[Effect and mechanism of human adipose-derived stem cell exosomes on diabetic peripheral neuropathy]

Objective: To investigate the changes of artemin protein expression in diabetic peripheral neuropathy (DPN) and to explore the regulatory effect of human adipose-derived stem cell (ADSC) exosomes on the change of artemin protein expression. Methods: This research was a prospective observational clinical research combined with experimental research. Thirteen DPN patients (9 males and 4 females, aged 32 to 68 years) who were admitted to the First Affiliated Hospital of Air Force Medical University (hereinafter referred to as our hospital) from May 2022 to October 2023 and met the inclusion criteria were selected as DPN group, and 5 non-diabetes patients (4 males and 1 female, aged 29 to 61 years) who were admitted to our hospital in the same period of time and met the inclusion criteria were selected as control group. The toe nerve or sural nerve tissue in the abandoned tissue after debridement or amputation of patients in the two groups was collected. The pathological changes of nerve tissue were observed after hematoxylin-eosin staining; the protein expressions of S100β and artemin in nerve tissue were observed after immunofluorescence staining, and the artemin protein expression was quantified; the protein and mRNA expressions of artemin were detected by Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction, respectively (the sample number in DPN group and control group was 13 and 5, respectively). Twelve male C57BL/6 mice aged 3 to 5 days were collected to isolate Schwann cells, and the cells were divided into conventional culture group cultured routinely, high glucose alone group (cultured with high concentration of glucose solution only), and high glucose+exosome group (cultured with high concentration of glucose solution and extracted human ADSC exosomes). After 24 hours of culture, the cell proliferation activity was detected by cell counting kit 8 (n=6). After 48 hours of culture, the protein expression of artemin was detected by Western blotting (n=3). Results: Compared with those in control group, the neural supporting cells decreased and the inflammatory cells increased in the nerve tissue of patients in DPN group, showing typical manifestations of nerve injury. Immunofluorescence staining showed that compared with those in control group, the nuclei was more, and the protein expression of S100β was lower in nerve tissue of patients in DPN group. The protein expression of artemin in nerve tissue of patients in DPN group was 71±31, which was significantly lower than 1 729±62 in control group (t=76.92, P<0.05). Western blotting detection showed that the protein expression of artemin in nerve tissue of patients in DPN group was 0.74±0.08, which was significantly lower than 0.97±0.06 in control group (t=5.49, P<0.05). The artemin mRNA expression in nerve tissue of patients in DPN group was significantly lower than that in control group (t=7.65, P<0.05). After 24 hours of culture, compared with that in conventional culture group, the proliferation activities of Schwann cells in high glucose alone group and high glucose+exosome group were significantly decreased (P<0.05); compared with that in high glucose alone group, the proliferation activity of Schwann cells in high glucose+exosome group was significantly increased (P<0.05). After 48 hours of culture, compared with those in conventional culture group, the protein expressions of artemin of Schwann cells in high glucose alone group and high glucose+exosome group were significantly decreased (P<0.05); compared with that in high glucose alone group, the protein expression of artemin of Schwann cells in high glucose+exosome group was significantly increased (P<0.05). Conclusions: The protein expression of artemin in nerve tissue of DPN patients is lower than that in normal nerve tissue, which may be related to the reduction of proliferation activity of Schwann cells by high glucose. Human ADSC exosomes may improve the proliferation activity of Schwann cells by increasing artemin protein expression, thereby delaying the progression of DPN.

[Research advances on the role of Schwann cells in diabetic peripheral neuropathy]

Diabetic peripheral neuropathy (DPN) is one of the common chronic complications of diabetes, resulting in neuropathy of spinal nerve, cranial nerve, and vegetative nerve. Diabetic distal symmetric multiple neuropathy is the most representative lesion of DPN, including symptoms of bilateral limbs pain, numbness, and paresthesia, etc. DPN is one of the main reasons causing diabetic foot ulcer (DFU). Schwann cells (SCs) are the primary glia cells of the peripheral nervous system, which play very important role in repairing after nerve injury. As the target cells of chronic hyperglycemia, SCs' functions, including the formation of myelin sheath, the secretion of neurotrophic factors, energy supplying for the axon, and the guidance of axon regeneration, etc., are damaged under the action of high glucose. The destroyed functions of SCs can inhibit the repair of damaged nerves and accelerate the progress of DPN. Therefore, if the damage of high glucose to SCs can be effectively reduced, it will provide a new way for the treatment of DPN and DFU and reduce the morbidity of DFU. This review focuses on the function of SCs and its relationship with DPN.

[Sequence analysis of Paragonimus internal transcribed spacer 2 and cyclooxygenase 1 genes in freshwater crabs in Henan Province]

OBJECTIVE

To investigate the sequences of internal transcribed spacer 2 (ITS2) and cyclooxygenase 1 (COX1) genes of Paragonimus metacercariae in freshwater crabs in Henan Province, identify the species of Paragonimus and evaluate its genetic relationships with Paragonimus isolates from other provinces in China.

METHODS

Freshwater crabs were collected from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province from 2016 to 2021, and Paragonimus metacercariae were detected in freshwater crabs. Genomic DNA was extracted from Paragonimus metacercariae, and the ITS2 and COX1 genes were amplified using PCR assay, followed by sequencing of PCR amplification products. The gene sequences were spliced and aligned using the software DNASTAR, and aligned with the sequences of Paragonimus genes in the GenBank. Phylogenetic trees were created using the MEGA6 software with the Neighbor-Joining method based on ITS2 and COX1 gene sequences, with Fasciola hepatica as the outgroup.

RESULTS

The detection rates of Paragonimus metacercariae were 6.83% (11/161), 50.82% (31/61), 18.52% (5/26), 8.76% (12/137), 14.29% (9/63), 17.76% (19/105), 18.50% (32/173) and 42.71% (41/96) in freshwater crabs from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province, with a mean detection rate of 19.46% (160/822), and a mean infection intensity of 0.57 metacercariae/g. The amplified ITS2 and COX1 gene fragments of Paragonimus were approximately 500 bp and 450 bp in lengths, respectively. The ITS2 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (99.8% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: MW960209.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with P. skrjabini from Sichuan Province (GenBank accession number: AY618747.1), Guangxi Zhuang Autonomous Region (GenBank accession number: AY618729.1) and Hubei Province (GenBank accession number: AY618751.1), and P. miyazaki from Fujian Province (GenBank accession number: AY618741.1) and Japan (GenBank accession number: AB713405.1). The COX1 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (90.0% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: AY618798.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with all P. skrjabini and clustered into the same sub-clade with P. skrjabini from Hubei Province (GenBank accession numbers: AY618782.1 and AY618764.1).

CONCLUSIONS

Paragonimus species from freshwater crabs in Henan Province were all characterized as P. skrjabini, and the ITS2 and COX1 gene sequences had the highest homology to those of P. skrjabini from Hubei Province. The results provide insights into study of Paragonimus in Henan Province and China.

Virus-like Particle Vaccines of Infectious Bursal Disease Virus Expressed in Escherichia coli Are Highly Immunogenic and Protect against Virulent Strain

OBJECTIVES

Infectious bursal disease virus (IBDV) is a highly contagious, acutely infectious agent that causes immunosuppression in chickens. We expressed IBDV VP2 proteins in Escherichia coli (E. coli) to develop an effective virus-like-particles (VLPs) vaccine and evaluated its immunogenicity.

METHODS

The VLPs produced in E. coli were used as an immunogen mixed with a water-in-mineral-oil adjuvant (MontanideTM ISA 71 VG, ISA 71 RVG) or a white oil (7#) adjuvant. VLPs without an adjuvant, commercial subunit vaccine, inactivated vaccine, and attenuated vaccine were used as controls. These test vaccines were intramuscularly injected into 19-day-old SPF chickens, which were challenged with the IBDV virulent strain at 30 days after vaccination.

RESULTS

The adjuvants boosted antibody production, and the adjuvant groups (except white oil) produced higher antibody levels than the non-adjuvanted controls and the commercial vaccine groups. In terms of cellular immunity, the VLPs plus adjuvant combinations produced higher levels of cytokines, IL-2, IL-4, and IFN-γ than the controls.

CONCLUSION

IBDV VLPs plus the ISA 71 RVG adjuvant can be used as an optimal vaccine combination for improving the immune efficacy of IBD subunit vaccines, which can protect against the virulent strain.

[Effects of the anterolateral thigh chimeric perforator flaps in repairing complex wounds of foot and ankle]

Objective: To investigate the effects of anterolateral thigh chimeric perforator flap in repairing complex wounds of foot and ankle. Methods: A retrospective observational study was conducted. From May 2018 to June 2022, 23 patients who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University to repair complex wounds of foot and ankle with anterolateral thigh chimeric perforator flaps, including 15 males and 8 females, aged from 20 to 66 years. The wounds were all accompanied by bone exposure and defects, and were complicated with varying degrees of infection. All patients underwent debridement and continuous vacuum sealing drainage treatment for 1 week in stage Ⅰ, with the skin and soft tissue defect area after debridement being 10 cm×5 cm to 22 cm×7 cm. In stage Ⅱ, the anterolateral thigh chimeric perforator flap was used to cover the defective wound, of which the muscle flap was used to fill the deep invalid cavity of the ankle joint or cover bone and internal fixation exposures, and the skin flap was used to cover the superficial wound, with the area of the skin flap ranging from 11 cm×6 cm to 23 cm×8 cm, and the area of the muscle flap ranging from 4.0 cm×2.5 cm to 8.0 cm×5.0 cm. The survival of the flap was observed after operation. During follow-up, the color, texture, appearance, and complications of the flap were observed, the function of ankle joint and its range of dorsiflexion motion and plantar flexion motion were measured, and the scar hyperplasia and muscular hernia in donor area were observed. Results: Ecchymosis and epidermal necrosis occurred at the tip of the flap in 1 patient on 5 days after operation and healed after dressing change for 1 week; the other flaps of patients survived successfully. After 6 to 40 months of follow-up, the color, texture, and shape of flaps were good, but 1 patient was not satisfied with the shape of the flap because of flap swelling; the ankle joint movement was basically normal, the dorsiflexion motion was 15-30°, and the plantar flexion motion was 20-45°; the scar hyperplasia in the donor area of the flap was not obvious, and no muscular hernia occurred. Conclusions: The anterolateral thigh chimeric perforator flap can effectively fill the deep invalid cavity of ankle joint and cover the superficial wound at the same time, with minimal damage to the donor site. So it is an ideal flap for repairing the complex wounds of foot and ankle.

A novel bivalent anti-c-MET/PD-1 bispecific antibody exhibits potent cytotoxicity against c-MET/PD-L1-positive colorectal cancer

Previously, we generated a novel bispecific antibody (BsAb) simultaneously targeting both c-MET and PD-1 (PDCD1), which can bridge T cells and c-MET positive tumor cells. However, the specific mechanisms and antitumor activities of the BsAb against c-MET/PD-L1 (CD274) positive colorectal cancer (CRC) is not completely understood. In this study, in addition to the tumor intrinsic mechanism investigation with molecular biology assay in vitro, a humanized mouse model was used to evaluate antitumor activity of the BsAb in vivo. The BsAb could inhibit c-MET/PD-L1+ CRC cell migration and show strong antitumor activity against HCT116 tumors in mice, potentially by inducing the degradation of c-MET protein in a dose and time-dependent manner. The BsAb could suppress the phosphorylation of c-MET downstream proteins GRB2-associated-binding protein 1 (Gab1) and focal adhesion kinase (FAK). Considering the tumor extrinsic mechanism, the BsAb may promote phagocytosis of macrophage. Furthermore, the level of plasma exosomal-c-MET/PD-L1 is able to distinguish CRC patients from healthy controls. In summary, the BsAb exhibited potent anti-tumor activities by two distinguished mechanisms: inhibition of c-MET signal transduction and promotion of macrophage-mediated phagocytosis. Our BsAb may provide a novel therapeutic agent for patients with c-MET/PD-L1+ CRC, and the status of exosomal-c-MET/PD-L1 can serve as a biomarker to predict responsiveness to treatment of our BsAb.

Identification of a Linear B Cell Epitope on p54 of African Swine Fever Virus Using Nanobodies as a Novel Tool

African swine fever (ASF) has received great attention from the swine industry due to the pandemic and the lack of vaccines or effective treatments. In the present study, 13 African swine fever virus (ASFV) p54-specific nanobodies (Nbs) were successfully screened based on Bactrian camel immunization of p54 protein and phage display technology, and their reactivity with the p54 C-terminal domain (p54-CTD) was determined; however, only Nb8-horseradish peroxidase (Nb8-HRP) exhibited the best reactivity. Immunoperoxidase monolayer assay (IPMA) and immunofluorescence assay (IFA) results indicated that Nb8-HRP specifically reacted with ASFV-infected cells. Then, the possible epitopes of p54 were identified using Nb8-HRP. The results showed that Nb8-HRP could recognize p54-CTD truncated mutant p54-T1. Then, 6 overlapping peptides covering p54-T1 were synthesized to determine the possible epitopes. Dot blot and peptide-based enzyme-linked immunosorbent assay (ELISA) results suggested that one novel minimal linear B cell epitope, 76QQWVEV81, which had never been reported before, was identified. Alanine-scanning mutagenesis revealed that 76QQWV79 was the core binding site for Nb8. Epitope 76QQWVEV81 was highly conserved among genotype II ASFV strains and could react with inactivated ASFV antibody-positive serum from naturally infected pigs, indicating that it was a natural linear B cell epitope. These findings provide valuable insights for vaccine design and p54 as an effective diagnostic tool. IMPORTANCE The ASFV p54 protein plays an important role in inducing neutralization antibodies in vivo after viral infection and is often used as a candidate protein for subunit vaccine development. The full understanding of the p54 protein epitope provides a sufficient theoretical basis for p54 as a vaccine candidate protein. The present study uses a p54-specific nanobody as a probe to identify a highly conserved antigenic epitope, 76QQWVEV81, among different ASFV strains, and it can induce humoral immune responses in pigs. This is the first report using virus-specific nanobodies as a tool to identify some special epitopes that cannot be recognized by conventional monoclonal antibodies. This study opens up nanobodies as a new tool for identifying epitopes and also provides a theoretical basis for understanding p54-induced neutralizing antibodies.

Bacteria-targeted delivery of black phosphorus quantum dots facilitates photothermal therapy against hypoxic tumors and complementary low-dose radiotherapy

Many approaches have been employed to relieve hypoxia in solid tumors to enhance sensitivity to radiotherapy (RT), including O₂ delivery or hydrogen peroxide (H₂O₂) decomposition strategies. To date, however, these modalities have been restricted by poor O₂ loading, rapid O₂ leakage, and limited endogenous H₂O₂ levels. To overcome these limitations, we therefore sought to develop an effective approach for the oxygen-independent treatment of hypoxic tumors. In this study, we designed a novel black phosphorus quantum dot (BPQD)/Escherichia coli (E. coli) hybrid system (BE) capable of facilitating the photothermal therapy (PTT) of hypoxic tumors. A simple electrostatic adsorption approach was used to conjugate BPQDs to E. coli. BE is capable of reliably targeting hypoxic tumors and mediating PTT. BPQDs in BE can directly facilitate X-ray-mediated radiosensitization of tumors, thereby achieving significant RT efficacy in response to lower doses of radiation, effectively and specifically damaging hypoxic tumor tissues to suppress the growth of tumors. Our results highlight this BE system as a novel approach to tumor radiosensitization with great potential for clinical application.

[A prospective randomized controlled study of antibiotic bone cement in the treatment of diabetic foot ulcer]

Objective: To investigate the clinical effects and related mechanism of antibiotic bone cement in treating diabetic foot ulcer (DFU). Methods: A prospective randomized controlled study was conducted. From August 2020 to August 2022, 24 patients with DFU who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University. According to the block randomization, the patients were divided into 2 groups, with 12 patients in each group. In antibiotic bone cement group, there were 7 male and 5 female patients, aged (64±8) years, with the ulcer area of (41±21) cm2. In silver sulfadiazine group, there were 8 male and 4 female patients, aged (62±8) years, with the ulcer area of (38±19) cm2. Under the condition of ensuring the patency of at least one main inferior genicular artery in each patient, the continuous vacuum sealing drainage was performed for 3-5 days after thorough debridement. Thereafter, the wounds in antibiotic bone cement group were treated with gentamicin-laden bone cement, and the wounds in silver sulfadiazine group were treated with silver sulfadiazine cream for dressing change. After 3 weeks of dressing change, the wound was covered with split-thickness skin graft from the lateral thigh on the affected side. Before debridement and after 3 weeks of dressing change, the blood flow intensities of wound tissue and normal skin tissue in foot were measured using laser Doppler flowmeter, and then, the percentage of relative blood flow intensity of wound and the change rate of blood flow intensity were calculated. After 3 weeks of dressing change, the wound margin tissue was taken, the number of CD31-positive neovascular and the vascular morphology were observed and detected by immunohistochemical staining, the morphology of blood vessels surrounded by CD31 and α-smooth muscle actin (α-SMA) double-positive cells was observed by immunofluorescence staining, the cell proliferation activity was evaluated by immunofluorescence staining (denoted as the ratio of Ki67 positive cells), and the protein expression of vascular endothelial growth factor receptor 2 (VEGFR2) was detected by Western blotting. The skin graft survival was observed 3-5 days after skin grafting, and the wound healing time was recorded. Data were statistically analyzed with independent sample t test and Fisher's exact probability test. Results: The percentages of relative blood flow intensity of wounds of patients before debridement were similar between the two groups (P>0.05). After 3 weeks of dressing change, the percentage of relative blood flow intensity of wounds and the change rate of blood flow intensity of patients in antibiotic bone cement group were (44.7±2.0)% and (129±12)%, respectively, which were significantly higher than (28.3±1.2)% and (41±8)% in silver sulfadiazine group (with t values of 24.15 and 20.97, respectively, P<0.05). After 3 weeks of dressing change, compared with those in silver sulfadiazine group, the number of CD31-positive neovascular in the wound margin tissue of patients in antibiotic bone cement group was significantly increased (t=33.81, P<0.05) with larger diameter and more regular arrangement, the vascular wall continuity surrounded by CD31 and α-SMA double-positive cells was better, and the ratio of Ki67 positive cells and protein expression of VEGFR2 were significantly increased (with t values of 40.97 and 47.38, respectively, P<0.05). On post skin grafting day 3-5, all the patients in antibiotic bone cement group and 8 patients in silver sulfadiazine group had good skin graft survival, while 4 patients in silver sulfadiazine group showed spotted/patchy skin graft necrosis, which were cured after corresponding treatment. The wound healing time of patients in antibiotic bone cement group was (47.1±2.9) d, which was significantly shorter than (58.8±2.3) d in silver sulfadiazine group (t=10.86, P<0.05). Conclusions: Compared with silver sulfadiazine, clinical application of antibiotic bone cement for treating DFU has the characteristics of accelerating wound healing and better reconstruction of local blood flow, which may be closely related to the fact that antibiotic bone cement promoted the local angiogenesis effectively in the wound through enhancing the expression of VEGFR2.

Identification of a linear B-cell epitope on the African swine fever virus CD2v protein

African swine fever virus (ASFV) poses a serious threat to domestic pigs and wild boars, which is responsible for substantial production and economic losses. A dominant ASFV specific linear B cell epitope that reacted with the convalescent serum was explored and identified with the help of immune informatics techniques. It is essential in understanding the host immunity and in developing diagnostic technical guidelines and vaccine design. The confirmation of dominant epitopes with a positive serological matrix is feasible. To improve the immunogenicity of the epitope, we designed the dominant epitope of CD2v in the form of 2 branch Multiple-Antigen peptide (MAPs-2), CD2v-MAPs-2. Notably, CD2v peptide can be taken up by dendritic cells (DCs) to activate T lymphocytes and induce highly effective valence antibodies in BALB/c mice. The specific CD8+ T cell response were observed. The dominant epitope peptide identified in this study was able to effectively activate humoral and cellular immunity in mice model.

Identification of Two Novel Linear B Cell Epitopes on the CD2v Protein of African Swine Fever Virus Using Monoclonal Antibodies

African swine fever virus (ASFV) is a highly infectious viral pathogen that endangers the global pig industry, and no effective vaccine is available thus far. The CD2v protein is a glycoprotein on the outer envelope of ASFV, which mediates the transmission of the virus in the blood and recognition of the virus serotype, playing an important role in ASFV vaccine development and disease prevention. Here, we generated two specific monoclonal antibodies (mAbs), 6C11 and 8F12 (subtype IgG1/kappa-type), against the ASFV CD2v extracellular domain (CD2v-ex, GenBank: MK128995.1, 1-588 bp) and characterized their specificity. Peptide scanning technology was used to identify the epitopes recognized by mAbs 6C11 and 8F12. As a result, two novel B cell epitopes, 38DINGVSWN45 and 134GTNTNIY140, were defined. Amino acid sequence alignment showed that the defined epitopes were conserved in all referenced ASFV strains from various regions of China including the highly pathogenic, epidemic strain, Georgia2007/1 (NC_044959.2), with the same noted substitutions compared to the four foreign ASFV wild-type strains. This study provides important reference values for the design and development of an ASFV vaccine and useful biological materials for the functional study of the CD2v protein by deletion analysis.

[Effects of exosomes from hepatocyte growth factor-modified human adipose mesenchymal stem cells on full-thickness skin defect in diabetic mice]

Objective: To investigate the effects and mechanism of exosomes from hepatocyte growth factor (HGF)-modified human adipose mesenchymal stem cells (ADSCs) on full-thickness skin defect wounds in diabetic mice. Methods: The experimental study method was adopted. Discarded adipose tissue of 3 healthy females (10-25 years old) who underwent abdominal surgery in the Department of Plastic Surgery of First Affiliated Hospital of Air Force Medical University from February to May 2021 was collected, and primary ADSCs were obtained by collagenase digestion method and cultured for 7 days. Cell morphology was observed by inverted phase contrast microscope. The ADSCs of third passage were transfected with HGF lentivirus and cultured for 5 days, and then the fluorescence of cells was observed by imaging system and the transfection rate was calculated. The exosomes of ADSCs of the third to sixth passages and the HGF transfected ADSCs of the third to sixth passages were extracted by density gradient centrifugation, respectively, and named, ADSC exosomes and HGF-ADSC exosomes. The microscopic morphology of exosomes was observed by transmission electron microscopy, and the positive expressions of CD9, CD63, and CD81 of exosomes were detected by flow cytometry, respectively. Twenty-four 6-week-old male Kunming mice were selected to make the diabetic models, and full-thickness skin defect wounds were made on the backs of mice. According to the random number table method, the mice were divided into phosphate buffer solution (PBS) group, HGF alone group, ADSC exosome alone group, and HGF-ADSC exosome group, with 6 mice in each group, and treated accordingly. On post injury day (PID) 3, 7, 10, and 14, the wounds were observed and the wound healing rate was calculated; the blood flow intensity of wound base was detected by Doppler flowmeter and the ratio of relative blood flow intensity on PID 10 was calculated. On PID 10, the number of Ki67 positive cells in wounds was detected by immunofluorescence method, and the number of new-vascularity of CD31 positive staining and tubular neovascularization in the wounds was detected by immunohistochemistry method; the protein expressions of protein endothelial nitric oxide synthase (eNOS), phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (Akt) and phosphorylated Akt (p-Akt) in wounds were detected by Western blotting, and the ratios of p-PI3K to PI3K and p-Akt to Akt were calculated. On PID 14, the defect length and collagen regeneration of wound skin tissue were detected by hematoxylin and eosin staining and Masson staining, respectively, and the collagen volume fraction (CVF) was calculated. The number of samples is 3 in all cases. Data were statistically analyzed with repeated measurement analysis of variance, one-way analysis of variance, and Tukey test. Results: After 7 days of culture, the primary ADSCs were spindle shaped and arranged in vortex shape after dense growth. After 5 days of culture, HGF transfected ADSCs of the third passage carried green fluorescence, and the transfection rate was 85%. The ADSC exosomes and HGF-ADSC exosomes were similar in microscopic morphology, showing vesicular structures with an average particle size of 103 nm and 98 nm respectively, and both were CD9, CD63, and CD81 positive. On PID 3, the wounds of mice in the 4 groups were all red and swollen, with a small amount of exudate. On PID 7, the wounds of HGF-ADSC exosome group were gradually reduced, while the wounds of the other three groups were not significantly reduced. On PID 10, the wounds in the 4 groups were all reduced and scabbed. On PID 14, the wounds in HGF-ADSC exosome group were basically healed, while the residual wounds were found in the other three groups. On PID 3, the healing rates of wounds in the four groups were similar (P>0.05); On PID 7 and 10, the wound healing rates in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 13.11, 13.11, 11.89, 12.85, 11.28, and 7.74, respectively, all P<0.01); on PID 14, the wound healing rate in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 15.50, 11.64, and 6.36, respectively, all P<0.01). On PID 3, there was no obvious blood supply in wound base of mice in the 4 groups. On PID 7, microvessels began to form in the wound base of HGF-ADSC exosome group, while the wound base of the other three groups was only congested at the wound edge. On PID 10, microvessel formation in wound base was observed in the other 3 groups except in PBS group, which had no obvious blood supply. On PID 14, the blood flow intensity of wound base in HGF-ADSC exosome group was stronger than that in the other 3 groups, and the distribution was uniform. On PID 10, the ratio of wound base relative blood flow intensity in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 23.73, 19.32, and 9.48, respectively, all P<0.01); The numbers of Ki67-positive cells and new-vascularity of wounds in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 19.58, 18.20, 11.04, 20.68, 13.79, and 8.12, respectively, P<0.01). On PID 10, the protein expression level of eNOS of wounds in HGF-ADSC exosome group was higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 53.23, 42.54, and 26.54, respectively, all P<0.01); the ratio of p-PI3K to PI3K and the ratio of p-Akt to Akt of wounds in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 16.11, 11.78, 6.08, 65.54, 31.63, and 37.86, respectively, P<0.01). On PID 14, the length of skin tissue defect in the wounds of HGF-ADSC exosome group was shorter than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 20.51, 18.50, and 11.99, respectively, all P<0.01); the CVF of wounds in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group and ADSC exosome alone group (with q values of 31.31, 28.52, and 12.35, respectively, all P<0.01). Conclusions: Human HGF-ADSC exosomes can significantly promote wound healing in diabetic mice by increasing neovascularization in wound tissue, and the mechanism may be related to the increased expression of eNOS in wounds by activating PI3K/Akt signaling pathway.

A Pyrazolate Osmium(VI) Nitride Exhibits Anticancer Activity through Modulating Protein Homeostasis in HepG2 Cells

Interest in the third-row transition metal osmium and its compounds as potential anticancer agents has grown in recent years. Here, we synthesized the osmium(VI) nitrido complex Na[Os^VI(N)(tpm)₂] (tpm = [5-(Thien-2-yl)-1H-pyrazol-3-yl]methanol), which exhibited a greater inhibitory effect on the cell viabilities of the cervical, ovarian, and breast cancer cell lines compared with cisplatin. Proteomics analysis revealed that Na[Os^VI(N)(tpm)₂] modulates the expression of protein-transportation-associated, DNA-metabolism-associated, and oxidative-stress-associated proteins in HepG2 cells. Perturbation of protein expression activity by the complex in cancer cells affects the functions of the mitochondria, resulting in high levels of cellular oxidative stress and low rates of cell survival. Moreover, it caused G2/M phase cell cycle arrest and caspase-mediated apoptosis of HepG2 cells. This study reveals a new high-valent osmium complex as an anticancer agent candidate modulating protein homeostasis.

Development of an indirect ELISA for the identification of African swine fever virus wild-type strains and CD2v-deleted strains

African swine fever (ASF) is a potent infectious disease with detrimental effects on the global swine industry and no currently vaccine available. The emergence of low-virulence CD2v-deleted mutants manifested as non-hemadsorption (non-HAD) strains represents a significant challenge to the prevention and control of ASF. In this study, we aimed to establish an indirect ELISA (IELISA) method for the identification of ASFV wild-type and CD2v-deleted strains. We integrated the CD2v protein extracellular domain sequence (CD2v-Ex, 1–588 bp) of the highly pathogenic strain China/2018/AnhuiXCGQ into the genome of suspension culture-adapted Chinese hamster Ovary-S (CHO-S) cells using lentivirus vectors (LVs). By screening, we identified a monoclonal CHO-S cell line that stably expressed secretory CD2v-Ex Protein. We then used the purified CD2v-Ex Protein as the detection antigen to establish an indirect ELISA method (CD2v-IELISA) for identification of the ASFV wild-type and CD2v-Deleted (CD2v−) strains. The CD2v-IELISA method showed excellent specificity with no cross-reaction with serum samples infected with ASFV (CD2v−), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), porcine circovirus (PCV), porcine pseudorabies virus (PRV), swine foot and mouth disease virus (FMDV) and porcine epidemic diarrhea virus (PEDV). Furthermore, this method showed high sensitivity, allowing identification of ASFV-infected clinical serum samples up to a dilution of 1:2,560. The coefficient of variation both in and between batches was &lt;10% with good reproducibility and a high compliance rate of 99.4%. This CD2v-IELISA method developed here is of great significance for the prevention, control and purification of ASFV.

HRP-conjugated-nanobody-based cELISA for rapid and sensitive clinical detection of ASFV antibodies

Abstract

African swine fever (ASF), which is caused by the ASF virus (ASFV), is a highly contagious hemorrhagic disease that causes high mortality to domestic porcine and wild boars and brings huge economic losses to world swine industry. Due to the lack of an effective vaccine, the control of ASF must depend on early, efficient, and cost-effective detection and strict control and elimination strategies. Traditional serological testing methods are generally associated with high testing costs, complex operations, and high technical requirements. As a promising alternative diagnostic tool to traditional antibodies, nanobodies (Nb) have the advantages of simpler and faster generation, good stability and solubility, and high affinity and specificity, although the system is dependent on the immunization of Bactrian camels to obtain the specific VHH library of the target protein. The application of Nbs in the detection of ASFV antibodies has not yet been reported yet. Using a phage display technology, one Nb against the ASFV p54 protein that exhibited high specificity and affinity, Nb8, was successfully screened. A HEK293T cell line stably expressing Nb8-horseradish peroxidase (HRP) fusion protein was established using the lentiviral expression system. Following the optimization of the reaction conditions, the Nb8-HRP fusion protein was successfully used to establish a competitive enzyme-linked immunosorbent assay (cELISA) to detect ASFV-specific antibodies in pig serum, for the first time. There was no cross-reaction with healthy pig serum, porcine pseudorabies virus (PRV), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), porcine epidemic diarrhea virus (PEDV), and classical swine fever virus (CSFV) positive sera. The optimal cut-off value for the cELISA by ROC analysis was 52.5%. A total of 209 serum samples were tested using the developed cELISA and a commercial ELISA kit. The results showed that the relative specificity of the cELISA was 98.97%, and the relative sensitivity of the cELISA was 93.3%, with the percent agreement between the two ELISA methods being 98.56%. In conclusion, a specific, sensitive, and repeatable cELISA was successfully developed based on the Nb8 as a probe, providing a promising method for the detection of anti-ASFV antibodies in clinical pig serum.

Key points

• We successfully screened a specific, high affinity nanobody against ASFV p54 protein.

• We establish a method for continuous and stable expression of Nb-HRP fusion protein using a lentiviral packaging system.

• We establish a nanobody cELISA detection method that can monitor an ASF infection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-11981-4.

[Clinical effects of free transplantation of expanded thoracodorsal artery perforator flaps in reconstructing cervical cicatrix contracture deformity after burns]

Objective: To explore the clinical effects of free transplantation of expanded thoracodorsal artery perforator flaps in reconstructing cervical cicatrix contracture deformity after burns. Methods: A retrospective observational study was conducted. From May 2018 to April 2021, 11 patients with cervical cicatrix contracture deformity after burns who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University, including 3 males and 8 females, aged 5 to 46 years, with a course of cervical cicatrix contracture deformity of 5 months to 8 years. The degree of cervical cicatrix contracture deformity was degree Ⅰ in one patient, degree Ⅱ in nine patients, and degree Ⅲ in one patient. In the first stage, according to the sizes of neck scars, one rectangular skin and soft tissue expander (hereinafter referred to as expander) with rated capacity of 200 to 600 mL was placed in the back. The expansion time was 4 to 12 months with the total normal saline injection volume being 3.0 to 3.5 times of the rated capacity of expander. In the second stage, free expanded thoracodorsal artery perforator flaps with areas of 10 cm×7 cm to 24 cm×13 cm were cut out to repair the wounds with areas of 9 cm×6 cm to 23 cm×12 cm which was formed after cervical cicatectomy. The main trunk of thoracodorsal artery and vein were selected for end-to-end anastomosis with facial artery and vein, and the donor sites were directly closed. The survival of flaps and healing of flap donor sites were observed on the 14th day post surgery. The appearances and cicatrix contracture deformity of the flaps, recovery of cervical function, and scar hyperplasia of donor sites were followed up. Results: On the 14th day post surgery, the flaps of ten patients survived, while ecchymosis and epidermal necrosis occurred in the center of flap of one patient and healed 2 weeks after dressing change. On the 14th day post surgery, the flap donor sites of 11 patients all healed well. During the follow-up of 6-12 months post surgery, the flaps of ten patients were similar to the skin around the recipient site in texture and color, while the flap of one patient was slightly swollen. All of the 11 patients had good recovery of cervical function and no obvious scar hyperplasia nor contracture in the flaps or at the donor sites. Conclusions: Application of expanded thoracodorsal artery perforator flaps can restore the appearance and function of the neck, and cause little damage to the donor site in reconstructing the cervical cicatrix contracture deformity after burns, which is worthy of clinical reference and application.

Proteomic Investigation Reveals Eukaryotic Translation Initiation Factor 5A Involvement in Porcine Reproductive and Respiratory Syndrome Virus Infection in vitro

Porcine reproductive and respiratory syndrome virus (PRRSV), one of the most serious animal pathogens in the world, has caused enormous global swine industry losses. An in-depth investigation of the PRRSV-host interaction would be beneficial for preventing and controlling PRRSV infections and transmission. In this study, we performed label-free quantitative proteomic assays to investigate proteome dynamics of porcine alveolar macrophages (PAMs) during infection with highly pathogenic PRRSV (HP-PRRSV) strain HN07-1. Analysis of the results led to identification of 269 significantly differentially expressed host cellular proteins, of which levels of proteins belonging to the eukaryotic translation initiation factor (eIF) family were found to be decreased in abundance in HP-PRRSV-infected PAMs. Furthermore, knockdown of eIF5A expression was demonstrated to markedly suppress HP-PRRSV propagation, as reflected by reduced progeny virus titers in vitro. These results highlight the importance of eIF5A in PRRSV infection, while also demonstrating that PAMs down-regulate eIF5A expression as a host cell antiviral strategy. Results of the current study deepen our understanding of PRRSV pathogenesis and provide novel insights to guide development of effective strategies to combat the virus.

[Implantation of a monofocal intraocular lens after femtosecond laser intrastromal keratotomy and contralateral implantation of a trifocal IOL: a case report]

An age-related cataract patient who underwent femtosecond laser intrastromal keratotomy in the right eye for presbyopia correction 8 years ago was subjected to femtosecond laser-assisted phacoemulsification, with implantation of a monofocal intraocular lens (IOL) and a trifocal IOL in the right and left eyes, respectively. The corneal stromal ring was complementary to the monofocal IOL, which recovered the distance and near visual acuity, in the right eye postoperatively. The trifocal IOL provided good intermediate visual acuity for the left eye. The vision of the patient reached an ideal level for all visual distances. The binocular fusion was within the normal range, and the stereoscopic vision was restored. We hope that this case report can act as a reference for the treatment of cataract after presbyopia corrective surgery.

Knowledge is Power: Pathology Activity Booths in Community Health Fairs

Introduction/Objective

Our pilot project “Pathology Activity Booths” is an innovative approach to investigating whether pathology activity exhibits at health fairs could increase access and promote learning and understanding of health topics and pathology of diseases. Health fairs are an effective form of community-based health promotion conducted in many underserved communities.

Methods/Case Report

Booth #1 (Colorectal Cancer Awareness Fair): Microscopes with histology slides of colon biopsies, with enlarged corresponding colonoscopy images, were displayed showing the histology of normal colon, abnormal colon and cancer (colon adenocarcinoma).

Booth #2 (Children’s Back-To-School Fair): Microscopes with histology slides of normal skin, lung, kidney, liver, intestine, and brain tissue were shown.

Post participation surveys assessed whether participants knew anyone with the diseases presented, had previous experience with microscopes, and/or felt they understood and learned from their experience at the booth.

Results (if a Case Study enter NA)

There were 71 total participants. At Booth #1, 100% (42/42) of participants stated they understood what they saw under the microscope and 95% (40/42) felt they learned something new. At Booth #2, 86% (25/29) of participants stated they understood what they saw under the microscope and 76% (22/29) stated they learned something new. One participant exclaimed she would now make her husband get the colonoscopy he had been avoiding.

Conclusion

The overwhelmingly positive responses indicate that pathology booths could be promising in promoting health knowledge in our patient population. Greater understanding of health topics may lead to increased use of screening tests that can ultimately improve health outcomes. Pathologists are well suited to be direct resources of accurate information for patients. As physicians who closely evaluate human disease, we can effectively provide access to a new, different and engaging perspective to community health education. Pathology activity booths may be a valuable resource for patients, an innovative method of teaching the community and a creative tool to enhance trainees’ experience and teaching ability.

JS01.4.A The neurocognitive function changes with awake craniotomy for low-grade glioma in the left hemispheric eloquent regions

BACKGROUND

Cognitive deficit was frequently observed in glioma patients, especially for those on the eloquent area. Considering the increased life expectancy, brain mapping during awake craniotomy was preferentially applied to exacerbate neurocognitive deficits. The aim of the current study was to evaluate the neurocognitive changes during the perioperative period of resection of low-grade glioma (LGG) in the left side eloquent area with awake craniotomy in a major neurosurgical center in China for 5 years.

MATERIAL AND METHODS

We retrospectively analyzed patients with left-sided glioma in eloquent areas, who received awake craniotomy during 2016–2020. Montreal Cognitive Assessment Scale, BN-20, and EORTC-QLQ-C30 questionnaire were applied for neurological cognitive assessment. We performed a correlation analysis between changes in cognitive performance and tumor characteristics, including tumor location, pathological grade. Treatment-related factors were also analyzed, such as the extent of resection (EOR), preoperative and postoperative Karnofsky Performance Score (KPS), postoperative treatment strategy (chemo- and radiotherapy), progression-free survival (PFS), overall survival (OS).

RESULTS

68 patients were included in our current study. For the language domain, memory domain, and executive functions, 7.4% (5/68) patients presented mild postoperative cognitive performance deterioration compared to preoperative. Tumor location was the only factor that greatly influenced the postoperative cognitive performance, while other features (EOR, KPS, pathological grades) and treatment strategy were found no effect on cognitive change. The extent of tumor resection ranged from 81% to 100%.

CONCLUSION

Our study underlines the importance of the application of brain mapping during awake craniotomy, which helps to maximize extent of tumor resection while preserving cognitive function in individuals with LGG in eloquent regions.

[Study on the expression of p62 protein in patients with lung adenocarcinoma]

To explore the expression of p62 protein in lung adenocarcinoma (LUAD). In this study, a cross-sectional study was adopted. From December 2011 to May 2013, 60 patients with lung adenocarcinoma who were diagnosed and treated in Tongji Hospital of Tongji University, Shanghai were selected for paraffin embedding and tissue chip preparation, and immunohistochemistry (IHC) technology was used to detect the expression of p62 in lung adenocarcinoma patients' cancer tissues and adjacent tissues, and analyze the relationship between p62 expression and the clinicopathological characteristics and survival prognosis of patients with lung adenocarcinoma; at the same time, 6 cases of lung adenocarcinoma were selected by random sampling cancer tissues and adjacent tissues were detected by Western Blot (WB) to detect p62 protein and analyzed by gray value. Preoperative examination specimens of inpatients with lung adenocarcinoma diagnosed from April 2018 to early October 2019, and plasma specimens of healthy subjects were collected, and enzyme linked immunosorbent assay (ELISA) was used to detect lung adenocarcinoma patients and healthy patients. The expression of p62 in the plasma of the subjects was statistically analyzed using SPSS 22.0 software. The results of IHC showed that the positive expression rate of p62 in cancer tissues was significantly higher than that in adjacent tissues, and the difference was statistically significant (t=5.593, P<0.001). Similarly, WB results showed that the expression of p62 protein in cancer tissues was significantly higher than that in adjacent tissues. It is statistically relevant (t=2.238, P=0.049). The expression of p62 was statistically correlated with tumor size, clinicopathological stage and lymph node metastasis in patients with lung adenocarcinoma (all P<0.05). The overall survival of patients with lung adenocarcinoma with high p62 expression was worse than that of patients with low p62 expression (95%CI was 0.238-0.870, P=0.028), suggesting that the high expression of p62 is related to the poor prognosis of patients with lung adenocarcinoma. The level of p62 protein in the plasma of patients with lung adenocarcinoma was significantly higher than that in the healthy control group. The difference was statistically significant (t=8.533, P<0.001). The area under the receiver operating characteristic curve was 0.835 (95%CI was 0.779-0.891, P<0.001), which is significantly higher than CEA, CA125, CA153 and other single traditional indicators, and the combined detection of four indicators has the highest diagnostic efficiency. p62 was strongly expressed in cancer tissues and serum, which is related to the poor prognosis and overall survival rate of LUAD patients.

[Expert consensus on the treatment of oral and maxillofacial space infections]

Oral and maxillofacial space infections (OMSI) are common diseases of the facial region involving fascial spaces. Recently, OMSI shows trends of multi drug-resistance, severe symptoms, and increased mortality. OMSI treatment principles need to be updated to improve the cure rate. Based on the clinical experiences of Chinese experts and with the incorporation of international counterparts' expertise, the principles of preoperative checklist, interpretation of examination results, empirical medication principles, surgical treatment principles, postoperative drainage principles, prevention strategies of wisdom teeth pericoronitis-related OMSI, blood glucose management, physiotherapy principles, Ludwig's angina treatment and perioperative care were systematically summarized and an expert consensus on the diagnosis and treatment of OMSI was reached. The consensus aims to provide criteria for the diagnosis and treatment of OMSI in China so as to improve the level of OMSI treatment.

Development of a Directly Visualized Recombinase Polymerase Amplification-SYBR Green I Method for the Rapid Detection of African Swine Fever Virus

African swine fever (ASF) is a lethal disease in swine caused by etiologic African swine fever virus (ASFV). The global spread of ASFV has resulted in huge economic losses globally. In the absence of effective vaccines or drugs, pathogen surveillance has been the most important first-line intervention to prevent ASF outbreaks. Among numerous diagnostic methods, recombinase polymerase amplification (RPA)-based detection is capable of producing sensitive and specific results without relying on the use of expensive instruments. However, currently used gene-specific, probe-based RPA for ASFV detection is expensive and time-consuming. To improve the efficiency of ASFV surveillance, a novel directly visualized SYBR Green I-staining RPA (RPAS) method was developed to detect the ASFV genome. SYBR Green I was added to the amplified RPA products for direct visualization by the naked eye. The sensitivity and specificity of this method were confirmed using standard plasmid and inactivated field samples. This method was shown to be highly specific with a detection limit of 10³ copies/μl of ASFV in 15 min at 35°C without any cross-reactions with other important porcine viruses selected. In summary, this method enables direct sample visualization with reproducible results for ASFV detection and hence has the potential to be used as a robust tool for ASF prevention and control.

[Clinical effects of combined application of skin-stretching device and vacuum sealing drainage in repairing the diabetic foot wounds]

Objective: To investigate the clinical effects of skin-stretching device (hereinafter referred to as stretcher) combined with vacuum sealing drainage (VSD) in repairing diabetic foot wounds. Methods: From March 2016 to January 2020, 25 patients with diabetic foot wounds were admitted to the First Affiliated Hospital of Air Force Medical University, including 18 males and 7 females, with age of 40 to 70 years. After debridement, intermittent VSD was performed for 3 to 10 days, with negative pressure value of -10.67 kPa. Then, the wound area was 5.0 cm×3.0 cm to 10.0 cm×7.0 cm. After infection control and detumescence, the wound was treated with stretcher for 3 to 5 days. The wound area after stretching ranged from 5.0 cm×0.3 cm to 10.0 cm×0.5 cm. The wound was closed with full-thickness suture. Two weeks after the suturing operation, the healing grade of the foot wound of patients was observed, and the serious complications such as recurrence of ulcer wound and gangrene on the foot, scar condition of the wound were observed during follow-up. Results: Two weeks after the suturing operation, the wounds of 23 patients were healed with grade A. Soft tissue infection ulcer relapsed in 2 patients during the stretch period. After anti-infection, thorough debridement, and VSD, the wounds were healed after another 16 days of stretch treatment. During the follow-up of 3 to 36 months, 23 patients had linear scar left on the stretch wounds, and the skin elasticity, color, sensation was similar to the surrounding normal tissue, and the limb mobility was good, and 2 patients had obvious scar hyperplasia. One patient had recurrence of diabetic foot and serious vascular occlusion and gangrene in the affected limb at follow-up of 10 months, which was treated with amputation of the lower leg. Conclusions: The use of stretcher combined with VSD in treating diabetic foot wound can avoid donor site injury, with healed wound achieving similar appearance to adjacent skin and satisfactory repair effects.

[Assessment of the clinical effect regarding three-dimensional printing individualized titanium mesh for bone augmentation in the esthetic area]

Objective: To evaluate the clinical effect of three-dimensional (3D) printing individualized titanium mesh for ridge augmentation in the esthetic zone. Methods: Forty-three patients were treated with personalized titanium mesh bone augmentation from Department of Oral Implantology, Stomatological Hospital of Chongqing Medical University from January, 2018 to June, 2020. According to the preoperative cone-beam CT (CBCT) data, the 43 patients [male: 21, female: 22, aged (30.1±5.8) years] were divided into three groups according to the Seibert classification as horizontal, vertical and horizontal-vertical classes (sample size: 14, 15, 14). Then, comprehensively the bone mass and esthetic requirements were taken into account to design and accordingly fabricate the 3D printing individualized titanium mesh. During the surgical process, autologous bone and xenogeneic bone substitutes were mixed at a 1∶1 ratio, combined with injectable platelet-rich fibrin (i-PRF) and individualized titanium mesh for ridge augmentation. All patients were recalled at 1, 3, and 6 months post-operation to observe the mesh exposure; the clinical effect of ridge augmentation was evaluated 6 months post-operation. After the implant placement and final restoration, the pink esthetic score (PES)/white esthetic score (WES) were evaluated. Results: Only one patient experienced early mesh exposure, and no obvious infection was observed. The bone gain regarding three types of bone defects was significantly higher immediately post-operation compared to pre-operation (horizontal, vertical and horizontal-vertical bone defect measured as (3.27±0.13), (17.41±0.46), (3.76±0.24), (14.37±0.89) mm pre-operation, respectively; and (5.25±0.15), (26.10±0.55), (6.35±0.29), (22.52±0.90) mm immediately post-operation, P<0.01). There was no obvious bone resorption 6 months post-operation [outcomes for horizontal, vertical and horizontal-vertical bone defect measured as (5.14±0.14), (25.67±0.52), (6.13±0.26), (22.35±0.89) mm, P>0.05]. The PES/WES scores of all patients were interpreted as "excellent". Conclusions: The 3D printing individualized titanium mesh is effective in repairing bone defects in the esthetic zone, and produces credible esthetic outcomes after implantation and final restoration.

Genomic Signature of Mismatch Repair Deficiency in Areca Nut-Related Oral Cancer

Areca nut (AN) chewing contributes to an increase of oral squamous cell carcinoma (OSCC) cases in South and Southeast Asia; however, genomic events underlying the carcinogenesis process of AN-related OSCC remain unclear. Here, we comprehensively describe the genomic and transcriptome alterations of 113 Chinese OSCC patients (89 AN related and 24 AN negative) by whole-exome sequencing and RNA sequencing, and we compared the genomic differences between AN-related and AN-negative samples by integrating sequencing data of 325 OSCC patients from The Cancer Genome Atlas database and 50 from a published Taiwanese study. We identified 11 significantly mutated genes for OSCC, including 4 novel ones (ATG2A, WEE1, DST, and TSC2), of which WEE1 and ATG2A mutated with significantly higher rates in AN-related samples (P = 0.04 and P = 0.003, respectively). Mutational signature analysis revealed that AN-related OSCCs were specially characterized by the genomic signature of mismatch repair deficiency (dMMR), which could also predict the prognosis status of AN-related OSCC. In addition, an elevated PD-L1 expression was also observed in both AN-related patients (P = 3.71 × 10^-11) and those with a high dMMR level (P = 1.99 × 10^-4). Further differential expression analysis and in vitro experiments confirmed the role of dMMR in the development of OSCC induced by AN exposure. Taken together, this study first revealed the molecular profiles and highlighted the role of dMMR in AN-related OSCC among the Chinese population and identified that AN-related OSCC may represent a potential cohort for effective anti-PD-1/L1 immunotherapy.

SAT0250 CLINICAL CHARACTERISTICS AND THE DISEASE ACTIVITY OF BEHCET’S DISEASE IN CHINA: A STUDY BASED ON SMART SYSTEM OF DISEASE MANAGEMENT (SSDM)

Background:

Behcet´s disease (BD) is a systemic autoimmune disease that affects multiple organ systems with recurrent oral ulcers, genital ulcers and skin lesions. Behcet´s Disease Current Activity Form (BDCAF) and Electronic Medical Record-based Activity Index (EMRAI) are commonly used internationally to evaluate the disease activity of BD.

Objectives:

This study aimed to analyze the clinical characteristics, the level of disease activity, and the incidence of anxiety and depression for Chinese BD patients. Patients can perform self-management of disease with SSDM.

Methods:

SSDM is a series of doctor-patient interactive applications for self-management of patients with chronic diseases. Patients can perform self-assessment with SSDM and upload the data to their authorized doctors. The SSDM patients’ application system integrates the BDCAF and EMRAI into one scoring system. Patients could obtain scores of BDCAF and EMRAI by responding to one questionnaire through SSDM.

Results:

From Apr 2017 to Jan 2020, 719 BD patients from 166 hospitals used SSDM, with a mean age of 38.97±12.71 (14~81) years old, and median disease duration of 20.8 months. 719 patients performed BDCAF and EMRAI self-assessment 1321 times, 252 patients repeat assessments for 855 times. The mean score of BDCAF and EMRAI are 3.57±2.17 and 3.44±1.90, respectively. The matching degree of the two score was 0.8747.

The most common clinical characteristics were oral ulcers (83.73%), ocular symptoms (62.03%), joint pain (50.07%). The comparative study between males and females revealed significant difference in the aspects of epididymitis (10.94% vs 0, p<0.001), genital ulcer (35.09% vs 44.93%, p=0.01), headache (24.15% vs 33.92%, p=0.01) and superficial thrombophlebitis (24.15% vs 33.92%, p=0.01). Table 1.

Table 1.

Clinical Characteristics of different systems in Chinese BD patients.

Presence of clinical characteristicsTotalMalesFemalesP valueOral ulcer83.73% (602)86.42% (229)82.16% (373)0.14Genital ulcer41.31% (297)35.09% (93)44.93% (204)0.01*Epididymitis4.03% (29)10.94% (29)0 (0)<0.001**Erythema29.49% (212)29.43% (78)29.52% (134)0.98Skin lesions26.84% (193)28.68% (76)25.77% (117)0.4Superficial thrombophlebitis30.32% (218)24.15% (64)33.92% (154)0.01*Headache30.32% (218)24.15% (64)33.92% (154)0.01*Joint pain50.07% (360)51.32% (136)49.34% (224)0.61Arthritis14.60% (105)14.72% (39)14.54% (66)0.95Gastrointestinal involvement24.90% (179)27.92% (74)23.13% (105)0.15Ocular symptoms62.03% (446)62.64% (166)61.67% (180)0.79Nervous involvement23.78% (171)25.66% (68)22.69% (103)0.37Vascular involvement15.72% (113)18.11% (48)14.32% (65)0.18

*P values are for the comparison between the males and females.

Conclusion:

Chinese BD patients can effectively perform BDCAF and EMRAI self-assessment with SSDM. The results of the assessment conducted by the two scoring systems are similar. The clinical characteristics of Chinese BD were different depending on gender.

Acknowledgments: :

Smart system of disease management (SSDM) was developed by Shanghai Gothic Internet Technology Co., Ltd.

Disclosure of Interests:

None declared

FRI0143 THE EFFICACY AND COST-EFFECTIVENESS OF HYDROXYCHLOROQUINE, SULFASALAZINE, METHOTREXATE TRIPLE THERAPY IN PREVENTING RELAPSE OF RHEUMATOID ARTHRITIS

Background:

TNFα inhibitors (TNFi) is effective for rheumatoid arthritis (RA) patients refractory to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), but because of high cost, the discontinuation is common that often lead to disease relapse.

Objectives:

To investigate, among RA patients refractory to csDMARDs but achieved therapy target after treated with TNFi and methotrexate (MTX), if the combination therapy of csDMARDs is more effective in reducing disease relapse than MTX monotherapy, and more cost-effective than continuing the treatment with TNFi and MTX.

Methods:

In this multi-center, outcome assessment blinded, randomized, superiority clinical trial, RA patients who failed to csDMARDs treatment (DAS28(CRP)>3.2) received MTX plus TNFi for 12 weeks first (induction therapy). Then patients achieving low disease activity [LDA, DAS28(CRP)<3.2] were randomized into three groups in 1:1:1 ratio: (A) maintaining TNFi + MTX for 60 weeks; (B) adding hydroxychloroquine (HCQ) and sulfasalazine (SSZ) for 12 weeks and then removing TNFi but continuing HCQ and SSZ for 48 weeks; and (C) maintaining TNFi + MTX for 12 weeks and then removing TNFi but continuing MTX only for 48 weeks. The primary outcome is disease relapse [DAS28(CRP) increased by at least 0.6 and >3.2] in 60 weeks. Secondary outcomes include the incremental cost effectiveness ratio (incremental cost per reducing 1% relapse rate); adverse events and radiology progression.

Results:

117 patients were enrolled for induction therapy. 67 patients achieved LDA after 12 weeks of induction therapy and were randomized with 21, 24 and 22 patients into each group, respectively. Male [OR=0.046 (0.005-0.451), p=0.008] and less baseline tender joint count [OR=0.825 (0.710-0.958), p=0.012] were independent predictive factors for LDA achievement. The relapse rate in 60 weeks was comparable between group A and B [33.3% (7/21) vs. 37.5% (9/24), p>0.05], while both significantly lower than that of group C [77.3% (17/22), p<0.01, p<0.01, respectively]. The adverse events and modified Sharp score progression were both comparable among the three groups. The incremental cost effectiveness ratio of group A is higher than group B (1315.7 yuan vs 101.5 yuan).

Conclusion:

For RA patients refractory to csDMARDs but achieved therapy target after treated with TNFi and MTX, the triple therapy of MTX+HCQ+SSZ is as effective as and more cost-effective than TNFi maintain therapy in reducing disease relapse. Both strategies are more effective than MTX monotherapy.

References:

[1]Smolen JS, Landewé R, Bijlsma J, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease- modifying antirheumatic drugs: 2016 update.Ann Rheum Dis. 2017 Jun; 76(6):960-977.

[2]Smolen JS, Nash P, Durez P, et al. Maintenance, reduction, or withdrawal of etanercept after treatment with etanercept and methotrexate in patients with moderate rheumatoid arthritis (PRESERVE): a randomized controlled trial. Lancet. 2013;381(9870):918-29.

[3]Rantalaiho V, Sandström T, Koski J, et al. Early Targeted Combination Treatment with csDMARDs Sustains Excellent Long-term Outcomes in Rheumatoid Arthritis. Arthritis Care Res (Hoboken). 2018 Oct 8.

[4]Henaux S, Ruyssen-Witrand A, Cantagrel A, et al. Risk of losing remission, low disease activity or radiographic progression in case of bDMARD discontinuation or tapering in rheumatoid arthritis: systematic analysis of the literature and meta- analysis. Ann Rheum Dis 2018;777:515-22.

Disclosure of Interests:

None declared

[Effects of anterolateral thigh free flap with fascia lata in repairing dura mater defect after resection of head squamous cell carcinoma]

Objective: To evaluate the clinical effects of anterolateral thigh free flap with fascia lata in the repair of dura mater defect after resection of head squamous cell carcinoma. Methods: From June 2016 to June 2018, Xijing Hospital of Air Force Medical University applied the free transplantation of anterolateral thigh flap with fascia lata to repair the dura mater defect of 12 patients with head squamous cell carcinoma, including 9 males and 3 females, aged from 35 to 74 years. The size of scalp soft tissue defects in patients after carcinoma resection ranged from 12 cm×10 cm to 24 cm×21 cm, and the size of dura mater defect of patients ranged from 7 cm×6 cm to 16 cm×14 cm. The size of flap of patients ranged from 14 cm×12 cm to 27 cm×24 cm, and the size of fascia lata ranged from 8 cm×7 cm to 17 cm×15 cm. The superficial temporal artery and middle temporal vein were connected by end to end anastomosis with the first musculocutaneous perforating branch of the descending branch of lateral femoral artery and its accompanying vein. The flap donor area was transplanted with autologous split-thickness skin graft from trunk and fixed with packing. Postoperative survival of flaps and skin grafts was observed. The patients were followed up regularly. The cranial magnetic resonance imaging was performed to observe the recurrence of intracranial tumors and dural integrity, shape of the flap and whether the donor site region was left with significant dysfunction were observed. Results: All the flaps and skin grafts survived well in 12 patients after surgery. Ten patients had primary healing at the edge of the flap suture; 2 patients had local sinus tract formation at the suture site of flap, with a small amount of cerebrospinal fluid leakage, and were recovered after outpatient dressing change. The patients were followed up for 10 to 36 months, and 3 patients with tumors involving in the dura mater sagittal sinus region had postoperative intracranial tumor recurrence. The tumor was resected again. All the patients had good dural integrity. The flaps of all patients were in good shape, and no obvious dysfunction remained in the flap donor site. Conclusions: Free transplantation of anterolateral thigh flap with fascia lata is an effective and reliable method to repair the dura mater defect following head squamous cell carcinoma resection. It can repair the scalp and dura mater defects caused by the invasion of squamous cell carcinoma and provide possibilities for skull reconstruction.

[Effect of silent information regulator 1 on the LPS induced lncRNA expression of macrophages in mice]

Objective: To investigate the effect of Silent information regulator 1 (Sirt1) on the expression profile of long non-coding RNA (lncRNA) in macrophages upon lipopolysaccharide (LPS) treatment. Methods: Peritoneal macrophages (PM) were isolated from nine wild-type C57BL/6 male mice (wild-type group) and nine myeloid-specific Sirt1 knock-out mice (knock-out group). RNA samples were extracted from macrophages stimulated with 1 μg/ml LPS. Sequencing and the differentially expressed lncRNA were screened after the RNA was quantified. The threshold set for up-and down-regulated genes was a fold change (wild-type group/knock-out group) ≥2 and P≤0.05. Afterwards, gene ontology (GO) and pathway enrichment analysis were conducted and co-expression network map was constructed. Results: Four hundred and forty five lncRNA genes were differentially expressed (185 lncRNA genes were up-regulated and 260 lncRNA genes were down-regulated). Two hundred mRNA genes were differentially expressed (113 mRNA genes were up-regulated and 87 mRNA genes were down-regulated). It was found that the differentially expressed lncRNA genes and the predicted corresponding target genes were mainly distributed in the regions of biological processes of macrophage inflammatory response, macrophage chemotaxis and cell metabolism by GO and pathway enrichment analysis. Conclusion: lncRNA expression profile changes significantly in LPS induced macrophages isolated from Sirt1 knock out mice, which is closely related to the function of macrophages.

The Cytoprotective Enzyme Heme Oxygenase-1 Suppresses Pseudorabies Virus Replication in vitro

Pseudorabies virus (PRV) infection brings about great economic losses to the swine industry worldwide, as there are currently no effective therapeutic agents or vaccines against this disease, and mutations in endemic wild virulent PRV strains result in immune failure of traditional vaccines. Heme oxygenase-1 (HO-1) catalyzes the conversion of heme into biliverdin (BV), iron and carbon monoxide (CO), all of which have been demonstrated to protect cells from various stressors. However, the role of HO-1 in PRV replication remains unknown. Thus, the present study aimed to investigate the effect of HO-1 on PRV replication and determine its underlying molecular mechanisms. The results demonstrated that induction of HO-1 via cobalt-protoporphyrin (CoPP) markedly suppressed PRV replication, while HO-1 specific small interfering RNA or inhibitor zinc-protoporphyrin partially reversed the inhibitory effect of CoPP on PRV replication. Furthermore, overexpression of HO-1 notably inhibited PRV replication, while knockdown of endogenous HO-1 expression promoted PRV replication. Mechanism analyses indicated that the HO-1 downstream metabolites, CO and BV/BR partially mediated the virus suppressive effect of HO-1. Taken together, the results of the present study suggest that HO-1 may be developed as a novel endogenous antiviral factor against PRV, and the HO-1/BV/CO system may constitute a unique antiviral protection network during PRV infection and interaction with host cells.

Effects of sophorolipids on fungal and oomycete pathogens in relation to pH solubility

AIMS

The objective of this study was to determine the effects of sophorolipids on several fungal and oomycete plant pathogens and the relationship between sophorolipids at different pH and antimicrobial activities.

METHODS AND RESULTS

Sophorolipids had different solubility at different pH with a dramatic increase in solubility when pH was 6 or higher. Inhibition of mycelial growth of Phytophthora infestans by sophorolipids was affected by pH values, showing that when the pH value was higher, the inhibition rate was lower. Sophorolipids inhibited spore germination and mycelial growth of several fungal and oomycete pathogens in vitro including Fusarium sp., F. oxysporum, F. concentricum, Pythium ultimum, Pyricularia oryzae, Rhizoctorzia solani, Alternaria kikuchiana, Gaeumannomyces graminis var. tritici and P. infestans and caused morphological changes in hyphae by microscope observation. Sophorolipids reduced β-1,3-glucanase activity in mycelia of P. infestans. In greenhouse studies, foliar application of sophorolipids at 3 mg ml^-1 reduced severity of late blight of potato caused by P. infestans significantly.

CONCLUSION

Sophorolipids influenced spore germination and hyphal tip growth of several plant pathogens and pH solubility of sophorolipids had an effect on their efficacy. Application of sophorolipids reduced late blight disease on potato under greenhouse conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings indicated that sophorolipids have the potential to be developed as a convenient and easy-to-use formulation for managing plant diseases.

Halitosis: prevalence, risk factors, sources, measurement and treatment - a review of the literature

Halitosis, an offensive breath odour, has multiple sources and negative impacts on people's social interactions and quality of life. It is important for health care professionals, including general physicians and dental professionals, to understand its aetiology and risk factors in order to diagnose and treat patients appropriately. In this study, we have reviewed the current literature on halitosis regarding its prevalence, classification, risk factors, sources, measurement and treatment.

Population structure and genetic diversity of Setosphaeria turcica from corn in Heilongjiang province, China

AIM

The aims of this study were to identify races and mating types of Setosphaeria turcica causing northern corn leaf blight in Heilongjiang province of China and analyse the genetic diversity of S. turcica isolates using SSR markers.

METHODS AND RESULTS

Based on gene-for-gene interactions, 13 races of S. turcica (races 0, 1, 2, 3, 12, 13, 23, 123, N, 1N, 12N, 3N and 23N) were isolated from infected corn plants in Heilongjiang province. Races 0 and 1 were the predominant races, and race 23N was identified for the first time in the region. Using two pairs of specific primers, three mating types, 'a', 'Aa' and 'A', were identified, with 'a' being the predominant mating type. SSR markers were used to analyse genetic diversity of 60 S. turcica isolates. Five SSR primers were polymorphic, which resulted in 45 reproducible bands with 2-15 bands for each primer. Cluster analysis separated the isolates into five groups at a similarity coefficient of 0·84. Analysis of molecular variance showed that there was significant correlation between SSR groups and mating type of the isolates. No significant correlation was found between SSR groups and physiological races or geographical location of the isolates.

CONCLUSIONS

The work reported that races 0 and 1 were the predominant races, and race 23N was identified for the first time in Heilongjiang province with 'a' being the predominant mating type. There was significant correlation between SSR groups and mating type of S. turcica isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide information on population structure and genetic diversity of S. turcica causing Northern corn leaf blight, which will facilitate the development of effective disease management programs.

[Role of PD-1/PD-L1 in microenvironment of breast cancer]

Programmed cell death protein 1 (PD-1), as a checkpoint of the immune signaling pathway, is a hotspot in the field of immuno-oncology. Its binding with ligand (PD-L1) is an important negative regulatory mechanism. Application of PD-1/PD-L1 inhibitors in treatments of breast cancer is still being explored at present. Fully understanding the mechanism of PD-1/PD-L1 in the microenvironment of breast cancer will help their inhibitors play a full role. This review will start with the discovery of PD-1 and PD-L1, describe their main signaling pathways, introduce the common types and applications of PD-1/PD-L1 inhibitors, especially in breast cancer, summarize the basic research of PD-1 and PD-L1 in breast cancer microenvironment in recent years, and seek new strategies of PD-1/PD-L1 inhibitors in breast cancer treatment.

Self-assembly of 5,6-dihydroxyindole-2-carboxylic acid: polymorphism of a eumelanin building block on Au(111)

Investigating two-dimensional (2D) self-assembled structures of biological monomers governed by intermolecular interactions is a prerequisite to understand the self-assembly of more complex biomolecular systems. 5,6-Dihydroxyindole carboxylic acid (DHICA) is one of the building blocks of eumelanin - an irregular heteropolymer and the most common form of melanin which has potential applications in organic electronics and bioelectronics. By means of scanning tunneling microscopy, density functional theory and Monte Carlo calculations, we investigate DHICA molecular configurations and interactions underlying the multiple 2D patterns formed on Au(111). While DHICA self-assembled molecular networks (SAMNs) are dominated by the hydrogen bonding of carboxylic acid dimers, a variety of 2D architectures are formed due to the multiple weak interactions of the catechol group. The hydroxyl group also allows for redox reactions, caused by oxidation via O2 exposure, resulting in molecular rearrangement. The susceptibility of the molecules to oxidation is affected by their SAMNs architectures, giving insights on the reactivity of indoles as well as highlighting non-covalent assembly as an approach to guide selective oxidation reactions.

Abstract P4-09-09: Association between socioeconomic factors at diagnosis and survival in non-metastatic breast cancer: A population-based study

Background: Breast cancer is a severe public health problem for women worldwide. Race disparities and regional disparities are documented regarding incidence, mortality, and survival of breast cancer patients. However, the associations between socioeconomic status and survival outcomes of breast cancer remain unclear and require a comprehensive large-scale investigation of specific socioeconomic factors. Furthermore, no model has included both histological and socioeconomic factors together to predict survival of breast cancer. In this study, we sought to develop nomograms to predict overall survival (OS) and breast cancer-specific survival (BCSS) with consideration of socioeconomic factors for non-metastasis breast cancer.

Methods: We included a total of 274,108 female patients, diagnosed with malignant breast cancer between 2007 and 2014from the Surveillance, Epidemiology, and End Results (SEER) database. Socioeconomic factors involving marital status, insurance status, residence, median household income, poverty rate, unemployment rate and education level were included in the analysis. OS and BCSS were evaluated with log-rank tests and Kaplan-Meier estimates. We identified and integrated significant prognostic factors for OS and BCSS using univariate and multivariate Cox regression analysis to construct nomograms. Calibration plots and concordance indexes were used to evaluate the accuracy and discrimination of the models.

Results: Among different age subgroups, insured patients were more likely to have better survival than uninsured patients or patients with Medicaid (P&lt;0.001), and especially for patients who were aged 18 to 35 years old at diagnosis, uninsured patients associated with poor BCSS than Medicaid patients (P&lt;0.05). Through multivariate analysis, we found non-Hispanic black patients experienced worst survival compared with the White and other races (P&lt;0.001). Interestingly, married (vs. single vs. separated/divorced/widowed; P&lt;0.001) and insured (vs. Medicaid vs. uninsured; P&lt;0.001) patients had a better prognosis. Living in the non-metro area increased the risk of death (hazard ratio [HR], 1.084, P&lt;0.05). Furthermore, living in counties with higher median household income (&gt;US $72,800) had favorable impacts on OS (HR 0.843, P&lt;0.001). Four and five socioeconomic factors were involved in constructing the nomograms for 3 years-, 5 years- and 7 years- OS and BCSS, respectively. The C-indexes of the final nomograms were higher than those of the TNM staging system for predicting OS (0.776 vs 0.678; P &lt; 0.001) and BCSS (0.842 vs 0.776; P &lt; 0.001), respectively. The performance of the nomograms for predicting OS was significantly lower when excluding the socioeconomic factors (P &lt; 0.001).

Conclusion: Some certain socioeconomic factors (i.e., marital status, insurance status, median household income, and residence) play essential roles in predicting survival of non-metastasis breast cancer. We constructed and validated nomograms including socioeconomic factors to provide more comprehensive and realistic survival estimation. Besides, these findings may highlight the importance of developing health-related policies and the necessity of targeted social support-based interventions for those high-risk patients.

Citation Format: Ji P, Gong Y, Hu X, Hong D, Shao Z-M. Association between socioeconomic factors at diagnosis and survival in non-metastatic breast cancer: A population-based study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-09-09.

Abstract P2-08-36: Comparing prognostic performance of different lymph node staging systems among patients with breast cancer

Background: Metastatic regional lymph nodes (LN) is a strong predictor of worse long-term outcome after resection of breast cancer. This study aimed to compare the prognostic performance of American Joint Committee on Cancer (AJCC) N stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), number of removed lymph nodes (NRLNs), and number of negative lymph nodes (NNLNs) in breast cancer patients.

Methods: All of the breast cancer patients who underwent surgery between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. Restricted cubic spline functions were used to characterize the association between continuous variables and the risk of death and determine the optimal cut-off points. The Cox proportional hazards models were constructed, and the relative discriminative abilities of the different LN staging systems were assessed using the Akaike's Information Criterion (AIC) and the Harrell's concordance index (C-index).

Results: A total of 264,096 breast cancer patients were enrolled, and 177,598 (67.2%) had no lymph node metastasis, whereas 86,498 (32.8%) had lymph node metastasis. 187,785 (71.1%) patients had a limited number of LNs harvested (NRLN &lt;10). The median follow-up time was 73 months, and the 8-year overall survival (OS) and breast cancer-specific survival (BCSS) were 82.6% and 90.4%, respectively. LNR, LODDS, NRLNs, and NNLNs were all nonlinearly associated with OS and BCSS. Patients with metastatic LN had an increased risk of OS (hazards ratio: 2.32, 95% confidence interval: 2.27–2.37; P &lt; 0.001) and BCSS (hazards ratio: 4.53, 95% confidence interval: 4.40–4.66; P &lt; 0.001). When LNR was equal to 0 or 1, there was a heterogeneity of outcomes, and LODDS still yielded informative values compared to LNR. Among the entire cohort, LNR modeled as a continuous variable had a somewhat better prognostic performance (AIC: 923231.4 and C-index: 0.722 for OS; AIC: 482962.3 and C-index: 0.817 for BCSS) than any of other LN staging systems. However, a model with AJCC N stage showed the best fit in patients with a limited number of LNs harvested (AIC: 501321.8 and C-index: 0.699 for OS; AIC: 212605.6 and C-index: 0.809 for BCSS). When assessed among patients with metastatic LN, LODDS outperformed other staging systems including AJCC N stage, LNR, NRLNs and NNLNs, whenever assessed using continuous (AIC: 428626.2 and C index: 0.728 for OS; AIC: 296886.8 and C index: 0.770 for BCSS) or categorical (AIC: 429527.5 and C index: 0.722 for OS; AIC: 297796.6 and C index: 0.762 for BCSS) cutoff values.

Conclusions: Although LNR assessed as a continuous variable was the most potent method to stratify patients regardless of LN status, the prognostic superiority of LNR is confounded by a limited LN harvest. LODDS was a better and more powerful predictor of survival when patients were LN positive, especially among those patients with either very low or high LNR.

Citation Format: Gong Y, Ji P, Jiang Y-Z, Hu X, Shao Z-M. Comparing prognostic performance of different lymph node staging systems among patients with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-36.

Molecular cloning and functional characterization of porcine 2',5'-oligoadenylate synthetase 1b and its effect on infection with porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome virus (PRRSV) has previously been shown to increase porcine 2'-5'-oligoadenylate synthase (OAS) 1a expression, but the specific role of porcine OAS1b (pOAS1b) in PRRSV replication remains unknown. In this study, we conducted sequence analysis of the porcine OAS1b gene and studied the effects of its overexpression or silencing on PRRSV replication. OAS1b, localized mainly in the cytoplasm, was found to contain conserved protein domains, such as the P-Loop and D-Box, indicating that its nucleotidyl transferase activity was complete and the antiviral effect depended on ribonuclease L (RNase L). OAS1b overexpression inhibited PRRSV replication, whereas small-interfering-RNA silencing of OAS1b resulted in increased virus titers. Additionally, OAS1b promoted expression of interferons as well as interferon-β promoter activity. These results lay the theoretical foundation for the development of new anti-PRRSV strategies.

Does audiovisual distraction reduce dental anxiety in children under local anesthesia? A systematic review and meta-analysis

OBJECTIVES

To perform a systematic review and meta-analysis on the effects of audiovisual distraction on reducing dental anxiety in children during dental treatment under local anesthesia.

METHODS

The authors identified eligible reports published through August 2017 by searching PubMed, EMBASE, and Cochrane Central Register of Controlled Trials. Clinical trials that reported the effects of audiovisual distraction on children's physiological measures, self-reports, and behavior rating scales during dental treatment met the minimum inclusion requirements. The authors extracted data and performed a meta-analysis of appropriate articles.

RESULTS

Nine eligible trials were included and qualitatively analyzed; some of these trials were also quantitatively analyzed. Among the physiological measures, heart rate or pulse rate was significantly lower (p = .01) in children subjected to audiovisual distraction during dental treatment under local anesthesia than in those who were not; a significant difference in oxygen saturation was not observed. The majority of the studies using self-reports and behavior rating scales suggested that audiovisual distraction was beneficial in reducing anxiety perception and improving children's cooperation during dental treatment.

CONCLUSION

The audiovisual distraction approach effectively reduces dental anxiety among children. Therefore, we suggest the use of audiovisual distraction when children need dental treatment under local anesthesia.

Trigger factor assisted self-assembly of canine parvovirus VP2 protein into virus-like particles in Escherichia coli with high immunogenicity

Canine parvovirus (CPV) has been considered to be an important pathogen, which can cause acute infectious disease in canids. Although current vaccines are effective in preventing CPV infection, safety problems still remain unsolved. In this study, a subunit vaccine against CPV based on virus-like particles (VLPs) with good safety and immunogenicity is reported. Soluble CPV VP2 protein was produced by co-expression of chaperone trigger factor (Tf16) in Escherichia coli (E.coli), and assembled into CPV VLPs which could be affected by NaCl and pH. At 250 mM NaCl pH 8.0, the VLPs co-expressed with Tf16 had similar size (25 nm) and shape with the authentic virus capsid under the transmission electron microscopy (TEM), which is also in accordance with the dynamic light scattering (DLS) data. Immunization with these particles could induce high-titer hemagglutination inhibition (1:12288) and neutralizing antibodies (1:6144) in guinea pigs. Splenic cells of them could secrete IFN-γ and IL-4 after stimulation by CPV. Thus, the VLPs produced by the new approach with high yield and immunogenicity could be a potential candidate for CPV vaccine.