[Show abstract][Hide abstract] ABSTRACT: This study investigated cytotoxicity, particularly autophagy, in RAW264.7 cells exposed to graphene oxide (GO) and its derivatives (dodecylamine-GO (DA-GO), reduced GO (rGO), and sodium dodecyl sulfate-rGO (SDS-rGO)). Appearance of amine stretching bands, out-of-plane C-H stretching vibrations, and S=O stretching bands in infrared spectra indicated the formation of DA-GO, rGO, and SDS-rGO, respectively. Light microscopy and microculture tetrazolium assay showed that all the GO types exerted cytotoxic effects on RAW264.7 cells in a concentration-dependent manner. Higher concentrations of the GO types downregulated the expression of PU.1, a unique transcription factor in monocytes and macrophages, and decreased the conversion of LC3A/B-I to LC3A/B-II, suggesting that PU.1 was associated with autophagy in RAW264.7 cells. These results suggested that surface-functionalized GOs exerted cytotoxic effects in a concentration-dependent manner by changing the expression of critical genes and inducing autophagy in macrophages.
Preview · Article · Oct 2015 · Journal of Nanomaterials
[Show abstract][Hide abstract] ABSTRACT: Varenicline, a selective partial agonist/antagonist of the α4β2 nicotinic receptor, has proven effectiveness for smoking cessation by several randomized, controlled trials. Because few studies have evaluated the long-term efficacy of varenicline, we tried to evaluate the smoking status of varenicline users up to 3 years after the initial prescription of the drug.
We interviewed varenicline users who were prescribed the drug from June 2007 to May 2010 by telephone, from June 2010 to May 2011.
One-hundred and thirty-three of 250 varenicline users (53.2%) were available for the survey. Seven-day continuous abstinence from smoking was adhered to by 17 of 39 respondents (43.6%) at 1 year, and 11 of 36 (30.6%) and 19 of 58 (32.8%) at 2 and 3 years since the first use of varenicline, respectively. Compared to current smokers, successful quitters were older (55.0 years vs. 49.9 years, p=0.01), had better compliance to the 12-week course (27.7 vs. 9.3%, p=0.01), and had taken varenicline longer (10.1 vs. 5.9 weeks, p=0.01). Fifty-four of 71 current smokers (76.1%) were willing to stop smoking in the near future. The preferred ways to cease smoking were will-power (48.1%), varenicline (25.9%), nicotine replacement therapy (11.1%), and others (14.9%).
Smokers should be encouraged to stick to the proven way for recommended period of time for successful cessation of smoking.
[Show abstract][Hide abstract] ABSTRACT: The viability of A549 cells, a human lung carcinoma epithelial cell line, was evaluated after exposure to graphene oxide (GO) and its derivatives (dodecylamine GO (DA-GO), reduced GO (rGO), and sodium dodecyl sulfate rGO (SDS-rGO)). A decrease in the relative amounts of C — OH
bonds and an increase in the number of C —C and C —N bonds in the C 1s spectra indicated that the reduction of GO to rGO and the surface functionalization of GO has taken place. The appearance of amine stretching bands, out-of-plane C —H stretching vibrations, and S =O stretching
bands in the infrared spectra indicated the formation of DA-GO, rGO, and SDS-rGO, respectively. Low concentrations (3–25 μg/mL) of GO, rGO, and SDS-rGO were found to be mildly toxic, whereas DA-GO exhibited severe dose-dependent toxicity over the same concentration range. High
concentrations (50–400 μg/mL) of GO and all its derivatives resulted in severe toxicity to the A549 cells. It is believed that surface functionality strongly affects the viability of A549 cells.
Full-text · Article · Mar 2015 · Journal of Nanoscience and Nanotechnology
[Show abstract][Hide abstract] ABSTRACT: Antiphospholipid syndrome (APS) is an acquired systemic autoimmune disorder characterized by a combination of clinical criteria, including vascular thrombosis or pregnancy morbidity and elevated antiphospholipid antibody titers. It is one of the causes of deep vein thrombosis and pulmonary embolism that can be critical due to the mortality risk. Overall recurrence of thromboembolism is very low with adequate anticoagulation prophylaxis. The most effective treatment to prevent recurrent thrombosis is long-term anticoagulation. We report on a 17-year-old male with APS, who manifested blue toe syndrome, deep vein thrombosis, pulmonary thromboembolism, and cerebral infarction despite adequate long-term anticoagulation therapy.
Preview · Article · Dec 2014 · Tuberculosis and Respiratory Diseases
[Show abstract][Hide abstract] ABSTRACT: Respiratory infections are well-known triggers of chronic respiratory diseases. Recently, culture-independent tools have indicated that lower airway microbiota may contribute to pathophysiologic processes associated with asthma and chronic obstructive pulmonary disease (COPD). However, the relationship between upper airway microbiota and chronic respiratory diseases remains unclear. This study was undertaken to define differences of microbiota in the oropharynx of asthma and COPD patients relative to those in healthy individuals. To account for the qualitative and quantitative diversity of the 16S rRNA gene in the oropharynx, the microbiomes of 18 asthma patients, 17 COPD patients, and 12 normal individuals were assessed using a high-throughput next-generation sequencing analysis. In the 259,572 total sequence reads, α and β diversity measurements and a generalized linear model revealed that the oropharynx microbiota are diverse, but no significant differences were observed between asthma and COPD patients. Pseudomonas spp. of Proteobacteria and Lactobacillus spp. of Firmicutes were highly abundant in asthma and COPD. By contrast, Streptococcus, Veillonella, Prevotella, and Neisseria of Bacteroidetes dominated in the healthy oropharynx. These findings are consistent with previous studies conducted in the lower airways and suggest that oropharyngeal airway microbiota are important for understanding the relationships between the various parts of the respiratory tract with regard to bacterial colonization and comprehensive assessment of asthma and COPD.
[Show abstract][Hide abstract] ABSTRACT: Background:
Previous studies have investigated the relationship between occupational and environmental agents and idiopathic pulmonary fibrosis (IPF). However, there have been few studies regarding the prognosis of patients with IPF according to patient occupation.
We investigated whether occupational dust exposure was associated with clinically decreased lung function and poor prognosis. The Korean Interstitial Lung Disease Research Group conducted a national survey to evaluate the clinical, physiologic, radiologic, and survival characteristics of patients with IPF. A total of 1,311 patients with IPF were stratified into five groups according to their occupation: (1) unemployed or homemakers (n = 628); (2) farmers, fishers, or ranchers (n = 230); (3) sales or service personnel (n = 131); (4) clerical or professional personnel (n = 151); and (5) specific dust-exposed workers (n = 171).
The mean age of subjects at diagnosis, was 67.5 ± 9.7 years. Current smokers were 336 patients, 435 were exsmokers, and 456 were never smokers. Dust-exposed workers showed early onset of IPF (61.3 ± 8.6 years; P < .001) and a longer duration of symptoms at diagnosis (17.0 ± 28.2 months; P = .004). Aging (P = .001; hazard ratio [HR], 1.034; 95% CI, 1.014-1.054), FVC % predicted at diagnosis (P = .004; HR, 0.984; 95% CI, 0.974-0.995), and dust-exposure occupation (P = .033; HR, 1.813; 95% CI, 1.049-3.133) were associated with mortality.
These findings indicate that occupational dust may be an aggravating factor associated with a poor prognosis in IPF.
[Show abstract][Hide abstract] ABSTRACT: The therapeutic potential of human multipotent mesenchymal stromal cells, especially human adipose tissue-derived stem cells (hASC), is promising. However, there are concerns about the safety of infusion of hASC in human. Recently, we have experienced pulmonary embolism and infarct among family members who have taken multiple infusions of intravenous autologous hASC therapy. A 41-year-old man presented with chest pain for one month. Chest CT showed multiple pulmonary artery embolism and infarct at right lung. Serum D-dimer was 0.8 μg/mL (normal; 0-0.5 μg/mL). He had received intravenous autologous adipose tissue-derived stem cell therapy for cervical herniated intervertebral disc three times (one, two, and three months prior to the visit). His parents also received the same therapy five times and their chest CT also showed multiple pulmonary embolism. These cases represent artificial pulmonary embolisms and infarct after IV injection of hASC. Follow-up chest CT showed spontaneous resolution of lesions in all three patients.
Full-text · Article · Sep 2013 · Yonsei medical journal
[Show abstract][Hide abstract] ABSTRACT: A 69-year-old female patient visited the emergency room with fever (38.3℃) and dyspnea. She had been taking prednisolone (5 mg once per day) and methotrexate (2.5 mg once per week) for rheumatoid arthritis for 2 years. Chest computed tomography (CT) showed bilateral, multifocal ground glass opacity with interlobular septal thickening. Peripheral blood leukocyte count was 6,520/mm(3) (neutrophils, 77.4%; eosinophils, 12.1%). During the night, mechanical ventilation was initiated due to the development of severe hypoxemia. Bronchoalveolar lavage fluid showed a high proportion of eosinophils (49%). Her symptoms improved dramatically after commencement of intravenous methylprednisolone therapy. This is the first report of idiopathic acute eosinophilic pneumonia developing in a current user of systemic corticosteroids.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
To evaluate intracranial hemodynamic stabilization patterns after carotid artery stenting (CAS) in patients having variable collateral developments before CAS.
The hemodynamic and angiographic data of 62 patients (58 men; mean age 68.0±8.4 years) who underwent CAS for unilateral proximal internal carotid artery stenosis were analyzed. The patients had transcranial Doppler examinations before and at 1 and 90 days after CAS. Patients were classified according to pre-CAS mean blood flow velocity (MBFV) of the ipsilateral middle cerebral artery (MCA): low (<30 cm/s; n=17), normal (30 to 48 cm/s; n=26), or high (>48 cm/s; n=19). The collaterals from contralateral anterior and/or posterior circulations prior to CAS, the stabilization pattern of MBFV, and the pulsatility index (PI) after CAS were compared across the 3 groups.
The presence of collaterals was lowest in the low MBFV group (17.6% of patients) than in the normal (38.5%) or high (68.4%) MBFV groups (p=0.008). The low MBFV group exhibited an increase in MBFV and PI in the ipsilateral MCA at 1 and 90 days after CAS (p<0.05). By contrast, the high MBFV group exhibited a decrease in MBFV and no change in PI in the ipsilateral MCA up to 90 days after CAS (p<0.05). The normal MBFV group showed an increase in MBFV at post-CAS day 1 but a subsequent decrease at 90 days and an increase in PI in the ipsilateral MCA at 1 and 90 days post-CAS (p<0.05).
The pattern of post-CAS intracranial hemodynamic stabilization differs according to the pre-CAS MBFV in the ipsilateral MCA.
No preview · Article · May 2013 · Journal of Endovascular Therapy
[Show abstract][Hide abstract] ABSTRACT: Bronchial asthma can be triggered by microbial agents in the oropharynx. This study was designed to identify the differences in microbiota of oropharynx of bronchial asthmatic patients in contrast to normal controls. In order to resolve the qualitative and quantitative diversity of the 16S rRNA gene present in the oropharynx microbiota of 4 patients and 4 controls, we compared microbial communities using Sanger sequencing and 376 sequences of 16S rRNA gene were analyzed. Of the total microbial diversity detected in the oropharynx in asthmatic patients 45.6% comprised members of the Firmicutes. In contrast, Proteobacteria (44.0%) dominated the oropharyngeal microbiota in the normal control group. Members of the Bacteroidetes, Fusobacteria, Actinobacteria, TM7, Cyanobacteria and unclassified bacteria were present in both groups. In conclusion, the difference in the microbiota of the oropharynx between patients and normal individuals could trigger symptomatic attacks in bronchial asthma.
Preview · Article · Jan 2013 · Journal of Bacteriology and Virology
[Show abstract][Hide abstract] ABSTRACT: Previous studies have demonstrated an association of osteopenia/osteoporosis with idiopathic benign paroxysmal positional vertigo (BPPV). Since vitamin D takes part in the regulation of calcium and phosphorus found in the body and plays an important role in maintaining proper bone structure, decreased bone mineral density in patients with BPPV may be related to decreased serum vitamin D. We measured the serum levels of 25-hydroxyvitamin D in 100 patients (63 women and 37 men, mean age ± SD = 61.8 ± 11.6) with idiopathic BPPV and compared the data with those of 192 controls (101 women and 91 men, mean age ± SD = 60.3 ± 11.3) who had lived in the same community without dizziness or imbalance during the preceding year. The selection of the controls and acquisition of clinical information were done using the data from the Fourth Korean National Health and Nutrition Examination Survey, 2008. The serum level of 25-hydroxyvitamin D was lower in the patients with BPPV than in the controls (mean ± SD = 14.4 ± 8.4 versus 19.1 ± 6.8 ng/ml, p = 0.001). Furthermore, patients with BPPV showed a higher prevalence of decreased serum vitamin D (<20 ng/ml, 80.0 vs. 60.1 %, p < 0.001) than the controls. Multiple logistic regression analyses adjusted for age, sex, body mass index, hypertension, diabetes, proteinuria, regular exercise and the existence of decreased bone mineral density demonstrated that vitamin D insufficiency (10-20 ng/ml) and deficiency (<10 ng/ml) were associated with BPPV with the odds ratios of 3.8 (95 % confidence interval = 1.51-9.38, p = 0.004) and 23.0 (95 % confidence interval = 6.88-77.05, p < 0.001). Our study demonstrated an association between idiopathic BPPV and decreased serum vitamin D. Decreased serum vitamin D may be a risk factor of BPPV.
No preview · Article · Oct 2012 · Journal of Neurology
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to examine the mediational role of meaning in life on the relationship between optimism and subjective well-being in older adults. Two hundred and fifty community-dwelling subjects completed several instruments assessing the above constructs. Results from structural equation modeling indicated that optimism was positively associated with both meaning in life and subjective well-being. Furthermore, the relationship between optimism and wellbeing was partially mediated by meaning in life. Although numerous studies have found that optimism is a significant predictor of well-being, the current results indicate that it might not be a key predictor in elders. Our findings suggest that a focus on meaning in life may be a productive avenue to enhance subjective well-being in later life although stable internal resources such as optimism and pessimism impact their subjective well-being.
No preview · Article · Sep 2012 · Archives of gerontology and geriatrics
[Show abstract][Hide abstract] ABSTRACT: Cardiovascular risk factors are considered to also be risk factors for dementia. Recent studies have shown that the prevalence of cognitive dysfunction is high in patients with cardiac diseases. However, few studies have investigated the influence of cardiac function on cognition and brain structural changes in dementia. The aims of this study were to determine the relationship between cardiac and cognitive function, and to characterize any structural changes in the brain that could be caused by cardiac function in patients with dementia.
Dementia patients (n=93) were recruited prospectively with checking for the presence of vascular risk factors such as hypertension. Cognitive function was measured by the Mini-Mental State Examination, modified Mini-Mental State test, and Korean version of the Dementia Rating Scale. Brain magnetic resonance imaging was conducted to evaluate the cerebral white-matter changes (WMC), ventricular dilation, and cortical and hippocampal atrophy. Cardiac function was evaluated using two-dimensional echocardiography. We divided the patients into two groups according to the presence (+) or absence (-) of WMC.
In the entire cohort, the size of the left atrium (LA) was positively correlated with the degree of WMC, irrespective of age (p<0.05). The LA was larger in the WMC (+) group (n=42) than in the WMC (-) group. General cognitive function was significantly lower in the WMC (+) group than in the WMC (-) group. Subjects with an enlarged LA tended to exhibit lower cognitive function and more-severe cerebral WMC.
Cardiac dysfunction represented by LA enlargement could be related to cognitive decline and WMC of the brain resulting from impairment of the cerebral hemodynamic process in dementia.
Full-text · Article · Jun 2012 · Journal of Clinical Neurology
[Show abstract][Hide abstract] ABSTRACT: Carbapenem-resistance is rapidly evolving among the pathogenic microbes in intensive care units (ICUs). This study aimed to determine annual trend of carbapenem-resistance in the ICU for 4 years, since the opening of a university-affiliated hospital in South Korea.
From 2005 to 2008, microbial samples from consecutive 6,772 patients were screened in the ICU. Three hundred and ninety-seven patients (5.9%) and their first isolates of carbapenem-resistant pathogens were analyzed.
The percentage of patients infected with carbapenem-resistant organisms increased constantly during the initial three years (2.3% in 2005, 6.2% in 2006, 7.8% in 2007), then it declined to 6.5% in 2008. Acute Physiology and Chronic Health Evaluation (APACHE) III score at admission was 58.0±23.5, the median length of the ICU stay was 37 days, and the mortality rate was 37.5%. The sampling sites were endotracheal suction (67%), catheterized urine (17%), wound (6%) and others (10%). Bacteria with carbapenem-resistance were Pseudomonas aeruginosa (247 isolates, 62%), Acinetobacter baumannii (117 isolates, 30%), Enterobacteriaceae (12 isolates, 3%), and others (21, 5%). Of note, peak isolation of carbapenem-resistant microorganisms in medical ICU was followed by the same epidemic at surgical ICU.
Taken together, carbapenem-resistant pathogens are of growing concern in the ICU.