Monosaccharide Analysis After One-Pot Derivatization Followed by Reverse-Phase Liquid Chromatography Separation and UV/Vis Detection.

Derivatization of monosaccharides with 1-phenyl-3-methyl-5-pyrazolone (PMP) introduces two chromophores per sugar molecule. Their separation on a superficially porous C18 reverse-phase column, using common liquid chromatography equipment, results in short analysis times (under 20 min) and high sensitivity (limit of quantitation 1 nmol). This method allows for complex monosaccharide mixtures to be separated and quantified using a reasonably simple and safe derivatization procedure.

Determination of Molecular Dimensions of Carbohydrate Polymers (Polysaccharides) by Size Exclusion Chromatography (SEC).

Calibrated size exclusion chromatography (SEC) is a useful tool for the analysis of molecular dimensions of polysaccharides. The calibration takes place with a set of narrow distributed dextran standards and peak position technique. Adapted columns systems and dissolving processes enable for the adequate separation of carbohydrate polymers. Plant-extracted fructan (a homopolymer with low molar mass and excellent water solubility) and mucilage (differently structured, high molar mass heteropolysaccarides that include existing supramolecular structures, and require a long dissolving time) are presented as examples of the versatility of this technique. Since narrow standards similar to the samples (chemically and structurally) are often unavailable, it must be noted that the obtained molar mass values and distributions by this method are only apparent (relative) values, expressed as dextran equivalents.

Functional Genomics for Plant Breeding 3.0.

Functional genomics, as a scientific discipline, has significantly transformed the landscape of plant breeding in recent years [...].

Identification of inulin-responsive bacteria in the gut microbiota via multi-modal activity-based sorting.

Prebiotics are defined as non-digestible dietary components that promote the growth of beneficial gut microorganisms. In many cases, however, this capability is not systematically evaluated. Here, we develop a methodology for determining prebiotic-responsive bacteria using the popular dietary supplement inulin. We first identify microbes with a capacity to bind inulin using mesoporous silica nanoparticles functionalized with inulin. 16S rRNA gene amplicon sequencing of sorted cells revealed that the ability to bind inulin was widespread in the microbiota. We further evaluate which taxa are metabolically stimulated by inulin and find that diverse taxa from the phyla Firmicutes and Actinobacteria respond to inulin, and several isolates of these taxa can degrade inulin. Incubation with another prebiotic, xylooligosaccharides (XOS), in contrast, shows a more robust bifidogenic effect. Interestingly, the Coriobacteriia Eggerthella lenta and Gordonibacter urolithinfaciens are indirectly stimulated by the inulin degradation process, expanding our knowledge of inulin-responsive bacteria.

Neutral and Pectic Heteropolysaccharides Isolated from Opuntia joconostle Mucilage: Composition, Molecular Dimensions and Prebiotic Potential.

Opuntia joconostle is a semi-wild cactus cultivated for its fruit. However, the cladodes are often discarded, wasting the potentially useful mucilage in them. The mucilage is composed primarily of heteropolysaccharides, characterized by their molar mass distribution, monosaccharide composition, structural features (by vibrational spectroscopy, FT IR, and atomic force microscopy, AFM), and fermentability by known saccharolytic commensal members of the gut microbiota. After fractionation with ion exchange chromatography, four polysaccharides were found: one neutral (composed mainly of galactose, arabinose, and xylose) and three acidic, with a galacturonic acid content from 10 to 35%mol. Their average molar masses ranged from 1.8 × 105 to 2.8 × 105 g·mol-1. Distinct structural features such as galactan, arabinan, xylan, and galacturonan motifs were present in the FT IR spectra. The intra- and intermolecular interactions of the polysaccharides, and their effect on the aggregation behavior, were shown by AFM. The composition and structural features of these polysaccharides were reflected in their prebiotic potential. Lactobacilli and Bifidobacteria were not able to utilize them, whereas members of Bacteroidetes showed utilization capacity. The obtained data suggest a high economic potential for this Opuntia species, with potential uses such as animal feed in arid areas, precise prebiotic, and symbiotic formulations, or as the carbon skeleton source in a green refinery. Our methodology can be used to evaluate the saccharides as the phenotype of interest, helping to guide the breeding strategy.

Confounding factors leading to misdiagnosing ventricular tachycardia as supraventricular in the emergency room.

Studies conducted during the last 50 years have proposed electrocardiographic criteria and algorithms to determine if a wide QRS tachycardia is ventricular or supraventricular in origin. Sustained ventricular tachycardia is an uncommon reason for consultation in the emergency room. The latter and the complexity of available electrocardiographic diagnostic criteria and algorithms result in frequent misdiagnoses. Good hemodynamic tolerance of tachycardia in the supine position does not exclude its ventricular origin. Although rare, ventricular tachycardia in patients with and without structural heart disease may show a QRS duration <120 ms. Interruption of tachycardia by coughing, carotid sinus massage, Valsalva maneuver, or following the infusion of adenosine or verapamil should not discard the ventricular origin of the arrhythmia. In patients with regular, uniform, sustained broad QRS tachycardia, the presence of structural heart disease or A-V dissociation strongly suggest its ventricular origin. Occasionally, ventricular tachycardia can present with AV dissociation without this being evident on the 12-lead ECG. Cardiac auscultation, examination of the jugular venous pulse, and arterial pulse palpation provide additional clues for identifying A-V dissociation during tachycardia. This paper does not review the electrocardiographic criteria for categorizing tachycardia as ventricular but rather why emergency physicians misdiagnose these patients.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA).

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Miniseries 2-Septal and paraseptal accessory pathways-Part IV: Inferior paraseptal accessory pathways-lessons from surgical and catheter ablation.

Surgeons and electrophysiologists performing accessory pathway ablation procedures have used the term 'posteroseptal' region. This area, however, is neither septal nor posterior, but paraseptal and inferior; paraseptal because it includes the fibro-adipose tissues filling the pyramidal space and not the muscular septum itself and inferior because it is part of the heart adjacent to the diaphragm. It should properly be described, therefore, as being inferior and paraseptal. Pathways in this region can be ablated at three areas, which we term right inferior, mid-inferior, and left inferior paraseptal. The right- and left inferior paraseptal pathways connect the right and left atrial vestibules with the right and left paraseptal segments of the parietal ventricular walls. The mid-inferior paraseptal pathways take a subepicardial course from the myocardial sleeves surrounding the coronary sinus and its tributaries. Our review addresses the evolution of the anatomical concept of the inferior paraseptal region derived from surgical and catheter ablation procedures. We also highlight the limitations of the 12-lead electrocardiogram in identifying, without catheter electrode mapping, which are the pathways that can be ablated without a coronary sinus, or left heart approach.

Miniseries 2-Septal and paraseptal accessory pathways-Part III: Mid-paraseptal accessory pathways-revisiting bypass tracts crossing the pyramidal space.

The mid-paraseptal region corresponds to the portion of the pyramidal space whose right atrial aspect is known as the triangle of Koch. The superior area of this mid-paraseptal region is also para-Hisian, and is close to the compact atrioventricular node and the His bundle. The inferior sector of the mid-paraseptal area is unrelated to the normal atrioventricular conduction pathways. It is, therefore, a safe zone in which, if necessary, to perform catheter ablation. The middle part of the mid-paraseptal zone may, however, in some patients, house components of the compact atrioventricular node. This suggests the need for adopting a prudent attitude when considering catheter ablation in this area. The inferior extensions of the atrioventricular node, which may represent the substrate for the slow atrioventricular nodal pathway, take their course through the middle, and even the inferior, sectors of the mid-paraseptal region. In this review, we contend that the middle and inferior areas of the mid-paraseptal region correspond to what, in the past, was labelled by most groups as the 'midseptal' zone. We describe the electrocardiographic patterns observed during pre-excitation and orthodromic reciprocating tachycardia in patients with pathways ablated in the middle or inferior sectors of the region. We discuss the modification of the ventriculo-atrial conduction times during tachycardia after the development of bundle branch block aberrancy. We conclude that the so-called 'intermediate septal' pathways, as described in the era of surgical ablation, were insufficiently characterized. They should not be considered the surrogate of the 'midseptal' pathways defined using endocardial catheter electrode mapping.

Miniseries 2-Septal and paraseptal accessory pathways-Part II: Para-Hisian accessory pathways-so-called anteroseptal pathways revisited.

Surgeons, when dividing bypass tracts adjacent to the His bundle, considered them to be 'anteroseptal'. The area was subsequently recognized to be superior and paraseptal, although this description is not entirely accurate anatomically, and conveys little about the potential risk during catheter interventions. We now describe the area as being para-Hisian, and it harbours two types of accessory pathways. The first variant crosses the membranous septum to insert into the muscular ventricular septum without exiting the heart, and hence being truly septal. The second variant inserts distally in the paraseptal components of the supraventricular crest, and consequently is crestal. The site of ventricular insertion determines the electrocardiographic expression of pre-excitation during sinus rhythm, with the two types producing distinct patterns. In both instances, the QRS and the delta wave are positive in leads I, II, and aVF. In crestal pathways, however, the QRS is ≥ 140 ms, and exhibits an rS configuration in V1-2. The delta wave in V1-2 precedes by 20-50 ms the apparent onset of the QRS in I, II, III, and aVF. In the true septal pathways, the QRS complex occupies ∼120 ms, presenting a QS, W-shaped, morphology in V1-2. The delta wave has a simultaneous onset in all leads. Our proposed terminology facilitates the understanding of the electrocardiographic manifestations of both types of para-Hisian pathways during pre-excitation and orthodromic tachycardia, and informs on the level of risk during catheter ablation.

Primary results of the Spanish Cryoballoon Ablation Registry: acute and long-term outcomes of the RECABA study.

Cryoablation is safe and effective for the treatment of atrial fibrillation (AF) in controlled clinical trials, but contemporary real-world usage and outcomes are limited. The Report of the Spanish Cryoballoon Ablation Registry (RECABA) was designed to evaluate acute and 12-month outcomes of cryoballoon ablation for the treatment of AF in Spain. Patients from 27 Spanish centers were prospectively enrolled. Patients were treated with cryoballoon ablation and managed according to standard of care protocols at each center. The primary endpoint was ≥ 30 s freedom from AF at 12-month after a 3-month blanking period. Secondary endpoints included a description of patient characteristics, cryoablation procedural strategy and safety, and predictors of efficacy. In total, 1742 patients (71.4% PAF, 68.8% male, mean age 58.02 ± 10.40 years, 76.1% overweight or obese, CHA2DS2-VASc index 1.40 ± 1.28) were enrolled. Patients received 7.2 ± 2.67 cryo-applications. PV potentials could be detected in 61% of the PVs during ablation, with a mean time to block of 52.9 ± 37.02 s. Acute PVI was observed in 97% of PVs with 75.8% isolated with the first cryo-application. Mean procedural time was 113 ± 41 min. Acute complications occurred in 4.4% of the cases. With follow-up in 1628 patients, AF-free survival was 78.5% (PAF: 80.6% vs PersAF 73.3%; p < 0.001). Left atrium enlargement, female sex, non-PAF, and early recurrence were independent predictors of AF recurrence (p < 0.05). RECABA provides detailed insight into current dosing practices and demonstrates cryoablation is safe and effective in real-world use.ClinicalTrials.gov number: NCT02785991.

Variable Arrangement of the Atrioventricular Conduction Axis Within the Triangle of Koch: Implications for Permanent His Bundle Pacing.

OBJECTIVES: This study sought to describe, in detail, the angiographic, gross macroscopy, and histological dissection of the conduction axis in humans. BACKGROUND: The recent upsurge of interest in specific pacing of the atrioventricular conduction axis has emphasized the need for precise knowledge of the location of the atrial and penetrating components of the atrioventricular conduction axis. METHODS: A total of 41 human hearts were studied by serial histological sectioning and an additional 3 hearts by gross dissection. One of the hearts studied histologically was also dissected to show the location of the conduction axis prior to serial sectioning. The anatomical findings were then compared with the results of angiography undertaken in the catheter laboratory in 60 patients undergoing electrophysiological studies. RESULTS: Marked variation of the location of the transition from atrioventricular conduction axis to the penetrating atrioventricular bundle, or the bundle of His, relative to the landmarks of the triangle of Koch was observed. In just over one-half of both the specimens and the patients, the site of penetration was on the atrial aspect of the hinge of the septal leaflet of the tricuspid valve, with further variation noted relative to the apex of the triangle of Koch. Based on measurements of the histological sections, marked variation in the dimensions of the axis and its adjacency to the right-sided endocardium were also found. In almost three-fifths of hearts, an interventricular component of the fibrous membranous septum was not able to be identified. The significance of these findings to those who seek to perform selective pacing of the atrioventricular conduction axis are discussed. CONCLUSIONS: Marked variability of the location of the conduction axis within the triangle of Koch is reported. In three-fifths of hearts, the interventricular component of the fibrous membranous septum is nonexistent.

Advanced interatrial block: An electrocardiographic marker for stroke recurrence.

The presence of interatrial block (IAB) has been directly related to the appearance of various atrial tachyarrhythmias and therefore could be a risk factor for stroke. The objective of this study is to establish whether the presence of IAB could predict stroke recurrence in patients with a previous episode. METHODS: We included all patients discharged from our hospital in 2011 following treatment for stroke, excluding those of cardioembolic or lacunar etiology. For all patients we analyzed the ECG recordings, determined whether the patient presented cardiovascular risk factors, and determined the presence and type of IAB. An IAB was defined as partial if the P-wave duration was ≥120 ms, and advanced if the duration was ≥120 ms and presented biphasic morphology in the inferior leads. The primary endpoint was the recurrence of stroke and the secondary endpoint was the incidence of atrial tachyarrhythmias after the first episode. RESULTS: A total of 149 patients were identified (80 (71.5-86.0) years, 41% men). After a median follow-up of 3.96 (0.63-5.35) years, 54 deaths (36%) were observed, 27 patients (18%) had experienced stroke recurrence, and 20 (13%) had developed atrial tachyarrhythmias. On multivariate analysis, the presence of advanced IAB [HR: 2.3, 95% CI (1.0-5.5); p = 0.043] and diabetes [HR: 2.5, 95% CI (1.1-5.4); p = 0.018] were significantly associated with stroke recurrence. CONCLUSION: The presence of advanced IAB predicts the recurrence of stroke in patients with a previous episode. Further studies should be performed to investigate possible interventions.

Interactions of dietary fiber bound antioxidants with hydroxycinnamic and hydroxybenzoic acids in aqueous and liposome media.

The interactions between dietary fiber (DF)-bound antioxidants and free antioxidants, with different substitution patterns of -OH and -OCH3 groups on their aromatic rings has been investigated. The activity and efficiency of these interactions were examined with a structural approach. Whole wheat (WW) DF-bound antioxidants and 21 hydroxycinnamic acid/hydroxybenzoic acids (HCA/HBA) were used in the experimental studies. Studies were performed in liposome and aqueous media by monitoring lipid oxidation and scavenging of DPPH radical in the presence of WW-bound antioxidants and HCA/HBA derivatives. Predominantly synergistic interactions were observed in aqueous medium, while both synergistic and antagonistic interactions were seen in liposome medium. Concentrations of HCA/HBA and WW-bound antioxidants in mixtures and their 2-way interactions made significant effect on lipid oxidation and radical scavenging reactions, with some exceptions. HCA/HBA derivatives with 3 ,4 -dihydroxyphenyl substitution acted as strong antioxidants in liposome medium, while the number of -OH groups affected antioxidant activity in aqueous medium.

Comparison of pharmacological treatment alone vs. treatment combined with implantable cardioverter defibrillator therapy in patients older than 75 years.

AIMS: Implantable cardioverter defibrillator (ICD) reduces mortality in selected patients. However, its role in patients older than 75 years is not well established. METHODS AND RESULTS: We performed a retrospective, non-randomized study using a historical cohort from a single centre. Between January 2008 and July 2014, we assessed patients aged ≥75 years with left ventricular ejection fraction ≤ 35%, identifying 385 patients with a Class I or IIa recommendation for ICD implantation. At the decision of the patient or attending cardiologists, 92 patients received an ICD. To avoid potential confounding factors, we used propensity-score matching. Finally, 126 patients were included (63 with ICD). The mean age was 79.1 ± 3.1 years (86.5% male). As compared with the medical therapy group, the ICD patients had a lower percentage of chronic obstructive pulmonary disease (19.0% vs. 38.1%, P < 0.05) and more frequent use of beta-blockers (BBs) (85.7 vs. 70.0%, P < 0.05). Other treatments were otherwise similar in both groups. There were no differences related to age, aetiology, or other co-morbidities. During follow-up (39.2 ± 22.4 months), total mortality was 46.0% and cardiovascular events (death or hospitalization) occurred in 66.7% of the patients. A multivariate analysis revealed that only BB therapy was shown to be an independent protective variable with respect to mortality [hazard ratio 0.4 (0.2-0.7)]. ICD therapy did not reduce overall mortality or the rate of cardiovascular events. CONCLUSIONS: According to our results, the use of ICD, as compared with medical therapy, in patients older than 75 years did not demonstrate any benefit. Well-designed randomized controlled studies in patients older than 75 years are needed to ascertain the value of ICD therapy.

CorVue algorithm efficacy to predict heart failure in real life: Unnecessary and potentially misleading information?

BACKGROUND: Heart failure (HF) hospitalizations have a negative impact on quality of life and imply important costs. Intrathoracic impedance (ITI) variations detected by cardiac devices have been hypothesized to predict HF hospitalizations. Although Optivol™ algorithm (Medtronic, Minneapolis, MN, USA) has been widely studied, CorVue™ algorithm's (St. Jude Medical, St. Paul, MN, USA) long-term efficacy has not been systematically evaluated in a "real-life" cohort. METHODS: CorVue™ was activated in implantable cardioverter defibrillator (ICD)/cardiac resynchronization therapy defibrillator (CRT-D) patients to store information about ITI measures. Clinical events (new episodes of HF requiring treatment and hospitalizations) and CorVue™ data were recorded every 3 months. Appropriate CorVue™ detection for HF was considered if it occurred in the 4 prior weeks to the clinical event. RESULTS: Fifty-three ICD/CRT-D (26 ICD and 27 CRT-D) patients (67 ± 1 years old, 79% male) were included. Device position was subcutaneous in 28 patients. At inclusion, mean left ventricular ejection fraction was 25 ± 7% and 27 patients (51%) were in New York Heart Association class I, 18 (34%) in class II, and eight (15%) in class III. After a mean follow-up of 17 ± 9 months, 105 ITI drops alarms were detected in 32 patients (60%). Only six alarms were appropriate (true positive) and required hospitalization. Eighteen patients (34%) presented 25 clinical episodes (12 hospitalizations and 13 emergency room/ambulatory treatment modifications). Nineteen of these clinical episodes (76%) remained undetected by the CorVue™ (false negative). Sensitivity of CorVue™ resulted in 24%, specificity was 70%, positive predictive value of 6%, and negative predictive value of 93%. CONCLUSIONS: CorVue™ showed a low sensitivity to predict HF events. Therefore, routinely activation of this algorithm could generate misleading information.