bluuebunny/crossref_metadata_2025 huggingface dataset:
On the irrelevance of electrostatics for the crystal structures and polymorphism of long even n‐alkanes
Authors: Van de Streek Jacco , Verwer Paul , Bennema Piet , Vlieg Elias
Published: August 2002

It is known that the experimental triclinic crystal structures of even n‐alkanes are not well reproduced upon energy minimization with current force fields. The inclusion of electrostatics does not solve this, and, moreover, some charge schemes show unphysical features such as positively charged carbon atoms or charge alternation. The effect of the electrostatics on the energies of the crystal structures of the even n‐alkanes, and thereby on their polymorphism, has never been established. A new charge scheme is introduced that yields physically sensible charges without constraints. It will also be shown, however, that electrostatics are relevant neither for the structures of the crystals, nor for their energies. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 365–370, 2002
Parametrization of the Becke3‐LYP hybrid functional for a series of small molecules using quantum molecular similarity techniques
Authors: Poater Jordi , Duran Miquel , Solà Miquel
Published: August 2002

The a0, ax, and ac semiempirical parameters of the original Becke three‐parameter method have been optimized by minimizing the difference between the density given by this method and the singles and doubles quadratic configuration interaction (QCISD) generalized density using quantum molecular similarity measures. The optimization is performed including the hybrid energy functional in a self‐consistent fashion and employing the relaxed geometry at each set of a0, ax, and ac parameters. This method has been applied to a series of 16 small molecules with different bonding patterns. Results show that, at least in diatomic molecules, it is possible to obtain a set of parameters that reproduces almost exactly the QCISD electron density. The optimized parameters for the studied molecules follow two main general trends: (a) the parameters governing the amount of gradient corrections for exchange and correlation have similar values (ac≈ax); and (b) the larger the exact exchange included, the smaller the gradient correction for exchange needed (a0≈1−ax). Especially interesting are the values obtained for the a0 parameter, which reflect how much exact exchange should be included in the description of a particular system. Finally, for H2 and LiH, we have carried out a search for other possible local minima on the quadratic error integral surface concluding that for these molecules there is not a unique set of parameters that produces a B3LYP density of QCISD quality. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1666–1678, 2001
Artificial neural networks applied for studying metallic complexes
Authors: de Viterbo V. D. , Belchior J. C.
Published: August 2002

Metallic complexes of multimetal and multiligand systems are complicated for calculating equilibrium concentrations in solutions. An artificial neural network has been developed for studying Al3+ and EDTA complexes in solution with an initial concentration of 0.01 mol L−1 for these species. In this system there are 20 compounds and may exist 18 simultaneous reactions. The neural network has been trained and the simulated data of different concentrations as a function of pH are predicted with an accuracy of about 1% for all species simultaneously. A general analytical formula is presented, which directly relates all the concentrations as a function of pH. The analysis showed that predictions closer to the boundary of the input and output data are quantitative while out of these limits these are not even qualitative. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1691–1701, 2001
Localization function study of excitation processes in a set of small isoelectronic molecules
Authors: Chesnut D. B.
Published: August 2002

Electron localization function (ELF) theory is used to characterize changes that occur upon excitation from ground singlet to first excited triplet states in a series of isoelectronic 16‐electron molecules including H2CCH2, HNCH2, H2CO, HNNH, HNO, and O2 (ground triplet to excited singlet). ELF allows one to visualize lone pair or nonbonding electrons, and in these cases the π→π* or n→π excitation processes involved lead to an effective 90° rotation of the electronic structure about one heavy atom center and consequent distortion towards pyramidal symmetry about both heavy atom centers. The heavy atom bond lengths change very little in those cases where effectively two‐center three‐electron bonds can be formed (HNNH, HNO, and O2) while a significant lengthening occurs in those cases where hydrogen atoms prevent such interactions (H2CCH2, HNCH2, and H2CO). It is shown that both ELF basin populations and atoms‐in‐molecules (AIM) delocalization indices reflect expected bond orders for conventional single and double bonds provided one compares the ratio of the molecular quantities rather than their absolute magnitudes. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1702–1711, 2001
Docking of small ligands to low‐resolution and theoretically predicted receptor structures
Authors: Wojciechowski Marek , Skolnick Jeffrey
Published: August 2002

We have developed a simple docking procedure that is able to utilize low‐resolution models of proteins created by structure prediction algorithms such as threading or ab initio folding to predict the conformation of receptor–small ligand complexes. In our approach, using only approximate, discretized models of both molecules, we search for the steric and quasi‐chemical complementarity between a ligand and the receptor molecules. This averaging procedure allows for the compensation of numerous structural inaccuracies resulting from the theoretical predictions of the receptor structure. The best relative orientation of these two models is obtained by an exhaustive scan over the rigid body's six‐dimensional translational and rotational degrees of freedom. The search method is based on a real space grid‐searching algorithm, unlike docking methods based on the fast Fourier Transform algorithm. We have applied this algorithm to rebuild structures of several complexes available in the Protein Data Bank. The structures of the receptors are produced by means of our threading algorithm PROSPECTOR, subsequently refined, and then utilized in the docking experiment. In many cases, not only is the localization of the binding site on the receptor surface correctly identified, but the proper orientation of the bounded ligand is also reasonably well reproduced within the level of accuracy of the modeled receptor itself. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 189–197, 2002
A complete classification of (12,4,3)‐RBIBDs
Authors: Morales Luis B. , Velarde Carlos
Published: August 2002

Using a parallel class by parallel class backtracking algorithm we classify (12,4,3)‐RBIBDs. The size of the search space is reduced by combinatorial arguments. Five nonisomorphic RBIBDs are found and listed. © 2001 John Wiley & Sons, Inc. J Combin Designs 9: 385–400, 2001
Heart rate variability as an outcome measure for Thought Field Therapy in clinical practice
Authors: Pignotti Monica , Steinberg Mark
Published: August 2002

The need for empirical, objective, clear, and practical outcome measures for therapy has long been recognized by clinicians and researchers. Pragmatic tools for objective determination of the efficacy of therapy have been scarce in clinical practice settings. Heart rate variability (HRV) is increasing in popularity for use in clinical settings as a measure of treatment success. Since HRV is stable and placebo‐free, it has the potential to meet this need. Thirty‐nine cases are presented from the clinical practices of the authors and three other clinicians where HRV was used as an outcome measure for Thought Field Therapy (TFT). The cases included TFT treatments which addressed a wide variety of problems including phobias, anxiety, trauma, depression, fatigue, attention deficit hyperactivity disorder, learning difficulties, compulsions, obsessions, eating disorders, anger, and physical pain. A lowering of subjective units of distress was in most cases related to an improvement in HRV. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1193–1206, 2001.
Coping, meaning in life, and suicidal manifestations: Examining gender differences
Authors: Edwards Melanie J. , Holden Ronald R.
Published: August 2002

Life meaning and coping strategies were investigated as statistical predictors of suicidal manifestations in a sample of 298 university undergraduates. Participants completed measures of hopelessness, sense of coherence, purpose in life, coping for stressful situations, suicide ideation, prior suicide attempts, and self‐reported likelihood of future suicidal behavior. Moderated multiple regression techniques examined the incremental validity of life meaning by coping interactions for predicting each suicide variable separately by gender. The interaction of sense of coherence and emotion‐oriented coping made a unique, significant contribution to the statistical prediction of all suicide variables for women. For men, the interaction between sense of coherence and emotion‐oriented coping contributed significantly to the statistical prediction of suicide ideation. All interactions remained significant when hopelessness was statistically controlled. The hypothesis that life meaning acts as a buffer between coping style and suicidal manifestations was partially supported. Implications for suicide prevention and intervention are discussed. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1517–1534, 2001.
Morphine inhibits indolactam V‐induced U937 cell adhesion and gelatinase secretion
Authors: Weeks Benjamin S. , Goldman Steven , Touma Salwa , Payne Malique , Cadet Patrick , Stefano George B.
Published: August 2002

We demonstrate that indolactam V, a non‐phorbol protein kinase C activator, promotes U937 cell attachment to fibronectin, type IV collagen and laminin. In the absence of indolactam V, 2–4% of U937 cells attach to all test substrates, however, in the presence of 100 nM indolactam V, 25, 16 and 11% of U937 cells attach to fibronectin, type IV collagen and laminin, respectively. When added concomitantly, 90 μM H‐7, a protein kinase C inhibitor, reduces indolactam V‐induced U937 cell adhesion to fibronectin by 91%. Monoclonal antibodies directed against both the β1 and α5 integrin subunits inhibit indolactam V‐induced U937 cell adhesion to fibronectin by 62 and 52%, respectively. Indolactam V also promotes homotypic aggregation in U937 cells, which is blocked with either anti‐ICAM or anti‐LFA‐1 antibodies. In addition, indolactam V promotes U937 cell secretion of a 92 kDa gelatinase as demonstrated by zymography. In the presence of low levels of morphine (10 nM–1.0 μM), the U937 cell attachment to matrix proteins was not significantly affected. However, in the presence of 10 μM morphine, the indolactam V treated cells exhibit a 71–74% reduction in cell adhesion to the matrix proteins. Further, 10 μM morphine also blocks indolactam V‐induced homotypic aggregation and gelatinase secretion. The inhibitory effect of morphine on cell‐matrix adhesion and gelatinase secretion was not inhibited by the opiate receptor antagonist naloxone (1 μM). While 10 μM naloxone did partially counteract the effect of 10 μM morphine on U937 cell attachment, this effect was likely non‐specific since 10 μM naloxone alone increased cell adhesion. Supporting this conclusion, PCR analysis revealed that U937 cells do not express the μ high affinity morphine receptor. Also, indolactam V did not induce μ receptor expression, suggesting that morphine acts on U937 cells in a non‐specific fashion. © 2001 Wiley‐Liss, Inc.
Human T cell leukemia virus type I and neurologic disease: Events in bone marrow, peripheral blood, and central nervous system during normal immune surveillance and neuroinflammation
Authors: Grant Christian , Barmak Kate , Alefantis Timothy , Yao Jing , Jacobson Steven , Wigdahl Brian
Published: August 2002

Human T cell lymphotropic/leukemia virus type I (HTLV‐I) has been identified as the causative agent of both adult T cell leukemia (ATL) and HTLV‐I‐associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the exact sequence of events that occur during the early stages of infection are not known in detail, the initial route of infection may predetermine, along with host, environmental, and viral factors, the subset of target cells and/or the primary immune response encountered by HTLV‐I, and whether an HTLV‐I‐infected individual will remain asymptomatic, develop ATL, or progress to the neuroinflammatory disease, HAM/TSP. Although a large number of studies have indicated that CD4+ T cells represent an important target for HTLV‐I infection in the peripheral blood (PB), additional evidence has accumulated over the past several years demonstrating that HTLV‐I can infect several additional cellular compartments in vivo, including CD8+ T lymphocytes, PB monocytes, dendritic cells, B lymphocytes, and resident central nervous system (CNS) astrocytes. More importantly, extensive latent viral infection of the bone marrow, including cells likely to be hematopoietic progenitor cells, has been observed in individuals with HAM/TSP as well as some asymptomatic carriers, but to a much lesser extent in individuals with ATL. Furthermore, HTLV‐I+ CD34+ hematopoietic progenitor cells can maintain the intact proviral genome and initiate viral gene expression during the differentiation process. Introduction of HTLV‐I‐infected bone marrow progenitor cells into the PB, followed by genomic activation and low level viral gene expression may lead to an increase in proviral DNA load in the PB, resulting in a progressive state of immune dysregulation including the generation of a detrimental cytotoxic Tax‐specific CD8+ T cell population, anti‐HTLV‐I antibodies, and neurotoxic cytokines involved in disruption of myelin‐producing cells and neuronal degradation characteristic of HAM/TSP. J. Cell. Physiol. 190: 133–159, 2002. © 2002 Wiley‐Liss, Inc.
Obesity modulates the expression of haptoglobin in the white adipose tissue via TNFα
Authors: Chiellini Chiara , Bertacca Anna , Novelli Silvia E. , Görgün Cem Z. , Ciccarone Annamaria , Giordano Antonio , Xu Haiyan , Soukas Alexander , Costa Mario , Gandini Daniele , Dimitri Roberto , Bottone Pietro , Cecchetti Paolo , Pardini Ennia , Perego Lucia , Navalesi Renzo , Folli Franco , Benzi Luca , Cinti Saverio , Friedman Jeffrey M. , Hotamisligil Gökhan S. , Maffei Margherita
Published: August 2002

Increase in adipose mass results in obesity and modulation of several factors in white adipose tissue (WAT). Two important examples are tumor necrosis factor α (TNFα) and leptin, both of which are upregulated in adipose tissue in obesity. In order to isolate genes differentially expressed in the WAT of genetically obese db/db mice compared to their lean littermates, we performed RNA fingerprinting and identified haptoglobin (Hp), which is significantly upregulated in the obese animals. Hp is a glycoprotein induced by a number of cytokines, LPS (Lipopolysaccharide), and more generally by inflammation. A significant upregulation of WAT Hp expression was also evident in several experimental obese models including the yellow agouti (/) Ay, ob/ob and goldthioglucose‐treated mice (10‐, 8‐, and 7‐fold, respectively). To identify the potential signals for an increase in Hp expression in obesity, we examined leptin and TNFα in vivo. Wild type animals treated with recombinant leptin did not show any alteration in WAT Hp expression compared to controls that were food restricted to the level of intake of the treated animals. On the other hand, Hp expression was induced in mice transgenically expressing TNFα in adipose tissue. Finally, a significant downregulation of WAT Hp mRNA was observed in ob/ob mice deficient in TNFα function, when compared to the ob/ob controls. These results demonstrate that haptoglobin expression in WAT is increased in obesity in rodents and TNFα is an important signal for this regulation. J. Cell. Physiol. 190: 251–258, 2002. © 2002 Wiley‐Liss, Inc.
Angiotensin II type1 receptor regulation and differential trophic effects on rat cardiac myofibroblasts after acute myocardial infarction
Authors: Staufenberger Sibylle , Jacobs Martina , Brandstätter Katja , Hafner Mathias , Regitz‐Zagrosek Vera , Ertl Georg , Schorb Winfried
Published: August 2002

Fibroblast growth in the scar and surviving tissue is a key element of the remodeling post myocardial infarction. The regulation of fibroblast growth after acute myocardial infarction remains to be determined. Recently, Angiotensin II has been demonstrated to be a mitogen for neonatal cardiac fibroblasts. In this study adult rat cardiac fibroblasts were isolated from different regions of the infarcted rat heart and Angiotensin II effects examined. Adult Wistar‐rats were sham operated or left coronary artery ligated. After 4 days, hearts were removed and fibroblasts from sham operated, infarct‐ and non‐infarct regions of the left ventricle isolated. Radioligand binding studies were performed and cell number, cell area, total protein, and AT1 receptor mRNA after stimulation determined. Radioligand binding studies demonstrated that myofibroblasts expressed a single class of high affinity Angiotensin II AT1 receptors. Myofibroblasts from the infarct area revealed a lower maximal binding capacity, compared to sham operated myocardium. Conversely, myofibroblasts from the non‐infarct area had a higher expression of Angiotensin II AT1 receptor mRNA compared to sham operated myofibroblasts. Angiotensin II (1 μM, 48 h) increased cell‐number in sham operated and non‐infarct, but not in infarct myofibroblasts. Angiotensin II elevated total protein in sham operated, non‐infarct, and infarct myofibroblasts. In addition, Angiotensin II increased cell area in sham operated and infarct myofibroblasts. These data demonstrate that Angiotensin II acted as a mitogen in sham operated and non‐infarct myofibroblasts and stimulated hypertrophy in infarct myofibroblasts. These regional different effects of Angiotensin II might participate in the remodeling post myocardial infarction. © 2001 Wiley‐Liss, Inc.
Improvement of a fed‐batch process for high level xylanase production by aBacillusstrain
Authors: Schneider Gerhard , Strehaiano Pierre , Taillandier Patricia
Published: August 2002

In this paper, the improvement of a fed‐batch fermentation from the point of view of an industrial xylanase production process is described. TheBacillusstrain chosen for this study is able to produce high quantities of a xylanase that is suitable to be used as bleach boost agent in chlorine‐free bleaching sequences of paper pulp. It was found that xylo‐oligosaccharides (hydrolysis products from xylan by xylanase action) were indispensable for induction of the enzyme synthesis, but that their presence in quantities of only 0.1 g dm−3xylose equivalents led to catabolite repression. A substrate‐limited fed‐batch process, that is the most adapted, was furthermore improved with regard to nutrient requirement of the microorganism, especially the nitrogen source. A process with constant supply of a culture medium containing xylan, peptone and mineral nitrogen was able to produce 20 240 nkat cm−3with a productivity of 910 nkat cm−3 h−1, which places the process among the best ever reported.

© 2001 Society of Chemical Industry
In situ reactive extraction of lactic acid from fermentation media
Authors: Tik Nurcan , Bayraktar Emine , Mehmetoglu Ülkü
Published: August 2002

Extractive lactic acid fermentation was investigated in the presence of sunflower oil and Alamine‐336 (with oleyl alcohol as the diluent solvent). Lactic acid was produced in various media at 37 °C using Lactobacillus delbrueckii (NRRL‐B 445). First, the effects of oleyl alcohol (33.3%, v/v), immobilisation, and immobilisation in the presence of sunflower oil (5, 10, 15%, v/v) on lactic acid production were investigated. It was found that oleyl alcohol did not affect production while addition of sunflower oil increased lactic acid production from 10.22 to 16.46 gdm−3. On the other hand, a toxic effect was observed for oleyl alcohol solutions containing 15–50% (v/v) Alamine‐336. A maximum total lactic acid concentration of 25.59 gdm−3 was obtained when an oleyl alcohol solution containing 15% (v/v) Alamine together with immobilised cells with 15% (v/v) sunflower oil was used. This value was about 2.5 times that obtained from fermentation without organic solutions.

© 2001 Society of Chemical Industry
Biotechnology, Volume 8B, Biotransformations II, 2nd edn Edited by DR Kelly, Series Editors H‐J Rehm, G Reed, A Pühler and P Stadler, John Wiley & Sons Ltd, Chichester, UK, 2000, 533 pp, Price UK £175.00, ISBN 3527 283242
Authors: Bucke C
Published: August 2002

© 2001 Society of Chemical Industry
Comprehensive utilization of acidic wastewater from 3,3′‐dichlorobenzidine hydrochloride manufacture
Authors: Zhiqian Jia , Changqing Zhu , Qun Zhang , Huijuan Liu , Zhongzhou Liu , Jiuhul Qu , Dianpo Fu
Published: August 2002

In the commercial manufacture of 3,3′‐dichlorobenzidine hydrochloride, substantial quantities of acidic industrial effluents were generated. A combination of ultrafiltration and evaporation processes was investigated for the recovery of products and dilute hydrochloric acid. In a novel purification method, waste sulfuric acid is purified and reused four or five times in the hydrazobenzene–benzidine transformation step, resulting in a 75% reduction in the consumption of sulfuric acid, minimization of wastewater discharge and environmental hazards risk and significant economic, environmental and social benefits.

© 2001 Society of Chemical Industry
Ultrasound enhancement of dissolution kinetics of uranium oxides in supercritical carbon dioxide
Authors: Trofimov T I , Samsonov M D , Lee S C , Smart N G , Wai C M
Published: August 2002

The enhanced dissolution of uranium oxides by the application of ultrasound in supercritical fluid carbon dioxide containing dissolved 4,4‐trifluoro‐1‐(2‐thienyl)‐1,3‐butanedione and tributyl phosphate is demonstrated. Under conditions of 60 °C and 150 atm the steady state dissolution of UO3 with sonification is increased by approximately 100%. Furthermore, the effect of adding hydrogen peroxide to the supercritical system above enables the lower oxides of uranium, UO2 and U3O8, to be extracted.

© 2001 Society of Chemical Industry
Comparative study of the determination of platinum by extraction with Cyanex 923 and Cyanex 471X from bromide media
Authors: Duche Sharad N , Dhadke Purushottam M
Published: August 2002

The extraction equilibrium study of Pt(IV) was carried out with Cyanex 923 and Cyanex 471X in toluene from hydrobromic acid media to investigate their extraction capacity, since they have different donor atoms, ‘O’ and ‘S’. Their distribution equilibria were studied as a function of extractant concentration, diluents, hydrobromic acid concentration and the effect of temperature on extraction. Pt(IV) was quantitatively extracted with 0.1 mol dm−3 Cyanex 923 in toluene from 5.0–8.0 mol dm−3 HBr media and was stripped with 4.0 mol dm−3 perchloric acid. However it was also quantitatively extracted with 0.1 mol dm−3 Cyanex 471X (with 0.1 mol dm−3SnCl2) in toluene from 6.0–8.0 mol dm−3 HBr media and was stripped with 1.0 mol dm−3 stabilized sodium thiosulfate solution at pH 9.0. The slope analysis method indicated metal complex species of 1:1 for Pt(IV) with Cyanex 923 and Cyanex 471X in toluene from HBr media. These methods were successfully applied to the analysis of platinum in real samples.

© 2001 Society of Chemical Industry
Sonographic appearance of an appendiceal diverticulum
Authors: Konen Osnat , Edelstein Evgeny , Osadchi Alexandra , Shapiro Myra , Rathaus Valeria
Published: August 2002

The increasing use of sonography for evaluating acute abdomen has brought greater recognition of appendicular abnormalities. We present an incidental finding of an appendiceal diverticulum during a sonographic examination of a 4‐year‐old child with acute appendicitis. Abdominal sonography showed an enlarged, swollen appendix with a diam‐eter of 1.1 cm and a small, fingerlike lateral projection approximately 2.0 cm from its tip. The specimen, re‐sected during an appendectomy, was 5.5 cm long and 1.0 cm in diameter and had a 0.3‐cm outpouching. Microscopic examination revealed a pseudodiverticulum composed of mucosa and muscularis mucosa. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:45–47, 2002.
Comparison of sonography and MRI for diagnosing epicondylitis
Authors: Miller Theodore T. , Shapiro Micheal A. , Schultz Elizabeth , Kalish Paul E.
Published: August 2002

Purpose

The aim of this prospective study was to compare the sensitivity and specificity of sonography with those of MRI in evaluating epicondylitis.

Methods

The affected elbows of 11 patients with suspected epicondylitis were examined sonographically, and the contralateral (normal) elbow was also examined for comparison. In 10 of these patients, the affected elbow was also examined with MRI. In addition, both elbows of 6 volunteers without epicondylitis were examined sonographically; 1 elbow of each volunteer was designated as the ``test'' elbow and was examined with MRI. The sonograms of the patients' affected elbows and the volunteers' test elbows were paired with the sonograms of the contralateral elbows for comparison and were randomly shown twice to 2 readers. These readers, working independently and without knowledge of the findings of MRI, were instructed to state whether each elbow was normal or affected by epicondylitis. The MRI scans were then shown to the readers for similar review.

Results

Sonographic features of epicondylitis included outward bowing of the common tendon, presence of hypoechoic fluid subadjacent to the common tendon, thickening, decreased echogenicity, and ill‐defined margins of the common tendon. Sensitivity for detecting epicondylitis ranged from 64% to 82% for sonography and from 90% to 100% for MRI. Specificity ranged from 67% to 100% for sonography and from 83% to 100% for MRI.

Conclusions

Sonography is as specific but not as sensitive as MRI for evaluating epicondylitis. Used as an initial imaging tool, sonography might be adequate for diagnosing this condition in many patients, thus allowing MRI to be reserved for patients with symptoms whose sonographic findings are normal. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:193–202, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10063
Biochemistry and molecular biology of receptors for biogenic amines in locusts
Authors: Roeder Thomas
Published: August 2002

The biochemistry and molecular biology of biogenic amines and their metabotropic receptors in insects, with a focus on locusts, is reviewed. These compounds are known to be responsible for the control of a huge variety of different behaviours. Receptors for these amines usually belong to the class of G‐protein coupled receptors (GPCR) and transmit all known functions of these compounds. The physiological significance of biogenic amine neurotransmission in insects, especially in locusts is briefly summarised. Regarding the corresponding receptors, their pharmacological features and the molecular properties are described in detail. Microsc. Res. Tech. 56:237–247, 2002. © 2002 Wiley‐Liss, Inc.
Distribution of exogenous heavy metals in the hepatocytes of calves: A morphometric study
Authors: Horký D. , Lauschová I. , Illek J. , Pechová A. , Šindelář M.
Published: August 2002

The objective of this study was to evaluate the presence of heavy metals in the hepatocytes of the animals fed a cadmium‐supplemented diet and also receiving zinc and/or selenium in the injection form. The experiment involved four groups of calves (6–8, both sexes) receiving the heavy metals in various combinations for 95 days. Electron micrographs of liver cells were prepared and statistically evaluated using Student's t‐test. A modified morphometric apparatus was used for morphometric examination. Exogenous cadmium showed marked accumulation in the hepatocytes. If, however, the cadmium diet was combined with zinc or selenium administration the amount of the reduction product was much lower. Microsc. Res. Tech. 56:451–453, 2002. © 2002 Wiley‐Liss, Inc.
Vasotocin and mesotocin in the brains of amphibians: State of the art
Authors: Smeets Wilhelmus J.A.J. , González Agustín
Published: August 2002

Immunohistochemical studies during the last decade have revealed elaborate systems of vasotocinergic (AVT) and mesotocinergic (MST) neuronal elements in the brain of a variety of amphibians including anurans, urodeles, and gymnophionans. Apart from a well‐developed hypothalamo‐hypophysial system, the antibodies demonstrated the existence of extrahypothalamic AVT‐ and MST‐immunoreactive cell groups as well as extensive extrahypothalamic networks of immunoreactive fibers. The wide distribution of AVT‐ and MST‐immunoreactive fibers throughout the brains of amphibians suggests that the two neuropeptidergic systems are involved not only in hypothalamo‐hypophysial interactions, but also in a variety of other brain functions. Moreover, there is now evidence that sex‐related differences occur in amphibians as previously shown for amniotes. It should be noted, however, that substantial variation occurs in the relative densities of AVT‐ and MST‐immunoreactive fibers and number of cells between species, even within a single order of amphibians. Similar observations have been made in other classes of vertebrates and prompt us, therefore, to critically evaluate conclusions with respect to specific functions of AVT and MST in the central nervous system of vertebrates. Microsc. Res. Tech. 54:125–136, 2001. © 2001 Wiley‐Liss, Inc.
Evidence for target‐specific outgrowth from subpopulations of grafted human dopamine neurons
Authors: Strömberg Ingrid , Törnqvist Nina , Johansson Saga , Bygdeman Marc , Almqvist Per M.
Published: August 2002

Clinical and experimental grafting in Parkinson's disease has shown the need for enhanced survival of dopamine neurons to obtain improved functional recovery. In addition, it has been suggested that a limited number of surviving dopamine neurons project to the dopamine‐denervated host striatum. The aim of this study was to investigate if subpopulations of ventral mesencephalic dopamine neurons project to their normal targets, i.e., dorsal vs. ventral striatum. Following implantation of human ventral mesencepahlic tissue into the lateral ventricle of dopamine‐depleted rats, human‐derived dopamine reinnervation was achieved both in dorsal and ventral striatum. Treatment with the neurotoxin 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) resulted in a degeneration of tyrosine hydroxylase (TH)‐immunoreactive nerve fibers in dorsal striatum but not in ventral areas in some animals, while MPTP was without effect in other animals. TH‐immunoreactive neurons were small and appeared shrunken in animals carrying grafts affected by the MPTP treatment. In conclusion, grafted dopamine neurons projected nerve fibers into areas that they normally innervate. Thus, when searching for factors that may enhance survival of grafted dopamine neurons it is important to study which subpopulation(s) of ventral mesencephalic dopamine neurons is affected, such that a proper reinnervation may be achieved. Microsc. Res. Tech. 54:287–297, 2001. © 2001 Wiley‐Liss, Inc.
Regeneration of spines and pedicellariae in echinoderms: A review
Authors: Dubois Philippe , Ameye Laurent
Published: August 2002

Morphogenesis of tissues during regeneration of echinoderm spines and pedicellariae is reviewed. Regeneration of the skeleton is rather well documented while that of associated soft tissues is poorly investigated. In particular, little information is available on the early regeneration stages which follow wound healing. From the available information, it is suggested that regeneration of broken spines proceeds through a morphallactic process of which the organizational information, as well as the involved cells, lies in the stump. In contrast, regeneration of removed spines and pedicellariae may depend on an epimorphic process whose organizational information could be located in the mutable connective tissue that joins the appendage to the main body wall. Microsc. Res. Tech. 55:427–437, 2001. © 2001 Wiley‐Liss, Inc.
Vasculature in pre‐blastema and nerve‐dependent blastema stages of regenerating forelimbs of the adult newt, Notophthalmus viridescens
Authors: Rageh Mona A.E. , Mendenhall Luciara , Moussad Essam E.A. , Abbey Sarah E. , Mescher Anthony L. , Tassava Roy A.
Published: August 2002

Immunocytochemistry utilizing a monoclonal antibody (BV1; blood vessel 1) highly reactive to the vasculature of the adult newt showed that a developing vasculature was present during early, pre‐blastema, and early‐bud blastema stages of forelimb regeneration in this species. Infusion of Prussian Blue and DiI into the brachial artery further delineated the intactness of this early vasculature. Finally, macroscopic observations of vascular flow underneath the apical epithelial cap (AEC) and microsurgical removal of the AEC and observation of subsequent bleeding buttressed the conclusion that an intact vasculature exists during early nerve‐dependent stages of newt forelimb regeneration. The results suggest that this process of neovascular formation is angiogenesis, i.e., the formation of new vessels from pre‐existing vessels in the stump. Furthermore, angiogenesis is an ongoing process initiated early after amputation. Blastema cells and the AEC are likely sources of factors that stimulate neovascularization. J. Exp. Zool. 292:255–266, 2002. © 2002 Wiley‐Liss, Inc.
Turán problems for integer‐weighted graphs
Authors: Füredi Zoltán , Kündgen André
Published: August 2002

A multigraph is (k,r)‐dense if every k‐set spans at most r edges. What is the maximum number of edges exℕ(n,k,r) in a (k,r)‐dense multigraph on n vertices? We determine the maximum possible weight of such graphs for almost all k and r (e.g., for all r>k3) by determining a constant m=m(k,r) and showing that exℕ(n,k,r)=m$\left ( n\atop 2\right )$+O(n), thus giving a generalization of Turán's theorem. We find exact answers in many cases, even when negative integer weights are also allowed. In fact, our main result is to determine the maximum weight of (k,r)‐dense n‐vertex multigraphs with arbitrary integer weights with an O(n) error term. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 195–225, 2002
Extremal problems for chromatic neighborhood sets
Authors: Kündgen André , Molloy Michael
Published: August 2002

The chromatic neighborhood sequence of a graph G is the list of the chromatic numbers of the subgraphs induced by the neighborhoods of the vertices. We study the maximum multiplicity of this sequence, proving, amongst other things, that if a chromatic neighborhood sequence has t distinct values, the largest value being dt, then there is a value with multiplicity at least ${2d_t \over t}(1-\Theta(\ln\ t/t))$. This bound is asymptotically tight. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 68–74, 2002
Orthogonal factorizations of graphs
Authors: Feng Haodi , Liu Guizhen
Published: August 2002

Let G be a graph with vertex set V(G) and edge set E(G). Let k1, k2,…,km be positive integers. It is proved in this study that every [0,k1+…+km−m+1]‐graph G has a [0, ki]1m‐factorization orthogonal to any given subgraph H with m edges. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 267–276, 2002
On factors of 4‐connected claw‐free graphs*
Authors: Broersma H. J. , Kriesell M. , Ryjác̆ek Z.
Published: August 2002

We consider the existence of several different kinds of factors in 4‐connected claw‐free graphs. This is motivated by the following two conjectures which are in fact equivalent by a recent result of the third author. Conjecture 1 (Thomassen): Every 4‐connected line graph is hamiltonian, i.e., has a connected 2‐factor. Conjecture 2 (Matthews and Sumner): Every 4‐connected claw‐free graph is hamiltonian. We first show that Conjecture 2 is true within the class of hourglass‐free graphs, i.e., graphs that do not contain an induced subgraph isomorphic to two triangles meeting in exactly one vertex. Next we show that a weaker form of Conjecture 2 is true, in which the conclusion is replaced by the conclusion that there exists a connected spanning subgraph in which each vertex has degree two or four. Finally we show that Conjectures 1 and 2 are equivalent to seemingly weaker conjectures in which the conclusion is replaced by the conclusion that there exists a spanning subgraph consisting of a bounded number of paths © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 125–136, 2001
Large induced forests in sparse graphs
Authors: Alon Noga , Mubayi Dhruv , Thomas Robin
Published: August 2002

For a graph G, let a(G) denote the maximum size of a subset of vertices that induces a forest. Suppose that G is connected with n vertices, e edges, and maximum degree Δ. Our results include: (a) if Δ ≤ 3, and G ≠ K4, then a(G) ≥ n − e/4 − 1/4 and this is sharp for all permissible e ≡ 3 (mod 4); and (b) if Δ ≥ 3, then a(G) ≥ α(G) + (n − α(G))/(Δ − 1)2. Several problems remain open. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 113–123, 2001
Synthesis of [1,2‐14C]trichloroacetic acid
Authors: Bubner M. , Fuksová K. , Matucha M. , Heise K. H. , Bernhard G.
Published: August 2002

A growing interest in the phytotoxic effects of trichloroacetic acid (TCA) has led us to develop a small‐scale (<1 mmol) one‐pot synthesis of [1,2‐14C]TCA with >70% yield and specific activity of 3.7 GBq/mmol. Copyright © 2001 John Wiley & Sons, Ltd.
The hidden code in genomics: a tool for gene discovery
Authors: Kohler Heinz , Murali Ramachandran , Kieber‐Emmons Thomas
Published: August 2002

Among new insights coming from the completion of sequencing of the human genome, reported in Nature and Science, are clues of how evolution has increased the complexity of species, and in particular how the genetic code has enabled this process. It is clear that life has not only evolved by increasing the number of genes, but also by ingeniously evolving an efficient code for expressing diversity in the building blocks (i.e. the amino acids). The rules of nucleic acid base pairing and the classification of amino acids according to hydrophobicity/hydrophilicity relationships define a binary DNA code, which determines the general biophysical characteristics of proteins. Sense and antisense strands can encode protein segments having inverted and complementary hydropathy. The underlying binary code controls association and dissociation of proteins and presumably represents a primordial code that might have emerged in the early stages of self‐organizing biochemical cycles. It is the purpose of this communication to provide a perspective of the code in the context of a binary language from its primordial origin to its present day format and to propose to use this code as a genomic mining tool. Copyright © 2001 John Wiley & Sons, Ltd.
Texture analysis of human liver
Authors: Jirák Daniel , Dezortová Monika , Taimr Pavel , Hájek Milan
Published: August 2002

Purpose

To classify healthy and diseased livers by texture analysis (TA).

Materials and Methods

We studied 43 patients divided into four groups according to their clinical stage and 10 controls on a 1.5‐T magnetic resonance (MR) imager, using a T2‐weighted breath‐hold sequence. For the TA, features of the first and second order were used, and several classification procedures were applied for the classification of patients and controls. The choice of features was performed manually and by use of the Fischer coefficient, average correlation coefficients between features and multidimensional discrimination measure.

Results

All the statistical methods employed were able to differentiate between controls and patients in each group. The classification error varied around 8%.

Conclusion

We have shown that texture analysis can be successfully used for separating cirrhotic patients and healthy volunteers. Different sets of TA features can be used for a similar classification of patients. J. Magn. Reson. Imaging 2002;15:68–74. © 2002 Wiley‐Liss, Inc.
fMRI of the auditory cortex in patients with unilateral carotid artery steno‐occlusive disease
Authors: Bilecen Deniz , Radü Ernst Wilhelm , Schulte Anja‐Carina , Hennig Jürgen , Scheffler Klaus , Seifritz Erich
Published: August 2002

Purpose

To examine whether an internal carotid artery (ICA) steno‐occlusive disease leads to a reduced blood oxygenation level dependent (BOLD)‐signal change due to a decreased vasodilatory reserve capacity.

Materials and Methods

Patients suffering from unilateral ICA stenosis or occlusion were examined using functional magnetic resonance imaging (fMRI) of the auditory cortex with a bilateral stimulation applying a pulsed 1000 Hz sine‐tone.

Results

Compared to control subjects, who showed symmetric bilateral BOLD‐responses within the auditory cortex, the ICA patients revealed either a normal bilateral cortical activation pattern or a reduced cortical activation on the steno‐occluded side. This latter decrease of BOLD‐signal change might indicate a depressed vasomotor reserve capacity. The observed coincidence between this asymmetric reduction in BOLD‐signal and ischemic borderzone lesions on the affected side in this subgroup of patients strongly supports this assumption.

Conclusion

This study shows that fMRI of the auditory cortex appears to have clinical merit in the workup of cerebrovascular conditions. J. Magn. Reson. Imaging 2002;15:621–627. © 2002 Wiley‐Liss, Inc.
Mass spectrometry of steroid glucuronide conjugates. II—Electron impact fragmentation of 3‐keto‐4‐en‐ and 3‐keto‐5α‐steroid‐17‐O‐β glucuronides and 5α‐steroid‐3α,17β‐diol 3‐ and 17‐glucuronides
Authors: Thevis Mario , Opfermann Georg , Schmickler Hans , Schänzer Wilhelm
Published: August 2002

The steroid glucuronide conjugates of 16,16,17‐d3‐testosterone, epitestosterone, nandrolone (19‐nortestosterone), 16,16,17‐d3‐nortestosterone, methyltestosterone, metenolone, mesterolone, 5α‐androstane‐3α,17β‐diol, 2,2,3,4,4‐d5‐5α‐androstane‐3α,17β‐diol, 19‐nor‐5α‐androstane‐3α,17β‐diol, 2,2,4,4‐d4‐19‐nor‐5α‐androstane‐3α,17β‐diol and 1α‐methyl‐5α‐androstane‐3α/β,17β‐diol were synthesized by means of the Koenigs–Knorr reaction. Selective 3‐ or 17‐O‐conjugation of bis‐hydroxylated steroids was performed either by glucuronidation of the corresponding steroid ketole and subsequent reduction of the keto group or via a four‐step synthesis starting from a mono‐hydroxylated steroid including (a) protection of the hydroxy group, (b) reduction of the keto group, (c) conjugation reaction and (d) removal of protecting groups. The mass spectra and fragmentation patterns of all glucuronide conjugates were compared with those of the commercially available testosterone glucuronide and their characterization was performed by gas chromatography/mass spectrometry and nuclear magnetic resonance spectroscopy. For mass spectrometry the substances were derivatized to methyl esters followed by trimethylsilylation of hydroxy groups and to pertrimethylsilylated products using labelled and unlabelled trimethylsilylating agents. The resulting electron ionization mass spectra obtained by GC/MS quadrupole and ion trap instruments, full scan and selected reaction monitoring experiments are discussed, common and individual fragment ions are described and their origins are proposed. Copyright © 2001 John Wiley & Sons, Ltd.
Longitudinal sero‐reactivity to human herpesvirus 8 (KSHV) in the Swiss HIV Cohort 4.7 years before KS
Authors: Quinlivan E. Byrd , Wang Rui Xue , Stewart Paul W. , Kolmoltri Chulaluk , Regamey Nicolas , Erb Peter , Vernazza Pietro L. ,   the Swiss HIV Cohort Study
Published: August 2002

The relationship between viral infection with Kaposi sarcoma‐associated herpesvirus (KSHV) and the onset of Kaposi sarcoma (KS) in AIDS patients is incompletely understood. This study investigates the use of three serological assays to predict the development of KS in HIV‐positive patients. Serially collected serum samples from 36 patients with KS and matched controls in the Swiss HIV Cohort Study (SHCS) were analyzed in a case control study. Three serologic assays to detect antibodies against KSHV (nuclear and membrane antigen immunofluorescence assay, N‐IFA, M‐IFA and ORF 65.2 ELISA) were used to determine the predictive value of KSHV‐seropositivity. Serial samples from the cases were also analyzed to determine longitudinal patterns of seroreactivity and identify cases of seroconversion. Assay sensitivity for detection of KSHV antibodies was highest for M‐IFA (83%), followed by N‐IFA (74%) and 65.2 ELISA (52%). At the time of initial serum sampling (median 4.7 years before KS), only the N‐IFA distinguished case and control sera (61% vs. 32%) and no assay was clearly predictive of subsequent onset of clinical KS. Moreover, an unexpectedly high rate of reversions to seronegativity were observed by N‐IFA (27/33) as well as by 65.2 ELISA (11/26) in the longitudinal analysis. Analysis of the ORF65.2 ELISA index indicated that these reversions before the clinical onset of KS were associated with antibody levels that frequently hovered around the level of detectability. A marked increase in ORF 65.2 antibody titer occurred in a third of the patients at the time of KS diagnosis. Only two seroconversions were documented. KSHV infection within the SHCS is likely to have preceded HIV infection. KSHV infection alone is not highly predictive of KS development in this cohort of HIV‐infected homosexual men as compared with matched controls. Three KSHV serologic assays, though sensitive at the time of clinical KS are inconsistently positive before the development of AIDS‐related KS. J. Med. Virol. 64:157–166, 2001. © 2001 Wiley‐Liss, Inc.
Strategies for reliable diagnosis of hepatitis C infection: The need for a serological confirmatory assay
Authors: Schröter Matthias , Schäfer Peter , Zöllner Bernhard , Polywka Susanne , Laufs Rainer , Feucht Heinz‐Hubert
Published: August 2002

The aim of the study was to examine whether the diagnosis of Hepatitis C (HCV) infection can be obtained reliably without using an immunoblot‐based confirmation assay. 1,708 EIA‐reactive serum samples were examined retrospectively for (i) optical density value in the screening assay, (ii) reactivity in an immunoblot assay, and (iii) result by RT PCR. In 1,394 (81.0%) samples positive results were obtained by both the HCV EIA and the confirmation assay. OD‐values ≥2.2 were observed in 1026 of these samples, but covered the range from 0.4 to 2.1 in the other 368 samples. The combination of HCV EIA reactivity and indeterminate immunoblot assay was observed in 134 (7.8%) serum samples. HCV RNA was detected in 58 cases by PCR. The OD‐values of these 58 samples ranged from 0.4 to >2.2. Especially reactivity against the core recombinant protein was indicative of PCR positivity. The reactivity by the HCV EIA could not be confirmed by immunoblot assay or PCR in 180 (10.5%) sera. These false reactive sera showed OD values by EIA from 0.3 to 2.1. It is concluded that no threshold values can be defined which would allow differentiation between positive, indeterminate, and false reactive result by HCV EIA without producing an inacceptably high number of false negative diagnoses. Not using immunoblot‐based confirmation would result in many additional PCR examinations. Therefore, confirmation of reactive HCV EIA results by a serological confirmatory assay must remain an essential part of the diagnostic procedure. J. Med. Virol. 64:320–324, 2001. © 2001 Wiley‐Liss, Inc.