Glutamine Concentration (glutamine + concentration)

Distribution by Scientific Domains


Selected Abstracts


Effects of L-Asparaginase on Plasma Amino Acid Profiles and Tumor Burden in Cats with Lymphoma

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 4 2007
A.K. LeBlanc
Background: L-Asparaginase (Elspara), is an Escherichia coli -derived enzyme that depletes lymphoma cells of asparagine, inhibiting protein synthesis and resulting in cell death. The single agent response rate in cats with lymphoma and impact of L-asparaginase on plasma amino acid concentrations is unknown. Hypotheses: L-Asparaginase significantly reduces plasma asparagine concentrations and has demonstrable efficacy against untreated lymphoma in cats. Animals: Thirteen cats with confirmed lymphoma (LSA) of any anatomic site were given 1 dose 400 IU/kg IM) of L-asparaginase for initial LSA treatment. Methods: Plasma collected at 0, 2, and 7 days after L-asparaginase therapy was assayed for ammonia, asparagine, aspartic acid, glutamine, and glutamic acid concentrations. Cats were restaged 7 days later to assess tumor response. Results: Eight cats had T-cell LSA, 4 cats had B-cell LSA, and 1 cat's immunophenotype was unknown. Two complete and 2 partial responses to L-asparaginase were seen. Four cats had stable disease, and 5 cats had progressive disease. Ammonia and aspartic acid concentrations were increased from baseline at 2 and 7 days posttreatment. Asparagine concentrations were decreased from baseline at 2 days but not 7 days posttreatment. Glutamic acid concentrations were increased at day 2 compared to day 7 posttreatment but not compared to baseline. Glutamine concentrations were unchanged. Conclusions and Clinical Importance: L-Asparaginase significantly reduced asparagine concentrations within 2 days of treatment, but this effect was lost within 7 days. The apparent overall response rate of feline LSA to L-asparaginase in this study was 30%. [source]


Protein and oil concentration of soybean seed cultured in vitro using nutrient solutions of differing glutamine concentration

ANNALS OF APPLIED BIOLOGY, Issue 2 2004
ANTONIO E PIPOLO
Summary Oil and protein are the most valuable components of soybean seed. Evidence indicates that growth and composition of soybean seed are controlled by supplies of carbon and nitrogen provided by the maternal plant to the seed, but it is difficult experimentally to control and quantify the precise amount of carbon and nitrogen provided to the seed by the whole plant. To examine whether oil and protein concentrations are affected by the supply of nitrogen to the seed, immature soybean seeds (Glycine max cv. Williams 82) were grown in vitro in nutrient solutions containing 20, 40, 60 or 80 mM of glutamine. The seeds were incubated in Erlenmeyer flasks for 8 days at 25°C. The rate of dry matter accumulation changed from 7.2 to 8.3 mg seed,1 day,1 as the glutamine concentration increased from 20 to 80 mM but the differences were not significant (P 0.05). Seed protein concentration increased as glutamine concentration increased from 294 mg g,1 at 20 mM glutamine to as high as 445 mg g,1 at 80 mM glutamine. Typical in vivo protein concentration of mature soybean seeds is about 400 mg g,1. Oil and protein concentrations were negatively correlated (r2= 0.44), which indicates that oil and protein synthesis are interrelated. Protein synthesis was favoured over oil synthesis when nitrogen became more abundant. The seeds used in this study clearly demonstrated a capacity to respond to nitrogen availability with changes in seed protein concentration. [source]


Metabolism of PER.C6TM cells cultivated under fed-batch conditions at low glucose and glutamine levels

BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2006
Luis Maranga
Abstract This is the first study to examine PER.C6TM cell glucose/energy and glutamine metabolism with fed-batch cultures at controlled low glutamine, low glucose, and simultaneous low glucose and low glutamine levels. PER.C6TM cell metabolism was investigated in serum-free suspension bioreactors at two-liter scale. Control of glucose and/or glutamine concentrations had a significant effect on cellular metabolism leading to an increased efficiency of nutrient utilization, altered byproduct synthesis, while having no effect on cell growth rate. Cultivating cells at a controlled glutamine concentration of 0.25 mM reduced qGln and q by approximately 30%, qAla 85%, and qNEAA 50%. The fed-batch control of glutamine also reduced the overall accumulation of ammonium ion by approximately 50% by minimizing the spontaneous chemical degradation of glutamine. No major impact upon glucose/energy metabolism was observed. Cultivating cells at a glucose concentration of 0.5 mM reduced qGlc about 50% and eliminated lactate accumulation. Cells exhibited a fully oxidative metabolism with Y of approximately 6 mol/mol. However, despite no increase in qGln, an increased ammonium ion accumulation and Y were also observed. Effective control of lactate and ammonium ion accumulation by PER.C6TM cells was achieved using fed-batch with simultaneously controlled glucose and glutamine. A fully oxidative glucose metabolism and a complete elimination of lactate production were obtained. The qGln value was again reduced and, despite an increased q compared with batch culture, ammonium ion levels were typically lower than corresponding ones in batch cultures, and the accumulation of non-essential amino acids (NEAA) was reduced about 50%. In conclusion, this study shows that PER.C6TM cell metabolism can be confined to a state with improved efficiencies of nutrient utilization by cultivating cells in fed-batch at millimolar controlled levels of glucose and glutamine. In addition, PER.C6TM cells fall into a minority category of mammalian cell lines for which glutamine plays a minor role in energy metabolism. © 2006 Wiley Periodicals, Inc. [source]


Suspension Culture Process of MethA Tumor Cell for the Production of Heat-Shock Protein Glycoprotein 96: Process Optimization in Spinner Flasks

BIOTECHNOLOGY PROGRESS, Issue 6 2007
Ya-Jie Tang
Heat-shock proteins (HSPs) act like "chaperones", making sure that the cellapos;s proteins are in the right shape and in the right place at the right time. Heat-shock protein glycoprotein 96 (gp96) is a member of the HSP90 protein family, which chaperones a number of molecules in protein folding and transportation. Heat-shock protein gp96 serves as a natural adjuvant for chaperoning antigenic peptides into the immune surveillance pathways. Currently, heat-shock protein gp96 was only isolated from murine and human tissues and cell lines. An animal cell suspension culture process for the production of heat-shock protein gp96 by MethA tumor cell was developed for the first time in spinner flasks. Effects of culture medium and condition were studied to enhance the MethA tumor cell density and the production and productivity of heat-shock protein gp96. Initial glucose concentration had a significant effect on the heat-shock protein gp96 accumulation, and an initial glucose level of 7.0 g/L was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Cultures at an initial glutamine concentration of 3 and 6 mM were nutritionally limited by glutamine. At an initial glutamine concentration of 6 mM, the maximal viable cell density of 19.90 × 105 cells/mL and the maximal heat-shock protein gp96 production of 4.95 mg/L was obtained. The initial concentration of RPMI 1640 and serum greatly affected the MethA tumor cell culture process. Specifically cultures with lower initial concentration of RPMI 1640 resulted in lower viable cell density and lower heat-shock protein gp96 production. At an initial serum concentration of 8%, the maximal viable cell density of 19.18 × 105 cells/mL and the maximal heat-shock protein gp96 production of 5.67 mg/L was obtained. The spin rate significantly affected the cell culture process in spinner flasks, and a spin rate of 150 rpm was desirable for MethA tumor cell growth and heat-shock protein gp96 production and productivity. Not only the cell density but also the production and productivity of heat-shock protein gp96 attained in this work are the highest reported in the culture of MethA tumor cell. This work offers an effective approach for producing heat-shock protein glycoprotein 96 from the cell culture process. The fundamental information obtained in this study may be useful for the efficient production of heat-shock protein by animal cell suspension culture on a large scale. [source]


Metabolism of PER.C6TM cells cultivated under fed-batch conditions at low glucose and glutamine levels

BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2006
Luis Maranga
Abstract This is the first study to examine PER.C6TM cell glucose/energy and glutamine metabolism with fed-batch cultures at controlled low glutamine, low glucose, and simultaneous low glucose and low glutamine levels. PER.C6TM cell metabolism was investigated in serum-free suspension bioreactors at two-liter scale. Control of glucose and/or glutamine concentrations had a significant effect on cellular metabolism leading to an increased efficiency of nutrient utilization, altered byproduct synthesis, while having no effect on cell growth rate. Cultivating cells at a controlled glutamine concentration of 0.25 mM reduced qGln and q by approximately 30%, qAla 85%, and qNEAA 50%. The fed-batch control of glutamine also reduced the overall accumulation of ammonium ion by approximately 50% by minimizing the spontaneous chemical degradation of glutamine. No major impact upon glucose/energy metabolism was observed. Cultivating cells at a glucose concentration of 0.5 mM reduced qGlc about 50% and eliminated lactate accumulation. Cells exhibited a fully oxidative metabolism with Y of approximately 6 mol/mol. However, despite no increase in qGln, an increased ammonium ion accumulation and Y were also observed. Effective control of lactate and ammonium ion accumulation by PER.C6TM cells was achieved using fed-batch with simultaneously controlled glucose and glutamine. A fully oxidative glucose metabolism and a complete elimination of lactate production were obtained. The qGln value was again reduced and, despite an increased q compared with batch culture, ammonium ion levels were typically lower than corresponding ones in batch cultures, and the accumulation of non-essential amino acids (NEAA) was reduced about 50%. In conclusion, this study shows that PER.C6TM cell metabolism can be confined to a state with improved efficiencies of nutrient utilization by cultivating cells in fed-batch at millimolar controlled levels of glucose and glutamine. In addition, PER.C6TM cells fall into a minority category of mammalian cell lines for which glutamine plays a minor role in energy metabolism. © 2006 Wiley Periodicals, Inc. [source]