1,158 research outputs found

    Response and relapse rates after treatment with long-acting somatostatin analogs in multifocal or recurrent type-1 gastric carcinoids : a systematic review and meta-analysis

    Get PDF
    Background: Type-1 gastric neuroendocrine tumors represent a recurring disease and long-acting somatostatin analogs can inhibit both gastrin release and endocrine cell proliferation. The efficacy and timing of this treatment are still unclear. We performed a systematic review of the literature to clarify the role of somatostatin analog treatment in type-1 gastric neuroendocrine tumors. Methods: A computerized literature search was performed using relevant keywords to identify all the pertinent articles published in the last 15 years. Results: Eight studies were included in this systematic review on somatostatin analogs in type-1 gastric neuroendocrine tumors. A complete response rate ranged from 25\u2013100%. When only the six prospective studies were considered, no significant heterogeneity was observed, and the pooled cumulative complete response rate was 84.5% (confidence interval 73.8\u201392.8). Three studies evaluated the type-1 gastric neuroendocrine tumor recurrence, with a cumulative relapse rate of 30.2% (confidence interval 13.1\u201350.6) after 34 months. Conclusion: Somatostatin analogs, namely lanreotide and octreotide, have an excellent response rate, with a good safety profile in selected type-1 gastric neuroendocrine tumors, which cannot be safely managed by endoscopic follow-up or resection due to multiple or frequently recurring disease. After therapy discontinuation, the cumulative relapse rate observed after a median 34-month follow-up was relatively high (30.2%)

    Gauge equivalence in QCD: the Weyl and Coulomb gauges

    Full text link
    The Weyl-gauge (A0a=0)A_0^a=0) QCD Hamiltonian is unitarily transformed to a representation in which it is expressed entirely in terms of gauge-invariant quark and gluon fields. In a subspace of gauge-invariant states we have constructed that implement the non-Abelian Gauss's law, this unitarily transformed Weyl-gauge Hamiltonian can be further transformed and, under appropriate circumstances, can be identified with the QCD Hamiltonian in the Coulomb gauge. We demonstrate an isomorphism that materially facilitates the application of this Hamiltonian to a variety of physical processes, including the evaluation of SS-matrix elements. This isomorphism relates the gauge-invariant representation of the Hamiltonian and the required set of gauge-invariant states to a Hamiltonian of the same functional form but dependent on ordinary unconstrained Weyl-gauge fields operating within a space of ``standard'' perturbative states. The fact that the gauge-invariant chromoelectric field is not hermitian has important implications for the functional form of the Hamiltonian finally obtained. When this nonhermiticity is taken into account, the ``extra'' vertices in Christ and Lee's Coulomb-gauge Hamiltonian are natural outgrowths of the formalism. When this nonhermiticity is neglected, the Hamiltonian used in the earlier work of Gribov and others results.Comment: 25 page

    Putting theory oriented evaluation into practice

    Get PDF
    Evaluations of gaming simulations and business games as teaching devices are typically end-state driven. This emphasis fails to detect how the simulation being evaluated does or does not bring about its desired consequences. This paper advances the use of a logic model approach which possesses a holistic perspective that aims at including all elements associated with the situation created by a game. The use of the logic model approach is illustrated as applied to Simgame, a board game created for secondary school level business education in six European Union countries

    A wait-and-watch approach to small pancreatic neuroendocrine tumors : Prognosis and survival

    Get PDF
    Background: Whether all the small (\u3c6 6420mm) non-functional pancreatic neuroendocrine neoplasms (pNENs) should be routinely resected is unclear. Aim: To assess the overall survival (OS) and progression-free survival (PFS) of patients with small pNENs, followed-up with different management options. Material and methods: Between 2007-2014, 51 patients were newly diagnosed with pNEN. 15 patients with pNENs \u3c6 6420 mm underwent an intensive follow-up at 3-month intervals during the first year and then every 6 months (FU pNEN group). They were all at TNM stage I, except for one patient at stage IIA. 21 patients underwent surgical resection (SR pNEN group): 2 patients were at TNM stage I, 9 IIA, one IIIB, 9 IV. 15 patients received systemic therapy (ST pNEN group) due to advanced disease or contraindications to surgery: 5 were at stage IIA, 2 IIB, 8 IV. Results: The median follow-up for the entire cohort was 50 months. Survival was similar in the FU and SR pNEN groups, but significantly worst in the ST pNEN patients (log-rank test P < 0.05). The 4-year survival rate was 100% in the FU pNEN group, 90.5% among the SR pNEN patients, 61% for the ST pNEN ones (p < 0.0001). The disease remained stable in all but one patient in the FU pNEN group, whereas six patients in the SR group and five in the ST group showed disease progression. Conclusions: The "wait-and-watch" approach to early-stage small pNENs appears to be safe although further studies are needed to confirm these results in larger cohorts of patients

    Kosterlitz Thouless Universality in Dimer Models

    Full text link
    Using the monomer-dimer representation of strongly coupled U(N) lattice gauge theories with staggered fermions, we study finite temperature chiral phase transitions in (2+1) dimensions. A new cluster algorithm allows us to compute monomer-monomer and dimer-dimer correlations at zero monomer density (chiral limit) accurately on large lattices. This makes it possible to show convincingly, for the first time, that these models undergo a finite temperature phase transition which belongs to the Kosterlitz-Thouless universality class. We find that this universality class is unaffected even in the large N limit. This shows that the mean field analysis often used in this limit breaks down in the critical region.Comment: 4 pages, 4 figure

    Hepatic hemangioma in celiac patients : data from a large consecutive series

    Get PDF
    Background and Aims. Hepatic hemangioma (HH) has a widely ranging prevalence. The etiology is unclear; however, associations with autoimmune disorders have been described. We aimed at evaluating the prevalence of HH in celiac disease. Methods. Ninety-seven consecutive patients with celiac disease (18 M, 79 F, median age 41, and range 17-84 years) underwent liver ultrasound between January 2011 and 2012. The findings were compared with those of 1352 nonceliac patients (581 M, 771 F, median age 50, and range 16-94 years), without liver disease or previously detected HH, who underwent US in the same period. Results. Ultrasonographic findings consistent with HH were observed in 14 celiac patients (14.4%), a prevalence significantly higher than in controls (69 cases, 5.1%) (P=0.0006). Subgroup analysis showed that, among women, the prevalence of HH was 16.4% in the celiac disease group (13/79) compared with 5.9% in controls (46/771) (P=0.002). In celiac setting, HH had a median diameter of 1.3 cm and presented as a single lesion in 12 cases (86%). Conclusions. Our findings are consistent with a significantly higher prevalence of HH in celiac patients. Although mechanisms underlying this association remain unclear, autoimmune and metabolic processes, as well as alterations of gut-liver axis equilibrium, could play a role

    Anti-tumour necrosis factor agent and liver injury : literature review, recommendations for management

    Get PDF
    Abnormalities in liver function tests, including transient and self-limiting hypertransaminasemia, cholestatic disease and hepatitis, can develop during treatment with anti-tumour-necrosis-factor (TNF) therapy. The optimal management of liver injury related to anti-TNF therapy is still a matter of debate. Although some authors recommend discontinuing treatment in case of both a rise of alanine aminotransferase more than 5 times the upper limit of normal, or the occurrence of jaundice, there are no standard guidelines for the management of anti-TNF-related liver injury. Bibliographical searches were performed in PubMed, using the following key words: inflammatory bowel disease (IBD); TNF inhibitors; hypertransaminasemia; drug-related liver injury; infliximab. According to published data, elevation of transaminases in patients with IBD treated with anti-TNF is a common finding, but resolution appears to be the usual outcome. Anti-TNF agents seem to be safe with a low risk of causing severe drug-related liver injury. According to our centre experience, we found that hypertransaminasemia was a common, mainly self-limiting finding in our IBD cohort and was not correlated to infliximab treatment on both univariate and multivariate analyses. An algorithm for the management of liver impairment occurring during anti-TNF treatment is also proposed and this highlights the need of a multidisciplinary approach and suggests liver biopsy as a key-point in the management decision in case of severe rise of transaminases. However, hepatic injury is generally self-limiting and drug withdrawal seems to be an exception

    Zero-point vacancies in quantum solids

    Full text link
    A Jastrow wave function (JWF) and a shadow wave function (SWF) describe a quantum solid with Bose--Einstein condensate; i.e. a supersolid. It is known that both JWF and SWF describe a quantum solid with also a finite equilibrium concentration of vacancies x_v. We outline a route for estimating x_v by exploiting the existing formal equivalence between the absolute square of the ground state wave function and the Boltzmann weight of a classical solid. We compute x_v for the quantum solids described by JWF and SWF employing very accurate numerical techniques. For JWF we find a very small value for the zero point vacancy concentration, x_v=(1.4\pm0.1) x 10^-6. For SWF, which presently gives the best variational description of solid 4He, we find the significantly larger value x_v=(1.4\pm0.1) x 10^-3 at a density close to melting. We also study two and three vacancies. We find that there is a strong short range attraction but the vacancies do not form a bound state.Comment: 19 pages, submitted to J. Low Temp. Phy
    • 

    corecore