ABSTRACT
INTRODUCTION: Over the past decade, there has been a heightened interest in evaluating self-efficacy among patients with coronary artery disease (CAD). A significant number of instruments have been developed and validated, yet the need remains to assess the quality of their studies and their properties. OBJECTIVES: To evaluate the measurement properties and link the content extracted from self-efficacy instrument items for individuals with CAD to the International Classification of Functioning, Disability, and Health (ICF). METHODOLOGY: The study was conducted following the Cochrane systematic review guidelines and COnsensus norms for Selection of health Measuring INstruments (COSMIN), registered under CRD42021262613. The search was carried out on MEDLINE (Ovid), Web of Science, EMBASE, and PsycINFO, including studies involving the development and validation of self-efficacy instruments for individuals with CAD, without language or date restrictions. Data extraction was performed in May 2022 and updated in January 2023 and all the steps of this review were carried out by two different collaborators and reviewed by a third when there were divergences. Modified Grading of Recommendations, Assessment, Development and Evaluation (GRADE) recommended by COSMIN was used to determine the quality of evidence as high, moderate, low, or very low. Instrument categorization was carried out per COSMIN recommendations, according to the construct of interest and study population into three categories (A, B, or C). RESULTS: A total of 21 studies from 12 instruments were identified. The best-rated instruments received a recommendation of B, which means, additional validation studies are needed. Barnason Efficacy Expectation Scale (BEES) showed high-quality evidence for structural, construct, criterion, and internal consistency validity; Cardiac Self-Efficacy Scale (CSES) demonstrated high quality for content, structural, cross-cultural validity, and internal consistency; Self-efficacy for Appropriate Medication Use (SEAMS) achieved a high level for structural, criterion, and internal consistency validity; Cardiovascular Management Self-Efficacy Scale exhibited high-level validity for structural, criterion, construct, and internal consistency. The CSES showed content linkage with all domains of the ICF, as well as the highest number of linkages with the categories. CONCLUSIONS: Instruments with a B-level recommendation hold potential for use. More studies assessing measurement properties are needed to reinforce or improve these recommendations. The CSES stands out as the most comprehensive instrument concerning the ICF.
Subject(s)
Coronary Artery Disease , Humans , Consensus , GRADE Approach , Heart , Self EfficacyABSTRACT
Chronic Non-Communicable Diseases (NCDs) are the main causes of death worldwide, responsible for millions of hospital admissions per year, especially cardiovascular diseases (CVD). Several strategies for controlling and coping with these diseases have been developed in several countries. The aim of the study was to evaluate the impact of the Strategic Action Plan to Combat NCDs (2011-2022) on hospital admissions, deaths and mortality rate in Brazil, classified by CVD. This is a descriptive study, with secondary data from the Hospital Information System of the Unified Health System (SIH/SUS). Hospital admissions, deaths and mortality rate due to CVD in the Brazilian population aged over 20 years were analyzed, according to region, sex and age group. Statistical analysis was performed using the GraphPad Prism program. Data normality was assessed using the Komogorov Smirnov test and the comparison between groups and year periods was performed using the two-way ANOVA test with Tukey's post hoc test. A value of p<0.05 was considered significant. In this study, in most analyses, a reduction in the hospitalization rates of the adult population was observed after the implementation of the plan, however, there was no improvement in relation to the number of deaths and mortality rate from CVD. This shows that there is still a long way to go to reduce the impact of these diseases in Brazil, and they reaffirm the need for and importance of maintaining the prevention of their risk factors, the social determinants of health and the reorganization of care in the face of to population aging. Such findings contribute with information that allow better control and monitoring of CVD and should be considered when implementing new strategies for prevention, care and control of risk factors.
Subject(s)
Cardiovascular Diseases , Noncommunicable Diseases , Adult , Aged , Brazil/epidemiology , Cardiovascular Diseases/prevention & control , Cause of Death , Hospitalization , Hospitals , Humans , Noncommunicable Diseases/prevention & controlABSTRACT
BACKGROUND: Diabetes mellitus (DM) is an important public health problem worldwide. In addition to the impairment in functionality, the large number of complications which lead to hospitalizations results in high treatment costs. The aim of this study was to analyze the incidence of hospitalizations, mortality rate and hospital costs, as well as to observe the temporal trend of hospitalizations and length of hospital stay due to DM between 2008 and 2019 in Brazil. METHODS: This is a longitudinal descriptive study in which all data regarding hospital admissions registered in the Brazilian system of Hospital Information of "Sistema Único de Saúde" (SIH/SUS; http://datasus.saude.gov.br ) due to DM (ICD-10) were included. Comparisons among the groups were performed by an unpaired Student's t-test, two-way ANOVA with a Tukey post hoc test (p < 0.05). RESULTS: An increased hospitalization of 1.83% due to DM was observed between 2008 and 2019 in Brazil. The Southeastern region had the highest incidence (34.6%) and mortality rate when compared to the other regions (p < 0.05). We also found that females were more likely to be hospitalized in comparison to males, without a statistically significant difference. Finally, a progressive increase of hospitalizations and mortality rate were observed according to age groups, as well as increased spending due to DM hospitalizations over the years. CONCLUSION: Hospitalizations due to DM in Brazil showed an expressive increase over the last 12 years, and there is a need for primary healthcare interventions to help reduce this situation.
Subject(s)
Diabetes Mellitus , Hospitalization , Brazil/epidemiology , Diabetes Mellitus/epidemiology , Female , Health Care Costs , Humans , Longitudinal Studies , MaleABSTRACT
BACKGROUND: Cardiovascular diseases (CVD) are the main cause of death and comorbidities worldwide. It is estimated that three quarters of all deaths related to CVD occur in low and middle income countries such as Brazil. Furthermore, it is estimated that emerging countries will present the highest worldwide prevalence of such diseases by 2050. In view of the above, this study aims to characterize Brazilian hospital admission distribution classified by the ICD-10 in adults between 2008 and 2017 in Brazil. METHODS: This is a longitudinal descriptive study in which all data regarding hospital admissions registered in the Brazilian Hospital Information System of "Sistema Único de Saúde" (SIH/SUS) due to cardiovascular diseases (ICD-10) were included. All admissions from private or public services linked to the SUS from 2008 and 2017 were evaluated. The following variables were collected: number of hospital admissions, place of hospitalization classified by the ICD-10 and mortality rate at the federal level and according to regions. Absolute values and frequency of hospital admissions were grouped according to sex, age and living region as well as the number of deaths. The extracted data was stored in a Microsoft Excel 2013 program spreadsheet. Statistical analysis was performed by GraphPad Prism version 5.0 software. RESULTS: There was a total of 11,345,821 hospital admissions due to CVD registered between 2008 and 2017. Individuals from 50 to 79 years old were the most affected. Heart failure (21.3%), other ischemic heart diseases (13.3%) and stroke (11.4%) were responsible for almost half of the hospital admissions associated to CVD. The number of registered deaths caused by any CVD was 867,838 and the national mortality rate was 7.82. CONCLUSION: CVD were responsible for around 10% of all hospital admissions in Brazil between 2008 and 2017. Moreover, it was possible to observe a decrease in hospital admissions as well as mortality rate over time after implementing governmental strategies to prevent cardiovascular diseases.
Subject(s)
Cardiovascular Diseases/epidemiology , Patient Admission/trends , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Cardiovascular Diseases/classification , Cardiovascular Diseases/mortality , Cardiovascular Diseases/therapy , Female , Hospital Mortality/trends , Humans , Incidence , International Classification of Diseases , Longitudinal Studies , Male , Middle Aged , Mortality , Time Factors , Young AdultABSTRACT
BACKGROUND: Chronic venous insufficiency (CVI) causes pathophysiological changes in the lower-limb muscles, particularly the calf muscles, and limits ankle range of motion (ROM). These changes reduce functional activities and decrease quality of life (QOL). Although several studies have shown the benefits of exercise (strengthening the calf muscles to improve calf-muscle pumping and QOL) in patients with CVI, few studies are randomized controlled trials. This has led to a weak indication of exercise for the treatment of patients with CVI. The aim of this study is to analyze the effects of a supervised exercise program to improve calf-muscle endurance as well as QOL in patients with CVI. METHODS/DESIGN: This is an evaluator-blind, randomized clinical trial with an 8-week duration and a follow-up evaluation at week 16. A pilot study with subjects with a CVI diagnosis will be performed to calculate sample size. The participants will be randomly allocated (1:1) into a treatment or a control group (usual care/no intervention). The treatment intervention consists of a bi-weekly supervised exercise program of the lower limbs that will include aerobic training, strengthening and cardiovascular exercises. The participants from both groups will participate in a health education lecture. Primary outcomes are changes in calf-muscle endurance and QOL score. Secondary outcomes are changes in exercise capacity, ankle ROM, electrical muscle activity and cardiac output. The first statistical comparison will be performed after 8 weeks' intervention. DISCUSSION: Patients with CVI may have an impaired calf-muscle pump and decreased exercise capacity. A randomized controlled trial evaluating a supervised exercise program should provide much needed information on the management of CVI to promote health and independence. TRIAL REGISTRATION: This study was registered on the Brazilian Clinical Trials Database (REBEC) (RBR-57xtk7). The results will be disseminated at scientific events, presentations, and publications in peer-reviewed journals.
Subject(s)
Exercise Therapy , Leg/blood supply , Muscle, Skeletal/blood supply , Venous Insufficiency/therapy , Ankle Joint/physiopathology , Brazil , Chronic Disease , Humans , Muscle, Skeletal/physiopathology , Pilot Projects , Plethysmography , Quality of Life , Randomized Controlled Trials as Topic , Range of Motion, Articular , Treatment Outcome , Venous Insufficiency/physiopathologyABSTRACT
BACKGROUND: The expansion of the rib cage and abdomen occurs in a synchronic way during a coordinated contraction of the diaphragm and the abdominal and intercostal muscles under normal conditions and healthy. The presence of restrictive respiratory disease may lead to uncoordinated action of the respiratory muscles which affects breathing pattern and chest wall volumes. The aim of this study was to evaluate chest wall volumes, chest wall asynchrony and inspiratory paradoxical movement of breathing, as well as the influence of the time of disease diagnosis in subjects with Parkinson's disease and post-Stroke in comparison to healthy individuals. METHODS: Total and compartmental chest wall volumes, chest wall asynchrony and paradoxical movement were measured at rest in a seated position by Optoelectronic Plethysmography in 76 individuals (29 healthy individuals, 20 post-Stroke and 27 Parkinson's disease subjects). Post-stroke and Parkinson's disease subjects were also grouped according to the length of diagnosis. RESULTS: In both groups with restrictive respiratory disease we observed that pulmonary rib cage compartment (VRCp) volume is reduced when compared to healthy subjects (p <0.05). This same pattern was observed when analyzing post-stroke subjects with more than three years of diagnosis and Parkinson's subjects with less than three years of diagnosis (p<0.05). Furthermore, post-stroke subjects with inspiratory paradoxical movement showed decreased total and compartmental chest wall volumes (p<0.05), while individuals with Parkinson's disease with inspiratory paradoxical movement only presented a decrease in pulmonary rib cage compartment volume (p<0.05). CONCLUSION: Our study presents new findings for better understanding of chest wall volumes and chest wall asynchrony in post-stroke and Parkinson's disease individuals. Half of the subjects with post-Stroke and Parkinson's disease presented inspiratory paradox movement, but changes in breathing pattern was especially observed in post-stroke subjects with more than three years of diagnosis.
Subject(s)
Parkinson Disease/pathology , Parkinson Disease/physiopathology , Respiratory Mechanics/physiology , Stroke/pathology , Stroke/physiopathology , Thoracic Wall/pathology , Thoracic Wall/physiopathology , Aged , Case-Control Studies , Female , Humans , Lung/physiopathology , Male , Middle Aged , Organ Size , Respiratory Muscles/physiopathologyABSTRACT
BACKGROUND: Chronic obstructive pulmonary disease (COPD) leads to peripheral and respiratory muscle dysfunctions. Nowadays, inspiratory muscle training can be geared toward strength or endurance gains. This study aims to investigate the effects of an inspiratory muscle training (IMT) protocol using different therapeutic modalities to be implemented in pulmonary rehabilitation programs. The effects of IMT on exercise capacity were considered as the primary endpoint, and the effects of IMT on inspiratory muscle function, health-related quality of life, and daily physical activity level were considered as the secondary outcomes. METHODS: This study is a blinded-investigator randomized controlled clinical trial. Sixty subjects will be randomly allocated into three groups: (1) pulmonary rehabilitation (PR) associated with inspiratory muscle training without any load (PRWIMT), (2) PR associated with inspiratory muscle training with a linear load (PRIMTLL), and (3) PR associated with inspiratory muscle training with isocapnic voluntary hyperpnea (PRIMTIVH). The protocol will be performed 5 days a week (3 days with supervision) for 10 weeks. The study will assess anthropometric data, lung function, respiratory muscle strength, and functional capacity by the Incremental Shuttle Walking Test and the Six-Minute Walk Test, lung volumes during the submaximal endurance test, peripheral muscle strength of the upper and lower limbs, dyspnea, and quality of life related to health, before and after the training protocol. Normality will be tested using the Kolmogorov-Smirnov test, and variables will be compared by two-way analysis of variance. The significance level was set at p < 0.05. Ethics approval was obtained from the Institutional Ethics Committee in Research (1.663.411). The study results will be disseminated through presentation at specific scientific conferences and publication in peer-reviewed journals. DISCUSSION: The different IMT protocols used in our study will be able to guide respiratory therapists to understand and to include in conventional PR programs the most effective respiratory muscle training type in subjects with COPD. TRIAL REGISTRATION: Brazilian Clinical Trials Registry, RBR-94v6kd . Registered on 11 March 2017.
Subject(s)
Breathing Exercises/methods , Inhalation , Pulmonary Disease, Chronic Obstructive/rehabilitation , Respiratory Muscles/physiopathology , Activities of Daily Living , Adult , Aged , Aged, 80 and over , Brazil , Exercise Tolerance , Female , Humans , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/physiopathology , Quality of Life , Randomized Controlled Trials as Topic , Recovery of Function , Time Factors , Treatment OutcomeABSTRACT
ABSTRACT Positive Expiratory Pressure (PEP) improves lung function, however, PEP-induced changes are not fully established. The aim of this study was to assess the acute effects of different PEP levels on chest wall volumes and the breathing pattern in children with Cystic Fibrosis (CF). Anthropometric data, lung function values, and respiratory muscle strength were collected. Chest wall volumes were assessed by Optoelectronic plethysmography at rest and during the use of different PEP levels (10 and 20 cm H2O), randomly chosen. Eight subjects with CF (5M, 11.5±3.2 years, 32±9.5 kilograms) and seven control subjects (4M, 10.7±1.5 years, 38.2±7.8 kilograms) were recruited. The CF group showed significantly lower FEF values 25-75% (CF: 1.8±0.8 vs. CG: 2.3±0.6) and FEV1/FVC ratio (CF: 0.8±0.1 vs. CG: 1±0.1) compared with the control group (p<0.05). Different PEP levels increased the usual volume in chest wall and its compartments in both groups; however, this volume was significantly higher in the control group compared with the CF group during PEP20 (CW: 0.77±0.25 L vs. 0.44±0.16 L; RCp: 0.3±0.13 L vs. 0.18±0.1 L; RCa: 0.21±0.1 L vs. 0.12±0.1 L; AB: 0.25±0.1 L vs. 0.15±0.1 L; p<0.05 for all variables). Minute ventilation was significantly higher during PEP compared with breathing at rest in both groups (p<0.005). End-expiratory volume was also higher during PEP compared with breathing at rest for chest wall and pulmonary rib cage in both groups (p<0.05). Different PEP levels may increase chest wall volumes in CF patients.
RESUMO Pressão Expiratória Positiva (PEwP) melhora a função pulmonar, entretanto, as mudanças induzidas pela PEP não estão totalmente estabelecidas. O objetivo do estudo foi avaliar os efeitos agudos de diferentes intensidades de PEP nos volumes da parede torácica (PT) e padrão respiratório em crianças com Fibrose Cística (FC). Dados antropométricos, função pulmonar e força da musculatura respiratória. Os volumes da PT foram avaliados através da Pletismografia Optoeletrônica (POE) em repouso e durante o uso de diferentes intensidades de PEP (10 e 20 cm H2O). Foram recrutados 8 sujeitos com FC (5H; 11,5 ± 3,2 anos; 32 ± 9,5 kg) e 7 sujeitos (4H; 10,7 ± 1,5 anos; 38,2 ± 7,8 kg). Grupo FC mostrou valores significativamente menores para FEF 25-75% (FC: 1,8 ± 0,8 vs. GC: 2,3 ± 0,6) e relação VEF1/CVF (FC: 0,8 ± 0,1 vs. GC: 1 ± 0,1) comparado ao grupo controle (p>0,05). Diferentes intensidades de PEP levaram a um aumento do volume corrente da PT e seus compartimentos em ambos os grupos, entretanto, este volume aumentou de forma significativa no grupo controle quando comparado ao grupo FC durante PEP20 (CW: 0,77 ± 0,25 L vs. 0,44 ± 0,16 L; RCp: 0,3 ± 0,13 L vs. 0,18 ± 0,1 L; RCa: 0,21 ± 0,1 L vs. 0,12 ± 0,1 L; AB: 0,25 ± 0,1 L vs. 0,15 ± 0,1 L; p>0,05 para todas as variáveis). A ventilação minuto aumentou de forma significativa durante a PEP em comparação a respiração em repouso para ambos os grupos (p>0,005). Volume expiratório final também foi maior durante a PEP em comparação a respiração em repouso para PT e caixa torácica pulmonar em ambos os grupos (p>0,05). Diferentes intensidades de PEP podem induzir aumentos nos volumes da parede torácica em pacientes com FC.
RESUMEN La Presión Espiratoria Positiva (PEP) mejora la función pulmonar, mientras tanto, los cambios inducidos por la PEP no están totalmente establecidos. El objetivo del estudio fue evaluar los efectos agudos de distintas intensidades de PEP en los volúmenes de la pared torácica (PT) y patrón respiratorio en niños con Fibrosis Cística (FC). Datos antropométricos, función pulmonar y fuerza de la musculatura respiratoria. Los volúmenes de la PT fueron evaluados a través de la Pletismografía Optoelectrónica (POE) en reposo y durante el uso de distintas intensidades de PEP (10 y 20 cm H2O). Fueron reclutados 8 sujetos con FC (5H; 11,5 ± 3,2 años; 32 ± 9,5 kg) y 7 sujetos (4H; 10,7 ± 1,5 años; 38,2 ± 7,8 kg). Grupo FC mostró valores significativamente menores para FEF 25-75% (FC: 1,8 ± 0,8 vs. GC: 2,3 ± 0,6) y relación VEF1/CVF (FC: 0,8 ± 0,1 vs. GC: 1 ± 0,1) comparado al grupo control (p>0,05). Distintas intensidades de PEP conllevaron a un incremento del volumen corriente de la PT y sus compartimentos en ambos los grupos, mientras tanto, este volumen incrementó de manera significativa en el grupo control cuando comparado al grupo FC durante PEP20 (CW: 0,77 ± 0,25 L vs. 0,44 ± 0,16 L; RCp: 0,3 ± 0,13 L vs. 0,18 ± 0,1 L; RCa: 0,21 ± 0,1 L vs. 0,12 ± 0,1 L; AB: 0,25 ± 0,1 L vs. 0,15 ± 0,1 L; p>0,05 para todas las variables). La ventilación minuto incrementó de manera significativa durante la PEP en comparación a la respiración en reposo para ambos grupos (p>0,005). El volumen espiratorio final también fue más grande durante la PEP en comparación a la respiración en reposo para PT y la caja torácica pulmonar en ambos los grupos (p>0,05). Las distintas intensidades de PEP pueden inducir incrementos en los volúmenes de la pared torácica en pacientes con FC.
ABSTRACT
OBJECTIVE: To evaluate sensitivity/specificity of the maximum relaxation rate (MRR) of inspiratory muscles, amplitude of electromyographic activity of the sternocleidomastoid (SCM), scalene (SCA), parasternal (2ndIS) and rectus abdominis (RA) muscles; lung function and respiratory muscle strength in subjects with Myotonic dystrophy type 1 (DM1) compared with healthy subjects. DESIGN AND METHODS: Quasi-experimental observational study with control group. MRR of inspiratory muscles, lung function and amplitude of the electromyographic activity of SCM, SCA, 2ndIS and RA muscles during maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax) and sniff nasal inspiratory pressure (SNIP) tests were assessed in eighteen DM1 subjects and eleven healthy. RESULTS: MRR was lower in DM1 group compared to healthy (P = 0.001) and was considered sensitive and specific to identify disease in DM1 and discard it in controls, as well as SNIP% (P = 0.0026), PImax% (P = 0.0077) and PEmax% (P = 0.0002). Contraction time of SCM and SCA was higher in DM1 compared to controls, respectively, during PImax (P = 0.023 and P = 0.017) and SNIP (P = 0.015 and P = .0004). The DM1 group showed lower PImax (P = .0006), PEmax (P = 0.0002), SNIP (P = 0.0014), and higher electromyographic activity of the SCM (P = 0.002) and SCA (P = 0.004) at rest; of 2ndIS (P = 0.003) during PEmax and of SCM (P = 0.02) and SCA (P = 0.03) during SNIP test. CONCLUSIONS: MD1 subjects presented restrictive pattern, reduced respiratory muscle strength, muscular electrical activity and MRR when compared to higher compared to controls. In addition, the lower MRR found in MD1 subjects showed to be reliable to sensitivity and specificity in identifying the delayed relaxation of respiratory muscles.
Subject(s)
Muscle Strength/physiology , Myotonic Dystrophy/physiopathology , Respiratory Muscles/physiopathology , Adult , Anthropometry , Electromyography , Exhalation/physiology , Female , Humans , Inhalation/physiology , Male , Muscle Relaxation/physiology , Pressure , ROC Curve , Respiratory Function Tests , Sample Size , Time FactorsABSTRACT
OBJECTIVE: To determine whether a short-term protocol using subcutaneous sensitization with ovalbumin, without the use of adjuvants, would induce an eosinophilic response in the lungs of mice similar to that observed in previous, well-established protocols. METHODS: Adult female BALB/c mice were randomized and divided into groups according to the number of sensitizations with ovalbumin and the number/dosage of intranasal ovalbumin challenges. The short-term protocol (10 days) consisted of one sensitization with ovalbumin and three ovalbumin challenges (100 µg). Total and differential cell counts in BAL fluid, levels of eosinophil peroxidase in lung tissue, and histopathological examination of the lungs were performed 24 h after the last ovalbumin challenge. RESULTS: No significant differences were found among the groups regarding the variables studied. The short-term protocol, as well as the other protocols studied, induced an eosinophilic response similar to that obtained in the positive control. CONCLUSIONS: Subcutaneous sensitization with ovalbumin and without the use of adjuvants resulted in a significant allergic response in the lungs of mice, even in the short-term protocol group. Our findings suggest that this short-term protocol can be used as a first-line pre-clinical test for the study of new medications, reducing the costs and observation periods.
Subject(s)
Asthma/pathology , Bronchial Hyperreactivity/pathology , Eosinophil Peroxidase/metabolism , Lung/pathology , Ovalbumin , Pulmonary Eosinophilia/immunology , Acute Disease , Animals , Asthma/enzymology , Bronchial Hyperreactivity/enzymology , Bronchial Provocation Tests , Bronchoalveolar Lavage Fluid/cytology , Disease Models, Animal , Female , Lung/enzymology , Mice , Mice, Inbred BALB C , Pulmonary Eosinophilia/pathology , Random AllocationABSTRACT
OBJETIVO: Determinar se um protocolo curto de sensibilização com ovalbumina subcutânea, sem adjuvante, induziria uma resposta pulmonar eosinofílica em pulmões de camundongos similar àquela encontrada em protocolos previamente estabelecidos. MÉTODOS: Fêmeas adultas de camundongos BALB/c foram randomizadas e divididas em grupos de acordo com o número de sensibilizações com ovalbumina e o número/dosagem de provocação intranasal. O protocolo curto (10 dias) consistiu de uma sensibilização e três provocações com ovalbumina (100 µg). A contagem total e diferencial de células no lavado broncoalveolar, o nível de peroxidase eosinofílica no tecido pulmonar e o exame histopatológico dos pulmões foram realizados 24 h após a última provocação. RESULTADOS: Não houve diferenças significativas entre os grupos em relação às variáveis estudadas. O protocolo curto, assim como os outros protocolos estudados, induziu uma resposta eosinofílica pulmonar semelhante àquela do grupo controle positivo. CONCLUSÕES: A sensibilização por ovalbumina subcutânea sem o uso de adjuvante resultou em uma significativa resposta pulmonar alérgica em ratos, mesmo no grupo de protocolo curto. Nossos achados sugerem que esse protocolo curto pode ser utilizado como teste pré-clínico de primeira linha para a pesquisa de novos fármacos, reduzindo custos e o tempo de observação.
OBJECTIVE: To determine whether a short-term protocol using subcutaneous sensitization with ovalbumin, without the use of adjuvants, would induce an eosinophilic response in the lungs of mice similar to that observed in previous, well-established protocols. METHODS: Adult female BALB/c mice were randomized and divided into groups according to the number of sensitizations with ovalbumin and the number/dosage of intranasal ovalbumin challenges. The short-term protocol (10 days) consisted of one sensitization with ovalbumin and three ovalbumin challenges (100 µg). Total and differential cell counts in BAL fluid, levels of eosinophil peroxidase in lung tissue, and histopathological examination of the lungs were performed 24 h after the last ovalbumin challenge. RESULTS: No significant differences were found among the groups regarding the variables studied. The short-term protocol, as well as the other protocols studied, induced an eosinophilic response similar to that obtained in the positive control. CONCLUSIONS: Subcutaneous sensitization with ovalbumin and without the use of adjuvants resulted in a significant allergic response in the lungs of mice, even in the short-term protocol group. Our findings suggest that this short-term protocol can be used as a first-line pre-clinical test for the study of new medications, reducing the costs and observation periods.
Subject(s)
Animals , Female , Mice , Asthma/pathology , Bronchial Hyperreactivity/pathology , Eosinophil Peroxidase/metabolism , Lung/pathology , Ovalbumin , Pulmonary Eosinophilia/immunology , Acute Disease , Asthma/enzymology , Bronchial Provocation Tests , Bronchial Hyperreactivity/enzymology , Bronchoalveolar Lavage Fluid/cytology , Disease Models, Animal , Lung/enzymology , Mice, Inbred BALB C , Pulmonary Eosinophilia/pathology , Random AllocationABSTRACT
Objetivos: Testar alternativas de protocolos com modelos animais de asma aguda e crônica que apresentem características mais próximas da doença em humanos, utilizando ovalbumina livre de adjuvante.Métodos: Foram utilizadas fêmeas adultas de camundongos BALB/c, divididas em grupos de acordo com as sensibilizações com ovalbumina. O modelo agudo utilizou duas doses de ovalbumina subcutânea, sem adjuvante, com intervalo de sete dias, com posterior desafio intranasal durante três dias, comparado ao protocolo padrão que utiliza três doses de ovalbumina intraperitoneal, no período de sensibilização. O modelo crônico também utilizou ovalbumina subcutânea livre de adjuvante para sensibilização, com intervalo de 14 dias e posterior desafio intranasal, três vezes por semana, durante oito semanas. Contagem total e diferencial de células no lavado broncoalveolar e análise histológica dos pulmões foram realizadas 24 horas após o último desafio com ovalbumina.Resultados: Nos dois modelos estudados, agudo e crônico, observou-se uma resposta eosinofílica pulmonar semelhante entre os grupos. A contagem de células e a análise histológica do tecido pulmonar não apresentaram diferença significativa entre os grupos estudados.Conclusões: O uso de sensibilização subcutânea em modelo murino com ovalbumina, sem adjuvante (alum), resulta em significativa resposta inflamatória pulmonar alérgica, com predomínio de eosinófilos, podendo ser uma opção futura para experimentos mais próximos ao modelo humano, tanto na fase aguda, como na fase crônica da doença.
Aims: To test alternative protocols using animal models of acute and chronic asthma, with features closer to human disease, using ovalbumin without adjuvant. Methods: Adult female BALB/c mice were used and divided into groups according to sensitization with ovalbumin. The acute model used two doses of ovalbumin subcutaneously without adjuvant, on days 0 and 7, and after intranasal challenge for consecutives three days, compared with a standard protocol using three doses of ovalbumin for sensitization. The chronic model also used ovalbumin subcutaneously for sensitization, adjuvant-free, on days 0 and 14, and after intranasal challenge, for eight consecutive weeks. Total and differential cell counts from bronchoalveolar lavage and histopathology of the lungs were performed 24 hours after the last ovalbumin challenge. Results: In both models of protocols studied, acute and chronic, we have observed similar allergic pulmonary response between the groups. Cell counts and histological analysis of lung tissue showed no significant difference between groups. Conclusions: Use of sensitization in murine model with ovalbumin subcutaneously, with no adjuvant (alum), resulted in an expected allergic pulmonary response, with predominant eosinophils. These protocols may be a future option to animal models of asthma closer to the human disease, both in the acute and chronic patterns.
Subject(s)
Mice , Models, Animal , Asthma , Hypersensitivity , OvalbuminABSTRACT
Objetivos: discutir as vantagens e limitações de pesquisas com modelos murinos em asma e suas aplicações mais imediatas.Fonte de Dados: foi realizada revisão da literatura no PubMed. Os descritores utilizados foram: mice, asthma, animal model e murine model. Síntese dos Dados: modelos experimentais murinos têm sido muito utilizados para elucidar a fisiopatogenia da asma brônquica e para avaliar novos alvos terapêuticos. Diversas críticas surgiram nos últimos anos em relação aos modelos utilizados. Os modelos animais diferem bastante da asma em humanos, particularmente em relação à utilização de adjuvante, via de administração e dose dos alergenos, além do tipo de resposta inflamatória pulmonar.Conclusões: novos modelos experimentais devem reproduzir da forma mais próxima possível as características da asma em humanos. Embora o modelo murino apresente inúmeras vantagens em relação a outros modelos animais, as limitações inerentes a esse tipo de estudo devem ser levadas em consideração no momento da extrapolação dos resultados para a doença em humanos.
Aims: To discuss the advantages and limitations of studies using murine models in asthma and the most immediate applications. Source of Data: A review of the literature using PubMed database was performed. The keywords used were: mice, asthma, animal model and murine model. Summary of Findings: Experimental models have been used to elucidate the pathophysiology of asthma and to evaluate new therapeutic targets. Several limitations related to the models currently used have emerged in recent years. Animal models are very different from the human asthma, particularly regarding to the use of adjuvant, administration route, dose of allergen and the type of pulmonary inflammatory response. Conclusions: New experimental models must reproduce the characteristics of human asthma as close as possible. Although murine models show several advantages in relation to other animals, the inherent limitations of this type of study must be considered before the extrapolation of results to human pathology.