Aim To explore whether platelet-derived growth factor C(PDGFC)derived from cancer-associat-ed fibroblasts(CAFs)can promote resistance of breast cancer cells to doxorubicin(DOX)and the underlying mechanisms.Methods CAFs and normal fibroblasts(NFs)were extracted from freshly resected breast cancer tissue and adjacent normal breast tissue respec-tively.Conditioned medium(CM)from CAFs and NFs was collected and co-cultured with breast cancer cells.Cell proliferation and toxicity were assessed using a Cell Counting Kit-8(CCK-8).The expression of PDG-FC in CAFs,NFs and corresponding CM was detected by Western blot and ELISA respectively.The influence of CAFs-CM on intracellular doxorubicin content in breast cancer cells was observed by fluorescence mi-croscopy.The impact of CAFs-CM on apoptosis-related proteins BAX and BCL2 was predicted and valifated u-sing the Starbase database and Western blot.The changes in ROS levels,mitochondrial membrane po-tential,and mitochondrial membrane proteins TOM20 and COX Ⅳ in breast cancer cells were measured using DCFH-DA fluorescence staining,JC-1 assay,and Western blot.Results CAFs-CM decreased the intra-cellular doxorubicin content and inhibited the sensitivi-ty of breast cancer cells to doxorubicin.Additionally,the expression of apoptosis protein BAX decreased while the anti-apoptotic protein BCL2 increased in breast cancer cells cultured with CAFs-CM.Further-more,CAFs-CM led to decreased ROS levels and in-creased mitochondrial membrane potential in breast cancer cells accompanied with elevated expression of mitochondrial membrane proteins TOM20 and COX Ⅳ.Further study found that PDGEF was highly expressed in CAFs and CAFs-CM,recombinant human PDGFC produced resistance of breast cancer cells to DOX simi-lar to CAFs-CM,and the specific inhibitors of PDGFRα significantly inhibited CAFs-CM.Further mechanistic studies revealed that PDGFC in CAFs-CM induced chemoresistance by activating PI3K-mTOR signaling pathway.Conclusion PDGFC secreted by CAFs promotes doxorubicin resistance in breast cancer cells through PI3K-mTOR signaling pathway,which provides a new perspective for the development of anti-cancer drugs targeting CAFs.

BACKGROUND:The treatment of distal tibial comminuted fractures with soft tissue injury has always been challenging.The new retrograde tibial nailing and supercutaneous locking plate are important treatment methods,but their strain and stress shielding at the fracture end during different periods of fracture healing and different load conditions have not been reported. OBJECTIVE:To explore the biomechanical stability of retrograde tibial nailing and supercutaneous locking plate in different periods of fracture healing by finite element analysis to offer a scientific foundation for clinical application and rehabilitation exercise. METHODS:The finite element model of distal tibial comminuted fracture was established by utilizing the CT data of the tibia from a 40-year-old healthy male.Retrograde tibial nailing,supercutaneous locking plate,and callus models were assembled in accordance with the principle of fracture fixation.The finite element analysis was performed using ANSYS software to compare the displacement of the fracture end,the stress shielding of the tibia,the stress of the callus,and the stress distribution of the tibia and the fixation device during different periods of fracture healing. RESULTS AND CONCLUSION:(1)The relative displacement of the tibial fracture decreased gradually with the healing of the fracture,and the displacement decreased significantly after 3 months.At 0 and 1 months after operation,the vertical displacement and total displacement of the supercutaneous locking plate group were higher than those in the retrograde intramedullary nail group.The Z-axis displacement(horizontal medial and lateral displacement)of the two fixation methods was more obvious than the X-axis and Y-axis,and the Z-axis displacement of supercutaneous locking plate group was the most obvious.The maximum Z-axis displacement of the two fixation methods was located on the outside of the tibia,and the minimum displacement was located on the inside of the tibia.(2)The stress shielding rate at different periods of fracture healing gradually decreased with time.The stress shielding rate of the retrograde intramedullary nail was higher than that of the supercutaneous locking plate at different stages of fracture healing.After 3 months,the stress shielding rate of the supercutaneous locking plate was reduced to about 4%,and the stress shielding rate of the retrograde intramedullary nail was reduced to about 40%.(3)The stress of the stress concentration site of the callus in the two fixation methods increased with the increase of the load,and the stress of the callus in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The maximum stress distribution of the callus was approximately equally distributed among the two modes of fixation,both in the lateral portion of the tibia.(4)As the fracture healed,the maximum stress of the tibia in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was always greater than that in the retrograde intramedullary nail group.The average stress of the maximum stress area of the tibia in the supercutaneous locking plate group under 1 500 N load was 285 MPa,while that in the retrograde intramedullary nail group was 26 MPa.(5)As the fracture healed,the stress of the fixation device in the two groups decreased gradually,and the stress in the supercutaneous locking plate group was significantly higher than that in the retrograde intramedullary nail group.After 3 months,the stress of the two fixation devices decreased significantly.(6)It is indicated that in the early stage of fracture healing,the strain on the fracture end in the retrograde intramedullary nail group is small,and the maximum stress of the tibia is moderate,allowing early loaded.The fractured ends in the supercutaneous locking plate group had too large strain and too large maximum stress of the tibia,which needed to be partially loaded under protection and could not be fully loaded.In the middle and late stages of fracture healing,the tibial retrograde intramedullary nail and the supercutaneous locking plate could be completely loaded,and the stress shielding rate of the supercutaneous locking plate was significantly lower than the tibial retrograde intramedullary nail.

Objective To explore the value of droplet digital polymerase chain reaction(ddPCR)in the etiological diagnosis of severe acute pancreatitis(SAP)patients with suspected bloodstream infection(BSI).Methods SAP patients admitted to the department of critical care medicine in a hospital July to September 2022 were enrolled.When BSI was suspected,venous blood was collected for both ddPCR detection and blood culture(BC)with antimi-crobial susceptibility testing(AST)simultaneously.The time required for two detection methods was recorded,and the detection results of ddPCR and BC were compared.The etiological diagnostic efficacy of ddPCR was calculated,and the correlation between the value of pathogen load detected by ddPCR and the level of infection parameters was explored.Results A total of 22 patients were included in the analysis,and 52 venous blood specimens were collec-ted for detection.BC revealed 17 positive specimens(32.7％)and 29 pathogenic strains,while ddPCR showed 41 positive specimens(78.8％)and 73 pathogenic strains.Detection time required for ddPCR was significantly lower than that of BC([0.16±0.03]days vs[5.92±1.20]days,P＜0.001).Within the detection range of ddPCR and taking BC results as the gold standard,the sensitivity and specificity of ddPCR were 80.0％and 28.6％,respective-ly.With the combined assessment of BSI based on non-blood specimen microbial evidence within a week,the sensi-tivity and specificity of ddPCR detection increased to 91.9％and 76.9％,respectively.ddPCR detected resistance genes of blaKPC,blaNDM/IMP,VanA/VanM,and mecA from 19,9,6,and 5 specimens,respectively.Correlation analysis showed a positive correlation between pathogen load and levels of C-reactive protein as well as procalcitonin(r=0.347,0.414,P＜0.05).Conclusion As a supplementary detection method for BC in BSI diagnosis,ddPCR has the advantages of higher sensitivity and shorter detection time,and is worthy of further exploration in clinical application.

Objective To explore the safety and effectiveness of catheter aspiration combined with catheterization thrombolysis in the treatment of acute renal infarction(ARI),so as to provide reference for the treatment of this disease.Methods A retrospective analysis was conducted on the clinical and follow-up data of 11 ARI patients treated with catheter aspiration combined with catheter thrombolysis at our hospital during Jan.2019 and Jun.2023.Results Among the 11 patients,upon admission,7 manifested with abdominal pain,5 with lumbar pain,5 with nausea,and 1 with fever.All patients were successfully treated with catheter aspiration combined with catheterization and thrombolysis.After thrombolysis,computed tomography angiography(CTA)showed the renal artery trunk and branch vessels.In 11 patients,the renal artery,branch artery and splenic artery branch vessels were patent.D2 aggregates returned to the normal level 1 month after surgery(＜0.5 mg/L).During the follow-up of 3,6,12 months,no previous symptoms were observed.Ultrasound or CTA showed that the renal artery remained unobstructed.Conclusion The use of catheter aspiration combined with catheter thrombolysis for the treatment of ARI caused by renal artery thrombosis is effective,minimally invasive,and worth clinical promotion.

As interstitial collagen,type Ⅲ collagen(Col Ⅲ)does not express in normal glomeruli.However,in Col Ⅲ nephropathy,a large amount of Col Ⅲ deposit in the mesangial and subendothelial area of the glomeruli.IgA nephropathy with Col Ⅲ deposition was extremely rare.In this article,we reported two cases of such disease.After treating with immunosuppressive agents or traditional Chinese medicine decoction,the renal function of the two patients remained stable and the urinary protein levels reduced significantly.

Amino acid surfactants (AAS) have excellent properties such as low toxicity,antibacterial,mildness,and corrosion resistance. In recent years,they have been widely applied in the field of daily chemicals,food and pharmaceutical industry. It is pointed out that the structure at molecular level largely affects the physical and chemical properties of AAS materials. In this work,the structures of solid-state N-lauroyl-L-alanine (NLLA) including intermolecular interactions,molecular local dynamics and molecular assembly were investigated by a variety of solid-state nuclear magnetic resonance (SSNMR) techniques. Based on 2D 1H-1H double quantum-single quantum (2D 1H-1H DQ-SQ),1H-1H DQ sideband pattern and molecular simulation,it was found that there was a stable intermolecular hydrogen bond formed between the carboxyl units of two NLLA molecules. Combined with the study of 2D frequency switched Lee—Goldberg heteronuclear correlation (2D 13C-1H FSLG-HETCOR) and 13C T1,another type of hydrogen bond was probed,which existed between amide units of neighboring molecules. In addition,the conformation of alkyl chain ends was investigated. According to 1D 13C{1H}cross polarization/magic angle spinning (CP/MAS) and 2D 13C-1H FSLG-HETCOR spectra,it was revealed that the alkyl-chain ends had both gauche and trans conformations. Moreover,the trans conformation showed two distinct 13C chemical shifts,originated from two NLLA molecular assembly forms. Accordingly,two NLLA molecular assembly structures were suggested which were transoid form and cisoid form. This work provided a SSNMR investigation strategy for characterizing the molecular local structure and dynamics of AAS materials,which helped task of researching and developing materials with improved chemical and physical properties.

Objective To evaluate the clinical safety and efficacy of endovascular stent implantation in treating superior mesenteric artery stenosis.Methods The clinical data of 21 patients with superior mesenteric artery stenosis,who received endovascular stent implantation at the Chengdu Municipal Seventh People's Hospital of China from May 2019 to May 2023,were retrospectively analyzed,and its curative effect was evaluated.Results Successful endovascular stent implantation was accomplished in all the 21 patients.After surgery,the abdominal pain disappeared in all patients.All patients were followed up for 3-24 months.No obvious abdominal pain or other symptoms was observed in 19 patients.Two patients presented with abdominal pain again,and examination revealed that it was caused by an in-stent restenosis,and the abdominal pain disappeared after another interventional procedure.No severe complications such as intestinal necrosis or death occurred in all patients.Conclusion For superior mesenteric artery stenosis,endovascular stent implantation is a safe,effective and minimally-invasive treatment.

Infectious bone defect is bone defect with infection or as a result of treatment of bone infection. It requires surgical intervention, and the treatment processes are complex and long, which include bone infection control,bone defect repair and even complex soft tissue reconstructions in some cases. Failure to achieve the goals in any step may lead to the failure of the overall treatment. Therefore, infectious bone defect has been a worldwide challenge in the field of orthopedics. Conventionally, sequestrectomy, bone grafting, bone transport, and systemic/local antibiotic treatment are standard therapies. Radical debridement remains one of the cornerstones for the management of bone infection. However, the scale of debridement and the timing and method of bone defect reconstruction remain controversial. With the clinical application of induced membrane technique, effective infection control and rapid bone reconstruction have been achieved in the management of infectious bone defect. The induced membrane technique has attracted more interests and attention, but the lack of understanding the basic principles of infection control and technical details may hamper the clinical outcomes of induced membrane technique and complications can possibly occur. Therefore, the Chinese Orthopedic Association organized domestic orthopedic experts to formulate An evidence-based clinical guideline for the treatment of infectious bone defect with induced membrane technique ( version 2023) according to the evidence-based method and put forward recommendations on infectious bone defect from the aspects of precise diagnosis, preoperative evaluation, operation procedure, postoperative management and rehabilitation, so as to provide useful references for the treatment of infectious bone defect with induced membrane technique.

The data on reported adverse events of ventilators in the U.S.Food and Drug Administration(FDA)Medical Device Manufacturer and User Facility Device Experience(MAUDE)database were searched from January 1,2022 to December 31,2022,of which the data on ventilator fatal adverse events were extracted and statistically analyzed with Python.The main causes for ventilator fatal adverse events were pointed out including degradation of noise-reducing foams,improper use and ventilator malfunction,and some suggestions were put forward accordingly from the aspects of material,manufacturer,user,maintainer and supervisor.References were provided for utilization management and adverse events control for other medical devices.[Chinese Medical Equipment Journal,2023,44(10):86-90]

Diabetic ulcer(DU) is a chronic and refractory ulcer which often occurs in the foot or lower limbs. It is a diabetic complication with high morbidity and mortality. The pathogenesis of DU is complex, and the therapies(such as debridement, flap transplantation, and application of antibiotics) are also complex and have long cycles. DU patients suffer from great economic and psychological pressure while enduring pain. Therefore, it is particularly important to promote rapid wound healing, reduce disability and mortality, protect limb function, and improve the quality of life of DU patients. By reviewing the relevant literatures, we have found that autophagy can remove DU wound pathogens, reduce wound inflammation, and accelerate ulcer wound healing and tissue repair. The main autophagy-related factors microtubule-binding light chain protein 3(LC3), autophagy-specific gene Beclin-1, and ubiquitin-binding protein p62 mediate autophagy. The traditional Chinese medicine(TCM) treatment of DU mitigates clinical symptoms, accelerates ulcer wound healing, reduces ulcer recurrence, and delays further deterioration of DU. Furthermore, under the guidance of syndrome differentiation and treatment and the overall concept, TCM treatment harmonizes yin and yang, ameliorates TCM syndrome, and treats underlying diseases, thereby curing DU from the root. Therefore, this article reviews the role of autophagy and major related factors LC3, Beclin-1, and p62 in the healing of DU wounds and the intervention of TCM, aiming to provide reference for the clinical treatment of DU wounds and subsequent in-depth studies.
Humans ; Ulcer/therapy* ; Medicine, Chinese Traditional ; Beclin-1 ; Quality of Life ; Wound Healing ; Diabetes Complications ; Autophagy ; Diabetic Foot/drug therapy* ; Diabetes Mellitus/genetics*