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Biomedical subjects

U B Berg

Publications and source records attributed to U B Berg.

25 records · Page 2Linked to original sources
PubMed1991

Urinary protein excretion and renal function in children with IgA nephropathy.

Renal haemodynamics and the pattern of urinary protein excretion were studied in 38 children (21 boys, 17 girls) with biopsy-proven IgA nephropathy (IgAN), 0.4-16.8 (median 5.3) years after onset of the disease. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were evaluated by clearances of inulin and para-aminohippuric acid. Serum and urinary albumin, IgG and beta 2-microglobulin (beta 2 mu) were determined and the excretion rates, clearances, and fractional clearances were calculated. The patients were grouped according to the type and the amount of proteinuria. Mean GFR and ERPF were significantly decreased (107 +/- 3 and 580 +/- 17 ml/min per 1.73 m2, respectively) versus controls (119 +/- 2 and 627 +/- 14 ml/min per 1.73 m2, respectively). Grouped according to albumin excretion rates, non-albuminuric patients had normal GFR, while mean GFR was reduced in patients with micro-albuminuria (106 +/- 3 ml/min per 1.73 m2) and albuminuric patients (92 +/- 7 ml/min per 1.73 m2). IgG excretion increased with increasing albuminuria, but the selectivity index was lower in albuminuric patients than in patients with micro-albuminuria. Albuminuric patients had also higher blood pressure than those with micro-albuminuria. beta 2 mu excretion did not discriminate between patients with impaired renal function. The results suggest that childhood IgAN is not a benign kidney disease. After a median duration of 5 years of the disease a number of children had impaired renal function. Mean GFR was reduced most in the albuminuric patients but was also decreased in micro-albuminuric patients, indicating that micro-albuminuria may be a predictor of more severe disease.

Adolescent↗
PubMed1991

Long-term follow up of renal function in IgA nephropathy.

Fifty one children with IgA nephropathy verified at biopsy have been followed up clinically and functionally for 0.4-16.8 years from the onset of symptoms. Renal function was evaluated by determining the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) from the clearances of inulin and para-aminohippuric acid. Fifteen (29%) of the children had raised serum creatinine concentrations at the onset. Mean GFR was significantly lower than that of controls at the first investigation. During the follow up GFR and ERPF decreased and were significantly lower than in the controls after eight years of disease. The significant fall in renal function was found in children with proteinuria and especially in boys, in whom GFR and ERPF decreased from a mean (SEM) of 117 (5) and 616 (31) at 2.8 years to 97 (6) and 509 (36) ml/min/1.73 m2 at 7.5 years. Patients with raised serum creatinine concentrations at the onset had significantly lower GFRs, and patients with macroscopic haematuria at this time did not show decreased renal function at follow up. In conclusion, children with IgA nephropathy do not seem to have a benign clinical course. Boys with proteinuria show a significant decrease in renal function during follow up.

Adolescent↗
PubMed1991

Renal histological changes in relation to renal function and urinary protein excretion in IgA nephropathy.

Renal function and urinary protein excretion (UPE) were investigated at the time of kidney biopsy in 24 children with IgA nephropathy. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured by clearances of inulin and para-aminohippuric acid. For UPE albumin, IgG, beta 2 microglobulin, and creatinine were analysed. Glomerular global/segmental sclerosis and crescents in the biopsy specimens were assessed, and glomerular and tubulointerstitial changes classified on a five degree scale. The patients with tubulointerstitial or mesangial biopsy changes or glomerular sclerosis had significantly lower GFR than those without corresponding lesions. Patients with segmental sclerosis also had higher excretion rates of IgG, which increased with increasing segmental sclerosis. Six patients had GFRs below 2SD of the controls. Within the group of patients with reduced GFR overt albuminuria, a raised excretion rate of IgG, interstitial fibrosis, and advanced mesangial lesions were more frequent. A rising excretion rate of IgG seems to indicate both reduced GFR and increasing segmental glomerulosclerosis and may be a marker of progressive disease.

Adolescent↗
PubMed1989

Renal dysfunction in recurrent urinary tract infections in childhood.

One hundred children aged 1.5-19.5 years, with recurrent urinary tract infections, at least one of which was febrile (pyelonephritis, PN), were investigated by means of inulin and para-aminohippurate (PAH) clearance tests for the evaluation of glomerular filtration rate (GFR), effective renal plasma flow, and concentrating and diluting capacities. Renal function data were collated with the clinical history and radiological findings. GFR and PAH clearance were found to be reduced compared with controls. Patients whose first PN was diagnosed before the age of 3--particularly those with a history of three or more PN infections--showed the lowest values for GFR and PAH clearance. Furthermore, parenchymally reduced kidneys were found most frequently in this group of patients. Concentrating capacity was decreased in some patients, but a low concentrating capacity did not reveal patients with reduced GFRs. Diluting capacity evaluated as minimal urine osmolality was normal, but was reduced when evaluated as free water clearance in some patients with reduced values for GFR.

Adolescent↗
PubMed1984

Early renal functional changes in children with insulin-dependent diabetes mellitus--their relation to metabolic control.

This is the first part of a study dealing with the predicted effect of early renal function changes on later development of diabetic nephropathy. Renal function was studied by the clearance method in 128 children with insulin dependent diabetes mellitus after 0, 2, 5 and 10 years duration of the disease. The glomerular filtration rate (GFR) and filtration fraction were significantly increased after 0-5 years, but after 10 years the GFR did not differ from that of controls, which finding might indicate an earlier onset of diabetic nephropathy in children. Renal plasma flow did not differ significantly from that of controls. Increased fractional sodium excretion in cases of recent onset might indicate inadequate adaptation of the proximal tubules to the increased filtered load or to inadequate insulin therapy. An inverse correlation was found between GFR and metabolic control as evaluated clinically and by glucosylated haemoglobin concentration, i.e., poor metabolic control corresponded with high glomerular filtration rates.

Adolescent↗
PubMed1983

Age as a main determinant of renal functional damage in urinary tract infection.

Renal function was studied in 61 girls suffering from recurrent urinary tract infections, with at least one febrile infection. Clearance of inulin was determined. Intravenous urography and micturating cystourethrography were performed 1-6 months after the first infection and 0-6 months before or after the function test. A low glomerular filtration rate (GFR) was found only among children with their first pyelonephritis before the age of 3 years. A low GFR was found mostly in patients with small or scarred kidneys but was also seen in a few patients with normal intravenous urographs. Low GFR as well as radiologically small kidneys at the time of the function test were found independently of the presence or grade of vesicoureteral reflux at first infection. Patients with early onset pyelonephritis (before age 3 years) had a low capacity for early compensatory hypertrophy in contrast to patients with late onset pyelonephritis.

Adolescent↗