ObjectiveA middle cerebral artery occlusion (MCAO) mouse model is established by electrocoagulation of the middle cerebral artery. The study examines the mechanism by which exosomes (EXO) derived from human amniotic mesenchymal stem cells (hAMSCs) improve ischemic stroke and regulate neural ferroptosis-related injury. MethodsThirty-two SPF-grade male C57BL/6J mice aged 6 - 8 weeks were randomly divided into four groups (n=8 per group): sham group (Sham), model group (MCAO), MCAO plus normal saline group (MCAO+NaCl), and MCAO plus exosome group (MCAO+EXO). The mouse MCAO model was established by electrocoagulation of the middle cerebral artery. Mice in the Sham group underwent exposure of the middle cerebral artery without electrocoagulation. Twenty-four hours before MCAO induction, mice in the MCAO+EXO group received a tail vein injection of 100 μL of exosomes derived from the culture supernatant of hAMSCs at a concentration of 9.5×10¹¹ particles/mL. Mice in the MCAO+NaCl group were injected with an equal volume of normal saline via the tail vein. Twenty-four hours after model establishment, neurological deficits were evaluated using the Longa neurological deficit scoring system. Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining. Hematoxylin and eosin (HE) staining was performed to evaluate morphological changes of neurons in the ischemic brain regions. The contents of ferrous iron (Fe²⁺), malondialdehyde (MDA), total glutathione (total GSH), oxidized glutathione (GSSG), and reduced glutathione (GSH) in the infarct core and peri-infarct regions were determined using microcolorimetric assays to evaluate differences among groups. The mRNA expression levels of ferroptosis-related factors, including nuclear factor erythroid 2-related factor 2 (NRF2), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) in the infarct core and peri-infarct regions were measured by real-time quantitative PCR. Protein expression levels of NRF2, SLC7A11, and GPX4 in the infarct and peri-infarct regions of each group were analyzed by Western blotting. ResultsCompared with the MCAO group, the Longa neurological deficit score was significantly reduced in the MCAO+EXO group (P<0.01). Prominent cerebral infarction was observed in the MCAO group, whereas the infarct volume ratio was markedly decreased in the MCAO+EXO group compared with the MCAO group (P<0.001). Histopathological analysis revealed that mice in the MCAO group exhibited obvious neuronal damage, including cytoplasmic vacuolar degeneration, nuclear pyknosis and fragmentation, unclear nuclear structure, and disorganized neuronal arrangement, compared with the Sham group. In contrast, neurons in the MCAO+EXO group showed relatively preserved morphology, with intact cellular structures and large, regular nuclei located centrally within the cells. Biochemical analysis demonstrated that Fe²⁺ and MDA levels in the infarct core and peri-infarct regions were significantly increased in the MCAO group compared with the Sham group (P<0.001). These levels were significantly reduced in the MCAO+EXO group compared with the MCAO group (P<0.01). In addition, total glutathione (total GSH), oxidized glutathione (GSSG), and reduced glutathione (GSH) levels were markedly decreased in the MCAO group relative to the Sham group (P<0.01). Compared with the MCAO group, the MCAO+EXO group exhibited significantly increased levels of total GSH and GSH (P<0.001), while no significant change was observed in GSSG levels (P>0.05). Furthermore, both mRNA and protein expression levels of nuclear factor erythroid 2-related factor 2 (NRF2), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) were significantly downregulated in the MCAO group compared with the Sham group (P<0.01, P<0.001). In contrast, both mRNA and protein expression levels of NRF2, SLC7A11, and GPX4 were significantly upregulated in the MCAO+EXO group compared with the MCAO group (P<0.05). ConclusionIn the mouse MCAO model, tail vein injection of exosomes derived from hAMSCs can improve motor function, reduce infarct area, protect neuronal cell morphology, and reduce the degree of nerve injury. Exosomes may exert a protective effect by activating the NRF2/SLC7A11/GPX4 pathway and reducing ferroptosis in neuronal cells of MCAO model mice.

ObjectiveTo analyze scarlet fever surveillance data in Harbin City from 2010 to 2024, to preliminarily understand its incidence level and epidemiological characteristics, and to provide a scientific basis for the further formulation of effective prevention and control strategies. MethodsScarlet fever surveillance data for Harbin City from January 1, 2010 to December 31, 2024 were collected through the China Disease Prevention and Control Information System. Descriptive epidemiological analyses were conducted using incidence rates and constituent ratios. ResultsFrom 2010 to 2024, a total of 11 052 scarlet fever cases were reported in Harbin City, during the 15-year period, with an average annual reported incidence of 7.65/100 000. The overall annual incidence rate showed a fluctuating downward trend, with epidemic peaks occurring from April to July each year and from November to January of the following year. The age group of 0 to 9 years had the highest incidence rate at 6.47/100 000. The majority of cases were students (4 707 cases, 42.59%), children in nurseries and kindergartens(3 289 cases, 29.76%) and scattered children (2 941 cases, 26.61%), together accounting for 98.96% of all cases. The incidence ratio of male to female was 1.53∶1. The average annual incidence rate was 9.23/100 000 for males and 6.07/100 000 for females. Over the 15-year period, all 18 districts (counties) in Harbin City had reported cases. The top five areas with the highest average annual reported incidence of scarlet fever were Acheng District (14.45/100 000), Xiangfang District (12.73/100 000), Pingfang District (12.10/100 000), Bin County (10.29/100 000) and Daowai District (10.08/100 000). ConclusionFrom 2010 to 2024, the overall incidence of scarlet fever in Harbin City presented a downward trend. The disease prevailed mainly in spring-summer and autumn-winter, rather than year-round, with cases concentrated in densely populated districts and counties. Children and adolescents constituted the major affected population. The incidence was slightly higher in males, and school-age children accounted for a larger proportion than other age groups. Comprehensive preventive measures should focus on health education in key endemic areas, strengthen targeted protection for high-risk groups, and enhance epidemic surveillance and early warning.

Objective: To investigate the characteristics and risk factors of an outbreak of acute hemorrhagic conjunctivitis (AHC) in a boarding middle school in Guangdong Province, in order to provide a scientific evidence for effective prevention and control of campus AHC outbreaks. Methods: From September 1st to 28th 2023, case identification was conducted among 559 students and 60 faculty members using standardized definition. Descriptive analysis was conducted on the three distrubution patterns of the outbreak. Questionnaires were designed, and a case-control study was adopted to analyze the possible risk factors of the disease transmission. The propensity score matching (PSM) method was used to control the difference of baseline data. Results: A total of 269 cases of AHC were identified, with an attack rate of 43.46%. The pathogen was confirmed as Coxsackie virus A24 variant (CA24v). Among these, 264 cases were students (attack rate of 47.23%) and 5 were staff (attack rate of 8.33%). A total of 153 pairs of PSM were successfully matched. After PSM matching, there were no statistically significant differences in gender, grade and class between the case group and the control group ( χ 2=0.12, 5.41, 11.24, P >0.05). The results of multivariate Logistic regression analysis showed that middle school students whose towels contacted with others ( OR =1.81), and direct contact with other AHC cases recently ( OR =4.89) were more likely to have AHC; while wearing glasses ( OR =0.43) and frequent use of hand sanitizer ( OR = 0.37 ) were less likely to have AHC ( P <0.05). Conclusion The outbreak of AHC is caused by CA24v, demonstrating rapid spread and extensive impact within the school setting.

Crown lengthening is one of the common periodontal surgeries for the purposes of function,aesthetic and periodontal health.In recent years,with the continuous development of minimally invasive concept,flapless crown lengthening surgery has been re-ceiving increasing attention in clinical practice.With the help of laser,piezosurgery and other tools,flapless crown lengthening surgery is used to remove alveolar bone through gingival sulcus without open-flap approach and suture.This minimally invasive flapless ap-proach can avoid direct exposure of alveolar bone,and has the advantages of less bleeding,less trauma,fast healing,simple operation and high patients'comfort.The review demonstrates surgical methods,indication selection and clinical application results of flapless crown lengthening,aiming at providing reference for clinicians to carry out this novel technique.

Crown lengthening is one of the common periodontal surgeries for the purposes of function,aesthetic and periodontal health.In recent years,with the continuous development of minimally invasive concept,flapless crown lengthening surgery has been re-ceiving increasing attention in clinical practice.With the help of laser,piezosurgery and other tools,flapless crown lengthening surgery is used to remove alveolar bone through gingival sulcus without open-flap approach and suture.This minimally invasive flapless ap-proach can avoid direct exposure of alveolar bone,and has the advantages of less bleeding,less trauma,fast healing,simple operation and high patients'comfort.The review demonstrates surgical methods,indication selection and clinical application results of flapless crown lengthening,aiming at providing reference for clinicians to carry out this novel technique.

BACKGROUND:Ferroptosis-mediated ischemia-reperfusion injury plays a crucial role in the occurrence and progression in pressure ulcers,and there may be pressure ulcer-associated ferroptosis biomarkers,but the mechanism has not been elucidated. OBJECTIVE:To investigate the molecular mechanisms underlying pressure ulcers using bioinformatic analysis,with a focus on identifying differentially expressed genes associated with ferroptosis during the process of pressure ulcer formation,thereby providing novel insights into the clinical treatment of pressure ulcers. METHODS:The single-cell transcriptome sequencing dataset and ferroptosis-related genes were obtained and preprocessed from the Gene Expression Omnibus(GEO)and FerrDb databases.We performed clustering and proportion analyses,metabolic activity and pseudotime analysis,cell communication analysis,ferroptosis gene set cell population identification,and enrichment analysis to determine differentially expressed genes related to ferroptosis.Animal experiments were then conducted for further validation,with 20 Sprague-Dawley rats randomly assigned into a control group and a model group(n=10 per group).The control group received no treatment,while the model group underwent a cycle of ischemia-reperfusion to establish pressure ulcer models.Changes in differentially expressed genes and proteins in the wound tissues of pressure ulcer rats were detected using fluorescent quantitative PCR and western blot,respectively. RESULTS AND CONCLUSION:The single-cell transcriptome sequencing data were clustered into six cell types,with a higher proportion of type 2 and type 3 keratinocytes observed in the pressure ulcer group.There was evident metabolic heterogeneity and evolutionary trajectory among cell populations.Type 2 and type 3 keratinocytes exhibited stronger cell communication,while type 2 keratinocytes demonstrating optimal ligand-receptor interactions.Type 2 keratinocytes demonstrated higher scores for ferroptosis,accompanied by significant upregulation or downregulation of specific genes.A total of 27 Gene Ontology enrichments,20 Kyoto Encyclopedia of Genes and Genomes enrichments,and 24 ferroptosis-related differentially expressed genes,including glutathione peroxidase 4(GPX4)and acyl-CoA synthetase long chain family member 4(ACSL4),were identified.Animal experiments further confirmed the downregulation of GPX4,the ferroptosis-inhibiting protein,and the upregulation of ACSL4,the ferroptosis-promoting protein,in the model group.Overall,these findings indicate the presence of ferroptosis in pressure ulcer tissue.GPX4 and ACSL4 are important genes regulating ferroptosis in pressure ulcer tissues.

Background and purpose:In recent years,domestic radiotherapy equipment and related software have made great progress,and testing the functionality and stability of the equipment and software is an essential step.This paper focused on comparing the differences in intensity-modulated radiation therapy(IMRT)plans dosimetry and organ at risk(OAR)volume calculations for common cancers between uRT-treatment planning system(TPS)and Monaco-TPS,and to evaluate the feasibility of dose calculation for Infinity linac(linear accelerator,Elekta,Sweden)using uRT-TPS.Methods:Twenty cases of rectal cancer,lung cancer,breast cancer and nasopharyngeal carcinoma were selected.The IMRT plans were completed in uRT-TPS and Monaco-TPS.The dose uniformity and conformity,mean dose,maximum dose of planning target volume(PTV)and OAR between two plans under the same prescribed dose of PTV were compared.And the pass rates of two TPS plans validated at the same linear accelerator were compared.Meanwhile,monitor units(MU),source skin distance(SSD)and the volume of OAR in uRT-TPS and Monaco-TPS were compared.Results:Wonderful plans that met the clinical requirements were obtained in uRT-TPS and Monaco-TPS.Comparable uniformity and conformability was received in PTV,and the maximum dose of PTV was reduced by 1.1 Gy for uRT-TPS(P = 0.006).For breast cancer and lung cancer,the dose in lung was lower for Monaco-TPS(P＜0.05).For nasopharyngeal carcinoma,the dose indicators that oral cavity and throat in the uRT-TPS was reduced by 9.2%and 5.1%,respectively.The verification results of absolute point dose(＜3%)and three-dimensional surface dose(＞95%)for both plans met the clinical requirements.The region of interest in uRT-TPS was smaller compared with Monaco-TPS(P＜0.05).Conclusion:A comparable IMRT plan was obtained for common tumors in uRT-TPS and Monaco-TPS.It is feasible to calculate the dose of Infinity linac using uRT-TPS.

Objective:To study the crosstalk between the activating transcription factor 6 (ATF6) and inositol-requiring enzyme 1 (IRE1) - X-box binding protein 1 (XBP1) pathway in oxygen-glucose deprivation/reoxygenation (OGD/R)-injured mouse hippocampal neuronal cell line HT22.Methods:The OGD/R-injured HT22 cell model was used to observe the changes of the indicators of endoplasmic reticulum stress (ERS), cell viability, and apoptosis at different OGD/R time points (0, 3, 6, 12, and 24 hours). HT22 cells in the logarithmic growth phase were randomized into blank control group, control+ATF6 activator (AA147) group, control+IRE1 inhibitor (4μ8c) group, OGD/R model group, OGD/R+AA147 group and OGD/R+4μ8c group (10 μmol/L AA147 or 16 μmol/L 4μ8c was given during the whole process in the AA147 group and 4μ8c group). Western blotting was used to detect the expression of ERS-related proteins [glucose-regulated protein 78 (GRP78), phosphorylated-inositol-requiring enzyme 1 (p-IRE1), and phosphorylated-eukaryotic translation initiation factor-2α (p-eIF2α)], and apoptosis-related proteins (Bcl-2, Bax, caspase-3, and cleaved caspase-3). The mRNA of ERS-related genes, and ATF6 [homocysteine-inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1 (Herpud1), protein disulfide isomerase associated 4 (Pdia4) and Sel-1 suppressor of lin-12-like (Sel1L)] and spliced XBP1 [XBP1s, include DnaJ heat shock protein family member B9 (Erdj4), Sec24 related gene family, member D (Sec24d) and signal sequence receptor, gamma (Ssr3)] induced transcriptional response-related genes were measured by real-time quantitative polymerase chain reaction (RT-qPCR). A cell counting kit-8 (CCK-8) assay was used to detect the viability of HT22 cells. Immunofluorescence was utilized to test the expression of cleaved caspase-3.Results:Compared with the blank control group, the expression of ERS-related proteins p-IRE1 and p-eIF2α were significantly increased at 12 hours and 3 hours following OGD/R, respectively (p-IRE1/β-actin: 2.09±0.10 vs. 1.00±0.00, p-eIF2α/β-actin: 1.39±0.11 vs. 1.00±0.00, both P < 0.01). The mRNA expressions of ERS-related genes [ATF6, XBP1s, unspliced XBP1 (XBP1u), activating transcription factor 4 (ATF4), CCAAT/EBP homologous protein (CHOP)] were also upregulated in different OGD/R timepoint in HT22 cells, which indicated ERS was activated in OGD/R-stimulated HT22 cells. Compared with the OGD/R model group, the expression of protein p-IRE1 was not changed, but the mRNA of XBP1s and XBP1u were obviously downregulated in the OGD/R+AA147 group [XBP1s (2 -ΔΔCt): 0.76 (0.71, 0.92) vs. 1.13 (1.03, 1.29), XBP1u (2 -ΔΔCt): 0.29±0.05 vs. 0.52±0.04, both P < 0.01], whereas the expressions of XBP1s-induced transcriptional response downstream genes did not change significantly. Compared with the OGD/R model group, the protein of short-form ATF6 (sATF6) and GRP78 were not changed after administration of 4μ8c, neither was the mRNA expression of ATF6-induced transcriptional response-related genes. These results showed that the mRNA expression of XBP1s and XBP1u were inhibited by AA147-induced activation of ATF6, but no crosstalk was observed between the transcriptional response induced by ATF6 and XBP1s. Compared with the blank control group, the cell viability decreased significantly at OGD/R 3 hours [(44.64±5.12) % vs. (99.13±5.76) %, P < 0.01], the ratios of apoptosis-related proteins Bax/Bcl-2 and cleaved caspase-3/caspase-3 were significantly increased at OGD/R 3 hours and OGD 0 hour, respectively (Bax/Bcl-2: 6.15±1.65 vs. 1.00±0.00, cleaved caspase-3/caspase-3: 17.48±2.75 vs. 1.00±0.00, both P < 0.01), which indicated that apoptosis was activated in OGD/R-treated HT22 cells. Compared with the OGD/R model group, the cell viability decreased significantly [(36.52±17.78)% vs. (69.90±9.43)%, P < 0.01], and the ratios of Bax/Bcl-2 and cleaved caspase-3/caspase-3 were significantly upregulated in the OGD/R+AA147 group in HT22 cells (Bax/Bcl-2: 2.06±0.31 vs. 1.10±0.25, cleaved caspase-3/caspase-3: 3.35±0.59 vs. 0.55±0.09, both P < 0.01). Conclusion:Under our experimental conditions, no obvious crosstalk between the transcriptional response induced by ATF6 and XBP1s was observed, while ATF6 activation induced by AA147 suppressed mRNA expression of XBP1s and XBP1u and promoted cell death in OGD/R-treated HT22 cells.

Polyetheretherketone (PEEK) as a new type of thermoplastic engineering plastic, has good biological activity, elastic modulus close to human cortical bone and radiation permeability, and has been widely used in medical field. This study aims to explore the safety and clinical efficacy of using 3D printing personalized PEEK materials to repaire scapular bone defects after bone tumor resection. A total of 6 patients who underwent the implantation of 3D printed PEEK scapular prosthesis from January 2020 to December 2021 in Yunnan Cancer Hospital were retrospectively analyzed. There were 3 males and 3 females, with age ranged from 14 to 52 years. There were 1 case of synovial sarcoma, 1 of Ewing's sarcoma, and 4 of chondrosarcoma. PEEK prosthesis was designed and fabricated based on CT data before surgery. Tumor resection and prosthesis replacement were performed under the premise of ensuring safe surgical boundaries, including 2 cases of total scapular prosthesis replacement and 4 cases of partial scapular prosthesis replacement. The operation time was 90-170 min, and the intraoperative blood loss was 100-400 ml. All 6 patients received satisfactory follow-up, with a tumor progression free survival time of 16-28 months. No tumor recurrence or metastasis was observed, and all patients survived tumor free. At last follow-up, the Constant-Murley shoulder joint score was a minimum of 62 points and a maximum of 68 points. The Japanese Orthopaedic Association's shoulder joint score was 63 points minimum and 78 points maximum. Computer-aided design 3D printing PEEK material prosthesis has certain advantages in the treatment of scapular tumor limb salvage. It has light weight, well adapted, relatively simple installation, good histocompatibility, and can obtain a better appearance and function of the shoulder joint after operation. It can become one of the options for limb salvage treatment of scapular tumor.

Objective: To analyze the epidemiological characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive in anal and/or throat swabs after discharge during the domestic imported epidemic stage in Guangdong Province in early 2020. Methods: The COVID-19 confirmed cases with the onset time before March 1, 2020 in Guangdong Province were collected to analyze the demographic data, epidemiological characteristics, and specimen collection and testing data after discharge. Logistic regression model was used for influencing factors analysis of re-positive cases. Results: A total of 1 286 COVID-19 confirmed cases were included, the M(Q₁,Q₃) of age was 44(32,58)years, 617 cases were male, 224 cases were re-positive in anal and/or throat swabs with the re-positive rate 17.42%. The M(Q₁,Q₃) of age of re-positive cases was 35(23, 50) years, which was younger than that of re-negative cases age was those 46(33, 59) years (P<0.001). With the increase of age, re-positive rate decreased (χ²_trend=52.73, P<0.001). 85.27% (191/224) of re-positive cases were found in 14 d after discharge, the duration time of re-positive status was 13(7, 24) d, and 81.69% (183/224) of re-positive cases were re-tested negative in 28 d after re-positive date. No fever and other symptoms had been observed among re-positive cases during the whole follow-up. No secondary infectious cases had been found among close contacts after 14 d of centralized isolation and sampling screening. Univariate logistic regression model analysis revealed that the influencing factors of the re-positive cases included age, occupation, clusters, clinical types, and admission time. Multivariate logistic regression model analysis revealed that age was an independent risk factor. Conclusions: SARS-CoV-2 viral nucleic acid re-positive is found in COVID-19 confirmed cases after discharge in Guangdong Province. Most re-positive cases are confirmed among 14 d after discharge and re-test to negative among 28 d after re-positive date. Age is an risk factor for re-positive cases after discharge.
COVID-19 ; China/epidemiology* ; Epidemics ; Humans ; Male ; Nucleic Acids ; SARS-CoV-2