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Biomedical subjects

C Evans

Publications and source records attributed to C Evans.

At least 199 records · Page 11Linked to original sources
PubMed1988

Visual acuity testing of young children with the Cambridge Crowding Cards at 3 and 6 m.

A modification of the single optotype Sheridan Gardiner test for pre-school children has been used to measure visual crowding. A significant 'crowding effect' has been found in children between the ages of 3 and 6 years with a general decrease in the effect over the pre-school years. The 'crowding' in 5-7 year olds is not significantly greater than that found in adults. No significant difference has been found in the extent of crowding using the test at 3 m rather than the normal 6 m viewing distance, although in general the test has been found to be practically easier with better co-operation at 3 m for the younger children. For these reasons, this particular test at 3 m would seem to be well suited to acuity testing in pre-school children, when an acuity equivalent to Snellen values is required.

Adult↗
PubMed1988

The total score of the Crown-Crisp Experiential Index: a useful and valid measure of psychoneurotic pathology.

The Crown-Crisp Experiential Index (CCEI) was designed as a measure of neurotic symptomatology. The tendency has been to report upon its six separate scales and to ignore the total score. We report on the use of the CCEI in a detailed interview study of 208 40-49-year-old women from a local community and 40 patients of the same age range and sex from a psychiatric hospital. In this study, scores on the six scales of the CCEI were shown to be highly intercorrelated. A case is made for combining the six scale scores to form an overall score of neurotic pathology. This score was validated against a number of variables. It was shown to be significantly related to psychiatric patient status, negative self-evaluation, level of severity of current symptoms, evidence of previous psychiatric episodes, previous psychiatric treatment and psychiatric symptoms in childhood. These validation variables were themselves intercorrelated but severity of current symptoms, self-evaluation and childhood symptoms had significant independent effects. It is concluded that scores on the six scales of the CCEI may be less important than the total score which provides a useful and valid measure of psychoneurotic pathology and has particular application as a screening instrument in community surveys.

Adult↗
PubMed1988

Spinal trabecular bone mineral content in patients with non-steroid treated rheumatoid arthritis.

Spinal trabecular bone mineral content was measured in the first, second, and third lumbar vertebrae by quantitative computed tomography in 88 patients with non-steroid treated rheumatoid arthritis. Results were compared with those obtained in 105 healthy control subjects. The mean bone mineral content in the patient group, 135.8 (SD 32.8) mg/ml K2HOP4, was significantly lower than that in the controls (151.9 (32.1) mg/ml, p less than 0.01). Division of patients and controls into three age groups showed that the reduction in bone mineral content was most marked in the youngest age group (21-40 years), the mean value in male patients being significantly lower than in controls (149.6 (51.3) v 171.7 (23.9) mg/ml K2HPO4, p less than 0.05); in female patients in this age group the corresponding values were 160 (26.1) v 178.4 (22.0) mg/ml, 0.05 less than p less than 0.1). No significant difference in mean values between patients and controls was found in the other age groups. Of the 88 patients, six (7%) had abnormally low values, defined as a bone mineral content greater than 2 SD below the normal mean. One vertebral crush fracture was found in one patient but not in any of the controls. No correlation was found between bone mineral content and body weight, duration of disease, or disability as assessed by the London and Steinbroker methods. These results demonstrate a lower spinal trabecular bone mineral content in non-steroid treated patients with rheumatoid arthritis than in age and sex matched controls, the difference being most marked in younger patients. The finding of abnormally low values in 7% of the patients indicates a slightly increased prevalence of spinal osteoporosis in these patients.

Adult↗
PubMed1988

Increased rate of spinal trabecular bone loss in patients with inflammatory bowel disease.

The rate of spinal trabecular bone loss during one year was measured in 54 patients with inflammatory bowel disease. The mean change in spinal bone mineral content was -5.1 mg/ml K2HPO4, representing 3% of the initial bone mineral content. The rate of bone loss showed a significant negative correlation with body mass index (r = -0.276, p less than 0.05) but no other significant correlations were found with other clinical or biochemical indices, including the total amount of prednisolone taken during the course of the study. Eleven patients had bone loss greater than 15 mg/ml/year; these included four non-steroid treated patients, two of whom had disease confined to the large bowel. The results indicate rapid rates of bone loss in some patients with inflammatory bowel disease over the course of one year. Although steroid therapy and malnutrition are likely to be contributory factors in some patients, other, as yet unidentified, risk factors also operate. The rapid bone loss observed in some patients emphasises the need for effective prophylactic regimes.

Adult↗
PubMed1988

Naloxone potentiates epinephrine release during hypoxia in fetal sheep: dose response and cardiovascular effects.

The effect of opiate receptor blockade on the plasma catecholamine response to hypoxemia was studied in seven chronically catheterized fetal lambs in utero. All animals underwent treatment with hypoxia alone, naloxone infusion alone (2 mg/kg) and hypoxia with naloxone at four different dosages (0.1, 0.5, 1.0, and 2.0 mg/kg). Maternal and fetal hypoxia was maintained for 20 min. There were no differences noted in the degree of hypoxemia or acidemia between the different hypoxia treatment groups. Hypoxia increased both norepinephrine and epinephrine plasma levels in all fetal sheep studied. We found a dose-dependent increase in plasma epinephrine levels in response to naloxone infusion during hypoxia. Plasma epinephrine level by 20 min of hypoxia with the 0.1 mg/kg naloxone dose (geometric mean 5366 pg/ml) was significantly more than with hypoxia alone (997 pg/ml). Naloxone at the other doses did not alter the epinephrine responses. There was no augmentation of plasma norepinephrine levels by naloxone at any dose studied. Thus, naloxone augmented the plasma epinephrine response to hypoxia in fetal sheep suggesting that the opiate peptides act as modulators of the sympathoadrenal system. The naloxone dose response differences observed in this study suggest this modulation is largely by antagonism of mu-receptors.

Animals↗
PubMed1988

Bone mineral content in normal UK subjects.

Bone mineral content in the lumbar vertebrae and in the shaft of the left radius has been measured in 129 normal British subjects using quantitative computed tomography and single-photon absorptiometry. Significant negative correlations between bone mineral content and age were found at both sites in males and females (p less than 0.001 in all cases). When expressed in g/cm the bone mineral content in the radial shaft showed significant positive correlations with body height and weight in both sexes, but after correction for bone size only a weak correlation with body height in males was found. Spinal trabecular bone mineral content showed no significant correlations with body height or weight in either sex. Comparison of the values obtained with normal data from centres in the USA revealed lower mean values for both radial and spinal bone mineral content in the British subjects. These differences emphasize the importance of using locally derived normal data for comparison with values obtained from patients.

Adolescent↗
PubMed1987

Factors related to sexual functioning in male patients undergoing hemodialysis and with kidney transplants.

The sexual functioning of 13 male patients undergoing renal dialysis and 13 male patients who had received kidney transplants was compared. Standardized interviews were used to assess the frequency of intercourse before illness, during dialysis, and after transplantation and to assess sexual difficulties experienced during these periods. In addition, plethysmographic recordings of erection levels were obtained for three dialysis and three transplant patients at eight separate time periods corresponding to particular points in the dialysis cycle. Assessments of depression and anxiety (IDA scale) and renal functioning (Marital Patterns Test) were also carried out. Dialysis patients were less able to gain and maintain erections than transplant patients and intercourse was less frequent for couples where the husband was on dialysis. Dialysis patients were more depressed than transplant patients, although transplant patients showed greater levels of anxiety. More marital difficulties were experienced by patients on dialysis than patients who had received transplants. The implications of these findings for the treatment of sexual problems in these patients are discussed.

Adult↗
PubMed1987

Percutaneous transluminal angioplasty of renal transplant artery stenosis.

Renal transplant artery stenosis occurs in approximately 10% of renal transplants, and antihypertensive drugs, vascular reconstructive surgery, and percutaneous transluminal angioplasty may be used in its treatment. Details of 28 cases of renal transplant artery stenosis were collected from a postal survey of United Kingdom transplant centres. The success rate for angioplasty (63% clinical cure or improvement) is lower than in previous reports.

Angioplasty, Balloon↗
PubMed1987

Sexual dysfunction after prostatectomy.

One of the major and disconcerting complications of prostatectomy is impotence. Several studies have reported only a small reduction in potency rates following prostatectomy but have not examined the effect of surgery per se on a group of men in whom one could expect a significant incidence of reduced potency. In order to rectify this defect, a prospective study was undertaken to assess the effect of transurethral resection of the prostate (TURP) and other general surgical procedures on two age-matched populations. In all cases potency and ejaculatory function and frequency of intercourse were assessed pre- and post-operatively. Potency was retained in 86% of men undergoing TURP and in all of the men undergoing general surgical procedures (p less than 0.01). Of those men who indicated that they were capable of having sexual intercourse prior to operation, 88% were unaffected by TURP. In the general surgical group 97% were unaffected. Thus it would appear that TURP has a significant effect on sexual function which cannot be accounted for by the stress of surgery or the age of the population undergoing operation.

Aged↗
PubMed1987

Peptide E and its products, BAM 18 and Leu-enkephalin, in bovine adrenal medulla and cultured chromaffin cells: release in response to stimulation.

Peptide E is a 25 amino acid opioid peptide which, if cleaved at the sole double basic (Lys-Arg) typical processing site, would generate two opioid fragments, the amino-terminal fragment BAM 18 and the carboxy-terminal fragment Leu-enkephalin. We have analysed extracts of bovine adrenal medulla in order to quantify these three opioid peptides (peptide E, BAM 18, and Leu-enkephalin). Here we present evidence that BAM 18 and Leu-enkephalin were present in similar amounts, whereas peptide E was present at a higher concentration. This is consistent with previous observations showing a preferential accumulation of larger peptides in the bovine adrenal, and also with the Lys-Arg bond being the principal site of cleavage of peptide E. However, when bovine adrenal chromaffin cells were maintained in culture for several days, Leu-enkephalin was found to be present in much greater amounts than was BAM 18-like immunoreactivity. The molar amounts of peptide E still exceeded the estimated levels of BAM 18 and Leu-enkephalin. We provide evidence that under conditions of basal release BAM 18 and peptide E were released, whereas Leu-enkephalin was released in much smaller amounts, if at all. On stimulation with nicotine results were consistent with an increased release of all three peptides with a preferential stimulation of Leu-enkephalin release. Under all conditions, the molar amounts of peptide E released apparently exceeded that of the other peptides. The results are discussed in terms of the regulation of partial proteolysis and the fate of peptide E.

Adrenal Medulla↗
PubMed1987

Cloning and expression in Escherichia coli of the gene encoding the heat-modifiable major outer membrane protein of Haemophilus influenzae type b.

One major outer membrane protein (P1) of Haemophilus influenzae type b (Hib), with an apparent molecular weight of 34,000 (34K) as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), has been shown to be heat modifiable. After heating at 100 degrees C for 5 min in 2% SDS, the P1 protein exhibits an apparent molecular weight of 49,000 (49K) in SDS-PAGE. Monoclonal antibodies (MAbs) reactive with P1 bound to the surface of Hib, and one of these MAbs had a protective effect against the development of Hib bacteremia in an animal model for invasive Hib disease. A 6-kilobase Hib DNA insert containing the gene encoding this P1 protein was cloned into Escherichia coli by using the gamma gt11 expression vector. Recombinant phage expressing P1 were identified by screening phage plaques with a MAb directed against the P1 protein. Expression of the P1 protein by an E. coli lysogen carrying the recombinant phage was independent of both vegetative phage growth and induction of lacZ gene-directed transcription of the Hib DNA insert. The Hib DNA insert encoding the P1 protein was subcloned into the plasmid vector pBR322, and a transformant containing the recombinant plasmid pFRG100 was identified with the P1 protein-directed MAb in a colony blot-radioimmunoassay. Western blot (immunoblot) analysis determined that the recombinant P1 protein possessed heat-modifiability characteristics identical to those of the native Hib protein. The P1 protein was expressed on the surface of both the E. coli lysogen containing the recombinant phage and the E. coli transformant containing pFRG100. Western blot analysis of acute- and convalescent-phase sera from infants with Hib meningitis showed that antibodies in the convalescent-phase sera recognized the P1 protein expressed by the E. coli transformant containing pFRG100. The availability of this cloned Hib DNA insert encoding the Hib P1 protein and the expression of this protein on the surface of recombinant E. coli should facilitate the investigation of P1 for both its vaccinogenic potential and its functional role in the outer membrane of Hib.

Antibodies, Monoclonal↗
PubMed1987

Osteoporosis in patients with inflammatory bowel disease.

Bone mineral content in spinal trabecular and peripheral cortical bone was measured in 75 unselected patients with small and/or large intestinal inflammatory bowel disease. Osteoporosis, defined as a bone mineral content greater than 2 SD below the age and sex matched normal mean value was present in 23 patients (30.6%). Three amenorrhoeic females aged 34, 38, and 42 years had severe clinical osteoporosis and a further three patients had one or more vertebral crush fractures. Eighteen of the 23 patients with osteoporosis had small intestinal disease with one or more resections and the mean lifetime steroid dose in those with osteoporosis was significantly higher than in those with normal bone mineral content. Bone mineral content in spinal trabecular bone showed significant negative correlations with lifetime steroid dose and serum alkaline phosphatase and a significant positive correlation with serum albumin. Peripheral cortical bone mineral content was positively correlated with body weight, height and body mass index. We conclude that the prevalence of osteoporosis is increased in patients with inflammatory bowel disease, severe clinical osteoporosis developing in some relatively young patients. The pathogenesis of this bone loss is probably multifactorial; steroid therapy is likely to be an important contributory factor.

Adult↗