Comprehensive Review on Chiral Stationary Phases in Single-Column Simultaneous Chiral-Achiral HPLC Separation Methods.

This comprehensive review explores the utilization of chiral stationary phases (CSPs) in the context of single-column simultaneous chiral-achiral high-performance liquid chromatography (HPLC) separation methods. While CSPs have traditionally been pivotal for enantioselective drug analysis, contemporary CSPs often exhibit notable chemoselective properties. Consequently, there is a discernible trend towards the development of methodologies that enable simultaneous enantio- and chemoselective separations utilizing a single CSP-based chromatographic column.

Enantioseparation and molecular docking study of selected chiral pharmaceuticals on a commercialized phenylcarbamate-β-cyclodextrin column using polar organic mode.

The chiral separation capability of Chiral-CD-Ph column, containing phenylcarbamate-β-cyclodextrin as the chiral selector in polar organic mode was investigated. A total of twenty-five compounds with different structures and acid-base properties were evaluated, and twenty of them were separated using acetonitrile or methanol as eluent. The effects of various chromatographic parameters, such as the type and proportion of organic modifier, flow rate, and column temperature were analyzed in detail in relation to chromatographic performance.

Chiral Discrimination of Mexiletine Enantiomers by Capillary Electrophoresis Using Cyclodextrins as Chiral Selectors and Experimental Design Method Optimization.

Mexiletine (MXL) is a class IB antiarrhythmic agent, acting as a non-selective voltage-gated sodium channel blocker, used in therapy as a racemic mixture ,-MXL hydrochloride. The aim of the current study was the development of a new, fast, and efficient method for the chiral separation of MXL enantiomers using capillary electrophoresis (CE) and cyclodextrins (CDs) as chiral selectors (CSs). After an initial CS screening, using several neutral and charged CDs, at four pH levels, heptakis-2,3,6-tri-O-methyl-β-CD (TM-β-CD), a neutral derivatized CD, was chosen as the optimum CS for the enantioseparation.

The Use of Antibiotics as Chiral Selectors in Capillary Electrophoresis: A Review.

Chirality is becoming an essential issue in modern pharmaceutical research as regulatory agencies emphasize the safety and efficiency of enantiomers in drug development. The development of efficient and reliable chiral separation methods became a necessity in the last 30 years, and capillary electrophoresis (CE), due to its relatively low costs and "green" features, is attracting increased attention. Cyclodextrin (CD) and their derivatives are the most frequently used chiral selectors (CSs) in CE, however, the use of antibiotics as CSs represents an interesting alternative.

Application of Experimental Design Methodologies in the Enantioseparation of Pharmaceuticals by Capillary Electrophoresis: A Review.

Chirality is one of the major issues in pharmaceutical research and industry. Capillary electrophoresis (CE) is an interesting alternative to the more frequently used chromatographic techniques in the enantioseparation of pharmaceuticals, and is used for the determination of enantiomeric ratio, enantiomeric purity, and in pharmacokinetic studies. Traditionally, optimization of CE methods is performed using a univariate one factor at a time (OFAT) approach; however, this strategy does not allow for the evaluation of interactions between experimental factors, which may result in ineffective method development and optimization.

Chiral separation in the class of proton pump inhibitors by chromatographic and electromigration techniques: An overview.

Proton pump inhibitors (PPIs) are benzimidazole-derivative chiral sulfoxides, frequently used in the treatment of gastric hyperacidity-related disorders. Due to their stereoselective metabolism, the eutomeric forms of PPIs can present a more advantageous pharmacokinetic profile by comparison with the distomers or racemates. Moreover, two representatives of the class are used in therapy both as racemates and as pure enantiomers (esomeprazole, dexlansoprazole).

The Use of Dual Cyclodextrin Chiral Selector Systems in the Enantioseparation of Pharmaceuticals by Capillary Electrophoresis: An Overview.

Cyclodextrin (CD) derivatives are the most efficient and frequently used chiral selectors (CSs) in capillary electrophoresis (CE). There are situations when the use of a single CD as CS is not enough to obtain efficient chiral discrimination of the enantiomers; in these cases, sometimes this problem can be resolved using a dual CD system. The use of dual CD systems can often dramatically enhance enantioseparation selectivity and can be applied for the separation of many analytes of pharmaceutical interest for which enantioseparation by CE with another CS systems can be problematic.

Enantioseparation of citalopram enantiomers by capillary electrophoresis: Method development through experimental design and computational modeling.

Citalopram (CIT) is a frequently used modern antidepressant that inhibits selectively serotonin reuptake in the brain. It has a chiral center in its structure and is used in therapy as both racemic mixture and pure enantiomer as its pharmacological effect is almost entirely associated with S-CIT. The aim of this study was the development of a simple and rapid capillary electrophoresis (CE) method for the separation and quantification of CIT enantiomers.

Reversed-phase HPLC enantioseparation of pantoprazole using a teicoplanin aglycone stationary phase-Determination of the enantiomer elution order using HPLC-CD analyses.

A direct HPLC method was developed for the enantioseparation of pantoprazole using macrocyclic glycopeptide-based chiral stationary phases, along with various methods to determine the elution order without isolation of the individual enantiomers. In the preliminary screening, four macrocyclic glycopeptide-based chiral stationary phases containing vancomycin (Chirobiotic V), ristocetin A (Chirobiotic R), teicoplanin (Chirobiotic T), and teicoplanin-aglycone (Chirobiotic TAG) were screened in polar organic and reversed-phase mode. Best results were achieved by using Chirobiotic TAG column and a methanol-water mixture as mobile phase.

Chiral separation of lansoprazole and rabeprazole by capillary electrophoresis using dual cyclodextrin systems.

Novel capillary electrophoresis methods using CDs as chiral selectors were developed and validated for the chiral separation of lansoprazole and rabeprazole, two proton pump inhibitors. Fourteen different neutral and anionic CDs were screened at pH 4 and 7 in the preliminary analysis. Sulfobutyl-ether-β-CD with a degree of substitution of 6.

Analytical methodologies for the determination of ticagrelor.

Ticagrelor is an orally administered platelet aggregation inhibitor with a cyclopentyl-triazolopyrimidine structure; it is a selective reversible P2Y12 receptor antagonist, which prevents P2Y12-mediated and ADP-mediated platelet activation and aggregation. It is used to reduce the rate of cardiovascular death, myocardial infarction and stroke in patients with acute coronary syndrome or history of myocardial infarction. Several analytical methods have been published for the determination of ticagrelor in pharmaceuticals and biological materials by spectrophotometry, high-performance liquid chromatography with ultraviolet detection and liquid chromatography coupled with tandem mass spectrometry.

Simple and choice reaction times are prolonged following extracorporeal circulation: a potential method for the assessment of acute neurocognitive deficit.

Background: Cognitive deficit related to open heart surgery came into the focus of interest according to professional and social expectations. The negative effects on quality of life and the large number of involved patients emphasize the need its investigation.

Material/methods: The bedside measurement of simple and choice reaction times (sRT and cRT) has the objectivity of cortical evoked potential analysis without the need for EEG instrumentation and laboratory.

Stent placement in patients with coronary heart disease decreases plasma levels of the endogenous nitric oxide synthase inhibitor ADMA.

The concentration of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is increased in patients with coronary heart disease (CHD). The potential effect of percutaneous coronary intervention (PCI) with stent placement on ADMA plasma level in CHD patients has not yet been investigated. Concentrations of ADMA, L-arginine, symmetric dimethylarginine (SDMA), and L-ornithine were measured in the plasma of 30 CHD patients 24 h before, and 1 h, 5 days, and 30 days following PCI with bare-metal stent or drug-eluting stent placement (stent group) and in the plasma of 20 patients without CHD who underwent angiography alone (control group).

Functionally opposing roles of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase in the regulation of cardiac contractility.

Background: Extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (p38-MAPK) have been shown to regulate various cellular processes, including cell growth, proliferation, and apoptosis in the heart. However, the function of these signaling pathways in the control of cardiac contractility is unclear. Here, we characterized the contribution of ERK1/2 and p38-MAPK to the inotropic effect of endothelin-1 (ET-1).

[Isn't the heart the source of energy for blood circulation? "The heart doesn't know the basic laws of physics"].

For hundreds of years, universal medical practice has depicted the heart to be the central organ, showing the heart's function as the primary source of energy for blood circulation, paying particular importance to the role of the heart valves. At present the generally accepted paradigm: the main force component of blood circulation is the pressure-gradient generated by the working heart. In serious combined illnesses of heart valves, the function of the valve is almost nonexistent.

[Dislodged Amplatzer occluder in the aorta].

Percutaneous device closure of atrial septal defect (ASD) has merged as an alternative to traditional surgical closure. The authors are presenting the case of a 55-year-old female patient with chest complaints following Amplatzer occluder implantation for closure of secundum type ASD. She had been presented ambulatory at her cardiologist's office 3 days after the discharge from the hospital.

Thienopyridine therapy influences late outcome after coronary stent implantation.

Clinical significance of resistance to aspirin and thienopyridine therapy is poorly defined. The authors aimed to evaluate whether more effective antiplatelet therapy is associated with better outcome in patients on dual-antiplatelet treatment. Using optical aggregometer, maximal platelet aggregation values were measured with induction of adenosine diphosphate, collagen, and adrenaline 30 +/- 5 days after coronary stent implantation in 134 patients.

[Pacemaker in MR: absolute contraindication?].

Due to developments in pacemaker technology, implanted pacemakers do not mean an absolute contraindication for MRI examination. However, there are several aspects of MRI examinations that should be considered for safety reasons in pacemaker patients. Based on literature data and own experiments, the safety protocol of MRI examination in pacemaker-implanted patients is described.

[Vena cava superior syndrome: surgical treatment of the thrombosis of the superior vena cava after implantation of a hemodialysis catheter--a case report and review of the literature].

One of the rare reasons of the non malignant superior vena cava syndrome is the thrombosis of superior vena cava. Obstruction or occlusion of central veins is one of the many complications of the more and more frequently used central venous catheters and pacemaker electrodes. The authors report a case of superior vena cava thrombosis resulting in dialysis catheter insufficiency in case of a young, uraemic, female patient wit Tesio catheter and the surgical treatment of it with the use of cardiopulmonary bypass during the operation.

[The principles of minimal extracorporeal circulation and its uses].

The recently introduced minimal extracorporeal circulation system is a remarkable alternative to the conventional heart-lung machine in several cardiosurgical indications. It consists of a centrifugal pump, an oxygenator, a tip-to-tip heparin coated line set and a modified cell saver application. Due to its closed blood-air interaction-free construction and reduced priming volume, the unfavourable effects of perfusion as haemodilution, inflammatory response, locoregional malperfusion, transfusion needs, can be effectively reduced.

Chronic postinfarction pseudo-pseudoaneurysm diagnosed by cardiac MRI.

Left ventricular pseudo-pseudoaneurysm is an extremely rare complication of myocardial infarction. In this condition the postinfarction rupture of the myocardium is not transmural, but remains circumscribed within the ventricular muscle itself as a cavity joining to the left ventricle through a narrow neck. The differentiation between postinfarction pseudoaneurysms and pseudo-pseudoaneurysms may be very difficult using conventional imaging techniques, such as transthoracic, or transesophageal echocardiography and left ventricular angiography.

Nuclear factor-kappaB signaling contributes to severe, but not moderate, angiotensin II-induced left ventricular remodeling.

Objective: The transcription factor nuclear factor-kappaB (NF-kappaB) has been implicated in cardiomyocyte hypertrophy in vitro as well as in vivo; however, it is unknown if activation of NF-kappaB plays a mandatory role in the hypertrophic process. Here we characterize the importance of NF-kappaB signaling in moderate and severe left ventricular (LV) hypertrophy in rats with chronic pressure overload induced by angiotensin II (Ang II) infusion.

Methods And Results: Electrophoretic mobility shift assay analysis revealed that Ang II infusion (2.

Magnetic resonance studies in management of adult cases with Bland-White-Garland syndrome.

Bland-White-Garland syndrome (BWG) is a rare congenital anomaly that is predominantly discovered in infancy. BWG is characterized by an anomalous origin of the left coronary trunk from the pulmonary artery that produces a coronary steal phenomenon, left-to-right shunt, and thus an abnormal left ventricular perfusion. The latter may induce myocardial necrosis, left ventricular dysfunction and commonly associated with mitral regurgitation.

Involvement of endogenous ouabain-like compound in the cardiac hypertrophic process in vivo.

The Na(+)/K(+)-ATPase inhibitor ouabain has been shown to trigger hypertrophic growth of cultured cardiomyocytes; however, the significance of endogenous ouabain-like compound (OLC) in the hypertrophic process in vivo is unknown. Here we characterized the involvement of OLC in left ventricular (LV) hypertrophy induced by norepinephrine (NE) and angiotensin II (Ang II) infusions in rats. Administration of NE (300 microg/kg/h) via subcutanously implanted osmotic minipumps for 72 h resulted in a significant increase in left ventricular weight to body weight (LVW/BW) ratio (P<0.

Human heart mitochondria do not produce physiologically relevant quantities of nitric oxide.

Previous studies raised the possibility that nitric oxide synthase is present in heart mitochondria (mtNOS) and the existence of such an enzyme became generally accepted. However, original experimental evidence is rather scarce and positive identification of the enzyme is lacking. We aimed to detect an NOS protein in human and mouse heart mitochondria and to measure the level of NO released from the organelles.