68 research outputs found

    Use of an online survey to detect reasons for low physical activity in COPD patients

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    We developed an online survey for COPD patients to investigate which reasons patients themselves list for being less active. In addition, this survey provides information on whether the internet proves to be a usable platform to administer surveys in COPD patients

    p-mTOR, p-ERK and PTEN Expression in Tumor Biopsies and Organoids as Predictive Biomarkers for Patients with HPV Negative Head and Neck Cancer

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    Background: Survival rates of head and neck squamous cell carcinoma (HNSCC) have only marginally improved in the last decades. Hence there is a need for predictive biomarkers for long-time survival that can help to guide treatment decisions and might lead to the development of new therapies. The phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR signaling pathway is the most frequently altered pathway in HNSCC, genes are often mutated, amplificated and overexpressed causing aberrant signaling affecting cell growth and differentiation. Numerous genetic alterations of upstream and downstream factors have currently been clarified. However, their predictive value has yet to be established. Therefore we assess the predictive value of p-mTOR, p-ERK and PTEN expression. Methods: Tissue microarrays (TMA’s) of HPV-negative patients with oropharyngeal (n = 48), hypopharyngeal (n = 16) or laryngeal (n = 13) SCC, treated with primary chemoradiation (cisplatin/carboplatin/cetuximab and radiotherapy), were histologically stained for p-mTOR, PTEN and p-ERK. Expression was correlated to overall survival (OS), disease free survival (DFS) and locoregional control (LRC). Also p-mTOR was histologically stained in a separate cohort of HNSCC organoids (n = 8) and correlated to mTOR-inhibitor everolimus response. Results: High p-mTOR expression correlated significantly with worse OS in multivariate analysis in the whole patient cohort [Hazar Ratio (HR) 1.06, 95%CI 1.01–1.11, p = 0.03] and in the cisplatin/carboplatin group with both worse OS (HR 1.09, 95%CI 1.02–1.16, p = 0.02) and DFS (HR 1.06, 95%CI 1.00–1.12, p = 0,04). p-ERK expression correlated significantly with DFS in univariate analysis in the whole patient cohort (HR 1.03, 95%CI 1.00–1.05, p = 0.04) and cisplatin/carboplatin group (HR 1.03, 95%CI 1.00–1.07, p = 0.04). PTEN-expression did not correlate with OS/DFS/LRC. Better organoid response to everolimus correlated significantly to higher p-mTOR expression (Rs = − 0.731, p = 0.04). Conclusions: High p-mTOR expression predicts and high p-ERK expression tends to predict worse treatment outcome in HPV negative HNSCC patients treated with chemoradiation, providing additional evidence that these markers are candidate prognostic biomarkers for survival in this patient population. Also this study shows that the use of HNSCC organoids for biomarker research has potential. The role of PTEN expression as prognostic biomarker remains unclear, as consistent evidence on its prognostic and predictive value is lacking.</p

    Molecular assessment of bacterial vaginosis by Lactobacillus abundance and species diversity

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    __Background:__ To date, women are most often diagnosed with bacterial vaginosis (BV) using microscopy based Nugent scoring or Amsel criteria. However, the accuracy is less than optimal. The aim of the present study was to confirm the identity of known BV-associated composition profiles and evaluate indicators for BV using three molecular methods. __Methods:__ Evaluation of indicators for BV was carried out by 16S rRNA amplicon sequencing of the V5-V7 region, a tailor-made 16S rRNA oligonucleotide-based microarray, and a PCR-based profiling technique termed IS-profiling, which is based on fragment variability of the 16S-23S rRNA intergenic spacer region. An inventory of vaginal bacterial species was obtained from 40 females attending a Dutch sexually transmitted infection outpatient clinic, of which 20 diagnosed with BV (Nugent score 7-10), and 20 BV negative (Nugent score 0-3). __Results:__ Analysis of the bacterial communities by 16S rRNA amplicon sequencing revealed two clusters in the BV negative women, dominated by either Lactobacillus iners or Lactobacillus crispatus and three distinct clusters in the BV positive women. In the former, there was a virtually complete, negative correlation between L. crispatus and L. iners. BV positive subjects showed cluster profiles that were relatively high in bacterial species diversity and dominated by anaerobic species, including Gardnerella vaginalis, an

    Patient-derived head and neck cancer organoids allow treatment stratification and serve as a tool for biomarker validation and identification

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    Background: Organoids are in vitro three-dimensional structures that can be grown from patient tissue. Head and neck cancer (HNC) is a collective term used for multiple tumor types including squamous cell carcinomas and salivary gland adenocarcinomas.Methods: Organoids were established from HNC patient tumor tissue and characterized using immunohistochemistry and DNA sequencing. Organoids were exposed to chemo- and radiotherapy and a panel of targeted agents. Organoid response was correlated with patient clinical response. CRISPR-Cas9-based gene editing of organoids was applied for biomarker validation.Findings: A HNC biobank consisting of 110 models, including 65 tumor models, was generated. Organoids retained DNA alterations found in HNC. Comparison of organoid and patient response to radiotherapy (primary [n = 6] and adjuvant [n = 15]) indicated potential for guiding treatment options in the adjuvant setting. In organoids, the radio-sensitizing potential of cisplatin and carboplatin could be validated. However, cetuximab conveyed radioprotection in most models. HNC-targeted treatments were tested on 31 models, indicating possible novel treatment options with the potential for treatment stratification in the future. Activating PIK3CA mutations did not predict alpelisib response in organoids. Protein arginine methyltransferase 5 (PRMT5) inhibitors were identified as a potential treatment option for cyclin-dependent kinase inhibitor 2A (CDKN2A) null HNC.Conclusions: Organoids hold potential as a diagnostic tool in personalized medicine for HNC. In vitro organoid response to radiotherapy (RT) showed a trend that mimics clinical response, indicating the predictive potential of patient-derived organoids. Moreover, organoids could be used for biomarker discovery and validation.</p

    Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: Prospective, multicentre cohort study

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    Study question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This prospective diagnostic study enrolled 298 adults (18-70 years) treated in 22 hospitals in the Netherlands over six years. CT angiography was performed within seven days of haemorrhage. If the result was negative, MRI/MRA was performed four to eight weeks later. DSA was performed when the CT angiography or MRI/MRA results were inconclusive or negative. The main outcome was a macrovascular cause, including arteriovenous malformation, aneurysm, dural arteriovenous fistula, and cavernoma. Three blinded neuroradiologists independently evaluated the images for macrovascular causes of haemorrhage. The reference standard was the best available evidence from all findings during one year's follow-up. Study answer and limitations A macrovascular cause was identified in 69 patients (23%). 291 patients (98%) underwent CT angiography; 214 with a negative result underwent additional MRI/MRA and 97 with a negative result for both CT angiography and MRI/MRA underwent DSA. Early CT angiography detected 51 macrovascular causes (yield 17%, 95% confidence interval 13% to 22%). CT angiography with MRI/MRA identified two additional macrovascular causes (18%, 14% to 23%) and these modalities combined with DSA another 15 (23%, 18% to 28%). This last extensive strategy failed to detect a cavernoma, which was identified on MRI during follow-up (reference strategy). The positive predictive value of CT angiography was 72% (60% to 82%), of additional MRI/MRA was 35% (14% to 62%), and of additional DSA was 100% (75% to 100%). None of the patients experienced complications with CT angiography or MRI/MRA; 0.6% of patients who underwent DSA experienced p

    Is spirometry feasible for institutionalised mentally handicapped?

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    Contains fulltext : 26142___.PDF (publisher's version ) (Open Access

    Use of an online survey to detect reasons for low physical activity in COPD patients

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    We developed an online survey for COPD patients to investigate which reasons patients themselves list for being less active. In addition, this survey provides information on whether the internet proves to be a usable platform to administer surveys in COPD patients

    Characterisation of SAMHD1's ancestral function

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    Deoxynucleoside triphosphates (dNTPs) are the building blocks of DNA. DNA synthesis requires dNTPs for replication and subsequent cell division. Therefore, nucleotide metabolism in cells is tightly regulated and failure of this regulation results in damage, toxicity and cell death. SAMHD1 is a highly conserved protein that degrades dNTPs and restricts HIV-1 through dNTP starvation. SAMHD1 is mutated in Aicardi-Goutières syndrome, a disease characterised by the chronic production of type I interferon. SAMHD1 is also involved in DNA repair and is mutated in cancer. SAMHD1 evolved before lentiviruses, suggesting that SAMHD1’s main function is not to restrict viruses. This project aimed to identify and characterise SAMHD1’s ancestral function. I show that addition of deoxynucleosides (dNs) to the culture medium resulted in the death of SAMHD1-deficient cells but not of WT cells. dNs were taken up by the cells and converted into dNTPs through the nucleotide salvage pathway. Cell death was most pronounced upon feeding with deoxyguanosine (dG) alone, suggesting that dGTP overload is particularly toxic to cells. In this model SAMHD1 tunes dNTP levels and protects cells against apoptosis triggered by dNTP overload or imbalances in the dNTP pools. Characterisation of this mechanism shed light on the mechanism of action of forodesine, an anti-cancer agent that inhibits purine nucleoside phosphorylase. Forodesine induces the accumulation of dGTP and subsequent cell death. Nevertheless, forodesine showed efficacy only in a minority of leukaemic patients, for unknown reasons. PBMCs from CLL patients with SAMHD1 loss-of-function mutations showed a significant reduction of CLL B-cells upon treatment with forodesine and dG compared with the control group. Therefore, I propose a model where SAMHD1 limits the efficacy of the PNP inhibitor forodesine which predict that patients with SAMHD1 mutations respond well to forodesine treatment. Forodesine could be used as a precision medicine. This new important role of SAMHD1 in dealing with dNTP overload and unbalances may be SAMHD1’s ancestral function. This mechanism can be exploited physiologically where dNTP accumulation is required for toxicity, such as forodesine treatment.</p
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