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Biomedical subjects

J M Pearce

Publications and source records attributed to J M Pearce.

At least 145 records · Page 8Linked to original sources
PubMed1993

An audit of general practitioner requests for pelvic ultrasound: analysis of referral patterns and outcome.

OBJECTIVES: 1. To assess the information supplied by general practitioners on the gynaecological ultrasound request form and to determine how this information influences the interpretation of scans; and 2. To examine the influence of scans on the subsequent management of patients both by general practitioners and, where relevant, by hospital gynaecologists. DESIGN: Retrospective analysis of gynaecological ultrasound requests made by general practitioners. Postal questionnaire and assessment of outcome according to general practitioners' records and, where appropriate, the hospital notes. SETTING: A London teaching hospital gynaecological ultrasound department and associated general practices. SUBJECTS: Four hundred ninety-eight women referred by general practitioners for a gynaecological ultrasound scan over a one year period (1990). RESULTS: The 498 requests for gynaecological ultrasound scans included 472 primary diagnostic referrals. Seventy-one percent of general practitioners replied to the questionnaires. Overall, 46% of the scans were normal, but the proportion of normal scans fell to 21% if the date of the last menstrual period and a pregnancy test result were included on the form. Forty per cent of women scanned subsequently were referred for hospital care. CONCLUSIONS: General practitioners would appear to use the ultrasound service in a rational way and therefore there can be no justification for not allowing them open access. The positive diagnostic yield can be further improved if time is taken to supply simple relevant information which may be facilitated by a specific request form.

Abortion, Threatened↗
PubMed1993

Natural history of cluster headache.

A follow-up study of 123 patients with episodic cluster headaches and of 9 patients with chronic cluster headaches was undertaken after 10-25 years, (mean 14.7 and 13.9 years respectively). This shows a significant but low remission rate for both episodic and chronic cluster headache. It confirms the observation that some patients change from episodic to chronic pattern, and that occasionally chronic clusters may become episodic.

Adult↗
PubMed1992

Effects of discrimination training on responding during a compound conditioned stimulus.

Four experiments examined responding in the presence of a triple-element compound ABC after discrimination training in which 2 compounds, AB and BC, signaled the delivery of food and 1 element alone, B, signaled the absence of food. In Experiments 1 and 2, using rats, responding during ABC was more vigorous than in a control group for which A and C but not B had been individually paired with food. This finding was replicated in Experiment 3, which used pigeons, and in Experiment 4, where all 3 stimuli of the control condition were individually paired with food. The results are more consistent with a configural than with an elemental theory of learning.

Animals↗
PubMed1992

Perineal video-ultrasonography in the assessment of vaginal prolapse: early observations.

OBJECTIVE: To investigate the efficacy of perineal ultrasonography in the assessment of vaginal prolapse. DESIGN: A prospective descriptive study. SETTING: Urodynamic Unit, St. George's Hospital, London. SUBJECTS: Six women, three of them were awaiting colposuspension and three had had a colposuspension. INTERVENTIONS: Perineal ultrasound scans were performed on women with and without incontinence and prolapse, both before and after continence surgery. Movement of the bladder, urethra, uterus, vaginal vault and enterocele were observed during coughing and the valsalva manoeuvre. MAIN OUTCOME MEASURES: To assess reproducibility, six patients had six different measurements taken of bladder neck and prolapse position and movement relative to the symphysis. The measurements were plotted upon an X-Y co-ordinate axis. Each measurement was repeated three times and one way analysis of variance performed upon the readings. RESULTS: Perineal ultrasonography clearly demonstrated movement of the whole pelvic floor. Minor degrees of both anterior and posterior vaginal wall prolapse could be seen and quantified. An increase in posterior vaginal wall mobility was noted in women after colposuspension. All measurements taken were found to be reproducible. CONCLUSIONS: Perineal ultrasonography is easy to perform and is reproducible. It may improve understanding of why some women develop posterior vaginal wall prolapse after colposuspension and, conversely, why some women develop incontinence following anterior repair for prolapse.

Cough↗
PubMed1992

Determinants of pregnancy heartburn.

OBJECTIVE: To study the prevalence and severity of reflux symptoms in pregnancy. DESIGN: Self-administered questionnaire detailing age, race, gestational age, parity, weight, height, symptoms and severity of gastro-oesophageal reflux. SETTING: An antenatal clinic in a teaching hospital. SUBJECTS: 607 consecutive women at various stages of pregnancy were recruited during attendance at antenatal clinic. RESULTS: The prevalence of heartburn increased with gestational age (22% in the first, 39% in the second, and 72% in the third trimester; P < 0.0001), as did severity of heartburn (P < 0.0001). Pharyngeal regurgitation as a symptom showed little increase during advancing pregnancy. Symptoms of heartburn rapidly increased towards the end of the second trimester. The decrease in heartburn traditionally expected during the last three weeks of pregnancy (fetal head descent) was not observed. Logistic regression analysis showed increased risk of suffering heartburn with increasing gestational age (P < 0.0001), pre-pregnancy heartburn (P < 0.0001), parity (P < 0.0001) and inversely with maternal age (P < 0.05) but not with body mass index before pregnancy, race, or weight gain in pregnancy. CONCLUSION: Heartburn, but less so pharyngeal regurgitation, increases in prevalence and severity with gestational age and parity. We speculate that hormone-related impairment of distal oesophageal clearance mechanisms may have a crucial bearing on whether heartburn develops in those individuals at greatest risk.

Adult↗
PubMed1992

A configural analysis for feature-negative discrimination learning.

In 4 experiments, rats were initially trained with an A+ AXo discrimination in which Stimulus A by itself signaled the delivery of food, A+, whereas the simultaneous presentation of A and X was followed by nothing, AXo. In each experiment X was then paired with food prior to a test phase in which A and X were again presented for a discrimination. The discrimination was of the form A+ AXo in Experiments 1 and 2, whereas it was of the form X+ AXo for Experiments 3 and 4. In all 4 experiments the test discrimination was acquired more rapidly than a control discrimination. The results are interpreted in terms of the original A+ AXo discrimination resulting in the growth of an association between a representation of the entire AX compound and the effects of nonreinforcement.

Animals↗
PubMed1991

Changes in platelet function in pregnancies complicated by fetal growth retardation.

Platelet function was investigated in three patients with severely decreased fetal growth rates detected by ultrasound scanning. Only one patient had hypertension, which was mild and developed after decreased fetal growth and altered platelet responses had been detected. Much higher concentrations of platelet-activating factor (PAF) (20-500 nM) were required to stimulate maximal platelet aggregation in all three patients compared with the concentrations of PAF (5-10 nM) required in control pregnancies of similar gestational age. In a fourth patient, platelet desensitisation was observed 5 weeks before the detection of decreased fetal growth. These results are similar to those observed in women with hypertensive disorders of pregnancy, and indicate that there may be a similar change in platelet function in gestational hypertension and in fetal growth retardation, although the clinical manifestations are different.

Blood Platelets↗