Fisiología respiratoria: el control de la respiración / Respiratory fisiology: the breath control

El control de la respiración comprende un componente automático involuntario y un componente voluntario, con centros de control en el tronco encefálico, principalmente en la médula oblonga y en el puente, y en la corteza cerebral. Estos centros reciben aferencias provenientes de sensores que detectan señales químicas y no químicas, interactúan entre sí y generan respuestas que llegan a las neuronas motoras inferiores a nivel de médula espinal. Estos procesos determinan el funcionamiento de los músculos implicados en la respiración, y de ese modo permite garantizar que los niveles de pO2 p CO2 y pH en la sangre arterial se mantengan en forma óptima, frente a diferentes situaciones y demandas metabólicas. Se hace una revisión actualizada del tema que permita comprender estos procesos.

The control of breathing comprises an involuntary automatic component and a voluntary component, with control centers in the brain stem, mainly in the medulla oblongata and in the bridge, and in the cerebral cortex. These centers receive afferences from sensors that detect chemical and non-chemical signals, interact with each other and generate responses that reach the lower motor neurons at the spinal cord level. These processes determine the functioning of the muscles involved in breathing, and thus ensure that the levels of pO2 p CO2 and pH in arterial blood are optimally maintained, in the face of different situations and metabolic demands. An up-to-date review of the subject is carried out to understand these processes.

[Sudden unexpected death in infancy: Update and preventive measures]. / Muerte súbita inesperada en la infancia: Actualización y medidas de prevención.

Sudden unexpected death in infancy (SUDI) - defined as the death of a child under 1 year of age du ring sleep with no initially obvious cause - remains one of the most common causes of post-neonatal mortality. Approximately 3,500 infants die annually in the United States from sleep-related deaths. A complex and multifactorial origin is postulated in a vulnerable infant. However, the pathophysiology of SUDI has not been fully understood. Health care providers play a key role in promoting preventive measures described in the literature, which include sleeping in a supine position on a firm surface, avoiding smoking and co-sleeping, promoting breastfeeding, among others. The objective of this re view is to summarize the main epidemiological and physiopathological characteristics of SUDI, and safe sleep-related factors.

Nuevo coronavirus (COVID-19) en población general y pediátrica: una revisión epidemiológica: Chile 2020 / Novel coronavirus (COVID-19) in general and pediatric population: an epidemiological review: Chile 2020

Since December 2019, the outbreak of a novel coronavirus SARS Cov-2 has been reported in Wuhan, China. Currently, the new coronavirus disease has been declared a worldwide pandemic. Compared to adults, reporting of cases in pediatric patients has been significant smaller. The objective of this article is to provide epidemiological information of COVID-19, especially pediatric. Most of the confirmed cases of children are declared to be a cluster disease. The clinic is oligosymptomatic, less severe and with concentrated risk in children under 1 year of age and with comorbidity. In Chile, pediatric patients represent about 6% of the total number of infected and overall lethality is significantly lower than adults. The main control measures to reduce effective reproduction are mass testing, social distancing and school closure, without dismissing individual responsibility. The adequate supply of personal protection elements is key to avoid nosocomial infection and the compromise of healthcare providers.

A partir de diciembre del 2019, se ha reportado el brote de una nueva infección por SARS Cov-2 en Wuhan, China. Actualmente, la enfermedad por el nuevo coronavirus 2019 ha alcanzado el estatus de pandemia. El reporte de casos en pacientes pediátricos ha sido escaso. El objetivo de este artículo es entregar información epidemiológica del COVID-19, especialmente pediátrica. Los niños han presentado enfermedad en clusters, secundaria a contacto con parientes enfermos. La clínica es oligosintomática, menos severa y mayor riesgo concentrado en menores de 1 año y con comorbilidad. En Chile, los pacientes pediátricos representan cerca del 6% del total y la letalidad global es notablemente más baja que en adultos. Las principales medidas de control para la reducción de la reproducción efectiva son el testeo masivo, distanciamiento social y cierre escolar, sin desestimar la responsabilidad individual. El adecuado abastecimiento de elementos de protección personal es clave para evitar la infección nosocomial y del personal de salud.

International expert consensus on the management of allergic rhinitis (AR) aggravated by air pollutants: Impact of air pollution on patients with AR: Current knowledge and future strategies.

Allergic rhinitis affects the quality of life of millions of people worldwide. Air pollution not only causes morbidity, but nearly 3 million people per year die from unhealthy indoor air exposure. Furthermore, allergic rhinitis and air pollution interact. This report summarizes the discussion of an International Expert Consensus on the management of allergic rhinitis aggravated by air pollution. The report begins with a review of indoor and outdoor air pollutants followed by epidemiologic evidence showing the impact of air pollution and climate change on the upper airway and allergic rhinitis. Mechanisms, particularly oxidative stress, potentially explaining the interactions between air pollution and allergic rhinitis are discussed. Treatment for the management of allergic rhinitis aggravated by air pollution primarily involves treating allergic rhinitis by guidelines and reducing exposure to pollutants. Fexofenadine a non-sedating oral antihistamine improves AR symptoms aggravated by air pollution. However, more efficacy studies on other pharmacological therapy of coexisting AR and air pollution are currently lacking.

[Vitamin D and pediatrics respiratory diseases]. / Vitamina D y enfermedades respiratorias pediátricas.

The better understanding of the global activity of vitamin D has led to an intense search for its involvement in non-skeletal diseases. This article presents an updated review of the relationship between vitamin D and pediatric respiratory pathology. A literature search was performed in PUBMED using free terms and MESH terms: vitamin D, asthma, respiratory system diseases, and bronchiolitis. Stu dies in human patients younger than 18 years and animals, published in English and Spanish until 2017 were included. 507 articles were found, of which 43 were included. Indirect evidence suggests a role of vitamin D and fetal lung maturation. In relation to pediatric pulmonary pathology, studies are scarce and inconclusive. Recent meta-analyses performed with individualized evaluation of the participants shows an important protective role of vitamin D supplementation in the prevention of severe asthma exacerbations and acute viral infections. In bronchiolitis, the results are contradictory, with no clear relationship between plasma levels and severity. There is not enough evidence to assess the benefits of vitamin D supplementation in cystic fibrosis and tuberculosis. A direct relationship between the severity of sleep-related breathing disorders and vitamin D plasma levels has recently been proposed, although the exact mechanisms involved in this association are unknown. Current information suggests that vitamin D supplementation may represent a cost-effective strategy in redu cing important causes of infant morbidity and mortality.

Vitamina D y enfermedades respiratorias pediátricas / Vitamin D and pediatrics respiratory diseases

Resumen: El mejor entendimiento sobre la actividad global de la vitamina D, ha llevado a una intensa búsque da de sus implicancias en enfermedades no esqueléticas. En este artículo se presenta una revisión actualizada de la relación entre la vitamina D y la patología respiratoria pediátrica. Se realizó una búsqueda bibliográfica en PUBMED utilizando términos libres y MESH: vitamina D, enfermedades del sistema respiratorio, asma, bronquiolitis. Se seleccionó estudios en humanos menores de 18 años y animales, publicados en inglés y español hasta el 2017. Se encontraron 507 artículos, de los cuales se incluyeron 43. Evidencia indirecta apunta hacia un rol de la vitamina D y la maduración pulmonar fetal. En relación a la patología pulmonar pediátrica, los estudios son escasos y poco concluyentes. Nuevos meta - análisis, con evaluación individualizada de los participantes, muestran un importante rol protector de la suplementación en la prevención de exacerbaciones asmáticas severas e infecciones virales agudas. En bronquiolitis los resultados son contradictorios, sin relación clara entre niveles plasmáticos y severidad. No existe suficiente evidencia que evalué los beneficios en fibrosis quística y tuberculosis. Recientemente se ha propuesto una relación directa entre la severidad de los trastornos respiratorios del sueño y los niveles plasmáticos de vitamina D, aunque se desconoce los mecanismos exactos involucrados a esta asociación. La información actual permite suponer que la suplementación de vitamina D puede representar una estrategia costo - efectiva en la reducción de importantes causas de morbimortalidad infantil.

Abstract: The better understanding of the global activity of vitamin D has led to an intense search for its involvement in non-skeletal diseases. This article presents an updated review of the relationship between vitamin D and pediatric respiratory pathology. A literature search was performed in PUBMED using free terms and MESH terms: vitamin D, asthma, respiratory system diseases, and bronchiolitis. Stu dies in human patients younger than 18 years and animals, published in English and Spanish until 2017 were included. 507 articles were found, of which 43 were included. Indirect evidence suggests a role of vitamin D and fetal lung maturation. In relation to pediatric pulmonary pathology, studies are scarce and inconclusive. Recent meta-analyses performed with individualized evaluation of the participants shows an important protective role of vitamin D supplementation in the prevention of severe asthma exacerbations and acute viral infections. In bronchiolitis, the results are contradictory, with no clear relationship between plasma levels and severity. There is not enough evidence to assess the benefits of vitamin D supplementation in cystic fibrosis and tuberculosis. A direct relationship between the severity of sleep-related breathing disorders and vitamin D plasma levels has recently been proposed, although the exact mechanisms involved in this association are unknown. Current information suggests that vitamin D supplementation may represent a cost-effective strategy in redu cing important causes of infant morbidity and mortality.

Broncomalacia del adulto: entidad no tan infrecuente que mejora con presión positiva continua de la vía aérea / Bronchomalacia in adults: an infrequent entity that improves with continuous positive pressure on the airway

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¿Existe correlación clínica o radiológica a la existencia de inflamación detectable histológicamente en el disco lumbar herniado? Resultados de una serie consecutiva de pacientes operados de hernia discal lumbar / Is there a clinical or radiological correlate to the histological evidence of an inflammatory infiltrate in the herniated disc? Results of a consecutive series of patients surgically treated of herniated lumbar disc

Objetivo: Establecer la relevancia clínica de la presencia de infiltrados de células inflamatorias evidenciables histológicamente en muestras de hernias de disco lumbares operadas. Material y método: Se obtuvieron muestras de discos lumbares de 50 pacientes operados de forma consecutiva durante el año 2012. Se recogieron los datos clínicos y epidemiológicos de los pacientes antes de la cirugía, el tiempo de evolución de los síntomas, así como la presencia de radiculopatía, déficits neurológicos y la exploración. Se estableció el carácter extruido o contenido de la hernia en RM. Se estableció la presencia y cuantía de celularidad condrocitaria como signo de degeneración discal. Resultados: Aunque casi todos las muestras reflejaban proliferación condrocitaria, la presencia de infiltrados inflamatorios o neovascularización fue escasa. La presencia de inflamación se relacionó invariablemente con la formación de nuevos vasos en el disco, no relacionándose con ninguna variable clínica o radiológica. Conclusión: No hay relación entre la presencia de infiltrados inflamatorios y los datos clínicos registrados. La presencia de infiltrados inflamatorios en el interior del disco herniado no tiene relación ni con la degeneración discal ni con la producción de clínica dolorosa (AU)

Objective: To establish the clinical relevance of the histological evidence of inflammatory cell infiltrates in surgical samples of operated lumbar disc hernia. Material and method: Surgical samples, clinical, and epidemiological data were obtained from 50 patients consecutively operated on of lumbar disc herniation during 2012 were obtained. Also the MR appearance as extruded or contained hernia was recorded. All samples were processed using hematoxilin-eosin staining and different histological parameters were determined such as the presence and quantity of chondrocytes present in the disc as a sign of disc degeneration. Results: Even though the majority of samples examined showed signs of disc degeneration, such as the presence of chondrocyte proliferation, the evidence of neovascularisation or inflammatory infiltrates was scarce. The presence of inflammatory infiltrates was invariably related to the presence of neovascularisation. However, the presence of inflammatory infiltrates was not related to any radiological or clinical variable. Conclusion: There is no relation between the presence of inflammatory infiltrates and the clinical data registered. The presence of histological evidence of inflammation in herniated lumbar disc tissue is not related to disc degeneration or the presence of pain (AU)

Spinal cord injury after blunt cervical spine trauma: correlation of soft-tissue damage and extension of lesion.

BACKGROUND AND PURPOSE: In patients with spinal cord injury after blunt trauma, several studies have observed a correlation between neurologic impairment and radiologic findings. Few studies have been performed to correlate spinal cord injury with ligamentous injury. The purpose of this study was to retrospectively evaluate whether ligamentous injury or disk disruption after spinal cord injury correlates with lesion length. MATERIALS AND METHODS: We retrospectively reviewed 108 patients diagnosed with traumatic spinal cord injury after cervical trauma between 1990-2011. Plain films, CT, and MR imaging were performed on patients and then reviewed for this study. MR imaging was performed within 96 hours after cervical trauma for all patients. Data regarding ligamentous injury, disk injury, and the extent of the spinal cord injury were collected from an adequate number of MR images. We evaluated anterior longitudinal ligaments, posterior longitudinal ligaments, and the ligamentum flavum. Length of lesion, disk disruption, and ligamentous injury association, as well as the extent of the spinal cord injury were statistically assessed by means of univariate analysis, with the use of nonparametric tests and multivariate analysis along with linear regression. RESULTS: There were significant differences in lesion length on T2-weighted images for anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum in the univariate analysis; however, when this was adjusted by age, level of injury, sex, and disruption of the soft tissue evaluated (disk, anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum) in a multivariable analysis, only ligamentum flavum showed a statistically significant association with lesion length. Furthermore, the number of ligaments affected had a positive correlation with the extension of the lesion. CONCLUSIONS: In cervical spine trauma, a specific pattern of ligamentous injury correlates with the length of the spinal cord lesion in MR imaging studies. Ligamentous injury detected by MR imaging is not a dynamic finding; thus it proved to be useful in predicting neurologic outcome in patients for whom the MR imaging examination was delayed.

Cojera no dolorosa como forma de presentación de una artritis tuberculosa / Painless limp as a presentation of tuberculous arthritis

La coxalgia unilateral puede representar un importante reto diagnóstico en pediatría. Aunque la causa más frecuente es la sinovitis transitoria de cadera, hay otros diagnósticos que deben tenerse en cuenta, como la artritis séptica, las formas de inicio de artritis inflamatoria, en especial las asociadas a entesitis, las enfermedades ortopédicas (Perthes y epifisiolisis de cadera) y las neoplasias (AU)

The unilateral hip pain can be a major diagnostic challenge in pediatrics. Although the most common cause is transient synovitis, there are other diagnoses that should be taken into consideration as septic arthritis, onset forms of inflammatory arthritis, especially those associated with enthesitis, orthopedic disease (Perthes and epiphysiolysis hip) and neoplasms (AU)

Allergy assessment in children with eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is of growing interest for pediatricians and allergists. There is no general agreement about diagnostic and clinical management procedures. The objective of this prospective, observational study was to evaluate the efficacy of a protocol for the etiologic diagnosis and accurate treatment of EoE in the pediatric population. PATIENTS AND METHODS: Starting in 2001, patients aged 0 to 14 years with a diagnosis of EoE were consecutively included in a protocol which included an allergy study. Depending on the results, an avoidance or elemental diet was established. Topical corticosteroids were prescribed to patients who rejected the diet. Clinical, endoscopic, and histological evaluation was performed to assess response. In the case of disease remission, challenge tests were performed to identify the offending food. RESULTS: Seventeen patients were included. Most of them were male (14/17) and a high percentage (88%) had a history of allergy as well as a history of atopy in parents. Fifteen patients were sensitized to 1 or more foods. With this protocol and the subsequent treatment, 9 out of 17 patients were cured (1 out of 4 with swallowed corticosteroids, 3 out of 3 with an elemental diet, and 5 out of 12 with an avoidance diet). The offending food was identified in 8117 patients. Milk and eggs were the most common foods implicated. CONCLUSIONS: The allergy study was a useful diagnostic tool but it was not sufficient to identify the offending food.An elemental diet should be attempted before food is excluded as the cause of the disease.

Bioactivation of aflatoxin B1 by turkey liver microsomes: responsible cytochrome P450 enzymes.

1. A study was conducted to determine the cytochrome P450 enzymes responsible for the bioactivation of aflatoxin B1 into its epoxide form (AFBO) in turkey liver microsomes. 2. The strategies used included the measurement of prototype substrate activity for specific human P450s, use of selective inhibitors, determination of correlation between aflatoxin bioactivation and enzymatic activity of prototype substrates and the determination of immunoreactive proteins using antibodies against human P450s. 3. Enzymatic activity and immunoreactive proteins corresponding to the turkey orthologs CYP1A1, CYP1A2, CYP2A6 and CYP3A4 were detected, but not for the CYP2D6 ortholog. 4. The results of the inhibition and correlation studies strongly suggest that the turkey CYP2A6 ortholog and, to a lesser extent, the CYP1A1 ortholog, are involved in the bioactivation of aflatoxin B1 in turkey liver microsomes. 5. This is the first study reporting the role of CYP2A6 in the bioactivation of AFB1 in an avian species and the role of CYP1A1 in any species.

Cytochrome P450 enzymes involved in the metabolism of aflatoxin B1 in chickens and quail.

A study was conducted to identify the cytochrome P450 (CYP, CYP450) enzyme orthologs involved in the bioactivation of aflatoxin B(1) (AFB(1)) into the highly toxic metabolite known as aflatoxin-8,9-epoxide (AFBO) in quail and chicken hepatic microsomes. The strategies used included the use of specific CYP450 inhibitors and the correlation of prototype substrate activities with AFBO production. Additionally, the presence of the enzymes was qualitatively determined using an immunoblotting technique. The results showed that both quail and chicken microsomes have CYP1A1, CYP1A2, CYP2A6, and CYP3A4 enzymatic activity. A strong relationship between CYP1A1 and CYP2A6 activities and AFB(1) bioactivation was found in both species. Inhibition studies provided more evidence for the role of CYP2A6 in the bioactivation of AFB(1). The immunoblot results showed clear bands for the CYP2A6 and CYP3A4 orthologs in both species. The results of the present study indicate that CYP2A6 and, to a lesser extent, CYP1A1 are responsible for the bioactivation of AFB(1) into AFBO in both quail and chicken hepatic microsomes.

Peritonitis secundaria a una perforación por infestación con «Ascaris lumbricoides» / Intestinal perforation with secondary peritonitis caused by Ascaris lumbricoides

La perforación intestinal y la peritonitis secundaria causada por Ascaris lumbricoides, aunque es rara en nuestro medio, debe tenerse en cuenta en los pacientes con clínica compatible procedentes de áreas endémicas. Presentamos el caso de una niña rumana con un cuadro clínico de fiebre, vómitos y dolor abdominal de 15 días de evolución, con colecciones abdominales observadas en las pruebas de imagen, en las que se aprecia una infestación por A. lumbricoides tras la cirugía laparoscópica (AU)

Intestinal perforation with secondary peritonitis caused by Ascaris lumbricoides is rare in our environment. This entity should be taken into consideration in patients who come from endemic areas, and who have suggestive clinical manifestations. We report a case of a Rumanian girl with 15 days of fever, stomach pains and vomiting. Imaging studies evidenced abdominal collections in which Ascaris lumbricoides infestation was found through laparoscopic surgery (AU)