OBJECTIVE To investigate the apoptosis-inducing effect of esculetin （Esc） on acute myeloid leukemia （AML） HL-60 cells by regulating the protein kinase B （AKT）/S-phase kinase-associated protein 2 （SKP2）/MutT homolog 1 （MTH1） pathway. METHODS AML HL-60 cells were randomly divided into control group （routine culture）， Esc low-concentration group （L-Esc group， 25 μmol/L Esc）， Esc medium-concentration group （M-Esc group， 50 μmol/L Esc）， Esc high-concentration group （H-Esc group， 100 μmol/L Esc）， and high-concentration of Esc+ SC79 （AKT agonist） group （100 μmol/L Esc+5 μmol/L SC79）. Cell proliferation in each group was detected by MTT assay and colony formation assay. The level of reactive oxygen species （ROS） in cells was measured by using the CM-H2DCFDA fluorescent probe. Cell apoptosis was analyzed by flow cytometry. Western blot assay was performed to detect the expression levels of apoptosis-related proteins [B-cell lymphoma 2 （Bcl-2）， Bcl-2-associated X protein （Bax）， cleaved caspase-3]， AKT/SKP2/MTH1 pathway-related proteins （p-AKT， AKT， SKP2， MTH1）， along with the upstream and downstream proteins of AKT phosphatidylinositol 3-kinase （PI3K）， cyclin-dependent kinase inhibitor 1 （P21） and cyclin-dependent kinase inhibitor 1B （P27）. RESULTS Compared with control group， the cell viability， colony number， and the phosphorylation levels of AKT and PI3K proteins as well as protein expressions of SKP2， MTH1 and Bcl-2 were significantly decreased （P＜0.05）， while ROS level， apoptosis rate， and the expression levels of Bax， cleaved caspase-3， P21 and P27 proteins were significantly increased （P＜0.05）. Moreover， the effects of Esc exhibited concentration-dependence （P＜0.05）. Compared with H-Esc group， above indexes of high-concentration of Esc+ SC79 group were reversed significantly （P＜0.05）. CONCLUSIONS Esc may promote massive ROS production and induce activation of apoptosis in HL-60 cells by inhibiting the AKT/SKP2/MTH1 pathway， thus inhibiting the proliferation of HL-60 cells.

Objective To explore the impact of meteorological factors on the incidence of scarlet fever in Xicheng District of Beijing, and to provide a scientific basis for formulating targeted prevention and control measures. Methods Daily scarlet fever incidence data and corresponding meteorological data from 2010 to 2019 in Xicheng District of Beijing were collected. Using year, month, and day of the week as time-stratified variables, a conditional logistic regression model with a time-stratified case-crossover design was employed to analyze the impact of different meteorological factors on the number of scarlet fever cases in Xicheng District, while controlling for long-term trends, seasonality and other confounding factors. Results From 2010 to 2019, a total of 3,195 cases of scarlet fever were reported in Xicheng District, with an average annual incidence rate of 24.17/100 000. The overall trend showed fluctuating decline, during which three incidence peaks occurred, with the highest incidence rate observed in 2011. No severe or fatal cases were reported. The incidence of scarlet fever exhibited a distinct seasonal bimodal distribution, primarily concentrated between April to June and November to January of the following year. The conditional logistic regression results showed that the average relative humidity and average temperature were positively correlated with scarlet fever cases (β=0.0203, β=0.0613, P＜0.001), while the average vapor pressure was negatively correlated with scarlet fever cases (β=-0.1468, P＜0.001). Increases average relative humidity and average temperature were risk factors for scarlet fever incidence (OR=1.0205，95%CI=1.0150 -1.0261；OR=1.0632，95%CI=1.0379 -1.0891). For every 1.00% increase in average relative humidity, the number of scarlet fever cases increased by 2.05% (1.50% –2.61%). Similarly, for every 1^。C rise in average temperature, the number of cases increased by 6.32% (3.79% – 8.91%). In contrast, an increase in average vapor pressure had a protective effect against scarlet fever (OR=0.8635,95%CI=0.8392-0.8885). For every 1 hPa increase in average vapor pressure, the number of scarlet fever cases decreased by 13.65% (11.15%–16.08%). Conclusion The average relative humidity, average temperature and average vapor pressure are the primary meteorological factors influencing the incidence of scarlet fever in Xicheng District of Beijing, and can be utilized as indicators for the prevention, control, surveillance and early warning of scarlet fever.

Objective To compare the epidemic characteristics of seasonal influenza in Xicheng District, Beijing, between 2018-2019 and 2023-2024. Methods The present study was a cross-sectional study. The influenza cases and etiological surveillance data of Xicheng District, Beijing in 2018-2019 and 2023-2024, respectively, were analyzed to study the differences in the incidence rate of influenza cases in different ages, regions, occupations, and etiological detection results during the four years. Results There were significant differences in the incidence rates of influenza (χ²=37 038.65，P＜0.05) and the interval between visits (Z=468.692, P < 0.05) in 2018, 2019, 2023 and 2024. There were statistically significant differences in the incidence rates of influenza among different age groups, streets, and occupations during the four years (Z=75.646, 209.276, 72.132, 361.176, 43.570, all P < 0.05). Compared with 2018-2019, the growth rate of influenza in Xicheng District, Beijing in 2023-2024 was the highest in the 15-24 year-old group, Tianqiao Street, and housework and unemployed people. The difference in the interval between influenza visits among people of different age groups during these 4 years was statistically significant (P < 0.05). The growth rate of the interval between influenza visits in Xicheng District, Beijing in 2023-2024 was the highest in the 15-24 year-old group, while it showed a decrease in the 0-4 year-old group. The etiology in 2018-2019 was mainly H1N1 and H3N2 subtypes, and in 2023-2024 it was mainly H3N2 subtype and influenza B, and the peak values of H1N1, H3N2 subtype and influenza B in 2023-2024 were all higher than those in 2018-2019. Conclusion During the epidemic period, non-medical interventions have changed the transmission mode, seasonal peak and subtype distribution of influenza virus. As the epidemic has eased, the pattern of influenza has gradually rebounded.

Tetrodotoxin（TTX）is a potent neurotoxin known for its specific sodium channel blocking effects, widely used in biomedical research. While TTX has been identified in various marine organisms, its true origin remains unclear, and the specific biosynthetic pathways are yet to be elucidated. The reported sources of TTX and the progress in research on TTX biosynthesis were summarized, with a focus on potential microbial sources of TTX, which could provide scientific reference for the production and biosynthesis studies of TTX.

ObjectiveTo study the mechanism of Huanglian Jiedutang （HLJDT） in treating mice with atherosclerosis （AS） by improving ferroptosis. MethodsA total of 10 SPF C57BL/6J mice were selected as a normal group， and 50 ApoE^-/- mice were randomly divided into five groups： model group， low-dose group of HLJDT， medium-dose group of HLJDT， high-dose group of HLJDT， and atorvastatin （ATV） group. ApoE^-/- mice were fed a high-fat diet for eight weeks to establish the AS model， and at the 9th week， they were given normal saline， low， medium， and high doses of HLJDT （3.9， 7.8， 15.6 g·kg^-1·d^-1）， and atorvastatin calcium tablets （0.01 g·kg^-1·d^-1）， respectively， for a total of eight weeks. The formation of aortic plaque in mice was observed by gross oil red O staining and Masson staining. The levels of total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C）， triglyceride （TG）， and high-density lipoprotein cholesterol （HDL-C） in blood fat were measured by the automatic biochemical analyzer， and the mitochondrial structure of the aorta was observed by transmission electron microscopy. The content of serum superoxide dismutase （SOD） in serum was detected by enzyme-linked immunosorbent assay （ELISA）. The content of reduced glutathione （GSH） in serum was detected by the microplate method， and that of malondialdehyde （MDA） in serum was detected by the TBA method. The protein expression of nuclear factor E₂-associated factor 2 （Nrf2）/glutathione peroxidase 4 （GPX4） signaling pathway was detected by Western blot. ResultsCompared with those of the normal group， the contents of TC， LDL-C， TG， HDL-C， and MDA in the serum and the aortic vascular plaque deposition of the model group were significantly increased （P<0.01）， while the expression levels of SOD and GSH in serum， as well as Nrf2， solute carrier family 7 member 11 （SLC7A11）， and GPX4 in aorta were significantly decreased （P<0.01）. Mice in the model group appeared mitochondrial fragmentation and vacuolation in the aorta， volume atrophy， mitochondrial crista reduction， or a loose and disorganized form. Compared with those in the model group， the aortic vascular plaque deposition was significantly decreased in the low-dose， medium-dose， and high-dose groups of HLJDT and ATV group， and the contents of serum TC， LDL-C， TG， and MDA in serum were significantly decreased （P<0.05， P<0.01）. The contents of serum SOD and GSH and the expression levels of Nrf2， SLC7A11， and GPX4 in the aorta were increased （P<0.05， P<0.01）， and the symptoms of aortic mitochondrial vacuolation were alleviated. The number of cristae was increased， and they were ordered neatly. ConclusionHLJDT can reduce aortic vascular plaque deposition， decrease blood lipid and MDA expression， increase SOD and GSH expression， and ameliorate the pathological changes of ferroptosis， the mechanism of which is related to the Nrf2/GPX4 signaling pathway.

ObjectiveTo observe the effects of Qingxin Jieyu granules （QXJYG） on FeCl₃-induced carotid artery thrombosis in rats and on the expression of thrombosis-related proteins tissue factor （TF） and tissue factor pathway inhibitor （TFPI） as well as the protein kinase B （Akt）/nuclear factor-κB （NF-κB） signaling pathway in EA.hy926 cells exposed to tumor necrosis factor-α （TNF-α）， thus preliminarily exploring the mechanism of QXJYG in inhibiting thrombosis. MethodsThirty-six SD rats were randomized into normal control， model， positive control （aspirin， 9 mg·kg^-1）， and low-， medium-， and high-dose （0.99， 1.98， 3.96 g·kg^-1， respectively） QXJYG groups （n=6）. The rats in the drug treatment groups were administrated with corresponding drugs， and those in the normal control group and model group were given an equal volume of distilled water. After 14 consecutive days of prophylactic gavage， the rat model of common carotid artery thrombosis was established with 45% FeCl₃ solution， and the blood vessels were collected and the wet weight of thrombus was weighed by an electronic balance （precision of 1/10 000）. The thrombosis in the common carotid artery of each group of rats was observed by hematoxylin-eosin staining. The plasma levels of von Willebrand factor （vWF）， platelet endothelial cell adhesion molecule-1 （PECAM-1）， tissue-type plasminogen activator （t-PA）， and plasminogen activator inhibitor-1 （PAI-1） were determined by enzyme-linked immunosorbent assay. An endothelial cell injury model was established by treating EA.hy926 human umbilical vein endothelial cells with TNF-α. The cell counting kit-8 method was used to screen the intervention concentrations of QXJYG. Western blot was employed to determine the protein levels of TF， TFPI， Akt， p-Akt， NF-κB p65， and p-NF-κB p65 in each group of cells. ResultsThe animal experiment showed that compared with the normal control group， the model group showed an increase in carotid artery thrombus weight （P<0.05）， with unclear vascular structure and extensive thrombosis in the lumen. In addition， the plasma levels of vWF， PECAM-1， and PAI-1 were elevated， while the t-PA level became lowered （P<0.05） in the model group. Compared with the model group， the aspirin and QXJYG groups showed reductions in the weight of FeCl₃-induced carotid artery thrombi （P<0.05） and thrombosis in the lumen， declines in plasma levels of PECAM-1 and PAI-1， and an elevation in the t-PA level （P<0.05）. Moreover， the QXJYG groups showed reductions in the plasma level of vWF （P<0.05）， which， however， had no significant difference between the aspirin group and the model group. The cell experiments indicated that 31.25， 62.5， 125， 250， 500 mg·L^-1 QXJYG had no effect on the viability of EA.hy926 cells. Therefore， 250， 500 mg·L^-1 QXJYG were selected as the intervention concentrations for subsequent experiments. Western blotting results showed that compared with the control group， the TNF-α stimulation downregulated the expression of TFPI （P<0.05）， upregulated the expression of TF， and increased the ratios of p-Akt/Akt and p-NF-κB p65/NF-κB p65 （P<0.05） in EA.hy926 cells. Compared with the model group， the intervention with QXJYG upregulated the expression of TFPI （P<0.05）， inhibited the expression of TF， and decreased the ratios of p-Akt/Akt and p-NF-κB p65/NF-κB p65 （P<0.05）. ConclusionQXJYG has the effect of inhibiting thrombosis and regulating the expression of TF and TFPI in endothelial cells exposed to TNF-α by suppressing the abnormal activation of the Akt/NF-κB signaling pathway.

Objective To investigate the changes in eosinophil counts and the activation of microglial cells in the brain tissues of mice at different stages of Angiostrongylus cantonensis infection, and to examine the role of microglia in regulating the progression of angiostrongyliasis and unravel the possible molecular mechanisms. Methods Fifty BALB/c mice were randomly divided into the control group and the 7-d, 14-d, 21-day and 25-d infection groups, of 10 mice in each group. All mice in infection groups were infected with 30 stage III A. cantonensis larvae by gavage, and animals in the control group was given an equal amount of physiological saline. Five mice were collected from each of infection groups on days 7, 14, 21 d and 25 d post-infection, and 5 mice were collected from the control group on the day of oral gavage. The general and focal functional impairment was scored using the Clark scoring method to assess the degree of mouse neurological impairment. Five mice from each of infection groups were sacrificed on days 7, 14, 21 d and 25 d post-infection, and 5 mice from the control group were sacrificed on the day of oral gavage. Mouse brain tissues were sampled, and the pathological changes of brain tissues were dynamically observed using hematoxylin and eosin (HE) staining. Immunofluorescence staining with eosinophilic cationic protein (ECP) and ionized calcium binding adaptor molecule 1 (Iba1) was used to assess the degree of eosinophil infiltration and the counts of microglial cells in mouse brain tissues in each group, and the morphological parameters of microglial cells (skeleton analysis and fractal analysis) were quantified by using Image J software to determine the morphological changes of microglial cells. In addition, the expression of M1 microglia markers Fcγ receptor III (Fcgr3), Fcγ receptor IIb (Fcgr2b) and CD86 antigen (Cd86), M2 microglia markers Arginase 1 (Arg1), macrophage mannose receptor C-type 1 (Mrc1), chitinase-like 3 (Chil3), and phagocytosis genes myeloid cell triggering receptor expressed on myeloid cells 2 (Trem2), CD68 antigen (Cd68), and apolipoprotein E (Apoe) was quantified using real-time quantitative reverse transcription PCR (RT-qPCR) assay in the mouse cerebral cortex of mice post-infection. Results A large number of A. cantonensis larvae were seen on the mouse meninges surface post-infection, and many neuronal nuclei were crumpled and deeply stained, with a large number of bleeding points in the meninges. The median Clark scores of mouse general functional impairment were 0 (interquartile range, 0), 0 (interquartile range, 0.5), 6 (interquartile range, 1.0), 14 (interquartile range, 8.5) points and 20 (interquartile range, 9.0) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.45, P < 0.01), and the median Clark scores of mouse focal functional impairment were 0 (interquartile range, 0), 2 (interquartile range, 2.5), 7 (interquartile range, 3.0), 18 (interquartile range, 5.0) points and 25 (interquartile range, 6.5) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.72, P < 0.01). The mean scores of mice general and focal functional impairment were all higher in the infection groups than in the control group (all P values < 0.05). Immunofluorescence staining showed a significant difference in the eosinophil counts in mouse brain tissues among the five groups (F = 40.05, P < 0.000 1), and the eosinophil counts were significantly higher in mouse brain tissues in the 14-d (3.08 ± 0.78) and 21-d infection groups (5.97 ± 1.37) than in the control group (1.00 ± 0.28) (both P values < 0.05). Semi-quantitative analysis of microglia immunofluorescence showed a significant difference in the counts of microglial cells among the five groups (F = 17.66, P < 0.000 1), and higher Iba1 levels were detected in mouse brain tissues in 14-d (5.75 ± 1.28), 21-d (6.23 ± 1.89) and 25-d infection groups (3.70 ± 1.30) than in the control group (1.00 ± 0.30) (all P values < 0.05). Skeleton and fractal analyses showed that the branch length [(162.04 ± 34.10) μm vs. (395.37 ± 64.11) μm; t = 5.566, P < 0.05] and fractal dimension of microglial cells (1.30 ± 0.01 vs. 1.41 ± 0.03; t = 5.266, P < 0.05) were reduced in mouse brain tissues in the 21-d infection group relative to the control group. In addition, there were significant differences among the 5 groups in terms of M1 and M2 microglia markers Fcgr3 (F = 48.34, P < 0.05), Fcgr2b (F = 55.46, P < 0.05), Cd86 (F = 24.44, P < 0.05), Arg1 (F = 31.18, P < 0.05), Mrc1 (F = 15.42, P < 0.05) and Chil3 (F = 24.41, P < 0.05), as well as phagocytosis markers Trem2 (F = 21.19, P < 0.05), Cd68 (F = 43.95, P < 0.05) and Apoe (F = 7.12, P < 0.05) in mice brain tissues. Conclusions A. cantonensis infections may induce severe pathological injuries in mouse brain tissues that are characterized by massive eosinophil infiltration and persistent activation of microglia cells, thereby resulting in progressive deterioration of neurological functions.