Publications by authors named "Biggins S"

Chromosome segregation relies on kinetochores that assemble on specialized centromeric chromatin containing a histone H3 variant. In budding yeast, a single centromeric nucleosome containing Cse4 assembles at a sequence-defined 125 bp centromere. Yeast centromeric sequences are poor templates for nucleosome formation in vitro, suggesting the existence of mechanisms that specifically stabilize Cse4 nucleosomes in vivo.

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Connections between the mechanical properties of DNA and biological functions have been speculative due to the lack of methods to measure or predict DNA mechanics at scale. Recently, a proxy for DNA mechanics, cyclizability, was measured by loop-seq and enabled genome-scale investigation of DNA mechanics. Here, we use this dataset to build a computational model predicting bias-corrected intrinsic cyclizability, with near-perfect accuracy, solely based on DNA sequence.

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Background & Aims: Currently, patients with hepatocellular carcinoma (HCC) in the United States are assigned a uniform score relative to the median Model for End-Stage Liver Disease (MELD) at transplant after a minimum 6-month waiting period. The authors developed a risk stratification model for patients with HCC using the available and objective variables at time of listing.

Methods: Adult liver transplant candidates with approved HCC exception in the Organ Procurement and Transplantation Network database from 2015-2022 were identified.

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Introduction: Perception of the ascites burden and its effects on quality of life may be different between sexes. This study assessed sex differences in perception of ascites burden and its impact on health-related quality of life (HRQoL) in patients with recurrent or refractory ascites.

Methods: The North American Consortium for the Study of End-stage Liver Disease prospectively enrolled outpatients with cirrhosis and large ascites requiring repeat large volume paracenteses.

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Article Synopsis
  • Accurate mitosis requires chromosomes to achieve "biorientation," where sister chromatids are linked to opposite microtubules through kinetochores.
  • Kinetochores initially attach to the sides of microtubules and must subsequently convert these attachments to the plus ends through a trial-and-error method, emphasizing the need for error-correction mechanisms.
  • Research shows that kinetochores have a stronger grip on microtubules pulled towards their plus ends, and this sensitivity to microtubule polarity may help stabilize correct connections early in mitosis.
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  • The study examines how cirrhosis affects kidney functionality, particularly focusing on tubular structures, which are crucial for managing metabolites and electrolytes, rather than just glomerular filtration rate (GFR).
  • Researchers collected plasma and urine samples from cirrhotic patients and matched controls to evaluate tubular injury and viability markers, specifically KIM-1 (kidney injury molecule-1) and EGF (epidermal growth factor).
  • Findings showed that patients with cirrhosis had significantly higher levels of KIM-1 and EGF, indicating tubular injury yet demonstrated preserved tubular secretory function, suggesting a mix of chronic injury while maintaining functionality in stable cirrhosis cases.
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  • Living donor liver transplant (LDLT) has been growing in the U.S., providing a critical way to increase the number of available organs and reduce wait times for patients needing liver transplants.
  • The transplant community is exploring ways to broaden eligibility for both donors and recipients, including using older donors and expanding criteria for candidates who might benefit from a transplant.
  • There are promising opportunities for LDLT in transplant oncology, especially for patients with specific types of advanced cancer, while ongoing advancements in surgical techniques aim to enhance access to transplants for those with end-stage liver disease.
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Eukaryotic chromosome segregation requires kinetochores, multi-megadalton protein machines that assemble on the centromeres of chromosomes and mediate attachments to dynamic spindle microtubules. Kinetochores are built from numerous complexes, and there has been progress in structural studies on recombinant subassemblies. However, there is limited structural information on native kinetochore architecture.

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Shiga toxin-producing (STEC) is an important waterborne pathogen capable of causing serious gastrointestinal infections with potentially fatal complications, including haemolytic-uremic syndrome. All STEC serogroups harbour genes that encode at least one Shiga toxin ( and/or ), which constitute the primary virulence factors of STEC. Loop-mediated isothermal amplification (LAMP) enables rapid real-time pathogen detection with a high degree of specificity and sensitivity.

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Background & Aims: Severe alcohol-associated hepatitis (SAH) represents a lethal subset of alcohol-associated liver disease. Although corticosteroids are recommended by guidelines, their efficacy and safety remain questionable and so liver transplantation (LT) has been increasingly utilized. The timing and indication of corticosteroid use, specifically in patients being considered for LT requires further clarification.

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Background: Small stature and female sex correlate to decreased deceased donor liver transplant (DDLT) access and higher waitlist mortality. However, efforts are being made to improve access and equity of allocation under the new continuous distribution (CD) system. Liver anteroposterior diameter (APD) is a method used by many centers to determine size compatibility for DDLT but is not recorded systematically, so it cannot be used for allocation algorithms.

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Article Synopsis
  • * Hepatorenal syndrome (HRS), a severe type of AKI specifically found in patients with advanced cirrhosis and ascites, has an especially high mortality rate, making early detection vital.
  • * In 2023, experts from the International Club of Ascites and the Acute Disease Quality Initiative met to create new diagnostic criteria for HRS-AKI and to establish better practices for treatment and follow-up care for these patients.
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Eukaryotic chromosome segregation requires kinetochores, multi-megadalton protein machines that assemble on the centromeres of chromosomes and mediate attachments to dynamic spindle microtubules. Kinetochores are built from numerous complexes, and understanding how they are arranged is key to understanding how kinetochores perform their multiple functions. However, an integrated understanding of kinetochore architecture has not yet been established.

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Candidates for multivisceral transplant (MVT) have experienced decreased access to transplant in recent years. Using Organ Procurement and Transplantation Network data, transplant and waiting list outcomes for MVT (ie, liver-intestine, liver-intestine-pancreas, and liver-intestine-kidney-pancreas) candidates listed between February 4, 2018, and February 3, 2022, were analyzed, including model for end-stage liver disease/pediatric end-stage liver disease and exception scores by era (before and after acuity circle [AC] implementation on February 4, 2020) and age group (pediatric and adult). Of 284 MVT waitlist registrations (45.

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During mitosis, kinetochore-attached microtubules form bundles (k-fibers) in which many filaments grow and shorten in near-perfect unison to align and segregate each chromosome. However, individual microtubules grow at intrinsically variable rates, which must be tightly regulated for a k-fiber to behave as a single unit. This exquisite coordination might be achieved biochemically, via selective binding of polymerases and depolymerases, or mechanically, because k-fiber microtubules are coupled through a shared load that influences their growth.

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Introduction: Hospitalized patients with cirrhosis can develop respiratory failure (RF), which is associated with a poor prognosis, but predisposing factors are unclear.

Methods: We prospectively enrolled a multicenter North American cirrhosis inpatient cohort and collected admission and in-hospital data (grading per European Association for the Study of Liver-Chronic Liver Failure scoring system, acute kidney injury [AKI], infections [admission/nosocomial], and albumin use) in an era when terlipressin was not available in North America. Multivariable regression to predict RF was performed using only admission day and in-hospital events occurring before RF.

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During mitosis, kinetochore-attached microtubules form bundles (k-fibers) in which many filaments grow and shorten in near-perfect unison to align and segregate each chromosome. However, individual microtubules grow at intrinsically variable rates, which must be tightly regulated for a k-fiber to behave as a single unit. This exquisite coordination might be achieved biochemically, via selective binding of polymerases and depolymerases, or mechanically, because k-fiber microtubules are coupled through a shared load that influences their growth.

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The exception point system for liver allocation in the United States allows for additional waitlist priority for candidates where the Model for End-Stage Liver Disease or Pediatric End-stage Liver Disease does not effectively represent their urgency or need for a transplant. In May 2019, the review process for liver exception cases transitioned from 11 Regional Review Boards (RRBs) to 1 National Liver Review Board (NLRB), intended to increase consistency nationwide, improve efficiency, and balance transplant access for candidates with and without exception scores. This report provides a review of liver exception request and review practices, waitlist outcomes, and transplant activity in the first 2 years after implementation of the NLRB and acuity circle-based distribution in the United States.

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Eukaryotic chromosome segregation requires the kinetochore, a megadalton-sized machine that forms on specialized centromeric chromatin containing CENP-A, a histone H3 variant. CENP-A deposition requires a chaperone protein HJURP that targets it to the centromere, but it has remained unclear whether HJURP has additional functions beyond CENP-A targeting and why high AT DNA content, which disfavors nucleosome assembly, is widely conserved at centromeres. To overcome the difficulties of studying nucleosome formation in vivo, we developed a microscopy assay that enables direct observation of de novo centromeric nucleosome recruitment and maintenance with single molecule resolution.

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Objective: There is an unmet need for optimizing hepatic allograft allocation from nondirected living liver donors (ND-LLD).

Materials And Method: Using OPTN living donor liver transplant (LDLT) data (1/1/2000-12/31/2019), we identified 6328 LDLTs (4621 right, 644 left, 1063 left-lateral grafts). Random forest survival models were constructed to predict 10-year graft survival for each of the 3 graft types.

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Branched chain amino acids (BCAA) supplementation may reduce the incidence of liver failure and hepatocellular carcinoma in patients with cirrhosis. We aimed to determine whether long-term dietary intake of BCAA is associated with liver-related mortality in a well-characterized cohort of North American patients with advanced fibrosis or compensated cirrhosis. We performed a retrospective cohort study using extended follow-up data from the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial.

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Importance: Small waitlist candidates are significantly less likely than larger candidates to receive a liver transplant.

Objective: To investigate the magnitude of the size disparity and test potential policy solutions.

Design, Setting, And Participants: A decision analytical model was generated to match liver transplant donors to waitlist candidates based on predefined body surface area (BSA) ratio limits (donor BSA divided by recipient BSA).

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