Ornithine transcarbamylase(OTC)is a member of the transcarbamylase protein family,commonly found in the mitochondrial matrix of living organisms.It generally functions in a trimeric form and can catalyze the production of L-ornithine to L-citrulline.OTC is mainly expressed in the liver and intestines of mammals,playing an important role in the urea cycle and amino acid homeostasis.This article introduces the research progress of OTC genes,proteins,physiological functions,the impact of OTC deficiency on body health,and the diagnosis and treatment of OTC deficiency.

Objective To investigate the correlation between serum amyloid A(SAA)level and disease se-verity in children infected with severe acute respiratory syndrome coronavirus 2(COVID-19).Methods A to-tal of 116 children infected with COVID-19 admitted to the Department of Pediatrics of the hospital from De-cember 2022 to April 2023 were included and divided into asymptomatic/mild group and moderate/severe group according to the severity of the disease.In addition,65 healthy children who received health examination during the same period were selected as the control group.Serum SAA levels in children in acute stage and convalescent stage were detected by enzyme-linked immunosorbent assay.Results Compared with the control group,the serum SAA level in the children infected with COVID-19 was significantly increased in the acute stage(P＜0.05).The area under the receiver operating characteristic(ROC)curve(AUC)of SAA levels in the acute stage for diagnosing children with COVID-19 infection was 0.926(95％CI:0.886-0.966).In SARS-CoV-2 infected children,the SAA levels in the acute stage in the asymptomatic/mild group and the moderate/severe group were 2.71(1.29-10.86)mg/L and 37.78(18.58-92.62)mg/L,the differences were statistically significant between the two groups(Z=5.782,P＜0.001).In addition,serum SAA was pos-itively correlated with severity of SARS-CoV-2 by Spearman analysis(r=0.657,P＜0.001).Serum SAA lev-els were also significantly positively correlated with C-reactive protein(CRP),immunoglobulin(Ig)M,IgG,IgA and neutralizing antibody(NAb)in acute stage(P＜0.05).The AUC of serum SAA level in acute stage for diagnosing the moderate/severe children with SARS-CoV-2 was 0.889(95％CI:0.842-0.955),which was higher than that of CRP(P＜0.05).Compared with serum antibodies(IgM,IgG,IgA and NAb),the rate of serum SAA positive(≥5.55 mg/L)in children in acute stage was significantly higher(P＜0.05).The positive rate of serum SAA in convalescent children was significantly lower than that of serum antibody(P＜0.05).Conclusion Elevated serum SAA in acute phase is associated with increased risk of SARS-CoV-2 infec-tion and disease severity in children.Serum SAA is promising as a good biomarker for monitoring SARS-CoV-2 infection and severity in children.

Objective To explore the effects of evidence-based nursing combined with multi-dimensional health education on negative emotions and postoperative rehabilitation of patients undergoing elective surgery for cholecystolithiasis.Methods A total of 100 patients with cholecystolithiasis who underwent elective surgery in Yixing Traditional Chinese Hospital Medicine from September 2023 to August 2024 were selected.The patients were assigned to control group and observation group by PEMS3.1 for Windows completely random(two groups and multiple groups)program,with 50 cases in each group.The control group received routine nursing,and the observation group received evidence-based nursing combined with multidimensional health education on the basis of routine nursing.The intervention duration of the two groups was 7 days.Visual analogue scale(VAS)scores,negative emotions(self-rating anxiety scale[SAS]and self-rating depression scale[SDS]),postoperative complications,and postoperative rehabilitation were compared between the two groups.Results The VAS scores at 24 h and 72 h after surgery were lower than those at 6 h after surgery in both groups,especially in the observation group(P<0.05).The scores of SAS and SDS in both groups after intervention were significantly decreased compared with those before intervention,and the scores of negative emotions in the observation group after intervention were significantly lower than those in the control group(P<0.05).The total incidence of gastrointestinal discomfort,biliary fistula and wound infection/bleeding in the observation group was significantly lower than that in the control group(4.00%vs.18.00%,P<0.05).The time of getting out of bed,the time of anal exhaust,the time of resuming normal diet and the time of hospitalization in the observation group were significantly lower than those in the control group(P<0.05).Conclusion The combination of evidence-based nursing and multi-dimensional health education during perioperative period of cholecystolithiasis surgery can reduce postoperative pain,improve the positive attitude of treatment,reduce complications,and promote the recovery of the disease.

Checkpoint blockade immunotherapy has emerged as a transformative approach in cancer treatment by activating tumor-infiltrating T cells. However, the efficacy of PD-L1 blockade is restricted in "cold" tumors, which are characterized by low immunogenicity, presenting a challenge to immunotherapy. This study introduces an innovative strategy, utilizing cathepsin-cleavable N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-assisted combined photodynamic therapy (PDT) and PD-L1 degradation for the first time, effectively treating T cell-deficient tumors. The degradable main-chain polymer, conjugated with photosensitizer porphyrin, facilitates the accumulation of reactive oxygen species (ROS), triggering immunogenic cell death (ICD) and promoting cytotoxic T lymphocytes (CTLs) infiltration into tumors. Multivalent peptide antagonists of PD-L1 promote PD-L1 degradation in lysosomes through receptor crosslinking, overcoming the adaptive cycling of PD-L1 to the tumor cell surface. These findings demonstrate that polymer-assisted PDT and PD-L1 crosslinking degradation represent a potential novel strategy for anti-tumor immunotherapy, providing valuable tools for expanding immunotherapy applications in immunosuppressive cancers.

The continuous emergence of SARS-CoV-2 variants as well as other potential future coronavirus has challenged the effectiveness of current COVID-19 vaccines. Therefore, there remains a need for alternative antivirals that target processes less susceptible to mutations, such as the formation of six-helix bundle (6-HB) during the viral fusion step of host cell entry. In this study, a novel high-throughput screening (HTS) assay employing a yeast-two-hybrid (Y2H) system was established to identify inhibitors of HR1/HR2 interaction. The compound IMB-9C, which achieved single-digit micromolar inhibition of SARS-CoV-2 and its Omicron variants with low cytotoxicity, was selected. IMB-9C effectively blocks the HR1/HR2 interaction in vitro and inhibits SARS-CoV-2-S-mediated cell-cell fusion. It binds to both HR1 and HR2 through non-covalent interaction and influences the secondary structure of HR1/HR2 complex. In addition, virtual docking and site-mutagenesis results suggest that amino acid residues A930, I931, K933, T941, and L945 are critical for IMB-9C binding to HR1. Collectively, in this study, we have developed a novel screening method for HR1/HR2 interaction inhibitors and identified IMB-9C as a potential antiviral small molecule against COVID-19 and its variants.

Sigma-1 receptor (σ ₁R) has become a focus point of drug discovery for central nervous system (CNS) diseases. A series of novel 1-phenylethan-1-one O-(2-aminoethyl) oxime derivatives were synthesized. In vitro biological evaluation led to the identification of 1a, 14a, 15d and 16d as the most high-affinity (K _i < 4 nmol/L) and selective σ ₁R agonists. Among these, 15d, the most metabolically stable derivative exhibited high selectivity for σ ₁R in relation to σ ₂R and 52 other human targets. In addition to low CYP450 inhibition and induction, 15d also exhibited high brain permeability and excellent oral bioavailability. Importantly, 15d demonstrated effective antipsychotic potency, particularly for alleviating negative symptoms and improving cognitive impairment in experimental animal models, both of which are major challenges for schizophrenia treatment. Moreover, 15d produced no significant extrapyramidal symptoms, exhibiting superior pharmacological profiles in relation to current antipsychotic drugs. Mechanistically, 15d inhibited GSK3β and enhanced prefrontal BDNF expression and excitatory synaptic transmission in pyramidal neurons. Collectively, these in vivo proof-of-concept findings provide substantial experimental evidence to demonstrate that modulating σ ₁R represents a potential new therapeutic approach for schizophrenia. The novel chemical entity along with its favorable drug-like and pharmacological profile of 15d renders it a promising candidate for treating schizophrenia.

OBJECTIVES: Through the investigation of the microhardness and microstructure of permanent tooth enamel at various eruption stages during childhood, this research offers references for the early prevention of childhood dental caries. METHODS: Forty-five premolars extracted due to orthodontic reasons were collected and screened. These premolars were divided into three experimental groups according to the time since eruption: Group A (erupted for 0-1 year), Group B (erupted for 1-3 years), and Group C (erupted for 3-5 years). Additionally, the third molars that were extracted due to impaction and had not erupted were selected as the control group, with 15 teeth in each group. Samples were prepared, and the surface microhardness, microstructure, and elemental composition of the enamel were measured using Vickers microhardness tester, scanning electron microscope, and electron probe, respectively. RESULTS: Compared with that in the control group, the microhardness of enamel in groups A, B, and C increased with prolonged eruption time, the surface porosity structure decreased considerably, the contents of Na and Mg on the surface decreased, and that of F increased (P<0.05). CONCLUSIONS The microhardness and microstructure of enamel in permanent teeth at different stages vary. Permanent teeth are at a substantially higher risk of caries within one year after eruption, and early prevention should be emphasized.
Dental Enamel/ultrastructure* ; Humans ; Hardness ; Dental Caries/prevention & control* ; Microscopy, Electron, Scanning ; Tooth Eruption ; Bicuspid/chemistry* ; Dentition, Permanent ; Child ; Child, Preschool

S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg²⁺ improved the enzyme activity. The enzyme kinetic analysis showed that the K_m and k_cat/K_m of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Cysteine/biosynthesis* ; Mixed Function Oxygenases/metabolism* ; Schizosaccharomyces pombe Proteins/metabolism* ; Oxygenases/metabolism* ; Kinetics

Objective:To describe the distribution characteristics of alcohol consumption in adult twins in the Chinese National Twin Registry (CNTR), and further explore the influence of genetic factors on alcohol consumption in adult twins.Methods:The subjects of the study were twins registered by CNTR in 11 project areas across China from 2010 to 2018. A total of 56 966 twins (28 483 pairs) aged 18 years and above who answered questions about drinking behavior were included, and the random effect model was used to describe the population and regional distribution characteristics of alcohol consumption. Intra-pair analysis was performed to calculate the concordance rate and heritability of their alcohol consumption.Results:The age of all subjects was (36.6±12.0) years, and current drinkers accounted for 16.6% (9 461/56 966) of all subjects. In men, those aged 50-59 years, those in northern China, those living in rural area, those with low education level and those with high BMI, the proportions of current drinkers were higher. After excluding 468 pairs of twins who had stopped alcohol use and 21 764 pairs of twins who had no drink or had small amount drink, an intra-pair analysis was conducted in 4 929 pairs of same-sex twins, and found that the concordance rate of alcohol consumption was 64.0% (2 059/3 215) in monozygotic twins, and 52.6% (902/1 714) in dizygotic twins, the difference was significant ( P<0.001), and the heritability of alcohol consumption was 24.1% (95% CI: 18.9%- 29.3%). The further stratified analysis found that in southern men, the heritability was highest in those aged 40-49 years (36.1%, 95% CI: 21.6%-50.7%), while in northern men, the heritability was highest in those aged 50-59 years (34.2%, 95% CI: 18.1%-50.3%). Conclusions:In adult twins in China, there were population and regional differences in the distribution of alcohol consumption behavior, and alcohol consumption was influenced by genetic factors, and gender, age and region had potential modifying effects.

Objective:To investigate the changes in hepatic phase II detoxification enzymes and their mechanism in metabolic associated steatohepatitis (MASH) induced by a methionine-choline-deficient (MCD) diet in mice.Methods:Ten C57BL/6J mice were randomly divided into two groups, with five mice in each group, and fed with a control diet (NCD group) and a methionine-choline-deficient diet (MCD group) for four consecutive weeks to establish the MASH model in mice. Mice body weight was recorded weekly. Mice peripheral blood and liver tissue samples were collected after four weeks. The liver histopathological changes were observed by hematoxylin-eosin staining and Sirius red staining in liver tissue. The levels of plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglycerides were measured by an automatic biochemical analyzer. Triglyceride and total cholesterol were used to evaluate the lipid accumulation condition in the liver of mice with Oil red O staining. Real-time fluorescence quantitative PCR was used to detect the expression of liver inflammatory factors interleukin (IL)-1β and monocyte chemoattractant protein-1 (MCP-1) condition. Transcriptome sequencing and bioinformatics were used to analyze the changes in gene expression profiles in the liver of mice and screen differentially expressed genes. The expression conditions of phase Ⅱ detoxification enzymes glutathione S-transferase mu 4 (GSTM4), dihydronicotinamide riboside:quinone oxidoreductases (NQO-2), sulfotransferase 1β1 (SULT1β1), and uridine diphosphate glucuronosyltransferase 2 family, polypeptide A3(UGT2A3) were verified by real-time fluorescent quantitative PCR. Plasma malondialdehyde content, total antioxidant capacity (T-AOC), plasma and liver glutathione content were determined using commercial kits. The expression of nuclear factor E2-related factor 2 (Nrf2), GSTM4, and UGT1A6 was examined by Western blotting. The independent sample t-test was used for comparison between the groups. Results:The body weight of mice in the MCD group showed a gradual downward trend, while the body weight of mice in the NCD group did not change significantly following four weeks of different dietary feeding. The MCD group mice liver had yellow-white appearance with round edges. The liver/body mass index was significantly lower in the NCD group ( t=3.216, P<0.01). Hematoxylin-eosin staining showed that hepatocytes in the MCD group had an occurrence of fatty degeneration accompanied by inflammatory cell infiltration, with a higher NAFLD activity score (NAS) compared to the NCD group ( t=7.155, P<0.001). Sirius red staining showed that the the liver of the MCD group had mildly increased periportal fibers. Plasma biochemical tests indicated that plasma ALT, AST, and triglyceride levels were significantly higher in the MCD group than those in the NCD group ( t=8.920, P<0.001; t=6.696, P<0.001; t=3.904, P<0.01). Oil red O staining showed that a large number of lipid droplets accumulated in the liver tissue of the MCD group and were more severe than those in the NCD group ( t=7.405, P<0.001). The triglyceride content was significantly higher in the liver of the mice in the MCD group than that in the NCD group ( t=3.559, P<0.01), and the expression of inflammatory factors IL-1β and MCP-1 was significantly increased ( t=2.562 and 2.391, respectively, P<0.05). Transcriptome sequencing analysis showed that the expression profile of genes related to lipid metabolism was changed in the liver tissue of the mice in the MCD group. The expression of multiple phase Ⅱ detoxification enzymes was significantly downregulated. Real-time fluorescence quantitative PCR verification demonstrated that the expression of four phase Ⅱ detoxification enzymes GSTM4, NQO2, SUIL1β1, and UGT2A3 were significantly lower in the liver of the mice in the MCD group than those in the NCD group ( t=2.498, 3.570, 3.768, and 4.166, respectively, P<0.05). The detection kit showed that compared with the NCD group, the malondialdehyde content in the liver of mice in the MCD group increased ( t=3.601, P<0.01), while the plasma total glutathione ( t=11.93, P<0.001) and reduced glutathione levels were significantly reduced ( t=3.635, P<0.01). The total antioxidant capacity of the liver decreased ( t=2.872, P<0.05), and the total glutathione and reduced glutathione levels in the liver were significantly increased ( t=3.175 and 3.064, P<0.05). Western blotting showed that the expression of Nrf2, GSTM4, and UGT1A6 proteins was significantly lower in the MCD group than that in the NCD group ( t=3.385, 2.990, 2.168, P<0.05). Conclusions:The expressions of multiple phase Ⅱ detoxification enzymes and antioxidant capacity are reduced in the liver of MASH mice induced by the MCD diet, and its mechanism is related to the down-regulation of the expression of the upstream regulatory factor Nrf2 protein.