Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures.

JOURNAL/nrgr/04.03/01300535-202501000-00034/figure1/v/2024-05-14T021156Z/r/image-tiff Certain amino acids changes in the human Na+/K+-ATPase pump, ATPase Na+/K+ transporting subunit alpha 1 (ATP1A1), cause Charcot-Marie-Tooth disease type 2 (CMT2) disease and refractory seizures. To develop in vivo models to study the role of Na+/K+-ATPase in these diseases, we modified the Drosophila gene homolog, Atpα, to mimic the human ATP1A1 gene mutations that cause CMT2. Mutations located within the helical linker region of human ATP1A1 (I592T, A597T, P600T, and D601F) were simultaneously introduced into endogenous DrosophilaAtpα by CRISPR/Cas9-mediated genome editing, generating the AtpαTTTF model. In addition, the same strategy was used to generate the corresponding single point mutations in flies (AtpαI571T, AtpαA576T, AtpαP579T, and AtpαD580F). Moreover, a deletion mutation (Atpαmut) that causes premature termination of translation was generated as a positive control. Of these alleles, we found two that could be maintained as homozygotes (AtpαI571T and AtpαP579T). Three alleles (AtpαA576T, AtpαP579 and AtpαD580F) can form heterozygotes with the Atpαmut allele. We found that the Atpα allele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila. Flies heterozygous for AtpαTTTF mutations have motor performance defects, a reduced lifespan, seizures, and an abnormal neuronal morphology. These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump.

Patterns of Recurrence after Curative Intent Hepatic Resection for Colorectal Liver Metastasis.

BACKGROUND: Improved surgical techniques and more intensive systemic therapy have increased the number of oligometastatic colorectal cancer patients eligible for resection, but a significant percentage of these patients will ultimately recur. Furthermore, distinct recurrence patterns have been associated with different outcomes. METHODS: Data for 195 patients who underwent curative-intent colorectal liver metastasis (CRLM) resection from 2016-2022 at Johns Hopkins Hospital were retrospectively collected. Cox regression univariate and multivariate analysis identified features associated with survival outcomes. Association between risk factors and site of recurrences was conducted via logistic regression with initial recurrences grouped into intrahepatic-only, extrahepatic-only, and concurrent intra- and extrahepatic recurrence. RESULTS: The 1- and 2-year recurrence free survival (RFS) rates were 46% and 22% respectively. The 1- and 2-year overall survival (OS) rates were 95% and 88% respectively. Median OS was 71.7 months. Multivariate analysis identified age <60 years old, N2 nodal status, R1 liver margin, and higher preoperative carcinoembryonic antigen as top prognostic factors for worse RFS. Additionally, patients with left-sided primary tumors had higher risk of intrahepatic-only recurrence while mutant KRAS was associated with higher risk of extrahepatic recurrence with or without liver recurrence. DISCUSSION OR CONCLUSION: These results from a recent cohort of patients treated with current standard of care therapies identifies features associated with elevated recurrence risk and specific recurrence patterns. These insights into CRLM recurrence patterns support a larger prospective study to identify subgroups of patients who may require additional therapies to prevent recurrence.

Effect of tDCS combined with virtual reality for post-stroke cognitive impairment: a randomized controlled trial study protocol.

BACKGROUND: Post-stroke cognitive impairment (PSCI) not only increases patient mortality and disability, but also adversely affects motor function and the ability to perform routine daily activities. Current therapeutic approaches for, PSCI lack specificity, primarily relying on and medication and traditional cognitive therapy supplemented by a limited array of tools. Both transcranial direct current stimulation (tDCS) and virtual reality (VR) training have demonstrated efficacy in improving cognitive performance among PSCI patients. Previous findings across various conditions suggest that implementing a therapeutic protocol combining tDCS and VR (tDCS - VR) may yield superior in isolation. Despite this, to our knowledge, no clinical investigation combining tDCS and VR for PSCI rehabilitation has been conducted. Thus, the purpose of this study is to explore the effects of tDCS - VR on PSCI rehabilitation. METHODS: This 4-week, single-center randomized clinical trial protocol will recruit 200 patients who were randomly assigned to one of four groups: Group A (tDCS + VR), Group B (tDCS + sham VR), Group C (sham tDCS + VR), Group D (sham tDCS + sham VR). All four groups will receive conventional cognitive rehabilitation training. The primary outcome measurement utilizes the Mini-Mental State Examination (MMSE). Secondary outcome measures include the Montreal Cognitive Assessment, Frontal Assessment Battery, Clock Drawing Test, Digital Span Test, Logic Memory Test, and Modified Barthel Index. Additionally, S-YYZ-01 apparatus for diagnosis and treating language disorders assesses subjects' speech function. Pre- and post-four-week intervention assessments are conducted for all outcome measures. Functional near-infrared spectroscopy (fNIRS) is employed to observe changes in oxygenated hemoglobin (HbO), deoxy-hemoglobin (HbR), and total hemoglobin (HbT) in the cerebral cortex. DISCUSSION: Our hypothesis posits that the tDCS - VR therapy, in opposed to individual tDCS or VR interventions, could enhance cognitive function, speech ability and daily living skills in PSCI patients while concurrently augmenting frontal cortical activity. This randomized study aims to provide a robust theoretical foundation supported by scientific evidence for the practical implementation of the tDCS - VR combination as a secure and efficient PSCI rehabilitation approach. TRIAL REGISTRATION: Chictr.org.cn Identifier: ChiCTR2300070580. Registered on 17th April 2023.

Mycorrhizal Symbiosis Increases Plant Phylogenetic Diversity and Regulates Community Assembly in Grasslands.

The intricate mechanisms controlling plant diversity and community composition are cornerstone of ecological understanding. Yet, the role of mycorrhizal symbiosis in influencing community composition has often been underestimated. Here, we use extensive species survey data from 1315 grassland sites in China to elucidate the influence of mycorrhizal symbiosis on plant phylogenetic diversity and community assembly. We show that increasing mycorrhizal symbiotic potential leads to greater phylogenetic dispersion within plant communities. Mycorrhizal species predominantly influence deterministic processes, suggesting a role in niche-based community assembly. Conversely, non-mycorrhizal species exert a stronger influence on stochastic processes, highlighting the importance of random events in shaping community structure. These results underscore the crucial but often hidden role of mycorrhizal symbiosis in driving plant community diversity and assembly. This study provides valuable insights into the mechanisms shaping ecological communities and the way for more informed conservation that acknowledges the complex interplay between symbiosis and community dynamics.

Simulation-Guided Molecular Modeling of Nisin and Lipid II Assembly and Membrane Pore Formation.

The lantibiotic pore-forming peptide nisin is a promising candidate in the fight against multidrug-resistant bacteria due to its unique structure, which allows it to disrupt bacteria in two distinct ways─Lipid II trafficking and transmembrane pore formation. However, exactly how nisin and Lipid II assemble into oligomeric pore structures in the bacterial membrane is not known. Spontaneous peptide assembly into pores is difficult to observe in even the very long-time scale molecular dynamics (MD) simulations. In this study, we adopted an MD-guided modeling approach to investigate the nisin-nisin and nisin-Lipid II associations in the membrane environment. Through extensive microsecond-time scale all-atom MD simulations, we established that nisin monomers dimerize by forming ß-sheets in a POPE:POPG lipid bilayer and oligomerize further to form stable transmembrane channels. We determined that these nisin dimers use Lipid II as a dimer interface to incur enhanced stability. Our results provide a clearer understanding of the self-assembly of nisin monomers within the membrane and insights into the role of Lipid II in the structural integrity of oligomeric structures.

Proposal of a revised 3-tier "2 mm" risk classification model for postoperative pancreatic fistula in robotic pancreatoduodenectomy.

BACKGROUND: The recent International Study Group for Pancreatic Surgery (ISGPS) risk classification for postoperative pancreatic fistula (grade B/C) was developed based on data from open and mixed minimally invasive pancreatoduodenectomy. The ISGPS risk classification model has not been validated specifically for POPF after robotic pancreatoduodenectomy (RPD). METHODS: We calculated the rate of POPF (ISGPS 2016 definition, grade B/C) by analyzing consecutive patients after RPD by surgeons after their learning curves (80 RPDs per surgeon). The validation of the ISGPS 4-tier and the simplified 3-tier risk classification was conducted using the area under the receiver operating curve (AUC). RESULTS: From 2019 to 2023, 187 patients after RPD were included. Neither the ISGPS 4-tier nor the simplified 3-tier classification model showed robust discrimination (AUC: 0.696 and 0.685, respectively). Moreover, both risk classifications failed to differentiate the rates of POPF and major complications among subgroups. Multivariate analysis suggested that soft pancreatic texture and pancreatic duct ≤ 2 mm were independent risk factors for POPF after RPD. After adjusting the duct size's cutoff from 3 to 2 mm, the revised 4-tier "2 mm" classification model showed no significant difference between risk categories B and C (6.7% vs. 9.4%, P = 0.063). The revised 3-tier "2 mm" classification model stratified patients into A (n = 54), B (n = 68), and C (n = 65) groups, with corresponding POPF rates of 0.0%, 8.8%, and 23.1% (P < 0.001), and major complication rates of 5.6, 14.7, and 24.6% (P = 0.014), respectively. Compared to the simplified 3-tier classification model, the revised 3-tier "2 mm" classification model showed improved discrimination (AUC: 0.753 vs. 0.685, P = 0.034) and clinical utility. CONCLUSIONS: The current ISGPS 4-tier and the simplified 3-tier classification models lacked sufficient discrimination in patients after RPD. We propose a revised 3-tier "2 mm" risk classification model for RPD with a robust discrimination, which requires further international validation with prospectively obtained data.

Trans-aconitic acid assimilation system as a widespread bacterial mechanism for environmental adaptation.

The ability of bacteria to use natural carbon sources greatly affects their growth and survival in the environment. Bacteria have evolved versatile abilities to use environmental carbon sources, but their diversity and assimilation pathways remain largely unexplored. Trans-aconitic acid, a geometric isomer of cis-aconitic acid involved in the tricarboxylic acid cycle, has long been considered a natural carbon source metabolizable by bacteria. However, its catabolism and ecological role in linking bacterial interactions with the environments remain unclear. Here, we identify a regulatory system in Bacillus velezensis FZB42 that is capable of sensing and catabolizing trans-aconitic acid. The system consists of a tar operon, an adjacent positive regulatory gene tarR, and a shared promoter. After receiving the trans-aconitic acid signal, the TarR protein interacts directly with the promoter, initiating the expression of the membrane transporter TarB and aconitate isomerase TarA encoded by the operon, which function in importing the trans-aconitic acid and isomerizing it into the central intermediate cis-aconitic acid. Subsequent soil colonization experiments reveal that trans-aconitic acid assimilating ability can give its coding bacteria a growth and competitive advantage. Bioinformatics analyses coupled with bacterial isolation experiments further show that the assimilation system of trans-aconitic acid is widely distributed in the bacterial domain, and its assimilating bacteria also extensively distributed in nature, indicating an important role of trans-aconitic acid metabolism in bacterial carbon acquisition. This work emphasizes the importance of metabolic adaptation to environmental carbon sources for bacterial survival and may provide inspiration for engineering microbes with enhanced environmental competitiveness.

Consensus, debate, and prospective on pancreatic cancer treatments.

Pancreatic cancer remains one of the most aggressive solid tumors. As a systemic disease, despite the improvement of multi-modality treatment strategies, the prognosis of pancreatic cancer was not improved dramatically. For resectable or borderline resectable patients, the surgical strategy centered on improving R0 resection rate is consensus; however, the role of neoadjuvant therapy in resectable patients and the optimal neoadjuvant therapy of chemotherapy with or without radiotherapy in borderline resectable patients were debated. Postoperative adjuvant chemotherapy of gemcitabine/capecitabine or mFOLFIRINOX is recommended regardless of the margin status. Chemotherapy as the first-line treatment strategy for advanced or metastatic patients included FOLFIRINOX, gemcitabine/nab-paclitaxel, or NALIRIFOX regimens whereas 5-FU plus liposomal irinotecan was the only standard of care second-line therapy. Immunotherapy is an innovative therapy although anti-PD-1 antibody is currently the only agent approved by for MSI-H, dMMR, or TMB-high solid tumors, which represent a very small subset of pancreatic cancers. Combination strategies to increase the immunogenicity and to overcome the immunosuppressive tumor microenvironment may sensitize pancreatic cancer to immunotherapy. Targeted therapies represented by PARP and KRAS inhibitors are also under investigation, showing benefits in improving progression-free survival and objective response rate. This review discusses the current treatment modalities and highlights innovative therapies for pancreatic cancer.

Enhancing photosynthetic phosphorus-use efficiency through coordination of leaf phosphorus fractions, allocation and anatomy during soybean domestication.

Soybean domestication has significantly changed key agronomic traits, yet its impact on leaf photosynthetic phosphorus-use efficiency (PPUE) and its underlying traits remain poorly known. Further information on this would be important to increase soybean P-use efficiency. To address this gap, 48 soybean accessions (16 wild relatives, 16 landraces and 16 cultivars) were used to compare leaf anatomical traits, foliar chemical P fractions, P allocation and PPUE under two P levels. The results showed that the cultivars had higher area-based and mass-based photosynthesis rates, PPUE, metabolite P concentration, and its percentage of leaf total P, as well as a greater percentage of lipid P, nucleic acid P and residual P. Conversely, wild relatives tended to have higher leaf P concentration, palisade:spongy thickness ratio, and concentrations of inorganic P, nucleic acid P, lipid P and residual P. PPUE was negatively correlated with leaf inorganic P concentration and its percentage relative to leaf total P, while it was positively correlated with the concentration and percentage of metabolite P. We concluded that soybean domestication increased PPUE, as a result of both increased photosynthesis rate and decreased leaf P concentration; domestication reduced the palisade:spongy thickness ratio coupled with increased allocation of P to P-containing metabolites, thereby contributing to faster photosynthesis and higher PPUE. This study shed light on the significance of leaf P allocation and anatomical traits affecting PPUE during soybean domestication, offering a mechanistic understanding to further enhance soybean P-use efficiency.

Analysis of the Dynamic Expression of the SMAD Family in the Periosteum During Guided Bone Regeneration.

OBJECTIVE: The aim of this study was to investigate the dynamic expression of the SMAD family during guided bone regeneration for the reconstruction of cranio-maxillofacial bone defects. METHODS: A swine model of guided bone regeneration was established with one side of the rib as the trauma group and the contralateral as control group. Periosteal and regenerative tissue specimens were harvested at 9 time points in the early, middle, and late phases, and were subjected to gene sequencing and tissue staining. Expression data of each SMAD family were extracted for further analysis, in which the correlation of the expression of the respective members within and between groups and at different time points was analyzed. RESULTS: The expression of individual members of the SMAD family fluctuates greatly, especially during the first month. The SMAD3 and SMAD4 genes were the most highly expressed. The foldchange value of SMAD6 was the largest and remained above 1.5 throughout the process. The dynamic expression levels of SMAD2, SMAD4, SMAD5, SMAD6, and SMAD9 showed a significant positive correlation in both groups. The expression levels of each gene showed a positive correlation with other SMAD genes. Tissue staining showed that the overall contour of the regenerated bone tissue was basically formed within the first 1 month. CONCLUSION: The first month of guided bone regeneration is a critical period for bone regeneration and is an important period for the SMAD family to play a role. The SMAD6 may play an important role in the whole process of guided bone regeneration.

PRELP inhibits colorectal cancer progression by suppressing epithelial-mesenchymal transition and angiogenesis via the inactivation of the FGF1/PI3K/AKT pathway.

Proline/arginine-rich end and leucine-rich protein (PRELP) is identified as a small proteoglycan in the extracellular matrix that has been tightly associated with cell adhesion. At present, the role of PRELP in colorectal cancer (CRC) remains largely unknown. PRELP expression in human CRC tissue samples was analyzed by qRT-PCR and immunochemistry. CCK-8, colony formation, transwell, and tube formation assays were utilized to determine the influences of PRELP on the malignant phenotypes of CRC cells. Mouse xenograft and tumor metastasis models were constructed to further validate the function of PRELP. Furthermore, we investigated the efficacy of PRELP combined with bevacizumab treatment in a mouse xenograft model of CRC. Additionally, RNA-seq was performed to analyze the potential signaling pathways regulated by PRELP. Immunofluorescence staining and coimmunoprecipitation were conducted to confirm the interaction between PRELP and fibroblast growth factor 1 (FGF1). In this study, we found that PRELP exerted a tumor-suppressive effect on CRC. The expression level of PRELP was significantly reduced in CRC tissues and cell lines. Both in vivo and in vitro experiments confirmed that PRELP inhibited CRC cell proliferation, promoted apoptosis, and suppressed migration and invasion via a reduction in the epithelial-mesenchymal transition and attenuated angiogenesis, thereby dampening tumor progression. In addition, PRELP markedly potentiated the efficacy of bevacizumab in a mouse xenograft model. Mechanistically, PRELP bound to FGF1 and reduced the stability of the FGF1 protein, accompanied by an increase in its degradation, which subsequently inactivated the PI3K/AKT/mTOR pathway, thereby leading to reduction in tumor angiogenesis and metastasis. Our study for the first time unveiled the tumor-suppressive role of PRELP in CRC and provided a potential effective strategy for the treatment of CRC.

Patient-derived Organoid Pharmacotyping As A Predictive Tool for Therapeutic Selection in Pancreatic Ductal Adenocarcinoma.

OBJECTIVE: We integrate a new approach to chemosensitivity data for clinically-relevant regimen matching, and demonstrate the relationship with clinical outcomes in a large PDO biobank. SUMMARY BACKGROUND DATA: Pancreatic ductal adenocarcinoma (PDAC) usually recurs following potentially curative resection. Prior studies related patient-derived organoid (PDO) chemosensitivity with clinical responses. METHODS: PDOs were established from pre-treatment biopsies in a multi-institution clinical trial (n=21) and clinical specimens at a high-volume pancreatectomy center (n=74, of which 48 were pre-treated). PDO in vitro chemosensitivities to standard-of-care chemotherapeutics (pharmacotypes) were matched to potential clinically-relevant regimens by a weighted nearest-neighbors analysis. Clinical outcomes were then compared for patients who had well-matched versus poorly-matched treatment according to this metric. RESULTS: Our function matched 91% of PDOs to a standard-of-care regimen (9% pan-resistant). PDOs poorly-matched to the neoadjuvant regimen received would have matched to an alternative in 34% of cases. Patients receiving neoadjuvant chemotherapy well-matched to their pharmacotype experienced improved CA 19-9 response (60% decreased to normal when well-matched, 29% when poorly-matched, P<0.05) and lymph node down-staging (33% N0 after poorly-matched, 69% after well-matched, P<0.05). Patients receiving both well-matched neoadjuvant and adjuvant chemotherapy experienced improved recurrence-free- and overall survival (median RFS 8.5 mo poorly-matched, 15.9 mo well-matched, P<0.05; median OS 19.5 vs. 30.3 mo, P<0.05). CONCLUSION: In vitro PDO pharmacotyping can inform PDAC therapy selection. We demonstrate improved outcomes including survival for patients treated with regimens well-matched to their PDO chemosensitivities. A subsequent prospective study using PDO pharmacotype matching could improve oncologic outcomes and improve quality of life by avoiding therapies not expected to be effective.

A few-shot learning framework for the diagnosis of osteopenia and osteoporosis using knee X-ray images.

OBJECTIVE: We developed a few-shot learning (FSL) framework for the diagnosis of osteopenia and osteoporosis in knee X-ray images. METHODS: Computer vision models containing deep convolutional neural networks were fine-tuned to enable generalization from natural images (ImageNet) to chest X-ray images (normal vs. pneumonia, base images). Then, a series of automated machine learning classifiers based on the Euclidean distances of base images were developed to make predictions for novel images (normal vs. osteopenia vs. osteoporosis). The performance of the FSL framework was compared with that of junior and senior radiologists. In addition, the gradient-weighted class activation mapping algorithm was used for visual interpretation. RESULTS: In Cohort #1, the mean accuracy (0.728) and sensitivity (0.774) of the FSL models were higher than those of the radiologists (0.512 and 0.448). A diagnostic pipeline of FSL model (first)-radiologists (second) achieved better performance (0.653 accuracy, 0.582 sensitivity, and 0.816 specificity) than radiologists alone. In Cohort #2, the diagnostic pipeline also showed improved performance. CONCLUSIONS: The FSL framework yielded practical performance with respect to the diagnosis of osteopenia and osteoporosis in comparison with radiologists. This retrospective study supports the use of promising FSL methods in computer-aided diagnosis tasks involving limited samples.

Evaluation of AJCC Nodal Staging for Intraductal Papillary Mucinous Neoplasm-Derived Pancreatic Ductal Adenocarcinoma.

BACKGROUND: The American Joint Committee on Cancer (AJCC) eighth edition is based on pancreatic intraepithelial neoplasia-derived pancreatic ductal adenocarcinoma (PDAC), a biologically distinct entity from intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic cancer. The role of nodal disease and the AJCC's prognostic utility for IPMN-derived pancreatic cancer are unclear. This study aimed to evaluate the prognostic role of nodal disease and the AJCC eighth-edition N-staging for IPMN-derived pancreatic cancer. METHODS: Upfront-surgery patients with IPMN-derived PDAC from four centers were stratified according to the AJCC eighth-edition N stage. Disease characteristics were compared using descriptive statistics, and both overall survival (OS) and recurrence-free survival (RFS) were evaluated using log-rank tests. Multivariable Cox regression was performed to determine the prognostic value of N stage for OS, presented as hazard ratios with 95 % confidence intervals (95 % CIs). A lowest p value log-rank statistic was used to derive the optimal cutoff for node-positive disease. RESULTS: For 360 patients, advanced N stage was associated with worse T stage, grade, tubular histology, and perineural and lymphovascular invasion (all p < 0.05). The median OS was 98.3 months (95 % CI 82.8-122.0 months) for N0 disease, 27.8 months (95 % CI 24.4-41.7 months) for N1 disease, and 18.1 months (95 % CI 16.2-25.9 months) for N2 disease (p < 0.001). The AJCC N stage was validated and associated with worse OS (N1 [HR 1.64; range, 1.05-2.57], N2 [HR2.42; range, 1.48-3.96]) and RFS (N1 [HR 1.81; range, 1.23-2.68], N2 [HR 3.72; range, 2.40-5.77]). The optimal cutoff for positive nodes was five nodes. CONCLUSION: The AJCC eighth-edition N-staging is valid and prognostic for both OS and RFS in IPMN-derived PDAC.

Comparison of postoperative analgesia by thoracoscopic-guided thoracic paravertebral block and thoracoscopic-guided intercostal nerve block in uniportal video-asssited thoracic surgery: a prospective randomized controlled trial.

BACKGROUND: Thoracoscopic-guided thoracic paravertebral nerve block (TG-TPVB) and thoracoscopic-guided intercostal nerve block (TG-INB) are two postoperative analgesia technology for thoracic surgery. This study aims to compared the analgesic effect of TG-TPVB and TG-INB after uniportal video-asssited thoracic surgery (UniVATS). METHODS: Fifty-eight patients were randomly allocated to the TG-TPVB group and the TG-INB group. The surgical time of nerve block, the visual analog scale (VAS) scores, the consumption of sufentanil and the number of patient-controlled intravenous analgesic (PCIA) presses within 24 h after surgery, the incidence of adverse reactions were compared between the two groups. RESULTS: The VAS scores were significantly lower during rest and coughing at 2, 6, 12, and 24 h in the TG-TPVB group than in the TG-INB group (P < 0.05). The consumption of sufentanil and the number of PCIA presses within 24 h after surgery were significantly lower in the TG-TPVB group than in the TG-INB group (P < 0.001).The surgical time of nerve block was significantly shorter in the TG-TPVB group than in the TG-INB group (P < 0.001). The incidence of bleeding at the puncture point was lower in the TG-TPVB group than that in the TG-INB group (P < 0.05). CONCLUSION: TG-TPVB demonstrated superior acute pain relieve after uniVATS, shorter surgical time and non-inferior adverse effects than TG-INB.

Impact of Adjuvant Chemotherapy on Resected Intraductal Papillary Mucinous Neoplasm-Derived Pancreatic Cancer: Results From an International Multicenter Study.

PURPOSE: The benefit of adjuvant therapy for intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) remains unclear because of severely limited evidence. Although biologically distinct entities, adjuvant therapy practices for IPMN-derived PDAC are largely founded on pancreatic intraepithelial neoplasia-derived PDAC. We aimed to evaluate the role of adjuvant chemotherapy in IPMN-derived PDAC. METHODS: This international multicenter retrospective cohort study (2005-2018) was conceived at the Verona Evidence-Based Medicine meeting. Cox regressions were performed to identify risk-adjusted hazard ratios (HR) associated with overall survival (OS). Kaplan-Meier curves and log-rank tests were employed for survival analysis. Logistic regression was performed to identify factors motivating adjuvant chemotherapy administration. A decision tree was proposed and categorized patients into overtreated, undertreated, and optimally treated cohorts. RESULTS: In 1,031 patients from 16 centers, nodal disease (HR, 2.88, P < .001) and elevated (≥37 to <200 µ/mL, HR, 1.44, P = .006) or markedly elevated (≥200 µ/mL, HR, 2.53, P < .001) carbohydrate antigen 19-9 (CA19-9) were associated with worse OS. Node-positive patients with elevated CA19-9 had an associated 34.4-month improvement in median OS (P = .047) after adjuvant chemotherapy while those with positive nodes and markedly elevated CA19-9 had an associated 12.6-month survival benefit (P < .001). Node-negative patients, regardless of CA19-9, did not have an associated benefit from adjuvant chemotherapy (all P > .05). Based on this model, we observed undertreatment in 18.1% and overtreatment in 61.2% of patients. Factors associated with chemotherapy administration included younger age, R1-margin, poorer differentiation, and nodal disease. CONCLUSION: Almost half of patients with resected IPMN-derived PDAC may be overtreated or undertreated. In patients with node-negative disease or normal CA19-9, adjuvant chemotherapy is not associated with a survival benefit, whereas those with node-positive disease and elevated CA19-9 have an associated benefit from adjuvant chemotherapy. A decision tree was proposed. Randomized controlled trials are needed for validation.

Performance of explainable artificial intelligence in guiding the management of patients with a pancreatic cyst.

BACKGROUND/OBJECTIVES: Pancreatic cyst management can be distilled into three separate pathways - discharge, monitoring or surgery- based on the risk of malignant transformation. This study compares the performance of artificial intelligence (AI) models to clinical care for this task. METHODS: Two explainable boosting machine (EBM) models were developed and evaluated using clinical features only, or clinical features and cyst fluid molecular markers (CFMM) using a publicly available dataset, consisting of 850 cases (median age 64; 65 % female) with independent training (429 cases) and holdout test cohorts (421 cases). There were 137 cysts with no malignant potential, 114 malignant cysts, and 599 IPMNs and MCNs. RESULTS: The EBM and EBM with CFMM models had higher accuracy for identifying patients requiring monitoring (0.88 and 0.82) and surgery (0.66 and 0.82) respectively compared with current clinical care (0.62 and 0.58). For discharge, the EBM with CFMM model had a higher accuracy (0.91) than either the EBM model (0.84) or current clinical care (0.86). In the cohort of patients who underwent surgical resection, use of the EBM-CFMM model would have decreased the number of unnecessary surgeries by 59 % (n = 92), increased correct surgeries by 7.5 % (n = 11), identified patients who require monitoring by 122 % (n = 76), and increased the number of patients correctly classified for discharge by 138 % (n = 18) compared to clinical care. CONCLUSIONS: EBM models had greater sensitivity and specificity for identifying the correct management compared with either clinical management or previous AI models. The model predictions are demonstrated to be interpretable by clinicians.

Informing Decision-making for Transected Margin Reresection in Intraductal Papillary Mucinous Neoplasm-derived PDAC: An International Multicenter Study.

OBJECTIVE: To assess the prognostic impact of margin status in patients with resected intraductal papillary mucinous neoplasms (IPMN)-derived pancreatic ductal adenocarcinoma (PDAC) and to inform future intraoperative decision-making on handling differing degrees of dysplasia on frozen section. SUMMARY BACKGROUND DATA: The ideal oncologic surgical outcome is a negative transection margin with normal pancreatic epithelium left behind. However, the prognostic significance of reresecting certain degrees of dysplasia or invasive cancer at the pancreatic neck margin during pancreatectomy for IPMN-derived PDAC is debatable. METHODS: Consecutive patients with resected and histologically confirmed IPMN-derived PDAC (2002-2022) from six international high-volume centers were included. The prognostic relevance of a positive resection margin (R1) and degrees of dysplasia at the pancreatic neck margin were assessed by log-rank test and multivariable Cox-regression for overall survival (OS) and recurrence-free survival (RFS). RESULTS: Overall, 832 patients with IPMN-derived PDAC were included with 322 patients (39%) having an R1-resection on final pathology. Median OS (mOS) was significantly longer in patients with an R0 status compared to those with an R1 status (65.8 vs. 26.3 mo P<0.001). Patients without dysplasia at the pancreatic neck margin had similar OS compared to those with low-grade dysplasia (mOS: 78.8 vs. 66.8 months, P=0.344). However, high-grade dysplasia (mOS: 26.1 mo, P=0.001) and invasive cancer (mOS: 25.0 mo, P<0.001) were associated with significantly worse OS compared to no or low-grade dysplasia. Patients who underwent conversion of high-risk margins (high-grade or invasive cancer) to a low-risk margin (low-grade or no dysplasia) after intraoperative frozen section had significantly superior OS compared to those with a high-risk neck margin on final pathology (mOS: 76.9 vs. 26.1 mo P<0.001). CONCLUSIONS: In IPMN-derived PDAC, normal epithelium or low-grade dysplasia at the neck have similar outcomes while pancreatic neck margins with high-grade dysplasia or invasive cancer are associated with poorer outcomes. Conversion of a high-risk to low-risk margin after intraoperative frozen section is associated with survival benefit and should be performed when feasible.

More sensitive microbial responses to the interactive effects of warming and altered precipitation in subsoil than topsoil of an alpine grassland ecosystem.

Subsoil is a large organic carbon reservoir, storing more than half of the total soil organic carbon (SOC) globally. Conventionally, subsoil is assumed to not be susceptible to climate change, but recent studies document that climate change could significantly alter subsoil carbon cycling. However, little is known about subsoil microbial responses to the interactive effects of climate warming and altered precipitation. Here, we investigated carbon cycling and associated microbial responses in both subsoil (30-40 cm) and topsoil (0-10 cm) in a Tibetan alpine grassland over 4 years of warming and altered precipitation. Compared to the unchanged topsoil carbon (ß = .55, p = .587), subsoil carbon exhibited a stronger response to the interactive effect of warming and altered precipitation (ß = 2.04, p = .021), that is, warming decreased subsoil carbon content by 28.20% under decreased precipitation while warming increased subsoil carbon content by 18.02% under increased precipitation.Furthermore, 512 metagenome-assembled genomes (MAGs) were recovered, including representatives of phyla with poor genomic representation. Compared to only one changed topsoil MAG, 16 subsoil MAGs were significantly affected by altered precipitation, and 5 subsoil MAGs were significantly affected by the interactive effect of warming and precipitation. More than twice as many populations whose MAG abundances correlated significantly with the variations of carbon content, components and fluxes were observed in the subsoil than topsoil, suggesting their potential contribution in mediating subsoil carbon cycling. Collectively, our findings highlight the more sensitive responses of specific microbial lineages to the interactive effects of warming and altered precipitation in the subsoil than topsoil, and provide key information for predicting subsoil carbon cycling under future climate change scenarios.

Andrographolide sensitizes glioma to temozolomide by inhibiting DKK1 expression.

BACKGROUND: Temozolomide (TMZ) is the first-line chemotherapeutic drug for gliomas treatment. However, the clinical efficacy of TMZ in glioma patients was very limited. Therefore, it is urgently needed to discover a novel approach to increase the sensitivity of glioma cells to TMZ. METHODS: Western blot, immunohistochemical staining, and qRT-PCR assays were used to explore the mechanisms underlying TMZ promoting DKK1 expression and andrographolide (AND) inhibiting DKK1 expression. HPLC was used to detect the ability of andrographolide (AND) to penetrate the blood-brain barrier. MTT assay, bioluminescence images, magnetic resonance imaging (MRI) and H&E staining were employed to measure the proliferative activity of glioma cells and the growth of intracranial tumors. RESULTS: TMZ can promote DKK1 expression in glioma cells and brain tumors of an orthotopic model of glioma. DKK1 could promote glioma cell proliferation and tumor growth in an orthotopic model of glioma. Mechanistically, TMZ increased EGFR expression and subsequently induced the activation of its downstream MEK-ERK and PI3K-Akt pathways, thereby promoting DKK1 expression in glioma cells. Andrographolide inhibited TMZ-induced DKK1 expression through inactivating MEK-ERK and PI3K-Akt pathways. Andrographolide can cross the blood-brain barrier, the combination of TMZ and andrographolide not only improved the anti-tumor effects of TMZ but also showed a survival benefit in an orthotopic model of glioma. CONCLUSION: Andrographolide can enhance anti-tumor activity of TMZ against glioma by inhibiting DKK1 expression.