Association between hamstring coactivation during isokinetic quadriceps strength testing and knee cartilage worsening over 24 months

OBJECTIVE

This study aimed to determine longitudinal associations, including sex-specific differences, between greater knee flexor antagonist coactivation and worsening cartilage morphology in knees with or at risk for osteoarthritis (OA).

DESIGN

Baseline measurements were collected at the 60-month visit of a longitudinal osteoarthritis study following community-dwelling participants (MOST). Knee flexor and extensor muscle activity were measured with surface electromyography during a maximal isokinetic knee extension task. MRI analyzed knee cartilage morphology at baseline and 24-month follow-up. Multivariable adjusted logistic regression models were used to assess associations between coactivation level and cartilage morphology worsening.

RESULTS

Analysis of 373 women (mean ± SD age 67.4 ± 7.3 years and BMI 29.7 ± 5.0 kg/m2) and 240 men (66.5 ± 7.8 years and 29.9 ± 4.5 kg/m2) revealed that women had greater medial (P < 0.001), lateral (P < 0.001), and combined (P < 0.001) hamstring coactivation than men. In both sexes, combined hamstring coactivation was associated with patellofemoral cartilage morphology worsening [1.23 (1.02, 1.49)] and to a less significant degree with whole knee cartilage morphology worsening [1.21 (0.98, 1.49)]. In men, greater combined hamstring coactivation was associated with increased risk for whole knee [1.59 (1.06, 2.39)] and patellofemoral [1.38 (1.01, 1.88)] cartilage morphology worsening and point estimates suggested association between medial hamstring coactivation and medial tibiofemoral cartilage morphology worsening. No significant associations were detected between greater hamstring coactivation and cartilage morphology worsening in women.

CONCLUSIONS

These findings suggest a longitudinal relationship between antagonist hamstring coactivation during isokinetic knee extensor testing and worsening of cartilage morphology over 24 months in men with or at risk for knee OA.

POS0094 ALPN-303, AN ENGINEERED DUAL BAFF/APRIL ANTAGONIST, POTENTLY INHIBITS PATHOGENIC LYMPHOCYTE SUBSETS AND FUNCTION IN B-CELL- AND ANTIBODY-RELATED PRECLINICAL MODELS

Background

B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are tumor necrosis factor (TNF) superfamily members that bind TACI (transmembrane activator and CAML interactor), BCMA (B-cell maturation antigen), and/or BAFF-R on B cells and together support B cell development, differentiation, and survival. ALPN-303 is an Fc fusion protein of a human TACI variant TNFR domain engineered by directed evolution1,2. It mediates significantly improved combined BAFF and APRIL inhibition in vitro and enhanced pharmacokinetic and immunomodulatory properties in preclinical studies, as compared to wild-type (WT) TACI-Fc molecules. B-cell targeting therapies like the WT TACI-Fc fusions atacicept and telitacicept have demonstrated promising clinical potential in B cell-related diseases like systemic lupus erythematosus (SLE). ALPN-303, with enhanced inhibitory activity against BAFF and APRIL, has previously been shown to demonstrate promising efficacy in an (NZB/NZW)F1 mouse model of lupus, and may therefore further improve clinical outcomes in such diseases.

Objectives

To further characterize the comparative activity of ALPN-303 versus an Fc matched control, a WT TACI-Fc comparator (telitacicept), and/or a B cell-depleting therapy (anti-mouse CD20 [anti-mCD20] monoclonal antibody [mAb]), in antibody-related preclinical models.

Methods

The functional activity of ALPN-303, as compared to telitacicept or a depleting anti-mCD20 mAb, was evaluated in a sheep red blood cell (SRBC) immunization mouse model. Mice immunized intraperitoneally with SRBC on Study Day 0 were administered 200 µg ALPN-303 or a molar-matched amount (240 µg) of telitacicept on Days 1 and 6 or were treated with 200 µg anti-mCD20 (rat IgG2b) on Day 1. At study termination on Day 15, serum was collected to measure levels of test article and anti-SRBC immunoglobulin (Ig) titers, and spleens and bone marrow (BM) were collected for immunophenotyping by flow cytometry. A study in the inducible bm12 mouse model of lupus was also conducted, with mice treated twice weekly with 200 µg ALPN-303 or a molar-matched dose of Fc control, starting on Day 5 after splenocyte transfer and continuing through Week 13.

Results

ALPN-303 administration rapidly and potently reduced BM plasma cells, splenic germinal center B cells, follicular T helper cells, and plasmablasts in SRBC-immunized mice, often significantly more so than telitacicept and/or anti-mCD20 mAb. ALPN-303 also significantly reduced serum titers of anti-SRBC IgM, IgG1, IgG2a, and IgG2b as compared to all other treatment groups. In the bm12 model, ALPN-303 treatment significantly impacted the same key lymphocyte subsets affected in the SRBC model, and significantly reduced circulating anti-dsDNA antibodies (Figure 1) and total IgA, IgM, IgG1, IgG2b, and IgG3, and inhibited renal IgG deposits (Figure 1).

Figure 1.

ALPN-303 treatment significantly reduces serum autoantibody titers and renal immune complex deposition in the inducible bm12 mouse model of lupus. *p<0.05, **p<0.01, ****p<0.0001 by the Kruskal-Wallis test.

Conclusion

ALPN-303 is an engineered, potent BAFF/APRIL antagonist that continues to consistently demonstrate encouraging immunomodulatory activity and efficacy in vitro and in vivo, as further demonstrated in the SRBC immunization and bm12 lupus models, with superiority to WT TACI-Fc and anti-CD20 comparators. ALPN-303 may thus be an attractive development candidate for the treatment of multiple autoimmune and inflammatory diseases, particularly B cell- and/or autoantibody-related diseases such as SLE, Sjögren’s syndrome, and other connective tissue diseases. A Phase 1 study of ALPN-303 in adult healthy volunteers (NCT05034484) is ongoing.

References

[1]Dillon SR, Evans LS, Lewis KE, et al. Annals of the Rheumatic Diseases 2021;80:21.

[2]Dillon SR, Evans LS, Lewis KE, et al. Arthritis Rheumatol. 2021; 73 (suppl 10).

Disclosure of Interests

Stacey R. Dillon Employee of: Alpine Immune Sciences, Katherine E. Lewis Employee of: Alpine Immune Sciences Inc, Sherri Mudri Employee of: Alpine Immune Sciences Inc, Kayla Kleist Employee of: Alpine Immune Sciences Inc, Luana Griffin Employee of: Alpine Immune Sciences Inc, Lawrence S. Evans Employee of: Alpine Immune Sciences Inc, Janhavi Bhandari Shareholder of: Amgen, Novo Nordisk, Employee of: Alpine Immune Sciences Inc, Logan Garrett Employee of: Alpine Immune Sciences Inc, Michelle A. Seaberg Employee of: Alpine Immune Sciences Inc, NingXin Wang Employee of: Alpine Immune Sciences Inc, Allison Chunyk Employee of: Alpine Immune Sciences Inc, Daniel Ardourel Employee of: Alpine Immune Sciences Inc, LuAnne Hebb Employee of: Alpine Immune Sciences Inc, Martin F. Wolfson Employee of: Alpine Immune Sciences Inc, Mark W. Rixon Employee of: Alpine Immune Sciences Inc, Pamela Holland Employee of: Alpine Immune Sciences Inc, Stanford L. Peng Employee of: Alpine Immune Sciences Inc

[Overlap esophagojejunostomy with multi-mode modifications in totally laparoscopic total gastrectomy: safety and feasibility of 152 cases from a single center]

Objective: Currently, the Overlap anastomosis is one of the most favored reconstruction methods of intracorporeal esophagojejunostomy (EJS). Despite many advantages of the method, it remains some shortcomings to be improved when it comes to the retraction of the esophagus stump, the insertion of the anvil fork of the linear stapler into a "pseudo" lumen, and the closure of the common entry hole. This study aims to investigate the safety and feasibility of a multi-mode modified Overlap anastomosis. Methods: A descriptive case series study was conducted. Medical records of 152 consecutive patients who underwent totally laparoscopic total gastrectomy (TLTG) with our multi-mode modified Overlap EJS method by the same surgical team at our department from February 2017 to June 2020 were retrospectively analyzed. The multi-mode modified Overlap method mainly included (1) After ensuring the safety of tumor resection margin (proximal margin was at least 3 cm from the tumor), the esophagus was partially transected from left to right (with 5-8 mm width esophagus continuation). The specimen was then placed in a plastic bag which was tied up at the mouth using strings with a part of the esophageal wall poking through. Then the plastic bag containing the specimen was transferred to the right lumbar region, while the patient's body position was adjusted so that the abdominal esophagus could be pulled by the gravity of the specimen. (2) Using the "three-direction traction" method. The esophageal lumen was properly exposed, then guided by the gastric tube, the anvil fork was accurately placed into the esophageal lumen for completing the side-to-side EJS. (3) The 3-0 barbed suture was used in the closure of the common entry hole of the stapler from dorsally to ventrally with simple one-layer continuous suture (the stitch going from inside to inside) followed by continuous Lembert's suture (the stitch going from outside to outside). Combined with clinicopathological characteristics, the perioperative outcomes and postoperative complications of the whole group were analyzed and evaluated. Results: The study cohort included 129 men and 23 women, with a mean age of (60.2±9.1) years and a mean body mass index (BMI) of (23.2±3.1) kg/m(2). Of the 152 patients, 23 patients (15.1%) had a history of previous abdominal surgery; dentate line was invaded by tumor in 21 patients (13.8%). The mean length of the proximal resection margin was (3.3±0.3) cm and the postoperative pathological examination indicated negative resection margin tumor. The mean operative time and anastomotic time were (302.1±39.9) minutes and (29.8±5.4) minutes, respectively. The mean estimated blood loss was (87.9±46.4) ml. The mean length of postoperative hospital stay was (12.3±7.3) days. The overall severe postoperative complications (Clavien-Dindo ≥ II) occurred in 22 patients (14.5%). Six cases of pancreatic leakage were successfully recovered by adequate drainage, inhibition of pancreatic exocrine secretion and nutritional support. Ten cases of pneumonia and three cases of abdominal infection were cured with anti-infection and physical therapy. Two patients developed anastomotic leakage postoperatively. One case was caused by excessive tension of the Roux loop of the jejunum and excessive opening on the side of the jejunum after side-to-side anastomosis, and the other case was caused by an accidental intraoperative occurrence of "nasogastric tube stapled to the side-to-side anastomosis". Both of them recovered after conservative treatment including adequate drainage, anti-infection, and adequate nutritional support. One patient underwent immediate open surgery because of Peterson's hernia 7 days after TLTG, and the patient died due to extensive small bowel necrosis. Conclusions: Multi-mode modified overlap method simplifies the operation and reduces the difficulty of EJS. It is a safe and feasible method for EJS.

[Technical details of gastrointestinal reconstruction using linear stapler in totally laparoscopic total gastrectomy]

With the development of instrument, equipment and surgical skills, especially the emergence of a series of high-level medical evidence, the laparoscopic techniques in the field of gastric surgery has been further expanded. Totally laparoscopic total gastrectomy (TLTG) has certain technical difficulties, and more challenges are reflected in the digestive tract reconstruction. The use of linear staplers has reduced the difficulty of digestive tract reconstruction to a certain extent and has strongly promoted the transition from laparoscopic-assisted total gastrectomy to TLTG. However, for TLTG, there are still many details that should be carefully concerned, so as to effectively avoid the surgical pitfalls and ensure the fluency and safety of the procedure. In this article, we discuss the surgical details based on our own experiences, including how to obtain surgical field exposure well, how to manage specific accidents when using linear stapler for esophagojejunostomy, how to prevent intra-abdominal hernias and Roux stasis syndrome, and how to prevent the stapled lines of the esophageal or jejunal stumps from direct contact with aorta.

Heterogeneity of cartilage damage in Kellgren and Lawrence grade 2 and 3 knees: the MOST study

OBJECTIVE

Eligibility for clinical trials in osteoarthritis (OA) is usually limited to Kellgren-Lawrence (KL) grades 2 and 3 knees. Our aim was to describe the prevalence and severity of cartilage damage in KL 2 and 3 knees by compartment and articular subregion.

DESIGN

The Multicenter Osteoarthritis (MOST) study is a cohort study of individuals with or at risk for knee OA. All baseline MRIs with radiographic disease severity KL2 and 3 were included. Knee MRIs were read for cartilage damage in 14 subregions. We determined the frequencies of no, any and widespread full-thickness cartilage damage by knee compartment, and the prevalence of any cartilage damage in 14 articular subregions.

RESULTS

665 knees from 665 participants were included (mean age 63.8 ± 7.9 years, 66.5% women). 372 knees were KL2 and 293 knees were KL3. There was no cartilage damage in 78 (21.0%) medial tibio-femoral joint (TFJ), 157 (42.2%) lateral TFJ and 62 (16.7%) patello-femoral joint (PFJ) compartments of KL2 knees, and 17 (5.8%), 115 (39.3%) and 35 (12.0%) compartments, respectively, of KL3 knees. There was widespread full-thickness damage in 94 (25.3%) medial TFJ, 36 (9.7%) lateral TFJ and 176 (47.3%) PFJ compartments of KL2 knees, and 217 (74.1%), 70 (23.9%) and 104 (35.5%) compartments, respectively, of KL3 knees. The subregions most likely to have any damage were central medial femur (80.5%), medial patella (69.8%) and central medial tibia (69.9).

CONCLUSIONS

KL2 and KL3 knees vary greatly in cartilage morphology. Heterogeneity in the prevalence, severity and location of cartilage damage in in KL2 and 3 knees should be considered when planning disease modifying trials for knee OA.

[Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain]

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multi-modal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

[Analysis of the associations of chemokine receptors expression on circulating Tfh2 and Th2 cells with sIgE level and disease severity in patients with AR]

Objective: To clarify the chemotactic characteristics of type 2 helper T cells (Th2 cells) and type 2 follicular helper T cells (Tfh2 cells) in peripheral blood of patients with allergic rhinitis (AR), and to explore the associations between the chemokine receptors expression and the levels of antigen-specific IgE (sIgE) and the severity of the disease. Methods: The peripheral blood mononuclear cells of 41 patients with AR (20 males and 21 females, aged 35.0 (24.5, 47.0) years) and 42 healthy controls (24 males and 18 females, aged 35.0 (24.8, 46.5) years) treated in Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from April 2017 to February 2018 were isolated. The expressions of chemokine receptor (CCR)2, CCR3, CCR4, CCR5, CCR7, CCR8, chemokine C-X3-C-motif receptor 1 (CX3CR1) and C-X-C motif receptor 4 (CXCR4) in Th2 and Tfh2 cells were explored by fluorescence activated cell sorting (FACs). The relationship between the expression of these chemokine receptors in Th2 cells and Tfh2 cells and the levels of serum sIgE and the scores of visual analogue scale (VAS) was analyzed. Graphpad prism 7.0 software was used for statistical analysis. Results: The significant differences in chemotactic characteristics between Th2 cells and Tfh2 cells in the control group were found: Th2 cells highly expressed chemokine receptors CCR2, CCR3, CCR5, CCR8 and CX3CR1, while Tfh2 cells highly expressed immune cell homing chemokine receptors CCR7 and CXCR4. AR patients, compared to the control, expressed higher levels of CCR2, CCR5 and CX3CR1 on peripheral Th2 cells(all P<0.01). At the same time, the proportion of CCR2⁺and CCR5⁺Th2 cells was positively correlated with VAS score (r value was 0.58 and 0.61, respectively, both P<0.01). In AR patients, higher expression levels of CCR7 on Tfh2 cells were detected (P<0.01), and the proportion of CCR7⁺Tfh2 cells was positively correlated with the level of serum sIgE (r=0.51, P<0.01). Conclusion: The percentage of CCR2⁺ and CCR5⁺ Th2 cells in peripheral of AR patients can reflect the severity of AR to some extent, while the percentage of CCR7⁺ Tfh2 cells is positively correlated with the level of serum sIgE.

Does weight-bearing versus non-weight-bearing pain reflect different pain mechanisms in knee osteoarthritis?: the Multicenter Osteoarthritis Study (MOST)

OBJECTIVE

Knee osteoarthritis (OA) is predominantly characterized by pain with weight-bearing activities. Pain at rest also occurs but the mechanisms for this are not clear. We evaluated the relations of nociceptive signal alterations to weight-bearing and non-weight-bearing pain in knee OA.

DESIGN

We used data from a NIH-funded longitudinal cohort of older adults with or at risk of knee OA. We evaluated quantitative sensory testing (QST) measures (pressure pain threshold (PPT) at patellae and the wrist; mechanical temporal summation (TS); conditioned pain modulation (CPM)). Each WOMAC pain question was dichotomized as having at least moderate pain, and we further categorized them as weight-bearing pain and non-weight-bearing pain. We evaluated the relation of QST measures to each pain outcome using logistic regression, adjusting for potential confounders.

RESULTS

2,749 participants (5,479 knees) were included (mean age 64 ± 11, 57% female). Each SD unit decrease in patellar PPT was associated with greater odds of both weight-bearing pain (OR 1.51 (95% CI 1.27, 1.79)) and non-weight-bearing pain (OR 1.46 (1.20-1.77)), while wrist PPT was associated with greater odds of weight-bearing pain (OR 1.27 (1.15, 1.39)) but only with pain during sitting/lying (OR 1.20 (1.01, 1.43)). TS was significantly associated with greater odds of pain with walking and stairs (OR 1.11 (1.01, 1.23), 1.11 (1.03, 1.20), respectively). CPM was not associated with any pain outcomes.

CONCLUSIONS

Our findings challenge the hypothesis that non-weight-bearing pain may reflect greater pain sensitization and/or inefficient CPM than weight-bearing pain in knee OA, suggesting other mechanisms are likely responsible.

[Clinical analysis of pulmonary nocardiosis associated with bronchiectasis]

Objective: To better understand the clinical characteristics of pulmonary nocardiosis associated with bronchiectasis. Methods: Patients diagnosed as bronchiectasis complicated with pulmonary nocardiosis in 9 tertiary general hospitals in China were enrolled from March 2016 to March 2020, with the record of general data, imaging performance and pathogen. The literature was reviewed. Results: Totally 17 patients were included. There were 12 females and 5 males. The ages ranged from 45 to 79 years, with an average of (63±9) years. There were 15 nonsmokers and 2 smokers, all of whom with chronic course. The clinical manifestations were mostly cough, expectoration, hemoptysis, fever, and dyspnea. The imaging manifestation was bronchiectasis in both lungs, with the most common involvement in the left lower lung, right middle lobe and left lingual lobe. Sputum cultures were positive in 10 cases, bronchoalveolar lavage fluid (BALF) cultures were positive in 6 cases, and next generation gene sequencings were positive in 4 cases, including 2 cases of Nocardia gelsenkii, 2 cases of Nocardia abscess, 2 cases of Nocardia stellate, 1 case of Nocardia mexicana, 1 case of Nocardia otitis caviae, and 9 cases of undetermined Nocardia. There were 3 cases of Klebsiella pneumoniae, 2 cases of Pseudomonas aeruginosa and 2 cases of Aspergillus. The symptoms and imaging of all patients were improved after anti Nocardia therapy. Conclusions: Bronchiectasis combined with nocardiosis is more common in middle-aged and elderly women without smoking, which is similar to the clinical manifestations of Lady Windermere syndrome. Bronchiectasis often involves the left lower lobe, right middle lobe and left lingual lobe. Nocardia infection might further precipitate the initiation and progression of bronchiectasis.

[Prevalence of chronic respiratory symptoms and dyspnea and related factors in residents in China]

Objective: To understand the prevalence of chronic cough, chronic expectoration and dyspnea and related factors in residents aged ≥40 years in China, and provide basic data for the prevention and control of chronic respiratory diseases. Methods: Data were from 2014-2015 chronic obstructive pulmonary disease surveillance in China. The information about chronic respiratory symptoms were collected by face-to-face interview. The prevalence rates of chronic cough, chronic expectoration, dyspnea and chronic respiratory symptoms and their 95%CI were estimated with complex sampling weights. Results: A total of 75 082 subjects were included in the analysis. The prevalence rates of chronic cough, chronic expectoration, dyspnea and chronic respiratory symptoms in the Chinese aged ≥40 years were 3.75% (95%CI: 3.38%-4.11%), 5.83% (95%CI: 5.40%-6.26%), 2.45% (95%CI: 2.02%-2.87%) and 8.93% (95%CI: 8.25%-9.62%), respectively. The prevalence rates of chronic cough, chronic expectoration, dyspnea and chronic respiratory symptoms in patients with chronic respiratory diseases were relatively higher, which were 10.27%, 13.85%, 6.43%, 20.72% respectively. Multivariate logistic regression analysis showed that age, region, education level, occupation, BMI, family history of respiratory diseases, history of severe respiratory infections in childhood, exposure to dust or chemicals in workplace and smoking status affected the prevalence of chronic cough, chronic expectoration and dyspnea. The prevalence of the three types of chronic respiratory symptoms increased significantly with age, which were higher in western region, smokers and underweight/obese subjects. The three prevalence rates mentioned above were higher in those with a history of severe respiratory infection in childhood, those exposed to biomass fuel in household, and those exposed to dust or chemicals in workplace. Conclusions: The prevalence rate of chronic respiratory symptoms was high in residents aged ≥40 years in China. Many factors affected the prevalence of chronic respiratory symptoms. Comprehensive prevention and control measures targeting risk factors should be taken to reduce the burden of chronic respiratory diseases.

[Incidence and risk factors of metabolic syndrome in rural community population on islands in Zhejiang province]

Objective: To estimate the incidence of metabolic syndrome and explore possible risk factors for metabolic syndrome in adults of rural communities in Yuhuan county, Zhejiang province, China. Methods: During June-December, 2018, a follow-up survey was conducted in participants without metabolic syndrome at baseline survey in 2012 to obtain the information collected in questionnaire survey, anthropometric data and laboratory data. The incidence of metabolic syndrome in the participants was estimated, and Logistic regression model was used to explore the risk factors, adjusted risk ratio (aRR) and 95%CI. Results: Among 3 162 participants, 522 new metabolic syndrome cases were identified. The 6-year cumulative incidence rate of metabolic syndrome was 16.5%, and the cumulative incidence rate was higher in women (20.6%) than that in men (12.3%, P<0.001). Those incidence rates were higher in those in jobless, smoking or drinking groups. Being women (aRR=1.96, 95%CI: 1.50-2.58) and family history of hypertension (aRR=1.31, 95%CI: 1.04-1.63) were independent risk factors for metabolic syndrome. Conclusion: The follow up indicated that the incidence of metabolic syndrome was relatively high in rural adults on islands in Zhejiang, and women or those with family history of hypertension were more likely to have metabolic syndrome.

Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain

Abstract

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multimodal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

Use of real-time artificial intelligence in detection of abnormal image patterns in standard sonographic reference planes in screening for fetal intracranial malformations

OBJECTIVES

To develop and validate an artificial intelligence system, the Prenatal ultrasound diagnosis Artificial Intelligence Conduct System (PAICS), to detect different patterns of fetal intracranial abnormality in standard sonographic reference planes for screening for congenital central nervous system (CNS) malformations.

METHODS

Neurosonographic images from normal fetuses and fetuses with CNS malformations at 18-40 gestational weeks were retrieved from the databases of two tertiary hospitals in China and assigned randomly (ratio, 8:1:1) to training, fine-tuning and internal validation datasets to develop and evaluate the PAICS. The system was built based on a real-time convolutional neural network (CNN) algorithm, You Only Look Once, version 3 (YOLOv3). An image dataset from a third tertiary hospital was used to further validate, externally, the performance of the PAICS and to compare its performance with that of sonologists with different levels of expertise. Furthermore, a prospective video dataset was employed to evaluate the performance of the PAICS in a real-time scan scenario. The diagnostic accuracy, sensitivity, specificity and area under the receiver-operating-characteristics curve (AUC) were calculated to assess the performance of the PAICS and to compare this with the performance of sonologists with different levels of experience.

RESULTS

In total, 43 890 images from 16 297 pregnancies and 169 videos from 166 pregnancies were used to develop and validate the PAICS. The system achieved excellent performance in identifying 10 types of intracranial image pattern, with macro- and microaverage AUCs, respectively, of 0.933 (95% CI, 0.798-1.000) and 0.977 (95% CI, 0.970-0.985) for the internal validation image dataset, 0.902 (95% CI, 0.816-0.989) and 0.898 (95% CI, 0.885-0.911) for the external validation image dataset and 0.969 (95% CI, 0.886-1.000) and 0.981 (95% CI, 0.974-0.988) in the real-time scan setting. The performance of the PAICS was comparable to that of expert sonologists in terms of macro- and microaverage accuracy (P = 0.863 and P = 0.775, respectively), sensitivity (P = 0.883, P = 0.846) and AUC (P = 0.891, P = 0.788), but required significantly less time (0.025 s per image for PAICS vs 4.4 s for experts, P < 0.001).

CONCLUSIONS

Both in the image dataset and in the real-time scan setting, the PAICS achieved excellent diagnostic performance for various fetal CNS abnormalities. Its performance was comparable to that of experts, but it required less time. A CNN algorithm can be trained to detect fetal CNS abnormalities. The PAICS has the potential to be an effective and efficient tool in screening for fetal CNS malformations in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

A repeating fast radio burst source in a globular cluster

Fast radio bursts (FRBs) are flashes of unknown physical origin¹. The majority of FRBs have been seen only once, although some are known to generate multiple flashes^2,3. Many models invoke magnetically powered neutron stars (magnetars) as the source of the emission^4,5. Recently, the discovery⁶ of another repeater (FRB 20200120E) was announced, in the direction of the nearby galaxy M81, with four potential counterparts at other wavelengths⁶. Here we report observations that localized the FRB to a globular cluster associated with M81, where it is 2 parsecs away from the optical centre of the cluster. Globular clusters host old stellar populations, challenging FRB models that invoke young magnetars formed in a core-collapse supernova. We propose instead that FRB 20200120E originates from a highly magnetized neutron star formed either through the accretion-induced collapse of a white dwarf, or the merger of compact stars in a binary system⁷. Compact binaries are efficiently formed inside globular clusters, so a model invoking them could also be responsible for the observed bursts.

[Changes in the structure of intestinal mucosal flora in colorectal cancer patients]

OBJECTIVE

To investigate the changes in bacterial flora in fecal samples, at the tumor loci and in adjacent mucosa in patients with colorectal cancer (CRC).

METHODS

We collected fecal samples from 13 patients with CRC and 20 healthy individuals and tumor and adjacent mucosa samples from 6 CRC patients. The differences in bacterial composition between the fecal and mucosa samples were analyzed with 16S rDNA sequencing and bioinformatics methods. We also detected the total number of bacteria in the feces using flow cytometry, isolated and identified the microorganisms in the fecal and mucosa samples using common bacterial culture media. We further tested the effects of 7 isolated bacterial strains on apoptosis of 3 CRC cell lines using lactate dehydrogenase detection kit.

RESULTS

The bacterial α-diversity in the feces of healthy individuals and in adjacent mucosa of CRC patients was significantly higher than that in the feces and tumor mucosa in CRC patients (P < 0.05). Lactobacillaceae is a specific bacteria in the feces, while Escherichia, Enterococcus, and Fusobacterium are specific bacteria in tumor mucosa of CRC patients as compared with healthy individuals. Cell experiment with3 CRC cell lines showed that Bacteroides fragilis isolated from the tumor mucosa of CRC patients produced significant inhibitory effects on cell proliferation (P < 0.0001), while the isolated strain Fusobacterium nucleatum obviously promoted the proliferation of the cell lines (P < 0.001).

CONCLUSION

The bacterial flora in the feces, tumor mucosa and adjacent mucosa of CRC patients is significantly different from that in the feces of healthy individuals, and the fecal flora of CRC patients can not represent the specific flora of the tumor mucosa. Inhibition of F. nucleatum colonization in the tumor mucosa and promoting B. fragilis colonization may prove beneficial for CRC treatment.

[Association between obesity with the diversity and genus of gut microbiota in school-aged children]

Objective: To analyze the diversity differences of gut microbiota between school-aged obese children and normal-weight children and identify the characteristic flora in obese children to provide some evidence for the subsequent study of the following study-related mechanisms and the prevention and treatment of obesity in school-aged children. Methods: This study was based on a cohort established in a primary school in Jiading district, Shanghai, 2016. Sixty-three children, including 43 boys and 20 girls, who were obese during the three years from 2016 to 2018, were enrolled in the obesity group. Among children who were average weight for three years, a total of 63 were selected as the control group, with matching with the obese ones in a 1 to 1 way according to age, sex and class. The primary characteristics, diet status, breastfeeding, and other information of children were collected by questionnaire. Fecal samples of participants in both groups were collected, and 16S rDNA sequencing was performed. Operable taxon units clustering according to 97% similarity and species annotation were based on the quality-optimized sequences. The difference in the diversity and genius of gut microbiota among children in the obesity and control groups were analyzed. The α diversity indices, including Ace, Chao1, Shannon, and Simpson index, were calculated. The β diversity was presented based on unweighted Unifrac distance and weighted Unifrac space by principal coordinate analysis. The differences in β diversity between the two groups were compared by similarity analysis (ANOSIM).The differences in genus distribution between the two groups were selected by STAMP software. The association of obesity with the α diversity and genus with significant differences were analyzed by the generalized linear model (GLM). Results: The Ace and Chao1 index in the obesity group was significantly lower than those in the control group (The P values were 0.026 and 0.039, respectively). There was no significant difference in Shannon and Simpson index between the two groups (The P values were 0.879 and 0.922, respectively). The results of ANOSIM showed differences in gut microbiota between the two groups (R>0), but the group contribution was not significant (unweighted Unifrac distance: R=0.006, P=0.223; weighted Unifrac distance: R=0.010, P=0.134). Among the obese group, the relative abundance of Prevotella and Sarcina was highest in the endemic genus. The STAMP results showed that the relative lots of 15 genera were significantly different between the two groups (P<0.05). The results of GLM showed that, compared with the control group, the obesity group had a lower level of the relative abundance in Akkermansia muciniphila, while a higher level in Coprococcus_3, Ruminococcus, Agathobacter and Collinsella. After stratification by sex, the Chao1 index was also lower in the obese boys than that in the normal-weight boys. However, the obese girls only had a higher level in Coprococcus_3 than the ordinary weight girls. Conclusions: Compared with children with average weight, obese children had lower α diversity of gut microbiota and lower relative abundance of dominant probiotics but had a higher relative lot of genus associated with metabolic disorders, inflammation promotion, and metabolism rate reduction.

Novel role of estrogen receptor-α on regulating chondrocyte phenotype and response to mechanical loading

OBJECTIVE

In knee cartilage from patients with osteoarthritis (OA), both preserved cartilage and damaged cartilage are observed. In this study, we aim to compare preserved with damaged cartilage to identify the molecule(s) that may be responsible for the mechanical loading-induced differences within cartilage degradation.

METHODS

Preserved and damaged cartilage were harvested from the same OA knee joint. RNA Sequencing was performed to examine the transcriptomic differences between preserved and damaged cartilage cells. Estrogen receptor-α (ERα) was identified, and its function of was tested through gene knockin and knockout. The role of ERα in mediating chondrocyte response to mechanical loading was examined via compression of chondrocyte-laded hydrogel in a strain-controlled manner. Findings from the studies on human samples were verified in animal models.

RESULTS

Level of estrogen receptor α (ERα) was significantly reduced in damaged cartilage compared to preserved cartilage, which were observed in both human and mice samples. Knockdown of ESR1, the gene encoding ERα, resulted in an upregulation of senescence- and OA-relevant markers in chondrocytes. Conversely, knockin of ESR1 partially reversed the osteoarthritic and senescent phenotype of OA chondrocytes. Using a three-dimensional (3D) culture model, we demonstrated that mechanical overload significantly suppressed ERα level in chondrocytes with concomitant upregulation of osteoarthritic phenotype. When ESR1 expression was suppressed, mechanical loading enhanced hypertrophic and osteogenic transition.

CONCLUSION

Our study demonstrates a new estrogen-independent role of ERα in mediating chondrocyte phenotype and its response to mechanical loading, and suggests that enhancing ERα level may represent a new method to treat osteoarthritis.

[The predictive value of the CHA2DS2-VASc score for in-hospital outcomes in patients with acute myocardial infarction: China PEACE-retrospective acute myocardial infarction study]

Objectives: This study aimed to evaluate the predictive value of the CHA₂DS₂-VASc score for in-hospital outcomes of patients with acute myocardial infarction (AMI). Methods: Data of 23 728 patients from the China patient-centered Evaluative Assessment of cardiac Events (China PEACE)Retrospective Acute Myocardial Infarction Study were analyzed retrospectively. The patients were categorized into 3 groups according to the CHA₂DS₂-VASc scores: the low score group (score 1-3), the middle score group (score 4-6) and the high score group (score 7-9). The in-hospital outcomes included major adverse cardiovascular events (MACE), death, death or withdrawal from treatment, reinfarction, ischemic stroke,etc. The CHA₂DS₂-VASc score was incorporated into multivariate Cox regression analyses to determine its independent impact on in-hospital outcomes. Receiver operating Characteristic (ROC) curves were constructed, and the area under the curve (AUC) was used to evaluate the predictive value of the CHA₂DS₂-VASc score for in-hospital mortality and death or withdrawal from treatment, respectively. Results: The patients had a median age of 66 (56,75) years, and 30.7% of them were females. Patients with higher CHA₂DS₂-VASc scores had a higher in-hospital mortality and more in-hospital complications (all P<0.001). After adjustment of baseline covariates, the subjects in the high score group were associated with high risks of in-hospital mortality (OR=6.13, 95%CI 4.77-7.87, P<0.001), death or treatment withdrawal (OR=6.43, 95%CI 5.16-8.00, P<0.001) and MACE (OR=4.94, 95%CI 4.06-6.01, P<0.001). The AUCs of the CHA₂DS₂-VASc score were comparable with those of the mini-global registry of acute coronary events(mini-GRACE)score in evaluation of in-hospital mortality (0.699 vs. 0.696, P=0.752) and the death or treatment withdrawal risk (0.708 vs. 0.713, P=0.489). Conclusions: The CHA₂DS₂-VASc score is an independent predictor of in-hospital outcomes for patients with AMI. Its predictive value was comparable with the mini-GRACE score, which could be used as a simple tool for early and rapid outcome evaluation for AMI patients.

[A nomogram for predicting lymph node metastasis in early gastric cancer]

Objective: To explore the independent risk factors of lymph node metastasis (LNM) in early gastric cancer, and to use nomogram to construct a prediction model for above LNM. Methods: A retrospective cohort study was conducted. Inclusion criteria: (1) primary early gastric cancer as stage pT1 confirmed by postoperative pathology; (2) complete clinicopathological data. Exclusion criteria: (1) patients with advanced gastric cancer, stump gastric cancer or history of gastrectomy; (2) early gastric cancer patients confirmed by pathology after neoadjuvant chemotherapy; (3) other types of gastric tumors, such as lymphoma, neuroendocrine tumor, stromal tumor, etc.; (4) primary tumors of other organs with gastric metastasis. According to the above criteria, 1633 patients with early gastric cancer who underwent radical gastrectomy at the Department of General Surgery of the Chinese PLA General Hospital First Medical Center from December 2005 to December 2020 were enrolled as training set, meanwhile 239 patients with early gastric cancer who underwent gastrectomy at the Department of General Surgery of the Chinese PLA General Hospital Fourth Medical Center from December 2015 to December 2020 were enrolled as external validation set. Risk factors of LNM in early gastric cancer were identified by using univariate and multivariate logistic regression analyses. A nomogram prediction model was established with significant factors screened by multivariate analysis. Area under the receiver operating characteristic curve (AUC) was used for assessing the predictive value of the model. Calibration curve was drawn for external validation. Results: Among 1633 patients in training set, the mean number of retrieved lymph nodes was 20 (13-28), and 209 patients (12.8%) had lymph node metastasis. Univariate analysis showed that gender, resection range, tumor location, tumor morphology, lymph node clearance, vascular invasion, lymphatic cancer thrombus, tumor length, tumor differentiation, microscopic presence of signet ring cells and depth of tumor invasion were associated with LNM (all P<0.05). Multivariate analysis revealed that females, tumor morphology as ulcer type, vascular invasion, lymphatic cancer thrombus, tumor length≥3 cm, deeper invasion of mucosa, and poor differentiation were independent risk factors for LNM in early gastric cancers (all P<0.05). Receiver operating characteristic curve indicated that AUC of training set was 0.818 (95%CI: 0.790-0.847) and AUC of external validation set was 0.765 (95%CI: 0.688-0.843). The calibration curve showed that the LNM probability predicted by nomogram was consistent with the actual situation (C-index: 0.818 in training set and 0.765 in external validation set). Conclusions: Females, tumor morphology as ulcer type, vascular invasion, lymphatic cancer thrombus, tumor length≥3 cm, deeper invasion of mucosa and poor differentiation are independent risk factors for LNM of early gastric cancer. The establishment of a nomogram prediction model for LNM in early gastric cancer has great diagnostic value and can provide reference for treatment selection.