Thousands of variant gene sequences of SARS-CoV-2 have been emerged since the COVID-19 epidemic broke out in Dec.2019.Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),Delta(B.1.617.2)and Omicron(B.1.1.529)were the most representative variants.With the continuous emergence of new variants,the predomi-nant strain in the global pandemic as of Jan.2025 is the Omicron BA.2.86-derived mutant,JN.1.The effectiveness of drugs against Omicron variants remains a key research focus in the treatment of SARS-CoV-2 infections.The infectiousness and pathogenicity of the variants altered remarkably due to mutations in the genome on S protein of the mutant strains,and these emerging variants are more likely to evade immunity and were more infectious than the previous prevalent variants.During the process of combating with the constantly emerging novel variants,drugs showed various effects on treatment of diseases caused by different variants.New drugs and treatment coun-termeasures are constantly updated with the prevalence of various variants.The current status of research on pres-ent drugs for treatment of SARS-CoV-2 and the therapeutic effects on emerging variants are reviewed in the article so as to provide reference for prevention and treatment of the upcoming evolved variants.

BACKGROUND:The cryopreservation technology enables tissues/cells to be stored for a long time in a low-temperature environment while maintaining the integrity of their activity and function,which is of great significance for the construction of cell therapy,tissue engineering and biological sample banks.Cryoprotective agents often contain dimethyl sulfoxide and serum.To avoid the toxic side effects of dimethyl sulfoxide,the complexity of serum components and immune responses,although some finished cryoprotective agents have been marketed,they are faced with many difficulties such as high cost and limited application.Therefore,there is an urgent need to develop a cryoprotective agent with clear components and the ability to solve the above problems.OBJECTIVE:To evaluate the effects of a novel cryoprotectant on cryopreservation efficiency of different tissue and cell sources.METHODS:By applying the novel cryoprotectant as an experimental group with the commercially available and widely used cryoprotectant(control group)to umbilical cord Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,NK and CIK cells,comparative analyses were conducted in terms of cell morphology,number,viability,surface markers,differentiation potential,and cell-killing toxicity assay before cryopreservation and after resuscitation thawing.We confirmed the cryopreservation effect of the new cryoprotectant and its potential application value.RESULTS AND CONCLUSION:(1)The novel cryoprotectant facilitated the normal growth of cryopreserved Wharton's jelly tissue upon recovery,exhibiting mesenchymal stem cell morphology.No significant differences were observed between the experimental and control groups in terms of cell recovery rate,surface markers,and differentiation potential.(2)There was no significant difference in the number and viability of cells between the experimental group and the control group after cryopreservation of cord blood/peripheral blood mononuclear cells,and the cryo-resuscitated cell numbers and viability of derived NK cells/CIK cells did not show significant difference between the experimental and control groups.(3)For NK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportion of CD56+CD16+cell subpopulations between the experimental group and the control group.For CIK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportions of CD3+CD8+and CD3+CD56+cell subpopulations between the experimental group and the control group.(4)In terms of cytotoxicity testing,when the effective-target ratio of immune cells and melanoma cell line Mel624 was 20:1,whether it was NK cells/CIK cells derived from cord blood or peripheral blood mononuclear cells,there was no significant difference in the tumoricidal activity of cells between the experimental group and the control group.These findings suggest that the novel cryoprotectant can replace existing commercially available and widely used cryoprotectants,and is applicable to Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,as well as NK and CIK cells,providing a solid technical foundation for the scaling,standardization,and commercialization of universal cryoprotectants.

Thousands of variant gene sequences of SARS-CoV-2 have been emerged since the COVID-19 epidemic broke out in Dec.2019.Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),Delta(B.1.617.2)and Omicron(B.1.1.529)were the most representative variants.With the continuous emergence of new variants,the predomi-nant strain in the global pandemic as of Jan.2025 is the Omicron BA.2.86-derived mutant,JN.1.The effectiveness of drugs against Omicron variants remains a key research focus in the treatment of SARS-CoV-2 infections.The infectiousness and pathogenicity of the variants altered remarkably due to mutations in the genome on S protein of the mutant strains,and these emerging variants are more likely to evade immunity and were more infectious than the previous prevalent variants.During the process of combating with the constantly emerging novel variants,drugs showed various effects on treatment of diseases caused by different variants.New drugs and treatment coun-termeasures are constantly updated with the prevalence of various variants.The current status of research on pres-ent drugs for treatment of SARS-CoV-2 and the therapeutic effects on emerging variants are reviewed in the article so as to provide reference for prevention and treatment of the upcoming evolved variants.

Objective:To investigate the efficacy of preoperative ultrasound-guided injection of carbon nanoparticle suspension in cervical lymph node dissection for thyroid cancer reoperation.Methods:Ninety-four patients undergoing reoperation for thyroid cancer admitted by the same physician team of the Department of Thyroid and Breast Surgery of the Ninety-sixty Hospital of the People’s Liberation Army (PLA) from Jan. 2019 to Sep. 2024 were retrospectively analyzed. According to the different scope of the initial surgery, they were divided into the re-specification clearance group, the regional lymph node clearance group, and the metastatic lymph node dissection group, and the groups were subdivided into the carbon nanoparticle group and the control group according to whether they were injected with carbon nanoparticle before the surgery or not. The t-test, χ2-test, and non-parametric test were used to compare the age, gender, surgical method, duration of surgery, total number of lymph nodes detected, and positive lymph node detection rate between the nano-charcoal group and the control group in the three groups. Results:There was no statistically significant difference between the three groups in terms of age, gender, surgical methods, or the total number of lymph nodes detected (all P>0.05) , and the difference between the surgical time of the carbon nanoparticle group in the re-regulation clearance group and the control group was not statistically significant ( P>0.05) ; the surgical time of the carbon nanoparticle group was shorter than that of the control group in both the regional lymph node clearance and the metastatic lymph node dissection groups, and the difference was statistically significant (all P<0.05) ; the positive detection rate of lymph nodes in the carbon nanoparticle group was higher than that in the control group among the three groups, and the difference was statistically significant (all P<0.05) . Conclusion:In the operation of cervical lymph node dissection for papillary thyroid cancer, preoperative ultrasound-guided injection of carbon nanoparticle can accurately localize the lymph nodes, increase the positive detection rate of lymph nodes, reduce the difficulty of surgical operation, and shorten the operation time.

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.

Objective: Neuronal apoptosis is considered to be a critical process in spinal cord injury (SCI). Despite growing evidence of the antiapoptotic, anti-inflammatory, and modulation of ischemic injury tolerance effects of extracellular ubiquitin (eUb), existing studies have paid less attention to the impact of eUb in neurological injury disorders, particularly in SCI. This study aimed to investigate whether eUb can play a protective role in neurons, both in vitro and in vivo, and explores the underlying mechanisms. Methods: By utilizing an oxygen glucose deprivation cellular model and a SCI rat model, we firstly investigated the therapeutic effects of eUb on SCI and further explored its effects on neuronal autophagy and mitochondria-dependent apoptosis-related indicators, as well as the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mechanical target of rapamycin (mTOR) signaling pathway. Results: In the SCI models both in vivo and in vitro, early intervention with eUb enhanced neuronal autophagy and inhibited mitochondrial apoptotic pathways, significantly mitigating SCI. Further studies had shown that this protective effect of eUb was mediated through its receptor, CXC chemokine receptor type 4 (CXCR4). Additionally, eUb-enhanced autophagy and antiapoptotic effects were possibly associated with inhibiting the PI3K/Akt/mTOR pathway. Conclusion In summary, the study demonstrates that early eUb intervention can enhance autophagy and inhibit mitochondrial apoptotic pathways via CXCR4, protecting neurons and promoting SCI repair.

Objective: Neuronal apoptosis is considered to be a critical process in spinal cord injury (SCI). Despite growing evidence of the antiapoptotic, anti-inflammatory, and modulation of ischemic injury tolerance effects of extracellular ubiquitin (eUb), existing studies have paid less attention to the impact of eUb in neurological injury disorders, particularly in SCI. This study aimed to investigate whether eUb can play a protective role in neurons, both in vitro and in vivo, and explores the underlying mechanisms. Methods: By utilizing an oxygen glucose deprivation cellular model and a SCI rat model, we firstly investigated the therapeutic effects of eUb on SCI and further explored its effects on neuronal autophagy and mitochondria-dependent apoptosis-related indicators, as well as the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mechanical target of rapamycin (mTOR) signaling pathway. Results: In the SCI models both in vivo and in vitro, early intervention with eUb enhanced neuronal autophagy and inhibited mitochondrial apoptotic pathways, significantly mitigating SCI. Further studies had shown that this protective effect of eUb was mediated through its receptor, CXC chemokine receptor type 4 (CXCR4). Additionally, eUb-enhanced autophagy and antiapoptotic effects were possibly associated with inhibiting the PI3K/Akt/mTOR pathway. Conclusion In summary, the study demonstrates that early eUb intervention can enhance autophagy and inhibit mitochondrial apoptotic pathways via CXCR4, protecting neurons and promoting SCI repair.

Objective: Neuronal apoptosis is considered to be a critical process in spinal cord injury (SCI). Despite growing evidence of the antiapoptotic, anti-inflammatory, and modulation of ischemic injury tolerance effects of extracellular ubiquitin (eUb), existing studies have paid less attention to the impact of eUb in neurological injury disorders, particularly in SCI. This study aimed to investigate whether eUb can play a protective role in neurons, both in vitro and in vivo, and explores the underlying mechanisms. Methods: By utilizing an oxygen glucose deprivation cellular model and a SCI rat model, we firstly investigated the therapeutic effects of eUb on SCI and further explored its effects on neuronal autophagy and mitochondria-dependent apoptosis-related indicators, as well as the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mechanical target of rapamycin (mTOR) signaling pathway. Results: In the SCI models both in vivo and in vitro, early intervention with eUb enhanced neuronal autophagy and inhibited mitochondrial apoptotic pathways, significantly mitigating SCI. Further studies had shown that this protective effect of eUb was mediated through its receptor, CXC chemokine receptor type 4 (CXCR4). Additionally, eUb-enhanced autophagy and antiapoptotic effects were possibly associated with inhibiting the PI3K/Akt/mTOR pathway. Conclusion In summary, the study demonstrates that early eUb intervention can enhance autophagy and inhibit mitochondrial apoptotic pathways via CXCR4, protecting neurons and promoting SCI repair.

Objective: Neuronal apoptosis is considered to be a critical process in spinal cord injury (SCI). Despite growing evidence of the antiapoptotic, anti-inflammatory, and modulation of ischemic injury tolerance effects of extracellular ubiquitin (eUb), existing studies have paid less attention to the impact of eUb in neurological injury disorders, particularly in SCI. This study aimed to investigate whether eUb can play a protective role in neurons, both in vitro and in vivo, and explores the underlying mechanisms. Methods: By utilizing an oxygen glucose deprivation cellular model and a SCI rat model, we firstly investigated the therapeutic effects of eUb on SCI and further explored its effects on neuronal autophagy and mitochondria-dependent apoptosis-related indicators, as well as the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mechanical target of rapamycin (mTOR) signaling pathway. Results: In the SCI models both in vivo and in vitro, early intervention with eUb enhanced neuronal autophagy and inhibited mitochondrial apoptotic pathways, significantly mitigating SCI. Further studies had shown that this protective effect of eUb was mediated through its receptor, CXC chemokine receptor type 4 (CXCR4). Additionally, eUb-enhanced autophagy and antiapoptotic effects were possibly associated with inhibiting the PI3K/Akt/mTOR pathway. Conclusion In summary, the study demonstrates that early eUb intervention can enhance autophagy and inhibit mitochondrial apoptotic pathways via CXCR4, protecting neurons and promoting SCI repair.