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Based on the transcriptome analysis data of a Bacillus licheniformis, a novel bidirectional promoter was identified from the strain and its transcriptional strength was analyzed. The expression level of a Bacillus clausii derived alkaline protease gene driven by the bidirectional promoter was studied by using the known strong constitutive promoter pShuttle-09 as a control. Three recombinant expression vectors and the corresponding recombinant bacteria were constructed. Under the control of the new promoter pLA and its reverse promoter pLB, the alkaline protease expression level respectively reached 164 U/mL and 111 U/mL. The results indicated that the transcription strength of pLA was significantly higher than that of pShuttle-09 and pLB, and both the pLA and pLB promoters could initiate the expression of the alkaline protease. Thus, it provides a new expression element for the heterogenous genes in Bacillus sp. and a new idea for the co-expression of two genes in one prokaryotic strain.
Assuntos
Bacillus subtilis , Regiões Promotoras GenéticasRESUMO
Objective To investigate the changes of excitatory amino acids (EAAs) of cerebrospinalfluid (CSF) in patients with delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Method The EAAs levels of CSF including glutamate (Glu) and aspartate (Asp) in 24 patients with DEACMP and 20 controls with migraine were measured by high performance liquid chromatography( HPLC ).Results Glu and Asp levels in patients with DEACMP were significantly higher than those of the controls [(3.76 ± 1.52) μmol/L vs ( 1.55 ± 1.03 ) μmol/L, (0.73 ± 0.44) μmol/L vs (0.38 ± 0.33 ) μmol/L, P all <0.01]. Glu and Asp levels in moderate and severe DEACMP patients were higher than those in mild DEACMP patients. Conclusion It suggests that EAAs participated in the pathogenesis of DEACMP. The Glu and Asp levels in CSF may be regarded as indicator of DEACMP.
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Objective To study the clinical feature of ciguatera fish poisoning.Methods Thirty-nine patients with ciguatera fish poisoning were observed.Results The clinical symlptoms of ciguatera poisoning usually began to appear 2～10 hours after eating a poisonous fish and could be classified into three broad groups:neurological,gastrointestinal cardiovascular symptoms.Gastrointes tinal symptoms were the most common complaint.Neurological symptoms generally stayed for 1～2 weeks.The clinical picture was characterized by temperature reversal.Conclusion Ciguatera poisoning can be differentiated by unique features affecting the neurological system.