49 research outputs found

    Alphavirus replicon particles containing the gene for HER2/neu inhibit breast cancer growth and tumorigenesis

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    INTRODUCTION: Overexpression of the HER2/neu gene in breast cancer is associated with an increased incidence of metastatic disease and with a poor prognosis. Although passive immunotherapy with the humanized monoclonal antibody trastuzumab (Herceptin) has shown some effect, a vaccine capable of inducing T-cell and humoral immunity could be more effective. METHODS: Virus-like replicon particles (VRP) of Venezuelan equine encephalitis virus containing the gene for HER2/neu (VRP-neu) were tested by an active immunotherapeutic approach in tumor prevention models and in a metastasis prevention model. RESULTS: VRP-neu prevented or significantly inhibited the growth of HER2/neu-expressing murine breast cancer cells injected either into mammary tissue or intravenously. Vaccination with VRP-neu completely prevented tumor formation in and death of MMTV-c-neu transgenic mice, and resulted in high levels of neu-specific CD8(+ )T lymphocytes and serum IgG. CONCLUSION: On the basis of these findings, clinical testing of this vaccine in patients with HER2/neu(+ )breast cancer is warranted

    Temporary Closure of the Open Abdomen: A Systematic Review on Delayed Primary Fascial Closure in Patients with an Open Abdomen

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    Background This study was designed to systematically review the literature to assess which temporary abdominal closure (TAC) technique is associated with the highest delayed primary fascial closure (FC) rate. In some cases of abdominal trauma or infection, edema or packing precludes fascial closure after laparotomy. This "open abdomen'' must then be temporarily closed. However, the FC rate varies between techniques. Methods The Cochrane Register of Controlled Trials, MEDLINE, and EMBASE databases were searched until December 2007. References were checked for additional studies. Search criteria included (synonyms of) "open abdomen,'' "fascial closure,'' "vacuum,'' "reapproximation,'' and "ventral hernia.'' Open abdomen was defined as "the inability to close the abdominal fascia after laparotomy.'' Two reviewers independently extracted data from original articles by using a predefined checklist. Results The search identified 154 abstracts of which 96 were considered relevant. No comparative studies were identified. After reading them, 51 articles, including 57 case series were included. The techniques described were vacuum-assisted closure (VAC; 8 series), vacuum pack (15 series), artificial burr (4 series), Mesh/sheet (16 series), zipper (7 series), silo (3 series), skin closure (2 series), dynamic retention sutures (DRS), and loose packing (1 series each). The highest FC rates were seen in the artificial burr (90%), DRS (85%), and VAC (60%). The lowest mortality rates were seen in the artificial burr (17%), VAC (18%), and DRS (23%). Conclusions These results suggest that the artificial burr and the VAC are associated with the highest FC rates and the lowest mortality rate

    Doxorubicin and paclitaxel enhance the antitumor efficacy of vaccines directed against HER 2/neu in a murine mammary carcinoma model

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    INTRODUCTION: The purpose of the present study was to determine whether cytotoxic chemotherapeutic agents administered prior to immunotherapy with gene vaccines could augment the efficacy of the vaccines. METHODS: Mice were injected in the mammary fat pad with an aggressive breast tumor cell line that expresses HER2/neu. The mice were treated 3 days later with a noncurative dose of either doxorubicin or paclitaxel, and the following day with a gene vaccine to HER2/neu. Two more doses of vaccine were given 14 days apart. Two types of gene vaccines were tested: a plasmid vaccine encoding a self-replicating RNA (replicon) of Sindbis virus (SINCP), in which the viral structural proteins were replaced by the gene for neu; and a viral replicon particle derived from an attenuated strain of Venezuelan equine encephalitis virus, containing a replicon RNA in which the Venezuelan equine encephalitis virus structural proteins were replaced by the gene for neu. RESULTS: Neither vaccination alone nor chemotherapy alone significantly reduced the growth of the mammary carcinoma. In contrast, chemotherapy followed by vaccination reduced tumor growth by a small, but significant amount. Antigen-specific CD8(+ )T lymphocytes were induced by the combined treatment, indicating that the control of tumor growth was most probably due to an immunological mechanism. The results demonstrated that doxorubicin and paclitaxel, commonly used chemotherapeutic agents for the treatment of breast cancer, when used at immunomodulating doses augmented the antitumor efficacy of gene vaccines directed against HER2/neu. CONCLUSIONS: The combination of chemotherapeutic agents plus vaccine immunotherapy may induce a tumor-specific immune response that could be beneficial for the adjuvant treatment of patients with minimal residual disease. The regimen warrants further evaluation in a clinical setting

    Two Chromatin Remodeling Activities Cooperate during Activation of Hormone Responsive Promoters

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    Steroid hormones regulate gene expression by interaction of their receptors with hormone responsive elements (HREs) and recruitment of kinases, chromatin remodeling complexes, and coregulators to their target promoters. Here we show that in breast cancer cells the BAF, but not the closely related PBAF complex, is required for progesterone induction of several target genes including MMTV, where it catalyzes localized displacement of histones H2A and H2B and subsequent NF1 binding. PCAF is also needed for induction of progesterone target genes and acetylates histone H3 at K14, an epigenetic mark that interacts with the BAF subunits by anchoring the complex to chromatin. In the absence of PCAF, full loading of target promoters with hormone receptors and BAF is precluded, and induction is compromised. Thus, activation of hormone-responsive promoters requires cooperation of at least two chromatin remodeling activities, BAF and PCAF

    Multi-level analysis of electronic health record adoption by health care professionals: A study protocol

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    <p>Abstract</p> <p>Background</p> <p>The electronic health record (EHR) is an important application of information and communication technologies to the healthcare sector. EHR implementation is expected to produce benefits for patients, professionals, organisations, and the population as a whole. These benefits cannot be achieved without the adoption of EHR by healthcare professionals. Nevertheless, the influence of individual and organisational factors in determining EHR adoption is still unclear. This study aims to assess the unique contribution of individual and organisational factors on EHR adoption in healthcare settings, as well as possible interrelations between these factors.</p> <p>Methods</p> <p>A prospective study will be conducted. A stratified random sampling method will be used to select 50 healthcare organisations in the Quebec City Health Region (Canada). At the individual level, a sample of 15 to 30 health professionals will be chosen within each organisation depending on its size. A semi-structured questionnaire will be administered to two key informants in each organisation to collect organisational data. A composite adoption score of EHR adoption will be developed based on a Delphi process and will be used as the outcome variable. Twelve to eighteen months after the first contact, depending on the pace of EHR implementation, key informants and clinicians will be contacted once again to monitor the evolution of EHR adoption. A multilevel regression model will be applied to identify the organisational and individual determinants of EHR adoption in clinical settings. Alternative analytical models would be applied if necessary.</p> <p>Results</p> <p>The study will assess the contribution of organisational and individual factors, as well as their interactions, to the implementation of EHR in clinical settings.</p> <p>Conclusions</p> <p>These results will be very relevant for decision makers and managers who are facing the challenge of implementing EHR in the healthcare system. In addition, this research constitutes a major contribution to the field of knowledge transfer and implementation science.</p
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