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

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.

ObjectiveTo evaluate the effects of Wuhua herbal tea on chronic unpredictable mild stress (CUMS)-induced depression and explore its mechanism of action in combating depression.MethodsWe tested the antidepressant effects of Wuhua herbal tea in a rat model of CUMS-induced depression using fluoxetine as a positive control. The rats were divided into four groups: control group, model group, fluoxetine group, and Wuhua herbal tea group. The rats underwent body weight measurements, sucrose preference test, and open-field test. Enzyme-linked immunosorbent assay kits were used to detect the serum levels of serotonin, dopamine, adrenocorticotropic hormone (ACTH), corticosterone, norepinephrine, and interleukin-6. Intergroup comparisons and detection of brain-derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB), Janus kinase 2 (JAK2), and signal transducer and activator of transcription 3 (STAT3) mRNA expression in the hippocampus were performed using RT-PCR. Immunohistochemistry was used to identify the expression of phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) proteins in hippocampal paraffin sections of CUMS rats.ResultsCompared with the control group, the model group rats had depressive tendencies, exhibiting low vitality and interest in various behavioral indicators which were signs of despair. The Wuhua herbal tea group statistically increased the levels of serotonin and dopamine in the serum of CUMS rats to varying degrees (P = .015 and P = .002); reduced serum levels of ACTH, corticosterone, norepinephrine, and interleukin-6 (all P .05); and decreased mRNA expression of BDNF, CREB, JAK2, and STAT3 in the hippocampus (all P .05); and decreased p-STAT3 protein levels (P = .006).ConclusionWuhua herbal tea shows antidepressant potential in CUMS rats by modulating the HPA axis and inhibiting JAK2-STAT3 overactivation, alleviating neuroinflammation. It also restores BDNF-CREB pathway function, reducing depressive symptoms.

Background The senescence of alveolar type II epithelial cells is an important driving factor for the progression of silicotic fibrosis, and the regulatory effects of oxamate on the senescence of alveolar type II epithelial cells is still unclear. Objective To explore whether lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting senescence of alveolar type II epithelial cellsMethods This study was divided into two parts: in vivo experiments and in vitro experiments. In the first part, forty SPF C57BL/6J male mice were randomly divided into four groups with 10 in each group: control group, silicosis model group, low-dose oxamate treatment group, and high-dose oxamate treatment group. The silicotic mouse model was established by intratracheal instillation of 50 μL SiO₂ suspension (100 mg·mL⁻¹). The treatment models were prepared by intraperitoneal injection of 100 μL oxamate (225 mmol·L⁻¹ and 1125 mmol·L⁻¹). In the second part, induction of MLE-12 mouse alveolar type II epithelial cells was conducted with SiO₂. The in vitro experimental groups were ① SiO₂ induction groups: control group, 50 μg·mL⁻¹ SiO₂ group, 100 μg·mL⁻¹ SiO₂ group, and 200 μg·mL⁻¹ SiO₂ group, and ② oxamate treatment groups: control group, SiO₂ group (100 μg·mL⁻¹), low-dose oxamate (25 mmol·L⁻¹) treatment group, and high-dose oxamate (50 mmol·L⁻¹) treatment group. Pathological morphology of lung tissues was evaluated after hematoxylin-eosin (HE) staining; deposition of collagen in lung tissues was evaluated after sirius red staining; positive co-expression of prosurfactant protein C (Pro-SPC) and β-galactosidase was detected by immunofluorescence staining; positive expression of β-galactosidase in MLE-12 cells was detected by immunofluorescence staining. The protein expression levels of collagen type I (CoL I), fibronectin1 (FN1), hexokinase 2 (HK2), pyruvate kinase isozyme type M2 (PKM2), lactate dehydrogenase A (LDHA), p-ataxia telangiectasia and Rad3-related kinase (ATR), and cyclin-dependent kinase inhibitors p21, and p16 were detected by Western blotting. Results Compared with the control group, the protein expression levels of HK2, PKM2, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group and the SiO₂-induced MLE-12 cells (P＜0.05). The in vivo studies showed that, compared with the control group, the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the protein expression levels of CoL I, FN1, LDHA, p-ATR, p21, and p16 were significantly upregulated in the silicosis model group (P＜0.05). Compared with the silicosis model group, the oxamate treatment groups showed significant downregulation of the silicon nodule area, the collagen deposition area, the proportion of β-galactosidase positive cells, and the the CoL I, FN1, LDHA, p-ATR, p21, and p16 protein expression levels, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). The in vitro studies showed that, compared with the control group, the proportion of β-galactosidase positive cells and the protein expression levels of p-ATR, p21, and p16 were significantly upregulated in the SiO₂-induced group (P＜0.05). Compared with the SiO₂ group, the proportion of β-galactosidase positive cells and the LDHA, p-ATR, p21 and p16 protein expression levels were significantly downregulated in the oxamate treatment groups, and the high-dose oxamate treatment group showed a higher efficacy on these indicators than the low-dose oxamate treatment group (P＜0.05). Conclusion Lactate dehydrogenase inhibitor oxamate can alleviate silicotic fibrosis in mice by inhibiting the senescence of alveolar type II epithelial cells.