Suspension Culture Production and Purification of Adeno-Associated Virus by Iodixanol Density Gradient Centrifugation for In Vivo Applications.

This protocol describes recombinant adeno-associated virus (rAAV) production and purification by iodixanol density gradient centrifugation, a serotype-agnostic method of purifying AAV first described in 1999. rAAV vectors are widely used in gene therapy applications to deliver transgenes to various human cell types. In this work, the recombinant virus is produced by transfection of Expi293 cells in suspension culture with plasmids encoding the transgene, vector capsid, and adenoviral helper genes. Iodixanol density gradient centrifugation purifies full AAV particles based on particle density. Additionally, three steps are included in this now-ubiquitous methodology in order to increase total virus yield, decrease the risk of precipitation due to contaminating proteins, and further concentrate the final virus product, respectively: precipitation of viral particles from cell media using a solution of polyethylene glycol (PEG) and sodium chloride, the introduction of a second round of iodixanol density gradient centrifugation, and buffer exchange via a centrifugal filter. Using this method, it is possible to consistently achieve titers in the range of 1012 viral particles/mL of exceptional purity for in vivo use.

VA-ECMO-Facilitated Clot Debulking and PFO Closure in a Patient With Recurrent Pulmonary Thromboses.

A 27-year-old female with stage IIIc cervical cancer presented with dyspnea and stroke symptoms. Work-up revealed bilateral pulmonary embolisms, acute/subacute strokes, and a patent foramen ovale. After multidisciplinary team discussion, the patient underwent patent foramen ovale closure, complicated by cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation. She successfully underwent pulmonary thromboendarterectomy, extracorporeal membrane oxygenation decannulation, and hospital discharge.

Rational Design of AAV-rh74, AAV3B, and AAV8 with Limited Liver Targeting.

Recombinant adeno-associated viruses (rAAVs) have become one of the leading gene therapies for treating a variety of diseases. One factor contributing to rAAVs' success is the fact that a wide variety of tissue types can be transduced by different serotypes. However, one commonality amongst most serotypes is the high propensity for liver transduction when rAAVs are administered peripherally. One of the few exceptions is the naturally occurring clade F AAV hematopoietic stem cell 16 (AAVHSC16). AAVHSC16 represents an interesting capsid in that it shows minimal liver transduction when injected peripherally. For capsids other than AAVHSC16, targeting non-liver tissues via peripheral AAV injection represents a challenge due to the high liver transduction. Thus, there is a demand for liver-de-targeted rAAV vectors. The rational design of rAAV capsids relies on current knowledge to design improved capsids and represents one means of developing capsids with reduced liver transduction. Here, we utilized data from the AAVHSC16 capsid to rationally design four non-clade F rAAV capsids that result in reduced liver transduction following peripheral injection.

CD163+ macrophages restrain vascular calcification, promoting the development of high-risk plaque.

Vascular calcification (VC) is concomitant with atherosclerosis, yet it remains uncertain why rupture-prone high-risk plaques do not typically show extensive calcification. Intraplaque hemorrhage (IPH) deposits erythrocyte-derived cholesterol, enlarging the necrotic core and promoting high-risk plaque development. Pro-atherogenic CD163+ alternative macrophages engulf hemoglobin:haptoglobin (HH) complexes at IPH sites. However, their role in VC has never been examined to our knowledge. Here we show, in human arteries, the distribution of CD163+ macrophages correlated inversely with VC. In vitro experiments using vascular smooth muscle cells (VSMCs) cultured with HH-exposed human macrophage - M(Hb) - supernatant reduced calcification, while arteries from ApoE-/- CD163-/- mice showed greater VC. M(Hb) supernatant-exposed VSMCs showed activated NF-κB, while blocking NF-κB attenuated the anticalcific effect of M(Hb) on VSMCs. CD163+ macrophages altered VC through NF-κB-induced transcription of hyaluronan synthase (HAS), an enzyme that catalyzes the formation of the extracellular matrix glycosaminoglycan, hyaluronan, within VSMCs. M(Hb) supernatants enhanced HAS production in VSMCs, while knocking down HAS attenuated its anticalcific effect. NF-κB blockade in ApoE-/- mice reduced hyaluronan and increased VC. In human arteries, hyaluronan and HAS were increased in areas of CD163+ macrophage presence. Our findings highlight an important mechanism by which CD163+ macrophages inhibit VC through NF-κB-induced HAS augmentation and thus promote the high-risk plaque development.

Evaluation of a Multilevel Laboratory Stewardship Intervention Targeted to Cardiac and Thoracic Surgical Services at an Academic Medical Center.

CONTEXT.­: Unnecessary laboratory tests are ordered because of factors such as preselected orders on order sets, clinician habits, and trainee concerns. Excessive use of laboratory testing increases patient discomfort via unnecessary phlebotomy, contributes to iatrogenic anemia, increases risk of bloodstream infections, and increases the cost of care. OBJECTIVE.­: To address these concerns, we implemented a multilevel laboratory stewardship intervention to decrease unnecessary laboratory testing, measured by laboratory tests per day attributed to service, across 2 surgical divisions with high laboratory use. DESIGN.­: The multilevel intervention included 5 components: stakeholder engagement, provider education, computerized provider order entry modification, performance feedback, and culture change supported by leadership. The primary outcome of the study was laboratory tests ordered per patient-day. Secondary outcomes included the number of blood draws per patient-day, total lab-associated costs, length of stay, discharge to a nursing facility, 30-day readmissions, and deaths. A difference-in-differences analytic approach assessed the outcome measures in the intervention period, with other surgical services as controls. RESULTS.­: The primary outcome of laboratory tests per patient-day showed a significant decrease across both thoracic and cardiac surgery services, with between 1.5 and 2 fewer tests ordered per patient-day for both services and an estimated 20 000 fewer tests performed during the intervention period. Blood draws per patient-day were also significantly decreased on the thoracic surgery service but not for cardiac surgery. CONCLUSIONS.­: A multilevel laboratory stewardship intervention targeted to 2 surgical services resulted in a significant decrease in laboratory test use without negatively impacting length of stay, readmissions, or mortality.

Improving smoking history documentation in the electronic health record for lung cancer risk assessment and screening in primary care: A case study.

Improving risk factor documentation in the electronic health record (EHR) is important in order to determine patient eligibility for lung cancer screening. System-level prioritization combined with a clinic-level initiative can improve risk factor documentation rates. Multi-faceted interventions that include training, process improvement, data management, and continuous performance feedback are effective and can be integrated into existing workflows.

Colonic Basidiobolomycosis-An Unusual Presentation of Eosinophilic Intestinal Inflammation.

Basidiobolomycosis is a rare fungal disease caused by Basidiobolus ranarum. Involvement of the gastrointestinal tract is unusual and poses both a diagnostic and therapeutic challenge, as clinical signs are non-specific and predisposing risk factors are lacking. It can mimick inflammatory bowel disease, primary immunodeficiency, or a malignancy and should be considered in patients who do not respond to standard therapy. We present the case of a 22 months old boy with confirmed colonic Basidiobolomycosis, who presented with severe eosinophilic inflammation of the gastrointestinal tract. Panfungal PCR performed on DNA extracted directly from a tissue sample confirmed the presence of Basidiobolus. He made a full recovery with a combination of surgery and prolonged targeted antifungal medication.

Outcome according to subspecies following lung transplantation in cystic fibrosis pediatric patients infected with Mycobacterium abscessus.

BACKGROUND: Mycobacterium abscessus infection has been associated with variable outcomes following lung transplantation. M abscessus comprises three subspecies (M abscessus subsp abscessus, M abscessus subsp massiliense, and M abscessus subsp bolletii). We investigated whether lung transplantation outcome in cystic fibrosis (CF) patients in a single center was related to the M abscessus subspecies and genetic cluster. METHODS: CF patients with chronic M abscessus infection transplanted at Great Ormond Street Hospital between 2004 and 2017 were retrospectively examined. All M abscessus isolates were identified to subspecies level by polymerase chain reaction and sequencing. Genetic cluster was determined by variable number tandem repeat profiling and whole-genome sequencing (WGS), and sequence type inferred from WGS. RESULTS: Thirteen patients with chronic M abscessus infection underwent heart/lung or lung transplantation. Subspecies identification showed n = 1 with M abscessus bolletii, n = 5 with M abscessus massiliense, and n = 7 with M abscessus abscessus infection. Eight (62%) patients (one with M abscessus massiliense and seven with M abscessus abscessus) died post-lung transplant. The patient with M abscessus bolletii and three patients with M abscessus massiliense did well post-transplant. One patient with M abscessus massiliense is receiving ongoing treatment. CONCLUSIONS: Dramatically worse outcomes are observed in patients infected with M abscessus subspecies abscessus, the majority of whom were infected with ST-1 and ST-26 strains. Patients infected with other M abcsessus strains can have acceptable outcomes.

Standardizing nightly huddles with surgical residents and nurses to improve interdisciplinary communication and teamwork.

BACKGROUND: Clear and effective communication supports interdisciplinary teamwork and prevents adverse patient events. At our academic teaching hospital, poor communication between surgical residents and nurses was identified as a recurring problem, particularly on the inpatient general surgery night float rotation. METHODS: A standardized nightly huddle with surgical residents and nurses was developed and implemented as a resident-led quality improvement initiative on two acute care units. The huddle was evaluated with pre/post surveys of nurses and residents, as well as analysis of paging volume and rapid response events. RESULTS: Nightly huddles significantly improved nurses' perception of interdisciplinary teamwork and communication (p < 0.00005). With nightly huddles, significantly more nurses were able to identify and name the on-duty night float resident at the end of a 4-week rotation (p < 0.00005). Nurses perceived a positive impact on patient care and work environment. There were no changes in the number of nighttime pages or rapid responses. CONCLUSION: With night float rotations becoming a standard part of residency training, standardized huddles can enhance nighttime collaboration between residents and nurses.

Cross-transmission Is Not the Source of New Mycobacterium abscessus Infections in a Multicenter Cohort of Cystic Fibrosis Patients.

BACKGROUND: Mycobacterium abscessus is an extensively drug-resistant pathogen that causes pulmonary disease, particularly in cystic fibrosis (CF) patients. Identifying direct patient-to-patient transmission of M. abscessus is critically important in directing an infection control policy for the management of risk in CF patients. A variety of clinical labs have used molecular epidemiology to investigate transmission. However, there is still conflicting evidence as to how M. abscessus is acquired and whether cross-transmission occurs. Recently, labs have applied whole-genome sequencing (WGS) to investigate this further and, in this study, we investigated whether WGS can reliably identify cross-transmission in M. abscessus. METHODS: We retrospectively sequenced the whole genomes of 145 M. abscessus isolates from 62 patients, seen at 4 hospitals in 2 countries over 16 years. RESULTS: We have shown that a comparison of a fixed number of core single nucleotide variants alone cannot be used to infer cross-transmission in M. abscessus but does provide enough information to replace multiple existing molecular assays. We detected 1 episode of possible direct patient-to-patient transmission in a sibling pair. We found that patients acquired unique M. abscessus strains even after spending considerable time on the same wards with other M. abscessus-positive patients. CONCLUSIONS: This novel analysis has demonstrated that the majority of patients in this study have not acquired M. abscessus through direct patient-to-patient transmission or a common reservoir. Tracking transmission using WGS will only realize its full potential with proper environmental screening, as well as patient sampling.

Engineered bacteriophages for treatment of a patient with a disseminated drug-resistant Mycobacterium abscessus.

A 15-year-old patient with cystic fibrosis with a disseminated Mycobacterium abscessus infection was treated with a three-phage cocktail following bilateral lung transplantation. Effective lytic phage derivatives that efficiently kill the infectious M. abscessus strain were developed by genome engineering and forward genetics. Intravenous phage treatment was well tolerated and associated with objective clinical improvement, including sternal wound closure, improved liver function, and substantial resolution of infected skin nodules.

Children With Cystic Fibrosis Are Infected With Multiple Subpopulations of Mycobacterium abscessus With Different Antimicrobial Resistance Profiles.

BACKGROUND: Children with cystic fibrosis (CF) can develop life-threatening infections of Mycobacterium abscessus. These present a significant clinical challenge, particularly when the strains involved are resistant to antibiotics. Recent evidence of within-patient subclones of M. abscessus in adults with CF suggests the possibility that within-patient diversity may be relevant for the treatment of pediatric CF patients. METHODS: We performed whole-genome sequencing (WGS) on 32 isolates of M. abscessus that were taken from multiple body sites of 2 patients with CF who were undergoing treatment at Great Ormond Street Hospital, United Kingdom, in 2015. RESULTS: We found evidence of extensive diversity within patients over time. A clustering analysis of single nucleotide variants revealed that each patient harbored multiple subpopulations, which were differentially abundant between sputum, lung samples, chest wounds, and pleural fluid. The sputum isolates did not reflect the overall within-patient diversity and did not allow for the detection of subclones with mutations previously associated with macrolide resistance (rrl 2058/2059). Some variants were present at intermediate frequencies before the lung transplants. The time of the transplants coincided with extensive variation, suggesting that this event is particularly disruptive for the microbial community, but the transplants did not clear the M. abscessus infections and both patients died as a result of these infections. CONCLUSIONS: Isolates of M. abscessus from sputum do not always reflect the entire diversity present within the patient, which can include subclones with differing antimicrobial resistance profiles. An awareness of this phenotypic variability, with the sampling of multiple body sites in conjunction with WGS, may be necessary to ensure the best treatment for this vulnerable patient group.

Dosimetric impacts of endorectal balloon in CyberKnife stereotactic body radiation therapy (SBRT) for early-stage prostate cancer.

PURPOSE: In SBRT for prostate cancer, higher fractional dose to the rectum is a major toxicity concern due to using smaller PTV margin and hypofractionation. We investigate the dosimetric impact on rectum using endorectal balloon (ERB) in prostate SBRT. MATERIALS AND METHODS: Twenty prostate cancer patients were included in a retrospective study, ten with ERB and 10 without ERB. Optimized SBRT plans were generated on CyberKnife MultiPlan for 5 × 7.25 Gy to PTV under RTOG-0938 protocol for early-stage prostate cancer. For the rectum and the anterior half rectum, mean dose and percentage of volumes receiving 50%, 80%, 90%, and 100% prescription dose were compared. RESULTS: Using ERB, mean dose to the rectum was 62 cGy (P = 0.001) lower per fraction, and 50 cGy (P = 0.024) lower per fraction for the anterior half rectum. The average V50% , V80% , V90% , and V100% were lower by 9.9% (P = 0.001), 5.3% (P = 0.0002), 3.4% (P = 0.0002), and 1.2% (P = 0.005) for the rectum, and lower by 10.4% (P = 0.009), 8.3% (P = 0.0004), 5.4% (P = 0.0003), and 2.1% (P = 0.003) for the anterior half rectum. CONCLUSIONS: Significant reductions of dose to the rectum using ERB were observed. This may lead to improvement of the rectal toxicity profiles in prostate SBRT.

Large Sized Left Inferior Phrenic Artery and Parahiatal Type of Diaphragmatic Hernia Generating Confusion During Robotic Surgical Repair.

INTRODUCTION: As an advanced minimally invasive surgical procedure, the repair of the diaphragmatic hernia may sometimes be very challenging especially when the anatomy is unclear. MATERIALS AND METHODS: We are presenting a rare case of a parahiatal hernia defect repair where the understanding of the anatomy was complicated by the presence of an unusual large sized left inferior phrenic artery. The Da Vinci surgical platform was used to perform the entire procedure. Hernia sac dissection, identification of the crura, primary closure of the defect, and use of biologic mesh reinforcement were the main steps performed in the usual manner for hernia repair. In addition, the use of intraoperative ultrasound was of great utility to clarify the vascular anatomy. RESULTS: The additional time required for the intraoperative ultrasound and identification of the vascular anatomy has increased the duration of the procedure that otherwise was uneventful. The accurate identification of the anatomy allowed for a safe surgical outcome. The postoperative course was favorable and patient was free of symptoms at 1-month follow-up. CONCLUSION: The challenge of the repair of this rare, parahiatal type of diaphragmatic hernia where a large sized left inferior phrenic artery was also encountered was successfully mitigated by the use of the intraoperative Doppler ultrasound and by compliance with the basic steps of the procedure.

Repair of Morgagni Hernia in Adults with Primary Closure and Mesh Placement: First Robotic Experience.

INTRODUCTION: Morgagni hernia (MH) is an uncommon type of diaphragmatic hernia, especially in adults. Laparoscopic or thorascopic approaches have been described in adults. There are few reported cases using the Da Vinci robot in children and no previously described cases in adults. We report our early experience and technique using the robotic approach for MH repair in adults and its potential advantages. METHOD: Robotic repair of MH was performed in 3 female patients. Four trocars were used to gain access to the abdomen. The hernia contents were reduced, the sac excised, and the defect closed primarily. A 4 × 6 inch bioabsorbable coating mesh was used in 2 patients and a biologic mesh in 1 for reinforcement. RESULTS: Robotic repair of MH was technically successful in all 3 patients. The average operative time was 199.3 minutes, and difficult hernia exposure in one case caused prolonged surgical time. There were no intraoperative complications. Additional interventions, including a repair of a transverse colon serosal tear during the reduction of hernia contents, occurred in 1 patient. Two of the 3 female patients were discharged on postoperative day 1, whereas the other patient was discharged on postoperative day 3. There were no postoperative complications. CONCLUSION: Robotic MH repair is an alternative minimally invasive approach for adults that allows for precise sac excision and primary tension-free repair with mesh reinforcement.

Contemporary Hospitalization Rate Among Adults With Complex Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease are hospitalized at increasing rates in the Western world. Identification of rates of and risk factors for hospitalization is essential for research and improving patient outcomes. METHODS: We conducted a single-center retrospective analysis of patients with a primary diagnosis of tetralogy of Fallot (TOF), transposition of the great arteries (both d- and l-transposition of the great arteries [TGAs]), or single ventricle (SV). We investigated the rates of mortality, annual hospitalization, and patient-specific risk factors for unplanned cardiac hospitalization. RESULTS: Adult patients with complex congenital heart disease are hospitalized at a rate four to eight times greater than the general US population (P < .001). In addition, there are significant differences between the rates of hospitalization in TOF and TGA (0.39 and 0.41 hospitalizations per patient-year, respectively) and SV (0.72 hospitalizations per patient-year). The majority of excess hospitalizations in the study group were due to cardiac disease (P < .001 for all three groups). Risk factors for unplanned cardiac hospitalization in TOF included pulmonary atresia, depressed left ventricular and right ventricular ejection fraction, and smoking; in TGA, they included Ebstein malformation, surgeries other than primary repair, noncardiac diagnoses, atrial arrhythmias, atrioventricular nodal block, left ventricular ejection fraction, and smoking; and in SV, they included atrial arrhythmias and cyanosis. CONCLUSIONS: Patients born with complex congenital heart disease are hospitalized far more frequently than the general US population, primarily for cardiac-related illness. Future research should focus on confirming the present findings and on identification of strategies to improve outcomes in this growing group of patients.

Cutaneous Legionella longbeachae Infection in Immunosuppressed Woman, United Kingdom.

We report a rare case of cutaneous Legionella longbeachae infection in a patient receiving long-term corticosteroids for immune thrombocytopenia. Such infections cannot be identified by using Legionella urinary antigen testing but are commonly seen after exposure to commercial potting compost, particularly in immunocompromised patients.

Whole-genome sequencing and epidemiological analysis do not provide evidence for cross-transmission of mycobacterium abscessus in a cohort of pediatric cystic fibrosis patients.

BACKGROUND: Mycobacterium abscessus has emerged as a major pathogen in cystic fibrosis (CF) patients and has been associated with poor clinical outcomes, particularly following lung transplant. We investigated the acquisition of this bacterium in a cohort of pediatric CF patients. METHODS: Demographic and patient location data were used to uncover epidemiological links between patients with genetically related strains of M. abscessus that had been previously typed by variable-number tandem repeat profiling. Whole-genome sequencing was applied to 27 M. abscessus isolates from the 20 patients in this cohort to provide definitive data on the genetic relatedness of strains. RESULTS: Whole-genome sequencing data demonstrated that M. abscessus isolates from 16 patients were unrelated, differing by at least 34 single-nucleotide polymorphisms (SNPs) from any other isolate, suggesting that independent acquisition events have occurred. Only 2 clusters of very closely related (<25 SNPs) isolates from different patients were seen. The first cluster contained 8 isolates, differing by a maximum of 17 SNPs, from a sibling pair who had intense exposure to each other both inside and outside the hospital. The second cluster contained 3 isolates, differing by a maximum of 24 SNPs, from 2 individuals with no apparent epidemiological links. CONCLUSIONS: We have not demonstrated cross-transmission of M. abscessus within our hospital, except between 1 sibling pair. Alternative routes of acquisition of M. abscessus infection, in particular the environment, require further investigation.

Regulatory B cells are induced by gut microbiota-driven interleukin-1ß and interleukin-6 production.

Regulatory B cells (Breg cells) differentiate in response to inflammation and subsequently restrain excessive immune responses via the release of interleukin-10 (IL-10). However, the precise inflammatory signals governing their differentiation remain to be elucidated. Here we show that the gut microbiota promotes the differentiation of Breg cells in the spleen as well as in the mesenteric lymph nodes. Perturbation of the gut microbiome imposed either by antibiotic treatment or by changes in the sterility of housing conditions reduces the number and function of Breg cells. Following the induction of arthritis, IL-1ß and IL-6 are produced only in conventionally housed mice and both cytokines directly promote Breg cell differentiation and IL-10 production. Mice lacking IL-6 receptor (IL-6R) or IL-1 receptor 1 (IL-1R1) specifically on B cells have a reduced number of IL-10-producing B cells and develop exacerbated arthritis compared to control animals. Thus, in response to inflammatory signals induced by both the gut flora and arthritis, Breg cells increase in number and restrain excessive inflammation.

Mycobacterium abscessus infection in cystic fibrosis: molecular typing and clinical outcomes.

Mycobacterium abscessus is a significant pathogen in the cystic fibrosis patient population. PCR amplification and sequencing can provide accurate subspecies identification, and can predict macrolide susceptibility, which is becoming increasingly important for patient management. Molecular techniques for further typing of isolates provide tools for the ongoing investigations into the clinical impact of particular M. abscessus strains. Whole-genome sequencing is likely to be the only technique that provides sufficient resolution for investigating transmission events between patients.