Machine learning analysis of humoral and cellular responses to SARS-CoV-2 infection in young adults.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces B and T cell responses, contributing to virus neutralization. In a cohort of 2,911 young adults, we identified 65 individuals who had an asymptomatic or mildly symptomatic SARS-CoV-2 infection and characterized their humoral and T cell responses to the Spike (S), Nucleocapsid (N) and Membrane (M) proteins. We found that previous infection induced CD4 T cells that vigorously responded to pools of peptides derived from the S and N proteins. By using statistical and machine learning models, we observed that the T cell response highly correlated with a compound titer of antibodies against the Receptor Binding Domain (RBD), S and N. However, while serum antibodies decayed over time, the cellular phenotype of these individuals remained stable over four months. Our computational analysis demonstrates that in young adults, asymptomatic and paucisymptomatic SARS-CoV-2 infections can induce robust and long-lasting CD4 T cell responses that exhibit slower decays than antibody titers. These observations imply that next-generation COVID-19 vaccines should be designed to induce stronger cellular responses to sustain the generation of potent neutralizing antibodies.

Vaccines against the original strain of SARS-CoV-2 provide T cell memory to the B.1.1.529 variant.

BACKGROUND: The SARS-CoV-2 variant B.1.1.529 potentially escapes immunity from vaccination via a heavily mutated Spike protein. Here, we analyzed whether T cell memory towards the B.1.1.529 Spike protein is present in individuals who received two or three doses of vaccines designed against the original Wuhan strain of SARS-CoV-2. METHODS: PBMCs were isolated from two- and three-times vaccinated study participants and incubated in vitro with peptide pools of the Spike protein derived from sequences of the original Wuhan or the B.1.1.529 strains of SARS-CoV-2. Activated antigen-specific T cells were detected by flow cytometry. In silico analyses with NetMHCpan and NetMHCIIpan were used to determine differences in MHC class presentation between the original strain and the B.1.1.529 strain for the most common MHCs in the European-Caucasian population. RESULTS: Here we show, that both CD4 and CD8 responses to the B.1.1.529 Spike protein are marginally reduced compared to the ancestor protein and a robust T cell response is maintained. Epitope analyses reveal minor differences between the two SARS-CoV-2 strains in terms of MHC class presentations for the MHC-alleles being most common in the European-Caucasian population. CONCLUSIONS: The memory T cell response induced via first generation vaccination remains robust and is mostly unaffected by B.1.1.529 mutations. Correspondingly, in silico analyses of MHC presentation of epitopes derived from the B.1.1.529 Spike protein shows marginal differences compared to the ancestral SARS-CoV-2 strain.

Vaccination against SARS-CoV-2 results in the production of proteins called antibodies, that bind and inactivate the virus, and cells that help to eliminate it from the body in a future encounter, such as memory T cells. Both antibodies and memory T cells remain in the body after vaccination with memory T cells being present for longer than antibodies. Here, we determined that even though most of the first generation vaccines were created to prevent infection with the original SARS-CoV-2 virus, the memory T cells generated by this vaccination can also detect the omicron variant.

Detecting Oropharyngeal and Esophageal Emptying by Submental Ultrasonography and High-Resolution Impedance Manometry: Intubated vs. Non-Intubated Video-Assisted Thoracoscopic Surgery.

Postoperative swallowing, affected by general anesthesia and intubation, plays an important part in airway and oral intake safety regarding effective oropharyngeal and esophageal emptying. However, objective evidence is limited. This study aimed to determine the time required from emergence to effective oropharyngeal and esophageal emptying in patients undergoing non-intubated (N) or tracheal-intubated (I) video-assisted thoracoscopic surgery (VATS). Hyoid bone displacement (HBD) by submental ultrasonography and high-resolution impedance manometry (HRIM) measurements were used to assess oropharyngeal and esophageal emptying. HRIM was performed every 10 min after emergence, up to 10 times. The primary outcome was to determine whether intubation affects the time required from effective oropharyngeal to esophageal emptying. The secondary outcome was to verify if HBD is comparable to preoperative data indicating effective oropharyngeal emptying. Thirty-two patients suitable for non-intubated VATS were recruited. Our results showed that comparable HBDs were achieved in all patients after emergence. Effective esophageal emptying was achieved at the first HRIM measurement in 11 N group patients and 2 I group patients (p = 0.002) and was achieved in all N (100%) and 13 I group patients (81%) within 100 min (p = 0.23). HBD and HRIM are warranted for detecting postoperative oropharyngeal and esophageal emptying.

Effects of high-flow nasal oxygen during prolonged deep sedation on postprocedural atelectasis: A randomised controlled trial.

BACKGROUND: Atelectasis is common in patients undergoing prolonged deep sedation outside the operating theatre. High-flow nasal oxygen (HFNO) produces positive airway pressure which, hypothetically, should improve lung atelectasis, but this has not been investigated. OBJECTIVE: We investigated whether HFNO ameliorates postprocedural atelectasis and compared the influences of HFNO and facial oxygen by mask on postprocedural outcomes. DESIGN: A single-blind, open-label single-institution randomised controlled trial. SETTING: A single university hospital, from February 2017 to July 2019. PATIENTS: A total of 59 patients undergoing computed tomography (CT)-guided hepatic tumour radiofrequency ablation were randomly allocated to two groups. INTERVENTION: These patients randomly received HFNO (oxygen flow 10 l min before sedation and 50 l min during the procedure) or a conventional oxygen face mask (oxygen flow 10 l min) during the procedure. MAIN OUTCOME MEASURES: Changes in the area of lung atelectasis calculated on the basis of chest CT images and also recovery profiles were compared between the two groups. RESULTS: The two groups had comparable procedural profiles, but the HFNO group exhibited less postprocedural atelectasis than the face mask group (median [IQR] 7.4 [3.9 to 11.4%] vs. 10.5 [7.2 to 14.6%]; P = 0.0313). However, the numbers of patients requiring oxygen supplementation in the recovery room and during transport from the recovery room to the ward did not differ significantly between groups (24.1 vs. 50.0%; P = 0.0596). CONCLUSION: Our results suggested that HFNO ameliorates lung atelectasis after prolonged deep sedation in patients receiving CT-guided hepatic tumour radiofrequency ablation. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT03019354.

Induced and thymus-derived Foxp3⁺ regulatory T cells share a common niche.

Foxp3⁺ regulatory T (Treg) cells, which play a central role for the maintenance of immune homeostasis and self-tolerance, are known to be both generated in the thymus (thymus-derived, tTreg cells) and in the periphery, where they are converted from conventional CD4⁺ T cells (induced Treg (iTreg) cells). Recent data suggest a division of labor between these two Treg-cell subsets since their combined action was shown to be essential for protection in inflammatory disease models. Here, using the transfer colitis model, we examined whether tTreg cells and iTreg cells fill different niches within the CD4⁺ T-cell compartment. When naive T cells were co-transferred with either pure tTreg cells or with a mixture of tTreg cells and iTreg cells, induction of Foxp3⁺ Treg cells from naive T cells was not hampered by preoccupation of the Treg-cell niche. Using neuropilin-1 (Nrp1) as a surface marker to separate tTreg cells and iTreg cells, we demonstrate that tTreg cells and iTreg cells alone can completely fill the Treg-cell niche and display comparable TCR repertoires. However, when transferred together Nrp1⁺ tTreg cells outcompeted Nrp1⁻ iTreg cells and dominated the Treg-cell compartment. Taken together, our data suggest that tTreg cells and iTreg cells share a common peripheral niche.

Toxicological effects of cationic nanobubbles on the liver and kidneys: biomarkers for predicting the risk.

Nanobubbles with acoustical activity are used as both diagnostic and therapeutic carriers for detecting and treating diseases. We aimed to prepare nanobubbles and assess toxic responses to them in the liver and kidneys. The cytotoxicity of nanobubbles was determined by examining the viability of liver (HepG2) and kidney (293T) cell lines after a 24-h treatment at various concentrations (0.01-2%). Toxic effects of different formulations were compared by determining functional markers such as γ-glutamyl transferase (γ-GT) and blood urea nitrogen (BUN) after intravenous administration of nanobubbles. Cationic nanobubbles caused concentration-dependent cytotoxicity against cultured cells with a more significant effect in the liver than in the kidneys. A significant reduction of viability was revealed at a concentration as low as 0.1%. Cational systems with soyaethyl morpholinium ethosulfate (SME) exhibited the greatest γ-GT level at 6-fold higher than the control. Immunohistochemistry detected liver fibrosis and inflammation with nanobubbles treatment, especially SME-containing ones at higher doses. According to plasma proteomic profiles, gelsolin and fetuin-B were significantly downregulated 3-fold in the high-dose SME-treated group. Transthyretin decreased by 6-fold in this group. The fibrinogen gamma chain expression was highly elevated. The results suggest that these protein biomarkers are sensitive for assessing the risk of nanobubble exposure. This study is the first to systematically evaluate the possible toxicity of nanobubbles in the liver and kidneys.

Autographa californica multiple nucleopolyhedrovirus LEF-2 is a capsid protein required for amplification but not initiation of viral DNA replication.

The late expression factor 2 gene (lef-2) of baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been identified as one of the factors essential for origin-dependent DNA replication in transient expression assays and has been shown to be involved in late/very late gene expression. To study the function of lef-2 in the life cycle of AcMNPV, lef-2 knockout and repair bacmids were generated by homologous recombination in Escherichia coli. Growth curve analysis showed that lef-2 was essential for virus production. Interestingly, a DNA replication assay indicated that lef-2 is not required for the initiation of viral DNA replication and that, rather, it is required for the amplification of DNA replication. lef-2 is also required for the expression of late and very late genes, as the expression of these genes was abolished by lef-2 deletion. Temporal and spatial distributions of LEF-2 protein in infected cells were also analyzed, and the data showed that LEF-2 protein was localized to the virogenic stroma in the nuclei of the infected cells. Analysis of purified virus particles revealed that LEF-2 is a viral protein component of both budded and occlusion-derived virions, predominantly in the nucleocapsids of the virus particles. This observation suggests that LEF-2 may be required immediately after virus entry into host cells for efficient viral DNA replication.

Analysis of regional productivity growth in China: A generalized metafrontier MPI approach.

This paper analyzes the dynamics of China's productivity for the period 1996-2004 with a newly developed methodology - generalized metafrontier Malmquist productivity index (gMMPI). Implementing the gMMPI, this paper reviews the inequality of the coastal and non-coastal provinces, as well as the latent impact of scale efficiency change (SEC) for China. Using provincial data for the years 1996-2004, the empirical results are as follows. On average, China demonstrates an annual 3.191% productivity change, which is lower than 4.729% for the conventional MPI and accounts for about 26.508% of output growth over the period 1996-2004. Most of this change is propelled by technical progress, while a fraction is driven by the adjustment in production scale, and the efficiency change has an adverse effect. Furthermore, regional inequality is also found in this empirical work, and the productivity change of the coastal region is actually stronger than that of the non-coastal region. This paper also casts some focus on the China Western Development policy. Indeed, we do not find any outstanding achievement from the policy in the sample period, except that the west region sustained its rate of productivity change after 2000. Moreover, the SEC is found to be trivial in the advanced coastal region, but plays an important role in the relatively laggard non-coastal region. The implication of the positive SEC in the non-coastal region means that China's Western Development policy will improve the scale efficiency and the TFP growth of the west region.

Inducible nitric oxide synthase inhibitors of Chinese herbs III. Rheum palmatum.

In this paper, the effects of bioactive compounds of Rheum palmatum L. on the inhibition of NO production from RAW 264.7 cells were explored. Seven main anthraquinone derivatives were isolated from the root of R. palmatum, and of these, emodin and rhein significantly inhibited nitrite production from lipopolysaccharide (LPS)-activated RAW 264.7 cells. The IC(50) values for inhibition of nitrite production by emodin and rhein were 60.7 and 67.3 microM, respectively. After iNOS enzyme activity was stimulated by LPS for 12 h, treatment with emodin or rhein at 20 microg/ml for 18 h did not significantly inhibit NO production. The data show that the inhibitory activity of emodin and rhein is not due to direct inhibition of iNOS enzyme activity. However, expression of iNOS and the COX-2 protein was inhibited by emodin in LPS-activated RAW 264.7 cells, and PGE(2) production was reduced. Rhein also inhibited LPS-induced iNOS protein expression, but not COX-2 or PGE(2) production. On the other hand, inhibition effects on NO production from RAW 264.7 cells were enhanced and cytotoxic effects decreased by co-treatment with emodin and rhein. In conclusion, emodin and rhein are major iNOS inhibitors of R. palmatum and may possibly serve as bioactive substances for anti-inflammation effects.