Diet-induced hyperhomocysteinemia increases amyloid-beta formation and deposition in a mouse model of Alzheimer's disease.

Hyperhomocysteinemia (HHcy) has been recognized as a risk factor for developing Alzheimer's disease (AD). However, its underlying molecular mechanisms are still elusive. Here we show that HHcy induces an elevation of amyloid beta (Abeta) levels and deposition, as well as behavioral impairments, in a mouse model of AD-like amyloidosis, the Tg2576 mice. This elevation is not associated with significant change of the steady state levels of the Abeta precursor protein (APP), beta- or alpha-secretase pathways, nor with the Abeta catabolic pathways. By contrast, HHcy significantly reduces glycogen synthase kinase 3 (GSK3) Ser21/9 phosphorylation, but not total GSK3 protein levels. Similar results are obtained in brains homogenates from a genetic mouse model of HHcy. In vitro studies show that homocysteine increases Abeta formation, reduces phosphorylated GSK3 levels, without changes in total APP and its metabolism, and these effects are prevented by selective GSK3 inhibition. Overall, these data support a potential link between GSK3 and the pro-amyloidotic effect of HHcy in vivo and in vitro.

Programa institucional de prevención y control de infecciones intrahospitalarias, bioseguridad y residuos sólidos

Contiene: I. Infecciones intrahospitalarias; II. Normas y procedimientos para el manejo adecuado de residuos sólidos hospitalarios

Xantoastrocitoma pleomórfico; relato de um caso / Pleomorphic xanthoastrocytoma: a case report

Os autores relatam o caso de uma mulher de 20 anos de idade, cujo primeiro sintoma foi cefaléia intensa, seguida de crise convulsiva generalizada. Foram realizadas radiografias simples, tomografia computadorizada e ressonância magnética do crânio, que revelaram formação expansiva parietal à direita, em íntimo contato com o corno occipital do ventrículo lateral. Observava-se, ainda, lise da tábua interna com expansão da tábua externa da calota craniana. Após a cirurgia e análise histopatológica da lesão, foi feito o diagnóstico de xantoastrocitoma pleomórfico.

Tuberculous skeletal muscle involvement in acute leukemia: report on two cases.

Bacterial infection of skeletal muscle (pyomyositis) is usually followed by abscess formation. The most commonly isolated pathogen is Staphylococcus aureus. Tuberculosis rarely affects patients with acute leukemia. The authors report on 2 patients, one with acute myelogenous leukemia and the other with acute lymphoblastic leukemia whose clinical course was complicated by tuberculous skeletal muscle abscesses. In both instances, musculoskeletal pain was accompanied by evidence of muscle abscesses by imaging studies of the painful areas. Therefore, in patients with acute leukemia and evidence of muscle abscesses with initial cultures negative for bacteria and fungi, one should include tuberculosis in the differential diagnosis.

[Epidermoid carcinoma in a median congenital cyst of the neck : a case report and literature review (author's transl)]. / Carcinome épidermoïde sur kyste congénital médian du cou. A propos d'une observation avec revue de la littérature médicale.

Thyroglossal duct cyst, a common clinical entity, may undergo malignant change. The majority of such malignancies are capillary adenocarcinomas; squamous cell carcinomas are rare. Only 7 cases have been reported since 1950. The authors present a case of a 65 years old man who died 16 months after the tumor's discovery.