Recurrence and tumor-related death after resection of hepatocellular carcinoma in patients with metabolic syndrome.

Background & Aims: Metabolic syndrome (MS) is a growing epidemic and a risk factor for the development of hepatocellular carcinoma (HCC). This study investigated the long-term outcomes of liver resection (LR) for HCC in patients with MS. Rates, timing, patterns, and treatment of recurrences were investigated, and cancer-specific survivals were assessed. Methods: Between 2001 and 2021, data from 24 clinical centers were collected. Overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival were analyzed as well as recurrence patterns and treatment. The analysis was conducted using a competing-risk framework. The trajectory of the risk of recurrence over time was applied to a competing risk analysis. For post-recurrence survival, death resulting from tumor progression was the primary endpoint, whereas deaths with recurrence relating to other causes were considered as competing events. Results: In total, 813 patients were included in the study. Median OS was 81.4 months (range 28.1-157.0 months), and recurrence occurred in 48.3% of patients, with a median RFS of 39.8 months (range 15.7-174.7 months). Cause-specific hazard of recurrence showed a first peak 6 months (0.027), and a second peak 24 months (0.021) after surgery. The later the recurrence, the higher the chance of receiving curative intent approaches (p = 0.001). Size >5 cm, multiple tumors, microvascular invasion, and cirrhosis were independent predictors of recurrence showing a cause-specific hazard over time. RFS was associated with death for recurrence (hazard ratio: 0.985, 95% CI: 0.977-0.995; p = 0.002). Conclusions: Patients with MS undergoing LR for HCC have good long-term survival. Recurrence occurs in 48% of patients with a double-peak incidence and time-specific hazards depending on tumor-related factors and underlying disease. The timing of recurrence significantly impacts survival. Surveillance after resection should be adjusted over time depending on risk factors. Impact and implications: Metabolic syndrome (MS) is a growing epidemic and a significant risk factor for the development of hepatocellular carcinoma (HCC). The present study demonstrated that patients who undergo surgical resection for HCC on MS have a good long-term survival and that recurrence occurs in almost half of the cases with a double peak incidence and time-specific hazards depending on tumor-related factors and underlying liver disease. Also, the timing of recurrence significantly impacts survival. Clinicians should therefore adjust follow-up after surgery accordingly, considering timing of recurrence and specific risk factors. Also, the results of the present study might help design future trials on the use of adjuvant therapy following resection.

Minimally Invasive Versus Open Liver Resections for Hepatocellular Carcinoma in Patients With Metabolic Syndrome.

OBJECTIVE: To compare minimally invasive (MILR) and open liver resections (OLRs) for hepatocellular carcinoma (HCC) in patients with metabolic syndrome (MS). BACKGROUND: Liver resections for HCC on MS are associated with high perioperative morbidity and mortality. No data on the minimally invasive approach in this setting exist. MATERIAL AND METHODS: A multicenter study involving 24 institutions was conducted. Propensity scores were calculated, and inverse probability weighting was used to weight comparisons. Short-term and long-term outcomes were investigated. RESULTS: A total of 996 patients were included: 580 in OLR and 416 in MILR. After weighing, groups were well matched. Blood loss was similar between groups (OLR 275.9±3.1 vs MILR 226±4.0, P =0.146). There were no significant differences in 90-day morbidity (38.9% vs 31.9% OLRs and MILRs, P =0.08) and mortality (2.4% vs 2.2% OLRs and MILRs, P =0.84). MILRs were associated with lower rates of major complications (9.3% vs 15.3%, P =0.015), posthepatectomy liver failure (0.6% vs 4.3%, P =0.008), and bile leaks (2.2% vs 6.4%, P =0.003); ascites was significantly lower at postoperative day 1 (2.7% vs 8.1%, P =0.002) and day 3 (3.1% vs 11.4%, P <0.001); hospital stay was significantly shorter (5.8±1.9 vs 7.5±1.7, P <0.001). There was no significant difference in overall survival and disease-free survival. CONCLUSIONS: MILR for HCC on MS is associated with equivalent perioperative and oncological outcomes to OLRs. Fewer major complications, posthepatectomy liver failures, ascites, and bile leaks can be obtained, with a shorter hospital stay. The combination of lower short-term severe morbidity and equivalent oncologic outcomes favor MILR for MS when feasible.

Model to predict major complications following liver resection for HCC in patients with metabolic syndrome.

BACKGROUND: Metabolic syndrome (MS) is rapidly growing as risk factor for HCC. Liver resection for HCC in patients with MS is associated with increased postoperative risks. There are no data on factors associated with postoperative complications. AIMS: The aim was to identify risk factors and develop and validate a model for postoperative major morbidity after liver resection for HCC in patients with MS, using a large multicentric Western cohort. MATERIALS AND METHODS: The univariable logistic regression analysis was applied to select predictive factors for 90 days major morbidity. The model was built on the multivariable regression and presented as a nomogram. Performance was evaluated by internal validation through the bootstrap method. The predictive discrimination was assessed through the concordance index. RESULTS: A total of 1087 patients were gathered from 24 centers between 2001 and 2021. Four hundred and eighty-four patients (45.2%) were obese. Most liver resections were performed using an open approach (59.1%), and 743 (68.3%) underwent minor hepatectomies. Three hundred and seventy-six patients (34.6%) developed postoperative complications, with 13.8% major morbidity and 2.9% mortality rates. Seven hundred and thirteen patients had complete data and were included in the prediction model. The model identified obesity, diabetes, ischemic heart disease, portal hypertension, open approach, major hepatectomy, and changes in the nontumoral parenchyma as risk factors for major morbidity. The model demonstrated an AUC of 72.8% (95% CI: 67.2%-78.2%) ( https://childb.shinyapps.io/NomogramMajorMorbidity90days/ ). CONCLUSIONS: Patients undergoing liver resection for HCC and MS are at high risk of postoperative major complications and death. Careful patient selection, considering baseline characteristics, liver function, and type of surgery, is key to achieving optimal outcomes.

Domino Insertion-Coupling Synthesis of Solid-State Luminescent Propynylidene Indolones.

The compound class of 3-arylpropynylidene indolones, key intermediates in consecutive three-component syntheses of various indole-based chromophores with peculiar emission characteristics, are readily synthesized by a domino insertion-coupling synthesis with an electronically diverse substitution pattern in moderate to excellent yields. The title compounds are formed in E/Z-ratios from 100:0 to 0:100. Besides structure elucidation by NMR-spectroscopy and X-ray structure analysis, DFT calculations have been employed to rationalize the observed stereoselectivity. The photophysical properties of 3-arylpropynylidene indolones are characterized by intense, tunable, solid-state emission of N-substituted derivatives as quantified for drop-cast films. The electronic ground state structure was corroborated by DFT and TD-DFT calculations, showing that gradient-corrected exchange and correlation PBE (Perdew-Burke-Ernzerhof) functionals can be successfully employed to correctly reproduce the observed absorption characteristics of merocyanine derivatives. The huge Stokes shifts strongly depend on the electronic substitution pattern as supported by Hammett-Taft correlations.

Toward metal complexes that can directionally walk along tracks: controlled stepping of a molecular biped with a palladium(II) foot.

We report on the design, synthesis, and operation of a bimetallic molecular biped on a three-foothold track. The "walker" features a palladium(II) complex "foot" that can be selectively stepped between 4-dimethylaminopyridine and pyridine ligand sites on the track via reversible protonation while the walker remains attached to the track throughout by means of a kinetically inert platinum(II) complex foot. The substitution pattern of the three ligand binding sites, together with the kinetic stability of the metal-ligand coordination bonds, affords the two positional isomers a high degree of metastability, meaning that altering the chemical state of the track does not automatically instigate stepping in the absence of an additional stimulus (heat in the presence of a coordinating solvent). The use of metastable metal complexes for foot-track interactions offers a promising alternative to dynamic covalent chemistry for the design of small-molecule synthetic molecular walkers.

Sequence-specific peptide synthesis by an artificial small-molecule machine.

The ribosome builds proteins by joining together amino acids in an order determined by messenger RNA. Here, we report on the design, synthesis, and operation of an artificial small-molecule machine that travels along a molecular strand, picking up amino acids that block its path, to synthesize a peptide in a sequence-specific manner. The chemical structure is based on a rotaxane, a molecular ring threaded onto a molecular axle. The ring carries a thiolate group that iteratively removes amino acids in order from the strand and transfers them to a peptide-elongation site through native chemical ligation. The synthesis is demonstrated with ~10(18) molecular machines acting in parallel; this process generates milligram quantities of a peptide with a single sequence confirmed by tandem mass spectrometry.

A scalable synthesis of 5,5'-dibromo-2,2'-bipyridine and its stepwise functionalization via Stille couplings.

The synthesis of 5,5'-dibromo-2,2'-bipyridine and 5-bromo-2,2'-bipyridine, useful intermediates for elaboration into more complex ligands through metal-catalyzed coupling reactions, can be efficiently conducted on a multigram scale from inexpensive starting materials. The described procedure is reliably scalable and suitable for the synthesis of tens of grams of 5,5'-dibromo-2,2'-bipyridine. 5-Bromo-2,2'-bipyridine is produced as a minor product. The 5,5'-disubstituted-2,2'-bipyridine motif has excellent coordination properties and is a versatile building block for the synthesis of functional materials (including biodiagnostics, photovoltaics and organic light-emitting diodes) and complex molecular topologies (including catenanes and trefoil and pentafoil knots). The selective stepwise functionalization of 5,5'-dibromo-2,2'-bipyridine by consecutive Stille couplings is therefore illustrated and documented in detail. The synthesis of 5,5'-dibromo-2,2'-bipyridine takes 4-5 d: 1 d to prepare the key intermediate 2,2'-bipyridine dihydrobromide, 3 d for its reaction with bromine in a steel bomb reaction vessel and 8 h to isolate and purify the final product.

Phosphorus-based functional groups as hydrogen bonding templates for rotaxane formation.

We report on the use of the hydrogen bond acceptor properties of some phosphorus-containing functional groups for the assembly of a series of [2]rotaxanes. Phosphinamides, and the homologous thio- and selenophosphinamides, act as hydrogen bond acceptors that, in conjunction with an appropriately positioned amide group on the thread, direct the assembly of amide-based macrocycles around the axle to form rotaxanes in up to 60% yields. Employing solely phosphorus-based functional groups as the hydrogen bond accepting groups on the thread, a bis(phosphinamide) template and a phosphine oxide-phosphinamide template afforded the corresponding rotaxanes in 18 and 15% yields, respectively. X-ray crystallography of the rotaxanes shows the presence of up to four intercomponent hydrogen bonds between the amide groups of the macrocycle and various hydrogen bond accepting groups on the thread, including rare examples of amide-to-phosphinamide, -thiophosphinamide, and -selenophosphinamide groups. With a phosphine oxide-phosphinamide thread, the solid-state structure of the rotaxane is remarkable, featuring no direct intercomponent hydrogen bonds but rather a hydrogen bond network involving water molecules that bridge the H-bonding groups of the macrocycle and thread through bifurcated hydrogen bonds. The incorporation of phosphorus-based functional groups into rotaxanes may prove useful for the development of molecular shuttles in which the macrocycle can be used to hinder or expose binding ligating sites for metal-based catalysts.

Unusual solid-state luminescent push-pull indolones: a general one-pot three-component approach.

In a consecutive three-component cyclocarbopalladation, Sonogashira coupling, Michael addition sequence 4-aminopropenylidene indolones, i.e., terminally fixed push-pull chromophores, are obtained in yields as high as 99%. Most remarkable, however, is the pronounced orange red solid state fluorescence displaying large Stokes shifts of these merocyanines, in particular, since all chromophores are nonfluorescent in solution.

Nitrone [2]rotaxanes: simultaneous chemical protection and electrochemical activation of a functional group.

We report on the use of the hydrogen-bond-accepting properties of neutral nitrone moieties to prepare benzylic amide macrocycle-containing [2]rotaxanes in yields as high as 70%. X-ray crystallography showed the presence of up to four intercomponent hydrogen bonds between the amide groups of the macrocycle and the two nitrone groups of the thread. Dynamic (1)H NMR studies of the rates of macrocycle pirouetting in nonpolar solutions indicated that the amide-nitrone hydrogen bonds are particularly strong (approximately 1.3 and approximately 0.2 kcal mol(-1) stronger than similar amide-ester and amide-amide interactions, respectively). In addition to polarizing the N-O bond through hydrogen bonding, the rotaxane structure affects the chemistry of the nitrone groups in two significant ways: first, the intercomponent hydrogen bonding activates the nitrone groups to electrochemical reduction, a one-electron-reduction of the rotaxane being stabilized by a remarkable 400 mV (8.1 kcal mol(-1)) with respect to the same process in the thread; second, however, encapsulation protects the same functional groups from chemical reduction with an external reagent (and slows electron transfer to and from the electroactive groups in cyclic voltammetry experiments). Mechanical interlocking with a hydrogen-bonding molecular sheath thus provides a route to an encapsulated polarized functional group and radical anions of significant kinetic and thermodynamic stability.

Catalytic alkynone generation by Sonogashira reaction and its application in three-component pyrimidine synthesis.

The Sonogashira alkynylation of acid chlorides can be efficiently conducted in less than an hour by performing the reaction in tetrahydrofuran as a solvent and in the presence of one stoichiometrically necessary equivalent of triethylamine as a base. This approach also opens new avenues for consecutive one-pot multicomponent reactions. As an example, the one-pot three-component pyrimidine synthesis illustrates the versatility of this modified Sonogashira protocol as an entry to diversity-oriented heterocycle synthesis in a one-pot fashion. The protocol can be completed within a few hours.

Dichotomies in microwave-assisted propargyl-isomerization-Claisen domino sequences dependent on base strengths.

Microwave-assisted unimolecular isomerization-Claisen domino reactions of 1,3-di(hetero)aryl propargyl trityl ethers lead, depending on the basicity of the amine, either to the formation of tricyclo[3.2.1.0(2,7)]oct-3-enes (with triethylamine) or to indanes (with DBU). Based upon product analyses and computations, this base dependent dichotomy can be rationalized as a sequel of pericyclic reactions with intermediate protonation and deprotonation.

Synthesis, structure and emission properties of spirocyclic benzofuranones and dihydroindolones: a domino insertion-coupling-isomerization- Diels-Alder approach to rigid fluorophores.

An alkynoyl ortho-iodo phenolester or alkynoyl ortho-iodo anilides and propargyl allyl ethers react under Sonogashira coupling conditions in the sense of an insertion-coupling-isomerization-Diels-Alder hetero domino reaction to furnish (tetrahydroisobenzofuran)-spirobenzofuranones and -spirodihydroindolones in good yields. Many representatives can be crystallized and single crystal structure analyses display steric and electronic substituent effects on the torsional angles of the terminal (hetero)aryl groups and the central cis,trans-butadiene fragment. DFT computations reveal that in the final pericyclic step the Diels-Alder termination is by far thermodynamically and kinetically favored over a possible Claisen rearrangement. Compounds of this new class of spirocyclic compounds possess large Stokes shifts and fluoresce intensively with blue over green to orange colors. As a consequence of the spirocyclic rigidity fluorescence lifetimes and quantum yields are rather high in some cases.

Multi-component syntheses of heterocycles by transition-metal catalysis.

For a long time multi-component syntheses of heterocycles have undeniably been a domain of classical carbonyl condensation chemistry. However, the advent of transition-metal catalysis not only has fertilized strategies in heterocyclic synthesis by uni- and bimolecular transformations but the past decade has also witnessed a rapid development of transition-metal catalysis in new multi-component reactions (MCR). Expectedly, palladium catalyzed processes have received a dominant position, yet, other transition-metal complexes are catching up implying organometallic elementary steps that reach even further than cross-coupling and carbometallation. Besides domino MCRs that are purely based upon organometallic catalysis the sequential and consecutive combination with condensation, addition and cycloaddition steps opens a vast playground for the invention of new sequences in heterocyclic synthesis. This tutorial review outlines the underlying reaction based principles of transition-metal catalysis in multi-component syntheses of heterocycles, summarizes recent developments of palladium catalyzed MCR, and highlights the more recent contributions to MCR based heterocyclic synthesis by virtue of rhodium, ruthenium, and copper catalysis.

Coupling-isomerization-Claisen sequences - mechanistic dichotomies in hetero domino reactions.

A new coupling-isomerization-Claisen domino reaction starting from electron deficient halides and 1-(hetero)aryl propargyl trityl ethers dichotomizes in the concluding steps of the sequence and gives rise to the formation of tricyclo[3.2.1.0(2,7)]oct-3-enes, enones, 1H-isochromenes, or indans as a consequence of minute differences of substituent effects.