Respiratory care for the critical patients with 2019 novel coronavirus.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through respiratory droplets, aerosols and close contact. Cross infections occur because viruses spread rapidly among humans. Nineteen percent (19%) of the infected patients developed severe pneumonia and acute respiratory distress syndrome (ARDS). Hypoxemia usually occurs and patients may require oxygen therapy or mechanical ventilation (MV) support. In this article, recently published clinical experience and observational studies were reviewed. Corresponding respiratory therapy regarding different stages of infection is proposed. Infection control principles and respiratory strategies including oxygen therapy, non-invasive respiratory support (NIRS), intubation evaluation, equipment preparation, ventilator settings, special maneuvers comprise of the prone position (PP), recruitment maneuver (RM), extracorporeal membrane oxygenation (ECMO), weaning and extubation are summarized. Respiratory equipment and device disinfection recommendations are worked up. We expect this review article could be used as a reference by healthcare workers in patient care while minimizing the risk of environmental contamination.

Lung ventilation distribution in patients after traditional full sternotomy and minimally invasive thoracotomy: An observational study.

BACKGROUND: The aim of the study was to examine the post-operative ventilation distribution changes in cardiac surgical patients after traditional full sternotomy (FS) or minimally invasive thoracotomy (MIT). METHODS: A total of 40 patients scheduled for FS with two-lung ventilation or MIT with one-lung ventilation were included. Ventilation distribution was measured with electrical impedance tomography (EIT) at T1, before surgery; T2, after surgery in ICU before weaning; T3, 24 hours after extubation. EIT-based parameters were calculated to assess the ventilation distribution, including the left-to-right lung ratio, ventral-to-dorsal ratio, and the global inhomogeneity index. RESULTS: The global inhomogeneity index increased at T2 and T3 compared to T1 in all patients but only statistically significant in patients with MIT (FS, P = .06; MIT, P < .01). Notable decrease in the dorsal regions (FS) or in the non-ventilated side (MIT) was observed at T2. Ventilation distribution was partially improved at T3 but huge variations of recovery progresses were found in all patients regardless of the surgery types. Subgroup analysis indicated that operation duration was significantly lower in the MIT group (240 ± 40 in FS vs 205 ± 90 minutes in MIT, median ± interquartile range, P < .05) but the incidence of atrial fibrillation/flutter was significantly higher (5% in FS vs 50% in MIT, P < .01). Other exploratory outcomes showed no statistical differences. CONCLUSIONS: Ventilation distribution was impaired after cardiac surgery. The recovery process of ventilation homogeneity was strongly depending on individuals so that MIT was not always superior in this aspect. EIT may help to identify the patients requiring further care after surgery.

Post-intensive care unit respiratory failure in older patients liberated from intensive care unit and ventilator: The predictive value of the National Early Warning Score on intensive care unit discharge.

AIM: The older adult population is continuously growing worldwide and there is increasing use of medical recourse in older patients, especially for those requiring intensive care unit (ICU) care and mechanical ventilation (MV). The present study aimed to investigate the burden and predictors of post-ICU respiratory failure in older ICU patients weaned from MV. METHODS: In the present retrospective study, older ICU patients aged ≥60 years, who were successfully weaned from MV and discharged to the general ward from the ICU of Taipei Veterans General Hospital, Taipei, Taiwan, in 2011, were included. Biomarkers on ICU discharge, as well as the National Early Warning Score (NEWS) were recorded and calculated. The outcome measure was post-ICU respiratory failure before day 14 (PIRF-14) requiring reinstitution of MV. Logistical regression was used to assess the predictors for PIRF-14. RESULTS: Of 272 patients included, 23 (8.5%) developed PIRF-14. The post-ICU in-hospital mortality rates were 47.8% and 6.8% in patients with and without PIRF-14 (adjusted OR 12.597, 95% CI 4.368-36.331). In a multivariate analysis, the levels of NEWS and hemoglobin on ICU discharge were independent predictors for PIRF-14 (adjusted OR 1.273, 95% CI 1.076-1.507 and 0.645, 95% CI 0.474-0.879). In particular, patients with a NEWS of ≥10 and subsequent PIRF-14 had a 15-fold increased risk of mortality as compared with those without both factors (adjusted OR 15.418, 95% CI 4.344-54.720). CONCLUSIONS: PIRF-14 is associated with high mortality in older ICU patients, and NEWS is a significant predictor for PIRF-14, which could be used to early identify patients at risk of post-ICU respiratory failure in the specific population. Geriatr Gerontol Int 2019; 19: 317-322.

Increased Risk of Post-Trauma Stroke after Traumatic Brain Injury-Induced Acute Respiratory Distress Syndrome.

This study determines whether acute respiratory distress syndrome (ARDS) is an independent risk factor for an increased risk of post-traumatic brain injury (TBI) stroke during 3-month, 1-year, and 5-year follow-ups, respectively, after adjusting for other covariates. Clinical data for the analysis were from the National Health Insurance Database 2000, which covered a total of 2121 TBI patients and 101 patients with a diagnosis of TBI complicated with ARDS (TBI-ARDS) hospitalized between January 1, 2001 and December 31, 2005. Each patient was tracked for 5 years to record stroke occurrences after discharge from the hospital. The prognostic value of TBI-ARDS was evaluated using a multivariate Cox proportional hazard model. The main outcome found that stroke occurred in nearly 40% of patients with TBI-ARDS, and the hazard ratio for post-TBI stroke increased fourfold during the 5-year follow-up period after adjusting for other covariates. The increased risk of hemorrhagic stroke in the ARDS group was considerably higher than in the TBI-only cohort. This is the first study to report that post-traumatic ARDS yielded an approximate fourfold increased risk of stroke in TBI-only patients. We suggest intensive and appropriate medical management and intensive follow-up of TBI-ARDS patients during the beginning of the hospital discharge.

Urinary neutrophil gelatinase-associated lipocalin is associated with heavy metal exposure in welding workers.

Metals cause nephrotoxicity with acute and/or chronic exposure; however, few epidemiological studies have examined impacts of exposure to metal fumes on renal injury in welding workers. In total, 66 welding workers and 12 office workers were recruited from a shipyard located in southern Taiwan. Urine samples from each subject were collected at the beginning (baseline) and end of the work week (1-week exposure). Personal exposure to PM2.5 was measured. The 8-h mean PM2.5 was 50.3 µg/m(3) for welding workers and 27.4 µg/m(3) for office workers. iTRAQs coupled with LC-MS/MS were used to discover the pathways in response to welding PM2.5 in the urine, suggesting that extracellular matrix (ECM)-receptor interactions are a critical mechanism. ECM-receptor interaction-related biomarkers for renal injury, kidney injury molecule (KIM)-1 and neutrophil gelatinase-associated lipocalin (NGAL), were significantly elevated in welding workers post-exposure, as well as were urinary Al, Cr, Mn, Fe, Co, and Ni levels. NGAL was more significantly associated with Al (r = 0.737, p < 0.001), Cr (r = 0.705, p < 0.001), Fe (r = 0.709, p < 0.001), and Ni (r = 0.657, p < 0.001) than was KIM-1, suggesting that NGAL may be a urinary biomarker for welding PM2.5 exposure. Nephrotoxicity (e.g., renal tubular injury) may be an emerging concern in occupational health.

Cigarette smoke is a risk factor for severity and treatment outcome in patients with culture-positive tuberculosis.

OBJECTIVE: Smoking has been associated with tuberculosis (TB); however, the effects of smoking on the effectiveness of TB treatment remain unclear. MATERIALS AND METHODS: Data were retrieved from case notes and interviews of subjects registered in the TB-reporting system from 2010 to 2012. Study cases were defined as subjects with TB-positive sputum cultures, whereas the controls were defined as subjects with non-TB-related pulmonary diseases. Statistical analyses included logistic regression and multivariate Cox proportional hazard regression models. RESULTS: A total of 245 cases with cultures positive for TB and 114 controls with non-TB-related pulmonary diseases and negative sputum cultures were recruited. Current smokers had the highest failure rate (33%) for TB treatment, and they had the most severe pulmonary lesions based on chest X-ray grading. Current smokers had a 1.36-fold (95% confidence interval 1.03-2.36, P<0.05) higher odds ratio for cultures positive for TB compared with nonsmokers. In subjects with TB-positive cultures, current smoking was associated with an increase in treatment days required for cultures to convert from positive to negative (hazard ratio 1.12, 95% confidence interval 1.03-1.39; P<0.05). CONCLUSION: Longer periods of treatment may be required for TB patients who are current smokers.

Development of a method for manufacturing customized nasal mask cushion for CPAP therapy.

A continuous positive airway pressure (CPAP) device is considered one of the most effective treatments for obstructive sleep apnea (OSA). However, many patients receiving this treatment complain of mask discomfort and other issues. Therefore, this study aimed to develop a customized nasal mask cushion to reduce the discomfort associated with conventional masks. First, a 3D face scanner was used to obtain 3D facial data of participants. Second, a model of the face was created by reverse-engineering and then used for the computer-aided design (CAD) of the cushion. Finally, computer numerical control (CNC) was used to manufacture the mold, into which silicone was then injected slowly. A perceived comfort questionnaire was used to compare the customized and conventional cushions. 40 patients were randomly divided into two groups: 20 patients in the control group used a conventional cushion, and the remaining 20 patients used the customized cushion. The customized cushion was found to be superior to the conventional cushion. There are clear differences in the headgear force of the two cushion types (P = 0.001). The customized cushion applied less force to a patient's face than a conventional cushion. Furthermore, there were obvious differences in the fit of the cushions (P = 0.001). Patients using the customized cushions experienced a better fit than those using the conventional cushions. This study has developed a new method for manufacturing customized cushions with better cushion fit through rapid tooling.

Proteoglycan 4 is a diagnostic biomarker for COPD.

INTRODUCTION: The measurement of C-reactive protein (CRP) to confirm the stability of COPD has been reported. However, CRP is a systemic inflammatory biomarker that is related to many other diseases. OBJECTIVE: The objective of this study is to discover a diagnostic biomarker for COPD. METHODS: Sixty-one subjects with COPD and 15 healthy controls (10 healthy non-smokers and 5 smokers) were recruited for a 1-year follow-up study. Data regarding the 1-year acute exacerbation frequency and changes in lung function were collected. CRP and the identified biomarkers were assessed in the validation COPD cohort patients and healthy subjects. Receiver operating characteristic values of CRP and the identified biomarkers were determined. A validation COPD cohort was used to reexamine the identified biomarker. Correlation of the biomarker with 1-year lung function decline was determined. RESULTS: Proteoglycan 4 (PRG4) was identified as a biomarker in COPD. The serum concentrations of PRG4 in COPD Global initiative for chronic Obstructive Lung Disease (GOLD) stages 1+2 and 3+4 were 10.29 ng/mL and 13.20 ng/mL, respectively; 4.99 ng/mL for healthy controls (P<0.05); and 4.49 ng/mL for healthy smokers (P<0.05). PRG4 was more sensitive and specific than CRP for confirming COPD severity and acute exacerbation frequency. There was no correlation between CRP and PRG4 levels, and PRG4 was negatively correlated with the 1-year change in predicted forced vital capacity percent (R (2)=0.91, P=0.013). CONCLUSION: PRG4 may be a biomarker for identification of severity in COPD. It was related to the 1-year forced vital capacity decline in COPD patients.

Improvement in the Prediction of Ventilator Weaning Outcomes by an Artificial Neural Network in a Medical ICU.

BACKGROUND: Twenty-five to 40% of patients pass a spontaneous breathing trial (SBT) but fail to wean from mechanical ventilation. There is no single appropriate and convenient predictor or method that can help clinicians to accurately predict weaning outcomes. This study designed an artificial neural network (ANN) model for predicting successful extubation in mechanically ventilated patients. METHODS: Ready-to-wean subjects (N = 121) hospitalized in medical ICUs were recruited and randomly divided into training (n = 76) and test (n = 45) sets. Eight variables consisting of age, reasons for intubation, duration of mechanical ventilation, Acute Physiology and Chronic Health Evaluation II score, mean inspiratory and expiratory times, mean breathing frequency, and mean expiratory tidal volume in a 30-min SBT (pressure support ventilation of 5 cm H2O and PEEP of 5 cm H2O) were selected as the ANN input variables. The prediction performance of the ANN model was compared with the rapid shallow breathing index (RSBI), maximum inspiratory pressure, RSBI at 1 min (RSBI1) and 30 min (RSBI30) in an SBT, and absolute percentage change in RSBI from 1 to 30 min in an SBT (ΔRSBI30) using a confusion matrix and receiver operating characteristic curves. RESULTS: The area under the receiver operating characteristic curves in the test set of the ANN model was 0.83 (95% CI 0.69-0.92, P < .001), which is better than any one of the following predictors: 0.66 (95% CI 0.50-0.80, P = .04) for RSBI, 0.52 (95% CI 0.37-0.67, P = .86) for maximum inspiratory pressure, 0.53 (95% CI 0.37-0.68, P = .79) for RSBI1, 0.60 (95% CI 0.44-0.74, P = .34) for RSBI30, and 0.51 (95% CI 0.36-0.66, P = .91) for ΔRSBI30. Predicting successful extubation based on the ANN model of the test set had a sensitivity of 82%, a specificity of 73%, and an accuracy rate of 80%, with an optimal threshold of ≥ 0.5 selected from the training set. CONCLUSIONS: The ANN model improved the accuracy of predicting successful extubation. By applying it clinically, clinicians can select the earliest appropriate weaning time.

Inhaled Pharmacotherapy and Stroke Risk in Patients with Chronic Obstructive Pulmonary Disease: A Nationwide Population Based Study Using Two-Stage Approach.

BACKGROUND AND PURPOSE: Patients with chronic obstructive pulmonary disease (COPD) are at higher risk of stroke than those without COPD. This study aims to explore the impact of inhaled pharmacotherapy on stroke risk in COPD patients during a three-year follow-up, using a nationwide, population-based study and a matched cohort design. METHODS: The study cohort comprised 10,413 patients who had received COPD treatment between 2004 and 2006; 41,652 randomly selected subjects comprised the comparison cohort. Cox proportional hazard regressions and two-stage propensity score calibration were performed to determine the impact of various inhaled therapies including short-acting muscarinic antagonists, long-acting muscarinic antagonists, short-acting ß-agonists (SABAs), long-acting ß-agonists (LABAs), and LABA plus inhaled corticosteroid (ICS), on the risk after adjustment for patient demographic characteristics and comorbid disorders. RESULTS: Of the 52,065 sampled patients, 2,689 (5.2%) developed stroke during follow-up, including 727 (7.0%) from the COPD cohort and 1,962 (4.7%) from the comparison cohort (p < 0.001). Treatment with SABA was associated with 1.67-fold (95% CI 1.45-1.91; p < 0.001) increased risk of stroke in COPD patients. By contrast, the cumulative incidence of stroke was significantly lower in those treated with LABA plus ICS than those treated without (adjusted hazard ratio 0.75, 95% CI 0.60-0.94, p = 0.014). CONCLUSIONS: Among COPD patients, the use of inhaled SABA is associated with an increased risk of stroke, and combination treatment with inhaled LABA and ICS relates to a risk reduction. Further prospective research is needed to verify whether LABA plus ICS confers protection against stroke in patients with COPD.

Dysfunction of methionine sulfoxide reductases to repair damaged proteins by nickel nanoparticles.

BACKGROUND: Protein oxidation is considered to be one of the main causes of cell death, and methionine is one of the primary targets of reactive oxygen species (ROS). However, the mechanisms by which nickel nanoparticles (NiNPs) cause oxidative damage to proteins remain unclear. OBJECTIVES: The objective of this study is to investigate the effects of NiNPs on the methionine sulfoxide reductases (MSR) protein repairing system. METHODS: Two physically similar nickel-based nanoparticles, NiNPs and carbon-coated NiNP (C-NiNPs; control particles), were exposed to human epithelial A549 cells. Cell viability, benzo(a)pyrene diolepoxide (BPDE) protein adducts, methionine oxidation, MSRA and B3, microtubule-associated protein 1A/1B-light chain 3 (LC3) and extracellular signal-regulated kinase (ERK) phosphorylation were investigated. RESULTS: Exposure to NiNPs led to a dose-dependent reduction in cell viability and increased BPDE protein adduct production and methionine oxidation. The methionine repairing enzymatic MSRA and MSRB3 production were suppressed in response to NiNP exposure, suggesting the oxidation of methionine to MetO by NiNP was not reversed back to methionine. Additionally, LC3, an autophagy marker, was down-regulated by NiNPs. Both NiNP and C-NiNP caused ERK phosphorylation. LC3 was positively correlated with MSRA (r = 0.929, p < 0.05) and MSRB3 (r = 0.893, p < 0.05). CONCLUSIONS: MSR was made aberrant by NiNP, which could lead to the dysfunction of autophagy and ERK phosphorylation. The toxicological consequences may be dependent on the chemical characteristics of the nanoparticles.

VEGF correlates with inflammation and fibrosis in tuberculous pleural effusion.

OBJECTIVE: To investigate the relationship among angiogenic cytokines, inflammatory markers, and fibrinolytic activity in tuberculous pleural effusion (TBPE) and their clinical importance. METHODS: Forty-two patients diagnosed with TBPE were studied. Based on chest ultrasonography, there were 26 loculated and 16 nonloculated TBPE patients. The effusion size radiological scores and effusion vascular endothelial growth factor (VEGF), interleukin- (IL-) 8, plasminogen activator inhibitor type-1 (PAI-1), and tissue type plasminogen activator (tPA) were measured. Treatment outcome and pleural fibrosis, defined as radiological residual pleural thickening (RPT), were assessed at 6-month follow-up. RESULTS: The effusion size and effusion lactate dehydrogenase (LDH), VEGF, IL-8, PAI-1, and PAI-1/tPA ratio were significantly higher, while effusion glucose, pH value, and tPA were significantly lower, in loculated than in nonloculated TBPE. VEGF and IL-8 correlated positively with LDH and PAI-1/tPA ratio and negatively with tPA in both loculated and nonloculated TBPE. Patients with higher VEGF or greater effusion size were prone to develop RPT (n=14; VEGF, odds ratio 1.28, P=0.01; effusion size, odds ratio 1.01, P=0.02), and VEGF was an independent predictor of RPT in TBPE (receiver operating characteristic curve AUC=0.985, P<0.001). CONCLUSIONS: Effusion VEGF correlates with pleural inflammation and fibrosis and may be targeted for adjunct therapy for TBPE.

Clinical verification of patients with obstructive sleep apnea provided with a customized cushion for continuous positive airway pressure.

STATEMENT OF PROBLEM: Patients with obstructive sleep apnea may stop breathing momentarily during sleep because of a narrow upper respiratory tract. One of the main treatments for obstructive sleep apnea is continuous positive airway pressure. However, after long-term treatment, patients tend to complain about the leakage, inconvenience, and discomfort of the nasal mask. PURPOSE: The purpose of the study was to develop customized cushions and compare the clinical performance of the customized cushion with the conventional one. MATERIAL AND METHODS: Each participant's face was replicated by using a 3-dimensional scanner and reverse-engineering technology, and computer numerical control techniques were used to design and manufacture customized cushions. Forty participants were randomly divided into 2 groups, a control group with conventional cushions and an experimental group with customized cushions. The saturation level of peripheral oxygen, apnea-hypopnea index, leakage data, and answers to a comfort questionnaire were examined. RESULTS: Customized and conventional cushions were compared with independent sampling t tests and relational analyses. A significant difference was found in the apnea-hypopnea index (P=.001) of participants with the customized cushion and those with the conventional cushion. Participants with the conventional cushion had a lower apnea-hypopnea index. The customized cushion applied less headgear force and fit better than the conventional cushion. The leakage volume, saturation of peripheral oxygen (SpO2), treatment compliance, and degree of comfort were not significantly different between the groups. CONCLUSIONS: Customized nasal mask cushions fit better and reduce the force applied by the headgear. Participants using a customized cushion showed an improved apnea-hypopnea index.

CXCL12 induces connective tissue growth factor expression in human lung fibroblasts through the Rac1/ERK, JNK, and AP-1 pathways.

CXCL12 (stromal cell-derived factor-1, SDF-1) is a potent chemokine for homing of CXCR4+ fibrocytes to injury sites of lung tissue, which contributes to pulmonary fibrosis. Overexpression of connective tissue growth factor (CTGF) plays a critical role in pulmonary fibrosis. In this study, we investigated the roles of Rac1, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and activator protein-1 (AP-1) in CXCL12-induced CTGF expression in human lung fibroblasts. CXCL12 caused concentration- and time-dependent increases in CTGF expression and CTGF-luciferase activity. CXCL12-induced CTGF expression was inhibited by a CXCR4 antagonist (AMD3100), small interfering RNA of CXCR4 (CXCR4 siRNA), a dominant negative mutant of Rac1 (RacN17), a mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor (PD98059), a JNK inhibitor (SP600125), a p21-activated kinase inhibitor (PAK18), c-Jun siRNA, and an AP-1 inhibitor (curcumin). Treatment of cells with CXCL12 caused activations of Rac1, Rho, ERK, and c-Jun. The CXCL12-induced increase in ERK phosphorylation was inhibited by RacN17. Treatment of cells with PD98059 and SP600125 both inhibited CXCL12-induced c-Jun phosphorylation. CXCL12 caused the recruitment of c-Jun and c-Fos binding to the CTGF promoter. Furthermore, CXCL12 induced an increase in α-smooth muscle actin (α-SMA) expression, a myofibroblastic phenotype, and actin stress fiber formation. CXCL12-induced actin stress fiber formation and α-SMA expression were respectively inhibited by AMD3100 and CTGF siRNA. Taken together, our results suggest that CXCL12, acting through CXCR4, activates the Rac/ERK and JNK signaling pathways, which in turn initiates c-Jun phosphorylation, and recruits c-Jun and c-Fos to the CTGF promoter and ultimately induces CTGF expression in human lung fibroblasts. Moreover, overexpression of CTGF mediates CXCL12-induced α-SMA expression.

Epidermal growth factor stimulates nuclear factor-κB activation and heme oxygenase-1 expression via c-Src, NADPH oxidase, PI3K, and Akt in human colon cancer cells.

Previous report showed that epidermal growth factor (EGF) promotes tumor progression. Several studies demonstrated that growth factors can induce heme oxygenase (HO)-1 expression, protect against cellular injury and cancer cell proliferation. In this study, we investigated the involvement of the c-Src, NADPH oxidase, reactive oxygen species (ROS), PI3K/Akt, and NF-κB signaling pathways in EGF-induced HO-1 expression in human HT-29 colon cancer cells. Treatment of HT-29 cells with EGF caused HO-1 to be expressed in concentration- and time-dependent manners. Treatment of HT-29 cells with AG1478 (an EGF receptor (EGFR) inhibitor), small interfering RNA of EGFR (EGFR siRNA), a dominant negative mutant of c-Src (c-Src DN), DPI (an NADPH oxidase inhibitor), glutathione (an ROS inhibitor), LY294002 (a PI3K inhibitor), and an Akt DN inhibited EGF-induced HO-1 expression. Stimulation of cells with EGF caused an increase in c-Src phosphorylation at Tyr406 in a time-dependent manner. Treatment of HT-29 cells with EGF induced an increase in p47(phox) translocation from the cytosol to membranes. The EGF-induced ROS production was inhibited by DPI. Stimulation of cells with EGF resulted in an increase in Akt phosphorylation at Ser473, which was inhibited by c-Src DN, DPI, and LY 294002. Moreover, treatment of HT-29 cells with a dominant negative mutant of IκB (IκBαM) inhibited EGF-induced HO-1 expression. Stimulation of cells with EGF induced p65 translocation from the cytosol to nuclei. Treatment of HT-29 cells with EGF induced an increase in κB-luciferase activity, which was inhibited by a c-Src DN, LY 294002, and an Akt DN. Furthermore, EGF-induced colon cancer cell proliferation was inhibited by Sn(IV)protoporphyrin-IX (snPP, an HO-1 inhibitor). Taken together, these results suggest that the c-Src, NADPH oxidase, PI3K, and Akt signaling pathways play important roles in EGF-induced NF-κB activation and HO-1 expression in HT-29 cells. Moreover, overexpression of HO-1 mediates EGF-induced colon cancer cell proliferation.

Effects of size and surface of zinc oxide and aluminum-doped zinc oxide nanoparticles on cell viability inferred by proteomic analyses.

Although the health effects of zinc oxide nanoparticles (ZnONPs) on the respiratory system have been reported, the fate, potential toxicity, and mechanisms in biological cells of these particles, as related to particle size and surface characteristics, have not been well elucidated. To determine the physicochemical properties of ZnONPs that govern cytotoxicity, we investigated the effects of size, electronic properties, zinc concentration, and pH on cell viability using human alveolar-basal epithelial A549 cells as a model. We observed that a 2-hour or longer exposure to ZnONPs induced changes in cell viability. The alteration in cell viability was associated with the zeta potentials and pH values of the ZnONPs. Proteomic profiling of A549 exposed to ZnONPs for 2 and 4 hours was used to determine the biological mechanisms of ZnONP toxicity. p53-pathway activation was the core mechanism regulating cell viability in response to particle size. Activation of the Wnt and TGFß signaling pathways was also important in the cellular response to ZnONPs of different sizes. The cadherin and Wnt signaling pathways were important cellular mechanisms triggered by surface differences. These results suggested that the size and surface characteristics of ZnONPs might play an important role in their observed cytotoxicity. This approach facilitates the design of more comprehensive systems for the evaluation of nanoparticles.

Physicochemical and biological characterization of single-walled and double-walled carbon nanotubes in biological media.

To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-α) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.

Methionine oxidation in albumin by fine haze particulate matter: an in vitro and in vivo study.

The potential effects of inhaled fine particulate matter (PM2.5), found in haze episodes, on the oxidation of the proteins in the lungs are not well understood. We investigated the effects of PM2.5 from haze episodes on protein oxidation. PM2.5 was collected from the air pollution in Beijing (BJ), Xian (XA), Xiamen (XM) and Hong Kong (HK) during a period of intensive haze episodes. The chemical characteristics of these samples and their effects on albumin oxidation were investigated. The levels of PM2.5 in BJ and XA were 4-6 times higher than in XM and HK. The concentrations of the polycyclic aromatic hydrocarbons (PAHs) components of the PM2.5 from BJ and XA were 10 times higher than those found in XM and HK. The haze PM2.5 increased oxidative stress. Addition of PM2.5 samples collected from haze episodes to albumin in vitro resulted in oxidation of methionine moieties; nasal instillation of PM2.5 suspensions in mice resulted in oxidation of methionine in the albumin in the bronchoalveolar lavage fluid. The methionine moieties participate in peptide chain crosslinking, and methionine oxidation in the albumin could be attributed to the PAH compounds. Our findings may be helpful in explaining the potential respiratory effects during haze episodes.

Role of VEGF-C gene polymorphisms in susceptibility to hepatocellular carcinoma and its pathological development.

BACKGROUND: Vascular endothelial growth factor C (VEGF-C), an angiogenic/lymphangiogenic factor with high expression levels in tumor tissues, plays important roles in the development of several malignancies including hepatocellular carcinoma (HCC). The purpose of this study was to examine whether VEGF-C gene polymorphisms are associated with susceptibility to HCC and its clinicopathological development. METHODS: Genetic polymorphisms of VEGF-C of 135 patients with HCC and 520 noncancer controls were analyzed by a real-time polymerase chain reaction (PCR). RESULTS: We found that a significantly (P = 0.021) higher risk for HCC was shown in individuals with the VEGF-C rs1485766 A/A genotype compared to those with wild-type homozygotes; a high frequency of an advanced stage and a low frequency of being positive for cirrhosis were respectively shown in HCC patients with the VEGF-C rs7664413 CT/TT and rs3775194 GC/CC genotypes. Moreover, we found that the GGACA, GACTG, CGATG, and GGCTG haplotypes of five VEGF-C single-nucleotide polymorphisms (SNPs) combined were also related to the risk of HCC. CONCLUSIONS: Our results suggest that the VEGF-C rs1485766 SNP and either of five haplotypes combined might contribute to a prediction of susceptibility to HCC. The genetic polymorphism of VEGF-C rs7664413 might be a predictive factor for advanced-stage HCC.

Evaluating physiological dynamics via synchrosqueezing: prediction of ventilator weaning.

Oscillatory phenomena abound in many types of signals. Identifying the individual oscillatory components that constitute an observed biological signal leads to profound understanding about the biological system. The instantaneous frequency (IF), the amplitude modulation (AM), and their temporal variability are widely used to describe these oscillatory phenomena. In addition, the shape of the oscillatory pattern, repeated in time for an oscillatory component, is also an important characteristic that can be parametrized appropriately. These parameters can be viewed as phenomenological surrogates for the hidden dynamics of the biological system. To estimate jointly the IF, AM, and shape, this paper applies a novel and robust time-frequency analysis tool, referred to as the synchrosqueezing transform (SST). The usefulness of the model and SST are shown directly in predicting the clinical outcome of ventilator weaning. Compared with traditional respiration parameters, the breath-to-breath variability has been reported to be a better predictor of the outcome of the weaning procedure. So far, however, all these indices normally require at least 20 min of data acquisition to ensure predictive power. Moreover, the robustness of these indices to the inevitable noise is rarely discussed. We find that based on the proposed model, SST and only 3 min of respiration data, the ROC area under curve of the prediction accuracy is 0.76. The high predictive power that is achieved in the weaning problem, despite a shorter evaluation period, and the stability to noise suggest that other similar kinds of signal may likewise benefit from the proposed model and SST.