Altered Gene Expression Within the Renin-Angiotensin System in Normal Aging and Dementia.

The renin-angiotensin system (RAS) is dysregulated in Alzheimer's disease (AD). In this study, we have explored the hypothesis that an -age--related imbalance in brain RAS is a trigger for RAS dysregulation in AD. We characterized RAS gene expression in the frontal cortex from (i) a cohort of normal aging (n = 99, age range = 19-96 years) and (ii) a case-control cohort (n = 209) including AD (n = 66), mixed dementia (VaD + AD; n = 50), pure vascular dementia (VaD; n = 42), and age-matched controls (n = 51). The AD, mixed dementia, and age-matched controls were further stratified by Braak tangle stage (BS): BS0-II (n = 48), BSIII-IV (n = 44), and BSV-VI (n = 85). Gene expression was calculated by quantitative PCR (qPCR) for ACE1, AGTR1, AGTR2, ACE2, LNPEP, and MAS1 using the 2-∆∆Cq method, after adjustment for reference genes (RPL13 and UBE2D2) and cell-specific calibrator genes (NEUN, GFAP, PECAM). ACE1 and AGTR1, markers of classical RAS signaling, and AGTR2 gene expression were elevated in normal aging and gene expression in markers of protective downstream regulatory RAS signaling, including ACE2, MAS1, and LNPEP, were unchanged. In AD and mixed dementia, AGTR1 and AGTR2 gene expression were elevated in BSIII-IV and BSV-VI, respectively. MAS1 gene expression was reduced at BSV-VI and was inversely related to parenchymal Aß and tau load. LNPEP gene expression was specifically elevated in VaD. These data provide novel insights into RAS signaling in normal aging and dementia.

Pathological changes within the cerebral vasculature in Alzheimer's disease: New perspectives.

Cerebrovascular disease underpins vascular dementia (VaD), but structural and functional changes to the cerebral vasculature contribute to disease pathology and cognitive decline in Alzheimer's disease (AD). In this review, we discuss the contribution of cerebral amyloid angiopathy and non-amyloid small vessel disease in AD, and the accompanying changes to the density, maintenance and remodelling of vessels (including alterations to the composition and function of the cerebrovascular basement membrane). We consider how abnormalities of the constituent cells of the neurovascular unit - particularly of endothelial cells and pericytes - and impairment of the blood-brain barrier (BBB) impact on the pathogenesis of AD. We also discuss how changes to the cerebral vasculature are likely to impair Aß clearance - both intra-periarteriolar drainage (IPAD) and transport of Aß peptides across the BBB, and how impaired neurovascular coupling and reduced blood flow in relation to metabolic demand increase amyloidogenic processing of APP and the production of Aß. We review the vasoactive properties of Aß peptides themselves, and the probable bi-directional relationship between vascular dysfunction and Aß accumulation in AD. Lastly, we discuss recent methodological advances in transcriptomics and imaging that have provided novel insights into vascular changes in AD, and recent advances in assessment of the retina that allow in vivo detection of vascular changes in the early stages of AD.

Development of a Scalable Three-Dimensional Culture of Human Induced Pluripotent Stem Cells-Derived Liver Organoids.

Human induced pluripotent stem cells (hiPSCs) represent a powerful tool for the generation of specialized cells to be used in regenerative medicine as well as hepatocellular repopulation tool to treat liver metabolic diseases such as nonalcoholic steatohepatitis (NASH). Here we describe a strategy to obtain fully functional liver organoids from hiPSCs in a scalable manner. Our approach uses a two-step process, with a first step involving the scalable formation of homogeneous and uniform-sized human embryoid bodies (hEBs), followed by the application of a four-step liver differentiation protocol for the derivation of liver organoids that possess all the features of primary human hepatocytes. This chapter will also illustrate the characterization of the liver organoids by directed biomolecular techniques.

The vulnerable versatility of Salmonella antibiotic persisters during infection.

Tolerance and persistence are superficially similar phenomena by which bacteria survive bactericidal antibiotics. It is assumed that the same physiology underlies survival of individual tolerant and persistent bacteria. However, by comparing tolerance and persistence during Salmonella Typhimurium infection, we reveal that these two phenomena are underpinned by different bacterial physiologies. Multidrug-tolerant mutant Salmonella enter a near-dormant state protected from immune-mediated genotoxic damages. However, the numerous tolerant cells, optimized for survival, lack the capabilities necessary to initiate infection relapse following antibiotic withdrawal. In contrast, persisters retain an active state. This leaves them vulnerable to accumulation of macrophage-induced dsDNA breaks but concurrently confers the versatility to initiate infection relapse if protected by RecA-mediated DNA repair. Accordingly, recurrent, invasive, non-typhoidal Salmonella clinical isolates display hallmarks of persistence rather than tolerance during antibiotic treatment. Our study highlights the complex trade-off that antibiotic-recalcitrant Salmonella balance to act as a reservoir for infection relapse.

Spectroscopic label-free microscopy of changes in live cell chromatin and biochemical composition in transplantable organoids.

Organoids formed from human induced pluripotent stem cells (hiPSCs) could be a limitless source of functional tissue for transplantations in many organs. Unfortunately, fine-tuning differentiation protocols to form large quantities of hiPSC organoids in a controlled, scalable, and reproducible manner is quite difficult and often takes a very long time. Recently, we introduced a new approach of rapid organoid formation from dissociated hiPSCs and endothelial cells using microfabricated cell-repellent microwell arrays. This approach, when combined with real-time label-free Raman spectroscopy of biochemical composition changes and confocal light scattering spectroscopic microscopy of chromatin transition, allows for monitoring live differentiating organoids without the need to sacrifice a sample, substantially shortening the time of protocol fine-tuning. We used this approach to both culture and monitor homogeneous liver organoids that have the main functional features of the human liver and which could be used for cell transplantation liver therapy in humans.

Generation of fully functional hepatocyte-like organoids from human induced pluripotent stem cells mixed with Endothelial Cells.

Despite advances in stem cell research, cell transplantation therapy for liver failure is impeded by a shortage of human primary hepatocytes (HPH), along with current differentiation protocol limitations. Several studies have examined the concept of co-culture of human induced pluripotent cells (hiPSCs) with various types of supporting non-parenchymal cells to attain a higher differentiation yield and to improve hepatocyte-like cell functions both in vitro and in vivo. Co-culturing hiPSCs with human endothelial cells (hECs) is a relatively new technique that requires more detailed studies. Using our 3D human embryoid bodies (hEBs) formation technology, we interlaced Human Adipose Microvascular Endothelial Cells (HAMEC) with hiPSCs, leading to a higher differentiation yield and notable improvements across a wide range of hepatic functions. We conducted a comprehensive gene and protein secretion analysis of our HLCs coagulation factors profile, showing promising results in comparison with HPH. Furthermore, a stage-specific glycomic analysis revealed that the differentiated hepatocyte-like clusters (HLCs) resemble the glycan features of a mature tissue rather than cells in culture. We tested our HLCs in animal models, where the presence of HAMEC in the clusters showed a consistently better performance compared to the hiPSCs only group in regard to persistent albumin secretion post-transplantation.

Salmonella persisters undermine host immune defenses during antibiotic treatment.

Many bacterial infections are hard to treat and tend to relapse, possibly due to the presence of antibiotic-tolerant persisters. In vitro, persister cells appear to be dormant. After uptake of Salmonella species by macrophages, nongrowing persisters also occur, but their physiological state is poorly understood. In this work, we show that Salmonella persisters arising during macrophage infection maintain a metabolically active state. Persisters reprogram macrophages by means of effectors secreted by the Salmonella pathogenicity island 2 type 3 secretion system. These effectors dampened proinflammatory innate immune responses and induced anti-inflammatory macrophage polarization. Such reprogramming allowed nongrowing Salmonella cells to survive for extended periods in their host. Persisters undermining host immune defenses might confer an advantage to the pathogen during relapse once antibiotic pressure is relieved.

Fatigue, Pain, and Other Physical Symptoms of Living Liver Donors in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study.

Little is known about living liver donors' perceptions of their physical well-being following the procedure. We collected data on donor fatigue, pain, and other relevant physical outcomes as part of the prospective, multicenter Adult-to-Adult Living Donor Liver Transplantation Cohort Study consortium. A total of 271 (91%) of 297 eligible donors were interviewed at least once before donation and 3, 6, 12, and 24 months after donation using validated measures when available. Repeated measures regression models were used to identify potential predictors of worse physical outcomes. We found that donors reported more fatigue immediately after surgery that improved by 2 years after donation, but not to predonation levels. A similar pattern was seen across a number of other physical outcomes. Abdominal or back pain and interference from their pain were rated relatively low on average at all study points. However, 21% of donors did report clinically significant pain at some point during postdonation study follow-up. Across multiple outcomes, female donors, donors whose recipients died, donors with longer hospital stays after surgery, and those whose families discouraged donation were at risk for worse physical well-being outcomes. In conclusion, although not readily modifiable, we have identified risk factors that may help identify donors at risk for worse physical outcomes for targeted intervention. Liver Transplantation 00 000-000 2018 AASLD.

Posttransplant Lymphoproliferative Disorder Isolated to the Adrenal Gland in a Liver Transplant Patient.

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication that accounts for up to 20% of malignancies after solid organ transplantation. We describe a rare case of isolated PTLD in the adrenal gland occurring 7 months after liver transplant in a patient who developed a primary Epstein-Barr virus infection. He was treated with rituximab and his immunosuppression regimen was minimized. We review the incidence, pathogenesis, presentation, and management of PTLD in the liver-transplant population. Our case highlights the variation in the presentation of PTLD and the importance of a high index of suspicion among the at-risk group.

Prevalence and Predictors of Patient-Reported Long-term Mental and Physical Health After Donation in the Adult-to-Adult Living-Donor Liver Transplantation Cohort Study.

BACKGROUND: Prospective and longitudinal studies have examined liver donors' medical outcomes beyond the first 1 to 2 years postdonation. There is no analogous longitudinal evidence on long-term psychosocial outcomes, including patient-reported clinically significant mental health problems and perceptions of physical well-being. We examined prevalence, descriptive characteristics, and predictors of diagnosable mental health conditions and self-reported physical health problems, including fatigue and pain, in the long-term years after liver donation. METHODS: Donors from 9 centers who initially completed telephone interviews at 3 to 10 years postdonation (mean, 5.8 years; SD, 1.9) were reinterviewed annually for 2 years using validated measures. Outcomes were examined descriptively. Repeated-measures regression analyses evaluated potential predictors and correlates of outcomes. RESULTS: Of 517 donors initially interviewed (66% of those eligible), 424 (82%) were reassessed at least once. Prevalence rates of major depression and clinically significant pain were similar to general population norms; average fatigue levels were better than norms. All prevalence rates showed little temporal change. Anxiety and alcohol use disorder rates exceeded normative rates at 1 or more assessments. Longer postdonation hospitalization, female sex, higher body mass index, concerns about donation-related health effects, and burdensome donation-related financial costs were associated with increased risk for most outcomes (P's < 0.05). Men were at higher risk for alcohol use disorder (P < 0.001). CONCLUSIONS: Anxiety and alcohol use disorders were more common than would be expected; they may warrant increased research attention and clinical surveillance. Surveillance for long-term problems in the areas assessed may be optimized by targeting donors at higher risk based on identified predictors and correlates.

Surgical Management of Gallbladder Cancer: Simple Versus Extended Cholecystectomy and the Role of Adjuvant Therapy.

OBJECTIVE: To assess if simple cholecystectomy with adjuvant therapy could provide outcomes comparable to extended cholecystectomy. BACKGROUND: Current guidelines recommend extended/radical cholecystectomy for T2/T3 gallbladder cancer; however, many tumors are discovered incidentally at laparoscopic cholecystectomy. METHODS: The national Cancer Data Base 2004 to 2014 was queried for patients with pT2/T3 gallbladder adenocarcinoma who underwent resection. Adjuvant therapy was defined as chemotherapy, with or without radiotherapy, within 90 days of surgery. Baseline characteristics and overall survival were compared by χ and Kaplan-Meier method, respectively. One-to-one propensity score matching for receipt of adjuvant therapy was used to account for potential selection bias. RESULTS: A total of 6825 patients were identified. Diagnosis was made predominantly (78.9%) at the time of surgery or on pathology; 31.8% (2168) received adjuvant therapy. The majority, 88.8% (6060), had a simple cholecystectomy. Patients who received adjuvant therapy versus surgery alone were more likely to: be younger, privately insured, have no comorbidities, pT3 disease, positive lymph nodes, positive resection margins, and extended cholecystectomy. After matching, median survival was significantly longer for extended cholecystectomy with adjuvant therapy (23.3 months) than cholecystectomy with adjuvant therapy (16.4 months), which was significantly longer than either simple (12.4 months) or extended (10.7 months) cholecystectomy alone (all log-rank P<0.001). CONCLUSIONS: Adjuvant therapy prolongs survival after resection of T2/T3 tumors. Simple cholecystectomy with adjuvant therapy appears to be superior to extended resection alone in the short term and may serve as a potential alternative to re-resection in select high-risk individuals.

Hepatic Hemodynamics and Portal Flow Modulation: The A2ALL Experience.

OBJECTIVE: A principal aim of the Adult-to-Adult Living Donor Liver Transplantation Cohort Study was to study hepatic blood flow and effect of portal flow modulation on graft outcomes in the setting of increasing use of smaller and left lobe grafts. METHODS: Recipients of 274 living donor liver transplant were enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study, including 233 (85.0%) right lobes, 40 (14.6%) left lobes, and 1 (0.5%) left lateral section. Hepatic hemodynamics were recorded after reperfusion. A total of 57 portal flow modulations were performed on 52 subjects. RESULTS: Modulation lowered portal pressure in 68% of subjects with inconsistent effects on hepatic arterial and portal flow. A higher rate of graft dysfunction was observed in modulated vs. unmodulated subjects (31% vs. 18%; P = 0.03); however, graft survival in modulated subjects was not different from unmodulated subjects at 3 years. CONCLUSIONS: These results suggest the need for a study using a prespecified portal flow modulation protocol with defined indications to better define the effects of these interventions.

Persistent bacterial infections and persister cells.

Many bacteria can infect and persist inside their hosts for long periods of time. This can be due to immunosuppression of the host, immune evasion by the pathogen and/or ineffective killing by antibiotics. Bacteria can survive antibiotic treatment if they are resistant or tolerant to a drug. Persisters are a subpopulation of transiently antibiotic-tolerant bacterial cells that are often slow-growing or growth-arrested, and are able to resume growth after a lethal stress. The formation of persister cells establishes phenotypic heterogeneity within a bacterial population and has been hypothesized to be important for increasing the chances of successfully adapting to environmental change. The presence of persister cells can result in the recalcitrance and relapse of persistent bacterial infections, and it has been linked to an increase in the risk of the emergence of antibiotic resistance during treatment. If the mechanisms of the formation and regrowth of these antibiotic-tolerant cells were better understood, it could lead to the development of new approaches for the eradication of persistent bacterial infections. In this Review, we discuss recent developments in our understanding of bacterial persisters and their potential implications for the treatment of persistent infections.

Living donor liver transplantation: eliminating the wait for death in end-stage liver disease?

Adult-to-adult living donor liver transplantation (A2ALDLT), outside of Asia, remains an important yet underutilized gift of life. For patients with end-stage liver disease, A2ALDLT is a proven transplantation option, with lower waiting list mortality and suffering, and equivalent or better allograft and patient survival than deceased-donor liver transplantation (DDLT). The risks to living donors and the benefit to their recipients have been carefully defined with long-term level 1 and 2 evidence-based study. An overview of the development and practice of living donor liver transplant (LDLT), including donor and recipient surgical allograft innovation, is provided. The issues of recipient selection, outcomes and morbidity, including disease-variable study and challenges past and present are presented in comparison with DDLT cohorts, and future insights are described. Central to practice is the careful and concise review of donor evaluation and selection and donor outcome, morbidity, quality of life and present and future strategies for donor advocacy and growth of the technique.

Scalable Differentiation of Human iPSCs in a Multicellular Spheroid-based 3D Culture into Hepatocyte-like Cells through Direct Wnt/ß-catenin Pathway Inhibition.

Treatment of acute liver failure by cell transplantation is hindered by a shortage of human hepatocytes. Current protocols for hepatic differentiation of human induced pluripotent stem cells (hiPSCs) result in low yields, cellular heterogeneity, and limited scalability. In the present study, we have developed a novel multicellular spheroid-based hepatic differentiation protocol starting from embryoid bodies of hiPSCs (hiPSC-EBs) for robust mass production of human hepatocyte-like cells (HLCs) using two novel inhibitors of the Wnt pathway. The resultant hiPSC-EB-HLCs expressed liver-specific genes, secreted hepatic proteins such as Albumin, Alpha Fetoprotein, and Fibrinogen, metabolized ammonia, and displayed cytochrome P450 activities and functional activities typical of mature primary hepatocytes, such as LDL storage and uptake, ICG uptake and release, and glycogen storage. Cell transplantation of hiPSC-EB-HLC in a rat model of acute liver failure significantly prolonged the mean survival time and resolved the liver injury when compared to the no-transplantation control animals. The transplanted hiPSC-EB-HLCs secreted human albumin into the host plasma throughout the examination period (2 weeks). Transplantation successfully bridged the animals through the critical period for survival after acute liver failure, providing promising clues of integration and full in vivo functionality of these cells after treatment with WIF-1 and DKK-1.

Early Postoperative Pain and its Predictors in the Adult to Adult Living Donor Liver Transplantation Cohort Study.

BACKGROUND: Little is known about how well postoperative pain is managed in living liver donors, despite pain severity being the strongest predictor of persistent pain with long-lasting disability. METHODS: We conducted a prospective multicenter study of 172 living liver donors. Self-reported outcomes for pain severity, activity interference, affective (emotional) reactions, adverse effects to treatment, and perceptions of care were collected using the American Pain Society Patient Outcomes Questionnaire-Revised. Mixed-effects linear regression was used to identify demographic and psychosocial predictors of subscale scores. RESULTS: Donors were young (36.8 ± 10.6) and healthy. Of 12 expert society analgesic recommendations for postoperative pain management, 49% received care conforming to 3 guidelines, and only 9% to 4 or 5. More than half reported adverse effects to analgesic treatment for moderate to severe pain that interfered with functional activity; however, emotional distress to pain was unexpectedly minimal. Female donors had higher affective (ß = 0.88, P = 0.005) and adverse effects scores (ß = 1.33, P < 0.001). Donors with 2 or more medical concerns before surgery averaged 1 unit higher pain severity, functional interference, adverse effects, and affective reaction subscale scores (ß range 1.06-1.55, all P < 0.05). Receiving information about pain treatment options increased perception of care subscale scores (ß = 1.24, P = 0.001), whereas depressive symptoms before donation were associated with lower scores (ß = -1.58, P = 0.01). CONCLUSIONS: Donors have a distinct profile of pain reporting that is highly influenced by psychological characteristics. Interventions to improve pain control should consider modifying donor behavioral characteristics in addition to optimizing pain care protocols.

Patterns of Early Allograft Dysfunction in Adult Live Donor Liver Transplantation: The A2ALL Experience.

BACKGROUND: Early allograft dysfunction (EAD) after living donor liver transplantation (LDLT) has often been attributed to inadequate graft size, and termed small-for-size syndrome. Early allograft dysfunction definitions include a variable constellation of findings, including hyperbilirubinemia, coagulopathy, encephalopathy, and ascites formation. Among putative causes of EAD after LDLT are excessive portal pressure and/or flow. Our objective was to evaluate patterns of EAD after LDLT. METHODS: In this study, 631 LDLT recipients were monitored for complications, EAD (defined by postoperative day 7 bilirubin >10 mg/dL or international normalized ratio >1.6), and graft failure. Approximately 200 had portal venous and arterial pressure and flow measurements before and after LDLT. Portal inflow modification (splenic artery ligation, hemiportocaval shunt, or splenectomy) was performed at the discretion of the operating surgeon. Associations between EAD and recipient, donor, and transplant factors were examined using multivariable logistic regression. RESULTS: Risk of EAD was associated with left lobe grafts, lower graft weight among left lobes, higher preoperative bilirubin, higher portal reperfusion pressure, higher donor age, and higher donor body mass index. The risk of graft loss within the first 90 days was 5.2 times higher for recipients with EAD versus those without EAD (P < 0.001). CONCLUSIONS: Early allograft dysfunction can be defined using postoperative day 7 laboratory values that are highly predictive of early graft failure within 90 days. Risk factors associated with EAD after LDLT include: graft type and size, preoperative bilirubin, portal reperfusion pressure, donor age, and donor body mass index.