352 research outputs found
Photocatalyst-free, visible-light-mediated nickel catalyzed carbon–heteroatom cross-couplings
Acridine functionalized covalent organic frameworks (COFs) as photocatalysts for metallaphotocatalytic C–N cross-coupling
Covalent organic frameworks (COFs) are structurally tuneable, porous and crystalline polymers constructed through the covalent attachment of small organic building blocks as elementary units. Using the myriad of such building blocks, a broad spectrum of functionalities has been applied for COF syntheses for broad applications, including heterogeneous catalysis. Herein, we report the synthesis of a new family of porous and crystalline COFs using a novel acridine linker and benzene-1,3,5-tricarbaldehyde derivatives bearing a variable number of hydroxy groups. With the broad absorption in the visible light region the COFs were applied as photocatalysts in metallaphotocatalytic C–N cross coupling. The fully β-ketoenamine linked COF showed the highest activity, due to the increased charge separation upon irradiation. The COF showed good to excellent yields for several aryl bromides, good recyclability and even catalysed the organic transformation in presence of green light as energy source
<sup>18</sup>F-FDG-PET/CT to Detect Pathological Complete Response After Neoadjuvant Treatment in Patients with Cancer of the Esophagus or Gastroesophageal Junction:Accuracy and Long-Term Implications
Purpose : The curative strategy for patients with esophageal cancer without distant metastases consists of esophagectomy with preceding chemo(radio)therapy (CRT). In 10–40% of patients treated with CRT, no viable tumor is detectable in the resection specimen (pathological complete response (pCR)). This study aims to define the clinical outcomes of patients with a pCR and to assess the accuracy of post-CRT FDG-PET/CT in the detection of a pCR. Methods: Four hundred sixty-three patients with cancer of the esophagus or gastroesophageal junction who underwent esophageal resection after CRT between 1994 and 2013 were included. Patients were categorized as pathological complete responders or noncomplete responders. Standardized uptake value (SUV) ratios of 135 post-CRT FDG-PET/CTs were calculated and compared with the pathological findings in the corresponding resection specimens. Results: Of the 463 included patients, 85 (18.4%) patients had a pCR. During follow-up, 25 (29.4%) of these 85 patients developed recurrent disease. Both 5-year disease-free survival (5y-DFS) and 5-year overall survival (5y-OS) were significantly higher in complete responders compared to noncomplete responders (5y-DFS 69.6% vs. 44.2%; P = 0.001 and 5y-OS 66.5% vs. 43.7%; P = 0.001). Not pCR, but only pN0 was identified as an independent predictor of (disease-free) survival. Conclusion: Patients with a pCR have a higher probability of survival compared to noncomplete responders. One third of patients with a pCR do develop recurrent disease, and pCR can therefore not be equated with cure. FDG-PET/CT was inaccurate to predict pCR and therefore cannot be used as a sole diagnostic tool to predict pCR after CRT for esophageal cancer.</p
The impact of performing gastric cancer surgery during holiday periods. A population-based study using Dutch upper gastrointestinal cancer audit (DUCA) data
Existing literature suggests inferior quality of oncologic surgery during holiday periods. This study aimed to investigate the impact of holiday periods on surgical treatment of gastric cancer in the Netherlands. This nationwide study included all gastric cancer patients undergoing potentially curative surgery registered in the Dutch Upper Gastrointestinal Cancer Audit (DUCA). For each patient it was established whether they underwent surgery during or outside the 11 Dutch holiday weeks, based on date and region of surgery. Separate, single-day holidays were not included. Baseline and treatment characteristics were compared using descriptive statistics. Time from diagnosis to treatment and short-term surgical outcomes were compared using multilevel multivariable logistic regression analyses. To prevent bias from recent advancements, analyses were repeated in a recent cohort of patients (2015-2018). Between 2011-2018, 3440 patients were included in the DUCA. Some 555 (16.1%) patients underwent surgery during 11 holiday weeks. There were no differences in patient, tumor and treatment characteristics and time to treatment between holidays and non-holidays. Tumor-positive resection margins (R1/R2 vs R0) occurred more frequent during holidays (aOR:1.47, 95%CI:1.07-2.04). Subgroup analyses in a recent cohort of patients also found higher tumor-positive resection margins (aOR:1.59, 95%CI:1.01-2.43) and higher failure-to-rescue rates (aOR:2.55, 95%CI:1.18-5.49) during holidays. Even though time to treatment and patient, tumor and treatment characteristics were comparable between holidays and non-holidays, tumor-positive resection margin and failure to-rescue rates were higher during holidays. This suggests that steps must be taken to keep specialized and dedicated gastric cancer expertise up to standard during holiday periods. (C)& nbsp;2022 The Author(s). Published by Elsevier Inc.& nbsp;& nbsp
Postoperative intensive care unit stay after minimally invasive esophagectomy shows large hospital variation:Results from the Dutch Upper Gastrointestinal Cancer Audit
Item does not contain fulltextINTRODUCTION: The value of routine intensive care unit (ICU) admission after minimally invasive esophagectomy (MIE) has been questioned. This study aimed to investigate Dutch hospital variation regarding length of direct postoperative ICU stay, and the impact of this hospital variation on short-term surgical outcomes. MATERIALS AND METHODS: Patients registered in the Dutch Upper Gastrointestinal Cancer Audit (DUCA) undergoing curative MIE were included. Length of direct postoperative ICU stay was dichotomized around the national median into short ICU stay ( ≤ 1 day) and long ICU stay ( > 1 day). A case-mix corrected funnel plot based on multivariable logistic regression analyses investigated hospital variation. The impact of this hospital variation on short-term surgical outcomes was investigated using multilevel multivariable logistic regression analyses. RESULTS: Between 2017 and 2019, 2110 patients from 16 hospitals were included. Median length of postoperative ICU stay was 1 day [hospital variation: 0-4]. The percentage of short ICU stay ranged from 0 to 91% among hospitals. Corrected for case-mix, 7 hospitals had statistically significantly higher short ICU stay rates and 6 hospitals had lower rates. ICU readmission, in-hospital/30-day mortality, failure to rescue, postoperative pneumonia, cardiac complications and anastomotic leakage were not associated with hospital variation in length of ICU stay. Total length of hospital stay was significantly shorter in hospitals with relatively short ICU stay. CONCLUSION: This study showed significant hospital variation in postoperative length of ICU stay after MIE. Short ICU stay was associated with shorter overall hospital admission and did not negatively impact short-term surgical outcomes. More selected use of ICU resources could result in a national significant cost reduction
Intraligand charge transfer enables visible-light-mediated nickel-catalyzed cross-coupling reactions
We demonstrate that several visible-light mediated carbon–heteroatom cross-couplings can be carried out using a photoactive NiII precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups (Ni(Czbpy)Cl2). The activation of this precatalyst towards cross-couplings follows a hitherto undisclosed mechanism that is different from previously reported light-responsive nickel complexes that were reported to undergo metal-to-ligand charge transfer. Theoretic and spectroscopic investigations revealed that irradiation of Ni(Czbpy)Cl2 with visible-light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-couplings. The heterogeneous catalyst shows stable performance in a packed-bed flow reactor during a week of continuous operation
Cardiorespiratory comorbidity and postoperative complications following esophagectomy: a European multicenter cohort study
BACKGROUND: The impact of cardiorespiratory comorbidity on operative outcomes after esophagectomy remains controversial. This study investigated the effect of cardiorespiratory comorbidity on postoperative complications for patients treated for esophageal or gastroesophageal junction cancer. PATIENTS AND METHODS: A European multicenter cohort study from five high-volume esophageal cancer centers including patients treated between 2010 and 2017 was conducted. The effect of cardiorespiratory comorbidity and respiratory function upon postoperative outcomes was assessed. RESULTS: In total 1590 patients from five centers were included; 274 (17.2%) had respiratory comorbidity, and 468 (29.4%) had cardiac comorbidity. Respiratory comorbidity was associated with increased risk of overall postoperative complications, anastomotic leak, pulmonary complications, pneumonia, increased Clavien-Dindo score, and critical care and hospital length of stay. After neoadjuvant chemoradiotherapy, respiratory comorbidity was associated with increased risk of anastomotic leak [odds ratio (OR) 1.83, 95% confidence interval (CI) 1.11-3.04], pneumonia (OR 1.65, 95% CI 1.10-2.47), and any pulmonary complication (OR 1.52, 95% CI 1.04-2.22), an effect which was not observed following neoadjuvant chemotherapy or surgery alone. Cardiac comorbidity was associated with increased risk of cardiovascular and pulmonary complications, respiratory failure, and Clavien-Dindo score ≥ IIIa. Among all patients, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio > 70% was associated with reduced risk of overall postoperative complications, cardiovascular complications, atrial fibrillation, pulmonary complications, and pneumonia. CONCLUSIONS: The results of this study suggest that cardiorespiratory comorbidity and impaired pulmonary function are associated with increased risk of postoperative complications after esophagectomy performed in high-volume European centers. Given the observed interaction with neoadjuvant approach, these data indicate a potentially modifiable index of perioperative risk
Nationwide Outcome of Gastrectomy with En-Bloc Partial Pancreatectomy for Gastric Cancer
Background Radical gastrectomy is the cornerstone of the treatment of gastric cancer. For tumors invading the pancreas, en-bloc partial pancreatectomy may be needed for a radical resection. The aim of this study was to evaluate the outcome of gastrectomies with partial pancreatectomy for gastric cancer. Methods Patients who underwent gastrectomy with or without partial pancreatectomy for gastric or gastro-oesophageal junction cancer between 2011 and 2015 were selected from the Dutch Upper GI Cancer Audit (DUCA). Outcomes were resection margin (pR0) and Clavien-Dindo grade >= III postoperative complications and survival. The association between partial pancreatectomy and postoperative complications was analyzed with multivariable logistic regression. Overall survival of patients with partial pancreatectomy was estimated using the Kaplan-Meier method. Results Of 1966 patients that underwent gastrectomy, 55 patients (2.8%) underwent en-bloc partial pancreatectomy. A pR0 resection was achieved in 45 of 55 patients (82% versus 85% in the group without additional resection, P = 0.82). Clavien-Dindo grade = III complications occurred in 21 of 55 patients (38% versus 17%, P <0.001). Median overall survival [95% confidence interval] was 15 [6.8-23.2] months. For patients with and without perioperative systemic therapy, median survival was 20 [12.3-27.7] and 10 [5.7-14.3] months, and for patients with pR0 and pR1 resection, it was 20 [11.8-28.3] and 5 [2.4-7.6] months, respectively. Conclusions Gastrectomy with partial pancreatectomy is not only associated with a pR0 resection rate of 82% but also with increased postoperative morbidity. It should only be performed if a pR0 resection is feasible
European consensus on essential steps of Minimally Invasive Ivor Lewis and McKeown Esophagectomy through Delphi methodology
BACKGROUND: Minimally invasive esophagectomy (MIE) is a complex and technically demanding procedure with a long learning curve, which is associated with increased morbidity and mortality. To master MIE, training in essential steps is crucial. Yet, no consensus on essential steps of MIE is available. The aim of this study was to achieve expert consensus on essential steps in Ivor Lewis and McKeown MIE through Delphi methodology. METHODS: Based on expert opinion and peer-reviewed literature, essential steps were defined for Ivor Lewis (IL) and McKeown (McK) MIE. In a round table discussion, experts finalized the lists of steps and an online Delphi questionnaire was sent to an international expert panel (7 European countries) of minimally invasive upper GI surgeons. Based on replies and comments, steps were adjusted and rephrased and sent in iterative fashion until consensus was achieved. RESULTS: Two Delphi rounds were conducted and response rates were 74% (23 out of 31 experts) for the first and 81% (27 out of 33 experts) for the second round. Consensus was achieved on 106 essential steps for both the IL and McK approach. Cronbach’s alpha in the first round was 0.78 (IL) and 0.78 (McK) and in the second round 0.92 (IL) and 0.88 (McK). CONCLUSIONS: Consensus among European experts was achieved on essential surgical steps for both Ivor Lewis and McKeown minimally invasive esophagectomy. SUPPLEMENTARY INFORMATION: The online version of this article (doi:10.1007/s00464-021-08304-5) contains supplementary material, which is available to authorized users
The association between hospital variation in curative treatment for esophagogastric cancer and health-related quality of life and survival
Background: As previous studies showed significant hospital variation in curative treatment of esophagogastric cancer, this study assesses the association between this variation and overall, cancer-specific and recurrence-free survival, and Health-Related Quality of Life (HRQoL). Methods: Patients diagnosed with potentially curable esophageal or gastric cancer between 2015 and 2018 as registered in the Netherlands Cancer Registry were included. Data on overall survival was available for all patients, data on cancer-specific and recurrence-free survival and HRQoL was available for subgroups. Patients were classified according to diagnosis in hospitals with low, medium or high probability of treatment with curative intent (LP, MP or HP). Multivariable models were used to assess the association between LP, MP and HP hospitals and HRQoL and survival. Results: This study includes 7,199 patients with esophageal, and 2,407 with gastric cancer. Overall and cancer-specific survival was better for patients diagnosed in HP versus LP hospitals for both esophageal (HR = 0.82, 95%CI:0.77–0.88 and HR = 0.82, 95%CI:0.75–0.91, respectively), and gastric cancer (HR = 0.82, 95%CI:0.73–0.92 and HR = 0.74, 95%CI:0.64–0.87, respectively). These differences disappeared after adjustments for treatment. Recurrence-free survival was worse for gastric cancer patients diagnosed in HP hospitals (HR = 1.50, 95%CI:1.14–1.96), which disappeared after adjustment for radicality of surgery. Minor, but no clinically relevant, differences in HRQoL were observed.Conclusions: Patients diagnosed in hospitals with a high probability of treatment with curative intent have a better overall and cancer-specific but not recurrence-free survival, while minor differences in HRQoL were observed.</p
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