Preliminary experience of oral fruquintinib-capecitabine as a new maintenance treatment strategy for advanced colorectal cancer in the era of coronavirus disease 2019 (COVID-19): case report and literature review.

Background: Bevacizumab combined with fluorouracil is the currently recommended maintenance treatment for metastatic colorectal cancer, but the use of bevacizumab needs to be carried out in hospitals, which invisibly increases the risk of patients' exposure to coronavirus disease 2019 (COVID-19) during the COVID-19 epidemic. Therefore, except of the advantage of convenience, all oral drugs as the maintenance treatment can reduce hospitalization and potential exposure risk during the COVID-19 epidemic, which is worth further exploration. Case Description: First case was a 49-year-old male with stage IV colon adenocarcinoma and abnormal liver function who was given bevacizumab with FOLFOXIRI (8-cycles), following which his liver function recovered. Oxaliplatin was stopped upon thrombocytopenia development. The patient was finally maintained on oral fruquintinib and capecitabine therapy since November 2020, and has been progression-free for >15 months. Grade 2 leukopenia, neutropenia, and thrombocytopenia; grade 1 terminal nerve injury; and grade 1 hand and foot numbness were observed. The second case was a 48-year-old male with advanced colon cancer who underwent laparoscopic sigmoidectomy. Post-surgery, the patient was commenced on fluorouracil and leucovorin (1-cycle), followed by conversion therapy with cetuximab and chemotherapy (6-cycles). The patient underwent left hemi-hepatectomy, partial hepatectomy of the right lobe, and intraoperative radiofrequency ablation, following which he continued to receive cetuximab and chemotherapy. The patient was maintained on oral fruquintinib and capecitabine since December, 2020 and has been progression-free for >14 months. Grade1 myelosuppression, leukopenia, and neutropenia, grade 2 thrombocytopenia were observed. Conclusions: This case report based on preliminary evidence advocates oral fruquintinib-capecitabine maintenance treatment as an alternative to bevacizumab-capecitabine standard therapy for CRC patients, especially in the era of COVID-19 epidemic. This scheme can reduce hospitalization and potential COVID-19 contact, and is more convenient than intravenous administration. Which should be further explored in future studies.

A "Plug-and-Display" Nanoparticle Vaccine Platform Based on Outer Membrane Vesicles Displaying SARS-CoV-2 Receptor-binding Domain.

Biomimetic nanoparticles obtained from bacteria or viruses have attracted substantial interest in vaccine research and development. Outer membrane vesicles (OMVs) are mainly secreted by gram-negative bacteria during average growth, with a nano-sized diameter and self-adjuvant activity, which may be ideal for vaccine delivery. OMVs have functioned as a multifaceted delivery system for proteins, nucleic acids, and small molecules. To take full advantage of the biological characteristics of OMVs, bioengineered Escherichia coli-derived OMVs were utilized as a carrier and SARS-CoV-2 receptor-binding domain (RBD) as an antigen to construct a "Plug-and-Display" vaccine platform. The SpyCatcher (SC) and SpyTag (ST) domains in Streptococcus pyogenes were applied to conjugate OMVs and RBD. The Cytolysin A (ClyA) gene was translated with the SC gene as a fusion protein after plasmid transfection, leaving a reactive site on the surface of the OMVs. After mixing RBD-ST in a conventional buffer system overnight, covalent binding was formed between the OMVs and RBD. Thus, a multivalent-displaying OMV vaccine was achieved. By replacing with diverse antigens, the OMVs vaccine platform can efficiently display a variety of heterogeneous antigens, thereby potentially rapidly preventing infectious disease epidemics. This protocol describes a precise method for constructing the OMV vaccine platform, including production, purification, bioconjugation, and characterization.

Novel Synthetic Lipopeptides as Potential Mucosal Adjuvants Enhanced SARS-CoV-2 rRBD-Induced Immune Response.

As TLR2 agonists, several lipopeptides had been proved to be candidate vaccine adjuvants. In our previous study, lipopeptides mimicking N-terminal structures of the bacterial lipoproteins were also able to promote antigen-specific immune response. However, the structure-activity relationship of lipopeptides as TLR2 agonists is still unclear. Here, 23 synthetic lipopeptides with the same lipid moiety but different peptide sequences were synthesized, and their TLR2 activities in vitro and mucosal adjuvant effects to OVA were evaluated. LP1-14, LP1-30, LP1-34 and LP2-2 exhibited significantly lower cytotoxicity and stronger TLR2 activity compared with Pam2CSK4, the latter being one of the most potent TLR2 agonists. LP1-34 and LP2-2 assisted OVA to induce more profound specific IgG in sera or sIgA in BALF than Pam2CSK4. Furthermore, the possibility of LP1-34, LP2-2 and Pam2CSK4 as the mucosal adjuvant for the SARS-CoV-2 recombinant RBD (rRBD) was investigated. Intranasally immunized with rRBD plus either the novel lipopeptide or Pam2CSK4 significantly increased the levels of specific serum and respiratory mucosal IgG and IgA, while rRBD alone failed to induce specific immune response due to its low immunogenicity. The novel lipopeptides, especially LP2-2, significantly increased levels of rRBD-induced SARS-CoV-2 neutralizing antibody in sera, BALF and nasal wash. Finally, Support vector machine (SVM) results suggested that charged residues in lipopeptides might be beneficial to the agonist activity, while lipophilic residues might adversely affect the agonistic activity. Figuring out the relationship between peptide sequence in the lipopeptide and its TLR2 activity may lay the foundation for the rational design of novel lipopeptide adjuvant for COVID-19 vaccine.

Efficacy of Integrative Chinese-Western Medicine Treatments for COVID-19 Patients in ICU in Yichang, Hubei, China (preprint)

BackgroundThe prognosis of severe COVID-19 patients is poor. Traditional Chinese Medicine had an advantage in keeping microenvironmental balance in treating SARS and COVID-19.MethodsThis prospective cohort study compared the efficacy and safety of integrative Chinese-Western medicine (ICWM) treatments with Western medicine (WM) treatments in severe or critically ill patients. The outcomes included: mortality, hospital stay in ICU, days with ventilator-assisted ventilation, etc.ResultsA total of 72 confirmed COVID-19 patients in ICU were included. The median age of patients was 66 years (IQR: 53-77.5), and there were 32 female patients (44.4%). There were no significant differences in laboratory tests and complications after treatments between groups. A total of 36 (50%) patients died during hospitalization, and the mortality in the ICWM group (28.6%) was significantly lower than that of the WM group (63.6%, adjusted P=0.011). And the time of assisted ventilation was shorter in the ICWM group (adjusted P=0.341). However, the median hospital stay was significantly longer in the ICWM group (18 vs. 14 days, adjusted P＜0.05).ConclusionsICWM treatments could significantly reduce mortality for severe or critically ill patients with COVID-19, and it was safe and cost-effective to add Chinese medicine.

Prognostic value of neutrophil-to-lymphocyte ratio, lactate dehydrogenase, D-dimer and CT score in patients with COVID-19 (preprint)

Background To explore the significance of neutrophil-to-lymphocyte ratio (NLR), lactate dehydrogenase (LDH), D-dimer and CT score in evaluating the severity and prognosis of coronavirus disease – 2019 (COVID-19).Methods Patients with laboratory confirmed COVID-19 were retrospectively enrolled. The baseline data, laboratory findings, chest computed tomography (CT) results evaluating by CT score on admission, and clinical outcomes were collected and compared. The logistic regression was used to assess the independent relationship between the baseline level of four indicators (NLR, LDH, D-dimer, CT score) and the severity of COVID-19.Results Among 432 patients, 125 (28.94%) cases were divided into severe group, the remaining (n = 307, 71.06%) were in non-severe group. In multivariate logistic regression, high level of NLR, LDH were independent predictor of the severe group in COVID-19 (OR = 2.163; 95%CI = 1.162–4.026; p = 0.015 for NLR > 3.82; OR = 2.298; 95%CI = 1.327–3.979; p = 0.003 for LDH > 246U/L). Combining NLR > 3.82 and LDH > 246U/L increased the sensitivity of diagnosis in severe patients (NLR > 3.82 [50.40%] vs. Combined diagnosis [72.80%]; p = 0.0007; LDH > 246 [59.2%] vs. Combined diagnosis [72.80%]; p < 0.0001).Conclusions High levels of NLR and LDH in serum have potential value in the early identification of severe patients with COVID-19. The combination of LDH and NLR can improve the sensitivity of diagnosis.

A Mouse Model of SARS-CoV-2 Infection and Pathogenesis.

Since December 2019, a novel coronavirus SARS-CoV-2 has emerged and rapidly spread throughout the world, resulting in a global public health emergency. The lack of vaccine and antivirals has brought an urgent need for an animal model. Human angiotensin-converting enzyme II (ACE2) has been identified as a functional receptor for SARS-CoV-2. In this study, we generated a mouse model expressing human ACE2 (hACE2) by using CRISPR/Cas9 knockin technology. In comparison with wild-type C57BL/6 mice, both young and aged hACE2 mice sustained high viral loads in lung, trachea, and brain upon intranasal infection. Although fatalities were not observed, interstitial pneumonia and elevated cytokines were seen in SARS-CoV-2 infected-aged hACE2 mice. Interestingly, intragastric inoculation of SARS-CoV-2 was seen to cause productive infection and lead to pulmonary pathological changes in hACE2 mice. Overall, this animal model described here provides a useful tool for studying SARS-CoV-2 transmission and pathogenesis and evaluating COVID-19 vaccines and therapeutics.

Efficacy of Integrative Chinese-Western Medicine Treatments for COVID-19 Patients in ICU in Yichang, Hubei, China (preprint)

Background The prognosis of severe COVID-19 patients is poor. There are currently no definitely effective vaccines or antivirus drugs for COVID-19.Methods This prospective cohort study compared the efficacy and safety of integrative Chinese-Western medicine (ICWM) treatments with Western medicine (WM) treatments in severe or critically ill patients. The outcomes included: mortality, hospital stay in ICU, days with ventilator-assisted ventilation, etc.Results A total of 36 confirmed COVID-19 patients in ICU were included. The median age of patients was 66 years (IQR: 53-77.5), and there were 16 female patients (44.4%). There were no significant differences in laboratory tests and complications after treatments between groups. A total of 18 (50%) patients died during hospitalization, and the mortality in the ICWM group (28.6%) was significantly lower than that of the WM group (63.6%, adjusted P = 0.031). And the time of assisted ventilation was shorter in the ICWM group (adjusted P = 0.67). However, the median hospital stay was significantly longer in the ICWM group (18 vs. 14 days, adjusted P༜0.05).Conclusions ICWM treatments could significantly reduce the mortality and improve the clinical symptoms for severe or critically ill patients with COVID-19, and it was safe and cost-effective to add Chinese medicine.