Protein C activity and antigen levels in childhood.

Hereditary protein C deficiency is an important risk factor for thrombosis. To enable its diagnosis shortly after birth, we determined reference values of protein C antigen and activity levels for the first 3 months of life. To establish an age-related range of protein C levels we also determined median values for individuals up to 18 years of age.

[Is circumoral cyanosis a sign of peripheral or of central cyanosis?].

Two hundred Dutch paediatricians were invited to give their description and interpretation of the concept of 'circumoral cyanosis'. Analysis of the results shows great inter-doctor variability: 63% considered the circumoral cyanosis as a pathologic sign and 70% as an expression of central cyanosis, although in textbooks and publications this sign is defined as an expression of peripheral cyanosis and is not considered to be pathological.

Low antithrombin III: accurate predictor of idiopathic respiratory distress syndrome in premature neonates.

A prospective study was performed in premature neonates to determine the predictive values of antithrombin III (AT III) deficiency immediately after birth, for the subsequent development of idiopathic respiratory distress syndrome (IRDS), intraventricular haemorrhage (IVH) and death. Of the 81 premature infants studied, 24 developed IRDS (30%). Of these 24 premature infants, 8 also developed IVH and 9 infants died within the follow-up period of 7 days.

Low AIDS attack rate among Dutch haemophiliacs compared to homosexual men: a correlate of HIV antigenaemia frequencies.

A cohort of 180 haemophiliacs followed between 1983 and 1986 and a cohort of 961 homosexual men followed between 1984 and 1986 were compared for the prevalence and incidence of HIV-1 antibody (HIV-1-Ab) seropositivity, the incidence of AIDS-related complex (ARC) and AIDS and the prevalence and incidence of serological and immunological markers for HIV-related disease progression. Among the haemophiliacs 23 (12.8%) patients were HIV-1-Ab seropositive at entry and 20 (12.

HIV-antibody seroconversions in Dutch haemophiliacs using heat-treated and non heat-treated coagulation factor concentrates.

A national multicentre study was performed to investigate the effects of donorselection and the use of heat-treated plasma products on seroconversion to HIV in 157 Dutch haemophiliacs. All patients included in the study were seronegative for HIV antibodies in 1983. Thirteen percent (20/157) seroconverted between 1983 and 1986.

Pathogenesis of HIV and its implications for serodiagnosis and monitoring of antiviral therapy.

Human immunodeficiency virus (HIV) is lymphotropic and neurotropic. In vivo clinical and immunological abnormalities develop in a large proportion of long-term HIV antibody seropositive persons. Different stages of HIV infection are marked by expression of HIV genes, production of HIV antibodies, formation of antigen/antibody complexes and clearance of such complexes.

Normal synthesis and expression of endothelial IIb/IIIa in Glanzmann's thrombasthenia.

Glanzmann's thrombasthenia is a bleeding disorder, inherited in an autosomal recessive way and characterized by an absence or deficiency of the platelet glycoprotein (GP) IIb/IIIa complex. Recently, we and others demonstrated that cultured human umbilical vein endothelial cells synthesized a membrane protein complex similar to the platelet GP IIb/IIIa complex. In this article, we demonstrate that endothelial cells isolated from the umbilical vein of a newborn with Glanzmann's thrombasthenia, as compared with normal endothelial cells, show no difference in their ability to synthesize and express this GP IIb/IIIa complex.

Cerebral thromboembolism due to antithrombin III deficiency in two children.

Despite numerous well-described causes of stroke in infancy and childhood, a significant proportion remains unexplained. Venous thromboembolism is a common complication in adult patients undergoing surgery, and after severe trauma, but not in otherwise healthy children less than 10 years old. However, it may also occur spontaneously without recognizable cause.

Vitamin-K status beyond the neonatal period. A prospective study in normal breast-fed and formula-fed infants.

Vitamin K-dependent clotting factors (FII, FVII, FX) and PT and TT were studied prospectively in 113 healthy newborns during the first 6 weeks of life. No vitamin K prophylaxis was given. Infants were divided into three groups: breast fed, formula fed or combination.

Antibodies to the human T-cell lymphoma/leukemia virus type I in Dutch haemophiliacs.

95 Dutch haemophiliacs were tested for antibodies to membrane antigens on cells infected with human T-cell leukemia virus type I (HTLV-I-MA) by indirect immunofluorescence and to purified HTLV-I by enzyme-linked immunosorbent assay. Antibodies to HTLV-I-MA were present in 8 of 95 (8%) haemophiliacs, but only 3 (3%) had antibodies to purified HTLV-I. No clinical disease was related to HTLV-I seropositivity.

Coagulation and fibrinolytic factors in the first week of life in healthy infants.

Coagulation and fibrinolytic factors were determined daily in 74 healthy term and preterm infants to obtain a reference standard. A gestational age dependency was determined for antithrombin III, factor II, and plasminogen. The mean concentrations of antithrombin III and factor II in preterm infants increased to term values within the first week of life.

Neonatal antithrombin III.

Antithrombin III (AT-III) heparin cofactor activity and its antigen levels have been determined in 106 plasma samples from 42 term and preterm neonates. In contrast to healthy adult controls, a reduced activity/antigen (act/ag) ratio (ranging from 0.26 to 0.

Persistent antithrombin III deficiency: risk factor for thromboembolic complications in neonates small for gestational age.

Coagulation and fibrinolytic factors were investigated daily in 24 SGA and 26 AGA neonates. The results were correlated with placental form and structure and with hematologic values. In the SGA infants, a higher incidence of placental infarction (P less than 0.

Low antithrombin III levels in neonates with idiopathic respiratory distress syndrome: poor prognosis.

Automated microanalytic chromogenic coagulation assays allow serial monitoring of critically ill newborn infants. In this study 84 premature infants [26 healthy prematures and 58 neonates with idiopathic respiratory distress syndrome (IRDS)] were studied daily during the first week of life, to investigate the possible significance of hemostatic abnormalities in IRDS. In neonates with IRDS, coagulation factors II and X, antithrombin III (AT-III), plasminogen, and alpha 2-antiplasmin were significantly lower than control values.

Lumbar arterial rupture secondary to iliopsoas hemorrhage in a hemophiliac patient.

A 62-year-old subhemophiliac patient developed a severe iliopsoas hemorrhage following minor trauma. CT scanning revealed a large iliopsoas hematoma and intraperitoneal hemorrhage. Angiography demonstrated active bleeding from the fourth right lumbar artery, a complication of an iliopsoas hematoma not previously described.

Identification of a contaminant protein in the purification of human factor V. Comparison of two purification methods.

Coagulation factor V has been isolated from human plasma by the methods of Bolhuis and of Kane to investigate reported differences in purity and specific activity. The specific activities of the preparations are 10 and 40 units/mg, respectively. The Kane preparation shows a single band (Mr 330 000) in polyacrylamide gel electrophoresis in the presence and absence of dithiothreitol, but the Bolhuis preparation shows an additional band at Mr 190 000 upon reduction with dithiothreitol.

Rapid microanalysis of coagulation parameters by automated chromogenic substrated methods - application in neonatal patients.

Daily monitoring of coagulation parameters in critically ill premature born neonates is only possible on small amounts of blood obtained by heelpuncture. Therefore, automated spectrophotometric micro-assays for antithrombin III (AT III), factors II and X, plasminogen and alpha 2 antiplasmin were applied on capillary and venous blood samples concurrently obtained in adults and healthy neonates. No statistically significant difference for any of the parameters was revealed.