ObjectiveTo establish a mouse model of hypoxic pulmonary hypertension (HPH) through intermittent hypoxia induction, and to develop a comprehensive and reliable evaluation system for the HPH model, thereby providing experimental evidence for mechanistic studies and translational applications related to this disease. MethodsTwenty-four male specific pathogen-free (SPF) BALB/c mice were randomly divided into a control group and a model group, with 12 mice per group. Mice in the model group were placed in a hypobaric oxygen chamber control system to establish the HPH model, whereas mice in the control group received no intervention. After 28 days of modeling, a comprehensive evaluation of the pathophysiological characteristics of both groups was performed using a general condition scoring scale, echocardiography, hemodynamic measurements, blood gas analysis, hematological tests, organ coefficient determination, histopathological examination, and enzyme-linked immunosorbent assay (ELISA). In addition, correlation analyses were conducted among echocardiographic parameters, the contents of endothelin‑1 (ET‑1) and N‑terminal pro‑B‑type natriuretic peptide (NT‑proBNP) in lung tissue, and other measured indices. ResultsWith prolonged modeling duration time, body weight, water intake, and activity level of mice in the model group were significantly decreased compared with the control group (P<0.05). Echocardiography showed that, compared with the control group, the model group exhibited increased right ventricular dimensions (P<0.01), right ventricular anterior wall thickening (P<0.01), and widened main pulmonary artery diameter (P<0.01), whereas the peak systolic velocity across the pulmonary valve, tricuspid annular plane systolic excursion, and peak systolic velocity of the tricuspid annulus were significantly decreased (P<0.001); tricuspid regurgitation was observed in some model animals. Hemodynamic results revealed that right ventricular systolic pressure was elevated in the model group compared with the control group (P<0.001). Blood gas analysis showed that pH, partial pressure of oxygen, oxygen saturation, actual bicarbonate, and total carbon dioxide were all decreased in the model group compared with the control group (P<0.01). Hematological indices demonstrated that lymphocyte counts (P<0.05) and reticulocyte counts (P<0.001) were decreased in the model group compared with the control group. Compared with the control group, the organ coefficients of heart and lung in the model group were significantly increased (P<0.05 and P<0.001). Pathological examination revealed that the right ventricular hypertrophy index was significantly increased in the model group (P<0.001), with varying degrees of damage to the right ventricle, pulmonary artery, and pulmonary vessels; both the pulmonary artery wall thickness percentage and the pulmonary wall area percentage were significantly elevated (P<0.001). ELISA results showed that the levels of ET‑1 and NT‑proBNP in lung tissues were significantly increased in the model group compared with the control group (P<0.05 and P<0.001, respectively). Correlation analysis indicated that some echocardiographic parameters were highly correlated with multiple indices in the development of HPH (P<0.05). ConclusionEchocardiography can accurately assess a series of hemodynamic changes in HPH, including right ventricular structural, functional impairment, and pulmonary hypertension. Laboratory tests not only help verify whether the model has been successfully established, but also provide deeper insights into the pathogenesis of HPH, evaluate the effects of interventions, and offer scientific evidence for clinical outcomes. Pathological examination can further confirm the alterations in pulmonary vascular remodeling and increased right heart load. This multimodal analysis provides a reliable animal model and evaluation paradigm for both basic and translational research on HPH, and is of great significance for exploring disease mechanisms and developing precision therapeutic strategies.

BACKGROUND:The cryopreservation technology enables tissues/cells to be stored for a long time in a low-temperature environment while maintaining the integrity of their activity and function,which is of great significance for the construction of cell therapy,tissue engineering and biological sample banks.Cryoprotective agents often contain dimethyl sulfoxide and serum.To avoid the toxic side effects of dimethyl sulfoxide,the complexity of serum components and immune responses,although some finished cryoprotective agents have been marketed,they are faced with many difficulties such as high cost and limited application.Therefore,there is an urgent need to develop a cryoprotective agent with clear components and the ability to solve the above problems.OBJECTIVE:To evaluate the effects of a novel cryoprotectant on cryopreservation efficiency of different tissue and cell sources.METHODS:By applying the novel cryoprotectant as an experimental group with the commercially available and widely used cryoprotectant(control group)to umbilical cord Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,NK and CIK cells,comparative analyses were conducted in terms of cell morphology,number,viability,surface markers,differentiation potential,and cell-killing toxicity assay before cryopreservation and after resuscitation thawing.We confirmed the cryopreservation effect of the new cryoprotectant and its potential application value.RESULTS AND CONCLUSION:(1)The novel cryoprotectant facilitated the normal growth of cryopreserved Wharton's jelly tissue upon recovery,exhibiting mesenchymal stem cell morphology.No significant differences were observed between the experimental and control groups in terms of cell recovery rate,surface markers,and differentiation potential.(2)There was no significant difference in the number and viability of cells between the experimental group and the control group after cryopreservation of cord blood/peripheral blood mononuclear cells,and the cryo-resuscitated cell numbers and viability of derived NK cells/CIK cells did not show significant difference between the experimental and control groups.(3)For NK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportion of CD56+CD16+cell subpopulations between the experimental group and the control group.For CIK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportions of CD3+CD8+and CD3+CD56+cell subpopulations between the experimental group and the control group.(4)In terms of cytotoxicity testing,when the effective-target ratio of immune cells and melanoma cell line Mel624 was 20:1,whether it was NK cells/CIK cells derived from cord blood or peripheral blood mononuclear cells,there was no significant difference in the tumoricidal activity of cells between the experimental group and the control group.These findings suggest that the novel cryoprotectant can replace existing commercially available and widely used cryoprotectants,and is applicable to Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,as well as NK and CIK cells,providing a solid technical foundation for the scaling,standardization,and commercialization of universal cryoprotectants.

BACKGROUND:The cryopreservation technology enables tissues/cells to be stored for a long time in a low-temperature environment while maintaining the integrity of their activity and function,which is of great significance for the construction of cell therapy,tissue engineering and biological sample banks.Cryoprotective agents often contain dimethyl sulfoxide and serum.To avoid the toxic side effects of dimethyl sulfoxide,the complexity of serum components and immune responses,although some finished cryoprotective agents have been marketed,they are faced with many difficulties such as high cost and limited application.Therefore,there is an urgent need to develop a cryoprotective agent with clear components and the ability to solve the above problems.OBJECTIVE:To evaluate the effects of a novel cryoprotectant on cryopreservation efficiency of different tissue and cell sources.METHODS:By applying the novel cryoprotectant as an experimental group with the commercially available and widely used cryoprotectant(control group)to umbilical cord Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,NK and CIK cells,comparative analyses were conducted in terms of cell morphology,number,viability,surface markers,differentiation potential,and cell-killing toxicity assay before cryopreservation and after resuscitation thawing.We confirmed the cryopreservation effect of the new cryoprotectant and its potential application value.RESULTS AND CONCLUSION:(1)The novel cryoprotectant facilitated the normal growth of cryopreserved Wharton's jelly tissue upon recovery,exhibiting mesenchymal stem cell morphology.No significant differences were observed between the experimental and control groups in terms of cell recovery rate,surface markers,and differentiation potential.(2)There was no significant difference in the number and viability of cells between the experimental group and the control group after cryopreservation of cord blood/peripheral blood mononuclear cells,and the cryo-resuscitated cell numbers and viability of derived NK cells/CIK cells did not show significant difference between the experimental and control groups.(3)For NK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportion of CD56+CD16+cell subpopulations between the experimental group and the control group.For CIK cells derived and differentiated from cord blood/peripheral blood mononuclear cells,there was no significant difference in the proportions of CD3+CD8+and CD3+CD56+cell subpopulations between the experimental group and the control group.(4)In terms of cytotoxicity testing,when the effective-target ratio of immune cells and melanoma cell line Mel624 was 20:1,whether it was NK cells/CIK cells derived from cord blood or peripheral blood mononuclear cells,there was no significant difference in the tumoricidal activity of cells between the experimental group and the control group.These findings suggest that the novel cryoprotectant can replace existing commercially available and widely used cryoprotectants,and is applicable to Wharton's jelly tissue,umbilical cord mesenchymal stem cells,umbilical cord blood/peripheral blood mononuclear cells,as well as NK and CIK cells,providing a solid technical foundation for the scaling,standardization,and commercialization of universal cryoprotectants.

BACKGROUND:Studies have shown that intradiscal injection of syringin solution can improve the structure and function of the intervertebral disc,prevent and slow down the process of intervertebral disc degeneration in rats.However,the biological half-life of syringin is short and it is difficult for it to continue to play a role in the intervertebral disc.Its bioavailability needs to be further improved.OBJECTIVE:To observe the effect of syringin-chitosan hydrogel on intervertebral disc degeneration in rats and the mechanism of syringin in the treatment of intervertebral disc degeneration.METHODS:(1)Cell experiment:Passages 2-5 rat nucleus pulposus cells were divided into four groups for treatment.The normal control group did not undergo any treatment.The degeneration group was added with interleukin-1β(to establish the intervertebral disc degeneration cell model).The drug group was added with interleukin-1β and syringing.The inhibitor group was added with interleukin-1β,syringing,and phosphatidylinositol 3-kinase(PI3K)inhibitor LY294002.After 24 hours of treatment,apoptosis,extracellular matrix,oxidative stress,and apoptosis-related proteins and PI3K/protein kinase B(AKT)signaling pathway proteins were detected respectively.(2)Animal experiment:Syringin-chitosan hydrogels were prepared,and the micromorphology and slow-release properties of the hydrogels were tested.Thirty SD rats were randomly divided into model control group,model intervention group,hydrogel group,syringin solution group,and syringin hydrogel group,with 6 rats in each group.The intervertebral disc degeneration model was established by the acupuncture method.Immediately after model establishment,the rats in model intervention group,hydrogel group,syringin solution group,and syringin hydrogel group were injected with PBS,chitosan hydrogel,syringin solution,and syringin-chitosan hydrogel,respectively.The samples were taken 8 weeks after modeling for histological detection.RESULTS AND CONCLUSION:(1)Cell experiment:Compared with the normal control group,apoptosis rate,reactive oxygen species level,and expression of BAX,cleaved caspase-9,cleaved caspase-3,and matrix metalloproteinase 13 protein were increased in the nucleus pulpocytes in the degeneration group(P＜0.05),and the expression levels of p-PI3K,p-AKT,BCL-2,and type Ⅱ collagen were decreased(P＜0.05).Superoxide dismutase activity decreased(P＜0.05).Compared with the degeneration group,apoptotic rate,reactive oxygen species level,and expression of BAX,cleaved caspase-9,cleaved caspase-3,and matrix metalloproteinase 13 protein were decreased in the syringin solution and syringin solution groups(P＜0.05),and expression levels of p-PI3K,p-AKT,BCL-2,and type Ⅱ collagen were increased(P＜0.05).Superoxide dismutase activity increased(P＜0.05).LY294002 could partially inhibit the effect of syringin.(2)Animal experiment:Syringin-chitosan hydrogel had a loose porous structure and good slow-release performance.Hematoxylin-eosin and safranin O-fast green staining showed that compared with the model control group and model intervention group,chitosan hydrogel,syringin solution and syringing-chitosan hydrogel could improve the intervertebral disc degeneration in different degrees,and the therapeutic effect of syringing-chitosan hydrogel was better than that of hydrogel and drug solution alone.(3)These findings indicate that syringin can regulate apoptosis of nucleus pulposus cells and extracellular matrix degradation induced by oxidative stress by activating PI3K/AKT signaling pathway,thus delaying disc degeneration.Compared with syringin injection alone,syringin loading in chitosan hydrogel can further delay the progression of intervertebral disc degeneration in rats.

Objective To investigate the changes of inflammatory factors in bronchoalveolar lavage fluid(BALF),lung tissue,and serum of a rat pneumonia model induced by inhalation of lipopolysaccharides(LPS).Methods Three days after modeling by LPS 4 mg/mL inhalation,15 min/d,was conducted while monitoring the particle size distribution and aerosol concentration of LPS,the degree of inflammation in lung tissues of rats in each group was observed via HE staining,and neutrophils in BALF were counted by microscope.The contents of interferon gamma(IFN-γ),interleukin-1 beta(IL-1 β),IL-4,IL-5,IL-6,IL-10,IL-13,tumor necrosis factor alpha(TNF-α),and KC/GRO in lung tissue,serum,and BALF were detected by Meso Scale Discovery.Results The lung histopathology of model rats displayed focal and diffuse alveolar epithelial necrosis with shedding and the aggregation and infiltration of inflammatory cells.The particle size distribution of atomized LPS was as follows,Dv(10)=0.6974μm,Dv(50)=3.387 μm,Dv(90)=8.836 μm.The aerosol concentration of LPS was 4.08 g/m3,and the calculated inhalation dose for rats was 47.10 mg/kg.The neutrophil count(P＜0.01)and contents of IL-1β,IL-6,and TNF-α(P＜0.05,P＜0.001,P＜0.001)in the BALF,and the contents of IL-1β,IL-6,and KC/GRO in lung tissue(P＜0.01,P＜0.05,P＜0.01),of model rats were significantly increased.No biologically significant changes were observed in inflammatory factor levels in the serum.Conclusions In the acute pneumonia model induced by inhalation of LPS,significant changes in inflammatory factors such as IL-1β,IL-6,KC/GRO,and TNF-α were observed in both lung tissue and bronchoalveolar lavage fluid(BALF),while no notable changes in these inflammatory factors were detected in serum.This indicates that the inflammation responses are primarily localized in the lungs.

Objective To investigate the changes of inflammatory factors in bronchoalveolar lavage fluid(BALF),lung tissue,and serum of a rat pneumonia model induced by inhalation of lipopolysaccharides(LPS).Methods Three days after modeling by LPS 4 mg/mL inhalation,15 min/d,was conducted while monitoring the particle size distribution and aerosol concentration of LPS,the degree of inflammation in lung tissues of rats in each group was observed via HE staining,and neutrophils in BALF were counted by microscope.The contents of interferon gamma(IFN-γ),interleukin-1 beta(IL-1 β),IL-4,IL-5,IL-6,IL-10,IL-13,tumor necrosis factor alpha(TNF-α),and KC/GRO in lung tissue,serum,and BALF were detected by Meso Scale Discovery.Results The lung histopathology of model rats displayed focal and diffuse alveolar epithelial necrosis with shedding and the aggregation and infiltration of inflammatory cells.The particle size distribution of atomized LPS was as follows,Dv(10)=0.6974μm,Dv(50)=3.387 μm,Dv(90)=8.836 μm.The aerosol concentration of LPS was 4.08 g/m3,and the calculated inhalation dose for rats was 47.10 mg/kg.The neutrophil count(P＜0.01)and contents of IL-1β,IL-6,and TNF-α(P＜0.05,P＜0.001,P＜0.001)in the BALF,and the contents of IL-1β,IL-6,and KC/GRO in lung tissue(P＜0.01,P＜0.05,P＜0.01),of model rats were significantly increased.No biologically significant changes were observed in inflammatory factor levels in the serum.Conclusions In the acute pneumonia model induced by inhalation of LPS,significant changes in inflammatory factors such as IL-1β,IL-6,KC/GRO,and TNF-α were observed in both lung tissue and bronchoalveolar lavage fluid(BALF),while no notable changes in these inflammatory factors were detected in serum.This indicates that the inflammation responses are primarily localized in the lungs.

Enteric human adenovirus(HAdV),a common cause of acute viral gastroenteritis in children,frequently triggers spo-radic infections,nosocomial transmissions,and outbreaks in kindergarten settings.This study was aimed at investigating the molecular characteristics and genetic evolution of enteric HAdV among patients with acute gastroenteritis younger than 5 years in China,to pro-vide foundational data for disease prevention and control.A total of 8 074 stool samples were collected from hospitalized or outpatient children younger than 5 years with acute gastroenteritis in China during 2023.HAdV screening was conducted with real-time fluores-cence PCR.Positive samples were sequenced,then subjected to bioinformatics analysis including genotyping,homology assessment,and phylogenetic analysis with GenBank,BioAider,and MEGA11.0.A total of 370 samples(4.58%)tested positive for HAdV.Two enteric HAdV genotypes were identified:HAdV-F41(which predominated,at 98.09%)and HAdV-F40(1.90%).HAdV-F41 was the dominant genotype among patients with acute gastroenteritis younger than 5 years in China.Bioinformatics analysis indicated that the predominant HAdV lineages in China were lineage 1 and 2,whereas European lineage 3 showed no influence.Systematic and long-term surveillance of HAdV should help elucidate its diversity and evolutionary patterns in China,thereby providing scientific evi-dence for developing more effective prevention strategies.

This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.

Enteric human adenovirus(HAdV),a common cause of acute viral gastroenteritis in children,frequently triggers spo-radic infections,nosocomial transmissions,and outbreaks in kindergarten settings.This study was aimed at investigating the molecular characteristics and genetic evolution of enteric HAdV among patients with acute gastroenteritis younger than 5 years in China,to pro-vide foundational data for disease prevention and control.A total of 8 074 stool samples were collected from hospitalized or outpatient children younger than 5 years with acute gastroenteritis in China during 2023.HAdV screening was conducted with real-time fluores-cence PCR.Positive samples were sequenced,then subjected to bioinformatics analysis including genotyping,homology assessment,and phylogenetic analysis with GenBank,BioAider,and MEGA11.0.A total of 370 samples(4.58%)tested positive for HAdV.Two enteric HAdV genotypes were identified:HAdV-F41(which predominated,at 98.09%)and HAdV-F40(1.90%).HAdV-F41 was the dominant genotype among patients with acute gastroenteritis younger than 5 years in China.Bioinformatics analysis indicated that the predominant HAdV lineages in China were lineage 1 and 2,whereas European lineage 3 showed no influence.Systematic and long-term surveillance of HAdV should help elucidate its diversity and evolutionary patterns in China,thereby providing scientific evi-dence for developing more effective prevention strategies.

This study investigated the full-genome molecular characteristics of a rotavirus vaccine-derived strain,G1P[8]geno-type A group rotavirus RVA/Human-wt/CHN/HN1140/2021/G1P[8](referred to as HN1140).The gene fragments of the HN1140 strain were amplified with reverse transcription-polymerase chain reaction(RT-PCR)combined with whole-genome primers to obtain the full genome sequence.Genotyping was performed with the online genotyping tool RotaC 2.0,and similarity and genetic evolution analyses for each gene segment were conducted in DNAstar5.1 and MEGA11.0 software.The genotype of the HN1140 strain was deter-mined to be G1-P[8]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis demonstrated that all 11 genomic segments clus-tered closely with the RotaTeq vaccine strains,sharing 99.7%-100%nucleotide sequence similarity.Notably,VP1,VP2,VP6,and NSP2-NSP5 segments showed 100%nucleotide identity with RotaTeq strains.Comparative genomic analysis identified 13 nucleotide and 8 amino acid substitutions between HN1140 and RotaTeq strains,localized within the VP7,VP4,VP1,VP2,VP3,and NSP1 segments.The HN1140 strain exhibited the genotype G1-P[8]-A3-T6-H3,which was consistent with the typical profile of a vaccine-derived reassortant.This strain demonstrated high genetic similarity to RotaTeq vaccine strains,with nucleotide sequence identity ranging from 99.7%to 100%.These findings suggested that HN1140 evolved from RotaTeq vaccine strains through genetic reassortment.