bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective effects of selected medicinal plants against protein degradation, lipid peroxidation and deformability loss of oxidatively stressed human erythrocytes
Authors: Suboh S. M. , Bilto Y. Y. , Aburjai T. A. 
Published: May 2004

AbstractThe effects of seven medicinal plants including Artemisia herba‐alba, Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium, Trigonella foenum‐graecum, and Allium sativum on protein degradation, lipid peroxidation, erythrocyte deformability and osmotic fragility of erythrocytes exposed in vitro to 10 mM H2O2 for 60 min at 37 °C have been examined. Preincubation of erythrocytes with Nigella sativa and Allium sativum protected erythrocytes against protein degradation, loss of deformability and increased osmotic fragility caused by H2O2, while the other plants failed to protect erythrocytes against these damages. Artemisia herba‐alba did not protect erythrocytes against lipid peroxidation, while Trigonella foenum‐graecum unexpectedly increased lipid peroxidation of erythrocytes exposed to H2O2. Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium and Allium sativum protected erythrocytes against lipid peroxidation. The results indicate the importance of oxidatively damaged cellular proteins in compromising the rheologic behaviour of the erythrocytes, and that the medicinal plants which have anti‐protein‐oxidant activity (e.g. Nigella sativa and Allium sativum) could be rheologically useful, particularly in pathological conditions related to free radicals. Copyright © 2004 John Wiley & Sons, Ltd.
Ultrastructural changes in the testis and epididymis of rats following treatment with the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya
Authors: Manivannan B. , Mishra P. K. , Pathak N. , Sriram S. , Bhande S. S. , Panneerdoss S. , Lohiya N. K. 
Published: May 2004

AbstractThe benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya at a dose of 10 mg/rat/day for 150 days, which has shown a total inhibition of motility, reduced sperm count and infertility, was tested to deﬁne the mode of action at the subcellular level in the testis and epididymis. The ultrastructure of the testis of the treated animals revealed no appreciable changes in the subcellular characteristics. The mechanism of protein synthesis as well as steroidogenesis were evident in the Sertoli cells while the spermatogonia, spermatocytes and spermatids, both round and elongated, depicted a prominent nucleus, distinct nuclear membrane and cytoplasmic characteristics indicating normal germ cell differentiation. The principal cells of the cauda epididymis were characterized by the presence of well‐deﬁned rough endoplasmic reticulum, mitochondria, Golgi bodies and secretary granules, suggesting active secretory functions. The absorptive function of the cauda epididymis was evidenced by the presence of numerous vesicles and multivesicular bodies adjacent to stereocilia. It is concluded that the inhibition of sperm motility by the drug could be due to other epididymal factors rather than the subcellular characteristics of testis and epididymis. Copyright © 2004 John Wiley & Sons, Ltd.
Neuropharmacological proﬁle of hydroalcohol extract of Valeriana edulis ssp. procera roots in mice
Authors: Oliva Iván , González‐Trujano Ma. Eva , Arrieta Jesús , Enciso‐Rodríguez Roberto , Navarrete Andrés 
Published: May 2004

AbstractValerian is the common name given to the crude drug consisting of the underground organs of the species Valeriana. Valeriana edulis ssp. procera Meyer is the Mexican valerian. The aim of the present work was to elucidate the neuropharmacological proﬁle of a hydroalcohol extract of Valeriana edulis roots at doses of 100, 300 and 1000 mg/kg in several experimental models. A dose‐dependent anticonvulsant and anxiolytic‐like effect of V. edulis was demonstrated. In addition, the extract decreased rotarod performance and traction force and prolonged the pentobarbital‐induced sleeping time at high doses. Concomitant administration of valerian extract and pentobarbital showed a synergistic effect on motor coordination and traction force in mice. The anxiolytic‐like effect of V. edulis was compared with diazepam and with diphenhydramine and doxylamine, the latter in order to consider the H1‐antihistamine effect as another possibility to explain, at least in part, the central nervous system depressant effect of valerian. These results also underlie the medical and industrial use of this species and allowed the conclusion that the extract of V. edulis has central nervous depressant properties similar to, but with some differences to V. ofﬁcinalis, a very well known species. Copyright © 2004 John Wiley & Sons, Ltd.
Kava treatment in patients with anxiety
Authors: Geier F. P. , Konstantinowicz T. 
Published: May 2004

AbstractIn several clinical trials, mainly conducted with a dose of 300 mg kava extract per day, kava has been employed successfully for the treatment of anxiety disorders.The goal of the placebo‐controlled double‐blind outpatient trial was to obtain more information on the dosage range and efﬁcacy of a kava special extract WS 1490 in patients with non‐psychotic anxiety. 50 patients were treated with a daily dose of 3 × 50 mg WS 1490 during a 4‐week treatment period followed by a 2‐week safety observation phase.In the active treatment group, the total score of the Hamilton anxiety scale (primary efﬁcacy variable), showed a therapeutically relevant reduction in anxiety versus placebo (more than 4 points). In the secondary variables studied, HAMA ‘somatic and psychic anxiety’ subscales, the Erlangen anxiety, tension and aggression scale (EAAS), the brief personality structure scale (KEPS), the adjective checklist (EWL 60‐S) and clinical global impressions scale (CGI), a trend in favour of the active treatment was detectable. WS 1490 was well tolerated and showed a safety proﬁle with no drug‐related adverse events or post‐study withdrawal symptoms.It can be concluded that the applied 150 mg WS 1490 per day is an effective and safe treatment of non‐psychotic anxiety syndromes in the described population. Copyright © 2004 John Wiley & Sons, Ltd.
Ferulic acid alleviates lipid peroxidation in diabetic rats
Authors: Balasubashini M. Sri , Rukkumani R. , Viswanathan P. , Menon Venugopal P. 
Published: May 2004

AbstractDiabetes mellitus is a metabolic disorder associated with increased formation of free radicals. The objective of our study was to determine whether ferulic acid (FA), a phenolic acid, has any role to play in diabetes induced free radical formation. Diabetes was induced with streptozotocin. The levels of blood glucose, thiobarbituric acid reactive substances (TBARS), hydroperoxides and free fatty acids (FFA) increased in the liver of diabetic animals. The activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) decreased in the liver. Histopathology of pancreas also shows shrunken islets. Supplementation of FA to the diabetic rats resulted in a decrease in the levels of glucose, TBARS, hydroperoxides, FFA and an increase in reduced glutathione (GSH). FA also resulted in increased activities of SOD, CAT, GPx and expansion of pancreatic islets. The effect was much pronounced with lower dose treatment. Thus our study shows that administration of ferulic acid helps in enhancing the antioxidant capacity of these diabetic animals by neutralizing the free radicals formed thereby reducing the intensity of diabetes. Copyright © 2004 John Wiley & Sons, Ltd.
Butyryl‐ and acetyl‐cholinesterase inhibitory activities in essential oils of Salvia species and their constituents
Authors: Savelev Sergey U. , Okello Edward J. , Perry Elaine K. 
Published: May 2004

AbstractExtracts of Salvia (sage) species have been reported to have cholinergic activities relevant to the treatment of Alzheimer's disease. A lack of information on the inhibition of the enzyme butyrylcholinesterase, also considered to be a target in the treatment of the disease, prompted this in vitro investigation of the essential oils of S. fruticosa, S. lavandulaefolia, S. ofﬁcinalis and S. ofﬁcinalis var. purpurea for anti‐butyrylcholinesterase activity.Dose‐dependent inhibition of human cholinesterases by the extracts and constituents was determined using the method of Ellman. A time dependent increase in the inhibition of butyrylcholinesterase by the oils of S. fruticosa and S. ofﬁcinalis var. purpurea was evident. IC50 values decreased from 0.15 ± 0.007 and 0.14 ± 0.007 mg/mL after 5 min to 0.035 ± 0.016 and 0.06 ± 0.018 mg/mL after 90 min incubation time respectively. The slow onset of inhibition of butyrylcholinesterase was also shown by individual constituents, such as 3‐carene and β‐pinene. Analyses of the chemical composition of the oils and anti‐butyrylcholinesterase activity of their constituents revealed that none of the compounds tested would account for the total activity of the oils and that synergy is likely. Copyright © 2004 John Wiley & Sons, Ltd.
Protective effect of water yam (Dioscorea alata L.) extract on the copper‐driven fenton reaction and X‐ray induced DNA damage in vitro
Authors: Wang Tsu‐Shing , Liang Shih‐Jyue , Lii Chong‐Kuei , Liu Sin‐Yie 
Published: May 2004

AbstractThe rhizome extract of Dioscorea has been shown to possess radical scavenging activity. In this study, the protective effect of water yam (Dioscorea alata L.) rhizome extract on calf thymus DNA and plasmid DNA strand breakage by the copper‐driven Fenton reaction and X‐irradiation was examined. The protective activity in vitro of four lyophilized extracts obtained from yam rhizomes: (1) aqueous extract (YAE); (2) 30% ethanolic extract (YEE); (3) aqueous extract boiled for 30 min (BYAE); and (4) 30% ethanolic extract boiled for 30 min (BYEE) were evaluated by ethidium bromide binding assay and DNA nicking assay. The YAE, YEE, and BYEE effectively inhibited the copper‐driven Fenton reaction‐induced damage of calf thymus DNA, while inhibition was less pronounced in the case of X‐ray induced strand breakage of plasmid DNA. While BYAE potently inhibited X‐ray induced strand breaks in plasmid pGL3 DNA, it failed to inhibit, and even greatly enhanced copper‐H2O2 induced damage of calf thymus DNA. The present results demonstrate strong copper chelating and weak hydroxyl radical scavenging activities in yam rhizome extracts, and these activities may vary depending on the procedures used in preparing the extract. Copyright © 2004 John Wiley & Sons, Ltd.
Magnetic interactions in nonalternant mixed molecular radical crystals and mixed ion radical crystals
Authors: Minkov I. , Tadjer A. 
Published: May 2004

AbstractThe character and the magnitude of magnetic interaction in 1‐D stacks of mixed molecular radical crystals (MMRCs) and mixed molecular ion radical crystals (MMIRCs) of alternant aromatic hydrocarbons have already been studied theoretically. In this work nonalternant 1‐D stacks built of π‐electronic subunits are considered. Some of the elementary units are singly or doubly charged (MMIRCs), others are neutral (MMRCs); alternant and nonalternant subunits are used as building blocks. Qualitative investigations based on the band theory of exchange effects in solid organic open‐shell systems are carried out. The contributions to the effective exchange integral Jeff: direct (Hund's), kinetic and indirect, are calculated. Structures of 1:1 MMRCs and MMIRCs with positive value of the integral Jeff, accounting for the spin exchange of the electrons in the half‐filled band, i.e., with ferromagnetic ground state, are suggested. The influence of different parameters (molecular size, presence of heteroatoms, localization versus delocalization, alternant versus nonalternant, charge, etc.) on the magnitude of the net exchange is discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Confidence intervals for the effect of a prognostic factor after selection of an ‘optimal’ cutpoint
Authors: Holländer Norbert , Sauerbrei Willi , Schumacher Martin 
Published: May 2004

AbstractWhen investigating the effects of potential prognostic or risk factors that have been measured on a quantitative scale, values of these factors are often categorized into two groups. Sometimes an ‘optimal’ cutpoint is chosen that gives the best separation in terms of a two‐sample test statistic. It is well known that this approach leads to a serious inflation of the type I error and to an overestimation of the effect of the prognostic or risk factor in absolute terms. In this paper, we illustrate that the resulting confidence intervals are similarly affected. We show that the application of a shrinkage procedure to correct for bias, together with bootstrap resampling for estimating the variance, yields confidence intervals for the effect of a potential prognostic or risk factor with the desired coverage. Copyright © 2004 John Wiley & Sons, Ltd.
Controlling the risk of spurious findings from meta‐regression
Authors: Higgins Julian P. T. , Thompson Simon G. 
Published: May 2004

AbstractMeta‐regression has become a commonly used tool for investigating whether study characteristics may explain heterogeneity of results among studies in a systematic review. However, such explorations of heterogeneity are prone to misleading false‐positive results. It is unclear how many covariates can reliably be investigated, and how this might depend on the number of studies, the extent of the heterogeneity and the relative weights awarded to the different studies. Our objectives in this paper are two‐fold. First, we use simulation to investigate the type I error rate of meta‐regression in various situations. Second, we propose a permutation test approach for assessing the true statistical significance of an observed meta‐regression finding. Standard meta‐regression methods suffer from substantially inflated false‐positive rates when heterogeneity is present, when there are few studies and when there are many covariates. These are typical of situations in which meta‐regressions are routinely employed. We demonstrate in particular that fixed effect meta‐regression is likely to produce seriously misleading results in the presence of heterogeneity. The permutation test appropriately tempers the statistical significance of meta‐regression findings. We recommend its use before a statistically significant relationship is claimed from a standard meta‐regression analysis. Copyright © 2004 John Wiley & Sons, Ltd.
A simple approach to power and sample size calculations in logistic regression and Cox regression models
Authors: Væth Michael , Skovlund Eva 
Published: May 2004

AbstractFor a given regression problem it is possible to identify a suitably defined equivalent two‐sample problem such that the power or sample size obtained for the two‐sample problem also applies to the regression problem. For a standard linear regression model the equivalent two‐sample problem is easily identified, but for generalized linear models and for Cox regression models the situation is more complicated. An approximately equivalent two‐sample problem may, however, also be identified here. In particular, we show that for logistic regression and Cox regression models the equivalent two‐sample problem is obtained by selecting two equally sized samples for which the parameters differ by a value equal to the slope times twice the standard deviation of the independent variable and further requiring that the overall expected number of events is unchanged. In a simulation study we examine the validity of this approach to power calculations in logistic regression and Cox regression models. Several different covariate distributions are considered for selected values of the overall response probability and a range of alternatives. For the Cox regression model we consider both constant and non‐constant hazard rates. The results show that in general the approach is remarkably accurate even in relatively small samples. Some discrepancies are, however, found in small samples with few events and a highly skewed covariate distribution. Comparison with results based on alternative methods for logistic regression models with a single continuous covariate indicates that the proposed method is at least as good as its competitors. The method is easy to implement and therefore provides a simple way to extend the range of problems that can be covered by the usual formulas for power and sample size determination. Copyright © 2004 John Wiley & Sons, Ltd.
Controlling test case explosion in test generation from B formal models
Authors: Legeard Bruno , Peureux Fabien , Utting Mark 
Published: May 2004

AbstractBZ‐TESTING‐TOOLS (BZ‐TT) is a tool set for automated test case generation from B and Z specifications. BZ‐TT uses boundary and cause–effect testing on the basis of the formal model. It has been used and validated on several industrial applications in the domain of critical software, particularly smart card and transport systems. This paper presents the test coverage criteria supported by BZ‐TT. On the one hand, these correspond to various classical structural coverage criteria, but specialized to the case of B abstract machines. The paper gives algorithms for these in Prolog. On the other hand, BZ‐TT introduces new coverage criteria for complex data structures, based on boundary analysis: this paper defines weak and strong state‐boundary coverage, input‐boundary coverage and output‐boundary coverage. Finally, the paper describes how BZ‐TT presents a unified view of these criteria to the validation engineer, and allows him or her to control the test case explosion on a coarse basis (choosing from a range of coverage criteria) as well as a fine basis (selecting options for each state or input variable). Copyright © 2004 John Wiley & Sons, Ltd.
Decision Making with Uncertain Information: Learning from Women in a High Risk Breast Cancer Clinic
Authors: Frost Caren J. , Venne Vickie , Cunningham Dianne , Gerritsen‐McKane Ruth 
Published: May 2004

AbstractPatients and practitioners may believe that clinically validated laboratory tests provide definitive information. Genetic counselors know this is not always so, and the possibility of inconclusive genetic test results is often discussed in the pretest counseling session. This added discussion topic prolongs the process of genetic counseling, but if there is inadequate patient understanding, patient frustration may be high when receiving a result of uncertain significance, and patients may make decisions about subsequent medical management based on incorrect assumptions. For patients/participants in a research setting, where the clinical validity of testing may be unclear, some patients/participants may still want to use test results to influence their medical management. This paper presents findings from a qualitative study wherein 15 women from the High Risk Breast Cancer Clinic at Utah's Huntsman Cancer Institute discussed how uncertainty regarding results affected their decision making. The women were randomly selected from 3 categories—women with test results of uncertain significance; women without cancer who have a mutation; and women who are members of high‐risk families, but for whom no mutation was found. Study findings will be used in future studies to better understand how to improve communication regarding uncertain results, especially in a research environment.
Pathway Miner: extracting gene association networks from molecular pathways for predicting the biological significance of gene expression microarray data
Authors: Pandey Ritu , Guru Raghavendra K. , Mount David W. 
Published: May 2004

Abstract
Summary: We have developed a web-based system (Pathway Miner) for visualizing gene expression profiles in the context of biological pathways. Pathway Miner catalogs genes based on their role in metabolic, cellular and regulatory pathways. A Fisher exact test is provided as an option to rank pathways. The genes are mapped onto pathways and gene product association networks are extracted for genes that co-occur in pathways. The networks can be filtered for analysis based on user-selected options.
Availability: Pathway Miner is a freely available web accessible tool at http://www.biorag.org/pathway.html
ClutrFree: cluster tree visualization and interpretation
Authors: Bidaut Ghislain , Ochs Michael F. 
Published: May 2004

Abstract
Summary: ClutrFree facilitates the visualization and interpretation of clusters or patterns computed from microarray data through a graphical user interface that displays patterns, membership information of the genes and annotation statistics simultaneously. ClutrFree creates a tree linking the patterns based on similarity, permitting the navigation among patterns identified by different algorithms or by the same algorithm with different parameters, and aids the inferring of conclusions from a microarray experiment.
Availability: The ClutrFree Java source code and compiled bytecode are available as a package under the GNU General Public License at http://bioinformatics.fccc.edu
Supplementary information: Extended documentation on the software usage, as well as supplemental figures and an appropriate test dataset are provided on the website.
Exhaustive whole-genome tandem repeats search
Authors: Krishnan Arun , Tang Francis 
Published: May 2004

Abstract
Motivation: Approximate tandem repeats (ATR) occur frequently in the genomes of organisms, and are a source of polymorphisms observed in individuals, and thus are of interest to those studying genetic disorders. Though extensive work has been done in order to identify ATRs, there are inherent limitations with the current approaches in terms of the number of pattern sizes that can be searched or the size of the input length.
Results: This paper describes (1) a new algorithm which exhaustively finds all variable-length ATRs in a genomic sequence and (2) a precise description of, and an algorithm to significantly reduce, redundancy in the output. Our ATR definition is parameterized by a mismatch ratio p which allows for more mismatches in longer tandem repeats (and fewer in shorter). Furthermore, our algorithm is embarrassingly parallel and thus can attain near-linear speed-up on Beowulf clusters. We present results of our algorithm applied to sequences of widely differing lengths (from genes to chromosomes).
Availability: Source and binaries are available on request.
Supplementary information: http://web.bii.a-star.edu.sg/~francis/Research/Exhaustive/
Mining gene expression data for positive and negative co-regulated gene clusters
Authors: Ji Liping , Tan Kian-Lee 
Published: May 2004

Abstract
Motivation: Analysis of gene expression data can provide insights into the positive and negative co-regulation of genes. However, existing methods such as association rule mining are computationally expensive and the quality and quantities of the rules are sensitive to the support and confidence values. In this paper, we introduce the concept of positive and negative co-regulated gene cluster (PNCGC) that more accurately reflects the co-regulation of genes, and propose an efficient algorithm to extract PNCGCs.
Results: We experimented with the Yeast dataset and compared our resulting PNCGCs with the association rules generated by the Apriori mining algorithm. Our results show that our PNCGCs identify some missing co-regulations of association rules, and our algorithm greatly reduces the large number of rules involving uncorrelated genes generated by the Apriori scheme.
Availability: The software is available upon request.
Supplementary information: Supplementary tables and figures for this paper can be found at http://www.comp.nus.edu.sg/~jiliping/p1.html