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Biomedical subjects

G B Stoelinga

Publications and source records attributed to G B Stoelinga.

At least 37 records · Page 2Linked to original sources
PubMed1991

Influences on heart rate variability in spontaneously breathing preterm infants.

To investigate the influence of maturational and physiological factors on heart rate variability in spontaneously breathing very preterm infants (n = 29) a multiparametric study was performed during the first 3 days of life in infants born at a gestational age below 33 weeks. Four times a day, RR-intervals, respiration curve and rate, transcutaneously measured blood gases and observed body movements were recorded while the infants were asleep. All data were stored simultaneously in a micro-computer. Non-invasively measured blood pressure and patency of the ductus arteriosus were documented as well. Four sets of short- (STV) and long term variability (LTV) indices were calculated. Both STV and LTV appeared to be significantly influenced by conceptional and postnatal age in the appropriate for gestational age infants. LTV was influenced by the behavioural state and body movements. During state coincidence 2 ('active sleep') LTV was influenced by respiratory rate and the variations in transcutaneous PO2. An effect of blood pressure or ductus patency could not be demonstrated.

Age Factors↗
PubMed1991

The influence of respiratory distress syndrome on heart rate variability in very preterm infants.

In a multi-parametric study the influence of pathological neonatal conditions on heart rate variability was investigated in 60 preterm infants born at a gestational age below 33 weeks. Measurements were performed during the first 3 days of life. Four times a day, RR-intervals, respiration curve and rate, transcutaneously measured blood gases and observed body movements were recorded while the infants were asleep. All data were stored simultaneously in a micro-computer. Severity of respiratory distress syndrome (RDS), patency of ductus arteriosus and periventricular haemorrhage were documented as well. Four sets of short- (STV) and long-term variability (LTV) indices were calculated. Severe RDS was associated with a significant decrease in LTV. The influence of RDS on LTV persisted after correction for conceptional age, postnatal age, behavioural state and variations in respiratory rate and in transcutaneous PO2. Infants with a symptomatic patent ductus arteriosus had lower LTV than controls with the same severity of RDS. STV was predominantly influenced by postnatal and conceptional age, and tended to be lower in infants with periventricular haemorrhage.

Age Factors↗
PubMed1990

The influence of physiological parameters on long term heart rate variability in healthy preterm infants.

The instantaneous heart rate shows a variation around the mean heart rate caused by cardioregulatory mechanisms which are mediated through the sympathetic and vagal autonomic nervous system. To gain more insight into the influence of physiological parameters on neonatal heart rate variability a study was performed in four healthy preterm newborns during the first five days of life. Instantaneous heart rate, respiration rate, transcutaneous pO2, blood pressure and behaviour were recorded during 40 minutes four times a day. Long term heart rate variability was calculated as the difference between p95 and p5 of instantaneous heart rate values sampled during three minutes. A clear relationship between long term variability and age (maturity of the autonomic nervous system), respiration rate (respiratory sinus arrhythmia or a tidal volume mediated effect) and behaviour (increase of sympathetic tone during REM sleep) was found. No influence of blood pressure, heart rate, and transcutaneous pO2 within physiological ranges could be detected. The relative influence of the different physiological parameters on heart rate variability has to be established before the value of heart rate variability as a monitoring tool in neonatal intensive care can be investigated.

Age Factors↗
PubMed1989

Assessment of the orifice diameter by a multigated pulsed Doppler system in children with congenital semilunar valve stenosis.

This study investigated whether the jet diameter measured by a multigated pulsed Doppler system could be used to assess the severity of valve disease in children with pulmonary (n = 11) or aortic (n = 4) valve stenosis. The results obtained were compared with those obtained at cineangiography and at operation. Multigated pulsed Doppler examination of a stenosed valve showed a region of relatively high velocities in the velocity profile (jet flow). There was good agreement between the diameter of the disturbed region on the Doppler echocardiogram and the diameter of the jet on the lateral angiocardiogram. In severe valve stenosis the agreement between the valve diameters measured by multigated pulsed Doppler and at operation was also good. In less severe valve stenosis Doppler measurements systematically underestimated the valve diameter at operation. It is likely that the functional opening of a semilunar valve is a more relevant estimate of the degree of stenosis than the anatomical measurement of the orifice. The findings of this study indicate that multigated pulsed Doppler systems are useful in the noninvasive diagnosis of stenotic valve disease.

Aortic Valve↗
PubMed1987

Chromosome studies in IgA-deficient patients.

Chromosome analysis was performed in 17 children with IgA-deficiency. In two patients a constitutional structural chromosome abnormality was found. A ring chromosome 22 was seen in one, while in the other a mosaicism of ring chromosome 18/18p+ was observed. Both patients were mentally retarded and showed distinct congenital defects. From ten asymptomatic patients, spontaneous as well as X-ray-induced chromosome instability was investigated. There was no increased spontaneous instability, and also after irradiation the induced chromosome damage was within normal control levels. A relationship between IgA-deficiency and X-ray hypersensitivity, as might be suggested by the frequently occurring coincidence of radiosensitivity and IgA-deficiency in ataxia telangiectasia patients, is not established.

Adolescent↗
PubMed1986

The central auditory conduction at term date and three months after birth. II. Auditory brainstem response.

This communication describes the results of auditory brainstem responses (ABRs) obtained in 25 healthy mature newborns with a follow-up at 3 months of age. The combination of ipsi- and contralateral recordings, the intensity series and the comparison with the composite group averages are useful for the identification of the separate ABR components. Differences between the records after right or left ear stimulation were not observed. Comparing our data with those obtained by others, we conclude that the interpeak latency differences (IPLDs) offer a more consistent measure of ABR latency values than the peak latencies measured from stimulus onset. The simultaneously recorded ABRs ipsi- and contralateral to stimulation show both at term, and at 3 months, an equal central conduction time. The ABR II-V complex shows contralaterally a significant shift compared with the ipsilateral II-V complex. The significant latency changes observed between term and at 3 months are due mainly to the latency decrease in the II-III IPLD.

Age Factors↗
PubMed1986

The central auditory conduction at term date and three months after birth. III. Middle latency responses (MLRs).

Middle latency responses (MLRs) were obtained in 25 healthy newborns with a follow-up recording at 3 months in all but three. A four-channel recording provided topographic information. Linkage of the ear references reduced the myogenic contamination of the recordings. P0 and Na proved to be the most consistent components in the sinusoidal MLR wave sequence. Topographic differences suggest a generation of P0 and Na contralateral to stimulation. A significant latency decrease was found for P0 and na between term and 3 months. The most important latency and amplitude changes may occur before term date and immediately thereafter. The MLRs are the link between the auditory brainstem responses (ABRs) and the auditory cortical responses (ACRs), and it may be possible to use them for recordings in newborn infants. They provide information about the generation of specific components as well as regarding the auditory afference in the stimulus propagation between the brainstem and the cortical auditory areas.

Auditory Cortex↗
PubMed1986

The central auditory conduction at term date and three months after birth. IV. Auditory cortical responses.

Auditory cortical responses (ACRs) were recorded in 25 healthy mature newborns with a follow-up at 3 months. The waveform, latencies and amplitudes for the ACRs for this time period are studied. Topographic differences between the central and central-temporal derivations and changes between term and 3 months are found with respect to latencies and amplitudes for different peaks and troughs. The ACRs, obtained as a part of a protocol covering the entire auditory afference, offer consistent parameters, which can be used to study developmental neurophysiological properties of audition and which are potential diagnostic tools for the detection of deviant sensory or mental development.

Auditory Cortex↗
PubMed1985

The application of evoked potentials in the diagnosis and follow-up of children with intracranial tumors.

Somatosensory and brainstem auditory evoked potentials (SSEPs and BAEPs) provide sensitive measures of the central conduction functions of the auditory and somatosensory input systems at different levels of the central nervous system. The contribution of SSEPs and BAEPs in the primary diagnosis and follow-up of 26 children with infra- and supratentorial tumors were reviewed. The SSEPs, especially the specific complex, showed a latency increase in patients with supratentorial and brainstem mass lesions involving directly or distantly the somatosensory tracts. The BAEPs were sensitive for supratentorial pressure effects and for local and distant posterior fossa tumor effects. In the follow-up of children, evoked potentials offer a good method of detecting tumor recurrence, whereas neuroradiological procedures may be obscured by surgical or radiation artifacts.

Adolescent↗
PubMed1985

The central auditory conduction at term date and three months after birth. I. Composite group averages of brainstem (ABR), middle latency (MLR) and auditory cortical responses (ACR).

We are investigating the maturation of auditory evoked responses, as a potential diagnostic tool for the neurological examination of premature infants at the Intensive Care Unit for Prematures. In this communication we report the group composite averages of the BMC-ARs in a group of 25 mature and healthy newborns with a follow-up at 3 months of age. The ABRs showed a remarkable variability in wave I latency, with a relatively stable I-V central conduction time (CCT) of the brainstem. The ipsilateral II-V CCT does not differ appreciably from the contralateral II-V CCT. The MLR components NoPoNa and Nb, Nc, Nd are easy to identify in the group averages. Voltage asymmetry between stimulated versus non-stimulated side is slight but persistent in the newborn period as well as at 3 months of age. The group averaged ACRs, show an early complex within the latency reach of 100 ms and a slow W-shaped late complex, most distinct at 3 months. The results indicate that the protocol as applied constitutes a tool for the testing of conduction function of the auditory afference in newborns, even beyond the level of the brainstem. Group averaging offers a method to determine the intragroup stability of evoked potentials under investigation.

Acoustic Stimulation↗
PubMed1984

Surgery and radiation therapy in the management of craniopharyngiomas.

Twenty-nine patients with histologically confirmed craniopharyngioma were treated from 1960 to 1978, inclusive. Twelve patients were below the age of 15 years, the remaining were adults. Seventy-five percent (9/12) of the patients below the age of 15 showed increased intracranial pressure at presentation and 58% (7/12) showed visual disturbances. In the adult group, 47% (8/17) presented with increased intracranial pressure and 88% (15/17) with visual disturbances. Hormonal, mental and behavior changes were almost equally distributed in both age groups. All patients underwent craniotomy, with subtotal resection of the tumor. Three adults died of postoperative complications (10%), of whom two died of pulmonary emboli and one of cerebral hemorrhage. Of the remaining 26 patients, 13 received immediate postoperative radiotherapy to a total dose of 50.0 to 56.0 Gy, in a target volume including the sellar and parasellar region during an overall treatment period of five to six weeks. All patients were evaluable with a minimum follow-up of four years since they finished their treatment or until death. The five-year recurrence-rate in the group that did not receive postoperative radiation therapy was 45% (5/11 patients) and the five-year rate of death of disease in this group was 27% (3/11 patients). For the group that received immediate postoperative radiation therapy the five-year recurrence-rate was 11% (1/9 patients) and no death of disease was observed in this group. This difference between the two groups was not significant. The corresponding 10-year rates were 71% (5/7 patients) for recurrence and 57% (4/7 patients) for death of disease in the group without, and in the group with immediate postoperative radiation therapy the rate was 25% (2/8 patients) for recurrence and 0 for death of disease. This difference turns out to be significant. Critical analysis of the morbidity in patients surviving after treatment showed no adverse effect on the visual or endocrine status of the group that received postoperative irradiation. It is concluded that in the management of patients with craniopharyngiomas, postoperative irradiation after subtotal resection improves the prognosis of the patient and does not add to visual or endocrine morbidity.

Adolescent↗
PubMed1984

[The wrong sex].

Sexual ambiguity may cause problems in determining the sex, in which a child would be reared. Three case histories of such patients are presented, in which the initial diagnosis proved to be incorrect. Arguments which lead to the ultimate choice of the sex of the child ranged from strict medical, to psychosocial and even cultural considerations. A simple classification of causes of ambiguous external genitalia is used both for investigation and management of these patients. Only expert examination shortly after birth allows an early and definite decision, avoiding more serious problems in later life.

Adrenal Hyperplasia, Congenital↗