100 research outputs found
Prenatal Diagnosis Improves the Postnatal Cardiac Function in a Population-Based Cohort of Infants with Hypoplastic Left Heart Syndrome
Background: Prenatal diagnosis of hypoplastic left heart syndrome (HLHS) enables planning of perinatal care and is known to be associated with more stable preoperative hemodynamics. The impact on postnatal myocardial function is poorly known. The aim of this study was to determine the impact of prenatal diagnosis of HLHS on postnatal myocardial function.Methods: A consecutively encountered cohort of 66 infants with HLHS born between 2003 and 2010 in Finland was retrospectively reviewed. Twenty-five infants had prenatal diagnoses. Postnatal global and segmental right ventricular fractional area change, strain rate, and myocardial velocity were analyzed from the apical four-chamber view using Velocity Vector Imaging. Preoperative hemodynamic status and end-organ damagemeasurements were the lowest arterial pH, highest lactate, alanine aminotransferase, and creatinine. Early mortality was studied until 30 days after Norwood procedure.Results: Prenatally diagnosed infants had better cardiac function (fractional area change, 27.9 ± 7.4% vs 21.1 ± 6.3%, P = .0004; strain rate, 1.1 ± 0.6/1.3 ± 1.0 vs 0.7 ± 0.2/0.7 ± 0.3 1/sec, P = .004/.003; myocardial velocity, 1.6 ± 0.6/2.0 ± 1.1 vs 1.3 ± 0.4/1.4 ± 0.4 cm/sec, P = .0035/.0009). Mechanical dyssynchrony was similar in both groups (P > .30). Infants diagnosed prenatally had less acidosis (pH = 7.30 vs 7.25, P = .005) and end-organ dysfunction (alanine aminotransferase, 33 ± 38 vs 139 ± 174 U/L, P = .0001;creatinine, 78 ± 18 vs 81 ± 44 mmol/L, P = .05). No deaths occurred among the prenatally diagnosed infants, but four deaths were recorded among postnatally diagnosed infants (P = .15).Conclusions: A prenatal diagnosis of HLHS is associated with improved postnatal right ventricular function, reduced metabolic acidosis, and end-organ dysfunction. (J Am Soc Echocardiogr 2013;26:1073-9.)Keywords: Hypoplastic left heart syndrome, Prenatal diagnosis, Cardiac function, Velocity Vector Imaging<br /
The Wiring Economy Principle: Connectivity Determines Anatomy in the Human Brain
Minimization of the wiring cost of white matter fibers in the human brain appears to be an organizational principle. We investigate this aspect in the human brain using whole brain connectivity networks extracted from high resolution diffusion MRI data of 14 normal volunteers. We specifically address the question of whether brain anatomy determines its connectivity or vice versa. Unlike previous studies we use weighted networks, where connections between cortical nodes are real-valued rather than binary off-on connections. In one set of analyses we found that the connectivity structure of the brain has near optimal wiring cost compared to random networks with the same number of edges, degree distribution and edge weight distribution. A specifically designed minimization routine could not find cheaper wiring without significantly degrading network performance. In another set of analyses we kept the observed brain network topology and connectivity but allowed nodes to freely move on a 3D manifold topologically identical to the brain. An efficient minimization routine was written to find the lowest wiring cost configuration. We found that beginning from any random configuration, the nodes invariably arrange themselves in a configuration with a striking resemblance to the brain. This confirms the widely held but poorly tested claim that wiring economy is a driving principle of the brain. Intriguingly, our results also suggest that the brain mainly optimizes for the most desirable network connectivity, and the observed brain anatomy is merely a result of this optimization
An exceptionally well-preserved skeleton of Palaeothentes from the Early Miocene of Patagonia, Argentina: new insights into the anatomy of extinct paucituberculatan marsupials
International audienc
The Bicoid Stability Factor Controls Polyadenylation and Expression of Specific Mitochondrial mRNAs in Drosophila melanogaster
The bicoid stability factor (BSF) of Drosophila melanogaster has been reported to be present in the cytoplasm, where it stabilizes the maternally contributed bicoid mRNA and binds mRNAs expressed from early zygotic genes. BSF may also have other roles, as it is ubiquitously expressed and essential for survival of adult flies. We have performed immunofluorescence and cell fractionation analyses and show here that BSF is mainly a mitochondrial protein. We studied two independent RNAi knockdown fly lines and report that reduced BSF protein levels lead to a severe respiratory deficiency and delayed development at the late larvae stage. Ubiquitous knockdown of BSF results in a severe reduction of the polyadenylation tail lengths of specific mitochondrial mRNAs, accompanied by an enrichment of unprocessed polycistronic RNA intermediates. Furthermore, we observed a significant reduction in mRNA steady state levels, despite increased de novo transcription. Surprisingly, mitochondrial de novo translation is increased and abnormal mitochondrial translation products are present in knockdown flies, suggesting that BSF also has a role in coordinating the mitochondrial translation in addition to its role in mRNA maturation and stability. We thus report a novel function of BSF in flies and demonstrate that it has an important intra-mitochondrial role, which is essential for maintaining mtDNA gene expression and oxidative phosphorylation
The Intrinsic Antiviral Defense to Incoming HSV-1 Genomes Includes Specific DNA Repair Proteins and Is Counteracted by the Viral Protein ICP0
Cellular restriction factors responding to herpesvirus infection include the ND10 components PML, Sp100 and hDaxx. During the initial stages of HSV-1 infection, novel sub-nuclear structures containing these ND10 proteins form in association with incoming viral genomes. We report that several cellular DNA damage response proteins also relocate to sites associated with incoming viral genomes where they contribute to the cellular front line defense. We show that recruitment of DNA repair proteins to these sites is independent of ND10 components, and instead is coordinated by the cellular ubiquitin ligases RNF8 and RNF168. The viral protein ICP0 targets RNF8 and RNF168 for degradation, thereby preventing the deposition of repressive ubiquitin marks and counteracting this repair protein recruitment. This study highlights important parallels between recognition of cellular DNA damage and recognition of viral genomes, and adds RNF8 and RNF168 to the list of factors contributing to the intrinsic antiviral defense against herpesvirus infection
Revisiting HIV-1 uncoating
HIV uncoating is defined as the loss of viral capsid that occurs within the cytoplasm of infected cells before entry of the viral genome into the nucleus. It is an obligatory step of HIV-1 early infection and accompanies the transition between reverse transcription complexes (RTCs), in which reverse transcription occurs, and pre-integration complexes (PICs), which are competent to integrate into the host genome. The study of the nature and timing of HIV-1 uncoating has been paved with difficulties, particularly as a result of the vulnerability of the capsid assembly to experimental manipulation. Nevertheless, recent studies of capsid structure, retroviral restriction and mechanisms of nuclear import, as well as the recent expansion of technical advances in genome-wide studies and cell imagery approaches, have substantially changed our understanding of HIV uncoating. Although early work suggested that uncoating occurs immediately following viral entry in the cell, thus attributing a trivial role for the capsid in infected cells, recent data suggest that uncoating occurs several hours later and that capsid has an all-important role in the cell that it infects: for transport towards the nucleus, reverse transcription and nuclear import. Knowing that uncoating occurs at a later stage suggests that the viral capsid interacts extensively with the cytoskeleton and other cytoplasmic components during its transport to the nucleus, which leads to a considerable reassessment of our efforts to identify potential therapeutic targets for HIV therapy. This review discusses our current understanding of HIV uncoating, the functional interplay between infectivity and timely uncoating, as well as exposing the appropriate methods to study uncoating and addressing the many questions that remain unanswered
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