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Biomedical subjects

N A Simpson

Publications and source records attributed to N A Simpson.

8 recordsLinked to original sources
PubMed2001

A survey of trainee obstetricians preferences for childbirth.

OBJECTIVE: To determine trainee obstetricians personal preferences regarding mode and place of delivery given various scenarios. STUDY DESIGN: An anonymous nationwide postal survey of 365 specialist registrars. RESULTS: The response rate was 76%. About 2.5% preferred a home birth. And 16% of men and 15% of women opted for elective cesarean section (CS). When faced with a proposed trial of instrumental delivery in theatre, 60% accepted and a further 12% accepted only if they could choose the obstetrician performing the delivery. Regarding a breech presentation at term, 78% would accept external cephalic version (ECV). CONCLUSIONS: The percentage of obstetricians who preferred vaginal delivery and ECV were considerably higher than previously reported, and there were no significant gender differences. This study shows a more balanced attitude from obstetricians and refutes the previously held view that they necessarily advocate high levels of intervention for themselves.

Attitude of Health Personnel↗
PubMed2001

A digital system for recording the electrical activity of the uterus.

The ability to identify true pre-term labour would be of considerable clinical benefit as electrical signals from the uterus, recorded using surface electrodes, may discriminate between labouring and non-labouring states in human pregnancy. A digital recording system for recording the electrical activity of the uterus has been developed and is described in this paper. A pilot study in which entire recordings in 21 women were subjected to power spectral analysis suggests that the relative power in two frequency bands (0.2-0.45 Hz and 0.8-3 Hz) changes as pregnancy progresses into early labour.

Adult↗
PubMed2001

The carriage of pro-inflammatory cytokine gene polymorphisms in recurrent pregnancy loss.

PROBLEM: Recurrent pregnancy loss (RPL) affects 2-4% of couples, and remains largely unexplained. Recent studies have examined the role of cytokines in the maintenance of normal pregnancy, which is linked with an increased expression of Th2 cytokines. Overexpression of Th1 cytokines is associated with RPL. Knowing that functional polymorphisms exist for certain cytokines, it has therefore been suggested that women with RPL may have a genetic predisposition to overexpress Th1 cytokines. METHOD OF STUDY: The genes for interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha) carry functional gene polymorphisms. In both cases these are biallelic polymorphisms that can be detected by polymerase chain reaction followed by restriction fragment length polymorphism. The aim of this pilot study was to assess whether carriage of the rarer alleles (TNF*2 and IL-1B*2) could act as independent risk factors in recurrent miscarriage. RESULTS: We found an increased incidence in the carriage of TNF*2, more pronounced in those women with two or more miscarriages. Carriage of the IL-1B*2 either alone or in association with TNF*2 was not associated with recurrent miscarriage. CONCLUSION: There may be a role for these cytokine gene polymorphisms in RPL.

Abortion, Habitual↗
PubMed2000

Thromboelastography identifies sex-related differences in coagulation.

UNLABELLED: Thromboelastography is an in vitro, point-of-care monitor of whole blood coagulation. Thromboelastography studies have demonstrated a hypercoagulable state during pregnancy. Perhaps the hypercoagulability is attributable to female sex hormones. The aim of the study was to determine if sex, in addition to pregnancy, affected thromboelastography variables by studying male and female (pregnant and nonpregnant) volunteers. Thromboelastography showed significant (P:<0.01) differences in sex, with a significant (P: < 0. 0001) trend of increasing whole blood coagulability from men through nonpregnant to pregnant women. The thromboelastograph, used as a diagnostic tool, shows that women have more whole blood coagulability than men. IMPLICATIONS: The thromboelastograph, used as a diagnostic tool, shows that women have more whole blood coagulability than men.

Adult↗
PubMed1998

Sonographic evaluation of intervillous flow in early pregnancy: use of echo-enhancement agents.

The uteroplacental circulation of the cynomolgus monkey was examined in early pregnancy using a high-resolution ultrasound scanner. Intravenous injection of an echo-contrast agent, Albunex (sonicated albumin), was used to enhance the color Doppler images obtained. The flow of blood into and out of the intervillous compartment was readily assessed and quantified using pulsed and color Doppler. Flow within the intracotyledonary space was pulsatile and indicative of a low-resistance system. Flow within the decidual veins was non-pulsatile. The use of echo-contrast agents may assist in the determination of intervillous flow in human pregnancy at a correspondingly early stage.

Albumins↗
PubMed1997

Determination of intervillous flow in early pregnancy.

The process of placentation in the macaque has been extensively studied and found to resemble closely that observed in the human. In this model, histopathologically, intervillous flow is anticipated from week 3 post-conception. We set out to document the nature and onset of intervillous flow in the macaque in vivo using colour Doppler imaging (CDI), colour Doppler energy (CDE) and pulsed-wave Doppler (PWD). Pregnant females were assessed between 15-50 days gestation (term = 165 days) with an Acuson 128/XP10 high-resolution ultrasound scanner, using a 7-MHz linear array probe. The placenta, subjacent decidua and myometrium were assessed using CDI and CDE. Specific regions of flow were interrogated using PWD; the resulting flow velocity waveforms were stored and quantified using conventional Doppler indices. B-mode sonography was able to demonstrate the well-defined placental-decidual interface observed in this species; CDI and CDE clearly visualized the uteroplacental vasculature. Spiral arteries were followed to their point of discharge into the intervillous space, and PWD at these sites obtained a characteristic flow velocity waveform. The indices obtained confirmed a flow of low resistance and pulsatility throughout the gestation studied. Flow within the intervillous space was noted from day 20 of gestation.

Animals↗