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Biomedical subjects

R J Shearer

Publications and source records attributed to R J Shearer.

At least 19 recordsLinked to original sources
PubMed1992

Aromatase inhibition: 4-hydroxyandrostenedione (4-OHA, CGP 32349) in advanced prostatic cancer.

We report the use of the steroidal aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA, CGP 32349), in the management of patients with advanced, hormone resistant, prostatic cancer. Eighteen of 25 patients (72%) showed a subjective response, mainly in the form of pain relief and increased performance. There were no objective improvements. A tumour flare occurred in 17/25 (68%). Detailed endocrine studies were performed during treatment. These showed that suppression of serum oestradiol levels occurred in 19/25 (76%) of patients during treatment with 4-OHA. Serum levels of androstenedione increased in 9/14 patients (64%). Concentration of serum testosterone and 5 alpha-dihydrotestosterone were elevated in 3/14 (21%) and 2/11 (18%) patients respectively. There appeared to be no correlation between response or tumour flare and changes in steroid levels during treatment with 4-OHA. The mechanism of action of 4-OHA in palliating patients with advanced prostatic cancer remains obscure. 4-OHA or its metabolites may be acting on metastatic bone metabolism via effects on oestrogen related osteoclastic and osteoblastic activity. Further investigation of the effects of aromatase inhibitors on prostatic biology, and bone metabolism in patients with metastatic prostate cancer, would appear worthwhile.

Aged↗
PubMed1992

Hormonal cytoreduction and radiotherapy for carcinoma of the prostate.

We report the effect on prostatic volume of the administration of the luteinising hormone-releasing hormone (LHRH) analogue goserelin in 22 patients with locally advanced carcinoma of the prostate; 20 achieved a significant reduction in volume, the median volume being 66 ml before treatment (range 40-130) and 30 ml after 17 weeks (range 13-47). If used before external beam radiotherapy (RT), volume reduction will permit smaller boost fields and thus potentially reduce adverse radiotherapy effects. In addition, reducing tumour volume before RT may lead to an increase in local control. We discuss the possible role of hormonal volume reduction in the management of prostatic cancer.

Buserelin↗
PubMed1992

Effects of 4-hydroxyandrost-4-ene-3,17-dione and its metabolites on 5 alpha-reductase activity and the androgen receptor.

The steroidal aromatase inhibitor, 4-hydroxyandrost-4-ene-3,17-dione (4OHA) and its metabolites, 4-hydroxytestosterone (4OHT), 3 beta,17-dihydroxy-5 alpha-androstan-4-one (metabolite A) and 3 alpha, 17-dihydroxy-5 beta-androstan-4-one (metabolite B) were evaluated as inhibitors of the human prostatic 5 alpha-reductase enzyme and for binding to the rat prostatic androgen receptor. 4OHA and 4OHT were weak inhibitors of 5 alpha-reductase with IC50 values of 15-29 microM. Metabolites A and B had no significant inhibitory activity. 4OHA and metabolites A and B bound weakly to the androgen receptor. The binding affinities (RBA) relative to mibolerone (RBA = 100) were 0.085, 0.485 and 0.016, respectively. However, 4OHT (RBA = 75) was a more potent binder than the endogenous androgen 5 alpha-dihydrotestosterone (RBA = 66). The ability of these metabolites, in particular 4OHT, to bind to the androgen receptor may explain the in vivo androgenic activity of 4OHA.

5-alpha Reductase Inhibitors↗
PubMed1991

The clinical effects of prolonged treatment of patients with advanced cancer with low-dose subcutaneous interleukin-2 [corrected].

Thirty-five patients with advanced malignant disease have been treated as outpatients with increasing doses (0.1-100 mcg) of interleukin 2 (IL2) by once daily self-administered subcutaneous (s.c.) injection, 5 days weekly for 8 weeks followed by a 4 week observation period. Systemic side effects were not experienced by patients at the 3 lower doses. Three patients required dose reduction from 100 mcg daily because of intolerance (fever, rash, lethargy, nausea and vomiting) and one patient was discontinued because of dyspnoea. We observed immunological effects at the 100 mcg dose (but not at the lower doses). These consisted of (a) a modest sustained lymphocytosis, (b) eosinophilia in six (out of nine) patients and (c) a significant rise in IL2-stimulated peripheral blood lymphocyte activated killer (LAK) cell activity in six (out of nine) patients to a mean of 2.0 times pretreatment levels (P less than 0.01). Two (out of nine) patients with renal cell carcinoma treated with 100 mcg daily had partial responses of duration 4 and 9 months respectively and a further three had disease stabilisation for at least 3 months. Low dose long-term s.c. IL2 is clinically and immunologically active, and in comparison to other IL2 regimens it has minor toxicity and is easy to administer. These characteristics make low dose s.c. IL2 suitable for study in the adjuvant setting.

Adult↗
PubMed1991

Role of ultrasound in the investigation of haematuria after normal intravenous urography and cystoscopy.

The initial investigation of haematuria in the adult includes intravenous urography and cystoscopy. If these investigations reveal no cause for haematuria we propose that renal ultrasound should be considered, and illustrate this with two series of patients from different hospitals (147 from St. Peter's Hospitals, 35 from St. James' Hospital, Balham, London) with primary adenocarcinoma of the kidney.

Aged↗
PubMed1991

Comparison of aromatase activity in human prostatic, testicular and placental tissues.

The aromatase enzyme was quantified by the release of tritiated water from [1 beta-3H] androstenedione. Tritiated water was released by the crude homogenates in 4 of 18 samples of benign prostatic hyperplasia tissue and one of 5 samples of prostate carcinoma tissue. However, this apparent aromatase activity was not inhibited by 4-hydroxyandrostenedione (0.5 and 5.0 microM), and none of the particulate fractions (100,000 g pellet) prepared from each of the prostatic tissues exhibited aromatase activity. Particulate fractions from rat ovary (n = 3) and human testes (n = 6) displayed significant aromatase activity (mean values of 9.9 and 0.033 nmol estrone formed/g protein/h, respectively). The testicular aromatase was inhibited by aminoglutethimide, 4-hydroxyandrostenedione and CGS 16949A with IC50 values of 6.4, 0.17 and 0.0017 microM, respectively. These are of a similar order to values obtained with the aromatase enzyme from human placental microsomes (14, 0.43 and 0.0075 microM, respectively).

Androstenedione↗
PubMed1990

Aromatase inhibition in advanced prostatic cancer: preliminary communication.

We report the results of the first use of a steroidal aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA, CGP 32349), in the palliation of patients with advanced, hormone resistant, prostatic cancer. Twelve of 19 patients (63%), who had relapsed following castration and other therapies, gained significant pain relief following weekly intramuscular injections of 4-OHA. Five patients (31%) experienced a transient 'tumour flare', represented by an increase in bone pain soon after commencing treatment. The mechanism of action of 4-OHA in palliating patients with advanced prostatic cancer is obscure at present, but may represent an important new treatment modality which may lead to greater insight into prostatic biology.

Aged↗
PubMed1989

Prognostic factors in a T3 bladder cancer trial. Co-operative Urological Cancer Group.

Information on primary tumour size, status of the pelvic lymph nodes, histological type and macroscopic tumour appearance, as well as age and sex, was available at presentation for 394 patients in the Co-operative Urological Cancer Group's prospective randomised trial for T3 cancer of the urinary bladder. An apparently significant prognostic effect of age and sex was shown to be entirely consistent with the effect of natural mortality. Primary tumour size was found to be the single most powerful prognostic factor (P = 0.002), followed by nodal status (P = 0.02). These factors do not act independently. Multivariate analysis showed that 75% of the effect of all the six variables and their first order interactions could be explained by a single prognostic grouping based on tumour size and nodal status only. Three levels for this grouping are proposed: node-negative small tumour, node-negative moderate tumour and either node-positive or large tumour. The 3-year survival probabilities for the three prognostic groups were 85.7% (95% CI 57.2 and 96.4%), 60.3% (48.0 and 71.5%) and 33.3% (23.5 and 44.8%) respectively.

Age Factors↗
PubMed1988

The effects of aminoglutethimide and hydrocortisone, alone and combined, on androgen levels in post-orchiectomy prostatic cancer patients.

Aminoglutethimide has been used in combination with hydrocortisone in patients with advanced prostatic cancer with the rationale that it causes a 'medical adrenalectomy'. Both objective and subjective responses have been recorded. We have examined the effect of AG and HC alone and in combination on plasma androgen levels throughout the day in two studies on 11 such patients. Whilst AG combined with HC led to a significant suppression of both testosterone and androstenedione levels, the suppression with HC alone was significantly greater, indicating that any beneficial clinical effects of AG in these patients is not due to its suppression of adrenal androgen secretion.

Aged↗
PubMed1988

Adjuvant chemotherapy in T3 carcinoma of the bladder. A prospective trial: preliminary report.

We report the early results of a multi-centre, randomised prospective trial of neoadjuvant and maintenance chemotherapy with methotrexate (MTX) in 376 patients with advanced (T3) carcinoma of the bladder. In patients under 65 years of age, treatment consisted of radical radiotherapy (64 Gy) or, in some centres, pre-operative radiotherapy (44 Gy) and elective cystectomy. All patients over 65 had radical radiotherapy. MTX was administered to 188 patients. There was no increase in toxicity attributable to the MTX. MTX did not significantly increase the proportion of patients whose tumours responded to radiotherapy; 50% (70/141) responded to radiotherapy and 56% (76/136) to MTX radiotherapy. The development of metastases and survival was also similar in both groups (3-year survival: radiotherapy 37.3%, MTX + radiotherapy 38.6%). We report the logistic difficulties of the administration of prolonged courses of maintenance chemotherapy. Further controlled trials of neo-adjuvant chemotherapy in advanced bladder cancer are required, involving more active regimes.

Aged↗
PubMed1988

Chyluria as a cause of haematuria in patients from endemic areas.

Chyluria is an unusual cause of haematuria in temperate regions and is rarely considered even when no apparent cause has been found. We report 3 Guyanese men who presented with macroscopic haematuria in whom pyelo-lymphatic fistulae were found. In none of the patients were the symptoms severe enough for surgical disconnection of the fistula to be required.

Adult↗
PubMed1988

Prostatectomy: patients' perception and long-term follow-up.

We have reviewed 500 consecutive prostatectomies with a follow-up period of between 5 and 8 years; 184 surviving patients were sent a questionnaire and patients with residual urinary symptoms were interviewed, examined and a flow rate was performed. The operative mortality rate was 0.5%. Patients who presented with retention of urine had a high mortality rate in the first 3 years after the operation. Thirty-six per cent of surviving patients with chronic retention and 24% of those who underwent elective prostatectomy had residual urinary symptoms at the time of the study. Of patients who were sexually active pre-operatively, 34% felt that the operation was responsible for a deterioration in their sex lives. The incidence of retrograde ejaculation was 93%. It was concluded that prostatectomy is a safe operation with good patient acceptability. Patients with symptoms of prostatism require careful evaluation before prostatectomy and sexually active patients should be warned of the risks of impotence and decreased satisfaction due to retrograde ejaculation.

Age Factors↗
PubMed1986

Metabolic consequences of forced diuresis following prostatectomy.

The efficacy and metabolic consequences of a standardised forced diuresis regime following prostatectomy were studied in three parts. A retrospective review of 372 patients. A detailed prospective study of blood and urine electrolyte changes in 25 patients. A prospective study of urinary oxalate levels in 15 patients. The regime was effective in safely preventing post-operative clot retention. In 54% of patients the plasma sodium fell below 135 mmol/l. Hypokalaemia was mild and transient except in patients on long-term diuretics. There was a significant per-operative fall in serum calcium levels. It was concluded that forced diuresis is a safe and effective method of reducing clot retention following prostatectomy. The high incidence of post-operative hyponatraemia suggests that absorption of glycine solution at transurethral prostatectomy is a common occurrence.

Creatinine↗
PubMed1985

Oncogenes and bladder cancer.

We screened a series of 15 superficial and invasive transitional cell carcinomas of the bladder for transforming activity on the NIH/3T3 transfection assay. In addition, by obtaining tumour DNA and normal lymphocyte DNA from the same patients we looked for evidence of gene amplification or rearrangement of the c-H-ras-1 gene by Southern blot analysis. One patient (with a grade 2T1 tumour) was shown to have an activated oncogene on the NIH/3T3 transfection assay and this was identified as a c-H-ras-1 gene. We could find no evidence of gene amplification or rearrangement of this gene in any tumour. The significance of activation of ras oncogenes in the pathogenesis of human bladder carcinoma is unclear.

Carcinoma, Transitional Cell↗