[Effectiveness of tranexamic acid for decreased allogenic blood transfusion in total hip arthroplasty]. / Eficacia del ácido tranexámico para la disminución de la transfusión de sangre alogénica en la artroplastía total de cadera.

INTRODUCTION: ATC can cause considerable blood loss. To reduce the need for blood transfusion, various preoperative techniques such as administration of tranexamic acid (ATX) are used. OBJECTIVE: to demonstrate that the use of ATX decreases the need for allogeneic blood transfusion in patients operated on ATC. MATERIAL AND METHODS: Prospective, observational, descriptive study, used to observe the allogeneic blood transfusion rate in patients who underwent unilateral primary ATC from May 2016 to December 2017. ATX was applied preoperatively and after 24 hours a blood count was taken and the need for blood transfusion was assessed. RESULTS: A total of 70 patients were included in the study. The average postoperative Hb 11.7 mg/dl with a range of 9.2 to 14.9 mg/dl and an average Ht of 37.1% with a range of 30.2 to 44.2%. None of the patients required allogeneic blood transfusión. CONCLUSIONS: This study demonstrates how ATX is a transoperative strategy to reduce the need for allogeneic blood transfusion in patients undergoing primary ATC.

INTRODUCCIÓN: La artroplastía total de cadera (ATC) puede causar una pérdida considerable de sangre. Para reducir la necesidad de transfusión de sangre se utilizan diversas técnicas preoperatorias como la administración de ácido tranexámico (ATX). OBJETIVO: Demostrar que el uso de ATX disminuye la necesidad de transfusión de sangre alogénica en pacientes operados de ATC. MATERIAL Y MÉTODOS: estudio prospectivo, observacional, descriptivo, utilizado para observar la tasa de transfusión de sangre alogénica en pacientes a quienes se les practicó ATC primaria unilateral de Mayo de 2016 a Diciembre de 2017. A los pacientes incluidos en el estudio se les aplicó ATX preoperatoriamente, a las 24 horas se tomó una biometría hemática y se valoró la necesidad de transfusión sanguínea. RESULTADOS: Se incluyó un total de 70 pacientes en el estudio. La Hb promedio postquirúrgica 11.7 mg/dl con un rango de 9.2 a 14.9 mg/dl y un Hto promedio de 37.1% con un rango de 30.2 a 44.2%. Ninguno de los pacientes requirió de transfusión de sangre alogénica. CONCLUSIONES: En este estudio se demuestra cómo el ATX es una estrategia transoperatoria para reducir la necesidad de transfusión de sangre alogénica en pacientes a quienes se realiza una ATC primaria.

Alergia alimentaria a maní: conceptos clínicos, diagnósticos y terapéuticos / Food allergy to peanuts: clinical, diagnostic and therapeutic concepts

The prevalence of food allergy (FA) is about 2-8 percent, with clinical manifestations ranging from localized symptoms, to severe anaphylactic reactions. FA is generally caused by milk, eggs, soybeans, tree nuts, peanuts, wheat, fish and crustacean; being peanut one of the main foods involved in Western countries. Although in other parts of the world peanut allergy (PA) is not a problem, probably due to timing of introduction into the diet, form and preparation, genetics, and the hygiene hypothesis. Unfortunately, in Chile there are no epidemiological data about FA or PA. A number of food allergens have been identified, which has improved patient diagnosis and treatment assessment. Regarding peanut, 9 allergens have been identified, Ara h 1 to Ara h 9 (Arachis hypogaea). The diagnosis of IgE-mediated PA is based on a consistent history and evidence of peanut-specific IgE sensitization, carried out by skin-prick testing or in vitro determination. PA treatment consists of peanuts avoidance, which often becomes difficult due to inadvertent consumption. Today promising treatments are under development, including oral induction tolerance or sublingual immunotherapy. These treatments offer the possibility of at least raising the threshold of the amount of peanut that would be necessary to cause a life-threatening allergic reaction.

Biological dosimetry intercomparison exercise: an evaluation of triage and routine mode results by robust methods.

Well-defined protocols and quality management standards are indispensable for biological dosimetry laboratories. Participation in periodic proficiency testing by interlaboratory comparisons is also required. This harmonization is essential if a cooperative network is used to respond to a mass casualty event. Here we present an international intercomparison based on dicentric chromosome analysis for dose assessment performed in the framework of the IAEA Regional Latin American RLA/9/054 Project. The exercise involved 14 laboratories, 8 from Latin America and 6 from Europe. The performance of each laboratory and the reproducibility of the exercise were evaluated using robust methods described in ISO standards. The study was based on the analysis of slides from samples irradiated with 0.75 (DI) and 2.5 Gy (DII). Laboratories were required to score the frequency of dicentrics and convert them to estimated doses, using their own dose-effect curves, after the analysis of 50 or 100 cells (triage mode) and after conventional scoring of 500 cells or 100 dicentrics. In the conntional scoring, at both doses, all reported frequencies were considered as satisfactory, and two reported doses were considered as questionable. The analysis of the data dispersion among the dicentric frequencies and among doses indicated a better reproducibility for estimated doses (15.6% for DI and 8.8% for DII) than for frequencies (24.4% for DI and 11.4% for DII), expressed by the coefficient of variation. In the two triage modes, although robust analysis classified some reported frequencies or doses as unsatisfactory or questionable, all estimated doses were in agreement with the accepted error of ±0.5 Gy. However, at the DI dose and for 50 scored cells, 5 out of the 14 reported confidence intervals that included zero dose and could be interpreted as false negatives. This improved with 100 cells, where only one confidence interval included zero dose. At the DII dose, all estimations fell within ±0.5 Gy of the reference dose interval. The results obtained in this triage exercise indicated that it is better to report doses than frequencies. Overall, in both triage and conventional scoring modes, the laboratory performances were satisfactory for mutual cooperation purposes. These data reinforce the view that collaborative networking in the case of a mass casualty event can be successful.

Etiopatogenia de la esclerosis sistémica progresiva / Etiopathogenesis of systemic sclerosis

La esclerosis sistémica progresiva (ESP) es una enfermedad autoinmune crónica del tejido conectivo. Se caracteriza por una alteración vascular inicial, una respuesta inmune alterada con producción de autoanticuerpos y un exceso de síntesis y depósito de fibras de colágeno en la piel y tejido conectivo. La activación y el daño endotelial son eventos tempranos en la patogenia de la enfermedad; sin embargo, el factor gatillante continúa siendo desconocido. Se piensa que el evento principal sería la interacción entre eventos autoinmunes y cambios vasculares tempranos, lo cual resulta en la generación de fibroblastos activados considerados como las células efectoras de la enfermedad. Se reconocen dos subgrupos clínicos de ESP: la variedad cutánea limitada y la variedad cutánea difusa, las cuales presentan distintos patrones de compromiso orgánico, autoanticuerpos, evolución y sobrevida.

Progressive systemic sclerosis is a chronic autoimmune disease of connective tissue. It is characterized by early vascular changes, altered immune response with production of auto-antibodies, and excessive synthesis and deposition of collagen fibers in the skin and connective tissue. Activation and endothelial cell damage are early events in the pathogenesis of the disease, but the precise triggering event(s) remain elusive. The main event would be the interaction between autoimmune events early vascular changes, resulting in the generation of activated fibroblasts, regarded as effector cells of the disease. There are two major subgroups of SSc, the limited cutaneous and the diffuse cutaneous variety, which have distinct patterns of organ involvement, self-auto-antibodies, evolution and survival.

Investigación de Estreptococos fecales en aguas del arroyo Zaimán / Isolation of fecal streptococci in Zaiman creek waters

Se investigó la presencia de las distintas especies y biovariedades de estreptococos fecales en aguas del arroyo Zaimán, cuya cuenca hídrica comprende importantes zonas de la ciudad de Posada, Misiones. Las muestras fueron extraídas en zonas aledañas cercanas a un establecimiento de la industria de la carne, que vierte sus efluentes en el citado cruso de aguas. Se efectuaron 18 operaciones de muestreo en puntos geográficos representativos. La metodología seguida para la detección y caracterización de las especies presentes consistió en una etapa de enriquecimiento en caldo azida dextrosa, con posteriores repiques en placas de agar KF y agar kanamicina-esculina-azida. El estudio bioquímico de las colonias desarrolladas en medio agar cerebro corazón, se llevó a cabo de acuerdo a normas de estándares americanos de aguas. Las especies de mayor frecuencia de aislamiento resultaron ser: S. faecalis V. liquefaciens (48%), S. faecalis (20%), y S. durans (14%). La distribución de estreptococos fecales por puntos de muestreo indica que la contaminación proviene no sólo del vertido de efluentes, sino tambíen del asentamiento poblacional cercano al curso de aguas

Investigación de Estreptococos fecales en aguas del arroyo Zaimán / Isolation of fecal streptococci in Zaiman creek waters

Se investigó la presencia de las distintas especies y biovariedades de estreptococos fecales en aguas del arroyo Zaimán, cuya cuenca hídrica comprende importantes zonas de la ciudad de Posada, Misiones. Las muestras fueron extraídas en zonas aledañas cercanas a un establecimiento de la industria de la carne, que vierte sus efluentes en el citado cruso de aguas. Se efectuaron 18 operaciones de muestreo en puntos geográficos representativos. La metodología seguida para la detección y caracterización de las especies presentes consistió en una etapa de enriquecimiento en caldo azida dextrosa, con posteriores repiques en placas de agar KF y agar kanamicina-esculina-azida. El estudio bioquímico de las colonias desarrolladas en medio agar cerebro corazón, se llevó a cabo de acuerdo a normas de estándares americanos de aguas. Las especies de mayor frecuencia de aislamiento resultaron ser: S. faecalis V. liquefaciens (48%), S. faecalis (20%), y S. durans (14%). La distribución de estreptococos fecales por puntos de muestreo indica que la contaminación proviene no sólo del vertido de efluentes, sino tambíen del asentamiento poblacional cercano al curso de aguas (AU)

[Fecal Streptococci in the waters of the Zaiman stream]. / Investigación de estreptococos fecales en aguas del arroyo Zaimán.

The investigation was focused on the occurrence of different species and biovarieties of fecal streptococci in Zaiman creek waters, the basin of which comprises important zones of Posadas, Misiones. The samples were collected from points near a meat-packing industrial establishment which pours its effluents in the above mentioned water course. So far, 18 sampling operations have been carried out in representative geographic locations. The methodology followed for detecting and characterizing the present species consisted in an enrichment procedure performed by incubating samples in Azida Dextrose broth at 35 degrees C during 24-48 h. Further streaks were made on KF Agar and Kanamycin Agar plates. The biochemical study of the colonies developed in Brain Heart Agar media was the one described in the American Water Standards (APHA and EPA). The isolation frequency of the different species of fecal streptococci is shown. (Table 2). The efficiency of both culture media KF Agar and Kanamycin Aesculin Azide Agar proved to be similar. (Table 1). The distribution of fecal streptococci by sampling points shows that the pollution comes not only from the pourings of effluents but also from the population settlement near the water course.

Investigación de estreptococos fecales en aguas del arroyo Zaimán. / [Fecal Streptococci in the waters of the Zaiman stream]

The investigation was focused on the occurrence of different species and biovarieties of fecal streptococci in Zaiman creek waters, the basin of which comprises important zones of Posadas, Misiones. The samples were collected from points near a meat-packing industrial establishment which pours its effluents in the above mentioned water course. So far, 18 sampling operations have been carried out in representative geographic locations. The methodology followed for detecting and characterizing the present species consisted in an enrichment procedure performed by incubating samples in Azida Dextrose broth at 35 degrees C during 24-48 h. Further streaks were made on KF Agar and Kanamycin Agar plates. The biochemical study of the colonies developed in Brain Heart Agar media was the one described in the American Water Standards (APHA and EPA). The isolation frequency of the different species of fecal streptococci is shown. (Table 2). The efficiency of both culture media KF Agar and Kanamycin Aesculin Azide Agar proved to be similar. (Table 1). The distribution of fecal streptococci by sampling points shows that the pollution comes not only from the pourings of effluents but also from the population settlement near the water course.