A Needs Assessment for Infectious Diseases Consultation in Community Hospitals.

INTRODUCTION: Infectious diseases (ID) consultations have been demonstrated to improve patient outcomes in the treatment of severe infections. However, ID consultation is often unavailable to patients that live in rural communities. Little is known regarding the treatment of infections in rural hospitals with no coverage from an ID specialist. We characterized the outcomes of patients cared for in hospitals without coverage from an ID physician. METHODS: Patients aged 18 years or older admitted to eight community hospitals without access to ID consultation during a 6.5-month period were assessed. All patients had received at least three days of continuous antimicrobial therapy. The primary outcome was the need for transfer to a tertiary facility for ID services. The secondary outcome was the characterization of antimicrobials received. Antimicrobial courses were evaluated independently by two board-certified ID physicians. RESULTS: 3706 encounters were evaluated. Transfers for ID consultation occurred in 0.01% of patients. The ID physician would have made modifications in 68.5% of patients. Areas for improvement included treatment of chronic obstructive pulmonary disease exacerbations, broad-spectrum treatment of skin and soft tissue infection, long courses of azithromycin, and management of Staphylococcus aureus bacteremia, including choice and length of therapy, as well as obtaining echocardiography. Patients evaluated received 22,807 days of antimicrobial therapy. CONCLUSIONS: Patients hospitalized in community hospitals are rarely transferred for ID consultation. Our work demonstrates a need for ID consultation in community hospitals, identifying opportunities to enhance patient care by modifying antimicrobial regimens to improve antimicrobial stewardship and avoid inappropriate antimicrobials. Efforts to expand the ID workforce to include coverage at rural hospitals will likely improve antibiotic utilization.

Cardiac Magnetic Resonance Imaging for the Diagnosis of Infective Endocarditis in the COVID-19 Era.

In the COVID-19 pandemic, to minimize aerosol-generating procedures, cardiac magnetic resonance imaging (CMR) was utilized at our institution as an alternative to transesophageal echocardiography (TEE) for diagnosing infective endocarditis (IE). This retrospective study evaluated the clinical utility of CMR for detecting IE among 14 patients growing typical microorganisms on blood cultures or meeting modified Duke Criteria. Seven cases were treated for IE. In 2 cases, CMR results were notable for possible leaflet vegetations and were clinically meaningful in guiding antibiotic therapy, obtaining further imaging, and/or pursuing surgical intervention. In 2 cases, vegetations were missed on CMR but detected on TEE. In 3 cases, CMR was non-diagnostic, but patients were treated empirically. There was no difference in antibiotic duration or outcomes over 1 year. CMR demonstrated mixed results in diagnosing valvular vegetations and guiding clinical decision-making. Further prospective controlled trials of CMR Vs TEE are warranted.

Chronic Diclofenac Exposure Increases Mitochondrial Oxidative Stress, Inflammatory Mediators, and Cardiac Dysfunction.

PURPOSE: Nonsteroidal anti-inflammatory drugs (NSAIDs) are among one of the most commonly prescribed medications for pain and inflammation. Diclofenac (DIC) is a commonly prescribed NSAID that is known to increase the risk of cardiovascular diseases. However, the mechanisms underlying its cardiotoxic effects remain largely unknown. In this study, we tested the hypothesis that chronic exposure to DIC increases oxidative stress, which ultimately impairs cardiovascular function. METHODS AND RESULTS: Mice were treated with DIC for 4 weeks and subsequently subjected to in vivo and in vitro functional assessments. Chronic DIC exposure resulted in not only systolic but also diastolic dysfunction. DIC treatment, however, did not alter blood pressure or electrocardiographic recordings. Importantly, treatment with DIC significantly increased inflammatory cytokines and chemokines as well as cardiac fibroblast activation and proliferation. There was increased reactive oxygen species (ROS) production in cardiomyocytes from DIC-treated mice, which may contribute to the more depolarized mitochondrial membrane potential and reduced energy production, leading to a significant decrease in sarcoplasmic reticulum (SR) Ca2+ load, Ca2+ transients, and sarcomere shortening. Using unbiased metabolomic analyses, we demonstrated significant alterations in oxylipin profiles towards inflammatory features in chronic DIC treatment. CONCLUSIONS: Together, chronic treatment with DIC resulted in severe cardiotoxicity, which was mediated, in part, by an increase in mitochondrial oxidative stress.

Serratia Marcescens, a Rare and Devastating Cause of Endocarditis: A Case Report and Review of the Literature.

Serratia marcescens is a gram-negative bacillus that is an opportunistic agent in respiratory tract infections, urinary tract infections, and septicemia. It is rarely a cause of infective endocarditis, but in cases of endocarditis, it follows a rapid and devastating course. A previously healthy female in her mid-50s presented with fever, abdominal pain, right lower extremity pain, and diarrhea. Blood cultures were positive for S. marcescens , and additional evaluation revealed infarction in the spleen and kidneys, raising concern for endocarditis with associated embolic phenomena. The patient was subsequently found to have an embolus in the right popliteal artery and underwent a right popliteal thromboembolectomy. Antimicrobial therapy with cefepime and gentamicin was begun. A transesophageal echocardiogram revealed a large, mobile mitral valve vegetation. Care was complicated by intracranial hemorrhage, and the decision was made to withdraw care. A review of the databases Embase and PubMed revealed 63 additional cases of S. marcescens endocarditis. Analysis of these cases demonstrated a preponderance of aortic and mitral valve involvement, not tricuspid valve involvement, despite a risk factor of intravenous drug use in over 60% of cases. Mortality was 50%, and sequelae such as congestive heart failure and renal insufficiency occurred in the majority of survivors. In conclusion, S. marcescens is a rare but devastating cause of endocarditis with a primary risk factor of intravenous drug use but with a predilection for left-sided valvular lesions, not right-sided lesions.

Exploring time-resolved photoluminescence for nanowires using a three-dimensional computational transient model.

Time-resolved photoluminescence (TRPL) has been implemented experimentally to measure the carrier lifetime of semiconductors for decades. For the characterization of nanowires, the rich information embedded in TRPL curves has not been fully interpreted and meaningfully mapped to the respective material properties. This is because their three-dimensional (3-D) geometries result in more complicated mechanisms of carrier recombination than those in thin films and analytical solutions cannot be found for those nanostructures. In this work, we extend the intrinsic power of TRPL by developing a full 3-D transient model, which accounts for different material properties and drift-diffusion, to simulate TRPL curves for nanowires. To show the capability of the model, we perform TRPL measurements on a set of GaAs nanowire arrays grown on silicon substrates and then fit the measured data by tuning various material properties, including carrier mobility, Shockley-Read-Hall recombination lifetime, and surface recombination velocity at the GaAs-Si heterointerface. From the resultant TRPL simulations, we numerically identify the lifetime characteristics of those material properties. In addition, we computationally map the spatial and temporal electron distributions in nanowire segments and reveal the underlying carrier dynamics. We believe this study provides a theoretical foundation for interpretation of TRPL measurements to unveil the complex carrier recombination mechanisms in 3-D nanostructured materials.

Electrotaxis of cardiac progenitor cells, cardiac fibroblasts, and induced pluripotent stem cell-derived cardiac progenitor cells requires serum and is directed via PI3'K pathways.

BACKGROUND: The limited regenerative capacity of cardiac tissue has long been an obstacle to treating damaged myocardium. Cell-based therapy offers an enormous potential to the current treatment paradigms. However, the efficacy of regenerative therapies remains limited by inefficient delivery and engraftment. Electrotaxis (electrically guided cell movement) has been clinically used to improve recovery in a number of tissues but has not been investigated for treating myocardial damage. OBJECTIVE: The purpose of this study was to test the electrotactic behaviors of several types of cardiac cells. METHODS: Cardiac progenitor cells (CPCs), cardiac fibroblasts (CFs), and human induced pluripotent stem cell-derived cardiac progenitor cells (hiPSC-CPCs) were used. RESULTS: CPCs and CFs electrotax toward the anode of a direct current electric field, whereas hiPSC-CPCs electrotax toward the cathode. The voltage-dependent electrotaxis of CPCs and CFs requires the presence of serum in the media. Addition of soluble vascular cell adhesion molecule to serum-free media restores directed migration. We provide evidence that CPC and CF electrotaxis is mediated through phosphatidylinositide 3-kinase signaling. In addition, very late antigen-4, an integrin and growth factor receptor, is required for electrotaxis and localizes to the anodal edge of CPCs in response to direct current electric field. The hiPSC-derived CPCs do not express very late antigen-4, migrate toward the cathode in a voltage-dependent manner, and, similar to CPCs and CFs, require media serum and phosphatidylinositide 3-kinase activity for electrotaxis. CONCLUSION: The electrotactic behaviors of these therapeutic cardiac cells may be used to improve cell-based therapy for recovering function in damaged myocardium.

Management and Restoration of an Implant With Irreversibly Damaged Internal Threads: A Clinical Report.

This report describes a method to restore an implant with irreversibly damaged internal threads. The remaining fractured post from the previous restoration was removed using a combination of an impression coping and an end-cutting bur. An elastomeric impression of the internal surface of the damaged implant, as well as the position of the adjacent implant, was made for fabrication of a new cast post and core and an implant supported 2-unit ceramometal splinted prosthesis.

High-Quality InAsSb Nanowires Grown by Catalyst-Free Selective-Area Metal-Organic Chemical Vapor Deposition.

We report on the first demonstration of InAs1-xSbx nanowires grown by catalyst-free selective-area metal-organic chemical vapor deposition (SA-MOCVD). Antimony composition as high as 15 % is achieved, with strong photoluminescence at all compositions. The quality of the material is assessed by comparing the photoluminescence (PL) peak full-width at half-max (fwhm) of the nanowires to that of epitaxially grown InAsSb thin films on InAs. We find that the fwhm of the nanowires is only a few meV broader than epitaxial films, and a similar trend of relatively constant fwhm for increasing antimony composition is observed. Furthermore, the PL peak energy shows a strong dependence on temperature, suggesting wave-vector conserving transitions are responsible for the observed PL in spite of lattice mismatched growth on InAs substrate. This study shows that high-quality InAsSb nanowires can be grown by SA-MOCVD on lattice mismatched substrate, resulting in material suitable for infrared detectors and high-performance nanoelectronic devices.

Axial diffusion barriers in near-infrared nanopillar LEDs.

The growth of GaAs/GaAsP axial heterostructures is demonstrated and implemented as diffusion current barriers in nanopillar light-emitting diodes at near-infrared wavelengths. The nanopillar light-emitting diodes utilize an n-GaAs/i-InGaAs/p-GaAs axial heterostructure for current injection. Axial GaAsP segments are inserted into the n- and p-GaAs portions of the nanopillars surrounding the InGaAs emitter region, acting as diffusion barriers to provide enhanced carrier confinement. Detailed characterization of growth of the GaAsP inserts and electronic band-offset measurements are used to effectively implement the GaAsP inserts as diffusion barriers. The implementation of these barriers in nanopillar light-emitting diodes provides a 5-fold increase in output intensity, making this a promising approach to high-efficiency pillar-based emitters in the near-infrared wavelength range.