We report the neuropathological findings of a patient who died from complications of COVID-19. The decedent was initially hospitalized for surgical management of underlying coronary artery disease. He developed post-operative complications and was evaluated with chest imaging studies. The chest computed tomography (CT) imaging results were indicative of COVID-19 and he was subsequently tested for SARS-CoV-2, which was positive. His condition worsened and he died after more than 2 weeks of hospitalization and aggressive treatment. The autopsy revealed a range of neuropathological lesions, with features resembling both vascular and demyelinating etiologies. Hemorrhagic white matter lesions were present throughout the cerebral hemispheres with surrounding axonal injury and macrophages. The subcortical white matter had scattered clusters of macrophages, a range of associated axonal injury, and a perivascular acute disseminated encephalomyelitis (ADEM)-like appearance. Additional white matter lesions included focal microscopic areas of necrosis with central loss of white matter and marked axonal injury. Rare neocortical organizing microscopic infarcts were also identified. Imaging and clinical reports have demonstrated central nervous system complications in patients' with COVID-19, but there is a gap in our understanding of the neuropathology. The lesions described in this case provide insight into the potential parainfectious processes affecting COVID-19 patients, which may direct clinical management and ongoing research into the disease. The clinical course of the patient also illustrates that during prolonged hospitalizations neurological complications of COVID may develop, which are particularly difficult to evaluate and appreciate in the critically ill.
Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its resultant clinical presentation, COVID-19, is an emergent cause of mortality worldwide. Cardiac complications secondary to this infection are common; however, the underlying mechanisms of such remain unclear. A detailed cardiac evaluation of a series of COVID-19 individuals undergoing postmortem evaluation is provided, with four aims: 1) describe the pathologic spectrum of the myocardium; 2) compare to an alternate viral illness; 3) investigate angiotensin converting enzyme 2 (ACE2) expression; and 4) provide the first description of the cardiac findings in patients with cleared infection. Methods: Study cases were identified from institutional files and included COVID-19 (n=15; 12 active, 3 cleared), influenza A/B (n=6), and non-virally mediated deaths (n=6). Salient information was abstracted from the medical record. Light microscopic findings were recorded. An ACE2 immunohistochemical H-score was compared across cases. Viral detection encompassed SARS-CoV-2 immunohistochemistry, ultrastructural examination, and droplet digital polymerase chain reaction (ddPCR). Results: Male sex was more common in the COVID-19 group (p=0.05). Non-occlusive fibrin microthrombi (without ischemic injury) were identified in 16 cases (12 COVID-19, 2 influenza, and 2 controls), and were more common in the active COVID-19 cohort (p=0.006). Four active COVID-19 cases showed focal myocarditis, while one case of cleared COVID-19 showed extensive disease. Arteriolar ACE2 endothelial expression was lower in COVID-19 cases versus controls (p=0.004). ACE2 myocardial expression did not differ by disease category, sex, age or number of patient comorbidities (p=0.69, p=1.00, p=0.46, p=0.65, respectively). SARS-CoV-2 immunohistochemistry showed non-specific staining, while ultrastructural examination and ddPCR were negative for viral presence. Four (26.7%) COVID-19 patients had underlying cardiac amyloidosis. Cases with cleared infection had variable presentations. Conclusions: This detailed histopathologic, immunohistochemical, ultrastructural and molecular cardiac series showed no definitive evidence of direct myocardial infection. COVID-19 cases frequently have cardiac fibrin microthrombi, without universal acute ischemic injury. Moreover, myocarditis is present in 33.3% of active and cleared COVID-19 patients, but is usually limited in extent. Histologic features of resolved infection are variable. Cardiac amyloidosis may be an additional risk factor for severe disease.
Antibiotic resistance is emerging at an alarming rate, outpacing current research and development efforts to combat this trend. As a result, many infectious diseases have become difficult to treat; in some cases, no treatment options exist. The search for new antibiotics must accelerate to avoid returning to the 'pre-antibiotic' era. Ancient remedies, including essential oils and their components, have been explored on a limited basis as a source of new antimicrobials. Many are known to possess significant antimicrobial activity against a wide range of microorganisms. Elucidation of the mechanism of action of these compounds may lead to identification new antibiotic targets. Such targets, once identified, may represent biosynthetic or regulatory pathways not currently inhibited by available drugs. Novel drugs and targets are vital for continued control of infectious diseases worldwide.
The causative agent of White-nose Syndrome (WNS), Pseudogymnoascus destructans, has been shown to be fatal to several species of bats in North America. To date, no compounds or chemical control measures have been developed which eliminates the growth of the fungus in the environment or in affected animals. In the current study, we evaluated the activity of cold-pressed, terpeneless orange oil (CPT) against multiple isolates of P. destructans in vitro. For all assays, a modified Kirby-Bauer disk diffusion assay was used. Standardized spore suspensions were prepared, adjusted to a specific optical density, and used to plate fungal lawns. Plates were incubated at either 15°C or 4°C for up to 6 months and checked at regular intervals for growth. Once controls had grown, zones of inhibition were measured (mm) on test plates and compared to those obtained using current antifungal drugs. All P. destructans isolates were completely inhibited by 100% CPT (10 μL) at 1 month of incubation regardless of temperature (4°C and 15°C). Complete inhibition persisted up to 6 months following a single exposure at this concentration. Of the standard antifungals, only amphotericin B demonstrated any activity, resulting in zone diameters ranging from 58 mm to 74 mm. CPT, at the highest concentration tested (100%), had no significant effect against a variety of other environmental organisms including various filamentous fungi, bacteria and aerobic actinomycetes. Given that CPT is relatively non-toxic, the possibility exists that the all-natural, mixture could be used as an environmental pre-treatment to eradicate P. destructans from bat habitats. Additional studies are needed to assess any undesirable effects of CPT on bat behavior and health and overall impacts on other members of the interconnected ecosystem(s).
Dermatophytoses account for nearly a quarter of all fungal infections worldwide. These difficult to treat infections of the skin, hair, and nails, are growing more resistant to conventional antifungal treatments, and when treatable, often require prolonged therapeutic regimens. For centuries, essential oils have been used to treat a variety of ailments. In this study, we evaluated the clinical effects in vitro of 65 essential oils and 21 essential oil blends against various clinical species/strains of dermatophytes from two primary genera, Microsporum and Trichophyton. Our aim: To determine the overall activity of a wide range of essential oils against a number of clinical strains of dermatophytes. For all assays, 16 clinically derived species/strains of dermatophytes were used. The activity of each essential oil was assessed using a modified disk-diffusion assay over a period of 21 days of incubation vs. standard antifungal drugs. Subsequently, we determined the minimum inhibitory dilution possible for the most potent essential oils and performed combination testing to determine if synergy could be demonstrated with sub-inhibitory concentrations. We also assessed the effect of repeated vs. single applications. Of all the essential oils tested, cassia, cilantro, cinnamon, thyme, and oregano were the most potent along with one blend, DDR Prime; all genera/species tested were completely inhibited for 21 days following a single application. Many of the other oils tested exhibited temporal differences in activity where significant inhibition was observed ≤10 days of incubation which declined by day 21. Synergistic combinations were achieved with oregano and cilantro, cassia, or cinnamon bark; rose and cassia were also synergistic. Repeat application maintained complete inhibition for citronella, lemon myrtle, and litsea out to 21 days, but not lemon grass or On Guard. More study is necessary to understand the ways essential oils inhibit the growth of dermatophytes. Comprehensive research aimed at understanding the mechanism of action of essential oils and their components may provide the basis for a natural alternative to topical antifungal drugs. Such research could be envisioned to target optimal combinations and determine the timing between applications to provide for maximum inhibition of recurrence or growth.
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