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Biomedical subjects

A C Buck

Publications and source records attributed to A C Buck.

At least 19 recordsLinked to original sources
PubMed1994

Evening primrose oil reduces urinary calcium excretion in both normal and hypercalciuric rats.

Hypercalciuria is an important risk factor in the aetiology of idiopathic urolithiasis and many treatment modalities in clinical practice are directed towards reducing urinary calcium excretion. There are no natural animal models of hypercalciuria, such as the spontaneous hypertensive rat; however, the streptozotocin-diabetic rat is accepted as a good model for studies of disordered renal function associated with diabetes mellitus. Hypercalciuria is a prominent feature of the streptozotocin-diabetic rat and the model was, therefore, used to study the influence of evening primrose oil on urinary calcium excretion. Twenty rats divided into two groups of ten rats each were maintained on either normal rat chow (group 1) or primrose oil enriched diet (group 2) for 10 weeks. At 4 weeks both groups of rats were made diabetic with streptozotocin. Urine calcium measurements were serially performed before commencement of the diet, during the pre-streptozotocin (pre-diabetic) phase and during the post streptozotocin (diabetic) phase. The urine calcium excretion was significantly less in the primrose oil fed animals during both the pre-diabetic phase and the diabetic phase compared with the rats on the normal rat chow. These results indicate that evening primrose oil, a rich source of gamma-linolenic acid, helps to reduce urine calcium excretion in normal animals as well as in the hypercalciuric streptozotocin-diabetic rat. Dietary modifications with long-chain omega-6 and omega-3 fatty acids might be a useful adjunct in the treatment of idiopathic hypercalciuric urolithiasis.

Animals↗
PubMed1991

The protective role of eicosapentaenoic acid [EPA] in the pathogenesis of nephrolithiasis.

The low incidence of atherosclerosis and other degenerative diseases including stone disease in the Greenland Eskimo has been attributed to their high consumption of oily fish with its high concentration of eicosapentaenoic acid (EPA). Man cannot synthesis EPA from the precursor essential fatty acid, linolenic acid, and can only assimilate preformed EPA present in fish and fish oil, to bring about a change in the pathway of eicosanoid metabolism from the n-6 to the n-3 series. With a westernised diet the oxygenated products of renal prostaglandin synthesis are metabolites of the n-6 series and these are known to play an important role in several pathophysiological states including stone disease. Our previous studies have shown a relationship between prostaglandin activity and urinary calcium excretion and it would seem that the initiating factor/s for stone formation trigger the mechanisms for prostaglandin synthesis resulting in the biochemical abnormalities associated with stone disease. The Eskimo may be protected from these events by possession of an eicosanoid metabolism that follows an n-3 pathway. To test this hypothesis experiments were performed using an animal model of nephrocalcinosis. The animals were divided into three groups; one group was given an intra-peritoneal injection of 10% calcium gluconate daily for 10 days to induce nephrocalcinosis; a second group was fed MaxEPA fish oil before and during the calcium gluconate injections and a third group only received an intra-peritoneal injection of N saline. A group of 12 recurrent, hypercalciuric/hyperoxaluric stone-formers were treated with fish oil for eight weeks to study the effects on solute excretion. Nephrocalcinosis, which was readily produced in the control animals, was prevented in the experimental animals by pre-treatment with fish oil and urine calcium excretion was significantly reduced. The urinary calcium and oxalate excretion in the recurrent, hypercalciuric stone-formers was significantly reduced with fish oil treatment over an eight week period. There were no untoward side-effects. These studies indicate that the incorporation of EPA in the diet as a substitute metabolic pathway could be a unique way of correcting the biochemical abnormalities of idiopathic urolithiasis.

Adult↗
PubMed1991

An outbreak of waterborne cryptosporidiosis in Swindon and Oxfordshire.

An outbreak of cryptosporidiosis resulted in 516 cases in Wiltshire and Oxfordshire. The outbreak caused widespread interest and led to an official inquiry. The majority of cases were in children; 8% of cases were admitted to hospital and the median duration of illness was 3 weeks. The geographical distribution of cases matched the distribution of water supplies from three treatment works and cryptosporidium oocysts were found at these works and in the treated water. Attack rates in electoral wards supplied by the three treatment works were significantly higher than in other wards. The cause of the outbreak appeared to be the failure of normal treatment to remove oocysts. Measures at the treatment works reduced the number of oocysts detected in treated water, after which the outbreak came to an end. The conclusion of the investigations was that cryptosporidiosis is a risk of conventionally treated public water supplies.

Adolescent↗
PubMed1990

In vitro evaluation of the pollen extract, cernitin T-60, in the regulation of prostate cell growth.

Nine human-derived cancer and non-cancer continuous cell lines were employed to evaluate the relative in vitro activity of the pollen extract, Cernitin T-60. Responses of the cell lines to the drug were assessed by measuring growth and cell survival as determined by cell count. The results demonstrated that of the 9 continuous cell lines tested, only those derived from the human prostate were growth inhibited by the pollen extract, whereas the non-prostate derived cells exhibited variable degrees of resistance to the T-60. The selectivity of the drug for the prostate cell lines was even more pronounced in the hormone-independent models, suggesting that there might be a place for the pollen extract in the control of abnormal growth in hormone-insensitive cells.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1990

Treatment of outflow tract obstruction due to benign prostatic hyperplasia with the pollen extract, cernilton. A double-blind, placebo-controlled study.

Whilst prostatectomy remains the "gold standard" for the treatment of outflow tract obstruction due to benign prostatic hyperplasia, medical treatment--if only for symptomatic relief--appears to be an attractive alternative. Most of the pharmacological agents in use block the hormonal or the sympathetic neurological pathways that influence prostate growth and function. All of these drugs are known to have side effects. Sixty patients with outflow obstruction due to benign prostatic hyperplasia (BPH) were entered into a double-blind, placebo-controlled study to evaluate the effect of a 6-month course of the pollen extract, Cernilton. There was a statistically significant subjective improvement with Cernilton (69% of the patients) compared with placebo (30%). There was a significant decrease in residual urine in the patients treated with Cernilton and in the antero-posterior (A-P) diameter of the prostate on ultrasound. However, differences in respect of flow rate and voided volume were not statistically significant. It is concluded that Cernilton has a beneficial effect in BPH and may have a place in the treatment of patients with mild or moderate symptoms of outflow obstruction.

Aged↗
PubMed1989

Treatment of chronic prostatitis and prostatodynia with pollen extract.

Chronic abacterial prostatitis and prostatodynia are notoriously difficult both to diagnose and to treat. These patients tend to have received several courses of antibiotics, antiinflammatory agents or adrenergic blockade and various other therapeutic manoeuvres with little success. The pollen extract, Cernilton, is reported to be effective in the treatment of this condition and we present the results of an open trial with Cernilton in a group of 15 patients with chronic prostatitis and prostatodynia. In 13 patients there was either complete and lasting relief of symptoms or a marked improvement; 2 patients failed to respond. Cernilton was found to be effective in the treatment of chronic prostatitis and prostatodynia. Its precise mode of action is not known, although experimental studies suggest that it has anti-inflammatory and anti-androgenic properties.

Adult↗
PubMed1988

The use of noxythiolin (Noxyflex 'S') as an antiseptic irrigant in upper urinary tract drainage following percutaneous nephrolithotomy.

Percutaneous nephrostomy drainage for the relief of obstruction or stone removal has become a common procedure. Despite the routine use of prophylactic antibiotics, nephrostomy urine frequently becomes infected (approximately 30% of cases). Noxythiolin irrigation has been used to prevent and treat bladder infections. A double-blind, placebo controlled study was carried out in 20 patients undergoing a single-stage percutaneous nephrolithotomy to evaluate the use of noxythiolin as an upper urinary tract antiseptic. In the patients whose nephrostomy tubes were irrigated with a 2.5% solution of noxythiolin, significant bacterial infection was eliminated from the nephrostomy urine and colonisation of the catheter tip was markedly reduced. Noxythiolin also rendered pre-operative infected bladder urine sterile. There were no untoward local or systemic sequelae in either group of patients. This study indicates that irrigation of the upper urinary tract with noxythiolin solution is safe and may be a useful adjunct to reduce the risk of sepsis in patients undergoing percutaneous drainage procedures.

Adolescent↗
PubMed1987

The treatment of metastatic prostatic cancer with the slow release LH-RH analogue Zoladex ICI 118630.

The clinical and endocrine response to a depot preparation of the LH-RH analogue ICI 118630 (Zoladex) was assessed in 55 untreated patients with advanced prostatic cancer. Whereas gonadal androgen suppression was achieved in all patients, subjective and objective clinical response occurred in only 69%, indicated by a relief of bone pain, a decrease in the size of the primary tumour and lymph node metastases and improvement in bone scan appearances. A third of these patients, however, subsequently showed progression of their disease. Serious side effects were not encountered in this study. The depot formulation is a simple, safe and convenient method of administering Zoladex and offers an alternative treatment for metastatic prostatic cancer.

Acid Phosphatase↗
PubMed1985

Ultrasound assessment of residual urine. A quantitative method.

A method of measuring residual urine volume using ultrasound is described. The volume is computed from serial parallel sections of the bladder. This method is found to be significantly more accurate than previously reported techniques and is quick and easy to perform.

Aged↗
PubMed1984

Ultrasonic appearances associated with prostatic inflammation: a preliminary study.

Per-rectal ultrasonography was performed on 40 patients in whom a diagnosis of prostatitis had been made on the basis of symptoms and signs of prostatic inflammation confirmed by bacteriology, microscopy or pH changes of expressed prostatic secretion. Certain ultrasonic features were present in all patients to a variable degree. A change in volume and weight of the prostate could be an indicator of treatment response.

Adolescent↗
PubMed1984

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↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1982

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↗