Wall regeneration by plasmolysed cells from tissue suspension cultures of Sphaerocarpos donnellii

1980 ◽  
Vol 43 (1) ◽  
pp. 167-175
Author(s):  
M.A. Grusak ◽  
R.J. Thomas ◽  
B.H. Marsh
Keyword(s):  
Liquid Scintillation ◽  
De Novo ◽  
Radioactive Tracer ◽  
Suspension Cultures ◽  
Cellulose Microfibrils ◽  
Wall Material ◽  
De Novo Synthesis ◽  
Tracer Techniques ◽  
Cross Linkage ◽  
Compositional Changes

De novo synthesis of wall material by cells of Sphaerocarpos donnellii was followed using radioactive tracer techniques. Uniform uptake of [14C]glucose by plasmolysed suspension cultures was demonstrated autoradiographically. Liquid scintillation counts of acid- or alkali-soluble wall carbohydrates indicate that hemicellulose and cellulose make up the major wall fractions in control and plasmolysed tissues. The amount of label in walls of plasmolysed cells was significantly lower than in those of controls. Higher relative radioactivity in pectin and hemicellulose, and lower radioactivity in cellulose were found in plasmolysed tissue. These compositional changes may enhance wall stability by providing numerous sites for cross-linkage between cellulose microfibrils of regenerated walls.

Lipoxygenase isoforms in elicitor-treated parsley cell suspension cultures

2000 ◽  
Vol 28 (6) ◽  
pp. 827-829 ◽  
Author(s):  
C. Noehringer ◽  
D. Scheel ◽  
E. Blée
Keyword(s):  
Jasmonic Acid ◽  
Cell Suspension ◽  
Cell Cultures ◽  
De Novo ◽  
Cell Suspension Cultures ◽  
Suspension Cultures ◽  
Defence Response ◽  
Fungal Elicitor ◽  
De Novo Synthesis

Treatment of parsley cell cultures with a fungal elicitor triggered the induction of a lipoxygenase isoform which may be involved in the de novo synthesis of defence-response inducers, such as jasmonic acid or 12-oxo-phytodienoic acid.

Study of the Radiometric Method and Use of the Liquid Scintillation Technique for Tool-Wear Determination

1965 ◽  
Vol 87 (1) ◽  
pp. 47-52 ◽  
Author(s):  
G. F. Wilson ◽  
W. Dennis McHenry
Keyword(s):  
Tool Wear ◽  
Liquid Scintillation ◽  
Radioactive Tracer ◽  
Radiometric Method ◽  
Primary Methods ◽  
Tracer Techniques ◽  
Wear Evaluation ◽  
Measuring Tool

A radiometric method of tool-wear evaluation was investigated and evaluated by comparing the results with those obtained from visual wear measurements. A liquid scintillation technique is presented for accurately determining tool wear for cutting limes as low as 0.003 min. It is recommended that the radioactive tracer techniques of measuring tool wear be used as supplemental methods in conjunction with visual wear determination procedures rather than primary methods of evaluating machining variables.

scholarly journals 103 Equine enterocytes actively oxidize L-glutamine but do not synthesize L-citrulline and L-arginine from L-glutamine or L-proline in vitro

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 90-91
Author(s):  
Rafael E Martinez ◽  
Jessica L Leatherwood ◽  
Amanda N Bradbery ◽  
Mattea L Much ◽  
Brittany L Silvers ◽  
...  
Keyword(s):  
Liquid Scintillation ◽  
De Novo ◽  
Scintillation Counter ◽  
Initial Step ◽  
Positive Control ◽  
Co2 Production ◽  
De Novo Synthesis ◽  
Bicarbonate Buffer ◽  
Dietary Requirements

Abstract In many mammals, enterocytes are responsible for the synthesis of L-citrulline and L-arginine from L-glutamine and L-proline. However, there is limited research in the horse to determine de novo synthesis of L-citrulline or L-arginine by the enterocyte, which is the initial step in establishing dietary requirements and comprehending arginine nutrition in horses. We utilized jejunal enterocytes from 20 horses (neonate n = 2, mature n = 16, and geriatric n = 2) to study glutamine and proline metabolism. As a positive control, enterocytes were isolated from 0, 60, and 180-day old pigs (n = 8/age group). Equine or porcine enterocytes were incubated at 37oC for 30 min in oxygenated (95% O2/5% CO2) Krebs bicarbonate buffer (pH 7.4) containing 5 mM D-glucose and either 2 mM L-[U-14C]glutamine or 2 mM L-[U-14C]proline plus 2 mM L-glutamine. Collected 14CO2 was determined by a liquid scintillation counter, whereas amino acids in cells plus medium were analyzed by HPLC. Both equine and porcine enterocytes oxidized glutamine to CO2 but had a limited ability to oxidize proline to CO2, confirming the biochemical viability of the cells in vitro. Enterocytes from neonatal and geriatric horses had lower rates (nmol/106 cells/30 min) of CO2 production (1.10 ± 0.52 and 1.31 ± 0.65, respectively) from glutamine than those (40.9 ± 5.40) from mature horses. Porcine enterocytes synthesized L-citrulline and L-arginine from glutamine and proline (e.g., 4.86 ± 0.26 nmol L-citrulline/mg protein/30 min and 0.85 ± 0.04 nmol L-arginine/mg protein/30 min from glutamine in enterocytes of 60-day-old pigs). In contrast, equine enterocytes did not synthesize L-citrulline and L-arginine from L-glutamine or L-proline. Because L-arginine is an essential substrate for the synthesis of protein, nitric oxide, and creatine, our novel findings on the lack of intestinal synthesis of L-arginine in horses have important implications for their nutrition, metabolism, and health.

Characterization of Monocyte-Associated Factor V

1993 ◽  
Vol 70 (02) ◽  
pp. 273-280 ◽  
Author(s):  
Janos Kappelmayer ◽  
Satya P Kunapuli ◽  
Edward G Wyshock ◽  
Robert W Colman
Keyword(s):  
Monoclonal Antibody ◽  
Light Chain ◽  
Peripheral Blood ◽  
De Novo ◽  
Factor V ◽  
Blood Monocytes ◽  
De Novo Synthesis ◽  
Hep G2 ◽  
Hep G2 Cells ◽  
Peripheral Blood Monocytes

SummaryWe demonstrate that in addition to possessing binding sites for intact factor V (FV), unstimulated peripheral blood monocytes also express activated factor V (FVa) on their surfaces. FVa was identified on the monocyte surface by monoclonal antibody B38 recognizing FVa light chain and by human oligoclonal antibodies H1 (to FVa light chain) and H2 (to FVa heavy chain) using immunofluorescence microscopy and flow cytometry. On Western blots, partially cleaved FV could be identified as a 220 kDa band in lysates of monocytes. In addition to surface expression of FVa, monocytes also contain intracellular FV as detected only after permeabilization by Triton X-100 by monoclonal antibody B10 directed specifically to the Cl domain not present in FVa. We sought to determine whether the presence of FV in peripheral blood monocytes is a result of de novo synthesis.Using in situ hybridization, no FV mRNA could be detected in monocytes, while in parallel control studies, factor V mRNA was detectable in Hep G2 cells and CD18 mRNA in monocytes. In addition, using reverse transcriptase and the polymerase chain reaction, no FV mRNA was detected in mononuclear cells or in U937 cells, but mRNA for factor V was present in Hep G2 cells using the same techniques. These data suggest that FV is present in human monocytes, presumably acquired by binding of plasma FV, and that the presence of this critical coagulation factor is not due to de novo synthesis.

Platelets Stimulate Thromboplastin Synthesis in Human Endothelial Cells

1983 ◽  
Vol 49 (02) ◽  
pp. 069-072 ◽  
Author(s):  
U L H Johnsen ◽  
T Lyberg ◽  
K S Galdal ◽  
H Prydz
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Umbilical Vein ◽  
Time Dependent ◽  
De Novo Synthesis ◽  
Human Endothelial Cells ◽  
Tumor Promotor ◽  
Coagulation Assay ◽  
Platelet Aggregates ◽  
Umbilical Vein Endothelial Cells

SummaryHuman umbilical vein endothelial cells in culture synthesize thromboplastin upon stimulation with phytohaemagglutinin (PHA) or the tumor promotor 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The thromboplastin activity is further strongly enhanced in a time dependent reaction by the presence of gel-filtered platelets or platelet aggregates. This effect was demonstrable at platelet concentrations lower than those normally found in plasma, it may thus be of pathophysiological relevance. The thromboplastin activity increased with increasing number of platelets added. Cycloheximide inhibited the increase, suggesting that de novo synthesis of the protein component of thromboplastin, apoprotein III, is necessary.When care was taken to remove monocytes no thromboplastin activity and no apoprotein HI antigen could be demonstrated in suspensions of gel-filtered platelets, platelets aggregated with thrombin or homogenized platelets when studied with a coagulation assay and an antibody neutralization technique.

DE NOVO SYNTHESIS OF STEROIDS BY THE TESTES OF THE HUMAN FOETUS AT MIDGESTATION

1971 ◽  
Vol 68 (1_Supplb) ◽  
pp. S135 ◽  
Author(s):  
R. S. Mathur ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
De Novo ◽  
De Novo Synthesis ◽  
Human Foetus
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