Peritubular capillary flow determines tubulointerstitial disease in idiopathic nephrotic syndrome.

The spatial relationship between renal perfusion and nephronal structure was determined in 51 nephrotic patients consisting of 11 patients with steroid sensitive, minimal change (MC) nephrosis, 12 patients with steroid resistant, mesangial proliferative (MesP) nephrosis and without tubulointerstitial fibrosis (TIF), 11 patients with steroid resistant, MesP nephrosis and with low grade TIF and 17 patients with focal segmental glomerulosclerosis (FSGS). The intrarenal hemodynamic study revealed a unique correlation between renal perfusion and nephronal structure. A normal or slight reduction in peritubular capillary flow observed in MC or mild MesP nephrosis correlates with an intact tubulointerstitial structure.

Renal perfusion and disease progression.

The pathogenetic concept of renal hyperperfusion and hyperfiltration in inducing glomerular pathology and disease progression documented in the renal ablation model in experimental animals to mimic renal disease with reduced nephron mass has recently been challenged. In contrast to the above, the intrarenal hemodynamic study in a variety of chronic glomerulonephropathies reveals a unique characteristic of renal hypoperfusion rather than hyperperfusion. This is associated with an elevated renal arteriolar resistance and reductions in renal plasma flow and peritubular capillary blood flow.

Tubular function and tubulointerstitial disease.

Tubular transport determined by the fractional excretion (FE) of filtered solutes was studied in 129 nephrotic patients; 72 patients with mesangial proliferation (MesP-NS) and intact tubulointerstitium (group 1), 13 patients with MesP-NS and superimposed tubulointerstitial fibrosis (TIF; group 2), 27 patients with mild focal segmental glomerulosclerosis (FSGS; group 3), and 17 patients with severe FSGS (group 4). In the 72 nephrotic patients with MesP-NS and normal tubulointerstitium (no TIF), tubular transport was intact (FE of sodium [FENa], 0.5 +/- 0.

Glomerular endothelial dysfunction determines disease progression: a hypothesis.

A glomerular endothelial function with its hemodynamic impact is proposed to determine disease progression. In the clinical settings associated with an intact endothelial function, such as minimal-change steroid-sensitive nephrosis, the early phase of diabetes mellitus and the early stage of an experimental model of renal ablation in animals, it was observed that adequate renal perfusion correlates with the intact structure and function of the nephron with no evidence of disease progression. In contrast, the clinical settings associated with endothelial dysfunction, such as chronic glomerulonephropathy, the late stage of diabetes mellitus and a renal ablation model in animals, are usually associated with a reduction in renal perfusion.

Renal dysfunction in glomerulonephropathy associated with rapid onset renal failure.

Eight patients between the ages of 5 and 26 years developed a rapid decline of renal function with a period of oliguria or anuria which ranged between 1 and 21 days. The initial assessment of renal function revealed a severe degree of glomerular, tubular, and vascular abnormalities. The magnitude of the renal dysfunction was quantified and expressed in terms of a clinical score.

Renal dysfunctions in glomerulonephropathy with rapidly declined renal failure.

Eight patients aged between 5 and 26 years developed rapid deterioration of renal function and became oliguric/anuric with duration ranging from 1 to 21 days. The initial functional assessment revealed severe degree of glomerular, tubular, and vascular dysfunctions. The magnitude of renal dysfunction was quantified and expressed in terms of a clinical score.

Intrarenal hemodynamic abnormality in severe form of glomerulonephritis: therapeutic benefit with vasodilators.

Intrarenal hemodynamic and tubular function has been assessed in 16 patients who presented clinically with hypertension, hematuria and severe renal functional impairment. Twelve of these 16 patients had histopathologic classification as DPGN (3 cases), MPGN (3 cases) and FSGS (6 cases). The initial assessment of intrarenal hemodynamics in 11 patients revealed strikingly increased afferent (RA) and efferent arterioles (RE), filtration fraction (FF), intraglomerular capillary hydrostatic pressure (PG), whereas, there was marked reduction in renal plasma flow (RPF), in ultrafiltration coefficient (KFG) and in glomerular filtration rate (GFR).

Diagnostic study of urinary frequency in children.

A urologic study of 28 patients (11 males and 17 females, 4 to 14 years old) revealed that 23 patients (83%) had organic disease, 20 of whom had lower urinary tract abnormalities. Of 22 patients who were assessed psychologically, 14 had difficulty in adaptation, 20 had special birth order problems, and in 14 onset of symptoms occurred before school age. After five years of follow-up, 18 of 20 patients who were re-evaluated had no recurrent urinary frequency symptoms.

Neonatal lead poisoning. An unusual clinical manifestation.

A case of lead encephalopathy in a 2-month-old child is reported. Modes of poisoning are discussed and the unusual clinical manifestations of metallic brownish discoloration of nails and subdural effusion are presented. The possibility of lead poisoning as a cause of convulsions in neonates should be considered by doctors caring for these patients.