Fetales Fibrinogen

Knzer, W.

doi:10.1007/bf01490048

Cited by 31 publications

(3 citation statements)

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“…Functional anomalies of several proteins with coagulant activity, especially fibrinogen (5,21,42) and prothrombin (32,33), have been described in full-term newborns (FTN), but in the literature that we have reviewed, a functional anomaly of FTN plasminogen has not been described.…”

Section: Speculationmentioning

confidence: 94%

Dysfunctional Plasminogen in Full-Term Newborn

et al. 1980

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SummaryEVALUATION AND PURIFICATION OF PLASMA PLASMINOGEN Full-term newborns (FTN) plasminogen was evaluated by different techniques (affinity chromatography, immunologic technique, casein method, and chromogenic substrate). The functional activity of the FTN plasminogen was about 50% of that of the adult. This suggests the possible existence of a functional anomaly of plasminogen in FTN.FTN plasminogen aminoacids were studied, and, besides small qualitative anomalies, a decrease in amino acid residues per mole of protein and a different N-terminal amino acid were detected. SpeculationThe existence of a functional anomaly in full-term newborns' plasminogen has been suggested. The possible role of this anomaly in the pathogenesis of the hemorraghic diseases of the neonate and in hyaline membrane disease is not known, thus, the identification of this anomaly could contribute to a better understanding of these diseases.Functional anomalies of several proteins with coagulant activity, especially fibrinogen (5, 21, 42) and prothrombin (32, 33), have been described in full-term newborns (FTN), but in the literature that we have reviewed, a functional anomaly of FTN plasminogen has not been described.In this paper, FTN plasminogen was evaluated by different techniques (affinity chromatography, immunologic technique, casein method, and chromogenic substrate), and the existence of a functional anomaly in plasminogen was suggested. MATERIALS AND METHODSBlood samples of normal adults were collected from the cubital vein and from those of FTN (Apgar 9/10), born spontaneously with no application of analgesic-anesthesic agents, from the umbilical vein. 5 min after birth. The blood was anticoagulated with 3.8% sodium citrate (1:9. v/v. anticoagulant:blood). The samples were divided into two tubes; 250 Kallikrein inactivating units of trasylol per ml of blood were added to one of the tubes. The samples were kept in ice during all these procedures. The plasmas were obtained by centrifugation at 3000 rpm for 15 min at 4°C.Reagents: Human plasminogen (Kabi; 25 CU/vial); alpha casein (Sigma Chemical Co.), streptokinase (SK) (Behringwerke, 5,000 U/vial; Kabi 250,000 U/vial); urokinase (UK) (Roger. 25,000 units/vial); antiplasminogen serum (Behringwerke); Sepharose 4B activated with cyanogen bromide (Pharmacia Fine Chemical); chromogenic substrate (Kabi, S-225 1). EVALUATION OF PLASMATIC ANTIFIBRINOLYTLC ACTIVITYTo evaluate plasmatic antifibrinolytic activity, the antiplasmins (chromogenic substrate) (37) and the antistreptokinases (18) were determined.Plasminogen was assayed by the following techniques: hemaglutination inhibition method as proposed by Wu et al. (43) and modified by Estelles et a/. (I I) by using commercial plasminogen as the standard in each experiment; the casein method of Hedner and Nilsson (19). but using urokinase [neutralized plasma (55 units/ml)] to activate plasminogen (a reference curve of a pool of normal plasmas was plotted every day); the chromogenic substrate (S-225 I) method, in which the plasminogen was...

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Section: Speculationmentioning

confidence: 94%

Dysfunctional Plasminogen in Full-Term Newborn

et al. 1980

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“…The absolute and relative concentrations of some compo nents of the coagulation system differ from the adults, and they are dependent on both the gestational age and postnatal age [2,6,[19][20][21][22][23]. Additionally, functional abnormalities of several coagulation proteins, especially fibrin ogen [24][25][26][27] and prothrombin [28], have been described in full-term newborns. Fetal fibrinogen is comparatively insensitive to thrombin-induced proteolysis and has an in creased sialic acid content compared to adult fibrinogen; this varies with the degree of pre maturity and correlates to the prolongation of the thrombin clotting time [24][25][26][27], The fibrinolytic system is involved in a wide variety of biological phenomena.…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, functional abnormalities of several coagulation proteins, especially fibrin ogen [24][25][26][27] and prothrombin [28], have been described in full-term newborns. Fetal fibrinogen is comparatively insensitive to thrombin-induced proteolysis and has an in creased sialic acid content compared to adult fibrinogen; this varies with the degree of pre maturity and correlates to the prolongation of the thrombin clotting time [24][25][26][27], The fibrinolytic system is involved in a wide variety of biological phenomena. Fibrin formed during coagulation is degraded by plasmin, which is formed through conversion of plasminogen by t-PA or urokinase-type plasminogen activator (u-PA).…”

Section: Discussionmentioning

confidence: 99%

The Role of α<sub>2</sub>-Antiplasmin in the Inhibition of Clot Lysis in Newborns and Adults

Ries

Klinge²,

Rauch³

et al. 1996

Neonatology

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The fibrinolytic system is involved in a wide variety of biological phenomena and differs physiologically in newborns compared to older children or adults. Newborn’s plasminogen differs from adult plasminogen in carbohydrate composition, cell binding and activation kinetics. The fetal plasminogen has an increased concentration of sialic acid similar to fetal fibrinogen. In a previously reported study on plasminogen activation kinetics, we demonstrated differences in the reaction kinetics between fetal plasmin and plasmin inhibitors as compared to the reaction between adult plasmin and inhibitors. Hitherto, there are no investigations on the role of α₂-antiplasmin in the inhibition of clot lysis in newborns. We studied the contributions of purified α₂-antiplasmin to the regulation of fibrin clot lysis by use of a microtiter clot lysis assay. The lysis time of clots without adding purified α₂-antiplasmin correlated to the activator dose. When purified α₂-antiplasmin was incorporated at final concentrations ranging from 10 to 40 μg/ml, strong dose-dependent inhibition resulting in a prolongation of 50% lysis time was observed. The inhibition in newborns at all α₂-antiplasmin concentrations was less pronounced than that of the adults if 50% lysis time was < 55 min. If 50% lysis time was > 55 min, the prolongation of 50% lysis time was more pronounced in newborn than in adult plasma. The fact that we have less effects of α₂-antiplasmin in newborn infants at short reaction times despite the lower plasminogen levels, is consistent with slower reaction kinetics between plasmin and α₂-antiplasmin in newborns. These differences raise an explanation for the findings of Idell et al. [Am J Respir Crit Care Med 1994;149:767–775] in premature baboons with neonatal respiratory distress syndrome (RDS). The knowledge of different reaction kinetics between plasmin and α₂-antiplasmin and the role of α₂-antiplasmin in the inhibition of clot lysis in newborns can be helpful to elucidate the significance of the fetal fibrinolytic system in neonatal RDS and to establish treatment strategies for fîbrinolytic therapy of progressive RDS.

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