Biomedical subjects

Qin Ye

Publications and source records attributed to Qin Ye.

10 recordsLinked to original sources

PubMed2004

The role of aquaporin RWC3 in drought avoidance in rice.

Although the discovery of aquaporins in plants has resulted in a paradigm shift in the understanding of plant water relations, the relationship between aquaporins and drought resistance still remains elusive. From an agronomic viewpoint, upland rice is traditionally considered as showing drought avoidance. In the investigation of different morphological and physiological responses of upland rice (Oryza sativa L. spp indica cv. Zhonghan 3) and lowland rice (O. sativa L. spp japonica cv. Xiushui 63) to water deficit, we observed young leaf rolling and the remarkable decline of cumulative transpiration in the upland rice. The expression of water channel protein RWC3 mRNA was increased in upland rice at the early response (up to 4 h) to the 20% polyethylene glycol (PEG) 6000 treatment, whereas there was no significant expression changes in lowland rice. Protein levels were increased in upland rice and decreased in lowland rice at 10 h after the water deficit. The up-regulation of RWC3 in upland rice fits well with the knowledge that upland rice adopts the mechanism of drought avoidance. The physiological significance of this RWC3 up-regulation was then explored with the over-expression of RWC3 in transgenic lowland rice (O. sativa L. spp japonica cv. Zhonghua 11) controlled by a stress-inducible SWPA2 promoter. Compared to the wild-type plant, the transgenic lowland rice exhibited higher root osmotic hydraulic conductivity (Lp), leaf water potential and relative cumulative transpiration at the end of 10 h PEG treatment. These results indicated that RWC3 probably played a role in drought avoidance in rice.

Animals↗

PubMed2004

Modeling guidelines for integration into clinical workflow.

The success of clinical decision-support systems requires that they are seamlessly integrated into clinical workflow. In the SAGE project, which aims to create the technological infra-structure for implementing computable clinical practice guide-lines in enterprise settings, we created a deployment-driven methodology for developing guideline knowledge bases. It involves (1) identification of usage scenarios of guideline-based care in clinical workflow, (2) distillation and disambiguation of guideline knowledge relevant to these usage scenarios, (3) formalization of data elements and vocabulary used in the guideline, and (4) encoding of usage scenarios and guideline knowledge using an executable guideline model. This methodology makes explicit the points in the care process where guideline-based decision aids are appropriate and the roles of clinicians for whom the guideline-based assistance is intended. We have evaluated the methodology by simulating the deployment of an immunization guideline in a real clinical information system and by reconstructing the workflow context of a deployed decision-support system for guideline-based care. We discuss the implication of deployment-driven guideline encoding for sharability of executable guidelines.

Decision Making, Computer-Assisted↗

PubMed2004

Executing clinical practice guidelines using the SAGE execution engine.

We report the first successful test of an interoperable guideline execution engine that interprets encoded clinical guideline content and executes that content via functions of a target clinical information system (CIS). For this test, an exemplar immunization guideline was encoded in the SAGE guideline model using standards-based information models and terminologies. This guideline content was subsequently executed using the prototype SAGE guideline execution engine, which interacts through standards-based VMR/Action services to instantiate real-time guideline recommendations via existing functions of the target CIS. In this paper, we describe our test implementation and highlight the significance and implications of each component of our deployment architecture

Decision Making, Computer-Assisted↗

PubMed2003

Angiostatin production in cultivation of recombinant Pichia pastoris fed with mixed carbon sources.

A recombinant strain of Pichia pastoris with a phenotype of MutS was used to produce angiostatin. Due to the low methanol consumption rate of this strain, both methanol and glycerol feedings, that produced oscillation in dissolved O2 concentration, were used during the expression phase to improve cell growth and angiostatin expression. However, enhanced cell growth led to nitrogen limitation that suppressed further production of angiostatin, but addition of ammonia allowed angiostatin concentration to reach 108 mg l(-1) after an expression period of 96 h. The ratio of consumed glycerol to methanol of 1.5:1 (w/w) in the expression phase suggested that methanol played an important role in the metabolism of carbon sources.

Ammonia↗

PubMed2003

[Expression and characterization of Kringle 1-5 domains of human plasminogen].

The cDNA encoding Kringle 1-5 domains of human plasminogen (designated as K1-5), obtained from HepG2 by RT-PCR, was cloned into expression vector pHIL-S1. The recombinant plasmid pHIL-K1-5 was transformed into Pichia pastoris GS115 and the recombinant yeast was induced by methanol to express the recombinant protein. The expressed protein was purified by lysine affinity chromatography. The recombinant K1-5 inhibited the growth of bovine aortic endothelial cells (BAEC) stimulated by the basic fibroblast growth factor (bFGF), in a dosage-dependent manner, with a half maximal concentration of 14 mg/L. And rhK1-5 inhibited 47% of the BAEC migration stimulated by bFGF at the concentration of 50 mg/L. rhK1-5 also affected the cell cycle of BAEC and caused G(0)-G(1) arrest at the concentration of 14 mg/L.

Animals↗

PubMed2003

[Feeding of mixed-carbon-resource during the expression phase in cultivation of recombinant Pichia pastoris expressing angiostatin].

A recombinant strain of Pichia pastoris with a phenotype of Muts was used to produce angiostatin in a 5-L fermentor. The methanol utilization ability of the present strain was weak, which resulted in extremely low growth rate and angiostatin productivity during the expression phase with methanol as the sole carbon source. To enhance the cell density and angiostatin expression level, mixed-carbon-source of glycerol-methanol was used in the expression phase. The methanol concentration was well controlled at 5 g/L by a methanol sensor and control system, and glycerol was continuously fed into the fermentor to achieve a higher cell density. 120 g/L of cells and 39 mg/L of angiostatin were reached at the end of fermentation which lasted 110 h. The mean specific cell growth rate in the expression phase was 0.01 h(-1), and the mean specific angiostatin productivity was 0.006 mg/(g x h). According to the data obtained in several runs of fermentation in which glycerol was fed at different rates, a higher mean specific angiostatin productivity was reached at the mean specific cell growth rate of 0.012 h(-1). To avoid the repression of angiostatin expression caused by residual glycerol and ethanol accumulation due to overfeeding of glycerol, glycerol addition was controlled to produce continuous oscillations in dissolved oxygen, because the change of dissolved oxygen concentration could deliver the information of available carbon source in the fermentation broth. Controlled glycerol feeding also avoided the problem of oxygen limitation brought by high cell density, and thus decreased the cooling requirement of the fermentor. Cell density reached 150 g/L at the end of fermentation, and angiostatin level reached 108 mg/L after an expression period of 96 h when the mean specific growth rate was maintained at 0.012 h(-1) by using the glycerol feeding strategy to result in the oscillations in dissolved oxygen. The mean specific angiostatin productivity was improved to 0.02 mg/(g x h). The apparent cell yield on glycerol and methanol were respectively 0.69 g/g and 0.93 g/g, higher than those in the fermentation without using the feeding strategy with dissolved oxygen as the indicator of metabolism.

Angiostatins↗

PubMed2003

[Selection of acetate-tolerant mutants from Escherichia coli DH5alpha and the metabolic properties of mutant DA19].

Esherichia coli DH5alpha is one of the widely used host strains in genetic engineering. However, foreign gene expression level in this strain is seriously inhibited due to its great sensitivity to the accumulated metabolite, acetate. This study aimed at improving the tolerance of this strain against acetate. Cells of E. coli DH5alpha were irradiated with 60Co, and subsequently continuous culture of the irradiated cells was conducted with gradual increase in the dilution rate and the selective pressure, acetate concentration in the medium. The mutants were picked up on MA plates which contained 5g/L sodium acetate. 5 strains with great improvement in acetate tolerance were obtained, among which DA19 was the best. In cultivation of DA19 in complex media YPS and YPS2G, the cell density, maximum specific growth rate and acetate produced were respectively 1.17 and 1.05, 1.08 and 1.27, and 0.06 and 0.59 times of those of DH5alpha. In a chemically defined medium, the cell density of DA19 was 3.4-fold of that of DH5alpha. The cell density of DA19 in a medium containing 10g/L sodium acetate was comparable to that of DH5alpha in the same medium without the addition of acetate.

Acetates↗

PubMed2002

[Cloning and expression of Vitreoscilla hemoglobin in Streptomyces aureofaciens].

Vitreoscilla hemoglobin Gene was cloned in Streptomyces aureofaciens through E. coli-Streptomyces shuttle plasmids constructed by both pIJ699-pUC19(vhb) and pIJ702-pBR322(vhb). Under low dissolved oxygen conditions, expression of hemoglobin enhanced CTC yield of engineering strain more about 40%-60% that that of control by improving oxygen transmission in cells. Hemoglobin expression by Promoter of tetracycline resistance gene was more effective for oxygen transmission than that by its native promoter regulated by dissolved oxygen concentrations in environments of locally low concentrations of dissolved oxygen.

Bacterial Proteins↗

PubMed2002

[Study on effect of Vitreoscilla hemoglobin gene expression on growth and metabolism of Streptomyces aureofaciens].

Vitreoscilla hemoglobin gene was expressed in S. aureofaciens through promoter of tetracycline resistance gene. Characteristics of S. aureofaciens growth and metabolism were studied in 1 m3 fermenter. In high dissolved oxygen concentrations, expression of hemoglobin gene had little effect on growth and metabolism of S. aureofaciens, and there were no obvious differences between engineering strain and control. The chlortetracycline of engineering strain was 22905 u/mL and of control was 22896 u/mL respectively. Under conditions of low dissolved oxygen, expression of hemoglobin enhanced growth, maintenance of energetic mycelium configuration and chlortetracycline yield of S. aureofaciens: the mycelium concentrations of engineering strain were more about 5%-10% and yield was more 11.4% than control.

Bacterial Proteins↗

PubMed2001

Expression of Human Angiostatin in Pichia pastoris and the Detection of Its Anti-angiogenic Activity.

Human angiostatin cDNA was amplified from human hepatoma cell line HepG2 using RT-PCR and was cloned into pPIC9K vector. Recombinant Pichia pastoris strain with 4 copies of angiostatin gene was obtained. Recombinant protein was purified by lysine-affinity Sepharose column and the finally purified angiostatin was 25 mg/L, higher than previously reported 17 mg/L. Amino acid sequence analysis revealed the identity of our protein the same with that previously reported. Recombinant angiostatin inhibited specifically the proliferation of bovine aortic endothelial cell stimulated by bFGF, with ED(50) being about 3 mg/L.

Journal Article↗