scholarly journals Composition differences between organic and conventional meat: a systematic literature review and meta-analysis

2016 ◽  
Vol 115 (6) ◽  
pp. 994-1011 ◽  
Author(s):  
Dominika Średnicka-Tober ◽  
Marcin Barański ◽  
Chris Seal ◽  
Roy Sanderson ◽  
Charles Benbrook ◽  
...  

AbstractDemand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA andn-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectively. However, for these and many other composition parameters, for which meta-analyses found significant differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Evidence from controlled experimental studies indicates that the high grazing/forage-based diets prescribed under organic farming standards may be the main reason for differences in FA profiles. Further studies are required to enable meta-analyses for a wider range of parameters (e.g. antioxidant, vitamin and mineral concentrations) and to improve both precision and consistency of results for FA profiles for all species. Potential impacts of composition differences on human health are discussed.

2021 ◽  
Vol 10 (13) ◽  
pp. 2760
Author(s):  
María León-López ◽  
Daniel Cabanillas-Balsera ◽  
Victoria Areal-Quecuty ◽  
Jenifer Martín-González ◽  
María C. Jiménez-Sánchez ◽  
...  

Aim. To conduct a systematic review and meta-analysis according to the following PICO question: in extracted human permanent teeth, does preflaring, compared with unflared canals, influence the accuracy of WL determination with EAL? Material and Methods. A systematic review was conducted according to the PRISMA checklist, using the following databases: PubMed, Science Direct, Scopus, and Web of Science. Studies related to WL determination using EAL both in preflared and unflared root canals of extracted human teeth were included. The outcome of interest was the accuracy of the electronic WL determination. A quality assessment of the included studies was performed, determining the risk of bias. The meta-analyses were calculated with the 5.4 RevMan software using the inverse variance method with random effects. PROSPERO registration: CRD42021243412. Results. Ten experimental studies fulfilled the inclusion criteria, and most of them found that preflaring increases the accuracy of the EALs in WL determination. The calculated OR was 1.98 (95% CI = 1.65–2.37; p < 0.00001; I2 = 10%), indicating that the determination of WL by EALs is almost twice as accurate in preflared canals. The accuracy of Root ZX in WL determination increases more than three times (OR = 3.25; p < 0.00001). Preflaring with Protaper files significantly increases the accuracy of EALs (OR = 1.76; p < 0.00001). The total risk of bias of the included studies was low. No obvious publication bias was observed. Conclusions. The results indicate a significant increase in the accuracy of WL determination with EAL after preflaring, doubling the percentage of exact measurements. Preflaring should be recommended as an important step during mechanical enlargement of the root canal, not only because it improves the access of the files to the canal, but also because it allows one to obtain more accurate electronic determinations of WL.


2021 ◽  
Vol 67 (1) ◽  
pp. 27-34
Author(s):  
Fernanda Cardoso ◽  
Jéssica Breder ◽  
Priscila Apolinário ◽  
Henrique Oliveia ◽  
Maria Saidel ◽  
...  

BACKGROUND: Plantago major is a medicinal plant that has been used for centuries to treat various health conditions including wounds. PURPOSE: To investigate the effectiveness of the topical use of P major in healing skin wounds in animal models. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted. Seven (7) electronic databases (Virtual Health Library, Public/Publisher MEDLINE, Scopus, Web of Science, Embase, Cumulative Index of Nursing and Allied Health Literature, and CAB Direct) were searched for controlled studies published in English from January 2006 to March 2020. The Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies tools guided the evaluation of the studies and determined their quality. The Systematic Review Center for Laboratory Animal Experimentation was used to assess the risk of bias. RESULTS: Of the 176 publications identified, 4 met the inclusion criteria. Studies included 20 to 100 animals and varying concentrations of P major. There were no reports of losses during research. Wound healing was assessed between 17 and 21 days following wounding. The best response in terms of wound contraction rate occurred with 10%, 20%, and 50% concentrations when compared with control groups. One (1) study did not have an animal ethics committee review. All studies had a high risk of bias and a lack of methodological rigor. CONCLUSION: The results of this review did not find evidence about the in vivo effectiveness of P major for wound healing. More rigorous preclinical studies with adequate sample sizes are required to identify the best concentrations and formulations as well as increase understanding about the mechanisms of action of P major in wound healing.


Author(s):  
Timothy T. Adeliyi ◽  
Ropo E. Ogunsakin ◽  
Marion O. Adebiyi ◽  
Oludayo O. Olugbara

Channel zapping delays are inconveniences that are often experienced by the subscribers of Internet protocol television (IPTV). It is a major bottleneck in the IPTV channels switching system that affect the quality of experience of users. Consequently, numerous channels switching approaches to minimize zapping delay in IPTV have been suggested. However, there is little knowledge reported in the literature on the determination of the strength of the evidence presented on the approaches of reducing zapping delay in IPTV, which is the prime purpose of this study. The extraction of the relevant articles was designed following the technique of preferred reporting items for systematic reviews and meta-analyses (PRISMA). All the included research articles were searched from the widely used databases of Google Scholar, and Web of Science. All statistical analyses were performed with the aid of the random-effects model implementation in Stata version 15. The overall pooled estimated delay component was presented in forest plots. Overall, thirteen studies were included in the meta-analysis and the overall pooled estimate was 10% (95% CI: 7%, 30%)). Experimental studies have shown that virtual elimination of IPTV zapping delay is possible for a relevant chunk of channel switching requests.


BMJ Open ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. e024886 ◽  
Author(s):  
Klaus Munkholm ◽  
Asger Sand Paludan-Müller ◽  
Kim Boesen

ObjectivesTo investigate whether the conclusion of a recent systematic review and network meta-analysis (Ciprianiet al) that antidepressants are more efficacious than placebo for adult depression was supported by the evidence.DesignReanalysis of a systematic review, with meta-analyses.Data sources522 trials (116 477 participants) as reported in the systematic review by Ciprianiet aland clinical study reports for 19 of these trials.AnalysisWe used the Cochrane Handbook’s risk of bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to evaluate the risk of bias and the certainty of evidence, respectively. The impact of several study characteristics and publication status was estimated using pairwise subgroup meta-analyses.ResultsSeveral methodological limitations in the evidence base of antidepressants were either unrecognised or underestimated in the systematic review by Ciprianiet al. The effect size for antidepressants versus placebo on investigator-rated depression symptom scales was higher in trials with a ‘placebo run-in’ study design compared with trials without a placebo run-in design (p=0.05). The effect size of antidepressants was higher in published trials compared with unpublished trials (p<0.0001). The outcome data reported by Ciprianiet aldiffered from the clinical study reports in 12 (63%) of 19 trials. The certainty of the evidence for the placebo-controlled comparisons should be very low according to GRADE due to a high risk of bias, indirectness of the evidence and publication bias. The mean difference between antidepressants and placebo on the 17-item Hamilton depression rating scale (range 0–52 points) was 1.97 points (95% CI 1.74 to 2.21).ConclusionsThe evidence does not support definitive conclusions regarding the benefits of antidepressants for depression in adults. It is unclear whether antidepressants are more efficacious than placebo.


2018 ◽  
Vol 49 (6) ◽  
pp. 881-890 ◽  
Author(s):  
Nicole N. Lønfeldt ◽  
Frank C. Verhulst ◽  
Katrine Strandberg-Larsen ◽  
Kerstin J. Plessen ◽  
Eli R. Lebowitz

AbstractExperts have raised concerns that oxytocin for labor induction and augmentation may have detrimental effects on the neurodevelopment of children. To investigate whether there is the reason for concern, we reviewed and evaluated the available evidence by searching databases with no language or date restrictions up to 9 September 2018. We included English-language studies reporting results on the association between perinatal oxytocin exposure and any cognitive impairment, psychiatric symptoms or disorders in childhood. We assessed the quality of studies using the Newcastle–Ottawa Quality Assessment Scales. Independent risk estimates were pooled using random-effects meta-analyses when at least two independent datasets provided data on the same symptom or disorder. Otherwise, we provided narrative summaries. Two studies examined cognitive impairment, one examined problem behavior, three examined attention-deficit/hyperactivity disorder (ADHD) and seven focused on autism spectrum disorders (ASD). We provided narrative summaries of the studies on cognitive impairment. For ADHD, the pooled risk estimate was 1.17; 95% confidence interval (CI) 0.77–1.78, based on a pooled sample size of 5 47 278 offspring. For ASD, the pooled risk estimate was 1.10; 95% CI 1.04–1.17, based on 8 87 470 offspring. Conclusions that perinatal oxytocin increases the risks of neurodevelopmental problems are premature. Observational studies of low to high quality comprise the evidence-base, and confounding, especially by the genetic or environmental vulnerability, remains an issue. Current evidence is insufficient to justify modifying obstetric guidelines for the use of oxytocin, which state that it should only be used when clinically indicated.


2008 ◽  
Vol 364 (1519) ◽  
pp. 929-942 ◽  
Author(s):  
Kristina A Pfannkuche ◽  
Anke Bouma ◽  
Ton G.G Groothuis

Lateralization of brain and behaviour has been the topic of research for many years in neuropsychology, but the factors guiding its development remain elusive. Based on sex differences in human lateralization, four hypotheses have been postulated that suggest a role for androgens, specifically testosterone. With the discovery that lateralization is a fundamental principle in the organization of brain and behaviour among vertebrates, it has now become possible to experimentally test such hypotheses in animal models. The use of different taxa, humans, other mammalian species and birds (with oestradiol and not testosterone involved in sexual differentiation in birds) facilitates to differentiate between the hypotheses. We used meta-analyses for analysing papers that provided sufficient information, and a semi-quantitative approach based on all relevant studies that we extracted from the literature. We tested the predictions of these hypotheses regarding strength and direction of lateralization for motor output, language and visuospatial cognition in these three taxa. We tested for sex differences and early organizational effects of testosterone (both correlative and experimental studies). We found sex differences in the direction of lateralization for non-human mammals (motor biases similar to humans) and in direction and strength in birds (visual cognitive tasks). However, the prediction that prenatal testosterone exposure affects the direction of lateralization was not supported for humans. In birds and non-human mammals, opposite trends were found, with the effect in non-human mammals being opposite to the expectation based on sex differences. None of the four hypotheses was sufficiently supported and more studies, testing a wider array of functions in different taxa while reporting the data more completely are needed.


2020 ◽  
Vol 27 (5) ◽  
pp. 805-817
Author(s):  
George A. Antoniou ◽  
Giuseppe Biondi-Zoccai ◽  
Francesco Versaci ◽  
Stavros A. Antoniou

The accrual of clinical studies poses important challenges to researchers and practitioners, especially in the field of endovascular therapy, where patient, lesion, technique, and device subtleties abound. Systematic reviews and meta-analyses may prove particularly fruitful in such settings by increasing statistical precision and bolstering external validity if the evidence base on a specific topic is consistent or by highlighting important discrepancies in the opposite scenario. However, mastering the correct approach to systematic review and meta-analysis is challenging for careful readers or for those interested in conducting such an evidence synthesis exercise. The present article highlights a stepwise approach to systematic reviews and meta-analyses, focusing on endovascular interventions, which will prove useful to anyone reading or wishing to synthesize the evidence base on endovascular topics to optimize decision making or shape future research efforts.


2021 ◽  
Vol 12 (3) ◽  
pp. 48
Author(s):  
Madalena Soveral ◽  
Vanessa Machado ◽  
João Botelho ◽  
José João Mendes ◽  
Cristina Manso

Subsurface enamel demineralization beneath an intact surface layer or white spots lesions (WSL) can and should be treated with non-invasive procedures to impede the development of a cavitated lesion. We aim to analyze if infiltrative resin improves enamel roughness, microhardness, shear bond strength, and penetration depth. MEDLINE [via Pubmed], Cochrane Central Register of Controlled Trials, Embase, Web of Science, Scholar, and LILACS were searched until May 2021. Methodological quality was assessed using the Joanna Briggs Institute Clinical Appraisal Checklist for Experimental Studies. Pairwise ratio of means (ROM) meta-analyses were carried out to compare the enamel properties after treatment with infiltrative resin on sound enamel and WSLs. From a total of 1604 articles, 48 studies were included. Enamel surface roughness decreased 35% in sound enamel (95%CI: 0.49–0.85, I2 = 98.2%) and 54% in WSLs (95%CI: 0.29–0.74, I2 = 98.5%). Microhardness reduced 24% in sound enamel (95%CI: 0.73–0.80, I2 = 99.1%) and increased by 68% in WSLs (95%CI: 1.51; 1.86, I2 = 99.8%). Shear bond strength reduced of 25% in sound enamel (95%CI: 0.60; 0.95, I2 = 96.9%) and increased by 89% in WSLs (95%CI: 1.28–2.79, I2 = 99.8%). Penetration depth was 65.39% of the WSLs (95%CI: 56.11–74.66, I2 = 100%). Infiltrative resins effectively promote evident changes in enamel properties in sound and WSLs. Future studies with long-term follow-ups are necessary to corroborate these results from experimental studies.


2012 ◽  
Vol 82 (3) ◽  
pp. 300-329 ◽  
Author(s):  
Erin Marie Furtak ◽  
Tina Seidel ◽  
Heidi Iverson ◽  
Derek C. Briggs

Although previous meta-analyses have indicated a connection between inquiry-based teaching and improved student learning, the type of instruction characterized as inquiry based has varied greatly, and few have focused on the extent to which activities are led by the teacher or student. This meta-analysis introduces a framework for inquiry-based teaching that distinguishes between cognitive features of the activity and degree of guidance given to students. This framework is used to code 37 experimental and quasi-experimental studies published between 1996 and 2006, a decade during which inquiry was the main focus of science education reform. The overall mean effect size is .50. Studies that contrasted epistemic activities or the combination of procedural, epistemic, and social activities had the highest mean effect sizes. Furthermore, studies involving teacher-led activities had mean effect sizes about .40 larger than those with student-led conditions. The importance of establishing the validity of the treatment construct in meta-analyses is also discussed.


Author(s):  
Dimitrios Schizas ◽  
Maximos Frountzas ◽  
Emmanouil Sgouromallis ◽  
Eleftherios Spartalis ◽  
Konstantinos S Mylonas ◽  
...  

Abstract Background The traditional technique of gastrointestinal reconstruction of the esophagus after esophagectomy presents plenty of complications. Hence, tissue engineering has been introduced as an effective artificial alternative with potentially fewer complications. Three types of esophageal scaffolds have been used in experimental studies so far. The aim of our meta-analysis is to present the postoperative outcomes after esophageal replacement with artificial scaffolds and the investigation of possible factors that affect these outcomes. Methods The present proportional meta-analysis was designed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and A MeaSurement Tool to Assess systematic Reviews guidelines. We searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL, and Google Scholar databases from inception until February 2020. Results Overall, 32 studies were included that recruited 587 animals. The pooled morbidity after esophageal scaffold implantation was 53.4% (95% CI = 36.6–70.0%). The pooled survival interval was 111.1 days (95% CI = 65.5–156.8 days). Graft stenosis (46%), postoperative dysphagia (15%), and anastomotic leak (12%) were the most common complications after esophageal scaffold implantation. Animals that underwent an implantation of an artificial scaffold in the thoracic part of their esophagus presented higher survival rates than animals that underwent scaffold implantation in the cervical or abdominal part of their esophagus (P &lt; 0.001 and P = 0.011, respectively). Conclusion Tissue engineering seems to offer an effective alternative for the repair of esophageal defects in animal models. Nevertheless, issues like graft stenosis and lack of motility of the esophageal scaffolds need to be addressed in future experimental studies before scaffolds can be tested in human trials.


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