ABSTRACT
We conduct Metropolis Monte Carlo simulations on models of dilute colloidal dispersions, where the particles interact via isotropic potentials of mean force (PMFs) that display a long-ranged repulsion, combined with a short-ranged and narrow attraction. Such systems are known to form anisotropic clusters. There are two main conclusions from this work. First, we demonstrate that the width of the attractive region has a significant impact on the type of structures that are formed. A narrow attractive well tends to produce clusters in which particles possess fewer neighbors than in systems where the attraction is wider. Second, metastable clusters appear to persist in the absence of specific simulation moves designed to overcome large energy barriers to particle accumulation. The so-called "Aggregation-Volume Bias Monte Carlo" moves were previously developed by Chen and Siepmann, and they facilitate particle exchanges between clusters via unphysical moves that bypass high energy intermediate states. These facilitate the progression of metastable clusters to equilibrium clusters. Metastable clusters are generally large with significant branching of thin filaments of aggregated particles, while stable clusters have thicker backbones and tend to be more compact with significantly fewer particles. This general behavior is observed in both two- and three-dimensional systems. In two dimensions, less anisotropic clusters with backbones possessing lattice structures will occur, particularly for systems where the particles interact with a PMF that has a relatively wide attractive region. We compare our results with PMF calculations established from a more specific model, namely weakly charged polystyrene particles, which carry a thin surface layer of grafted polyethylene oxide polymers in aqueous solution. We hope that our investigations can serve as crude guidelines for experimental research, aiming to construct linear or branched polymers in aqueous solution built up by colloidal monomers that are large enough to be studied by confocal microscopy. We suggest that metastable clusters are more relevant to experimental scenarios where the energetic barriers are too large to be surmounted over typical timescales.
Subject(s)
Lymphoma, B-Cell, Marginal Zone , Positron Emission Tomography Computed Tomography , Humans , Bone Marrow/diagnostic imaging , Bone Marrow/pathology , Lymphoma, B-Cell, Marginal Zone/diagnostic imaging , Lymphoma, B-Cell, Marginal Zone/pathology , Positron-Emission Tomography , Neoplasm Staging , Fluorodeoxyglucose F18 , Retrospective Studies , BiopsyABSTRACT
Introduction: Acute kidney injury (AKI) has been associated with an increased mortality rate among hospitalized patients with Coronavirus disease 2019 (COVID-19). The current review aimed to evaluate the symptoms, complications, and treatments performed to manage AKI in patients with COVID-19. Methods: We searched PubMed/Medline, Web of Science, and Embase for the relevant scientific literature published up to February 1, 2022. The following keywords were used: "COVID-19", "SARS-CoV-2", and "Acute kidney injury". Results: Forty-four studies with a total number of 114 COVID-19 patients with AKI (Mean age: 53.6 years) were included in our systematic review. The most common comorbidities in patients with COVID-19 suffering from AKI were the history of diabetes, hypertension, and hyperlipidemia. Twelve out of the 44 included studies reported a history of chronic kidney disease (CKD) in this group of patients. Focal segmental glomerulosclerosis (FSGS) and acute tubular necrosis (ATN) were the most common pathological evidence. The average length of hospital stay was 19 days, and the average duration of need for mechanical ventilation was 3 days. Conclusions: The current systematic review shows that AKI frequently complicates the course of COVID-19 hospitalizations and is associated with increased severity of illness, prolonged duration of hospitalization, and poor prognosis. Given the extent of the adverse impact of AKI, early detection of comorbidities and renal complications is essential to improve the outcomes of COVID-19 patients.
ABSTRACT
In this work, we have synthesized polystyrene particles that carry short end-grafted polyethylene glycol (PEG) chains. We then added dissolved 100 kDa PEG polymers and monitored potential flocculation by confocal microscopy. Qualitative predictions, based on previous theoretical developments in this field (Xie, F.; et al. Soft Matter 2016, 12, 658), suggest a non-monotonic temperature response. These theories propose that the "free" (dissolved) polymers will mediate attractive depletion interactions at room temperature, with a concomitant clustering/flocculation at a sufficiently high polymer concentration. At high temperatures, where the solvent is poorer, this is predicted to be replaced by attractive bridging interactions, again resulting in particle condensation. Interestingly enough, our theoretical framework, based on classical density functional theory, predicts an intermediate temperature regime where the polymer-mediated interactions are repulsive! This obviously implies a homogeneous dispersion in this regime. These qualitative predictions have been experimentally tested and confirmed in this work, where flocs of particles start to form at room temperature for a high enough polymer dosage. At temperatures near 45 °C, the flocs redisperse, and we obtain a homogeneous sample. However, samples at about 75 °C will again display clusters and eventually phase separation. Using results from these studies, we have been able to fine-tune parameters of our coarse-grained theoretical model, resulting in predictions of temperature-dependent stability that display semiquantitative accuracy. A crucial aspect is that under "intermediate" conditions, where the polymers neither adsorb nor desorb at the particle surfaces, the polymer-mediated equilibrium interaction is repulsive.
ABSTRACT
Sarcoidosis is a granulomatous inflammatory disease of unknown etiology. Sarcoid like granuloma may develop concurrently or following cancer. Detection of granuloma in mediastinal lymph nodes biopsy in patient with pulmonary nodules may be a concern for undiagnosed lung cancer. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a diagnostic modality of choice for the lung lesions. We discussed A 71-year-old man with history of chronic obstructive lung disease (COPD), who presented with a lung nodule and mediastinal lymphadenopathies. The nodule was 9.9 mm when detected and his endobronchial ultrasound-guided transbronchial fine needle aspiration (EBUS-TBNA) of lymph nodes in station 7 & 4R showed normal lymph node structure. Two years later, his surveillance chest CT scan indicated an increase in the size of the nodule to 15 mm, and PET/CT showed Fluorodeoxyglucose (FDG) avid nodule & mediastinal Lymph nodes. He complained of Shortness of breath after 2-3 climbs of stairs, without any history of cough or fever. He quit cigarette smoking recently and smoked 50 pack years before. He underwent another set of EBUS and was referred for sarcoidosis treatment due to finding non-necrotizing granuloma in 4L and 11L lymph nodes. The patient also underwent another biopsy of the nodule concerning the possibility of cancer sarcoid syndrome. A poorly differentiated lung adenocarcinoma positive for GATA3, positive for P63 and CK7, TTF-1 was reported. Concurrent lung cancer and granulomatous reaction in mediastinal lymph nodes are being reported more often. Recent studies have shown a better survival of patients with diagnosis of cancer and granulomatous findings of sarcoidosis. Performing lung biopsy from any nodular lesion in a patient with sarcoidosis is essential for the differential diagnosis and early therapeutic measures.
ABSTRACT
HYPOTHESIS: Colloidal particles that interact via a long-ranged repulsive barrier in combination with a very short-ranged attractive minimum can "polymerize" to form highly anisotropic structures. Motivated by previous experimental achievements in non-aqueous solvents, and recent theoretical predictions, we hypothesize that it is possible to construct clusters that resemble linear or branched polymers, in aqueous solution. If these clusters are not too large, they may even remain dispersed, but even if they grow large enough to sediment, they may be collected and used in future applications. EXPERIMENTS: In this work, we specifically synthesize poly (ethylene glycol) (PEG) chains, grafted onto poly (styrene) (PS) particles in aqueous solution, and adjust the conditions so that strongly anisotropic and isolated polymer-like clusters are formed. These conditions include a very low ionic strength (the particles are weakly charged), a relatively high temperature, and a low particle concentration. An important criterion is that the particle size is large enough to admit structural analyses via confocal laser scanning microscopy (CLSM). We have furthermore utilized Metropolis Monte Carlo (MC) simulation to generate theoretical predictions of these cluster formations. We have conducted such simulations of 3D as well as 2D systems, where the latter is also relevant, given that the clusters sometimes deposit onto the glass surfaces upon imaging. A simplistic particle-particle potential of mean force is adopted for the simulations, but we also invoke a more elaborate theoretical model, to demonstrate that similar interactions can be obtained when the grafted chains are treated explicitly. FINDINGS: According to our Zeta potential measurements, the particles indeed carry a weak negative charge, presumably due to ion specific adsorption. Furthermore, by ensuring that the ionic strength is very low, with a Debye length similar to the particle size, we could use temperature to control the hydrophobicity of the grafted PEG layer, and thus the strength of the short-ranged attraction. We were indeed able to establish highly anisotropic structures, that resemble linear or branched polymers, which we could image by CLSM. The average degree of polymerization could be adjusted by a variation of the particle concentration.
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INTRODUCTION: The association between Coronavirus Disease 2019 (COVID-19) and abortion has been debated since the beginning of the COVID-19 pandemic. We aimed to conduct this systematic review to understand better the potential effects of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) on fetal loss in infected mothers presented with abortion following this infection. METHODS: We included articles published in PubMed/Medline, Web of Science, clinicaltrials.gov, and Embase databases in 2019 and 2020 through a comprehensive search via appropriate keywords, including COVID-19 and abortion synonyms. All studies with the abortion data in COVID-19 confirmed pregnant females were collected. RESULTS: Out of 208 potentially relevant articles, 11 articles were eligible to include in the systematic review. The included reports were published because of the following reasons: (1) First-trimester miscarriage; (2) Late miscarriage; (3) complication of COVID-19 infection in pregnancy; (4) COVID-19 disease in artificial pregnancy. First-trimester abortion was found in 5 studies, and second-trimester abortion in 7 studies. Two patients acquired infection during the hospital stay while they were referred for abortion. Reports related to abortion in pregnant females with COVID-19 show that most miscarriages due to COVID-19 in the first trimester were due to placental insufficiency. CONCLUSIONS: There is an increased risk of abortion in mothers with a positive test result of SARS-CoV-2, which several case reports and case series have identified during the pandemic. Placental inflammation during the viral infection may result in fetal growth retardation and induce abortion. There has not been any consistent evidence of vertical transmission of the virus from mother to fetus, which requires further investigation.
Subject(s)
COVID-19/diagnosis , Pregnancy Outcome , Abortion, Induced , Abortion, Spontaneous , COVID-19/epidemiology , COVID-19/virology , Databases, Factual , Female , Humans , Pandemics , Pregnancy , SARS-CoV-2/isolation & purificationABSTRACT
The Nucleocapsid Protein (N Protein) of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV2) is located in the viral core. Immunoglobulin G (IgG) targeting N protein is detectable in the serum of infected patients. The effect of high titers of IgG against N-protein on clinical outcomes of SARS-CoV2 disease has not been described. We studied 400 RT-PCR confirmed SARS-CoV2 patients to determine independent factors associated with poor outcomes, including Medical Intensive Care Unit (MICU) admission, prolonged MICU stay and hospital admissions, and in-hospital mortality. We also measured serum IgG against the N protein and correlated its concentrations with clinical outcomes. We found that several factors, including Charlson comorbidity Index (CCI), high levels of IL6, and presentation with dyspnea were associated with poor clinical outcomes. It was shown that higher CCI and higher IL6 levels were independently associated with in-hospital mortality. Anti-N protein IgG was detected in the serum of 55 (55%) patients at the time of admission. A high concentration of antibodies, defined as signal to cut off ratio (S/Co) > 1.5 (75 percentile of all measurements), was found in 25 (25%) patients. The multivariable logistic regression models showed that between being an African American, higher CCI, lymphocyte counts, and S/Co ratio > 1.5, only S/Co ratio were independently associated with MICU admission and longer length of stay in hospital. This study recommends that titers of IgG targeting N-protein of SARS-CoV2 at admission is a prognostic factor for the clinical course of disease and should be measured in all patients with SARS-CoV2 infection.
Subject(s)
COVID-19/immunology , Immunoglobulin G/immunology , Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , Female , Humans , Immunoglobulin G/blood , Intensive Care Units , Length of Stay , Male , Middle Aged , Prognosis , Spike Glycoprotein, Coronavirus/immunologyABSTRACT
Alcohol abuse along with difficulties in communication has led to increased morbidity and mortality among patients with psychiatric disorders. This issue has a higher importance during the COVID-19 Pandemic. Standard recommendations to prevent the spread of infection such as self-quarantine, hand washing, covering mouth and nose while coughing may be difficult to enforce in patients with mental illnesses. There is a controversy in discharge and management of patients with history of alcohol abuse and psychiatric disorders when they come to the Emergency Departments (ED) with mild presentation of COVID-19. We discussed a 39 years old patient known case of paranoid schizophrenia who came to the ED with mild fever, cough and headache. She was soon discharged from the ED after having a normal chest radiograph. She was recommended to be in self-quarantine for at least 14 days. Her COVID-19 condition deteriorated rapidly in a week, and she was brought back to the ED after she had an altercation with her friends while drinking. Patients with psychiatric disorders especially schizophrenia or those who have been diagnosed with alcohol abuse may have a higher risk for progression of their mild COVID-19 to a severe form. On the other hand, they have a role in the spread of COVID-19 in the community due to lower compliance with preventive measures. A higher rate of alcohol abuse in psychiatric patients and their lower compliance to self-quarantine calls for a different approach when they come to the ED with COVID-19 presentations.
ABSTRACT
Background: The rapidly evolving coronavirus disease 2019 (COVID-19), was declared a pandemic by the World Health Organization on March 11, 2020. It was first detected in the Wuhan city of China and has spread globally resulting in a substantial health and economic crisis in many countries. Observational studies have partially identified different aspects of this disease. There have been no published systematic reviews that combine clinical, laboratory, epidemiologic, and mortality findings. Also, the effect of gender on the outcomes of COVID-19 has not been well-defined. Methods: We reviewed the scientific literature published from January 1, 2019 to May 29, 2020. Statistical analyses were performed with STATA (version 14, IC; Stata Corporation, College Station, TX, USA). The pooled frequency with 95% confidence intervals (CI) was assessed using random effect model. P < 0.05 was considered a statistically significant publication bias. Results: Out of 1,223 studies, 34 satisfied the inclusion criteria. A total of 5,057 patients with a mean age of 49 years were evaluated. Fever (83.0%, CI 77.5-87.6) and cough (65.2%, CI 58.6-71.2) were the most common symptoms. The most prevalent comorbidities were hypertension (18.5%, CI 12.7-24.4) and Cardiovascular disease (14.9%, CI 6.0-23.8). Among the laboratory abnormalities, elevated C-Reactive Protein (CRP) (72.0%, CI 54.3-84.6) and lymphopenia (50.1%, CI 38.0-62.4) were the most common. Bilateral ground-glass opacities (66.0%, CI 51.1-78.0) was the most common CT scan presentation. The pooled mortality rate was 6.6%, with males having significantly higher mortality compared to females (OR 3.4; 95% CI 1.2-9.1, P = 0.01). Conclusion: COVID-19 has caused a significant number of hospitalization and mortality worldwide. Mortality associated with COVID-19 was higher in our study compared to the previous reports from China. The mortality was significantly higher among the hospitalized male group. Further studies are required to evaluate the effect of different variables resulting in sex disparity in COVID-19 mortality.
ABSTRACT
Off-label tocilizumab use in COVID-19 patients reflects concern for cytokine release syndrome. Comparison of matched COVID-19 pneumonia patients found elevated IL-6 levels correlated with mortality that did not change with tocilizumab administration. Correlating mortality with increased IL-6 doesn't imply causality however lack of improvement by tocilizumab requires further clinical trial alterations.
Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/immunology , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/mortality , Coronavirus Infections/virology , Female , Ferritins/analysis , Humans , Interleukin-6/analysis , Male , Middle Aged , Odds Ratio , Pandemics , Pneumonia, Viral/mortality , Pneumonia, Viral/virology , Proportional Hazards Models , Receptors, Interleukin-6/immunology , SARS-CoV-2 , Survival RateABSTRACT
BACKGROUND: Non-Hodgkin's lymphoma (NHL) is a heterogeneous type of neoplasm of the lymphatic system. To have a more accurate and early diagnosis we need to know signs, symptoms and complications of lymphoma in early stages besides pathology and immunohistochemistry. MATERIALS AND METHODS: This prospective study included 110 cases of NHL that were followed since February 2012 till November 2013. Biopsies were taken from all the patients besides bone marrow study. Signs and symptoms were categorized into "B" symptoms, general, lymphadenopathy and extranodal involvement and we compared the frequencies by stage and grade. RESULTS: Of 110 cases, 88.9% had B-cell and 11.1% T-cell type with mean age 48.5±18.6 years. "B" symptoms and lymphadenopathy were more common in men. Cervical lymphadenopathy was the most common sign (44.8%). and hematologic, bone marrow, bone and neurologic lesions were the most common complications. All complications were more common in males. "B" symptoms were seen mostly in stage III, general signs and symptoms in stage IV, and lymphadenopathy in stage II. Intermediate grade was also the most common in all signs and symptoms. In this study 12 (10.9%) patients had relapse, with neurologic and bone marrow as the most common sites of tumor recurrence. CONCLUSIONS: There is a meaningful relationship between male gender for NHL and anemia that can be due in part to higher incidence of bone marrow involvement and stage IV disease in male cases. We also found a strong relationship between low grade NHL and age. On the other hand extranodal involvement is more common in female groups.