[Avascular necrosis of the hip secondary to long-standing COVID]. / Necrosis avascular de cadera secundaria a COVID de larga duración.

Long COVID is a term used to describe the long-terms effects of COVID-19 infection that continue for weeks or months after the patient has recovered from COVID-19. Long COVID is defined by the persistence of symptoms beyond 12 weeks from the onset of the disease. Corticosteroids are part of the treatment in this period with good results in controlling the disease; however, it is a predisposing factor for the development of avascular necrosis. We present a clinic case of a young man of 39 years old with diagnosis of avascular necrosis in his left hip, before the administration of corticosteroids for the treatment of COVID-19. There is a lack of consensus about the dosage and duration of steroids required to develop avascular necrosis. Some authors have reported that cumulative dose of 2,000 mg prednisone (or its equivalent) was required for avascular necrosis development. For patients with advanced avascular necrosis stages total hip arthroplasty is an attractive option with excellent outcomes in terms of pain relief and survivorship.

El COVID de larga duración es un término que describe la enfermedad en pacientes que se recuperaron de una infección por COVID-19 y reportan síntomas por más de 12 semanas. Los corticosteroides forman parte del tratamiento en este período con buenos resultados en el control de la enfermedad; sin embargo, el uso de este grupo de medicamentos se ha descrito como un factor de riesgo para el desarrollo de necrosis avascular. Se describe el caso clínico de un paciente masculino de 39 años con diagnóstico de necrosis avascular de la cadera izquierda posterior a la administración de corticosteroides para el tratamiento de COVID-19. La dosis de esteroides capaz de provocar necrosis avascular no está clara o bien descrita; sin embargo, existen reportes en la literatura donde se habla de dosis de 2,000 mg de prednisona (o equivalentes) para su desarrollo. El tratamiento de la necrosis avascular tiene como objetivo el alivio del dolor, retardar la progresión del cuadro, prevenir el colapso en etapas tempranas y restaurar la función articular. La artroplastía o recambio total de cadera parece ser una excelente opción de tratamiento quirúrgico para aquellos pacientes en etapas avanzadas.

Primary and secondary non-traumatic intra-cerebral haemorrhage: MRI findings.

Intracranial haemorrhage (ICH) accounts for 10-30% of strokes, being the form with the worst prognosis. The causes of cerebral haemorrhage can be both primary, mainly hypertensive and amyloid angiopathy, and secondary, such as tumours or vascular lesions. Identifying the aetiology of bleeding is essential since it determines the treatment to be performed and the patient's prognosis. The main objective of this review is to review the main magnetic resonance imaging (MRI) findings of the primary and secondary causes of ICH, focusing on those radiological signs that help guide bleeding due to primary angiopathy or secondary to an underlying lesion. The indications for MRI in the event of non-traumatic intracranial haemorrhage will also be reviewed.

New transgenic models of Parkinson's disease using genome editing technology. / Nuevos modelos transgénicos para el estudio de la enfermedad de Parkinson basados en sistemas de edición con nucleasas.

INTRODUCTION: Parkinson's disease (PD) is the second most common neurodegenerative disorder. It is characterised by selective loss of dopaminergic neurons in the substantia nigra pars compacta, which results in dopamine depletion, leading to a number of motor and non-motor symptoms. DEVELOPMENT: In recent years, the development of new animal models using nuclease-based genome-editing technology (ZFN, TALEN, and CRISPR/Cas9 nucleases) has enabled the introduction of custom-made modifications into the genome to replicate key features of PD, leading to significant advances in our understanding of the pathophysiology of the disease. CONCLUSIONS: We review the most recent studies on this new generation of in vitro and in vivo PD models, which replicate the most relevant symptoms of the disease and enable better understanding of the aetiology and mechanisms of PD. This may be helpful in the future development of effective treatments to halt or slow disease progression.

IgG4-related disease: Is rituximab the best therapeutic strategy for cases refractory to conventional therapy? Results of a systematic review. / Enfermedad relacionada con IgG4: ¿es el rituximab la mejor estrategia terapéutica en los casos refractarios a terapia convencional? Resultados de una revisión sistemática.

INTRODUCTION: IgG4 related disease is a fibroinflammatory condition characterised by lymphoplasmocytic infiltration with predominance of IgG4+ plasma cells, fibrosis, and in most cases elevated IgG4 serum levels. It can affect any organ and result in varying clinical manifestations. Steroids are the cornerstone of treatment, however there is a high percentage of relapse. Recent studies have demonstrated favourable effects with rituximab. OBJECTIVE: To evaluate effectiveness related to the response to treatment with rituximab in patients with IgG4 related disease refractory to steroids and other immunosuppressant therapies. MATERIALS AND METHODS: We undertook a systematic search of the specialist databases EMBASE, LILACS, PUBMED and OVID-Cochrane for publications up until December 2017. RESULTS: After the quality analysis, we selected 27 articles (264 patients in total) for the final review, of which 23 were case reports and case series (105 patients), 3 were observational follow-up cohort studies (129 patients), and there was one clinical trial (30 patients). IgG4 related disease presents predominantly in male patients aged between 50 and 70 years on average. Multiple organs are compromised with an average of 3.5 compromised organs. Orbital, glandular and lymph-node compromise is most frequent. Patients in the different studies we included had received various treatments prior to starting rituximab, including glucocorticoids and disease-modifying anti-rheumatic drugs. There was 90.7% response in the cases where rituximab was used as second line therapy; rituximab was used as first line treatment for 10% of the patients with a 100% response rate. CONCLUSION: The use of rituximab for patients refractory to first-line treatments was associated with a high response percentage and less dependence on glucocorticoids.

Clinical significance of epithelial-mesenchymal transition-related markers expression in the micrometastatic sentinel lymph node of NSCLC.

OBJECTIVES: Metastatic lymph node affectation is the main prognostic factor in localised lung cancer. However, the pathological study of lymph nodes reveals tumour relapse for 20% of patients after oncological curative surgery. Recently, EMT (epithelial-mesenchymal transition) has been established as one of the main factors related to lymphatic dissemination and metastasis. This study evaluated the prognostic value of EMT-related gene expression in micrometastatic sentinel lymph nodes (SLN) of non-small cell lung cancer (NSCLC) patients. METHODS: The presence of genes CDH1, CDH2, VIM, TWIST1, SNAI1, SNAI2, ZEB1, and ZEB2 in mRNA was analysed in tumours and in the SLN of NSCLC patients for whom surgery was planned for treatment. The significant association between the expression level of EMT-related markers and patients' clinicopathological characteristics and relapse was assessed. RESULTS: Of the 96 patients, 56 (58.33%) presented molecular micrometastasis in SLN, which showed higher CDH1, CDH2, and VIM expressions than non-micrometastatic ones. An association linking a low CDH1/CDH2 ratio in SLN with molecular micrometastasis, adenocarcinoma, and non-smoking patients was found. The multivariate Cox regression analysis proved the prognostic accuracy of the CDH1/CDH2 ratio in SLN. CONCLUSIONS: The molecular EMT status of SLN could be used as an independent prognosis predictor in early stage NSLCL patients, and as a new tool to better stratify and predict patient outcomes.

Physicochemical and biological interactions between cerium oxide nanoparticles and a 1,8-naphthalimide derivative.

Cerium (Ce) oxide nanoparticles (CNPs) have attracted attention due to their high bioactivity and unique redox-chemistry. The oxygen vacancies at the surface of the nanoparticle explain the autocatalytic properties of CNPs in which the Ce3+ atoms occupy the center of the oxygen vacancies surrounded by Ce4+ atoms. Until now, CNPs have been associated with organic molecules at the synthesis stage to extend their applications or improve their stability. However, there is a lack of information regarding the post-synthesis interaction of CNPs and organic molecules that could enhance or induce new properties. Due to their unique optical properties and their many uses in different areas such as supramolecular chemistry or biomedicine, we have chosen a derivative from the family of naphthalimides (the 4-amino-1,8-naphthalimide-N-substituted; ANN) to study the interaction with different CNPs (CNP1-4) and their joint bioactivity compared to that of the same compounds alone. ANN-CNP complexes were formed as revealed by spectroscopic studies, but, the interaction was markedly different depending on the physicochemical properties of CNPs and their surface content of Ce3+ sites. The ANN adsorption on all CNPs involved the amino group in the naphthalene moiety as shown by NMR spectroscopy, while the pyrrolidine ring was mainly involved in the specific interaction between ANN and CNP1. The biological effect of each CNP and ANN individually and forming complexes was assessed using a bioluminescent model bacterium. The results showed that ANN and CNP with the higher content of surface Ce3+ (CNP1) when combined acted additively towards the used model organism. In the opposite, ANN-CNP2, ANN-CNP3 and ANN-CNP4 complexes were antagonistic when the nanoparticles dominated the mixture. The results of this study contribute to expand the knowledge of the interaction between nanoparticles and organic molecules which may be useful for understanding the behavior of nanoparticles in complex matrices.

CO2 reduction over NaNbO3 and NaTaO3 perovskite photocatalysts.

The activity of NaNbO3 and NaTaO3 perovskites for the photocatalytic reduction of CO2 is studied in this work. For this purpose, sodium niobate and tantalate have been prepared using solid-state reactions, extensively characterised by means of powder X-ray diffraction, UV-vis, photoluminescence and Raman spectroscopies and N2 adsorption isotherms, and tested in the gas-phase reduction of CO2 under UV light in a continuous flow photoreactor. NaNbO3 is constituted of an orthorhombically distorted perovskite structure, while a ca. 4.5 : 1 combination of the orthorhombic and monoclinic modifications is found in the tantalate. Both catalysts exhibit interesting intrinsic activities, with the tantalate material giving rise to a slightly higher performance. This is attributed to a compromise situation between electron-hole recombination and the reducing potential of conduction band electrons. In addition, a decrease in the competition of water protons for photogenerated electrons is observed with both catalysts with respect to TiO2.

Revisiting the BaO2/BaO redox cycle for solar thermochemical energy storage.

The barium peroxide-based redox cycle was proposed in the late 1970s as a thermochemical energy storage system. Since then, very little attention has been paid to such redox couples. In this paper, we have revisited the use of reduction-oxidation reactions of the BaO2/BaO system for thermochemical heat storage at high temperatures. Using thermogravimetric analysis, reduction and oxidation reactions were studied in order to find the main limitations associated with each process. Furthermore, the system was evaluated through several charge-discharge stages in order to analyse its possible degradation after repeated cycling. Through differential scanning calorimetry the heat stored and released were also determined. Oxidation reaction, which was found to be slower than reduction, was studied in more detail using isothermal tests. It was observed that the rate-controlling step of BaO oxidation follows zero-order kinetics, although at high temperatures a deviation from Arrhenius behaviour was observed probably due to hindrances to anionic oxygen diffusion caused by the formation of an external layer of BaO2. This redox couple was able to withstand several redox cycles without deactivation, showing reaction conversions close to 100% provided that impurities are previously eliminated through thermal pre-treatment, demonstrating the feasibility of this system for solar thermochemical heat storage.

Pulse-width modulated external resistance increases the microbial fuel cell power output.

This study describes MFC operation with a pulse-width modulated connection of the external resistor (R-PWM mode) at low and high frequencies. Analysis of the output voltage profiles acquired during R-PWM tests showed the presence of slow and fast dynamic components, which can be described by a simple equivalent circuit model suitable for process control applications. At operating frequencies above 100 Hz a noticeable improvement in MFC performance was observed with the power output increase of 22-43% as compared to MFC operation with a constant external resistance.

Revisiting the hydrothermal synthesis of titanate nanotubes: new insights on the key factors affecting the morphology.

Recently, titanate nanotubes have attracted a significant deal of interest, but the mechanism of formation as well as some structural aspects of these materials is still under debate. In this context, the main goal of the present study is to identify the key factors affecting the morphology of the titanate nanostructures during hydrothermal synthesis in order to increase the homogeneity and control, as finely as possible, the dimensions of the nanotubes. Previous studies also analyzed the influence of synthesis conditions but, unlike other works, the simultaneous assessment of the influence of parameters such as the phase and crystal size of the TiO(2) used as precursor, and the time and temperature of the hydrothermal treatment has been now analyzed under the same experimental context. The characterization of the prepared materials by means of TEM, XRD, N(2) adsorption isotherms and Raman spectroscopy was performed to establish correlations between the structural features and the preparation conditions. In this research, special attention has been paid to study the non-washed materials, which most of the previous studies have excluded from characterization. After hydrothermal treatment amorphous particles with different morphologies are isolated before acidification, which seems to be a crucial stage in controlling nanotube formation. Besides, the obtained data indicate that some characteristics of the nanotubes, such as the degree of conversion, the homogeneity and crystallinity of the structures or the aspect ratio, can be easily selected by adjusting the synthesis parameters.

Morfometría de los ramos nerviosos para los músculos interóseos plantares del pie en el hombre / Morphometry of nerve branches for plantar interossei muscles in the foot of man

La inervación del pie ha requerido especial atención por su utilidad en el abordaje clínico y quirúrgico de patologías y síndromes dolorosos como talalgias, fascitis plantar y fibromatosis plantar, entre otras. Estudios realizados, han permitido conocer la importancia funcional de los músculos interóseos plantares. Sin embargo, no se conoce mayores detalles de su inervación. Realizamos un estudio morfométrico en 5 muestras de ramos nerviosos para el primer, segundo y tercer músculo interóseo en cadáveres de individuos adultos, masculinos. Se obtuvieron secciones transversales de cada uno de los nervios después de su origen, a nivel del plano profundo de la región plantar del pie. Realizamos cortes de 4 um de grosor los cuales fueron teñidos con Hematoxilina-Eosina (H.E.). El promedio de fascículos en el ramo para el primer músculo interóseo (R1 IOP) fue 1 (D.E. 0,00); para el segundo músculo interóseo (R2 IOP) fue 2 (D.E. 0,45) y para el tercer músculo interóseo (R3 IOP) fue 2 (D.E. 1,00). El promedio de fibras para el R1 IOP, R2 IOP Y R3 IOP fue: 547 (D.E. 153), 644 (D.E. 258) y 1.161 (D.E. 465) respectivamente. El área promedio del R1 IOP, R2 IOP Y R3 IOP fue: 0,06 mm2 (D. E. 0,02), 0,08 mm2 (D. E. 0,03), 0,14 mm2 (D. E. 0,06), respectivamente. El estudio morfométrico y estereológico de estos ramos nerviosos espera aportar al conocimiento de los profesionales que deben intervenir clínica y quirúrgicamente en la región plantar del pie.

Innervation of the foot has required special attention in view of its use in clinical and surgical treatment of painful diseases and syndromes such as talalgia, plantar fasciitis and plantar fibromatosis are among those mentioned. Studies realized have made possible the functional significance of plantar interossei muscles. However, there is no information regarding greater detail of their innervation. A morphometric study was carried out in 5 nerve branches for the first, second and third plantar interossei muscles in cadavers of adult male individuals. Cross sections were obtained of each one of the nerves after their origin, at the deep level of the plantar region of the foot. Cuts of 4 um thick were realized which were stained with Hematoxylin-Eosin (H.E.). Average fascicles in the branch for the first interosseous muscle(R1 IOP) was 1 (D.E. 0,00); for the second interosseous muscle(R2 IOP) was 2 (D.E. 0.45); and for the third interosseous muscle(R3 IOP) was 2 (D.E. 1.00). The average of fibers for thel R1 IOP, R2 IOP was:547 (D.E. 153), 644 (D.E. 258) and 1.161 (D.E. 465) respectively. The average area ofR1 IOP, R2 IOP Y R3 IOP was: 0.06 mm2 (D. E. 0.02), 0.08 mm2 (D. E. 0.03), 0.14 mm2 (D. E. 0.06), respectively. The morphometric and stereological study of these nerve branches is expected to contribute to the information available to professionals who must clinically and surgically treat the plantar region of the foot.

A model for altered neural network dynamics related to prehension movements in Parkinson disease.

In this paper, we present a neural network model of the interactions between cortex and the basal ganglia during prehensile movements. Computational neuroscience methods are used to explore the hypothesis that the altered kinematic patterns observed in Parkinson's disease patients performing prehensile movements is mainly due to an altered neuronal activity located in the networks of cholinergic (ACh) interneurons of the striatum. These striatal cells, under a strong influence of the dopaminergic system, significantly contribute to the neural processing within the striatum and in the cortico-basal ganglia loops. In order to test this hypothesis, a large-scale model of neural interactions in the basal ganglia has been integrated with previous models accounting for the cortical organization of goal directed reaching and grasping movements in normal and perturbed conditions. We carry out a discussion of the model hypothesis validation by providing a control engineering analysis and by comparing results of real experiments with our simulation results in conditions resembling these original experiments.

X-ray diffraction, and Raman scattering study of nanostructured ZrO2-TiO2 oxides prepared by sol-gel.

In the present work, we study the phase composition of ZrO2-TiO2 system by means of XRD and Raman spectroscopy, using also TG-ATD, and N2 adsorption isotherms as complementary characterization techniques. TiO2-ZrO2 samples of selected compositions (0, 10, 90, 50 and 100% in weight of TiO2) were prepared by sol-gel method and annealed at three different temperatures (400, 600 and 800 degrees C). Structural characterization reveals that only the pure oxides are crystalline at 400 degrees C: TiO2 as anatasa with a minor brookite component, and ZrO2 as a mixture of tetragonal (majority) and monoclinic phases. Following the 600 degrees C calcination, the TiO2-ZrO2 50-50% sample forms the ZrTiO4 mixed oxide, although this materials remains partly amorphous. In contrast, samples with higher and lower TiO2 content form solid solutions with, respectively, anatasa and tetragonal ZrO2 structures. Zirconium incorporation into the TiO2 lattice leads to the expansion of the unit cell parameters, and it stabilizes the anatase phase, hindering its transformation into rutile. Similarly, dissolving titanium atoms into the ZrO2 structure delays the transformation from the tetragonal to the monoclinic polymorph.

Effects of the 3- and 4-methoxy and acetamide substituents and solvent environment on the electronic properties of N-substituted 1,8-naphthalimide derivatives.

The photophysical properties of polar molecules in solution with an intramolecular charge-transfer effect in the excited state depend strongly on the polarity and proticity of the solvents. UV-visible spectra of 1,8-naphthalimide and some N-substituted derivatives in acetic acid, acetonitrile, dichloromethane, and p-dioxane were carried out. Several molecular cluster geometries formed with N-substituted 1,8-naphthalimide derivatives and a large set of random positioning of some solvent molecules in their environment were optimized by a semiempirical method. It provided a complete screening of possible solute-solvent configurations and resulted in a multiple minima hypersurface of the supramolecular systems. With such local minima energies, the main thermodynamic association functions were found. They also provided selected cluster geometries for calculations of vertical electronic transitions with a time-dependent density functional theory (TD-DFT), if the lowest energy structures were considered. Calculated vertical electronic transition energies at the TD-DFT level were compared with experimental data. The experimental absorption UV-visible spectra for the six compounds in the four solvents were performed in our laboratory. Moreover, X-ray photoelectron spectroscospy of the 1,8-naphthalimide was carried out in the ICP-CSIC laboratory. Thermodynamic function values show different association energies between each solvent and the molecules, in correlation with the possibility of hydrogen bond formation and the polarity and dielectric constant of the solvents. The 3- and 4-acetamide 1,8-naphthalimide derivatives have the highest conformer number and the most negative Gibbs free association energy values for a determined solvent. This indicates the importance of the entropic factors.

A modular neural network architecture for step-wise learning of grasping tasks.

This paper proposes a neural network architecture for learning of grasping tasks. The multineural network model presented in this work, allows acquisition of different neural representations of the grasping task through a successive learning over two stages in a strategy that uses already learned representations for the acquisition of the subsequent knowledge. Systematic computer simulations have been carried out in order to test learning and generalization capabilities of the system. The neural activity at different subparts of the artificial neural network during its performance phase, is compared to the activity of populations of real neurons in areas AIP and F5 of the distributed parieto-frontal biological neural network involved in visual guidance of grasping. A more biologically plausible development of the model presented here is also discussed. The proposed model can be also used as a high level controller for a robotic dextrous hand during learning and execution of grasping tasks.

A neural network model for coordination of hand gesture during reach to grasp.

In this paper a neural network model for spatio-temporal coordination of hand gesture during prehension is proposed. The model includes a simplified control strategy for whole hand shaping during grasping tasks, that provides a realistic coordination among fingers. This strategy uses the increasing evidence that supports the view of a synergistic control of whole fingers during prehension. In this control scheme, only two parameters are needed to define the evolution of hand shape during the task performance. The proposal involves the design and development of a Library of Hand Gestures consisting of motor primitives for finger pre-shaping of an anthropomorphic dextrous hand. Through computer simulations, we show how neural dynamics of the model leads to simulated grasping movements with human-like kinematic features. The model can provide clear-cut predictions for experimental evaluation at both the behavioural and neural levels as well as a neural control system for a dextrous robotic hand.