Search PubMed⌕ Search

Biomedical subjects

R W Beard

Publications and source records attributed to R W Beard.

At least 37 records · Page 2Linked to original sources
PubMed1996

The standard primipara as a basis for inter-unit comparisons of maternity care.

OBJECTIVE: To assess the suitability of the standard primipara (a subset of the obstetric population that has relatively low risk or intervention and of adverse outcome) for making inter-unit comparisons of indicators of the process and outcome of maternity care. DESIGN: Inter-unit comparison of 10 indicators of obstetric intervention and adverse outcome derived from routinely collected computerised data held on the St Mary's Maternity Information System. SETTING: Fifteen maternity units in the former North West Thames Region. PARTICIPANTS: 15,463 primiparae who were delivered in 1992. MAIN OUTCOME MEASURES: Proportion of primiparae within the standard definition; degree to which standard primiparae are associated with lower rates of intervention and adverse outcome, as compared to other primiparae. RESULTS: Within the database, 42.6% of all primiparae were found to be standard, with rates varying between units from 25.9% to 57.7%. As expected, the standard primiparous woman is at less risk of intervention or adverse outcome than other primiparae. All but one component variable of the standard definition is a significant risk factor for at least four of the 10 indicators. Statistically significant differences in indicator rates are seen between standard and nonstandard primiparae within units. Within the standard group, significant differences in rates of intervention and adverse outcome are seen between units. Units with relatively high levels of intervention within the higher risk nonstandard group also have relatively high levels of intervention within the standard group. CONCLUSIONS: Use of the standard primipara, rather than the whole obstetric population, as the basis for inter-unit comparisons of maternity care will control for the substantial difference in case mix seen in different units, thereby increasing the validity of those comparisons. The technique has the additional benefit of clarifying the relationship between everyday clinical decision making and a unit's performance in comparative indicator reports. The approach must be combined with a separate study of the other groups in the case mix, such as multiparae and high risk primiparae. Additional nonoverlapping groups, homogeneous in terms of risk factors, should be defined and used to extend the basis on which comparisons may be made.

Adult↗
PubMed1995

Remediation of pain-related memory bias as a result of recovery from chronic pain.

Cognitive biases are increasingly implicated as vulnerability factors in emotional and physical disorders. This issue is examined here in chronic pain sufferers using a recall memory paradigm. A sample of chronic pelvic pain patients undergoing hysterectomy and oophorectomy were assessed prior to the intervention, 8 weeks post-surgery, and again 6 months post-surgery. On each occasion patients were aurally presented four mixed lists of sensory, affective, neutral and gardening words, matched for frequency and length. No difference in the recall of neutral and gardening words was found, suggesting that selective memory for pain-related information cannot be attributed to superior recall of words belonging to a common semantic category. A clear pattern of more pain-related words being remembered before surgery, but better recall of non-pain-related words 6 months post-surgery when pain intensity ratings are significantly reduced, was evidenced. These results suggest that selective memory for pain-related words is more likely to be a secondary consequence of the long term experience of pain than a stable, enduring cognitive vulnerability factor.

Adult↗
PubMed1995

Substance P: endothelial localization and pharmacology in the human ovarian vein.

OBJECTIVE: To investigate the possible role of substance P as an endothelial factor in the local regulation of vascular tone in the human ovarian vein. METHODS: We performed immunolocalization of substance P in human ovarian venous endothelium in situ and in culture, and observed responses to substance P in preconstricted ring preparations of human ovarian vein in the presence of either the prostaglandin synthesis inhibitor indomethacin or the inhibitor of nitric oxide synthesis L-nitro arginine methyl ester (L-NAME), with and without luminal rubbing. RESULTS: Substance P was localized in a subpopulation of ovarian vein endothelial cells. Maximal relaxation induced by substance P was not significantly affected by indomethacin (10 mumol/L), but was reduced from 58.7% (95% confidence interval [CI] 41.3-76.1) in control experiments to 24.7% (95% CI 18.3-31.1) after luminal rubbing and to 32.3% (95% CI 19.8-44.8) after exposure to L-NAME (0.1 mmol/L) (P = .001). CONCLUSION: The localization of substance P in ovarian vein endothelium together with vasodilator effects mediated partially via the endothelium suggests that the peptide has a role in the local control of vascular tone in this vessel.

Adult↗
PubMed1995

Insulin secretion and sensitivity in women fulfilling WHO criteria for gestational diabetes.

Abnormalities of insulin secretion rather than insulin sensitivity are described in women fulfilling the American criteria for gestational diabetes. We examined insulin secretion and insulin sensitivity in 38 women at risk of gestational diabetes categorized according to the less stringent WHO criteria, based on the 75 g oral glucose tolerance test, performed at 24 weeks gestation. Insulin sensitivity was assessed at 28 and 36 weeks using the short insulin tolerance test. Applying WHO criteria, 18 women had GDM. Age and body mass index of the GDM and glucose tolerant women were similar (32.4 +/- 1.1 (SE) vs 32.3 +/- 1.9 yr; 28.7 +/- 1.5 vs 28.8 +/- 1.7 kg m-2, respectively). Fasting glucose was higher in the GDM women than controls (5.1 +/- 0.2 vs 4.5 +/- 0.1 mmol l-1, p < 0.025) while fasting insulin was similar (75 +/- 18 vs 90 +/- 16 pmol l-1). The 30-min insulin concentration during the OGTT was lower in the GDM women than controls (436 +/- 61 vs 788 +/- 152 pmol l-1, p < 0.05), while the insulin sensitivity at 28 (87 +/- 5 vs 76 +/- 5 mumol l-1 min) and 36 weeks (73 +/- 8 vs 76 +/- 8 mumol l-1 min) was similar. A negative correlation existed between the 30-min insulin and 120-min glucose concentration during the OGTT (Rho -0.328, p < 0.05). The WHO criteria for GDM identify women with similar abnormalities of insulin secretion as the more stringent American criteria.

Adult↗
PubMed1995

Management of women presenting to the accident and emergency department with lower abdominal pain.

The diagnosis and management of lower abdominal pain is difficult, particularly for the inexperienced accident and emergency (A&E) or surgical trainee. In women, potential gynaecological causes may further confuse the picture. We analysed the incidence, spectrum of presentation and immediate management of 322 women presenting consecutively to an inner city A&E department over a 6-month period with lower abdominal pain. A standard questionnaire relating to history, examination, immediate investigations and preliminary diagnosis was completed by the attending A&E doctor. The cause of abdominal pain, according to the A&E doctor's diagnosis, was gynaecological in 61%, gastroenterological in 23%, urological in 7% and non-specific in 9% of cases. Of the women, 39% (124/322) were referred to a duty specialist, of whom 86% (107/124) required admission for investigation and/or treatment. Women initially diagnosed as having pain of gynaecological origin formed the largest group of patients to be referred. In 69% (67/97) of these cases, the A&E doctor's initial diagnosis was confirmed by the gynaecologist. This study shows that pain of gynaecological origin was the largest single cause of lower abdominal pain in women presenting to our A&E department and that, in the majority of cases, these women needed to be referred to the duty gynaecologist for immediate treatment. Although overall diagnostic accuracy rate was relatively high, the management of potentially life-threatening gynaecological conditions such as ectopic pregnancy was poor. These results emphasise the need to improve in-service gynaecological training in A&E departments.

Abdominal Pain↗
PubMed1994

The future of obstetrics and gynaecology in Europe.

There is a general recognition that the health of women in Europe can be improved by collaboration between obstetricians and gynaecologists in EU and EFTA countries. The way in which collaborative approaches are developing are discussed, including the problems that have to be addressed if such an initiative is to be successful.

European Union↗
PubMed1994

Correction of the non-uniform spatial sensitivity of electrical impedance tomography images.

One of the clinical applications of electrical impedance tomography (EIT) is the measurement of volume changes of body fluids. However, the spatial sensitivity of images produced by the Sheffield Mark I system is non-uniform and if quantitative comparisons of resistivity images resulting from volume changes are to be mad, this non-uniformity must be corrected for. All experimental data were collected from a phantom consisting of semi-permeable membrane tubes fixed vertically at different distances from the centre of a cylindrical tank which was filled with a saline solution of resistivity 5 omega m. Individual images were obtained when each tube was filled with a saline solution of resistivity 1.5 omega m. Analysis of these images, using the resistivity integral described by Thomas et al, yielded the sensitivity of EIT at different positions within the tank. Combinations of tubes were then filled with saline (1.5 omega m) and an image produced for each combination. Cross sections of the images were taken and used to confirm that the principle of superposition is valid for EIT. A simple pixel scaling correction, derived from the sensitivity data, was then applied to the images and the results re-analysed to demonstrate a reduction in volume measurement error. The application of this correction to in vivo images is discussed.

Electric Impedance↗
PubMed1994

Fetal proinsulin and birth weight.

In both diabetic and non-diabetic pregnancies fetal insulin is an important anabolic hormone. Fetal hyperinsulinaemia is associated with accelerated fetal growth and increased birth weight. Insulin and C-peptide concentrations in both umbilical cord and amniotic fluid reflect fetal beta-cell secretion and are correlated with birth weight. In the present study umbilical venous proinsulin and insulin concentrations were measured in 54 term infants born to women with and without mild disturbances of glucose tolerance. Umbilical venous cord proinsulin, assayed using a highly specific immunoradiometric assay, was independently correlated with infant birth weight (Rho = 0.53, p < 0.0001) and birth percentile (Rho = 0.65, p < 0.0001). The correlation between birth weight and birth percentile weight with umbilical venous insulin, measured using a non-specific insulin assay, was lost following correction for the influence of proinsulin. Umbilical venous cord proinsulin appears to be a good indicator of fetal beta-cell activity, and in this study, a superior marker to insulin assayed using a non-specific insulin radioimmunoassay. The longer half-life of proinsulin compared with insulin may contribute to proinsulin being a more robust marker of overall fetal beta-cell activity than insulin.

Adult↗
PubMed1994

Reduced postprandial energy expenditure in women predisposed to type 2 diabetes.

Type 2 (non-insulin dependent) diabetes is so common that it has been hypothesized that in the course of evolution the predisposition to it may have conferred some advantage, before or during the reproductive years. It is frequently preceded by gestational diabetes. In order to test the basis for the hypothetical advantage, energy expenditure was investigated in 10 women with documented transient diabetes in a previous pregnancy. They were studied early in a subsequent pregnancy while glucose tolerance wa still normal and 9 were re-studied after pregnancy. Their results were compared with normal matched controls. During pregnancy, resting energy expenditure was similar in the study group and controls (6.58 (5.77-7.55) median (range) vs 6.91 (6.56-7.36) MJ day-1, respectively). However, the energy response to a mixed meal (42 kJ, kg-1 lean body mass) was decreased in the study group (45 (33-68) vs 76 (50-89) kJ, p < 0.05). After pregnancy resting energy expenditure was again similar in the two groups, but the decrease in postprandial thermogenesis persisted (78 (59-84) vs 92 (79-105) kJ, p < 0.05). The patients were resistant to exogenous insulin, 0.05 U kg-1 intravenously (slope of the plasma glucose decline in the 15 min after insulin; during pregnancy patients 52 (37-92) vs controls 111 (104-121) mumol l-1 min-1, p < 0.01; after pregnancy 130 (88-156) vs controls 186 (152-221) mumol l-1 min-1, p < 0.01). The postprandial energy saving in these women could constitute an evolutionary advantage. Insulin resistance may be the mechanism for limiting postprandial thermogenesis.

Adult↗
PubMed1994

Chronic pelvic pain caused by residual ovaries and ovarian remnants.

OBJECTIVE: To determine the diagnostic effectiveness and treatment of women with chronic lower abdominal pain due to residual ovaries or ovarian remnants. DESIGN: A prospective observational study. SETTING: Tertiary referral pelvic pain clinic. SUBJECTS: Seventeen women complaining of chronic pelvic pain of up to 25 years' duration, of whom seven had residual ovaries and 10 ovarian remnant(s). MAIN OUTCOME MEASURES: Persistent lower abdominal pain, pelvic tenderness and quality of life one year post-operatively. RESULTS: Six of the seven women with residual ovaries, and nine of the 10 women with presumed ovarian remnants experienced relief of the original pain, loss of pelvic tenderness and an improved quality of life. CONCLUSIONS: Residual ovaries after hysterectomy and ovarian remnants are established causes of chronic pelvic pain. Diagnosis and surgical removal is frequently difficult. Management strategies are proposed for both conditions.

Adult↗
PubMed1994

Pharmacology of the human ovarian vein: responses to putative neurotransmitters and endothelin-1.

OBJECTIVE: An investigation of excitatory vascular responses in the human ovarian vein, a blood vessel normally exposed to high concentrations of ovarian steroid hormones and capable of adaptation to circulatory changes associated with reproductive life. DESIGN: Pharmacological responses of surgical specimens of human ovarian vein to electrical field stimulation of sympathetic nerves, noradrenaline, alpha,beta-methylene adenosine 5'-triphosphate (alpha,beta-MeATP), endothelin-1 (ET-1), and 5-hydroxytryptamine (5-HT) were studied. Comparisons were made between in vitro pharmacological responses and the diagnostic category, age, smoking status, reproductive history and hormonal status of patients. SETTING: Research laboratory. RESULTS: Maximal contractile responses in longitudinal preparations, expressed as a percentage of the response to potassium chloride 125 mmol l-1, were 28% (SE 7.2) to electrical field stimulation and 107% (SE 15.1) to noradrenaline. In ring preparations, maximal responses to various agents were: noradrenaline 93% (SE 10.2); 5-HT 79% (SE 8.0); alpha,beta-MeATP 48% (SE 8.4); and ET-1 87% (SE 10.1). pD2(-log EC50) values for noradrenaline were 5.82 (SE 0.21) in longitudinal preparations and 5.65 (SE 0.10) in ring preparations; for ET-1 in ring preparations these values were 7.88 (SE 0.74). Responses to sympathetic nerve stimulation were attenuated by the adrenoceptor antagonist phentolamine; any residual responses were blocked by desensitisation of P2-purinoceptors with alpha,beta-MeATP or the addition of suramin, indicating that noradrenaline and adenosine 5'-triphosphate may be co-transmitters in these nerves. pD2 values for 5-HT were 5.97 (SE 0.12) in specimens from unsterilised patients (n = 19) compared with 5.20 (SE 0.24) in specimens from those who had previously undergone sterilisation (n = 6) (P < 0.05). No other relation between clinical characteristics and pharmacological responses were detected and, in particular, there were no apparent changes associated with ageing or hormonal status. CONCLUSIONS: Three main conclusions may be drawn from this study: (1) adenosine 5'-triphosphate is a co-transmitter in sympathetic nerves in the human ovarian vein; (2) tubal sterilisation affects vascular responsiveness to 5-HT; and (3) ovarian steroid hormones are likely to influence sympathetic vascular control via effects on catecholamine and adenosine 5'-triphosphate synthesis, storage, release, degradation or re-uptake, rather than via effects on vascular smooth muscle receptors.

Endothelins↗
PubMed1994

The quality of routinely collected maternity data.

OBJECTIVE: To assess the validity of clinical information held on a regional maternity database, the St Mary's Maternity Information System (SMMIS). DESIGN: A retrospective review of 892 maternity case notes and matched SMMIS records, by a midwife trained in clinical coding techniques. SETTING: Three maternity units in the North West Thames Region. MAIN OUTCOME MEASURES: Percentage agreement for 17 directly recorded SMMIS data items and equivalent data abstracted from the notes. Frequencies of diagnosis codes abstracted from case notes, as compared with those generated by SMMIS on the basis of directly recorded data. RESULTS: A generally high level of agreement was observed between the abstracts of the notes and the SMMIS records. Of the 17 data items examined, 10 showed 95% agreement or better, and all but two exceeded 80% agreement. Little difference was found between the levels of agreement observed at the three sites. A greater number and range of diagnosis codes were abstracted from the notes than were generated by SMMIS. CONCLUSIONS: The directly recorded clinical data held on the SMMIS regional database is largely accurate and consistently recorded across a variety of units. The database can therefore be considered a valuable resource for the comparative audit of maternity practice. The SMMIS technique for deriving, on a semi-automatic basis, diagnosis codes from the directly recorded fields, appears to work moderately well. We suggest that the direct method of data collection used in SMMIS could provide a model for other specialties in the National Health Service.

Data Collection↗
PubMed1994

What is the optimal caesarean section rate? An outcome based study of existing variation.

STUDY OBJECTIVE: To investigate the consequences of different levels of caesarean section (CS) rate in terms of fetal and maternal outcomes. DESIGN: Comparison of outcome variables between four categories of maternity units stratified according to CS rates. Data were collected concurrently. SETTINGS: All 17 maternity units in one health region. SUBJECTS: Data for the perinatal mortality analysis: all 221,867 deliveries in 1983-87 (excluding severe malformations) (1462 deaths); maternity information analysis system: all 36,727 women with singleton pregnancies who delivered in 1988. OUTCOME MEASURES: Perinatal mortality, Apgar scores at one and five minutes, onset of respiration after one minute, postnatal transfusion, postnatal infection, thromboembolism, low haemoglobin concentration at discharge, and puerperal psychosis were determined. RESULTS: Teaching hospitals with an increased proportion of high risk cases had the highest CS rate, but the other three categories were found to serve comparable populations. Perinatal mortality showed a birthweight specific pattern--for very low birthweight infants, but not for other deliveries, mortality rates were lower in units with higher CS rates. Apgar scores showed no trend, but the onset of respiration after one minute was significantly more frequent in units with a CS rate of less than 10%. Increased maternal postnatal blood transfusion was associated with higher CS rates but no trend was observed for the other maternal variables. CONCLUSIONS: CS rates in general maternity units should be 10 to 12% or lower in the singleton population as a whole, but a more interventionist approach is indicated for very low birthweight infants. If confirmed, these recommendations could easily be incorporated into clinical audit.

Apgar Score↗
PubMed1994

Hypersecretion of androstenedione by isolated thecal cells from polycystic ovaries.

The aim of this study was to examine the hypothesis that hypersecretion of ovarian androgens in polycystic ovary syndrome results from an intrinsic abnormality of androgen biosynthesis by thecal cells. Steroid accumulation by human thecal cells from normal and polycystic ovaries (PCO-theca) was examined under basal and LH-stimulated conditions. A method for dispersing and culturing human thecal cells as primary monolayers in serum-free medium was developed. LH increased androstenedione (A), progesterone (P), 17 alpha-hydroxyprogesterone, dehydroepiandrosterone, and estradiol accumulation in the overlying medium in a dose-dependent manner at a maximum effective dose of 2.5 ng/mL. The principal variables affecting the magnitude of steroid accumulation were plating density, duration of incubation, and follicle size. Using only theca from follicles less than 10 mm and keeping plating density constant, 48-h steroid production by theca from five normal ovaries was compared to that from nine polycystic ovaries isolated from both anovulatory and ovulatory women. There was a significant increase in both basal (median, 32.1 pmol/1000 cells.48 h; range, 18.7-250) and LH-stimulated (56 pmol/1000 cells; range, 40.7-406) A accumulation by PCO-theca compared to basal (1.7 pmol/1000 cells; range, 1.1-4.3) and LH-stimulated (2.8 pmol/1000 cells; range, 2.0-8.1) A accumulation by normal theca, with no overlap in values between the two. Although P production was also increased in the PCO-theca, the A to P ratios under both basal and LH-stimulated conditions were significantly higher in the PCO-theca [A/P ratio normal; PCO basal, 0.1 and 0.53 (P < 0.01); LH-stimulated, 0.04 and 0.65 (P < 0.001)], suggesting increased conversion of P to A. The steroid response to LH was similar in both groups. This is the first report of a difference in thecal androgen production between normal and polycystic ovaries and supports the hypothesis that there is a primary abnormality in the regulation of androgen production in PCOS.

Adult↗