ABSTRACT Coronavirus Disease 2019 (COVID-19) has rapidly spread worldwide. Numerous studies have shown its typical and atypical CT findings. We report one COVID-19 patient who presented with a transient pneumothorax, spontaneous pneumomediastinum (SP), as well as subcutaneous emphysema during hospitalization. Chest CT andclinical findings were discussed, and a literature review is presented. The probable cause of SP in COVID-19 was alveolar damage. Once pneumothorax and SP were present, the patient should be carefully monitored to prevent respiratory deterioration, especially when lung lesions are severe.

Background Triterpenoids are multifunctional secondary metabolites in plants. But little information is available concerning the actual yield, optimal extraction method and pharmacologic activity with regard to triterpenoids from Jatropha curcas leaves (TJL). Hence, response surface methodology (RSM) was used to optimize the extraction parameters. The effects of three independent variables, namely liquid-to-solid ratio, ethanol concentration and extraction time on TJL yield were investigated. TJL obtained by silica column chromatography was tested against bacterial and fungal species relevant to oral disease and wounds through broth microdilution. Antioxidant activity was assessed using the 2,2-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. Results A second order polynomial model produced a satisfactory fitting of the experimental data with regard to TJL yield (R2 = 0.983, P < 0.01). The optimum extraction conditions were 16 mL/g (liquid-to-solid ratio), 70% (ethanol concentration) and 50 min (extraction time). Predicted values agreed well with the experimental values. TJL had extraordinarily strong antibacterial and antifungal activities (24.42 µg/mL < MIC < 195.31 µg/mL) against all the tested human pathogens except Bacteroides vulgatus (390.62 µg/mL) and Bacteroides stercoris (781.25 µg/mL). The DPPH and ABTS assays revealed a moderate antioxidant activity of TJL compared with ascorbic acid. Conclusion These results provided reliable scientific basis for further investigation of triterpenoids from J. curcas.

Background Jatropha curcas is a rich reservoir of pharmaceutically active terpenoids. More than 25 terpenoids have been isolated from this plant, and their activities are anti-bacterial, anti-fungal, anti-cancer, insecticidal, rodenticidal, cytotoxic and molluscicidal. But not much is known about the pathway involved in the biosynthesis of terpenoids. The present investigation describes the cloning, characterization and subcellular localization of isopentenyl diphosphate isomerase (IPI) gene from J. curcas. IPI is one of the rate limiting enzymes in the biosynthesis of terpenoids, catalyzing the crucial interconversion of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Results A full-length JcIPI cDNA consisting of 1355 bp was cloned. It encoded a protein of 305 amino acids. Analysis of deduced amino acid sequence predicted the presence of conserved active sites, metal binding sites and the NUDIX motif, which were consistent with other IPIs. Phylogenetic analysis indicated a significant evolutionary relatedness with Ricinus communis. Southern blot analysis showed the presence of an IPI multigene family in J. curcas. Comparative expression analysis of tissue specific JcIPI demonstrated the highest transcript level in flowers. Abiotic factors could induce the expression of JcIPI. Subcellular distribution showed that JcIPI was localized in chloroplasts. Conclusion This is the first report of cloning and characterization of IPI from J. curcas. Our study will be of significant interest to understanding the regulatory role of IPI in the biosynthesis of terpenoids, although its function still needs further confirmation.

MHC class I proteins mediate functions in anti-pathogen defense. MHC diversity has already been investigated by many studies in model avian species, but here we chose the bar-headed goose, a worldwide migrant bird, as a non-model avian species. Sequences from exons encoding the peptide-binding region (PBR) of MHC class I molecules were isolated from liver genomic DNA, to investigate variation in these genes. These are the first MHC class I partial sequences of the bar-headed goose to be reported. A preliminary analysis suggests the presence of at least four MHC class I genes, which share great similarity with those of the goose and duck. A phylogenetic analysis of bar-headed goose, goose and duck MHC class I sequences using the NJ method supports the idea that they all cluster within the anseriforms clade.