ABSTRACT
Objective@#To investigate the first family cluster of COVID-19 in Lanzhou, so as to provide basis for improving the COVID-19 outbreak prevention capacity. @*Methods @# On January 23, the First Hospital of Lanzhou University reported two suspected cases of COVID-19.According to the COVID-19 Epidemiological Investigation Plan ( second edition ) , general information, disease diagnosis and treatment, clinical symptoms, laboratory test results, household environment, exposure history and close contacts were collected to figure out the source of infection and routes of transmission. @*Results@#This family cluster lasted 29 days, from January 23 to February 21, reporting nine confirmed cases ( one death ) and one asymptomatic case. There were three imported cases from Wuhan, who were the source of the cluster; and seven secondary cases, who all had close contact with the imported cases during daily life or through having dinners. The secondary attack rate was 41.18% ( 7/17 ) . Among 9 confirmed cases, the incubation period ranged from four to ten days, with a median of nine days. Except for seven secondary cases, 24 close contacts were found and detected negative in the nucleic acid tests.@*Conclusions@#The first family cluster of COVID-19 in Lanzhou is caused by the imported cases from Wuhan. All the secondary cases have had dinners and/or had contact with the imported cases, thus they are infected through respiratory droplets and close contact.
ABSTRACT
Propofol is known to cause vasorelaxation of several systemic vascular beds. However, its effect on the pulmonary vasculature remains controversial. In the present study, we investigated the effects of propofol on human pulmonary arteries obtained from patients who had undergone surgery. Arterial rings were mounted in a Multi-Myograph system for measurement of isometric forces. U46619 was used to induce sustained contraction of the intrapulmonary arteries, and propofol was then applied (in increments from 10–300 µM). Arteries denuded of endothelium, preincubated or not with indomethacin, were used to investigate the effects of propofol on isolated arteries. Propofol exhibited a bifunctional effect on isolated human pulmonary arteries contracted by U46619, evoking constriction at low concentrations (10–100 µM) followed by secondary relaxation (at 100–300 µM). The extent of constriction induced by propofol was higher in an endothelium-denuded group than in an endothelium-intact group. Preincubation with indomethacin abolished constriction and potentiated relaxation. The maximal relaxation was greater in the endothelium-intact than the endothelium-denuded group. Propofol also suppressed CaCl₂-induced constriction in the 60 mM K⁺-containing Ca²⁺-free solution in a dose-dependent manner. Fluorescent imaging of Ca²⁺ using fluo-4 showed that a 10 min incubation with propofol (10–300 µM) inhibited the Ca²⁺ influx into human pulmonary arterial smooth muscle cells induced by a 60 mM K⁺-containing Ca²⁺-free solution. In conclusion, propofol-induced arterial constriction appears to involve prostaglandin production by cyclooxygenase in pulmonary artery smooth muscle cells and the relaxation depends in part on endothelial function, principally on the inhibition of calcium influx through L-type voltage-operated calcium channels.