Oswaldo Luiz Ramos

Urolithiasis in childhood : metabolic evaluation

In order to determine metabolic disorders in children with urolithiasis, 50 patients with urinary calculi were studied. Abdominal pain and/or haematuria were the most predominant symptoms. Surgical procedures were required in 22% of these children and urinary tract infection was observed in 34% of this group. Only 2 children had anatomical malformations of the urinary tract. Absorptive hypercalciuria (32%), renal hypercalciuria (34%) and uric acid hyperexcretion (24%) were the most common metabolic abnormalities in these children. We were unable to find an underlying metabolic abnormality in only 14% of the patients. These data suggest that appropriate metabolic study will allow rational management of children with urinary stones.

Kidney transplantation from living unrelated donors.

OBJECTIVE To compare patient and graft survival of recipients of kidneys from living, unrelated donors (LUDs); cadaveric donors; and living, related donors (LRDs) matched for zero (mismatched), one, or two (identical) haplotypes. DESIGN Cohort study. SETTING Sixty-three renal transplantation centers affiliated with the Brazilian Transplantation Registry (accounting for more than 95% of the transplantation activity in Brazil). PATIENTS Patients having renal transplantation between January 1987 and March 1991. Of 2892 patients, 165 (6%) received transplants from LUDs; 964 (33%), from cadaveric donors; 183 (6%), from zero haplotype, HLA-matched LRDs; 1259 (44%), from one haplotype-matched LRDs; and 321 (11%), from two haplotype-matched LRDs. MEASUREMENTS Patient and graft survival. Patients were followed for an average of 15.8 months. RESULTS After adjustment for age, race, diagnosis of primary disease, history of previous transplantation, cyclosporine use, and number of transplants from LUDs per center, patient survival did not differ statistically for recipients of kidneys from LUDs and recipients of cadaveric kidneys (risk ratio [RR], 1.16; 95% Cl, 0.68 to 1.98). Little difference was seen between the adjusted death rate for recipients of zero haplotype-matched LRDs and recipients of cadaveric kidneys (RR, 1.13; Cl, 0.69 to 1.87). Similarly, in a multivariate analysis, recipients of kidneys taken from LUDs and zero haplotype-matched LRDs had a risk for graft failure that did not differ statistically from that of cadaveric kidney recipients (RR, 0.74; Cl, 0.45 to 1.22 and RR, 0.82; Cl, 0.53 to 1.25, respectively). CONCLUSIONS Graft survival for recipients of kidneys from LUDs is similar to that from zero haplotype-matched LRDs and is at least as good as that achieved with cadaveric transplants.

Cost-Effectiveness Analysis of the Treatment of End-Stage Renal Disease in Brazil

Cost-effectiveness analysis compared four treatments of end-stage renal disease in Brazil: continuous ambulatory peritoneal dialysis (CAPD), in-center hemodialysis (HD), cadaver donor transplantation (CD-Tx), and living related donor transplantation (LR-Tx). After 2 years, the costs per year of survival were CAPD,

Prediction of steroid responsiveness in the idiopathic nephrotic syndrome using urinary retinol-binding protein and beta-2-microglobulin

12,134; HD,

Role of Substance P in Blood Pressure Regulation in Salt-Dependent Experimental Hypertension

10,065; CD-Tx,

Renal Accumulation of 99mTC-Dmsa in the Artificially Perfused Isolated Rat Kidney

6,978; and LR-Tx,

The Renin-Angiotensin System in the Control of Systemic Arterial Pressure

3,022. The HD cost was lower than CAPD partially because of the reuse of hemodialyzers in Brazil. Although less cost-effective, both dialysis treatments yielded more years of survival after 2 years. This analysis reveals a trade-off between cost per year of survival and years of survival.

Acute hemodynamic and humoral effects of metoclopramide on blood pressure control improvement in subjects with diabetic orthostatic hypotension

OBJECTIVES To determine the prevalence of early proximal tubular dysfunction, measured by urinary excretion of retinol-binding protein (RBP) and beta-2-microglobulin (B2M), in patients with the idiopathic nephrotic syndrome and to investigate the value of these tests in predicting steroid responsiveness. DESIGN Before-after trial with 8-week treatment period. SETTING Tertiary referral center. PATIENTS Sequential sample of 37 patients with the idiopathic nephrotic syndrome caused by minimal change disease, focal segmental glomerulosclerosis, or mesangial proliferative glomerulonephritis. INTERVENTION All patients were treated with prednisone as one dose of 1 to 1.5 mg/kg body weight per day for 8 weeks. MEASUREMENTS Urinary RBP was measured by an immunoenzymometric assay and B2M, by an enzyme-linked immunosorbent assay. Remission of the nephrotic syndrome after steroid treatment was the main outcome variable. RESULTS Elevated levels of urinary RBP and B2M before treatment were detected in 65% and 75% of the patients, respectively. Median urinary RBP and B2M, before treatment, were significantly higher in the steroid-unresponsive group than in the responsive group (P less than 0.01). In the steroid-responsive group, urinary RBP and B2M levels decreased significantly after remission (P less than 0.01). In the steroid-unresponsive group, the likelihood ratios for urinary RBP greater than 4000 micrograms/g creatinine and for B2M greater than 3000 micrograms/g creatinine were 3.8 and 3.0, respectively. The probability was 100% that values of RBP of less than 1300 micrograms/g creatinine and B2M of less than 130 micrograms/g creatinine were from steroid-responsive patients. Multivariate analysis confirmed that higher urinary levels of RBP and B2M were associated with a lower likelihood of steroid responsiveness, independent of age and histologic diagnosis. CONCLUSIONS Proximal tubular dysfunction is frequent in patients with the idiopathic nephrotic syndrome. Pretreatment urinary RBP and B2M levels may be helpful in identifying nephrotic patients who are more likely to be responsive to steroids.

Etiopathogenesis of Excess Methylprednisolone Arterial Hypertension in the Rat

The participation of substance P in the pathogenesis of five models of experimental hypertension, ie, DOCA-salt, subtotal nephrectomy, one-kidney-one clip renovascular, two-kidney-one clip renovascular, and spontaneous hypertension, was evaluated via an acute infusion of a newly synthesized potent, specific nonpeptide antagonist of substance P at the NK-1 receptor, the agent CP 96,345. In conscious unrestrained rats, CP 96,345 induced significant and sustained increases in mean arterial pressure of DOCA-salt, subtotal nephrectomy, and one-kidney-one clip renovascular hypertensive rats but only small and nonsignificant changes in blood pressure of two-kidney-one clip renovascular and spontaneously hypertensive rats. CP 96,345 had no effect on the blood pressure of sham-treated controls and Wistar-Kyoto rats. This NK-1 receptor antagonist did not significantly affect the heart rate of any experimental model studied. The data suggest that endogenous substance P may act as a partial counterregulatory mechanism against vasoconstriction in models of salt-dependent hypertension.

Intima-media thickness evaluation by B-mode ultrasound: Correlation with blood pressure levels and cardiac structures

In order to investigate aspects of the renal handling of 99mTc-DMSA, 68 isolated rat kidneys were artificially perfused. The experimental groups were: Group 1 (no. = 32)-oxygenated filtering kidneys; Group 2 (no. = 29)-oxygenated non-filtering kidneys; Group 3 (no. = 7)-anaerobic non-filtering kidneys. We conclude that the 99mTc-DMSA complex is strongly bound to albumin, is not filtered and is removed from perfusion fluid through the renal peritubular capillary route and that this occurs by an active process which depends upon aerobic metabolism. This process has a high capacity and is not inhibited by probenecid.