scholarly journals The biological effects of strontium (88Sr) on Chinese cabbage

2020 ◽  
Vol 66 (No. 4) ◽  
pp. 149-154
Author(s):  
Weirong Zhang ◽  
Zheng Kang ◽  
Qiang Wang ◽  
Nianwei Qiu ◽  
Min Chen ◽  
...  
Keyword(s):  
Steady State ◽  
Brassica Rapa ◽  
Chinese Cabbage ◽  
Nutritional Value ◽  
Photosynthetic Capacity ◽  
Biological Effects ◽  
Hydroponic Culture ◽  
Growth And Yield ◽  
Low Concentrations ◽  
High Concentrations

Steady-state strontium (<sup>88</sup>Sr) plays an important role in human health. Applying a proper amount of <sup>88</sup>Sr to vegetables can improve their nutritional value. To investigate the biological effects of <sup>88</sup>S on vegetables, three-leaf Chinese cabbage (Brassica rapa L.) seedlings were provided with a nutrient solution containing 0, 0.1, 0.2, 0.5, 1.0, 2.0, 5.0 and 10 mmol/L SrCl<sub>2</sub> by the hydroponic culture. The results showed that SrCl<sub>2</sub> at low concentrations (0.2 and 0.5 mmol/L) promoted the growth of Chinese cabbage, while SrCl<sub>2</sub> at high concentrations (2.0–10.0 mmol/L)significantly inhibited the growth. SrCl<sub>2</sub> at high concentrations did not decrease the chlorophyll content and protein content in Chinese cabbage leaves, nor did it affect the photosynthetic capacity of leaves. The main reason that SrCl<sub>2</sub> at high concentrations inhibited the growth of Chinese cabbage was that strontium affected the absorption of calcium. SrCl<sub>2</sub> at the concentration of 0.2 and 0.5 mmol/L could significantly increase leaf protein, chlorophyll, and water content and promote the growth of Chinese cabbage. The supplement of SrCl<sub>2</sub> at these two concentrations may be beneficial to the growth and yield of Chinese cabbage.

scholarly journals Steady-state kinetics of catecholamine transport by chromaffin-granule ‘ghosts’

1974 ◽  
Vol 144 (2) ◽  
pp. 319-325 ◽  
Author(s):  
J H Phillips
Keyword(s):  
Steady State ◽  
Competitive Inhibitor ◽  
Affinity Constant ◽  
Chromaffin Granule ◽  
Affinity Constants ◽  
Steady State Kinetics ◽  
Low Concentrations ◽  
High Concentrations ◽  
Chromaffin Granule Ghosts ◽  
Kinetics Of

Resealed chromaffin-granule ‘ghosts’ were used to study the steady-state kinetics of catecholamine transport. The pump has a high affinity for (-)-noradrenaline, (-)-adrenaline, tyramine and 5-hydroxytryptamine (serotonin), but a lower affinity for (+)-noradrenaline. The measured rates of incorporation do not conform to Michaelis–Menten kinetics, but affinity constants for the former substrates are in the range 8–18μm. Reserpine is a potent inhibitor. Incorporation as a function of ATP concentration also fails to show simple kinetics; the affinity constant for ATP is deduced to be about 3mm at 1mm-MgCl2. Adenylyl (βγ-methylene)diphosphonate is a competitive inhibitor at low concentrations, but inhibits more strongly at high concentrations. The pump has a transition temperature at 29°C and does not seem to be identical with the Mg2+-stimulated adenosine triphosphatase of chromaffin granules.

scholarly journals The effect of homoeopathic potencies of a fungicide, Acrobat (Dimethomorph and Mancozeb), on downy mildew (Peronospora parasitica) of cabbage seedlings (Brassica oleracea)

2000 ◽  
Author(s):  
◽  
Nicole Dawson
Keyword(s):  
Brassica Oleracea ◽  
Downy Mildew ◽  
Biological Effects ◽  
Growth Stimulation ◽  
Peronospora Parasitica ◽  
Inhibition Of Growth ◽  
Low Concentrations ◽  
High Concentrations

The purpose of this study was to expand on previous research in Homoeopathy, using the cabbage (Brassica oleracae) and crucifer downy mildew (Peronospora parasitica) disease system. More specifically, this study aimed to evaluate the biological effects of homoeopathic treatments made from a fungicide, Acrobat, on the development of downy mildew on cabbage seedlings. The object was to demonstrate the Arndt-Schulz Law or Hormesis (inhibition of growth at high concentrations and growth stimulation at low concentrations) using homoeopathic treatments prepared as per homoeopathic methodology, by dilution and succussion.

Bioaccummulation of the endocrine disrupting compound, dioctyl phthalate, in sheep grazing pasture treated with sewage sludge or inorganic fertiliser

2001 ◽  
Vol 2001 ◽  
pp. 67-67
Author(s):  
S.M. Rhind ◽  
C.E. Kyle ◽  
G. Telfer ◽  
G. Martin ◽  
A. Smith
Keyword(s):  
Sewage Sludge ◽  
Biological Effects ◽  
Arable Land ◽  
Endocrine Disrupting Compounds ◽  
Dioctyl Phthalate ◽  
Animal Tissues ◽  
Endocrine Disrupting Compound ◽  
Low Concentrations ◽  
Endocrine Disrupting ◽  
High Concentrations

Endocrine disrupting compounds (EDC) are chemically diverse and ubiquitous compounds which are released into the environment as a result of industrial, domestic and agricultural processes. They are generally readily absorbed from ingested food and water, can accumulate in animal tissue and can have adverse effects on reproductive and immune systems at very low concentrations. They are present in high concentrations in sewage sludge which is likely to be used increasingly as a fertiliser on pasture and arable land and so there is potential for bioaccumulation in animal tissues and associated, adverse biological effects. The aim of the study was to determine the concentrations of one EDC, dioctyl phthalate (DOP), in the livers of ewes and lambs maintained on control and sludge-treated pastures.

scholarly journals Kinetic properties of highly purified preparations of sheep liver cytoplasmic aldehyde dehydrogenase

1982 ◽  
Vol 203 (3) ◽  
pp. 617-627 ◽  
Author(s):  
G J Hart ◽  
F M Dickinson
Keyword(s):  
Steady State ◽  
Aldehyde Dehydrogenase ◽  
Kinetic Properties ◽  
Stopped Flow ◽  
Flow Measurements ◽  
Sheep Liver ◽  
Low Concentrations ◽  
Mechanism Of Reaction ◽  
High Concentrations ◽  
Variable Substrate

The kinetic properties of highly purified preparations of sheep liver cytoplasmic aldehyde dehydrogenase (preparations that had been shown to be free from contamination with the corresponding mitochondrial enzyme) were investigated with both propionaldehyde and butyraldehyde as substrates. At low aldehyde concentrations, double-reciprocal plots with aldehyde as the variable substrate are linear, and the mechanism appears to be ordered, with NAD+ as the first substrate to bind. Stopped-flow experiments following absorbance and fluorescence changes show bursts of NADH production in the pre-steady state, but the observed course of reaction depends on the pre-mixing conditions. Pre-mixing enzyme with NAD+ activates the enzyme in the pre-steady state and we suggest that the reaction mechanism may involve isomeric enzyme-NAD+ complexes. High concentrations of aldehyde in steady-state experiments produce significant activation (about 3-fold) at high concentrations of NAD+, but inhibition at low concentrations of NAD+. Such behaviour may be explained by postulating the participation of an abortive complex in product release. Stopped-flow measurements at high aldehyde concentrations indicate that the mechanism of reaction under these conditions is complex.

Neutrophil Elastase Potentiates Cathepsin G-lnduced Platelet Activation

1992 ◽  
Vol 68 (05) ◽  
pp. 570-576 ◽  
Author(s):  
Mary A Selak
Keyword(s):  
Neutrophil Elastase ◽  
Cell Activation ◽  
Thromboxane A2 ◽  
Creatine Phosphate ◽  
Dense Granule ◽  
Cathepsin G ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Low Concentrations ◽  
High Concentrations

SummaryWe have previously demonstrated that human neutrophil cathepsin G is a strong platelet agonist that binds to a specific receptor. This work describes the effect of neutrophil elastase on cathepsin G-induced platelet responses. While platelets were not activated by high concentrations of neutrophil elastase by itself, elastase enhanced aggregation, secretion and calcium mobilization induced by low concentrations of cathepsin G. Platelet aggregation and secretion were potentiated in a concentration-dependent manner by neutrophil elastase with maximal responses observable at 200 nM. Enhancement was observed when elastase was preincubated with platelets for time intervals of 10–60 s prior to addition of a low concentration of cathepsin G and required catalytically-active elastase since phenylmethanesulphonyl fluoride-inhibited enzyme failed to potentiate cell activation. Neutrophil elastase potentiation of platelet responses induced by low concentrations of cathepsin G was markedly inhibited by creatine phosphate/creatine phosphokinase and/or indomethacin, indicating that the synergism between elastase and cathepsin G required the participation of ADP and thromboxane A2. On the other hand, platelet responses were not attenuated by the PAF antagonist BN 52021, signifying that PAF-acether did not play a role in elastase potentiation. At higher concentrations porcine pancreatic elastase exhibits similar effects to neutrophil elastase, demonstrating that the effect of elastase was not unique to the neutrophil protease. While neutrophil elastase failed to alter the ability of cathepsin G to hydrolyze a synthetic chromogenic substrate, preincubation of platelets with elastase increased the apparent affinity of cathepsin G binding to platelets. In contrast to their effect on cathepsin G-induced platelet responses, neither neutrophil nor pancreatic elasatse potentiated aggregation or dense granule release initiated by ADP, PAF-acether, arachidonic acid or U46619, a thromboxane A2 mimetic. Moreover, unlike its effect on cathepsin G, neutrophil elastase inhibited thrombin-induced responses. The current observations demonstrate that elastase can potentiate platelet responses mediated by low concentrations of cathepsin G, suggesting that both enzymes may function synergistically to activate platelets under conditions where neutrophil degranulation occurs.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Aggregation of Cat Platelets in Vitro

1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp
Keyword(s):  
Adenosine Monophosphate ◽  
Blood Collection ◽  
Base Line ◽  
Reversible Aggregation ◽  
Low Concentrations ◽  
Irreversible Aggregation ◽  
High Concentrations ◽  
Two Phases ◽  
Improved Technique

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.

The Action of an Aniline Derivative (AN 162) on Blood Coagulation and on Platelets

1971 ◽  
Vol 26 (01) ◽  
pp. 145-166
Author(s):  
E Deutsch ◽  
K Lechner ◽  
K Moser ◽  
L Stockinger
Keyword(s):  
Blood Coagulation ◽  
Citric Acid Cycle ◽  
Second Phase ◽  
Aniline Derivative ◽  
Acid Cycle ◽  
Enhancing Effect ◽  
Low Concentrations ◽  
Dual Action ◽  
High Concentrations ◽  
Induced Aggregation

Summary1. The aniline derivative AN 162, Donau Pharmazie, Linz, Austria, has a dual action on the blood coagulation: an anticoagulant and an coagulation enhancing effect.2. The anticoagulant action may only be demonstrated with high concentrations (over 1 X 10”3 M related to plasma) preferentially in PPP. It is partially caused by an inhibition of the endogenous way of generation of the prothrombin converting principle. In addition it is suggested that it interferes with the fibrinogen-fibrin reaction in a manner not yet understood.3. The coagulant action is caused by a greater availability of platelet constituents at low concentrations of AN 162 (over 1 × 10-4 M) and by the induction of a release reaction at higher concentrations. The platelet factors 3 and 4, serotonin, adenine, and acid phosphatase are released.4. AN 162 inhibits platelet aggregation. This inhibition can be demonstrated by the PAT of Breddin and in the stirred aggregation test of Born. It is more effective to inhibit the collagen-induced and the second phase of the adrenaline-induced aggregation than the ADP induced one. The platelet retention (test of Hellem) is also reduced.5. The action of AN 162 on the platelets is caused by a damage of the platelet membrane which becomes permeabel for both, soluble platelet constitutents and granula.6. AN 162 interferes with the energy metabolism of the platelets. It causes a loss of ATP, and inhibits the key-enzymes of glycolysis, citric acid cycle, fatty acid oxydation and glutathione reduction.7. AN 162 inhibits the growth of fibroblasts without influence on mitosis.

Functional Involvement of Thrombospondin in Platelet Aggregation Induced by Low Versus High Concentrations of Thrombin

1986 ◽  
Vol 55 (01) ◽  
pp. 136-142 ◽  
Author(s):  
K J Kao ◽  
David M Shaut ◽  
Paul A Klein
Keyword(s):  
Platelet Aggregation ◽  
Binding Sites ◽  
Inhibitory Effect ◽  
Activated Platelets ◽  
Low Concentrations ◽  
Platelet Binding ◽  
Functional Involvement ◽  
Thrombin Activation ◽  
Platelet Aggregates ◽  
High Concentrations

SummaryThrombospondin (TSP) is a major platelet secretory glycoprotein. Earlier studies of various investigators demonstrated that TSP is the endogenous platelet lectin and is responsible for the hemagglutinating activity expressed on formaldehyde-fixed thrombin-treated platelets. The direct effect of highly purified TSP on thrombin-induced platelet aggregation was studied. It was observed that aggregation of gel-filtered platelets induced by low concentrations of thrombin (≤0.05 U/ml) was progressively inhibited by increasing concentrations of exogenous TSP (≥60 μg/ml). However, inhibition of platelet aggregation by TSP was not observed when higher than 0.1 U/ml thrombin was used to activate platelets. To exclude the possibility that TSP inhibits platelet aggregation by affecting thrombin activation of platelets, three different approaches were utilized. First, by using a chromogenic substrate assay it was shown that TSP does not inhibit the proteolytic activity of thrombin. Second, thromboxane B2 synthesis by thrombin-stimulated platelets was not affected by exogenous TSP. Finally, electron microscopy of thrombin-induced platelet aggregates showed that platelets were activated by thrombin regardless of the presence or absence of exogenous TSP. The results indicate that high concentrations of exogenous TSP (≥60 μg/ml) directly interfere with interplatelet recognition among thrombin-activated platelets. This inhibitory effect of TSP can be neutralized by anti-TSP Fab. In addition, anti-TSP Fab directly inhibits platelet aggregation induced by a low (0.02 U/ml) but not by a high (0.1 U/ml) concentration of thrombin. In conclusion, our findings demonstrate that TSP is functionally important for platelet aggregation induced by low (≤0.05 U/ml) but not high (≥0.1 U/ml) concentrations of thrombin. High concentrations of exogenous TSP may univalently saturate all its platelet binding sites consequently interfering with TSP-crosslinking of thrombin-activated platelets.

PENGARUH KOMPOS SAMPAH KOTA DAN PUPUK KANDANG SAPI TERHADAP PERTUMBUHAN DAN HASIL TANAMAN PAKCOY (BRASSICA RAPA, L. CHINENSIS) PADA ALUVIAL KABUPATEN INDRAMAYU

2018 ◽  
Vol 9 (2) ◽  
pp. 153-163
Author(s):  
Wiwik Ambarsari ◽  
Henly Yuliana
Keyword(s):  
Plant Height ◽  
Brassica Rapa ◽  
Block Design ◽  
Cattle Manure ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Two Factors ◽  
Number Of Leaves ◽  
Experimental Garden

The study aimed to determine the effect of the combination of city waste compost and cattle manure on the growth and yield of pakcoy plants (Brassica rapa, L. Chinensis) in Aluvial, Indramayu Regency. The study was conducted at the Experimental Garden of the Faculty of Agriculture, Wiralodra University, Indramayu Regency from March to August 2018. This study used Factorial Pattern Randomized Block Design with two factors. The first factor is city waste compost and the second factor is cattle manure with 4 levels: 0%, 3.0%, 6.0%, and 9.0%, repeated twice. The results showed that there was an independent influence between city waste compost and cattle manure on plant height and number of leaves. The best combination to increase the feasibility weight of pakcoy consumption is by giving city waste compost 9.0% (S4) and cattle manure 6.0% (K3).

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