Compared with the cases in Wuhan, 80 imported cases of COVID-19 in Jiangsu Province exhibited mild or moderate symptoms and no obvious gender susceptivity, lower proportion of liver dysfunction and abnormal CT imaging and higher frequency nucleic acid detection. AbstractBackground. We aimed to report the clinical characteristics of imported coronavirus disease-19 in Jiangsu Province. Methods.We retrospectively investigated the clinical, imaging, and laboratory characteristics of confirmed cases of COVID-19 with WHO interim guidance in three Grade ⅢA hospitals of Jiangsu from Jan 22 to Feb 14, 2020. Real time RT-PCR was used to detect the new coronavirus in respiratory samples. Results.Of the 80 patients infected with COVID-19, 41 patients were female, with a median age of 46.1 years. Except for 3 severe patients, the rest of the 77 patients exhibited mild or moderate symptoms. 9 patients were unconfirmed until a third-time nucleic acid test. 38 cases had a history of chronic diseases. The main clinical manifestations of the patients were fever and cough, which accounted for 63 cases (78.75%) and 51 cases (-63.75%) respectively.Only 3 patients (3.75%) showed liver dysfunction. Imaging examination showed that 55 patients (-68.75%) showed abnormal, 25 cases (31.25%) had no abnormal density shadow in the parenchyma of both lungs. Up to now, 21 cases were discharged from the hospital, and no patient died. The average length of stay for discharged patients was 8 days. Conclusions.Compared with the cases in Wuhan, the cases in Jiangsu exhibited mild or moderate symptoms and no obvious gender susceptivity. The proportion of patients having liver dysfunction and abnormal CT imaging was relatively lower than that of Wuhan.Notably, infected patients may be falsely excluded based on two consecutively negative respiratory pathogenic nucleic acid test results.

To facilitate the construction of large genomewide libraries of small interfering RNAs (siRNAs), we have developed a dual promoter system (pDual) in which a synthetic DNA encoding a genespecific siRNA sequence is inserted between two different opposing polymerase III promoters, the mouse U6 and human H1 promoters. Upon transfection into mammalian cells, the sense and antisense strands of the duplex are transcribed by these two opposing promoters from the same template, resulting in a siRNA duplex with a uridine overhang on each 3 terminus. A single-step PCR protocol has been developed by using this dual promoter system that allows the production of siRNA expression cassettes in a high-throughput manner. We have shown that siRNAs transcribed by either the dual promoter vector or siRNA expression cassettes can induce strong and gene-specific suppression of both endogenous genes and ectopically expressed genes in mammalian cells. Furthermore, we have constructed an arrayed siRNA expression cassette library that targets >8,000 genes with two siRNA sequences per gene. A high-throughput screen of this library has revealed both known and unique genes involved in the NF-B signaling pathway. RNA interference (RNAi) is an evolutionarily conserved phenomenon in which gene expression is suppressed by the introduction of homologous double-stranded RNAs (dsRNAs). After dsRNA molecules are delivered to the cytoplasm of a cell, they are cleaved by the RNase III-like enzyme, Dicer, to 21-to 23-nt small interfering RNAs (siRNAs) (1). These siRNAs are then incorporated into a protein complex, the RNA-induced silence complex (RISC). The antisense strand of the duplex siRNA guides the RISC to the homologous mRNA, where the RISC-associated endoribonuclease cleaves the target mRNA, resulting in silencing of the target gene (2). RNAi has been successfully used to suppress gene expression in a variety of organisms including zebrafish, Caenorhabditis elegans, Drosophila, planaria, mice, and mammalian cells (3,4). In C. elegans and Drosophila, RNAi is typically induced by the introduction of a long dsRNA (up to 1-2 kb) produced by in vitro transcription. This simple approach cannot be used in mammalian cells, where introduction of long dsRNA elicits a strong antiviral response that obscures any gene-specific silencing effect. Much of this response is caused by activation of the dsRNA-dependent protein kinase PKR, which phosphorylates and inactivates the translation initiation factor eIF2a (5, 6). However, introduction of 21-nt siRNAs into mammalian cells does not stimulate the antiviral response in mammalian cells and can effectively target specific mRNAs, resulting in gene silencing (7).Short siRNA molecules can be prepared by chemical synthesis or in vitro transcription. Alternatively, they can be transcribed in vivo by using siRNA expression vectors with a RNA polymerase (pol) III promoter (including U6, human H1, and tRNA promoters) (8, 9), or a pol II promoter with a minimal poly(A) signal sequence (10). Tissue-specific pol II promot...

Since the first reports on isolation of pluripotent mouse embryonic stem (ES) cells 3 decades ago, there have been numerous attempts to derive ES cell lines from commercially important livestock species with limited success. The recent discovery that ectopic expression of a handful of stem cell-related genes was capable of inducing pluripotency in rodents and primates provided a novel approach to derivation of pluripotent stem cell lines. We used this approach in cattle and demonstrated that the ectopic expression of POU5F1 (also known as Oct4), SOX2, KLF4, and c-MYC alone was not sufficient for stable induction of pluripotency in bovine adult fibroblasts and that the additional expression of NANOG to the reprogramming cocktail was essential for the generation of stable bovine (b) induced pluripotent stem (iPS) cells. The resulting biPS cells were characterized by reverse-transcription PCR for a panel of ES marker genes. Immunocytochemical localization of POU5F1, SSEA-1, SSEA-4, and colorimetric alkaline phosphatase activity was measured in the iPS clones. The differentiation potential of the biPS cells was determined in vitro by expression of differentiation markers in embryoid bodies. Injection of biPS into immunocompromised mice resulted in teratomas containing cell types of the 3 germ lineages. This study reports the first generation of bovine induced pluripotent cell lines and paves the way for the use of biPS cells for biotechnological and agricultural purposes.