Uptake and transfection efficiency of PEGylated cationic liposome–DNA complexes with and without RGD-tagging

Steric stabilization of cationic liposome–DNA (CL–DNA) complexes is required for in vivo applications such as gene therapy. PEGylation (PEG: poly(ethylene glycol)) of CL–DNA complexes by addition of PEG2000-lipids yields sterically stabilized nanoparticles but strongly reduces their gene delivery efficacy. PEGylation-induced weakening of the electrostatic binding of CL–DNA nanoparticles to cells (leading to reduced uptake) has been considered as a possible cause, but experimental results have been ambiguous. Using quantitative live-cell imaging in vitro, we have investigated cell attachment and uptake of PEGylated CL–DNA nanoparticles with and without a custom synthesized RGD-peptide grafted to the distal ends of PEG2000-lipids. The RGD-tagged nanoparticles exhibit strongly increased cellular attachment as well as uptake compared to nanoparticles without grafted peptide. Transfection efficiency of RGD-tagged PEGylated CL–DNA NPs increases by about an order of magnitude between NPs with low and high membrane charge density (σ_M; the average charge per unit area of the membrane; controlled by the molar ratio of cationic to neutral lipid), even though imaging data show that uptake of RGD-tagged particles is only slightly enhanced by high σ_M. This suggests that endosomal escape and, as a result, transfection efficiency of RGD-tagged NPs is facilitated by high σ_M. We present a model describing the interactions between PEGylated CL–DNA nanoparticles and the anionic cell membrane which shows how the PEG grafting density and membrane charge density affect adhesion of nanoparticles to the cell surface.     

Pevonedistat and azacitidine upregulate NOXA (PMAIP1) to increase sensitivity to venetoclax in preclinical models of acute myeloid leukemia

Dysregulation of apoptotic machinery is one mechanism by which acute myeloid leukemia (AML) acquires a clonal survival advantage. B-cell lymphoma protein-2 (BCL2) overexpression is a common feature in hematologic malignancies. The selective BCL2 inhibitor, venetoclax (VEN) is used in combination with azacitidine (AZA), a DNAmethyltransferase inhibitor (DNMTi), to treat patients with AML. Despite promising response rates to VEN/AZA, resistance to the agent is common. One identified mechanism of resistance is the upregulation of myeloid cell leukemia-1 protein (MCL1). Pevonedistat (PEV), a novel agent that inhibits NEDD8-activating enzyme, and AZA both upregulate NOXA (PMAIP1), a BCL2 family protein that competes with effector molecules at the BH3 binding site of MCL1. We demonstrate that PEV/AZA combination induces NOXA to a greater degree than either PEV or AZA alone, which enhances VEN-mediated apoptosis. Herein, using AML cell lines and primary AML patient samples ex vivo, including in cells with genetic alterations linked to treatment resistance, we demonstrate robust activity of the PEV/VEN/AZA triplet. These findings were corroborated in preclinical systemic engrafted models of AML. Collectively, these results provide rational for combining PEV/VEN/AZA as a novel therapeutic approach in overcoming AML resistance in current therapies.     

Association of Race and Neighborhood Disadvantage with Patient Engagement in a Home-Based COVID-19 Remote Monitoring Program

BackgroundCOVID-positive outpatients may benefit from remote monitoring, but such a program often relies on smartphone apps. This may introduce racial and socio-economic barriers to participation. Offering multiple methods for participation may address these barriers.Objectives(1) To examine associations of race and neighborhood disadvantage with patient retention in a monitoring program offering two participation methods. (2) To measure the association of the program with emergency department visits and hospital admissions.DesignRetrospective propensity-matched cohort study.ParticipantsCOVID-positive outpatients at a single university-affiliated healthcare system and propensity-matched controls.InterventionsA home monitoring program providing daily symptom tracking via patient portal app or telephone calls.Main MeasuresAmong program enrollees, retention (until 14 days, symptom resolution, or hospital admission) by race and neighborhood disadvantage, with stratification by program arm. In enrollees versus matched controls, emergency department utilization and hospital admission within 30 days.Key ResultsThere were 7592 enrolled patients and 9710 matched controls. Black enrollees chose the telephone arm more frequently than White enrollees (68% versus 44%, p = 0.009), as did those from more versus less disadvantaged neighborhoods (59% versus 43%, p = 0.02). Retention was similar in Black enrollees and White enrollees (63% versus 62%, p = 0.76) and in more versus less disadvantaged neighborhoods (63% versus 62%, p = 0.44). When stratified by program arm, Black enrollees had lower retention than White enrollees in the app arm (49% versus 55%, p = 0.01), but not in the telephone arm (69% versus 71%, p = 0.12). Compared to controls, enrollees more frequently visited the emergency department (HR 1.71 [95% CI 1.56–1.87]) and were admitted to the hospital (HR 1.16 [95% CI 1.02–1.31]).ConclusionsIn a COVID-19 remote patient monitoring program, Black enrollees preferentially selected, and had higher retention in, telephone- over app-based monitoring. As a result, overall retention was similar between races. Remote monitoring programs with multiple modes may reduce barriers to participation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-021-07207-4.KEY WORDS: ambulatory monitoring, COVID-19, race factors, facilities and services utilization     

Fast 3D functional magnetic resonance imaging at 1.5 T with spiral acquisition

A new method to perform rapid 3D fMRI in human brain is introduced and evaluated in normal subjects, on a standard clinical scanner at 1.5 Tesla. The method combines a highly stable gradient echo technique with a spiral scan method, to detect brain activation related changes in blood oxygenation with high sensitivity. A motor activation paradigm with a duration of less than 5 min, performed on 10 subjects, consistently showed significant changes in signal intensity in the area of the motor cortex. In all subjects, these changes survived high statistical thresholds.     

Arthroscopic decompression of a ganglion cyst causing suprascapular nerve compression

Ganglion cysts causing suprascapular nerve compression are an uncommon cause of suprascapular nerve compression. The advent of magnetic resonance imaging (MRI) and its application in patients with shoulder pain has improved the ability to diagnose cystic lesions causing extrinsic compression of the suprascapular nerve. Traditionally, treatment of suprascapular nerve compression by a ganglion cyst has required open cyst excision through either a deltoid and infraspinatus muscle takedown or a muscle splitting approach. We present three cases of suprascapular nerve compression by a ganglion cyst in which the cyst was decompressed arthroscopically. In each case the patient's symptoms resolved after arthroscopic cyst decompression, and a postoperative MRI does not demonstrate reaccumulation of the cyst fluid. Arthroscopic ganglion cyst decompression is a well-tolerated approach to this problem that avoids the morbidity of an open surgical procedure. The absence of recurrent cyst formation combined with resolution of the symptoms attests to the success of this method.     

Donating eggs for research--should the HFEA reconsider its policy on payments to egg donors?

The Human Fertilisation and Embryology Authority (HFEA) policy on payments to egg donors states that an 'expense neutral' approach is to be adopted, regardless of whether the donation is for treatment or research purposes. In this article the HFEA case against compensatory payments for egg donors will be examined as will the expectation that women should donate eggs for medical research without the offer of financial recompense. This will be shown to sit uneasily alongside existing policy that both permits indirect payments by way of egg-sharing schemes and allows healthy participants in research trials to receive financial remuneration for their contribution to medical science. It will be concluded that the HFEA should reconsider its policy on paying women to donate eggs for medical research.     

Anesthesia Technique and Outcomes of Endovascular Aneurysm Repair

Anesthetic techniques vary widely in the endovascular repair of abdominal aortic aneurysms (EVAR). Previous studies have demonstrated the feasibility of using local anesthesia. However, the ideal anesthetic technique has not been determined. This study examines whether anesthesic technique influences the outcomes of EVAR. Data regarding demographics, risk factors, procedural characteristics, recovery characteristics, treatment complications, acute (<30 day) medical complications, mortality, and anesthetic type were prospectively collected during the AneuRx phase II aortic endograft trial. Patient cohorts receiving general, regional, or local anesthesia were compared. From 1997 to 1998, 424 patients underwent EVAR at 13 sites using the AneuRx Bifurcated endograft. There were 279 patients in the general anesthesia group, 95 patients in the regional group, and 50 patients in the local group. Risk factors were similar. There were no significant differences in age, gender, American Society of Anesthesiologists grade, length of anesthesia, branch artery occlusions, proximal endoleaks, failed implants, or open surgical conversions. Cardiac, renal, and wound-healing complications were all lower in the local group. Mortality was equivalent among the three groups. (p > 0.05, ANOVA). From these results we concluded that EVAR with local anesthesia is a safe and efficacious method that may reduce recovery times and postoperative medical morbidity compared to use of genera1 or spinal/epidural anesthesia.