Label-free, ITO-based immunosensor for the detection of a cancer biomarker: Receptor for Activated C Kinase 1.

A new, quite sensitive disposable immunosensor, based on the anti-RACK1 antibody, was developed for the determination of Receptor for Activated C Kinase 1 (RACK1) for the first time. Moreover, indium tin oxide (ITO) flexible sheets were modified by using aldehyde ended silane 11-(triethoxysilyl)undecanal (TESU) self-assembled monolayers (SAMs) for immobilizing the anti-RACK1 antibody via covalent bonds. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) methods were used for characterizing the immobilization steps and for determining the RACK1 concentration. To obtain a successful immunosensor, experimental factors were optimized. This quite sensitive biosensor was able to detect concentrations as low as fg mL(-1). The detection principle was based on the change in charge transfer resistance and the Nyquist plot diameter and these changes were monitored by using electrochemical impedance spectroscopy (EIS). This impedimetric immunosensor had perfect repeatability and reproducibility. We proved that the new silane agent, TESU, performs well in biosensor applications. The feasibility of the fabricated immunosensor was tested by detecting RACK1 in artificial and real human serum samples.

Virtual bronchoscopy as a dynamic modality in the diagnosis and treatment of suspected foreign body aspiration.

AIM: Rigid bronchoscopy (RB) is an invasive procedure and has its own risks. The place of virtual bronchoscopy (VB) in the treatment of patients with a clinical and radiological suspicion of foreign body aspiration was evaluated to see whether its usage can prevent rigid bronchoscopy. PATIENTS AND METHODS: The study was performed between December 2005 and May 2007 in 60 patients (35 M and 25 F) aged between 4 months and 7 years with clinical and radiographical suspicion of foreign body aspiration. Patients with radio-opaque foreign body aspiration were excluded from the study and treated directly by RB. VB was performed using 16 detector multislice computerized tomography (MDCT). If VB or clinical follow-up supported the diagnosis of foreign body, RB was performed for diagnosis and treatment. The results of RB were compared with the results of VB. RESULTS: All patients underwent VB. In 40 patients there was a suspicion of foreign body with VB. Two patients improved without RB: one had spontaneous discharge of the foreign body with coughing, and one experienced spontaneous clinical improvement. The remaining 38 patients underwent RB and a foreign body was found in the reported localization in 33. No foreign body was found with RB in 5 patients showing foreign body in VB. But we found bronchial vegetations in 2, obstructing mucus plug in 2 and external bronchial compression by neuroenteric cyst in one. In 20 patients there was no suspicion of foreign body with VB. Of these, 7 patients with presenting symptoms for more than one month underwent RB, but no foreign body was found. The 13 remaining patients were followed up clinically with improvement of symptoms. CONCLUSION: MDCT devices still require further investigation when used in pediatric surgical pathologies. Reconstructed images of VB can reveal images close to the real anatomy. In patients with a suspicion of foreign body ingestion, initial VB may help to determine the presence and exact localization of the foreign body and if negative, may reduce the number of unnecessary rigid bronchoscopies. None of the patients with negative VB had foreign bodies. Positive VB may help to shorten the operative time by providing information about the localization and size of the foreign body.