Structural and ultrastructural changes in the developmental process of premature infants' and children's corneas.

Seven corneas ranging in age from 20 weeks of gestation to 6 months after birth were studied and changes observed in five layers. The epithelium thickens through the addition of new cellular layers and the enlargement of cells. The way junctional complexes develop with age is described. The way the collagen fibrils in Bowman's layer is arranged changes over time. The layer arrangement and orientation of the stroma's collagen fibrils are described at different stages of development. The keratocytes progressively flatten out and gather together. The thickness of Descemet's membrane increases from 0.6 m at 20 weeks of gestation to 4 m at 6 months. During the prenatal period, the banded layer appears with cross-linking bridges. The nonbanded layer appears after birth. Several changes were found in the endothelium: flattening out of the initially cube-shaped cells and changes in the intercellular junctions that can be seen from 20 weeks of fetal life. At 20 and 25 weeks of gestation, two layers of cells were observed in the corneal midperiphery. The adult structure of the cornea was reached at about 6 months after birth.

Sustained effect of angiotensin II on tyrosine phosphorylation of annexin I in glomerular mesangial cells.

By means of selective extraction in a Ca(2+)-chelating medium and immunoblotting, four annexins (I, II, V, and VI) were identified in both isolated rat renal glomeruli and rat glomerular mesangial cells. Upon 32P labeling of these cells in culture, annexin I was immunoprecipitated using a specific polyclonal antibody and was found to incorporate radioactivity in a constitutive manner. However, as with epidermal growth factor (200 ng/ml), addition of angiotensin II (10(-7) M), arginine-vasopressin (10(-7) M), or endothelin I (10(-7) M) resulted in a 2-3-fold stimulation of annexin I phosphorylation. The basal phosphorylation as well as the stimulating effect of angiotensin II were also detected by immunoblotting annexin extracts using an antiphosphotyrosine antibody. In addition, among various phosphotyrosyl proteins isolated from EGTA extracts by adsorption onto an anti-phosphotyrosine antibody, annexin I was specifically recognized by Western blotting using a monoclonal anti-annexin I antibody, and displayed the same increase upon cell stimulation with angiotensin II. Moreover, thin layer chromatographic analysis of phosphoamino acids present in immunoprecipitated [32P]annexin I showed an exclusive labeling of phosphotyrosine residue(s). Finally, the effect of angiotensin II was detectable after 10 min, maximal at 6 h, and present until 12 h of incubation. Using 12-h stimulation, tyrosine phosphorylation of annexin I displayed a maximum at 10(-7) to 10(-6) M angiotensin II. These data report for the first time the stimulation of annexin I tyrosine phosphorylation by biologically active peptides acting via receptors belonging to the superfamily of seven hydrophobic domain, G-protein-linked receptors, which lack an intrinsic protein tyrosine kinase. This suggests a possible role of annexin I in the mitogenic effect of angiotensin II, arginine-vasopressin, and endothelin I, which was previously observed on rat glomerular mesangial cells as well as on other cells.

[Renal hemosiderosis caused by chronic hemolysis in a patient with a Saint-Jude mitral valve prosthesis]. / Hémosidérose rénale par hémolyse chronique sur valve de Saint-Jude en position mitrale.

The authors report a case of renal hemosiderosis in a 33 year old patient with mitral valve replacement with a Saint Jude Medical prosthesis. Chronic, well-tolerated hemolysis developed after surgery and a peri-prosthetic leak was demonstrated. Alteration of renal function and abnormalities on urinalysis led to renal biopsy which showed massive localised hemosiderosis, mainly in the interstitial tissues. Repeat mitral valve replacement led to a regression of the hemolysis. Significant hemolysis in patients with mechanical cardiac valves prostheses should lead to investigation of prosthetic valve function and, if dysfunction is demonstrated, the patient should be considered for reoperation because of the potential severity of renal complications.

Chronical administration of anti-DNA antibodies by subcutaneous injection of hybridoma clones in BALB/c and NZBxNZW/F1 mice. Experimental model of the pathogenic role of DNA in acute lupus disease.

Several sets of data suggest that specific classes of anti-DNA antibodies could be implicated in the genesis of glomerular lesions in SLE. The goal of this work is to investigate if this pathogenic role could be related to the antibodies' genetic origin--from BALB/c or NZBxNZW/F1 mice--or to their physiological origin--induced either by DNA or by polyclonal B cell activation in normal mice. For this purpose, anti-DNA antibody hybridoma clones produced from different origins were subcutaneously injected in BALB/c or NZBxNZW/F1 female mice, followed by studies of immunological parameters and kidney lesions. Results concur that the induced anti-DNA antibodies can play a role in fatal disease development, related to clonal specificity but not to the way of stimulation which was either polyclonal B cell activation or DNA immunization. Also, they emphasize the possible very lethal role of serum circulating DNA.

The spontaneous development of immune complex type glomerular lesions in outbred mice is dependent on environmental factors and sex.

To investigate the role of environmental factors in the spontaneous development of immune complex glomerulonephritis in the mouse, follow-up studies of various immunological parameters and of kidney lesions have been done in male and female outbred OF1 mice housed from birth to four months of age in two different conditions: (a) in a conventional animal house; (b) in a "controlled" animal house designed for long-term studies on nude mice. Female mice housed under conventional conditions develop mild to intense glomerular lesions with granular deposits of immunoglobulins and C3 after two months of age. The appearance of these lesions is correlated with a sharp increase of various IgG subclasses levels at two months of age. Female mice housed under "controlled" conditions do not show such an increase and have only scarce to mild lesions until four months of age. In male mice, similar observations are done but the differences in immunological parameters and in histopathological findings between the two groups of mice according to the housing conditions are less noticeable. The environmental factors which are involved in the development of these immune mediated lesions are not known; it is hypothetized that infectious agents play a role. This study emphasizes the importance of housing conditions and of sex in immunopathological investigations in the mouse and the possible bias these conditions may introduce, in some experiments.

Rapidly progressive glomerulonephritis associated with amyloidosis: efficacy of plasma exchange.

This report describes one case of rapidly progressive glomerulonephritis associated with amyloidosis in a 53-year-old woman with rheumatoid arthritis, successfully treated with intensive plasma exchange and immunosuppression. Amyloid deposits were present in all of 20 glomeruli in the kidney biopsy specimen and eight out of nine nonfibrosed glomeruli contained crescents. With intensive plasma exchange and immunosuppressive drugs, renal function improved, and hemodialysis was discontinued. After 2 years, renal function was stable at a moderate level of impairment, but heavy proteinuria persisted.

Prevention of lupus diseases in MRL/1, NZBxNZW, and BXSB mice treated with a cyclophosphazene derived drug.

A polyclonal activation of lymphocytes (PA) has been suggested to play a pathogenic role in autoimmune and immune complex diseases, particularly in mouse lupus. "DIAM 4," a cyclophosphazene derived drug, selected on the basis of its ability to modulate a PA has been used to treat female MRL/1, female NZBxNZW, and male BXSB mice. In these three strains of mice, the treatment was found to induce an inhibition of the PA, to prevent the increase of anti-DNA antibody levels and the simultaneous decrease of C3 levels, to prevent the appearance of proteinuria, the deposition of immune complexes in glomeruli, and the development of kidney lesions. Moreover in MRL/1 mice, lymphoproliferation was prevented. These results suggest that drugs able to modulate a PA might be efficient in the treatment of mouse lupus nephritis. Such a principle of immunomodulation might open the way to new possibilities of treatment of lupus and other immune complex diseases.

Polyclonal activation of lymphocytes induced in the mouse by acebutolol, a beta blocking agent.

Acebutolol, a beta blocking agent, was injected at a dose of 1 mg/day, every day for 6 months in C57B1/6 and OF1 mice. No antinuclear antibodies were induced but a transient induction of anti-single stranded DNA antibodies and an increase of IgM, IgA and IgG2a levels were observed during the first 3 weeks in some treated mice as compared to control mice. This effect was more pronounced in C57B1/6 than in OF1 mice and in the C57B1/6 mice, was more frequently observed in female than in male mice. It was further found by cellular studies done in C57B1/6 female mice, that daily i.p. or oral administration of Acebutolol induces a transient polyclonal stimulation of lymphocytes. It is concluded that certain beta blockers might possess some in vivo effects on the immune system.

In vivo modulation of polyclonal activation of lymphocytes by SOAz, a cyclophosphazene derived drug. Prevention of murine glomerulonephritis induced by chronic injections of lipopolysaccharide.

The effects of a cyclophosphazene derived drug (SOAz), on the polyclonal activation of B lymphocytes induced by bacterial lipopolysaccharide (LPS) have been studied in C57B1/6 mice. It has been found that this drug is able to inhibit the polyclonal stimulation of lymphocytes and a dose-dependent effect has been observed. The therapeutic effects of SOAz injected five times a week at 40 mg/kg/day have been investigated in mice chronically injected with LPS (twice a week, 2.5 mg/kg/day) which developed an immune complex type of glomerulonephritis. A marked prevention of glomerular lesions and of deposits of IgM and IgG, and of the third complement component has been found in mice treated with SOAz as compared to not treated mice.

[Experimental approach to the treatment of lupus nephritis by use of an accelerated model of the NZBxNZW mouse disease (author's transl)]. / Approche expérimentale du traitement des glomérulonéphrites lupiques à l'aide d'un modèle accéléré de la maladie des souris NZBxNZW.

An accelerated model of the NZBxNZW mouse disease is described. The acceleration of the disease was induced by the simultaneous injections of DNA complexed to methylated bovine serum albumin and of bacterial lipopolysaccharide which allow for the production, early in life, of high levels of anti-DNA antibodies. This new model was found to be suitable for therapeutic studies in mice with accelerated disease treated with cyclophosphamide and heparin.

[Hypothesis: immune complex glomerulonephritis and auto-immunity (author's transl)]. / Glomérulonéphrite à complexes immuns et auto-immunité.

Experimental studies on the NZBxNZW mouse lupus disease and on the development of immune complex (IC) glomerulonephritis in mouse infected with Escherichia coli lead us to state the following hypothesis: two types of factors are implicated in the development of immune complex glomerulonephritis: 1) specific factors leading to the production of IC involving antigens from the triggering agents; 2) non specific factors leading to the production of IC involving auto-antigens.

Immune complex glomerulonephritis in mice infected with Escherichia coli.

C57Bl/6 mice were injected intraperitoneally with 10(8) to 2 x 10(8) living K 38 Escherichia coli (E. coli) and serological changes and kidney involvement were studied. E. coli were found in the blood 45 min to 24 hr after injection. In serum, large amounts of deoxyribonucleic acid (DNA) were present 24 hr after E. coli injection, and thereafter disappeared. Seven days after infection, antibodies directed against E. coli, anti-DNA antibodies and C1q-binding substances were found in serum and the kinetics of the variations of these parameters were studied until day 35. Kidney lesions were evaluated immunochemically and by optical and electron microscopy. In the glomeruli, heavy granular deposits of IgG and IgM were constantly found in mesangium and along capillary walls. In most kidneys slight granular deposits of IgG and IgM were also found in the tubules. Histological studies revealed in the glomeruli mild endocapillary cell proliferation, focal thickening of glomerular basement membrane and dense deposits in mesangial and subendothelial areas and inside the glomerular basement membrane; in the tubules dense deposits were focally observed inside the tubular basement membrane.

Acceleration of glomerulonephritis in NZB x NZW mice by early immunization with DNA and injection of bacterial lipopolysaccharide. Experimental approach to the treatment of lupus nephritis by use of the accelerated model of NZB x NZW mouse disease.

The effects of early immunization with DNA and of injection of bacterial lipopolysaccharide (LPS) on the glomerulonephritis of NZB x NZW mice were studied. Combined injections of DNA complexed to methylated bovine serum albumin (DNA-mBSA) and of LPS appeared to be more efficient in accelerating the disease in NZB x NZW mice than injections of DNA-mBSA or LPS alone. A rapid increase in levels of anti-DNA antibodies, an early appearance of severe renal lesions and a shortened survival were observed in mice injected with both DNA-mBSA and LPS. This new model was found to be suitable for therapeutic studies in mice with accelerated disease treated with cyclophosphamide and heparin. The efficacy of cyclophosphamide for the treatment of NZB x NZW mouse disease was shown by immunological and histological studies in mice younger than 4 months. Heparin appeared to have a beneficial effect by preventing the endocapillary cellular proliferation induced by injections of DNA-mBSA and LPS. The accelerated model of NZB x NZW mouse disease might be a useful tool for experiments on the treatment of lupus nephritis.

Study of the correlation between glomerular and urinary sediment deposits using immunofluorescent technique.

Correlations between immunofluorescent protein deposits in the glomeruli, urinary sediment and proteinuria selectivity pattern have been attempted in different glomerulonephritis. The overall study showed following results: a) Glomerular and urinary casts deposits of immunoglobulins, C3 and fibrin/fibrinogen are related to moderately selective proteinuria; b) IgG and IgA are most often found in urinary sediment and c) Glomerular deposits of IgG and IgA are well correlated with the presence of these immunoglobulins in urinary casts. Analysis according to different histological types of nephritis: a) In "minimal changes" nephropathy, deposits are infrequent and well correlated with urinary sediment, when they are present; b) In lupus nephritis, constant and intense glomerular deposits of immunoglobulins, fibrin/fibrinogen are correlated with the same proteins found in urinary casts; c) Inconstant correlations are found in membranous nephritis and in IgA-IgG nephropathy.

[Localization of HBsAg, immunoglobulins, fibrin and C3 in the liver by direct immunoflourescence]. / Localisation en immunofluorescene directe dans le tissue hépatique de l'AgHBs, des immunoglobulines, de la fibrine et de la fraction C3 du complément

Liver biopsies of sixty patients with different forms of hepatitis and ten control subjects without hepatic disorders were examined by means of direct immunofluorescent methods for the HBsAg, immunoglobulins, fibrin and C3. The presence of fluorescent particles of HBsAg in the cytoplasm of hepatocytes were correlated with the presence of HBsAg in the serum. The fluorescence did not seem specific of histological stage of hepatitis. Immunoglobulins and fibrin were often demonstrated in hepatic sinusoids, especially in chronic aggressive hepatitis. In contrast, C3 is rarely observed.