RESUMEN
Darwin's theory of evolution, which is based on variation, heredity, and selection, includes all biological fields and spreads to other areas such as philosophy. Medicine is an example of how the evolutionary perspective can greatly improve the understanding of concepts in an area, as human health and pathological conditions are under the effect of evolution. Evolutionary medicine is an emerging paradigm for understanding human heterogeneity, health, and diseases. Nevertheless, there are indications that medical research and practice are only marginally affected by these ideas. Here, we investigate how concepts of biological evolution are employed in medical research. We use a bibliometric approach to look for the presence and frequency of biological evolution-related concepts in medical articles. The distribution of these concepts over the years is analyzed according to the medical specialty and the impact of the journal. Our data showed that: i) only a small percentage of articles in medical journals have an evolutionary perspective; ii) medical journals where these evolution-based articles are published focus on basic science, theoretical medicine, and less frequently, on applied medicine; iii) these articles are mostly from the microbiology, immunology, neurology, psychology, behavior, and oncology fields; and iv) viruses are the most frequently covered microorganisms, followed by bacteria, fungi, and protozoans. The collection of our results, considering the importance of evolutionary medicine in the medical field, highlights the need for a decisive change in perspective in medical research.
Asunto(s)
Evolución Biológica , Medicina , Humanos , BiologíaRESUMEN
Darwin's theory of evolution, which is based on variation, heredity, and selection, includes all biological fields and spreads to other areas such as philosophy. Medicine is an example of how the evolutionary perspective can greatly improve the understanding of concepts in an area, as human health and pathological conditions are under the effect of evolution. Evolutionary medicine is an emerging paradigm for understanding human heterogeneity, health, and diseases. Nevertheless, there are indications that medical research and practice are only marginally affected by these ideas. Here, we investigate how concepts of biological evolution are employed in medical research. We use a bibliometric approach to look for the presence and frequency of biological evolution-related concepts in medical articles. The distribution of these concepts over the years is analyzed according to the medical specialty and the impact of the journal. Our data showed that: i) only a small percentage of articles in medical journals have an evolutionary perspective; ii) medical journals where these evolution-based articles are published focus on basic science, theoretical medicine, and less frequently, on applied medicine; iii) these articles are mostly from the microbiology, immunology, neurology, psychology, behavior, and oncology fields; and iv) viruses are the most frequently covered microorganisms, followed by bacteria, fungi, and protozoans. The collection of our results, considering the importance of evolutionary medicine in the medical field, highlights the need for a decisive change in perspective in medical research.
RESUMEN
The effect of selection for postweaning weight was evaluated within the growth curve parameters for both growth and carcass traits. Records of 2404 Nellore animals from three selection lines were analyzed: two selection lines for high postweaning weight, selection (NeS) and traditional (NeT); and a control line (NeC) in which animals were selected for postweaning weight close to the average. Body weight (BW), hip height (HH), rib eye area (REA), back fat thickness (BFT), and rump fat thickness (RFT) were measured and records collected from animals 8 to 20 (males) and 11 to 26 (females) months of age. The parameters A (asymptotic value) and k (growth rate) were estimated using the nonlinear model procedure of the Statistical Analysis System program, which included fixed effect of line (NeS, NeT, and NeC) in the model, with the objective to evaluate differences in the estimated parameters between lines. Selected animals (NeS and NeT) showed higher growth rates than control line animals (NeC) for all traits. Line effect on curves parameters was significant (P < 0.001) for BW, HH, and REA in males, and for BFT and RFT in females. Selection for postweaning weight was effective in altering growth curves, resulting in animals with higher growth potential.
Asunto(s)
Bovinos/crecimiento & desarrollo , Ultrasonografía/veterinaria , Animales , Peso Corporal , Pesos y Medidas Corporales/métodos , Pesos y Medidas Corporales/veterinaria , Cruzamiento/métodos , Bovinos/genética , Femenino , Masculino , Dinámicas no Lineales , Fenotipo , Selección Genética , Ultrasonografía/métodosRESUMEN
Porifera [sponges] represent the lowest metazoan phylum, probably already existing prior to the 'Cambrian explosion'. Based on amino acid sequences deduced from cDNAs that code for structural proteins, the monophyly of Metazoa was established. Now we analyzed for the first time a promoter of a sponge gene for its activity in a heterologous cell system from higher Metazoa. The promoter of the homeobox gene EmH-3 was cloned and sequenced from a genomic library of the freshwater sponge Ephydatia muelleri. For the determination of functional promoter activity, transient transfection experiments in mouse NIH 3T3 cells were performed; the promoter was fused with the luciferase reporter gene. The data revealed that a 401 nt long promoter fragment, comprising several binding elements for metazoan transcription factors, showed the highest activity, while the 175 bp long promoter segment, comprising solely the TATA- and Cap boxes, showed only 25% of that activity. This result demonstrates that the sponge promoter is activated by factors present in mammalian cells and supports the view that Porifera, together with the other metazoan phyla, are of monophyletic origin.
Asunto(s)
Genes Homeobox , Proteínas de Homeodominio/genética , Poríferos/genética , Regiones Promotoras Genéticas , Células 3T3 , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario , Proteínas de Homeodominio/química , Ratones , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido NucleicoRESUMEN
Trehalase activity decreased in 95% at the onset of the transition phase of growth of S. cerevisiae. The question which we raised was whether this phenomenon was due to proteolysis or to conversion of the enzyme to a less active form (dephosphorylation). Immunological methods allowed to identify the presence of the trehalase protein during cell growth. At the same stage of growth, an increase in the non-phosphorylated enzyme was detected "in vitro". Results utilizing mutant strains also indicated that regulation occurred by interconversion of forms. The same mechanism also seems to control trehalase activity in non proliferating conditions.