226 research outputs found

    Breaking the Conformal Gauge by Fixing Time Protocols

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    We review the definition by Perlick of standard clocks in a Weyl geometry and show how a congruence of clocks can be used to fix the conformal gauge in the EPS framework. Examples are discussed in details.Comment: 14 pages, 4 figur

    Unusual Development of Iatrogenic Complex, Mixed Biliary and Duodenal Fistulas Complicating Roux-en-Y Antrectomy for Stenotic Peptic Disease of the Supraampullary Duodenum Requiring Whipple Procedure: An Uncommon Clinical Dilemma

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    Complex fistulas of the duodenum and biliary tree are severe complications of gastric surgery. The association of duodenal and major biliary fistulas occurs rarely and is a major challenge for treatment. They may occur during virtually any kind of operation, but they are more frequent in cases complicated by the presence of difficult duodenal ulcers or cancer, with a mortality rate of up to 35%. Options for treatment are many and range from simple drainage to extended resections and difficult reconstructions. Conservative treatment is the choice for well-drained fistulas, but some cases require reoperation. Very little is known about reoperation techniques and technical selection of the right patients. We present the case of a complex iatrogenic duodenal and biliary fistula. A 42-year-old Caucasian man with a diagnosis of postoperative peritonitis had been operated on 3 days earlier; an antrectomy with a Roux-en-Y reconstruction for stenotic peptic disease was performed. Conservative treatment was attempted with mixed results. Two more operations were required to achieve a definitive resolution of the fistula and related local complications. The decision was made to perform a pancreatoduodenectomy with subsequent reconstruction on a double jejunal loop. The patient did well and was discharged on postoperative day 17. In our experience pancreaticoduodenectomy may be an effective treatment of refractory and complex iatrogenic fistulas involving both the duodenum and the biliary tree

    Circulating dendritic cells are severely decreased in idiopathic pulmonary fibrosis with a potential value for prognosis prediction

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    Dendritic cells (DCs) accumulate in the lung of patients affected by idiopathic pulmonary fibrosis (IPF). We measured the frequencies of circulating conventional CD1c + and CD141+ cells (namely, cDC2 and cDC1) and of plasmacytoid CD303+ DCs in a cohort of 60 therapy naive IPF patients by flow cytometry. Peripheral levels of reactive oxygen species (ROS) and of pro-inflammatory and Th1/Th2 polarizing cytokines were also analyzed. All blood DC subtypes were significantly reduced in IPF patients in comparison to age- and sex-matched controls, while ROS and interleukin (IL-6) levels were augmented. IL-6 expression increased along with disease severity, according to the gender-age-physiology index, and correlated with the frequency of cDC2. IL-6 and cDC2 were not influenced by anti-fibrotic therapies but were associated with a reduced survival, the latter being an independent predictive biomarker of worse prognosis. Deciphering the role of DCs in IPF might provide information on disease pathogenesis and clinical behavior

    Sporadic, Nontrauma-Related, Desmoid Tumor of the Pancreas: A Rare Disease—Case Report and Literature Review

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    Desmoid tumors (DTs) are neoplasms of fibroblastic origin characterized by lack of a capsule. They are nonmetastatic and locally aggressive. Intraabdominal DTs are often observed in familial adenomatous polyposis and Gardner syndrome or subsequent to localized traumatic injury. Sporadic forms are defined as nontrauma- or nongenetic-related DTs. Isolated, sporadic pancreatic DTs have been considered anecdotal, with only 9 cases described in the literature. We report the case of a 68-year-old man with a case of sporadic cystic DT localized to the pancreatic tail. The tumor was discovered incidentally during computerized tomography performed for an unrelated condition. The patient was asymptomatic; however, biopsy was performed on the clinical suspicion of cystic cancer of the pancreas. Pathology analysis showed fibroblastic proliferation, and the diagnosis of DT was confirmed by immunohistochemical staining for beta-catenin. The patient underwent resection with no further treatment and remain disease-free 60 months after surgery

    Late gastrointestinal tissue effects after hypofractionated radiation therapy of the pancreas

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    Background To consolidate literature reports of serious late gastrointestinal toxicities after hypofractionated radiation treatment of pancreatic cancer and attempt to derive normal tissue complication probability (NTCP) parameters using the Lyman-Kutcher-Burman model. Methods Published reports of late grade 3 or greater gastrointestinal toxicity after hypofractionated treatment of pancreatic cancer were reviewed. The biologically equivalent dose in 1.8 Gy fractions was calculated using the EQD model. NTCP parameters were calculated using the LKB model assuming 1–5 % of the normal tissue volume was exposed to the prescription dose with α/β ratios of 3 or 4. Results A total of 16 human studies were examined encompassing a total of 1160 patients. Toxicities consisted of ulcers, hemorrhages, obstructions, strictures, and perforations. Non-hemorrhagic and non-perforated ulcers occurred at a rate of 9.1 % and were the most commonly reported toxicity. Derived NTCP parameter ranges were as follows: n = 0.38–0.63, m = 0.48–0.49, and TD50 = 35–95 Gy. Regression analysis showed that among various study characteristics, dose was the only significant predictor of toxicity. Conclusions Published gastrointestinal toxicity reports after hypofractionated radiotherapy for pancreatic cancer were compiled. Median dose was predictive of late grade ≥ 3 gastrointestinal toxicity. Preliminary NTCP parameters were derived for multiple volume constraints

    A phase-I trial of pre-operative, margin intensive, stereotactic body radiation therapy for pancreatic cancer: the 'SPARC' trial protocol.

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    BACKGROUND: Standard therapy for borderline-resectable pancreatic cancer in the UK is surgery with adjuvant chemotherapy, but rates of resection with clear margins are unsatisfactory and overall survival remains poor. Meta-analysis of single-arm studies shows the potential of neo-adjuvant chemo-radiotherapy but the relative radio-resistance of pancreatic cancer means the efficacy of conventional dose schedules is limited. Stereotactic radiotherapy achieves sufficient accuracy and precision to enable pre-operative margin-intensive dose escalation with the goal of increasing rates of clear resection margins and local disease control. METHODS/DESIGN: SPARC is a "rolling-six" design single-arm study to establish the maximum tolerated dose for margin-intensive stereotactic radiotherapy before resection of pancreatic cancer at high risk of positive resection margins. Eligible patients will have histologically or cytologically proven pancreatic cancer defined as borderline-resectable per National Comprehensive Cancer Network criteria or operable tumour in contact with vessels increasing the risk of positive margin. Up to 24 patients will be recruited from up to 5 treating centres and a 'rolling-six' design is utilised to minimise delays and facilitate ongoing recruitment during dose-escalation. Radiotherapy will be delivered in 5 daily fractions and surgery, if appropriate, will take place 5-6 weeks after radiotherapy. The margin-intense radiotherapy concept includes a systematic method to define the target volume for a simultaneous integrated boost in the region of tumour-vessel infiltration, and up to 4 radiotherapy dose levels will be investigated. Maximum tolerated dose is defined as the highest dose at which no more than 1 of 6 patients or 0 of 3 patients experience a dose limiting toxicity. Secondary endpoints include resection rate, resection margin status, response rate, overall survival and progression free survival at 12 and 24 months. Translational work will involve exploratory analyses of the cytological and humoral immunological responses to stereotactic radiotherapy in pancreatic cancer. Radiotherapy quality assurance of target definition and radiotherapy planning is enforced with pre-trial test cases and on-trial review. Recruitment began in April 2015. DISCUSSION: This prospective multi-centre study aims to establish the maximum tolerated dose of pre-operative margin-intensified stereotactic radiotherapy in pancreatic cancer at high risk of positive resection margins with a view to subsequent definitive comparison with other neoadjuvant treatment options

    Neoadjuvant treatment of pancreatic adenocarcinoma: a systematic review and meta-analysis of 5520 patients

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