Information manipulation and historical revisionism: Russian disinformation and foreign interference through manipulated history-based narratives.

Background: Disinformation and historical revisionism have been acknowledged as tools for foreign interference that belong to the landscape of hybrid threats. Historical revisionism plays an essential role in Russian foreign policy towards the post-Soviet space and is in strong relation with the concepts of Near Abroad and Russkii Mir ('Russian World') and with certain ideas contained in the neo-Eurasianist Movement. This article examines Russian revisionist narratives disseminated in information and influencing campaigns in Europe and against the West.       Methods: This study uses a mixed methodology combining desk research, including literature review, and analysis of the EUvsDisinfo database of cases identified before the February 2022 invasion of Ukraine. R esults: The manipulation of historical events has been largely employed by the Kremlin as a tool for foreign interference to achieve strategic objectives. First World War treaties, mainly the Trianon Peace Treaty, as well as the Second World War and the communist and fascist historical experiences in countries within the post-Soviet space, are the pivotal topics from which hostile influencing narratives are built. From the analysis of the EUvsDisinfo database, the article identifies seven topic themes.       Conclusions:  Our findings suggest that pre-emptively elaborated counter-narratives based on historical evidence and sound historiography can be an effective tool against hostile revisionist narratives that exploit vulnerabilities and specific target groups within European societies.

Estrategias de regulación de uso del smartphone y uso problemático de internet en la adolescencia / Regulatory strategies for smartphone use and problematic internet use in adolescence

La autorregulación constituye una habilidad básica que puede prevenir el uso problemático de internet y del smartphone en la etapa adolescente (LaRose et al., 2003). El presente estudio explora las estrategias de regulación del uso de este dispositivo, así como las relaciones de tales estrategias y de las variables antecedentes del modelo de Caplan (2010) para identificar a aquellos adolescentes que presentan altas o bajas consecuencias negativas del uso de internet. Con una muestra representativa de adolescentes de 1º a 4º de la ESO de la Comunidad de Madrid (N = 524, Medad = 13.57, DT = 1.24, Rango = 12-17), nuestros resultados apuntaron a que son los padres los que regulaban el uso del smartphone en cerca de la mitad de los adolescentes. El déficit de autorregulación con rumiación cognitiva, la intervención de los padres para regular el uso de este dispositivo y las variables del modelo de Caplan (2010) –excepto la regulación emocional online- fueron predictores significativos para identificar a aquellos adolescentes que mostraban altas o bajas consecuencias negativas. Las implicaciones educativas y las futuras líneas de investigación son resaltadas.

Self-regulation is a basic skill that can prevent problematic Internet and smartphone use in adolescence (LaRose et al., 2003). The present study explored regulation strategies in the use of this device, as well as the relationships between such strategies and the background variables of Caplan's (2010) model, to identify those adolescents who present high or low negative consequences of Internet use. With a representative sample of adolescents from 1st to 4th year of secondary education in the Community of Madrid (N = 524, Mage= 13.57, SD= 1.24, Range= 12-17), our results indicated that parents were the ones who regulated smartphone use in about half of the adolescents. Self-regulation deficit with cognitive rumination, parent intervention to regulate the use of this device and the variables of Caplan’s (2010) model -except for online emotional regulation- were significant predictors to identify those adolescents who showed high or low negative consequences. Educational implications and future lines of research are also discussed

Diagnóstico de osteocondromatosis como hallazgo casual en cirugía de fallo de enclavado endomedular de cadera / Diagnosis of osteochondromatosis as an incidental finding in revision surgery after failed intramedullary nailing of the hip

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Chondrosarcoma of the Hand Bones: A Report of 6 Cases and Review of the Literature.

BACKGROUND: Primary malignant tumours of the hand are extremely rare, with chondrosarcoma being the most common. We describe six consecutive cases of chondrosarcoma (CS) of the hand, with a follow-up of 12 months to 10 years after surgical intervention. METHODS: Five cases were primary tumors and one was secondary to Ollier's disease. Mean age at diagnosis was 67.5 years (range 46 to 85 years) and three patients were males. The bone most commonly affected was the proximal phalanx (in 4 patients), followed by the metacarpal bone (3 cases in the other 2 patients). The first symptom was an increase in volume in five cases and a pathological fracture in one. The x-ray study showed signs of malignancy in two cases only. In the other four cases, CT and MRI studies were necessary to complete the diagnosis. RESULTS: Primary amputation was performed in two cases and intralesional curettage and cancellous bone autograft in four. Primary amputation was performed in two cases and intralesional curettage and cancellous bone autograft in four. We found three grade I/III CS and three grade II/III CS in the histological study. Local recurrences occurred in three patients, two being grade II/III CS. One of the three had undergone an initial amputation and underwent re-amputation, another had had curettage of the lesion and was amputated, and the third patient decided not to undergo the procedure due to her age. A pulmonary nodule was suspected at the most recent follow up in a fourth patient, who had been diagnosed with a grade II/III CS. CONCLUSIONS: Although CS of the hand bones behaves as a locally aggressive lesion, it rarely metastasizes. Intralesional curettage with a cancellous bone autograft appears to be a good option in low-grade CS to preserve the function, keeping in mind the high rate of recurrence. Wide excision or amputation is recommended when severe joint deformity or soft tissue involvement interferes with hand function.

Catalysis and inhibition of tyrosinase in the presence of cinnamic acid and some of its derivatives.

The kinetic action of tyrosinase on l-tyrosine and l-Dopa as substrates in the presence of cinnamic acid and some of its derivatives has been characterized. Cinnamic acid, 2-hydroxycinnamic, 2,3 and 4-methoxycinnamic acids were seen to be inhibitors of tyrosinase being determined the type of inhibition and inhibition constants of all of them. However, 3-hydroxycinnamic, 4-hydroxycinnamic and 3,4-dihydroxycinnamic acids were seen to be substrates of tyrosinase at the same time. The kinetic constants of the catalysis of these substrates were determined and found to be perfectly correlated with the chemical shifts of the carbon with the phenolic hydroxyl group revealed by NMR. Docking studies of 2-hydroxycinnamic and 3-hydroxycinnamic acids showed that tyrosinase is able to hydroxylate 3-hydroxycinnamic acid but is unable to hydroxylate 2-hydroxycinnamic acid.

Enfoques big data para la comunicación en salud: análisis de redes y análisis de sentimientos a gran escala / Big data approaches in health communication: Network analysis and large-scale supervised sentiment analysis

Resumen Se exponen los dos principales enfoques metodológicos para la investigación con big data en comunicación en salud: el análisis de redes y el análisis de sentimientos. Primeramente, se explica el cambio de paradigma que está sufriendo el campo de la comunicación en salud gracias a los métodos computacionales para el análisis de datos masivos y se dan ejemplos de su uso en estudios y experiencias previas. Seguidamente, se exponen los conceptos (nodo/arista) y las principales variables de centralidad que se estudian en el análisis de red en procesos de difusión de innovaciones en salud; y, finalmente, se explica cómo ejecutar el procedimiento de análisis de sentimientos supervisado para estudiar contenidos de salud a gran escala.

Abstract The two main methodological approaches for research with big data in health communication are presented: network analysis and the analysis of feelings. Firstly, the paradigm change that the communication field in health is experiencing, thanks to the computational methods for the analysis of massive data, and examples of its use in previous studies and experiences are explained. Next, the concepts (node / edge) and the main centrality variables that are studied in the network analysis in health innovation dissemination processes are exposed; and, finally, it is explained how to execute the supervised feelings analysis procedure to study large-scale health content

Action of tyrosinase on caffeic acid and its n-nonyl ester. Catalysis and suicide inactivation.

Different mechanisms for inhibiting tyrosinase can be designed to avoid postharvest quality losses of fruits and vegetables. The action of tyrosinase on caffeic acid and its n-nonyl ester (n-nonyl caffeate) was characterized kinetically in this work. The results lead us to propose that both compounds are suicide substrates of tyrosinase, for which we establish the catalytic and inactivation efficiencies. The ester is more potent as inactivator than the caffeic acid and the number of turnovers made by one molecule of the enzyme before its inactivation (r) is lower for the ester. We proposed that the anti-browning and antibacterial properties may be due to suicide inactivation processes.

Lesión simultánea de ambos ligamentos colaterales de la articulación metacarpofalángica del pulgar. Reporte de caso / Simultaneous injury of both ligaments at the metacarpophalangeal joint of the thumb. Case report

Presentamos un caso de fractura simultánea por avulsión de ambos ligamentos colaterales de la articulación metacarpofalángica del pulgar. Se analizan el mecanismo de la lesión y el tratamiento utilizado. Nivel de evidencia clínica. Nivel IV.

We report a case of simultaneous avulsion fracture of both collateral ligaments of the metacarpophalangeal joint of the thumb. The mechanism of injury and treatment used are analyzed. Evidence level. IV

Structural and kinetic considerations on the catalysis of deoxyarbutin by tyrosinase.

Deoxyarbutin, a potent inhibitor of tyrosinase, could act as substrate of the enzyme. Oxytyrosinase is able to hydroxylate deoxyarbutin and finishes the catalytic cycle by oxidizing the formed o-diphenol to quinone, while the enzyme becomes deoxytyrosinase, which evolves to oxytyrosinase in the presence of oxygen. This compound is the only one described that does not release o-diphenol after the hydroxylation step. Oxytyrosinase hydroxylates the deoxyarbutin in ortho position of the phenolic hydroxyl group by means of an aromatic electrophilic substitution. As the oxygen orbitals and the copper atoms are not coplanar, but in axial/equatorial position, the concerted oxidation/reduction cannot occur and the release of a copper atom to bind again in coplanar position, enabling the oxidation/reduction or release of the o-diphenol from the active site to the medium. In the case of deoxyarbutin, the o-diphenol formed is repulsed by the water due to its hydrophobicity, and so can bind correctly and be oxidized to a quinone before being released. Deoxyarbutin has been characterized with: [Formula: see text] = 1.95 ± 0.06 s-1 and [Formula: see text] = 33 ± 4 µM. Computational simulations of the interaction of ß-arbutin, deoxyarbutin and their o-diphenol products with tyrosinase show how these ligands bind at the copper centre of tyrosinase. The presence of an energy barrier in the release of the o-diphenol product of deoxyarbutin, which is not present in the case of ß-arbutin, together with the differences in polarity and, consequently differences in their interaction with water help understand the differences in the kinetic behaviour of both compounds. Therefore, it is proposed that the release of the o-diphenol product of deoxyarbutin from the active site might be slower than in the case of ß-arbutin, contributing to its oxidation to a quinone before being released from the protein into the water phase.

Action of tyrosinase on alpha and beta-arbutin: A kinetic study.

The known derivatives from hydroquinone, α and ß-arbutin, are used as depigmenting agents. In this work, we demonstrate that the oxy form of tyrosinase (oxytyrosinase) hydroxylates α and ß-arbutin in ortho position of the phenolic hydroxyl group, giving rise to a complex formed by met-tyrosinase with the hydroxylated α or ß-arbutin. This complex could evolve in two ways: by oxidizing the originated o-diphenol to o-quinone and deoxy-tyrosinase, or by delivering the o-diphenol and met-tyrosinase to the medium, which would produce the self-activation of the system. Note that the quinones generated in both cases are unstable, so the catalysis cannot be studied quantitatively. However, if 3-methyl-2-benzothiazolinone hydrazone hydrochloride hydrate is used, the o-quinone is attacked, so that it becomes an adduct, which can be oxidized by another molecule of o-quinone, generating o-diphenol in the medium. In this way, the system reaches the steady state and originates a chromophore, which, in turn, has a high absorptivity in the visible spectrum. This reaction allowed us to characterize α and ß-arbutin kinetically as substrates of tyrosinase for the first time, obtaining a Michaelis constant values of 6.5 ± 0.58 mM and 3 ± 0.19 mM, respectively. The data agree with those from docking studies that showed that the enzyme has a higher affinity for ß-arbutin. Moreover, the catalytic constants obtained by the kinetic studies (catalytic constant = 4.43 ± 0.33 s-1 and 3.7 ± 0.29 s-1 for α and ß-arbutin respectively) agree with our forecast based on 13 C NMR considerations. This kinetic characterization of α and ß-arbutin as substrates of tyrosinase should be taken into account to explain possible adverse effects of these compounds.

Spectrophotometric Characterization of the Action of Tyrosinase on p-Coumaric and Caffeic Acids: Characteristics of o-Caffeoquinone.

New methods are proposed to determine the activity of tyrosinase on caffeic and p-coumaric acids. Because o-quinone from caffeic acid is unstable in its presence, it has been characterized through spectrophotometric measurements of the disappearance of coupled reducing agents, such as nicotinamide adenine dinucleotide reduced form. It has also been characterized by a chronometric method, measuring the time that a known concentration of ascorbic acid takes to be consumed. The activity on p-coumaric acid has been followed by measuring the formation of o-quinone of caffeic acid at the isosbestic point originated between caffeic acid and o-caffeoquinone and measuring the formation of o-quinone at 410 nm, which is stable in the presence of p-coumaric acid (both of them in the presence of catalytic amounts of caffeic acid, maintaining the ratio between p-coumaric acid and caffeic acid constant; R = 0.025). The kcat value of tyrosinase obtained for caffeic acid was higher than that obtained for p-coumaric acid, while the affinity was higher for p-coumaric acid. These values agree with those obtained in docking studies involving these substrates and oxytyrosinase.

Action of 2,2',4,4'-tetrahydroxybenzophenone in the biosynthesis pathway of melanin.

2,2',4,4'-tetrahydroxybenzophenone (Uvinul D50), a sunscreen used in cosmetics, has two effects in the melanin biosynthesis pathway. On the one hand, it acts a weak inhibitor of tyrosinase and on the other, it accelerates the conversion of dopachrome to melanin. Uvinul D50 was seen to behave as a weak competitive inhibitor: apparent constant inhibition=2.02±0.09mM and IC50=3.82±0.39mM established in this work. These values are higher than those in the bibliography, which tend to be undersetimated. This discrepancy could be explained by the reaction of Uvinul D50 with the dopachrome produced from l-tyrosine or l-dopa, which would interfere in the measurement. Based on studies of its docking to tyrosinase, it seems that Uvinul D50 interacts with the active site of the enzyme (oxytyrosinase) both in its protonated and deprotonated forms (pKa=7). However, it cannot be hydroxylated, meaning that it acts as a weak inhibitor, not as an alternative substrate, despite its resorcinol structure. Uvinul D50 can be used as sunscreen, in low concentrations without significant adverse effects on melanogenesis.

Characterization of the action of tyrosinase on resorcinols.

The action of tyrosinase on resorcinol and some derivatives (4-ethylresorcinol, 2-methylresorcinol and 4-methylresorcinol) was investigated. If the catalytic cycle is completed with a reductant such as ascorbic acid or an o-diphenol such as 4-tert-butylcatechol, these compounds act as substrates of tyrosinase in all cases. The reaction can also be carried out, adding hydrogen peroxide to the medium. All the above compounds were characterized as substrates of the enzyme and their kinetic constants, KM (Michaelis constant) and kcat (catalytic constant) were determined. Measurement of the activity of the enzyme after pre-incubation with resorcinol, 4-ethylresorcinol or 4-methylresorcinol points to an apparent loss of activity at short times, which could correspond to an enzymatic inactivation process. However, if the measurements are extended over longer times, a burst is observed and the enzymatic activity is recovered, demonstrating that these compounds are not suicide substrates of the enzyme. These effects are not observed with 2-methylresorcinol. The docking results indicate that the binding of met-tyrosinase with these resorcinols occurs in the same way, but not with 2-methylresorcinol, due to steric hindrance.

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase.

4-n-Butylresorcinol (BR) is considered the most potent inhibitor of tyrosinase, which is why it is used in cosmetics as a depigmenting agent. However, this work demonstrates that BR is a substrate of this enzyme. The Em (met-tyrosinase) form is not active on BR, but Eox (oxy-tyrosinase) can act on this molecule, hydroxylating it to o-diphenol. In turn, this is oxidized to an o-quinone, which isomerizes to a red p-quinone. Thus, for tyrosinase to act on this compound, a mechanism to generate Eox in the medium is required, which can be achieved by means of hydrogen peroxide or ascorbic acid. A kinetic analysis of the proposed mechanism allows its kinetic characterization: catalytic constant kcatBR (8.49 ± 0.20 s(-1) ) and Michaelis-constant KMBR (60.26 ± 8.76 µM). These findings are compared with those for other monophenolic substrates of tyrosinase. Studies of BR docking to the Em form of the enzyme show that the hydroxyl group in C-1 position is oriented toward the copper atom A (CuA), as in it is L-tyrosine. As regards Eox , BR is oriented with the carbon in C-6 position ready to be hydroxylated. The reaction of BR originates o-quinones, which isomerize to p-quinones, which in turn, could react with thiol compounds, a finding that could have important implications for pharmacology and the cosmetic industry. © 2016 IUBMB Life, 68(8):663-672, 2016.

Septic arthritis due to Clostridium ramosum.

OBJECTIVES: Clostridium species are anaerobic bacilli that are rarely reported as etiologic agents of infectious arthritis. Previous cases of arthritis caused by Clostridium ramosum have not been reported. We describe the first 2 cases of C. ramosum arthritis. METHODS: We reviewed the etiology of arthritis in our hospital during the previous 15 years. RESULTS: Both patients had underlying immunocompromising conditions and their infections involved a joint with preexisting disease: patient 1 had rheumatic arthritis and a prosthetic joint; patient 2, chronic renal failure on dialysis and hip osteoarthritis. The infection was hematogenously acquired and the course was indolent but destructive in both the cases. Management included open arthrotomy and resection arthroplasty. The infection had a persisting and relapsing course, and prolonged antibiotic treatment was required. In the literature review, we found 55 previous cases of arthritis caused by Clostridium species between 1966 and 2014; Clostridium perfringens was the most common infecting species; the infection was traumatically acquired in most of the cases. A total of 15 patients have been described with infections caused by C. ramosum; none had septic arthritis. The majority were elderly or immunocompromised adults. Proper collection, transportation and processing of clinical specimens is essential for diagnosing clostridial infections. More information about the best management of clostridial arthritis are needed. CONCLUSIONS: We describe the first 2 cases of septic arthritis caused by C. ramosum. They shared several pathogenic and clinical features. The possibility of anaerobic arthritis should always be considered when collecting diagnostic specimens. An increasing number of clostridial arthritis cases are likely to be diagnosed in future years.

Luxación de tobillo sin fractura asociada: caso clínico y nueva clasificación / Luxation de cheville sans fracture associée: cas clinique, nouvelle classification / Ankle dislocation with no associated fracture: a case and new classification

La luxación cerrada sin fractura asociada de tobillo es una entidad extremadamente rara. Se presenta el caso de un hombre de 35 años que se lesionó mientras jugaba fútbol. El tratamiento consistió en reducción cerrada seguido de inmovilización con una botina de yeso durante 6 semanas y descarga de la extremidad las primeras 10 semanas. A los 12 meses de seguimiento, el paciente había retomado la práctica deportiva con un rango de movimiento completo. Se revisó la bibliografía existente y se propone una nueva clasificación(AU)

Closed dislocation of ankle with no associated fracture is an extremely rare entity. A case of 35 year-old man who was injured while playing soccer is presented. The treatment consists of closed reduction followed by immobilization with a walking cast for 6 weeks and unloading of the injured extremity the first 10 weeks. At 12 months follow-up, the patient had reinitiated sport at full range of motion. The literature was reviewed and a new classification is proposed(AU)

La luxation fermée de cheville sans fracture associée est une affection très rare. Le cas d’un homme (35 ans) lésé en jouant au football est présenté. Le traitement a consisté en réduction fermée, suivie d’immobilisation par botte plâtrée pendant 6 semaines, et mise en décharge du membre inférieur les dix premières semaines. Douze mois après, le patient a repris la pratique sportive en un rang de mouvement complet. On a fait une revue de la littérature, et on propose une nouvelle classification(AU)

Luxación traumática de cadera en un niño / Luxation traumatique de hanche chez l'enfant / Traumatic hip dislocation in a child

Introducción: la luxación traumática de cadera en un paciente pediátrico es una lesión muy infrecuente. No existe consenso sobre su manejo óptimo en urgencias y el seguimiento posterior. Reporte de caso: se reporta el caso de un niño de 4 años que sufrió una luxación traumática de cadera derecha mientras esquiaba. Recibió tratamiento conservador que consistió en reducción cerrada y sin inmovilización posterior. Se realizó una revisión de la literatura sobre esta lesión traumática, su tratamiento y seguimiento. Se mencionan las características diferenciales de la entidad en la población adulta. Resultados: en el presente caso, los resultados fueron muy satisfactorios, pues el paciente tuvo una recuperación funcional completa con un nivel de vida equiparable al que tenía antes de la luxación. Conclusión: la luxación traumática de cadera en la población pediátrica es infrecuente. Sin embargo, dada la importancia de su reducción a la mayor brevedad posible con el objetivo de evitar complicaciones posteriores como la osteonecrosis avascular, es preciso diagnosticarla y tratarla lo más precozmente posible. No existe consenso, sin embargo, en cuanto al tratamiento y seguimiento óptimo de esta afección una vez resuelto el episodio agudo(AU)

Introduction: traumatic hip dislocation in a pediatric patient is a rare injury. There is no consensus on the optimal management in its emergency and follow-up. Case report: the case of a 4 year-old boy who suffered a traumatic dislocation of the right hip while skiing is reported. He received conservative treatment consisting of closed reduction and with no further immobilization. A review of the literature on this traumatic injury, treatment and follow-up was performed. The differential characteristics of the above entity in the adult population are mentioned. Results: in the present case, the results were very satisfactory, since the patient had complete functional recovery with same level of life that he had before the dislocation. Conclusion: traumatic hip dislocation in pediatric population is rare. However, given the importance of its reduction as soon as possible in order to avoid further complications such as avascular osteonecrosis, diagnosis and treatment is necessary as early as possible. There is no consensus, however, as to the optimal treatment and monitoring of the condition after an acute episode is solved(AU)

Introduction: la luxation traumatique de hanche est une lésion peu fréquente chez l'enfant. Il n'existe pas de consensus sur sa prise en charge en urgences et son suivi subséquent. Rapport de cas: le cas d'un enfant âgé de 4 ans ayant souffert une luxation traumatique de la hanche droite lors du ski est rapporté. Il a eu un traitement conservateur consistant en réduction fermée sans immobilisation ultérieur. On a fait une revue de la littérature de cette lésion traumatique, son traitement et son suivi. Les caractéristiques de différentiation de cette affection dans une population adulte sont mentionnées. Résultats: dans ce cas, les résultats ont été satisfaisants, car le patient a eu une complète récupération fonctionnelle lui permettant un niveau de vie comparable à celui qu'il menait avant la luxation. Conclusions: la luxation traumatique de hanche est peu fréquente chez l'enfant. Il est pourtant nécessaire de la diagnostiquer et la traiter précocement pour éviter des complications telles que l'ostéonécrose avasculaire. Mais, il n'existe pas encore de consensus sur un traitement et un suivi appropriés(AU)