The cnf1 gene is associated with an expanding Escherichia coli ST131 H30Rx/C2 subclade and confers a competitive advantage for gut colonization.

Epidemiological projections point to acquisition of ever-expanding multidrug resistance (MDR) by Escherichia coli, a commensal of the digestive tract and a source of urinary tract pathogens. Bioinformatics analyses of a large collection of E. coli genomes from EnteroBase, enriched in clinical isolates of worldwide origins, suggest the Cytotoxic Necrotizing Factor 1 (CNF1)-toxin encoding gene, cnf1, is preferentially distributed in four common sequence types (ST) encompassing the pandemic E. coli MDR lineage ST131. This lineage is responsible for a majority of extraintestinal infections that escape first-line antibiotic treatment, with known enhanced capacities to colonize the gastrointestinal tract. Statistical projections based on this dataset point to a global expansion of cnf1-positive multidrug-resistant ST131 strains from subclade H30Rx/C2, accounting for a rising prevalence of cnf1-positive strains in ST131. Despite the absence of phylogeographical signals, cnf1-positive isolates segregated into clusters in the ST131-H30Rx/C2 phylogeny, sharing a similar profile of virulence factors and the same cnf1 allele. The suggested dominant expansion of cnf1-positive strains in ST131-H30Rx/C2 led us to uncover the competitive advantage conferred by cnf1 for gut colonization to the clinical strain EC131GY ST131-H30Rx/C2 versus cnf1-deleted isogenic strain. Complementation experiments showed that colon tissue invasion was compromised in the absence of deamidase activity on Rho GTPases by CNF1. Hence, gut colonization factor function of cnf1 was confirmed for another clinical strain ST131-H30Rx/C2. In addition, functional analysis of the cnf1-positive clinical strain EC131GY ST131-H30Rx/C2 and a cnf1-deleted isogenic strain showed no detectable impact of the CNF1 gene on bacterial fitness and inflammation during the acute phase of bladder monoinfection. Together these data argue for an absence of role of CNF1 in virulence during UTI, while enhancing gut colonization capacities of ST131-H30Rx/C2 and suggested expansion of cnf1-positive MDR isolates in subclade ST131-H30Rx/C2.

Implementación de un programa basado en IPASS en UCI / Implementation of an IPASS-based program in the ICU

Introducción: El uso de herramientas estandarizadas como estrategia de comunicación para brindar información relevante, precisa y actualizada, forma parte de las iniciativas de calidad en las instituciones que cumplen altos estándares en la atención de pacientes. Objetivo: Describir la implementación de un programa de traspaso (IPASS) en unidades de cuidados intensivos pediátricos específicos. Material y métodos: Estudio cuasi-experimental antes y después de una intervención, no controlado, utilizando como sujetos a los profesionales de la salud involucrados en traspasos de pacientes de la unidad de terapia intensiva cardiovascular (UCI 35) e inmunosuprimidos (UCI 72). La intervención consistió en la introducción de un paquete de medidas de estandarización del traspaso de pacientes que consta de: una herramienta escrita, una mnemotecnia oral, una capacitación de trabajo en equipo, observación y devolución estandarizada de los traspasos, basados en la metodología IPASS. Se realizó además una encuesta de percepción de seguridad, tanto en la etapa pre y post intervención. Se comparó el cumplimiento de cada componente del traspaso antes y después de la intervención mediante la prueba de chi2 . Resultados: Se realizaron 101 observaciones de traspaso y 56 encuestas. La mediana de pacientes por cada observación fue 6 (r: 4 a 12) y el tiempo promedio de 26± 11 min. Conclusiones: El uso de un paquete de medidas de estandarización del traspaso de pacientes posquirúrgicos cardiovasculares e inmunosuprimidos aumentó significativamente la presencia de información clave sobre criticidad de la enfermedad, acciones y situaciones de contingencia, junto con la inclusión de la síntesis por el receptor del traspaso (AU)

Introduction: The use of standardized tools as a communication strategy to provide relevant, accurate, and up-to-date information is part of quality initiatives in institutions that adhere to high standards in patient care. Objective: To describe the implementation of a handoff program (IPASS) in specific pediatric intensive care units. Methods: An uncontrolled, quasi-experimental, beforeand-after study. Subjects were healthcare providers involved in patient handoffs in the cardiovascular (ICU 35) and immunocompromised-patient (ICU 72) intensive care units. The intervention consisted of the introduction of a bundle to standardize patient handoff consisting of: a written tool, an oral mnemonic, teamwork training, observation, and standardized feedback for handoffs based on the IPASS methodology. A safety perception survey was also carried out, both in the pre- and post-intervention stage. Compliance with each handoff component before and after the intervention was compared using the Chi-squared test. Results: 101 handoff observations and 56 surveys were conducted. The median number of patients per observation was 6 (r: 4 to 12) and the mean handoff time was 26±11 min. Conclusions: The use of a standardized handoff bundle for post-surgical cardiovascular and immunocompromised patients significantly increased the availability of key information on disease severity, actions, and contingency situations, as well as a synthesis by the handoff receiver (AU)

Evolución de pacientes con bronquiolitis tratados con cánulas de alto flujo de oxígeno que ingresan a la unidad de cuidados intensivos / Outcome of patients with bronchiolitis treated with high-flow oxygen nasal cannulas admitted to the intensive care unit

Objetivo: Describir la evolución en la Unidad de Cuidados Intensivos Pediátricos (UCIP) de los pacientes con bronquiolitis, tratados inicialmente con cánula nasal de alto flujo de oxígeno (CAFO) en la Unidad Emergencias. Determinar factores predisponentes de ingreso a ventilación no invasiva (VNI) o invasiva con intubación orotraqueal (TET). Métodos: Trabajo descriptivo retrospectivo por revisión de historias clínicas. Se incluyeron todos los pacientes menores de 2 años de edad con diagnóstico de bronquiolitis, sin comorbilidades, que ingresaron a UCIP polivalente luego de haber sido previamente tratados con CAFO en la Unidad de Emergencias entre los meses de Agosto 2017 y Agosto 2019. Resultados: Se evaluaron 145 pacientes. La mediana de edad fue de 4,4 meses (RIC 2-6 meses), con una mediana de tiempo desde el inicio de los síntomas hasta la consulta de 45,4 hs (RIC 24-72). La mediana del score de TAL modificado al ingreso a UCIP 8,4 (RIC 8-9). El 98,6% requirió asistencia respiratoria mecánica (ARM), en el grupo VNI 52,4% (75) y en el grupo TET 47,5% (68). El rescate de germen fue en 60% de los casos virus sincicial respiratorio (VSR). El 5,5% fueron co-infecciones. De los pacientes con rescate positivo para VSR, el 52,9% (46) requirieron VNI y 47,1% (41) TET. Los pacientes estudiados permanecieron en CAFO una mediana de 20 hs previo al ingreso a UCIP (RIC: 6-24). Aquellos que estuvieron en VNI con una mediana de 23,3 hs (RIC 6-24) y los que requirieron TET 17 hs (RIC 6-21). La mortalidad evidenciada en el grupo TET fue de 1,38% correspondiente a 2 pacientes, donde también se encontró un 7,5% de complicaciones. La mediana de días de internación en UCIP fue de 8,6 (5-11) para la totalidad de la población estudiada siendo 5,2 (4-6) para los pacientes en VNI y 12 días (9-14) para los pacientes en TET. Conclusiones: Casi la totalidad de pacientes tratados con CAFO en la Unidad Emergencias que requirieron pasar a UCI necesitaron ARM. Ni el score de TAL ni la cantidad de horas de CAFO previo al ingreso en UCI nos permitieron diferenciar los pacientes del grupo VNI de aquellos del grupo TET (AU)

Objective: To describe outcome of patients who were admitted to the pediatric intensive care unit (PICU) with bronchiolitis initially treated with high-flow oxygen through a nasal cannula (HFNC) at the emergency department and to determine predisposing factors for the need for non-invasive ventilation (NIV) or invasive endotracheal intubation (ETI). Methods: A retrospective descriptive study with a review of the clinical records was conducted. All patients less than 2 years of age with bronchiolitis without comorbidities that were admitted to the general PICU following treatment with HFNC at the emergency department between August 2017 and August 2019 were included in the study. Results: 145 patients were evaluated. Median age was 4.4 months (IQR 2-6 months). Median time from symptom onset to first consultation was 45.4 hours (IQR 24-72). Median modified TAL score on PICU admission was 8.4 (IQR 8-9). Overall 98,6% required mechanical ventilation (MV), 52.4% (75) in the NIV and 47.5% (68) in the ETI group. In 60% of the cases respiratory syncytial virus (RSV) was isolated. Co-infections were found in 5.5%. Of the patients with an RSV-positive isolate, 52.9% (46) required NIV and 47.1% (41) ETI. Patients had remained on HFNC for a median of 20 hours prior to PICU admission (IQR 6-24). Patients were on NIV for a median time of 23.3 hours (IQR 6-24) and on ETI for a median time of 17 hours (IQR 6-21). In the ETI group, mortality rate was 1.38%, corresponding to two patients, while the complication rate was 7.5%. Median length of PICU stay was 8.6 days (5-11) for the entire study population, 5.2 days (4-6) for patients on NIV, and 12 days (9-14) for those on ETI. Conclusions: Almost all patients treated with HFNC at the emergency department who required admission to the PICU needed MV. Neither TAL score nor time on HFNC allowed us to differentiate patients requiring NIV from those who needed ETI (AU)

Cryosurvival after exposure of IVF-derived Nellore embryos to different cryoprotectants and exposure times during vitrification.

We evaluated the effects of the vitrification solution (i.e., ethylene glycol (EG) + dimethyl sulfoxide (DMSO) with or without propylene glycol (PG)) and of exposure time on the re-expansion and hatching rates of vitrified Bos indicus embryos. In vitro produced embryos (n = 1050) were divided into seven groups: control group (non-vitrified embryos) and six vitrification groups with different cryoprotectant concentrations and exposure times. After vitrification, embryos were cultured for determination of re-expansion and hatching rates. Vitrification with 25% DMSO +25% EG (exposure for 1 min and 20 s) resulted in the highest re-expansion (65.2%) and hatching (68.2%) rates. The lowest re-expansion and hatching rates were observed in vitrification with 12.5% DMSO + 25% EG + 12.5% PG with both tested exposure times (i.e., 3 min + 1 min and 1 min + 20 s). A combination of DMSO + EG is efficient to preserve blastocysts, especially following a short exposure time.

Circadian Control of Antibacterial Immunity: Findings from Animal Models.

Most of the biological functions, including the immune system, are linked to circadian rhythms in living organisms. Changes occurring to biological parameters as the result of these circadian rhythms can therefore affect the outcome of a disease. For decades, model organisms have proven to be a great tool to understanding biological mechanisms such as circadian cycle and immunity. In this review, we created an inventory of the use of model organisms in order to decipher the relation between circadian rhythms and antibacterial immunity.

Evaluation of a national pharmacy-based syndromic surveillance system.

BACKGROUND: Traditional public health surveillance provides accurate information but is typically not timely. New early warning systems leveraging timely electronic data are emerging, but the public health value of such systems is still largely unknown. OBJECTIVE: To assess the timeliness and accuracy of pharmacy sales data for both respiratory and gastrointestinal infections and to determine its utility in supporting the surveillance of gastrointestinal illness. METHODS: To assess timeliness, a prospective and retrospective analysis of data feeds was used to compare the chronological characteristics of each data stream. To assess accuracy, Ontario antiviral prescriptions were compared to confirmed cases of influenza and cases of influenza-like-illness (ILI) from August 2009 to January 2015 and Nova Scotia sales of respiratory over-the-counter products (OTC) were compared to laboratory reports of respiratory pathogen detections from January 2014 to March 2015. Enteric outbreak data (2011-2014) from Nova Scotia were compared to sales of gastrointestinal products for the same time period. To assess utility, pharmacy sales of gastrointestinal products were monitored across Canada to detect unusual increases and reports were disseminated to the provinces and territories once a week between December 2014 and March 2015 and then a follow-up evaluation survey of stakeholders was conducted. RESULTS: Ontario prescriptions of antivirals between 2009 and 2015 correlated closely with the onset dates and magnitude of confirmed influenza cases. Nova Scotia sales of respiratory OTC products correlated with increases in non-influenza respiratory pathogens in the community. There were no definitive correlations identified between the occurrence of enteric outbreaks and the sales of gastrointestinal OTCs in Nova Scotia. Evaluation of national monitoring showed no significant increases in sales of gastrointestinal products that could be linked to outbreaks that included more than one province or territory. CONCLUSION: Monitoring of pharmacy-based drug prescriptions and OTC sales can provide a timely and accurate complement to traditional respiratory public health surveillance activities but initial evaluation did not show that tracking gastrointestinal-related OTCs were of value in identifying an enteric disease outbreak in more than one province or territory during the study period.

Estudio comparativo de dos modos de ventilación no invasiva para retirar la asistencia respiratoria mecánica en lactantes post-operatorios de cirugía cardiovascular / Comparative study of two modalities of non-invasive ventilation for the weaning from mechanical ventilation of post-cardiovascular surgery infants

La mejor estrategia en el post-quirúrgico de cardiopatías congénitas para promover la extubación precoz y destete de asistencia respiratoria mecánica (ARM) con ventilación no invasiva (VNI) todavía no ha sido establecida. El objetivo es comparar eficacia de la presión positiva continua en la vía aérea (CPAP) vs presión positiva con dos niveles en la vía aérea (BIPAP) en la extubación electiva de estos pacientes. Es un estudio prospectivo entre el 1 de junio de 2008 y 31 marzo de 2010. Se randomizaron los pacientes para extubación electiva: modo CPAP o BIPAP. Se registraron datos demográficos y del procedimiento quirúrgico, entre otros. El fracaso de VNI fue definido como reintubación dentro de las 72 hs posteriores a la extubación o más de un criterio de intubación. Durante el periodo de estudio 1438 pacientes fueron admitidos en UCI35. En el grupo BIPAP se randomizaron 53 pacientes, de los cuales se extubaron exitosamente 49 (92%), pero 4 se reintubaron debido a falla cardiaca. En el grupo CPAP se randomizaron 46 y fallaron en la extubación 18 (39%) debido a múltiples episodios de desaturación y apneas. De éstos, 11 requirieron reintubación endotraqueal y ARM. En 7 pacientes, se pasó a modo BIPAP y permanecieron extubados, aunque el cruzamiento no fue parte del diseño de este estudio. En el destete de ARM de los pacientes post-quirúrgicos de cardiopatías congénitas, el uso de BIPAP fue más efectivo que CPAP. En esta última modalidad se presentaron mayor número de fracasos de VNI (AU)

The best strategy for early extubation and weaning from mechanical respiration (MV) with non-invasive ventilation (NIV) in post-surgical congenital heart defect patients has not been established yet. The aim of this study was to compare the efficacy of continuous positive airway pressure CPAP) vs bi-level positive airway pressure (BIPAP) in the elective extubation of these patients. A prospective study was conducted between June 1, 2008 and March 31, 2010. Patients that were candidates for elective extubation were randomized to CPAP or BIPAP. Data on demographics and surgical procedure, among others, were recorded. Failure of NIV was defined as the need for reintubation within 72 hours after extubation or more than one criterion for intubation. Over the study period, 1438 patients were admitted to ICU 35. Fifty-three patients were randomized to BIPAP, of whom 49 (92%) were successfully extubated; however, four were reintubated due to heart failure. Forty-six patients were randomized to CPAP. Extubation failed in 18 (39%) due to multiple episodes of desaturation and apneas. Eleven of 18 required endotracheal reintubation and mechanical ventilation. Seven patients were switched to BIPAP and remained extubated, although the switch was not part of the study design. In the weaning of post-surgical congenital heart defect patients from MV, BIPAP was more effective than CPAP. In the latter modality, the incidence of NIV failure was higher (AU)

Foodborne outbreaks in Canada linked to produce: 2001 through 2009.

Foodborne disease outbreaks associated with fresh fruits and vegetables have been increasing in occurrence worldwide. Canada has one of the highest per capita consumption rates of fresh fruits and vegetables in the world. In this article, we review the foodborne disease outbreaks linked to produce consumption in Canada from 2001 through 2009. The 27 produce-related outbreaks included an estimated 1,549 cases of illness. Bacterial infection outbreaks represented 66% of the total. Among these, Salmonella was the most frequent agent (50% of outbreaks) followed by Escherichia coli (33%) and Shigella (17%). Cyclospora cayetanensis was the only parasite detected and was associated with seven outbreaks. Among the foodborne viruses, only hepatitis A was implicated in two outbreaks. The food vehicles most commonly implicated in outbreaks were leafy greens and herbs (26% of outbreaks), followed by seed sprouts (11%). Contamination sources and issues related to the future control of fresh produce-related foodborne disease outbreaks also are discussed.

Regional venous oxygen saturation versus mixed venous saturation after paediatric cardiac surgery.

BACKGROUND: Central venous oxygen saturation (ScvO2) remains the gold standard surrogate for tissue oxygen extraction in paediatric cardiac surgery. Near-infrared spectroscopy (NIRS) has been developed as a non-invasive diagnostic tool for regional oxygen saturation. The aim was to compare regional oxygen saturation measured by NIRS with ScvO2 in postoperative paediatric cardiac patients. METHODS: In this prospective study, we included newborns and infants younger than 45 days undergoing heart surgery. We recorded continuous ScvO2 and NIRS regional saturation placed on the forehead (B) and right flank (S) for 48 h postoperatively. A Bland-Altman's analysis was used to assess the agreement between these measurements. RESULTS: A total of 23 patients were included with a median age of 12 days (2-46) and median weight of 3.1 kg (2.3-4.47). The mean difference (MD) ScvO2- B NIRS was 10.45% with limits of agreement (LOA) -17.23 to 38.13% and ScvO2- S NIRS MD 7.16% with LOA: -25.51 to 39.84%. The single ventricle ScvO2- S NIRS subgroup had MD within ± 5%; however, wide LOA was observed. The remaining subgroups showed MD nearly above ± 5%, with wide LOA. CONCLUSIONS: The regional oxygen saturation of brain and kidney did not match ScvO2 as estimation of global tissue perfusion. Nevertheless, NIRS may still provide information regarding regional circulation that may help in the management of neonatal cardiac surgery patients.

Ventilación de alta frecuencia en niños postoperatorios de cirugía cardiovascular: experiencia de diez años / High-frequency ventilation after heart surgery in children: a 10-year experience

La ventilación de alta frecuencia (VAF) es una herramienta de uso limitado en el pos- operatorio de cirugía cardiovascular pediátrica. El objetivo de la presente revisión es describir los resultados del uso de VAF en la Unidad de Recuperación Cardiovascular del Hospital de Pediatría Juan P. Garrahan. A tal fin se revisaron las historias clínicas de todos los pacientes en los cuales se utilizó VAF en el período comprendido entre el 1º de enero de 2001 y el 31 de diciembre de 2010. Se registraron variables demográficas, diagnóstico, tipo de cirugía, parámetros utilizados en la VAF, sus complicaciones y mortalidad. La VAF se utilizó en 16 pacientes (10 mujeres) con una mediana de edad de 13 meses (1-72) y de peso de 7,9 kilos (3-18). Nueve de ellos presentaban una cardiopatía congénita cianótica y a todos ellos se les realizó una cirugía reparadora, excepto un paciente con diagnóstico de ventrículo único al que se le realizó cirugía paliativa. La indicación de VAF fue la hipoxemia en 11 pacientes y la hipoxemia con hipercapnia en 5. El 62% presentó algún grado de intolerancia hemodinámica, pero en ningún caso debió suspenderse el procedimiento por esta causa. La sobrevida, con egreso hospitalario fue de 44%. La VAF puede ser útil como técnica de soporte respiratorio en pacientes pos- operatorios cardíacos adecuadamente seleccionados

igh-frequency ventilation (HFV) is a technique with limited use in pediatric post-operative cardiovascular care. The aim of the present review is to evaluate the results of the use of HFV in the cardiac intensive care unit of the Pediatric Hos-pital Juan P. Garrahan. We reviewed the clinical charts of all patients who were placed on HFV over the period of January 1, 2001 to December 31, 2010. Demographic features, di-agnosis, type of surgery, HFV parameters used, HFV–related complications, and mortality were assessed. Sixteen patients (10 girls) with a median age of 13 months (1-72) and a median weight of 7.9 kg (3-18) were placed on HFV. Nine children had a cyanotic heart defect and all children underwent corrective surgery, except one who had a single ventricle defect. HFV was indicated for hypoxemia in 11 patients and for hypoxemia and hypercapnia in five. Sixty-two percent of the patients had some degree of hemodynamic impairment, however, HFV was not withdrawn for this reason in any of the cases. Survival to hospital discharge was 44%. HFV may be useful as a mechani-cal ventilation technique in carefully-selected post-operative cardiovascular patients.

Effect of the aqueous extract of Senecio biafrae (Oliv. & Hiern) J. Moore on sexual maturation of immature female rat.

BACKGROUND: Senecio biafrae (Asteraceae) is a medicinal plant widely used by traditional healers in the western region of Cameroon for the treatment of female infertility. This experiment was designed to evaluate the effect of the aqueous extract from leaves and stems of S. biafrae (AESb) on the onset of puberty and some biochemical and physiological parameters of reproduction in immature Wistar female rats. METHODS: Different doses of AESb were daily and orally administered to immature female rats (13 animals/group) for 30 days. At the end of the treatment period, six animal of each experimental group were sacrificed and their body, ovarian, uterus weight; uterine, ovarian protein or cholesterol level as well as data on puberty onset recorded. The remaining animals of each group were used for the fertility test and some gestational parameters recorded. RESULTS: A linear increase in the growth rate of all animals was observed. The body weight gain in animals treated at the dose of 8 mg/kg of AESb significantly increased (p < 0.05) after 25 days of treatment while those receiving the doses of 32 and 64 mg/kg presented a significantly low body weight gain starting from the 19th day till the end of the treatment period. The ages (days) of animals at vaginal opening (VO) was significantly reduced (p < 0.05) in those treated with the doses of 32 (41.25 ± 0.51) and 64 mg/kg (41.42 ± 0.54) as compared to control animals (43.33 ± 0.73). AESb significantly increased (p < 0.05) the ovarian weight and the number of corpora lutea in animals treated with 8 mg/kg as well as the uterine weight and protein levels irrespective of the dose. No significant effect of the extract on various fertility and gestational parameters was registered. CONCLUSION: The overall results of the present study provide evidence on the puberty onset induction and ovarian folliculogenesis effect of AESb in immature female rat.

Perceptions of diabetes, barriers to disease management, and service needs: a focus group study of working adults with diabetes in Hawaii.

INTRODUCTION: Research about the support needs for and barriers to successful disease management of working adults with diabetes is limited. Our objective was to gain an in-depth understanding of how working adults in Hawaii perceive diabetes, barriers to disease management, and the services needed to keep people healthy and working. METHODS: From November 2008 through March 2009, we conducted focus group interviews with 74 employed adults with diabetes enrolled in the Hawaii Demonstration to Maintain Independence and Employment project. Responses to questions were analyzed within and across groups to identify recurring themes. A third layer of analysis examined themes across responses to all questions, specifically, how barriers related to identified service needs. RESULTS: Employed participants with diabetes experienced pervasive effects on their lives as a result of the disease, although they interpreted these effects positively or negatively. Barriers to disease management, such as additional health issues, social prejudice, and lack of social support, indicated a need to educate the general public about the disease. Participants identified needing social support from other people with diabetes, psychological support to address the emotional side of diabetes, and coordinated teams of specialists to address medication side effects and other health-related barriers to disease management. Many participants discussed the challenge of integrating diabetes management with work and family responsibilities and the need for monetary support. CONCLUSION: This study provides insight into how employed adults perceived their disease and what they perceived as challenges to successfully managing diabetes. The findings provide future directions for community and workplace diabetes initiatives.

Role of epibenthic resource opportunities in the parallel evolution of lake whitefish species pairs (Coregonus sp.).

Parallel evolution of a dwarf and normal whitefish has been documented in six post-glacial lakes. Here, we relate the structure and seasonal variations of the epibenthic invertebrate communities to the extent of phenotypic differentiation in these species pairs. The highest phenotypic differentiation occurs in lakes characterized by less overlap in size distribution between limnetic and epibenthic prey which could represent enhanced ecological opportunities for trophic specialization and adaptive divergence. Differences in community assemblages and seasonal variation of biotic and abiotic conditions may also play a role. Accumulating evidence indicates that strong directional selection acting on dwarf whitefish may be more important than divergent selection acting on both sympatric forms in driving whitefish phenotypic divergence and ultimately, ecological speciation. Along with Landry et al. (2007), this study supports the general hypothesis that parallelism in divergence among sympatric dwarf and normal whitefish is associated with parallelism in limnological adaptive landscape.

Parallel evolution of lake whitefish dwarf ecotypes in association with limnological features of their adaptive landscape.

Sympatric fish populations observed in many north temperate lakes are among the best models to study the processes of population divergence and adaptive radiation. Despite considerable research on such systems, little is known about the associations between ecological conditions and the extent of ecotypic divergence. In this study, we examined the biotic and abiotic properties of postglacial lakes in which lake whitefish, Coregonus clupeaformis, occur as a derived dwarf ecotype in sympatry with an ancestral normal ecotype. We compared 19 limnological variables between two groups of lakes known from previous studies to harbour sympatric dwarf and normal ecotypes with high and low levels of phenotypic and genetic differentiation respectively. We found clear environmental differences between the two lake groups. Namely, oxygen was the most discriminant variable, where lakes harbouring the most divergent populations were characterized by the greatest hypolimnetic oxygen depletion. These lakes also had lower zooplankton densities and a narrower distribution of zooplantonic prey length. These results suggest that the highest differentiation between sympatric ecotypes occurs in lakes with reduced habitat and prey availability that could increase competition for resources. This in turns supports the hypothesis that parallelism in the extent of phenotypic divergence among sympatric whitefish ecotypes is associated with parallelism in adaptive landscape in terms of differences in limnological characteristics, as well as availability and structure of the zooplanktonic community.

Factores de riesgo de infección en cirugía cardiovascular / Risk factors for infection in cardiovascular surgery

Introducción: Las infecciones en cirugía cardiovascular son una importante causa de morbi mortalidad. Objetivos: conocer la incidencia de infección y los factores de riesgo relacionados con la misma. Material y Métodos:Se incluyeron todos los pacientes(p) mayores de 1 mes y menores de 18 años sometidos a cirugía cardiovascular en el período comprendido enre el 1/11/01 y el 1/1/02. Se analizaron los siguientes factores de riesgo; edad, sexo, tipo de cardiopatía, patología de base,internación,infección, uso de antibióticos y cirugía previa, score de American Society of Anesthesiology (ASA), tiempo de bomba, material protésico, requerimiento de inotrópicos,asistencia respiratoria mecánica(ARM), vías centrales, sonda vesical, drenaje de tórax, tipo de infección, germen y evolución. Resultados: Se incluyeron 350p de los cuales 184p (53 po ciento) eran de sexo masculino. La mediana de edad fue de 30 meses (r:1 menos 212m).Tenía patología de Base 75p (21 por ciento). La comunicación interventricular, la Tetralogía de Fallot y la comunicación interauricular fueron las cardiopatías más frecuentes (46 por ciento). 56p (16 por ciento) tenía cirugía previa y 30p (9 por ciento) habían tenido infección. El score de ASA fue igual o mayor de 3 en 308p (88 por ciento). La mediana de internación previa fue de un día (r:1 menos 120d). La mediana de tiempo de bomba fue de 69 minutos(13 menos 300m), 88p (25 por ciento)requirieron soporte inotrópico con una mediana de 5 días (r:1 menos 62d),147p (42 por ciento) requirieron ARM con una mediana de 4d(r:1 menos 66d). La estadía hospitalaria fue de una mediana de 5d (r:1 media 120d);38p (11 por ciento)desarrollaron infección: del sitio quirúrgico en 12p (3.5 por ciento) y 26p (7.5 por ciento)fuera del mismo. Fallecieron 11p (3 por ciento). Por análisis univariado la menor edad, la patología de base, el score de ASA mayor o igual a 3, la infección previa, el requerimiento de soporte inotrópico, el tiempo prolongado de bomba, la ARM y la estadía hospitalaria mayor de 12 días fueron factores de riesgo de infección significativos (p<0.05). Por análisis multivariado sólo fueron la patalogía de base (p<0.012).OR 4.22 (1.38 menos 12.8), el requerimiento del soporte inotrópico (p<0.027), OR 4.04(1.17 menos 13.9) y la estadía poscirugía mayor de 12 días (p<0.003), OR 1.08(1.03 menos 1.14). Conclusión: Las infecciones son una importante causa de morbimortalidad en cirugía cardiovascular

Factores de riesgo de infección en cirugía cardiovascular / Risk factors for infection in cardiovascular surgery

Introducción: Las infecciones en cirugía cardiovascular son una importante causa de morbi mortalidad. Objetivos: conocer la incidencia de infección y los factores de riesgo relacionados con la misma. Material y Métodos:Se incluyeron todos los pacientes(p) mayores de 1 mes y menores de 18 años sometidos a cirugía cardiovascular en el período comprendido enre el 1/11/01 y el 1/1/02. Se analizaron los siguientes factores de riesgo; edad, sexo, tipo de cardiopatía, patología de base,internación,infección, uso de antibióticos y cirugía previa, score de American Society of Anesthesiology (ASA), tiempo de bomba, material protésico, requerimiento de inotrópicos,asistencia respiratoria mecánica(ARM), vías centrales, sonda vesical, drenaje de tórax, tipo de infección, germen y evolución. Resultados: Se incluyeron 350p de los cuales 184p (53 po ciento) eran de sexo masculino. La mediana de edad fue de 30 meses (r:1 menos 212m).Tenía patología de Base 75p (21 por ciento). La comunicación interventricular, la Tetralogía de Fallot y la comunicación interauricular fueron las cardiopatías más frecuentes (46 por ciento). 56p (16 por ciento) tenía cirugía previa y 30p (9 por ciento) habían tenido infección. El score de ASA fue igual o mayor de 3 en 308p (88 por ciento). La mediana de internación previa fue de un día (r:1 menos 120d). La mediana de tiempo de bomba fue de 69 minutos(13 menos 300m), 88p (25 por ciento)requirieron soporte inotrópico con una mediana de 5 días (r:1 menos 62d),147p (42 por ciento) requirieron ARM con una mediana de 4d(r:1 menos 66d). La estadía hospitalaria fue de una mediana de 5d (r:1 media 120d);38p (11 por ciento)desarrollaron infección: del sitio quirúrgico en 12p (3.5 por ciento) y 26p (7.5 por ciento)fuera del mismo. Fallecieron 11p (3 por ciento). Por análisis univariado la menor edad, la patología de base, el score de ASA mayor o igual a 3, la infección previa, el requerimiento de soporte inotrópico, el tiempo prolongado de bomba, la ARM y la estadía hospitalaria mayor de 12 días fueron factores de riesgo de infección significativos (p<0.05). Por análisis multivariado sólo fueron la patalogía de base (p<0.012).OR 4.22 (1.38 menos 12.8), el requerimiento del soporte inotrópico (p<0.027), OR 4.04(1.17 menos 13.9) y la estadía poscirugía mayor de 12 días (p<0.003), OR 1.08(1.03 menos 1.14). Conclusión: Las infecciones son una importante causa de morbimortalidad en cirugía cardiovascular