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Biomedical subjects

R Habib

Publications and source records attributed to R Habib.

At least 55 records · Page 3Linked to original sources
PubMed1994

Comparison between pre- and posttreatment renal biopsies in children receiving ciclosporine for idiopathic nephrosis.

Fourty-two children with idiopathic nephrosis that had not been well controlled by other forms of therapy were treated with ciclosporine. Thirty-three of them were steroid dependent, 2 were partial steroid responders and 7 were steroid resistant. On pretreatment renal biopsy, performed in all patients less than 6 months before starting ciclosporine, minimal change disease (MCD) was diagnosed in 37 children and focal glomerular sclerosis (FGS) in 5. In order to evaluate the morphological changes of the renal parenchyma possibly induced by the drug, posttreatment biopsies were performed in these 42 patients: one in all patients after 4 to 28 months of ciclosporine, 2 in 23 patients after 18 to 42 months of treatment, 3 in 8 patients after 30 to 63 months of treatment and 4 in 2 patients who had been treated respectively for 62 and 63 months. The morphological changes on pre- and posttreatment biopsies were scored according to the severity of tubulointerstitial lesions. Grade I was considered when there were no significant changes of the renal parenchyma or when occasional scattered tubules with thickened basement membranes were present. Grade II was diagnosed when the biopsy showed several small foci of atrophic tubules with thickened basement membranes within stripes of interstitial fibrosis and grade III when confluent or extensive areas of interstitial fibrosis with atrophic and/or collapsed tubules were observed. On pretreatment renal biopsy, only one patient showed tubulointerstitial lesions (grade II). On the latest biopsy obtained, 18 patients showed grade I tubulointerstitial lesions, 15 grade II and 9 grade III. Unspecific arteriolopathy was observed in 10 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1994

Recurrence of de novo membranous glomerulonephritis on renal grafts.

An updated study of the glomerular lesions found in renal grafts in children showed 3 features of interest. 1) In our experience, the incidence of the occurrence of de novo membranous glomerulonephritis (MGN) remains around 9% (48 of 530 grafts). 2) Of the 29 patients we reported in a previous study [Antignac et al. 1988], 18 lost their grafts and 7 received a second graft. Four of these 7 patients recurred de novo MGN on their second graft. Their clinical course is reported in detail. 3) In our population of transplanted children, of the 55 patients who received a second graft, the only recipients who developed a de novo MGN were the 4 patients who had already developed de novo MGN on their first graft. The various factors possibly involved in the pathogenesis of de novo MGN are reviewed. The high incidence of recurrence of de novo MGN indicates that host factors play a major role in the development of this nephropathy.

Child↗
PubMed1994

Cyclosporin A nephropathy: standardization of the evaluation of kidney biopsies.

An advisory board of nephropathologists with personal experience in the evaluation of biopsies from patients treated with cyclosporin A (CyA) was set up to address the following problems: 1. Definition of CyA nephropathy as seen in patients with autoimmune diseases; 2. Evaluation of the reliability and reproducibility of the diagnostic criteria for the different morphological lesions seen in CyA nephropathy; 3. Classification of the morphological lesions according to their clinical relevance; 4. Estimation of the possible progression of CyA nephropathy with continuous CyA therapy. The most frequent lesions attributable to CyA therapy in patients with autoimmune diseases are tubular atrophy, interstitial fibrosis, and arteriolar hyalinosis. All other lesions are rare. The reproducibility and diagnostic reliability is high for tubular atrophy and interstitial fibrosis, but low for arteriolar lesions even among experienced nephropathologists. The biopsies may be classified according to the severity of tubular atrophy, interstitial fibrosis and arteriolar hyalinosis with regard to their clinical relevance: In group I (within normal limits), CyA therapy can be continued; in group III (moderate-to-severe CyA-related lesions), CyA should be stopped if possible. Among group II biopsies (slight CyA-related abnormalities), no recommendation can be made in the absence of a second biopsy after a further year of CyA therapy. No clear-cut answer can be given concerning the progression of CyA-induced lesions. However, no significant progression has been found in the cases studied to date.

Adolescent↗
PubMed1993

Nephrotic syndrome in the 1st year of life.

Among the various primary conditions which may be associated with a nephrotic syndrome at birth or within the 1st year of life, the best known is the congenital nephrotic syndrome of finnish type (CNF) characterized by irregular pseudocystic dilatation of proximal tubules. This disease, very frequent in Finland, is often familial with an autosomal recessive mode of inheritance. Patients are steroid resistant, but the cause of death is usually not uraemia but infection or severe diarrhoea with electrolyte imbalance. The second condition is idiopathic nephrosis including minimal change disease, diffuse mesangial proliferation and focal segmental glomerular sclerosis. As opposed to CNF, infants with "early onset nephrosis" may respond to steroid therapy as older children do and may even recover. However, there are no histopathological criteria which allow the certain differentiation of idiopathic nephrosis from CNF. The third condition is diffuse mesangial sclerosis (DMS), a clinicopathological entity which can occur as an isolated finding or be associated with male pseudohermaphroditism and/or Wilms' tumour (Drash syndrome). From a morphological point of view, DMS is easy to differentiate from CNF because of the characteristic pattern of involvement of the glomeruli. From a clinical point of view, the nephropathy, almost always characterized by a nephrotic syndrome, has two distinct features: it is most often diagnosed in the first 2 years of life and it progresses rapidly to end-stage renal failure, which usually occurs before the age of 3 years. The clinical findings in 36 patients with DMS are presented. The nephropathy was isolated in 22 infants and associated with male pseudohermaphroditism and/or Wilms' tumour in 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Disorders of Sex Development↗
PubMed1993

Collagen type III glomerulopathy: a new type of hereditary nephropathy.

A new type of hereditary glomerulopathy was observed in ten children presenting with early and progressive glomerular symptoms, often associated with hypertension. Light microscopy showed a diffuse increase in the mesangial matrix and generalized widening of the capillary walls. Electron-microscopic examination of renal tissue, after phosphotungstic acid treatment, revealed the presence of fibrillar collagen within the mesangial matrix and the subendothelial aspect of the glomerular basement membrane, adjacent to normal lamina densa. Immunohistochemical studies identified the fibrillar collagen not usually present within the glomerular extracellular matrix as type III collagen. Clinical and family studies ruled out the diagnosis of nail-patella syndrome, an autosomal dominant disorder with typical extrarenal symptoms, which is also characterized by the presence of fibrillar collagen within the glomerular basement membranes. The poor renal outcome, the possible extrarenal haematological and pulmonary involvement and the transmission as an autosomal recessive trait strongly suggest that collagen type III glomerulopathy is a new type of hereditary disease. From the high incidence of superimposed haemolytic uraemic syndrome in patients or their siblings, it may be hypothesized that collagen type III glomerulopathy is the underlying defect in some of the familial cases of haemolytic uraemic syndromes.

Adolescent↗
PubMed1993

Branching airway network models for analyzing high-frequency lung input impedance.

The input impedance of the lung (Zin) at high frequencies (> 100 Hz) is a complex function of the airway geometry and the mechanical properties of the airway walls. To investigate how the purely geometrical factors influence Zin, we measured Zin between 16 and 1,520 Hz in six dried dog lungs with the forced oscillation technique. In each of the lungs we found three resonances, at 36 +/- 5, 648 +/- 100, and 1,289 +/- 150 Hz, and at least two antiresonances (relative maxima in the real part of Zin), at 372 +/- 60 and 1,105 +/- 110 Hz. These data were fit with models featuring a detailed asymmetric branching network of the airways obtained from morphometric data published by Horsfield et al. (J. Appl. Physiol. 52: 21-26, 1982). On the basis of low-frequency (< 100 Hz) data alone, we first established a model of the acini, which was then attached to the end of the airway branching model. With a single scaling factor for the radius and length of the airways, the fit was unsatisfactory. Using sensitivity analysis techniques we determined which candidate variables of the structural model could influence Zin in a manner to improve the fit. We found that a two-parameter model accounting for separate central and peripheral airway diameter scaling provided a reasonable fit to Zin. On average the model required central diameter scaling close to unity (0.94 +/- 0.09), and the peripheral diameter scaling factor was 0.87 +/- 0.38. Over a range of parameter values that we believed were physiologically reasonable (i.e., scaling factors between 0.5 and 1.5), a single set of parameter values was found in all lungs. These results suggest that structurally based inverse models of Zin that include multiple antiresonances may provide information about airway geometry.

Airway Resistance↗
PubMed1993

Clinical significance of allograft glomerulopathy.

During the period from January 1973 to December 1990, 774 renal transplantations in 698 children were performed in our renal unit. A total of 540 grafts were examined both by light and immunofluorescence microscopy at least once. Recurrent glomerulonephritis was diagnosed in 62 grafts, de novo glomerulonephritis in 68 and allograft glomerulopathy in 38 (7%). The term allograft glomerulopathy (AGP) refers to the very specific pattern of glomerular involvement unique to renal allografts and characterized by: (1) widespread reduplication of the glomerular basement membrane due to a widening of the subendothelial space associated with (2) moderate increase in mesangial matrix and (3) interposition of mesangial matrix and cells. AGP is a glomerular manifestation of chronic rejection and is almost always associated with obliterative vascular changes. In our experience it is present in 25% of long-standing grafts (more than 10 years), but may develop early in the post-transplantation period (5 cases within the first year). In 13 of 33 patients in whom early biopsies were available, a different pattern characterized by a hypercellularity and the presence of monocytes-macrophages in the mesangial areas was observed. We suggest that this hypercellular pattern might be the early stage of the disease and could be called "acute allograft glomerulopathy" as opposed to the pattern characterized by reduplication of the glomerular basement membrane which deserves the name of "chronic allograft glomerulopathy." The exact relationship between these two patterns remains to be determined. Clinicopathologic correlations showed that chronic AGP is often associated with marked proteinuria. However, in our series proteinuria was absent or minimal in 25% of the cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Graft Rejection↗
PubMed1993

A specific glomerular lesion of the graft: allograft glomerulopathy.

During the period from January 1973 to December 1970, 774 renal transplantations in 698 children have been performed in our Renal Unit. A total of 540 grafts have been examined both by light and immunofluorescence microscopy at least once. Recurrent glomerulonephritis was diagnosed in 62 grafts, de novo glomerulonephritis in 68 and allograft glomerulopathy (AGP) in 38. AGP was defined as a lesion affecting all glomeruli and characterized by widespread reduplication of the GBM with widening of the subendothelial space and interposition of mesangial matrix and without significant deposits by immunofluorescence. The aim of the current study is to describe the natural history of AGP and to delinate its clinical significance. At time of biopsy, an increase in serum creatinine was present in 30 patients associated with a proteinuria > or = 1 g/day in 21. During the post-transplantation course, proteinuria was present in 29 patients and associated with a nephrotic syndrome in 10 of them. With a mean follow-up of eight years seven months, two patients died, 23 lost their grafts and 13 have a functioning graft. The lesions of AGP recurred in three of the nine children who received a second graft. Thirteen of the 33 patients in whom earlier biopsies were performed showed a different pattern of involvement characterized by a prominent swelling of active endothelial and mesangial cells and a hypercellularity related to the presence of mononuclear cells both in the lumens and in the mesangial areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

[Renal involvement in autoimmune enteropathies].

The authors report on a infant who presented with an auto-immune enteropathy characterized by the association of a protracted diarrhea, a neonatal insulin-dependent diabetes, and a dermatitis and who developed a nephrotic syndrome at 4 months of age. A renal biopsy showed a membranous glomerulonephritis (MGN) with IgG linear deposits along the tubular basement membranes (TMB). By indirect immunofluorescence anti-enterocyte antibodies together with anti-TMB antibodies and anti-renal brush border (BB) antibodies were found in the serum of the patient. The patient received various immunosuppressive drugs that failed to improve the disease. In the course of the disease the anti-TBM antibodies disappeared progressively but the BB antibodies persisted. A review of the literature indicates that renal involvement is not uncommon in auto-immune enteropathy and in 5 cases it has been reported as being characterized by a nephrotic syndrome related to the presence of a MGN. In 4 of these cases MGN was associated with the presence of anti-TBM antibodies and in the remaining one with anti-BB antibodies. This case report shows that in human pathology, auto-antibodies to BB proteins may, as well as in experimental models, be responsible for the development of a MGN. It suggests a close relationship (probably a common epitope) between the renal BB proteins and the proteins of the gut epithelium.

Autoimmune Diseases↗