Dual labeled Ag@SiO2 core-shell nanoparticle based optical immunosensor for sensitive detection of E. coli.

An optical nanobiosensor is presented using a fluorescent dye and anti-E. coli McAb anchored Ag@Silica core shell nanoparticles, for rapid and sensitive Escherichia coli detection in environmental samples. The synthesized dual labeled core shell (DLCS) nanoparticle shows intense fluorescence at 620 nm in solution, having a narrow emission with full width at half maxima (FWHM) of 10 nm, as a prerequisite to develop a sensitive detection platform for various biosensing applications. The specific E. coli was captured using an anti-E. coli antibody functionalized quartz glass, followed by a treatment with DLCS, where the photoluminescence spectroscopy was used to detect the target pathogen. The fabrication of the quartz glass based optical-immunosensor was monitored, and the results show changes in the photoluminescent patterns, which substantiate that varied species were immobilized on the surface of the antibody modified quartz glass. Consequently, the optical immunosensor demonstrated specificity and improved sensitivity, as compared to the customary methods, and was able to detect as low as 5CFU/mL. The developed DLCS based optical immunosensor was evaluated with environmental water samples, which showed acceptable precision, reproducibility and stability, and could be readily applied to the routine monitoring of pathogenic microorganisms in the environmental samples, and most importantly, demonstrate the potential of a prototype development of a simple and inexpensive diagnostic technique.

Expression of TNF-α and RANTES in drug-induced human gingival overgrowth.

OBJECTIVES: Regulated on activation, normal T cell expressed and secreted (RANTES) is a chemokine that is produced by fibroblasts, lymphoid and epithelial cells of the mucosa in response to various external stimuli. RANTES expression has been demonstrated in a variety of diseases characterized by inflammation, including asthma, transplantationassociated accelerated atherosclerosis, endometriosis and fibrosis. RANTES mRNA is quickly up-regulated by tumor necrosis factor (TNF)-α stimulation. Cyclosporine A (CsA) is widely used in organ transplant patients, often causing various side-effects including gingival overgrowth, which is fibrotic in nature. This study was carried out to assess the mRNA expression of TNF-α and RANTES in healthy individual, chronic periodontitis and CsAinduced gingival overgrowth tissues. MATERIALS AND METHODS: Gingival tissue samples were collected from chronic periodontitis, CsAinduced gingival overgrowth patients and healthy individuals. Total RNA was isolated and reverse transcription polymerase chain reaction (RT-PCR) was performed for TNF-α and RANTES expression. RESULTS: The results suggest that CsAinduced gingival overgrowth tissues expressed significantly increased TNF-α and RANTES compared to control and chronic periodontitis. CONCLUSION: The findings of the present study suggest that CsA can modify the expression of TNF-α and RANTES in drug-induced human gingival overgrowth.

Expression of insulin like growth factor binding protein-5 in drug induced human gingival overgrowth.

BACKGROUND & OBJECTIVE: Insulin like growth factor binding proteins (IGFBPs) control the distribution, function and activity of insulin like growth factors (IGFs) in various cells, tissues and body fluids, thereby modulating their metabolic and mitogenic effects. IGFBP-5, the most conserved IGFBP, can function through IGF or directly play a role in fibrosis. Cyclosporine A (CsA) widely used in organ transplant patients, often causes various side effects including gingival fibrotic overgrowth. This study was carried out to assess the mRNA expression of IGFBP-5 in healthy human gingival, chronic periodontitis and CsA induced gingival overgrowth tissues. METHODS: Total RNA was isolated from gingival tissues collected from eight patients with chronic periodontitis, eight patients with CsA induced gingival outgrowth and an equal number of healthy individuals, and subjected to reverse transcription (RT)-PCR for IGFBP-5 gene expression. RESULTS: CsA induced gingival overgrowth tissues expressed increased IGFBP-5 mRNA compared to control and chronic periodontitis. INTERPRETATION & CONCLUSION: Increased mRNA expression of IGFBP-5 in CsA induced gingival outgrowth tissues may be associated with increased collagen synthesis, thereby promoting fibrogenesis.