miR-132/212 knockout mice reveal roles for these miRNAs in regulating cortical synaptic transmission and plasticity

miR-132 and miR-212 are two closely related miRNAs encoded in the same intron of a small non-coding gene, which have been suggested to play roles in both immune and neuronal function. We describe here the generation and initial characterisation of a miR-132/212 double knockout mouse. These mice were viable and fertile with no overt adverse phenotype. Analysis of innate immune responses, including TLR-induced cytokine production and IFNβ induction in response to viral infection of primary fibroblasts did not reveal any phenotype in the knockouts. In contrast, the loss of miR-132 and miR-212, while not overtly affecting neuronal morphology, did affect synaptic function. In both hippocampal and neocortical slices miR-132/212 knockout reduced basal synaptic transmission, without affecting paired-pulse facilitation. Hippocampal long-term potentiation (LTP) induced by tetanic stimulation was not affected by miR-132/212 deletion, whilst theta burst LTP was enhanced. In contrast, neocortical theta burst-induced LTP was inhibited by loss of miR-132/212. Together these results indicate that miR-132 and/or miR-212 play a significant role in synaptic function, possibly by regulating the number of postsynaptic AMPA receptors under basal conditions and during activity-dependent synaptic plasticity

Evaluation of surgical cavities filled with three types of calcium sulfate

The aim of this study was to evaluate histologically, three types of calcium sulfate - Merck (Brazil), Surgiplaster (Italy) and Capset (USA) - in surgically created defects on rabbit femurs. Twenty male New Zealand rabbits were used. Two surgical bone defects (5 mm diameter x 8 mm depth) were created on each distal epiphysis using a #3 Dentoflex trephine bur. Defects were filled with: group 1 - di-hydrated calcium sulfate (Merck); group 2 - Capset (Lifecore-USA); group 3 - Surgiplaster (Classimport-Italy); group 4 - control (blood clot). The animals were sacrificed 30, 60, 90 and 180 days postoperatively. Semi-serial 6-mm-thick sections were obtained, stained with hematoxylin and eosin and examined under light microscopy. Bone defects treated with calcium sulfate exhibited new bone formation regardless of the product trademark

Momento ideal para a endarterectomia de carótida após um AVC recente

Vários estudos prospectivos de escolha aleatória confirmaram a eficácia da endarterectomia de carótida na prevenção de novos acidentes vasculares cerebrais (AVC) em pacientes sintomáticos com estenose grave na carótida. Entretanto, o timing da endarterectomia ainda é controverso. A cirurgia precoce pode estar associada à hemorragia intracerebral e à extensão do infarto inicial. A cirurgia tardia pode expor o paciente à recorrência do AVC e à oclusão da artéria carótida. Os estudos que avaliaram o intervalo de tempo para a endarterectomia são retrospectivos e não randomizados. Na ausência de um estudo prospectivo randomizado comparando endarterectomia precoce e tardia, uma abordagem para se interpretar os resultados das séries cirúrgicas é a comparação destes com a história natural do AVC isquêmico. Os autores descrevem os argumentos em favor da cirurgia precoce, a história natural do AVC isquêmico e os fatores de risco associados ao AVC no perioperatório da endarterectomia