Role of folate receptor α in the partial rejuvenation of dentate gyrus cells: Improvement of cognitive function in 21-month-old aged mice.

Neuronal aging may be, in part, related to a change in DNA methylation. Thus, methyl donors, like folate and methionine, may play a role in cognitive changes associated to neuronal aging. To test the role of these metabolites, we performed stereotaxic microinjection of these molecules into the dentate gyrus (DG) of aged mice (an average age of 21 month). Folate, but not S-Adenosyl-Methionine (SAM), enhances cognition in aged mice. In the presence of folate, we observed partial rejuvenation of DG cells, characterized by the expression of juvenile genes or reorganization of extracellular matrix. Here, we have also tried to identify the mechanism independent of DNA methylation, that involve folate effects on cognition. Our analyses indicated that folate binds to folate receptor α (FRα) and, upon folate binding, FRα is transported to cell nucleus, where it is acting as transcription factor for expressing genes like SOX2 or GluN2B. In this work, we report that a FRα binding peptide also replicates the folate effect on cognition, in aged mice. Our data suggest that such effect is not sex-dependent. Thus, we propose the use of this peptide to improve cognition since it lacks of folate-mediated side effects. The use of synthetic FRα binding peptides emerge as a future strategy for the study of brain rejuvenation.

Matrix effect in second-order data: determination of dyes in a tanning process using vegetable tanning agents.

The aim of this paper is to determine the concentration of three dyes throughout the tanning process of leather using vegetable tanning agents with a sequential injection analyser with second-order data treatment. As the vegetable tanning agents used are highly absorbent species, we focus on three aspects: (i) difficulties with the resolution (ii) the reduction in the working concentration range; and (iii) matrix effects. Ideally, second-order instruments provide "second-order advantage"; i.e. calibration is possible in the presence of uncalibrated interfering species. However, if the interfering species change the instrumental response of the analyte (in scale or shape), standard additions must be used to ensure the accuracy of the estimated analyte concentration. Here we study the presence of matrix effects for three dyes in several samples in order to significantly improve the accuracy of predictions in the presence of such effects. We found that there were matrix effects in at least 80% of the samples with an alpha risk of 5%. We used this method to study the exhaustion of dyes in the dyeing process.

[Systemic necrotizing vasculitis in autopsy]. / Vasculitis necrosante sistémica en la autopsia.

OBJECTIVE: To analyze the characteristics of systemic necrotizing vasculitis observed in necropsy emphasizing the non-diagnosed cases until necropsy and to identify the reasons of clinical confusion. MATERIALS AND METHODS: Necropsies of adult patients performed in Hospital General La Paz, Madrid, from 1966 to 1977 were reviewed. Clinical manifestations, analytical changes and involvement of different organs were analyzed. The correspondence degree between clinical and necropsic diagnoses was studied. RESULTS: A total of 18 cases of necrotizing vasculitis were observed out of 3,980 necropsies. The most common clinical manifestations were fever and general syndrome (60%). The organs most commonly involved were kidney (94%) and gastrointestinal tract (56%). Diagnosis was revealed by necropsy in 39% of cases; in these cases, the incidence of heart failure and peripheral neuropathy was significantly lower, whereas digestive hemorrhage and liver, pancreas, adrenal gland, and bladder involvement was significantly higher. CONCLUSIONS: Systemic necrotizing vasculitis in underdiagnosed, which can be partly explained by the lack of specificity of the most common symptoms and the paucity of characteristic clinical and organ-specific manifestations which leads to confusion with more prevalent conditions.

[Hashimoto's thyroiditis and Sjögren syndrome. Association or autoimmune multiple syndrome?]. / Tiroiditis de Hashimoto y síndrome de Sjögren. Asociación o síndrome múltiple autoinmune?

A case of Hashimoto's thyroiditis associated with incomplete Sjögren's syndrome is revised. Both immune disorders are together not just as a casual event, but literature says that common mechanisms could have something to be. Previous publications express that autoimmune thyroid dysfunction is frequently associated with primary Sjögren's syndrome and should be sought clinically and by laboratory test in all these patients.

Phosphorylated, but not native, tau protein assembles following reaction with the lipid peroxidation product, 4-hydroxy-2-nonenal.

A correlation between hyperphosphorylation of tau protein and its aberrant assembly into paired helical filaments has lead to suggestions that phosphorylation controls assembly, but lacked a mechanistic basic. In this work, we have found that phosphorylated, but not native, tau protein is able to form polymers after the reaction with 4-hydroxy-2-nonenal, a highly toxic product of lipid peroxidation. Phosphorylation of tau by both proline or non-proline directed kinases, was able to assemble it into polymers.

The marine compound spisulosine, an inhibitor of cell proliferation, promotes the disassembly of actin stress fibers.

Spisulosine is a novel antiproliferative (antitumoral) compound of marine origin. In this work the molecular target for this toxic agent has been analyzed. In the presence of spisulosine, cultured cells change their morphology, first acquiring a fusiform morphology, and later becoming rounded without focal adhesions. Analysis of the cytoskeleton of treated cells indicate the absence of actin stress fibers.

[Prions: definition and diseases]. / Priones: concepto y enfermedades.

In this article we review the concept and terminology of prions, their replication and some current hypothesis on the nature of these infectious agents causing neurodegenerative diseases. This revision also summarizes the etiopathogenic, epidemiological, clinical and neuropathological features of the prion diseases or human transmissible spongiform encephalopathies, and some methods for their early diagnosis. Finally, we discuss the possible link between the bovine spongiform encephalopathy and the new cases of Creutzfeldt-Jakob disease identified in the United Kingdom.

Sporotrichosis in the metropolitan area of Cusco, Peru, and in its region.

Eight cases of sporotrichosis originating from the metropolitan area of Cusco, Peru, and its region are described, including the circumstances of infection and the isolation of Sporothrix schenckii from the lesions. This finding classifies this particular area with high altitude, low temperature and dry weather as an endemic zone of interest in the epidemiological and ecological study of Andean sporotrichosis. Among the eight cases observed, five were of the fixed cutaneous type and three were lymphocutaneous. Six patients were male and two female. Two paediatric cases were also observed. Therapy with potassium iodide was very satisfactory, whereas poor results were obtained with ketoconazole.