Characteristics and Risk Factors of Hospitalized and Nonhospitalized COVID-19 Patients, Atlanta, Georgia, USA, March-April 2020

We compared the characteristics of hospitalized and nonhospitalized patients who had coronavirus disease in Atlanta, Georgia, USA. We found that risk for hospitalization increased with a patient’s age and number of concurrent conditions. We also found a potential association between hospitalization and high hemoglobin A1c levels in persons with diabetes.

COVID-19 Clinical Phenotypes: Presentation and Temporal Progression of Disease in a Cohort of Hospitalized Adults in Georgia, United States

BACKGROUND

The epidemiological features and outcomes of hospitalized adults with coronavirus disease 2019 (COVID-19) have been described; however, the temporal progression and medical complications of disease among hospitalized patients require further study. Detailed descriptions of the natural history of COVID-19 among hospitalized patients are paramount to optimize health care resource utilization, and the detection of different clinical phenotypes may allow tailored clinical management strategies.

METHODS

This was a retrospective cohort study of 305 adult patients hospitalized with COVID-19 in 8 academic and community hospitals. Patient characteristics included demographics, comorbidities, medication use, medical complications, intensive care utilization, and longitudinal vital sign and laboratory test values. We examined laboratory and vital sign trends by mortality status and length of stay. To identify clinical phenotypes, we calculated Gower's dissimilarity matrix between each patient's clinical characteristics and clustered similar patients using the partitioning around medoids algorithm.

RESULTS

One phenotype of 6 identified was characterized by high mortality (49%), older age, male sex, elevated inflammatory markers, high prevalence of cardiovascular disease, and shock. Patients with this severe phenotype had significantly elevated peak C-reactive protein creatinine, D-dimer, and white blood cell count and lower minimum lymphocyte count compared with other phenotypes (P < .01, all comparisons).

CONCLUSIONS

Among a cohort of hospitalized adults, we identified a severe phenotype of COVID-19 based on the characteristics of its clinical course and poor prognosis. These findings need to be validated in other cohorts, as improved understanding of clinical phenotypes and risk factors for their development could help inform prognosis and tailored clinical management for COVID-19.

Predictors at admission of mechanical ventilation and death in an observational cohort of adults hospitalized with COVID-19

Background

Coronavirus disease (COVID-19) can cause severe illness and death. Predictors of poor outcome collected on hospital admission may inform clinical and public health decisions.

Methods

We conducted a retrospective observational cohort investigation of 297 adults admitted to eight academic and community hospitals in Georgia, United States, during March 2020. Using standardized medical record abstraction, we collected data on predictors including admission demographics, underlying medical conditions, outpatient antihypertensive medications, recorded symptoms, vital signs, radiographic findings, and laboratory values. We used random forest models to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CI) for predictors of invasive mechanical ventilation (IMV) and death.

Results

Compared with age <45 years, ages 65–74 years and ≥75 years were predictors of IMV (aOR 3.12, CI 1.47–6.60; aOR 2.79, CI 1.23–6.33) and the strongest predictors for death (aOR 12.92, CI 3.26–51.25; aOR 18.06, CI 4.43–73.63). Comorbidities associated with death (aORs from 2.4 to 3.8, p <0.05) included end-stage renal disease, coronary artery disease, and neurologic disorders, but not pulmonary disease, immunocompromise, or hypertension. Pre-hospital use vs. non-use of angiotensin receptor blockers (aOR 2.02, CI 1.03–3.96) and dihydropyridine calcium channel blockers (aOR 1.91, CI 1.03–3.55) were associated with death.

Conclusions

After adjustment for patient and clinical characteristics, older age was the strongest predictor of death, exceeding comorbidities, abnormal vital signs, and laboratory test abnormalities. That coronary artery disease, but not chronic lung disease, was associated with death among hospitalized patients warrants further investigation, as do associations between certain antihypertensive medications and death.

Characteristics Associated with Hospitalization Among Patients with COVID-19 - Metropolitan Atlanta, Georgia, March-April 2020

The first reported U.S. case of coronavirus disease 2019 (COVID-19) was detected in January 2020 (1). As of June 15, 2020, approximately 2 million cases and 115,000 COVID-19-associated deaths have been reported in the United States.* Reports of U.S. patients hospitalized with SARS-CoV-2 infection (the virus that causes COVID-19) describe high proportions of older, male, and black persons (2-4). Similarly, when comparing hospitalized patients with catchment area populations or nonhospitalized COVID-19 patients, high proportions have underlying conditions, including diabetes mellitus, hypertension, obesity, cardiovascular disease, chronic kidney disease, or chronic respiratory disease (3,4). For this report, data were abstracted from the medical records of 220 hospitalized and 311 nonhospitalized patients aged ≥18 years with laboratory-confirmed COVID-19 from six acute care hospitals and associated outpatient clinics in metropolitan Atlanta, Georgia. Multivariable analyses were performed to identify patient characteristics associated with hospitalization. The following characteristics were independently associated with hospitalization: age ≥65 years (adjusted odds ratio [aOR] = 3.4), black race (aOR = 3.2), having diabetes mellitus (aOR = 3.1), lack of insurance (aOR = 2.8), male sex (aOR = 2.4), smoking (aOR = 2.3), and obesity (aOR = 1.9). Infection with SARS-CoV-2 can lead to severe outcomes, including death, and measures to protect persons from infection, such as staying at home, social distancing (5), and awareness and management of underlying conditions should be emphasized for those at highest risk for hospitalization with COVID-19. Measures that prevent the spread of infection to others, such as wearing cloth face coverings (6), should be used whenever possible to protect groups at high risk. Potential barriers to the ability to adhere to these measures need to be addressed.

Inducing apoptosis of cancer cells using small-molecule plant compounds that bind to GRP78

Background:

Glucose regulated protein 78 (GRP78) functions as a sensor of endoplasmic reticulum (ER) stress. The aim of this study was to test the hypothesis that molecules that bind to GRP78 induce the unfolded protein response (UPR) and enhance cell death in combination with ER stress inducers.

Methods:

Differential scanning calorimetry (DSC), measurement of cell death by flow cytometry and the induction of ER stress markers using western blotting.

Results:

Epigallocatechin gallate (EGCG), a flavonoid component of Green Tea Camellia sinensis, and honokiol (HNK), a Magnolia grandiflora derivative, bind to unfolded conformations of the GRP78 ATPase domain. Epigallocatechin gallate and HNK induced death in six neuroectodermal tumour cell lines tested. Levels of death to HNK were twice that for EGCG; half-maximal effective doses were similar but EGCG sensitivity varied more widely between cell types. Honokiol induced ER stress and UPR as predicted from its ability to interact with GRP78, but EGCG was less effective. With respect to cell death, HNK had synergistic effects on melanoma and glioblastoma cells with the ER stress inducers fenretinide or bortezomib, but only additive (fenretinide) or inhibitory (bortezomib) effects on neuroblastoma cells.

Conclusion:

Honokiol induces apoptosis due to ER stress from an interaction with GRP78. The data are consistent with DSC results that suggest that HNK binds to GRP78 more effectively than EGCG. Therefore, HNK may warrant development as an antitumour drug.

Disruption of the mitochondrial thioredoxin system as a cell death mechanism of cationic triphenylmethanes

Alterations in mitochondrial structure and function are a hallmark of cancer cells compared to normal cells and thus targeting mitochondria has emerged as an novel approach to cancer therapy. The mitochondrial thioredoxin 2 (Trx2) system is critical for cell viability, but its role in cancer biology is not well understood. Recently some cationic triphenylmethanes such as brilliant green (BG) and gentian violet were shown to have antitumor and antiangiogenic activity with unknown mechanisms. Here we demonstrate that BG killed cells at nanomolar concentrations and targeted mitochondrial Trx2, which was oxidized and degraded. HeLa cells were more sensitive to BG than fibroblasts. In HeLa cells, Trx2 down-regulation by siRNA resulted in increased sensitivity to BG, whereas for fibroblasts, the same treatments had no effect. BG was observed to accumulate in mitochondria and cause a rapid and dramatic decrease in mitochondrial Trx2 protein. With a redox Western blot method, we found that treatment with BG caused oxidation of both Trx1 and Trx2, followed by release of cytochrome c and apoptosis-inducing factor from the mitochondria into the cytosol. Moreover, this treatment resulted in an elevation of the mRNA level of Lon protease, a protein quality control enzyme in the mitochondrial matrix, suggesting that the oxidized Trx2 may be degraded by Lon protease.

Fulvene-5 potently inhibits NADPH oxidase 4 and blocks the growth of endothelial tumors in mice

Hemangiomas are the most common type of tumor in infants. As they are endothelial cell-derived neoplasias, their growth can be regulated by the autocrine-acting Tie2 ligand angiopoietin 2 (Ang2). Using an experimental model of human hemangiomas, in which polyoma middle T-transformed brain endothelial (bEnd) cells are grafted subcutaneously into nude mice, we compared hemangioma growth originating from bEnd cells derived from wild-type, Ang2+/-, and Ang2-/- mice. Surprisingly, Ang2-deficient bEnd cells formed endothelial tumors that grew rapidly and were devoid of the typical cavernous architecture of slow-growing Ang2-expressing hemangiomas, while Ang2+/- cells were greatly impaired in their in vivo growth. Gene array analysis identified a strong downregulation of NADPH oxidase 4 (Nox4) in Ang2+/- cells. Correspondingly, lentiviral silencing of Nox4 in an Ang2-sufficient bEnd cell line decreased Ang2 mRNA levels and greatly impaired hemangioma growth in vivo. Using a structure-based approach, we identified fulvenes as what we believe to be a novel class of Nox inhibitors. We therefore produced and began the initial characterization of fulvenes as potential Nox inhibitors, finding that fulvene-5 efficiently inhibited Nox activity in vitro and potently inhibited hemangioma growth in vivo. In conclusion, the present study establishes Nox4 as a critical regulator of hemangioma growth and identifies fulvenes as a potential class of candidate inhibitor to therapeutically interfere with Nox function.

The natural product honokiol preferentially inhibits cellular FLICE-inhibitory protein and augments death receptor-induced apoptosis

Targeting death receptor-mediated apoptosis has emerged as an effective strategy for cancer therapy. However, certain types of cancer cells are intrinsically resistant to death receptor-mediated apoptosis. In an effort to identify agents that can sensitize cancer cells to death receptor-induced apoptosis, we have identified honokiol, a natural product with anticancer activity, as shown in various preclinical studies, as an effective sensitizer of death receptor-mediated apoptosis. Honokiol alone moderately inhibited the growth of human lung cancer cells; however, when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), greater effects on decreasing cell survival and inducing apoptosis than TRAIL alone were observed, indicating that honokiol cooperates with TRAIL to enhance apoptosis. This was also true to Fas-induced apoptosis when combined with Fas ligand or an agonistic anti-Fas antibody. Among several apoptosis-associated proteins tested, cellular FLICE-inhibitory protein (c-FLIP) was the only one that was rapidly down-regulated by honokiol in all of the tested cell lines. The down-regulation of c-FLIP by honokiol could be prevented by the proteasome inhibitor MG132. Moreover, honokiol increased c-FLIP ubiquitination. These results indicate that honokiol down-regulates c-FLIP by facilitating its degradation through a ubiquitin/proteasome-mediated mechanism. Enforced expression of ectopic c-FLIP abolished the ability of honokiol to enhance TRAIL-induced apoptosis. Several honokiol derivatives, which exhibited more potent effects on down-regulation of c-FLIP than honokiol, showed better efficacy than honokiol in inhibiting the growth and enhancing TRAIL-induced apoptosis as well. Collectively, we conclude that c-FLIP down-regulation is a key event for honokiol to modulate the death receptor-induced apoptosis.

Fumagillin: an anti-infective as a parent molecule for novel angiogenesis inhibitors

Fumagillin is an active amebicide and anti-infective isolated from the fungus Aspergillus fumigatus. Since its characterization in 1951, fumagillin has been studied extensively for its anti-infective properties. Although fumagillin is not approved for systemic use in the USA, this compound has one of the highest efficacies for the treatment of microsporidial infections in HIV-positive patients. Fumagillin does exhibit some side effects that have deterred its acceptance as a viable treatment, but the current body of research on the synthesis of novel analogs of this molecule shows an exciting and promising revival of this drug as both an anti-infective and antiangiogenic agent.

Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells?

Angiomyolipomas are benign tumors of the kidney which express phenotypes of smooth muscle, fat, and melanocytes. These tumors appear with increased frequency in the autosomal dominant disorder tuberous sclerosis and are the leading cause of morbidity in adults with tuberous sclerosis. While benign, these tumors are capable of provoking life threatening hemorrhage and replacement of the kidney parenchyma, resulting in renal failure. The histogenesis of these tumors is currently unclear, although currently, we believe these tumors arise from "perivascular epithelioid cells" of which no normal counterpart has been convincingly demonstrated. Recently, stem cell precursors have been recognized that can give rise to smooth muscle and melanocytes. These precursors have been shown to express the neural stem cell marker NG2 and L1. In order to determine whether angiomyolipomas, which exhibit smooth muscle and melanocytic phenotypes, express NG2 and L1, we performed immunocytochemistry on a cell line derived from a human angiomyolipoma, and found that these cells are uniformly positive. Immunohistochemistry of human angiomyolipoma specimens revealed uniform staining of tumor cells, while renal cell carcinomas revealed positivity only of angiogenic vessels. These results support a novel histogenesis of angiomyolipoma as a defect in differentiation of stem cell precursors.

Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells?

Angiomyolipomas are benign tumors of the kidney which express phenotypes of smooth muscle, fat, and melanocytes. These tumors appear with increased frequency in the autosomal dominant disorder tuberous sclerosis and are the leading cause of morbidity in adults with tuberous sclerosis. While benign, these tumors are capable of provoking life threatening hemorrhage and replacement of the kidney parenchyma, resulting in renal failure. The histogenesis of these tumors is currently unclear, although currently, we believe these tumors arise from "perivascular epithelioid cells" of which no normal counterpart has been convincingly demonstrated. Recently, stem cell precursors have been recognized that can give rise to smooth muscle and melanocytes. These precursors have been shown to express the neural stem cell marker NG2 and L1. In order to determine whether angiomyolipomas, which exhibit smooth muscle and melanocytic phenotypes, express NG2 and L1, we performed immunocytochemistry on a cell line derived from a human angiomyolipoma, and found that these cells are uniformly positive. Immunohistochemistry of human angiomyolipoma specimens revealed uniform staining of tumor cells, while renal cell carcinomas revealed positivity only of angiogenic vessels. These results support a novel histogenesis of angiomyolipoma as a defect in differentiation of stem cell precursors.

Synthesis, cytotoxicity, and antiviral activities of new neolignans related to honokiol and magnolol

A series of new bisphenol derivatives bearing allylic moieties were synthesized as potential analogs of honokiol and/or magnolol. Certain compounds exhibited specific anti-proliferation activity against SVR cells and moderate anti-HIV-1 activity in primary human lymphocytes. Compound 5h was the most potent compound and its anti-tumor activity was evaluated in vivo.

Transgenic Expression of Dominant Negative Tuberin through a Strong Constitutive Promoter Results in a Tissue-specific Tuberous Sclerosis Phenotype in the Skin and Brain

Tuberous sclerosis (TS) is a common autosomal dominant disorder caused by loss or malfunction of hamartin (tsc1) or tuberin (tsc2). Many lesions in TS do not demonstrate loss of heterozygosity for these genes, implying that dominant negative forms of these genes may account for some hamartomas and neoplasms in TS. To test this hypothesis, we expressed a dominant negative allele of tuberin (DeltaRG) behind the cytomegalovirus promoter in NIH3T3 cells and transgenic mice. This allele binds hamartin but has a deletion in the C terminus of tuberin, leading to constitutive activation of rap1 and rab5/rabaptin. Expression of DeltaRG in NIH3T3 cells led to a strong induction of reactive oxygen species, induction of vascular endothelial growth factor, and malignant transformation in vivo. Expression of DeltaRG driven by the constitutive cytomegalovirus promoter led to high level expression in all murine tissues examined, including skin, kidney, liver, and brain. Surprisingly, mice expressing the DeltaRG transgene developed a fibrovascular collagenoma in the dermis, which closely resembles the Shagreen patch observed in human patients with TS. In addition, numerous small subpial collections of external granule cells in the cerebellum were observed, which may be the murine equivalent of subependymal giant cell astrocytomas or tubers commonly seen in TS patients. Thus, expression of a dominant negative tuberin in multiple tissues can lead to a tissue-specific phenotype resembling some of the findings in human TS. Our data are the first to demonstrate that specific signaling abnormalities underlie specific hamartomas in a model of a human genetic disorder.