Background
The delineation of brain arteriovenous malformations (bAVMs) is crucial for subsequent treatment planning. Manual segmentation is time‐consuming and labor‐intensive. Applying deep learning ...to automatically detect and segment bAVM might help to improve clinical practice efficiency.
Purpose
To develop an approach for detecting bAVM and segmenting its nidus on Time‐of‐flight magnetic resonance angiography using deep learning methods.
Study Type
Retrospective.
Subjects
221 bAVM patients aged 7–79 underwent radiosurgery from 2003 to 2020. They were split into 177 training, 22 validation, and 22 test data.
Field Strength/Sequence
1.5 T, Time‐of‐flight magnetic resonance angiography based on 3D gradient echo.
Assessment
The YOLOv5 and YOLOv8 algorithms were utilized to detect bAVM lesions and the U‐Net and U‐Net++ models to segment the nidus from the bounding boxes. The mean average precision, F1, precision, and recall were used to assess the model performance on the bAVM detection. To evaluate the model's performance on nidus segmentation, the Dice coefficient and balanced average Hausdorff distance (rbAHD) were employed.
Statistical Tests
The Student's t‐test was used to test the cross‐validation results (P < 0.05). The Wilcoxon rank test was applied to compare the median for the reference values and the model inference results (P < 0.05).
Results
The detection results demonstrated that the model with pretraining and augmentation performed optimally. The U‐Net++ with random dilation mechanism resulted in higher Dice and lower rbAHD, compared to that without that mechanism, across varying dilated bounding box conditions (P < 0.05). When combining detection and segmentation, the Dice and rbAHD were statistically different from the references calculated using the detected bounding boxes (P < 0.05). For the detected lesions in the test dataset, it showed the highest Dice of 0.82 and the lowest rbAHD of 5.3%.
Data Conclusion
This study showed that pretraining and data augmentation improved YOLO detection performance. Properly limiting lesion ranges allows for adequate bAVM segmentation.
Level of Evidence
4
Technical Efficacy Stage
1
Current therapy does not provide significant benefits for patients with chronic stroke. Pre‐clinical studies suggested that autologous adipose‐derived stem cells have benefits for the treatment of ...chronic stroke. This Phase I open‐label study was conducted to demonstrate the safety and efficacy of autologous adipose‐derived stem cells (GXNPC1) in chronic stroke. Three patients with chronic stroke were treated with stereotactic implantation of autologous adipose‐derived stem cells (1 × 108 cells). The primary endpoints of safety evaluation included adverse events, over a 6 months post‐implantation period. The secondary endpoints included improvements in neurological functions. Evolutional change of brain parenchyma was also followed with magnetic resonance imaging (MRI). All three participants improved significantly at 6 months follow‐up. The extent of improvement from pre‐treatment was: National Institutes of Health Stroke Scale improved 5‐15 points, Barthel Index: 25–50 points, Berg balance scale 0–21 points and Fugl‐Meyer modified sensation 3–28 points. All three patients had signal change along the implantation tract on MRI one month after surgery. There is no related safety issue through 6 months observation. Clinical measures of neurological symptoms of these patients with chronic stroke improved at 6 months without adverse effects after implantation of autologous adipose‐derived stem cells (GXNPC1), which might be correlated with post‐implantation changes on brain MRI.
Clinical Trial Registration‐URL: https://clinicaltrials.gov/ct2/show/NCT02813512?term=ADSC&cond=Stroke&cntry=TW&draw=2&rank=1 Unique identifier: NCT02813512.
The synthesis and structural determination of a silver nanocluster Ag20{S2P(OiPr)2}12 (2), which contains an intrinsic chiral metallic core, is produced by reduction of one silver ion from the ...eight‐electron superatom complex Ag21{S2P(OiPr)2}12(PF6) (1) by borohydrides. Single‐crystal X‐ray analysis displays an Ag20 core of pseudo C3 symmetry comprising a silver‐centered Ag13 icosahedron capped by seven silver atoms. Its n‐propyl derivative, Ag20{S2P(OnPr)2}12 (3), can also be prepared by the treatment of silver(I) salts and dithiophosphates in a stoichiometric ratio in the presence of excess amount of BH4−. Crystal structure analyses reveal that the capping silver‐atom positions relative to their icosahedral core are distinctly different in 2 and 3 and generate isomeric, chiral Ag20 cores. Both Ag20 clusters display an emission maximum in the near IR region. DFT calculations are consistent with a description within the superatom model of an 8‐electron Ag135+ core protected by a Ag7{S2P(OR)2}125− external shell. Two additional structural variations are predicted by DFT, showing the potential for isomerism in such Ag20{S2P(OR)2}12 species.
Chiral silver nanocluster: The structure of an intrinsically chiral Ag20 nanocluster was determinded. Containing a silver‐centered icosahedron capped by seven silver atoms, it was rationalized to be an eight‐electron superatom complex. Isomeric Ag20 cores with distinct symmetry were characterized in two derivatives (nPr C1; iPr C3). DFT was used to predict the presence of additional structural variations to show rich isomerism in the Ag20 metallic core.
Currently, the only effective therapy for cirrhosis of the liver is liver transplantation. However, finding a compatible liver is difficult due to the low supply of healthy livers and the ...ever-increasing demand. However, stem-cell therapy may offer a solution for liver cirrhosis; for example, GXHPC1 therapy preparation contains adipose-derived mesenchymal stem cells (AD-MSCs) and was developed for the treatment of liver cirrhosis. In our previous report, animal studies suggested that treatment of a diseased liver via GXHPC1 transplantation can abrogate liver fibrosis and facilitate recovery of liver function. In our current human trial, patients with liver cirrhosis were included. Their adipose tissue was harvested from the subcutaneous fat of the abdominal wall during surgery. AD-MSCs were cultured and suspended at a concentration of 100 million cells in 1 ml of physiological saline (i.e., GXHPC1). This human study passed the Taiwan Food and Drug Administration IND inspection and received Phase I clinical trial permission. The trial was conducted with six patients with liver cirrhosis to demonstrate the safety and efficacy of administering GXHPC1. Intrahepatic injection of GXHPC1 did not cause any safety issues in the analysis of adverse drug reactions and suspected unexpected serious adverse reactions, and showed a tendency for improvement of liver function, METAVIR score, Child–Pugh score, MELD score, and quality of life for patients with liver cirrhosis.
Stable lithium–sulfur batteries (LSBs) have promise to shape a new generation of stable energy-storage devices. Although the energy densities of LSBs (up to 2500 W h kg−1) are higher than those of ...conventional Li-ion batteries (LIBs), lithium polysulfides (LiPSs) shuttling remains a pressing issue that leads to irreversible loss of active materials, degraded capacity, and eroded durability of LSBs. To tackle this issue, in this study we modified commercial polypropylene (PP) or pristine separators by laminating them with a layer of crumpled MoS2 (c-MoS2) nanosheets; the resulting assembly is referred to herein as MC-separator. We synthesized the c-MoS2 nanosheets using a special electrohydrodynamic process and laminated them onto the PP separator through simple vacuum filtration. The synthesized c-MoS2 nanosheets featured a metallic 1T-phase enriched with strained sulfur vacancies and a high surface area, providing additional redox reaction sites for LiPSs during battery operations. The c-MoS2 thin film could adsorb the LiPSs while providing additional reaction sites to reutilize these LiPSs, ultimately enhancing the specific capacity of the battery. When operated at a rate of 0.5C, a cell comprising a sulfur-expanded graphite cathode, the MC separator, and a Li anode provided a high specific capacity (1242 mA h g−1) with approximately 96% coulombic efficiency over 500 cycles. In contrast, a cell prepared with a PP separator, when operated at 0.5C, provided an initial capacity of only 746 mA h g−1 and could be run for only 296 cycles. The high capacity and good cycling stability of our new cell indicate that the MC separator could suppress the LiPSs shuttle effect, allowing better utilization of the active materials even at high C rates.
Sciatic nerve injuries, not uncommon in trauma with a limited degree of functional recovery, are considered a persistent clinical, social, and economic problem worldwide. Accumulating evidence ...suggests that stem cells can promote the tissue regeneration through various mechanisms. The aim of the present study was to investigate the role of adipose tissue–derived stem cells (ADSCs) and combine with platelet-rich fibrin releasate (PRFr) in the regeneration of sciatic nerve injury in rats. Twenty-four Sprague-Dawley rats were randomly assigned to four groups, a blade was used to transect the left hindlimb sciatic nerve, and silicon tubes containing one of the following (by injection) were used to bridge the nerve proximal and distal ends (10-mm gap): group 1: untreated controls; group 2: PRFr alone; group 3: ADSCs alone; group 4: PRFr + ADSCs-treated. Walking function was assessed in horizontal rung ladder apparatus to compare the demands of the tasks and test sensitivity at 1-mo interval for a total of 3 mo. The gross inspection and histological examination was performed at 3 mo post transplantation. Overall, PRFr + ADSCs-treated performed better compared with PRFr or ADSCs injections alone. Significant group differences of neurological function were observed in ladder rung walking tests in all treated groups compared to that of untreated controls (P < 0.05). This injection approach may provide a successfully employed technique to target sciatic nerve defects in vivo, and the combined strategy of ADSCs with PRFr appears to have a superior effect on nerve repair.
Stem cells can modify macrophage phenotypes; however, the mechanisms remain unclear. We investigated whether n-butylidenephthalide (BP) primed adipose-derived stem cells (ADSCs) attenuated cardiac ...fibrosis via regulating macrophage phenotype by a PI3K/STAT3-dependent pathway in postinfarcted rats. Male Wistar rats after coronary ligation were allocated to receive either intramyocardial injection of vehicle, ADSCs (1 × 106 cells), BP-preconditioned ADSCs, (BP + lithium)-preconditioned ADSCs, (BP + LY294002)-preconditioned ADSCs, and (BP + S3I-201)-preconditioned ADSCs. ADSCs were primed for 16 h before implantation. BP-pretreated ADSCs increased the cell viability compared with naive ADSCs in the in vitro experiments. Infarct sizes were similar among the infarcted groups at the acute and chronic stages of infarction. At day 3 after infarction, post-infarction was associated with increased M1 macrophage infiltration, which was inhibited by administering naive ADSCs. Compared with naive ADSCs, BP-preconditioned ADSCs provided a significant increase of Akt and STAT3 phosphorylation, STAT3 activity, STAT3 nuclear translocation, myocardial IL-10 levels, and the percentage of M2 macrophage infiltration. The effects of BP on M2 polarization were reversed by LY294002 or S3I-201. Furthermore, the phosphorylation of both Akt and STAT3 was abolished by LY294002, whereas Akt phosphorylation was not affected following the inhibition of STAT3. The addition of lithium did not have additional effects compared with BP alone. After 4 weeks of implantation, ADSCs remained in the myocardium, and reduced fibrosis and improved cardiac function. BP-preconditioned ADSCs provided superior cardioprotection, greater ADSC engraftment, and antifibrotic effects compared with naive ADSCs. These results suggest that BP-pretreated ADSCs polarize macrophages into M2 cells more efficiently than naive ADSCs via the PI3K/STAT3 pathway.
Cognitive impairment is a serious side effect of post-myocardial infarction (MI) course. We have recently demonstrated that human adipose-derived stem cells (hADSCs) ameliorated myocardial injury ...after MI by attenuating reactive oxygen species (ROS) levels. Here, we studied whether the beneficial effects of intramyocardial hADSC transplantation can extend to the brain and how they may attenuate cognitive dysfunction via modulating ROS after MI. After coronary ligation, male Wistar rats were randomized via an intramyocardial route to receive either vehicle, hADSC transplantation (1 × 10
6
cells), or the combination of hADSCs and 3-Morpholinosydnonimine (SIN-1, a peroxynitrite donor). Whether hADSCs migrated into the hippocampus was assessed by using human-specific primers in qPCR reactions. Passive avoidance test was used to assess cognitive performance. Postinfarction was associated with increased oxidative stress in the myocardium, circulation, and hippocampus. This was coupled with decreased numbers of dendritic spines as well as a significant downregulation of synaptic plasticity consisting of synaptophysin and PSD95. Step-through latency during passive avoidance test was impaired in vehicle-treated rats after MI. Intramyocardial hADSC injection exerted therapeutic benefits in improving cardiac function and cognitive impairment. None of hADSCs was detected in rat’s hippocampus at the 3rd day after intramyocardial injection. The beneficial effects of hADSCs on MI-induced histological and cognitive changes were abolished after adding SIN-1. MI-induced ROS attacked the hippocampus to induce neurodegeneration, resulting in cognitive deficit. The remotely intramyocardial administration of hADSCs has the capacity of improved synaptic neuroplasticity in the hippocampus mediated by ROS, not the cell engraftment, after MI.
Key messages
Human adipose-derived stem cells (hADSCs) ameliorated injury after myocardial infarction by attenuating reactive oxygen species (ROS) levels.
Intramyocardial administration of hADSCs remotely exerted therapeutic benefits in improving cognitive impairment after myocardial infarction.
The improved synaptic neuroplasticity in the hippocampus was mediated by hADSC-inhibiting ROS, not by the stem cell engraftment.
Nasopharyngeal carcinoma (NPC) is a multifactorial malignancy closely associated with genetic factors and Epstein-Barr virus infection. To identify the common genetic variants linked to NPC ...susceptibility, we conducted a genome-wide association study (GWAS) in 277 NPC patients and 285 healthy controls within the Taiwanese population, analyzing 480,365 single-nucleotide polymorphisms (SNPs). Twelve statistically significant SNPs were identified and mapped to chromosome 6p21.3. Associations were replicated in two independent sets of case-control samples. Two of the most significant SNPs (rs2517713 and rs2975042; pcombined = 3.9 × 10−20 and 1.6 × 10−19, respectively) were located in the HLA-A gene. Moreover, we detected significant associations between NPC and two genes: specifically, gamma aminobutyric acid b receptor 1 (GABBR1) (rs29232; pcombined = 8.97 × 10−17) and HLA-F (rs3129055 and rs9258122; pcombined = 7.36 × 10−11 and 3.33 × 10−10, respectively). Notably, the association of rs29232 remained significant (residual p < 5 × 10−4) after adjustment for age, gender, and HLA-related SNPs. Furthermore, higher GABAB receptor 1 expression levels can be found in the tumor cells in comparison to the adjacent epithelial cells (p < 0.001) in NPC biopsies, implying a biological role of GABBR1 in NPC carcinogenesis. To our knowledge, it is the first GWAS report of NPC showing that multiple loci (HLA-A, HLA-F, and GABBR1) within chromosome 6p21.3 are associated with NPC. Although some of these relationships may be attributed to linkage disequilibrium between the loci, the findings clearly provide a fresh direction for the study of NPC development.
Five heterometallic pentanuclear metal strings were prepared by stepwise synthesis from two to three and four kinds of metals aligned in one chain. In particular, NiPtCo2Pd(tpda)4Cl2 (5) possesses ...four different metals, and the SQUID measurement shows that Ni2+ is the only magnetically active center. Besides, the shortest Co(ii)–Co(ii) single bond (2.105(9) Å), so far, is reported.
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