Translational Research in Pediatrics IV: Solid Tissue Collection and Processing

Abstract

Solid tissues are critical for child-health research. Specimens are commonly obtained at the time of biopsy/surgery or postmortem. Research tissues can also be obtained at the time of organ retrieval for donation or from tissue that would otherwise have been discarded. Navigating the ethics of solid tissue collection from children is challenging, and optimal handling practices are imperative to maximize tissue quality. Fresh biopsy/surgical specimens can be affected by a variety of factors, including age, gender, BMI, relative humidity, freeze/thaw steps, and tissue fixation solutions. Postmortem tissues are also vulnerable to agonal factors, body storage temperature, and postmortem intervals. Nonoptimal tissue handling practices result in nucleotide degradation, decreased protein stability, artificial posttranslational protein modifications, and altered lipid concentrations. Tissue pH and tryptophan levels are 2 methods to judge the quality of solid tissue collected for research purposes; however, the RNA integrity number, together with analyses of housekeeping genes, is the new standard. A comprehensive clinical data set accompanying all tissue samples is imperative. In this review, we examined: the ethical standards relating to solid tissue procurement from children; potential sources of solid tissues; optimal practices for solid tissue processing, handling, and storage; and reliable markers of solid tissue quality.

DNA CpG methylation in sequential glioblastoma specimens

“…Although quality assessment revealed that DNA specimens from surgically removed FFPE GBM were significantly more fragmented than that of freshly obtained blood (fragments above 2000 bp in buffy coat: 70.18%; whole blood: 87.15%; GBM1: 21.65% and GBM2: 25.10%), these samples worked well in RRBS. However, because DNA quality was profoundly further compromised in the postmortem CG1 (mean fragment rate above 2000 bp: 5.91%), and the number of methylated CpG sites proportionally decreased with increasing fragmentation consistent with previous reports (Klughammer et al 2018;Wang et al 2013;Gillio-Meina et al 2016), we abandoned CG1, and focused all analyses on the CG2, GBM1 and GBM2 cohorts. CG2 included DNA CpG methylomes of five brain specimens obtained during epilepsy surgery (Klughammer et al 2018).…”

Chronic kidney disease stage affects small, dense low-density lipoprotein but not glycated low-density lipoprotein in younger chronic kidney disease patients: a cross-sectional study

“…The samples for the lipid study were selected at random based on the abundant samples available in the repository at the Translational Research Centre at the London Health Sciences Centre [ 17 ] and in an effort to have an even distribution of patients with CKD Stages 1–5. Other laboratory parameters that were necessary for our analysis were taken from our database (Microsoft Excel for Mac v.14.6.8) or from our centre’s electronic medical chart database.…”

T-cell Immunotherapies and the Role of Nonclinical Assessment: The Balance between Efficacy and Pathology

“…Most studies focus on healthy and tumor tissue, but consideration also needs to be given to other diseased tissues that may also result in the target antigen having enhanced expression. How the tissue samples have been collected and prepared is also important as antigen expression patterns may be very different between samples that have been promptly excised and fixed and those that may have been collected many hours postdeath at autopsy ( Gillio-Meina, Zielke, and Fraser 2016 ). In addition, information from online gene and protein expression databases may be supportive of the tissue expression patterns of the target antigen.…”