Biomedical subjects

C Rigaud

Publications and source records attributed to C Rigaud.

At least 19 recordsLinked to original sources

PubMed2006

Validation of an internal method for the diagnosis of infections with Chlamydophila abortus and Coxiella burnetii by real-time multiplex PCR.

Chlamydophila abortus and Coxiella burnetii are one of the major pathogens implicated in abortion in cattle. Their characteristic of obligate intracellular bacteria, and of zoonotic agents, makes their culture difficult in diagnostic laboratories, and the traditional tools of diagnosis (detection of sera antibodies by ELISA, Stamp's coloration) encounter specificity, sensitivity and interpretability limits. Individual PCR have recently been developed. Nevertheless, their income/cost is a limiting factor for breeders. As the symptoms are not specific, the request for analysis often concerns the two valences. Consequently, the development and the validation of an internal multiplex PCR appears to be a suitable solution.

Abortion, Veterinary↗

PubMed2005

Comparison of liquid based cytology and histology for the evaluation of HER-2 status using immunostaining and CISH in breast carcinoma.

BACKGROUND: HER-2 amplification is an important prognostic biomarker and treatment determinant in breast carcinoma. AIMS: To correlate immunocytochemical (ICC) expression of HER-2 and gene amplification determined by chromogenic in situ hybridisation (CISH) using liquid based cytology (LBC) with immunohistochemistry (IHC) and CISH using histological samples of the same breast carcinomas. METHODS: Frozen sections and cytobrushings of 103 breast carcinomas were analysed. Four techniques were performed on each tumour: two on LBC samples (ICC, and CISH, both graded as positive, indeterminate, or negative) and two on histological samples (IHC and CISH). Two cell lines (MCF-7, negative; BT 474, positive) were used as controls for cytological analysis. A complementary fluorescence in situ hybridisation technique was carried out in histological samples with low amplification (4-10 dots/nucleus). RESULTS: Interobserver agreement for the four techniques calculated by the kappa coefficient indicated a substantial agreement. Nine cases failed in cytology because of poor cellularity. Among 94 cases, 19 were amplified; 73, 12, and 9 tumours were scored 0 or 1+, 2+, and 3+, respectively by IHC and 75, 13, and 6, respectively, by ICC. CISH found no amplification in 72 tumours. Correlations between the IHC and CISH results in the histological and cytological samples were always significant. CONCLUSIONS: Her-2 status could be determined in LBC samples and correlated well with reference histological methods using in situ hybridisation. ICC was less reliable because of the presence of the cytoplasmic membrane. However, these results should be confirmed by a large multicentre study.

Adult↗

PubMed2003

Calibration of immunohistochemistry for assessment of HER2 in breast cancer: results of the French multicentre GEFPICS study.

AIMS: HER2 protein is over-expressed in 15-30% of breast carcinomas. Immunohistochemistry (IHC) is a common and inexpensive method able to specifically detect HER2 protein. However, lack of standardization of IHC has been considered responsible for discrepancies in HER2 status assessment performed by IHC and fluorescence in-situ hybridization (FISH). This prompted us to perform a multicentric IHC calibration test to achieve a maximum accuracy of HER2-IHC compared with HER2-FISH taken as the reference method. METHODS AND RESULTS: Twelve French laboratories participated in this study, including 119 cases of invasive breast carcinomas for which both fixed and frozen tissues were available. HER2 expression was determined in fixed tissues by individual in-house IHC techniques, using either CB11 (Novocastra, Newcastle, UK) or A0485 (Dako, Glostrup, Denmark) anti-HER2 antibodies. Two cut-off values were used: 10% and 60% of immunostained cells. In 116 of the 119 cases, HER2 gene status could also be determined by FISH on frozen sections, performed in a single laboratory. Results were centralized and compared. When suboptimal concordance between IHC and FISH was observed, IHC was calibrated and a second run was performed. The specificity, sensitivity and accuracy of IHC compared with FISH were noted before and after calibration. Forty-four out of 116 (38%) tumours showed HER2 gene amplification. Accuracy of IHC was complete in the first run for 6/12 laboratories. Calibration, necessary for the six others, relied mainly on the combination of a heat-induced epitope retrieval step with an increase of dilution of the primary antibody. In the second run, HER2 over-expression was found in 46 (40%) and 44 (38%) of the 116 cases, using 10% or 60% of stained cells as cut-offs, respectively. The corresponding accuracy rates were 93% and 95%. CONCLUSIONS: This study showed that a high accuracy of IHC could be obtained for the determination of HER2 status in all laboratories using their in-house IHC technique, provided that a calibration process was performed. Antigen retrieval procedure, high dilutions of anti-HER2 antibody and the use of specific controls were crucial for HER2-IHC calibration. A 95% accuracy rate of IHC, using FISH as gold standard, was obtained by considering immunolabelling HER2-IHC results as a continuous variable, and taking 60% invasive stained cells as the cut-off for HER2 over-expression.

Adenocarcinoma↗

PubMed2003

[HER2 gene amplification assay: is CISH an alternative to FISH?].

The HER2 proto-oncogene encodes a transmembrane protein, which is considered to function as a growth factor receptor. Overexpression of this protein found by immunohistochemistry in about 20% of infiltrating breast carcinomas, has a predictive value of response to treatment by trastuzumab, an anti-HER2 humanized monoclonal antibody. Search for HER2 gene amplification is necessary to adapt the immunohistochemical technique quality and also in the cases of delicate analysis or weak overexpression. It is usually carried out by Fluorescence In Situ Hybridization (FISH). A more recent hybridization technique, named CISH because of its chromogenic revelation is an alternative method, which gives highly correlated results with FISH. We present details of this technique, which may be more familiar for the pathologists than FISH, because reading analysis is similar to that of immunohistochemical staining.

Breast Neoplasms↗

PubMed1998

Remaining indications for total mastectomy in breast carcinoma

Does radical mastectomy for cancer remain needed? Breast conserving treatment may be achieved by surgery, primary chemotherapy followed by radiotherapy and surgery. This article attempts at defining (according to clinical and pathological parameters of the tumor and patient's characteristics), when conservative treatment is not allowed and radical mastectomy must be performed. Mastectomy must be performed first when there are multiple tumors or a tumor too large with respect to the breast volume or diffuse microcalcifications on mammograms.ometimes the stage of pregnancy, a personal history of collagen vascular disease or prior radiotherapy or the willing of the patient lead to perform radical mastectomy.econdary mastectomy is necessary in case of failure of conservative treatment or recurrence after breast conserving treatment.

Journal Article↗

PubMed1998

[Do indications remain for total mastectomy for cancer?].

Does radical mastectomy for cancer remain needed? Breast conserving treatment may be achieved by surgery, primary chemotherapy followed by radiotherapy and surgery. This article attempts at defining (according to clinical and pathological parameters of the tumor and patient's characteristics), when conservative treatment is not allowed and radical mastectomy must be performed. Mastectomy must be performed first when there are multiple tumors or a tumor too large with respect to the breast volume or diffuse microcalcifications on mammograms. Sometimes the stage of pregnancy, a personal history of collagen vascular disease or prior radiotherapy or the willing of the patient lead to perform radical mastectomy. Secondary mastectomy is necessary in case of failure of conservative treatment or recurrence after breast conserving treatment.

Breast Neoplasms↗

PubMed1993

Medullary carcinoma of the breast. A multicenter study of its diagnostic consistency.

Nine pathologists from different institutions reviewed in a double-blind study 16 breast tumors previously indexed as typical medullary carcinoma, atypical medullary carcinoma, or infiltrative ductal carcinoma. A set of 16 slides was circulated two times among the nine pathologists. The diagnoses of typical and atypical medullary carcinomas were based on a definition given by Ridolfi et al. The interobserver and intraobserver agreement was low, with a kappa value of less than .50. The only histological criterion that had more than 50% agreement was the presence or absence of an in situ component in the tumor, assuming that the disagreement of one pathologist is accepted. This study is a snapshot of the problems encountered in the diagnosis of typical medullary carcinoma in a routine context and it shows high levels of variations in diagnostic consistency.

Breast Neoplasms↗

PubMed1992

[Limited lumpectomy combined with peroperative curietherapy for conservative treatment of breast cancer].

Lumpectomy together with axillary clearance and radiotherapy is a good alternative to Patey's operation for treating early cancers of the breast. In any case it has not been definitely worked out how much should be removed. In certain patients not much needs to be removed, in other larger areas of tissue need to be excised. We present our technique for carrying out limited lumpectomy which is carried out at the same time as radiation therapy making it possible to perform a less radical clearance. The results in the first 17 patients we have followed up with a mean of 4.5 years are very encouraging. There was only one local recurrence; this was some distance away from the area of the lumpectomy. The limits for the method are determined by the examination that is carried out on the margins that have been removed and on the availability of a team comprising surgeon, histopathologist and radiotherapist.

Adult↗

PubMed1991

Apparent lack of usefulness of monoclonal antibody Ki-67 in thyroid tumour pathology. Relation to histological typing and classification.

In order to test its potential application to thyroid tumour pathology, the monoclonal antibody Ki-67 was used to demonstrate immunohistochemically proliferating cells in 31 non neoplastic and neoplastic lesions of the thyroid. Twenty benign lesions were negative. Of the 11 malignant tumors, 4 papillary, 2 follicular and 1 medullary carcinomas were also negative; only 3 follicular and 1 medullary carcinomas were positive. Moreover, no correlation was found between Ki-67 immunostaining status and histological typing or pTNM pathological classification in the 11 malignant tumors.

Antibodies, Monoclonal↗

PubMed1991

[Evaluation of the role of MRI at 1.5 T in the staging of the initial extension of cancer of the uterine cervix].

To evaluate the sensibility and specificity of MRI in the initial staging of carcinoma of the uterine cervix, a retrospective study of 41 patients (48 MR scans) was undertaken. The sensitivity of T2-weighted images in the detection and determination of tumor location was 90% and specificity was 100%. On T2-weighted images, the signal intensity of the tumor was high in 64%. Determination of tumor size was correct in 80%. The ability of MRI to demonstrate the extension to the uterine corpus was acceptable with a sensitivity of 63% and a specificity of 100%. The extra-uterine extension was difficult to appreciate especially for parametrial, vaginal and bladder involvement with a sensitivity of 38%, 43 and 67% respectively. Concerning the lymph nodes involvement, the sensitivity was 38%. The results of this study point out the ability of MRI to evaluate the size and location of the tumor. The accuracy of MRI to appreciate the involvement of the parameters, vagina and bladder is disappointing.

Adolescent↗

PubMed1990

Melanin production in black medullary thyroid carcinoma (MTC).

Melanin production by two medullary carcinomas of the thyroid is reported and discussed. In both tumours, melanin and calcitonin could be detected in the same cells.

Adult↗

PubMed1990