Publications by authors named "Catherine Welsh"

Somatic mitochondrial DNA (mtDNA) mutations are prevalent in tumors, yet defining their biological significance remains challenging due to the intricate interplay between selective pressure, heteroplasmy, and cell state. Utilizing bulk whole-genome sequencing data from matched tumor and normal samples from two cohorts of pediatric cancer patients, we uncover differences in the accumulation of synonymous and nonsynonymous mtDNA mutations in pediatric leukemias, indicating distinct selective pressures. By integrating single-cell sequencing (SCS) with mathematical modeling and network-based systems biology approaches, we identify a correlation between the extent of cell-state changes associated with tumor-enriched mtDNA mutations and the selective pressures shaping their distribution among individual leukemic cells.

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Background: Adult childhood cancer survivors are at risk for frailty, including low muscle mass and weakness (sarcopenia). Using peripheral blood mitochondrial DNA copy number (mtDNAcn) as a proxy for functional mitochondria, this study describes cross-sectional associations between mtDNAcn and sarcopenia among survivors.

Methods: Among 1762 adult childhood cancer survivors (51.

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Genotyping microarrays are an important resource for genetic mapping, population genetics, and monitoring of the genetic integrity of laboratory stocks. We have developed the third generation of the Mouse Universal Genotyping Array (MUGA) series, GigaMUGA, a 143,259-probe Illumina Infinium II array for the house mouse (Mus musculus). The bulk of the content of GigaMUGA is optimized for genetic mapping in the Collaborative Cross and Diversity Outbred populations, and for substrain-level identification of laboratory mice.

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Complex human traits are influenced by variation in regulatory DNA through mechanisms that are not fully understood. Because regulatory elements are conserved between humans and mice, a thorough annotation of cis regulatory variants in mice could aid in further characterizing these mechanisms. Here we provide a detailed portrait of mouse gene expression across multiple tissues in a three-way diallel.

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The Collaborative Cross (CC) is a panel of recombinant inbred lines derived from eight genetically diverse laboratory inbred strains. Recently, the genetic architecture of the CC population was reported based on the genotype of a single male per line, and other publications reported incompletely inbred CC mice that have been used to map a variety of traits. The three breeding sites, in the US, Israel, and Australia, are actively collaborating to accelerate the inbreeding process through marker-assisted inbreeding and to expedite community access of CC lines deemed to have reached defined thresholds of inbreeding.

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Inbred model organisms are powerful tools for genetic studies because they provide reproducible genomes for use in mapping and genetic manipulation. Generating inbred lines via sibling matings, however, is a costly undertaking that requires many successive generations of breeding, during which time many lines fail. We evaluated several approaches for accelerating inbreeding, including the systematic use of back-crosses and marker-assisted breeder selection, which we contrasted with randomized sib-matings.

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The JAX Diversity Outbred population is a new mouse resource derived from partially inbred Collaborative Cross strains and maintained by randomized outcrossing. As such, it segregates the same allelic variants as the Collaborative Cross but embeds these in a distinct population architecture in which each animal has a high degree of heterozygosity and carries a unique combination of alleles. Phenotypic diversity is striking and often divergent from phenotypes seen in the founder strains of the Collaborative Cross.

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Because bundle implementation in intensive care units to reduce methicillin-resistant Staphylococcus aureus is challenging, we conducted in-depth interviews with implementation teams at 5 participating hospitals. Key lessons learned across hospitals included the following: maintain management support, engage frontline staff, build the right multidisciplinary team, conduct process mapping, and commit to data collection and feedback.

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Background: Health care-associated infections (HAIs) are a leading cause of death in United States health care settings, with an overall estimated annual incidence of 1.7 million. As antimicrobial resistance has increased, so too have efforts to reduce HAI rates.

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There has been increasing interest and an upsurge in efforts to prevent hospital-associated infections (HAIs), a leading cause of death in the United States. This study was conducted to assess current strategies and efforts of HAI reduction initiatives in hospitals. HAI reduction initiatives and factors influencing institutional participation in these initiatives were categorized.

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Article Synopsis
  • The study presents a detailed genetic map tracing the ancestry of most current laboratory mouse strains, showing they mainly descend from a few "fancy" mice with limited genetic variety.
  • It finds that these classical strains are predominantly of Mus musculus domesticus origin, with some influence from Japanese mice, highlighting their constrained genetic diversity.
  • In contrast, wild-derived laboratory strains showcase a wider genetic diversity and show evidence of interbreeding with other subspecies, influenced by contamination from existing lab stocks.
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In order to examine the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-P) in combination with bevacizumab (B) and gemcitabine (G) for the first-line treatment of patients with HER2-negative metastatic breast cancer (MBC). In this single-center, open-label phase II trial, patients with HER2-negative MBC received gemcitabine 1500 mg/m(2), nab-paclitaxel 150 mg/m(2), and bevacizumab 10 mg/kg (each administered intravenously) on days 1 and 15 of a 28-day cycle. The primary end point was progression free survival (PFS); secondary end points were overall response rate (ORR), complete (CR) and partial (PR) response rates, clinical benefit (ORR + stable disease), overall survival (OS), and safety.

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During a handoff, communication errors can lead to adverse events and suboptimal patient care. As a result, many institutions want to redesign their handoff processes, but have little specific guidance from the literature. We examined two approaches to nursing end-of-shift reports both taped and written, to identify specific factors limiting and facilitating such handoffs.

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Background: Successful therapeutic regimens in metastatic breast cancer (MBC) must balance efficacy and tolerability. Docetaxel/capecitabine is an active and commonly used doublet in this setting. Docetaxel upregulates thymidine phosphorylase and thus potentiates the antitumor effects of capecitabine.

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Laser-capture microdissection techniques have enhanced the ability to perform molecular studies of pure-cell populations. Although many technical factors affect the outcome of the procedure, none is more critical than the appropriate handling of the tissue. Because extraction of intact RNA from paraffin-embedded tissue is a difficult and inconsistent process, frozen sections with their attendant problems are used for this purpose.

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To evaluate the effectiveness and safety of weekly docetaxel/carboplatin as primary systemic therapy (PST) for locally advanced breast cancer, we conducted a phase II study. Forty-four patients with HER2-negative locally advanced or inflammatory breast cancer (IBC) received docetaxel 35 mg/m(2) and carboplatin to an area under the curve of 2 mg/mL/min for 3 of 4 weeks over 16 weeks. After completion of PST, patients had breast surgery and then received 4 cycles of adjuvant cyclophosphamide/doxorubicin, standard radiation therapy, and, for hormone receptorpositive tumors, tamoxifen.

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Abnormally suppressed levels of cyclin-dependent kinase inhibitors (CKIs) are associated with aggressive androgen-independent prostate cancer and contribute to uncontrolled proliferation. The androgen-independent human prostate cancer cell lines, LNCaP-104R1, ALVA31 and PC-3, express low levels of the CKI, p21(CIP1), compared to the less-malignant, androgen-dependent LNCaP cells. We investigated the mechanism underlying this suppression by examining the role of Rho GTPases, signaling proteins that play important roles in cell cycle progression, at least in part through regulation of CKIs.

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Mitogenic growth factor- and integrin-dependent signaling pathways cooperate to control the proliferation of nontransformed cells. As integral mediators of these networks, the Rho family of GTPases play a pivotal role in G1 cell cycle progression, primarily through regulation of cyclin D1 expression, as well as the levels of the cyclin-dependent kinase inhibitors p21cip1 and p27kip1. Such dual control of both the critical positive and negative regulators of G1 progression make the Rho GTPases prime candidates to target the autonomous proliferation which typifies cancer cells.

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