SARS-Cov-2-, HIV-1-, Ebola-neutralizing and anti-PD1 clones are predisposed

Antibody repertoire refers to the totality of the superbly diversified antibodies within an individual to cope with the vast array of possible pathogens. Despite this extreme diversity, antibodies of the same clonotype, namely public clones, have been discovered among individuals. Although some public clones could be explained by antibody convergence, public clones in naive repertoire or virus-neutralizing clones from not infected people were also discovered. All these findings indicated that public clones might not occur by random and they might exert essential functions. However, the frequencies and functions of public clones in a population have never been studied. Here, we integrated 2,449 Rep-seq datasets from 767 donors and discovered 5.07 million public clones - ~10% of the repertoire are public in population. We found 38 therapeutic clones out of 3,390 annotated public clones including anti-PD1 clones in healthy people. Moreover, we also revealed clones neutralizing SARS-CoV-2, Ebola, and HIV-1 viruses in healthy individuals. Our result demonstrated that these clones are predisposed in the human antibody repertoire and may exert critical functions during particular immunological stimuli and consequently benefit the donors. We also implemented RAPID - a Rep-seq Analysis Platform with Integrated Databases, which may serve as a useful tool for others in the field.

Early transplantation of growth differentiation factor 11-silenced bone marrow stromal cells promotes osteogenesis in necrotic femoral head induced by steroid in rats / 中华创伤骨科杂志

Objective@#To study the effect of growth differentiation factor (GDF) 11-silenced bone marrow stromal cells (BMSCs) on bone regeneration in early steroid-induced osteonecrosis of the femoral head in rats.@*Methods@#After GDF11 expression in BMSCs was inhibited by siRNA, the knockdown efficiency and transfection cytotoxicity were detected. The further experiments both in vitro (n=3) and in vivo (n=8) were divided into 4 groups respectively: blank control group (without any intervention), model group (glucocorticoid treatment), experimental group (siRNA transfection and glucocorticoid treatment) and negative control group (negative control transfection and glucocorticoid treatment). The BMSCs were induced into osteogenic differentiation. Alkaline phosphatase (ALP) staining and alizarin red staining were applied to evaluate the osteogenic differentiation ability of the cells while reverse transcription polymerase chain reaction (qRT-PCR) was employed to detect the relative expression levels of osteogenic markers. The osteogenesis in the necrotic femoral head was evaluated by microCT, H&E staining, immunohistochemistry staining and biomechanical test.@*Results@#No transfection cytotoxicity was found (P>0.05). The ALP staining and alizarin red staining showed that the osteogenic differentiation of BMSCs in the experimental group was better than that in the model group. At the level of mRNA, the relative expression of ALP, runt-related transcription factor (Runx) 2, osteocalcin (OCN) and type Ⅰ collagen (α1) (COL1A1) in the blank control group (1.00±0.09, 1.02±0.23, 1.03±0.30 and 1.02±0.25, respectively) were significantly higher than those in the model group (0.46±0.11, 0.50±0.11, 0.35±0.01 and 0.57±0.02, respectively) but significantly lower than those in the experimental group (1.97±0.30, 0.94±0.19, 1.50±0.18 and 1.28±0.37) (all P<0.05). MicroCT images and quantitative analysis showed that the bone mass in the experimental group was significantly increased compared with the model group (P<0.05). Histological examination showed better bone regeneration and higher expression of Runx2 and COL1 in the necrotic femoral head in the experimental group than in the model group. Improved biomechanical properties were shown in the experimental group compared with the model group (P<0.05).@*Conclusions@#Silence of GDF11 expression may alleviate the inhibitory effect of glucocorticoid on osteogenic differentiation of BMSCs. Early transplantation of GDF11-silenced BMSCs may promote osteogenesis in the necrotic femoral head in rats.

Early transplantation of growth differentiation factor 11-silenced bone marrow stromal cells promotes osteogenesis in necrotic femoral head induced by steroid in rats / 中华创伤骨科杂志

Objective To study the effect of growth differentiation factor (GDF) 11-silenced bone marrow stromal cells (BMSCs) on bone regeneration in early steroid-induced osteonecrosis of the femoral head in rats.Methods After GDF11 expression in BMSCs was inhibited by siRNA,the knockdown efficiency and transfection cytotoxicity were detected.The further experiments both in vitro (n =3) and in vivo (n =8)were divided into 4 groups respectively:blank control group (without any intervention),model group (glucocorticoid treatment),experimental group (siRNA transfection and glucocorticoid treatment) and negative control group (negative control transfection and glucocorticoid treatment).The BMSCs were induced into osteogenic differentiation.Alkaline phosphatase (ALP) staining and alizarin red staining were applied to evaluate the osteogenic differentiation ability of the cells while reverse transcription polymerase chain reaction (qRT-PCR) was employed to detect the relative expression levels of osteogenic markers.The osteogenesis in the necrotic femoral head was evaluated by microCT,H& E staining,immunohistochemistry staining and biomechanical test.Results No transfection cytotoxicity was found (P ＞ 0.05).The ALP staining and alizarin red staining showed that the osteogenic differentiation of BMSCs in the experimental group was better than that in the model group.At the level of mRNA,the relative expression of ALP,runt-related transcription factor (Runx) 2,osteocalcin (OCN) and type Ⅰ collagen (α1) (COL1A1) in the blank control group (1.00 ± 0.09,1.02 ± 0.23,1.03 ± 0.30 and 1.02 ± 0.25,respectively) were significantly higher than those in the model group (0.46±0.11,0.50±0.11,0.35±0.01 and0.57±0.02,respectively) but significantly lower than those in the experimental group (1.97±0.30,0.94±0.19,1.50±0.18 and 1.28 ±0.37) (all P ＜ 0.05).MicroCT images and quantitative analysis showed that the bone mass in the experimental group was significantly increased compared with the model group (P ＜ 0.05).Histological examination showed better bone regeneration and higher expression of Runx2 and COL1 in the necrotic femoral head in the experimental group than in the model group.Improved biomechanical properties were shown in the experimental group compared with the model group (P ＜ 0.05).Conclusions Silence of GDF11 expression may alleviate the inhibitory effect of glucocorticoid on osteogenic differentiation of BMSCs.Early transplantation of GDF11-silenced BMSCs may promote osteogenesis in the necrotic femoral head in rats.

Digital navigation enhances cervical pedicle screw placement accuracy and safety:study protocol of a randomized controlled trial / 中国组织工程研究

BACKGROUND:A unified standard for cervical pedicle screw placement does not currently exist;therefore, it is difficult to quantitatively evaluate the clinical effects of the technique. Digital navigation can provide a reference for accurate and safe location, orientation, and placement of cervical pedicle screws. OBJECTIVE:To investigate whether digital navigation can greatly increase the accuracy and safety of cervical pedicle screw placement. METHODS:This was a prospective, single-center, randomized control ed, open-label trial. Seventy-six patients with cervical spine fracture scheduled to receive treatment in the Department of Orthopedics, Affiliated Hospital of Nantong University, China were randomly divided into three groups to undergo cervical pedicle screw internal fixation. Patients in the cervical lamina partial excision group (n=26, 160 screws) underwent partial cervical lamina excision and cervical pedicle screw internal fixation;those in the pipeline-dredge discharge group (n=27, 156 screws) underwent pipeline-dredge discharge and cervical pedicle screw internal fixation;and those in the digital navigation group (n=23, 162 screws) underwent digital navigation-assisted cervical pedicle placement. Al patients were evaluated at 12 and 36 months. The primary outcome was the percentage of screws graded I when evaluating the penetration degree of the cervical pedicle screws, which evaluates the accuracy of screw placement, 12 months after internal fixation. Secondary outcomes included:(1) the percentage of screws graded I when evaluating the penetration degree of cervical pedicle screws 36 months after internal fixation;(2) bony fusion rate of the atlantoaxial joint, used to evaluate fracture healing, 12 and 36 months after internal fixation;(3) Visual Analogue Scale spine score, used to evaluate cervical neck pain, prior to and 12 and 36 months after internal fixation;(4) American Spinal Injury Association Classification, used to evaluate improvement in neurological function, prior to and 12 and 36 months after internal fixation;and (5) adverse events, used to evaluate the safety of each pedicle screw implantation method, 12 and 36 months after internal fixation. This trial protocol was approved by Medical Ethics Committee, Affiliated Hospital of Nantong University, China, and was performed in accordance with the guidelines of the Declaration of Helsinki, formulated by the World Medical Association. Signed informed consent regarding trial procedure and treatment was obtained from each patient. DISCUSSION:This trial protocol compared the effects of three cervical pedicle screw internal fixation methods for the treatment of cervical spine fracture, and investigated and compared the accuracy and safety of digital navigation-assisted cervical pedicle screw placement with partial cervical lamina excision and pipeline-dredge discharge. We hoped to provide quantitative evidence for the clinical use of digital navigation in orthopedics, especial y in cervical pedicle screw placement. TRIAL REGISTRATION:This trial was registered at ClinicalTrials.gov identifier:NCT02880839 on 19 August 2016.

Surgery for severe thoracolumbar fracture dislocation via a posterior approach.

Between June 2008 and June 2013, our department treated 16 severe thoracolumbar fracture dislocations (13 male and three female patients; mean age 33.6 years) with a pedicle screw system via an entirely posterior approach. We followed all patients for 18-69 months (mean 35 months). The mean operation time was 170 minutes (range: 120-280), and mean blood loss was 700 ml (range: 450-1300). The percentage displacement (mean ± standard deviation) improved from a preoperative value of 72 ± 20% to 10 ± 6% postoperatively, and the deformity angle (mean ± standard deviation) improved from 29.2 ± 15.0° to 12.6 ± 6.7°. Of the six patients with American Spinal Injury Association Grade A, one improved to Grade B, one to Grade C and four had little improvement. Of the five patients with Grade B, three improved to Grade C and two to Grade D. Of the four Grade C patients, two improved to Grade D, and the other two to Grade E. One Grade D patient improved to Grade E. No loosening or breakage of the internal implants occurred in the follow-up period. Therefore, we conclude that although it is difficult, the posterior approach alone is safe and biomechanically reliable for treating severe thoracolumbar fracture dislocations. The maintenance of deformity correction and stable local mechanical reconstruction in the follow-up period support this single approach strategy.

Whole blood allele-specific PCR, a simple method to detect four ATP7B gene mutations in Wilson disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a simple method to detect four ATP7B gene mutations in Wilson disease using allele-specific PCR(AS-PCR) with whole blood polymerase chain reaction.</p><p><b>METHODS</b>Four allele-specific PCR primers specific for the mutations(G2333T, C2850T, G2855A, G2975T) were designed, and PCR was optimized to screen the whole blood samples. The amplified gene products with mutation were separated with agarose gel electrophoresis to detect the pattern of point mutation and allele types. Exons 8, 12 and 13 of the ATP7B gene were amplified with PCR, and the amplification products were sequenced to confirm the mutation.</p><p><b>RESULTS</b>The detection of four ATP7B gene mutations by AS-PCR with whole blood was accomplished with 100% accuracy. In the 27 healthy subjects, the mutation rate of G2855A was 51.8%. No mutation was detected for G2333T, C2850T and G2975T. Among the 22 patients, 11 were mutated for G2333T, C2850T or G2975T. The mutation rate was therefore 50%.</p><p><b>CONCLUSION</b>Our experiment has established an AS-PCR based method for detecting four ATP7B gene mutations using whole blood samples, which has provided a simple and effective means for the early diagnosis of Wilson disease. This method is rapid, convenient, accurate and economical for detecting point mutations of the ATP7B gene.</p>