87 research outputs found

    MACHINE LEARNING FOR CLASSIFICATION OF AN ERODING SCARP SURFACE USING TERRESTRIAL PHOTOGRAMMETRY WITH NIR AND RGB IMAGERY

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    Abstract. Increasingly advanced and affordable close-range sensing techniques are employed by an ever-broadening range of users, with varying competence and experience. In this context a method was tested that uses photogrammetry and classification by machine learning to divide a point cloud into different surface type classes. The study site is a peat scarp 20 metres long in the actively eroding river bank of the Rotmoos valley near Obergurgl, Austria. Imagery from near-infra red (NIR) and conventional (RGB) sensors, georeferenced with coordinates of targets surveyed with a total station, was used to create a point cloud using structure from motion and dense image matching. NIR and RGB information were merged into a single point cloud and 18 geometric features were extracted using three different radii (0.02 m, 0.05 m and 0.1 m) totalling 58 variables on which to apply the machine learning classification. Segments representing six classes, dry grass, green grass, peat, rock, snow and target, were extracted from the point cloud and split into a training set and a testing set. A Random Forest machine learning model was trained using machine learning packages in the R-CRAN environment. The overall classification accuracy and Kappa Index were 98% and 97% respectively. Rock, snow and target classes had the highest producer and user accuracies. Dry and green grass had the highest omission (1.9% and 5.6% respectively) and commission errors (3.3% and 3.4% respectively). Analysis of feature importance revealed that the spectral descriptors (NIR, R, G, B) were by far the most important determinants followed by verticality at 0.1 m radius

    Serum proteomics in giant cell arteritis in response to a three-day pulse of glucocorticoid followed by tocilizumab monotherapy (the GUSTO trial).

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    OBJECTIVE Proteome analyses in patients with newly diagnosed, untreated giant cell arteritis (GCA) have not been reported previously, nor are changes of protein expression upon treatment with glucocorticoids (GC) and/or tocilizumab (TCZ) known. The GUSTO trial allows to address these questions, provides the opportunity to learn about the differential effects of GC and TCZ on proteomics and may help to identify serum proteins to monitor disease activity. METHODS Serum samples obtained from 16 patients with new-onset GCA at different time points (day 0, 3, 10, and week 4, 24, 52) during the GUSTO trial (NCT03745586) were examined for 1436 differentially expressed proteins (DEPs) based on proximity extension assay technology. The patients received 500 mg methylprednisolone intravenously for 3 consecutive days followed by TCZ monotherapy. RESULTS When comparing day 0 (before the first GC infusion) with week 52 (lasting remission), 434 DEPs (213↑, 221↓) were identified. In response to treatment, the majority of changes occurred within 10 days. GC inversely regulated 25 proteins compared to remission. No difference was observed between weeks 24 and 52 during established remission and ongoing TCZ treatment. Expression of CCL7, MMP12, and CXCL9 was not regulated by IL6. CONCLUSION Disease-regulated serum proteins improved within 10 days and were normalized within 24 weeks, showing a kinetic corresponding to the gradual achievement of clinical remission. The proteins inversely regulated by GC and TCZ shed light on the differential effects of the two drugs. CCL7, CXCL9, and MMP12 are biomarkers that reflect disease activity despite normalized C-reactive protein levels

    Quantitative ultrasound to monitor the vascular response to tocilizumab in giant cell arteritis.

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    OBJECTIVES To characterize the effect of ultra-short glucocorticoids followed by Tocilizumab monotherapy on the intima-media thickness (IMT) in GCA. METHODS 18 GCA patients received 500mg methylprednisolone intravenously on days 0-2, followed by Tocilizumab (8mg/kg) intravenously on day 3 and thereafter weekly subcutaneous Tocilizumab injections (162 mg) over 52 weeks. Ultrasound of temporal (TA), axillary (AA) and subclavian (SA) arteries was performed at baseline, on days 2-3, at week 4, 8, 12, 24 and 52. The largest IMT of all segments and IMT at landmarks of AA/SA were recorded. IMT was scaled by mean normal values and averaged. Each segment was classified according to diagnostic cut-offs. RESULTS 16 patients had TA and 6 had extracranial large artery involvement. The IMT showed a sharp decline on day 2/3 in the TA and AA/SA. In TA, this was followed by an increase to baseline levels at week 4 and a subsequent slow decrease, which was paralleled by decreasing symptoms and achievement of clinical remission. The AA/SA showed a new signal of vasculitis at week 4 in three patients with an IMT increase up to week 8. CONCLUSIONS Glucocorticoid pulse therapy induced a transient decrease of the IMT in TA and AA/SA. Tocilizumab monotherapy resulted in a slow and steady decrease in IMT of the TA and a smaller and delayed effect on the AA/SA. The data strongly support a remission-inducing effect of Tocilizumab and argue for an important role of ultrasound in monitoring disease activity in GCA

    Predictors of Successful Decannulation Using a Tracheostomy Retainer in Patients with Prolonged Weaning and Persisting Respiratory Failure

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    Background: For percutaneously tracheostomized patients with prolonged weaning and persisting respiratory failure, the adequate time point for safe decannulation and switch to noninvasive ventilation is an important clinical issue. Objectives: We aimed to evaluate the usefulness of a tracheostomy retainer (TR) and the predictors of successful decannulation. Methods: We studied 166 of 384 patients with prolonged weaning in whom a TR was inserted into a tracheostoma. Patients were analyzed with regard to successful decannulation and characterized by blood gas values, the duration of previous spontaneous breathing, Simplified Acute Physiology Score (SAPS) and laboratory parameters. Results: In 47 patients (28.3%) recannulation was necessary, mostly due to respiratory decompensation and aspiration. Overall, 80.6% of the patients could be liberated from a tracheostomy with the help of a TR. The need for recannulation was associated with a shorter duration of spontaneous breathing within the last 24/48 h (p < 0.01 each), lower arterial oxygen tension (p = 0.025), greater age (p = 0.025), and a higher creatinine level (p = 0.003) and SAPS (p < 0.001). The risk for recannulation was 9.5% when patients breathed spontaneously for 19-24 h within the 24 h prior to decannulation, but 75.0% when patients breathed for only 0-6 h without ventilatory support (p < 0.001). According to ROC analysis, the SAPS best predicted successful decannulation {[}AUC 0.725 (95% CI: 0.634-0.815), p < 0.001]. Recannulated patients had longer durations of intubation (p = 0.046), tracheostomy (p = 0.003) and hospital stay (p < 0.001). Conclusion: In percutaneously tracheostomized patients with prolonged weaning, the use of a TR seems to facilitate and improve the weaning process considerably. The duration of spontaneous breathing prior to decannulation, age and oxygenation describe the risk for recannulation in these patients. Copyright (c) 2012 S. Karger AG, Base

    Clear cell chondrosarcoma of the head and neck

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    Clear cell chondrosarcoma is a rare variant of chondrosarcoma that mostly involves the end of long bones. However, nine cases have been reported in the head and neck: four in larynx, two in nasal septum, two in maxilla and one in the skull. These cases form the basis of this review. Head and neck cases accounts for less than 5% of Clear cell chondrosarcomas in the whole body and the larynx is the most common place. The histological findings of head and neck cases are consistent with general features of this entity in the whole body and nearly all tumors in this case series had a component of conventional chondrosarcoma. Clear cell chondrosarcoma is an intracompartmental tumor and retains "Grenz zone" just beneath the epithelium. Therefore, the overlying mucosa remained intact in all laryngeal cases. Nasal tumor caused ballooning of the septum and the maxillary lesion did not involve the oral mucosa. This tumor presents various radiographic features in the head and neck area. Chondroblastoma, chondroma, osteoblastoma, osteosarcoma and metastatic renal cell carcinoma are included in the histologic differential diagnoses. Differentiation from chondroblastic osteosarcoma is important in the maxilla. A wide resection is adequate in most cases. However, some laryngeal cases show tendency to recur. Clear cell chondrosarcoma is a slow growing tumor and this necessitates a long time follow-up of patients. Due to the extreme rarity in the head and neck, diagnosis of Clear cell chondrosarcoma in this area, must be confirmed by histochemical and immunohistochemical studies

    Smoking status and anti-inflammatory macrophages in bronchoalveolar lavage and induced sputum in COPD

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    <p>Abstract</p> <p>Background</p> <p>Macrophages have been implicated in the pathogenesis of COPD. M1 and M2 macrophages constitute subpopulations displaying pro- and anti-inflammatory properties. We hypothesized that smoking cessation affects macrophage heterogeneity in the lung of patients with COPD. Our aim was to study macrophage heterogeneity using the M2-marker CD163 and selected pro- and anti-inflammatory mediators in bronchoalveolar lavage (BAL) fluid and induced sputum from current smokers and ex-smokers with COPD.</p> <p>Methods</p> <p>114 COPD patients (72 current smokers; 42 ex-smokers, median smoking cessation 3.5 years) were studied cross-sectionally and underwent sputum induction (M/F 99/15, age 62 ± 8 [mean ± SD] years, 42 (31-55) [median (range)] packyears, post-bronchodilator FEV<sub>1 </sub>63 ± 9% predicted, no steroids past 6 months). BAL was collected from 71 patients. CD163<sup>+ </sup>macrophages were quantified in BAL and sputum cytospins. Pro- and anti-inflammatory mediators were measured in BAL and sputum supernatants.</p> <p>Results</p> <p>Ex-smokers with COPD had a higher percentage, but lower number of CD163<sup>+ </sup>macrophages in BAL than current smokers (83.5% and 68.0%, p = 0.04; 5.6 and 20.1 ×10<sup>4</sup>/ml, p = 0.001 respectively). The percentage CD163<sup>+ </sup>M2 macrophages was higher in BAL compared to sputum (74.0% and 30.3%, p < 0.001). BAL M-CSF levels were higher in smokers than ex-smokers (571 pg/ml and 150 pg/ml, p = 0.001) and correlated with the number of CD163<sup>+ </sup>BAL macrophages (Rs = 0.38, p = 0.003). No significant differences were found between smokers and ex-smokers in the levels of pro-inflammatory (IL-6 and IL-8), and anti-inflammatory (elafin, and Secretory Leukocyte Protease Inhibitor [SLPI]) mediators in BAL and sputum.</p> <p>Conclusions</p> <p>Our data suggest that smoking cessation partially changes the macrophage polarization <it>in vivo </it>in the periphery of the lung towards an anti-inflammatory phenotype, which is not accompanied by a decrease in inflammatory parameters.</p

    Cell Recovery in Bronchoalveolar Lavage Fluid in Smokers Is Dependent on Cumulative Smoking History

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    Background: Smoking is a risk factor for various lung diseases in which BAL may be used as a part of a clinical investigation. Interpretation of BAL fluid cellularity is however difficult due to high variability, in particular among smokers. In this study we aimed to evaluate the effect of smoking on BAL cellular components in asymptomatic smokers. The effects of smoking cessation, age and gender were also investigated in groups of smokers and exsmokers. Methods: We performed a retrospective review of BAL findings, to our knowledge the largest single center investigation, in our department from 1999 to 2009. One hundred thirty two current smokers (48 males and 84 females) and 44 ex-smokers (16 males and 28 females) were included. A group of 295 (132 males and 163 females) never-smokers served as reference. Result: The median [5–95 pctl] total number of cells and cell concentration in current smokers were 63.4 [28.6–132.1]610 6 and 382.1 [189.7–864.3]610 6 /L respectively and correlated positively to the cumulative smoking history. Macrophages were the predominant cell type (96.7 % [90.4–99.0]) followed by lymphocytes (2 % [0.8–7.7]) and neutrophils (0.6 % [0–2.9]). The concentration of all inflammatory cells was increased in smokers compared to never smokers and ex-smokers. BAL fluid recovery was negatively correlated with age (p,0.001). Smoking men had a lower BAL fluid recovery than smoking women. Conclusion: Smoking has a profound effect on BAL fluid cellularity, which is dependent on smoking history. Our results performed on a large group of current smokers and ex-smokers in a well standardized way, can contribute to bette

    Infectious Triggers in Periodontitis and the Gut in Rheumatoid Arthritis (RA): A Complex Story About Association and Causality.

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    Rheumatoid arthritis (RA) is a systemic immune mediated inflammatory disease of unknown origin, which is predominantly affecting the joints. Antibodies against citrullinated peptides are a rather specific immunological hallmark of this heterogeneous entity. Furthermore, certain sequences of the third hypervariable region of human leukocyte antigen (HLA)-DR class II major histocompatibility (MHC) molecules, the so called "shared epitope" sequences, appear to promote autoantibody positive types of RA. However, MHC-II molecule and other genetic associations with RA could not be linked to immune responses against specific citrullinated peptides, nor do genetic factors fully explain the origin of RA. Consequently, non-genetic factors must play an important role in the complex interaction of endogenous and exogenous disease factors. Tobacco smoking was the first environmental factor that was associated with onset and severity of RA. Notably, smoking is also an established risk factor for oral diseases. Furthermore, smoking is associated with extra-articular RA manifestations such as interstitial lung disease in anatomical proximity to the airway mucosa, but also with subcutaneous rheumatoid nodules. In the mouth, Porphyromonas gingivalis is a periodontal pathogen with unique citrullinating capacity of foreign microbial antigens as well as candidate RA autoantigens. Although the original hypothesis that this single pathogen is causative for RA remained unproven, epidemiological as well as experimental evidence linking periodontitis (PD) with RA is rapidly accumulating. Other periopathogens such as Aggregatibacter actinomycetemcomitans and Prevotella intermedia were also proposed to play a specific immunodominant role in context of RA. However, demonstration of T cell reactivity against citrullinated, MHC-II presented autoantigens from RA synovium coinciding with immunity against Prevotella copri (Pc.), a gut microbe attracted attention to another mucosal site, the intestine. Pc. was accumulated in the feces of clinically healthy subjects with citrulline directed immune responses and was correlated with RA onset. In conclusion, we retrieved more than one line of evidence for mucosal sites and different microbial taxa to be potentially involved in the development of RA. This review gives an overview of infectious agents and mucosal pathologies, and discusses the current evidence for causality between different exogenous or mucosal factors and systemic inflammation in RA
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