The SARS-CoV-2 rS1-E-PLGA nanovaccine and evaluation of its immune effect in BALB/c mice

OBJECTIVE

Vaccination is an important method for preventing COVID-19 infection. However, certain vaccines do not meet the current needs. To improve the vaccine effect, discard ineffective antigens, and focus on high-quality antigenic clusters, S1-E bivalent antigens were designed.

MATERIALS AND METHODS

Vaccine delivery is performed using poly (lactic-co-glycolic acid) (PLGA). Here, the recombinant S1-E (rS1-E) was covered on PLGA and injected intramuscularly into mice. In total, 48 BALB/c mice were randomly divided into six groups with 8 mice in each group. The mice received intramuscular injections. Prior to vaccination, the hydrophobicity of the rS1-E and the antigenic site of the E protein were both analysed. The morphology, zeta potential, and particle size distribution of rS1-E-PLGA were examined. Anti-S1 and anti-E antibodies were detected in mouse serum by ELISA. Neutralising an-tibodies were detected by co-incubating the pseudovirus with the obtained serum. IL-2 and TNF-α levels were also measured.

RESULTS

The designed recombinant S1-E protein was successfully coated on PLGA nanoparticles. rS1-E-PLGA nanovaccine has suitable size, shape, good stability, sustained release and other characteristics. Importantly, mice were stimulated with rS1-E-PLGA nanovaccines to produce high-titre antibodies and a good cellular immune response.

CONCLUSIONS

Our results indicate that rS1-E-PLGA nanovaccine may provide a good protective effect, and the vaccine should be further investigated in human clinical trials for use in vaccination or as a booster.

Feasibility of an ultra-low dose contrast media protocol for coronary CT angiography

AIM

To evaluate the feasibility of an ultra-low volume contrast media (CM) protocol for coronary computed tomography angiography (CTA).

MATERIALS AND METHODS

In total, 214 patients receiving coronary CTA were enrolled prospectively and divided into group A (n=107) receiving a conventional dose of CM and group B (n=107) receiving an ultra-low dose. CT values of the right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX) were measured and radiation doses recorded. The image quality was compared between the groups. Changes in renal function indices and proteinuria before, 24, and 72 hours after coronary CTA among those with chronic kidney disease (CKD) were also assessed.

RESULTS

There were significant differences in CT values and radiation doses between groups A and B. In group A, the average RCA, LAD, and LCX CT values were 412.5 ± 79.2, 423.5 ± 73.7, and 422.0 ± 88.1 HU, respectively. In group B, the average RCA, LAD, and LCX CT values were 275.2 ± 16.2, 277.8 ± 16.4, and 278.9 ± 16.5 HU, respectively. The radiation dose in the ultra-low protocol recipients (118.70 ± 18.52 mGy·cm) was significantly lower than that used in conventional coronary CTA (131.75 ± 20.96 mGy·cm). The image quality of group B was comparable to that of group A, satisfying the diagnostic requirement. In patients with mild CKD, there were no significant differences in renal functions after coronary CTA.

CONCLUSION

An ultra-low CM protocol was established for coronary CTA, providing comparable image quality and diagnostic yields but significantly lower radiation dose compared with a conventional protocol. This new protocol might be applicable to patients with mild CKD.

Resting heart rate and incident atrial fibrillation: A stratified Mendelian randomization in the AFGen consortium

Background

Both elevated and low resting heart rates are associated with atrial fibrillation (AF), suggesting a U-shaped relationship. However, evidence for a U-shaped causal association between genetically-determined resting heart rate and incident AF is limited. We investigated potential directional changes of the causal association between genetically-determined resting heart rate and incident AF.

Method and results

Seven cohorts of the AFGen consortium contributed data to this meta-analysis. All participants were of European ancestry with known AF status, genotype information, and a heart rate measurement from a baseline electrocardiogram (ECG). Three strata of instrumental variable-free resting heart rate were used to assess possible non-linear associations between genetically-determined resting heart rate and the logarithm of the incident AF hazard rate: <65; 65–75; and >75 beats per minute (bpm). Mendelian randomization analyses using a weighted resting heart rate polygenic risk score were performed for each stratum.

We studied 38,981 individuals (mean age 59±10 years, 54% women) with a mean resting heart rate of 67±11 bpm. During a mean follow-up of 13±5 years, 4,779 (12%) individuals developed AF. A U-shaped association between the resting heart rate and the incident AF-hazard ratio was observed. Genetically-determined resting heart rate was inversely associated with incident AF for instrumental variable-free resting heart rates below 65 bpm (hazard ratio for genetically-determined resting heart rate, 0.96; 95% confidence interval, 0.94–0.99; p = 0.01). Genetically-determined resting heart rate was not associated with incident AF in the other two strata.

Conclusions

For resting heart rates below 65 bpm, our results support an inverse causal association between genetically-determined resting heart rate and incident AF.

[Analysis of HIV-1 genetic subtype and pretreatment drug resistance among men who have sex with men infected with HIV-1 from 19 cities of 6 provinces in China]

Objective: To investigate the distribution of HIV-1 genetic subtypes and pretreatment drug resistance (PDR) among men who have sex with men (MSM) from 19 cities of 6 provinces in China. Methods: From April to November 2019, 574 plasma samples of ART-naive HIV-1 infected MSM were collected from 19 cities in Hebei, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong provinces, total ribonucleic acid (RNA) was extracted and amplified the HIV-1 pol gene region by nested polymerase chain reaction (PCR) after reverse transcription. Then sequences were used to construct a phylogenetic tree to determine genetic subtypes and submitted to the Stanford drug resistance database for drug resistance analysis. Results: A total of 479 samples were successfully amplified by PCR. The HIV-1 genetic subtypes included CRF01_AE, CRF07_BC, B, CRF55_01B, CRF59_01B, CRF65_cpx, CRF103_01B, CRF67_01B, CRF68_01B and unrecognized subtype, which accounted for 43.4%, 36.3%, 6.3%, 5.9%, 0.8%, 0.8%, 0.4%, 0.4%, 0.2% and 5.5%, respectively. The distribution of genetic subtypes among provinces is statistically different (χ²=44.141, P<0.001). The overall PDR rate was 4.6% (22/479), the drug resistance rate of non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors were 3.5% (17/479), 0.8% (4/479) and 0.2% (1/479), respectively. The PDR rate of recent infections was significantly higher than that of long-term infections (χ²=4.634, P=0.031). Conclusions: The HIV-1 genetic subtypes among MSM infected with HIV-1 from 19 cities of 6 provinces in China are diverse, and the distribution of subtypes is different among provinces. The overall PDR rate is low, while the PDR rate of recent infections was significantly higher than that of long-term infections, suggesting the surveillance of PDR in recent infections should be strengthened.

ENETS standardized (synoptic) reporting for molecular imaging studies in neuroendocrine tumours

The European Neuroendocrine Tumor Society (ENETS) promotes practices and procedures that aim to improve the standard of care delivered to patients diagnosed with or suspected of having neuroendocrine neoplasia (NEN). At its annual Scientific Advisory Board Meeting in 2018, experts in imaging, pathology and clinical care of patients with NEN drafted guidance for the standardised reporting of diagnostic studies critical to the diagnosis, grading, staging and treatment of NEN. These included pathology, radiology, endoscopy and molecular imaging procedures. In an iterative process, a synoptic reporting template for molecular imaging procedures was developed to guide personalised therapies. Following pilot implementation and refinement within the ENETS Center of Excellence network, harmonisation with specialist imaging societies including the Society of Nuclear Medicine, European Association of Nuclear Medicine and the International Cancer Imaging Society will be pursued.

The Status of Iodine Nutrition after Removing Iodized Salt in High Water Iodine Regions: a Cross-sectional Study in China

Currently, the removal of iodized salt is carried out in high water iodine regions. The present situation of iodine nutrition and the prevalence of thyroid diseases in such regions have not been clearly elucidated. This study aimed to figure out these problems to help render effective measures for cases of abnormal iodine nutrition status. A cross-sectional study was carried out in four areas of Jining and Heze, Shandong Province, China, with different water iodine concentrations (WIC). In total, 1344 adults were enrolled in this study, and data related to their iodine nutrition, thyroid function, and thyroid ultrasonography were collected. Subjects were grouped according to WIC, urine iodine concentration (UIC), serum iodine concentration (SIC), and combined UIC and SIC for analysis. Iodine levels were in excess in the 100 μg/L ≤ WIC < 300 μg/L and WIC ≥ 300 μg/L areas. Compared with the control WIC group (10-100 μg/L), the WIC ≥ 300 μg/L group had a higher prevalence of thyroid autoimmunity (TAI, 21.25% vs. 13.19%, P <0.05), subclinical hypothyroidism (SH, 20.20% vs. 11.96%, P < 0.05), thyroid nodules (TN, 31.75% vs. 18.71%, P < 0.05), and thyroid dysfunction (23.62% vs. 12.26%, P < 0.05). Compared with the UIC control group (100-300 μg/L), high UIC group (≥ 800 μg/L) had a higher prevalence of TN (33.75% vs. 21.14%, P < 0.05) and thyroid dysfunction (25% vs. 14.47%, P < 0.05). Next, compared with the control SIC group (50-110 μg/L), high SIC group (≥ 110 μg/L) had a higher prevalence of TAI (33.80% vs. 14.47%, P < 0.05), SH (23.94% vs. 14.30%, P < 0.05), and thyroid dysfunction (33.80% vs. 15.29%, P < 0.05). Finally, subjects with the highest UIC and the highest SIC also had a higher prevalence of TAI (25.92% vs. 10.97%, P < 0.05), SH (23.45% vs. 10.97%, P < 0.05), TN (34.56% vs. 15.85%, P < 0.05), and thyroid dysfunction (27.16% vs. 13.41%, P < 0.05) than subjects with middle iodine levels. The iodine nutrition of subjects in the WIC ≥ 300 μg/L areas was still in excess after removing iodized salt from their diets. High levels of iodine also increased the prevalence of TAI, SH, TN, and thyroid dysfunction in those areas. Simply removing iodized salt may not be sufficient for high water iodine regions.

Comparison of the effects of different doses of Glucocorticoids on distinct subtypes of Guillain-Barré syndrome in Southern China

Background

The effect of Glucocorticoids (GCs) on the treatment of Guillain-Barré syndrome (GBS) has been controversial. There is no information on whether specific subtypes of GBS respond differently to GCs. In this setting, we aimed to discuss whether GCs treating yield different effects in the distinct subtypes (acute inflammatory demyelinating polyneuropathy, AIDP; acute motor axonal neuropathy, AMAN). And further, we analyzed the impact of different doses on the outcome.

Methods

Medical records of 448 patients with a diagnosis of classic GBS admitted to 31 tertiary hospitals, located in 14 provinces of Southern China, from 1 January 2013 to 30 September 2016, were retrospectively collected. And 251 patients treated with GCs alone (AIDP=189, AMAN=62) were reviewed and analyzed.

Results

After GCs treatment, the Hughes score of AIDP patients was significantly lower than that of AMAN patients at discharge (P=0.005) and 3 months after onset (P<0.001). Further analysis revealed that among AIDP patients, the high-dose group had significantly shorter hospital stay (P=0.023), lower Hughes score at nadir (P<0.001), at discharge (P=0.005), and 3 months after onset (P<0.001), compared with the low-dose group. However, for AMAN patients, the outcome difference between groups was nonsignificant.

Conclusion

Our data suggest that the high doses of GCs may result, at least in part, from the side of the duration of hospital stay and short-term outcome, favorable outcomes in AIDP patients. Therefore, we cannot completely deny the priority of GCs in the treatment of GBS, because the effect of different doses of GCs varies in treating different subtypes. More studies are needed in the future to further validate this issue.

Trial registration

ChiCTR-RRC-17014152. Registered 26 December 2017- Retrospectively registered.

Regional Differences of Guillain-Barré Syndrome in China: From South to North

Background

The epidemiological features of Guillain-Barré syndrome (GBS) were different in different areas; a comparison of the disease was needed to identify the variation and prognosis. We compare the epidemiological features of GBS in different areas in China.

Method

A total of 1,191 patients were included. Information was collected in patients diagnosed with GBS and its variants in middle and south China, and then retrospectively reviewed. The patients were divided into four different regions: East China (n = 441), Center China (n = 566), South China (n = 77), and Southwest China (n = 107). These subregions are mainly divided by climate and geographical location. These data were compared with data from a study in East China (Shandong, n = 150) and Northeast China (Changchun, n = 750).

Results

Patients from the south and southwest China were younger than other regions (P = 0.000). A summer peak and an autumn peak were found in northern China, but more patients in winter and spring days in other areas (P = 0.000). Upper respiratory tract infection (URTI) was the preceding event of GBS patients in all regions but rarer in central China (P = 0.001). The proportion of axonal subtype was higher in central and southwest China than in other regions (P = 0.001). Patients in southwest China were more served at nadir and have the longest hospital stay (P = 0.003 and P = 0.000).

Conclusion

The difference between seasonal variation and preceding events was found in different regions in China; clinical features differ among regions in China.

Viscoelasticity of 3D actin networks dictated by the mechanochemical characteristics of cross-linkers

In this study, we report a computational investigation on how the mechanochemical characteristics of crosslinking molecules influence the viscoelasticity of three dimensional F-actin networks, an issue of key interest in analyzing the behavior of living cells and biological gels. In particular, it was found that the continuous breakage and rebinding of cross-linkers result in a locally peaked loss modulus in the rheology spectrum of the network, reflecting the fact that maximum energy dissipation is achieved when the driving frequency of the applied oscillating shear becomes comparable to the dissociation/association rate of crosslinking molecules. In addition, we showed that when subjected to constant rate of shear, an actin network can exhibit either strain hardening or softening depending on the ratio between the loading rate and unbinding speed of cross-linkers. A criterion for predicting the transition from softening to hardening was also obtained, in agreement with recent experiments. Finally, significant structural evolution was found to occur in random networks undergoing mechanical "training" (i.e. under a constant applied shear stress over a period of time), eventually leading to a pronounced anisotropic response of the network afterward which again is consistent with experimental observations.

[PD-1 is associated with CD8(+)T lymphocyte dysfunction in patients with acute and chronic liver failure]

Objective: To explore whether peripheral blood CD8(+)T lymphocyte dysfunction is correlated with the programmed death receptor-1 (PD-1) expression in patients with acute-on-chronic liver failure (HBV-ACLF). Methods: Peripheral blood mononuclear cells (PBMC) were collected from patients with HBV-ACLF and healthy controls. CD8(+)T lymphocytes number and PD-1 expression condition in CD8(+)T lymphocytes were detected by flow cytometry. CD8(+)T lymphocytes isolated from peripheral blood of HBV-ACLF patients were further cultured in vitro. One group was added with PD-L1-IgG fusion protein (ACLF+PD-1 group), and the other group was added with IgG fusion protein (ACLF group). Proliferation ability (ki67), cell viability (CD69), and secretion ability of effector cytokines (IL-2, IFN-γ, TNF-α) were analyzed. Results: 30 cases with HBV-ACLF and healthy controls were enrolled. CD8(+)T lymphocytes absolute number was significantly lower in the peripheral blood of patients with ACLF group (333.88 ± 147.74)/μl than healthy controls (872.50 ± 206.64)/μl (P < 0.001). PD-1 expression in peripheral blood CD8(+)T lymphocytes were significantly increased in ACLF group (13.33% ± 2.52%), (P = 0.027) than healthy controls (7.02% ± 2.12%). In in vitro culture, compared with healthy controls, the peripheral blood CD8(+)T lymphocytes cell viability (CD69), proliferation ability (ki67) (all P ​​< 0.001), and the level of cytokine production (IL-2, IFN-γ, TNF-α) (all P < 0.05) were equally weakened in patients with ACLF group. Compared with ACLF group, CD8(+)T cell viability (CD69), proliferation ability (KI67) (all P < 0.05), and the level of cytokine production were weakened in ACLF+PD-1 group (all P < 0.05). Conclusion: HBV-ACLF patients have CD8(+)T lymphocyte dysfunction. Therefore, PD-1 may have correlation in the regulation of CD8(+)T lymphocyte dysfunction in ACLF patients.

Sodium MR Neuroimaging

Sodium MR imaging has the potential to complement routine proton MR imaging examinations with the goal of improving diagnosis, disease characterization, and clinical monitoring in neurologic diseases. In the past, the utility and exploration of sodium MR imaging as a valuable clinical tool have been limited due to the extremely low MR signal, but with recent improvements in imaging techniques and hardware, sodium MR imaging is on the verge of becoming clinically realistic for conditions that include brain tumors, ischemic stroke, and epilepsy. In this review, we briefly describe the fundamental physics of sodium MR imaging tailored to the neuroradiologist, focusing on the basics necessary to understand factors that play into making sodium MR imaging feasible for clinical settings and describing current controversies in the field. We will also discuss the current state of the field and the potential future clinical uses of sodium MR imaging in the diagnosis, phenotyping, and therapeutic monitoring in neurologic diseases.

[Treatment response to Conbercept of different types of diabetic macular edema classified based on optical coherence tomography]

OBJECTIVE

To compare different types of diabetic macular edema (DME) classified based on optical coherence tomography (OCT) for their responses to Conbercept injection and analyze the factors that affect the treatment responses.

METHODS

We retrospectively analyzed the clinical data of 65 patients (76 eyes) with DME diagnosed and treated with intravitreal injection of Conbercept (1+PRN) in our hospital from February, 2019 to February, 2021. According to OCT findings, DME in these patients was classified into cystic macular edema (CME; 28 eyes), serous retinal detachment (SRD; 33 eyes), and diffuse retinal thickening (DRT; 15 eyes). The best corrected visual acuity (BCVA) and central retinal thickness (CRT) were measured before and at 3 months after the first treatment. The baseline OCT characteristics of different types of DME were compared, and the correlation of these OCT characteristics with the treatment response to Conbercept was analyzed.

RESULTS

All the patients showed significant improvement of the BCVA 3 months after the treatment (P < 0.05). For all the 3 types of DME, the CRT at 3 months after the first treatment was significantly reduced as compared to the baseline (P < 0.05). The number of hyperreflective foci (HF) in the outer retina and the proportion of ellipsoid zone (EZ) interruption were the greatest in SRD group (P < 0.05). The baseline outer retinal HF was significantly correlated with the baseline CRT, CRT changes and CRT after treatment (all P < 0.05). The patients with baseline outer limiting membrane (ELM)/ EZ disruption had poorer baseline BCVA, greater baseline CRT, greater variation of CRT and poorer BCVA at 3 months after treatment (all P < 0.05).

CONCLUSION

For all the 3 types of DME, treatment with intravitreal injection of Conbercept can significantly improve the BCVA and CRT of the patients. DME of the SRD type has the best morphological response to Conbercept, while the DRT type has a relatively poor response. A greater number of HF at baseline may indicate a better morphological response to Conbercept treatment, and baseline ELM/EZ disruption may suggest a poor visual prognosis at 3 months after treatment.

P–389 The relationship between serum hormone profiles and missed abortion in humans

Study question

Are circulating profiles of metabolic-related hormones also associated with the missed abortion (MA) in humans?

Summary answer

Serum levels of fatty acid-binding protein–4 (FABP4) and fibroblast growth factor 21 (FGF21) are positively associated with MA.

What is known already

A cluster of endocrine hormones, including FABP4, FGF21, adiponectin, lipocalin–2 (LCN2), exhibit pleiotropic effects on regulating systematic metabolism. Serum levels of them are associated with gestational obesity and diabetes and affect pregnancy outcomes, however, the relationship between their circulating profiles and MA is under-investigated.

Study design, size, duration

78 patients with MA and 86 healthy pregnant subjects matching on maternal age and body mass index (BMI) were nested from a prospective cohort in the Chinese population.

Participants/materials, setting, methods

Fasting serum samples from all participants were collected to test their serum levels of FGF21, FABP4, adiponectin, and LCN2 by enzyme-linked immunosorbent assay method (ELISA).

Main results and the role of chance

There were no significant differences in circulating profiles of adiponectin and LCN2 between MA patients and healthy pregnant subjects. By contrast, circulating levels of FGF21 and FABP4 were significantly and independently elevated in patients with MA relative to control cases even after adjusting confounding factors (for FGF21: MA: 28.96 ± 2.17 ng/ml; HP: 19.18 ± 1.12 ng/ml, P &lt; 0.001, for FABP4: MA: 152.50 ± 9.31 pg/ml; HP: 90.86 ± 4.14 pg/ml, P &lt; 0.001). Linear regression analysis showed, FGF21 raised every 10 pg/ml contributed to a 24% (95% CI: 15% - 34%) increase in the risk of MA, whereas the OR of FABP4 for the risk of MA was 1.052 (95% CI: 1.022 –1.088). Furthermore, using serum FGF21 level or FABP4 levels discriminated MA from healthy controls with an area under the operating characteristic’s curve (AUROC) of 0.81 (95% CI 0.76–0.92) and 0.70 (95% CI 0.62 - 0.78), respectively.

Limitations, reasons for caution

The study is limited by the sample size. In addition, our results were based-on Chinese population, whether it could be observed in other ethics group remain to be investigated. Meanwhile, the cause-effect relationship between increased serum FGF21 level and MA remains to be explored.

Wider implications of the findings: Our data would suggest that serum levels of FGF21 and FABP4 are associated with MA. Moreover, circulating FGF21 levels may serve as a potential diagnostic biomarker for the recognition of M.

Trial registration number

IRB Ref. No.: KY201913