Search PubMed⌕ Search

Biomedical subjects

A Connelly

Publications and source records attributed to A Connelly.

82 records · Page 5Linked to original sources
PubMed1988

Low-dose aspirin therapy improves fetal weight in umbilical placental insufficiency.

A randomized, placebo-controlled, double-blind trial was carried out to evaluate the fetal benefits of low-dose aspirin (150 mg/day) as a treatment of placental insufficiency during the last trimester of pregnancy. Forty-six women referred for study because there was concern about fetal welfare were found to have an elevated umbilical artery wave form systolic/diastolic ratio. Mothers with severe hypertension were excluded because fetal condition would not necessarily be the dominant determinant of obstetric decision making. A distinction was made between a high systolic/diastolic ratio (greater than 95th but less than 99.95th percentile) and an extreme systolic/diastolic ratio (greater than 99.95th percentile). There were 34 patients in the high ratio group and 12 in the extreme group. Aspirin therapy was associated with an increase in birth weight (mean difference 526 gm [p less than 0.02]), head circumference (1.7 cm [p less than 0.025]), and placental weight (136 gm [p less than 0.02]) in those patients with a high initial umbilical artery systolic/diastolic ratio. For the 12 women with an extreme initial systolic/diastolic ratio, aspirin therapy did not result in a significantly different pregnancy outcome.

Adult↗
PubMed1988

Umbilical artery flow velocity waveforms and twin pregnancy outcome.

Two hundred seventy-two twin pregnancies were studied by analysis of the fetal umbilical artery waveforms recorded using continuous-wave Doppler ultrasound. After the first 100 cases, a management strategy was adopted whereby all twin gestations would be studied between 28-32 weeks' gestation and the results made available to the referring obstetrician, thereby influencing clinical management. Perinatal mortality and morbidity, in pregnancies with both fetuses alive at 28 weeks' gestation, were compared between the patients studied in the first group of 100 and those studied after the Doppler examination was introduced as a clinical service. There was a decrease in perinatal mortality, both uncorrected (57.9 per 1000 to 17.9 per 1000; P less than .05) and corrected (42.1 per 1000 to 8.9 per 1000). Fetal deaths were reduced from six to one (P less than .05). This decrease in perinatal mortality was achieved without any appreciable change in the gestational age at delivery or mode of delivery between the two groups. There was a reduction in the number of infants requiring neonatal intensive care (from 38% to 24%; P less than .01).

Birth Weight↗
PubMed1988

Monitoring lupus anticoagulant-positive pregnancies with umbilical artery flow velocity waveforms.

The presence of the "lupus anticoagulant" in maternal blood is associated with thrombosis in the placental vessels and a high rate of fetal loss. We followed six pregnancies in four mothers positive for lupus anticoagulant autoantibody with Doppler umbilical flow studies. The women were not treated with any drugs, and clinical management was guided by close fetal surveillance including umbilical flow studies. Umbilical artery flow velocity waveforms detect vascular abnormalities in the fetal umbilical placental circulation and were used as an early indicator of developing disease. All pregnancies produced live-born infants. These cases indicate the potential value of such studies in the management of this group at high risk of fetal loss.

Autoantibodies↗
PubMed1987

Umbilical artery flow velocity waveforms in high-risk pregnancy. Randomised controlled trial.

300 patients at high fetal risk (mean gestational age 34 wk) were randomised to a group for antenatal doppler umbilical artery waveform studies and a control group. The timing of delivery was similar in the control and doppler-report-available groups overall. However, in the report group obstetricians allowed the pregnancies of those not selected for elective delivery to continue longer. There was no difference in the rates for elective delivery (induction of labour or caesarean section) in the two groups, whereas among those who went into labour (induced or spontaneous) emergency caesarean section was more frequent in the control group (23%) than in the report group (13%). Fetal distress in labour was also more common in the control group. Babies from the control group spent longer in neonatal intensive care (level 3) and needed more respiratory support than did those in the report group. The findings indicate that the availability of doppler studies leads to better obstetrical decision making.

Blood Flow Velocity↗
PubMed1987

Spin echo imaging of multiple chemical shifts.

A method to obtain separate cross-sectional NMR images of chemically different species on the basis of their difference in chemical shift is presented. The total experiment time is no longer than that required for a conventional image and the method retains the full sensitivity of a spin-echo 2DFT imaging experiment. Simple addition of the chemical-shift selective images produces an image free from chemical-shift artifacts. Results of an in vivo experiment on a human subject are presented.

Body Water↗
PubMed1987

Umbilical artery flow velocity waveforms and placental resistance: the effects of embolization of the umbilical circulation.

Embolization of the umbilical placental circulation in fetal lambs was carried out to occlude the small vessels of the placental vascular bed and to observe the effect on the umbilical artery flow and flow velocity waveforms. Thirteen singleton fetuses were studied from day 120 of pregnancy. Embolization was achieved by injecting approximately 9 X 10(6) microspheres of 15 micron diameter into the fetal placental cotyledons along the umbilical arteries over 9 days. Umbilical and uterine flows were measured by radioactive microsphere counting. The umbilical placental resistance was increased (0.25 to 0.35 mm Hg.ml.min-1) by embolization, and there was an increase in the umbilical artery systolic/diastolic ratio. Embolization produced a significant fall in umbilical flow expressed either as total flow (312 to 237 ml.min-1) or when normalized by reference against splanchnic flow (3.36 to 1.53). We conclude that the umbilical artery flow velocity waveform systolic/diastolic ratio measures the reflection coefficient at the peripheral vascular bed (the "resistance vessels") of the placenta.

Animals↗
PubMed1975

Phylogeny of complement components in non-human primates.

The antigenic properties and functional activities of complement components were analyzed in primates to determine their relative evolutionary development. The sera of eight different sub-human primate species were examined by double diffusion in agar and compared to a pool of human serum with rabbit and goat antisera to human complement components Clq, Cls, C4, C2 C3, C5, C6, C8, C9, properdin, factor B (B), and C1 inhibitor. There are no apparent antigenic differences in complement proteins between man and the apes except for C1q. Old world monkeys are antigenically deficient in Clq,C1s, C9, and variably deficient in C4, C3, and C8. New World monkeys are antigenically deficient in all components (measured) except C5, C6, and properdin factor B. Prosimians are antigenically deficient in all components. Functional analyses of complement components showed similar levels in man and primates, except in prosimians. There is a dissociation between hemolytic assays and antigenic analyses, suggesting that functional sites may be separate from antigenic sites.

Absorption↗
PubMedDate not supplied

Optimizing the diagnosis of hippocampal sclerosis using MR imaging.

PURPOSE: To establish the optimal imaging parameters and MR features of hippocampal sclerosis. METHODS: Twenty-five outpatients with intractable temporal lobe epilepsy and 10 control subjects were studied at 1.5T. Four features of hippocampal abnormality were specifically evaluated; increased hippocampal signal on T2-weighted images, decreased signal on T1-weighted images, hippocampal atrophy, and disruption of the internal hippocampal structure. RESULTS: Hippocampal sclerosis was diagnosed alone in 64% of patients and with ipsilateral pathology in a further 8%. In these 18 cases, increased hippocampal signal on T2-weighted images was seen in 77%, hippocampal atrophy in 83%, decreases signal on T1-weighted images in 83%, and disruption of the internal hippocampal structure in 89%. No abnormality was reported in any of the 10 control cases. CONCLUSIONS: Four MR features diagnostic of hippocampal sclerosis are reported. Inversion recovery images are very useful for identifying decreased signal in the hippocampus and loss of internal structure within the hippocampus. Based on an appreciation of these four features in optimized images, hippocampal sclerosis can be diagnosed with a high degree of accuracy and sensitivity.

Adolescent↗