Nuclear-penetrating scleroderma autoantibody inhibits topoisomerase 1 cleavage complex formation.

The contributions of anti-Topoisomerase 1 (Top1) autoantibodies to the pathophysiology of diffuse cutaneous systemic sclerosis (dcSSc), the most aggressive scleroderma subtype, are unknown. Top1 catalyzes DNA relaxation and unwinding in cell nuclei, a site previously considered inaccessible to antibodies. The discovery of autoantibodies in systemic lupus erythematosus that penetrate nuclei and inhibit DNA repair raised the possibility that nuclear-penetrating autoantibodies contribute to mechanisms of autoimmunity. Here we show that an anti-Top1 autoantibody produced by a single B cell clone from a patient with dcSSc penetrates live cells and localizes into nuclei. Functionally, the autoantibody inhibits formation of the Top1 cleavage complex necessary for DNA nicking, which distinguishes it from cytotoxic camptothecin Top1 inhibitors used in cancer therapy that trap the cleavage complex rather than preventing its formation. Discovery of a patient-derived cell-penetrating scleroderma anti-Top1 autoantibody that inhibits Top1 cleavage complex formation supports the hypothesis that anti-Top1 autoantibodies contribute to cellular dysfunction in dcSSc and offers a valuable antibody reagent resource for future studies on anti-Top1 autoantibody contributions to scleroderma pathophysiology.

Selective B cell depletion upon intravenous infusion of replication-incompetent anti-CD19 CAR lentivirus.

Anti-CD19 chimeric antigen receptor (CAR)-T therapy for B cell malignancies has shown clinical success, but a major limitation is the logistical complexity and high cost of manufacturing autologous cell products. If engineered for improved safety, direct infusion of viral gene transfer vectors to initiate in vivo CAR-T transduction, expansion, and anti-tumor activity could provide an alternative, universal approach. To explore this approach we administered approximately 20 million replication-incompetent vesicular stomatitis virus G protein (VSV-G) lentiviral particles carrying an anti-CD19CAR-2A-GFP transgene comprising either an FMC63 (human) or 1D3 (murine) anti-CD19 binding domain, or a GFP-only control transgene, to wild-type C57BL/6 mice by tail vein infusion. The dynamics of immune cell subsets isolated from peripheral blood were monitored at weekly intervals. We saw emergence of a persistent CAR-transduced CD3+ T cell population beginning week 3-4 that reaching a maximum of 13.5% ± 0.58% (mean ± SD) and 7.8% ± 0.76% of the peripheral blood CD3+ T cell population in mice infused with ID3-CAR or FMC63-CAR lentivector, respectively, followed by a rapid decline in each case of the B cell content of peripheral blood. Complete B cell aplasia was apparent by week 5 and was sustained until the end of the protocol (week 8). No significant CAR-positive populations were observed within other immune cell subsets or other tissues. These results indicate that direct intravenous infusion of conventional VSV-G-pseudotyped lentiviral particles carrying a CD19 CAR transgene can transduce T cells that then fully ablate endogenous B cells in wild-type mice.

Soft fundamental measure theory functional for the Weeks-Chandler-Andersen repulsive potential.

We introduce a soft fundamental measure theory functional for the purely repulsive Weeks-Chandler-Andersen (WCA) fluid. This classical density functional could serve as a reference fluid for functionals created using thermodynamic perturbation theory instead of the hard-sphere fluid. Our functional incorporates temperature-dependent parameters describing the length scale and effective softness of the particle interaction, and which reproduce the second virial coefficient of the WCA fluid. We find that this approach is comparable in accuracy to the Barker-Henderson approach combined with the White Bear density functional for the hard-sphere fluid.

Defective Early B Cell Tolerance Checkpoints in Patients With Systemic Sclerosis Allow the Production of Self Antigen-Specific Clones.

OBJECTIVE: Early selection steps preventing autoreactive naive B cell production are often impaired in patients with autoimmune diseases, but central and peripheral B cell tolerance checkpoints have not been assessed in patients with systemic sclerosis (SSc). This study was undertaken to characterize early B cell tolerance checkpoints in patients with SSc. METHODS: Using an in vitro polymerase chain reaction-based approach that allows the expression of recombinant antibodies cloned from single B cells, we tested the reactivity of antibodies expressed by 212 CD19+CD21low CD10+IgMhigh CD27- new emigrant/transitional B cells and 190 CD19+CD21+CD10-IgM+CD27- mature naive B cells from 10 patients with SSc. RESULTS: Compared to serum from healthy donors, serum from patients with SSc displayed elevated proportions of polyreactive and antinuclear-reactive new emigrant/transitional B cells that recognize topoisomerase I, suggesting that defective central B cell tolerance contributes to the production of serum autoantibodies characteristic of the disease. Frequencies of autoreactive mature naive B cells were also significantly increased in SSc patients compared to healthy donors, thus indicating that a peripheral B cell tolerance checkpoint may be impaired in SSc. CONCLUSION: Defective counterselection of developing autoreactive naive B cells in SSc leads to the production of self antigen-specific B cells that may secrete autoantibodies and allow the formation of immune complexes, which promote fibrosis in SSc.

Fulminant cardiogenic shock due to cardiac sarcoidosis.

This case describes a 57-year-old man with unrecognized cardiac sarcoidosis who presented with progressive heart failure leading to cardiogenic shock. He required extracorporeal membrane oxygenation (ECMO) as a bridge to orthotopic heart transplantation. The case highlights the potential acute and severe electrical and hemodynamic manifestations of cardiac sarcoidosis.

A Combined Immunofluorescence and Fluorescent Viability Cocktail Staining Procedure for Rapid Microscopic Detection and Enumeration of Live Legionella pneumophila.

This report describes a combined immunofluorescence and fluorescence viability stain applied as one staining solution for rapid detection of live Legionella pneumophila in mixed bacterial populations. Instead of sequential viability staining with the Invitrogen BacLight LIVE/DEAD staining kit followed by antibody-Alexa Fluor (AF) 647 conjugate staining to identify live L. pneumophila, a combined single cocktail solution staining protocol was developed to simplify and accelerate the time to detection of viable L. pneumophila serogroup-1 (SG-1) in mixed species populations on a filter membrane. The stain cocktail will aid in accelerating fluorescence microscopic analysis of cooling tower, air conditioner and water fountain or other liquid samples for the presence of L. pneumophila and its viability status. Visibly red stained cells were identified as dead non-L. pneumophila SG-1 cells, while green fluorescing cells represented viable non-L. pneumophila SG-1 cells. Due to also staining red with antibody-AF 647, L. pneumophila SG-1 cells were pseudocolorized as blue to distinguish them from other dead cells. Fluorescence color emission mixing from the viability dyes (SYTO 9 and propidium iodide) with antibody-AF 647 stained L. pneumophila led to other fluorescent colors. For example, green plus pseudocolorized blue AF 647-antibody- labeled cells were identified as live cyan-colored L. pneumophila SG-1 cells. Magenta-colored cells resulted from dead L. pneumophila cells that combined red propidium iodide with blue pseudocolorized AF 647-antibody emissions. Analysis of measured RGB (red, green, blue) color values in microscopic images of mixed bacterial populations suggests the possibility of facile automated discrimination of subpopulations of live and dead L. pneumophila and non-L. pneumophila species by computers in 3-dimensional RGB color space after staining in the combined cocktail which will save time for more rapid microscopic detection of potential sources of Legionnaire's disease.

ENT2 facilitates brain endothelial cell penetration and blood-brain barrier transport by a tumor-targeting anti-DNA autoantibody.

The blood-brain barrier (BBB) prevents antibodies from penetrating the CNS and limits conventional antibody-based approaches to brain tumors. We now show that ENT2, a transporter that regulates nucleoside flux at the BBB, may offer an unexpected path to circumventing this barrier to allow targeting of brain tumors with an anti-DNA autoantibody. Deoxymab-1 (DX1) is a DNA-damaging autoantibody that localizes to tumors and is synthetically lethal to cancer cells with defects in the DNA damage response. We found that DX1 penetrated brain endothelial cells and crossed the BBB, and mechanistic studies identify ENT2 as the key transporter. In efficacy studies, DX1 crosses the BBB to suppress orthotopic glioblastoma and breast cancer brain metastases. ENT2-linked transport of autoantibodies across the BBB has potential to be exploited in brain tumor immunotherapy, and its discovery raises hypotheses on actionable mechanisms of CNS penetration by neurotoxic autoantibodies in CNS lupus.

Framework to Classify Reverse Cardiac Remodeling With Mechanical Circulatory Support: The Utah-Inova Stages.

BACKGROUND: Variable definitions and an incomplete understanding of the gradient of reverse cardiac remodeling following continuous flow left ventricular assist device (LVAD) implantation has limited the field of myocardial plasticity. We evaluated the continuum of LV remodeling by serial echocardiographic imaging to define 3 stages of reverse cardiac remodeling following LVAD. METHODS: The study enrolled consecutive LVAD patients across 4 study sites. A blinded echocardiographer evaluated the degree of structural (LV internal dimension at end-diastole [LVIDd]) and functional (LV ejection fraction [LVEF]) change after LVAD. Patients experiencing an improvement in LVEF ≥40% and LVIDd ≤6.0 cm were termed responders, absolute change in LVEF of ≥5% and LVEF <40% were termed partial responders, and the remaining patients with no significant improvement in LVEF were termed nonresponders. RESULTS: Among 358 LVAD patients, 34 (10%) were responders, 112 (31%) partial responders, and the remaining 212 (59%) were nonresponders. The use of guideline-directed medical therapy for heart failure was higher in partial responders and responders. Structural changes (LVIDd) followed a different pattern with significant improvements even in patients who had minimal LVEF improvement. With mechanical unloading, the median reduction in LVIDd was -0.6 cm (interquartile range [IQR], -1.1 to -0.1 cm; nonresponders), -1.1 cm (IQR, -1.8 to -0.4 cm; partial responders), and -1.9 cm (IQR, -2.9 to -1.1 cm; responders). Similarly, the median change in LVEF was -2% (IQR, -6% to 1%), 9% (IQR, 6%-14%), and 27% (IQR, 23%-33%), respectively. CONCLUSIONS: Reverse cardiac remodeling associated with durable LVAD support is not an all-or-none phenomenon and manifests in a continuous spectrum. Defining 3 stages across this continuum can inform clinical management, facilitate the field of myocardial plasticity, and improve the design of future investigations.

Intake, nutrient digestibility, rumen parameters, growth rate, carcase characteristics and cannabinoid residues of sheep fed pelleted rations containing hemp (Cannabis sativa L.) stubble.

The feeding value and impact of hemp stubble in the diet of ruminants is unknown. Fifteen Merino castrated male sheep were maintained in individual pens and fed one of three pelletized experimental inclusion diets, as a 0% (Control), 28% (Hemp 1), and 56% (Hemp 2) pellet that delivered a diet meeting the nutrient requirements of the animals. Inclusion of hemp stubble had no effect (P > 0.05) on either DM intake, live weight gain or the feed to gain ratio but positively impacted (P < 0.05) on nutrient digestibility. Hemp stubble inclusion increased the concentration (but not molar proportions) of acetic and butyric acids and increased both the concentrations and molar proportions of iso-butyric, iso-valeric, hexanoic and heptanoic acids, possibly due to increased protein digestibility and/or changes in the composition of rumen cellulolytic bacteria. Tetrahydrocannabinolic acid (THCA) was the only cannabinoid found in plasma in the sheep fed the hemp-containing diets, and this was found at very low concentrations (<16 µg/L). The psychoactive cannabinoid delta-9-tetrahydrocannabinol (Δ 9-THC) was not detected in any plasma samples. THCA was detected in the liver of two sheep fed the Hemp 1 pellets and two sheep fed the Hemp 2 pellets. Cannabidiol (CBD) was detected in the liver of one sheep fed the Hemp 2 pellets (but no liver THCA was detected in this sheep). Δ 9-THC was detected in both the kidney fat and subcutaneous fat of all sheep fed hemp stubble, with the concentrations being higher (P < 0.05) in the sheep fed the Hemp 1 pellets. THCA was also detected in the subcutaneous fat of one of the sheep fed the Hemp 1 pellets. Four of the five sheep fed the Hemp 1 pellet and one of the five sheep fed Hemp 2 pellet had detectable levels of Δ 9-THC in the meat (loin). No other cannabinoids were detected in the meat. Current food standards regulations in Australia prohibit presence of any cannabinoid residues in commercial meat products; thus, determination of a withholding period is required to enable the safe feeding of hemp-stubble to sheep. Further research is also required to gain a greater understanding of the rumen metabolism of cannabinoids.

Investigations into the source attribution of party sparklers using trace elemental analysis and chemometrics.

In Australia, party sparklers are commonly used to initiate or prepare inorganic based homemade explosives (HMEs) as they are the most easily accessible and inexpensive pyrotechnic available on the market. As sparkler residue would be encountered in cases involving these types of devices, the characterisation and source determination of the residue would be beneficial within a forensic investigation. The aim of this study is to demonstrate the potential of using trace elemental profiling coupled with chemometric and other statistical techniques to link a variety of different sparklers to their origin. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the concentration of 50 elements in 48 pre-blast sparkler samples from eight sparkler brands/classes available in Australia. Extracting ground-up sparkler residue in 10% nitric acid for 24 hours was found to give the most reliable quantification. The collected data were analysed using Principal Component Analysis (PCA) to visualise the distribution of the sample data and explore whether the sparkler samples could be classified into their respective brands. ANOVA based feature selection was used to remove elements that did not largely contribute to the separation between classes. This resulted in the development of a 7-elemental profile, consisting of V, Co, Ni, Sr, Sn, Sb, W, which could be used to correctly classify the samples into eight distinct groups. Linear Discriminant Analysis (LDA) was subsequently used to construct a discriminant model using four out of six samples from each class. The model successfully classified 100% of the samples to their correct sparkler brand. The model also correctly matched 100% of the remaining samples to the correct class. This demonstrates the potential of using trace elemental analysis and chemometrics to correctly identify and discriminate between party sparklers.

Delayed Closure of Open Abdomen in Septic Patients Treated With Negative Pressure Vacuum Therapy and Dynamic Sutures: A 10-Years Follow-Up on Long-Term Complications.

Introduction: Patients with open abdomen after surgical interventions associated with the complication of secondary peritonitis are successfully treated with negative pressure wound therapy. The use of dynamic fascial sutures reduces fascial lateralization and increases successful delayed fascial closure after open abdomen treatment. Methods: In 2017 we published the follow-up results of 38 survivors out of 87 open abdomen patients treated with negative pressure wound therapy and dynamic fascial sutures between 2007 and 2012. In our current study we present the 10-years follow-up results regarding long-term complications with the focus on incisional hernias and pain. Since 2017 seven more patients have died, hence 31 patients were included in the current study. The patients were asked to answer questions about specific long-term complications of OA treatment including pain, the presence of incisional hernias and subsequent surgical interventions. Demographic data and data regarding fascial closure after open abdomen treatment were collected. All results were analyzed quantitatively. The follow-up period was 8-13 years. Results: The median age was 69 (30-90) years, and 15 (48.4%) were females. Twenty-four patients (77.4%) responded to the questionnaire: Three patients (12.5%) suffered from pain in the original operating field, all three at rest but not during exercise. None of the patients required analgesic treatment. Eleven patients (45.8%) were found to have incisional hernias. Five out of 11 hernias (45.5%) were treated by surgery and did not declare any pain in the operating field. Among the patients with incisional hernias lower MPI (Mannheimer Peritonitis Index) at the time of primary surgery but more reoperations and treatment days were found. The technique of fascial closure was heterogenic and no differences in the occurrence of incisional hernia could be detected. Conclusion: The incidence of incisional hernias after open abdomen treatment is still high, but are associated with little pain in the original operating field. Further studies are required to investigate methods for fascial closure techniques after OA treatment.

Differential incorporation of SUN-domain proteins into LINC complexes is coupled to gene expression.

LInkers of Nucleoskeleton and Cytoskeleton (LINC) complexes, composed of SUN and KASH-domain proteins, span the nuclear envelope and physically connect the nuclear interior to cytoskeletal elements. Most human cells contain two SUN proteins, Sun1 and Sun2, and several KASH-proteins suggesting that multiple functionally distinct LINC complexes co-exist in the nuclear envelope. We show here, however, that while Sun1 and Sun2 in HeLa cells are each able to bind KASH-domains, Sun1 is more efficiently incorporated into LINC complexes under normal growth conditions. Furthermore, the balance of Sun1 and Sun2 incorporated into LINC complexes is cell type-specific and is correlated with SRF/Mkl1-dependent gene expression. In addition, we found that Sun1 has a LINC complex-independent role in transcriptional control, possibly by regulating the SRF/Mkl1 pathway. Together, these data reveal novel insights into the mechanisms of LINC complex regulation and demonstrate that Sun1 modulates gene expression independently of its incorporation into LINC complexes.

Unrecognized Left Heart Failure in LVAD Recipients: The Role of Routine Invasive Hemodynamic Testing.

The role of routine right heart catheterizations (RHCs) in left ventricular assist device (LVAD) patients is undefined. We analyzed 105 continuous-flow LVAD recipients who underwent an RHC approximately 3 months after implant. In 38 patients, LVAD speed was ramped with the goal of optimizing hemodynamics. Our cohort consisted of 71 (68%) HeartMate II (HMII) and 34 (32%) HeartWare (HVAD) patients. Thirty patients (29%) had either a reduced cardiac index (CI ≤ 2.2 L/min/m), elevated pulmonary capillary wedge pressure (PCWP > 18 mm Hg), or both. A subgroup of 38 patients (19 with abnormal hemodynamics) underwent LVAD ramping. With LVAD ramping, normalization of hemodynamics was achieved in 13 (68%) patients with abnormal hemodynamics. In ramped patients, the CI increased from 2.1 L/min/m (2.0-2.3) to 2.5 L/min/m (2.3-2.6; p = 0.004), and the PCWP dropped from 21 mm Hg (20-26) to 18 mm Hg (14-21, p < 0.001). The 6-minute walk distance improved from 338 m (253-394) to 353 m (320-442, p = 0.041). A 400 rpm change in HMII speed was like a 130 rpm change in HVAD speed and led to a change in cardiac output (CO) of 0.3 L/min. The correlation between device-reported flow and measured CO for both the HMII (Rs = 0.50, p < 0.001) and HVAD (Rs = 0.47, p < 0.001) was moderate. At 3 months after LVAD implant, most patients have normal hemodynamics. Of those patients with abnormal hemodynamics, LVAD ramping results in normalization of hemodynamics and improvement in 6-minute walk distance.

Opposing Effects of Valproic Acid Treatment Mediated by Histone Deacetylase Inhibitor Activity in Four Transgenic X. laevis Models of Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is an inherited retinal degeneration (RD) that leads to blindness for which no treatment is available. RP is frequently caused by mutations in Rhodopsin; in some animal models, RD is exacerbated by light. Valproic acid (VPA) is a proposed treatment for RP and other neurodegenerative disorders, with a phase II trial for RP under way. However, the therapeutic mechanism is unclear, with minimal research supporting its use in RP. We investigated the effects of VPA on Xenopus laevis models of RP expressing human P23H, T17M, T4K, and Q344ter rhodopsins, which are associated with RP in humans. VPA ameliorated RD associated with P23H rhodopsin and promoted clearing of mutant rhodopsin from photoreceptors. The effect was equal to that of dark rearing, with no additive effect observed. Rescue of visual function was confirmed by electroretinography. In contrast, VPA exacerbated RD caused by T17M rhodopsin in light, but had no effect in darkness. Effects in T4K and Q344ter rhodopsin models were also negative. These effects of VPA were paralleled by treatment with three additional histone deacetylase (HDAC) inhibitors, but not other antipsychotics, chemical chaperones, or VPA structural analogues. In WT retinas, VPA treatment increased histone H3 acetylation. In addition, electron microscopy showed increased autophagosomes in rod inner segments with HDAC inhibitor (HDACi) treatment, potentially linking the therapeutic effects in P23H rhodopsin animals and negative effects in other models with autophagy. Our results suggest that the success or failure of VPA treatment is dependent on genotype and that HDACi treatment is contraindicated for some RP cases.SIGNIFICANCE STATEMENT Retinitis pigmentosa (RP) is an inherited, degenerative retinal disease that leads to blindness for which no therapy is available. We determined that valproic acid (VPA), currently undergoing a phase II trial for RP, has both beneficial and detrimental effects in animal models of RP depending on the underlying disease mechanism and that both effects are due to histone deacetylase (HDAC) inhibition possibly linked to autophagy regulation. Off-label use of VPA and other HDAC inhibitors for the treatment of RP should be limited to the research setting until this effect is understood and can be predicted. Our study suggests that, unless genotype is accounted for, clinical trials for RP treatments may give negative results due to multiple disease mechanisms with differential responses to therapeutic interventions.

A Lentiviral Fluorescent Genetic Barcoding System for Flow Cytometry-Based Multiplex Tracking.

Retroviral integration site analysis and barcoding have been instrumental for multiplex clonal fate mapping, although their use imposes an inherent delay between sample acquisition and data analysis. Monitoring of multiple cell populations in real time would be advantageous, but multiplex assays compatible with flow cytometric tracking of competitive growth behavior are currently limited. We here describe the development and initial validation of three generations of lentiviral fluorescent genetic barcoding (FGB) systems that allow the creation of 26, 14, or 6 unique labels. Color-coded populations could be tracked in multiplex in vitro assays for up to 28 days by flow cytometry using all three vector systems. Those involving lower levels of multiplexing eased color-code generation and the reliability of vector expression and enabled functional in vitro and in vivo studies. In proof-of-principle experiments, FGB vectors facilitated in vitro multiplex screening of microRNA (miRNA)-induced growth advantages, as well as the in vivo recovery of color-coded progeny of murine and human hematopoietic stem cells. This novel series of FGB vectors provides new tools for assessing comparative growth properties in in vitro and in vivo multiplexing experiments, while simultaneously allowing for a reduction in sample numbers by up to 26-fold.

Designing coastal conservation to deliver ecosystem and human well-being benefits.

Conservation scientists increasingly recognize that incorporating human values into conservation planning increases the chances for success by garnering broader project acceptance. However, methods for defining quantitative targets for the spatial representation of human well-being priorities are less developed. In this study we employ an approach for identifying regionally important human values and establishing specific spatial targets for their representation based on stakeholder outreach. Our primary objective was to develop a spatially-explicit conservation plan that identifies the most efficient locations for conservation actions to meet ecological goals while sustaining or enhancing human well-being values within the coastal and nearshore areas of the western Lake Erie basin (WLEB). We conducted an optimization analysis using 26 features representing ecological and human well-being priorities (13 of each), and included seven cost layers. The influence that including human well-being had on project results was tested by running five scenarios and setting targets for human well-being at different levels in each scenario. The most important areas for conservation to achieve multiple goals are clustered along the coast, reflecting a concentration of existing or potentially restorable coastal wetlands, coastal landbird stopover habitat and terrestrial biodiversity, as well as important recreational activities. Inland important areas tended to cluster around trails and high quality inland landbird stopover habitat. Most concentrated areas of importance also are centered on lands that are already conserved, reflecting the lower costs and higher benefits of enlarging these conserved areas rather than conserving isolated, dispersed areas. Including human well-being features in the analysis only influenced the solution at the highest target levels.

Opposing roles for distinct LINC complexes in regulation of the small GTPase RhoA.

Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes span the nuclear envelope and transduce force from dynamic cytoskeletal networks to the nuclear lamina. Here we show that LINC complexes also signal from the nuclear envelope to critical regulators of the actin cytoskeleton. Specifically, we find that LINC complexes that contain the inner nuclear membrane protein Sun2 promote focal adhesion assembly by activating the small GTPase RhoA. A key effector in this process is the transcription factor/coactivator complex composed of SRF/Mkl1. A constitutively active form of SRF/Mkl1 was not sufficient to induce focal adhesion assembly in cells lacking Sun2, however, suggesting that LINC complexes support RhoA activity through a transcription-independent mechanism. Strikingly, we also find that the inner nuclear membrane protein Sun1 antagonizes Sun2 LINC complexes and inhibits RhoA activation and focal adhesion assembly. Thus different LINC complexes have opposing roles in the transcription-independent control of the actin cytoskeleton through the small GTPase RhoA.

A knock-in mouse strain facilitates dynamic tracking and enrichment of MEIS1.

Myeloid ecotropic viral integration site 1 (MEIS1), a HOX transcription cofactor, is a critical regulator of normal hematopoiesis, and its overexpression is implicated in a wide range of leukemias. Using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 (Cas9) gene-editing system, we generated a knock-in transgenic mouse line in which a green fluorescent protein (GFP) reporter and a hemagglutinin (HA) epitope tag are inserted near the translational start site of endogenous Meis1. This novel reporter strain readily enables tracking of MEIS1 expression at single-cell-level resolution via the fluorescence reporter GFP, and facilitates MEIS1 detection and purification via the HA epitope tag. This new Meis1 reporter mouse line provides powerful new approaches to track Meis1-expressing hematopoietic cells and to explore Meis1 function and regulation during normal and leukemic hematopoiesis.

A prototype piecewise-linear dynamic attenuator.

The piecewise-linear dynamic attenuator has been proposed as a mechanism in CT scanning for personalizing the x-ray illumination on a patient- and application-specific basis. Previous simulations have shown benefits in image quality, scatter, and dose objectives. We report on the first prototype implementation. This prototype is reduced in scale and speed and is integrated into a tabletop CT system with a smaller field of view (25 cm) and longer scan time (42 s) compared to a clinical system. Stainless steel wedges were machined and affixed to linear actuators, which were in turn held secure by a frame built using rapid prototyping technologies. The actuators were computer-controlled, with characteristic noise of about 100 microns. Simulations suggest that in a clinical setting, the impact of actuator noise could lead to artifacts of only 1 HU. Ring artifacts were minimized by careful design of the wedges. A water beam hardening correction was applied and the scan was collimated to reduce scatter. We scanned a 16 cm water cylinder phantom as well as an anthropomorphic pediatric phantom. The artifacts present in reconstructed images are comparable to artifacts normally seen with this tabletop system. Compared to a flat-field reference scan, increased detectability at reduced dose is shown and streaking is reduced. Artifacts are modest in our images and further refinement is possible. Issues of mechanical speed and stability in the challenging clinical CT environment will be addressed in a future design.

Open and Laparo-Endoscopic Repair of Incarcerated Abdominal Wall Hernias by the Use of Biological and Biosynthetic Meshes.

INTRODUCTION: Although recently published guidelines recommend against the use of synthetic non-absorbable materials in cases of potentially contaminated or contaminated surgical fields due to the increased risk of infection (1, 2), the use of bio-prosthetic meshes for abdominal wall or ventral hernia repair is still controversially discussed in such cases. Bio-prosthetic meshes have been recommended due to less susceptibility for infection and the decreased risk of subsequent mesh explantation. The purpose of this review is to elucidate if there are any indications for the use of biological and biosynthetic meshes in incarcerated abdominal wall hernias based on the recently published literature. METHODS: A literature search of the Medline database using the PubMed search engine, using the keywords returned 486 articles up to June 2015. The full text of 486 articles was assessed and 13 relevant papers were identified including 5 retrospective case cohort studies, 2 case-controlled studies, and 6 case series. RESULTS: The results of Franklin et al. (3-5) included the highest number of biological mesh repairs (Surgisis(®)) by laparoscopic IPOM in infected fields, which demonstrated a very low incidence of infection and recurrence (0.7 and 5.2%). Han et al. (6) reported in his retrospective study, the highest number of treated patients due to incarcerated hernias by open approach using acellular dermal matrix (ADM(®)) with very low rate of infection as well as recurrences (1.6 and 15.9%). Both studies achieved acceptable outcome in a follow-up of at least 3.5 years compared to the use of synthetic mesh in this high-risk population (7). CONCLUSION: Currently, there is a very limited evidence for the use of biological and biosynthetic meshes in strangulated hernias in either open or laparo-endoscopic repair. Finally, there is an urgent need to start with randomized controlled comparative trials as well as to support registries with data to achieve more knowledge for tailored indication for the use of biological meshes.