RESUMO
Shikimic acid is an important metabolic intermediate with various applications. This paper presents a novel control strategy for the construction of shikimic acid producing strains, without completely blocking the aromatic amino acid biosynthesis pathways. Growth phase-dependent expression and gene deletion was performed to regulate the aroK gene expression in the shikimic acid producing Escherichia coli strain, SK4/rpsM. In this strain, the aroL and aroK genes were deleted, and the aroB, aroG*, ppsA, and tktA genes were overexpressed. The relative amount of shikimic acid that accumulated in SK4/rpsM was 1.28-fold higher than that in SK4/pLac. Furthermore, a novel shikimic acid production pathway, combining the expression of the dehydroquinate dehydratase-shikimate dehydrogenase (DHQ-SDH) enzyme from woody plants, was constructed in E. coli strains. The results demonstrated that a growth phase-dependent control of the aroK gene leads to higher SA accumulation (5.33 g/L) in SK5/pSK6. This novel design can achieve higher shikimic acid production by using the same amount of medium used by the current methods and can also be widely used for modifying other metabolic pathways.
Assuntos
Oxirredutases do Álcool/metabolismo , Proteínas de Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Glicerol/metabolismo , Ácido Chiquímico/metabolismo , Oxirredutases do Álcool/genética , Vias Biossintéticas , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Cinética , Engenharia Metabólica , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas de Plantas/genética , Piruvato Sintase/genética , Piruvato Sintase/metabolismoRESUMO
Yarrowia lipolytica was usually transformed by heat shock, but linearized integrative vectors always resulted in a low transformation efficiency when electroporation was used. To develop a high efficiency integrative transformation method by electroporation of F. lipolytica, we report here that pretreatment of F. lipolytica with 150 mM LiAc for 1 h before electroporation will approximately 30-fold of increase transformation efficiency. A cell concentration of 10(10)/ml and instrument settings of 1.5 kV will generate the highest transformation efficiencies. We have developed a procedure to transform F. lipolytica that will be able to yield an efficiency of 2.1 × 10(4) transformants/ug for integrative linear DNA. With our modifications, the electroporation procedures became a very efficient and reliable tool for F. lipolytica transformation.
Assuntos
Acetatos/farmacologia , Ditiotreitol/farmacologia , Eletroporação/métodos , Transformação Genética/genética , Yarrowia/genética , Contagem de Colônia Microbiana , Meios de Cultura , DNA Fúngico/genética , Yarrowia/efeitos dos fármacos , Yarrowia/crescimento & desenvolvimentoRESUMO
We described a patient who was diagnosed of Tetralogy of Fallot with right arch. Dorsal aortic aneurysm was found later confirmed by cardiac catheterization and reconstruction of 3D computer tomography. To our knowledge, the combination of Tetralogy of Fallot and dorsal aortic aneurysm had never been reported.
Assuntos
Aorta Torácica/anormalidades , Aneurisma da Aorta Torácica/complicações , Aneurisma da Aorta Torácica/diagnóstico , Tetralogia de Fallot/complicações , Tetralogia de Fallot/diagnóstico , Aorta Torácica/patologia , Feminino , Humanos , LactenteRESUMO
Postoperative chylothorax is sometimes difficult to be managed either by conventional therapies or by surgery. Herein, we report the experience of octreotide therapy for intractable postoperative chylothorax in two children (one was severe tetralogy of Fallot received Blalock-Taussing shunt, and the other was a single ventricle received bi-directional Glenn shunt) and review the literature on octreotide efficacy.
Assuntos
Quilotórax/tratamento farmacológico , Octreotida/uso terapêutico , Complicações Pós-Operatórias/tratamento farmacológico , Feminino , Humanos , Lactente , Recém-Nascido , Somatostatina/análogos & derivados , Somatostatina/uso terapêuticoRESUMO
OBJECTIVE: To investigate whether renal vasculitis is the sole cause or merely a contributing cause of renal inflammation in Kawasaki disease (KD). STUDY DESIGN: This prospective study in a university medical center in Taiwan enrolled 24 children with KD between June 2004 and November 2005. All patients underwent a technetium-99 m dimercaptosuccinic acid scintigraphy single-photon emission computed tomography scan, the results of which were used to group the patients with KD as with or without renal involvement. Urine samples underwent a cytokine analysis. Renal Doppler ultrasonography was used to evaluate renal vasculitis by measuring the pulsatility index (PI) and resistance index (RI). RESULTS: Ten of the 24 patients (42%) with renal inflammatory foci were the study group; the remainder composed the control group. Urinary interleukin (IL)-6 levels were significantly higher in the study group (496.7 +/- 310.9 vs 115.0 +/- 65.9 ng/g urinary creatinine; P < .01), as were PI values (1.85 +/- 0.70 vs 1.44 +/- 0.53; P < .05). Urinary IL-6 levels and PI values were significantly (P < .05) correlated. CONCLUSIONS: Increased urinary IL-6 and elevated renal Doppler measures suggest that immune-mediated vasculitis is one of the mechanisms causing renal inflammation in KD.
