Color Doppler Visualization of Intramyocardial Coronary Arteries Using a New Echo System: Effect of Contrast Enhancement and Vasodilation

Utilizing a new echocardiographic system, intramyocardial coronary arteries could be demonstrated by color Doppler in a small number of open chest animals. Both intravenous and intracoronary injections of a contrast agent (Levovist) resulted in significant enhancement of color flow signals with an increase in the length, width, and the number of these vessels. Similar results were obtained with intravenous infusion and direct intracoronary injections of a vasodilator (adenosine).     

High-dose rifampin improves bactericidal activity without increased intracerebral inflammation in animal models of tuberculous meningitis

Tuberculous meningitis (TB meningitis) is the most severe form of tuberculosis (TB), requiring 12 months of multidrug treatment for cure, and is associated with high morbidity and mortality. High-dose rifampin (35 mg/kg/d) is safe and improves the bactericidal activity of the standard-dose (10 mg/kg/d) rifampin-containing TB regimen in pulmonary TB. However, there are conflicting clinical data regarding its benefit for TB meningitis, where outcomes may also be associated with intracerebral inflammation. We conducted cross-species studies in mice and rabbits, demonstrating that an intensified high-dose rifampin-containing regimen has significantly improved bactericidal activity for TB meningitis over the first-line, standard-dose rifampin regimen, without an increase in intracerebral inflammation. Positron emission tomography in live animals demonstrated spatially compartmentalized, lesion-specific pathology, with postmortem analyses showing discordant brain tissue and cerebrospinal fluid rifampin levels and inflammatory markers. Longitudinal multimodal imaging in the same cohort of animals during TB treatment as well as imaging studies in two cohorts of TB patients demonstrated that spatiotemporal changes in localized blood-brain barrier disruption in TB meningitis are an important driver of rifampin brain exposure. These data provide unique insights into the mechanisms underlying high-dose rifampin in TB meningitis with important implications for developing new antibiotic treatments for infections.     

An Unusual Congenital Heart Disease: Giant Left Atrial Appendage

A 52-year-old female was admitted to our hospital in April 2021 with dyspnea. She was discharged from the hospital 3 weeks ago due to the diagnosis of pneumonia caused by coronavirus disease 2019 (COVID-19). Physical examination revealed an oxygen desaturation of 82%. The patient underwent computed tomography angiography (CTA) that showed a ground-glass pattern and a giant left atrial appendage (Figure 1A). Film array respiratory panel was negative, and pulmonary aspergillosis was diagnosed after bronchoscopy. Cardiac magnetic resonance corroborated the huge left atrial appendage (Figure 1B). No other structural or functional heart abnormalities were diagnosed.Open in a separate windowFigure 1(A) Computed tomography angiography showed a ground-glass opacity and a giant left atrial appendage (red asterisk). (B) Cardiac magnetic resonance confirmed the huge left atrial appendage (red asterisk). Ao: aorta: PA: pulmonary artery; RA: right atrium; RV: right ventricle; LA: left atrium; LV: left ventricle.A giant left atrial appendage is a rare cardiac anomaly that can be congenital or acquired. In the literature, it is called a left atrial appendage aneurysm. The dilatation can be generalized or focused. Although it can occur in all age groups, it is predominant in patients in their 30s to 50s and most common in females.¹ Patients can be asymptomatic or present with symptoms such as palpitations, chest pain, or dyspnea. A number of recent cases in the literature have highlighted the diagnostic utility of CTA.² While there is no standard treatment for this condition, surgical resection is the most frequent therapy. Another option reported in the literature is anticoagulant treatment for select cases.³ Closure of the left atrial appendage is a more recent and emerging intervention that can be considered.In our patient, we initiated anticoagulant therapy to reduce the risk of thromboembolic events; however, we recommended left atrial appendage occlusion or surgical resection after completing the treatment for pulmonary aspergillosis.     

Suicide Biomarkers to Predict Risk,Classify Diagnostic Subtypes,and Identify Novel Therapeutic Targets: 5 Years of Promising Research

BackgroundSuicide is a global health crisis. However, no objective biomarkers of suicide risk currently exist, and self-reported data can be unreliable, which limits prediction, diagnostic, and treatment efforts. Reliable biomarkers that can differentiate between diagnostic subgroups, predict worsening symptoms, or suggest novel therapeutic targets would be extremely valuable for patients, researchers, and clinicians.MethodsMEDLINE was searched for reports published between 2016 and 2021 using search terms (suicid*) AND (biomarker*) OR (indicat*). Reports that compared biomarkers between suicidal ideation, suicide attempt, death from suicide, or any suicide subgroup against other neuropsychiatric disorders were included. Studies exclusively comparing suicidal behavior or death from suicide with healthy controls were not included to ensure that biomarkers were specific to suicide and not other psychopathology.ResultsThis review summarizes the last 5 years of research into suicide-associated biomarkers and provides a comprehensive guide for promising and novel biomarkers that encompass varying presentations of suicidal ideation, suicide attempt, and death by suicide. The serotonergic system, inflammation, hypothalamic-pituitary-adrenal axis, lipids, and endocannabinoids emerged as the most promising diagnostic, predictive, and therapeutic indicators.ConclusionsThe utility of diagnostic and predictive biomarkers is evident, particularly for suicide prevention. While larger-scale studies and further in-depth research are required, the last 5 years of research has uncovered essential biomarkers that could ultimately improve predictive strategies, aid diagnostics, and help develop future therapeutic targets.     

Production and Upgrading of Recovered Carbon Black from the Pyrolysis of End-of-Life Tires

Increasing awareness regarding fossil fuel dependence, waste valorization, and greenhouse gas emissions have prompted the emergence of new solutions for numerous markets over the last decades. The tire industry is no exception to this, with a global production of more than 1.5 billion tires per year raising environmental concerns about their end-of-life recycling or disposal. Pyrolysis enables the recovery of both energy and material from end-of-life tires, yielding valuable gas, liquid, and solid fractions. The latter, known as recovered carbon black (rCB), has been extensively researched in the last few years to ensure its quality for market applications. These studies have shown that rCB quality depends on the feedstock composition and pyrolysis conditions such as type of reactor, temperature range, heating rate, and residence time. Recent developments of activation and demineralization techniques target the production of rCB with specific chemical, physical, and morphological properties for singular applications. The automotive industry, which is the highest consumer of carbon black, has set specific targets to incorporate recycled materials (such as rCB) following the principles of sustainability and a circular economy. This review summarizes the pyrolysis of end-of-life tires for the production of syngas, oil, and rCB, focusing on the process conditions and product yield and composition. A further analysis of the characteristics of the solid material is performed, including their influence on the rCB application as a substitute of commercial CB in the tire industry. Purification and modification post-treatment processes for rCB upgrading are also inspected.     

Cellular and Molecular Tissue Response to Triple Antibiotic Intracanal Dressing

Introduction

The aim of this study was to characterize the response of mouse subcutaneous tissue to triple antibiotic paste (TAP) using conventional light microscopy and real-time PCR (qRT-PCR).

Methods

Polyethylene tubes containing TAP or calcium hydroxide (CH) (ie, the control group) were implanted in mouse subcutaneous tissue. Animals that received empty tubes or no tubes were used as additional controls. After periods of 7, 21, and 63 days postimplantation, the specimens were removed and subjected to histologic processing. The number of inflammatory cells and vessels, vessel areas, vascular density, and relative percentage of collagen were evaluated. Gene expression of proinflammatory (interleukin-1 beta, tumor necrosis factor alpha, and interleukin 17) and anti-inflammatory (transforming growth factor beta) cytokines and angiogenic factors (vascular endothelial growth factor and hypoxia-inducible factor-1 alpha) was quantified by 7 and 21 days postimplantation. Results were analyzed using the Student t test, analysis of variance, and the Tukey test (α = 0.05).

Results

TAP induced an exuberant inflammatory and angiogenic response, with higher numbers of inflammatory cells, higher vascular area and density, and lower relative percentage of collagen compared with CH. In general, the expression of genes involved in inflammation and angiogenesis was higher in the TAP group compared with animals that received CH or empty tubes.

Conclusions

The response of mouse subcutaneous tissue to TAP was characterized by exuberant and persistent inflammatory and angiogenic responses with no repair and high gene expression of biomarkers associated with inflammation and angiogenesis.