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Clustered regularly interspaced short palindromic repeats (CRISPR) is a powerful tool that enables editing of the axolotl genome. In this chapter, we will cover how to retrieve gene sequences, confirm annotation, design CRISPR targets, analyze indels, and screen for Crispant axolotls. This is a comprehensive guide on how to use CRISPR on your favorite gene and gain insights into its function., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Regeneration is an elegant and complex process informed by both local and long-range signals. Many current studies on regeneration are largely limited to investigations of local modulators within a canonical cohort of model organisms. Enhanced genetic tools increasingly enable precise temporal and spatial perturbations within these model regenerators, and these have primarily been applied to cells within the local injury site. Meanwhile, many aspects of broader spatial regulators of regeneration have not yet been examined with the same level of scrutiny. Recent studies have shed important insight into the significant effects of environmental cues and circulating factors on the regenerative process. These observations highlight that consideration of more systemic and possibly more broadly acting cues will also be critical to fully understand complex tissue regeneration. In this review, we explore the ways in which systemic cues and circulating factors affect the initiation of regeneration, the regenerative process, and its outcome. As this is a broad topic, we conceptually divide the factors based on their initial input as either external cues (for example, starvation and light/dark cycle) or internal cues (for example, hormones); however, all of these inputs ultimately lead to internal responses. We consider studies performed in a diverse set of organisms, including vertebrates and invertebrates. Through analysis of systemic mediators of regeneration, we argue that increased investigation of these "systemic factors" could reveal novel insights that may pave the way for a diverse set of therapeutic avenues.

How salamanders accomplish progenitor cell proliferation while faithfully maintaining genomic integrity and regenerative potential remains elusive. Here we found an innate DNA damage response mechanism that is evident during blastema proliferation (early- to late-bud) and studied its role during tissue regeneration by ablating the function of one of its components, Eyes absent 2. In eya2 mutant axolotls, we found that DNA damage signaling through the H2AX histone variant was deregulated, especially within the proliferating progenitors during limb regeneration. Ultimately, cell cycle progression was impaired at the G1/S and G2/M transitions and regeneration rate was reduced. Similar data were acquired using acute pharmacological inhibition of the Eya2 phosphatase activity and the DNA damage checkpoint kinases Chk1 and Chk2 in wild-type axolotls. Together, our data indicate that highly-regenerative animals employ a robust DNA damage response pathway which involves regulation of H2AX phosphorylation via Eya2 to facilitate proper cell cycle progression upon injury., Competing Interests: KS, DB, JM, SE, ST, GG, JH, KC, ML, JW No competing interests declared, (© 2020, Sousounis et al.)

Background: Microscopic hematuria is a common incidental finding on routine urinalysis. Although there are no clear recommendations to perform routine urinalysis, some studies have shown that up to 50% of general practitioners continue to perform annual routine urinalysis regardless of age or risk factors. The aim of this study was to identify associated factors and prevalence of dipstick microscopic hematuria in the general male population presenting to an annual public men's health fair., Method: We conducted a retrospective analysis of prospectively collected data at an annual Men's Health fair from 2008 to 2013. Patient reported health questionnaires, basic physical exam including digital rectal exam, basic bloodwork and dipstick urinalysis data was examined., Results: A total of 979 patients were reviewed. Of these, 850 provided a urine sample and were included in the final analysis. Seventy-three (8.6%) patients had positive hematuria on urinalysis. Average age in both groups was 55 years. Presence of microscopic hematuria was correlated with presence of diabetes and proteinuria with odds-ratio of 2.8 (1.3-5.8) and 2.9 (1.7-5.0) respectively on multivariate analysis. There was no significant correlation identified with age, hypertension, coronary artery disease, body-mass index, smoking, prostate specific antigen (PSA) or International Prostate Symptom Score (IPSS). Limitation of this study is the lack of follow-up and knowledge of subsequent investigations of patients., Conclusion: Microscopic hematuria is a prevalent condition in the male population presenting to a health fair. The only factors associated with microscopic hematuria were diabetes and proteinuria. No association was found between hematuria and smoking, age, or lower urinary tract symptoms.

Background and Objectives: Concern about allogeneic blood product cost and complications has prompted interest in blood conservation techniques. Intraoperative autotransfusion (IAT) is currently not used routinely by vascular surgeons in open elective infrareanl abdominal aortic aneurysm (AAA) repair. The objective of this study is to review our experience with IAT and its impact on blood transfusion., Methods: We retrospectively reviewed the medical records of consecutive patients treated electively over a 4-year period and compared 2 strategy related to IAT, routine use IAT (rIAT) versus on-demand IAT (oIAT). Outcomes measured were number of units of allogeneic red blood cells and autologous red blood cells transfused intraoperatively and postoperatively, preoperative, postoperative, and discharge hemoglobin levels; postoperative infections; length of postoperative intensive care stay; and length of hospital stay. T-independent and Fisher exact test were used., Results: A total of 212 patients were included, 38 (18%) in the rIAT and 174 (82%) in the oIAT. Groups were similar except for an inferior creatinine and a superior mean aneurysm diameter for the rIAT group. Patients in the rIAT group had a lower rate of transfusion (26% vs 54%, P = .002) and a lower mean number of blood unit transfused (0.8 vs 1.8, P = .048). These findings were still more significant for AAA larger than 60 mm (18% rIAT vs 62% oIAT, P = .0001). Postoperative hemoglobin was superior in the rIAT group (107 vs 101 g/L, P = .01). Mean postoperative intensive care length of stay was shorter for the rIAT group (1.1 vs 1.8 days, P = .01). No difference was noted for infection, mortality, or hospital length of stay., Conclusion: The rIAT reduced the exposure to allogeneic blood products by more than 50%, in particular for patients with AAA larger than 60 mm. These results support the use of rIAT for open elective infrarenal AAA repair.