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Biomedical subjects

D Figarella-Branger

Publications and source records attributed to D Figarella-Branger.

At least 127 records · Page 7Linked to original sources
PubMed1996

Correlation between polysialic-neural cell adhesion molecule levels in CSF and medulloblastoma outcomes.

PURPOSE: To quantify CSF levels of polysialic-neural cell adhesion molecule (PSA-NCAM) in patients with medulloblastoma (MB) metastasis, to assess the correlation with other diagnostic techniques (imaging and cytology) and clinical features, and to determine whether it is a suitable marker to monitor response to treatment and subsequent follow-up data. PATIENTS AND METHODS: PSA-NCAM levels were measured using a double-site enzyme-linked immunoadsorbant assay (ELISA) in 145 samples from 14 controls and 29 patients with MB. Clinical status of patients, imaging, and cytologic data were available at the time of each lumbar puncture. Medians and ranges for the 131 pooled PSA-NCAM concentrations were calculated for the MB versus the control groups, and for MB patients for normal versus abnormal groups at cytology or imaging, and for four clinical subgroups, respectively. For patients with MB, three PSA-NCAM measurements that corresponded to punctures performed during three time periods following surgery were selected. The kappa measure of agreement was calculated between normal and abnormal groups at cytology or imaging, and between groups of patients in remission and refractory, respectively. For the same phases, sensitivity and specificity of PSA-NCAM and cytology tests and their 95% confidence intervals (95% CIs) were computed. RESULTS: PSA-NCAM was never detected in control CSF. PSA-NCAM concentration medians were higher in CSF with metastatic cells or that corresponded to abnormal imaging than in the corresponding normal groups (P < .05). The PSA-NCAM concentration median was significantly higher (P < .05) in CSF from patients refractory to treatment or who relapsed than from patients in remission. Agreements between PSA-NCAM and clinical status and between PSA-NCAM and cytology were excellent during and after treatment. The sensitivity of PSA-NCAM test was always better than that of cytology, whereas its specificity was lower for phases that corresponded to more than 1 month following surgery. However, specificity was 100% for patients refractory to treatment or with relapse. CONCLUSION: PSA-NCAM measurement appears to be a new biologic marker of possible use in the management of patients with MB.

Biomarkers, Tumor↗
PubMed1996

Absence of correlation between reg and insulin gene expression in pancreas during fetal development.

The reg gene characterized in the exocrine pancreas has been found to be expressed in regenerating islets of 90% depancreatized rats and not in normal islets. In humans, it was identified only in the exocrine pancreas. Because the reg protein has been found to be related to islet cell replication and/or beta cell regeneration, we compared the expression of the reg gene with that of chymotrypsinogen of exocrine origin and insulin of endocrine origin. We investigated the expression of the three pancreatic genes in the fetal pancreas during human development using dot-blot analysis. The levels of expression of the corresponding mRNAs did not appear to undergo great changes between the 17th and the 29th wk of gestation. Nevertheless, the fetal mRNA levels for reg and chymotrypsinogen were below that of the adult, with very low levels of reg gene expression in more than half of the studied pancreases. In contrast, the insulin mRNA levels were significantly higher in fetal than in adult pancreases, suggesting that insulin may function as a growth factor during fetal development. Our results indicate that no correlation between reg and insulin gene expression exists in the fetal pancreas during the developmental period studied but, on the contrary, such a correlation was present in the adult pancreas.

Adult↗
PubMed1996

Pit-1 gene expression in human lactotroph and somatotroph pituitary adenomas is correlated to D2 receptor gene expression.

The expression of the pituitary-specific transcription factor Pit-1 gene was analyzed in a series of 30 human lactotroph and somatotroph pituitary tumors. Northern blot analysis failed to reveal any quantitative differences in Pit-1 gene expression between somatotroph and lactotroph tumors, and reverse transcription-PCR analysis showed similar patterns of Pit-1 isoforms expression in both populations of tumors. The expression of the D2 receptor gene was subsequently analyzed in the same adenomas. In the prolactinomas, which presented with a variable sensitivity to dopamine agonist treatment, the intensity of the D2 receptor transcripts (2.8 kilobases) was variable and was related to the sensitivity to the dopamine agonist treatment. Notably, the individual D2 receptor messenger ribonucleic acid (mRNA) levels were highly correlated to the Pit-1 mRNA levels measured in the same tumors (r = 0.90; P < 0.0001). In the GH-secreting tumors, a significant expression of the D2 receptor gene was evidenced by Northern blot in all mixed somato-lactotroph adenomas and in some of the pure somatotroph adenomas; again, a positive correlation was found between D2 mRNA and Pit-1 mRNA levels (r = 0.68; P < 0.01). These results suggest the existence of mechanisms responsible for a coordinate control of Pit-1 and D2 receptor genes that remain to be determined.

Adenoma↗
PubMed1996

Unusual chromosome abnormalities in primary central nervous system lymphoma.

Primary central nervous system (PCNS) lymphoma is a relatively rare disease. The Epstein-Barr virus (EBV) has often been implicated in the development of lymphomas. Few cytogenetic. studies on PCNS lymphomas have been reported. We describe here an unusual case of PCNS B cell lymphoma, centroblastic polymorphic type without coexistent immune deficiency. The cytogenetic study showed unusual abnormalities: t(l;9) (q25;p21); del (6) (q14 q25), trisomy 12 and in addition one clone with trisomy 7 and loss of chromosome X. We did not observe any chromosome 14 abnormality, which is more commonly reported in PCNS lymphomas.

Aged↗
PubMed1996

Magnetic resonance spectroscopy and histological study of tubular aggregates in a familial myopathy.

31-P MR spectroscopy has been used to investigate metabolic events surrounding muscular contraction in a patient with an unusual myopathy characterized by clinical signs of muscle stiffness and swelling after prolonged exercise. Histological assays demonstrated a predominance of type II fibers with tubular aggregates. These structures had low calcium content although calcium-ATPase protein was present. Metabolic measurements were normal at rest except for the presence of a marked signal in the phosphodiester region which could reflect membrane abnormalities. Exercise-induced PCr consumption was in the normal range but the extent of the related intracellular acidosis was abnormally large. Kinetics of PCr and PCr/Pi ratio post-exercise recovery were delayed, but were likely to reflect the effect of the very low end-of-exercise pH rather than an aerobic deficiency. Finally, proton efflux from muscle to bloodstream, measured during the initial recovery period, was delayed, indicating altered mechanisms of proton handling. The most prominent metabolic abnormality recorded is the large glycogenolysis-induced pH decrease which might be linked to either abnormal activation of glycogenolysis and/or impaired proton and lactate handling within the muscle. The association between tubular aggregates and hyperacidosis is of interest but the exact causal relationship remains to be elucidated.

Adult↗
PubMed1995

A monoclonal antibody against Meningococcus group B polysaccharides used to immunocapture and quantify polysialylated NCAM in tissues and biological fluids.

Polysialylated isoforms of neural cell adhesion molecule (PSA-NCAM) are transiently expressed in many tissues during development and in discrete areas of the adult central nervous system. In pathological situations, they are expressed by poorly differentiated tumor cells of neuroectodermal origin and by regenerating muscle. An ELISA is introduced here to estimate the relative concentrations of PSA-NCAM expressed by tissues or released into biological fluids. In this double-sandwich assay, an anti-PSA antibody (anti-MenB) was adsorbed onto plastic plates and permitted the immunocapture of PSA-bearing molecules. It is demonstrated that these molecules are major NCAM. The second antibody was directed against an amino acid sequence shared by NCAM isoforms in several species. The standard curves were established using Nonidet P40 extracts of human or mouse embryonic brain known to be rich in PSA-NCAM. The sensitivity of the assay allows for quantitation of PSA-NCAM in muscle during regeneration and in small samples of cerebrospinal fluid from patients with medulloblastoma metastasis.

Animals↗
PubMed1995

Differential expression of cell adhesion molecules (CAM), neural CAM and epithelial cadherin in ependymomas and choroid plexus tumors.

A series of frozen specimens of 18 ependymomas and 7 choroid plexus tumors were examined for their expression of cell adhesion molecules, such as neural cell adhesion molecule (NCAM), its polysialylated isoforms (PSA NCAM), and epithelial (E-) cadherin, and of intermediate filament proteins, such as glial fibrillary acidic protein (GFAP) and cytokeratin, using various monoclonal and polyclonal antibodies. Normal choroid plexus and ependyma were taken as controls. Anti-E-cadherin immunoreactivity was observed on the basolateral part of most adult choroid plexus and benign choroid plexus papilloma cells. However, a small number of atypical papillomas and carcinoma cells showed anti- E-cadherin immunoreactivity throughout their cell surface membrane. NCAM were not expressed by adult choroid plexus and benign papilloma cells. Only a few cells expressed NCAM and PSA NCAM in developing choroid plexus, atypical papillomas and carcinomas. Cytokeratin expression was always observed in choroid plexus and their tumors; GFAP expression was variable from case to case. In contrast, ependymal cells and their tumors never expressed E-cadherin but strongly expressed NCAM. PSA NCAM was found in ependymomas exhibiting anaplastic features. All ependymomas strongly expressed GFAP and a few demonstrated slight expression of cytokeratin. These data suggest that, besides GFAP and cytokeratin, NCAM and E-cadherin are of potential diagnostic value in distinguishing choroid plexus tumors from ependymomas. E-cadherin and NCAM may play a role in the functional organization of normal choroid plexus and ependyma, respectively. In particular, incomplete or irregular anti-E-cadherin expression in choroid plexus tumors and PSA NCAM immunoreativity in ependymomas and choroid plexus tumors correlates with the emergence of anaplastic histological features.

Adolescent↗
PubMed1995

Do the suprasellar neurenteric cyst, the Rathke cleft cyst and the colloid cyst constitute a same entity?

Two cases of entirely suprasellar cysts are reported. Total surgical removal was performed in both cases. Pathological and immunohistochemical profiles were consistent with neurenteric cysts, Rathke's cleft cysts or colloid cysts and was also in keeping with an endodermal origin. It is now admitted that these three kinds of cysts share similar histological and immunohistological features. We propose an hypothesis of common embryological origin from endodermal remnants.

Adult↗
PubMed1995

Expression of developmentally regulated cytoskeleton and cell surface proteins in childhood spinal muscular atrophies.

Expression of some developmentally regulated cytoskeleton components (desmin, vimentin and myosin heavy chain isoforms) and cell surface proteins (including neural cell adhesion molecule (NCAM), its polysialylated (PSA) isoform and CD24) have been studied by immunohistochemical detection in a series of 23 infantile spinal muscular atrophies (SMA). According to the clinical classification established by Byers and Banker in 1961, 8 cases were type I SMA (Werdnig-Hoffmann's disease), 10 cases were type II (intermediate form), and 5 cases were type III (Kugelberg-Welander's disease). In 15 cases, the percentage of immunoreactive fibers with the various antibodies used has been quantified and the results correlated with clinical data. The aim of the study was to search for variations in the pattern of expression of the proteins to improve the accuracy of diagnosis and prognosis, and to gain an understanding of the pathological processes involved in SMA. The results showed that the pattern of expression of these cytoskeleton and cell surface proteins is abnormal in all types of SMA. However, it was strikingly different in type I and II SMA as opposed to type III. In type I and II SMA, strong NCAM and developmental myosin heavy chain (MHC) expression was observed in atrophic fibers. Numerous atrophic fibers co-expressed desmin and vimentin as well as slow and fast adult MHC. Very few of them expressed PSA NCAM, fetal MHC and CD24. In type III SMA, the number of fibers expressing NCAM, developmental MHC and co-expressing slow and fast adult MHC was low and virtually none of them expressed vimentin or desmin. These findings are in favor of a denervation process occurring very early in life, probably even in utero, in type I and II SMA and leading to a severe impairment of muscle fibers maturation. In contrast, in type III SMA, the process is initiated well after birth and affects mature muscle fibers. In all types of SMA, the ability of muscle fibers to regenerate is low, although some fibers may be reinnervated. Immunohistochemical data was not related to the patients follow-up and thus has no prognostic value.

Adolescent↗
PubMed1995

Suprasellar granular-cell tumour, presenting with intraventricular haemorrhage.

A case of suprasellar granular-cell tumour (GCT), presenting with intraventricular haemorrhage is described. The authors emphasize the exceptional character of spontaneous haemorrhage for a GCT, although haemorrhagic state during surgery has often been reported and may hinder total removal. Preoperative arteriography discloses a suprasellar blush in half of the cases. This facilitates the preoperative diagnosis. By taking special preoperative and operative precautions against haemorrhage complete removal can be carried out provided there is no encasement of the optic chiasm.

Cerebral Ventricles↗
PubMed1994

Association of deletion and homoplasmic point mutation of the mitochondrial DNA in an ocular myopathy.

The mitochondrial DNA of a 41 year old patient with ocular myopathy was explored. We found a deletion of 3540 base pair in about 50% of the mitochondrial genomes associated with a homoplasmic point mutation. The mutation at nucleotide pair 7444 converts stop codon AGA into lysine codon AAA (human mitochondrial genetic code). The synergistic effect between two point mutations has already been described in mitochondrial pathology but this is the first time that an association between a deletion and a point mutation is shown.

Adult↗
PubMed1994

Association of cerebral vasculitis with a lupus anticoagulant. A case with brain pathology.

The authors report the case of a sixty-five year old woman initially suffering from a thrombocytopenia. The patient was diagnosed as having an autoimmune disease with a lupus anticoagulant, positive antinuclear antibodies and negative anti-DNA antibodies. She then developed an encephalopathy which was fatal despite corticosteroids. Brain pathology revealed a vasculitis with some giant cells, evoking a granulomatous angiitis of the central nervous system. These clinical and biological features suggest a systemic lupus erythematosus with vasculitis or a primary granulomatous angiitis of the central nervous system. Taking into account the clinical manifestations and the presence of a lupus anticoagulant, we finally preferred to identify it as a primary antiphospholipid antibodies syndrome, despite absence of anticardiolipin antibodies. Contrary to thrombosis, vasculitis is rarely associated with an anticardiolipin antibody or a lupus anticoagulant. However, vasculitis in the course of primary antiphospholipid antibodies syndrome has been reported previously as in this case report.

Adrenal Cortex Hormones↗
PubMed1994

Expression of NCAM and its polysialylated isoforms during mdx mouse muscle regeneration and in vitro myogenesis.

In order to understand the mechanism of the muscular regenerative process which occurs in mdx mice, the expression of neural cell adhesion molecule (NCAM) isoforms and their polysialylated (PSA) derivatives were studied during the postnatal development of normal and mdx mice in relation to the stage of the regeneration of muscle fibres, in the quadriceps. NCAM expression was also examined during in vitro differentiation of satellite cells isolated from both mdx and normal muscles. The immunohistochemical and biochemical analyses were done using antibodies for the different isoforms. The data presented here suggest that before the onset of necrosis and regeneration, the expression of NCAM isoforms in the quadriceps of mdx mice was similar to normal mice. Later, NCAM and PSA-NCAM expression in mdx mice increased and was related to the muscular regenerative process, and the overall level of NCAM expression can be considered as a good index of muscle regeneration. Young regenerative fibres expressed NCAM and PSA-NCAM, while mature regenerative fibres, in which myonuclei remained centrally located, did not express either NCAM or the PSA isoforms. Therefore, in terms of NCAM expression, the fibres in mdx muscle with centrally located nuclei appeared similar to mature fibres found in normal adult muscle. A major form of 145 kDa and a minor form of 115 kDa were detected in mdx regenerative muscle. The 145 kDa NCAM was sialylated, as demonstrated by its sensibility to exoneuraminidase which generates a desialoform of 125 kDa, but not polysialylated since it was not recognized by the anti-MenB antibody, specific for PSA-NCAM. In contrast, the molecular forms of NCAM migrating as a broad band from 160 kDa to 220 kDa were identified as PSA-NCAM. The comparison of in vitro differentiation of normal and mdx satellite cells showed that the expression of NCAM isoforms by mdx cells was similar to that expressed by normal cells. Both our in vivo and in vitro data concerning NCAM expression show that regeneration in mdx mice does not differ from that observed in other necrotic diseases. In other words, NCAM is unlikely to be a dystrophin-associated molecule since lack of dystrophin does not affect its expression.

Animals↗
PubMed1994

Platelet-derived growth factor (PDGF) and receptor (PDGFR) expression in human meningiomas: correlations with clinicopathological features and cytogenetic analysis.

PDGFs and their receptors expression were examined in a series of 46 meningiomas by using specific monoclonal antibodies. The immunostaining was quantified by an image analyser and the results correlated with clinical and morphological data (histological type and grade). In addition, since the PDGFB chain is encoded by the c-sis proto-oncogene localized on chromosome 22 and because monosomy 22 has been frequently reported in meningiomas, PDGFs and PDGFRs expression have been correlated with cytogenetic analysis performed in 29 cases. The results demonstrate PDGF A and PDGF B expression in most meningioma specimens and co-expression of these growth factors in numerous cells. PDGF A and B immunoreactivity was related to histological grade. PDGFR beta expression was strong in almost all meningiomas whereas PDGFR alpha was low. PDGFR alpha expression was related to tumour location and grade and PDGFR beta to histological subtype only. The cytogenetic analysis was not related to PDGFB chain expression. Taken together these data further confirm PDGF and PDGFR expression in human meningioma; PDGF may exist as an heterodimer (AB) as well as its receptor. The lack of correlation between cytogenetic analysis and PDGF values, the low level of PDGFB in recurrent meningiomas suggests that it is unlikely that the c-sis proto-oncogene plays an important role in the genesis of meningiomas.

Adult↗
PubMed1994

Pit-1 gene expression in the human pituitary and pituitary adenomas.

The cellular basis for pituitary neoplasia is poorly understood. The POU domain protein Pit-1 is a pituitary-specific transcription factor involved in the generation, differentiation, and proliferation of three pituitary cell types: lactotrophs, somatotrophs, and thyrotrophs. In this study, we analyzed the expression of Pit-1 gene in a series of 15 different human pituitary tumors and compared it with that observed in normal tissue. Pit-1 transcripts, identical in size (2.4 and 4.5 kilobases) and sequence to those observed in normal tissue were evidenced in PRL-, GH-, and TSH-secreting tumors. Pit-1 is overexpressed (2.5- to 5-fold) in the PRL- and GH-secreting tumors, but to an extent consistent with the predominant cellular type of these adenomas. An isoform of Pit-1, with an insertion of 26 amino acids in the trans-activation domain as a result of alternative splicing, is also present in both normal and tumoral tissues. It is concluded that human pituitary tumorigenesis does not seem to be associated with a gross alteration of Pit-1 gene expression.

Adenoma↗