Radiación y medios de contraste en embarazo y lactancia: lo que el clínico necesita saber / Radiation and contrast media in pregnancy and lactation: what the clinician needs to know

Introducción: el uso de técnicas de imagenología es habitual e incluso indispensable en algunos procesos diagnósticos. Sin embargo, su indicación en mujeres embarazadas y en período de lactancia es controvertida. Objetivo: presentar una revisión narrativa sobre los riesgos asociados al uso de imágenes con radiación y medio de contraste en embarazo y periodo de lactancia, con énfasis en las recomendaciones y aplicaciones clínicas que el médico tratante debe tener presente al momento de su indicación. Métodos: se realizó una revisión bibliográfica de la literatura relevante sobre los riesgos y consideraciones especiales del uso de medios de contraste en el embarazo y lactancia. Resultados: los riesgos de la radiación ionizante sobre el feto varían de acuerdo al estadio del embarazo, por lo que la indicación del estudio debe ponderar los riesgos y beneficios. En las dosis clínicas en embarazo y lactancia, el uso de contraste yodado como basados en gadolinio no tienen efectos deletéreos en la salud de la madre ni la del feto. Sin embargo, las sociedades internacionales recomiendan limitar su uso. Conclusión: si bien la indicación de estudios de imagen que utilizan radiación ionizante en el embarazo y lactancia es seguro, el médico clínico debe conocer los posibles riesgos de la radiación ionizante en este grupo de pacientes. Respecto a los medios de contraste, el único efecto adverso reportado es la disfunción tiroidea transitoria en hijos de madres que recibieron medios de contraste yodado.

Introduction: the use of imaging techniques is essential in some diagnostic processes. However, its indication in pregnant and lac-tating women is controversial. Objective: To present a narrative review of the risks associated with using images with radiation and contrast media in pregnancy and lactation. Emphasis will be put on the recommendations and clinical applications that the physician must consider before its indication. Methods: a bibliographic review of the relevant literature on the risks and special considerations of contrast media in pregnancy and lactation was performed. Results: the risks of ionising radiation on the fetus vary according to the stage of pregnancy, so the indication of the study must balance the risks and benefits. The use of iodinated and gadolinium-based con-trast agents in clinical doses in pregnancy and lactation has no effects on the health of the mother or the fetus. However, international societies recommend limiting its use. Conclusion: Although the indication for imaging studies using ionising radiation in pregnancy and lactation is safe, the clinician must be aware of the possible risks of ionising radiation in this group of patients. The only adverse effect reported is transient thyroid dysfunction in children of mothers who received iodinated contrast media.

Elaboración de un simulador de trauma torácico a partir de un torso cadavérico utilizando tecnología de imágenes digitales e impresión 3D / Elaboration of a thoracic trauma surgery simulation model from a cadaveric human torso incorporating digital image technology and 3D printing

Resumen Objetivo: Presentar la elaboración de un simulador de trauma torácico de alta fidelidad elaborado mediante modelamiento e impresión 3D a partir de un torso humano cadavérico. Materiales y Método: Estudio descriptivo del desarrollo de un simulador de trauma torácico utilizando metodología centrada en el prototipado y la iteración basada en testeos. Resultados: Se elaboró un simulador reutilizable mediante la digitalización de un torso cadavérico utilizando tomografía computada. Se realizó una reconstrucción digital del torso diseñando los planos subcutáneos, muscular y óseo en base a las imágenes del paciente pre y postoracotomía anterolateral. Utilizando impresión 3D y materiales sintéticos, se elaboró la caja torácica para luego instalar un corazón y pulmón porcino ventilado y perfundido. Los parches de la toracotomía son reemplazables y de bajo costo. En conjunto, este simulador permite el entrenamiento en manejo de lesiones traumáticas cardiacas y pulmonares de alta fidelidad. Conclusión: La metodología presentada permite la creación de un modelo para el entrenamiento y evaluación de habilidades quirúrgicas en trauma torácico. Los elementos principales del simulador son reutilizables y permiten mantener bajos los costos del entrenamiento.

Aim: To describe the design and creation of a high-fidelity thoracic trauma surgery simulation model incorporating 3D printing technology using a cadaveric human torso as a model. Materials and Method: This is a descriptive study that aims to illustrate the creation process of a thoracic trauma surgery simulation model throughout the incorporation of prototypes and dynamic iteration technologies. Results: A high-fidelity reusable thoracic trauma surgery simulation model was created from the digitalization of a cadaveric torso using a computed tomography scan. Throughout digital reconstruction tools, the subcutaneous, muscular, and skeletal structures were modeled from images obtained before and after an anterolateral thoracotomy. Using 3D printing and synthetic materials, a high-fidelity thoracic cavity was built so that perfused and ventilated porcine heart and lungs could be placed. A thoracotomy patch for the anterolateral thoracotomy was designed in a reusable and low-cost fashion. This simulation model is suitable for high fidelity training in the surgical management of cardiopulmonary traumatic injuries. Conclusion: The described methodology allowed the creation of a simulation model for training and assessment of surgical skills in thoracic trauma. The main components of the simulation model are made from reusable materials, broadening access to low-cost, high fidelity training.

Medios de contraste intravascular en tomografía computada y resonancia magnética: lo que el clínico necesita saber / Intravascular contrast media in computed tomography and magnetic resonance imaging: what the clinician needs to know

Introducción: los medios de contraste en radiología se utilizan para mejorar la visibilidad de los tejidos normales y patológicos, lo que permite distinguirlos entre sí mediante la modificación de las características de imagen de los tejidos. Permite no solo una mejor evaluación morfológica de las lesiones, sino también una evaluación cinética funcional y de contraste. Objetivos: presentar una revisión actualizada sobre los medios de contraste intravascular en radiología, con énfasis en los conceptos que el médico clínico no radiólogo debe tener presente al momento de su indicación. Métodos: se realizó una revisión bibliográfica de literatura radiológica relevante sobre medios de contraste intravascular: clasificación, indicaciones, contraindicaciones y precauciones que debe adoptar el médico clínico. Resultados: aunque los medios de contraste en radiología tienen un excelente perfil de seguridad, su uso no está exento de riesgos y debe basarse en criterios apropiados después de una evaluación clínica exhaustiva, ponderando riesgos y beneficios para cada paciente individual. Conclusión: la comunicación entre médicos tratantes, nefrólogos y radiólogos es funda-mental para evaluar casos clínicos complejos o que requieran consideraciones especiales al momento de indicar la administración de un medio de contraste intravascular.

Introduction: Imaging contrast media are used to enhance the visibility of normal and pathologic tissues, allowing distinction of one another by modifying tissue imaging characteristics. This allows both enhanced morphologic assessment of lesions and also contrast kinetics evaluation. Objectives: To present an updated review on intravascular imaging contrast media. Emphasis will be put on useful concepts that general physicians must take into account when indicating contrast-enhanced imaging studies.Methodology: A bibliographic review of relevant imaging literature on intravascular contrast media was performed: classification, appropriate indications, contraindications, and tips for proper use by the general physician. Results: Although imaging contrast media have an excellent safety profile, its use is not risk-free and must be based on appropriateness criteria applied after a thorough clinical evaluation, balancing the risks and benefits for each patient. In particular, intravascular contrast media, such as those based on iodine for computed tomography and gadolinium chelates for magnetic resonance imaging, must be used with caution. Conclusion: Effective communication between radiologists and referring physicians is key in the evaluation of complex cases that require protocol adjustments when considering the use of intravascular contrast media for imaging studies.

Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

Background: Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS), suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results: We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions: These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.

Leiomiomatosis intravenosa de origen pelviano con extensión intracardiaca: Reporte de dos casos / Pelvic intravenous leiomyomatosis with intracardiac extension: Report of two cases

Background: symptoms predominate. Diagnosis is based on clinical findings and appropriate imaging. We report two females, aged 35 and 51 years. One of them presented with a pelvic mass and dyspnea, the other patient had severe cardiac failure on admission. Computed axial tomography scan allowed an accurate preoperative diagnosis on both patients. Successful one stage resection of the tumor was performed under cardiopulmonary bypass. Both patients are asymptomatic on follow up at 6 months and 25 years.

Medición volumétrica de grasa visceral abdominal con RM y su relación con elastografía hepática en una población diabética / Volumetric measurement of abdominal visceral fat by MRI and its relation to transient elastography in a diabetic population

Background. Increase in visceral fat is associated to the development of fatty liver and liver fibrosis. Hepatic elastography is a novel noninvasive method for assessing liver fibrosis. Objective. To evaluate the relationship between visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT) as measured by Magnetic Resonance Imaging (MRI) and transient elastography (TrE) values using ARFI (Acoustic Radiation Force Impulse) in type 2 Diabetic Mellitus patients (DM2). Methods. We included 20 DM2 patients (mean age: 62 years, range: 55-75, mean weight: 77.8 kg, range: 61.5-97). Patients underwent an MRI study in a Philips Intera 1.5T scanner. MR imaging protocol included a spectral excitation sequence centered on the fat peak. The sequence included 32 cross sections, 7mm thick, from the diaphragmatic cupula to the inferior border of the kidney. VAT was measured by using the semiautomatic Image J software. Each patient underwent a hepatic elastograpy (HE); 10 ARFI measurements were performed in the right hepatic lobe. Finally, a statistical analysis was performed by applying Pearson correlation between abdominal fat volumes and ARFI scores Results. Mean VAT was 2472 +/- 861 cc, (1173-4020 cc), whilst the mean ARFI was 1.62 ± 0.8 m/s, (0.8-3.4 m/s). Correlations obtained were r=0.08 between VAT and ARFI (p=0.72); 0.13 between SAT and ARFI (p=0.57), and -0.06 between (VAT+SAT) and ARFI (p=0.77). By subdividing the sample universe, we observed that the group with ARFI scores greater than 1.6 m/s (7 patients) had a correlation of 0.63 between VAT and ARFI (p=0.12); of 0.66 between SAT and ARFI (p=0.10), and of 0.94 between VAT+SAT and ARFI (p=0.001). In the subgroup with ARFI values inferior to 1.6 m/s (13 patients), the correlation was of 0.11 between VAT and ARFI (p=0.71); of 0.26 between SAT and ARFI (p=0.38), and of 0.32 between ( VAT+SAT) and ARFI (p=0.28). When adjusted for gender, ARFI scores greater than.

Introducción. La acumulación de grasa visceral se asocia al desarrollo de enfermedad hepática. La elastografía hepática es un método novedoso no invasivo para evaluar fibrosis hepática. Objetivo. Evaluar la relación entre el volumen de tejido adiposo visceral (VAT), volumen de tejido adiposo subcutáneo (SAT) medido por resonancia magnética (RM), con índices de elastografía hepática (EH) utilizando ARFI (fuerza de impulso de radiación acústica) en pacientes con Diabetes Mellitus tipo 2 (DM2). Métodos. Fueron incluidos 20 pacientes (edad promedio: 62 años, rango: 55-75 años, peso promedio: 77,8 kg, rango: 61,5-97 kg) con DM2. Los pacientes se sometieron a un examen de RM en un resonador Philips Intera 1.5T. Al protocolo de RM se agregó una secuencia de excitación espectral centrada en el peak de grasa. La secuencia incluyó 32 cortes transversales, grosor 7mm, desde la cúpula diafragmática hasta el borde inferior renal. En las imágenes se midió VAT utilizando el software Image J (freeware). En cada paciente se realizó una EH, utilizando ARFI con 10 medidas en lóbulo hepático derecho. Finalmente, se realizó un análisis estadístico a través de la correlación de Pearson entre los volúmenes de grasa abdominal y ARFI. Resultados. El promedio de VAT fue 2472 +/- 861 cc, (1173-4020 cc), el promedio de ARFI fue 1,62 ± 0,8 m/s, (0,8-3,4 m/s). Se obtuvieron correlaciones de r=-0,08 entre VAT y ARFI (p=0,72), de 0,13 entre SAT y ARFI (p=0,57), y de -0,06 entre (VAT+SAT) con ARFI (p=0,77). Subdividiendo el universo muestral, se encontró que el grupo con ARFI mayor que 1,6 m/s (7 pacientes) obtuvo una correlación de 0,63 entre VAT y ARFI (p=0,12), de 0,66 entre SAT y ARFI (p=0,10), y de 0,94 entre (VAT+SAT) con ARFI (p=0,001). En el subgrupo con ARFI inferior a 1,6 m/s (13 pacientes) la correlación fue 0,11 entre VAT y ARFI (p=0,71), de 0,26 entre SAT y ARFI (p=0,38), y de 0,32 entre (VAT+SAT) y ARFI (p=0,28).

Inhibition of attachment of some fouling diatoms and settlement of Ulva lactuca zoospores by film-forming bacterium and their extracellular products isolated from biofouled substrata in Northern Chile

The biofouling of surfaces submerged in the marine environment includes primary colonization of the substrate by microorganisms including bacteria, microalgae, and microscopic reproductive propagules of macroorganisms such as algal zoospores. The present study reports the evaluation of the inhibitory potential of biofilms and extracellular products (EP) of the indigenous bacterium Alteromonas sp strain Ni1-LEM on the settlement of marine biofouling such as: (i) eight marine benthic diatoms and (ii) zoospores of the alga Ulva lactuca, as well as the germination of these zoospores and was compared with reference strains with proven antifouling properties, Halomonas marina (ATCC 25374) and Pseudoalteromonas tunicata. Highest antifouling activity was found for the indigenous strain. In attempts to better define the chemical nature of the antifouling substance in the EP of the Alteromonas sp strain Ni1-LEM, the culture filtrates were tested for activity after heat treatment, enzymatic treatments, dialysis through semipermeable membranes, and separation into polar (aqueous) and non-polar (organic) fractions. The results suggested that the antifouling substance in the culture filtrates to be protein or peptide in nature, thermostable, hydrophilic, and equal to or greater than 3500 daltons in molecular size. Antifouling substances from bacteria may lead to the development of novel antifouling agents in the future.

The inhibitory effect of biofilms produced by wild bacterial isolates to the larval settlement of the fouling ascidia Ciona intestinalis and Pyura praeputialis

Marine biofouling is a present and potentially increasing future problem at molluscan culture centres. The problem is highly variable, exists on different scales, and its negative impact on cultured organisms and related economic losses at these centres has not been significantly controlled. One approach to fouling control has been the incorporation of natural substances into anti-fouling paints which inhibit the settlement of common fouling organisms. The main objective of the present study was the isolation of naturally occurring substances from marine bacteria which were inhibitory to the settlement of Ciona intestinalis and Pyura praeputialis, two tunicate species causing serious fouling problems in scallop culture systems in Chile. Numerous bacterial strains were isolated from microfouling on natural and artificial substrates submerged in the sea; of 73 strains isolated, 20 percent demonstrated inhibitory effects on the settlement of the larvae of the above cited tunicates. The inhibitory substances produced by the active bacteria were extracellular, and could be incorporated in an inert matrix (PhytagelTM) without losing their inhibitory properties. Some properties of the inhibitory substance isolated from bacterial strain Clon Nil-LEM (Alteromonas sp) included thermostability, MW < 3500 Da, peptidase lability (against C. intestinalis), and undiminished inhibitory activity when incorporated in the inert matrix.

Characterization by PCR of Vibrio parahaemolyticus isolates collected during the 1997-1998 Chilean outbreak

Between November 1997 and April 1998, several human gastroenteritis cases were reported in Antofagasta, a city in the north of Chile. This outbreak was associated with the consumption of shellfish, and the etiologic agent responsible was identified as Vibrio parahaemolyticus. This was the first report of this bacterium causing an epidemic in Chile. V. parahaemolyticus was the only pathogenic bacterium isolated from patient stools and from shellfish samples. These isolates were analyzed by polymerase chain reaction (PCR) amplification of the pR72H gene, a species-specific sequence. Based on the pR72H gene amplification pattern, at least three different isolates of V. parahaemolyticus were found. Two isolates (named amplicons A and C) generated PCR products of approximately 400 bp and 340 bp respectively, while another type of isolate designated B, did not generate a PCR product, regardless of which method of DNA purification was used. Sequence analysis of the amplicons A and C shows that they have an 80 bp and 183 bp conserved region at the 5' end of the gene. However, both isolates have different sequences at their 3' terminus and are also different from the pR72H sequence originally reported. Using this PCR assay we demonstrated that these three isolates were found in clinical samples as well as in shellfish. The warm seawater caused by the climatological phenomena "El Nino" perhaps favored the geographic dispersion of the bacterium (bacterial bloom) occurring in Antofagasta that occurred during that time of year

Efecto digitalis like de ácidos biliares sobre electrofisiología y contractilidad en corazón de rata / Digitalis like effects of biliary acids on the electrophysiology and contractility of the rat heart

Se ha demostrado efectos cronótropos e inótropos negativos de los ácidos biliares (AB). Sin embargo, se sabe que éstos pueden aumentar la concentración de calcio intracelular, sugiriendo una acción estimulante sobre el corazón. Por esta razón se investigó posibles efectos estimulantes de los AB sobre automatismo y contractilidad cardíaca. En preparaciones sinoatriales con actividad espontánea se estudiaron los efectos de AB sobre la frecuencia sinusal (FS) y en músculos papilares estimulados a frecuencias constantes se analizaron las acciones sobre fuerza contráctil. Los ácidos cólico y taurocólico disminuyeron la FSde forma similar a todas las concentraciones usadas. Se sugiere que el efecto cronótropo negativo es debido, por lo menos en parte, a una disminución de la corriente Isi y a un aumento de la corriente Ik. Sin embargo, no es posible descartar acciones sobre otras corrientes iónicas en especial If. Ambos ácidos tuvieron efecto inótropo positivo que puede deberse a inhibición de la ATPasa sodio-potasio, aunque no es posible descartar la existencia de otros mecanismos. En resumen, lo AB tienen efectos sobre el automatismo del nódulo sinusal y la contractilidad miocárdica que permite considerarlos como agentes digitalis-like