Possible prognostic significance of p53 and Ki 67 in inverted sinonasal papilloma

The aim of this study is to test the possible prognostic significance of p53 and Ki67 expression in inverted papilloma of the lateral nasal wall and adjacent sinuses regarding their malignant potential and recurrence. 49 biopsies of the lateral nasal wall and adjacent sinuses obtained from 41 patients from three hospitals were investigated. Immunohistochemically demonstrated p53 and Ki67 expression was measured and statistically evaluated. p53 immunoreactivity was demonstrated in most of papillomas with carcinomas but only in two benign papillomas, while Ki67 demonstrated stronger immunoreactivity in carcinomas and surrounding epithelium. Immunohistochemical staining of inverted sinonasal papillomas for p53 and Ki67 can give useful information concerning the existence of synchronous carcinoma and, in case of high Ki67, a hint toward possible recurrence.     

Study of Plasma Induced Chemistry by DC Discharges in CO<Subscript>2</Subscript>/N<Subscript>2</Subscript>/H<Subscript>2</Subscript>O Mixtures Above a Water Surface

The chemistry induced by atmospheric pressure DC discharges above a water surface in CO(2)/N(2)/H(2)O mixtures was investigated. The gaseous mixtures studied represent a model prebiotic atmosphere of the Earth. The most remarkable changes in the chemical composition of the treated gas were the decomposition of CO(2) and the production of CO. The concentration of CO increased logarithmically with the increasing input energy density and an increasing initial concentration of CO(2) in the gas. The highest achieved concentration of CO was 4.0 +/- 0.6 vol. %. The production of CO was crucial for the synthesis of organic species, since reactions of CO with some reactive species generated in the plasma, e. g. H* or N* radicals, were probably the starting point in this synthesis. The presence of organic species (including the tentative identification of some amino acids) was demonstrated by the analysis of solid and liquid samples by high-performance liquid chromatography, infrared absorption spectroscopy and proton-transfer-reaction mass spectrometry. Formation of organic species in a completely inorganic CO(2)/N(2)/H(2)O atmosphere is a significant finding for the theory of the origins of life.     

Nitrogen regulation of fatty acids and avermectins biosynthesis in Streptomyces avermitilis

Fatty acid composition was analysed in the producer of avermectins, Streptomyces avermitilis C-18 grown in chemically defined medium with different nitrogen sources. Significant differences in nitrogen regulation of fatty acid biosynthesis were found in this strain in comparison with other streptomycetes studied so far. This finding could be explained at the level of regulation of branched-chain amino acid metabolism.