669 research outputs found

    Hybrid fiber grating cavity for multi-parametric sensing.

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    We propose an all-fiber hybrid cavity involving two unbalanced uniform fiber Bragg gratings (FBGs) written at both sides of a tilted FBG (TFBG) to form an all-fiber interferometer. This configuration provides a wavelength gated reflection signal with interference fringes depending on the cavity features modulated by spectral dips associated to the wavelength dependent optical losses due to cladding mode coupling occurring along the TFBG. Such a robust structure preserves the advantages of uniform FBGs in terms of interrogation methods and allows the possibility of simultaneous physical and chemical sensing

    Pancreaticoduodenectomy model demonstrates a fundamental role of dysfunctional β cells in predicting diabetes

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    BACKGROUND. The appearance of hyperglycemia is due to insulin resistance, functional deficits in the secretion of insulin, and a reduction of β cell mass. There is a long-standing debate as to the relative contribution of these factors to clinically manifesting β cell dysfunction. The aim of this study was to verify the acute effect of one of these factors, the reduction of β cell mass, on the subsequent development of hyperglycemia. METHODS. To pursue this aim, nondiabetic patients, scheduled for identical pancreaticoduodenectomy surgery, underwent oral glucose tolerance tests (OGTT) and hyperglycemic clamp (HC) procedures, followed by arginine stimulation before and after surgery. Based on postsurgery OGTT, subjects were divided into 3 groups depending on glucose tolerance: normal glucose tolerance (post-NGT), impaired glucose tolerance (post-IGT), or having diabetes mellitus (post-DM). RESULTS. At baseline, the 3 groups showed similar fasting glucose and insulin levels; however, examining the various parameters, we found that reduced first-phase insulin secretion, reduced glucose sensitivity, and rate sensitivity were predictors of eventual postsurgery development of IGT and diabetes. CONCLUSION. Despite comparable functional mass and fasting glucose and insulin levels at baseline and the very same 50% mass reduction, only reduced first-phase insulin secretion and glucose sensitivity predicted the appearance of hyperglycemia. These functional alterations could be pivotal to the pathogenesis of type 2 diabetes (T2DM)

    Unusual focal keratin expression in plexiform angiomyxoid myofibroblastic tumor: A case report and review of the literature

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    Background: Plexiform angiomyxoid myofibroblastic tumor (PAMT), also known as plexiform fibromyxoma, is a rare distinctive benign intramural tumor, typical of gastric antrum, commonly causing mucosal ulceration with upper gastrointestinal bleeding and anemia, effectively treated by complete surgical resection usually accomplished by distal gastrectomy. Methods and Results: We herein report a 47-year-old man presenting with a syncopal episode, regurgitation and epigastric discomfort, bearing a gastric antral myxoid plexiform tumor positive for \u3b1-smooth muscle actin, vimentin and, partially, for caldesmon, desmin, and CD10; CD117, DOG1, CD34, S100, CAM5.2, CK20, CK7, EMA, p53, CDX2, chromogranin A, synaptophysin, anaplastic lymphoma kinase, Melan-A, and HMB-45 were all negative. All these features are typical of PAMT. Of note, focal positivity for AE1/AE3 and pan-CK KL1 was also present. Conclusions: The finding of a focal keratin expression in PAMT contributes to enlarge the immunophenotypic spectrum of this tumor type and is relevant for avoiding presurgical misdiagnoses which could ultimately lead to inappropriate overtreatment of patients with PAMT

    Preserving privacy in surgical video analysis using a deep learning classifier to identify out-of-body scenes in endoscopic videos

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    Surgical video analysis facilitates education and research. However, video recordings of endoscopic surgeries can contain privacy-sensitive information, especially if the endoscopic camera is moved out of the body of patients and out-of-body scenes are recorded. Therefore, identification of out-of-body scenes in endoscopic videos is of major importance to preserve the privacy of patients and operating room staff. This study developed and validated a deep learning model for the identification of out-of-body images in endoscopic videos. The model was trained and evaluated on an internal dataset of 12 different types of laparoscopic and robotic surgeries and was externally validated on two independent multicentric test datasets of laparoscopic gastric bypass and cholecystectomy surgeries. Model performance was evaluated compared to human ground truth annotations measuring the receiver operating characteristic area under the curve (ROC AUC). The internal dataset consisting of 356,267 images from 48 videos and the two multicentric test datasets consisting of 54,385 and 58,349 images from 10 and 20 videos, respectively, were annotated. The model identified out-of-body images with 99.97% ROC AUC on the internal test dataset. Mean +/- standard deviation ROC AUC on the multicentric gastric bypass dataset was 99.94 +/- 0.07% and 99.71 +/- 0.40% on the multicentric cholecystectomy dataset, respectively. The model can reliably identify out-of-body images in endoscopic videos and is publicly shared. This facilitates privacy preservation in surgical video analysis

    Role of radiomics in predicting lymph node metastasis in gastric cancer: a systematic review

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    IntroductionGastric cancer (GC) is an aggressive and clinically heterogeneous tumor, and better risk stratification of lymph node metastasis (LNM) could lead to personalized treatments. The role of radiomics in the prediction of nodal involvement in GC has not yet been systematically assessed. This study aims to assess the role of radiomics in the prediction of LNM in GC.MethodsA PubMed/MEDLINE systematic review was conducted to assess the role of radiomics in LNM. The inclusion criteria were as follows: i. original articles, ii. articles on radiomics, and iii. articles on LNM prediction in GC. All articles were selected and analyzed by a multidisciplinary board of two radiation oncologists and one surgeon, under the supervision of one radiation oncologist, one surgeon, and one medical oncologist.ResultsA total of 171 studies were obtained using the search strategy mentioned on PubMed. After the complete selection process, a total of 20 papers were considered eligible for the analysis of the results. Radiomics methods were applied in GC to assess the LNM risk. The number of patients, imaging modalities, type of predictive models, number of radiomics features, TRIPOD classification, and performances of the models were reported.ConclusionsRadiomics seems to be a promising approach for evaluating the risk of LNM in GC. Further and larger studies are required to evaluate the clinical impact of the inclusion of radiomics in a comprehensive decision support system (DSS) for GC

    The Role of Staging Laparoscopy for Gastric Cancer Patients: Current Evidence and Future Perspectives

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    A significant proportion of patients diagnosed with gastric cancer is discovered with peritoneal metastases at laparotomy. Despite the continuous improvement in the performance of radiological imaging, the preoperative recognition of such an advanced disease is still challenging during the diagnostic work-up, since the sensitivity of CT scans to peritoneal carcinomatosis is not always adequate. Staging laparoscopy offers the chance to significantly increase the rate of promptly diagnosed peritoneal metastases, thus reducing the number of unnecessary laparotomies and modifying the initial treatment strategy of gastric cancer. The aim of this review was to provide a comprehensive summary of the current literature regarding the role of staging laparoscopy in the management of gastric cancer. Indications, techniques, accuracy, advantages, and limitations of staging laparoscopy and peritoneal cytology were discussed. Furthermore, a focus on current evidence regarding the application of artificial intelligence and image-guided surgery in staging laparoscopy was included in order to provide a picture of the future perspectives of this technique and its integration with modern tools in the preoperative management of gastric cancer

    The Clinical Frailty Scale (CFS) as an Independent Prognostic Factor for Patients ≥80 Years with Small Bowel Obstruction (SBO)

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    Background: SBO is a potentially life-threatening condition that often affects older patients. Frailty, more than age, is expected to play a crucial role in predicting SBO prognosis in this population. This study aims to define the influence of Clinical Frailty Scale (CFS) on mortality and major complications in patients ≥80 years with diagnosis of SBO at the emergency department (ED). Methods: All patients aged ≥80 years admitted to our ED for SBO from January 2015 to September 2020 were enrolled. Frailty was assessed through the CFS, and then analyzed both as a continuous and a dichotomous variable. The endpoints were in-hospital mortality and major complications. Results: A total of 424 patients were enrolled. Higher mortality (20.8% vs 8.6%, p<0.001), longer hospital stay (9 [range 5-14] days vs 7 [range 4-12] days, p=0.014), and higher rate of major complications (29.9% vs 17.9%, p=0.004) were associated with CFS ≥7. CFS score and bloodstream infection were the only independent prognostic factors for mortality (OR 1.72 [CI: 1.29-2.29], p<0.001; OR 4.69 [CI: 1.74-12.6], p=0.002, respectively). Furthermore, CFS score, male sex and surgery were predictive factors for major complications (OR 1.41 [CI: 1.13-1.75], p=0.002; OR 1.67 [CI: 1.03-2.71], p=0.038); OR 1.91 [CI: 1.17-3.12], p=0.01; respectively). At multivariate analysis, for every 1-point increase in CFS score, the odds of mortality and the odds of major complications increased 1.72-fold and 1.41-fold, respectively. Conclusion: The increase in CFS is directly associated with an increased risk of mortality and major complications. The presence of severe frailty could effectively predict an increased risk of in-hospital death regardless of the treatment administered. The employment of CFS in elderly patients could help the identification of the need for closer monitoring and proper goals of care

    Intra-islet insulin synthesis defects are associated with endoplasmic reticulum stress and loss of beta cell identity in human diabetes

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    Aims/hypothesis: Endoplasmic reticulum (ER) stress and beta cell dedifferentiation both play leading roles in impaired insulin secretion in overt type 2 diabetes. Whether and how these factors are related in the natural history of the disease remains, however, unclear. Methods: In this study, we analysed pancreas biopsies from a cohort of metabolically characterised living donors to identify defects in in situ insulin synthesis and intra-islet expression of ER stress and beta cell phenotype markers. Results: We provide evidence that in situ altered insulin processing is closely connected to in vivo worsening of beta cell function. Further, activation of ER stress genes reflects the alteration of insulin processing in situ. Using a combination of 17 different markers, we characterised individual pancreatic islets from normal glucose tolerant, impaired glucose tolerant and type 2 diabetic participants and reconstructed disease progression. Conclusions/interpretation: Our study suggests that increased beta cell workload is accompanied by a progressive increase in ER stress with defects in insulin synthesis and loss of beta cell identity. Graphical abstract: [Figure not available: see fulltext.

    Status of faecal pollution in ports: A basin-wide investigation in the Adriatic Sea

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    Ports are subject to a variety of anthropogenic impacts, and there is mounting evidence of faecal contamination through several routes. Yet, little is known about pollution in ports by faecal indicator bacteria (FIB). FIB spatio-temporal dynamics were assessed in 12 ports of the Adriatic Sea, a semi-enclosed basin under strong anthropogenic pressure, and their relationships with environmental variables were explored to gain insight into pollution sources. FIB were abundant in ports, often more so than in adjacent areas ; their abundance patterns were related to salinity, oxygen, and nutrient levels. In addition, a molecular method, quantitative (q)PCR, was used to quantify FIB. qPCR enabled faster FIB determination and water quality monitoring that culture-based methods. These data provide robust baseline evidence of faecal contamination in ports and can be used to improve the management of routine port activities (dredging and ballast water exchange), having potential to spread pathogens in the sea

    Adhesive small bowel obstruction in octogenarians: A 6-year retrospective single-center analysis of clinical management and outcomes

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    Background: Few evidences are available on adhesive bowel obstruction (ASBO)management and outcomes in geriatric patients. Methods: One-hundred-twenty-eight patients aged 65–79 years were retrospectively compared to 77 patients aged ≥80 years. Aim of this study was to compare ASBO management and in-hospital course between patients aged 65–79 years and those over 80 years. Results: Upfront surgery in octogenarians related with a higher rate of major complications (23.7%vs4.9%; p = 0.009) and longer hospitalization (8.8vs7.3 days; p = 0.01). No difference according to age was noted in terms of clinical outcomes when the non-operative management (NOM) was employed. Patients aged ≥80 years managed conservatively presented shorter hospitalization (7.3vs8.8 days; p = 0.04), lower rate of intensive care unit (ICU) admission (0vs18.4%; p = 0.005) and cumulative major complications (2.6%vs23.7%; p = 0.007) as compared to ≥80 years old patients treated with upfront surgery. In this same group, NOM failure did not lead to worse outcomes in comparison to upfront surgery. Conclusions: NOM in≥80 years patients is associated with better in-hospital course. The acceptable clinical outcomes in case of NOM failure further support NOM as first treatment strategy to employ in this same subset of patients
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