Asymmetric Transfer Hydrogenation as a Key Step in the Synthesis of the Phosphonic Acid Analogs of Aminocarboxylic Acids

α-Aminophosphonic acids have a remarkably broad bioactivity spectrum. They can function as highly efficient transition state mimics for a variety of hydrolytic and angiotensin-converting enzymes, which makes them interesting target structures for synthetic chemists. In particular, the phosphonic acid analogs to α-aminocarboxylic acids (Pa AAs) are potent enzyme inhibitors, but many of them are only available by chiral or enzymatic resolution; sometimes only one enantiomer is accessible, and several have never been prepared in enantiopure form at all. Today, a variety of methods to access enantiopure α-aminophosphonic acids is known but none of the reported approaches can be generally applied for the synthesis of Pa AAs. Here we show that the phosphonic acid analogs of many (proteinogenic) α-amino acids become accessible by the catalytic, stereoselective asymmetric transfer hydrogenation (ATH) of α-oxo-phosphonates. The highly enantioenriched (enantiomeric excess (ee) ≥ 98 %) α-hydroxyphosphonates obtained are important pharmaceutical building blocks in themselves and could be easily converted to α-aminophosphonic acids in most studied cases. Even stereoselectively deuterated analogs became easily accessible from the same α-oxo-phosphonates using deuterated formic acid (DCO2 H).

A prospective longitudinal cohort study on risk factors for COVID-19 vaccination failure (RisCoin): methods, procedures and characterization of the cohort

The primary objective of the RisCoin study was to investigate the interplay of genetic, metabolic, and lifestyle factors as well as stress levels on influencing the humoral immune response after at least two COVID-19 vaccinations, primarily with mRNAs, and the risk of SARS-CoV-2 breakthrough infections during follow-up. Here, we describe the study design, procedures, and study population. RisCoin is a prospective, monocentric, longitudinal, observational cohort study. Between October and December 2021, 4515 participants with at least two COVID-19 vaccinations, primarily BNT162b2 and mRNA-1273, were enrolled at the LMU University Hospital of Munich, thereof > 4000 healthcare workers (HCW), 180 patients with inflammatory bowel disease under immunosuppression, and 119 patients with mental disorders. At enrollment, blood and saliva samples were collected to measure anti-SARS-CoV-2 antibodies, their neutralizing capacity against Omicron-BA.1, stress markers, metabolomics, and genetics. To ensure the confidential handling of sensitive data of study participants, we developed a data protection concept and a mobile application for two-way communication. The application allowed continuous data reporting, including breakthrough infections by the participants, despite irreversible anonymization. Up to 1500 participants attended follow-up visits every two to six months after enrollment. The study gathered comprehensive data and bio-samples of a large representative HCW cohort and two patient groups allowing analyses of complex interactions. Our data protection concept combined with the mobile application proves the feasibility of longitudinal assessment of anonymized participants. Our concept may serve as a blueprint for other studies handling sensitive data on HCW.

Automated sample preparation with 6-Aminoquinolyl-N-hydroxysuccinimidyl carbamate and iodoacetamide derivatization reagents for enantioselective liquid chromatography tandem mass spectrometry amino acid analysis

Enantioselective amino acid analysis is gaining increasing importance in pharmaceutical, biomedical and food sciences. While there are many methods available for enantiomer separation of amino acids, the simultaneous analysis of all chiral proteinogenic amino acids by a single method with one column and a single condition is still challenging. Herein, we report an enantioselective high-performance liquid chromatography-tandem mass spectrometry (LC-MS) assay using Chiralpak QN-AX as chiral column. With 6-aminoquinolyl-N-hydrosysuccinimidyl carbamate (AQC) as derivatization reagent, efficient enantioselective separation of D- and L-amino acids using HPLC has become possible. Thiol-containing amino acids like Cys are alkylated prior to AQC-labelling. A protocol for automated sample preparation including both derivatization step and calibrator preparation is presented. For compensating matrix effects, u-13C15N-labelled internal standards (IS) were employed. The method was validated and applied to the enantioselective analysis of amino acids in a bacterial fermentation broth.

Comprehensive reversed-phase×chiral two-dimensional liquid chromatography coupled to quadrupole-time-of-flight tandem mass spectrometry with post-first dimension flow splitting for untargeted enantioselective amino acid analysis

This work describes a comprehensive achiral × chiral two-dimensional liquid chromatography separation for enantioselective amino acid analysis coupled to electrospray ionization-tandem mass spectrometry detection using data-independent acquisition. Flow splitting after the first and second dimension separation was utilized for volumetric flow reduction and for enabling a multi-detector approach (with ultraviolet, fluorescence, charged aerosol, and MS detection), respectively. Derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate provided a chromophore, a fluorophore, and an efficient mass tag for efficient ionization in positive electrospray ionization-mass spectrometry. Chiral columns often have limitations in terms of their chemoselectivity, which may be a problem when complex sample mixtures with structurally related compounds need to be separated. It can be alleviated by a reversed-phase×chiral two-dimensional-liquid chromatography setup, in which the first dimension provides the chemoselectivity and a chiral tandem column constituted of quinine-carbamate derived weak anion-exchanger and zwitterionic ion-exchanger in the second dimension separation of D- and L-amino acid enantiomers. The method was used to control the stereointegrity of the therapeutic peptide octreotide. After hydrolysis, all amino acid constituents were detected with the correct configuration and composition. Some options for flow splitting and integration of destructive detectors in the first dimension separation are outlined.

Comprehensive Online Reversed-Phase × Chiral Two-Dimensional Liquid Chromatography-Mass Spectrometry with Data-Independent Sequential Window Acquisition of All Theoretical Fragment-Ion Spectra-Acquisition for Untargeted Enantioselective Amino Acid Analysis

This work presents an advanced analytical platform for untargeted enantioselective amino acid analysis (eAAA) by comprehensive achiral × chiral 2D-LC hyphenated to ESI-QTOF-MS/MS utilizing data-independent SWATH (sequential window acquisition of all theoretical fragment-ion spectra) technology. The methodology involves N-terminal pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC; AccQ) as retention, selectivity, and MS tag, supporting retention and UV detection in RPLC (¹D), chiral recognition, and thus enantioselectivity by the core-shell tandem column composed of a quinine carbamate weak anion exchanger (QN-AX) and a zwitterionic chiral ion-exchanger (ZWIX(+)) (²D) as well as the ionization efficiency during positive electrospray ionization due to a high proton affinity of the AQC label. Furthermore, the urea-type MS tag gives rise to the generation of AQC-tag characteristic signature fragments in MS². The latter allows the chemoselective mass spectrometric filtering of targeted and untargeted N-derivatized amino acids or related labeled species. The chiral core-shell tandem column provides a complete enantioselective amino acid profile of all proteinogenic amino acids within 1 min, with full baseline separation of all enantiomers, but without resolution of isomeric Ile/allo-Ile (aIle)/Leu, which can be resolved by RPLC. The entire LC × LC separation occurs within a total run time of 60 min (¹D), with the chiral ²D operated in gradient elution mode and a cycle time of 60 s. A strategy to mine the 2D-LC-SWATH data is presented and demonstrated for the qualitative eAAA of two peptide hydrolysate samples of therapeutic peptides containing common and uncommon as well as primary and secondary amino acids. Absolute configuration assignment of amino acids using template matching for all proteinogenic amino acids was made feasible due to method robustness and the inclusion of an isotopically labeled L-[U-¹³C¹⁵N]-AA standard. The quantification performance of this LC × LC-MS/MS assay was also evaluated. Accuracies were acceptable for the majority of AAs enabling AA composition determination in peptide hydrolysates simultaneously with configuration assignment, as exemplified by oxytocin. This methodology represents a step toward truly untargeted 2D enantioselective amino acid analysis and metabolomics.

Curing Cats with Feline Infectious Peritonitis with an Oral Multi-Component Drug Containing GS-441524

Feline infectious peritonitis (FIP) caused by feline coronavirus (FCoV) is a common dis-ease in cats, fatal if untreated, and no effective treatment is currently legally available. The aim of this study was to evaluate efficacy and toxicity of the multi-component drug Xraphconn^® in vitro and as oral treatment in cats with spontaneous FIP by examining survival rate, development of clinical and laboratory parameters, viral loads, anti-FCoV antibodies, and adverse effects. Mass spectrometry and nuclear magnetic resonance identified GS-441524 as an active component of Xraphconn^®. Eighteen cats with FIP were prospectively followed up while being treated orally for 84 days. Values of key parameters on each examination day were compared to values before treatment initiation using linear mixed-effect models. Xraphconn^® displayed high virucidal activity in cell culture. All cats recovered with dramatic improvement of clinical and laboratory parameters and massive reduction in viral loads within the first few days of treatment without serious adverse effects. Oral treatment with Xraphconn^® containing GS-441524 was highly effective for FIP without causing serious adverse effects. This drug is an excellent option for the oral treatment of FIP and should be trialed as potential effective treatment option for other severe coronavirus-associated diseases across species.

Enantioselective multiple heart cutting online two-dimensional liquid chromatography-mass spectrometry of all proteinogenic amino acids with second dimension chiral separations in one-minute time scales on a chiral tandem column

In this work, we present a unique, robust and fully automated analytical platform technology for the enantioselective amino acid analysis using a multiple heart cutting RPLC-enantio/stereoselective HPLC-ESI-QTOF-MS method. This 2D-LC method allows the full enantioselective separation of 20 proteinogenic AAs plus 5 isobaric analogues, namely allo-Threonine (aThr), homoserine (Hse), allo-isoleucine (aIle), tert-Leucine (Tle) and Norleucine (Nle), after pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC; AccQ). This N-terminal AA-derivatization method introduces on the one hand beneficial chromatographic properties for ¹D RP-LC (stronger retention) and ²D chiral separation (better chiral recognition), and on the other hand favorable detection properties with its chromophoric, fluorophoric, and easily ionizable quinoline mass tag. The entire separation occurs within a total 2DLC run time of 45 min, which includes the ¹D-RP run and the 68 s ²D chiral separations of 30 heart-cuts (from the ¹D-RP-run) on a chiral quinine carbamate (core-shell QNAX/fully porous ZWIX) tandem column. This relatively short overall run time was only possible by utilizing the highly efficient "smart peak parking" algorithm for the heart cuts and the resulting optimized analysis order thereof. ¹D retention time precisions of <0.21% RSD were a requirement for the time-based sampling mode and finally led to a robust, fully automated enantioselective amino acid analysis platform. This achiral-chiral 2DLC method was applied for the amino acid stereoconfiguration assignment of three peptides (aureobasidin A, a lipopeptide research sample, and octreotide) using an L-[u-¹³C¹⁵N] labelled internal AA standard mix spiked to each sample. The isotopically labelled L-AA standard allowed an easy and straightforward identification and configuration assignment, as well as the relative quantification of amino acids within the investigated peptides, allowing the direct determination of the number of respective amino acids and their chirality within a peptide.

Acute Metabolic Response in Adults to Toddler Milk Formulas with Alternating Higher and Lower Protein and Fat Contents, a Randomized Cross-Over Trial

Protein intake in early life influences metabolism, weight gain, and later obesity risk. As such, a better understanding of the effects of protein intake on the postprandial metabolism and its dynamics over time may elucidate underlying mechanisms. In a randomized crossover study, we observed fasted adults who consumed two isocaloric toddler milk formulas concentrated as meals of 480 kcal with 67 g of carbohydrates 30 g (HP) or 7 g (LP) protein, and 10 g or 20 g fat, respectively. Anthropometry and body plethysmography were assessed, and blood samples collected at baseline and over five hours. Time-specific concentrations, areas under concentration curves (AUC), and maximum values of metabolites were compared by paired t-tests to examine the effects of protein content of toddler milks on postprandial plasma concentrations of insulin, glucose, branched-chain amino acids (BCAA), urea and triglycerides. Twenty-seven men and women aged 26.7 ± 5.0 years (BMI: 22.2 ± 2.5 kg/m²) (mean ± SD) participated. BCAA AUC, and Cmax values were significantly higher with HP than LP (144,765 ± 21,221 vs. 97,089 ± 14,650 µmol·min/L, p < 0.001; 656 ± 120 vs. 407 ± 66 µmol/L, p < 0.001), as were insulin AUC and Cmax values (6674 ± 3013 vs. 5600 ± 2423 µmol·min/L, p = 0.005; 71 ± 37 vs. 55 ± 28 µmol/L, p = 0.001). Higher glucose, urea, and triglyceride concentrations occurred in the late postprandial phase (≥180 min) with HP. In conclusion, we noted that higher milk protein intake induces increased postprandial BCAA concentrations for at least 5 h and led to higher initial insulin secretion. Gluconeogenesis due to an influx of amino acids and their degradation after HP meal might explain the late effects of protein intake on glucose and insulin.

Discovery of Thanafactin A, a Linear, Proline-Containing Octalipopeptide from Pseudomonas sp. SH-C52, Motivated by Genome Mining

Genome mining of the bacterial strains Pseudomonas sp. SH-C52 and Pseudomonas fluorescens DSM 11579 showed that both strains contained a highly similar gene cluster encoding an octamodular nonribosomal peptide synthetase (NRPS) system which was not associated with a known secondary metabolite. Insertional mutagenesis of an NRPS component followed by comparative profiling led to the discovery of the corresponding novel linear octalipopeptide thanafactin A, which was subsequently isolated and its structure determined by two-dimensional NMR and further spectroscopic and chromatographic methods. In bioassays, thanafactin A exhibited weak protease inhibitory activity and was found to modulate swarming motility in a strain-specific manner.

Multiple Micronutrients, Lutein, and Docosahexaenoic Acid Supplementation during Lactation: A Randomized Controlled Trial

Breastfed infants require an adequate supply of critical nutrients for growth, tissue functions, and health. Recommended intakes for several nutrients are considerably higher in lactating than non-lactating women but are not always met with habitual diets. We report a randomized, double-blind clinical trial in 70 healthy lactating women in Germany evaluating the effects of supplementation with multiple micronutrients, lutein, and docosahexaenoic acid (DHA) compared to placebo on maternal nutrient status and milk composition. The primary endpoint was the effect on the change of human milk DHA content (as a proportion of total milk fatty acids) during 12 weeks of supplementation. Maternal blood and milk biomarkers were measured as secondary endpoints. Supplementation increased maternal milk DHA by 30% compared to a decline in the placebo group. Supplementation also increased maternal blood DHA (17%), eicosapentaenoic acid (4%), 25-OH-vitamin D (24%), vitamin B12 (12%), lutein (4%), and beta carotene (49%), while homocysteine decreased. No significant difference in the number of adverse events was observed between supplementation and placebo groups. In conclusion, multi-micronutrient supplementation was safe and increased maternal blood and milk concentrations of selected nutrients in healthy women.

A population-based resource for intergenerational metabolomics analyses in pregnant women and their children: the Generation R Study

INTRODUCTION

Adverse exposures in early life may predispose children to cardio-metabolic disease in later life. Metabolomics may serve as a valuable tool to disentangle the metabolic adaptations and mechanisms that potentially underlie these associations.

OBJECTIVES

To describe the acquisition, processing and structure of the metabolomics data available in a population-based prospective cohort from early pregnancy onwards and to examine the relationships between metabolite profiles of pregnant women and their children at birth and in childhood.

METHODS

In a subset of 994 mothers-child pairs from a prospective population-based cohort study among pregnant women and their children from Rotterdam, the Netherlands, we used LC-MS/MS to determine concentrations of amino acids, non-esterified fatty acids, phospholipids and carnitines in blood serum collected in early pregnancy, at birth (cord blood), and at child's age 10 years.

RESULTS

Concentrations of diacyl-phosphatidylcholines, acyl-alkyl-phosphatidylcholines, alkyl-lysophosphatidylcholines and sphingomyelines were the highest in early pregnancy, concentrations of amino acids and non-esterified fatty acids were the highest at birth and concentrations of alkyl-lysophosphatidylcholines, free carnitine and acyl-carnitines were the highest at age 10 years. Correlations of individual metabolites between pregnant women and their children at birth and at the age of 10 years were low (range between r = - 0.10 and r = 0.35).

CONCLUSION

Our results suggest that unique metabolic profiles are present among pregnant women, newborns and school aged children, with limited intergenerational correlations between metabolite profiles. These data will form a valuable resource to address the early metabolic origins of cardio-metabolic disease.

Racemization without deamidation: Effect of racemization conditions on 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate tagged amino acids

The aim of this research study was to provide a more thorough understanding of the underlying mechanism and to broaden the application field of the recently introduced racemization method employing the amino acid derivatization tag 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC, AccQ) for heat-induced stereoisomerization of common amino acids as well as uniformly isotopically labeled [U-¹³C¹⁵N]-amino acids. The influence of different buffer types such as sodium borate buffer and sodium carbonate buffer as well as their pH and molarity on the racemization and deamidation of amino acids were investigated. It was found that a 0.4 M borate buffer with a pH of 8.0 +/- 0.2 was the most suitable derivatization as well as racemization buffer to ensure degradation free racemization of deamidation prone compounds such as glutamine. Hereby essential was the in-solution pH measurement before and after derivatization with AQC as well as after heat-induced racemization. This strategy provided further insight at which pH an actual racemization event was observed and when an unwanted deamidation of glutamine to glutamic acid occurred. In addition also the influence of the presence of oxygen during racemization was studied. In this context it was possible to determine ideal oxidation and racemization conditions for the production of scalemic mixtures of chiral isotopically labeled methionine AQC-DL-[U-¹³C¹⁵N]-Met as well as its oxidation products, AQC-DL-[U-¹³C¹⁵N]-Met-O and AQC-DL-[U-¹³C¹⁵N]-Met-O₂. All stereoselective separations were performed on the zwitterionic Chiralpak ZWIX(+) column combined with HPLC-ESI-QTOF-MS analysis in positive ionization mode.

Preparation of Phosphonic Acid Analogues of Proline and Proline Analogues and Their Biological Evaluation as δ1-Pyrroline-5-carboxylate Reductase Inhibitors

Racemic 1-hydroxy-3-butenyl-, 3-chloro-1-hydroxypropyl-, and 3-bromo-1-hydroxypropylphosphonate and the corresponding (S)-enantiomers obtained by lipase-catalyzed resolution of the respective racemic chloroacetates were subjected to functional group manipulations. These comprised ozonolysis, Mitsunobu reactions with hydrazoic acid and N-hydroxyphthalimide, alkylation of hydrazine derivative, removal of phthaloyl group followed by intramolecular substitution, and global deprotection to deliver the racemates and (R)-enantiomers (ee 92-99% by chiral high-performance liquid chromatography) of pyrrolidin-2-yl-, oxazolidin-3-yl-, oxazolidin-5-yl-, pyrazolidin-3-yl-, and 1,2-oxazinan-3-ylphosphonic acids. These phosphonic acids were evaluated as analogues of proline and proline analogues for the ability to inhibit γ-glutamyl kinase, δ¹-pyrroline-5-carboxylate synthetase, and δ¹-pyrroline-5-carboxylate reductase. Only the latter enzyme was inhibited by two of them at concentrations exceeding 1 mM.

A Methylidene Group in the Phosphonic Acid Analogue of Phenylalanine Reverses the Enantiopreference of Binding to Phenylalanine Ammonia-Lyases

Aromatic amino acid ammonia‐lyases and aromatic amino acid 2,3‐aminomutases contain the post‐translationally formed prosthetic 3,5‐dihydro‐4‐methylidene‐5H‐imidazol‐5‐one (MIO) group. MIO enzymes catalyze the stereoselective synthesis of α‐ or β‐amino acid enantiomers, making these chemical processes environmentally friendly and affordable. Characterization of novel inhibitors enables structural understanding of enzyme mechanism and recognizes promising herbicide candidates as well. The present study found that both enantiomers of the aminophosphonic acid analogue of the natural substrate phenylalanine and a novel derivative bearing a methylidene at the β‐position inhibited phenylalanine ammonia‐lyases (PAL), representing MIO enzymes. X‐ray methods unambiguously determined the absolute configuration of all tested enantiomers during their synthesis. Enzyme kinetic measurements revealed the enantiomer of the methylidene‐substituted substrate analogue as being a mirror image relation to the natural l‐phenylalanine as the strongest inhibitor. Isothermal titration calorimetry (ITC) confirmed the binding constants and provided a detailed analysis of the thermodynamic driving forces of ligand binding. Molecular docking suggested that binding of the (R)‐ and (S)‐enantiomers is possible by a mirror image packing.

Self-assembled magnetic bead chains for sensitivity enhancement of microfluidic electrochemical biosensor platforms

In this paper, we present a novel approach to enhance the sensitivity of microfluidic biosensor platforms with self-assembled magnetic bead chains. An adjustable, more than 5-fold sensitivity enhancement is achieved by introducing a magnetic field gradient along a microfluidic channel by means of a soft-magnetic lattice with a 350 μm spacing. The alternating magnetic field induces the self-assembly of the magnetic beads in chains or clusters and thus improves the perfusion and active contact between the analyte and the beads. The soft-magnetic lattices can be applied independent of the channel geometry or chip material to any microfluidic biosensing platform. At the same time, the bead-based approach achieves chip reusability and shortened measurement times. The bead chain properties and the maximum flow velocity for bead retention were validated by optical microscopy in a glass capillary. The magnetic actuation system was successfully validated with a biotin-streptavidin model assay on a low-cost electrochemical microfluidic chip, fabricated by dry-film photoresist technology (DFR). Labelling with glucose oxidase (GOx) permits rapid electrochemical detection of enzymatically produced H2O2.

Can rove beetles (Staphylinidae) be excluded in studies focusing on saproxylic beetles in central European beech forests?

Monitoring saproxylic beetle diversity, though challenging, can help identifying relevant conservation sites or key drivers of forest biodiversity, and assessing the impact of forestry practices on biodiversity. Unfortunately, monitoring species assemblages is costly, mainly due to the time spent on identification. Excluding families which are rich in specimens and species but are difficult to identify is a frequent procedure used in ecological entomology to reduce the identification cost. The Staphylinidae (rove beetle) family is both one of the most frequently excluded and one of the most species-rich saproxylic beetle families. Using a large-scale beetle and environmental dataset from 238 beech stands across Europe, we evaluated the effects of staphylinid exclusion on results in ecological forest studies. Simplified staphylinid-excluded assemblages were found to be relevant surrogates for whole assemblages. The species richness and composition of saproxylic beetle assemblages both with and without staphylinids responded congruently to landscape, climatic and stand gradients, even when the assemblages included a high proportion of staphylinid species. At both local and regional scales, the species richness as well as the species composition of staphylinid-included and staphylinid-excluded assemblages were highly positively correlated. Ranking of sites according to their biodiversity level, which either included or excluded Staphylinidae in species richness, also gave congruent results. From our results, species assemblages omitting staphylinids can be taken as efficient surrogates for complete assemblages in large scale biodiversity monitoring studies.

Prediction of coronary vessel involvement on the basis of atherosclerosis risk factor analysis

The prediction of coronary vessel involvement by means of noninvasive tests is one of the fundamental objectives of preventive cardiology. This review describes the current possibilities of coronary vessel involvement prediction by means of ultrasonographic examination of carotid arteries, analysis of polymorphisms in the genes encoding enzymes responsible for production of nitric oxide and carbon monoxide and assessment of levels of certain proinflammatory cytokines. In the presented work these noninvasive markers are correlated with the extent of coronary vessel involvement as assessed by coronary angiography, intravascular ultrasound and virtual histology (Fig. 5, Ref. 40).

Intracoronary injection of autologous bone marrow-derived mononuclear cells in patients with large anterior acute myocardial infarction and left ventricular dysfunction: a 24- month follow up study

OBJECTIVE AND BACKGROUND

Despite the use of reperfusion therapies, outcomes in patients with large myocardial infarction (MI), late reperfusion and left ventricular (LV) dysfunction are poor. We investigated long-term safety and efficacy of intracoronary injections of autologous bone marrow-derived mononuclear cells (BMNCs).

METHODS

27 patients with anterior MI (age 59±12 years, mean baseline LV ejection fraction (LVEF) 39±5 %), who underwent percutaneous coronary intervention 4-24 hours after the onset of symptoms, were randomly assigned either to intracoronary BMNCs injection (n=17, BMNCs group, out of which 14 underwent long-term follow-up), or to standard therapy (n=10, Control group). The LVEF, the LV end-diastolic and end-systolic volumes (LVEDV, LVESV) were assessed by echocardiography at discharge, Month 4 and 24. Myocardial perfusion was assessed using SPECT at baseline and Month 4.

RESULTS

At 24-month, there was no difference in rates of serious clinical events (36 % vs 50 %, p=0.54). At Month 4 LVEF improved to similar extent in both groups (absolute change +5.8 % vs +7.6 %, p=0.75), with similar infarct size reductions (-10.9 % vs -12.2 %, p=0.47). However, at Month 24, LVEF further improved in BMNCs patients (+12 % vs +8.5 %, p=0.03). This effect resulted from a more pronounced reduction in LVESV (-2.6 ml vs -1.8 ml, p=0.26) and a smaller increase in LVEDV (+16.7 ml vs +17.9 ml, p=0.27) suggesting beneficial long-term effects on LV remodeling.

CONCLUSIONS

BMNCs injections in patients with MI and LV dysfunction were associated with a significant improvement of global LVEF during long term follow-up compared to standard therapy (Tab. 3, Fig. 1, Ref. 50). Full Text in PDF www.elis.sk.

Increase in plasma free haemoglobin during cardiopulmonary bypass in heart valve surgery: assessment of renal dysfunction by RIFLE classification

Heart valve surgery carries a high risk of renal insufficiency as an independent risk factor due to prolonged cardiopulmonary bypass. Multiple causes of cardiopulmonary bypass-associated renal damage have been described, and haemoglobin-induced renal injury is presently being investigated. Forty-three patients scheduled for heart valve surgery (mostly combined) were enrolled in the prospective study. Plasma free haemoglobin (PFH) levels were evaluated by photocolorimetric measurement at the start of procedures (t(0)) and before the end of extracorporeal circulation (t(1)). A statistically significant increase in PFH levels during cardiopulmonary bypass was detected [median values (interquartile range) - t(0): 62.0 (53.4) mg/L, t(1): 320.4 (352.2) mg/L], P < 0.001. A significant regression relationship between the duration of cardiopulmonary bypass and the increased PFH was found (Spearman's correlation coefficient 0.628, P < 0.001). In some elderly patients, the tendency towards a high release of PFH during cardiopulmonary bypass was more pronounced, but the overall association between age and PFH levels was of borderline significance (P = 0.077). The correlation between PFH and post-operative serum creatinine was low and non-significant, but the latter correlated highly with the pre-operative serum creatinine values (Spearman's correlation coefficient reached values of 0.6-0.7, P < 0.001). Patients were classified according to the Risk of renal failure, Injury to the kidney, Failure of kidney function, Loss of kidney function and End-stage renal failure (RIFLE) classification for acute renal dysfunction during post-operative days 1 - 4; the influence of PFH levels at t(1) on the consequent RIFLE classification was not proven (P=0.648), but 4 patients in the Injury category had shown a higher median value of PFH (433.6 mg/L) in comparison with the others (29 patients with no acute renal dysfunction - 313.7 mg/L, 10 patients at Risk - 330.1 mg/L).

Intravascular ultrasound assessment of coronary artery involvement in Fabry disease

AIM

We used intravascular ultrasound (IVUS) to characterize coronary artery involvement in patients with Fabry disease (FD).

METHODS

Nine FD patients (5 women) were matched to 10 control patients (5 women) chosen from our IVUS database. Standard volumetric IVUS analyses were performed along with assessment of plaque echodensity.

RESULTS

Plaques in FD patients were diffuse and hypoechogenic compared with more focal and more echogenic lesions in control patients. Echogenicity of plaques was significantly lower in FD patients (median 30.7 +/- 12.9 vs 55.9 +/- 15.7, p = 0.0052, mean 37.2 +/- 15.6 vs 66.2 +/- 13.3, p = 0.0014). Diffusiveness was assessed as differences between mean and median plaque burden versus the plaque burden in each of the analysed cross-sections. These differences were lower in FD vs controls (5.8 +/- 4.8 vs 8.7 +/- 6.6, p < 0.001 for mean, and 5.8 +/- 4.9 vs 8.8 +/- 7.3, p < 0.001 for median) indicating a more diffuse involvement. The occurrence of lipid cores was significantly higher in FD patients than in controls (2.4 +/- 1.5 vs 1.0 +/- 0.94, p = 0.02).

CONCLUSION

IVUS showed diffuse hypoechogenic plaques in patients with FD. The explanation may be higher lipid content in plaques and accumulation of glycosphingolipid in smooth-muscle and endothelial cells.

Lack of association of iron metabolism and Dupuytren's disease

BACKGROUND

Iron accumulation as seen in genetic haemochromatosis is a major cause of hepatic fibrogenesis. A link between chronic liver disease and Dupuytren's disease (DD) is well established, especially in alcoholics.

AIM

The aim of the present study was to test the hypothesis that iron accumulation might cause fibrosis of the palmar aponeurosis leading to DD.

PATIENTS AND METHODS

We examined iron metabolism, mutations of the HFE gene, serum cholesterol, alcohol consumption, presence of chronic liver disease, diabetes and history of severe manual work in a group of 90 patients who had undergone surgery for a severe form of DD. The tissue removed during surgery was histologically examined to confirm the diagnosis of DD. For a control group, we used 33 healthy subjects with similar profiles.

RESULTS

The DD group consisted of 82 men and 8 women. Chronic liver disease was found in 27% of DD patients, compared with 6.1% of control subjects (P = 0.013). A history of hand traumatization was present in 33% of DD patients vs. 15% of control subjects (P = 0.048). Excessive alcohol consumption was present in 35.5% of DD patients compared with 15.1% of controls (P = 0.029). None of the other tested parameters, including the prevalence of HFE gene mutations, showed a significant difference between the two groups.

CONCLUSIONS

Iron accumulation does not play a major role in the pathogenesis of DD. However, sex, age, manual labour and alcohol consumption are risk factors for progression of DD. We observed a high incidence of chronic liver disease in patients with DD.

The ubiquitin ligase SCF(Grr1) is required for Gal2p degradation in the yeast Saccharomyces cerevisiae

F-box proteins represent the substrate-specificity determinants of the SCF ubiquitin ligase complex. We previously reported that the F-box protein Grr1p is one of the proteins involved in the transmission of glucose-generated signal for proteolysis of the galactose transporter Gal2p and fructose-1,6-bisphosphatase. In this study, we show that the other components of SCF(Grr1), including Skp1, Rbx1p, and the ubiquitin-conjugating enzyme Cdc34, are also necessary for glucose-induced Gal2p degradation. This suggests that transmission of the glucose signal involves an SCF(Grr1)-mediated ubiquitination step. However, almost superimposable ubiquitination patterns of Gal2p observed in wild-type and grr1Delta mutant cells imply that Gal2p is not the primary target of SCF(Grr1) ubiquitin ligase. In addition, we demonstrate here that glucose-induced Gal2p proteolysis is a cell-cycle-independent event.

[Primary biliary cirrhosis--specific anti-mitochondrial antibodies]

Primary biliary cirrhosis is a chronic liver disease, characterized by the destruction of the epithelial cells of the sublobular, interlobular and septal bile ducts and with the development of cirrhosis. The presence of anti-mitochondrial antibodies against the subunits of mitochondrial 2-oxoacids dehydrogenases is characteristic for patients with primary biliary cirrhosis. The aim of this work was to study the effect of anti-mitochondrial antibodies upon activity of the isolated mitochondrial pyruvate dehydrogenase complex after the incubation with serum from patients with primary biliary cirrhosis.

GROUP OF PATIENTS AND METHODS

The activity of the purified bovine pyruvate dehydrogenase complex was studied spectrophotometrically in presence of the serum (1: 1000) from five patients with primary biliary cirrhosis and from ten disease free controls.

RESULTS

The activity of the pyruvate dehydrogenase was decreased after incubation with the serum from patients with primary biliary cirrhosis. No similar inhibitory effect was found after incubation with serum from controls.

DISCUSSION

The inhibitory effect of the anti-mitochondrial antibodies upon activity of pyruvate dehydrogenase may broaden the spectrum of diagnostic methods in patients with primary biliary cirrhosis. Further investigations are necessary to assess the possible application of this method for monitoring of changes during the course of the disease and for assignation of the disease prognosis.

Investigations on the chromatographic behavior of hybrid reversed-phase materials containing electron donor–acceptor systems

The chromatographic behavior of three naphthalimide-type stationary phases were elucidated in terms of hydrophobic, silanophilic and pi-pi interaction properties, employing besides common chromatographic column test methods from Engelhardt and Tanaka, also new test mixtures of geometrical and functional aromatic isomers. It was found that the presence of electron donor/acceptor moieties within a reversed phase system did not only increase the overall retention times for aromatic solutes, but also lead to an enhanced shape selectivity of the hybrid stationary phase. In this context, shape discrimination is primarily based on the number of accessible pi-electrons for pi-pi interaction with the embedded electron deficient ligand moieties. The most outstanding results were obtained for the 1,4,5,8-naphthalenediimidic selector with its horizontal arrangement on the silica surface, which enables a direct face-to-face pi-pi interaction with aromatic solutes, with only little hydrophobic contribution.

Investigations on the chromatographic behavior of hybrid reversed-phase materials containing electron donor–acceptor systems

The influence of sulfur-aromatic interactions on the chromatographic separation behavior of hybrid RP phases, containing thiol-groups and/or embedded sulfide-groups (S-RP) has been investigated. To allow a precise outline of this new interaction mode, a wide variety of S-RP phases with different alkyl chain length, with and without residual thiol-groups and silanol-endcapping were prepared and tested in comparison to some conventional monomerical as well as polymerical n-alkyl type RP phases. The solute test sets employed in this study comprised the classical chromatographic column tests from Engelhardt and Tanaka as well as test assemblies containing polycyclic aromatic hydrocarbons, stilbene-based cis/trans isomers and functional isomers of benzene. In general, a pronounced strong planar recognition ability as well as a strong increase in the retention for aromatic compounds have been noticed. It was furthermore found that not only the sulfur atom incorporated into the alkyl chain, but also the residual thiol-groups of the 3-propylthiol silica backbone contribute to the overall retention behavior of these novel S-RP type phases.

Glucose-induced monoubiquitination of the Saccharomyces cerevisiae galactose transporter is sufficient to signal its internalization

In Saccharomyces cerevisiae, the addition of glucose to cells growing on galactose induces internalization of the galactose transporter Gal2p and its subsequent proteolysis in the vacuole. Here we report that the essential step in Gal2p down-regulation is its ubiquitination through the Ubc1p-Ubc4p-Ubc5p triad of ubiquitin-conjugating enzymes and Npi1/Rsp5p ubiquitin-protein ligase. Moreover, Gal2p appears to be stabilized in mutant cells defective in the ubiquitin-hydrolase Npi2p/Doa4p, and the mutant phenotype can be reversed by overexpression of ubiquitin. An analysis of the fate of Gal2p in cells overexpressing wild-type ubiquitin as well as its variants incompetent to form polyubiquitin chains showed that monoubiquitination of Gal2p is sufficient to signal internalization of the protein into the endocytic pathway.

Virtual PCR

We present an algorithm that uses public sequence data to predict PCR products. The algorithm is implemented as a CGI script. Output is compared to real-world PCR.

AVAILABILITY

Perl code and instructions for installation are freely available over the internet at http://www.sci.muni.cz/LMFR/vpcr.html.