Biomedical subjects

C Andrieu

Publications and source records attributed to C Andrieu.

15 recordsLinked to original sources

PubMed2003

Delivery of antisense oligonucleotide to the cornea by iontophoresis.

We wished to evaluate the potential of iontophoresis to promote the delivery of antisense oligonucleotides (ODN) directed at the vascular endothelial growth factor (VEGF)-R2 receptor (KDR/Flk) to the cornea of the rat eye. Fluorescence (CY5)-labeled ODNs in phosphate-buffered saline (PBS) (20 microM) were locally administered to rat eyes, and their fate within the anterior segment was studied. Thirty-four male, 5-week-old Wistar rats were used for all experiments. The rats were divided in four groups. In group I (12 rats, 12 eyes), the ODNs (20 microM) were delivered by iontophoresis (300 microA for 5 minutes) using a specially designed corneal applicator. In group II (12 rats, 12 eyes), the ODNs (20 microM) were delivered using the same applicator, but no electrical current was applied. In group III (6 rats, 6 eyes), a corneal neovascular reaction was induced prior to the application of ODNs (20 microM), and iontophoresis electrical current was delivered as for group I rats. Group IV (4 rats, 4 eyes) received ODN (60 microM) iontophoresis application (300 microA for 5 minutes) and were used for ODN integrity studies. The animals were killed 5 minutes, 90 minutes, and 24 hours after a single ODN application and studied. Topically applied ODNs using the same iontophoresis applicator but without current do not penetrate the cornea and remain confined to the superficial epithelial layer. ODNs delivered with transcorneoscleral iontophoresis penetrate into all corneal layers and are also detected in the iris. In corneas with neovascularization, ODNs were particularly localized within the vascular endothelial cells of the stroma. ODNs extracted from eye tissues 24 hours after iontophoresis remained unaltered. The iontophoresis current did not cause any detectable ocular damage under these conditions. Iontophoresis promotes the delivery of ODNs to the anterior segment of the eye, including all corneal layers. Iontophoresis of ODNs directed at VEGF-R2 may be used for the design of specific antiangiogenic strategy in diseases of the cornea.

Animals↗

PubMed2001

ERBB2 status and benefit from adjuvant tamoxifen in ERalpha-positive postmenopausal breast carcinoma.

We examined the relation between ERBB2 gene expression (as determined by a real-time quantitative RT-PCR assay) and the response to adjuvant tamoxifen therapy in a well-defined cohort of 125 ERalpha-positive postmenopausal patients with breast cancer. Although ERBB2 overexpression was associated with shorter relapse-free survival in univariate analysis (P=0.00029), ERBB2 did not persist as an independent prognostic factor in multivariate analysis. Nevertheless, when we analyzed the ERBB2 mRNA level as a continuous variable, the higher the ERBB2RNA level, the poorer the outcome (P=0.00036). The results point to the need for a quantitative ERBB2 expression assay for use in future studies of ERBB2-based clinical management of breast cancer.

Aged↗

PubMed2001

The CGA gene as new predictor of the response to endocrine therapy in ER alpha-positive postmenopausal breast cancer patients.

We recently identified CGA (coding for the alpha subunit of glycoprotein hormones) as a new estrogen receptor alpha (ER alpha)-responsive gene in human breast tumors. Here, we assessed the relationship between CGA status (as determined by real-time quantitative RT-PCR) and the response to tamoxifen therapy in a well-defined cohort of 125 ER alpha-positive postmenopausal breast cancer patients treated with primary surgery followed by adjuvant tamoxifen alone. CGA overexpression, observed in 37.6% of patients, was associated with good relapse-free survival (P=0.037; univariate analysis). CGA status, combined with ERBB2 status (a marker of poor outcome), was an independent predictor of the response to tamoxifen (P=0.020; multivariate analysis). CGA status, especially when combined with ERBB2 status, may thus provide useful predictive information on tamoxifen responsiveness in breast cancer.

Aged↗

PubMed2001

Robust full Bayesian learning for radial basis networks.

We propose a hierarchical full Bayesian model for radial basis networks. This model treats the model dimension (number of neurons), model parameters, regularization parameters, and noise parameters as unknown random variables. We develop a reversible-jump Markov chain Monte Carlo (MCMC) method to perform the Bayesian computation. We find that the results obtained using this method are not only better than the ones reported previously, but also appear to be robust with respect to the prior specification. In addition, we propose a novel and computationally efficient reversible-jump MCMC simulated annealing algorithm to optimize neural networks. This algorithm enables us to maximize the joint posterior distribution of the network parameters and the number of basis function. It performs a global search in the joint space of the parameters and number of parameters, thereby surmounting the problem of local minima to a large extent. We show that by calibrating the full hierarchical Bayesian prior, we can obtain the classical Akaike information criterion, Bayesian information criterion, and minimum description length model selection criteria within a penalized likelihood framework. Finally, we present a geometric convergence theorem for the algorithm with homogeneous transition kernel and a convergence theorem for the reversible-jump MCMC simulated annealing method.

Journal Article↗

PubMed1996

Influence of the extraction procedure on plasminogen activator inhibitor-2 (PAI-2) and urokinase receptor (uPAR) assays in breast cancer tissues.

The levels of uPA, its inhibitors PAI-1 and PAI-2, and the uPA receptor (uPAR) have prognostic value in breast cancer. However, different extraction methods and assays kits are used in different laboratories and may directly influence the levels observed. To define a buffer suitable for both PAI-2 and uPAR extraction from breast cancer tissue compatible with hormone receptors and other cytosolic prognosticator assays, we compared PAI-2 and uPAR values obtained by immunoenzymatic assays (American Diagnostica, Greenwhich, USA) in several extraction conditions: 1) cytosol obtained with the standard hormone receptor buffer; 2) solubilized pellets obtained by Triton X100 extraction of the pelleted membranes obtained with standard hormone receptor buffer; 3) cytosol obtained by direct extraction in the buffer (containing Triton X100) recommended by the manufacturer, after 2 hours or 12 hours of incubation. Cytosol extracts prepared using the standard procedure recommended for hormone receptors gave the highest PAI-2 values. The highest uPAR values were obtained in the subsequent detergent extraction of the pelleted membranes. PAI-2 levels obtained with the kit manufacturer's method after 12 hours of incubation were lower than those obtained after 2 hours of incubation, whereas uPAR levels were similar. We conclude that the most suitable extraction protocol employs standard hormone receptor extraction buffer to obtain a supernatant cytosol fraction for PAI-2 assay, and subsequent detergent extraction of the pelleted membranes to obtain an extract suitable for uPAR.

Breast Neoplasms↗

PubMed1994

Prognostic value of a solubilized fraction of EGF receptors in primary breast cancer using an immunoenzymatic assay--a retrospective study.

In a retrospective study of 319 primary breast cancers, we show that an immunoenzymatic assay of a solubilized fraction of EGF receptors indicates a prognostic value for EGFR which is in contradiction with some (but not all) other studies. It appears that different methodological approaches of measuring EGFR are not equivalent in terms of prognostic power. We emphasize the need for rigorous multicentric standardization and quality control of assays, followed by multistep validation of parameters oriented towards clinical use.

Aged↗

PubMed1994

pS2 and response to adjuvant hormone therapy in primary breast cancer.

We reviewed 319 primary breast tumours for cytosolic pS2 content, with a median follow-up of 6 years. pS2 status correlated positively with oestradiol and progesterone receptors and negatively with Scarff, Bloom and Richardson grade. pS2 positivity was associated with longer overall survival, particularly in patients who received hormone therapy, in whom pS2 status was also predictive of the response to therapy.

Adult↗

PubMed1994

Computer assisted image analysis of bladder tumour nuclei for morphonuclear and ploidy assessment.

Morphonuclear analysis using a quantitative image analysis system has been demonstrated to be a potentially useful technique in the prognostic evaluation of bladder carcinoma. The integrated optical density parameter permits DNA content evaluation in addition to 15 other morphonuclear parameters. We assessed the reliability of morphonuclear analysis by image analysis and flow cytometry for 46 bladder carcinomas and 14 normal bladder specimens. Frozen sample material was obtained from endoscopic resection, radical cystectomy and from cadaveric donors. The grade and staging of the tumours according to the World Health Organization was as follows: 8 G1, 18 G2, 20 G3 and 28 T1, 7 T2, 7 T3, 4 T4. Quantitative image analysis was made on imprint smears stained by the Feulgen method. Simultaneously cell suspensions were obtained by mechanical dissociation and stained with propidium iodide for Flow cytometry analysis. There was a good agreement between quantitative image analysis and flow cytometry for DNA content measurement indicating that image analysis is a reliable method for the quantitation of DNA content (P = 0.001). Moreover we found a good correlation between five of the morphonuclear parameters: surface (P < 0.001), chromatin clumps distribution (P < 0.001), frequency of small (P < 0.001) to large chromatin clumps (P < 0.001) and the grade of bladder tumours. These results indicate that morphonuclear analysis may be a valuable method of quantitating DNA and morphonuclear parameters in a single analysis to provide information which may have some prognostic significance for patients with bladder carcinoma.

Cell Nucleus↗

PubMed1992

Multiparametric prognostic evaluation of biological factors in primary breast cancer.

BACKGROUND: An array of biological features related to tumor cell differentiation status, growth rate, and invasive potential have been identified as potential prognostic factors in breast cancer. We were interested in determining their relative importance in predicting patient survival. PURPOSE: We evaluated the relative weight of the following four biological factors in predicting survival of patients with breast cancer: tumor cell DNA content (determined by flow cytometry), tumor cell proliferation rate (determined by thymidine kinase activity), expression levels of cathepsin D and urokinase plasminogen activator, and several "classical" clinical and histological factors. METHODS: Selected from a prospectively updated database, the study population consisted of 319 primary breast cancer patients who received treatment and follow-up care (median, 6 years) in the Centre René Huguenin. To determine the profile of biological factors for each patient, we used frozen tumor specimens and (except for the flow cytometric DNA content assay) commercially available assay kits. We determined by Cox multivariate analysis the relationships of the biological factors to each other, to classical prognostic factors, and to disease-free and metastasis-free survival. RESULTS: In the overall population, disease-free survival was best predicted by node status (P = .004), clinical tumor size (P = .02), and cathepsin D expression (P = .01), whereas metastasis-free survival was best predicted by node status (P = .0004), clinical tumor size (P = .009), and urokinase plasminogen activator expression (P = .04). In node-negative patients, thymidine kinase activity was the only factor selected for disease-free (P = .04) and metastasis-free (P = .05) survival. In node-positive patients, the number of positive axillary lymph nodes was the only factor selected for disease-free (P = .0008) and metastasis-free (P = .00017) survival. CONCLUSIONS: Our retrospective analysis has identified protease expression and tumor cell proliferation rate as important biological prognostic factors in breast cancer. Prospective clinical trials should be undertaken to confirm these results.

Adult↗

PubMed1992

Enzyme-linked immunosorbent assay of pS2 in breast cancers, benign tumors, and normal breast tissues. Correlation with prognosis and adjuvant hormone therapy.

An enzyme-linked immunosorbent assay using monoclonal and polyclonal antibodies against recombinant pS2 was devised. It was used to measure pS2 concentration in the cytosol of 339 breast cancer, 15 fibroadenomas, 16 cases of benign breast disease, and 6 normal breast tissues. The mean value of pS2 concentration was higher in cancer, but the protein could be detected readily in benign tumors and even in normal breast. The concentration of pS2 was significantly lower in postmenopausal women and tumors of differentiation Grade 3. The pS2 concentration was correlated strongly with the presence of estrogen receptors (ER) and progesterone receptors (PR). No correlation was observed with the size, histologic type of the tumor, and lymph node status. The prognostic value of pS2 appeared relatively limited. It was clear cut only for a relatively small group of patients (approximately 15%), who had low concentrations of pS2 (less than or equal to 0.32 ng/mg of protein). These patients had a shorter disease-free interval and overall survival time. The most striking correlation was observed with the outcome of adjuvant hormone therapy. pS2 concentration was shown to be the most potent prognostic factor, preceding even ER.

Adult↗

PubMed1992

Sequential cytopunctures during preoperative chemotherapy for primary breast carcinoma. II. DNA flow cytometry changes during chemotherapy, tumor regression, and short-term follow-up.

Between May 1986 and May 1987, 35 primary noninflammatory breast carcinomas (T3N0-N1M0) were studied by means of DNA flow cytometry (FCM-DNA) before and after each of three courses of preoperative chemotherapy (doxorubicin, vincristine, cyclophosphamide, methotrexate, and 5-fluorouracil) to assess initial nuclear DNA content, initial S-phase fraction (SPF), and the impact of chemotherapy on these parameters. Correlations were sought with objective regression and short-term follow-up. Four sequential cytopunctures were performed for cytologic examination and FCM-DNA analyses. Ten tumors were diploid and 25 aneuploid. No significant changes in FCM-DNA parameters during chemotherapy were observed in diploid tumors, and no regression was seen in nine of the ten cases. Among the 25 aneuploid tumors, 10 showed changes in DNA content and/or kinetic parameters. A significant correlation was observed between objective regression and initial FCM-DNA content (P = 0.008), initial SPF (P = 0.004), and changes in FCM-DNA patterns observed during chemotherapy (P = 0.00005). During the follow-up period (range, 27 to 41 months), 13 patients had relapses. Patients with aneuploid tumors were more likely to have relapses (n = 11) than patients with diploid tumors (n = 2), and patients with high SPF were more likely to have relapses than patients with low SPF, but the differences were not significant. Similarly, changes in FCM-DNA parameters were observed more often in patients who had relapses, but, again, the difference was not significant. In 5 of the 13 patients who had relapses, FCM-DNA analyses were performed on cytopunctures of the recurrences: patterns were identical to those observed before treatment even when the primary tumor regressed or showed changes in FCM-DNA parameters during chemotherapy.

Adult↗

PubMed1990

Epidermal growth factor receptors and prognosis in primary breast cancer.

A retrospective study was performed on 109 human breast tumors stored in liquid nitrogen in order to assess the prognostic value of epidermal growth factor receptor (EGF-R) (median patient follow-up 5 years). A significant inverse relationship was observed between EGF-R and both estrogen (ER) and progesterone receptors (PR). Univariate analysis showed a trend towards a shorter metastasis-free survival both in the overall population and in node-negative patients with EGF-R positive tumors. Multivariate analysis of the overall population showed that lymph-node involvement and PR status were the only significant variables in predicting metastasis-free survival. However, in patients receiving no adjuvant treatment (hormone therapy or chemotherapy). EGF was the only significant variable in the multivariate Cox analysis. No c-erbB-1 amplification was detected in these tumors.

Adult↗

PubMed1989

Cathepsin D: an independent prognostic factor for metastasis of breast cancer.

122 patients with primary breast cancer were followed-up for a median of 4.6 years after surgery. The concentration of cathepsin D in tumour cytosol was strongly related to both metastasis-free survival and disease-free survival and was independent of nine conventional prognostic indices. Cathepsin D assay may prove particularly useful in identifying women who, though without lymph node involvement at presentation, are at high risk of metastatic disease.

Adult↗

PubMed1989

Cytokeratin analysis of breast and leukemia tumor cell lines by flow cytometry.

Using four human tumor cell lines, MCF-7 and T47-D from breast tumors, MOLT-4 and K-562 from leukemia, flow cytometric DNA analysis of pure and mixed cell population was performed using monoclonal antibodies to cytokeratin to distinguish cytokeratin-containing carcinoma cells from leukemia cells which do not contain cytokeratins. Surprisingly, on pure or mixed K-562 cells, we found positive labeling with KL1, CK8, and CK18 antibodies (results confirmed by immunocytology). This preliminary study has allowed a DNA analysis on epithelial cells of human breast tumors.

Adenocarcinoma↗

PubMedDate not supplied

CCND1 mRNA overexpression is highly related to estrogen receptor positivity but not to proliferative markers in primary breast cancer.

To elucidate the role of CCND1 alterations in sporadic breast cancer we investigated the possible link between CCND1 mRNA levels versus estrogen-receptor (ER) status and a proliferation marker, S-phase fraction (SPF), measured by flow cytometry. CCND1 expression was quantified by means of real-time quantitative RT-PCR in a well-characterized series of 33 primary breast cancer patients. Eighteen tumors (54.5%) showed CCND1 overexpression ranging from 3.3 to 29.5 times the level observed in normal breast tissue. Seventeen (94.4%) of the 18 cases with CCND1 overexpression were ER-positive compared to seven (46.7%) of the 15 cases with normal CCND1 expression (p=0.0074). CCND1 overexpression was independent of SPF and DNA-ploidy status. These data suggest that the CCND1 gene does not act as an oncogene responsible for more rapid cell proliferation in breast cancer, but could be involved in the regulation of hormone sensitivity associated with ER.

Adult↗