Structural basis of a two-antibody cocktail exhibiting highly potent and broadly neutralizing activities against SARS-CoV-2 variants including diverse Omicron sublineages

SARS-CoV-2 variants of concern (VOCs), especially the latest Omicron, have exhibited severe antibody evasion. Broadly neutralizing antibodies with high potency against Omicron are urgently needed for understanding working mechanisms and developing therapeutic agents. In this study, we characterized previously reported F61, which was isolated from convalescent patients infected with prototype SARS-CoV-2, as a broadly neutralizing antibody against all VOCs including Omicron BA.1, BA.1.1, BA.2, BA.3 and BA.4 sublineages by utilizing antigen binding and cell infection assays. We also identified and characterized another broadly neutralizing antibody D2 with epitope distinct from that of F61. More importantly, we showed that a combination of F61 with D2 exhibited synergy in neutralization and protecting mice from SARS-CoV-2 Delta and Omicron BA.1 variants. Cryo-EM structures of the spike-F61 and spike-D2 binary complexes revealed the distinct epitopes of F61 and D2 at atomic level and the structural basis for neutralization. Cryo-EM structure of the Omicron-spike-F61-D2 ternary complex provides further structural insights into the synergy between F61 and D2. These results collectively indicated F61 and F61-D2 cocktail as promising therapeutic antibodies for combating SARS-CoV-2 variants including diverse Omicron sublineages.

Bioemulsification and Microbial Community Reconstruction in Thermally Processed Crude Oil.

Utilization of low-cost, environmental-friendly microbial enhanced oil recovery (MEOR) techniques in thermal recovery-processed oil reservoirs is potentially feasible. However, how exogenous microbes facilitate crude oil recovery in this deep biosphere, especially under mesophilic conditions, is scarcely investigated. In this study, a thermal treatment and a thermal recurrence were processed on crude oil collected from Daqing Oilfield, and then a 30-day incubation of the pretreated crude oil at 37 °C was operated with the addition of two locally isolated hydrocarbon-degrading bacteria, Amycolicicoccus subflavus DQS3-9A1T and Dietzia sp. DQ12-45-1b, respectively. The pH, surface tension, hydrocarbon profiles, culture-dependent cell densities and taxonomies, and whole and active microbial community compositions were determined. It was found that both A. subflavus DQS3-9A1T and Dietzia sp. DQ12-45-1b successfully induced culture acidification, crude oil bioemulsification, and residual oil sub-fraction alteration, no matter whether the crude oil was thermally pretreated or not. Endogenous bacteria which could proliferate on double heated crude oil were very few. Compared with A. subflavus, Dietzia sp. was substantially more effective at inducing the proliferation of varied species in one-time heated crude oil. Meanwhile, the effects of Dietzia sp. on crude oil bioemulsification and hydrocarbon profile alteration were not significantly influenced by the ploidy increasing of NaCl contents (from 5 g/L to 50 g/L), but the reconstructed bacterial communities became very simple, in which the Dietzia genus was predominant. Our study provides useful information to understand MEOR trials on thermally processed oil reservoirs, and proves that this strategy could be operated by using the locally available hydrocarbon-degrading microbes in mesophilic conditions with different salinity degrees.

Twelve-month specific IgG response to SARS-CoV-2 receptor-binding domain among COVID-19 convalescent plasma donors in Wuhan

To investigate the duration of humoral immune response in convalescent coronavirus disease 2019 (COVID-19) patients, we conduct a 12-month longitudinal study through collecting a total of 1,782 plasma samples from 869 convalescent plasma donors in Wuhan, China and test specific antibody responses. The results show that positive rate of IgG antibody against receptor-binding domain of spike protein (RBD-IgG) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the COVID-19 convalescent plasma donors exceeded 70% for 12 months post diagnosis. The level of RBD-IgG decreases with time, with the titer stabilizing at 64.3% of the initial level by the 9th month. Moreover, male plasma donors produce more RBD-IgG than female, and age of the patients positively correlates with the RBD-IgG titer. A strong positive correlation between RBD-IgG and neutralizing antibody titers is also identified. These results facilitate our understanding of SARS-CoV-2-induced immune memory to promote vaccine and therapy development.

Rapid Qualitative and Quantitative Analysis of Caffeine and Sodium Benzoate in Annaca by Infrared Spectroscopy / 法医学杂志

Objective To establish an infrared spectroscopic method for the rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples. Methods Qualitative and quantitative modeling samples were prepared by mixing high-purity caffeine and sodium benzoate. The characteristic absorption peaks of caffeine and sodium benzoate in Annaka samples were determined by analyzing the infrared spectra of the mixed samples. The quantitative model of infrared spectra was established by partial least squares （PLS）. Results By analyzing the infrared spectra of 17 mixed samples of caffeine and sodium benzoate （the purity of caffeine ranges from 10% to 80%）, the characteristic absorption peaks for caffeine were determined to be 1 698, 1 650, 1 237, 972, 743, and 609 cm-1. The characteristic absorption peaks for sodium benzoate were 1 596, 1 548, 1 406, 845, 708 and 679 cm-1. When the detection of all characteristic absorption peaks was the positive identification criteria, the positive detection rate of caffeine and sodium benzoate in 48 seized Annaka samples was 100%. The linear range of PLS quantitative model for caffeine was 10%-80%, the coefficient of determination （ R2） was 99.9%, the root mean square error of cross validation （RMSECV） was 0.68%, and the root mean square error of prediction （RMSEP） was 0.91%; the linear range of PLS quantitative model for sodium benzoate was 20%-90%, the R2 was 99.9%, the RMSECV was 0.91% and the RMSEP was 1.11%. The results of paired sample t test showed that the differences between the results of high performance liquid chromatography method and infrared spectroscopy method had no statistical significance. The established infrared quantitative method was used to analyze 48 seized Annaka samples, the purity of caffeine was 27.6%-63.1%, and that of sodium benzoate was 36.9%-72.3%. Conclusion The rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples by infrared spectroscopy method could improve identification efficiency and reduce determination cost.

The feasibility of convalescent plasma therapy in severe COVID-19 patients: a pilot study

Currently, there are no approved specific antiviral agents for 2019 novel coronavirus disease (COVID-19). In this study, ten severe patients confirmed by real-time viral RNA test were enrolled prospectively. One dose of 200 mL convalescent plasma (CP) derived from recently recovered donors with the neutralizing antibody titers above 1:640 was transfused to the patients as an addition to maximal supportive care and antiviral agents. The primary endpoint was the safety of CP transfusion. The second endpoints were the improvement of clinical symptoms and laboratory parameters within 3 days after CP transfusion. The median time from onset of illness to CP transfusion was 16.5 days. After CP transfusion, the level of neutralizing antibody increased rapidly up to 1:640 in five cases, while that of the other four cases maintained at a high level (1:640). The clinical symptoms were significantly improved along with increase of oxyhemoglobin saturation within 3 days. Several parameters tended to improve as compared to pre-transfusion, including increased lymphocyte counts (0.65x109/L vs. 0.76x109/L) and decreased C-reactive protein (55.98 mg/L vs. 18.13 mg/L). Radiological examinations showed varying degrees of absorption of lung lesionswithin 7 days. The viral load was undetectable after transfusion in seven patients who had previous viremia. No severe adverse effects were observed. This study showed CP therapy was welltolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. The optimal dose and time point, as well as the clinical benefit of CP therapy, needs further investigation in larger well-controlled trials. Significance StatementCOVID-19 is currently a big threat to global health. However, no specific antiviral agents are available for its treatment. In this work, we explored the feasibility of convalescent plasma (CP) transfusion to rescue severe patients. The results from 10 severe adult cases showed that one dose (200 mL) of CP was welltolerated and could significantly increase or maintain the neutralizing antibodies at a high level, leading to disappearance of viremia in 7 days. Meanwhile, clinical symptoms and paraclinical criteria rapidly improved within 3 days. Radiological examination showed varying degrees of absorption of lung lesions within 7 days. These results indicate that CP can serve as a promising rescue option for severe COVID-19 while the randomized trial is warranted.

Effect of optimized green channel under plan-do-check-action on shortening door-to-needle time and improving early neurological function in patients with intravenous thrombolysis / 中国医师进修杂志

Objective:To investigate the effect of optimized construction of green channel under plan-do-check-action (PDCA) on shortening the door-to-needle time (DNT) and improving early neurological improvement in patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis.Methods:The clinical data of 120 patients with AIS treated with intravenous thrombolysis from June 2018 to September 2019 in Liangxiang Teaching Hospital of Capital Medical University were retrospectively analyzed. Among them, 60 patients were admitted to hospital before optimized as non-optimized group, and 60 patients were admitted to hospital after optimized as optimized group. The time from visit to CT examination completion, time from CT examination completion to informed consent, time from informed consent to intravenous thrombolysis, DNT, DNT ≤ 60 min ratio, National Institutes of Health stroke scale (NIHSS) score 2 h after intravenous thrombolysis and at discharge from hospital, early neurological improvement (ENI) rate, hospital stays, adverse outcomes and mortality were compared between 2 groups.Results:The time from CT examination completion to informed consent and DNT in optimized group were significantly shorter than those in non-optimized group: 29 (14, 36) min vs. 37 (21, 54) min, 55 (45, 67) min vs. 76 (54, 93) min, the DNT ≤ 60 min ratio was significantly higher than that in non-optimized group: 68.3% (41/60) vs. 35.0% (21/60), the ENI rate was significantly lower than that in non-optimized group: 28.3% (17/60) vs. 46.7% (28/60), and there were statistical differences ( P<0.05 or<0.01). There were no statistical differences in the time from visit to CT examination completion, time from informed consent to intravenous thrombolysis, NIHSS score 2 h after intravenous thrombolysis, hospital stays, NIHSS score at discharge from hospital, adverse outcomes rate and mortality between 2 groups ( P>0.05). Conclusions:The optimized construction of green channel under PDCA can effectively shorten the DNT of intravenous thrombolysis in patients with AIS, and may be significantly important for improving the long-term prognosis of patients.

The relationship between ABO blood group distribution of COVID-19 convalescents and the plasma antibody titer against SARS-CoV-2 / 中华急诊医学杂志

Objective:To perform a statistical analysis of the ABO blood group distribution of COVID-19 convalescents, and further analyze the ABO blood group distribution in COVID-19 convalescents with different plasma antibody titer against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).Methods:Convalescent plasma was collected from 150 patients aged 18-60 years old who had recovered from COVID-19. Convalescent plasma was collected 14 days later after patients discharged from hospital, and another 180 normal people in Wuhan city were served as healthy control group. Then we analyzed the relationship between age, gender and the ABO blood group distribution. We also tried to clarify the relationship between plasma antibody liter against SARS-CoV-2 and the ABO blood group distribution.Results:Compared with the healthy control group, the proportion of blood group B in COVID-19 convalescents was higher (36% vs 25.0%, χ 2=4.714, P<0.05). The ABO blood group distribution did not differ from male and female COVID-19 convalescents, while age affected the ABO blood group distribution of COVID-19 convalescents. Among the age group under 40 years old, the proportion of blood group B in COVID-19 convalescents was higher than that in the healthy control group (38.5% vs 25.0%, χ 2=5.264, P<0.05). The antibody titer against SARS-CoV-2 in 5.3% of the convalescent plasma was under 1:80. In the high antibody liter against SARS-CoV-2 group, the proportion of blood group B in COVID-19 convalescents was higher than that in the healthy control group (35.2% vs 25.0%, χ 2=3.979, P<0.05). Conclusions:COVID-19 convalescents with blood group B and age group under 40 years old have a higher proportions than that in the normal people. Part of the convalescents with lowantibody liter against SARS-CoV-2 didn’t meet the conditions for plasma donation. Convalescents with blood group B may be more suitable as plasma donators for the therapy of COVID-19.

Predictive Value of Head-Neck CTA Combined with ABCD2 Scale Score for Patients with Cerebral Infarction of Vertebrobasilar Transient Ischemic Attack (TIA).

BACKGROUND The present study was designed to evaluate the predictive value of head-neck computed tomography angiography (CTA) combined with ABCD2 score scale for patients with cerebral infarction of vertebrobasilar transient ischemic attack (TIA). MATERIAL AND METHODS A total of 92 patients with TIA who were admitted to our hospital from January 2014 to June 2015 were enrolled in this study. ABCD2 score and CTA combined with ABCD2 score were assessed. RESULTS The incidence of cerebral infarction was highest in the high-risk group, followed by the middle-risk group and low-risk group. The incidence of cerebral infarction was related to the degree of stenosis in head-neck CTA, which was highest in the severe stenosis group, followed by the moderate stenosis group and mild stenosis/normal group, with significant differences. The incidence of cerebral infarction in patients with cerebral artery stenosis was correlated with the incidence of cerebral infarction in the head and neck CTA, which was severe > medium > normal/low (P<0.05). CONCLUSIONS The ABCD2 score can accurately predict the early development from TIA to cerebral infarction. If it is used in combination with head-neck CTA; CTA combined ABCD2 score can further improve the accuracy of prediction, which makes it feasible for use in prediction of the development of vertebrobasilar TIA to cerebral infarction.

Role of the Group 2 Mrp sodium/proton antiporter in rapid response to high alkaline shock in the alkaline- and salt-tolerant Dietzia sp. DQ12-45-1b.

The six- and seven-subunit Na+/H+ antiporters (Mrp) are widely distributed in bacteria. They are reported to be integral for pH homeostasis in alkaliphilic bacteria when adapting to high pH environments. In this study, operons encoding for the six-subunit Na+/H+ antiporters were found in the genomes of all studied Dietzia strains, which have different alkaline-resistant abilities. Disruption of the operon in the strain Dietzia sp. DQ12-45-1b which leads to declined growth in presence of hypersaline and alkaline conditions suggested that the six-subunit Na+/H+ antiporter played an important role in hypersaline and alkaline resistance. Although the complexes DqMrp from DQ12-45-1b (strain with high alkaline resistance) and DaMrp from D. alimentaria 72T (strain with low alkaline resistance) displayed Na+(Li+)/H+ antiport activities, they functioned optimally at different pH levels (9.0 for DQ12-45-1b and 8.0 for 72T). While both antiporters functioned properly to protect Escherichia coli cells from salt shock, only the DqMrp-containing strain survived the high alkaline shock. Furthermore, real-time PCR results showed that the expression of mrpA and mrpD induced only immediately after DQ12-45-1b cells were subjected to the alkaline shock. These results suggested that the expression of DqMrp might be induced by a pH gradient across the cell membrane, and DqMrp mainly functioned at an early stage to respond to the alkaline shock.

Effect of ~(56)Fe~(17+) heavy ion on the expression of phosphorylated histone H2AX of human lymphocytes / 中国职业医学

OBJECTIVE: To explore the effect of~(56)Fe~(17+)heavy ion on the expression of phosphorylated histone H2AX( γH2AX) of human lymphccytes. METHODS: The Epstein-Barr virus transformed human B lymphocyte cell lines( PengEBV) were selected and exposed to~(56)Fe~(17+)heavy ion at irradiation dose of 0. 0( control group),0. 1,0. 3,0. 5,0. 7,1. 0 and 2. 0 Gy,respectively,with the dosing rate of 0. 23-0. 55 Gy / min. Flow-cytometry was used to detect the changes of expression of γH2AX at time points of 0,2,4,8,48 and 72 hours after irradiation. RESULTS: The expression of γH2AX showed interaction existed between radiation dose and the treatment time after radiation( P < 0. 01). Compared with the control at the same time points,the expression of γH2AX increased at the dose of 0. 3-2. 0 Gy and the time points of 2-72hours( P < 0. 05). The expression of γH2AX at the dose of 0. 3-2. 0 Gy and time points of 8-72 hours was lower than those at the same dose and time points of 2 and 4 hours( P < 0. 05). When the dose was at 0. 5,1. 0 or 2. 0 Gy,the expression of γH2AX decreased with the increasing time of exposure in 72 hours( P < 0. 05). At the dose of 0. 0-1. 0 Gy and the time points of 2-4 hours,the expression of γH2AX increased with the increasing dose of irradiation( P < 0. 01). CONCLUSION: The expression of γH2AX in Peng-EBV cells shows a dose-response relationship within 2-4 hours after 0. 0-1. 0 Gy irradiation of~(56)Fe~(17+).

Telomerase Expression in Peripheral Blood Mononuclear Cells in Children with Acute Kawasaki Disease / 实用儿科临床杂志

Objective To study the telomerase expression in peripheral blood mononuclear cells(PBMCs) in children with acute Kawasaki disease(KD) and its clinical significance.Methods The PBMCs of 64 children with acute KD [25 cases of them with coronary artery lesions(CAL),while the rest without] from 2 months to 6 years old admitted into Jiangxi Children's Hospital from Mar.2005 to Dec.2008 and those of 52 sex-age-matched healthy children (healthy control group) from 5 months to 7 years old were all assayed by Roche telomerase polymerase chain reaction enzymelinked immunosorbent assay(PCR ELISA).WBC,ESR and CRP were also detected.SPSS 11.0 software was used to analyze the data.Results The telomerase expression frequency of PBMCs in children with KD was 32.8%(21/64 cases),while that in healthy control group was only 15.4%(8/52 cases),the difference between the 2 groups was significant (?2= 4.65,P0.05).There were no significant difference of WBC,ESR and CRP between the telomerase of PBMCs positive group and negative group.Conclusions The higher frequency of telomerase expression in peripheral blood lymphocytes might be related to the development and progression of KD.

Nuclear Factor-?B Activation in Peripheral Blood Mononuclear Cells during Acute Kawasaki Disease / 实用儿科临床杂志

Objective To explore the significance of nuclear factor-?B(NF-?B)activation in peripheral blood mononuclear cells(PBMC)during acute Kawasaki disease(KD).Methods Peripheral blood was collected from children with acute KD(n=30)and healthy age-matched children(n=20).PBMC were cultured in vitro and divided into 3 groups:naturally cultured blank control group,protein kinase C(PKC)activator stimulated phorbol 12-myristate 13-acetate(PMA)group and PMA plus NF-?B inhibitor treated PMA plus pyrrolidine dithiocarbamate(PDTC)group.Percentages of NF-?B activation were detected by immunohistochemistry.Results Under natural culturing,the percentage of cells with activated NF-?B was significantly higher in acute KD blank control group than that in healthy blank control group.The percentage of cells with activated NF-?B was significantly higher in acute KD PMA group than that in acute KD blank group and that in normal control PMA group,respectively(Pa0.05).Conclusions NF-?B activation in PBMC during acute KD is markedly increased,which suggests that NF-?B activation plays an important role in the formation of vasulitis and CAL in this disease.NF-?B activation in PBMCs in children with KD is regulated by the PKC signaling pathway and PDTC obviously inhibits the activation of NF-?B.J Appl Clin Pediatr,2009,24(1):35-37