Scaffold Biomaterials in Tissue Regeneration in Surgery

This chapter will focus on the subject of tissue regeneration in a variety of different surgical fields and operations. We will explore the use of acellular dermal matrices, stem cell-based therapies, gene regulation, emerging 3D printing techniques and their potential applications in surgery. Acellular dermal matrices (ADMs) are biological materials derived from human or animal tissue through complicated and expensive decellularisation processes, leading to acellular material that can be used to aid tissue healing. ADMs were first introduced for the treatment of burn injuries, but are now widely used in a variety of surgical fields, including abdominal wall and breast reconstruction. A wide range of materials can be used to produce ADMs, but usually include bovine, porcine or human tissues (e.g., dermis and pericardium). ADMs act as scaffolds onto which human tissue can incorporate, allowing for an innovative, yet a very effective way to aid tissue regeneration. Stem cell therapies also hold promise in aiding tissue regeneration in the coming years and we will also explore techniques that are currently being researched by prominent scientists all across the world. For example, adipose tissue-derived stem cells (ASCs) are a potentially revolutionary therapy in regenerative medicine. We will review the current evidence available and consider the possible clinical applications of ASCs, including their potential to treat ischaemic diseases and their role in healing chronic wounds. ASCs are adult stem cells, which display similar morphology and differentiation properties to adult mesenchymal stem cells (MSCs). The multiple linage pathways displayed by ASCs allows a variety of tissues to be repaired and maintained. Moreover, adipose tissue is abundant, easily accessible and is able to be repeatedly harvested with low morbidity. Previously, autologous fat grafting was more commonly utilised for managing volume defects in reconstructive and plastic surgery; however, recent literature has revealed promising therapeutic effects of ASCs in tissue regeneration. Finally, gene regulation, which holds promise in musculoskeletal diseases, and 3D printed scaffolds that aid neural regeneration will also be discussed in this chapter as emerging, and potentially very promising, tissue regeneration techniques

Healthy ageing of cloned sheep

The health of cloned animals generated by somatic-cell nuclear transfer (SCNT) has been of concern since its inception; however, there are no detailed assessments of late-onset, non-communicable diseases. Here we report that SCNT has no obvious detrimental longterm health effects in a cohort of 13 cloned sheep. We perform musculoskeletal assessments, metabolic tests and blood pressure measurements in 13 aged (7–9 years old) cloned sheep, including four derived from the cell line that gave rise to Dolly. We also perform radiological examinations of all main joints, including the knees, the joint most affected by osteoarthritis in Dolly, and compare all health parameters to groups of 5- and 6-year-old sheep, and published reference ranges. Despite their advanced age, these clones are euglycaemic, insulin sensitive and normotensive. Importantly, we observe no clinical signs of degenerative joint disease apart from mild, or in one case moderate, osteoarthritis in some animals. Our study is the first to assess the long-term health outcomes of SCNT in large animals

Current practice of anticoagulant in the treatment of splanchnic vein thrombosis secondary to acute pancreatitis

Acknowledgment We thank Prof. Katsunori Imai (Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan) for help with translating some studies.Peer reviewedPostprin

A systematic review and meta-analysis of DNA methylation levels and imprinting disorders in children conceived by IVF/ICSI compared with children conceived spontaneously

BACKGROUND Increasing numbers of children are being conceived by assisted reproductive technology (ART). A number of studies have highlighted an altered epigenetic status in gametes from infertile couples and the possibility of an increased risk of imprinting defects and somatic epigenetic changes in ART conceived children, but the results have been heterogeneous. We performed a systematic review of existing studies to compare the incidence of imprinting disorders and levels of DNA methylation in key imprinted genes in children conceived through in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with those in children conceived spontaneously. METHODS A detailed search strategy was used to conduct electronic literature searches (spanning 1978 to 2013) on Medline, EMBASE, the Cochrane Library and Web of Science. Abstracts of relevant conference papers were identified. As randomized trials are not feasible in this context, we included observational (cohort and case–control) studies comparing outcomes in children conceived through ART with those conceived spontaneously, irrespective of the language of publication. The outcome measures were DNA methylation and the incidence of imprinting disorders. RESULTS A total of 351 publications were identified by the initial search. Of these, 26 were excluded as duplicates and 241 were excluded after reviewing the abstracts, then of those remaining 66 were excluded after review of the full text. A total of 18 papers were included in the review. Apart from one case–control study, all were cohort studies. There was a degree of clinical heterogeneity in terms of the study population, type of infertility treatment, and samples obtained from exposed and unexposed children. DNA methylation levels were either presented as categorical data (hypo-, hyper- or normally methylated DNA) or continuous data (i.e. percentage of methylated DNA). The combined odds ratio (95% confidence intervals) of any imprinting disorder in children conceived through ART was 3.67 (1.39, 9.74) in comparison with spontaneously conceived children. Meta-analysis of data from relevant studies revealed that the weighted mean difference (95% confidence intervals) in methylation percent between IVF/ICSI versus spontaneously conceived children were as follows: H19: −0.46(−1.41, 0.49), PEG1-MEST: 0.47 (−2.07, 3.01), GRB10: −0.05 (−0.43, 0.33), IGF2: −0.15 (−1.09, 0.79), SNRPN: −0.55 (−1.55, 0.46), KvDMR/KCNQ10T1: −0.16 (−0.34, 0.02) and PEG3: −0.24 (−1.72, 1.24). CONCLUSIONS There was an increase in imprinting disorders in children conceived though IVF and ICSI but insufficient evidence for an association between ART and methylation in other imprinted genes. Heterogeneity in the types of fertility treatment, the imprinted regions studied, the tissues used and the methods of measurement, reduce our ability to assess the full effect of ART on DNA methylation and imprinting. More controlled studies, using standardized methodologies, in larger, better clinically defined populations are needed