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Biomedical subjects

Y J Bignon

Publications and source records attributed to Y J Bignon.

At least 19 recordsLinked to original sources
PubMed1992

Neoadjuvant chemotherapy in 126 operable breast cancers.

126 patients with non-inflammatory operable breast cancer, who otherwise would have undergone modified radical mastectomy (MRM), were treated by induction chemotherapy. Before treatment, every patient had a local and general assessment, and pathological or cytological evidence of malignancy. Patients received, every 3 weeks, the same treatment with doxorubicin, vincristine, cyclophosphamide, 5-fluorouracil (AVCF); methotrexate was added in 80 cases (AVCFM). Tumour shrinkage greater than 50% was documented in 105 (83%) of the 126 women. A higher objective response rate was obtained in aneuploid or high S phase tumours, especially in the patients treated with methotrexate. After chemotherapy, 41 patients were then treated by radiotherapy alone after complete or sub-complete response; 64 had a residual tumour that could be treated by conservative surgery and radiotherapy. Only 19 had MRM and radiotherapy. Histopathological complete remission was documented in 1 case; isolated residual tumour cells were found in 5 patients. Thus primary chemotherapy enhanced the possibility of breast conservation in up to 83% of the cases in a series in which most would have been otherwise subjected to a MRM because of tumour size.

Adjuvants, Pharmaceutic↗
PubMed1992

Effect of epidermal growth factor in HLA class I and class II transcription and protein expression in human breast adenocarcinoma cell lines.

The spontaneous expression of HLA class I and class II molecules in two human breast carcinoma cell lines (MCF7, T47D) and their modulation during epidermal growth factor treatment are reported. Transcription was analysed by Northern blot and hybridisation with HLA class II and class I cDNA specific probes. The expression of cell surface determinants was examined by internal protein labelling with 35s-methionine, immunoprecipitation with monoclonal antibodies specific for HLA class I or class II, followed by isolation of the immune complex on protein A-Sepharose; at least a quantification of glycoprotein was performed by chromatofocusing. Glycoprotein quantification showed a significant increase of HLA class I and class II (DR) antigen expression after stimulation by epidermal growth factor (0.02 microgram ml-1) in the two cell lines, when compared with untreated cell controls. However, with epidermal growth factor treatment of MCF7 and T47D cells, low increases in the amounts of HLA class I and class II RNA were obtained. These differences between expressed antigens and correspondent RNA amounts would be explained by the fact that EGF in these two cell lines acts more in post-transcription for HLA class I and class II antigens.

Adenocarcinoma↗
PubMed1992

Hydantoin-induced cutaneous pseudolymphoma with clinical, pathologic, and immunologic aspects of Sézary syndrome.

BACKGROUND: The phenytoin-induced hypersensitivity syndrome is characterized by the development of fever, rash, lymphadenopathy, and hepatitis associated with leukocytosis and eosinophilia. This article describes the unusual occurrence of a pseudo-Sézary syndrome in the days following the introduction of phenytoin treatment. OBSERVATION: A phenytoin-induced erythroderma developed in a 60-year-old woman the histologic, cytologic, and immunologic characteristics of an erythrodermal cutaneous T-cell lymphoma of the Sézary syndrome type with lymph node involvement. The dramatic improvement after withdrawal of drug therapy and the absence of recurrence 5 years after led us to consider it as a hydantoin-induced pseudolymphoma. CONCLUSIONS: Although lymph node pseudolymphomas induced by phenytoin are well known, few cases of hydantoin-induced mycosis fungoides have been reported in the literature. We present herein the first case of a Sézary-like syndrome associated with phenytoin therapy. Such a patient must be monitored regularly because of the risk of a true malignant lymphoma developing even many years later.

Aged↗
PubMed1991

Genotypic analyses of Richter's syndrome.

The authors report the immunogenotype of two cases of Richter's syndrome. The immunoglobulin gene rearrangement pattern obtained on Southern Blot analysis was found in both cases to be the same in leukemic blood cells and in the tissue involved by the lymphoma. The beta chain and gamma chain T-cell receptor gene rearrangement pattern exhibited a germ-line configuration in the peripheral blood cells and in the lymph node in Case 2, whereas in Case 1 the lymph node had a gene rearrangement in the beta chain, as well as in the gamma chain T-cell receptor, and the leukemic cells from bone marrow were found to be in a germ-line configuration for T-cell receptors (beta and gamma chains).

Aged↗
PubMed1991

Detection of Epstein-Barr virus sequences in primary brain lymphoma without immunodeficiency.

We searched for Epstein-Barr virus (EBV) sequences by enzymatic DNA amplification in nine primary brain lymphomas from patients without immunodeficiency. We used seven nonlymphoma brain tumors as negative controls, and the Raji cell line as a positive control. We detected EBV DNA, using ethidium bromide-stained-agarose minigel electrophoresis and dot blot hybridization, in the positive control and in only one brain lymphoma tumor; we did not detect EBV DNA in the other tumors. The EBV-positive patient had a second B-cell monoclonal population in the peripheral blood without detectable EBV DNA, suggesting a direct role for EBV in the development of the brain lymphoma.

Brain Neoplasms↗
PubMed1990

Clonotypic heterogeneity in cutaneous T-cell lymphomas.

The antigen receptor genes studied (immunoglobulin gene for B-cells, and T-cell receptor -beta or -gamma gene for T-cells) represent the most powerful tools for diagnosing the clonality of a lymphoid lineage. We have clonotyped 23 cutaneous T-cell lymphomas and 5 were found to be clonotypically all heterogeneous. Analysis of each patient was performed either from serial skin biopsies taken several months apart or from different tumor samples. In these cases, T-cell lymphoma clonotypic heterogeneity was demonstrated and was especially evident when examining different tumor sites. Moreover, in one case, a biogenotypic population (immunoglobulin and T-cell receptor-rearranged) was found. This unexpected high frequency of T-cell clonal heterogeneity (22%) could be explained either by the evolution of subclones from a single undifferentiated malignant cell or by the independent transformation to cancer of 2 or more lymphocytes, though the latter seems less likely. Clonotypic heterogeneity seems to be as frequent in T-cell lymphomas with cutaneous lesions as in B-cell leukemias.

Gene Rearrangement↗
PubMed1990

[Adjuvant medical treatment].

Adjuvant medical treatments (chemotherapy or endocrine therapy) are now used in the vast majority of women with breast cancer. They delay recurrences and reduce their number, the increase in survival being particularly marked in limited forms. They also reinforce local treatment and increase the possibility of breast conservation. Their indications can be better determined by precise analysis of prognostic factors, notably tumoral cells.

Adjuvants, Pharmaceutic↗
PubMed1990

Detection of Epstein-Barr viral genomes in lymph nodes of Hodgkin's disease patients.

Previous studies using Southern blot analysis or in situ hybridization have shown that approximately 20% of patients with Hodgkin's disease have Epstein-Barr virus (EBV) in involved tissues. We used the more sensitive polymerase chain reaction (PCR) technique to determine if a higher percentage of EBV could be detected. Of the 16 Hodgkin's disease patients studied, the PCR technique detected EBV in eight (50%). No prognostic significance was associated with the presence of EBV in the eight EBV-positive patients, and the presence of EBV was not associated with B cell monoclonality.

Adolescent↗
PubMed1990

Dual genotype in cutaneous T-cell lymphomas and pseudolymphomas.

Genomic DNA digests of skin biopsies from 20 patients with cutaneous T-cell lymphomas and pseudolymphomas were studied by hybridization, using probes for the constant region of the T-cell receptor beta chain and the joining region of the immunoglobin heavy chain gene. Skin biopsies from all 20 patients contained a monoclonal T-cell population. In addition, DNA from 5 patients contained an immunoglobulin gene rearrangement. These results demonstrate that cutaneous T-cell lymphomas are clonal T-cell malignancies that frequently express a dual genotype, which may sometimes reflect the clonotypic heterogeneity of these disorders.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece↗
PubMed1990

Genotypic analyses of Hodgkin's disease.

In spite of the use of molecular biology, the cellular lineage and clonality of Reed-Sternberg cells, the abnormal cells of Hodgkin's disease, remain an enigma. We studied the pattern of rearrangements at immunoglobulin and T-cell receptor loci in 23 patients suffering from Hodgkin's disease. Two out of 23 patients exhibited immunoglobulin gene rearrangements. No rearrangements of the T-cell receptor beta-chain gene were detected in any patient examined. Our results showed no correlation between the presence of rearranged bands and the number of Reed-Sternberg cells.

Antigens, CD↗
PubMed1990

A single Cys706 to Phe substitution in the retinoblastoma protein causes the loss of binding to SV40 T antigen.

Most naturally occurring mutants of the retinoblastoma (RB) protein contain large deletions or truncations. The small cell lung carcinoma cell line H209 contains a normal-sized but unphosphorylated RB protein (Hensel et al., Cancer Res., 50: 3067-3072, 1990), which fails to form a complex with SV40 T antigen, suggesting that the RB gene of H209 may contain a subtle mutation. To define this mutation, the RB complementary DNA and genomic DNA were sequenced, revealing a point mutation in exon 21 that changed a G to a T. This results in an amino acid substitution of a Phe for Cys706. The mutant RB complementary DNA was used as a template for in vitro transcription and translation to synthesize the mutated protein. The resulting protein failed to bind to SV40 T antigen, demonstrating that a single missense mutation of the RB gene led to the complete inactivation of the ability of the RB protein to bind T antigen.

Amino Acid Sequence↗
PubMed1988

Evidence of 3 beta-hydroxysteroid dehydrogenase activity in several murine embryonal carcinoma cell lines.

This report describes, for the first time to our knowledge, a possible steroidogenic activity in established murine embryonal carcinoma cell lines (PCC3, PCC4, F9), revealed by a 3 beta-hydroxysteroid dehydrogenase activity (revelation of NADH2 by staining, and RIA assessment of delta 4-androstenedione). The remarkable analogy between such totipotent cells and embryonal cells may suggest that this activity could be present before histologic organization of the embryonal testis. Nonmalignant embryonal cells such as fibroblasts (3/A/1/D-3) or myoblasts (T984) were also found to possess a 3 beta-hydroxysteroid dehydrogenase activity, thus suggesting that this enzyme is not specific to hormone-secreting cells, but the sign of a more general phenomenon.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Molecular biology diagnosis in oncology.

The applications of molecular biology diagnosis in oncology are presented and discussed. These are: improved nosologic definition; diagnosis of clonality; definition of new prognosis subgroups in some cancers; as an aid in bone marrow transplantation follow-up; diagnosis of the residual disease; early diagnosis of cancer; evaluation of individual cancer risk.

Bone Marrow Transplantation↗