Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
1.
BMC Med Ethics ; 22(1): 95, 2021 07 17.
Article in English | MEDLINE | ID: mdl-34273983

ABSTRACT

BACKGROUND: Informed consent forms for clinical research are several and variable at international, national and local levels. According to the literature, they are often unclear and poorly understood by participants. Within the H2020 project CORBEL-Coordinated Research Infrastructures Building Enduring Life-science Services-clinical researchers, researchers in ethical, social, and legal issues, experts in planning and management of clinical studies, clinicians, researchers in citizen involvement and public engagement worked together to provide a minimum set of requirements for informed consent in clinical studies. METHODS: The template was based on a literature review including systematic reviews and guidelines searched on PubMed, Embase, Cochrane Library, NICE, SIGN, GIN, and Clearinghouse databases, and on comparison of templates gathered through an extensive search on the websites of research institutes, national and international agencies, and international initiatives. We discussed the draft versions step-by-step and then we referred to it as the "matrix" to underline its modular character and indicate that it allows adaptation to the context in which it will be used. The matrix was revised by representatives of two international patient groups. RESULTS: The matrix covers the process of ensuring that the appropriate information, context and setting are provided so that the participant can give truly informed consent. It addresses the key topics and proposes wording on how to clarify the meaning of placebo and of non-inferiority studies, the importance of individual participants' data sharing, and the impossibility of knowing in advance how the data might be used in future studies. Finally, it presents general suggestions on wording, format, and length of the information sheet. CONCLUSIONS: The matrix underlines the importance of improving the process of communication, its proper conditions (space, time, setting), and addresses the participants' lack of knowledge on how clinical research is conducted. It can be easily applied to a specific setting and could be a useful tool to identify the appropriate informed consent format for any study. The matrix is mainly intended to support multicentre interventional randomized clinical studies, but several suggestions also apply to non-interventional research.


Subject(s)
Clinical Studies as Topic , Informed Consent , Humans , Information Dissemination , Research Design , Research Personnel
2.
Int J Infect Dis ; 103: 525-526, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33333249

ABSTRACT

During epidemic periods, HCW are vulnerable. In Africa, cohort studies implemented by the Institut Pasteur International Network in five countries showed after 3-month follow-up around 40% of the HCW have been infected by the SARS-CoV-2. So advocacy for HCW protection strategy need to be fostered and sustained by the health authorities all over the African continent.


Subject(s)
COVID-19/prevention & control , Health Personnel , SARS-CoV-2 , Africa/epidemiology , Cohort Studies , Epidemics , Humans , Personal Protective Equipment
3.
F1000Res ; 7: 138, 2018.
Article in English | MEDLINE | ID: mdl-29623192

ABSTRACT

Background: In recent years, a cultural change in the handling of research data has resulted in the promotion of a culture of openness and an increased sharing of data. In the area of clinical trials, sharing of individual participant data involves a complex set of processes and the interaction of many actors and actions. Individual services and tools to support data sharing are becoming available, but what is missing is a detailed, structured and comprehensive list of processes and subprocesses involved and the tools and services needed. Methods: Principles and recommendations from a published consensus document on data sharing were analysed in detail by a small expert group. Processes and subprocesses involved in data sharing were identified and linked to actors and possible supporting services and tools. Definitions adapted from the business process model and notation (BPMN) were applied in the analysis. Results: A detailed and comprehensive tabulation of individual processes and subprocesses involved in data sharing, structured according to 9 main processes, is provided. Possible tools and services to support these processes are identified and grouped according to the major type of support. Conclusions: The identification of the individual processes and subprocesses and supporting tools and services, is a first step towards development of a generic framework or architecture for the sharing of data from clinical trials. Such a framework is needed to provide an overview of how the various actors, research processes and services could interact to form a sustainable system for data sharing.

4.
BMJ Open ; 7(12): e018647, 2017 Dec 14.
Article in English | MEDLINE | ID: mdl-29247106

ABSTRACT

OBJECTIVES: We examined major issues associated with sharing of individual clinical trial data and developed a consensus document on providing access to individual participant data from clinical trials, using a broad interdisciplinary approach. DESIGN AND METHODS: This was a consensus-building process among the members of a multistakeholder task force, involving a wide range of experts (researchers, patient representatives, methodologists, information technology experts, and representatives from funders, infrastructures and standards development organisations). An independent facilitator supported the process using the nominal group technique. The consensus was reached in a series of three workshops held over 1 year, supported by exchange of documents and teleconferences within focused subgroups when needed. This work was set within the Horizon 2020-funded project CORBEL (Coordinated Research Infrastructures Building Enduring Life-science Services) and coordinated by the European Clinical Research Infrastructure Network. Thus, the focus was on non-commercial trials and the perspective mainly European. OUTCOME: We developed principles and practical recommendations on how to share data from clinical trials. RESULTS: The task force reached consensus on 10 principles and 50 recommendations, representing the fundamental requirements of any framework used for the sharing of clinical trials data. The document covers the following main areas: making data sharing a reality (eg, cultural change, academic incentives, funding), consent for data sharing, protection of trial participants (eg, de-identification), data standards, rights, types and management of access (eg, data request and access models), data management and repositories, discoverability, and metadata. CONCLUSIONS: The adoption of the recommendations in this document would help to promote and support data sharing and reuse among researchers, adequately inform trial participants and protect their rights, and provide effective and efficient systems for preparing, storing and accessing data. The recommendations now need to be implemented and tested in practice. Further work needs to be done to integrate these proposals with those from other geographical areas and other academic domains.


Subject(s)
Biomedical Research/standards , Clinical Trials as Topic , Consensus , Information Dissemination/methods , Advisory Committees , Humans
5.
Oncotarget ; 8(34): 56228-56242, 2017 Aug 22.
Article in English | MEDLINE | ID: mdl-28915586

ABSTRACT

Hepatitis C virus (HCV) is a leading cause of liver diseases including the development of hepatocellular carcinoma (HCC). Particularly, core protein has been involved in HCV-related liver pathologies. However, the impact of HCV core on signaling pathways supporting the genesis of HCC remains largely elusive. To decipher the host cell signaling pathways involved in the oncogenic potential of HCV core, a global quantitative phosphoproteomic approach was carried out. This study shed light on novel differentially phosphorylated proteins, in particular several components involved in translation. Among the eukaryotic initiation factors that govern the translational machinery, 4E-BP1 represents a master regulator of protein synthesis that is associated with the development and progression of cancers due to its ability to increase protein expression of oncogenic pathways. Enhanced levels of 4E-BP1 in non-modified and phosphorylated forms were validated in human hepatoma cells and in mouse primary hepatocytes expressing HCV core, in the livers of HCV core transgenic mice as well as in HCV-infected human primary hepatocytes. The contribution of HCV core in carcinogenesis and the status of 4E-BP1 expression and phosphorylation were studied in HCV core/Myc double transgenic mice. HCV core increased the levels of 4E-BP1 expression and phosphorylation and significantly accelerated the onset of Myc-induced tumorigenesis in these double transgenic mice. These results reveal a novel function of HCV core in liver carcinogenesis potentiation. They position 4E-BP1 as a tumor-specific target of HCV core and support the involvement of the 4E-BP1/eIF4E axis in hepatocarcinogenesis.

6.
J Hepatol ; 59(6): 1160-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23928402

ABSTRACT

BACKGROUND & AIMS: The mechanisms by which fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) develop during chronic hepatitis C virus (HCV) infection are not fully understood. We previously observed that HCV core protein induced a TGF-ß-dependent epithelial mesenchymal transition, a process contributing to the promotion of cell invasion and metastasis by impacting TGF-ß1 signalling. Here we investigated HCV core capacity to drive increased expression of the active form of TGF-ß1n transgenic mice and hepatoma cell lines. METHODS: We used an in vivo model of HCV core expressing transgenic mice. RESULTS: We observed that about 50% of genes deregulated by core protein expression were TGF-ß1 target genes. Active TGF-ß levels were increased in HCV core transgenic mouse livers. Overexpression of core protein in hepatoma cells increased active TGF-ß levels in culture supernatants and induced Smad2/3 phosphorylation, thus reflecting activation of the TGF-ß signaling pathway. Moreover, our data showed the implication of thrombospondin-1 in core-dependent TGF-ß activation. Finally, hepatoma cells expressing HCV core could activate stellate cells in co-culture and this activation was TGF-ß dependent. CONCLUSIONS: Collectively, these data delineate a novel paradigm where HCV may be related to liver pathogenesis through its ability to induce a local, intrahepatic TGF-ß activation. They argue for a dual impact of HCV core on liver fibrosis and liver carcinogenesis: HCV core could act both as autocrine and paracrine factor modulating TGF-ß responses within hepatocytes and in stromal environment through TGF-ß activation.


Subject(s)
Hepacivirus/physiology , Hepatocytes/physiology , Thrombospondin 1/physiology , Transforming Growth Factor beta/physiology , Animals , Humans , Mice , Mice, Transgenic
8.
PLoS One ; 4(2): e4355, 2009.
Article in English | MEDLINE | ID: mdl-19190755

ABSTRACT

BACKGROUND: Chronic hepatitis C virus (HCV) infection and associated liver cirrhosis represent a major risk factor for hepatocellular carcinoma (HCC) development. TGF-beta is an important driver of liver fibrogenesis and cancer; however, its actual impact in human cancer progression is still poorly known. The aim of this study was to investigate the role of HCC-derived HCV core natural variants on cancer progression through their impact on TGF-beta signaling. PRINCIPAL FINDINGS: We provide evidence that HCC-derived core protein expression in primary human or mouse hepatocyte alleviates TGF-beta responses in terms or growth inhibition or apoptosis. Instead, in these hepatocytes TGF-beta was still able to induce an epithelial to mesenchymal transition (EMT), a process that contributes to the promotion of cell invasion and metastasis. Moreover, we demonstrate that different thresholds of Smad3 activation dictate the TGF-beta responses in hepatic cells and that HCV core protein, by decreasing Smad3 activation, may switch TGF-beta growth inhibitory effects to tumor promoting responses. CONCLUSION/SIGNIFICANCE: Our data illustrate the capacity of hepatocytes to develop EMT and plasticity under TGF-beta, emphasize the role of HCV core protein in the dynamic of these effects and provide evidence for a paradigm whereby a viral protein implicated in oncogenesis is capable to shift TGF-beta responses from cytostatic effects to EMT development.


Subject(s)
Epithelium/pathology , Liver Neoplasms/pathology , Liver Neoplasms/virology , Mesoderm/pathology , Transforming Growth Factor beta/pharmacology , Viral Core Proteins/metabolism , Animals , Cell Death/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Epithelium/drug effects , Hepatocytes/drug effects , Hepatocytes/metabolism , Hepatocytes/virology , Humans , Mesoderm/drug effects , Mice , Mutant Proteins/metabolism , Smad3 Protein/metabolism
9.
Virus Res ; 125(1): 79-87, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17267064

ABSTRACT

Hepatitis C virus (HCV) core protein has been shown to exhibit several biological properties which suggest an important role in liver pathogenesis and carcinogenesis. During a previous study, we showed that core mutants, isolated from tumour, could directly interact with PKR and maintain it in an activated form. In the present report, we have further investigated this interaction and mapped the core and PKR domains involved. Using glutathion S-transferase fusion protein harbouring the different domains of core or PKR, we determined that the N-terminal 1-58 amino acid (aa) of core protein and the N-terminal 1-180 aa of PKR are responsible for this direct interaction. Using this system we also confirmed that the core-PKR interaction induced PKR autophosphorylation. Furthermore, we found that core protein co-localized and co-immunoprecipitated with PKR in cells expressing a full-length HCV replicon, thus confirming that this interaction occurs when all HCV proteins are expressed. Considering that the activation of PKR has been observed in some cancer cell lines and tissues, it suggests that, depending on the cellular context, PKR may stimulate or inhibit cell proliferation. The precise mapping of core-PKR interaction provides new data to study the molecular mechanism underlying HCV pathogenesis.


Subject(s)
Hepacivirus/chemistry , RNA, Double-Stranded/metabolism , Viral Core Proteins/metabolism , eIF-2 Kinase/metabolism , Protein Structure, Tertiary , Viral Core Proteins/genetics
10.
J Infect Dis ; 193(7): 996-1004, 2006 Apr 01.
Article in English | MEDLINE | ID: mdl-16518762

ABSTRACT

BACKGROUND: The liver stage of the human malaria parasite Plasmodium falciparum is the least known, yet it holds the greatest promise for the induction of sterile immunity and the development of novel drugs. Progress has been severely limited by the lack of adequate in vitro and in vivo models. METHODS: Recently, it was found that immunodeficient mice transgenic for the urokinase plasminogen activator allow survival of differentiated human hepatocytes. We confirm this finding but show that hepatocyte survival is short lived unless nonadaptive defenses are simultaneously depleted. RESULTS: By controlling macrophages and NK cells, we readily effected the long-term secretion of human serum albumin and human alpha-1 antitrypsin in mouse serum (at 3 months, the proportion of repopulated mice increased from 0% to 60% and from 22% to 80%, respectively; P<.0001). P. falciparum sporozoites delivered intravenously into mice readily infected transplanted human hepatocytes and developed into liver schizonts. Their size was twice as large as what was seen in vitro and was comparable to that found in humans and chimpanzees. CONCLUSION: These results emphasize the importance of nonadaptive defenses against xenotransplantation and lead to development of small laboratory models that, because they can harbor human hepatocytes, provide novel opportunities to study intrahepatic pathogens, such as those causing malaria and hepatitis.


Subject(s)
Hepatocytes/transplantation , Liver/parasitology , Plasmodium falciparum/growth & development , Animals , Clodronic Acid/administration & dosage , Clodronic Acid/toxicity , Hepatocytes/parasitology , Killer Cells, Natural/immunology , Macrophages/drug effects , Macrophages/immunology , Mice , Mice, SCID , Mice, Transgenic , Models, Animal , Serum Albumin/analysis , Transplantation, Heterologous , alpha 1-Antitrypsin/analysis
11.
Oncogene ; 24(40): 6119-32, 2005 Sep 08.
Article in English | MEDLINE | ID: mdl-16007207

ABSTRACT

Hepatitis C virus (HCV) is a major risk factor for human hepatocellular carcinoma (HCC) but the mechanisms underlying HCV-induced carcinogenesis are still poorly understood. We have hypothesized that viral variants, selected during long-term infection, might contribute to cellular transformation. To address this issue, we have investigated the effect of natural HCV core variants isolated from liver tumors (T), or their non-tumor (NT) counterparts, on the tumor growth factor-beta (TGF-beta) pathway, a major regulator of cellular proliferation, differentiation and apoptosis. We have found a significant reduction in TGF-beta reporter gene activity with the expression of core sequences isolated from liver tumors. In contrast, moderate or no effects were observed with non-tumor mutants or a core reference sequence. The molecular mechanisms have been characterized and involved the inhibition, by tumor-derived cores, of the DNA-binding activity of the Smad3/4 transcription factors complex. This inhibition occurs through a direct interaction between the central domain (amino acids 59-126) of tumor-derived core and the MH1 DNA-binding domain of Smad3, thus preventing its binding to DNA. We have therefore identified a new cell-signaling pathway targeted by HCV core and inhibited by tumor-derived core sequences. These results suggest that during chronic infection, there is selection of viral variants that may promote cell transformation by providing, to clonally expanding cells, resistance to TGF-beta antiproliferative effects.


Subject(s)
Carcinoma, Hepatocellular/virology , DNA-Binding Proteins/physiology , Hepacivirus/genetics , Liver Neoplasms/virology , Trans-Activators/physiology , Transforming Growth Factor beta/physiology , Viral Core Proteins/physiology , Amino Acid Sequence , Carcinoma, Hepatocellular/physiopathology , Cell Transformation, Neoplastic , Hepacivirus/physiology , Humans , Liver Neoplasms/physiopathology , Molecular Sequence Data , Mutation , Protein Binding , Protein Structure, Tertiary , Signal Transduction , Smad3 Protein , Smad4 Protein , Tumor Cells, Cultured , Viral Core Proteins/genetics
12.
Hepatology ; 38(1): 114-22, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12829993

ABSTRACT

Allogenic hepatocyte transplantation or autologous transplantation of genetically modified hepatocytes has been used successfully to correct congenital or acquired liver diseases and can be considered as an alternative to orthotopic liver transplantation. However, hepatocytes are neither easily maintained in culture nor efficiently genetically modified and are very sensitive to dissociation before their reimplantation into the recipient. These difficulties have greatly limited the use of an ex vivo approach in clinical trials. In the present study, we have shown that primary human and rat hepatocytes can be efficiently transduced with a FLAP lentiviral vector without the need for plating and culture. Efficient transduction of nonadherent primary hepatocytes was achieved with a short period of contact with vector particles, without modifying hepatocyte viability, and using reduced amounts of vector. We also showed that the presence of the DNA FLAP in the vector construct was essential to reach high levels of transduction. Moreover, transplanted into uPA/SCID mouse liver, lentivirally transduced primary human hepatocytes extensively repopulated their liver and maintained a differentiated and functional phenotype as assessed by the stable detection of human albumin and antitrypsin in the serum of the animals for months. In conclusion, the use of FLAP lentiviral vectors allows, in a short period of time, a high transduction efficiency of human functional and reimplantable hepatocytes. This work therefore opens new perspectives for the development of human clinical trials based on liver-directed ex vivo gene therapy.


Subject(s)
Genetic Therapy/methods , Genetic Vectors , Hepatocytes/cytology , Lentivirus/genetics , Animals , Cell Differentiation , Cell Division , Cells, Cultured , Hepatocytes/physiology , Hepatocytes/transplantation , Humans , Mice , Mice, SCID , Phenotype , Rats , Transduction, Genetic , Transgenes/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...