bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher Powers of Quantum White Noises in Terms of Integral Kernel Operators
Authors: Chung Dong Myung , Ji Un Cig , Obata Nobuaki
Published: October 2003

A rigorous mathematical formulation of higher powers of quantum white noises is given on the basis of the most recent theory of white noise distributions due to Cochran, Kuo and Sengupta. The renormalized quantum Itô formula due to Accardi, Lu and Volovich is derived from the renormalized product formula based on integral kernel operators on white noise functions. During the discussion, the analytic characterization of operator symbols and the expansion theorem for a white noise operator in terms of integral kernel operators are established.
The Approach to Equilibrium of a Class of Quantum Dynamical Semigroups
Authors: Fagnola Franco , Rebolledo Rolando
Published: October 2003

This paper deals with the asymptotic behavior of a quantum dynamical semigroup [Formula: see text] acting on the algebra of all linear bounded operators on a given Hilbert space. In practice, all these semigroups have a generator which can be written in a well-known form named after Lindblad and Davies. If the semigroup has a faithful normal stationary state ρ, necessary and sufficient conditions are derived for the w*-convergence of [Formula: see text] to [Formula: see text], where [Formula: see text] is the conditional expectation of an element X onto the subalgebra of fixed points. Our main results are expressed in terms of the Lindblad–Davies generator .
Infinitesimal Generators on the Quantum Group SUq(2)
Authors: Schürmann Michael , Skeide Michael
Published: October 2003

Quantum Lévy processes on a quantum group are, like classical Lévy processes with values in a Lie group, classified by their infinitesimal generators. We derive a formula for the infinitesimal generators on the quantum group SU q(2) and decompose them in terms of an infinite-dimensional irreducible representation and of characters. Thus we obtain a quantum Lévy–Khintchine formula.
Extreme Points of the Convex set of Stochastic Maps on A C*-Algebra
Authors: Parthasarathy K. R.
Published: October 2003

Let [Formula: see text] be a unital C*-subalgebra of the C*-algebra ℬ(ℋ) of all bounded operators on a complex separable Hilbert space ℋ. Let [Formula: see text] denote the convex set of all unital, linear, completely positive and normal maps of [Formula: see text] into itself. Using Stinespring's theorem, we present a criterion for an element [Formula: see text] to be extremal. When [Formula: see text], this criterion leads to an explicit description of the set of all extreme points of [Formula: see text]. We also obtain a quantum probabilistic analogue of the classical Birkhoff's theorem2 that every bistochastic matrix can be expressed as a convex combination of permutation matrices.
Stochastic Differential Equations in White Noise Space
Authors: Kuo H.-H. , Xiong J.
Published: October 2003

We study infinite dimensional stochastic differential equations taking values in a white noise space. We show that under certain assumptions the distribution laws of the solution of such an equation induce generalized functions. The white noise integral equation satisfied by these generalized functions is derived. We apply the results to study the stochastic fluctuation of a two-dimensional neuron.
Eigenvalue Density of the Wishart Matrix and Large Deviations
Authors: Hiai Fumio , Petz Dénes
Published: October 2003

A large deviation theorem is obtained for a certain sequence of random measures which includes the empirical eigenvalue distribution of Wishart matrices, as the matrix size tends to infinity. The rate function is convex and one of its ingredients is the logarithmic energy. In the case of the singular Wishart matrix, the limit distribution has an atom.
A Characterization of Pure Finitely Correlated States
Authors: Matsui Taku
Published: October 2003

We give a characterization of pure finitely correlated states (quantum Markov states) as zero energy states of UHF algebras.
Interacting Fock Spaces and Gaussianization of Probability Measures
Authors: Accardi Luigi , Bożejko Marek
Published: October 2003

We prove that any probability measure on ℝ, with moments of all orders, is the vacuum distribution, in an appropriate interacting Fock space, of the field operator plus (in the nonsymmetric case) a function of the number operator. This follows from a canonical isomorphism between the L2-space of the measure and the interacting Fock space in which the number vectors go into the orthogonal polynomials of the measure and the modified field operator into the multiplication operator by the x-coordinate. A corollary of this is that all the momenta of such a measure are expressible in terms of the Szëgo–Jacobi parameters, associated to its orthogonal polynomials, by means of diagrams involving only noncrossing pair partitions (and singletons, in the nonsymmetric case). This means that, with our construction, the combinatorics of the momenta of any probability measure (with all moments) is reduced to that of a generalized Gaussian. This phenomenon we call Gaussianization. Finally we define, in terms of the Szëgo–Jacobi parameters, a new convolution among probability measures which we call universal because any probability measure (with all moments) is infinitely divisible with respect to this convolution. All these results will be extended to the case of many (in fact infinitely many) variables in a future paper.
Conservation of Amino Acids into Multiple Alignments Involved in Pairwise Interactions in Three-Dimensional Protein Structures
Authors: Errami Mounir , Geourjon Christophe , Deléage Gilbert
Published: October 2003

We present an original strategy, that involves a bioinformatic software structure, in order to perform an exhaustive and objective statistical analysis of three-dimensional structures of proteins. We establish the relationship between multiple sequences alignments and various structural features of proteins. We show that amino acids implied in disulfide bonds, salt bridges and hydrophobic interactions are particularly conserved. Effects of identity, global similarity within alignments, and accessibility of interactions have been studied. Furthermore, we point out that the more variable the sequences within a multiple alignment, the more informative the multiple alignment. The results support multiple alignments usefulness for predictions of structural features.
BTEVAL: A Server for Evaluation of β-Turn Prediction Methods
Authors: Kaur Harpreet , Raghava G. P. S.
Published: October 2003

This paper describes a web server BTEVAL, developed for assessing the performance of newly developed β-turn prediction method and it's ranking with respect to other existing β-turn prediction methods. Evaluation of a method can be carried out on a single protein or a number of proteins. It consists of clean data set of 426 non-homologous proteins with seven subsets of these proteins. Users can evaluate their method on any subset or a complete set of data. The method is assessed at amino acid level and performance is evaluated in terms of Qtotal, Qpredicted, Qobserved and MCC measures. The server also compares the performance of the method with other existing β-turn prediction methods such as Chou-Fasman algorithm, Thornton's algorithm, GORBTURN, 1-4 and 2-3 Correlation model, Sequence coupled model and BTPRED. The server is accessible from
A Comprehensive Whole Genome Bacterial Phylogeny Using Correlated Peptide Motifs Defined in a High Dimensional Vector Space
Authors: Stuart Gary W. , Berry Michael W.
Published: October 2003

As whole genome sequences continue to expand in number and complexity, effective methods for comparing and categorizing both genes and species represented within extremely large datasets are required. Methods introduced to date have generally utilized incomplete and likely insufficient subsets of the available data. We have developed an accurate and efficient method for producing robust gene and species phylogenies using very large whole genome protein datasets. This method relies on multidimensional protein vector definitions supplied by the singular value decomposition (SVD) of a large sparse data matrix in which each protein is uniquely represented as a vector of overlapping tetrapeptide frequencies. Quantitative pairwise estimates of species similarity were obtained by summing the protein vectors to form species vectors, then determining the cosines of the angles between species vectors. Evolutionary trees produced using this method confirmed many accepted prokaryotic relationships. However, several unconventional relationships were also noted. In addition, we demonstrate that many of the SVD-derived right basis vectors represent particular conserved protein families, while many of the corresponding left basis vectors describe conserved motifs within these families as sets of correlated peptides (copeps). This analysis represents the most detailed simultaneous comparison of prokaryotic genes and species available to date.
An Interactive Tool for Extracting Exons and SNP from Genomic Sequence: Isolation of HCN1 and HCN3 Ion Channel Genes
Authors: Liu Yuan , Wang Yuhong , Folander Kimberly , Xie Guochun , Blevins Richard
Published: October 2003

Genome Analyzer (GenoA) with a relational database back-end, was developed to extract information from mammalian genomic sequences. This data mining and visualization tool-set enables laboratory bench scientists to identify and assemble virtual cDNA from genomic exon sequences, and provides a starting point to identify potential alternative splice variants and polymorphisms in silico. The study described in this paper demonstrates the use of GenoA to study human brain hyperpolarization-activated cation channel genes HCN1 and HCN3.
Predicting Risk of Coronary Artery Disease from DNA Microarray-Based Genotyping Using Neural Networks and Other Statistical Analysis Tool
Authors: Tham C. K. , Heng C. K. , Chin W. C.
Published: October 2003

This paper presents a novel approach for complex disease prediction that we have developed, exemplified by a study on risk of coronary artery disease (CAD). This multi-disciplinary approach straddles fields of microarray technology and genetics, neural networks (NN), data mining and machine learning, as well as traditional statistical analysis techniques, namely principal components analysis (PCA) and factor analysis (FA). A description of the biological background of the study is given, followed by a detailed description of how the problem has been modeled for analyses by neural networks and FA. A committee learning approach for NN has been used to improve generalization rates. We show that our NN approach is able to yield promising prediction results despite using only the most fundamental network structures. More interestingly, through the statistical analysis process, genes of similar biological functions have been clustered. In addition, a gene marker involved in breaking down lipids has been found to be the most correlated to CAD.
Use of Gene Networks for Identifying and Validating Drug Targets
Authors: Imoto Seiya , Savoie Christopher J. , Aburatani Sachiyo , Kim Sunyong , Tashiro Kousuke , Kuhara Satoru , Miyano Satoru
Published: October 2003

We propose a new method for identifying and validating drug targets by using gene networks, which are estimated from cDNA microarray gene expression profile data. We created novel gene disruption and drug response microarray gene expression profile data libraries for the purpose of drug target elucidation. We use two types of microarray gene expression profile data for estimating gene networks and then identifying drug targets. The estimated gene networks play an essential role in understanding drug response data and this information is unattainable from clustering methods, which are the standard for gene expression analysis. In the construction of gene networks, we use the Bayesian network model. We use an actual example from analysis of the Saccharomyces cerevisiae gene expression profile data to express a concrete strategy for the application of gene network information to drug discovery.
Cluster Analysis of Dynamic Parameters of Gene Expression
Authors: Wu Xiwei , Dewey T. Gregory
Published: October 2003

Cluster analysis has proven to be a valuable statistical method for analyzing whole genome expression data. Although clustering methods have great utility, they do represent a lower level statistical analysis that is not directly tied to a specific model. To extend such methods and to allow for more sophisticated lines of inference, we use cluster analysis in conjunction with a specific model of gene expression dynamics. This model provides phenomenological dynamic parameters on both linear and non-linear responses of the system. This analysis determines the parameters of two different transition matrices (linear and nonlinear) that describe the influence of one gene expression level on another. Using yeast cell cycle microarray data as test set, we calculated the transition matrices and used these dynamic parameters as a metric for cluster analysis. Hierarchical cluster analysis of this transition matrix reveals how a set of genes influence the expression of other genes activated during different cell cycle phases. Most strikingly, genes in different stages of cell cycle preferentially activate or inactivate genes in other stages of cell cycle, and this relationship can be readily visualized in a two-way clustering image. The observation is prior to any knowledge of the chronological characteristics of the cell cycle process. This method shows the utility of using model parameters as a metric in cluster analysis.
Computational Strategies for Analyzing Data in Gene Expression Microarray Experiments
Authors: Aittokallio Tero , Kurki Markus , Nevalainen Olli , Nikula Tuomas , West Anne , Lahesmaa Riitta
Published: October 2003

Microarray analysis has become a widely used method for generating gene expression data on a genomic scale. Microarrays have been enthusiastically applied in many fields of biological research, even though several open questions remain about the analysis of such data. A wide range of approaches are available for computational analysis, but no general consensus exists as to standard for microarray data analysis protocol. Consequently, the choice of data analysis technique is a crucial element depending both on the data and on the goals of the experiment. Therefore, basic understanding of bioinformatics is required for optimal experimental design and meaningful interpretation of the results. This review summarizes some of the common themes in DNA microarray data analysis, including data normalization and detection of differential expression. Algorithms are demonstrated by analyzing cDNA microarray data from an experiment monitoring gene expression in T helper cells. Several computational biology strategies, along with their relative merits, are overviewed and potential areas for additional research discussed. The goal of the review is to provide a computational framework for applying and evaluating such bioinformatics strategies. Solid knowledge of microarray informatics contributes to the implementation of more efficient computational protocols for the given data obtained through microarray experiments.
Integral observability operators of nonlinear dynamical systems
Authors: Zaika Yury V.
Published: October 2003

In terms of functional dependence, the description of
observable functions in nonlinear dynamical systems, which are
analytic with respect to phase variables, is obtained. For
processing of measurements, integral operators are used, which
provide certain noise stability of operation of phase state
reconstruction. The analogue of the duality theory known for
linear problems of observation and control is developed.
Computing schemes for nonlinear observability problem are
proposed.
Compactness in Wiener amalgams on locally compact groups
Authors: Pandey S. S.
Published: October 2003

We study the compactness of bounded subsets in a Wiener amalgam
whose local and global components are solid Banach function (BF)
spaces on a locally compact group. Our main theorem
provides a generalization of the corresponding results of Feichtinger. This paper paves the way for the study
of compact multiplier operators on general Wiener amalgams on the
lines of Feichtinger.
Supplementation of a Low-Carotenoid Diet with Tomato or Carrot Juice Modulates Immune Functions in Healthy Men
Authors: Watzl Bernhard , Bub Achim , Briviba Karlis , Rechkemmer Gerhard
Published: October 2003

Background: β-Carotene has been shown to enhance immune functions in humans. Whether vegetables rich in carotenoids, such as β-carotene or lycopene, modulate immune functions in healthy humans is presently not known. The objective of this study was to investigate the effects of a low-carotenoid diet supplemented with either tomato (providing high amounts of lycopene) or carrot juice (providing high amounts of α- and β-carotene) on immune functions in healthy men. Method: In a blinded, randomized, cross-over study, male subjects on a low-carotenoid diet consumed 330 ml/day of either tomato juice (37.0 mg/day lycopene) or carrot juice (27.1 mg/day β-carotene and 13.1 mg/day α-carotene) for 2 weeks with a 2-week depletion period after juice intervention. Immune status was assessed by measuring lytic activity of natural killer (NK) cells, secretion of cytokines (IL-2, IL-4, TNFα), and proliferation by activated peripheral blood mononuclear cells. Results: Juice consumption resulted in relatively fast responses in plasma carotenoid concentrations (p < 0.0002) which were not accompanied by concomitant changes in immune functions. For IL-2, NK cell cytotoxicity, and lymphocyte proliferation, maximum responses were observed during depletion periods. The highest production rate was measured only for TNFα at the end of the first intervention period. Juice intervention did not modulate the secretion of IL-4. Conclusions: Increased plasma carotenoid concentrations after vegetable juice consumption are accompanied by a time-delayed modulation of immune functions in healthy men consuming a low-carotenoid diet.
The Role of Dietary Supplementation with L-Glutamine in Inflammatory Mediator Release and Intestinal Injury in Hypoxia/Reoxygenation-Induced Experimental Necrotizing Enterocolitis
Authors: Akisu Mete , Baka Meral , Huseyinov Afig , Kultursay Nilgun
Published: October 2003

Background/Aims: Necrotizing enterocolitis (NEC) is a multifactorial syndrome in the neonate. Enteral feeding practices are an important component of gastrointestinal injury in neonatal NEC. In the present study, we examined the protective effect of oral supplementation with L-glutamine, an important specific fuel for the enterocytes, against hypoxia-reoxygenation (H/R)-induced NEC in young mice. Methods: Young mice were divided into four groups: group 1 mice (untreated) underwent H/R; group 2 mice were supplemented with L-glutamine in drinking water (0.5 g/dl) for 3 days, and group 3 mice were supplemented with L-glutamine (3 g/dl) for 10 days. Group 4 mice served as control. Hypoxia was induced by placing the young mice in a 100% CO2 chamber for 5 min. After hypoxia, they were reoxygenated for 10 min with 100% oxygen. We examined the intestinal lesions with light microscopy and measured intestinal generation of PAF and TNF-α in the H/R-induced model of NEC. Results: In group 3 mice, NEC-induced intestinal tissue damage was greatly attenuated with necrosis limited partially to the mucosa. Both intestinal tissue PAF and TNF-α concentrations were significantly higher in the untreated group than in controls (p < 0.001). Group 3 mice (3 g/dl supplemented) showed a significant decrease in intestinal TNF-α concentration compared with young group 1 and group 2 mice (p < 0.05 and p < 0.05, respectively). On the other hand, no significant difference was observed in the intestinal generation of PAF between H/R groups (p > 0.05). Conclusion: The present study suggests that H/R plays an important role in the pathogenesis of NEC and supports the hypothesis that especially PAF and TNF-α are involved in the pathophysiological mechanism of H/R-induced NEC. This study also demonstrates that dietary supplementation with L-glutamine reduces the histologic evidence of H/R-induced intestinal injury. Based on these findings, beneficial effects of L-glutamine in this model of NEC are mediated via mechanisms inhibiting intestinal cytokine release.
Dietary Intake of 10- to 16-Year-Old Children and Adolescents in Central and Northern Europe and Association with the Incidence of Type 1 Diabetes
Authors: Thorsdottir I. , Ramel A.
Published: October 2003

Background/Aims: The highest incidence of type 1 diabetes is among 10- to 15-year-old adolescents. The aim of this study was to investigate a possible relationship between the dietary intake of this group and the incidence of type 1 diabetes. Methods: Dietary intake data of 10- to 16-year-old adolescents (n = 4,701) from 11 European countries and the incidence rates of type 1 diabetes were used to examine the relation between food and the disease. Results: The incidence of type 1 diabetes correlated with the consumption of total fat (r = 0.674; p = 0.023), saturated fatty acids (r = 0.714; p = 0.047) and the intake of fruits and vegetables (r = 0.786; p = 0.036). Fruit intake or vegetable intake alone did not correlate with the incidence. Cow’s milk and animal product consumption correlated with the incidence when Icelandic data were excluded (r = 0.829; p = 0.042 and r = 0.999; p = 0.001). A negative correlation of borderline significance was found between sugar intake and the incidence of type 1 diabetes (r = –0.721; p = 0.068). Conclusion: The results indicate for the first time that an adolescent’s diet high in fat and fruits and vegetables is associated with an increased risk of type 1 diabetes. Fruit or vegetable intake separately was not associated with type 1 diabetes. It is important to characterize and minimize diabetogenic factors in fruits and vegetables as the general health benefits of a diet rich in fruits and vegetables are well known and such a diet is therefore recommended. This study supports previous research about the importance of cow’s milk and animal products in the aetiology of type 1 diabetes.
Serum Retinol, Iron Status and Body Composition of Lactating Women in Nandi, Kenya
Authors: Ettyang G.A. , van Marken Lichtenbelt W.D. , Oloo A. , Saris W.H.M.
Published: October 2003

Background: Maternal vitamin A and iron status was investigated among lactating mothers in a rural community in Kenya. The aim of the study was to establish the prevalence and the relationship of these key nutrients to maternal body composition. Methods: Eighty-eight mothers provided samples of breast milk and blood for determination of breast milk vitamin A, serum retinol and ferritin. Estimators of body composition were based on the mother’s weight, height and skinfold measurements. Results: A total of 78.1% women had breast milk retinol <1.05 µmol/l with 38 and 62% having lactated for a period of <4 and >4 months, respectively. Prevalence of severely deficient serum retinol <0.35 µmol/l and ferritin <12 µg/l was 10 and 37%, respectively. Women with serum ferritin <12 µg/l had significantly lower average hemoglobin (p < 0.01), hematocrit (p < 0.01) and serum retinol (p < 0.05). Serum retinol of mothers who had lactated for <4 months was significantly but negatively correlated with total body fat (r = –0.40; p < 0.05). With a lactation period of >4 months a close relationship was found between serum retinol and hemoglobin (r = 0.26; p <0.01), serum retinol and serum ferritin (r = 0.20; p < 0.05), and fat free mass significantly but negatively correlated with breast milk fat (r = –0.27; p < 0.05). Serum retinol in combination with hematocrit significantly affected both maternal hemoglobin (p < 0.01) and serum ferritin (p < 0.01). Conclusion: A high prevalence of vitamin A and iron deficiency was observed in this group of lactating women. Low levels of fat mass were directly related to these indicators of malnutrition.
Body Composition, Eating Behavior, Food-Body Concerns and Eating Disorders in Adolescent Girls
Authors: Boschi V. , Siervo M. , D’Orsi P. , Margiotta N. , Trapanese E. , Basile F. , Nasti G. , Papa A. , Bellini O. , Falconi C.
Published: October 2003

Aims: Dieting is a behavioral phenomenon which is becoming more frequent among adolescents and the search for weight loss, through dieting, may result in an unbalanced nutrition both quantitatively and qualitatively. Our study intended to look at the eating habits and behavior on a cohort of adolescent girls to verify the presence of unbalanced diets and the prevalence of eating disorders with particular attention to the partial syndromes (EDNOS). Methods: A cross-sectional double-stage study was carried out on a group of schoolgirls in the suburbs of Naples. We assessed anthropometrical measures, body composition (skinfolds and bioimpedance analysis), dietary intake by means of 3-day food records and we administered the Eating Disorder Inventory 2 and Psychosocial Factor Risk Questionnaire. A multidisciplinary and double-stage approach had been used to get a better diagnosis of eating disorders in our sample. Results: 156 adolescent girls, 14–18 years old, took part in our study. Height, weight, and BMI were 160.38 cm, 58 kg and 22.6, respectively. Analysis of food intake showed that all the values reported, with the exception of lipids and sodium, were below the recommendations by LARN. We observed a prevalence of 1.28% of bulimia nervosa, 1.28% of binge eating, and 10.25% of eating disorders not otherwise specified. EDI 2 and PRFQ confirmed how important drive for thinness and body dissatisfaction dimensions are when we deal with adolescent girls and with the phenomenon of dieting. The study confirmed the validity of the PRFQ questionnaire to evaluate mass media influence on body perception and eating behavior of adolescents. Conclusion: Multidisciplinary and well-designed studies are needed to systematically and accurately study eating habits and behavior of adolescents to tackle more efficiently the increasing spread of eating disorders and obesity.
Effect of Vitamin C Supplementation on Oxidative DNA Damage in an Experimental Model of Lead-Induced Hypertension
Authors: Attri Jyotika , Dhawan Veena , Mahmood Safrun , Pandhi Promila , Parwana H.K. , Nath Ravinder
Published: October 2003

Aims: Chronic exposure to lead results in sustained hypertension in humans and experimental animals. We investigated the possible role of reactive oxygen species (ROS) and their impact on DNA damage in lead-induced hypertension. Further the effect of short-term supplementation of vitamin C is also demonstrated. Methods: Male Wistar rats were treated with either lead acetate (100 ppm) alone or lead acetate plus vitamin C (20 mg/rat/day). The control rats were fed regular rat chow. Blood pressure, antioxidants, total antioxidant status as measured by ferric-reducing antioxidant power, nitric oxide (NO) metabolites, malondialdehyde (MDA) and 8-hydroxy 2-deoxyguanosine were determined after 0, 1, 2 and 3 months. Results: The lead-exposed group showed a significant rise in blood pressure, lipid peroxidation (MDA) and a substantial oxidative damage to the DNA. A significant fall in NO metabolites, total antioxidant levels and ferric-reducing antioxidant power was also observed in this group. Concomitant administration of vitamin C ameliorated hypertension, normalized NO levels and abrogated lipid peroxidation. Also, it completely prevented oxidative damage to the DNA. Conclusions: These findings point to enhanced ROS-mediated inactivation and sequestration of NO which can potentially contribute to hypertension, lipid peroxidation, reduced antioxidant status and oxidative DNA damage. The beneficial effects of vitamin C on these parameters support the role of increased ROS activity in the pathogenesis of these abnormalities in this model.
Higher Content of 18:1 Trans Fatty Acids in Subcutaneous Fat of Persons with Coronarographically Documented Atherosclerosis of the Coronary Arteries
Authors: Dlouhý P. , Tvrzická E. , Staňková B. , Vecka M. , Žák A. , Straka Z. , Fanta J. , Pachl J. , Kubisová D. , Rambousková J. , Bílková D. , Anděl M.
Published: October 2003

Aim: To identify the total content of trans fatty acid (TFA) isomers and C18:1 trans isomers in subcutaneous fat samples from persons with atherosclerosis of the coronary arteries, as an indicator of dietary exposure. Methods: Using capillary gas chromatography, the authors determined total content of TFA isomers and C18:1 trans isomers in the subcutaneous fat of 34 patients with ischemic heart disease who had undergone aortocoronary bypass surgery and in 46 patients with no sign of coronary disease. Results: On average, the total TFAs in cardiac patients were 2.88 ± 1.19% of all fatty acids, in noncardiac patients 2.56 ± 0.89%. However, the difference is not statistically significant. The average concentration of C18:1 trans in cardiac patients (2.31 ± 1.09%) was statistically significantly higher (p = 0.05) than in the noncardiac group (1.95 ± 0.77%). Conclusions: The results obtained indicate a lower TFA load in comparison with previous studies in other countries. A higher concentration of 18:1 TFAs in the subcutaneous fat of patients with coronary disease might be an impulse to correct the dietary habits of this very high-risk population.
Effect of an Oat Bran Enriched Diet on the Atherogenic Lipid Profile in Patients with an Increased Coronary Heart Disease Risk
Authors: Berg Aloys , König Daniel , Deibert Peter , Grathwohl Dominik , Berg Andreas , Baumstark Manfred W. , Franz Ingomar-Werner
Published: October 2003

Aim: To study whether an oat bran enriched diet has a specific effect in lowering total and low-density lipoprotein cholesterols, in addition to caloric and fat restriction. Methods: We performed a randomized, controlled, parallel-group, single-centre study in which 1,994 patients from the Wehrawald Hospital (Todtmoos, Germany) were screened and 235 met the criteria male gender, hypercholesterolemia, and overweight. All patients in the Wehrawald Hospital took part in a 4-week standardized inpatient lifestyle health program consisting of dietary intervention, increased physical activity, and health education. Caloric restriction, fat modification, and oat bran supplementation were part of the nutritional regimen within the lifestyle health program. Ninety-nine patients were randomized to a fat-modified diet with caloric restriction and a daily intake of 35–50 g oat bran and 136 patients to a fat-modified, oat bran-free diet with caloric restriction. Fifty-three male overweight but normocholesterolemic subjects were selected as controls. Results: The most significant decreases in total cholesterol (–67.7 ± 37.2 mg/dl; p < 0.01), low-density lipoprotein cholesterol (–56.3 ± 35.1 mg/dl; p < 0.01), and apolipoprotein B (–42.4 ± 34.1 mg/dl; p < 0.01) were found with the combination of the fat-modified and oat bran enriched food. Conclusions: Added to a fat-modified diet, oat bran within a practical range of intake significantly reduces total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B. These beneficial effects occurred independent of covariables such as physical activity or caloric and fat restriction in the diet.
Endocrine Effects of Food Intake: Insulin, Ghrelin, and Leptin Responses to a Single Bolus of Essential Amino Acids in Humans
Authors: Knerr I. , Gröschl M. , Rascher W. , Rauh M.
Published: October 2003

Background: This study deals with the physiological effects of an oral bolus of essential amino acids (AA) on the secretion of insulin, ghrelin and leptin in fasting humans. Methods: 12 healthy adults (age 18–40 years, 10 males, 2 females, body mass index 18.0–23.5 kg/m2) were included in our study. Seven fasted volunteers consumed an AA mixture (0.35 g/kg BW), 5 served as controls. Serum AA, glucose, albumin, urea and hormones were measured at 0, 15, 30 min and thereafter at 30-min intervals up to 5 h. Results: Glucose, albumin and urea remained constant, peak AA concentrations were achieved at 30 min for methionine (Met), at 60 min for all other AA. The insulin peak (533% compared to basal level, p < 0.01) at 30 min was earlier than the peaks of all AA except for Met. Ghrelin showed a continuous rise towards the end of the experiment leading to a 3-fold increase in initial concentrations in the study group (p < 0.001), significantly higher than in the control group (p < 0.05). In contrast, both groups exhibited almost constant leptin concentrations. Conclusion: Our data indicate that an oral low-dose AA bolus not only causes considerable hyperaminoacidemia and hyperinsulinemia but is also accompanied by an increased ghrelin secretion in fasted humans. This may be a specific effect or may be due to the fact that a single bolus of AA is not a sufficient stimulus to induce satiety. Leptin, however, is not a key mediator in this setting.
Neue Erkenntnisse in der Hormonersatztherapie
Authors: Winter R. , Haller U. , Hepp H.
Published: October 2003

Die Verabreichung von Östrogenen und Gestagenen erhöht das Risiko an Morbus Alzheimer zu erkranken und verbessert die kognitive Funktion des Gehirns nicht. Die Langzeitverabreichung einer Östrogenmonotherapie ist mit einem erhöhten Risiko für das Auftreten eines Ovarialkarzinoms verbunden.
Geschlechterstereotype in der Frauenheilkunde – Barrieren für junge Ärzte?
Authors: Buddeberg-Fischer Barbara
Published: October 2003

In den letzten Jahren zeichnet sich eine «Feminisierung» der Medizin ab, die in einigen Fachgebieten wie der Frauenheilkunde besonders ausgeprägt ist. In der vorliegenden Arbeit wird den Gründen für diesen Wandel anhand der Literatur und auf der Basis eigener Forschungsergebnisse nachgegangen. Im Jahr 2001 gingen von den neu verliehenen Facharzttiteln in Gynäkologie/Geburtshilfe in der Schweiz mehr als zwei Drittel an Frauen. Im Zuge der feministischen Frauenbewegung kam es in den letzten 20 Jahren zu einer Emanzipation der Frauen und der Forderung, dass sich Frauen nur von Frauen behandeln lassen sollten. Parallel zu dieser Entwicklung wandelten sich auch die Geschlechtsrollen: der Idealtyp für Frauen und Männer ist heute «androgyn». Junge Ärzte und Ärztinnen sind sowohl handlungsorientiert als auch emotionsbezogen. Die Angleichung der Geschlechtsrollen wirkt sich auf Lebensstil und Lebensplanung aus. Für eine immer grössere Zahl junger Ärzte und Ärztinnen hat der Beruf nicht mehr oberste Priorität. Junge Ärzte mit hoher Expressivität sind meist auch familienorientiert und entscheiden sich gerade deshalb nicht für eine Spezialisierung in der Frauenheilkunde. Anderseits finden sich unter den jungen Ärztinnen viele, die stärker handlungsorientiert sind und dem Beruf erste Priorität einräumen. Sollte es in den nächsten Jahren nicht gelingen, das Fachgebiet auch wieder für mehr junge Ärzte attraktiv zu gestalten, könnte es innerhalb der Frauenheilkunde zu einer «horizontalen Segregation» kommen: Ärztinnen werden im nichtoperativen, patientenzentrierten Bereich, ihre männlichen Kollegen im operativen und wissenschaftlichen Bereich tätig sein. Ein Fachgebiet lebt jedoch durch die Verschiedenheit und den Austausch der Geschlechter.
Die Lernkurve im Zusammenhang mit der Sectio caesarea
Authors: Müller Isabelle , Zimmermann Roland
Published: October 2003

Fragestellung: Wieviele Eingriffe muss ein angehender Facharzt unter Supervision durchführen, um in der Lage zu sein, eine Sectio caesarea selbständig durchzuführen? Methode: Bei allen Facharztanwärtern für Frauenheilkunde einer 5-Jahres-Periode wurden Lernkurven für mehrere Parameter im Zusammenhang mit der Sectio caesarea erstellt und ausgewertet (Blutverlust, Hospitalisationsdauer, Apgar-Werte, pH der Nabelschnurarterie, Induktion-Entbindung-Zeit, Uterotomie-Entbindung-Zeit, totale Operationszeit). Der Übergang vom steilen zum flachen Teil der Kurve wurde visuell festgelegt und als Abschluss der initialen Lernphase definiert. Resultate: 15 Assistenzärzte führten 371 Sections durch. Bei der Operationszeit und der Induktion-Entbindung-Zeit war der steile Teil der Kurve nach 20 Sectiones überwunden. Für den Apgar-1-min-Wert und die Hospitalisationsdauer konnte ein geringer, bei den übrigen Parametern kein Lernprozess nachgewiesen werden. Schlussfolgerung: Für eine Sectio mit durchschnittlichem Risiko ist eine ausreichende Sicherheit nach 20 Eingriffen erreicht.
Gedeckte Uterusruptur nach zweimaligem Spontanpartus im Status nach Sectio caesarea bei der ersten Entbindung
Authors: Dannecker Christian , Hübener Christoph , Toth Bettina , Lienemann Andreas , Hepp Hermann , Hasbargen Uwe
Published: October 2003

Wir präsentieren den Fall einer nahezu asymptomatischen, gedeckten Uterusruptur nach zwei vaginalen Entbindungen im Zustand nach Sectio bei der ersten Entbindung. Eine Narbenruptur ist auch im Status nach Sectio ein seltenes Ereignis, was den vaginalen Geburtsversuch im Zustand nach Kaiserschnitt trotz des erhöhten Rupturrisikos rechtfertigt. Besondere Sicherheitsvorkehrungen bei der Geburtsleitung im Zustand nach Sectio gilt es jedoch zu beachten. Diese wurden von der ACOG und der AG für fetomaternale Medizin publiziert. In unserem Fall erfolgte die Diagnose einer Uterusruptur aufgrund einer vaginalsonographischen Untersuchung 7,5 Wochen nach unauffälligem Spontanpartus. Eine weiterführende Untersuchung mittels MRT erbrachte keinen wesentlichen zusätzlichen Informationsgewinn, weshalb sie nur in Ausnahmefällen indiziert sein wird. Ob eine routinemässige vaginalsonographische Untersuchung nach unauffälliger vaginaler Entbindung bei einem Kaiserschnitt in der Vorgeschichte zum Ausschluss einer Narbendehiszenz indiziert ist, sollte durch weitere Studien geklärt werden.
Efficacy of Acupuncture for the Treatment of Primary Dysmenorrhea
Authors: Habek Dubravko , Čerkez Habek Jasna , Bobić-Vuković Mirna , Vujić Bojana
Published: October 2003

Objective: The aim of this study was to evaluate the effect of acupuncture (AP) in the treatment of primary dysmenorrhea (PD). Methods: A clinical prospective, placebo-controlled trial included 57 women with PD. Of these, 30 were treated with manual AP points: Du 20 (Baihui), bilateral Li 4 (Hegu), Ren 3 (Zhongji), Ren 4 (Guanyuan), Ren 6 (Qihai), bilateral Gb 34 (Yanglingquan), bilateral Ub 23 (Shenshu), bilateral Lp 6 (Sanyinjao) and auriculoacupuncture points (Shenmen); 27 women were treated with placebo AP. AP treatments were considered successful if PD did not occur any more, medication of PD became unnecessary or PD symptoms did not occur for 2 years after the AP treatment. Results: The occurrence of PD in nulliparae was statistically relevant (p < 0.001). Statistically relevant was also the decrease in medication in women to whom AP had been applied (p < 0.0001), which was not the case in the placebo group (p > 0.5). Conclusions: The success rate of AP for the treatment of PD symptoms within 1 year after the AP treatment is 93.3% in the first group and 3.7% in the placebo group.
Aussergerichtliche Gutachten
Authors: Bass Giovanni
Published: October 2003

Aussergerichtliche Gutachten werden meist von Patientinnen in Auftrag gegeben, die durch eine vermeintliche oder effektive Sorgfaltspflichtverletzung des Arztes betroffen sind. Häufige Ursache des Problems ist eine ungenügende (präoperative) Aufklärung. Die Gutachten sind eine lehrreiche Fundgrube eventuell vermeidbarer Fehler. Die in vollständig anonymisierter Form publizierten Fälle sollen dazu dienen, diese Fehler nicht zu wiederholen. Es werden hier zwei postoperative Ereignisse vorgestellt und kommentiert: 1. Narbenhernien nach abdominaler Hysterektomie und 2. ein subphrenischer Abszess nach laparoskopischer Entfernung einer Dermoidzyste des Ovars.
Trinucleotide repeat instability: a hairpin curve at the crossroads of replication, recombination, and repair
Authors: Lenzmeier B.A. , Freudenreich C.H.
Published: October 2003

The trinucleotide repeats that expand to cause human disease form hairpin structures in vitro that are proposed to be the major source of their genetic instability in vivo. If a replication fork is a train speeding along a track of double-stranded DNA, the trinucleotide repeats are a hairpin curve in the track. Experiments have demonstrated that the train can become derailed at the hairpin curve, resulting in significant damage to the track. Repair of the track often results in contractions and expansions of track length. In this review we introduce the in vitro evidence for why CTG/CAG and CCG/CGG repeats are inherently unstable and discuss how experiments in model organisms have implicated the replication, recombination and repair machinery as contributors to trinucleotide repeat instability in vivo.
The contribution of cis-elements to disease-associated repeat instability: clinical and experimental evidence
Authors: Cleary J.D. , Pearson C.E.
Published: October 2003

Alterations in the length (instability) of gene-specific microsatellites and minisatellites are associated with at least 35 human diseases. This review will discuss the various cis-elements that contribute to repeat instability, primarily through examination of the most abundant disease-associated repetitive element, trinucleotide repeats. For the purpose of this review, we define cis-elements to include the sequence of the repeat units, the length and purity of the repeat tracts, the sequences flanking the repeat, as well as the surrounding epigenetic environment, including DNA methylation and chromatin structure. Gender-, tissue-, developmental- and locus-specific cis-elements in conjunction with trans-factors may facilitate instability through the processes of DNA replication, repair and/or recombination. Here we review the available human data that supports the involvement of cis-elements in repeat instability with limited reference to model systems. In diverse tissues at different developmental times and at specific loci, repetitive elements display variable levels of instability, suggesting vastly different mechanisms may be responsible for repeat instability amongst the disease loci and between various tissues.
Reactivation of silenced genes and transcriptional therapy
Authors: Chiurazzi P. , Neri G.
Published: October 2003

The purpose of this review is to discuss the potential role of “transcriptional therapy” to modulate the expression of target genes in order to treat monogenic as well as multifactorial disorders. In vitro and in vivo experiments with DNA demethylating and histone hyperacetylating drugs are currently performed in several laboratories on a variety of genes. In attempting to place these results into perspective, we divided the target genes into four major categories: (1) single genes with a hypermethylated CpG island; (2) single genes without a CpG island; (3) groups of genes silenced by aberrant DNA methylation; and (4) groups of genes silenced by lack of histone acetylation. We discuss the latest advances in the field of chromatin regulation and, in particular, the role of histone methylation and that of RNA interference in gene silencing. We can expect that in the future regulation of transcription will become an effective treatment for several genetic conditions.
Transcription defects induced by repeat expansion: fragile X syndrome, FRAXE mental retardation, progressive myoclonus epilepsy type 1, and Friedreich ataxia
Authors: Greene E. , Handa V. , Kumari D. , Usdin K.
Published: October 2003

Fragile X mental retardation syndrome, FRAXE mental retardation, Progressive myoclonus epilepsy Type I, and Friedreich ataxia are members of a larger group of genetic disorders known as the Repeat Expansion Diseases. Unlike other members of this group, these four disorders all result from a primary defect in the initiation or elongation of transcription. In this review, we discuss current models for the relationship between the expanded repeat and the disease symptoms.
Rare fragile sites
Authors: Sutherland G.R.
Published: October 2003

Rare folate-sensitive fragile sites are the archetypal trinucleotide repeats. Although the CAG repeat in the androgen receptor, associated with spinobulbar muscular atrophy, was the first to be published in 1991, it was the publication in the same year of the molecular basis of fragile X that focused much attention on trinucleotide repeat expansion as a mutational mechanism. A number of rare fragile sites have had their repeat elements characterised since that time. The so-called “folate-sensitive” fragile sites are likely to be all CCG repeat expansions similar to the fragile X. The folate insensitive fragile sites have more complex longer repeat elements. Only two rare fragile sites (FRAXA and FRAXE) are of unequivocal clinical significance in that they are associated with intellectual disability.
The rare human fragile site 16B
Authors: Felbor U. , Feichtinger W. , Schmid M.
Published: October 2003

The rare human fragile site 16B (FRA16B) has been found to occur spontaneously. Its expression in lymphocyte cultures can also be induced or greatly enhanced by addition of chemicals which are known to bind to AT-rich DNA regions. Following optimal treatment with 150 µg/ml berenil 24 h prior to fixation, the heterozygote frequency of FRA16B is found to be about 5% in populations of European descent. Thus, FRA16B represents the most common of the rare fragile sites. Consistent with cytogenetic observations, the molecular characterization of FRA16B revealed that it is an amplified 33-base pair AT-rich minisatellite repeat. These interindividually variable, extremely large repeat expansions of 15–70 kb in size do not seem to interfere with the expression of genes essential for human development since heterozygotes and homozygotes for FRA16B are normal.
Forgotten fragile sites and related phenomena
Authors: Sutherland G.R. , Baker E.
Published: October 2003

Fragile sites have been recognised since 1965. Extensive molecular characterisation of them has occurred in the last decade. Yet there are a number of interesting phenomena relating to fragile sites and similar lesions on chromosomes that have not been subject to recent published research. The aim of this short review is to stimulate interest in some of these aspects of fragile sites in the hope that a more complete picture of their nature and properties will emerge.
Common fragile sites
Authors: Arlt M.F. , Casper A.M. , Glover T.W.
Published: October 2003

Aphidicolin-induced common fragile sites are site-specific gaps or breaks seen on metaphase chromosomes after partial inhibition of DNA synthesis. These fragile sites were first recognized during the early studies of the fragile X syndrome and are induced by the same conditions of folate or thymidylate stress used to induce the fragile X site. Common fragile sites are normally stable in cultured human cells. However, following induction with replication inhibitors, they display a number of characteristics of unstable and highly recombinogenic DNA. From the many studies that have cloned and characterized fragile sites, it is now known that these sites extend over large regions, are associated with genes, exhibit late or delayed replication, and contain regions of high flexibility but are otherwise unremarkable in sequence. Studies showing that fragile sites and their associated genes are frequently deleted or rearranged in cancer cells have clearly demonstrated their importance in genome instability in tumorigenesis. Yet until recently, very little was known about the molecular mechanisms involved in their stability. Recent findings showing that the key checkpoint genes ATR and BRCA1 are critical for genome stability at fragile sites have shed new light on these mechanisms and on the biological significance of common fragile sites.