bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractActivity‐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

AbstractThe 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.
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

AbstractThe 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

AbstractRats 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

AbstractEnzymatic 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

AbstractThe 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

AbstractBinding 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

AbstractThe 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

AbstractWe 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

AbstractWe 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

AbstractModifications 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

AbstractThe 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

AbstractIn 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

AbstractA 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.
Cerebral endothelial cell‐derived laminin promotes the outgrowth of neurites in CNS neuronal cultures
Authors: Pákáski Magdolna , Kása Péter , Joó Ferenc , Wolff Joachim R. 
Published: April 2003

AbstractThe aim of the present study was to elucidate whether the endothelial cells, besides providing the structural basis for the blood‐brain barrier (M. Bradbury, Concept for a Blood‐Brain Barrier, 1979; F. Joó, Nature321, 197–198, 1986) can also produce laminin and, via its release, regulate the growth of neuntes of neurons originating from the central nervous system (CNS). In immunohistochemical investigations, the presence of laminin‐like immunoreactivity could be detected in the cytoplasm and on the surface of endothelial cells derived from brain microvessels. Further, the neurite‐promoting effect of laminin on CNS neurons was also noted in a co‐culture system designed especially for conditioning nerve cell cultures continuously with materials released from the cerebral endothelial cells. It is suggested that the endothelial cells may be involved via their laminin secretion in the regulation of axonal growth and guidance in the CNS.
The effects of intrauterine growth retardation on the development of neuroglia in fetal guinea pigs. An immunohistochemical and an ultrastructural study
Authors: Nitsos Ilias , Rees Sandra 
Published: April 2003

AbstractThe effects of intrauterine growth retardation on the development of myelinating oligodendrocytes and astrocytes in the brain and spinal cord of the fetal guinea pig have been examined using immunohistochemical and ultrastructural techniques. As judged by immunoreactivity for myelin basic protein, the extent of myelination in the spinal cord, cerebral cortex, corpus cellosum and cerebellum was reduced in the growth‐retarded fetuses compared with controls at both 52 (n = 4) and 62 days (n = 5) of gestation. As assessed by immunoreactivity for glial fibrillary acidic protein, there were no marked differences between control and growth‐retarded brains in the extent or distribution of radial glial cells or astrocytes at 52 or 62 days in the cerebellum. However, in the cerebral cortex at 62 days there was a striking proliferation of astrocytes surrounding cortical blood vessels in growth‐retarded fetuses. Ultrastructural studies showed that at 52 days, myelination of the corticospinal tract had begun in the control but was virtually absent in growth‐retarded fetuses. At 62 days, the total number of myelinated fibres in growth‐retarded fetuses was significantly reduced by 56% (P < 0.01) compared with control fetuses; however, there was no difference between the groups in the total number of fibres in the corticospinal tract. Where fibres were myelinated the myelin sheath was disproportionately reduced relative to axon diameter. Thus, in intrauterine growth retardation there is a delay in the initiation and in the extent of myelination. This could be due to a reduction in the number of myelinating glia formed and the restricted capacity of those which do form to generate myelin.
Studies on brain monoamine and neuropeptide systems after neonatal intracerebroventricular 6‐hydroxydopamine treatment
Authors: Luthman J. , Brodin E. , Sundström E. , Wiehager B. 
Published: April 2003

AbstractIn order to study the effects of a neonatal dopamine lesion on dopaminergic, serotonergic and peptidergic systems, Sprague‐Dawley rats were treated by intracerebroventricular administration of 6‐hydroxydopamine (100 μg, days 3 and 6) following desipramine pretreatment (25 mg/kg s.c.).At 60–70 days postnatally a profound reduction of dopamine‐ and 3,4‐dihydroxyphenylacetic acid levels was found in striatal and limbic forebrain regions concomitant with an extensive loss of tyrosine hydroxylase‐immunoreactive fibers, while no significant alteration in noradrenaline levels was seen. A marked loss of tyrosine hydroxylase‐immunoreactive cell profiles was also observed in the substantia nigra and ventral tegmental area in mesencephalon. In striatum, but not in other regions analysed, an almost 100% increase in serotonin levels and serotonin‐immunoreactive fiber density was observed following 6‐hydroxydopamine treatment. However, the number of serotonin‐immunoreactive cell profiles in the median and dorsal raphe nuclei was not altered. The 6‐hydroxydopamine treatment also led to reductions in substance P levels in striatum, nucleus accumbens and ventral mesencephalon. The cholecystokinin level in nucleus accumbens and neurotensin level in ventral mesencephalon were also reduced. A neonatal intracerebroventricular 6‐hydroxydopamine treatment thus leads to a les̀ion of dopamine neurons in the mesencephalon with extensive loss of dopamine fibers in several forebrain areas, while localized serotonin fiber sprouting is induced in striatum. Furthermore, concomitant reductions of the levels of peptides related to the dopamine system occur following the 6‐hydroxydopamine treatment. Behavioral disturbances such as hyperactivity and cognitive deficiencies occurring after a dopamine lesion early in life might therefore be due to plastic alterations in several different transmitter/ neuromodulator systems as a direct or indirect consequence of the lesion.
Quantitative histochemical changes in enzymes involved in energy metabolism in the rat brain during postnatal Development. I. Cytochrome oxidase and lactate dehydrogenase
Authors: Bilger Anne , Nehlig Astrid 
Published: April 2003

AbstractThe postnatal maturation of cytochrome oxidase and lactate dehydrogenase activity was assessed by histochemistry in rats at 8 postnatal stages, P0, P5, P10, P14, P17, P21, P35 and the adult stage. Enzyme activities were revealed on cryostat brain sections with diaminobenzidine for cytochrome oxidase and nitroblue tetrazolium for lactate dehydrogenase. Lactate dehydrogenase activity remained unchanged between P0 and P10, significantly increased in 8 areas of the 14 studied between P10 and P14 and in 6 structures from P14 to P17. These were mainly parietal, auditory and cerebellar cortices, hippocampus, thalamus, hypothalamus and medial geniculate body. There was no further change until P35 and lactate dehydrogenase activity increased then significantly to reach higher adult levels in hippocampus and medial geniculate body. Cytochrome oxidase activity was low from P0 to P10 and increased in 8 regions between P10 and P14. These were all cortices, caudate nucleus, hippocampus, inferior colliculus and genu. Enzyme activity further increased between P14 and P17 in auditory cortex, medial geniculate body and brainstem, did not vary from P17 to P21 but increased by 92 to 371% in all areas between P21 and P35. Cytochrome oxidase activity rose further from P35 to adult stage in hippocampus and medial geniculate body. From birth to adulthood, cytochrome oxidase activity increased 5 to 19 fold and lactate dehydrogenase activity 1.8 to 3.0. The present study shows that there is a quite good correlation between postnatal changes in regional cerebral glucose utilization and activity of enzymes involved in glycolytic and oxidative glucose metabolism in the rat.