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B Bonnotte

Publications and source records attributed to B Bonnotte.

At least 37 records · Page 2Linked to original sources
PubMed1998

Bcl-2-mediated inhibition of apoptosis prevents immunogenicity and restores tumorigenicity of spontaneously regressive tumors.

Tumor cell clones from a rat colon carcinoma differ in their tumorigenicity and immunogenicity. The PRO clones give rise to progressive tumors, whereas the REG clones yield tumors that regress in a few weeks through a specific immune response. REG cells were more sensitive than PRO cells to apoptosis triggered by serum withdrawal in vitro. Furthermore, a fraction of REG cells, but no PRO cells, underwent apoptosis in the hours following injection into syngeneic rats. To further analyze the role of apoptosis, we overexpressed the antiapoptotic protein Bcl-2 in REG cells. Unlike parental or fake-transfected REG cells, Bcl-2-overexpressing REG cells resisted serum withdrawal-induced apoptosis, did not undergo apoptosis at 48 h postinjection into naive syngeneic rats, and gave rise to progressive, metastatic, and lethal tumors. Interestingly, REG-bcl2 cells were rejected by syngeneic hosts that had been preimmunized by an injection of parental REG cells, indicating that Bcl-2 overexpression did not alter tumor cell sensitivity to the effector cells of the immune response. Taken together, these observations indicate that tumor cell apoptosis may contribute to immunogenicity.

Adenocarcinoma↗
PubMed1998

Cancer cell sensitization to fas-mediated apoptosis by sodium butyrate.

Cancer cells often resist Fas-mediated apoptosis even when the Fas receptor is expressed at the cell surface. We show here that human and rat colon cancer cells undergo massive apoptosis when they are exposed to soluble Fas ligand in the presence of sodium butyrate, an agent that induces by itself only a low rate of apoptosis. Sodium butyrate potentiates Fas-dependent apoptosis in seven out of eight colon cancer cell lines. Sodium butyrate does not increase Fas receptor cell surface expression and does not modify cell levels of Bcl-2, Bcl-xL, Bcl-xS and Bax. Sodium butyrate also induces tumor cell sensitization to the apoptotic effect of the combination of TNF-alpha and IFN-gamma, but it does not modify the level of the FADD/Mort1 adaptator molecule, at the connection between Fas- and TNF-dependent apoptosis pathways. Because the clinical toxicity of butyrate is low, its ability to enhance Fas-signal delivery in cancer cells could be of therapeutic interest.

Adaptor Proteins, Signal Transducing↗
PubMed1997

[Factitious hyperchloremia disclosing bromide poisoning. 4 cases].

BACKGROUND: When routine blood chemistry shows elevated chloride alone, another anion (bromide, iodine, fluoride) may be involved. CASE REPORTS: Hyperchloremia and decreased anion gap was observed in four patients. Chloremia ranged from 134 to 174 mmol/l at initial blood tests. Careful history taking led to the discovery of long-term use of calcium bromogalacto-glucomate. Specific assay with inductively coupled plasma mass spectrometry (ICPMS) confirmed the presence of bromide in the blood. Chloridemia returned to normal levels after discontinuing use of bromine. DISCUSSION: Bromism is not a common diagnosis. Risks include neurological and psychiatric disorders due to bromide diffusion through the blood-brain barrier. Clinical manifestations have been described including skin lesions, digestive intolerance, and fever. Bromide is contained in certain prescription drugs. Patients should be warned against the adverse effects of overuse.

Adult↗
PubMed1997

Severe right ventricular contraction asynchronism revealing a large pericardial effusion.

A gated blood-pool equilibrium radionuclide angiography was performed in a patient to determine the ejection fraction for doxorubicin cardiotoxicity evaluation. The phase image of the first harmonic of the Fourier analysis revealed a severe delay of the right ventricular contraction compared with that of the left ventricle. This right ventricular contraction asynchronism was due to a large pericardial effusion, confirmed by the presence of the halo sign on the summed gated images and by echocardiography. The phase delay moves towards normalization after pericardiocentesis. Although radionuclide angiocardiography is not the best method for identification of pericardial effusion, this diagnosis should be evoked when a severe homogenous delay of the right ventricular contraction is observed.

Cardiac Tamponade↗
PubMed1996

Inhibition of the human allogeneic mixed lymphocyte response by cyclosporin A: relationship with the IL-12 pathway.

Interleukin-12 (IL-12) is an important cytokine in the control of cell-mediated immunity. We have previously shown that endogenous IL-12 plays a role in the development of human allogeneic response. In the present study, we investigated the relationship between Cyclosporin A (CsA)-inhibitory effect and IL-12 pathway during human alloreaction in vitro. CsA addition at the sensitizing phase of primary mixed lymphocyte reaction (MLR) resulted in the inhibition of both p40 and p70 IL-12 production in a dose-dependent manner. In contrast, CsA had no effect on IL-12-receptor beta 1 chain (IL-12 R beta 1) expression in T cells induced upon allogeneic activation. Addition of exogenous IL-12 significantly restored CsA-inhibited alloreactive cytotoxic T lymphocyte (CTL) generation and had a marginal effect on T cell proliferative response. The IL-12-induced restoration of CTL generation was IFN gamma-mediated, as it was significantly altered when anti-IFN gamma was added. The restoration of CTL activity by exogenous IL-12 correlated with the capacity of this cytokine to partially restore granzyme B mRNA expression in alloreactive CTL. This study indicates that inhibition of IL-12 production is a novel additional mechanism for the inhibitory effect of CsA on the development of human allogeneic cytotoxic response.

Animals↗
PubMed1996

Serum interleukin-12 levels in patients undergoing allogeneic or autologous bone marrow transplantation.

Cytokines may be helpful in promoting hematopoietic reconstitution but have also an impact on the cellular interactions that contribute to GvHD and immunologic graft rejection. Because IL-12 is emerging as a central cytokine in immune response, we have investigated its levels in serum samples of patients undergoing bone marrow transplantation and transplant-related events. A double-antibody radioimmunoassay method for monitoring levels of endogenous IL-12, before and after allogeneic (27 patients) or autologous (19 patients) bone marrow transplantation, was used. The serum levels of IL-12 after allogeneic BMT were found to be relatively low (140-300 pg/ml) and similar to the IL-12 levels in the healthy donors (183 pg/ml). Seric IL-12 levels following autologous BMT (350 pg/ml) were higher than those observed in patients receiving an allogeneic BMT and in healthy donors. Our data indicate that the occurrence of GvHD and the development of infection after allogeneic BMT are not associated with IL-12 induction which suggests a possible down-regulation due to immunosuppressive treatment.

Adolescent↗
PubMed1994

A controlled trial of the tolerance of amphotericin B infused in dextrose or in Intralipid in patients with haematological malignancies.

Patients with haematological malignancies requiring an antifungal therapy were randomly assigned to receive amphotericin B diluted in either 5% dextrose or in fat emulsion (Intralipid). Twenty-one patients were included in each group. Mean duration of amphotericin B therapy was 8.4 days in the dextrose group and 12.8 days in the Intralipid group. Amphotericin B infusion induced chills in 16 of 21 patients in the dextrose group and in 5 of 21 in the Intralipid group (P = 0.0008). Serum creatinine increased > 75% from baseline in ten patients in the dextrose group compared with only two in the Intralipid group (P = 0.007). A > or = 50% decrease of creatinine clearance was observed in 14 of 21 patients in the dextrose group compared with seven of 21 patients in the Intralipid group (P = 0.025). No difference was found between the two groups with regard to potassium and sodium requirement. Among patients who did not receive magnesium before antifungal therapy, magnesium supplementation was required more frequently in the dextrose group (8/12 vs 2/11; P = 0.02). Concomitant amikacin dosage reduction was more frequent in the dextrose group due to nephrotoxicity (7/19 vs 2/20; P = 0.045). A similar difference in vancomycin dosage reduction was observed between the two groups (12/20 vs 5/19; P = 0.03).

Adult↗
PubMed1993

Efficacy and tolerance of an amphotericin B lipid (Intralipid) emulsion in the treatment of candidaemia in neutropenic patients.

The efficacy and tolerance of a new amphotericin B lipid emulsion (AmB-IL) in which amphotericin B was diluted in a lipid solution for parenteral nutrition (Intralipid) was assessed in fourteen episodes of candidaemia occurring in neutropenic patients. The strains isolated were Candida krusei (nine cases), Candida albicans (three cases), Candida parapsilosis (one case) and Candida lusitaniae (one case). An AmB-IL was administered at a mean dosage of 1.18 mg/kg/day (range 0.73-1.55) for 22 days (range 6-62). Flucytosine was added to AmB-IL in 12 patients (mean duration 10.6 days). Chills were noted in only 3/306 infusions of AmB-IL. A mild increase of serum creatinine level from 9.3 +/- 3 mg/L (baseline) to 10.9 +/- 3 mg/L (after completion of AmB-IL) and mild decrease of creatinine clearance from 83 +/- 28 mL/min to 56 +/- 21 mL/min were observed. These changes did not correlate with either daily or total dose of AmB-IL or length of therapy. Seven patients were cured and six improved (patients who subsequently died due to nonfungal cause) with AmB-IL. One patient died due to C. krusei pneumonia. In conclusion AmB-IL is a well-tolerated method of amphotericin B administration. It could facilitate the use of amphotericin B without impairing its efficacy for the treatment of candidaemia in neutropenic patients.

Adult↗
PubMed1993

Celiprolol pneumonitis.

We report on a patient who developed hypersensitivity pneumonitis during treatment with the beta-blocker, celiprolol. The clinical picture was a severe alveolitis, with compromised gas exchange. Inadvertent subsequent rechallenge with celiprolol led to recurrence of the pneumonitis, 10 weeks after drug readministration. Again, the pneumonitis was fully reversible. Lymphocytes were elevated in bronchoalveolar lavage, and progressively normalized upon discontinuation of the drug. This case is reminiscent of pneumonitis to other beta-blockers, which are reviewed here.

Adrenergic beta-Antagonists↗
PubMed1992

[Intra-alveolar hemorrhages in systemic diseases].

Alveolar haemorrhage is usually, but often belatedly, diagnosed in patients presenting with haemoptysis and radiological alveolar syndrome. Its occurrence frequently marks a turn for the worst in the course of a systemic disease, since its prognosis is sombre. Recognizing its early signs might enable treatment to be instituted and prognosis to be improved. In the presence of typical alveolar haemorrhage, if high-dose corticosteroid therapy and immunosuppressants do not improve the symptoms within 48 hours plasmapheresis must be started. Alveolar haemorrhage must be considered a vital emergency justifying this therapeutic approach without waiting for the hypothetical diagnosis of the underlying systemic disease.

Adolescent↗