ABSTRACT
A global pandemic of Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is ongoing spread. It remains unclear whether the convalescing patients have a risk of reinfection. Rhesus macaques were rechallenged with SARS-CoV-2 during an early recovery phase from initial infection characterized by weight loss, interstitial pneumonia and systemic viral dissemination mainly in respiratory and gastrointestinal tracts. The monkeys rechallenged with the identical SARS-CoV-2 strain have failed to produce detectable viral dissemination, clinical manifestations and histopathological changes. A notably enhanced neutralizing antibody response might contribute the protection of rhesus macaques from the reinfection by SARS-CoV-2. Our results indicated that primary SARS-CoV-2 infection protects from subsequent reinfection. One Sentence SummaryNeutralizing antibodies against SARS-CoV-2 might protect rhesus macaques which have undergone an initial infection from reinfection during early recovery days.
ABSTRACT
The outbreak of Corona Virus Disease 2019 caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) is highly transmitted. The potential extra-respiratory transmission routes remain uncertain. Five rhesus macaques were inoculated with 1x106 TCID50 of SARS-CoV-2 via conjunctival (CJ), intratracheal (IT), and intragastric (IG) routes, respectively. Remarkably, the CJ inoculated-macaques developed mild interstitial pneumonia and viral load was detectable in the conjunctival swabs at 1 days post-inoculation (dpi). Only via IT inoculation, viral load was detected in the anal swab at 1-7 dpi and macaque showed weight loss. However, viral load was undetectable after IG inoculation. Comparatively, viral load was higher in the nasolacrimal system but lesions of lung were relatively mild and local via CJ inoculation compared with that via IT inoculation, demonstrating distinct characteristics of virus dispersion. Both the two routes affected the alimentary tract. Therefore the clinicians need to protect eye while working with patients.
ABSTRACT
Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.
ABSTRACT
Objective To explore the effect of age on the fracture healing through bioinformatical analysis of gene ex?pression data in GEO, and to screen critical molecular targets and pathways involved in this process. Methods Through R programming language, we identified different expressed genes between 26/52 week old rats and 6 week old rats in every time points of the experiment (No fracture;3 days, 1 week, 2 weeks, 4 weeks and 6 weeks after fracture). By comparison of these different expressed genes, those genes that may contribute to fracture healing were identified. Function annotation was conducted based on DAVID database and PPI network that was constructed via STRING database. Results Compared with 6 week old rat, 52 week old rat show more different genes at 2, 4 and 6 weeks after fracture as well as more than intact rats. At the time point of 6 weeks after fracture, 26 week old rat present 4 different genes while 52 week old rat present 99 differ?ent genes compared with 6 week old rat. We totally found 99 genes that might play important roles in the process of fracture healing. These genes involved in biological process related to bone healing, immune, inflammatory and etc. Also, two screened gene enriched KEGG pathways were identified: ECM-receptor interaction and Arachidonic acid metabolism. Through the analysis of PPI network, Pcna, Fn1, Casp3 and etc, who present high density connectivity in PPI network, were screened out. Conclusion Pcna, Casp3 and Fn1 and etc might play important roles in fracture healing through affecting ECM-receptor interaction and Arachidonic acid metabolism.
ABSTRACT
Objective To explore the pathogenesis of juvenile idiopathic arthritis (JIA) and its potential molecular targets.Methods Gene microarray data about JIA was downloaded from Gene Expression Omnibus (GEO) in NCBI.Different expressed genes were identified through bioconductor packages in R programing.The causal genes from the different expressed genes were optimized and replenished by GLAD4U and ToppGene.Functional annotation information of causal genes was carried out by DAVID.Results List of causal genes was obtained as well as their enriched function.Some potential pathways such as Cytokine-cytokine receptor interaction,Jak-STAT signaling pathway,which may be important in the progression of JIA were screened.Conclusions The pathogenesis of JIA,as well as its potential causal genes,can be captured through bioinformatics methods,so it may be used as time and cost saving method in experimental study and clinical application.
ABSTRACT
Objective An experiment study on the femoral head plastic operation to prevent and treat aseptic necrosis of the femoral head. Methods 60 Chinese white rabbits were equally random divided into 4 groups. The four groups except A group were made a globose defect and filled with 95% alcohol tampon for 30 minutes. The B group was natural repair group. The C group was filled with bone cement after being made defect. The D group was filled with bone cement added barium sulfate agent after being made defect. After 12 weeks, all rabbits in four groups were killed. The specimens were random divided into two parts. The articular cartilage was observed and measured immediately. The other specimen was determined with histological examination and extreme anti-pressure rigidity test . Result The femoral heads of bone cement group and the femoral heads of contrast agent bone cement group kept their outline all the time through the articular cartilage observation. After 12 weeks the cartilage thickness of natural repair group (511.74 ± 69.00) was thinner than the other three groups [ control group ( A group ) (511.74 ± 69 00 );Bone cement group ( C group) (468. 36 ± 82. 99 ); Bone cement group contrast agent ( D group ) ( 515.61 ±64. 65 ) ], and it had significant difference ( P < 0. 05, P < 0. 01 ). The rigidity of natural repair group [ (676. 57 ±50. 92) N/mm] had significant difference with that of the other three groups[ A group( 884. 66±52. 29)N/mm;C group(1178.40 ± 170.45) N/mm;D group(928.60 ± 104.42) N/mm] ( P <0.05, P<0. 01 ). Conclusions Femoral head plastic operation was simple and it could release pain. And femoral head outline could be kept integrity. It would be a new operation which was used to treat young patients in Ficat Ⅱ～Ⅲ period to postpone or substitute total hip replacement.