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Biomedical subjects

B Morgan

Publications and source records attributed to B Morgan.

At least 91 records · Page 5Linked to original sources
PubMed1990

Hyperlipidaemia in general practice: three year follow up of an opportunistic screening project.

As part of the national lipid screening project 927 people with a plasma cholesterol level greater than 6.5 mM were detected by screening 4006 men and women aged 25-59 years. Three years later 801 of the 878 patients eligible for a follow-up study (91%) had been followed up at least once. The median number of follow-up visits was two. The bulk of the workload fell on the nursing staff. The mean decrease in cholesterol level was 8-14% in those receiving dietary advice only, 15-25% in those receiving additional drug treatment and 12% for all patients. A proportion of this decrease must be attributable to regression to the mean, loss to follow up when patients were doing well, and the patients' knowledge of their follow-up date. Data on a group of patients not attending for regular follow up suggest that regression to the mean could account for up to 7% of the cholesterol reduction observed. Screening for hyperlipidaemia in general practice is feasible when the necessary infrastructure is provided, but even with a fairly conservative protocol 3% of those screened received drug treatment.

Adult↗
PubMed1989

Screening for congenital dislocation of the hip by child-health nurses in Western Australia.

The child-health nurse screening programme for the presence of congenital dislocation of the hip in Western Australia was evaluated by the use of data that were collected as a routine from the Congenital Malformations Registry, the records of child-health nurses and the Hospital Morbidity System. The programme performed well operationally, with a sensitivity of 68.5%, a specificity of 98.8%, and a positive predictive value of 15.1%. Of the children who were born in the study period (1981-1983), 450 children were diagnosed with congenital dislocation of the hip, and 46 (10.2%) of these children required 104 hospital admissions for the treatment of their dislocation. Of the children whose hips were found to be dislocated in screening (those who were screened as "true-positive" cases), 10.1% were hospitalized, whereas 16.1% of those children who were missed by screening (who screened as "false negative") required hospitalization (95% confidence interval [CI] for the difference in proportions, -7.8% to 19.9%). A comparison of the measures of hospitalization was made between the children who were found to be "true positive" on screening and the children whose dislocation was diagnosed in the hospitals of their birth--a group that generally is considered to show the best outcome. A somewhat-higher proportion of children who were screened as "true positive" required an open surgical procedure (5.0% of children compared with 2.8% of children; 95% CI for the difference, -2.1% to 6.5%). The differences in the other measures of hospitalization between the two groups were small.

Child↗
PubMed1989

Expression of nerve growth factor receptors by human peripheral blood mononuclear cells.

In the rat, nerve growth factor (NGF) has been shown to affect immune reactivity by binding to cell surface receptors on a subpopulation of splenic mononuclear cells. This binding occurs in a specific and saturable fashion to what appear to be low-affinity (type II) NGF receptors (NGFR). Immunofluorescence studies here showed that NGFR are also present on a proportion of human peripheral blood mononuclear cells (PBMC). Equilibrium binding studies demonstrated that the binding of NGF to its receptors on PBMC occurs with a single equilibrium binding constant (mean) of 2.11 X 10(-9) M. The number of receptors per cell was determined to be approximately 6.94 X 10(3) receptors/cell. These results would suggest a role for NGF in the regulation of immune function in man, as well as in animals.

Cell Membrane↗
PubMed1989

Effect of protein malnutrition on the composition of submandibular glands of aged rats.

Fifty 22-month-old male Sprague-Dawley rats were fed for 8 weeks ad libitum with either a 20% protein diet (control) or a 5% protein diet (protein malnourished group). Submandibular glands were removed, weighed and homogenate prepared. After the low protein diet, there was a slight but significant decrease in body weight, glandular content of total protein (mg/g tissue), kallikrein activity/mg protein and glutamine-rich peptide. In contrast, the gland weight, DNA and mucin content were not changed by feeding a low protein diet. Thus in aged rats submandibular glands are only modestly affected by protein malnutrition and the effects on gland-specific proteins vary.

Aging↗
PubMed1989

Effect of time and adrenaline on the feto-maternal distribution of bupivacaine.

Following lumbar extradural analgesia with 0.5% bupivacaine, the placental transfer of bupivacaine was examined in 40 women undergoing elective and 40 women undergoing emergency Caesarean section. Within each group, the patients received randomly either plain bupivacaine or bupivacaine with adrenaline 1 in 200,000. Plasma bupivacaine concentrations were measured in blood samples taken simultaneously at delivery from the umbilical vein (UV), umbilical artery (UA) and maternal vein (MV). Bupivacaine concentrations in MV, UV and UA were not significantly affected by the presence of adrenaline, but were positively correlated with first dose to delivery interval (FDD) while MV and UV were inversely correlated with last dose to delivery interval (LDD). Mean ratio of UV:MV concentrations of bupivacaine was 0.346 and for UA:MV it was 0.305. There was no significant correlation between any fetal:maternal ratio and FDD or LDD. UA:UV ratio appeared to increase towards unity 30-40 min after the last dose. The presence of adrenaline was associated with an increase in UA:UV in the elective group (P less than 0.01). In eight patients who received adrenaline there was reverse placental transfer (UA:UV greater than 1). There was no evidence of progressive fetal accumulation of bupivacaine beyond 30-40 min.

Anesthesia, Epidural↗
PubMed1988

Blood lipid concentrations and other cardiovascular risk factors: distribution, prevalence, and detection in Britain.

To establish the distribution of blood lipid concentrations and the prevalences of other risk factors for cardiovascular disease in Britain 12,092 men and women aged 25-59 in Glasgow, Leicester, London, and Oxford were studied. Subjects were selected by opportunistic case finding, in which patients consulting their general practitioner for any reason were offered a health check by appointment, or random selection from age-sex registers, in which an invitation for a health check was posted. The overall rate of response was 73%, being 91-94% by opportunistic case finding and 36-63% by random selection. At the health check subjects answered a brief questionnaire about risk factors for cardiovascular disease, and their height, weight, and blood pressure were recorded; a blood sample was taken for measuring plasma concentrations of cholesterol, triglyceride, high density lipoprotein cholesterol, and glucose. The mean cholesterol concentrations were 5.9 (SD 1.2) and 5.8 (1.2) mmol/l in men and women, respectively. In London the mean value was 5.5 (1.2) mmol/l for both men and women and was significantly lower than mean values in the three other centres, among which there were no significant differences. In men and women aged 25-29 concentrations were similar but they increased in men until the age of 45-49, after which they showed no further increase; in women concentrations did not increase until the age of 40-44 and by the age of 50-59 values were higher than in men. Mean triglyceride concentrations were significantly higher in men than in women (1.8 (1.4) v 1.3 (0.9) mmol/l, respectively), and trends with age were similar to those for cholesterol concentrations, except that at no age were values higher in women than in men. Mean triglyceride values overall were higher in Glasgow and London than in Oxford and Leicester. Body mass index was higher in Glasgow and London than in the other two centres and correlated with systolic and diastolic blood pressures and triglyceride concentration. In addition, subjects in Glasgow smoked significantly more than those in the other centres. These observations could contribute to the higher rate of coronary heart disease in Glasgow. Plasma lipid concentrations and the prevalences of other risk factors for cardiovascular disease were similar in subjects selected by opportunistic case finding and by random selection. In Britain cholesterol values have changed little during the past 12 years despite dietary recommendations and health education.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1988

Nerve growth factor binding in aged rat central nervous system: effect of acetyl-L-carnitine.

The nerve growth factor protein (NGF) has been demonstrated to affect neuronal development and maintenance of the differentiated state in certain neurons of the peripheral and central nervous system (CNS) of mammals. In the CNS, NGF has sparing effects on cholinergic neurons of the rodent basal forebrain (BF) following lesions where it selectively induces choline acetyltransferase (ChAT). NGF also induces ChAT in the areas to which BF provides afferents. In aged rats, there is a reduction in the NGF-binding capacity of sympathetic ganglia. Here, we wish to report that there is a decrease in the NGF-binding capacity of the hippocampus and basal forebrain of aged (26-month-old) rats as compared to 4-month-old controls but no change in NGF binding in cerebellum. In all instances, equilibrium binding dissociation constants did not differ significantly. Treatment of rats with acetyl-L-carnitine, reported to improve cognitive performance of aged rats, ameliorates these age-related deficits.

Acetylcarnitine↗
PubMed1988

Deep tectal cells in pigeons respond to kinematograms.

Deep tectal neurons in pigeons respond selectively to moving visual stimuli, and are inhibited by large background patterns moved in-phase with these stimuli. In this investigation we demonstrate that these same deep tectal neurons respond equally well to kinematograms as they do to traditional luminance contrast stimuli typically employed in visual experiments. Computer generated kinematograms, the motion domain equivalents of random dot stereograms, were used as stimuli in these experiments. These kinematograms, where a small centrally located set of random dots is moved coherently in one direction while the remaining dots are moved in a different direction, thus constitute a pure motion stimulus where the stimulus form is only visible in the dynamic pattern, but does not exist on any single frame. Both 'object' configured and 'hole' configured kinematograms were employed; the former appearing as regions of texture moving over, or in front of, the background texture, while the latter appear as windows through which a more distant textured surface is revealed. Extracellular recordings from isolated deep tectal cells showed that all units responded in a very similar manner whether the stimulus was an 'object' configured kinematogram or the more traditional luminance contrast variety. This similarity included directional selectivity, the in-phase inhibition anti-phase facilitation effect, and sensitivity to opposed motion independent of direction. However, when the kinematograms were configured as 'holes' none of the units tested responded to these stimuli. The significance of these observations for tectal functioning, image segmentation through motion and animal camouflage is discussed.

Animals↗
PubMed1988

Delta-9-tetrahydrocannabinol during pregnancy in the rat: effects on development of RNA, DNA, and protein in offspring brain.

Either 15 or 50 mg/kg of delta-9-tetrahydrocannabinol (THC) was administered from Day 2 through Day 22 of gestation. Pair-fed and nontreated groups served as controls and all treated and control litters were fostered at birth to untreated dams. To determine the effects of THC on offspring brain development, DNA, RNA and protein values were determined at 7, 14, and 21 days of postnatal age. DNA and RNA levels appeared unaffected by THC but brain protein levels of the 50 mg/kg offspring were significantly lower than in the other groups at Day 7 and 14. This suggests that the high THC dose inhibited protein synthesis for at least the first 14 days of life. Subsequently, protein levels of the 50 mg/kg offspring increased rapidly so that there were no differences between any of the groups at 21 days of age. These findings for developing CNS parallel the delayed rate of somatic growth previously reported from our laboratory and suggest a transitory rather than a permanent effect of THC on both somatic and brain growth. We also found that THC produces a significant dose-related increase in the sex-ratio of live male-to-female offspring, a finding we have reported previously.

Animals↗
PubMed1988

H2 antagonists and bupivacaine clearance.

The effect of the H2 receptor antagonists cimetidine and ranitidine on bupivacaine clearance was assessed in women scheduled to undergo elective Caesarean section under epidural anaesthesia. Thirty-six women were randomly allocated to receive either no medication, cimetidine 400 mg or ranitidine 150 mg on the night prior to and on the morning of surgery. No significant difference was found between the peak bupivacaine levels: the mean (SD) values were 0.74 (0.17) microgram/ml, 0.81 (0.38) microgram/ml and 0.70 (0.24) microgram/ml in the control, cimetidine and ranitidine groups, respectively. Similarly, the H2 receptor antagonists did not alter the plasma bupivacaine against time curves, half-life or bupivacaine clearance in the three groups studied.

Adult↗
PubMed1987

Production and characterisation of a human monoclonal antibody to cytomegalovirus and its use in an early nuclear fluorescence assay.

A human monoclonal antibody to cytomegalovirus (CMV) was produced by transforming peripheral blood mononuclear cells of a patient with recent CMV infection. It is directed against a late antigen located in the nucleus of CMV infected fibroblasts at 24-72 hours postinfection and immuneprecipitates 65K and 48K proteins from 35S-labelled CMV infected cells. Results of its use in an early nuclear fluorescence assay for rapid diagnosis are presented.

Adult↗
PubMed1987

Effects of pre-weaning undernutrition on 21 day-old male rat skull form as described by the finite element method.

Conventional Roentgenographic Cephalometric Methods (RCM) have certain conceptual and geometric constraints that ensure that their descriptions of cephalic growth and comparisons of cephalic form are reference-frame-dependent; and it is impossible to determine which, if any, RCM reference frame provides a biologically more correct description or comparison. The use of the concepts of continuum mechanics and of the numerical techniques of the Finite Element Method (FEM) overcomes these constraints and provides reference-frame-independent (invariant) growth descriptions and form comparisons. In the FEM, the structure of the head is subdivided (discretized) into a number of smaller, finite, elements. The FEM then describes the growth behavior, or compares the form, of the entire continuum of points enclosed with each element independently; in RCM only the behaviors, or comparisons, of the landmark points are described. The FEM is described and its use illustrated by a comparison of the cephalic forms of 4 groups of weanling (21 d old) rats. The 1st (control) group is derived from normally nourished dams, while the other 3 groups are derived from dams who were malnourished throughout the weaning period in 3 group specific manners. The FEM permitted reference-frame-independent comparisons of the 4 different, and group specific, head forms. These differences were reflected in the forms of each of the finite elements. The differences in element forms between the 4 groups were shown to be related primarily to nutritionally produced alterations of either neurocranial or splanchocranial viscera. These differences were expressed in the alterations of the forms of the continua enclosed within the boundaries of the several finite elements, and secondarily in the form of the cranial skeleton.

Animals↗
PubMed1987

Colectomy and ileostomy in the management of ulcerative colitis.

For 30 years, colectomy with ileostomy has been the mainstay of the surgical treatment for ulcerative colitis. Between 1963 and 1985, 535 patients with inflammatory bowel disease were admitted to the Royal Prince Alfred Hospital in Sydney, Australia; 471 had ulcerative colitis and 64 Crohn's colitis. One hundred and eight-six of these patients underwent colonic resection. The proportion of patients who underwent surgery was the same for both disorders. There have been no deaths resulting from the surgical management of inflammatory bowel disease at our hospital since 1965. These patients should be treated safely by standard means before the more elaborate sphincter-saving procedures, currently recommended, are tried.

Colectomy↗