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Biomedical subjects

H Oosting

Publications and source records attributed to H Oosting.

35 records · Page 2Linked to original sources
PubMed1994

Effect of fetal brainsparing on the early neonatal cerebral circulation.

The effect of antenatal brainsparing on subsequent neonatal cerebral blood flow velocity (CBFV) was studied in very preterm infants. CBFV was determined, using a pulsed Doppler technique, both in the fetal and neonatal period. Neonatally, blood pressure and transcutaneous carbon dioxide tension (TcPCO2) was monitored simultaneously; daily cranial ultrasound examinations were performed. In infants with evidence of brainsparing a higher mean value of CBFV and a different pattern of changes of CBFV during the first week of life was demonstrated compared with infants with normal fetal cerebral haemodynamics. No differences were found in blood pressure and TcPCO2. The incidence of intracranial haemorrhages and of ischaemic echo-dense lesions was also the same for both groups. In a multivariate statistical model gestational age, antepartum brainsparing, and TcPCO2 all contributed significantly in explanation of variation in CBFV. It is speculated that a different setting of cerebral autoregulation related to differences in gestational age or to brainsparing might explain the difference in changes found in neonatal CBFV.

Blood Flow Velocity↗
PubMed1993

Intra-observer and inter-observer reliability of the pulsatility index calculated from pulsed Doppler flow velocity waveforms in three fetal vessels.

OBJECTIVE: Study of the intra observer and inter observer reliability of the pulsatility index, calculated from pulsed Doppler recordings of three fetal vessels. DESIGN: Flow velocity waveforms (FVW) were recorded from the umbilical artery, the fetal descending aorta and the fetal internal carotid artery. Intra-observer reliability was assessed in six fetuses; ten repeated measurements were performed by one observer. Inter-observer reliability was studied in 14 fetuses; two observers performed two repeated measurements in each fetus. SETTING: A tertiary referral hospital. SUBJECTS: High risk pregnancies with a gestational age ranging from 29 to 42 weeks. MAIN OUTCOME MEASURES: Analysis of variance with repeated measurements and a graphical method were used for data analysis. Intra-observer repeatability was expressed as Intraclass Correlation Coefficient (IntraCC). Inter-observer agreement was expressed as Interclass Correlation Coefficient (InterCC). RESULTS: IntraCC for umbilical artery, descending aorta and internal carotid artery were 0.91, 0.78, and 0.54, respectively. InterCC values for these vessels were 0.39, 0.45 and 0.34, respectively. No systematic differences between the two observers except for the fetal descending aorta, were apparent. IntraCC decreased remarkable when fetuses with absent end diastolic velocities were excluded from the analysis. CONCLUSION: The pulsatility index (PI) used for fetal measurements has a poor reliability. This is of serious concern when clinical use of FVW measurements is considered as a diagnostic tool.

Aorta, Thoracic↗
PubMed1992

Platelet aggregation, disc haemorrhage and progressive loss of visual fields in glaucoma. A seven year follow-up study on glaucoma.

Platelet aggregation in vitro, deterioration of visual field defects (VFD) and the prevalence of disc haemorrhages (DH) were assessed in 49 patients with primary open angle glaucoma (POAG) and compared with the findings for 67 individuals with suspected glaucoma (GS) in a seven-year follow-up study (range 5.8 to 8.2 years). The percentage patients with spontaneous platelet aggregation (SPA) was higher for POAG patients with visual field deterioration (60%) than both POAG patients without progressive loss of visual fields (12.5%; P less than 0.005) and those with suspected glaucoma (22.4%; P less than 0.005). The occurrence of DH was higher among POAG patients with progressive loss of visual field (28%) compared to the GS group (8.4%; P less than 0.025) and the group of patients consisting of POAG patients without deterioration of VFD and GS (9.9%; P less than 0.05). DH also occurred more often in patients with low tension glaucoma (41.6%) than in the remaining POAG patients (13.5%; P less than 0.05). No relation between the patients with SPA and the patients with DH was observed.

Adult↗
PubMed1992

Fetal and neonatal cerebral circulation: a pulsed Doppler study.

We studied the relation between the fetal cerebral circulation and changes in the cerebral circulation directly after birth. With a combined real time ultrasound/pulsed Doppler technique flow velocity waveforms from the fetal umbilical- and carotid-circulation were monitored. Pulsatility Index (PI) was computed and the ratio between Umbilical PI and Carotid PI was calculated. Flow velocity waveforms of the cerebral circulation before birth were related to anterior cerebral artery flow velocity waveforms recorded immediately after birth. The study shows that changes in flow velocity waveforms associated with the intra uterine brain-sparing effect are related to poor obstetrical outcome. Furthermore is shown that the brain-sparing effect in the fetal period is associated with higher PI values in the cerebrovascular circulation in the neonatal period. It is suggested that changes in these PI values, representing changes in cerebrovascular resistance, might be indicative of cerebral ischemia in the neonate.

Carotid Arteries↗
PubMed1991

An increase in plasma cholesterol independent of thyroid function during long-term amiodarone therapy. A dose-dependent relationship.

OBJECTIVE: To determine whether long-term amiodarone treatment is associated with a rise in plasma cholesterol, and, if so, to analyze its relation with thyroid function. DESIGN: Consecutive entry trial, including cardiac patients who initiated amiodarone medication but excluding those with abnormal thyroid function (defined as peak thyroid-stimulating hormone [TSH] response to thyrotropin-releasing hormone [TRH] less than 2.8 or greater than 22.0 mU/L) either before or during amiodarone treatment. PATIENTS: Twenty-three patients who remained euthyroid were studied. INTERVENTION: Oral administration of amiodarone (mean duration of treatment, 17 months; range, 6 to 30 months). MEASUREMENTS: Fasting plasma lipids, thyroid hormones, and peak TSH to TRH values were recorded before and every 6 months during amiodarone treatment. RESULTS: Plasma cholesterol gradually increased from 5.1 +/- 0.2 mmol/L before treatment to 6.9 +/- 0.8 mmol/L after 30 months of amiodarone medication (P less than 0.001); the peak TSH response to TRH did not change. When age- and sex-specific reference values were applied, 30% of the patients had cholesterol values above the 75th percentile before treatment; this number rose to 69% after 2 years of treatment. The rise in plasma cholesterol was associated with an equal increase in apoprotein B. Plasma cholesterol was not related to the daily dose of amiodarone or to plasma concentrations of amiodarone, desethylamiodarone, thyroxine (T4), triiodothyronine (T3), or reverse triiodothyronine (rT3). Linear regression analysis indicated a positive relation between plasma cholesterol and the cumulative dose of amiodarone (r = 0.25, P less than 0.05). CONCLUSION: Long-term amiodarone treatment is associated with a dose-dependent increase in plasma cholesterol that is independent of thyroid function.

Adult↗
PubMed1991

Dynamic loading of surgical knots.

Lately, many suture materials have been introduced. Their physical characteristics in combination with knots are not well known. In this study, seven knots (square--1=1, 2=1, 2=1-S and 1=1=1--and sliding--SxSxS, S=S parallel S and 1-S parallel S parallel S) made in seven suture materials (plain catgut, Dexon [polyglycolic acid)] Maxon [polyglyconate], PDS [polydiaxone], Vicryl [polyglactine 910], Mersilene [polyester fiber], Prolene [polypropylene] were tested dynamically to ascertain tensile strength. The knots were classified as "predominantly breaking" (PB) and "predominantly slipping" (PS). A new method for statistical analysis, the Kaplan-Meier survival estimate, was introduced. Square knots provided good mechanical results but did not prevent slippage completely. Most sliding knots were weak. The 1=1=1 knot was superior. PS knots (1=1, 2=1, SxSxS and S=S parallel S) were unsuitable for surgical practice in monofilament or coated multifilament suture materials. The classification PB and PS knots gave an easy impression of the knot holding capacities. Application of the Kaplan-Meier estimate resulted in a more realistic analysis than classical methods.

Materials Testing↗
PubMed1989

Second-trimester placental volume measurement by ultrasound: prediction of fetal outcome.

A prospective study evaluated sonographic second-trimester placental volume measurements in the prediction of fetal outcome. A parallel section scan method was used. Abnormal fetal outcome could be predicted with a sensitivity and specificity of approximately 90%. Evidence is given that fetal growth retardation is preceded by abnormal placental development in the first half of pregnancy. To a large extent, fetal birth weight and outcome are results of placental development and the ability of the placenta to meet the growing needs of the fetus as determined by its intrinsic growth potential.

Birth Weight↗
PubMed1989

A longitudinal study of the relationship between placental and fetal growth as measured by ultrasonography.

Placental volume and fetal weight were estimated by ultrasonographic measurement at regular intervals from 16 to 20 weeks' gestation in 18 patients. The individual data were fitted to a logistic function. The estimated parameters were used to compare different groups of patients. In seven normal cases placental and fetal growth followed a sigmoid or nearly linear pattern. In four of these cases a reduction of placental and fetal growth during the last 1 to 3 weeks was apparent. In 11 cases with an abnormal outcome of pregnancy (fetal death, fetal distress necessitating a cesarean section, or neonatal weight below the 10th percentile) placental growth retardation always preceded fetal complications or growth retardation by at least 3 weeks.

Adult↗
PubMed1987

Placental volume measurement by ultrasonography: evaluation of the method.

A method for placental volume measurement by parallel ultrasonographic section scans is presented. An interval of 2 cm between the scans proves most effective. During measurement the patient should lie in the lateral position to prevent caval vein compression. The precision of the method as estimated by the SE is between 10 and 50 ml. The volume measured reflects both placental cellular mass and placental circulating blood volume. Drainage of the latter after delivery causes a fairly large difference between antepartum placental volume and postpartum placental weight (volume/weight ratio 1:6).

Female↗
PubMed1987

The effects of long-term exposure to cadmium on the small blood vessels in the rat uterus: a light microscopic study.

A group of female Wistar rats was exposed to 0.5 mg/kg cadmium three times a week for a period of 29 weeks. The cadmium was administered as the chloride in saline by subcutaneous injection. A second group of female Wistars was divided into a control group and and two experimental groups. The animals in the last two groups were exposed to 0.23 and 0.046 mg/kg cadmium three times a week for a period of 82 weeks, likewise administered by subcutaneous injection, to study the long-term effects of cadmium on the microvasculature of the uterus. The small blood vessels in the myometric layer of the uteri were studied. The thickness of the media was analyzed and an inventory was made on the morphology of the media, of the endothelial layer, and of the perivascular connective tissue. A dose- and time-related increase of the thickness of the media could be demonstrated. In the highest dose group, signs of perivascular inflammatory reaction could be observed.

Animals↗
PubMed1985

Platelet aggregation and glaucoma.

In this study platelet aggregation was determined in 79 patients with primary open angle glaucoma (POAG) and 81 patients suspected of having glaucoma (ocular hypertension). There is a positive association between high age and the presence of vascular diseases (p less than 0.01). An age dependent association between spontaneous platelet aggregation (SPA) and the presence of POAG was also observed (p less than 0.05). This indicates that the incidence of SPA in the elder group of patients with POAG is higher than in the elder glaucoma suspect group and in the group of younger patients. The association between vascular diseases and SPA and between vascular diseases and the presence of POAG were not significant at the 5% level. The incidence of SPA is not influenced by sex distribution, by the presence of diabetes, smoking or the use of timolol maleate topically.

Age Factors↗
PubMed1979

Prediction of infarct size from serial CK determinations: evaluation by clinical studies and computer simulation.

To assess reduction of infarct size by therapeutic intervention, a high predictive accuracy is mandatory. The CK release in the circulation (CKr) was studied in 12 consecutive patients after uncomplicated myocardial infarction, admitted within 5 h after onset of symptoms. Despite improvement of existing methods, such as a more frequent sampling, CK-MB determination instead of total CK determination and use of a gamma-exponential instead of a log-normal curve-fitting technique, the correlation between CKr predicted from measurements within 7 h after the start of CK rise and CKr calculated after completion of the CK curve remained poor. Computer simulations were done to investigate measurement errors as a cause of this failure. Normally distributed noise, with standard deviations ranging from 0.2% to 8.0% of peak CK-MB, was added to the first points of an ideal gamma-exponential CK-MB curve and predictions were made from these "noisy" points. A small noise already produced a great variation in prediction: 0.8% noise resulted in a deviation of predicted CKr from calculated CKr ranging from --20 to +6%. It is concluded that adequate prediction of infarct size from serial CK determinations in the first 7 h after onset of the CK rise must fail if the precision of the biochemical determination is not less than 0.4%.

Clinical Enzyme Tests↗
PubMedDate not supplied

Umbilical cord: factors which influence the separation time.

The separation time of the umbilical cord was studied in 98 healthy Indonesian newborns with the aim of determining the normal time of separation and to evaluate factors which may influence it. The authors looked for a relationship between cord separation and sex, birthweight, gestational age, parity of the mother and nutrition of the newborn. Mean separation time was 10.9 days (S.D. 3: range 5-23 days). None of the factors analysed had a statistically significant influence. Cord care consisted of triple dye; no umbilical infections were found.

Birth Weight↗
PubMedDate not supplied

Umbilical cord length and intra uterine wellbeing.

The length of the umbilical cord was studied in 179 Indonesian newborns to determine the normal range of cord length and its influence on the occurrence of intrapartum complications such as meconium stained amniotic fluid, asphyxia and entanglement of the cord around the fetus. The authors also attempted to investigate whether unfavourable intra uterine conditions could influence cord length. Therefore a correlation between cord length, sex, gestational age, birthweight and head-circumference was sought. The mean length of the umbilical cord was 52.2 cm., with a S.D. of 10.2 cm, ranging from 31-100 cm. Male infants had significantly longer umbilical cords than females (p = 0.02). The risk of complications increased parallel with cord length.

Birth Weight↗