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Y Fradet

Publications and source records attributed to Y Fradet.

At least 91 records · Page 5Linked to original sources
PubMed1992

Immunopathologic analysis of human urinary bladder cancer. Characterization of two new antigens associated with low-grade superficial bladder tumors.

The authors have further characterized the normal human tissue distribution and tumor expression of two highly restricted tumor-associated antigens, detected by mouse monoclonal antibodies M344 and 19A211, which are primarily expressed on low-grade superficial urinary bladder tumors. This study was conducted using immunohistochemical staining of frozen and deparaffinized sections of human normal and tumor tissues. The antigens are stable and well preserved on deparaffinized tissue sections. M344 antibody identifies a high-molecular-weight determinant on a cytosolic protein component of over 300,000 Mr. This antigen was not detected on any normal tissue analyzed, including 14 specimens of normal urothelium and 22 cases of cystitis; however, M344 was positive in 74.5% of Ta-T1 tumors and 11% of T3-T4 tumors. 19A211 antibody identifies a sialylated epitope on a cytoplasmic protein complex of 100,000 to 200,000 Mr. This antigen also was expressed preferentially on low-grade superficial bladder tumors (77% Ta-T1) and less frequently on deeply infiltrating tumors (10% T3-4). 19A211 was negative on all normal cells tested, with the exception of umbrella cells, in approximately 25% of the normal urothelium and cystitis specimens studied. Either one or both of these tumor-associated antigens are detected in approximately 80% of low-grade papillary superficial tumors and carcinoma in situ of the urinary bladder. The expression of these antigens on a subset of low-grade bladder tumors, known to progress in only about 10% of cases, suggests that phenotypic differences may reflect biologic potential. Beyond their possible biologic significance, antibodies M344 and 19A211 may provide clinically useful probes for early detection and stratification of urinary bladder tumors.

Antibodies, Monoclonal↗
PubMed1991

DNA slit-scan flow cytometry of bladder irrigation specimens and the importance of recognizing urothelial cells.

DNA slit-scan flow cytometry was used to analyze 150 bladder irrigation specimens from 83 patients. Specimens were categorized into groups based on cystoscopy, histology, and cytopathology. Cells were stained for DNA with propidium iodide using a whole cell protocol. Non-specific fluorescence in the cytoplasm of some urothelial cells together with differential DNA staining of cell types in certain specimens was noted. DNA frequency distributions were analyzed using a semi-automated technique. Data were gated using slit-scan morphological features to remove cellular debris, multiple nuclei, and cells exhibiting nonspecific cytoplasmic fluorescence. Specimens were classified abnormal if they were aneuploid or had a hyperdiploid fraction (HDF) greater than 8%. The sensitivity to abnormality was 89% for grade 3 transitional cell carcinoma (TCC), 70% for grade 2 TCC, and 67% for grade 1 TCC. Specificity was 61%. Specimen data were then reprocessed using slit-scan morphological features to enrich for urothelial cells. The urothelial cells were identified by the ratio of nuclear diameter to cell diameter. This method was found to be in good agreement with immunofluorescent labeling of urothelial cells using the urothelium-selective T16 monoclonal antibody. The sensitivity to abnormality remained 89% for grade 3 TCC and 70% for grade 2 TCC, but fell to 52% for grade 1 TCC. Specificity for the urothelial cell enriched data increased to 77%. Reprocessing of data to enrich for urothelial elements resulted in 16 fewer specimens with an aneuploid DNA distribution and 2 fewer specimens with increased HDF.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneuploidy↗
PubMed1991

Precision of DNA flow cytometry in inter-institutional analyses.

A Bladder Cancer Flow Cytometry Network study has been carried out to further identify and quantify sources of inter- and intra-laboratory variability. Replicate samples containing four mixtures of peripheral blood lymphocytes and aneuploid cell lines were distributed together with reference standards to six laboratories. The samples were stained for DNA using propidium iodide, with each laboratory using its own staining protocol. Two of each of the four sample types and a reference standard were analyzed by each laboratory on 3 separate days to obtain cellular DNA distributions. DNA index (DI) and hyperdiploid fraction (HDF) were calculated for each histogram using an automated technique. The results showed significant inter- and intra-laboratory differences. Results were evaluated by a two-way analysis of variance to estimate components of the overall variation attributable to individual sources. Error variation was found to be the major component of random variation. Specimen means were also compared for each laboratory. No significant differences were noted in mean DI for similar specimens; however, agreement in HDF between similar specimens was lacking in most laboratories. Prediction intervals were computed to estimate the range of values expected for a single specimen based on the analysis of the previous six. Prediction intervals for DI were quite good while those for HDF were troublesome due to wide variation. The results of these studies indicate that intra- and inter-laboratory variability are high enough that results for a single sample may not be sufficiently precise to allow comparison to results obtained in other laboratories.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1991

Comparison of 15 monoclonal antibodies against tumor-associated antigens of transitional cell carcinoma of the human bladder.

Quantitative urinary immunocytology with our monoclonal antibody (mab) 486p 3/12 proved to be valuable for diagnostic use in bladder-cancer patients' urine, especially in the followup of patients with superficial bladder carcinoma. To evaluate the use of other monoclonal antibodies in bladder cancer, we compared 15 mabs directed against bladder-tumor-associated antigens from seven research groups in a broad panel of cellular and tissue specimens (bladder tumor, prostatic adenoma, and kidney stone). Quantitative evaluation was done in cytocentrifuged preparations and tissue specimens. None of the 15 mabs was bladder-tumor-specific. All 15 stained normal urothelium to some extent and six stained granulocytes. Each of the 15 seemed to identify a different cellular antigen, as can be clearly demonstrated by the staining pattern of different regions in the normal kidney. The sensitivity of quantitative urinary immunocytology in bladder-tumor patients can be improved by using a panel, rather than one mab in bladder-tumor patients, but specificity decreases simultaneously. A main reason for the poor specificity of quantitative urinary immunocytology with all 15 mabs is that false-positive results are obtained with all mabs in kidney-stone patients. Our quantitative urinary immunocytology method is a general tool for the diagnostic use of all mabs in bladder-tumor patients. Mabs that have a high sensitivity might be useful in the followup of patients with superficial bladder carcinoma. None of the 15 mabs (because of their poor specificity) seems to be helpful in quantitative urinary immunocytology for screening a population for bladder carcinoma.

Antibodies, Monoclonal↗
PubMed1991

Molecular and immunologic approaches in the management of bladder cancer.

Because of the heterogeneous nature of bladder cancer and the various therapeutic options available, the management of the disease is a constant challenge to clinicians. A variety of new biologic approaches are beginning to unravel some of the pathophysiology underlying the behavior of these tumors and provide means to assess it at the clinical level. Monoclonal antibodies are particularly well suited for more immediate application as diagnostic and prognostic tools and may also have an impact on the treatment of patients with bladder cancer.

Antibodies, Monoclonal↗
PubMed1991

Total androgen ablation: Canadian experience.

A multicenter randomized, double-blind trial comparing total androgen blockade obtained by the use of castration with a pure anti-androgen (nilutamide) with simple castration was begun. One hundred and five patients received the combined treatment and 103 the orchiectomy plus placebo. Several features were used to evaluate the efficacy. Bone pain responded better to combined treatment at 6 months (P = 0.042). The number of favorable responses, as evaluated by the NPCP criteria, was 61% with simple castration and 78% with the combined treatment (P = 0.013). There was no statistically significant difference between the two groups in time to progression (logrank test P = 0.462) or survival (logrank test P = 0.137) despite an increase in median survival of 5.4 months. All other measures showed no difference between the two treatments. With total androgen blockade, 50% of the patients had disease progression at 1 year, and 45% were dead at 2 years. A review of the results of similar reported studies suggests no improvement or very modest improvement with total androgen blockade over testicular androgen ablation alone.

Adult↗
PubMed1990

Monoclonal antibody against a tumor-associated sialoglycoprotein of superficial papillary bladder tumors and cervical condylomas.

A mouse IgG1 monoclonal antibody (MAb), 19A211, defining a tumor-associated cell-surface antigen of superficial papillary bladder tumors, was generated by immunizing with fresh bladder tumor cells mice neonatally injected with normal human urothelial cells. The reactivity of the antibody with cell lines was examined by indirect immunofluorescence staining and was restricted to 3/14 bladder cancer lines and 3/31 cancer cell lines of non-bladder origin, including HeLa cervical cancer. No normal fibroblast, kidney cells, EBV-lymphocytes, erythrocytes or leukocytes expressed the antigen. Reactivity of MAb 19A211 was well preserved on tissue paraffin sections. Immunoperoxidase staining of normal adult or fetal tissues showed no reactivity except for a patchy or uniform staining of umbrella cells in 6/23 adult and 1/4 fetal urothelium samples. Positive and often heterogeneous staining was observed on 24/38 papillary superficial tumors (Ta) and 4/5 carcinoma in situ bladder lesions but on only 4/20 infiltrating tumors. It was also observed on 5/6 cervical condylomas and one bladder condyloma, but none of 6 penile or vulvar condylomas. All other tumors tested were negative. The antigenic determinant is present on a heterogeneous group of proteins with molecular weights ranging from 90 to 200 kDa. It is sensitive to periodate treatment and to neuraminidase but only partially sensitive to proteases. MAb 19A211 is different from other reported MAbs with similar reactivity to superficial bladder tumors and umbrella cells of normal urothelium. When tested in competition assays, several of these MAbs, but not 19A211, were found to react with Lewis X blood group determinant. Our results suggest that 19A211 may be useful for detection and stratification of bladder tumors.

Antibodies, Monoclonal↗
PubMed1990

A controlled trial of castration with and without nilutamide in metastatic prostatic carcinoma.

A randomized double-blind trial in patients with disseminated, previously untreated prostate cancer (Stage D2) was conducted in eight Canadian centers. All 203 patients enrolled in this study underwent bilateral orchiectomy and were randomized to receive either the nonsteroidal anti-androgen nilutamide or a placebo. Patient responses were graded according to the criteria of the National Prostatic Cancer Project (NPCP). Patients treated with nilutamide had a significantly greater number of positive objective responses (partial and complete regression) than did the patients treated with castration alone (46% versus 20%, P = 0.001). Progression-free survival was improved initially in the nilutamide group, but the median time to progression was 12 months for both groups. Despite an increase in the median length of survival from 18.9 to 24.3 months with the nilutamide, the survival time was not significantly longer in the nilutamide group (log = rank test, P = 0.048). Although minor side effects were frequent, adverse effects related to the medication and leading to discontinuation of treatment were observed in 9% of cases. These results suggest some benefit of the combined treatment (orchiectomy + nilutamide) over orchiectomy alone in the treatment of metastatic prostatic carcinoma.

Adult↗
PubMed1990

Clinical cancer progression in urinary bladder tumors evaluated by multiparameter flow cytometry with monoclonal antibodies. Laval University Urology Group.

Multiparameter flow cytometry studies were performed on clinical samples of human bladder tumors to simultaneously analyse DNA content and the expression of surface glycoproteins defined by monoclonal antibodies T16, Om5, T43, and T138. The results of tests performed on 80 samples of bladder irrigations and tumors from 68 patients were correlated with clinical findings at the time of sampling and with disease outcome prospectively (mean follow-up 2 years). Measuring the level of the panurothelial antigen T16 provided more precision in DNA analysis and served as an internal standard to measure the relative expression of the other cell surface antigens studied. The panel of monoclonal antibodies improved the analytical capacity to study the heterogeneity of antigenic phenotypes within individual samples. Aneuploidy frequently correlated with high stage cancers and with a high rate of clinical cancer progression defined as metastasis or death by cancer. However ploidy was not an entirely reliable prognostic indicator since a significant proportion of Ta and T1 nonprogressing tumors were aneuploid, while in 6/20 cases of cancer progression, the samples were near diploid. Contrary to Om5, T43 and T138 antigens were expressed significantly more often on aneuploid samples, although they appear to provide additional information. T138 was positive on 17/18 samples from patients with high stage cancers of which five were near diploid. It was also positive on 4/5 samples from patients with Ta and T1 tumors in whom disease progressed to metastasis and death. Overall, the expression of T138 antigen was a better single indicator of clinical cancer progression than was ploidy. Further stratification was obtained with combined results of DNA and T138 antigen studies. Within the near diploid group, the incidence of bladder cancer death was 0/26 for T138 negative and 5/13 (38%) for T138-positive patients (P less than 0.01). In the aneuploid group incidence of bladder cancer death was 2/10 (20%) for T138-negative and 12/19 (63%) for T138-positive patients (P less than 0.05). These results suggest that simultaneous flow cytometry measurements of DNA and surface antigens may better assess the prognostic behavior of human bladder tumors.

Antibodies, Monoclonal↗
PubMed1990

Growth-regulated surface glycoproteins of human bladder cancer.

Clinical studies of human bladder cancer cells with mouse monoclonal antibodies (mAbs) have revealed two surface glycoproteins (T43 and T138) expressed by aggressive cancers and not by normal cells and a differentiation antigen (T16) expressed by normal and tumor cells of urothelial origin (Y. Fradet et al., Proc. Natl. Acad. Sci. USA, 81: 224-228, 1984; Y. Fradet et al. Cancer Res., 46: 5183-5188, 1986). To investigate further the possible association of these antigenic phenotypes with growth advantage of tumor cells, their expression, according to phases of the cell cycle and growth states (exponential and plateau phase) was studied in the human bladder carcinoma cell line T24. Expression of the p21 ras oncogene product, the Thomsen-Friedenreich antigen and the HLA class I antigen were also studied with mAbs. Multiparameter flow cytometry was used to determine antigen expression and DNA content of cells stained with mAbs and propidium iodide. Two antigens, T16 and T43, showed marked variations of their expression according to the growth status of the cells, although with an inverse profile. T16 was expressed on resting cells up to 12.5 times more than on exponentially growing cells. Conversely, T43 expression increased by a factor of 4.5 on actively proliferating cells. However, there was no preferential expression of either antigen in any one phase of the cell cycle. None of the other antigens studied, including the p21 protein, showed any density variation with either cell cycle or growth states. The results of these studies suggest that T43 may be associated with a growth advantage of tumor cells and that T16 has the characteristics of a differentiation antigen whose expression is induced on resting cells. These findings may have implications for the potential clinical use of these mAbs.

Animals↗
PubMed1988

Renal prostaglandins in postobstructive diuresis. Comparative study of unilateral and bilateral obstruction in conscious dogs.

An experimental model in conscious dogs was developed to investigate the role of prostaglandins (PG) in the obstructed kidney. Renal veins were separately catheterized. Urine flow was shunted to the skin by surgically implanted polyurethane loop ureterostomy so as to allow atraumatic manipulation with maintained continuous flow to the bladder between experiments. One week or more after surgery, renal function parameters as well as renal vein and urinary PGE2 and PGF2 alpha, and renal vein renin were studied during and after unilateral (UUO) and bilateral (BUO) ureteral obstruction. The release of ureteral obstruction produced a constant and marked elevation in urinary PGE2 and PGF2 alpha, two times higher after BUO than after UUO. A close correlation exists between PGE2 and sodium excretion in UUO and BUO. Increasing polyuria was observed only after chronic BUO. In BUO, renal vein renin concentration was augmented after 2 hours but was suppressed after 24 hours of BUO. Renal vein PG concentration was also elevated after chronic UUO and BUO but was in the normal range immediately prior to release of obstruction. The data obtained with the current experimental dog model indicate that the release of ureteral obstruction induces a striking increase in renal PGE2 and PGF2 alpha production which may mediate at least partly the phenomenon of postobstructive diuresis.

Animals↗
PubMed1988

Total androgen blockade for metastatic cancer of the prostate.

This randomized, double-blind study comparing orchiectomy plus placebo to orchiectomy plus a nonsteroid antiandrogen (Anandron) shows that total androgen blockade for metastatic cancer of the prostate provides a significantly better early objective response when compared to castration alone. This response, however, is less apparent at 18 months. The study also suggests a longer survival for the patients with total androgen blockade.

Androgen Antagonists↗
PubMed1987

Polymorphic expression of a human superficial bladder tumor antigen defined by mouse monoclonal antibodies.

Three mouse monoclonal antibodies (mAbs), which define a highly restricted antigen, were obtained by simultaneous immunizations with superficial papillary bladder tumor cells and mouse polyclonal serum against normal urothelium. The antigen was detected by the avidin/biotin/peroxidase method in 30/44 superficial bladder tumors (68%) but in only 4/27 infiltrating urothelial cancers (with much less intensity). No normal adult or fetal tissues tested expressed the antigen, including normal urothelium from 40 individuals, 13 of whom had a bladder tumor positive for the antigen. Only 1 of 45 nonbladder tumors showed some reactivity with one of the three mAbs. Serological tests on a large panel of human cancer cell lines and normal cultured cells were negative. The antigen is highly stable and well preserved on paraffin-embedded tissues. Electrophoretic transfer blot experiments with fresh tumor extracts showed that all three mAbs react with a determinant on a component of 300,000 Mr (pI 9.5) and 62,000 Mr (pI 6.5). The antigen shows polymorphic expression at the cellular level on tissue sections and also at a molecular level on immunoblots where the two bands are differentially detected on extracts of a series of tumors but are not visualized on normal urothelium extracts. The characteristics of this antigenic system suggest that it may provide some insights about the biology of bladder cancer. Specific detection of the antigen on 70% of superficial bladder tumors with normal cytology may be useful for their diagnosis and follow-up.

Animals↗
PubMed1986

Cell surface antigens of human bladder tumors: definition of tumor subsets by monoclonal antibodies and correlation with growth characteristics.

Normal human urothelium and tumors of urothelial origin were analyzed with a panel of seven mouse monoclonal antibodies that identify surface antigens of cultured bladder cancer cell lines. Three categories of antigens were defined on the basis of differential expression on normal urothelium versus bladder tumors. Om5 (a category 1 antigen) is a highly restricted, differentiation antigen detected in the normal urothelium of 50-60% individuals. No other normal cell type in Om5- or Om5+ individuals expresses Om5. The incidence of Om5 expression in superficial bladder tumors is significantly higher (88%) than in normal urothelium, whereas its expression in invasive or metastatic tumors is far lower (20%), suggesting Om5 gain/loss in bladder tumors. Paired biopsies of normal urothelium and bladder tumors from the same individuals have shown Om5 induction in the superficial bladder tumors of Om5- individuals and Om5 loss in invasive bladder cancers of Om5+ individuals. Category 2 antigens (T43, T138, T23) are not expressed by normal urothelium or most superficial bladder tumors but are detected on a high proportion of invasive or metastatic bladder tumors, indicating that category 2 antigens are associated with late stages of tumor progression. Category 3 antigens (T16, T87, J143) provide lineage markers for normal or neoplastic cells of urothelial origin, being found on normal urothelium and virtually all bladder tumors. Thus, differential expression of category 1 and 2 antigens divide bladder tumors into distinct subsets, and these subsets correlate with pathological and clinical features of the disease.

Antibodies, Monoclonal↗
PubMed1985

Effect of intravesical Bacillus Calmette-Guérin on detection of a urothelial differentiation antigen in exfoliated cells of carcinoma in situ of the human urinary bladder.

Flow cytometry was used to detect and quantify expression of a urothelial differentiation antigen (Om5) and nuclear DNA in exfoliated epithelial cells of the urinary bladder from 15 patients with nonpapillary carcinoma in situ during and after intravesical therapy with Bacillus Calmette-Guérin (BCG). Before BCG treatment exfoliated cells reacting with the mouse monoclonal antibody Om5 were found in 13 cases. Following treatment Om5 positive cells were still present in 9 cases but 4 patients who had had Om5 positive cells prior to BCG therapy no longer had detectable antigen-positive cells after therapy. Thus intravesical BCG therapy can alter detection of a urothelial differentiation antigen in exfoliated bladder epithelial cells. It is not certain whether this antigen or other differentiation antigens measured by flow cytometry will advance our present techniques for assessing effects of therapy on carcinoma in situ and other bladder tumors. However, five of nine patients showing persistence of Om5 positive cells after therapy were found to have recurrent tumor by biopsy and two others had positive cytology (median follow-up, 13 months). None of the four without detectable antigen-positive cells after therapy had clinical evidence of tumor by cystoscopy, biopsy, or cytology (median follow-up, 12 months). It now appears feasible and desirable to initiate clinical investigations of this and other differentiation antigens in combination with DNA by flow cytometry of bladder irrigation specimens.

Antigens, Neoplasm↗