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Biomedical subjects

B Pasquier

Publications and source records attributed to B Pasquier.

At least 37 records · Page 2Linked to original sources
PubMed2000

Immunohistochemical expression of WT1 by desmoplastic small round cell tumor: a comparative study with other small round cell tumors.

Desmoplastic small round cell tumors (DSRCTs) present a reciprocal chromosomal translocation, t(11;22)(p13;q12), that results in fusion of Ewing's sarcoma and Wilms' tumor (WT1) genes. The authors evaluated 15 DSRCTs and 71 other tumors often considered in the differential diagnosis for immunoreactivity using a polyclonal antibody directed against the WT1 part of the chimeric protein resulting from this translocation. WT1 immunostaining was performed on paraffin material using the WT(C-19) antibody after heat-antigen retrieval. All the DSRCTs (15 of 15, 100%) demonstrated strong WT1 nuclear immunoreactivity. Ten of 14 nephroblastomas (71%) disclosed WT1-positive nuclei in accordance with the staining reported by others, and rare and focal nuclear positivity was detected in two of 17 rhabdomyosarcomas. WT1 immunoreactivity was not observed in Ewing's sarcoma/primitive neuroectodermal tumors (zero of 21, 0%), neuroblastomas (zero of 17, 0%), or rhabdoid tumors of the kidney (zero of two, 0%). In nephroblastoma, differential diagnosis with DSRCT was not difficult: Clinical and morphologic data are not similar for these two entities. The current study validates WT1 immunoreactivity as a useful marker to separate DSRCT from other small round cell tumors.

Abdominal Neoplasms↗
PubMed2000

Silicone lymphadenopathy mimicking a lymphoma in a patient with a metatarsophalangeal joint prosthesis.

With lymph node enlargement, the possibility of a malignant process such as metastatic carcinoma or lymphoma needs to be excluded. This report describes a 47 year old woman with inguinal lymph node enlargement initially suspicious for lymphoma. Fine needle aspiration findings favoured reactive hyperplasia, but a malignant process could not be excluded. The final histological diagnosis was a foreign body granulomatous inflammatory response as a result of regionally disseminated silicone particles from an over looked metatarsophalangeal joint prosthesis. Because of the large number of joint prostheses world wide, it should be kept in mind that migration of wear particles can create granulomatous inflammation and node enlargement.

Diagnosis, Differential↗
PubMed1999

Alternative endocytic pathway for immunoglobulin A Fc receptors (CD89) depends on the lack of FcRgamma association and protects against degradation of bound ligand.

IgA is the most abundant immunoglobulin in mucosal areas but is only the second most common antibody isotype in serum because it is catabolized faster than IgG. IgA exists in monomeric and polymeric forms that function through receptors expressed on effector cells. Here, we show that IgA Fc receptor(s) (FcalphaR) are expressed with or without the gamma chain on monocytes and neutrophils. gamma-less FcalphaR represent a significant fraction of surface FcalphaR molecules even on cells overexpressing the gamma chain. The FcalphaR-gamma2 association is up-regulated by phorbol esters and interferon-gamma. To characterize gamma-less FcalphaR functionally, we generated mast cell transfectants expressing wild-type human FcalphaR or a receptor with a point mutation (Arg --> Leu at position 209) which was unable to associate with the gamma chain. Mutant gamma-less FcalphaR bound monomeric and polymeric human IgA1 or IgA2 but failed to induce exocytosis after receptor clustering. The two types of transfectant showed similar kinetics of FcalphaR-mediated endocytosis; however, the endocytosis pathways of the two types of receptor differed. Whereas mutant FcalphaR were localized mainly in early endosomes, those containing FcalphaR-gamma2 were found in endo-lysosomal compartments. Mutant gamma-less FcalphaR recycled the internalized IgA toward the cell surface and protected against IgA degradation. Cells expressing the two forms of FcalphaR, associated or unassociated with gamma chains, may thus have differential functions either by degrading IgA antibody complexes or by recycling serum IgA.

Antigens, CD↗
PubMed1999

[Neurologic involvement in sarcoidosis. Federation of Systemic Diseases of Grenoble].

OBJECTIVE: Study the incidence, clinical features, prognosis and diagnostic and therapeutic strategies in neurological lesions of sarcoidosis. PATIENTS AND METHODS: The 207 cases of sarcoidosis followed at the Grenoble University Hospital between 1992 and 1998 were identified. After collecting data, the cases with neurological signs related to sarcoidosis were selected. RESULTS: Sixteen patients (7.7%) had neurosarcoidosis. Ten had central nervous system involvement, with 5 reaching the hypothalamus and pituitary glands, 2 cases of meningoencephalitis, 2 pseudotumoral lesions, and 1 bitemporal lesion. Six had peripheral nervous system involvement, 3 had facial palsies and 3 had neuropathies. Laboratory tests were not contributive to diagnosis. Ten magnetic resonance imaging series were pathological out of 11 performed. Three central nervous system biopsies were obtained. Corticosteroid therapy was the most frequent treatment. For hypothalamic and pituitary dysfunction, the only treatment was substitutive hormone therapy. The course was favorable in 11 cases, stable in 4 cases. Symptoms worsened despite treatment in only 1 case. CONCLUSION: The incidence of neurosarcoidosis may be much higher than is generally realized. The association of suggestive MRI signs, and clinical and laboratory findings evoke the diagnosis. Brain biopsy remains necessary for the pseudotumoral forms and the primitive neurological forms.

Adolescent↗
PubMed1999

Elastic reinforcement and thickness of the joint capsules of the lower cervical spine.

Mechanical studies have shown the major strength of the joint capsules of the lower cervical spine, especially in its ventrolateral part. The aim of this study was to examine the structure of the joint capsules in order to discover if there is a correspondence between biomechanical properties and descriptive anatomy. Ten transverse sections and 4 sagittal sections obtained from 6 cadavers were observed under light microscopy at X 25 to X 250 magnification. Standard stains and specific elastic fiber stain were used for histologic preparation. The data were the thickness of the joint capsules in the different quadrants, and the topography and direction of the elastic fibers. The results showed that the ventrolateral part of the joint capsules is thick and reinforced by oblique elastic fibers. The dorsal part is thin. The authors suggest that the descriptive anatomy of the joint capsules confirms their mechanical properties. They note that the role of the ventrolateral part is supplemented by that of the posterior longitudinal ligament for the stability of the functional cervical spinal unit.

Aged↗
PubMed1999

Digestion and absorption of 2 fat emulsions with different droplet sizes in the human digestive tract.

BACKGROUND: The extent of fat emulsification affects the activity of digestive lipases in vitro and may govern digestion and absorption of dietary fat. OBJECTIVE: We investigated the effect of the fat globule size of 2 enteral emulsions on fat digestion and assimilation in humans. DESIGN: Healthy subjects received intragastrically a coarse (10 microm) and a fine (0.7 microm) lipid emulsion of identical composition in random order. Gastric and duodenal aspirates were collected throughout digestion to measure changes in fat droplet size, gastric and pancreatic lipase activities, and fat digestion. Blood lipids were measured postprandially for fat assimilation. RESULTS: Despite an increase in droplet size in the stomach (2.75-6.20 microm), the fine emulsion retained droplets of smaller size and its lipolysis was greater than that of the coarse emulsion (36.5% compared with 15.8%; P < 0.05). In the duodenum, lipolysis of the fine emulsion was on the whole higher (73.3% compared with 46.3%). The overall 0-7-h plasma and chylomicron responses given by the areas under the curve were not significantly different between the emulsions, but the triacylglycerol peak was delayed with the fine emulsion (3 h 56 min compared with 2 h 50 min). CONCLUSIONS: Fat emulsions behave differently in the digestive tract depending on their initial physicochemical properties. A lower initial fat droplet size facilitates fat digestion by gastric lipase in the stomach and duodenal lipolysis. Overall fat assimilation in healthy subjects is not affected by differences in initial droplet size because of efficient fat digestion by pancreatic lipase in the small intestine. Nevertheless, these new observations could be of interest in the enteral nutrition of subjects suffering from pancreatic insufficiency.

Absorption↗
PubMed1999

MR spectroscopy of bilateral thalamic gliomas.

This study reports the MR spectroscopic patterns of two patients with bithalamic glioma. In one patient, phosphorus (31P) MR spectroscopy was performed. In both patients, the proton MR spectroscopic scans showed an increased creatine-phosphocreatine peak in the tumor. In the patient who underwent 31P-MR spectroscopy, an increased phosphocreatine peak was also observed. This group of thalamic tumors may be distinguished from other gliomas clinically, radiologically, and metabolically.

Adult↗
PubMed1998

Foreign body histiocytosis reaction after hip replacement with concomitant metastatic adenocarcinoma in the same lymph node.

Infiltration of regional lymph nodes by macrophages has been shown after total joint arthroplasty. These pelvic lymph nodes were obtained most often from patients during staging procedures for carcinoma and may be a diagnostic pitfall in the frozen section diagnosis of nodal metastasis. We report an unusual case of association in the same lymph node between histiocytosis and prostatic carcinoma metastasis. Histiocytosis was caused by wear debris from two different prostheses. Inductively coupled plasma mass spectrometry verified this diagnosis.

Adenocarcinoma↗
PubMed1998

Desmoplastic small round cell tumor: RT-PCR analysis and immunohistochemical detection of the Wilm's tumor gene WT1.

Desmoplastic small round cell tumor is an aggressive neoplasm first described in 1991. Recently, a reciprocal translocation t(11;22)(p13;q12) has been characterized by conventional cytogenetic studies and molecular analysis. This translocation involves the Ewing's sarcoma gene on chromosome 22 and the Wilms' tumor gene WT1 on chromosome 11. The chimeric transcript corresponding to the fusion gene could be detected by the reverse transcriptase-polymerase chain reaction (RT-PCR). Using an anti-WT1 antibody, the WT1 part of the putative chimeric protein could be recognized by immunohistochemistry. We describe two well-characterized cases of intraabdominal desmoplastic small round cell tumor in two male patients aged 14 and 28 with both RT-PCR analysis and immunostaining for WT1. In this report, we insist on the necessity to increase the RT-PCR analysis in DSRCT in order to obtain a precise differential diagnosis. In addition, WT1 immunostaining may serve as a useful diagnostic marker for DSRCT.

Abdominal Neoplasms↗
PubMed1998

Immunocytochemical investigation on dysplastic human tissue from epileptic patients.

In this report we describe three patients with developmental cortical abnormalities (generally referred as cortical dysplasia), revealed by MRI and operated on for intractable epilepsy. Tissue, removed for strictly therapeutic reasons, was defined as the epileptogenic area by electroclinical data and stereo EEG (SEEG) recordings. Tissue samples were processed initially for histology, and selected sections were further processed for immunocytochemical investigation in order to determine whether the region of cortical dysplasia was co-extensive with the epileptogenic area. In two patients with nodular heterotopia, disorganized aggregates of neurons (as revealed by neuronal cytoskeletal markers) were found within the nodules. Both pyramidal and local circuit neurons were present in the nodules, but no reactive gliosis was present. When nodules reached the cortex, the cortical layers were disrupted. In the patient with localized cortical dysplasia, a complete disorganization of the cortical lamination was found, and numerous neurons were also present in the white matter. Disoriented pyramidal neurons weakly labelled with cytoskeletal neuronal markers were also present but no cytomegalic cells were found. One of the patients with nodular heterotopia underwent only partial resection of both the 'epileptogenic area' and of the lesion; this patient still presents with seizures. The other patient with nodular heterotopia is seizure-free after a complete lesionectomy and excision of the epileptogenic area. The third patient, with focal cortical dysplasia, had two surgeries; she became seizure-free only after the excision of the epileptogenic area detected by SEEG recording. The present data suggest that the dysplastic areas identified by MRI should not be considered as the only place of origin of the ictal discharges. From the neuropathological point of view, the focal cortical dysplasia can be considered as a pure form of migrational disorder. However, the presence of large aggregates of neurons interspersed within the white matter, in the subcortical nodular heterotopia, suggests that a defect of neuronal migration could be associated with an exuberant production of neuroblasts and/or a disruption of mechanisms for naturally occurring cell death.

Cerebral Cortex↗
PubMed1998

[Cytology of fluids of articular puncture].

Cytologic examination of synovial fluid has been shown to be useful in the diagnosis of various joint diseases. Few pathologists are proficient in the interpretation of the occasional synovial fluids that most cytology laboratories receive. The majority of the aspirated synovial fluids are sent only for bacterial culture and valuable information from the cytologic examination is missed. We describe how pathologists should perform analysis of these fluids and what kind of information they can provide to the physician.

Cytodiagnosis↗
PubMed1997

Malignant peripheral nerve sheath tumor arising in a "de novo" ganglioneuroma: a case report and review of the literature.

A case of a "de novo" ganglioneuroma showing a large area of malignant peripheral nerve sheath tumor (MPNST) is described. The tumor arose in an 11.5-year-old girl with neither stigmata nor family history of von Recklinghausen's neurofibromatosis. In addition, the patient had no previous history of a neuroblastoma or radiation therapy. This report provides new evidence that, although rare, the spontaneous development of an MPNST in a benign ganglioneuroma can occur. Immunohistochemical and electron microscopy studies supported the finding that the spindle cell component was of nerve sheath origin.

Child↗
PubMed1997

[Primary bone leiomyosarcoma. Anatomo-clinical case with immunohistochemistry study and review of the literature].

We describe a primary leiomyosarcoma arising in the proximal part of the right tibia of a 38-year-old man. The diagnosis was confirmed by immunohistochemistry (positivity of tumor cells for alpha smooth muscle actin, HHF 35, desmin and vimentin). To the best of our knowledge, this is the 49th documented case of primary leiomyosarcoma of bone outside the facial skeleton. This exceptional tumor arises more commonly in adults (mean age: 53 years) and in the long bones of lower limbs, near the knee. The most frequent symptom is pain with or without swelling or fracture. Radiological findings invariably consist of a non specific osteolytic lesion. Although their histological appearance does not differ from that of extraosseous leiomyosarcomas, their diagnosis is difficult and often requires immunohistochemical and/or ultrastructural study. From a practical point of view, the diagnosis of primary leiomyosarcoma of bone also requires an intensive review of the case history and of previous pathology. This is necessary in order to eliminate an extraosseous primary site (mainly in uterus, gastrointestinal tract and soft tissues). As well as clinicopathological features, modes of treatment and results are also reviewed.

Adult↗