Melatonin deficiency at tissue level: a possible aetiological factor in nasal polyposis.

Objective: The aim of this study was to examine whether melatonin is involved in the pathogenesis of nasal polyposis.

Method: This study included 29 patients with nasal polyposis and undergoing functional endoscopic sinus surgery. As a control group, 26 patients who had been operated on for a deviated nasal septum and concha bullosa were enrolled.

Evaluation of residual monomer release and toxicity of self-adhesive resin cements.

The aim of this study was to evaluate the amount of leached residual monomers from self-adhesive resin cements and evaluate their toxicity in-vitro. A total of 60 disk-shaped specimens (5 mm in diameter and 0.5 mm in thickness) were prepared from each cement (RelyX U200, SpeedCEM, G-Cem) (n=20).

Development and validation of a HPLC method for the determination of benzo(a)pyrene in human breast milk.

A simple analytical procedure was developed for the quantitation of benzo(a)pyrene in human breast milk using solid phase extraction (SPE) combined with high performance liquid chromatography. Before the chromatographic process, SPE, including C18 functional groups in silicagel cartridges, was conducted for sample preparation. A C18 column (100×4.

Current HPLC Methods for Assay of Nano Drug Delivery Systems.

In nano drug formulations the mechanism of release is a critical process to recognize controlled and targeted drug delivery systems. In order to gain high bioavailability and specificity from the drug to reach its therapeutic goal, the active substance must be loaded into the nanoparticles efficiently. Therefore, the amount in biological fluids or tissues and the remaining amount in nano carriers are very important parameters to understand the potential of the nano drug delivery systems.

Spectrofluorimetric determination of tobramycin in human serum and pharmaceutical preparations by derivatization with fluorescamine.

A simple, sensitive and selective spectrofluorimetric method has been developed for the determination of tobramycin (TOB) in human serum and pharmaceutical preparations. The method is based on the reaction between the primary amino group of TOB and fluorescamine in borate buffer, pH 8.5, to give a highly fluorescent derivative which is measured at 469 nm after excitation at 388 nm.