485 research outputs found

    Ultimate Failure Behaviour of Second-generation Sheeting Subjected to Combined Bending Moment and Concentrated Load

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    Second-generation sheeting is widely used for cladding and roof construction. At interior supports, it is subjected to combined bending moment and concentrated load. Unfortunately, design rules for this loading are complicated and do not provide insight in the sheeting\u27s failure behaviour. This means there is a need for a new, insight providing design rule. For first-generation sheeting, a similar problem did exist. The Technische Universiteit Eindhoven (TUE) carried out three research projects [Bakk92a,Vaes95a,Hofm00a] that provided insight in the first-generation sheeting behaviour and resulted in a new, insight providing design rule. The TUE now uses the strategy of these three research projects for a new project on second-generation sheeting [Kasp01a], with the final aim of a new design rule for second-generation sheeting. In this new project, experiments on commonly used (in the Netherlands) second-generation sheeting were carried out. Second-generation sheeting behaviour was compared with first-generation sheeting behaviour. For sheeting with only stiffeners in flange, load falls occur before ultimate load. Stiffeners in the web only result in load falls after the ultimate load. For an experiment with only stiffeners in the web, a finite element simulation was made. The simulation predicts the sheeting behaviour fairly well and indicates how a stiffener affects the sheeting behaviour

    cDNA Cloning of Biologically Active Chicken Interleukin-18

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    By searching a chicken EST database, we identified a cDNA clone that appeared to contain the entire open reading frame (ORF) of chicken interleukin-18 (ChIL-18). The encoded protein consists of 198 amino acids and exhibits approximately 30% sequence identity to IL-18 of humans and various others mammals. Sequence comparisons reveals a putative caspase-1 cleavage site at aspartic acid 29 of the primary translation product, indicating that mature ChIL-18 might consist of 169 amino acids. Bacterially expressed ChIL-18 in which the N-terminal 29 amino acids of the putative precursor molecule were replaced by a histidine tag induced the synthesis of interferon-γ (IFN-γ) in cultured primary chicken spleen cells, indicating that the recombinant protein is biologically active

    Research Programme to Improve the Utilization of Home-Grown forages in the Netherlands

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    In The Netherlands a research programme has been initiated by the Ministry of Agriculture, Nature Management and Fisheries to increase the proportion of high-quality home-grown forage in rations for dairy cows. This should result in a more sustainable dairy husbandry by improving the efficiency of utilization of nitrogen and phosphorus from home-grown forages (mainly grass and maize) on farm level. Research disciplines involved are plant breeding, forage harvesting and conservation and nutrition

    Factors influencing time to diagnosis and treatment among pediatric oncology patients in Kenya

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    Early diagnosis and start of treatment are fundamental goals in cancer care. This study determines the time lag and the factors that influence the time to diagnosis and start of treatment. Study participants were parents of childhood cancer patients diagnosed between August 2013 and July 2014 in a hospital in Kenya. Patient, physician, diagnosis, treatment, health care system, and total delay were explored using a questionnaire. Demographic and medical data were collected from the patients' medical records. Parents of 99 childhood cancer patients were interviewed (response rate: 80%). Median total delay was 102 (9–1021) days. Median patient delay (4 days) was significantly shorter than health care system delay (median 87 days; P < .001). Diagnosis delay (median 94 days) was significantly longer than treatment delay (median 6 days; P < .001). days. Lack of health insurance at diagnosis and use of alternative medicine before attending conventional health services were associated with a significantly longer patient delay (P = .041 and P = .017, respectively). The type of cancer had a significant effect on treatment delay (P = .020). The type of health facility attended affected only patient delay (P = .03). Gender, age at diagnosis, stage of disease, parents' education level or income, and distance from hospital did not have a significant effect on the length of any type of delay. Training on childhood cancer should be included in the curricula for medical training institutes. In-service workshops should be held for the health workers already working. Families must be obligated to get health insurance. Families should be encourage to attend conventional health facilities and informed on symptoms of cancer through mass media

    Surgical morbidity and mortality of pediatric brain tumors: a single center audit

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    OBJECTIVES: The primary aim of this study is to perform an internal quality control of pediatric brain tumor surgery in the neurosurgical department of the VU University Medical Center Amsterdam (The Netherlands). Secondly, this study aims to contribute to the accumulating data concerning outcome in pediatric neurosurgery, in order to establish institutional practice benchmarks. METHODS: We report the surgical mortality and morbidity of 121 patients (0–18 years) surgically treated for a brain tumor from January 1999 to August 2007. Patients, in whom only a brain tumor biopsy was performed, were excluded. RESULTS: Mean age at first surgery was 8.2 years. Of the 121 patients, 14 had a second surgery, and two underwent a third surgery (for a total of 137 operations). Of all 121 primary surgeries, 66% were total resections, 26% subtotal resections, and 8% partial resections. The overall surgical morbidity rate in this study was 69% after first surgery, 50% after second surgery, and one out of two after third surgery. CONCLUSION: These overall morbidity rates are comparable to other published mixed case series. The surgical mortality rate was 0.8%; this is comparable to the lowest rates reported for high-volume neurosurgical centers. We encourage other neurosurgical centers to collect, analyze, and publish their data. These data can then serve as a basis for comparison with other pediatric neurosurgical centers and will eventually lead to an improvement of pediatric neurosurgical practice and patient care

    Cell proliferation is related to in vitro drug resistance in childhood acute leukaemia

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    0.05) with sensitivity to antimetabolites (cytarabine, mercaptopurine, thioguanine), L-asparaginase, teniposide, and vincristine. Similar results were found within subgroups of initial ALL (nonhyperdiploid and common/precursor-B-lineage ALL). In relapsed ALL and AML such correlations were not found. In conclusion, cell proliferation differs between leukaemia subgroups and increased proliferation is associated with increased in vitro sensitivity to several anticancer agents in initial ALL

    In vitro drug sensitivity of normal peripheral blood lymphocytes and childhood leukaemic cells from bone marrow and peripheral blood.

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    In vitro drug sensitivity of leukaemic cells might be influenced by the contamination of such a sample with non-malignant cells and the sample source. To study this, sensitivity of normal peripheral blood (PB) lymphocytes to a number of cytostatic drugs was assessed with the MTT assay. We compared this sensitivity with the drug sensitivity of leukaemic cells of 38 children with acute lymphoblastic leukaemia. We also studied a possible differential sensitivity of leukaemic cells from bone marrow (BM) and PB. The following drugs were used: Prednisolone, dexamethasone, 6-mercaptopurine, 6-thioguanine, cytosine arabinoside, vincristine, vindesine, daunorubicin, doxorubicin, mafosfamide (Maf), 4-hydroperoxy-ifosfamide, teniposide, mitoxantrone, L-asparaginase, methotrexate and mustine. Normal PB lymphocytes were significantly more resistant to all drugs tested, except to Maf. Leukaemic BM and PB cells from 38 patients (unpaired samples) showed no significant differences in sensitivity to any of the drugs. Moreover, in 11 of 12 children with acute leukaemia of whom we investigated simultaneously obtained BM and PB (paired samples), their leukaemic BM and PB cells showed comparable drug sensitivity profiles. In one patient the BM cells were more sensitive to most drugs than those from the PB, but the actual differences in sensitivity were small. We conclude that the contamination of a leukaemic sample with normal PB lymphocytes will influence the results of the MTT assay. The source of the leukaemic sample, BM or PB, does not significantly influence the assay results

    Mononuclear cells contaminating acute lymphoblastic leukaemic samples tested for cellular drug resistance using the methyl-thiazol-tetrazolium assay.

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    The methyl-thiazol-tetrazolium (MTT) assay is a drug resistance assay which cannot discriminate between malignant and non-malignant cells. We previously reported that samples with > or = 80% leukaemic cells at the start of culture give similar results in the MTT assay and the differential staining cytotoxicity assay, in which a discrimination between malignant and non-malignant cells can be made. However, the percentage of leukaemic cells may change during culture, which might affect the results of the MTT assay. We studied 106 untreated childhood acute lymphoblastic leukemia (ALL) samples with > or = 80% leukaemic cells at the start of culture. This percentage decreased below 80% in 28%, and below 70% in 13%, of the samples after 4 days of culture. A decrease below 70% occurred more often in case of 80-89% leukaemic cells (9/29) than in case of > or = 90% leukaemic cells at the start of culture (5/77, P = 0.0009). Samples with < 70% leukaemic cells after culture were significantly more resistant to 6 out of 13 drugs, and showed a trend towards being more resistant to two more drugs, than samples with > or = 80% leukaemic cells. No such differences were seen between samples with 70-79% and samples with > or = 80% leukaemic cells after culture. We next studied in another 30 ALL samples whether contaminating mononuclear cells could be removed by using immunoamagnetic beads. Using a beads to target cell ratio of 10:1, the percentage of leukaemic cells increased from mean 72% (s.d. 9.3%) to mean 87% (s.d. 6.7%), with an absolute increase of 2-35%. The recovery of leukaemic cells was mean 82.1% (range 56-100%, s.d. 14.0%). The procedure itself did not influence the results of the MTT assay in three samples containing only leukaemic cells. We conclude that it is important to determine the percentage of leukaemic cells at the start and at the end of the MTT assay and similar drug resistance assays. Contaminating mononuclear cells can be successfully removed from ALL samples using immunomagnetic beads. This approach may increase the number of leukaemic samples which can be evaluated for cellular drug resistance with the MTT assay or a similar cell culture drug resistance assay

    Insomnia Symptoms and Daytime Fatigue Co-Occurrence in Adolescent and Young Adult Childhood Cancer Patients in Follow-Up after Treatment:Prevalence and Associated Risk Factors

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    Simple Summary Insomnia symptoms and daytime fatigue significantly impact physical and psychosocial health. While these are common symptoms in pediatric oncology, relationships between these symptoms remain unclear. This study evaluated the prevalence of insomnia only, daytime fatigue only, the co-occurrence of insomnia and daytime fatigue symptoms, and associated risk factors in adolescent/young adult childhood cancer patients in follow-up after treatment. Results showed that around forty percent had insomnia and daytime fatigue symptoms, which often co-occurred. Risk factors that emerged were: female sex and co-morbidities (all), shorter time after treatment and bedtime gaming (insomnia only), young adulthood (insomnia-fatigue and fatigue only), needing someone else to fall asleep and inconsistent wake times (both insomnia groups), and lower educational level and consistent bedtimes (insomnia-fatigue). Overall, insomnia symptoms and daytime fatigue were common and often co-occurred in this patient population. While current fatigue guidelines do not include insomnia symptoms, healthcare providers should inquire about insomnia as this potentially provides additional options for treatment and prevention. Insomnia symptoms and daytime fatigue commonly occur in pediatric oncology, which significantly impact physical and psychosocial health. This study evaluated the prevalence of insomnia only, daytime fatigue only, the co-occurrence of insomnia-daytime fatigue symptoms, and associated risk factors. Childhood cancer patients (n = 565, 12-26 years old, >= 6 months after treatment) participated in a national, cross-sectional questionnaire study, measuring insomnia symptoms (ISI; Insomnia Severity Index) and daytime fatigue (single item). Prevalence rates of insomnia and/or daytime fatigue subgroups and ISI severity ranges were calculated. Multinomial regression models were applied to assess risk factors. Most patients reported no insomnia symptoms or daytime fatigue (61.8%). In the 38.2% of patients who had symptoms, 48.1% reported insomnia and daytime fatigue, 34.7% insomnia only, and 17.1% daytime fatigue only. Insomnia scores were higher in patients with insomnia-daytime fatigue compared to insomnia only (p < 0.001). Risk factors that emerged were: female sex and co-morbidities (all), shorter time after treatment and bedtime gaming (insomnia only), young adulthood (insomnia-fatigue/fatigue only), needing someone else to fall asleep and inconsistent wake times (both insomnia groups), lower educational level and consistent bedtimes (insomnia-fatigue). Insomnia symptoms and daytime fatigue are common and often co-occur. While current fatigue guidelines do not include insomnia symptoms, healthcare providers should inquire about insomnia as this potentially provides additional options for treatment and prevention

    Infections with Avian Pathogenic and Fecal Escherichia coli Strains Display Similar Lung Histopathology and Macrophage Apoptosis

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    The purpose of this study was to compare histopathological changes in the lungs of chickens infected with avian pathogenic (APEC) and avian fecal (Afecal) Escherichia coli strains, and to analyze how the interaction of the bacteria with avian macrophages relates to the outcome of the infection. Chickens were infected intratracheally with three APEC strains, MT78, IMT5155, and UEL17, and one non-pathogenic Afecal strain, IMT5104. The pathogenicity of the strains was assessed by isolating bacteria from lungs, kidneys, and spleens at 24 h post-infection (p.i.). Lungs were examined for histopathological changes at 12, 18, and 24 h p.i. Serial lung sections were stained with hematoxylin and eosin (HE), terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) for detection of apoptotic cells, and an anti-O2 antibody for detection of MT78 and IMT5155. UEL17 and IMT5104 did not cause systemic infections and the extents of lung colonization were two orders of magnitude lower than for the septicemic strains MT78 and IMT5155, yet all four strains caused the same extent of inflammation in the lungs. The inflammation was localized; there were some congested areas next to unaffected areas. Only the inflamed regions became labeled with anti-O2 antibody. TUNEL labeling revealed the presence of apoptotic cells at 12 h p.i in the inflamed regions only, and before any necrotic foci could be seen. The TUNEL-positive cells were very likely dying heterophils, as evidenced by the purulent inflammation. Some of the dying cells observed in avian lungs in situ may also be macrophages, since all four avian E. coli induced caspase 3/7 activation in monolayers of HD11 avian macrophages. In summary, both pathogenic and non-pathogenic fecal strains of avian E. coli produce focal infections in the avian lung, and these are accompanied by inflammation and cell death in the infected areas
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