41 Review Immune Cells in Animal Burn Models deviation, unit of measurement, number of animals), each from half of the included studies and checked at least 10% of the other reviewer. The following outcome measures in either blood or wound tissue were included: immune cell counts, immune cell migration assays, antibacterial activity, production of inflammatory mediators or reactive oxygen species by specific cell types and apoptosis. Data from graphs was extracted using the digital ruler feature in ImageJ (version 1.53j; NIH [56]). In case of missing data, such as the number of animals or standard deviation, we contacted corresponding authors via email and ResearchGate (including a reminder after two weeks) (response rate 17%). Data presented as standard error of mean (SEM) were transformed to standard deviation (SD) with the following formula: SD = SEM * number of animals. Synthesis of results and meta-analysis Meta-analyses were only performed on outcome measures of at least five studies. Data were analyzed using Comprehensive Meta-Analysis (version 3; Biostat, Englewood, NJ), and the effect sizes were expressed as standardized mean difference of immune cell counts in blood or wound tissue from burn-injured animals compared with counts in blood or skin from uninjured animals (baseline or uninjured control) with 95% confidence interval. A random-effects model was used in the analyses, and I2 statistic was used as a measure for statistical heterogeneity. Cell types that were considered the same entity were pooled (Supplementary Table 1). Possible publication bias was explored using Duval and Tweedie’s trim and fill methodology (Supplementary File 2). NLRs were calculated using absolute data from studies that measured both blood neutrophil and lymphocyte counts. Subgroup analysis Predefined subgroup analyses were performed on: time post burn (divided into categories 0-1, 2-4, 5-9, 10-14, 15-21, 22-28 or >29 days), burned total body surface area (TBSA, ≤5%, 5%-25% or >25%), wound depth (superficial, partial-thickness, deep dermal or full-thickness), burn agent (flame, water or metal), animal species (mouse, rat or pig), sex and age (young or adult). In the case of repeated measures within a time interval, the maximum effect size per time interval was chosen. When required, TBSA was calculated using the reported area of the burn, weight (W) of the animals and MeehRubner’s formula () (Gouma et al. 2012). The following K values were used: 9 (mouse), 9,83 (rat), 12 (rabbit), 10,5 (guinea pig), 10,1 (dog) and 10 (pig). When TBSA was missing in the articles, it was estimated based on the reported age and weight information available at Animal Resources Centre (https://www.arc.wa.gov.au/), The Jackson Laboratory (https:// www.jax.org/), and Roysfarm (https://www.roysfarm.com/). Using the weight of animal, the animal age was estimated when this was not reported. Animal age subgroups, young or adult, was based on social maturity of animals: adults were >3 months (mouse), >6 2
RkJQdWJsaXNoZXIy MTk4NDMw