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The prevalence of comorbid metabolic dysfunction–associated steatotic liver disease (MASLD) and obesity has increased exponentially over the last several years, with current estimates demonstrating that up to 40% of adults in the United States have MASLD. Metabolic dysfunction–associated steatohepatitis is now a leading indication for liver transplantation, and rates of obesity and MASLD pre-transplant and post-transplant are on the rise. Our understanding of the physiology of obesity and metabolic disease and the availability of effective obesity treatments have evolved over the same time frame. With the availability of new anti-obesity medications, there has been a debate over the role of pharmacotherapy versus interventional approaches in the treatment of obesity and MASLD in the liver transplantation population. In October 2024, the American Society of Transplantation (AST) Liver and Intestinal Community of Practice held a virtual Controversies Conference on obesity and liver transplantation. Experts in the field presented the available data, and smaller working groups had interactive breakout sessions that identified knowledge gaps and developed recommendations. This perspective prepared on behalf of the participants of the AST Controversies Conference on obesity and liver transplant aims to summarize the available evidence for surgical and pharmaceutical treatment in the liver transplantation population.

ABSTRACT Objective There is limited consensus on endoscopic skull base surgery (ESBS) reconstruction principles. This study aims to generate comprehensive themes regarding ESBS reconstruction by pooling the experiences of ESBS experts, with comparison to a literature review of current published evidence. Methods Structured qualitative interviews of ESBS experts regarding postoperative management and reconstruction of various defect locations were conducted. Results A total of 68 experts comprising 40 academic teams across 13 countries with an average of 18 years of ESBS experience were included. We propose 10 stepwise algorithms for common skull base reconstruction scenarios based on these expert interviews. When available, the nasoseptal flap is used for all high_flow cerebrospinal leak defects. Multilayered reconstruction is favored at all anatomical subsites with increasing number of layers for increasing defect size and complexity. Heterogeneity exists in terms of inlay technique and materials, free grafting versus various pedicled flap options for low‐flow defects or in the absence of a nasal septum, nasal packing, tissue sealant, lumbar drain use, and postoperative management. Commonalities and discrepancies between experts were summarized. Conclusion Skull base reconstruction and post‐ESBS management is highly complex with a wide variety of practice patterns and expert strategies. Further research of higher quality evidence is warranted to identify optimal management patterns, though the current work aims to inform surgeons on these controversial areas by drawing from numerous experiences.

AbstractThe sliding filament theory explains skeletal muscle fibre force change as a function of length based on the overlap of actin and myosin filaments. Although this length‐tension (LT) relationship has been well investigated in animal models, it is not known whether this microscopic sarcomere LT property can be scaled up five orders of magnitude to explain the LT behaviour of a long human muscle such as the gracilis. The goal of this study is to validate the sarcomere LT curve in humans based on human filament length combined with in vivo experimental data. Intraoperative measurements of maximal tetanic force and muscle‐tendon unit length at four different joint configurations (JC) were obtained from 19 patients undergoing free functioning muscle transfer surgery. With physiologically measured fibre length and estimated sarcomere shortening resulting from tendon compliance, we show that 79.7% variance in isometric force data is explained by a simple human sarcomere LT model. This study demonstrates that the human whole muscle LT relationship can be modelled by the sliding filament theory given patient‐specific fibre length, filament length, tendon compliance and sarcomere shortening. imageKey points Whole human gracilis muscle isometric length‐tension relationships were measured in the operating room. Grouped whole muscle raw length‐tension curves showed no obvious form. The width of each experimental length‐tension curve was highly variable across subjects and used to predict fibre length (serial sarcomere number). After whole muscle length‐tension curves were normalized to each patient's serial sarcomere number, the whole human muscle length‐tension curve was well predicted by the sliding filament theory.

Introduction: WM is a rare subtype of lymphoma, identified by the presence of IgM paraprotein, infiltration of clonal, small lymphoplasmacytic B cells in the bone marrow, and the somatic mutation, MYD88 L265P, which is observed in over 90% of WM patients. We previously identified two rare variants at 6p25.3 (EXOC2) and 14q32.13 (TCL1) that were significantly associated with an increased risk of WM/LPL (PMID: 30305637). However, the genetic basis for WM/LPL predisposition remains largely unknown. We conducted the largest WM/LPL GWAS to discover further germline susceptibility loci for WM/LPL. Methods: Our meta-analysis discovery set included 1,707 cases and 58,328 controls of European ancestry from the InterLymph Consortium, genotyped on a high-density SNP array and imputed to TOPMed, providing over 10 million common variants for association testing. Germline genetic loci with suggestive significance (P<5x10-6) were selected for replication in four independent sets (570 cases and 771,770 controls; UK Biobank, Copenhagen Hospital Biobank, FinnGen, Mayo Clinic), giving us a total of 2,277 WM/LPL cases and 831,098 controls. Conditional and sensitivity analyses were performed considering family history and sex. A transcriptome-wide association study (TWAS) was performed using FUSION with expression quantitative trait loci (eQTL) data from GTEx and Young Finns Study in whole blood, lymphocytes, and other tissues. Functional annotations were done using FUMA, F-MAGMA, FORGE, and OpenTarget. Colocalization was measured using CoLoC with whole blood gene expression data. Results & Discussion: We identified 11 germline genetic loci associated with WM/LPL risk that replicated and reached genome-wide significance (P< 5x10-8), including the two known loci on 6p25.3 and 14q32.13 and nine novel loci in the following regions: 6p25.3 (n=2 independent loci), 2q37.1, 9p13.2, 6p21.32, 10q23.31, 16q21, 1p31.1, and 15q15.1. Four of the discovered variants showed strong associations with WM/LPL [odds ratios (ORs) >10]. Enrichment was observed for enhancer and promoter elements in B-cells (FDR q < 0.01), and gene-based and colocalization analyses identified several potential biological pathways. Colocalization analyses show the intronic PAX5 risk variant on 9p (OR=1.5, P= 2.3x10-25) associated with whole blood eQTL expression of PAX5, which plays an essential role in regulating lymphoid progenitors to the B-lymphocyte lineage, as well as RP11-297B17.3 (RNA gene, antisense to PAX5). In addition, GWAS have shown this variant is in linkage disequilibrium (LD) with GWAS loci for CD20 on IgD+ CD38- B cell that represents a specific immunophenotype that helps identify and characterize B cells involved with WM and other similar conditions. The 2q37.1 (SP140) locus (OR=1.6, P=1.2x10-33) contains variants linked to chronic lymphocytic leukemia (CLL) and autoimmune diseases, including multiple sclerosis and Crohn's disease. This locus is important in chromatin-mediated gene regulation, suggesting a significant role in the immune system. The specific variant influences exon-skipping and potentially protein expression, altering the gene's function. The variants on 10q23.31 in FAS (OR=1.3, P=4.4x10-13) and 15q15.1 (OR=1.2, P=8.5x10-11) in BCL2 modifying factor (BMF), are in strong LD with known CLL susceptibility variants. The 15q variant is also linked with multiple lymphoid leukemia GW significant SNPs. Sex-specific analyses identified one novel locus at 20q13.33 associated with the expression of ZGPAT and UCKL1 in males (OR=1.9, P=9.5x10-10). TWAS identified associations with CRHR1 and CDKN2A; overexpression of both are shown to be associated with an increased risk of WM/LPL. Expression of CDKN2A has been linked to childhood acute lymphoblastic leukemia, while CRHR1 has been associated with breast cancer risk. Conclusions: Our study, the largest GWAS of WM to date, has identified 11 susceptibility loci, including two previously known and nine novel regions. The findings underscore the genetic complexity of WM, with the PAX5 and SP140 loci implicated in both chromatin-mediated gene regulation and immune system functions. These insights not only enhance our understanding of WM predisposition but also pave the way for future research focused on functional understanding of these loci, potentially leading to new therapeutic strategies.

Introduction: Waldenström macroglobulinemia (WM)remains incurable with current therapies. Treatment options for patients beyond initial therapy are limited, underscoring the need for new agents with novel mechanisms of action. Iopofosine I 131 is a novel radiopharmaceutical composed of a lipid raft-targeting phospholipid ether covalently bound to 131I, a beta-emitting radioisotope. Herein, we report the results of the CLOVER-WaM study [NCT02952508] in patients with previously treated WM. Methods: Eligible WM patients had received >2 prior therapies and had symptomatic disease requiring therapy according to consensus recommendations for WM. Treatment consisted of 2 cycles of iopofosine I 131 administered at 15 mCi/m2 on days 1 and 15 of each 57-day cycle. Dose reduction to 10 mCi/m2 was allowed in the second cycle in patients with incomplete hematologic recovery or if the expected total dose exceeded 132 mCi. Supportive care with growth factors and transfusions was permitted per treating physician discretion. The primary endpoint was major response rate (MRR, defined as partial response or better) as determined by the modified VIth International Workshop on Waldenström Macroglobulinemia Response Criteria. Secondary endpoints included overall response rate (ORR), treatment-free survival (TFS), duration of response (DOR), and clinical benefit rate (CBR, defined as stable disease or better). Efficacy endpoints were assessed in the modified intent-to-treat (mITT) population, defined as all patients who received ≥60 mCi total administered dose of iopofosine I 131. MRR was analyzed with a 95% 2-sided confidence interval (CI) using the Clopper-Pearson interval method. In this population, MRR >20% was considered statistically significant. Time-dependent efficacy endpoints were analyzed using the Kaplan-Meier method. Safety was evaluated using CTCAE v4.03 in patients who received >1 dose of iopofosine I 131. The data cut-off for this analysis was May 31, 2024. Results: In 65 patients enrolled (safety population), the median age was 70 (range, 50-88) years; 48 (73.8%) were male, and 17 (26.2%) were female. Sixty-one (93.8%) were White, 1 (1.5%) was Black/African American, and 3 (4.6%) were other or unknown. Fifty-five patients met mITT criteria and were evaluable for efficacy. The median number of prior therapies was 4 (range, 2-15). Bruton's tyrosine kinase inhibitor (BTKi) exposure was noted in 39 (71%) patients, of whom 31 (56%) were BTKi-refractory. Sixteen (29%) patients had MYD88-wild type, and 5 (9%) had CXCR4-mutated disease. The MRR was 56.4% (95% CI, 42.3-69.7). ORR was 80%; among MYD88-wild type patients, ORR was 81%, and among post-BTKi patients, ORR was 72%. CBR was 98%. The median DOR and TFS were not reached at a median follow-up of 8.8 months, with an estimated 72% of responding patients remaining progression-free at 18 months. In the safety population, any-grade adverse events, regardless of causality, were reported in 57 (87%) patients. Grade 3 or higher treatment-emergent adverse events (TEAEs) occurring in >10% of patients included thrombocytopenia (80%), neutropenia (69.2%), anemia (44.6%), lymphopenia (13.8%), infections (12.3%), and febrile neutropenia (10.8%). Adverse event-related death occurred in 1 patient due to bacterial sepsis. Conclusion: Iopofosine I 131 demonstrated durable efficacy in previously treated WM patients, with no current standard of care therapy. The treatment was well-tolerated with a manageable toxicity profile across broad biologic and clinical subgroups, irrespective of risk stratification. Based on the results of this trial, iopofosine I 131 shows promise as a novel treatment for WM patients.

Abstract The determination of the genetic subtypes of primary central nervous system lymphoma (PCNSL) and their relationship to differential chemoimmunotherapeutic response has not been established. There is a particular need for genomic biomarkers that identify patients with newly diagnosed PCNSL at high risk of early progression and death. We applied targeted next-generation sequencing for detection of recurrent single-nucleotide variants, copy number alterations, and zygosity abnormalities in diagnostic specimens from 78 patients with PCNSL treated with a standard methotrexate-based regimen, to identify prognostically significant molecular subgroups. All patients received induction immunochemotherapy, and 44 proceeded to dose-intensive consolidation. Genomic aberrations at 4 loci were associated with 91% of lymphoma progression events and all 15 deaths: (1) chromosome 6p copy-neutral loss of heterozygosity (CN-LOH) or focal homozygous deletion (HD) at 6p21.3, and mutations of tumor suppressor genes (2) BTG1, (3) ETV6, and (4) TP53. Cox regression multivariate analysis demonstrated a high risk of progression in patients with aberrations at these loci. Genomic aberrations at these loci were also associated with significantly shorter survival. Lower expression of HLA-DR was associated with 6p CN-LOH/6p21.3 HD and inferior prognosis. These genomic aberrations identify a high-risk molecular subgroup that may inform risk stratification in PCNSL. Further elucidation of the mechanisms of therapeutic resistance associated with the high-risk genetic phenotype is requisite to facilitate precision medicine and progress in therapy.

Context: Epidemiological studies have shown an increased risk of musculoskeletal injury after concussion. The purpose of this study was to determine whether the reverse relationship exists, specifically whether there is an increased risk of concussion after an anterior cruciate ligament (ACL) injury in a population-based cohort. Design: Retrospective cohort. Methods: The Rochester Epidemiology Project was searched between 2000 and 2017 for International Classification of Diseases, 9th and 10th Revision codes relevant to the diagnosis and treatment of concussion and ACL tear. A total of 1294 unique patients with acute, isolated ACL tears and no previous history of concussion were identified. Medical records for cases were reviewed to confirm ACL tear diagnosis and to determine history of concussion after the ACL injury. Cases were matched by age, sex, and Rochester Epidemiology Project availability to patients without an ACL tear (1:3 match), resulting in 3882 controls. Medical records of matched control patients were reviewed to rule out history of ACL injury. The hazard ratio of concussion injury following an ACL injury was determined. Results: Nine patients with an ACL injury suffered concussion up to 3 years after the ACL injury. The rate of concussion was no different between ACL-injured cases (0.7%) compared with matched controls with no ACL injury (1.2%), which corresponded to a hazard ratio of 0.55 (95% confidence interval, 0.3–1.1; P = .10). Conclusions: Based on the current evidence, there does not appear to be a significant association between ACL injury and subsequent concussion, which suggests that a concussion uniquely affects the risk of future subsequent musculoskeletal injury.

The intrinsic force production capability of human muscle can be expressed as “Specific Tension,” or, the maximum force generated per cross-sectional area of muscle fibers. This value can be used to determine, for example, whether muscle quality changes during exercise, atrophy, disease, or hypertrophy. A value of 22.5 N/cm 2 for mammalian muscle has generally become accepted based on detailed studies of small mammals. Determining the specific tension of human muscle is much more challenging as almost all determinations are indirect. Calculation of human muscle specific tension requires an understanding of that muscle’s contribution to joint torque, its activation magnitude, tendon compliance, and joint moment arm. Determining any of these parameters is technically challenging in humans and thus, it is no surprise that human specific tension values reported vary from 2 to 73 N/cm 2 . In this systematic review, we screened 1,506 published papers and identified the 30 studies published between 1983 and 2023 that used appropriate methods and which reported 96 human specific tension values. We weighted each parameter based on whether it was directly measured, estimated, or calculated based on the literature, with decreasing weighting used, the more indirect the methods. Based on this exhaustive review of the relevant human literature, we suggest that the most accurate value that should be used for human muscle specific tension is 26.8 N/cm 2 .