Search PubMed⌕ Search

Biomedical subjects

P M O'Brien

Publications and source records attributed to P M O'Brien.

At least 55 records · Page 3Linked to original sources
PubMed1994

Outcome of twin pregnancies complicated by a single intrauterine death: a comparison with viable twin pregnancies.

OBJECTIVE: To examine the perinatal and maternal outcomes in twin pregnancies when a single intrauterine death occurs. METHODS: This was a retrospective, observational study. Comparison was made to viable twin pregnancies. RESULTS: Of a total 34,804 live deliveries, 342 were documented as twin births at a gestation of greater than 20 weeks (incidence 0.98%). Of the twin pregnancies over this period, 20 (5.85%) were complicated by a single intrauterine death. There was an increase in the incidence of congenital structural abnormalities among those twins dying in utero as compared to uneventful twin pregnancies (25 versus 0.3%; P < .001). A significant proportion of these twin pregnancies had monochorionic placentas (35 versus 9%; P < .001) and were admitted to special care units (70 versus 5.6%; P < .001) as compared to the normal twin sample. Maternal morbidity has previously been described as being increased. Although there was an increased risk of nonproteinuric and mild pregnancy-induced hypertension, no adverse maternal effects of conservative management were noted in this study. CONCLUSION: The risk of a single fetal death in twin pregnancies is increased with a monochorionic placenta or a structural abnormality. Conservative management and regular surveillance seem advisable.

Birth Weight↗
PubMed1993

A randomised prospective study comparing the new vacuum extractor policy with forceps delivery.

OBJECTIVE: To compare assisted vaginal delivery by forceps with delivery by vacuum extractor, where a new vacuum extractor policy was employed which dictated the cup to be used in specific situations. DESIGN: Multicentre randomised controlled trial. SETTING: Four district general hospitals in the West Midlands. SUBJECTS: Six hundred-seven women requiring assisted vaginal delivery, of whom 296 were allocated to vacuum extractor delivery and 311 to forceps. MAIN OUTCOME MEASURES: Delivery success rate, maternal perineal and vaginal injuries, maternal anaesthetic requirements, neonatal scalp and facial injuries. RESULTS: Of the vacuum extractor group, 85% were delivered by the allocated instrument compared to 90% in the forceps group (odds ratio (OR) 0.64; 95% confidence intervals (CI) 0.4-1.04). However, more women in the vacuum extractor group were delivered vaginally (98%) than in the forceps group (96%). There were significantly fewer women with anal sphincter damage or upper vaginal extensions in the vacuum extractor group (11% vs 17%, OR 0.6; 95% CI, 0.38-0.97). There were significantly fewer women in the vacuum extractor group requiring epidural or spinal anaesthetics (25.4% vs 32.7%, OR 0.69; 95% CI 0.49-0.99) or general anaesthetics (1% vs 4%, OR 0.17; 95% CI 0.04-0.76). Although there were significantly more babies in the vacuum extractor group with cephalhaematomata (9% vs 3%, OR 3.3; 95% CI 1.4-7.4) there were fewer babies in the vacuum extractor group with other facial injuries. There were three babies in the forceps group with unexplained neonatal convulsions. CONCLUSIONS: Assisted vaginal delivery using the new vacuum extractor policy is associated with significantly less maternal trauma than with forceps. Further studies are required to assess neonatal morbidity adequately.

Adult↗
PubMed1992

Buserelin in premenstrual syndrome.

Buserelin, a luteinizing hormone releasing hormone agonist was administered nasally in doses of 900 micrograms daily to inhibit the ovarian cycle. Of 16 patients recruited, ten completed the treatment. Daily symptoms were measured on the Visual Analogue Scale and Trigg's trend analysis utilized for the analysis. The peak severity of symptoms (ESAmax) and the maximum global scores (Gmax) reduced on buserelin treatment. The minimum global scores (Gmin) and the minimum score for each symptom (ESAmin) increased, suggesting worsening of underlying symptoms. The difference between ESAmax and ESAmin (ESAdelta) and Gmax and Gmin (Gdelta) were calculated to determine the degree of symptom change. The delta scores for symptoms of depression, bloatedness and breast symptoms, and Gdelta were significantly reduced (p less than 0.05) on buserelin, whilst the latter significantly worsened in the follow-up months. Side-effects may limit the place of buserelin in the long-term treatment of premenstrual syndrome, although combination of additional hormonal treatment may facilitate long-term treatment.

Administration, Intranasal↗
PubMed1991

Evaluation of the roll over test as predictor of gestational hypertension in African women.

Fifty-six primigravid women at 28-32 weeks gestation were studied prospectively to assess the roll over test (ROT) as a predictor of gestational hypertension in African women. Blood pressures were measured continuously in the supine and left lateral positions using an automated accutor machine. ROT was positive in only two women (3.6%). These two women later developed gestational hypertension but so did 18 others who had negative ROT. Measures that may be useful in increasing the predictive value of the ROT in these women are suggested.

Blood Pressure Determination↗
PubMed1991

Cloning and sequencing of the cDNA for ovine granulocyte-macrophage colony-stimulating factor (GM-CSF).

Colony-stimulating factors (CSFs) are not only regulators of haemopoiesis but can also enhance the function of mature myeloid cells, and are therefore potential immune adjuvants. By use of the polymerase chain reaction (PCR) with primers based on the bovine granulocyte-macrophage CSF (GM-CSF) sequence, we have amplified the cDNA for ovine GM-CSF, produced from crude mRNA extracted from alveolar macrophages. The PCR product was cloned into pUC119, and electroporated into Escherichia coli. The complete nucleotide sequence of two clones, and the partial sequence of eight others, was determined. At the nucleotide and amino acid levels, the ovine and bovine GM-CSF sequences are 91% and 81% homologous, respectively.

Amino Acid Sequence↗
PubMed1990

Patient-recorded domiciliary fetal monitoring.

Domiciliary fetal monitoring via a telephone link has been in clinical use at the Royal Free Hospital for 2 years, during which time 858 traces of 134 patients who were moderately at risk have been transmitted to the hospital. All recognized abnormal heart rate patterns were detected during the study period. In seven patients obstetric intervention took place on the basis of the domiciliary fetal monitoring recording and subsequent hospital monitoring. There were no intrauterine or neonatal deaths, and there was no overall increase in obstetric operative intervention. There appeared to be a significant reduction in the inconvenience suffered by the patient and her family, compared with conventional monitoring. Fetal heart recordings performed solely by the patient were of a high quality and reduced the demand on midwifery resources. To allow this only 3 hours of midwifery time daily was required and no additional demands on obstetric staff were made. It is anticipated that domiciliary fetal monitoring, performed by patients, will become an essential and established service throughout the United Kingdom (and probably Europe) as the principal means of monitoring fetal well-being.

Adult↗
PubMed1990

Reduced atrial natriuretic peptide concentrations in premenstrual syndrome.

Atrial natriuretic peptide (ANP) concentrations were determined by radioimmunoassay technique in 23 women, 11 women with premenstrual syndrome (PMS) and 12 comparable asymptomatic women. The asymptomatic women showed no change in ANP concentration during the menstrual cycle. In the PMS group ANP levels showed a significant fall in the midluteal phase compared to levels in the follicular phase. Throughout the cycle ANP concentrations were lower in the PMS group than in the comparison group. This difference was statistically significant in the early, mid and late luteal phases of the cycle. The lower ANP concentration in the PMS group in the luteal phases may indicate either a lower plasma volume or a decrease in the total body sodium content or both. These findings are contrary to those expected.

Adult↗
PubMed1990

Assessment of menstrual blood loss using a pictorial chart.

Objective menstrual blood loss measurements (in ml) were compared with the score obtained from a pictorial blood loss assessment chart (PBAC) which took into account the degree to which each item of sanitary protection was soiled with blood as well as the total number of pads or tampons used. Twenty eight women used the chart during 55 menstrual cycles and a single observer assessed 122 cycle collections in a similar manner. A pictorial chart score of 100 or more, when used as a diagnostic test for menorrhagia, was found to have a specificity and sensitivity of greater than 80%. Demonstration of the relation between self assessed pictorial chart scores and the objective measurement of blood loss enables us to provide a simple, cheap and reasonably accurate method of assessing blood loss before embarking upon treatment.

Adult↗
PubMed1990

Elevated viral antibody titres in spontaneous abortion.

To assess the possible role of virus infections in spontaneous abortion we undertook a prospective study of three groups of patients: women who had a spontaneous abortion; women seen in the antenatal booking clinic; and those undergoing therapeutic termination of pregnancy. Venous blood was taken for antibody detection, cervical swabs for virus isolation, and in the cases of spontaneous and therapeutic abortion products of conception were sent for virus culture. The infectious agents studied were influenza A and B, adenovirus, respiratory syncytial virus, measles, psittacosis, Varicella zoster, and mumps virus. Statistical analysis revealed that women in the spontaneous abortion group has a higher incidence of antibodies against respiratory syncytial virus (P less than 0.01), and mumps virus (P less than 0.01). Among women seropositive for each virus, higher titres were found only for respiratory syncytial virus (P less than 0.05) in cases rather than controls. These results could be explained if viruses such as respiratory syncytial virus caused abortion or if women having a spontaneous abortion mount exaggerated immune responses to fetal and viral infections, and the former altered immune response is associated with spontaneous abortion.

Abortion, Spontaneous↗
PubMed1990

Does standing up improve the predictive value of the supine pressor test for gestational hypertension?

Fifty-six primigravid women at 28-32 weeks' gestation were studied prospectively to compare the roll-over test with the stand-up pressor test in the prediction of gestational hypertension. Blood pressures were measured in the different positions continuously using an automated machine. Twenty patients developed gestational hypertension; two of these were accurately predicted by roll-over test and six by stand-up pressor test (P less than .001). However, there was no significant difference between the tests in the rates of false negatives, specificity, and negative and positive predictive values. Concomitant measurement of blood pressures in the standing position may increase the sensitivity of the roll-over test for the prediction of gestational hypertension.

Adolescent↗
PubMed1989

Prostacyclin attenuates both the pressor and adrenocortical response to angiotensin II in human pregnancy.

1. The effects of angiotensin II (ANG II) infusion without and with simultaneous infusion of prostacyclin (PGI2; 1.4 pmol min-1 kg-1; 5 ng min-1 kg-1) have been studied in 16 women in second-trimester pregnancy. Ten received one infusion of ANG II alone, followed by its infusion together with PGI2; the remainder received two identical infusions of ANG II alone as controls. 2. PGI2 administration was associated with a small fall in diastolic pressure (P less than 0.01) and a proportionally greater rise in heart rate (P less than 0.001). Small rises in basal plasma renin and ANG II concentrations and a fall in aldosterone concentration were not statistically significant. 3. The diastolic pressor response to ANG II was blunted during PGI2 infusion by comparison with controls (P less than 0.025); this diminution in response was greatest in patients who had initially been most sensitive to ANG II (P less than 0.02). 4. The evoked increment in plasma aldosterone during ANG II infusion was considerably reduced (P less than 0.005) in the presence of PGI2. 5. These data further support the hypothesis of a role for PGI2 in relation to the blunted pressor response to ANG II of normal pregnancy. The apparent inhibitory effects of PGI2 on aldosterone secretion may partly explain the previously described dissociation between the renin-angiotensin system and aldosterone in pregnancy.

Adrenal Cortex↗
PubMed1989

Responses to mitogenic stimulation of lymphocytes taken during and after pregnancy.

Serial blood samples were collected during pregnancy, after delivery and several months postnatally from 28 women. The blastogenic responses of lymphocytes to varying concentrations of phytohaemagglutinin (PHA) were tested using autologous plasma or fetal calf serum (FCS) to support the lymphocyte cultures. Using FCS, the blastogenic response decreased as pregnancy progressed and remained depressed months after delivery. In contrast, when autologous plasma was used a 10-fold higher concentration of PHA was required to give optimal stimulation. Blastogenic responses were still suppressed during pregnancy but had returned to initial values by the time of delivery and were greater still in the post-partum and postnatal periods. We conclude that the inherent ability of lymphocytes to undergo blastogenesis is suppressed during pregnancy but that this is over-shadowed by a humoral effect of pregnancy plasma. The significance of these results is discussed.

Blood Physiological Phenomena↗
PubMed1988

Proton microscopy and microanalysis--biological applications.

Several nuclear and atomic techniques are available to a scanning proton microprobe for examining the elemental distributions and microstructure within a specimen. The instrument and its techniques are discussed together with some examples of non-destructive elemental microanalysis. The handling and display of quantitative maps and their relationship to regional spectra are shown with an emphasis in this paper on biological applications.

Elements↗
PubMed1988

A comparison of oral prostaglandin E2 tablets with intravenous oxytocin for stimulation of labor after premature rupture of membranes at term.

Sixty-nine patients (48 primigravidae and 21 multigravidae) with 12 hours of spontaneous premature rupture of membranes (PROM) after 36 weeks gestation were randomly allocated to receive either prostaglandin E2 (PGE2) oral tablets or intravenous oxytocin to stimulate labor. The two treatments were compared regarding stimulation - delivery interval (SDI), analgesic requirements, maternal and fetal side effects, and patient acceptability. The mean SDI was shorter in the oxytocin group, but without statistical significance. Analgesic requirements and fetal side effects were similar in the two groups, but there was a higher incidence of nausea and vomiting in those patients receiving the maximum dose (1 mg hourly) of PGE2. On subjective assessment, clinicians considered oxytocin to be more effective (p less than 0.05), while midwives felt both regimes to be equally helpful. PGE2 oral tablets were significantly (p less than 0.05) more acceptable to the patients, who preferred the convenience of oral dosing, the absence of an i.v. line and the increased mobility. It is concluded that PGE2 tablets are a safe and effective method of stimulating labor following PROM, and highly acceptable to parturients. In those women in whom labor has not been established within 8 h of initiating PGE2 therapy, or in whom gastric side effects are troublesome, intravenous oxytocin should be substituted.

Adolescent↗