Energy Requirements of Adult Dogs: A Meta-Analysis

A meta-analysis was conducted to determine the maintenance energy requirements of adult dogs. Suitable publications were first identified, and then used to generate relationships amongst energy requirements, husbandry, activity level, methodology, sex, neuter status, dog size, and age in healthy adult dogs. Allometric equations for maintenance energy requirements were determined using log-log linear regression. So that the resulting equations could readily be compared with equations reported by the National Research Council, maintenance energy requirements in the current study were determined in kcal/kg^0.75 body weight (BW). Ultimately, the data of 70 treatment groups from 29 publications were used, and mean (± standard deviation) maintenance energy requirements were 142.8±55.3 kcal.kgBW^−0.75.day⁻¹. The corresponding allometric equation was 81.5 kcal.kgBW^−0.93.day⁻¹ (adjusted R² = 0.64; 70 treatment groups). Type of husbandry had a significant effect on maintenance energy requirements (P<0.001): requirements were greatest in racing dogs, followed by working dogs and hunting dogs, whilst the energy requirements of pet dogs and kennel dogs were least. Maintenance energy requirements were less in neutered compared with sexually intact dogs (P<0.001), but there was no effect of sex. Further, reported activity level tended to effect the maintenance energy requirement of the dog (P = 0.09). This review suggests that estimating maintenance energy requirements based on BW alone may not be accurate, but that predictions that factor in husbandry, neuter status and, possibly, activity level might be superior. Additionally, more information on the nutrient requirements of older dogs, and those at the extremes of body size (i.e. giant and toy breeds) is needed.     

Epistasis Test in Meta-Analysis: A Multi-Parameter Markov Chain Monte Carlo Model for Consistency of Evidence

Conventional genome-wide association studies (GWAS) have been proven to be a successful strategy for identifying genetic variants associated with complex human traits. However, there is still a large heritability gap between GWAS and transitional family studies. The “missing heritability” has been suggested to be due to lack of studies focused on epistasis, also called gene–gene interactions, because individual trials have often had insufficient sample size. Meta-analysis is a common method for increasing statistical power. However, sufficient detailed information is difficult to obtain. A previous study employed a meta-regression-based method to detect epistasis, but it faced the challenge of inconsistent estimates. Here, we describe a Markov chain Monte Carlo-based method, called “Epistasis Test in Meta-Analysis” (ETMA), which uses genotype summary data to obtain consistent estimates of epistasis effects in meta-analysis. We defined a series of conditions to generate simulation data and tested the power and type I error rates in ETMA, individual data analysis and conventional meta-regression-based method. ETMA not only successfully facilitated consistency of evidence but also yielded acceptable type I error and higher power than conventional meta-regression. We applied ETMA to three real meta-analysis data sets. We found significant gene–gene interactions in the renin–angiotensin system and the polycyclic aromatic hydrocarbon metabolism pathway, with strong supporting evidence. In addition, glutathione S-transferase (GST) mu 1 and theta 1 were confirmed to exert independent effects on cancer. We concluded that the application of ETMA to real meta-analysis data was successful. Finally, we developed an R package, etma, for the detection of epistasis in meta-analysis [etma is available via the Comprehensive R Archive Network (CRAN) at https://cran.r-project.org/web/packages/etma/index.html].     

Micronutrients in HIV: A Bayesian Meta-Analysis

BackgroundApproximately 28.5 million people living with HIV are eligible for treatment (CD4<500), but currently have no access to antiretroviral therapy. Reduced serum level of micronutrients is common in HIV disease. Micronutrient supplementation (MNS) may mitigate disease progression and mortality.ObjectivesWe synthesized evidence on the effect of micronutrient supplementation on mortality and rate of disease progression in HIV disease.MethodsWe searched MEDLINE, EMBASE, the Cochrane Central, AMED and CINAHL databases through December 2014, without language restriction, for studies of greater than 3 micronutrients versus any or no comparator. We built a hierarchical Bayesian random effects model to synthesize results. Inferences are based on the posterior distribution of the population effects; posterior distributions were approximated by Markov chain Monte Carlo in OpenBugs.ConclusionsMNS significantly and substantially slows disease progression in HIV+ adults not on ARV, and possibly reduces mortality. Micronutrient supplements are effective in reducing progression with a posterior probability of 97.9%. Considering MNS low cost and lack of adverse effects, MNS should be standard of care for HIV+ adults not yet on ARV.     

Meta分析：综述中的一次大革命

科学研究应建立于许多实验结果的重复之上，除了少数新发现外，单个实验结果很难对科学的发展作出极为显著的贡献。所以为了阐明某一主题，在许多科学领域有众多研究者在对不同的实验对象或对同一对象在不同的实验环境中进行实验，如生态学中ＣＯ２倍增对植物光合作用的影响是目前一个比较热的话题，于是在短短的几年内就有大量的文章报道ＣＯ２倍增对各种植物光合作用的影响；在医学界，如胎教对婴儿智力的影响，吸烟与肺癌的相关程度等，都曾有大量的临床或调查实验对这些大众所关心的问题进行统计分析研究，但结果不尽相同。面对如此多结…     

Living with Wild Dogs: Personality Dimensions in Captive Dingoes (Canis dingo) and Implications for Ownership

Despite the commonly held belief that wild canines do not make “good” household companions, many people choose to live with them. The aim of the present study was to investigate owner-rated personality in a population of dingoes living as companion animals. Owners recruited from a registered dingo organization assessed the personality of 40 dingoes using the Monash Canine Personality Questionnaire- Revised (MCPQ-R). The dingoes (22 female; 18 male) ranged in age from 6 months to 11 years (M = 3.6 years, SD = 2.4); weighed an average of 19.07 kg (SD = 3.41); were mostly entire (i.e., not de-sexed or spayed or neutered; 62.5%) and lived in multiple dingo households (72.5%). Results show that dingoes were rated significantly higher than domestic dogs (n = 455; various breeds from a previous Australian study) for the dimension Motivation/Self-Assuredness (p < 0.001), and significantly lower than dogs for Training Focus (p < 0.001). Many of the personality traits of dingoes reside outside what is considered “ideal” characteristics important for a successful and rewarding dog–owner relationship. It is possible that dingo personality rests within the realms of what is “acceptable” pet canine behavior, at least for some owners, and that they may have adjusted their perception and attitudes to meet their expectations of the species. Motivations for dingo ownership and the applicability of using a domestic dog personality questionnaire on wild canids are discussed.     

Coping with Breast Cancer: A Meta-Analysis

Objective

The primary aim of this study was to examine the associations between different types of coping and psychological well-being and physical health among women with breast cancer. A second aim was to explore the potential moderating influences of situational and measurement factors on the associations between coping and psychological well-being and physical health.

Methods

On 14 February 2011, a literature search was made for articles published in the PubMed and PsycINFO databases before January 2010. On 5 September 2013, a repeated literature search was made for articles published before May 2013. In the final analyses, 78 studies with 11 948 participants were included.

Results

Efforts to facilitate adaptation to stress, such as Acceptance and Positive Reappraisal, were related to higher well-being and health. Disengagement and avoidance types of coping were associated with lower well-being and health. The analyses indicated that, in several circumstances, coping effectiveness was dependent on cancer stage, treatment, disease duration, and type of coping measure.

Conclusions

Use of coping targeting adjustment and avoiding use of disengagement forms of coping were related to better psychological well-being and physical health. Adaptive strategies and avoiding disengagement forms of coping seemed particularly beneficial for women undergoing treatment.     

Almost All Antipsychotics Result in Weight Gain: A Meta-Analysis

Introduction

Antipsychotics (AP) induce weight gain. However, reviews and meta-analyses generally are restricted to second generation antipsychotics (SGA) and do not stratify for duration of AP use. It is hypothesised that patients gain more weight if duration of AP use is longer.

Method

A meta-analysis was conducted of clinical trials of AP that reported weight change. Outcome measures were body weight change, change in BMI and clinically relevant weight change (7% weight gain or loss). Duration of AP-use was stratified as follows: ≤6 weeks, 6–16 weeks, 16–38 weeks and >38 weeks. Forest plots stratified by AP as well as by duration of use were generated and results were summarised in figures.

Results

307 articles met inclusion criteria. The majority were AP switch studies. Almost all AP showed a degree of weight gain after prolonged use, except for amisulpride, aripiprazole and ziprasidone, for which prolonged exposure resulted in negligible weight change. The level of weight gain per AP varied from discrete to severe. Contrary to expectations, switch of AP did not result in weight loss for amisulpride, aripiprazole or ziprasidone. In AP-naive patients, weight gain was much more pronounced for all AP.

Conclusion

Given prolonged exposure, virtually all AP are associated with weight gain. The rational of switching AP to achieve weight reduction may be overrated. In AP-naive patients, weight gain is more pronounced.     

Relationship between Periodontitis and Pre-Eclampsia: A Meta-Analysis

Background

Studies have suggested controversial results regarding a possible association between pre-eclampsia (PE) and periodontal disease (PD) and no meta-analysis has been performed to clarify this issue.

Methods

A literature search of electronic databases was performed for articles published through March 24, 2013, followed by a manual search of several dental and medical journals. The meta-analysis was conducted according to the recommendations of the Cochrane Collaboration and PRISMA. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed with the χ²-based Cochran Q test and I² statistic. The level of significance was set at P <0.05.

Results

Fifteen studies were included, including three cohort and 12 case-control studies. A positive association was found between PE and PD (OR 2.17, 95% CI 1.38–3.41, P = 0.0008). However, a high and significant heterogeneity was found (χ² = 62.42, P<0.00001, I² = 75%). In most cases, subgroup analysis had low power to detect significant differences between PE and non-PE groups.

Conclusion

Based on the findings of the meta-analysis, PD appears to be a possible risk factor for PE. However, given the important differences in the definitions and diagnoses of PD and PE among the studies, as well as their lack of good methodological quality, future trials are needed to confirm the results of the present meta-analysis.     

Single Gene Prognostic Biomarkers in Ovarian Cancer: A Meta-Analysis

Purpose

To discover novel prognostic biomarkers in ovarian serous carcinomas.

Methods

A meta-analysis of all single genes probes in the TCGA and HAS ovarian cohorts was performed to identify possible biomarkers using Cox regression as a continuous variable for overall survival. Genes were ranked by p-value using Stouffer’s method and selected for statistical significance with a false discovery rate (FDR) <.05 using the Benjamini-Hochberg method.

Results

Twelve genes with high mRNA expression were prognostic of poor outcome with an FDR <.05 (AXL, APC, RAB11FIP5, C19orf2, CYBRD1, PINK1, LRRN3, AQP1, DES, XRCC4, BCHE, and ASAP3). Twenty genes with low mRNA expression were prognostic of poor outcome with an FDR <.05 (LRIG1, SLC33A1, NUCB2, POLD3, ESR2, GOLPH3, XBP1, PAXIP1, CYB561, POLA2, CDH1, GMNN, SLC37A4, FAM174B, AGR2, SDR39U1, MAGT1, GJB1, SDF2L1, and C9orf82).

Conclusion

A meta-analysis of all single genes identified thirty-two candidate biomarkers for their possible role in ovarian serous carcinoma. These genes can provide insight into the drivers or regulators of ovarian cancer and should be evaluated in future studies. Genes with high expression indicating poor outcome are possible therapeutic targets with known antagonists or inhibitors. Additionally, the genes could be combined into a prognostic multi-gene signature and tested in future ovarian cohorts.     

Complications of Absorbable Fixation in Maxillofacial Surgery: A Meta-Analysis

Background

The use of titanium during maxillofacial fixation is limited due to its palpability, mutagenic effects and interference with imaging, which lead to the requirement for subsequent removal. The use of a biologically absorbable fixation material will potentially eliminate these limitations. In this meta-analysis, we analyzed the complications of absorbable fixation in maxillofacial surgery.

Methods

We performed a systematic search of PubMed, Embase, Cochrane Central Register of Systematic Reviews and Cochrane Central Register of Controlled Trials for trials published through December 2012. Data extracted from literature were analyzed with Review manager 5.0.24.

Results

Relevant data was extracted from 20 studies (1673 participants) and revealed that patients in the absorbable group had significantly more complications than those in the titanium group (RR = 1.20; 95% CI: 1.02–1.42; P = 0.03) in all enrolled maxillofacial surgeries. For bimaxillary operation subgroup, the absorbable fixation group did not have a significant increase in complications when compared with the titanium group (RR = 1.89; 95% CI: 0.85–4.22; P = 0.12). There was no significant difference observed between the absorbable and titanium groups receiving a bilateral sagittal split ramus osteotomy (BSSRO) (RR = 1.45; 95% CI: 0.84–2.48; P = 0.18) and Le Fort I osteotomy (RR = 0.65; 95% CI: 0.34–1.23; P = 0.18). The combined results of the five trials revealed that the absorbable group had a significantly lower rate of complications compared to the titanium group (RR = 0.71; 95% CI: 0.52–0.97; P = 0.03) in fracture fixation.

Conclusion

This meta-analysis shows that absorbable fixation systems used for fixation in maxillofacial surgery do not have adequate safety profiles. Subgroup indicated the safety of absorbable fixation systems was superior during fracture fixation. The absorbable fixation systems tend to have a similar favorable safety profile as titanium fixation during Le Fort I, bimaxillary operation and BSSRO.     

Rethinking Stress in Parents of Preterm Infants: A Meta-Analysis

Background

With improved medical outcome in preterm infants, the psychosocial situation of their families is receiving increasing attention. For parents, the birth of a preterm infant is generally regarded as a stressful experience, and therefore many interventions are based on reducing parental stress. Nevertheless, it remains unclear whether parents of children born preterm experience more stress than parents of term-born children, which would justify these interventions. This meta-analysis provides a comprehensive account of parental stress in parents of preterm infants, from birth of the infant through to their adolescence. Mean levels of stress in specific domains of family functioning were investigated, and stress levels in parents of preterm and term infants, and fathers and mothers of preterm infants, were compared. Furthermore, we investigated moderators of parental stress.

Methods and Findings

A random-effects meta-analysis was conducted including 38 studies describing 3025 parents of preterm (<37 wk) and low birth weight (<2500 g) infants. Parental stress was measured with two parent-reported questionnaires, the Parenting Stress Index and the Parental Stressor Scale: Neonatal Intensive Care Unit. The results indicate that parents of preterm-born children experience only slightly more stress than parents of term-born children, with small effect sizes. Furthermore, mothers have slightly more stress than fathers, but these effect sizes are also small. Parents report more stress for infants with lower gestational ages and lower birth weights. There is a strong effect for infant birth year, with decreasing parental stress from the 1980s onward, probably due to increased quality of care for preterm infants.

Conclusions

Based on our findings we argue that prematurity can best be regarded as one of the possible complications of birth, and not as a source of stress in itself.     

PD-L1 and Survival in Solid Tumors: A Meta-Analysis

Background

Numerous agents targeting PD-L1/PD-1 check-point are in clinical development. However, the correlation between PD-L1expression and prognosis of solid tumor is still in controversial. Here, we elicit a systematic review and meta-analysis to investigate the potential value of PD-L1 in the prognostic prediction in human solid tumors.

Methods

Electronic databases were searched for studies evaluating the expression of PD-L1 and overall survival (OS) of patients with solid tumors. Odds ratios (ORs) from individual studies were calculated and pooled by using a random-effect model, and heterogeneity and publication bias analyses were also performed.

Results

A total of 3107 patients with solid tumor from 28 published studies were included in the meta-analysis. The median percentage of solid tumors with PD-L1 overexpression was 52.5%. PD-L1 overexpression was associated with worse OS at both 3 years (OR = 2.43, 95% confidence interval (CI) = 1.60 to 3.70, P < 0.0001) and 5 years (OR = 2.23, 95% CI = 1.40 to 3.55, P = 0.0008) of solid tumors. Among the tumor types, PD-L1 was associated with worse 3 year-OS of esophageal cancer, gastric cancer, hepatocellular carcinoma, and urothelial cancer, and 5 year-OS of esophageal cancer, gastric cancer and colorectal cancer.

Conclusions

These results suggest that expression of PD-L1 is associated with worse survival in solid tumors. However, the correlations between PD-L1 and prognosis are variant among different tumor types. More studies are needed to investigate the clinical value of PD-L1 expression in prognostic prediction and treatment option.     

Hypertension and Risk of Cataract: A Meta-Analysis

Background

Cataract is the major cause of blindness across the world. Many epidemiologic studies indicated that hypertension might play an important role in the development of cataract, while others not. We therefore conducted this meta-analysis to determine the relationship between risk of cataract and hypertension.

Methods

Retrieved studies on the association of hypertension with cataract risk were collected from PubMed, Web of Science and the Cochrane Library during June 2014 and were included into the final analysis according to the definite inclusion criteria. Odds ratio (OR) or risk ratio (RR) were pooled with 95% confidence interval (CI) to evaluate the relationship between hypertension and cataract risk. Subgroup analyses were carried out on the basis of cataract type, race and whether studies were adjusted for main components of metabolic syndrome (MS).

Results

The final meta-analysis included 25 studies (9 cohort, 5 case-control and 11 cross-sectional) from 23 articles. The pooled results showed that cataract risk in populations with hypertension significantly increased among cohort studies (RR 1.08; 95% CI: 1.05–1.12) and case-control or cross-sectional studies (OR 1.28; 95% CI: 1.12–1.45). This association was proved to be true among both Mongolians and Caucasians, and the significance was not altered by the adjustment of main components of MS. Subgroup analysis on cataract types indicated that an increased incidence of posterior subcapsular cataract (PSC) resulted among cohort studies (RR 1.22; 95% CI: 1.03–1.46) and cross-sectional/case-control studies (OR 1.23; 95% CI: 1.09–1.39). No association of hypertension with risk of nuclear cataract was found.

Conclusions

The present meta-analysis suggests that hypertension increases the risk of cataract, especially PSC. Further efforts should be made to explore the potential biological mechanisms.     

Orthokeratology to Control Myopia Progression: A Meta-Analysis

ObjectiveTo evaluate the clinical treatment effects of orthokeratology to slow the progression of myopia.MethodsSeveral well-designed controlled studies have investigated the effects of orthokeratology in school-aged children. We conducted this meta-analysis to better evaluate the existing evidence. Relevant studies were identified in the Medline and Embase database without language limitations. The main outcomes included axial length and vitreous chamber depth reported as the mean ± standard deviation. The results were pooled and assessed with a fixed-effects model analysis. Subgroup analyses were performed according to geographical location and study design.ResultsOf the seven eligible studies, all reported axial length changes after 2 years, while two studies reported vitreous chamber depth changes. The pooled estimates indicated that change in axial length in the ortho-k group was 0.27 mm (95% confidence interval [CI]: 0.22, 0.32) less than the control group. Myopic progression was reduced by approximately 45%. The combined results revealed that the difference in vitreous chamber depth between the two groups was 0.22 mm (95% confidence interval [CI]: 0.14, 0.31). None of the studies reported severe adverse events.ConclusionThe overall findings suggest that ortho-k can slow myopia progression in school-aged children.     

Prevalence of Diabetic Retinopathy in Mainland China: A Meta-Analysis

Background

Although diabetic retinopathy (DR) is considered to be a major cause of blindness, this is the first meta-analysis to investigate the pooled prevalence of DR in mainland China.

Methodology/Principal Findings

We conducted a search of all English reports on population-based studies for the prevalence of DR using Medline, EMbase, Web of Science, Google (scholar), and all Chinese reports were identified manually and on-line using CBMDisc, Chongqing VIP database, and CNKI database. A meta-analysis was carried out. The fixed effects model or random effects model was used as a statistical test for homogeneity. Nineteen studies were included. The prevalence of DR, non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) in the pooled general population was 1.3% (95%CI: 0.5%–3.2%), 1.1% (95%CI: 0.6%–2.1%), and 0.1% (95%CI: 0.1%–0.3%), respectively, but was 23% (95%CI: 17.8%–29.2%), 19.1% (95%CI: 13.6%–26.3%), and 2.8% (95%CI: 1.9%–4.2%) in the diabetic group. The prevalence rate of DR in the pooled rural population was higher than that in the urban population, 1.6% (95%CI: 1.3%–2%), and the diabetic population, 29.1% (95%CI: 20.9%–38.9%). The prevalence of DR was higher in the Northern region compared with the Southern region.

Conclusions/Significance

The prevalence of DR in mainland China appeared a little high, and varied according to area. NPDR was more common. This study highlights the necessity for DR screening in the rural areas of China.     

Vitamin A Intake and Risk of Melanoma: A Meta-Analysis

Background

Mounting evidence from experimental and animal studies suggests that vitamin A may have a protective effect on melanoma, but the findings on the association of vitamin A intake with risk of melanoma have been inconsistently reported in epidemiologic studies. We attempted to elucidate the association by performing a meta-analysis.

Methods

Eligible studies were identified by searching PubMed and EMBASE databases, as well as by reviewing the references of retrieved publications. Summary odds ratios (OR) with corresponding 95% confidence interval (CI) were computed with a random-effects model. Study-specific ORs and 95% CIs for the highest vs. lowest categories of vitamin A intake were pooled.

Results

A total of 8 case-control studies and 2 prospective studies comprising 3,328 melanoma cases and 233,295 non-case subjects were included. The summary OR for the highest compared with the lowest intake of total vitamin A, retinol and beta-carotene was 0.86 (95% CI = 0.59–1.25), 0.80 (95% CI = 0.69–0.92) and 0.87 (95%CI = 0.62–1.20), respectively. Significant heterogeneity was observed among studies on vitamin A and beta-carotene intake, but not among studies on retinol intake. Subgroup and sensitivity analyses confirmed these findings. There was no indication of publication bias.

Conclusion

Findings from this meta-analysis suggest that intake of retinol, rather than of total vitamin A or beta-carotene, is significantly associated with reduced risk of melanoma.