PubMed Health⌕ Search

Biomedical subjects

I Aarons

Publications and source records attributed to I Aarons.

16 recordsLinked to original sources
PubMed1989

The structure of the normal human glomerular basement membrane. Ultrastructural localization of type IV collagen and laminin.

Structural models of the glomerular basement membrane (GBM) have been based solely on the localization of antigens in animal kidneys. These models depict a type IV collagen lattice as the structural skeleton along the central portion of the membrane, with the glycoprotein laminin attached predominantly in the laminae rarae where it is thought to be involved with endothelial and visceral epithelial cell attachment. The human GBM is also known to contain type IV collagen and laminin. The present study localizes both of these structural antigens in normal human GBM using the ultrastructural immunogold technique. Type IV collagen is situated in the sub-endothelial third of the GBM and is continuous with the type IV collagen within the mesangial matrix. Laminin is localized throughout the entire thickness of the GBM and mesangial matrix. These results indicate that the structure of human GBM is significantly different from that proposed in animal models. A structure for the normal human GBM is discussed, depicting a thin type IV collagen lattice which is asymmetrically placed in the sub-endothelial third of the membrane, with laminin distributed as an integral component of the membrane in addition to its role in cell attachment.

Basement Membrane↗
PubMed1989

Quantitation of glomerular angiotensin II receptors in IgA nephropathy.

Mesangial cells have receptors for angiotensin II (AII) and contract in its presence. All is known also to increase the uptake of macromolecules by the mesangium. As a first step towards the investigation of a possible role for local disturbances of the renin-angiotensin system (RAS) in immune mediated mesangial proliferative glomerulonephritis, glomerular All receptors have been quantitated retrospectively in biopsy tissue from 20 patients with IgA nephropathy for comparison with 16 biopsies that showed only minor abnormalities by light microscopy and negative immunofluorescence. An autoradiographic technique using 125I labelled [Sar1, Ile8] All facilitated the quantitation of All receptors in frozen tissue sections. Following exposure to the treated sections, x-ray film was analyzed by computerized micro-densitometry. The data obtained were optical densities of areas corresponding to the presence of glomeruli verified by reference to adjacent sections stained with periodic acid-Schiff (PAS). There was no significant difference between patients 0.67 +/- 0.16 (mean +/- SD) and controls 0.61 +/- 0.15. Among patients there was no statistically significant correlation of glomerular All receptor density with either the degree of mesangial proliferation or the extent of hyperplasia of the juxtaglomerular apparatus (JGA). There was no apparent relationship with hypertension. The absence of an increase in glomerular All receptors despite proliferation of the glomerular mesangium may represent a local down regulation in patients with IgA nephropathy.

Adult↗
PubMed1989

Thin membrane nephropathy: a clinico-pathological study.

Thin membrane nephropathy is common, representing approximately 11% of non-transplant renal biopsies. A family history of renal disease is present in at least 40% of patients. Electron microscopy is essential for its diagnosis. There are no immunofluorescence markers but light microscopic changes, usually mild, are invariably present and predict the ultrastructural findings although there is no correlation with their degree. The extent of the morphological changes bears no obvious relationship either to clinical or familial features. Immunogold studies indicate that there is reduction or loss of the subepithelial portion of the basement membrane, which apparently contains normal amounts of type IV collagen. Unnecessary urological investigations may be avoided by awareness of the condition and microscopic examination of urine for dysmorphic red blood cells. Prospective long-term studies are necessary to determine the nature and consequences of the condition.

Adolescent↗
PubMed1988

The effect of treatment with prednisolone or cyclophosphamide-warfarin-dipyridamole combination on the outcome of patients with membranous nephropathy.

Between 1973 and 1986, 109 patients with membranous nephropathy have been evaluated with respect to clinical presentation, pathological features and factors determining prognosis. Secondary disease was present in 21, and a further 21 were lost or followed for less than 12 months. The remaining 67 with idiopathic membranous nephropathy were allotted to one of three groups. Group 0 (26 patients) received no active treatment, Group 1 (12 patients) a combination of cyclophosphamide, dipyridamole and warfarin, and Group 2 (21 patients) high dose alternate day prednisolone therapy. Eight patients received other treatment or presented with end stage renal disease. No significant difference in outcome could be detected between the groups. Remission rates were equivalent as were numbers of patients judged as having progressive disease. There was no statistical difference with respect to duration of nephrotic syndrome, plasma creatinine at the end of study and change in plasma creatinine. No demonstrable benefit was obtained in predicting the outcome of disease or response to treatment from conventional pathological grading of stages I to IV as approximately equal numbers of each stage fell into good and bad categories of outcome. Similarly unusual histological features such as mesangial proliferation and immunofluorescence for deposits other than IgG and C3 were not helpful. A different approach to treatment of idiopathic membranous nephropathy is strongly recommended.

Adolescent↗
PubMed1987

Adult Henoch-Schönlein nephritis.

A retrospective study was performed of all patients at the Royal Adelaide Hospital over a ten-year period with biopsy proven Henoch-Schönlein nephritis. The records of 27 patients were examined, with emphasis on clinical and histopathological presentation, treatment and outcome. A scheme for assessing glomerular histology is presented, and severity correlated with prognosis of the disease. At presentation unfavourable prognostic indicators were acute renal impairment, crescents in greater than 20% of glomeruli, and severe glomerular histological lesions. Four patients died as a result of the disease, and 20 of the patients had evidence of continued renal abnormality at follow-up. Adult Henoch-Schönlein nephritis is a potentially catastrophic disease, and requires careful assessment at presentation.

Biopsy↗
PubMed1987

IgA nephropathy.

IgA nephropathy is a syndrome and probably the most important glomerular disease in terms of incidence and mortality. This review documents the clinical and pathological features and concentrates on the evolving thoughts regarding pathogenesis and treatment.

Adult↗
PubMed1986

Correlation of paramesangial deposits and glomerular sclerosis and/or hyalinosis in patients with IgA nephropathy.

Correlation of paramesangial deposits ("hemispherical body") and glomerular sclerosis and/or hyalinosis was examined by light microscopical analysis in 40 patients of IgA nephropathy. Correlation of paramesangial deposits and intensity of IgA or C3 deposition in glomeruli was also evaluated in these patients. The number of paramesangial deposits was markedly increased in patients with moderate and advanced stages of IgA nephropathy who showed marked glomerular sclerosis and/or hyalinosis. There was a significant correlation between the number of paramesangial deposits and the intensity of IgA deposits in glomeruli. It is suggested that the accumulation of paramesangial deposits might induce severe glomerular injuries such as glomerular sclerosis and/or hyalinosis.

Complement C3↗
PubMed1984

Focal prostatic granulomas rheumatoid like--probably iatrogenic in origin.

Small focal rheumatoid nodule-like granulomas have been noted in the prostatic chips from 11 repeat transurethral resections (TUR) in 10 patients. The lesions are situated in the prostatic stroma and are characterized by a central zone of fibrinoid necrosis, a peripheral palisade of fibroblasts and histiocytes and variable numbers of lymphocytes and giant cells. These granulomas are only noted in prostatic tissue from repeat TURs, are not evident in the original TUR tissue and probably have an iatrogenic basis. As yet, they appear to be of no clinical significance, but the entity is not well recognized, and the surgical pathologist should guard against over-interpretation of the lesions.

Aged↗
PubMed1984

The syndrome of IgA nephropathy.

A review is presented of the current knowledge concerning the syndrome of IgA nephropathy. Primary and secondary forms can now be delineated and this division has improved understanding of immunopathogenetic mechanisms giving rise to glomerular mesangial IgA deposits. Attention is paid to disorders of antigen exclusion at mucosal surfaces, defective reticulo-endothelial sequestration, and altered immunoglobulin A production and regulation. Particular reference is made to these mechanisms with respect to primary IgA nephropathy, Henoch-Schoenlein purpura and mesangial IgA nephritis associated with alcoholic cirrhosis.

Adolescent↗
PubMed1982

Renal lesions in leptospirosis.

Renal function studies and kidney biopsies were performed in four patients presenting with renal insufficiency and acute Leptospira pomona infection. The renal lesion in all patients revealed acute interstitial nephritis. There was no evidence of immunologically mediated disease in three patients who were biopsied seven, eight and eight days respectively following the onset of symptoms. The fourth, in whom there was no evidence of prior renal disease, and whose biopsy was performed 16 days after symptoms began, showed glomerular Clq, and C3 immunofluorescence and mesangial, subepithelial and intramembranous dense deposits by electron microscopy. In addition, circulating immune complexes were demonstrated in this patient. These findings suggest that in this instance at least, the renal lesions of Leptospira pomona infections can be immunologically mediated. Because this may well be a transient phase, the timing of investigations could be crucial to its detection.

Adult↗
PubMed1982

Malignant clear cell hidradenoma: a case report.

A 73-year-old man developed a malignant clear cell hidradenoma on the nose. Although it was treated solely with diathermy and curettage it did not recur. These rare tumours are histologically malignant but do not always behave aggressively. In some patients local growth and recurrence may occur, while in others the tumour metastasizes widely. There is no way of predicting how these tumours will behave.

Adenoma, Sweat Gland↗
PubMed1979

Thiamphenicol and lupus nephritis. The effects of long-term therapy on kidney function and pathology: a pilot study.

NZB x OUW F1 hybrid mice were treated with thiamphenicol at 25, 50 and 250 mg/kg/day from the time of their first positive antinuclear antibody test until their death. Untreated mice fed the same diet served as controls with body weight, mortality and renal disease patterns conforming to published reports of the biology of the BW mice. Regular testing of urine and bloodm and detailed postmortem examinations showed (a) that with increasing drug dose levels heavy proteinuria was almost eliminated and blood urea concentrations significantly lowered; (b) that in treated and untreated mice moderate to severe anaemia developed, apparently unrelated to the degree of uraemia; (c) that changes in renal function did not correlate with antinuclear antibody activity, nor did the drop in packed cell volume correlate with fixed or free circulating antierythrocyte autoantibody positivity; (d) that histological analysis of renal changes showed that at the highest dose level glomerular lesions were minimal. Thus the prolonged treatment with thiamphenicol reduced the severity of the spontaneous renal disease and resulted in a significant extension of lifespan.

Animals↗
PubMed1979

Thiamphenicol and lupus nephritis. II. The effects of giving the drug from weaning to NZBxOUW F1 hybrid female mice.

Thiamphenicol at the rate of 50 mg/kg/day given to female NZBxOUW F1 hybrid mice from weaning and continuing throughout life resulted in a considerable extension of lifespan, although this was less than in mice given the same drug dosage from first antinuclear antibody (ANA) positivity (Simpson, Aarons and Howie, 1979). Assessment of the changes in renal dysfunction and renal histology shows that thiamphenicol treatment did not prevent the development of immune complex glomerulonephritis although the rate of progression of the disease was slower than in untreated controls. Thiamphenicol failed to influence greatly the progressive anaemia which develops in these mice or to alter the pattern of ANA production. Although azotaemia developed in treated mice it was a terminal event. It was concluded that the action of thiamphenicol was to depress but not prevent immune complex formation possibly by impairing immunoglobulin formation although why immunofluorescent ANA formation remained unaffected is not understood.

Animals↗
PubMed1978

Goodpasture's syndrome complicated by nocardia asteroides infection.

A case of Goodpasture's syndrome--an immunological disorder characterised by a proliferative glomerunlonephritis with haemorrhagic pulmonary alveolitis--is described. There has been complete functional recovery of the presenting renal failure, but the immunosuppressive therapy was complicated by a severe episode of metastasising nocardiosis.

Adult↗
PubMed1977

Classification of glomerulonephritis.

A classification of glomerulonephritis which is being used as a basis for the New Zealand National Study of Glomerulonephritis is presented, together with comments about the salient pathological features of each type of glomerular disease.

Biopsy↗