The effect of a Rhizoctonia solani phytotoxin on potatoes

1976 ◽  
Vol 54 (22) ◽  
pp. 2536-2540 ◽  
Author(s):  
J. A. Frank ◽  
S. K. Francis
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Rhizoctonia Solani ◽  
Liquid Culture ◽  
Phenylacetic Acid ◽  
Low Molecular Weight ◽  
Leaf Margin ◽  
Disease Symptoms ◽  
Low Concentrations ◽  
Root Necrosis

Rhizoctonia solani produces a nonenzymatic, low-molecular-weight phytotoxin in liquid culture. Many of the disease symptoms on potato attributed to this pathogen can be induced with this toxin. These include root necrosis and stolon pruning, leaf curling, stunting, and leaf margin chlorosis. In cases of extreme susceptibility, the plants could be killed within 1 week. The toxin has similar effects on radish, beet, and corn seedlings and acts as a growth hormone in low concentrations. A technique was designed to evaluate potato clones for their resistance to the root necrosis phase of the disease syndrome. With additional purification, the toxic fraction was identified as phenylacetic acid and its metahydroxylated derivative.

Reduction of Surfactant Retention in Limestones Using Sodium Hydroxide

SPE Journal ◽  
2018 ◽  
Vol 24 (01) ◽  
pp. 92-115 ◽  
Author(s):  
D.. Wang ◽  
M.. Maubert ◽  
G. A. Pope ◽  
P. J. Liyanage ◽  
S. H. Jang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Sodium Hydroxide ◽  
Anionic Surfactants ◽  
Geochemical Modeling ◽  
Low Molecular Weight ◽  
Low Concentrations ◽  
Reservoir Conditions ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Indiana Limestone

Summary Geochemical modeling was used to design and conduct a series of alkaline/surfactant/polymer (ASP) coreflood experiments to measure the surfactant retention in limestone cores using sodium hydroxide (NaOH) as the alkali. Surfactant/polymer (SP) coreflood experiments were conducted under the same conditions for comparison. NaOH has been used for ASP floods of sandstones, but these are the first experiments to test it for ASP floods of limestones. Two studies performed under different reservoir conditions showed that NaOH significantly reduced the surfactant retention in Indiana Limestone. An ASP solution with 0.3 wt% NaOH has a pH of approximately 12.6 at 25°C. The high pH increases the negative surface charge of the carbonate, which favors lower adsorption of anionic surfactants. Another advantage of NaOH is that low concentrations of only approximately 0.3 wt% can be used because of its low molecular weight and its low consumption in limestones. Most reservoir carbonates contain gypsum or anhydrite, and therefore sodium carbonate (Na2CO3) will be consumed by the precipitation of calcium carbonate (CaCO3). As shown in the two studies, NaOH can be used in limestone reservoirs containing gypsum or anhydrite.

Low concentrations of intravenous polygelines promote low-molecular weight proteinuria

2003 ◽  
Vol 33 (11) ◽  
pp. 962-968 ◽  
Author(s):  
B. A. J. Veldman ◽  
H. L. E. Schepkens ◽  
G. Vervoort ◽  
I. Klasen ◽  
J. F. M. Wetzels
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Low Molecular Weight Proteinuria ◽  
Low Concentrations

ChemInform Abstract: New Highly Potent Dipeptidic Growth Hormone Secretagogues with Low Molecular Weight.

ChemInform ◽  
2000 ◽  
Vol 31 (44) ◽  
pp. no-no
Author(s):  
Bernd Peschke ◽  
Michael Ankersen ◽  
Thomas Kruse Hanson ◽  
Birgit Sehested Hansen ◽  
Jesper Lau ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Low Molecular Weight ◽  
Growth Hormone Secretagogues

HIGH CONCENTRATIONS OF HEPARIN ARE MORE INHIBITORY TO PLATE- AGGREGATION IN-VITRO THAN ARE LOW MOLECULAR WEIGHT HEPARINS AND HEPARINOIDS AT THE SAME CONCENTRATION

1987 ◽  
Author(s):  
H Messmore ◽  
B Griffin ◽  
J Seghatchian ◽  
E Coyne
Keyword(s):  
Molecular Weight ◽  
Heparan Sulfate ◽  
Dermatan Sulfate ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Low Molecular Weight ◽  
Low Concentrations ◽  
High Concentrations ◽  
Induced Aggregation

Other investigators have shown that heparin in the usual therapeutic range (0.1-0.5 units/ml) has an enhancing effect on ADP aggregation and an inhibitory effect on collagen and thrombin induced aggregation. The effects of low molecular weight heparin (LMWH)and heparinoids (dermatan sulfate, heparan sulfate) on platelet aggregation have not been as extensivelystudied. We have utilized citrated platelet rich plasma (3.2%citrate-whole blood 1:9) drawn in plastic and adjusted to a final platelet count of 250,000/ul. A Bio-Data 4 channgl aggregometer was utilized with constantstirring at 37 C. The reaction was allowed to run for 20 minutes. Platelet rich plasma was supplemented 1:9 with saline or heparin and various agonists were then added ifno aggregation occurred. ADP, collagen, thrombin, ristocetin and serum from patients with heparin inudced thrombocytopenia (HIT) were utilized as agonists. Heparin was substituted at concentrations of 0.1 to 500 units per ml and various LMWH and heparinoids were substituted in equivalent anti-Xa or gravimetric concentrations. At low concentrations no inhibitory effect on any ofthe agonists was observed with any of the heparins or heparinoids. At concentrations of heparin of 100 u/ml or greater, all agonists were inhibited. At equivalent concentrations of five different LMWH (Cy 216, Cy 222, Pk 10169, Kabi 2165 and pentasaccharide) inhibition did notoccur at all or at very high concentions only. Dermatan sulfate and heparan sulfate inhibited only at high concentrations. HIT serum could not aggregate platelets with dermatan sulfate or pentasaccharide atany concentrations, but it was a good agonist with the other heparins and heparinoids.

scholarly journals Inhibition of adenosine triphosphatase, 5-hydroxytryptamine transport and proton-translocation activities of resealed chromaffin-granule ‘ghosts’

1980 ◽  
Vol 190 (2) ◽  
pp. 273-282 ◽  
Author(s):  
David K. Apps ◽  
James G. Pryde ◽  
Raul Sutton ◽  
John H. Phillips
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Proton Translocation ◽  
Low Molecular Weight ◽  
Chromaffin Granule ◽  
Low Concentrations ◽  
Tributyltin Chloride ◽  
Granule Membrane ◽  
Chromaffin Granule Ghosts

1. Highly purified resealed chromaffin-granule ‘ghosts’ were assayed for ATPase and ATP-driven H+-translocation and 5-hydroxytryptamine-uptake activities, and for 5-hydroxytryptamine uptake driven by an imposed transmembrane H+-gradient. The effects of several inhibitors on these activities were studied. 2. Dicyclohexylcarbodi-imide inhibits all of these activities, but not in parallel; at low concentrations it decreases the permeability of the membrane to protons. 3. 4-Chloro-7-nitrobenzofuran (Nbf-Cl) and silicotungstate inhibit ATP-dependent activities, without effect on 5-hydroxytryptamine uptake driven by an imposed H+-gradient. 4. Tributyltin chloride inhibits all of the activities. 5. Treatment of the ‘ghosts’ with low concentrations of urea inhibits 5-hydroxytryptamine uptake and ATP-dependent generation of a transmembrane H+-gradient, without inhibiting ATPase activity. 6. Nbf-Cl and silicotungstate are without effect on the rate of leakage of 5-hydroxytryptamine from preloaded ‘ghosts’, whereas dicyclohexylcarbodi-imide and tributyltin chloride accelerate the rate of leakage. 7. Treatment of the membranes with 14C-labelled Nbf-Cl labels several proteins; membranes treated with dicyclohexyl[14C]carbodi-imide are labelled predominantly in a protein of low molecular weight, which may be analogous to the mitochondrial H+-conducting proteolipid. 8. It is concluded that Nbf-Cl and silicotungstate inhibit the H+-translocating ATPase of the granule membrane; that dicyclohexylcarbodi-imide inhibits the ATPase, and inhibits 5-hydroxytryptamine accumulation by accelerating leakage of the amine; and that the effects of tributyltin chloride are due to inhibition of the ATPase, and collapse of the transmembrane H+-gradient through OH−-anion exchange.

Amino acids enhance renal tubular absorption of the los-molecular-weight proteins insulin and growth hormone

1982 ◽  
Vol 242 (6) ◽  
pp. F745-F749
Author(s):  
R. Rabkin ◽  
T. I. Gottheiner ◽  
T. S. Tsao
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Growth Hormone ◽  
Human Growth ◽  
Metabolic Effect ◽  
Low Molecular Weight ◽  
Insulin Absorption ◽  
Tubular Absorption ◽  
Renal Tubular ◽  
Isolated Rat

The effect of amino acids(AA) on the tubular absorption of low-molecular-weight (LMW) proteins was studied in isolated rat kidneys. Kidneys were perfused with an albumin-electrolyte solution that contained insulin or human growth hormone (hGH) and, unless otherwise stated, the following L-amino acids: glycine, isoleucine, serine, alanine, methionine, proline, arginine, and aspartic acid. In kidneys perfused without AA, fractional urinary insulin clearance (FCi) averaged 7.4 +/- 1.54%, whereas in the presence of multiple AA the FCi was significantly lower (0.68 +/- 0.2%, P less than 0.01). Addition of glycine or alpha-aminoisobutyric acid (AIB) alone also reduced the FCi significantly (1.79 +/- 0.66 and 1.59 +/-1.06%, respectively). By contrast, perfusion with the other AA individually did not alter the FCi. The fractional urinary hGH clearance was also significantly lower in kidneys perfused with multiple AA (0.94 +/- 0.47%) than in those perfused without AA (9.07 +/- 1.2%). We conclude that tubular absorption of filtered insulin and hGH is enhanced by the presence of AA. The mechanism is unclear, but enhancement of insulin absorption can be produced by glycine and AIB alone. This raises the possibility of a link between the absorption of insulin and the glycine and AIB shared transport system, but excludes a primary metabolic effect because AIB is nonmetabolizable.

Purification from Human Pregnancy Serum of a Low Molecular Weight Mitogen Similar to Placental Lactogen and Growth Hormone

1991 ◽  
Vol 197 (4) ◽  
pp. 441-449
Author(s):  
R. D. Kineman ◽  
E. E. Bullesbach ◽  
C. Schwabe ◽  
K. P. Boggs ◽  
L. S. Frawley
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Placental Lactogen ◽  
Low Molecular Weight ◽  
Human Pregnancy
Sign in / Sign up

Export Citation Format

Share Document