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Biomedical subjects

A C Buck

Publications and source records attributed to A C Buck.

At least 37 records · Page 2Linked to original sources

Treatment of patients with advanced cancer of the prostate using a slow-release (depot) formulation of the LHRH agonist ICI 118630 (Zoladex).

Twenty two patients with advanced carcinoma of the prostate have been treated for up to 3 months with the slow-release (depot) formulation of the luteinizing hormone-releasing hormone (LHRH) agonist ICI 118630. Patients were randomized to receive one of three different doses of ICI 118630 of 0.9, 1.8 or 3.6 mg. The depot preparation was injected subcutaneously every 4 weeks. At the highest dose, the concentration of testosterone in serum was significantly reduced to castrate values after 2-3 weeks of therapy. The smaller doses of ICI 118630 (1.8 or 0.9 mg every 4 weeks) similarly reduced serum testosterone concentrations although, at the lowest dose, testosterone values were not suppressed in all patients during the first month. Hormonal changes were accompanied by subjective clinical improvement in symptomatic patients and there were no significant side effects. The data clearly demonstrate the considerable therapeutic potential of ICI 118630 in the depot formulation for the treatment of advanced carcinoma of the prostate.

Buserelin↗

The influence of renal prostaglandins on urinary calcium excretion in idiopathic urolithiasis.

Hypercalciuria is well recognized as an important factor in the cause of idiopathic calcium stone disease. Identification of the exact mechanism for the renal tubular handling of calcium has proved elusive, hence, treatment methods to alter the concentration of urine calcium in hypercalciuric stone formers have hitherto been non-specific. It is now well established that renal prostaglandins influence intrarenal hemodynamics and tubular electrolyte excretion. As the renal handling of sodium and calcium is intimately related, the possibility that the mechanism underlying hypercalciuria may be prostaglandin mediated was considered. Experiments were performed in conscious Sprague-Dawley rats (n = 10) to determine the changes in calcium excretion following prostaglandin synthetase inhibition with indomethacin. Calcium excretion was significantly reduced (p less than 0.01), compared with control animals (n = 10). Further experiments were performed in anesthetized monkeys (Macaca fascicularis) to see if the inhibitory effect of indomethacin was reversible. Exogenous prostaglandin (PGE2) infusion resulted in a marked calciuretic response without producing changes in glomerular filtration rate or blood pressure. Forty-three hypercalciuric patients were treated with a prostaglandin inhibitor for periods ranging from 2 to 4 weeks, and all showed a significant fall in urinary calcium excretion to within the normal range. This clinical and experimental study suggests that prostaglandin (PGE2) is a hormone which determines the renal handling of calcium by influencing renal tubular function.

Animals↗

Inhibition of experimental nephrocalcinosis with a prostaglandin synthetase inhibitor.

Nephrocalcinosis was induced in a group of experimental rats by means of intraperitoneal injections of 10% calcium gluconate. Two further groups of rats were treated with indomethacin and flurbiprofen (Froben) before receiving the i.p. calcium gluconate, to study the effects of prostaglandin inhibition on the process of renal parenchymal calcification. Tissue calcification was studied by means of contact microradiography and histology. Quantitative calcium analysis was by means of energy dispersive analysis of X-rays (EDAX). There was a marked inhibition of cortical nephrocalcinosis and a significantly reduced calcium concentration (P less than 0.005) in the animals treated with a prostaglandin inhibitor compared with the animals given i.p. calcium gluconate alone. This study suggests that prostaglandins are involved in the process of renal parenchymal calcification and may be aetiologically significant in the pathogenesis of stone formation.

Animals↗

Renal prostaglandins and calcium excretion in urolithiasis.

Forty-three hypercalciuric patients were treated with a prostaglandin synthetase inhibitor (indomethacin, twenty-eight patients: flurbiprofen, fifteen patients) for periods ranging from 2-4 weeks and all showed a significant fall in urinary calcium excretion to within the normal range (p less than 0.0005). This clinical and experimental study indicates that prostaglandins influence the renal tubular handling of calcium and could be of importance in the pathogenesis of stone formation.

Animals↗

Osteitis pubis as a mimic of prostatic pain.

Thirty-five patients with pain suggesting a prostatic origin but with no evidence of active prostatic inflammation presented between 1979 and 1982 and were diagnosed as having osteitis pubis. The clinical presentation, diagnosis and treatment of osteitis pubis are presented together with the results of treatment.

Adolescent↗

The influence of renal prostaglandins on glomerular filtration rate (GFR) and calcium excretion in urolithiasis.

In a clinical study of 275 idiopathic stone formers the GFR was significantly raised in hypercalciuric patients compared with normal controls P less than 0.001). The possibility that the mechanism underlying hypercalciuria and raised GFR may be prostaglandin-mediated was considered because it is now well established that prostaglandins regulate intra-renal haemodynamics and influence tubular electrolyte excretion. Experiments were performed in conscious Sprague Dawley rats to determine the changes in calcium and sodium excretion following prostaglandin synthetase inhibition with indomethacin. Both calcium and sodium excretion together with urine flow were significantly reduced (P less than 0.002). Further experiments were performed in anaesthetised monkeys (Macacca fascicularis) to see if the inhibitory effect of indomethacin was reversible. Exogenous prostaglandin (PGE2) infusion resulted in a marked calciuretic response without producing changes in GFR or blood pressure. Selected hypercalciuric patients were treated with indomethacin, which resulted in a significant fall in urinary calcium excretion (P less than 0.001). This clinical and experimental study suggests that PGE2 is the hormone which determines the renal handling of calcium by controlling renal tubular function.

Adolescent↗

The advantages of 99mTc DTPA(Sn) in dynamic renal scintigraphy and measurement of renal function.

The results of excretion urography (IVU) and dynamic renal scintigraphy using 99mTc DTPA(Sn) were compared in 109 urological patients. Computer analysis of the gamma camera data provided a reproducible, accurate, qualitative and quantitative assessment of renal function and was found to be superior to urography in the detection of morphological defects of the renal parenchyma and in the identification of early upper tract obstruction. The radio-isotope study is a safe, non-invasive investigation, easily performed on an out-patient basis, requires no prior preparation and is without significant radiation hazard to the patient.

Adolescent↗

Rectovesical fistula secondary to prostatic carcinoma.

Rectal invasion by carcinoma of the prostate occurs in a significant number of cases (approaching 10%). A case of a rectovesical fistula owing to direct extension of a prostatic carcinoma is reported. This complication of the disease has not been described previously.

Adenocarcinoma↗

Follow-up of prostate carcinoma with serial bone scanning using cyclotron-produced 18-fluorine.

Seventy-four patients with carcinoma of the prostate were studied annually by combined radiological and 18F scintigraphy over a 5-year period. Of the patients who have no radiological evidence of bone metastases, 25% have a positive 18F bone scan. Follow-up of these patients has shown that scan abnormalities perceded x-ray changes from between 1 to 4 years. False negative scans were not seen with 18F which allows for greater accuracy in the detection of skeletal metastases. Teh accurate staging of carcinoma of the prostate cannot be made without bone scanning. Preliminary results with 111In bleomycin as an adjunct to 18F have shown this to be a useful radio-pharmaceutical to distinguish metastases from benign lesions, and further studies are warranted.

Aged↗

Bladder dysfunction and neuropathy in diabetes.

Established urodynamic and electrophysiological techniques have been applied to assess the frequency and extent of autonomic and peripheral neuropathy in 60 subjects with diabetes mellitus; 38 were diabetics with suggestive symptoms and the others were representative newly diagnosed (11) or treated (11) diabetics. Objective evidence neuropathic bladder dysfunction was detected in 43 of them (71.7%). The commonest abnormality was a hypotonic, insensitive large capacity bladder, which condition was usually asymptomatic. Less freuqently (15%) was this complicated by bladder decompensation and sphincter involvement, resulting in excessive residual urine and infection; some of these had bladder paralysis with chronic painless retention of urine (7%). Electrophysiological studies found a sensory defect in the lower limbs in all tested patients (100%), and in 41 patients (69%) as associated motor conduction abnormality, which was more frequent and marked in the lower than the upper limb. These functional abnormalities appeared to be related to the severity of diabetes, but less to its duration. Indeed of 11 newly diagnosed diabetics tested 7 had a peripheral neuropathy and 4 urodynamic abnormalities. The high incidence of bladder dysfunction and peripheral neuropathy in this series indicates the frequency of subclinical diabetic neuropathy and a factor needing more emphasis in diabetic uropathy.

Adult↗

Serial Fluorine-18 bone scans in the follow-up of carcinoma of the prostate.

74 patients with prostatic cancer were studied annually by combined radiological and fluorine-18 scan survey over a 5-year period. The results of the long term follow-up of bone cans is reported. At the time of the initial diagnosis 71-5% of the patients had advanced disease and 56% had radiological or scan evidence of metastases. A critical evaluation of the scans resulted in the detection of early bone lesions in 25% of patients with no radiological evidence of metastases. Follow-up of these patients has shown that scan abnormalities preceded radiological changes from between 1 to 4 years and there was good correlation proven histologically by bone biopsy or autopsy in more than half of the patients. In patients with a positive bone scan and positive X-rays the scan abnormalities were more extensive than the corresponding X-ray lesions. When bone healing occurred with endocrine treatment this was more readily apparent on the X-rays. False negative scans were not seen with fluorine-18 which allows for greater accuracy in the detection of skeletal metastases. Bone scanning has enabled correct staging to be carried out. This study confirms the high incidence of cardiac and vascular complications in patients treated with oestrogens.

Aged↗

Disorders of micturition in bacterial prostatitis.

Measurements of urinary flow rate were performed in 16 patients with established prostatitis before and after a course of antimicrobial therapy. Before treatment the maximum flow rates were poor with abnormal flow curves and significant improvement in voiding characteristics were observed with treatment (P less than 0.01). A preliminary electrophysiological (EMG) study of sphincter activity suggested that the obstruction to the flow of urine was at least in part due to failure of the external sphincter to relax during micturition. Although the total number of cases in this series was small the study showed that prostatitis was associated with a disorder of micturition which correlated with the other clinical features of the disease and could be objectively evaluated. Eradication of infection restored normal conditions in the lower urinary tract.

Adolescent↗