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1.
Until 1984, cold harpoons, i.e. harpoons with no detonating device, were used to hunt minke whales in Norway. To investigate the effectiveness of such harpoons and compare them with alternatives, data on kills using cold harpoons were collected as part of a project dealing with alternative killing techniques for whales. Data on 353 whale kills were collected in 1981–83. The criteria used to determine the time of death were cessation of flipper movement, that the mandible relaxed, or that the whale hung immobile from the harpoon line. These criteria do not take into account any movements caused by spinal reflexes. About 17% of the animals died instantaneously (≤10 s). The median survival time was 570 s. Animals died most rapidly if hit in the brain, heart or major blood vessels. If only the lungs were injured, minke whales died less rapidly than terrestrial mammals. For whales that did not die immediately, shooting range, animal size and the angle of the shot all influenced the time to death. The efficiency of cold harpoons could be improved, but their use was no longer considered acceptable, and they were replaced by harpoons with penthrite grenades in 1984. 相似文献
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Adrian Gheorghe Tracy E. Roberts Jonathan C. Ives Benjamin R. Fletcher Melanie Calvert 《PloS one》2013,8(2)
Background
The rationale for centre selection in randomised controlled trials (RCTs) is often unclear but may have important implications for the generalisability of trial results. The aims of this study were to evaluate the factors which currently influence centre selection in RCTs and consider how generalisability considerations inform current and optimal practice.Methods and Findings
Mixed methods approach consisting of a systematic review and meta-summary of centre selection criteria reported in RCT protocols funded by the UK National Institute of Health Research (NIHR) initiated between January 2005-January 2012; and an online survey on the topic of current and optimal centre selection, distributed to professionals in the 48 UK Clinical Trials Units and 10 NIHR Research Design Services. The survey design was informed by the systematic review and by two focus groups conducted with trialists at the Birmingham Centre for Clinical Trials. 129 trial protocols were included in the systematic review, with a total target sample size in excess of 317,000 participants. The meta-summary identified 53 unique centre selection criteria. 78 protocols (60%) provided at least one criterion for centre selection, but only 31 (24%) protocols explicitly acknowledged generalisability. This is consistent with the survey findings (n = 70), where less than a third of participants reported generalisability as a key driver of centre selection in current practice. This contrasts with trialists’ views on optimal practice, where generalisability in terms of clinical practice, population characteristics and economic results were prime considerations for 60% (n = 42), 57% (n = 40) and 46% (n = 32) of respondents, respectively.Conclusions
Centres are rarely enrolled in RCTs with an explicit view to external validity, although trialists acknowledge that incorporating generalisability in centre selection should ideally be more prominent. There is a need to operationalize ‘generalisability’ and incorporate it at the design stage of RCTs so that results are readily transferable to ‘real world’ practice. 相似文献3.
Isao Oze Katsuyuki Hotta Katsuyuki Kiura Nobuaki Ochi Nagio Takigawa Yoshiro Fujiwara Masahiro Tabata Mitsune Tanimoto 《PloS one》2009,4(11)
Background
Few studies have formally assessed whether treatment outcomes have improved substantially over the years for patients with extensive disease small-cell lung cancer (ED-SCLC) enrolled in phase III trials. The objective of the current investigation was to determine the time trends in outcomes for the patients in those trials.Methods and Findings
We searched for trials that were reported between January 1981 and August 2008. Phase III randomized controlled trials were eligible if they compared first-line, systemic chemotherapy for ED-SCLC. Data were evaluated by using a linear regression analysis. Results: In total, 52 trials were identified that had been initiated between 1980 and 2006; these studies involved 10,262 patients with 110 chemotherapy arms. The number of randomized patients and the proportion of patients with good performance status (PS) increased over time. Cisplatin-based regimens, especially cisplatin and etoposide (PE) regimen, have increasingly been studied, whereas cyclophosphamide, doxorubicin, and vincristine–based regimens have been less investigated. Multiple regression analysis showed no significant improvement in survival over the years. Additionally, the use of a PE regimen did not affect survival, whereas the proportion of patients with good PS and the trial design of assigning prophylactic cranial irradiation were significantly associated with favorable outcome.Conclusions and Significance
The survival of patients with ED-SCLC enrolled in phase III trials did not improve significantly over the years, suggesting the need for further development of novel targets, newer agents, and comprehensive patient care. 相似文献4.
The concept that a specific alteration in an individual’s DNA can result in disease is central to our notion of molecular medicine. The molecular basis of more than 3,500 Mendelian disorders has now been identified. In contrast, the identification of genes for common disease has been much more challenging. We discuss historical and contemporary approaches to disease gene identification, focusing on novel opportunities such as the use of population extremes and the identification of rare variants. While our ability to sequence DNA has advanced dramatically, assigning function to a given sequence change remains a major challenge, highlighting the need for both bioinformatics and functional approaches to appropriately interpret these data. We review progress in mapping and identifying human disease genes and discuss future challenges and opportunities for the field. 相似文献
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The MOXD2 gene encodes a membrane-bound monooxygenase similar to dopamine-β-hydroxylase, and has been proposed to be associated with olfaction. In this study, we analyzed MOXD2 genes from 64 mammalian species, and identified loss-of-function mutations in apes (humans, Sumatran and Bornean orangutans, and five gibbon species from the four major gibbon genera), toothed whales (killer whales, bottlenose dolphins, finless porpoises, baijis, and sperm whales), and baleen whales (minke whales and fin whales). We also identified a shared 13-nt deletion in the last exon of Old World cercopithecine monkeys that results in conversion of a membrane-bound protein to a soluble form. We hypothesize that the frequent inactivation and alteration of MOXD2 genes in catarrhines and whales may be associated with the evolution of olfaction in these clades. 相似文献
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Ryutaro Ohtsuka 《American journal of physical anthropology》1989,80(1):31-39
From the individual-based records of hunting practice for 1,633 hr in total and from the hunters' visual acuity and grip strength observed among the Gidra Papuans in lowland Papua New Guinea, this paper aims to analyze the relationship between the hunting activity and aging. The sensorimotor functions determine the range of age in which the individuals act as active or productive hunters: determined to be from the late teen-age years to about 45 years among the present subjects. In this age range, hunting efficiency increases with age. In terms of weight of animals killed per hunting time, the efficiency of the elder married (aged about 35 to 45 years) was almost four times higher than that of the unmarried (16–17 to late 20s). This aging effect is judged to depend on behavioral abilities that increase in accordance with experience and cumulative knowledge. Simultaneously, the comparison of individual hunters' records in 1971–72 and in 1981 reveals that hunting efficiency is associated with the individualities of the hunters. 相似文献
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Elisabeth Eckersberger Julia Finkelstein Helen Sadri Markus Margreiter Samir S Taneja Herbert Lepor Bob Djavan 《Reviews in urology》2009,11(3):127-133
The advent of prostate-specific antigen (PSA) testing in the early 1980s revolutionized the diagnosis of prostate cancer. As a result of PSA testing, there has been a surge in the number of prostate cancer diagnoses. This review examines the results of 2 recent landmark trials that studied the effect of screening on prostate cancer mortality: the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US-based Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.Key words: PSA screening, European Randomized Study of Screening for Prostate Cancer (ERSPC), Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening TrialProstate cancer poses a significant problem for men’s health; it has become the most common malignancy and the second most common cause of cancer death in American men. It is estimated that 1 in 6 men will be diagnosed with prostate cancer at some time in their lives, and more than 30,000 men died of the disease in 2002.1 The advent of prostate-specific antigen (PSA) testing in the early 1980s revolutionized the diagnosis of prostate cancer, and, as a result, there has been a surge in the number of prostate cancer diagnoses.Similar to other common malignancies, such as breast and cervical cancer, population screening with this effective tumor marker appears enticing, and the American health care model has advocated PSA screening since the early 1990s. This review examines the results of 2 recent landmark trials: the European Randomized Study of Screening for Prostate Cancer (ERSPC)1 and the US-based Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.2 The results of these trials have contributed significantly to our understanding of the effects and efficacy of prostate cancer screening, and its difficulties. Both trials examined mortality as the endpoint, and both found little effect on mortality from screening. 相似文献
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Kerry Dwan Douglas G. Altman Mike Clarke Carrol Gamble Julian P. T. Higgins Jonathan A. C. Sterne Paula R. Williamson Jamie J. Kirkham 《PLoS medicine》2014,11(6)
Background
Most publications about selective reporting in clinical trials have focussed on outcomes. However, selective reporting of analyses for a given outcome may also affect the validity of findings. If analyses are selected on the basis of the results, reporting bias may occur. The aims of this study were to review and summarise the evidence from empirical cohort studies that assessed discrepant or selective reporting of analyses in randomised controlled trials (RCTs).Methods and Findings
A systematic review was conducted and included cohort studies that assessed any aspect of the reporting of analyses of RCTs by comparing different trial documents, e.g., protocol compared to trial report, or different sections within a trial publication. The Cochrane Methodology Register, Medline (Ovid), PsycInfo (Ovid), and PubMed were searched on 5 February 2014. Two authors independently selected studies, performed data extraction, and assessed the methodological quality of the eligible studies. Twenty-two studies (containing 3,140 RCTs) published between 2000 and 2013 were included. Twenty-two studies reported on discrepancies between information given in different sources. Discrepancies were found in statistical analyses (eight studies), composite outcomes (one study), the handling of missing data (three studies), unadjusted versus adjusted analyses (three studies), handling of continuous data (three studies), and subgroup analyses (12 studies). Discrepancy rates varied, ranging from 7% (3/42) to 88% (7/8) in statistical analyses, 46% (36/79) to 82% (23/28) in adjusted versus unadjusted analyses, and 61% (11/18) to 100% (25/25) in subgroup analyses. This review is limited in that none of the included studies investigated the evidence for bias resulting from selective reporting of analyses. It was not possible to combine studies to provide overall summary estimates, and so the results of studies are discussed narratively.Conclusions
Discrepancies in analyses between publications and other study documentation were common, but reasons for these discrepancies were not discussed in the trial reports. To ensure transparency, protocols and statistical analysis plans need to be published, and investigators should adhere to these or explain discrepancies. Please see later in the article for the Editors'' Summary 相似文献10.
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Background
In 2009 two RCTs were publicated to question the efficacy of vertebroplasty comparing with sham treatment (ST) in the New England Journal of Medicine (NEJM), which provoked an academic debate on the efficacy of PVA. The purposes of our study were to compare clinical differences in pain relief, spinal functional outcomes, and overall quality of life between PVA and CT for painful osteoporotic VCFs.Methods
We searched PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and Web of Knowledge from January 1980 to June 2013 with Medical Subject Headings terms and keywords. Risk of bias in the included studies was assessed in accordance with the Cochrane risk of bias tool. In this Meta-analysis dichotomous and continuous variables were calculated using the risk ratio (RR) and standardized mean difference (SMD), respectively.Results
Eight studies involving 987 patients met the criteria for inclusion. The VAS SMD was favoring the experimental group significantly (p < 0.001). Subgroup analysis suggested that the patients performed PVA with mean fracture age less than 3 months would got pain relief earlier and more durable than the control group (P <0.05). The SMD of spinal function assessed with RDQ and Oswestry LBP data was in favor of the experimental groups. QOL outcome improvement was demonstrated statistically significant at early, middle and late-term follow-up for PVA than the control group (P <0.05).Conclusions
In conclusion, this meta-analysis, which evaluated PVA for osteoporotic VCFs, demonstrated significant improvement regarding VAS, spinal function and QOL outcomes. The optimal fracture age was less than 12 weeks. 相似文献12.
Statistics in Biosciences - Discontinuation of assigned therapy in longitudinal clinical trials is often inevitable due to various reasons such as intolerability or lack of efficacy. When the... 相似文献
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Background
The extent of the benefit of bevacizumab combined with chemotherapy in the treatment of advanced non-small-cell lung cancer (NSCLC) is still unclear. We performed this meta-analysis to compare the efficacy of bevacizumab with other commonly used targeted drugs for different patients with advanced NSCLC.Methods
We searched PubMed, Cochrane Library, EMBASE and abstracts from the proceedings of the American Society of Clinical Oncology (ASCO), and identified 30 randomized controlled clinical trials published within 1999 to 2011 for meta-analysis.Results
The outcomes of treatment efficacy included response rate, PFS and OS. Comparing bevacizumab (15 mg/kg) with chemotherapy to standard chemotherapy alone, for chemotherapy-naïve patients, the pooled OR of response rate was 2.741(95%CI: 2.046, 3.672), the pooled HR for disease progression was 0.645 (95%CI: 0.561, 0.743), and the pooled HR for death was 0.790 (95%CI: 0.674, 0.926), respectively. In addition, the adjusted HR for previously-treated patients was 0.680 (95%CI: 0.492, 0.942) comparing bevacizumab combined with chemotherapy to standard chemotherapy alone.Conclusions
Bevacizumab accompanied by chemotherapy was found to significantly improve patients'' response rate, progression free survival (PFS), and overall survival (OS) among chemotherapy-naïve patients compared to other targeted drugs in the treatment of non-small cell lung carcinoma (NSCLC). 相似文献14.
Cheng D Allen K Cohn W Connolly M Edgerton J Falk V Martin J Ohtsuka T Vitali R 《Innovations (Philadelphia, Pa.)》2005,1(2):61-74
OBJECTIVE:: This meta-analysis sought to determine whether endoscopic vascular graft harvesting (EVH) improves clinical and resource outcomes compared with conventional open graft harvesting (OVH) in adults undergoing coronary artery bypass surgery. METHODS:: A comprehensive search was undertaken to identify all randomized and nonrandomized trials of EVH versus OVH up to April 2005. The primary outcome was wound complications. Secondary outcomes included any other clinical morbidity and resource utilization. Odds ratios (OR), weighted mean differences (WMD), or standardized mean differences (SMD) and their 95% confidence intervals (95% CI) were analyzed. RESULTS:: Thirty-six trials of 9,632 patients undergoing saphenous vein harvest met the inclusion criteria (13 randomized; 23 nonrandomized). Risk of wound complications was significantly reduced by EVH compared with OVH (OR 0.31, 95% CI 0.23-0.41). Similarly, the risk of wound infections was significantly reduced (OR 0.23, 95% CI 0.20-0.53; P < 0.0001). Need for surgical wound intervention was also significantly reduced (OR 0.16, 95% CI 0.08-0.29). The incidence of pain, neuralgia, and patient satisfaction was improved with EVH compared with OVH. Postoperative myocardial infarction, stroke, reintervention for ischemia or angina recurrence, and mortality were not significantly different. Operative time was significantly increased (WMD 15.26 minutes; 95% CI 0.01, 30.51), hospital length of stay was reduced (WMD -0.85 days; 95% CI -1.55, -0.15), and readmissions were reduced (OR 0.53, 95% CI 0.29-0.98). Costs were insufficiently reported to allow for aggregate analysis. CONCLUSIONS:: Endoscopic vascular graft harvesting of the saphenous vein reduces wound complications and improves patient satisfaction and resource utilization. Further research is required to determine the incremental cost-effectiveness of EVH versus OVH. 相似文献
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Ying-Ren Chen Kuo-Wei Hung Jui-Chen Tsai Hsin Chu Min-Huey Chung Su-Ru Chen Yuan-Mei Liao Keng-Liang Ou Yue-Cune Chang Kuei-Ru Chou 《PloS one》2014,9(8)
Background
We performed the first meta-analysis of clinical studies by investigating the effects of eye-movement desensitization and reprocessing (EMDR) therapy on the symptoms of posttraumatic stress disorder (PTSD), depression, anxiety, and subjective distress in PTSD patients treated during the past 2 decades.Methods
We performed a quantitative meta-analysis on the findings of 26 randomized controlled trials of EMDR therapy for PTSD published between 1991 and 2013, which were identified through the ISI Web of Science, Embase, Cochrane Library, MEDLINE, PubMed, Scopus, PsycINFO, and the Cumulative Index to Nursing and Allied Health Literature electronic databases, among which 22, 20, 16, and 11 of the studies assessed the effects of EMDR on the symptoms of PTSD, depression, anxiety, and subjective distress, respectively, as the primary clinical outcome.Results
The meta-analysis revealed that the EMDR treatments significantly reduced the symptoms of PTSD (g = −0.662; 95% confidence interval (CI): −0.887 to −0.436), depression (g = −0.643; 95% CI: −0.864 to −0.422), anxiety (g = −0.640; 95% CI: −0.890 to −0.390), and subjective distress (g = −0.956; 95% CI: −1.388 to −0.525) in PTSD patients.Conclusion
This study confirmed that EMDR therapy significantly reduces the symptoms of PTSD, depression, anxiety, and subjective distress in PTSD patients. The subgroup analysis indicated that a treatment duration of more than 60 min per session was a major contributing factor in the amelioration of anxiety and depression, and that a therapist with experience in conducting PTSD group therapy was a major contributing factor in the reduction of PTSD symptoms. 相似文献18.
Chad K. Bush Dayaamayi Kurimella Lee J. S. Cross Katherine R. Conner Sheryl Martin-Schild Jiang He Changwei Li Jing Chen Tanika Kelly 《PloS one》2016,11(1)
Importance
Acute ischemic stroke is a leading cause of death and disability worldwide. Several recent clinical trials have shown that endovascular treatment improves clinical outcomes among patients with acute ischemic stroke.Objective
To provide an overall and precise estimate of the efficacy of endovascular treatment predominantly using second-generation mechanical thrombectomy devices (stent-retriever devices) compared to medical management on clinical and functional outcomes among patients with acute ischemic stroke.Data Sources
MEDLINE, EMBASE, Cochrane Collaboration Central Register of Controlled Clinical Trials, Web of Science, and NIH ClinicalTrials.gov were searched through November 2015.Study Selection
Searches returned 3,045 articles. After removal of duplicates, two authors independently screened titles and abstracts to assess eligibility of 2,495 potentially relevant publications. From these, 38 full-text publications were more closely assessed. Finally, 5 randomized controlled trials of endovascular treatment with predominant use of retrievable stents were selected.Data Extraction and Synthesis
Three authors independently extracted information on participant and trial characteristics and clinical events using a standardized protocol. Random effects models were used to pool endovascular treatment effects across outcomes.Main Outcomes and Measures
The primary outcome was better functional outcome as measured on the modified Rankin Scale at 90 days of follow-up. Secondary outcomes included all-cause mortality and symptomatic intra-cerebral hemorrhage.Results
Five trials representing 1,287 patients were included. Overall, patients randomized to endovascular therapy experienced 2.22 times greater odds of better functional outcome compared to those randomized to medical management (95% CI, 1.66 to 2.98; P < 0.0001). Endovascular therapy was not associated with mortality [OR (95% CI), 0.78 (0.54, 1.12); P = 0.1056] or symptomatic intracerebral hemorrhage [OR (95% CI), 1.19 (0.69, 2.05); P = 0.5348]. Meta-regression analysis suggested that shorter times from stroke onset to groin puncture and from stroke onset to reperfusion result in better functional outcomes in ischemic stroke patients (P = 0.0077 and P = 0.0089). There were no significant differences in the beneficial effects of endovascular treatment on functional outcomes across categories of gender, age, stroke severity, ischemic changes on computed tomography, or intravenous tissue plasminogen activator administration.Conclusions and Relevance
This meta-analysis demonstrated superior functional outcomes in subjects receiving endovascular treatment compared to medical management. Further, this analysis showed that acute ischemic stroke patients may receive enhanced functional benefit from earlier endovascular treatment. 相似文献19.
Treva Rice Angelo Tremblay Olivier Driaz Louis Prusse D.C. Rao Claude Bouchard 《Obesity (Silver Spring, Md.)》1996,4(5):441-449
A major gene hypothesis for resting metabolic rate (RMR) was investigated using segregation analysis (POINTER) of data on families participating in Phase 2 of the Québec Family Study. Complete analyses were conducted on RMR adjusted for age, and also on RMR adjusted for age and other covariates, primarily fat mass (FM) and fat-free mass (FFM). Prior to adjustment for covariates, support for a major gene hypothesis was equivocal — i.e., there was evidence for either a major gene or a multifactorial component (i.e., polygenic and/or familial environment). The multifactorial model was preferred over the major gene model, although the latter did segregate according to Mendelian expectations. However, after the effects of FM and FFM were accounted for, a major gene effect was unambiguous and compelling. The putative locus accounted for 57% of the variance, affected 7% of the sample, and led to high values of RMR. The lack of a significant multifactorial effect suggested that the familial etiology of RMR adjusted for FM and FFM was likely to be entirely a function of the major locus. Comparing the RMR results from pre- and post-adjustment for FM and FFM suggests a plausible hypothesis. We know from earlier studies in this sample that there is a putative major gene for FM and a major non-Mendelian effect for FFM. The current study leads us to speculate that: (1) the gene(s) affecting body size and body composition also may have an effect on RMR, and further (2) removal of the effect of the major gene(s) for body size and composition allowed for detection of an additional major gene affecting only the RMR. Thus, RMR appears to be an oligogenic trait. 相似文献