Young human plasma-derived extracellular vesicles rescue and reactivate IL-1β and TNF-α treated chondrocytes

Osteoarthritis (OA) is a degenerative disease that affects millions of individuals worldwide. Despite its prevalence, the exact causes and mechanisms behind OA are still not fully understood, resulting in a lack of effective treatments to slow down or halt disease progression. Recent research has discovered that extracellular vesicles (EVs) present in the circulation of young mice have a remarkable ability to activate musculoskeletal stem cells in elderly mice. Conversely, EVs derived from elderly mice do not exhibit the same potential, indicating that EVs obtained from young individuals may hold promise to activate aging cells in degenerative tissue. However, it remains unknown whether EVs derived from young individuals can also address cartilage degeneration caused by aging. In this study, we first evaluated EVs derived from young human plasma (YEVs) and EVs derived from old human plasma (OEVs) in an in vitro experiment using chondrocytes. The results revealed that YEVs effectively stimulated chondrocyte proliferation and migration, while OEVs from old plasma did not exhibit a similar effect. Given that OA represents a more complex inflammatory microenvironment, we further determine whether the benefits of YEVs on chondrocytes can be maintained in this context. Our findings indicate that YEVs have the ability to positively regulate chondrocyte function and protect them against apoptosis induced by IL-1β and TNF-α in an in vitro OA model. Furthermore, we discovered that lyophilized EVs could be stored under mild conditions without any alterations in their physical characteristics. Considering the exceptional therapeutic effects and the wide availability of EVs from young plasma, they hold significant promise as a potential approach to activate chondrocytes and promote cartilage regeneration in early-stage OA.

Mechanical overload-induced release of extracellular mitochondrial particles from tendon cells leads to inflammation in tendinopathy

Tendinopathy is one of the most common musculoskeletal diseases, and mechanical overload is considered its primary cause. However, the underlying mechanism through which mechanical overload induces tendinopathy has not been determined. In this study, we identified for the first time that tendon cells can release extracellular mitochondria (ExtraMito) particles, a subtype of medium extracellular particles (mEPs), into the environment through a process regulated by mechanical loading. RNA sequencing systematically revealed that oxygen-related reactions, extracellular particles, and inflammation were present in diseased human tendons, suggesting that these factors play a role in the pathogenesis of tendinopathy. We simulated the disease condition by imposing a 9% strain overload on three-dimensional mouse tendon constructs in our cyclic uniaxial stretching bioreactor. The three-dimensional mouse tendon constructs under normal loading with 6% strain exhibited an extended mitochondrial network, as observed through live-cell confocal laser scanning microscopy. In contrast, mechanical overload led to a fragmented mitochondrial network. Our microscopic and immunoblot results demonstrated that mechanical loading induced tendon cells to release ExtraMito particles. Furthermore, we showed that mEPs released from tendon cells overloaded with a 9% strain (mEP9%) induced macrophage chemotaxis and increased the production of proinflammatory cytokines, including IL-6, CXCL1, and IL-18, from macrophages compared to mEP0%, mEP3%, and mEP6%. Partial depletion of the ExtraMito particles from mEP9% by magnetic-activated cell sorting significantly reduced macrophage chemotaxis. N-acetyl-L-cysteine treatment preserved the mitochondrial network in overloaded tendon cells, diminishing overload-induced macrophage chemotaxis toward mEP9%. These findings revealed a novel mechanism of tendinopathy; in an overloaded environment, ExtraMito particles convey mechanical response signals from tendon cells to the immune microenvironment, culminating in tendinopathy.

Circulating Metabolites and Dental Traits: A Mendelian Randomization Study

It is of great importance to uncover causal biomarkers to gain insight into the pathogenesis of oral diseases and identify novel treatment targets for prevention and treatment thereof. This study aimed to systematically evaluate the causal effects of hundreds of metabolites on 10 dental traits using a 2-sample Mendelian randomization (MR) approach. Genetic variants from genome-wide association studies of 309 known metabolites were used as instrumental variables. We selected 10 dental traits, including clinical measures of dental diseases, from the Gene-Lifestyle Interactions in Dental Endpoints Consortium and self-reported oral health data from the UK Biobank. The causal relationships between metabolites and dental traits were inferred using the inverse variance-weighted approach and further controlled for horizontal pleiotropy using 5 additional MR methods. After correcting for multiple tests, 5 metabolites were identified as causal biomarkers. Genetically predicted increased levels of mannose were associated with lower risk of bleeding gums (odds ratio [OR] = 0.72; 95% confidence interval [CI], 0.61-0.85; P = 9.9 × 10-5). MR also indicated 4 metabolites on the causal pathway to dentures, with fructose (OR = 0.50; 95% CI, 0.36-0.70; P = 5.2 × 10-5) and 1-palmitoleoyl-glycerophosphocholine (OR = 0.67; 95% CI, 0.56-0.81; P = 4.8 × 10-5) as potential protective factors and glycine (OR = 1.22; 95% CI, 1.11-1.35; P = 5.6×10-5) and 1,5-anhydroglucitol (OR = 1.32; 95% CI, 1.14-1.52; P = 1.5 × 10-4) as risk factors. The causal associations were robust in various sensitivity analyses. We further observed some shared metabolites among different dental traits, implying similar biological mechanisms underlying the pathogenic processes. Finally, the pathway analysis revealed several significant metabolic pathways that may be involved in the development of dental disorders. Our study provides novel insights into the combination of metabolomics and genomics to reveal the pathogenesis of and therapeutic strategies for dental disorders. It highlighted 5 metabolites and several pathways as causal candidates, warranting further investigation.

Psychological effects of COVID-19 outbreak on mental health in parents of children with hematopathy

OBJECTIVE

We explored whether parents of children with hematopathy had more psychosocial problems than parents of healthy children during the COVID-19 outbreak.

SUBJECTS AND METHODS

An online survey was performed, and a total of 1,116 parents participated. The mental health variables were assessed via the Simplified Coping Style Questionnaire (SCSQ) and the Symptom Checklist-Revised (SCL-90-R).

RESULTS

Compared with parents of healthy children, parents of children with hematopathy have a higher possibility of negative coping style (70.9% vs. 33.2%, p=0.01) and are more concerned with media reports related to the pandemic (37.8% vs. 17.6%, p=0.02). In SCL-90-R somatization, obsessive-compulsive, and anxiety scale, the parents of children with hematopathy have higher scores than parents of healthy children (12.50±1.69 vs. 12.23±1.37, p<0.01; 13.42±6.69 vs. 10.47±2.25, p<0.01; 15.21±5.53 vs. 10.52±2.34, p<0.01, respectively). History of visiting Wuhan, and history of epidemics occurring in the community are independent risk factors of parental obsessive-compulsive and anxiety symptoms (p<0.01).

CONCLUSIONS

Parents of children with hematopathy had evident severe symptoms of obsessive-compulsive and anxiety during the outbreak of COVID-19. Providing psychological interventions and beneficial approaches to parents of children with hematopathy urgently needs to be realized.

Bone turnover biomarkers predict one-year all-cause mortality and walking ability in geriatric hip fracture patients

PURPOSE

To investigate the utility of serum C-terminal cross-linking telopeptides (β-CTX) and procollagen type I N propeptide (PINP) for predicting one-year mortality and walking ability in Chinese geriatric hip fracture patients who underwent surgical interventions.

METHOD

Elderly patients (≥ 60 years) who underwent surgical interventions for unilateral low-energy hip fracture from 2015 to 2020 in our center were included. Demographic data was retrospectively retrieved from the electronic medical database. The PINP and β-CTX concentrations were measured before the surgery. The patients were divided into two groups according to the outcome of mortality and walking ability after hip surgery, respectively. β-CTX and PINP were divided into four grades based on quartiles [Quartile(Q)1-4] for further analysis. All the variables with p < 0.1 in univariable analysis were included in a multivariable model.

RESULTS

In univariable analysis, the levels of serum β-CTX (p = 0.007) and PINP (p = 0.025) was associated with one-year mortality, while the association between levels of serum β-CTX (p = 0.072) or PINP (p = 0.055) with one-year disability was marginally significant. After adjustment for confounders, the relative risk [OR (95 % CI), Q4 v sQ1, p-value] of one-year mortality and one-year disability were 7.28 (2.08-29.78, p = 0.003) and 3.97 (1.44-11.69, p = 0.009) for β-CTX and 5.87 (1.70-23.80, p = 0.008) and 3.48 (1.30-9.93, p = 0.016) for PINP, respectively. The coefficient of determination, AUC and bias-corrected C-index of predictive models based on previously reported predictors were significantly improved after integrating β-CTX or PINP.

CONCLUSION

Higher serum β-CTX and PINP are independently associated with an increased risk of one-year mortality and disability in patients with hip fractures. The application of BTMs improves the performance of currently available predictive models.

In situ fabrication of an anisotropic double-layer hydrogel as a bio-scaffold for repairing articular cartilage and subchondral bone injuries

Articular cartilage is a smooth and elastic connective tissue playing load-bearing and lubricating roles in the human body. Normal articular cartilage comprises no blood vessels, lymphatic vessels, nerves, or undifferentiated cells, so damage self-repair is very unlikely. The injuries of articular cartilage are often accompanied by damage to the subchondral bone. The subchondral bone mainly provides mechanical support for the joint, and the successful repair of articular cartilage depends on the ability of the subchondral bone to provide a suitable environment. Currently, conventional repair treatments for articular cartilage and subchondral bone defects can hardly achieve good results due to the poor self-repairing ability of the cartilage Here, we propose a bioactive injectable double-layer hydrogel to repair articular cartilage and subchondral bone. The hydrogel scaffold mimics the multilayer structure of articular cartilage and subchondral bone. Agarose was used as a common base material for the double-layer hydrogel scaffold, in which a sodium alginate (SA)/agarose layer was used for the repair of artificially produced subchondral bone defects, while a decellularized extracellular matrix (dECM)/agarose layer was used for the repair of articular cartilage defects. The double-layer hydrogel scaffold is injectable, easy to use, and can fill in the damaged area. The hydrogel scaffold is also anisotropic both chemically and structurally. Animal experiments showed that the surface of the new cartilage tissue in the double-layer hydrogel scaffold group was closest to normal articular cartilage, with a structure similar to that of hyaline cartilage and a preliminary calcified layer. Moreover, the new subchondral bone in this group exhibited many regular bone trabeculae, and the new cartilage and subchondral bone were mechanically bound without mutual intrusion and tightly integrated with the surrounding tissue. The continuous double-layer hydrogel scaffold prepared in this study mimics the multilayer structure of articular cartilage and subchondral bone and promotes the functional repair of articular cartilage and subchondral bone, favoring close integration between the newborn tissue and the original tissue.

[Clinical observation on the efficacy and safety of dupilumab in the treatment of moderate to severe atopic dermatitis]

To investigate the clinical efficacy and safety of dupilumab in the treatment of moderate to severe atopic dermatitis (AD) in China. A small sample self-controlled study before and after treatment was conducted to retrospective analysis patients with moderate to severe AD treated with dupilumab in the department of dermatology of the First Affiliated Hospital of Chongqing Medical University from July 2020 to March 2022. Dupilumab 600 mg was injected subcutaneously at week 0, and then 300 mg was injected subcutaneously every 2 weeks. The condition was evaluated by SCORAD(severity scoring of atopic dermatitis), NRS(numerical rating scale), DLQI(dermatology life quality index) and POEM(patient-oriented eczema measure). The improvement of SCORAD, NRS, DLQI and POEM was analyzed by paired t test and non-parametric paired Wilcoxon. The results showed that a total of 67 patients with moderate to severe AD received dupilumab treatment, of which 41 patients (the course of treatment was more than 6 weeks) had reduced the severity of skin lesions, improved quality of life and reduced pruritus. A total of 23 patients completed 16 weeks of treatment. At 4, 8, 12 and 16 weeks, SCORAD, NRS, DLQI and POEM decreased compared with the baseline, and the differences were statistically significant. SCORAD (50.13±15.19) at baseline, SCORAD (36.08±11.96)(t=6.049,P<0.001) at week 4,SCORAD (28.04±11.10)(t=10.471,P<0.001) at week 8, SCORAD (22.93±9.72)(t=12.428,P<0.001) at week 12, SCORAD (16.84±7.82)(t=14.609,P<0.001) at week 16, NRS 7(6,8) at baseline, NRS 4(3,5)(Z=-3.861,P<0.001) at week 4, NRS 2(1,4)(Z=-4.088,P<0.001) at week 8, NRS 1(0,2)(Z=-4.206,P<0.001) at week 12, NRS 2(0,2)(Z=-4.222,P<0.001) at week 16, DLQI (13.83±5.71) at baseline, DLQI (8.00±4.02)(t=6.325,P<0.001) at week 4, DLQI (5.61±3.50)(t=8.060,P<0.001) at week 8, DLQI (3.96±1.99)(t=8.717,P<0.001) at week 12, DLQI (2.70±1.89)(t=10.355,P<0.001) at week 16, POEM (18.04±6.41) at baseline, POEM (9.70±4.70)(t=7.031,P<0.001) at week 4, POEM (7.74±3.48)(t=8.806,P<0.001) at week 8, POEM (6.35±3.33)(t=10.474,P<0.001) at week 12, POEM (4.26±2.51)(t=11.996,P<0.001) at week 16. In the 16th week, 100%(23 patients), 91.3%(21 patients), 34.8%(8 patients) and 8.7%(2 patients) of 23 patients reached SCORAD30, SCORAD50, SCORAD70, and SCORAD90 statuses, respectively. There were 82.6%(19 patients), 95.7%(22 patients) and 95.7%(22 patients) of 23 patients with NRS, DLQI and POEM improved by≥4 points compared with baseline. Twelve patients with AD who continued to receive dupilumab after 16 weeks showed further improvement in skin lesions. The adverse events were conjunctivitis and injection site reaction. In conclusion, dupilumab is an effective and safe treatment for moderate and severe AD. However, the longer-term efficacy and safety require further studies involving larger sample sizes and a longer follow-up time.

Nano wear particles and the periprosthetic microenvironment in aseptic loosening induced osteolysis following joint arthroplasty

Joint arthroplasty is an option for end-stage septic arthritis due to joint infection after effective control of infection. However, complications such as osteolysis and aseptic loosening can arise afterwards due to wear and tear caused by high joint activity after surgery, necessitating joint revision. Some studies on tissue pathology after prosthesis implantation have identified various cell populations involved in the process. However, these studies have often overlooked the complexity of the altered periprosthetic microenvironment, especially the role of nano wear particles in the etiology of osteolysis and aseptic loosening. To address this gap, we propose the concept of the "prosthetic microenvironment". In this perspective, we first summarize the histological changes in the periprosthetic tissue from prosthetic implantation to aseptic loosening, then analyze the cellular components in the periprosthetic microenvironment post prosthetic implantation. We further elucidate the interactions among cells within periprosthetic tissues, and display the impact of wear particles on the disturbed periprosthetic microenvironments. Moreover, we explore the origins of disease states arising from imbalances in the homeostasis of the periprosthetic microenvironment. The aim of this review is to summarize the role of relevant factors in the microenvironment of the periprosthetic tissues, in an attempt to contribute to the development of innovative treatments to manage this common complication of joint replacement surgery.

Chemoradiotherapy Combined with Nab-Paclitaxel plus Cisplatin in Patients with Locally Advanced Borderline Resectable or Unresectable Esophageal Squamous Cell Carcinoma: A Phase I/II Study

PURPOSE/OBJECTIVE(S)

To evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus cisplatin as the regimen of conversional chemoradiotherapy (cCRT) in locally advanced borderline resectable or unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Patients with locally advanced ESCC (cT3-4, Nany, M0-1, M1 was limited to lymph node metastasis in the supraclavicular area) were enrolled. All the patients received the cCRT of nab-PTX plus cisplatin. After the cCRT, those resectable patients received esophagectomy; those unresectable patients continued to receive the definitive chemoradiotherapy (dCRT). The locoregional control (LRC), overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), pathological complete response (pCR), R0 resection rate and adverse events (AEs) were calculated.

RESULTS

A total of 45 patients with ESCC treated from October 2019 to May 2021 were finally included. The median follow-up time was 30.3 months. The LRC, OS, EFS, DMFS at 1and 2 years were 81.5%, 86.6%, 64.3%, 73.2% and 72.4%, 68.8%, 44.8%, 52.7% respectively. 21 patients (46.7%) received conversional chemoradiotherapy plus surgery (cCRT+S). The pCR rate and R0 resection rate were 47.6% and 84.0%. The LRC rate at 1 and 2 years were 95.0%, 87.1% in cCRT+S patients and 69.3%, 58.7% in dCRT patients respectively (HR, 5.14; 95% CI, 1.10-23.94; P = 0.021). The OS rate at 1 and 2 years were 95.2% and 84.2% in resectable patients compared to 78.8% and 54.4% in unresectable patients (HR, 3.41; 95% CI, 1.10-10.61; P = 0.024). The toxicities during chemoradiotherapy were tolerated, the most common grade 3-4 toxicities were radiation esophagitis (15.6%).

CONCLUSION

Nab-PTX plus cisplatin were effective and safe as the regimen of conversional chemoradiotherapy of ESCC. The patients receiving conversional chemoradiotherapy plus surgery (cCRT+S) were prone to have a better survival.

[Untargeted metabolomics study of dexamethasone-induced congenital cleft palate in New Zealand rabbits]

Objective: To investigate the metabolic disorders in placental tissues of dexamethasone induced cleft palate mode. Methods: Twelve pregnant rabbits were randomly divided into dexamethasone group (experimental group, 8) and saline control group (4), and a certain amount of dexamethasone and saline were administered intramuscularly to the experimental and control groups respectively from embryonic days (ED) 13 to 16, and placental tissue samples were collected on day 21 of gestation. The corresponding profiles of the embryonic placental tissue samples were obtained by liquid chromatography-triple tandem quadrupole(LC-MS), and the metabolites of the embryonic placental tissues were characterized by principal component analysis among the dexamethasone-treated group with cleft palate (D-CP group), the dexamethasone-treated group without cleft palate (D-NCP group) and the control group. Results: There were significant metabolic differences among the D-CP group, D-NCP group and control group, with a total of 133 differential metabolites (VIP>1, P<0.05) involving in important metabolic pathways including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism, and galactose metabolism. The four metabolites, vitamin B6, galactose, lysine and urea, differed among the three groups (P<0.05). There were significant differences in vitamin B6 (0.960±0.249, 0.856±0.368, 1.319±0.322), galactose (0.888±0.171, 1.033±0.182, 1.127±0.127), lysine (1.551±0.924, 1.789±1.435, 0.541±0.424) and urea (0.743±0.142, 1.137±0.301, 1.171±0.457, respectively) levels among control group, D-NCP group and D-CP group (F=5.90, P=0.008; F=5.59, P=0.009; F=4.26, P=0.025; F=5.29, P=0.012). Conclusions: The results indicated that dexamethasone induced cleft palate may be highly correlated with metabolic disorders including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism and galactose metabolism.

Stem cell therapy combined with core decompression versus core decompression alone in the treatment of avascular necrosis of the femoral head: a systematic review and meta-analysis

INTRODUCTION

Accumulated clinical trials had been focused on stem cell therapy in combination of core decompression (CD) in the treatment of avascular necrosis of the femoral head (ANFH). Nonetheless, the results were inconclusive. Here, we performed a systematic review and meta-analysis of previous randomized controlled trials (RCTs) and retrospective studies to assess whether combined stem cell augmentation with CD improved the outcomes of ANFH compared with CD alone.

METHODS

The current study included 11 RCTs and 7 retrospective studies reporting the clinical outcomes of a total of 916 patients and 1257 hips. 557 and 700 hips received CD and CD plus stem cell therapy, respectively. To compare CD with CD plus stem cell therapy, we examined the clinical evaluating scores, the occurrence of the femoral head, radiologic progression and conversion to total hip arthroplasty (THA).

RESULTS

Only 10 studies reported significantly greater improvement in hip functions while combining stem cell procedure with CD. The pooled results in subgroup analysis indicated that stem cell group had a lower collapse rate on a mid-term basis (P = 0.001), when combined with mechanical support (P < 0.00001), and with extracted stem cells (P = 0.0002). Likewise, stem cell group had a lower radiographic progression rate at 2- to 5-year follow-up [P = 0.003], when combined with structural grafting (P < 0.00001), and with extracted stem cells (P = 0.004). Stem cell therapy resulted in an overall lower THA conversion rate (P < 0.0001) except that at a follow-up longer than 5 years.

CONCLUSION

Stem cell therapy combined with core decompression was more effective in preventing collapse, radiographic progression and conversion to THA. Trial Registration The current protocol has been registered in PROSPERO with the registration number: CRD42023417248.

Baseline Knee Pain Predicts Long-Term Response of Intra-Articular Steroid Injection in Symptomatic Knee Osteoarthritis: Data from OAI

OBJECTIVE

The current study aims to investigate the factors that could predict response to intra-articular corticosteroid injection (IACI) in patients with knee osteoarthritis (KOA).

METHODS

Data of participants were retrieved from the Osteoarthritis Initiative database. Participants with at least one IACI treatment on single or bilateral knees within the first 5 years of follow-up were retrospectively included. Demographic data, clinical and radiographic variables were collected at both baseline and the first follow-up after IACI treatment. Positive response to IACI treatment was defined as >20% reduction of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score from V0 to V1. All the variables with P < 0.2 after the comparison between the response and non-response groups were included in a multivariable logistic regression model to identify independent response predictive patient-specific valuables. Receiver operating characteristic curves were performed to establish the cutoff values of independent predictors.

RESULTS

The current study included a total of 385 participants (473 knees), with 155 and 318 knees classified into the response group and non-response group, respectively. Those with satisfied responses to IACI treatment had significantly higher WOMAC pain score (P < 0.001), disability score (P = 0.002), and stiffness score (P = 0.015) at the baseline. Baseline WOMAC pain score showed significant association with positive response to IACI treatment in multivariate logistic analysis and the best cutoff value was 5 points. The rate of analgesics utilization was lower (P = 0.014) in the response group than the non-response group after the IACI treatment.

CONCLUSION

KOA patients with a baseline WOMAC pain score ≥5 are more likely to benefit from IACI treatment.

Deep-learning measurement of intracerebral haemorrhage with mixed precision training: a coarse-to-fine study

AIM

To develop a unified deep-learning-based method for automated intracerebral haemorrhage (ICH) segmentation on computed tomography (CT) images with different layer thickness parameters.

MATERIALS AND METHODS

A total of 134 patients from an internal database (67 patients) and an external database (called CQ500, 67 patients) were employed. The CT examinations included multiple layer thicknesses such as 0.625, 1.25 and 5 mm. ICH segmentation was performed by a coarse-to-fine strategy, including three stages of three-dimensional (3D) skull-stripping segmentation, 3D ICH localisation segmentation, and two-dimensional (2D) ICH fine segmentation. The three stages shared the same sICHNet for segmentation and employed mixed precision training to speed up the training process. In addition, the 3D contextual information from CT was maintained by formatting the consecutive slices into a three-channel image in the 2D ICH fine segmentation.

RESULTS

Experimental results demonstrated that the coarse-to-fine segmentation strategy achieved the best performance with a mean Dice coefficient of 0.887. ICH volume consistency was observed (p<0.05) between manual and automatic segmentations, and between segmentations of same individual but with different layer thicknesses in internal dataset and external database. Automated segmentation achieved a relatively consistent segmentation time of 20.01 ± 2.03 seconds no matter the layer thickness of the CT images and the extent of ICH. Longitudinal studies with conservative management and surgical treatment were also visualised.

CONCLUSIONS

The coarse-to-fine deep learning strategy achieved the best ICH segmentation performance on CT images. The automated segmentation was 5-42 times faster than manual segmentation given ICH of different extents and using different layer thickness parameters.

Activating Endogenous Neurogenesis for Spinal Cord Injury Repair: Recent Advances and Future Prospects

After spinal cord injury (SCI), endogenous neural stem cells are activated and migrate to the injury site where they differentiate into astrocytes, but they rarely differentiate into neurons. It is difficult for brain-derived information to be transmitted through the injury site after SCI because of the lack of neurons that can relay neural information through the injury site, and the functional recovery of adult mammals is difficult to achieve. The development of bioactive materials, tissue engineering, stem cell therapy, and physiotherapy has provided new strategies for the treatment of SCI and shown broad application prospects, such as promoting endogenous neurogenesis after SCI. In this review, we focus on novel approaches including tissue engineering, stem cell technology, and physiotherapy to promote endogenous neurogenesis and their therapeutic effects on SCI. Moreover, we explore the mechanisms and challenges of endogenous neurogenesis for the repair of SCI.

Distribution of bone voids in the thoracolumbar spine in Chinese adults with and without osteoporosis: A cross-sectional multi-center study based on 464 vertebrae

Bone void is a novel intuitive morphological indicator to assess bone quality but its use in vertebrae has not been described. This cross-sectional and multi-center study aimed to investigate the distribution of bone voids in the thoracolumbar spine in Chinese adults based on quantitative computed tomography (QCT). A bone void was defined as a trabecular net region with extremely low bone mineral density (BMD) (<40 mg/cm³), detected by an algorithm based on phantom-less technology. A total of 464 vertebrae from 152 patients (51.8 ± 13.4 years old) were included. The vertebral trabecular bone was divided into eight sections based on the middle sagittal, coronal, and horizontal planes. Bone void of the whole vertebra and each section were compared between healthy, osteopenia, and osteoporosis groups and between spine levels. Receiver operator characteristic (ROC) curves were plotted and optimum cutoff points of void volume between the groups were obtained. The total void volumes of the whole vertebra were 124.3 ± 221.5 mm³, 1256.7 ± 928.7 mm^3, and 5624.6 ± 3217.7 mm³ in healthy, osteopenia, and osteoporosis groups, respectively. The detection rate of vertebrae with bone voids was higher and the normalized void volume was larger in the lumbar than in thoracic vertebrae. L3 presented the largest void (2165.0 ± 3396.0 mm³), while T12 had the smallest void (448.9 ± 699.4 mm³). The bone void was mainly located in the superior-posterior-right section (40.8 %). Additionally, bone void correlated positively with age and increased rapidly after 55 years. The most significant void volume increase was found in the inferior-anterior-right section whereas the least increase was found in the inferior-posterior-left section with aging. The cutoff points were 345.1 mm³ between healthy and osteopenia groups (sensitivity = 0.923, specificity = 0.932) and 1693.4 mm³ between osteopenia and osteoporosis groups (sensitivity = 1.000, specificity = 0.897). In conclusion, this study demonstrated the bone void distribution in vertebrae using clinical QCT data. The findings provide a new perspective for the description of bone quality and showed that bone void could guide clinical practice such as osteoporosis screening.

[Changes of intestinal wall barrier function and its correlation with susceptibility to infection in patients with cirrhotic portal hypertension]

Objective: To investigate the changes of intestinal wall barrier function and its correlation with infection occurrence in patients with cirrhotic portal hypertension. Methods: 263 patients with cirrhotic portal hypertension were split into: the clinically evident portal hypertension (CEPH) combined with infection group (n = 74); CEPH group (n = 104); and Non-CEPH group (n = 85). Among them, 20 CEPH patients and 12 non-CEPH patients in non-infection status were subjected to sigmoidoscopy. Immunohistochemical staining was used to detect the expression of trigger receptor-1 (TREM-1), CD68, CD14, the inducible nitric oxide synthase molecule, and Escherichia coli (E.coli) in the medullary cells of the colon mucosa. An enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of soluble myeloid cell trigger receptor-1 (sTREM-1), soluble leukocyte differentiation antigen-14 subtype (sCD14-ST) and intestinal wall permeability index enteric fatty acid binding protein (I-FABP). Fisher's exact probability method, one-way ANOVA, Kruskal-Wallis-H test, Bonferroni method, and Spearman correlation analysis were used for statistical analysis. Results: The serum sTREM-1 and I-FABP levels were higher in CEPH patients than those of non-CEPH patients in the non-infectious state (P < 0.05), but the difference in blood sCD14-ST levels was not statistically significant (P > 0.05). Serum levels of sTREM-1, sCD14-ST, and I-FABP in infected patients were higher than those in patients without a concurrent infection (P < 0.05). Serum sCD14-ST levels were positively correlated with serum sTREM-1, C-reactive protein (CRP), and procalcitonin (PCT), and sTREM-1 levels were also positively correlated with CRP and PCT (r > 0.5, P < 0.001). The rates of CD68, inducible nitric oxide synthase, CD14-positive cells, and E.coli-positive glands were higher in the intestinal mucosa of the CEPH group than those of the control group (P < 0.05). Spearman's correlation analysis showed that the rate of E.coli-positive glands in CEPH patients was positively correlated with the expression of molecular markers CD68 and CD14 in the lamina propria macrophages. Conclusion: Patients with cirrhotic portal hypertension have increased intestinal permeability and inflammatory cells, accompanied by bacterial translocation. Serum sCD14-ST and sTREM-1 can be used as indicators to predict and evaluate the occurrence of infection in patients with cirrhotic portal hypertension.

Preoperative Vitamin D Deficiency is Associated with Increased One-Year Mortality in Chinese Geriatric Hip Fracture Patients - A Propensity Score Matching Study

BACKGROUND

Vitamin D deficiency is a common comorbidity in geriatric hip fracture patients. However, there is still an ongoing debate regarding the influence of preoperative Vitamin D status on postoperative mortality in hip fracture patients.

METHODS

Elderly patients (≥60 years) who underwent surgical interventions for unilateral hip fracture from 2015 to 2020 in our center were included. We retrospectively retrieved the demographic data from the electronic medical database. Preoperative serum total 25-hydroxy-Vitamin D was set as the independent variable and patients were classified as the Vitamin D deficiency (<20ng/mL) and the control groups consequently. Clinical outcomes include all-cause mortality, walking ability, and major postoperative complications in the first postoperative year. Propensity score matching (PSM) was performed in a ratio of 1:1 in the two groups for further comparison.

RESULTS

A total of 210 patients were included and 121 patients (57.6%) were diagnosed with Vitamin D deficiency. Patients in the Vitamin D deficiency group were much older and therefore preferred peripheral nerve block, and had significantly higher proportions of females, preoperative dementia, higher ASA grade, and lower baseline serum albumin level. Overall, 79 patients were identified in the Vitamin D deficiency and control groups after PSM, respectively. Patients diagnosed with Vitamin D deficiency showed a significantly higher one-year mortality (21.5% vs 6.3%, P=0.011) and a much lower one-year independent walking rate (67.1% vs.84.8%, P=0.016) after the matching. Regarding the dataset before PSM and after PSM, the AUC for serum Vitamin D for predicting one-year mortality was 0.656 (P=0.006) and 0.695 (P=0.002), respectively.

CONCLUSION

Our retrospective PSM-design study provides new evidence that Vitamin D deficiency was associated with a significantly higher mortality and poor walking ability in the first year after surgical intervention based on southern Chinese populations.

Contralateral advanced radiographic knee osteoarthritis predicts radiographic progression and future arthroplasty in ipsilateral knee with early-stage osteoarthritis

PURPOSE

To explore whether the severity of contralateral knee osteoarthritis (OA) is associated with OA progression in ipsilateral knee with early OA.

METHODS

Knees in early OA (Kellgren-Lawrence grade (KLG):1-2) with intact baseline demographic and clinical data were retrieved from OAI database and defined as target knees. The target knees were divided into the exposure group (contralateral knees KLG 3 to 4) and the control group (contralateral knees KLG 0 to 2). Both groups underwent propensity score matching (PSM) concerning demographic data, as well as radiographic and clinical outcomes at the baseline. The primary outcome was the upgrade of KLG in the target knee in the first 12 and 24 months. The secondary outcome was the incidence of knee arthroplasty in ipsilateral knee during the first 108 months.

RESULTS

One thousand seven hundred fifty-two knees were included, with 449 in the exposure cohort and 1276 in the control cohort. Four hundred thirty-four knees in each group were matched after PSM. Target knees in the exposure cohort showed a significantly higher rate of radiographic progression in the first 12 months (12.9% vs. 5.1%, P < 0.001) and 24 months (19.6% vs. 8.1%, P < 0.001). As for the risk of future arthroplasty, a significant difference was also found between the two groups (7.8% vs. 4.0%, P = 0.02). Kaplan-Meier analysis showed that the 108-month accumulated knee survival rate was significantly lower in the exposure group (P = 0.01).

CONCLUSION

The ipsilateral knee with early-stage OA is prone to have worse early to mid-, and long-term prognosis in the circumstance of contralateral radiographic advanced knee OA. Key Points •Identifying early knee osteoarthritis (OA) with a high risk of radiographic progression and future arthroplasty enables early personalized intervention. •This is a novel study to investigate the relationship between the risk of future arthroplasty and contralateral knee status. •Propensity score matching holds promise to minimize selection bias in observational studies. •Knees with early OA are prone to have a high risk of radiographic progression and future arthroplasty in the circumstance of contralateral advanced knee OA.

Anisotropic hydrogel fabricated by controlled diffusion as a bio-scaffold for the regeneration of cartilage injury

Controlled fabrication of anisotropic materials has become a hotspot in materials science, particularly biomaterials, since the next generation of tissue engineering is based on the application of heterogeneous structures that can simulate the original biological complexity of the body. The current fabrication method of producing anisotropic materials involves expensive and highly specialized equipment, and not every conventional method can be applied to preparing anisotropic materials for corresponding tissue engineering. Anisotropic materials can be easily applied to a problem in tissue engineering: cartilage injury repairing. The articular cartilage consists of four spatially distinct regions: superficial, transitional, deep, and calcified. Each region has a specific extracellular matrix composition, mechanical properties, and cellular organization; this calls for the application of an anisotropic hydrogel. Controlled diffusion, under the assistance of buoyancy, has been considered a generalized method to prepare materials using a gradient. The diffusion of two solutions can be controlled through the difference in their densities. In addition to providing anisotropy, this method realizes the in situ formation of an anisotropic hydrogel, and simplifies the preparation process, freeing it from the need for expensive equipment such as 3D printing and microfluidics. Herein, an anisotropic hydrogel based on a decellularized extracellular matrix is fabricated and characterized. The as-prepared scaffold possessed specific chemical composition, physical properties, and physiological factor gradient. In vitro experiments ensured its biocompatibility and biological effectiveness; further in vivo experiments confirmed its application in the effective regeneration of cartilage injury.

Transcription and proteome changes involved in re-innervation muscle following nerve crush in rats

Severe peripheral nerve injury leads to the irreparable disruption of nerve fibers. This leads to disruption of synapses with the designated muscle, which consequently go through progressive atrophy and damage of muscle function. The molecular mechanism that underlies the re-innervation process has yet to be evaluated using proteomics or transcriptomics. In the present study, multi-dimensional data were therefore integrated with transcriptome and proteome profiles in order to investigate the mechanism of re-innervation in muscles. Two simulated nerve injury muscle models in the rat tibial nerve were compared: the nerve was either cut (denervated, DN group) or crushed but with the nerve sheath intact (re-innervated, RN group). The control group had a preserved and intact tibial nerve. At 4 weeks, the RN group showed better tibial nerve function and recovery of muscle atrophy compared to the DN group. As the high expression of Myh3, Postn, Col6a1 and Cfi, the RN group demonstrated superior re-innervation as well. Both differentially expressed genes (DEGs) and proteins (DEPs) were enriched in the peroxisome proliferator-activated receptors (PPARs) signaling pathway, as well as the energy metabolism. This study provides basic information regarding DEGs and DEPs during re-innervation-induced muscle atrophy. Furthermore, the crucial genes and proteins can be detected as possible treatment targets in the future.

[Analysis of FBN1 genemutations in a pedigree with Marfan syndrome]

Mutations in fibrillin-1 (FBN1) were detected in an autosomal dominant Marfan syndrome (MFS) pedigree. The related phenotypes and the significance of mutation screening were discussed. Complete medical and cardiovascular examinations for all pedigree members were performed. Whole exons sequencing (WES) was used to sequence the DNA of the patients and their relatives. The potential pathogenic mutation sites were screened by bioinformatics method. Sanger sequencing was used to verify the mutation sites in the pedigree. The results showed that FBN1 missense mutation was c.6806 T>C in exon 56, resulting in isoleucine being replaced by threonine (p. Ile2269Thr). This mutation has not been reported in Chinese Han population. The occurrence of the mutations strongly correlated with the phenotypes of the patients. The results expand the mutation spectrum of FBN1, and it is helpful to further explore the molecular pathogenesis of MFS and MFS related diseases.

[Clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma of the breast]

Objective: To investigate the clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma (MSCC) of the breast. Methods: A total of 47 MSCC cases diagnosed in the Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from January 2010 to December 2021 were reviewed. The clinical information (including the follow-up data of HER2 positive patients) and pathological features were collected and analyzed. Results: All of the patients were female. Among the 47 cases, 25 were pure squamous cell carcinoma (PSCC) and 22 were mixed metaplastic carcinoma with squamous cell component (MMSC). The median age of the patients was 54 years (range, 29-84 years). The maximum diameter of the mass ranged from 0.8 to 10.0 cm, with a mean value of 3.3 cm, 85.7% (24/28) of the cases were smaller than 5 cm, and only 4 cases were larger than or equal to 5 cm. 89.5% of the MMSC presented with a solid mass. Cystic changes were more commonly found in the PSCC group (50%, P<0.05) than the MMSC group. 36.7% (11/30) of the patients had lymph node metastasis at the time of diagnosis. The squamous cell carcinoma component in all cases showed diffuse or patchy expression of p63, p40 and CK5/6. 55.3% (26/47) of the cases showed triple-negative phenotype. Among the 7 HER2-positive patients, 6 were MMSC group, which had a significantly higher rate of HER2-positivity than that in the PSCC group (1 case). In 1 MMSC case, immunohistochemistry showed HER2 2+in the invasive ductal carcinoma component and HER2 negativity (0) in the squamous cell carcinoma component, but HER2 FISH was negative in invasive ductal carcinoma and positive in squamous cell carcinoma component. Six HER2-positive MSCC patients received anti-HER2-targeted therapy, including two patients who received neoadjuvant chemotherapy combined with anti-HER2-targeted therapy before surgery. One patient achieved pathological complete remission, while the other achieved partial remission (the residual tumors were squamous cell carcinoma components). After 9-26 months of follow-up, four patients had no disease progression, two patients developed pulmonary metastases, and one patient showed local recurrence. Conclusions: MSCC is a group of heterogeneous diseases. PSCC and MMSC may be two different entities. Most of the MSCC are triple-negative and HER2 positivity is more commonly seen in MMSC with invasive ductal carcinoma component. Some HER2-positive MSCC patients can achieve complete remission or long-term progression-free survival after receiving anti-HER2 targeted therapy, but the squamous cell carcinoma component may be less sensitive to targeted therapy than the invasive ductal carcinoma component.

Challenges and perspectives of tendon-derived cell therapy for tendinopathy: from bench to bedside

Tendon is composed of dense fibrous connective tissues, connecting muscle at the myotendinous junction (MTJ) to bone at the enthesis and allowing mechanical force to transmit from muscle to bone. Tendon diseases occur at different zones of the tendon, including enthesis, MTJ and midsubstance of the tendon, due to a variety of environmental and genetic factors which consequently result in different frequencies and recovery rates. Self-healing properties of tendons are limited, and cell therapeutic approaches in which injured tendon tissues are renewed by cell replenishment are highly sought after. Homologous use of individual’s tendon-derived cells, predominantly differentiated tenocytes and tendon-derived stem cells, is emerging as a treatment for tendinopathy through achieving minimal cell manipulation for clinical use. This is the first review summarizing the progress of tendon-derived cell therapy in clinical use and its challenges due to the structural complexity of tendons, heterogeneous composition of extracellular cell matrix and cells and unsuitable cell sources. Further to that, novel future perspectives to improve therapeutic effect in tendon-derived cell therapy based on current basic knowledge are discussed.

Brain morphology changes after spinal cord injury: A voxel-based meta-analysis

Objectives

Spinal cord injury (SCI) remodels the brain structure and alters brain function. To identify specific changes in brain gray matter volume (GMV) and white matter volume (WMV) following SCI, we conducted a voxel-based meta-analysis of whole-brain voxel-based morphometry (VBM) studies.

Methods

We performed a comprehensive literature search on VBM studies that compared SCI patients and healthy controls in PubMed, Web of Science and the China National Knowledge Infrastructure from 1980 to April 2022. Then, we conducted a voxel-based meta-analysis using seed-based d mapping with permutation of subject images (SDM-PSI). Meta-regression analysis was performed to identify the effects of clinical characteristics.

Results

Our study collected 20 studies with 22 GMV datasets and 15 WMV datasets, including 410 patients and 406 healthy controls. Compared with healthy controls, SCI patients showed significant GMV loss in the left insula and bilateral thalamus and significant WMV loss in the bilateral corticospinal tract (CST). Additionally, a higher motor score and pinprick score were positively related to greater GMV in the right postcentral gyrus, whereas a positive relationship was observed between the light touch score and the bilateral postcentral gyrus.

Conclusion

Atrophy in the thalamus and bilateral CST suggest that SCI may trigger neurodegeneration changes in the sensory and motor pathways. Furthermore, atrophy of the left insula may indicate depression and neuropathic pain in SCI patients. These indicators of structural abnormalities could serve as neuroimaging biomarkers for evaluating the prognosis and treatment effect, as well as for monitoring disease progression. The application of neuroimaging biomarkers in the brain for SCI may also lead to personalized treatment strategies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021279716, identifier: CRD42021279716.

Exosome-based strategy for degenerative disease in orthopedics: Recent progress and perspectives

BACKGROUND

Degenerative diseases in orthopaedics have become a significant global public health issue with the aging of the population worldwide. The traditional medical interventions, including physical therapy, pharmacological therapy and even surgery, hardly work to modify degenerative progression. Stem cell-based therapy is widely accepted to treat degenerative orthopaedic disease effectively but possesses several limitations, such as the need for strict monitoring of production and storage and the potential risks of tumorigenicity and immune rejection in clinical translation. Furthermore, the ethical issues surrounding the acquisition of embryonic stem cells are also broadly concerned. Exosome-based therapy has rapidly grown in popularity in recent years and is regarded as an ideal alternative to stem cell-based therapy, offering a promise to achieve 'cell-free' tissue regeneration.

METHODS

Traditionally, the native exosomes extracted from stem cells are directly injected into the injured site to promote tissue regeneration. Recently, several modified exosome-based strategies were developed to overcome the limitations of native exosomes, which include mainly exogenous molecule loading and exosome delivery through scaffolds. In this paper, a systematic review of the exosome-based strategy for degenerative disease in orthopaedics is presented.

RESULTS

Treatment strategies based on the native exosomes are effective but with several disadvantages such as rapid diffusion and insufficient and fluctuating functional contents. The modified exosome-based strategies can better match the requirements of the regeneration in some complex healing processes.

CONCLUSION

Exosome-based strategies hold promise to manage degenerative disease in orthopaedics prior to patients reaching the advanced stage of disease in the future. The timely summary and highlights offered herein could provide a research perspective to promote the development of exosome-based therapy, facilitating the clinical translation of exosomes in orthopaedics.

TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Exosome-based therapy is superior in anti-senescence and anti-inflammatory effects and possesses lower risks of tumorigenicity and immune rejection relative to stem cell-based therapy. Exosome-based therapy is regarded as an ideal alternative to stem cell-based therapy, offering a promise to achieve 'cell-free' tissue regeneration.

[Auditory response patterns of mouse primary auditory cortex to sound stimuli]

OBJECTIVE

To investigate the auditory response patterns of mouse primary auditory cortex (A1) neurons.

METHODS

In vivo cell-attached recordings and neural network modeling were performed to detect the changes in response patterns of A1 neurons of awake C57BL/6J mice to sound stimulation with varying lengths. A1 neuron signals were recorded for 216 neurons in 20 awake mice using a target sound stimulation sequence, and the classification and response characteristics of A1 neuron response patterns were examined using post-stimulus spike time histograms. To simulate the diversity of the A1 neuron response patterns, an A1 neuron model was established based on the Wilson-Cowan model and integral-firing model. The neuron connection weight parameters in the model were calculated by examining the micro loop structure of the pyramidal neurons, parvalbumin neurons, and somatostatin neurons in the A1 region, and the A1 neural network information coding model was constructed.

RESULTS

The Onset response neurons only had fast spike response within 10 to 40 ms after the beginning of noise stimulation (122 neurons). The Sustained response neurons had spike response continuously during the noise stimulation (26 neurons). The On-off response neurons had fast spike response after the beginning and the end of noise stimulation (40 neurons). The Offset response neurons only had fast spike response within 10 to 40 ms after the end of noise stimulation (22 neurons). In the neural network model, the Onset peak neural activities of A1 pyramidal neurons, parvalbumin neurons, and somatostatin neurons were 0.7483, 0.5236 and 0.9427, respectively, and their response half peak widths were 18.5 ms, 12 ms and 31 ms during the 100 ms noise stimulation, respectively. By changing the feedforward excitation and synaptic inhibition time constants in the model, the neurons generated numerous different types of spike train.

CONCLUSION

The auditory response of mouse A1 neurons to sound stimuli shows mainly the Onset, Sustained, On-off, and Offset response patterns.

Otoacoustic emission and its application in anesthesia

OBJECTIVE

An otoacoustic emission (OAE) is a low-level sound emitted by the cochlea. OAEs are able to objectively evaluate the auditory perception and reflect the functional status of the auditory system. With the characteristics of non-invasiveness, high reliability, and easy manipulation, OAEs have gained wide popularity in clinical audiology and anesthesiology. This review aims to summarize the application of OAE in anesthesia.

MATERIALS AND METHODS

This study collected data from the databases Web of Science-Clarivate Analytics, PubMed, and Google Scholar in English, covering research in the last 40 years. The keywords were defined as anesthesia, cochlea, OAEs, distortion product otoacoustic emissions, transient evoked otoacoustic emissions, bispectral index, auditory evoked potentials, and depth of anesthesia. Documents that matched defined keywords were selected and reviewed.

RESULTS

Research showed that the types and doses of anesthetic drugs impacted OAEs. Ketamine-based anesthesia has a greater effect on OAE sensitivity over time compared to isoflurane. A higher dose of ketamine-xylazine significantly reduced the amplitude of OAEs. According to those characteristics, OAEs could be used as an objective evaluation method for the effect of anesthetics and have great potential to be applied for anesthetic drug dose control during surgery. OAEs also have been used to detect the cochlear function during anesthesia, which may cause irreversible damage to the cochlea.

CONCLUSIONS

Studies reported that OAEs have been used in anesthesia. However, the existing studies have mainly focused on the influence of anesthetic types or dosages on OAEs. Considering the characteristics of OAEs, such as a convenient measurement, less susceptibility to interference, and fast detection speed, the application of OAE has a great potential in the anesthesia field.

P-378 Effect of luteinized unruptured follicle on the pregnancy outcomes of single high-quality frozen-thawed blastocyst transfer cycles

Study question

Does luteinized unruptured follicle affect the clinical outcome of natural cycles for single high-quality frozen-thawed blastocyst transfer (FBT) cycles?

Summary answer

Luteinized unruptured follicle negatively affects the pregnancy outcomes of single high-quality FBT.

What is known already

Recent evidence revealed that natural ovulation cycle with a corpus luteum for frozen-thawed embryo transfer is superior to hormone replacing therapy cycle in preventing early miscarriage and preeclampsia. However, it remains controversial whether a luteinized unruptured follicle of the natural cycle affect the pregnancy outcomes of FBT.

Study design, size, duration

This was a retrospective cohort study comparing the pregnancy outcomes of singe high-quality FBT among 283 cases of LUF cycles and 1083 cases of ovulation cycles between January 2015 to December 2020 in a private fertility center. The study was approved by the hospital's Ethics Committee.

Participants/materials, setting, methods

A natural cycle for FBT was performed for all included patients, and was categorized into LUF or ovulation group based on the continuously monitoring of transvaginal ultrasound. Pregnancy outcomes were compared between the two groups. Logistic regression analysis was performed to adjust for important confounders. P &lt; 0.05 was considered statistically significant.

Main results and the role of chance

Compared to ovulation group, the LUF group was associated with higher proportion of female indication of IVF treatment. There were no statistically significant differences regarding the parental age at oocyte retrieval, body mass index (BMI), cycle rank, infertility duration, proportion of nulliparity and fertilization method, endometrial thickness, and estrogen levels. P levers were higher in the ovulation group than those of LUF (P =0.028). Logistic regression indicated that after controlling for potential confounders, ovulation group was associated with higher incidence of ongoing pregnancy (aOR 1.460, 95% CI: 1.107-1.924) and live birth (aOR 1.455, 95% CI: 1.102-1.919). Ovulation group also had higher clinical pregnancy rate (aOR 1.255, 95% CI: 0.952-1.656) and lower early miscarriage rate (aOR 0.654, 95% CI: 0.394-1.087), but not reach statistical significance. Our results suggested that LUF negatively affected pregnancy outcomes of single high-quality FBT.

Limitations, reasons for caution

The primary limitation of this study was its retrospective nature, and it was difficult to distinguish some confounding factors.

Wider implications of the findings

Clinicians should counsel couples about the negative effect of LUF on the pregnancy outcome of FBT, particularly for those with few high-quality embryos.

Trial registration number

2018YFC1003900/2018YFC1003904, SZSM201502035

P-620 Hormone replacement therapy with GnRH agonist pretreatment improves pregnancy outcomes in patients with previous intrauterine adhesions

Study question

Is there an optimal endometrial preparation protocol of frozen-thawed embryo transfer (FET) for patients with history of intrauterine adhesions (IUAs)?

Summary answer

Hormone replacement therapy with GnRH agonist pretreatment (HRT+GnRHa) is superior to conventional HRT protocol to improve pregnancy outcomes in patients with IUAs.

What is known already

FET follow hysteroscopic adhesiolysis or therapeutic treatment is being widely adopted in patients with IUAs. Proper endometrial preparation plays a key role to maximize IVF success rate and improve pregnancy results. However, it remains unclear whether there is an optimal endometrial preparation protocol for patients with history of IUAs.

Study design, size, duration

This was a retrospective cohort study of 1002 FET cycles with history IUAs in our fertility center between January 2015 to December 2020. The study was approved by the hospital's Ethics Committee.

Participants/materials, setting, methods

Eight hundred and forty-two conventional HRT cycles and 160 HRT+GnRHa cycles met the inclusion criteria were enrolled. Pregnancy outcomes were compared between the two groups. Logistic regression analysis was performed to adjust for important confounders. P &lt; 0.05 was considered statistically significant.

Main results and the role of chance

The HRT+GnRHa group was associated with higher cycle rank (1.79 vs 2.17, P =0.026) and longer infertility duration (3.04 vs 3.69, P =0.000) compared with conventional HRT group. While the latter had a higher proportion of blastocyst embryo transferred (P =0.024). There were no statistically significant differences regarding the parental age at oocyte retrieval, body mass index (BMI), number of total embryos transferred and top embryo transferred, proportion of nulliparity, indication of IVF treatment and fertilization method, and endometrial thickness. Logistic regression indicated that after controlling for potential confounders, the HRT+GnRHa group achieved higher incidence of clinical pregnancy (aOR 1.474, 95% CI: 1.002-2.170, P =0.049), ongoing pregnancy (aOR 1.823, 95% CI: 1.207-2.753, P =0.004), and live birth (aOR 1.975, 95% CI: 1.306-2.988, P =0.000) than the conventional HRT group. The miscarriage rate was comparable between the two groups (aOR 0.613, 95% CI: 0.293-1.283, P =0.194). Our results suggested that HRT+GnRHa is over conventional HRT protocol to improve pregnancy outcomes of patients with previous IUAs.

Limitations, reasons for caution

The primary limitation of this study was its retrospective nature, and it was difficult to distinguish some confounding factors. Besides, there was no grading of IUA severity as most adhesion separation surgeries were not performed in our hospital, and the detailed medical history was not available.

Wider implications of the findings

Our study offers evidence for the superiority of HRT with GnRH-a pretreatment to conventional HRT protocol in improving the pregnancy prognosis of patients with previous IUAs. Our finding deserves further confirmation in clinical practice.

Trial registration number

2018YFC1003900/2018YFC1003904, SZSM201502035

Transtibial pull-out repair of lateral meniscus posterior root is beneficial for graft maturation after anterior cruciate ligament reconstruction: a retrospective study

PURPOSE

To determine the repair of LMPR lesions would improve the ACL graft maturation.

METHOD

A total of 49 patients underwent ACL reconstruction were included in this study. Patients were furtherly sub-grouped according to the status of LMPR: intact (17), repair (16) and resected (16). Assessments performed pre- and 2 years post-operatively included patients-reported scores and arthrometer side-to-side difference. Magnetic resonance imaging was used 2 years after the surgery to compare the lateral meniscal extrusion (LME), anterior tibial subluxation of the medial compartment (ATSMC), anterior tibial subluxation of the lateral compartment (ATSLC), the difference of ATSMC and ATSLC, and signal/noise quotient (SNQ) of ACL graft.

RESULTS

In LMPR resected group, it showed greater post-operative ATSMC-ATSLC difference when compared with pre-operatively (P = 0.006) and with the other 2 groups (intact: P = 0.031; repair: P = 0.048). SNQ of ACL graft was higher in LMPR resected group than those in LMPR intact (P = 0.004) and repair group (P = 0.002). The LMPR repair group showed significant reduction in LME post-operatively (P = 0.001). Post-operative measures on ATSLC-ATSMC difference (β = 0.304, P = 0.049) and LME (β = 0.492, P = 0.003) showed significant association with graft SNQ.

CONCLUSIONS

Transtibial repair of LMPR concomitant with ACL reconstruction restored translational stability, reduced meniscus extrusion, making it beneficial for ACL graft maturation.

Menopausal hormone therapy: what are the problems in the perception of Chinese physicians?

OBJECTIVE

This study aimed to investigate Chinese physicians' perception and attitudes toward menopausal hormone therapy (MHT).

METHODS

This nationwide online survey was conducted in China. Physicians registered in the WeChat groups of the Gynecological Endocrinology Committee of China's Maternal and Child Health Care Association received a message invitation to complete this anonymous online survey from April 2020 to July 2020. Physicians' knowledge of and attitudes toward MHT were surveyed.

RESULTS

In total, 4672 questionnaires were submitted; only completed questionnaires could be submitted. The message was sent to 6021 doctors, so the response rate was 77.6%. Overall, 77.9-92.9% of physicians knew the common indications and contraindications to MHT. Additionally, 90.6%, 85.4%, 80.7% and 37.5% of physicians thought that MHT would increase the risk of venous thrombosis, breast cancer, endometrial cancer and weight gain, respectively. In total, 58.1% of the physicians mistakenly believed that a sex hormone test was one of the necessary examinations to reassess MHT prescription during follow-up visits. We found that 68.5% of physicians would consider using MHT themselves or recommend MHT to their partners in the future, and 11.4% were currently using MHT.

CONCLUSIONS

Most Chinese physicians have basic knowledge of MHT. Their misunderstandings about MHT mainly centered on the risks of endometrial cancer, weight gain and the necessary examinations during follow-up visits. These misunderstandings need to be clarified in future professional training programs.

Femur-tibia angle and patella-tibia angle: new indicators for diagnosing anterior cruciate ligament tears in magnetic resonance imaging

Background

Femur-tibia angle (FTA) and patella-tibia angle (PTA) are two MRI measurements that reflect the rotation of the knee joint. The purposes of this study were to assess whether FTA and PTA are associated with ACL tear and to explore their roles in ACL tear diagnosis.

Methods

FTA, PTA, ACL angle and anterior tibial subluxation were compared between the two matched groups: ACL tear group and control group (each n = 20). Diagnostic performance was evaluated in a consecutive 120-patient cohort who underwent MR imaging of the knee and subsequently had arthroscopy. Different measurements were assessed by area under the curve (AUC) of receiver operating characteristic (ROC) curve.

Results

FTA and PTA increased significantly in ACL tears group when compared to the control group (4.79 and 7.36 degrees, respectively, p < 0.05). In distinguishing complete ACL tear, ACL angle had the highest AUC of 0.906 while AUC of PTA and FTA were 0.849 and 0.809. The cutoff of FTA was 80 degrees with a sensitivity of 82% and specificity of 68%, while the cutoff of PTA was 91 degrees with a sensitivity of 82% and specificity of 74%. In distinguishing partial ACL tear, FTA and PTA had the highest AUCs of 0.847 and 0.813, respectively. The calculated cutoff of FTA was 84 degrees with a sensitivity of 90% and specificity of 81%, while the cutoff of PTA was 92 degrees with a sensitivity of 80% and specificity of 77%.

Conclusion

FTA and PTA increased when ACL tears and they might be valuable in diagnosing ACL tears, especially in distinguishing partial ACL tear from intact ACL.

A clinical model for predicting knee replacement in early-stage knee osteoarthritis: data from osteoarthritis initiative

BACKGROUND

Knee osteoarthritis (OA) progresses in a heterogeneous way, as a majority of the patients gradually worsen over decades while some undergo rapid progression and require knee replacement. The aim of this study was to develop a predictive model that enables quantified risk prediction of future knee replacement in patients with early-stage knee OA.

METHODS

Patients with early-stage knee OA, intact MRI measurements, and a follow-up time larger than 108 months were retrieved from the Osteoarthritis Initiative database. Twenty-five candidate predictors including demographic data, clinical outcomes, and radiographic parameters were selected. The presence or absence of knee replacement during the first 108 months of the follow-up was regarded as the primary outcome. Patients were randomly divided into derivation and validation groups in the ratio of three to one. Nomograms were developed based on multivariable logistic regressions of derivation group via R language. Those models were further tested in the validation group for external validation.

RESULTS

A total of 839 knees were enrolled, with 98 knees received knee replacement during the first 108 months. Glucocorticoid injection history, knee OA in the contralateral side, extensor muscle strength, area of cartilage deficiency, bone marrow lesion, and meniscus extrusion were selected to develop the nomogram after multivariable logistic regression analysis. The bias-corrected C-index and AUC of our nomogram in the validation group were 0.804 and 0.822, respectively.

CONCLUSION

Our predicting model provided simplified identification of patients with high risk of rapid progression in knee OA, which showed adequate predictive discrimination and calibration.

KEY POINTS

• Knee OA progresses in a heterogeneous way and rises to a challenge when making treatment strategies. • Our predicting model provided simplified identification of patients with high risk of rapid progression in knee OA.

A comparative evaluation of chemical composition and antimicrobial activities of essential oils extracted from different chemotypes of Cinnamomum camphora (L.) Presl

The purpose of this study is to determine the chemical composition of the essential oils of Cinnamomum camphora (L.) Presl leaves (CCPL) from 5 different habitats in China by GC-MS, and to evaluate their antimicrobial activities against 3 foodborne pathogens, using a paper disc diffusion method. A total of 30 compounds were identified with a predominance of oxygenated monoterpenes, including linalool (42.65%-96.47%), eucalyptol (39.07%-55.35%) and camphor (26.08%) as well as monoterpene hydrocarbons such as sabinene (6.18%-12.93%) and α-terpineol (8.19%-13.81%). Through cluster analysis, CCPL from 5 different habitats can be well divided into 2 categories. Combining with principal component analysis, the habitats can be better correlated with the chemical constituents of the essential oils. The antimicrobial activities of 5 extracted essential oils against 2 gram-negative bacteria and one gram-positive bacteria were assessed. It showed that the essential oil extracted from the CCPL harvested in Jinxi had the strongest antibacterial property. The results of this study provided basis for resource identification of CCPL and quality difference identification of essential oils. Research on the antibacterial properties of several pathogenic strains has proved its application value as a natural food preservative.

Alcohol Withdrawal Is Associated With Worse Outcomes in Patients Undergoing Primary Total Knee or Total Hip Arthroplasty

BACKGROUND

Alcohol withdrawal (AW) syndrome is an independent risk factor for postoperative complications. This study aims to evaluate the influence of AW on perioperative outcomes in patients who underwent primary total knee (TKA) or total hip arthroplasty (THA).

METHODS

We used the National Inpatient Sample database to identify patients undergoing TKA/THA from 2003 to 2014. The primary exposure of interest was AW. Multivariable adjusted models were used to evaluate the association of AW with in-hospital medical complications, surgical complications, mortality, cost, and length of stay (LOS) in patients undergoing TKA/THA.

RESULTS

There were 2,971,539 adult hospitalizations for THAs and 6,367,713 hospitalizations for TKAs included in the present study, among which 0.14% of AW for THA patients and 0.10% of AW for TKA patients. Multivariable adjustment analysis suggested that AW was associated with an increased risk of medical complications (odds ratio [OR] 2.08, 95% confidence interval [CI] 1.79-2.42, P < .0001), surgical complications (OR 1.75, 95% CI 1.51-2.03, P < .0001), and had 4.79 times increase of in-hospital mortality, 26% increase of total cost, and 53% increase of LOS in THA procedures. For TKA procedures, AW was also associated with increased risk of medical complications (OR 3.14, 95% CI 2.78-3.56, P < .0001), surgical complications (OR 2.07, 95% CI 1.82-2.34, P < .0001) and 4.24 times increase of in-hospital mortality, 29% increase of total cost, and 58% increase of LOS after multivariable adjustment.

CONCLUSION

AW is associated with increased risk of in-hospital mortality, medical and surgical complications. Proactive surveillance and management of AW may be important in improving outcomes in patients who underwent THA and TKA procedure.

Deliver protein across bio-barriers via hexa-histidine metal assemblies for therapy: a case in corneal neovascularization model

Because of their high specificity and low side effects, protein drugs possess a substantial global market. However, the low bioavailability of protein is still a major obstacle to their expanded applications, which is expected to be answered with proper protein formulations. Taking corneal neovascularization (CNV) as an example, we demonstrated a co-assembled system of hexa-histidine and Ava (Avastin) with metal ions (HmA@Ava) could cross the cornea, the most important bio-barrier during the treatment of most diseases of the anterior segment in clinics. We found that the nanosized HmA@Ava efficiently encapsulated Ava with impressive loading capacity without destroying the bioactivity of Ava and assisted Ava penetration through the corneal barriers to effectively inhibit CNV development in an alkali burn rat model with sustained and pH-dependent Ava release. Our results suggested that the co-assembled strategy of protein and HmA is a proper formulation to protein drugs, with promising penetration ability to deliver protein across bio-barriers, which could open a path for topical administration of protein drugs for treatment of various ocular diseases and hold enormous potential for delivery of therapeutic proteins not only for ocular diseases but also for other diseases that require protein treatment.

•

HmA@Ava can bring protein drug, Ava, across over the primary bio-barrier of the anterior segment ​and efficiently treat CNV.

•

HmA@Ava was nanoparticles, with impressive loading capacity without destroying bioactivity of Ava ​and strong pH-dependent release.

•

HmA can open a path for the treatment of eye diseases and hold huge potential to protein drugs to other diseases.

Three-dimensional morphological study of the proximal femur in Crowe type IV developmental dysplasia of the hip

Background

When performing femoral reconstruction in patients with Crowe type IV developmental dysplasia of the hip (DDH), anatomical deformity presents many technical challenges to orthopedic surgeons. The false acetabulum is suggested to influence load transmission and femoral development. The aim of this study was to describe the morphological features of dysplastic femurs in Crowe type IV DDH and further evaluate the potential effect of the false acetabulum on morphological features and medullary canal of Crowe type IV femurs.

Methods

We analyzed preoperative computed tomography scans from 45 patients with 51 hips (25 hips without false acetabulum in the IVa group and 26 hips with false acetabulum in the IVb group) who were diagnosed with Crowe type IV DDH and 30 normal hips in our hospital between January 2009 and January 2019. Three-dimensional reconstruction was performed using Mimics software, and the coronal femoral plane was determined to evaluate the following parameters: dislocation height, dislocation ratio, height of the femoral head (FH), height of the greater trochanter (GT), GT–FH height discrepancy, height of the isthmus, neck-shaft angle, femoral offset and anteversion of the femoral neck. The mediolateral (ML) width, anterolateral (AP) width and diameter of medullary canal of the proximal femur were measured on the axial sections. Further, canal flare index (CFI), metaphyseal-CFI and diaphyseal-CFI were also calculated.

Results

Compared with the normal femurs, the Crowe type IV DDH femurs had a higher femoral head, larger GT–FH height discrepancy, larger femoral neck anteversion, higher isthmus position and smaller femoral offset. Dislocation height and dislocation rate were significantly larger in the IVa DDH group (65.34 ± 9.83 mm vs. 52.24 ± 11.42 mm). Further, the IVb femurs had a significantly lower isthmus position, larger neck-shaft angle and smaller femoral neck anteversion than IVa femurs. The ML, AP canal widths and the diameter of medullary canal in both DDH groups were significantly smaller than the normal group. Dimensional parameters of IVa femurs were also narrower than IVb femurs in most sections, but with no difference at the level of isthmus. According to the CFIs, the variation of proximal medullary canal in IVb femurs was mainly located in the diaphyseal region, while that in IVa femurs was located in the whole proximal femur.

Conclusions

High dislocated femurs are associated with more anteverted femoral neck, smaller femoral offset and narrower medullary canal. Without stimulation of the false acetabulum, IVa DDH femurs were associated with higher dislocation and notably narrower medullary canal, whose variation of medullary canal was located in the whole proximal femur.

Nanosecond pulsed electric fields prime mesenchymal stem cells to peptide ghrelin and enhance chondrogenesis and osteochondral defect repair in vivo

Mesenchymal stem cells (MSCs) are important cell sources in cartilage tissue development and homeostasis, and multiple strategies have been developed to improve MSCs chondrogenic differentiation with an aim of promoting cartilage regeneration. Here we report the effects of combining nanosecond pulsed electric fields (nsPEFs) followed by treatment with ghrelin (a hormone that stimulates release of growth hormone) to regulate chondrogenesis of MSCs. nsPEFs and ghrelin were observed to separately enhance the chondrogenesis of MSCs, and the effects were significantly enhanced when the bioelectric stimulation and hormone were combined, which in turn improved osteochondral tissue repair of these cells within Sprague Dawley rats. We further found that nsPEFs can prime MSCs to be more receptive to subsequent stimuli of differentiation by upregulated Oct4/Nanog and activated JNK signaling pathway. Ghrelin initiated chondrogenic differentiation by activation of ERK1/2 signaling pathway, and RNA-seq results indicated 243 genes were regulated, and JAK-STAT signaling pathway was involved. Interestingly, the sequential order of applying these two stimuli is critical, with nsPEFs pretreatment followed by ghrelin enhanced chondrogenesis of MSCs in vitro and subsequent cartilage regeneration in vivo, but not vice versa. This synergistic prochondrogenic effects provide us new insights and strategies for future cell-based therapies.

Bioactive Silk Fibroin-Based Hybrid Biomaterials for Musculoskeletal Engineering: Recent Progress and Perspectives

Musculoskeletal engineering has been considered as a promising approach to customize regenerated tissue (such as bone, cartilage, tendon, and ligament) via a self-healing performance. Recent advances have demonstrated the great potential of bioactive materials for regenerative medicine. Silk fibroin (SF), a natural polymer, is regarded as a remarkable bioactive material for musculoskeletal engineering thanks to its biocompatibility, biodegradability, and tunability. To improve tissue-engineering performance, silk fibroin is hybridized with other biomaterials to form silk-fibroin-based hybrid biomaterials, which achieve superior mechanical and biological performance. Herein, we summarize the recent development of silk-based hybrid biomaterials in musculoskeletal tissue with reasonable generalization and classification, mainly including silk fibroin-based inorganic and organic hybrid biomaterials. The applied inorganics are composed of calcium phosphate, graphene oxide, titanium dioxide, silica, and bioactive glass, while the polymers include polycaprolactone, collagen (or gelatin), chitosan, cellulose, and alginate. This article mainly focuses on the physical and biological performances both in vitro and in vivo study of several common silk-based hybrid biomaterials in musculoskeletal engineering. The timely summary and highlight of silk-fibroin-based hybrid biomaterials will provide a research perspective to promote the further improvement and development of silk fibroin hybrid biomaterials for improved musculoskeletal engineering.

[Study on the feature of cortical auditory evoked potential under different auditory tasks in cochlear implant children]

Objective: To investigate the variation regularity and influencing factors of cortical auditory evoked potential (CAEP) evoked by pure tone, syllable and tone stimuli in cochlear implant (CI) children. Methods: Cortical auditory evoked potential (CAEP) responses were collected from 46 CI children in the sound field. Pure tones with frequencies of 1 kHz and 2 kHz were used as the standard and the deviant respectively in the pure tone stimulation condition. The Chinese Mandarin tokens/ba/-/pa/and/ba1/-/ba4/pairs were used as the stimuli respectively in the syllable and tone stimulation condition. The latency, amplitude and presence rate of P1 and mismatch negative(MMN) were obtained and the correlation between the difficulty of auditory task, the age of hearing month, the duration of severe-profound hearing loss, the wearing history of hearing aid before CI, the hearing threshold of the better ear before CI and the latency and amplitude of P1 and MMN were analyzed. All statistical analyses and figures were conducted using SPSS 25.0. Results: The P1 presence rate of pure tone, syllable and tone group was 100% (17/17), 100% (13/13) and 75.0% (12/16), respectively, with significant difference (χ²=8.214, P=0.016). There was significant difference between pure tone group and tone group (χ²=4.836, P=0.028), but no significant difference between pure tone group and syllable group, syllable group and tone group. The MMN presence rate of pure tone, syllable and tone group was 94.1% (16/17), 84.6% (11/13) and 62.5% (10/16), respectively, but no significant difference among the three groups with different auditory tasks(χ²=0.066, P=0.066). No significant difference was observed among the three groups of different auditory tasks in the latency and amplitude of P1 and MMN. Multiple linear regression analysis showed that the latency of P1 was positively correlated with the difficulty of auditory task and the hearing threshold of the better ear before CI, and negatively correlated with hearing age and the history of hearing aid before CI. The latency of MMN was positively correlated with the difficulty of auditory task, and negatively correlated with hearing age. Conclusions: The P1 presence rate of pure tone auditory task is significantly higher than that of tone auditory task. The difficulty of auditory task, hearing age, the history of hearing aid before CI, and the hearing threshold of the better ear before CI has significant effects on the P1 latency. The difficulty of auditory task and hearing age has significant effects on the MMN latency.

P–194 Impact of cryopreservation duration on pregnancy outcomes of vitrified-warmed blastocysts transfer using an open-device system

Study question

Is there a negative effect of long-term cryopreservation upon pregnancy outcomes after transfer of vitrified-warmed blastocysts stored in an open-device system?

Summary answer

Prolonged cryopreservation of vitrified blastocysts up to 24 months increased the incidences of clinical pregnancy, ongoing pregnancy, and live birth, while decreased early miscarriage rate.

What is known already

Vitrification is adopted as the dominant approach for cryopreservation of human oocytes and embryos. However, little is known about the potential effect of prolonged storage after vitrification on the genomic integrity and metabolism of embryos. Several studies have sought to decipher the effect of cryopreservation duration on IVF pregnancy outcomes, but few were confined to vitrification and the results were inconsistent.

Study design, size, duration

This retrospective study included 6722 patients undergoing their first vitrified-warmed blastocyst transfer (VBT) cycles from January 2015 to June 2019 in a single fertility center in South China. The study was approved by the hospital’s Ethics Committee.

Participants/materials, setting, methods

A total of 6722 eligible patients were divided into five groups according to the storage duration after vitrification: Group I: 0–3 months; Group II: 3–6 months; Group III: 6–12 months; Group IV: 12–24 months; Group V: 24–36 months. The IVF pregnancy outcomes were compared between groups. Multivariate logistic regression was conducted to evaluate the independent effect of storage duration on pregnancy outcomes.

Main results and the role of chance

The odds of clinical pregnancy outcomes were similar from Group 1 to 4. However, the chance of clinical pregnancy (Group 1 as reference; Group 2: adjusted odds ratio (aOR)= 1.04, 95% CI 0.93–1.17; Group 3: aOR = 1.02, 95% CI 0.84–1.25; Group 4: aOR = 0.93, 95% CI 0.66–1.31; Group 5: aOR = 0.54, 95% CI 0.38–0.76) , ongoing pregnancy (Group 2: aOR=0.99, 95% CI 0.89–1.11; Group 3: aOR = 0.94, 95% CI 0.77–1.14; Group 4: aOR = 0.87, 95% CI 0.62–1.22; Group 5: aOR = 0.41, 95% CI 0.29–0.60), and live birth rate (Group 2: aOR=1.00, 95% CI 0.89–1.12; Group 3: aOR = 0.98, 95% CI 0.81–1.19; Group 4: aOR = 0.91, 95% CI 0.65–1.27; Group 5: aOR = 0.46, 95% CI 0.32–0.66) significantly decreased, while the early miscarriage rate (Group 2: aOR=1.11, 95% CI 0.92–1.35; Group 3: aOR =1.25, 95% CI 0.92–1.70; Group 4: aOR = 1.33, 95% CI 0.77–2.31; Group 5: aOR = 2.42, 95% CI 1.36–4.31) significantly increased as the storage duration increased up to 24–36 months.

Limitations, reasons for caution

The primary limitation of this study was its retrospective nature. Besides, as all these data come from a single IVF treatment center, the results should be confirmed by a larger multicenter study.

Wider implications of the findings: Our study provides more evidence about the negative impact of long-term storage of vitrified embryos on the clinical outcome. Clinicians should adapt FET strategies based on the embryo storage duration.

Trial registration number

Not applicable