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1.  Carbon Black Particle Exhibits Size Dependent Toxicity in Human Monocytes 
Increased levels of particulate air pollution are associated with increased respiratory and cardiovascular mortality and morbidity. Some epidemiologic and toxicological researches suggest ultrafine particles (<100 nm) to be more harmful per unit mass than larger particles. In the present study, the effect of particle size (nano and micro) of carbon black (CB) particle on viability, phagocytosis, cytokine induction, and DNA damage in human monocytes, THP-1 cells, was analysed. The cells were incubated with nanosize (~50 nm) and micron (~500 nm) size of CB particles in a concentration range of 50–800 µg/mL. The parameters like MTT assay, phagocytosis assay, ELISA, gene expression, and DNA analysis were studied. Exposure to nano- and micron-sized CB particles showed size- and concentration dependent decrease in cell viability and significant increase in proinflammatory cytokines IL-1β, TNF-α and IL-6 as well as chemokine IL-8 release. Gene expression study showed upregulation of monocyte chemoattractant protein-1 gene while cyclooxygenase-2 gene remained unaffected. Nano CB particles altered the phagocytic capacity of monocytes although micron CB had no significant effect. CB particles did not show any significant effect on DNA of monocytes. The investigations indicate that CB particles in nanosize exhibit higher propensity of inducing cytotoxicity, inflammation, and altered phagocytosis in human monocytes than their micron size.
PMCID: PMC3941121  PMID: 24669321
2.  Nanosized Zinc Oxide Induces Toxicity in Human Lung Cells 
ISRN Toxicology  2013;2013:316075.
Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. With the wide application of ZnO-NPs, concern has been raised about its unintentional health and environmental impacts. This study investigates the toxic effects of ZnO-NPs in human lung cells. In order to assess toxicity, human lung epithelial cells (L-132) were exposed to dispersion of 50 nm ZnO-NPs at concentrations of 5, 25, 50, and 100 μg/mL for 24 h. The toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, DNA damage analysis, and gene expression. Exposure to 50 nm ZnO-NPs at concentrations between 5 and 100 μg/mL decreased cell viability in a concentration-dependent manner. Morphological examination revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The oxidative stress parameters revealed significant depletion of GSH level and increase in ROS levels suggesting generation of oxidative stress. ZnO-NPs exposure caused DNA fragmentation demonstrating apoptotic type of cell death. ZnO-NPs increased the expression of metallothionein gene, which is considered as a biomarker in metal-induced toxicity. To summarize, ZnO-NPs cause toxicity in human lung cells possibly through oxidative stress-induced apoptosis.
PMCID: PMC3749605  PMID: 23997968
3.  Effectiveness of physical activity promotion in blood pressure and blood sugar reduction: A community–based intervention study in rural south India 
Physical activity of moderate intensity for 30 minutes a day, on most days substantially reduces the risk of many chronic diseases.
To assess the effect of regular physical activity on blood pressure and blood sugar levels in a rural Indian community
Settings and Design:
This community-based study was carried out in Periakattupalayam and Rangareddipalayam in south India, with 485 subjects, aged 20 to 49 years.
Materials and Methods:
The study was done in five phases: Awareness campaign, baseline assessment of participants, intervention phase (10 weeks), interim, and final assessment. Physical activity of moderate intensity (brisk walking for 30 minutes on four days / week) was promoted by forming 30 small walking groups, in a home-based setting, with professional supervision. Village leaders and Self-Help Group members were the resource people for the promotion of physical activity.
Statistical Analysis:
Analysis was done by using paired ‘t’ test; the ‘Intention-to-Treat’ approach was utilized for the interpretation of the findings of the study.
Of the 485 subjects, 265 (54.6%) complied with walking on more than four days / week, while 156 (32.2%) walked on one to four days / week, and 64 (13.2%) dropped out during the intervention period. This study has shown that a 10-week intervention to promote physical activity was effective in significantly decreasing the population's BP by 1.56 / 0.74 mm Hg, fasting blood sugar levels by 2.82 mg%, body weight by 0.17 kg, and BMI by 0.06 kg / m2.
This study has proved the functional feasibility of enabling people to undertake physical activity in a rural Indian community, and the effectiveness of using physical activity, to significantly reduce the population's mean BP and blood sugar levels.
PMCID: PMC3410184  PMID: 22870410
Blood pressure; chronic diseases; community intervention; physical activity

Results 1-3 (3)