Single-shot ptychographic imaging of non-repetitive ultrafast events.

We demonstrate experimentally high-speed ptychographic imaging of non-repetitive complex-valued events. Three time-resolved complex-valued frames are reconstructed from data recorded in a single camera snapshot. The temporal resolution of the microscope is determined by delays between illuminating pulses. The ability to image amplitude and phase of nonrepetitive events with ultrafast temporal resolution will open new opportunities in science and technology.

Angiotensin II Induces Oxidative Stress and Endothelial Dysfunction in Mouse Ophthalmic Arteries via Involvement of AT1 Receptors and NOX2.

Angiotensin II (Ang II) has been implicated in the pathophysiology of various age-dependent ocular diseases. The purpose of this study was to test the hypothesis that Ang II induces endothelial dysfunction in mouse ophthalmic arteries and to identify the underlying mechanisms. Ophthalmic arteries were exposed to Ang II in vivo and in vitro to determine vascular function by video microscopy. Moreover, the formation of reactive oxygen species (ROS) was quantified and the expression of prooxidant redox genes and proteins was determined. The endothelium-dependent artery responses were blunted after both in vivo and in vitro exposure to Ang II. The Ang II type 1 receptor (AT1R) blocker, candesartan, and the ROS scavenger, Tiron, prevented Ang II-induced endothelial dysfunction. ROS levels and NOX2 expression were increased following Ang II incubation. Remarkably, Ang II failed to induce endothelial dysfunction in ophthalmic arteries from NOX2-deficient mice. Following Ang II incubation, endothelium-dependent vasodilation was mainly mediated by cytochrome P450 oxygenase (CYP450) metabolites, while the contribution of nitric oxide synthase (NOS) and 12/15-lipoxygenase (12/15-LOX) pathways became negligible. These findings provide evidence that Ang II induces endothelial dysfunction in mouse ophthalmic arteries via AT1R activation and NOX2-dependent ROS formation. From a clinical point of view, the blockade of AT1R signaling and/or NOX2 may be helpful to retain or restore endothelial function in ocular blood vessels in certain ocular diseases.

Endoscopic full-thickness resection and its treatment alternatives in difficult-to-treat lesions of the lower gastrointestinal tract: a cost-effectiveness analysis.

OBJECTIVE: Endoscopic full-thickness resection (EFTR) has shown efficacy and safety in the colorectum. The aim of this analysis was to investigate whether EFTR is cost-effective in comparison with surgical and endoscopic treatment alternatives. DESIGN: Real data from the study cohort of the prospective, single-arm WALL RESECT study were used. A simulated comparison arm was created based on a survey that included suggested treatment alternatives to EFTR of the respective lesions. Treatment costs and reimbursement were calculated in euro according to the coding rules of 2017 and 2019 (EFTR). R0 resection rate was used as a measure of effectiveness. To assess cost-effectiveness, the average cost-effectiveness ratio (ACER) and the incremental cost-effectiveness ratio (ICER) were determined. Calculations were made both from the perspective of the care provider as well as of the payer. RESULTS: The cost per case was €2852.20 for the EFTR group, €1712 for the standard endoscopic resection (SER) group, €8895 for the surgical resection group and €5828 for the pooled alternative treatment to EFTR. From the perspective of the care provider, the ACER (mean cost per R0 resection) was €3708.98 for EFTR, €3115.10 for SER, €8924.05 for surgical treatment and €7169.30 for all pooled and weighted alternatives to EFTR. The ICER (additional cost per R0 resection compared with EFTR) was €5196.47 for SER, €26 533.13 for surgical resection and €67 768.62 for the pooled rate of alternatives. Results from the perspective of the payer were similar. CONCLUSION: EFTR is cost-effective in comparison with surgical and endoscopic treatment alternatives in the colorectum.

Colonoscopic full-thickness resection using an over-the-scope device: a prospective multicentre study in various indications.

OBJECTIVE: Endoscopic full-thickness resection (EFTR) is a novel treatment of colorectal lesions not amenable to conventional endoscopic resection. The aim of this prospective multicentre study was to assess the efficacy and safety of the full-thickness resection device. DESIGN: 181 patients were recruited in 9 centres with the indication of difficult adenomas (non-lifting and/or at difficult locations), early cancers and subepithelial tumours (SET). Primary endpoint was complete en bloc and R0 resection. RESULTS: EFTR was technically successful in 89.5%, R0 resection rate was 76.9%. In 127 patients with difficult adenomas and benign histology, R0 resection rate was 77.7%. In 14 cases, lesions harboured unsuspected cancer, another 15 lesions were primarily known as cancers. Of these 29 cases, R0 resection was achieved in 72.4%; 8 further cases had deep submucosal infiltration >1000 µm. Therefore, curative resection could only be achieved in 13/29 (44.8%). In the subgroup with SET (n=23), R0 resection rate was 87.0%. In general, R0 resection rate was higher with lesions ≤2 cm vs >2 cm (81.2% vs 58.1%, p=0.0038). Adverse event rate was 9.9% with a 2.2% rate of emergency surgery. Three-month follow-up was available from 154 cases and recurrent/residual tumour was evident in 15.3%. CONCLUSION: EFTR has a reasonable technical efficacy especially in lesions ≤2 cm with acceptable complication rates. Curative resection rate for early cancers was too low to recommend its primary use in this indication. Further comparative studies have to show the clinical value and long-term outcome of EFTR in benign colorectal lesions. TRIAL REGISTRATION NUMBER: NCT02362126; Results.

Sub-Nyquist Sampling and Fourier Domain Beamforming in Volumetric Ultrasound Imaging.

A key step in ultrasound image formation is digital beamforming of signals sampled by several transducer elements placed upon an array. High-resolution digital beamforming introduces the demand for sampling rates significantly higher than the signals' Nyquist rate, which greatly increases the volume of data that must be transmitted from the system's front end. In 3-D ultrasound imaging, 2-D transducer arrays rather than 1-D arrays are used, and more scan lines are needed. This implies that the amount of sampled data is vastly increased with respect to 2-D imaging. In this work, we show that a considerable reduction in data rate can be achieved by applying the ideas of Xampling and frequency domain beamforming (FDBF), leading to a sub-Nyquist sampling rate, which uses only a portion of the bandwidth of the ultrasound signals to reconstruct the image. We extend previous work on FDBF for 2-D ultrasound imaging to accommodate the geometry imposed by volumetric scanning and a 2-D grid of transducer elements. High image quality from low-rate samples is demonstrated by simulation of a phantom image composed of several small reflectors. Our technique is then applied to raw data of a heart ventricle phantom obtained by a commercial 3-D ultrasound system. We show that by performing 3-D beamforming in the frequency domain, sub-Nyquist sampling and low processing rate are achievable, while maintaining adequate image quality.

Removal of foreign bodies in the upper gastrointestinal tract in adults: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the removal of foreign bodies in the upper gastrointestinal tract in adults. Recommendations Nonendoscopic measures 1 ESGE recommends diagnostic evaluation based on the patient's history and symptoms. ESGE recommends a physical examination focused on the patient's general condition and to assess signs of any complications (strong recommendation, low quality evidence). 2 ESGE does not recommend radiological evaluation for patients with nonbony food bolus impaction without complications. We recommend plain radiography to assess the presence, location, size, configuration, and number of ingested foreign bodies if ingestion of radiopaque objects is suspected or type of object is unknown (strong recommendation, low quality evidence). 3 ESGE recommends computed tomography (CT) scan in all patients with suspected perforation or other complication that may require surgery (strong recommendation, low quality evidence). 4 ESGE does not recommend barium swallow, because of the risk of aspiration and worsening of the endoscopic visualization (strong recommendation, low quality evidence). 5 ESGE recommends clinical observation without the need for endoscopic removal for management of asymptomatic patients with ingestion of blunt and small objects (except batteries and magnets). If feasible, outpatient management is appropriate (strong recommendation, low quality evidence). 6 ESGE recommends close observation in asymptomatic individuals who have concealed packets of drugs by swallowing ("body packing"). We recommend against endoscopic retrieval. We recommend surgical referral in cases of suspected packet rupture, failure of packets to progress, or intestinal obstruction (strong recommendation, low quality evidence). Endoscopic measures 7 ESGE recommends emergent (preferably within 2 hours, but at the latest within 6 hours) therapeutic esophagogastroduodenoscopy for foreign bodies inducing complete esophageal obstruction, and for sharp-pointed objects or batteries in the esophagus. We recommend urgent (within 24 hours) therapeutic esophagogastroduodenoscopy for other esophageal foreign bodies without complete obstruction (strong recommendation, low quality evidence). 8 ESGE suggests treatment of food bolus impaction in the esophagus by gently pushing the bolus into the stomach. If this procedure is not successful, retrieval should be considered (weak recommendation, low quality evidence). The effectiveness of medical treatment of esophageal food bolus impaction is debated. It is therefore recommended, that medical treatment should not delay endoscopy (strong recommendation, low quality evidence). 9 In cases of food bolus impaction, ESGE recommends a diagnostic work-up for potential underlying disease, including histological evaluation, in addition to therapeutic endoscopy (strong recommendation, low quality evidence). 10 ESGE recommends urgent (within 24 hours) therapeutic esophagogastroduodenoscopy for foreign bodies in the stomach such as sharp-pointed objects, magnets, batteries and large/long objects. We suggest nonurgent (within 72 hours) therapeutic esophagogastroduodenoscopy for medium-sized blunt foreign bodies in the stomach (strong recommendation, low quality evidence). 11 ESGE recommends the use of a protective device in order to avoid esophagogastric/pharyngeal damage and aspiration during endoscopic extraction of sharp-pointed foreign bodies. Endotracheal intubation should be considered in the case of high risk of aspiration (strong recommendation, low quality evidence). 12 ESGE suggests the use of suitable extraction devices according to the type and location of the ingested foreign body (weak recommendation, low quality evidence). 13 After successful and uncomplicated endoscopic removal of ingested foreign bodies, ESGE suggests that the patient may be discharged. If foreign bodies are not or cannot be removed, a case-by-case approach depending on the size and type of the foreign body is suggested (weak recommendation, low quality evidence).

Subjective distress after seclusion or mechanical restraint: one-year follow-up of a randomized controlled study.

OBJECTIVE: Patients who participated in a randomized controlled trial comparing subjective distress and traumatic impact after seclusion or mechanical restraint were interviewed about the coercive measure about one year later. METHODS: Between May and December 2006, patients were interviewed about one year after experiencing seclusion or mechanical restraint as an inpatient. Items from the Coercion Experience Scale (CES) were used in the original and the follow-up studies to assess distress on a 5-point scale, with higher scores indicating greater distress. Patients were also asked about subjective feelings about the coercive measure and completed the Impact of Event Scale-Revised (IES-R) to assess symptoms of posttraumatic stress disorder (PTSD). RESULTS: Sixty (59%) of the 102 patients in the original sample were included for follow-up. Although the original study found no differences between patients who experienced seclusion or mechanical restraint, the follow-up study found significantly higher mean scores for CES items among patients who had experienced mechanical restraint (2.5 and 3.7, respectively, p<.001). IES-R scores did not differ significantly. IES-R scores for two patients who experienced mechanical restraint and one who experienced seclusion indicated probable PTSD. Patients reported experiencing a wide range of negative feelings during the measure, most frequently helplessness, tension, fear, and rage. However, 58% reported some positive effects. Contact with staff was most helpful in alleviating distress during the coercive measure. CONCLUSIONS: Contrary to the original study, the follow-up study suggested that seclusion might be a less restrictive alternative for most patients. The incidence of PTSD seemed lower than expected.

Assessment of cardiac allograft vasculopathy late after heart transplantation: when is coronary angiography necessary?

BACKGROUND: Cardiac allograft vasculopathy (CAV) represents a major prognostic factor in long-term survivors of heart transplantation (HTx). Reliable diagnosis of CAV late after HTx is important but remains the domain of invasive techniques such as coronary angiography. METHODS: To test alternative approaches, 54 consecutive HTx recipients (mean time since HTx: 52 months) were studied with intravascular ultrasound (IVUS), angiography, dobutamine stress echocardiography and immunofluorescence staining against anti-thrombin III (AT-III) in endomyocardial biopsies. Univariate and multivariate predictors as well as receiver-operating-characteristic (ROC) curves of different sets of predictors were calculated. RESULTS: Using IVUS as reference standard, CAV was present in 80% of subjects. Coronary angiography identified CAV correctly in only 44% of cases. If AT-III staining alone was used as a diagnostic criterion, CAV was correctly identified in 77% of subjects. In a multivariate analysis, only AT-III, donor age and echocardiography at rest emerged as independent predictors of CAV (p < 0.05 for all), yielding an excellent discriminative power. CONCLUSIONS: With almost equal reliability when compared with IVUS, CAV can be identified using information on donor age, wall motion score at rest and AT-III staining late after HTx. Coronary angiography may be limited to patients with a high probability score and should not be used routinely for surveillance of CAV.