Percutaneous Cholecystostomy in Acute Cholecystitis-Predictors of Recurrence and Interval Cholecystectomy.

BACKGROUND: Percutaneous cholecystostomy (PC) tube is a preferred option in acute cholecystitis for patients who are high risk for cholecystectomy (CCY). There are no evidence-based guidelines for patient care after PC. We identified the predictors of disease recurrence and successful interval CCY. METHODS: A retrospective review of 145 PC patients between 2008 and 2016 at a tertiary hospital was performed. Primary outcomes included mortality, readmissions, hospital and intensive care unit length of stay (LOS), disease recurrence, and interval CCY. RESULTS: There were 96 (67%) calculous and 47 (33%) acalculous cholecystitis cases. Seventy-two (49%) had chronic and 73 (51%) had acute prohibitive risks as an indication for PC. There were 54 (37%) periprocedural complications, which most commonly were dislodgements. Twenty-six (18%) patients had a recurrence at a median time of 65 days. Calculous cholecystitis (odds ratio [OR] 3.44, P = 0.038) and purulence in the gallbladder (OR 3.77, P = 0.009) were predictors for recurrence. Forty-one (28%) patients underwent interval CCY. Patients with acute illness were likely to undergo interval CCY (OR 6.67, P = 0.0002). Patients with acalculous cholecystitis had longer hospital LOS (16 versus 8 days) and intensive care unit LOS (2 versus 0 days), and higher readmission rates (OR 2.42, P = 0.02). Thirty-day mortality after PC placement was 9%. Patients receiving interval CCY were noted to have increased survival compared to PC alone. However, this should not be attributed to interval CCY alone in absence of randomization in this study. CONCLUSIONS: Calculous cholecystitis and purulence in the gallbladder are independent predictors of acute cholecystitis recurrence. Acute illness is a strong predictor of successful interval CCY. The association of interval CCY and prolonged survival in patients with PC as noted in this study should be further assessed in future prospective randomized trials.

c-Met is a marker of pancreatic cancer stem cells and therapeutic target.

BACKGROUND & AIMS: Growth of many different tumor types requires a population of self-renewing cancer stem cells (CSCs). c-Met is a marker of normal mouse pancreatic stem and progenitor cells; we investigated whether it is also a marker of human pancreatic CSCs that might be developed as a therapeutic target. METHODS: We studied growth of primary human pancreatic adenocarcinoma in NOD SCID mice. The self-renewal capability of pancreatic cancer cells that expressed high levels of c-Met (c-Met(high)) was assessed using in vitro sphere assays and compared with those that were c-Met negative or expressed low levels of c-Met. The tumorigenicity of c-Met(high) pancreatic cancer cells was evaluated in NOD SCID mice. RESULTS: c-Met(high) cells readily formed spheres, whereas c-Met-negative cells did not. Use of the c-Met inhibitor XL184 or c-Met knockdown with small hairpin RNAs significantly inhibited tumor sphere formation. c-Met(high) cells had increased tumorigenic potential in mice; those that expressed c-Met and CD44 (0.5%-5% of the pancreatic cancer cells) had the capability for self-renewal and the highest tumorigenic potential of all cell populations studied. In pancreatic tumors established in NOD SCID mice, c-Met inhibitors slowed tumor growth and reduced the population of CSCs when given alone or in combination with gemcitabine. Administration of XL184 for 2 weeks after cardiac injection of cancer cells prevented the development of metastases. CONCLUSIONS: c-Met is a new marker for pancreatic CSCs. It is required for growth and metastasis of pancreatic tumors in mice and is a therapeutic target for pancreatic cancer.

American College of Surgeons' Committee on Trauma Performance Improvement and Patient Safety program: maximal impact in a mature trauma center.

BACKGROUND: To examine the impact of an ongoing comprehensive performance improvement and patient safety (PIPS) program implemented in 2005 on mortality outcomes for trauma patients at an established American College of Surgeons (ACS)-verified Level I Trauma Center. METHODS: The primary outcome measure was in-hospital mortality. Age, Injury Severity Score (ISS), and intensive care unit admissions were used as stratifying variables to examine outcomes over a 5-year period (2004-2008). Institution mortality rates were compared with the National Trauma Data Bank mortality rates stratified by ISS score. Enhancements to our comprehensive PIPS program included revision of trauma activation criteria, development of standardized protocols for initial resuscitation, massive transfusion, avoidance of over-resuscitation, tourniquet use, pelvic fracture management, emphasis on timely angiographic and surgical intervention, prompt spine clearance, reduction in time to computed tomography imaging, reduced dwell time in emergency department, evidence-based traumatic brain injury management, and multidisciplinary efforts to reduce healthcare-associated infections. RESULTS: In 2004 (baseline data), the in-hospital mortality rate for the most severely injured trauma patients (ISS >24) at our trauma center was 30%, consistent with the reported mortality rate from the National Trauma Data Bank for patients with this severity of injury. Over 5 years, our mortality rate decreased significantly for severely injured patients with an ISS >24, from 30.1% (2004) to 18.3% (2008), representing a 12% absolute reduction in mortality (p = 0.011). During the same 5-year time period, the proportion of elderly patients (age >65 years) cared for at our trauma center increased from 23.5% in 2004 to 30.6% in 2008 (p = 0.0002). Class I trauma activations increased significantly from 5.5% in 2004 to 15.5% in 2008 based on our reclassification. A greater percentage of patients were admitted to the intensive care unit (25.8% in 2004 to 37.3% in 2007 and 30.4% in 2008). No difference was identified in the rate of blunt (95%) or penetrating (5%) mechanism of injury in our patients over this time period. Trauma Quality Improvement Program confirmed improved trauma outcomes with observed-to-expected ratio and 95% confidence intervals of 0.64 (0.42-0.86) for all patients, 0.54 (0.15-0.91) for blunt single-system patients, and 0.78 (0.51-1.06) for blunt multisystem patients. CONCLUSION: Implementation of a multifaceted trauma PIPS program aimed at improving trauma care significantly reduced in-hospital mortality in a mature ACS Level I trauma center. Optimal care of the injured patient requires uncompromising commitment to PIPS.

The effect of patient code status on surgical resident decision making: A national survey of general surgery residents.

BACKGROUND: Multiple studies have demonstrated that, compared with their full code counterparts, patients with do-not-resuscitate or do-not-intubate status have higher in-hospital and postdischarge mortality than predicted by clinical characteristics alone. We sought to determine whether patient code status affects surgical resident decision making. METHODS: We created an online survey that consisted of 4 vignettes, followed by 10 questions regarding decisions on possible diagnostic and therapeutic interventions. All program directors of Accreditation Council for Graduate Medical Education-accredited general surgery residencies were randomized to receive 1 of 2 survey versions that differed only in the code status of the patients described, with requests to distribute the survey to their residents. Responses to each question were based on a Likert scale. RESULTS: A total of 194 residents completed the survey, 51% of whom were women, and all years of surgical residency were represented. In all vignettes, patient code status influenced perioperative medical decisions, ranging from initiation of dialysis to intensive care unit transfer. In 2 vignettes, it affected decisions to proceed with indicated emergency operations. CONCLUSION: When presented with patient scenarios pertaining to clinical decision making, surgical residents tend to assume that patients with a do-not-resuscitate or do-not-intubate code status would prefer to receive less aggressive care overall. As a result, the delivery of appropriate surgical care may be improperly limited unless a patient's goals of care are explicitly stated. It is important for surgical residents to understand that a do-not-resuscitate or do-not-intubate code status should not be interpreted as a "do-not-treat" status.

Platelet transfusion increases risk for acute respiratory distress syndrome in non-massively transfused blunt trauma patients.

PURPOSE: While damage control resuscitation is known to confer a survival advantage in severely injured patients, high-ratio blood component therapy should be initiated only in carefully selected trauma patients, due to the morbidity associated with blood product use. With this project, we aim to identify the effect of platelet transfusion in non-massively transfused bluntly injured patients. METHODS: The Glue Grant database was retrospectively queried and severely injured blunt trauma patients who underwent non-massive transfusion were identified. Patients were divided into quartiles depending on platelet volume they were transfused in the first 48 h. Outcomes of interest included mortality; ventilator, Intensive Care Unit (ICU) and hospital length of stay (LOS); infectious and non-infectious complications. Multivariable regression models were fitted for these outcomes, controlling for age, pre-existing comorbidities, injury severity, acute physiologic derangement, neurologic injury burden, and other fluid and blood product resuscitation. RESULTS: There was no difference in mortality, LOS, or the incidence of multi-organ failure and infectious complications. However, patients receiving ≥ 250 mL of platelets were more likely to develop acute respiratory distress syndrome (ARDS) compared to those who received < 250 mL [odds ratio 1.91 (95% CI 1.10-3.33, p = 0.022)]. CONCLUSIONS: Pre-emptive platelet transfusion should be avoided in non-massively transfused blunt injury victims in the absence of true or functional thrombocytopenia, as it increases risk for ARDS with no survival benefit.

Selective degradation of AU-rich mRNAs promoted by the p37 AUF1 protein isoform.

An AU-rich element (ARE) consisting of repeated canonical AUUUA motifs confers rapid degradation to many cytokine mRNAs when present in the 3' untranslated region. Destabilization of mRNAs with AREs (ARE-mRNAs) is consistent with the interaction of ARE-binding proteins such as tristetraprolin and the four AUF1 isoforms. However, the association of the AUF1-mRNA interaction with decreased ARE-mRNA stability is correlative and has not been directly tested. We therefore determined whether overexpression of AUF1 isoforms promotes ARE-mRNA destabilization and whether AUF1 isoforms are limiting components for ARE-mRNA decay. We show that the p37 AUF1 isoform and, to a lesser extent, the p40 isoform possess ARE-mRNA-destabilizing activity when overexpressed. Surprisingly, overexpressed p37 AUF1 also destabilized reporter mRNAs containing a noncanonical but AU-rich 3' untranslated region. Since overexpressed p37 AUF1 could interact in vivo with the AU-rich reporter mRNA, AUF1 may be involved in rapid turnover of mRNAs that lack canonical AREs. Moreover, overexpression of p37 AUF1 restored the ability of cells to rapidly degrade ARE-mRNAs when that ability was saturated and inhibited by overexpression of ARE-mRNAs. Finally, activation of ARE-mRNA decay often involves a translation-dependent step, which was eliminated by overexpression of p37 AUF1. These data indicate that the p37 AUF1 isoform and, to some extent, the p40 isoform are limiting factors that facilitate rapid decay of AU-rich mRNAs.

Human thymus mesenchymal stromal cells augment force production in self-organized cardiac tissue.

BACKGROUND: Mesenchymal stromal cells have been recently isolated from thymus gland tissue discarded after surgical procedures. The role of this novel cell type in heart regeneration has yet to be defined. The purpose of this study was to evaluate the therapeutic potential of human thymus-derived mesenchymal stromal cells using self-organized cardiac tissue as an in vitro platform for quantitative assessment. METHODS: Mesenchymal stromal cells were isolated from discarded thymus tissue from neonates undergoing heart surgery and were incubated in differentiation media to demonstrate multipotency. Neonatal rat cardiomyocytes self-organized into cardiac tissue fibers in a custom culture dish either alone or in combination with varying numbers of mesenchymal stromal cells. A transducer measured force generated by spontaneously contracting self-organized cardiac tissue fibers. Work and power outputs were calculated from force tracings. Immunofluorescence was performed to determine the fate of the thymus-derived mesenchymal stromal cells. RESULTS: Mesenchymal stromal cells were successfully isolated from discarded thymus tissue. After incubation in differentiation media, mesenchymal stromal cells attained the expected phenotypes. Although mesenchymal stromal cells did not differentiate into mature cardiomyocytes, addition of these cells increased the rate of fiber formation, force production, and work and power outputs. Self-organized cardiac tissue containing mesenchymal stromal cells acquired a defined microscopic architecture. CONCLUSIONS: Discarded thymus tissue contains mesenchymal stromal cells, which can augment force production and work and power outputs of self-organized cardiac tissue fibers by several-fold. These findings indicate the potential utility of mesenchymal stromal cells in treating heart failure.

Ubiquitin-dependent mechanism regulates rapid turnover of AU-rich cytokine mRNAs.

An AU rich element (ARE) in the 3' noncoding region promotes the rapid degradation of mammalian cytokine and proto-oncogene mRNAs, such as tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor (GM-CSF) and c-fos. Destabilization of ARE-mRNAs involves the association of ARE-binding proteins tristetraprolin or AUF1 and proteasome activity, of which the latter has not been characterized. Here, we show that the stability of a model short-lived mRNA containing the GM-CSF ARE was regulated by the level of ubiquitin-conjugating activity in the cell, which links ARE-mRNA decay to proteasome activity. Increased expression of a cytokine-inducible deubiquitinating protein (DUB) that impairs addition of ubiquitin to proteins fully blocked ARE-mRNA decay, whereas increased expression of a DUB that promotes ubiquitin addition to proteins strongly accelerated ARE-mRNA decay. ARE-mRNA turnover was found to be activated by the ubiquitin-addition reaction and blocked by the ubiquitin-removal reaction. Saturation of the ARE-mRNA decay machinery by high levels of ARE-mRNA, which is well established but not understood, was found to be relieved by increased expression of a DUB that promotes ubiquitin addition to proteins. Finally, inhibition of proteasome activity also blocked accelerated ARE-mRNA decay that is mediated by increased ubiquitin recycling. These results demonstrate that both ubiquitinating activity and proteasome activity are essential for rapid turnover of a model cytokine ARE-mRNA containing the GM-CSF ARE.

Nuclear import and export functions in the different isoforms of the AUF1/heterogeneous nuclear ribonucleoprotein protein family.

The heterogeneous nuclear ribonucleoprotein D family of proteins also known as AUF1 consists of four isoforms implicated in both nuclear and cytoplasmic functions. The AUF1 proteins are largely nuclear but also are found in the cytoplasm and are thought to undergo nucleocytoplasmic shuttling. The nucleocytoplasmic distribution and potential shuttling activity of the individual AUF1 isoforms have not been previously studied in detail. Therefore, we characterized the nucleocytoplasmic transport of each of the heterogeneous nuclear ribonucleoprotein D/AUF1 isoforms. All four AUF1 proteins were found to undergo rapid nucleocytoplasmic shuttling in a manner that is transcription-independent, carrier-mediated, and energy-requiring. Nucleocytoplasmic shuttling of the AUF1 proteins is shown to utilize a novel arrangement of nuclear import and export signals. Mutagenesis of the AUF1 proteins and fusion of polypeptides to a green fluorescent protein reporter demonstrated that a nuclear import signal is located in the C-terminal domain of the protein and is found only in the two smaller isoforms. Further mapping demonstrated that nuclear export is facilitated by sequences in AUF1 exon 7 found in the C-terminal domain of the two larger AUF1 isoforms. A subset of AUF1 proteins are shown to directly interact in vitro using purified recombinant proteins and in vivo in the absence of RNA. These results suggest that nuclear import of AUF1 is facilitated by sequences found only in the two smaller isoforms and that nuclear export is facilitated by sequences (exon 7 and the C-terminal domain) found only in the two larger isoforms. This novel arrangement of signals might represent a mechanism to assure co-shuttling of a subset of AUF1 proteins that interact in a heterocomplex.

Nutritional control of mRNA stability is mediated by a conserved AU-rich element that binds the cytoplasmic shuttling protein HuR.

The cationic amino acid transporter, Cat-1, is a high affinity transporter of the essential amino acids, arginine and lysine. Expression of the cat-1 gene increases during nutritional stress as part of the adaptive response to starvation. Amino acid limitation induces coordinate increases in stability and translation of the cat-1 mRNA, at a time when global protein synthesis decreases. It is shown here that increased cat-1 mRNA stability requires an 11 nucleotide AU-rich element within the distal 217 bases of the 3'-untranslated region. When this 217-nucleotide nutrient sensor AU-rich element (NS-ARE) is present in a chimeric mRNA it confers mRNA stabilization during amino acid starvation. HuR is a member of the ELAV family of RNA-binding proteins that has been implicated in regulating the stability of ARE-containing mRNAs. We show here that the cytoplasmic concentration of HuR increases during amino acid starvation, at a time when total cellular HuR levels decrease. In addition, RNA gel shift experiments in vitro demonstrated that HuR binds to the NS-ARE and binding was dependent on the 11 residue AU-rich element. Moreover, HuR binding to the NS-ARE in extracts from amino acid-starved cells increased in parallel with the accumulation of cytoplasmic HuR. It is proposed that an adaptive response of cells to nutritional stress results in increased mRNA stability mediated by HuR binding to the NS-ARE.