A competitive chemiluminescent immunoassay for quantitation of muramyl tripeptide phosphatidyl-ethanolamine (MTP-PE) in plasma has been developed. The assay is based on the use of an acridinium ester-labelled analogue of muramyl tripeptide and a rabbit antiserum. It includes an overnight incubation and a separation with a second antibody covalently coupled to paramagnetic particles. The sensitivity of detection is 0.012 nmol/l, the assay working range is 0.1-5 nmol/l, and the inter-assay CVs are less than or equal to 10%. Using up to 6000-fold sample dilutions, a wide working range (0.1-30,000 nmol/l) is obtained. Rat plasma samples were collected during and one day after intravenous infusion of MTP-PE. Following infusion, the concentrations in plasma declined multiphasically. Half-life time was 0.37 h +/- 0.03 (mean +/- SD, alpha phase) and 1.76 h +/- 0.08 (mean +/- SD, beta phase), clearance and volume of distribution were 0.09 +/- 0.02 l/h x kg (mean +/- SD) and 0.06 +/- 0.01 l/kg (mean +/- SD) respectively. The use of an acridinium ester as a chemiluminescent (CL) label overcomes the problems associated with reagents of limited shelf-life.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMedDate not supplied

Increased occurrence of depression in psychosis-prone subjects: a follow-up study in primary care settings.

A follow-up survey was performed with a network of general practitioners (GPs) to examine whether a higher proneness for psychosis predicts a greater incidence of depression in subjects with no history of mood disorder. At the first stage of the survey (T1), a self-report questionnaire exploring delusional ideation (Peters et al. Delusional Inventory [PDI-21]) was administered to the patients of the GPs. Information on psychiatric status at the baseline and conclusion of the 12-month follow-up period was provided by the GPs. The present study was restricted to 425 subjects with no lifetime history of depression. An incident depression was diagnosed in 18 subjects. Most items exploring delusional beliefs and hallucinations were more frequently endorsed by subjects with incident depression. Subjects with a PDI-21 score above the 90th percentile at T1 were nine times more likely to present with an incident depression during the follow-up period than those with PDI-21 scores below the 10th percentile. Psychosis proneness is associated with a greater risk for depression, suggesting that a continuum of vulnerability may exist between affective disorder and nonaffective psychosis.

Adult↗