Biomedical subjects

A Okken

Publications and source records attributed to A Okken.

At least 37 records · Page 2Linked to original sources

PubMed1996

Measurement of transepidermal water loss in Tanzanian cot-nursed neonates and its relation to postnatal weight loss.

In healthy cot-nursed Tanzanian neonates (n = 92, gestation 26-42 weeks) measurements of trans-epidermal water loss (TEWL) and weight change were performed during the first 24 h after birth at an average ambient humidity of 70% and an environmental temperature of 32 degrees C. Urine production on day 1 (ml/kg per 24 h) was documented for a subgroup of 13 preterm and 8 term infants. In a limited group of preterm infants (n = 5) TEWL measurements, weight and 24 h urine volume measurements were repeated daily for 7 days. Maximum weight loss was determined in 7 preterm (gestational age 30-36 weeks) and 6 term infants. TEWL was estimated by measuring the evaporation rate at three sites of the body using the water vapour pressure gradient method. On day 1, TEWL was highest in the most preterm infants, whereas TEWL and urine production were higher in large for gestational age infants as compared to appropriate for gestational age (AGA) infants of the same gestational age (31-36 weeks). For the whole group, weight loss on day 1 was correlated with TEWL (r = 0.49, p < 0.05). At follow-up TEWL in preterm infants remained almost constant during the first 4 days and decreased after the fourth day, at which time weight gain commenced. Preterm AGA infants (gestational age 24-37 weeks) showed a mean postnatal weight loss of 4.4% of the birth weight, while in term infants this loss was only 2.6%. A reduced postnatal weight loss as compared to Caucasian infants may be explained by a lower water loss during the first days after birth, through both skin evaporation and urine excretion.

Body Water↗

PubMed1996

Insulin-like growth factor-I fails to reverse corticosteroid-induced protein catabolism in growing piglets.

Corticosteroids such as dexamethasone (DEX) increase leucine turnover and oxidation in humans and animals, indicating whole body protein catabolism. Recently, interest has been growing in the use of recombinant polypeptides such as GH and IGF-I in reversing various states of catabolism. The aim of our study was to investigate whether IGF-I reverses corticosteroid-induced protein catabolism in rapidly growing piglets. Also, we wanted to determine whether IGF-I attenuates corticosteroid-induced hyperglycemia. To study these questions, we performed leucine kinetic studies and measured blood glucose in eight piglets under postabsorptive conditions. We did three studies in each piglet: baseline, DEX treatment (5 mg/kg/d for 4 d), and DEX plus IGF-I treatment (25 micro g/kg/h for 6 h). DEX increased leucine turnover by 18 +/- 14% (mean +/- SD, p < 0.05), and oxidation by 132 +/- 64% (p < 0.01) over baseline values. Adding IGF-I to DEX treatment failed to reverse these changes in leucine kinetics. Turnover again increased by 18 +/- 8% (p < 0.01), and oxidation by 107 +/- 68% (p < 0.05) over baseline values. Nonoxidative leucine disposal, an indicator for protein synthesis, did not significantly differ after treatment with DEX or with DEX plus IGF-I. Blood glucose values increased over baseline values after DEX treatment, and approached baseline values after DEX plus IGF-I. We conclude that IGF-I attenuates corticosteroid-induced hyperglycemia, but does not reverse corticosteroid-induced protein catabolism in growing piglets.

Animals↗

PubMed1996

Activation of circulating polymorphonuclear leukocytes in preterm infants with severe idiopathic respiratory distress syndrome.

We have studied activation of circulating polymorphonuclear leukocytes (PMN) in plasma of preterm infants with severe idiopathic respiratory distress syndrome (IRDS group, n = 15) and without IRDS (reference group, n = 15) during the first 5 postnatal days. We have observed lower median PMN counts in the IRDS group than in the reference group from d 2 (1.4 x 10(9)/L versus 4.8 x 10(9)/L in the reference group, p < 0.001) to d 4 to 6 (1.6 x 10(9)/L versus 4.0 x 10(9)/L, p < 0.01). Lower PMN counts in the IRDS infants were accompanied by lower median plasma elastase-alpha1-proteinase inhibitor (PI) concentrations (53.6 ng/mL versus 128.0 ng/mL in the reference group on d 2, p < 0.05). Simultaneously, median elastase-alpha1-PI/PMN ratios of these infants were significantly higher (40.8 ng/10(6) PMN versus 21.8 ng/10(6) PMN on d 2, p < 0.05), indicating activation of circulating PMN. Activation of circulating PMN in the IRDS group is associated with platelet-activating factor (PAF) release and complement activation from within 6 to 12 h of birth but not with release of tumor necrosis factor-alpha. PAF release was represented by significantly reduced inhibiting capacity (58% of normal human plasma, p < 0.01) and complement activation by higher median plasma C3a des-Arg concentrations (1680 ng/mL versus 325 ng/mL in the reference group, p < 0.001). We conclude that circulating PMN are activated in preterm infants with severe IRDS, which might be caused by systemic PAF release and complement activation. This activation process may play a role in the pathogenesis of the IRDS by influx of activated PMN into the lungs.

Complement C3a↗

PubMed1996

Leakage of protein into lungs of preterm ventilated rabbits is correlated with activation of clotting, complement, and polymorphonuclear leukocytes in plasma.

We investigated whether leakage of protein in lungs of preterm ventilated rabbits of 28- and 29-d gestational age is correlated with activation of clotting, complement, and polymorphonuclear leukocytes (PMN) in plasma. We found signs of systemic activation of clotting, complement and PMN in ventilated 28-d gestational age rabbits, as indicated, respectively, by increased median plasma fibrin monomer concentrations (83 versus 40% of normal adult rabbit plasma in nonventilated 28-d gestational age rabbits, p < 0.01), decreased median plasma CH50 activity (112 versus 122 U/L in nonventilated 28-d gestational age rabbits, p < 0.05), and increased median plasma beta-glucuronidase concentrations (159 versus 97% of maximal activated adult rabbit plasma in nonventilated 28-d gestational age rabbits p < 0.05). We did not find signs of systemic activation in the ventilated 29-d gestational age group. Higher median total protein concentrations in alveolar wash of the ventilated 28-d gestational age rabbits (2.7 versus 1.3 mg/mL in the nonventilated rabbits. p < 0.01) indicated protein leakage into the lungs, and this protein leakage was more pronounced in the lungs of ventilated 28-d gestational age rabbits than in those of ventilated 29-d gestational age rabbits (2.1 mg/mL, p < 0.01). The total protein concentration in the alveolar wash of all 28-d gestational age rabbits was correlated with the concentration of fibrin monomers (p = 0.51, p = 0.035) and beta-glucuronidase (p = 0.61, p = 0.011), and the CH50 activity (p = -0.73, p = 0.002) in plasma. We conclude that leakage of protein in lungs of preterm ventilated rabbits of 28-d gestational age is correlated with activation of clotting, complement, and PMN in plasma. This activation process may contribute to lung injury by intravascular and intraalveolar deposition of fibrin and formation of proteinaceous edema.

Animals↗

PubMed1995

N-methyladrenaline: age-dependent urinary excretion, perinatal organ content and relation with 'classical' catecholamines.

Using high performance liquid chromatography with electrochemical detection we determined free dopamine, noradrenaline, adrenaline and N-methyladrenaline in: (1) urines from newborns (n = 32), children (n = 45) and adults (n = 19) and (2) adrenals, organ of Zuckerkandl, dorsal roots and perirenal brown adipose tissue from deceased fetuses (n = 2), very premature (n = 6) and term (n = 2) newborns and infants (n = 2). Data from children and adults showed that contributions of adrenaline and N-methyladrenaline to the sum of urinary free catecholamines increase with age. Relative amounts of adrenaline and N-methyladrenaline increased in both adrenal and extra adrenal chromaffin tissues from late gestation up to several months of postnatal life. Increase of adrenal N-methyladrenaline content follows endocrine maturation of the medulla, phenylethanolamine-N-methyltransferase induction and subsequent adrenaline synthesis. Relative amounts of N-methyladrenaline in extra adrenal chromaffin tissue increase in a period that is associated with its regression. Further investigations are necessary to elucidate the function and possible clinical chemical usefulness of N-methyladrenaline.

Adrenal Glands↗

PubMed1995

Erythrocyte and plasma cholesterol ester long-chain polyunsaturated fatty acids of low-birth-weight babies fed preterm formula with and without ribonucleotides: comparison with human milk.

We investigated whether a regular formula for premature infants (pre) supplemented with ribonucleotides (pre+RN) raises erythrocyte and plasma cholesterol ester (CE) long-chain polyunsaturated fatty acids (LCPUFAs) of low-birth-weight babies (< or = 2.50 kg) compared with their breast-fed counterparts. From days 11 to 42, 31 babies received the pre formula and 37 received pre+RN. Eleven breast-fed babies served as a reference group. Erythrocytes and CE fatty acids were determined on days 11, 21, and 42. There were no differences in the courses of erythrocytes and CE fatty acids between pre formula-fed and pre+RN-fed babies. On day 42, formula-fed babies had lower erythrocytes and CE n-3 and n-6 LCPUFAs compared with breast-fed babies. Subdivision into gestational age- and body weight-matched subgroups gave similar results. RN supplementation does not augment the erythrocyte and CE LCPUFA status of formula-fed babies.

Adult↗

PubMed1995

Increased plasma concentrations of interleukin-1 receptor antagonist in neonatal sepsis.

Newborns are prone to severe infections and sepsis. Cytokines such as tumor necrosis factor-alpha and IL-1 beta play a major role in the initiation of the host response to infections. IL-1 receptor antagonist (IL-1ra) is a naturally occurring antagonist of IL-1 beta. We hypothesized that low IL-1ra plasma concentrations might contribute to the high morbidity and mortality of neonatal sepsis. We studied IL-1ra plasma concentrations during neonatal sepsis. Eleven newborns with severe infection or sepsis, 28 newborns suspected as having sepsis, and eight healthy newborns were enrolled in the study. IL-1ra plasma concentrations proved to be increased in the newborns with severe infections or sepsis (5635 +/- 411 ng/L) versus the concentrations in the suspected group (2597 +/- 433 ng/L) and the control group (273 +/- 88 ng/L) (p < 0.001). After the start of antibiotic therapy, the IL-1ra plasma concentrations remained high during the first 16 h. The IL-1 beta plasma concentrations were increased in the group with a proven infection (78 +/- 27 ng/L) versus the suspected group (37 +/- 7 ng/L) (p < 0.05). Interestingly, the mean Il-1RA plasma concentration is a factor 50-100 higher than the IL-1 beta plasma concentrations. We conclude that IL-1ra in newborns is produced in an amount equal to that in adults. An inadequate IL-1ra response does not seem to contribute to the increased morbidity and mortality of neonatal sepsis.

Female↗

PubMed1995

Aspirin versus indomethacin treatment of patent ductus arteriosus in preterm infants with respiratory distress syndrome.

Indomethacin (Indo) is commonly used for treatment of patent ductus arteriosus (PDA) but has renal failure as a main side effect. Aspirin (ASA) is an alternative, but there are no controlled trials on its efficacy. We randomly assigned 75 premature infants suffering from respiratory distress syndrome (RDS) (mean gestational age: 29.6 +/- 2.5 wk, mean birth weight: 1295 +/- 464 g) (+/- SD) and on artificial ventilation at the start of the study (mean: 3.4 d of life), to either Indo (3 x 0.2 mg/kg/12 h) or ASA (4 x 15 mg/kg/6 h). PDA and degree of shunting were evaluated by echocardio-Doppler; side effects were carefully recorded. PDA closed in 35/38 patients from the Indo group (92%) and in 16/37 patients from the ASA group (43%) (p < 0.0001). Nineteen patients needed further treatment with Indo or surgery (17 in the ASA group and 2 in the Indo group). The only side effect observed was a decrease of uresis in the Indo group during 4 d post treatment (p < 0.01). Closing of PDA was positively correlated with gestational age, but not with time of starting Indo/ASA or grade of shunting. We conclude that ASA is not as effective in closing PDA as Indo, but has no adverse effect on uresis.

Aspirin↗

PubMed1994

Kidney size in infants of tightly controlled insulin-dependent diabetic mothers.

The aim of this study was to evaluate the influence of insulin-dependent diabetes mellitus in pregnant women on the kidney size of their infants. We measured kidney length in the first week of life using ultrasonography in 20 infants of tightly controlled insulin-dependent diabetic mothers and 20 healthy newborn controls, matched for birth weight. In the infants of diabetic mothers, the left kidney length ranged from 3.6 cm to 6.0 cm (4.2 cm +/- 0.5 cm, mean +/- SD). The right kidney length ranged from 3.3 cm to 4.9 cm (4.0 cm +/- 0.4 cm). In the control infants the left kidney length was 3.3 cm to 5.4 cm (4.3 cm +/- 0.6 cm), and the right kidney length was 3.4 cm to 5.3 cm (4.2 cm +/- 0.5 cm). There was no statistically significant difference in right or left kidney length between the two groups. We conclude that in this group of tightly controlled diabetic mothers, the diabetic state does not influence kidney size in their infants.

Birth Weight↗

PubMed1994

Diagnostic value of plasma levels of tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) in newborns with sepsis.

The aim of this study was to examine if TNF alpha and IL-6 plasma levels could be of value in diagnosing neonatal sepsis. Tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) plasma levels were determined in 15 newborn infants with confirmed sepsis (group I), 18 with suspected sepsis (group II) and 22 control infants (group III). In 33 newborns, initially suspected of having sepsis (groups I and II), a positive test result for plasma concentration of TNF alpha (> 70 pg/ml) had a sensitivity of 73% and a specificity of 94%. A positive test result for IL-6 (> 500 pg/ml) had a sensitivity of 80% and a specificity of 78%. When plasma levels of TNF alpha and IL-6 were combined for the diagnosis of neonatal sepsis, a positive test result for both tests had a sensitivity of 60% and a specificity of 100%. When both tests are positive the diagnosis of neonatal sepsis is almost certain (likelihood ratio = infinity). The combination of TNF alpha and IL-6 determinations appears to be a good predictor of neonatal sepsis.

Biomarkers↗

PubMed1994

Activation of the plasma clotting, fibrinolytic, and kinin-kallikrein system in preterm infants with severe idiopathic respiratory distress syndrome.

We studied the activation pattern of clotting, fibrinolysis, and kinin-kallikrein during the first 5 d of life in 10 preterm infants with signs of severe idiopathic respiratory distress syndrome (IRDS) after birth (IRDS group) and in 12 healthy preterm infants (reference group). We found systemic activation of clotting, fibrinolysis, and kinin-kallikrein in the IRDS infants within 12 to 24 h of birth, represented by increased median thrombin-antithrombin III complex formation (90 ng/mL versus 10 ng/mL in the reference group, p < 0.05), increased mean tissue-type plasminogen activator plasma concentrations (11.8 ng/mL versus 3.5 ng/mL in the reference group, p < 0.05), and increased mean plasma kallikrein activity (182.6% versus 162.0% of maximal activated human plasma in the reference group, p < 0.05), respectively. Clotting activation was accompanied by a significant decrease of the platelet count. Clotting and fibrinolytic activity decreased in the IRDS group during the first 2 to 3 d of life. Kinin-kallikrein activation was accompanied by decreased plasma kallikrein inhibitor activity values and did not change throughout the study period. Plasma factor XII activity was not significantly increased in the IRDS infants during the first 2 d of life but did significantly increase thereafter. The cause of simultaneous activation of clotting, fibrinolysis, and kinin-kallikrein in our IRDS infants has not yet been clarified. However, this activation process may contribute to lung injury such as that described in the adult respiratory distress syndrome.

Antithrombin III↗

PubMed1994

Application of transcutaneous microdialysis and continuous flow analysis for on-line glucose monitoring in newborn infants.

The combination of a transcutaneous microdialysis probe and continuous flow analysis was tested for continuous glucose monitoring in eight newborn infants who were fed intravenously. The probe was placed on the skin, which was first stripped with cellophane tape to increase the skin permeability. The skin was stripped until the transepidermal water loss reached values greater than 80 gm/m2/hr. Dialysate concentrations were monitored for 165 minutes while the blood glucose concentrations were manipulated by changing the infusion rate of glucose. Blood glucose concentration was linearly related to the dialysate concentration. Because the dialysate/blood glucose ratio varied among the infants, the dialysate concentration was calibrated to estimated blood values with a single-point and a multiple-point calibration method. The latter method yielded more accurate estimates of the blood values. We conclude that transcutaneous microdialysis may be used for glucose monitoring in newborn infants.

Blood Glucose↗

PubMed1993

[Marked variations in phototherapy policy for neonatal jaundice in Dutch centers].

OBJECTIVE: To determine what guidelines are used in Dutch hospitals in the management of neonatal hyperbilirubinaemia. DESIGN: Descriptive. MATERIAL AND METHOD: Paediatricians in 63 hospitals were sent a standard guideline diagram of phototherapy management and asked to describe how their management differed. The 10 neonatal intensive care units in the Netherlands were asked to send their phototherapy guidelines in more detail. RESULTS: Thirty-four hospitals (54%) and the 10 neonatal centres (100%) responded. The data obtained showed no general agreement; several different guidelines were used, notably with respect to the serum bilirubin concentration levels and the number of postnatal hours. CONCLUSION: We recommend that consensus should be reached on the use of phototherapy. A more restricted use of phototherapy probably would save costs without loss of quality.

Age Factors↗

PubMed1993

Maternal haemolysis, elevated liver enzymes and low platelets syndrome: specific problems in the newborn.

To evaluate the effects of maternal haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome on the fetus and neonate we retrospectively investigated the outcome of 87 pregnancies. All women showed thrombocytopenia, elevated liver enzymes and haemolysis. None of them died. Nine infants were stillborn (9.9%). Of the 82 liveborn infants, 66 were delivered by caesarean section. Median gestational age of the liveborn infants was 32.6 weeks, mean birth weight was 1576 g +/- 699 g (mean +/- SD). Of these infants, 44% were small for gestational age. Perinatal asphyxia rate was 21.6%. Nine infants died in the 1st week after birth. Complications during admission included neonatal respiratory disease (43.2%), hyperbilirubinaemia (44.7%), persistent ductus arteriosus (16.2%), thrombocytopenia (34%) and hypoglycaemia (16.2%). Artificial ventilation was necessary in 37 infants. Mean duration of admission was 51 days. HELLP syndrome is associated with poor perinatal outcome; the incidence of caesarean section is high and there is an increased risk for preterm birth and growth retardation. No specific neonatal pathology due to maternal HELLP syndrome was found.

Female↗

PubMed1993

Non-immune hydrops fetalis and bilateral pulmonary hypoplasia in a newborn infant with extralobar pulmonary sequestration.

Extralobar pulmonary sequestration was found in a newborn premature infant that presented with non-immune hydrops fetalis, massive bilateral hydrothorax and polyhydramnios in utero. The baby died of severe respiratory insufficiency 15 h after birth. Postmortem examination revealed distended lymphatic vessels in the sequestered lung tissue probably due to impeded lymph drainage. We suggest that not extralobar pulmonary sequestration itself but a subsequent massive unilateral hydrothorax due to severe obstruction of lymph drainage was the cause of the non-immune hydrops fetalis, pulmonary hypoplasia and polyhydramnios. If these symptoms are diagnosed before delivery, a search for extralobar pulmonary sequestration is indicated.

Adult↗

PubMed1993

Monitoring of glucose and lactate using microdialysis: applications in neonates and rat brain.

Methods for the continuous in vivo monitoring of glucose and lactate were applied in man for studies of peripheral metabolism and, in rats, for cerebral examinations. Lactate ('lactography') and glucose were continuously measured by the enzyme formation of NADH or NADPH using appropriate dehydrogenases. Glucose was monitored with a transcutaneous probe in neonates or with probes placed directly in the brain of conscious rats. In neonates a high correlation was seen between the dialysate and blood levels. A correlation between the age of the neonates and glucose levels in the dialysate was found, suggesting that the thickness of the skin determined to a large extent the diffusion of glucose into the probe. In the rat brain transient changes in the extracellular glucose levels were seen during electroconvulsive shock and immobilization stress. Lactography was applied to striatum or hippocampus during stress, electroconvulsive shock or systemic and intracerebral drug applications. Extracellular lactate decreased during intracerebral deoxyglucose infusion and was increased by excitatory neuronal activity and the presence of glucose in the perfusion medium. The present studies show that microdialysis in combination with continuous flow analysis can be used to study metabolic trafficking in vivo and in clinical studies. In the brain both neurons and glia may contribute to extracellular lactate levels.

Animals↗

PubMed1993

Immune response after surfactant treatment of newborn infants with respiratory distress syndrome.

We examined the sera of 68 newborn infants with respiratory distress syndrome; 49 were treated with a natural porcine-derived surfactant preparation and 19 were controls. Serum of the patients was collected before, 3 weeks and 3 months after surfactant treatment. To detect any antibody that had been raised, we applied diluted serum of the babies in an indirect immunoperoxidase staining technique on frozen pig lung tissue specimens. With light microscopy an immune response could be appreciated as a brown reddish deposit in the porcine lung tissue specimens in 4 out of the 49 surfactant-treated and not in the control babies.

Animals↗

PubMed1993

Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 plasma levels in neonatal sepsis.

Tumor necrosis factor-alpha, IL-1 beta, and IL-6 are thought to be involved in the pathogenesis of sepsis with gram-negative bacteria. We studied these cytokines during neonatal sepsis with mainly gram-positive bacteria. Ten newborns with clinical sepsis and 22 healthy controls were enrolled in the study. TNF alpha plasma levels proved to be increased in the newborns with sepsis up to 560 +/- 234 pg/mL (ng/L) versus 36 +/- 4 pg/mL (ng/L) in the control group (p < 0.005), whereas IL-6 plasma levels in newborns with sepsis were 79.700 +/- 37.500 pg/mL (ng/L) versus 55 +/- 28 pg/mL (ng/L) in the control group (p < 0.01). The IL-1 beta plasma levels were only slightly elevated in the group newborns with sepsis [up to 18 +/- 5 pg/mL (ng/L) versus 7 +/- 1 pg/mL (ng/L) in the control group (p < 0.01)]. After the start of therapy with antibiotics, both TNF alpha and IL-6 plasma levels decreased concomitantly with the improvement of the clinical situation within 2 d. These data confirm the abundant presence of TNF alpha and IL-6 during neonatal sepsis, whereas IL-1 beta appeared to be present in small amounts only. Nevertheless, the IL-1 beta but not the TNF alpha plasma level appeared to correlate inversely with the decrease in diastolic tension as standardized according to birth weight (R = 0.66, p = 0.04). TNF alpha, IL-1 beta, and IL-6 were not correlated with any febrile response in the group with sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗