45 research outputs found
Immunization with L. sigmodontis Microfilariae Reduces Peripheral Microfilaraemia after Challenge Infection by Inhibition of Filarial Embryogenesis
Lymphatic filariasis is caused by parasitic filarial worms that are transmitted by mosquitoes, requiring uptake of larvae and distribution into the blood of the host. More than 120 million people are infected and about 30% of these individuals suffer from clinical symptoms. Reduction in transmission currently depends on mass drug administration, which has significantly reduced transmission rates over the past years. However, despite repetitive rounds of administration, transmission has not been eliminated completely from endemic areas. In some infected individuals the immune system can partially control the parasite, such that a proportion of infected individuals remain microfilaria-negative, despite the presence of adult worms. Therefore mechanisms must exist that are able to combat microfilaraemia. Identifying such mechanisms would help to design vaccines against disease transmitting microfilarial stages. Using the Litomosoides sigmodontis murine model of filariasis research we show a successful immunization against the blood-circulating larval stage that is responsible for arthropod-dependent transmission of the disease. Reduced microfilaraemia was associated with impairment of worm embryogenesis, with systemic and local microfilarial-specific host IgG and with IFN-γ secretion by host cells at the site of infection. These results raise hope for developing a microfilariae-based vaccine, being a pivotal step towards eradicating filariasis
Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials.
BACKGROUND: Treatment efficacy of physical agents in osteoarthritis of the knee (OAK) pain has been largely unknown, and this systematic review was aimed at assessing their short-term efficacies for pain relief. METHODS: Systematic review with meta-analysis of efficacy within 1-4 weeks and at follow up at 1-12 weeks after the end of treatment. RESULTS: 36 randomised placebo-controlled trials (RCTs) were identified with 2434 patients where 1391 patients received active treatment. 33 trials satisfied three or more out of five methodological criteria (Jadad scale). The patient sample had a mean age of 65.1 years and mean baseline pain of 62.9 mm on a 100 mm visual analogue scale (VAS). Within 4 weeks of the commencement of treatment manual acupuncture, static magnets and ultrasound therapies did not offer statistically significant short-term pain relief over placebo. Pulsed electromagnetic fields offered a small reduction in pain of 6.9 mm [95% CI: 2.2 to 11.6] (n = 487). Transcutaneous electrical nerve stimulation (TENS, including interferential currents), electro-acupuncture (EA) and low level laser therapy (LLLT) offered clinically relevant pain relieving effects of 18.8 mm [95% CI: 9.6 to 28.1] (n = 414), 21.9 mm [95% CI: 17.3 to 26.5] (n = 73) and 17.7 mm [95% CI: 8.1 to 27.3] (n = 343) on VAS respectively versus placebo control. In a subgroup analysis of trials with assumed optimal doses, short-term efficacy increased to 22.2 mm [95% CI: 18.1 to 26.3] for TENS, and 24.2 mm [95% CI: 17.3 to 31.3] for LLLT on VAS. Follow-up data up to 12 weeks were sparse, but positive effects seemed to persist for at least 4 weeks after the course of LLLT, EA and TENS treatment was stopped. CONCLUSION: TENS, EA and LLLT administered with optimal doses in an intensive 2-4 week treatment regimen, seem to offer clinically relevant short-term pain relief for OAK
Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias
BACKGROUND: The increased use of meta-analysis in systematic reviews of healthcare interventions has highlighted several types of bias that can arise during the completion of a randomised controlled trial. Study publication bias has been recognised as a potential threat to the validity of meta-analysis and can make the readily available evidence unreliable for decision making. Until recently, outcome reporting bias has received less attention. METHODOLOGY/PRINCIPAL FINDINGS: We review and summarise the evidence from a series of cohort studies that have assessed study publication bias and outcome reporting bias in randomised controlled trials. Sixteen studies were eligible of which only two followed the cohort all the way through from protocol approval to information regarding publication of outcomes. Eleven of the studies investigated study publication bias and five investigated outcome reporting bias. Three studies have found that statistically significant outcomes had a higher odds of being fully reported compared to non-significant outcomes (range of odds ratios: 2.2 to 4.7). In comparing trial publications to protocols, we found that 40-62% of studies had at least one primary outcome that was changed, introduced, or omitted. We decided not to undertake meta-analysis due to the differences between studies. CONCLUSIONS: Recent work provides direct empirical evidence for the existence of study publication bias and outcome reporting bias. There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported. Publications have been found to be inconsistent with their protocols. Researchers need to be aware of the problems of both types of bias and efforts should be concentrated on improving the reporting of trials
A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck
BACKGROUND: Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. METHODS: Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. RESULTS: Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). CONCLUSION: RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as single drug or combinations of 5-FU with one of the other drugs results in a large survival advantage irrespective the employed radiation schedule. If radiation therapy is used as single modality, hyperfractionation leads to a significant improvement of overall survival. Accelerated radiation therapy alone, especially when given as split course radiation schedule or extremely accelerated treatments with decreased total dose, does not increase overall survival
Barriers to and facilitators of interventions to counter publication bias: thematic analysis of scholarly articles and stakeholder interviews
An Atom-Probe Study of Retained Austenite in Ferritic Weld Metal High-resolution analytic techniques are used to quantitatively prove the distribution of boron and carbon in weld metal
ABSTRACT. The addition of titanium and boron to welding consumables results in an acicular ferrite microstructure that imparts excellent toughness to the weldment. An atom-probe field-ion microscopic study was carried out to study the influence of carbon and boron on the ya transformation in a ferritic weld metal and on the formation of acicular ferrite. It was observed that carbon diffuses into the remaining austenite when acicular ferrite is formed. The retained austenite can be enriched up to 7 at.-% with carbon, and it showed to be stable at a temperature of 90 K after removing some of the surrounding acicular ferrite grains. The atom-probe analysis did not indicate the presence of boron either at the y-oc interface or in the retained austenite grain
AN IMAGING ATOM PROBE STUDY
Two applications of an imaging atom probe are reported in which atomic resolution was achieved together with atomic identification. One concerns the presence of microcrystallites in a metallic glass Fe75-B15Si10, the other a comparison of the size of γ' precipitates in the alloy Ni55Cu36Al9 annealed for 3 h at 853 K measured both with a field ion and an electron microscope
AN IMAGING ATOM PROBE STUDY
Two applications of an imaging atom probe are reported in which atomic resolution was achieved together with atomic identification. One concerns the presence of microcrystallites in a metallic glass Fe75-B15Si10, the other a comparison of the size of γ' precipitates in the alloy Ni55Cu36Al9 annealed for 3 h at 853 K measured both with a field ion and an electron microscope