In vitro nerve-growth-promoting activity of human plasma ?1-acid glycoprotein

1988 ◽  
Vol 20 (1) ◽  
pp. 64-72 ◽  
Author(s):  
H. M. Liu ◽  
K. Takagaki ◽  
K. Schmid
Keyword(s):  
Human Plasma ◽  
Nerve Growth ◽  
Acid Glycoprotein ◽  
Growth Promoting

Potentially Thrombogenic Materials in Factor IX Concentrates

1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson
Keyword(s):  
Human Plasma ◽  
Antithrombin Iii ◽  
Factor Ix ◽  
In Vitro Assays ◽  
Substantial Agreement ◽  
Coefficient Of Correlation

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.

Presence and Possible Origin of ɛ(γ-Glutamyl)Lysine Isodipeptide in Human Plasma

1992 ◽  
Vol 67 (01) ◽  
pp. 060-062 ◽  
Author(s):  
J Harsfalvi ◽  
E Tarcsa ◽  
M Udvardy ◽  
G Zajka ◽  
T Szarvas ◽  
...  
Keyword(s):  
Human Plasma ◽  
Fibrinolytic Therapy ◽  
Normal Human Plasma ◽  
Normal Human ◽  
Hplc Technique ◽  
Significant Change

Summaryɛ(γ-glutamyl)lysine isodipeptide has been detected in normal human plasma by a sensitive HPLC technique in a concentration of 1.9-3.6 μmol/1. Incubation of in vitro clotted plasma at 37° C for 12 h resulted in an increased amount of isodipeptide, and there was no further significant change when streptokinase was also present. Increased in vivo isodipeptide concentrations were also observed in hypercoagulable states and during fibrinolytic therapy.

Observations on the in vitro Effects of Chylomicra, Low-Density Lipoproteins and Phospholipids on Human Plasma Euglobulin Lysis

1963 ◽  
Vol 09 (01) ◽  
pp. 164-174 ◽  
Author(s):  
Albert R Pappenhagen ◽  
J. L Koppel ◽  
John H Olwin
Keyword(s):  
Human Plasma ◽  
Phosphatidyl Ethanolamine ◽  
Phosphatidyl Inositol ◽  
Plasma Lipoproteins ◽  
Low Density ◽  
Inhibitory Effects ◽  
Soybean Phospholipids ◽  
In Vitro Effects ◽  
Complete Precipitation

SummaryData have been presented on the in vitro effects of human chylomicra, low-density human plasma lipoproteins, and partially purified preparations of various phospholipids on human plasma euglobulin lysis. Euglobulin lysis was found to be accelerated by preparations of mixed soybean phospholipids (aso-lectin), cephalin, phosphatidyl inositol, phophatidyl serine and phosphatidyl ethanolamine. In contrast, it was found to be inhibited by preparations of human chylomicra, low-density human plasma liproproteins and lecithin. Inhibition of euglobulin lysis produced by any of these three agents could be diminished or completely overcome by the simultaneous presence of suitable levels of any one of the accelerating agents. In all cases studied, both inhibitory and accelerating effects were observed to be concentration-dependent. Evidence has been obtained to suggest that in the case of the accelerating agents the observed increased rate of euglobulin lysis is not a direct effect on lysis itself, but rather is due to more complete precipitation of plasminogen in the presence of these substances. On the other hand, it appears that the inhibitory effects observed are not related to the extent of plasminogen precipitation, but are actually true inhibitions of euglobulin lysis. The possible clinical significance of some of these observations has been briefly discussed.

Absence of Synergism Between Tissue-Type Plasminogen Activator (t-PA), Single-Chain UrokinaseType Plasminogen Activator (scu-PA) and Urokinase on Clot Lysis in a Plasma Milieu In Vitro

1986 ◽  
Vol 56 (01) ◽  
pp. 035-039 ◽  
Author(s):  
D Collen ◽  
F De Cock ◽  
E Demarsin ◽  
H R Lijnen ◽  
D C Stump
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Dose Response ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
Clot Lysis ◽  
Single Chain ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryA potential synergic effect of tissue-type plasminogen activator (t-PA), single-chain urokinase-type plasminogen activator (scuPA) or urokinase on clot lysis was investigated in a whole human plasma system in vitro. The system consisted of a human plasma clot labeled with 125I-fibrinogen, immersed in titrated whole human plasma, to which the thrombolytic agents were added. Clot lysis was quantitated by measurement of released 125I, and activation of the fibrinolytic system in the surrounding plasma by measurements of fibrinogen and α2-antiplasmin.t-PA, scu-PA and urokinase induced a dose-dependent and time-dependent clot lysis; 50 percent lysis after 2 h was obtained with 5 nM t-PA, 20 nM scu-PA and 12 nM urokinase. At these concentrations no significant activation of the fibrinolytic system in the plasma was observed with t-PA and scu-PA, whereas urokinase caused significant α2-antiplasmin consumption and concomitant fibrinogen degradation. The shape of the dose-response curves was different; t-PA and urokinase showed a log linear dose-response whereas that of scu-PA was sigmoidal.

THE NATURE OF THE GROWTH-PROMOTING SUBSTANCES IN HUMAN PLASMA

1967 ◽  
Vol 56 (1_Suppl) ◽  
pp. S238 ◽  
Author(s):  
K. A. Ferguson ◽  
L. Lazarus ◽  
P. van Dooren ◽  
J. D. Young
Keyword(s):  
Human Plasma ◽  
Growth Promoting

Neuroprotective and anti-amnestic effects of a combination therapy in a model of photochemical ischemic damage in the prefrontal cortex

2018 ◽  
pp. 39-45
Author(s):  
Ф.М. Шакова ◽  
Т.И. Калинина ◽  
М.В. Гуляев ◽  
Г.А. Романова
Keyword(s):  
Prefrontal Cortex ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Combination Therapy ◽  
Neuroprotective Effect ◽  
Regulatory Protein ◽  
Human Growth ◽  
Neuroprotective Effects ◽  
Nerve Growth

Цель исследования - изучение влияния комбинированной терапии (мутантные молекулы эритропоэтина (EPO) и дипептидный миметик фактора роста нервов ГК-2H) на воспроизведение условного рефлекса пассивного избегания (УРПИ) и объем поражения коры мозга у крыс с двусторонним ишемическим повреждением префронтальной коры. Методика. Мутантные молекулы EPO (MЕРО-TR и MЕPО-Fc) с значительно редуцированной эритропоэтической и выраженной цитопротекторной активностью созданы методом генной инженерии. Используемый миметик фактора роста нервов человека, эндогенного регуляторного белка, в экспериментах in vitro проявлял отчетливые нейропротективные свойства. Двустороннюю фокальную ишемию префронтальной коры головного мозга крыс создавали методом фотохимического тромбоза. Выработку и оценку УРПИ проводили по стандартной методике. Объем повреждения мозга оценивался при помощи МРТ. MEPO-TR и MEPO-Fc (50 мкг/кг) вводили интраназально однократно через 1 ч после фототромбоза, ГК-2Н (1 мг/кг) - внутрибрюшинно через 4 ч после фототромбоза и далее в течение 4 послеоперационных суток. Результаты. Выявлено статистически значимое сохранение выработанного до ишемии УРПИ, а также значимое снижение объема повреждения коры при комплексной терапии. Полученные данные свидетельствуют об антиамнестическом и нейропротекторном эффектах примененной комбинированной терапии, которые наиболее отчетливо выражены в дозах: МEPO-Fc (50 мкг/кг) и ГК-2Н (1 мг/кг). Заключение. Подтвержден нейропротекторный эффект и усиление антиамнестического эффекта при сочетанном применении мутантных производных эритропоэтина - MEPO-TR и MEPO-Fc и дипептидного миметика фактора роста нервов человека ГК-2H. The aim of this study was to investigate the effect of combination therapy, including mutant erythropoietin molecules (EPO) and a dipeptide mimetic of the nerve growth factor, GK-2H, on the conditioned passive avoidance (PA) reflex and the volume of injury induced by bilateral ischemia of the prefrontal cortex in rats. Using the method of genetic engineering the mutant molecules of EPO, MERO-TR and MEPO-Fc, with strongly reduced erythropoietic and pronounced cytoprotective activity were created. The used human nerve growth factor mimetic, an endogenous regulatory protein based on the b-bend of loop 4, which is a dimeric substituted dipeptide of bis- (N-monosuccinyl-glycyl-lysine) hexamethylenediamine, GK-2 human (GK-2H), has proven neuroprotective in in vitro experiments. Methods. Bilateral focal ischemic infarction was modeled in the rat prefrontal cortex by photochemically induced thrombosis. The PA test was performed according to a standard method. Volume of brain injury was estimated using MRI. MEPO-TR, and MEPO-Fc (50 mg/kg, intranasally) were administered once, one hour after the injury. GK-2Н (1 mg/kg, i.p.) was injected four hours after the injury and then for next four days. Results. The study showed that the complex therapy provided statistically significant retention of the PA reflex developed prior to ischemia and a significant decrease in the volume of injury. The anti-amnestic and neuroprotective effects of combination therapy were most pronounced at doses of MEPO-Fc 50 mg/kg and GK-2H 1 mg/kg. Conclusion. This study has confirmed the neuroprotective effect and enhancement of the anti-amnestic effect exerted by the combination of mutant erythropoietin derivatives, MEPO-TR and MEPO-Fc, and the dipeptide mimetic of human growth factor GK-2H.

Total weak acid concentration and effective dissociation constant of nonvolatile buffers in human plasma

2001 ◽  
Vol 91 (3) ◽  
pp. 1364-1371 ◽  
Author(s):  
Peter D. Constable
Keyword(s):  
Dissociation Constant ◽  
Human Plasma ◽  
Total Concentration ◽  
Weak Acid ◽  
Strong Ion Difference ◽  
Acid Base ◽  
Horse Plasma ◽  
Using Data ◽  
Species Specific

The strong ion approach provides a quantitative physicochemical method for describing the mechanism for an acid-base disturbance. The approach requires species-specific values for the total concentration of plasma nonvolatile buffers (Atot) and the effective dissociation constant for plasma nonvolatile buffers ( K a), but these values have not been determined for human plasma. Accordingly, the purpose of this study was to calculate accurate Atot and K a values using data obtained from in vitro strong ion titration and CO2tonometry. The calculated values for Atot (24.1 mmol/l) and K a (1.05 × 10−7) were significantly ( P < 0.05) different from the experimentally determined values for horse plasma and differed from the empirically assumed values for human plasma (Atot = 19.0 meq/l and K a = 3.0 × 10−7). The derivatives of pH with respect to the three independent variables [strong ion difference (SID), Pco 2, and Atot] of the strong ion approach were calculated as follows: [Formula: see text] [Formula: see text], [Formula: see text]where S is solubility of CO2 in plasma. The derivatives provide a useful method for calculating the effect of independent changes in SID+, Pco 2, and Atot on plasma pH. The calculated values for Atot and K a should facilitate application of the strong ion approach to acid-base disturbances in humans.

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