A serotonergic axon-cilium synapse drives nuclear signaling to alter chromatin accessibility.

Chemical synapses between axons and dendrites mediate neuronal intercellular communication. Here, we describe a synapse between axons and primary cilia: the axo-ciliary synapse. Using enhanced focused ion beam-scanning electron microscopy on samples with optimally preserved ultrastructure, we discovered synapses between brainstem serotonergic axons and the primary cilia of hippocampal CA1 pyramidal neurons. Functionally, these cilia are enriched in a ciliary-restricted serotonin receptor, the 5-hydroxytryptamine receptor 6 (5-HTR6). Using a cilia-targeted serotonin sensor, we show that opto- and chemogenetic stimulation of serotonergic axons releases serotonin onto cilia. Ciliary 5-HTR6 stimulation activates a non-canonical Gαq/11-RhoA pathway, which modulates nuclear actin and increases histone acetylation and chromatin accessibility. Ablation of this pathway reduces chromatin accessibility in CA1 pyramidal neurons. As a signaling apparatus with proximity to the nucleus, axo-ciliary synapses short circuit neurotransmission to alter the postsynaptic neuron's epigenetic state.

ER-to-Golgi protein delivery through an interwoven, tubular network extending from ER.

Cellular versatility depends on accurate trafficking of diverse proteins to their organellar destinations. For the secretory pathway (followed by approximately 30% of all proteins), the physical nature of the vessel conducting the first portage (endoplasmic reticulum [ER] to Golgi apparatus) is unclear. We provide a dynamic 3D view of early secretory compartments in mammalian cells with isotropic resolution and precise protein localization using whole-cell, focused ion beam scanning electron microscopy with cryo-structured illumination microscopy and live-cell synchronized cargo release approaches. Rather than vesicles alone, the ER spawns an elaborate, interwoven tubular network of contiguous lipid bilayers (ER exit site) for protein export. This receptacle is capable of extending microns along microtubules while still connected to the ER by a thin neck. COPII localizes to this neck region and dynamically regulates cargo entry from the ER, while COPI acts more distally, escorting the detached, accelerating tubular entity on its way to joining the Golgi apparatus through microtubule-directed movement.

Neuron-Astrocyte Metabolic Coupling Protects against Activity-Induced Fatty Acid Toxicity.

Metabolic coordination between neurons and astrocytes is critical for the health of the brain. However, neuron-astrocyte coupling of lipid metabolism, particularly in response to neural activity, remains largely uncharacterized. Here, we demonstrate that toxic fatty acids (FAs) produced in hyperactive neurons are transferred to astrocytic lipid droplets by ApoE-positive lipid particles. Astrocytes consume the FAs stored in lipid droplets via mitochondrial ß-oxidation in response to neuronal activity and turn on a detoxification gene expression program. Our findings reveal that FA metabolism is coupled in neurons and astrocytes to protect neurons from FA toxicity during periods of enhanced activity. This coordinated mechanism for metabolizing FAs could underlie both homeostasis and a variety of disease states of the brain.

Motion of VAPB molecules reveals ER-mitochondria contact site subdomains.

To coordinate cellular physiology, eukaryotic cells rely on the rapid exchange of molecules at specialized organelle-organelle contact sites1,2. Endoplasmic reticulum-mitochondrial contact sites (ERMCSs) are particularly vital communication hubs, playing key roles in the exchange of signalling molecules, lipids and metabolites3,4. ERMCSs are maintained by interactions between complementary tethering molecules on the surface of each organelle5,6. However, due to the extreme sensitivity of these membrane interfaces to experimental perturbation7,8, a clear understanding of their nanoscale organization and regulation is still lacking. Here we combine three-dimensional electron microscopy with high-speed molecular tracking of a model organelle tether, Vesicle-associated membrane protein (VAMP)-associated protein B (VAPB), to map the structure and diffusion landscape of ERMCSs. We uncovered dynamic subdomains within VAPB contact sites that correlate with ER membrane curvature and undergo rapid remodelling. We show that VAPB molecules enter and leave ERMCSs within seconds, despite the contact site itself remaining stable over much longer time scales. This metastability allows ERMCSs to remodel with changes in the physiological environment to accommodate metabolic needs of the cell. An amyotrophic lateral sclerosis-associated mutation in VAPB perturbs these subdomains, likely impairing their remodelling capacity and resulting in impaired interorganelle communication. These results establish high-speed single-molecule imaging as a new tool for mapping the structure of contact site interfaces and reveal that the diffusion landscape of VAPB at contact sites is a crucial component of ERMCS homeostasis.

Regulation of liver subcellular architecture controls metabolic homeostasis.

Cells display complex intracellular organization by compartmentalization of metabolic processes into organelles, yet the resolution of these structures in the native tissue context and their functional consequences are not well understood. Here we resolved the three-dimensional structural organization of organelles in large (more than 2.8 × 105 µm3) volumes of intact liver tissue (15 partial or full hepatocytes per condition) at high resolution (8 nm isotropic pixel size) using enhanced focused ion beam scanning electron microscopy1,2 imaging followed by deep-learning-based automated image segmentation and 3D reconstruction. We also performed a comparative analysis of subcellular structures in liver tissue of lean and obese mice and found substantial alterations, particularly in hepatic endoplasmic reticulum (ER), which undergoes massive structural reorganization characterized by marked disorganization of stacks of ER sheets3 and predominance of ER tubules. Finally, we demonstrated the functional importance of these structural changes by monitoring the effects of experimental recovery of the subcellular organization on cellular and systemic metabolism. We conclude that the hepatic subcellular organization of the ER architecture are highly dynamic, integrated with the metabolic state and critical for adaptive homeostasis and tissue health.

A 0.6 Mpc H I structure associated with Stephan's Quintet.

Stephan's Quintet (SQ, co-moving radial distance = 85 ± 6 Mpc, taken from the NASA/IPAC Extragalactic Database (NED)1) is unique among compact groups of galaxies2-12. Observations have previously shown that interactions between multiple members, including a high-speed intruder galaxy currently colliding into the intragroup medium, have probably generated tidal debris in the form of multiple gaseous and stellar filaments6,8,13, the formation of tidal dwarfs7,14,15 and intragroup-medium starbursts16, as well as widespread intergalactic shocked gas5,10,11,17. The details and timing of the interactions and collisions remain poorly understood because of their multiple nature18,19. Here we report atomic hydrogen (H I) observations in the vicinity of SQ with a smoothed sensitivity of 1σ = 4.2 × 1016 cm-2 per channel (velocity bin-width Δv = 20 km s-1; angular resolution = 4'), which are about two orders of magnitude deeper than previous observations8,13,20,21. The data show a large H I structure (with linear scale of around 0.6 Mpc) encompassing an extended source of size approximately 0.4 Mpc associated with the debris field and a curved diffuse feature of length around 0.5 Mpc attached to the south edge of the extended source. The diffuse feature was probably produced by tidal interactions in early stages of the formation of SQ (>1 Gyr ago), although it is not clear how the low-density H I gas (NH i ≲ 1018 cm-2) can survive the ionization by the intergalactic ultraviolet background on such a long time scale. Our observations require a rethinking of properties of gas in outer parts of galaxy groups and demand complex modelling of different phases of the intragroup medium in simulations of group formation.

Whole-cell organelle segmentation in volume electron microscopy.

Cells contain hundreds of organelles and macromolecular assemblies. Obtaining a complete understanding of their intricate organization requires the nanometre-level, three-dimensional reconstruction of whole cells, which is only feasible with robust and scalable automatic methods. Here, to support the development of such methods, we annotated up to 35 different cellular organelle classes-ranging from endoplasmic reticulum to microtubules to ribosomes-in diverse sample volumes from multiple cell types imaged at a near-isotropic resolution of 4 nm per voxel with focused ion beam scanning electron microscopy (FIB-SEM)1. We trained deep learning architectures to segment these structures in 4 nm and 8 nm per voxel FIB-SEM volumes, validated their performance and showed that automatic reconstructions can be used to directly quantify previously inaccessible metrics including spatial interactions between cellular components. We also show that such reconstructions can be used to automatically register light and electron microscopy images for correlative studies. We have created an open data and open-source web repository, 'OpenOrganelle', to share the data, computer code and trained models, which will enable scientists everywhere to query and further improve automatic reconstruction of these datasets.

An open-access volume electron microscopy atlas of whole cells and tissues.

Understanding cellular architecture is essential for understanding biology. Electron microscopy (EM) uniquely visualizes cellular structures with nanometre resolution. However, traditional methods, such as thin-section EM or EM tomography, have limitations in that they visualize only a single slice or a relatively small volume of the cell, respectively. Focused ion beam-scanning electron microscopy (FIB-SEM) has demonstrated the ability to image small volumes of cellular samples with 4-nm isotropic voxels1. Owing to advances in the precision and stability of FIB milling, together with enhanced signal detection and faster SEM scanning, we have increased the volume that can be imaged with 4-nm voxels by two orders of magnitude. Here we present a volume EM atlas at such resolution comprising ten three-dimensional datasets for whole cells and tissues, including cancer cells, immune cells, mouse pancreatic islets and Drosophila neural tissues. These open access data (via OpenOrganelle2) represent the foundation of a field of high-resolution whole-cell volume EM and subsequent analyses, and we invite researchers to explore this atlas and pose questions.

Transverse endoplasmic reticulum expansion in hereditary spastic paraplegia corticospinal axons.

Hereditary spastic paraplegias (HSPs) comprise a large group of inherited neurologic disorders affecting the longest corticospinal axons (SPG1-86 plus others), with shared manifestations of lower extremity spasticity and gait impairment. Common autosomal dominant HSPs are caused by mutations in genes encoding the microtubule-severing ATPase spastin (SPAST; SPG4), the membrane-bound GTPase atlastin-1 (ATL1; SPG3A) and the reticulon-like, microtubule-binding protein REEP1 (REEP1; SPG31). These proteins bind one another and function in shaping the tubular endoplasmic reticulum (ER) network. Typically, mouse models of HSPs have mild, later onset phenotypes, possibly reflecting far shorter lengths of their corticospinal axons relative to humans. Here, we have generated a robust, double mutant mouse model of HSP in which atlastin-1 is genetically modified with a K80A knock-in (KI) missense change that abolishes its GTPase activity, whereas its binding partner Reep1 is knocked out. Atl1KI/KI/Reep1-/- mice exhibit early onset and rapidly progressive declines in several motor function tests. Also, ER in mutant corticospinal axons dramatically expands transversely and periodically in a mutation dosage-dependent manner to create a ladder-like appearance, on the basis of reconstructions of focused ion beam-scanning electron microscopy datasets using machine learning-based auto-segmentation. In lockstep with changes in ER morphology, axonal mitochondria are fragmented and proportions of hypophosphorylated neurofilament H and M subunits are dramatically increased in Atl1KI/KI/Reep1-/- spinal cord. Co-occurrence of these findings links ER morphology changes to alterations in mitochondrial morphology and cytoskeletal organization. Atl1KI/KI/Reep1-/- mice represent an early onset rodent HSP model with robust behavioral and cellular readouts for testing novel therapies.

Introduction and validation of the open symptom framework: a public domain modular framework for patient-reported measurement of symptoms related to cancer and its treatment.

PURPOSE: We provide an initial description and validation of some public domain patient-reported outcome (PRO) items to assess cancer symptom burden to address immediate barriers to symptom assessment use in clinical practice and facilitate future research. METHODS: We created the Open Symptom Framework (OSF), a flexible tool for clinical cancer-related symptom assessment. The items comprise six components: recall period, concept, symptom, qualifier(s), a definition, and a 5-point Likert-type response. We recruited patients receiving cancer therapy in the United States and United Kingdom. We assessed external construct validity by comparing OSF scores to the PRO-CTCAE measure and assessed reliability, scalability, dimensionality, and item ordering within a non-parametric item response theory framework. We tested differential item functioning for country, age, gender, and level of education. RESULTS: We developed a framework alongside clinical and psychometric experts and debrieifed with 10 patients. For validation, we recruited 331patients. All items correlated with the PRO-CTCAE equivalents (r = 0.55-0.96, all p < 0.01). Mokken analysis confirmed the scalability and unidimensionality of all symptom scales with multiple items at the scale (Ho = 0.61-0.75) and item level (Hi = 0.60-0.76). Items are interpreted consistently between demographic groups (Crit = 0 for all groups). CONCLUSION: The public domain OSF has excellent psychometric properties including face, content, and criterion validity and can facilitate the development of flexible, robust measurements to fulfil stakeholder need. The OSF was designed specifically to support clinical assessment but will function well for research. Further work is planned to increase the number of symptoms and number of questions per symptom within the framework.

Association between infarct location and haemorrhagic transformation of acute ischaemic stroke after intravenous thrombolysis.

AIM: To evaluate the association between computed tomography (CT)-based imaging variables at the time of admission and haemorrhagic transformation (HT) after intravenous thrombolysis (IVT). MATERIALS AND METHODS: One hundred and eight patients who were treated with IVT for acute ischaemic stroke (AIS) during January 2021 to July 2023 were analysed retrospectively. The infarct location was classified as cortical or subcortical in accordance with the Alberta Stroke Program Early CT Score (ASPECTS) system. Logistic regression and receiver operating characteristic curve analyses were performed to determine the relationship between ischaemic variables and HT. RESULTS: Of the total, 18 (16.7%) patients had HT and seven (6.5%) had symptomatic intracerebral haemorrhage (sICH). Multivariate analysis revealed that cortical ASPECTS was independently associated with HT (odds ratio [OR], 0.197; 95% confidence interval [CI], 0.076-0.511; p=0.001) and cortical ASPECTS was independently associated with sICH (OR, 0.066; 95% CI, 0.009-0.510; p=0.009). To predict HT and sICH, cortical ASPECTS (HT area under the curve [AUC] = 0.881, sICH AUC = 0.971) provided a higher AUC compared with ASPECTS (HT AUC = 0.850, sICH AUC = 0.918). CONCLUSION: Cortical ASPECTS seen on CT at the time of admission is associated with HT and sICH after IVT.

Transarterial chemoembolization combined with microwave ablation versus repeated resection for recurrent small hepatocellular carcinoma after resection: What is the better treatment?

PURPOSE: This study aimed to compare the effectiveness of transcatheter arterial chemoembolization combined with microwave ablation (TACE-MWA) versus repeated hepatic resection (RHR) in patients with recurrent small hepatocellular carcinoma (sHCC) following primary resection. MATERIALS AND METHODS: A total of 59 patients diagnosed with recurrent sHCC (≤3 cm) and treated with either TACE-MWA or RHR were recruited from two centers between June 2015 and October 2021. Patients were matched using propensity scores at a 1:1 ratio. Disease-free survival (DFS), overall survival (OS), and complications were assessed and compared between the two treatment groups. RESULTS: After propensity score matching, 38 patients were included, with 19 in each group. Prior to matching, the 1-, 3-, and 5-year DFS rates for the TACE-MWA group were 68.1%, 46.6%, and 23.3%, respectively, and for the RHR group, they were 84.6%, 47.3%, and 47.3%, respectively. The corresponding 1-, 3-, and 5-year OS rates for TACE-MWA were 100.0%, 83.7%, and 47.8%, while for RHR, they were 100.0%, 95.0%, and 45.2%. After matching, the 1-, 3-, and 5-year DFS rates were 78.0%, 48.3%, and 24.1% for TACE-MWA, and 77.5%, 38.7%, and 38.7% for RHR. The 1-, 3-, and 5-year OS rates for TACE-MWA were 100.0%, 88.9%, and 54.9%, and for RHR, they were 100.0%, 93.3%, and 44.4%. Statistical analysis showed no significant differences in DFS rates (P=0.834 before matching, P=0.490 after matching) or OS rates (P=0.825 before matching, P=0.625 after matching) between the two groups. CONCLUSIONS: TACE-MWA demonstrates comparable effectiveness to RHR in managing recurrent sHCC.

[Application of whole exome sequencing technology in the diagnosis of hereditary eye diseases].

Objective: To evaluate the application of whole exome sequencing (WES) in the diagnosis of hereditary eye diseases. Methods: A total of 24 patients who came to the Obstetrics and Gynecology Hospital of Fudan University for reproductive genetic counseling from December 2020 to December 2023 with the main complaint of congenital eye disorders were included in this study. All cases had no known infections or exposure to known teratogenic drugs, karyotype and chromosome microarray analysis (CMA) abnormalities. Genomic DNA was extracted from the peripheral blood of the probands and their family members and tested for WES. Among them, three individual WES and 21 Trio WES were performed. Potential pathogenic sites were screened and analyzed by Sanger sequencing. For RPGRIP1:c.1611+26G>A site, minigene vector was constructed and RT-qPCR was performed to detect the effect of mRNA splicing. Results: A total of 24 families were collected in this study, of which 20 yielded positive results, achieving a diagnosis rate of 83.3% (20/24). The results involved 21 genes and identified 30 distinct variants, 19 of which were new variants reported. Prenatal diagnostic analysis of family 3 revealed that the fetus carried a c.6970G>T heterozygous nonsense mutation in the PRPF8 gene. The results of RT-PCR with the minigene vector at the non-classical splice site in family 24 indicated that the transcription product of the mutant plasmid was partially retained 104 bp in intron 12, resulting in a p.Glu538Valfs*12 alteration of the protein. Conclusions: The high detection rate of WES in the diagnosis of hereditary eye diseases further supports the advantages of its application as an important molecular detection tool for determining the etiology of hereditary eye diseases.

[Predictive value of whole brain perfusion on admission for shunt-dependent hydrocephalus fllowing aneurysmal subarachnoid hemorrhage].

Objective: To explore the value of predicting shunt-dependent hydrocephalus (SDHC) in patients with aneurysmal subarachnoid hemorrhage (aSAH) based on whole brain CT perfusion(CTP) and clinical data within 24 hours at admission. Methods: The clinical and imaging data of aSAH patients who received interventional embolization in our hospital were retrospectively collected from March 2018 to August 2022. All patients underwent one-stop whole brain CT examination within 24 hours after symptom onset, and the qualitative and quantitative CTP parameters were obtained after post-processing. Follow-up was conducted once every 2 months by consulting electronic medical records or by telephone for 6 months. According to whether SDHC occurred or not, the patients were divided into SDHC group and non-SDHC group. The differences between the two groups were compared. Logistic regression model was used to analyze and determine the predictive factors of SDHC, and the SDHC predictive model was established. The effectiveness of the predictive model was evaluated by drawing the receiver operating characteristic (ROC) curve of the subjects. Results: A total of 414 patients were included, including 132 males and 282 females, aged (59±11) years. 17.6%(73/414) patients had SDHC. There were significant differences in the occurrence of acute hydrocephalus, the World Neurosurgical League Scale (WFNS), the Hunt-Hess scale, the modified Fisher score (mFS), and the qualitative and quantitative parameters of CTP between the two groups (both P<0.001). Multivariate logistic regression analysis showed that acute hydrocephalus (OR=8.621, 95%CI: 4.237-17.542),old age (OR=1.107, 95%CI: 1.068-1.148), high mFS and high Hunt-Hess classification (OR=3.740, 95%CI: 1.352-10.342) were the risk factors of SDHC in aSAH patients, and high mean cerebral blood flow (mCBF) (OR=0.931, 95%CI: 0.885-0.980) was a protective factor of SDHC.The area under ROC curve (AUC) of the prediction model constructed by these five variables was 0.923(95%CI: 0.89-0.95), with 84.5% sensitivity and 87.7% specificity. Conclusion: The mCBF and acute hydrocephalus, age, mFS and Hunt-Hess classification within 24 hours at admission can be used to predict SDHC for aSAH patients.

[Topological properties of white matter network in first untreated children and adolescents with obsessive-compulsive disorder].

Objective: To investigate the topological properties of the white matter network in the drug-naive first-episode children and adolescent with obsessive-compulsive disorder (OCD). Methods: This study was a case-control study. First-episode OCD childhren and adolescents(OCD group) who were treated in the outpatient or inpatient department of the Second Affiliated Hospital of Xinxiang Medical University from July 2018 to October 2023 were collected as the research subjects. Healthy controls (control group)matched by gender, age and education level were used as controls. Deterministic tractography technique was used to construct the whole brain white matter structural network, and graph theory analysis method was used to analyze the topological attributes of the whole brain white matter structure network in OCD children and adolescents. A network-based statistical method was used to examine the inter-group differences in the functional connectivity strength of the whole brain network. Results: Finally, 31 cases were included in the obsessive-compulsive disorder group, including 22 males and 9 females, with an age of (13.5±1.6) years; There were 34 cases in the control group, including 22 males and 12 females, with an age of (12.7±1.4) years. The global efficiency and local efficiency of the OCD group (0.62±0.03, 0.70±0.07) were significantly higher than those of the control group (0.50±0.06, 0.54±0.21) [both P<0.01, false discovery rate(FDR)correction]; while the characteristic path length (1.77±0.08) was significantly smaller than that of the control group (2.10±0.23) (P<0.01, FDR correction).The centrality comparison of nodal betweenness centrality showed that in the OCD group, the connections were enhanced in the left lateral orbitofrontal gyrus, right dorsal agranular insula, left dorsal granular insula, right granular insula, right posterior central gyrus main area of parietal lobe, left ventral granular insula, granular insula, left ventral granulosa, left granular insula, and left dorsal agranular insula [all P<0.001, family wise error (FWE) correction], while the connection of right thalamic was weakened (P<0.001, FWE correction), There were sub-networks characterized by significantly enhanced connection strength of relevant nodes in subcortical, visual network, and default mode network (P<0.05, permutation test 5 000 times). Conclusions: The topological properties of the brain's functional network in children and adolescents with OCD exhibit abnormalities, indicating an immature state of brain functional connectivity.

[Differentiation of temporal lobe epilepsy and temporal plus epilepsy using radiomics nomogram based on MPRAGE images].

A total of 82 patients with temporal lobe epilepsy (TLE) and temporal plus epilepsy (TPE)admitted in Xuanwu Hospital from January 1, 2019, to January 1, 2021 were restrospectively analyzed, including 41 males and 41 females, aged 2 to 52 (24±10) years. The patients were randomly divided into the training set (58 cases) and test set (24 cases) by Python. FreeSurfer software was used to segment the cortex of the affected hemisphere, defining 33 regions of interest (ROIs), and radiomics features were extracted by Python. After selecting features using the filter-based feature selection method, a radiomics model was constructed with a logistic regression classifier, and radiomics scores were calculated. Combining clinical characteristics with radiomics scores, a nomogram model was constructed using R software, the predictive accuracy of the model was assessed with the concordance index (C-index), and the model's goodness-of-fit was tested with the Hosmer-Lemeshow method. The results showed statistically significant differences between TLE and TPE patients in disease duration, intracranial electrode implantation, and hippocampal sclerosis (both P<0.05). The accuracy of the radiomics model in the training set and the test set was 91.4% and 87.5%, respectively. The nomogram model uses C-index to predict accuracy. Hosmer-Lemeshow method was used to test the goodness of fit, with AUCs of 0.95 (95%CI: 0.853-0.991) in the training set and 0.84 (95%CI: 0.676-0.999) in the test set. The study indicates that the radiomics nomogram model based on MPRAGE sequences can effectively differentiate TLE from TPE, providing reference for the development of personalized treatment plans in clinical practice.

[Therapeutic efficacy of transoral robotic surgery with the da Vinci robot system for the treatment of oropharyngeal squamous cell carcinoma].

Objective: To evaluate the clinical efficacy of transoral robotic surgery (TORS) with the da Vinci robot system in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Methods: A mixed cohort study was conducted to collect and analyze the clinical data of OPSCC patients who underwent TORS at the Eye & ENT Hospital, Fudan University between July 2020 and February 2023 (TORS group). OPSCC patients who underwent conventional surgery between January 2016 and September 2020 were included as the control group. The baseline information, incidence of complications and follow-up data were compared between the two groups. Results: A total of 166 patients were included, with 102 cases (81 males and 21 females) in the TORS group [mean age: (59.1±9.8) years] and 64 cases (54 males and 10 females) in the control group [ mean age: (57.6±9.7) years]. Compared with the control group, the TORS group had lower postoperative bleeding rate [2.9% (3/102) vs 10.9% (7/64), P=0.035] and infection rate [1.0% (1/102) vs 18.8% (12/64), P<0.001]. No statistically significant differences were observed in tracheotomy rate [46.1% (47/102) vs 59.4% (38/64), P=0.070] and median length of hospital stay [8 (7, 10) d vs 10 (4, 12) d, P=0.088]. After propensity score matching, compared with the control group, the TORS group had lower postoperative infection rate [0 (0/31) vs 19.4% (6/31), P=0.032] and median length of hospital stay [7 (7, 10) d vs 10 (8, 12) d, P=0.031]. No statistically significant differences were found in postoperative bleeding rate [3.2% (1/31) vs 6.5% (2/31), P=1.000] and tracheotomy rate [22.6% (7/31) vs 45.2% (14/31), P=0.060] between the two groups. Moreover, 1-and 2-year disease-free survival rates were 96.3% and 94.6% in the TORS group, and 90.6% and 84.3% in the control group, respectively (P=0.233). The 1-and 2-year cancer-specific survival rates were both 100% in the TORS group, and 96.9% and 93.8% in the control group, respectively (P=0.539). Conclusion: TORS for OPSCC is associated with high clinical safety and favorable oncological outcomes.

[Clinicopathological features of gastric alpha-fetoprotein-producing adenocarcinoma with SWI/SNF complex deletion].

Objective: To investigate the clinicopathological features and treatment of gastric alpha-fetoprotein (AFP)-producing adenocarcinoma with SWI/SNF complex deletion. Methods: Four cases of gastric AFP-producing adenocarcinoma with SWI/SNF complex deletion diagnosed in Zhongshan Hospital of Fudan University from January 2021 to December 2022 were collected, and their histomorphological characteristics, immunohistochemical (IHC), in situ hybridization of Epstein-Barr virus-encoded RNA (EBER), next-generation sequencing results, clinicopathological features and treatment were summarized, and literature review was conducted. Results: Among the 4 patients, there were three males and one female. They presented with abdominal pain, belching and melena. Serum AFP was significantly elevated in three patients, and endoscopy showed ulcerative lesions. Microscopically, the tumor cells showed mainly diffuse flaky or nest-like growth and typical characteristics of hepatoid adenocarcinoma. In two cases there were adenoid growth, and the tumor cells in these areas possessed clear cytoplasm, suggesting enteroblastic differentiation. The tumor cell nuclei were pleomorphic with large nucleoli and brisk mitoses. The IHC results showed that the tumor cells expressed AFP, GPC3 and SALL4, and there was retained expression of broad-spectrum keratin (CKpan) and E-cadherin. IHC detection of SWI/SNF complex subunits, namely INI1 (SMARCB1), BRG1 (SMARCA4), BRM (SMARCA2), ARID1A protein was performed. In all four cases the hepatoid adenocarcinoma region and enteroblastic differentiation region showed SMARCA2 deletion, and one case with enteroblastic differentiation also showed ARID1A deletion. SMARCB1 and SMARCA4 deletions were not seen. All the four cases were diffusely positive for p53 protein, and the Ki-67 proliferation index was 80%-90%. There were no mismatch repair deletion detected; one cases showed HER2 was strongly positive (3+), and EBER was negative. None of the four cases had mutations in the SWI/SNF complex-related subunits detected by next-generation sequencing. Among the four patients, two underwent palliative surgery due to distant metastasis at the time of surgery, two underwent radical resection. Postoperative adjuvant chemotherapy was given to three patients. Conclusions: AFP-producing adenocarcinoma is a rare subtype of gastric cancer, which can be combined with SWI/SNF complex deletion, and the pathomorphological manifestations are different from the classical SWI/SNF complex deletion of undifferentiated carcinoma with rhabdoid phenotype.

[Reappraisals of biological behaviors of PDGFRA mutant gastrointestinal stromal tumor].

Objective: To investigate the biological behavior spectrum of platelet-derived growth factor alpha receptor (PDGFRA)-mutant gastrointestinal stromal tumor (GIST), and to compare the clinical values of the Zhongshan method of benign and malignant evaluation with the modified National Institutes of Health (NIH) risk stratification. Methods: A total of 119 cases of GIST with PDGFRA mutation who underwent surgical resection at Zhongshan Hospital, Fudan University from 2009 to 2020 were collected. The clinicopathological data, follow-up records, and subsequent treatment were reviewed and analyzed statistically. Results: There were 79 males and 40 females. The patients ranged in age from 25 to 80 years, with a median age of 60 years. Among them, 115 patients were followed up for 1-154 months, and 13 patients progressed to disease. The 5-year disease-free survival (DFS) and overall survival (OS) were 90.1% and 94.1%, respectively. According to the modified NIH risk stratification, 8 cases, 32 cases, 38 cases, and 35 cases were very-low risk, low risk, intermediate risk, and high risk, and 5-year DFS were 100.0%, 95.6%, 94.3%, and 80.5%, respectively. There was no significant difference in prognosis among the non-high risk groups, only the difference between high risk and non-high risk groups was significant (P=0.029). However, the 5-year OS was 100.0%, 100.0%, 95.0% and 89.0%, and there was no difference (P=0.221). According to the benign and malignant evaluation Zhongshan method, 43 cases were non-malignant (37.4%), 56 cases were low-grade malignant (48.7%), 9 cases were moderately malignant (7.8%), and 7 cases were highly malignant (6.1%). The 5-year DFS were 100.0%, 91.7%, 77.8%, 38.1%, and the difference was significant (P<0.001). The 5-year OS were 100.0%, 97.5%, 77.8%, 66.7%, the difference was significant (P<0.001). Conclusions: GIST with PDGFRA gene mutation shows a broad range of biological behavior, ranging from benign to highly malignant. According to the Zhongshan method, non-malignant and low-grade malignant tumors are common, the prognosis after surgery is good, while the fewer medium-high malignant tumors showed poor prognosis after surgical resection. The overall biological behavior of this type of GIST is relatively inert, which is due to the low proportion of medium-high malignant GIST. The modified NIH risk stratification may not be effective in risk stratification for PDGFRA mutant GIST.

Gas cluster ion beam SEM for imaging of large tissue samples with 10 nm isotropic resolution.

We demonstrate gas cluster ion beam scanning electron microscopy (SEM), in which wide-area ion milling is performed on a series of thick tissue sections. This three-dimensional electron microscopy technique acquires datasets with <10 nm isotropic resolution of each section, and these can then be stitched together to span the sectioned volume. Incorporating gas cluster ion beam SEM into existing single-beam and multibeam SEM workflows should be straightforward, increasing reliability while improving z resolution by a factor of three or more.