Biological responses according to the shape and size of carbon nanotubes in BEAS-2B and MESO-1 cells

This study aimed to investigate the influence of the shape and size of multi-walled carbon nanotubes (MWCNTs) and cup-stacked carbon nanotubes (CSCNTs) on biological responses in vitro. Three types of MWCNTs - VGCF (R)-X, VGCF (R)-S, and VGCF (R) (vapor grown carbon fibers; with diameters of 15, 80, and 150 nm, respectively) - and three CSCNTs of different lengths (CS-L, 20-80 mu m; CS-S, 0.5-20 mu m; and CS-M, of intermediate length) were tested. Human bronchial epithelial (BEAS-2B) and malignant pleural mesothelioma cells were exposed to the CNTs (1-50 mu g/mL), and cell viability, permeability, uptake, total reactive oxygen species/superoxide production, and intracellular acidity were measured. CSCNTs were less toxic than MWCNTs in both cell types over a 24-hour exposure period. The cytotoxicity of endocytosed MWCNTs varied according to cell type/size, while that of CSCNTs depended on tube length irrespective of cell type. CNT diameter and length influenced cell aggregation and injury extent. Intracellular acidity increased independently of lysosomal activity along with the number of vacuoles in BEAS-2B cells exposed for 24 hours to either CNT (concentration, 10 mu g/mL). However, total reactive oxygen species/superoxide generation did not contribute to cytotoxicity. The results demonstrate that CSCNTs could be suitable for biological applications and that CNT shape and size can have differential effects depending on cell type, which can be exploited in the development of highly specialized, biocompatible CNTs.ArticleINTERNATIONAL JOURNAL OF NANOMEDICINE. 9:1979-1990 (2014)journal articl

Culture medium type affects endocytosis of multi-walled carbon nanotubes in BEAS-2B cells and subsequent biological response

AbstractWe examined the cytotoxicity of multi-walled carbon nanotubes (MWCNTs) and the resulting cytokine secretion in BEAS-2B cells or normal human bronchial epithelial cells (HBEpCs) in two types of culture media (Ham’s F12 containing 10% FBS [Ham’s F12] and serum-free growth medium [SFGM]). Cellular uptake of MWCNT was observed by fluorescent microscopy and analyzed using flow cytometry. Moreover, we evaluated whether MWCNT uptake was suppressed by 2 types of endocytosis inhibitors. We found that BEAS-2B cells cultured in Ham’s F12 and HBEpCs cultured in SFGM showed similar biological responses, but BEAS-2B cells cultured in SFGM did not internalize MWCNTs, and the 50% inhibitory concentration value, i.e., the cytotoxicity, was increased by more than 10-fold. MWCNT uptake was suppressed by a clathrin-mediated endocytosis inhibitor and a caveolae-mediated endocytosis inhibitor in BEAS-2B cells cultured in Ham’s F12 and HBEpCs cultured in SFGM. In conclusion, we suggest that BEAS-2B cells cultured in a medium containing serum should be used for the safety evaluation of nanomaterials as a model of normal human bronchial epithelial cells. However, the culture medium composition may affect the proteins that are expressed on the cytoplasmic membrane, which may influence the biological response to MWCNTs

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Effectiveness of health education programme of primary school-aged children in the urban area of China

Objective: To evaluate the effectiveness of a health education programme for school-aged children’s social anxiety, interpersonal closeness and perspective- taking (PT) ability in an urban area of eastern China. Methods: This study was a non‐randomized controlled trial. A total of 257 school-aged children in fourth to sixth grades from a primary school were recruited, aged between 9 and 12 years. They were assigned by their classes in each grade to the intervention (N = 128) and control (N = 129) groups and completed anonymous self-reported questionnaires. Data were collected before and after interventions. Changes in children’s social anxiety, interpersonal closeness, and social cognition and behaviors were measured using different assessment scales. Results: Overall, 122 interventions and 128 controls participated in the trial. Significant differences for the intervention group were found between before and after interventions in the scores of social anxiety, interpersonal closeness, and PT ability (all p < 0.05), while the scores for the control group were roughly unchanged. Conclusion: This health education programme was effective for decreasing the Chinese schoolaged children’s social anxiety, improving their interpersonal closeness, as well as increasing their PT ability

Correction: Effectiveness of health education programme of primary school-aged children in the urban area of China

Objective: To evaluate the effectiveness of a health education programme for school-aged children’s social anxiety, interpersonal closeness and perspective- taking (PT) ability in an urban area of eastern China. Methods: This study was a non‐randomized controlled trial. A total of 257 school-aged children in fourth to sixth grades from a primary school were recruited, aged between 9 and 12 years. They were assigned by their classes in each grade to the intervention (N = 128) and control (N = 129) groups and completed anonymous self-reported questionnaires. Data were collected before and after interventions. Changes in children’s social anxiety, interpersonal closeness, and social cognition and behaviors were measured using different assessment scales. Results: Overall, 122 interventions and 128 controls participated in the trial. Significant differences for the intervention group were found between before and after interventions in the scores of social anxiety, interpersonal closeness, and PT ability (all p < 0.05), while the scores for the control group were roughly unchanged. Conclusion: This health education programme was effective for decreasing the Chinese schoolaged children’s social anxiety, improving their interpersonal closeness, as well as increasing their PT ability