Characterization of the skeletal muscle arginine methylome in health and disease reveals remodeling in amyotrophic lateral sclerosis.

Arginine methylation is a protein posttranslational modification important for the development of skeletal muscle mass and function. Despite this, our understanding of the regulation of arginine methylation under settings of health and disease remains largely undefined. Here, we investigated the regulation of arginine methylation in skeletal muscles in response to exercise and hypertrophic growth, and in diseases involving metabolic dysfunction and atrophy. We report a limited regulation of arginine methylation under physiological settings that promote muscle health, such as during growth and acute exercise, nor in disease models of insulin resistance. In contrast, we saw a significant remodeling of asymmetric dimethylation in models of atrophy characterized by the loss of innervation, including in muscle biopsies from patients with myotrophic lateral sclerosis (ALS). Mass spectrometry-based quantification of the proteome and asymmetric arginine dimethylome of skeletal muscle from individuals with ALS revealed the largest compendium of protein changes with the identification of 793 regulated proteins, and novel site-specific changes in asymmetric dimethyl arginine (aDMA) of key sarcomeric and cytoskeletal proteins. Finally, we show that in vivo overexpression of PRMT1 and aDMA resulted in increased fatigue resistance and functional recovery in mice. Our study provides evidence for asymmetric dimethylation as a regulator of muscle pathophysiology and presents a valuable proteomics resource and rationale for numerous methylated and nonmethylated proteins, including PRMT1, to be pursued for therapeutic development in ALS.

Effectiveness of a native vein arteriovenous fistula tracking system.

OBJECTIVE: This study aims to evaluate the effectiveness of a tracking program on the functional maturation rate of arteriovenous fistula (AVF). METHODS: Two major clinical outcomes (commencement of cannulation and functional maturation) of created AVFs were compared between two cohorts. (i) Cohort 1: historical cohort; (ii) Cohort 2: AVFs created after implementation of the tracking project. Multivariable Cox regression models were used to assess the association between cohort allocation and the two major clinical outcomes. RESULTS: Data of 114 and 141 patients were analyzed respectively from Cohorts 1 (historical data) and 2 (with AVF tracking). After adjustment of covariates in the multivariable analysis, the AVFs created in Cohort 2 were more likely to be cannulated earlier (adjusted HR: 2.82; 95% CI: 1.97-4.05; p < 0.001), compared to those in Cohort 1. Similarly, the AVFs of Cohort 2 patients had significantly higher probability of functional maturation (adjusted HR: 1.81; 95% CI: 1.31-2.48; p < 0.001) than fistulas in Cohort 1. Cannulation was commenced for half of the AVFs by 4.1 months post-creation in the historical cohort (Cohort 1), whereas in the post-tracking cohort, 50% of the AVFs were cannulated by 2.3 months after creation (p < 0.001). It took 5.5 and 4.3 months for 50% of the AVFs created in Cohort 1 and Cohort 2 patients to achieve catheter-free functional maturation, respectively (p = 0.06). CONCLUSION: An AVF tracking program with maturation target for the access surgeons, together with a standardized tracking, feedback, and clinical strategy adjustment system is able to improve the AVF functional maturation rate.

Prevalence of SIRS with primary epiploic appendagitis.

PURPOSE: Primary epiploic appendagitis (PEA) is not an uncommon cause of abdominal pain. The systemic inflammatory response syndrome (SIRS) criteria have high sensitivity for early detection of inflammation and infection. To date, there is limited data about the association between SIRS and PEA. The aims of this retrospective study were to evaluate the prevalence of SIRS response and its clinical relevance in patients diagnosed with PEA within a large tertiary hospital network. METHODS: A retrospective study was performed on all consecutive adult patients who presented to four major emergency departments with CT-confirmed PEA from 01 January 2022 to 27 March 2023. The fulfilment of SIRS criteria, hospital admission rate and treatments provided were analysed for these patients. RESULTS: Seventy-three patients had CT-confirmed PEA. Seventeen patients (23.2%) with PEA were SIRS positive. The hospital admission rate in the SIRS group trended higher than the non-SIRS group (odds ratio of 2.51, 95% CI (0.75, 8.39)). The odds of having an associated radiological comorbidity unrelated to PEA were 18.7 times higher in the SIRS positive group. Fifty-seven (78%) patients were discharged home, and 16 (22%) patients were admitted into hospital. Nearly all patients were treated conservatively (98.6%). CONCLUSION: PEA patients with SIRS response trend towards a higher hospital admission rate and are significantly more likely to have other radiological comorbidities than non-SIRS patients. It is important to look for other pathological conditions in a SIRS positive patient with a CT-diagnosis of PEA.

Successful repair of transplant renal artery aneurysm (TRAA).

BACKGROUND: Transplant renal artery aneurysm (TRAA) is rare. TRAA that develops post transplantation consists of 0.10% of the vascular complications post renal transplant (Transplant Proc 41:1609-1614, 2009; Indian J Urol 29:42-47, 2013). CASE PRESENTATION: We report a case of TRAA in an asymptomatic young female. CT angiogram with detailed 3D reconstruction showed a 2.6 × 2.2 cm wide neck saccular TRAA arising from the anterior segmental branch of the graft renal artery (Figs. 2 and 3). A multidisciplinary team of interventional radiologists, vascular and urologist was involved for preoperative surgical planning and unique repair methods. Endovascular and percutaneous approaches were deemed not feasible, and an open in vivo approach with a saphenous vein graft was taken. CONCLUSION: TRAA, albeit rare, is a complication that can occur post renal transplant. In-vivo surgical repair of TRAA is feasible with a multidisciplinary approach and careful preoperative planning. Saphenous vein graft is still a versatile graft and can be used as a conduit successfully.

NPT520-34 improves neuropathology and motor deficits in a transgenic mouse model of Parkinson's disease.

NPT520-34 is a clinical stage, small molecule being developed for the treatment of Parkinson's disease and other neurodegenerative disorders. The therapeutic potential of NPT520-34 was first suggested by findings from cell-based assays of alpha-synuclein clearance. As reported here, NPT520-34 was subsequently evaluated for therapeutically relevant actions in a transgenic animal model of Parkinson's disease that overexpresses human alpha-synuclein and in an acute lipopolysaccharide-challenge model using wild-type mice. Daily administration of NPT520-34 to mThy1-alpha-synuclein (Line 61) transgenic mice for 1 or 3 months resulted in reduced alpha-synuclein pathology, reduced expression of markers of neuroinflammation, and improvements in multiple indices of motor function. In a lipopolysaccharide-challenge model using wild-type mice, a single dose of NPT520-34 reduced lipopolysaccharide-evoked increases in the expression of several pro-inflammatory cytokines in plasma. These findings demonstrate the beneficial effects of NPT520-34 on both inflammation and protein-pathology end points, with consequent improvements in motor function in an animal model of Parkinson's disease. These findings further indicate that NPT520-34 may have two complementary actions: (i) to increase the clearance of neurotoxic protein aggregates; and (ii) to directly attenuate inflammation. NPT520-34 treatment may thereby address two of the predominate underlying pathophysiological aspects of neurodegenerative disorders such as Parkinson's disease.

A percutaneous approach to create tricuspid regurgitation in swine: a model for transcatheter tricuspid valve therapy assessment.

PURPOSE: The purpose of this study was to develop a simple and effective percutaneous approach to create tricuspid regurgitation in swine. METHODS: Eleven pigs (71.68 ± 7.70 kg, 3 male) were involved in this study. A grasping forceps was introduced into the right ventricle through a steerable sheath under fluoroscopic guidance and used to disrupt the tricuspid valve apparatus by avulsing leaflet or chordae tendineae repeatedly. Transthoracic echocardiography and right ventricular angiography were used to evaluate the degree of tricuspid regurgitation created. RESULTS: Ten of the 11 pigs (90.91%) achieved severe tricuspid regurgitation and 1 (9.09%) obtained moderate tricuspid regurgitation immediately after the procedure. Heart rate of the pigs significantly increased immediately after tricuspid regurgitation creation compared to baseline (88.64 ± 23.24 vs. 76.00 ± 15.30 bpm, P = 0.02), but recovered to normal level at one month follow-up (77.09 ± 11.97 bpm, P = 0.85). The right atrium, tricuspid valve annulus, and right ventricle dilated obviously one month after tricuspid regurgitation creation (dimension changes: 3.01 ± 0.35 vs. 3.56 ± 0.40 cm, P = 0.02; 2.92 ± 0.36 vs. 3.37 ± 0.39 cm, P = 0.01; 3.06 ± 0.42 vs. 3.60 ± 0.47 cm, P = 0.03 respectively). Autopsy findings showed that rupture of leaflet and/or chordae tendineae finally led to the tricuspid regurgitation. CONCLUSIONS: Severe tricuspid regurgitation can be created by a simple and effective percutaneous approach with a grasping forceps in swine model and right heart dilation can be observed consistently at one-month follow-up. This model will be valuable in pre-clinical studies for developing new tricuspid valve repair or replacement technique to treat severe tricuspid regurgitation.

Experience from a Singapore tertiary hospital with restructuring of a vascular surgery practice in response to national and institutional policies during the COVID-19 pandemic.

Singapore was one of the first countries to be affected by COVID-19, with the index patient diagnosed on January 23, 2020. For 2 weeks in February, we had the highest number of COVID-19 cases behind China. In this article, we summarize the key national and institutional policies that were implemented in response to COVID-19. We also describe in detail, with relevant data, how our vascular surgery practice has changed because of these policies and COVID-19. We show that with a segregated team model, the vascular surgery unit can still function while reducing risk of cross-contamination. We explain the various strategies adopted to reduce outpatient and inpatient volume. We provide a detailed breakdown of the type of vascular surgical cases that were performed during the COVID-19 pandemic and compare it with preceding months. We discuss our operating room and personal protective equipment protocols in managing a COVID-19 patient and share how we continue surgical training amid the pandemic. We also discuss the challenges we might face in the future as COVID-19 regresses.

Effect of brachial plexus block-driven vascular access planning on primary distal arteriovenous fistula recruitment and outcomes.

OBJECTIVE: Hemodialysis vascular accesses (VAs) are traditionally planned based on the nondominant upper extremity preoperative physical and sonographic vascular findings. Clinical guidelines advocate the use of the most suitably distended vein in the most distal location. Brachial plexus block (BPB), through its sympathectomy-like effect, promotes vasodilation and can thus further optimize vein recruitment and operative strategy. However, studies on its role in driving primary distal autogenous arteriovenous fistula (AVF) placement are limited. We therefore evaluated a traditional approach of clinic-based VA planning against an on-table sonography-guided strategy under BPB. METHODS: This was a prospective observational study involving 110 consecutive end-stage renal disease multiethnic Asian patients referred for primary VA creation under BPB after preoperative venous mapping. Cases were grouped according to whether there was a preset operative plan for radial cephalic (RC) or brachial cephalic (BC) AVF creation based on artery and vein >2 mm and >2.5 mm size criteria respectively (group A) or vein size or length were suboptimal (2-2.5 mm and <5 cm respectively), thus precluding any operative plan till after BPB (group B). Group B also included cases with a preset VA plan but that subsequently underwent an on-table change in operative plan as a result of more favorable distal vein dilation post-BPB. RC AVF recruitment, maturation, and patency rates were compared in the two groups over a 1-year follow up. RESULTS: One hundred RC and BC AVF were available for analysis after excluding brachial AVFs and grafts: 41 in group A and 59 in group B. Twenty one (51%) primary RC AVFs were created according to a preset preoperative plan compared with 37 (63%) based upon on-table planning or plan modification (P > .05). Satisfactory post-BPB forearm vasodilation resulted in 44% of 36 plans for BC being changed to RC AVFs. RC AVF 6-week hemodynamic maturation and 3-month functional maturation in group A vs B were 48% vs 60% and 69% vs 57%, respectively (P > .05). One-year primary and secondary patency rates were 57% vs 50% and 73% vs 87%, respectively (log rank >.05). Outcomes of RC AVFs in group B were not inferior to those of BC AVFs. CONCLUSIONS: On-table BPB-driven VA planning and plan modification strategy contribute to considerable AVF recruitment but do not lead to significantly better distal AVF prevalence or outcomes over the traditional approach. An adequately powered randomized controlled study is, however, warranted to better assess the long-term clinical and cost benefits of such a strategy.

Review article: Efficacy of prophylactic ondansetron versus placebo or control in reducing vomiting in children undergoing ketamine procedural sedation in the emergency department: A systematic review and meta-analysis.

Ketamine is commonly used for procedural sedation anaesthesia in paediatric patients undergoing painful procedures in the ED. Ketamine's safety profile is excellent, but ketamine-associated vomiting (KAV) is common. Routine ondansetron prophylaxis could reduce KAV incidence. This literature review evaluated the efficacy of prophylactic ondansetron in reducing KAV incidence. A systematic literature review was performed on databases and trial registries on 14 January 2023 to identify randomised controlled trials. The primary outcome was reduction in KAV incidence, for any route of prophylactic ondansetron, in ED and up to 24 h post-discharge. ED length of stay, parental satisfaction and time to resumption of normal diet were secondary outcomes. Data analysis was performed using Revman 5.3. Meta-analysis was performed using random effects modelling. Risk of bias was assessed using the Cochrane Risk-of-Bias 2 tool. Evidence quality was assessed using Grading of Recommendation, Assessment Development and Evaluation methodology. Five trials with 920 participants met the eligibility criteria. Prophylactic ondansetron resulted in a reduction in KAV incidence overall odds ratio of 0.51 (95% confidence interval: 0.36-0.73). Intravenous and intramuscular prophylactic ondansetron showed benefit whereas the effect of oral administration was unclear. There was no difference between groups for secondary outcomes overall. The quality of evidence was deemed to be low overall because of high risk of bias and imprecision in outcome measures. This review found low to moderate certainty evidence that prophylactic ondansetron reduces KAV incidence. Methodologically rigorous research, with appropriately timed prophylactic ondansetron based on the route of administration, would further elucidate prophylactic oral ondansetron's efficacy.

Drug target prediction through deep learning functional representation of gene signatures.

Many machine learning applications in bioinformatics currently rely on matching gene identities when analyzing input gene signatures and fail to take advantage of preexisting knowledge about gene functions. To further enable comparative analysis of OMICS datasets, including target deconvolution and mechanism of action studies, we develop an approach that represents gene signatures projected onto their biological functions, instead of their identities, similar to how the word2vec technique works in natural language processing. We develop the Functional Representation of Gene Signatures (FRoGS) approach by training a deep learning model and demonstrate that its application to the Broad Institute's L1000 datasets results in more effective compound-target predictions than models based on gene identities alone. By integrating additional pharmacological activity data sources, FRoGS significantly increases the number of high-quality compound-target predictions relative to existing approaches, many of which are supported by in silico and/or experimental evidence. These results underscore the general utility of FRoGS in machine learning-based bioinformatics applications. Prediction networks pre-equipped with the knowledge of gene functions may help uncover new relationships among gene signatures acquired by large-scale OMICs studies on compounds, cell types, disease models, and patient cohorts.

Foot care behaviours and associated factors among patients with type 2 diabetes: A cross-sectional study.

Background: As numerous studies highlighted the importance of maintaining proper foot care (FC) behaviours among individuals with diabetes to prevent complications, we sought to assess FC behaviours among patients with diabetes and to identify the factors associated with the practice of diabetic FC. Methods: We used a cross-sectional design and collected data through self-reported questionnaires administered to a sample of 586 patients from five medical centres. We conducted descriptive and inferential analyses to explore the relationships between potential risk and protective factors and FC behaviours. Results: Overall, 429 individuals (73.2%) had good FC behaviours, while 157 (26.8%) displayed poor FC behaviours. Furthermore, we identified eight influencing factors on FC behaviours, including smoking status, the availability of a caregiver, the presence of diabetic foot ulcers, amputation history, FC knowledge, subjective norms in diabetes self-care behaviour, diabetes-related stress, and quality of life index values. The logistic regression analysis showed that current smokers were 60% less likely to practice good FC compared to non-smokers (odds ratio (OR) = 0.40; 95%; confidence interval (CI) = 0.22-0.73). Having a caregiver decreased the likelihood of practicing good FC by 50% (OR = 0.52; 95% CI = 0.33-0.84), while having diabetic foot ulcers doubled it (OR = 2.65; 95% CI = 1.26-5.54). Additionally, more FC knowledge increased the likelihood by 20% (OR = 1.21; 95% CI = 1.10-1.33), and higher diabetes-related stress increased it by 1.03 times (OR = 1.03; 95% CI = 1.02-1.05). Conclusions: Our findings underscore the interplay of various factors influencing FC behaviours among individuals with diabetes and call for targeted interventions and tailored strategies to improve FC practices in this vulnerable population.

Diversity in the fertilization envelopes of echinoderms.

Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium-induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here, we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all, of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, and rendezvin. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs decreased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, but different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation for cell surface changes in sea urchins has been shifted to later in oogenesis, and perhaps reflects the meiotic differences among the species-sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxons in which eggs have completed meiosis prior to fertilization.

Inhibition of both HIV-1 reverse transcription and gene expression by a cyclic peptide that binds the Tat-transactivating response element (TAR) RNA.

The RNA response element TAR plays a critical role in HIV replication by providing a binding site for the recruitment of the viral transactivator protein Tat. Using a structure-guided approach, we have developed a series of conformationally-constrained cyclic peptides that act as structural mimics of the Tat RNA binding region and block Tat-TAR interactions at nanomolar concentrations in vitro. Here we show that these compounds block Tat-dependent transcription in cell-free systems and in cell-based reporter assays. The compounds are also cell permeable, have low toxicity, and inhibit replication of diverse HIV-1 strains, including both CXCR4-tropic and CCR5-tropic primary HIV-1 isolates of the divergent subtypes A, B, C, D and CRF01_AE. In human peripheral blood mononuclear cells, the cyclic peptidomimetic L50 exhibited an IC(50) ∼250 nM. Surprisingly, inhibition of LTR-driven HIV-1 transcription could not account for the full antiviral activity. Timed drug-addition experiments revealed that L-50 has a bi-phasic inhibition curve with the first phase occurring after HIV-1 entry into the host cell and during the initiation of HIV-1 reverse transcription. The second phase coincides with inhibition of HIV-1 transcription. Reconstituted reverse transcription assays confirm that HIV-1 (-) strand strong stop DNA synthesis is blocked by L50-TAR RNA interactions in-vitro. These findings are consistent with genetic evidence that TAR plays critical roles both during reverse transcription and during HIV gene expression. Our results suggest that antiviral drugs targeting TAR RNA might be highly effective due to a dual inhibitory mechanism.

HAP2(GCS1)-dependent gamete fusion requires a positively charged carboxy-terminal domain.

HAP2(GCS1) is a deeply conserved sperm protein that is essential for gamete fusion. Here we use complementation assays to define major functional regions of the Arabidopsis thaliana ortholog using HAP2(GCS1) variants with modifications to regions amino(N) and carboxy(C) to its single transmembrane domain. These quantitative in vivo complementation studies show that the N-terminal region tolerates exchange with a closely related sequence, but not with a more distantly related plant sequence. In contrast, a distantly related C-terminus is functional in Arabidopsis, indicating that the primary sequence of the C-terminus is not critical. However, mutations that neutralized the charge of the C-terminus impair HAP2(GCS1)-dependent gamete fusion. Our results provide data identifying the essential functional features of this highly conserved sperm fusion protein. They suggest that the N-terminus functions by interacting with female gamete-expressed proteins and that the positively charged C-terminus may function through electrostatic interactions with the sperm plasma membrane.

Predicting late aortic complications after acute type A dissection surgery with volumetric measurements in a Singapore cohort.

Introduction: This study was conducted to evaluate the efficacy of postoperative computed tomography (CT) measurements of aortic lumen volumes in predicting aortic-related complications following acute type A aortic dissection (ATAAD) repair. Methods: We conducted a single-institution retrospective aortic volumetric analysis of patients after ascending aorta replacement performed during 2001-2015. The volumetric measurements of total lumen (total-L), true lumen (TL), false lumen (FL), as well as the TL:FL ratio from the first and second postoperative computer angiograms were obtained. A generalised structural equation model was created to analyse the predictive utility of TL:FL ratio. Results: One hundred and twenty-five patients underwent surgical intervention, of whom 97 patients were eventually discharged and analysed for postoperative complications. A total of 19 patients were included in the final analysis. Patients with late postoperative aortic complications had a significantly higher FL volume and total-L volume on the first (FL volume P = 0.041, total-L volume P = 0.05) and second (FL volume P = 0.01, total-L volume P = 0.007) postoperative scans. The odds of having aortic complications were raised by 1% with a 1 cm3 increase in total-L volume and by 2% with a 1 cm3 increase in FL volume. The TL:FL ratio was significantly lower in patients who developed complications. Conclusion: Postoperative CT volumetric measurements in patients who developed complications are characterised by a significant increase in the FL volume and total-L volume from the first postoperative scans. Patients with disproportionately expanded FL presenting with TL:FL ratios less than 1 were associated with aortic complications. Hence, the TL:FL ratio may be a reliable and useful parameter to monitor postoperative disease progression and to evaluate the risk of late complications in ATAAD patients.