Relationship Between Day of Starting Steroid and Clinical Outcome in Hospitalized Covid-19 Patients

Various guidelines recommend steroid in only severe COVID-19 patients. But in hospitals steroids are being rampantly used even at the beginning of symptom onset. Some studies indicate starting steroid only in severe and/or patients on mechanical ventilation while some suggest starting in first 5-7 days to stave off cytokine storm. Hence this study was undertaken with the aim to study the relationship between initiation of steroid therapy and clinical outcome in hospitalized COVID-19 patients. The data for this study was collected from the medical records of patients diagnosed with COVID-19 in a tertiary care hospital. Evaluation of relationship between day of initiating steroid therapy and dose with the clinical outcome was done in terms of all-cause mortality, duration of hospital stay, requirement of assisted ventilation, requirement of ICU and requirement of oxygen therapy. Patients were categorized according to the day of initiating steroid after symptom onset or RTPCR or RAT positivity date, whichever was earlier in 4-7 days group, 8-10 days group and 11-14 days group. And according to dose given of methylprednisolone per day in 40 mg and 80 mg groups. All-cause mortality was significantly less in 8-10 days group (25.78%) compared to 4-7 days (38%) and 11-14 days group (39.68%) and significantly less in 40 mg group (26.67%) compared to 80 mg group (38.46%). Starting steroid between 8-10 days and in low dose (40 mg) is more beneficial in terms of all-cause mortality.Copyright © 2023, Global Research Online. All rights reserved.

Evaluation of Rapid Antigen Test as a Marker of SARS-CoV-2 Infectivity.

Background Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that emerged in late 2019 continues to spread globally. Reverse transcriptase polymerase chain reaction (RT-PCR), which is considered the gold standard for diagnosis, does not always indicate contagiousness. This study was planned to evaluate the performance of the rapid antigen test (RAT) with the duration of symptoms and the usefulness of these tests in determining the infectivity of patients by performing sub-genomic RT-PCR. Methodology This prospective, observational study was designed to compare the diagnostic value of the COVID-19 RAT (SD Biosensor, Korea) with COVID-19 RT-PCR (Thermo Fisher, USA) by serial testing of patients. To evaluate the infectivity of the virus, sub-genomic RT-PCR was performed on previous RAT and RT-PCR-positive samples. Results Of 200 patients, 102 were positive on both RT-PCR and RAT, with 87 patients serially followed and tested. The sensitivity and specificity of RAT were 92.73% and 93.33%, respectively, in symptomatic patients. The mean duration of RAT positivity was 9.1 days, and the mean duration of RT-PCR positivity was 12.6 days. Sub-genomic RT-PCR test was performed on samples that were reported to be positive by RAT, and 73/87 (83.9%) patients were found to be positive. RAT was positive in symptomatic patients whose duration of illness was less than 10 days or those with a cycle threshold value below 32. Conclusions Thus, RAT can be used as the marker of infectivity of SARS-CoV-2 in symptomatic patients, especially in healthcare workers.

Point-of-care salivary oxidative and renal functional markers to assess kidney function in reperfusion-induced acute kidney injury in male rats.

OBJECTIVES: Saliva is one of the most promising body fluids in the research of new biomarker for various diseases diagnosis. However, serial sampling in this condition is very dangerous and pose iatrogenic anemia with blood loss. This study was done to evaluate the cost-effectiveness of point-of-care salivary tests and identify the validity of salivary markers. METHODS: Rats were randomly assigned to four experimental groups: (1) control (2) IR-3 h (3) IR-6 h (4) IR-24 h. Both renal pedicles were occluded for 55 min and then were declamped to allow reperfusion for 3, 6 and 24 h in IR groups. After reperfusion, all rats received pilocarpine 1 mg/kg to collect saliva. Plasma samples were also collected. Renal parameters including Cr, uric acid, and urea, malondialdehyde (MDA) levels, Bax/Bcl2 ratio, nitrite/nitrate ratio, corticosterone levels and oxidant/antioxidant ratio were measured in both plasma and salivary samples. RESULTS: There were significant increased level of renal function parameters, MDA levels, Bax/Bcl2 ratio, nitrite/nitrate ratio and corticosterone in both saliva and plasma. The comparison of above parameters in both saliva and plasma showed significant correlation. CONCLUSIONS: This study demonstrated that concentrations of indices specifically renal functional parameters increase in saliva in the IR-induced kidney injury in male rats and result indicate the potential of saliva as a tool to monitoring AKI. Measurement of salivary parameters may can become reliable diagnostic tests for patients with AKI.

Comparison of Activity and Safety of DSPAα1 and Its N-Glycosylation Mutants.

DSPAα1 is a potent rude thrombolytic protein with high medicative value. DSPAα1 has two natural N-glycan sites (N153Q-S154-S155, N398Q-K399-T400) that may lead to immune responses when administered in vivo. We aimed to study the effect of its N-glycosylation sites on DSPAα1 in vitro and in vivo by mutating these N-glycosylation sites. In this experiment, four single mutants and one double mutant were predicted and expressed in Pichia pastoris. When the N398Q-K399-T400 site was mutated, the fibrinolytic activity of the mutant was reduced by 75%. When the N153Q-S154-S155 sites were inactivated as described above, the plasminogen activating activity of its mutant was reduced by 40%, and fibrin selectivity was significantly reduced by 21-fold. The introduction of N-glycosylation on N184-G185-A186T and K368N-S369-S370 also considerably reduced the activity and fibrin selectivity of DSPAα1. The pH tolerance and thermotolerance of all mutants did not change significantly. In vivo experiments also confirmed that N-glycosylation mutations can reduce the safety of DSPAα1, lead to prolonged bleeding time, non-physiological reduction of coagulation factor (α2-AP, PAI) concentration, and increase the risk of irregular bleeding. This study ultimately demonstrated the effect of N-glycosylation mutations on the activity and safety of DSPAα1.

SARS-CoV-2 Exposure in Norway Rats (Rattus norvegicus) from New York City.

Millions of Norway rats (Rattus norvegicus) inhabit New York City (NYC), presenting the potential for transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from humans to rats. We evaluated SARS-CoV-2 exposure among 79 rats captured from NYC during the fall of 2021. Our results showed that 13 of the 79 rats (16.5%) tested IgG- or IgM-positive, and partial SARS-CoV-2 genomes were recovered from all 4 rats that were qRT-PCR (reverse transcription-quantitative PCR)-positive. Genomic analyses suggest these viruses were associated with genetic lineage B, which was predominant in NYC in the spring of 2020 during the early pandemic period. To further investigate rat susceptibility to SARS-CoV-2 variants, we conducted a virus challenge study and showed that Alpha, Delta, and Omicron variants can cause infections in wild-type Sprague Dawley (SD) rats, including high replication levels in the upper and lower respiratory tracts and induction of both innate and adaptive immune responses. Additionally, the Delta variant resulted in the highest infectivity. In summary, our results indicate that rats are susceptible to infection with Alpha, Delta, and Omicron variants, and wild Norway rats in the NYC municipal sewer systems have been exposed to SARS-CoV-2. Our findings highlight the need for further monitoring of SARS-CoV-2 in urban rat populations and for evaluating the potential risk of secondary zoonotic transmission from these rat populations back to humans. IMPORTANCE The host tropism expansion of SARS-CoV-2 raises concern for the potential risk of reverse-zoonotic transmission of emerging variants into rodent species, including wild rat species. In this study, we present both genetic and serological evidence for SARS-CoV-2 exposure to the New York City wild rat population, and these viruses may be linked to the viruses that were circulating during the early stages of the pandemic. We also demonstrated that rats are susceptible to additional variants (i.e., Alpha, Delta, and Omicron) that have been predominant in humans and that susceptibility to infection varies by variant. Our findings highlight the reverse zoonosis of SARS-CoV-2 to urban rats and the need for further monitoring of SARS-CoV-2 in rat populations for potential secondary zoonotic transmission to humans.

The effect of vitamin C supplementation on favipiravir-induced oxidative stress and proinflammatory damage in livers and kidneys of rats.

Favipiravir (FPV), an effective antiviral agent, is a drug used to treat influenza and COVID-19 by inhibiting the RNA-dependent RNA polymerase (RdRp) of RNA viruses. FPV has the potential to increase oxidative stress and organ damage. The purpose of this study was to demonstrate the oxidative stress and inflammation caused by FPV in the liver and kidneys of rats, as well as to investigate the curative effects of vitamin C (VitC). A total of 40 Sprague-Dawley male rats were randomly and equally divided into the following five groups: 1st; Control, 2nd; FPV = 20 mg/kg, 3rd; FPV = 100 mg/kg, 4th; FPV = 20 mg/kg + VitC (150 mg/kg), and 5th; FPV = 100 mg/kg + VitC (150 mg/kg) groups. Rats were given either FPV (orally) or FPV plus VitC (intramuscular) for 14 days. Rat blood, liver, and kidney samples were collected at 15 days to be analyzed for oxidative and histological changes. FPV administration resulted in an increase in proinflammatory cytokines (TNF-α and IL-6) in the liver and kidney, as well as oxidative and histopathologic damage. FPV increased TBARS levels significantly (p < 0.05) and decreased GSH and CAT levels in liver and kidney tissues but had no effect on SOD activity. VitC supplementation significantly reduced TNF-a, IL-6, and TBARS levels while increasing GSH and CAT levels (p < 0.05). Furthermore, VitC significantly attenuated FPV-induced histopathological alterations associated with oxidative stress and inflammation in the liver and kidney tissues (p < 0.05). FPV caused liver and kidney damage in rats. In contrast, co-administration of FPV with VitC improved FPV-induced oxidative, pro-inflammatory, and histopathological changes.

In Vitro Pharmacokinetic Behavior of Antiviral 3-Amidinophenylalanine Derivatives in Rat, Dog and Monkey Hepatocytes.

Type II transmembrane serine proteases represent pharmacological targets for blocking entry and spread of influenza or coronaviruses. In this study, the depletion rates of the 3-amidinophenylalanine (3-APhA)-derived matriptase/TMPRSS2 inhibitors MI-463, MI-472, MI-485 or MI-1900 were determined by LC-MS/MS measurements over a period of 300 min using suspensions of rat, dog and cynomolgus monkey primary hepatocytes. From these in vitro pharmacokinetic (PK) experiments, intrinsic clearance values (Clint) were evaluated, and in vivo pharmacokinetic parameters (hepatic clearance, hepatic extraction ratio and bioavailability) were predicted. It was found that rat hepatocytes were the most active in the metabolism of 3-APhA derivatives (Clint 31.9-37.8 mL/min/kg), whereas dog and monkey cells displayed somewhat lower clearance of these compounds (Clint 6.6-26.7 mL/min/kg). These data support elucidation of important PK properties of anti-TMPRSS2/anti-matriptase 3-APhAs using mammalian hepatocyte models and thus contribute to the optimization of lead compounds.