Respiratory Responses of Pea and Wheat Seedlings to Chloramphenicol Treatment

1996 ◽  
Vol 23 (5) ◽  
pp. 583 ◽  
Author(s):  
Qisen Zhang ◽  
L Mischis ◽  
JT Wiskich
Keyword(s):  
Molecular Weight ◽  
Nadh Dehydrogenase ◽  
Alternative Oxidase ◽  
Fold Increase ◽  
Complete Loss ◽  
Wheat Seedlings ◽  
Pea Seedlings ◽  
Wheat Leaf ◽  
Respiratory Responses ◽  
Cyanide Resistant Respiration

A common feature in responding to chloramphenicol treatment for pea and wheat seedlings was the substantial increases in the rates of cyanide-resistant respiration. However, they were very different in many other aspects. Whole pea leaves appeared yellowish 3 or more days after chloramphenicol treatment. The chlorophyll content decreased by 30% after 9-10 days. In wheat seedlings, chloramphenicol treatment resulted in a complete loss of chlorophyll and formation of white tissues in the base of their leaves. The top region of leaves was still green. The un-inhibited rates of respiration decreased in pea, but increased in wheat mitochondria oxidising NADH. There was an approximately 5-fold increase in the activity of externally facing NADH dehydrogenase in wheat, but not in pea mitochondria. Western blot analysis showed that there were two additional bands of lower molecular weight alternative oxidases (32-33 kDa) in chloramphenicol-treated wheat leaf mitochondria, but there was no increase in alternative oxidase proteins in chloramphenicol-treated pea leaf and root mitochondria. Wheat seedlings responded to chlorarnphenicol treatment presumably by increasing the rate of glycolysis, while pea seedlings may have a different mechanism.

Cereals frost resistance correlates with an integral indicators of content of low-molecular-weight protective compounds and activity of antioxidant enzymes

2020 ◽  
Vol 2020 (3) ◽  
pp. 71-86
Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Antioxidant System ◽  
Frost Resistance ◽  
Low Molecular Weight ◽  
Guaiacol Peroxidase ◽  
Wheat Seedlings ◽  
Enzymatic Antioxidant ◽  
Adult Plants

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.

Thrombosis and embolism in pregnancy

2020 ◽  
pp. 206-212
Author(s):  
Ian A. Greer
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Objective Assessment ◽  
Fold Increase ◽  
Low Molecular Weight ◽  
Thoracic Imaging ◽  
Mortality And Morbidity ◽  
First Choice ◽  
Daily Risk ◽  
In Pregnancy

Venous thromboembolism (VTE) is a leading cause of maternal mortality and morbidity. Prophylaxis and management of VTE in pregnancy can impact mortality and morbidity. The overall reported incidence of gestational VTE ranges from 0.5 to 2.2 per 1000 maternities with a relative 5–10-fold increase in risk during pregnancy, increasing to a daily risk of 15–35-fold in the puerperium, compared with non-pregnant women of similar age. Risk factors inform the use of thromboprophylaxis usually with low-molecular-weight heparin, which has a better safety profile than unfractionated heparin. VTE can occur at any time in pregnancy, but over 50% of events occur prior to 20 weeks’ gestation. As clinical diagnosis is unreliable, objective assessment is required when there is clinical suspicion of an event. Less than 10% of clinically suspected cases of VTE are confirmed on objective testing. Compression duplex ultrasonography is the first-line investigation for suspected gestational deep venous thrombosis and thoracic imaging with ventilation–perfusion scanning is required for suspected pulmonary embolism. Low-molecular-weight heparin is usually the first choice treatment for gestational VTE based on safety and efficacy.

Platelet adhesion by Subendothelium-Bound Factor VIII-VWF:Kinetics and Molecular Weight Dependence

1979 ◽  
Author(s):  
P. A. Bolhuis ◽  
K. S. Sakariassen ◽  
J. J. Sixma
Keyword(s):  
Molecular Weight ◽  
Platelet Adhesion ◽  
Fold Increase ◽  
Surface Concentration ◽  
Albumin Solution ◽  
Molecular Weight Dependence ◽  
High Molecular Weight Component ◽  
Von Willebrand ◽  
Kinetics Of

Platelet adhesion to human subendothelium was determined by perfusions with albumin solutions containing 51Cr-labeled, aspirin-treated platelets and washed red cells (hematocrit 40%) at 37° and a flow rate of 135 ml/min. Adherence was similar with Von Willebrand plasma instead of albumin solution and addition of purified FVIII-VWF caused adhesion similar to that from normal plasma. Incubation of subendotheliurn with FVIII-VWF resulted of binding of FVIII-VWF at the surface and in subsequent perfusions a surface concentration of, FVII-VWF/cm2 was shown to correct the platelet adhesion in albumin solutions towards normal. The kinetics of binding of FVIII-VWF and platelets to the subendothelium confirm the role of bound FVIII-VWF in adhesion. Binding of FVII-VWF occurs rapidly in the first minute of perfusion to about 4 x 10-4U/cm2 and then increases further to about 10-3 u/cm2 in 5 min. Platelet adhesion is similar for perfusates with and without FVIII-WF in the first minute; then the presence of FVIII-VWF results in a two-fold increase of adhesion at 5 min. Reduced adhesion was found with the high-molecular weight component of FVIII-VWF obtained by high iconic strength dissociation. Also, the activity of glycin precipitated FVIII-VWF (e.g. Hemofil FVIII-concentrate) is impaired, cross-electrophoresis of FVIII-VWF from cryoprecipitate and FVIII-VWF after glycin precipitation showed an increased mobility or the latter, indicating a reduced molecular siie. From these experiments we conclude tnat platelet adhesion is mediated by subendothelium-bound FVIII-WWF. The degree of adhesion may depend on the molecular weight of the FVIII-VWF.

Effects of Cadmium Stress on Alternative Oxidase and Photosystem II in Three Wheat Cultivars

2010 ◽  
Vol 65 (1-2) ◽  
pp. 87-94 ◽  
Author(s):  
Yong-Ping Duan ◽  
Shu Yuan ◽  
Shi-Hua Tu ◽  
Wen-Qiang Feng ◽  
Fei Xu ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Alternative Oxidase ◽  
Thiobarbituric Acid ◽  
Cadmium Stress ◽  
Wheat Cultivars ◽  
Cd Stress ◽  
Western Blots ◽  
Chlorophyll Contents ◽  
Water Contents ◽  
Cyanide Resistant Respiration

The effects of Cd stress (200 μmol/L, 8 days) on respiration and photosynthesis of three wheat cultivars were investigated: Chuanyu 12 (CY12), Chuanmai 42 (CM42), and Chuanmai 47 (CM47). Fifteen-day-old seedlings were exposed to 200 μmol/L CdCl2 for 4 days and 8 days, respectively. The results indicated that Cd was accumulated largely in roots, but little in leaves of all three cultivars. CY12 accumulated the highest level of Cd in roots and showed the weakest resistance. On the contrary, the other two cultivars, CM42 and CM47, adapted better to Cd stress, and their thiobarbituric acid-reactive substances (TBARS) contents were lower than in CY12, but the chlorophyll contents and water contents were higher than in CY12. Additionally, Cd stress prompted the alternative oxidase (AOX) activity and upregulated the cyanide-resistant respiration in CM42 and CM47 after 8 days; no such induction was observed for CY12. The CO2 assimilation rate, leaf stomatal conductance and chlorophyll fl uorescence were inhibited by Cd stress in all cultivars, but more severe in the CY12 cultivar. Western blots indicated that the content of the photosystem II proteins LHCII and D1 decreased in CY12, but did not change in CM42 and CM47. While the content of the mitochondrial AOX protein increased markedly in CM42 and CM47, it did not in CY12. These results suggested that AOX and LHCII could be regarded as indicators of plant’s resistance to heavy metals.

Dissociation Reassociation and Phenylalanine Incorporation by Chloroplast and Cytoplasmic Wheat-Leaf Ribosomes

1973 ◽  
Vol 51 (5) ◽  
pp. 686-693 ◽  
Author(s):  
Berne L. Jones ◽  
N. Nagabhushan ◽  
Edward B. Tucker ◽  
Saul Zalik
Keyword(s):  
Wheat Seedlings ◽  
Wheat Leaf ◽  
Zonal Separation

Ribosome preparations from wheat seedlings were separated by zonal centrifugation to yield monomers of 80 S (cytoplasmic) and 70 S (chloroplast). When centrifuged through gradients containing high KCl-to-MgCl2 buffer, the 80 S ribosomes dissociated into subunits of 61 S, 49 S, and 42 S, while the 70 S monomers gave subunits of 50 S and 30 S. After zonal separation of the subunits, they could be reassociated into parent ribosomes in the presence of MgCl2. Both 80 S and 70 S ribosomes actively synthesized polyphenylalanine in the presence of poly U. The rate of synthesis was similar for both species. Incorporation of phenylalanine by 80 S and 70 S ribosomes was inhibited by puromycin, was not inhibited by cycloheximide, and only the 70 S species was affected by chloramphenicol, indicating that the latter was of chloroplast origin.

Antithrombin ‘DREUX’ (Lys114Glu): A Variant with Complete Loss of Heparin Affinity

2002 ◽  
Vol 88 (09) ◽  
pp. 436-443 ◽  
Author(s):  
James Huntington ◽  
Jacqueline Conard ◽  
Robin Carrell ◽  
Alec Mushunje ◽  
Aiwu Zhou
Keyword(s):  
Factor Xa ◽  
Fold Increase ◽  
Complete Loss ◽  
Factor X ◽  
Heparin Binding ◽  
High Affinity ◽  
The Core ◽  
Factor Xa Inhibition ◽  
Heparin Affinity ◽  
Father And Son

SummaryHere we report the finding of a new natural antithrombin mutation that confirms the critical contribution of lysine 114 to the binding of the core heparin pentasaccharide, with the replacement of lysine 114 by glutamate causing a complete loss in affinity. The variant was identified in a father and son, the father having been investigated for an episode of cerebral ischaemia associated with hypercholesterolaemia. The variant forms SDS-stable complexes with activated factor X (fXa) and its thermal stability and rate of factor Xa inhibition in the absence of heparin are identical to those of normal antithrombin. Normal antithrombin binds to the high affinity heparin pentasaccharide with a Kd of 1nM, as detected by a 45% change in intrinsic fluorescence, resulting in a 230-fold increase in rate of factor Xa inhibition. However, no change in fluorescence was detected for the variant when titrated with heparin or the heparin pentasaccharide, nor was there detectable activation towards factor Xa, indicating a complete loss of heparin binding.

Pharmacodynamic Differences of An Anti-Xa Enriched Low Molecular Weight Heparin, AVE 5026 in Comparison to Enoxaparin and Unfractionated Heparin.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4171-4171
Author(s):  
Debra Hoppensteadt ◽  
Angel Gray ◽  
Evangelos Litinas ◽  
Brigitte Kaiser ◽  
Jawed Fareed
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Half Life ◽  
Low Molecular Weight Heparin ◽  
Thrombin Generation ◽  
Time Course ◽  
Fold Increase ◽  
Low Molecular Weight ◽  
Thrombin Time ◽  
Primate Model

Abstract Abstract 4171 AVE5026 (Sanofi-Aventis, Paris, France) represents an anti-Factor (F) Xa enriched ultra low molecular weight heparin (ULMWH) (Mw=2.4 Kda; anti-FXa activity ∼160 U/mg). In comparison to Enoxaparin it has a lower anti-FIIa activity (∼2 U/mg). The oligosaccharide composition of AVE5026 also differs from Enoxaparin and other LMWHs. Besides the molecular and compositional differences, the biologic half-life of AVE5026 (18-20 hours) is significantly longer than Enoxaparin (4-6 hours). In order to compare the other pharmacodynamic differences between AVE5026, Enoxaparin and unfractionated heparin (UFH), a primate model (macaca mulatto) was used since its tissue factor pathway inhibitor (TFPI) profile is comparable to the human response. Individual groups of primates (n=6) were administered with 1 mg/kg SC of either AVE5026, Enoxaparin or UFH. Heptest and APTT measurements were determined on whole blood (WB) and plasma was analyzed for APTT, Heptest, thrombin time (TT), anti-FXa and anti-FIIa effects at varying periods up to 28 hours. TFPI antigen was measured using the assay from Stago (Parsipanny, NJ). Functional TFPI measurements were determined using the kit from American Diagnostica (Stamford, CT). In contrast to UFH, in the WB assays, neither the AVE5026 nor the Enoxaparin produced a strong effect on the APTT and TT, however both demonstrated a strong effect on the heptest assay. AVE5026 produced a much stronger effect with a longer half-life (T½=11 hrs) in comparison to Enoxaparin (T½=6 hrs). In the plasma based systems only UFH produced a measurable effect on the APTT and TT. However, in the heptest and anti-FXa assays, both AVE5026 and Enoxaparin produced a stronger effect, which was much longer with AVE5026 (2-3 fold increase). The plasma time course of TFPI antigen release was longer with AVE5026 in comparison to Enoxaparin and UFH. The ratios of immunologic to functional TFPI levels were also higher in the primates administered with AVE 5026. In the thrombin generation test, AVE5026 produced a sustained effect which lasted longer than Enoxaparin (T½ =16.8 hrs vs. 9.2 hrs.). These results show that AVE5026 produces stronger anti-FXa effects in primates which are associated with a higher circulating level of TFPI and more pronounced suppression of thrombin generation compared to Enoxaparin and UFH. Disclosures: Hoppensteadt: Sanofi-Aventis: Research Funding.

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