Patterned monolayers of nitronyl nitroxide radicals

We report here the results of the preliminary characterization of the monolayer obtained both by self-assembling and microcontact printing of a di-alkyl sulfide nitronyl nitroxide derivative, 11-decyl sulfanyl-undecanyl nitronyl nitroxide of which we describe the synthesis. The sulfide unit has been introduced in order to allow the grafting of the molecule to the gold surface as well as to improve the stability of the organic radical with respect to different grafting agents like thiols, whereas the two long alkyl chains have been introduced to enhance the packing order of the molecules in a self assembled monolayer structure.X-band ESR was used to demonstrate the persistence of the paramagnetic character of the radical in the self-assembled monolayers, and to study its relatively large mobility. The microcontact printed monolayer was characterized by AFM, suggesting a non-negligible mobility of the molecules on the surfaces and a strong tilting of the molecules on the surface.     

Comparison of the conventional cervical smear and liquid-based cytology: results of a controlled, prospective study in the Abruzzo Region of Italy

OBJECTIVE: To compare conventional cervical testing (CCT) and liquid-based cytology (LBC) within a randomized trial performed during 2001-2002 in the Abruzzo Region of Italy, including a cost-outcome comparative analysis. STUDY DESIGN: Study subjects were recruited in the framework of a controlled, randomized study organized in the Abruzzo Region. Women aged 2 6-64 years were randomized to an active arm (LBC) or control arm (CC1). The particip ating laboratories had no previous ex perience with LBC. RESULTS: The inadequacy rate was 4.3% in CCT and 1.3% in the LBC arm (D < 0.001). Atypical squamous cells of undetermined sign ifi cance and atypical glands of undetermined significance reports were more frequent at CCT vs. LBC. A small, insignificant excess of low grade squamous intraepithelial lesions or high grade squamous epithelial lesions+ reports was observed in the LBC arm. The cervical intraepithelial neoplasia 2+ (CIN2+) detection rate was not statistically different in the 2 arms (CCT=0.54%, LBC= 0.66%, p = 0.28). In the overall series positive predictive value was slightly but not significantly higher in the LBC arm. LBC increased costs by 4.2% per both screened women and CIN2+ detected. CONCLUSION: The study reflects the introductory phase of LBC in laboratories without prior LBC experience. In this setting LBC reduced the inadequacy rate and decreased reading and was at least as sensitive as and more specific than CCT. Utilization of LBC in organized screening programs will be based on local feasibility, considering that the high cost of LBC is only partially compensated for by other benefits, such as residual cellular material, available for molecular testing, including human papillomavirus testing.     

Structural requirements for the enzymatic phosphorylation of phosvitin.

Some structural features required for the enzymatic phosphorylation of phosvitin by purified rat liver cytosol phosvitin kinase have been investigated by testing the activity of such an enzyme toward phosphopeptides differing in size and chemical composition, obtained by pronase or acid hydrolysis of phosvitin. The results obtained can be summarized as follows: (a) Phosvitin kinase phosphorylates even fairly simple phosphopeptides (mol.wt 1000-2000) at rates comparable with intact phosvitin. (b) Acetylation of both phosvitin and pronase phosphopeptides completely prevents their phosphorylation indicating that some lysine residues are strictly required for the phosvitin kinase reaction. (c) Accordingly polyphosphorylserine blocks Ser(P)n which are very actively phosphorylated in phosvitin and pronase phosphopeptides, do not undergo any more enzymatic phosphorylation once isolated as such in a form free of other amino acids. (d) The activity of phosvitin kinase toward substrates probably devoid of Ser(P)n blocks suggests that there are not required for the protein kinase reaction. However, they apparently enhance the phosphorylation rate of the peptide substrates, likely by making easier their binding to the enzyme. It is proposed therefore that the peptidic unit able to undergo phosphorylation by rat liver cytosol phosvitin kinase consists of one or more phosphorylserine residues having in their close proximity a lysine residue playing a critical role in the mechanism of transphosphorylation.     

Bone marrow cell chromosomal aberrations and styrene biotransformation in mice given styrene on a repeated oral schedule

Styrene's capacity to induce chromosomal aberrations was studied in bone marrow cells of CD1 male mice. No mutagenic effect could be detected after either a 4-day treatment course with daily oral doses of 500 mg/kg or a 70-day course with daily oral doses of 200 mg/kg. Urinary elimination of styrene metabolites related to styrene-7,8-oxide formation (i.e. phenylethylene glycol, mandelic acid, benzoic acid, phenylglyoxylic acid and total mercapturic acids) was quantitatively evaluated in the group of mice given the 200 mg/kg dose. In parallel, kinetic studies were made on styrene and styrene-7,8-oxide blood concentrations in the same group of animals. These determinations were carried out on days 1 and 70 of treatment by spectrophotometric, gas chromatographic and mass fragmentographic procedures.Not even nanograms of styrene-7,8-oxide were found in the blood of styrene-treated mice. This suggests that the metabolite does not migrate from the cellular compartment where it is formed being immediately metabolized or irreversibly bound to cellular structures.This observation could well explain the lack of mutagenic effects observed.     

Inhibition of protein kinase CK2 by condensed polyphenolic derivatives. An in vitro and in vivo study

ATP site-directed inhibitors that can target individual kinases are powerful tools for use in signal transduction research, all the more so in the case of a pleiotropic, constitutively active protein kinase such as CK2, which is not turned on in response to specific stimuli. By screening a library of more than 200 derivatives of natural polyphenolic compounds, we have identified 16 molecules which inhibit CK2 with IC(50) values of 相似文献