Le sexuel de la psychanalyse

Our liberal society is moving toward abolishing the boundaries between child sexuality and adult, genital sexuality, although the very existence of child sexuality incites controversy. This paper once again describes the construct of child sexuality and tries to distinguish it from adult sexuality and show how it plays a lead role in the humanisation process and in culture.     

Automated LC-MS method for the fast stereoselective determination of methadone in plasma.

Methadone (MTD) is a chiral drug widely used for the treatment of opioid dependence for which a rapid analytical method for the determination of each enantiomer would be advantageous. In order to improve method sensitivity and to automate the entire analytical process, a column-switching configuration has been developed. An online extraction system coupled to a cellulose-based chiral stationary phase (CSP), namely Chiralcel OJ-R, was used and detection was performed by mass spectrometry. Fifty microl of plasma were injected into the liquid chromatography-mass spectrometry (LC-MS) system after addition of acetonitrile (ACN) containing methadone deuterated D9 (MTD-D9) (internal standard) and centrifugation. For the rapid extraction step, a large particle size support was selected. A baseline separation of MTD enantiomers was obtained in less than 12 min. Trueness and precision were evaluated with control samples at 500 ng/ml of (R,S)-methadone. Trueness values were 106.6% and 103.0% for (R)-MTD and (S)-MTD, respectively, with a coefficient of variation inferior to 2.5% for both compounds. Finally, a good concordance was found using this method for analysis of plasma samples from patients in maintenance treatment as compared to a previously described HPLC-UV method after liquid-liquid extraction.     

Developmental spectrum of the excitotoxic cascade induced by ibotenate: a model of hypoxic insults in fetuses and neonates

Ibotenate, a glutamatergic agonist, was used to study the spectrum of excitoxic disturbances at different ages of cerebral development. Cultures of whole mouse embryo were submitted to ibotenate at E8 for 20 h: during the phase of early premigratory differentiation; ibotenate did not induce any detectable histological lesion. During migration of supragranular neurons, newborn hamsters intracerebrally injected at P0 with ibotenate display neuronal migration disorders graded from nodular heterotopias to extensive laminar heterotopias mimicking some aspects of lissencephalic and double-cortex syndromes. After completion of neuronal layer V, P0 mice injected with ibotenate exhibit laminar neuronal depopulation of layer V-VIa mimicking human micro-gyria. At P5 in mouse, after completion of neuronal migration of the cortical plate, ibotenate induces neuronal loss in all cortical layers and the formation of porencephalic cysts. This study emphasizes the dramatic role played by glutamate in brain development, in the occurrence of neuronal migration disorders in the cortex. and in grey and white matter damage.     

Immunoassays for proteins alkylated by nicotine-derived N-nitrosamines

Polyclonal antibodies recognizing the pyridyloxobutyl (POB) moiety of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were produced in rabbits immunized either with POB-bovine albumin or POB-Sepharose. The POB intermediates necessary to modify the protein were generated by alkaline (pH 9.0) treatment of the synthetic precursor 4-(carbethoxynitrosamino)-1-(3-pyridyl)-1-butanone. In a competitive enzyme linked immunoabsorbent assay (ELISA), 70 pmole NNK inhibited 50% of the binding of the anti-POB antibodies to POB-protein absorbed on microtiterplates. This 50% inhibition varied from 70 pmole to 200 nmole using a series of NNK analogues, depending on the integrity of the POB moiety. Immunological techniques initiated in this study detect NNK-protein conjugates or measure the quantity of POB groups liberated upon alkaline or acid treatment of NNK modified protein.     

Childhood fractures are associated with decreased bone mass gain during puberty: an early marker of persistent bone fragility?

Whether peak bone mass is low among children with fractures remains uncertain. In a cohort of 125 girls followed over 8.5 years, 42 subjects reported 58 fractures. Among those, BMC gain at multiple sites and vertebral bone size at pubertal maturity were significantly decreased. Hence, childhood fractures may be markers of low peak bone mass acquisition and persistent skeletal fragility. INTRODUCTION: Fractures in childhood may result from a deficit in bone mass accrual during rapid longitudinal growth. Whether low bone mass persists beyond this period however remains unknown. MATERIALS AND METHODS: BMC at the spine, radius, hip, and femur diaphysis was prospectively measured over 8.5 years in 125 girls using DXA. Differences in bone mass and size between girls with and without fractures were analyzed using nonparametric tests. The contribution of genetic factors was evaluated by mother-daughter correlations and that of calcium intake by Cox proportional hazard models. RESULTS: Fifty-eight fractures occurred in 42 among 125 girls (cumulative incidence, 46.4%), one-half of all fractures affecting the forearm and wrist. Girls with and without fractures had similar age, height, weight. and calcium intake at all time-points. Before and during early puberty, BMC and width of the radius diaphysis was lower in the fracture compared with no-fracture group (p < 0.05), whereas aBMD and BMAD were similar in the two groups. At pubertal maturity (Tanner's stage 5, mean age +/- SD, 16.4 +/- 0.5 years), BMC at the ultradistal radius (UD Rad.), femur trochanter, and lumbar spine (LS), and LS projected bone area were all significantly lower in girls with fractures. Throughout puberty, BMC gain at these sites was also decreased in the fracture group (LS, -8.0%, p = 0.015; UD Rad., -12.0%, p = 0.004; trochanter, -8.4%, p = 0.05 versus no fractures). BMC was highly correlated between prepuberty and pubertal maturity (R = 0.54-0.81) and between mature daughters and their mothers (R = 0.32-0.46). Calcium intake was not related to fracture risk. CONCLUSIONS: Girls with fractures have decreased bone mass gain in the axial and appendicular skeleton and reduced vertebral bone size when reaching pubertal maturity. Taken together with the evidence of tracking and heritability for BMC, these observations indicate that childhood fractures may be markers for low peak bone mass and persistent bone fragility.     

Glucocorticoids Decrease Hippocampal and Prefrontal Activation during Declarative Memory Retrieval in Young Men

Glucocorticoids (GCs, cortisol in human) are associated with impairments in declarative memory retrieval. Brain regions hypothesized to mediate these effects are the hippocampus and prefrontal cortex (PFC). Our aim was to use fMRI in localizing the effects of GCs during declarative memory retrieval. Therefore, we tested memory retrieval in 21 young healthy males in a randomized placebo-controlled crossover design. Participants encoded word lists containing neutral and emotional words 1 h prior to ingestion of 20 mg hydrocortisone. Memory retrieval was tested using an old/new recognition paradigm in a rapid event-related design. It was found that hydrocortisone decreased brain activity in both the hippocampus and PFC during successful retrieval of neutral words. These observations are consistent with previous animal and human studies suggesting that glucocorticoids modulate both hippocampal and prefrontal brain regions that are crucially involved in memory processing. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Sclerosed liver hemangioma mimicking malignant tumor at MR imaging: Pathologic correlation

This case report illustrates atypical magnetic resonance (MR) imaging findings in a liver hemangioma mimicking a malignant lesion—lower signal intensity than cerebrospinal fluid on T2-weighted spin-echo images and lack of early enhancement on dynamic contrast material—enhanced gradient-echo images. Pathologic analysis demonstrated nearly total replacement of the vascular cavities by dense fibrous tissue. In this rare, sclerosed form, this lesion could not be defined as a hemangioma with MR imaging.     

Quantification of oxidative DNA modifications in mitochondria

Specific repair endonucleases were used to quantify oxidativemodifications in mitochondrial DNA (mtDNA) from rat liver andfrom porcine liver and kidney by means of a relaxation assay.In rat liver mitochondria the number of modifications sensitiveto formamidopyrimidine-DNA glycosylase (FPG protein), whichinclude 8-hydroxyguanine (8-oxo-7, 8-dihydro-guanine) residues,was only 0.8±0.2 per 10⁵ base pairs (bp). Even lowervalues were observed in porcine kidney (0.5±0.3 per 10⁵bp) and liver (0.4±0.2 per 10⁵ bp). The numbers of sitesof base loss (AP sites) sensitive to T4 endonuclease V and of5,6-dihydropyrimidines sensitive to endonuclease III were lessthan 0.2 per 10⁵ bp in all cases. The data provide evidencethat the steady-state levels of oxidative mtDNA modificationsare low under physiological conditions, either because reactiveoxygen species generated in the mitochondria are instantly inactivatedor because of efficient DNA repair processes inside mitochondria.