Retransplantation outcomes for hepatitis C in the United States before and after direct-acting antiviral introduction.

The success of direct-acting antiviral (DAA) therapy has led to near-universal cure for patients chronically infected with hepatitis C virus (HCV) and improved post-liver transplant (LT) outcomes. We investigated the trends and outcomes of retransplantation in HCV and non-HCV patients before and after the introduction of DAA. Adult patients who underwent re-LT were identified in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Multiorgan transplants and patients with >2 total LTs were excluded. Two eras were defined: pre-DAA (2009-2012) and post-DAA (2014-2017). A total of 2112 re-LT patients were eligible (HCV: n = 499 pre-DAA and n = 322 post-DAA; non-HCV: n = 547 pre-DAA and n = 744 post-DAA). HCV patients had both improved graft and patient survival after re-LT in the post-DAA era. One-year graft survival was 69.8% pre-DAA and 83.8% post-DAA (P < .001). One-year patient survival was 73.1% pre-DAA and 86.2% post-DAA (P < .001). Graft and patient survival was similar between eras for non-HCV patients. When adjusted, the post-DAA era represented an independent positive predictive factor for graft and patient survival (hazard ratio [HR]: 0.67; P = .005, and HR: 0.65; P = .004) only in HCV patients. The positive post-DAA era effect was observed only in HCV patients with first graft loss due to disease recurrence (HR: 0.31; P = .002, HR 0.32; P = .003, respectively). Among HCV patients, receiving a re-LT in the post-DAA era was associated with improved patient and graft survival.

Short recipient warm ischemia time improves outcomes in deceased donor liver transplantation.

While adverse effects of prolonged recipient warm ischemia time (rWIT) in liver transplantation (LT) have been well investigated, few studies have focused on possible positive prognostic effects of short rWIT. We aim to investigate if shortening rWIT can further improve outcomes in donation after brain death liver transplant (DBD-LT). Primary DBD-LT between 2000 and 2019 were retrospectively reviewed. Patients were divided according to rWIT (≤30, 31-40, 41-50, and >50 min). The requirement of intraoperative transfusion, early allograft dysfunction (EAD), and graft survival were compared between the rWIT groups. A total of 1,256 patients of DBD-LTs were eligible. rWIT was ≤30min in 203 patients (15.7%), 31-40min in 465 patients (37.3%), 41-50min in 353 patients (28.1%), and >50min in 240 patients (19.1%). There were significant increasing trends of transfusion requirement (P < 0.001) and increased estimated blood loss (EBL, P < 0.001), and higher lactate level (P < 0.001) with prolongation of rWIT. Multivariable logistic regression demonstrated the lowest risk of EAD in the WIT ≤30min group. After risk adjustment, patients with rWIT ≤30 min showed a significantly lower risk of graft loss at 1 and 5-years, compared to other groups. The positive prognostic impact of rWIT ≤30min was more prominent when cold ischemia time exceeded 6 h. In conclusion, shorter rWIT in DBD-LT provided significantly better post-transplant outcomes.

Muscle-specific Pikfyve gene disruption causes glucose intolerance, insulin resistance, adiposity, and hyperinsulinemia but not muscle fiber-type switching.

The evolutionarily conserved kinase PIKfyve that synthesizes PtdIns5P and PtdIns(3,5)P2 has been implicated in insulin-regulated GLUT4 translocation/glucose entry in 3T3-L1 adipocytes. To decipher PIKfyve's role in muscle and systemic glucose metabolism, here we have developed a novel mouse model with Pikfyve gene disruption in striated muscle (MPIfKO). These mice exhibited systemic glucose intolerance and insulin resistance at an early age but had unaltered muscle mass or proportion of slow/fast-twitch muscle fibers. Insulin stimulation of in vivo or ex vivo glucose uptake and GLUT4 surface translocation was severely blunted in skeletal muscle. These changes were associated with premature attenuation of Akt phosphorylation in response to in vivo insulin, as tested in young mice. Starting at 10-11 wk of age, MPIfKO mice progressively accumulated greater body weight and fat mass. Despite increased adiposity, serum free fatty acid and triglyceride levels were normal until adulthood. Together with the undetectable lipid accumulation in liver, these data suggest that lipotoxicity and muscle fiber switching do not contribute to muscle insulin resistance in MPIfKO mice. Furthermore, the 80% increase in total fat mass resulted from increased fat cell size rather than altered fat cell number. The observed profound hyperinsulinemia combined with the documented increases in constitutive Akt activation, in vivo glucose uptake, and gene expression of key enzymes for fatty acid biosynthesis in MPIfKO fat tissue suggest that the latter is being sensitized for de novo lipid anabolism. Our data provide the first in vivo evidence that PIKfyve is essential for systemic glucose homeostasis and insulin-regulated glucose uptake/GLUT4 translocation in skeletal muscle.

Functional dissociation between PIKfyve-synthesized PtdIns5P and PtdIns(3,5)P2 by means of the PIKfyve inhibitor YM201636.

PIKfyve is an essential mammalian lipid kinase with pleiotropic cellular functions whose genetic knockout in mice leads to preimplantation lethality. Despite several reports for PIKfyve-catalyzed synthesis of phosphatidylinositol 5-phosphate (PtdIns5P) along with phosphatidylinositol-3,5-biphosphate [PtdIns(3,5)P(2)] in vitro and in vivo, the role of the PIKfyve pathway in intracellular PtdIns5P production remains underappreciated and the function of the PIKfyve-synthesized PtdIns5P pool poorly characterized. Hence, the recently discovered potent PIKfyve-selective inhibitor, the YM201636 compound, has been solely tested for inhibiting PtdIns(3,5)P(2) synthesis. Here, we have compared the in vitro and in vivo inhibitory potency of YM201636 toward PtdIns5P and PtdIns(3,5)P(2). Unexpectedly, we observed that at low doses (10-25 nM), YM201636 inhibited preferentially PtdIns5P rather than PtdIns(3,5)P(2) production in vitro, whereas at higher doses, the two products were similarly inhibited. In cellular contexts, YM201636 at 160 nM inhibited PtdIns5P synthesis twice more effectively compared with PtdIns(3,5)P(2) synthesis. In 3T3L1 adipocytes, human embryonic kidney 293 and Chinese hamster ovary (CHO-T) cells, levels of PtdIns5P dropped by 62-71% of the corresponding untreated controls, whereas those of PtdIns(3,5)P(2) fell by only 28-46%. The preferential inhibition of PtdIns5P versus PtdIns(3,5)P(2) at low doses of YM201636 was explored to probe contributions of the PIKfyve-catalyzed PtdIns5P pool to insulin-induced actin stress fiber disassembly in CHO-T cells, GLUT4 translocation in 3T3L1 adipocytes, and induction of aberrant cellular vacuolation in these or other cell types. The results provide the first experimental evidence that the principal pathway for PtdIns5P intracellular production is through PIKfyve and that insulin effect on actin stress fiber disassembly is mediated entirely by the PIKfyve-produced PtdIns5P pool.

The phosphoinositide kinase PIKfyve is vital in early embryonic development: preimplantation lethality of PIKfyve-/- embryos but normality of PIKfyve+/- mice.

Gene mutations in the phosphoinositide-metabolizing enzymes are linked to various human diseases. In mammals, PIKfyve synthesizes PtdIns(3,5)P(2) and PtdIns5P lipids that regulate endosomal trafficking and responses to extracellular stimuli. The consequence of pikfyve gene ablation in mammals is unknown. To clarify the importance of PIKfyve and PIKfyve lipid products, in this study, we have characterized the first mouse model with global deletion of the pikfyve gene using the Cre-loxP approach. We report that nearly all PIKfyve(KO/KO) mutant embryos died before the 32-64-cell stage. Cultured fibroblasts derived from PIKfyve(flox/flox) embryos and rendered pikfyve-null by Cre recombinase expression displayed severely reduced DNA synthesis, consistent with impaired cell division causing early embryo lethality. The heterozygous PIKfyve(WT/KO) mice were born at the expected Mendelian ratio and developed into adulthood. PIKfyve(WT/KO) mice were ostensibly normal by several other in vivo, ex vivo, and in vitro criteria despite the fact that their levels of the PIKfyve protein and in vitro enzymatic activity in cells and tissues were 50-55% lower than those of wild-type mice. Consistently, steady-state levels of the PIKfyve products PtdIns(3,5)P(2) and PtdIns5P selectively decreased, but this reduction (35-40%) was 10-15% less than that expected based on PIKfyve protein reduction. The nonlinear decrease of the PIKfyve protein versus PIKfyve lipid products, the potential mechanism(s) discussed herein, may explain how one functional allele in PIKfyve(WT/KO) mice is able to support the demands for PtdIns(3,5)P(2)/PtdIns5P synthesis during life. Our data also shed light on the known human disorder linked to PIKFYVE mutations.

ArPIKfyve regulates Sac3 protein abundance and turnover: disruption of the mechanism by Sac3I41T mutation causing Charcot-Marie-Tooth 4J disorder.

The mammalian phosphatidylinositol (3,5)-bisphosphate (PtdIns(3,5)P(2)) phosphatase Sac3 and ArPIKfyve, the associated regulator of the PtdIns3P-5 kinase PIKfyve, form a stable binary complex that associates with PIKfyve in a ternary complex to increase PtdIns(3,5)P(2) production. Whether the ArPIKfyve-Sac3 subcomplex functions outside the PIKfyve context is unknown. Here we show that stable or transient expression of ArPIKfyve(WT) in mammalian cells elevates steady-state protein levels and the PtdIns(3,5)P(2)-hydrolyzing activity of Sac3, whereas knockdown of ArPIKfyve has the opposite effect. These manipulations do not alter the Sac3 mRNA levels, suggesting that ArPIKfyve might control Sac3 protein degradation. Inhibition of protein synthesis in COS cells by cycloheximide reveals remarkably rapid turnover of expressed Sac3(WT) (t((1/2)) = 18.8 min), resulting from a proteasome-dependent clearance as evidenced by the extended Sac3(WT) half-life upon inhibiting proteasome activity. Coexpression of ArPIKfyve(WT), but not the N- or C-terminal halves, prolongs the Sac3(WT) half-life consistent with enhanced Sac3 protein stability through association with full-length ArPIKfyve. We further demonstrate that mutant Sac3, harboring the pathogenic Ile-to-Thr substitution at position 41 found in patients with CMT4J disorder, is similar to Sac3(WT) with regard to PtdIns(3,5)P(2)-hydrolyzing activity, association with ArPIKfyve, or rapid proteasome-dependent clearance. Remarkably, however, neither is the steady-state Sac3(I41T) elevated nor is the Sac3(I41T) half-life extended by coexpressed ArPIKfyve(WT), indicating that unlike with Sac3(WT), ArPIKfyve fails to prevent Sac3(I41T) rapid loss. Together, our data indentify a novel regulatory mechanism whereby ArPIKfyve enhances Sac3 abundance by attenuating Sac3 proteasome-dependent degradation and suggest that a failure of this mechanism could be the primary molecular defect in the pathogenesis of CMT4J.

Surgical resection of rare internal jugular vein aneurysm in neurofibromatosis type 1.

Neurofibromatosis type 1 is a congenital condition affecting neurons and connective tissue integrity including vasculature. On extremely rare occasions these patients present with venous aneurysms affecting the internal jugular vein. If they become large enough there presents a risk of rupture, thrombosis, embolization or compression of adjacent structures. In these circumstances, or when the patient becomes symptomatic, surgical exploration is warranted. We present a case of one of the largest aneurysms in the literature and one of only five associated with Neurofibromatosis type 1. A 63-year-old female who initially presented for a Hinchey III diverticulitis requiring laparotomy developed an incidentally discovered left neck swelling prior to discharge. After nonspecific clinical exam findings, imaging identified a thrombosed internal jugular vein aneurysm. Due to the risks associated with the particularly large size of our patient's aneurysm, our patient underwent surgical exploration with ligation and excision. Although several techniques have been reported, for similar presentations, we recommend this technique.

Successful surgical excision of a massive symptomatic partially obstructing Brunner's gland hamartoma: a case report.

Brunner gland function within the duodenal epithelium is secretion of alkaline mucin to counteract acidic chyme. These glands may grow beyond the duodenal wall to become hamartomas. Rarely, they become large enough to cause obstructive symptoms in the upper gastrointestinal tract. We report a case of one of the largest lesions identified in the literature causing obstruction symptoms. A previously asymptomatic 65-year-old gentleman presented to the emergency department with a single-day history of colicky abdominal pain, cramping and vomiting. After initial imaging with computed tomography was inconclusive, a subsequent esophagogastroduodenoscopy with biopsy and small bowel series was performed indicating a pedunculated polypoid mass. Our patient underwent an uncomplicated exploratory laparotomy with duodenotomy and Heineke-Mikulicz pyloroplasty for resection of a massive Brunner's gland hamartoma. For similar presentations, we recommend this technique.

Unexpected severe consequences of Pikfyve deletion by aP2- or Aq-promoter-driven Cre expression for glucose homeostasis and mammary gland development.

Systemic deficiency of PIKfyve, the evolutionarily conserved phosphoinositide kinase synthesizing cellular PtdIns5P and PtdIns(3,5)P2 and implicated in insulin signaling, causes early embryonic death in mice. In contrast, mice with muscle-specific Pikfyve disruption have normal lifespan but exhibit early-age whole-body glucose intolerance and muscle insulin resistance, thus establishing the key role of muscle PIKfyve in glucose homeostasis. Fat and muscle tissues control postprandial glucose clearance through different mechanisms, raising questions as to whether adipose Pikfyve disruption will also trigger whole-body metabolic abnormalities, and if so, what the mechanism might be. To clarify these issues, here we have characterized two new mouse models with adipose tissue disruption of Pikfyve through Cre recombinase expression driven by adipose-specific aP2- or adiponectin (Aq) promoters. Whereas both mouse lines were ostensibly normal until adulthood, their glucose homeostasis and systemic insulin sensitivity were severely dysregulated. These abnormalities stemmed in part from accelerated fat-cell lipolysis and elevated serum FFA Intriguingly, aP2-Cre-PIKfyve(fl/fl) but not Aq-Cre-PIKfyve(fl/fl) females had severely impaired pregnancy-induced mammary gland differentiation and lactogenesis, consistent with aP2-Cre-mediated Pikfyve excision in nonadipogenic tissues underlying this defect. Intriguingly, whereas mammary glands from postpartum control and Aq-Cre-PIKfyve(fl/fl) mice or ex vivo mammary gland explants showed profound upregulation of PIKfyve protein levels subsequent to prolactin receptor activation, such increases were not apparent in aP2-Cre-PIKfyve(fl/fl) females. Collectively, our data identify for the first time that adipose tissue Pikfyve plays a key role in the mechanisms regulating glucose homeostasis and that the PIKfyve pathway is critical in mammary epithelial differentiation during pregnancy and lactogenesis downstream of prolactin receptor signaling.

Accreditation Council for Graduate Medical Education Compliance and Resident Competence in Hepatopancreaticobiliary Surgery during General Surgery Residency: A Program Director Review.

OBJECTIVE: A survey of general surgery (GS) program directors (PD) was performed to determine how Accreditation Council for Graduate Medical Education (ACGME) hepatopancreatobiliary (HPB) requirements are met and compare the findings with previous national averages. The objectives were to establish whether GS residencies are in compliance with ACGME recommendations. Secondary objectives aimed to determine if fellowship affects residency training. METHODS: A 30-question survey was sent out to GS PDs registered with Association of Program Directors in Surgery. Analysis of the responses was then completed using statistical software (GraphPad) and compared with the ACGME data. RESULTS: Although HPB training and exposure has changed, most programs continue to meet HPB requirements at their main institution (73%). Overall, 27% of PDs now send residents to outside facilities or have hired new HPB faculty to manage the shift in caseload. GS graduates have HPB numbers comparable to the national resident averages of 2010 to 2011, and many programs graduate residents exceeding ACGME HPB requirements. Although 69% of residents complete >50% of HPB cases, only 50% of PDs felt residents were competent. Altogether, 30% of programs had HPB fellowships; few PDs felt fellows positively affected residency training. CONCLUSIONS: PDs feel that residents achieve more than minimum required HPB numbers required by the ACGME but not all are competent. Fellows reduce resident exposure to HPB cases. More simulation and autonomy may improve HPB education in GS residency.