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Biomedical subjects

J de Haan

Publications and source records attributed to J de Haan.

At least 91 records · Page 5Linked to original sources
PubMed1985

Follicle growth curves and hormonal patterns in patients with the luteinized unruptured follicle syndrome.

A prospective longitudinal and standardized study is presented, dealing with ultrasonographic and hormonal characteristics of the luteinized unruptured follicle (LUF) syndrome. Among 600 cycles monitored in 270 infertility patients, 40 cycles in 27 patients showed no evidence of follicle rupture, in spite of signs of luteinization, as reflected by basal body temperature recordings and progesterone determinations. In this study, 20 LUF cycles in 20 infertile patients were compared with 45 ovulatory cycles in 45 control women. During the follicular phase, no substantial difference in follicle growth was found, but after the luteinizing hormone peak, LUF follicles, instead of rupturing, showed a typical accelerated growth pattern. Both mean luteinizing hormone peak levels and midluteal progesterone levels were significantly lower in LUF cycles than in the control cycles. However, the duration of the luteal phase was not affected. Both central and local factors can be held responsible for the lack of follicle rupture. Ultrasound offers new possibilities as a noninvasive method in diagnosing the LUF syndrome.

Adult↗
PubMed1985

Magnetic resonance imaging of the normal female pelvis.

9 healthy volunteers were examined by magnetic resonance imaging in order to describe the anatomy of the normal female genital tract as seen by this technique. The visualization of the bony and pelvic skeleton and the muscles surrounding these structures is excellent. Due to high contrast resolution relatively small structures like the femoral blood vessels can be positively identified. Imaging of the small bowel is disappointing. Visualization of the rectum and sigmoid colon is relatively good. In the uterine wall three distinct layers can be identified. An interpretation of the origin of these layers based on comparison with macroscopic and microscopic examination of sections of uterine tissue is given. Further research is needed to demonstrate possible cyclic changes in the appearance of the uterus. The ovaries could not be identified with certainty.

Adult↗
PubMed1984

Serum levels of ritodrine during oral maintenance therapy.

In order to elucidate some aspects of the efficacy of orally administered ritodrine, serum concentrations of ritodrine were determined during intravenous and oral therapy. Ritodrine serum concentrations during steady-state intravenous therapy (200 micrograms/min) ranged from 91.0 to 123.0 ng/ml. Serum concentrations during maintenance therapy with 120 mg ritodrine per os fluctuate between 3.2 and 30.5 ng/ml, depending on the moment of tablet intake. During oral maintenance therapy a striking correlation was found between the maternal heart rate and the serum concentration of ritodrine. The findings suggest that efficacy of orally administered ritodrine is doubtful on pharmacological grounds.

Administration, Oral↗
PubMed1984

Predictive value of uterine contractility and the serum levels of progesterone and oestrogens with regard to preterm labour.

A longitudinal investigation regarding the serum concentrations of oestradiol, oestriol and progesterone in relation to uterine activity has been performed in 80 healthy primigravid women during the course of pregnancy up to the 37th week of pregnancy. The frequency of uterine contractions was quantitatively objectivated by means of external toco-dynamometry; simultaneously the uterine activity has been recorded by the pregnant women qualitatively. It appears that there is a gradual increase of all the three mentioned hormones during the course of pregnancy. However, there is a large interindividual spread. There exists no relation between the hormonal serum levels and uterine activity (quantitatively as well as qualitatively recorded). Between these two latter there is a poor relation. It is impossible to predict the occurrence of preterm birth based on hormonal serum changes. This holds for the progesterone-oestradiol ratio.

Adult↗
PubMed1984

Computed tomography in staging untreated patients with cervical cancer.

In a study to test the accuracy of computed tomography (CT) in staging untreated patients with cervical cancer, the interpretations of the CT scans of pelvis and abdomen of 56 consecutive patients were compared with surgical and/or clinical findings. This study clearly demonstrates that CT is unreliable in diagnosing parametrial tumour invasion and that it is not justified to make the therapeutically important differentiation between a IB or IIB stage with CT. In demonstrating metastatic lymph nodes, the accuracy of CT was only 75%, predominantly due to metastatic deposits in normal-sized nodes. CT was less accurate in diagnosing bladder wall and sigmoid invasion than cystoscopy and sigmoidoscopy, respectively, and was as accurate as urography in diagnosing ureteric obstruction. For these reasons, CT is not indicated as a routine procedure in cervical cancer staging, particularly not in the early stages of the disease. CT may be helpful in the higher clinical stages to measure tumour bulk and to get an impression about the whole extent of the disease.

Female↗
PubMed1983

Amniotic fluid amylase concentration: a reliable predictor of fetal maturity?

The amylase concentration in the amniotic fluid (ACAF) was studied in 138 subjects in relation to duration of pregnancy, fetal weight, L/S ratios and neonatal occurrence of respiratory distress syndrome (RDS). ACAF was found to be significantly correlated with duration of pregnancy (p less than 0.001) and fetal weight (p less than 0.005). The number of false immature predictions, based on a critical value of ACAF of 200 U/l, was relatively high: 36% for the gestational age greater than or equal to 36 weeks, and 38% for fetal weight greater than 2,500 g. ACAF also showed a significant relationship with the L/S ratio (p less than 0.0001). ACAF less than 300 U/l correctly predicted all instances of L/S ratio less than 2.0; however, the rate of false low predictions was 60%. In only 22 out of 138 AF samples (16%) could the performance of an L/S ratio have been avoided on the basis of the ACAF. ACAF less than 300 U/l correctly predicted both cases of neonatal RDS in the study population; however, 1 of these fetuses had an ACAF of 260 U/l. There were four times as many false predictions of lung immaturity on the basis of ACAF less than 300 U/l as from the L/S less than 2.0.

Amniotic Fluid↗
PubMed1982

Basal body temperature as a method of ovulation detection: comparison with ultrasonographical findings.

In 47 cycles with hormonal evidence of ovulation, the detection and timing of ovulation by basal body temperature (BBT) and by ultrasonographical observation are compared. The ovulation detection rate by ultrasonographical method proves to be considerably higher than by BBT criteria. The timing of the day of ovulation is evaluated, assuming that the ultrasonographical event of follicle disappearance represents ovulation. BBT criteria nadir, coverline and the eye-balling method show a very poor frequency distribution. The result of the FDHP method is a nearly symmetrical distribution, however, with a considerable range. We conclude that ovulation detection and timing by BBT are not reliable.

Body Temperature↗
PubMed1980

Placental size during early pregnancy and fetal outcome: a preliminary report of a sequential ultrasonographic study.

Placental growth during pregnancy was studied serially by ultrasonographic measurement of placental area in 50 primigravid women. Placental area at a menstrual age of 150 days was compared to infant birth weight. Small placental area at a menstrual age of 150 days was significantly related to low infant birth weight (< tenth percentile of birth weight for gestational age). A "warning limit" of placental area at midpregnancy was calculated. If placental area was equal to or smaller than this limit of 187 sq cm, six of nine patients (67%) compared to four of 41 subjects with larger placentas (p < 0.01) were delivered of a small-for-gestational age baby. Ultrasonographic placental area measurement in midpregnancy thus appears to be of prognostic value in identifying pregnancies at high risk for the subsequent occurrence of fetal growth.

Female↗
PubMed1980

Analysis of heart rate and beat-to-beat variability: Interval difference index.

The relationshp between the RR interval length (RR) and the RR interval-to-interval differences (RR differences) was investigated. Data on heart rate were obtained from 11 newborn infants in well-defined behavioral states undergoing polygraphy. It was found that the RR differences were strongly dependent on the RR interval length in all behavioral states. The relationship between the RR differences (y) and the interval length (RR) could be described by the equation y = alpha (RR-320)1.5 for the interval length in the investigated range from 375 to 605 msec. On the basis of this relationship the interval difference index (ID index) was constructed for the quantification of beat-to-beat heart rate variability. The ID index showed good independence from the long-term irregularity index (LTI index). Other statistical parameters proposed for the quantification of beat-to-beat heart rate variability are discussed and compared with the ID index.

Electrocardiography↗
PubMed1980

Heart rate as an indicator of the behavioral state. Studies in the newborn infant and prospects for fetal heart rate monitoring.

Term healthy newborn infants underwent polygraphy between days 4 and 6 of life. Behavioral states were determined according to Prechtl's criteria. The neonatal heart rate was analyzed for the various behavioral states, with the use of quantitative indices for long-term and short-term irregularity. The applied indices were, respectively, the long-term irregularity index (LTI index) and the interval difference index (ID index). During state 1 the R-R interval length was longer (p less than 0.01), the LTI index lower (p less than 0.01), and the ID index higher (p less then 0.02) than in the immediately preceding or following state 2. For nonconsecutive states 1 and 2 a maximum separation was obtained with the discriminant function 0.0159 RR - 0.065 LTI + 0.062 ID - 7.49. This discriminant function gave a total percentage of correct classification of states 1 and 2 epochs of 93%. The data are discussed with respect to the presence of cycling sleep states in the newborn infant as well as in the fetus. Prospects for fetal antepartum heart rate monitoring are considered.

Behavior↗
PubMed1980

Ultrasonographic placental localization with respect to fetal position in utero.

Ultrasonographic localization of the placental site was performed serially throughout pregnancy in 56 primigravidas with anteriorly located placentas. The placenta was found to be located on the right side of the uterus significantly more frequently than at any other site on the anterior uterine wall. Placental position was found to be related to the position of the fetus in utero. The role of placental location in determining the high incidence of the left occiput position at delivery is discussed.

Female↗
PubMed1980

The effect of diazepam administration during pregnancy or labor on the heart rate variability of the newborn infant.

Maternal diazepam medication during labor reduces beat-to-beat variability of the fetal heart rate. In this study, the prolongation of the effect was examined in the newborn. The mother received diazepam: (A) during labor as a tranquilizer, (B) daily in low doses at the end of pregnancy, or (C) in high doses i.v. for (pre-)eclampsia. A control group had no analgesic or sedative during pregnancy or labor. The electrocardiogram (ECG) was recorded daily from each newborn during the first 6 days after birth. After preprocessing of the ECG, the median R-R interval, the long-term irregularity index (LTI index) and the interval difference index (ID index) were calculated. A cubic spline interpolation method was applied to compare the various groups with respect to these heart rate parameters. The median R-R interval showed no particular differences in trend for all groups. The LTI index was decreased in the first days after birth in the chronic diazepam (B), and in the diazepam infusion groups (C), but statistical significance was not reached. The ID index was significantly decreased in the first 1-2 days in the newborns of the acute and chronic diazepam group. In the diazepam infusion group, an even longer lasting effect was observed. Maternal diazepam medication affects the beat-to-beat variability in the newborn. The duration of the effect is dependent on dosage and route of administration.

Diazepam↗
PubMed1979

Isolation of lysosomes from brain tissue. A separation method by means of alteration of mitochondrial and synaptosomal sedimentation properties.

1. A crude mitochondrial-lysosomal preparation from brain tissue was layered on a sucrose gradient containing 20mm-succinate, 10mm-Tris and 1mm-disodium EDTA at pH7.4. The lysosomes were separated from the mitochondria and synaptosomes by means of a twosteps centrifugation procedure. In a first low-speed step (40min at 5300g at 15 degrees C) the sedimentation rate of mitochondria and mitochondria-containing synaptosomes was enlarged due to passage of these subcellular structures through the sucrose gradient with the above-mentioned chemicals (called ;chemical field'). That part of the gradient which contained the mitochondria and synaptosomes was removed and substituted by a gradient suitable for isopycnic isolation of lysosomes in a second centrifugation step. The achieved purification for bovine brain lysosomes was 5-8-fold, for rat brain lysosomes 7-10-fold, over the homogenate. 2. The enlargement of the sedimentation rate of mitochondria and synaptosomes was brought about by the presence of succinate, but also by one of the following salts in the chemical field: malonate, fumarate, pyruvate, phosphate and chloride. 3. Comparison of the chemical-field method with other methods for the isolation of lysosomes showed that (a) with the chemical-field method a 2-3-times higher purification of the rat and bovine brain lysosomal fraction can be achieved than with the procedure described by Koenig, Gaines, McDonald, Gray & Scott [(1964) J. Neurochem.11, 729-743], and that (b) similar purification results for rat liver lysosomes were obtained when the chemical-field method and the procedure described by van Dijk, Roholl, Reijngoud & Tager [(1976) FEBS Lett.62, 177-181] were compared.

Animals↗
PubMed1979

Mechanisms of late decelerations in the fetal heart rate. A study with autonomic blocking agents in fetal lambs.

Fetal heart rate decelerations resembling the late deceleration FHR pattern were produced in fetal sheep by periodic occlusion of the maternal common hypogastric artery for 30-60 sec. Transient fetal hypertension also occurred during the occlusions. Alpha-adrenergic blockade with phentolamine eliminated or markedly reduced the hypertensive response. FHR decelerations still occurred intermittently with some occlusions; however, their character was greatly altered. After parasympathetic blockade with atropine, the decelerations were replaced by periodic FHR accelerations during the occlusions. These accelerations were, in turn, eliminated by the beta-adrenergic blocking agent, propranolol. In the presence of combined parasympathetic, alpha- and beta-adrenergic blockade, the FHR remained essentially constant during the hypogastric artery occlusions in non-acidemic fetuses. FHR decelerations persisted after parasympathetic or total autonomic blockade when the fetuses were significantly hypoxic, as judged by depressed arterial blood pH and base excess values. Beat-to-beat variability of the baseline FHR persisted in the face of severe hypoxia and acidosis. These observations demonstrate that reflex mechanisms are involved importantly in the genesis of late deceleration FHR patterns in the acutely hypoxemic fetus, but that direct depression of myocardial rhythmicity becomes a factor as hypoxic acidosis develops.

Acetylcholine↗