Implementation of Society for Cardiovascular Angiography and Interventions classification in patients with cardiogenic shock secondary to acute myocardial infarction in a spanish university hospital.

BACKGROUND: Killip-Kimball classification has been used for estimating death risk in patients suffering acute myocardial infarction (AMI). Killip-Kimball stage IV corresponds to cardiogenic shock. However, the Society for Cardiovascular Angiography and Interventions (SCAI) classification provides a more precise tool to classify patients according to shock severity. The aim of this study was to apply this classification to a cohort of Killip IV patients and to analyze the differences in death risk estimation between the two classifications. METHODS: A single-center retrospective cohort study of 100 consecutive patients hospitalized for "Killip IV AMI" between 2016 and 2023 was performed to reclassify patients according to SCAI stage. RESULTS: Distribution of patients according to SCAI stages was B=4%, C=53%, D=27%, E=16%. Thirty-day mortality increased progressively according to these stages (B=0%, C=11.88%, D=55.56%, E=87.50%; P<0.001). The exclusive use of Killip IV stage overestimated death risk compared to SCAI C (35% vs. 11.88%, P=0.002) and underestimated it compared to SCAI D and E stages (35% vs. 55.56% and 87.50%, P=0.03 and P<0.001, respectively). Age >69 years, creatinine >1.15 mg/dl and advanced SCAI stages (SCAI D and E) were independent predictors of 30-day mortality. Mechanical circulatory support use showed an almost significant benefit in advanced SCAI stages (D and E hazard ratio, 0.45; 95% confidence interval, 0.19-1.06; P=0.058). CONCLUSIONS: SCAI classification showed superior death risk estimation compared to Killip IV. Age, creatinine levels and advanced SCAI stages were independent predictors of 30-day mortality. Mechanical circulatory support could play a beneficial role in advanced SCAI stages.

Detection of Tumor-Associated Autoantibodies in the Sera of Pancreatic Cancer Patients Using Engineered MUC1 Glycopeptide Nanoparticle Probes.

Pancreatic cancer is one of the deadliest cancers worldwide, mainly due to late diagnosis. Therefore, there is an urgent need for novel diagnostic approaches to identify the disease as early as possible. We have developed a diagnostic assay for pancreatic cancer based on the detection of naturally occurring tumor associated autoantibodies against Mucin-1 (MUC1) using engineered glycopeptides on nanoparticle probes. We used a structure-guided approach to develop unnatural glycopeptides as model antigens for tumor-associated MUC1. We designed a collection of 13 glycopeptides to bind either SM3 or 5E5, two monoclonal antibodies with distinct epitopes known to recognize tumor associated MUC1. Glycopeptide binding to SM3 or 5E5 was confirmed by surface plasmon resonance and rationalized by molecular dynamics simulations. These model antigens were conjugated to gold nanoparticles and used in a dot-blot assay to detect autoantibodies in serum samples from pancreatic cancer patients and healthy volunteers. Nanoparticle probes with glycopeptides displaying the SM3 epitope did not have diagnostic potential. Instead, nanoparticle probes displaying glycopeptides with high affinity for 5E5 could discriminate between cancer patients and healthy controls. Remarkably, the best-discriminating probes show significantly better true and false positive rates than the current clinical biomarkers CA19-9 and carcinoembryonic antigen (CEA).

Impact of minimal lumen segmentation uncertainty on patient-specific coronary simulations: A look at FFRCT.

We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography Angiography FFR CT . A total of 14 patient-specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra ± 6 % and inter-operator ± 15 % variations on the segmentation threshold. FFR CT was evaluated in each case by 3D-OD CFD simulations. The findings suggest that the sensitivity of FFR CT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if the FFR CT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluating FFR CT results.

Illuminating a Solvent-Dependent Hierarchy for Aromatic CH/π Complexes with Dynamic Covalent Glyco-Balances.

CH/π interactions are prevalent among aromatic complexes and represent invaluable tools for stabilizing well-defined molecular architectures. Their energy contributions are exceptionally sensitive to various structural and environmental factors, resulting in a context-dependent nature that has led to conflicting findings in the scientific literature. Consequently, a universally accepted hierarchy for aromatic CH/π interactions has remained elusive. Herein, we present a comprehensive experimental investigation of aromatic CH/π complexes, employing a novel approach that involves isotopically labeled glyco-balances generated in situ. This innovative strategy not only allows us to uncover thermodynamic insights but also delves into the often less-accessible domain of kinetic information. Our analyses have yielded more than 180 new free energy values while considering key factors such as solvent properties, the interaction geometry, and the presence and nature of accompanying counterions. Remarkably, the obtained results challenge conventional wisdom regarding the stability order of common aromatic complexes. While it was believed that cationic CH/π interactions held the highest strength, followed by polarized CH/π, nonpolarized CH/π, and finally anionic CH/π interactions, our study reveals that this hierarchy can be subverted depending on the environment. Indeed, the performance of polarized CH/π interactions can match or even outcompete that of cationic CH/π interactions making them a more reliable stabilization strategy across the entire spectrum of solvent polarity. Overall, our results provide valuable guidelines for the selection of optimal interacting partners in every chemical environment, allowing the design of tailored aromatic complexes with applications in supramolecular chemistry, organocatalysis, and/or material sciences.

Genetic Variability Impacts Genotoxic and Transcriptome Responses in the Human Colon after the Consumption of Processed Red Meat Products and Those with Added Phytochemical Extracts.

The PHYTOME study investigated the effect of consuming processed meat products on outcomes related to colorectal cancer risk without testing the impact of genetic variability on these responses. This research aims to elucidate the genetic impact on apparent total N-nitroso compound (ATNC) excretion, colonic DNA adduct formation, ex vivo-induced DNA damage, and gene expression changes in colon biopsies of healthy participants. Through a systematic literature review, candidate polymorphisms were selected and then detected using TaqMan and PCR analysis. The effect of genotype on study outcomes was determined via a linear mixed model and analysis of variance. Machine learning was used to evaluate relative allele importance concerning genotoxic responses, which established a ranking of the most protective alleles and a combination of genotypes (gene scores). Participants were grouped by GSTM1 genotype and differentially expressed genes (DEGs), and overrepresented biological pathways were compared between groups. Stratifying participants by ten relevant genes revealed significant variations in outcome responses. After consumption of processed red meat, variations in NQO1 and COMT impacted responses in ATNC levels (µmol/L) (+9.56 for wildtype vs. heterozygous) and DNA adduct levels (pg/µg DNA) (+1.26 for variant vs. wildtype and +0.43 for variant vs. heterozygous), respectively. After phytochemicals were added to the meat, GSTM1 variation impacted changes in DNA adduct levels (-6.12 for deletion vs. wildtype). The gene scores correlated with these responses and DEGs were identified by GSTM1 genotype. The altered pathways specific to the GSTM1 wildtype group included 'metabolism', 'cell cycle', 'vitamin D receptor', and 'metabolism of water-soluble vitamins and co-factors'. Genotype impacted both the potential genotoxicity of processed red meat and the efficacy of protective phytochemical extracts.

Low mitochondrial DNA copy number in buffy coat DNA of primary open-angle glaucoma patients.

Primary open-angle glaucoma (POAG) is characterized by optic nerve degeneration and irreversible loss of retinal ganglion cells (RGCs). The pathophysiology is not fully understood. Since RGCs have a high energy demand, suboptimal mitochondrial function may put the survival of these neurons at risk. In the present study, we explored whether mtDNA copy number or mtDNA deletions could reveal a mitochondrial component in POAG pathophysiology. Buffy coat DNA was isolated from EDTA blood of age- and sex-matched study groups, namely POAG patients with high intraocular pressure (IOP) at diagnosis (high tension glaucoma: HTG; n = 97), normal tension glaucoma patients (NTG, n = 37), ocular hypertensive controls (n = 9), and cataract controls (without glaucoma; n = 32), all without remarkable comorbidities. The number of mtDNA copies was assessed through qPCR quantification of the mitochondrial D-loop and nuclear B2M gene. Presence of the common 4977 base pair mtDNA deletion was assessed by a highly sensitive breakpoint PCR. Analysis showed that HTG patients had a lower number of mtDNA copies per nuclear DNA than NTG patients (p-value <0.01, Dunn test) and controls (p-value <0.001, Dunn test). The common 4977 base pair mtDNA deletion was not detected in any of the participants. A lower mtDNA copy number in blood of HTG patients suggests a role for a genetically defined, deficient mtDNA replication in the pathology of HTG. This may cause a low number of mtDNA copies in RGCs, which together with aging and high IOP, may lead to mitochondrial dysfunction, and contribute to glaucoma pathology.

Chylothorax in newborns after cardiac surgery: a rare complication?

The aim of this study was to analyze patients diagnosed with chylothorax after congenital heart disease surgery among a cohort of neonatal patients, comparing the evolution, complications, and prognosis after surgery of patients who were and were not diagnosed with chylothorax, and to analyze possible risk factors that may predict the appearance of chylothorax in this population. Retrospective and observational study included all neonates (less than 30 days since birth) who underwent congenital heart disease surgery in a level III neonatal intensive care department. We included infants born between January 2014 and December 2019. We excluded those infants who were born before 34 weeks of gestational age or whose birth weight was less than 1800 g. We also excluded catheter lab procedures and patent ductus arteriosus closure surgeries. Included patients were divided into two groups depending on whether they were diagnosed with chylothorax or not after surgery, and both groups were compared in terms of perinatal-obstetrical information, surgical data, and NICU course after surgery. We included 149 neonates with congenital heart disease surgery. Thirty-one patients (20.8%) developed chylothorax, and in ten patients (32.3%), it was considered large volume chylothorax. Regarding the evolution of these patients, 22 infants responded to general dietetic measures, a catheter procedure was performed in 9, and 5 of them finally required pleurodesis. Cardiopulmonary bypass, median sternotomy, and delayed sternal closure were the surgical variables associated with higher risks of chylothorax. Patients with chylothorax had a longer duration of inotropic support and mechanical ventilation and took longer to reach full enteral feeds. As complications, they had higher rates of cholestasis, catheter-related sepsis, and venous thrombosis. Although there were no differences in neonatal mortality, patients with chylothorax had a higher rate of mortality after the neonatal period. In a multiple linear regression model, thrombosis and cardiopulmonary bypass multiplied by 10.0 and 5.1, respectively, the risk of chylothorax and have an umbilical vein catheter decreases risk. CONCLUSION: We have found a high incidence of chylothorax after neonatal cardiac surgery, which prolongs the average stay and causes significant morbidity and mortality. We suggested that chylothorax could be an underestimated complication of congenital heart disease surgery during the neonatal period. WHAT IS KNOWN: • Acquired chylothorax in the neonatal period usually appears as a complication of congenital heart disease surgery, being the incidence quite variable among the different patient series (2.5-16.8%). The appearance of chylothorax as a complication of a cardiac surgery increases both mortality and morbidity in these patients, which makes it a quality improvement target in the postsurgical management of this population. WHAT IS NEW: •Most of the published studies include pediatric patients of all ages, from newborns to teenagers, and there is a lack of studies focusing on neonatal populations. The main strength of our study is that it reports, to the best of our knowledge, one of the largest series of neonatal patients receiving surgery for congenital heart disease in the first 30 days after birth. We have found a high incidence of chylothorax after cardiac surgery during the neonatal period compared to other studies. We suggested that chylothorax could be an underestimated complication of congenital heart disease surgery during this period of life.

Predicting missing proteomics values using machine learning: Filling the gap using transcriptomics and other biological features.

Proteins are often considered the main biological element in charge of the different functions and structures of a cell. However, proteomics, the global study of all expressed proteins, often performed by mass spectrometry, is limited by its stochastic sampling and can only quantify a limited amount of protein per sample. Transcriptomics, which allows an exhaustive analysis of all expressed transcripts, is often used as a surrogate. However, the transcript level does not present a high level of correlation with the corresponding protein level, notably due to the existence of several post-transcriptional regulatory mechanisms. In this publication, we hypothesize that the missing protein values in proteomics could be predicted using machine learning regression methods, trained with many features extracted from transcriptomics, including known translational regulatory elements such as microRNAs and circular RNAs. After considering different machine learning algorithms applied on two different splitting strategies, we report that random forest can predict proteins in new samples out of transcriptomics data with good accuracy. The proposed pre-processing and model building scripts can be accessed on GitHub: https://github.com/jochotecoa/ml_proteomics.

Supramolecular nanocapsules as two-fold stabilizers of outer-cavity sub-nanometric Ru NPs and inner-cavity ultra-small Ru clusters.

The synthesis of metallic nanoparticles (MNP) with high surface area and controlled shape is of paramount importance to increase their catalytic performance. The detailed growing process of NP is mostly unknown and understanding the specific steps would pave the way for a rational synthesis of the desired MNP. Here we take advantage of the stabilization properties exerted by the tetragonal prismatic supramolecular nanocapsule 8·(BArF)8 to develop a synthetic methodology for sub-nanometric RuNP (0.6-0.7 nm). The catalytic properties of these sub-nanometric nanoparticles were tested on the hydrogenation of styrene, obtaining excellent selectivity for the hydrogenation of the alkene moiety. In addition, the encapsulation of [Ru5] clusters inside the nanocapsule is strikingly observed in most of the experimental conditions, as ascertained by HR-MS. Moreover, a thorough DFT study enlightens the nature of the [Ru5] clusters as tb-Ru5H2(η6-PhH)2(η6-pyz)3 (2) trapped by two arene moieties of the clip, or as tb-Ru5H2(η1-pyz)6(η6-pyz)3 (3) trapped between the two Zn-porphyrin units of the nanocapsule. Both options fulfill the Wade-Mingos counting rules, i.e. 72 CVEs for the closotb. The trapped [Ru5] metallic clusters are proposed to be the first-grown seeds of subsequent formation of the subnanometric RuNP. Moreover, the double role of the nanocapsule in stabilising ∼0.7 nm NPs and also in hosting ultra-small Ru clusters, is unprecedented and may pave the way towards the synthesis of ultra-small metallic clusters for catalytic purposes.

R-ODAF: Omics data analysis framework for regulatory application.

Despite the widespread use of transcriptomics technologies in toxicology research, acceptance of the data by regulatory agencies to support the hazard assessment is still limited. Fundamental issues contributing to this are the lack of reproducibility in transcriptomics data analysis arising from variance in the methods used to generate data and differences in the data processing. While research applications are flexible in the way the data are generated and interpreted, this is not the case for regulatory applications where an unambiguous answer, possibly later subject to legal scrutiny, is required. A reference analysis framework would give greater credibility to the data and allow the practitioners to justify their use of an alternative bioinformatic process by referring to a standard. In this publication, we propose a method called omics data analysis framework for regulatory application (R-ODAF), which has been built as a user-friendly pipeline to analyze raw transcriptomics data from microarray and next-generation sequencing. In the R-ODAF, we also propose additional statistical steps to remove the number of false positives obtained from standard data analysis pipelines for RNA-sequencing. We illustrate the added value of R-ODAF, compared to a standard workflow, using a typical toxicogenomics dataset of hepatocytes exposed to paracetamol.

A Fungal Versatile GH10 Endoxylanase and Its Glycosynthase Variant: Synthesis of Xylooligosaccharides and Glycosides of Bioactive Phenolic Compounds.

The study of endoxylanases as catalysts to valorize hemicellulosic residues and to obtain glycosides with improved properties is a topic of great industrial interest. In this work, a GH10 ß-1,4-endoxylanase (XynSOS), from the ascomycetous fungus Talaromyces amestolkiae, has been heterologously produced in Pichia pastoris, purified, and characterized. rXynSOS is a highly glycosylated monomeric enzyme of 53 kDa that contains a functional CBM1 domain and shows its optimal activity on azurine cross-linked (AZCL)-beechwood xylan at 70 °C and pH 5. Substrate specificity and kinetic studies confirmed its versatility and high affinity for beechwood xylan and wheat arabinoxylan. Moreover, rXynSOS was capable of transglycosylating phenolic compounds, although with low efficiencies. For expanding its synthetic capacity, a glycosynthase variant of rXynSOS was developed by directed mutagenesis, replacing its nucleophile catalytic residue E236 by a glycine (rXynSOS-E236G). This novel glycosynthase was able to synthesize ß-1,4-xylooligosaccharides (XOS) of different lengths (four, six, eight, and ten xylose units), which are known to be emerging prebiotics. rXynSOS-E236G was also much more active than the native enzyme in the glycosylation of a broad range of phenolic compounds with antioxidant properties. The interesting capabilities of rXynSOS and its glycosynthase variant make them promising tools for biotechnological applications.

Traumatic penetrating arteriovenous fistulas: a collective review.

INTRODUCTION: Traumatic penetrating arteriovenous fistulas (AVFs) are very rare. The majority of these injuries occur secondary to penetrating trauma. Objectives of this study: review their incidence, clinical presentation, radiologic identification, management, complications and outcomes. METHODS: A literature search was performed on MEDLINE Complete-Pubmed from 1829-2019. PRISMA guidelines were utilized. Of 305 potentially eligible articles, 201 articles were selected. INCLUSION CRITERIA: patients age ≥ 18, articles with title and abstract in English, AVFs secondary to penetrating trauma, articles which specified vessels involved in AVFs, and those reporting complete information on patient presentation, diagnosis, imaging, surgical and/or endovascular surgical management, and outcomes of penetrating AVF's. EXCLUSION CRITERIA: articles reporting blunt or iatrogenic AVFs, pediatric patients, fistulas used for dialysis and their complications, articles lacking complete information, cranial/spinal AVFs or cardiac AVFs, and duplicate articles. Mechanism of injury (MOI), diagnosis, involved vessels, management and outcomes of patients with AVFs secondary to penetrating trauma were recorded. RESULTS: There were a total of 291 patients with AVFs secondary to penetrating injuries. Mechanism of injury (MOI): stab wounds (SW)-126 (43.3%), Gunshot wounds (GSW)-94 (32.3%), miscellaneous-35 (12%), mechanism unspecified-36 (12.4%). Anatomic area: neck-69 (23.7%) patients, thorax-46 (15.8%), abdomen-87 (30%), upper and lower extremities-89 (30.6%). Most commonly involved vessels-vertebral artery-38 (13%), popliteal vein-32 (11.7%). Angiography was diagnostic-265 patients (91.1%). INTERVENTIONS: Surgical- 202 (59.6%), Endovascular-118 (34.8%). Associated: aneurysms/pseudoaneurysms-129 (44.3%). CONCLUSION: Most AVFs occur secondary to penetrating injuries. Stab wounds account for the majority of these injuries. Most frequently injured vessels are vertebral artery and superficial femoral vein. Surgical interventions are the most common mode of management followed by endovascular surgical techniques.

Aromatic Interactions in Glycochemistry: From Molecular Recognition to Catalysis.

Aromatic platforms are ubiquitous recognition motifs occurring in protein carbohydrate- binding domains (CBDs), RNA receptors and enzymes. They stabilize the glycoside/ receptor complexes by participating in stacking CH/π interactions with either the α- or ß- face of the corresponding pyranose units. In addition, the role played by aromatic units in the stabilization of glycoside cationic transition states has started being recognized in recent years. Extensive studies carried out during the last decade have allowed the dissection of the main contributing forces that stabilize the carbohydrate/aromatic complexes, while helping delineate not only the standing relationship between the glycoside/ aromatic chemical structures and the strength of this interaction but also their potential influence on glycoside reactivity.

Binding-driven reactivity attenuation enables NMR identification of selective drug candidates for nucleic acid targets.

NMR methods, and in particular ligand-based approaches, are among the most robust and reliable alternatives for binding detection and consequently, they have become highly popular in the context of hit identification and drug discovery. However, when dealing with DNA/RNA targets, these techniques face limitations that have precluded widespread application in medicinal chemistry. In order to expand the arsenal of spectroscopic tools for binding detection and to overcome the existing difficulties, herein we explore the scope and limitations of a strategy that makes use of a binding indicator previously unexploited by NMR: the perturbation of the ligand reactivity caused by complex formation. The obtained results indicate that ligand reactivity can be utilised to reveal association processes and identify the best binders within mixtures of significant complexity, providing a conceptually different reactivity-based alternative within NMR screening methods.

Balloon-Expandable versus Self-Expandable Valves in Transcatheter Aortic Valve Implantation: Complications and Outcomes from a Large International Patient Cohort.

BACKGROUND: Both balloon-expandable (BE) and self-expandable (SE) valves for transcatheter aortic valve implantation (TAVI) are broadly used in clinical practice. However, adequately powered randomized controlled trials comparing these two valve designs are lacking. METHODS: The CENTER-study included 12,381 patients undergoing transfemoral TAVI. Patients undergoing TAVI with a BE-valve (n = 4096) were compared to patients undergoing TAVI with an SE-valve (n = 4096) after propensity score matching. Clinical outcomes including one-year mortality and stroke rates were assessed. RESULTS: In the matched population of n = 5410 patients, the mean age was 81 ± 3 years, 60% was female, and the STS-PROM predicted 30-day mortality was 6.2% (IQR 4.0-12.4). One-year mortality was not different between patients treated with BE- or SE-valves (BE: 16.4% vs. SE: 17.0%, Relative Risk 1.04, 95%CI 0.02-1.21, p = 0.57). One-year stroke rates were also comparable (BE: 4.9% vs. SE: 5.3%, RR 1.09, 95%CI 0.86-1.37, p = 0.48). CONCLUSION: This study suggests that one-year mortality and stroke rates were comparable in patients with severe aortic valve stenosis undergoing TAVI with either BE or SE-valves.

Determination of the surface temperature of magnetically heated nanoparticles using a catalytic approach.

Herein we describe a new method for the determination of the surface temperature of magnetically heated nanoparticles in solution using the temperature dependency of the catalytic performances of iron carbide nanoparticles coated with ruthenium (Fe2.2C@Ru) for acetophenone hydrodeoxygenation. A correlation between nanoparticle surface temperature and magnetic field could be established. Very high surface temperatures could be estimated in different solvents, which were also found similar at a given magnetic field and well above some solvent boiling points.

Applications designed to successfully implant in challenging left atrial appendage occlusion cases: a new tool for the interventional cardiologist.

An 85-year-old patient with permanent atrial fibrillation with a DDD pacemaker, and with indication for left atrial appendage occlusion (LAAO). Sent for LAAO due to recurrent gastrointestinal bleedings even on apixaban and with a CHA 2 DS 2 VASc and HAS-BLED scores of 4 and 3 respectively.

Glycosyl Oxocarbenium Ions: Structure, Conformation, Reactivity, and Interactions.

Carbohydrates (glycans, saccharides, and sugars) are essential molecules in all domains of life. Research on glycoscience spans from chemistry to biomedicine, including material science and biotechnology. Access to pure and well-defined complex glycans using synthetic methods depends on the success of the employed glycosylation reaction. In most cases, the mechanism of the glycosylation reaction is believed to involve the oxocarbenium ion. Understanding the structure, conformation, reactivity, and interactions of this glycosyl cation is essential to predict the outcome of the reaction. In this Account, building on our contributions on this topic, we discuss the theoretical and experimental approaches that have been employed to decipher the key features of glycosyl cations, from their structures to their interactions and reactivity.We also highlight that, from a chemical perspective, the glycosylation reaction can be described as a continuum, from unimolecular SN1 with naked oxocarbenium cations as intermediates to bimolecular SN2-type mechanisms, which involve the key role of counterions and donors. All these factors should be considered and are discussed herein. The importance of dissociative mechanisms (involving contact ion pairs, solvent-separated ion pairs, solvent-equilibrated ion pairs) with bimolecular features in most reactions is also highlighted.The role of theoretical calculations to predict the conformation, dynamics, and reactivity of the oxocarbenium ion is also discussed, highlighting the advances in this field that now allow access to the conformational preferences of a variety of oxocarbenium ions and their reactivities under SN1-like conditions.Specifically, the ground-breaking use of superacids to generate these cations is emphasized, since it has permitted characterization of the structure and conformation of a variety of glycosyl oxocarbenium ions in superacid solution by NMR spectroscopy.We also pay special attention to the reactivity of these glycosyl ions, which depends on the conditions, including the counterions, the possible intra- or intermolecular participation of functional groups that may stabilize the cation and the chemical nature of the acceptor, either weak or strong nucleophile. We discuss recent investigations from different experimental perspectives, which identified the involved ionic intermediates, estimating their lifetimes and reactivities and studying their interactions with other molecules. In this context, we also emphasize the relationship between the chemical methods that can be employed to modulate the sensitivity of glycosyl cations and the way in which glycosyl modifying enzymes (glycosyl hydrolases and transferases) build and cleave glycosidic linkages in nature. This comparison provides inspiration on the use of molecules that regulate the stability and reactivity of glycosyl cations.