Intrathecal injection of GDNF and BDNF induces immediate early gene expression in rat spinal dorsal horn

Glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) are potent trophic factors for dorsal root ganglion cells. In addition, these factors are produced in subsets of dorsal root ganglion cells and transported anterogradely to their terminals in the superficial dorsal horn of the spinal cord, where they constitute the only source of GDNF and BDNF. We investigated the effect of 10 mug GDNF and BDNF injected by lumbar puncture on the expression of the immediate early gene (IEG) products c-Fos, c-Jun, and Krox-24 in the adult rat dorsal horn. In the dorsal horn of S1 spinal segments, GDNF and BDNF induced a strong increase in IEG expression, which was most pronounced in laminae I and II (2.9- to 4.5-fold). More distal from the injection site, in the dorsal horn of L1/L2 spinal segments, the increase in IEG expression was less pronounced, suggesting a concentration-dependent effect. In order to explain the effects of intrathecally injected GDNF, we investigated whether lumbo-sacral dorsal horn neurons expressed RET protein, the signal-transducing element of the receptor complex for GDNF. It was found that several of these neurons contained RET immunoreactivity and that some of the RET-labeled neurons had the appearance of nociceptive-specific cells, confirming their presumed role in pain transmission. Additionally, using double-labeling immunofluorescence combined with confocal microscopy, it was found that after intrathecal GDNF injection 35% of c-Fos-labeled cells were also labeled for RET. These results demonstrate that intrathecally administered GDNF and BDNF induce IEG expression in dorsal horn neurons in the adult rat, supposedly by way of their cognate receptors, which are present on these neurons. We further suggest that the endogenous release of GDNF and BDNF, triggered by nociceptive stimuli, is involved in the induction of changes in spinal nociceptive transmission as in various pain states.     

Performance of asialotransferrin in detecting alcohol abuse

BACKGROUND: The spectrum of alcohol use disorders covers hazardous use, alcohol abuse, and alcohol dependence. The present study evaluated the performance of asialotransferrin, a newly proposed biomarker for alcohol use disorders, in detecting alcohol abuse and alcohol dependence. METHOD: A 4-month trial was conducted in three groups of participants: alcohol abusers and alcohol-dependent patients, as defined in DSM-IV, and a control group. Asialotransferrin was assayed by capillary zone electrophoresis. RESULTS: Asialotransferrin demonstrated a sensitivity of 0.34 and a specificity of 1.00 for alcohol abuse. The sensitivity of asialotransferrin increased to 0.57 in alcohol-dependent patients. CONCLUSION: Despite the high specificity of asialotransferrin in alcohol use disorders, its sensitivity is too low to make it a useful marker of alcohol abuse.     

Injury-related dynamic myelin/oligodendrocyte axon-outgrowth inhibition in the central nervous system

CONTEXT: By contrast with the glial scar, myelin was considered a constitutive static inhibitory barrier unreactive to lesions in the central nervous system (CNS). However, recent results suggest considerable add-on inhibition of myelin as a result of CNS injury. Furthermore, catastrophic events cause morphological and biochemical changes in the axon itself. This results in the accumulation of cytoskeleton components and intraaxonal transported proteins paralleled by extensive membrane remodelling at the axonal tip (a process called axotomy) which might modify the axonal response to its inhibitory environment. STARTING POINT: Ji-Eun Kim and colleagues recently reported an axonal subpopulation with a different capacity to respond to myelin inhibitors (Neuron 2004; 44: 439-51). Axonal specificity but also evidence for injury reactivity summarised here challenges our understanding of axon-growth inhibition in the injured CNS. This might be due to (i) qualitative and quantitative enrichment of the periaxonal environment by myelin/oligodendrocytes, (ii) increased axonal sensitivity to its inhibitory environment, and (iii) axons and lesion-induced, altered axonal signalling. WHERE NEXT? Postlesional reactive inhibition of myelin or the oligodendrocyte necessitates the development of novel screening approaches and therapeutic agents to promote axonal regeneration. Moreover, we need to improve our understanding of the pathophysiology of the lesion to find more efficient experimental strategies to restore neurological function.     

Potential MRI interpretation model: differentiation of benign from malignant breast masses

OBJECTIVE: Our objective was to increase the accuracy of breast MRI using a semiquantitative analysis of typical MRI features and their diagnostic potential. The prevalence of recently reported MRI signs of breast lesions were analyzed and compared with other well-known signs. CONCLUSION: New MRI features, especially from T2-weighted images, are promising for more reliable and accurate interpretation of breast lesions. Prospective studies of these findings are required to define cut-off values and test clinical practicality.     

Colobomas of the iris and choroid and high signal intensity cerebral foci on T2-weighted magnetic resonance images in Klinefelter's syndrome

A 5-year-old boy presented with ocular anomalies including microphthalmos, colobomas of the iris, choroid, and optic nerve head, and strabismus. Magnetic resonance imaging of the head showed multiple bilateral asymmetric high signal intensity foci in the subcortical and periventricular white matter. Genetic counseling disclosed a 47,XXY karyotype.     

Determinant factors in Ecuador related to pregnancy among adolescents aged 15 or less

OBJECTIVE: Determine social factors related to pregnancy among young adolescents. METHODS: We obtained socio-demographic data from early adolescent nulliparas aged < or = 15 years. RESULTS: During the study period at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil-Ecuador 201 early adolescent nulliparous patients of low socio-economic status were surveyed and compared with 201 low socio-economic nulliparous controls aged 20 to 30. Mean age of adolescents was 14+/-0.6 years, 58.7% of them were aged 14. Age of menarche and sexual initiation was lower among adolescents (11.8+/-0.9 vs 12.8+/-2 years and 12.6+/-1.1 vs 16.2+/-5 years, respectively, p<0.05). A higher rate of adolescents initiated sexually before menarche onset (18.4% vs 5%, p<0.05). The rate of those who wanted to become pregnant, had adequate prenatal care and had knowledge of conception, used contraception or had knowledge of any contraceptive method prior to pregnancy was significantly lower in adolescents (16.9% vs 86.5%; 37.3% vs 94.5%; 18% vs 70.1%; 6.5% vs 89.5%; 42.8% vs 84.5%, respectively, p<0.05). Age of sexual partner was lower in the adolescent group (20.4+/-3.4 vs 30+/-8 years, p<0.05). Compared to controls, higher rates of adolescents were school dropouts, had problems with the law and were involved in domestic violence (87% vs 9.9%, 7.5% vs 0.5%, 44.7% vs 2.5%, respectively, p <0.05). None of the adolescents were living with mother and father in a complete family structure. Parental illiteracy was higher among adolescents (9% vs 3.5%, p < 0.05). CONCLUSION: In this low socio-economic population, early sexual initiation, poor reproductive health knowledge and the disruption of family structure were the main social factors related to pregnancy among adolescents aged 15 or less.