The impact of PM2.5 on the human respiratory system.

Recently, many researchers paid more attentions to the association between air pollution and respiratory system disease. In the past few years, levels of smog have increased throughout China resulting in the deterioration of air quality, raising worldwide concerns. PM2.5 (particles less than 2.5 micrometers in diameter) can penetrate deeply into the lung, irritate and corrode the alveolar wall, and consequently impair lung function. Hence it is important to investigate the impact of PM2.5 on the respiratory system and then to help China combat the current air pollution problems. In this review, we will discuss PM2.5 damage on human respiratory system from epidemiological, experimental and mechanism studies. At last, we recommend to the population to limit exposure to air pollution and call to the authorities to create an index of pollution related to health.

Correlation of Epworth Sleepiness Scale with multiple sleep latency test and its diagnostic accuracy in assessing excessive daytime sleepiness in patients with obstructive sleep apnea hypopnea syndrome.

BACKGROUND: Excessive daytime sleepiness (EDS) is often associated with obstructive sleep apnea hypopnea syndrome (OSAHS) and contributes to a number of comorbidities in these patients. Therefore, early detection of EDS is critical in disease management. We examined the association between Epworth Sleepiness Scale (ESS) and multiple sleep latency test (MSLT) and diagnostic accuracy of ESS in assessing EDS in OSAHS patients. METHODS: The ESS, MSLT and overnight polysomnography were administered to 107 Chinese patients to assess EDS and its correlations with polysomnographic parameters. The diagnostic accuracy of ESS in classifying EDS (mean sleep latency (MSL) ≤ 10 minutes) was evaluated by calculating the area under ROC curve. RESULTS: As the severity of OSAHS increased, MSL decreased with increase in ESS score. Conversely, patients with worsening EDS (shorter MSL) were characterized by advanced nocturnal hypoxaemia and sleep disruption compared to those with normal MSL, suggesting EDS is associated with more severe OSAHS. There was a negative correlation between ESS score and MSL and both moderately correlated with some polysomnographic nocturnal hypoxaemic parameters. The area under ROC curve of ESS for identifying EDS was 0.80 (95% CI: 0.71 to 0.88) and ESS score ≥ 12 provided the best predictive value with a sensitivity of 80% and specificity of 69%. CONCLUSION: The ESS score moderately correlates with MSL and our ROC study supports ESS as a screening strategy for assessing EDS in OSAHS.

Effect of protein-tyrosine phosphatase 4A3 by small interfering RNA on the proliferation of lung cancer.

Previous studies on PTP4A3 mainly focused on tumor metastasis due to the close relationship between the overexpression of lung cancer and metastasis. However, the role of PTP4A3 in the proliferation of tumor still has remained unclear. To investigate the role of PTP4A3 in cell growth of lung cancer, we constructed PTP4A3-siRNA expressing lentivirus and infected human lung cancer H1299 cells, and then examined the inhibitory effect of PTP4A3 in vitro. The levels of PTP4A3 mRNA and protein in H1299 cells decreased after PTP4A3-siRNA lentivirus infection. The growth and colony formation of the infected cells were also inhibited, indicating that PTP4A3 gene is closely associated with the proliferation of H1299 cells. In addition, after PTP4A3 specific siRNA lentivirus infection, it was notable that whilst H1299 cells in G1 phase apparently reduced, both of H1299 cells in G2/M phase and the cell apoptosis increased significantly. This finding indicated the close relationship between PTP4A3 gene and apoptosis in the H1299 cells. These results come to their conclusion that PTP4A3 plays an important role in the growth of lung cancer cells. PTP4A3 may be considered as a valuable target for anti-tumor therapeutic strategies.

Neurocognitive impairment in Chinese patients with obstructive sleep apnoea hypopnoea syndrome.

BACKGROUND AND OBJECTIVE: Sleep-disordered breathing is known to be associated with impairment in cognitive function. The aim of this study was to characterize neurocognitive impairment in a cohort of Chinese patients with varying severities of obstructive sleep apnoea hypopnoea syndrome (OSAHS), and to develop a sensitive instrument for routine screening of cognitive impairment. METHODS: Eligible patients (n = 394) were categorized into a primary snoring group, and mild, moderate and severe OSAHS groups, based on assessment of AHI. The Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) questionnaires were administered to assess cognitive function, and the correlations between questionnaire scores and clinical and polysomnographic parameters were further evaluated by stepwise multivariate regression. RESULTS: MoCA scores decreased progressively across the spectrum from primary snoring to severe OSAHS. Importantly, mild neurocognitive impairment as defined by a MoCA score <26 was more common in the moderate (38.6%) and severe (41.4%) OSAHS groups than in the mild OSAHS (25.0%) and primary snoring (15.2%) groups. In contrast, MMSE scores were largely normal and comparable among all four groups. Evaluation of MoCA subdomains further revealed selective reduction in memory/delayed recall, visuospatial and executive function, and attention span in the severe OSAHS group compared with the other groups. Stepwise multivariate regression analysis demonstrated that MoCA scores correlated significantly with lowest oxygen saturation (L-SaO(2) ) and years of education. CONCLUSIONS: Neurocognitive impairment is common in patients with OSAHS. The MoCA is a brief and sensitive tool for the assessment of cognitive impairment in OSAHS patients, whose performance on the MMSE is in the normal range.

Daytime sleepiness and its determining factors in Chinese obstructive sleep apnea patients.

OBJECTIVE: The aim of this study was to characterize excessive daytime sleepiness (EDS) in a large cohort of Chinese patients with various severity of obstructive sleep apnea-hypopnea syndrome (OSAHS), and investigate its correlations with clinical/polysomnographic variables. MATERIALS AND METHODS: A total of 1,035 consecutive Chinese patients with snoring (mean age ± SD 45 ± 15 years, BMI 26.6 ± 4.3 kg/m(2)) were examined by overnight polysomnography, and subjective EDS was assessed using the Epworth Sleepiness Scale (ESS). RESULTS: The 1,035 patients were compared according to severity of sleep-disordered breathing: AHI <5 (primary snoring group or normal overall AHI) (24.1%), AHI 5-20 (mild OSAHS, 21.7%), AHI >20-40 (moderate OSAHS 16.5%), and AHI >40 (severe OSAHS 37.7%). ESS score progressively increased as the severity of OSAHS aggravated among these patients. More severe OSAHS patients were characterized by EDS, nocturnal hypoxemia, and disruption of sleep structure. Progressive worsening of nocturnal hypoxemia was observed from mild to severe OSAHS patients with a strong correlation with ESS score. The stepwise multiple regression analysis performed to evaluate the correlations of individual clinical and polysomnographic variables with the ESS score revealed that the ESS score significantly correlated with the oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and body mass index (BMI), and ODI was the strongest determinant of ESS score. CONCLUSION: EDS is correlated with the severity of OSAHS. More severe patients are characterized by higher ESS score, higher BMI, and progressive worsening of nocturnal hypoxemia. Nocturnal hypoxemia is a major determinant of EDS in Chinese OSAHS patients.