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Biomedical subjects

R Persad

Publications and source records attributed to R Persad.

43 records · Page 3Linked to original sources
PubMed1994

Low activity of dapsone N-hydroxylation as a susceptibility risk factor in aggressive bladder cancer.

N-arylamines involved in the pathogenesis of bladder cancer, require metabolic activation via N-hydroxylation. The efficiency of in vivo N-hydroxylation of dapsone, a non-carcinogenic arylamine, may, therefore, provide a host susceptibility measure of risk of developing bladder cancer. To investigate this possibility, the dapsone recovery ratio, a phenotypic measure of the efficiency of dapsone hydroxylation, has been measured in a case control study in an urban UK population, comparing patients with aggressive bladder cancer (n = 33), non-aggressive bladder cancer (n = 60) and controls (n = 108). Dapsone recovery ratio in controls exhibited a unimodal distribution. Patients with aggressive bladder cancer had a similar distribution but significantly lower mean value (p < 0.005). Logistic regression analysis, controlling for sex, age, smoking habit and alcohol consumption confirmed a significant (p < 0.05) association between the dapsone recovery ratio and aggressive bladder cancer. Subjects in the lowest tertile of dapsone recovery ratio had a relative risk to 5.4-fold greater than subjects in the upper tertile (p < 0.009), and a trends test was significant (p < 0.001). There was no significant association between dapsone recovery ratio and non-aggressive bladder cancer. These results do not support the hypothesis that the drug metabolizing enzymes involved in dapsone N-hydroxylation are involved in causing bladder cancer. Instead, they suggest the opposite, the observation that low enzyme activity was associated with increased risk is consistent with this enzyme providing a detoxification mechanism for environmental procarcinogens.

Case-Control Studies↗
PubMed1994

Recurrent symptoms of urinary tract infection in eight patients with refluxing ureteric stumps.

OBJECTIVES: To evaluate and discuss the recurrent symptoms presented by eight patients with refluxing ureteric stumps. PATIENTS AND METHODS: Eight patients (three boys, five girls; mean age: 8 years, range 11 months-14 years) with refluxing ureteric stumps presented with recurrent urinary tract infections. Six developed symptoms mimicking pyelonephritis, even though the kidney had been partially [5] or totally [3] removed. The stump was removed in all patients. RESULTS: The stumps that were excised measured between 5 and 10 cm in length and were always dilated and inflamed. The results of histological examination and follow-up are reported. CONCLUSIONS: A dual approach is recommended when complete excision of the kidney and ureter is required. Symptoms of pyelonephritis are not pathognomonic of parenchymal infection but reflect infection above the vesico-ureteric junction. The distinction between supra-junctional and infra-junctional urinary tract infections seems more appropriate and is discussed.

Adolescent↗
PubMed1993

Magnetic resonance imaging in the staging of bladder cancer.

Magnetic resonance imaging (MRI) scans were performed on 55 bladder cancer patients on whom clinicopathological staging was available from transurethral resection and cystectomy specimens. The overall accuracy of MRI scanning in this group was 84%, although true concordance rates are debatable without open surgical correlation. In the subgroup of 25 patients who had accurate open surgical correlation (from cystectomy, laparotomy or post mortem) the concordance rate was 76% with MRI. Errors occurred mainly in the T3 group of tumours, with 2 being overstaged and 2 being understaged out of a total of 12 in the open surgical correlation group (66% accuracy). Difficulties were also encountered in staging tumours at the bladder base, with an error rate of 22% (2 of 9) for T4 tumours in this area. With regard to lymph node staging there was a 100% (5 of 5) specificity in defining pathologically involved nodes but there was a false negative rate of 15% (3 of 19). Although it has many advantages over CT scanning, MRI produces a significant error rate in terms of over- and under-staging invasive tumours. There are difficulties associated with detecting minimal involvement of adjacent organs and lymph nodes as well as determining the exact depth of muscle penetration. Improvements may come in the future with the use of contrast enhancement agents such as gadolinium as well as more advanced machines.

Humans↗
PubMed1992

Intravesical BCG treatment for superficial bladder cancer: long-term results using two different strains of BCG.

A total of 21 patients received intravesical BCG for the prevention of recurrence of superficial transitional cell carcinoma of the bladder. Twelve patients received the Glaxo strain and 9 the Pasteur strain of the bacillus. Although thought to have different anti-tumour activities owing to a difference in antigenicity, these 2 strains produced similar tumour-free rates at 5 years' mean follow-up with an overall tumour-free rate of 43%.

Administration, Intravesical↗
PubMed1992

99mTechnetium-labelled red blood cell scintigraphy as an alternative to angiography in the investigation of gastrointestinal bleeding: clinical experience in a district general hospital.

99mTechnetium-labelled red blood cell scintigraphy (99mTc RBC scintigraphy) was used as the second-line investigation to localise bleeding in 23 patients (11 male, 12 female; mean age 67 years) presenting with active bleeding per rectum. Scintigraphy was available on a 24 h basis. A total of 18 patients had positive scans (78%). Surgery was performed urgently in 11 patients and the site of bleeding, as predicted by scintigraphy, was confirmed in 9 (82%). 99mTc RBC scintigraphy was less useful in patients who were not bleeding actively or who were being investigated for chronic anaemia. This study suggests that 99mTc RBC scintigraphy can play a useful role in the preoperative localisation of unexplained gastrointestinal bleeding in hospitals with nuclear medicine facilities, but confirms it has little place in the management of patients unless they are bleeding actively.

Adult↗
PubMedDate not supplied

Internet websites selling herbal treatments for erectile dysfunction.

The objective of the study was to investigate the safety and reliability of internet websites selling and providing medical information regarding herbal substitutes for Viagra. Using keywords 'Herbal' and 'Viagra', websites selling and providing medical information regarding herbal substitutes were identified. The top 50 sequential sites were assessed for safety and reliability against the Health on the Net (HON) criteria. Medically trained staff provided information in only 21% of the sites yet just 24% stated that the information was not a replacement for medical advice. No sites warned patients about erectile dysfunction (ED)-associated cardiovascular disease. In all, 88 and 70% of sites indicated drug efficacy and ingredients but only 36 and 21% provided contraindications and side effects, respectively. All sites fell short of the HON requirements. In conclusion, acquiring medical information and herbal substitutes for ED from the internet is convenient and easy. However, patients should be cautious as safety and reliability of this approach is poor.

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