Publications by authors named "Clemens D"

The development of pancreatic cancer requires both, acquisition of an oncogenic mutation in KRAS as well as an inflammatory insult. However, the physiological causes for pancreatic inflammation are less defined. We show here that oncogenic KRas-expressing pre-neoplastic lesion cells upregulate coxsackievirus (CVB) and adenovirus receptor (CAR).

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The elderly population is highly susceptible to developing respiratory diseases, including tuberculosis, a devastating disease caused by the airborne pathogen Mycobacterium tuberculosis (M.tb) that kills one person every 18 seconds. Once M.

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The removal of the toxic oxidized cholesterol, 7-ketocholesterol (7KC), from cells through the administration of therapeutics has the potential to treat atherosclerosis and various other pathologies. While cholesterol is a necessary building block for homeostasis, oxidation of cholesterol can lead to the formation of toxic oxysterols involved in various pathologies, the most prominent of which is 7KC, which is formed through the non-enzymatic oxidation of cholesterol. Oxidized LDL (oxLDL) particles, highly implicated in heart disease, contain high levels of 7KC, and molecular 7KC is implicated in the pathogenesis of numerous diseases, including multiple sclerosis, hypercholesterolemia, sickle cell anemia, and multiple age related diseases.

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A class of cyclodextrin (CD) dimers has emerged as a potential new treatment for atherosclerosis; they work by forming strong, soluble inclusion complexes with oxysterols, allowing the body to reduce and heal arterial plaques. However, characterizing the interactions between CD dimers and oxysterols presents formidable challenges due to low sterol solubility, the synthesis of modified CDs resulting in varying number and position of molecular substitutions, and the diversity of interaction mechanisms. To address these challenges and illuminate the nuances of CD-sterol interactions, we have used multiple orthogonal approaches for a comprehensive characterization.

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Triadin knockout syndrome (TKOS) is a malignant arrhythmia disorder caused by recessive null variants in TRDN-encoded cardiac triadin. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) were generated from two unrelated TKOS patients and an unrelated control. CRISPR-Cas9 gene editing was used to insert homozygous TRDN-p.

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Article Synopsis
  • - The study investigates the effects of direct SARS-CoV-2 infection on heart cells, specifically human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), to understand how the virus contributes to cardiac issues like arrhythmias and sudden cardiac death.
  • - Researchers found that exposing hiPSC-CMs to the SARS-CoV-2 spike protein results in the formation of larger multinucleated cells, prolonged action potential duration, and abnormal calcium handling, which can lead to increased risks of heart arrhythmias.
  • - Treatment with a furin protease inhibitor or mutations to the spike protein reversed these cellular disruptions, suggesting that targeting the spike protein may help mitigate cardiac risks associated with COVID-19.
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In preclinical studies, a new antituberculosis drug regimen markedly reduced the time required to achieve relapse-free cure. This study aimed to preliminarily evaluate the efficacy and safety of this four-month regimen, consisting of clofazimine, prothionamide, pyrazinamide and ethambutol, with a standard six-month regimen in patients with drug-susceptible tuberculosis. An open-label pilot randomized clinical trial was conducted among the patients with newly diagnosed bacteriologically-confirmed pulmonary tuberculosis.

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Background & Aims: Src homology and collagen (Shc) proteins are major adapters to extracellular signals, however, the regulatory role of Shc isoforms in sterile inflammatory responses in alcoholic hepatitis (AH) has not been fully investigated. We hypothesized that in an isoform-specific manner Shc modulates pre-apoptotic signals, calreticulin (CRT) membrane exposure, and recruitment of inflammatory cells.

Methods: Liver biopsy samples from patients with AH vs healthy subjects were studied for Shc expression using DNA microarray data and immunohistochemistry.

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Francisella tularensis, a Tier 1 select agent of bioterrorism, contains a type VI secretion system (T6SS) encoded within the pathogenicity island (FPI), which is critical for its pathogenesis. Among the 18 proteins encoded by FPI is IglD, which is essential to 's intracellular growth and virulence, but neither its location within T6SS nor its functional role has been established. Here, we present the cryoEM structure of IglD from Francisella novicida and show that the IglD forms a homotrimer that is structurally homologous to the T6SS baseplate protein TssK in Escherichia coli.

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Direct back-face transmission steady-state fluorescence was successfully applied to the study of aggregation of ibuprofen and ibuprofenate anion in solution taking advantage of its own fluorescence. The analysis of the experimental data involves the use of the differential reabsorption model to account for re-absorption phenomenon and the closed association model to describe aggregation. The fluorescence quantum yield of ibuprofenate increases when it aggregates in the presence of sodium, but it markedly decreases when 1-butyl-3-methylimidazolium is used as counterion.

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Interactions of polyelectrolytes with oppositely charged surfactants can give rise to a large variety of self-assembled structures. Some of these systems cause a drastic increase in solution viscosity, which is related to the surfactant forming aggregates interconnecting several polyelectrolyte chains. For these aggregates to form, the surfactant needs to be sufficiently hydrophobic.

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Chronic inflammation plays a critical role in the pathogenesis of atherosclerosis. Currently, the mechanism(s) by which inflammation contributes to this disease are not entirely understood. Inflammation is known to induce oxidative stress, which can lead to lipid peroxidation.

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Article Synopsis
  • Tetracaine (TTC) is a widely used local anesthetic, but it has systemic toxicity, which can be reduced by using nanostructured lipid carriers (NLC) to prolong its delivery at injection sites.
  • The study involved developing NLC with 4% TTC, using experimental designs to assess structural properties and encapsulation efficiency (over 63%), and various analyses indicated the nanoparticles' average sizes, stability, and shape.
  • One optimized formulation displayed phase separation over time, and further analyses revealed the nanoparticles' lamellar structures; the selected formulations significantly extended anesthetic release beyond 48 hours while decreasing cytotoxicity to cells.
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Outpatient parenteral antibiotic therapy (OPAT) refers to the monitored provision of intravenous antibiotics for complicated infections outside of a hospital setting, typically in a rehabilitation facility, an infusion center, or the home. Home-based OPAT allows for safe completion of prolonged courses of therapy while decreasing costs to the healthcare system, minimizing the risk of hospital-related infectious exposures for patients, and permitting patients to recover in a familiar environment. Amidst the COVID-19 pandemic, during which nursing facilities have been at the center of many outbreaks of the SARS-CoV-2 virus, completion of antimicrobial therapy in the home is an even more appealing option.

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Article Synopsis
  • * The review highlights the potential for recovery after stopping alcohol intake, emphasizing that the liver can regenerate significantly even after years of heavy use.
  • * It discusses how different organs process alcohol, the extent of damage they incur, and their ability to recover during periods of abstinence, citing studies on both humans and animal models.
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We have developed a novel class of specifically engineered, dimerized cyclodextrin (CD) nanostructures for the encapsulation of toxic biomolecules such as 7-ketocholesterol (7KC). 7KC accumulates over time and causes dysfunction in many cell types, linking it to several age-related diseases including atherosclerosis and age-related macular degeneration (AMD). Presently, treatments for these diseases are invasive, expensive, and show limited benefits.

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Background: Triadin knockout syndrome (TKOS) is a rare arrhythmia syndrome caused by recessive null variants in TRDN-encoded cardiac triadin 1. TKOS has presented frequently with cardiac arrest in childhood.

Objective: The purpose of this study was to elucidate the underlying genetic mechanism of disease in a genetically elusive patient displaying a characteristic TKOS phenotype.

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Introduction: High incidence of bleeding events remains a key risk for patients taking anticoagulants, especially those in need of long-term combination therapy with antiplatelet agents. As a consequence, patients may not receive clinically indicated combination antithrombotic therapy. Here, we report on VE-1902, a member of a novel class of precision oral anticoagulants (PROACs) that combines effective anticoagulation with reduced bleeding in preclinical testing.

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Background: Non-alcoholic fatty liver disease (NAFLD) is a common cause of liver disease worldwide and is a growing epidemic. A high ratio of omega-6 fatty acids to omega-3 fatty acids in the diet has been implicated in the development of NAFLD. However, the inflicted cellular pathology remains unknown.

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Background: Triadin knockout syndrome (TKOS) is a potentially lethal arrhythmia disorder caused by recessively inherited null variants in -encoded cardiac triadin. Despite its malignant phenotype, the prevalence of TKOS in sudden infant death syndrome and sudden unexplained death in the young is unknown.

Methods: Exome sequencing was performed on 599 sudden infant death syndrome and 258 sudden unexplained death in the young cases.

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This study is dedicated to link the nanoscale pore space of carbon materials, prepared by hard-templating of meso-macroporous SiO monoliths, to the corresponding nanoscale polyaromatic microstructure using two different carbon precursors wthat generally exhibit markedly different carbonization properties, i.e., a graphitizable pitch and a non-graphitizable resin.

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The functional maturation status of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) has a notable impact upon their use in pharmacological studies, disease modeling, and therapeutic applications. Non-cardiomyocytes (non-CMs) produced in the differentiation process have previously been identified as having an extrinsic influence upon hiPSC-CM development, yet the underlying mechanisms are not fully understood. Herein, we aimed to modulate electrophysiological properties of hiPSC-CMs within co-cultures containing varied proportions of non-CMs and investigate the nature of interactions between these different cell types.

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Francisella bacteria rely on a phylogenetically distinct type VI secretion system (T6SS) to escape host phagosomes and cause the fatal disease tularemia, but the structural and molecular mechanisms involved are unknown. Here we report the atomic structure of the Francisella T6SS central spike complex, obtained by cryo-electron microscopy. Our structural and functional studies demonstrate that, unlike the single-protein spike composition of other T6SS subtypes, Francisella T6SS's central spike is formed by two proteins, PdpA and VgrG, akin to T4-bacteriophage gp27 and gp5, respectively, and that PdpA has unique characteristics, including a putative cargo within its cavity and an N-terminal helical lid.

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