Having limitations such as lacking of parity information which may affect the magnitude of risk estimates, this study demonstrates that ovarian endometriosis has a 4-fold increased risk of OC. Adenomyosis may associate with a 4- to 5-fold increased risk of OC and EC, and unexpectedly, a 13-fold increased risk of CRC.

We report a detection method for C-reactive protein (CRP) based on competitive immunoassay using magnetic nanoparticles under magnetic fields. Functional magnetic nanoparticles were prepared and conjugated with anti-CRP for immunoassay. Magnetic nanoparticles labeled with anti-CRP were flowed through a separation channel to form depositions for selective capture of CRP under magnetic fields. Free CRP and a fixed number of CRP-labeled particles were used to compete for a limited number of anti-CRP binding sites on the magnetic nanoparticles. The deposited percentages of CRP-labeled particles at various concentrations of free CRP were determined and used as a reference plot. The determination of CRP in the unknown sample was deduced from the reference plot using the deposited percentages. The running time was less than 10 min. The CRP concentration of serum sample was linearly over the range of 1.2-310 microg/mL for deposited percentages of CRP-labeled particles. The detection limit of this method was 0.12 microg/mL which was approximately 8-fold lower than the typical clinical cutoff concentration (1 microug/mL). This method can provide a fast, simple, and sensitive way for protein detection based on competitive immunoassay using magnetic nanoparticles under magnetic fields.

The bluret reaction makes peptides electrochemically active. This is the basis of an electrochemical method for the detection of peptides following their liquid chromatographic separation. This paper discusses the influence of tyrosine, an electroactive amino acid, on the detection of Cu(II)-peptide (bluret) complexes containing it. The dual electrode detector has an upstream anode and a downstream cathode. Tyrosine-containing peptides yield anodic signals that are approximately the sum of the tyrosine signal and the signal from the bluret complex of a nonelectroactive model peptide, phenylalanylglycyl-glycine (FGG). The cathodic signal is depressed in comparison to FGG. This is traced to the presence of an intramolecular reaction between Cu(III) and a reaction product resulting from the oxidation of the tyrosinyl residue. The rate constant for the corresponding intermolecular reaction is significant (10(6)-10(7) M-1 s-1), but in practical analytical situations, the concentrations of the reactants will be small, so the reaction will not be a major factor. Sensitivities for several bioactive peptides are reported. The dependence of the signals on the position of tyrosine in a tripeptide is also studied.

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