BACKGROUND:Currently,pedicle screw fixation technology is recognized as the gold standard for lumbar posterior fusion surgery.However,this technique is associated with several complications such as suboptimal screw placement,loosening,and fracture.Addressing these issues,it requires a thorough investigation into the mechanical properties of screw reinsertion to optimize surgical procedures and enhance success rates and safety.OBJECTIVE:By combining finite element analysis with biomechanical experiments,this study aims to compare and analyze the mechanical performance of traditional trajectory pedicle screws during multiple extraction processes.The goal is to reveal patterns in screw extraction strength over repeated withdrawals,providing scientific insights into the safety and effectiveness of pedicle screw reinsertion for clinicians.METHODS:Based on CT scan data,a three-dimensional reconstruction of the L4 vertebra model was performed.Three-dimensional printing technology was used to create biological experimental samples.A pull-out experiment was conducted according to a screw placement plan.Utilizing CT data and standard pedicle screw parameters,a finite element model of the L4 vertebra and a pedicle screw model(diameter 6.0 mm,length 45 mm)were established.The model was divided into five operating conditions based on screw placement angle and cycles.A finite element model was developed to simulate axial pull-out testing,analyzing stress distribution in the vertebral body and maximum axial pull-out strength of the screw.Mechanics experimental results of three-dimensional printing were compared and analyzed against simulation outcomes.RESULTS AND CONCLUSION:(1)A dedicated experimental setup for pedicle screw extraction from single vertebrae was designed and constructed.(2)In the three-dimensional printing experiment,our groups of models were compared between correctly placed screws and once improperly placed screws.The correctly placed screws group exhibited a maximum pull-out force of(1 422.63±23.80)N.Furthermore,with increasing deviation angles in screw placement,the maximum pull-out forces of each group gradually decreased.(3)Comparing the condition of a single improper nail placement with repositioning the nail correctly,when the offset angle of the improper placement exceeded that of Model 3,correctly repositioning the nail helps to increase the screw's pull-out resistance.(4)Comparing the scenario of two consecutive improper nail placements with repositioning correctly after two improper placements,correctly repositioning the nail reduced the screw's pull-out resistance.Without replacing the screw,it was not advisable to attempt a third nail placement.(5)Experimental pull-out strength of three-dimensional printing correlates significantly with finite element simulation results,with a correlation coefficient of 0.98.There is no significant difference in the outcomes between the two methods(P＞0.05).

BACKGROUND:Currently,pedicle screw fixation technology is recognized as the gold standard for lumbar posterior fusion surgery.However,this technique is associated with several complications such as suboptimal screw placement,loosening,and fracture.Addressing these issues,it requires a thorough investigation into the mechanical properties of screw reinsertion to optimize surgical procedures and enhance success rates and safety.OBJECTIVE:By combining finite element analysis with biomechanical experiments,this study aims to compare and analyze the mechanical performance of traditional trajectory pedicle screws during multiple extraction processes.The goal is to reveal patterns in screw extraction strength over repeated withdrawals,providing scientific insights into the safety and effectiveness of pedicle screw reinsertion for clinicians.METHODS:Based on CT scan data,a three-dimensional reconstruction of the L4 vertebra model was performed.Three-dimensional printing technology was used to create biological experimental samples.A pull-out experiment was conducted according to a screw placement plan.Utilizing CT data and standard pedicle screw parameters,a finite element model of the L4 vertebra and a pedicle screw model(diameter 6.0 mm,length 45 mm)were established.The model was divided into five operating conditions based on screw placement angle and cycles.A finite element model was developed to simulate axial pull-out testing,analyzing stress distribution in the vertebral body and maximum axial pull-out strength of the screw.Mechanics experimental results of three-dimensional printing were compared and analyzed against simulation outcomes.RESULTS AND CONCLUSION:(1)A dedicated experimental setup for pedicle screw extraction from single vertebrae was designed and constructed.(2)In the three-dimensional printing experiment,our groups of models were compared between correctly placed screws and once improperly placed screws.The correctly placed screws group exhibited a maximum pull-out force of(1 422.63±23.80)N.Furthermore,with increasing deviation angles in screw placement,the maximum pull-out forces of each group gradually decreased.(3)Comparing the condition of a single improper nail placement with repositioning the nail correctly,when the offset angle of the improper placement exceeded that of Model 3,correctly repositioning the nail helps to increase the screw's pull-out resistance.(4)Comparing the scenario of two consecutive improper nail placements with repositioning correctly after two improper placements,correctly repositioning the nail reduced the screw's pull-out resistance.Without replacing the screw,it was not advisable to attempt a third nail placement.(5)Experimental pull-out strength of three-dimensional printing correlates significantly with finite element simulation results,with a correlation coefficient of 0.98.There is no significant difference in the outcomes between the two methods(P＞0.05).

Objective To record and analyze the infrared spectra of rubber substrate and film in common pharmaceutical packaging materials,and to provide technical support and reference for the infrared spectra identification of rubber pharmaceutical packaging materials in the national standards system.Methods The infrared spectra of the rubber substrate and film were recorded by the Fourier transform infrared(FT-IR)-attenuated total reflection(ATR)method.The main absorption peaks in the spectra were assigned,the vibration forms were analyzed,and the influencing factors of infrared spectra were discussed.Results The infrared spectra of silicone rubber,polyisoprene rubber,halogenated butyl rubber,ethylene-tetrafluoroethylene copolymer(ETFE),tetrafluoroethylene-hexafluoropropylene copolymer(FEP)and p-xylene were analyzed.Conclusion The production formula of rubber pharmaceutical packaging materials is complex and diverse.Factors such as test methods,rubber product production formula,ATR crystal materials,and silicone oil will affect the results of infrared spectra.

Objective To observe the value of multimodal imaging for diagnosis of cardiac space-occupying lesions.Methods Data of 70 patients with cardiac space-occupying lesions who underwent echocardiography and cardiac CT(CCT)were retrospectively analyzed,among them 35 also underwent cardiac MRI(CMRI).The value of multimodal imaging for diagnosis of cardiac space-occupying lesions were explored according to the results of surgical pathology or clinical diagnosis.Results Among 70 cases,benign tumors were confirmed by surgical pathology in 43 cases,while malignant tumors were confirmed by surgical pathology in 3 cases and clinically diagnosed in 1 case.Meanwhile,non-tumor-occupying lesions were clinically diagnosed in 23 cases,all obviously shrunken after treatments.Among 70 cases,echocardiography correctly diagnosed 57 cases,misdiagnosed 8 cases and unclearly diagnosed 5 cases,with diagnostic accuracy rate of 81.43%(57/70).CCT correctly diagnosed 63 cases,misdiagnosed 4 cases but missed 3 cases,with diagnostic accuracy rate of 90.00%(63/70).CMRI outcomes in all 35 cases were consistent with surgical pathologic results,with diagnostic accuracy rate of 100%(35/35).Conclusion Multimodal imaging might provide objective evidences for diagnosis and treatment of cardiac space-occupying lesions.

OBJECTIVE: To assess the association of KIR/HLA alleles with hepatocellular carcinoma (HCC) and hepatitis B virus (HBV) infection among ethnic Han Chinese patients from southern China. METHODS: For 95 patients with HCC and 171 healthy controls, the genotype of HLA-C alleles was determined with a PCR sequence-specific oligonucleotides typing method on an Illumina GenDx NGSgo platform. Genotypes comprised of HLA-C and KIR gene alleles were also subjected to statistical analysis. RESULTS: In total 16 KIR genes (2DL2, 2DS2, 2DS3, 2DS5, 3DS1, 2DS1, 2DL5, 2DS4, 3DL1, 3DP1, 2DL3, 2DP1, 3DL3, 2DL1, 3DL2 and 2DL4) were discovered in the two groups. The frequencies of KIR2DL3 alleles and combinational genotypes of KIR2DL3/HLA-C1C2 were significantly lower in the patient group compared with the controls (0.9368 vs. 0.9883, χ²>3.84; P<0.05, OR = 0.1; 0.0112 vs. 0.2663, χ²>3.84; P<0.05, RR = 0.03). The frequency of HLA-C2C2 genotype of the patient group was significantly lower than that of the controls (0.0316 vs. 0.2690, P<0.05, RR = 0.09), while the frequency of HLA-C1C2 genotype was significantly higher than that of the controls (0.2316 vs. 0.0058, P<0.05, RR = 51.23). CONCLUSION Above results suggested that the KIR2DL3 allele is associated with lower risk for HCC. There may be individual difference in patients with HCC and HBV infection but various combinations of KIR/HLA alleles.
Alleles ; Carcinoma, Hepatocellular ; genetics ; China ; Gene Frequency ; Genotype ; Humans ; Liver Neoplasms ; genetics ; Polymorphism, Genetic ; Receptors, KIR

OBJECTIVE： To collect and summarize the pharmacoeconomic studies of adalimumab in the treatment of ankylosing spondylitis， and to explore the economics of adamumab in the treatment of ankylosing spondylitis. METHODS：Retrieved from Medline， Embase， Web of Science， VIP， CJFD and Wanfang databases， Chinese search terms included “adalimumab” “humira” “ankylosing spondylitis” “cost effectiveness” “pharmacoeconomic evaluation” “cost utility” “cost efficacy” etc. English search terms included “Adalimumab” “Humira” “Ankylosing spondylitis” “AS” “Cost effectiveness” “Pharmaceutical economic evaluation” “Pharmacoeconomics” “Cost utility” “Cost efficacy”， etc. The language is Chinese or English.The retrieval time was from January 2002 to May 2019. The pharmacoeconomic studies of adalimumab vs. traditional treatment，adalimumab vs. other biological agents in the treatment of ankylosing spondylitis were collected， including cost analysis， cost-effectiveness analysis， cost-effectiveness analysis and cost-benefit analysis.The included studies were summarized in terms of countires， research method and economic evluation results. RESULTS：Six papers were included， involving six studies. The literature was mainly distributed in the UK， Canada and the Netherlands. The Markov model was most commonly used.The incremental cost-effectiveness ratio of adalimumab in the treatment of ankylosing spondylitis was￡19 275-26 556 in UK， and adalimumab had cost-effectiveness advantage. The cost-effectiveness advantage between adalimumab and other biological agents was varied in different studies. CONCLUSIONS： Compared with conventional therapy， adalimumabhas economic advantages in the treatment of ankylosing spondylitis in UK. But there was lack of relevant research in China， which needs to be carried out urgently.

OBJECTIVETo list the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing by taking consideration of hardware, software and experimental procedures.

METHODSA total of 10 167 samples from randomly selected healthy blood donors and donor-recipient pairs from Shenzhen were typed for exons 2-4 of HLA-A, B, C, exon 2 of HLA-DRB1, and exons 2 and 3 of HLA-DQB1 by PCR- sequence-based typing. For 56 cases whose forward and reverse sequences were inconsistent, the samples were re-checked by a PCR-sequence specific oligonucleotide probe method. Novel alleles not included in the IMGT/HLA database were cloned and sequenced using in-house primers.

RESULTSEight novel HLA alleles were identified. A table for key positions of single nucleotide polymorphisms (SNPs) were generated, which summarized the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing. Among the listed SNPs, 3 were located at the HLA-A locus, 8 were at the HLA-B locus, 6 were at the C locus, 6 were at the DQB1 locus, and 4 were at the DRB1 locus. To ensure the quality control, an unique sample number for DNA transferring tubes in the process of experiment should be considered.

CONCLUSIONA protocol for quality control should be enforced by checking all of the key points. The SNPs and critical control points of the alleles should be examined to ensure the accuracy of HLA typing results.

OBJECTIVETo study the distribution of MICA alleles among ethnic Han Chinese blood donors from Shenzhen and their linkage disequilibrium with HLA-B gene.

METHODSFor 143 randomly selected blood donors, the MICA and HLA-B alleles were determined with a PCR-sequence based typing (SBT) method. Allelic frequency, haplotypic diversity and linkage disequilibrium were analyzed with a Pypop software.

RESULTSThirteen MICA and 35 HLA-B alleles were identified among the 143 blood donors, among which MICA*008:01 had the highest frequency (76/286), whilst MICA*008:01-HLA-B*40:01 and MICA*010-HLA-B*46:01 were the most common haplotypes. No novel allele was identified.

CONCLUSIONThe allele frequencies, haplotype diversities and linkage disequilibrium parameters under a high resolution can facilitate further studies and applications of the MICA and HLA-B genes.

BACKGROUND: Due to the polymorphism of HLA, a large number of ambiguities have been generated by conventional HLA typing techniques, and confirmed stereotypes of ambiguous results based on group-specific haploid full-length typing are rarely reported.OBJECTIVE: To analyze the accuracy of HLA-typing ambigulity based on group-specific haploid full-length sequencing. METHODS: The low-resolution results were used as the starting point for two ambiguous samples. Sanger sequencing (PCR-SBT) based on haploid full-length was performed after group-specific amplification. RESULTS AND CONCLUSION: One case showed a new A*02:03:01 allele, which was found a mutation in NT817 from C to T in comparison with A*11:01:01:01. The other case indicated another new C*07:02:01:01, which was found a mutation in NT879 from A to G in comparison with C*08:01:01. In conclusion, these results indicate that the group-specific haploid full-length sequencing method can be used to accurately classify HLA alleles and to discover new alleles.

OBJECTIVETo put the insight into the trichloroethylene (TCE)-induced effect on the differential expression of subcellular proteins in human normal liver cell line (L-02).

METHODSThe membrane proteins and nuclear proteins of TCE-treated (8.0 mmol/L) group and controls were extracted by subcellular proteome extraction kit, respectively. The TCE-induced differentially expressions were analyzed by a two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization tandem time-of-flight spectrometry (MALDI-TOF-MS). Bioinformatics analysis was used to reveal the biological processes and predict transmembrane domains of differential expressed proteins. The expression of ATP synthase subunit beta (ATP5B), heterogeneous nuclear ribonucleoprotein H2 (hnRNP H2) and far up steam element-binding protein 1 (FUBP1) were measured under TCE treatment by Western blot.

RESULTSAfter TCE treatment for 24 h in L-02 cells, 14 membrane proteins and 18 nuclear proteins were identified as differential expression. After treated with TCE in concentrations of 0, 2.0, 4.0 and 8.0 mmol/L for 24 h, the relative levels of ATP5B expression were 1.00±0.03, 1.21±0.14, 1.25±0.12 and 1.48±0.17 (F = 8.51, P = 0.007), the relative levels of hnRNP H2 expression were 1.00±0.09, 1.22±0.15, 1.43±0.21, 1.53±0.17 (F = 6.57, P = 0.015), respectively; the relative levels of FUBP1 expression were 1.00±0.11, 0.91±0.07, 0.73±0.04 and 0.67±0.03 (F = 15.81, P = 0.001), respectively, which were consistent with the results in proteomics. The bioinformatics analysis showed that the most dominant biological process were involved in RNA processing (10 proteins, P = 2.46×10(-6)), especially in RNA splicing (9 proteins, P = 1.77×10(-7)).

CONCLUSIONThe exposure of TCE could alter the expression of membrane proteins and nuclear proteins in L-02 cells. These abnormal expressed proteins involved in RNA splicing would provide novel clues for further understanding of TCE-induced hepatotoxicity.

Blotting, Western ; Cell Line ; DNA Helicases ; DNA-Binding Proteins ; Hepatocytes ; Heterogeneous-Nuclear Ribonucleoprotein Group F-H ; Humans ; Mitochondrial Proton-Translocating ATPases ; Proteome ; Proteomics ; RNA Processing, Post-Transcriptional ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Trichloroethylene