[Quality of nephrolithiasis surgical treatment - what is it influenced by?] / Kvalita operacnej liecby nefrolitiázy: co na nu vplýva?

INTRODUCTION: Identifying factors effecting the quality of nephrolithiasis surgical treatment could improve medical care for patients suffering from kidney stone disease. The objective of the article is to identify factors influencing reintervention rate after surgical treatment of kidney stone disease either by percutaneous nephrolitholapaxy or flexible ureterorenoscopy. METHOD: A retrospective study was conducted on 149 patients who underwent a surgery for a kidney stone disease at the Urological department of F.D. Roosevelt hospital Banská Bystrica from January 2015 till June 2015. The cohort included 60 women at average age of 57 (range 28-91) and 89 men at average age of 58 (range 30-92). Patients were treated by percutaneous litholapaxy (67 cases) and flexible ureterorenoscopy (82 cases, including 72 using dusting technique). Factors with potential influence on probability of repeated intervention during following 12 months have been studied and statistically analyzed. For the statistical analysis we used the generalized linear regression framework (GLM Generalized Linear Model) with the stepwise forward modeling approach. RESULTS: Using the significance level of 5% the statistically significant factors affecting the probability of the re-intervention for ipsilateral kidney stone disease are the stone size (p-value 0.0035) and the postoperative stone free status (p-value 0.0418). Other studied factors as demographical data (age, gender), surgical method (percutaneous nephrolitolapaxy or flexible ureterorenoscopy), stone count, postoperative draining system (nefrostomy or JJ stent) did not have any statistically significant impact. CONCLUSION: Patients could benefit from early diagnosis which could lead to earlier identification of smaller stones. Perfect operative technique with intraoperative achievement of stone free status is important to lower the need of repeated intervention.Key words: kidney stone disease - reintervention residual fragments.

Discrimination between pentose oligosaccharides containing D-xylopyranose or L-arabinofuranose as non-reducing terminal residue using fast atom bombardment mass spectrometry.

Collisional-induced dissociation (CID) mass spectra of the [M + H](+) and [M - H](-) ions obtained under fast atom bombardment conditions of a number of methyl glycoside di-, tri- and tetrasaccharides, containing D-xylopyranosyl and/or L-arabinofuranosyl residues at the non-reducing terminus, do not provide information about their ring size. This information could only be obtained from a careful comparison of the intensity ratio of the [M + Na - 90](+) and [M + Na - 104](+) ions ((0,2)X(t)/(1,5)X(t)) in the high-energy CID spectra of the sodium-cationized di-, tri- and probably also tetrasaccharide compounds.

Chemical ionization mass spectra of acetals of beta-D-glycopyranosylnitromethanes

O-Isopropylidene and O-benzylidene acetals of common 2, 6-anhydro-1-deoxy-1-nitroalditols (beta-D-glycopyranosylnitromethanes) derived from D-glucose, D-galactose and D-mannose were studied by chemical ionization mass spectrometry (CIMS) using methane, isobutane, ammonia or pyridine as reaction gas. Production of [M+H](+) adduct ions dominates in the case of methane or isobutane possessing proton affinity values PA = 552 or 683 kJ mol(-1), respectively. The collision-induced dissociation time-of-flight product ion spectra of [M+H](+) ions differ characteristically according the stereochemical arrangement of the pyranoid ring. These differences can be helpful when assigning stereochemical arrangements for the pyranoid ring. The dominant process in ammonia (PA = 853 kJ mol(-1)) CIMS for most of the compounds studied is the production of the cluster ions [M+NH(4)](+). The cluster [M+pyridineH](+) ions are observable only for substances possessing the O-benzylidene group (PA of pyridine = 924 kJ mol(-1)). Copyright 2000 John Wiley & Sons, Ltd.

Electron ionization mass spectra of acetals of beta-D-glycopyranosylnitromethanes

O-Isopropylidene and O-benzylidene acetals of common 2, 6-anhydro-1-deoxy-1-nitroalditols (beta-D-glyco- pyranosylnitromethanes) derived from D-glucose, D-galactose and D-mannose were studied by electron ionization (EI) mass spectrometry. Fragment pathways of the title compounds were studied using accurate mass measurements, collision-induced dissociation, B/E and B2/E measurements of selected ions and mass spectra of O-deuterium-labelled compound. The fragmentation pathways and some differences found among the mass spectra of stereoisomers are discussed. Noteworthy is the splitting off of the (.)NO(2) radical and elimination of acetone from the molecular ions of 4, 6-O-benzylidene-2, 3-O-isopropylidene-beta-D-galactopyranosylnitromethane. This fragmentation route of relatively high abundance was not observed in the case of D-gluco and D-manno analogues. The differences in the EI mass spectra of stereoisomers may help to provide some information serving for the estimation of the stereochemical arrangement of compounds of this type. Copyright 1999 John Wiley & Sons, Ltd.

Stobadine is a potent modulator of endogenous endothelin-1 in human fibroblasts.

Binding of endothelin (ET) peptides to their respective receptors with resulting proliferation of vascular smooth muscle has been implicated in the pathogenesis of arterial hypertension and atherosclerosis. Recently it was hypothesized that endothelin- (ET-1) bound to its two membrane receptors (ET(A) and ET(B)) continues to activate signal transducing proteins in cells. It was also shown that pyridoindole stobadine stabilized lysosomal membranes in myocardium in early ischemia. Therefore we decided to study the effects of stobadine on specific, subtype-selective binding and subsequent degradation of human, synthetic [125I]-ET-1 in human fibroblasts (HF). Our results indicate that stobadine significantly potentiated ET-1 binding by reductive ET(B) selective degradation of ET-1 in HF. Hence, it is very plausible that stobadine may modulate endogenous endothelin and its intracellular mitogenic and chemotactic factors, principally by affecting two presumably related processes, participating in the proliferative and mitogenic response, (1) potentiation of signal trasduction from ET(A) receptors, and (2) subtype-ET(B) selective intracellular processing.

Sodium-cationized oligosaccharides do not appear to undergo 'internal residue loss' rearrangement processes on tandem mass spectrometry.

The phenomenon of 'internal residue loss' of protonated native- and per-O-methylated oligosaccharides has recently been described as occurring on high-energy collision conditions. Awareness of this phenomenon in the mass spectrometric analysis of oligosaccharides is of great importance since the rearrangement ions produced by this process may complicate monosaccharide sequence assignment. In this research, oligosaccharides having N-acetyl-glucosamine residues as the reducing or non-reducing terminal residue have been included in our MS/MS analyses in order to try to better understand the factors that influence 'internal residue loss'. Native and per-O-methylated compounds were submitted to positive and negative MS/MS, selecting protonated, sodium-cationized, or de-protonated pseudomolecular ions as precursors. High- and low-energy collision induced dissociation tandem mass spectrometry experiments were performed using a four sector instrument and a hybrid quadrupole time-of-flight mass spectrometer respectively. The phenomenon of 'internal residue loss' was not observed on either high- or low-energy CID-MS/MS when sodium-cationized precursor ions of either native or per-O-methylated oligosaccharides were examined. Similarly, MS/MS analysis performed in the negative ionization mode also failed to generate ions resulting from 'internal residue loss'. This combination of experiments therefore offers a way to be sure whether ions observed in the tandem mass spectra of protonated native or per-O-methylated oligosaccharides originate from 'internal residue loss' or from direct glycosidic linkage fragmentation.

Liquid secondary ion mass spectrometry of methyl glycosides of oligosaccharides using matrices containing carboxamides.

Intense cluster ions corresponding to proton-bound hetero-dimers of an amide molecule and an oligosaccharide molecule are observed in the liquid secondary ion mass spectra of methyl glycosides of oligoxylans if a solution of an aliphatic carboxamide in glycerol is used as the liquid matrix. These cluster ions are particularly abundant and persist for a long period if urea (U) or thiourea (TU) is used as the matrix additive. In these cases, cluster ions containing more than one molecule of U or TU and two oligosaccharide molecules are also observed. The intense signal due to the proton-bound hetero-dimer between U or TU and the oligosaccharide can be used with advantage for a molecular weight determination. The bonding interactions between a protonated saccharide molecule and a molecule U or TU in the proton-bound hetero-dimers are so strong that the urea molecules remain attached to the fragment ions during the decay of metastable cluster ions and even during collision-induced dissociation. Thus, the mass-analysed ion kinetic energy spectra of these proton-bound hetero-dimers are dominated by abundant cluster ions [Bn+U] and [Ym+U] arising from cleavage of the glycosidic bonds within the oligosaccharides. The collisionally-activated mass spectra of the proton-bound hetero-dimers additionally contain peaks of the free ions Bn and Ym. Therefore, these spectra clearly reflect the arrangement of the monosaccharide residues in the oligosaccharide and can be used conveniently for structural analysis.

Determination of linkage positions in peracetylated (methyl) xylo-oligosaccharides with fast atom bombardment mass spectrometry.

Distinction between the linkage types 1-->2, 1-->3 and 1-->4 of xylobioses can be achieved on the basis of the unimolecular decomposition spectra of the oxonium ions of the per-O-acetylated methyl glycosides. The spectra of the oxonium ions of various unbranched xylotri-, tetra- and pentaoses allow determination of the linkage position between the xylose residues. This indicates that in unbranched peracetylated xylo-oligosaccharides the linkage between the xylose residues at the non-reducing end can be determined.

Positional identification of fluorine in methyl per-O-acetyl-x-deoxy-x-fluoro-alpha-D-hexopyranosides by electron impact and chemical ionisation mass spectrometry.

Fully acetylated methyl x-deoxy-x-fluoro-alpha-D-glucopyranosides have been studied using electron impact and ammonia chemical ionisation mass spectrometry. Mass analysed metastable ion kinetic energy spectroscopy (MIKE), collisional activation (CID), and accelerated voltage scanning have been used to evaluate complete fragmentation schemes. Characteristic differences in the fragmentation of positional isomers were noted on analysis of the spectra, and these make it possible to determine the location of fluorine in the molecules studied. Collisionally activated fragmentation of [M-OCH3]+ ions, produced by electron impact, provides an alternative method for localisation of the fluorine atoms. To the contrary, MIKE and CID spectra of [M + NH4]+ cluster ions produced by chemical ionisation did not afford such structural information.

Identification of in vitro rat metabolites of pentacaine, a carbanilate local anaesthetic, by gas chromatography/mass spectrometry.

Pentacaine, a novel carbanilate local anaesthetic, is extensively metabolized in rat liver microsomes. The major metabolic routes were found to be aromatic ring hydroxylation, hydroxylation of the aliphatic side-chain and carbamate bond hydrolysis. A deuterium-labelled substrate was used to aid the identification. The metabolites were characterized by gas chromatography/electron impact mass spectrometry as methyl and/or trifluoroacetyl derivatives. All identifications were confirmed by synthesis and direct comparison of chromatographic data and mass spectra.

Determination of pentacaine, trans-2-(1-pyrrolidinyl)cyclohexyl-3-pentyloxycarbanilate hydrochloride, in biological samples by gas chromatography/mass spectrometry.

A quantitative and selective method has been developed for the determination of a novel local anaesthetic compound pentacaine, trans-2-(1-pyrrolidinyl)cyclohexyl-3-pentyloxycarbanilate hydrochloride, in biological samples. After ion pair extraction from 1 M HCl into 1,2-dichloroethane, pentacaine and a structurally related internal standard were derivatized to prevent thermal decomposition in the gas chromatograph. An on-column methylation technique with trimethylanilinium hydroxide was used. Determination was performed by gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring. Interferences by endogenous lipophilic constituents were avoided by including an n-hexane wash before the ion pair extraction. This wash step did not reduce the drug recoveries. The method gave linear results over a concentration range of 5-100 ng ml-1 with a coefficient of variation less than 10% at 5 ng pentacaine ml-1. Specimens of plasma, whole blood, urine as well as in vitro preparations such as hepatic microsomes were successfully analysed.

Mass spectrometry of uronic acid derivatives. XI--Structure elucidation by mass spectrometry of aldobiouronic and pseudoaldobiouronic acids and their beta-elimination products as per-o-methyl derivatives.

Electron impact mass spectra of a series of aldobiouronic and pseudoaldobiouronic acid per-O-methyl derivatives and of the corresponding 4,5-unsaturated analogues, found normally among the products of methylation of uronic acid containing disaccharides as a result of methylation accompanying beta-elimination, have been studied. Using labelling experiments, metastable transition measurements and high resolution mass spectrometry, the fragmentation mechanisms of substances of this class have been deduced. Application of the information to the structure elucidation of this type of compound is discussed. It is concluded that from the mass spectra alone it is possible to determine the molecular weight, the cycle masses as well as the mode of linkage between the monomeric units. The appearance potentials of ions formed by cleavage of the glycosidic linkages have also been determined and the energetic differences encountered in the fission of the glycosidic linkages of various types of uronic acid containing oligosaccharides are discussed.