Search PubMed⌕ Search

Biomedical subjects

C Bouvier

Publications and source records attributed to C Bouvier.

At least 19 recordsLinked to original sources
PubMed2006

In vitro identification and functional characterization of glial precursor cells in human gliomas.

Human gliomas including astrocytomas and oligodendrogliomas are defined as being composed of neoplastic astrocytes and oligodendrocytes respectively. Here, on the basis of in vitro functional assays, we show that gliomas contain a mixture of glial progenitor cells and their progeny. We have set up explant cultures from pilocytic astrocytomas, glioblastomas and oligodendrogliomas and studied antigens that characterize glial lineage, from the precursor cells (glial restricted precursors and oligodendrocyte-type2-astrocyte/oligodendrocyte precursor cells expressing the A2B5 ganglioside) to the differentiated cells (oligodendrocyte and type-1 and type-2 astrocytes). All tumoral explants contain A2B5+ cells and can generate migrating cells with distinctive functional properties according to glioma subtypes. In pilocytic astrocytomas, very few migrating cells are dividing and can differentiate in type-2 astrocytes or towards the oligodendrocyte lineage. In glioblastomas, most migrating cells are dividing, express A2B5 or glial fibrillary acid protein (GFAP) and can generate oligodendrocytes and type-1 and type-2 astrocytes in appropriate medium. Oligodendroglioma explants are made by actively dividing glial precursor cells expressing A2B5 or PSA-NCAM. Only few cells can migrate and differentiation towards oligodendrocyte lineage does not occur. Isolated A2B5+ cells from both glioblastomas and oligodendrogliomas showed similar genetic alterations as the whole tumour. Therefore, pilocytic astrocytomas contain slowly dividing oligodendrocyte-type2-astrocyte/oligodendrocyte precursor cells in keeping with their benign behaviour whereas both glioblastomas and oligodendrogliomas contain neoplastic glial restricted precursor cells. In oligodendrogliomas, these cells are trapped in undifferentiated and proliferating state. The precursor cells properties present in gliomas give new insight into their histogenesis and open up new avenues for research in the field of gliomagenesis.

Adult↗
PubMed2005

Retrospective study of 77 patients harbouring lumbar synovial cysts: functional and neurological outcome.

BACKGROUND: Synovial cysts represent an uncommon and probably underestimated pathological entity of the degenerative lumbar spine. The authors report a retrospective analysis of the clinical presentation, radiological studies and operative findings in 77 patients surgically treated for symptomatic lumbar synovial cysts at their institution. MATERIALS AND METHOD: Between January 1992 and June 1998, a total of 77 patients presenting with symptomatic lumbar synovial cysts were operated on in the author's department. Operative procedure, complications, results and pathological findings were correlated with preoperative assessment. There were 41 men and 36 women with an average age of 63 years (range 44-90 years). RESULTS: On the basis of their symptom complex on presentation, two populations were identified: patients who presented with a single radicular pain (group I = 51 patients), and patients who presented with bilateral neurogenic claudication (group II = 26 patients). Neurological examination on presentation demonstrated motor deficit (12%), sensory loss (26%) and reflex changes (35%). Degenerative disc disease and facet joint osteoarthritis was a frequent finding in patients with pre-operative MRI. Facet joint orientation was >45 degrees in 76.6% of patients. Preoperative spondylolisthesis was found in 48% on radiological studies. All the patients were treated surgically with resection of the cyst. No fusion was performed as a first line procedure. However subsequent fusion was necessary in one patient who developed symptomatic spondylolisthesis. Mean follow-up period was of 45 months ranging from 18 to 105 months. Only one recurrence occurred during the follow-up period. An excellent or good functional outcome was seen in 97.4% of cases, and 89% of the patients with motor deficit recovered. CONCLUSIONS: Surgical resection of lumbar synovial cysts is an effective treatment associated with very low morbidity. Synovial cysts are associated with increased grade and frequency of facet joint asteoarthritis but not with increased grade or frequency of degenerative disc disease compared with patients without cysts. In the author's opinion, at the present time, there is no reliable criterion which allows the development of a symptomatic spinal instability to be predicted in patients with a preoperative spondylolisthesis and therefore fusion as a first line procedure is still debatable.

Adult↗
PubMed2004

Synthesis and adsorption on gold surfaces of a functionalized thiol: elaboration and test of a new nitroaromatic gas sensor.

A new type of sensor was built by synthesizing a long-chain thiol functionalized with an aromatic head group and grafting it onto a gold surface. The synthesis route is here described, together with the IR, MS, and RMN analysis of the new product. Adsorption of the latter onto gold was assessed by a combination of RAIRS and XPS data. Those reveal that a monolayer of thiol is adsorbed and oriented with the benzene groups toward the external part of the layer. Detection tests were performed in various atmospheres by QCM. The response shows good sensitivity to 2,4-dinitrotrifluoromethoxybenzene as a model of nitroaromatic compound.

Journal Article↗
PubMed2003

Sandostatin LAR (long-acting octreotide acetate) for malignant carcinoid syndrome: a 3-year experience.

BACKGROUND: Somatostatin analogues are the best therapy for controlling the symptoms of malignant carcinoid syndrome. Octreotide acetate given as subcutaneous injection up to three times daily, intramuscular Lanreotide injection given once per 1-2 weeks and monthly intramuscular Sandostatin LAR have demonstrated similar efficacy in short-term studies. AIM: To assess the long-term effect of Sandostatin LAR on the management of patients with malignant carcinoid syndrome. METHODS: This was a 3-year retrospective study. Twenty-seven patients were assessed with a median follow-up of 23 months. Thirteen patients were switched from subcutaneous octreotide and 14 patients were octreotide naive. All patients showed avid uptake on indium-111 octreotide imaging. RESULTS: Ten of the 13 patients previously on subcutaneous octreotide and 13 of the 14 patients who were octreotide naive had good symptom control on Sandostatin LAR. Over the period of follow-up, many patients showed progression of their tumour and required additional therapies. Patients expressed a preference for monthly intramuscular Sandostatin LAR as opposed to daily subcutaneous injections of octreotide. Although Sandostatin LAR was difficult to administer in certain instances, overall it was well tolerated. CONCLUSIONS: Sandostatin LAR provides good long-term symptomatic control in patients with malignant carcinoid syndrome; it is well tolerated and patients expressed improved satisfaction in their management.

Adult↗
PubMed2003

Nurse developments in neuroendocrine tumour management.

Nurse developments in the management of neuroendocrine tumours have changed significantly over the past three years. At the Royal Free Hospital we set up the nurse specialist role due to the expansion of patients being referred to the specialist unit, and the obvious need for a nursing input into their care. The nurse specialist can make a significant contribution within the context of a multidisciplinary team especially in the production of guidelines and policies to ensure and maintain high standards of practice, education for the patient, and the provision of expertise and security that the patient requires when diagnosed with a rare disease.

Humans↗
PubMed2003

[A retrospective study of 32 lumbar synovial cysts. Clinical aspect and surgical management].

We report a retrospective analysis of a series of 32 cases of lumbar synovial cysts. Clinically, two populations were identified: patients who presented radicular pain mimicking the clinical diagnosis of disk herniation (group I) and patients who presented neurogenic claudication consistent with a diagnosis of lumbar spinal stenosis (group II). The radiological work-up consisted in standard X-rays and CT-scan for all patients. MRI (magnetic resonance imaging) was performed in 14 patients. All the patients were operated on. The surgical technique consisted in foraminotomy for patients in group I and more or less extensive laminectomy for patients in group II. Functional outcome was marked by a significant improvement in 96.9% of the patients and those who presented a motor deficit recovered in 83% of the cases. Based on the findings in this series, we discuss the clinical aspects and the therapeutic management of this pathological entity.

Adult↗
PubMed2002

Congenital disseminated malignant rhabdoid tumor and cerebellar tumor mimicking medulloblastoma in monozygotic twins: pathologic and molecular diagnosis.

Malignant rhabdoid tumors are highly aggressive childhood tumors. Recently, all of the malignant rhabdoid tumors, whatever their location, have been related to the inactivation of the hSNF5/INI1 gene. A subset of cerebral tumors, associated with malignant rhabdoid tumors or isolated ones arising in siblings, showed similar molecular alterations. We report for the first time in monozygotic twins a congenital disseminated malignant rhabdoid tumor in one twin and a cerebellar tumor mimicking a medulloblastoma in the other. Molecular analysis revealed similar alterations for both tumors: a deletion of exon 7 of the hSNF5/INI1 gene in one allele, and a point mutation in the same exon in the other, suggesting a common genetic pathway. Analysis of constitutional DNA revealed a germline mutation. These findings are in favor of a common etiology for rhabdoid tumor and a subset of brain tumors developing in infancy.

Biomarkers, Tumor↗
PubMed2002

[Metastatic meningioma to the first thoracic vertebral body. A case report and review of the literature].

This report describes a case of metastatic meningioma involving the first thoracic vertebral body in a 63-year-old woman. The patient was treated surgically 10 years earlier for a benign meningioma of the right parietal vault. Local recurrence was diagnosed in 1992. Despite the gamma-knife radiosurgery, recurrence required surgical treatment in 1999. Histological findings were compatible with atypical meningioma (grade II WHO). One year later, the patient presented left C8 cervicobrachial neuralgia. Investigation led to discovery of a D1 tumor that was a metastasis of the atypical intracranial meningioma. A resection of the vertebral T1 body with C7-T2 osteosynthesis was performed with an excellent recovery and no postoperative complication.

Brachial Plexus Neuritis↗
PubMed2002

[Pollution of the groundwater in the city of Niamey, Niger].

We conducted a study on chemical and bacteriological groundwater pollution in Niamey, a Sahelian city of some 700,000 inhabitants. A total of 22 wells and 24 bore-holes were selected on a geological and socio-economic basis. The superficial aquifers, located on each bank of the River Niger and connected to the wells, presented high levels of oxidizable nitrogen and bacteriological pollution (coliform and faecal Streptococcus) which make the water unfit for human consumption. The deep aquifer, which supplies pumps, was also polluted but to a lesser degree. Faecal pollution increased after the rainy season. The lack of sanitation in Niamey and the seepage of polluted matters from the superficial layers could explain this pollution. Eventually, the use of the groundwater could increase and constitute a major health risk for the majority of the inhabitants of Niamey.

Colony Count, Microbial↗
PubMed2000

Tubular lesions determine prognosis of IgA nephropathy.

To assess the prognostic value of histological classification for renal outcome, we did a multivariate analysis of 194 patients with immunoglobulin A (IgA) nephropathy between 1985 and 1995. We also evaluated semiquantitative scales of tubular lesions and vessel lesions. At the time of the biopsy, 65 patients (33.5%) had chronic renal failure. At the end of the follow-up, 33 patients (17%) required hemodialysis. The mean age of the patients was 37.8 +/-18.9 years with predominance of men (sex-ratio: 3.12). Patients were followed-up for a mean of 43.2 +/- 37.2 months. Univariate analysis showed that hypertension (P < 10(-4)), nephrotic syndrome (P = 0.01), and crescents (P = 0.02) were significant in predicting renal failure, unlike subendothelial topography of IgA deposits (P = 0.05) and proteinuria (P = 0.05). Hematuria was a protective factor (P = 0.03). Multivariate analysis showed that tubular grade 2 (relative risk [RR], 5.5) and tubular grade 3 (RR = 28.8) were the best factors to predict chronic renal failure. The histological classification of Haas was significant in the univariate analysis, but not in the multivariate analysis. Tubular grading predicted renal outcome better than did the other histological parameters.

Adolescent↗
PubMed2000

Adult mesoblastic nephroma.

We report a case of asymptomatic mesoblastic nephroma in a 54-year-old woman. The tumor showed immunohistochemical reactions similar to developing nephrons. Electron microscopy showed immature tubules with numerous intracytoplasmic intermediate filaments. Recent studies support the concept of pathogenesis of the mesoblastic nephroma originating from collecting ducts. However, this case exhibited a complex pattern of antigenic expression not restricted to the collecting ducts, but including the glycoprotein CD24 and the neural cell adhesion molecule (NCAM). The following differential diagnoses will be discussed: benign mixed epithelial and stromal tumor, metanephric adenoma, and nephrogenic adenofibroma.

Adenofibroma↗
PubMed2000

Clinicopathologic growth factors in vestibular schwannomas: a morphological and immunohistochemical study of 69 tumours.

Tumour growth of vestibular schwannomas is still difficult to predict. The aim of our study was to determine whether any defined histopathological feature was correlated with the clinical course. We did a retrospective study with 69 paraffin-embedded tumours to establish whether the number of vessels, blood cells extravasation or degree of inflammation, all semi-quantitatively assessed, could be indicative of potential of growth. An immunohistochemical study was also performed with an endothelial marker CD34, the leukocyte common antigen CD45 and the estrogen and progesterone hormone receptors. All these parameters were correlated with patient's age, duration of symptoms (d), with a clinical growth index (CLI = tumour size/d). No clinical parameters proved to be predictive of tumour growth. Tumour size was significantly (p = 0.01) related to the number of vessels and we found a significant relationship between the clinical growth index (CLI) and total number of vessels, especially when duration of symptoms lasted less than 1 year (p < 0.001). However, we found no relationship between duration of symptoms or CLI and CD34 index. The degree of inflammation was significantly correlated (p = 0.007) with duration of symptoms when it lasted more than 1 year. The CD45 index and the semi-quantitative evaluation of the inflammation were well correlated (p = 0.001). No estrogen receptors antigenic site was detected and only seven tumours expressed progesterone receptor in a few cells without any significant clinical value. These results suggest that vessel density is determinant for sporadic acoustic neuroma growth especially for a short clinical course.

Adult↗
PubMed2000

Chronic hepatitis C virus infection associated with a generalized granuloma annulare.

We report the first case of generalized granuloma annulare occurring in a 65-year-old woman who was chronically infected with hepatitis C virus. Granuloma annulare totally regressed during alpha-interferon treatment. As chronic hepatitis C virus infection is frequent, a serodiagnosis would be of interest in patients who have generalized granuloma annulare. A link between these 2 diseases may be strongly suspected.

Aged↗
PubMed2000

[The pectoralis myofascial flap in oropharyngeal and pharyngolaryngeal reconstruction in salvage surgery].

BACKGROUND: The pectoralis major myofascial (PMMF) flap is rapidly mobilized, reliable in a number of clinical situations calling for vascularized soft tissue coverage in the head and neck. Salvage surgery after radiation failures produce salivary fistula, skin flap necrosis, vascular rupture. Use of PMMF improves healing in such cases. METHODS: A retrospective review performed at the university hospital, Marseille, between August 1987 and August 1999, was undertaken in two groups of salvage surgery. Groupe 1: protection of great vessels and fistula prevention after total laryngectomy (TL) and pharyngolaryngectomy (PL). Groupe 2: intra oral and pharyngeal defects reconstruction. Outcomes were classified in three types: type 1 - no complications; type 2 - delayed healing; type 3 - complicated healing. In groupe 2, in six cases the amount of flap contraction was analysed by C.T. scan. RESULTS: 83 PMMF was performed. Groupe 1, 57 cases (TL 28 cases, PL 26 cases); groupe 2, oral cavity défect 9 cases; oropharyngeal défects; 17 cases. There was no flap necrosis or vascular rupture. The donor site complications rate was 9.2%. The overall complications follow up was; groupe 1; type 1: 66%; type 2: 32%; type 3: 2%. In the groupe 2, type 1: 81%; type 2: 19%; type 3: 0%. The flap contracture was 30%. The use of PMMF in salvage surgery must be indicated in all cases after TL or PL, and is an excellent alternative from soft tissue coverage of oropharyngeal defects.

Adult↗
PubMed1999

Cerebellar papillary meningioma in a 3-year-old boy: the usefulness of electron microscopy for diagnosis.

We report one case of papillary meningioma located in the posterior fossa in a 3-year-old boy. Despite a gross total resection, a major recurrence occurred 6 months later that was operated on. Eight months later, another recurrence was observed with intracranial metastases and dissemination throughout the cerebrospinal fluid. The tumor had a papillary architecture more obvious in the recurrence. Areas of necrosis were numerous. Tumor cells had large clear atypical nuclei. Many mitotic figures were seen and Ki-67 labeling index was high. The tumor cells were immunoreactive for vimentin and polysialylated neural cell adhesion molecule only, ruling out a diagnosis of ependymoma or medulloblastoma. Diagnosis of meningioma was done by electron microscopy, which showed interdigitating cytoplasmic processes and cell junctions. Cytogenetic study revealed unusual karyotypic abnormalities.

Cerebellar Neoplasms↗