13 research outputs found

    Role of tumor-derived fibroblasts in the growth of primary cultures of human breast-cancer cells: Effects of epidermal growth factor and the somatostatin analogue octreotide

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    In the present study we have investigated the role of human breast-cancer-derived fibroblasts in the proliferation of primary cultures of epithelial cells derived from the same tumor. For this purpose, a co-culture system, using Transwell tissue-culture inserts with microporous membranes was employed. Fibroblasts and epithelial cells were enriched according to differences in their density on Percoll density gradients. The co-culture system was first established using MCF-7 breast cancer cells and a human fibroblast line (HF cells). Insulin, 17β-estradiol, EGF and HF cells all significantly stimulated the growth of MCF-7 breast cancer cells. The stimulatory effects of insulin, E2 and EGF were additive to the stimulatory effect of HF cells. These data suggest that (unique) factor(s), other than the above-mentioned growth-promoting compounds, are responsible for the growth-promoting effects of fibroblasts. In half of the human breast cancers investigated, tumor-derived fibroblasts stimulated tumor-derived epithelial cell proliferation. EGF significantly stimulated epithelial cell proliferation in 4 out of 6 cultures. The stimulatory effects of fibroblasts and EGF were additive or synergistic, and were observed in the additional presence of FCS, again suggesting production of unique factor(s) by the fibroblasts, in one culture the fibroblasts significantly inhibited epithelial tumor-cell proliferation. Conversely, the epithelial cells significantly stimulated proliferation of fibroblasts in 3 out of 3 cultures. The somatostatin analogue octreotide significantly inhibited epithelial cell proliferation by 46% in one tumor-cell culture in the absence, but not in the presence, of fibroblasts. In one culture, octreotide significantly inhibited the proliferation of fibroblasts co-cultured with epithelial cells

    Timing of Group B Streptococcus Screening in Pregnancy: A Systematic Review

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    Background: Group B streptococcus (GBS) is an important cause of neonatal sepsis. Guidelines advise to collect cultures at 35-37 weeks' gestation and to administer intrapartum antibiotic prophylaxis in case of GBS-positive cultures, as well as in all preterm deliveries. Improved effectiveness of antenatal cultures might help to further decrease GBS early-onset disease. Objective: To determine the best timing of antenatal cultures, which may help establish optimal prevention of perinatal GBS infection in both term and preterm neonates. Methods: PubMed and EMBASE databases were searched for relevant articles published from 1966 to February 2009. Nine articles were included. Information about study features and predictive values of antenatal cultures were abstracted. Results: Positive predictive values for antenatal GBS cultures ranged from 43 to 100% (mean 69%) and negative predictive values from 80 to 100% (mean 94%). GBS cultures collected in late pregnancy had high positive predictive values for colonization during delivery. The negative predictive value was high and relatively constant regardless of GA. Conclusions: This systematic review confirms recommendations to screen pregnant women for colonization of GBS at 35-37 weeks' gestation, but one should be aware of the limitations of screening, with 6% of GBS carriers remaining undetected in antenatal cultures. Copyright (C) 2009 S. Karger AG, BaselClinical epidemiolog

    Development and technical validation of a smartphone-based pediatric cough detection algorithm

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    IntroductionCoughing is a common symptom in pediatric lung disease and cough frequency has been shown to be correlated to disease activity in several conditions. Automated cough detection could provide a noninvasive digital biomarker for pediatric clinical trials or care. The aim of this study was to develop a smartphone-based algorithm that objectively and automatically counts cough sounds of children.MethodsThe training set was composed of 3228 pediatric cough sounds and 480,780 noncough sounds from various publicly available sources and continuous sound recordings of 7 patients admitted due to respiratory disease. A Gradient Boost Classifier was fitted on the training data, which was subsequently validated on recordings from 14 additional patients aged 0–14 admitted to the pediatric ward due to respiratory disease. The robustness of the algorithm was investigated by repeatedly classifying a recording with the smartphone-based algorithm during various conditions.ResultsThe final algorithm obtained an accuracy of 99.7%, sensitivity of 47.6%, specificity of 99.96%, positive predictive value of 82.2% and negative predictive value 99.8% in the validation dataset. The correlation coefficient between manual- and automated cough counts in the validation dataset was 0.97 (p ConclusionThis novel smartphone-based pediatric cough detection application can be used for longitudinal follow-up in clinical care or as digital endpoint in clinical trials.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

    A virtual asthma clinic for children: fewer routine outpatient visits, same asthma control

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    Contains fulltext : 177833.pdf (publisher's version ) (Closed access)eHealth is an appealing medium to improve healthcare and its value (in addition to standard care) has been assessed in previous studies. We aimed to assess whether an eHealth intervention could improve asthma control while reducing 50% of routine outpatient visits.In a multicentre, randomised controlled trial with a 16-month follow-up, asthmatic children (6-16 years) treated in eight Dutch hospitals were randomised to usual care (4-monthly outpatient visits) and online care using a virtual asthma clinic (VAC) (8-monthly outpatient visits with monthly web-based monitoring). Outcome measures were the number of symptom-free days in the last 4 weeks of the study, asthma control, forced expiratory volume in 1 s, exhaled nitric oxide fraction, asthma exacerbations, unscheduled outpatient visits, hospital admissions, daily dose of inhaled corticosteroids and courses of systemic corticosteroids.We included 210 children. After follow-up, symptom-free days differed statistically between the usual care and VAC groups (difference of 1.23 days, 95% CI 0.42-2.04; p=0.003) in favour of the VAC. In terms of asthma control, the Childhood Asthma Control Test improved more in the VAC group (difference of 1.17 points, 95% CI 0.09-2.25; p=0.03). No differences were found for other outcome measures.Routine outpatient visits can partly be replaced by monitoring asthmatic children via eHealth
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