Biomedical subjects

V Combaret

Publications and source records attributed to V Combaret.

62 records · Page 4Linked to original sources

PubMed1988

[The significance of immunological analysis for the detection of residual neuroblasts in bone marrow].

Immunological analysis is complementary to morphological investigation to detect bone marrow (BM) metastases in neuroblastoma patients. It is essential at time of BM harvest for an autograft, since it is the only examination which allows a precise evaluation of the graft contamination by malignant cells. Simple indirect immunofluorescence staining with anti-neuroblastoma monoclonal antibodies (UJ13A and HSAN 1-2) allows a final detection of about 1% malignant cells in the BM, and 1% when cells are gathered in clumps. The use of an immunocytochemical method (alkaline phosphatase) together with double immunofluorescence staining permits to detect as few as one residual neuroblastoma cell in 10(4) normal ones. These two methods used together have allowed to assess the neuroblastoma nature of rare isolated cells with pseudo-lymphocytic aspect.

Alkaline Phosphatase↗

PubMed1987

Experimental evaluation of an immunomagnetic bone marrow purging procedure using the Burkitt lymphoma model.

In order to test the numerous variable biological parameters which may contribute to the efficiency of the immunomagnetic depletion method, experiments have been carried out with different Burkitt lymphoma cell lines. The Hoechst dye method, a sensitive assay able to detect 3 log elimination, and a liquid culture assay suitable for identifying an elimination greater than 4 logs, were used to measure malignant cell elimination. These assays showed that the separation of bone marrow mononuclear cells on Ficoll-hypaque, the use of beads in excess, and a double treatment of the samples are needed to obtain optimal depletion of malignant cells. Under these conditions, the immunomagnetic procedure is capable of depleting 1% tumour cell infiltration at the lower limit of detection of a very sensitive culture assay (i.e. greater than 4 log elimination).

Bone Marrow Cells↗

PubMedDate not supplied

Isolated intraspinal relapse of neuroblastoma after autologous bone marrow transplantation.

Neuroblastoma may present with spinal cord compression due to dumbbell extension of thoracic or abdominal disease. Isolated intraspinal involvement as the sole site of relapse is rare. Two infants with poor-prognosis stage IV neuroblastoma presented early after high-dose therapy and autologous bone marrow transplant with isolated spinal relapse heralded by misleading symptoms. The rarity of such isolated relapses is reviewed, and an etiologic hypothesis is proposed.

Bone Marrow Transplantation↗

PubMedDate not supplied

Initial management of advanced Burkitt lymphoma in children: is there still a place for surgery?

This retrospective study compared the overall survival, the event-free survival, and the timing of chemotherapy in patients with advanced Burkitt lymphoma with and without laparotomy. Thirty-five patients with advanced abdominal Burkitt lymphoma treated at least partially at the Centre Léon Bérard between 1981 and 1992 were included in this study. The diagnosis was obtained by laparotomy (LAP group) in 21 patients (17 stage III, 4 stage IV) and by other methods (non-LAP group) in 14 patients (5 stage III, 9 stage IV). The overall survival (71 and 93%) and the event-free survival (66 and 79%) were similar in the LAP and non-LAP groups, and the relapse rate was five (three local) in the LAP group compared with three (none local) in the non-LAP group. The local complication rate (9 of 21 versus 2 of 14) and the toxic death rate (2 of 21 versus 1 of 14) were slightly higher in the LAP group. Laparotomy also caused delays in therapy and increased the overall hospital stay. The mean interval from diagnosis to the start of the fourth course of chemotherapy was 57 days compared with 48 days and the average hospital stay was 44.4 days compared with 39 days for the LAP and non-LAP groups, respectively. Because advanced Burkitt lymphoma can be diagnosed by fine-needle aspiration, and chemotherapy cures more than 80% of the patients, there is no need for initial surgery, apart from acute emergencies. Furthermore, laparotomy delay chemotherapy and might reduce the survival rate.

Adolescent↗

PubMedDate not supplied

Can MIBG scan replace the need for bone marrow assessment at diagnosis and reassessment in stage 4 neuroblastomas?

UNLABELLED: Complete staging (extensive marrow investigation and meta-iodo benzylguanine (MIBG) scan) is considered as mandatory both at diagnosis and after chemotherapy for assessment of metastases in neuroblastomas. However the correlation between bone marrow invasion and uptake of MIBG at metastatic sites remains unclear. This study investigates whether MIBG alone is sufficiently sensitive to make these procedures redundant. PATIENTS AND METHODS: 20 children over one year of age, with histologically proven metastatic neuroblastoma were studied. Extensive bone marrow assessment and MIBG bone scan performed both at diagnosis and after completion of induction chemotherapy were reviewed. RESULTS: At diagnosis metastases were detected by marrow investigation alone in 2, MIBG alone in 2 and both procedures in 16. After induction chemotherapy metastases were detected by only marrow investigation in 2, by only MIBG in 3, by both procedures in 6 patients, and by none in 9. CONCLUSIONS: Whether marrow investigations and MIBG scan explore the same phenomenon remains unclear. However it appears that marrow disease that is histologically detectable may remain MIBG negative both at diagnosis and after treatment. Both procedures are still justified at time of diagnosis and evaluation of response.

3-Iodobenzylguanidine↗

PubMedDate not supplied

TNF alpha enhancement of NK and LAK cell functions induced by high-dose IL-2 in human peripheral blood mononuclear cells from patients pretreated with alpha IFN + IL-2.

In this study we analyzed the induction of NK and LAK cell functions by TNF alpha, alone or combined with IL-2, in 4 days in vitro culture of PBMC from patients treated with alpha IFN + IL-2. Although the MN cell recovery after 4 days culture was very similar with TNF alpha alone or with IL-2 alone, TNF alpha did not maintain nor induce LAK or NK activities of in vivo preactivated PBMC. When compared to preculture values, TNF alpha alone induced a preferential outgrowth of CD4+ T cells together with a decrease of CD8+ T cells, NK cells and IL-2R (p55)-expressing cells. The combination of TNF alpha (100 ng) and high dose IL-2 (9,000 IUg/ml) did not improve the MN cell recovery after 4 days culture; but increased IL-2-induced NK activities in PBMC from 6/7 patients, and IL-2-induced LAK activities in 4/7 patients. However, these variations were not significant. The combination of TNF alpha and lower doses of IL-2, ranging from 150 IU/ml to 30 IU/ml, did not modify MN cell recovery in culture nor IL-2-induced NK and LAK cell activities. When compared to paired samples cultured with IL-2 alone, the combination of TNF alpha with all doses of IL-2 did not modify the distribution of T and NK cells, but increased the expression of CD8 on NK cells. Furthermore, the combination of TNF alpha and IL-2 increased the expression of IL-2R (p55) on PBMC but the expression of this receptor was restricted to CD4+ T cells and did not appear on NK cells.

Antigens, CD↗

PubMedDate not supplied

Functional and phenotypic modifications induced by IL-4, as single agent or in combination with IL-2, on PBMC preactivated in vivo by alpha-interferon + interleukin-2 therapy.

The effect of human IL-4, used as a single agent or in combination with low or high dose IL-2, upon LAK-cell proliferation and activation has been tested on PBMC from patients treated with alpha 2-IFN and IL-2. Four days in vitro culture with IL-4 did not induce any LAK-cell activation; IL-4 induced the proliferation of CD3+ CD4+ T-cells, but decreased the percentage of NK cells in culture samples. When combined with high dose IL-2, IL-4 improved the recovery of MN cell without modification of T-cell subsets; however, IL-4 had no major effect on IL-2-induced NK or LAK cell activity. The combination of IL-4 and low dose IL-2 still significantly improved the total MN cell recovery but did not modify the distribution of T and NK lymphocytes; IL-4 inhibited low dose IL-2-induced NK and LAK cell activity, and increased the BL-esterase activity induced by high or low dose IL-2. The combination of IL-4 and IL-2 did not induce any large variation in the percentage of IL-2R (p55) expressing cells. In all tested conditions, IL-2R (p55) was mainly expressed on CD4+ T cells; less than 2% of the cells coexpressed the NK cell marker CD56 and IL-2R (p55). The effect of IL-4 upon IL-2-induced LAK cell expansion is thus very different on PBMC pre-activated in vivo by alpha IFN + IL-2 therapy than on PBMC pre-treated in vitro with IL-2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Expression of integrin and CD44 adhesion molecules on neuroblastoma: the relation to tumor aggressiveness and embryonic neural-crest differentiation.

The immunohistological expression of integrins and CD44 cell adhesion molecule was analyzed on neuroblastoma (NB) specimens to study the potential role of these molecules in normal differentiation and in the transformation of neural crest derivatives. None of the specimens expressed the alpha 5 beta 1 integrin heterodimer; the expression of alpha 3 beta 1 heterodimer was maintained during all stages of differentiation; alpha 1 beta 1 heterodimer was expressed on undifferentiated neuroblasts and on Schwann cells, but was lost on ganglion cells. In contrast alpha 2 beta 1, alpha 6 beta 1, alpha 6 beta 4 and alpha V beta 1 expression was usually restricted to cells differentiated in the Schwann cell lineage. Alpha V beta 3 was expressed on tumors developed in the mediastinum. CD44 was strongly detected on differentiated ganglioneuroblastomas, stage 1 and 2 ganglioneuromas, as well as low-grade stage 4S NB and normal neuroblasts migrating in the fetal adrenal gland. CD44 expression was observed on Schwann cells and ganglion cells; in contrast, it was expressed on only 50% stage 3 and 4 undifferentiated NB. None of these specimens expressed exons V5, V7 or V6. In a few specimens, an intracellular expression of exons V8-V10 was observed in ganglion cells. The expression of CD44 on NB may reflect its pattern of expression on sympatho-adrenal precursors and arrest differentiation at these stages. Conversely, CD44 expression may be silenced during malignant transformation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗