bluuebunny/crossref_metadata_2025 huggingface dataset:
Duodenal ulcer prevalence: research into the nature of possible protective dietary lipids
Authors: Paul Jayaraj A. , Tovey Frank I. , Hobsley Michael
Published: April 2003

The varying geographical prevalence of duodenal ulceration has suggested a relationship to staple diet. Previous experiments on animal peptic ulcer models showed that certain foods, particularly the lipid fraction, are ulceroprotective. This paper reports experiments on animal models further to investigate the nature of the protective substances in the most active lipid, that of horse gram. The free fatty acids and triglycerides, sterols, sterol esters and phospholipids from horse gram were extracted and tested for protective activity on rat peptic ulcer models: the pyloric ligation model which is chronic, involving 14 days pre‐feeding, and two acute models using ethanol or cysteamine to induce ulceration. The results showed that sterol esters, but not sterols, were protective in the pyloric ligation model. Sterols were protective in the acute models using ethanol‐induced and cysteamine‐induced ulceration. Phospholipids were protective in both types of model. The free fatty acids and triglycerides gave no protection using the pyloric ligation model.

The presence of sterols, sterol esters and phospholipids in the lipid fraction of foods in staple diets may account for the low prevalence of duodenal ulcer in certain geographical areas, despite a uniformly high prevalence of Helicobacter pylori infection. Copyright © 2003 John Wiley & Sons, Ltd.
Cold denaturation of yeast phosphoglycerate kinase: which domain is more stable?
Authors: Gast Klaus , Damaschun Gregor , Desmadril Michel , Minard Philippe , Müller-Frohne Marlies , Pfeil Wolfgang , Zirwer Dietrich
Published: April 2003

Under destabilising conditions both heat and cold denaturation of yeast phosphoglycerate kinase (PGK) can be observed. According to previous interpretation of experimental data and theoretical calculations, the C‐terminal domain should be more stable than the N‐terminal domain at all temperatures. We report on thermal unfolding experiments with PGK and its isolated domains, which give rise to a revision of this view. While the C‐terminal domain is indeed the more stable one on heating, it reveals lower stability in the cold. These findings are of importance, because PGK has been frequently used as a model for protein folding and mutual domain interactions.
Hypoxia and platelet‐derived growth factor‐BB synergistically upregulate the expression of vascular endothelial growth factor in vascular smooth muscle cells
Authors: Stavri George T. , Hong Ying , Zachary Ian C. , Breier Georg , Baskerville Paul A. , Ylä-Herttuala Seppo , Risau Werner , Martin John F. , Erusalimsky Jorge D.
Published: April 2003

Vascular endothelial growth factor (VEGF) mRNA expression was analysed in rabbit vascular smooth muscle cells following exposure to hypoxia and platelet‐derived growth factor‐BB (PDGF‐BB). Hypoxia potently upregulated VEGF mRNA steady‐state levels in a time‐ and concentration‐dependent manner reaching a maximum level (∼30‐fold increase) after 12–24 h at 0% 02. In contrast, PDGF‐BB caused a modest increase in VEGF expression. However, the combination of PDGF‐BB and a threshold hypoxic stimulus (2.5% O2 for 4 h) had a marked synergistic effect. Synergy between hypoxia and PDGF‐BB was selective for VEGF expression as hypoxia had no effect on the PDGF‐induced upregulation of the proto‐oncogene c‐myc. These results raise the possibility that hypoxia and PDGF‐BB may act in concert to induce VEGF expression in the arterial wall during the development of atherosclerosis.
Sodium butyrate inhibits expression of urokinase and its receptor mRNAs at both transcription and post‐transcription levels in colon cancer cells
Authors: Dang Jinjun , Wang Yao , Doe William F.
Published: April 2003

The effects of butyrate on the modulation of urokinase plasminogen activator (uPA) and its receptor (uPAR) mRNAs were studied. While both mRNA levels were increased after stimulation by tumor necrosis factor alpha (TNFα), phorbol ester (PMA) and cycloheximide, they were inhibited by butyrate at 2.5 to 25 mM. Nuclear run‐on transcription assays indicated that uPA mRNA was modulated by butyrate at the transcriptional level but the uPAR gene was regulated at both transcriptional and post‐transcriptional levels in the presence or absence of TNFα. In the presence of PMA, however, butyrate acts at the post‐transcriptional level on both genes.
‘Brain‐type’ N‐glycosylation of asialo‐transferrin from human cerebrospinal fluid
Authors: Hoffmann Andrea , Nimtz Manfred , Getzlaff Rita , Conradt Harald S.
Published: April 2003

Asiolo‐transferrin from human cerebrospinal fluid was purified to homogeneity. Investigation of the structural characteristics of its oligosaccharides support our hypothesis of ‘brain‐type’ glycosylation of intrathecally synthesized cerebrospinal fluid proteins. For carbohydrate structural analysis, high‐pH anion‐exchange chromatography, methylation analysis, liquid secondary ion‐ and matrix‐assisted laser desorption/ ionization mass spectrometry of the permethylated derivatives were used. The major structure turned out to be a complex‐type agalacto‐diantennary oligosaccharide with bisecting N‐acetylglucosamine and proximal fucose. Analysis of a second transferrin preparation containing both asialo‐ and sialo‐transferrin revealed another major glycan species derived from the sialylated transferrin variant which is galactosylated and lacks bisecting N‐acetylglucosamine and fucose.
The use of mass spectrometry to examine the formation and hydrolysis of the phosphorylated form of phosphoglycerate mutase
Authors: Nairn Jacqueline , Krell Tino , Coggins John R. , Pitt Andrew R. , Fothergill-Gilmore Linda A. , Walter Rebecca , Price Nicholas C.
Published: April 2003

Electrospray mass spectrometry has been used to study the formation and hydrolysis of the phosphorylated forms of two phosphoglycerate mutases. The half‐life of the enzyme from Saccharomyces cerevisiae was 35 min at 20°C in 10 mM ammonium bicarbonate, pH 8.0. Addition of 1 mM 2‐phosphoglycollate reduced this value by at least 100‐fold. The phosphorylated form of the enzyme from Schizosaccharomyces pombe was much less stable with a half‐life of less than 1 min. The results are discussed in terms of the kinetic properties of the enzymes. Mass spectrometry would appear to be a powerful method to study the formation and breakdown of phosphorylated proteins, processes which are of widespread significance in regulatory mechanisms.
Sequence and evolutionary conservation of the murine Gbx‐2 homeobox gene
Authors: Chapman Gavin , Rathjen Peter D.
Published: April 2003

The homeobox gene family is divided into classes based on similarity of sequence across the homeodomain. Representative members of discrete classes are often conserved widely throughout evolution and this can extend to their genomic organisation and biological function. In this paper we report the first complete cDNA sequence of a member of the GBX class of homeobox genes, the murine gene Gbx‐2. Sequence comparisons indicate that this homeodomain class is highly conserved within vertebrates. The homeodomain differs at only three positions out of 60 and these can be used to subdivide the GBX class homeodomains into 2 sub‐classes.
Down‐regulation but not phosphorylation of stathmin is associated with induction of HL60 cell growth arrest and differentiation by physiological agents
Authors: Johnson W.Eustace B. , Jones Neil A. , Rowlands David C. , Williams Ann , Guest Simon S. , Brown Geoffrey
Published: April 2003

Stathmin is a cytosolic phosphoprotein that has an important but, as yet, undefined role in cell proliferation and differentiation. Induction of growth arrest and differentiation of HL60 cells to monocytes by phorbol 12‐myristate 13‐acetate is associated with rapid phosphorylation of the protein. Stathmin phosphorylation was not seen when HL60 cells were induced to differentiate to monocytes, by 1α,25‐dihydroxyvitamin D3, and to neutrophils, by all‐trans retinoic acid and granulocyte colony stimulating factor. In all the above instances, stathmin expression was down‐regulated. Thus, increased stathmin phosphorylation is not required for cell growth arrest or differentiation or down‐regulation of stathmin expression.
Involvement of phosphatidylinositol 3‐kinase in the activation of extracellular signal‐regulated kinase by PDGF in hepatic stellate cells
Authors: Marra Fabio , Pinzani Massimo , DeFranco Raffaella , Laffi Giacomo , Gentilini Paolo
Published: April 2003

Phosphatidylinositol 3‐kinase (PI 3‐K) is a lipid and protein kinase which associates with the activated platelet‐derived growth factor (PDGF) receptor and other tyrosine kinases. We studied the effects of wortmannin, a selective inhibitor of PI 3‐K, on the activation of extracellular‐signal regulated kinase (ERK) by PDGF in cultured hepatic stellate cells, mesenchymal cells responsible for extracellular matrix synthesis within the liver. Incubation with 100 nM wortmannin, a dose which almost completely blocks PI 3‐K, resulted in 50% reduction of ERK activity. Direct inhibition of ERK by wortmannin could not be considered responsible for this effect, since wortmannin did not inhibit ERK activity in vitro. Rather, inhibition of PI 3‐K acts on the kinase cascade that leads to ERK activation, since PDGF‐dependent phosphorylation of ERK was found to be reduced after incubation with wortmannin. Wortmannin also inhibited the increase in c‐fos mRNA induced by PDGF, which is dependent on ERK activation. The results of this study show that in hepatic stellate cells PI 3‐K is involved in ERK activation, although it is not necessary. These data indicate cross‐talk between PI 3‐K and the Ras/ERK pathway in PDGF‐stimulated cells.
Functional expression of an alpha anti‐insect scorpion neurotoxin in insect cells and lepidopterous larvae
Authors: Chejanovsky Nor , Zilberberg Noam , Rivkin Hadasah , Zlotkin Eliahu , Gurevitz Michael
Published: April 2003

The Leiurus quinquestriatus hebraeus alpha anti‐insect toxin (LqhαIT) cDNA was engineered into the Autographa californica Nuclear Polyhedrosis Virus (AcNPV) genome. Insect cells infected with the recombinant virus secreted a functional LqhαIT polypeptide. Spodoptera littoralis and Heliothis armigera larvae injected with recombinant budded virus, showed typical intoxication symptoms. This recombinant virus showed enhanced insecticidal potency against H. armigera larvae compared with wild type AcNPV. The present expression system will facilitate: (1) the future elucidation of structural elements involved in its prominent anti‐insect toxicity; and (2) the future design of genetically modified alpha toxins with improved anti‐insect selectivity.
Evidence for direct involvement of the sarcoplasmic reticulum Ca2+‐ATPase in a passive monovalent cation (K+/Na+) exchange
Authors: de Jesus Florence , Cuillel Martine , Dupont Yves
Published: April 2003

A specific inhibitor of SERCA‐pumps, thapsigargin (TG) was used to demonstrate the direct involvement of the SR Ca2+‐ATPase in passive K+/Na+ exchange. The K+‐potential variations across vesicle membranes were measured in the absence of ATP with a fluorescent probe: 3,3′‐dipropylthiodicarbocyanine iodide. Addition of EGTA dissipates the K+‐potential whereas the presence of TG abolishes this effect. Our data prove that the Ca2+‐ATPase translocates monovalent cations at a rate similar to the E2→E1 conformational change.
cDNA sequences of three sheep myeloid cathelicidins
Authors: Bagella Luigi , Scocchi Marco , Zanetti Margherita
Published: April 2003

Several myeloid antimicrobial peptide precursors have been shown to consist of a N‐terminal proregion similar to a protein named cathelin and a structurally varied C‐terminal antimicrobial domain. Proteins with these features have been named cathelicidins. In this paper we report the cDNA sequences of three ovine cathelicidins of 155, 160 and 190 residues, respectively, with cationic C‐terminal sequences corresponding to putative antimicrobial domains. These are structurally varied and include a Cys‐rich sequence of 12 residues, which is similar to the bovine antimicrobial cyclic dodecapeptide, a novel 29 residue sequence named SMAP‐29 with a possible α‐helical conformation, and a 60 residue sequence named Bac7.5, which appears to be a new member of the Pro‐ and Arg‐rich group of mammalian antimicrobial peptides.
Post X‐ray crystallographic studies of chymosin: the existence of two structural forms and the regulation of activity by the interaction with the histidine‐proline cluster of κ‐casein
Authors: Gustchina Elena , Rumsh Lev , Ginodman Lev , Majer Pavel , Andreeva Natalia
Published: April 2003

Calf chymosin molecules exist in the two alternative structural forms: the first one has S1 and S3 binding pockets occluded by its own Tyr77 residue (the self‐inhibited form); the second has these pockets free for a substrate binding (the active form). The preliminary incubation of the enzyme with a pentapeptide corresponding to the histidine‐proline cluster of the specific substrate κ‐casein results in a 200‐fold increase of the hydrolysis rate for the enzyme ‘slow substrate’. The result suggests that the cluster is an allosteric effector that promotes the conversion of the enzyme into the active form. These data provide the experimental ground for the explanation of chymosin specificity towards κ‐casein.
3D solution structure of copper and silver‐substituted yeast metallothioneins
Authors: Peterson Cynthia W. , Narula Surinder S. , Armitage Ian M.
Published: April 2003

3D solution structural calculations for yeast silver(I)‐substituted metallothionein (MT) and native copper(I) MT were completed using experimentally determined NOE and dihedral angle constraints, in conjunction with experimentally derived metal‐to‐Cys connectivities for AgMT which were assumed identical for CuMT. For the first 40 residues in both structures, the polypeptide backbone wraps around the metal cluster in two large parallel loops separated by a deep cleft containing the metal cluster. Minor differences between the two structures include differences in hydrogen bonds and the orientation of the N‐terminus with the overall protein volume conserved to within 6.5%.
The role of ETB receptors in normotensive and hypertensive rats as revealed by the non‐peptide selective ETB receptor antagonist Ro 46‐8443
Authors: Clozel Martine , Breu Volker
Published: April 2003

We used Ro 46‐8443, non‐peptidic antagonist selective of endothelin ETB receptors, to study the role of ETB receptors in rat hypertension models. In normotensive rats, Ro 46‐8443 decreased blood pressure, but in SHR and DOCA rats, it induced a pressor effect, due to blockade of ETB‐mediated release of nitric oxide since L‐NAME prevented it. In rats rendered hypertensive by chronic L‐NAME, Ro 46‐8443 did not induce a pressor but depressor effect. Thus, in DOCA rats and SHR, Ro 46‐8443 reveals a predominant influence of endothelial ‘vasorelaxant’ ETB receptors, while in normotensive rats the prevailing role of ETB receptors seems to be in mediating a vasoconstrictor tone.
Differential effects of Th1 and Th2 derived cytokines on NGF synthesis by mouse astrocytes
Authors: Brodie Chaya
Published: April 2003

During the course of brain injury and inflammation there is an increased secretion of neurotrophic substances by astrocytes. We have examined the effect of the Th2‐derived cytokine IL‐10 and the Th1‐derived cytokines Il‐2 and IFN‐γ on the secretion of NGF by mouse astrocytes. IL‐10 induced a dose‐dependent increase in NGF secretion which was blocked by anti‐IL‐10 antibody. In contrast, the Th1‐derived cytokines IFN‐γ and IL‐2 did not induce NGF synthesis. Moreover, INF‐γ completely inhibited the increase in NGF secretion induced by IL‐10 whereas it had no effect on the induction of NGF by TNF‐α. These results indicate that IL‐10 similarly to other Th2‐derived cytokines may provide a neurotrophic support to injured neurons via the induction of NGF synthesis, whereas the Th1‐derived cytokine IFN‐γ antagonizes this effect.
SV40 T1‐mRNA trans‐splicing and translation requires that the in vitro synthesized cRNA is capped before microinjection
Authors: Graessmann M. , Eul J. , Berg B. , Zimmermann C. , Graessmann A.
Published: April 2003

The purpose of this investigation was to study the effect on cap structure for trans‐splicing in mammalian cells. The early SV40 Bst/Bam pre‐mRNA (cRNA) was synthesized in vitro in both capped (cap‐Bst/Bam‐cRNA) and non‐capped (Bst/Bam‐cRNA) versions and microinjected into the nuclei of TC7 cells. Trans‐splicing was monitored by immunofluorescence staining (T1‐antigen) and by RT‐PCR analysis. Cap‐Bst/Bam‐cRNA was trans‐spliced with high efficiency, but not the Bst/Bam‐cRNA molecules. Northern blot analysis revealed that both the capped and uncapped cRNA molecules had similar stability in the microinjected cells. The coinjected m7G(5′)ppp(5′)G cap analog did not inhibit the trans‐splicing reaction in vivo and did not prevent nuclear export of the mRNA.
Determination of the disulfide array of the first inducible antifungal peptide from insects: drosomycin from Drosophila melanogaster
Authors: Michaut Lydia , Fehlbaum Pascale , Moniatte Marc , Van Dorsselaer Alain , Reichhart Jean-Marc , Bulet Philippe
Published: April 2003

Drosomycin is a 44‐residue antifungal peptide with four intramolecular disulfide bridges which have been isolated from immune‐challenged Drosophila. To produce adequate amounts of this peptide for 3D‐structure analysis, studies on the mode of action and activity spectrum, we expressed a synthetic cDNA in Saccharomyces cerevisiae. For this purpose, we used the mating factor α gene and concomitantly overexpressed the KEX2 gene to increase the yield of fully processed drosomycin. Using a combination of Edman degradation and mass spectrometry, we show that drosomycin shares the same array of intramolecular disulfide bridges than plant defensins, in addition to their sequence similarities.
Structure and expression of two highly related genes encoding SCM‐1/human lymphotactin
Authors: Yoshida Tetsuya , Imai Toshio , Takagi Shin , Nishimura Miyuki , Ishikawa Izumi , Yaoi Takeshi , Yoshie Osamu
Published: April 2003

SCM‐1/lymphotactin is a chemokine‐like molecule produced selectively, if not exclusively, by activated CD8+ T cells. Here we report that there are two highly homologous SCM‐1 genes, which we designate as SCM‐1α and SCM‐1β. Both genes have three exons and two introns. The 1st intron of SCM‐1α contains a pseudogene of the ribosomal large subunit L7a. In SCM‐1β, a 1.5‐kb region including about a quarter of the L7a pseudogene is deleted from the 1st intron. Otherwise, the two genes are highly homologous including the 5′ and 3′ flanking regions. Both genes were mapped to human chromosome 1q23. The two genes were similarly induced in peripheral blood mononuclear cells by mitogenic stimulation. Primer extension and RNase protection revealed several transcription initiation sites. The biological activities of SCM‐1α and SCM‐1β, which have two amino acid differences at positions 7 and 8 in the mature proteins, remain to be compared.
Role of ETB receptors in local clearance of endothelin‐1 in rat heart: studies with the antagonists PD 155080 and BQ‐788
Authors: Brunner Friedrich , Doherty Annette M.
Published: April 2003

The effects of two endothelin (ET) receptor antagonists, PD 155080 (ETA selective) and BQ‐788 (ETB selective), on cardiac function and ET‐1 release were studied in isolated rat hearts. In normoxic hearts, infusion of PD 155080 (50 nM‐5 μM) reduced coronary resistance, but had no effect on ET‐1 release. Low concentrations of BQ‐788 (2 and 20 nM) had no effect on coronary resistance; high concentrations (0.2 and 2 μM) increased it ∼ 2‐fold; all concentrations increased ET‐1 release (up to 24‐fold). Similar results were obtained in reperfused hearts. Although concentrations of ET‐1 were higher in interstitial fluid than coronary effluent, levels never exceeded the low pg/ml range. These results indicate that (1) ETA receptors mediate coronary constriction, whereas ETB receptors bind and sequester ET‐1, and (2) ET‐1 displaced by ETB antagonist accesses ETA receptors resulting in coronary constriction.
Direct excision of 50 kb pair DNA fragments from megabase‐sized fragments produced during apoptotic cleavage of genomic DNA
Authors: Sestili Piero , Cattabeni Flaminio , Cantoni Orazio
Published: April 2003

The DNA of U937 cells exposed to two different apoptotic stimuli, namely the cocktail H2O2/3‐aminobenzamide (3AB) and etoposide, was analyzed using field inversion gel electrophoresis (FIGE) as well as programmable, autonomously controlled electrode electrophoresis (PACE). The results obtained indicate that FIGE is not appropriate for sizing apoptotic DNA fragments. PACE appears to be more accurate and reliable and the results obtained with this technique strongly suggest that the 50 kb DNA fragments are directly excised from Mb‐sized DNA fragments without the intermediate cleavage of 200–300 kb products.
Infrastructure and flexible manufacturing technology: Theory development
Authors: Maffei Mary Jo , Meredith Jack
Published: April 2003

Many firms have installed flexible manufacturing technologies but have not achieved the expected benefits. While considerable research has been conducted on the difficulty of implementing advanced forms of technology, this study investigated the operational infrastructure required to benefit from the routine use of such technology. Six in‐depth case studies were conducted to ascertain the performance impact of three areas of the operational infrastructure: the operator's role, the production planning systems and the integration of technology with the organization. Performance was evaluated in terms of quality, marketing, responsiveness, cost/productivity, inventory and on‐time delivery. Based on the insights from the case studies, eleven propositions and three conceptual models identifying the impact of specific infrastructure elements on the benefits attained from the use of flexible manufacturing technology were developed.
Scheduling outpatient appointments in a dynamic environment
Authors: Klassen Kenneth J. , Rohleder Thomas R.
Published: April 2003

The primary issue addressed in this research is how to schedule clients as they call for appointments, without knowing which “types” of clients will call at a later time. The main goal is to compare various scheduling rules in order to minimize the waiting time of the clients as well as the idle time of the service provider. Interviews with receptionists verified that they have knowledge regarding differences between clients' service time characteristics. This information is used both to differentiate between clients and to develop various scheduling rules for those clients. A simulation model of a dynamic medical outpatient environment is developed based on insight gained from the interviews and from prior research.

Two decision variables are analyzed (“scheduling rule” and “position of appointment slots left unscheduled for potential urgent calls”) while two environmental factors are varied (“expected mean of the clients' service time”, and “expected percentage of clients with low service time standard deviation compared to those with high service time standard deviation”). This resulted in 30 combinations of decision variables, each tested within 15 combinations of environmental factors. By using multiple performance measures, it is possible to improve considerably on some of the “best” rules found in the current literature. The “best” decisions depend on the goals of the particular clinic as well as the environment it encounters. However, good or best results can be obtained in all cases if clients with large service time standard deviations are scheduled toward the end of the appointment session. The best positioning of slots left open for urgent clients is less clear cut, but options are identified for each of a number of possible clinic goals.
Effects of gangliosides on the in vitro development of neuroblastoma cells: An ultrastructural study
Authors: Spoerri P. E.
Published: April 2003

The role of gangliosides in neuronal differentiation was studied by adding a mixture of bovine brain gangliosides to mouse neuroblastoma cells which were induced to differentiate through the application of γ‐aminobutyric acid (GABA) or sodium bromide (NaBr). GABA or NaBr was applied to 5‐day‐old cultures at concentrations ranging from 10−4 to 10−5M. The cells were exposed to these substances over short periods of time (2 days). A mixture of bovine brain gangliosides was added to the 7‐day‐old cultures for 24–28 h. Electron microscopy revealed that ganglioside‐induced morphological differentiation was accompanied by a significant number of mature synapse‐like contacts. The GM1 gangliosides fraction apparently plays an important role in the formation of mature synapses, since none were observed when the GM1 was removed from the ganglioside mixture.
Fine structure of the human fetal cervical ganglia
Authors: Helén Pauli , Hervonen Antti
Published: April 2003

Cervical sympathetic ganglia from nine human fetuses in the second trimester were studied by light‐, fluorescence‐ and electronmicroscopy. Within ganglia granule‐containing cells, corresponding to the small intensely fluorescent (SIF) cells, were sparsely distributed along capillaries. Satellite cells were interspersed among neuronal cell types. All stages of the developing sympathetic ganglion cells were present. Primitive sympathetic ganglion cells (PSC) had dark nuclei and scanty cytoplasm in which the rough endoplasmic reticulum (RER) was not organized. These cells often contacted each other vs the more mature pattern of satellite cell support. Neuroblasts had more voluminous cytoplasm, RER was more apparent than in the PSCs and dense‐cored vesicles and mitochondria were more frequently seen. Their diameter was between 5 and 20 μm. The most mature neuronal cell type, the young sympathetic ganglion cell, was often covered by satellite cells, but synaptic contacts often appeared on the somata. Maturity of the cells was underscored by an abundant RER and ribosomes organized as Nissl bodies. Indeed all the organelles typical of an adult ganglion cell were present and fully developed, although in smaller amounts. However, the diameter (20–30 μm) of the cells was smaller than in adult ganglia. All ganglia examined possessed mature axodendritic and axosomatic synapses. Large dense‐cored vesicles were found in some neuroblasts and in young sympathetic ganglion cells. However, neither cytoplasmic nor synaptic small dense‐cored vesicles were seen. These morphological results correlate with pharmacological and immunohistochemical data on human fetal tissue which show that both cholinergic and adrenergic receptors, catecholamine‐synthesizing enzymes and enkephalin are developed by the end of the first trimester.
Long‐term reduction in spontaneous alternations after early exposure to phenobarbital
Authors: Pick Chaim G. , Yanai Joseph
Published: April 2003

Spontaneous alternation behavior is related to the integrity of the hippocampus. Our earlier studies demonstrated hippocampal deficits after early phenobarbital (PhB) exposure. In the present study, we examined spontaneous alternation of mice who had been exposed to PhB prenatally or neonatally. Prenatal PhB was administered transplacentally: pregnant females were fed 3 g PhB/kg milled food on gestation days 9–18. Neonates were treated directly with daily injections of 50 mg PhB/kg on postnatal days 2–22. The animals were tested for spontaneous alternation in a T maze at the ages of 22, 28, 35 and 42 days. The test was conducted at each age for two consecutive days. A maximum of four alternations were allowed on the first day, and one alternation on the second day. Animals treated neonatally had reductions in alternation from the control group for every age group. Looking at the mean of the four trials on the first day there was a reduction of 35% at age 22 (P < 0.001), 8% at age 28, 21% at age 35 (P < 0.05) and 36% at age 42 (P < 0.02). On the second day the respective reductions were 32, 19, 24 and 36% (P < 0.05). The differences in alternation between animals treated with PhB prenatally and the control group were too small to reach statistical significance. Subsequently a more sensitive test, delayed spontaneous alternation (30 s), was applied to an additional group of animals at age 42 which had been prenatally exposed to PhB: 31% reduction from the control group was found on day 1 (P < 0.001), and 34% on day 2 (P < 0.02). The greater differences after neonatal as opposed to prenatal administration could be related to the more extensive hippocampal damage that was found in adults after neonatal treatment.
Neurogenesis in the olfactory tubercle and islands of Calleja in the rat
Authors: Bayer Shirley A.
Published: April 2003

Neurogenesis in the rat olfactory tubercle and islands of Calleja was examined with [3H]thymidine autoradiography. Animals in the prenatal groups were the offspring of pregnant females given an injection of [3H]thymidine on two consecutive gestational days. Ten groups of embryos (E) were exposed to [3H]thymidine on E12–E13, E13–E14 4 E21–E22, respectively. Three groups of postnatal animals (P) were given four consecutive injections of [3H]thymidine on P0–P3, P2–P5, and P4–P7, respectively. On P60, the percentage of labeled cells and the proportion of cells originating during either 24 or 48 h periods were quantified at several anatomical levels. Three populations of neurons were studied: (1) large cells in layer III, (2) small to medium‐sized cells in layers II and III, and in the striatal bridges, (3) granule cells in the islands of Calleja. Neurogenesis is sequential between these three populations with No. 1 oldest and No. 3 youngest. The large neurons in layer III originate mainly between E13 and E16 in a strong lateral‐to‐medial gradient. Neurons in population No. 2 are generated between E15 and E20, also in a lateral‐to‐medial gradient; neurogenesis is simultaneous along the superficialdeep plane. Granule cells in the smaller islands of Calleja are generated between E17 and E22 in combined lateral‐to‐medial and superficial‐to‐deep gradients. Neurons in the large island of Calleja are generated mainly between E19 and E22 in a strong rostral‐to‐caudal gradient. Neurogenesis is reduced to < 10% in both populations No. 2 and No. 3, occurring mainly between P0 and P4. The neurogenetic patterns in populations No. 2 and No. 3 are similar to those in the striatum, while neurogenesis in population No. 1 fits into the pattern of the globus pallidus and substantia innominata. These developmental patterns indicate that the olfactory tubercle is a mixed striato‐pallidal system rather than an olfactory cortical area. The lateral‐to‐medial neurogenetic gradient shown in each neuronal population in the olfactory tubercle correlates with both differential anatomical projections and differential neurochemical characteristics along the lateral‐medial plane.
Effects of prenatal alcohol exposure on neural cells in mice
Authors: Blakley Patricia M. , Fedoroff Sergey
Published: April 2003

Pregnant DBA/1J mice were treated orally with 1.0 or 2.0 g/kg ethanol from days 11–17 of gestation to determine whether ethanol can perturb normal brain development. On gestational day 18 the fetuses were removed and fetal growth parameters were determined. The cerebrums from one group of fetuses were subsequently analyzed for cell number and protein content. The remaining cerebrums were assayed for their ability to grow in an in vitro cell culture system. Prenatal ethanol exposure decreased fetal body and brain weights and crown‐rump length. The brain was particularly affected as indicated by a decreased brain: body wt ratio. The percentage of affected and marginally affected fetuses increased in a dose‐dependent manner. While the number of cells/brain was unaffected, the number of cells/g cerebrum and the number of cells/mg cerebral protein was increased. Prenatal ethanol exposure decreased the ability of cerebral cells to grow in culture as demonstrated by the reduced plating efficiency and reduced colony size.

The data from the present study suggest that ethanol induces a two‐fold effect on mouse brain development. First, since the total number of cells/brain was not appreciably affected by prenatal ethanol treatment, it is possible that the reduction in brain size is due to a decreased amount of neuropil. This putative effect on the neuropil was manifested in vitro by decreased colony area. Second, the decreased plating efficiency of cells from brains of affected fetuses suggests that these cells are not functionally normal. These effects may be important in the pathogenesis of central nervous system anomalies associated with the Fetal Alcohol Syndrome.
Postnatal development of glutamate metabolizing enzymes in hippocampus from mice
Authors: Kvamme E. , Svenneby G. , Torgner I. AA. , Drejer J. , Schousboe A.
Published: April 2003

The specific activity profiles of the glutamate synthesizing enzymes, phosphate activated glutaminase (EC 3.5.1.2), aspartate aminotransferase (EC 2.6.1.1), glutamate dehydrogenase (EC 1.4.1.2) and ornithine aminotransferase (EC 2.6.1.13) have been followed postnatally for 28 days in mouse hippocampus and compared to corresponding profiles in cerebellum and cerebral cortex (cf. refs 10 and 18). Phosphate activated glutaminase and glutamate dehydrogenase showed activity patterns similar to those found for cerebellum and glutamatergic granula cells cultured from cerebellum, whereas the aspartate aminotransferase activity pattern was found to be more similar to that previously observed for cerebral cortex as well as cultured cerebral interneurons which are likely to be GABAergic. The specific activity of ornithine aminotransferase was essentially unaltered during postnatal development, which is similar to what has been found for cerebellum and cerebral cortex.
Nerve growth factor in medium conditioned by embryonic chicken heart cells
Authors: Norrgren Gunilla , Ebendal Ted
Published: April 2003

The present report demonstrates that embryonic chicken heart cells in culture release different nerve growth promoting factors to their culture medium, one which is biologically and immunologically similar to mouse gland βNGF. Serum‐free heart cell conditioned medium thus promoted neurite outgrowth from sympathetic and ciliary ganglia and supported survival of dissociated ciliary neurons. The addition of affinity purified antibodies against mouse βNGF does substantially but not completely inhibit the fibre outgrowth from sympathetic ganglia, but does not to any extent diminish the effects on the parasympathetic neurons. The chicken NGF recovered from polyacrylamide gels after electrophorcsis greatly enhanced sympathetic fibre outgrowth, an activity completely suppressive by anti‐βNGF antibodies. We conclude that a chicken NGF is being produced by the embryonic heart cells in culture and that this factor may be produced also in the embryo to fulfill a role in heart innervation.
Embryonic development of mevalonate metabolism by sterol and nonsterol pathways in chick brain and liver
Authors: Marco C. , González‐Pacanowska D. , Garcia‐Peregrin E.
Published: April 2003

The embryonic development of the sterol and nonsterol mevalonate metabolism has been investigated in chick brain and liver. The shunt pathway of mevalonate was negligible in both tissues throughout 10–21 days of embryo development. Mevalonate incorporation into nonsaponifiable lipids was higher in liver than in brain. A pronounced peak was found in liver at 12 days of incubation, while only small differences were observed in brain. Lanosterol and cholesterol were the major sterols synthesized in brain, followed by desmosterol and squalene. Their relative percentages did not change significantly during 10–16 days and slightly decreased thereafter. In liver, cholesterol and equalene were the major sterols observed during the first days of incubation with a developmental pattern similar to that found in the mevalonate incorporation into nonsaponifiable lipids, while relative percentage of squalene oxides sharply increased between 12 and 16 days of embryonic development. The importance of cholesterol esters accumulation in the inhibition of cholesterogenic activity is discussed.
Studies on noradrenergic alterations in relation to early phenobarbital‐induced behavioral changes
Authors: Yanai Joseph , Pick Chaim G.
Published: April 2003

Mice were exposed to phenobarbital prenatally (B offspring) by feeding their mother 3 g/kg phenobarbital in milled food on gestation days 9–18; control dams received unadulterated milled food. At age 50 days, B offspring had fewer fluorescing noradrenergic (NE) cells in the locus coeruleus than control (P < 0.001). Hippocampal NE levels were also lower in B than in control offspring, while the cerebellar NE levels of B offspring remained normal. Since B offspring are known to be deficient in their hippocampal eight‐arm maze behavior, an attempt was made to reverse the behavioral deficit by transplantation of normal embryonic locus coeruleus NE cells into the impaired hippocampus of B offspring. While sham and NE‐transplanted controls needed approximately 2 days to reach criterion in the maze, sham‐transplanted B required approximately 5 days to reach criterion (P < 0.01). The scores of NE‐transplanted B mice were similar to B and differed significantly from control (P < 0.01). Thus, it appears that the hippocampal behavioral deficits studied may not be related to alterations in locus coeruleus‐hippocampal NE innervations.
Acetylcholinesterase in neuroblastoma and neuroblastoma × glioma hybrid cells: Cellular localization and molecular forms
Authors: Melone M. A. R. , Longo A. , Taddei C. , Augusti‐Tocco G.
Published: April 2003

The cellular localization of acetylcholinesterase (ACHE) was investigated at the electron microscope (E.M.) in a neuroblastoma and neuroblastoma × glioma hybrid line, which differ for their ability to establish synaptic contacts. Only cells of the latter line show association of AChE to the plasmamembrane, while in the former the activity is mainly intracellular. Sucrose sedimentation analysis of AChE molecular forms has shown no significant differences in the distribution of the two forms, G2 and G4, between the two cell lines. On the contrary a marked difference is observed in the ability of the cell to release the enzyme in the culture medium. In fact the cells lacking AChE on their surface release in the medium a much higher proportion of their enzyme, than the cells showing AChE association to their plasmamembrane. The possible role of two alternative fates for AChE, secretion or membrane insertion, in determining the observed differences of enzyme localization is discussed.
A developmental influence of substance P on its receptors
Authors: Handelmann Gail E. , Shults Cliff W. , O'Donohue Thomas L.
Published: April 2003

Events which alter the chemical environment of the developing nervous system have longterm consequences for neural function and behavior. Neonatal exposure to a peptide neurotransmitter, substance P (SP), increased the number of SP binding sites in the adult rat salivary glands, without altering their affinity. The neonatal treatment also increased the binding capacity for SP of several brain regions, but had no effect on SP levels in the brain. The increase in SP binding sites may be responsible for increases in sensitivity to SP in adults after neonatal treatment with the peptide.
Age‐dependent β‐adrenergic response of neuronal discharge in the raphe dorsalis: Evidence of a transient regulation
Authors: Lanfumey Laurence , Adrien Joëlle
Published: April 2003

Extracellular recordings from raphe dorsalis neurons in rats during development were performed, and the response to iontophoretically applied β‐antagonists was analysed. In pups younger than 2 weeks, raphe dorsalis firing was totally or partially inhibited by application of β‐antagonists, while after 2 weeks of age the neurons were insensitive to the same application. The β‐receptors appeared to be involved in the control of raphe firing during a transient period of ontogenesis and thus the disappearance of β‐regulation at older ages may reflect the regression of this population of neurotransmitter receptors.
Latex beads phagocytosis capacity and ecto‐NAD+ glycohydrolase activity of rat brain microglia cells in vitro
Authors: Bocchini V. , Rebel G. , Massarelli R. , Schuber F. , Muller C. D.
Published: April 2003

Conditions are described which allow the preparation in vitro of pure (> 95%) microglial cell cultures isolated from newborn rat brain. Such ameboid cells cultivated in vitro can efficiently phagocytize opsonized latex beads and are capable of ingesting more (100–200 beads of 1.1 μm diameter per cell) and larger (6.4 μm) particles than other nerve cells, such as oligodendrocytes and astroglia. The microglial cells also show an important ecto‐NAD+ glycohydrolase activity which is characteristic of phagocytic cells. We noted that the phagocytic capacity and ecto‐NAD+ glycohydrolase of these cells were correlated and increased notably during the in vitro culture.

Microglia cultivated in vitro appear to be a good model to study the activation of phagocytic properties in the central nervous system and corresponding modulation by natural or pharmacological immunomodulators.
Effects of calcium ion on neurite outgrowth of rat spinal cord neurons in vitro: The role of non‐neuronal cells in regulating neurite sprouting
Authors: Hantaz‐Ambroise D. , Trautmann A.
Published: April 2003

The interactions of nerve cells with their environment and other cells are specific to different stages of cellular differentiation. Neurite outgrowth was measured from cultured spinal cord neurons under the influence of different Ca2+ concentrations. We used fluorodeoxyuridine (FuDr), an antimitotic agent which reduces significantly the proportion of non‐neuronal cells in spinal cord cell cultures, to examine the effects of non‐neuronal cells on neurite outgrowth. Spinal cord neurons responded to changes in their environment by means of two types of neurite outgrowth: sprouting and elongation. The concurrent presence of non‐neuronal cells led to increased sprouting of neurites in certain ionic environments, thus lending support to the idea that non‐neuronal cells release diffusible factors which influence sprouting and guide neurite outgrowth.
Malic enzyme activity in the developing rat brain in relation to thyroid status
Authors: Thakare U. R. , Shah D. H. , Vijayan U.
Published: April 2003

Malic enzyme activity in the soluble fraction of neonate brains from mothers fed with propylthiouracil (0.015% w/v) in drinking water from day 12 of the gestation period was significantly lowered (P < 0.01) as compared to the offspring of normal mothers. Supplementation of triiodothyronine to the neonates from experimental mothers restored the malic enzyme activity to normal levels. However, administration of triiodothyronine to adult control rats did not influence malic enzyme activity in the brains of these animals. Our data suggest that during the initial critical period of brain maturation, malic enzyme is under the control of thyroid hormones. The response of malic enzyme towards thyroid hormones is lost once the brain has matured.
Soluble neural cell adhesion molecule in brain, cerebrospinal fluid and plasma in the developing rat
Authors: Dalseg Anne‐Marie , Linnemann Dorte , Bock Elisabeth
Published: April 2003

Neural cell adhesion molecule (NCAM) is a glycoprotein found in neurons, glial cells and muscle cells. In this report we describe the polypeptide composition and amount of soluble NCAM in brain, cerebrospinal fluid (CSF) and plasma in rats of various ages. One‐two percent of total NCAM in rat brain was shown to be buffer‐soluble. Soluble NCAM in brain, extracted at pH 7.2, constituted an increasing relative proportion of total NCAM during development, whereas the concentration of soluble NCAM in both CSF and plasma decreased in the same period. By radioiodination of brain extracts, CSF, and plasma, soluble NCAM was found to be composed of up to five polypeptides with molecular weights (Mr) of 200,000, 170,000, 150,000, 115,000 and 80,000. The relative composition did not vary significantly with age. The major forms in brain were the polypeptides with Mr of 200,000 and 115,000, whereas in CSF all forms seemed to appear in equal amounts. In plasma the 200,000 and the 170,000 Mr polypeptides were not observed and here the major forms were the 150,000 and 115,000 Mr polypeptides.
Patterns of transiently expressed acetylcholinesterase activity in cerebral cortex and dorsal thalamus of developing rats with cytotoxin‐induced microencephaly
Authors: Robertson Richard T. , Gragnola Thomas G. , Yu Jen
Published: April 2003

Previous studies have demonstrated that acetylcholinesterase (AChE) activity is expressed transiently by thalamocortical neurons of primary sensory systems in developing rat pups. In the present study, prenatal treatment with methylazoxymethanol acetate (MAM) on embryonic day 15, 16, or 17 resulted in rat pups with cerebral cortices markedly reduced in thickness and areal extent. Histochemical studies demonstrated that AChE staining occurs in fiber‐like plexuses in primary visual, auditory, and somatosensory regions of developing cerebral cortex of MAM‐treated animals, just as in normal developing rats, but that the transient patterns of AChE are found more superficially than normal and they occur in an abnormal patchy distribution. Neuronal somata in thalamic lateral geniculate, medial geniculate and ventral basal nuclei of MAM‐treated animals show transient AChE staining indistinguishable from that seen in normal animals. These data indicate: (1) AChE is expressed transiently by thalamocortical neurons in MAM‐treated animals, (2) intensity of the transiently expressed AChE is not affected by MAM‐induced loss of cortical neurons, and (3) the abnormal AChE patterns in cortex likely reflect the abnormal distributions of thalamocortical terminal fields that are characteristic of MAM‐treated animals.
Effect of thyroid deficiency on actin mRNA content in the developing rat cerebellum
Authors: Faivre‐Sarrailh C. , Ferraz C. , Liautard J. P. , Rabié A.
Published: April 2003

The actin mRNA content of the cerebellum was determined in normal and hypothyroid developing rats using RNA dot hybridization with a β‐actin cDNA probe. The decline in actin mRNA content occurring during the second postnatal week in normal development was delayed by about 1 week in hypothyroid rats. Since this effect coincides exactly with the delay in actin filament formation recently reported in thyroid‐deficient rats, it strengthens the hypothesis of an inverse relationship in the developing brain between the polymerization state of actin and the production of actin mRNA.
Age‐related changes in uptake and release on l‐[3H]noradrenaline in brain slices of senescence accelerated mouse
Authors: Zhao Xue‐Hui , Nomura Yasuyuki
Published: April 2003

High K+ and N‐methyl‐d‐aspartate (NMDA) evoked l‐[3H]noradrenaline (NA) release to a similar degree in the brain slices of 1‐month‐old senescence‐accelerated resistant mice (SAM‐R/1) and senescence‐accelerated prone mice (SAM‐P/8). However, 30 mM KCl‐induced l‐[3H]NA release significantly diminished in SAM‐P/8 from 3 to 12 months without changing in SAM‐R/1. In addition, NMDA‐induced l‐[3H]NA release was also reduced at 3 months and lowered to a level of spontaneous release at 12 months in SAM‐P/8, but no age‐related changes in SAM‐R/1 were observed. It is suggested that NA release from NA nerve terminals responsive to depolarization is reduced in SAM‐P/8 at an earlier stage than in SAM‐R/1. Furthermore, NMDA receptors which could be localized in the soma and/or nerve terminals, seem to be involved in NA release and to be decreased with advancing age in SAM‐P/8.