Demonstration of an antibody to tubular epithelium in glomerulonephritis associated with obstructive uropathy.

It has been postulated that in some patients with obstructive and reflux uropathy proteinuria develops through an intermediate mechanism of immune complex glomerulonephritis involving antigenic material of renal tubular epithelium. A patient with a unilateral ureterocele and nephrotic syndrome underwent bilateral renal biopsies during surgical correction of the obstruction. The obstructed kidney showed mild pyelonephritis, but both kidneys showed a glomerulopathy with electron-dense deposits in the mesangial and paramesangial regions associated with positive immunofluorescence for immunoglobulin M (IgM) and the third component of complement (C3). An IgM antibody was eluted from the biopsy specimens and it reacted by indirect immunofluorescence with normal renal tubular epithelium and with the patient's renal tubular epithelium. The eluate also reacted with pre-eluted glomeruli of the patient, but not with normal glomeruli. All antibody activity could be removed from the eluate by pre-incubation with normal kidney. It is concluded that the unilateral renal obstruction produced tubular injury so that as yet unidentified antigens were recognized by the immune system. The resultant antibody response gave rise to circulating immune complexes which were then deposited in glomeruli with subsequent glomerular damage and nephrotic syndrome.

The ultrastructure of neurilemoma with emphasis on Antoni B tissue.

Ten neurilemomas were studied by electron microscopy. Antoni A and B tissues were identified by light microscopy on semithin sections, and the corresponding areas on adjacent ultrathin sections were studied ultrastructurally. The Antoni B tissue definitely possessed features of degeneration in that the cells showed a detached basal lamina, a disrupted cell membrane, degenerated nuclei, and a significant accumulation of cytoplasmic granules and myelin figures. Added to these was intercellular edema with fibrin. The similarity of the granules in the cells of Antoni B tissue, cells of granular cell tumor, and Schwann cells in wallerian degeneration supports the conclusion that these three are related phenomena.

The color of the skin of the palms and soles as a possible clue to the pathogenesis of acral-lentiginous melanoma.

It is obvious clinically that skin of the palms and soles (volar skin) of blacks is lighter in color than black glabrous skin. The same difference obtains in whites, but is much less obvious. The distribution of melanosomes within keratinocytes of the palms and thighs of blacks and whites was compared. Keratinocytes in skin from the thighs of blacks contained only individually dispersed melanosomes, but keratinocytes in skin from the palms of blacks and from the palms and thighs of whites contained complexed melanosomes. Our observation may explain why the incidence of melanoma of volar skin in blacks and whites is similar, whereas melanoma on the glabrous skin of blacks is extremely rare.

Comparison of autologous fat transfer in fresh, refrigerated, and frozen specimens: an animal model.

The rising popularity of autologous fat transfer (AFT) has raised the questions whether cryopreserved adipocytes are a suitable substrate for soft-tissue augmentation, and which storage techniques may be most suitable for a maximally successful surgical result. An animal model of AFT was conceived using isogeneic Sprague-Dawley rats. Suction harvesting of fat and subcutaneous implantation was performed with specimens stored at -16 degrees C or 1 degrees C for a period of 1 or 2 weeks, as well as a group that underwent immediate implantation. A histological comparison of the experimental and control groups clearly demonstrated a decrease in viable adipocytes and an increase in signs of inflammation and fat cell necrosis in those animals that received stored fat instead of immediate fat implantation. These changes became more severe with increased length of storage and the use of refrigeration over freezing. The authors conclude that the practice of storing harvested adipocytes for later injection is not supported by the experimental evidence and should be avoided.

Brachiola vesicularum, n. g., n. sp., a new microsporidium associated with AIDS and myositis.

Brachiola vesicularum, n. g., n. sp., is a new microsporidum associated with AIDS and myositis. Biopsied muscle tissue, examined by light and electron microscopy, revealed the presence of organisms developing in direct contact with muscle cell cytoplasm and fibers. No other tissue types were infected. All parasite stages contain diplokaryotic nuclei and all cell division is by binary fission. Sporogony is disporoblastic, producing 2.9 x 2 microns diplokaryotic spores containing 8-10 coils of the polar filament arranged in one to three rows, usually two. Additionally, this microsporidium produces electron-dense extracellular secretions and vesiculotubular appendages similar to Nosema algerae. However, the production of protoplasmic extensions which may branch and terminate in extensive vesiculotubular structures is unique to this parasite. Additionally, unlike Nosema algerae, its development occurred at warm blooded host temperature (37-38 degrees C) and unlike Nosema connori, which disseminates to all tissue types, B. vesicularum infected only muscle cells. Thus, a new genus and species is proposed. Because of the similarities with the genus Nosema, this new genus is placed in the family Nosematidae. Successful clearing of this infection (both clinically and histologically) resulted from treatment with albendazole and itraconozole.