In this study, we propose an automatic contour outlining method to measure the spatial resolution of homemade automatic tube current modulation (ATCM) phantom by outlining the edge contour of the phantom image, selecting the region of interest (ROI), and measuring the spatial resolution characteristics of computer tomography (CT) phantom image. Specifically, the method obtains a binarized image of the phantom outlined by an automated fast region convolutional neural network (AFRCNN) model, measures the edge spread function (ESF) of the CT phantom with different tube currents and layer thicknesses, and differentiates the ESF to obtain the line spread function (LSF). Finally, the values passing through the zeros are normalized by the Fourier transform to obtain the CT spatial resolution index (RI) for the automatic measurement of the modulation transfer function (MTF). In this study, this algorithm is compared with the algorithm that uses polymethylmethacrylate (PMMA) to measure the MTF of the phantom edges to verify the feasibility of this method, and the results show that the AFRCNN model not only improves the efficiency and accuracy of the phantom contour outlining, but also is able to obtain a more accurate spatial resolution value through automated segmentation. In summary, the algorithm proposed in this study is accurate in spatial resolution measurement of phantom images and has the potential to be widely used in real clinical CT images.
Phantoms, Imaging ; Tomography, X-Ray Computed/instrumentation* ; Algorithms ; Neural Networks, Computer ; Image Processing, Computer-Assisted/methods* ; Humans ; Polymethyl Methacrylate

OBJECTIVE: To introduce the etiology and prevention of bone cement implantation syndrome (BCIS). METHODS: The literature about BCIS at home and abroad in recent years was extensively reviewed, and the incidence, clinical manifestations, etiology, and prevention of BCIS were summarized and analyzed. RESULTS: The clinical manifestations of BCIS are diverse. The etiology of BCIS is not completely clarified, and it may be related to circulating methyl methacrylate-mediated model, embolus-mediated model, histamine release and hypersensitivity response, complement activation and multimodal model. BCIS prevention begins with the identification of high-risk patients in preoperative evaluation and communication between surgeon and anesthesiologist about the choice of implant type, surgical procedure, and technique to minimize the risk of cardiovascular complications in high-risk patients with multiple or severe risk factors or comorbidities. Preoperative assessment and optimization of a patient's cardiovascular reserve is also critical to prevent BCIS. CONCLUSION BCIS is a possible complication after hip joint arthroplasty, and its pathogenesis needs to be further research in order to provide new ideas for prevention and treatment.
Humans ; Bone Cements/adverse effects* ; Postoperative Complications/etiology* ; Arthroplasty, Replacement, Hip/adverse effects* ; Risk Factors ; Syndrome ; Methylmethacrylate/adverse effects*

OBJECTIVE: With the help of finite element analysis, to explore the effect of proximal humeral bone cement enhanced screw plate fixation on the stability of internal fixation of osteoporotic proximal humeral fracture. METHODS: The digital model of unstable proximal humeral fracture with metaphyseal bone defect was made, and the finite element models of proximal humeral fracture bone cement enhanced screw plate fixation and common screw plate fixation were established respectively. The stress of cancellous bone around the screw, the overall stiffness, the maximum stress of the plate and the maximum stress of the screw were analyzed. RESULTS: The maximum stresses of cancellous bone around 6 screws at the head of proximal humeral with bone cement enhanced screw plate fixation were 1.07 MPa for No.1 nail, 0.43 MPa for No.2 nail, 1.16 MPa for No.3 nail, 0.34 MPa for No.4 nail, 1.99 MPa for No.5 nail and 1.57 MPa for No.6 nail. These with common screw plate fixation were:2.68 MPa for No.1 nail, 0.67 MPa for No.2 nail, 4.37 MPa for No.3 nail, 0.75 MPa for No.4 nail, 3.30 MPa for No.5 nail and 2.47 MPa for No.6 nail. Overall stiffness of the two models is 448 N/mm for bone cement structure and 434 N/mm for common structure. The maximum stress of plate appears in the joint hole:701MPa for bone cement structure and 42 0MPa for common structure. The maximum stress of screws appeared at the tail end of No.4 nail:284 MPa for bone cement structure and 240.8 MPa for common structure. CONCLUSION Through finite element analysis, it is proved that the proximal humerus bone cement enhanced screw plate fixation of osteoporotic proximal humeral fracture can effectively reduce the stress of cancellous bone around the screw and enhance the initial stability after fracture operation, thus preventing from penetrating out and humeral head collapsing.
Humans ; Finite Element Analysis ; Bone Cements ; Polymethyl Methacrylate ; Biomechanical Phenomena ; Shoulder Fractures/surgery* ; Fracture Fixation, Internal ; Humeral Head ; Bone Screws ; Bone Plates

Xanthocillin is a unique natural product with an isonitrile group and shows remarkable antibacterial activity. In this study, the genome of an endophytic fungus Penicillium chrysogenum MT-40 isolated from Huperzia serrata was sequenced, and the gene clusters with the potential to synthesize xanthocillin analogues were mined by local BLAST and various bioinformatics analysis tools. As a result, a biosynthetic gene cluster (named for) responsible for the biosynthesis of xanthocillin analogues was identified by further heterologous expression of the key genes in Aspergillus oryzae NSAR1. Specifically, the ForB catalyzes the synthesis of 2-formamido-3-(4-hydroxyphenyl) acrylic acid, and the ForG catalyzes the dimerization of 2-formamido-3-(4-hydroxyphenyl) acrylic acid to produce the xanthocillin analogue N, N'-(1, 4-bis (4-hydroxyphenyl) buta-1, 3-diene-2, 3-diyl) diformamide. The results reported here provide a reference for further discovery of xanthocillin analogues from fungi.
Penicillium chrysogenum/genetics* ; Huperzia/microbiology* ; Acrylates ; Multigene Family

OBJECTIVE: To investigate the clinical efficacy of acrylic cement (PMMA) mixed with calcium sulfate combined with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic fracture (OVCF). METHODS: The clinical data of 191 patients with OVCF treated with PKP from January 2020 to March 2021 were retrospectively analyzed. Among them, 82 patients with 94 vertebral bodies were treated with PMMA mixed with calcium sulfate as the observation group, and 109 patients with 125 vertebral bodies were treated with pure PMMA as the control group. Among the 82 patients in the observation group, there were 16 males and 66 females, with a mean age of (75.35±11.22) years old, including 36 thoracic vertebrae and 58 lumbar vertebrae. In the control group, there were 109 patients, 22 males and 87 females, with an average age of (74.51±9.21) years old, including 63 thoracic vertebrae and 62 lumbar vertebrae. The visual analog scale (VAS) before operation and 1 day, 3 months and 1 year after operation were calculated. The Oswestry disability index (ODI), Cobb's angle, vertebral body height and the probability of postoperative bone cement leakage were used to analyze the efficacy of the two groups. RESULTS: All the patients were followed up for more than one year. Compared with the control group, there was no significant difference in operation time, bleeding volume and bone cement injection volume between the two groups(P>0.05), while the leakage rate of bone cement was significantly lower in the observation group (P<0.05). In addition, there was no significant difference in VAS, ODI, Cobb angle, and vertebral body height between the two groups before operation, and 1 day, 3 months, and 1 year after operation (P>0.05), but each index was improved compared with that before operation (P<0.05). CONCLUSION PMMA mixed with calcium sulfate has equivalent efficacy in treating OVCF than PMMA alone, but can effectively reduce the probability of cement leakage.
Female ; Male ; Humans ; Aged ; Aged, 80 and over ; Middle Aged ; Polymethyl Methacrylate ; Calcium Sulfate/therapeutic use* ; Osteoporotic Fractures/surgery* ; Bone Cements/therapeutic use* ; Kyphoplasty ; Retrospective Studies ; Lumbar Vertebrae/surgery*

There are many occupational risk factors in operating room work. Polymethyl methacrylate (PMMA) , as a kind of common bone filling and repairing material, is widely used in the fixation of artificial joints, oral braces and orthopedic prosthesis. However, PMMA will release methyl methacrylate (MMA) monomer when it is implanted into human tissues and polymerized to harden, which is toxic to the body. This paper analyzes harmful factors in using PMMA bone cement, and then explores corresponding occupational protection knowledge, in order to reduce the occurrence of occupational hazards related to PMMA bone cement and enhance the self-protection ability of the operation room medical staff.
Bone Cements/adverse effects* ; Humans ; Operating Rooms ; Polymethyl Methacrylate/adverse effects*

OBJECTIVE: To compare the clinical effect of microsurgery and endovascular embolization in the treatment of spinal dural arteriovenous fistula (SDAVF) by meta-analysis. METHODS: A systematic review was performed to retrieve all relevant literature about surgical treatment or endovascular embolization of SDAVF up to December 2019 through PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials Results, CNKI, Wanfang Data, and SinoMed. The Chinese and English key words included: "SDAVF", "spinal dural arteriovenous fistula", "spinal AVM", "spinal vascular malformation and treatment". The included studies were evaluated using the Newcastle-Ottawa scale. The early failure rate, long-term recurrence, neurological recovery, and complications were evaluated and the clinical effects of the two methods in the treatment of SDAVF were compared by using RevMan 5.3 software. And a further subgroup analysis of the therapeutic effect of endovascular embolization with different embolic agents was conducted. RESULTS: A total of 46 studies involving 1 958 cases of SDAVF were included, in which 935 cases were treated by microsurgery and 1 023 cases were treated by endovascular embolization. The funnel plot demonstrated that there was no publication bias. The results of meta-analysis showed that the incidence of early surgical failure was lower than that of endovascular embolization (OR=0.20, 95%CI: 0.13-0.30, P < 0.05), and the long-term recurrence was also lower than that of endovascular embolization (OR=0.36, 95%CI: 0.22-0.58, P < 0.05). The improvement of neurological function in the surgical patients is significantly higher than that in the patients treated with endovascular embolization (OR=2.86, 95%CI: 1.36-5.99, P < 0.05). There was no significant difference in the occurrence of complications in these two groups (OR=1.52, 95%CI: 0.88-2.64, P=0.14). In the cases of endovascular embolization, the risk of treatment failure or recurrence was higher with Onyx glue than with n-butyl 2-cyanoacrylate (NBCA), and the difference was statistically significant (OR=4.70, 95%CI: 1.55-14.28, P < 0.05). CONCLUSION Although the treatment of dural arteriovenous fistulas by intravascular embolization has been widely used, the clinical effect of microsurgery is still better than that of endovascular embolization. Large scale and high-quality randomized controlled trials are required to validate the efficacy and safety of endovascular treatment in SDAVF patients.
Central Nervous System Vascular Malformations/surgery* ; Embolization, Therapeutic/methods* ; Enbucrilate/therapeutic use* ; Endovascular Procedures/methods* ; Humans ; Microsurgery/methods* ; Retrospective Studies ; Treatment Outcome

Bone cement, consisting of polymethyl methacrylate, is a bioinert material used for prothesis fixation in joint arthroplasty. To treat orthopedic infections, such as periprosthetic joint infection, antibiotic-loaded bone cement (ALBC) was introduced into clinical practice. Recent studies have revealed the limitations of the antibacterial effect of ALBC. Moreover, with the increase in high infection risk patients and highly resistant microbes, more researches and modification of ALBC are required. This paper reviewed latest findings about ALBC for most popular and destructive pathogens, summarized the influence of antibiotic kind, drug dosage, application method, and environment towards characteristic of ALBC. Subsequently, new cement additives and clinical applications of ALBC in joint arthroplasty were also discussed.
Anti-Bacterial Agents/therapeutic use* ; Arthroplasty, Replacement, Knee ; Bone Cements ; Humans ; Polymethyl Methacrylate ; Prosthesis-Related Infections/drug therapy*

OBJECTIVES: The need for proper wound closure is of paramount importance after any intra-oral surgery. Various wound closure techniques have been described in literature using traditional non-absorbable suture materials. These include like synthetic absorbable sutures, surgical staples and tissue adhesives. Cyanoacrylates are among the most commonly used biocompatible tissue adhesives. To evaluate and compare intraoral wound healing using 3-0 silk sutures and n-butyl-2-cyanoacrylate after alveoloplasty.MATERIALS AND METHODS: A total of 20 patients requiring bilateral alveoloplasty in the same arch (upper or lower) were included in this study. Patients with any pre-existing pathology or systemic disease were excluded. After alveoloplasty was performed, the wound was closed using 3-0 braided silk sutures on one side, and using n-butyl-2-cyanoacrylate bio adhesive on the other side. Patients were evaluated based on the following parameters: time required to achieve wound closure; the incidence of immediate and postoperative hemostasis; the time to the use of the first rescue medication; the side where pain first arises; and the side where wound healing begins first.RESULTS: Compared to 3-0 silk sutures, cyanoacrylate demonstrated better hemostatic properties, reduced operative time, reduced postoperative pain and better wound healing.CONCLUSION: These data suggest that cyanoacrylate glue is an adequate alternative to conventional sutures to close the surgical wound after alveoloplasty, and better than are 3-0 silk sutures.
Adhesives ; Alveoloplasty ; Cyanoacrylates ; Enbucrilate ; Hemostasis ; Humans ; Incidence ; Operative Time ; Pain, Postoperative ; Pathology ; Silk ; Sutures ; Tissue Adhesives ; Wound Closure Techniques ; Wound Healing ; Wounds and Injuries

OBJECTIVE: From the perspective of clinical application to analyze the effectiveness and reliability of CPC/PMMA bone cement in percutaneous kyphoplasty (PKP) for the treatment of elderly patients with osteoporotic thoracolumbar fractures. METHODS: A retrospective analysis was performed on 62 patients with osteoporotic compression fracture of single-vertebral thoracic or lumbar segment who underwent PKP surgery and had a bone density less than or equal to -3.0 SD from February 2016 to December 2016. Among them, 23 patients were in CPC/PMMA group, with an average age of (77.6±2.2) years old, 39 patients in PMMA group, with an average age of (77.1±1.1) years old. The indexes between two groups were compared, including the visual analogue scale (VAS), height ratio of anterior vertebra (AVHR), local Cobb angle, cement leakage, new adjacent vertebral fracture(NAVF). RESULTS: There were no significant difference in gender, age, follow-up time and preoperative VAS, AVHR, local Cobb angle between two groups (>0.05), at the 1 day after operation, VAS, AVHR, local Cobb angle in all patients got obvious improvement (<0.05), which was no significant difference at 1 day after operation and final follow-up (>0.05). At the same time, there was no statistically significant difference in the incidence of new adjacent vertebral fracture and cement leakage (>0.05). The pain in both groups continued to improve at follow up after operation (<0.05), the local Cobb angle increased (<0.05) and AVHR decreased slightly (<0.05). However, the images of conventional methods (X-ray or CT) could not find signs about CPC degeneration and new bone ingrowth. CONCLUSION CPC/PMMA composite bone cement is safe and reliablein PKP for treatment of elderly patients with osteoporotic thoracolumbar fractures, which can effectively relieve pain and maintain vertebral body stability. It has the same curative effect as PMMA bone cement. It was worthy to research more in future, although no direct evidences support the CPC/PMMA composite bone cement can reduce the incidence of adjacent vertebral fracture, CPC degeneration or new bone ingrowth.
Aged ; Bone Cements ; Dinucleoside Phosphates ; Fractures, Compression ; Humans ; Kyphoplasty ; Osteoporotic Fractures ; Polymethyl Methacrylate ; Reproducibility of Results ; Retrospective Studies ; Spinal Fractures ; Treatment Outcome ; Vertebroplasty