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Biomedical subjects

D Seigneurin

Publications and source records attributed to D Seigneurin.

88 records · Page 5Linked to original sources
PubMed1977

[Cutaneous symptoms of thrombocytemia (author's transl)].

By the study of 4 personal cases and a review of the literature, the authors describe the symptoms which may complicate and even reveal an essential thrombocythemia. They are: painful symptoms which indicate a permanent or paroxystic vasculomotor syndrome by their localization and their course: -erythematous lesions of an inflammatory livedo type located on the legs and blue-red reticular spots on the sole of the foot: --occurrence of gangrene on finger ends or of necrotic ulcerations of the legs. Etiological conditions, exploration of primary hemostasis, physiopathology of the troubles are described. As for therapeutics the antiaggregants have a suspensive effect on the symptoms but only the control of the hematological status may allow recovery.

Adult↗
PubMedDate not supplied

["New cytology" and diagnosis of malignant tumors].

Cytology is an old method of diagnosis: it is the microscopical observation of cells in the aim of their identification, of the recognition of morphological abnormalities to obtain diagnosis or prognosis informations. During the last 20 years, new technics have been developed: 1) Immunocytochemistry permits the identification of the tissue or the organ of which a tumoral cell population is born, the determination of its stage of differentiation, its kinetic and the diagnosis of bone marrow or lymph node metastasis. 2) With in situ molecular biology, it becomes possible to detect, at the cell level, virus, oncogenes or chromosomic abnormalities. 3) Flow and image cytometry are easy means for DNA content determination and for an objective and reproducible cell definition. None of these methods are able, at this time, to replace the cytological analysis, but they are useful, sometimes necessary, for the diagnosis and the prognosis evaluation of malignancy.

Biomarkers, Tumor↗
PubMedDate not supplied

Identification of amylase crystalloids in cystic lesions of the parotid gland.

OBJECTIVE: To identify alpha-amylase crystalloid formations in parotid specimens obtained by fine needle aspiration. STUDY DESIGN: The study concerned three cases of sialadenitis with crystalloid formation observed between 1993 and 1998. In one of these cases, transmission electron microscopy, mass spectrometry and measurement of amylase activity were used to characterize the nature of the crystalloids. RESULTS: Light microscopy revealed the same crystalloid structure in all three cases. In one case, where the material was saved, a biochemical method made it possible to reveal high amylase activity, while protein electrophoresis and mass spectrometry were used to identify salivary alpha-amylase. CONCLUSION: Crystalloids of salivary alpha-amylase can be identified by May-Grünwald-Giemsa and Papanicolaou stain and can be rapidly confirmed through determination of amylase activity.

Adult↗
PubMedDate not supplied

CK20 gene expression: technical limits for the detection of circulating tumor cells.

The suitability of CK20 mRNA expression as a marker for the detection of minimum residual disease in patients with cancer of epithelial origin was evaluated. A sensitive nested RT-PCR assay with multiple replicates was optimised to detect a minimum number of circulating tumor cells expressing cytokeratin 20 (CK20) mRNA. Using this optimal procedure, we examined CK20 mRNA expression in ten epithelial and seven leukemic cell lines, in eight bladder tumors, in peripheral blood samples from 18 tumor patients and from 29 healthy controls and in 8 bone marrow samples from healthy donors. CK20 mRNA was found in 13 of 18 (72%) blood samples from patients with cancer of epithelial origin and in all the epithelial tumor cells tested. However, CK20 mRNA was also detected in 21 of 29 (72%) bloods, in 8 of 8 bone marrow samples from healthy donors and in 4 of 7 leukemic cell lines. These results highlight a requirement for either determination of threshold levels of CK20 normal expression or the development of quantitative techniques to distinguish between a tumor-specific CK20 gene expression and a low level background transcription of this marker. These results would also advise caution in using CK20 as a tumor specific marker in clinical investigations.

Biomarkers, Tumor↗
PubMedDate not supplied

Autocrine regulation of TPA-induced apoptosis in monoblastic cell-line U-937: role for TNF-alpha, MnSOD and IL-6.

The present studies were undertaken to analyse the factors regulating TPA-induced apoptosis. Treatment of the monoblastic U-937 cells with the phorbol ester, TPA, was found to induce apoptosis in two distinct phases. In phase I (from 0 to 72 hours following TPA induction), apoptotic cells appeared, despite the expression of high levels of the anti-apoptotic Bcl-2 protein. After 96 h. of TPA treatment (phase II), the percentage of apoptotic cells increased as did the cell differentiation stage. The first phase apoptotic response could be significantly reduced (70%) by treatment with anti-tumor necrosis factor-alpha (TNF-alpha) antibody. TNF-alpha protein required de novo RNA and protein synthesis and was found to be mediated by protein kinase and protein tyrosine kinases. Manganese superoxide dismutase (MnSOD) inhibited, whereas IL-6 increased TPA-induced apoptosis. These findings suggest that both TPA, via TNF-alpha synthesis, exerts its protective function intracellularly by inducing MnSOD production and IL-6 may be an effective adjunct to TNF-alpha in the clinic, increasing the antitumor potency of this cytokine.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMedDate not supplied

[Androgens and prolonged complete remissions in acute non lymphoblastic leukemias. Results of a systematic treatment with stanozolol associated with chemotherapy (author's transl)].

An androgen (stanozolol: 0,15 mg/kg/d) was systematically associated to the treatment of acute non lymphoblastic leukemias, since the beginning of induction therapy (vincristin, daunorubicin, prednisone) and throughout the maintenance period (6-mercaptopurine and methotrexate). Thirty-six patients less than 60 years old (median age: 44 years) presenting with acute non-lymphoblastic leukemia were entered to the study. Sixteen achieved complete remission (C.R.), i.e. 44% of the whole and 53% of treated patients. Out of 16 patients with complete remission, 4 relapsed during the observation period which lasted 4-1/2 years. The stability of the hematologic equilibrium in patients in C.R. is the main finding of the present study. The actuarial curve of the duration of the first complete remission reaches a "plateau"; after the 8th month only one relapse was observed in 9 patients. The rate of C.R. at 2 years is 76 +/- 23%. As compared to the results from other schedules of treatment, this rate appears significantly better, specially in the case of immunotherapy (p less than 0,001). A prospective randomized study is now suggested as to confirm this result; its therapeutic and theoretical basis and perspectives are discussed.

Adolescent↗
PubMedDate not supplied

[Heterophil antibody negative infectious mononucleosis due to Epstein-Barr virus. A clinical, hematological and serological study of 14 cases (author's transl)].

Fourteen patients admitted to the hospital for heterophil antibody negative infectious mononucleosis (IM) were studied; the causative agent was Epstein-Barr virus, as confirmed by the presence of anti-VCA antibodies (IgG and IgM) and the absence of anti-EBNA antibodies. The patients were from 2 to 69 years old, 7 being less than 10 years old while 4 were more than 45 years old. In all cases, asthenia and adenopathy were found and a deterioration in liver functions was present whenever it was looked for; jaundice occurred in 3 patients. In 6 cases fever persisted for several weeks. Leukocytosis and a high level of mononuclear cells were present in 8 patients and atypical lymphocytes in 10. Anti-EA titers were found to be high in the severe forms of illness. Clinical and laboratory features of these 14 heterophil negative IM patients were compared with a group of 21 heterophil positive IM patients studied under the same conditions; the most striking differences between the two groups were the frequency of patients under 10 and over 45 years old in the heterophil negative group, the frequency of abnormal liver function tests and of persistent fever, and a lower frequency of atypical lymphocytes.

Adult↗
PubMedDate not supplied

[Must we teach, today, the MCHC (Mean Corpuscular Haemoglobin Concentration)? (author's transl)].

Automatic cell counters introduce a new interpretation of the MCHC. The automatic MCHC does not fall in cases of thalassemia or of iron deficiency, except in the severest; so it serves now little practical purpose. The manual MCHC continues to be a useful index of hypochromia, but does not reflect the true haemoglobin concentration in red cells, and it remains less and less in use.

Anemia, Hypochromic↗
PubMedDate not supplied

Coexpression of multidrug resistance involve proteins: a flow cytometric analysis.

Cross resistance to multiple natural cytotoxic products represents a major obstacle in myeloblastic acute leukaemia (AML). Multidrug resistance (MDR) often involves overexpression of plasma membrane drug transporter P-glycoprotein (PGP) or the resistance associated protein (MRP). Recently, a protein overexpressed in a non-PGP MDR lung cancer cell line and termed lung resistance related protein (LRP) was identified. These proteins are known to be associated with a bad prognosis in AML. We have developed a triple indirect labelling analysed by flow cytometry to detect the coexpression of these proteins. Since no cell line expressing all three antigens is known, we mixed K562 cells (resistant to Adriblastine, PGP+, MRP-, LRP-) with GLC4 cells (resistant to Adriblastine, PGP-, MRP+, LRP+) to create a model system to test the method. The antibodies used were UIC2 for PGP, MRPm6 for MRP and LRP56 for LRP. They were revealed by Fab'2 coupled with Fluoresceine-isothiocyanate, Phycoerythrin or Tricolor with isotype specificity. Cells were fixed and permeabilized after PGP labelling because MRPm6 and LRP56 recognize intracellular epitopes. PGP and LRP were easily detected. MRP is expressed at relatively low levels and was more difficult to detect because in the triple labelling the non specific staining was higher than in a single labelling. Despite the increased background in the triple labelling we were able to detect coexpression of PGP, MRP, LRP by flow cytometry. This method appears to be very useful to detect coexpression of markers in AML. Such coexpression could modify the therapeutic approach with revertants.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

PKH26 probe in the study of the proliferation of chemoresistant leukemic sublines.

Proliferative status and multidrug resistance status are key predictors of therapeutic outcome in acute myeloid leukemia. Although classical methods for proliferative assessment such as tritiated thymidine or BrdUrd incorporation, are correlated with treatment outcome, they are time consuming and difficult to standardize. As an alternative, we have evaluated the use of a dye dilution method using PKH26 to determine rate and extent proliferation in drug sensitive and resistant cell lines. When cells labelled with this fluorescent membrane intercalating dye divide, each resulting daughter cell receives half of the dye. Using flow cytometric analysis, it is possible to estimate the number of cells having undergone different numbers of cell divisions. Four different questions were addressed in these studies: a) does PKH26 give stable and reproducible labelling? b) does labelling with PKH26 alter cellular proliferation characteristics? c) is PKH26 a substrate for PGP and MRP? d) does PKH26 labelling alter PGP expression and/or PGP activity? We found that PKH26 labelling is stable, reproducible and has no effect on cell proliferation. It does not modify PGP activity or expression, nor does it appear to be a substrate for PGP or MRP, since the rate of decrease in fluorescence intensity is similar for sensitive and resistant cells which are proliferating at the same rate. Using the dye dilution method, it is possible to simultaneously assess PGP, proliferative status, and level of PGP expression. We conclude that the methods developed here provide a simpler, more complete means for assessment of the effects of the drug therapy on sensitive and resistant cell populations in patients with hematologic malignancies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗