Search PubMed⌕ Search

Biomedical subjects

J Rhodes

Publications and source records attributed to J Rhodes.

At least 109 records · Page 6Linked to original sources
PubMed1993

Effect of hemodialysis on left ventricular contractility in pediatric patients with end-stage renal disease.

Assessment of the effect of hemodialysis on myocardial contractility is complicated by variations in loading conditions that can occur during hemodialysis and by the prevalence of coronary artery disease among patients with chronic renal failure. Therefore, we used a load-independent index of left ventricular contractility, derived from analyses of the rate corrected velocity of circumferential fiber shortening (Vcfc)-end systolic wall stress (ESWS) relationship, to study the acute effects of hemodialysis on left ventricular function in the cases of 15 pediatric patients with end-stage renal disease. Prior to dialysis, Vcfc was appropriate for ESWS (102% +/- 16% of predicted) and did not differ significantly from values obtained from a group of nine normal control subjects of similar ages (103% +/- 9% of predicted), indicating that the patients' left ventricles were functioning in a normal inotropic state. After dialysis, Vcfc increased to levels beyond those expected for ESWS (118% +/- 20% of predicted, P < .05 versus control; P < .001 versus predialysis levels), indicating that dialysis was associated with enhancement of the left ventricle's inotropic state. A statistically significant increase in plasma norepinephrine levels was also observed. However, the increase in the percentage of the predicted Vcfc did not correlate with observed changes in this inotropic agent or with dialysis-induced variations in body weight or levels of electrolytes, urea nitrogen, or creatinine, and firm conclusions regarding the identity of the factors responsible for the positive inotropic effect of hemodialysis could not be drawn.

Adolescent↗
PubMed1993

Hormone replacement therapy prevents bone loss in patients with inflammatory bowel disease.

Patients with inflammatory bowel disease have an increased prevalence of osteoporosis, and suffer high rates of spinal bone loss. Hormone replacement therapy (HRT) is effective in the treatment and prevention of osteoporosis but has not been studied in patients with inflammatory bowel disease. A two year prospective study of HRT in inflammatory bowel disease was performed in 47 postmenopausal women aged 44 to 67 years with ulcerative colitis (25) or Crohn's disease (22). Patients had radial and spinal bone density measured annually by single photon absorptiometry and quantitative computed tomography respectively. The mean (95% confidence intervals) annual change in radial bone density was +1.42%/yr (+0.58 to +2.26; P < 0.005) and for spinal bone +2.60%/yr (+1.06 to +4.15; p < 0.005). There was no significant correlation between rates of change of bone density at the two sites, or between the rates of change and the initial bone density either in the radius or spine. Twelve patients were given prednisolone during the study, and their rates of change for spinal bone density were lower, but values were not statistically significantly different from those who did not receive corticosteroids. Changes in bone density for patients with ulcerative colitis and Crohn's disease were not significantly different. The change in bone density did not correlate with the patients' age or number of years after the menopause. It is concluded that HRT is effective in prevention of bone loss in postmenopausal women with inflammatory bowel disease.

Adult↗
PubMed1993

Hormone replacement therapy in chronic active hepatitis; a case report.

There is an increased incidence of osteoporosis in patients with chronic liver disease. Because patients with chronic active hepatitis (CAH) usually require corticosteroids for their liver disease prevention and treatment of bone loss presents a difficult problem. This case report describes a 41 year old female patient with CAH who had a high rate of bone loss. After an early menopause with noticeable menopausal symptoms, she was given transdermal oestrogen replacement therapy. The menopausal symptoms resolved completely, and there was no deterioration in her liver function tests or corticosteroid requirement. In addition, follow up quantitative bone mineral measurements over two years have shown improvement. This case shows the value of measurements of bone density, and oestrogen replacement therapy in CAH, even in the presence of continued corticosteroids.

Adult↗
PubMed1993

Comparison of bismuth citrate and 5-aminosalicylic acid enemas in distal ulcerative colitis: a controlled trial.

An enema that contained a complex of bismuth citrate and polyacrylate was compared with 5-aminosalicylic acid (5-ASA) enemas for treatment of distal ulcerative colitis. The multicentre trial involving 63 patients was randomised and double blind with enemas given over four weeks; clinical, sigmoidoscopic, and histological assessments were made. Improvements were seen in both treatment groups. Clinical remission was seen in 18 of 32 patients treated with 5-ASA and 12 of 31 patients treated with bismuth citrate-carbomer (chi 2 1.94; p = 0.16). Sigmoidoscopic remission occurred in 20 of 32 patients in the 5-ASA group and 15 of 31 patients given bismuth (chi 2 1.27; p = 0.26). Improvement of rectal biopsy histology by at least one grade was seen in 16 of 32 patients in the 5-ASA group and 14 of 31 patients with bismuth (chi 2 0.15; p = 0.70). Analysis of covariance gave no significant difference between groups, although there was a trend favouring 5-ASA. There was no evidence of bismuth accumulation during the trial. Bismuth enemas may offer a new therapeutic option in distal ulcerative colitis.

Adult↗
PubMed1993

Ventilatory work and oxygen consumption during exercise and hyperventilation.

The work of breathing (WB), and thus the energy requirement of the respiratory muscles, is increased any time minute ventilation (VE) is elevated, by either exercise or voluntary hyperventilation. Respiratory muscle O2 consumption (VRMO2) in humans has generally been estimated by having subjects breathe at a level comparable to that during exercise while the change in O2 consumption (VO2) is measured. The difference between VO2 at rest and during hyperventilation is attributed to the respiratory muscles and is assumed to be similar to VRMO2 during exercise at the same VE. However, it has been suggested that WB differs between exercise and hyperventilation and that WB during exercise is lower than during hyperventilation at the same VE. In this study we measured WB during exercise and hyperventilation and from these measurements estimated VRMO2. WB, VE, and VO2 were measured in five male subjects during rest and during exercise or hyperventilation at levels of VE ranging from 30 to 130 l/min. VE/WB relationship was determined for both hyperventilation and exercise. Multiple regression analysis showed that the shape of the two curves was different (P < 0.0001), with WB at high levels of VE being < or = 25% higher in hyperventilation than in exercise. In a second study in which frequency, tidal volume, and duty cycle were controlled as well as VE, there was no difference in WB between exercise and hyperventilation. VO2 was significantly correlated with WB, and the estimated VRMO2 did not increase as a fraction of total VO2 as exercise intensity rose.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

A new noninvasive method for the estimation of peak dP/dt.

BACKGROUND: Peak dP/dt is a good index of ventricular performance that is not influenced by afterload, wall motion abnormalities, or the variations in ventricular anatomy and morphology commonly encountered among patients with congenital heart disease. Unfortunately, the clinical utility of peak dP/dt has been limited by the fact that its measurement generally requires an intraventricular catheter. However, peak dP/dt occurs during isovolumetric contraction, and the pressure rise during isovolumetric contraction is almost linear. Therefore, the mean dP/dt during isovolumetric contraction (mean dP/dtic), ie, the ratio of the rise in pressure during isovolumetric contraction (aortic diastolic pressure minus the systemic ventricular end-diastolic pressure [VEDP]) over the isovolumetric contraction time, should provide a good estimate of peak dP/dt that could be generated noninvasively. METHODS AND RESULTS: Echo/phonocardiography was used to measure the isovolumetric contraction time and a blood pressure cuff to estimate aortic diastolic pressure of 27 patients (age, 1 day to 77 years) with congenital or acquired heart disease. VEDP was determined by three methods: (1) intraventricular catheter, (2) assumed VEDP of 10 mm Hg, and (3) assignment of a normal or elevated value on the basis of clinical history. The three estimates of mean dP/dtic thus generated were compared with simultaneous measurements of peak dP/dt obtained during cardiac catheterization. Invasively measured peak dP/dt correlated well with the indirect determinations (r = .95, .89, and .92 for methods 1, 2, and 3, respectively; P < .0001). CONCLUSIONS: Echo/phonocardiography can be used in conjunction with a blood pressure cuff and indirect estimates of VEDP to generate mean dP/dtic, an index of ventricular function that approximates and closely correlates with peak dP/dt. This noninvasive measurement can be obtained in almost any patient and may be useful in the assessment of ventricular performance in a variety of cardiovascular disorders.

Adolescent↗
PubMed1992

Galactose oxidation in the design of immunogenic vaccines.

Potent immunological adjuvants are urgently required to complement recombinant and synthetic vaccines. However, it has not been possible to derive new principles for the design of vaccine adjuvants from knowledge of the mechanism of immunogenicity. Carbonyl-amino condensations, which are essential to the inductive interaction between antigen-presenting cells and T helper cells, were tested as a target for the enhancement of immune responses. Enzymic oxidation of cell-surface galactose to increase aminereactive carbonyl groups on murine lymphocytes and antigen-presenting cells provided a potent, noninflammatory method of enhancing the immunogenicity of viral, bacterial, and protozoal subunit vaccines in mice.

Adjuvants, Immunologic↗
PubMed1992

A pharmacokinetic study of sulphasalazine and two new formulations of mesalazine.

We have examined the pharmacokinetics of enteric coated sulphasalazine compared with two new formulations of mesalazine. These consisted of microgranules of mesalazine coated with Eudragit S in a concentration of either 20 or 25% dry lacquer substance; these in turn were enclosed in capsules coated with Eudragit L. In-vitro dissolution studies of coated microgranules showed that drug release was pH dependent. Studies in 7 normal volunteers showed median peak concentrations of 5-amino-salicylic acid and N-acetyl-5-amino-salicylic acid occurred at about 6 hours with both microgranular preparations, compared with sulphasalazine at 15 h. The microgranule formulation coated with 20% Eudragit S gave serum levels and overall systemic absorption similar to values with sulphasalazine. This new formulation may be of value for delivering mesalazine and other therapeutic agents to the colon.

Adult↗
PubMed1992

A comparison of upper gastrointestinal mucosal damage by standard and delayed-release indomethacin.

Forty-five patients taking long-term indomethacin and with endoscopic erosions or superficial ulcers in the oesophagus, stomach or duodenal bulb were randomized in a double-blind study to continue with standard indomethacin or receive a 'delayed-release' formulation. This consisted of microgranules of indomethacin coated with an acrylic resin, Eudragit L, which releases drug in the small intestine. Endoscopy was repeated after 8 weeks and biopsies taken on both occasions. Changes in endoscopic lesions and histological appearances were similar in both groups, although mucosal erythema was less in those given Eudragit L indomethacin. Systemic, rather than topical, effects of indomethacin may therefore be responsible for persistence of gastro-duodenal mucosal lesions in these patients. There is reason to question the clinical practice of using expensive, delayed-release preparations.

Adult↗
PubMed1992

Smoking habits in psoriasis: a case control study.

We have examined smoking habits in 108 patients with psoriasis, including some with palmoplantar distribution, and compared the results with matched controls from the community. There was a significant association between psoriasis, current smoking status (OR = 2.7, 95% CI 1.44-5.42, P less than 0.01) and smoking habits prior to the onset of disease (OR = 3.75, 95% CI 1.68-9.47, P less than 0.001). There was also a marked dose-response relationship; the relative risk of psoriasis in those currently smoking more than 20 cigarettes/day was significantly elevated (OR = 5.3, 95% CI 2.1-13.0, P less than 0.001). Separate analysis of patients without palmoplantar distribution of psoriasis showed a significant association with smoking prior to onset of psoriasis (OR = 3.6, 95% CI 1.5-9.8, P less than 0.001). Smoking may play a role in the aetiology of this common skin disorder.

Adolescent↗
PubMed1992

Incidence of ulcerative colitis in Cardiff over 20 years: 1968-87.

The annual incidence of ulcerative colitis in the city of Cardiff was examined over a 20 year period. In the decade 1968-77, the mean annual incidence was 6.4 per 10(5) of the population compared with 6.3 for the period 1978-87. There was no difference in the distribution or extent of the disease between decades or between sexes. This contrasts with the increased incidence of Crohn's disease during the same period. The study included a survey of family practitioners which identified a further 19 patients (11% of the total).

Adolescent↗
PubMed1992

Perceived discrimination in education and employment by people with Crohn's disease: a case control study of educational achievement and employment.

Eighty three patients in whom the diagnosis of Crohn's disease had been made before the age of 40 years and who had been resident in the city of Cardiff were asked to complete a detailed questionnaire about their educational and employment experiences. Responses were obtained from 58 patients (response rate = 70%), 23 buddy controls, and 27 community controls. The mean (SD) age of patients at the time of the survey was 31 (5) years. Twenty four of the patients were diagnosed before leaving secondary education, at a mean age of 17 years. They had lost significantly more days' schooling than controls (chi 2 = 14.3 p less than 0.001) but had achieved similar academic success as measured by examination passes and attendance at tertiary institutes of education. Similar numbers of patients and controls were employed at the time of the survey, although significantly more patients had experienced long term unemployment (z = 2.6 p less than 0.01). As a result of their experiences up to 30% actively concealed their illness from employers.

Adult↗
PubMed1992

Sexual dysfunction amongst women with Crohn's disease: a hidden problem.

The sexual problems of 50 women with Crohn's disease, of whom 45 had a stable relationship, were investigated by structured interview and compared with age-matched controls. Twenty-four percent patients had either infrequent or no intercourse compared with 4% of controls (chi 2 = 8.3, p < 0.005). However, amongst patients and controls who were sexually active, the frequency of intercourse was similar. Reasons for sexual inactivity included abdominal pain (24%), diarrhoea (20%) and fear of faecal incontinence (14%). Dyspareunia was common in patients (chi 2 = 6.5, p < 0.01) and this was irrespective of the site of disease (large vs. small bowel chi 2 = 0.85, NS). Women with perianal disease and fistulae were more likely to have dyspareunia than women with neither (chi 2 = 4.2, p < 0.05), although this was not so for less extensive involvement with only perianal disease (chi 2 = 2.8, NS) or fistulae (chi 2 = 0.8, NS). Vaginal candidiasis was more common in patients (chi 2 = 5.8, p < 0.02), and on occasions this may have contributed to dyspareunia. Women with Crohn's disease experience sexual problems much more than healthy controls and they need support, sympathetic investigation and management.

Adult↗
PubMed1992

Risk of ulceration with long-term indomethacin: endoscopic and histological changes in upper gastro-intestinal mucosa.

Twenty patients taking long-term indomethacin were chosen for the study because all had a normal endoscopic examination; biopsies, however, from the oesophagus, gastric antrum and duodenal bulb revealed histological inflammation in all patients in at least one site. After 8 weeks during which indomethacin therapy was continued, a further endoscopy revealed lesions in 5 patients--peptic ulcer in 3 and erosions in 2--but only 1 of these had any change in gastro-intestinal symptoms. Irrespective of whether mucosal lesions are seen on endoscopy in patients established on non-steroidal anti-inflammatory drug therapy, they remain in danger of developing both ulcers and erosions which are likely to be asymptomatic. At no time can one justifiably feel this patient group is not at risk of peptic ulceration.

Arthritis, Rheumatoid↗