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Biomedical subjects

J R Burns

Publications and source records attributed to J R Burns.

At least 37 records · Page 2Linked to original sources
PubMed1989

Incidence and clinical significance of subclinical scrotal varicoceles.

A total of 40 infertile men with a normal physical examination underwent gonadal venography to determine the presence of a subclinical varicocele. Of the patients 19 had a left and 3 had a right subclinical varicocele. A total of 21 patients underwent radiographic occlusion of the varicoceles, while 1 required surgical ligation of the internal spermatic vein. Of the 22 patients 13 have been followed for greater than 6 months after correction of the varicocele. In these patients there has been a small but significant increase in sperm number after varicocele occlusion. No significant changes in either sperm motility or morphology have occurred. Although most patients do not have any major improvement after occlusion of a subclinical varicocele, some may experience a significant improvement in sperm number after occlusion. The effect on pregnancy rates is not yet known.

Adult↗
PubMed1988

Current operative management of urinary calculi after renal transplantation.

We examined the medical records of renal transplantation patients at our institution to determine the incidence and etiology of renal calculi after renal transplantation. Of 7 patients identified calculi formed on the basis of congenital hyperoxaluria in 2, secondary to chronic urinary infection in 1 and from iatrogenic causes in 4. We review the various surgical and radiological procedures used to treat these renal transplant patients. We also discuss the role of the new treatment modalities in managing urolithiasis in transplant recipients.

Adult↗
PubMed1987

Outpatient extracorporeal shock-wave lithotripsy.

Extracorporeal shock-wave lithotripsy (ESWL) is a new procedure for which patient-management guidelines are still being established. We retrospectively reviewed the first 246 patients treated with ESWL at our facility. Nearly 50 per cent were treated as outpatients, and more than 70 per cent of patients admitted to the hospital were discharged on the first day after ESWL. We conclude that outpatient ESWL is feasible, but that further study is necessary to improve selection of patients for this procedure.

Ambulatory Care↗
PubMed1987

Kinetics of dissolution of calcium oxalate calculi with calcium-chelating irrigating solutions.

Dissolution of calcium oxalate urinary calculi was studied in vitro. Rate constants were calculated by measuring the concentration of calcium in solution during dissolution. Various irrigating agents, including ethylenediaminetetraacetic acid (EDTA) and other calcium-chelating substances, were tested at different concentrations and pH values. EDTA was the most effective agent in dissolving calcium oxalate calculi. When EDTA was used, the rate of dissolution depended on both concentration and pH. At a pH of 7.5 or 10.0, the rate of dissolution increased progressively with the EDTA concentration. At each concentration tested, dissolution was faster at a pH of 10.0 than at a pH of 7.5. Calculated rate constants were extrapolated to determine whether in vivo irrigation with EDTA solutions is clinically practical. Even at an EDTA concentration of 0.03 M at a pH of 7.5, a two mm. calculus could be dissolved within 48 hr. Although dissolution of calcium oxalate calculi is not a practical first-line treatment, it might be a useful adjunct to percutaneous stone removal or extracorporeal shock wave lithotripsy.

Calcium Oxalate↗
PubMed1987

Practical aspects of outpatient extracorporeal shock-wave lithotripsy.

Outpatient ESWL is practical for the majority of patients undergoing treatment. However, careful preoperative evaluation and patient selection are necessary. Approximately 15 per cent of patients treated require a secondary procedure. We believe that pretreatment placement of a ureteral stent aids in the passage of stone fragments.

Ambulatory Care↗
PubMed1986

In vitro dissolution of cystine urinary calculi.

Dissolution of cystine urinary calculi was studied in vitro. Sodium hydroxide, acetylcysteine and tris(hydroxymethyl)aminomethane (tromethamine) were tested for effectiveness in dissolving cystine calculi. Calculi were mounted in a dissolution apparatus. Dissolution rates were calculated from the amount of cystine released into solution per unit time and were compared with linear regression techniques. Calculated dissolution rates of all the irrigating agents tested were similar at a pH of 7.5 and were significantly different at pH 10.0. The most effective agent in the promotion of cystine dissolution was 2 per cent acetylcysteine. Sprague-Dawley rats were used to test the effect of 2 per cent acetylcysteine, 0.3 molar tromethamine and 2 per cent acetylcysteine mixed with 0.3 molar tromethamine on the urothelium. A nephrostomy tube was placed in the left kidney of each rat. The kidneys were irrigated for 3 days with either 2 per cent acetylcysteine, 0.3 molar tromethamine or 2 per cent acetylcysteine mixed with 0.3 molar tromethamine. The rats then were sacrificed at various intervals after infusion. Irrigation with 2 per cent acetylcysteine at a pH of 10 caused an acute inflammatory response at 3 days that was healed almost completely in 4 weeks. The addition of tromethamine to the acetylcysteine did not prevent the inflammatory response.

Acetylcysteine↗
PubMed1986

Percutaneous nephrolithotomy in 86 patients: analysis of results and costs.

We reviewed the hospital records of the first 86 patients having percutaneous nephrolithotomy at University Hospital (Birmingham, Ala) between 1983 and 1985. Variables such as stone location, chemical composition of the stone, history of previous renal surgery, and stone size were examined to determine their effect on complication rate, overall success of stone removal, and hospital cost. The overall success rate for the removal of targeted calculi was 94%. In patients with calculi larger than 1.2 cm, the initial success rate was 63%; such patients often required a second procedure. The mean hospital stay for patients with calcium-containing calculi was 6.8 days (mean hospital cost $5,311). Patients with infection-induced calculi had a mean stay of 11.2 days (mean cost $9,362). Compared with the costs of open surgical procedures for stone removal at our institution, percutaneous nephrolithotomy was 46% less expensive. Complications were minimal in most patients, and no patient required open surgical intervention. Percutaneous nephrolithotomy is an effective procedure for removing renal and ureteral calculi. It is associated with low morbidity and is less expensive than open surgical lithotomy procedures.

Calcium Oxalate↗
PubMed1986

Predisposing factors and prevention of renal calculi.

Over the last few years there have been marked advances in both the surgical and medical treatment of urinary stone disease. At present, we have expectations of decreasing the incidence of stone recurrence in a vast majority of patients with medical therapy alone. While there are still many patients who will continue to develop new stones, decreasing their rate of new stone formation will lessen the need for surgical intervention.

Calcium↗
PubMed1985

An ovarian regression syndrome in the platyfish, Xiphophorus maculatus.

The highly inbred Coatzacoalcos (Cp) strain of the platyfish, Xiphophorus maculatus, was noted for a high percentage of infertile females (XX). The ovaries of approximately one-quarter of all females regress. The time of gonadal atrophy varied from before sexual maturation up to 11 months of age. The gonadotropic zone of the pituitary was hypertrophied in regressed females. Transplants of immature testes and ovarian tissue into the caudal musculature of regressed females and the subsequent maturation of the grafts demonstrated that the ovarian degeneration was not due to pituitary or hypothalamic malfunction or an autoimmune disease. The cause of the gonadal degeneration was apparently localized to the ovary itself. This phenomenon was never observed in males (XY). Regressed ovaries fell into two categories, designated types I and II, with all being characterized by the presence of ductlike structures which resembled male efferent ducts, lined by Sertoli cells. Type I ovaries bore a marked similarity to certain mammalian dysgenetic gonads, while type II ovaries contained many proliferating germ cells and could be compared to the human neoplasm termed gonadoblastoma. It is suggested that the physiological lesion responsible for the ovarian regression syndrome involves the processes that control the determination and differentiation of the germ cells similar to those found in human 46,XY gonadal dysgenesis.

Animals↗
PubMed1985

Vesical endometriosis: a review and 2 case reports.

Vesical endometriosis is uncommon and can result in months or years of morbidity if undetected. We report 2 cases that demonstrate that increased awareness of this entity and expeditious use of appropriate diagnostic techniques can lead to earlier diagnosis and definitive treatment.

Adult↗
PubMed1985

Congenital megacalices in a black woman.

Congenital megacalices is an uncommon anatomical malformation of the kidney. It has been reported previously only in white patients with a strong male predominance. We report congenital megacalices in a black woman.

Adult↗
PubMed1985

Microsurgical vasovasostomy for reversal of elective bilateral segmental vasectomy.

Microsurgical vasovasostomy for the reversal of elective bilateral segmental vasectomy (vasectomy, vas ligation) was done in 57 patients (61 operations) between May 1977 and March 1984. The length of time between elective segmental vasectomy and subsequent vasovasostomy ranged from 12 to 216 months; the longest period between vasectomy and vasovasostomy resulting in a subsequent pregnancy was 108 months. The patency rate was 83%, with 51% of these patients fathering one or more children (overall pregnancy rate of 41%). Unlike previous studies, ours showed no positive correlation between the presence of postvasectomy sperm granulomas and either patency or pregnancy rate after microsurgical vasovasostomy. The major factor that seemed to affect the success of the procedure was the number of years between vas ligation and vasovasostomy.

Adult↗
PubMed1984

Prevention of urinary catheter incrustations by acetohydroxamic acid.

Acetohydroxamic acid was administered in 5 patients to determine its effect in reducing urinary catheter incrustations. All patients had chronic indwelling catheters that required frequent changes because of severe incrustations and catheter occlusion. Incrustations were analyzed chemically for calcium, magnesium, ammonia nitrogen and phosphorus. The degree of incrustation before and during acetohydroxamic acid therapy was compared in each patient and was decreased significantly (average 81 per cent) during therapy (p less than 0.05). Catheter changes were required less frequently during therapy in all patients. Acetohydroxamic acid is effective in preventing catheter incrustations and should be considered in patients with this problem.

Catheters, Indwelling↗
PubMed1984

Dissolution kinetics of uric acid calculi.

Dissolution of uric acid calculi was studied in vitro. Calculated rate constants were then applied to an in vivo situation. The time required for complete dissolution of a uric acid calculus in a patient on oral alkali therapy can be estimated. Sodium bicarbonate, acetylcysteine, [tris(hydroxymethyl)aminomethane] and [tris(hydroxymethyl)aminomethane]-E were tested for relative effectiveness in dissolving uric acid calculi in vitro. In patients who require irrigation for dissolution of uric acid calculi [tris(hydroxymethyl)-aminomethane] is the preferred agent.

Acetylcysteine↗
PubMed1984

Calcium oxalate retention in subjects with crystalluria.

Calcium oxalate retention was studied in non-stone-forming volunteers. All subjects were placed on a constant diet for 5 days. After the oral administration of 10 microCi of [14C]-oxalic acid, the pattern of urinary oxalate excretion was followed for 48 h. Each subject was then given 10 microCi of [14C]-oxalic acid mixed with sufficient sodium oxalate (7.5 mg/kg body weight) to induce calcium oxalate crystalluria. Urinary oxalate excretion was then recorded for 48 h. After the administration of labeled oxalic acid (without additional sodium oxalate), 76.6 +/- 5.9% of the total recovered dose was excreted by 4 h. When the labeled oxalic acid was mixed with a sodium oxalate load, 62.4 +/- 8.8% was excreted by 4 h (p less than 0.01). Induction of calcium oxalate crystalluria results in the retention of oxalate in the kidney. The degree of retention varies among individuals. Differences in particle retention may help explain the differences between stone formers and non-stone formers.

Adult↗