Evaluation of the Catheter Clamp over Hydrophilic Guide Wire Central Venous Catheter Exchange Technique for Air Embolism Prophylaxis in an In Vitro Model.

PURPOSE: To develop a reproducible in vitro model simulating central venous catheter (CVC) exchange with high potential for air embolization and test the hypothesis that a closed catheter clamp over hydrophilic guide wire exchange technique will significantly reduce the volume of air introduced during CVC exchange. MATERIALS AND METHODS: The model consisted of a 16-F valved sheath, 240-mL container, and pressure transducer submerged in water in a 1,200-mL suction canister system. Continuous wall suction was applied to the canister to maintain negative pressure at -7 mm Hg or -11 mm Hg. Each trial consisted of 0.035-inch hydrophilic guide wire introduction, over-the-wire catheter exchange, and wire removal following clinical protocol. A total of 256 trials were performed, 128 trials at each pressure with the catheter clamp open (n = 64) or closed (n = 64) around the hydrophilic guide wire. RESULTS: There was a statistically significant lower volume of air introduced with closed clamp over-the-wire exchanges than with open clamp exchanges at both pressures (2-tailed t-test, P < .001). At -7 mm Hg, a mean of 48.0 mL (SD ± 9.3) of air was introduced with open clamp and 20.6 mL (SD ± 4.7) of air was introduced with closed clamp. At -11 mm Hg, 97.8 mL (SD ± 11.9) of air was introduced with open clamp and 37.8 mL (SD ± 6.3) of air was introduced with closed clamp. CONCLUSIONS: This study demonstrated the use of a reproducible in vitro model mimicking conditions causing air embolism during CVC exchange. Results showed that CVC exchange using closed catheter clamp over hydrophilic guide wire exchange technique significantly reduced the volume of air introduced per exchange.

Biliary Leaks: Multidisciplinary Approach to Diagnosis and Treatment.

Bile leaks arise from various causes such as trauma, complications after hepatobiliary surgery, and intrahepatic malignancies or their associated liver-directed treatments. Bile leaks can result in significant morbidity and mortality. Delayed diagnosis is not uncommon due to nonspecific manifestations; therefore, a high clinical suspicion is needed. A multidisciplinary approach for treatment of biliary leaks with prompt referral to tertiary care centers with experienced hepatobiliary surgeons, advanced endoscopists, and interventional radiologists is needed to address these challenging complications. Management of biliary leaks can range from conservative management to open surgical repair. Minimally invasive procedures play a crucial role in biliary leak treatment, and the interventional radiologist can help guide appropriate management on the basis of a clear understanding of the pathophysiology of biliary leaks and a current knowledge of the armamentarium of treatment options. In most cases, a simple diversion of bile to decompress the biliary system may prove effective. However, persistent and high-output biliary leaks require delineation of the source with tailored treatment options to control the leak. This may be done by additional diversions, occluding the source, reestablishing connections, or using a combination of therapies to bridge to more definitive surgical interventions. The authors describe the different treatment options and emphasize the role of interventional radiology. ©RSNA, 2024.

Creation of an Ex Vivo Renal Perfusion Model to Investigate Microwave Ablation.

This study hypothesized that an ex vivo renal perfusion model can create smaller microwave ablation (MWA) measurements during perfused states compared with nonperfused states across multiple device settings. Nine bovine kidneys, a fluoroscopic compatible perfusion model, and a commercially-available clinical MWA system were used to perform 72 ablations (36 perfused and 36 nonperfused) at 9 different device settings. Comparing perfused and nonperfused ablations at each device setting, significant differences in volume existed for 6 of 9 settings (P < .05). Collapsed across time settings, the ablation volumes by power were the following (perfused and nonperfused, P value): 60 W, 2.3 cm3 ± 1.0 and 7.2 cm3 ± 2.7, P < .001; 100 W, 5.4 cm3 ± 2.1 and 11.5 cm3 ± 5.6, P < .01; and 140 W, 11.2 cm3 ± 3.7 and 18.7 cm3 ± 6.3, P < .01. Applied power correlated with ablation volume: perfused, 0.021 cm3/W and R = 0.462, P = .004, and nonperfused, 0.029 cm3/W and R = 0.565, P < .001. These results support that an ex vivo perfused organ system can evaluate MWA systems and demonstrate heat sink perfusion effects of decreased ablation size.

Can Dynamic Contrast-Enhanced CT Quantify Perfusion in a Stimulated Muscle of Limited Size? A Rat Model.

BACKGROUND: Muscle injury may result in damage to the vasculature, rendering it unable to meet the metabolic demands of muscle regeneration and healing. Therefore, therapies frequently aim to maintain, restore, or improve blood supply to the injured muscle. Although there are several options to assess the vascular outcomes of these therapies, few are capable of spatially assessing perfusion in large volumes of tissue. QUESTIONS/PURPOSES: Can dynamic contrast-enhanced CT (DCE-CT) imaging acquired with a clinical CT scanner be used in a rat model to quantify perfusion in the anterior tibialis muscle at spatially relevant volumes, as assessed by (1) the blood flow rate and tissue blood volume in the muscle after three levels of muscle stimulation (low, medium, and maximum) relative to baseline as determined by the non-stimulated contralateral leg; and (2) how do these measurements compare with those obtained by the more standard approach of microsphere perfusion? METHODS: The right anterior tibialis muscles of adult male Sprague Dawley rats were randomized to low- (n = 10), medium- (n = 6), or maximum- (n = 3) level (duty cycles of 2.5%, 5.0%, and 20%, respectively) nerve electrode coupled muscle stimulation directly followed by DCE-CT imaging. Tissue blood flow and blood volume maps were created using commercial software and volumetrically measured using NIH software. Although differences in blood flow were detectable across the studied levels of muscle stimulation, a review of the evidence suggested the absolute blood flow quantified was underestimated. Therefore, at a later date, a separate set of adult male Sprague Dawley rats were randomized for microsphere perfusion (n = 7) to define blood flow in the animal model with an accepted standard. With this technique, intra-arterial particles sized to freely flow in blood but large enough to lodge in tissue capillaries were injected. Simultaneously, blood sampling at a fixed flow rate was simultaneously performed to provide a fixed blood flow rate sample. The tissues of interest were then explanted and assessed for the total number of particles per tissue volume. Tissue blood flow rate was then calculated based on the particle count ratio within the reference sample. Note that a tissue's blood volume cannot be calculated with this method. Comparison analysis to the non-stimulated baseline leg was performed using two-tailed paired student t-test. An ANOVA was used to compare difference between stimulation groups. RESULTS: DCE-CT measured (mean ± SD) increasing tissue blood flow differences in stimulated anterior tibialis muscle at 2.5% duty cycle (32 ± 5 cc/100 cc/min), 5.0% duty cycle (46 ± 13 cc/100 cc/min), and 20% duty cycle (73 ± 3 cc/100 cc/min) compared with the paired contralateral non-stimulated anterior tibialis muscle (10 ± 2 cc/100 cc/min, mean difference 21 cc/100 cc/min [95% CI 17.08 to 25.69]; 9 ± 1 cc/100 cc/min, mean difference 37 cc/100 cc/min [95% CI 23.06 to 50.11]; and 11 ± 2 cc/100 cc/min, mean difference 62 cc/100 cc/min [95% CI 53.67 to 70.03]; all p < 0.001). Similarly, DCE-CT showed increasing differences in tissue blood volumes within the stimulated anterior tibialis muscle at 2.5% duty cycle (23.2 ± 4.2 cc/100 cc), 5.0% duty cycle (39.2 ± 7.2 cc/100 cc), and 20% duty cycle (52.5 ± 13.1 cc/100 cc) compared with the paired contralateral non-stimulated anterior tibialis muscle (3.4 ± 0.7 cc/100 cc, mean difference 19.8 cc/100 cc [95% CI 16.46 to 23.20]; p < 0.001; 3.5 ± 0.4 cc/100 cc, mean difference 35.7 cc/100 cc [95% CI 28.44 to 43.00]; p < 0.001; and 4.2 ± 1.3 cc/100 cc, mean difference 48.3 cc/100 cc [95% CI 17.86 to 78.77]; p = 0.010). Microsphere perfusion measurements also showed an increasing difference in tissue blood flow in the stimulated anterior tibialis muscle at 2.5% duty cycle (62 ± 43 cc/100 cc/min), 5.0% duty cycle (89 ± 52 cc/100 cc/min), and 20% duty cycle (313 ± 269 cc/100 cc/min) compared with the paired contralateral non-stimulated anterior tibialis muscle (8 ± 4 cc/100 cc/min, mean difference 55 cc/100 cc/min [95% CI 15.49 to 94.24]; p = 0.007; 9 ± 9 cc/100 cc/min, mean difference 79 cc/100 cc/min [95% CI 33.83 to 125.09]; p = 0.003; and 18 ± 18 cc/100 cc/min, mean difference 295 cc/100 cc/min [95% CI 8.45 to 580.87]; p = 0.023). Qualitative comparison between the methods suggests that DCE-CT values underestimate tissue blood flow with a post-hoc ANOVA showing DCE-CT blood flow values within the 2.5% duty cycle group (32 ± 5 cc/100 cc/min) to be less than the microsphere perfusion value (62 ± 43 cc/100 cc/min) with a mean difference of 31 cc/100 cc/min (95% CI 2.46 to 60.23; p = 0.035). CONCLUSIONS: DCE-CT using a clinical scanner is a feasible modality to measure incremental changes of blood flow and tissue blood volume within a spatially challenged small animal model. Care should be taken in studies where true blood flow values are needed, as this particular small-volume muscle model suggests true blood flow is underestimated using the specific adaptions of DCE-CT acquisition and image processing chosen. CLINICAL RELEVANCE: CT perfusion is a clinically available modality allowing for translation of science from bench to bedside. Adapting the modality to fit small animal models that are relevant to muscle healing may hasten time to clinical utility.

Macular Carotenoids, Aerobic Fitness, and Central Adiposity Are Associated Differentially with Hippocampal-Dependent Relational Memory in Preadolescent Children.

OBJECTIVES: To examine the associations of macular pigment carotenoids (lutein, meso-zeaxanthin, and zeaxanthin), aerobic fitness, and central adiposity with hippocampal-dependent relational memory in prepubescent children. STUDY DESIGN: Children between 7 and 10 years of age (n = 40) completed a task designed to assess relational memory performance and participated in aerobic fitness, adiposity, and macular pigment optical density (MPOD) assessment. Aerobic fitness was assessed via a modified Balke treadmill protocol designed to measure maximal oxygen volume. Central adiposity was assessed via dual-energy x-ray absorptiometry. MPOD was measured psychophysically by the use of customized heterochromatic flicker photometry. Statistical analyses included correlations and hierarchical linear regression. RESULTS: Aerobic fitness and MPOD were associated negatively with relational memory errors (P < .01), whereas central adiposity was associated positively with relational memory errors (P < .05). Hierarchical regression analysis revealed that MPOD accounted for a significant amount of the variance in relational memory performance even after we accounted for aerobic fitness (ß = -0.388, P = .007). CONCLUSIONS: Even after we adjusted for aerobic fitness and central adiposity, factors known to relate to hippocampal-dependent memory, MPOD positively and significantly predicted hippocampal-dependent memory performance. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01619826.

Implementation of a Mini-CEX Requirement Across All Third-Year Clerkships.

PROBLEM: Direct observation of medical students performing clinical tasks, such as eliciting a patient history or examining a patient, and the provision of feedback, are foundational to student improvement but have been reported to occur infrequently. The mini clinical evaluation exercise (mini-CEX) is a tool that can facilitate direct observation and feedback. This study assessed the impact of a mini-CEX requirement across all 3rd-year clerkships on student report of direct observation by faculty and objectively measured clinical skills. INTERVENTION: A mini-CEX requirement across all 3rd-year clerkships was implemented in the 2012-2013 academic year. The impact of the mini-CEX requirement on student report of direct observation was assessed by end-of-clerkship surveys and Association of American Medical Colleges (AAMC) Graduation Questionnaire (GQ) items on direct observation. The impact on students' clinical skills was assessed by a summative Objective Structured Clinical Examination (OSCE). Pre/post comparisons were assessed with chi-square and Fisher's exact tests. CONTEXT: A mini-CEX requirement had been in place for the internal medicine clerkship, and student reports of direct observation were historically higher for the internal medicine clerkship than for other clerkships. Faculty, residents, and students at each of the clinical sites across all 6 clerkships were oriented to the use of the mini-CEX; the feasibility of its use during usual patient interaction settings and the importance of direct observation and feedback for student improvement were emphasized during these sessions. OUTCOME: Adherence to the mini-CEX requirement was high: 92% of required forms were completed, and 78% of completed forms indicated that specific feedback was given. The proportion of students reporting direct observation of physical examination significantly increased in all clerkships, with the largest relative increase occurring in surgery (from 49% to 87%), χ2(1, N = 225) = 37.70, p < .0001. Significant increases were seen in faculty observation of history taking in pediatrics, surgery, and psychiatry. Direct observation rates also increased on the AAMC GQ items for history taking and physical exam for all clerkships. Failures on the summative OSCE decreased from 12% preintervention to 2% postintervention (p = .0046). LESSONS LEARNED: Institution of a mini-CEX requirement was feasible across all 3rd-year clerkships and was associated with a significant increase in student report of direct observation by faculty and a decrease in summative OSCE failure rates.

Origin of amphibian and avian chromosomes by fission, fusion, and retention of ancestral chromosomes.

Amphibian genomes differ greatly in DNA content and chromosome size, morphology, and number. Investigations of this diversity are needed to identify mechanisms that have shaped the evolution of vertebrate genomes. We used comparative mapping to investigate the organization of genes in the Mexican axolotl (Ambystoma mexicanum), a species that presents relatively few chromosomes (n = 14) and a gigantic genome (>20 pg/N). We show extensive conservation of synteny between Ambystoma, chicken, and human, and a positive correlation between the length of conserved segments and genome size. Ambystoma segments are estimated to be four to 51 times longer than homologous human and chicken segments. Strikingly, genes demarking the structures of 28 chicken chromosomes are ordered among linkage groups defining the Ambystoma genome, and we show that these same chromosomal segments are also conserved in a distantly related anuran amphibian (Xenopus tropicalis). Using linkage relationships from the amphibian maps, we predict that three chicken chromosomes originated by fusion, nine to 14 originated by fission, and 12-17 evolved directly from ancestral tetrapod chromosomes. We further show that some ancestral segments were fused prior to the divergence of salamanders and anurans, while others fused independently and randomly as chromosome numbers were reduced in lineages leading to Ambystoma and Xenopus. The maintenance of gene order relationships between chromosomal segments that have greatly expanded and contracted in salamander and chicken genomes, respectively, suggests selection to maintain synteny relationships and/or extremely low rates of chromosomal rearrangement. Overall, the results demonstrate the value of data from diverse, amphibian genomes in studies of vertebrate genome evolution.

Salamander Hox clusters contain repetitive DNA and expanded non-coding regions: a typical Hox structure for non-mammalian tetrapod vertebrates?

Hox genes encode transcription factors that regulate embryonic and post-embryonic developmental processes. The expression of Hox genes is regulated in part by the tight, spatial arrangement of conserved coding and non-coding sequences. The potential for evolutionary changes in Hox cluster structure is thought to be low among vertebrates; however, recent studies of a few non-mammalian taxa suggest greater variation than originally thought. Using next generation sequencing of large genomic fragments (>100 kb) from the red spotted newt (Notophthalamus viridescens), we found that the arrangement of Hox cluster genes was conserved relative to orthologous regions from other vertebrates, but the length of introns and intergenic regions varied. In particular, the distance between hoxd13 and hoxd11 is longer in newt than orthologous regions from vertebrate species with expanded Hox clusters and is predicted to exceed the length of the entire HoxD clusters (hoxd13-hoxd4) of humans, mice, and frogs. Many repetitive DNA sequences were identified for newt Hox clusters, including an enrichment of DNA transposon-like sequences relative to non-coding genomic fragments. Our results suggest that Hox cluster expansion and transposon accumulation are common features of non-mammalian tetrapod vertebrates.

Generation of precision preclinical cancer models using regulated in vivo base editing.

Although single-nucleotide variants (SNVs) make up the majority of cancer-associated genetic changes and have been comprehensively catalogued, little is known about their impact on tumor initiation and progression. To enable the functional interrogation of cancer-associated SNVs, we developed a mouse system for temporal and regulatable in vivo base editing. The inducible base editing (iBE) mouse carries a single expression-optimized cytosine base editor transgene under the control of a tetracycline response element and enables robust, doxycycline-dependent expression across a broad range of tissues in vivo. Combined with plasmid-based or synthetic guide RNAs, iBE drives efficient engineering of individual or multiple SNVs in intestinal, lung and pancreatic organoids. Temporal regulation of base editor activity allows controlled sequential genome editing ex vivo and in vivo, and delivery of sgRNAs directly to target tissues facilitates generation of in situ preclinical cancer models.

Pharmacist-led workshops to enhance pharmacotherapy knowledge for medical students.

BACKGROUND: Graduating medical students have reported concern regarding inadequate training in pharmacotherapy. Teaching by clinical pharmacists may improve medical students' pharmacotherapy knowledge. PURPOSE: To assess the impact of pharmacist led workshops on 4th year medical students' knowledge of pharmacotherapy and satisfaction. METHODS: Senior medical students enrolled in intensive care unit rotations at a US medical school were randomized to an intervention of pharmacist led case-based workshops or a control group without an explicit pharmacotherapy curriculum. Intervention group students attended four weekly 1-hour workshops that covered topics in pharmacokinetics, pharmacodynamics, drug interactions and toxicity. A multiple-choice test of clinical vignettes assessed students' knowledge of pharmacotherapy. An end of clerkship survey assessed student satisfaction with teaching. RESULTS: Of 176 medical students eligible, 148 agreed to participate and were randomized to the intervention (n = 63) or control groups (n = 85). Student satisfaction with pharmacist led workshops was high. End of clerkship performance on clinical vignettes (minimum score 0, maximum 100) was similar between the groups (mean score 47 (SD = 12.2) for intervention vs 44 (SD = 13.0) for control group, p = 0.16). On end of clerkship survey, only 8% of control group students agreed or strongly agreed that the standard curriculum provided sufficient teaching in pharmacotherapy. The majority of students (82%) felt that pharmacotherapy should be taught formally in the clinical years. CONCLUSION: Pharmacist led workshops on pharmacotherapy were well received by senior medical students but did not improve performance on a test of pharmacotherapy knowledge. Further study is needed to define optimal strategies for improving medical students' pharmacotherapy knowledge.

Effect of proteasome inhibitor 1 on wound healing: a potential scar prevention therapy.

UNLABELLED: In vitro and in vivo assessments suggest that proteasome inhibitors may be useful for modulating wound healing. METHODS: Proteasome Inhibitor I was used to assess the potential utility of proteasome inhibitors in improving wound healing in a standard rat model. Bilateral, 6 cm incisions were made 1 cm lateral to the spine of adult male Sprague Dawley rats. Animals were randomly assigned to 1 of 3 groups: no treatment (n = 15), low concentration (1% w/v, n = 15), or high concentration (5% w/v, n = 15). Treatments were applied to the left side incision at 0 hours, 24 hours, and 48 hours. Right-side incisionsreceived a vehicle, dimethyl sulfoxide, alone and independent of the assigned group, serving as both external and internal controls. Rats were sacrificed at days 7, 14, and 28 (n = 5 per group) and wounds subjected to mechanical testing and histology. RESULTS: No significant intergroup difference existed at 7 and 14 days. On day 28, a dosedependent increase in tensile strength with increasing Proteasome Inhibitor I was observed. CONCLUSION: Results suggest dimethyl sulfoxide was not the ideal vehicle and additional improvement may be realized by optimizing the delivery method.

Drag-and-drop genome insertion of large sequences without double-strand DNA cleavage using CRISPR-directed integrases.

Programmable genome integration of large, diverse DNA cargo without DNA repair of exposed DNA double-strand breaks remains an unsolved challenge in genome editing. We present programmable addition via site-specific targeting elements (PASTE), which uses a CRISPR-Cas9 nickase fused to both a reverse transcriptase and serine integrase for targeted genomic recruitment and integration of desired payloads. We demonstrate integration of sequences as large as ~36 kilobases at multiple genomic loci across three human cell lines, primary T cells and non-dividing primary human hepatocytes. To augment PASTE, we discovered 25,614 serine integrases and cognate attachment sites from metagenomes and engineered orthologs with higher activity and shorter recognition sequences for efficient programmable integration. PASTE has editing efficiencies similar to or exceeding those of homology-directed repair and non-homologous end joining-based methods, with activity in non-dividing cells and in vivo with fewer detectable off-target events. PASTE expands the capabilities of genome editing by allowing large, multiplexed gene insertion without reliance on DNA repair pathways.

Effect of endothelial differentiated adipose-derived stem cells on vascularity and osteogenesis in poly(D,L-lactide) scaffolds in vivo.

Prevascularization of engineered bony constructs can potentially improve in vivo viability. However, the effect of endothelial cells on osteogenesis is unknown when placed in poly(D,L-lactide) (PLA) scaffolds alone. Adipose-derived stem cells (ASCs) have the ability to differentiate into both osteoblasts and endothelial cells by culture in specific media. We hypothesized that ASC-derived endothelial cells would improve vascularity with minimal contribution to bone formation when placed in scaffold alone. ASCs were successfully differentiated into endothelial cells (ASC-Endo) and osteoblasts (ASC-Osteo) using media supplemented with vascular endothelial growth factor and bone morphogenic protein 2, respectively. Tissue-engineered constructs were created with PLA matrices containing no cells (control), undifferentiated ASCs (ASCs), osteogenic-differentiated ASCs (ASC-Osteo), or endothelial differentiated ASCs (ASC-Endo), and these constructs were evaluated in critical-size Lewis rat calvarial defect model (n = 34). Eight weeks after implantation, the bone volume and microvessel population of bony constructs were evaluated by micro-computed tomography analysis and histologic staining. Bone volumes for ASCs and ASC-Osteo constructs, 0.7 and 0.91 mm(3), respectively, were statistically greater than that for ASC-Endo, 0.28 mm(3) (P < 0.05). There was no statistical difference between the PLA control (0.5 mm(3)) and ASC-Endo (0.28 mm(3)) constructs in bone formation. The percent area of microvessels within constructs was highest in the ASC-Endo group, although it did not reach statistical significance (0.065). Prevascularization of PLA scaffold with ASC-Endo cells will not increase bone formation by itself but may be used as a cell source for improving vascularization and potentially improving existing osteoblast function.

Broad-spectrum CRISPR-mediated inhibition of SARS-CoV-2 variants and endemic coronaviruses in vitro.

A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution and mutations. Here we demonstrate that CRISPR-Cas13d offers a broad-spectrum antiviral (BSA) to inhibit many SARS-CoV-2 variants and diverse human coronavirus strains with >99% reduction of the viral titer. We show that Cas13d-mediated coronavirus inhibition is dependent on the crRNA cellular spatial colocalization with Cas13d and target viral RNA. Cas13d can significantly enhance the therapeutic effects of diverse small molecule drugs against coronaviruses for prophylaxis or treatment purposes, and the best combination reduced viral titer by over four orders of magnitude. Using lipid nanoparticle-mediated RNA delivery, we demonstrate that the Cas13d system can effectively treat infection from multiple variants of coronavirus, including Omicron SARS-CoV-2, in human primary airway epithelium air-liquid interface (ALI) cultures. Our study establishes CRISPR-Cas13 as a BSA which is highly complementary to existing vaccination and antiviral treatment strategies.

In vivo performance of bilayer hydroxyapatite scaffolds for bone tissue regeneration in the rabbit radius.

The objective of this study was to investigate the in vivo biomechanical performance of bone defects implanted with novel bilayer hydroxyapatite (HAp) scaffolds that mimic the cortical and cancellous organization of bone. The scaffolds maintained architectural continuity in a rabbit radius segmental defect model and were compared to an untreated defect group (negative control) and autologous bone grafts (positive control). Micro-CT evaluations indicated total bone and scaffold volume in the experimental group was significantly greater than the defect group but lesser than the autologous bone graft treatment. The flexural toughness of the scaffold and the autograft groups was significantly greater than the flexural toughness of the defect group. Interestingly, the absolute density of the bone mineral as well as calcium to phosphorus (Ca/P) ratio in that mineral for the scaffold and autograft contralateral bones was significantly higher than those for the defect contralaterals suggesting that the scaffolds contributed to calcium homeostasis. It was concluded from this study that new bone regenerated in the bilayer HAp scaffolds was comparable to the empty defects and while the HAp scaffolds provided significant increase in modulus when compared to empty defect and their flexural toughness was comparable to autografts after 8 weeks of implantation.

Comparative outcomes of Inferior Vena Cava filters placed at bedside using digital radiography versus conventional fluoroscopy.

PURPOSE: To retrospectively assess the outcomes of Inferior Vena Cava (IVC) filters placed in critically ill patients in the ICU at bedside using digital radiograph (DR) guidance with previous cross-sectional imaging for planning, compared to IVC filters placed by conventional fluoroscopy (CF). METHOD AND MATERIALS: The cohort consisted of 129 IVC filter placements; 48 placed at bedside and 81 placed conventionally from July 2015 to September 2016. Patient demographics, indication, radiation exposures, access site, procedural duration, dwell time, and complications were identified by the EMR. IVC Filter positioning with measurements of tip to renal vein distance and lateral filter tilt were performed when cavograms or post placement CTs were available for review. Statistical analysis was performed using Stata IC 11.2. RESULTS: Technical success of the procedure was 100% in both groups. Procedural duration was longer at the bedside lasting 14.5 +/- 10.2 versus 6.7 +/- 6.0 â€‹min (p<0.0001). The bedside DR group had a median radiation exposure of 25 â€‹mGy (15-35) and the CF group had mean radiation exposure of 256.94 â€‹mGy +/- 158.6. There was no significant difference in distance of IVC tip to renal vein (p=0.31), mispositioning (p=0.59), degree of filter tilt (p=0.33), or rate of complications (p=0.65) between the two groups. CONCLUSION: IVCF placement at the bedside using DR is comparable to CF with no statistical difference in outcomes based on IVCF positioning, degree of lateral tilt or removal issues. It decreased radiation dose, but with overall increased procedural time.

Prime editing in mice reveals the essentiality of a single base in driving tissue-specific gene expression.

BACKGROUND: Most single nucleotide variants (SNVs) occur in noncoding sequence where millions of transcription factor binding sites (TFBS) reside. Here, a comparative analysis of CRISPR-mediated homology-directed repair (HDR) versus the recently reported prime editing 2 (PE2) system was carried out in mice over a TFBS called a CArG box in the Tspan2 promoter. RESULTS: Quantitative RT-PCR showed loss of Tspan2 mRNA in aorta and bladder, but not heart or brain, of mice homozygous for an HDR-mediated three base pair substitution in the Tspan2 CArG box. Using the same protospacer, mice homozygous for a PE2-mediated single-base substitution in the Tspan2 CArG box displayed similar cell-specific loss of Tspan2 mRNA; expression of an overlapping long noncoding RNA was also nearly abolished in aorta and bladder. Immuno-RNA fluorescence in situ hybridization validated loss of Tspan2 in vascular smooth muscle cells of HDR and PE2 CArG box mutant mice. Targeted sequencing demonstrated variable frequencies of on-target editing in all PE2 and HDR founders. However, whereas no on-target indels were detected in any of the PE2 founders, all HDR founders showed varying levels of on-target indels. Off-target analysis by targeted sequencing revealed mutations in many HDR founders, but none in PE2 founders. CONCLUSIONS: PE2 directs high-fidelity editing of a single base in a TFBS leading to cell-specific loss in expression of an mRNA/long noncoding RNA gene pair. The PE2 platform expands the genome editing toolbox for modeling and correcting relevant noncoding SNVs in the mouse.

In vivo adenine base editing of PCSK9 in macaques reduces LDL cholesterol levels.

Most known pathogenic point mutations in humans are C•G to T•A substitutions, which can be directly repaired by adenine base editors (ABEs). In this study, we investigated the efficacy and safety of ABEs in the livers of mice and cynomolgus macaques for the reduction of blood low-density lipoprotein (LDL) levels. Lipid nanoparticle-based delivery of mRNA encoding an ABE and a single-guide RNA targeting PCSK9, a negative regulator of LDL, induced up to 67% editing (on average, 61%) in mice and up to 34% editing (on average, 26%) in macaques. Plasma PCSK9 and LDL levels were stably reduced by 95% and 58% in mice and by 32% and 14% in macaques, respectively. ABE mRNA was cleared rapidly, and no off-target mutations in genomic DNA were found. Re-dosing in macaques did not increase editing, possibly owing to the detected humoral immune response to ABE upon treatment. These findings support further investigation of ABEs to treat patients with monogenic liver diseases.

Endoscopist-directed administration of propofol: a worldwide safety experience.

BACKGROUND & AIMS: Endoscopist-directed propofol sedation (EDP) remains controversial. We sought to update the safety experience of EDP and estimate the cost of using anesthesia specialists for endoscopic sedation. METHODS: We reviewed all published work using EDP. We contacted all endoscopists performing EDP for endoscopy that we were aware of to obtain their safety experience. These complications were available in all patients: endotracheal intubations, permanent neurologic injuries, and death. RESULTS: A total of 646,080 (223,656 published and 422,424 unpublished) EDP cases were identified. Endotracheal intubations, permanent neurologic injuries, and deaths were 11, 0, and 4, respectively. Deaths occurred in 2 patients with pancreatic cancer, a severely handicapped patient with mental retardation, and a patient with severe cardiomyopathy. The overall number of cases requiring mask ventilation was 489 (0.1%) of 569,220 cases with data available. For sites specifying mask ventilation risk by procedure type, 185 (0.1%) of 185,245 patients and 20 (0.01%) of 142,863 patients required mask ventilation during their esophagogastroduodenoscopy or colonoscopy, respectively (P < .001). The estimated cost per life-year saved to substitute anesthesia specialists in these cases, assuming they would have prevented all deaths, was $5.3 million. CONCLUSIONS: EDP thus far has a lower mortality rate than that in published data on endoscopist-delivered benzodiazepines and opioids and a comparable rate to that in published data on general anesthesia by anesthesiologists. In the cases described here, use of anesthesia specialists to deliver propofol would have had high costs relative to any potential benefit.

Characterization of craniomaxillofacial battle injuries sustained by United States service members in the current conflicts of Iraq and Afghanistan.

PURPOSE: To characterize and describe the craniomaxillofacial (CMF) battlefield injuries sustained by US Service Members in Operation Iraqi Freedom and Operation Enduring Freedom. PATIENTS AND METHODS: The Joint Theater Trauma Registry was queried from October 19, 2001, to December 11, 2007, for CMF battlefield injuries. The CMF injuries were identified using the "International Classification of Diseases, Ninth Revision, Clinical Modification" codes and the data compiled for battlefield injury service members. Nonbattlefield injuries, killed in action, and return to duty cases were excluded. RESULTS: CMF battlefield injuries were found in 2,014 of the 7,770 battlefield-injured US service members. In the 2,014 injured service members were 4,783 CMF injuries (2.4 injuries per soldier). The incidence of CMF battlefield injuries by branch of service was Army, 72%; Marines, 24%; Navy, 2%; and Air Force, 1%. The incidence of penetrating soft-tissue injuries and fractures was 58% and 27%, respectively. Of the fractures, 76% were open. The location of the facial fractures was the mandible in 36%, maxilla/zygoma in 19%, nasal in 14%, and orbit in 11%. The remaining 20% were not otherwise specified. The primary mechanism of injury involved explosive devices (84%). CONCLUSIONS: Of the injured US service members, 26% had injuries to the CMF region in the Operation Iraqi Freedom/Operation Enduring Freedom conflicts during a 6-year period. Multiple penetrating soft-tissue injuries and fractures caused by explosive devices were frequently seen. Increased survivability because of body armor, advanced battlefield medicine, and the increased use of explosive devices is probably related to the elevated incidence of CMF battlefield injuries. The current use of "International Classification of Diseases, Ninth Revision, Clinical Modification" codes with the Joint Theater Trauma Registry failed to characterize the severity of facial wounds.