Development, characterization and sterilisation of Nanocellulose-alginate-(hyaluronic acid)- bioinks and 3D bioprinted scaffolds for tissue engineering.

3D-bioprinting is an emerging technology of high potential in tissue engineering (TE), since it shows effective control over scaffold fabrication and cell distribution. Biopolymers such as alginate (Alg), nanofibrillated cellulose (NC) and hyaluronic acid (HA) offer excellent characteristics for use as bioinks due to their excellent biocompatibility and rheological properties. Cell incorporation into the bioink requires sterilisation assurance, and autoclave, ß-radiation and γ-radiation are widely used sterilisation techniques in biomedicine; however, their use in 3D-bioprinting for bioinks sterilisation is still in their early stages. In this study, different sterilisation procedures were applied on NC-Alg and NC-Alg-HA bioinks and their effect on several parameters was evaluated. Results demonstrated that NC-Alg and NC-Alg-HA bioinks suffered relevant rheological and physicochemical modifications after sterilisation; yet, it can be concluded that the short cycle autoclave is the best option to sterilise both NC-Alg based cell-free bioinks, and that the incorporation of HA to the NC-Alg bioink improves its characteristics. Additionally, 3D scaffolds were bioprinted and specifically characterized as well as the D1 mesenchymal stromal cells (D1-MSCs) embedded for cell viability analysis. Notably, the addition of HA demonstrates better scaffold properties, together with higher biocompatibility and cell viability in comparison with the NC-Alg scaffolds. Thus, the use of MSCs containing NC-Alg based scaffolds may become a feasible tissue engineering approach for regenerative medicine.

Abordaje transconjuntival: primera elección en trauma orbitario / Transconjuntival approach: first choice in orbit trauma

OBJETIVO: Describir la eficacia del abordaje transconjuntival para el tratamiento de fracturas orbitarias con compromiso del suelo de la órbita y las posibles complicaciones asociadas a este abordaje. Material y MÉTODO: Es un estudio retrospectivo descriptivo en base a 98 pacientes con fractura de órbita donde se utilizó el abordaje transconjuntival, en el Servicio de Cirugía Maxilofacial del Hospital Clínico Mutual de Seguridad de Santiago de Chile, entre enero del 2012 y abril del 2017. Se determinó la tasa de éxito de dicha técnica y las variables con mayor predisposición a producir complicaciones. Los criterios de inclusión fueron pacientes con fracturas del complejo maxilofacial con compromiso de una o más paredes orbitarias. Se utilizó el test de Fisher para el análisis de datos, siendo significativo un p value < 0,05. RESULTADOS: Los resultados obtenidos con el abordaje transconjuntival utilizado para el tratamiento de fracturas del complejo orbitomalar demuestran una alta tasa de éxito (94 %) en relación con las escasas complicaciones (6 %). Usando el test Fisher, las complicaciones estuvieron asociadas a fracturas maxilofaciales complejas por accidentes de alta energía, que traen como consecuencia gran destrucción del complejo orbitario, afectándose frecuentemente el aparato lagrimal, en reintervenciones usando el mismo acceso del abordaje, y en variaciones de la técnica en que se utilizó el abordaje transconjuntival con cantotomía lateral y/o retrocaruncular. CONCLUSIONES: El abordaje transconjuntival es una excelente alternativa en fracturas del complejo orbitomaxilo malar, especialmente para acceder al suelo de la órbita y al reborde infraorbitario, por sus mínimas complicaciones, pronóstico favorable y técnica de baja complejidad

OBJECTIVE: To describe the efficacy of the transconjunctival approach in orbital and orbital floor fractures and the possible complications associated with this approach. MATERIAL AND METHOD: This is a retrospective descriptive study based on 98 patients with orbital fractures where the transconjunctival approach was used in the Maxillofacial Surgery Service of Mutual de Seguridad Hospital, Santiago - Chile, between January 2012 and April 2017. The success rate of this technique and the variables with greater predisposition to generate complications were determined. The inclusion criteria were patients with fractures of the maxillofacial complex with involvement of one or more orbital walls. Fisher's test was used for the data analysis, p - value <0.05 being significant. RESULTS: Results obtained in our study demonstrate a high success rate (94%) in relation to the transconjunctival approach used for orbitozygomatic complex fractures treatments, with few complications observed (6%). Using the Fisher's test, complications were associated with complex maxillofacial fractures due to high energy accidents, which resulted in great destruction of the orbital complex, frequently affecting the lacrimal apparatus, in reinterventions using the same approach access and in variations of the technique in which the transconjunctival approach with lateral cantotomy and / or retrocaruncular extension was used. CONCLUSIONS: The transconjunctival approach is an excellent alternative in orbitozygomatic maxilar complex fractures, especially to access the orbital floor and the infraorbital rim, due to its minimal complications and favorable prognosis

Type 1 Diabetes Mellitus reversal via implantation of magnetically purified microencapsulated pseudoislets.

Microencapsulation of pancreatic islets for the treatment of Type I Diabetes Mellitus (T1DM) generates a high quantity of empty microcapsules, resulting in high therapeutic graft volumes that can enhance the host's immune response. We report a 3D printed microfluidic magnetic sorting device for microcapsules purification with the objective to reduce the number of empty microcapsules prior transplantation. In this study, INS1E pseudoislets were microencapsulated within alginate (A) and alginate-poly-L-lysine-alginate (APA) microcapsules and purified through the microfluidic device. APA microcapsules demonstrated higher mechanical integrity and stability than A microcapsules, showing better pseudoislets viability and biological function. Importantly, we obtained a reduction of the graft volume of 77.5% for A microcapsules and 78.6% for APA microcapsules. After subcutaneous implantation of induced diabetic Wistar rats with magnetically purified APA microencapsulated pseudoislets, blood glucose levels were restored into normoglycemia (<200 mg/dL) for almost 17 weeks. In conclusion, our described microfluidic magnetic sorting device represents a great alternative approach for the graft volume reduction of microencapsulated pseudoislets and its application in T1DM disease.

Silk flow-diverter stent for the treatment of complex intracranial aneurysms: A one-year follow-up multicenter study.

Background Flow-diverter stents have been successfully used in the treatment of complex aneurysms with limited therapeutic alternatives. We report our experience using the Silk flow diverter (SFD; Balt Extrusion, Montmorency, France) for the treatment of complex aneurysms in four Argentine centers. Methods We conducted a retrospective review of 246 consecutive patients who were treated with the SFD at four Argentine centers between January 2009 and January 2017. The patient and aneurysm characteristics, as well as the details of the procedure, were analyzed. The angiographic and clinical findings were recorded during and immediately after the procedure and at 12-month follow-up. Results Angiography follow-up at 12 months was possible in 235 patients (95.5%) with 282 aneurysms. A total of 265 aneurysms (93.9%) presented with complete occlusion of the aneurysmal sac (class 1) and 17 aneurysms (6.1%) presented with partial occlusion (class 2). The 12-month clinical follow-up showed 11 patients with major events (seven, scale 2; five, scale 3; and two, scale 4). The morbidity and mortality rates were 4.2% (11/289) and 2.1% (5/289), respectively. Conclusions The treatment of aneurysms with the SFD was associated with a low rate of complications and a high percentage of aneurysmal occlusion. These findings suggest that SFD is an effective and safe alternative in the endovascular treatment of complex aneurysms.

Concordancia entre la PET cerebral con 18F-FDG y los biomarcadores en líquido cefalorraquídeo en el diagnóstico de enfermedad de Alzheimer / Concordance between brain 18F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease

Objetivos. El hipometabolismo cortical posterior por PET con 18F-FDG (PET-FDG) y la alteración de los niveles del péptido Aß1-42 y las proteínas Tau total (tTau) y Tau fosforilada (pTau) en líquido cefalorraquídeo (LCR) son biomarcadores establecidos para el diagnóstico de la enfermedad de Alzheimer (EA). Evaluamos la concordancia y la relación entre los resultados de la PET-FDG y los biomarcadores en LCR en pacientes sintomáticos con sospecha de EA. Material y métodos. Revisión retrospectiva de 120 pacientes con deterioro cognitivo admitidos en la Unidad de Neurología Cognitiva a los que se les ha realizado punción lumbar para la determinación de biomarcadores en LCR y una PET-FDG cerebral. Para el análisis de concordancia (coeficiente Kappa), el resultado de la PET-FDG y del conjunto de los biomarcadores-LCR se clasificó en cada paciente como normal, no-concluyente, o compatible-EA. Se efectuó además una regresión logística incluyendo las variables cuantitativas Aß1-42, tTau y pTau como predictores y la PET-FDG como variable dependiente. Resultados. El coeficiente Kappa ponderado entre PET-FDG y biomarcadores-LCR fue de 0,46 (IC 95%: 0,35-0,57). En el análisis por regresión logística, la Aß1-42 y la tTau fueron en conjunto capaces de discriminar un resultado PET metabólicamente sugestivo de EA de uno no sugestivo de EA, con una sensibilidad del 91% y una especificidad del 93% aplicando la recta de corte Aß1-42=44+1,3×tTau. Conclusiones. La concordancia entre la PET-FDG cerebral y los biomarcadores-LCR es moderada, lo cual indica su valor complementario en el diagnóstico de EA. Los niveles de Aß1-42 y tTau en LCR son buenos predictores del estatus metabólico característico de EA por PET-FDG cerebral (AU)

Objectives. Cortical posterior hypometabolism on PET imaging with 18F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. Material and methods. A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. Results. The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. Conclusions. The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status (AU)

Concordance between brain 18F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease. / Concordancia entre la PET cerebral con 18F-FDG y los biomarcadores en líquido cefalorraquídeo en el diagnóstico de enfermedad de Alzheimer.

OBJECTIVES: Cortical posterior hypometabolism on PET imaging with 18F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. MATERIAL AND METHODS: A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. RESULTS: The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. CONCLUSIONS: The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status.

Más allá de la orden de no resucitar / Beyond the do-not-resuscitate (DNR) order

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Metal exposure influences the melanin and carotenoid-based colorations in great tits.

Metals are naturally found in the environment but are also emitted through anthropogenic activities, raising some concerns about the potential deleterious effects of these elements on wildlife. The potential effects of metals on bird coloration have been the focus of several recent studies since animal colored-signals often reflect the physiology of their bearers and are thus used by animals to assess the quality of another individual as a mate or competitor. These studies have shown that the melanin pigmentation seems to be positively associated and the carotenoid-based coloration negatively associated with metal exposure in wild birds. Although these studies have been very useful to show the associations between metal exposure and coloration, only few of them have actually quantified the levels of metal exposure at the individual level; always focusing on one or two of them. Here, we measured the concentrations of eight metals in great tits' feathers and then assessed how these levels of metals were associated with the carotenoid and melanin-based colorations. We found that the melanin pigmentation was positively associated with the copper concentration and negatively correlated with the chromium concentration in feathers. In addition, we have shown that the carotenoid-based coloration was negatively associated with the feather's mercury concentration. This study is the first one to identify some metals that might affect positively and negatively the deposition of melanin and carotenoid into the plumage of wild birds.

Darkness during early postnatal development is required for normal circadian patterns in the adult rat.

Early light experience influences the brain during development. Perinatal light exposure has an important effect on the development of the circadian system, although the role of quantity versus quality of light in this process is still unclear. We tested the development of the circadian rhythm of locomotor activity under constant bright light from the day of weaning, of six groups of rats raised under different light conditions during suckling. Results indicated that when rats received daily darkness during suckling (rats reared under constant darkness or light-dark cycles with dim or bright light) became arrhythmic when exposed to continuous bright light after weaning. However, those rats reared in the absence of darkness (constant dim or bright light, or alternating dim and bright light) developed a circadian rhythm, which was stronger and had a shorter period depending on the quantity of light received during suckling. Vasointestinal polypeptide immunoreactivity in the suprachiasmatic nucleus (SCN) was higher in those rats with weaker rhythms. However, no apparent differences among these groups were found in the melanopsin-expressing retinal ganglion cells, which provide the SCN with light input in the photoentrainment process. When bright light was shifted to dim light in three of the groups on day 57 after weaning, all of them generated a circadian rhythm with a longer period in those rats previously arrhythmic. Our results indicate the importance of the amount of light received at the early stages of life in the development of the circadian system and suggest that darkness is needed for the normal development of circadian behaviour.

Simulación clínica en vuelo para el manejo del paciente crítico en aeroevacuación avanzada y táctica en Afganistán / Flight clinical simulation for critical care support in forward and tactical aeroevacuation in Afghanistan

Los diferentes relevos de tripulaciones sanitarias en el puesto de MEDEVAC perteneciente al destacamento HELISAF en Herat requieren coordinación y trabajo en equipo en condiciones adversas. Por este motivo se decidió realizar adiestramiento mediante códigos mega con simuladores que permitieran pone en práctica técnicas de soporte vital avanzado con incidencias múltiples. Exponemos el escenario de trabajo, las características espéciales de la simulación, el procedimiento empleado, las recomendaciones específicas asistenciales y la conclusión de la experiencia. El artículo desarrolla la experiencia obtenida al realizar prácticas de simulación clínica durante el vuelo de helicópteros HD-21 en Afganistán (AU)

Medical crews in MEDEVAC job description that belongs to HELISAF deployment requires coordination and teamwork in adverse conditions. For this reason, were performed clinical simulations to practice advance life support with some incidents. Theater system and special conditions in the simulations are described. As well as procedures and specific care recommendations. Finally conclusions are presented. The purpose of this report is to show the experience gained in performing clinical simulation in HD-21 «Superpuma» helicopter in Afghanistan (AU)

Conciliación de los medicamentos en los servicios de urgencias / Medication reconciliation in emergency departments

Los errores de medicación (EM) son comunes en el ámbito hospitalario y conducen aun incremento de la morbilidad y mortalidad y de los costes económicos. Estos errores ocurren sobre todo durante la transición de pacientes entre los diferentes niveles asistenciales. La posibilidad de que se produzcan estos errores se ve aumentada en los servicios de urgencias (SU) por la naturaleza de éstos. Desde instituciones sanitarias a nivel mundial, se reconoce la conciliación de la medicación (CM) como la solución a esta problemática. Se define como el proceso que consiste en obtener un listado completo y exacto de la medicación previa del paciente y compararlo con la prescripción médica después de la transición asistencial. Si se encuentran discrepancias deben considerarse y, si es necesario, modificar la prescripción médica para finalmente comunicar al siguiente responsable en salud del paciente y al propio paciente, la nueva lista conciliada. Este documento de consenso ofrece una serie de recomendaciones generales para la conciliación de los medicamentos. Incluye para cada subgrupo una serie de recomendaciones específicas de tipo farmacológico, que permiten un abordaje personalizado del tratamiento del paciente que acude a urgencias en base a las características clínicas individuales. Existirán casos en los que se desestime las recomendaciones aquí descritas, ya que la relación riesgo/beneficio requerirá una valoración individualizada. Esta valoración individualizada para el paciente se llevará a cabo por el equipo multidisciplinar responsable de su asistencia sanitaria (AU)

Medication errors, which are common in hospitals, lead to higher morbidity, mortality, and expenditure. Errors are most common when patients are transferred from one level of care to another, and the likelihood of mistakes is higher in emergency departments because of the intrinsic nature of emergency care. The internationally recognized remedy for this situation is medication reconciliation, defined as the process of obtaining a complete, accurate list of the patient's prior medications and comparing it to the list of medicines prescribed after admission to a new level of care. Discrepancies should be considered and prescriptions changed if necessary. Both the person who will be responsible for the next phase of care and the patient should be informed of the new list of medications. This consensus statement offers a set of general recommendations for medication reconciliation. Specific recommendations for each subgroup of medications are also included to allow emergency department prescribing to be tailored to individual patient characteristics. The recommendations in this statement should be overridden in some cases if the risk-benefit ratio suggests that further individualization is required. Individualized assessment of medications should be carried out by a multidisciplinary team responsible for the patient’s care (AU)

[Palpitations in stress situations]. / Palpitaciones en situación de estrés.

Wolff-Parkinson-White (WPW) syndrome, a congenital heart abnormality, is the most common of the pre-excitation syndromes. The prevalence of WPW syndrome ranges from 0.1 to 3 cases per 1000 people. A large majority (80%) of patients with WPW syndrome develop supraventricular tachycardia, between 15% and 30% atrial fibrillation, and atrial flutter 5%. The clinical presentation can vary from vertigo, palpitations, breathlessness, chest tightness, to sudden death in rare cases. We report the case of a patient presenting with WPW syndrome after a stressful work situation.

Palpitaciones en situación de estrés / Palpitations in stress situations

El síndrome de Wolff-Parkinson-White (WPW) es el más frecuente de los síndromes de preexcitación, una alteración cardiaca congénita. La prevalencia del síndrome de WPW oscila de 0,1 a 3 casos por cada 1.000 habitantes. El 80% de los pacientes con síndrome de WPW desarrollarán taquicardia supraventricular; entre un 15 y un 30%, fibrilación auricular, y un 5%, flutter auricular. La forma de presentación clínica puede ser muy variada, desde palpitaciones a vértigo, disnea, opresión torácica, hasta la muerte súbita en raras ocasiones. Exponemos el caso de una paciente que presenta síndrome de WPW después de una situación laboral estresante (AU)

Wolff-Parkinson-White (WPW) syndrome, a congenital heart abnormality, is the most common of the pre-excitation syndromes. The prevalence of WPW syndrome ranges from 0.1 to 3 cases per 1000 people. A large majority (80%) of patients with WPW syndrome develop supraventricular tachycardia, between 15% and 30% atrial fibrillation, and atrial flutter 5%. The clinical presentation can vary from vertigo, palpitations, breathlessness, chest tightness, to sudden death in rare cases. We report the case of a patient presenting with WPW syndrome after a stressful work situation (AU)

Pececitos, no gracias / Small fish, no thank you

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Social interaction and sex differences influence rat temperature circadian rhythm under LD cycles and constant light.

Circadian rhythms produce an efficient organization of animal behaviour over the 24h day. In some species, social cues have been found to have a role as synchronizers of these rhythms. Here, the influence of social interaction on rat circadian behaviour was investigated, addressing the question of whether cohabitation would produce a delay in the appearance of arrhythmicity under constant light conditions. To this end, the circadian rhythms of male and female rat body temperature were studied for 10days under light-dark conditions, followed by 33days under constant bright light. Half of the animals were maintained in individual cages, whilst the others were maintained in larger cages in groups of three rats of the same sex. Results showed that individual circadian rhythms under 24hour light-dark (LD) cycles were more stable and with higher amplitude in grouped than in isolated animals, and higher in males than in females. During the first days under constant light (LL), the stability of the rhythm was also higher in males than in females, but there were no differences according to the group. Moreover, we did not find significant differences in the time of circadian rhythm loss under LL, since high individual variability was found for this variable. On the other hand, female rats living in isolation showed a delayed acrophase in the circadian rhythm under LD conditions compared with those living in groups. These results suggest that cohabitation increases the internal coherence of circadian behaviour, and could be interpreted as indicating that living in isolation may induce a level of stress that disturbs manifestation of the circadian rhythm, especially in females, which are also more reactive than males to external signals.

Enfermedad de Scheuermann / Scheuermann's disease

Presentamos dos casos clínicos de dos pacientes diagnosticados después de una detenida anamnesis y exploración física completa, y con la ayuda de una simple radiología convencional, de enfermedad de Scheuermann. Habitualmente es un hallazgo casual, pues la mayoría de las veces son pacientes asintomáticos, pero, en estos dos casos es a raíz de un dolor dorsal-lumbar persistente, inicialmente atribuido a esfuerzo en el trabajo o a una mala postura, que al persistir les hace acudir al médico de familia. Inicialmente los hallazgos radiológicos consisten en irregularidades del margen superior de la mayoría o de todas las vértebras, esclerosis y formación de nódulos cartilaginosos en una proyección radiológica lateral. En los casos en los que las lesiones progresan, se observa que las vértebras adquieren forma de cuña, de tal manera que la cifosis dorsal normal aumenta a un grado patológico (AU)

We present two cases of two patients diagnosed Scheuermann's disease after a detailed anamnesis and complete physical examination, and with the help of a simple conventional radiology. This is usually a casual finding as most patients are often asymptomatic, but in both cases there was a persistent dorsal-lumbar pain initially attributed to work effort or poor posture, which made them go to the family doctor. Initially, the radiological findings are irregularities in the upper of most or all of the vertebrae, sclerosis and formation of cartilaginous nodules in a lateral x-ray projection. In some cases where the lesions are progressing, it is noted that the vertebrae become wedge-shaped, so that the normal dorsal kyphosis increases to a pathological level (AU)