Abstract Objective: The incidence of tuberculosis worldwide has emphasized the need for better assays designed to diagnose the disease, principally the extrapulmonary form. The objective of the present study was to validate the performance of an automated method for the determination of adenosine deaminase (ADA) activity in pleural fluid (PF) and cerebrospinal fluid (CSF), comparing it with a conventional method (the modified Giusti method). Methods: In total, 134 samples were selected from among those tested in our laboratory: 94 PF samples and 40 CSF samples. The ADA activity was determined using the two methods. Inter- and intra-assay precision was determined, linear regression analysis was performed, simple concordance tests were conducted, and the means of the differences were calculated. Results: The correlation coefficients for PF and CSF samples were, respectively, 0.96 and 0.95. Inter-assay precision was determined using 21 replicates at 3 different activity levels: low, medium and high. The percentage coefficient of variation (%CV) was, respectively, 5.9, 8.1 and 5.8 for PF samples, compared with 21.9, 18.6 and 13.8 for CSF samples. Intra-assay precision in %CV was 1.3 and 11.7, respectively, for PF and CSF samples. The concordance between the methods in PF and CRF samples was, respectively, 96.8% and 100%, considering the reference values for the diagnosis of TB to be 40 U/L (conventional) and 30 U/L (automated) in PF samples, versus 9 U/L (for both methods) in CSF samples. Conclusions: The results validate the use of the automated method of determining ADA activity in PF and CSF samples as an alternative to the conventional method.

Keywords: Adenosine deaminase; Tuberculosis/diagnosis; Pleural effusion; Cerebrospinal fluid.

Objective: To evaluate cough efficiency using two manually-assisted cough techniques. Methods: We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60% of predicted. Peak cough flow (PCF) was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE); during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique). The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05). Results: The mean age of the patients was 20 ± 4 years, and the mean FVC was 29 ± 12%. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 ± 67, 231 ± 81, 225 ± 80, and 292 ± 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001). Conclusions: Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001).

Keywords: Muscular dystrophy, Duchenne; Intermittent positive-pressure ventilation; Cough; Insufflation;Peak expiratory flow rate.

The physiopathology of obstructive sleep apnea syndrome is multifactorial. Gender and obesity status, as well as genetic, anatomic, and hormonal factors, together with ventilatory drive, interact in a diverse manner in the physiopathology and clinical expression of the disease. Obesity is the main risk factor, since increases in body mass index, visceral fat, and neck circumference are strong predictors of the disease. Progesterone increases the activity of the upper airway dilator muscles and therefore plays a protective role in premenopausal women. This explains the fact that the prevalence of the disease is higher in postmenopausal patients, in patients with polycystic ovary syndrome, as well as in males. Evidence supports the fact that, as individuals grow older, there is a decrease in muscle tonus, with a consequent reduction in the dimensions of the upper airway lumen. Craniofacial anomalies, such as in retrognathia or micrognathia, are accompanied by posterior positioning of the tongue and can result in narrowing of the upper airway lumen. Finally, decreased ventilatory drive has been detected in patients with obstructive sleep apnea syndrome and hypercapnia.

Keywords: Sleep apnea obstructive/physiopathology; Body mass index; Obesity

Recent years have seen a growing interest in the use of portable monitoring devices for the diagnosis of obstructive sleep apnea syndrome. These have the potential to be used in lieu of the more complicated and uncomfortable alternative, polysomnography, which has long been considered to be the gold standard for the diagnosis of this relatively prevalent condition. Following their approval in 2008 by the Center of Medicare and Medicaid Services, the federal agency which administers Medicare and Medicaid in the United States, there has been extensive discussion about the utility and validity of these devices for use in the diagnosis of obstructive sleep apnea syndrome. Although there are various models of portable monitoring devices, the literature contains little information regarding how each device should be used in specific age groups, patients presenting comorbidities, and asymptomatic patients. Additionally, studies about the cost-effectiveness of this diagnostic method are scarce and conflicting. Therefore, this objective of this study was to review what has been learned about portable monitoring devices over time, as well as to examine the recent progress, advantages, limitations, and applications of these devices in the diagnosis of obstructive sleep apnea syndrome in different groups of patients.

Keywords: Sleep apnea, obstructive/diagnosis; Polysomnography; Diagnostic equipment; Monitoring, ambulatory.

Objective: Obstructive sleep apnea syndrome is mainly characterized by intermittent hypoxia (IH) during sleep, being associated with several complications. Exposure to IH is the most widely used animal model of sleep apnea, short-term IH exposure resulting in cognitive and neuronal impairment. Pigment epithelium-derived factor (PEDF) is a hypoxia-sensitive factor acting as a neurotrophic, neuroprotective, and antiangiogenic agent. Our study analyzed performance on learning and cognitive tasks, as well as PEDF gene expression and PEDF protein expression in specific brain structures, in rats exposed to long-term IH. Methods: Male Wistar rats were exposed to IH (oxygen concentrations of 21-5%) for 6 weeks-the chronic IH (CIH) group-or normoxia for 6 weeks-the control group. After CIH exposure, a group of rats were allowed to recover under normoxic conditions for 2 weeks (the CIH+N group). All rats underwent the Morris water maze test for learning and memory, PEDF gene expression and PEDF protein expression in the hippocampus, frontal cortex, and temporal cortex being subsequently assessed. Results: The CIH and CIH+N groups showed increased PEDF gene expression in the temporal cortex, PEDF protein expression remaining unaltered. PEDF gene expression and PEDF protein expression remained unaltered in the frontal cortex and hippocampus. Long-term exposure to IH did not affect cognitive function. Conclusions: Long-term exposure to IH selectively increases PEDF gene expression at the transcriptional level, although only in the temporal cortex. This increase is probably a protective mechanism against IH-induced injury.

Keywords: Sleep apnea, central; Disease models, animal; Cognition; Sleep; Sleep apnea, obstructive.