Peripheral binding site is involved in the neurotrophic activity of acetylcholinesterase

Acetylcholinesterase (AChE) catalyses the hydrolysis of the neurotransmitter acetylcholine and it has been implicated in several non-cholinergic actions, including neurite outgrowth and amyloid formation. We have studied the trophic function of brain AChE on neuronal cell metabolism and proliferation as well as the enzyme domain involved in such effects. Low AChE concentrations (0.1-2.5 nM) stimulated neurite outgrowth and induced cell proliferation as measured by MTT reduction and [3H]thymidine incorporation. The action of AChE was not affected by edrophonium and tacrine both active site inhibitors, but it was abolished by propidium and gallamine, two peripheral anionic binding site (PAS) ligands. We conclude that the PAS domain of AChE is involved in the neurotrophic activity of the enzyme.     

Identification of the mammalian homolog of the splicing regulator Suppressor-of-white-apricot as a thyroid hormone regulated gene.

Mammalian brain development is controlled by thyroid hormone through the regulation of target genes. In this study, we describe for the first time that a splicing regulator gene is under thyroid hormone control in the rat brain during the critical period of neuronal differentiation. By differential display, we have identified the mammalian homolog of the Drosophila splicing regulator Suppressor-of-white-apricot (SWAP) as a thyroid hormone-regulated gene in an immortal line of rat neuroblasts, E18 cells. Using Northern blotting and in situ hybridization, we found that expression of SWAP is under thyroid control in the developing rat brain. SWAP gene expression is highest during the first 10 days of life (P0-P10), preferentially in cerebral cortex, cerebellum, subventricular epithelium, piriform cortex, hippocampus, amygdala, and caudate putamen. At later stages (P15-P30) SWAP expression decreases, being detectable only in the cerebellum, hippocampus, and layers II/III of cerebral and piriform cortexes. We found that hypothyroidism causes an abnormal high level of SWAP RNA expression at P5-P15 throughout the brain except the cerebellum. Significantly, thyroid hormone treatment in vivo of hypothyroid animals led to a normalization of SWAP RNA expression. Furthermore, similar hormone treatment caused a decrease in SWAP expression in control rats. By modulating the expression of SWAP and perhaps other splicing regulators thyroid hormone may exert wide regulatory effects on multiple genes. The regulation of SWAP gene defines a novel mechanism of action of thyroid hormone which can be important for its effects in the developing brain.     

Encephalopathy with focal lesions due to Mycoplasma pneumoniae

Mycoplasma pneumoniae infections usually produce respiratory symptoms, that only exceptionally involve the nervous system. In this case, the infection generally causes an encephalitic picture characterized by impaired consciousness and seizures, and by normal or non-specific neuroradiological findings. However, four cases of M. pneumoniae infection associated with symmetrical lesions in the putamen and its external surrounding areas, and with extrapiramidal symptoms, have been recently published. We present the case of a patient with a clinical picture characterized by confusion, fever, and seizures, associated with a M. pneumoniae infection. The MRI study showed two symmetrical lesions that involved the areas just outside the putamen and disappeared coinciding with her clinical improvement. The present case would support that the encephalopathy associated with the M. pneumoniae infection shows a tendency to involve a particular region of the brain. Our case might represent the minimal expression of these characteristic lesions, which in the most benign cases would involve the areas immediately outside the putamen, and in other instances the putamen as well.     

Frequency of food intake by adolescent schoolchildren in Cantabria, Spain. Comparison with the consensus document: Food Guidelines for the Spanish Population

OBJECTIVE: To analyze food consumption patterns among schoolchildren in Cantabria and to compare results obtained with Spanish food guidelines for this population group. METHODS: A food frequency questionnaire was the chosen method, with some 53 food types divided into 15 groups. A total of 1,205 teenagers of both sexes aged between 14 and 18 attending 18 secondary schools in Cantabria completed the questionnaire. RESULTS: Milk, bread, fruit, greens and vegetables are the foodstuffs mostly consumed at the recommended frequencies. On the other hand, fish, meat, eggs, dairy products and pulse make up the least adequately consumed categories. Alcoholic drinks are imbibed to a high degree, with beer being the alcoholic most frequently drunk. Spirits are also drunk in larger quantities than wine. Alcohol consumption (beer, wines and spirits) increases significantly with age, being higher among males than females. CONCLUSIONS: Cantabrian schoolchildren follow a food consumption pattern which, generally speaking, does not tally with Spanish food recommendations for their age group. Educational and interventional strategies need to be developed with the aim of modifying such inappropriate food consumption.     

Differential effects of dietary Oenothera, Zizyphus mistol, and corn oils, and essential fatty acid deficiency on the progression of a murine mammary gland adenocarcinoma

The modulating effect of dietary enrichment in mistol seed oil (MO) containing 25% of alpha-linolenic acid (ALA), evening primrose oil (EPO) enriched in gamma-linolenic acid (GLA) and corn oil (CO) as sources of omega-6 and omega-9 fatty acids on the growth parameters of one transplantable mammary tumor were compared. Mice fed on different lipid formulae were inoculated with a mammary gland adenocarcinoma and different growth development tumor parameters were recorded. Results showed that corn oil feeding slowed down most of the tumor growth parameters, as did the EPO diet. MO also showed antitumor activity. Olein feeding, which induces an essential fatty acid deficiency (EFAD), increased the incidence and the multiplicity of metastases when compared with the controls. It may be concluded that a diet enriched in omega-6 fatty acids did not behave as a tumor promoter in this mammary gland tumor model. The antitumor activities of EPO and MO are corroborated in present experiments, suggesting that both oils may be of value in nutritional approaches of mammary gland tumor therapies. In addition, present data add further experimental proof about the proposed protumorigenic proneness induced by the EFAD state.