bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of extraction and enzymatic esterification of ethanol on glucose consumption by two Saccharomyces cerevisiae strains: a comparative study
Authors: Oliveira A Cristina , Rosa M Fernanda , Cabral Joaquim M S , Aires‐Barros M Raquel
Published: August 2002

Extractive alcoholic fermentations of high glucose concentrations (300 and 400 g dm−3) using a flocculent (saké) and a non‐flocculent (DER24) Saccharomyces cerevisiae strain were compared. The introduction of a Rhizomucor miehei lipase, in the extractive fermentations of 300 g dm−3 of glucose, increased the ethanol extraction due to its esterification with oleic acid, allowing complete glucose consumption at an organic solvent/fermentation medium phase ratio of 1. In these conditions, an increase of ethanol yield was observed. Total glucose consumption was also obtained in enzymatic extractive fermentations of 400 g dm−3 of glucose, but only when oleic acid was added at the exponential growth phase. From the comparison of the extractive fermentation performances obtained using the two yeast strains it was observed that the flocculent strain led to a lower glucose metabolisation rate. This behaviour was related to the highest diffusional limitations that occur in the presence of flocs. The developed processes showed that the association of alcoholic fermentation with enzymatic extraction led to the reduction of inhibitory effects as well as to the simultaneous production of fatty esters which are compounds with several commercial applications.

© 2001 Society of Chemical Industry
Dimethylsulfoxide elevates extracellular laccase (phenol oxidase) activity ofPycnoporus cinnabarinusgrown on a low nutritional newspaper medium
Authors: Jones Cameron L , Baker Warren L , Lonergan Greg T
Published: August 2002

The white‐rot fungusPycnoporus cinnabarinus, grown on a low nutrient newspaper medium, secreted low amounts of extracellular laccase. The laccase activity was increased when 3% methanol was added to the medium and further increased when 3% dimethylsulfoxide was added. Dimethylsulfoxide increased the enzyme activity over controls when the fungus was grown on a malt extract broth, or media containing either recycled Kraft paper or cellobiose. Treatment with the ionophore A23187 suggested that dimethylsulfoxide acted as a paramorphogen to increase the branch points of the mycelial mat. Hence, the number of ion channels for secretion of the enzyme was increased. When the fungus was grown in a 2 dm3bioreactor, sparged with air, the measured extracellular protein concentration rose and remained relatively steady for 15 days. The enzyme activity and specific activity reached a maximum between days 6 and 9 and then fell from day 10 of fermentation. The presence of dimethylsulfoxide in the bioreactor caused a four‐fold increase in enzyme activity and prolonged its secretion in the bioreactor for at least 25 days. The protein concentration and specific activity also remained at high levels over this period.

© 2001 Society of Chemical Industry
Enzymatic alcoholysis of triolein to produce wax ester
Authors: Hadzir Nursyamsyila Mat , Basri Mahiran , Rahman Mohd Basyaruddin Abd , Razak Che Nyonya Abdul , Rahman Raja Noor Zaliha Abd , Salleh Abu Bakar
Published: August 2002

An alcoholysis reaction between triolein and oleyl alcohol catalyzed by Lipozyme and Novozyme was carried out to produce oleyl oleate, a wax ester. The effects of various reaction parameters such as time, reaction temperature, amount of enzyme, molar ratio of substrates (oleyl alcohol/triolein), various organic solvents used and the initial water activity, aw of the reaction system were studied. The best conditions tested to produce wax ester were respectively, incubation time, 5 h; temperature, 50 °C for Lipozyme and 60 °C for Novozyme; weight of enzyme, 0.30 g and molar ratio of oleyl alcohol to triolein, 6:1. The use of organic solvents greatly influenced the activity of lipase. Generally, the activity of lipase was high in nonpolar solvents with log P values greater than 2.50. Heptane and hexane were the best solvents tested. The enzymatic synthesis of oleyl oleate was best carried out at aw 0.32. Analysis of the yield of the products of the reaction at optimized reaction condition using Lipozyme showed that 75.66% oleyl oleate was produced.

© 2001 Society of Chemical Industry
Two small intrahepatic cholangiocarcinomas with different sonographic appearances
Authors: Yamamoto Takatsugu , Takeuchi Kazuo , Okuda Chikao , Honjo Hajime , Sakurai Norio , Watanabe Goro , Mori Masaya , Kuyama Yasushi
Published: August 2002

We report on 2 cases of small intrahepatic (or peripheral) cholangiocarcinomas initially detected by sonography and completely resected. The lesions had a peripheral hypoechoic component and a central isoechoic or hyperechoic component. One had posterior acoustic shadowing on sonography, and the other did not. Comparison with pathologic findings in both cases indicated that severe fibrotic changes may have caused the posterior acoustic shadowing. This finding is extremely rare. We found only 1 previously reported case of cholangiocarcinoma accompanied by acoustic shadowing. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:344–348, 2001.
Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): A review
Authors: Hisano Setsuji , Nogami Haruo
Published: August 2002

Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action. Some of them have been identified in the hypothalamus, which is the only brain site where a neural signal is converted to a humoral one, namely, a hormone for a target organ. This unique neural mechanism has long attracted attention as the neuroendocrine system, part of which has been extensively studied as the hypothalamic‐neurohypophysial system involved in secretion of vasopressin and oxytocin. However, transporters in this system have been less well studied. A morphological examination of novel transporters would give us cues to a better understanding of the neuronal organization and function of the system. In this review, we first summarize recent findings on expression of transporter gene and immunoreactivity in the hypothalamus. In the second part, we explain our observations on two vesicular glutamate (inorganic phosphate) transporters (BNPI and DNPI) in the supraoptic and paraventricular nuclei and neurohypophysis. Further study of these and other transporters will provide a basis on which to reevaluate the organization and function of the hypothalamic‐neurohypophysial system. Microsc. Res. Tech. 56:122–131, 2002. © 2002 Wiley‐Liss, Inc.
Elemental maps from EFTEM images using two different background subtraction models
Authors: Quintana C. , Lechaire J.P. , Bonnet N. , Risco C. , Carrascosa J.L.
Published: August 2002

Acquisition of a great number of energy‐filtered images in a TEM (EFTEM) around the characteristic signal with a low energy‐selecting slit allows display of the electron energy loss (EEL)‐spectrum of regions of interest (ROIs) of a sample. These EEL‐spectra can be submitted to the different treatments already in use for electron energy loss spectroscopy (EELS). In particular, it is possible to fit the experimental background with different mathematical models, using images acquired below and above a characteristic ionization edge. After this fitting, elemental maps can be computed by subtraction of the extrapolated/interpolated background from the characteristic images. In this work, we compared two mathematical models for background fitting—the Egerton power law and the log‐polynomial law. We studied the low‐energy region (40–150 eV) and a higher‐energy region (350–600 eV) with the aid of software for interactive processing of EFTEM image series that we developed. The analyzed elements were the constitutive elements: iron, phosphorus, nitrogen, and oxygen in several biological materials. Two analytical TEMs, one equipped with a post‐column and the other with an in‐column spectrometer, were used. Our experimental results confirm that the power law is very sensitive to the value of the energy loss of the pre‐edge images when the background is computed by extrapolation. The log‐polynomial model is less sensitive than the power law model to the value of the energy loss of the pre‐edge images in the low energy region. For the oxygen K edge at 535 eV, it gives the best fit when it is combined with the interpolation method. The use of programs that facilitate the handling of EFTEM image series, and the controlled calculation of the background under the characteristic images, represent a step forward in the generation of elemental maps. Microsc. Res. Tech. 53:147–156, 2001. © 2001 Wiley‐Liss, Inc.
Gastric leptin
Authors: Lewin Miguel J.M. , Bado André
Published: August 2002

The recent discovery of gastric leptin has initiated several investigations on the possible role of leptin in digestive physiology. The following clues are currently suggested: leptin might control meal size in cooperation with Cholecystokinin, help cytoprotection of the gastric mucosa, play a role in gut inflammatory processes, regulate secretion of gastric hormones such as gastrin and somatostatin, and modulate intestinal transport of small peptides. The present review is a brief survey of the most significant advances in these issues. Microsc. Res. Tech. 53:372–376, 2001. © 2001 Wiley‐Liss, Inc.
Comparative analysis of adrenomedullin‐like immunoreactivity in the hypothalamus of amphibians
Authors: Muñoz Margarita , López Jesús M. , Sánchez‐Camacho Cristina , Moreno Nerea , Crespo Miguel , González Agustín
Published: August 2002

Adrenomedullin (AM) is a novel neuropeptide with special significance in the mammalian hypothalamo‐hypophysial axis. By using an antiserum specific for human AM, we have studied the localization of AM‐like immunoreactive (AMi) cell bodies and fibers in the hypothalamus and hypophysis of the amphibians Rana perezi (anuran), Pleurodeles waltl (urodele), and Dermophis mexicanus (gymnophionan). Distinct AMi cell groups were found for each species. In the anuran, six cell groups were localized in the preoptic and infundibular regions, whereas only three and one were found in the urodele and gymnophionan, respectively. A comparative analysis of AMi cells and cells expressing arginine vasotocin (AVT), neuropeptide Y (NPY), and tyrosine hydroxylase (TH) revealed strong differences between species. Thus, colocalization of AVT/AM is most likely to occur in the preoptic magnocellular nucleus of urodeles and it is reflected by the intense AM immunoreactivity in the neural lobe of the hypophysis. Colocalization of NPY/AM seems to be possible in the suprachiasmatic nucleus of anurans. In the gymnophionan, cells containing AVT and NPY are distinct from AMi cells. Only in anurans, the ventral aspect of the suprachiasmatic nucleus possesses a small population of AMi cells that express also TH immunoreactivity and most likely also express NPY. The results strongly suggest that AM in amphibians plays an important regulatory role in the hypothalamo‐hypophysial system, as has been demonstrated in mammals. On the other hand, substantial differences have been found between species with respect to the degree of colocalization with other chemical substances. Microsc. Res. Tech. 54:173–187, 2001. © 2001 Wiley‐Liss, Inc.
On the critical point‐arboricity graphs
Authors: Škrekovski Riste
Published: August 2002

In this paper, we study the critical point‐arboricity graphs. We prove two lower bounds for the number of edges of k‐critical point‐arboricity graphs. A theorem of Kronk is extended by proving that the point‐arboricity of a graph G embedded on a surface S with Euler genus g = 2, 5, 6 or g ≥ 10 is at most $k =\lfloor {9 +\sqrt {1+ 24\, g}\over 4}\rfloor$ with equality holding iff G contains either K2k−1 or K2k−4 + C5 as a subgraph. It is also proved that locally planar graphs have point‐arboricity  ≤ 3 and that triangle‐free locally planar‐graphs have point‐arboricity ≤ 2. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 50–61, 2002
A rigid graph for every set
Authors: Nešetřil Jaroslav
Published: August 2002

A graph G is called rigid if the identical mapping V(G)→V(G) is the only homomorphism G→G. In this note we give a simple construction of a rigid oriented graph on every set. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 108–110, 2002
Stability of arc‐transitive graphs
Authors: Surowski David B.
Published: August 2002

The present paper investigates arc‐transtive graphs in terms of their stability, and shows, somewhat contrary to expectations, that the property of instability is not as rare as previously thought. Until quite recently, the only known example of a finite, arc‐transitive vertex‐determining unstable graph was the underlying graph of the dodecahedron. This paper illustrates some methods for constructing finite arc‐transitive unstable graphs, and three infinite families of such graphs are given as applications. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 95–110, 2001
Perceptions of drudgery in agricultural and animal husbandry operations: a gender analysis from Haryana State, India
Authors: Thakur Sonika , Varma Shashi Kanta , Goldey Patricia A.
Published: August 2002

The paper examines the involvement and drudgery profile of rural women and men in agricultural and animal husbandry activities in India. The activities assigned to men were those which were considered to demand greater physical power, skill and performance. The activities assigned to women were considered to demand less physical power, lower skill and more time. They were also monotonous in their nature and low paid. The implications of the study indicate a need to match technological and innovative solutions to the drudgery that women experience in agricultural and animal husbandry operations: also, the fact that women shoulder a greater share of those tasks perceived to involve drudgery is in itself worthy of particular attention. In addition to shouldering almost the entire work load of household activities and substantial responsibilities in child rearing, women were found to work in agricultural and animal husbandry activities for more hours than men. Copyright © 2001 John Wiley & Sons, Ltd.
Operating principle of an electron monochromator in an axial magnetic field
Authors: Grill Verena , Drexel Herwig , Sailer Wolfgang , Lezius Matthias , Märk Tilmann D.
Published: August 2002

Electron monochromators which are operated within an axial magnetic (guiding) field are especially suitable for the production of monochromatic electrons at low energies. Although in principle the technology of such devices has an appreciable historic background, we have discovered experimentally important new features, which cannot be understood using the previously published theories of operation. An in‐depth study of the electron trajectories in a crossed electric and magnetic field using Simion1 showed a number of possible pitfalls, which have to be avoided in construction and operation. From our simulations we derived a novel design and operational method, which is currently under evaluation. We have already demonstrated that using this novel design an electron energy resolution of about 50 meV is realistic. Copyright © 2001 John Wiley & Sons, Ltd.
Characterization of novel di‐ and tricarboxylic acids in fine tropical aerosols
Authors: Zdráhal Zbyněk , Vermeylen Reinhilde , Claeys Magda , Maenhaut Willy , Guyon Pascal , Artaxo Paulo
Published: August 2002

Three unknown di‐ and tricarboxylic acids were characterized in the fine size fraction of aerosols which were collected during the wet season in the Amazon basin (Rondonia, Brazil). For the structural characterization of the methyl esters of these unknown compounds, mass spectrometry with electron ionization (EI) and tandem mass spectral techniques combined with gas chromatographic (GC) separation were employed. Fragment and parent ion spectra were recorded during elution of the GC peaks by linked scanning of the B and E sectors in combination with high‐energy collision‐induced dissociation. The fragmentation patterns of significant ions in the first‐order EI spectra were also obtained for nonanedioic acid, which was examined as a model compound. The compounds were tentatively identified as 4‐acetyloxyheptanedioic acid and cis and trans isomers of 5‐hexene‐1,1,6‐tricarboxylic acid. Since there were indications of biomass burning during the aerosol sampling the di‐ and tricarboxylic acids characterized in the present work could be markers for biomass burning. Furthermore, the characterization of di‐ and tricarboxylic acids in the fine size fraction of atmospheric aerosols may be important for assessing the effects of organic aerosols in cloud formation. Copyright © 2001 John Wiley & Sons, Ltd.
Field desorption mass spectrometry of large multiply branched saturated Hydrocarbons
Authors: Gross Jürgen H. , Vékey Károly , Dallos András
Published: August 2002

Large multiply branched saturated hydrocarbons containing 67–103 carbon atoms (molecular masses 941.8–1446.8 Da) were analyzed by field desorption mass spectrometry (FD‐MS) with a double‐focusing mass spectrometer. FD‐MS was found to have detection limits in the 100 fmol range. The FD mass spectra exhibited molecular ions of astonishingly low abundance. However, the fragment ions formed were closely related to the proposed molecular structure, allowing us to set up rules for straightforward structure elucidation of unknowns. In detail, (i) dehydrogenation, (ii) alkyl losses from molecular ions and (iii) subsequent alkene losses were observed. The influence of the electric field strength on dehydrogenation and C—C cleavages was examined by variation of the emitter potential. Additionally, ion dissociations in the ion source and in the first and second field‐free regions, respectively, were compared to study the relative importance of field‐induced and thermally induced processes. Copyright © 2001 John Wiley & Sons, Ltd.
Mass spectrometry and combinatorial chemistry: a short outline
Authors: Triolo Antonio , Altamura Maria , Cardinali Franco , Sisto Alessandro , Maggi Carlo Alberto
Published: August 2002

The rapid evolution of combinatorial chemistry in recent years has led to a dramatic improvement in synthetic capabilities. The goal is to accelerate the discovery of molecules showing affinity against a target, such as an enzyme or a receptor, through the simultaneous synthesis of a great number of structurally diverse compounds. This is done by generating combinatorial libraries containing as many as hundreds or thousands of compounds. The need to test all these compounds led to the development of high‐throughput screening (HTS) techniques, and also high‐throughput analytical techniques capable of assessing the occurrence, structure and purity of the products. In order to be applied effectively to the characterization of combinatorial libraries, an analytical technique must be adequately sensitive (to analyse samples which are typically produced in nanomole amounts or less), fast, affordable and easy to automate (to minimize analysis time and operator intervention). Although no method alone can meet all the analytical challenges underlying this task, the recent progress in mass spectrometric (MS) instrumentation renders this technique an essential tool for scientists working in this area.

We describe here relevant aspects of the use of MS in combinatorial technologies, such as current methods of characterization, purification and screening of libraries. Some examples from our laboratory deal with the analysis of pooled oligomeric libraries containing n × 324(n = 1, 2) compounds, using both on‐line high‐performance liquid chromatography/MS with an ion trap mass spectrometer, and direct infusion into a triple quadrupole instrument. In the first approach, MS and product ion MS/MS with automatic selection of the precursor were performed in one run, allowing library confirmation and structural elucidation of unexpected by‐products. The second approach used MS scans to characterize the entire library and also precursor ion and neutral loss scans to detect selectively components with given structural characteristics. Copyright © 2001 John Wiley & Sons, Ltd.
Investigation of homo‐ and heterodimer alkali metal cation complexes of resorc[4]arenes by electrospray ionization mass spectrometry
Authors: Letzel Matthias C. , Agena Ceno , Mattay Jochen
Published: August 2002

Resorc[4]arenes are compounds with interesting properties, mainly because of their ability to form host–guest complexes with the guest located inside the cavity. The size of the guest limits the complexation, as shown by a competition experiment with tetraalkylammonium ions of different size. By electroscopy ionization tandem mass spectrometric experiments on resorc[4]arene heterodimers bearing an alkali metal ion as guest, it was found that there must be two different binding mechanisms for alkali metal ions with high surface charge density (Li+ and Na+) on the one hand compared with those with a lower surface charge density on the other hand (K+, Rb+, Cs+). Copyright © 2001 John Wiley & Sons, Ltd.
Occurrence and severity of infections caused by subgroup A and B respiratory syncytial virus in children in Southeast Brazil
Authors: Cintra O.A.L. , Owa M.A. , Machado A.A. , Cervi M.C. , Figueiredo L.T.M. , Rocha G.M. , Siqueira M.M. , Arruda E.
Published: August 2002

The frequency and severity of infections caused by respiratory syncytial virus (RSV) were assessed in children <2 years of age seen at the emergency department. The frequency of RSV detection in the clinical virology laboratory during the past 3 years was also analyzed retrospectively. RSV was found in 21.6% (188/869) of the samples collected from children seen at the emergency department and was found to be more frequent during the autumn, being less frequent or negligible by midwinter. RSV subgroups A and B co‐circulated within the same time period in children seen at the emergency department, with varying predominance of either subgroup. There was no significant association of RSV subgroup with disease severity, but only a trend for RSV subgroup B being more frequent in children with risk factors for severe disease. J. Med. Virol. 65:408–412, 2001. © 2001 Wiley‐Liss, Inc.
Video‐microscopic analysis of dye coupling in the salamander olfactory bulb
Authors: Du J. , Maloney R.E. , Hamilton K.A.
Published: August 2002

Cells in the mitral cell (MCL) and granule cell (GCL) layers of the olfactory bulb shape the representation of odor information in the brain. After intracellular Lucifer Yellow (LY) injections into lightly fixed olfactory bulb slices, clusters of dye coupled cells were previously observed in the MCL and GCL, but the relative extent of coupling in the two layers was unknown in adults. In the present study, the time course of LY coupling in the adult salamander olfactory bulb was quantified using video‐microscopic methods. Analysis of fluorescent cell body counts showed that the incidence and the extent of LY coupling are greater in the GCL than in the MCL. With optimal low‐current injection procedures, 97% of the injections into the GCL exhibited at least one coupled cell, and on average groups of six to eight cells were counted. Fewer injections into the MCL exhibited only one to three coupled cells. Some of these coupled cells were clearly mitral cells. No staining of cells was observed after extracellular LY injections, and intracellular injections of dextran dyes stained single cells, providing evidence that the LY coupled cells were stained through an intercellular route, presumably gap junctions. In live intact preparations, rapid LY staining of cell clusters was also observed using patch pipettes. Together, these results provide evidence that robust coupling occurs among olfactory bulb neurons in adults, which could have functional significance. © 2002 Wiley‐Liss, Inc.
GABA‐B‐related activity in processing of transcallosal response in cat motor cortex
Authors: Chowdhury Syed A. , Matsunami Ken Ichi
Published: August 2002

GABA‐ergic characteristics of transcallosal (TC) responses were studied with specific antagonists of both GABA‐A and GABA‐B receptor subtypes. We used a paired‐pulse paradigm to get insight into the role of GABA in interhemispheric interactions between motor cortices. 3‐Amino‐2‐(4‐chlorophenyl)‐propylphosphonic acid (phaclofen) and 3‐aminopropyl‐diethoxymethyl‐phosphinic acid (CGP 35348) were used as GABA‐B antagonists and bicuculline methiodide (BMI) was used to block the GABA‐A receptor. Although both GABA‐A and GABA‐B antagonists increased spike discharge upon transcallosal stimulation, in both pyramidal tract and non‐pyramidal tract neurons, they had different effects on the responses to the first and second stimuli of paired‐pulse stimulation (200 msec interval). Although the inhibition seen with the second stimulus was greatly attenuated by antagonists of the GABA‐B receptor, it was maintained in the presence of the GABA‐A antagonist. These finding support a presynaptic regulation of callosal transmission by GABA‐B receptors in the callosal synapse of the cat motor cortex. © 2002 Wiley‐Liss, Inc.
Extended action of MKC‐242, a selective 5‐HT1A receptor agonist, on light‐induced Per gene expression in the suprachiasmatic nucleus in mice
Authors: Takahashi Satomi , Yoshinobu Yuko , Aida Reiko , Shimomura Haruka , Akiyama Masashi , Moriya Takahiro , Shibata Shigenobu
Published: August 2002

We reported previously that (S)‐5‐[3‐[(1,4‐benzodioxan‐2‐ylmethyl)amino]propoxy]‐1,3‐benzodioxole hydrochloride (MKC‐242) (3 mg kg−1, i.p.), a selective 5‐HT1A receptor agonist, accelerated the re‐entrainment of hamster wheel‐running rhythms to a new 8 hr delayed or advanced light‐dark cycle, and also potentiated the phase advance of the wheel‐running rhythm produced by light pulses. The molecular mechanism underlying MKC‐242‐induced potentiation of this phase shift, however, has not yet been elucidated. We examined the effects of MKC‐242 on light‐induced mPer1 and mPer2 mRNA expression in the suprachiasmatic nucleus (SCN) of mice. MKC‐242 (5 mg kg−1, i.p.) potentiated light‐induced mPer1 and mPer2 expression in the SCN of mice housed in constant darkness for 2 days, when mRNA levels were observed 3 hr after light‐exposure. More potentiating action of MKC‐242 on mPer2 expression in the SCN was observed in mice housed in constant darkness for 9–10 days. This facilitatory action of MKC‐242 on mPer1 expression was antagonized by WAY100635, a selective 5‐HT1A receptor blocker, indicating that MKC‐242 activated 5‐HT1A receptors. Other drugs such as 8‐hydroxy‐dipropylaminotetralin (10 mg kg−1, i.p.), paroxetine (10 mg kg−1, i.p.), buspirone (10 mg kg−1, i.p.), and diazepam (10 mg kg−1, i.p.) did not display a potentiating action on light‐induced mPer1 and mPer2 expression in the SCN. In the behavioral experiments, we found that MKC‐242 (5 mg kg−1, i.p.) potentiated light‐induced phase delays of free‐running rhythm in mice. The present results suggest that prolonged increase of mPer1 or mPer2 expression in the SCN by MKC‐242 may be involved in the potentiation of photic entrainment by MKC‐242 in mice. © 2002 Wiley‐Liss, Inc.
Involvement of the 5‐lipoxygenase pathway in the neurotoxicity of the prion peptide PrP106‐126
Authors: Stewart Leanne R. , White Anthony R. , Jobling Michael F. , Needham B. Elise , Maher Fran , Thyer James , Beyreuther Konrad , Masters Colin L. , Collins Steven J. , Cappai Roberto
Published: August 2002

Transmissible spongiform encephalopathies are characterised by the transformation of the normal cellular prion protein (PrPC) into an abnormal isoform (PrPTSE). Previous studies have shown that N‐methyl‐D‐aspartate (NMDA) receptor antagonists can inhibit glutathione depletion and neurotoxicity induced by PrPTSE and a toxic prion protein peptide, PrP106‐126, in vitro. NMDA receptor activation is known to increase intracellular accumulation of Ca2+, resulting in up‐regulation of arachidonic acid (AA) metabolism. This can stimulate the lipoxygenase pathways that may generate a number of potentially neurotoxic metabolites. Because of the putative relationship between AA breakdown and PrP106‐126 neurotoxicity, we investigated AA metabolism in primary cerebellar granule neuron cultures treated with PrP106‐126. Our studies revealed that PrP106‐126 exposure for 30 min significantly up‐regulated AA release from cerebellar granule neurons. PrP106‐126 neurotoxicity was mediated through the 5‐lipoxygenase (5‐LOX) pathway, as shown by abrogation of neuronal death with the 5‐LOX inhibitors quinacrine, nordihydroguaiaretic acid, and caffeic acid. These inhibitors also prevented PrP106‐126‐induced caspase 3 activation and annexin V binding, indicating a central role for the 5‐LOX pathway in PrP106‐126‐mediated proapoptosis. Interestingly, inhibitors of the 12‐lipoxygenase pathway had no effect on PrP106‐126 neurotoxicity or proapoptosis. These studies clearly demonstrate that AA metabolism through the 5‐LOX pathway is an important early event in PrP106‐126 neurotoxicity and consequently may have a critical role in PrPTSE‐mediated cell loss in vivo. If this is so, therapeutic intervention with 5‐LOX inhibitors may prove beneficial in the treatment of prion disorders. J. Neurosci. Res. 65:565–572, 2001. © 2001 Wiley‐Liss, Inc.
Short‐term evolution of autoreactive T cell repertoire in multiple sclerosis
Authors: Vergelli M. , Mazzanti B. , Traggiai E. , Biagioli T. , Ballerini C. , Parigi A. , Konse A. , Pellicanò G. , Massacesi L.
Published: August 2002

T cells reactive to self‐antigens are present in the peripheral blood of patients with autoimmune diseases as well as in healthy subjects. Although T cell‐response to the self‐myelin antigen myelin basic protein (MBP) has been widely investigated in multiple sclerosis (MS) patients, very little is known about the evolution over time of this response and its correlation with the disease activity. In recent years magnetic resonance imaging (MRI) techniques have provided new tools for following the inflammatory activity in the central nervous system (CNS) of MS patients. In the present study the T cell response to MBP was longitudinally investigated in terms of frequency, epitope specificity, and cytokine production profile in four patients with relapsing‐remitting MS enrolled in a gadolinium‐enhanced MRI serial study. In spite of different profiles of inflammatory activity within the CNS, all the patients examined showed major changes in their reactivity to MBP during the follow‐up period in terms of both frequency and epitope specificity. Episodic expansions of MBP‐specific T cell populations were observed in each patient, and overall they did not correlate with disease activity. In these patients the expansions: 1) occurred in the context of a steady level of disease activity, 2) correlated with a burst of CNS inflammation, 3) followed the appearance of a new active lesion, and 4) were observed even in the absence of detectable signs of CNS inflammation during the entire follow‐up period. These results suggest that the evolution over time of the T cell response to a self‐antigen such as MBP is more complex than previously expected. The short‐term repertoire dynamics of autoreactive T cells in MS underscore the importance of longitudinal studies for evaluating autoreactivity to myelin antigens and probably to any self‐antigen in other autoimmune diseases. J. Neurosci. Res. 66:517–524, 2001. © 2001 Wiley‐Liss, Inc.
Constitutive overexpression of HSP-70 in thermal resistant tumor cells does not alter sensitivity to porphyrin-, chlorin-, or purpurin-mediated PDT
Authors: RUCKER NATALIE , FERRARIO ANGELA , GOMER CHARLES J.
Published: August 2002

Cellular expression of the 70 kDa heat shock protein (HSP-70) is observed following hyperthermia and is correlated with transient resistance to subsequent heating. Photodynamic therapy (PDT) mediated oxidative stress can also induce transcriptional and translational expression of a variety of genes including HSP-70. However, PDT-mediated HSP-70 expression can vary as a function of photosensitizer type and incubation conditions. In the current study we used three clinically relevant photosensitizers, a porphyrin (Photofrin), a purpurin (SnET2), and a chlorin (NPe6), to examine PDT-mediated HSP-70 expression profiles and photosensitivity characteristics in parental radiation-induced fibrosarcoma cells (RIF-1) and in thermal resistant RIF-1 clones. We observed that in vitro PDT treatments using either SnET2 or NPe6 induced HSP-70 expression but that comparable PDT treatments using Photofrin did not result in increased HSP-70 levels. We also observed that PDT sensitivity in parental and heat-resistant cell clones were similar for each photosensitizer while thermal sensitivity was significantly reduced in the RIF clones which constitutively overexpressed HSP-70. These results indicate that definable differences can exist in the molecular pathways induced by PDT for different photosensitizers. Our results also demonstrate that constitutive overexpression of HSP-70 does not modulate PDT photosensitivity regardless of whether PDT treatments induce HSP-70 expression. We conclude that HSP-70 expression does not play a significant role in cellular PDT photosensitivity.
Spectroscopic properties of p/p and o/o type iron(III)-metal-free porphyrin dimers and their catalysis as Cytochrome P450 model
Authors: REN QI-ZHI , HUANG JIN-WANG , ZHU ZHI-ANG , JI LIANG-NIAN , CHEN YUN-TI
Published: August 2002

Two series of p/p and o/o type iron(III)-metal-free porphyrin dimers were synthesized and characterized. The dimers consist of a ferric porphyrin and a free-base porphyrin, covalently linked with an alkoxy chain - O ( CH2)nO -(n = 2–10) at the para and ortho position of two phenyl rings. The ferric paramagnetic effect and ring current effect on these dimers were discussed by1H NMR study; vibration modes sensitive to the conformations of the dimers were investigated from IR spectra; the electron density and spin state of ferric ion were examined using XPS and EPR spectroscopy. The catalytic activities of p/p and o/o type dimers on the hydroxylation of cyclohexane were studied under mild conditions. As a chemical mimic model of Cyto. P450, these porphyrins exhibit higher catalytic activities than the corresponding monomer FeTPPCl . With increase of the carbon numbers of alkoxy chain, the catalytic activity order of p/p dimers is C 2 < C 3 < C 4 < C 5 < C 6 > C 8 > C 10, the corresponding order of o/o dimers is C 2 > C 4 > C 6 > C 8 > C 10. Catalytic results of dimers are shown to strongly depend on their special conformation equilibrium, which affect the steric hindrance and electron transfer between two porphyrin rings.
Preparation of monofunctional and phosphorescent palladium(II) and platinum(II) coproporphyrin labeling reagents
Authors: SOINI ALEKSI E. , YASHUNSKY DMITRI V. , MELTOLA NIKO J. , PONOMAREV GELII V.
Published: August 2002

A method is described for preparation of monosubstituted derivatives of platinum and palladium coproporphyrin-I. The method is based on chemical differentiation of one of the four alkoxycarbonyl groups of the starting coproporphyrin-I tetraalkyl ester by selective acid hydrolysis. The hydrolysis results after chromatographic purification to pure mono hydroxycarbonyl coproporphyrin, which can be subsequently coupled with a chemical species carrying a functional group of interest. The described method is used for preparation of phosphorescent metalloporphyrin labeling reagents having an isothiocyanato reactive group.
PDT-related photophysical properties of conformationally distorted palladium(II) porphyrins
Authors: WIEHE A. , STOLLBERG H. , RUNGE S. , PAUL A. , SENGE M. O. , RÖDER B.
Published: August 2002

The photodynamic therapy (PDT) related photophysical properties of five palladium(II) porphyrins with increasing steric demand of the meso-substituents were investigated by steady state and time-resolved absorption and luminescence spectroscopy. The steric strain of the meso-substituents is reflected in a bathochromic shift of the B-band in the absorption spectra. In contrast to free-base porphyrins, the palladium(II) complexes exhibit only a very weak fluorescence with Φ Fl ~ 10-4. Instead, the corresponding triplet states of the porphyrins are formed via inter system crossing (ISC) with a quantum yield ΦISC of nearly unity. A phosphorescence quantum yield ΦISC of 10-4 was determined assuming dynamic quenching. The triplet state of all compounds is efficiently quenched by molecular oxygen, generating singlet molecular oxygen with a quantum yield of ΦΔ ~ 0.85. The various substitution patterns exerted no significant influence on the ISC rates or singlet oxygen quantum yields. Significant differences, on the other hand, were observed with respect to the triplet lifetimes, with a tendency of longer lifetimes for the porphyrins with sterically more demanding substituents (in air-saturated solution). All porphyrins were successfully incorporated into liposomes. The phototoxic activity of three compounds was investigated in cell suspensions. The use of the new porphyrinato-palladium(II) in PDT applications is discussed.
Late Quaternary glaciation in Southern Africa: moraine ridges and glacial deposits at Mount Enterprise in the Drakensberg of the Eastern Cape Province, South Africa
Authors: Lewis Colin A. , Illgner Peter M.
Published: August 2002

Late Quaternary moraines and diamictons containing striated clasts are described from near Elliot in the Drakensberg of South Africa. An equilibrium line altitude (ELA) of 2109 m is suggested for the palaeoglacier associated with the innermost moraine. This glacier was fed by a very extensive snowblow area and the ELA may reflect the temperature–precipitation–wind ELA rather than the temperature–precipitation ELA and be considerably below the ‘regional’ ELA. Mean annual air temperatures when glaciation occurred were probably at least 10.0°C below those of the present. Copyright © 2001 John Wiley & Sons, Ltd.
Intraoperative and early postoperative chemotherapy into the abdominal cavity using gemcitabine may prevent postoperative occurence of peritoneal carcinomatosis
Authors: Ridwelski Karsten , Meyer Frank , Hribaschek Arndt , Kasper Udo , Lippert Hans
Published: August 2002

Background and Objectives

Malignant tumors of various abdominal organs are blamed to be the cause of death in approximately 40% of cases per year in Western Europe. At the time of death, about half of them show peritoneal carcinomatosis which is considered an unfavorable prognostic factor. In case of peritoneal carcinomatosis, there is no curative treatment available for any of the tumors in the abdominal cavity. The aim of this experimental study was to evaluate the preventive potential of intra‐operative or early postoperative local adminstration of gemcitabine into the abdominal cavity against peritoneal carcinomatosis.

Methods

Peritoneal carcinomatosis was induced in male WAG rats (n = 18) by transfer of 5 × 106 cells of the adenocarcinoma cell line CC‐531 via minilaparotomy carried out in all rats under general anesthesia. Thirty days after cell transfer, rats were sacrificed and peritoneal carcinomatosis was confirmed using histologic investigation in specimens obtained from the peritoneal site. Extension of this carcinomatosis was quantified by (i) counting tumor nodes per square centimeter (mean of several counts) and (ii) determining tumor weight (weight of the greater omentum plus the resected mesentery). Rats were subdivided into three groups (n = 6 per group): group 1 (controls); group 2, simultaneously with tumor cell transfer 24 mg/kg of gemictabine were administered into the abdominal cavity; group 3, postoperative intraperitoneal irrigation with 24 mg/kg of gemictabine was achieved via a previously implanted port‐a‐cath on days(d) 15, 21, and 27.

Results

On the 30th postoperative day, all six animals of the control group showed extensive tumor growth at the peritoneum and greater omentum, indicating carcinomatosis. In contrast, none of the rats of group 2 revealed any traces of intraperitoneal tumor growth. While all rats of group 3 demonstrated intraperitoneal tumor growth, but early postoperative treatment with gemcitabine, however, resulted in a significant reduction of the number of tumor nodes and tumor weight in comparison with group 1 (controls).

Conclusions

Immediate, i.e., simultaneous intraoperative application of a cytostatic agent such as gemcitabine into the abdominal cavity may completely prevent the generation of peritoneal carcinomatosis from occuring tumor cells, whereas early postoperative locoregional chemotherapy into the abdominal cavity can only reduce the severity of the peritoneal carcinomatosis. J. Surg. Oncol. 2002;79:10–16. © 2002 Wiley‐Liss, Inc.
Expression of neural cell adhesion molecules (polysialylated form of neural cell adhesion molecule and L1‐cell adhesion molecule) on resected small cell lung cancer specimens: In relation to proliferation state
Authors: Miyahara Ryo , Tanaka Fumihiro , Nakagawa Tatsuo , Matsuoka Katsunari , Isii Kazuhiro , Wada Hiromi
Published: August 2002

Background and Objectives:

Alteration of homotypic cell–cell adhesion has been suggested to play an important role in tumor progression. The present study examined the relationship between neural cell adhesion molecules and state of proliferation of small cell lung cancer (SCLC) cells.

Methods:

Seventeen surgically resected specimens of SCLC were immunohistochemically examined, by using monoclonal antibodies against neural cell adhesion molecule (NCAM) and its polysialic acid side chains, and L1 cell adhesion molecule (L1‐CAM). Ki‐67 labeling indices were also determined immunohistochemically.

Results:

All patients were positive for L1‐CAM. Fifteen patients (88.2%) were positive for NCAM. Among the fifteen patients, nine (60.0%) were positive for NCAM PSA side chain. The probability of survival of the NCAM without PSA side chain group was significantly higher than that of the NCAM with PSA side chain group (log‐rank test; P = 0.500).

Conclusions:

The expression of NCAM with PSA side chains might be a prognostic factor and NCAM a marker for SCLC. L1‐CAM may be synthesized independent of state of proliferation of individual tumor cell and may affect clinical feature of SCLC. J. Surg. Oncol. 2001; 77:49–54. © 2001 Wiley‐Liss, Inc.
Mucinous adenocarcinoma arising in a neovagina using the sigmoid colon thirty years after operation: A case report
Authors: Hiroi Hisahiko , Yasugi Toshiharu , Matsumoto Koji , Fujii Tomoyuki , Watanabe Toshiaki , Yoshikawa Hiroyuki , Taketani Yuji
Published: August 2002

Background:

Because of a relative rarity of the cases with an artificial vagina, the incidence of a case with malignant disease arising in the neovagina is extremely rare. A case of adenocarcinoma arising from a neovagina is presented with a review of the literature.

Case:

A neovagina was constructed using the sigmoid colon at the age of 23 for congenital agenesis of the vagina, Rokitansky–Küster–Hauser syndrome. Subsequently, the patient had regular sexual intercourse for about 20 years. At the age of 53, she came to our outpatient clinic with a complaint of vaginal bleeding, and adenocarcinoma was found at the anterior wall of the neovagina adjoining the introitus. Total resection of the neovagina and adjuvant radiotherapy was performed. The pathological diagnosis was mucinous adenocarcinoma.

Conclusions:

In view of relatively low incidence of mucinous carcinoma arising in the sigmoid colon along with the ectopic localization, this case may have implications for the understanding of pathogenesis of sigmoid colon cancer. J. Surg. Oncol. 2001; 77:61–64. © 2001 Wiley‐Liss, Inc.
Influence of solvent structure on the aquation of K‐chloro(diethylenetriamine)(ethylenediamine) cobalt(III) ion in water and mixed aqueous solvents
Authors: El‐Subruiti Gehan M. , Chehata Aziza K. , Massoud Salah S.
Published: August 2002

The aquation of K‐[Co(dien)(en)Cl]2+ was followed spectrophotometrically within the temperature range (40–60°C) in water, water–isopropyl alcohol, and water–tert‐butyl alcohol media of varying solvent composition up to 50 and 60 vol% of the organic solvent component respectively. The nonlinear plot of log k vs. D−1s was attributed to the differential solvation of the initial and transition states. The variation of ΔH≠, ΔS≠, and ΔG≠ with the mole fraction of the organic component was analyzed and discussed. The isokinetic temperatures were found to be 330 and 317 K for water–isopropyl alcohol and water–tert‐butly alcohol mixtures respectively, indicating that the aquation reaction is entropy controlled. The application of free energy cycle at 25°C for the aquation reaction in both co‐solvents suggests that the transition state is more stable than the initial one. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 1–6, 2002
Kinetics and mechanism of thermal gas‐phase elimination of 2‐aryloxyacetic acid
Authors: Al‐Awadi Nouria A. , Kumar Ajith , Chuchani Gabriel , Herize Armando
Published: August 2002

Rates of thermal gas‐phase elimination of eleven 2‐aryloxyacetic acid have been measured over a 45°C temperature range for each compound. Hammett correlation of the present kinetic data with the literature σ0 values of the given substituents gave a reaction ρ constant of 0.69 at 600 K; this is more than that for the gas‐phase elimination parameter of 2‐aryloxypropanoic acid (ρ = 0.26) and consistent with a transition state with some charge separation, suggesting a partial formation of carbocation. The implications of this observation for the thermal gas‐phase elimination of α‐aryloxycarboxylic acids are considered. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 612–616, 2001
Anatomy of a failed knowledge management initiative: lessons from PharmaCorp's experiences
Authors: Braganza Ashley , Möllenkramer Gerald J.
Published: August 2002

On a sunny morning in July 1999, Samuel Parsons, Head of Knowledge Management at PharmaCorp, convened his regular Monday team meeting. He looked stressed. After dealing with a couple of administrative issues he said: ‘Last Friday evening I was informed that Wilco Smith, Head of Pharma Global Order Handling Services, no longer wants knowledge management. His only question now is how to off‐board the knowledge management staff.’ Thus came to an end a three‐year initiative that at the outset was considered to be ‘theknowledge management showcase for the firm’. This paper is for managers who have an interest in operationalizing knowledgeandwant to avoid the traps others have fallen into. It examines the case of PharmaCorp, a global organization and one of the largest in its industry. The case provides managers with five key lessons. First, manage knowledge interdependencies across communities of practice; second, contextualize knowledge within natural groups of activities; third, avoid an over‐emphasis on explicit knowledge; fourth, let knowledge management recipients determine tacit and explicit knowledge; and fifth, manage the input from external consultants. Copyright © 2002 John Wiley & Sons, Ltd.