Blood contains cfDNA fragments derived from dying cells 1 . cfDNA has a half-life of ~15 min 2 and, therefore, represents events that occurred close to sampling time. cfDNA analysis is used for assessment of fetus chromosomal aberrations, graft rejection, monitoring tumor dynamics and targeted treatment [3][4][5][6][7] . These applications rely on genetic differences between the host and the tissue of interest. Analysis of CpG methylation in cfDNA is emerging as an alternative independent of genetic alteration 5,[8][9][10][11] . CpG methylation profiles are determined during differentiation and are stable afterwards and, thus, are highly informative about cell identity (for example, liver or lung). However, genetic and methylation-based approaches do not report on recent transcriptional events, as mutations and methylation changes occur over developmental time scales.The basic repeating unit of chromatin is the nucleosome, which is a histone-DNA complex encompassing ~150 base pairs (bp) of DNA 12 . Histone proteins are subject to multiple covalent modifications, which are involved in nearly all aspects of messenger RNA (mRNA) biogenesis [13][14][15][16] . Histone modification patterns reflect recent events related to chromatin regulation and activity of RNA polymerase 13,15 , and different combinations of such modifications mark the location and activity of non-coding regions, enhancers, promoters and gene bodies [17][18][19][20][21][22] . Chromatin immunoprecipitation and sequencing (ChIP-seq) enables genome-wide mapping of histone modifications and provides detailed understanding of the regulatory activity within cells [17][18][19][23][24][25][26][27] .Upon cell death, the genome is fragmented, and chromatin, mostly in the form of nucleosomes, is released into the circulation as cell-free nucleosomes (cf-nucleosomes) 28-30 that retain some histone modifications [31][32][33] . We reasoned that capturing and DNA sequencing of modified nucleosomes from plasma might inform on DNA-related activities, including transcription, within the cells of origin (Fig. 1a). This currently inaccessible epigenetic information extends beyond cfDNA modalities examined to date [4][5][6][7][8][9][10][11][34][35][36][37][38][39][40][41][42][43] .In this study, we performed chromatin immunoprecipitation and sequencing of cell-free nucleosomes directly from human plasma (cfChIP-seq). We show that cfChIP-seq recapitulates the original genomic distribution of modifications associated with transcriptionally active promoters, enhancers and gene bodies, demonstrating that plasma nucleosomes retain the epigenetic information of their

Malignant cell growth is fueled by interactions between tumor cells and the stromal cells composing the tumor microenvironment. The human liver is a major site of tumors and metastases, but molecular identities and intercellular interactions of different cell types have not been resolved in these pathologies. Here, we apply single cell RNA‐sequencing and spatial analysis of malignant and adjacent non‐malignant liver tissues from five patients with cholangiocarcinoma or liver metastases. We find that stromal cells exhibit recurring, patient‐independent expression programs, and reconstruct a ligand–receptor map that highlights recurring tumor–stroma interactions. By combining transcriptomics of laser‐capture microdissected regions, we reconstruct a zonation atlas of hepatocytes in the non‐malignant sites and characterize the spatial distribution of each cell type across the tumor microenvironment. Our analysis provides a resource for understanding human liver malignancies and may expose potential points of interventions.

Bariatric surgery dramatically improves glycemic control, yet the underlying molecular mechanisms remain controversial because of confounding weight loss. We performed sleeve gastrectomy (SG) on obese and diabetic leptin receptor-deficient mice (/). One week postsurgery, mice weighed 5% less and displayed improved glycemia compared with sham-operated controls, and islets from SG mice displayed reduced expression of diabetes markers. One month postsurgery SG mice weighed more than preoperatively but remained near-euglycemic and displayed reduced hepatic lipid droplets. Pair feeding of SG and sham / mice showed that surgery rather than weight loss was responsible for reduced glycemia after SG. Although insulin secretion profiles from islets of sham and SG mice were indistinguishable, clamp studies revealed that SG causes a dramatic improvement in muscle and hepatic insulin sensitivity accompanied by hepatic regulation of hepatocyte nuclear factor-α and peroxisome proliferator-activated receptor-α targets. We conclude that long-term weight loss after SG requires leptin signaling. Nevertheless, SG elicits a remarkable improvement in glycemia through insulin sensitization independent of reduced feeding and weight loss.

Adult-to-adult living donor liver transplantation (LDLT) was introduced in response to the shortage of deceased donor liver grafts. The number of adult living donor transplants is increasing due to improved outcomes and increasing need. Advantages of LDLT include optimization of the timing of transplant, better organ quality, and lower rates of recipient mortality compared to staying on the wait list for deceased donor liver transplant. Donor safety remains the major focus when considering LDLT. Recent advancements have supported the increased use of LDLT to help decrease wait list death and improve long-term survival of transplant recipients.

The current data lead to the conclusion that laparoscopic paraduodenal hernia repair is a safe and feasible approach for selected patients. It can be expected that as surgeons become increasingly comfortable and facile with laparoscopic techniques, paraduodenal hernias and many other causes of acute small bowel obstruction will be increasingly managed laparoscopically.

Erythropoietic protoporphyria (EPP) is a rare inherited disorder of the heme biosynthesis pathway resulting in the accumulation of protoporphyrins in the blood, erythrocytes, and other tissues. Because of a gene mutation in the FECH gene, ferrochelatase, the enzyme involved in the final step of heme synthesis, is deficient in these patients. Although the major symptom of this disorder is photosensitivity, rarely, it can cause progressive liver disease requiring liver transplantation (LT). However, LT is not curative and only bone marrow transplantation (BMT) can correct the underlying enzymatic defect. Because liver disease results from accumulation of protoporphyrin in the liver, LT without hematopoietic stem cell transplantation leaves the new liver at risk for similar EPP-related damage. A handful of pediatric patients undergoing sequential LT and stem cell transplantation have been described in the literature; however, to date none has been described in detail in adults. We report a case of an adult male with EPP and liver failure who successfully underwent a sequential liver and hematopoietic stem cell transplantation (HSCT).

Kidney transplantation at the time of the COVID-19 pandemic is challenging. Modifying the immunosuppression protocols is controversial and not evidence based. In this study, we aim to review the published literature of kidney transplant recipients who encountered COVID-19. A literature review was performed using PubMed, ScienceDirect, and World Health Organization databases to identify relevant English-language articles published up to May 7, 2020. There were 24 articles that reported 129 kidney transplant recipients who encountered COVID-19. The age mean was 54.2 years with 73.7% as males. The most commonly reported presentations in order were fever (82.3%), cough (58%), shortness of breath (33.2%), and fatigue (30.7%). Acute kidney injury was observed in 34.1% of patients. Kidney transplant patients encountered COVID-19 were maintained on tacrolimus (Tac, 92%), mycophenolate mofetil (MMF, 78.8%), and prednisone (Pred, 77%) and were manage by holding MMF in 79.1% of patients and holding Tac in 34.4% of patients. In all, 20% of patients needed Intensive Care Unit (ICU) admission and 24.6% of patients required mechanical ventilation. In all, 18.8% of patients had died compared to the reported general population COVID-19 mortality of 3.4%. The clinical presentation of COVID-19 in kidney transplant recipients may be different from the general population with a higher rate of severe disease, complications including renal failure, and mortality.

Objective In the era of organ shortage, redo liver transplantation (reLT) is frequently discussed in terms of expected poor outcome, high cost and therefore wasteful resources. However, there is a lack of benchmark data to reliably assess outcomes after reLT. The aim of this study was to define the ideal reLT case, and to establish clinically relevant benchmark values for best achievable outcome in reLT. Methods We collected data on reLT between January 2010 and December 2018 from 22 high volume transplant centers on three continents. Benchmark cases were defined as recipients with model of end-stage liver disease score <=25, absence of portal vein thrombosis, no mechanical ventilation before surgery, receiving a graft from a donor after brain death. In addition, early reLT including those for primary non-function (PNF) were excluded. Clinically relevant endpoints covering intra- and postoperative course were selected and complications were graded by severity using the Clavien-Dindo classification and the comprehensive complication index (CCI). The benchmark cutoff for each outcome was derived from the 75th percentile of the median values of all benchmark centers, indicating the “best achievable” result. To assess the utility of the newly established benchmark values, we analyzed patients who received reLT for PNF (non-benchmark patients). Results Out of 1110 reLT 413 (37.2%) qualified as benchmark cases. Benchmark values included: Length of intensive care unit and hospital stay: <=6 and <=24 days, respectively; Clavien-Dindo grade >=3a complications and the CCI at 1 year: <=76% and <=72.2, respectively; in-hospital and 1-year mortality rates: <=14.0% and <=14.3%, respectively. The cutoffs for transplant-specific complications such as biliary complications at 1 year, outflow problems at 1 year and hepatic artery thrombosis at discharge were <=27.3%, <=2.5% and <=4.8%, respectively. Patients receiving a reLT for PNF showed mean outcome values all outside the reLT benchmark values. In-hospital mortality rate was 34.4% and the mean CCI at discharge 68.8. Conclusion ReLT remains associated with high morbidity and mortality. The availability of benchmark values for outcome parameters of reLT may serve for comparison in any future analyses of individuals, patient groups, or centers, but also in the evaluation of new therapeutic strategies and principles.