bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionic Self‐Assembly: Facile Synthesis of Supramolecular Materials
Authors: Faul C.F.J. , Antonietti M.
Published: April 2003

The technique of ionic self‐assembly, i.e., the coupling of structurally different building blocks by electrostatic interactions, a powerful tool to create new material nanostructures and chemical objects, is reviewed. The excellent availability of the starting products (charged tectonic units) and the simplicity of synthesis, by neat addition and cooperative stoichiometric precipitation with high purity, allow the recombinatorial synthesis of a whole range of functional materials and hybrids with interesting and versatile functions. Diverse combinations between polyelectrolytes, surfactants, clusters, and extended rigid organic scaffolds are discussed in detail, and the underlying principles of nanostructure formation are illustrated.
Synthesis of polyetherols from melamine and propylene carbonate. II
Authors: Kucharski Mieczysław , Kijowska Dorota
Published: April 2003

Results of the reaction of melamine with propylene carbonate in the synthesis of polyetherols with 1,3,5‐triazine rings are presented. Optimal conditions of synthesis of the polyetherols are presented and the products characterized by determining selected physical properties and by using spectral methods [1H‐NMR, IR, mass spectroscopy (MS) electrospray ionization (ESI)]. The content of side products was established by GLC. The resulting polyetherols have been found suitable for preparation of polyurethane foams of improved thermal stability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 104–115, 2003
Effects of aromatic groups in polymer chains on plasma surface modification
Authors: Inagaki N. , Narushima K. , Lim S. K.
Published: April 2003

Three polyester films with different repeating units—poly(lactic acid) (PLA), poly(ethylene terephthalate) (PET), and poly(oxybenzoate‐co‐oxynaphthoate) (PBN)—were modified by plasma, and the way in which the chemical compositions of the polymer chains influenced the plasma modification was investigated with contact‐angle measurements and X‐ray photoelectron spectroscopy (XPS). There were large differences in the compensated rates of weight loss among the three polyester films when they were exposed to Ar and O2 plasmas. The PLA film showed the highest rate for weight loss of the three films, and the PBN film showed the lowest rate. The PET and PBN film surfaces were modified to become more hydrophilic by either argon or oxygen plasma. However, the PLA film surface was not made more hydrophilic by the plasmas. XPS spectra showed that the PLA film surface was not modified in its chemical composition, but the PBN film surface was modified in its chemical composition to form CO groups in the PBN polymer chains. The reason that the PLA film surface was not modified but the PBN film surface was modified was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 96–103, 2003
USDA Stakeholder Workshop on Animal Bioinformatics: summary and recommendations
Authors: Hamernik Debora L. , Adelson David L.
Published: April 2003

An electronic workshop was conducted on 4 November–13 December 2002 to discuss current issues and needs in animal bioinformatics. The electronic (e‐mail listserver) format was chosen to provide a relatively speedy process that is broad in scope, cost‐efficient and easily accessible to all participants. Approximately 40 panelists with diverse species and discipline expertise communicated through the panel e‐mail listserver. The panel included scientists from academia, industry and government, in the USA, Australia and the UK. A second ‘stakeholder’ e‐mail listserver was used to obtain input from a broad audience with general interests in animal genomics. The objectives of the electronic workshop were: (a) to define priorities for animal genome database development; and (b) to recommend ways in which the USDA could provide leadership in the area of animal genome database development. E‐mail messages from panelists and stakeholders are archived at http://genome.cvm.umn.edu/bioinfo/. Priorities defined for animal genome database development included: (a) data repository; (b) tools for genome analysis; (c) annotation; (d) practical application of genomic data; and (e) a biological framework for DNA sequence. A stable source of funding, such as the USDA Agricultural Research Service (ARS), was recommended to support maintenance of data repositories and data curation. Continued support for competitive grants programs within the USDA Cooperative State Research, Education and Extension Service (CSREES) was recommended for tool development and hypothesis‐driven research projects in genome analysis. Additional stakeholder input will be required to continuously refine priorities and maximize the use of limited resources for animal bioinformatics within the USDA. Copyright © 2003 John Wiley & Sons, Ltd.
Localization of [3H]nicotine, [3H]cytisine, [3H]epibatidine, and [125I]α‐bungarotoxin binding sites in the brain of Macaca mulatta
Authors: Han Zhi‐Yan , Zoli Michele , Cardona Ana , Bourgeois Jean‐Pierre , Changeux Jean‐Pierre , Le Novère Nicolas
Published: April 2003

We determined the localization of [3H]nicotine, [3H]cytisine, [3H]epibatidine, and [125I]α‐bungarotoxin binding sites in the brain of rhesus monkey by means of receptor autoradiography. The labelings by [3H]nicotine, [3H]cytisine, and [3H]epibatidine were highly concordant, except for epibatidine. Layer IV of some cortical areas, most thalamic nuclei, and presubiculum displayed high levels of labeling for the three ligands. Moderate levels of binding were detected in the subiculum, the septum, and the mesencephalon. Low levels were present in layers I–II and VI of the cortex, the cornu Ammonis, the dentate gyrus, and the amygdala. In addition, the level of epibatidine labeling was very high in the epithalamic nuclei and the interpeduncular nucleus, whereas labeling by nicotine and cytisine was very weak in the same regions. The distribution of [125I]α‐bungarotoxin binding differed from the binding of the three agonists. The labeling was dense in layer I of most cortical areas, dentate gyrus, stratum lacunosum‐moleculare of CA1 field, several thalamic nuclei, and medial habenula. A moderate labeling was found in layers V and VI of the prefrontal and frontal cortices, layer IV of primary visual cortex, amygdala, septum, hypothalamus, and some mesencenphalic nuclei. A weak signal was also detected in subiculum, claustrum, stratum oriens, and stratum lucidum of cornu Ammonis and also in some mesencephalic nuclei. The distribution of nicotine, cytisine, and epibatidine bindings corresponds broadly to the patterns observed in rodents, with the marked exception of the epithalamus. However, in monkey, those distributions match the distribution of α2 messenger RNA, rather than that of α4 transcripts as it exists in rodent brains. The distribution of the binding sites for α‐bungarotoxin is larger in the brain of rhesus monkeys than in rodent brain, suggesting a more important role of α7 receptors in primates. J. Comp. Neurol. 461:49–60, 2003. © 2003 Wiley‐Liss, Inc.
Morphology, axonal projection pattern, and responses to optic nerve stimulation of thalamic neurons in the fire‐bellied toad Bombina orientalis
Authors: Roth Gerhard , Grunwald Wolfgang , Dicke Ursula
Published: April 2003

Intracellular recording and biocytin labeling were carried out in the fire‐bellied toad Bombina orientalis to study the morphology and axonal projections of thalamic (TH) neurons and their responses to electrical optic nerve stimulation. Labeled neurons (n = 142) were divided into the following groups: TH1 neurons projecting to the dorsal striatum; TH2 neurons projecting to the amygdala, nucleus accumbens, and septal nuclei; TH3 neurons projecting to the medial or dorsal pallium; TH4 neurons with projections ascending to the dorsal striatum or ventral striatum/amygdala and descending to the optic tectum, tegmentum, and rostral medulla oblongata; TH5 neurons with projections to the tegmentum, rostral medulla oblongata, prectectum, or tectum; and TH6 neurons projecting to the hypothalamus. TH1 neurons are found in the central, TH2 neurons in the anterior and central, TH3 neurons in the anterior dorsal nucleus, and TH4 and TH5 neurons in the posterior dorsal or ventral nucleus. Neurons with descending projections arborize in restricted parts of retinal afferents; neurons with ascending projections do not substantially arborize within retinal afferents. At electrical optic nerve stimulation, neurons in the ventral thalamus respond with excitation at latencies of 10.8 msec; one‐third of them follow repetitive stimulation and possibly are monosynaptically driven. Neurons in the dorsal thalamus respond mostly with inhibition at latencies of 42.3 msec and are polysynaptically driven. This corroborates the view that neurons in the dorsal thalamus projecting to the telencephalon receive no substantial direct retinal input and that the thalamopallial pathway of amphibians is not homologous to the mammalian retinogeniculocortical pathway. J. Comp. Neurol. 461:91–110, 2003. © 2003 Wiley‐Liss, Inc.
Executive cognitive deficits in primary dystonia
Authors: Scott Richard B. , Gregory Ralph , Wilson Joanna , Banks Sarah , Turner Anna , Parkin Simon , Giladi Nir , Joint Carol , Aziz Tipu
Published: April 2003

Primary dystonia is a disorder of movement for which no consistent pathophysiology has been identified; in the absence of evidence to the contrary, it is assumed to be cognitively benign. We have studied a clinically heterogeneous group of 14 patients with primary dystonia on a battery of neuropsychological tests. Despite well‐preserved speed of information processing, language, spatial, memory and general intellectual skills relative to normal controls, we have identified a constellation of attentional–executive cognitive deficits on the Cambridge Neuropsychological Test Automated Battery (CANTAB). Specifically, patients demonstrated significant difficulties negotiating the extra‐dimensional set‐shifting phase of the IED task. The implications of these findings for the pathophysiology of primary dystonia are discussed. This is, to the best of our knowledge, the first report of a significant cognitive deficit in patients with primary dystonia. © 2003 Movement Disorder Society
Clinical and economic analysis of spa therapy in Parkinson's disease
Authors: Brefel‐Courbon Christine , Desboeuf Karine , Thalamas Claire , Galitzky Monique , Senard Jean‐Michel , Rascol Olivier , Montastruc Jean‐Louis
Published: April 2003

The effectiveness of spa therapy in the management of patients with Parkinson's disease (PD) has never been evaluated. This is assessed in this pilot study. A prospective, randomized, cross‐over, controlled study was conducted in 31 PD patients who underwent a 20‐week spa period, including spa therapy for 3 weeks, and a 20‐week non‐spa period. Effectiveness was assessed using quality of life scales (PDQ‐39 and SF‐36), motor scale (UPDRS) and psychological questionnaire (GHQ‐28), at baseline and at 4 (T4) and at 20 weeks (T20). Direct medical costs (radiological and laboratory tests, physician fees, drug therapy, and ancillary care) were recorded over each 20‐week period. At T4, spa therapy improved significantly several dimensions of PDQ‐39 and SF‐36, part IV of the UPDRS, and GHQ‐28. At T20, no difference in any parameter was found. The mean direct medical cost over 20 weeks (€1,328 ± 167; £776 ± 97 per patient) in the spa period was slightly but significantly reduced in comparison with that of the non‐spa period (€1380 ± 523; £807 ± 306 per patient). This cost‐effectiveness analysis suggests that spa therapy is more effective and less expensive than conventional treatment alone and could be beneficial in the management of PD.
SIC Task Force appraisal of clinical diagnostic criteria for parkinsonian disorders
Authors: Litvan Irene , Bhatia Kailash P. , Burn David J. , Goetz Christopher G. , Lang Anthony E. , McKeith Ian , Quinn Niall , Sethi Kapil D. , Shults Cliff , Wenning Gregor K.
Published: April 2003

As there are no biological markers for the antemortem diagnosis of degenerative parkinsonian disorders, diagnosis currently relies upon the presence and progression of clinical features and confirmation depends on neuropathology. Clinicopathologic studies have shown significant false‐positive and false‐negative rates for diagnosing these disorders, and misdiagnosis is especially common during the early stages of these diseases. It is important to establish a set of widely accepted diagnostic criteria for these disorders that may be applied and reproduced in a blinded fashion. This review summarizes the findings of the SIC Task Force for the study of diagnostic criteria for parkinsonian disorders in the areas of Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration. In each of these areas, diagnosis continues to rest on clinical findings and the judicious use of ancillary studies. © 2003 Movement Disorder Society
Entanglement experiments in cavity QED
Authors: Haroche S.
Published: April 2003

A review of recent experiments performed with Rydberg atoms and microwave photons in high Q cavities is presented, which illustrate fundamental aspects of quantum physics such as entanglement, complementarity and decoherence. The relevance of these experiments for quantum information processing is also discussed.
Secoiridoid glucosides with free radical scavenging activity from the leaves of Syringa dilatata
Authors: Oh Hyuncheol , Ko Eun‐Kyoung , Kim Do‐Hoon , Jang Kyu‐Kwan , Park Sung‐Eun , Lee Ho‐Sub , Kim Youn‐Chul
Published: April 2003

Activity‐guided fractionation of the EtOAc and MeOH extract of the leaves of Syringa dilatata NAKAI furnished one free radical scavenger, the secoiridoid glucoside oleuropein together with ligstroside and an iridoid glucoside, syringopicroside. Oleuropein interacted with the stable free radical, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), and showed an IC50 value of 40.4 µM. L‐Ascorbic acid as a positive control showed an IC50 value of 50.3 µM. Copyright © 2003 John Wiley & Sons, Ltd.
Cryptolepine hydrochloride: a potent antimycobacterial alkaloid derived from Cryptolepis sanguinolenta
Authors: Gibbons Simon , Fallah Fatemeh , Wright Colin W.
Published: April 2003

The activity of cryptolepine hydrochloride, a salt of the main indoloquinoline alkaloid from the West African medicinal plant Cryptolepis sanguinolenta, was assessed against the fast growing mycobacterial species Mycobacterium fortuitum, which has recently been shown to be of use in the evaluation of antitubercular drugs. The low minimum inhibitory concentration (MIC) of this compound (16 µg/mL) prompted further evaluation against other fast growing mycobacteria namely, M. phlei, M. aurum, M. smegmatis, M. bovis BCG and M. abcessus and the MICs ranged over 2–32 µg/mL for these species. The strong activity of this agent, the need for new antibiotics with activity against Mycobacterium tuberculosis, coupled with the ethnobotanical use of C. sanguinolenta extracts to treat infections, highlight the potential of the cryptolepine template for development of antimycobacterial agents. Copyright © 2003 John Wiley & Sons, Ltd.
Estimation of dolichol and cholesterol synthesis in microsomes and peroxisomes isolated from rat liver
Authors: Grünler Jacob , Olsson Jerker M. , Dallner Gustav
Published: April 2003

The participation of peroxisomal and microsomal fractions from rat liver in dolichol and cholesterol synthesis was investigated using marker enzymes. Recovery was 8% for peroxisomes and 33% for microsomes, with virtually no cross‐contamination between these fractions. Using these data, it was calculated that the peroxisomal branch‐point enzyme activities for dolichol and cholesterol biosynthesis, i.e. cis‐prenyltransferase and squalene synthase, were 25% and 12%, respectively, of the total homogenate activity. Treatment with mevinolin increased the peroxisomal contribution in the case of both enzymes, to levels almost equal to that of their microsomal counterparts. These results indicate that peroxisomes play a role in the biosynthesis of isoprenoid lipids and that the extent of this participation is increased extensively when peroxisomes are induced by various treatments.
Structure‐function relationships of cation translocation by Ca2+‐ and Na+,K+‐ATPases studied by site‐directed mutagenesis
Authors: Anderssen Jens Peter , Vilsen Bente
Published: April 2003

Site‐directed mutagenesis studies of the sarcoplasmic reticulum Ca2+‐ATPase have pinpointed five amino acid residues that are essential to Ca2+ occlusion, and these residues have been assigned to different parts of a Ca2+ binding pocket with channel‐like structure. Three of the homologous Na+,K+‐ATPase residues have been shown to be important for binding of cytoplasmic Na+ at transport sites. In addition, three of the above mentioned Ca2+‐ATPase residues appear to participate in the countertransport of H+, and two of the Na+,K+‐ATPase residues to participate in the countertransport of K+. Residues involved in energy transducing conformational changes have also been identified by mutagenesis. In the Ca2+‐ATPase, ATP hydrolysis is uncoupled from Ca2+ transport following mutation of a tyrosine residue located at the top of transmembrane segment M5. This tyrosine, present also in the Na+,K+‐ATPase, may play a critical role in closing the gate to a transmembrane channel.
Protein kinase C activator inhibits voltage‐sensitive Ca2+ channels and catecholamine secretion in adrenal chromaffin cells
Authors: Sena Cristina M. , Tomé Angelo R. , Santos Rosa M. , Rosário Luís M.
Published: April 2003

We have investigated the effects of the phorbol ester 12‐myristate 13‐acetate (PMA) on depolarization‐evoked Ca2+ influx and catecholamine secretion in bovine adrenal chromaffin cells. PMA (100 nM) strongly inhibited K+‐evoked [Ca2+]i transients and Mn2+ quenching of fura‐2 fluorescence. In contrast, 4α‐phorbol 12,13‐didecanoate, a phorbol ester inactive on protein kinase C (PKC), had no effect. Maximal PMA‐mediated inhibition occurred at 5–10 min incubations and were variable from cell to cell, ranging from 25 to 65% of controls. The [Ca2+]i transients evoked by the L‐type Ca2+ channel activator Bay K 8644 were strongly inhibited by 100 nM PMA. PMA (0.1–10 μM) inhibited K+‐evoked adrenaline and noradrenaline release by 23–44%. The data indicate that phorbol ester‐mediated activation of PKC inhibits voltage‐sensitive Ca2+ channels in chromaffin cells, leading to a prominent depression of depolarization‐evoked catecholamine secretion.
The MAP kinase signal transduction pathway is activated by the endogenous cannabinoid anandamide
Authors: Wartmann Markus , Campbell Debra , Subramanian Asha , Burstein Sumner H. , Davis Roger J.
Published: April 2003

Anandamide is an endogenous ligand for δ9‐tetrahy‐drocannabinol (THC) receptors. Incubation of cultured cells with anandamide or THC causes increased arachidonic acid release and eicosanoid biosynthesis. Here we demonstrate that the MAP kinase signal transduction pathway contributes to this response. Treatment of WI‐38 fibroblasts with anandamide causes increased MAP kinase activity and increased phosphorylation of the arachidonate‐specific cytoplasmic phospholipase A2 (cPLA2). Significantly, MAP kinase phosphorylates and activates cPLA2 [Lin, et al., Cell, 72 (1993) 269–278]. The MAP kinase signal transduction pathway may therefore mediate the effects of anadamide on cPLA2 activation and arachidonic acid release.
Low frequency MFs increased inositol 1,4,5‐trisphosphate levels in the Jurkat cell line
Authors: Korzh-Sleptsova I.L. , Lindström E. , Hansson Mild K. , Berglund A. , Lundgren E.
Published: April 2003

We have earlier reported that when a weak 50 Hz MF (magnetic field) was applied, the leukemic T‐cell line Jurkat responded with intracellular calcium oscillations [Lindström, et al., J. Cell Physiol., 156 (1993) 395–398]. The result suggested that the MF interfered with the signal transduction, although neither target molecules nor molecular mechanisms are at present known. In this study we found that application of a MF to Jurkat cells resulted in significant increase of inositol 1,4,5‐trisphosphate (IP3) levels. Chelation of intracellular calcium ions by BAPTA/AM, did not block the increase of IP3 induced by MF. This result implied that MF‐induced Ca2+ oscillations were not due to direct stimulation of the Ca2+‐dependent phospholipase C‐γ1 (PLC‐γ1).
Novel guanylyl cyclase inhibitor, ODQ reveals role of nitric oxide, but not of cyclic GMP in endothelin‐1 secretion
Authors: Brunner Friedrich , Stessel Heike , Kukovetz Walter R.
Published: April 2003

The role of nitric oxide (NO) and guanosine 3′,5′‐cyclic monophosphate (cyclic GMP) in cellular regulation of endothelin‐1 (ET‐1) secretion was investigated in cultured porcine aortic endothelial cells. NO synthase was inhibited with (l‐NNA) and guanylyl cyclase with the novel selective inhibitor, ODQ (1H‐[1,2,4]oxadiazolo[4,3,‐a]quinoxalin‐1‐one) (3 μM). Basal and phorbol ester (PMA)‐stimulated ET‐1 secretion were unaffected by ODQ, but stimulated secretion was increased by l‐NNA. In the presence of the NO donors, spermine/ NO, S‐nitroso‐glutathione (GSNO), and nitroprusside (NP) ET‐1 secretion was reduced, but ODQ had no effect on this inhibition, although it effectively inhibited cyclic GMP production. NO release from donors, measured with a sensitive NO electrode, was greatest for spermine/NO, intermediate for GSNO, minimal for NP and paralleled inhibition of ET‐1 secretion. The data suggest that in cultured endothelial cells, curtailment of ET‐1 secretion is mediated by NO and independent of cyclic GMP.
Transport properties of the multidrug resistance‐associated protein (MRP) in human tumour cells
Authors: Holló Zsolt , Homolya László , Hegedüs Tamás , Sarkadi Balázs
Published: April 2003

In this paper we demonstrate that the expression of the multidrug resistance‐associated protein (MRP) in a variety of intact human tumour cells results in the ATP‐dependent, mutually exclusive extrusion of both the acetoxymethyl ester and the free anion forms of the fluorescent dye calcein, as well as that of a fluorescent pyrenemaleimide‐glutathione conjugate. The MRP‐dependent transport of all these three model compounds closely correlates with the expression level of MRP and is cross‐inhibited by hydrophobic anticancer drugs, by reversing agents for MDR1, and also by compounds not influencing MDR1, such as hydrophobic anions, alkylating agents, and inhibitors of organic anion transporters. Cellular glutathione depletion affects neither the MRP‐dependent extrusion of calcein AM or free calcein, nor its modulation by most hydrophobic or anionic compounds, although eliminating the cross‐inhibitory effect of glutathione conjugates. These results suggest that the outward pumping of both hydrophobic uncharged and water‐soluble anionic compounds, including glutathione conjugates, is an inherent property of MRP, and offer sensitive methods for the functional diagnostics of this transport protein as well as for the rapid screening of drug‐resistance modulating agents.
Characterization and gene expression of an annexin during fruit development in Capsicum annuum
Authors: Proust Jézabel , Houlné Guy , Schantz Marie-Luce , Schantz Rodolphe
Published: April 2003

Several lines of evidence indicate that annexins, as calcium‐dependent phospholipid‐binding proteins, are involved in a variety of plant cellular processes. We were interested in determining if annexins are implicated in the highly regulated fruit development of bell pepper. By differential screening of several cDNA libraries, we isolated a full‐length cDNA of 1180 bp encoding an annexin. Northern blot analyses show a differential expression pattern of the transcripts during the early stages of development and during ripening. Immunoblots using antiserum raised against p33/p35 from maize reveal that cross‐reactive polypeptides of about 30 kDa are present at each stage of fruit development in bell pepper. We partially purified the annexins from seedlings and green fruits. At least one annexin of 32 kDa is present in these plant tissues.
Adrenal chromaffin cells contain functionally different SNAP‐25 monomers and SNAP‐25/syntaxin heterodimers
Authors: Höhne-Zell Barbara , Gratzl Manfred
Published: April 2003

Syntaxin and SNAP‐25 (synaptosome‐associated protein of 25 kDa), associated with the neuronal plasmalemma, and synaptobrevin, a membrane protein of synaptic vesicles, are essential components of the exocytotic apparatus of synaptic vesicles. All three can be proteolytically cleaved by tetanus and/or botulinum neurotoxins. As a consequence of their cleavage, exocytosis of neurotransmitters is blocked. In adrenal chromaffin cells botulinum neurotoxin A only incompletely inhibits exocytosis. This incomplete inhibition of exocytosis is associated with only partial cleavage of SNAP‐25 by the toxin, indicating that distinct pools of SNAP‐25 may exist in chromaffin cells which differ in their sensitivities to botulinum neurotoxin A. In line with this result we localized SNAP‐25 by immunogold electron microscopy not only to the plasmalemma but also to the chromaffin vesicle membrane. Moreover, in addition to SNAP‐25 monomers, stable SNAP‐25/syntaxin heterodimers were found in chromaffin cells. Subfractionation studies revealed the presence of SNAP‐25/syntaxin heterodimers in an enriched fraction of chromaffin vesicles. This complex proved to be stable in SDS, and SNAP‐25 within heterodimers was resistant to proteolytic attack by botulinum neurotoxin A. We suggest that these preexisting heterodimers may serve as receptors of soluble NSF attachment proteins (SNAP receptors) during chromaffin vesicle exocytosis.
Cloning, molecular analysis and insertional mutagenesis of the bidirectional hydrogenase genes from the cyanobacterium Anacystis nidulans
Authors: Boison Gudrun , Schmitz Oliver , Mikheeva Lidia , Shestakov Sergey , Bothe Hermann
Published: April 2003

Among cyanobacteria, the heterocystous, N2‐fixing Anabaena variabilis and the unicellular Anacystis nidulans have recently been shown to possess an NAD+‐dependent, bidirectional hydrogenase. A 5.0 kb DNA segment of the A. nidulans genome is now identified to harbor the structural genes hoxUYH coding for three subunits of the bidirectional hydrogenase. The gene arrangement in A. nidulans and in A. variabilis is remarkably dissimilar. In A. nidulans, but not in A. variabilis, the four accessory genes hoxW, hypA, hypB and hypF could be identified downstream of hoxH. An insertional homozygous mutant in hoxH from A. nidulans was completely inactive in performing Na2S2O4‐dependent H2 evolution but could utilize the gas with almost 50% of the activity of the wild type. These findings with the first defined hydrogenase mutant in any photosynthetic, O2‐evolving microorganism indicate that the unicellular cyanobacterium A. nidulans possesses both an uptake and a bidirectional hydrogenase. The physiological role(s) of the two hydrogenases in unicellular non‐N2‐fixing cyanobacteria is not yet understood.
p42 MAPK phosphorylates 80 kDa MARCKS at Ser‐113
Authors: Schp̈nwaβer Dorothee C. , Palmer Ruth H. , Herget Thomas , Parker Peter J.
Published: April 2003

It is demonstrated here that p42 MAPKinase (p42 MAPK) phosphorylates the yristoylated lanine‐ich ‐inase ubstrate (MARCKS) at Ser‐113. In permeabilised Swiss 3T3 cells activation of protein kinase C (PKC) leads to p42 MAPK activation, but only the protein kinase C sites in MARCKS become phosphorylated and not Ser‐113. The mitogen platelet‐derived growth factor (PDGF) elicits the same response. These results demonstrate that while Ser‐113 is a substrate for p42 MAPK in vitro and can be phosphorylated in vivo as shown by Taniguchi et al. [(1994) J. Biol. Chem. 269, 18299–18302], its phosphorylation is not subject to acute regulation by p42 MAPK in Swiss 3T3 cells.
The mitogenic effect of H2O2 for vascular smooth muscle cells is mediated by an increase of the affinity of basic fibroblast growth factor for its receptor
Authors: Herbert Jean-Marc , Bono Fran¢oise , Savi Pierre
Published: April 2003

Increased generation of active oxygen species such as hydrogen peroxide (H2O2) may be important in vascular smooth muscle cell growth associated with atherosclerosis and restenosis. In this work, we showed that H2O2 was a potent mitogen for growth‐arrested cultured human aortic smooth muscle cells (SMC), stimulating an increase in cell number at 10 nM to 100 μM concentration. This effect was inhibited in a dose‐dependent manner by catalase, deferoxamine, dimethylthiourea or probucol showing that it was dependent on the oxidative activity of H2O2. H2O2‐induced SMC proliferation was strongly and specifically inhibited by a neutralizing monoclonal antibody directed against basic fibroblast growth factor (bFGF) but was not due to increased expression of bFGF or the bFGF receptor‐1 (FGFR‐1) by SMC. H2O2 strongly increased the affinity of bFGF for its receptor‐1 at the surface of the SMC, therefore showing that the mitogenic effect of H2O2 might occur through a direct effect on the bFGF receptor.
Pharmacology of Ca2+ release from red beet microsomes suggests the presence of ryanodine receptor homologs in higher plants
Authors: Muir Shelagh R. , Sanders Dale
Published: April 2003

Cyclic ADP‐ribose (cADPR) is known to release Ca2+ from plant vacuoles, implying that this NAD+ metabolite may possess a second messenger role in plants. The degree to which the plant cADPR‐gated Ca2+ release mechanism resembles cADPR action in animals has been evaluated. cADPR‐elicited Ca2+ release from red beet microsomes was inhibited by 1 mM procaine but insensitive to heparin. Furthermore, pre‐release of Ca2+ from red beet vesicles by either 5 mM caffeine or micromolar levels of ryanodine precluded further Ca2+ mobilisation by cADPR. Thus, this study argues strongly for conservation between the plant and animal cADPR‐elicited Ca2+ release mechanisms.
Structural characterization of recombinant domain II of the basement membrane proteoglycan perlecan
Authors: Costell Mercedes , Sasaki Takako , Mann Karlheinz , Yamada Yoshihiko , Timpl Rupert
Published: April 2003

Mouse perlecan domain II (325 residues), consisting of four cysteine‐rich LA modules, one IG module and a link region, was obtained in purified form from a stably transfected mammalian cell clone. Rotary shadowing electron microscopy demonstrated a globular domain connected to a short rod‐like segment of variable length. This suggested that tandem arrays of LA modules form rod‐like elements. Folding into a native structure was indicated by the sharing of immunological epitopes with tissue perlecan, a CD spectrum demonstrating 37% β structure and a limited susceptibility to proteolysis. The domain also showed N‐glycosylation of a single acceptor site and 7–8 O‐linked oligosaccharides. The latter were located mainly in the link region within proline‐rich sequences.
Identity elements of Thermus thermophilus tRNAThr
Authors: Nameki Nobukazu , Asahara Haruichi , Hasegawa Tsunemi
Published: April 2003

In this study, we identified nucleotides that specify aminoacylation of tRNAThr by Thermus thermophilus threonyl‐tRNA synthetase (ThrRS) using in vitro transcripts. Mutation studies showed that the first base pair in the acceptor stem as well as the second and third positions of the anticodon are major identity elements of T. thermophilus tRNAThr, which are essentially the same as those of Escherichia coli tRNAThr. The discriminator base, U73, also contributed to the specific aminoacylation, but not the second base pair in the acceptor stem. These findings are in contrast to E. coli tRNAThr, where the second base pair is required for threonylation, with the discriminator base, A73, playing no roles. In addition, among several mutations at the third base pair in the acceptor stem, only the G3‐U70 mutant was a poor substrate for ThrRS, suggesting that the G3‐U70 wobble pair, which is the identity determinant of tRNAAla, acts as a negative element for ThrRS. Similar results were obtained in E. coli and yeast. Thus, this manner of rejection of tRNAAla is also likely to have been retained in the threonine system throughout evolution.
Expression of chloride channel 1 mRNA in cultured myogenic cells: a marker of myotube maturation
Authors: Bardouille Claudia , Vullhorst Detlef , Jockusch Harald
Published: April 2003

The chloride channel ClC‐1 is required to maintain a normal excitability of mature muscle fibers; its blockade leads to hyperexcitability, the hallmark of the disease myotonia. In mouse and rat myotubes, representing the embryonic stage of muscle, ClC‐1 mRNA is not detectable by Northern blotting. From neonatal to adult, ClC‐1 expression increases at least fourfold. Using RT‐PCR and hybridization on cultured myotubes were found ClC‐1 mRNA at a level of 0.4–1.1% of that in mature mouse muscle, and ≤0.01% in myoblasts, at stages when desmin mRNA levels are already high. The level of ClC‐1 mRNA is thus a sensitive and specific indicator of the maturation of skeletal muscle cells.
The effect of culture on the neuronotrophic activity of avian smooth muscle
Authors: Abrahamson I.K. , Murdoch S.Y. , Rush R.A.
Published: April 2003

The expansor secundariorum is a smooth muscle of the chicken wing which receives a dense noradrenergic innervation and contains high concentrations of trophic activity for sympathetic neurons. Expansor cells were dissociated in trypsin and grown to confluency in standard nutrient medium. Medium that had been conditioned by expansor cells contained trophic activity for chick sympathetic nerves which differed from the activity which is found within the muscle prior to culture, in that it was effective on a different neuronal subpopulation. Furthermore, unlike the factor(s) found in vivo, the trophic activity of the conditioned medium was not enhanced by NGF and could be partially inhibited by mouse NGF antibodies. Both the production of total trophic activity in the conditioned medium and the activity which differed from that in the muscle extract, increased rapidly and to the same extent between 24 and 48 h culture. Greater concentrations of trophic activity were present in medium conditioned by smooth muscle cells than by skin cells. The conditioned medium was able to support more neurons from 11 and 18 day incubated embryos than a saturating dose of NGF. Neither this effect nor the additive effect of conditioned medium with expansor muscle extract could be attributed to the presence of neurite promoting factors. We conclude that the cultured muscle produces neuronotrophic activity that is similar to the activity found in denervated but not innervated muscle.
Breeding rats on amino acid imbalanced diets for three consecutive generations affects the concentrations of putative amino acid transmitters in the developing brain
Authors: Thoemke Frank , Huether Gerald
Published: April 2003

Rats were bred for three consecutive generations (F1, F2, F3) on different amino acid enriched diets (tryptophan‐enriched, phenylalanine‐enriched, tyrosine‐enriched, valine‐isoleucineleucine‐enriched). The concentrations of the putative amino acid transmitters glycine, glutamate, aspartate, γ‐aminobutyric acid, and taurine were measured in the brain stem of the developing offsprings by thin layer micro‐chromatography of the dansylated amino acids. The concentrations of the investigated amino acid transmitters in the brain stem of the developing offspring of the amino acid imbalanced rats differed significantly from the values found in normal rats. The alterations from the normal developmental profiles were most pronounced in the rats bred on the valine‐isoleucine‐leucine‐enriched diet. Also the growth rate of the developing brain in each generation was affected by the different dietary amino acid supply. In the third generation at 20 days of age, with the exception of the rats bred on the tyrosineenriched diets, brain weights were generally decreased.
Rat brain glycosyltransferase activities during postnatal development
Authors: Broquet Pierre , Serres‐Guillaumond Mireille , Baubichon‐Cortay Héléne , Louisot Pierre
Published: April 2003

Enzymatic activity of seven glycoprotein and glycolipid glycosyltransferases was studied in microsomal fractions during postnatal development of rat brain from 3 to 42 days after birth. Specific enzymatic variations were detected for some glycosyltransferases, i.d. a maxima was shown at 7 days post partum for the glycoprotein galactosyltransferase and another one at 21 days for galactosylceramide biosynthesis, this latter correlated to myelin synthesis. However, a regular and important activity maxima was always detected for six of the enzymes studied (asialofetuin fucosyltransferase, ovomucoid galactosyltransferase, dolichyl phosphate mannose synthase, ceramide, galactosylceramide and glucosylceramide galactosyltransferases) at the period from 35 to 40 days post partum. As this period corresponds to immediate post‐puberty, an endocrinoneuronal control of the glycosyltransferases by sexual hormones is suggested.
Effect of maternal nicotine on the development of sites for [3H]nicotine binding in the fetal brain
Authors: Hagino N. , Lee J.W.
Published: April 2003

The sites for [3H]nicotine binding in fetal brains were examined after administration of nicotine into pregnant rats. Administration of unlabelled nicotine into the pregnant rats increased Bmax values for the sites for [3H]nicotine binding without affecting Kd values in the fetal brains. Treatment with this regimen, however, did not show any significant change in the sites for [3H]quinuclidinyl benzylate (QNB) binding. In addition, treatment with this regimen increased Bmax values of the sites for [3H]nicotine binding in the brains of pregnant rats. α‐Bungarotoxin had no effect on the sites for [3H]nicotine binding.

It is inferred, therefore, that a similar response is elicited by nicotine binding sites to administered nicotine in both the fetal and maternal brains. Furthermore, a possible effect of nicotine in pregnant rats may be the facilitation of the development of nicotine acetylcholine receptors in the fetal brain.
Development of binding sites for vasoactive intestinal polypeptide in mouse cerebral cortex and cultured cortical neurons
Authors: Staun‐Olsen P. , Fahrenkrug J. , Gammeltoft S. , Ottesen B. , Schousboe A.
Published: April 2003

Binding sites for vasoactive intestinal polypeptide (VIP) and the content of immunoreactive VIP were measured in the foetal and neonatal mouse brain cortex and primary cultures of foetal murine brain‐cortical neurons and astrocytes. The amount of cortical VIP binding sites and the concentration of immunoreactive VIP were low before birth, but increased postnatally reaching adult level at about 3 weeks of age. In cultures, a similar rise in neuronal binding sites occurred after 10 days, whereas the VIP concentration remained lower than in adult brain cortex. No binding sites or immunoreactive VIP could be detected in cultured astrocytes. The VIP binding sites were heterogeneous both in developing brain cortex and cultured neurons, and consisted of two classes of binding sites. The high affinity constants (2.5–2.9 nM) as well as low affinity constants (50–76 nM) were unchanged during the development, whereas the number of binding sites increased. In cultured neurons the binding constants were similar to those found in the adult mouse brain cortex. The peptide specificity for the VIP binding was similar in brain cortex and neuronal culture. In conclusion, the maturation of murine brain cortical neurons is accompanied by the development of synaptosomal VIP receptors in support of the neurotransmitter function of VIP.
The trophic effect of gaba on cerebellar granule cells is mediated by gaba‐receptors
Authors: Meier Eddi , Hansen Gert H. , Schousboe Arne
Published: April 2003

The effect of GABA, its agonist THIP (4,5,6,7‐tetrahydroisoxazolo[5,4‐c]pyridin‐3‐ol), and its antagonist bicuculline methobromide on the ultrastructure of cerebellar granule cells was studied. It was found that while the density of mitochondria, the ribosomes and smooth endoplasmic reticulum was unaffected by this treatment the density of neurotubules, rough endoplasmic reticulum, Golgi apparatus and coated as well as other vesicles was greatly enhanced by treatment of the cultured neurons with GABA (50 μM) or THIP (150 μM). The effects of GABA could be completely blocked by the simultaneous presence of bicuculline methobromide (150 μM) in the culture media. The findings strongly suggest that the trophic action of GABA is mediated by GABA receptors and not by an intracellular action of GABA.
Decreased density of synaptic formation in the frontal cortex of neonatal rats exposed to ethanol in utero
Authors: Inomata Kenichirou , Nasu Fumio , Tanaka Harumi
Published: April 2003

We examined the developing synaptic junctions in the rat frontal cortex in cases of fetal alcohol syndrome, the objective being to determine the synapse‐mental retardation relationship. On day 21 of gestation, the ultrastructural synaptic junction revealed no obvious differences between the ethanol‐exposed and control rats; however, the number of synapses in ethanol‐exposed rats was one third that of the controls. The possible relationship between synaptic density in the frontal cortex and mental development has to be considered.
Rates of protein synthesis in brain and other organs
Authors: Shahbazian F. M. , Jacobs Myron , Lajtha Abel
Published: April 2003

We previously found a decrease in protein synthesis in brain during development, which was much greater as measured in brain slices than in brain in vivo. In the present work such changes in brain were compared to those in other organs. With measurement of incorporation of flooding doses of [14C]valine into proteins of organs, the highest synthesis rate in the adult animal in vivo was found in liver (2.2%) followed by kidney (1.8%), spleen (1.6%), lung (1.0%), heart (0.7%), brain (0.6%) and muscle (0.5%). In immature animals the synthesis rate was highest in spleen (2.6%) followed by liver (2.4%), kidney (1.7%), lung (1.6%), brain (1.5%), heart (1.1%), and muscle (0.9%). Protein synthesis in slices from each tissue proceeded at lower rates than in vivo, especially in adults. The tissue affected the most by the preparation of the slices was muscle.
Influence of basic fibroblast growth factor on carbonic anhydrase expression by rat glial cells in primary culture
Authors: Delaunoy J. P. , Langui D. , Ghandour S. , Labourdette G. , Sensenbrenner M.
Published: April 2003

Modifications of the morphology, the proliferation and the synthesis of carbonic anhydrase of glial cells in primary cultures maintained in defined medium have been investigated under the action of basic fibroblast growth factor. Cultures contained essentially three cell types: astrocytes which expressed glial fibrillary acidic protein, oligodendrocytes which were characterized by the presence of carbonic anhydrase and precursor cells in which these two proteins were detected by immunocytochemistry. In the presence of basic fibroblast growth factor astrocytes and oligodendrocytes underwent morphological changes, characterized by a fibrous aspect; astroglial cells acquired essentially several long processes and oligodendroglial cells formed generally two long processes. The factor increased the proliferation of these two cell types. The quantity of carbonic anhydrase per oligodendrocyte was enhanced in treated cultures. The double‐stained precursor cells were present between days 7 and 11 of culture in defined medium, while in the presence of fibroblast growth factor these cells were more numerous and were still present after 14 days. The basic fibroblast growth factor stimulated the proliferation of these young glial cells and modified their morphology. But the differentiation of precursor cells towards one glial cell type appeared to be delayed.
Synaptophysin in the developing cochlea
Authors: Gil‐Loyzaga Pablo , Pujol Rémy
Published: April 2003

The immunoreactivity to SY38 (anti‐synaptophysin antibody) was investigated in rat and guinea‐pig cochleas during development. In rat pups SY38 reactivity first appeared in the inner spiral bundle (below inner hair cells) at postnatal day 3. Later on (days 10 and 15) the basal pole of outer hair cells (OHCs) was also reactive. In fetal guinea‐pigs, the inner spiral bundle was reactive on day 45 of gestation, while the reactivity occurred below OHCs on day 62 of gestation. A preliminary electron microscopic finding (from a guinea‐pig 62 days of gestation) indicated that SY38 immunoreactivity is localized within varicosities of efferent (olivo‐cochlear) endings. Synaptophysin is thus present in the cochlea at the level where the two efferent systems terminate. Moreover, the occurrence of SY38 immunoreactivity, first at the ISB then at the OHC levels, is in accordance with the observation that the maturation of lateral efferents preceeds that of medial efferents.
The effects of intrauterine growth retardation on synaptogenesis and mitochondrial formation in the cerebral and cerebellar cortices of fetal sheep
Authors: Bisignano Maria , Rees Sandra
Published: April 2003

In an experimental model of growth retardation which involves the reduction of placental mass in sheep, we have investigated the effects of intrauterine deprivation on synaptogenesis, synaptic ultrastructure and mitochondrial formation in the cerebral and cerebellar cortices of fetal sheep (140 days gestation). In the growth‐retarded fetus, the numerical density of synapses in layer I of the visual cortex was reduced by 17% (P<0.05) compared with controls but there was no detectable difference between the two groups in the density of parallel fibre‐Purkinje cell synapses in the molecular layer of the cerebellum. The length and curvature of the postsynaptic density at synapses in both regions were not affected in growth retardation but the synaptic cleft was 13% wider in the cerebellum (P<0.05) in growth retardation compared with controls. The number of mitochondrial profiles per unit area of neuropil in the visual cortex was increased by 20% (P<0.01) in growth retardation and the electron density of the inner matrix increased but the average profile area was not affected. These findings show that intrauterine growth retardation affects some aspects of synaptic development in the cerebellum and the visual cortex. The increase in the number of mitochondrial profiles in the visual cortex of growthretarded fetuses might be an attempt by the cortical neurons to compensate for the reduced efficiency of aerobic metabolism in individual mitochondria.
The development and maturation of adrenal medullary chromaffin cells of the rat in vivo: A descriptive and quantitative study
Authors: Coupland R. E. , Tomlinson A.
Published: April 2003

A descriptive account and morphometric study of the adrenal medulla and adrenal chromaffin cells of Wistar rats aged from birth to 22 months is presented. Distinct adrenaline and noradrenalinestoring types of chromaffin cells are first identified in 4‐day‐old animals, prior to that time individual cells contain both adrenaline‐ and noradrenaline‐storing granules. Primitive sympathetic cells and phaeochromoblasts occur up to 2 days postnatally. Mitotic figures occur in chromaffin cells of a maturity and appearance appropriate to age and most frequently in adrenaline‐storing cells. The adrenal medulla continues to increase in volume throughout the period and chromaffin cells increase in number and in some cases volume. There is a corresponding increase in neuronal elements. In 22‐month‐old rats individual cells or groups of chromaffin cells show evidence of hypertrophy and changes in cytoplasmic organelles, in particular lysosomes, rough endoplasmic reticulum and storage granules and vesicles. Some hypertrophied chromaffin cells contain a heterogeneous population of granules suggesting a degree of functional plasticity in some cells in aged rats.