The involvement of NF-kappaB binding activity is known to be important in the mechanism of acute liver injury and in the induction of cyclooxygenase (COX-2). This study was performed to evaluate NF-kappaB binding activity and the expression of COX-2 in chronic liver injury induced by carbon tetrachloride (betaCCI(4)). Liver tissues from Sprague - Dawley rats were collected at 1, 3, 5, and 7th week after intraperitoneal injection of 0.1 mL of betaCCI(4)/100 g body weight twice a week. Reactive oxy-gen species (ROS) were measured in the postmitochondrial fraction by dichlorofluorescein formation with a fluorescent probe. An electrophoretic mobility shift assay was performed for NF-kappaB binding activity. Western blot was performed to measure the level of COX-1, COX-2, p65, p50, and I B proteins. ROS and NF-kappaB activity increased during the CCl4-induced chronic liver injury. The expression of nuclear p65 protein and p50 protein increased compared with that of the control, while the cytoplasmic I B protein decreased as the inflammation persisted. The expression of COX-2 in betaCCI(4)-treated rat liver increased compared with that of the control. It could be suggested that ROS produced by betaCCI(4) treatment increased NF-kappaB binding activity and thereby COX-2 expression, and these might be implicated in the progress of chronic liver damage.
Animals ; Biological Transport ; Carbon Tetrachloride/administration & dosage/*adverse effects ; Carbon Tetrachloride Poisoning/*metabolism/pathology ; Cell Nucleus/metabolism ; Cyclooxygenase 1 ; Cyclooxygenase 2 ; Cytoplasm/metabolism ; I-kappa B Proteins/biosynthesis ; Isoenzymes/*biosynthesis ; Liver/drug effects/*injuries/pathology ; Membrane Proteins ; NF-kappa B/antagonists & inhibitors/*metabolism ; NF-kappa B p50 Subunit ; Prostaglandin-Endoperoxide Synthases/*biosynthesis ; Protein Binding ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; Transcription Factor RelA

Background: Following the coronavirus disease 2019 (COVID-19) outbreak in Wuhan, China, a total of 637 patients had been diagnosed with the disease in Seoul as of May 2, 2020. Our study aimed to describe the impact of the 3T strategies (preemptive testing, prompt tracing and proper treatment) on the epidemiological characteristics of COVID-19 in Seoul. Methods: The descriptive and explanatory analysis was carried out on critical indicators such as epidemiological characteristics and key duration of patient status change from January 24 to May 2 in Seoul before and after preemptive testing for patients under investigation associated with COVID-19 clusters. Results: Preemptive testing increased the positive test rate (3.9% to 4.2%), an asymptomatic case at diagnosis (16.9% to 30.6%), and reduced the time from symptom onset to quarantine (4.0 to 3.0 days). Prompt tracing decreased unknown sources of infection (6.9% to 2.8%), the mean number of contacts (32.2 to 23.6), and the time-varying reproduction number R(t) (1.3 to 0.6). With proper treatment, only 2 cases of mortality occurred, resulting in a fatality rate of just 0.3%. Conclusion In the first wave of the COVID-19 pandemic lasting 100 days, the effect of the 3T strategies flattened the curve and decreased the time during which infected individuals were contagious, thereby lowering the R(t) below 1 in Seoul.