Antimicrobial resistance (AMR) is a growing public health crisis that requires innovative solutions. Emerging multidrug resistant (MDR) Salmonella typhimurium has raised concern for its effect on pathogenic infection and mortality in humans caused by enteric diseases. To combat these MDR Salmonella typhimurium pathogens, highly effective and broad-spectrum antibiotics such as flufenicol (FFC) need to be evaluated for their potent antibacterial activity against Salmonella typhimurium. However, the low solubility and low oral bioavailability of flufenicol need to be addressed to better combat AMR. In this work, we develop a novel nano-formulation, flufenicol nano-micelles (FTPPM), which are based on d-α-tocopherol polyethylene glycol 1,000 succinate (TPGS)/poloxamer 188 (P188), for the targeted treatment of biofilms formed by drug-resistant Salmonella typhimurium in the intestine. Herein, FTPPM were prepared via a thin film hydration method. The preparation process for the mixed micelles is simple and convenient compared with other existing nanodrug delivery systems, which can further decrease production costs. The optimized FTPPM demonstrated outstanding stability and sustained release. An evaluation of the in vivo anti-drug-resistant Salmonella typhimurium efficacy demonstrated that FTPPM showed a stronger efficacy (68.17 %) than did florfenicol-loaded TPGS polymer micelles (FTPM), flufenicol active pharmaceutical ingredients (FFC-API), and flufenicol commercially available medicine (FFC-CAM), and also exhibited outstanding biocompatibility. Notably, FTPPM also inhibited drug-resistant Salmonella typhimurium from forming biofilms. More importantly, FTPPM effectively restored intestinal flora disorders induced by drug-resistant Salmonella typhimurium in mice. In summary, FTPPM significantly improved the solubility and oral bioavailability of florfenicol, enhancing its efficacy against drug-resistant Salmonella typhimurium both in vitro and in vivo. FTPPM represent a promising drug-resistant Salmonella typhimurium treatment for curbing bacterial resistance via oral administration.

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

Objective:To investigate the clinicopathological and molecular genetic features of high-grade astrocytomas with piloid features (HGAP).Methods:Clinical, histopathological and imaging data of 7 cases of HGAP diagnosed at the Neuropathology Center of Beijing Tiantan Hospital, Beijing, China from August 2023 to October 2024 were collected. The histopathological and molecular features for each case were analyzed.Results:Among the seven patients there were 4 males and 3 females, with the median age of 37 (34, 51) years. Patients exhibited various clinical symptoms and signs depending on the tumor′s location. Four tumors were located in the cerebellum, 2 in the supratentorial region, and 1 in the spinal cord. Magnetic resonance imaging showed that 6 of the 7 patients had cystic and solid lesions, with focal or nodular enhancement and relatively unclear boundaries. Histopathological features had a diverse morphological spectrum and extensive grading. Five cases displayed a pilocytic astrocytoma-like appearance with infiltrative growth patterns, while two cases presented glioblastoma-like morphology, containing locally anaplastic pleomorphic xanthoastrocytoma with minor pilocytic components. All tumors were diffusely positive for GFAP and Olig2, while 4 tumors exhibited partial or complete loss of ATRX. The Ki-67 proliferation index ranged from 2% to 40%. Next-generation sequencing showed that tumor cells most commonly harbored MAPK pathway gene mutations, and/or homozygous deletions of CDKN2A/B, and/or ATRX mutations. Among the 7 HGAP models, 3 cases showed the three types of molecular genetic variations, 1 case showed MAPK mutations and homozygous deletions of CDKN2A/B, 1 case had MAPK mutations and ATRX mutations, 1 case had only MAPK mutations, and 1 case showed no detectable molecular changes. DNA methylation clustering analyses showed that the median model prediction score was 0.94 (range, 0.85-0.99) for the 7 HGAP models. Five cases showed the MGMT promoter hypermethylation. Four patients received radiotherapy and concomitant temozolomide treatment after surgery, while three patients received no known treatments. At the last follow-up, seven patients were alive without any tumor, two patients had recurrence, and one patient was alive with the tumor.Conclusions:HGAP is relatively rare and predominantly occurs in adults. It has a wide histopathological spectrum and various histological grades, characterized by piloid astrocytoma-like and glioblastoma-like histological features. Its diagnosis relies on methylation clustering analysis. Most tumors harbor gene alterations in the MAPK signaling pathway, along with homozygous deletions of CDKN2A/B or ATRX mutations. The biological behavior is typically aggressive, while imaging and histological findings can be misleading. Therefore, clinicians need to increase their diagnostic awareness of this tumor and prevent missed diagnoses.

Objective:To propose a deep learning（DL）-based ultrasound imaging auxiliary tool for automatic segmentation and recognition of the brachial plexus（BP），and to enhance the accuracy and safety of clinical procedures.Methods:It was a multicenter study that collected 773 healthy subjects from Peking University Third Hospital and its branch campuses，the Third Medical Center of the Chinese PLA General Hospital，and Shanghai Eighth People's Hospital between August 2024 and February 2025. Brachial plexus（BP）images in the interscalene groove were captured used high-frequency ultrasound by senior sonographers，a dataset comprising 1 289 standardized images were constructed and the improved model（CHA-TransUNet）was trained. The test set was input into 6 different models（CHA-TransUNet，R50-Unet，TransUnet，SegFormer，SwinUnet，MISSFormer）for segmentation. Segmentation accuracy was evaluated using metrics including the Dice similarity coefficient（DSC），95% Hausdorff distance（HD95）and mean intersection over union（mIoU），and was compared with the segmentation results of 3 ultrasound physicians with varying experience levels（junior physicians and senior physicians）to validate the model's segmentation efficacy.Results:The CHA-TransUNet model established based on a dataset of 1 289 standardized images achieved segmentation results for the BP with a DSC of 90.15%，mIoU of 91.02%，and HD95 of 8.08. Its accuracy was higher than other mainstream models（DSC：90.15% vs. 87.60%，87.77%，81.35%，84.78%，84.55%），significantly better than junior physicians（DSC：90.15% vs. 68.73%， Z=-127.76， P<0.001），and approached the level of senior physician（DSC：90.15% vs. 86.15%， Z=-31.33， P=0.549）. The model demonstrated superior boundary recognition in complex anatomical structures（e.g.，C6/C7 nerve roots）compared to ultrasound physicians（junior and senior）（HD95：8.08 vs. 26.34，17.44，56.80）. Conclusions:This study proposes an analysis model for BP ultrasound images，CHA-TransUNet. This model achieves segmentation and recognition of the BP with relatively complex pathways and structures. The model exhibits high accuracy and stability，outperforming current mainstream network models and junior physicians while approaching the performance level of senior physicians. It assists junior physicians or trainees in more accurately identifying and localizing the BP.

Antimicrobial resistance(AMR)is a growing public health crisis that requires innovative solutions.Emerging multidrug resistant(MDR)Salmonella typhimurium has raised concern for its effect on path-ogenic infection and mortality in humans caused by enteric diseases.To combat these MDR Salmonella typhimurium pathogens,highly effective and broad-spectrum antibiotics such as flufenicol(FFC)need to be evaluated for their potent antibacterial activity against Salmonella typhimurium.However,the low solubility and low oral bioavailability of flufenicol need to be addressed to better combat AMR.In this work,we develop a novel nano-formulation,flufenicol nano-micelles(FTPPM),which are based on D-α-tocopherol polyethylene glycol 1,000 succinate(TPGS)/poloxamer 188(P188),for the targeted treatment of biofilms formed by drug-resistant Salmonella typhimurium in the intestine.Herein,FTPPM were prepared via a thin film hydration method.The preparation process for the mixed micelles is simple and convenient compared with other existing nanodrug delivery systems,which can further decrease pro-duction costs.The optimized FTPPM demonstrated outstanding stability and sustained release.An evaluation of the in vivo anti-drug-resistant Salmonella typhimurium efficacy demonstrated that FTPPM showed a stronger efficacy(68.17％)than did florfenicol-loaded TPGS polymer micelles(FTPM),flufenicol active pharmaceutical ingredients(FFC-API),and flufenicol commercially available medicine(FFC-CAM),and also exhibited outstanding biocompatibility.Notably,FTPPM also inhibited drug-resistant Salmonella typhimurium from forming biofilms.More importantly,FTPPM effectively restored intestinal flora dis-orders induced by drug-resistant Salmonella typhimurium in mice.In summary,FTPPM significantly improved the solubility and oral bioavailability of florfenicol,enhancing its efficacy against drug-resistant Salmonella typhimurium both in vitro and in vivo.FTPPM represent a promising drug-resistant Salmonella typhimurium treatment for curbing bacterial resistance via oral administration.

Objective:To evaluate the effect of dexmedetomidine on Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor κB (NF-κB) signaling pathway in the hippocampus of mice with cognitive impairment after traumatic brain injury (TBI).Methods:Sixty specific pathogen-free healthy adult wild-type C57BL/6 mice, aged 21-23 months, weighing 28-34 g, were divided into 5 groups ( n=12 each) by a random number table method: sham operation + vehicle group (SV group), sham operation + dexmedetomidine group (SD group), TBI + vehicle group (TV group), TBI + dexmedetomidine group (TD group) and TBI + TLR4 inhibitor TAK-242 group (TT group). The modified Feeney free fall epidural impact method was used to establish a mild TBI model. At 30 min before model preparation, dexmedetomidine 25 μg/kg was intraperitoneally injected in SD group and TD group, TAK-242 10 mg/kg was intraperitoneally injected in TT group, and the equal volume of normal saline was intraperitoneally injected in SV group and TV group. Neurological severity scores (NSSs) were used to evaluate the neurological function at 1, 7 and 14 days after developing the model. The novel object recognition test (recognition index) and fear conditioning test (the percentage of freezing time related to context and sound) were used to evaluate the cognitive function of mice at 16 days after developing the model. The number and morphology of hippocampal neurons (NeuN-positive cells) and activated microglia (ionized calcium-binding adaptor molecule 1[IBA1]-positive cells) were measured by immunofluorescent staining. The expression of interleukin-1beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), TLR4, MyD88 and nuclear factor kappa B (NF-κB) was detected by Western blot. Results:Compared with SV group, the NSS was significantly increased, the recognition index was decreased, the percentage of freezing time related to context and sound was decreased, the number of NeuN-positive cells was decreased, the number of IBA1-positive cells was increased and the cell body area was enlarged, the total branch length and intersection points were decreased, and the expression of TLR4, MyD88, NF-κB, IL-1β, IL-6 and TNF-α was up-regulated in TV group ( P<0.05). Compared with TV group, the NSS was significantly decreased, the recognition index was increased, the percentage of freezing time related to context and sound was increased, the number of NeuN-positive cells was increased, the number of IBA1-positive cells was decreased and the cell body area was reduced, the total branch length and intersection points were increased, and the expression of TLR4, MyD88, NF-κB, IL-1β, IL-6 and TNF-α was down-regulated in TD group and TT group ( P<0.05). There was no statistically significant difference in the aforementioned parameters between TD group and TT group ( P>0.05). Conclusions:The mechanism by which dexmedetomidine mitigates TBI-induced cognitive impairment may be related to inhibition of the hippocampal TLR4/MyD88/NF-κB signaling pathway and reduction of neuroinflammatory responses in mice.

Objective:To evaluate the effect of dexmedetomidine on Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor κB (NF-κB) signaling pathway in the hippocampus of mice with cognitive impairment after traumatic brain injury (TBI).Methods:Sixty specific pathogen-free healthy adult wild-type C57BL/6 mice, aged 21-23 months, weighing 28-34 g, were divided into 5 groups ( n=12 each) by a random number table method: sham operation + vehicle group (SV group), sham operation + dexmedetomidine group (SD group), TBI + vehicle group (TV group), TBI + dexmedetomidine group (TD group) and TBI + TLR4 inhibitor TAK-242 group (TT group). The modified Feeney free fall epidural impact method was used to establish a mild TBI model. At 30 min before model preparation, dexmedetomidine 25 μg/kg was intraperitoneally injected in SD group and TD group, TAK-242 10 mg/kg was intraperitoneally injected in TT group, and the equal volume of normal saline was intraperitoneally injected in SV group and TV group. Neurological severity scores (NSSs) were used to evaluate the neurological function at 1, 7 and 14 days after developing the model. The novel object recognition test (recognition index) and fear conditioning test (the percentage of freezing time related to context and sound) were used to evaluate the cognitive function of mice at 16 days after developing the model. The number and morphology of hippocampal neurons (NeuN-positive cells) and activated microglia (ionized calcium-binding adaptor molecule 1[IBA1]-positive cells) were measured by immunofluorescent staining. The expression of interleukin-1beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), TLR4, MyD88 and nuclear factor kappa B (NF-κB) was detected by Western blot. Results:Compared with SV group, the NSS was significantly increased, the recognition index was decreased, the percentage of freezing time related to context and sound was decreased, the number of NeuN-positive cells was decreased, the number of IBA1-positive cells was increased and the cell body area was enlarged, the total branch length and intersection points were decreased, and the expression of TLR4, MyD88, NF-κB, IL-1β, IL-6 and TNF-α was up-regulated in TV group ( P<0.05). Compared with TV group, the NSS was significantly decreased, the recognition index was increased, the percentage of freezing time related to context and sound was increased, the number of NeuN-positive cells was increased, the number of IBA1-positive cells was decreased and the cell body area was reduced, the total branch length and intersection points were increased, and the expression of TLR4, MyD88, NF-κB, IL-1β, IL-6 and TNF-α was down-regulated in TD group and TT group ( P<0.05). There was no statistically significant difference in the aforementioned parameters between TD group and TT group ( P>0.05). Conclusions:The mechanism by which dexmedetomidine mitigates TBI-induced cognitive impairment may be related to inhibition of the hippocampal TLR4/MyD88/NF-κB signaling pathway and reduction of neuroinflammatory responses in mice.

Objective:To investigate the clinicopathological and molecular genetic features of high-grade astrocytomas with piloid features (HGAP).Methods:Clinical, histopathological and imaging data of 7 cases of HGAP diagnosed at the Neuropathology Center of Beijing Tiantan Hospital, Beijing, China from August 2023 to October 2024 were collected. The histopathological and molecular features for each case were analyzed.Results:Among the seven patients there were 4 males and 3 females, with the median age of 37 (34, 51) years. Patients exhibited various clinical symptoms and signs depending on the tumor′s location. Four tumors were located in the cerebellum, 2 in the supratentorial region, and 1 in the spinal cord. Magnetic resonance imaging showed that 6 of the 7 patients had cystic and solid lesions, with focal or nodular enhancement and relatively unclear boundaries. Histopathological features had a diverse morphological spectrum and extensive grading. Five cases displayed a pilocytic astrocytoma-like appearance with infiltrative growth patterns, while two cases presented glioblastoma-like morphology, containing locally anaplastic pleomorphic xanthoastrocytoma with minor pilocytic components. All tumors were diffusely positive for GFAP and Olig2, while 4 tumors exhibited partial or complete loss of ATRX. The Ki-67 proliferation index ranged from 2% to 40%. Next-generation sequencing showed that tumor cells most commonly harbored MAPK pathway gene mutations, and/or homozygous deletions of CDKN2A/B, and/or ATRX mutations. Among the 7 HGAP models, 3 cases showed the three types of molecular genetic variations, 1 case showed MAPK mutations and homozygous deletions of CDKN2A/B, 1 case had MAPK mutations and ATRX mutations, 1 case had only MAPK mutations, and 1 case showed no detectable molecular changes. DNA methylation clustering analyses showed that the median model prediction score was 0.94 (range, 0.85-0.99) for the 7 HGAP models. Five cases showed the MGMT promoter hypermethylation. Four patients received radiotherapy and concomitant temozolomide treatment after surgery, while three patients received no known treatments. At the last follow-up, seven patients were alive without any tumor, two patients had recurrence, and one patient was alive with the tumor.Conclusions:HGAP is relatively rare and predominantly occurs in adults. It has a wide histopathological spectrum and various histological grades, characterized by piloid astrocytoma-like and glioblastoma-like histological features. Its diagnosis relies on methylation clustering analysis. Most tumors harbor gene alterations in the MAPK signaling pathway, along with homozygous deletions of CDKN2A/B or ATRX mutations. The biological behavior is typically aggressive, while imaging and histological findings can be misleading. Therefore, clinicians need to increase their diagnostic awareness of this tumor and prevent missed diagnoses.

Objective:To propose a deep learning（DL）-based ultrasound imaging auxiliary tool for automatic segmentation and recognition of the brachial plexus（BP），and to enhance the accuracy and safety of clinical procedures.Methods:It was a multicenter study that collected 773 healthy subjects from Peking University Third Hospital and its branch campuses，the Third Medical Center of the Chinese PLA General Hospital，and Shanghai Eighth People's Hospital between August 2024 and February 2025. Brachial plexus（BP）images in the interscalene groove were captured used high-frequency ultrasound by senior sonographers，a dataset comprising 1 289 standardized images were constructed and the improved model（CHA-TransUNet）was trained. The test set was input into 6 different models（CHA-TransUNet，R50-Unet，TransUnet，SegFormer，SwinUnet，MISSFormer）for segmentation. Segmentation accuracy was evaluated using metrics including the Dice similarity coefficient（DSC），95% Hausdorff distance（HD95）and mean intersection over union（mIoU），and was compared with the segmentation results of 3 ultrasound physicians with varying experience levels（junior physicians and senior physicians）to validate the model's segmentation efficacy.Results:The CHA-TransUNet model established based on a dataset of 1 289 standardized images achieved segmentation results for the BP with a DSC of 90.15%，mIoU of 91.02%，and HD95 of 8.08. Its accuracy was higher than other mainstream models（DSC：90.15% vs. 87.60%，87.77%，81.35%，84.78%，84.55%），significantly better than junior physicians（DSC：90.15% vs. 68.73%， Z=-127.76， P<0.001），and approached the level of senior physician（DSC：90.15% vs. 86.15%， Z=-31.33， P=0.549）. The model demonstrated superior boundary recognition in complex anatomical structures（e.g.，C6/C7 nerve roots）compared to ultrasound physicians（junior and senior）（HD95：8.08 vs. 26.34，17.44，56.80）. Conclusions:This study proposes an analysis model for BP ultrasound images，CHA-TransUNet. This model achieves segmentation and recognition of the BP with relatively complex pathways and structures. The model exhibits high accuracy and stability，outperforming current mainstream network models and junior physicians while approaching the performance level of senior physicians. It assists junior physicians or trainees in more accurately identifying and localizing the BP.

Objective To investigate the value of minimum apparent diffusion coefficient(ADCmin)and delta apparent diffusion coefficient(dADC)of quantitative parameters of MR diffusion weighted imaging(DWI)in differentiating benign from stage Ⅰ malignant ovarian epithelial tumors.Methods A total of 112 patients with primary ovarian epithelial tumors confirmed by operation and pathology(43 benign tumors and 69 stage Ⅰ malignant tumors)were retrospectively selected.All patients underwent routine MRI and DWI before operation.The ADCmin and dADC of solid portion were measured and compared between the two groups.Logistic regression anal-ysis and receiver operating characteristic(ROC)curve were used to evaluate diagnostic performance of each parameter alone and in combination in differentiating ovarian epithelial benign and stage Ⅰ malignant tumors.Results The ADCmin was greater in benign tumors than that in stage Ⅰ malignant tumors,while dADC was smaller in benign tumors than that in stage Ⅰ malignant tumors(P＜0.05).Logis-tic regression analysis showed that ADCmin and dADC were independent risk factors for stage Ⅰ malignant tumors.With threshold of 1.183 × 10-3 mm2/s for ADCmin and 0.579 × 10-3 mm2/s for dADC,the area under the curve(AUC)was 0.802 and 0.857,sensitivity and specificity of 0.885,0.808,0.714,0.857,respectively.According to regression equation logit(P)=7.154+0.267 × dADC-1.016 X ADCmin,the AUC(0.951)was greater than that of single parameter,the sensitivity was 0.890,the specificity was 0.995.Conclusion ADCmin and dADC are useful for differentiating ovarian epithelial benign from stage Ⅰ malignant tumors,and ADCmin combined with dADC can improve the diagnose accuracy before operation.