Impact of Liver Transplantation on Adipose Tissue Compartments and Its Association With Metabolic Sequela.

BACKGROUND: Loss of skeletal muscle can be accompanied by an increase in adipose tissue leading to sarcopenic obesity. There are limited data on how liver transplantation (LT) might impact adipose tissue compartments, particularly among patients with metabolically active disease, such as nonalcoholic steatohepatitis (NASH) and subsequent metabolic sequela. METHODS: Skeletal muscle, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) were measured using cross-sectional imaging performed in 190 patients pre-LT, 6 mo post-LT and 12 mo post-LT. Changes in adipose tissue and their impact on metabolic diseases were determined in patients transplanted for NASH versus non-NASH. RESULTS: Skeletal muscle, VAT, and SAT were similar in patients with NASH and non-NASH pre-LT despite a higher burden of metabolic diseases in patients with NASH. Following LT, no significant differences between skeletal muscle and SAT were observed in the entire cohort and among patients with NASH (versus non-NASH). LT recipients with the highest muscle mass pre-LT were at the greatest risk for muscle loss post-LT. A time-dependent increase in VAT was noted post-LT, which was more robust among patients with a history of NASH cirrhosis. In adjusted multivariate analysis, NASH versus non-NASH was a strong predictor of post-LT increase in VAT (ß-coefficient 3.00, P = 0.04). Pre-LT VAT was an independent predictor of post-LT serum triglycerides (ß-coefficient 5.49 ± 2.78, P = 0.05) and low-density lipoprotein cholesterol (ß-coefficient 1.80 ± 0.75, P = 0.02). A trend between pre-LT VAT and diabetes was noted but did not reach statistical significance. CONCLUSIONS: VAT but not SAT increases rapidly after LT, especially among patients transplanted for NASH cirrhosis and predicts future metabolic burden.

DNA G-Quadruplex Recognition In Vitro and in Live Cells by a Structure-Specific Nanobody.

G-quadruplexes (G4s) are four-stranded DNA secondary structures that occur in the human genome and play key roles in transcription, replication, and genome stability. G4-specific molecular probes are of vital importance to elucidate the structure and function of G4s. The scFv antibody BG4 has been a widely used G4 probe but has various limitations, including relatively poor in vitro expression and the inability to be expressed intracellularly to interrogate G4s in live cells. To address these considerations, we describe herein the development of SG4, a camelid heavy-chain-only derived nanobody that was selected against the human Myc DNA G4 structure. SG4 exhibits low nanomolar affinity for a wide range of folded G4 structures in vitro. We employed AlphaFold combined with molecular dynamics simulations to construct a molecular model for the G4-nanobody interaction. The structural model accurately explains the role of key amino acids and Kd measurements of SG4 mutants, including arginine-to-alanine point mutations that dramatically diminish G4 binding affinity. Importantly, predicted amino acid-G4 interactions were subsequently confirmed experimentally by biophysical measurements. We demonstrate that the nanobody can be expressed intracellularly and used to image endogenous G4 structures in live cells. We also use the SG4 protein to positionally map G4s in situ and also on fixed chromatin. SG4 is a valuable, new tool for G4 detection and mapping in cells.

Legal reform to enhance global text and data mining research.

Outdated copyright laws around the world hinder research.

Using temperature to modify the reaction conditions and outcomes of polymers formed using transfer-dominated branching radical telomerisation (TBRT).

Transfer-dominated Branching Radical Telomerisation (TBRT) enables the production of branched polymers with step-growth backbones using radical telomerisation chemistry. By conducting identical TBRTs over a broad temperature range, the role of temperature in telomer formation and branching has been evaluated. Elevated temperature limits telomer length, thereby allowing a >10% reduction in the amount of telogen required to produce near identical high molecular weight branched polymers.

Subsidence of monoblock and modular titanium fluted tapered stems in revision hip arthroplasty: A retrospective multicentre comparison study.

Background: Tapered, fluted, titanium (TFT) stems have shown good clinical outcomes in revision total hip arthroplasty (rTHA), however concerns exist regarding early subsidence. This study compares subsidence between a modern monoblock 3-degree and a modular 2-degree TFT stem in rTHA. Methods: A retrospective, international multicentre comparative study was conducted including 64 rTHA in 63 patients. A monoblock TFT stem was used in 37 cases and a modular TFT stem was used in 27 cases. Patient demographics, Paprosky femoral bone loss classification, bicortical contact and stem subsidence were recorded at minimum four week follow up. Results: There was no statistically significant difference in overall subsidence (p = 0.318) or the rate of subsidence >10 mm between stems. Mean subsidence was 2.13 mm in the monoblock group and 3.15 mm in the modular group. Two stems subsided >10 mm: one in each group. There was no difference in bicortical contact between groups (p = 0.98). No re-revisions were performed. Conclusions: We found no difference in subsidence between the two stems. Surgeons may consider the use of monoblock stems in rTHA as they have comparably low rates of subsidence and eliminate the small but potentially catastrophic risk of implant fracture at modular junctions associated with modular stems.

The addition of oral Tranexamic acid to knee arthroplasty patients does not further improve blood loss: a double blinded randomized control trial.

Perioperative intravenous (IV) TA has become routine in knee and hip arthroplasty. Less evidence exists on the administration of oral TA in the post- operative period. Our study aims to identify the efficacy and safety of combined perioperative IV and post-operative oral TA on blood loss and Hemoglobin (Hb) drop compared to perioperative IV TA alone. Patients undergoing primary elective knee arthro- plasty at our institution were invited to participate in the study (n=50). A computer-generated randomisation sequence was created online (www.randomization. org), with an allocation ratio of 1:1 and a block size of 50. Group A received perioperative IV TA alone and post-operative oral TA (n= 26) and Group B received perioperative IV TA plus 48 hours additional oral placebo (n= 24). Day 3 total blood loss and Hb drop was calculated. Continuous, normally distributed data (total blood loss) was compared utilising using one-way analysis of variance with post hoc Tukey test. Continuous skewed data (Hb drop) was compared using the Kruskal-Wallis test. P <0.05 was considered statistically significant. Group A demonstrated a trend in decreased total blood loss that was close to statistical significance ( p = 0.072). No difference in Hb drop was identified between the 2 groups. Increased nausea was also observed in Group A. The administration of oral TA to post-operative knee arthroplasty patients does not improve further blood loss compared to patients receiving perioperative IV TA pre-operatively and at wound closure.

Glomerular filtration rate early after liver transplantation independently predicts atherosclerotic events.

Cardiovascular disease (CVD) is an important cause of mortality among liver transplantation (LT) recipients; however, the data on CVD risk stratification following LT are limited. Thus, the primary aim of this study was to evaluate the association between decline in renal function early after LT and atherosclerotic events. This retrospective study included all patients receiving LT between 2007 and 2019. Early renal function was quantified as estimated glomerular filtration rate (GFR) 6 months after LT. The primary endpoint for the study was a composite atherosclerotic cardiovascular event of three-point major adverse cardiovascular events (MACEs), which includes nonfatal myocardial infarction (MI), nonfatal stroke, or death from CVD. A total of 553 LT recipients met entry criteria. After a median follow-up of 74 months (interquartile range 46-111), 94 (17%) LT recipients died and CVD-associated death occurred in 20 patients. MACE-3 occurred in 66 (12%) patients, with nonfatal MI being the most common event (n = 30). A strong inverse relationship between early GFR and MACE-3 was noted in unadjusted analysis with hazard ratio (HR) 0.96 (95% confidence interval [CI] 0.95-0.98; p = 0.0001) and remained significant even after accounting for age, sex, coronary artery disease, diabetes mellitus, hypertension, calcineurin inhibitor use, and Framingham Risk Score (FRS; HR 0.96, 95% CI 0.95-0.97; p = 0.0001 per unit increase in GFR). Furthermore, an independent interaction between GFR, FRS, and likelihood of developing an MACE-3 was noted. GFR 6 months following LT is a strong predictor of developing atherosclerotic events. This relationship is independent of traditional CVD risk stratification models (e.g. FRS) and thus has the potential to be incorporated into CVD risk assessment after LT but requires further validation.

G-quadruplex DNA structures in human stem cells and differentiation.

The establishment of cell identity during embryonic development involves the activation of specific gene expression programmes and is underpinned by epigenetic factors including DNA methylation and histone post-translational modifications. G-quadruplexes are four-stranded DNA secondary structures (G4s) that have been implicated in transcriptional regulation and cancer. Here, we show that G4s are key genomic structural features linked to cellular differentiation. We find that G4s are highly abundant in human embryonic stem cells and are lost during lineage specification. G4s are prevalent in enhancers and promoters. G4s that are found in common between embryonic and downstream lineages are tightly linked to transcriptional stabilisation of genes involved in essential cellular functions as well as transitions in the histone post-translational modification landscape. Furthermore, the application of small molecules that stabilise G4s causes a delay in stem cell differentiation, keeping cells in a more pluripotent-like state. Collectively, our data highlight G4s as important epigenetic features that are coupled to stem cell pluripotency and differentiation.

Neuronal calmodulin levels are controlled by CAMTA transcription factors.

The ubiquitous Ca2+ sensor calmodulin (CaM) binds and regulates many proteins, including ion channels, CaM kinases, and calcineurin, according to Ca2+-CaM levels. What regulates neuronal CaM levels, is, however, unclear. CaM-binding transcription activators (CAMTAs) are ancient proteins expressed broadly in nervous systems and whose loss confers pleiotropic behavioral defects in flies, mice, and humans. Using Caenorhabditis elegans and Drosophila, we show that CAMTAs control neuronal CaM levels. The behavioral and neuronal Ca2+ signaling defects in mutants lacking camt-1, the sole C. elegans CAMTA, can be rescued by supplementing neuronal CaM. CAMT-1 binds multiple sites in the CaM promoter and deleting these sites phenocopies camt-1. Our data suggest CAMTAs mediate a conserved and general mechanism that controls neuronal CaM levels, thereby regulating Ca2+ signaling, physiology, and behavior.

Interactome analysis of Caenorhabditis elegans synapses by TurboID-based proximity labeling.

Proximity labeling provides a powerful in vivo tool to characterize the proteome of subcellular structures and the interactome of specific proteins. The nematode Caenorhabditis elegans is one of the most intensely studied organisms in biology, offering many advantages for biochemistry. Using the highly active biotin ligase TurboID, we optimize here a proximity labeling protocol for C. elegans. An advantage of TurboID is that biotin's high affinity for streptavidin means biotin-labeled proteins can be affinity-purified under harsh denaturing conditions. By combining extensive sonication with aggressive denaturation using SDS and urea, we achieved near-complete solubilization of worm proteins. We then used this protocol to characterize the proteomes of the worm gut, muscle, skin, and nervous system. Neurons are among the smallest C. elegans cells. To probe the method's sensitivity, we expressed TurboID exclusively in the two AFD neurons and showed that the protocol could identify known and previously unknown proteins expressed selectively in AFD. The active zones of synapses are composed of a protein matrix that is difficult to solubilize and purify. To test if our protocol could solubilize active zone proteins, we knocked TurboID into the endogenous elks-1 gene, which encodes a presynaptic active zone protein. We identified many known ELKS-1-interacting active zone proteins, as well as previously uncharacterized synaptic proteins. Versatile vectors and the inherent advantages of using C. elegans, including fast growth and the ability to rapidly make and functionally test knock-ins, make proximity labeling a valuable addition to the armory of this model organism.

Resurrection of Chronically Occluded Prosthetic Bypass Grafts in a Single Stage with Suction Thrombectomy and Intervention.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) continues to be a vexing problem despite the advent of endovascular techniques augmenting traditional open repair. At our institution, we have found there is a growing number of patients with PAOD who are vein-challenged and have undergone prosthetic bypass previously for infrainguinal arterial reconstruction. When occluded, these grafts have been abandoned for a new bypass strategy or amputation. We present a novel technique of reestablishing flow through chronically occluded prosthetic bypass grafts. METHODS: A retrospective review of a prospectively maintained database compiled at 2 institutions between 2016 and 2019 was performed. Six patients had previous prosthetic bypass grafts with 4 patients having femoral to popliteal grafts, 1 patient with a femoral to femoral graft, and 1 with a femoral to posterior tibial bypass graft. All patients had an attempted single-stage intervention to clear chronically occluded grafts. RESULTS: A total of 6 patients were included in the study. Indications for intervention were chronic, critical limb ischemia with tissue loss (3), severe claudication (2), and acute on chronic limb ischemia (1). Average time from bypass to suction thrombectomy was 29 months (6-60 months). Mean patency duration is 13 months (1-28 months). Adjunctive procedures include overnight lysis to improve outflow in 1 patient (16.6%), drug-coated balloon angioplasty (83.3%), or stents (83.3%). There were no embolic complications during these procedures. All (2) wounds healed and all are maintained on full-dose anticoagulation and/or antiplatelet therapy. CONCLUSIONS: Often, the timing of bypass graft occlusion is unknown, and the risk of embolism with lysis for chronically occluded bypass grafts is concerning with traditional peripheral intervention techniques. We report a new and unique minimally invasive approach to resurrect chronically occluded prosthetic bypass grafts often successful in just one stage. This tool offers an alternative technique for limb salvage in complex patients and as use increases, requires further interrogation.

Quantification of branching within high molecular weight polymers with polyester backbones formed by transfer-dominated branching radical telomerisation (TBRT).

New branched polymerisations offer previously inaccessible macromolecules and architectural understanding is important as it provides insight into the branching mechanism and enables the determination of structure-property relationships. Here we present a detailed inverse gated 13C NMR characterisation of materials derived from the very recently reported Transfer-dominated Branching Radical Telomerisation (TBRT) approach to quantify branching and provide an insight into cyclisation.

Initial Results of Selected Use of Covered Stents in Transcarotid Artery Revascularization.

BACKGROUND: Transcarotid artery revascularization (TCAR) is a novel, hybrid approach to treating carotid disease in the treatment of stroke and stroke prevention. Early results of this hybrid approach to carotid stenting using flow reversal have been promising, with reported stroke rates around 1-2.8%.1,2 Currently, carotid stenting, regardless of approach, is performed with uncovered stents, which incurs the risk of plaque protrusion through the stent and in-stent restenosis. Overall, plaque protrusion is a rare event, with a reported incidence of 2.8% on angiography, but it is associated a high rate of ischemic complications (up to 66.7%).3 The use of covered stents could eliminate the risk of plaque protrusion and therefore short to midterm embolic phenomenon during the remodeling process. It also may improve rates of in-stent restenosis as it is a fully covered stent. Adoption of this technique has the potential to further improve the safety, efficacy, and durability of TCAR. METHODS: We performed a retrospective review of a prospectively maintained database of patients undergoing TCAR with covered stents between September 2018 and December 2019. Procedures were performed by the same operator at 2 separate institutions. Indications included severe asymptomatic or symptomatic carotid stenosis with high-risk lesions defined as lesions 2 cm lesions or longer and/or >50% of the lesion containing soft plaque or bleeding carotid pseudoaneurysm. Our primary outcomes included periprocedural and 30-day stroke rates. Secondary outcomes included stent patency and other procedure-related complications. All patients were maintained on clopidogrel postprocedure for 3 months and then transitioned to aspirin, unless otherwise indicated. RESULTS: A total of 6 patients underwent TCAR with covered stent angioplasty during this time period. Patient demographics included 5 males and 1 female, with an average age of 70.8 ± 4.6 years. Indications for stenting included 4 patients with asymptomatic >70% carotid stenosis and 1 patient with transient ischemic attack-like symptoms and >70% stenosis, and 1 patient with bleeding carotid pseudoaneurysm. Gore Viabahn covered stents were used in all patients. There were no periprocedural or postprocedural ischemic events at 30 days. All 6 stents remained patent at follow-up on duplex ultrasound, and all patients remained asymptomatic on clinical follow-up (average 3.4 [1.4-6.9] months). CONCLUSIONS: The use of covered stents for TCAR appears to be a safe and effective in select patients requiring carotid intervention. It holds the potential to decrease ischemic events from plaque protrusion and in-stent restenosis in the long-term. Further investigation in device design or clinical evaluation is warranted.

MALT-1 mediates IL-17 neural signaling to regulate C. elegans behavior, immunity and longevity.

Besides pro-inflammatory roles, the ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate IL-17 signaling in neurons, and the extent it can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans neurons. We identify the paracaspase MALT-1 as a critical output of the pathway. MALT1 mediates signaling from many immune receptors in mammals, but was not previously implicated in IL-17 signaling or nervous system function. C. elegans MALT-1 forms a complex with homologs of Act1 and IRAK and appears to function both as a scaffold and a protease. MALT-1 is expressed broadly in the C. elegans nervous system, and neuronal IL-17-MALT-1 signaling regulates multiple phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural circuit function downstream of IL-17 to remodel physiology and behavior.

Regorafenib is effective against neuroblastoma in vitro and in vivo and inhibits the RAS/MAPK, PI3K/Akt/mTOR and Fos/Jun pathways.

BACKGROUND: Regorafenib is an inhibitor of multiple kinases with aberrant expression and activity in neuroblastoma tumours that have potential roles in neuroblastoma pathogenesis. METHODS: We evaluated neuroblastoma cells treated with regorafenib for cell viability and confluence, and analysed treated cells for apoptosis and cell cycle progression. We evaluated the efficacy of regorafenib in vivo using an orthotopic xenograft model. We evaluated regorafenib-mediated inhibition of kinase targets and performed reverse-phase protein array (RPPA) analysis of neuroblastoma cells treated with regorafenib. Lastly, we evaluated the efficacy and effects of the combination of regorafenib and 13-cis-retinoic acid on intracellular signalling. RESULTS: Regorafenib treatment resulted in reduced neuroblastoma cell viability and confluence, with both induction of apoptosis and of cell cycle arrest. Regorafenib treatment inhibits known receptor tyrosine kinase targets RET and PDGFRß and intracellular signalling through the RAS/MAPK, PI3K/Akt/mTOR and Fos/Jun pathways. Regorafenib is effective against neuroblastoma tumours in vivo, and the combination of regorafenib and 13-cis-retinoic acid demonstrates enhanced efficacy compared with regorafenib alone. CONCLUSIONS: The effects of regorafenib on multiple intracellular signalling pathways and the potential additional efficacy when combined with 13-cis-retinoic acid represent opportunities to develop treatment regimens incorporating regorafenib for children with neuroblastoma.

Novel Approach to Treatment of Chronic Iliocaval Occlusion Utilizing Covered Stents.

BACKGROUND: Chronic iliocaval obstruction is a challenging clinical entity to treat. Endovenous iliocaval stenting is becoming the treatment of choice for central vein stenosis and occlusion. However, outcomes in thrombotic disease have not been as robust as nonthrombotic disease. In this article, we describe our experience utilizing covered stents as a novel tool for chronic total occlusions of the iliocaval veins. METHODS: We performed a retrospective review of a prospectively maintained database of all patients undergoing endovenous stenting with a covered stent for chronic occlusive iliocaval disease over a 3-year period at our institution. Patients were followed clinically and with venous duplexes to assess the feasibility, safety, and outcomes of iliocaval endovenous stenting with covered stents. RESULTS: A total of 10 patients (8 men and 2 women) underwent iliocaval stenting with covered stents from July 2015 to May 2018. A total of 20 self-expanding covered stents (SECS) and 13 balloon expandable covered stents (BECS) were deployed in the central veins of the 10 patients. Six SECS and 5 BECS were deployed in the inferior vena cava, 10 SECS and 6 BECS were deployed in the common iliac veins (CIVs) (5 patients had bilateral CIV BECS and 2 patients had bilateral CIV SECS), and 4 SECS and 2 BECS were deployed in the external iliac veins (2 patients had bilateral SECS placed). Median follow-up time was 12.1 (range 0.5-35.0) months. There were no perioperative or postoperative complications. Nine (90%) patients maintained primary stent patency during our follow-up time. One patient (10%) had rethrombosis of his stent due to undertreated common femoral vein disease in the setting of a new myeloproliferative neoplasm and an inappropriate cessation of therapeutic anticoagulation. All patients who were symptomatic preoperatively had improvement in their pain, venous ulceration, and venous claudication. Eight of nine (89%) patients had improvement in their lower extremity edema. CONCLUSIONS: Covered endovenous stenting of chronically occluded central veins is a safe and promising procedure. Their use may improve the short- and long-term outcomes in this challenging patient population. Further studies are required to evaluate the long-term efficacy and cost of their use.

The Annual Trip to the Ice-rink: A Seasonal Cause of Wrist Trauma in Irish Hospitals.

Fractures of the distal radius are a common orthopaedic presentation in Irish emergency departments. As a nation, Irish people tend to ice-skate seasonally with a peak of interest seen during the Winter months in temporary ice-rinks. This case series describes winter ice-skating as a significant cause of wrist fractures in the younger patient, including five cases of distal radius fractures, four of which ultimately required internal fixation, under general anaesthesia, over a single weekend in the month of December. Despite all five patients being amateur ice-skaters, all denied ever having taken ice-skating lessons. This demonstrates the dangers of wrist trauma in the inexperienced or beginner ice-skaters on temporary ice-rinks; the seasonal morbidity suffered as a result.

Two-hole versus four-hole plate dynamic hip screw: a systematic review of current evidence.

BACKGROUND: The dynamic hip screw (DHS) is a common device used in the fixation of hip fractures. Traditionally, this involves the use of a four-hole side plate. Reducing the length of the side plate would theoretically reduce the amount of surgical exposure required, decrease surgery duration, and decrease perioperative morbidity and mortality. Our study aims to review the current evidence regarding the use of two-hole side plates, their use and potential complications. METHODS: Using PRISMA guidelines, two independent reviewers performed a search to collate the available literature from medical databases PubMed, EMBASE, Web of Science, and the Cochrane library. Only clinical and biochemical studies were included. The reference lists of articles included for full text review were searched for any additional primary or review publications. RESULTS: Four online libraries were searched, with a combined total of 5344 titles reviewed. Following title, abstract, and full text review, 8 articles were considered suitable for inclusion in qualitative analysis. There was a trend towards equal efficiency between two- and four-hole plates when used in stable fractures in terms of blood loss, failure/revision rates, operative and hospital stay durations, collapse loading testing, maximum stress, and fragment migration. CONCLUSION: The results of this study show that DHS constructs with two- or four-hole side plates have comparable outcomes when used in patients with stable fracture patterns. However, the majority of the clinical data regarding the use of two-hole DHS plates come from retrospective case series; further prospective, randomised control trials would be of significant benefit. LEVEL OF EVIDENCE: Level II; systematic review of all levels of evidence.

Assessing the Time to Ward Transfer in Patients Presenting to the Emergency Department with an Acute Hip Fracture: A Closed-loop Audit.

Introduction The British Orthopaedic Association and British Geriatric Association Blue Book guidelines for patients presenting acutely with a hip fracture stipulate that the patient should be admitted to an acute orthopedic ward within four hours of presentation to the emergency department (ED).  Materials and methods A retrospective review of all patients who presented to the ED with a hip fracture diagnosed on plain film X-Ray over an eight-week period by a single auditor. Time of arrival, time to X-ray, time of blood draw, time to orthopedic referral, time to orthopedic review, and time to arrival at the orthopedic ward were documented. A policy change stipulating that orthopedics on call would prospectively review potential hip fracture patients prior to definitive workup was initiated. The same parameters were re-audited following this intervention over a six-week period. Results Pre-intervention, the mean time to orthopedic review was 83 minutes with a mean time to ward of 417 minutes. Post-intervention, the mean time to orthopedic review was 76 minutes with a mean time to ward of 333 minutes. When orthopedic trainees were on call, the mean time to review was 37.5 minutes with a mean time to ward of 294 minutes. Conclusions While we were able to demonstrate an improvement in orthopedic response times, this did not significantly improve time to ward transfer. This highlights a number of other areas that need to be optimized to improve compliance with best practice guidelines.