Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

To explore the role of the "Clinical Practice Guidelines" column and others in the Medical Joumnal of Peking Union Medical College Hospital (Med J PUMCH) in promoting diseiplinary development.

OBJECTIVE: To study the in vitro and in vivo antitumor effects of the polysaccharide of Alocasia cucullata (PAC) and the underlying mechanism. METHODS: B16F10 and 4T1 cells were cultured with PAC of 40 µg/mL, and PAC was withdrawn after 40 days of administration. The cell viability was detected by cell counting kit-8. The expression of Bcl-2 and Caspase-3 proteins were detected by Western blot and the expressions of ERK1/2 mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR). A mouse melanoma model was established to study the effect of PAC during long-time administration. Mice were divided into 3 treatment groups: control group treated with saline water, positive control group (LNT group) treated with lentinan at 100 mg/(kg·d), and PAC group treated with PAC at 120 mg/(kg·d). The pathological changes of tumor tissues were observed by hematoxylin-eosin staining. The apoptosis of tumor tissues was detected by TUNEL staining. Bcl-2 and Caspase-3 protein expressions were detected by immunohistochemistry, and the expressions of ERK1/2, JNK1 and p38 mRNA were detected by qRT-PCR. RESULTS: In vitro, no strong inhibitory effects of PAC were found in various tumor cells after 48 or 72 h of administration. Interestingly however, after 40 days of cultivation under PAC, an inhibitory effect on B16F10 cells was found. Correspondingly, the long-time administration of PAC led to downregulation of Bcl-2 protein (P<0.05), up-regulation of Caspase-3 protein (P<0.05) and ERK1 mRNA (P<0.05) in B16F10 cells. The above results were verified by in vivo experiments. In addition, viability of B16F10 cells under long-time administration culture in vitro decreased after drug withdrawal, and similar results were also observed in 4T1 cells. CONCLUSIONS Long-time administration of PAC can significantly inhibit viability and promote apoptosis of tumor cells, and had obvious antitumor effect in tumor-bearing mice.
Mice ; Animals ; Alocasia/metabolism* ; MAP Kinase Signaling System ; Caspase 3/metabolism* ; Apoptosis ; RNA, Messenger/metabolism*

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) functions as a key regulator in inflammation and cell death and is involved in mediating a variety of inflammatory or degenerative diseases. A number of allosteric RIPK1 inhibitors (RIPK1i) have been developed, and some of them have already advanced into clinical evaluation. Recently, selective RIPK1i that interact with both the allosteric pocket and the ATP-binding site of RIPK1 have started to emerge. Here, we report the rational development of a new series of type-II RIPK1i based on the rediscovery of a reported but mechanistically atypical RIPK3i. We also describe the structure-guided lead optimization of a potent, selective, and orally bioavailable RIPK1i, 62, which exhibits extraordinary efficacies in mouse models of acute or chronic inflammatory diseases. Collectively, 62 provides a useful tool for evaluating RIPK1 in animal disease models and a promising lead for further drug development.

BACKGROUND:In the treatment of skin trauma with active repair,tissue engineering techniques are needed to generate new tissue to replace necrotic tissue.Skin scaffolds have a good application prospect in the field of wound repair.Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division.However,the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds. OBJECTIVE:To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites,and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters. METHODS:Oxidized nanocellulose whiskers at 10%concentration were extracted from Humulus scandens and then compounded with 5%gelatin to obtain gelatin/oxidized nanocellulose composites.The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined.Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material.Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters(filling gap 1.5-2.5 mm,uniform distribution of 0.1 mm;air pressure of 160-200 kPa),and the skin scaffold with a three-dimensional porous structure was prepared.The compressive performance of the skin scaffold was tested and compared with the finite element analysis results.The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. RESULTS AND CONCLUSION:(1)The elastic modulus of 5%gelatin was increased by 8.84 times by adding 10%oxidized nanocellulose whisker.A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa.When the filling gap increased from 1.5 mm to 2.5 mm,the theoretical porosity of the scaffold increased from 33%to 60%,but the compressive strength decreased from 230 000 Pa to 95 000 Pa.(2)These findings showed that the skin scaffold with theoretical porosity of 50%and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap.The scaffold had a clear three-dimensional porous structure.

Objective:To summarize the imaging features of severe unilateral transverse sinus and sigmoid sinus thromboses, and evaluate the efficacy and safety of intravascular interventional therapy in them.Methods:Thirty-seven patients with severe unilateral transverse sinus and sigmoid sinus thromboses clinically mainly manifested as intracranial hypertension and accepted endovascular intervention in Department of Interventional Radiology, First Affiliated Hospital of Zhengzhou University from June 2012 to September 2022 were chosen; their clinical data were retrospectively analyzed and imaging features were summarized. Short-term efficacy was evaluated according to blood flow restoration degrees and pressure gradient reduction in the occlusive sinus and modified neurological symptoms before and after endovascular intervention. Hospitalized complications were observed; safety and long-term efficacy were evaluated according to postoperative clinical follow-up and imaging results 6-12 months after endovascular intervention.Results:(1) Preoperative brain MRI and (or) CT showed different degrees of swelling of the brain tissues, with the affected side as the target; mixed signals/density shadow could be seen in the blocked transverse sinus and sigmoid sinus; venous cerebral infarction or post-infarction cerebral hemorrhage could be combined in some patients. MRV, CTV and DSA showed poor or completely occluded transverse sinus and sigmoid sinus while normal in the contralateral side; obvious thrombus filling-defect was observed in the occluded venous sinus after mechanical thrombolysis. (2) Occlusive sinus blood flow was restored in all patients after endovascular intervention, and pressure gradient of the occlusive segment decreased from (16.6±3.3) mmHg before to (2.8±0.8) mmHg after endovascular intervention. Before discharge, clinical symptoms of all patients were significantly improved (modified Rankin scale [mRS] scores of 0 in 30 patients, 1 in 5 patients, 2 in 1 patient and 3 in 1 patient), and 2 patients had unilateral limb movement disorder (muscle strength grading III and IV, respectively). All patients received clinical follow-up for (9.6±3.0) months. At the last follow-up, neurological function obviously improved compared with that before endovascular intervention, without new neurosystem-related symptoms (mRS scores of 0 in 30 patients, 1 in 6, and 2 in 1 patient). In 34 patients received MRV or DSA follow-up, 28 had complete recanalization of occlusive sinus and 6 had partial recanalization, without obvious stenosis or recurrent occlusion.Conclusions:Severe unilateral transverse sinus and sigmoid sinus thrombosis can cause local intracranial venous blood stasis, and then cause "increased regional venous sinus pressure", which is manifested as unilateral brain tissue swelling and even venous cerebral infarction or post-infarction cerebral hemorrhage. Early diagnosis and endovascular intervention can obviously improve the prognosis of these patients, enjoying good safety.

Objective:To explore the efficacy of long intramedullary nails versus short intramedullary nails in the treatment of AO/OTA 31-A3 intertrochanteric fractures.Methods:A retrospective analysis was conducted on 60 patients with AO/OTA 31-A3 intertrochanteric femur fractures treated between March 2019 and August 2022. The patients were randomly divided into two groups (the long nail group and the short nail group). Thirty-four patients were treated with long intramedullary nails, including 16 males and 18 females, aged 68.41±17.84 years old (range 31-96 years). Twenty-six patients were treated with short intramedullary nails, including 13 males and 13 females, aged 72.23±13.97 years old (range 31-90 years). The causes of injury, fracture classification (AO/OTA classification), intraoperative blood loss, operation time, fracture healing time, imaging indexes (fracture reduction quality, postoperative neck trunk angle, and medial support), Harris score of the hip joint at the last follow-up, one-year mortality rates and complications were compared between the two groups.Results:The follow-up time was 24.26±6.67 months in the long nail group and 24.31±5.60 months in the short nail group, and the general information of the two groups were comparable. Between the long nail and short nail group, the intraoperative blood loss was 281.47±235.28 ml vs. 121.92±84.14 ml and the operation time was 110.44±24.63 min vs. 81.15±28.54 min with significant differences ( P<0.05). While the length of hospital stay was 12.35±4.81 d vs. 10.89±4.30 d, the good rate of fracture reduction was 55.9% vs. 61.53%, the fracture healing time was 120.44±16.43 d vs. 128.07±18.33 d, the presence rate of medial support was 67.6% vs. 79.4%, and the excellent rate of Harris score was 65.4% vs. 65.4% with no significant difference between the two groups ( P>0.05). One-year mortality rates was 5.3% vs. 7.1% and complications was 11.7% vs. 15.4% with no significant difference between the two groups ( P>0.05). Conclusion:Both long intramedullary nails and short intramedullary nails are effective in the treatment of AO/OTA 31-A3 intertrochanteric femur fractures. However, surgical time and intraoperative blood loss was less in the short nail group.

Objective To investigate the anti-inflammatory effects of Bupi Yichang Pills on mice with experimental colitis and its potential mechanism of action.Methods Dextran sulfate sodium(DSS)was used to model the experimental colitis,and low-,medium-and high-doses of Bupi Yichang Pills(1.5,3.0,6.0 g·kg-1·d-1)and Mesalazine(300 mg·kg-1·d-1)were fed at the same time.Mice were observed for general behavior and weighed.Hematoxylin-eosin staining was used to observe the pathological injury of colonic tissues.qPCR and ELISA were used to detect the levels of inflammatory cytokines(TNF-α,IL-1β,IL-6,IL-10,IL-35 and TGF-β1),qPCR and Western Blot were used to detect the mRNA and protein levels of glucose transporters and glycolytic kinases.Results Low-,medium-and high-doses of Bupi Yichang Pills significantly down-regulated disease activity index in colitis mice(P＜0.05,P＜0.01).The body mass and colon length were significantly increased,while colon mass,colon mass index and unit colon mass index were significantly reduced(P＜0.05,P＜0.01),and ulcer formation and inflammatory cell infiltration in colonic tissue were significantly improved.In addition,medium-and high-doses of Bupi Yichang Pills significantly down-regulated the mRNA levels and concentrations of pro-inflammatory cytokines including TNF-α,IL-1β and IL-6(P＜0.01),while significantly up-regulated the mRNA levels and concentrations of anti-inflammatory cytokines such as IL-10,IL-35 and TGF-β1(P＜0.01).We further found that high-dose of Bupi Yichang Pills significantly down-regulated the mRNA and protein expressions of glucose transporters(Glut1,Glut2,Glut4)and glycolytic kinases(HK2,Aldolase A,PKM2)in colonic tissue(P＜0.01).Conclusions Bupi Yichang Pills effectively alleviates DSS-induced experimental colitis,and its specific mechanism of action is related to the improvement of glycolytic metabolic pathways and the regulation of inflammatory cytokine expression.

Objective To explore the impact of contrast agent concentration on the excimer laser's effect on plaque ablation.Methods Using a laser catheter with a diameter of 0.9 mm,we conducted plaque model ablation experiments employing a 308-nanometer xenon chloride excimer laser.During the excimer laser ablation process,five groups were formed based on the injected contrast agent concentrations:a saline group,25%concentration group,50%concentration group,75%concentration group,and 100%concentration group.Optical coherence tomography was utilized to assess the changes in plaque lumen area after excimer laser ablation,evaluating the impact of contrast agent concentration on the excimer laser's ablation efficacy.Simultaneously,a water manometer was used to measure the shockwave pressure generated by the excimer laser in liquids with different contrast agent concentrations,aiming to explore the correlation between the shockwave pressure of the excimer laser and its ablative effect.Results The ablation areas in the 75%concentration group and the 100%concentration group were similar(P＞0.05),both exceeding those in the 50%concentration contrast agent group,25%concentration group,and saline group(all P＜0.001).Specifically,the ablation area in the 50%concentration group was significantly larger than that in the 25%concentration group and saline group(both P＜0.001),while the 25%concentration group was larger than the saline group(P＜0.001).The influence of contrast agent concentration on the shockwave pressure of the excimer laser exhibited a similar trend.Additionally,there was a significant positive correlation between the shockwave pressure generated by the excimer laser and its ablation area(r=0.9987,P＜0.001).Conclusions The intensity of excimer laser ablation on plaque tissue can be modulated by altering the contrast agent concentration.These findings offer guidance for the application of excimer laser in conjunction with contrast agent injection techniques in the treatment of coronary artery disease.