Mindfulness-based relapse prevention for cannabis regular users: Preliminary outcomes of a randomized clinical trial.

Mindfulness-based approaches have shown their effectiveness in caring for patients with substance use disorders (SUD). Mindfulness-based relapse prevention (MBRP) integrates practices from mindfulness-based interventions and cognitive-behavioral relapse prevention (RP) approaches. This article presents the preliminary results of a study that measures the effectiveness of an MBRP protocol for volunteer cannabis users willing to reduce or stop their consumptions. Twenty cannabis users were randomly assigned to either receive an eight-week outpatient MBRP program or treatment as usual (TAU). Cannabis use was assessed weekly through the timeline follow back (TLFB). Eighty percent of individuals received MBRP treatment and 60% of individuals received TAU completed treatment. Preliminary results did not find significant difference at the end of treatment (week 8) regarding the number of joints smoked. Despite the absence of any significant difference between the two groups, the contribution of mindfulness in the caring of SUD seems encouraging and promising. Many MBRP group participants reported qualitative changes in the way they consumed. This study will be continued in order to evaluate the effectiveness of MBRP on a larger number of subjects.

Indirect double sandwich ELISA for the specific and quantitative measurement of mouse IgM, IgA and IgG subclasses.

We have developed sensitive enzyme-linked immunosorbent assays (ELISA) which measure mouse serum heavy chain immunoglobulin isotypes in nanograms per milliliter. In each case the specific isotypic Ig is sandwiched between an isotype-specific antibody used for coating and another isotype-specific antibody coupled to biotin for detection (with alkaline phosphatase coupled to avidin). These methods are simple to perform, specific for each isotype, reproducible with an average coefficient of variation of 5% for IgG1, 3% for IgG2a, 7% for IgG2b, 10% for IgG3, 3% for IgA and 7% for IgM, and at least 100 times more sensitive than radial immunodiffusion. The assays have been used to determine the absolute concentrations of mouse serum heavy chain Ig isotypes.

An indirect asymmetrical sandwich ELISA using anti-allotype antibodies for the specific and quantitative measurement of mouse IgG2a of Igh-1b allotype.

We recently described an indirect double sandwich ELISA (Klein-Schneegans et al., J. Immunol. Methods (1989) 119, 117) which permits the specific and quantitative measurement of mouse IgM, IgA and IgG subclasses with one major exception: IgG2a of the b allotype (Igh-1b in mouse strains such as C57BL/6) could not be reliably quantitated even by a very specific and sensitive asymmetrical sandwich ELISA (using two different anti-IgG2a isotype antibodies for capture and for detection). We now describe a similar method based on the use of two different anti-IgG2a allotype antibodies for the capture and detection of IgG2a in the serum of Igh-1b mouse strains.

Serum concentrations of IgM, IgG1, IgG2b, IgG3 and IgA in C57BL/6 mice and their congenics at the nu(nude)locus.

The absolute concentrations of IgM, IgG1, IgG2b, IgG3 and IgA were determined in mice of C57BL/6 background, from weaning to one year of age, by quantitative isotype-specific, indirect double sandwich ELISAs. The comparison of 10-40 weeks-old athymic nude C57BL/6 females with age matched females of the wild strain showed a general decrease of the whole serum Ig levels in the athymic mice, which was however contributed quite differently by the different Ig isotypes: a significant decrease (about 3.5 fold) was found for IgG2b only (0.34 mg/ml), whereas 1.5 fold more IgM (0.28 mg/ml) and about 2 fold more IgG3 (0.27 mg/ml) were detected, the IgG1 (0.19 mg/ml) and IgA (0.07 mg/ml) levels remaining within the normal range ! Limited data for IgG2a suggest that that this isotype may also be decreased in nude mice (0.36 mg/ml) in comparison with normal B6 + mice (0.54 mg/ml). Thus, although homozygosity at the nu locus results in a lack of effector T cells, our data show, at the humoral level, a limited degree of thymus dependence of an Ig isotype. It is intriguing that, although thymus dependence of several Ig isotypes looked evident ten years ago in early studies on nude mice, more recent data are very variable and controversial in this respect.

Serum concentrations of IgM, IgG1, IgG2b, IgG3 and IgA in C57BL/6 mice and their congenics at the lpr (lymphoproliferation) locus.

The serum concentrations of IgM, IgG1, IgG2b, IgG3 and IgA were determined in mice of C57BL/6 background, from weaning to one year of age, by quantitative isotype-specific, indirect double sandwich enzyme-linked immunosorbent assays (ELISAs). Only limited data could be obtained for the IgG2a isotype in the present study. The mean serum Ig levels found for 6-month-old B6 mice were 0.22 mg/ml for IgM, 0.28 mg/ml for IgG1, 1.22 mg/ml for IgG2b, 0.18 mg/ml for IgG3, 0.075 mg/ml for IgA and about 0.7 mg/ml for IgG2a. In comparison with mice of the wild strain, C57BL/6 mice homozygous at the lpr (lymphoproliferation) locus showed very high increases in serum Ig levels when older than 20 weeks. With 6-month-old B6 lpr mice, increases in concentration were found for all tested heavy chain isotypes: 6 to 6.5-fold for IgA (0.45 mg/ml) and IgG1 (1.82 mg/ml), 9-fold for IgG3 (1.6 mg/ml), 11 to 11.5-fold for IgM (2.44 mg/ml) and IgG2b (13.8 mg/ml) and about 8-fold for IgG2a (5.5 mg/ml). Therefore homozygosity at the lpr locus provides the conditions for generalized, poly-isotypic rather than isotype-specific restricted Ig enhancement. This observation may be more compatible with hyperinducibility of all B-cell subclasses than with excessive production of T-cell-derived factors whose activity would be expected to be restricted to some T-dependent subclasses, and at least to affect IgM-committed B cells to a lesser extent than other B-cell classes.