TRPV1+ neurons alter Staphylococcus aureus skin infection outcomes by affecting macrophage polarization and neutrophil recruitment.

BACKGROUND: The interaction between the nervous system and the immune system can affect the outcome of a bacterial infection. Staphylococcus aureus skin infection is a common infectious disease, and elucidating the relationship between the nervous system and immune system may help to improve treatment strategies. RESULTS: In this study, we found that the local release of calcitonin gene-related peptide (CGRP) increased during S. aureus skin infection, and S. aureus could promote the release of CGRP from transient receptor potential cation channel subfamily V member 1 (TRPV1+) neurons in vitro. The existence of TRPV1+ neurons inhibited the recruitment of neutrophils to the infected region and regulated the polarization of macrophages toward M2 while inhibiting polarization toward M1. This reduces the level of inflammation in the infected area, which aggravates the local infection. Furthermore, this study demonstrates that TRPV1 may be a target for the treatment of S. aureus skin infections and that botulinum neurotoxin A (BoNT/A) and BIBN4096 may reverse the inhibited inflammatory effect of CGRP, making them potential therapeutics for the treatment of skin infection in S. aureus. CONCLUSIONS: In S. aureus skin infection, TRPV1+ neurons inhibit neutrophil recruitment and regulate macrophage polarization by releasing CGRP. BoNT/A and BIBN4096 may be potential therapeutic agents for S. aureus skin infection.

The Wnt/ß-catenin signaling pathway inhibits osteoporosis by regulating the expression of TERT: an in vivo and in vitro study.

Our study was performed to investigate whether the Wingless and int-1 (Wnt) signaling pathway promotes osteogenic differentiation and inhibits apoptosis in bone marrow mesenchymal stem cells (BMSCs) by regulating telomerase reverse transcriptase (TERT) expression. An in vivo model of osteoporosis (OP) in C57BL/6J mice by bilateral ovariectomy (OVX) and an in vitro model of H2O2-induced BMSCs were established separately. Western blotting was used to detect the expression of the pathway-related proteins TERT, ß-catenin, and phosphorylated-glycogen synthase kinase-3beta (p-GSK3ß)/GSK3ß, the osteogenic-related markers osteopontin (OPN), bone morphogenetic protein 2 (BMP2), and runt-related transcription factor 2 (Runx2), and the apoptosis-related indicators B-cell lymphoma-2 (Bcl-2) and BAX. Osteoblastic phenotypes were also evaluated by alkaline phosphatase (ALP) staining and serum ALP activity assays. Osteogenic differentiation phenotypes in mice were verified by H&E staining, micro-CT, and parameter analysis of the femur. Western blotting results showed that the expression of the pathway-related proteins TERT, ß-catenin, p-GSK3ß/GSK3ß was reduced in OVX mice and H2O2-induced BMSCs, accompanied by downregulated protein expression of osteogenic-related markers and antiapoptotic indicators and upregulated protein expression of apoptotic proteins compared to those in the control group. Mechanistic studies showed that the activation of Wnt signaling pathway in BMSCs promoted ß-catenin translocation to the nucleus, as verified by immunofluorescence and facilitated colocalization between ß-catenin and TERT, as verified by double-labeling immunofluorescence, thereby promoting osteogenic differentiation and reducing apoptosis. In summary, our experiments confirmed that the GSK3ß/ß-catenin/TERT pathway could regulate the osteogenic differentiation and apoptosis of BMSCs and that TERT might be a promising target for the future treatment of osteoporosis.

Anti-Postmenopausal osteoporosis effects of Isopsoralen: A bioinformatics-integrated experimental study.

Isopsoralen (IPRN), which comes from the fruit of Psoralea corylifolia, has been identified as a kind of phytoestrogen and has been proven to be effective for the treatment of osteoporosis (OP). However, the mechanisms underlying IPRN's anti-OP effects, especially the anti-postmenopausal osteoporosis (PMOP) effects, remain indistinct. Thus, this study aimed to investigate the effects and mechanisms of IPRN's anti-PMOP activity. In this study, the bioinformatics results predicted that IPRN could resist PMOP by targeting EGFR, AKT1, SRC, CCND1, ESR1 (ER-α), AR, PGR, BRCA1, PTGS2, and IGF1R. An ovariectomized (OVX) mice model and a H2 O2 -induced bone marrow mesenchyml stem cells (BMSCs) model confirmed that IPRN could inhibit the bone loss induced by OVX in mice and promote the osteogenic differentiation in H2 O2 -induced BMSCs by inhibiting oxidative stress and apoptosis. Moreover, IPRN could significantly produce the above effects by upregulating ESR1. IPRN might be a therapeutic agent for PMOP by acting as an estrogen replacement agent and a natural antioxidant.

Patient-Reported Outcome on Quality of Life and Pain after Revision Arthroplasty for Periprosthetic Joint Infection: A Cross-Sectional Study.

This study aims to explore the quality of life (QOL) and pain after revision surgery for periprosthetic joint infection (PJI) based on patients' reported outcomes. A cross-sectional questionnaire survey was conducted and 137 valid responses were included (response rate 64.0%). A total of 42 patients underwent debridement with implant retention (DAIR), 31 underwent one-stage revision, and 64 underwent two-stage revision. The average overall SF-36 score was 70.3. The DAIR group had significantly higher SF-36 than the two-stage revision group (p = 0.01). There was no significant difference between the one-stage revision group and the other two groups. A total of 74.5% of patients reported pain with an average McGill Pain Questionnaire (MPQ) score of 8.6. There was no significant difference in the MPQ scores among the three groups. Simple linear regression analyses demonstrated that higher preoperative PMN%, VAS, and shorter hospital stay were associated with pain (adjusted R2 = 4%, p = 0.020; adjusted R2 = 2.1%, p = 0.048; adjusted R2 = 2.1%, p = 0.049; respectively). We concluded that the overall QOL of patients after revision surgery for PJI is generally satisfactory. Persistent pain is prevalent, but the severity was mostly mild. Preoperative PMN%, VAS, and hospital stay were associated with postoperative pain.

Analysis of Community Composition of Bacterioplankton in Changle Seawater in China by Illumina Sequencing Combined with Bacteria Culture.

OBJECTIVES: To characterize the abundance and relative composition of seawater bacterioplankton communities in Changle city using Illumina MiSeq sequencing and bacterial culture techniques. METHODS: Seawater samples and physicochemical factors were collected from the coastal zone of Changle city on 8 September 2019. Nineteen filter membranes were obtained after using a suction filtration system. We randomly selected eight samples for total seawater bacteria (SWDNA group) sequencing and three samples for active seawater bacteria (SWRNA group) sequencing by Illumina MiSeq. The remaining eight samples were used for bacterial culture and identification. Alpha diversity including species coverage (Coverage), species diversity (Shannon-Wiener and Simpson index), richness estimators (Chao1), and abundance-based richness estimation (ACE) were calculated to assess biodiversity of seawater bacterioplankton. Beta diversity was used to evaluate the differences between samples. The species abundance differences were determined using the Wilcoxon rank-sum test. Statistical analyses were performed in R environment. RESULTS: The Alpha diversity in the SWDNA group in each index was ACE 3206.99, Chao1 2615.12, Shannon 4.64, Simpson 0.05, and coverage 0.97; the corresponding index was ACE 1199.55, Chao1 934.75, Shannon 3.49, Simpson 0.09, and coverage 0.99. The sequencing results of seawater bacterial genes in the coastal waters of Changle city showed that the phyla of high-abundance bacteria of both the SWDNA and SWRNA groups included Cyanobacteria, Proteobacteria, and Bacteroidetes. The main classes included Oxyphotobacteria, Alphaproteobacteria, and Gammaproteobacteria. The main genera included Synechococcus CC9902, Chloroplast, and Cyanobium_PCC-6307. Beta diversity analysis showed a significant difference between the SWDNA and SWRNA groups (P < 0.05). The species abundance differences between SWDNA and SWRNA groups after Wilcoxon rank-sum test showed that, at the phylum level, Actinomycetes was more abundant in SWDNA group (9.17 vs 1.02%, P < 0.05); at the class level, Actinomycetes (δ- Proteus) was more abundant in SWDNA group (9.47% vs 1.01%, P < 0.05); and at the genus level, Chloroplast was more abundant in SWRNA group (13.07% vs 44.57%, P < 0.05). Nine species and 53 colonies were found by bacterial culture: 20 strains of Vibrio (37.74%), 22 strains of Enterobacter (41.51%), and 11 strains of non-fermentative bacteria (20.75%). CONCLUSION: Illumi MiSeq sequencing of seawater bacteria revealed that the total bacterial community groups and the active bacterial community groups mainly comprised Cyanobacteria, Proteobacteria, and Bacteroides at the phylum level; Oxyphotobacteria, α-Proteobacteria, and γ-Proteobacteria at the class level; with Synechococcus_CC9902, Chloroplast, and Cyanobium_PCC-6307 comprising the predominant genera. Exploring the composition and differences of seawater bacteria assists understanding regarding the biodiversity and the infections related to seawater bacteria along the coast of the Changle, provides information that will aid in the diagnosis and treatment of such infections.

Bone protein analysis via label-free quantitative proteomics in patients with periprosthetic joint infection.

Periprosthetic joint infection (PJI) is a catastrophic complication of arthroplasty. The treatment of PJI often requires multiple operations and long-term use of antibiotics, making PJI a substantial health and economic burden for patients. Therefore, there is an urgent need to elucidate the pathological mechanism of PJI to explore new therapeutic methods. This study aimed to explore proteomics changes in bone tissue around the prosthesis during PJI development, to explain the pathological mechanism and to provide new treatment ideas. Ten patients who underwent revision surgery at our institution were included: 5 patients with Staphylococcus aureus PJI and 5 patients with aseptic failure. The proteomics changes in bone tissues after PJI were investigated by label-free quantitative proteomics, and the pathways affected by the differential proteins were analyzed by GO annotation, GO enrichment analysis, KEGG enrichment analysis and protein-protein interaction network analysis. We identified 435 differentially expressed proteins (DEPs), with 213 upregulated and 222 downregulated proteins. Analysis revealed activation of immune-related pathways, such as complement and coagulation cascades, phagocytosis, and neutrophil activation, and inhibition of energy metabolism pathways represented by the TCA cycle. We also observed an altered balance between osteoblasts and osteoclasts during S. aureus PJI. We hope that these processes will reveal new treatment ideas. SIGNIFICANCE: PJI is a catastrophic complication of arthroplasty. When infection occurs, bacteria may invade periprosthetic bone tissue to escape immunity and cause damage. So far, only few studies focused on the changes of proteomics associated to PJI. This is the first study to describe the proteomics changes of periprosthetic bone tissue of patients with PJI. We found that the pathological process of S. aureus PJI mainly involves activation of the immune system, decreased energy metabolism, and an altered balance of osteoblasts and osteoclasts.

Destination Joint Spacers: A Similar Infection-Relief Rate But Higher Complication Rate Compared with Two-Stage Revision.

OBJECTIVE: To evaluated the clinical outcomes of periprosthetic joint infection (PJI) patients with destination joint spacer compared with that of two-stage revision. METHODS: From January 2006 to December 2017, data of PJI patients who underwent implantation with antibiotic-impregnated cement spacers in our center due to chronic PJI were collected retrospectively. The diagnosis of PJI was based on the American Society for Musculoskeletal Infection (MSIS) criteria for PJI. One of the following must be met for diagnosis of PJI: a sinus tract communicating with the prosthesis; a pathogenis isolated by culture from two separate tissue or fluid samples obtained from the affected prosthetic joint; four of the following six criteria exist: (i) elevated ESR and CRP; (ii) elevate dsynovial fluid white blood cell (WBC) count; (iii) elevated synovial fluid neutrophil percentage (PMN%); (iv) presence of purulence in the affected joint; (v) isolation of a microorganism in one periprosthetic tissue or fluid culture; (vi) more than five neutrophilsper high-power fields in five high-power fields observed from histological analysis of periprosthetic tissue at ×400 magnification. Age, sex, body mass index (BMI), and laboratory test results were recorded. All patients were followed up regularly after surgery, the infection-relief rates were recorded, Harris hip score (HHS) and knee society score (KSS) were used for functional evaluation, a Doppler ultrasonography of the lower limb veins was performed for complication evaluation. The infection-relief rates and complications were compared between destination joint spacer group and two-stage revision group. RESULTS: A total of 62 patients who were diagnosed with chronic PJI were enrolled, with an age of 65.13 ± 9.94 (39-88) years. There were 21 cases in the destination joint spacer group and 41 cases in the temporary spacer group, namely, two-stage revision group (reimplantation of prosthesis after infection relief). The Charlson comorbidity index (CCI) in the destination joint spacer group was higher than that in the temporary spacer group, and this might be the primary reason for joint spacer retainment. As for infection-relief rate, there were three cases of recurrent infection (14.29%) in the destination joint spacer group and four cases of recurrent infection (9.76%) in the two-stage revision group, there were no significant differences with regard to infection-relief rate. Moreover, there two patients who suffered from spacer fractures, three cases of dislocation, one case of a periarticular fracture, and three cases of deep venous thrombosis in destination joint spacer group, while there was only one case of periprosthetic hip joint fracture, one case of dislocation, and one patient suffered from deep venous thrombosis of the lower extremity in two-stage revision. The incidence of complications in the destination joint spacer group was higher than that of two-stage revision. CONCLUSIONS: In summary, the present work showed that a destination joint spacer might be provided as a last resort for certain PJI patients due to similar infection-relief rate compared with two-stage revision.

Rare Occurrence of Acute Hematogenous Periprosthetic Joint Infection Due to Fusobacterium Nucleatum in the Background of a Dental Procedure: A Case Report.

OBJECTIVE: Fusobacterium nucleatum is an anaerobic gram-negative bacilli that is one of the oral and other mucosal surface microbiota. It involves a wide range of human diseases and was first found in periodontal diseases, but reports of bone-related infections caused by F. nucleatum are rare, especially periprosthetic joint infections (PJI). METHODS: Here, we present the first case of acute hematogenous PJI of the hip joint caused by F. nucleatum, and debridement, antibiotics, and implant retention (DAIR) was performed. RESULTS: The patient was successfully treated with DAIR, identification of isolates by metagenomics next-generation sequencing was confirmed by polymerase chain reaction. CONCLUSIONS: For stable acute hematogenous PJI after hip replacement, quick and accurate diagnosis, the identification of pathogenic microorganisms, and the use of DAIR combined with sufficient sensitive antibiotics have a certain clinical effect and can achieve the purpose of both preserving the prosthesis and infection control.

Cemented prosthesis as spacer for two-stage revision of infected hip prostheses: a similar infection remission rate and a lower complication rate.

AIMS: To explore the effect of different types of articulating antibiotic-loaded cement spacers in two-stage revision for chronic hip prosthetic joint infection (PJI). METHODS: A retrospective cohort study was performed involving 36 chronic PJI patients treated with different types of articulating antibiotic-loaded cement spacers between January 2014 and December 2017. The incidence of complications and the therapeutic effects of different types of antibiotic-loaded articulating cement spacers were compared. RESULTS: A total of 36 patients with chronic hip PJI were included. Of these, 13 patients were treated with spacers with Kirschner wires as an endoskeleton (group I), ten patients were treated with spacers with a cemented femoral prosthesis as an endoskeleton (group II), and 13 patients were treated with cemented femoral prostheses combined with polyethylene sockets as a spacer (group III). All patients were followed for 12 to 60 months, with a mean follow-up period of 26.44 months (SEM 14.09). Infection was controlled in 34 patients (94.44%), and there were no significant differences in the eradication rate among the three groups (p = 0.705), but the risk of complications related to the spacer in group III was significantly lower than that in groups I and II (p = 0.006). CONCLUSION: Articulating antibiotic-loaded cement spacers is effective in the treatment of chronic hip PJI, but we must pay attention to the occurrence of spacer fracture and dislocation, which can lead to poor joint function. The risk of spacer-related mechanical complications is low, and better joint function can be achieved when using cemented femoral prostheses combined with polyethylene sockets as spacers.Cite this article: Bone Joint Res 2020;9(8):484-492.

Detecting the presence of bacteria in low-volume preoperative aspirated synovial fluid by metagenomic next-generation sequencing.

OBJECTIVES: Preoperative diagnosis is important for patients who need revision surgery due to PJI. Microbial culture plays an important role in PJI diagnosis, but the sensitivity of cultures is low when the sample amount is limited or when a patient is treated with antibiotics before sample collection. In this study, metagenomic next-generation sequencing (mNGS) was used to detect bacteria in preoperative puncture synovial fluid samples from patients with suspected PJI, and the preoperative and intraoperative culture results were compared to estimate its diagnostic efficiency. METHODS: From July 2016 to December 2018, patients with suspected PJI who underwent prosthetic joint revision surgery were included, and the results of those who had been tested by preoperative synovial fluid culture and mNGS were obtained. The demographic characteristics, medical history, laboratory test results, culture results, and mNGS results of each patient were recorded. Then, the efficiency of preoperative synovial fluid mNGS was compared to that of synovial fluid culture for diagnosing PJI. RESULTS: A total of 37 patients were included, and 24 patients (25 joints) were diagnosed with PJI. The sensitivity, specificity, and accuracy of preoperative synovial fluid mNGS were 92%, 91.7%, and 83.7%, respectively. The sensitivity, specificity, and accuracy of preoperative synovial fluid culture were 52%, 91.7%, and 43.7%, respectively. CONCLUSIONS: With a low volume of synovia (1 ml), mNGS can be performed with higher sensitivity and specificity compared to synovial culture. Thus, mNGS can be a useful supplemental method to improve diagnostic efficiency during the preoperative period.

Metagenomic next generation sequencing improves diagnosis of prosthetic joint infection by detecting the presence of bacteria in periprosthetic tissues.

OBJECTIVES: The purpose of this study was to explore the role of mNGS in the diagnosis of PJI by detecting the presence of bacteria in periprosthetic tissues. METHODS: Patients who were suspected of PJI and underwent surgery in our center were enrolled. Microbial culture and mNGS were performed on periprosthetic tissues collected intraoperatively. Patient age, body mass index (BMI), laboratory tests, microbial culture and mNGS results were recorded. The diagnostic performance of microbial culture and mNGS in the diagnosis of PJI was compared. RESULTS: A total of 44 patients were included. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of periprosthetic tissue microbial culture in the diagnosis of PJI were 72.72%, 77.27%, 76.19%, 73.91% and 75%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of periprosthetic tissue mNGS in the diagnosis of PJI were 95.45%, 90.91%, 91.3%, 95.24% and 93.18%, respectively. The sensitivity and specificity of mNGS in the diagnosis of PJI were superior to those of microbial culture. CONCLUSION: Periprosthetic tissue can be used as an alternative to synovial fluid and sonication fluid, as mNGS can improve the diagnosis of PJI. mNGS of the periprosthetic tissues showed higher sensitivity than microbial culture.

Reactivation of Denervated Schwann Cells by Embryonic Spinal Cord Neurons to Promote Axon Regeneration and Remyelination.

In peripheral nerve injuries (PNIs) in which proximal axons do not regenerate quickly enough, significant chronic degeneration of Schwann cells (SCs) can occur at the distal stump of the injured nerve and obstruct regeneration. Cell transplantation can delay the degeneration of SCs, but transplanted cells fail to generate voluntary electrical impulses without downstream signal stimulation from the central nervous system. In this study, we combined cell transplantation and nerve transfer strategies to investigate whether the transplantation of embryonic spinal cord cells could benefit the microenvironment of the distal stump of the injured nerve. The experiment consisted of two stages. In the first-stage surgery, common peroneal nerves were transected, and embryonic day 14 (E14) cells or cell culture medium was transplanted into the distal stump of the CPs. Six months after the first-stage surgery, the transplanted cells were removed, and the nerve segment distal to the transplanted site was used to bridge freshly cut tibial nerves to detect whether the cell-treated graft promoted axon growth. The phenotypic changes and the neurotrophic factor expression pattern of SCs distal to the transplanted site were detected at several time points after cell transplantation and excision. The results showed that at different times after transplantation, the cells could survive and generate neurons. Thus, the neurons play the role of proximal axons to prevent chronic degeneration and fibrosis of SCs. After excision of the transplanted cells, the SCs returned to their dedifferentiated phenotype and upregulated growth-associated gene expression. The ability of SCs to be activated again allowed a favorable microenvironment to be created and enhanced the regeneration and remyelination of proximal axons. Muscle reinnervation was also elevated. This transplantation strategy could provide a treatment option for complex neurological injuries in the clinic.

Intratumoral and peritumoral lymphatic vessel density both correlate with lymph node metastasis in breast cancer.

The status of lymph node involvement is an important prognostic factor for breast cancer. However, the presence of intratumoral lymphatic vessels in primary tumor lesions and the relationship between lymphatic vessel density (LVD) and lymph node metastasis (LNM) have not been firmly established. Therefore, we performed a meta-analysis study to investigate these issues. According to the pre-established inclusion and exclusion criteria, 13 studies, involving 1029 breast cancer patients, were included in this study. Using immunohistochemical staining, intratumoral lymphatic vessels were detected in 40.07% of breast cancer patients (240/599), and peritumoral lymphatics were detected in 77.09% (397/515). All studies demonstrated that peritumoral LVD was higher than intratumoral LVD, with a pooled standard mean difference and 95% confidence interval (95% CI) of 1.75 (1.28 to 2.21). Both intratumoral LVD and peritumoral LVD positively correlated with LNM, with correlation coefficients of 0.14 (95% CI 0.05 to 0.23) and 0.31 (95% CI 0.13 to 0.49), respectively. In summary, our study reports the overall detection rate of intratumoral lymphatics and demonstrates the associations between intratumoral LVD, peritumoral LVD, and LNM in breast cancer. Additionally, controlled studies with a larger number of subjects are needed to establish these relationships.

The relationship of lymphatic vessel density, lymphovascular invasion, and lymph node metastasis in breast cancer: a systematic review and meta-analysis.

Lymph node status is one of the key parameters used for determining the stage of breast cancer progression. The relationship of lymphatic vessel density (LVD), lymphovascular invasion (LVI), and lymph node metastasis (LNM) has not been clearly demonstrated yet. Databases of PubMed, Embase, and Web of Science were searched from inception up to 25 May 2016. Spearman correlation coefficient (r) and 95% confidence interval (CI) were used to determine the relationship within each group. Based on pre-established inclusion criteria, 28 studies involving 2920 breast cancer patients were included in this study. The r values of LVD-LVI, LVD-LNM, and LVI-LNM were 0.45 (95% CI: 0.31 to 0.57), 0.32 (95% CI: 0.23 to 0.40), and 0.24 (95% CI: 0.19 to 0.28), respectively. Compared with intratumoral LVD, peritumoral LVD showed more robust correlation with LVI (r = 0.53, 95% CI: 0.27 to 0.72) and LNM (r = 0.33, 95% CI: 0.18 to 0.46). The patients in LNM positive group presented with higher LVI detection rate of 45.85%, while in LNM negative group with detection rate of 23.85%. The results describe a triangle relationship between LVD, LVI, and LNM in breast cancer. Both LVD and LVI are indicated to be valuable predictors of LNM occurrence. Compared with intratumoral lymphatic vessels, peritumoral lymphatics might be the main disseminate route for breast tumor cells.

[Applied study on clustering of variables around latent components method in wavelength region selection with near-infrared spectroscopy].

The present paper introduced the principle of clustering of variables around latent components method, and used this method in selecting spectrum range of the NIR quantitative analysis models. Taking tobacco samples as experiment materials, we dealed with 107 sample spectra, divided the spectra into 5 clusters, and explained the information reflected by each of these 5 clusters in terms of chemistry. On this basis, we chose the corresponding wavelength range to set up the quantitative models of the total sugar, reducing sugar and nicotine by PLS method. Compared with the model based on the full NIR spectral range, Rtraining of the models based on the chosen spectral range rose from 0.977 1, 0.917 2 and 0.987 4 to 0.995 5, 0.975 1 and 0.994 4; Rtest rose from 0.977 8, 0.941 2 and 0.993 2 to 0.992 7, 0.967 9 and 0.994 0; RMSECV dropped from 1.09, 1.43, 0.14 to 1.05, 1.05 and 0.13, RMSEP dropped from 0.92, 1.17 and 0.16 to 0.39, 0.63 and 0.11 and the D value dropped from 1.274%, 1.972% and 0.829% to 0.711%, 0.843% and 0.768% for the total sugar, reducing sugar and nicotine, respectively. These data indicated that this method can improve the forecasting precision and stability of the model, so offers certain guidance on practical application.