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J T Brons

Publications and source records attributed to J T Brons.

17 recordsLinked to original sources
PubMed2004

[Pregnancy and chemotherapy; an apparent contradiction].

Two women aged 34 and 32, were diagnosed with cancer during pregnancy. The 34-year-old woman with breast cancer diagnosed during the first trimester of pregnancy, had just undergone breast-conserving surgery. She chose to have an abortion before adjuvant chemotherapy was started. A year after chemotherapy ended she became pregnant again and gave birth to a healthy child. After 3 years there were no signs of metastases. In the 32-year-old woman with a malignant lymphoma diagnosed during the third trimester of pregnancy, chemotherapy had to be started because she developed V. cava superior syndrome. The dyspnoea disappeared and a week after the first treatment she gave birth to a healthy child. A year after completion of treatment she was in complete remission and her child was developing well. Pregnancy is not always a contraindication for starting chemotherapy. However, in order to reduce the risk to mother and child as much as possible, the duration of the pregnancy as well as different groups of cytostatic drugs have to be taken into consideration. A multidisciplinary approach to mother and child is essential.

Abortion, Induced↗
PubMed1997

Ultrasonographic and radiologic visualization of the developing embryonic skeleton.

We investigated the development of the skeleton in the embryonic and early fetal period both with ultrasonography and radiology. Eight normal embryos/fetuses were studied weekly with real-time transvaginal sonography between 8 and 16 weeks of gestation to establish the ultrasonographic characteristics of normal ossification. Additionally, ossification was studied in radiographs obtained from five embryos/fetuses between 9 and 14 weeks of gestation. Ossification centers, visualized as increased echogenicity of the bone, were recognized with ultrasonography from 9 weeks onwards. The appearance of primary ossification centers as observed by transvaginal ultrasonography was at the same gestational age or at most 1 week later than when obtained with radiography or whole-specimen staining techniques. Transvaginal ultrasonography enables early visualization of ossification centers in the embryo and fetus. Detailed knowledge of the development of ossification of the skeleton may contribute to early prenatal diagnosis of skeletal dysplasias.

Bone Development↗
PubMed1995

Emergency cerclage: a review.

The treatment of patients with cervical incompetence presenting with advanced cervical changes in the second trimester remains a challenge to every obstetrician. Cerclage operation may be the only hope for prolonging gestation until fetal viability is reached. A retrospective study on so-called emergency cervical cerclage in 20 patients with supposed cervical incompetence in the late second trimester is presented, together with a review of comparable studies published between 1980 and 1992. It is concluded that emergency cerclage can be of benefit, and that the pregnancy is saved in the majority of cases, although the incidence of complications, often due to infection, is high. Many patients require prolonged hospitalization or bed rest and few pregnancies reach full term. There is a particularly high rate of infectious complications and attention must be focused on preventing chorioamnionitis to improve the outcome of the procedure in the future.

Adolescent↗
PubMed1994

Neurobehavioral effects of long-term exposure to xylene and mixed organic solvents in shipyard spray painters.

A cross-sectional study was performed in shipyard painters exposed to organic solvents and age-matched referents. The work duties of the painters mainly involved spray painting with solvent-based paints containing > 50% xylene. Testing methods consisted of a symptoms questionnaire, measurement of peripheral sensory and motor nerve parameters and computerized performance tests. Results indicate that complaints regarding mood changes, equilibrium and fatigue were more severe in painters than in referents, but were not related to the estimated life-time exposure index. Decreased nerve function was observed in the lower extremities and to some extent in the upper extremities. The refractory period appeared to be a sensitive parameter in motor nerves. Most neurophysiological parameters investigated were significantly related to the exposure index. Behavioral testing revealed impairment of simple visuo-motor performance and complex perceptual coding. A relationship between effects on perceptual coding and the exposure index was also demonstrated.

Adult↗
PubMed1993

Some variants of lethal neonatal short-limbed platyspondylic dysplasia: a radiological ultrasonographic, neuropathological and histopathological study of 22 cases.

Data on twenty-two infants with lethal neonatal short-limbed platyspondylic dysplasia are reported. Thanatophoric dysplasia (TD) is the most frequent diagnosis in this group. TD combined with a cloverleaf skull (CS), has been variably classified. TD type 1 with curved femora is rarely combined with CS; TD type 2 with straight femora is almost always associated with CS. Other varieties of TD, known as 'Torrance', 'San Diego' or 'Luton' types, are separate entities. Apart from the differences in radiography and osteochondrohistology, the temporal-lobe abnormalities seen in TD were absent in one of the cases of the 'Torrance' variety. There were also differences in the composition of the cartilage glycosaminoglycans between this case and TD. Nearly all of the cases of these different types mentioned in the literature, including those of this study group, have been sporadic and may result from new dominant mutations. Documentation and classification by full (postmortem) radiography and osteochondrohistology is essential for two reasons. It will be the foundation for the clinical geneticist to inform the parents about the risk of recurrence. It will also be the basis for a biochemical or molecular-biological classification in the near future.

Brain↗
PubMed1990

Prenatal ultrasonographic diagnosis of radial-ray reduction malformations.

Radial-ray reduction malformations (RRRMs) may occur isolated or in association with other anomalies. The data of seven fetuses born with RRRMs were collected. Six fetuses had associated lethal abnormalities of the central nervous system, urogenital system, and/or heart, detected by ultrasound. In five cases, it was possible to establish the precise diagnosis, enabling an informed prognosis and subsequent genetic counselling. The diagnoses were: Edwards syndrome (n = 3), VACTERL association (n = 1), and Poland-Moebius-like complex (n = 1). In two cases, a complete diagnosis was not possible because of inadequate evaluation of these fetuses before and/or after birth. A proposal is given for the diagnostic approach for infants with RRRMs detected in the antenatal period by means of ultrasonography.

Abnormalities, Multiple↗
PubMed1990

The prenatal development of the normal human skeleton: a combined ultrasonographic and post-mortem radiographic study.

Post-mortem radiography of fetuses with skeletal dysplasia is essential for diagnostic classification. Interpretation of the radiographs should be based on the knowledge of morphology and dimensions of the normal skeleton in all stages of development. A retrospective post-mortem radiographic study is presented with measurements of the lengths of the long bones and thoracic and lumbar spine. The study included 69 fetuses and neonates with a normal skeleton, whose gestational age ranged from 13-42 weeks and who died perinatally or lived for less than one week. The measurements of the long bones were plotted on growth curves obtained from a prospective longitudinal ultrasonographic investigation of another group of 63 normal fetuses from 12-40 weeks of gestation. Thoracic and lumbar spine measurements by ultrasonography were not available. The radiographic data of thoracic and lumbar spine were, therefore, compared to radiographic studies from the literature. No disagreement with these studies was found. It can be concluded that measurements of bones from standardized post-mortem radiographs in cases of questionable gestational age or defects of bone development can be compared with ultrasonographic measurements. To illustrate the usefulness of the graphs, 13 fetuses with various types of skeletal dysplasia were evaluated retrospectively.

Bone Diseases, Developmental↗
PubMed1990

Prenatal diagnosis of fetal tumors by ultrasonography.

Fetal tumors lead to serious illness or even death in the fetal or neonatal period. Problems vary from severe hydrops to underdevelopment of fetal organs. In some instances a tumor may cause mechanical obstruction during the birth process. Polyhydramnios frequently develops. Adequate prenatal diagnosis is of utmost importance. Timely detection of the fetal tumor prevents traumatic birth and postnatal care and treatment can be scheduled. This report is a review of the relevant recent literature and the tumors detected in our ultrasound unit between 1982 and 1988. The ultrasonographic appearance, clinical course, and differential diagnosis of the tumors are discussed.

Female↗
PubMed1988

Prenatal ultrasound diagnosis of the Holt-Oram syndrome.

The Holt-Oram syndrome is an autosomal dominant disorder consisting of a congenital heart defect in combination with characteristic upper limb abnormalities. This report presents the ultrasonographic follow-up of two fetuses at risk for the Holt-Oram syndrome. In the first fetus, the existence of Holt-Oram syndrome was suspected at 22 weeks of gestation; a ventricular septal defect, an atrial septal defect, and a minor skeletal defect were found. In the second fetus, no structural abnormalities were discovered until the 30th week, when a small atrial septal defect was detected. In both pregnancies, it was possible to exclude early in gestation the more severe forms of the Holt-Oram syndrome.

Bone and Bones↗
PubMed1988

Prenatal ultrasonographic diagnosis of osteogenesis imperfecta.

Between 1982 and 1986, osteogenesis imperfecta was diagnosed by ultrasound in seven fetuses. The known heterogeneity of osteogenesis imperfecta was confirmed by the prenatal ultrasonographic findings. Dependent on the type of osteogenesis imperfecta, the appearance of the limbs varied from severely shortened and broad, with very low echogeneity and absent acoustic shadow (type IIA), to only moderately shortened and thin, with almost normal echogeneity and acoustic shadow but clearly visible fractures causing angulation of the bone (types IIC and III). Ultrasonography offers the possibility to detect or exclude the lethal and severe forms of osteogenesis imperfecta early (type IIA) or halfway (types IIB, IIC, and III) through the second trimester. Prenatal diagnosis of the disease allows the option of elective abortion or may prevent unnecessary obstetric intervention.

Adult↗
PubMed1988

Fetal heart rhythms during behavioural state 1F.

Behavioural state 1F (quiet sleep) of the term fetus is defined on the basis of absence of eye and body movements, and the presence of a specific heart rate pattern (FHRP A), characterized by a stable heart rate with a small oscillation bandwidth. In the present paper the fetal heart rate pattern was studied in 39 enclosed periods with absence of fetal eye and body movements. In 37 periods the heart rate pattern met the criteria of FHRP A. Within FHRP A various distinct types of heart rhythm could be distinguished related to presence of breathing or regular mouthing and complete absence of movements. The bandwidth in the various heart rhythms differed significantly and was largest during breathing movements. During regular mouthing an oscillatory pattern was present with a frequency similar to the frequency of the clusters of mouthing movements. In 2 periods the heart rate deviated from the definition for FHRP A, i.e. a sinusoidal-like rhythm associated with sucking movements. These observations demonstrate the strong association between the fetal heart rate pattern and fetal movements during behavioural state 1F.

Electrocardiography↗
PubMed1988

Achondrogenesis-hypochondrogenesis: the spectrum of chondrogenesis imperfecta. A radiological, ultrasonographic, and histopathologic study of 23 cases.

In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis have recently received special attention. We describe 23 cases representing the different subtypes. Within the classical type I (Parenti-Fraccaro) two distinct disorders can be recognized: type IA (Houston-Harris) and type IB (Fraccaro). The classical type II (Langer-Saldino) and hypochondrogenesis represent phenotypic variants of one disorder in which type II is the most severe form and hypochondrogenesis the mildest form, while transitional forms exist. It is likely that a basic defect in cellular function of the chondrocyte results in a deficient cartilage matrix and in disorganized enchondral ossification.

Bone Matrix↗
PubMed1988

Perinatal lethal osteogenesis imperfecta: radiologic and pathologic evaluation of seven prenatally diagnosed cases.

The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), diagnosed prenatally by ultrasound in the 15th to 34th week, are described. They include four variants of the Sillence classification: types IIA, IIB, IIC, and type III. The radiologic criteria that differentiate these types of OI are described. The histopathology of the bones differed only slightly in types IIA, IIB, and III; OI type IIC, however, differed markedly from the other types.

Female↗
PubMed1986

Fetal behavioural states in epileptic pregnancies.

Possible negative effects of maternal antiepileptic medication on fetal motility and heart rate patterns were examined at 32 and 38 wk of gestation. Fetal eye and body movements were recorded using 2 real-time ultrasound units. Comparison between pregnancies with antiepileptic medication and control pregnancies did not show marked differences in patterns of motility and heart rate. Duration of sleep states, occurrence and duration of body movements in state 2F and statistical parameters of heart rate level and heart rate variability were very similar for both groups. This preliminary study, limited to mostly combined treatment with antiepileptic drugs, could not demonstrate any obvious effect on fetal neuromuscular development from maternal antiepileptic medication.

Adult↗
PubMedDate not supplied

The fetal skeleton; ultrasonographic evaluation of the normal growth.

A longitudinal study of normal fetal growth is presented as a basis for prenatal diagnosis of skeletal dysplasias. The lengths of fetal limb bones, abdominal circumference, thoracic circumference, head circumference, foot length and orbital diameters were measured in 63 normal fetuses between 12 and 40 weeks of gestation. From these data, ratios were calculated which may have relevance for the prenatal diagnosis of skeletal dysplasias. In addition, rates were calculated for fetal limb growth. From these parameters (absolute measurements, ratios and growth rates), the 10th, 50th and 90th centiles were determined as reference values.

Bone Development↗
PubMedDate not supplied

Ratios between growth parameters for the prenatal ultrasonographic diagnosis of skeletal dysplasias.

The clinical applicability and usefulness of nine ratios that express the relation between particular fetal growth parameters were tested in ten fetuses affected by skeletal dysplasia. The results were compared with the ratios calculated from five growth-retarded fetuses without structural anomalies. Femur/foot, femur/head circumference, head circumference/thoracic circumference and abdominal circumference/thoracic circumference ratios are useful additional parameters for the prenatal ultrasonographic diagnosis of skeletal dysplasias. They reduce the problem of an unknown gestational age and help to distinguish between fetal skeletal dysplasia and intra-uterine growth-retardation caused by other factors.

Bone Development↗