FIBRINOLYSIS IN HUMAN FOETUSES

The fibrinolytic system was studied in blood from 74 human foetuses in the 12th to 24th gestational week and with crown-heel lengths between 10 and 32 cm. Plasminogen could be demonstrated in all foetuses in an amount equal to about 20 per cent of that in adults. There was also a definite plasminogen activator activity and a remarkable fibrinolytic capacity. The α₂-macro-globulin content was about 30 per cent of that in adults, while progressive antiplasmin was at, and the inhibitors of plasminogen activationabove, adult level. The fibrinolytic system develops early in intrauterine life. Like other enzyme systems essential to life, it must serve some physiologic purpose, presumably to keep the foetomaternal circulation patent.     

ABNORMAL PROTEOLYSIS IN SICK NEWBORNS

ABSTRACT: Henriksson, P. and Ekelund, H. (Department of Paediatrics, University of Lund, Allmänna Sjukhuset, Malmö, Sweden). Abnormal proteolysis in sick newborns. Acta Paediatr Scand, 64:327, 1975–87 newborn infants were studied on their first day of life for defects in the coagulation and fibrinolytic systems. The infants were divided into two diagnostic groups, one with IRDS, the other with mixed neonatal disorders. Factor V, fibrinogen and fibrin/fibrinogen degradation products (FDP) were abnormal more often than any of the other factors examined. The presence or absence of "multiple defects" appeared to depend on the severity of the illness and its ultimate course. Thus 28% of the surviving infants or 85% of those who died had "multiple defects". The pattern of abnormalities did not differ between the infants with IRDS and those with mixed disorders. The "multiple defects" are ascribed to the following mechanisms: (1) impaired synthesis due to vitamin K deficiency and/or liver damage, (2) abnormal proteolytic activity stimulated by tissue damage and causing (a) an activation of the coagulation process (b) activation of the fibrinolytic system, or (c) of both the coagulation and the fibrinolytic systems. Differentiation between these pathways to defective haemostasis are important when deciding upon therapeutic measures in addition to the basic treatment.     

FIBRINOLYSIS IN LYMPHANGIOMA

Two operations upon a giant gluteal lymph-angioma in a boy were complicated by massive haemorrhage. The complication proved to be due to fibrinolysis stimulated by activators released by the tumour. The diagnosis was confirmed by the demonstration of high fibrino-lytic activity and FDP in blood and discharge drained from the wound. The bleeding was effectively controlled by AMCA (tranexamic acid, Cyclokapron®). Long-term treatment with AMCA was accompanied by further reduction in size of the lymphangioma.     

PLATELET AGGREGATION IN TERM AND PRETERM NEWBORNS

The platelets of newborns have a hyporeactive period. This period, during which the platelet count is normal but their functions are deficient, is called transient platelet hyporeactivity of newborns. The platelet functions and their normalizing process of term and preterm neonates are investigated. Twenty term and 20 preterm (gestational age <37 weeks) newborns were enrolled in the study. Twenty-eight healthy children aged 2 months to 3 years old participated in the study as the control group. Healthy newborns were followed for 15 days after birth longitudinally in 3 periods: period 1 (0–4 days), period 2 (5–9 days), period 3 (10–15 days). Aggregation studies were performed from whole blood samples. Whole blood aggregation was measured by the impedance method. Transient hyporeactivity of platelets was found in term and preterm groups, and there was no difference between term and preterms. Platelets of newborns gained their normal functions at postnatal 10–14 days. The results show that hyporeactivity of platelets during the first 9 days of life is physiological and transient.     

FACTOR VIII ACTIVITY AND ANTIGEN IN SICK NEWBORNS WITH PATHOLOGICAL PROTEOLYSIS IN BLOOD

ABSTRACT. Factor VIII clotting activity (VII:C) and factor VIII related antigen (VIII:R:AG) were determined in 12 sick newborn infants with pathological proteolysis in their circulation. A marked discrepancy was noted between VIII:R:AG and VIII:C, the ratio in sick infants being, on average, 2: 1, while no discrepancy was seen in healthy newborns. The finding in the sick infants resembled a low grade plasminogen activation, which was studied experimentally. It is concluded that demonstration of a marked discrepancy between VIII: R: AC, and VIII:C is a useful indication of pathological proteolysis in sick newborns.     

PROTHROMBIN IN NEWBORNS AND DURING THE FIRST YEAR OF LIFE

Prothrombin concentration, determined specifically with a new two-stage method, was compared with thrombotest activity in samples from infants, aged 0–21 days. There was a significant correlation between the two methods. Effect of treatment with vitamin K and plasma was registered with both methods. As the distribution of prothrombin and thrombotest values from normal, full-term neonates was slightly skew, mean value and S.D. was calculated from the logarithmic values. The normal range, expressed as mean ± 2 S.D. was for prothrombin 26–85 % and for thrombotest 27–74% (values corrected for hematocrit). No bleeding was observed in any patient with prothrombin above 20% and thrombotest above 22% (corrected values). Most low values in newborns were found in children suffering from hypoxia. Prothrombin concentration was also compared with prothrombin-proconvertin activity in samples from children, aged 0–12 months. In the healthy child prothrombin values reached the normal adult level at the age of 6–12 months, prothrombin-proconvertin values at the age of about 3 months.     

BLOOD GLUCOSE DETERMINATIONS IN NEWBORNS: Four Instruments Compared

Four portable analyzers, HemoCue B-Glucose (I), Accu-Check III (II), One-touch II (III), and Glucometer Elite (IV), with different measuring principles were tested for their suitability for measuring blood glucose in neonates. Precision of all instruments is satisfactory. In the analysis of capillary blood from newborns, two instruments show an excellent accuracy; however, the scatter of the results for instrument (II) is about 1.6 times greater than for instrument (I). The inaccuracy of instruments (III) and (IV) is not acceptable from a clinical point of view. All devices show an influence of hematocrit, the magnitude of which varies between 5 (I) and 12 (III) for every 10 change of hematocrit. Instruments II and IV show that temperature has a marked influence on the readings; the same is true for oxygen in instrument IV. In conclusion, only instrument (I) has met the requirements of accurate and precise blood glucose determinations in neonates.     

EFFECT OF LIGHT EXPOSURE ON GUT TRANSIT TIME IN JAUNDICED NEWBORNS

In order to elucidate the mechanism by which phototherapy induces loose stools in newborns, studies were performed on the speed of gut transit by performing the Carmine Red test on normal newborn, on jaundiced newborns before and after phototherapy. A statistically accelerated intestinal transit was observed in jaundiced newborns treated with phototherapy. The increased rate of intestinal transit produced by phototherapy is probably due to the action of the photo-decomposition derivatives of bilirubin, which are excreted during phototherapy.     

SOMATOMEDIN IN NEWBORNS AND THE RELATIONSHIP TO HUMAN CHORIONIC SOMATOTROPIN AND FETAL GROWTH

ABSTRACT. The significance of somatomedin A (SM) and human chorionic somatomammotropin (HCS) in fetal growth was examined. SM, determined by chick embryo assay, was studied during the last trimester of pregnancy, in maternal serum and cord blood at term and in a group of normal newborns in the first week of life. Furthermore a group of newborns of diabetic mothers was studied in the first or second day of life. HCS was measured in maternal serum and in cord blood at term. In amniotic fluid inhibitory factors caused a low SM activity as measured by the bioassay. The following results were obtained: 1) Normal values of SM in the last trimester with a decline at term were found in 3 normal primigravidae. 2) The mean levels of SM in 22 mothers and their offspring were decreased. The difference between the two values was significant, but a positive correlation was found between the maternally related pairs of SM values. Moreover, a positive correlation was found between maternal SM, birth weight and length. HCS was not correlated to above-mentioned parameters, but there was positive correlation between placental weight and birth weight. 3) In 6 newborns during the first 5 days SM rose from very low values to normal values found in infants in their first year. 4) The mean value of SM in ten newborns of diabetic mothers was not significantly different from the mean value of control group. The results do not exclude the possibility of a transplacental transport of SM and the positive correlation between SM levels and birth weight found in this investigation supports the concept that SM plays an important role in fetal growth.     

FIBRINOLYTIC ACTIVITY IN LUNG TISSUE FROM NEONATES WITH HYALINE MEMBRANE DISEASE

The fibrinolytic activity of lung tissue was studied with Todd's histochemical method in a material of 29 newborn infants containing normal lungs, hyaline membrane disease, atelectasis and massive pulmonary haemorrhage. No significant difference was found between a group of hyaline membrane lungs and a group of atelectatic lungs without hyaline membranes. In one case with massive pulmonary haemorrhage the activity was high. Our findings make it questionable whether a lack of plasminogen activator in the lung of infants with hyaline membrane disease is a consistent finding and argue against an alteration of the intrapulmonary fibrinolytic system being of any major importance in the formation of the membranes.     

FIBRINOGEN TURNOVER IN THE PREMATURE INFANT WITH AND WITHOUT IDIOPATHIC RESPIRATORY DISTRESS SYNDROME

Measurement of the elimination of small quantities of ¹²⁵I-fibrinogen (5–15 μCi) demonstrates shortened half-life and higher catabolic rates in premature infants, and particularly in those infants suffering from IRDS compared with adults. Turnover in the adult is 15%, in the premature 25 % and in the premature with IRDS 33 % per day. Equilibrium between intravascular and extravascular fibrinogen is not achieved before the third day of life. Later, elimination is linear. There is a highly significant difference between ^32rT-fibrinogen catabolism in the adult and the premature infant with and without the IRDS between the third and twelfth day. Measurement of activity over various organs demonstrates that slow efiux of ¹²⁵I-fibrinogen into the extravascular compartment causes a continuous fall in plasma activity during the first 2–3 days. In premature infants with IRDS the activity over the lungs rises during the first day of life. These results allow the conclusion that accelerated fibrinogen synthesis in infants with IRDS compensates for losses into the hyaline membranes and intravascular clots and even allows the physiological rise in plasma fibrinogen level during the first three days to take place.     

SOME CHARACTERISTICS OF TRANSCUTANEOUSLY MONITORED OXYGEN PARTIAL PRESSURE IN NORMAL NEWBORNS

The transcutaneous oxygen partial pressure (Ptc_O2) was monitored in 50 healthy, normally and spontaneously delivered newborns. Measurements were performed during the first to fourth day of life. The electrode temperature was 44.5°C. The mean Ptc_O2 level recorded during about 45 min was 9.2 kPa (S.D. 1.4) recorded from the minute-to-minute values. The Ptc_O2 level normally oscillated to a certain extent and the oscillations were closely related to the breathing pattern of the patient. When the patient fell asleep during measurement, the normal oscillating pattern was replaced by a “silent pattern”. During crying, the Ptc_O2 level showed four main reaction patterns. A decrease in the Ptc_O2 level could be observed during breast-feeding. One child, recently fed, vomited a small amount of breast milk after a short period of crying and apparently had a laryngospasm, shown by a sudden drop in the Ptc_O2 level without any other signs of discomfort. The study shows that Ptc_O2(and thus also Pa_O2 very sensitively reacts to changes in activity. This implies that earlier used methods for determination of Pa_O2 might give values that are not representative for the steady state as the sampling method per se might influence the recorded P_O2value.     

不同胎龄儿脐血IGF-1、IGFBP-1及CP水平的变化

目的 了解胰岛素样生长因子-1(IGF-1)、胰岛素样生长因子结合蛋白-1(IGFBP-1)及C肽(CP)对不同胎龄新生儿出生体重的影响。方法 选取不同胎龄的新生儿共76例,按孕周分为≤32、-34、-36、-38、-40、-42周6组,均为适于胎龄儿。分娩时取脐静脉血3 ml,用EIASA法测定血清IGF-1、IGFBP-1及CP。结果 自32周至40周,血清IGF-1、CP逐渐增加,IGFBP-1逐渐下降,各组间差异有显著意义(除34与36周三者比较P>0.05外),但至42周时,IGF-1、CP开始下降,IGFBP-1上升,与40周相比,P<0.05。IGF-1、CP均与胎龄呈中度正相关,而IGFBP-1与胎龄呈高度负相关。结论IGF-1、CP能促进孕晚期胎儿宫内生长,而IGFBP-1则对胎儿生长起抑制作用。因此,营养物质-胰岛素-胰岛素样生长因子系统代谢轴是孕后期调节胎儿生长的重要系统。     

SUPPRESSION OF AEROBIC AND ANAEROBIC FAECAL FLORA IN NEWBORNS RECEIVING PARENTERAL GENTAMICIN AND AMPICILLIN

ABSTRACT. The immediate effect of parenteral antibiotic treatment (gentamicin and ampicillin) on the aerobic and anaerobic faecal flora of 14 infants with suspected or proven neonatal septicaemia was studied. Eight infants of similar gestational and postnatal age were studied for comparison. All control infants showed an abundant growth of both aerobic and anaerobic bacteria as early as the first 2 weeks of life. The treated infants generally had lower counts of aerobic and especially of anaerobic bacteria; in 10 of 16 cultures no anaerobes were isolated. In relation to aerobic strains E. coli dominated in untreated infants and Klebsiella pneumoniae in treated ones.