Search PubMed⌕ Search

Biomedical subjects

J M Pearce

Publications and source records attributed to J M Pearce.

At least 181 records · Page 10Linked to original sources
PubMed1990

Restless legs syndrome in pregnancy. Case reports.

Restless legs syndrome is a common complaint in pregnancy affecting up to one in every three women. The exact pathophysiology is poorly understood. The majority of patients respond to simple explanation and reassurance, however, a small proportion may suffer debilitating symptoms requiring drug therapy. We describe two such cases.

Carbamazepine↗
PubMed1990

Selective transfer of responding in conditional discriminations.

In each of three experiments rats received discrimination training in which whether or not a 10-sec target stimulus was followed by food was signalled by a 2-min background stimulus. In the first experiment the target was paired with food in the presence but not the absence of the background stimulus. Subsequent tests revealed that the background elevated responding to a target that had taken part in a similar discrimination. However, it had no influence on the responses elicited by a partially reinforced conditioned stimulus. In the remaining experiments the target was paired with food in the absence but not the presence of the background. Test trials then revealed that although the background had an inhibitory influence on the responses elicited by a target from a similar discrimination, it had no influence on the responses elicited by either a partially or a continuously reinforced conditioned stimulus. Various explanations for this selective influence of a background stimulus are considered.

Animals↗
PubMed1990

Configural associations in discrimination learning.

In 4 experiments, Sprague-Dawley rats and homing pigeons received training with an A+ AB0 BC+ discrimination, in which food (+) accompanied trials with A and BC. Food was not presented (0) on trials with the compound AB. Subsequent test trials revealed that responding during C by itself, or the compound ABC, was slower than during either A or BC. Responding during the ABC compound was also found to be slower after training with the A+ AB0 BC+ than an A0 AB+ BC+ discrimination. We argue that these findings demonstrate the importance of configural associations in discrimination learning. Two accounts for the way in which these associations exert their influence are considered.

Animals↗
PubMed1990

Oxytocin in active-phase abnormalities of labor: a randomized study.

Seven hundred fifty-nine of 926 women in abnormal labor (82%) were entered into an open randomized trial to compare the effects of oxytocin and saline. Patients were classified as having either primary dysfunctional labor or secondary arrest of cervical dilatation. The end points chosen were an increase in the rate of cervical dilatation or a change in cervical dilatation. Patients who failed to respond to the initial solution were crossed over to the other solution. Oxytocin was significantly superior to saline in treating both labor abnormalities. Administration of oxytocin did not increase the need for cesarean delivery for fetal distress.

Cesarean Section↗
PubMed1989

Lasegue's sign.

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed1989

Renal function and electrolyte levels in hyperthyroidism: urinary protein excretion and the plasma concentrations of urea, creatinine, uric acid, hydrogen ion and electrolytes.

In order to help clarify the effects of hyperthyroidism on renal function and electrolyte metabolism, we measured the venous plasma concentrations of urea, creatinine, urate, hydrogen ion and electrolytes, and the urinary concentrations of total protein, albumin, retinol-binding protein, N-acetyl-beta-D-glucosaminidase activity, and creatinine in patients when hyperthyroid and again after they had been euthyroid for at least 4 months. Significant (P less than 0.05) decreases in the mean plasma concentrations of urate and chloride and significant increases in creatinine, total CO2 and hydrogen ion mean concentrations were observed when the patients became euthyroid. The mean concentrations of sodium, potassium and urea did not change significantly. The values of the ratios total protein/creatinine, albumin/creatinine, N-acetylglucosaminidase/creatinine and retinol-binding protein/creatinine were all significantly (P less than 0.05) elevated in random urine specimens obtained from hyperthyroid patients as compared to the values when euthyroid. Mild proteinuria occurs in most thyrotoxic patients which does not appear to be due predominantly to either glomerular or tubular renal injury. The changes in plasma analytes that were observed may be attributed to increases in glomerular filtration rate and tissue nucleic acid turnover and a tendency to respiratory alkalosis in the hyperthyroid patients.

Acetylglucosaminidase↗
PubMed1989

Correlation between Doppler flow velocity waveforms and cord blood viscosity.

The contribution of rheological factors to the impedance of blood flow in the umbilical artery as determined by continuous-wave Doppler ultrasound was investigated. Of the 51 pregnancies recruited, six were complicated by pre-eclampsia, 10 by intrauterine growth retardation, 15 by both pre-eclampsia and fetal growth retardation, and there were 20 controls. A significant correlation was demonstrated between both plasma viscosity and gestational age and the resistance index used to characterize the Doppler waveform. Multiple regression analysis demonstrated that changes in plasma viscosity explained 55% of the variance seen in the resistance index and that this was statistically significant. This finding is, however, unlikely to be of clinical significance as whole blood viscosity had an insignificant effect on the impedance in the umbilical artery. We postulate that vascular factors such as the number and calibre of the placental arterioles are a more important determinant of umbilical artery impedance.

Blood Flow Velocity↗
PubMed1989

Whiplash injury: a reappraisal.

Few topics provoke so much controversy or heated opinion, based on so little fact as whiplash injuries. In emergency departments, orthopaedic, neurological and rheumatological clinics, and not least in the Courts, this common syndrome is shrouded in mystery and creates clinical insecurity in those who attempt to explain its mechanism, its prognosis and treatment. These problems are compounded in medico-legal practice where the potential rewards of successful litigation may colour the clinical picture.

Adult↗
PubMed1989

Clinical features of the exploding head syndrome.

Fifty patients suffering from the "exploding head syndrome" are described. This hitherto unreported syndrome is characterised by a sense of an explosive noise in the head usually in the twilight stage of sleep. The associated symptoms are varied, but the benign nature of the condition is emphasised and neither extensive investigation nor treatment are indicated.

Adult↗
PubMed1989

Prolonged rupture of the fetal membranes and neonatal outcome.

In order to establish the incidence of neonatal infection following prolonged (greater than 24 hours) rupture of the fetal membranes (PROM) and assess outcome of two year retrospective study was undertaken. The names of all babies born following PROM were obtained from the computerised obstetric record and the bacteriological results and outcome reviewed. Of 208 babies born following PROM only three had blood cultures containing pathogens--all of whom were of less than 1500 g birthweight and all of whom died. This represents a fivefold increased frequency of infection for premature babies but no increased risk for full term babies. The overall incidence of infection was much lower than in previous series and this may be due to performing amniocentesis as soon as possible following rupture and inducing labour where there was evidence of incipient chorioamnionitis. Meningitis was not associated with prolonged rupture of the membranes. The mortality for these babies was higher than those of babies without PROM in the 28-31 week gestation group. This was strongly associated with early onset of membrane rupture and none of the babies born following membrane rupture prior to 20 weeks gestation survived. Non-infective pulmonary disease was the main cause of increased mortality.

Bacterial Infections↗
PubMed1989

A role for stimulus generalization in conditional discrimination learning.

In each of three experiments on discrimination learning by rats, whether or not a 10-sec target stimulus was followed by food was determined by the nature of a 2-min background stimulus that accompanied it. A conditional discrimination was employed in Experiment 1 such that background A indicated food would follow one target but not the other, whereas this relationship between the targets and food was reversed in the presence of background B. Experiment 2 employed two feature-positive discriminations. Subsequent test trials revealed that the background for one discrimination was able to enhance responding during the target for the other discrimination. Experiment 3 employed a feature-positive and a feature-negative discrimination prior to test trials in which each target was presented separately during a compound of both background stimuli. The compound enhanced responding to the target from the feature-positive discrimination and reduced it to the target from the feature-negative discrimination. We suggest that to accommodate all these findings, the best explanation is provided by a configural model of Pavlovian conditioning.

Animals↗