On Monotonic Radial Basis Function Networks.

This article deals with monotonicity conditions for radial basis function (RBF) networks. Two architectures of RBF networks are considered-1) unnormalized network with a local character of the basis function and 2) a normalized network where the value of RBF is taken relatively with respect to the others. Different approaches are followed for each of them.

Can the prophylactic administration of tranexamic acid reduce the blood loss after robotic-assisted radical prostatectomy? Robotic Assisted Radical Prostatectomy with tranEXamic acid (RARPEX): study protocol for a randomized controlled trial.

Background: The prophylactic administration of tranexamic acid reduces blood loss during procedures at high risk of perioperative bleeding. Several studies in cardiac surgery and orthopedics confirmed this finding. The aim of this prospective, double-blind, randomized study is to evaluate the effect of tranexamic acid on peri-and postoperative blood loss and on the incidence and severity of complications.

Safety and Efficacy of Using Tranexamic Acid at the Beginning of Robotic-Assisted Radical Prostatectomy in a Double-Blind Prospective Randomized Pilot Study.

Background: The prophylactic administration of tranexamic acid has been shown to be appropriate for procedures with a high risk of perioperative bleeding in cardiac surgery and orthopaedics. In urology the ambiguous results have been reported. Our goal was to evaluate the effect of tranexamic acid administration in robotic-assisted radical prostatectomy (RARP).

Hand-assisted laparoscopic nephrectomy in morbidly obese patients.

Introduction: Prevalence of obesity is 30 % in the Czech Republic and is expected to increase further in the future. This disease complicates surgical procedures but also the postoperative period. The aim of our paper is to present the surgical technique called hand-assisted laparoscopic nephrectomy (HALS), used in surgical management of kidney cancer in morbid obese patients with BMI >40 kg/m2.

Heptafluorobutyl Chloroformate-Based Sample Preparation Protocol for Nonchiral and Chiral Amino Acid Analysis by Gas Chromatography-Mass Spectrometry.

Gas chromatography (GC) is a commonly used technique in amino acid analysis (AAA). However, one of the requirements of the application of GC for AAA is a need for the polar analytes to be converted into their volatile, thermally stable derivatives. In the last two decades, alkyl chloroformates (RCFs) have become attractive derivatization reagents.

Colloid Osmotic Pressure Participates on the Post-transplant Lymphocele Pathogenesis.

The aim of the study was to evaluate the role of colloid osmotic pressure in post-transplant lymphocele pathogenesis. We have analyzed total plasmatic protein and albumin levels, and electrophoresis has been completed in blood samples before transplantation and in days 3 and 14 after transplantation in 50 patients with lymphocele (Lymphocele) and 198 patients without lymphocele (control), respectively. Colloid osmotic pressure (COP) was calculated according to the Hoefs formula.

GC-MS Metabolomic Profiling of Protic Metabolites Following Heptafluorobutyl Chloroformate Mediated Dispersive Liquid Microextraction Sample Preparation Protocol.

A simple analytical workflow is described for gas chromatographic-mass spectrometry (GC-MS)-based metabolomic profiling of protic metabolites, particularly amino-carboxylic species in biological matrices. The sample preparation is carried out directly in aqueous samples and uses simultaneous in situ heptafluorobutyl chloroformate (HFBCF) derivatization and dispersive liquid-liquid microextraction (DLLME), followed by GC-MS analysis in single-ion monitoring (SIM) mode. The protocol involves ten simple pipetting steps and provides quantitative analysis of 132 metabolites by using two internal standards.

Methylation status as a predictor of intravesical Bacillus Calmette-Guérin (BCG) immunotherapy response of high grade non-muscle invasive bladder tumor.

Background And Aims: Genetic and epigenetic alterations play an important role in urothelial cancer pathogenesis. Deeper understanding of these processes could help us achieve better diagnosis and management of this life-threatening disease. The aim of this research was to evaluate the methylation status of selected tumor suppressor genes for predicting BCG response in patients with high grade non-muscle-invasive bladder tumor (NMIBC).

Profiling of urinary amino-carboxylic metabolites by in-situ heptafluorobutyl chloroformate mediated sample preparation and gas chromatography-mass spectrometry.

A novel 1,1,1,2,2,3,3-heptafluorobutyl chloroformate reagent (HFBCF) was examined for in-situ derivatization of amino-carboxylic metabolites in human urine. The arising reaction products exhibit greatly reduced polarity which facilitates combining the derivatization and liquid-liquid microextraction (LLME) from an aqueous urine into an isooctane phase and immediate gas chromatographic-mas spectrometric analysis (GC-MS). The sample preparation protocol is simple, proceeds without an alcohol excess and provides cleaner extracts than other urinary GC-MS based methods.

[Tissue cyanoacrylate glue in partial nephrectomy - our own experience and assessment].

Introduction: The effect of cyanoacrylate glues was repeatedly evaluated in resections of liver, lungs and others organs, but minimally in kidney resection. The aim of our study was to evaluate the use of cyanoacrylate tissue glue in open and laparoscopic partial nephrectomy.

Method: We evaluated a cohort of 32 patients who underwent partial nephrectomy with treatment of the resected area using cyanoacrylate glue.

Urological surgery in elderly patients: results and complications.

Purpose: Owing to the large aging population, a growing number of elderly patients are undergoing surgical treatment. Surgical procedures in elderly patients are associated with a higher risk of complications. The aim of this study was to evaluate the efficacy and safety of urological surgeries in old patients.

A new method for immediate derivatization of hydroxyl groups by fluoroalkyl chloroformates and its application for the determination of sterols and tocopherols in human serum and amniotic fluid by gas chromatography-mass spectrometry.

A new method has been described for efficient derivatization of secondary alicyclic hydroxyl groups in steroids by alkyl chloroformates (RCFs). Cholesterol, an essential human sterol and a steroid precursor in eukaryotic cells, was used as a model for treatment with various RCFs in an aqueous and non-aqueous environment. While the cholesterol hydroxyl group did not react completely with any of the tested RCFs reagents in the former case, trifluoroethyl chloroformate (TFECF) or heptafluorobutyl chloroformate (HFBCF) fully converts cholesterol and related metabolites into the corresponding mixed carbonates under anhydrous conditions in seconds.

Survey of several methods deproteinizing human plasma before and within the chloroformate-mediated treatment of amino/carboxylic acids quantitated by gas chromatography.

Trichloroacetic acid, perchloric acid, phosphotungstic acid, acetonitrile, methanol and some other organic solvents were evaluated for their ability to provide protein and lipid-free plasma supernatants. The residual proteins, total cholesterol and triacylglycerols were assayed in the supernatant on a Beckman Analyzer instrument. The free cholesterol and the neutral lipids were further analyzed by means of high-temperature GC analysis.

In situ derivatization-liquid liquid extraction as a sample preparation strategy for the determination of urinary biomarker prolyl-4-hydroxyproline by liquid chromatography-tandem mass spectrometry.

Polar analytes that possess protic functional groups have often been treated with alkyl chloroformates to decrease their polarity and increase their volatility prior to gas chromatography-mass spectrometry analysis. This derivatization reaction has two distinct advantages. It proceeds smoothly in aqueous media, and the desired reaction products are efficiently separated from interfering ionic components by their extraction into a water-immiscible organic phase.

Study of disulfide reduction and alkyl chloroformate derivatization of plasma sulfur amino acids using gas chromatography-mass spectrometry.

Four disulfide-reducing agents, dithiothreitol (DTT), 2,3-dimercaptopropanesulfonate (DMPS), and the newly tested 2-mercaptoethanesulfonate (MESNA) and Tris(hydroxypropyl)phosphine (THP), were investigated in detail for release of sulfur amino acids in human plasma. After protein precipitation with trichloroacetic acid (TCA), the plasma supernatant was treated with methyl, ethyl, or propyl chloroformate via the well-proven derivatization-extraction technique and the products were subjected to gas chromatographic-mass spectrometric (GC-MS) analysis. All the tested agents proved to be rapid and effective reducing agents for the assay of plasma thiols.

[Biochemic evidence of the presence of urine in a drain following surgery].

Objective: Evaluation of the laboratory investigations of the postoperative wound drains liquids containing urine and establishing the borderline levels for confirmation of the urine presence. PATIENTS GROUP AND THE METHODS: Biochemical analysis of the drain liquids, urine and blood serum from the 34 patients with confirmed urine leak out of the urinary tract. The urea, creatinine, natrium, potassium and chloride levels were measured in all samples.

Heptafluorobutyl chloroformate-based sample preparation protocol for chiral and nonchiral amino acid analysis by gas chromatography.

Gas chromatography (GC) is a commonly used technique in amino acid analysis (AAA). However, one of the requirements of the application of GC for AAA is a need for the polar analytes to be converted into their volatile, thermally stable derivatives. In the last two decades, alkyl chloroformates have become attractive derivatization reagents.

[Five-year follow up in patients after surgery for clear cell renal carcinoma].

Objective: Evaluation of the five-year follow-up of patients treated for clear-cell renal carcinoma in dependency on its characteristic and extension. PATIENTS' COHORT AND METHODS: Retrospective analysis of five-year follow-up of 269 patients treated for clear-cell renal carcinoma in dependency on T, N, M and clinical tumor stage; presence of lymphatic and distant metastases, cellular grade and tumor necrosis. Tumor-specific surviving is presented on Kaplan-Meier curves.

Stability margin of linear systems with parameters described by fuzzy numbers.

This paper deals with the linear systems with uncertain parameters described by fuzzy numbers. The problem of determining the stability margin of those systems with linear affine dependence of the coefficients of a characteristic polynomial on system parameters is studied. Fuzzy numbers describing the system parameters are allowed to be characterized by arbitrary nonsymmetric membership functions.

GC separation of amino acid enantiomers via derivatization with heptafluorobutyl chloroformate and Chirasil-L-Val column.

Heptafluorobutyl chloroformate (HFBCF), a recently introduced derivatization reagent, was examined in enantioseparation of amino acids (AAs) by GC. Twenty proteinogenic AAs, plus ornithine, cystine and 4-fluorophenylalanine (internal standard) were treated with the reagent and separation properties of the derivatives were assessed on a Chirasil-Val capillary column. Nineteen AA enantiomers were efficiently separated in 43 min except proline, arginine and cystine.

Prolyl-hydroxyproline dipeptide in non-hydrolyzed morning urine and its value in postmenopausal osteoporosis.

Background: Owing to the high correlation between the level of prolyl-4-hydroxyproline dipeptide in non-hydrolyzed urine and that of 4-hydroxyproline in hydrolyzed urine, we examined whether the dipeptide might function as a valuable marker of bone turnover.

Methods: Based on densitometric measurements, 68 postmenopausal women were divided into groups of non-osteopathic, osteopenic and osteoporotic subjects. The dipeptide and current urinary resorption markers were assayed in morning urine, the former using liquid chromatography, the others plus serum formation markers by means of immunoassay procedures.

Gas chromatographic-mass spectrometric analysis of biomarkers related to folate and cobalamin status in human serum after dimercaptopropanesulfonate reduction and heptafluorobutyl chloroformate derivatization.

Methylmalonic acid and total homocysteine belong to useful clinical indicators of cobalamin and folate status and are commonly measured separately. A sensitive and rapid method has been developed for simultaneous determination of both biomarkers and related metabolites in serum or plasma by isotope dilution gas chromatography-mass spectrometry (GC/MS). Thiols bound in disulfide bonds were released with 2,3-dimercapto-1-propanesulfonic acid (DMPS), and after deproteinization, they were phase-transfer derivatized with heptafluorobutyl chloroformate (HFBCF) in a single step.

Fluoroalkyl chloroformates in treating amino acids for gas chromatographic analysis.

Novel fluoroalkyl chloroformates with three and four carbon atoms were investigated for the immediate conversion of amino acids into hydrophobic derivatives in water-containing media. Derivatization conditions were extensively studied and optimized sample preparation protocols elaborated. More than 30 amino acids were treated with the particular reagent in isooctane by simply vortexing the reactive organic phase with a slightly basified aqueous medium containing pyridine or 3-picoline as a catalyst.

Gas chromatographic analysis of amino acid enantiomers in Carbetocin peptide hydrolysates after fast derivatization with pentafluoropropyl chloroformate.

A novel sample preparation protocol for gas chromatographic (GC) analysis of amino acid enantiomers in peptides was developed. It comprises traditional acid hydrolysis, a novel treatment of the analytes with a fluoroalkyl chloroformate and GC/FID separation of enantiomers on a chiral capillary column. The major improvements consist in that the derivatization step proceeds in organic-aqueous media within seconds and the amino acid derivatives are volatile enough to suit the temperature range of the chiral Chirasil-Val capillary column.