Publications by authors named "Sean Richards"

Purpose: To compare clinical outcomes in patients undergoing endoscopic proximal hamstring repair with and without dermal allograft augmentation.

Methods: A retrospective review of prospectively collected data was performed on patients undergoing endoscopic proximal hamstring repair (PHR) and proximal hamstring repair with dermal allograft augmentation (PHR-A) by a single surgeon between 2016 and 2023. Augmentation was utilized for cases of chronic degenerative tears (≥6 weeks from the time of initial injury) where hamstring tissue quality was deemed poor intraoperatively.

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The E3 ubiquitin ligase TRAIP associates with the replisome and helps this molecular machine deal with replication stress. Thus, TRAIP promotes DNA inter-strand crosslink repair by triggering the disassembly of CDC45-MCM2-7-GINS (CMG) helicases that have converged on these lesions. However, disassembly of single CMGs that have stalled temporarily would be deleterious, suggesting that TRAIP must be carefully regulated.

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Purpose: To compare retrospectively the clinical outcomes of patients undergoing endoscopic gluteal tendon repair with and without the use of dermal allograft augmentation.

Methods: A retrospective review of prospectively collected data, single-surgeon cohort study was performed on all patients undergoing endoscopic gluteus medius repair (GMR) and GMR with augmentation (GMR-A) between April 2017 and April 2022. Dermal allograft augmentation was used in cases where intraoperative gluteus tissue quality was poor.

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Medical school clerkship grades are an important method for applicants to distinguish themselves when applying to residency programs. Given the lack of standardization among medical schools in the clerkship grading process, it has become more challenging for orthopaedic surgery residencies to ascertain the true value of surgery clerkship grades between applicants. This letter to the editor is a response to the article by Hoy et al.

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Article Synopsis
  • Decitabine (5-aza-dC) is a nucleoside analogue used for treating certain blood cancers, but its effectiveness can vary and relapses are common.
  • Research using CRISPR/Cas9 screens identified that the loss of the enzyme DCTD makes cancer cells resistant to decitabine by reducing the production of 5-aza-dUMP, which is toxic to cells.
  • The study revealed that the protein TOPORS helps repair decitabine-induced DNA damage and may be targeted for new biomarkers to predict how patients respond to decitabine treatment.
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The catalytic cycle of topoisomerase 2 (TOP2) enzymes proceeds via a transient DNA double-strand break (DSB) intermediate termed the TOP2 cleavage complex (TOP2cc), in which the TOP2 protein is covalently bound to DNA. Anticancer agents such as etoposide operate by stabilizing TOP2ccs, ultimately generating genotoxic TOP2-DNA protein cross-links that require processing and repair. Here, we identify RAD54 like 2 (RAD54L2) as a factor promoting TOP2cc resolution.

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Fetal growth restriction is an obstetrical pathological condition that causes high neonatal mortality and morbidity. The mechanisms of its onset are not completely understood. Metabolites were extracted from 493 placentas from non-complicated pregnancies in Hamilton Country, TN (USA), and analyzed by gas chromatography-mass spectrometry (GC-MS).

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Endometrial cancer (EC) is the most common gynecological neoplasm in high-income countries. Five-year survival rates are related to stage at diagnosis, but currently, no validated screening tests are available in clinical practice. The metabolome offers an unprecedented overview of the molecules underlying EC.

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Background: Historically, noninvasive techniques are only able to identify chromosomal anomalies that accounted for <50% of all congenital defects; the other congenital defects are diagnosed via ultrasound evaluations in the later stages of pregnancy. Metabolomic analysis may provide an important improvement, potentially addressing the need for novel noninvasive and multicomprehensive early prenatal screening tools. A growing body of evidence outlines notable metabolic alterations in different biofluids derived from pregnant women carrying fetuses with malformations, suggesting that such an approach may allow the discovery of biomarkers common to most fetal malformations.

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Article Synopsis
  • Scientists are looking for new ways to help people lose weight because many are affected by obesity, which can lead to serious health problems.
  • A specific genetic variant called Arg95Ter in a gene called GPR151 has been linked to lower body weight and a reduced risk of Type 2 Diabetes in some studies.
  • However, research with a large group of people and experiments on mice show that blocking or changing the GPR151 gene doesn't actually help with weight loss or health issues related to obesity.
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In this review article, we compiled peer-reviewed literature describing PFAS exposure and reproductive effects in animals and humans. The aim was to compare environmental occurrence and effects of the most prominent long-chain PFAS compounds and their short-chain replacements. Long-chain PFAS compounds are known to persist in the environment due to their chemical stability, and also known to bioaccumulate; hence, these compounds are being replaced globally.

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Colorectal cancer (CRC) is a high incidence disease, characterized by high morbidity and mortality rates. Early diagnosis remains challenging because fecal occult blood screening tests have performed sub-optimally, especially due to hemorrhoidal, inflammatory, and vascular diseases, while colonoscopy is invasive and requires a medical setting to be performed. The objective of the present study was to determine if serum metabolomic profiles could be used to develop a novel screening approach for colorectal cancer.

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Chronic kidney disease (CKD) imposes a strong and independent risk for peripheral artery disease (PAD). While solutes retained in CKD patients (uremic solutes) inflict vascular damage, their role in PAD remains elusive. Here, we show that the dietary tryptophan-derived uremic solutes including indoxyl sulfate (IS) and kynurenine (Kyn) at concentrations corresponding to those in CKD patients suppress β-catenin in several cell types, including microvascular endothelial cells (ECs), inhibiting Wnt activity and proangiogenic Wnt targets in ECs.

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Background: CKD, characterized by retained uremic solutes, is a strong and independent risk factor for thrombosis after vascular procedures . Urem ic solutes such as indoxyl sulfate (IS) and kynurenine (Kyn) mediate prothrombotic effect through tissue factor (TF). IS and Kyn biogenesis depends on multiple enzymes, with therapeutic implications unexplored.

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Background: The adoption of biomarkers as part of high-throughput, complex microarray or sequencing data has necessitated the discovery and validation of these data through machine learning. Machine learning has remained a fundamental and indispensable tool due to its efficacy and efficiency in both feature extraction of relevant biomarkers as well as the classification of samples as validation of the discovered biomarkers.

Objectives: This review aims to present the impact and ability of various machine learning methodologies and models to process high-throughput, high-dimensionality data found within mass spectrometry, microarray, and DNA/RNA-sequence data; data that precluded biomarker discovery prior to the use of machine learning.

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Objective: Heart anomalies represent nearly one-third of all congenital anomalies. They are currently diagnosed using ultrasound. However, there is a strong need for a more accurate and less operator-dependent screening method.

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Anthropogenic endocrine-disrupting chemicals (EDCs) can contaminate air, soil, and water. Human exposures to EDCs occur through inhalation, absorption, and ingestion. EDCs act by disrupting various pathways in the endocrine system.

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Colorectal cancer (CRC) is a leading nonfamilial cause of cancer mortality among men and women. Although various genetic and epigenetic mechanisms have been identified, the full molecular mechanisms deriving CRC tumorigenesis are not fully understood. This study demonstrates that cell adhesion molecule transmembrane and immunoglobulin domain containing 1 (TMIGD1) are highly expressed in mouse and human normal intestinal epithelial cells.

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Importance: Endometrial carcinoma (EC) is the most commonly diagnosed gynecologic cancer. Its early detection is advisable because 20% of women have advanced disease at the time of diagnosis.

Objective: To clinically validate a metabolomics-based classification algorithm as a screening test for EC.

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