Pediatric urolithiasis in Armenia: a study of 198 patients observed from 1991 to 1999

To study prospectively the risk factors and etiology of urolithiasis in all stone patients aged <15 years admitted from 1991 to 1999 to the Arabkir hospital in Yerevan. Stones were obtained by surgery (64%), extracorporeal shockwave lithotripsy (ESWL) (7%) or cystoscopic extraction (4%); 25% passed spontaneously. All were examined by infrared spectroscopy, and spot urines were analyzed chemically. 198 patients, 180 (68% males) with renal stones and 18 (83% males) with primary bladder stones, were studied. Calcium oxalate (CaOx) was the predominant constituent in 62% of the kidney stones, followed by struvite (17%), calcium phosphate (7%), uric acid (7%), ammonium acid urate (5%), and cystine (2%). Bladder stones contained CaOx in 72%, uric acid in 22% and ammonium acid urate in 6% of patients. Etiology was obviously metabolic in 5% and possibly metabolic in 26%. Twenty percent of stones were infectious, and 19% were endemic (9% bladder and 10% kidney stones); 4% were secondary to urinary stasis with malformation but no infection. Etiology in 26% remained unknown. Stone composition and metabolic etiology are similar to that in central Europe and North America. In contrast, infectious calculi and particularly endemic stones are still common, although becoming less so now. Urolithiasis in Armenia thus reflects the transition from a rural to an urban society.

An epidemic of acute postinfectious glomerulonephritis in Armenia

AIM

To evaluate the presentation and course of acute postinfectious glomerulonephritis (APGN), which has increased dramatically in Armenia after serious deterioration in the living conditions.

STUDY DESIGN

Observational study, based on case notes, of a large homogeneous group of patients hospitalised for APGN at one centre over a five year period (1992-6).

PATIENTS

474 patients aged < 16 years with a diagnosis of APGN.

RESULTS

The annual number of patients increased tenfold from 19 (average 1992/3) to 196 in 1995. Sixty two per cent were in the age group 4-9 years and 65% were boys. Upper respiratory infections, scarlet fever, and skin infections preceded APGN in 51%, 23%, and 13%, respectively. All patients had haematuria (93% gross), 84% had oedema, and 72% had hypertension. C3 was initially decreased in 95% of the patients examined. Renal function was impaired (serum creatinine > 100 mumol/l) in 29%. Four patients with renal failure had crescentic glomerulonephritis at biopsy; of these, three required temporary haemodialysis. Main extrarenal complications were heart failure (10%) and convulsions (3%). One patient died and five (3%) did not recover completely.

CONCLUSIONS

APGN in children is associated with considerable initial morbidity, and long term outcome is not uniformly benign. Outbreaks of APGN may occur anytime in countries such as Armenia that are suffering from a sudden decline in socioeconomic conditions.

From dialysis to basic paediatric nephrology: an unorthodox project applied in Yerevan, Armenia

Following the earthquake in December 1988, a long-term project was developed: starting from haemodialysis, it was extended to basic nephrology and urology, with a programme for schooling and psychosocial care. Medical training had first priority. The programme relied on robust and often second-hand equipment and voluntary work. The approach chosen (an inverse help programme, from sophisticated to basic medicine) strongly stimulated motivation and proved to be practicable.

Urinary and biliary excretion of aluminoxamine and ferrioxamine in dogs with various renal function

We assessed the pharmacokinetics of aluminoxamine and ferrioxamine in dogs with sustained intermittent bile duct ligation and either normal renal function or stable chronic renal failure. A first group of male beagle dogs were given aluminoxamine and ferrioxamine, while a second group received desferrioxamine after loading them with iron and aluminum. Only minute amounts of ferrioxamine and aluminoxamine were found in the bile after administration of these compounds. The distribution volume of aluminoxamine and ferrioxamine appeared to be confined to the extracellular space and their renal excretion correlated with renal function. Administration of desferrioxamine to iron and aluminum-loaded dogs resulted in an increased biliary ferrioxamine but negligible aluminoxamine excretion. Renal clearance of the in vivo formed ferrioxamine and aluminoxamine in this group strongly correlated with renal function. Our observations indicate that biliary excretion of intravenously administered ferrioxamine and aluminoxamine is negligible even in renal failure. The data presented in this study provide indirect evidence that desferrioxamine administration to iron- and aluminum-loaded dogs results in the intra-hepatic formation of ferrioxamine which is partly excreted in the bile. Biliary excretion of aluminoxamine after desferrioxamine administration remained negligible.

A standardized surgical technique to obtain a stable and reproducible chronic renal failure model in dogs

The remnant kidney, a model of chronic renal failure in animals, can be obtained by two techniques: either surgical removal of tissue of one kidney, combined with contralateral nephrectomy or inducing necrosis of kidney tissue by ligation of branches of the renal artery of one kidney combined with contralateral nephrectomy. In the literature, most reports concern the ligation technique. The technique is safe and simple but the results in dogs are unpredictable. In this paper, both techniques were compared. We could demonstrate that the unpredictable result of the ligation technique is due to the formation of collateral vessels bypassing the ligated branches and to the inconstant ramification pattern of the renal artery. In this study, a standardized technique consisting of the resection of 16-18 g of tissue of one beagle kidney and removal of the other one is described. This method results in a stable chronic renal failure until the dogs are sacrificed at 9-12 months.