To evaluate the disk position of the temporomandibular joint using calcium suppressed spectral-based CT images in the patients with temporomandibular disorder / 中华口腔医学杂志

Objective@#To evaluate the application of calcium suppressed (CaSupp) spectral CT technique in evaluating disk position and measuring the thickness of the posterior band of temporomandibular joint (TMJ).@*Methods@#The twenty-three temporomandibular disorder patients [mean age 23(12~62) years, male/female=14/9] were performed with oblique sagittal and coronal proton density weighted imaging (PDWI) and spectral CT scans from February to July, 2019 in Department of Radiology, Hainan Hospital of General Hospital of Chinese PLA, and 45 TMJ joints were evaluated. The subjects were classified into two groups according to the scanning modalities: MRI measurement group and CaSupp spectral-based CT group. The CaSupp technique were applied with the spectral-based CT images and CaSupp images were generated. The oblique sagittal and coronal CaSupp imaged were reformatted by perpendicular to the long axis of the condyle. The TMJ disk positions were evaluated on oblique sagittal and coronal images, and the maximal disk thickness were measured on the oblique sagittal images.@*Results@#The joint position was basically consistent on MRI and CaSupp images for the 45 TMJ joints. The intra-class coefficient value was 0.843 (0.712, 0.914) for the measurement of the posterior band of the TMJ disk between MRI and CaSupp images. Bland-Altman presented that the [95.6% (43/45)] points with the difference located in the 95% agreement interval. Wilcoxon paired text demonstrated that there was no significant different for the thickness of the posterior band between MRI [2.57 (1.76, 3.65) mm] and CaSupp images [2.67 (1.74, 4.56) mm] (P=0.07).@*Conclusions@#The CaSupp spectral-based CT could be used to evaluated the TMJ disk position and the thickness of the posterior band.

Reproducibility analysis of quantitative susceptibility mapping of cerebral subcortical nuclei in healthy adults / 南方医科大学学报

OBJECTIVE@#To investigate the intra- and inter-scanner reproducibility of quantitative susceptibility mapping (QSM) of cerebral subcortical nuclei in healthy adults.@*METHODS@#QSM was performed in 21 healthy adults on two different 3.0T MR scanners, and the region of interest (ROI) method was used to measure the magnetic susceptibility value of the left subcortical nuclei (the head of the caudate, putamen, globus pallidus, thalamus, substantia nigra and red nucleus). The intraclass correlation coefficient (ICC) and Bland-Altman method were used to evaluate the inter-scanner and intra-scanner reliability.@*RESULTS@#The ICCs of the susceptibility value ranged from 0.90 to 0.99 for all the subcortical gray nuclei except for the head of the caudate nucleus measured on the same MR scanner by the same observer. Bland-Altman analysis revealed that the points with susceptibility differences for all the subcortical gray nuclei except for substantia nigra located in the 95% CI of limits of agreement for the same MR scanner. The ICCs of the susceptibility value for the inter-scanner was 0.49 (0.08-0.75) for the head of the caudate nuleus, 0.80 (0.57-0.91) for the putamen, 0.77 (0.51-0.90) for the globus pallidus, 0.78 (0.54-0.91) for the thalamus, 0.80 (0.56-0.91) for the substantia nigra and 0.93 (0.83-0.97) for the red nucleus. The points with susceptibility difference (95.2%, 20/21) located in the 95% CI of limits of agreement for the putamen and the thalamus measured on two different MR scanners.@*CONCLUSIONS@#The intra-scanner reproducibility of QSM of the subcortical gray nuclei is superior to the inter-scanner reproducibility in healthy adults.

Application of ELISA in Detecting Heparin-Induced Thrombocytopenia Antibodies / 现代检验医学杂志

Objective To develop an ELISA method for determination of heparin-induced thrombocytopenia (HIT)antibody. Methods The compound formed between human platelet factor 4 (PF4)and heparin was used as the coating antigen,incu-bating the patients plasma with the coating antigen in the well,after washing,the second antibody labeled HRP was added in the well to incubate and washing again,the chromogenic substrates was added in the well to incubate,when the stop reaction was finished,the absorbance A450/A630 was detected,and the test results were judged according to standard,this method was compared with IBL method and was optimized and evaluated the performance.Results An indirect ELISA method was de-velop with the purified human PF4,the optimal dilution of sample and second antibody were 1∶100 and 1∶1 500 which de-tected by the orthogonal test,the intra-and inter-assay average coefficients of variation were 7.66% and 7.76%(<10%) respectively that detected by repeated measurement the three positive standard plasma.Through measureing the 100 healthy human plasm with no history of using heparin,the positive and negative predictive reference values were 0.304 and 0.456. IBL and this method detected 100 hemodialysis patients samples at the same time,and the result of statistical analysis was that,the sensitivity,speciality and accuracy of this method were 90%,97.78% and 90%,respectively.The negative and posi-tive predictive value were 81.8% and 98.88% respectively,and the difference was statistically significant [K=0.84(0.81~1)and Pexac=0.012<0.05].The difference was statistically significant,consistency was optimal,95% confidence interval was 92.59%~92.59%.Conclusion Comparing with the IBL,the method reported by this article had the similar perform-ance and good consistency,and it could satisfy the clinical detection and diagnosis of HIT patients.

Novel qPCR strategy for quantification of recombinant adeno-associated virus serotype 2 vector genome-titer / 生物工程学报

Adeno-associated virus (AAV) has many advantages for gene therapy over other vector systems. However, after the production of recombinant AAV (Raav) vectors, the biological titration of rAAV stocks is still cumbersome. Different investigators used laboratory-specific methods or internal reference standards that may limit preclinical and clinical applications. The inverted terminal repeats (ITR) sequences are the only cis-regulated viral elements required for rAAV packaging and remain within viral vector genomes. ITR is the excellent target sequences for qPCR quantification of rAAV titer. In this study, we developed a novel qPCR strategy to quantify rAAVs' vector genome titer via targeting the ITR2 or ITR2-CMV element. In conclusion, the method is fast and accurate for the titration of rAAV2-derived vector genomes. It will promote the standardization of rAAV titration in the future.

Study on the relationships of the width of periodontal ligaments and the capacity ratio of collagen fibers with the elastic modulus of fresh bovine periodontal ligaments / 生物医学工程学杂志

This experiment was aimed to shed light on the correlation and quantitative relationships between the width of bovine periodontal ligament (PDL) and the elastic modulus and, more over, between the width of bovine PDL and the capacity ratio of collagen fibers. The width and length of periodontal ligament of PDL were determined by stereomicroscope, and the elastic modulus by the materials testing systems. The collagen fibers in cross section of the specimen were stained with 1% Sirius Red F3B in saturated carbazotic acid, and the photo of stained PDL was collected by stereomicroscope. Image pro plus6.0 image analysis software was used to measure and calculate the capacity ratio of collagen fibers. It was found that there is a negative correlation between the width of bovine periodontal ligament and elastic modulus. The correlation coefficient is -0.21 and the simple linear regression model is Y = 71. 681-0.021x (Width of PDL); there is a positive correlation between capacity ratio of collagen fibers and elastic modulus. The coefficient correlation is 1.583 and the simple linear regression model is Y = -34.944 + 1.583x (The percentage of collagen fibers). Thus, the elastic modulus of bovine PDL increases while the width of bovine PDL decreases, and it increases while the capacity ratio of collagen fibers increases.