Simplified Models to Assess the Mechanical Performance Parameters of Stents.

Ischemic heart disease remains a leading cause of mortality worldwide, which has promoted extensive therapeutic efforts. Stenting has emerged as the primary intervention, particularly among individuals aged 70 years and older. The geometric specifications of stents must align with various mechanical performance criteria outlined by regulatory agencies such as the Food and Drug Administration (FDA). Finite element method (FEM) analysis and computational fluid dynamics (CFD) serve as essential tools to assess the mechanical performance parameters of stents. However, the growing complexity of the numerical models presents significant challenges. Herein, we propose a method to determine the mechanical performance parameters of stents using a simplified FEM model comprising solid and shell elements. In addition, a baseline model of a stent is developed and validated with experimental data, considering parameters such as foreshortening, radial recoil, radial recoil index, and radial stiffness of stents. The results of the simplified FEM model agree well with the baseline model, decreasing up to 80% in computational time. This method can be employed to design stents with specific mechanical performance parameters that satisfy the requirements of each patient.

Association between fluid overload and mortality in children with sepsis: a systematic review and meta-analysis.

BACKGROUND: Sepsis is one of the main causes of morbidity and mortality worldwide. Fluid resuscitation is among the most common interventions and is associated with fluid overload (FO) in some patients. The objective of this systematic review and meta-analysis was to summarise the available evidence on the association between FO and morbimortality in children with sepsis. METHODS: A systematic search was carried out in PubMed/Medline, Embase, Cochrane and Google Scholar up to December 2022 (PROSPERO 408148), including studies in children with sepsis which reported more than 10% FO 24 hours after admission to intensive care. The risk of bias was assessed using the Newcastle-Ottawa scale. Heterogeneity was assessed using I2, considering it absent if <25% and high if >75%. A sensitivity analysis was run to explore the impact of the methodological quality on the size of the effect. Mantel-Haenszel's model of random effects was used for the analysis. The primary outcome was to determine the risk of mortality associated with FO and the secondary outcomes were the need for mechanical ventilation (MV), multiple organ dysfunction syndrome (MODS) and length of hospital stay associated with FO. RESULTS: A total of 9 studies (2312 patients) were included, all of which were observational. Children with FO had a higher mortality than patients without overload (46% vs 26%; OR 5.06; 95% CI 1.77 to 14.48; p<0.01). We found no association between %FO and the risk of MODS (OR: 0.97; 95% CI 0.13 to 7.12; p=0.98). Children with FO required MV more often (83% vs 47%; OR: 4.78; 95% CI 2.51 to 9.11; p<0.01) and had a longer hospital stay (8 days (RIQ 6.5-13.2) vs 7 days (RIQ 6.1-11.5); p<0.01). CONCLUSION: In children with sepsis, more than 10% FO 24 hours after intensive care admission is associated with higher mortality, the need for MV and length of hospital stay.

Alteración del sueño y uso de pantallas en distintas etapas de cuarentena en provincias de la Patagonia argentina / Sleep disturbance and use of screens in different stages of quarantine in provinces of Patagonia argentina

Introducción: debido a la pandemia desarrollada por COVID-19, el Gobierno argentino, adoptó ­a partir del 20 de marzo de 2020­ medidas excepcionales de aislamiento social, preventivo y obligatorio (ASPO) o cuarentena, con el fin de proteger la salud pública. En esta etapa se manifestó un mayor uso de pantallas que, en exceso, constituye un factor de riesgo de enfermedades cardiovasculares y alteración en la calidad del sueño. El objetivo de estudio fue estimar el cambio de las horas de sueño y de uso de pantallas antes del inicio del ASPO, en comparación con la tercera y octava semana de cuarentena en personas de 13 a 80 años de la provincia del Neuquén y el Alto Valle Río Negro-Neuquén. Métodos: se realizaron dos Encuestas, en la tercera y octava semana de cuarentena, sobre conductas y hábitos de vida en personas entre 13-80 años. Fueron autoadministradas y enviadas por redes sociales. El muestreo fue aleatorio. Los datos se analizaron usando el paquete estadístico SPSS®. Las encuestas fueron anónimas y confidenciales. Resultados: se obtuvieron 3386 respuestas. De ellas se infirió que la cantidad de horas diarias frente a pantallas y las horas de sueño y el inicio del sueño fueron diferentes por grupos en los períodos precuarentena, y tercera y octava semana de la cuarentena. El grupo de adolescentes mostró mayores diferencias en todas las variables respecto del período precuarentena. La correlación entre las horas de pantalla y las horas de sueño fue baja, en las 3 etapas de la cuarentena. Conclusión: este estudio estimó el cambio de hábitos durante la cuarentena. En ese período se observó mayor cantidad de horas de sueño, un retraso en el tiempo de inicio del sueño y más horas frente a las pantallas; estas diferencias fueron significativas respecto del período precuarentena, y las mayores diferencias se registraron entre los adolescentes. (AU)

Introduction: due to the pandemic developed by COVID 19, the Argentine Government adopted, as of March 20, 2020, exceptional measures of social, preventive and mandatory isolation (ASPO) or quarantine in order to protect public health. In this stage, there was a greater use of screens that in excess, constitutes a risk factor for cardiovascular diseases and alteration in the quality of sleep. Methods: two Surveys were conducted, in the third and eighth week of quarantine, on behaviors and life habits in people between 13-80 years of age. They were self-administered and sent through social networks. The sampling was random. The data were analyzed using the SPSS® statistical package. The surveys were anonymous and confidential. Results: 3386 responses were obtained. It was obtained that the amount of daily hours in front of screens and the hours of sleep and the onset of sleep were different by groups of pre, third and eighth week of quarantine. The adolescent groups howed greater differences in all variables with respect to the pre-quarantine period. The correlation between the hours of screen and the hours of sleep was low, in the 3 stages of quarantine. Conclusion: this study estimated the change in habits during quarantine. In quarantine, longer hours of sleep, a delay in the time of onset of sleep and more hours in front of screens were observed, these differences being significant with respect to the pre-quarantine period, with the greatest differences being established in adolescents. (AU)

Síndrome de vena cava superior en pediatría. Una revisión de la literatura / Superior vena cava syndrome in pediatrics. A review of the literature

Las urgencias oncológicas son un reto para el clínico. El síndrome de vena cava superior es una emergencia hemato-oncológica en pediatría, el cual se define como la obstrucción intrínseca o extrínseca de la vena cava superior. La clínica más frecuente en pediatría es la aparición de circulación colateral, edema en esclavina y cianosis facial. El diagnóstico es clínico y debe hacerse lo menos invasivamente posible y de una manera rápida, para iniciar cuanto antes su manejo. Los linfomas, el uso prolongado de catéter venoso central y la cirugía cardiovascular en cardiopatías congénitas, son las principales etiologías. En algunas ocasiones, puede ser necesario un tratamiento empírico para salvar la vida del paciente, mediante el uso de esteroides y radioterapia. El objetivo del presente artículo es revisar y actualizar los aspectos más importantes sobre la etiología, las manifestaciones clínicas, el diagnóstico y el tratamiento del síndrome de vena cava superior en pediatría

Oncological emergencies are a challenge for the clinician. The superior vena cava syndrome is a hemato-oncological emergency in pediatrics; it is defined as an intrinsic or extrinsic obstruction of the superior vena cava. The most frequent clinical manifestations in children are the appearance of collateral circulation, edema in the body and facial cyanosis. The diagnosis is clinical and should been done as little invasively as possible and without delay to start its management as soon as possible. Lymphomas, prolonged use of a central venous catheter, and cardiovascular surgery in congenital heart disease are the main etiologies. In some cases, empirical treatment may be necessary to save the patient's life, through the use of steroids and radiotherapy. The aim of this article is to review and update the most important aspects of the etiology, clinical manifestations, diagnosis and treatment of the superior vena cava syndrome in pediatrics

Construcción y validación de un instrumento para medir conocimientos de madres y cuidadores sobre alimentación complementaria de infantes / Construction and validation of an instrument to measure knowledge of mothers and caregivers on complementary feeding of infants

INTRODUCCIÓN: La nutrición adecuada durante los primeros dos años de vida es fundamental para el desarrollo pleno del potencial del ser humano. La introducción inadecuada, precoz o tardía de la alimentación complementaria trae consecuencias a corto y largo plazo. La alimentación complementaria depende en gran medida de los conocimientos del cuidador que en los países de Latinoamérica generalmente es la madre. OBJETIVO: construir y validar un instrumento para medir los conocimientos maternos y de cuidadores sobre alimentación complementaria. SUJETOS Y MÉTODO: Estudio de observación. Participaron 80 madres comunitarias y 12 pediatras expertos. Se desarrolló en dos etapas: la creación del instrumento a partir de las 7 fases propuestas por Sampieri, y la validación mediante la evaluación de validez aparente, de constructo, de contenido, consistencia interna y fiabilidad intra-observador. RESULTADOS: Se creó un instrumento autoadministrado que incluyó inicialmente 14 preguntas sobre conocimientos maternos y de cuidadores. Durante la validación de constructo se identificaron 3 dominios y se eliminaron cuatro preguntas. En la validación de contenido, 10 preguntas del instrumento definitivo obtuvieron calificaciones superiores a 9 (en una escala de 0-10) en las características: calidad, vocabulario, relevancia y actualidad. La consistencia interna global del instrumento fue moderada (Alfa de Cronbach: 0,64) y la fiabilidad intra-observador fue aceptable (k: 0,21-0,40) para el 80% de ítems del instrumento. CONCLUSIONES: Se presenta el primer instrumento autoadministrado validado en la región, que permite medir conocimientos de las madres y los cuidadores sobre alimentación complementaria. A futuro, permitirá diseñar y desarrollar estrategias de evaluación e intervención en relación con los conocimientos maternos y de los cuidadores sobre alimentación complementaria.

INTRODUCTION: Adequate nutrition during the first two years of life is crucial for the full development of human potential. Inadequate, early, or late introduction of complementary feeding has consequences in the short- and long-term. Complementary feeding depends largely on the knowledge of the caregiver who, in Latin American countries, is usually the mother. OBJECTIVE: To create and validate an ins trument to measure knowledge about complementary feeding. SUBJECTS AND METHOD: Observational study in which 80 community mothers and 12 expert pediatricians participated. It was carried out in two stages, the creation of the instrument (following the 7 phases proposed by Sampieri) and the va lidation through the evaluation of the apparent validity, construct and content validity, internal con sistency, and intra-observer reliability. RESULTS: A self-administered instrument was created that ini tially included 14 questions about maternal and caregiver's knowledge. During the validation of the construct, 3 domains were identified and four questions were eliminated. In the content validation, 10 questions of the final instrument scored higher than 9 (on a scale of 0-10) in the characteristics of quality, vocabulary, relevance, and topicality. The global internal consistency of the instrument was moderate (Cronbach's alpha: 0.64) and the intra-observer reliability was acceptable (k: 0.21-0.40) for 80% of its items. CONCLUSIONS: the first self-administered instrument validated in the region to measure the knowledge of mothers and caregivers about complementary feeding is presented. It will allow to design and develop strategies in relation to maternal and caregiver's knowledge of comple mentary feeding.

Encefalitis anti NMDAR: Reporte de caso con seguimiento a largo plazo Anti-NMDAR / Encephalitis NMDAR: Case report with a long - term follow-up

Resumen La encefalitis autoinmune por anticuerpos antineurales de superficie, abarca un amplio espectro de entidades clínicas. La encefalitis por anticuerpos contra el antígeno de superficie de la porción externa del receptor del N-metil-D-aspartato (RNMDA) es la más frecuente y de mejor caracterización. Se reporta el caso de un adolescente con un cuadro clínico neurosiquiátrico y crisis epilépticas de reciente inicio, que presentó respuesta positiva para anticuerpos anti-RNMDA y respuesta parcial a tratamiento con corticoterapia e inmunoglobulina; en vista de esto, recibió manejo adicional con recambio plasmático seguido por terapia de mantenimiento con ciclos de inmunoglobulina, sin uso de inmunosupresores. Se reportan los resultados del seguimiento a largo plazo.

Summary Autoimmune encephalitis due to surface antineural antibodies covers a wide spectrum of clinical entities. Encephalitis due to antibodies against the surface antigen of the external portion of the N-methyl-D-aspartate receptor (RNMDA) is the most frequent and best characterized. The case of an adolescent with a clinical picture of neurosychiatric disorder and epileptic seizures of recent onset is presented: he had a positive response for anti-RNMDA antibodies, and a partial response to treatment with corticosteroid therapy and immunoglobulin; therefore, he received additional management with plasma exchange followed by maintenance therapy with immunoglobulin cycles, without the use of immunosuppressants. The results of a long-term follow-up are reported.

Construction and validation of an instrument to measure knowledge of mothers and caregivers on complementary feeding of infants. / Construcción y validación de un instrumento para medir conocimientos de madres y cuidadores sobre alimentación complementaria de infantes.

INTRODUCTION: Adequate nutrition during the first two years of life is crucial for the full development of human potential. Inadequate, early, or late introduction of complementary feeding has consequences in the short- and long-term. Complementary feeding depends largely on the knowledge of the caregiver who, in Latin American countries, is usually the mother. OBJECTIVE: To create and validate an ins trument to measure knowledge about complementary feeding. SUBJECTS AND METHOD: Observational study in which 80 community mothers and 12 expert pediatricians participated. It was carried out in two stages, the creation of the instrument (following the 7 phases proposed by Sampieri) and the va lidation through the evaluation of the apparent validity, construct and content validity, internal con sistency, and intra-observer reliability. RESULTS: A self-administered instrument was created that ini tially included 14 questions about maternal and caregiver's knowledge. During the validation of the construct, 3 domains were identified and four questions were eliminated. In the content validation, 10 questions of the final instrument scored higher than 9 (on a scale of 0-10) in the characteristics of quality, vocabulary, relevance, and topicality. The global internal consistency of the instrument was moderate (Cronbach's alpha: 0.64) and the intra-observer reliability was acceptable (k: 0.21-0.40) for 80% of its items. CONCLUSIONS: the first self-administered instrument validated in the region to measure the knowledge of mothers and caregivers about complementary feeding is presented. It will allow to design and develop strategies in relation to maternal and caregiver's knowledge of comple mentary feeding.

Ascariasis intestinal. Tres casos pediátricos con complicaciones severas en Cauca, Colombia / Intestinal ascariasis. Three pediatric cases with severe complications in Cauca, Colombia

Se presentan tres casos clínicos de niños atendidos en el Hospital Universitario San José de Popayán en Cauca, Colombia, quienes consultaron por una infección severa causada por Ascaris lumbricoides. La severidad de la infección tuvo como consecuencia en el primer caso una colangitis aguda, en el segundo caso una obstrucción intestinal con peritonitis generalizada, y en el tercer caso una perforación intestinal y choque séptico. El objetivo de mostrar estos casos es dar a conocer estas presentaciones clínicas poco frecuentes en el entorno médico. Además, se resalta la importancia del conocimiento sobre esta especie de parásito, que termina siendo un problema más de salud pública, no solo en nuestro país, sino en gran parte del mundo

We report three clinical cases of children treated at the San José University Hospital in Cauca, Colombia, who consulted with a severe infection caused by Ascaris lumbricoides. The severity of the infection resulted in acute cholangitis in the first case, in intestinal obstruction with generalized peritonitis in the second case, and in intestinal perforation and septic shock in the third case. The objective of this report is to inform the medical community about these unusual clinical presentations. In addition, the importance of this parasite is highlighted as a public health concern, not only in our country but also globally

Síndrome de Cri du chat: primer reporte en mosaico en el suroccidente colombiano / Cri du chat syndrome: first report of mosaicism in the colombian southwest

El síndrome de Cri du chat es una alteración cromosómica causada por deleciones en el brazo corto de cromosoma 5, las cuales varían en tamaño, desde muy pequeñas que comprometen solo el locus 5p15.2, hasta la pérdida de todo el brazo corto. Las mutaciones se originan de novo en el 80% a 90% de los casos. Existen dos regiones críticas para el síndrome de Cri du chat; una ubicada en 5p15.3, cuya deleción se manifiesta con el llanto de maullido de gato y retraso en el habla, y otra ubicada en 5p15.2, cuya deleción se manifiesta como microcefalia, hipertelorismo, retraso psicomotor y mental severo. Se han descrito varios genes implicados localizados en estas regiones críticas; entre ellos, TERT, SEMA5A, CTNND2 y MARCHF6, cuya haploinsuficiencia se asocia con los diferentes fenotipos del Cri du chat. En este artículo se describe el caso clínico de una paciente femenina de 8 meses de vida, con características clínicas y un análisis citogenético en mosaico que confirmaron el síndrome de Cri du chat. Este caso es el primero reportado de esta variante en el suroccidente colombiano.

Cri du chat syndrome is a chromosomal disorder caused by deletions in the short arm of chromosome 5, which vary in size, from very small and involving only the 5p15.2 locus, to the loss of the entire short arm. Mutations originate de novo in 80% to 90% of cases. There are two critical regions for Cri du chat syndrome; one located at 5p15.3 with a deletion that is manifested as a cat's cry and speech delay, and another located at 5p15.2 with a deletion that manifests as microcephaly, hypertelorism, severe psychomotor and mental retardation. Several involved genes located in these critical regions have been described; among them, TERT, SEMA5A, CTNND2 and MARCHF6, and whose haploinsufficiency is associated with the different phenotypes of Cri du chat. This article describes the clinical case of an 8-monthold female patient, with clinical characteristics and a mosaic cytogenetic analysis that confirmed Cri du chat syndrome. This case is the first reported of this variant in southwestern Colombia.

Fate of mercury in a terrestial biological lab process using Polypogon monspeliensis and Cyperus odoratus.

Mercury has been extracted in Queretaro, Mexico since the 1960s. The mining wastes were open-air disposal and these mercury wastes have polluted the zone. The aim of this research was to evaluate mercury's fate in lab scale terrestrial reactors considering the following mercury species: soluble, interchangeable, strongly bound, organic, and residual ones. Soils were sampled in two former mines of Pinal de Amoles, Queretaro, Mexico (N 20° 58' to 21° 21' and West 99° 26' to 99° 43') with initial mercury concentrations were 424 ± 29 and 433 ± 12 mg kg-1 for "La Lorena" and "San Jose" former mines, respectively. Two vegetal species Polypogon monspeliensis and Cyperus odoratus were used and 20 reactors were constructed for the lab process. Total mercury was removed to 49-79% from both soils. Mercury elemental, exchangeable, and organic species had the most removal or exchange in the process. Metal uptake, by the plants, was of 5-6% for P. monspeliensis and 5-15% for C. odoratus. Also, mercury fate was estimated to the atmosphere to be 3.3-4.5 mg m-2 h-1 for both soils.

Enfermedad descompresiva espinal: mielopatía isquémica secundaria a un accidente de buceo / Spinal cord decompression sickness: Ischemic myelopathy secondary to a diving accident

Se reporta el caso de un paciente de 34 años, buzo de profesión, hospitalizado por presentar de forma súbita confusión, debilidad generalizada, dolor intenso seguido de paraplejía y retención urinaria luego de emerger rápidamente desde una profundidad aproximada de 42 metros. El paciente fue admitido 48 horas después del evento habiendo completado dos sesiones de terapia de descompresión. Al examen se evidenció paraplejía flácida arrefléxica con nivel sensitivo a nivel de D5 global, reflejo plantar extensor bilateral y retención urinaria. En la resonancia magnética se evidenció incremento del calibre medular con alteración de señal en su diámetro anteroposterior, el cual es visto como hiperintensidad heterogénea en la secuencia T2 y STIR desde D2 hasta D11, sin dilatación del canal medular, compatible con lesión isquémica secundaria a enfermedad descompresiva. Recibió tratamiento con sesiones de cámara hiperbárica y corticoterapia (metilprednisolona 1g EV por 5días) con respuesta parcial.Se comenta la baja incidencia de esta patología enfermedad descompresiva secundaria a un accidente de buceo) y las peculiaridades de su presentación clínica.

We report the case of a 34-year-old male patient, a professional diver hospitalized in connection with a clinical picture characterized by sudden onset of disorientation, generalized weakness, intense body pain followed by sudden paraplegia and urinary retention. These manifestations occurred after a rapid ascent (10 minutes) from a depth of about 42 meters. He was admitted after having received two sessions of decompression therapy. Physical examination revealed flaccid paraplegia, bilateral extensor plantar reflex, a D5 sensitive level. Magnetic resonance imaging showed an increase in the medullar gauge with alteration of its signal, both in anterior and posterior areas, seen as a heterogeneous hyperintensity in the sequence T2 and STIR from D2 to D11, without dilatation of the spinal canal, compatible with ischemic injury. The diagnosis of ischemic myelopathy secondary to decompressive disease was made, and the patient received treatment with a hyperbaric chamber and a short course of steroids (Methylprednisolone 1g EV for 5 days) with partial response.The case is presented, and comments are made regarding the low incidence of this pathology and the variety of clinical peculiarities in its presentation.

Síndrome de Werner: a propósito de un caso probable / Werner's syndrome, about a probable case

Resumen: el síndrome de Werner es una patología poco frecuente, de herencia autosómica recesiva, caracterizado por signos de envejecimiento prematuro y tendencia a desarrollar tumores malignos. El diagnóstico de esta enfermedad es principalmente clínico, con hallazgos predominantes como talla baja y envejecimiento precoz. En este artículo se presenta el caso de un paciente de 49 años de edad, con signos tempranos de envejecimiento desde los 15 años y ateroesclerosis temprana asociada, que lo lleva a amputación quirúrgica de extremidad inferior derecha. De acuerdo con los criterios diagnósticos del síndrome de Werner este es el primer caso probable en el suroccidente colombiano. (AU)

Abstract: Werner syndrome is a rare, autosomal recessive pathology, characterized by signs of premature aging and tendency to develop malignant tumors. The diagnosis is principally clinical, with predominating findings as short stature and precocious aging. In this article, it's presented the case of a 49-year-old patient with early signs of aging from the age of 15 years and associated early atherosclerosis that leads to the right lower limb surgical amputation. According to the diagnostic criteria of Werner syndrome, this is the first probable case in the Colombian Southwest. (AU)

Síndrome de Loeys-Dietz, una mutación en el gen TGFBR2, primer reporte en el suroccidente colombiano / Loeys-Dietz syndrome, a mutation in TGFBR2 gene, first report in the colombian suroccident

Resumen: el síndrome de Loeys-Dietz es una rara enfermedad genética, autosómica dominante, con hábito marfanoide, que pertenece a un subconjunto de enfermedades del tejido conectivo con afectación esquelética, ocular y cardiovascular, principalmente. El desarrollo de aneurismas es característico en esta patología. El síndrome de Loeys-Dietz es causado por mutaciones en los genes TGFBR1, TGFBR2, TGFB2, TGFB3 Y SMAD3. En este manuscrito se describe el caso clínico de un paciente masculino, de 22 meses de vida, con una dilatación importante de la raíz aórtica y arco aórtico elongado cuya prueba molecular confirma el diagnóstico de síndrome de Loeys-Dietz, asociado a una mutación en el gen TGFBR2. Este corresponde al primer caso reportado en el suroccidente colombiano. (AU)

Abstract: Loeys-Dietz syndrome is a rare, autosomal dominant genetic disease, with marfanoid habit, which belongs to a subset of diseases of the connective tissue with mainly skeletal, ocular, and cardiovascular involvement. Aneurysms development is characteristic in this pathology. Loeys-Dietz syndrome is caused by mutations in TGFBR1, TGFBR2, TGFB2, TGFB3 and SMAD3 genes. In this manuscript is presented the clinical case of a 22-month-old male patient with significant dilatation of the aortic root and elongated aortic arch is described. The molecular test confirms the diagnosis of Loeys-Dietz syndrome associated with a mutation in the TGFBR2 gene. This corresponds to the first case reported in the southwestern Colombian. (AU)

Recent Advances of MEMS Resonators for Lorentz Force Based Magnetic Field Sensors: Design, Applications and Challenges.

Microelectromechanical systems (MEMS) resonators have allowed the development of magnetic field sensors with potential applications such as biomedicine, automotive industry, navigation systems, space satellites, telecommunications and non-destructive testing. We present a review of recent magnetic field sensors based on MEMS resonators, which operate with Lorentz force. These sensors have a compact structure, wide measurement range, low energy consumption, high sensitivity and suitable performance. The design methodology, simulation tools, damping sources, sensing techniques and future applications of magnetic field sensors are discussed. The design process is fundamental in achieving correct selection of the operation principle, sensing technique, materials, fabrication process and readout systems of the sensors. In addition, the description of the main sensing systems and challenges of the MEMS sensors are discussed. To develop the best devices, researches of their mechanical reliability, vacuum packaging, design optimization and temperature compensation circuits are needed. Future applications will require multifunctional sensors for monitoring several physical parameters (e.g., magnetic field, acceleration, angular ratio, humidity, temperature and gases).

Tylosin effect on methanogenesis in an anaerobic biomass from swine wastewater treatment.

The effect of different concentrations of tylosin on methane production was investigated: first methanogenesis in a biomass without contact with the antibiotic, and later the ability of the sludge to adapt to increasing concentrations of tylosin. Results showed that, for biomass that had no contact with the antibiotic, the presence of tylosin inhibits the generation of methane even at concentrations as small as 0.01 mg L(-1), and samples at concentrations above 0.5 mg L(-1) produced practically no methane, whereas, in the digesters acclimated in the presence of tylosin at a concentration of 0.01 to 0.065 mg L(-1), methanogenesis is not inhibited in the presence of antibiotic and the generation of methane is improved. This behaviour suggests the microorganisms have developed not only resistance to the antibiotic but also an ability to metabolize it.

Factors associated with length of hospital stay in minor and moderate burns at Popayan, Colombia. Analysis of a cohort study.

OBJECTIVE: To determine the independent contribution of prognostic factors to length of hospital stay of minor and moderate burn victims at the Hospital Universitario San José (HUSJ), Popayán, Colombia, 2000-2010. METHODS: This was a retrospective cohort study of minor and moderate burn victims admitted between 2000 and 2010, at the burn unit (HUSJ). This is a further analysis of a same cohort previously published in Burns. The following variables were recorded and analyzed: age, gender, origin, depth and extent of burn, causal agent, length of hospital stay and mortality. The main outcome under study was length of stay. Survival analysis was done to explore the association of covariates and length of hospital stay and Cox regression model to adjust the effect of covariates in the outcome. RESULTS: During the study period 2000-2010, 842 of 921 (91.5%) patients treated at the Burn Unit of HUSJ that had complete data were included. There were 520 (61.8%) males and 322 (38.2%) females with a male to female ratio of 1.6:1. Their median age was 9 years (IQR 3-28). The median of percent total body surface area burned (TBSA) was 12% (IQR 7-21) and the most common degree of burn was 2nd degree with 58% (488 patients). There were 12 deaths (censored data) and 830 patients were discharged alive. After multivariate adjustment, significant associations with length of hospital stay remained for age group, burn degree and extension of the burn. The strongest relationship found was for burn degree (2nd degree superficial vs. 3rd degree hazard ratio=2.66 CI 95% [2.13-3.33]). CONCLUSIONS: In patients admitted with mild and moderate burns at HUSJ, the main predictors of length of stay were age, burn degree and extension of the burn.

Performance of a biofilter system with agave fiber filter media for municipal wastewater treatment.

Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m(3) m(-2) d(-1)). One series was conducted using mechanical aeration (0.62 m(3) m(-2) h(-1)). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m(3) m(-2) d(-1), the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes.

Occurrence of tylosin in swine wastewater in Mexico.

This study determined a tylosin concentration in swine wastewater located in a Mexican pig farm, during different stages of the pigs' growth. The detection of antibiotics in swine wastewater is complex due to its high concentration of solids. Analytical method was developed for detection of tylosin in swine wastewater and swine slurry. Average recoveries of tylosin in the liquid and solid phase were greater than 51 and 44%, respectively, with a greater total recovery of 95%. The results indicated the presence of tylosin in swine wastewater and slurry at concentrations greater than the ones reported in the literature. In grab samples of swine wastewater, the tylosin detected showed concentrations of 56, 72 and 8.6 µg L(-1), in breeding-gestation, nursery pigs, and grow-finishing area, respectively. In composite samples, the concentration of tylosin was 11.8 µg L(-1) for the breeding-gestation area and 2.4 µg L(-1) for the grow-finishing area. For slurry, the concentration of tylosin was 20.6 and 17.8 µg L(-1), for the breeding-gestation and grow-finishing area, respectively. This study presents the detection of a high concentration of tylosin in breeding-gestation and nursery pigs. Traces of tylosin in wastewater from grow-finishing stage were found although the animals were not receiving antibiotics.

Epidemiological profile of minor and moderate burn victims at the University Hospital San José, Popayán, Colombia, 2000-2010.

OBJECTIVES: To describe the epidemiological profile of minor and moderate burn victims at the University Hospital San José, Popayán, Colombia, 2000-2010. METHODS: This study was retrospective description of minor and moderate burn victims admitted between 2000 and 2010 at the Burn Unit of University Hospital San José (UHSJ). The following variables were recorded and analyzed: age, gender, origin, social security, depth and extent of burn, days of hospitalization, causal agent and mortality. SPSS 19.0 was used. The level of significance was p<0.05. RESULTS: During 2000-2010, 845 patients were included. 61.7% were men. The average age was 17.9 years. Most of patients were from rural areas (80.4%). Most people belonged to the Subsidized Health Colombian System (85.3%). The most common causal agent was scalding liquids (49.7%). The most frequent depth was second degree burns (57.8%) and the average burned body surface was 20%. The average hospital stay was 20.4 days, and the median hospitalization time was 14 days. Mortality was 1.4%. CONCLUSIONS: The findings of this study are the first to define the characteristics of burns in Popayán. This study is the basis for identifying preventative measures in the local health care system.