The gut protist Tritrichomonas arnold restrains virus-mediated loss of oral tolerance by modulating dietary antigen-presenting dendritic cells.

Loss of oral tolerance (LOT) to gluten, driven by dendritic cell (DC) priming of gluten-specific T helper 1 (Th1) cell immune responses, is a hallmark of celiac disease (CeD) and can be triggered by enteric viral infections. Whether certain commensals can moderate virus-mediated LOT remains elusive. Here, using a mouse model of virus-mediated LOT, we discovered that the gut-colonizing protist Tritrichomonas (T.) arnold promotes oral tolerance and protects against reovirus- and murine norovirus-mediated LOT, independent of the microbiota. Protection was not attributable to antiviral host responses or T. arnold-mediated innate type 2 immunity. Mechanistically, T. arnold directly restrained the proinflammatory program in dietary antigen-presenting DCs, subsequently limiting Th1 and promoting regulatory T cell responses. Finally, analysis of fecal microbiomes showed that T. arnold-related Parabasalid strains are underrepresented in human CeD patients. Altogether, these findings will motivate further exploration of oral-tolerance-promoting protists in CeD and other immune-mediated food sensitivities.

Grid cells use HCN1 channels for spatial scaling.

Entorhinal grid cells have periodic, hexagonally patterned firing locations that scale up progressively along the dorsal-ventral axis of medial entorhinal cortex. This topographic expansion corresponds with parallel changes in cellular properties dependent on the hyperpolarization-activated cation current (Ih), which is conducted by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. To test the hypothesis that grid scale is determined by Ih, we recorded grid cells in mice with forebrain-specific knockout of HCN1. We find that, although the dorsal-ventral gradient of the grid pattern was preserved in HCN1 knockout mice, the size and spacing of the grid fields, as well as the period of the accompanying theta modulation, was expanded at all dorsal-ventral levels. There was no change in theta modulation of simultaneously recorded entorhinal interneurons. These observations raise the possibility that, during self-motion-based navigation, Ih contributes to the gain of the transformation from movement signals to spatial firing fields.

Field-resolved infrared spectroscopy of biological systems.

The proper functioning of living systems and physiological phenotypes depends on molecular composition. Yet simultaneous quantitative detection of a wide variety of molecules remains a challenge1-8. Here we show how broadband optical coherence opens up opportunities for fingerprinting complex molecular ensembles in their natural environment. Vibrationally excited molecules emit a coherent electric field following few-cycle infrared laser excitation9-12, and this field is specific to the sample's molecular composition. Employing electro-optic sampling10,12-15, we directly measure this global molecular fingerprint down to field strengths 107 times weaker than that of the excitation. This enables transillumination of intact living systems with thicknesses of the order of 0.1 millimetres, permitting broadband infrared spectroscopic probing of human cells and plant leaves. In a proof-of-concept analysis of human blood serum, temporal isolation of the infrared electric-field fingerprint from its excitation along with its sampling with attosecond timing precision results in detection sensitivity of submicrograms per millilitre of blood serum and a detectable dynamic range of molecular concentration exceeding 105. This technique promises improved molecular sensitivity and molecular coverage for probing complex, real-world biological and medical settings.

Intratumoral Cell Neighborhoods Coordinate Outcomes in Pancreatic Ductal Adenocarcinoma.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease characterized by a spatially heterogeneous tumor microenvironment. Within the PDA microenvironment, cells organize into communities where cell fate is influenced by neighboring cells of diverse ontogeny and function. However, it remains unclear how cell neighborhoods in the tumor microenvironment evolve with treatment and impact clinical outcomes. METHODS: Here, using automated chromogenic multiplex immunohistochemistry and unsupervised computational image analysis of human PDA tumors, we investigated cell neighborhoods in surgically resected tumors from patients with chemotherapy-naïve PDA (n = 59) and neoadjuvant chemotherapy-treated PDA (n = 57). Single cells were defined by lineage markers (CD3, CD8, Foxp3, CD68, CK19), proliferation (Ki67), and neighboring cells. RESULTS: Distinct intratumoral immune and tumor cell subsets were defined by neighboring cells. Higher content of stromal-associated macrophages was seen in chemotherapy-naïve tumors from long-term survivors (overall survival >3 years) compared with short-term survivors (overall survival <1 year), whereas immune-excluded tumor cells were higher in short-term survivors. Chemotherapy-treated vs -naïve tumors showed lower content of tumor-associated T cells and macrophages but similar densities of stromal-associated immune cells. However, proliferating tumor cell subsets with immune-rich neighborhoods were higher in chemotherapy-treated tumors. In a blinded analysis of tumors from patients treated with neoadjuvant chemotherapy, a composite index comprising lower quantities of immune-excluded tumor cells and higher spatially distinct immune cell subsets was associated with prolonged survival. CONCLUSIONS: Together, these data provide new insights into discrete cell communities in PDA and show their clinical relevance.

Mapping the Evolutionary Space of SARS-CoV-2 Variants to Anticipate Emergence of Subvariants Resistant to COVID-19 Therapeutics.

New sublineages of SARS-CoV-2 variants-of-concern (VOCs) continuously emerge with mutations in the spike glycoprotein. In most cases, the sublineage-defining mutations vary between the VOCs. It is unclear whether these differences reflect lineage-specific likelihoods for mutations at each spike position or the stochastic nature of their appearance. Here we show that SARS-CoV-2 lineages have distinct evolutionary spaces (a probabilistic definition of the sequence states that can be occupied by expanding virus subpopulations). This space can be accurately inferred from the patterns of amino acid variability at the whole-protein level. Robust networks of co-variable sites identify the highest-likelihood mutations in new VOC sublineages and predict remarkably well the emergence of subvariants with resistance mutations to COVID-19 therapeutics. Our studies reveal the contribution of low frequency variant patterns at heterologous sites across the protein to accurate prediction of the changes at each position of interest.

Systemic anticancer therapy for urothelial carcinoma: UK oncologists' perspective.

Urothelial carcinoma (UC) is a common cancer associated with a poor prognosis in patients with advanced disease. Platinum-based chemotherapy has remained the cornerstone of systemic anticancer treatment for many years, and recent developments in the treatment landscape have improved outcomes. In this review, we provide an overview of systemic treatment for UC, including clinical data supporting the current standard of care at each point in the treatment pathway and author interpretations from a UK perspective. Neoadjuvant cisplatin-based chemotherapy is recommended for eligible patients with muscle-invasive bladder cancer and is preferable to adjuvant treatment. For first-line treatment of advanced UC, platinum-eligible patients should receive cisplatin- or carboplatin-based chemotherapy, followed by avelumab maintenance in those without disease progression. Among patients unable to receive platinum-based chemotherapy, immune checkpoint inhibitor (ICI) treatment is an option for those with programmed death ligand 1 (PD-L1)-positive tumours. Second-line or later treatment options depend on prior treatment, and enfortumab vedotin is preferred after prior ICI and chemotherapy, although availability varies between countries. Additional options include rechallenge with platinum-based chemotherapy, an ICI, or non-platinum-based chemotherapy. Areas of uncertainty include the optimal number of first-line chemotherapy cycles for advanced UC and the value of PD-L1 testing for UC.

The Banff 2022 Kidney Meeting Work Plan: Data-driven refinement of the Banff Classification for renal allografts.

The XVIth Banff Meeting for Allograft Pathology was held in Banff, Alberta, Canada, from September 19 to 23, 2022, as a joint meeting with the Canadian Society of Transplantation. In addition to a key focus on the impact of microvascular inflammation and biopsy-based transcript analysis on the Banff Classification, further sessions were devoted to other aspects of kidney transplant pathology, in particular T cell-mediated rejection, activity and chronicity indices, digital pathology, xenotransplantation, clinical trials, and surrogate endpoints. Although the output of these sessions has not led to any changes in the classification, the key role of Banff Working Groups in phrasing unanswered questions, and coordinating and disseminating results of investigations addressing these unanswered questions was emphasized. This paper summarizes the key Banff Meeting 2022 sessions not covered in the Banff Kidney Meeting 2022 Report paper and also provides an update on other Banff Working Group activities relevant to kidney allografts.

Whole-Genome Sequencing Analysis of Male Breast Cancer Unveils Novel Structural Events and Potential Therapeutic Targets.

The molecular characterization of male breast cancer (MaBC) has received limited attention in research, mostly because of its low incidence rate, accounting for only 0.5% to 1% of all reported cases of breast cancer each year. Managing MaBC presents significant challenges, with most treatment protocols being adapted from those developed for female breast cancer. Utilizing whole-genome sequencing (WGS) and state-of-the-art analyses, the genomic features of 10 MaBC cases (n = 10) were delineated and correlated with clinical and histopathologic characteristics. Using fluorescence in situ hybridization, an additional cohort of 18 patients was interrogated to supplement WGS findings. The genomic landscape of MaBC uncovered significant genetic alterations that could influence diagnosis and treatment. We found common somatic mutations in key driver genes, such as FAT1, GATA3, SMARCA4, and ARID2. Our study also mapped out structural variants that impact cancer-associated genes, such as ARID1A, ESR1, GATA3, NTRK1, and NF1. Using a WGS-based classifier, homologous recombination deficiency (HRD) was identified in 2 cases, both presenting with deleterious variants in BRCA2. Noteworthy was the observation of FGFR1 amplification in 21% of cases. Altogether, we identified at least 1 potential therapeutic target in 8 of the 10 cases, including high tumor mutational burden, FGFR1 amplification, and HRD. Our study is the first WGS characterization of MaBC, which uncovered potentially relevant variants, including structural events in cancer genes, HRD signatures, and germline pathogenic mutations. Our results demonstrate unique genetic markers and potential treatment targets in MaBC, thereby underlining the necessity of tailoring treatment strategies for this understudied patient population. These WGS-based findings add to the growing knowledge of MaBC genomics and highlight the need to expand research on this type of cancer.

ASO Practice Guidelines Series: Management of Resectable, Borderline Resectable, and Locally Advanced Pancreas Cancer.

Pancreatic adenocarcinoma is an aggressive disease marked by high rates of both local and distant failure. In the minority of patients with potentially resectable disease, multimodal treatment paradigms have allowed for prolonged survival in an increasingly larger pool of well-selected patients. Therefore, it is critical for surgical oncologists to be abreast of current guideline recommendations for both surgical management and multimodal therapy for pancreas cancer. We discuss these guidelines, as well as the underlying data supporting these positions, to offer surgical oncologists a framework for managing patients with pancreatic adenocarcinoma.

Postoperative Adverse Events Following Neoadjuvant Therapy and Surgery for Borderline Resectable Pancreatic Cancer in a Phase 2 Clinical Trial (Alliance A021501).

BACKGROUND: Postoperative adverse events (AEs) in patients with borderline resectable pancreatic ductal adenocarcinoma (BR-PC) treated with neoadjuvant therapy and pancreatectomy in the national cooperative group setting have not been previously characterized. We conducted a preplanned secondary analysis of patients enrolled on the Alliance A021501 clinical trial to quantify perioperative AE rates. METHODS: The A021501 phase 2 trial randomized patients with BR-PC to receive 8 doses of mFOLFIRINOX (Arm 1) or 7 doses of mFOLFIRINOX and hypofractionated radiotherapy (Arm 2), followed by pancreatectomy (December 31, 2016 to May 31, 2019). Adverse events were assessed 90 days after pancreatectomy. RESULTS: Of 126 enrolled patients, 51 (40%) underwent pancreatectomy (n = 32, Arm 1; n = 19, Arm 2) at 28 institutions. Five (10%) patients required reoperation within 90 days; 56% of patients (n = 27/48) experienced at least one grade 3 or higher AE (50% vs. 67%, p = 0.37). Ninety-day mortality was 2.0%. Readmission was less frequent in Arm 1 (16% vs. 42%, p = 0.05), but there were no differences between study arms in rates of reoperation (13% vs. 5%), pancreatic fistula or intra-abdominal abscess requiring drainage (9% vs. 16%), or wound infection (6% vs. 16%). Pancreatic fistula or intra-abdominal abscess requiring drainage was associated with receipt of adjuvant therapy (p = 0.012). No difference in overall survival was observed based on occurrence of postoperative AEs (hazard ratio = 1.1; 95% confidence interval 0.5-2.6). CONCLUSIONS: In this multicenter study, rates of postoperative AEs were consistent with those previously reported. Multimodality trials of preoperative therapy for BR-PC may be performed in the cooperative group setting with careful quality assurance and safety monitoring. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02839343.

The Top Ten Annals of Surgical Oncology Original Articles on Twitter/X: 2020-2023.

Social media has become omnipresent in society, especially given that it enables the rapid and widespread communication of news, events, and information. Social media platforms have become increasingly used by numerous surgical societies to promote meetings and surgical journals to increase the visibility of published content. In September 2020, Annals of Surgical Oncology (ASO) established its Social Media Committee (SMC), which has worked to steadily increase the visibility of published content on social media platforms, namely X (formerly known as Twitter). The purpose of this review is to highlight the 10 ASO original articles with the most engagement on X, based on total number of mentions, since the founding of the SMC. These articles encompass a wide variety of topics from various oncologic disciplines including hepatopancreatobiliary, breast, and gynecologic surgery.

Xenografted human iPSC-derived neurons with the familial Alzheimer's disease APPV717I mutation reveal dysregulated transcriptome signatures linked to synaptic function and implicate LINGO2 as a disease signaling mediator.

Alzheimer's disease (AD) is the most common cause of dementia, and disease mechanisms are still not fully understood. Here, we explored pathological changes in human induced pluripotent stem cell (iPSC)-derived neurons carrying the familial AD APPV717I mutation after cell injection into the mouse forebrain. APPV717I mutant iPSCs and isogenic controls were differentiated into neurons revealing enhanced Aß42 production, elevated phospho-tau, and impaired neurite outgrowth in APPV717I neurons. Two months after transplantation, APPV717I and control neural cells showed robust engraftment but at 12 months post-injection, APPV717I grafts were smaller and demonstrated impaired neurite outgrowth compared to controls, while plaque and tangle pathology were not seen. Single-nucleus RNA-sequencing of micro-dissected grafts, performed 2 months after cell injection, identified significantly altered transcriptome signatures in APPV717I iPSC-derived neurons pointing towards dysregulated synaptic function and axon guidance. Interestingly, APPV717I neurons showed an increased expression of genes, many of which are also upregulated in postmortem neurons of AD patients including the transmembrane protein LINGO2. Downregulation of LINGO2 in cultured APPV717I neurons rescued neurite outgrowth deficits and reversed key AD-associated transcriptional changes related but not limited to synaptic function, apoptosis and cellular senescence. These results provide important insights into transcriptional dysregulation in xenografted APPV717I neurons linked to synaptic function, and they indicate that LINGO2 may represent a potential therapeutic target in AD.

Interplay between gain and loss in arrays of nonlinear plasmonic nanoparticles: toward parametric downconversion and amplification.

With the help of a theoretical model and finite-difference time-domain (FDTD) simulations based on the hydrodynamic-Maxwell model, we examine the effect of difference-frequency generation (DFG) in an array of L-shaped metal nanoparticles (MNPs) characterized by intrinsic plasmonic nonlinearity. The outcomes of the calculations reveal the spectral interplay between gain and loss in the vicinity of the fundamental frequency of the localized surface plasmon resonances. Subsequently, we identify different array thicknesses and pumping regimes facilitating parametric amplification and spontaneous parametric downconversion. Our results suggest that the parametric amplification regime becomes feasible on a scale of hundreds of nanometers and spontaneous parametric downconversion on the scale of tens of nanometers, opening up new exciting opportunities for developing building blocks of photonic metasurfaces.

Real-word outcomes for high-risk non-muscle-invasive bladder cancer: screened patients for the BRAVO trial.

OBJECTIVE: To report real-world outcomes for high-risk non-muscle-invasive bladder cancer (HRNMIBC), including bacillus Calmette-Guérin (BCG) and radical cystectomy (RC), as randomised comparisons of these have not been possible. METHODS: We detail consecutive participants screened for the BRAVO randomised controlled trial comparing RC with BCG (International Standard Randomised Controlled Trial Number [ISRCTN]12509361). Patients were prospectively registered and case-note review used for outcomes. The primary outcome was overall survival. Secondary outcomes included recurrence, progression, metastasis, and bladder cancer-specific survival. RESULTS AND LIMITATIONS: A total of 193 patients were screened, including 106 (54.9%) who received BCG, 43 (22.3%) primary RC, 37 (19.2%) 'other' treatment and seven (3.6%) hyperthermic intravesical mitomycin C. All-cause death occurred in 55 (28.5%) patients at median (interquartile range [IQR]) of 29.0 (19.5-42.0) months. In multivariable analysis, overall mortality was more common in older patients (hazard ratio [HR] 2.63, 95% confidence interval [CI] 1.35-5.13; Cox P = 0.004 for age >70 years), those recruited from district hospitals (HR 0.53, 95% CI 0.3-0.95; P = 0.032) and those who did not undergo RC as their first treatment (HR 2.16, 95% CI 1.17-3.99; P = 0.014). In all, 17 (8.8%) patients died from bladder cancer (BC) at median (IQR) of 22.5 (19-36.25) months. In multivariable analysis, BC-specific mortality was more common in older patients (HR 4.87, 95% CI 1.1-21.6; P = 0.037) and those with Tis/T1 disease (HR 2.26, 95% CI 1.23-4.16; P = 0.008) but did not vary with initial treatment. CONCLUSIONS: Patients with HRNMIBC are at high-risk of mortality. Those choosing RC as their initial treatment have lower risks of mortality than others, although this may reflect fitness and selection.

The Impact of a Modular Robotic Total Mesorectal Excision Training Program on Perioperative and Oncological Outcomes in Robotic Rectal Cancer Surgery.

BACKGROUND: Structured training programs for robotic colorectal surgery are limited, and there are concerns about surgical outcomes and operating times. OBJECTIVE: To compare perioperative and oncological outcomes of robotic total mesorectal excision for rectal cancer performed by expert consultants and surgical trainees in a modular surgical training program. DESIGN: Retrospective cohort study. SETTINGS: Conducted at a colorectal training referral center for robotic surgery. PATIENTS: Consecutive robotic total mesorectal excision cases between May 2013 and December 2017 were evaluated retrospectively from a prospectively maintained institutional database and divided into 2 groups: group I comprised expert surgeons and group II comprised supervised trainees. Robotic total mesorectal excision training modules (5 modules) were performed stepwise with increasing complexity. Patients' demographic, perioperative, and oncological data were collected. INTERVENTIONS: Modular robotic training. MAIN OUTCOME MEASURES: Comparable R0 resection rate, lymph node harvest, and oncological outcomes between experts and trainees, suggesting good quality in oncological resection. RESULTS: A total of 177 robotic total mesorectal excision resections were performed (group I: n = 80, group II: n = 97). Four trainees completed 37.5 modules each. Patients' age, sex, and BMI were similar between groups. Group II had a higher ASA III score (6.3% vs 25.8%, p = 0.002). Clinical TNM and neoadjuvant chemoradiotherapy rates were similar. Group II had a longer operative time (225 [197.5-297.5] vs 250 [230-300] minutes, p = 0.004). No conversion occurred. There were no differences in intra- or postoperative outcomes between groups. The rate of R0 resection and the number of harvested lymph nodes were also similar between groups. The median follow-up was 75 (64.0-81.7) and 47 (38.0-55.0) months, respectively. Local and distant recurrence rates, 5-year overall survival (81.1% group I vs 81.3% group II, p = 0.832), and 5-year disease-free survival (79.7% group I vs 80.7% group II, p = 0.725) were similar between groups. LIMITATIONS: The groups operated in 2 consecutive periods. CONCLUSIONS: The robotic total mesorectal excision modular surgical training program maximizes training experience without significantly affecting the perioperative and oncological outcomes of patients with rectal cancer. See Video Abstract. EL IMPACTO DEL PROGRAMA MODULAR DE ENTRENAMIENTO EN ESCISIN MESORRECTAL TOTAL ROBTICA EN LOS RESULTADOS PERIOPERATORIOS Y ONCOLGICOS EN LA CIRUGA ROBTICA DEL CNCER DE RECTO: ANTECEDENTES:Los programas de entrenamiento estructurados para la cirugía colorrectal robótica están limitados debido a preocupaciones sobre los resultados quirúrgicos y los tiempos de operación.OBJETIVO:Comparar los resultados perioperatorios y oncológicos de la escisión mesorrectal total robótica para el cáncer de recto realizada por consultores expertos y aprendices de cirugía en un programa modular de entrenamiento quirúrgica.DISEÑO:Estudio de cohorte retrospectivo.AJUSTES:Realizado en un centro de referencia de entrenamiento colorrectal para cirugía robótica.PACIENTES:Se evaluaron retrospectivamente casos consecutivos de escisión mesorrectal total robótica entre mayo de 2013 y diciembre de 2017 a partir de una base de datos institucional mantenida prospectivamente y se dividieron en dos grupos: Grupo I: cirujanos expertos; Grupo II: aprendices supervisados. Los módulos de entrenamiento robótico de escisión mesorrectal total (cinco módulos) se realizaron paso a paso con complejidad creciente. Se recogieron datos demográficos, perioperatorios y oncológicos.INTERVENCIONES:Entrenamiento modular en robótica.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de resección R0 comparable, extracción de ganglios linfáticos y resultados oncológicos entre expertos y aprendices que sugieren buena calidad en la resección oncológica.RESULTADOS:Se realizaron un total de 177 resecciones por escisión mesorrectal total robótica (Grupo I: n = 80, Grupo II: n = 97). Cuatro alumnos completaron 37,5 módulos cada uno. La edad, el sexo y el IMC fueron similares entre los grupos. El grupo II tuvo una puntuación más alta de la Sociedad Americana de Anestesiólogos III (6,3% frente a 25,8%, p = 0,002). Las tasas clínicas de TNM y quimiorradioterapia neoadyuvante fueron similares. El grupo II tuvo mayor tiempo operatorio (225 (197,5-297,5) vs 250 (230-300) minutos, p = 0,004). No se produjo ninguna conversión. No hubo diferencias en los resultados intra o posoperatorios entre los grupos. La tasa de resección R0 y el número de ganglios linfáticos extraídos también fueron similares entre los grupos. La mediana de seguimiento fue de 75 (64,0-81,7) y 47 (38,0-55,0) meses, respectivamente. Tasas de recurrencia local y a distancia, supervivencia general a 5 años (81,1% Grupo I vs. 81,3% Grupo II, p = 0,832) y supervivencia libre de enfermedad a 5 años (79,7% Grupo I vs. 80,7% Grupo II, p = 0,725) fueron similares entre los grupos.LIMITACIONES:Los grupos operaron en dos períodos consecutivos.CONCLUSIONES:El programa de entrenamiento quirúrgico modular para la escisión mesorrectal total robótica maximiza la experiencia de capacitación sin afectar significativamente los resultados perioperatorios y oncológicos de los pacientes con cáncer de recto. (Traducción-Dr. Aurian Garcia Gonzalez).

National Landscape of Neoadjuvant Therapy in Potentially Resectable Colon Cancer.

INTRODUCTION: Surgery followed by pathology-guided adjuvant therapy is standard treatment for colon cancer. Data from the FOxTROT clinical trial showed potential benefit of a 6-wk neoadjuvant chemotherapy (NACT) in T3/T4 patients. The present study evaluated real-world outcomes of neoadjuvant therapy in a national cohort of patients with resectable colon cancer. METHODS: 169,120 patients with clinical stage I, II, or III colon cancer from the National Cancer Database registry were included. Patients were categorized as having received neoadjuvant therapy followed by surgery (NACT), surgery then adjuvant chemotherapy (AC), or surgery alone. Factors associated with treatment sequencing and outcomes were assessed. RESULTS: Of identified patients, 1.4% received NACT including 0.5% of stage I, 1.8% of stage II, and 3.0% of stage III. For stage I, 5-y overall survival (OS) was 74.7% after AC, 62.2% after NACT, and 76.4% after SA. For stage II, 5-y OS was 73.2% after AC, 66.8% after NACT, and 64.3% after SA. For stage III, 5-y OS was 67.3% after AC, 67.7% after NACT, and 42.4% after SA. Cox proportional-hazards model suggested NACT had worse outcomes versus AC in clinical stages I (hazard ratio [HR] = 1.59, 95% confidence interval [CI] 1.39-1.85, P < 0.01) and II (HR = 1.37, 95% CI 1.23-1.52, P < 0.01). In stage III, there was no difference in OS between NACT and AC (HR = 1.1, 95% CI 0.99-1.22, P = 0.05). CONCLUSIONS: In a real-world national cohort of patients with resectable colon cancer, NACT had no OS benefit over AC. Future studies should examine which subset of patients might benefit from neoadjuvant approaches.

Contemporary Outcomes of Grade-C Postoperative Pancreatic Fistula in a Nationwide Database.

INTRODUCTION: Grade-C postoperative pancreatic fistulas (POPFs) are dreaded complications following pancreaticoduodenectomy. The aim of this study was to quantify the incidence and risk factors associated with grade C POPF in a national database. METHODS: The National Surgical Quality Improvement Program targeted user files were queried for patients who underwent elective pancreaticoduodenectomy (2014-2020). Outcomes were compared between clinically relevant (CR) grade B POPF and grade C POPF. RESULTS: Twenty-six thousand five hundred fifty-two patients were included, of which 90.1% (n = 23,714) had No CR POPF, 8.7% (n = 2287) suffered grade B POPF, and 1.2% (n = 327) suffered grade C POPF. There was no change in the rate Grade-C fistula overtime (m = 0.06, P = 0.63), while the rate of Grade-B fistula significantly increased (m = +1.40, P < 0.01). Fistula Risk Scores were similar between grade B and C POPFs (high risk: 34.9% versus 31.2%, P = 0.21). Associated morbidity was increased with grade C POPF, including delayed gastric emptying, organ space infections, wound dehiscence, respiratory complications, renal complications, myocardial infarction, and bleeding. On multivariate logistic regression, diabetes mellitus (odds ratio: 1.41 95% confidence interval: 1.06-1.87, P = 0.02) was associated with grade C POPF. CONCLUSIONS: This study represents the largest contemporary series evaluating grade C POPFs. Of those suffering CR POPF, the presence of diabetes mellitus was associated with grade C POPF. While modern management has led to grade C POPF in 1% of cases, they remain associated with alarmingly high morbidity and mortality, requiring further mitigation strategies to improve outcomes.

Prince and princesses: The current status of robotic surgery in surgical oncology.

Robotic surgery has experienced a dramatic increase in utilization across general surgery over the last two decades, including in surgical oncology. Although urologists and gynecologists were the first to show that this technology could be utilized in cancer surgery, the robot is now a powerful tool in the treatment of gastrointestinal, hepato-pancreatico-biliary, colorectal, endocrine, and soft tissue malignancies. While long-term outcomes are still pending, short-term outcomes have showed promise for this technologic advancement of cancer surgery.

Lymph node metrics following neoadjuvant therapy to refine patient selection for adjuvant chemotherapy in resected pancreatic cancer: A multi-institutional analysis.

BACKGROUND: In patients with localized pancreatic ductal adenocarcinoma (PDAC) undergoing neoadjuvant therapy (NAT) and resection, selection of adjuvant chemotherapy (AC) is typically guided by high-risk features on histopathologic examination. We evaluated the interaction between post-NAT lymph node metrics and AC receipt on survival. METHODS: Patients who received NAT followed by pancreatectomy (2010-2020) at seven centers were reviewed. Overall survival (OS) in patients receiving AC or not was stratified by lymph node positivity (LNP) or lymph node ratio (LNR) dichotomized at 0.1. Cox models evaluated the independent association between these nodal metrics, AC receipt, and OS. RESULTS: Of 464 patients undergoing NAT and resection, 264 (57%) received AC. Patients selected for AC were younger (median 63 vs. 67 years; p < 0.001), received shorter duration of NAT (2.8 vs. 3.2 months; p = 0.01), had fewer postoperative complications (Clavien-Dindo grade > 3: 1.2% vs. 11.7%; p < 0.001), and lower rates of pathologic complete response (4% vs. 11%; p = 0.01). The median number of nodes evaluated was similar between cohorts (n = 20 in both; p = 0.9). Post-NAT LNP rates were not different, and median LNR was 0.1, in AC and non-AC cohorts. Both LNP (hazard ratio [HR]: 2.1, p < 0.001) and LNR (0 < LNR ≤ 0.1: HR: 1.98, p = 0.002; LNR > 0.1: HR 2.46, p < 0.001) were independently associated with OS on Cox modeling, although receipt of AC was not associated with improved OS (median 30.6 vs. 29.4 months; p = 0.2). In patients with LNR > 0.1, receipt of AC was associated with significantly longer OS compared to non-AC (24 vs. 20 months, respectively; p = 0.04). CONCLUSIONS: LNR following NAT, not simply nodal positivity, may be useful to refine selection of AC in resected PDAC.

Harnessing complexity: Nonlinear optical phenomena in L-shapes, nanocrescents, and split-ring resonators.

We conduct systematic studies of the optical characteristics of plasmonic nanoparticles that exhibit C2v symmetry. In particular, we analyze three distinct geometric configurations: an L-type shape, a crescent, and a split-ring resonator shaped like the Greek letter π. Optical properties are examined using the finite-difference time-domain method. It is demonstrated that all three shapes exhibit two prominent plasmon modes associated with the two axes of symmetry. This is in addition to a wide range of resonances observed at high frequencies corresponding to quadrupole modes and peaks due to sharp corners. Next, to facilitate nonlinear analysis, we employ a semiclassical hydrodynamic model, where the electron pressure term is explicitly accounted for. This model goes beyond the standard Drude description and enables capturing nonlocal and nonlinear effects. Employing this model enables us to rigorously examine the second-order angular resolved nonlinear optical response of these nanoparticles in each of the three configurations. Two pumping regimes are considered, namely, continuous wave (CW) and pulsed excitations. For CW pumping, we explore the properties of the second harmonic generation (SHG). Polarization and angle-resolved SHG spectra are obtained, revealing strong dependence on the nanoparticle geometry and incident wave polarization. The C2v symmetry is shown to play a key role in determining the polarization states and selection rules of the SHG signal. For pulsed excitations, we discuss the phenomenon of broadband terahertz (THz) generation induced by the difference-frequency generation . It is shown that the THz emission spectra exhibit unique features attributed to the plasmonic resonances and symmetry of the nanoparticles. The polarization of the generated THz waves is also examined, revealing interesting patterns tied to the nanoparticle geometry. To gain deeper insight, we propose an analytical theory that agrees very well with the numerical experiments. The theory shows that the physical origin of the THz radiation is the mixing of various frequency components of the fundamental pulse by the second-order nonlinear susceptibility. An expression for the far-field THz intensity is derived in terms of the incident pulse parameters and the nonlinear response tensor of the nanoparticle. The results presented in this work offer new insights into the linear and nonlinear optical properties of nanoparticles with C2v symmetry. The demonstrated strong SHG response and efficient broadband THz generation hold great promise for applications in nonlinear spectroscopy, nanophotonics, and optoelectronics. The proposed theoretical framework also provides a valuable tool for understanding and predicting the nonlinear behavior of other related nanostructures.