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Biomedical subjects

S Campbell

Publications and source records attributed to S Campbell.

At least 325 records · Page 18Linked to original sources
PubMed1996

Transvaginal three-dimensional ultrasound: accuracy of follicular volume measurements.

OBJECTIVES: To evaluate the accuracy of three-dimensional (3-D) ultrasound (US) follicular volume measurements. DESIGN: Prospective clinical study. SETTING: A tertiary referral center for assisted reproduction. PATIENTS: Twenty-five patients undergoing ovarian stimulation for IVF-ET using the long protocol of GnRH agonist. INTERVENTION: Transvaginal two-dimensional (2-D) and 3-D ovarian scan performed immediately before US-directed follicle aspiration. MAIN OUTCOME MEASURES: The volume of follicular fluid aspirated was compared with the corresponding volume of the follicle measured by 3-D US and with the conventional 2-D US volume measurement calculated using the formula pi/6 (D1 x D2 x D3). Limits of agreement and 95% confidence intervals were calculated and systematic bias between the methods was analyzed. RESULTS: The limits of agreement between the volume of follicular aspirate and follicular volume determined by US were +0.96 to -0.43 mL for 3-D measurements and +3.47 to -2.42 mL for 2-D measurements. CONCLUSIONS: The true volume of ovarian follicles, within the clinically useful range for IVF-ET cycles, is measured more accurately by a 3-D US system than by 2-D US techniques.

Female↗
PubMed1996

Selection and identification of standard cardiac views from three-dimensional volume scans of the fetal thorax.

The feasibility of fetal echocardiographic examination using three-dimensional ultrasonography was investigated in 54 healthy pregnant women with uncomplicated pregnancies between 17 and 37 weeks of gestation. In 46 cases (85.2%), good quality three-dimensional volumes of the fetal heart were obtained from both apical and lateral four-chamber views. By reslicing apical volumes, the reformatted sections of the long axis view of the left ventricle and the aortic crest were seen in 40 (87%) and 38 (83%) of 46 cases, respectively. The short axis was seen in 26 (57%) and ductal arch in 30 (65%) cases. The examination of lateral volumes was much less successful. The short axis was seen in 11 (24%) cases, and the aortic crest in 22 (48%), whereas the analysis of the longitudinal views was not possible. The best results were obtained at a gestational age between 22 and 27 weeks. Three-dimensional fetal echocardiography allowed the examination of the four chambers of the heart and left outflow tract during the late second trimester. The technique may become useful for the screening and diagnosis of congenital cardiac defects in the future.

Aorta↗
PubMed1996

Paediatric community nursing: doctors' views.

Children should always be cared for at home if possible. Plans to expand the paediatric community nursing service need to take the views of doctors into account. Liaison between the service, referring doctors and the hospital services is essential.

Attitude of Health Personnel↗
PubMed1996

Effects of indomethacin on follicular structure, vascularity, and function over the periovulatory period in women.

OBJECTIVE: To assess the effect of indomethacin (taken at defined times) on follicular rupture, indexes of intrafollicular blood flow, and steroidogenesis. PARTICIPANTS: Six healthy volunteers awaiting treatment for infertility by IVF-ET during subsequent natural cycles. INTERVENTIONS: All women were examined (at least every 8 hours) by transvaginal ultrasonography with color Doppler imaging and had samples of blood taken for hormone analysis. A self-test for urinary LH was performed before each scan. Indomethacin was first taken (50 mg three times per day) according to the maximum follicular diameter (first four women) or when the LH dipstick gave a positive result; the drug was taken for > or = 3 days. RESULTS: Follicular rupture was delayed in five of six cases (by 2 to 12 days). There was a reduction in intrafollicular peak systolic velocity before and after the positive urinary LH test compared with historical controls. Three follicles (50% of women) with the highest peak systolic velocity had an hemorrhagic appearance and persisted longer. There was no significant effect on menstrual cycle length or the levels of circulating FSH, E2, LH, or P. CONCLUSION: Indomethacin administered at the time of a positive self-test for urinary LH can delay follicular rupture with an associated reduction in intrafollicular blood flow but with no apparent effects on hormonal or menstrual status.

Adult↗
PubMed1995

Assessment of fetal compromise by Doppler ultrasound investigation of the fetal circulation. Arterial, intracardiac, and venous blood flow velocity studies.

BACKGROUND: Doppler studies of the fetal circulation in intrauterine growth retardation and hypoxia have demonstrated a compensatory redistribution of arterial blood flow with increased flow to the cerebrum and myocardium and decreased flow to the periphery. The aim of this study was to evaluate the significance of changes in fetal venous blood flow waveforms in high-risk pregnancies and to investigate the time relation between alterations in venous and arterial Doppler waveform indices in compromised fetuses. METHODS AND RESULTS: The cross-sectional study consisted of 108 high-risk singleton pregnancies between 23 and 42 weeks' gestation without fetal chromosomal abnormalities or major malformations. Blood flow velocity waveforms were recorded from the umbilical arteries, descending thoracic aorta, middle cerebral artery, tricuspid and mitral ventricular inflow, ductus venosus, inferior vena cava, and the right hepatic vein. The mean velocity and pulsatility index were calculated for arterial vessels, the E/A ratio for atrioventricular blood flow, and peak forward velocities during ventricular systole and early diastole, the lowest forward velocity or peak reverse velocity during arterial contraction, and time-averaged maximum velocity for venous vessels. Two ratios for venous waveforms, one of which is the equivalent of the pulsatility index, were calculated. Fetal biophysical assessment was based on a computerized cardiotocogram and the biophysical profile score. The compromised group consisted of 37 fetuses delivered by cesarean section for an abnormal heart rate trace (n = 21) or severe preeclampsia (n = 9) or which died in utero (n = 7) within 10 days of their last Doppler investigation. This group showed significant alterations in arterial and venous flow velocity waveforms but not in atrioventricular inflow. Additionally, to find out whether venous Doppler investigation may help to detect a worsening of the situation in fetuses already showing arterial blood flow redistribution, we analyzed the data of these fetuses separately. The 41 fetuses that had an aorta/middle cerebral artery pulsatility index ratio > 95th percentile were divided into compromised and non-compromised groups according to their biophysical assessment and whether or not they developed fetal distress (cesarean section for abnormal heart rate trace or intrauterine death). The mean values for Doppler parameters of the compromised groups differed significantly from the noncompromised groups in all venous vessels, whereas differences on the arterial side were much less pronounced. Velocity ratios of venous waveforms were significantly higher, and absent or reverse flow in the ductus venosus with atrial contraction indicated a poor prognosis, with a perinatal mortality of 5 out of 8. CONCLUSIONS: Fetal compromise is associated with significant alterations in the fetal arterial and venous circulation. Significant changes in venous Doppler waveforms develop due to increased afterload and perhaps myocardial failure in late deterioration after fetal arterial redistribution is established and seem to be closely related to abnormal biophysical assessment findings. Therefore, Doppler investigation of the fetal venous circulation may play an important role in monitoring the redistributing growth retarded fetus and thereby may help to determine the optimal time for delivery.

Arteries↗
PubMed1995

Fetal venous, intracardiac, and arterial blood flow measurements in intrauterine growth retardation: relationship with fetal blood gases.

OBJECTIVE: Our purpose was to investigate arterial, venous, and intracardiac blood flow in growth-retarded fetuses and to relate the Doppler results to blood gases in umbilical venous blood obtained by cordocentesis. STUDY DESIGN: A cross-sectional, pulsed-wave color Doppler ultrasonographic study of 23 severely growth-retarded fetuses undergoing cordocentesis and measurement of blood gases was performed. Blood velocity waveforms were recorded from the descending thoracic aorta, middle cerebral artery, inferior vena cava, ductus venosus, and atrioventricular valves. RESULTS: The Doppler studies demonstrated evidence of redistribution in the arterial system with increased impedance to flow in the aorta and decreased impedance in the cerebral circulation. The velocity of flow in the venous system and across the atrioventricular valves was decreased, whereas pulsatility of waveforms in the inferior vena cava and ductus venosus was increased. The mean umbilical venous blood PO2 and pH were decreased, and there were significant associations between blood gases and Doppler parameters in the thoracic aorta, middle cerebral artery, and ductus venosus. CONCLUSION: In severe intrauterine growth retardation the degree of fetal acidemia can be estimated from Doppler measurements of pulsatility in both the arterial system and the ductus venosus.

Aorta, Thoracic↗
PubMed1995

Effect of serum on secretion of prostacyclin and endothelin-1 by decidual endothelial cells from normal and preeclamptic pregnancies.

OBJECTIVE: Increasing circumstantial evidence suggests that the maternal endothelial cell is centrally involved in the syndrome of preeclampsia, and a number of reports have described the presence of a factor(s) that alters endothelial cell function in serum from women with preeclampsia. We have previously described differences between endothelial cells from the decidual vascular bed and those from the umbilical vein. The purposes of this study were (1) to examine the effect of serum from normal and preeclamptic women on secretion of vasoactive substances by maternal decidual endothelial cells, (2) to compare these results with those from umbilical vein endothelial cells, widely used as a surrogate for endothelial cells in general, (3) to compare responses to these sera by decidual endothelial cells from normal and preeclamptic pregnancies, and (4) to determine whether these responses are amplified by preincubation in test sera. STUDY DESIGN: Endothelial cells were isolated from umbilical veins and from decidual biopsy specimens collected at caesarean section delivery, from both normal and preeclamptic women. Cells were maintained in culture until passage 2, when secretion by the three endothelial cell populations of the vasodilator prostacyclin (measured as its stable metabolite, 6-keto-prostaglandin F1 alpha) and the vasoconstrictor endothelin-1 was compared in the presence of serum from preeclamptic or gestational age-matched normal pregnant women. RESULTS: Prostacyclin secretion by all endothelial cell populations was higher in the presence of serum from preeclamptic women than in medium containing serum from gestational age-matched normal pregnant women. Values for endothelin were not significantly different in cells incubated in serum from normal or preeclamptic women. Preincubation of decidual cells from preeclamptic women in test serum, particularly in preeclamptic serum, resulted in more marked stimulation of prostacyclin secretion. CONCLUSIONS: Preeclamptic serum contains a factor(s) that stimulates prostanoid secretion from endothelial cells. This effect was observed in both umbilical vein and decidual cells. Cells from preeclamptic women were more susceptible to perturbation of their secretion by this factor. Serum from preeclamptic women did not specifically affect endothelin-1 secretion.

6-Ketoprostaglandin F1 alpha↗