RESUMO
Heavy metals, such as Cd and Pb, are present in the particulate matter (PM) suspended in ambient air. Once internalized, they often accumulate in the human body and cannot be metabolized for long periods. Most previous studies on Cd and Pb metabolism used high concentrations of these heavy metals. In this study, we analysed the effects of low concentrations of Cd or Pb (similar to their concentrations in the PM) on the viability of lung epithelial cells and the secretion of pro-inflammatory factors, IL-6 and IL-8. A549 cells were cultured in the presence of Cd and Pb at 1 µg/L and 1 mg/L for 0, 4, 12, and 24 h and analysed using WST-8 and lactate dehydrogenase (LDH) assays and ELISA. Our results revealed that Cd and Pb induced comparable cytotoxicity and secretion of pro-inflammatory cytokines, IL-6 and IL-8, in a time-dependent manner, even at low concentrations. Altogether, our results suggest that heavy metals present in PM can cause chronic long-term effects on human lungs.
RESUMO
Candida spp. is an invasive infectious fungus, a major risk factor that can increase morbidity and mortality in hospitalized patients. In this study, 2,508 Candida spp. were isolated from various clinical specimens collected from university hospitals from July 2011 to October 2014. They were identified in order to determine isolation frequencies and characteristics by specimen, gender, age group, year, season, and month. The strain-specific isolation rate of Candida spp. is in the order of Candida albicans (1,218 strains, 48.56%), Candida glabrata (416 strains, 16.59%), Candida utilis (305 strains, 12.16%), Candida tropicalis (304 strains, 12.12%), and Candida parapsilosis (116 strains, 4.63%) and these five species accounted for more than 94% of the total strains. Of the specimens, Candida spp. were most frequently isolated from urine-catheter, followed by urine-voided, blood, sputum, other, open pus, vaginal discharge, Tip, ear discharge, bronchial aspiration and bile, in that order. Looking at the age distribution, the detection rate of patients in their 60s and older was significantly higher at 75.8% (1,900/2,508). The detection rate of patients in their 20s and younger was shown to be very low at 2.55% (64/2,508). By year, the detection rate of non-albicans Candida spp. showed a tendency to gradually increase each year compared with C. albicans. As isolation of Candida spp. from clinical samples at the specie level can vary depending on characteristics of the patient, sample, season, etc., continual studies are required.