HES 200/0.5 Is not HES 200/0.5

1995 ◽  
Vol 74 (06) ◽  
pp. 1452-1456 ◽  
Author(s):  
Johannes Treib ◽  
Anton Haass ◽  
Gerhard Pindur ◽  
Ulrich T Seyfert ◽  
Wolfgang Treib ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyethyl Starch ◽  
Clinical Relevance ◽  
Dilution Effect ◽  
Repeated Administration ◽  
Plasma Viscosity ◽  
Degree Of Substitution ◽  
Pronounced Increase ◽  
Large Molecules ◽  
Mean Molecular Weight

SummaryThe plasma clearance of hydroxyethyl starch (HES) depends on the initial molecular weight and the degree of substitution. So far, little attention has been paid to the clinical relevance of the C2/C6 substitution ratio of hydroxyethyl starch.10 patients with cerebrovascular circulatory disturbance received hemodilution therapy for 10 days, consisting of 10% HES 200/0.5 (mean molecular weight 200 kD, degree of substitution 0.5) with a C2/C6 ratio of 13.4. A second group of 10 patients received a starch solution with identical initial molecular weight and degree of substitution but with a C2/C6 ratio of 5.7.After the administration of a single dose, no significant differences between the two groups were observed. After repeated administration, significant differences could be detected in hemorheology, coagulation and elimination (p<0.01). The larger C2/C6 ratio led to a higher intravascular mean molecular weight (95 vs. 84 kD), which in turn led to a higher increase in serum concentration during the therapy (14.7 vs.8.6 mg/ml). Hematocrit was lowered more (-30,5 vs. -23,5%) and plasma viscosity was increased more. There was also a more pronounced increase in partial thromboplastin time (+30% vs. +13%) and a factor of 2 larger decrease of factor VIII/von Willebrand factor-complex (p <0.01), which exceeded the dilution effect.The higher C2/C6 ratio of HES 200/0.5/13.4 slows down enzymatic degradation. After repeated administration of this starch, large molecules accumulate which are inefficiently degraded. The same effect has been observed after therapy with highly-substituted HES. This accumulation of large molecules leads to a beneficial longer lasting volume effect. The disadvantages include an increase in plasma viscosity and coagulation disturbances, which cannot be explained with the respective dilution effect alone. For these reasons, the C2/C6 ratio is of clinical relevance and should be included in the product labeling in the future.

Hydroxyethyl Starch: The Effect of Molecular Weight and Degree of Substitution on Intravascular Retention In Vivo

2007 ◽  
Vol 105 (3) ◽  
pp. 724-728 ◽  
Author(s):  
Takashi Hitosugi ◽  
Toshiyuki Saito ◽  
Sono Suzuki ◽  
Ieko Kubota ◽  
Emi Shoda ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyethyl Starch ◽  
Degree Of Substitution

Disruptive effects of protein on performance of liquid membrane-based ion-selective microelectrodes

1994 ◽  
Vol 267 (4) ◽  
pp. C1027-C1035 ◽  
Author(s):  
H. V. Coombs ◽  
A. J. Miller ◽  
D. Sanders
Keyword(s):  
Molecular Weight ◽  
Detection Limit ◽  
Liquid Membrane ◽  
Detection Limits ◽  
Biological Macromolecules ◽  
Pronounced Increase ◽  
Large Molecules ◽  
Ion Concentrations ◽  
Earth Cation ◽  
Protein Bovine Serum Albumin

The effects of addition of protein [bovine serum albumin (BSA)] to the calibration solutions of various liquid membrane-based ion-selective microelectrodes have been assessed. Protein at typically cytosolic levels of 100 mg/ml had no effect on the response of Na(+)-, K(+)-, Mg(2+)-, Ca(2+)-, H(+)-, NO3(-)-, and Cl(-)- selective microelectrodes at ion concentrations well above the respective detection limits. By contrast, this level of protein resulted in a pronounced increase in the detection limits of Na(+)-, K(+)-, Mg(2+)-, Ca2+, and Cl(-)-selective microelectrodes; H+ and NO3- microelectrodes were largely unaffected by the protein. The effect of BSA on detection limit is independent of pH and ionic strength, nor is it due to hysteresis, to binding of ions to the protein, or to the generation of junction potentials. More extensive studies on Na(+)-selective microelectrodes revealed that other proteins and large molecules (e.g., polyethylene glycol) also increase detection limits, with the extent of this effect apparently correlated positively with the molecular weight. Because biological macromolecules at physiological concentrations can influence the properties of alkali- and alkali earth cation-selective microelectrodes, care must be taken if the use of these electrodes entails cytosolic measurements close to their detection limits.

Suppressive Effect of Dextran on Platelet Adhesiveness

1966 ◽  
Vol 16 (03/04) ◽  
pp. 384-394 ◽  
Author(s):  
S Cronberg ◽  
B Robertson ◽  
Inga Marie Nilsson ◽  
J.-E Niléhn
Keyword(s):  
Molecular Weight ◽  
Bleeding Time ◽  
Slight Modification ◽  
Molecular Size ◽  
Suppressive Effect ◽  
Factor Ix ◽  
Factor V ◽  
Platelet Adhesiveness ◽  
History Of ◽  
Mean Molecular Weight

Summary43 normal volunteers, 3 patients with thrombophlebitis, and 1 patient with a high platelet adhesiveness and a history of thrombophlebitis have received dextran and its action on the mechanism of haemostasis has been studied. Platelet adhesiveness has been investigated by a slight modification of Hellem’s methods for whole blood and plasma. Dextran with a mean molecular weight of 70,000 produced a markedly lowered platelet adhesiveness together with a moderate prolongation of the Ivy bleeding time. Factor VIII was decreased by about 50% and factor V, factor IX and fibrinogen were decreased slightly more than could be expected from haemodilution alone. No fibrinolysis occurred. Dextran of lower molecular size was less potent. The possible use of dextrans as a thrombosis prophylactic agent is discussed.

STUDIES ON THE ANTITHROMBOTIC ACTION OF A LOW MOLECULARWEIGHT HEPARIN OBTAINED FROM BEEF MUCOSAL ORIGIN AND PEROXIDATIVE CLEAVAGE

1987 ◽  
Author(s):  
P Bianchini ◽  
R Nonn ◽  
J Fareed ◽  
J M Walenga ◽  
A Kumar
Keyword(s):  
Molecular Weight ◽  
Structural Integrity ◽  
Factor Xa ◽  
Inhibitory Effects ◽  
Heparin Cofactor Ii ◽  
At Iii ◽  
Antithrombotic Effects ◽  
In Vitro Systems ◽  
Mean Molecular Weight

We have studied a low molecular weight heparin (LMWH) obtained by acontrolled peroxidative depolymerization of beef mucosal heparin (OP 2123, Opocrin, Corlo, Italy). This product was found to be significantly different from other LMWHs in that it exhibits the same COO-/SO2- ratios as unfractionated heparin, contains reducing end groups composed of 2-sulfated iduronic acid or 6-disulfated glucosamine and retains an identical structural integrity as that of native heparin. As opposed to most other LMWHs the oligosaccharide components of OP 2123 consist of homogeneous progressive units. In addition, the relative amount of AT-IIIaffinity components in OP 2123 were 20-30% less than other LMWHs. OP 2123 has a mean molecular weight of 6200 daltons with a potency of 90 anti-factor Xa U/mg and 68 USP U/mg. This agent produced strong antithrombotic actions in a rabbit stasis model against both an activated prothrombin complex and a prothrombin complex concentrate/Russell's viper venomcombination (ED50:(IV) 30-70 ug/kg;(SC) 0.6-1.5 mg/kg). The antithrombotic effects were comparable to other LMWHs in normal rabbits: however, in AT III depleted rabbits (immunodepleted and y thrombin depleted), OP 2123 produced stronger antithrombotic effects than most other LMWHs. The in vitro systems in contrast to other LMWHs, CP 2123 produced stronger inhibitory effects in AT III depleted plasma as measured by fibrinopeptide A generation and amidolytic anti-factor Xa and anti-factor Ila methods. The relative heparin cofactor II activity as measured by amidolytic method was also found to be higher than with most LMWHs. These results suggest that OP 2123, unlike most LMWHs, non AT III mediated actions play a major role in themendiation of the antithrombotic actions.

Influence of intravascular molecular weight of hydroxyethyl starch on platelets

2009 ◽  
Vol 56 (3) ◽  
pp. 168-172 ◽  
Author(s):  
J. Treib ◽  
A. Haass ◽  
G. Pindur ◽  
W. Treib ◽  
E. Wenzel ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyethyl Starch

Molecular weight of Hydroxyethyl Starch Molecules influences Coagulation Profile measured by thrombelastography

2008 ◽  
Vol 94 (1) ◽  
pp. 7-13
Author(s):  
M Felfernig ◽  
S Virmani ◽  
M Weintraud ◽  
U Oberndorfer ◽  
M Zimpfer ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hydroxyethyl Starch ◽  
Platelet Activating Factor ◽  
Maximum Amplitude ◽  
Coagulation System ◽  
Trauma Patients ◽  
Platelet Activity ◽  
Ringer’S Lactate ◽  
Plasmatic Coagulation ◽  
Key Words Coagulation

SummaryBackgroundThe consensus about the ideal intravenous fluid in trauma patients remains open. However, hypertonic saline and hydroxyethyl starch (HES) seems to have advantages in terms of immuno-modulatory and haemodynamic effects. Nevertheless clotting abnormalities are frequently reported in association with the use of HES. We investigated the influence of light, medium and heavy molecular weight (MW) hydroxyethyl starch (HES) on coagulation in 29 healthy subjects.MethodsRinger’s lactate (RL) served as a control solution. Thrombelastography using Haemoscope’s Thrombelastograph® (TEG®) hemostasis system was used to assess the effect of HES polymers and RL. TEG analysis was performed using recalcified native whole blood both with and without the addition of platelet activating factor IV (PAF IV) before and immediately after infusion of one of the solutions.ResultsInfusion of RL or one of the three HES solutions exerts an anticoagulant effect as demonstrated by a increase in clot formation time (R) and a decrease in maximum amplitude (MA), and the angle. The addition of PAF IV reversed these changes.ConclusionsThis data indicate clear evidence of platelet activity per se or platelet interaction with the plasmatic coagulation system. Key words: Coagulation, thrombelastography, platelets, hydroxyethyl-starch

scholarly journals Chitosan and Carboxymethyl Chitosan from Fish Scales of Labeo rohita

2013 ◽  
Vol 61 (1) ◽  
pp. 145-148 ◽  
Author(s):  
Tanvir Muslim ◽  
Mohammad Habibur Rahman ◽  
HOsne Ara Begum ◽  
Md. Azizur Rahman
Keyword(s):  
Molecular Weight ◽  
Spectral Analysis ◽  
Labeo Rohita ◽  
Carboxymethyl Chitosan ◽  
Degree Of Substitution ◽  
Monochloroacetic Acid ◽  
Fish Scales ◽  
Ft Ir

Chitin was extracted from the fish scales of Labeo rohita and chitosan was successfully prepared from it by deacetylation reaction. The prepared chtiosan was characterized by FT-IR spectral analysis and degree of decetylation was determined by pH-metric titration. The molecular weight of chitosan was estimated by viscometric method. Chitosan was converted into its carboxymethyl derivative using alkali and monochloroacetic acid. The prepared carboxymethyl chitosan was characterized by FT-IR spectral analysis and degree of substitution was estimated. Dhaka Univ. J. Sci. 61(1): 145-148, 2013 (January) DOI: http://dx.doi.org/10.3329/dujs.v61i1.15116

scholarly journals Organic matter exudation by <i>Emiliania huxleyi</i> under simulated future ocean conditions

2012 ◽  
Vol 9 (1) ◽  
pp. 1199-1236 ◽  
Author(s):  
C. Borchard ◽  
A. Engel
Keyword(s):  
Molecular Weight ◽  
Organic Carbon ◽  
Elevated Co2 ◽  
Emiliania Huxleyi ◽  
Greenhouse Condition ◽  
Pronounced Increase ◽  
Temperature Conditions ◽  
Extracellular Release ◽  
Aggregation Processes ◽  
Elevated Co2 And Temperature

Abstract. Emiliania huxleyi (strain B 92/11) was exposed to different growth, CO2 and temperature conditions in phosphorous controlled chemostats, to investigate effects on organic carbon exudation, and partitioning between the pools of particulate organic carbon (POC) and dissolved organic carbon (DOC). 14C incubation measurements for primary production (PP) and for extracellular release (ER) were performed. Chemical analysis included amount and composition of high molecular weight dissolved combined carbohydrates (>1 kDa, HMW-dCCHO), particulate combined carbohydrates (pCCHO) and the carbon content of transparent exopolymer particles (TEP-C). Applied CO2 and temperature conditions were 300, 550 and 900 μatm pCO2 at 14 °C, and additionally 900 μatm pCO2 at 18 °C simulating a greenhouse ocean scenario. A reduction in growth rate from μ =0.3 d−1 to μ =0.1 d−1 induced the most profound effect on the performance of E. huxleyi, relative to the effect of elevated CO2 and temperature. At μ =0.3 d−1, PP was significantly higher at elevated CO2 and temperature. DO14C production correlated to PO14C production in all cultures, resulting in similar percentages of extracellular release (DO14C/PP × 100; PER) of averaged 3.74 &amp;pm; 0.94%. At μ =0.1 d−1, PO14C decreased significantly, while exudation of DO14C increased, thus leading to a stronger partitioning from the particulate to the dissolved pool. Maximum PER of 16.3 &amp;pm; 2.3% were observed at μ =0.1 d−1 at greenhouse conditions. Concentrations of HMW-dCCHO and pCCHO were generally higher at μ =0.1 d−1 compared to μ =0.3 d−1. At μ =0.3 d−1, pCCHO concentration increased significantly along with elevated CO2 and temperature. Despite of high PER, the percentage of HMW-dCCHO was smallest at greenhouse conditions. However, highest TEP-formation was observed under greenhouse conditions, together with a pronounced increase in pCCHO concentration, suggesting a stronger partitioning of PP from DOC to POC by coagulation of exudates. Our results imply that greenhouse condition will enhance exudation processes in E. huxleyi and may affect organic carbon partitioning in the ocean due to an enhanced transfer of HMW-dCCHO to TEP by aggregation processes.

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