690 research outputs found

    Espondilodiscitis en la infancia

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    La espondilodiscitis es una enfermedad inflamatoria que afecta el disco intervertebral y los cuerpos vertebrales adyacentes. Esta afección cursa con gran variedad de síntomas, relacionados con la edad del paciente y la localización del proceso inflamatorio. Se presentan 3 casos de discitis en niños pequeños que manifestaron síntomas diversos tales como: dificultad en la marcha, rechazo a caminar o sentarse, lumbalgia y dolor abdominal. Todos presentaron hiperlordosis lumbo-sacra. La centellografía resultó el examen complementario de elección para definir el diagnóstico al demostrar hipercaptación a nivel del disco intervertebral. La antibioticoterapia endovenosa fue curativa. Se propone al dosaje de proteína C reactiva como parámetro de laboratorio útil para el seguimiento.Spondylodiscitis is an inflammatory disease that affects the intervertebral disk and adjacent vertebral bodies. This affection develops a wide variety of symptoms related to the patient´s age and the inflammatory process location. We are reporting three children of early age with discitis who presented a range of symptoms such as: walking difficulties, refusal to walk or sit, low back pain and abdominal pain. Lumbosacral hyperlordosis was present in all cases. Scintigraphy was the complementary method of choice to define the diagnosis by showing hypercaptatation at the invertebral disk level. Endovenous antibiotic therapy proved effective. We propose the dosage of C protein as a useful laboratory parameter for the follow-up of these patients

    Chronic protein restriction in mice impacts placental function and maternal body weight before fetal growth

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    Mechanisms of resource allocation are essential for maternal and fetal survival, particularly when the availability of nutrients is limited. We investigated the responses of feto-placental development to maternal chronic protein malnutrition to test the hypothesis that maternal low protein diet produces differential growth restriction of placental and fetal tissues, and adaptive changes in the placenta that may mitigate impacts on fetal growth. C57BL/6J female mice were fed either a low-protein diet (6% protein) or control isocaloric diet (20% protein). On embryonic days E10.5, 17.5 and 18.5 tissue samples were prepared for morphometric, histological and quantitative RT-PCR analyses, which included markers of trophoblast cell subtypes. Potential endocrine adaptations were assessed by the expression of Prolactin-related hormone genes. In the low protein group, placenta weight was significantly lower at E10.5, followed by reduction of maternal weight at E17.5, while the fetuses became significantly lighter no earlier than at E18.5. Fetal head at E18.5 in the low protein group, though smaller than controls, was larger than expected for body size. The relative size and shape of the cranial vault and the flexion of the cranial base was affected by E17.5 and more severely by E18.5. The junctional zone, a placenta layer rich in endocrine and energy storing glycogen cells, was smaller in low protein placentas as well as the expression of Pcdh12, a marker of glycogen trophoblast cells. Placental hormone gene Prl3a1 was altered in response to low protein diet: expression was elevated at E17.5 when fetuses were still growing normally, but dropped sharply by E18.5 in parallel with the slowing of fetal growth. This model suggests that nutrients are preferentially allocated to sustain fetal and brain growth and suggests the placenta as a nutrient sensor in early gestation with a role in mitigating impacts of poor maternal nutrition on fetal growth.Instituto de Genética VeterinariaFacultad de Ciencias Naturales y Muse

    Amnesia of inhibitory avoidance by scopolamine is overcome by previous open-field exposure

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    The muscarinic cholinergic receptor (MAChR) blockade with scopolamine either extended or restricted to the hippocampus, before or after training in inhibitory avoidance (IA) caused anterograde or retrograde amnesia, respectively, in the rat, because there was no long-term memory (LTM) expression. Adult Wistar rats previously exposed to one or two open-field (OF) sessions of 3 min each (habituated), behaved as control animals after a weak though over-threshold training in IA. However, after OF exposure, IA LTM was formed and expressed in spite of an extensive or restricted to the hippocampus MAChR blockade. It was reported that during and after OF exposure and reexposure there was an increase in both hippocampal and cortical ACh release that would contribute to “prime the substrate,” e.g., by lowering the synaptic threshold for plasticity, leading to LTM consolidation. In the frame of the “synaptic tagging and capture” hypothesis, plasticity-related proteins synthesized during/after the previous OF could facilitate synaptic plasticity for IA in the same structure. However, IA anterograde amnesia by hippocampal protein synthesis inhibition with anisomycin was also prevented by two OF exposures, strongly suggesting that there would be alternative interpretations for the role of protein synthesis in memory formation and that another structure could also be involved in this “OF effect.”Fil: Colettis, Natalia Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Snitcofsky, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Kornisiuk, Edgar Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: González, Emilio N.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Quillfeldt, Jorge A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Jerusalinsky, Diana Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentin

    Acidification induces condensation of the adenovirus core

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    The adenovirus (AdV) icosahedral capsid encloses a nucleoprotein core formed by the dsDNA genome bound to numerous copies of virus-encoded, positively charged proteins. For an efficient delivery of its genome, AdV must undergo a cascade of dismantling events from the plasma membrane to the nuclear pore. Throughout this uncoating process, the virion moves across potentially disruptive environments whose influence in particle stability is poorly understood. In this work we analyze the effect of acidic conditions on AdV particles by exploring their mechanical properties, genome accessibility and capsid disruption. Our results show that under short term acidification the AdV virion becomes softer and its genome less accessible to an intercalating dye, even in the presence of capsid openings. The AFM tip penetrates deeper in virions at neutral pH, and mechanical properties of genome-less particles are not altered upon acidification. Altogether, these results indicate that the main effect of acidification is the compaction of the nucleoproteic core, revealing a previously unknown role for chemical cues in AdV uncoating. Statement of significance: Studying the behavior of virus particles under changing environmental conditions is key to understand cell entry and propagation. One such change is the acidification undergone in certain cell compartments, which is thought to play a role in the programmed uncoating of virus genomes. Mild acidification in the early endosome has been proposed as a trigger signal for human AdV uncoating. However, the actual effect of low pH in AdV stability and entry is not well defined. Understanding the consequences of acidification in AdV structure and stability is also relevant to define storage conditions for therapeutic vectors, or design AdV variants resistant to intestinal conditions for oral administration of vaccinesWe thank M. G. Mateu (CBMSO-CSIC-UAM) for careful reading and insightful comments on early drafts, M. Castellanos and L. A. Campos (CNB-CSIC) for advice with fluorescence measurements and analyses, and M.I. Laguna (CNB-CSIC) for expert technical help. This work was supported by grants from the Spanish Ministry of Economy, Industry and Competitiveness (FIS2017- 89549- R; “Maria de Maeztu” Program for Units of Excellence in R&D MDM-2014-0377; and FIS2017-90701-REDT) and from the Human Frontiers Science Program (HFSPO RGP0012/2018) to P.J.P.; as well as grants PID2019-104098GB-I00/AEI/10.13039/501100011033 and BFU2016-74868-P, co-funded by the Spanish State Research Agency and the European Regional Development Fund, and 2019AEP045 from the Agencia Estatal CSIC to C.S.M. The CNB-CSIC is further supported by a Severo Ochoa Excellence grant (SEV 2017-0712). MM was funded by grant RTI2018-099985-B-I00, (MICINN/FEDER, UE) and the Ciber of Respiratory Diseases (CIBERES), an initiative from the Spanish Institute of Health Carlos III (ISCIII). M.H.-P. was a recipient of a Juan de la Cierva Incorporation postdoctoral contract funded by the Spanish State Research Agency. M.P.-I. held a predoctoral contract from La Caixa Foundation (ID 100010434, under agreement LCF/BQ/SO16/52270032). J. G. is a re cipient of a FPI predoctoral contract (BES-2017-079868) funded by the Spanish State Research Agenc

    History of optics: a modern teaching tool

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    The history of optics is a very rich field of science and it is possible to find many simple and significant examples of the application and success of the experimental method and therefore is a very good tool to transmit to the student the way science proceeds and to introduce the right spirit of critical analysis, building and testing of models, etc. Optical phenomena are specially well suited for this because in fact optical observations and experiments have made science advance in a crucial way in many different periods of history, because they are in many cases quite visual, quite simple in concept and it is very easy to produce experimental setups in classrooms. Also, the intrinsic multidisciplinary character of Optics, which is a subject that has historically influenced in a notorious way fields as art, philosophy, religion and cultural and social studies in general, provide a very wide frame that permits to apply these examples to many different auditories. We present here some reflections about the role that history of optics can play in teaching and show some real examples of its application during the many years that we have been employing it in the context of the Optics School of the Complutense University of Madrid, Spain

    Clinical implications of changing thyroglobulin and antithyroglobulin antibodies analytical methods in the follow-up of patients with differentiated thyroid carcinoma

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    Background and aims: Patients’ response to treatment in differentiated thyroid cancer (DTC) is classified according to serum thyroglobulin concentrations (Tg), usually using the American Thyroid Association guidelines and considering potential interfering anti-thyroglobulin antibodies (Ab-Tg). We aim to evaluate the clinical implications of changing Tg and Ab-Tg quantification method. Material and methods: Tg and Ab-Tg were quantified in 82 serum samples (60 from DTC patients) by Elecsys and Access immunoassays. Results: Elecsys immunoassay rendered higher values of Tg than Access: mean bias 5.03 ng/mL (95%CI:- 14.14–24.21). In DTC patients, there was an almost perfect agreement for response classification (kappa index = 0.833). Discrepancies appeared in patients with undetermined response, with a more tendency to subclassification with Access. Ab-Tg showed a poor correlation (r = 0.5394). When Elecsys cut-off was reduced to 43 IU/ mL, agreement for positive/negative classification improved from a kappa index of 0.607 to 0.650. Prospective study with personalized follow-up showed that only 6.3% of Tg results required an analytical confirmation, being confirmed 93% of them. Conclusions: Despite the biases observed, clinical impact of an analytical change is minimal in patients’ management. However, cautious and personalized follow-up period after the change is still mandatory, especially in patients with Tg levels between 0.2 and 1 ng/mL

    Variability in sediment particle size, mineralogy, and Fe mode of occurrence across dust-source inland drainage basins:the case of the lower Drâa Valley, Morocco

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    The effects of desert dust upon climate and ecosystems depend strongly on its particle size and size-resolved mineralogical composition. However, there is very limited quantitative knowledge on the particle size and composition of the parent sediments along with their variability within dust-source regions, particularly in dust emission hotspots. The lower Drâa Valley, an inland drainage basin and dust hotspot region located in the Moroccan Sahara, was chosen for a comprehensive analysis of sediment particle size and mineralogy. Different sediment type samples (n=42) were collected, including paleo-sediments, paved surfaces, crusts, and dunes, and analysed for particle-size distribution (minimally and fully dispersed samples) and mineralogy. Furthermore, Fe sequential wet extraction was carried out to characterise the modes of occurrence of Fe, including Fe in Fe (oxyhydr)oxides, mainly from goethite and hematite, which are key to dust radiative effects; the poorly crystalline pool of Fe (readily exchangeable ionic Fe and Fe in nano-Fe oxides), relevant to dust impacts upon ocean biogeochemistry; and structural Fe. Results yield a conceptual model where both particle size and mineralogy are segregated by transport and deposition of sediments during runoff of water across the basin and by the precipitation of salts, which causes a sedimentary fractionation. The proportion of coarser particles enriched in quartz is higher in the highlands, while that of finer particles rich in clay, carbonates, and Fe oxides is higher in the lowland dust emission hotspots. There, when water ponds and evaporates, secondary carbonates and salts precipitate, and the clays are enriched in readily exchangeable ionic Fe, due to sorption of dissolved Fe by illite. The results differ from currently available mineralogical atlases and highlight the need for observationally constrained global high-resolution mineralogical data for mineral-speciated dust modelling. The dataset obtained represents an important resource for future evaluation of surface mineralogy retrievals from spaceborne spectroscopy.</p

    Preconditioning donor with a combination of tacrolimus and rapamacyn to decrease ischaemia-reperfusion injury in a rat syngenic kidney transplantation model

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    Reperfusion injury remains one of the major problems in transplantation. Repair from ischaemic acute renal failure (ARF) involves stimulation of tubular epithelial cell proliferation. The aim of this exploratory study was to evaluate the effects of preconditioning donor animals with rapamycin and tacrolimus to prevent ischaemia–reperfusion (I/R) injury. Twelve hours before nephrectomy, the donor animals received immunosuppressive drugs. The animals were divided into four groups, as follows: group 1 control: no treatment; group 2: rapamycin (2 mg/kg); group 3 FK506 (0, 3 mg/kg); and group 4: FK506 (0, 3 mg/kg) plus rapamycin (2 mg/kg). The left kidney was removed and after 3 h of cold ischaemia, the graft was transplanted. Twenty-four hours after transplant, the kidney was recovered for histological analysis and cytokine expression. Preconditioning treatment with rapamycin or tacrolimus significantly reduced blood urea nitrogen and creatinine compared with control [blood urea nitrogen (BUN): P < 0·001 versus control and creatinine: P < 0·001 versus control]. A further decrease was observed when rapamycin was combined with tacrolimus. Acute tubular necrosis was decreased significantly in donors treated with immunosuppressants compared with the control group (P < 0·001 versus control). Moreover, the number of apoptotic nuclei in the control group was higher compared with the treated groups (P < 0·001 versus control). Surprisingly, only rapamycin preconditioning treatment increased anti-apoptotic Bcl2 levels (P < 0·001). Finally, inflammatory cytokines, such as tumour necrosis factor (TNF)-α and interleukin (IL)-6, showed lower levels in the graft of those animals that had been pretreated with rapamycin or tacrolimus. This exploratory study demonstrates that preconditioning donor animals with rapamycin or tacrolimus improves clinical outcomes and reduce necrosis and apoptosis in kidney I/R injury.Facultad de Ciencias MédicasComisión de Investigaciones Científicas de la provincia de Buenos Aire
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