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Biomedical subjects

M Fabre

Publications and source records attributed to M Fabre.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Malignant rhabdoid tumor of the kidney. A poorly differentiated type with difficult diagnosis].

Rhabdoid tumour of the kidney is a rare, distinct clinico-pathological entity, mostly occurring in children, with an extremely aggressive behaviour. There is a wide range of histologic patterns. We report a case in which the classical "rhabdoid" cytology with eosinophilic cytoplasmic inclusions and macronucleoli was scanty and abundant cytoplasm was absent. Immunocytochemical and ultrastructural studies were essential. This poorly differentiated type of rhabdoid tumour must not be confused with Wilms' tumour because it requires an intensive chemotherapy regimen.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Histologic characteristics of posterior lumbar epidural fatty tissue].

The aim of this study was to describe the histological specificities of posterior lumbar epidural fat (PLEF) considered a "semi-fluid" tissue. We performed axial histological sections of posterior lumbar epidural fat through the abdomen of two foetuses, as well as histological sections on several planes in 11 adults. For comparison, we simultaneously cut sections in subcutaneous fat of adults (SCF). In the foetuses the epidural fat was arranged around the dural sac and extended along the entire lumbar spine, whereas in adults the epidural fat was discontinuous and the fat pads were located at intervertebral disc level, in a trianglular space with posterior apex, limited by the ligamenta flava laterally and by dural sac anteriorly. The PLEF was a homogeneous tissue in both size and shape and consisted of regular adipocytes and little connective tissue. In contrast, the SCF was made of adipocytes which varied in size and shape and were accompanied by numerous connective fibers (fibrous cones) subdividing the hypodermis into lobules. But the main specificity of the PLEF was the oriented empty spaces or slits found and observed in all samples with a special arrangement. These slits subdivided the fat into several layers enabling them to slide and could be regarded as "sliding spaces". They were never observed in the SCF samples. PLEF, therefore, is not a simple filling tissue. Its histological features (homogeneity, scarcity of connective tissue and oriented slits) explain the "semi-fluid" characteristic and confirm the specialization of this fat tissue. Its location at the level of the mobile segment of the lumbar spine suggests that it plays a role of sliding structure between the posterior surface of the thecal sac and the anterior surface of the vertebral arch.

Adipose Tissue↗
PubMed1996

[Role of guided fine needle punction in the diagnosis of deep-seated Aids-related infections. Report of a case of hepato-nodal histoplasmosis].

A case of disseminated histoplasmosis diagnosed by fine needle aspiration biopsy is reported. The patient suffering from acquired immune deficiency syndrome (AIDS) had enlarged liver, spleen and mesenteric lymph nodes. Cytological smears prepared from a CT scan guided fine needle aspiration biopsy of one of the lymph node and the liver, showed numerous free or intrahistiocytic yeasts consistent with Histoplasma capsulatum. Yeasts and protozoars morphologically close to Histo-plasma capsulatum are reviewed. The indications of fine needle aspiration biopsy for the diagnosis of infections in AIDS patients are emphasized. This method enables to send rapidly material for cultures and to start immediately an appropriate treatment.

AIDS-Related Opportunistic Infections↗
PubMed1995

Cholangiographic features in fibrosis and cirrhosis of the liver. Radiological-pathological correlation.

The cholangiographic features of intrahepatic bile ducts associated with cirrhosis or fibrosis are not well known. In order to achieve a radiological-pathological correlation, we studied nine livers with fibrosis or cirrhosis excised at autopsy. Cholangiograms were obtained within 24 hr after death from the nonfixed liver and multiple tissues samples were taken for histologic examination. Radiological data were interpreted by two independent investigators blinded to the clinical and histological findings. Cirrhosis (alcoholic in 4, posthepatitis in two) was observed in six livers, fibrosis (alcoholic in 2, posthepatitis in one) in three. No liver with fibrosis had cholangiographic abnormalities. In contrast, cholangiography of all livers with cirrhosis was abnormal. Abnormalities were a diminished arborization, a decrease of the distal opacification, an irregularity of caliber, and a tortuous course of the bile ducts. Histological study showed that the irregular and tortuous course were due to compression of the bile ducts by regenerative nodules. Furthermore, a thick fibrosis was organized around the bile ducts. In conclusion, fibrosis alone was not associated with cholangiographic abnormalities. In cirrhotic livers, intrahepatic bile ducts showed an irregular and tortuous course, a diminished arborization and a decrease of the distal opacification. These abnormalities were secondary to the presence of regenerative nodules and fibrosis organized around the bile ducts.

Autopsy↗
PubMed1995

Proliferation and differentiation of a human hepatoblastoma transplanted in the Nude mouse.

A pure epithelial human hepatoblastoma was directly transplanted to athymic Nude mice to provide a model system to study proliferation and differentiation of these tumoral cells. The first transplantation selected the embryonal component of this tumor, while subsequent passages selected in addition neuroendocrine and mesenchymal cells that evolved into osteoid and bony trabeculae. The embryonal character of this hepatoblastoma was further demonstrated by the expression of glutamine synthetase mRNA and a fetal pattern of mRNAs encoding insulin-like growth factor II. However, alphafetoprotein mRNA was detectable in neither the original nor the transplanted tumors. Finally, although p53 mRNA levels were increased, no mutation was detected in the p53 gene.

Animals↗
PubMed1995

Endothelium-dependent relaxation in the isolated rat kidney: impairment by cyclosporine A.

The therapeutical use of cyclosporine A (CsA) is hampered by the development of nephrotoxicity characterized by a marked increase in renal vascular resistance (RVR). We investigated vascular functions in kidneys of rats treated with CsA. The ex vivo vascular reactivity of kidneys from control rats and animals treated subacutely with CsA [50 mg/kg/day subcutaneously (s.c.) for 16-21 days] or an olive oil vehicle (1 ml/kg) was analyzed in male Wistar rats. The right kidney was isolated and perfused with Tyrode's or Krebs solution in an open circuit. The effects of acetylcholine (Ach), fenoldopam (FEN), and sodium nitroprusside (SNP) on norepinephrine (NE) preconstricted kidneys were studied. In control kidneys (untreated or vehicle-treated), Ach induced a relaxation (EC50 = 0.56 +/- 0.05 x 10(-9)M; Emax = 88.2 +/- 2.1% decrease in the vascular tone restored by NE) which was endothelium-dependent [near-complete abolition after treatment with a detergent, 3-[(3-cholamidopropyl)-dimethyl-ammonio]-1-propane-sulfonate (CHAPS) treatment] but only partially inhibited by indomethacin (EC50 = 1.71 +/- 0.39 x 10(-9)M, p < 0.05; Emax = 87.1 +/- 4.9%, NS) or indomethacin with NG-nitro-L-arginine methyl ester (L-NAME: EC50 = 1.04 +/- 0.38 x 10(-9)M, NS; Emax = 63.8 +/- 2.5%, p < 0.01). CsA treatment induced a marked decrease in creatinine clearance and natriuresis measured in vivo but had no effect on systolic blood pressure (SBP). In CsA-treated rats, Ach-induced renal relaxation was partially blunted (EC50 = 1.88 +/- 0.34 x 10(-9)M, p < 0.01; Emax = 82.8 +/- 4.6, NS), with both a defect in prostaglandin (PG) and nitric oxide (NO)-related responses. CsA treatment had no effect on endothelium-independent relaxations induced by FEN and SNP. These results show that subacute CsA treatment selectively impairs renal endothelium-dependent relaxation related to PGs and NO release.

Animals↗
PubMed1995

[Reliability of the anatomopathological diagnosis by static image transfer].

50 hepatic biopsies and 50 prostatic biopsies were submitted for diagnostic to an expert by the mean of static images previously digitalized by a consulting pathologist. Accuracy of diagnosis was obtained in 2 minutes with 4 images in 86% of cases. Additional data such as new images, several power fields, permitted accuracy of diagnosis in 98% of the cases. The experiences showed clearly that the quality of the transferred static images is sufficient to allow diagnoses. It pointed out the importance of the different actors involved in the consultation. It illustrates the possible use of this system as a training tool.

Female↗
PubMed1994

Outcome of ABO-incompatible liver transplantation in children with no specific alloantibodies at the time of transplantation.

The shortage of suitable liver donors for children has motivated the use of ABO-incompatible (ABO-I) grafts for transplantation in urgent situations. However, survival after ABO-I liver grafts has been reported at about 30% as compared with 80% in cases of ABO-identical or -compatible liver grafts. This difference has been attributed to antibody-mediated, hyperacute or chronic liver rejection, due to preformed ABO antibodies (alloantibodies). In this study, we report our results with ABO-I livers in children without alloantibodies at the time of transplantation. From January 1988 to June 1993, 143 OLT were performed in 122 children. Eight children received 8 ABO-I liver grafts. Of these, 7 patients were included in the study. All 7 were alloantibody free before OLT. Five children were spontaneously alloantibody free, while in 2 children, the plasma alloantibodies were eliminated before and after transplantation using intravenous infusion of specific blood group antigens of the donor blood group (soluble antigens). Immunosuppression consisted of a triple-drug treatment combining CsA, AZA, and steroids. The follow-up period was between 10 and 48 months. One child died from a surgical complication. Six children survived, but 1 died 10 months later from intestinal obstruction. There were no graft losses and no episodes of hyperacute or chronic rejection. The graft and patient survival rate was 71%. There was a 28% incidence of rejection, but all were mild (requiring steroid boluses only). Our results suggest that the absence of ABO alloantibodies at the time of and after transplantation can protect ABO-I liver grafts against antibody-mediated rejection, whether hyperacute or chronic, and that soluble antigens are effective in eliminating alloantibodies in children.

ABO Blood-Group System↗
PubMed1994

Antipeptide antibodies directed against the C-terminus of protein kinase C zeta (PKC zeta) react with a Ca(2+)- and TPA-sensitive PKC in HT-29 human intestinal epithelial cells.

We have studied the PKC isoforms present in HT-29 M6 colon cancer cells, the differentiation of which to mucus-secreting cells is blocked by TPA. In addition to a major 72 kDa band, a 77 kDa PKC isoform was recognized by two different antibodies raised against a C-terminus-specific peptide for the TPA-insensitive isoform, PKC zeta. By different criteria (association to the membrane, down-regulation, PKC activity in immunoprecipitates) we conclude that, contrary to the 72 kDa band, the 77 kDa band corresponds to a Ca(2+)- and TPA-sensitive PKC. These results suggest that antipeptide antibodies directed against the C-terminus of PKC zeta react in human cells with a member of the conventional PKC subfamily besides PKC zeta. Therefore, the data indicating that PKC zeta is sensitive to different agents in various cell lines should be carefully re-evaluated.

Amino Acid Sequence↗
PubMed1994

Liver cytochrome c oxidase deficiency in a case of neonatal-onset hepatic failure.

In the last few years, inborn errors of oxidative phosphorylation have been recognized as possible causes of hepatic failure in infancy and respiratory enzyme deficiencies have been described in several tissues of affected individuals. Here, we report on cytochrome c oxidase deficiency in the liver but not in the skeletal muscle of a 5-month-old girl who presented hepatic failure in early infancy. Persistent hyperlactatemia (> 4 mM, normal < 2.4) with high lactate/pyruvate (L/P) molar ratios in plasma, and their further elevation in the post-absorptive period were suggestive of an inborn error of oxidative phosphorylation. However, no mutation in the coding sequences of the liver-specific subunits of cytochrome c oxidase (VIa and VIIa) has been detected and no major rearrangement or depletion of the mitochondrial DNA has been observed. Based on this observation we suggest that inborn errors of oxidative phosphorylation be considered in the diagnosis of severe hepatocellular dysfunction of unknown origin, especially when an abnormal oxidation-reduction status is found in the plasma and even if normal respiratory enzyme activities are found in peripheral tissues. The findings of normal respiratory enzyme activities in skeletal muscle, circulating lymphocytes or cultured skin fibroblasts does not rule out this diagnosis. Instead, the negativity of these tests should prompt one to carry out the specific enzyme assays in the tissue which expresses the disease, namely the liver.

Cytochrome-c Oxidase Deficiency↗
PubMed1994

Differential expression of the small inducible cytokines GRO alpha and GRO beta by synovial fibroblasts in chronic arthritis: possible role in growth regulation.

Synovial pannus represents a hypertrophic and locally invasive connective tissue response to chronic inflammation that accounts in large part for the periarticular destruction of rheumatoid arthritis. Synovial fibroblasts cultured from rheumatoid synovia have been found to display an increased rate of proliferation and the constitutive expression of collagenases, growth factors, and inflammatory cytokines. The existence in rheumatoid synovium of both a pro-inflammatory state and growth dysregulation led us to investigate the expression by synovial fibroblasts of the closely homologous cytokines GRO alpha (gro/MGSA), GRO beta (MIP-2 alpha), and GRO gamma (MIP-2 beta). These cytokines are released by a variety of cell types and display overlapping growth regulatory and pro-inflammatory activities. In contrast to expectations, the majority of synovial fibroblast cell lines derived from osteoarthritic or non-inflammatory synovia showed a relative increase in the constitutive expression of GRO alpha and GRO beta when compared to synovial fibroblasts obtained from rheumatoid synovia. Considered together with evidence that GRO alpha is a growth regulator that modulates the expression of metalloproteinase activity, these findings provide evidence for a differential pathway of cytokine activation that may downregulate the proliferative and erosive response to chronic arthritis.

Actins↗