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Biomedical subjects

N F Arts

Publications and source records attributed to N F Arts.

30 records · Page 2Linked to original sources
PubMed1985

Twin pregnancy: case reports illustrating variations in transfusion syndrome.

The twin transfusion syndrome is diagnosed in 5.5% to 14.6% of monochorionic twins and the classical picture reveals a small anemic donor and a large plethoric recipient. Many other clinical discrepancies have been described. Today, by ultrasound it is possible to diagnose the syndrome in (early) pregnancy. In these case reports different clinical pictures and the importance of ultrasound are described. In twin pregnancies repeated ultrasound examinations should be considered with the consequences of vascular anastomoses.

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↗
PubMedDate not supplied

Fluid transport across human fetal membranes affected by human amniotic fluid prolactin: an in vitro study.

The aim of the study was to investigate the effects of human amniotic fluid (AF) prolactin (PRL) on the transfer of fluids across human fetal membranes, detected in vitro by weight change. We have developed a system, consisting of an inner compartment (4 ml), suspended in an outer compartment (40 ml), and separated from it by a 2 cm2 circular piece of fresh human fetal membrane (amnion, chorion and adhering decidua). The weight of the inner compartment was continuously registered with an electronic precision balance. Osmolality changes or hydrostatic pressure differences did not affect the rate of mass transfer through the membranes. Potassium cyanide significantly influenced the mass transfer in favour of the applied hydrostatic pressure difference (+2 cm H2O to the amniotic side) or osmotic pressure difference (amniotic side 265 mosm/kg/decidual side 285 mosm/kg). The PRL preparations used were human and ovine pituitary PRL, as well as three fractions isolated from human AF by fractionated ammonium sulphate and ethanol precipitations, followed by Sephacryl chromatography. All PRL preparations were tested in physiologic concentrations (0.5 to 5 micrograms/ml). Only the two largest AF-PRL variants significantly disturbed the balance of fluid transfer across the membranes when added to the fetal (amniotic) side of the membrane. This resulted in a net increase in fetomaternal transfer of 120 to 180 microliters. This effect could be repeated and lasted for at least 25 minutes. Using an antibody against hPRL the effect was completely blocked. Neither AF-PRL added to the maternal (decidual) side of the membrane nor oPRL or human pituitary PRL added to the amniotic or decidual side changed the rate of mass transfer across the membranes.

Amniotic Fluid↗
PubMedDate not supplied

In vitro secretion of peptide hormones by the human placenta: I. ACTH.

In order to address the question of autonomy of placental hormone secretion, fresh human term placentae were utilized for the preparation of small tissue fragments. The fragment pool was divided over four parallel chambers in a superfusion apparatus and could thus serve as both control and experiment under identical in vitro conditions. Oxygen consumption was substantial and could be maintained for at least 5 h. Adrenocorticotrophic hormone (ACTH) concentrations in the effluent buffer were estimated by radioimmunoassay and bioassay. Both non-specific (membrane depolarization with 45 mM KCl) and specific (isoproterenol at 10(-7) M) stimulation increased the ACTH secretion from 10 to 20 pg/min/g to 60 to 80 pg/min/g. Propranolol blocked the adrenergic stimulation almost completely, indicating the specificity of the effect. Thus, in terms of in vitro ACTH secretion, the human placenta can be stimulated and therefore does not seem to behave in an autonomous manner.

Adrenocorticotropic Hormone↗