Faculty Bibliography

After 1 year of allopurinol treatment in 36 patients with a history of uric acid and/or calcium oxalate lithiasis and hyperuricosuria, we observed that in addition to the desired decreases in uric acid there were apparently significant decreases in urinary oxalate levels: 37 +/- 3 mg. per day (mean +/- standard error) before therapy and 31 +/- 4 mg. per day after a mean decrease of 16% (p less than 0.05) with an equivalent decrease in the supersaturation (calcium oxalate) of the urine. However, the decrease in oxalate could have been related to changes in dietary habits rather than to any specific effects of allopurinol on oxalate metabolism. Therefore, we recruited 26 of the patients for a study in which dietary factors were controlled. Each participant was assigned to 1 of 3 diet groups: low or high protein, or a customary diet. Each patient collected a urine specimen while on allopurinol and again after the medication was discontinued. With analytical procedures that we ascertained to be free of any significant methodological bias, we observed no significant changes in urinary oxalate excretion that could be attributed to allopurinol. There were significant differences in oxalate excretion on versus off allopurinol between the low and high protein groups, with higher oxalate levels found for the latter group. Our results indicate that allopurinol does not have a specific effect on oxalate metabolism or oxaluria.

The cry of "ESWL for all" was heard at the 84th Annual Meeting of the American Urological Association, and actually, this is not far from the truth. Those physicians who are not familiar with percutaneous techniques, or who do not have the necessary equipment available, may actually attempt ESWL for all calculi regardless of stone burden or location. Patients who are interested in avoiding manipulation may request ESWL, even if the results may not be as good as those obtained with concomitant manipulation or with percutaneous procedures. Nevertheless, indications still exist for percutaneous techniques, and these procedures will not become obsolete even as ESWL technology advances. Studies are being conducted to identify the ideal treatment for all varieties of stones in the genitourinary system. As ESWL and endoscopic technology continue to advance, the treatment of stone disease will continue to change.

Advanced age should not be a contraindication to the evaluation of a geriatric patient who presents with bladder dysfunction after a cerebrovascular accident. A team approach consisting of the geriatrician and the urologist is beneficial to the care of the patient. Once a problem has been identified, the pathophysiology can be worked out and a rational approach can be formulated for the patient. A return to continence in most patients is possible with a combination of medical and surgical treatment.

Lysozyme in the urine in concentrations greater than 3 micrograms per milligram of creatinine reflects renal tubular disease or dysfunction in patients without bowel disease or leukemia. We therefore used urine lysozyme assays to assess renal response to percutaneous nephrostomy and stone removal in 42 patients. Eight patients had striking increases (4.2-21.1 [mean 7.58] micrograms/mg creatinine) immediately after nephrostomy puncture in urine obtained directly from the punctured kidney. Lysozyme declined sharply thereafter and was within normal limits in all cases by postoperative day 3. This increase appeared to result from bleeding into the urine from the tract. Five other patients had lysozymuria on admission, only 1 of whom had a sharp increase after nephrostomy puncture. In the remaining patients, the lysozyme levels remained within normal limits throughout the hospital course. These data are further evidence of the absence of significant deleterious effects of nephrostomy puncture on the kidney.

Ureteral anatomy is vital to the endoscopist as this knowledge will facilitate the endoscopic manipulation of the ureter and minimize the morbidity that can be associated with these procedures.

A total of 12 patients with absorptive hypercalciuria type II and 11 normal controls participated in a study to evaluate the effects of dietary protein levels on urinary calcium and oxalate excretion before and after a 1 gm. dose of oxalate. Two test periods were used during which calcium (less than 400 mg. per day) and oxalate were restricted. The first test was done under conditions of low dietary protein (12 per cent total caloric intake, 60 gm.) and the second test was done at a high protein level (25 per cent, 125 gm. protein). Twelve-hour urine specimens were obtained after dinner on day 3 of each diet (low and high protein) and again on day 4 when 1 gm. oxalate (spinach) was added to the dinner meal. The specimens were analyzed for calcium, oxalate and relative calcium oxalate saturation (concentration product ratio). There were no significant differences between the controls and subjects with absorptive hypercalciuria type II in oxalate excretion before the oxalate load on the low protein (controls 31.4 +/- 4.2 standard error, expressed as mmol. oxalate per mol. creatinine, and absorptive hypercalciuria type II 23.1 +/- 3.1) and high protein (controls 30.4 +/- 4.2 and absorptive hypercalciuria type II 28.8 +/- 5.9) diets. After the oxalate bolus the positive changes in oxalate excretion were 11.8 +/- 4.8 (low protein) and 17.8 +/- 4.7 (high protein) for controls, and 11.4 +/- 4.4 (low protein) and 31.8 +/- 5.2 (high protein) for patients with absorptive hypercalciuria type II. Thus, the increases in post-load urinary oxalate levels observed for controls and patients were greater on the high protein than on the low protein diets. After the oxalate load the increases in urinary oxalate and calcium oxalate supersaturation were significantly greater for patients with absorptive hypercalciuria type II than for control subjects for the high protein but not the low protein diets (p less than 0.05).