mechanisms often deploy embryonic genes, but the question remains in both plants and animals whether regeneration invokes embryogenesis, generic patterning mechanisms, or unique circuitry comprised of well-established patterning genes
Stem cells and the Planarian <i>Schmidtea mediterranea</i>
In recent years, somatic stem cells have been heralded as potential therapeutic agents to address a large number of degenerative diseases. Yet, in order to rationally utilize these cells as effective therapeutic agents, and/or improve treatment of stem-cell-associated malignancies such as leukemias and carcinomas, a better understanding of the basic biological properties of stem cells needs to be acquired. A major limitation in the study of somatic stem cells lies in the difficulty of accessing and studying these cells in vivo. This barrier is further compounded by the limitations of in vitro culture systems, which are unable to emulate the microenvironments in which stem cells reside and which are known to provide critical regulatory signals for their proliferation and differentiation. Given the complexity of vertebrate adult somatic stem cell populations and their relative inaccessibility to in vivo molecular analyses, the study of somatic stem cells should benefit from analyzing their counterparts in simpler model organisms. In the past, the use of Drosophila or C. elegans has provided invaluable contributions to our understanding of genes and pathways involved in a variety of human diseases. However, stem cells in these organisms are mostly restricted to the gonads, and more importantly neither Drosophila, nor C. elegans are capable of regenerating body parts lost to injury. Therefore, a simple animal with experimentally accessible stem cells playing a role in tissue maintenance and/or regeneration should be very useful in identifying and functionally testing the mechanisms regulating stem cell activities. The planarian Schmidtea mediterranea is poised to fill this experimental gap. S. mediterranea displays robust regenerative properties driven by an adult, somatic stem cell population capable of producing the ∼40 different cell types found in this organism, including the germ cells. Given that all known metazoans depend on stem cells for their survival, it is extremely likely that the molecular events regulating stem cell biology would have been conserved throughout evolution, and that the knowledge derived from studying planarian stem cells could be vertically integrated to the study of vertebrate somatic stem cells. Current efforts, therefore, are aimed at further characterizing the somatic population of planarian stem cells in order to define its suitability as a model system in which to mechanistically dissect the basic biological attributes of metazoans stem cells
Comparative and transcriptome analyses uncover key aspects of coding-and long noncoding RNAs in flatworm mitochondrial genomes
Exploiting the conservation of various features of mitochondrial genomes has been instrumental in resolving phylogenetic relationships. Despite extensive sequence evidence, it has not previously been possible to conclusively resolve some key aspects of flatworm mitochondrial genomes, including generally conserved traits, such as start codons, noncoding regions, the full complement of tRNAs, and whether ATP8 is, or is not, encoded by this extranuclear genome. In an effort to address these difficulties, we sought to determine the mitochondrial transcriptomes and genomes of sexual and asexual taxa of freshwater triclads, a group previously poorly represented in flatworm mitogenomic studies. We have discovered evidence for an alternative start codon, an extended cox1 gene, a previously undescribed conserved open reading frame, long noncoding RNAs, and a highly conserved gene order across the large evolutionary distances represented within the triclads. Our findings contribute to the expansion and refinement of mitogenomics to address evolutionary issues in this diverse group of animals
J-Wave, predictor of sudden death
El sÃndrome de repolarización precoz el cual está determinado por el punto J y el
segmento S-T en el electrocardiograma, anteriormente se creÃa que era un patrón benigno. En
las últimas décadas se ha demostrado su carácter maligno cuando se presenta en las derivaciones
inferiores y/o las laterales dado su potencial para desencadenar arritmias letales (ocurre en un
1-13% de la población general y en un 15-70% de los casos de fibrilación ventricular idiopática),
como es el caso de la taquicardia ventricular polimórfica idiopática que puede degenerar en
la fibrilación ventricular y la muerte súbita. Se presenta el caso de una paciente de 41 a˜nos
de edad, quien presenta inicialmente episodios de palpitaciones, sÃncope y muerte súbita en
quien posteriormente se evidencia un trastorno de repolarización precoz tipo 2.It used to be believed that the syndrome of early repolarization, which is determined
by the point J and ST segment on the electrocardiogram, was a benign pattern. In recent decades
its malign character has been shown when presented in the inferior leads and/or side given its
potential to trigger lethal arrhythmias (occurs 1-13% of the general population and in 15-70% of
cases of idiopathic ventricular fibrillation), as in the case of idiopathic polymorphic ventricular
tachycardia that can degenerate into ventricular fibrillation and sudden death. A case of a
41 year-old patient who initially presented episodes of palpitations, syncope and sudden death
is presented, in whom subsequently early repolarization type 2 disorder is evidenced
Image3C, a multimodal image-based and label-independent integrative method for single-cell analysis.
Image-based cell classification has become a common tool to identify phenotypic changes in cell populations. However, this methodology is limited to organisms possessing well-characterized species-specific reagents (e.g., antibodies) that allow cell identification, clustering, and convolutional neural network (CNN) training. In the absence of such reagents, the power of image-based classification has remained mostly off-limits to many research organisms. We have developed an image-based classification methodology we named Image3C (Image-Cytometry Cell Classification) that does not require species-specific reagents nor pre-existing knowledge about the sample. Image3C combines image-based flow cytometry with an unbiased, high-throughput cell clustering pipeline and CNN integration. Image3C exploits intrinsic cellular features and non-species-specific dyes to perform de novo cell composition analysis and detect changes between different conditions. Therefore, Image3C expands the use of image-based analyses of cell population composition to research organisms in which detailed cellular phenotypes are unknown or for which species-specific reagents are not available
Contributions of the classic guitar to the interpretation of the bolero
Uno de los objetivos del estudio de un instrumento musical en instituciones académicas es la formación de instrumentistas solistas. La incorporación de géneros tradicionales en dicha formación conlleva la dificultad de adaptar música originalmente ejecutada en conjuntos instrumentales a un instrumento solista. En este artÃculo se analizan los roles complementarios de las dos guitarras que conforman tradicionalmente el conjunto del bolero y se proponen técnicas instrumentales para que ambas partes puedan ser ejecutadas por una guitarra solista.
Las técnicas propuestas son el toque apoyado, el toque tirado, el pizzicato, los armónicos naturales, la ejecución de melodÃa a dos notas, ligados y apoyaturas, arrastres y uso de barra o ceja. Estas técnicas son aplicadas a seis temas, evaluando en cada caso cuál de ellas se adapta mejor a sus caracterÃsticas musicales. El aporte de esta investigación consiste en la aplicación de técnicas instrumentales de la guitarra clásica solista para la ejecución de boleros, fundamental para la incorporación de dicho género en entornos académicos.One of the objectives of studying a musical instrument in academic institutions is the training of instrumentalists. The incorporation of traditional genres in this level entails the difficulty of adapting music originally performed in instrumental ensembles to a solo instrument. In this article the complementary roles of the two guitars that traditionally make up the bolero ensemble are analyzed to propose instrumental techniques so both parts can be performed by a solo guitar. The proposed techniques are the supported touch, the drawn touch, the pizzicato, the natural harmonics, the execution of a two-note melody, ligatures and supports, dragging and the use of a bar. These techniques are applied to six themes, evaluating in each case which of them best suits their musical characteristics. The contribution of this research consists in the application of instrumental techniques of the classical solo guitar for the performance of boleros, fundamental for the incorporation of this genre in academic settings.Sociedad Argentina para las Ciencias Cognitivas de la Músic
Sarcoma de Kaposi, importancia de su diagnóstico para un correcto tratamiento.
El Sarcoma de Kaposi es una neoplasia vascular poco frecuente, descrita por Moritz Kaposi en 1872.Se desarrolla comúnmente de las células endoteliales con evidencia de origen linfático también. Se han descrito 4 formas:• Clásica.• Endémica.• Asociada a iatrogenia por inmunosupresión.• Asociada a SIDA.Esta última tiene una incidencia de 70% en pacientes VIH+ siendo el paladar duro, la lengua y la encÃa los lugares con más frecuencia de aparición. En el 22% de los casos, la cavidad oral es el lugar de origen de esta lesión, causando movilidad dental, sangrado y dolor
The experience of informal caregivers of children with disabilities: objective and subjective burden - a systematic review
Objective: Describe the experience of informal caregivers of children with disabilities to understand the burden of caregiving. Methods: This article uses the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we defined study inclusion criteria using a PICOS scheme. Essentially, we included only studies that reported data on documents related to caregivers: fathers and mothers of children, adolescents, and adults (P = Population) who diagnosed with any type of disability (I = Intervention), compared to formal caregivers (C = Comparison), and that these parents had the experience of being a caregiver (O = Outcome). In terms of study design, studies with any type of design were included to get a broader view of how existing research has addressed the issue, and a full understanding of the implications of informal caregiving (S = Study Design). The thematic research was carried out in the thesauri of MeSH, my NCBI, PubMed and Scopus. The MeSH terms were used in databases the search was guided by the terms suggested in their Thesaurus tool. Results: The initial search retrieved 136 records. After duplicates were removed (n = 86), the remaining 50 records (titles and abstracts) were screened against our study inclusion criteria, resulting in the exclusion of another 30. Titles not relevant or unrelated to the topic; titles mentioning disability, but not parents; those alluding to formal care; those describing formal medical or nursing care; and those describing nursing caregivers were excluded. Conclusion: A promising avenue for addressing informal caregiving emerges by delving into the need to propose interventions that improve the physical and mental health of caregivers. These interventions should urgently focus on the mental health of mothers, who present greater psychological distress than fathers. It is necessary to propose programs that reveal the need to care for the caregiver, according to the subjective burden (stress); and programs that promote the care of children with disabilities (objective burden), who may be affected by the mental health of their caregiver
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