Analysis of ultrastructural glomerular basement membrane lesions and podocytes associated with proteinuria and sclerosis in Osborne-Mendel rats with progressive glomerulonephropathy

The renal glomeruli of 12 male Osborne-Mendel (OM) rats 3 to 24 weeks old were examined by electron microscopy. Effacement of podocyte foot processes (FPs) developed at 3 weeks of age and became progressively worse over time. Loss or dislocation of the slit membrane was also found. Vacuoles and osmiophilic lysosomes appeared in the podocytes starting at 6 weeks of age. Podocyte detachment from the glomerular basement membrane (GBM) was apparent at 18 weeks of age. Laminated GBM was occasionally observed in all animals. These features might lead to the development of spontaneous proteinuria and glomerulosclerosis in OM rats.

Congenital syphilitic nephrosis.

Analysis of congenital syphilis in 455 infants and neonates between 1977-1991 in Children's Hospital, Bangkok, Thailand revealed 11 cases (2.4%) with evidence of congenital syphilitic nephrotic syndrome which were confirmed by clinical, serologic and laboratory findings, long bone x-rays and renal biopsy. Ages of all 11 cases were between 1 day to 2 months (mean 24 days); 6 were boys and 5 girls. Two of them died because of necrotizing enterocolitis and sepsis respectively; the mortality rate was 18%. The other nine had complete recovery following penicillin therapy.