Comparison of highly pure rAAV9 vector stocks produced in suspension by PEI transfection or HSV infection reveals striking quantitative and qualitative differences.

Recent clinical successes have propelled recombinant adeno-associated virus vectors (rAAV) to the center stage for human gene therapy applications. However, the exploding demand for high titers of highly pure rAAV vectors for clinical applications and market needs remains hindered by challenges met at the manufacturing stage. The production of rAAV by transfection in suspension cells remains one of the most commonly used production platforms. In this study, we describe our optimized protocol to produce rAAV by polyethyleneimine (PEI)-mediated transfection in suspension HEK293 cells, along with a side-by-side comparison to our high-performing system using the herpes simplex virus (HSV). Further, we detail a new, robust, and highly efficient downstream purification protocol compatible with both transfection and infection-based harvests that generated rAAV9 stocks of high purity. Our in-depth comparison revealed quantitative, qualitative, and biological differences between PEI-mediated transfection and HSV infection. The HSV production system yielded to higher rAAV vector titers, higher specific yields, and a higher percentage of full capsids than transfection. Furthermore, HSV-produced stocks had a significantly lower concentration of residual host cell proteins and helper DNA impurities, but contained detectable levels of HSV DNA. Importantly, the potency of PEI-produced and HSV-produced rAAV stocks were identical. Analyses of AAV Rep and Cap expression levels and replication showed that HSV-mediated production led to a lower expression of Rep and Cap, but increased levels of AAV genome replication. Our methodology enables high-yield, high purity rAAV production and a biological framework to improve transfection quality and yields by mimicking HSV-induced biological outcomes.

NaCl and KCl mediate log increase in AAV vector particles and infectious titers in a specific/timely manner with the HSV platform.

The increasing demand for adeno-associated virus (AAV) vectors, a result from the surging interest for their potential to cure human genetic diseases by gene transfer, tumbled on low-performing production systems. Innovative improvements to increase both yield and quality of the vector produced have become a priority undertaking in the field. In a previous study, we showed that adding a specific concentration of sodium chloride (NaCl) to the production medium resulted in a dramatic increase of AAV vector particle and infectious titers when using the herpes simplex virus (HSV) production system, both in adherent or suspension platforms. In this work, we studied additional salts and their impact on AAV vector production. We found that potassium chloride (KCl), or a combination of KCl and NaCl, resulted in the highest increase in AAV vector production. We determined that the salt-mediated effect was the most impactful when the salt was present between 8 and approximately 16 h post-infection, with the highest rate increase occurring within the first 24 h of the production cycle. We showed that the AAV vector yield increase did not result from an increase in cell growth, size, or viability. Furthermore, we demonstrated that the impact on AAV vector production was specifically mediated by NaCl and KCl independently of their impact on the osmolality of the production media. Our findings convincingly showed that NaCl and KCl were uniquely efficacious to promote up to a 10-fold increase in the production of highly infectious AAV vectors when produced in the presence of HSV. We think that this study will provide unique and important new insights in AAV biology toward the establishment of more successful production protocols.

Billing, Coding, and Credentialing for Interventional Radiology-Operated Endoscopy.

A sound understanding of billing and coding is essential to start a successful interventional radiology endoscopy practice. While the codes utilized are similar to gastrointestinal and genitourinary endoscopy codes, physicians and institutional coders need to be familiar with the codes used for these types of procedures in the interventional radiology setting. The following manuscript gives a brief overview of aspects relating to credentialing, billing, and coding in interventional radiology endoscopy.

Transnasal stent-assisted targeting technique for percutaneous jejunostomy placement in patients with hiatal hernias.

PURPOSE: To report the transnasal stent-assisted targeting technique for percutaneous jejunostomy placement in patients with hiatal hernias. MATERIALS AND METHODS: Four patients, including three (75%) females and one (25%) male, with mean age of 77.5 years (range 73-78 years), and with a hiatal hernia and intrathoracic stomach precluding gastrostomy placement and loop snare placement into the mid-jejunum underwent the transnasal stent-assisted targeting technique for percutaneous jejunostomy placement. In all patients, a duodenal stent was inserted into the jejunum in a transnasal fashion. The stent was partially unsheathed in an anterior loop of jejunum and percutaneously targeted using an 18-gauge needle through which a guidewire was advanced, trapped within the stent, and removed through the nose. The tract was serially dilated and a jejunostomy was placed. Technical success, procedure time, fluoroscopy time, radiation exposure, complications, time to enteral feeding, and follow-up were recorded. RESULTS: Technical success was 100% (4/4) with all four patients requiring only one needle pass before successful jejunal cannulation. Mean procedure time was 108 min. Mean fluoroscopy time was 44 min. Mean dose area product was 3969.3 µGym2. No minor or major complications occurred. All four patients received enteral feeding one day after the procedure. Mean follow-up was 366 days. CONCLUSION: The transnasal stent-assisted targeting technique is a novel method for primary jejunostomy placement in patients with hiatal hernias.

#VascularSurgery.

BACKGROUND: To characterize the vascular surgery Twitter network. METHODS: A total of 20,841 consecutive tweets by 8,282 unique Twitter accounts regarding vascular surgery from October 23, 2014 to January 15, 2018 were analyzed. Twitter analytics, including activity metrics, content analysis, user characteristics, engagement, and network analysis were performed using Symplur Signals, a health care social media analytics platform. RESULTS: Vascular surgery tweets, the number of users tweeting about vascular surgery, and vascular surgery tweet impressions have increased by an annual average of 77.8%, 55.3%, and 209.1% from 2015 to 2017, respectively. Twitter activity trend analysis showed consistent growth over the study period with an average of 25.7 ± 2.6 additional tweets per month (P < 0.001). As for tweet content, 2,220 tweets (10.7%) were pertaining to patients, and 2,198 tweets (10.5%) were regarding new or innovative topics. 15,422 tweets (74.0%) included links to journals or websites and 6,826 tweets (32.8%) contained at least 1 image. Deep venous thrombosis, pulmonary embolism, diabetes, endovascular interventions, trauma, and practice guidelines were among the most commonly discussed health topics. Physicians composed 5,618 tweets (27%), while patients submitted 2,447 tweets (11.7%). As for engagement, 8,886 tweets (42.6%) were retweets, 11,816 tweets (56.7%) mentioned at least 1 other user, and 786 tweets (3.8%) were replies. Network analysis revealed central hubs to be vascular surgery societies, academic institutions, academic journals, and physicians. CONCLUSIONS: The use of Twitter to discuss vascular surgery is growing rapidly with increasing use by vascular surgeons and vascular medicine physicians. An effort to involve more patients in the vascular surgery Twitter social network may allow for more opportunities to educate, and garner interest and support for vascular surgery.

Contemporary Interventional Radiology Dosimetry: Analysis of 4,784 Discrete Procedures at a Single Institution.

PURPOSE: To report dosimetry of commonly performed interventional radiology procedures and compare dose analogues to known reference levels. MATERIALS AND METHODS: Demographic and dosimetry data were collected for gastrostomy, nephrostomy, peripherally inserted central catheter placement, visceral arteriography, hepatic chemoembolization, tunneled catheter placement, inferior vena cava filter placement, vascular embolization, transjugular liver biopsy, adrenal vein sampling, transjugular intrahepatic portosystemic shunt (TIPS) creation, and biliary drainage between June 12, 2014, and April 26, 2018, using integrated dosimetry software. In all, 4,784 procedures were analyzed. The study included 2,691 (56.2%) male subjects and 2,093 (43.8%) female subjects with mean age 55 ± 21 years (range: 0-104 years) and with mean weight of 76.9 ± 29.4 kg (range: 0.9-268.1 kg). Fluoroscopy time, dose area product (DAP), and reference dose were evaluated. RESULTS: TIPS had the highest mean fluoroscopy time (49.1 ± 16.0 min) followed by vascular embolization (25.2 ± 11.4 min), hepatic chemoembolization (18.8 ± 12.5 min), and visceral arteriography (17.7 ± 3.2 min). TIPS had the highest mean DAP (429.2 ± 244.8 grays per square centimeter [Gy·· cm2]) followed by hepatic chemoembolization (354.6 ± 78.6 Gy·· cm2), visceral arteriography (309.5 ± 39.0 Gy·· cm2), and vascular embolization (298.5 ± 29 Gy·· cm2). TIPS was associated with the highest mean reference dose (2.002 ± 1.420 Gy) followed by hepatic chemoembolization (1.746 ± 0.435 Gy), vascular embolization (1.615 ± 0.381 Gy), and visceral arteriography (1.558 ± 1.720 Gy). Of the six procedures available for comparison with the reference levels, the mean fluoroscopy time, DAP, and reference dose for each procedure were below the proposed reference levels. CONCLUSION: Advances in image acquisition technology and radiation safety protocols have significantly reduced the radiation exposure for a variety of interventional radiology procedures.

Diffusion Quantification in Body Imaging.

Diffusion-weighted imaging (DWI) is increasingly incorporated into routine body magnetic resonance imaging protocols. DWI can assist with lesion detection and even in characterization. Quantitative DWI has exhibited promise in the discrimination between benign and malignant pathology, in the evaluation of the biologic aggressiveness, and in the assessment of the response to treatment. Unfortunately, inconsistencies in DWI acquisition parameters and analysis have hampered widespread clinical utilization. Focusing primarily on liver applications, this article will review the basic principles of quantitative DWI. In addition to standard mono-exponential fitting, the authors will discuss intravoxel incoherent motion and diffusion kurtosis imaging that involve more sophisticated approaches to diffusion quantification.

Policy-Relevant Context of Waterpipe Tobacco Smoking among University Students in Six Countries Across the Eastern Mediterranean Region: A Qualitative Study

Background: Waterpipe tobacco smoking rates in the Eastern Mediterranean region are some of the highest worldwide, especially among young people. This study aimed to improve our knowledge of the policy-relevant context of waterpipe smoking among six countries in the Eastern Mediterranean region. Methods: In-depth interviews were conducted in Bahrain, Egypt, Jordan, Lebanon, Palestine, and the United Arab Emirates. Participants were young adult university students (18-29 years) from both genders who had ever smoked the waterpipe, recruited from universities participating in this study. Directed content analysis was used to analyze the transcripts. Results: A total of 53 in-depth interviews were conducted in Arabic in 2016. Findings were organized around 5 themes: waterpipe product characteristics; patterns of waterpipe smoking; the waterpipe café setting; perceived health consequences; and health warning labels. Waterpipe smoking was commonly perceived as a safe alternative to cigarettes. Waterpipe tobacco was reported to be widely accessible and affordable to young participants. There is a lack of knowledge among waterpipe smokers about the associated health effects. Warning labels are effective at communicating health risks associated with waterpipe smoking. Conclusions: Regulatory frameworks for waterpipe tobacco smoking should be developed and enforced, including waterpipe-specific health warning labels that elucidate the harmful effects of waterpipe smoking.

Strengths and Deficiencies in the Content of US Radiology Private Practices' Websites.

PURPOSE: The Internet provides a potentially valuable mechanism for radiology practices to communicate with patients and enhance the patient experience. The aim of this study was to assess the websites of US radiology private practices, with attention to the frequency of content of potential patient interest. METHODS: The 50 largest private practice radiology facilities in the United States were identified from RadiologyBusiness.com. Websites were reviewed for information content and functionality. RESULTS: Content regarding radiologists' names, medical schools, residencies, fellowships, photographs, and board certification status; contact for billing questions; and ability to make online payments was present on 80% to 98% of sites. Content regarding examination preparation, contrast use, examination duration, description of examination experience, scheduling information, directions, privacy policy, radiologists' role in interpretation, and ACR accreditation was present on 60% to 78%. Content regarding accepted insurers, delivery of results to referrers, report turnaround times, radiologists' years of experience, radiation safety, and facility hours was present on 40% to 58%. Content regarding technologist certification, registration forms, instructions for requesting a study on disc, educational videos, and patient testimonials was present on 20% to 38%. Content regarding examination prices, patient satisfaction scores, peer review, online scheduling, online report and image access, and parking was present on <20%. CONCLUSIONS: Radiology practices' websites most frequently provided information regarding their radiologists' credentials, as well as billing and payment options. Information regarding quality, safety, and the examination experience, as well as non-payment-related online functionality, was less common. These findings regarding the most common deficiencies may be useful for radiology practices in expanding their websites' content, thereby improving communication and potentially the patient experience.