119 research outputs found
Transmission of oocyte DNA damage to preimplantation embryos after in vivo mouse exposure to daunorubicin and cytarabine.
International audienceStudy question: Does oocyte DNA damage induced by a previous in vivo mouse exposure to chemotherapy agents is transmissible to preimplantation embryos?Summary answer: DNA damage was observed in preimplantation embryos issued from mice previously exposed to daunorubicin and cytarabine.What is known already: In acute leukemia, the emergency to start a chemotherapydon’t allow a fertility preservation at the time of diagnosis. Some authors have proposed to cryopreserve mature oocytes or embryos after a controlled ovarian stimulation applied shortly after the induction chemotherapy,which is mainly composed by daunorubicin and cytarabine, and reputated to be less gonadotoxic than alkylant agents. We previously observed DNA damage on mouse oocytes issued from antral follicles exposed in vivo to daunorubicin and cytarabine.Little is known about the risk of transmission of oocyte DNA damage to preimplantation embryos after fecundation of oocytes recently exposed to chemotherapy.Study design, size, duration: By three time, two groups of mice (n = 11) were exposed for four days to cytarabine (10 mg/kg IP) or every two days to daunorubicin (1 mg/kg IV). Each group was compared with a negative control group (n = 11) and with a positive control group (n = 11) injected with cyclophosphamide(75 mg/kg IP). Females were mated one week after exposure and preimplantation embryos were collected by flushing the oviducts.Participants/materials, setting, methods: 4 weeks female CD1 mice were mated one week after exposure for studying embryos conceived from oocytes exposed to chemotherapy at late pre-antral stage of follicular development.Cytotoxicity has been assessed by ovulation and fertilization rates and by embryo morphology. DNA embryonic damage was assessed by: (i) alkaline comet assay to quantify the tail DNA (ii) fluorescent immunohistochemical staining in blastomeres to quantify accumulating γH2AX foci.Main results and the role of chance: In mouse, a recent exposure to daunorubicin and cytarabine did not alter the ovarian response to controlled ovarian stimulation with no adverse impact on the fertilization rate and the number of embryo conceived. Ovulation and fertilization rates in mice previouslyexposed to daunorubicin and cytarabine were similar to those in our negative control group. One week after exposure, we observed with the comet assay a significant increase of embryonic DNA damage after exposure to daunorubicin (16.57 ± 1.3, p = 0.0003) and cytarabine (16.46 ± 1.4, p =0.0003) Vs 26.16 ± 2.5 after cyclophosphamide exposure (p < 0.0001) and 7,01 ± 1,1 in negative control group exposed to an injection of sterile saline solution. The analysis γ-H2AX on embryos showed a significant increase of foci corresponding to DNA double-strand breaks, after exposure to daunorubicin (7.97 ± 1.1; p = 0.001), cytarabine (6.47 ± 0.7, p = 0.0039), cyclophosphamide (5.92 ± 0.9; p = 0.0148) compared with negative control group (2,8 ±0,7).Limitations, reasons for caution: Mouse oocyte DNA is not exactly similar to human oocyte DNA, and would be more sensitive to genotoxic effects of chemotherapy agents. After chemotherapy, the kinetic of DNA repair before and after fertilization has to be studied by further assays in exposed oocyte andin embryos.Wider implications of the findings: DNA damage in preimplantation embryos conceived from oocytes exposed to chemotherapy at late pre-antral stage of follicular development lead us to hypothese a transmission of oocyte DNA damage to preimplantation embryo. In acute leukemia, we strongly adviseto not cryopreserve mature oocytes or embryo early after induction chemotherapy.Trial registration number: Experimental protocols and animal handling procedures were reviewed by the French National Ethics Committee on Animal Experimentation (N° 2017033010523688)
Pre-operative Concomitant Radio-chemotherapy in Bulky Carcinoma of the Cervix: A Single Institution Study
Objective To evaluate the treatment results of patients (pts) with FIGO stage IB2, IIA, IIB cervical carcinoma (CC) treated with pre-operative radio-chemotherapy, followed by extended radical hysterectomy. Methods Retrospective study of 148 women treated to the Institut Curie for operable FIGO Stage IB2 to IIB, biopsy proved CC. Among them, 70 pts, median age 46 years, were treated using the same regimen associating primary radio-cisplatinum based chemotherapy, intracavitary LDR brachytherapy, followed by extended radical hysterectomy. Kaplan-Meier estimates were used to draw survival curves. Comparisons of survival distribution were assessed by the log-rank test. Results Complete histological local-regional response was obtained in 56% of the pts (n = 39). Residual macroscopic or microscopic disease in the cervix was observed in 28 pts (40%). All but one had in-situ microscopic residual CC. Lateral residual disease in the parametria was also present in 9 pts, all with residual CC. Pelvic lymph nodes were free from microscopic disease in 56 pts (80%). Eight of 55 (11%) radiological N0 patients had microscopic nodal involvement, as compared to 6/15 (40%) radiological N1 (p = 0.03). Seventeen pts (25%) had residual cervix disease but negative nodes. After median follow-up of 40 months (range, 8–141), 38/70 patients (54.1%) are still alive and free of disease, 6 (8.6%) alive with disease, and 11 (15.8%) patients were lost for follow-up but free of disease. In Conclusion The treatment of locally advanced CC needs a new multidisciplinary diagnostic and treatment approach using new therapeutic arms to improve the survival and treatment tolerance among women presenting this disease
Evaluation of the dystrophin carboxy-terminal domain for micro-dystrophin gene therapy in cardiac and skeletal muscles in the DMDmdx rat model
Duchenne muscular dystrophy (DMD) is a muscle wasting disorder caused by mutations in the gene encoding dystrophin. Gene therapy using micro-dystrophin (MD) transgenes and recombinant adeno-associated virus (rAAV) vectors hold great promise. To overcome the limited packaging capacity of rAAV vectors, most MD do not include dystrophin carboxy-terminal (CT) domain. Yet, the CT domain is known to recruit α1- and β1-syntrophins and α-dystrobrevin, a part of the dystrophin-associated protein complex (DAPC), which is a signaling and structural mediator of muscle cells. In this study, we explored the impact of inclusion of the dystrophin CT domain on ΔR4-23/ΔCT MD (MD1), in DMDmdx rats, which allows for relevant evaluations at muscular and cardiac levels. We showed by LC-MS/MS that MD1 expression is sufficient to restore the interactions at a physiological level of most DAPC partners in skeletal and cardiac muscles, and that inclusion of the CT domain increases the recruitment of some DAPC partners at supra-physiological levels. In parallel, we demonstrated that inclusion of the CT domain does not improve MD1 therapeutic efficacy on DMD muscle and cardiac pathologies. Our work highlights new evidences of the therapeutic potential of MD1 and strengthens the relevance of this candidate for gene therapy of DMD
The Journey of SCAPs (Stem Cells from Apical Papilla), from Their Native Tissue to Grafting: Impact of Oxygen Concentration
Tissue engineering strategies aim at characterizing and at optimizing the cellular component that is combined with biomaterials, for improved tissue regeneration. Here, we present the immunoMap of apical papilla, the native tissue from which SCAPs are derived. We characterized stem cell niches that correspond to a minority population of cells expressing Mesenchymal stromal/Stem Cell (CD90, CD105, CD146) and stemness (SSEA4 and CD49f) markers as well as endothelial cell markers (VWF, CD31). Based on the colocalization of TKS5 and cortactin markers, we detected migration-associated organelles, podosomes-like structures, in specific regions and, for the first time, in association with stem cell niches in normal tissue. From six healthy teenager volunteers, each with two teeth, we derived twelve cell banks, isolated and amplified under 21 or 3% O2. We confirmed a proliferative advantage of all banks when cultured under 3% versus 21% O2. Interestingly, telomerase activity was similar to that of the highly proliferative hiPSC cell line, but unrelated to O2 concentration. Finally, SCAPs embedded in a thixotropic hydrogel and implanted subcutaneously in immunodeficient mice were protected from cell death with a slightly greater advantage for cells preconditioned at 3% O2
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Hysteresis in Audiovisual Synchrony Perception
International audienceThe effect of stimulation history on the perception of a current event can yield two opposite effects, namely: adaptation or hysteresis. The perception of the current event thus goes in the opposite or in the same direction as prior stimulation, respectively. In audiovisual (AV) synchrony perception, adaptation effects have primarily been reported. Here, we tested if perceptual hysteresis could also be observed over adaptation in AV timing perception by varying different experimental conditions. Participants were asked to judge the synchrony of the last (test) stimulus of an AV sequence with either constant or gradually changing AV intervals (constant and dynamic condition, respectively). The onset timing of the test stimulus could be cued or not (prospective vs. retrospective condition, respectively). We observed hysteretic effects for AV synchrony judgments in the retrospective condition that were independent of the constant or dynamic nature of the adapted stimuli; these effects disappeared in the prospective condition. The present findings suggest that knowing when to estimate a stimulus property has a crucial impact on perceptual simultaneity judgments. Our results extend beyond AV timing perception, and have strong implications regarding the comparative study of hysteresis and adaptation phenomena
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