Preprothrombin and Prothrombin in Full-Term Newborns

Schettini, Franco; Mattia, Domenico De; Mautone, A

doi:10.1159/000213995

Cited by 11 publications

(9 citation statements)

References 13 publications

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“…According to the elimination rate of vitamin K1; a depletion could occur in 7.3-9 h. However, it is not known whether the liver of the neonate can regenerate vitamin K from the epoxide [8] and if the plasma clearance of vitamin K at low concentration is similar to that of the present findings with a large dose of vitamin K. Further studies are required to answer these questions and to determine if repeated doses are necessary during the 1st month of life. If the stores of vitamin K are low in the neonatal liver, one can understand that the absence of activation of the low concentration of circulating prothrombin [5,15,17] could become harmful in some in fants.…”

Section: Discussionmentioning

confidence: 99%

Pharmacokinetics of Vitamin K(1) in Low-Birth-Weight Neonates

Sann¹,

Leclercq²,

Frederich³

et al. 1985

Dev Pharmacol Ther

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The pharmacokinetics of vitamin K(1) was studied in 21 newborn infants. 11 neonates had received no parenteral loading dose prior to the study (group I), while 10 had been injected 5-10 mg vitamin K(1), at birth (group II). At postnatal age 2-9 h, 1 mg of vitamin K(1) was injected intravenously, and small samples of blood (≤ 500µl) were collected at different times during 6 h. Serum vitamin K(1) and its epoxide were assayed by high-performance liquid chromatography (HPLC). In both groups, the disappearance curve showed two exponential components: a fast distribution component during the 1 st h and a slower elimination component during the next 5 h. In group I, the plasma half-life of the first component was between 18 and 52 min (median 23 min), and the half-life of the second was between 67 and 179 min (median 109 min). Both half-lives were significantly higher in group II. The volumes of distribution were suggestive of distribution into plasma during the first phase and roughly into the extracellular water for the second component. Epoxide was detected in most patients 15 min after vitamin K(1) injection, and after 3 h its concentration was higher than the concentration of vitamin K(1). These data suggest that the kinetics of vitamin K(1) in neonates is not very different from that in adults. The newborn infant is able to oxidize vitamin K(1), a phenomenon in keeping with the gamma carboxylation of glutamic acid.

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Section: Discussionmentioning

confidence: 99%

Pharmacokinetics of Vitamin K(1) in Low-Birth-Weight Neonates

Sann¹,

Leclercq²,

Frederich³

et al. 1985

Dev Pharmacol Ther

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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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“…ing with the activity of the coagulation factors. Immunologic determinations of these factors were done in only a few studies TWO-DIMENSIONAL ~MMUNOELECTROPHORES~S WITH A BARBITAL (15,19). In this study, prothrombin was investigated with a specific BUFFER WITH 25 mM CALCIUM LACTATE iabbit antiserum.…”

Section: Two-dimensional Immunoelectrophoresis Wlth a Barbital Buffermentioning

confidence: 99%

Immunologic Studies of Prothrombin in Newborns

et al. 1979

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SummaryProthrombin of newborns was investigated by means of the quantitative immunoelectrophoresis and the two-dimensional immunoelectrophoresis. The plasma of 10 of 24 healthy term newborns and of 5 preterm infants taken immediately after birth showed one prothrombin precipitate in the a-2-fi-globulin position when a buffer containing 25 mM calcium lactate was used. No differences in the mobility and form of the precipitate could be observed as compared to healthy adults. The plasma of the other 14 term newborns and one small-for-date infant showed two precipitates, one in the a-2-&globulin position and a second in the a-1-globulin position. Twenty-four hr after the injection of vitamin K, the precipitate in a-1-globulin position was no longer evident.When a buffer without calcium was used in the two-dimensional immunoelectrophoresis, only one precipitate in the a-1-globulin position was found in all newborns. In the quantitative immunologic determination, the prothrombin was found to be decreased as compared to that of adults. The quantitative immunologic determination and the activity assay gave equal results in those infants who had only one precipitate in the two dimensional immunoelectrophoresis. In those newborns, who had two precipitates, the quantitative immunologic determination gave higher results than the measurement of the activity assay.From this study, no evidence of differences between the prothrombin of newborns and that of adults could be derived. Vitamin K deficiency, as judged from the appearance of a second peak in a-1-globulin position in the two dimensional immunoelectrophoresis was a frequent finding in term newborns, even on the 1st day of life. small for date. Five were prematures with a gestational age of 3 1-35 wk. None of these five prematures had perinatal problems, in spite of their prematurity. All but two children received 1 mg/kg vitamin K (Konakion) im shortly after birth.Immediately after birth, blood was drawn from the umbilical vein and again 24 hr afterwards by puncturing a peripheral vein. Blood samples were collected in plastic tubes containing 1/10 volume of 0.1 M trisodium citrate. The plasma was stored at -20' C until the determinations were carried out.Prothrombin activity was determined by the one stage assay (20) using a test kit of the Behring Co.Prothrombin was quantified immunologically according to Laurel] (1 I), using a monospecific rabbit antiserum against prothrombin (Behring Co): 1% agarose, barbital buffer of a pH of 8.6, 6-7 V/cm.Calibration curves for the activity and for the quantitative immunologic determination were done with a pooled plasma of 20 healthy adults and the results were expressed in percent of this pooled piasma. Two-dimensional immunoelectrophoresis (4, 5) was done, using rabbit antiserum against human prothrombin 1) with a barbital buffer of a pH of 8.6 and 2) with a barbital buffer of a pH of 8.6 and 25 mM calcium lactate. Agarose, 1%, first dimension 6-7 V/ cm for 4 hr, second dimension 2-3 V/cm for 12-14 hr.Plasma of healthy adults a...

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Preprothrombin and Prothrombin in Full-Term Newborns

Cited by 11 publications

References 13 publications

Pharmacokinetics of Vitamin K(1) in Low-Birth-Weight Neonates

Pharmacokinetics of Vitamin K(1) in Low-Birth-Weight Neonates

Dysfunctional Plasminogen in Full-Term Newborn

Immunologic Studies of Prothrombin in Newborns

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