Antibody dynamics to SARS-CoV-2 in Asymptomatic and Mild COVID-19 patients

ImportanceAsymptomatic COVID-19 infections have a long duration of viral shedding and contribute substantially to disease transmission. However, the missing asymptomatic cases have been significantly overlooked because of imperfect sensitivity of nucleic acid testing. We aimed to investigate the humoral immunity in asymptomatics, which will help us develop serological tests and improve early identification, understand the humoral immunity to COVID-19, and provide more rational control strategies for the pandemic. ObjectiveTo better control the pandemic of COVID-19, dynamics of IgM and IgG responses to 23 proteins of SARS-CoV-2 and neutralizing antibody in asymptomatic COVID-19 infections after exposure time were investigated. Design, setting, and participants63 asymptomatic individuals were screened by RT-qPCR and ELISA for IgM and IgG from 11,776 personnel returning to work, and close contacts with the confirmed cases in different communities of Wuhan by investigation of clusters and tracing infectious sources. 63 healthy contacts with both negative results for NAT and antibodies were selected as negative controls. 51 mild patients without any preexisting conditions were also screened as controls from 1056 patients during hospitalization in Tongji Hospital. A total of 177 participants were enrolled in this study and serial serum samples (n=213) were collected. The research was conducted between 17 February 2020 and 28 April 2020. Serum IgM and IgG profiles of 177 participants were further probed using a SARS-CoV-2 proteome microarray. Neutralizing antibody responses in different population were detected by a pseudotyped virus neutralization assay system. The dynamics of IgM and IgG antibodies and neutralizing antibodies were analyzed with exposure time or symptoms onset. ResultsAsymptomatics were classified into four subgroups based on NAT and serological tests. In particular, only 19% had positive NAT results while approximately 81% detected positive IgM/IgG responses. Comparative SARS-CoV-2 proteome microarray further demonstrated that there was a significantly difference of antibody dynamics responding to S1 or N proteins among three populations, although IgM and IgG profiles could not be used to differentiate them. S1 specific IgM responses were elicited in asymptomatic individuals as early to the seventh day after exposure and peaked on days from 17d to 25d, which might be used as an early diagnostic biomarker and give an additional 36.5% seropositivity. Mild patients produced stronger both S1 specific IgM and neutralizing antibody responses than asymptomatic individuals. Most importantly, S1 specific IgM/IgG responses and the titers of neutralizing antibody in asymptomatic individuals gradually vanished in two months. Conclusions and relevanceOur findings might have important implications for the definition of asymptomatic COVID-19 infections, diagnosis, serological survey, public health and immunization strategies.

Three-Dimensional Morphology Study of Capsule in Pseudophakic Eyes with High-Speed Swept-Source Optical Coherence Tomography.

PURPOSE: To study the capsule morphology in pseudophakic eyes on the three-dimensional level using high-speed swept-source optical coherence tomography (SSOCT). METHODS: This study collected patients with age-related cataract and divided them into two groups according to the anterior capsule and intraocular lens (IOL) optic relationship: total anterior capsule overlap (360°, Group-T) and partial anterior capsule overlap (<360°, Group-P). One standard SSOCT radial scanning was performed in all eyes at 1 day, 1 week, 1 month, and 3 months postoperatively. RESULTS: Thirty-two eyes from 25 patients were enrolled in the Group-T and 17 eyes from 13 patients in the Group-P. No eyes achieved complete adhesion between IOL optic and posterior capsule at 1 day after the surgery. However, the rate of complete adhesion was low (15/49, 30.6%) even at 3 months postoperatively and there was no statistically difference between Group-T and Group-P (21.9% vs. 47.1%, P > 0.05). At 1 day, 1 week, 1 month, and 3 months after the surgery, the capsule bend index (CBI) in the Group-T was 0.02 ± 0.09, 1.35 ± 1.48, 3.60 ± 0.54, and 3.88 ± 0.19, respectively. CBI rises linearly during the first month and the rise goes stable relatively with the great reduction of standard deviation in the following 2 months (All P < 0.05). The anterior capsule opening area and diameter were both reduced in the first month, and then they both became stable. CONCLUSIONS: With square-edge IOL, posterior capsule opacification risk is still high in most eyes at 3 months postoperatively for the complete adhesion of posterior capsule and IOL was only achieved in 30.6% eyes. IOL-in-bag may be driven by the significant capsule bag changes especially in the first month postoperatively.

The study of clinical indicators for identification of colonization and infection of Acinetobacter baumannii / 安徽医科大学学报

Objective To explore the clinical significance of T lymphocyte subsets and cytokines in the identifica-tion of Acinetobacter baumannii colonization and infection. Methods A total of 109 patients in hospital who had A. baumannii in sputum were collected. All patients were divided into colonization group (53 cases) and infection group (56 cases) according to the diagnostic criteria of hospital-acquired pneumonia by respiratory society, Chinese medical association. Another 50 healthy cases as control group. T lymphocyte subgroup and cytokines in peripheral blood were measured, the differences of T lymphocyte subgroup or cytokines between the groups were also com-pared. The factors of T lymphocyte subgroup or cytokines were analyzed by Spearman correlation analysis. Logistic regression analysis was used for investigating the predictors for the infection of A. baumannii. Results Between colonization group and infection group, the significant differences were been found in T lymphocytes subgroup, TNF-α,IFN-γ and IL-17. The A. baumannii infection was positively associated with TNF-α ( rs=0.241, P =0.012), IFN-γ (rs=0.235, P=0.014), IL-2(rs=0.249, P=0.009), IL-4(rs=0.268, P=0.005) and IL-17 (rs=0.538, P=0.000), whereas which was negatively associated with CD3 +(rs= -0.193, P=0.045) and CD4 +/CD8 +(rs= -0.302, P=0.001). IFN-γ and IL-17 was the independent factors for discrimination of A. baumannii infection by multivariate Logistic regression analysis. Conclusion Serum IFN-γ, IL-17 can be used as an indicator of Acinetobacter baumannii infection and colonization, and can provide a basis for the rational use of antimicrobial agents and nosocomial infection prevention and control.

Comparison of choroid thickness difference between myopia children corrected by spectacles and orthokeratology / 眼科新进展

Objective To investigate choroid thickness at horizontal meridian with optical coherence tomography (OCT) and compare the choroid thickness difference between first visit myopia children with those children who wear orthokeratology lens for more than 1 year.Methods This retrospective study enrolled 68 myopia children with low to moderate myopia (-1.00--6.00 D) who visited our hospital and took choroid images by OCT.The total subjects were divided into 2 groups.The subjects of 34 children in group 1 visited for myopia initially and wear spectacles.The other one group wear orthokeratology lens more than 1 year.Only the data of right eye were analyzed.Scans through the fovea at horizontal meridian were acquired with OCT.Choroid images were detected by custom software with 500 μm intervals up to 3.5 mm around fovea.Choroid thickness (CT) was calc~ated based on the average of the 7 zones.Statistical analysis was performed to evaluate choroid thickness at each zone.ANOVA was used to compare choroid thickness differences between various zones in each group.Paired t test was used to compare choroid thickness difference at the same zone between two groups.Results The mean age of OK lens group was (12.3 ± 1.8) years old,and the spectacles group was (11.8 ± 1.4) years old,there was no statistical difference.From temple to nasal choroid,the mean CT of the orthokeratology lens group were (296.7 ± 61.8) μm (T3),(290.7 ± 58.9) μm (T2),(285.7 ± 57.4) μm (T1),(278.5 ±57.7) μm (M),(262.2 ±57.9) μm (N1),(239.8 ±59.7) μm (N2),(214.7 ±59.0) μm (N3);And the mean CT of the spectacles group were (294.2 ± 45.4) μm (T3),(292.0±44.0) μm (T2),(283.6 ±45.5) μm (T1),(272.0 ±51.6) μm (M),(255.2 ± 56.3) μm (N1),(236.5 ±58.1)μm (N2),(212.8 ±57.7) μm (N3),respectively.The thicknesses were significantly thicker in temple zones than that in nasal zones in each group (all P ＜ 0.05),but the CT was not significantly different between the two groups in each zone (all P ＞ 0.05).Conclusion The choroid thickness has regional deference in myopia children,the thickest is in the temple and the thinnest in the nasal region.There is no significant difference between the children who initially corrected by spectacles and those who wear OK lens more than 1 year.

Antiviral effects of pudilan xiaoyan oral liquid on respiratory syncytial virus and adenovirus in vitro / 实用医学杂志

Objective To study the antiviral effects of Pudilan xiaoyan oral liquid on Hep-2 cell models infected with respiratory syncytial virus (RSV), adenoviruses serotype 3 strains (ADV3) in vitro. Methods The cell cytotoxic and inhibition effect of Pudilan xiaoyan oral liquid on RSV or ADV3 were investigated by MTT assay and the inhibitory assay for cytopathic effect (CPE) in Hep-2 cell cultures to detect its antiviral effects. Results The median toxic concentration (TC50) of Pudilan xiaoyan oral liquid on Hep-2 cells was 776.97 mg/L. The median effective concentration (EC50) of inhibiting RSV and ADV3 were 28.08, 28.10 mg/L,whose therapeutic index (TI) were 27.67 and 27.65 respectively. The safety coefficient of Pudilan xiaoyan oral liquid is higher than that of control, ribavirin. Compared with the virus control group, Pudilan xiaoyan oral liquid can obviously produce actions of a dose-dependent relationship to inhibit CPE in Hep-2 cells infected with RSV or ADV3 virus. Conclusions Pudilan xiaoyan oral liquid significantly improves the protection against RSV and ADV3 virus infection in Hep-2 cells. And the inhibition of CPE induced by viruses infection increased with the elevation of higher drug concentration for its antiviral effect augmented in vitro.

A design of refractometer based on blur circle / 中国医疗器械杂志

<p><b>OBJECTIVE</b>Design a convenient and stable eye refractometer based on the theory of blur circle.</p><p><b>METHODS</b>Analyze the retinal blur circle in both Emsly reduced eye model and Liou & Brennan 1997 eye model by ZEMAX. Design the coefficients including PD (pupil diameter) and NO' (length between node point and fovea) with the purpose of improving the accuracy. At last, compare the clinical optometry data from this refractor with the data obtained from optometry hospital in Wenzhou.</p><p><b>RESULTS</b>The blur circle diameters are nearly the same in both reduced eye model and the Liou & Brennan 1997 eye model. With the PD = 4 mm and NO' = 20 mm, the refractor shows a fine accuracy in optometry. The paired t test shows that the myopia group and the astigmatism axial direction group have no statistical difference between the data from the blur circle refractor and the hospital (P > 0.05), while the astigmatism degree group has the result of P = 0.41 which may be caused by the poor cooperation of pediatric patients. 80% of the astigmatism degree data differ from the data from the hospital in less than 0.75D.</p><p><b>CONCLUSION</b>The blur circle refractor, with the features of convenience and fine accuracy, is promised to be a new style of refractometer in the future.</p>

Expression of nuclear factor kappa B and inducible nitric oxide synthase in the respiratory syncytial virus infection on human lung epithelial cells / 中国组织工程研究

AIM: After human lung epithelial cells (A549) infected with respiratory syncytial virus (RSV), inducer cells over-express active transmitter. The study investigated the expression changes in nuclear factor ?B (NF-?B), inducible nitric oxide synthase (iNOS) mRNA and protein, nitric oxide (NO) and malonaldehyde (MDA) on human lung epithelial cells (A549) infected with RSV. METHODS: Experiments were performed at the Laboratory of Etiology and Immunology, Anhui Medical University between December 2006 and May 2007. ① Gyopreserved virus broliferated in Hep-2 cells after recovery. A549 cells infected with RSV in vitro were used to collect cells and cellular culture supernatant at hours 4, 8, 16 and 24. Cells non-infected with RSV were served as controls. ② Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the expression of iNOS mRNA. The expression of iNOS protein and NF-?B was detected by Western-Blot. The concentrations of NO and MDA were measured by nitrate reductase method and thiobarbituric acid method. RESULTS: ①The basal expression of NF-?B was increased with the prolongation of RSV infection to A549 cells. ②RSV infection to A549 increased the amounts of mRNA and protein of iNOS in a time-dependent manner. The expression of iNOS mRNA was about 12 times as many as basal expression. RSV infection promoted the expression of iNOS protein, which was higher than the control group. The activities of NF-?B significantly were positively correlated with the mRNA and protein expression of iNOS. ③RSV could improve A549 cells secreting NO and MDA, but the NO levels rose slowly during the 24 hours of infection. CONCLUSION: The inflammatory response of RSV can increase the activity of NF-?B and it is positive correlated with the increase in iNOS mRNA and protein levels.

Distribution of Hepatitis C Virus Genotypes in Southern Anhui Province / 中华医院感染学杂志

OBJECTIVE To investigate the relatedness between chronic hepatitis C patients in southern Anhui Province, and the serum ALT levels, the quantity of HCV RNA and the HCV genotypes. METHODS The rate method and fluorescence quantitative PCR method were used to detect serum levels of ALT and HCV RNA in 141 cases of chronic hepatitis C patients in southern Anhui Province. Reverse transcript PCR was used to genotype in 50 cases of specimens. RESULTS Spearman rank correlation analysis was used to analyze correlation between serum ALT levels and the quantity of HCV RNA, rs=0.213, P=0.011

The effects of supplemented with DHA on synaptic plasticity during development period in rats / 中国药理学通报

Aim To discover the change of synaptic plasticity by supplementing DHA during development period in rats. Method We divided Wistar rats into two groups: fish oil group and control group. The fish oil rats were supplemented with fish oil(5?10~3 ml?g-1 body weight) by gavage daily. The control rat was supplemented with NS of the same dose. 90 days later, each rat was hippocampus of anaesthetized and LTP and LTD were recorded at hippocampus of the same rat. Result Compared to the control group, DHA group presented an obvious increase in PS LTP, while no changes were found in EPSP LTP. On the other hand,DHA group demonstrated an obvious canceling effect on both EPSP and PS LTD. Conclusion There exist effects on synaptic plasticity after supplement with DHA. It may be one of the factors that DHA improves learning and memory.

Antiviral and Antibacterial Effects of the Effective Site of Traditional Chinese Medicine / 中药新药与临床药理

Objective To study the antiviral and antibacterial effects of the effective site of traditional Chinese medicine(TCM-ES).Methods Chicken embryoes were infected with influenza virus A(FM1 strain) and pre-injected with TCM-ES by means of chicken-embryo inoculation technique,and the antiviral effect of TCM-ES on chicken embryo was assayed by detecting the hemagglutination titers in allantoic fluids.Mice were orally pretreated with various dosages of drugs twice daily for 3 days,then were given drugs continuously for another 4 days following FM1 infection.The protective effects of TCM-ES on mice infected with FM1 were assayed by calculating the weight,index of lung,death-protection rate,and life-prolongation rate,etc.Ribavirin was used as the positive control.In addition,the antibacterial effects of TCM-ES were observed by detecting the minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) by test-tube dilution method.Results In chicken embryo experiments,TCM-ES showed a potential inhibiting effect on influenza virus with the MIC of 10 mg/mL,which was weaker than ribavirin.The results of animal experiment showed that the body-weight(BW) and pulmonary index of infected model group decreased evidently compared with those of the normal group,TCM-ES groups at the dosages of 750 mg/kg and 1500 mg/kg could reverse the decrease of BW and lung index as compared with the infected models,the difference being insignificant as compared with the normal group.Moreover,TCM-ES also increased the death-protection rate and life-prolongation rate of mice in a dose-dependent manner.TCM-ES at dosage of 10 mg/mL(MIC and MBC) had an antibacterial effect on staphylococcus,while had no effect on gram-negative bacilli.Conclusion TCM-ES has obvious antivirus effect on influenza virus FM1 strain,and also has certain antibacterial effect on staphylococcus,which is worth of further development and research.