ABSTRACT
The present study is to explore the change process and distribution of phosphorylated DARPP-32 (p-DARPP-32) in rat brain including cortex, hippocampus and striatum and to further deduce whether p-DARPP-32 was possibly involved in epilepsy induced by repetitive low doses of pentylenetetrazol (PTZ). PTZ-induced epilepsy model in rat was established with 30 male SD rats randomly divided into 6 groups, control group and five trial groups [PTZ 1 h, PTZ 6 h, PTZ 24 h, PTZ 48 h and PTZ 72 h respectively, after onset of status epilepticus (SE)]. Immunohistochemistry and immunofluorescence double-labeling were used to detect the temporal time change and distribution of p-DARPP-32 expression and to analyze the coexpression of DARPP-32 and p-DARPP-32 in rat brain after the onset of PTZ-induced generalized SE. The results showed that there was a temporal time change of p-DARPP-32 expression in rat brain after the onset of SE. The number of p-DARPP-32-positive cells increased significantly and reached the peaks at the ends of 1 hour and 6 hours after the onset of SE, but decreased at the end of 24 hours. The moderate to strong p-DARPP-32-immunopositive neurons were observed in cortex, hippocampus and striatum, and located in cell cytoplasm and cell nucleus. Further immunofluorescence double-labeling revealed that denser colocalization of p-DARPP-32 and DARPP-32 in the neurons existed in the area mentioned above. Therefore, PTZ-induced SE may cause phosphorylation of DARPP-32 in rat brain. The temporal time change and distribution of p-DARPP-32 suggest that phosphorylation of DARPP-32 may be involved in PTZ-induced epilepsy in rat brain including cortex, hippocampus and striatum, and p-DARPP-32 may play a central role in the onset of SE.
Subject(s)
Animals , Male , Rats , Cerebral Cortex , Metabolism , Corpus Striatum , Metabolism , Dopamine and cAMP-Regulated Phosphoprotein 32 , Metabolism , Hippocampus , Metabolism , Neurons , Metabolism , Pentylenetetrazole , Rats, Sprague-Dawley , Status Epilepticus , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study the changes in biological behaviors of meningitis E. coli K1 strain E44 after deletion of polyphosphate kinase 1 (ppk1) gene and explore the role of ppk1 in the pathogenesis of E. coli K1-induced meningitis.</p><p><b>METHODS</b>The wild-type strain E. coli K1 and ppk1 deletion mutant were exposed to heat at 56 degrees celsius; for 6 min, and their survival rates were determined. The adhesion and invasion of the bacteria to human brain microvascular endothelial cells (HBMECs) were observed using electron microscopy and quantitative tests. HBMECs were co-incubated with wild-type strain or ppk1 deletion mutant, and the cytoskeleton rearrangement was observed under laser scanning confocal microscope.</p><p><b>RESULTS</b>The survival rate of the ppk1 deletion mutant was significantly lower than that of the wild-type strain after heat exposure. The ppk1 deletion mutant also showed lowered cell adhesion and invasion abilities and weakened ability to induce cytoskeleton rearrangement in HBMECs.</p><p><b>CONCLUSIONS</b>ppk1 gene is important for E.coli K1 for heat resistance, cell adhesion and invasion, and for inducing cytoskeletal rearrangement in HBMECs.</p>
Subject(s)
Humans , Brain , Cell Biology , Cells, Cultured , Cytoskeleton , Endothelial Cells , Cell Biology , Microbiology , Escherichia coli , Genetics , Physiology , Escherichia coli Proteins , Genetics , Gene Deletion , Phosphotransferases (Phosphate Group Acceptor) , GeneticsABSTRACT
ObjectiveTo report the first laboratory-confirmed human monocytic ehrlichiosis (HME) case in Shandong Province.MethodsThe epidemiological investigation was done by filling out questionaires.Blood sample was collected for detecting the specific 16S rRNA gene of Anaplasma phagocytophilumandEhrlichiachaffeensisbynested-polymerasechainreaction(PCR).ResultsThis case was characterized by acute onset of fever,leukopenia and thrombocytopenia.The specific 16S rRNA gene of Anaplasma phagocytophilum was negative and the specific 16S rRNA gene of Ehrlichia chaffeensis was positive by nested PCR test.The PCR product was sequenced.The homology was above 99 ％ between the acquired nucleotide acid sequence and the Ehrlichia chaffeensis sequences registered in GenBank.ConclusionThe Ehrlichia chaffeensis infection exists in Shandong Province,which warrants further research on these natural loci of HME in this area.