1,309 research outputs found
Cost-effectiveness of diagnostic laparoscopy for assessing resectability in pancreatic and periampullary cancer.
Surgical resection is the only curative treatment for pancreatic and periampullary cancer, but many patients undergo unnecessary laparotomy because tumours can be understaged by computerised tomography (CT). A recent Cochrane review found diagnostic laparoscopy can decrease unnecessary laparotomy. We compared the cost-effectiveness of diagnostic laparoscopy prior to laparotomy versus direct laparotomy in patients with pancreatic and periampullary cancer with resectable disease based on CT scanning
Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones.
Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs
Genomic homogeneity in fibrolamellar carcinomas
Background-Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma (HCC) with distinctive clinical and histological features. To date there have been few studies on the genotypic aspects of FLC and no previous attempts have been made to use the arbitrarily primed-polymerase chain reaction (AF-FCR) technique to detect genetic alterations in this disease.Aim-The aim of this study was to assess the degree of genomic heterogeneity of FEC using the AP-PCR technique. Methods-A fetal of 50 tissue samples of primary and metastatic FLCs from seven patients were microdissected. AP-PCR amplification of each genomic DNA sample was carried out using two arbitrary primers.Results-DNA fingerprints of the primary FLCs and all their metastatic lesions (both synchronous and metachronous disease) were identical in an individual patient. The fingerprints were different between tumours of different patients. No evidence of intratumour heterogeneity was observed.Conclusions-Such genomic homogeneity in FLCs may explain their indolent growth. The absence of clonal evolution, which is present in other tumours (particularly HCCs), may explain the distinct behaviour in this tumour. The tumorigenic pathway and degree of somatic genomic changes in this disease may be less complex than in HCC
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On the helicity characteristics and induced emf of magnetic-Coriolis wave packets
In a rapidly rotating Boussinesq fluid, buoyant anomalies radiate low-frequency inertial wave packets which disperse along the rotation axis. The wave packets lead to axially elongated vortices, which propagate negative (positive) kinetic helicity upwards (downwards) with respect to the rotation vector. The kinetic helicity carried by the inertial wave packets is near-maximal, relative to the velocity and vorticity fields. In classical mean-field theory, kinetic helicity is often associated with the Ī±-effect, which is thought to be an important ingredient for planetary dynamos. The modification of inertial wave packets in the presence of a transverse uniform magnetic field is investigated here, motivated by small-scale dynamics in planetary cores, where a large-scale magnetic field affects fluid motions. We study numerically the dispersion of wave packets from an isolated buoyant source and from a random layer of buoyant anomalies, while varying the Lehnert number Le ā the ratio of the frequencies of AlfvĆ©n and inertial waves. We find that for Le < 0.1, the vortices are columnar and continue to segregate kinetic helicity so that it is negative (positive) above (below) the buoyant source. Importantly, the wave packets induce an Ī±-effect, which remains strong and coherent for Earth-like values of the Lehnert number (Le < 0.1). The interaction of wave packets emitted by multiple neighbouring buoyant sources results in an Ī±-effect that is stronger than the Ī±-effect induced by wave packets launched from an isolated buoyant source, and we provide an analytical explanation for this. The coherence of the Ī±-effect induced by the wave packets, for Earth-like values of the Lehnert number, lends support to the Ī±2 dynamo model driven by helical waves
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A physical conjecture for the dipolar-multipolar dynamo transition
In numerical simulations of planetary dynamos there is an abrupt transition in the dynamics of both the velocity and magnetic fields at a ālocalā Rossby number of 0.1. For smaller Rossby numbers there are helical columnar structures aligned with the rotation axis, which efficiently maintain a dipolar field. However, when the thermal forcing is increased, these columns break down and the field becomes multi-polar. Similarly, in rotating turbulence experiments and simulations there is a sharp transition at a Rossby number of . Again, helical axial columnar structures are found for lower Rossby numbers, and there is strong evidence that these columns are created by inertial waves, at least on short time scales. We perform direct numerical simulations of the flow induced by a layer of buoyant anomalies subject to strong rotation, inspired by the equatorially biased heat flux in convective planetary dynamos. We assess the role of inertial waves in generating columnar structures. At high rotation rates (or weak forcing) we find columnar flow structures that segregate helicity either side of the buoyant layer, whose axial length scale increases linearly, as predicted by the theory of low-frequency inertial waves. As the rotation rate is weakened and the magnitude of the buoyant perturbations is increased, we identify a portion of the flow which is more strongly three-dimensional. We show that the flow in this region is turbulent, and has a Rossby number above a critical value , consistent with previous findings in rotating turbulence. We suggest that the discrepancy between the transition value found here (and in rotating turbulence experiments), and that seen in the numerical dynamos (), is a result of a different choice of the length scale used to define the local . We show that when a proxy for the flow length scale perpendicular to the rotation axis is used in this definition, the numerical dynamo transition lies at . Based on this we hypothesise that inertial waves, continually launched by buoyant anomalies, sustain the columnar structures in dynamo simulations, and that the transition documented in these simulations is due to the inability of inertial waves to propagate for Ro>Ro^{crit}.The Leverhulme Trust U
An Evaluation of Ischaemic Preconditioning as a Method of Reducing Ischaemia Reperfusion Injury in Liver Surgery and Transplantation
Liver Ischaemia Reperfusion (IR) injury is a major cause of post-operative liver dysfunction, morbidity and mortality following liver resection surgery and transplantation. There are no proven therapies for IR injury in clinical practice and new approaches are required. Ischaemic Preconditioning (IPC) can be applied in both a direct and remote fashion and has been shown to ameliorate IR injury in small animal models. Its translation into clinical practice has been difficult, primarily by a lack of knowledge regarding the dominant protective mechanisms that it employs. A review of all current studies would suggest that IPC/RIPC relies on creating a small tissue injury resulting in the release of adenosine and l-arginine which act through the Adenosine receptors and the haem-oxygenase and endothelial nitric oxide synthase systems to reduce hepatocyte necrosis and improve the hepatic microcirculation post reperfusion. The next key step is to determine how long the stimulus requires to precondition humans to allow sufficient injury to occur to release the potential mediators. This would open the door to a new therapeutic chapter in this field
Early acute kidney injury after liver transplantation: Predisposing factors and clinical implications
AIM: To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation. METHODS: This was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 Ć baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor ( 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome. RESULTS: Out of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049). CONCLUSION: HIRI has an important role in the development of AKI post-OLT and has a negative impact on patient outcomes, especially when occurring alongside AKI
Pregabalin for decreasing pancreatic pain in chronic pancreatitis
BACKGROUND: Chronic abdominal pain is one of the major symptoms in people with chronic pancreatitis. The role of pregabalin in people with chronic pancreatic pain due to chronic pancreatitis is uncertain. OBJECTIVES: To assess the benefits and harms of pregabalin in people with chronic abdominal pain due to chronic pancreatitis. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2015, issue 6, and MEDLINE, EMBASE, Science Citation Index Expanded, trials registers until June 2015. We also searched the references of included trials to identify further trials. SELECTION CRITERIA: We considered only randomised controlled trials (RCT) performed in people with chronic pancreatic pain due to chronic pancreatitis, irrespective of language, blinding, or publication status for inclusion in the review. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials and independently extracted data. We calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI) with RevMan 5, based on intention-to-treat analysis. MAIN RESULTS: Only one study, funded by Pfizer, met the inclusion criteria for the review. A total of 64 participants (with chronic pain due to chronic pancreatitis) were randomly assigned to receive escalating doses of pregabalin (150 mg per day to 600 mg per day; 34 participants) or matching placebo (30 participants). Participants received pregabalin or placebo for three weeks on an outpatient basis; the outcomes were measured at the end of the treatment (i.e. three weeks from commencement of treatment). Potential participants taking concomitant analgesic medication and expected to stay on a stable regime during the trial were allowed to enter the study. This trial was at low risk of bias. The overall quality of evidence was low or moderate.Only the short-term outcomes were available in this trial. The medium and long-term outcomes, number of work days lost, and length of hospital stay due to admissions for pain control were not available. This trial found that the changes in opiate use (MD -26.00 mg; 95% CI -47.36 to -4.64; participants = 64; moderate-quality evidence), and pain score percentage changes from baseline (MD -12.00; 95% CI -21.82 to -2.18; participants = 64; moderate-quality evidence) were better in participants taking pregabalin compared to those taking placebo. This trial also found that there were more adverse events in participants taking pregabalin compared to those taking placebo (RR 1.71; 95% CI 1.20 to 2.43; participants = 64). The differences between pregabalin and placebo were imprecise for short-term health-related quality of life measured with the EORTC CLQ-30 questionnaire (MD 11.40; 95% CI -3.28 to 26.08; participants = 64; moderate-quality evidence), proportion of people with serious adverse events (RR 1.76; 95% CI 0.35 to 8.96; participants = 64; low-quality evidence), and proportion of people requiring hospital admissions (RR 0.44; 95% CI 0.04 to 4.62; participants = 64; low quality evidence). AUTHORS' CONCLUSIONS: Based on low- to moderate-quality evidence, short-term use of pregabalin decreases short-term opiate use, and short-term pain scores, but increases the adverse events compared to placebo, in people with chronic pain due to chronic pancreatitis. The clinical implication of the decreases in short-term opiate use and short-term pain scores is not known.Future trials assessing the role of pregabalin in decreasing chronic pain in chronic pancreatitis should assess the medium- or long-term effects of pregabalin and should include outcomes such as, quality of life, treatment-related adverse events, number of work days lost, number of hospital admissions, and the length of hospital stay, in addition to pain scores, to assess the clinical and socioeconomic impact
Duodenum-preserving pancreatic resection versus pancreaticoduodenectomy for chronic pancreatitis
BACKGROUND: Surgical excision by removal of the head of the pancreas to decompress the obstructed ducts is one of the treatment options for people with symptomatic chronic pancreatitis. Surgical excision of the head of the pancreas can be performed by excision of the duodenum along with the head of the pancreas (pancreaticoduodenectomy (PD)) or without excision of the duodenum (duodenum-preserving pancreatic head resection (DPPHR)). There is currently no consensus on the method of pancreatic head resection in people with chronic pancreatitis. OBJECTIVES: To assess the benefits and harms of duodenum-preserving pancreatic head resection versus pancreaticoduodenectomy in people with chronic pancreatitis for whom pancreatic resection is considered the main treatment option. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, and trials registers to June 2015 to identify randomised trials. We also searched the references of included trials to identify further trials. SELECTION CRITERIA: We considered only randomised controlled trials (RCT) performed in people with chronic pancreatitis undergoing pancreatic head resection, irrespective of language, blinding, or publication status, for inclusion in the review. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials and extracted data. We calculated the risk ratio (RR), mean difference (MD), rate ratio (RaR), or hazard ratio (HR) with 95% confidence intervals (CI) based on an available-case analysis. MAIN RESULTS: Five trials including 292 participants met the inclusion criteria for the review. After exclusion of 23 participants mainly due to pancreatic cancer or because participants did not receive the planned treatment, a total of 269 participants (with symptomatic chronic pancreatitis involving the head of pancreas and requiring surgery) were randomly assigned to receive DPPHR (135 participants) or PD (134 participants). The trials did not report the American Society of Anesthesiologists (ASA) status of the participants. All the trials were single-centre trials and included people with and without obstructive jaundice and people with and without duodenal stenosis but did not report data separately for those with and without jaundice or those with and without duodenal stenosis. The surgical procedures compared in the five trials included DPPHR (Beger or Frey procedures, or wide local excision of the head of the pancreas) and PD (pylorus-preserving pancreaticoduodenectomy or Whipple procedure). The participants were followed up for various periods of time ranging from one to 15 years. The trials were at unclear or high risk of bias. The overall quality of evidence was low or very low.The differences in short-term mortality (up to 90 days after surgery) (RR 2.89, 95% CI 0.31 to 26.87; 369 participants; 5 studies; DPPHR: 2/135 (1.5%) versus PD: 0/134 (0%); very low quality evidence) or long-term mortality (maximal follow-up) (HR 0.65, 95% CI 0.31 to 1.34; 229 participants; 4 studies; very low quality evidence), medium-term (three months to five years) (only a narrative summary was possible; 229 participants; 4 studies; very low quality evidence), or long-term quality of life (more than five years) (MD 8.45, 95% CI -0.27 to 17.18; 101 participants; 2 studies; low quality evidence), proportion of people with adverse events (RR 0.55, 95% CI 0.22 to 1.35; 226 participants; 4 studies; DPPHR: 23/113 (adjusted proportion 20%) versus PD: 41/113 (36.3%); very low quality evidence), number of people with adverse events (RaR 0.95, 95% CI 0.43 to 2.12; 43 participants; 1 study; DPPHR: 12/22 (54.3 events per 100 participants) versus PD: 12/21 (57.1 events per 100 participants); very low quality evidence), proportion of people employed (maximal follow-up) (RR 1.54, 95% CI 1.00 to 2.37; 189 participants; 4 studies; DPPHR: 65/98 (adjusted proportion 69.4%) versus PD: 41/91 (45.1%); low quality evidence), incidence proportion of diabetes mellitus (maximum follow-up) (RR 0.78, 95% CI 0.50 to 1.22; 269 participants; 5 studies; DPPHR: 25/135 (adjusted proportion 18.6%) versus PD: 32/134 (23.9%); very low quality evidence), and prevalence proportion of pancreatic exocrine insufficiency (maximum follow-up) (RR 0.83, 95% CI 0.68 to 1.02; 189 participants; 4 studies; DPPHR: 62/98 (adjusted proportion 62.0%) versus PD: 68/91 (74.7%); very low quality evidence) were imprecise. The length of hospital stay appeared to be lower with DPPHR compared to PD and ranged between a reduction of one day and five days in the trials (208 participants; 4 studies; low quality evidence). None of the trials reported short-term quality of life (four weeks to three months), clinically significant pancreatic fistulas, serious adverse events, time to return to normal activity, time to return to work, and pain scores using a visual analogue scale. AUTHORS' CONCLUSIONS: Low quality evidence suggested that DPPHR may result in shorter hospital stay than PD. Based on low or very low quality evidence, there is currently no evidence of any difference in the mortality, adverse events, or quality of life between DPPHR and PD. However, the results were imprecise and further RCTs are required on this topic. Future RCTs comparing DPPHR with PD should report the severity as well as the incidence of postoperative complications and their impact on patient recovery. In such trials, participant and observer blinding should be performed and the analysis should be performed on an intention-to-treat basis to decrease the bias. In addition to the short-term benefits and harms such as mortality, surgery-related complications, quality of life, length of hospital stay, return to normal activity, and return to work, future trials should consider linkage of trial participants to health databases, social databases, and mortality registers to obtain the long-term benefits and harms of the different treatments
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