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Biomedical subjects

F van Bel

Publications and source records attributed to F van Bel.

At least 73 records · Page 4Linked to original sources
PubMed1990

Does very preterm birth impair myelination of the central nervous system?

Myelination of the central nervous system (CNS) can be demonstrated with magnetic resonance (MR) imaging. Myelin formation may be reduced in conditions of neonatal "undernutrition". Very preterm infants have a reduced postnatal growth rate when compared with intrauterine fetuses of the same gestational age. Using MR imaging, we studied qualitative myelination patterns in healthy preterm infants of less than 30 weeks gestation with an optimal nutritional intake and in term infants at 44 weeks postmenstrual age (PMA). At that age, preterm infants had a significantly lower mean body weight than term infants, but mean head circumference did not differ significantly. All preterm and term infants had reached myelination stage M3 (myelin in brainstem, internal capsule, and corona radiata) and M4 (myelin in brainstem, internal capsule, corona radiata, and centrum semiovale). There was no significant difference in myelination stage between the preterm and term infants. We conclude that adequate nutrition in the neonatal period leads to qualitatively adequate myelination of the CNS in very preterm infants.

Central Nervous System↗
PubMed1990

Serum CK-BB activity in the preterm infant and outcome at two and four years of age.

The relationship between serum creatine kinase brain-specific isoenzyme (CK-BB) activity immediately after birth and neurodevelopmental outcome at two and four years corrected age was studied prospectively in 45 preterm infants (less than 34 weeks gestation). Nine infants died during the neonatal period and one was lost to follow-up. Of the 35 children available for follow-up, seven had motor disabilities: four severe diplegia, two mild to moderate diplegia and one hemiplegia. No relationship existed between these motor disabilities and serum CK-BB activity after birth. There seemed to be a relationship between increased serum CK-BB after birth and low scores on the Bayley Scales of Mental Development, but this did not reach statistical significance. At the age of four years, four of the five survivors with high serum CK-BB activity after birth (greater than 25U/L) needed special schooling because of mental retardation. Increased serum CK-BB activity after birth may be associated with delayed mental development, but further study is needed, especially of asphyxiated infants.

Brain Diseases↗
PubMed1989

Cerebral blood-flow velocity during the first week of life of preterm infants and neurodevelopment at two years.

Disturbances in perinatal cerebral perfusion appear to be associated with unfavourable neurodevelopmental outcome. Using transcutaneous Doppler technique, the authors investigated cerebral blood-flow velocity patterns in the anterior cerebral artery (ACA) of an intensive care-unit population of preterm infants during the first week of life. The results were correlated with neurodevelopmental outcome at two years of age. Children with major disability at two years of age had significantly higher pulsatility index (PI) values, mainly increased peak systolic flow velocity (PSFV), compared with children with normal or more favourable outcome. End diastolic flow velocity and area under the velocity curve values of the ACA did not differ between the groups, indicating that cerebrovascular resistance and cerebral blood-flow were not different. It is thought that the higher PI and PSFV values were caused by increased compliance of the vascular bed supplied by the ACA, possibly induced by congestion and oedema of the periventricular white-matter due to ischaemic lesions, which also cause periventricular leukomalacia.

Blood Flow Velocity↗
PubMed1988

The influence of abnormal blood gases on cerebral blood flow velocity in the preterm newborn.

The influence of hypercarbia, combined hypercarbia and hypoxemia, and hypocarbia on cerebral blood flow of preterm infants with a gestational age of less than 34 weeks was investigated by measuring peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and area under the velocity curve (AUVC) of the anterior cerebral artery (ACA) using transcutaneous Doppler technique. Mild and moderate hypocarbia did not change cerebral blood flow velocity. During severe hypercarbia (PaCO2 greater than or equal to 6.7 kPa) significantly lower PI-values were detected, mainly caused by an increase of EDFV, indicating a decreased cerebrovascular resistance and increased cerebral blood flow. A highly significant decrease in PI-values during combined severe hypercarbia and hypoxemia (PaO2 less than 6.0 kPa) was found suggesting that hypoxemia superimposed on hypercarbia strengthens the increase of cerebral blood flow. While the increase of EDFV is thought to be due to carbon dioxide-induced vasodilation of cerebral arterioles, we assume that the accompanied increase of PSFV during combined hypercarbia and hypoxemia is caused by an increase in cardiac output due to hypoxemia which can alter the blood flow velocity wave form of the ACA.

Blood Flow Velocity↗
PubMed1987

Cerebral blood flow velocity pattern in healthy and asphyxiated newborns: a controlled study.

In a controlled study serial determinations of cerebral blood flow velocity using Doppler ultrasound and repeated real-time ultrasonographic- or computerized axial tomographic studies of the brain were performed in 17 (nearly) full-term newborns who experienced perinatal asphyxia and in 17 healthy matched controls during the first week of life. A higher cerebral blood flow velocity was found during the first 4 days of life, indicating a lower cerebrovascular resistance in the asphyxiated infants compared to the control infants. These haemodynamic changes coincided with cerebral oedema and neurological abnormalities. It is speculated that the changes in the cerebral circulation in asphyxiated infants are at least partly caused by cerebral oedema-induced increase of intracranial pressure due to severe perinatal asphyxia. Serial Doppler ultrasound investigations of the brain may be a useful non-invasive method for early detection and follow-up of the consequences of severe perinatal asphyxia.

Asphyxia Neonatorum↗
PubMed1986

Decreased cerebrovascular resistance in small for gestational age infants.

Using a transcutaneous Doppler technique we found a significantly lower cerebrovascular resistance and higher cerebral blood flow velocity indicating vasodilatation and increase of cerebral blood flow in small for gestational age infants compared with appropriate for gestational age infants during the first days of life. We speculate that these findings are due to a continuation of the fetal situation in which chronic hypoxia, mostly caused by pregnancy-induced hypertension, possibly causes a prostacyclin-induced vasodilatation.

Blood Flow Velocity↗
PubMed1986

Monosomy 8p: an easily overlooked syndrome.

Two patients with partial monosomy of the short arm of chromosome 8 are described. Their clinical features were very similar. Comparison with previously reported patients confirms the existence of an 8p- syndrome. The importance of cytogenetic investigations in all infants with major congenital heart defect and facial dysmorphism or microcephaly or both is stressed.

Chromosome Banding↗
PubMed1985

Cerebral edema caused by perinatal asphyxia. Detection and follow-up.

Cerebral edema due to perinatal asphyxia in 2 full-term newborns was detected and monitored with a combination of real time ultrasound, computed tomography, and serial pulsatility-index determinations of the cerebral arteries using Doppler ultrasound. In both babies, real time ultrasound showed small or slitlike lateral ventricles, an increase in diffuse echogenicity and obliteration of normally visible structures in the acute phase suggesting cerebral edema. In the recovery phase a remarkable widening of the ventricles was seen. We also found a relationship between disturbances of consciousness (probably due to cerebral edema) and the pulsatility index. The combination of serial pulsatility-index determinations of the anterior cerebral arteries and real time ultrasound of the brain may in the future be a useful "bedside" method for early detection and follow-up of the cerebral edema.

Asphyxia Neonatorum↗
PubMed1984

Can perinatal asphyxia cause cerebral edema and affect cerebral blood flow velocity?

Cerebral blood flow velocity (C.B.F.V.) was estimated in 49 newborn babies by calculating the pulsatility-index (P.I.) of the anterior cerebral arteries (A.C.A.) using Doppler ultrasound. We studied the changes in P.I. of the A.C.A. in relation to the clinical condition in three full-term babies with evidence of cerebral edema (in one patient proved by autopsy) due to perinatal asphyxia. There was a relation between the level of consciousness and the P.I.; a low P.I. (a sign of arterial vasodilatation) occurred with a low level of consciousness, while higher P.I. values (reduced vasodilatation) were detected when improvement of consciousness occurred. The following explanation is given: cerebral edema causes an increase of intracranial pressure and venous obstruction. The cerebral perfusion decreases and cerebral function changes; stupor and coma occur. By vasodilatation the resistance of the cerebral arteries is lowered; the C.B.F.V. increases in an attempt to restore cerebral perfusion. The vasodilation is reflected in the low P.I. values, as we found in our three patients.

Adult↗
PubMed1982

Tuberculous pericarditis developing during chemotherapy.

A 6-year-old boy with active tuberculosis developed a pericarditis 9 weeks after starting adequate chemotherapy. Although no Mycobacterium tuberculosis was isolated from the pericardial fluid we assume, for several reasons, that the pericarditis was caused by tuberculosis. Consequently, it is important to be aware of possible serious complications even during treatment with adequate antituberculous drugs.

Child↗