Isolated non-immune mediated second-degree atrioventricular block in fetus: natural history and predictive factors for spontaneous recovery

OBJECTIVES

To uncover the clinical course of fetal isolated non-immune mediated second-degree AVB and determine the factors associated with the spontaneous recovery for fetal non-immune second-degree atrioventricular block (AVB).

METHODS

A total of 20 fetuses with isolated, non-immune mediated second-degree AVB were prospectively recruited between 2014 and 2022. These fetuses were divided into the spontaneous recovery group (n=12) and the non-spontaneous recovery group (n=8). Maternal and fetal basic characteristics, intrauterine and postnatal outcomes were compared between groups.

RESULTS

Twelve fetuses restored 1:1 atrioventricular conduction in utero and did not recur during the postnatal follow-up period. The residual eight fetuses maintained as second-degree AVB and six of them were aborted due to parental request in utero. Of the two live children with second-degree AVB, one of them progressed to complete AVB at the latest follow up at the age of 34 months, but without any symptoms, heart enlargement or dysfunction. The residual one progressed to complete AVB and was finally diagnosed with type 2 long-QT syndrome. Fetuses in the spontaneous recovery group presented with earlier gestational age at diagnosis (20.0[17.0-26.0] vs. 24.5[18.0-35.0] weeks, p=0.004) and higher atrial rate (147[130-160] vs 138.00[125.00-149.00] bpm, p=0.006) in comparison with the non-spontaneous recovery group. A cut-off value of 22.5 weeks of gestational age and 144 bpm of atrial rate at diagnosis could predict the failure of spontaneous recovery, with sensitivities of 87.5%, 75%, and specificities of 92.0%, 87.5%, respectively.

CONCLUSIONS

The outcome of fetal non-immune second-degree AVB was favorable. Earlier gestational age at diagnosis and higher atrial rate were related to spontaneous reversion for isolated non-immune-mediated second-degree AVB. However, prenatal gene test should be performed for those with persistent AVB to exclude the heritable disorders including LQTS. These findings may provide important references for clinical management and prenatal counseling. This article is protected by copyright. All rights reserved.

Smart nanogels for cancer treatment from the perspective of functional groups

Introduction: Cancer remains a significant health challenge, with chemotherapy being a critical treatment modality. However, traditional chemotherapy faces limitations due to non-specificity and toxicity. Nanogels, as advanced drug carriers, offer potential for targeted and controlled drug release, improving therapeutic efficacy and reducing side effects. Methods: This review summarizes the latest developments in nanogel-based chemotherapy drug delivery systems, focusing on the role of functional groups in drug loading and the design of smart hydrogels with controlled release mechanisms. We discuss the preparation methods of various nanogels based on different functional groups and their application in cancer treatment. Results: Nanogels composed of natural and synthetic polymers, such as chitosan, alginate, and polyacrylic acid, have been developed for chemotherapy drug delivery. Functional groups like carboxyl, disulfide, and hydroxyl groups play crucial roles in drug encapsulation and release. Smart hydrogels have been engineered to respond to tumor microenvironmental cues, such as pH, redox potential, temperature, and external stimuli like light and ultrasound, enabling targeted drug release. Discussion: The use of functional groups in nanogel preparation allows for the creation of multifunctional nanogels with high drug loading capacity, controllable release, and good targeting. These nanogels have shown promising results in preclinical studies, with enhanced antitumor effects and reduced systemic toxicity compared to traditional chemotherapy. Conclusion: The development of smart nanogels with functional group-mediated drug delivery and controlled release strategies represents a promising direction in cancer therapy. These systems offer the potential for improved patient outcomes by enhancing drug targeting and minimizing adverse effects. Further research is needed to optimize nanogel design, evaluate their safety and efficacy in clinical trials, and explore their potential for personalized medicine.

Telocinobufagin inhibits osteosarcoma growth and metastasis by inhibiting the JAK2/STAT3 signaling pathway

Osteosarcoma is the most common primary bone malignancy in children and adolescents; it exhibits rapid growth and a high metastatic potential and may thus lead to relatively high mortality. The JAK2/STAT3 signaling pathway, which plays a critical role in the occurrence and development of osteosarcoma, is a potential target for the treatment of osteosarcoma. Here, we identified the natural product telocinobufagin (TCB), which is a component isolated from toad cake, as a potent candidate with anti-osteosarcoma effects. TCB inhibited osteosarcoma cell growth, migration, invasion and induced cancer cell apoptosis. Mechanistically, TCB specifically inhibited the JAK2/STAT3 signaling pathway. More importantly, TCB significantly suppressed tumor growth and metastasis in an osteosarcoma xenograft animal model. Moreover, TCB also showed strong inhibitory effects in other cancer types, such as lung cancer, liver cancer, colon cancer, breast cancer and gastric cancer. Hence, our study reveals TCB as a potent anti-osteosarcoma therapeutic agent that inhibits the JAK2/STAT3 signaling pathway.

First-in-Maintenance Therapy for Localized High-Grade Osteosarcoma: An Open-Label Phase I/II Trial of the Anti-PD-L1 Antibody ZKAB001

PURPOSE

We investigated the safety and preliminary efficacy of anti-PD-L1 antibody (ZKAB001) as maintenance therapy for localized patients with high-grade osteosarcoma to reduce the risk of recurrence and metastasis.

PATIENTS AND METHODS

This open-label Phase I/II study was divided into dose-escalation Phase I and expansion Phase II. Phase I used a 3+3 design with ZKAB001 at three escalating doses ranging: 5, 10, 15 mg/kg every 2 weeks in 9 patients with localized high-grade osteosarcoma and Phase II tested 10 mg/kg in 12 patients for up to 24 cycles. Primary endpoints were safety and tolerability assessed using CTCAE4.0.3.

RESULTS

Between October 2018 and 2019, 21 eligible patients were enrolled and accepted ZKAB001 treatment: 9 in the dose-escalation phase, and 12 in expansion phase. Six patients with disease progression withdrew from this study and follow-up is ongoing. The MTD was not defined in Phase I. All doses had a manageable safety profile. The recommended dose in Phase II was set at 10 mg/kg. Most frequent immune-related adverse events were thyroiditis (76.2%) and dermatitis (42.9%). Only 1 (4.8%) of 21 patients had a Grade 3 skin rash. The median 3-year event-free survival (EFS) and overall survival (OS) were not established; however, 24-month EFS was 71.4% (95% confidence interval, 47.2-86.0) and 2-year OS was 100%. Preliminary efficacy data showed EFS benefits in patients with PD-L1 positive or an MSI-H sub-population.

CONCLUSIONS

Switching to maintenance using ZKAB001 showed an acceptable safety profile and provided preliminary evidence of clinical activity in localized patients with osteosarcoma.

Multi-omics analysis identifies osteosarcoma subtypes with distinct prognosis indicating stratified treatment

Osteosarcoma (OS) is a primary malignant bone tumor that most commonly affects children, adolescents, and young adults. Here, we comprehensively analyze genomic, epigenomic and transcriptomic data from 121 OS patients. Somatic mutations are diverse within the cohort, and only TP53 is significantly mutated. Through unsupervised integrative clustering of the multi-omics data, we classify OS into four subtypes with distinct molecular features and clinical prognosis: (1) Immune activated (S-IA), (2) Immune suppressed (S-IS), (3) Homologous recombination deficiency dominant (S-HRD), and (4) MYC driven (S-MD). MYC amplification with HR proficiency tumors is identified with a high oxidative phosphorylation signature resulting in resistance to neoadjuvant chemotherapy. Potential therapeutic targets are identified for each subtype, including platinum-based chemotherapy, immune checkpoint inhibitors, anti-VEGFR, anti-MYC and PARPi-based synthetic lethal strategies. Our comprehensive integrated characterization provides a valuable resource that deepens our understanding of the disease, and may guide future clinical strategies for the precision treatment of OS.

Applications of Nano/Micromotors for Treatment and Diagnosis in Biological Lumens

Natural biological lumens in the human body, such as blood vessels and the gastrointestinal tract, are important to the delivery of materials. Depending on the anatomic features of these biological lumens, the invention of nano/micromotors could automatically locomote targeted sites for disease treatment and diagnosis. These nano/micromotors are designed to utilize chemical, physical, or even hybrid power in self-propulsion or propulsion by external forces. In this review, the research progress of nano/micromotors is summarized with regard to treatment and diagnosis in different biological lumens. Challenges to the development of nano/micromotors more suitable for specific biological lumens are discussed, and the overlooked biological lumens are indicated for further studies.

Inhibition of sphingolipid metabolism in osteosarcoma protects against CD151-mediated tumorigenicity

Osteosarcoma is the most common primary bone tumor, with a poor prognosis owing to the lack of efficient molecular-based targeted therapies. Previous studies have suggested an association between CD151 and distinct consequences in osteosarcoma tumorigenicity. However, the potential of CD151 as a therapeutic target has not yet been sufficiently explored. Here, we performed integrated transcriptomic and metabolomic analyses of osteosarcoma and identified sphingolipid metabolism as the top CD151-regulated pathway. CD151 regulates sphingolipid metabolism primarily through SPTCL1, the first rate-limiting enzyme in sphingolipid biosynthesis. Mechanistically, depletion of CD151 enhanced c-myc polyubiquitination and subsequent degradation. c-myc is vital for the transcriptional activation of SPTLC1. Functionally, sphingolipid synthesis and the SPTLC1 inhibitor, myriocin, significantly suppressed the clonogenic growth of CD151-overexpression cells. Importantly, myriocin selectively restrained CD151-high expression tumor growth in preclinical patient-derived xenograft models. Collectively, these data establish that CD151 is a key mediator of sphingolipid metabolism and provide a new approach to developing novel CD151-based targeted therapies for osteosarcoma.

Abstract A037: TT-00420, a novel kinase inhibitor potentially benefiting c-Myc amplified/overexpressed osteosarcoma

Osteosarcoma (OS) is the most common bone tumor in pediatric patients, whose effective therapies are of great unmet medical needs, particularly for those of high-risk features. c-Myc, a well-known oncogene, is commonly amplified/overexpressed in OS patients, contributes to dismal prognosis and associates with lower 5-year overall survival rate, which is also confirmed by our retrospective analysis for the correlation between c-Myc gene amplification/overexpression and patient prognosis in our patient cohort. TT-00420, a clinical-stage small molecule targeting Aurora A/B, VEGFRs, FGFRs, JAKs and CSF1R, has demonstrated down-regulation on c-Myc expression in TNBC studies. Moreover, as reported, Aurora kinases and c-Myc regulate each other back and forth, triggering maintenance of the malignant state. In this study, we examined the efficacy of TT-00420 in c-Myc-amplified/overexpressed OS. In pre-clinical clonogenic assay, TT-00420 significantly inhibited the colony formation in c-Myc-overexpressed OS cell lines in a dose-dependent manner. In MNNG/HOS cell line, we demonstrated that TT-00420 dramatically suppressed Aurora kinase pathway and blunted c-Myc protein expression level, indicating TT-00420 might down-regulate c-Myc by Aurora kinases inhibition. In pre-clinical in-vivo efficacy studies, 143B cells were injected into the medullary cavity of the tibia to make the orthotopic OS xenograft model. With 15 mg/kg/day treatment of TT-00420, tumor growth was obviously inhibited as compared to vehicle group. Immunohistochemistry (IHC) analyses in tumors revealed that TT-00420-treated tumors exhibited increased apoptosis with upregulated expression of cleaved caspase 3 (CC3) and H2AX, and significantly decreased proliferations with raised expression of Ki67. Moreover, in a c-Myc-overexpressed OS patient-derived xenograft (PDX) model from a male pediatric patient, 15 mg/kg/day TT-00420 dramatically blunted the tumor growth with a TGI of 87.6%. In China, an investigator-initiated trial is currently ongoing to evaluate the safety and tolerability of TT-00420 in OS patients with c-Myc overexpression (ChiCTR2000036618). Taken together, TT-00420 depicted robust anti-tumor activity in c-Myc overexpressed OS both in vitro and in vivo with downregulation of c-Myc expression, indicating its potential as a novel monotherapy for OS patients with c-Myc overexpression. Future clinical trial result is of great expectation.

Citation Format: Yingqi Hua, Xiaoyan Qiang, Kai Tian, Yafei Jiang, Frank Wu, Peng Peng. TT-00420, a novel kinase inhibitor potentially benefiting c-Myc amplified/overexpressed osteosarcoma [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A037.

Detection and surveillance of circulating tumor cells in osteosarcoma for predicting therapy response and prognosis

Objective:

Osteosarcoma (OS) is an aggressive, highly metastatic, relatively drug-resistant bone tumor with poor long-term survival rates. The presence and persistence of circulating tumor cells (CTCs) in the peripheral blood are believed to be associated with treatment inefficiency and distant metastases. A blood-based CTC test is thus greatly needed for monitoring disease progression and predicting clinical outcomes. However, traditional methods cannot detect CTCs from tumors of mesenchymal origin such as OS, and research on CTC detection in mesenchymal tumors has been hindered for years.

Methods:

In this study, we developed a CTC test based on hexokinase 2, a metabolic function-associated marker, for the detection and surveillance of OS CTCs, and subsequently explored its clinical value. Twelve patients with OS were enrolled as the training cohort for serial CTC tests. Dynamic CTC counting, in combination with therapy evaluation and post-treatment follow-up, was used to establish a model for predicting post-chemotherapy evaluation and disease-free survival, and the model was further validated with a cohort of 8 patients with OS.

Results:

Two dynamic CTC number patterns were identified, and the resulting predictive model exhibited 92% consistency with the clinical outcomes. This model suggested that a single CTC test has similar predictive power to serial CTC analysis. In the validation cohort, the single CTC test exhibited 100% and 87.5% consistency with therapy response and disease-free survival, respectively.

Conclusions:

Our non-invasive test for detection and surveillance of CTCs enables accurate prediction of therapy efficiency and prognosis, and may be clinically valuable for avoiding inefficient therapy and prolonging survival.

Magnetic-Driven Hydrogel Microrobots Selectively Enhance Synthetic Lethality in MTAP-Deleted Osteosarcoma

Background: Drugs based on synthetic lethality have advantages such as inhibiting tumor growth and affecting normal tissue in vivo. However, specific targets for osteosarcoma have not been acknowledged yet. In this study, a non-targeted but controllable drug delivery system has been applied to selectively enhance synthetic lethality in osteosarcoma in vitro, using the magnetic-driven hydrogel microrobots.

Methods: In this study, EPZ015666, a PRMT5 inhibitor, was selected as the synthetic lethality drug. Then, the drug was carried by hydrogel microrobots containing Fe₃O₄. Morphological characteristics of the microrobots were detected using electron microscopy. In vitro drug effect was detected by the CCK-8 assay kit, Western blotting, etc. Swimming of microrobots was observed by a timing microscope. Selective inhibition was verified by cultured tumors in an increasing magnetic field.

Results: Genomic mutation of MTAP deletion occurred commonly in pan-cancer in the TCGA database (nearly 10.00%) and in osteosarcoma in the TARGET database (23.86%). HOS and its derivatives, 143B and HOS/MNNG, were detected by MTAP deletion according to the CCLE database and RT-PCR. EPZ015666, the PRMT5 inhibitor, could reduce the SDMA modification and inhibition of tumor growth of 143B and HOS/MNNG. The hydrogel microrobot drug delivery system was synthesized, and the drug was stained by rhodamine. The microrobots were powered actively by a magnetic field. A simulation of the selected inhibition of microrobots was performed and lower cell viability of tumor cells was detected by adding a high dose of microrobots.

Conclusion: Our magnetic-driven drug delivery system could carry synthetic lethality drugs. Meanwhile, the selective inhibition of this system could be easily controlled by programming the strength of the magnetic field.

Pectolinarigenin acts as a potential anti-osteosarcoma agent via mediating SHP-1/JAK2/STAT3 signaling

Signal transducer and activator of transcription 3 (STAT3) plays essential roles in cancer progression and has been considered as a promising target for cancer therapy. Here, we used a dual luciferase assay to identify that pectolinarigenin inhibited STAT3 transcriptional activity. Further, results showed pectolinarigenin inhibited constitutive and IL6 induced STAT3 signaling, diminished the accumulation of STAT3 in the nucleus, dimerization and blocked STAT3 DNA binding activity. Mechanism investigations indicated that pectolinarigenin disturbed the STAT3/DNMT1/HDAC1 complex formation in the promoter region of SHP-1, which reversely mediates STAT3 signaling, leading to the upregulation of SHP-1 expression in osteosarcoma. We also found pectolinarigenin significantly suppressed osteosarcoma growth, induced apoptosis. In addition, pectolinarigenin blocked tumor cells migration, invasion and reserved EMT phenotype. In spontaneous tibial injection and patient-derived xenograft models of osteosarcoma, we identified administration (i.p.) of pectolinarigenin (20 mg/kg/2 days and 50 mg/kg/2 days) blocked STAT3 activation and disturbed tumor growth and metastasis with superior pharmacodynamic properties. Taken together, our findings demonstrate that pectolinarigenin may be a candidate for osteosarcoma intervention linked to its STAT3 signaling inhibitory activity.

Immune Microenvironment in Osteosarcoma: Components, Therapeutic Strategies and Clinical Applications

Osteosarcoma is a primary malignant tumor that tends to threaten children and adolescents, and the 5-year event-free survival rate has not improved significantly in the past three decades, bringing grief and economic burden to patients and society. To date, the genetic background and oncogenesis mechanisms of osteosarcoma remain unclear, impeding further research. The tumor immune microenvironment has become a recent research hot spot, providing novel but valuable insight into tumor heterogeneity and multifaceted mechanisms of tumor progression and metastasis. However, the immune microenvironment in osteosarcoma has been vigorously discussed, and the landscape of immune and non-immune component infiltration has been intensively investigated. Here, we summarize the current knowledge of the classification, features, and functions of the main infiltrating cells, complement system, and exosomes in the osteosarcoma immune microenvironment. In each section, we also highlight the complex crosstalk network among them and the corresponding potential therapeutic strategies and clinical applications to deepen our understanding of osteosarcoma and provide a reference for imminent effective therapies with reduced adverse effects.

Highly efficient generation of narrowband terahertz radiation driven by a two-spectral-line laser in PPLN

We demonstrate record ∼0.9% efficiencies for optical conversion to narrowband (<1% relative bandwidth) terahertz (THz) radiation by strongly cascaded difference frequency generation. These results are achieved using a novel, to the best of our knowledge, laser source, customized for high efficiencies, with two narrow spectral lines of variable separation and pulse duration (≥250 ps). THz radiation generation in 5% MgO-doped periodically poled lithium niobate (PPLN) crystals of varying poling period was explored at cryogenic and room temperature operation as well as with different crystal lengths. This work addresses an increasing demand for high-field THz radiation pulses which has, up to now, been largely limited by low optical-to-THz radiation conversion efficiencies.

Correlation between Patient-Derived Xenograft Modeling and Prognosis in Osteosarcoma

Objective

To retrospectively analyze and compare the relationship between the success rate of patient‐derived xenograft (PDX) modeling of osteosarcoma and prognosis (3‐year overall survival rate and disease‐free survival rate) and incidence of lung metastasis.

Methods

The sample group consisted of 57 osteosarcoma patients with definite pathological diagnoses from Shanghai General Hospital from 2015–2017. PDX models in 57 patients were analyzed by retrospective analyses. Among the patients currently inoculated, 20 were tumorigenic in the PDX model, and 37 were nontumorigenic. According to the tumorigenicity of PDXs, the corresponding osteosarcoma patients were divided into two groups. The effects of clinically related indicators on the model were retrospectively compared. The patients were followed, and the 3‐year survival, 3‐year disease‐free survival (DFS), and lung metastasis rates were collected. The relationship between the modeling success and patient prognosis was investigated.

Results

In the chemotherapy‐treated group, the PDX modeling success rate was 17.4%, and in the nonchemotherapy group, the success rate was 47.1%. The success of PDX modeling was related to whether patients received chemotherapy. The success rate of PDX modeling is significantly reduced after receiving chemotherapy. The 3‐year overall survival rate of the PDX‐grafted group was 49.23%, and that of the PDX‐nongrafted group was 65.71%. There was a significant difference between the two groups, showing a strong negative correlation between the 3‐year survival rate and the success rate of the PDX model. The 3‐year disease‐free survival rate of the PDX‐grafted group was 29.54%. The 3‐year DFS of the PDX‐nongrafted group was 50.34%. There was a significant difference between the two groups. Lower grafted rates indicate a higher DFS rate. The incidence of lung metastasis in the PDX‐grafted group was 32.4%, and that in the nongrafted group was 13.1%. There was a significant difference between the two groups. The successful establishment of the PDX model indicates that patients are more likely to have lung metastases.

Conclusions

The success of PDX modeling often indicates poor prognosis (low 3‐year overall survival rate and disease‐free survival rate) and a greater possibility of lung metastasis. Therefore, PDX modeling in osteosarcoma patients can accurately predict the prognosis of patients and the risk of lung metastasis in advance to help us develop better therapeutic strategies.

Stabilization and sensory evaluation of calcium-enriched soymilk prepared using different chelating agents

It is generally acknowledged that calcium lactate (ca-lactate) fortification of soymilk to achieve the equivalent calcium level in cow’s milk (1.2 mg/g) causes instability in soymilk. In order to produce acceptable calcium-enriched soymilk with great stability, three different kinds of chelating agents were added, namely tripotassium citrate (TPC), trisodium citrate (TSC), and sodium hexametaphosphate (SHMP). In this study, the addition of ca-lactate was found to reduce the pH (6.62 to 5.37) and increase the particle diameter (268.66 to 1,222.81 nm) and sedimentation (0.19 to 8.75%) of soymilk. Meanwhile, the addition of TPC and TSC produced calcium-enriched soymilks with smaller particle diameter (295.21-452.22 nm and 297.61-461.80 nm) and lower sedimentation levels (0.25-1.55% and 0.26-1.58%). The pH of calcium-enriched soymilk was also increased when both chelating agents were added. The application of SHMP as a chelating agent was not as effective as TPC and TSC because the particle diameter (527.98-703.40 nm) and sedimentation level were still relatively higher (4.24-5.68%) than the unfortified soymilk. Even though both TPC and TSC showed no significant difference (P>0.05) in stability, the sensory evaluation showed different results. Soymilk with TSC added was saltier and sourer than samples with TPC added. The study recommends the use of TPC as the chelating agent in soymilk enriched with ca-lactate.

Anlotinib Reverses Multidrug Resistance (MDR) in Osteosarcoma by Inhibiting P-Glycoprotein (PGP1) Function In Vitro and In Vivo

Overexpression of the multidrug resistance (MDR)-related protein P-glycoprotein (PGP1), which actively extrudes chemotherapeutic agents from cells and significantly decreases the efficacy of chemotherapy, is viewed as a major obstacle in osteosarcoma chemotherapy. Anlotinib, a novel tyrosine kinase inhibitor (TKI), has good anti-tumor effects in a variety of solid tumors. However, there are few studies on the mechanism of anlotinib reversing chemotherapy resistance in osteosarcoma. In this study, cellular assays were performed in vitro and in vivo to evaluate the MDR reversal effects of anlotinib on multidrug-resistant osteosarcoma cell lines. Drug efflux and intracellular drug accumulation were measured by flow cytometry. The vanadate-sensitive ATPase activity of PGP1 was measured in the presence of a range of anlotinib concentrations. The protein expression level of ABCB1 was detected by Western blotting and immunofluorescence analysis. Our results showed that anlotinib significantly increased the sensitivity of KHOSR2 and U2OSR2 cells (which overexpress PGP1) to chemotherapeutic agents in vitro and in a KHOSR2 xenograft nude mouse model in vivo. Mechanistically, anlotinib increases the intracellular accumulation of PGP1 substrates by inhibiting the efflux function of PGP1 in multidrug-resistant cell lines. Furthermore, anlotinib stimulated the ATPase activity of PGP1 but affected neither the protein expression level nor the localization of PGP1. In animal studies, anlotinib in combination with doxorubicin (DOX) significantly decreased the tumor growth rate and the tumor size in the KHOSR2 xenograft nude mouse model. Overall, our findings suggest that anlotinib may be useful for circumventing MDR to other conventional antineoplastic drugs.

Average SAR prediction, validation, and evaluation for a compact MR scanner head-sized RF coil

A recently developed compact 3 T (C3T) MRI scanner with high performance gradients [1, 2] has a dedicated radiofrequency (RF) transmit coil that exposes only the head, neck and a small portion of the upper body region during head-first scanning. Due to the unique coil geometry and patient positioning, the established SAR model used for a conventional whole-body scanner cannot be directly translated to the C3T. Here a specific absorption rate (SAR) estimation and validation framework was developed and used to implement a dedicated and accurate SAR prediction model for the C3T. Two different SAR prediction models for the C3T were defined and evaluated: one based on an anatomically derived exposed mass, and one using a fixed anatomical position located caudally to the RF coil to determine the exposed mass. After coil modeling and virtual human body simulation, the designed SAR prediction model was implemented on the C3T and verified with calorimetry and in vivo scan power monitoring. The fixed-demarcation exposed mass model was selected as appropriate exposed mass region to accurately estimate the SAR deposition in the patient on the C3T.

Multicentre Study Using Machine Learning Methods in Clinical Diagnosis of Knee Osteoarthritis

Knee osteoarthritis (OA) is one of the most common musculoskeletal disorders. OA diagnosis is currently conducted by assessing symptoms and evaluating plain radiographs, but this process suffers from the subjectivity of doctors. In this study, we retrospectively compared five commonly used machine learning methods, especially the CNN network, to predict the real-world X-ray imaging data of knee joints from two different hospitals using Kellgren-Lawrence (K-L) grade of knee OA to help doctors choose proper auxiliary tools. Furthermore, we present attention maps of CNN to highlight the radiological features affecting the network decision. Such information makes the decision process transparent for practitioners, which builds better trust towards such automatic methods and, moreover, reduces the workload of clinicians, especially for remote areas without enough medical staff.

Management of Apatinib-Related Adverse Events in Patients With Advanced Osteosarcoma From Four Prospective Trials: Chinese Sarcoma Study Group Experience

Four prospective trials have reported apatinib-related efficacy in osteosarcoma, with a high response rate of 43.2%. Currently, Adverse Events (AEs) have increasingly gained attention, as treatment with multiple tyrosine kinase inhibitors (TKIs) is potentially lifelong. For this reason, a consensus meeting of the Chinese Sarcoma Study Group (CSSG), which is a multidisciplinary panel composed of pediatric, medical and surgical oncologists specializing in sarcoma, nurse specialists, oncological senior pharmacists and gastroenterologists, was held to develop comprehensive guidelines on AEs emerging due to apatinib treatment to better assist in the prevention, management, and understanding of AE development. We summarized all AEs that arose in ≥10% of the participants as well as rare AEs that required extra caution to prevent that were observed in these four published prospective trials and arranged these AEs into 14 disorder systems according to CTCAE 5.0. In this review, we discuss strategies for the management of AEs in patients with advanced osteosarcoma, with the aim of maximizing treatment benefits and minimizing the need for apatinib treatment discontinuation. We also focus on providing recommendations for the prophylaxis and treatment of advanced osteosarcoma using apatinib to achieve optimal outcomes.

Surgical Treatment of Sacral Metastatic Tumors

Objective

This study intends to retrospectively analyze the data of patients with sacral metastases in our center, and analyze the treatment methods and therapeutic effects of sacral metastases.

Methods

73 patients with sacral metastases treated in our hospital from June 2013 to June 2019 were retrospectively analyzed. There were 54 cases of neurological symptoms, 42 cases of sacroiliac joint instability, 24 cases of lower limb muscle weakness and 19 cases of abnormal urination and defecation. Four patients with tumors below S3 underwent complete tumor resection, 23 patients with tumors above S3 and without sacroiliac joint instability underwent tumor curettage and nerve root lysis, 34 patients with tumors above S3 and sacroiliac joint instability underwent tumor curettage, nerve root release and screw rod reconstruction. 12 patients with multiple metastases underwent percutaneous radiofrequency ablation and sacroplasty. VAS was used to evaluate the preoperative and postoperative pain scores, and the postoperative pain relief, neurological function, bowel function, wound healing and complications were evaluated.

Results

There were no perioperative death, 8 cases of poor wound healing, 5 cases of nerve injury, postoperative sensory and motor loss of lower limbs. Cerebrospinal fluid (CSF) leak in 7 cases. The patients were followed up for 6-25 months (mean 12 months). The VAS scores of patients with pain symptoms were 7 points before operation and 1.44 points after operation, In 19 patients with abnormal urination and defecation function, 12 patients recovered to normal 3-6 months after operation, 5 cases had no significant change compared with preoperative, and 2 cases had aggravated symptoms; 17 cases of patients with lower limb muscle strength were significantly recovered after operation, and the average muscle strength was increased by 2 grades; 30 cases of patients with unstable sacroiliac joint got internal fixation had significantly pain relief. Pain symptoms of 9 patients were significantly relieved after percutaneous radiofrequency ablation.

Conclusion

the operation of sacral metastases mainly adopts a relatively conservative surgical method, which can effectively improve the quality of life of patients with sacral metastases by retaining the nerve function and relieving the pain of patients, combining with radiofrequency ablation, sacroplasty and targeted drugs.

Bromodomain Inhibition Attenuates the Progression and Sensitizes the Chemosensitivity of Osteosarcoma by Repressing GP130/STAT3 Signaling

Osteosarcoma is the most common primary malignant bone tumor, and there are few ideal clinically available drugs. The bromodomain and extraterminal domain (BET) protein is an emerging target for aggressive cancer, but therapies targeting the BET in osteosarcoma have been unsuccessful in clinical trials to date, and further exploration of specific BET inhibitors is of great significance. In our study, we demonstrated that NHWD-870, a potent BET inhibitor in a phase I clinical trial, significantly inhibited tumor proliferation and promoted cell apoptosis by reversing the oncogenic signature in osteosarcoma. More importantly, we identified NHWD-870 impeded binding of BRD4 to the promoter of GP130 leading to diminished activation of JAK/STAT3 signaling pathway. Furthermore, GP130 knockdown significantly sensitizes the chemosensitivity in vitro. In OS cell-derived xenografts, NHWD-870 effectively inhibited the growth of osteosarcoma. Beyond that, NHWD-870 effectively inhibited the differentiation and maturation of precursor osteoclasts in vitro and attenuated osteoclast-mediated bone loss in vivo. Finally, we confirmed the efficacy of synthetic lethal effects of NHWD-870 and cisplatin in antagonizing osteosarcoma in a preclinical PDX model. Taken together, these findings demonstrate that NHWD-870, as an effective BET inhibitor, may be a potential candidate for osteosarcoma intervention linked to its STAT3 signaling inhibitory activity. In addition, NHWD-870 appears to be a promising therapeutic strategy for bone-associated tumors, as it interferes with the vicious cycle of tumor progression and bone destruction.

MYLK4 promotes tumor progression through the activation of epidermal growth factor receptor signaling in osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most common primary bone cancer in adolescents and lung metastasis is the leading cause of death in patients with OS. However, the molecular mechanisms that promote OS growth and metastasis remain unknown.

METHODS

We investigated the expression of myosin light chain kinase family members between metastasis and non-metastasis patients in the TARGET database and ensured that only myosin light chain kinase family member 4 (MYLK4) had higher expression in metastatic osteosarcoma patients. Then we confirmed the results by immunohistochemistry (IHC) and Western blotting (WB) of OS tissues. The effect of MYLK4 on the metastasis and proliferation of OS cells was investigated by wound healing, Transwell and colony-formation assays. Mass spectrum analysis was used to ensure the new binding protein of MYLK4. Tissue microarrays analysis was used to show the correlation between MYLK4 and pEGFR (Y1068). A series of in vivo experiments were conducted to reveal the mechanisms by which MYLK4 modulated the metastasis and proliferation of OS.

RESULTS

Myosin Light Chain Kinase Family Member 4 (MYLK4) was significantly upregulated in metastatic human OS tissues. Growth and metastasis of OS could be accelerated by MYLK4 overexpression, whereas silencing MYLK4 expression resulted in decreased cell growth and metastasis. Mechanistically, mass spectrum analysis showed that MYLK4 interacted with the epidermal growth factor receptor (EGFR) in osteosarcoma cells and promoted growth and metastasis via the EGFR signaling pathway. Tissue microarrays analysis also showed that MYLK4 expression had a positive correlation with the expression of pEGFR (Y1068). Moreover, the EGFR inhibitor gefitinib could partially reverse the effect of cell proliferation and metastasis caused by MYLK4 overexpression. Importantly, the combination of MYLK4 and EGFR inhibitors had synergistic effects on growth and metastasis of OS in vitro and in vivo.

CONCLUSION

Our results indicate that MYLK4 promotes OS growth and metastasis by activating the EGFR signaling pathway and can be a novel therapeutic target for the treatment of OS patients.

Five lncRNAs associated with the survival of hepatocellular carcinoma: a comprehensive study based on WGCNA and competing endogenous RNA network

OBJECTIVE

The competing endogenous RNA (ceRNA) presents a comprehensive regulatory network among lncRNAs, miRNAs and mRNA. The ceRNA provides significant information in understanding the pathology of cancer. This study aimed to explore a lncRNA-associated ceRNA network for predicting the overall survival of patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In this study, RNA-sequencing data of HCC were downloaded from The Cancer Genomes Atlas (TCGA) database. The module-trait relationship was analyzed with Weighted gene co-expression network analysis (WGCNA). The key module associated with tumor was identified, as well as the involved lncRNAs, mRNAs and miRNAs. The preliminary ceRNA network was constructed with Cytoscape. The survival analysis was further performed to screen survival-relevant lncRNAs, mRNAs and miRNAs, and then the survival-associated ceRNA network was reconstructed.

RESULTS

Eventually, 5 lncRNAs, 10 miRNAs, and 25 mRNAs were included in the reconstructed ceRNA network.

CONCLUSIONS

The identified lncRNAs were promising candidate biomarkers in HCC diagnosis and therapeutics. This analysis process was effective to construct ceRNA network. The result will be conductive to explore the significant lncRNAs and regulatory mechanism.

Hexokinase 2 discerns a novel circulating tumor cell population associated with poor prognosis in lung cancer patients

Unlike other epithelial cancer types, circulating tumor cells (CTCs) are less frequently detected in the peripheral blood of non-small cell lung cancer (NSCLC) patients using epithelial marker-based detection approaches despite the aggressive nature of NSCLC. Here, we demonstrate hexokinase-2 (HK2) as a metabolic function-associated marker for the detection of CTCs. In 59 NSCLC patients bearing cytokeratin-positive (CKpos) primary tumors, HK2 enables resolving cytokeratin-negative (HK2high/CKneg) CTCs as a prevalent population in about half of the peripheral blood samples with positive CTC counts. However, HK2high/CKneg tumor cells are a minority population in pleural effusions and cerebrospinal fluids. Single-cell analysis shows that HK2high/CKneg CTCs exhibit smaller sizes but consistent copy number variation profiles compared with CKpos counterparts. Single-cell transcriptome profiling reveals that CK expression levels of CTCs are independent of their epithelial-to-mesenchymal transition (EMT) status, challenging the long-standing association between CK expression and EMT. HK2high/CKneg CTCs display metastasis and EGFR inhibitor resistance-related molecular signatures and are selectively enriched in patients with EGFRL858R driver oncogene mutation as opposed to EGFR19Del , which is more frequently found in patients with prevalent CKpos CTCs in the blood. Consistently, treatment-naïve patients with a larger number or proportion of HK2high/CKneg CTCs in the blood exhibit poor therapy response and shorter progression-free survival. Collectively, our approach resolves a more complete spectrum of CTCs in NSCLC that can potentially be exploited to identify patient prognosis before therapy.

Retraction Note to: Natural product pectolinarigenin inhibits osteosarcoma growth and metastasis via SHP-1-mediated STAT3 signaling inhibition

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1038/s41419-021-03529-7

Development of a PET/EPRI combined imaging system for assessing tumor hypoxia

Precise quantitative delineation of tumor hypoxia is essential in radiation therapy treatment planning to improve the treatment efficacy by targeting hypoxic sub-volumes. We developed a combined imaging system of positron emission tomography (PET) and electron para-magnetic resonance imaging (EPRI) of molecular oxygen to investigate the accuracy of PET imaging in assessing tumor hypoxia. The PET/EPRI combined imaging system aims to use EPRI to precisely measure the oxygen partial pressure in tissues. This will evaluate the validity of PET hypoxic tumor imaging by (near) simultaneously acquired EPRI as ground truth. The combined imaging system was constructed by integrating a small animal PET scanner (inner ring diameter 62 mm and axial field of view 25.6 mm) and an EPRI subsystem (field strength 25 mT and resonant frequency 700 MHz). The compatibility between the PET and EPRI subsystems were tested with both phantom and animal imaging. Hypoxic imaging on a tumor mouse model using 18F-fluoromisonidazole radio-tracer was conducted with the developed PET/EPRI system. We report the development and initial imaging results obtained from the PET/EPRI combined imaging system.

H3.3 K36M Mutation as a Clinical Diagnosis Method of Suspected Chondroblastoma Cases

Objective

Whether H3.3 K36M mutation (H3K36M) could be an approach if the diagnosis of chondroblastoma (CB) patients was indistinct and it was suspected to be unclear clinically.

Methods

We reviewed and compared our clinical experiences of CB cases and some suspected cases, which were not diagnosed distinctly, between 2013 to 2019. A total of 15 male and four female cases included in this study were seperated into two groups, CB group and suspected case (SC) group. The CB group included 13 men and 3 women, with an age range from 9 to 54 (mean age, 22 years old). The SC group included two men and one woman, with the age range from 13 to 25 (mean age, 19 years old). In both groups the patients had been followed‐up until December 2019 and none of the patients had prior treatment history. We evaluated the clinical complaints, radiological features, and clinical‐histological features of the cases and performed an immunohistochemical (IHC) study to detect whether the H3K36M expression of cases was different, consistent with a gene‐mutation analysis.

Results

In both groups, the radiologic features of both groups appeared as round low‐density shadow with a clear edge, pathologic features showed diffuse proliferation of neoplastic cells with multinuclear giant cells. The radiological tumor size of CB group and SC group showed little difference, which was about 29.0*21.6 mm. Clinical‐immunohistochemical features of both groups showed chondroid matrix inside with naïve tumor cells, multinucleated giant cells, and ground substance cells. Most of them showed chondro‐related antibody positive (12 cases) but some of them showed S‐100 negative (four cases). The clear difference of both groups was the result of H3K36M IHC study and gene analysis. In our cases, the CB group showed diffuse H3K36M positive and the SC group showed negative. The gene mutation analysis revealed that H3K36M‐positive CB patients had K36M mutation, which were not found in the SC group. Sanger sequencing showed an A > T substitution at codon 36 of histone H3F3B. No other types of histone H3 mutation was detected in the CB group. Particularly, one of the suspected cases showed a G34W mutation was confirmed to be a giant cell tumor of bone (GCTB).

Conclusions

Our study showed H3K36M immunohistochemistry and gene mutation analysis were specific clinical diagnostic tools to distinguish suspected CB from other giant cell‐rich or cartilage matrix‐diffuse bone tumors. The clinical‐radiological and histomorphological features of patients gave suggestions on whether the H3K36M IHC and gene analysis should be required.

Single-Cell Sequencing-Enabled Hexokinase 2 Assay for Noninvasive Bladder Cancer Diagnosis and Screening by Detecting Rare Malignant Cells in Urine

Bladder cancer (BC) is among the most common tumors with a high recurrence rate, necessitating noninvasive and sensitive diagnostic methods. Accurate detection of exfoliated tumor cells (ETCs) in urine is crucial for noninvasive BC diagnosis but suffers from limited sensitivity when ETCs are rare and confounded by reactive, regenerative, or reparative cells. Single-cell sequencing (SCS) enables accurate detection of ETCs by surveying oncogenic driver mutations or genome-wide copy number alternations. To overcome the low-throughput limitation of SCS, we report a SCS-validated cellular marker, hexokinase 2 (HK2), for high-throughput screening cells in urine and detecting ETCs engaging elevated glycolysis. In the SCS-based training set, a total of 385 cells from urine samples of eight urothelial carcinoma (UC) patients were sequenced to establish a HK2 threshold that achieved >90% specificity for ETC detection. This urine-based HK2 assay was tested with a blinded patient group (n = 384) including UC and benign genitourinary disorders as a validation cohort for prospectively evaluating diagnostic accuracy. The sensitivity, specificity, positive predictive value, and negative predictive value of the assay were 90, 88, 83, and 93%, respectively, which were superior to urinary cytology. For investigating the potential to be a screening test, the HK2 assay was tested with a group of healthy individuals (n = 846) and a 6-month follow-up. The specificity was 98.4% in this health group. Three participants were found to have >5 putative ETCs that were sequenced to exhibit recurrent copy number alternations characteristic of malignant cells, demonstrating early BC detection before current clinical methods.

MicroRNA-1286 inhibits osteogenic differentiation of mesenchymal stem cells to promote the progression of osteoporosis via regulating FZD4 expression

OBJECTIVE

The aim of this study was to investigate whether microRNA-1286 could inhibit the osteogenic differentiation of human marrow mesenchymal stem cells (hMSCs) by regulating FZD4 expression and promoting the progression of osteoporosis.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of microRNA-1286 in the serum of patients with osteoporosis. Meanwhile, microRNA-1286 expression in different stages of osteogenic differentiation of hMSCs was measured by qRT-PCR as well. After overexpression of microRNA-1286 and FZD4 in hMSCs, the mRNA expression levels of microRNA-1286, alkaline phosphatase (ALP), RUNX2 and osteocalcin (OCN) were detected by qRT-PCR. The protein expression levels of RUNX2 and OCN were detected by Western blot. Meanwhile, alkaline phosphatase (ALP) activity and expression in cells were examined using ALP assay kit and ALP staining method, respectively. Cell mineralized nodules were detected through the alizarin red staining test. Bioinformatics method was used to predict the binding site of microRNA-1286 to FZD4. Subsequent luciferase reporter gene assay was performed to verify whether microRNA-1286 could combine with FZD4. After overexpression or knockdown of microRNA-1286, the mRNA and protein expressions of FZD4 were analyzed using qRT-PCR and Western blot assay, respectively. After the simultaneous overexpression of microRNA-1286 and FZD4 in hMSCs, the mRNA expression levels of ALP, RUNX2 and OCN, ALP activity and content, and cell mineralization ability were successively examined.

RESULTS

The expression of microRNA-1286 in the serum of patients with osteoporosis was significantly higher than that of the normal population. Meanwhile, microRNA-1286 expression decreased with the increase of osteogenic differentiation days of hAMSCs. After the overexpression of microRNA-1286, ALP, RUNX2, and OCN levels, ALP activity, RUNX2, and OCN protein levels, as well as mineralized nodule formation were significantly reduced. However, results were reversed when FZD4 was simultaneously up-regulated. Luciferase reporter gene assay results verified that microRNA-1286 could bind to FZD4. After the overexpression of microRNA-1286, the mRNA and protein expressions of FZD4 were found significantly down-regulated. However, results were reversed after knocking down microRNA-1286. Furthermore, the simultaneous overexpression of microRNA-1286 and FZD4 could counteract the inhibitory effect of over-expression of microRNA-1286 on osteogenic differentiation of hMSCs.

CONCLUSIONS

MicroRNA-1286 can regulate FZD4 expression and inhibit osteogenic differentiation of hMSCs, thereby promoting the development of osteoporosis.

Her4 promotes cancer metabolic reprogramming via the c-Myc-dependent signaling axis

Despite the growing recognition of metabolic reprogramming as an important hallmark of cancer in the past few years, the molecular mechanisms underlying metabolic alterations during tumorigenesis remain unclear. In this study, we identified a critical role of Her4 in rewiring cancer metabolism toward tumor-promoting metabolic processes, including increased glycolysis, glutaminolysis, mitochondrial biogenesis, and oxidative phosphorylation, which may in part cooperate to promote tumorigenesis. We found that overexpression of Her4 promoted the stabilization of c-Myc through a CIP2A-mediated increase in c-Myc^S62 phosphorylation and GSK3β-mediated decrease in c-Myc^T58 phosphorylation, both of which decreased c-Myc degradation. Furthermore, Her4 was found to increase glucose uptake and tumor growth in an osteosarcoma xenograft model. Overall, these findings provide a better understanding of the involvement of Her4 in tumorigenesis and document its potential role in metabolic reprogramming for the first time. We believe that our study might lead to promising opportunities for targeted metabolic therapy for cancer.

A psychological health support scheme for medical teams in COVID-19 outbreak and its effectiveness

Background

Medical staff fighting the COVID-19 pandemic are experiencing stress from high occupational risk, panic in the community and the extreme workload. Maintaining the psychological health of a medical team is essential for efficient functioning, but psychological intervention models for emergency medical teams are rare.

Aims

To design a systematic, full-coverage psychological health support scheme for medical teams serving large-scale emergent situations, and demonstrate its effectiveness in a real-world study in Leishenshan Hospital during the COVID-19 epidemic in Wuhan, China.

Methods

The scheme integrates onsite and online mental health resources and features team-based psychosocial support and evidence-based interventions. It contained five modules, including a daily measurement of mood, a daily mood broadcast that promotes positive affirmation, a daily online peer-group activity with themes based on the challenges reported by the team, Balint groups and an after-work support team. The daily mood measurement provides information to the other modules. The scheme also respects the special psychological characteristics of medical staff by promoting their strengths.

Results

The scheme economically supported a special medical team of 156 members with only one onsite psychiatrist. Our data reflected that the entire medical team maintained an overall positive outlook (7–9 out of 10 in a Daily Mood Index, DMI) for nearly 6 weeks of continuous working. Since the scheme promoted self-strengths and positive self-affirmation, the number of self-reports of life-related gains were high and played a significant effect on the DMI. Our follow-up investigations also revealed that multiple modules of the scheme received high attention and evaluation levels.

Conclusion

Our quantitative data from Leishenshan hospital, Wuhan, China, show that the programme is adequate to support the continuous high workload of medical teams. This scheme could be applied to medical teams dealing with emergent situations.

Automated Classification of Osteosarcoma and Benign Tumors using RNA-seq and Plain X-ray

Osteosarcoma is a prominent bone cancer that typically affects adolescents or people in late adulthood. Early recognition of this disease relies on imaging technologies such as x-ray radiography to detect tumor size and location. This paper aims to differentiate osteosarcoma from benign tumors by analyzing both imaging and RNA-seq data through a combination of image processing and machine learning. In experimental results, the proposed method achieved an Area Under the Receiver Operator Characteristic Curve (AUC) of 0.7272 in three-fold cross-validation, and an AUC of 0.9015 using leave-one-out cross-validation.

Development of a psychological first-aid model in inpatients with COVID-19 in Wuhan, China

Background

Facing the social panic and substantial shortage of medical resources during the coronavirus disease 2019 (COVID-19) outbreak, providing psychological first-aid to inpatients is essential for their rehabilitation and the orderly operating of medical systems. However, the closed-ward environment and extreme shortage of onsite mental health workers have limited the use of traditional face-to-face diagnosis and psychological interventions.

Aim

To develop a mental health intervention model for inpatients that can be applied during a widespread epidemic, such as COVID-19.

Methods

In a medical team stationed in Leishenshan Hospital, Wuhan, China, we integrated onsite and online psychological support resources to implement a graded psychological intervention system. The onsite psychiatrist established trust with the patients and classified them into categories according to their symptom severity. While face-to-face evaluation and intervention are critical for effective online support, the online team effectively extended the scope of the ‘first-aid’ to all patients.

Conclusion

This integrated onsite and online approach was effective and efficient in providing psychological interventions for inpatients during the crisis. Our model provides a realistic scheme for healthcare systems in or after the COVID-19 epidemic and also could be adopted in areas of the world with insufficient mental healthcare resources.

Design, evaluation and initial imaging results of a PET insert based on strip-line readout for simultaneous PET/MRI

We present the development of a PET insert system for potential simultaneous PET/MR imaging using a 9.4 T small animal MRI scanner to test our system. The detectors of the system adopt a strip-line based multiplexing readout method for SiPM signals. In this readout, multiple SiPM outputs in a row share a common strip-line. The position information about a hit SiPM is encoded in the propagation time difference of the signals arriving at the two ends of the strip-line. The use of strip-lines allows us to place the data acquisition electronics remotely from the detector module to greatly simplify the design of the detector module and minimize the mutual electromagnetic interference. The prototype is comprised of 14 detector modules, each of which consists of an 8x4 LYSO scintillator array (each LYSO crystal is 3x3x10 mm³) coupled to two units of Hamamatsu MPPC arrays (4x4, 3.2 mm pitch) that are mounted on a strip-line board. On the strip-line board, outputs of the 32 SiPMs are routed to 2 strip-lines so that 16 SiPM signals share a strip-line. The detector modules are installed inside a plastic cylindrical supporting structure with an inner and outer diameter of 60 mm and 115 mm, respectively, to fit inside a Bruker BioSpec 9.4 Tesla MR scanner. The axial field of view of the prototype is 25.4 mm. The strip-lines were extended by using 5-meter cables to a sampling data acquisition (DAQ) board placed outside the magnet. The detectors were not shielded in the interest of investigating how they may affect and be affected by the MRI. Experimental tests were conducted to evaluate detection performance, and phantom and animal imaging were carried out to assess the spatial resolution and the MR compatibility of the PET insert. Initial results are encouraging and demonstrate that the prototype insert PET can potentially be used for PET/MR imaging if appropriate shielding will be implemented for minimizing the mutual interference between the PET and MRI systems.

Diversity and abundance of comammox bacteria in the sediments of an urban lake

AIMS

Although comammox have been discovered in a variety of ecosystems, there are few studies in urban lakes. This paper attempted to confirm whether this ammonia-oxidizing microbe exists in urban lakes and to determine the factors influencing its existence.

METHODS AND RESULTS

This study investigated the diversity and abundance of comammox bacteria in sediments of a typical urban lake in China, and their ecological relationship with other ammonia-oxidizing micro-organisms. The phylogenetic analysis indicated that comammox clade A existed in the sediment of Lake Donghu, and the comammox bacteria co-existed with ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing (anammox) bacteria in the sediment of this lake. The abundances of the ammonia monooxygenase subunit A (amoA) genes for comammox, AOA, AOB and anammox 16S rRNA were 2·43 × 10⁸ , 1·07 × 10⁸ , 3·24 × 10⁷ and 3·21 × 10¹¹ copies per gram dry sediment respectively. Moreover, the amoA gene abundance of comammox was positively correlated with that of AOA and AOB. The redundancy analysis showed that the abundance of the comammox amoA gene was negatively correlated with the concentration of main indicators for nitrogen status in both the sediment and the water column, indicating that eutrophication may inhibit the growth of comammox bacteria.

CONCLUSIONS

Comammox bacteria play an important ecological role in the nitrogen cycle of urban lake sediments.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results indicated comammox bacteria were widespread in urban lakes and eutrophication may inhibit their growth.

Surgical resection and reconstructive techniques using autologous femoral head bone-grafting in treating partial acetabular defects arising from primary pelvic malignant tumors

Background

The aim of this study is to present and evaluate surgical resection and reconstructive techniques using autologous femoral head bone-grafting in treating partial acetabular defects arising from primary pelvic malignant tumors.

Methods

From January 2009 until January 2015, a total of 20 primary pelvic malignancy cases involving the acetabulum were retrospectively investigated. Surgical resections and reconstructions were conducted based on the type of the tumor with custom osteotomy guides and autologous femoral head bone-grafting. In all cases, prosthesis survival period, complication occurrence, and clinical outcomes data were collected and analyzed.

Results

Thirteen male and 7 female patients with an average age of 48 years old (range 23-69 years old) were followed for a median of 69 months (range 48-112 months). Of these cases, 17 included chondrosarcomas and 3 additional patients with a malignant giant cell tumor of bone (MBGCT) as proven by pathology. During follow-up, 3 cases of chondrosarcoma recurred (15%), of which two cases received hemi-pelvic amputation, 1 case of MBGCT relapsed and developed pulmonary metastases. Two cases of acetabular prosthesis with an impending dislocation received closed reduction followed by 6 weeks of hip abduction brace fixation. One case of prosthesis loosening was revised. In another case a deep infection occurred with debridement and prosthesis removal. Musculoskeletal Tumor Society 1993 (MSTS-93) score was utilized to conduct functional evaluation: 13 cases were good, 6 were average and one was poor.

Conclusion

The precision of the osteotomies performed is likely crucial for this type of reconstructive strategy to be successful. The use of custom guides for acetabular osteotomies and femoral head reconstruction can improve functional outcomes with relatively low complications at the intermediate length of follow-up.