Pathway to cardiothoracic surgery: A primer for aspiring students.

Objective: The pathway to cardiothoracic surgery is often obscure for premedical students and aspiring applicants and requires navigating various known and unknown obstacles. Recognizing the challenges encountered on the path to a career in cardiothoracic surgery in the United States, we present this guide for students interested in the field to maximize success in their premedical, preclinical, and preresidency years.

Methods: This is a joint collaboration between the Thoracic Surgery Residents Association and the Thoracic Surgery Medical Student Association.

Tubular CPT1A deletion minimally affects aging and chronic kidney injury.

Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction.

Peroxidasin is required for full viability in development and for maintenance of tissue mechanics in adults.

Basement membranes are thin strong sheets of extracellular matrix. They provide mechanical and biochemical support to epithelia, muscles, nerves, and blood vessels, among other tissues. The mechanical properties of basement membranes are conferred in part by Collagen IV (Col4), an abundant protein of basement membranes that forms an extensive two-dimensional network through head-to-head and tail-to-tail interactions.

Mechanism of peroxidasin inactivation in hyperglycemia: Heme damage by reactive oxygen species.

Diabetic complications present a serious health problem. Functional damage to proteins due to post-translational modifications by glycoxidation reactions is a known factor contributing to pathology. Extracellular proteins are especially vulnerable to diabetic damage because robust antioxidant defenses are lacking outside the cell.

Identification of brominated proteins in renal extracellular matrix: Potential interactions with peroxidasin.

Peroxidasin (PXDN) is an extracellular peroxidase, which generates hypobromous acid to form sulfilimine cross-links within collagen IV networks. We have previously demonstrated that mouse and human renal basement membranes (BM) are enriched in bromine due to PXDN-dependent post-translational bromination of protein tyrosine residues. The goal of the present study was identification of specific brominated sites within renal BM.

Analysis of and mouse mutants reveals that Peroxidasin is required for tissue mechanics and full viability.

Basement membranes are thin strong sheets of extracellular matrix. They provide mechanical and biochemical support to epithelia, muscles, nerves, and blood vessels, among other tissues. The mechanical properties of basement membranes are conferred in part by Collagen IV (Col4), an abundant protein of basement membrane that forms an extensive two-dimensional network through head-to-head and tail-to-tail interactions.

Secondary Structure of DNA Aptamer Influences Biomimetic Mineralization of Calcium Carbonate.

Calcium materials, such as calcium carbonate, are produced in natural and industrial settings that range from oceanic to biomedical. An array of biological and biomimetic template molecules have been employed in controlling and understanding the mineralization reaction but have largely focused on small molecule additives or disordered polyelectrolytes. DNA aptamers are synthetic and programmable biomolecules with polyelectrolyte characteristics but with predictable and controllable secondary structure akin to native extracellular moieties.

Peroxidasin Deficiency Re-programs Macrophages Toward Pro-fibrolysis Function and Promotes Collagen Resolution in Liver.

Background & Aims: During liver fibrosis, tissue repair mechanisms replace necrotic tissue with highly stabilized extracellular matrix proteins. Extracellular matrix stabilization influences the speed of tissue recovery. Here, we studied the expression and function of peroxidasin (PXDN), a peroxidase that uses hydrogen peroxide to cross-link collagen IV during liver fibrosis progression and regression.

Charting the sequence-activity landscape of peptide inhibitors of translation termination.

Apidaecin (Api), an unmodified 18-amino-acid-long proline-rich antibacterial peptide produced by bees, has been recently described as a specific inhibitor of translation termination. It invades the nascent peptide exit tunnel of the postrelease ribosome and traps the release factors preventing their recycling. Api binds in the exit tunnel in an extended conformation that matches the placement of a nascent polypeptide and establishes multiple contacts with ribosomal RNA (rRNA) and ribosomal proteins.

Peroxidasin-mediated bromine enrichment of basement membranes.

Bromine and peroxidasin (an extracellular peroxidase) are essential for generating sulfilimine cross-links between a methionine and a hydroxylysine within collagen IV, a basement membrane protein. The sulfilimine cross-links increase the structural integrity of basement membranes. The formation of sulfilimine cross-links depends on the ability of peroxidasin to use bromide and hydrogen peroxide substrates to produce hypobromous acid (HOBr).

Selected DNA aptamers as hydroxyapatite affinity reagents.

DNA aptamers were selected for their ability to bind specifically and quickly to crystalline hydroxyapatite (Ca(PO)(OH); HAP), the primary mineral component of enamel and bone. Aptamers were found to have an enhanced percent of G-nucleotides and a propensity for forming a G-quadruplex secondary structure. One aptamer was studied in comparison to control sequences and was found to bind with high affinity and at high loading capacity, with enhanced binding kinetics, and with specificity for crystalline HAP material over amorphous calcium phosphate (ACP) and β-tricalcium phosphate (TCP).

Peroxidasin and eosinophil peroxidase, but not myeloperoxidase, contribute to renal fibrosis in the murine unilateral ureteral obstruction model.

Renal fibrosis is the pathological hallmark of chronic kidney disease (CKD) and manifests as glomerulosclerosis and tubulointerstitial fibrosis. Reactive oxygen species contribute significantly to renal inflammation and fibrosis, but most research has focused on superoxide and hydrogen peroxide (HO). The animal heme peroxidases myeloperoxidase (MPO), eosinophil peroxidase (EPX), and peroxidasin (PXDN) uniquely metabolize HO into highly reactive and destructive hypohalous acids, such as hypobromous and hypochlorous acid.

Evaluating the relationship between gait and clinical measures of plantar flexor function.

Individuals with plantar flexor weakness often require rehabilitation and/or orthoses, which should be personalized based on level of weakness. While plantar flexor weakness can be measured via peak plantar flexion moment during gait (M), motion analysis systems are often not clinically available. Clinical measures, such as the single-leg heel rise (SLHR) test and isometric muscle test, may provide surrogate measures of plantar flexor function during gait.

A Comprehensive Method to Measure 3-Dimensional Bra Motion During Physical Activity.

Breast and bra motion research aims to understand how the breasts/bra move to aid development of apparel that minimizes motion. Most previously published research has tracked nipple motion to represent bra motion. However, this method does not provide information regarding regional tissue motion.

Role of Hypohalous Acids in Basement Membrane Homeostasis.

Significance: Basement membranes (BMs) are sheet-like structures of specialized extracellular matrix that underlie nearly all tissue cell layers including epithelial, endothelial, and muscle cells. BMs not only provide structural support but are also critical for the development, maintenance, and repair of organs. Animal heme peroxidases generate highly reactive hypohalous acids extracellularly and, therefore, target BMs for oxidative modification.

The sulfilimine cross-link of collagen IV contributes to kidney tubular basement membrane stiffness.

Basement membranes (BMs), a specialized form of extracellular matrix, underlie nearly all cell layers and provide structural support for tissues and interact with cell surface receptors to determine cell behavior. Both macromolecular composition and stiffness of the BM influence cell-BM interactions. Collagen IV is a major constituent of the BM that forms an extensively cross-linked oligomeric network.

Prediction of Relapse After Discontinuation of Antipsychotic Treatment in Alzheimer's Disease: The Role of Hallucinations.

Objective: In Alzheimer's disease, antipsychotic medications are often used for a period, with relief of symptoms, and then discontinued, after which relapse may occur. The authors sought to determine which neuropsychiatric symptoms predict relapse.

Method: In the Antipsychotic Discontinuation in Alzheimer's Disease trial, 180 patients with Alzheimer's disease and symptoms of agitation or psychosis were treated with risperidone for 16 weeks, after which patients who responded (N=110) were randomly assigned to continue risperidone for 32 weeks, to continue risperidone for 16 weeks followed by switch to placebo for 16 weeks, or to receive placebo for 32 weeks.

Proprotein Convertase Processing Enhances Peroxidasin Activity to Reinforce Collagen IV.

The basement membrane (BM) is a form of extracellular matrix that underlies cell layers in nearly all animal tissues. Type IV collagen, a major constituent of BMs, is critical for tissue development and architecture. The enzyme peroxidasin (Pxdn), an extracellular matrix-associated protein, catalyzes the formation of structurally reinforcing sulfilimine cross-links within the collagen IV network, an event essential to basement membrane integrity.

Cranial nerve injury is associated with dual antiplatelet therapy use and cervical hematoma after carotid endarterectomy.

Objective: To determine predictors of cranial nerve injury (CNI) after carotid endarterectomy (CEA).

Methods: Consecutive CEAs performed over a 5-year period were enrolled in this study. Outcomes analyzed included 30-day major adverse event rate (composite of stroke, death, and myocardial infarction), death, stroke, disabling stroke, myocardial infarction, cervical hematoma and CNI rate, reoperation, and hospital readmission at 30 days.

Extracellular chloride signals collagen IV network assembly during basement membrane formation.

Basement membranes are defining features of the cellular microenvironment; however, little is known regarding their assembly outside cells. We report that extracellular Cl(-) ions signal the assembly of collagen IV networks outside cells by triggering a conformational switch within collagen IV noncollagenous 1 (NC1) domains. Depletion of Cl(-) in cell culture perturbed collagen IV networks, disrupted matrix architecture, and repositioned basement membrane proteins.

Genome-wide association interaction analysis for Alzheimer's disease.

We propose a minimal protocol for exhaustive genome-wide association interaction analysis that involves screening for epistasis over large-scale genomic data combining strengths of different methods and statistical tools. The different steps of this protocol are illustrated on a real-life data application for Alzheimer's disease (AD) (2259 patients and 6017 controls from France). Particularly, in the exhaustive genome-wide epistasis screening we identified AD-associated interacting SNPs-pair from chromosome 6q11.