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Biomedical subjects

M Pluot

Publications and source records attributed to M Pluot.

At least 37 records · Page 2Linked to original sources

Kinetics study of the localization and quantitation of target antigens of immunoglobulin a antibodies in acquired and congenital toxoplasmosis.

The cellular distribution (localization and quantitation) of the target parasite's antigens in the tachyzoite along the IgA kinetics was determined in the course of acquired toxoplasmosis and congenital toxoplasmosis. In the case of acquired toxoplasmosis, throughout the IgA kinetics a correlation was noted between the membrane and submembrane immunolabeling and the results of the immunocapture and enzyme-linked immunosorbent assay IgA (ELISA-A) tests. The rhoptries' immunolabeling remained higher. The immunolabeling evolution and the results of the immunology tests were not closely related to the treatment (Rovamycin). From the congenital toxoplasmosis cases it was observed that membrane immunolabeling correlated with the results of the serology tests and with the treatment (Fansidar). The rhoptry antigens were recognized throughout the IgA kinetics; even when the serology tests became negative, immunolabeling persisted. Rhoptries appeared as secretory organelles of antigens recognized during acute, chronic, and congenital stages of Toxoplasma infection.

Animals↗

[Granular-cell tumor: review of the literature apropos of a case of bronchial site].

Abrikossoff's tumor, also called granular cell tumor, is an uncommon condition, generally benign, which can affect every organ and specially skin and tongue. The authors report an observation of a bronchial tumor and review the literature. Possible relapse after treatment, locally or everywhere in the body, may occur as local or regional complication that may necessit heavy surgery. It appears that a benign tumor can have macroscopic and even microscopic aspect of malignancy, when real malignant tumors are extremely rare. Wide excision still remain current treatment of Abrikossoff's tumor. Endoscopic methods are an interessant and less invasive alternative to treat some deep tumors.

Adult↗

Early neonatal diagnosis of congenital toxoplasmosis: value of comparative enzyme-linked immunofiltration assay immunological profiles and anti-Toxoplasma gondii immunoglobulin M (IgM) or IgA immunocapture and implications for postnatal therapeutic strategies.

Diagnostic strategies for congenital toxoplasmosis have changed profoundly in recent years. Immunological diagnostic methods, long considered disappointing, can now be used at a very early stage. Over a 3-year period, 1,050 infants at risk of congenital toxoplasmosis (born to 1,048 mothers infected during pregnancy) were monitored for a minimum of 12 months and a maximum of 7 years. More than 6,000 serum specimens were analyzed by comparative mother-infant immunological profiles (CIPs) based on an enzyme-linked immunofiltration assay (ELIFA) and an immunocapture method for the detection of specific immunoglobulin M (IgM) and IgA. IgG antibodies were also titrated. One hundred three cases of congenital toxoplasmosis were demonstrated. The CIP-ELIFA method had a better diagnostic yield (sensitivity, 90%) than specific IgM and/or IgA detection by immunocapture assay (sensitivity, 77%). By using a combination of these tests, congenital infection was diagnosed in the first month and the first 3 months of life in 90 and 94% of infants with toxoplasmosis, respectively, with a specificity of 99.8% and a positive predictive value of 99% at 8 months of age. This dual diagnostic approach (ELIFA and IgM-IgA immunocapture) is highly efficient and has important implications for therapy. Indeed, early postnatal diagnosis based on objective evidence enables therapy with pyrimethamine-sulfadoxine to be started immediately for 24 months, while spiramycin (which used to be given preventively for 9 to 12 months to all infants at risk) can be stopped after the first 3 months of life.

Animals↗

Quantitative cytology and thyroperoxidase immunochemistry: new tools in evaluating thyroid nodules by fine-needle aspiration.

Fine-needle aspiration (FNA) of cold thyroid nodules is proposed to be the most useful diagnostic test for deciding which patients need surgery. A retrospective study of standard cytology (SC) performed in 776 patients who had been operated on, showed a sensitivity of 94% and a specificity of 80%. Quantitative cytology (QC) was carried out with a cell image analyzer, which classified the cases as benign or not benign. In 87 cases, sensitivity and specificity of QC alone were 100 and 76%. When SC and QC were combined, there were no false negative reports. A new monoclonal antithyroperoxidase (TPO) antibody (MoAb47) was tested. The sensitivity and specificity of TPO alone were 97 and 81%. When SC and TPO were combined, specificity rose 90%. As adjuncts to SC, QC and TPO represent useful tools for selecting patients for surgery.

Biopsy, Needle↗

[Leiomyosarcoma of the inferior vena cava. Apropos of a new case].

A leiomyosarcoma was diagnosed in the mid portion of the inter-renal inferior vena cava. Survival was long (6 years) but required 14 reoperations to remove metastases. During the first operation, vascular integrity was reestablished with a cava-cava prosthesis after exeresis of the upstream cava without removal of the left renal vein ostium. The right renal vein was sectioned and directly implanted onto the prosthesis. The pathology report confirmed the diagnosis of leiomyosarcoma with multiple metastases presenting cytonuclear anomalies which worsened with time.

Blood Vessel Prosthesis↗

Molecular characterization of Charcot-Marie-Tooth patients in 15 pedigrees from France.

Molecular characterization of Charcot-Marie-Tooth patients in 15 pedigree from France: We collected 15 Charcot-Marie-Tooth (CMT) pedigrees from France. DNA polymorphisms analysis by Southern blotting with probes at the D17S122 locus demonstrated 17p duplication in three CMT1a families and in one sporadic case. Two families affected by CMT2 showed no evidence of the duplication.

Blotting, Southern↗

Subcellular localization and quantitative analysis of Toxoplasma gondii target antigens of specific immunoglobulins G, M, A, and E.

The target antigens of specific immunoglobulins G, M, A, and E from patients with acquired acute toxoplasmosis were determined using immunocytochemistry. The relative repartition of these antigens in four cellular compartments of Toxoplasma (membrane complex, apical area, rhoptries, and dense granules) was quantitatively evaluated. Rhoptry antigens mainly react positively with IgA. Membrane, submembrane area (membrane complex), and rhoptry antigens are immunodominant for IgA and IgM. Apical area antigens are recognized by IgM two times more than IgG and IgA. IgE recognized only rhoptry antigens. The localization of pathogenetically antigenic components and their identification by the immune system appeared to be of importance for selection of immunodominant or recombinant antigens. Such localization would improve laboratory diagnosis of serious congenital toxoplasmosis or in immunocompromised patients with toxoplasmic complications after cyst reactivation.

Animals↗

Epstein-Barr virus-associated primary malignant lymphomas of the pleural cavity occurring in longstanding pleural chronic inflammation.

Primary pleural non-Hodgkin's lymphomas (NHLs) have been described mostly in Japan and occasionally in western countries. We report three cases occurring in nonimmunocompromised patients demonstrating close similarities to the Japanese cases. These lymphomas occurred more than 20 years after thoracoplasty for the treatment of pleural or pulmonary tuberculosis. They were all high grade lymphomas of B phenotype (two immunoblastic with plasmocytoid differentiation and one immunoblastic with anaplastic large cells). In situ hybridization (ISH) detected small nuclear RNAs encoded by Epstein-Barr virus (EBERs) in most lymphomatous cells in all cases. This suggests a link between primary pleural lymphoma and the longstanding chronic inflammation, which could favor a clonal evolution of Epstein-Barr virus (EBV)-infected B cells through the production of growth factors or immunosuppressive cytokines produced by inflammatory cells.

Aged↗

Subcellular calcium localization in Toxoplasma gondii by electron microscopy and by X-ray and electron energy loss spectroscopies.

The localization of calcium in Toxoplasma gondii tachyzoites was studied at the ultrastructural level, with a cytochemical pyroantimonate precipitation method (PA) and controlled by EGTA chelating and EDX and EELS microanalyses. Appropriate conditions for material preparation, fixation and embedding, were defined. The proportion of precipitates that were either free or inside vacuoles and their distribution inside Toxoplasma appeared to be PA dose-dependent. Precipitation mainly occurred in the anterior pole of the Epon-embedded tachyzoites. EDX and EELS analyses showed that out of 30 PA precipitates inside tachyzoites, 78% contained Ca. In Melamine sections, 96% of the tachyzoites had intracellular precipitates and the membrane complex was stained; 25% of the tachyzoites inside host cells contained PA-Ca precipitates, but most of them were retained in the reticular network of the parasitophorous vacuole. Melamine embedding appeared to improve the preservation of calcium pyroantimonate precipitates.

Animals↗

Quantitative immunolocalization of four immunodominant antigens of Toxoplasma gondii.

Ultrastructural localization of four immunodominant antigens of Toxoplasma gondii was investigated quantitatively on thin sections and replicas by an immunogold technique using four monoclonal antibodies (Mab). On immunoblot Mab IV47, GII9, II38 and IE10 identified proteins of 28, 30, 45 and 66-70 kDa, respectively. Use of digital image analyzer and a semi-automatic procedure developed by us, the patterns of label distribution were compared in three cell structures: cell surface, submembrane area and rhoptries. On the whole cell surface, protein P28 and P30 were 2.5 and 4 times more abundant than P66-70 respectively. The protein P28 was essentially concentrated in the submembrane area with a labeling of 195.4 +/- 46.7 gold particles/microns 2 that follows a decreasing gradient from this area to the cell centre. In the rhoptries, all four antigens were detected, P45 and P66-70 being major with a labeling of 97.1 +/- 31.1 gold particles/microns 2 and 155.1 +/- 39.3 gold particles/microns 2 respectively. The results support the hypothesis that rhoptries are the essential site for antigen storage.

Animals↗

[Invasive adenocarcinoma with epidermoid carcinoma on the site of bladder exstrophy. Histochemical and immunocytochemical study].

To date, one hundred and ten cases of malignant neoplasms arising from untreated bladder exstrophy have been reported. We describe another case of uncorrected bladder exstrophy with invasive adenocarcinoma and in situ squamous carcinoma discovered in a 51 year old woman. Postoperative radiotherapy was performed after cystectomy with nephroureterectomy and hysterectomy. The neoplastic samples were investigated by mucin histochemistry and immunocytochemistry. The epithelium lining the tumor villi and the surrounding mucosae was colonic with mucin histochemistry and reacted to anti KL1, EMA and ACE antibodies. These features were those of colonic and vesical adenocarcinomas. Although early vesical reconstruction is the best oncologic prevention, patients with bladder exstrophy run the risk of sigmoid adenocarcinoma after cystectomy and urinary diversion including ureterosigmoidostomy.

Adenocarcinoma↗

[Acute malignant myelofibrosis. Report of 3 cases].

This report describes three cases of acute malignant myelofibrosis characterized by pancytopenia, absence of splenomegaly, bone marrow fibrosis with an immature cell proliferation and rapidly fatal outcome. The authors investigated the origin of blast cells with the use of immunohistochemical markers on paraffin embedded material with anti-factor VIII, BNH9 and anti-lysozyme. They studied the expression of megakaryoblastic, erythroblastic and myeloblastic differentiation in these cells. They demonstrated the heterogeneity of blast cells which are capable of differentiating along the three hematologic cell lines. The morphometric study showed the mutilating or systematized character of myelofibrosis. The increase in reticulin fiber density compared with normal bone marrow was not significantly different from two other types of myelofibrosis. It would be interesting to correlate a quantitative parameter with the course of this disease in order to evaluate the prognosis and the treatment.

Acute Disease↗

[Value of the nucleolar organizers (AgNOR) in brain gliomas].

The aim of the study was to evaluate the feasibility and possible contribution of silver stained nucleolar organizer regions (AgNORs) to prognostic considerations, in a series of 55 supratentorial gliomas: eight grade II astrocytomas, twelve grade III astrocytomas, thirty grade IV astrocytomas, two glioblastomas, one anaplastic oligodendroglioma, one oligodendroglioma and one ependymoma. Silver NORs (AgNORs) were demonstrated according to the method of Crocker et al. A difference between AgNOR sizes in peritumor and tumor tissue is noted. The mean NOR numbers in the tumor areas range from 0.871 to 2.677, without overlap between peritumor gliosis and glial tumors. A comparative analysis reveals significant correlations between the mean NOR number per nucleus and histological grading. This technique can play a practical role in the diagnosis and grading of tumors sampled by stereotactic biopsies: a count higher than 0.8 is highly suggestive of malignancy. In addition, the distribution of NORs may be important: intratumoral heterogeneity expresses various degrees of transcriptional activity between different glial tumors of the same grade. This technique provides information about the biological behaviour of glial tumors supplementary to that obtained from growth fraction analysis.

Evaluation Studies as Topic↗

Toxoplasma gondii: immunocytochemistry of four immunodominant antigens with monoclonal antibodies.

Four monoclonal antibodies in which diagnostic usefulness has been observed, concerning congenital, acquired, and reactivated toxoplasmosis, were raised against Toxoplasma gondii tachyzoïtes in order to localize immunodominant antigens. On immunoblots, it appears that McAb IV47, McAB GII9, McAb II38, and McAb IE10 identify families of proteins with estimated molecular weights of 28-30 kDa, 30 kDa, 45-50 kDa, and 66-70 kDa, respectively. By immunogold preembedding techniques one can observe an homogeneous labeling of the outer pellicle of the tachyzoïtes with the McAb GII9 and IV47 and a light labeling with the McAb II38 and IE10. The three-dimensional observation of cell surface antigens is performed by applying a modified metal extraction replica method, i.e., A plasma polymerization method of glow discharge by Tanaka (1979). By immunogold preembedding techniques [with saponin permeabilization (0.1%)], and by immunogold postembedding techniques, a labeling of the rhoptries is observed with McAb GII9 and McAb IV47 but essentially all label is found with McAb II38 and IE10. With McAb GII9 a uniform labeling is observed on the cell surface. By immunoenzymatic techniques (peroxidase) a cell surface labeling is observed with the four McAb. Intracellular Toxoplasma, the outer pellicle, and the vesicles of the network (elaborated by Toxoplasma in parasitophorous vacuole) are also labeled with McAb IE10. These results indicate that McAb GII9 recognizes antigens of the antigen family (P 30) located on the cell surface and in the rhoptries. The antigen recognized by McAb IV47 is essentially located on and beneath the Toxoplasma cell surface membrane, and McAb II38 and IE10 identify preferentially rhoptry proteins.

Animals↗