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1.
Front Cardiovasc Med ; 10: 1271608, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38179501

RESUMO

Objectives: Our study was to evaluate the effect of Qishen Yiqi Dropping Pills(QSYQ) on the prognosis of chronic ischemic heart failure(CIHF) and its safety. Methods: Databases including CNKI, Wanfang, VIP, CBM, PubMed, Web of Science, The Cochrane Library and EMbase were searched from their inception to April 2023 to screen relevant randomized controlled trials (RCTs). Primary indicators included readmission rates, rates of major adverse cardiovascular events (MACE), and all-cause mortality rates. The quality of the literature was assessed according to the Cochrane Reviewers' Handbook 5.0 and the Modified Jadad Scale (with a score of 4-7 rated as high quality). Meta-analysis was performed using the meta-package created by R software version 4.2.3, continuous data were compared using SMDs, and dichotomous and ordered data were compared using ORs; and the I2 test was used to assess the heterogeneity. Results: Fifty-nine studies out of 1,745 publications were finally included, totalling 6,248 patients. Most studies were poorly designed and had some publication bias, with only 26 high-quality papers (Jadad score ≥4). Meta-analysis showed that the combined application of QSYQ was able to reduce the readmission rate [OR = 0.42, 95% CI (0.33, 0.53), P < 0.001], all-cause mortality rate [OR = 0.43, 95% CI (0.27, 0.68), P < 0.001], and the incidence of MACE [OR = 0.42, 95% CI (0.31, 0.56), P < 0.001]. Also, the treatment method can improve clinical effectiveness [OR = 2.25, 95% CI (1.97, 2.58), P < 0.001], increase 6-min walking distance (6MWD) [SMD = 1.87, 95% CI (1.33, 2.41), P < 0.0001] and left ventricular ejection fraction (LVEF) [SMD = 1.08, 95% CI (0.83, 1.33), P < 0.0001], and decrease the Minnesota Living with Heart Failure Questionnaire (MLHFQ) scores [SMD = -2.03, 95% CI (-3.0, -1.07), P < 0.0001], BNP levels [SMD = -2.07, 95% CI (-2.81, -1.33), P < 0.0001] and NT-ProBNP levels [SMD = -2.77, 95% CI (-4.90, -0.63), P < 0.05]. A total of 21 studies (n = 2,742) evaluated their adverse effects, of which 13 studies reported no adverse effects and 8 studies reported minor adverse effects. Conclusion: Our results suggest that the combined application of QSYQ can further improve patients' cardiac function and exercise tolerance, improve their quality of life, and ultimately improve patients' prognosis with a favorable safety profile. Nonetheless, limited by the quality and high heterogeneity of the literature, we must be conservative and cautious about the present results. Systematic Review Registration: PROSPERO (CRD42023449251).

2.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-995299

RESUMO

Objective:To investigate the appropriate pretreatment methods for single cell RNA sequencing of airway aspirate cells.Methods:Four fresh airway aspirate specimens were collected from four patients with acute respiratory tract infections. These specimens were digested with airway aspirate digester and prepared into single cell suspension. The cells were used for library construction directly (DE), or fixed with 10×Genomics Chromium Next GEM Single Cell Fixed RNA Sample Preparation Kit and then mixed to construct the library (DF), or cryopreserved, thawed, fixed (FF) before mixed to construct the library. All three methods were treated with oil emulsion using 10 4 cells and subjected to single-cell sequencing using the 10×Genomics platform. The number of obtained cells, data quality, annotated cell types and expression of marker genes were analyzed. Differences in the expression of highly variable genes (HVGs) of the same cell subsets obtained by the three pretreatment methods were compared using Pearson correlation. Expression of the differentially expressed genes in the same cell subpopulation obtained by different pretreatment methods was also compared. The correlation of the expression of differentially expressed genes between the same cell subsets obtained by the three pretreatment methods was analyzed by Pearson correlation. Results:The median numbers of single cells obtained using DE, FF and DF methods were 2 733, 1 140 and 5 897 ( P>0.05). The unique molecular identifiers were higher than 500. The median numbers of genes obtained using the three methods were 801, 887 and 1 259 ( P>0.05). The cells with novelty score over 0.8 accounted for 99%, 87% and 93%, respectively. There were nine cell subsets obtained by the three methods, including squamous cells, secretory cells, ciliated cells, T cells, B cells, macrophages, plasma cells and neutrophils. DF and FF methods could obtain more basal cells with specific high expression of keratin 5 than DE method. The differentially expressed and highly variable genes in the same cell subsets obtained by the three pretreatment methods showed high consistency in their expression with a significant correlation ( P<0.001). Conclusions:Under the same sequencing data volume, the quality of data obtained from fixed airway aspirate single-cell suspensions using the method of probe hybridization and transcriptome sequencing was comparable to that obtained directly from fresh cells. This method was more suitable for the pretreatment of clinical samples used for single-cell RNA sequencing.

3.
Protein & Cell ; (12): 28-36, 2023.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-971610

RESUMO

The emerging of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused COVID-19 pandemic. The first case of COVID-19 was reported at early December in 2019 in Wuhan City, China. To examine specific antibodies against SARS-CoV-2 in biological samples before December 2019 would give clues when the epidemic of SARS-CoV-2 might start to circulate in populations. We obtained all 88,517 plasmas from 76,844 blood donors in Wuhan between 1 September and 31 December 2019. We first evaluated the pan-immunoglobin (pan-Ig) against SARS-CoV-2 in 43,850 samples from 32,484 blood donors with suitable sample quality and enough volume. Two hundred and sixty-four samples from 213 donors were pan-Ig reactive, then further tested IgG and IgM, and validated by neutralizing antibodies against SARS-CoV-2. Two hundred and thirteen samples (from 175 donors) were only pan-Ig reactive, 8 (from 4 donors) were pan-Ig and IgG reactive, and 43 (from 34 donors) were pan-Ig and IgM reactive. Microneutralization assay showed all negative results. In addition, 213 screened reactive donors were analyzed and did not show obviously temporal or regional tendency, but the distribution of age showed a difference compared with all tested donors. Then we reviewed SARS-CoV-2 antibody results from these donors who donated several times from September 2019 to June 2020, partly tested in a previous published study, no one was found a significant increase in S/CO of antibodies against SARS-CoV-2. Our findings showed no SARS-CoV-2-specific antibodies existing among blood donors in Wuhan, China before 2020, indicating no evidence of transmission of COVID-19 before December 2019 in Wuhan, China.


Assuntos
Humanos , Anticorpos Antivirais , Doadores de Sangue , China/epidemiologia , COVID-19/imunologia , Imunoglobulina G , Imunoglobulina M , Pandemias , SARS-CoV-2
4.
China Pharmacy ; (12): 413-418, 2022.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-920456

RESUMO

OBJECTIVE To prepare Leonurine hydrochloride tablets and evaluate the quality. METHODS The wet granulation technology was adopted ;leonurine hydrochloride was used as the crude drug ,and the types of fillers ,disintegrants,binders and lubricants were screened by single-factor experiments. Combined with orthogonal experiments ,using the cumulative dissolution rate within 15 minutes(using water as dissolution media )as index ,the proportion of disintegrants ,the mass fraction of binder solution,and the proportion of lubricants were screened and verified. The in vitro dissolution behavior of the prepared Leonurine hydrochloride tablets (dissolution media were hydrochloric acid solution of pH 1.2,acetic acid-sodium acetate solution of pH 4.5, phosphate buffer solution of pH 6.8,water),tablet appearance ,hardness,friability and content uniformity were tested according to the general principles in 2020 edition of Chinese Pharmacopoeia (part Ⅳ). RESULTS The optimal formulation of Leonurine hydrochloride tablets included leonurine hydrochloride crude drug of 500 mg,dextrin of 9 250 mg,crosslinking polyving y- pyrrolidone of 200 mg,magnesium stearate of 50 mg,1% hydroxypropyl methyl cellulose solution of 4 mL. The average 15-minute cumulative dissolution rate of the three batches of tablets was 81.25%(RSD=1.12%,n=3). In above 4 dissolution media,the dissolution equilibrium of prepared tablets could be reached within 30 minutes,and the cumulative dissolution rates exceeded 85%. The prepared tablets had uniform beige in color ,smooth surface ,complete edge ,no mottle ,spot,foreign matter , etc.,hardness of 57.3 N(n=6),weight loss rate of 0.15%. The content uniformity was in accordance with relevant provisions in 2020 edition of Chinese Pharmacopoeia (part Ⅳ). CONCLUSIONS Leonurine hydrochloride tablets are successfully prepared , and the quality comply with relevant regulations.

5.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-930430

RESUMO

Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.

6.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-441316

RESUMO

RNA viruses including SARS-CoV-2, Ebola virus (EBOV), and Zika virus (ZIKV) constitute a major threat to global public health and society. The interactions between viral genomes and host proteins are essential in the life cycle of RNA viruses and thus provide targets for drug development. However, viral RNA-host protein interactions have remained poorly characterized. Here we applied ChIRP-MS to profile the interactomes of human proteins and the RNA genomes of SARS-CoV-2, EBOV, and ZIKV in infected cells. Integrated interactome analyses revealed interaction patterns that reflect both common and virus-specific host responses, and enabled rapid drug screening to target the vulnerable host factors. We identified Enasidenib as a SARS-CoV-2 specific antiviral agent, and Trifluoperazine and Cepharanthine as broad spectrum antivirals against all three RNA viruses. One Sentence SummaryInteractome analyses of host proteins and the SARS-CoV-2, EBOV, and ZIKV RNA genomes unveil viral biology and drug targets.

7.
Acta Pharmaceutica Sinica B ; (6): 1555-1567, 2021.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-888804

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become one major threat to human population health. The RNA-dependent RNA polymerase (RdRp) presents an ideal target of antivirals, whereas nucleoside analogs inhibitor is hindered by the proofreading activity of coronavirus. Herein, we report that corilagin (RAI-S-37) as a non-nucleoside inhibitor of SARS-CoV-2 RdRp, binds directly to RdRp, effectively inhibits the polymerase activity in both cell-free and cell-based assays, fully resists the proofreading activity and potently inhibits SARS-CoV-2 infection with a low 50% effective concentration (EC

8.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-930354

RESUMO

Respiratory viruses can cause a variety of serious respiratory infections and diseases of tissues and organs outside the respiratory tract, raising a potentially severe threat to the society.Virus replication and survival rely on the internal mechanism of host cells, and the latter also produce a variety of restriction factors that target viral invasion, genome transcription and replication, and assembly and release to block viral infection.Herein, this study reviewed the research progress of the antiviral effects of the host restriction factors of common respiratory viruses and their underlying mechanisms.

9.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20193904

RESUMO

SARS-CoV-2 is the seventh coronavirus known to infect humans and has caused an emerging and rapidly evolving global pandemic (COVID-19) with significant morbidity and mortality. To meet the urgent and massive demand for the screening and diagnosis of infected individuals, many in vitro diagnostic assays using nucleic acid tests (NATs) have been urgently authorized by regulators worldwide. The limit of detection (LoD) is a crucial feature for a diagnostic assay to detect SARS-CoV-2 in clinical samples, and a reference standard with a well-characterized concentration or titer is of the utmost importance for LoD studies. Although several reference standards of plasmids or synthetic RNA carrying specific genomic regions of SARS-CoV-2 have already been announced, a reference standard for inactivated virus particles with accurate concentration is still needed to evaluate the complete procedure including nucleic acid extraction and to accommodate customized primer-probe sets targeting different genome sequences. Here, we performed a collaborative study to estimate the NAT-detectable units as viral genomic equivalent quantity (GEQ) of an inactivated whole-virus SARS-CoV-2 reference standard candidate using digital PCR (dPCR) on multiple commercialized platforms. The median of the quantification results (4.6x105 {+/-} 6.5x104 GEQ/mL) was treated as the consensus true value of GEQ of virus particles in the reference standard. This reference standard was then used to challenge the LoDs of six officially approved diagnostic assays. Our study demonstrates that an inactivated whole virus quantified by dPCR can serve as a reference standard and provides a unified solution for assay development, quality control, and regulatory surveillance.

10.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20164780

RESUMO

OBJECTIVETo identify the anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) in coronavirus disease 2019 (COVID-19) and its relationship with the severity and clinical outcomes of COVID-19. DESIGNRetrospective cohort study. SETTINGThree hospitals in China. PARTICIPANTS274 adult inpatients diagnosed with COVID-19 according to the Protocol for Prevention and Control of COVID-19 (Edition 7) of China and confirmed by severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) RNA testing, were included from three hospitals from Wuhan, Harbin and Beijing, China from 1 December 2019 to 19 April 2020. The Biobank of Myositis Registry Department of Rheumatology, Peking Union Medical College Hospital, provided the plasma of five patients with anti-MDA5 Ab-related dermatomyositis as positive control group. Demographic, clinical and laboratory data were collected from medical records. The anti-MDA5 Ab was determined by an ELISA assay and was verified by immunoblotting analysis. MAIN OUTCOME MEASURESIn hospital death of all cause. RESULTSThe positive rate of anti-MDA5 Ab in patients with COVID-19 was 48.2% (132/274) and the anti-MDA5 Ab positive patients tended to represent with severe disease (88.6% vs 66.9%, P<0.0001). The titer of anti-MDA5 Ab was significantly elevated in the non-survivals (5.95{+/-}5.16 vs 8.22{+/-}6.64, P=0.030) and the positive rate was also higher than that in the survivals (23.5% vs 12.0%, P=0.012). Regarding to severe COVID-19 patients, we found that high titer of anti-MDA5 Ab ([≥]10.0 U/mL) was more prevalent in the non-survivals (31.2% vs 14.0%, P=0.006). Moreover, early profiling of anti-MDA5 Ab could distinguish severe patients from those with non-severe ones. CONCLUSIONAnti-MDA5 Ab was prevalent in the COVID-19 patients and high titer of this antibody is correlated with severe disease and unfavorable outcomes. Early screening and serially monitoring of anti-MDA5 Ab titer have the potential to predict the disease progression of COVID-19.

11.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20162206

RESUMO

BackgroundSince the end of 2019 to the present day, the outbreak of the coronavirus disease 2019 (COVID-19) has had an immense impact on China and on other countries worldwide. This outbreak represents a serious threat to the lives and health of people all around the world. The epidemic first broke out in Wuhan, where the Chinese government was unable to prevent the spread of the disease by implementing home quarantine measures. Mobile cabin hospitals were used to relieve pressure on hospitals due to the need for beds while also isolating the sources of the infection through a centralized quarantine and treatment of mild cases. MethodThis paper reviewed and summarized the treatment of patients with mild illness and symptoms during the period from the construction to the closing of the Hanyang Mobile Cabin Hospital in Wuhan, China, and presented the operational elements and possible improvements of running this hospital. ResultsMobile cabin hospitals helped China to curb the epidemic in only 2 incubation periods in 28 days.The basic conditions required for a normal operation of mobile cabin hospitals included the selection of the environment, medical staff to patient ratio, organizational structure, management model, admission criteria, treatment approaches, discharge process, livelihood guarantee, security, and other safeguarding measures. All of these components were performed carefully in Wuhan Hanyang Mobile Cabin Hospital, without medical staff being infected. ConclusionThe mobile cabin hospital compulsory quarantine for mild patients was an alternative method to combat COVID-19. It is hoped that the presented work in this manuscript can serve as a reference for the emergency prevention and control measures for global epidemic outbreaks.

12.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-192732

RESUMO

SUMMARYSARS-CoV-2 is an RNA virus of the Coronaviridae family that is the causal pathogen of the ongoing Coronavirus Disease 2019 pandemic. There are currently no antiviral drugs or vaccines to treat COVID-19, and the failure to identify effective interventions can be blamed on our incomplete understanding of the nature of this virus and its host cell infection process. Here, we experimentally determined structural maps of the SARS-CoV-2 RNA genome in infected human cells and also characterized in vitro refolded RNA structures for SARS-CoV-2 and 6 other coronaviruses. Our in vivo data confirms several structural elements predicted from theoretical analysis and goes much further in revealing many previously unknown structural features that functionally impact viral translation and discontinuous transcription in cells. Importantly, we harnessed our in vivo structure data alongside a deep-learning tool and accurately predicted several dozen functionally related host cell proteins that bind to the SARS-CoV-2 RNA genome, none of which were known previously. Thus, our in vivo structural study lays a foundation for coronavirus RNA biology and indicates promising directions for the rapid development of therapeutics to treat COVID-19.HIGHLIGHTSWe mapped the in vivo structure and built secondary structural models of the SARS-CoV-2 RNA genomeWe discovered functionally impactful structural features in the RNA genomes of multiple coronavirusesWe predicted and validated host cell proteins that bind to the SARS-CoV-2 RNA genome based on our in vivo RNA structural data using a deep-learning toolCompeting Interest StatementThe authors have declared no competing interest.View Full Text

13.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-188953

RESUMO

COVID-19 pandemic has infected millions of people with mortality exceeding 300,000. There is an urgent need to find therapeutic agents that can help clear the virus to prevent the severe disease and death. Identifying effective and safer drugs can provide with more options to treat the COVID-19 infections either alone or in combination. Here we performed a high throughput screen of approximately 1700 US FDA approved compounds to identify novel therapeutic agents that can effectively inhibit replication of coronaviruses including SARS-CoV-2. Our two-step screen first used a human coronavirus strain OC43 to identify compounds with anti-coronaviral activities. The effective compounds were then screened for their effectiveness in inhibiting SARS-CoV-2. These screens have identified 24 anti-SARS-CoV-2 drugs including previously reported compounds such as hydroxychloroquine, amlodipine, arbidol hydrochloride, tilorone 2HCl, dronedarone hydrochloride, and merfloquine hydrochloride. Five of the newly identified drugs had a safety index (cytotoxic/effective concentration) of >600, indicating wide therapeutic window compared to hydroxychloroquine which had safety index of 22 in similar experiments. Mechanistically, five of the effective compounds were found to block SARS-CoV-2 S protein-mediated cell fusion. These FDA approved compounds can provide much needed therapeutic options that we urgently need in the midst of the pandemic.Competing Interest StatementThe authors have declared no competing interest.View Full Text

14.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-189860

RESUMO

Quick and accurate detection of SARS-CoV-2 is critical for COVID-19 control. Dozens of real-time reverse transcription PCR (qRT-PCR) assays have been developed to meet the urgent need of COVID-19 control. However, methodological comparisons among the developed qRT-PCR assays are limited. In the present study, we evaluated the sensitivity, specificity, amplification efficiency, and linear detection ranges of three qRT-PCR assays, including the assays developed by our group (IPBCAMS), and the assays recommended by WHO and China CDC (CCDC). The three qRT-PCR assays exhibited similar sensitivities, with the limit of detection (LOD) at about 10 copies per reaction (except the ORF 1b gene assay in CCDC assays with a LOD at about 100 copies per reaction). No cross reaction with other respiratory viruses were observed in all of the three qRT-PCR assays. Wide linear detection ranges from 106 to 101 copies per reaction and acceptable reproducibility were obtained. By using 25 clinical specimens, the N gene assay of IPBCAMS assays and CCDC assays performed better (with detection rates of 92% and 100%, respectively) than that of the WHO assays (with a detection rate of 60%), and the ORF 1b gene assay in IPBCAMS assays performed better (with a detection rate of 64%) than those of the WHO assays and the CCDC assays (with detection rates of 48% and 20%, respectively). In conclusion, the N gene assays of CCDC assays and IPBCAMS assays and the ORF 1b gene assay of IPBCAMS assays were recommended for qRT-PCR screening of SARS-CoV-2.Competing Interest StatementThe authors have declared no competing interest.View Full Text

15.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-175778

RESUMO

Bats are a major "viral reservoir" in nature and there is a great interest in not only the cell biology of their innate and adaptive immune systems, but also in the expression patterns of receptors used for cellular entry by viruses with potential cross-species transmission. To address this and other questions, we created a single-cell transcriptomic atlas of the Chinese horseshoe bat (Rhinolophus sinicus) which comprises 82,924 cells from 19 organs and tissues. This atlas provides a molecular characterization of numerous cell types from a variety of anatomical sites, and we used it to identify clusters of transcription features that define cell types across all of the surveyed organs. Analysis of viral entry receptor genes for known zoonotic viruses showed cell distribution patterns similar to that of humans, with higher expression levels in bat intestine epithelial cells. In terms of the immune system, CD8+ T cells are in high proportion with tissue-resident memory T cells, and long-lived effector memory nature killer (NK) T-like cells (KLRG1, GZMA and ITGA4 genes) are broadly distributed across the organs. Isolated lung primary bat pulmonary fibroblast (BPF) cells were used to evaluate innate immunity, and they showed a weak response to interferon {beta} and tumor necrosis factor- compared to their human counterparts, consistent with our transcriptional analysis. This compendium of transcriptome data provides a molecular foundation for understanding the cell identities, functions and cellular receptor characteristics for viral reservoirs and zoonotic transmission.

16.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-052126

RESUMO

The current COVID-19 pandemic, caused by a novel coronavirus SARS-CoV-2, poses serious threats to public health and social stability, calling for urgent need for vaccines and therapeutics. SARS-CoV-2 is genetically close to SARS-CoV, thus it is important to define the between antigenic cross-reactivity and neutralization. In this study, we firstly analyzed 20 convalescent serum samples collected from SARS-CoV infected individuals during the 2003 SARS outbreak. All patient sera reacted strongly with the S1 subunit and receptor-binding domain (RBD) of SARS-CoV, cross-reacted with the S ectodomain, S1, RBD, and S2 proteins of SARS-CoV-2, and neutralized both SARS-CoV and SARS-CoV-2 S protein-driven infections. Multiple panels of antisera from mice and rabbits immunized with a full-length S and RBD immunogens of SARS-CoV were also characterized, verifying the cross-reactive neutralization against SARS-CoV-2. Interestingly, we found that a palm civet SARS-CoV-derived RBD elicited more potent cross-neutralizing responses in immunized animals than the RBD from a human SARS-CoV strain, informing a strategy to develop a universe vaccine against emerging CoVs. SummarySerum antibodies from SARS-CoV infected patients and immunized animals cross-neutralize SARS-CoV-2 suggests strategies for universe vaccines against emerging CoVs.

17.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-042010

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread across more than 200 countries and regions, leading to an unprecedented medical burden and live lost. SARS-CoV-2 specific antivirals or prophylactic vaccines are not available. Neutralizing antibodies provide efficient blockade for viral infection and are a promising category of biological therapies. Using SARS-CoV-2 spike RBD as a bait, we have discovered a panel of humanized single domain antibodies (sdAbs). These sdAbs revealed binding kinetics with the equilibrium dissociation constant (KD) of 0.7~33 nM. The monomeric sdAbs showed half maximal inhibitory concentration (IC50) of 0.003~0.3 g/mL in pseudotyped particle neutralization assay, and 0.23~0.50 g/mL in authentic SARS-CoV-2 neutralization assay. Competitive ligand-binding data suggested that the sdAbs either completely blocked or significantly inhibited the association between SARS-CoV-2 RBD and viral entry receptor ACE2. Finally, we showed that fusion of the human IgG1 Fc to sdAbs improved their neutralization activity by tens of times. These results reveal the novel SARS-CoV-2 RBD targeting sdAbs and pave a road for antibody drug development.

18.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-939389

RESUMO

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.

19.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20025460

RESUMO

BackgroundThe recent outbreak of infections by the 2019 novel coronavirus (2019-nCoV), the third zoonotic CoV has raised great public health concern. The demand for rapid and accurate diagnosis of this novel pathogen brought significant clinical and technological challenges. Currently, metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) are the most widely used molecular diagnostics for 2019-nCoV. Methods2019-nCoV infections were confirmed in 52 specimens by mNGS. Genomic information was analyzed and used for the design and development of an isothermal, CRISPR-based diagnostic for the novel virus. The diagnostic performance of CRISPR-nCoV was assessed and also compared across three technology platforms (mNGS, RT-PCR and CRISPR) Results2019-nCoVs sequenced in our study were conserved with the Wuhan strain, and shared certain genetic similarity with SARS-CoV. A high degree of variation in the level of viral RNA was observed in clinical specimens. CRISPR-nCoV demonstrated a near single-copy sensitivity and great clinical sensitivity with a shorter turn-around time than RT-PCR. ConclusionCRISPR-nCoV presents as a promising diagnostic option for the emerging pathogen.

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