ObjectiveA mouse model of vaccinia virus Tiantan strain (VTT)-induced encephalopathy was developed using AG6 mice. MethodsVTT was amplified by infecting Vero cells at a multiplicity of infection (MOI) of 0.01, followed by concentration and titration. After 72 h of incubation, virus-containing cells were collected and subjected to concentration. The concentrated viral suspension was serially diluted (10-fold dilutions) and added to 6-well plates containing confluent Vero cell monolayers for plaque assay. The number of plaques formed in each well was counted, and the virus titer was calculated based on the dilution factor. Fourteen 5-6-week-old AG6 mice (half male and half female, housed separately by sex) were randomly divided into a control group (n=3, PBS), a low-dose group (n=6, 1×10⁵ PFU), and a high-dose group (n=5, 5×10⁵ PFU). The mice were anesthetized by isoflurane inhalation and then infected via intranasal instillation. The mental state of the mice in each group was observed daily, and the body weight and mortality were recorded. On day 13 post-infection, 2% Evans Blue (4 mL/kg body weight) was administered via tail vein injection to assess blood-brain barrier (BBB) disruption. Subsequently, brain tissue samples were collected for immunofluorescence analysis to evaluate the activation of astrocytes and microglia. ResultsThe titer of purified VTT was 1×10⁷ PFU/mL. Compared with the control group, mice in the low-dose group showed no significant change in body weight, and no lethality was observed. In contrast, mice in the high-dose group exhibited significant weight loss starting on day 5 post-infection (P<0.05), accompanied by lethality. On day 13 post-infection, no Evans Blue extravasation was detected in the brain tissues of the low-dose group, while the olfactory bulb region of the high-dose group displayed distinct blue staining, indicating disruption of the BBB. Immunofluorescence analysis revealed no significant proliferation of astrocytes and microglia in the olfactory bulb region of the low-dose group on day 13 post-infection. In contrast, marked activation of glial cells was observable in the high-dose group. ConclusionAn animal model of VTT-induced encephalopathy in AG6 mice is successfully established, characterized by BBB disruption and reactive gliosis specifically localized to the olfactory bulb region, manifested as astrocytic and microglial proliferation.

Objective To compare functional differences of CD8+T cells in lung tissues between young and aged C57BL/6J mice during the contraction phase and memory immune response phase after infection with influenza A(H1N1)virus.Methods Lung tissues from young(3-month-old)and aged(24-month-old)C57BL/6J female mice without influenza virus infection were collected to prepare single-cell suspensions,which were stimulated with phorbol 12-myristate 13-acetate(PMA)/ionomycin or cluster of differentiation(CD)3/CD28 antibodies(T-cell antigen receptor/co-stimulatory signals)respectively(non-specific antigens stimulation).Flow cytometry intracellular cytokine staining(ICS)was performed on lung CD8+T cells to detect their secretion capacity of tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ).Young and aged C57BL/6J mice were infected intranasally with 490 PFU PR8 influenza virus,and reinfected with homologous influenza virus 28 days later.Lung tissues were isolated on day 28(the contraction phase)and day 32(the memory immune response phase)after primary infection.Influenza virus-specific MHC-Ⅰ tetramer staining was used to detect the proportion of virus-specific CD8+T cells in lung tissue CD8+T cells,and ICS was used to analyze TNF-α,IFN-γ,and granzyme B expression in CD8+CD44high T cell subset.Results After non-specific antigen stimulation,TNF-α and IFN-γ secretion capacity in lung tissue CD8+T cells of aged group mice was significantly higher than that of young group(P＜0.05).After virus-specific antigen stimulation,there were no statistically significant differences in the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B between the two groups of mice during the contraction phase(P＞0.05),while during the memory immune response phase,the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B in the aged group mice were significantly lower than those in the young group(P＜0.05).Conclusion CD8+T cells in aged mice maintain normal immune-related factor expression function under non-specific antigen stimulation,but show impaired immune-related factor expression function during antigen-specific memory immune response phase,suggesting that aging leads to defects in the formation or maintenance of CD8+T cell immune memory.

Aim To evaluate the bioequivalence of two oral preparations of rivaroxaban tablets(test preparation T and refe-rence preparation R)in fasting/postprandibular state in healthy Chinese subjects.Methods A randomized,open,single-dose,four-cycle,completely repeated crossover experiment was used in this study.A total of 70 healthy male and female subjects were enrolled,including 38 subjects in the fasting group and 32 sub-jects in the postprandial group.Rivaroxaban tablets(2.5 mg/tablet)were taken orally once per cycle and their reference preparations were tested.The plasma rivaroxaban concentration was determined by LC-MS/MS method.The pharmacokinetic parameters of rivaroxaban tablets were calculated by WinNonlin software,and the parameters were analyzed and processed.Re-sults The PK parameters of rivaroxaban tablets and reference preparations in fasting group were as follows:Cmax was(72.48±17.08)and(66.36±15.64)μg·L-1,respectively.AUC0-t were(383.49±101.06)and(370.43±102.16)h·ng·mL-1,and AUC0-inr were(389.58±102.28)and(375.84±103.01)h·μg·L-,respectively.Main PK parameters of subjects taking rivaroxaban tablets orally after meals:Cmax were(66.48±15.64 and 60.87±13.44)μg·L-1,AUC0-t were(404.44±72.58)and(381.80±79.93)h·μg·L-1,re-spectively.AUC0_inf was(410.88±73.55)and(393.64±69.71)h·μg·L-1,respectively.Under fasting and postmeal conditions,subjects took rivaroxaban test and reference prepara-tion orally,one tablet(2.5 mg/tablet)each time.The geometric mean of the main pharmacokinetic parameters of rivaroxaban in plasma(Cmax,AUC0-t,AUC0-inf)and their corresponding values had a 90％confidence interval ranging from 80.00％to 125.00％.No serious adverse events or unexpected adverse e-vents occurred in both groups.Conclusion Rivaroxaban tablets are bioequivalent and safe in vivo under fasting and postprandial conditions.

Objective To construct mouse models of vaccinia virus infection using C57BL/6N and BALB/C mice infected with vaccinia virus VR-1354(WR(NIH TC-adapted)),and to compare the differences between the models in the two mouse strains.Methods Vaccinia virus VR-1354 was amplified,concentrated,and titrated,according to conventional method.The median lethal doses(LD50)of vaccinia virus V R-1354 for C57BL/6N and BALB/C mice were determined,respectively,and mice from the two strains were infected with the respective LD50.Lung tissues from control and experimental mice were removed for hematoxylin and eosin staining on days 3,7,and 14,and changes in the virus load in the lung tissues were measured at the same times.Results The titer of the amplified vaccinia virus VR-1354 was 3×108 plaque forming units(PFU)/mL.The LD50 values in C57BL/6N and BALB/C mice were 2.5×103and BALB/C 2.8×103PFU,respectively.After infecting mice from both strains with 2.5× 103 PFU of vaccinia virus VR 1354,lung tissue lesions worsened with increasing infection time,but the symptoms of the mice tended to recover after day 7.The virus loads in lung tissues began to increase on day 3 in both strains,peaked on day 7,and then gradually decreased.Conclusions C57BL/6N and BALB/C mouse models infected with vaccinia virus VR-1354 were established successfully.The virus can cause obvious lesions in mouse lung tissues,including inflammatory cell infiltration and alveolar cavity fluid exudation.The degree of disease onset and susceptibility differed between the two mouse strains,with C57BL/6N mice showing higher susceptibility to this virus than BALB/C mice.

Objective To compare functional differences of CD8+T cells in lung tissues between young and aged C57BL/6J mice during the contraction phase and memory immune response phase after infection with influenza A(H1N1)virus.Methods Lung tissues from young(3-month-old)and aged(24-month-old)C57BL/6J female mice without influenza virus infection were collected to prepare single-cell suspensions,which were stimulated with phorbol 12-myristate 13-acetate(PMA)/ionomycin or cluster of differentiation(CD)3/CD28 antibodies(T-cell antigen receptor/co-stimulatory signals)respectively(non-specific antigens stimulation).Flow cytometry intracellular cytokine staining(ICS)was performed on lung CD8+T cells to detect their secretion capacity of tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ).Young and aged C57BL/6J mice were infected intranasally with 490 PFU PR8 influenza virus,and reinfected with homologous influenza virus 28 days later.Lung tissues were isolated on day 28(the contraction phase)and day 32(the memory immune response phase)after primary infection.Influenza virus-specific MHC-Ⅰ tetramer staining was used to detect the proportion of virus-specific CD8+T cells in lung tissue CD8+T cells,and ICS was used to analyze TNF-α,IFN-γ,and granzyme B expression in CD8+CD44high T cell subset.Results After non-specific antigen stimulation,TNF-α and IFN-γ secretion capacity in lung tissue CD8+T cells of aged group mice was significantly higher than that of young group(P＜0.05).After virus-specific antigen stimulation,there were no statistically significant differences in the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B between the two groups of mice during the contraction phase(P＞0.05),while during the memory immune response phase,the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B in the aged group mice were significantly lower than those in the young group(P＜0.05).Conclusion CD8+T cells in aged mice maintain normal immune-related factor expression function under non-specific antigen stimulation,but show impaired immune-related factor expression function during antigen-specific memory immune response phase,suggesting that aging leads to defects in the formation or maintenance of CD8+T cell immune memory.

Objective:To compare the dose-response effects of single-fraction ultra-high dose rate (FLASH) and conventional dose rate (CONV) whole abdominal irradiation (WAI) with X-rays on acute radiation-induced intestinal injury in mice, in order to identify optimal dose parameters and potential mechanisms.Methods:A total of 186 male C57BL/6J mice were randomly assigned to a non-irradiation group ( n=6), FLASH irradiation groups ( n=90), and CONV irradiation groups ( n=90). Acute radiation-induced intestinal injury models were established using single-fraction WAI with 11, 12, 13, 14, and 15 Gy X-rays (200 Gy/s for FLASH and 4 Gy/min for CONV). Changes in body weight, stool characteristics, and disease activity index (DAI) scores were assessed at 9 d post-irradiation. At 7 d post-irradiation at 11, 12, and 13 Gy, the intestines were collected for macroscopic examination and length measurement. The small intestine was selected for HE staining and quantitative analysis of intestinal crypt number and mucosal epithelial thickness. The survival of mice was assessed at 15 d post-WAI across all dose groups. Results:After single-fraction WAI at 11, 12, and 13 Gy, the body weight was higher in the FLASH group than that in the CONV group ( t=10.17, 12.65, 10.16, P<0.05). The DAI scores for the FLASH group were 1.00±1.10, 3.17±0.75, and 2.83±1.17, respectively, which were lower than those of the CONV group (4.33±0.52, 7.00±0.00, 8.60±0.55; t=8.70, 11.71, 14.99, P<0.05). However, after WAI at 14 Gy and 15 Gy, there were no significant differences in body weight and DAI between the FLASH group and the CONV group ( P>0.05). At 7 d after single-fraction WAI at 11, 12, and 13 Gy, mice in the FLASH group exhibited less intestinal congestion, edema, and shortening compared with the CONV group. The difference between the FLASH and CONV groups were statistically significant in small intestine length at 11 and 13 Gy ( t=4.42, 3.78, P<0.05), and in colorectal length at 11 and 12 Gy ( t=3.97, 3.12, P<0.05). Small intestine HE staining revealed superior preservation of intestinal architecture in the FLASH group compared with the CONV group, characterized by longer villi, increased crypt numbers, thicker mucosal epithelium, and enhanced structural integrity. The differences in crypt number and mucosal epithelial thickness were statistically significant ( tcrypt=13.10, 23.80, 11.90; tmucosal=5.75, 2.64, 7.74; P<0.05). At 15 d post-irradiation, the survival rate in the 15 Gy FLASH group was higher than that in the CONV group (50% vs. 10%, χ2=5.39, P<0.05), with a median survival extension of 6 d ( HR=0.340, 95% CI: 0.115 4-0.999 9). No significant survival differences were observed between the FLASH group and the CONV group at 11, 12, 13, and 14 Gy ( P>0.05). Conclusions:FLASH irradiation significantly alleviated acute radiation-induced intestinal injury from medium single-fraction WAI with 11, 12, and 13 Gy X-rays compared with CONV irradiation, and showed potential to improve mouse survival after single-fraction WAI at 15 Gy. This effect is likely associated with the preservation of intestinal crypts and exhibits a dose-dependent relationship.

Aim To evaluate the bioequivalence of two oral preparations of rivaroxaban tablets(test preparation T and refe-rence preparation R)in fasting/postprandibular state in healthy Chinese subjects.Methods A randomized,open,single-dose,four-cycle,completely repeated crossover experiment was used in this study.A total of 70 healthy male and female subjects were enrolled,including 38 subjects in the fasting group and 32 sub-jects in the postprandial group.Rivaroxaban tablets(2.5 mg/tablet)were taken orally once per cycle and their reference preparations were tested.The plasma rivaroxaban concentration was determined by LC-MS/MS method.The pharmacokinetic parameters of rivaroxaban tablets were calculated by WinNonlin software,and the parameters were analyzed and processed.Re-sults The PK parameters of rivaroxaban tablets and reference preparations in fasting group were as follows:Cmax was(72.48±17.08)and(66.36±15.64)μg·L-1,respectively.AUC0-t were(383.49±101.06)and(370.43±102.16)h·ng·mL-1,and AUC0-inr were(389.58±102.28)and(375.84±103.01)h·μg·L-,respectively.Main PK parameters of subjects taking rivaroxaban tablets orally after meals:Cmax were(66.48±15.64 and 60.87±13.44)μg·L-1,AUC0-t were(404.44±72.58)and(381.80±79.93)h·μg·L-1,re-spectively.AUC0_inf was(410.88±73.55)and(393.64±69.71)h·μg·L-1,respectively.Under fasting and postmeal conditions,subjects took rivaroxaban test and reference prepara-tion orally,one tablet(2.5 mg/tablet)each time.The geometric mean of the main pharmacokinetic parameters of rivaroxaban in plasma(Cmax,AUC0-t,AUC0-inf)and their corresponding values had a 90％confidence interval ranging from 80.00％to 125.00％.No serious adverse events or unexpected adverse e-vents occurred in both groups.Conclusion Rivaroxaban tablets are bioequivalent and safe in vivo under fasting and postprandial conditions.

Objective To construct mouse models of vaccinia virus infection using C57BL/6N and BALB/C mice infected with vaccinia virus VR-1354(WR(NIH TC-adapted)),and to compare the differences between the models in the two mouse strains.Methods Vaccinia virus VR-1354 was amplified,concentrated,and titrated,according to conventional method.The median lethal doses(LD50)of vaccinia virus V R-1354 for C57BL/6N and BALB/C mice were determined,respectively,and mice from the two strains were infected with the respective LD50.Lung tissues from control and experimental mice were removed for hematoxylin and eosin staining on days 3,7,and 14,and changes in the virus load in the lung tissues were measured at the same times.Results The titer of the amplified vaccinia virus VR-1354 was 3×108 plaque forming units(PFU)/mL.The LD50 values in C57BL/6N and BALB/C mice were 2.5×103and BALB/C 2.8×103PFU,respectively.After infecting mice from both strains with 2.5× 103 PFU of vaccinia virus VR 1354,lung tissue lesions worsened with increasing infection time,but the symptoms of the mice tended to recover after day 7.The virus loads in lung tissues began to increase on day 3 in both strains,peaked on day 7,and then gradually decreased.Conclusions C57BL/6N and BALB/C mouse models infected with vaccinia virus VR-1354 were established successfully.The virus can cause obvious lesions in mouse lung tissues,including inflammatory cell infiltration and alveolar cavity fluid exudation.The degree of disease onset and susceptibility differed between the two mouse strains,with C57BL/6N mice showing higher susceptibility to this virus than BALB/C mice.

Objective:To develop the Amputation Scale for Severe Open Pelvic Fractures and explore its application value in patients with severe open pelvic fractures.Methods:A total of 27 patients with severe open pelvic fractures who underwent surgical treatment in Shandong Provincial Hospital Affiliated to Shandong First Medical University from January 2010 to January 2023 were retrospectively analyzed. There were 15 males and 12 females, aged 38.6±11.6 years (range, 13-65 years). There were 13 cases of traffic injuries, 10 cases of fall from height injuries, and 4 cases of mechanical crushing injuries; 20 cases were admitted to the hospital in emergency, and 7 cases were transferred from other hospitals. All fracture types were Tile C, including 14 cases of Tile C1, 8 cases of Tile C2, and 5 cases of Tile C3. There were 16 cases of genitourinary system injury, 8 cases of anal or rectal injury, 12 cases of abdominal injury, 9 cases of chest injury, and 6 cases of craniocerebral trauma. The mangled extremity severity score (MESS) and the Amputation Scale for Severe Open Pelvic Fractures were used to evaluate whether amputation was performed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the two evaluation methods were calculated.Results:Among the 27 patients, 21 cases were treated with pelvic external fixator to control the volume, 16 cases were treated with gauze packing to stop bleeding, 8 cases were treated with temporary abdominal aorta occlusion, and 12 cases were treated with laparotomy because of abdominal injury. Seven of the 27 patients died, with a mortality rate of 26%. In 12 cases of one-stage amputation, 3 cases died, including 1 case died of multiple organ failure syndrome, 1 case died of gastrointestinal bleeding on the 7th day after amputation, and 1 case died of severe infection on the 4th day after amputation. Among the 15 cases of one-stage limb salvage, 4 cases died, of which 2 cases of second-stage amputation died of infection on the 5th day after one-stage limb salvage, and 1 case of one-stage limb salvage died of limb necrosis on the 3rd day after one-stage limb salvage. Two patients died of multiple organ failure syndrome. The MESS score of 27 patients was 6(6, 8) points (range, 6-13 points), and the Amputation Scale for Severe Open Pelvic Fractures score was 9.6±1.8 points (range, 6-14 points). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MESS were 66.7%, 50%, 40%, 75% and 56%, respectively, while those of Amputation Scale for Severe Open Pelvic Fractures were 80%, 89%, 73%, 88% and 82%, respectively. The specificity and accuracy of MESS were significantly lower than those of Amputation Scale for Severe Open Pelvic Fractures ( P<0.05). All 20 patients who survived were followed up for 23.6±7.5 months (range, 11-37 months). Five cases had soft tissue infection at the stump of amputation, which were treated with debridement, and 3 cases underwent skin grafting, and the stump healed well at the last follow-up. Conclusion:The Amputation Scale for Severe Open Pelvic Fractures is better than MESS in the assessment of early amputation in patients with severe pelvic fractures.

Diabetic retinopathy(DR)has emerged as the leading cause of vision loss among working-age people in many countries under the increasing prevalence of diabetes and the longevity of the population. The pathogenesis of DR is complicated and has not been fully elucidated at present, while the treatment methods of DR have not been greatly improved, mainly retinal laser photocoagulation, anti-vascular endothelial growth factor(VEGF)treatment and vitrectomy surgery. The current treatment methods not only have shortcomings, but also bring serious economic burden to patients. Therefore, new methods are needed to explore the pathogenesis of DR, discover new treatments or improve current treatments, and improve the satisfaction of DR patients. In recent years, the identification and quantification of proteins expressed in blood, retina, vitreous humor, aqueous humor, and tears of all observable DR patients and DR rats and differentially expressed proteins after drug intervention have provided new ideas for further exploring the pathogenesis, diagnosis and treatment of DR with the rise of proteomics, which put forward new insights into early detection and treatment.The proteomics of DR in recent years are reviewed, in order to provide new ideas for the diagnosis and treatment of DR.