RESUMO
Objective:To analyze the clinical features of patients with facial nerve schwannoma to raise awareness of the disease and potential future treatments.Method: A series of 16 cases with facial nerve schwannoma were retrospective analyzed, including initial symptoms, medical and treatment history, imaging findings,surgical technique and outcome. Result: Ten cases of them were initially misdiagnosed: six cases as sudden facial paralysis,two as cholesteatoma and two as vestibular schwannomas.The diagnosis were revised after MRI examination for first eight cases, and other two patients were identified as the FNS after the surgery.Conclusion:MRI is a very valuable examination for the diagnosis of facial schwannoma,especially for patients with recurrent or progressive facial paresis,long term otorrhea with facial paresis. The possibility of atypical facial schwannoma should be considered for the patients with isolated internal auditory canal and cerebellopontine angle tumor presenting only auditory symptoms without facial nerve symptoms.
RESUMO
The gene 1 of the Klebsiella phage K11 encoding the phage RNA polymerase was amplified using the polymerase chain reaction of the Pfu DNA polymerase, cloned and expressed under the control of tac promoter in Escherichia coli. Although the gene was efficiently expressed in E. coli BL21 cells at 37 degrees C, most of the K11 RNA polymerase produced was insoluble, in contrast to soluble expression of the cloned T7 RNA polymerase gene. Coexpression of the bacterial chaperone GroES and GroEL genes together did not help solubilize the K11 RNA polymerase. When the temperature of cell growth was lowered, however, solubility of the K11 RNA polymerase was increased substantially. It was found much more soluble when expressed at 25 degrees C than at 30 and 37 degrees C. Thus, the cloned K11 RNA polymerase gene was expressed in E. coli mostly to the soluble form at 25 degrees C. The protein was purified to homogeneity by chromatography using DEAE-Sephacel and Affigel-blue columns and was found to be active in vitro with the K11 genome or a K11 promoter. The purified K11 RNA polymerase showed highly stringent specificity for the K11 promoter. Low-level cross-reactivity was shown with the SP6 and T7 consensus promoters, while no activity shown with the T3 consensus promoter at all.
Assuntos
RNA Polimerases Dirigidas por DNA/genética , Escherichia coli/genética , Genes Virais , Podoviridae/enzimologia , Podoviridae/genética , Sequência de Bases , Clonagem Molecular , Temperatura Baixa , Primers do DNA/genética , RNA Polimerases Dirigidas por DNA/biossíntese , RNA Polimerases Dirigidas por DNA/isolamento & purificação , Expressão Gênica , Podoviridae/classificação , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Solubilidade , Especificidade da EspécieRESUMO
Polarization splitters that use an asymmetric branching waveguide and can be fabricated along the Z axis as well as the X axis of LiNbO(3) are proposed and demonstrated. In these devices, two polarization states are converted to two different spatial modes, and these modes are split by the asymmetric branching waveguide. The extinction ratios of the two polarization splitters are shown to be less than -12 dB.
