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Biomedical subjects

J C Laurent

Publications and source records attributed to J C Laurent.

At least 19 recordsLinked to original sources
PubMed1992

Rapid isolation of human endothelial cells from whole blood using S-Endo1 monoclonal antibody coupled to immuno-magnetic beads: demonstration of endothelial injury after angioplasty.

The presence in whole blood of circulating endothelial cells (EC) has been a subject of debate for many years. It could represent a good marker of vessel injury. We demonstrate here that human endothelial cells can be directly isolated and identified in circulating blood by means of an endothelial cell specific monoclonal antibody, S-Endo1, coupled to micromagnetic beads. The specificity and efficacy of the assay were established using normal blood samples with cultured EC added. Specific rosettes formed between EC and beads could subsequently be isolated with a magnet. The rosetted cells were recovered with a yield greater than 80%. Their endothelial origin was confirmed by the positive labelling of von Willebrand factor and thrombomodulin, as well as the presence of Weibel-Palade bodies. We applied this method to demonstrate significantly increased levels of EC in venous and arterial human blood samples in patients undergoing heart catheterization. This new whole blood immuno-separation method may be useful in determining endothelial cell injury in vascular disorders.

Antibodies, Monoclonal↗
PubMed1992

[Stromal luteoma of the ovary. Differential diagnosis of steroid cell tumors].

An observation of a stromal luteoma of the ovary is reported. It is a rare tumor (only about thirty cases of it have been published yet), occurring mostly in post menopausal women. Endocrine symptoms and sometimes virilizing signs may be observed. Abnormal vaginal bleeding is the most frequent clinical manifestation. This macroscopically observed tumor is surrounded by ovarian stroma and entirely composed of luteinized cells devoid of crystals of Reinke. Hyperthecosis of ovarian stroma is often observed. Its evolution is always benign. The authors recalled the place of stromal luteoma of the ovary among steroid (lipid) cell tumors and the elements of a differential diagnosis. These tumor might derive from ovarian stromal cells.

Adrenal Rest Tumor↗
PubMed1992

[Mass screening for breast cancer in Herault county. First results in women between 40 and 70 years old].

A large scale mammography breast cancer screening has begun in Herault county on the first of july 1990. The aim of the project was to determine the impact of two-view mammography upon the size of the tumor and later upon mortality from breast cancer. The women aged 40-70 at entry were invited by mail to the first round of mobile breast screening. Between the start and the 8th of march 1991, 5098 (64%) attended the first round. The cancer detection rate was 5.9/1000, the positive detection rate was 7.75%, the benign malignant surgical biopsy ratio was 1:0.7 and the percentage of surgical biopsies positives for malignancy was 42.6%. Two months after this study, the screening specificity was 96.7% and the sensibility was 92.7%. The rate of tumor size less or equal to 1 cm was 72% (for 30 malignancies) and the rate of mastectomies was 43.3%. These friendly results were compared to those of others breast cancers screenings.

Adult↗
PubMed1991

Cytofluorometric detection of human endothelial cells in whole blood using S-Endo 1 monoclonal antibody.

It has long been debated whether endothelial cells are present at very low frequency in peripheral blood. Elevated concentrations of such circulating cells may represent a good marker of vascular injury. We have therefore designed an immunocytometric assay for the detection of rare endothelial cells in whole blood. This assay is based on a new monoclonal antibody (MAb) S-Endo 1, made against human umbilical vein endothelial cells (HUVEC) and specific for endothelial cells of various origins without detectable reactivity with blood cells. First, the sensitivity of the assay was established by using normal blood samples with admixed HUVEC as an in vitro model. A good correlation was obtained between added and counted endothelial cells; the recovery was greater than 90% and the minimum detectable concentration of HUVEC was about 0.2 cells/microliters whole blood. Using this rapid counting technique, no detectable levels of endothelial cells were found in the blood of normal individuals (CE less than or equal to 0.1 cells/microliters) while elevated concentrations (up to 8 cells/microliters) were detected in a human model of vascular injury corresponding to a traumatic venepuncture. Thus, this new whole blood immunocytometric assay using S-Endo 1 MAb may be useful in determining the levels of circulating endothelial cells in vascular disorders.

Animals↗
PubMed1991

[Breast cancer: can axillary dissection be restricted to Berg stages 1 and 2? Study of 895 cases].

895 axillary clearances were carried out in 3 years between 1986 and 1988 on 878 patients with primary breast cancer. Two procedures were used: either direct total axillary clearance (in stages 1, 2 and 3 of Berg) or inferior axillary clearance (stages 1 and 2 of Berg). This was carried out in association with frozen section diagnosis of the lymph node followed by clearance in Berg stage 3 if the diagnosis on frozen section was positive. The authors found a higher frequency of late complications, particularly of arm lymphoedema in patients who had complete axillary clearance than in patients who only had an inferior axillary clearance. The survival rate actuarilly calculated was not significantly different in the two groups of patients. The carrying out of total axillary clearance was "beneficial" for only 3 patients who had negative inferior axillary clearance and positive sub-clavicular clearance. Finally the frozen section diagnosis of the state of the axillary nodes shown to be correct (specificity -99% and sensitivity -76%) but it was difficult to carry out routinely.

Adult↗
PubMed1990

A useful monoclonal antibody (BL2-10D1) to identify tumor cells in urine cytology.

The monoclonal antibody (MoAb) BL2-10D1 directed against a tumor-associated antigen of human bladder cancer was used to identify tumor cells obtained by bladder washing or voided urine. The reactivity of BL2-10D1 MoAb was detected by an immunoperoxidase method and evaluated in ten healthy donors and in a series of 65 patients. The 65 patients studied were divided into three groups: ten with nontumor bladder disease (group A); 36 with bladder carcinoma (group B); and 19 with a history of bladder neoplasia but no visible tumor at the time of cytologic sampling (group C). The results were compared with the standard cytologic diagnosis on Papanicolaou-stained preparations. Conventional cytologic study showed a high false-negative rate in low-grade tumors (transitional cell carcinomas [TCC] Grades 1 and 2, 1/4 and 4/17, respectively). All urine from patients with a histologically proved TCC Grade 1 were stained with BL2-10D1 MoAb. Cytologic findings from patients with TCC Grade 2 (17 cases) contained positive cells in 14 cases and failed to react in three cases. Furthermore, whereas urine from patients with TCC Grade 2 or 3 was not always stained with BL2-10D1 MoAb, all patients with dysplastic lesions (three cases) or carcinoma in situ (5 cases) showed a positive reactivity. Such results suggest that BL2-10D1 MoAb may be considered as a valuable adjunct to the classical methods of early detection and follow-up of bladder cancer. However, a larger scale study is needed for MoAb BL2-10D1 to be proposed as an aid to improve the diagnostic sensitivity of urine cytologic investigation in the follow-up of patients treated for recurring bladder cancer, and for the screening of workers exposed to potent bladder carcinogens.

Antibodies, Monoclonal↗
PubMed1990

Pre-clinical evaluation of anti-lacto-N-fucopentaose III (CD15) monoclonal antibodies for ex vivo bone marrow purging in acute myeloid leukemia.

In order to eliminate residual leukemic cells from the marrow of patients with acute myeloid leukemia (AML) prior to autologous bone marrow transplantation, the optimal conditions of utilization of three CD15 murine monoclonal antibodies (MoAb) were investigated. The VIM-D5 MoAb was used with rabbit complement (C'), whereas the 8.27 and SMY15A MoAbs were used in the presence of human C'. These antibodies were also tested after fixation on magnetic beads. In a culture assay in semi-solid medium with a mixture of normal marrow and 1% HL60 cells, a lysis of clonogenic cells greater than 99% was achieved with the three antibodies and two rounds of complement, or with antibody-coated magnetic beads. Cultures of leukemic clonogenic cells (CFU-L) were performed in 47 cases. An inhibition equal to or greater than 90% was achieved in seven cases with VIM-D5, 16 cases with 8.27 and 11 cases with SMY15A and C'. The correlation with cytotoxicity of fresh cells was low. Twenty cases were purged with antibody-coated beads. An inhibition equal to or greater than 90% was observed in 10 cases with VIM-D5, 11 cases with 8.27 and 12 cases with SMY15A. The mean recovery of normal CFU-GM was higher than 70% and that of BFU-E higher than 95% with any method of treatment. It is concluded that efficient marrow purging of clonogenic AML cells can be achieved in some cases without toxicity for normal progenitors. The addition of other MoAbs seems necessary to obtain a significant purge in a majority of cases.

Antibodies, Monoclonal↗
PubMed1990

[Lobular carcinoma in situ of the breast].

The diagnosis of the lobular carcinoma in situ (LCIS), whose frequency is estimated to range from 0.8 to 3.8 p. cent of breast cancers on the whole, is exclusively anatomopathological since it does not have any specific clinical and/or radiological characteristics. After describing the two main differential diagnoses, the various possible treatments are studied, bearing in mind that the therapeutic strategy must take into account the three characteristics which are typical of LCIS: multicentricity, bilaterality and the possible occurrence of an invasive cancer.

Breast Neoplasms↗
PubMed1990

[Evaluation of a modified immunomagnetic procedure for the purging of neuroblastoma cells from bone marrow].

The immunomagnetic depletion method for removing tumor cells from bone marrow, previously refined using a Burkitt lymphoma model, was tested with neuroblastoma cells. The efficiency of depletion was quantified by immunofluorescence with a detection limit of 3.3 log of cell depletion corresponding to the elimination of 99.84% of an initial tumor cell content of 10%. A panel of five monoclonal antibodies (UJ13A; UJ127.11; UJ181.4; alpha-Thy1; H11) purged 2.8 log of SKNBE and LAN-1 cells, while two of these antibodies as single agents allowed only for a 1.7 log (UJ13A) and a 1.7 to 2.0 log (alpha-Thy1) depletion. This underlines the advantage of an antibody panel for neuroblastoma purging. The new antibody S-L 11.14, an IgG2a against small cell lung cancer which recognizes 90% of neuroblastoma cells purged 2.8 log.

Antibodies, Monoclonal↗
PubMed1989

Phenotypic heterogeneity studied by immunohistochemistry and aneuploidy in non-small cell lung cancers.

Non-small cell lung cancers (non-SCLC) differ from small cell lung cancers (SCLC) by many clinical features and prognosis. However, recent studies suggest that lung cancer heterogeneity frequently leads to the association of SCLC and non-SCLC in the same tumor. This phenotypic heterogeneity can be analyzed by immunohistochemistry using monoclonal antibodies (Mab) raised against differentiation related antigens. It may have clinical relevance inasmuch as the diversification of malignant cells is a well-known factor of tumor progression and may be due to chromosomal instability because inappropriate gene expression leads to the formation of antigens unrelated to cell lineage. Chromosomal instability in cancer leads to aneuploidy detectable by cell DNA content analysis. In a prospective study, we analyzed, in parallel, the expression of neuroendocrine related antigens by immunohistochemistry and the cell DNA content in frozen specimens from 40 patients who underwent complete surgical resection of primary non-SCLC in an attempt (a) to characterize the phenotypic heterogeneity and (b) to determine whether this heterogeneity is correlated with aneuploidy and clinical staging. Three Mabs were used in association as a marker of neuroendocrine antigen expression (S-L 11.14, MOC-1, and NE-25); reactivity of these Mabs in 9 SCLC and 3 lung carcinoid tissue sections was used as positive control. All SCLC and 2 of 3 lung carcinoids tested were homogeneously positive with Mabs S-L 11.14, MOC-1, and NE-25; 13 of 40 non-SCLC were homogeneously positive and 11 additional specimens focally positive with Mabs S-L 11.14, MOC-1, and NE-25. The frequency of this abnormal phenotype was significantly higher in poorly differentiated squamous cell carcinomas (chi 2 10.08; P less than 0.005), in clinical stage III non-SCLC (chi 2 5.93; P less than 0.02), and in tumors involving mediastinal lymph nodes (chi 2 5; P less than 0.03). The percentage of cells in the modal DNA of G0-G1 phase was significantly lower in non-SCLC homogeneously positive with Mabs S-L 11.14, MOC-1, and NE-25 [27.4 +/- 10.3% (SD)] in comparison with non-SCLC negative with these same Mabs [56.8 +/- 21.3%; P less than 0.01, Mann-Whitney U test]. We conclude that (a) mixed SCLC-non-SCLC differentiation is frequent and can be assessed by immunohistochemistry, (b) neuroendocrine differentiation in non-SCLC is mainly observed in poorly differentiated tumors and in advanced clinical stages, and that (c) this heterotopic phenotype is correlated with aneuploidy and has clinical implications.

Adult↗
PubMed1989

A monoclonal antibody (BL2-10D1) reacting with a bladder-cancer-associated antigen.

A hybridoma cell line secreting an IgM monoclonal antibody (MAb) was produced after immunizing a mouse with RT4 cells and a crude suspension of human bladder carcinoma cells (WHO grades II and III TCC). This MAb reacted with RT4 target cells derived from a human transitional bladder cancer but failed to react with a majority of non-bladder cancer cell lines. Immunohistological studies indicate that this MAb reacts inconstantly with normal bladder: in positive cases only a few superficial cells (5% to 10% umbrella cells) are stained but not intermediate or basal cells of the urothelium. This MAb was evaluated on 118 tumors: it reacted with tumor tissue in a majority of grade I (79.5%) and grade II papillary TCC (77.3%), less with grade III papillary TCC (45%) and very rarely with invasive non-papillary TCC (14%). In cases of flat lesions a strong reactivity of superficial, intermediate and/or basal layer cells was observed in 50% of moderate and severe dysplasia and in all cell layers of carcinomas in situ (CIS)(9/9).

Antibodies, Monoclonal↗
PubMed1988

Presence and characterization of insulin-like growth factor 1 receptors in human benign breast disease.

Insulin-like growth factor 1 binding sites were characterized in human benign breast disease. We demonstrated the presence of one high affinity binding site. Chemical cross-linking of [125I]IGF1 to benign breast disease membranes in reducing condition and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed one band with an apparent Mr of 130,000. The specificity of the binding was studied: IGF 2 was a good competitor whereas insulin competed for binding with a potency lower than 1/100 that of IGF1. This IGF1 binding corresponded to the previously described type I IGF receptor (IGF1-R). IGF1-R was assayed in 35 cases of benign breast disease and two samples of normal breast tissue. Forty-three per cent of the lesions were IGF1-R positive. The mean geometric level of specific binding was 1.98% in the whole population, it was significantly lower in adenofibromas (1.55%) than in epithelial hyperplasia (2.5%); it was 2% in dystrophic disease. IGF1-R was undetectable in normal tissue. Considering our previous results showing that almost all the breast cancers contained IGF1-R, these data suggest that the increase in IGF1-R could be a marker of malignant tumor development.

Adenofibroma↗
PubMed1988

S-L 11.14: a monoclonal antibody recognizing neuroectodermal tumors with possible value for bone marrow purging before autograft.

A new monoclonal antibody (S-L 11.14) raised against small cell lung cancer reacted with all but one neuroblastoma tumor cell sample tested and was relatively specific for such cells within the bone marrow. The ability of S-L 11.14 to eliminate neuroblastoma cells from the bone marrow with an immunomagnetic purging method was evaluated in an experimental model using the LAN.1 and SKNBE neuroblastoma cell lines as targets. Residual malignant cells after the purging procedure were quantified by the Hoechst staining method. The use of S-L 11.14 as a single reagent resulted in a 3-log elimination of malignant cells, a depletion equal to that obtained with a cocktail of five monoclonal antibodies currently used in clinical trials. The addition of the S-L 11.14 antibody to this cocktail did not enhance depletion.

Antibodies, Monoclonal↗
PubMed1988

[Phyllodes tumor of the breast in an 11-year-old child].

The authors describe a case of cystosarcoma phylloides of the breast in an 11-year-old girl. The clinical examination showed a voluminous painless tumour which had grown rapidly. Mammography revealed a dense imaging of this tumour with a 6 cm diameter. Surgical removal preserved the healthy tissues and gave a good morphological result. The histologic examination confirmed a double component phylloid tumour with a predominant mesenchymatous part.

Breast Neoplasms↗