An alternative infrared spectroscopy assay for the quantification of polysaccharides in bacterial samples.

The ability of bacteria to produce extracellular polysaccharides has been regarded as an indication of biofilm-forming capacity. Therefore, the determination of the sugar content in bacterial samples becomes a significant parameter. The colorimetric methods currently used are rather sensitive to the nature of the sugars and therefore require knowledge of the sugar types present in the samples.

Combined Fourier transform infrared and Raman spectroscopic approach for identification of multidrug resistance phenotype in cancer cell lines.

Cancer cells escape cytotoxic effects of anticancer drugs by a process known as multidrug resistance (MDR). Identification of cell status by less time-consuming methods can be extremely useful in patient management and treatment. This study aims at evaluating the potentials of vibrational spectroscopic methods to perform cell typing and to differentiate between sensitive and resistant human cancer cell lines, in particular those that exhibit the MDR phenotype.

Impact of carbamylation on type I collagen conformational structure and its ability to activate human polymorphonuclear neutrophils.

Carbamylation by urea-derived cyanate is a posttranslational modification of proteins increasing during chronic renal insufficiency, which alters structural and functional properties of proteins and modifies their interactions with cells. We report here the major structural alterations of type I collagen induced by carbamylation. Biophysical methods revealed that carbamylated collagen retained its triple-helical structure, but that slight changes destabilized some regions within the triple helix and decreased its ability to polymerize into normal fibrils.

Study of tumor cell invasion by Fourier transform infrared microspectroscopy.

Lung cancer is usually fatal once it becomes metastatic. However, in order to develop metastases, a tumor usually invades the basal membrane and enters the vascular or lymphatic system. In this study, a three-dimensional artificial membrane using collagen type I, one of the main components of basal membranes, was established in order to investigate tumor cell invasion.

Reversal of multidrug resistance-associated protein-mediated daunorubicin resistance by camptothecin.

The multidrug-resistance (MR) status of camptothecin (CPT) was investigated in colon adenocarcinoma HT29 cells, leukemia K562, and breast carcinoma MCF7 cells expressing P-glycoprotein (Pgp) and/or MR-associated protein (MRP1). The concentration that induced 50% growth inhibition (IC(50)) against CPT was 0.14 and 0.