Complementary roles of interventional radiology and therapeutic endoscopy in gastroenterology

Acute upper and lower gastrointestinal bleeding, enteral feeding, cecostomy tubes and luminal strictures are some of the common reasons for gastroenterology service. While surgery was initially considered the main treatment modality, the advent of both therapeutic endoscopy and interventional radiology have resulted in the paradigm shift in the management of these conditions. In this paper, we discuss the patient’s work up, indications, and complementary roles of endoscopic and angiographic management in the settings of gastrointestinal bleeding, enteral feeding, cecostomy tube placement and luminal strictures. These conditions often require multidisciplinary approaches involving a team of interventional radiologists, gastroenterologists and surgeons. Further, the authors also aim to describe how the fields of interventional radiology and gastrointestinal endoscopy are overlapping and complementary in the management of these complex conditions

Between-strand disulfides: Forbidden disulfides linking adjacent ß-Strands

Between-strand disulfides (BSDs) connect cysteine (Cys) residues across adjacent strands of β-sheets. There are four BSD types which can be found in regular β-structure: CSDs, which link residues immediately opposite each other in the β-structure (residues i and j); ETDs, which connect Cys out of register by one residue (i and j ± 1); BDDs, which join Cys at positions i and j ± 2; and BFDs, which link residues i and j ± 3. Formation of these disulfides was initially predicted to be forbidden, producing too much local strain in the protein fold. However, BSDs do exist in nature. Significantly, their high levels of strain allow them to be involved in redox processes under physiological conditions. Here we characterise BSD motifs found in the Protein Data Bank (PDB), discussing important intrinsic factors, such as the disulfide conformation and torsional strain, and extrinsic factors, such as the influence of the β-sheet environment on the disulfide and vice versa. We also discuss the biological importance of BSDs, including the prevalence of non-homologous examples in the PDB, the conservation of BSD motifs amongst related proteins (BSD clusters) and experimental evidence for BSD redox activity. For clusters of homologous BSDs we present detailed data of the disulfide properties and the variations of these properties amongst the “redundant” structures. Identification of disulfides with the potential to be involved in biological redox processes via the analysis of these data will provide important insights into the function and mechanism of BSD-containing proteins. Characterisation of thiol-based redox signalling pathways will lead to significant breakthroughs in understanding the molecular basis of oxidative stress and associated pathways, such as ageing and neurodegenerative diseases

The persistent shadow of the supermassive black hole of M 87

In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3−3.1+1.5 μas. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30° relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ∼6.5 × 109 M⊙. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet

Acute Pancreatitis Due to Clipping of the Ampulla With Over-The-Scope Clip as a Complication of Bleeding Duodenal Ulcer Treatment

Over-the-scope clips (OTSC) (Ovesco, Tubingen, Germany) are commonly used for closure of bowel perforations, fistulas and to achieve hemostasis. This device is attached to the endoscope and delivers a variety of clips, based on diameter and depth, that works through tissue approximation. Complications including local inflammation, ulcers, or obstruction can occur. When the clip is misplaced or OTSC-associated complications occur, OTSC removal may be indicated. We present a case of a patient who presented to our hospital with upper gastrointestinal (GI) bleeding. OTSC was used to achieve hemostasis, however, the clip was misplaced over the ampulla of Vater. remOVE system (Ovesco, Tubingen, Germany) was used to remove the misplaced clip.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Hepatic applications of endoscopic ultrasound:Current status and future directions

The diagnosis and staging of various gastrointestinal malignancies have been made possible with the use of endoscopic ultrasound, which is a relatively safe procedure. The field of endoscopic ultrasound is fast expanding due to advancements in therapeutic endoscopic ultrasound. Though various studies have established its role in gastrointestinal malignancies and pancreatic conditions, its potential in the field of hepatic lesions still remains vastly untapped. In this paper the authors attempt to review important and landmark trials, case series and case studies involving hepatic applications of endoscopic ultrasound, thus not only providing an overview of utilization of endoscopic ultrasound in various liver conditions but also speculating its future role

Endosonography guided management of pancreatic fluid collections

The revised Atlanta classification of acute pancreatitis was adopted by international consensus, and is based on actual local and systemic determinants of disease severity. The local determinant is pancreatic necrosis (sterile or infected), and the systemic determinant is organ failure. Local complications of pancreatitis can include acute peri-pancreatic fluid collection, acute necrotic collection, pseudocyst formation, and walled-off necrosis. Interventional endoscopic ultrasound (EUS) has been increasing utilized in managing these local complications. After performing a PubMed search, the authors manually applied pre-defined inclusion criteria or a filter to identify publications relevant to EUS and pancreatic collections (PFCs). The authors then reviewed the utility, efficacy, and risks associated with using therapeutic EUS and involved EUS devices in treating PFCs. Due to the development and regulatory approval of improved and novel endoscopic devices specifically designed for transmural drainage of fluid and necrotic debris (access and patency devices), the authors predict continuing evolution in the management of PFCs. We believe that EUS will become an indispensable part of procedures used to diagnose PFCs and perform image-guided interventions. After draining a PFC, the amount of tissue necrosis is the most important predictor of a successful outcome. Hence, it seems logical to classify these collections based on their percentage of necrotic component or debris present when viewed by imaging methods or EUS. Finally, the authors propose an algorithm for managing fluid collections based on their size, location, associated symptoms, internal echogenic patterns, and content

Effect of Comorbidities on Inflammatory Bowel Disease-Related Colorectal Cancer: A Nationwide Inpatient Review

International audienceIntroduction: The risk of inflammatory bowel disease-associated colorectal cancer (IBD-CRC) is known to increase with primary sclerosing cholangitis (PSC) and a family history of CRC. However, the impact of comorbidities such as liver disease, obesity, diabetes, chronic lung, heart, and renal disease, and psychiatric illness on the risk of IBD-CRC remains unclear. We evaluated the effect of these comorbidities on the risk of IBD-CRC.Methods: A retrospective review from 2009 to 2014 was conducted using the National Inpatient Sample data for adults 18 years and older. Patients with IBD (360,892), of whom 2,831 had CRC were identified using the International Classification of Diseases, Ninth Revision codes (ICD-9). Data on comorbidities were also obtained. Adjusted odds ratios (aOR) and confidence intervals (CI) were computed via logistic regression to evaluate the effect of comorbidities on the risk of IBD-CRC; the p-value was set at <0.05.Results: The mean age of IBD patients in this study was 52.36±0.03. A majority of the patients with IBD-CRC were white and were significantly older compared to those without cancer (60 vs 52 years, p<0.05). The risk of colon cancer in IBD was increased by having a non-cholestatic liver disease (aOR 1.51, CI 1.23-1.86, p<0.01). Also, patients younger than 50 years with liver disease were at an increased risk of IBD-associated colon cancer in comparison to older patients (aOR 1.83 vs 1.34, p<0.05). Notably, diabetes, chronic pulmonary disease, renal failure, psychiatric illnesses, and rheumatoid diseases, were inversely associated with the risk of IBD-CRC (p<0.05). After stratifying by IBD subtypes, non-cholestatic liver disease was still independently associated with a higher risk for colon cancer in patients with ulcerative colitis or Crohn's disease (ulcerative colitis: aOR 1.43, CI 1.08-1.89; Crohn's disease: aOR 1.46, CI 1.10-2.00).Conclusions: Patients with IBD who have non-cholestatic liver disease might have a higher risk for colon cancer, even at a younger age. These patients may require close colon cancer surveillance