The role of lipid metabolism in osteoporosis: Clinical implication and cellular mechanism

In recent years, researchers have become focused on the relationship between lipids and bone metabolism balance. Moreover, many diseases related to lipid metabolism disorders, such as nonalcoholic fatty liver disease, atherosclerosis, obesity, and menopause, are associated with osteoporotic phenotypes. It has been clinically observed in humans that these lipid metabolism disorders promote changes in osteoporosis-related indicators bone mineral density and bone mass. Furthermore, similar osteoporotic phenotype changes were observed in high-fat and high-cholesterol-induced animal models. Abnormal lipid metabolism (such as increased oxidized lipids and elevated plasma cholesterol) affects bone microenvironment homeostasis via cross-organ communication, promoting differentiation of mesenchymal stem cells to adipocytes, and inhibiting commitment towards osteoblasts. Moreover, disturbances in lipid metabolism affect the bone metabolism balance by promoting the secretion of cytokines such as receptor activator of nuclear factor-kappa B ligand by osteoblasts and stimulating the differentiation of osteoclasts. Conclusively, this review addresses the possible link between lipid metabolism disorders and osteoporosis and elucidates the potential modulatory mechanisms and signaling pathways by which lipid metabolism affects bone metabolism balance. We also summarize the possible approaches and prospects of intervening lipid metabolism for osteoporosis treatment.

Avoiding unnecessary biopsy: the combination of PRIMARY score with prostate-specific antigen density for prostate biopsy decision

BACKGROUND

Avoiding unnecessary biopsies for men with suspected prostate cancer remains a clinical priority. The recently proposed PRIMARY score improves diagnostic accuracy in detecting clinically significant prostate cancer (csPCa). The aim of this study was to determine the best strategy combining PRIMARY score or MRI reporting scores (Prostate Imaging Reporting and Data System [PI-RADS]) with prostate-specific antigen density (PSAD) for prostate biopsy decision making.

METHODS

A retrospective analysis of 343 patients who underwent both 68Ga-PSMA PET/CT and MRI before prostate biopsy was performed. PSA was restricted to <20 ng/ml. Different biopsy strategies were developed and compared based on PRIMARY score or PI-RADS with PSAD thresholds. Decision curve analysis (DCA) was plotted to define the optimal biopsy strategy.

RESULTS

The prevalence of csPCa was 41.1% (141/343). According to DCA, the strategies of PRIMARY score +PSAD (strategy #1, strategy #2, strategy #6) had a higher net benefit than the strategies of PI-RADS + PSAD at the risk threshold of 8-20%. The best diagnostic strategy was strategy #1 (PRIMARY score 4-5 or PSAD ≥ 0.20), which avoided 38.2% biopsy procedures while missed 9.2% of csPCa cases. From a clinical perspective, strategies with a lower risk of missing csPCa were strategy #2 (PRIMARY score ≥4 or PSAD ≥ 0.15), which avoided 28.6% biopsies while missed 5.7% of csPCa cases, or strategy #6 (PRIMARY score≥3 or PSAD ≥ 0.15), which avoided 20.7% biopsies while missed only 3.5% of csPCa cases. The limitations of the study were the retrospective single-center nature.

CONCLUSIONS

The combination of PRIMARY score +PSAD allows individualized decisions to avoid unnecessary biopsy, outperforming the strategies of PI-RADS + PSAD. Further prospective trials are needed to validate these findings.

Surgical evidence-based comparison of [68Ga]Ga-FAPI-04 PET and MRI-DWI for assisting debulking surgery in ovarian cancer patients

PURPOSE

Imaging assessment of abdominopelvic tumor burden is crucial for debulking surgery decision in ovarian cancer patients. This study aims to compare the efficiency of [68Ga]Ga-FAPI-04 FAPI PET and MRI-DWI in the preoperative evaluation and its potential impact to debulking surgery decision.

METHODS

Thirty-six patients with suspected/confirmed ovarian cancer were enrolled and underwent integrated [68Ga]Ga-FAPI-04 PET/MRI. Nineteen patients (15 stage III-IV and 4 I-II stage) who underwent debulking surgery were involved in the diagnostic efficiency analysis. The images of [68Ga]Ga-FAPI-04 PET and MRI-DWI were visually analyzed respectively. Immunohistochemistry on FAP was performed in metastatic lesions to investigate the radiological missing of [68Ga]Ga-FAPI-04 PET as well as its different performance in primary debulking surgery (PDS) and interval debulking surgery (IDS) patients. Potential imaging impact on management was also studied in 35 confirmed ovarian cancer patients.

RESULTS

[68Ga]Ga-FAPI-04 PET displayed higher sensitivity (76.8% vs.59.9%), higher accuracy (84.9% vs. 80.7%), and lower missing rate (23.2% vs. 40.1%) than MRI-DWI in detecting abdominopelvic metastasis. The diagnostic superiority of [68Ga]Ga-FAPI-04 PET is more obvious in PDS patients but diminished in IDS patients. [68Ga]Ga-FAPI-04 PET outperformed MRI-DWI in 70.8% abdominopelvic regions (17/24), which contained seven key regions that impact the resectability and surgical complexity. MRI-DWI hold advantage in the peritoneal surface of the bladder and the central tendon of the diaphragm. Of the contradictory judgments between the two modalities (14.9%), [68Ga]Ga-FAPI-04 PET correctly identified more lesions, particularly in PDS patients (73.8%). In addition, FAP expression was independent of lesion size and decreased in IDS patients. [68Ga]Ga-FAPI-04 PET changed 42% of surgical planning that was previously based on MRI-DWI.

CONCLUSION

[68Ga]Ga-FAPI-04 PET is more efficient in assisting debulking surgery in ovarian cancer patients than MRI-DWI. Integrated [68Ga]Ga-FAPI-04 PET/MR imaging is a potential method for planning debulking surgery in ovarian cancer patients.

Calcium-based polymers for suppression of soil acidification by improving acid-buffering capacity and inhibiting nitrification

Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions. Biodegradable and environmentally friendly materials, such as calcium lignosulfonate (CaLS), calcium poly(aspartic acid) (PASP-Ca), and calcium poly γ-glutamic acid (γ-PGA-Ca), are known to effectively ameliorate soil acidity. However, their effectiveness in inhibiting soil acidification has not been studied. This study aimed to evaluate the effect of CaLS, PASP-Ca, and γ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly (i.e., via nitrification) caused by the application of HNO3 and urea, respectively. For comparison, Ca(OH)2 and lignin were used as the inorganic and organic controls, respectively. Among the materials, γ-PGA-Ca drove the substantial improvements in the pH buffering capacity (pHBC) of the soil and exhibited the greatest potential in inhibiting HNO3-induced soil acidification via protonation of carboxyl, complexing with Al3+, and cation exchange processes. Under acidification induced by urea, CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation. Furthermore, the sharp reduction in the population sizes of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) confirmed the inhibition of nitrification via CaLS application. Therefore, compared to improving soil pHBC, CaLS may play a more important role in suppressing indirect acidification. Overall, γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO3 addition, whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification. In conclusion, these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.

First-in-human validation of enzymolysis clearance strategy for decreasing renal radioactivity using modified [68Ga]Ga-HER2 Affibody

PURPOSE

Enzymolysis clearance strategy, characterized by releasing the non-reabsorbable radioactive fragment under the specific cleavage of enzymes, is confirmed to be a safe and effective way to reduce the renal radioactivity accumulation in mice. However, the effectiveness of this strategy in humans remains unknown. Human epidermal growth factor receptor 2 (HER2) is overexpressed in various types of tumors, and radiolabeled HER2 Affibody is believed to be an attractive tool for HER2-targeted theranostics. However, its wide application is limited by the high and persistent renal uptake. In this study, we intend to validate the effectiveness of enzymolysis clearance strategy in reducing renal accumulation by using a modified HER2 Affibody.

MATERIALS AND METHODS

A new HER2 Affibody ligand, NOTA-MVK-ZHER2:2891, containing a cleavable Met-Val-Lys (MVK) linker was synthesized and labeled with 68Ga. The microPET imaging study was performed in SKOV-3 tumor mice to assess the uptakes of the control ligand and the MVK one in tumors and kidneys. Seven healthy volunteers were included for biodistribution and dosimetric studies with both the control and MVK ligands performed 1 week apart. Urine and blood samples from healthy volunteers were collected for in vivo metabolism study of the two ligands. Four HER2-positive and two HER2-negative patients were recruited for [68Ga]Ga-NOTA-MVK-ZHER2:2891 PET/CT imaging at 2 and 4 h post-injection (p.i.).

RESULTS

[68Ga]Ga-NOTA-MVK-ZHER2:2891 was stable both in PBS and in mouse serum. MicroPET images showed that the tumor uptake of [68Ga]Ga-NOTA-MVK-ZHER2:2891 was comparable to that of [68Ga]Ga-NOTA-ZHER2:2891 at all the time points, while the kidney uptake was significantly reduced 40 min p.i. (P < 0.05). The biodistribution study in healthy volunteers showed that the kidney uptake of MVK ligand was significantly lower than that of the control ligand at 1 h p.i. (P < 0.05), with the SUVmean of 34.3 and 45.8, respectively, while the uptakes of the two ligands in the other organs showed negligible difference. The effective doses of the MVK ligand and the control one were 26.1 and 28.7 µSv/MBq, respectively. The enzymolysis fragment of [68Ga]Ga-NOTA-Met-OH was observed in the urine samples of healthy volunteers injected with the MVK ligand, indicating that the enzymolysis clearance strategy worked in humans. The PET/CT study of patients showed that the range of SUVmax of HER2-positive lesions was 9.4-21, while that of HER2-negative lesions was 2.7-6.2, which suggested that the MVK modification did not affect the ability of ZHER2:2891 structure to bind with HER2.

CONCLUSION

We for the first time demonstrated that enzymolysis clearance strategy can effectively reduce renal radioactivity accumulation in humans. This strategy is expected to decrease renal radiation dose of peptide and small protein-based radiotracers, especially in the field of radionuclide therapy.

Interplay between lipid dysregulation and ferroptosis in chondrocytes and the targeted therapy effect of metformin on osteoarthritis

INTRODUCTION

Osteoarthritis (OA) is a devastating whole-joint disease affecting a large population worldwide; the role of lipid dysregulation in OA and mechanisms underlying targeted therapy effect of lipid-lowering metformin on OA remains poorly defined.

OBJECTIVES

To investigate the effects of lipid dysregulation on OA progression and to explore lipid dysregulation-targeting OA treatment of metformin.

METHODS

RNA-Seq data, biochemical, and histochemical assays in human and murine OA cartilage as well as primary chondrocytes were utilized to determine lipid dysregulation. Effects of metformin, a potent lipid-lowering medication, on ACSL4 expression and chondrocyte metabolism were determined. Further molecular experiments, including RT-qPCR, western blotting, flow cytometry, and immunofluorescence staining, were performed to investigate underlying mechanisms. Mice with intra-articular injection of metformin were utilized to determine the effects on ACLT-induced OA progression.

RESULTS

ACSL4 and 4-HNE expressions were elevated in human and ACLT-induced mouse OA cartilage and IL-1β-treated chondrocytes (P < 0.05). Ferrostatin-1 largely rescued IL-1β-induced MDA, lipid peroxidation, and ferroptotic mitochondrial morphology (P < 0.05). Metformin decreased the levels of OA-related genes (P < 0.05) and increased the levels of p-AMPK and p-ACC in IL-1β-treated chondrocytes. Intra-articular injection of metformin alleviated ACLT-induced OA lesions in mice, and reverted the percentage of chondrocytes positive for MMP13, Col2a1, ACSL4 and 4-HNE in ACLT mice (P < 0.05). Ferroptotic chondrocytes promoted the recruitment and chemotaxis of RAW264.7 cells via CCL2, which was blocked by metformin in vitro (P < 0.05).

CONCLUSION

We establish a critical role of polyunsaturated fatty acids metabolic process in OA cartilage degradation and define metformin as a potential OA treatment. Metformin reshapes lipid availability and ameliorates chondrocyte ferroptosis sensitivity via the AMPK/ACC pathway. In the future, gene-edited animals and extensive omics technologies will be utilized to reveal detailed lipids' involvement in cartilage lesions.

Spatiotemporal Concurrent PARP Inhibitor Sensitization Based on Radiation-Responsive Nanovesicles for Lung Cancer Chemoradiotherapy

The implementation of chemoradiation combinations has gained great momentum in clinical practices. However, the full utility of this paradigm is often restricted by the discordant tempos of action of chemotherapy and radiotherapy. Here, a gold nanoparticle-based radiation-responsive nanovesicle system loaded with cisplatin and veliparib, denoted as CV-Au NVs, is developed to augment the concurrent chemoradiation effect in a spatiotemporally controllable manner of drug release. Upon irradiation, the in situ generation of •OH induces the oxidation of polyphenylene sulfide from being hydrophobic to hydrophilic, resulting in the disintegration of the nanovesicles and the rapid release of the entrapped cisplatin and veliparib (the poly ADP-ribose polymerase (PARP) inhibitor). Cisplatin-induced DNA damage and the impairment of the DNA repair mechanism mediated by veliparib synergistically elicit potent pro-apoptotic effects. In vivo studies suggest that one-dose injection of the CV-Au NVs and one-time X-ray irradiation paradigm effectively inhibit tumor growth in the A549 lung cancer model. This study provides new insight into designing nanomedicine platforms in chemoradiation therapy from a vantage point of synergizing both chemotherapy and radiation therapy in a spatiotemporally concurrent manner.

Decomposed FDG PET-based phenotypic heterogeneity predicting clinical prognosis and decision-making in temporal lobe epilepsy patients

OBJECTIVE

This study utilized a data-driven Bayesian model to automatically identify distinct latent disease factors represented by overlapping glucose metabolism patterns from 18F-Fluorodeoxyglucose PET (18F-FDG PET) to analyze heterogeneity among patients with TLE.

METHODS

We employed unsupervised machine learning to estimate latent disease factors from 18F-FDG PET scans, representing whole-brain glucose metabolism patterns in seventy patients with TLE. We estimated the extent to which multiple distinct factors were expressed within each participant and analyzed their relevance to epilepsy burden, including seizure onset, duration, and frequency. Additionally, we established a predictive model for clinical prognosis and decision-making.

RESULTS

We identified three latent disease factors: hypometabolism in the unilateral temporal lobe and hippocampus (factor 1), hypometabolism in bilateral prefrontal lobes (factor 2), and hypometabolism in bilateral temporal lobes (factor 3), variably co-expressed within each patient. Factor 3 demonstrated the strongest negative correlation with the age of onset and duration (r =  - 0.33, - 0.38 respectively, P < 0.05). The supervised classifier, trained on latent disease factors for predicting patient-specific antiepileptic drug (AED) responses, achieved an area under the curve (AUC) of 0.655. For post-surgical seizure outcomes, the AUC was 0.857, and for clinical decision-making, it was 0.965.

CONCLUSIONS

Decomposing 18F-FDG PET-based phenotypic heterogeneity facilitates individual-level predictions relevant to disease monitoring and personalized therapeutic strategies.

Comparison of diagnostic efficacy between 99mTc-methylene diphosphate SPECT/CT and MRI for bone and joint infections: a multicenter retrospective analysis

Objective

There is currently no non-invasive examination that can fully determine the diagnosis of osteomyelitis. SPECT/CT tomographic fusion imaging can provide both local metabolic activity and anatomical information to determine the condition and location. This study evaluates the diagnostic efficacy of 99mTc-MDP SPECT/CT in bone infections, compared to MRI.

Methods

In this multicenter retrospective study, 363 patients with suspected bone and joint infections or osteomyelitis were included. Participants underwent 99mTc-MDP SPECT/CT and/or MRI examinations, supplemented by pathogenic bacterial cultures and histopathological analysis.

Results

Only SPECT/CT was tested in 169 patients, and only MRI was used in 116. 78 people have implemented both inspections and have detailed information. The diagnostic sensitivity and specificity of SPECT/CT for infection were 96% and 92% respectively, with an accuracy of 96%. For MRI, these figures were 88%, 84%, and 87% respectively.

Conclusion

This represents the largest global study to date evaluating osteomyelitis and bone infection diagnosis using 99mTc-MDP SPECT/CT tomographic fusion imaging. The findings indicate that 99mTc-MDP SPECT/CT fusion imaging offers superior diagnostic accuracy compared to MRI. This is particularly evident in cases involving metallic implants and chronic infections. 99mTc-MDP SPECT/CT fusion imaging emerges as a highly suitable non-invasive diagnostic modality, facilitating enhanced clinical follow-up and treatment.

Selective Recovery of Cathode Materials from Spent Lithium-Ion Battery Material with a Near-Room-Temperature Separation

Effective separation of cathode materials from the current collector is a critical step in recycling a spent lithium-ion battery (LIB). This typically necessitates the decomposition or dissolution of the organic binder, poly(vinylidene fluoride) (PVDF), to achieve efficient recovery of cathode materials. However, this process requires a high decomposition temperature, typically between 400 and 600 °C, and can lead to side reactions, such as current collector oxidation/brittleness, decomposition of cathode materials, and formation of metal fluorides. In this study, we propose that non-thermal plasma (NTP) treatment can be used to achieve an extremely high separation of cathode materials and aluminum current collector at near room temperature. Instead of relying on PVDF decomposition, which requires high temperatures, PVDF can be deactivated by partially breaking down long molecular chains with appropriate NTP conditions. With a total treatment time of around 2000 s and an environmental temperature of approximately 80 °C, minor side reactions can be avoided. The separation rate can reach up to 95.69%, and high-quality cathode materials can be obtained with only 0.02 wt % aluminum impurity content. This research could potentially offer a new approach toward minimizing recycling steps and reducing energy consumption in the recycling of spent LIBs. It could also be extended to the recovery of a broader range of electronic wastes.

Performance Evaluation of the uMI Panorama PET/CT System in Accordance with the National Electrical Manufacturers Association NU 2-2018 Standard

The uMI Panorama is a novel PET/CT system using silicon photomultiplier and application-specific integrated circuit technologies and providing exceptional spatial and time-of-flight (TOF) resolutions. The objective of this study was to assess the physical performance of the uMI Panorama in accordance with the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. Methods: Spatial resolution, sensitivity, count rate performance, accuracy, image quality, and TOF resolution were evaluated in accordance with the guidelines outlined in the NEMA NU 2-2018 standard. Energy resolution was determined using the same dataset acquired for the count rate performance evaluation. Images from a Hoffman brain phantom, a mini-Derenzo phantom, and 3 patient studies were evaluated to demonstrate system performance. Results: The transaxial spatial resolution at full width at half maximum was measured as 2.88 mm with a 1-cm offset from the center axial field of view. The sensitivity at the center axial field of view was 20.1 kcps/MBq. At an activity concentration of 73.0 kBq/mL, the peak noise-equivalent count rate (NECR) reached 576 kcps with a scatter fraction of approximately 33.2%. For activity concentrations at or below the peak NECR, the maximum relative count rate error among all slices remained consistently below 3%. When assessed using the NEMA image quality phantom, overall image contrast recovery ranged from 63.2% to 88.4%, whereas background variability ranged from 4.2% to 1.1%. TOF resolution was 189 ps at 5.3 kBq/mL and was consistently lower than 200 ps for activity concentrations at or below the peak NECR. The patient studies demonstrated that scans at 2 min/bed produced images characterized by low noise and high contrast. Clear delineation of nuclei, spinal cords, and other substructures of the brain was observed in the brain PET images. Conclusion: uMI Panorama, the world's first commercial PET system with sub-200-ps TOF resolution, demonstrated fine spatial and fast TOF resolutions, robust count rate performance, and high quantification accuracy across a wide range of activity levels. This advanced technology offers enhanced diagnostic capability for detecting small and low-contrast lesions while showing promising potential under high-count-rate imaging scenarios.

The PRIMARY Score: Diagnostic Performance and Added Value Compared With MRI in Detecting Clinically Significant Prostate Cancer

PURPOSE

Multiparametric MRI is the current standard for detecting clinically significant prostate cancer (csPCa). However, men with negative or equivocal MRI often undergo unnecessary biopsies due to concerns about false-negative results. The recently proposed 68 Ga-PSMA PET/CT-based PRIMARY score exhibited good diagnostic performance for csPCa. This study aimed to externally validate the performance of the PRIMARY score and evaluate its added diagnostic value to MRI triage in detecting csPCa.

PATIENTS AND METHODS

This retrospective cohort study included 431 men who underwent both 68 Ga-PSMA PET/CT and MRI before biopsy. Performance was assessed using the area under the receiver operating characteristic curve and the decision curve analysis. The PRIMARY score + MRI was considered positive for either PRIMARY score 3-5 or Prostate Imaging Reporting and Data System (PI-RADS) 4/5.

RESULTS

The prevalence of csPCa was 51.7% (223/431). The area under the receiver operating characteristic curve of the 5-level PRIMARY score for csPCa was significantly higher than that of MRI (0.873 vs 0.786, P < 0.001). For the entire group, sensitivity, specificity, positive predictive value, and negative predictive value of the PRIMARY score were 90.6%, 61.1%, 71.4%, and 85.8%, respectively, which outperformed 87.9%, 49.0%, 64.9%, and 79.1% of PI-RADS on MRI. The PRIAMRY score + MRI improved sensitivity (96.0% vs 87.9%, P < 0.001) and negative predictive value (91.5% vs 79.1%, P < 0.001) without compromising specificity and positive predictive value compared with MRI alone. This combined approach avoided 24.6% (106/431) of unnecessary biopsies, while missing 4.0% (9/223) of csPCa cases. The addition of the PRIMARY score in men with PI-RADS 1-3 showed a net benefit, but not in men with PI-RADS 4/5.

CONCLUSIONS

The PRIMARY score was superior to MRI in detecting csPCa, and its added diagnostic value was in men with negative or equivocal MRI results. The PRIMARY score + MRI improved negative predictive value and sensitivity for csPCa compared with MRI alone. Further prospective trials will validate whether men with clinical suspicion of csPCa but negative PRIMARY score + MRI can safely avoid unnecessary biopsies.

Injectable hydrogel with selenium nanoparticles delivery for sustained glutathione peroxidase activation and enhanced osteoarthritis therapeutics

Reactive oxygen burst in articular chondrocytes is a major contributor to osteoarthritis progression. Although selenium is indispensable role in the antioxidant process, the narrow therapeutic window, delicate toxicity margins, and lack of an efficient delivery system have hindered its translation to clinical applications. Herein, transcriptomic and biochemical analyses revealed that osteoarthritis was associated with selenium metabolic abnormality. A novel injectable hydrogel to deliver selenium nanoparticles (SeNPs) was proposed to intervene selenoprotein expression for osteoarthritis treatment. The hydrogels based on oxidized hyaluronic acid (OHA) cross-linked with hyaluronic acid-adipic acid dihydrazide (HA-ADH) was formulated to load SeNPs through a Schiff base reaction. The hydrogels were further incorporated with SeNPs, which exhibited minimal toxicity, mechanical properties, self-healing capability, and sustained drug release. Encapsulated with SeNPs, the hydrogels facilitated cartilage repair through synergetic effects of scavenging reactive oxygen species (ROS) and depressing apoptosis. Mechanistically, the hydrogel restored redox homeostasis by targeting glutathione peroxidase-1 (GPX1). Therapeutic outcomes of the SeNPs-laden hydrogel were demonstrated in an osteoarthritis rat model created by destabilization of the medial meniscus, including cartilage protection, subchondral bone sclerosis improvement, inflammation attenuation, and pain relief were demonstrated. These results highlight therapeutic potential of OHA/HA-ADH@SeNPs hydrogels, providing fundamental insights into remedying selenium imbalance for osteoarthritis biomaterial development.

Melanin-targeted [18F]-PFPN PET imaging may shed light for clear cell sarcoma

PURPOSE

Intracytoplasmic melanin pigment is a characteristic of clear cell sarcoma (CCS), which is a particularly deadly type of soft-tissue sarcoma. [18F]-N-(2-(diethylamino)ethyl)-5-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)picolinamide ([18F]-PFPN) is a positron emission tomography (PET) probe characterized by high melanin affinity. Therefore, this study aimed to investigate the feasibility of melanin-targeted [18F]-PFPN PET in patients with CCS.

METHODS

This prospective single-centre study recruited patients with pathologically confirmed CCS. [18F]-FDG PET/computed tomography and [18F]-PFPN PET/magnetic resonance imaging scans were performed within 1 week of each other. The lesion numbers and [18F]-FDG and [18F]-PFPN PET parameters (maximum standardized uptake value [SUVmax], mean standardized uptake value [SUVmean], metabolic/melanotic tumour volume [MTV/MLTV], and total lesion glycolysis/melanin [TLG/TLM]) were collected.

RESULTS

Three patients with CCS were recruited and received PET imaging. A total of 56 lesions were detected on [18F]-PFPN PET, including primary tumour and distant metastases. Identical lesions were not detected on [18F]-PFPN and [18F]-FDG PET. Twelve lesions (12/39, 30.77%) on [18F]-FDG imaging were missed on [18F]-PFPN, and 20 lesions (20/47, 42.55%) on [18F]-PFPN imaging were missed on [18F]-FDG. In quantitative analysis, the [18F]-FDG SUVmean (4.60 ± 3.24) was higher than the [18F]-PFPN SUVmean (3.0 ± 2.63) in all lesions (P = 0.01). No significant correlations were found between the SUVmax, SUVmean, MLTV/MTV, and TLM/TLG values of [18F]-PFPN and [18F]-FDG (P > 0.05).

CONCLUSION

Melanin-targeted [18F]-PFPN PET imaging is feasible for the diagnosis of CCS. Different imaging features were displayed on [18F]-PFPN and [18F]-FDG PET imaging, demonstrating the complementary role of the tracers. Combined use of the two imaging modalities would be preferred in patients with CCS.

CLINICAL TRIAL REGISTRATION

NCT05963035.

First-in-Humans PET Imaging of KRASG12C Mutation Status in Non-Small Cell Lung and Colorectal Cancer Patients Using [18F]PFPMD

Kirsten rat sarcoma (KRAS) mutations are an important marker for tumor-targeted therapy. In this study, we sought to develop a KRASG12C oncoprotein-targeted PET tracer and to evaluate its translational potential for noninvasive imaging of the KRASG12C mutation in non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) patients. Methods: [18F]PFPMD was synthesized on the basis of AMG510 (sotorasib) by attaching a polyethylene glycol chain to the quinazolinone structure. The binding selectivity and imaging potential of [18F]PFPMD were verified by cellular uptake, internalization, and blocking (H358: KRASG12C mutation; A549: non-KRASG12C mutation) studies, as well as by a small-animal PET/CT imaging study on tumor-bearing mice. Five healthy volunteers were enrolled to assess the safety, biodistribution, and dosimetry of [18F]PFPMD. Subsequently, 14 NSCLC or CRC patients with or without the KRASG12C mutation underwent [18F]PFPMD and [18F]FDG PET/CT imaging. The SUVmax of tumor uptake of [18F]PFPMD was measured and compared between patients with and without the KRASG12C mutation. Results: [18F]PFPMD was obtained with a high radiochemical yield, radiochemical purity, and stability. The protein-binding assay showed that [18F]PFPMD selectively binds to the KRASG12C protein. [18F]PFPMD uptake was significantly higher in H358 than in A549 and was decreased by pretreatment with AMG510 (H358 vs. A549: 3.22% ± 0.28% vs. 2.50% ± 0.25%, P < 0.05; block: 2.06% ± 0.13%, P < 0.01). Similar results were observed in tumor-bearing mice on PET imaging (H358 vs. A549: 3.93% ± 0.24% vs. 2.47% ± 0.26% injected dose/g, P < 0.01; block: 2.89% ± 0.29% injected dose/g; P < 0.05). [18F]PFPMD was safe in humans and was excreted primarily by the gallbladder and intestines. The whole-body effective dose was comparable to that of [18F]FDG. The accumulation of [18F]PFPMD in KRASG12C mutation tumors was significantly higher than that in non-KRASG12C mutation tumors (SUVmax: 3.73 ± 0.58 vs. 2.39 ± 0.22, P < 0.01) in NSCLC and CRC patients. Conclusion: [18F]PFPMD is a safe and promising PET tracer for noninvasive screening of the KRASG12C mutation status in NSCLC and CRC patients.

Head-to-Head Comparison of 68Ga-PSMA-11 with 68Ga-P137 in Patients with Suspected Prostate Cancer

P137 is a novel oxalyldiaminopropionic acid-urea-based prostate-specific membrane antigen (PSMA) targeting agent. This study compared the uptake patterns of 68Ga-P137 and the FDA-approved PET tracer 68Ga-PSMA-11 for diagnosing prostate cancer (PCa). Sixteen patients suspected of PCa were scanned by 68Ga-PSMA-11 and 68Ga-P137 PET/CT, respectively, followed by prospective analysis. The tumor-to-background ratio was calculated using normal prostate tissue, blood pool, muscle, and urine as backgrounds. Pathology or follow-up results were used to analyze uptake patterns of benign/malignant lesions and various organs. Thirteen patients were diagnosed with PCa and three with benign prostate diseases (BPD). The number and location of primary lesions, lymph node metastasis (LNM) (n = 25), bone metastasis (n = 30), and liver metastasis (n = 3) detected by the two tracers were identical. Maximum standardized uptake value (SUVmax), tumor/normal prostate ratio, as well as semiquantitative miPSMA-ES and PRIMARY diagnostic scores (P all >0.05) showed similar uptake levels of primary lesions between 68Ga-P137 and 68Ga-PSMA-11. Compared to 68Ga-P137, the SUVmax of 68Ga-PSMA-11 was significantly higher for bone metastasis, LNM, and liver metastasis (14.9 ± 7.2 vs 9.1 ± 4.4, 14.4 ± 5.0 vs 7.5 ± 2.4, 13.9 ± 2.0 vs 8.8 ± 2.4, P all <0.05). One-hour postinjection, SUVmax of the duodenum (9.4 ± 2.1 vs 16.2 ± 6.1), kidney (19.4 ± 4.3 vs 45.6 ± 20.9), and urine (14.1 ± 7.1 vs 42.1 ± 25.9) were significantly lower for 68Ga-P137 than for 68Ga-PSMA-11 (P all <0.05), whereas the radioactivity accumulation of blood pool and muscle (3.9 ± 0.5 vs 1.6 ± 0.4, 1.0 ± 0.1 vs 0.6 ± 0.1, P all <0.05) of 68Ga-P137 was significantly higher than 68Ga-PSMA-11. The uptake level of 68Ga-P137 has no significant difference from that of 68Ga-PSMA-11 in prostate primary lesions, and their imaging performances are visually equivalent for both primary and metastatic lesions, despite a higher blood pool and muscle background and a lower uptake in metastatic lesions. Due to the lower urine excretion of 68Ga-P137, primary prostate lesions near the urine can potentially be displayed clearer than 68Ga-PSMA-11.

A Prostate-Specific Membrane Antigen PET-Based Approach for Improved Diagnosis of Prostate Cancer in Gleason Grade Group 1: A Multicenter Retrospective Study

The preoperative Gleason grade group (GG) from transrectal ultrasound-guided prostate biopsy is crucial for treatment decisions but may underestimate the postoperative GG and miss clinically significant prostate cancer (csPCa), particularly in patients with biopsy GG1. In such patients, an SUVmax of at least 12 has 100% specificity for detecting csPCa. In patients with an SUVmax of less than 12, we aimed to develop a model to improve the diagnostic accuracy of csPCa. Methods: The study retrospectively included 56 prostate cancer patients with transrectal ultrasound-guided biopsy GG1 and an SUVmax of less than 12 from 2 tertiary hospitals. All [68Ga]Ga-PSMA-HBED-CC PET scans were centrally reviewed in Xijing Hospital. A deep learning model was used to evaluate the overlap of SUVmax (size scale, 3 cm) and the level of Gleason pattern (size scale, 500 μm). A diagnostic model was developed using the PRIMARY score and SUVmax, and its discriminative performance and clinical utility were compared with other methods. The 5-fold cross-validation (repeated 1,000 times) was used for internal validation. Results: In patients with GG1 and an SUVmax of less than 12, significant prostate-specific membrane antigen (PSMA) histochemical score (H-score) H-score overlap occurred among benign gland, Gleason pattern 3, and Gleason pattern 4 lesions, causing SUVmax overlap between csPCa and non-csPCa. The model of 10 × PRIMARY score + 2 × SUVmax exhibited a higher area under the curve (AUC, 0.8359; 95% CI, 0.7233-0.9484) than that found using only the SUVmax (AUC, 0.7353; P = 0.048) or PRIMARY score (AUC, 0.7257; P = 0.009) for the cohort and a higher AUC (0.8364; 95% CI, 0.7114-0.9614) than that found using only the Prostate Imaging Reporting and Data System (PI-RADS) score of 5-4 versus 3-1 (AUC, 0.7036; P = 0.149) and the PI-RADS score of 5-3 versus 2-1 (AUC, 0.6373; P = 0.014) for a subgroup. The model reduced the misdiagnosis of the PI-RADS score of 5-4 versus 3-1 by 78.57% (11/14) and the PI-RADS score of 5-3 versus 2-1 by 77.78% (14/18). The internal validation showed that the mean 5-fold cross-validated AUC was 0.8357 (95% CI, 0.8357-0.8358). Conclusion: We preliminarily suggest that the model of 10 × PRIMARY score + 2 × SUVmax may enhance the diagnostic accuracy of csPCa in patients with biopsy GG1 and an SUVmax of less than 12 by maximizing PSMA information use, reducing the misdiagnosis of the PI-RADS score, and thereby aiding in making appropriate treatment decisions.

PI-RADS-Based Segmented Threshold of PSMA-PET SUVmax Is Better than Traditional Fixed Threshold for Diagnosing Clinically Significant Prostate Cancer Especially for PI-RADS 3 Lesions

OBJECTIVES

Our purpose was to compare the performance of prostate-specific membrane antigen (PSMA)-positron emission tomography (PET) traditional fixed threshold (FT) and newly established Prostate Imaging Reporting and Data System (PI-RADS)-based segmented threshold (ST) for diagnosing clinically significant prostate cancer (csPCa).

METHODS

The study retrospectively included 218 patients who underwent multiparametric magnetic resonance imaging (mpMRI) and PSMA-PET examination for suspected prostate cancer (PCa) from January 2018 to November 2021. Lesions with Gleason score ≥ 3 + 4 were diagnosed as csPCa. In PSMA-PET maximum standardized uptake value (SUVmax), the FT for all the lesions and STs for lesions with different PI-RADS score for diagnosing csPCa were determined by receiver operating characteristic (ROC) curves analysis and compared with Z test. The McNemar test was used to compare sensitivity and specificity.

RESULTS

Among the 218 patients, there were 113 csPCa and 105 non-csPCa. The PSMA-PET FT was SUVmax > 5.3 (area under the curve, AUC = 0.842) and STs for PI-RADS 3/4/5 were SUVmax > 4.2/5.7/6.0 (AUCs = 0.870/0.867/0.882), respectively. The AUC of PSMA-PET ST was higher than that of PSMA-PET FT (0.872 vs. 0.842), especially for PI-RADS 3 (0.870 vs. 0.653). Multimodality diagnostic criteria combining PSMA-PET ST and PI-RADS scores of mpMRI was established and its AUC was higher than that of PSMA-PET ST (0.893 vs. 0.872) and significantly higher than that of PSMA-PET FT (0.893 vs. 0.842) with an improvement in sensitivity (93% vs. 78%, p < 0.05) without significantly sacrificing specificity (86% vs. 91%, p > 0.05).

CONCLUSIONS

For diagnosing csPCa, PI-RADS-based PSMA-PET segmented threshold achieved better performance than traditional fixed threshold, especially for PI-RADS 3 lesions. Multimodality diagnostic criteria demonstrated higher diagnostic performance than segmented threshold and significantly better than PSMA-PET fixed threshold for detecting csPCa.

68Ga-FAPI-04 PET for Surveillance of Anastomotic Recurrence in Postoperative Patients with Gastrointestinal Cancer: a Comparative Study with 18F-FDG PET

PURPOSE

This study aims to compare the diagnostic efficacy of 68Ga-FAPI-04 PET and 18F-FDG PET for detecting anastomotic recurrence in postoperative patients with gastrointestinal cancer, and to characterize the signal pattern over time at surgical wounds on both PET imaging.

METHODS

Gastrointestinal cancer patients who planned to 68Ga-FAPI-04 and 18F-FDG PET/CT imaging for postoperative surveillance were involved. The SUVmax at surgical wounds were assessed. Endoscopic pathology confirmed anastomotic recurrence or it was ruled out by imaging and clinical follow-up. The sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy of the two PET imaging in detecting anastomotic recurrence were compared. Relationships between tracer uptake at surgical wounds and postoperative time were also analyzed.

RESULTS

Compared with non-recurrent patients, the recurrent patients exhibited a significantly higher anastomotic SUVmax on 68Ga-FAPI-04 PET (SUVmax: 9.92 ± 4.36 vs. 2.81 ± 1.86, P = 0.002). Sensitivity, specificity, PPV, NPV, and accuracy of detecting anastomotic recurrence were 100.0%, 87.3%, 41.7%, 100.0%, and 88.3% for 68Ga-FAPI-04 PET, and 60.0%, 81.8%, 23.1%, 95.7%, and 80.0% for 18F-FDG PET, respectively. Although 68Ga-FAPI-04 PET signal at surgical wounds showed a slight trend to decrease with time, no statistical difference was observed over months post-surgery (P > 0.05).

CONCLUSIONS

Both tracers displayed high NPVs in identifying anastomotic recurrence with a higher sensitivity to 68Ga-FAPI-04. Tracer uptake at anastomotic sites does not decrease significantly over time, which results in low PPVs for both PET. Therefore, it is difficult to differentiate anastomotic recurrence from inflammation on either PET imaging.

Early protection against bone stress injuries by mobilization of endogenous targeted bone remodeling

Bone stress injuries are common overuse injuries, especially in soldiers, athletes, and performers. In contrast to various post-injury treatments, early protection against bone stress injuries can provide greater benefit. This study explored the early protection strategies against bone stress injuries by mobilization of endogenous targeted bone remodeling. The effects of various pharmaceutical/biophysical approaches, individual or combinational, were investigated by giving intervention before fatigue loading. We optimized the dosage and administration parameters and found that early intervention with pulsed electromagnetic field and parathyroid hormone (i.e., PEMF+PTH) resulted in the most pronounced protective effects among all the approaches against the bone stress injuries. In addition, the mechanisms by which the strategy mobilizes targeted bone remodeling and enhances the self-repair capacity of bone were systematically investigated. This study proposes strategies to reduce the incidence of bone stress injuries in high-risk populations (e.g., soldiers and athletes), particularly for those before sudden increased physical training.

Ameliorative effect of calcium poly(aspartic acid) (PASP-Ca) and calcium poly-γ-glutamic acid (γ-PGA-Ca) on soil acidity in different horizons

Soil acidification is a worldwide eco-environmental problem detrimental to plant growth and threatening food security. In this study, calcium poly(aspartic acid) (PASP-Ca) and calcium poly-γ-glutamic acid (γ-PGA-Ca) were obtained through cation exchange and used to mitigate soil acidity owing to high solubility and complexing capability. Three rates at 6.7, 13.4, and 20.1 g kg^-1, denoted as PASP-Ca1, PASP-Ca2, and PASP-Ca3, and γ-PGA-Ca (7.4 g kg^-1) were surface-applied and compared with conventional lime (CaCO₃, 2.5 g kg^-1) along with control in two soil layers (top soil 0-10 cm, subsoil 10-20 cm). After leaching, various soil properties and aluminum fractions were measured to assess their ameliorative performance and mechanisms. Although lime achieved the highest soil pH (6.91) in the topsoil followed by PASP-Ca and γ-PGA-Ca (pH: 5.57-6.33), it had less effect on subsoil increase (5.3) vs. PASP-Ca and γ-PGA-Ca (pH: 5.44-5.74). Surface-applied PASP-Ca demonstrated efficiency in elevating soil pH and reducing exchangeable acidity, mainly as exchangeable Al³⁺, whereas γ-PGA-Ca addition superiorly improved soil pH buffering capacity (pHBC). Moreover, PASP-Ca and γ-PGA-Ca addition improved organic carbon by 34.4-44.9%, available P by 4.80-20.71%, and cation exchange capacity (CEC) by 6.19-29.2%, thus greatly enhanced soil fertility. Ca²⁺ from polyAA-Ca promoted the displacement of exchangeable Al³⁺ or H⁺ from soil colloid, which were subsequently complexed or protonated and facilitated leaching. Additionally, the transformation into stable organo-aluminum fractions via complexation inhibited further hydrolysis. Under PASP-Ca or γ-PGA-Ca addition, the saturation of aluminum in cation exchange complex was reduced 2.91-7.81% compared to the control without addition amendments. Thus, PASP-Ca and γ-PGA-Ca can serve as potent ameliorants to alleviate soil acidity and aluminum toxicity for sustainable agricultural development.

3D directional gradient L0 norm minimization guided limited-view reconstruction in a dual-panel positron emission mammography

BACKGROUND

Dual-panel PET is often used for local organ imaging, especially breast imaging, due to its simple structure, high sensitivity, good in-plane resolution, and straightforward fusion with other imaging modalities. Nevertheless, because of data loss caused by the dual-panel structure, using conventional image reconstruction methods results in limited-view artifacts and low image quality in dual-panel positron emission mammography (PEM), which may seriously affect the diagnosis. To mitigate the limited-view artifacts in the dual-panel PEM, we propose a 3D directional gradient L₀ norm minimization (3D-DL₀) guided reconstruction method.

METHODS

The detailed derivation and reasonable simplification of the 3D-DL₀ algorithm are given first. Using this algorithm, we then obtain a prior image with edge recovery but contrast loss. To limit the solution space, the 3D-DL₀ prior is introduced into the Maximum a Posteriori reconstruction. Meanwhile, a space-invariant point spread function is also implemented to restore image contrast and boundaries. Finally, the reconstructed images with limited-view artifact suppression are obtained. The proposed method was evaluated using the data acquired from physical phantoms and patients with breast tumors on a commercial dual-panel PET system.

RESULTS

The qualitative and quantitative studies for phantom data and the blind reader study for clinical data show that the proposed method is more effective in reaching a balance between artifact elimination and image contrast improvement compared with various limited-view reconstruction methods. In addition, the iteration process of the method is proved convergent numerically.

CONCLUSIONS

The image quality improvement confirms the potential value of the proposed reconstruction algorithm to address the limited-view problem, and thus improve diagnostic accuracy in dual-panel PEM imaging.

A Simple Kit Formulation for Preparation and Exploratory Human Studies of a Novel 99mTc-Labeled Fibroblast Activation Protein Inhibitor Tracer for Imaging of the Fibroblast Activation Protein in Cancers

Fibroblast activation protein (FAP) is a potential target for tumor diagnosis and treatment because it is selectively expressed on the cell membrane of cancer-associated fibroblasts in most solid tumor stroma. The aim of this study was to develop a ^99mTc-labeled fibroblast activation protein inhibitor (FAPI) tracer, evaluate its imaging efficacy in nude mice, and further explore its biodistribution in healthy volunteers and uptake in tumor patients. An FAPI-derived ligand (DP-FAPI) containing d-proline was designed and synthesized as a linker, and a stable hydrophilic ^99mTc-labeled complex ([^99mTc]Tc-DP-FAPI) was obtained by kit formulation. In vitro cellular uptake and saturation binding assays were performed in FAP-transfected HT-1080 cells (FAP-HT-1080). The biodistribution was characterized, and micro-single-photon emission computed tomography (SPECT) imaging was performed in BALB/c nude mice bearing U87 MG tumors. Furthermore, a first-in-man application was performed in four healthy volunteers and three patients with gastrointestinal tumors. In vitro, the nanomolar K_d values of [^99mTc]Tc-DP-FAPI indicated that it had significantly high target affinity for FAP. Biodistribution and micro-SPECT imaging studies showed that [^99mTc]Tc-DP-FAPI exhibited high uptake and high tumor-to-nontargeted ratios. The calculated effective dose for [^99mTc]Tc-DP-FAPI was approximately <5 mSv in four healthy volunteers. In three patients with gastrointestinal tumors, [^99mTc]Tc-DP-FAPI quantitative SPECT/CT revealed high and reliable uptake. [^99mTc]Tc-DP-FAPI exhibited high selectivity and affinity for FAP in vitro. The safety and effectiveness of [^99mTc]Tc-DP-FAPI in primary tumor imaging have been confirmed by animal and clinical studies, revealing the potential clinical application value of this tracer.

Safety, Biodistribution, and Dosimetry Study of Meplazumab, a Potential COVID-19 Therapeutic Drug, with 131I-Labeling and SPECT Imaging

Coronavirus disease 2019 (COVID-19) is a serious threat to public health and is in urgent need of specific drugs. Meplazumab, a humanized monoclonal antibody targeting CD147, was confirmed to competitively block the binding between the spike of syndrome coronavirus 2 (SARS-CoV-2) and CD147, making meplazumab a promising candidate drug for COVID-19. In this study, biodistribution and dosimetry of 131I-labeled meplazumab were performed to further evaluate its potential as a therapeutic drug for COVID-19. 131I-meplazumab was both safe and tolerant in mice and healthy volunteers. A biodistribution study was performed in normal mice, and blood samples were used for pharmacokinetic analysis. Three healthy volunteers were included and subjected to single-photon-emission computed tomography (SPECT) imaging of 131I-meplazumab within 2 weeks. The distribution in mice and humans was consistent with the in vivo distribution of CD147. Biodistribution and SPECT imaging results exhibited that the liver was the organ with the highest uptake for both mice and humans. Deiodination of 131I-meplazumab can be observed in vivo, and taking Lugol's solution can protect the thyroid gland effectively. The pharmacokinetic characteristics of 131I-meplazumab in mice and humans best fit the two-compartment model. The clearance half-life (T1/2β) in mice and humans was 117.4 and 223.5 h, respectively. The results indicated that its pharmacokinetic properties in vivo were ideal. The effective dose calculated from healthy volunteers was 0.811 ± 0.260 mSv·MBq-1, which was twice the value calculated from mice. It was safe and feasible to perform human clinical imaging experiments using a diagnostic dose of 131I-meplazumab after thyroid closure by Lugol's solution. This study will provide more experimental basis for advancing the clinical translation of meplazumab and will be valuable in evaluating therapeutic interventions for patients with COVID-19, as well as providing a reference for clinical translation studies of other antibody drugs.

Comparison of [68Ga]Ga-FAPI and [18F]FDG uptake in patients with gastric signet-ring-cell carcinoma: a multicenter retrospective study

OBJECTIVE

In this study, we investigated the role of [⁶⁸Ga]Ga-FAPI PET imaging in the detection of primary and metastatic gastric signet-ring-cell carcinoma (GSRCC) and compared with [¹⁸F]FDG PET.

METHODS

This retrospective multicenter analysis included 34 patients with histologically confirmed GSRCCs from four medical centers. The maximum standard uptake value (SUV_max), tumor-to-background ratio (TBR), and diagnostic accuracy were compared between the two modalities. [¹⁸F]FDG and [⁶⁸Ga]Ga-FAPI uptakes were compared by using the Wilcoxon signed-rank test. McNemar's test was used to compare the diagnostic accuracy between the two techniques.

RESULTS

Data were analyzed from 27 paired PET/CT and 7 paired PET/MRI scans for 34 GSRCC patients (16 men and 18 women) who had a median age of 51 years (range: 25-85 years). [⁶⁸Ga]Ga-FAPI PET showed higher SUV_max and TBR values than did [¹⁸F]FDG PET in the primary tumors (SUV_max: 5.2 vs. 2.2, p = 0.001; TBR: 7.6 vs. 1.3, p < 0.001), involved lymph nodes (SUV_max: 6.8 vs. 2.5, p < 0.001; TBR: 5.8 vs. 1.3, p < 0.001), and bone and visceral metastases (SUV_max: 6.5 vs. 2.4, p < 0.001; TBR: 6.3 vs. 1.3, p < 0.001). In diagnostic performance, [⁶⁸Ga]Ga-FAPI PET exhibited higher sensitivity than [¹⁸F]FDG PET for detecting primary tumors (73% [16/22] vs. 18% [4/22], p < 0.001), local recurrences (100% [7/7] vs. 29% [2/7], p = 0.071), lymph node metastases (77% [59/77] vs. 23% [18/77], p < 0.001), and distant metastases (93% [207/222] vs. 39% [86/222], p < 0.001).

CONCLUSION

The results from this multicenter retrospective analysis justify the clinical use of [⁶⁸Ga]Ga-FAPI tracers for GSRCC diagnosis and staging.

KEY POINTS

• [⁶⁸Ga]Ga-FAPI PET/CT is a promising imaging modality for the detection of primary and metastatic disease and has implications for TNM staging in GSRCC. • In this multicenter study of 34 patients with GSRCC, [⁶⁸Ga]Ga-FAPI PET exhibited greater radiotracer uptake, tumor-to-background ratios, and diagnostic accuracy than [¹⁸F]FDG PET for detecting primary/recurrent tumors and metastatic lesions.

Plasma membrane flipping of Syntaxin-2 regulates its inhibitory action on insulin granule exocytosis

Enhancing pancreatic β-cell secretion is a primary therapeutic target for type-2 diabetes (T2D). Syntaxin-2 (Stx2) has just been identified to be an inhibitory SNARE for insulin granule exocytosis, holding potential as a treatment for T2D, yet its molecular underpinnings remain unclear. We show that excessive Stx2 recruitment to raft-like granule docking sites at higher binding affinity than pro-fusion syntaxin-1A effectively competes for and inhibits fusogenic SNARE machineries. Depletion of Stx2 in human β-cells improves insulin secretion by enhancing trans-SNARE complex assembly and cis-SNARE disassembly. Using a genetically-encoded reporter, glucose stimulation is shown to induce Stx2 flipping across the plasma membrane, which relieves its suppression of cytoplasmic fusogenic SNARE complexes to promote insulin secretion. Targeting the flipping efficiency of Stx2 profoundly modulates secretion, which could restore the impaired insulin secretion in diabetes. Here, we show that Stx2 acts to assist this precise tuning of insulin secretion in β-cells, including in diabetes.

Case report: Long response to PD-1 blockade after failure of trastuzumab plus chemotherapy in advanced Epstein-Barr virus-associated gastric cancer

Background

Trastuzumab-containing chemotherapy is the first-line treatment for advanced gastric cancer (GC) with HER2 positive. Although PD-1 inhibitors significantly improved the outcome of GC patient’s refractory to previous chemotherapy regimens, few studies explore the role of anti-PD-1 therapy overcomes resistance to trastuzumab plus chemotherapy in advanced Epstein-Barr Virus-associated gastric cancer (EBVaGC) with PD-L1 and HER2 positive.

Case Presentation

We report a case of advanced EBVaGC in a 45-year-old man presenting with fatigue, dysphagia, and weight loss for several months. Initial endoscopy revealed a large tumor at the gastroesophageal junction. Computed tomography revealed GC accompanied by multiple lymph nodes and hepatic and pulmonary metastases. The immunohistochemistry indicated that HER-2 and PD-L1 were overexpressed, and tumor cells were positive for EBV-encoded small RNA (EBER) by in situ hybridization. Trastuzumab plus DCS was started as first-line chemotherapy with a PFS of 4 months and shifted to trastuzumab plus FOLFIRI or gemcitabine as second-/third-line therapy. After five-cycle nivolumab monotherapy, the patient received partial response and was treated with total radical gastrectomy plus sequential radiotherapy. He continued the postoperative immunotherapy over 30 cycles with a PFS of 28 months. Due to a new abdominal lymph node metastasis confirmed by PET-CT, he received toripalimab as the next-line treatment and achieved complete remission as the best objective response.

Summary

We presented an advanced HER2-positive EBVaGC patient with PD-L1 high expression, refractory to trastuzumab plus chemotherapy, and had a durable clinical benefit sequence with a single dose of the PD-1 inhibitor.

Organic-inorganic calcium lignosulfonate compounds for soil acidity amelioration

Soil acidification is a problem widely occurring worldwide, which severely threaten food security and agricultural sustainability. Calcium lignosulfonate (CaLS), a cheap and ecofriendly compound, is used for the first time to amend acid soil by utilizing its unique organic and inorganic functional moieties simultaneously. Both column leaching and incubation experiments were conducted to investigate the comparative effects of CaLS (four rates at 5, 10, 15, 20 g kg^-1) and compared with conventional amendments, including gypsum (5 g kg^-1), lignin (5 g kg^-1), L + G (each at 5 g kg^-1), and control. The soil pH, exchangeable acidity and base cations, organic carbon, and different Al fractions were determined to unravel the ameliorative performance and mechanism of the treatments. Regardless of application modes and dosages, the results demonstrated that CaLS incorporation significantly increased soil pH, exchangeable Ca²⁺, cation exchange capacity, and organic carbon and decreased the contents of exchangeable acidity, especially exchangeable Al³⁺. The ameliorative mechanism was that amendment material led to the displacement of H⁺ and Al³⁺ off soil colloids by Ca²⁺. These released H⁺ and Al³⁺ which complexed with lignosulfonate anions into soluble organo-Al were all quickly leached from the soil column. The CaLS addition enhanced the transformation of exchangeable Al³⁺ and low-to-medium organo-Al complexes into highly stable organically bound fractions and immobilized into the soil. The complexing of CaLS functional groups with Al³⁺ impeded Al³⁺ from undergoing hydrolysis to produce more H⁺. As an environmental-friendly material, CaLS can be a promising amendment for soil acidity and Al toxicity amelioration.

DH-Mammo PET: a dual-head positron emission mammography system for breast imaging

Objective: To develop a simultaneous PET-Optical (OPET) breast imaging dual-head PET subsystem, called DH-Mammo PET, for accurate, early diagnosis and efficacy assessment of breast cancer with high resolution and sensitivity. Approach: We developed a breast-dedicated PET based on LYSO crystal, silicon photomultiplier array and multi-voltage threshold sampling technique. It consists of two detector heads, each with a detection area of 216 mm × 145.5 mm. The distance between the detector heads is fixed at 120 mm. In order to extract coincidences and correct data, GPU-based software coincidence processing, random, scatter, normalization, gap-filling and attenuation corrections were applied in turn. The images were reconstructed using maximum likelihood expectation maximization with depth of interaction (DOI) modeling. The performance of DH-Mammo PET was evaluated referring to NEMA NU 4-2008, NU 2-2007 and Chinese industry recommended standard YY/T 1835-2022. Besides, several clinical patient images of DH-Mammo PET were compared with those of a whole-body PET/CT. Main results: The energy resolution was 14.5%, and time resolution was < 1.31 ns. Indicated by the 22Na point source imaging, its spatial resolution was 2.60 mm (5.40 mm), 1.00 mm (1.04 mm), and 0.96 mm (0.93 mm) in the X, Y and Z directions, respectively, using the system response matrix with (without) DOI modeling. Indicated by the Derenzo phantom imaging, the spatial resolution was ~3.0 mm, <1.2 mm, and <1.2 mm in the X, Y and Z directions. The system sensitivity was 6.87%, 4.89% and 3.37% with an energy window of 100-800, 250-750 and 350-650 keV, respectively. The scatter fraction was 26.43%, and the peak NECR was 162.6 kcps at 24.1 MBq for the modified rat-like phantom. As for the recovery coefficients, they ranged from 0.15 to 1.04 for rods between 1 mm and 5 mm obtained with a NEMA image quality phantom. The spill-over ratio for the air-filled and water-filled chamber was 0.05 and 0.11, respectively. DH-Mammo PET can provide more image details in clinical experiments and fulfil a fast scan with 60s-120 s acquisition time. Significance: Good spatial resolution and high sensitivity of DH-Mammo PET would enable fast and accurate PET imaging of the breast. Besides, combining the DH-Mammo PET with the diffuse optical tomography would make full use of tumor metabolic imaging and tissue endogenous optical imaging, which would improve the accuracy of early clinical diagnosis of small lesions of breast cancers.

Configurational path of successful entrepreneurship based on open government data: a QCA analysis

Purpose

In the era of big data, data have become an essential factor of production. In the context of open government data (OGD), encouraging the commercial development of OGD is significant for promoting mass innovation and entrepreneurship. This study aims to explore the configurational impact of data supply, external environment and entrepreneurial foundation on data-driven entrepreneurship.

Design/methodology/approach

This research used a fuzzy set qualitative comparative analysis (fsQCA). Fourteen start-ups using OGD were taken as a case sample.

Findings

This study produces two paths to achieving high entrepreneurial performance, one is a financing-enhanced entrepreneurial path and the other is a data-driven entrepreneurial path. Besides, four conditions are necessary for high performance of OGD-based entrepreneurship: good data quality, mature legal environment, favorable market environment and abundant big data entrepreneurial talents.

Practical implications

The findings have important practical implications for formulating policies related to promoting the application of government open data and innovation and entrepreneurship in terms of strengthening top-level design, improving the legal environment, developing the data market and cultivating entrepreneurial talents.

Originality/value

Although many studies have been conducted on OGD, studies on the paths to successful entrepreneurship based on OGD are limited. In this study, this issue is investigated from a configurational perspective by using the fsQCA technique.

A Brain-Controlled Vehicle System Based on Steady State Visual Evoked Potentials

In this paper, we propose a human-vehicle cooperative driving system. The objectives of this research are twofold: (1) providing a feasible brain-controlled vehicle (BCV) mode; (2) providing a human-vehicle cooperative control mode. For the first aim, through a brain-computer interface (BCI), we can analyse the EEG signal and get the driving intentions of the driver. For the second aim, the human-vehicle cooperative control is manifested in the BCV combined with the obstacle detection assistance. Considering the potential dangers of driving a real motor vehicle in the outdoor, an obstacle detection module is essential in the human-vehicle cooperative driving system. Obstacle detection and emergency braking can ensure the safety of the driver and the vehicle during driving. EEG system based on steady-state visual evoked potential (SSVEP) is used in the BCI. Simulation and real vehicle driving experiment platform are designed to verify the feasibility of the proposed human-vehicle cooperative driving system. Five subjects participated in the simulation experiment and real the vehicle driving experiment. The outdoor experimental results show that the average accuracy of intention recognition is 90.68 ± 2.96% on the real vehicle platform. In this paper, we verified the feasibility of the SSVEP-based BCV mode and realised the human-vehicle cooperative driving system.

An efficient anoxic/aerobic/aerobic/anoxic process for domestic sewage treatment: From feasibility to application

In this paper, the anoxic/aerobic/aerobic/anoxic (AOOA) process was proposed using fixed biofilms in a continuous plug-flow multi-chamber reactor, and no sludge reflux operation was performed during the 190 days of operation. The reactor volume ratio of 1.5:2:1.5:1 (A/O/O/A) with the dissolved oxygen (DO) concentration of 2 mg L⁻¹ in the aerobic zone was the optimal condition for reactor operation. According to the results obtained from the treatment of real domestic sewage, when the hydraulic retention time (HRT) was 6 h, the effluent of the reactor could meet the discharge standard even in cold conditions (13°C). Specifically, the elemental-sulfur-based autotrophic denitrification (ESAD) process contributed the most to the removal of total inorganic nitrogen (TIN) in the reactor. In addition, the use of vibration method was helpful in removing excess sludge from the biofilms of the reactor. Overall, the AOOA process is an efficient and convenient method for treating domestic sewage.

Denitrification Performance in Packed-Bed Reactors Using Novel Carbon-Sulfur-Based Composite Filters for Treatment of Synthetic Wastewater and Anaerobic Ammonia Oxidation Effluent

To avoid nitrate pollution in water bodies, two low-cost and abundant natural organic carbon sources were added to make up the solid-phase denitrification filters. This study compared four novel solid-phase carbon-sulfur-based composite filters, and their denitrification abilities were investigated in laboratory-scale bioreactors. The filter F₄ (mixture of elemental sulfur powder, shell powder, and peanut hull powder with a mass ratio of 6:2.5:1.5) achieved the highest denitrification ability, with an optimal nitrate removal rate (NRR) of 723 ± 14.2 mg NO₃^–-N⋅L^–1⋅d^–1 when the hydraulic retention time (HRT) was 1 h. The HRT considerably impacted effluent quality after coupling of anaerobic ammonium oxidation (ANAMMOX) and solid-phase-based mixotrophic denitrification process (SMDP). The concentration of suspended solids (SS) of the ANAMMOX effluent may affect the performance of the coupled system. Autotrophs and heterotrophs were abundant and co-existed in all reactors; over time, the abundance of heterotrophs decreased while that of autotrophs increased. Overall, the SMDP process showed good denitrification performance and reduced the sulfate productivity in effluent compared to the sulfur-based autotrophic denitrification (SAD) process.

Denitrification performance of sulfur-based autotrophic denitrification and biomass‑sulfur-based mixotrophic denitrification in solid-phase denitrifying reactors using novel composite filters

Both the elemental sulfur-based autotrophic denitrification (ESAD) and the biomass‑sulfur-based mixotrophic (simultaneous autotrophic and heterotrophic) denitrification processes (BSMD) are efficient methods for removing nitrate from wastewater. However, a comparative analysis of the denitrification capacity of the BSMD and ESAD in the packed bed reactors is still lacking. In this paper, corncob powder was selected as the biomass source to prepare biomass‑sulfur-based composite filter (BSCF) for the BSMD process. The denitrification performances of the three identical lab-scale bioreactors packed with varying elemental sulfur-based composite filters (ESCFs) were compared under varying loading conditions, and the optimal ESCF of the ESAD system was 2:1 by weight ratio of sulfur powder to shell powder. In pilot-scale experiments, the results showed that BSCF could decrease the sulfate productivity and gave better denitrification performance than the ESCF with the optimal nitrate removal rate (NRR) of 504 ± 12.3 mg NO₃^--N·L^-1·d^-1. In addition, the two-stage flushing strategy (for the removal of aged sludge) can effectively improve the denitrification capacity, while the denitrification will be inhibited when the influent dissolved oxygen concentration was higher than 4.5 mg L^-1. Moreover, the heterotrophs and autotrophs were abundant in the reactors. Over time, the abundance of autotrophs increased while that of heterotrophs decreased. Overall, BSCF could be a promising and economic technology to improve the effluent quality.

PET/CT Based EGFR Mutation Status Classification of NSCLC Using Deep Learning Features and Radiomics Features

Purpose: This study aimed to compare the performance of radiomics and deep learning in predicting EGFR mutation status in patients with lung cancer based on PET/CT images, and tried to explore a model with excellent prediction performance to accurately predict EGFR mutation status in patients with non-small cell lung cancer (NSCLC). Method: PET/CT images of 194 NSCLC patients from Xijing Hospital were collected and divided into a training set and a validation set according to the ratio of 7:3. Statistics were made on patients' clinical characteristics, and a large number of features were extracted based on their PET/CT images (4306 radiomics features and 2048 deep learning features per person) with the pyradiomics toolkit and 3D convolutional neural network. Then a radiomics model (RM), a deep learning model (DLM), and a hybrid model (HM) were established. The performance of the three models was compared by receiver operating characteristic (ROC) curves, sensitivity, specificity, accuracy, calibration curves, and decision curves. In addition, a nomogram based on a deep learning score (DS) and the most significant clinical characteristic was plotted. Result: In the training set composed of 138 patients (64 with EGFR mutation and 74 without EGFR mutation), the area under the ROC curve (AUC) of HM (0.91, 95% CI: 0.86-0.96) was higher than that of RM (0.82, 95% CI: 0.75-0.89) and DLM (0.90, 95% CI: 0.85-0.95). In the validation set composed of 57 patients (32 with EGFR mutation and 25 without EGFR mutation), the AUC of HM (0.85, 95% CI: 0.77-0.93) was also higher than that of RM (0.68, 95% CI: 0.52-0.84) and DLM (0.79, 95% CI: 0.67-0.91). In all, HM achieved better diagnostic performance in predicting EGFR mutation status in NSCLC patients than two other models. Conclusion: Our study showed that the deep learning model based on PET/CT images had better performance than radiomics model in diagnosing EGFR mutation status of NSCLC patients based on PET/CT images. Combined with the most statistically significant clinical characteristic (smoking) and deep learning features, our hybrid model had better performance in predicting EGFR mutation types of patients than two other models, which could enable NSCLC patients to choose more personalized treatment schemes.

Combined Probe Strategy to Increase the Enzymatic Digestion Rate and Accelerate the Renal Radioactivity Clearance of Peptide Radiotracers

High and sustained renal radioactivity accumulation is a major challenge in peptide-based radionuclide imaging and therapy. However, neutral endopeptidase (NEP)-based enzymatic hydrolysis to release and excrete the radioactive fragments has been proven to be an effective and promising way to reduce renal accumulation. Despite the improvement, the effect is still far from being satisfactory. To further reduce kidney uptake, we studied the relationship between the enzymatic reaction rate and the substrate concentration and came up with a combined probe strategy. Model compounds Boc-MVK-Dde and Boc-MFK-Dde were used for an in vitro enzymatic digestion study. NOTA-Exendin 4 and NOTA-MVK-Exendin 4 were labeled with ⁶⁴Cu for in vivo dose-dependent micro-positron emission tomography (PET) studies. Groups 1 and 2 were injected with 0.2 and 0.8 nmol of ⁶⁴Cu-NOTA-Exendin 4, respectively. Groups 3-6 were injected with 0.2, 0.8, 1.0, and 1.4 nmol of ⁶⁴Cu-NOTA-MVK-Exendin 4, respectively. Groups 7 and 8 were co-injected with 0.2 nmol of ⁶⁴Cu-NOTA-MVK-Exendin 4 and NOTA-MVK-PEG5K (1.3 and 2.6 nmol). The radioactivity uptakes were determined and compared within and among the groups. The in vitro cleavage study for both Boc-MVK-Dde and Boc-MFK-Dde indicated that within a certain concentration range, the enzyme digestion rate increased with increasing substrate concentration. The microPET images showed that the renal clearance could be accelerated significantly by increasing the injection dose of ⁶⁴Cu-NOTA-MVK-Exendin 4, with the kidney uptakes being 60.98, 43.01, and 16.10 % ID/g at 1 h for groups 3, 4 and 5, respectively. Unfortunately, the tumor uptakes were also significantly inhibited as the injected dose of the tracer increased. However, with the co-injection of NOTA-MVK-PEG5K, the renal accumulation was significantly decreased without hampering the tumor uptake. As a result, the tumor-to-kidney ratios were significantly improved, which were 1.93, 3.47, 1.74, and 3.38 times that of group 3 at 1, 4, 24, and 48 h, respectively. The enzymatic reaction rate of NEP is dependent on the concentration of the substrates both in vitro and in vivo. The combined probe strategy developed in this study can dramatically reduce the renal accumulation of a peptide radioligand without affecting the tumor uptake, which shows great potential in peptide-based radiotheranostics.

Unusual Diffuse Ground-Glass Opacities in the Lungs on 18F-FDG PET/CT: A Case of Melanoma With Pulmonary Metastasis

ABSTRACT

A 61-year-old man was diagnosed with a malignant melanoma and underwent a resection; he presented with progressive dyspnea after treatment with interferon for 2 months. 18F-FDG PET/CT scan revealed diffuse ground-glass opacities (GGOs) in both lungs with mildly elevated 18F-FDG uptake, similar to that observed with interstitial inflammation. However, a lung biopsy confirmed that the diffuse GGOs were pulmonary metastases of melanoma and were positive for the BRAF mutation. The diffuse GGOs and the progressive dyspnea disappeared after BRAF-targeted therapy. This represents an unusual case of lung metastases from melanoma, mistakenly interpreted as lung inflammation induced by immunotherapy.

Establishment and Optimization of Radiomics Algorithms for Prediction of KRAS Gene Mutation by Integration of NSCLC Gene Mutation Mutual Exclusion Information

Purpose: To assess the significance of mutation mutual exclusion information in the optimization of radiomics algorithms for predicting gene mutation.

Methods: We retrospectively analyzed 258 non-small cell lung cancer (NSCLC) patients. Patients were randomly divided into training (n = 180) and validation (n = 78) cohorts. Based on radiomics features, radiomics score (RS) models were developed for predicting KRAS proto-oncogene mutations. Furthermore, a composite model combining mixedRS and epidermal growth factor receptor (EGFR) mutation status was developed.

Results: Compared with CT model, the PET/CT radiomics score model exhibited higher AUC for predicting KRAS mutations (0.834 vs. 0.770). By integrating EGFR mutation information into the PET/CT RS model, the AUC, sensitivity, specificity, and accuracy for predicting KRAS mutations were all elevated in the validation cohort (0.921, 0.949, 0.872, 0.910 vs. 0.834, 0.923, 0.641, 0.782). By adding EGFR exclusive mutation information, the composite model corrected 64.3% false positive cases produced by the PET/CT RS model in the validation cohort.

Conclusion: Integrating EGFR mutation status has potential utility for the optimization of radiomics models for prediction of KRAS gene mutations. This method may be used when repeated biopsies would carry unacceptable risks for the patient.

Farnesoid X receptor agonist attenuates subchondral bone osteoclast fusion and osteochondral pathologies of osteoarthritis via suppressing JNK1/2/NFATc1 pathway

Osteoarthritis (OA) is a prevalent degenerative disease of the joint, featured by articular cartilage destruction and subchondral bone marrow lesions. Articular cartilage and subchondral bone constitute an osteochondral unit that guarantees joint homeostasis. During OA initiation, activated osteoclasts in subchondral bone ultimately result in impaired capacities of the subchondral bone in response to mechanical stress, followed by the degradation of overlying articular cartilage. Thus, targeting osteoclasts could be a potential therapeutic option for treating OA. Here, we observed that farnesoid X receptor (FXR) expression and osteoclast fusion and activity in subchondral bone were concomitantly changed during early-stage OA in the OA mouse model established by anterior cruciate ligament transection (ACLT). Then, we explored the therapeutic effects of FXR agonist GW4064 on the osteochondral pathologies in ACLT mice. We showed that GW4064 obviously ameliorated subchondral bone deterioration, associated with reduction in tartrate-resistant acid phosphatase (TRAP) positive multinuclear osteoclast number, as well as articular cartilage degradation, which were blocked by the treatment with FXR antagonist Guggulsterone. Mechanistically, GW4064 impeded osteoclastogenesis through inhibiting subchondral bone osteoclast fusion via suppressing c-Jun N-terminal kinase (JNK) 1/2/nuclear factor of activated T-cells 1 (NFATc1) pathway. Taken together, our results present evidence for the protective effects of GW4064 against OA by blunting osteoclast-mediated aberrant subchondral bone loss and subsequent cartilage deterioration. Therefore, GW4064 demonstrates the potential as an alternative therapeutic option against OA for further drug development.

Compact fiber-free parallel-plane multi-wavelength diffuse optical tomography system for breast imaging

To facilitate the clinical applicability of the diffuse optical inspection device, a compact multi-wavelength diffuse optical tomography system for breast imaging (compact-DOTB) with a fiber-free parallel-plane structure was designed and fabricated for acquiring three-dimensional optical properties of the breast in continuous-wave mode. The source array consists of 56 surface-mounted micro light-emitting diodes (LEDs), each integrating three wavelengths (660, 750, and 840 nm). The detector array is arranged with 56 miniaturized surface-mounted optical sensors, each encapsulating a high-sensitivity photodiode (PD) and a low-noise current amplifier with a gain of 24×. The system provides 3,136 pairs of source-detector measurements at each wavelength, and the fiber-free design largely ensures consistency between source/detection channels while effectively reducing the complexity of system operation and maintenance. We have evaluated the compact-DOTB system's characteristics and demonstrated its performance in terms of reconstruction positioning accuracy and recovery contrast with breast-sized phantom experiments. Furthermore, the breast cancer patient studies have been carried out, and the quantitative results indicate that the compact-DOTB system is able to observe the changes in the functional tissue components of the breast after receiving the neoadjuvant chemotherapy (NAC), demonstrating the great potential of the proposed compact system for clinical applications, while its cost and ease of operation are competitive with the existing breast-DOT devices.

Controlled growth factor delivery system with osteogenic-angiogenic coupling effect for bone regeneration

Objective

Bone regeneration involves a coordinated cascade of events that are regulated by several cytokines and growth factors, among which bone morphogenic protein-2 (BMP-2), vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) play important roles. In this study, we investigated the effects of dual release of the three growth factors on bone regeneration in femur defects.

Methods

A composite consisting of Gelatin microparticles loaded with VEGF/FGF-2 and poly(lactic-co-glycolic acid)-poly(ethylene glycol)-carboxyl (PLGA-PEG-COOH) microparticles loaded with BMP-2 encapsulated in a nano hydroxyapatite-poly actic-co-glycolic acid (nHA-PLGA) scaffold was prepared for the dual release of the growth factors.

Results

On the 14th day, decreased release rate of BMP-2 compared with FGF-2 and VEGF was observed. However, after 14 days, compared to FGF-2 and VEGF, BMP-2 showed an increased release rate. Controlled dual release of BMP-2 and VEGF, FGF-2 resulted in a significant osteogenic differentiation of bone mesenchymal stem cells (BMSCs). Moreover, effects of the composite scaffold on functional connection of osteoblast-vascular cells during bone development were evaluated. The synergistic effects of dual delivery of growth factors were shown to promote the expression of VEGF in BMSCs. Increased secretion of VEGF from BMSCs promoted the proliferation and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) in the co-culture system. At 12 weeks after implantation, blood vessel and bone formation were analyzed by micro-CT and histology. The composite scaffold significantly promoted the formation of blood vessels and new bone in femur defects.

Conclusions

These findings demonstrate that dual delivery of angiogenic factors and osteogenic factors from Gelatin and PLGA-PEG-COOH microparticles-based composite scaffolds exerted an osteogenic-angiogenic coupling effect on bone regeneration. This approach will inform on the development of appropriate designs of high-performance bioscaffolds for bone tissue engineering.

Imaging Insulin Granule Dynamics in Human Pancreatic β-Cells Using Total Internal Reflection Fluorescence (TIRF) Microscopy

Due to the ultra-thin optical sectioning capability of exclusively illuminating space at the interface where total internal reflection occurs, the TIRF microscope has been indispensable for monitoring biological processes adjacent to the plasma membrane with excellent signal-to-noise ratio. Insulin-containing granules fuse with the plasma membrane to release contents within hundreds of milliseconds, which involves well-orchestrated assembly of SNARE complex and associated proteins. A video-rate multiple-color TIRF microscope offers the unique opportunity to visualize single secretory granule docking and fusion dynamics and can also map its regulators with high spatiotemporal resolution. Here, we describe the basic principles and practical implementation of a fast dual-color TIRF microscope, detailing a how-to guide on imaging and analysis of insulin granule dynamics in human β-cells.

Exploration and verification of the feasibility of the sulfur-based autotrophic denitrification integrated biomass-based heterotrophic denitrification systems for wastewater treatment: From feasibility to application

The sulfur-based autotrophic denitrification (SAD) and the solid organic carbon-based denitrification processes are both efficient techniques to remove nitrate from wastewater, and the hydrogen ions generated by the SAD process would be consumed in the heterotrophic denitrification process. Therefore, it is possible to improve the denitrification capacity when the solid organic carbon was added into a SAD reactor. In this study, corncob powder and sawdust powder were selected as solid organic carbon sources, and the sulfur-based autotrophic denitrification integrated biomass-based heterotrophic denitrification system was formed (SBD). The laboratory and field experiments showed that SBD could shorten the start-up period, decrease the sulfate productivity, and maintain a good denitrification performance when treated wastewater. According to the field experiment results, when the HRT was 1 h, the effluent total nitrogen (TN) concentration was always lower than 15 mg L^-1. In addition, nitrite inhibition was observed when the concentration of nitrite in the reactors reached above 30 mg L^-1. The mixture of elemental sulfur powder, shell powder, corncob powder, and sawdust powder with a mass ratio of 6:2:1:1 was the optimal filter for the SBD system, with an average nitrate reduction rate (NAR) of 420 mg NO₃^-N·L^-1·d^-1 obtained at the end of the study. During the whole operation, the major autotrophs in the SBD systems were Thermomonas, Ferritrophicum, and Thiobacillus, while the major heterotrophs were Saprospiraceae, Ferruginibacter, Dokdonella, and Simplicispira. Overall, the SBD system was a feasible and practically favorable way to remove nitrate from wastewater.

A Data Self-Calibration Method Based on High-Density Parallel Plate Diffuse Optical Tomography for Breast Cancer Imaging

When performing the diffuse optical tomography (DOT) of the breast, the mismatch between the forward model and the experimental conditions will significantly hinder the reconstruction accuracy. Therefore, the reference measurement is commonly used to calibrate the measured data before the reconstruction. However, it is complicated to customize corresponding reference phantoms based on the breast shape and background optical parameters of different subjects in clinical trials. Furthermore, although high-density (HD) DOT configuration has been proven to improve imaging quality, a large number of source-detector (SD) pairs also increase the difficulty of multi-channel correction. To enhance the applicability of the breast DOT, a data self-calibration method based on an HD parallel-plate DOT system is proposed in this paper to replace the conventional relative measurement on a reference phantom. The reference predicted data can be constructed directly from the measurement data with the support of the HD-DOT system, which has nearly a hundred sets of measurements at each SD distance. The proposed scheme has been validated by Monte Carlo (MC) simulation, breast-size phantom experiments, and clinical trials, exhibiting the feasibility in ensuring the quality of the DOT reconstruction while effectively reducing the complexity associated with relative measurements on reference phantoms.

Klotho upregulates the interaction between RANK and TRAF6 to facilitate RANKL-induced osteoclastogenesis via the NF-κB signaling pathway

Background

α-Klotho (Klotho) plays a wide range of roles in pathophysiological processes, such as low-turnover osteoporosis observed in klotho mutant mice (kl/kl mice). However, the precise function and underlying mechanism of klotho during osteoclastogenesis are not fully understood. Here, we investigated the effects of klotho on osteoclastogenesis induced by receptor activator of nuclear factor kappa-B ligand (RANKL).

Methods

The effects of klotho deficiency on osteoclastogenesis were explored using kl/kl mice both in vivo and in vitro. In in vitro experiments, lentivirus transfection, real-time quantitative PCR (RT-qPCR) analysis, western blot analysis, immunostaining, RNA-seq analysis, differential pathway analysis, Energy-based protein docking analysis and co-immunoprecipitation were used for deeply investigating the effects of klotho on RANKL-induced Osteoclastogenesis and the underlying mechanism.

Results

We found that klotho deficiency impaired osteoclastogenesis. Furthermore, in vitro studies revealed that klotho facilitated osteoclastogenesis and upregulated the expression of c-Fos and nuclear factor of activated T cells cytoplasmic 1 (NFATc1) during osteoclastogenesis. Mechanistically, we confirmed that klotho co-localized with nuclear factor kappa B (RANK) and facilitated the interaction between activated RANK and TNFR-associated factor 6 (TRAF6), thus klotho exerts its function in osteoclastogenesis through the activation of the NF-κB signaling pathway.

Conclusions

Klotho promotes RANKL-induced osteoclastogenesis through upregulating the interaction between RANK and TARF6, Targeting on klotho may be an attractive therapeutic method for osteopenic diseases.