Fisiología respiratoria: mecanismos de defensa del sistema respiratorio / Defense mechanisms of the respiratory system

El sistema respiratorio cumple múltiples funciones no respiratorias, entre ellas es fundamental su rol en la defensa del organismo frente a una gran variedad de agentes externos potencialmente nocivos. Para ello, cuenta con mecanismos de protección de la vía aérea, dado por sus estructuras anatómicas, reflejos y el transporte mucociliar, además de un complejo y amplio desarrollo del sistema inmune pulmonar. El objetivo de este articulo es revisar los conceptos y componentes más importantes de función defensiva del sistema respiratorio.

The respiratory system fulfills multiple non-respiratory functions, including its role in defending the body against a wide variety of potentially harmful external agents. For this, it has airway protection mechanisms, given by its anatomical structures, reflexes and mucociliary transport, as well as a complex and extensive development of the pulmonary immune system. The objective of this article is to review the most important concepts and components of the defensive function of the respiratory system.

Evidence-based anti-viral and immunomodulatory potential of Black cumin (Nigella sativa L) in COVID-19 / Potencial antivírico e inmunomodulador en COVID-19 del comino negro (Nigella sativa L) basado en la evidencia

Currently, the whole world is facing a life-threatening novel coronavirus 2019 (COVID-19) pandemic. Natural products are well-known for their potential role against viral disease, and some anti-viral agents have been developed to combat these diseases. Herein, the authors investigated the possible effects of this Holy plant Nigella sativa L. (NS), against coronavirus, using evidence-based and mechanistic approaches to conclude the immune-boosting and alleviation of respiratory systemeffects of NS. The pharmacological studies established a prominent role in treating various respiratory, immune systems, cardiovascular, skin, and gastrointestinal disorders. Literature supported the significant anti-viral role and showed an inhibitory role for NS against MHV-A59 CoV (mouse-hepatitis virus­A59) infected Hela, i.e., HeLaCEACAM1a (HeLa-epithelial carcinoembryonic antigen-related cell adhesion molecule 1a) cell. NS is a safe herbal product or dietary supplement and could be an effective and affordable community adjuvant treatment for coronavirus in the current scenario.

Actualmente, el mundo entero se enfrenta a una pandemia del nuevo coronavirus 2019 (COVID-19) que amenaza la vida. Los productos naturales son bien conocidos por su papel potencial contra las enfermedades virales, y se han desarrollado algunos agentes antivirales para combatir estas enfermedades. En este documento, los autores investigaron los posibles efectos de esta planta sagrada Nigella sativa L. (NS), contra el coronavirus, utilizando enfoques mecanicistas y basados en la evidencia para concluir el refuerzo inmunológico y el alivio de los efectos del SN en el sistema respiratorio. Los estudios farmacológicos establecieron un papel destacado en el tratamiento de diversos trastornos respiratorios, del sistema inmunológico, cardiovasculares, cutáneos y gastrointestinales. La literatura apoyó el importante papel antivírico y mostró un papel inhibidor de NS contra células Hela infectadas con MHV-A59 CoV (virus de la hepatitis de ratón-A59), es decir, HeLaCEACAM1a (molécula de adhesión celular 1a relacionada con el antígeno carcinoembrionario epitelial de HeLa). NS es un producto a base de hierbas o un suplemento dietético seguro y podría ser un tratamiento adyuvante comunitario eficaz y asequible para el coronavirus en el escenario actual.

Determinants of peak VO2 in heart transplant recipients / Determinantes do pico de VO2 em transplantados cardíacos

Objective: To establish the determinants of the peak VO2 in heart transplant recipients. Methods: Patient's assessment was performed in two consecutive days. In the first day, patients performed the heart rate variability assessment followed by a cardiopulmonary exercise test. In the second day, patients performed a resting echocardiography. Heart transplant recipients were eligible if they were in a stable condition and without any evidence of tissue rejection diagnosed by endomyocardial biopsy. Patients with pacemaker, noncardiovascular functional limitations such as osteoarthritis and chronic obstructive pulmonary disease were excluded from this study. Results: Sixty patients (68% male, 48 years and 64 months following heart transplantation) were assessed. Multivariate analysis selected the following variables: receptor's gender (P=0.001), receptor age (P=0.049), receptor Body Mass Index (P=0.005), heart rate reserve (P <0.0001), left atrium diameter (P=0.016). Multivariate analysis showed r=0.77 and r2=0.6 with P <0.001. Equation: peakVO2=32.851 - 3.708 (receptor gender) - 0.067 (receptor age) - 0.318 (receptor BMI) + 0.145 (heart rate reserve) - 0.111 (left atrium diameter). Conclusion: The determinants of the peak VO2 in heart transplant recipients were: receptor sex, age, Body Mass Index, heart rate reserve and left atrium diameter. Heart rate reserve was the unique variable positively associated with peak VO2. This data suggest the importance of the sympathetic reinnervation in peak VO2 in heart transplant recipients. .

Objetivo: Estabelecer os determinantes do VO2 pico em transplantados de coração. Métodos: Avaliação do paciente foi realizada em dois dias consecutivos. No primeiro dia, os pacientes realizaram a avaliação da variabilidade da frequência cardíaca seguida de um teste de esforço cardiopulmonar. No segundo dia, os pacientes realizaram ecocardiografia de repouso. Os transplantados foram elegíveis se estivessem em uma condição estável e sem qualquer evidência de rejeição diagnosticada por biópsia endomiocárdica. Pacientes com marca-passo, limitações funcionais não cardiovasculares, tais como osteoartrite e doença pulmonar obstrutiva crônica foram excluídos deste estudo. Resultados: Sessenta pacientes (68% do sexo masculino, 48 anos e 64 meses após o transplante cardíaco) foram avaliados. A análise multivariada selecionou as seguintes variáveis: sexo (P=0,001), idade (P=0,049), Índice de Massa Corporal (P=0,005), frequência cardíaca de reserva (P <0,0001), diâmetro do átrio esquerdo (P=0,016), variáveis do receptor. A análise multivariada mostrou r=0,77 e r2=0,6, com P <0,001. Equação: VO2=32,851 - 3,708 (sexo receptor) - 0,067 (idade receptor) - 0,318 (IMC receptor) + 0,145 (frequência cardíaca de reserva) - 0,111 (diâmetro de átrio esquerdo). Conclusão: Os determinantes do pico de VO2 em transplantados de coração foram: sexo receptor, idade, Índice de Massa Corporal, frequência cardíaca de reserva e diâmetro do átrio esquerdo. A frequência cardíaca de reserva foi a única variável positivamente associada com o pico de VO2. Estes dados sugerem a importância da reinervação simpática no pico de VO2 em transplantados de coração. .

Efeitos do estresse da orquiectomia na citologia broncoalveolar de bezerros da raça Holandesa / Effects of the stress of orchectomy on bronchoalveolar citology of Holstein Calves

A identificação do impacto que certas formas de estresse causam ao bem estar animal e equilíbrio orgânico, representa um desafio á adoção de boas práticas de criação. Assim, a presente pesquisa verificou o impacto de um desafio doloroso rotineiro dos bovinos na imunidade pulmonar e sistêmica. Avaliou-se hemograma e cortisol, em quatro momentos, sendo M1, M6, M7 e M8 (respectivamente sete dias antes e um, três e oito dias depois do desafio doloroso) e citologia broncolaveolar, obtida por broncoscopia, nos momentos M1, M6 e M8. Houve uma redução dos valores do eritrograma no primeiro dia após o desafio, compatível com anaplasmose e agravada pela perda de sangue durante a cirurgia e um influxo de leucócitos para a região pulmonar. Oito dias após o desafio, evidenciou-se aumento de cortisol, gerando uma leucocitose por neutrofilia e monocitose no sangue com provável redução de quimiotaxia para o pulmão, tornando o trato respiratório potencialmente mais susceptível a infecções, sugerindo que esta prática de manejo, mesmo acompanhado de protocolo analgésico, pode ser considerada um fator de risco a penumonias afetando o bem estar animal.

The recognition of the impact of certains forms of stress in the animal well being and organic equilibrium, represents a challenge to the adoption of good practices. Thus, this research verified the impact of a painful rotine of the cattle husbandry can cause on pulmonary and systemic immunity. Was evaluated hemogram and cortisol, in four moments, being M1, M6, M7 e M8 (respectively seven days before and one, three and eight days after the painful challenge) and bronchoalveolar cytology,obtained by bronchoscopy, in the moments of M1, M6 e M8. There was a reduction of the erythrogram values in the first day after the challenge, compatible with the anaplasmosis and aggravated by the blood loss during the surgery and an influx of leukocytes to the pulmonary region. Eight days after the challenge, became evident the cortisol increase, enerating leukocytosis by neutrophilia and monocytosis in the blood with a probable reduction of chemotaxis to the lungs, turning the respiratory tract potentially more susceptible to infections, suggesting that this practice, even accompanied by analgesic protocol, increases the risk of pneumonia, affecting the animal well-being.

Comparative Quantitative and Qualitative Attributes of the Surface Respiratory Macrophages in the Domestic Duck and the Rabbit / Atributos Cualitativos, Cuantitativos y Comparativos de los Macrófagos de la Superficie Respiratoria en el Pato Doméstico y el Conejo

In mammals, surface respiratory macrophages (SM) are known to play a foremost role in protecting the respiratory system by providing first line of defense through engulfing pathogens and particulate matter respired with air. It has been reported that the pulmonary cellular defense system of domestic birds is inadequate. In particular, low number of SM and even lack of the cells in a healthy avian respiratory system have been associated with susceptibility of domestic birds to respiratory diseases. In an endeavor to resolve the existing controversy, the quantitative and qualitative attributes of the surface respiratory macrophages of the domestic duck and of the domestic rabbit were compared under similar experimental conditions. Quantitatively, the rabbit SM were on average approximately fourteen times more than the duck SM. The SM were found to have comparable diameters measuring about 12 µm in the duck and 13 µm in the rabbit. Similarly, the duck and the rabbit SM were structurally similar. Typically, they were round granular cells possessing filopodial extensions and variable electron dense bodies in the cytoplasm. The phagocytic capacity measured using polystyrene particles revealed that the duck SM had a higher phagocytic capacity than the rabbit SM. The volume density of the engulfed polystyrene particles, i.e. the volume of the particles per unit volume of the cell was estimated at 20 percent in the duck and 9 percent in the rabbit. These results suggest that the comparatively low numbers of SM in domestic birds may contribute to susceptibility of the birds to diseases. However, given the high phagocytic capacity of the avian SM, susceptibility of the domestic birds may not be due to dearth of the SM alone but some other factor (s) such as persistent exposure of the birds to particulate matter which is known to reduce robustness of the SM may be involved.

En los mamíferos, los macrófagos de la superficie respiratoria (SM) son conocidos por jugar el papel más importante en la protección del sistema respiratorio, proporcionando la primera línea de defensa en contra de agentes patógenos y envolviendo las partículas de aire respirado. Se ha informado que el sistema de defensa celular pulmonar de las aves domésticas es insuficiente. En particular, el bajo número de SM, e incluso las células del sistema respiratorio de las aves domésticas, en un ambiente sano, se ha asociado con susceptibilidad a enfermedades respiratorias. En un esfuerzo para resolver la controversia existente, los atributos cuantitativos y cualitativos de los macrófagos de la superficie respiratoria del pato doméstico y el conejo doméstico fueron comparados en las mismas condiciones experimentales. Cuantitativamente, los SM del conejo fueron en promedio aproximadamente catorce veces más que los SM en el pato. Los SM se encontraron con un diámetro comparable, al medir alrededor de 12 micras en el pato y 13 micras en el conejo. Del mismo modo, en el pato y el conejo los SM eran estructuralmente similares. Por lo general, correspondieron a células granulares con extensiones filopodiales y organismos electrodensos variables en el citoplasma. La capacidad fagocítica medida utilizando partículas de poliestireno reveló que los SM del pato tenían una mayor capacidad fagocítica que el conejo. La densidad de volumen de las partículas de poliestireno envueltas, es decir, el volumen de las partículas por unidad de volumen se estimó en 20 por ciento en el pato y 9 por ciento en el conejo. Estos resultados sugieren que el número comparativamente bajo de los SM en las aves domésticas puede contribuir a su susceptibilidad a enfermedades. Sin embargo, dada la alta capacidad fagocítica de los SM aviares, la susceptibilidad de las aves domésticas no puede deberse solamente a la escasez de SM, sino a algunos otros factores pueden estar involucrados, como la exposición persistente de las aves a partículas, las cuales se sabe reducen la robustez de los SM.

Impact of domestic air pollution from cooking fuel on respiratory allergies in children in India.

This study undertaken in India was aimed at identifying the effects of the indoor air pollutants SO2, NO2 and total suspended particulate mater (SPM) generated from fuel used for cooking on respiratory allergy in children in Delhi. A total of 3,456 children were examined (59.2% male and 40.8% female). Among these, 31.2% of the children's families were using biomass fuels for cooking and 68.8% were using liquefied petroleum gas. Levels of indoor SO2, NO2 and SPM, measured using a Handy Air Sampler (Low Volume Sampler), were 4.60 +/- 5.66 microg/m3, 30.70 +/- 23.95 microg/m3 and 705 +/- 441.6 microg/m3, respectively. The mean level of indoor SO2 was significantly higher (p = 0.016) for families using biomass fuels (coal, wood, cow dung cakes and kerosene) for cooking as compared to families using LP gas. The mean level of indoor NO2 for families using biomass fuels for cooking was significantly higher in I.T.O. (p = 0.003) and Janakpuri (p = 0.007), while indoor SPM was significantly higher in Ashok Vihar (p = 0.039) and I.T.O. (p = 0.001), when compared to families using LP gas. Diagnoses of asthma, rhinitis and upper respiratory tract infection (URTI) were made in 7.7%, 26.1% and 22.1% of children, respectively. Respiratory allergies in children, which included asthma, rhinitis and URTI, could be associated with both types of fuels (liquefied petroleum gas [LPG] and biomass) used for cooking in the different study areas. This study suggests that biomass fuels increased the concentrations of indoor air pollutants that cause asthma, rhinitis and URTI in children. LP gas smoke was also associated with respiratory allergy.

Incidence of anaphylaxis in the emergency department: a 1-year study in a university hospital.

The aim of this study was to estimate the incidence of anaphylaxis in an emergency department, identify rate and risk factors of recurrent anaphylaxis, and describe its clinical features and management. A retrospective study of patients who attended the emergency department at Thammasat University Hospital was conducted during 2003-2004 with anaphylactically related ICD-9 and ICD-10 terms. There were 64 patients who experienced 65 anaphylactic episodes during the 1-year period. The anaphylaxis occurrence rate was 223 per 100,000 patients per year. The most common manifestations were cutaneous symptoms and signs, followed by respiratory expression. Food allergy was the most common cause of anaphylaxis. Eighty-five percent of admitted cases had monophasic anaphylaxis. Patients with and without biphasic reactions did not differ significantly in terms of epinephrine and steroid usage. In conclusion, anaphylaxis is not rare. Epinephrine and steroid usage did not prevent biphasic reactions.

Aspectos fisiopatológicos / Physiopathological aspects

Durante los últimos 20 años, grandes estudios de la labilidad de la vía aérea en asma se han desarrollado, para entender mejor los diferentes mediadores y las células involucradas en la patogenia de esta condición crónica. La composición del cuadro es que es una compleja enfermedad, que afecta a sujetos diferentes y en tiempos distintos. En niños, la inflamación crónica puede ser responsable de cambios irreversibles de la función y estructura de la vía aérea, que puede agravar más tarde la expresión clínica de la enfermedad.

1-Hydroxypyrene and interleukin-8 for biological monitoring of vehicle exhaust exposure and effects among gas-station workers

Air pollution encountered in many towns and cities throughout the world is associated with high levels of fuel vapors and motor vehicle-generated exhaust. A consistent association was reported between the levels of particulate matter and semi-volatile organic compounds in the ambient air with increasing mortality and morbidity. Although the epidemiological evidence is strong, there are yet neither established biological mechanisms to explain the toxicity in humans nor biologically established biomarkers for both exposure and severity of disease. This study was done to determine the impact of vehicle exhaust on the human airways among extensively exposed workers in few gas stations. The extent of exposure to polycyclic aromatic hydrocarbons [PAHs] is measured by estimating the level of 1-hydroxypyrene [1-OHP], a pyrene metabolite. Respiratory inflammation is clinically assessed and evaluated using pulmonary function tests. The impact of respired vehicle exhaust on the immunobiology of the respiratory system is evaluated by estimating the level of the cytokine interleukin-8 [IL-8] in serum, being used as an indication for respiratory inflammation and tissue damage. The study population consisted of 34 highway gas-station workers exposed to vehicle exhaust and 30 matched non-exposed office workers. The exposed population was further subdivided into a fueling group [n=22] working in petrol filling of cars and a car washing group [n=12] working in car cleaning. The study population was subjected to thorough clinical examination, pulmonary function testing and laboratory investigations. Measurement of the urinary 1-OHP level was done using the high performance liquid chromatography [HPLC] with electrochemical water detectors. As for the cytokine IL-8, estimation was done using quantitative sandwich enzyme-linked immunosorbent assay [ELISA]. Medical history and clinical examination revealed significantly higher frequency of repeated chest infections among the exposed group [41%] than among the control subjects [6.6%]. As for chronic bronchitis, asthmatic attacks and dyspnea, the results were higher among the exposed groups but with no statistically significant difference. Ventilation function tests revealed the presence of an obstructive affection among exposed workers correlating strongly with age and smoking habits but not with the duration of exposure. The level of FEV[1] /FVC ratio correlated with the level of 1-OHP that is the PAHs biomarker of exposure [r=-0.313; P<0.01]. The urinary 1-OHP was found to be significantly higher among the exposed population, but still no significant correlation was obtained with exposure duration. The serum IL-8 level was markedly elevated among the exposed workers and significantly correlated with FEF[25%-75%] [r = -0.263; P<0.05] revealing the presence of a high risk of chronic inflammation and lung cancer. Occupational exposure of workers in the gas stations to vehicle exhaust carries an increased risk for respiratory diseases such as repeated chest infections, chronic bronchitis and asthmatic attacks as proved by the presence of dyspnea and the decrement in pulmonary functions. Alteration of the immunological responses of the respiratory epithelium should be considered bearing a risk factor for lung cancer development later on in life. Using the urinary 1-OHP level as a biomarker for exposure and the serum IL-8 level for chronic inflammation and respiratory disease severity and progression should be further evaluated. Long-term impact on the environment needs to be properly investigated in addition to the implementation of protective measures aiming at reducing the occupational exposure to diesel-related polycyclic aromatic hydrocarbons

level of tumour necrosis factor-alpha in subjects exposed to asbestos

The objective of the study is to evaluate the role of tumour necrosis factor Alpha [TNF-alpha] a in the pathogenesis of interstitial pulmonary fibrosis caused by occupational exposure to asbestos fibres by comparing its serum level in exposed versus non-exposed subjects. Twenty workers exposed to asbestos were chosen by simple random sampling and compared to a similar number of controls [unexposed to asbestos]. Both groups were subjected to history taking, clinical examination. TNF-alpha was measured in serum and correlated with possible relevant factors. Data analysis was done by SPSS computer based program. The study showed a significant increase in the level of TNF-alpha in the exposed group as compared to the controls. No correlation was found in the exposed group between the serum TNF-alpha level and respiratory symptoms, signs or disability nor with medical history. Further studies are needed to assess the use of serum TNF-alpha as an early predictor of susceptibility to the effect of asbestos. It could predict those more prone to develop asbestos-induced pulmonary injury. Anti-TNF should be assessed as a possible prevention or treatment for asbestos-induced lung injury

Validez del diagnóstico clínico de rinitis alérgica / Validity of the clinical diagnosis of allergic rhinitis

Las rinitis alérgicas son entidades frecuentemente diagnosticadas en la consulta diaria del otorrinolaringólogo, en base a los signos y síntomas de los pacientes. Sin embargo, para confirmar dicho diagnóstico se considera necesario realizar pruebas de hipersensibilidad. El presente estudio tiene por fin determinar si es válido el diagnóstico de rinitis alérgica basado exclusivamente en los signos y síntomas mas frecuentes que presentan pacientes con etiología alérgica comprobada. Los resultados del estudio señalaron que el diagnóstico clínico de rinitis alérgica tiene una sensibilidad muy alta pero una especificidad muy baja, ocasionando problemas que se sobre diagnostique esta enfermedad si no se usan las técnicas de laboratorio apropiadas

Mecanismos de defensa del aparato respiratorio / Defensive mechanisms of the respiratory tract

El aparato respiratorio debe evitar la agresión y el daño causado por vapores, gases, irritantes, partículas inorgánicas y orgánicas, alérgenos y microorganismos que ingresan con el aire inspirado. Para cumplir esta función posee mecanismos defensivos altamente especializados que comprenden factores mecánicos, reflejos y elementos humorales y celulares. El filtro nasal, la filtración aerodinámica y el transporte mucociliar representan importantes mecanismos de arrera. El estornudo, la tos y la broncoconstricción son los principales reflejos. Entre los factores humorales inespecíficos deben destacarse a lisozima, fibronectina, antiproteasas, factores de complemento y al surfactante alveolar. Además del epitelio ciliado pseudoestratificado, entre los elementos celulares de importancia en los mecanismos de defensa, deben nombrarse a los mastocitos, los polimorfonucleares neutrófilos y eosinófilos, los macrófagos alveolares y los linfocitos. La respuesta inmune con sus características de específicidad, memoria y perfeccionamiento es el nivel más especializado de defensa. En la vertiente humoral destaca la IgA secretoria que cumple funciones de neutralización, bloqueo y opnonización. Finalmente, los linfocitos T ejercen la inmunidad celular mediante citotoxicidad y liberación de linfokinas que activan a células accesorias. Todos los mecanismos descritos deben actuar en forma coordinada y regulada para lograr su objetivo y evitar el daño tisular y la infección. Existen múltiples condiciones que pueden alterar estos mecanismos defensivos y facilitar la acción de los agentes agresores

Infección respiratoria recurrente en el niño: evaluación clínica y de laboratorio / Recurrent respiratory infections in children: a clinical and laboratory

Las infecciones respiratorias constituyen la principal causa de consulta médica, y una de las dos primeras causas de morbimortalidad en menores de cinco años en los países en desarrollo. Estudios epidemiológicos han demostrado que niños preescolares contraen entre cuatro y seis infecciones respiratorias en el transcurso de un año sin que esto necesariamente implique desviación de la "normalidad". Sin embargo, el médico general y el pediatra frecuentemente se enfrentan ante el dilema de decidir si el niño que esta "siempre enfermo" por cursar una infección respiratoria recurrente (IRR), en un niño normal o tiene alguna condición predisponente. Dentro de las condiciones predisponentes de IRR en el niño se encuentran factores del hospedero (mecanismos de defensa inmenes y no inmunes), del agente infectante y/o del medio ambiente. En esta revisión se presenta un panorama general de la evaluación clínica y de laboratorio del paciente pediátrico con IRR, lo cual está al alcance y dentro de la capacidad de todo médico