Cytotoxicity and stress gene microarray analysis in cadmium-exposed CRL-1439 normal rat liver cells.

Cadmium is a biologically non-essential divalent hazardous metal. Previous studies demonstrated that cadmium toxic effect was caused by reactive oxygen species. Since gene expression is influenced by the presence of these reactive oxygen species, the association between metal intoxication and gene expression has recently become a major focus of research.

Comparative evaluation of cytotoxicity of cadmium in rat liver cells cultured in serum-containing medium and commercially available serum-free medium.

Cadmium (Cd) is an industrial pollutant and carcinogenic metal. Most in vitro Cd toxicity studies have been carried out in various cell lines cultured in 10% fetal bovine serum (FBS) containing medium. In this report, we compared the toxic effect of Cd (0-300 microM) on cell growth, total RNA, total proteins, and antioxidant enzymes in rat normal liver cells cultured in medium with 10% FBS or commercially available serum-free medium for 4 or 8 hours.

Role of pneumococcal surface protein C in nasopharyngeal carriage and pneumonia and its ability to elicit protection against carriage of Streptococcus pneumoniae.

Previous studies suggested that PspC is important in adherence and colonization within the nasopharynx. In this study, we conducted mutational studies to further identify the role PspC plays in the pathogenesis of pneumococci. pspC and/or pspA was insertionally inactivated in a serotype 2 Streptococcus pneumoniae strain and in a serotype 19 S.

PspC, a pneumococcal surface protein, binds human factor H.

PspC was found to bind human complement factor H (FH) by Western blot analysis of D39 (pspC(+)) and an isogenic mutant TRE108 (pspC). We confirmed that PspA does not bind FH, while purified PspC binds FH very strongly. The binding of FH to exponentially growing pneumococci varied among different isolates when analyzed by fluorescence activated cell sorting analysis.

Characterization of binding of human lactoferrin to pneumococcal surface protein A.

Human lactoferrin is an iron-binding glycoprotein that is particularly prominent in exocrine secretions and leukocytes and is also found in serum, especially during inflammation. It is able to sequester iron from microbes and has immunomodulatory functions, including inhibition of both complement activation and cytokine production. This study used mutants lacking pneumococcal surface protein A (PspA) and PspC to demonstrate that the binding of human lactoferrin to the surface of Streptococcus pneumoniae was entirely dependent on PspA.