Objective:To analyze the sequencing results, protein structure model, and impact of mutations on the dynamic stability of glycosyltransferase (GTA) in a case with Aw26 blood group subtype.Methods:ABO phenotype was determined by serological testing (anti-A, anti-B, anti-H, and reverse typing). Potential variant of the ABO gene was identified by Sanger sequencing, and the haploid sequence of the variant site was analyzed by TOPOT-A cloning. Molecular models of the GTA was generated by PyMol, and 100-ns molecular dynamics (MD) was simulated with GROMACS software to assess the conformational stability using root mean square deviation (RMSD), radius of gyration (Rg), solvent-accessible surface area (SASA), hydrogen bonding, and binding free energy.Results:Serological assays confirmed the proband as an Aw subtype, whose genotype was identified as ABO*Aw.26/ABO*O.01.02 with variants including p. Pro156Leu, p. Arg176His and p. Pro354ArgfsTer23. Haploid sequencing validated the results of direct sequencing. Molecular modeling showed that the p. Arg176His variant could reduce water-mediated hydrogen bonds from six (wild-type) to one (variant). MD simulation revealed the wild type system could achieve equilibrium within 10 ns (mean RMSD ≈ 0.30 nm), whilst the mutant system required 50 ns to equilibrate and exhibited greater fluctuation (mean RMSD ≈ 0.40 nm). Root mean square fluctuation (RMSF) analysis confirmed significantly increased flexibility in the mutant′s N-terminal loop (residues 63-76). The mutant Rg displayed an expansion-contraction transition within 0 ~ 40 ns, and its SASA value has increased. The number of hydrogen bonds and binding energy of the mutant had decreased (wild-type: 5 to 8, binding energy: -11.53 kcal/mol; mutant: 2 to 5, binding energy: -8.52 kcal/mol). Conclusion:An Aw26 subtype was identified. The p. Arg176His and p. Pro354Argfs*23p variants could synergistically compromise the structural stability of GTA and its substrate binding capacity by disrupting the hydrogen-bond network, increasing local flexibility, and reducing the overall conformational stability.

OBJECTIVE: To analyze the sequencing results, protein structure model, and impact of mutations on the dynamic stability of glycosyltransferase (GTA) in a case with Aw26 blood group subtype. METHODS: ABO phenotype was determined by serological testing (anti-A, anti-B, anti-H, and reverse typing). Potential variant of the ABO gene was identified by Sanger sequencing, and the haploid sequence of the variant site was analyzed by TOPOT-A cloning. Molecular models of the GTA was generated by PyMol, and 100-ns molecular dynamics (MD) was simulated with GROMACS software to assess the conformational stability using root mean square deviation (RMSD), radius of gyration (Rg), solvent-accessible surface area (SASA), hydrogen bonding, and binding free energy. RESULTS: Serological assays confirmed the proband as an Aw subtype, whose genotype was identified as ABO*Aw.26/ABO*O.01.02 with variants including p.Pro156Leu, p.Arg176His and p.Pro354ArgfsTer23. Haploid sequencing validated the results of direct sequencing. Molecular modeling showed that the p.Arg176His variant could reduce water-mediated hydrogen bonds from six (wild-type) to one (variant). MD simulation revealed the wild type system could achieve equilibrium within 10 ns (mean RMSD ≈ 0.30 nm), whilst the mutant system required 50 ns to equilibrate and exhibited greater fluctuation (mean RMSD ≈ 0.40 nm). Root mean square fluctuation (RMSF) analysis confirmed significantly increased flexibility in the mutant's N-terminal loop (residues 63-76). The mutant Rg displayed an expansion-contraction transition within 0 ~ 40 ns, and its SASA value has increased. The number of hydrogen bonds and binding energy of the mutant had decreased (wild-type: 5 to 8, binding energy: -11.53 kcal/mol; mutant: 2 to 5, binding energy:-8.52 kcal/mol). CONCLUSION An Aw26 subtype was identified. The p.Arg176His and p.Pro354Argfs*23p variants could synergistically compromise the structural stability of GTA and its substrate binding capacity by disrupting the hydrogen-bond network, increasing local flexibility, and reducing the overall conformational stability.
ABO Blood-Group System/chemistry* ; Humans ; Molecular Dynamics Simulation ; Models, Molecular ; Mutation ; Genotype ; Protein Conformation ; Glycosyltransferases/chemistry* ; Male

Objective:To investigate the impact of immunosuppressive therapy on the severity of SARS-CoV-2 infection and cytokine levels in pediatric patients with kidney diseases.Methods:A retrospective analysis was conducted on the clinical data of 40 hospitalized pediatric patients who were diagnosed with SARS-CoV-2 infection at the 900th Hospital of PLA Joint Logistic Support Force from December 2022 to February 2023. Based on their immunosuppressive status prior to SARS-CoV-2 infection, these patients were categorized into immunosuppressive group and non-immunosuppressive group. Independent sample t-tests, Mann-Whitney U tests, and χ2 test were employed to compare the clinical baseline characteristics and laboratory data, the severity of SARS-CoV-2 infection, and the levels of cytokines between the 2 groups. Results:Among the 40 patients, 11 were in the immunosuppressive group (aged 13 (8, 14) years, 9 males and 2 females) and 29 in the non-immunosuppressive group (aged 2 (1, 4) years, 15 males and 14 females). In the immunosuppressive group, 2 were asymptomatic cases, 8 were mild cases, and 1 was moderate case, and there was no severe or critical cases. In the non-immunosuppressive group, 8 were mild cases, 5 were moderate, 15 were severe cases, 1 was critical case, and no asymptomatic cases. The underlying diseases in the immunosuppressive group included nephrotic syndrome (6 cases), IgA vasculitis nephritis (2 cases), lupus nephritis (1 case), post-renal transplantation (1 case), and renal failure (1 case), with a mean total immunosuppression score (TIS) of (3.6±1.4) points. In the non-immunosuppressive group, 2 patients had a history of epilepsy, and the remaining 27 cases had no underlying conditions, all with TIS scores of 0. Compared to the children in the non-immunosuppressive group, those in the immunosuppressive group were more likely to exhibit asymptomatic or mild infection, with lower risks of severe disease, cytokine storm, fever, and cough, but a higher risk of fatigue ( OR=1.22, 2.66, 0.48, 0.12, 0.12, 0.13, 1.22; 95% CI 0.93-1.62, 0.99-7.15, 0.33-0.70, 0.03-0.57, 0.03-0.57, 0.03-0.65, 0.93-1.62; all P<0.05). The levels of cytokine IL-6, interferon-α and interferon-γ in the immunosuppressive group were all lower than those in the non-immunosuppressive group ( Z=2.23, 2.51, 2.92, respectively; all P<0.05). Conclusion:Pediatric patients with kidney diseases receiving appropriate immunosuppressive therapy may mitigate the severity of SARS-CoV-2 infection by suppressing the expression of cytokines.

Objective:To analyze the sequencing results, protein structure model, and impact of mutations on the dynamic stability of glycosyltransferase (GTA) in a case with Aw26 blood group subtype.Methods:ABO phenotype was determined by serological testing (anti-A, anti-B, anti-H, and reverse typing). Potential variant of the ABO gene was identified by Sanger sequencing, and the haploid sequence of the variant site was analyzed by TOPOT-A cloning. Molecular models of the GTA was generated by PyMol, and 100-ns molecular dynamics (MD) was simulated with GROMACS software to assess the conformational stability using root mean square deviation (RMSD), radius of gyration (Rg), solvent-accessible surface area (SASA), hydrogen bonding, and binding free energy.Results:Serological assays confirmed the proband as an Aw subtype, whose genotype was identified as ABO*Aw.26/ABO*O.01.02 with variants including p. Pro156Leu, p. Arg176His and p. Pro354ArgfsTer23. Haploid sequencing validated the results of direct sequencing. Molecular modeling showed that the p. Arg176His variant could reduce water-mediated hydrogen bonds from six (wild-type) to one (variant). MD simulation revealed the wild type system could achieve equilibrium within 10 ns (mean RMSD ≈ 0.30 nm), whilst the mutant system required 50 ns to equilibrate and exhibited greater fluctuation (mean RMSD ≈ 0.40 nm). Root mean square fluctuation (RMSF) analysis confirmed significantly increased flexibility in the mutant′s N-terminal loop (residues 63-76). The mutant Rg displayed an expansion-contraction transition within 0 ~ 40 ns, and its SASA value has increased. The number of hydrogen bonds and binding energy of the mutant had decreased (wild-type: 5 to 8, binding energy: -11.53 kcal/mol; mutant: 2 to 5, binding energy: -8.52 kcal/mol). Conclusion:An Aw26 subtype was identified. The p. Arg176His and p. Pro354Argfs*23p variants could synergistically compromise the structural stability of GTA and its substrate binding capacity by disrupting the hydrogen-bond network, increasing local flexibility, and reducing the overall conformational stability.

Objective:To investigate the impact of immunosuppressive therapy on the severity of SARS-CoV-2 infection and cytokine levels in pediatric patients with kidney diseases.Methods:A retrospective analysis was conducted on the clinical data of 40 hospitalized pediatric patients who were diagnosed with SARS-CoV-2 infection at the 900th Hospital of PLA Joint Logistic Support Force from December 2022 to February 2023. Based on their immunosuppressive status prior to SARS-CoV-2 infection, these patients were categorized into immunosuppressive group and non-immunosuppressive group. Independent sample t-tests, Mann-Whitney U tests, and χ2 test were employed to compare the clinical baseline characteristics and laboratory data, the severity of SARS-CoV-2 infection, and the levels of cytokines between the 2 groups. Results:Among the 40 patients, 11 were in the immunosuppressive group (aged 13 (8, 14) years, 9 males and 2 females) and 29 in the non-immunosuppressive group (aged 2 (1, 4) years, 15 males and 14 females). In the immunosuppressive group, 2 were asymptomatic cases, 8 were mild cases, and 1 was moderate case, and there was no severe or critical cases. In the non-immunosuppressive group, 8 were mild cases, 5 were moderate, 15 were severe cases, 1 was critical case, and no asymptomatic cases. The underlying diseases in the immunosuppressive group included nephrotic syndrome (6 cases), IgA vasculitis nephritis (2 cases), lupus nephritis (1 case), post-renal transplantation (1 case), and renal failure (1 case), with a mean total immunosuppression score (TIS) of (3.6±1.4) points. In the non-immunosuppressive group, 2 patients had a history of epilepsy, and the remaining 27 cases had no underlying conditions, all with TIS scores of 0. Compared to the children in the non-immunosuppressive group, those in the immunosuppressive group were more likely to exhibit asymptomatic or mild infection, with lower risks of severe disease, cytokine storm, fever, and cough, but a higher risk of fatigue ( OR=1.22, 2.66, 0.48, 0.12, 0.12, 0.13, 1.22; 95% CI 0.93-1.62, 0.99-7.15, 0.33-0.70, 0.03-0.57, 0.03-0.57, 0.03-0.65, 0.93-1.62; all P<0.05). The levels of cytokine IL-6, interferon-α and interferon-γ in the immunosuppressive group were all lower than those in the non-immunosuppressive group ( Z=2.23, 2.51, 2.92, respectively; all P<0.05). Conclusion:Pediatric patients with kidney diseases receiving appropriate immunosuppressive therapy may mitigate the severity of SARS-CoV-2 infection by suppressing the expression of cytokines.

OBJECTIVE To investigate the inhibitory effects of formononetin on lipopolysaccharide （LPS）-induced apoptosis and inflammatory response in alveolar epithelial cells through phosphoinositide 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway. METHODS Human lung cancer alveolar basal epithelial cells A549 were cultured in vitro and divided into control group （no intervention）， model group （1 μg/mL LPS）， different concentrations of formononetin groups （1 μg/mL LPS+6.25， 12.5， 25， 50 μmol/L formononetin）. The levels of inflammatory factors （interleukin-8， tumor necrosis factor-α） and cell viability were detected in each group. Another A549 cells were divided into control group， model group （1 μg/mL LPS）， LPS+25 group （1 μg/mL LPS+25 μmol/L formononetin）， inhibitor group （1 μg/mL LPS+20 μmol/L LY294002）， formononetin+inhibitor group （1 μg/mL LPS+25 μmol/L formononetin+20 μmol/L LY294002） and formononetin+activator group （1 μg/mL LPS+25 μmol/L formononetin+ 10 μmol/L SC79）. The secretion levels and mRNA expressions of inflammatory factors， cell apoptosis， and expressions of the key proteins of PI3K/Akt signaling pathway were detected in each group. RESULTS Compared with model group， the levels of inflammatory factors were decreased significantly after the intervention of 25 μmol/L of formononetin， and the cell viability was increased significantly （P＜0.05）. Compared with the control group， the secretion levels and mRNA expressions of inflammatory factors， apoptotic rate， and relative expressions of phosphorylated Akt and phosphorylated PI3K of the model group were increased significantly （P＜0.05）. Compared with the model group， the above indexes of the LPS+25 group and the inhibitor group were decreased significantly （P＜0.05）. Compared with the LPS+25 group， the above indicators of formononetin+inhibitor group were further decreased， while those of formononetin+activator group were increased significantly （P＜0.05）. CONCLUSIONS Formononetin can inhibit LPS-induced epithelial cell apoptosis and improve inflammatory response， and the mechanism may be related to the inhibition of the PI3K/Akt signaling pathway.

Macrolide and corticosteroid resistance has been reported in patients with Mycoplasma pneumoniae (MP) pneumonia (MPP). MP clearance is difficult to achieve through antibiotic treatment in sensitive patients with severe MPP (SMPP). SMPP in children might progress to airway remodeling and even bronchiolitis/bronchitis obliterans. Therefore, identifying serum biomarkers that indicate MPP progression and exploring new targeted drugs for SMPP treatment require urgency. In this study, serum samples were collected from patients with general MPP (GMPP) and SMPP to conduct proteomics profiling. The Fc fragment of the IgG-binding protein (FCGBP) was identified as the most promising indicator of SMPP. Biological enrichment analysis indicated uncontrolled inflammation in SMPP. ELISA results proved that the FCGBP level in patients with SMPP was substantially higher than that in patients with GMPP. Furthermore, the FCGBP levels showed a decreasing trend in patients with GMPP but the opposite trend in patients with SMPP during disease progression. Connectivity map analyses identified 25 possible targeted drugs for SMPP treatment. Among them, a mechanistic target of rapamycin kinase (mTOR) inhibitor, which is a macrolide compound and a cell proliferation inhibitor, was the most promising candidate for targeting SMPP. To our knowledge, this study was the first proteomics-based characterization of patients with SMPP and GMPP.
Biomarkers ; Carrier Proteins ; Child ; Humans ; Immunoglobulin Fc Fragments ; Immunoglobulin G ; Macrolides ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma/drug therapy* ; Proteomics

INTRODUCTION: Singapore has had three medical schools since 2013. We undertook a cross-sectional quantitative national survey to determine the financial impact of medical education on medical students in Singapore. METHODS: All 1,829 medical students in Singapore were invited to participate in this study. Information on demographics, financial aid utilisation and outside work was collected and analysed. RESULTS: 1,241 (67.9%) of 1,829 students participated in the survey. While the overall proportion of students from households with monthly incomes < SGD 3,000 was only 21.2% compared to the national figure of 31.4%, 85.4% of medical students expected to graduate with debts > SGD 75,000. There were significant differences in per capita incomes among the schools, with 54.5%, 23.3% and 7.8% of Duke-NUS Medical School (Duke-NUS), NUS Yong Loo Lin School of Medicine (NUS Medicine) and Lee Kong Chian School of Medicine (LKCMedicine) students, respectively, reporting a per capita income of < SGD 1,000 (p < 0.001). There were significant differences in financial support: 75.0%, 34.1% and 38.8% of Duke-NUS, NUS Medicine and LKCMedicine students, respectively, received financial aid (p < 0.001). The top reasons for not applying for aid included a troublesome application process (21.4%) and the perception that it would be too difficult to obtain (21.0%). CONCLUSION Students in the three medical schools in Singapore differ in their financial needs and levels of financial support received. A national approach to funding medical education may be needed to ensure that financial burdens do not hamper the optimal training of doctors for Singapore's future.
Cross-Sectional Studies ; Financial Stress ; Humans ; Schools, Medical ; Singapore ; Students, Medical ; Surveys and Questionnaires

Objective:To investigate the etiology of necrotizing pneumonia (NP) in children and the clinical characteristics of NP caused by different pathogens in China.Methods:A retrospective, case-control study was performed in children with NP who were admitted to 13 hospitals in China from January 2008 to December 2019. The demographic and clinical information, laboratory data, etiological and radiological findings were analyzed. The data were divided into three groups based on the following years: 2008-2011, 2012-2015 and 2016-2019, and the distribution characteristics of the pathogens in different period were compared. Meanwhile, the pathogens of pediatric NP in the southern and northern China were compared. And the clinical characteristics of the Mycoplasma pneumoniae (MP) NP and the bacterial NP were also compared. T-test or Mann-Whitney nonparametric test was used for comparison of numerical variables, and χ 2 test was used for categorical variables. Results:A total of 494 children with NP were enrolled, the median ages were 4.7 (0.1-15.3) years, including 272 boys and 222 girls. Among these patients, pathogens were identified in 347 cases and the pathogen was unclear in the remaining 147 cases. The main pathogens were MP (238 cases), Streptococcus pneumoniae (SP) (61 cases), Staphylococcus aureus (SA) (51 cases), Pseudomonas aeruginosa (13 cases), Haemophilus influenzae (10 cases), adenovirus (10 cases), and influenza virus A (7 cases), respectively. MP was the most common pathogen in all three periods and the proportion increased yearly. The proportion of MP in 2016-2019 was significantly higher than that in 2012-2015 (52.1% (197/378) vs. 36.8% (32/87), χ 2= 6.654, P=0.010), while there was no significant difference in the proportion of MP in 2012-2015 and that in 2008-2011 (36.8% (32/87) vs. 31.0% (9/29), χ2=0.314, P=0.575).Regarding the regional distribution, 342 cases were in the southern China and 152 in the northern China. Also, MP was the most common pathogen in both regions, but the proportion of MP was higher and the proportion of SP was lower in the north than those in the south (60.5% (92/152) vs. 42.7% (146/342), χ 2=13.409, P<0.010; 7.9% (12/152) vs. 14.3% (49/342), χ 2= 4.023, P=0.045). Comparing the clinical characteristics of different pathogens, we found that fever and cough were the common symptoms in both single MP and single bacterial groups, but chest pain was more common (17.0% (34/200) vs. 6.1% (6/98), χ 2=6.697, P=0.010) while shortness of breath and wheezing were less common in MP group (16.0% (32/200) vs. 60.2% (59/98), χ 2=60.688, P<0.01; 4.5% (9/200) vs. 21.4% (21/98), χ 2=20.819, P<0.01, respectively). The white blood cell count, C-reactive protein and procalcitonin in the bacterial group were significantly higher than those in the MP group (14.7 (1.0-67.1)×10 9/L vs. 10.5 (2.5-32.2)×10 9/L, 122.5 (0.5-277.3) mg/L vs. 51.4 (0.5-200.0) g/L, 2.13 (0.05-100.00) μg/L vs. 0.24 (0.01-18.85) μg/L, Z=-3.719, -5.901 and -7.765, all P<0.01). Conclusions:The prevalence of pediatric NP in China shows an increasing trend during the past years. MP, SP and SA are the main pathogens of NP, and the most common clinical symptoms are fever and cough. The WBC count, C-reactive protein and procalcitonin in bacterial NP are significantly higher than those caused by MP.

Objective To investigate the effect of piR-9994 on the biological behavior of gastric cancer cells and its possible mechanism. Methods The expression of piR-9994 in gastric cancer cell lines (MGC803 and AGS) and normal gastric epithelial cells (GES-1) were detected by qRT-PCR. MGC803 cell line with piR-9994 overexpression and knockdown were constructed. The effects of piR-9994 expression changes on cell proliferation were detected by MTT and clone formation assay. The scratch wound healing assay and Transwell invasion assay were used to detect cell migration and invasion abilities. qRT-PCR and Western blot were used to detect cell proliferation and EMT-related genes expression. Results The expression level of piR-9994 in MGC803 cells was significantly higher than that in normal gastric epithelial cell line GES-1 (P < 0.05). The overexpression of piR-9994 promoted the proliferation, invasion and metastasis of gastric cancer cells, while piR-9994 knockdown had the opposite effect. piR-9994 expression was closely related to cell cycle, especially in S phase. The overexpression of piR-9994 promoted the expression of proliferation-related genes PCNA, CCND1 and Bcl-2, inhibited the expression of apoptosis gene C-PARP, and promoted the expression of EMT-related genes N-cadherin, MMP7, Twist and Vimentin; while piR-9994 knockdown had the opposite effect. Conclusion Abnormal expression of piR-9994 affects the proliferation, invasion, metastasis and EMT process of gastric cancer cells. piR-9994 may be a new biomarker and therapeutic target for gastric cancer.