263 research outputs found
Clasificación de las ictericias
Clasificar las ictericias fue siempre objeto de desvelo por parte de los internistas y patólogos. Todas las clasificaciones conocidas, hasta hace algunos años, siempre adolecieron de defectos, al mezclar conceptos clínicos, etiológicos, patogénicos, etc.
En los últimos años, la adquisición de nuevos conocimientos en el campo del metabolismo de la bilirrubina, desde su origen en la hemoglobina procedente de la hemolisis, hasta su constitución final, tal como aparece en la bilis, ha llenado varios puntos oscuros, verdaderos baches en el conocimiento, desde la interpretación de la reacción de Imas-Van der Berg, hasta los modernos descubrimientos sobre el metabolismo intracelular de la bilirrubina por Colé y Lathe. También han contribuido grandemente la aplicación del microscopio electrónico a los estudios clínicos y experimentales.
Todo esto hace necesario que, para poder efectuar una clasificación acorde con los conocimientos actuales, hagamos una somera revisión sobre el metabolismo de la bilirrubina y que con el auxilio de los conocimientos que nos brinda la anatomía patológica, intentemos clasificar las ictericias desde un punto de vista topográfico y fisiopatológico, sin desconocer que no será perfecta ni completa, pero sí ajustada a una realidad presente, susceptible de modificarse y mejorarse en un futuro cercano, al ritmo de los nuevos y vertiginosos avances en el conocimiento, y efectuar entonces una más completa y mejor clasificación.Facultad de Ciencias Médica
Clasificación de las ictericias
Clasificar las ictericias fue siempre objeto de desvelo por parte de los internistas y patólogos. Todas las clasificaciones conocidas, hasta hace algunos años, siempre adolecieron de defectos, al mezclar conceptos clínicos, etiológicos, patogénicos, etc.
En los últimos años, la adquisición de nuevos conocimientos en el campo del metabolismo de la bilirrubina, desde su origen en la hemoglobina procedente de la hemolisis, hasta su constitución final, tal como aparece en la bilis, ha llenado varios puntos oscuros, verdaderos baches en el conocimiento, desde la interpretación de la reacción de Imas-Van der Berg, hasta los modernos descubrimientos sobre el metabolismo intracelular de la bilirrubina por Colé y Lathe. También han contribuido grandemente la aplicación del microscopio electrónico a los estudios clínicos y experimentales.
Todo esto hace necesario que, para poder efectuar una clasificación acorde con los conocimientos actuales, hagamos una somera revisión sobre el metabolismo de la bilirrubina y que con el auxilio de los conocimientos que nos brinda la anatomía patológica, intentemos clasificar las ictericias desde un punto de vista topográfico y fisiopatológico, sin desconocer que no será perfecta ni completa, pero sí ajustada a una realidad presente, susceptible de modificarse y mejorarse en un futuro cercano, al ritmo de los nuevos y vertiginosos avances en el conocimiento, y efectuar entonces una más completa y mejor clasificación.Facultad de Ciencias Médica
Clasificación de las ictericias
Clasificar las ictericias fue siempre objeto de desvelo por parte de los internistas y patólogos. Todas las clasificaciones conocidas, hasta hace algunos años, siempre adolecieron de defectos, al mezclar conceptos clínicos, etiológicos, patogénicos, etc.
En los últimos años, la adquisición de nuevos conocimientos en el campo del metabolismo de la bilirrubina, desde su origen en la hemoglobina procedente de la hemolisis, hasta su constitución final, tal como aparece en la bilis, ha llenado varios puntos oscuros, verdaderos baches en el conocimiento, desde la interpretación de la reacción de Imas-Van der Berg, hasta los modernos descubrimientos sobre el metabolismo intracelular de la bilirrubina por Colé y Lathe. También han contribuido grandemente la aplicación del microscopio electrónico a los estudios clínicos y experimentales.
Todo esto hace necesario que, para poder efectuar una clasificación acorde con los conocimientos actuales, hagamos una somera revisión sobre el metabolismo de la bilirrubina y que con el auxilio de los conocimientos que nos brinda la anatomía patológica, intentemos clasificar las ictericias desde un punto de vista topográfico y fisiopatológico, sin desconocer que no será perfecta ni completa, pero sí ajustada a una realidad presente, susceptible de modificarse y mejorarse en un futuro cercano, al ritmo de los nuevos y vertiginosos avances en el conocimiento, y efectuar entonces una más completa y mejor clasificación.Facultad de Ciencias Médica
Mitogenome and Nuclear-encoded Fungicide-target Genes of Thecaphora frezii - Causal Agent of Peanut Smut
Background: Thecaphora frezii Carranza and Lindquist causes smut disease in peanut (Arachis hypogaea L.) resulting in up to 35% yield losses. Fungicides have shown ineffective in controlling the disease; whereas research on the molecular basis of that fungicide resistance has been hindered because of the lack of genetic information about T. frezii. The goal of this work was to provide molecular information about fungicide-target loci in T. frezii, including its mitochondrial genome (mitogenome) and critical nuclear-encoded genes.
Results: Here we report the complete annotated mitogenome of T. frezii, a 123,773 bp molecule containing the standard 14 genes that form part of mitochondrial complexes I, III, IV and V, 22 transfer RNAs, small and large subunits of ribosomal RNA, DNA polymerase, ribonuclease P, GII-reverse transcriptase/maturase, nine hypothetical open-reading frames and homing endonucleases (LAGLIDADG, GIY-YIG, HEG). In addition, we report the full-length cDNA sequence of T. frezii cytochrome b (cob) and cytochrome oxidase 1 (cox1) genes; as well as partial sequences of T. frezii succinate dehydrogenase (sdhb), ergosterol biosynthesis (Erg4), cytochrome P450 (cyp51), and beta tubulin (β-tubulin) genes, which are respective targets of strobilurins, quinone oxidation inhibitors, triazoles and beta-tubulin inhibitor fungicides commonly used in the peanut crop. Translation of cob and sdhb genes in this particular T. frezii isolate suggests potential resistance to strobilurin and carboxamide fungicides.
Conclusion: The mitogenome and nuclear-encoded gene sequences presented here provide the molecular tools to research T. frezii fungicide-target loci
Nuevas estrellas pre enanas blancas pulsantes de masa extremadamente baja descubiertas en el CASLEO
The Extremely Low Mass white dwarfs (ELM, M 0.18--0.20 M) could arise after the loss of large amount of mass suffered by a red giant star in a binary system. The low mass white dwarfs have become an important source of study because some of them are pulsating stars. The latter is an unprecedented opportunity to know their interior and the evolutionary channels leading to their origin, by employing asteroseismology. In this paper, we present photometric analysis of data obtained in the CASLEO (Complejo Astronómico El Leoncito) about four new pulsating stars, that according to their surface gravities and effective temperatures, would be pre-ELM white dwarf stars. With this discovery, the number of pulsating pre-ELM white dwarf stars known would increase to six members.Fil: Corti, Mariela Alejandra. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; ArgentinaFil: Kanaan, Antonio. Universidade Federal de Santa Catarina; BrasilFil: Corsico, Alejandro Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Kepler, S. O.. Universidade Federal do Rio Grande do Sul; BrasilFil: Althaus, Leandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; ArgentinaFil: Koester, D.. Universität Kiel; AlemaniaFil: Sánchez Arias, Julieta Paz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; Argentin
Two new pulsating low-mass pre-white dwarfs or SX Phoenicis stars?
Context. The discovery of pulsations in low-mass stars opens an opportunity to probe their interiors and determine their evolution by employing the tools of asteroseismology. Aims. We aim to analyse high-speed photometry of SDSS J145847.02+070754.46 and SDSS J173001.94+070600.25 and discover brightness variabilities. In order to locate these stars in the Teff - log g diagram, we fit optical spectra (SDSS) with synthetic non-magnetic spectra derived from model atmospheres. Methods. To carry out this study, we used the photometric data we obtained for these stars with the 2.15 m telescope at CASLEO, Argentina. We analysed their light curves and applied the discrete Fourier transform (FT) to determine the pulsation frequencies. Finally, we compare both stars in the Teff - log g diagram, with two known pre-white dwarfs and seven pulsating pre-ELM white dwarf stars, δ Scuti, and SX Phe stars Results. We report the discovery of pulsations in SDSS J145847.02+070754.46 and SDSS J173001.94+070600.25. We determine their effective temperature and surface gravity to be Teff = 7972 ± 200 K, log g = 4.25 ± 0.5 and Teff = 7925 ± 200 K, log g = 4.25 ± 0.5, respectively. With these parameters, these new pulsating low-mass stars can be identified with either ELM white dwarfs (with ∼0.17 MO) or more massive SX Phe stars. We identified pulsation periods of 3278.7 and 1633.9 s for SDSS J145847.02+070754.46 and a pulsation period of 3367.1 s for SDSS J173001.94+070600.25. These two new objects, together with those of Maxted et al. (2013, 2014), indicate the possible existence of a new instability domain towards the late stages of evolution of low-mass white dwarf stars, although their identification with SX Phe stars cannot be discarded.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí
Ab initio and finite-temperature molecular dynamics studies of lattice resistance in tantalum
This manuscript explores the apparent discrepancy between experimental data
and theoretical calculations of the lattice resistance of bcc tantalum. We
present the first results for the temperature dependence of the Peierls stress
in this system and the first ab initio calculation of the zero-temperature
Peierls stress to employ periodic boundary conditions, which are those best
suited to the study of metallic systems at the electron-structure level. Our ab
initio value for the Peierls stress is over five times larger than current
extrapolations of experimental lattice resistance to zero-temperature. Although
we do find that the common techniques for such extrapolation indeed tend to
underestimate the zero-temperature limit, the amount of the underestimation
which we observe is only 10-20%, leaving open the possibility that mechanisms
other than the simple Peierls stress are important in controlling the process
of low temperature slip.Comment: 12 pages and 9 figure
Low-grade inflammation as mediator between diet and behavioral disinhibition:A UK Biobank study
BACKGROUND: Dietary patterns have been associated with variations in behavior. However, evidence has been limited and mixed, and the underlying mechanism remains unclear. OBJECTIVE: Extend a previous study reporting significant associations between food patterns and behavioral disinhibition and explore whether low-grade inflammation is linked to behaviors and mediates the association between diet and behavioral disinhibition. DESIGN: Among participants of the UK Biobank (UKB) we extracted a single behavioral disinhibition principal component using the UKB touchscreen questionnaire, Mental Health Questionnaire (MHQ), and registered diagnoses. We identified four dietary patterns (prudent diet, elimination of wheat/dairy/eggs, meat-based diet, full-cream dairy consumption) by using the Food Frequency Questionnaire (FFQ). Immune biomarkers and an aggregated inflammation score (INFLA-score) were used to characterize low-grade inflammation. Associations between dietary patterns and immune biomarkers, between immune biomarkers and disinhibition were assessed, with adjustment for demographics, lifestyle factors, and somatic health conditions. Next, mediation analyses were run to examine whether the association between dietary patterns and disinhibition was partially explained by inflammatory levels. We also conducted subgroup analyses to explore whether associations and the mediation effect differed by sex, age, ethnicity/race, body-mass-index (BMI), and socioeconomic status (SES). RESULTS: The prudent diet was negatively, and the meat-based diet was positively associated with several pro-inflammatory biomarkers. Most immune biomarkers were positively associated with disinhibition (numbers of lymphocytes (βstandardized = 0.082, p < 0.001), monocytes (βstandardized = 0.043, p < 0.001), neutrophils (βstandardized = 0.071, p < 0.001), platelets (βstandardized = 0.022, p < 0.001), leukocytes (βstandardized = 0.093, p < 0.001), C-reactive protein (βstandardized = 0.051, p < 0.001), and for INFLA-score (βstandardized = 0.074, p < 0.001). In the mediation model, the INFLA-score mediated the association between prudent diet and meat-based diet and disinhibition score, with a significant indirect effect of low-grade inflammation for the prudent diet-disinhibition association (βstandardized = -0.007, p < 0.001) and for meat-disinhibition association (βstandardized = 0.001, p < 0.001)). Although all effects were small, covariates and interaction term adjustments did not attenuate the effects, and neither did most subgroup-only analyses. CONCLUSIONS: The prudent diet was associated with a lower disinhibition score and this effect was partially mediated by the lower inflammation. Reversely, the meat-based diet was linked to more inflammation, which was associated with more disinhibition. Our findings suggest mediating effects of immune function in the relationship between diet and behavioral disinhibition. However further alternative designs such as interventional trials are needed to establish causal effects
Developmentally Sensitive Interaction Effects of Genes and the Social Environment on Total and Subcortical Brain Volumes
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167721.PDF (publisher's version ) (Open Access)Smaller total brain and subcortical volumes have been linked to psychopathology including attention-deficit/hyperactivity disorder (ADHD). Identifying mechanisms underlying these alterations, therefore, is of great importance. We investigated the role of gene-environment interactions (GxE) in interindividual variability of total gray matter (GM), caudate, and putamen volumes. Brain volumes were derived from structural magnetic resonance imaging scans in participants with (N = 312) and without ADHD (N = 437) from N = 402 families (age M = 17.00, SD = 3.60). GxE effects between DAT1, 5-HTT, and DRD4 and social environments (maternal expressed warmth and criticism; positive and deviant peer affiliation) as well as the possible moderating effect of age were examined using linear mixed modeling. We also tested whether findings depended on ADHD severity. Deviant peer affiliation was associated with lower caudate volume. Participants with low deviant peer affiliations had larger total GM volumes with increasing age. Likewise, developmentally sensitive GxE effects were found on total GM and putamen volume. For total GM, differential age effects were found for DAT1 9-repeat and HTTLPR L/L genotypes, depending on the amount of positive peer affiliation. For putamen volume, DRD4 7-repeat carriers and DAT1 10/10 homozygotes showed opposite age relations depending on positive peer affiliation and maternal criticism, respectively. All results were independent of ADHD severity. The presence of differential age-dependent GxE effects might explain the diverse and sometimes opposing results of environmental and genetic effects on brain volumes observed so far
First draft genome of \u3ci\u3eThecaphora frezii\u3c/i\u3e, causal agent of peanut smut disease
Objectives: The fungal pathogen Thecaphora frezii Carranza & Lindquist causes peanut smut, a severe disease currently endemic in Argentina. To study the ecology of T. frezii and to understand the mechanisms of smut resistance in peanut plants, it is crucial to know the genetics of this pathogen. The objective of this work was to isolate the pathogen and generate the first draft genome of T. frezii that will be the basis for analyzing its potential genetic diversity and its interaction with peanut cultivars. Our research group is working to identify peanut germplasm with smut resistance and to understand the genetics of the pathogen. Knowing the genome of T. frezii will help analyze potential variants of this pathogen and contribute to develop enhanced peanut germplasm with broader and long-lasting resistance. Data description: Thecaphora frezii isolate IPAVE 0401 (here referred as T.f.B7) was obtained from a single hyphal-tip culture, its DNA was sequenced using Pacific Biosciences Sequel II (PacBio) and Illumina NovaSeq6000 (Nova). Data from both sequencing platforms were combined and the de novo assembling estimated a 29.3 Mb genome size. Completeness of the genome examined using Benchmarking Universal Single-Copy Orthologs (BUSCO) showed the assembly had 84.6% of the 758 genes in fungi_odb10
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