Comparative performance of screening instruments for obstructive sleep apnea in morbidly obese patients referred to a sleep laboratory: a prospective cross-sectional study.

PURPOSE: Obstructive sleep apnea (OSA) is very common occurrence among morbidly obese patients. Our main objectives were to validate the No-Apnea, a 2-item screening tool, in morbidly obese patients and compare its performance with three other instruments: STOP-Bang questionnaire, NoSAS score, and Epworth Sleepiness Scale (ESS). METHODS: A cross-sectional analysis of morbidly obese patients (body mass index [BMI] ≥ 35.0 kg/m2) grouped into two independent samples: bariatric surgery patients (BS) and non-bariatric surgery patients (NBS). All patients underwent overnight polysomnography. Discriminatory ability was assessed by area under the curve (AUC). OSA severity was defined by apnea/hypopnea index cut-off points: ≥ 5.0/h (OSA≥5), ≥ 15.0/h (OSA≥15), and ≥ 30.0/h (OSA≥30). RESULTS: A total of 1017 subjects (40.4% in BS cohort and 59.6% in NBS cohort) were evaluated. In the BS cohort, No-Apnea had similar discrimination to STOP-Bang and NoSAS for predicting OSA≥5 (p = 0.979 and p = 0.358, respectively), OSA≥15 (p = 0.158 and p = 0.399, respectively), and OSA≥30 (p = 0.388 and p = 0.903, respectively). In the NBS cohort, No-Apnea had similar discrimination to STOP-Bang and NoSAS for predicting OSA≥5 (p = 0.528 and p = 0.428, respectively), OSA≥15 (p = 0.825 and p = 0.108, respectively), and OSA≥30 (p = 0.458 and p = 0.186, respectively). Moreover, No-Apnea performed significantly better than ESS in both BS and NBS cohorts (p < 0.001). CONCLUSIONS: No-Apnea is a useful and practical tool for screening of OSA in morbidly obese patients, with non-inferior performance to STOP-Bang questionnaire and NoSAS score.

Fractional Exhaled Nitric Oxide Measurements and Screening of Obstructive Sleep Apnea in a Sleep-Laboratory Setting: A Cross-Sectional Study.

PURPOSE: Obstructive sleep apnea (OSA) is a common condition characterized by repetitive collapse of the upper airways and intermittent oxygen desaturation, which may lead to airway inflammation. Here, we explored whether fractional exhaled nitric oxide (FeNO) levels provide a non-invasive screening tool of OSA. METHODS: Over a 3-month period, FeNO levels were measured in consecutive non-smoking patients referred for a sleep laboratory. All patients underwent full polysomnography. OSA severity was classified based on the apnea/hypopnea index: ≥ 5.0/h as any OSA, ≥ 15.0/h as moderate/severe OSA, and ≥ 30.0/h as severe OSA. FeNO was measured by a portable device (NIOX-MINO®; Aerocrine AB, Solna, Sweden) and expressed as parts per billion (ppb). Discrimination by area under the curve (AUC) and binary logistic regression were performed. RESULTS: A total of 229 subjects were evaluated. Mean FeNO values were similar among subjects without OSA or with OSA: 16.9 ± 10.6 ppb versus 20.2 ± 14.5 ppb, p = 0.221; respectively. FeNO was not an inclusionary parameter to predict any OSA, moderate/severe OSA, and severe OSA: odds ratio (OR) 1.023 (95% confidence interval [CI]: 0.986-1.062); OR 1.012 (95% CI: 0.991-1.034); and OR 0.999 (95% CI: 0.980-1.018), respectively. The AUC values for FeNO in the diagnosis of any OSA, moderate/severe OSA, and severe OSA showed no discriminatory properties: AUC: 0.567 (95% CI: 0.464-0.670), AUC: 0.541 (95% CI: 0.465-0.618), and AUC: 0.535 (95% CI: 0.459-0.610); respectively. CONCLUSIONS: In a sleep-lab setting, our findings suggest that FeNO measurements are inconsequential in the screening of OSA in adults.

Effect of continuous positive airway pressure on fluid absorption among patients with pleural effusion due to tuberculosis / Efeito da pressão positiva nas vias aéreas sobre a absorção do derrame pleural em pacientes devido à tuberculose

BACKGROUND: Tuberculosis (TB) remains as an important public health problem worldwide. The most common type is pulmonary TB, and the most prevalent form of extra-pulmonary disease among HIV-negative patients is pleural disease. OBJECTIVE: The objective of the present study was to determine the effect of continuous positive airway pressure (CPAP) on fluid absorption among patients with pleural effusion due to TB. METHODS: Twenty patients were randomized into two groups. The interventional group (n=10) received CPAP three times a week during the initial four weeks of anti-TB treatment, and the control group (n=10) received anti-TB drugs only. The primary endpoint was the volume of pleural fluid after four weeks of treatment. Both groups were submitted to thoracic computed tomography using three-dimensional image reconstruction. The Mann-Whitney test for independent samples and the Wilcoxon paired samples test were used for statistical analysis. The normal distribution samples were analyzed using the unpaired t test. RESULTS: The reduction of pleural effusion volume was significantly greater in the intervention group (83.5 percent±SD 3.6) than in the control group (36.9 percent±SD 2.9; p<0.001), and the final dyspnea index was lower in the Intervention group than in the control group (p=0.002). CONCLUSION: Our findings indicate that CPAP during the first month of TB treatment accelerates the absorption of pleural effusion, however, additional studies are needed to confirm these findings and evaluate the impact of CPAP on pleural sequelae after the end of anti-TB treatment.

CONTEXTUALIZAÇÃO: A tuberculose (TB) permanece como um importante problema de saúde pública no mundo. A forma mais comum de apresentação é a pulmonar e, em pacientes soronegativos, a forma de doença extrapulmonar mais prevalente é a pleural. OBJETIVO: O objetivo deste estudo foi determinar o efeito da pressão positiva contínua em vias aéreas (CPAP) na absorção do derrame pleural em pacientes com tuberculose. MÉTODOS: Vinte pacientes foram randomizados em dois grupos. O grupo intervenção (n=10) recebeu CPAP três vezes por semana durante as quatro primeiras semanas do tratamento anti-TB, e o grupo controle (n=10) recebeu somente droga anti-TB. O ponto final de avaliação foi o volume de líquido pleural após quatro semanas de tratamento. Ambos os grupos foram submetidos à tomografia computadorizada, usando a reconstrução tridimensional (3D) da imagem. A análise estatística foi realizada por meio do teste de Mann-Whitney para amostras independentes e Wilcoxon para amostras pareadas, e as que apresentaram distribuição normal foram analisadas por meio do teste t de Student não pareado. RESULTADOS: A redução do volume de derrame pleural foi significativamente maior no grupo intervenção (83,5 por cento±DP 3,6) que no grupo controle (36,9 por cento±DP 2,9) (p<0,001), e o índice de dispnéia final foi menor no grupo CPAP que no grupo controle (p=0,002). CONCLUSÃO: Tais achados indicam que a CPAP, durante o primeiro mês de tratamento anti-TB, acelera a absorção do derrame pleural, no entanto estudos adicionais são necessários para confirmar estes achados e avaliar o impacto da CPAP na sequela pleural após o término do tratamento anti-TB.

Sequence analysis of NAT2 gene in Brazilians: identification of undescribed single nucleotide polymorphisms and molecular modeling of the N-acetyltransferase 2 protein structure.

N-Acetyltransferase 2 (NAT2) metabolizes a variety of xenobiotics that includes many drugs, chemicals and carcinogens. This enzyme is genetically variable in human populations and polymorphisms in the NAT2 gene have been associated with drug toxicity and efficacy as well as cancer susceptibility. Here, we have focused on the identification of NAT2 variants in Brazilian individuals from two different regions, Rio de Janeiro and Goiás, by direct sequencing, and on the characterization of new haplotypes after cloning and re-sequencing. Upon analysis of DNA samples from 404 individuals, six new SNPs (c.29T>C, c.152G>T, c.203G>A, c.228C>T, c.458C>T and c.600A>G) and seven new NAT2 alleles were identified with different frequencies in Rio de Janeiro and Goiás. All new SNPs were found as singletons (observed only once in 808 genes) and were confirmed by three independent technical replicates. Molecular modeling and structural analysis suggested that p.Gly51Val variant may have an important effect on substrate recognition by NAT2. We also observed that amino acid change p.Cys68Tyr would affect acetylating activity due to the resulting geometric restrictions and incompatibility of the functional group in the Tyr side chain with the admitted chemical mechanism for catalysis by NATs. Moreover, other variants, such like p.Thr153Ile, p.Thr193Met, p.Pro228Leu and p.Val280Met, may lead to the presence of hydrophobic residues on NAT2 surface involved in protein aggregation and/or targeted degradation. Finally, the new alleles NAT2*6H and NAT2*5N, which showed the highest frequency in the Brazilian populations considered in this study, may code for a slow activity. Functional studies are needed to clarify the mechanisms by which new SNPs interfere with acetylation.

Estudo comparativo entre esfregaços de citologia nasal obtidos por cotonete e por escova em pacientes com rinite / A comparative study between nasal smears obtained by swabs and brushing in patients with rhinitis

Introdução: Embora recomendado, o estudo da citologia nasal não é realizado rotineiramente devido à falta de padronização, realização de contagens somente qualitativas, e a escassez de material obtido. Objetivos: Nosso estudo avaliou a possibilidade de realização de uma leitura quantitativa de esfregaços nasais por cotonete e por escova em pacientes com rinite, e comparou os achados obtidos através das duas técnicas. Casuística e Métodos: Foram selecionados sessenta pacientes apresentando história clínica de rinite. Todos foram submetidos, em uma mesma avaliação, sequencialmente, a um esfregaço por cotonete na narina esquerda e a um por escova na direita. O esfregaço foi realizado em lâmina de vidro, com análise qualitativa e quantitativa de eosinófilos, neutrófilos e células epiteliais. Os achados foram comparados através do coeficiente de correlação intraclasse e do coeficiente Kappa, quando apropriado. Resultados: Observamos que a análise quantitativa dos esfregaços em lâmina foi possível, porém dificultada por questões associadas à técnica do exame. Qualitativamente não houve diferença de achado dos três tipos celulares entre as duas técnicas, mas sim quantitativo e de forma significativa, sendo maior para o escovado. Conclusões: Concluímos que ambos os procedimentos são de fácil execução, baixo custo operacional, viáveis para realização ambulatorial, e de boa tolerância.

Distribuição de Polimorfismos de Base única (SNPs) no gene de TNF-alfa (-238/-308) entre pacientes com TB e outras pneumopatias: marcadores genéticos de susceptibilidade a ocorrência de TB? / Single Nucleotide Polymorphisms (SNPs) of the TNF-alpha (-238/-308) gene among TB and nom TB patients: susceptibility markers of TB occurrence?

INTRODUÇAO: Fatores genéticos podem desempenhar um importante papel na susceptibilidade à tuberculose (TB) ativa, e polimorfismos de base única (SNPs) em diferentes genes que codificam para citocinas têm sido descritos e associados com doenças. OBJETIVOS: Investigar o quanto polimorfismo na região promotora do gene que codifica para TNF-alfa (-238 e -308) estão associados a ocorrência de TB ativa. MÉTODOS: SNPs dentro do gene de TNF-alfa foram analisados por PCR- RFLP em dois grupos de indivíduos: pacientes com TB (n = 234) e pacientes com pneumopatias não TB (n = 113). RESULTADOS: Neste estudo, o alelo -238A esteve associado significantemente com susceptibilidade à ocorrência de TB e gravidade das formas clínicas (p = 0,00002; OR = 0,15; IC = 0,06-0,36). Por outro lado, o alelo -308A esteve associado significantemente com a proteção a outras formas de doença pulmonar (p = 0,02; OR = 1,95; IC = 1,07-3,58). CONCLUSÕES: Estes resultados preliminares sugerem a importância de estudos genéticos na ocorrência da TB. São necessários outros estudos para melhorar a compreensão sobre a patogênese do M. tb.

Yield of sputum induction in the diagnosis of pleural tuberculosis.

We prospectively evaluated the diagnostic yield of acid-fast bacilli smear and culture for Mycobacterium tuberculosis using sputum induction (SI) in the workup of patients with suspected pleural tuberculosis (TB) who were unable to produce sputum spontaneously. Of the 113 patients studied, a final diagnosis of pleural TB was made in 84 patients (71 HIV seronegative) and a final diagnosis of another disease in 29 patients. Histopathologic examination of the pleural biopsy tissue had the highest diagnostic yield (78%; 66/84). The bacteriologic yield was 62% (52/84) for the pleural tissue, 12% (10/84) for pleural fluid, and 52% (44/84) for sputum cultures obtained by SI. The yield of SI culture for M. tuberculosis was 55% (35/64) in patients with a normal radiograph (except for the pleural effusion) and 45% (9/20) in those with evidence of parenchymal disease suggestive of pulmonary TB (p = 0.6). The yield of sputum cultures obtained by SI is high in patients suspected of having pleural TB even in those cases with no pulmonary parenchymal abnormalities on the chest radiograph.