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Biomedical subjects

D A Diamond

Publications and source records attributed to D A Diamond.

At least 73 records · Page 4Linked to original sources

Duplex reflux: a study of 105 children.

A series of 105 children with vesicoureteral reflux into completely duplicated collecting systems was studied retrospectively. Of the children 64% were treated surgically, with two-thirds undergoing an ablative procedure and one-third undergoing common sheath ureteral reimplantation. The remaining 36% of the children were managed nonoperatively and followed for up to 11 years. Among these cases 89% of the kidneys had reflux into the lower pole moiety only and 11% had reflux into the upper and lower pole moieties. The spontaneous rates of reflux resolution were 85% for grades I and II, and 36% for grade III reflux during a median observation period of 40 months. These figures suggest that the spontaneous resolution of mild to moderate reflux into completely duplicated collecting systems is similar to that of identical degrees of single system reflux during a comparable observational period.

Abnormalities, Multiple↗

Ammonia levels in paediatric ureterosigmoidostomy patients: a screen for hyperammonaemia?

Hyperammonaemia in the urological patient is a rare and potentially grave condition. It has been reported most frequently in association with ureterosigmoidostomy, where clinical neurological symptoms have developed abruptly in association with markedly elevated plasma ammonia levels. The purpose of this study was to determine whether ureterosigmoidostomy patients might have subclinically elevated plasma ammonia levels, which would put them at risk of subsequently developing hyperammonaemic encephalopathy. Both urine and plasma ammonia levels were assayed in 10 asymptomatic paediatric urological patients with ureterosigmoidostomy. Ten paediatric colocystoplasty patients served as controls. Urine pH and urine ammonia levels were significantly higher in the ureterosigmoidostomy group. There was no significant difference in plasma ammonia levels between ureterosigmoidostomy and colocystoplasty patients. In none of the patients was the plasma ammonia level elevated, but 1 ureterosigmoidostomy patient had an exceedingly high urine ammonia level. It was concluded that an annual serum ammonia level in an asymptomatic ureterosigmoidostomy patient is probably not a valuable screen for subclinical hyperammonaemia.

Adolescent↗

Clinical patterns of paediatric urolithiasis.

A series of 270 paediatric stone patients was studied retrospectively according to the clinical pattern of urolithiasis (age and sex, stone location, stone analysis, recurrence rate) and aetiology of stone disease (infection, anatomical, metabolic or idiopathic). Infection stones occurred earliest and more commonly in males and were usually upper tract struvite calculi related to Proteus infection. Anatomical stones were most commonly associated with pelviureteric junction (PUJ) obstruction and had a high recurrence rate, despite surgical correction of obstruction. Idiopathic stones most resembled those found in adult urolithiasis by virtue of occurring latest, being sited in the ureter more often and being more frequently composed of calcium oxalate. Metabolic stones were most frequently calcium phosphate or cystine and virtually all were renal. They comprised the smallest group but had the highest recurrence rate.

Adolescent↗

Reversal of the toxic effects of cyclosporine on male reproduction and kidney function of rats by simultaneous administration of hCG + FSH.

We have shown earlier that the administration of cyclosporine impairs testicular function and causes a decrease in sperm counts, sperm motility and fertility. In order to determine whether or not the deleterious effects of CsA could be reversed by hormonal therapy, we injected sexually mature male Sprague Dawley rats with cremaphor + saline or CsA (40 mg./kg./d) alone or in combination with human chorionic gonadotropin (hCG; five micrograms./d/rat) and follicle stimulating hormone (FSH; five micrograms./d/rat). The injections were given subcutaneously for 14 days. As expected, CsA administration decreased the body and reproductive organ weights, testicular and epididymal sperm counts, sperm motility and fertilizing ability. Serum levels of LH were elevated and testosterone was decreased. The administration of FSH + hCG to the CsA treated rats restored the body and reproductive organ weights, sperm counts and motility. Seventy five percent of gonadotropin treated males were fertile as compared to 25% in the CsA treated group. In the hormone treated group, the blood levels of CsA were 50% of that of CsA treated group. In order to verify whether or not the decline in the blood levels of CsA was the cause for the amelioration of CsA-induced changes in the reproductive function, we compared the CsA + hormone treated group with another group treated with five mg./kg./d CsA which had blood levels of CsA comparable to the former group. In the five mg./kg./d group the reproductive functions were significantly lower than the CsA + hormone treated group suggesting, therefore, that the restoration of reproductive functions in the CsA + hormone treated group is a result of hormonal treatment. Administration of CsA (40 mg./kg./d) reduced the kidney weight and increased the levels of serum creatinine: these changes were also ameliorated by the administration of hCG + FSH.

Animals↗

Evaluation of the effect of experimental cyclosporine toxicity on male reproduction and renal function. Reversal by concomitant human chorionic gonadotropin administration.

Administration of cyclosporine to rats has been shown to impair testicular function, resulting in a decrease in sperm counts and fertility. In order to determine whether or not the deleterious effects of CsA could be reversed by hormonal therapy, mature male Sprague Dawley rats were treated with CsA (40 mg/kg/day, s.c.) alone or in combination with human chorionic gonadotropin (hCG) (5 micrograms/day/r; s.c.) for 14 days. Cyclosporine administration decreased the body weight (290 +/- 5.30 vs. 339 +/- 8.7 g; P less than 0.05) and reproductive organ weights (testis 1.49 +/- 0.42 vs. 1.60 +/- 0.03 g; epididymis 0.41 +/- 0.02 vs. 0.49 +/- 0.002 g; seminal vesicle 0.61 +/- 0.09 vs. 1.60 +/- 0.05 g; prostate 0.28 +/- 0.04 vs. 0.60 +/- 0.06 g; P less than 0.05) testicular sperm counts (5.80 +/- 0.42 vs. 8.49 +/- 0.48 x 10(7)/100 mg tissue; P less than 0.05) and epididymal sperm counts, (28.2 +/- 0.95 vs. 51 51.62 +/- 2.17 x 10(7)/100 mg tissue; P less than 0.05) and fertility (25% vs. 100%). Serum levels of LH were elevated (101.98 +/- 21.48 vs. 25.6 +/- 5.18 ng/ml; P less than 0.05) and testosterone was decreased (0.48 +/- 0.07 vs. 2.06 +/- 0.56 ng/ml; P less than 0.05). The administration of hCG to the CsA-treated rats restored the reproductive organ weights (testis 1.56 +/- 0.043 g; seminal vesicle 1.04 +/- 0.05 g; prostate 0.70 +/- 0.06 g) and sperm counts (testicular 7.88 +/- 1.0 x 10(7)/100 mg tissue; epididymal 59.86 +/- 4.16 x 10(7)/100 mg tissue; P less than 0.05) Serum levels of testosterone (18.63 +/- 4.45 ng/ml) and LH (431.65 +/- 31.41 ng/ml) were significantly elevated, as compared with control and CsA-treated groups (P less than 0.05). All the rats in the gonadotropin-treated group were fertile, as compared with 25% in the CsA-treated group. CsA reduced the kidney weight (1.17 +/- 0.02 vs. 1.27 +/- 0.03 g; P less than 0.05) and increased the levels of serum creatinine (0.97 +/- 0.07 vs. 0.59 +/- 0.03 mg/dl; P less than 0.05): these changes were ameliorated by the administration of hCG (kidney weight 1.35 +/- 0.03 g; creatinine 0.76 +/- 0.09 mg/dl).

Animals↗

Hyperammonemic encephalopathy: a complication associated with the prune belly syndrome.

Hyperammonemic encephalopathy in the urological patient is a rare but grave condition. In the pediatric urological population it has been associated with massively dilated upper tracts and urinary infection with urea-splitting organisms. We report 2 cases of hyperammonemic encephalopathy in association with the prune belly syndrome. Both patients presented comatose with markedly elevated serum ammonia levels and Proteus mirabilis urinary tract infection. Intravenous antibiotics and catheter drainage resulted in dramatic reversal of the encephalopathy. The pathophysiology of hyperammonemic encephalopathy in association with the prune belly syndrome and a review of the literature are presented.

Ammonia↗

Priorities in urinary diversion following pyeloplasty.

Debate continues regarding optimal drainage following pyeloplasty. We reviewed the method of drainage in 100 consecutive dismembered pyeloplasties performed from 1983 to 1987. Of the children 20 per cent underwent pyeloplasty with placement of a nephrostomy tube and transanastomotic stent (group 1), while 80 per cent underwent pyeloplasty performed in a nonintubated fashion (group 2). A urethral bladder catheter was used in 20 per cent of the patients in group 1 and in 90 per cent in group 2. While the over-all complication rates and long-term results were similar for both groups, the nature of complications for each group differed. The intubated group had a 10.5 per cent incidence of urinary tract infection, while the nonintubated group demonstrated an 8.6 per cent incidence of postoperative anastomotic leakage. A nephrostomy tube and stent appear to be unnecessary in the routine pyeloplasty and may prolong hospitalization. Selective use of upper tract drainage may help to decrease the incidence of postoperative leakage in specific cases.

Child↗

Etiological factors in pediatric stone recurrence.

We followed 270 pediatric stone patients during a 27-year period to determine the recurrence rate of stone disease. Stone disease recurred in 42 patients (16 per cent). When these patients were categorized according to etiology of the stone disease the recurrence rates were infection 14 per cent, idiopathic 14 per cent, anatomical 27 per cent and metabolic 30 per cent. The most prolonged interval to stone recurrence in each category ranged from 7 to 13 years and, thus, long-term followup of pediatric stone patients seems to be important.

Child↗

Neonatal bladder rupture: a complication of umbilical artery catheterization.

We report on 2 cases of neonatal bladder rupture that resulted from umbilical artery manipulation. This rare complication occurs because of the close proximity of the urachus to the umbilical arteries and peritoneal reflection, and results in urinary ascites and respiratory compromise. Among 11 neonates in the literature who experienced this complication the mortality rate was 18% but all 8 neonates who underwent surgical repair, including our 2 patients, survived.

Catheterization, Peripheral↗

Effect of cyclosporine A on male reproduction in rats.

We examined the effects of the immunosuppressive drug cyclosporine A on male reproduction in sexually mature rats. The drug was administered subcutaneously in 3 doses (10, 20 and 40 mg. per kg. daily) for 14 days. Cyclosporine A administration resulted in a dose-dependent decline in body and reproductive organ weights, histology of the testis showed definite degenerative changes, and sperm counts and motility decreased. Spermatozoa from treated rats retained the cytoplasmic droplet and they were decapitated. Consequently, sterility occurred in rats treated with high doses of cyclosporine A. A reduction in circulating testosterone and an increase in gonadotropins were noted. The possibility existed that the cyclosporine A-induced alterations in the male reproductive system were secondary to the hepatic or nephrotoxic effects of the drug. Therefore, we assessed liver and kidney function by assay of the serum levels of bilirubin, alkaline phosphatase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and creatinine. Except for an increase in bilirubin, none of the other liver function studies was altered, thereby eliminating hepatocellular damage as the etiology of impaired reproductive function in cyclosporine A-treated rats. We observed an increase in creatinine levels in animals treated with higher doses of cyclosporine A, consistent with mild renal failure. However, the fact that a decline in reproductive function was seen even in the group treated with 10 mg. per kg. cyclosporine A daily, which had normal serum creatinine levels, suggests that the alterations in male reproduction seen with this therapy are not entirely the result of nephrotoxicity.

Animals↗

Use of the anterior detrusor tube in managing urogenital sinus anomalies.

An anterior detrusor tube bladder neck reconstruction was performed in 8 girls with urogenital sinus anomalies during a 15-year period. A good or excellent result was achieved in 63 per cent of the patients. The surgical technique entails the creation of a long anteriorly based detrusor tube (6 to 7 cm.) tunneled subsymphyseal to the introitus, which provides access for clean intermittent catheterization. Augmentation cystoplasty, which was incorporated into the reconstruction in 1 case, may enhance further the success rates with this approach.

Adolescent↗

Aberrant epididymal tissue: a significant clinical entity.

Epididymal anomalies are relatively rare and usually they are associated with an undescended testis. A 33 to 66 per cent incidence of epididymal anomalies has been noted in male subjects with cryptorchidism. An increased incidence of epididymal anomalies also has been noted in association with cystic fibrosis, von Hippel-Lindau's syndrome and in male offspring of women treated with diethylstilbestrol. The frequency and anatomical spectrum of epididymal anomalies among men with normal descended testes are not known. We describe 3 patients with bilaterally descended testes, who were found to have aberrant epididymal tissue at scrotal or inguinal exploration. The variable presentations of aberrant epididymal tissue in these 3 patients can be explained best by understanding the embryology and anatomy of the epididymis and its associated vestigial structures. In all likelihood the structures encountered in our patients were the ductus aberrans inferior and the paradidymis. These structures, which rarely are included in urological anatomical descriptions of the epididymis, can be significant clinically. Therefore, it is important that the urologist be aware of their existence and their means of presentation.

Adolescent↗

Fogarty balloon catheter ablation of neonatal posterior urethral valves.

We describe a technique to ablate posterior urethral valves with a Fogarty balloon catheter. This technique has been used for 14 years in 10 cases with a good result in 9. Fogarty balloon catheter ablation of posterior urethral valves would seem to be particularly applicable to the small neonate with a vulnerable anterior urethra.

Catheterization↗

Incidental ganglioneuroblastoma.

A case is described in which an incidental ganglioneuroblastoma was discovered at the time of surgical correction of upper pole hydronephrosis secondary to an obstructing ectopic ureterocele in a duplicated system. We believe this is the first case of incidental ganglioneuroblastoma reported in the urologic literature. The management of this patient's disease is discussed as is the entity of incidental neuroblastoma.

Biopsy↗

Bladder neck reconstruction with omentum, silicone and augmentation cystoplasty--a preliminary report.

A new method of bladder neck reconstruction in which the Young-Dees tube was wrapped with omentum and silicone was used in 39 patients during a 20-month period. In 43 per cent of the patients simultaneous augmentation cystoplasty also was performed. The silicone was intended to maintain the Young-Dees tube length and to allow safe artificial sphincter cuff placement later when necessary. Among exstrophy patients 85 per cent of those who underwent augmentation and 15 per cent of those who did not are dry. A dry exstrophy patient had a remarkably easy sphincter cuff placement 6 months after bladder neck reconstruction. Of the epispadias patients 25 per cent are dry and 58 per cent have a dry interval of 2 hours or less. Erosion of silicone into the Young-Dees tube occurred in the first 5 patients in whom a thick (0.01-inch) wrap was used and in 14 per cent of those in whom a thin (0.005-inch) sheet was used. The details of this technique and modifications to reduce further the complication rate are discussed.

Adolescent↗