Waitlisting and liver transplantation for MetALD in the United States: An analysis of the UNOS national registry.

BACKGROUND AND AIMS: The new steatotic liver disease (SLD) nomenclature introduced metabolic and alcohol-associated liver disease (MetALD), describing the intersection of metabolic dysfunction-associated steatotic liver disease and alcohol-associated liver disease. Waitlisting and liver transplantation for MetALD are not well defined. We aimed to develop and validate an algorithm for identifying SLD phenotypes and assessing trends in waitlisting and transplant outcomes. APPROACH AND RESULTS: We conducted a retrospective cohort study using the United Network for Organ Sharing registry, supplemented with detailed single-center data. We developed 5 candidate algorithms for SLD classification and calculated their diagnostic performance. Trends in waitlist registrations and transplants were estimated, and competing risk analyses and Cox regression models were conducted to assess waitlist removal and posttransplant outcomes among SLD phenotypes. The best-performing algorithm demonstrated substantial agreement (weighted kappa, 0.62) for SLD phenotypes, with acceptable sensitivity (73%) for MetALD. Between 2002 and 2022, waitlist registrations and transplants for MetALD increased 2.9-fold and 3.3-fold, respectively. Since 2013, there has been a significant increase in the absolute number of waitlist registrations (122 per year; 95% CI, 111-133) and transplants (107 per year; 95% CI, 94-120) for MetALD. Patients with MetALD experienced higher waitlist removal (adjusted subdistribution hazard ratio, 1.10; 95% CI, 1.03-1.17), all-cause mortality (adjusted hazard ratio, 1.13; 95% CI, 1.03-1.23), and graft failure (adjusted hazard ratio, 1.12; 95% CI, 1.03-1.21) than those with alcohol-associated liver disease. CONCLUSIONS: We developed and validated an algorithm for identifying SLD phenotypes in UNOS. MetALD is the third leading etiology among those waitlisted and underwent transplantation, exhibiting worse pretransplantation and posttransplantation outcomes compared to alcohol-associated liver disease. Identifying and addressing factors determining poor outcomes is crucial in this patient population.

Association of psychosocial risk factors and liver transplant evaluation outcomes in metabolic dysfunction-associated steatotic liver disease.

The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) is a standardized psychosocial assessment tool used in liver transplantation (LT) evaluation and has been primarily studied in patients with alcohol-associated liver disease. We aimed to evaluate the relationship between SIPAT score and metabolic syndrome severity and LT waitlist outcomes in a large cohort of patients with metabolic dysfunction-associated steatotic liver disease (MASLD). We performed a single-center retrospective cohort study of patients with MASLD evaluated for LT from 2014 to 2021. The utility of the previously defined total SIPAT cutoff (<21 [excellent/good candidates] vs. ≥21 [minimally acceptable/high-risk candidates]) was studied. Multivariable logistic regression analyses examined associations between continuous SIPAT scores and LT waitlisting outcomes. The Youden J statistic was used to identify the optimal SIPAT cutoff for patients with MASLD. A total of 480 patients evaluated for transplant with MASLD were included. Only 9.4% of patients had a SIPAT score ≥21. Patients with SIPAT score ≥21 had higher hemoglobin A1c compared to patients with lower psychosocial risk (median [IQR]: 7.8 [6.0-9.7] vs. 6.6 [5.8-7.9]; p = 0.04). There were no other differences in metabolic comorbidities between SIPAT groups. Increasing SIPAT score was associated with decreased odds of listing (OR: 0.82 per 5-point increase; p = 0.003) in multivariable models. A SIPAT of ≥12 was identified as the optimal cutoff in this population, resulting in an adjusted OR for a listing of 0.53 versus SIPAT <12 ( p = 0.001). In this large cohort of patients with MASLD evaluated for LT, few patients met the previously defined high SIPAT cutoff for transplant suitability. Nevertheless, increasing the SIPAT score was associated with waitlist outcomes. Our suggested SIPAT cutoff of ≥12 for patients with MASLD warrants further external validation using data from other centers.

Incidence of acute rejection and patient survival in combined heart-liver transplantation.

Combined heart-liver transplantation (CHLT) is indicated for patients with concomitant end-stage heart and liver disease or patients with amyloid heart disease where liver transplantation mitigates progression. Limited data suggest that the liver allograft provides immunoprotection for heart and kidney allografts in combined transplantation from the same donor. We hypothesized that CHLT reduces the incidence of acute cellular rejection (ACR) and the development of de novo donor-specific antibodies (DSAs) compared with heart-alone transplantation (HA). We conducted a retrospective analysis of 32 CHLT and 280 HA recipients in a single-center experience. The primary outcome was incidence of ACR based on protocol and for-cause myocardial biopsy. Rejection was graded by the International Society of Heart and Lung Transplantation guidelines with Grade 2R and higher considered significant. Secondary outcomes included the development of new DSAs, cardiac function, and patient and cardiac graft survival rates. Of CHLT patients, 9.7% had ACR compared with 45.3% of HA patients (p < 0.01). Mean pretransplant calculated panel reactive antibody (cPRA) levels were similar between groups (CHLT 9.4% vs. HA 9.5%; p = 0.97). Among patients who underwent testing, 26.9% of the CHLT and 16.7% of HA developed DSA (p = 0.19). Despite the difference in ACR, patient and cardiac graft survival rates were similar at 5 years (CHLT 82.1% vs. HA 80.9% [p = 0.73]; CHLT 82.1% vs. HA 80.9% [p = 0.73]). CHLT reduced the incidence of ACR in the cardiac allograft, suggesting that the liver offers immunoprotection against cellular mechanisms of rejection without significant impacts on patient and cardiac graft survival rates. CHLT did not reduce the incidence of de novo DSA, possibly portending similar long-term survival among cardiac allografts in CHLT and HA.

Does antithrombotic use enable earlier diagnosis of bladder cancer? A brief institutional assessment.

INTRODUCTION: Wallis et al (JAMA 2017) demonstrated use of antithrombotic medications (ATMs) is associated with increased prevalence of hematuria-related complications and subsequent bladder cancer diagnosis within 6 months. Stage of diagnosis was lacking in this highly publicized study. This study examined the association of ATM use on bladder cancer stage at the time of diagnosis. MATERIALS AND METHODS: We completed a retrospective chart review of patients with a bladder cancer diagnosis at our institution. Patient demographics and bladder cancer work up information were assessed. Patients were stratified based on use of ATMs at time diagnosis. Descriptive statistics were completed to identify association between ATM use and stage of bladder cancer diagnosis, as stratified by non-muscle invasive bladder cancer (NMIBC) versus muscle invasive bladder cancer (MIBC). RESULTS: A total of 1052 patient charts were reviewed. Eight hundred and forty-four were included and 208 excluded due to unavailability of diagnosis history. At diagnosis, 357 (42.3%) patients were taking ATMs. Patients on ATMs presented with NMIBC at similar rates as patients not taking ATMs (81.2% vs. 77.8%, p = 0.23). Subgroup analysis by ATM class similarly demonstrated no statistically significant differences in staging. CONCLUSION: While Wallis et al established that patients on blood thinners who present with hematuria are more likely to be diagnosed with genitourinary pathology, this factor does not appear to enable an earlier diagnosis of bladder cancer. Future study may assess hematuria at presentation (gross, microscopic), type of blood thinners, and low versus high risk NMIBC presentation.

Enhanced Solubilization of Class B Radical S-Adenosylmethionine Methylases by Improved Cobalamin Uptake in Escherichia coli.

The methylation of unactivated carbon and phosphorus centers is a burgeoning area of biological chemistry, especially given that such reactions constitute key steps in the biosynthesis of numerous enzyme cofactors, antibiotics, and other natural products of clinical value. These kinetically challenging reactions are catalyzed exclusively by enzymes in the radical S-adenosylmethionine (SAM) superfamily and have been grouped into four classes (A-D). Class B radical SAM (RS) methylases require a cobalamin cofactor in addition to the [4Fe-4S] cluster that is characteristic of RS enzymes. However, their poor solubility upon overexpression and their generally poor turnover has hampered detailed in vitro studies of these enzymes. It has been suggested that improper folding, possibly caused by insufficient cobalamin during their overproduction in Escherichia coli, leads to formation of inclusion bodies. Herein, we report our efforts to improve the overproduction of class B RS methylases in a soluble form by engineering a strain of E. coli to take in more cobalamin. We cloned five genes ( btuC, btuE, btuD, btuF, and btuB) that encode proteins that are responsible for cobalamin uptake and transport in E. coli and co-expressed these genes with those that encode TsrM, Fom3, PhpK, and ThnK, four class B RS methylases that suffer from poor solubility during overproduction. This strategy markedly enhances the uptake of cobalamin into the cytoplasm and improves the solubility of the target enzymes significantly.

Stereochemical and Mechanistic Investigation of the Reaction Catalyzed by Fom3 from Streptomyces fradiae, a Cobalamin-Dependent Radical S-Adenosylmethionine Methylase.

Fom3, a cobalamin-dependent radical S-adenosylmethionine (SAM) methylase, has recently been shown to catalyze the methylation of carbon 2″ of cytidylyl-2-hydroxyethylphosphonate (HEP-CMP) to form cytidylyl-2-hydroxypropylphosphonate (HPP-CMP) during the biosynthesis of fosfomycin, a broad-spectrum antibiotic. It has been hypothesized that a 5'-deoxyadenosyl 5'-radical (5'-dA•) generated from the reductive cleavage of SAM abstracts a hydrogen atom from HEP-CMP to prime the substrate for addition of a methyl group from methylcobalamin (MeCbl); however, the mechanistic details of this reaction remain elusive. Moreover, it has been reported that Fom3 catalyzes the methylation of HEP-CMP to give a mixture of the ( S)-HPP and ( R)-HPP stereoisomers, which is rare for an enzyme-catalyzed reaction. Herein, we describe a detailed biochemical investigation of a Fom3 that is purified with 1 equiv of its cobalamin cofactor bound, which is almost exclusively in the form of MeCbl. Electron paramagnetic resonance and Mössbauer spectroscopies confirm that Fom3 contains one [4Fe-4S] cluster. Using deuterated enantiomers of HEP-CMP, we demonstrate that the 5'-dA• generated by Fom3 abstracts the C2″- pro-R hydrogen of HEP-CMP and that methyl addition takes place with inversion of configuration to yield solely ( S)-HPP-CMP. Fom3 also sluggishly converts cytidylyl-ethylphosphonate to the corresponding methylated product but more readily acts on cytidylyl-2-fluoroethylphosphonate, which exhibits a lower C2″ homolytic bond-dissociation energy. Our studies suggest a mechanism in which the substrate C2″ radical, generated upon hydrogen atom abstraction by the 5'-dA•, directly attacks MeCbl to transfer a methyl radical (CH3•) rather than a methyl cation (CH3+), directly forming cob(II)alamin in the process.

Pseudomonas aeruginosa: An Unusual Culprit of Left-Sided Native Valve Infective Endocarditis.

Endocarditis refers to infection or inflammation of the endocardium, and various pathogens can be involved in infective endocarditis (IE). Endocarditis is usually caused by bacteremia in patients with risk factors, including IV drug abuse, indwelling central venous or urinary catheters, recent dental infections, and implantable cardiac devices. Pseudomonas aeruginosa (P. aeruginosa) is an extremely rare causative organism in IE, predominantly among IV drug users and involving right-sided valves. Left-sided native valve P. aeruginosa IE without established risk factors is uncommon. We present a case of a 68-year-old male with no traditional IE risk factors who presented with intermittent fevers. Blood cultures grew P. aeruginosa, and transesophageal echocardiography revealed posterior mitral valve vegetation. The patient received broad-spectrum IV antibiotics, which were eventually narrowed down to IV cefepime, guided by culture antimicrobial sensitivities. Although the literature describes various risks for P. aeruginosa IE, it can still occur in the absence of traditional predisposing factors. Due to this organism's rapid resistance acquisition and the complication of septic emboli, an expeditious diagnosis and treatment with antibiotics and/or valve surgery are vital to reducing mortality associated with this entity.

A Systematic Review of Anatomical Reflux Patterns in Primary Chronic Venous Disease.

OBJECTIVE: Patients with chronic venous disease can present with different underlying haemodynamic abnormalities affecting the deep, superficial and perforator veins. This review explores the relationship between reflux patterns, extent of venous reflux and clinical manifestations of chronic venous disease. METHODS: The Medline and EMBASE databases were systematically searched from 1946 to 1st April 2024. References of shortlisted papers were searched for relevant articles. Studies were included if they were in English language, included participants ≥16 years of age, documented reflux patterns in ≥2 of the following: deep, superficial and/or perforator systems, and related patterns to presentation or severity. Exclusion criteria included patients with isolated deep venous thrombosis, post-thrombotic syndrome or stenotic or obstructive disease. RESULTS: 18 studies were identified (11,177 participants, range 55 to 3016). Meta-analysis showed significant odds ratios (OR) for C4-6 disease being associated with deep reflux (OR 2.41, 95% confidence interval (CI) 1.53-3.78) and perforator reflux (OR 3.37, 95% CI 2.16-5.27), but not superficial reflux (OR 2.11, 95% CI 0.87-5.14), versus C0-3 disease. Severe chronic venous disease (C4-6) was significantly associated with isolated deep, combined deep/superficial and combined superficial/perforator reflux. The highest risk of CVD progression (defined as de novo development of varicose veins and progression to greater CVD severity) was shown by two studies to be related to combined deep/superficial reflux. CONCLUSIONS: While limited by the heterogenous nature of the studies, this review confirms that reflux pattern is a significant predictor of clinical class, and higher CEAP stages are associated with higher prevalence of superficial, deep and perforator reflux. Isolated deep and combined reflux also appear to predict the onset of leg ulceration. Future studies should relate reflux patterns to treatment outcomes, including recurrence risk. This could help inform health policies and management guidelines so that reflux patterns, in conjunction with other demographic and haemodynamic parameters, could be used to risk stratify patients and identify individuals that may benefit from earlier treatment.

Tissue inhibitor of metalloproteinases-3 moderates the proinflammatory status of macrophages.

Tissue inhibitor of metalloproteinases-3 (TIMP-3) has emerged as a key mediator of inflammation. Recently, we reported that the resolution of inflammation is impaired in Timp3(-/-) mice after bleomycin-induced lung injury. Here, we demonstrate that after LPS instillation (another model of acute lung injury), Timp3(-/-) mice demonstrate enhanced and persistent neutrophilia, increased numbers of infiltrated macrophages, and delayed weight gain, compared with wild-type (WT) mice. Because macrophages possess broad immune functions and can differentiate into cells that either stimulate inflammation (M1 macrophages) or are immunosuppressive (M2 macrophages), we examined whether TIMP-3 influences macrophage polarization. Comparisons of the global gene expression of unstimulated or LPS-stimulated bone marrow-derived macrophages (BMDMs) from WT and Timp3(-/-) mice revealed that Timp3(-/-) BMDMs exhibited an increased expression of genes associated with proinflammatory (M1) macrophages, including Il6, Il12, Nos2, and Ccl2. Microarray analyses also revealed a baseline difference in gene expression between WT and Timp3(-/-) BMDMs, suggesting altered macrophage differentiation. Furthermore, the treatment of Timp3(-/-) BMDMs with recombinant TIMP-3 rescued this altered gene expression. We also examined macrophage function, and found that Timp3(-/-) M1 cells exhibit significantly more neutrophil chemotactic activity and significantly less soluble Fas ligand-induced caspase-3/7 activity, a marker of apoptosis, compared with WT M1 cells. Macrophage differentiation into immunosuppressive M2 cells is mediated by exposure to IL-4/IL-13, and we found that Timp3(-/-) M2 macrophages demonstrated a lower expression of genes associated with an anti-inflammatory phenotype, compared with WT M2 cells. Collectively, these findings indicate that TIMP-3 functions to moderate the differentiation of macrophages into proinflammatory (M1) cells.

Comprehensive Review of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease.

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.

Filling Gaps and Setting Boundaries: Examining Utilization of Health and Social services at JeffHOPE Student Run Clinics.

The objective of this study was to describe the frequency that healthcare and social support services offered by JeffHOPE, a student run clinic for people experiencing homelessness in Philadelphia, PA, were utilized by patients. This study also aimed to investigate where patients would seek medical care on a given day had they not been able to access JeffHOPE. This study was conducted via mixed methods consisting of retrospective chart review of patient encounter records and a patient survey conducted weekly throughout 2019, both at a single clinic site, and retrospective chart review of January through March 2020 records at 5 clinic sites. This study found that the frequency of services utilized varied between clinic sites, and that Pharmacy and Procedure committees were the most utilized when examining the combined clinic data. Additionally, the survey found that JeffHOPE provided medical care to those that otherwise would not have sought it. Clinics also served as an alternative to accessing care for non-emergent issues in an Emergency Department (ED) for some patients, but for others it replaced seeing their primary care provider (PCP). This study confirmed that the services offered by JeffHOPE are well-utilized by patients experiencing homelessness in Philadelphia. It also revealed that while the organization's medical services filled care gaps and potentially decreased unnecessary ED visits, they were also sometimes accessed in lieu of a PCP visit. A focused effort on linkage to formal primary care services for all JeffHOPE patients and expanding collection of more granular data to all clinics represent important future endeavors for this student run organization.

Automatic 1D 1H NMR Metabolite Quantification for Bioreactor Monitoring.

High-throughput metabolomics can be used to optimize cell growth for enhanced production or for monitoring cell health in bioreactors. It has applications in cell and gene therapies, vaccines, biologics, and bioprocessing. NMR metabolomics is a method that allows for fast and reliable experimentation, requires only minimal sample preparation, and can be set up to take online measurements of cell media for bioreactor monitoring. This type of application requires a fully automated metabolite quantification method that can be linked with high-throughput measurements. In this review, we discuss the quantifier requirements in this type of application, the existing methods for NMR metabolomics quantification, and the performance of three existing quantifiers in the context of NMR metabolomics for bioreactor monitoring.

TsrM as a Model for Purifying and Characterizing Cobalamin-Dependent Radical S-Adenosylmethionine Methylases.

Cobalamin-dependent radical S-adenosylmethionine (SAM) methylases play vital roles in the de novo biosynthesis of many antibiotics, cofactors, and other important natural products, yet remain an understudied subclass of radical SAM enzymes. In addition to a [4Fe-4S] cluster that is ligated by three cysteine residues, these enzymes also contain an N-terminal cobalamin-binding domain. In vitro studies of these enzymes have been severely limited because many are insoluble or sparingly soluble upon their overproduction in Escherichia coli. This solubility issue has led a number of groups either to purify the protein from inclusion bodies or to purify soluble protein that often lacks proper cofactor incorporation. Herein, we use TsrM as a model to describe methods that we have used to generate soluble protein that is purified in an active form with both cobalamin and [4Fe-4S] cluster cofactors bound. Additionally, we highlight the methods that we developed to characterize the enzyme following purification.

Characterization of the mechanical behavior of the optic nerve sheath and its role in spaceflight-induced ophthalmic changes.

Visual impairment and intracranial pressure (VIIP) syndrome is characterized by a number of permanent ophthalmic changes, including loss of visual function. It occurs in some astronauts during long-duration spaceflight missions. Thus, understanding the pathophysiology of VIIP is currently a major priority in space medicine research. It is hypothesized that maladaptive remodeling of the optic nerve sheath (ONS), in response to microgravity-induced elevations in intracranial pressure (ICP), contributes to VIIP. However, little is known about ONS biomechanics. In this study, we developed a custom mechanical testing system that allowed for unconfined lengthening, twisting, and circumferential distension of the porcine ONS during inflation and axial loading. Data were fit to a four-fiber family constitutive equation to extract material and structural parameters. Inflation testing showed a characteristic "cross-over point" in the pressure-diameter curves under different axial loads in all samples that were tested; the cross-over pressure was [Formula: see text] mmHg ([Formula: see text]). Large sample-to-sample variations were observed in the circumferential strain, while only modest variations were observed in the circumferential stress. Multiphoton microscopy revealed that the collagen fibers of the ONS were primarily oriented axially when the tissue was loaded. The existence of this cross-over behavior is expected to be neuroprotective, as it would avoid optic nerve compression during routine changes in gaze angle, so long as ICP was within the normal range. Including these observations into computational models of VIIP will help provide insight into the pathophysiology of VIIP and could help identify risk factors and potential interventions.

Validation of optimal DCE-MRI perfusion threshold to classify at-risk tumor imaging voxels in heterogeneous cervical cancer for outcome prediction.

PURPOSE: To classify tumor imaging voxels at-risk for treatment failure within the heterogeneous cervical cancer using DCE MRI and determine optimal voxel's DCE threshold values at different treatment time points for early prediction of treatment failure. MATERIAL AND METHOD: DCE-MRI from 102 patients with stage IB2-IVB cervical cancer was obtained at 3 different treatment time points: before (MRI 1) and during treatment (MRI 2 at 2-2.5 weeks and MRI 3 at 4-5 weeks). For each tumor voxel, the plateau signal intensity (SI) was derived from its time-SI curve from the DCE MRI. The optimal SI thresholds to classify the at-risk tumor voxels was determined by the maximal area under the curve using ROC analysis when varies SI value from 1.0 to 3.0 and correlates with treatment outcome. RESULTS: The optimal SI thresholds for MRI 1, 2 and 3 were 2.2, 2.2 and 2.1 for significant differentiation between local recurrence/control, respectively, and 1.8, 2.1 and 2.2 for death/survival, respectively. CONCLUSION: Optimal SI thresholds are clinically validated to quantify at-risk tumor voxels which vary with time. A single universal threshold (SI=1.9) was identified for all 3 treatment time points and remained significant for the early prediction of treatment failure.

Development of a catadioptric endoscope objective with forward and side views.

Autofluorescence endoscopy is a promising functional imaging technique to improve screening of pre-cancerous or early cancer lesions in the gastrointestinal (GI) tract. Tissue autofluorescence signal is weak compared to white light reflectance imaging. Conventional forward-viewing endoscopes are inefficient in the collection of light from objects of interest along on the GI luminal wall. A key component of a complete autofluorescence endoscope is the light collection module. In this paper, we report the design, optimization, prototype development, and testing of an endoscope objective that is capable of acquiring simultaneous forward and radial views. The radial-view optical design was optimized for a balance between image quality and light collection. Modulation transfer function (MTF), entrance pupil radius, manufacturability, and field-of-view were parameters used in the lens optimization. In comparison with the typical forward-viewing endoscopes, our nonsequential ray trace simulations suggest the proposed radial-view design is more practical in the light collection. To validate the proposed simulation methods, a 3:1 scaled-up prototype was fabricated. Contrast measurements were taken with the prototype, and then compared with the simulated MTF.

High-throughput acousto-optic-tunable-filter-based time-resolved fluorescence spectrometer for optical biopsy.

Time-resolved fluorescence spectroscopy has been studied to perform minimally invasive optical biopsy in clinical diagnostics. A critical barrier preventing current time-resolved techniques from clinical studies is their impractically long data acquisition time. We have developed an acousto-optic-tunable-filter (AOTF)-based time-resolved fluorescence spectrometer, which is capable of near real-time data acquisition. Both first-order diffraction beams are collected in this AOTF spectrometer, which results in significantly improved overall throughput. Using standard fluorescence dyes, we have demonstrated that this spectrometer can acquire 200 nm time-resolved spectra within 4 s, while its throughput is comparable to a grating-based spectrometer.