Sándor Kemény

Long-term psychological and sexual outcomes of severe penile hypospadias repair

INTRODUCTION Hypospadias is the most common penis malformation, and there exist a variety of surgical approaches used to correct the abnormal position of the meatus. Although the long-term outcomes of surgery are considered important for psychosexual development, only a few attempts have been made to evaluate patient satisfaction. AIM The aim of our study was to evaluate surgical results and psychosocial adaptations in a homogeneous group of subjects with severe penile hypospadias who underwent the same types of surgical repairs during childhood and compare the results to data obtained from age-matched healthy controls. METHODS In this cross-sectional study, 104 men (between 24 and 42 years old) who underwent an uncomplicated two-stage hypospadias repair in their childhood and 63 age-matched healthy men without genital malformations completed the questionnaire. MAIN OUTCOME MEASURES   Difference in self-perception assessed by a 15-item questionnaire regarding psychosexual well-being and penile appearance between subjects with corrected hypospadias and healthy participants. RESULTS On average, subjects with a hypospadias repair were less satisfied with their genital appearance; however, they were more satisfied with their sex lives compared to healthy controls. The meatus distance was approximately 1.5 cm from the tip of the penis after surgical correction. None of the postoperative surgical results correlated with patient satisfaction. Furthermore, the small percentage of patients (11%) who were very unsatisfied with their surgical outcomes had no significant differences in surgical outcomes compared to satisfied patients. However, there was a significant difference between the two groups in almost all psychological outcome measures. CONCLUSIONS In adults who underwent an uncomplicated ventral repair of a severe penile hypospadias 20-30 years earlier, healthy psychosexual development was achieved despite the lack of a glanular meatus. Early identification of unsatisfied patients is important for appropriate long-term follow-up and counseling.

Supercritical fluid extraction: A novel method for the resolution of tetramisole

Abstract A new resolution method, based on the selective distribution of enantiomers between a chiral solid and an achiral supercritical fluid phase, is reported. The chiral solid phase is formed from the optically active dicarboxylic acid derivative, (2 R ,3 R )- O , O ′-dibenzoyltartaric acid, and the racemic base (tetramisole). A new method is also described for the enrichment of enantiomeric mixtures which have an enantiomeric ratio other than 1:1. This is based on the partial salt formation of the enantiomeric mixture with an achiral substance, which is then followed by supercritical fluid extraction of the free enantiomer. The extract has an enantiomeric composition which is different from the starting mixture. The method is applied to an enantiomeric mixture of tetramisole with hydrochloric acid.

Performance of the ridge regression method as applied to complex linear and nonlinear models

Three practical cases for application of ridge regression are studied and illustrated through mathematical derivation and computer simulation. The first case is the multiple linear model with parameters of similar magnitude, where the choice between the correlation form and original form arose. It is shown that the use of correlation form (centering and scaling the variables) gives worse parameter estimates than the use of the original form, thus keeping the original variables is advisable. The second case is the linear model with parameters of different order of magnitude. The conclusion is that this difference should be considered as far as possible by appropriate scaling during parameter estimation. The third case is a nonlinear model, where the method is also applicable. In all three cases, the improvement to the ordinary least squares (OLS) method is tremendous, in both the relevant mean square error function and the ridge trace.

Treatment of binary Vapour-Liquid equilibrium data

Abstract The results obtained by minimizing the sum of squares of different functions of measured variables x , t , y , P ; with and without weighting are compared. The unweighted regression leads to different values of estimated parameters according to the type of minimization criterion. It is shown that the weighted regression of x , t , y data gives rise to the same values of estimated parameters not depending on the type of minimization criterion. This is also true for x , t , P data. It is shown that the simultaneous correlation of x , t , y , P data is erroneous but this statement is valid only for “classical” treatment. A very simple method is proposed based on the concept of “multiresponse model” for treatment of all ( x , t , y , P ) data together.

Recovery of a bioactive sesquiterpene lactone fromTanacetum parthenium by extraction with supercritical carbon dioxide

SummaryThe isolation of parthenolide-rich products from feverfew (Tanacetum parthenium (L.) Sch.) with supercritical carbon dioxide extraction has been investigated. A 32 full-factorial design was used to map the effects of pressure and temperature on the extraction yields and on the yield of parthenolide. The composition of the essential oil of feverfew obtained by hydrodistillation was compared with that of the SFE extract containing the volatile compounds.

Mg-Al 3:1 hydrotalcite catalyst in the synthesis of cyclopropane carboxylic acid derivatives

Abstract The non-activated Mg-Al 3:1 hydrotalcite is a suitable basic catalyst both in the intramolecular cyclization reaction of malonic acid allylic esters into bicyclic cyclopropane carboxylic acid lactones and the intermolecular cyclization reaction of dibromoethane and diethyl malonate into cyclopropane dicarboxylic acid diester. The optimal reaction conditions of the intramolecular cyclization were determined using a 2 4 factorial design. An interesting effect on the diastereoselectivity of the intramolecular cyclization was observed compared with the diastereoselectivity of this cyclization using solid potassium carbonate as base.

Identification of the factors affecting the analytical results of food allergen ELISA methods

In order to support patients’ safety, the analytical methods should be able to quantify the allergenic proteins in food products. Analytical performance of the currently used ELISA methods is not always appropriate, particularly in case of processed foods. A possible way to investigate the sources of analytical errors is the utilisation of model food matrices that mimic the technology and behaviour of real food products. Consequently, factors affecting the analytical results were identified, their contribution to the whole analytical error was determined, and the underlying phenomena were interpreted in this study. Heat-treated model matrices incurred with gliadin, milk, egg, or soy proteins were produced and analysed with commercially available ELISA test kits. The data were evaluated with statistical tools. Results clearly show that the type of the food matrix, the level of processing, and the analytical methods (i.e. the type of the ELISA kit) are the three main factors that play a significant role in the uncertainty. The developed laboratory methodology seems to be suitable for generalising the investigation of other allergens, methods, matrices, and the scientific background of the phenomena.

Thermodynamic consistency of data banks

Abstract Data sets originated from different sources are typically used simultaneously either in data banks or in data bases of flowsheeting programs. If these data sets concern different kinds of data, they ought to be in accordance with the laws of thermodynamics. This is not assured, however, and in many cases it is not even checked. Methods used for data compilation rely on approximate models, which may bias the residuals. Two model-free methods are proposed, where the residuals of the thermodynamic differential equations are investigated. The first method is a χ2 test based on a quadratic form of the f residuals, involving variances of the elementary measurements, if they are available. The second method is a rather sensitive trend/shift analysis of residuals, which does not require the knowledge of error variances. The examples are the Clausius-Clapeyron equation, a binary vapor-liquid equilibrium data set and a simultaneous treatment of PVT and caloric data.

On the computation of the noncentral F and noncentral beta distribution

Unfortunately many of the numerous algorithms for computing the comulative distribution function (cdf) and noncentrality parameter of the noncentral F and beta distributions can produce completely incorrect results as demonstrated in the paper by examples. Existing algorithms are scrutinized and those parts that involve numerical difficulties are identified. As a result, a pseudo code is presented in which all the known numerical problems are resolved. This pseudo code can be easily implemented in programming language C or FORTRAN without understanding the complicated mathematical background.Symbolic evaluation of a finite and closed formula is proposed to compute exact cdf values. This approach makes it possible to check quickly and reliably the values returned by professional statistical packages over an extraordinarily wide parameter range without any programming knowledge.This research was motivated by the fact that a very useful table for calculating the size of detectable effects for ANOVA tables contains suspect values in the region of large noncentrality parameter values compared to the values obtained by Patnaik’s 2-moment central-F approximation. The cause is identified and the corrected form of the table for ANOVA purposes is given. The accuracy of the approximations to the noncentral-F distribution is also discussed.

Kinetic comparison of enantioselective hydrogenations

Abstract Kinetic investigation of the Pd/carbon-(S)-proline system in reduction of isophorone and acetophenone and comparison with known enantioselective hydrogenations were camed out. An addition reaction of (S)-proline with the substrates, and the selective hydrogenation of this adduct results in the optically active products, the kinetic analysis verified this mode of action: these are rather diastereoselective reactions.