[Revision surgery of anterior cruciate ligament plasty]. / Cirugía de revisión de plastía de ligamento cruzado anterior.

INTRODUCTION: anterior cruciate ligament injuries (ACL) continue increasing in frecuency in the general population and sportmen who practice soccer and american football where we can locate 53% of the total of cases, the annual incidence is 70 per 100,000 persons. The incidence of this injuries has being increasing in women probably of the increase of the participation in such sports. OBJECTIVE: to document the causes of anterior cruciate ligament (ACL) plasty failure, as well as the diagnosis, surgical technique, and postoperative care of a revision ACL plasty surgery. MATERIAL AND METHODS: a search for relevant information, original research articles, clinical trials, and reviews in indexed journals was performed. RESULTS: anterior cruciate ligament injuries continue to increase among the general population and athletes who play soccer and American soccer mainly, in this population group we found 53% of the total cases. The gold standard for treatment is arthroscopic reconstruction of the ligament. ACL reconstruction surgery has good results, with an estimated 75-90% success rate. Long-term failures of anterior cruciate ligament repair represent 5-25%. Among the factors associated with this failure are technical errors, traumatic antecedents, biological factors, among others. CONCLUSIONS: in ACL revision surgery good results can be achieved with respect to graft stability, return to play and functional stability of the knee, but the results are generally inferior to those of primary ACL reconstruction.

INTRODUCCIÓN: las lesiones del ligamento cruzado anterior (LCA) continúan en aumento entre la población general y deportistas que practican fútbol soccer y americano en donde se encuentra 53% del total de los casos; la incidencia anual es de 70 por cada 100,000 personas. La incidencia de estas lesiones ha ido en aumento en mujeres, probablemente por el incremento de la participación deportiva. OBJETIVO: documentar las causas de fracaso de plastía de ligamento cruzado anterior (LCA), así como el diagnóstico, técnica quirúrgica, cuidado postquirúrgico de una cirugía de revisión de plastía LCA. MATERIAL Y MÉTODOS: se ha realizado una búsqueda de información relevante, artículos de investigación originales, ensayos clínicos y revisiones en revistas indexadas. RESULTADOS: las lesiones del ligamento cruzado anterior continúan en aumento entre la población general y deportistas que practican futbol soccer y americano principalmente; en este grupo de la población encontramos 53% del total de los casos. El estándar de oro para su tratamiento es la reconstrucción del ligamento por vía artroscópica. La cirugía de reconstrucción de LCA presentan buenos resultados, se estima 75-90% de éxito. Los fracasos a largo plazo de la reparación de ligamento cruzado anterior representan de 5-25%. Dentro de los factores asociados a este fracaso encontramos errores técnicos, antecedentes traumáticos, factores biológicos, entre otros. CONCLUSIONES: en la cirugía de revisión de LCA se pueden lograr buenos resultados con respecto a la estabilidad del injerto, regreso al juego y estabilidad funcional de la rodilla, pero los resultados son generalmente inferiores a los de la reconstrucción primaria del LCA.

Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV.

Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.

Disorder and amino acid composition in proteins: their potential role in the adaptation of extracellular pilins to the acidic media, where Acidithiobacillus thiooxidans grows.

There are few biophysical studies or structural characterizations of the type IV pilin system of extremophile bacteria, such as the acidophilic Acidithiobacillus thiooxidans. We set out to analyze their pili-comprising proteins, pilins, because these extracellular proteins are in constant interaction with protons of the acidic medium in which At. thiooxidans grows. We used the web server Operon Mapper to analyze and identify the cluster codified by the minor pilin of At. thiooxidans. In addition, we carried an in-silico characterization of such pilins using the VL-XT algorithm of PONDR® server. Our results showed that structural disorder prevails more in pilins of At. thiooxidans than in non-acidophilic bacteria. Further computational characterization showed that the pilins of At. thiooxidans are significantly enriched in hydroxy (serine and threonine) and amide (glutamine and asparagine) residues, and significantly reduced in charged residues (aspartic acid, glutamic acid, arginine and lysine). Similar results were obtained when comparing pilins from other Acidithiobacillus and other acidophilic bacteria from another genus versus neutrophilic bacteria, suggesting that these properties are intrinsic to pilins from acidic environments, most likely by maintaining solubility and stability in harsh conditions. These results give guidelines for the application of extracellular proteins of acidophiles in protein engineering.

Scale to measure medical, nursing and midwifery students' engagement in an e-learning histology course / Escala para medir la participación de estudiantes de medicina, enfermería y obstetricia en un curso de histología e-learning

SUMMARY: E-learning courses become increasingly important and relevant in medicine and health sciences over the last decade. However, there are few teaching experiences of e-learning histology courses published in the literature worldwide. Moreover, most of these studies focus on the didactic aspects of the course without exploring student participation. The study presented below aimed to validate a scale to measure student participation in an e-learning histology course. We provide evidence of validity of the instrument based on its internal structure for use with medical, nursing, and midwifery students. The participants in this study were a group of 426 Chilean medical, nursing and midwifery students from a public university who completed the questionnaire in two consecutive semesters (2020-2021). Data from the first group of students were used to perform an exploratory factor analysis (EFA), while data from the second group of participants were used to perform a confirmatory factor analysis (CFA). The three factors identified according to the CFA were: "Habits of online," "Motivation for online learning," and "Interaction of online". After eliminating one of the initial items of the instrument, the scale showed acceptable psychometric properties suggesting that it is a useful instrument to measure students' perception of their participation in e-learning histology courses. The factors identified through the validation of the instrument provide relevant information for teachers and curriculum developers to create and implement different ways of encouraging student participation in e- learning histology courses to support online learning.

Los cursos e-learning han tomado mayor importancia y relevancia durante la ultima década en carreras de medicina y ciencias de la salud. No obstante, existen escasas experiencias docentes de cursos de histologia e-learning publicadas en la literatura mundial. Además, la mayoría de estos estudios se centran en los aspectos didácticos del curso sin explorar la participación de los estudiantes. El estudio que presentamos a continuación tuvo por objetivo validar una escala para medir la participación de los estudiantes en un curso de histología e-learning. Aportamos evidencia de validez del instrumento basada en su estructura interna para su uso con estudiantes de medicina, enfermería y obstetricia. Los participantes de este estudio fueron un grupo de 426 estudiantes chilenos de medicina, enfermería y obstetricia de una universidad pública quienes completaron el cuestionario en dos semestres consecutivos (año 2020-2021). Los datos del primer grupo de estudiantes se utilizaron para realizar un análisis factorial exploratorio (AFE), mientras que los datos del segundo grupo de participantes se utilizaron para realizar un análisis factorial confirmatorio (AFC). Los tres factores identificados según el AFC fueron: "Hábitos de los estudiantes en línea", "Motivación por el aprendizaje en línea", "Interacción de los estudiantes en línea". Luego de la eliminación de uno de los ítems iniciales del instrumento, la escala mostró propiedades psicométricas aceptables sugiriendo que es un instrumento útil para medir la percepción de los estudiantes sobre su participación en cursos de histología en formato e-learning. Los factores identificados mediante la validación del instrumento entregan información relevante para que los profesores y curriculistas desarrollen e implementen diferentes formas de estimular la participación de los estudiantes en cursos de histología e- learning y así apoyar el aprendizaje en formato online.

Effect of Pesticides on Peroxisome Proliferator-Activated Receptors (PPARs) and Their Association with Obesity and Diabetes.

Obesity and diabetes mellitus are considered the most important diseases of the XXI century. Recently, many epidemiological studies have linked exposure to pesticides to the development of obesity and type 2 diabetes mellitus. The role of pesticides and their possible influence on the development of these diseases was investigated by examining the relationship between these compounds and one of the major nuclear receptor families controlling lipid and carbohydrate metabolism: the peroxisome proliferator-activated receptors (PPARs), PPARα, PPARß/δ, and PPARγ; this was possible through in silico, in vitro, and in vivo assays. The present review aims to show the effect of pesticides on PPARs and their contribution to the changes in energy metabolism that enable the development of obesity and type 2 diabetes mellitus.

Análisis de la expresión inmunohistoquímica de OVOL1 como herramienta diagnóstica de invasión en las neoplasias escamosas de la superficie ocular / OVOL1 immunohistochemical expression is a useful tool to diagnose invasion in ocular surface squamous neoplasms

Antecedentes y objetivos OVOL1 es un gen que regula negativamente la transformación mesenquimática, la cual permite a las células epiteliales invadir el estroma. Por otro lado, regula negativamente la c-Myc, que tiene un efecto positivo sobre la proliferación celular. El objetivo de este estudio es evaluar la expresión de OVOL1 y c-Myc en neoplasias escamosas de la superficie ocular (NESO). Pacientes y métodos Estudio de cohorte transversal de 36 muestras que incluían 6 papilomas escamosos, 19 neoplasias intraepiteliales conjuntivales, 6 carcinomas escamosos y 7 conjuntivas normales, que fueron evaluadas mediante técnica inmunohistoquímica contra OVOL1 y c-Myc. La expresión de ambos marcadores fue analizada usando el H-score (intensidad 1-3 multiplicado por el porcentaje de células positivas) Resultados Un 98 y un 100% de las NESO y un 57 y un 71% de las conjuntivas normales expresaron OVOL1 y c-Myc, respectivamente; sin embargo, el promedio del H-score de OVOL1 y c-Myc fue mayor en las NESO que en las conjuntivas normales (p=0,0001 en ambos). Dentro de las NESO, OVOL1 demostró un H-score mayor en las neoplasias intraepiteliales conjuntivales y los papilomas, en comparación con el carcinoma escamoso (p<0,01). c-Myc no mostró diferencias entre los grupos de NESO. Un H-score menor de 35 diferencia un carcinoma escamoso de los otros grupos de NESO con una sensibilidad del 83,3% y una especificidad del 100%. Conclusiones La expresión de OVOL1 es útil para diferenciar un carcinoma escamoso de una neoplasia intraepitelial conjuntival y un papiloma. OVOL1 podría jugar un rol en la capacidad de invasión de las neoplasias escamosas y lo ubica como un potencial blanco terapéutico (AU)

Background and objectives OVOL1 is a gene that negatively regulates mesenchymal transformation, which allows epithelial cells to invade the stroma. On the other hand, it negatively regulates c-Myc, which has a positive effect on cell proliferation. The aim of this study is to evaluate the expression of OVOL1 and c-Myc in ocular surface squamous neoplasia (OSSN). Patients and methods Cross-sectional cohort study of 36 samples including 6 squamous papillomas, 19 conjunctival intraepithelial neoplasms, 6 squamous carcinomas and 7 normal conjunctivae were evaluated using immunohistochemistry against OVOL1 and c-Myc. The expression of both markers was analysed using the H-score (intensity 1-3 multiplied by the percentage of positive cells). Results Percentages of 98 and 100 of the OSSN, and 57 and 71% of the normal conjunctivae expressed OVOL1 and c-Myc respectively, however, the mean H-score of OVOL1 and c-Myc was higher in the OSSN than in normal conjunctivae group (P=.0001 in both). Within the OSSN, OVOL1 demonstrated a higher H-score in the conjunctival intraepithelial neoplasms and papilloma, compared to the squamous carcinoma (P<.01) group. c-Myc did not show differences between the OSSN groups. An H-score lower than 35 differentiates a squamous cell carcinoma from other OSSN lesions with a sensitivity of 83.3% and a specificity of 100%. Conclusions The expression of OVOL1 is a useful tool to differentiate between a squamous carcinoma of conjunctival intraepithelial neoplasms and papilloma. OVOL1 could play a role in the invasiveness of squamous neoplasms and places it as a potential therapeutic target (AU)

OVOL1 immunohistochemical expression is a useful tool to diagnose invasion in ocular surface squamous neoplasms.

BACKGROUND AND OBJECTIVES: OVOL1 is a gene that negatively regulates mesenchymal transformation, which allows epithelial cells to invade the stroma. On the other hand, it negatively regulates c-Myc, which has a positive effect on cell proliferation. The aim of this study is to evaluate the expression of OVOL1 and c-Myc in ocular surface squamous neoplasia (OSSN). PATIENTS AND METHODS: Cross-sectional cohort study of 36 samples including 6 squamous papillomas, 19 conjunctival intraepithelial neoplasms, 6 squamous carcinomas and 7 normal conjunctivae were evaluated using immunohistochemistry against OVOL1 and c-Myc. The expression of both markers was analysed using the H-score (intensity 1-3 multiplied by the percentage of positive cells). RESULTS: Percentages of 98 and 100 of the OSSN, and 57 and 71% of the normal conjunctivae expressed OVOL1 and c-Myc respectively, however, the mean H-score of OVOL1 and c-Myc was higher in the OSSN than in normal conjunctivae group (P=0.0001 in both). Within the OSSN, OVOL1 demonstrated a higher H-score in the conjunctival intraepithelial neoplasms and papilloma, compared to the squamous carcinoma (P<0.01) group. c-Myc did not show differences between the OSSN groups. An H-score lower than 35 differentiates a squamous cell carcinoma from other OSSN lesions with a sensitivity of 83.3% and a specificity of 100%. CONCLUSIONS: The expression of OVOL1 is a useful tool to differentiate between a squamous carcinoma of conjunctival intraepithelial neoplasms and papilloma. OVOL1 could play a role in the invasiveness of squamous neoplasms and places it as a potential therapeutic target.

Techniques for bone assessment and characterization: porcine hard palate case study.

The hard palate plate has an important structural function that separates the nasal cavity and the nasopharynx. Incomplete regeneration of palatal fistulae in children with a cleft palate deformity after primary palatoplasty is a relatively common complication. To date, the information about the physicochemical bone features of this region is deficient, due to the low availability of human samples. Swine and human bone share anatomical similarities. Specifically, pig bones are widely used as experimental animal models in dental, orthopedic, or surgical techniques. The aim of this study was to show different techniques to evaluate and characterize alternative properties of pig hard palate bone, compared to commercial hydroxyapatite, one of the most used biomaterials for bone tissue regeneration. Chemical analyses by Energy dispersive spectroscopy (EDS) and X-ray fluorescence (XRF) showed calcium and phosphate ions as the main constituents of bone, while magnesium, iron, sodium, potassium, and zinc ions were minor constituents. The calcium phosphate molar ratio (Ca/P) in the bone was low (1.1 ± 0.2) due to the very young specimen sample used. The FTIR spectrum shows the presence of phosphates ions (PO4 3-) and the main characteristics of collagen type I. The XRD results showed that the hard palate bone has a mixture of calcium, octacalcium dihydrogen phosphate (OCP), and apatite, where OCP is the predominant phase. Besides, this research demonstrated that the young bone has low crystallinity and small crystal size compared with commercial hydroxyapatite (HA). The palatine process of maxilla density and porosity data reported, suggest that the palate bone is getting closer to the compact bone with a 52.78 ± 2.91% porosity and their mechanical properties depend on the preparation conditions and the area of the bone analyzed.

Diseño y fabricación de modelos impresos en 3D como complemento para las clases prácticas de histología médica / Design and manufacturing of 3D printed models as a complement for medical histology practical classes

RESUMEN: Tradicionalmente, la Histología se ha apoyado del análisis de preparaciones histológicas a través del microscopio para su enseñanza. En este sentido, uno de los principales obstáculos que enfrentan los estudiantes al analizar los tejidos, es extrapolar una imagen bidimensional a una estructura tridimensional (3D). La impresión 3D permite subsanar esta limitación, haciendo posible fabricar material docente, con las características requeridas con un alto grado de detalle y bajo costo. El objetivo de este trabajo fue diseñar y fabricar modelos impresos en 3D como complemento para las clases prácticas de Histología Médica. Se fabricaron modelos impresos en 3D de la ultraestructura de la barrera de filtración glomerular (BFG) en su estado normal y síndrome nefrótico. Además, se fabricó un modelo de la capa muscular del esófago humano dando énfasis a la disposición helicoidal de sus fibras musculares. Los modelos de epidermis permitieron identificar sus distintos estratos: estrato córneo, estrato granuloso, estrato espinoso, y estrato basal. Dentro los beneficios derivados de la impresión de modelos en 3D podemos destacar el bajo costo económico de su fabricación, alta reproducibilidad, bioseguridad, y potencial para favorecer el aprendizaje y la enseñanza de la Histología. No obstante, es necesario analizar la percepción y beneficio sobre el aprendizaje de los estudiantes derivados de la aplicación de los modelos mediante técnicas de evaluación cuantitativas y cualitativas.

SUMMARY: Traditionally, Histology has relied on the analysis of histological slides through the microscope for its teaching. In this sense, one of the main obstacles faced by students when analyzing tissues is to extrapolate a two-dimensional image to a three-dimensional (3D) structure. 3D printing makes it possible to overcome this limitation, making it possible to manufacture teaching material with the required characteristics with a high degree of detail and low cost. The objective of this work was to design and manufacture 3D printed models as a complement for the practical classes of Medical Histology. 3D printed models of the ultrastructure of the glomerular filtration barrier (GFB) in its normal state and nephrotic syndrome were fabricated. In addition, a model of the muscular layer of the human esophagus was fabricated emphasizing the helical arrangement of its muscle fibers. The epidermis models allowed the identification of its different layers: stratum corneum, stratum granulosum, stratum spinosum, and stratum basale. Among the benefits derived from 3D printing of models, we can highlight the low economic cost of manufacturing, biosafety and potential to favor the learning and teaching of Histology. However, it is necessary to analyze the perception and benefit on student learning derived from the application of the models by means of quantitative and qualitative evaluation techniques.

Particle/wall electroviscous effects at the micron scale: comparison between experiments, analytical and numerical models.

We report a experimental study of the motion of 1 µm single particles interacting with functionalized walls at low and moderate ionic strengths conditions. The 3D particle's trajectories were obtained by analyzing the diffracted particle images (point spread function). The studied particle/wall systems include negatively charged particles interacting with bare glass, glass covered with polyelectrolytes and glass covered with a lipid monolayer. In the low salt regime (pure water) we observed a retardation effect of the short-time diffusion coefficients when the particle interacts with a negatively charged wall; this effect is more severe in the perpendicular than in the lateral component. The decrease of the diffusion as a function of the particle-wall distancehwas similar regardless the origin of the negative charge at the wall. When surface charge was screened or salt was added to the medium (10 mM), the diffusivity curves recover the classical hydrodynamic behavior. Electroviscous theory based on the thin electrical double layer (EDL) approximation reproduces the experimental data except for smallh. On the other hand, 2D numerical solutions of the electrokinetic equations showed good qualitative agreement with experiments. The numerical model also showed that the hydrodynamic and Maxwellian part of the electroviscous total drag tend to zero ash→ 0 and how this is linked with the merging of both EDL's at close proximity.

Frustules of Amphora sp. as a photonic crystal with photoluminescent CdS nanoparticles.

Diatom frustules have species-specific patterns of pores, striae, pores, and nanopores, periodically arranged on its silica surface, as sets of cavities that modify the vacuum electromagnetic density of states. Therefore, frustules may be considered photonic crystals; the interaction with light-emitting sources inside the pores may potentially result in enhancement or inhibition of their spontaneous radiative emission rate and frequencies. In this work, we studied the photoluminescence of cadmium sulfide nanoparticles (CdS-NP) deposited inside frustule cavities that conveyed evidence of cavity-NP interaction. We synthesized CdS-NP, a semiconductor compound achieving quantum dots small enough to impose confinement effects to the electronic states. CdS-NP and their clusters were physiosorbed onto the surface, striae, and predominantly inside the pores of the cleansed frustules of Amphora sp. A broad peak with a maximum intensity at 437 nm (2.84 eV) was recorded after excitation with a 375 nm light source, showing a large blue shift and signal amplification of the CdS-NP photoluminescence when these were embedded inside the pores of the silica frustule. Using the Brus equation, we estimated a NP size of 4.1 ± 0.2 nm for the CdS-NP snuggly packed inside the smaller pores of the frustule, of 10 ± 0.7 nm in average diameter, The emission Purcell enhancement factor for an emitting atom in a cavity was calculated. The obtained Q factor (c. 5) was smaller than typical Q factors for designed semiconductor cavities of similar dimensions, an expected situation if it is assumed that the pores are open-ended cavities.

La importancia de la anatomía y su enseñanza entorno al razonamiento clínico en la carrera de medicina: una revisión bibliográfica / The importance of anatomy and its teaching about clinical reasoning in the medical career: a literature review

La anatomía humana es la ciencia que estudia la estructura y forma de los componentes del cuerpo humano desde una perspectiva macroscópica. Esta ciencia presenta diferentes disciplinas, entre ellas, la anatomía clínica, que brinda un conjunto de conocimientos anatómicos fundamentales para el ejercicio de la medicina. No obstante, en la actualidad la enseñanza de la anatomía carece de las herramientas y orientación pedagógica necesarias que permitan que los estudiantes adquieran los conocimientos anatómicos necesarios para el ejercicio de su futura carrera médica. En consideración a esta problemática, se relatan algunas experiencias didácticas que describen la integración de competencias clínicas a la enseñanza de la anatomía, tales como elementos del razonamiento clínico y herramientas de uso constante para el diagnóstico y manejo de pacientes. Finalmente, consideramos que la educación médica debe orientarse a obtener conocimiento anatómico y desarrollar la habilidad de aplicar ese conocimiento en el ámbito clínico, bajo el uso de herramientas que estimulen ese dominio, así como también incentiven el desenvolvimiento médico correcto.

Human anatomy is the science that studies the structure and form of the components of the human body. This science presents different disciplines, among them, clinical anatomy, which provides a set of fundamental anatomical knowledge for the practice of medicine. However, at present, the teaching of anatomy lacks the necessary tools and pedagogical orientation that would allow students to acquire the anatomical knowledge useful for their future medical career. In consideration of this problem, some experiences are reported that describe the integration of clinical competencies to anatomy teaching, such as elements of clinical reasoning and tools of constant use for diagnosis and patient management. Finally, we consider that medical education must be oriented to obtain anatomical knowledge and to develop the ability to apply that knowledge in the clinical environment, under the use of tools that stimulate that domain, as well as to encourage the correct medical development.

[Early congenital syphilis, inadequate screening. Case report]. / Sífilis congénita temprana, cribado insuficiente. Reporte de un caso.

Background: Congenital syphilis is still a problem for developing countries, despite the screening options and low cost treatment. Clinical case: 23-day-old male patient with copper colored macules and scaling in palms and soles, as well as hepatomegaly. It was reported a negative TORCH test with VDRL of 1:512 and positive FTA ABS. As maternal history, patient had a 21 year old mother with negative VDRL at 12 weeks pregnant. Despite maternal history, with positive VDRL and FTA ABS, besides the clinical triad, it was diagnosed congenital syphilis. Conclusion: Factors that most influence failing in the prevention of congenital syphilis are inadequate prenatal care, misinterpreting diagnostic tests and not establishing monitoring programs. It is necessary to carry out VDRL tests twice during pregnancy to women who have a risk factor.

Introducción: la sífilis congénita continúa siendo un problema para los países emergentes, a pesar de las opciones de cribado y un tratamiento de bajo costo. Caso clínico: paciente de sexo masculino de 23 días de vida con máculas de color cobrizo con descamación en región palmoplantar y hepatomegalia. Se reportó un TORCH negativo con prueba serológica para la sífilis (VDRL) de 1:512 en el neonato y FTA-ABS positivo. El paciente tenía antecedente de ser hijo de madre de 21 años de edad, con VDRL negativo en el primer trimestre de embarazo. A pesar del antecedente materno, con una VDRL y un FTA-ABS positivo, además de la triada clínica, se hizo el diagnóstico de sífilis congénita. Conclusiones: los factores que más influyen en el fracaso de la prevención de la sífilis congénita son la atención prenatal inadecuada, el fracaso en la interpretación de las pruebas de diagnóstico y en los programas de monitoreo. Es necesario tomar VDRL en dos ocasiones durante la gestación o seriado por trimestre a las madres que presenten algún factor de riesgo.

Neonatal outcomes associated with maternal recto-vaginal colonization with extended-spectrum ß-lactamase producing Enterobacteriaceae in Nigeria: a prospective, cross-sectional study.

OBJECTIVES: The objective of this study was to assess the prevalence of maternal recto-vaginal extended-spectrum ß-lactamase producing Enterobacteriacea (ESBL-E) colonization, identify risk factors for maternal and neonatal ESBL-E colonization, and subsequent impact on neonatal mortality. METHODS: A prospective, cross-sectional study was conducted at the University of Abuja Teaching Hospital from April 2016 to May 2017. Maternal-neonatal pairs were screened for ESBL-E exposure at time of delivery. Neonatal mortality was assessed at 28 days. RESULTS: A total of 1161 singleton deliveries were evaluated. In total, 9.7% (113/1161) of mothers and 4.3% (50/1161) of infants had ESBL-E-positive cultures at delivery. Maternal antibiotic exposure was associated with ESBL-E recto-vaginal colonization (18.6% (21/113) vs. 8.4% (88/1048), p < 0.001)). Maternal ESBL-E colonization (adjusted odds ratio (AOR) 14.85; 95% CI 7.83-28.15) and vaginal delivery (AOR 6.35; 95% CI 2.63-17.1) were identified as a risk factor for positive ESBL-E neonatal surface cultures. Neonatal positive ESBL-E surface cultures were a risk factor for neonatal mortality (stillbirths included, AOR 4.84; 95% CI 1.44-16.31). The finding that maternal ESBL-E recto-vaginal colonization appeared protective in regards to neonatal mortality (AOR 0.22; 95% CI .06-0.75) requires further evaluation. CONCLUSIONS: Maternal ESBL-E recto-vaginal colonization is an independent risk factor for neonatal ESBL-E colonization and neonates with positive ESBL-E surface cultures were identified as having increased risk of neonatal mortality.

Electrochemical monitoring of Acidithiobacillus thiooxidans biofilm formation on graphite surface with elemental sulfur.

Inorganic wastewaters and sediments from the mining industry and mineral bioleaching processes have not been fully explored in bioelectrochemical systems (BES). Knowledge of interfacial changes due to biofilm evolution under acidic conditions may improve applications in electrochemical processes, specifically those related to sulfur compounds. Biofilm evolution of Acidithiobacillus thiooxidans on a graphite plate was monitored by electrochemical techniques, using the graphite plate as biofilm support and elemental sulfur as the only energy source. Even though the elemental sulfur was in suspension, S0 particles adhered to the graphite surface favoring biofilm development. The biofilms grown at different incubation times (without electric perturbation) were characterized in a classical three electrode electrochemical cell (sulfur and bacteria free culture medium) by non-invasive electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The biofilm structure was confirmed by Environmental Scanning Electrode Microscopy, while the relative fractions of exopolysaccharides and extracellular hydrophobic compounds at different incubation times were evaluated by Confocal Laser Scanning Microscopy. The experimental conditions chosen in this work allowed the EIS monitoring of the biofilm growth as well as the modification of Extracellular Polymeric Substances (EPS) composition (hydrophobic/ exopolysaccharides EPS ratio). This strategy could be useful to control biofilms for BES operation under acidic conditions.

Sequence analysis and confirmation of the type IV pili-associated proteins PilY1, PilW and PilV in Acidithiobacillus thiooxidans.

Acidithiobacillus thiooxidans is an acidophilic chemolithoautotrophic bacterium widely used in the mining industry due to its metabolic sulfur-oxidizing capability. The biooxidation of sulfide minerals is enhanced through the attachment of At. thiooxidans cells to the mineral surface. The Type IV pili (TfP) of At. thiooxidans may play an important role in the bacteria attachment since TfP play a key adhesive role in the attachment and colonization of different surfaces. In this work, we report for the first time the mRNA sequence of three TfP proteins from At. thiooxidans, the adhesin protein PilY1 and the TfP pilins PilW and PilV. The nucleotide sequences of these TfP proteins show changes in some nucleotide positions with respect to the corresponding annotated sequences. The bioinformatic analyses and 3D-modeling of protein structures sustain their classification as TfP proteins, as structural homologs of the corresponding proteins of Ps. aeruginosa, results that sustain the role of PilY1, PilW and PilV in pili assembly. Also, that PilY1 comprises the conserved Neisseria-PilC (superfamily) domain of the tip-associated adhesin, while PilW of the superfamily of putative TfP assembly proteins and PilV belongs to the superfamily of TfP assembly protein. In addition, the analyses suggested the presence of specific functional domains involved in adhesion, energy transduction and signaling functions. The phylogenetic analysis indicated that the PilY1 of Acidithiobacillus genus forms a cohesive group linked with iron- and/or sulfur-oxidizing microorganisms from acid mine drainage or mine tailings.

Different radiation dose rate as radioprotection and the cross effect with chromium using in vivo somatic cells of Drosophila.

Ionizing radiation plays a key role in the adaptation of an individual organism to environmental pollution, at the same time, it has biological effects that depend on radiation intensity or dose rate (DR). Although the effect of DR has been studied in vitro, the phenomenon known as the inverse effect of DR, which indicates as it decreases that the induction of damage is greater, has not been widely studied in vivo. The present study is aimed to test 0.5 and 1 Gy in somatic cells of the wing of D. melanogaster, administered at 5.4 or 34.3 Gy/h and from 0.037 to 0.3 mM of CrO3 as conditioning treatment. No changes were found in larva-to-adult viability. A protective as well as a cross effect of pre-exposure to different DR and CrO3 concentrations against genetic damage induced by 20 Gy or 1 mM CrO3 was evident.