bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrocyte cultures from human embryonic brain: Characterization and modulation of surface molecules by inflammatory cytokines
Authors: Aloisi F. , Borsellino G. , Samoggia P. , Testa U. , Chelucci C. , Russo G. , Peschle C. , Levi G.
Published: May 2005

Astrocyte‐enriched cultures were established upon passaging of primary cultures from the myelencephalon and mesencephalon of 7–9‐week‐old human embryos. Immunocytochemical analysis showed that third‐fourth passage cultures were composed of a highly enriched population of proliferating, epithelioid cells, up to 90% of which expressed glial fibrillary acidic protein (GFAP); no macrophages and very few fibroblasts (>2%) were present. GFAP expression and proliferation declined upon further culturing in serum‐containing medium but could be transiently reinduced by growing the cells in a serum‐free chemically defined medium. Large numbers of GFAP+ astrocytes were obtained from each embryo and could be stored frozen and recultured.

Using flow cytometric analysis, human astrocyte cultures were examined for basal and cytokine [interferon‐γ (IFN‐γ), interleukin‐1β (IL‐1β), and tumor necrosis factor‐α (TNF‐α)]‐induced expression of molecules that may be involved in astrocyte‐T‐lymphocyte interactions. Cultured human astrocytes spontaneously expressed major histocompatibility complex (MHC) class I antigens and variable levels of MHC class II; MHC class I levels were increased upon IFN‐γ and TNF‐α treatment, whereas MHC class II antigens were induced on most of the astrocytes by IFN‐γ. Among the molecules involved in antigen‐independent interactions between T lymphocytes and target cells, lymphocyte function‐associated molecule‐3 (LFA‐3) was spontaneously expressed by most cultured human astrocytes, whereas intercellular adhesion molecule‐1 (ICAM‐1) was present at variable levels in non‐stimulated astrocytes and was greatly induced by IFN‐γ, TNF‐α, and IL‐1β. In this study we also show that the above cytokines upregulate astroglial expression of adhesion molecules of the integrin family (VLA‐1, VLA‐2, and VLA‐6) that may be involved in astrocyte‐extracellular matrix interaction and play a role in the astrocyte reactive changes occurring at sites of brain injury and inflammation.

The human astrocyte cultures developed here represent a useful in vitro model to further investigate mechanisms involved in bidirectional communication between central glia and cells of the immune system. © 1992 Wiley‐Liss, Inc.
Myelin protein expression in dissociated superior cervical ganglia and dorsal root ganglia cultures
Authors: Brunden Kurt R. , Ding Y. , Hennington B. S.
Published: May 2005

Schwann cells of the adult rat superior cervical ganglia (SCG) synthesize negligible levels of the major myelin glycoprotein, P0, in vivo. This suggests that the sympathetic axons of the SCG are deficient in one of more components involved in the regulation of myelin protein expression. Here we have compared the ability of neurites from neonatal rat SCG and embryonic rat dorsal root ganglia (DRG) to induce Schwann cell expression of myelin proteins after growth in culture using a serum‐free medium. Steady‐state P0 mRNA levels in the SCG and DRG culture paradigms were determined with a sensitive polymerase chain reaction (PCR) assay that amplified cDNA produced by reverse transcription of mRNA. This semiquantitative assay showed a linear response to increasing amounts of P0 and actin mRNA and required substantially less cellular RNA than typical hybridization techniques. Using the PCR assay, we found that SCG cultures contained significantly lower amounts of P0 mRNA than did DRG cultures. To further confirm that SCG cultures have negligible expression of myelin proteins, immunoblot analyses were done to examine the steady‐state levels of both P0 and myelin basic protein. While nonmyelinating DRG cultures had readily detectable amounts of these myelin‐specific proteins, neither could be demonstrated in the SCG cultures. The data indicate that SCG neurites lack one or more signals needed to induce myelin protein expression. Employing SCG and DRG cultures in comparative biochemical studies should prove useful in identifying the axonal molecule(s) involved in the regulation of myelin protein expression. © 1992 Wiley‐Liss, Inc.
Expression of the Class III β‐tubulin isotype in developing neurons in culture
Authors: Ferreira Adriana , Caceres A.
Published: May 2005

The expression of the class III β‐tubulin isotype was studied in cultured brain neurons by means of a monoclonal antibody (TuJ1). The results obtained indicate that during early axonal outgrowth most of the class III β‐tubulin is not incorporated into microtubules, a phenomenon which is also observed under conditions which alter the rate and extent of the neurite outgrowth response. On the other hand, a dramatic increase in its incorporation into microtubules is observed after the neurons have differentiated their neurites as axons and dendrites. In addition, the appearance of colchicine‐resistant microtubules containing this isotype, a phenomenon which occurs late in neurite development, is highly coincident with the appearance of stable microtubules containing high molecular weight microtubule‐associated proteins (MAPs). This pattern is different from that of the accumulation and incorporation of other β‐tubulin isotypes into microtubules. Taken collectively, our results indicate that differences exist in the in vivo utilization of tubulin isotypes in developing brain neurons and suggest that the class III β‐tubulin isotype is not a primary factor involved in the regulation of microtubule assembly during early neurite out‐growth, but that it may be important for maintaining further neurite elongation and/or determining some unique binding property of MAPs to specific microtubule subsets. © 1992 Wiley‐Liss, Inc.
Effects of bright artificial light on monoamines and neuropeptides in eight different brain regions compared in a pigmented and nonpigmented rat strain
Authors: Humpel C. , Neudorfer C. , Philipp W. , Steiner H. J. , Haring C. , Schmid K. W. , Schwitzer J. , Saria Alois
Published: May 2005

Seasonal affective disorder is a form of depression which recurs at the same time of the year. Exposure to bright artificial light at a dose of 2,500 lux is used to treat seasonal affective disorders. We exposed a pigmented (Brown Norway) and a nonpigmented (Sprague‐Dawley) rat strain with bright artificial light for 21 days at two doses (2,500 and 6,100 lux) and analyzed dopamine, dihydroxyphenyl‐acetic acid, 5‐hydroxytryptamine (5‐HT), and 5‐hydroxyindole‐acetic acid (5‐HIAA) by high performance liquid chromatography (HPLC) and electrochemical detection in eight different brain regions. Furthermore, we measured tissue levels of substance P (SP), neurokinins (NK), vasoactive intestinal polypeptide (VIP), calcitonin gene‐related peptide (CGRP), and neuropeptide Y (NPY) with radioimmunoassay. Our data obtained with light microscopy show that bright artificial light at both doses induced a massive destruction of photoreceptors in the retina of albino rats but not of the pigmented rat strain. Retinal lesion of photoreceptors resulted in increased tissue levels of all measured neuropeptides except SP in the hypothalamus and increased VIP in the ventral tegmental area/substantia nigra. Furthermore, increased 5‐HT and 5‐HIAA tissue levels were found in the ventral tegmental area/substantia nigra. In contrast, in the frontal cortex there was a significant reduction in 5‐HIAA tissue levels and a decreased 5‐HIAA/5‐HT ratio, indicating decreased 5‐HT metabolism. Light exposure of the pigmented rat strain revealed no changes in the measured biogenic amines and neuropeptides in any investigated brain region. Our data suggest that retinal lesion but not direct visual neurotransmission induced changes in neurotransmitters in some brain regions. We conclude that Brown Norway rats but not Sprague‐Dawley rats are useful to study neurochemical effects of bright artificial light. However, Sprague‐Dawley rats may be a useful tool to study biochemical mechanisms of photoreceptor damage by bright light. © 1992 Wiley‐Liss, Inc.
Surface behavior of axolemma monolayers: Physico‐chemical characterization and use as supported planar membranes for cultured Schwann cells
Authors: Calderon Reyna O. , Maggio B. , Neuberger T. J. , Devries G. H.
Published: May 2005

The axolemma membrane forms a stable and reproducible monomolecular layer at the air‐aqueous interface. The major lipids and proteins are present in this monolayer in molar ratios similar to the original membrane. Acetylcholinesterase and Na‐K‐ATPase activities are preserved in the monolayer to levels of 64% and 25%, respectively. The total lipid fraction forms a homogeneously mixed phase. The presence of proteins in the monolayer introduces surface inhomogeneties. Among other features, this is revealed by the presence of two values of lateral pressure at which the monolayer shows partial or total collapse: a broad partial collapse at surface pressures between 13 to 30 mN/m and a sharp collapse point at 46 mN/m. The average molecular areas, the broad collapse point, and the variation of the surface potential per molecule suggest the relocation of protein components at surface pressures between 13 to 30 mN/m. The behavior is consistent with the extrusion and exposure of proteins toward the aqueous medium that depends on the lateral pressure.

Schwann cells grown on coverslips coated with axolemma monolayers at 13 mN/m (beginning of the broad collapse) and 34 mN/m (above the broad collapse) recognize the difference in the surface organization of axolemma caused by the lateral pressure which affects their proliferation, morphology, and spatial pattern of organization. Our results show for the first time that response of Schwann cells depends on the intermolecular organization of the axolemma surface with which they interact. These results suggest that the local expression of putative surface molecules of axolemma that may mediate membrane recognition and the signalling of morphological and proliferative changes can be modulated by long range supramolecular properties. © 1993 Wiley‐Liss, Inc.
Arachidonic acid lipoxygenation may mediate interleukin‐1 stimulation of nerve growth factor secretion in astroglial cultures
Authors: Čarman‐Krž M. , Wise Bradley C.
Published: May 2005

Interleukin‐1β (IL‐1) stimulates by about fivefold NGF secretion from rat neonatal cortical astrocytes in primary culture. We investigated the possible intracellular second messenger mechanisms involved in the IL‐1 induced NGF secretion. Basal NGF secretion did not require extracellular Ca2+, whereas Ca2+ was necessary for the maximal NGF secretion stimulated by IL‐1 (10 units/ml). The protein kinase C activator TPA stimulated by sixfold NGF secretion, but in this case, TPA acted synergistically with IL‐1 to increase NGF secretion. Treatment of cells with the phospholipase A2 inhibitor mepacrine (30 μM) inhibited basal (by 50%) and IL‐1 stimulated (by 80%) NGF secretion. Indomethacin, a cyclooxygenase inhibitor, produced a slight increase in basal NGF secretion at low concentrations, while PGE2 (10 μM) inhibited basal and IL‐1 stimulated NGF secretion. In contrast, treatment of cells with nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, blocked in a concentration‐dependent manner (IC50 = 10 μM) IL‐1 stimulation of NGF secretion. The leukotriene LTB4 increased basal NGF secretion and this effect was not additive with IL‐1 when both agents were added at saturating concentrations, indicating a common mechanism of action for these two agents. Thus, one possible mechanism by which IL‐1 stimulates NGF secretion from astrocytes is by activation of the phospholipase A2‐lipoxygenase pathway. © 1993 Wiley‐Liss, Inc.
Recognition of the minimal epitope of monoclonal antibody Tau‐1 depends upon the presence of a phosphate group but not its location
Authors: Szendrei G. I. , Lee V. M.‐Y. , Otvos L.
Published: May 2005

The major constituent of the paired helical filaments (PHFs) of Alzheimer's disease is the abnormally phosphorylated form of the microtubule‐associated protein, τ. Monoclonal antibody (mAb) Tau‐1 is used extensively to stain normal human τ, and τ isolated from the brains of Alzheimer's disease patients after dephosphorylation. We used a panel of 6 synthetic peptides to localize the minimal epitope of Tau‐1 between amino acids 192–204. All 4 serine residues within this fragment were later phosphorylated individually by chemical methods, and it was shown that none of the peptides carrying a single phosphate group were recognized by the antibody. The serines included those that are probably not transformed in AD and consequently, conclusions drawn about malfunctioning kinase activity, based on Tau‐1 immunoreactivity, can be extremely misleading. The recognition was restored at a decreased level when one of the serines was replaced by an alanine residue. mAb AT8 was made by immunizing with the PHFs and was reported to recognize the same region of the protein in a phosphorylated form. AT8 did not, however, cross‐react with any of the singly phosphorylated peptides, indicating that the recognition site of the two antibodies are not entirely complementary or the binding to AT8 needs multiple phosphorylation of the antigen. The abolished recognition of the phosphorylated peptides cannot be attributed to a conformational change due to phosphorylation, since all peptides exhibited reverse‐turn secondary structures, as indicated by circular dichroism (CD) spectroscopy. Ant‐τ mAbs may distinguish between phosphorylated and non‐phosphorylated forms of epitopes regardless of the location of the phosphate group. © 1993 Wiley‐Liss, Inc.
Long‐term induction of c‐jun mRNA and jun protein in rabbit retinal ganglion cells following axotomy or colchicine treatment
Authors: Koistinaho J. , Hicks K. J. , Sagar S. M.
Published: May 2005

The expression of the c‐jun, c‐fos, and NGFI‐A genes was studied in the rabbit retina after optic nerve crush (ONC) or an intravitreal injection of colchicine. By Northern blotting, the basal expression of c‐fos and NGFI‐A mRNAs were undetectable, whereas c‐jun mRNA showed a low basal expression in shamoperated control retinas. Very few or no Jun‐ or Fosimmunoreactive nuclei were seen in control retinas. From 1 to 95 days after ONC a marked induction of JUN‐ but not FOS‐immunoreactive neurons was seen in the ganglion cell layer peaking at 3 and 7 days. Jun‐positive neurons also accumulated immunoreactive phosphorylated neurofilaments, indicating that they were ganglion cells. Northern blots demonstrated that retinal levels of c‐jun mRNA, but not of c‐fos or NGFI‐A mRNAs, were increased 3 and 7 days after ONC. An intravitreal injection of colchicine also induced Jun‐immunoreactivity within 24 hr in most of the neurons in the ganglion cell layer, but not in the inner nuclear and outer nuclear layers. The results indicate that axonal damage induces a specific pattern of IEG expression including a long‐term induction of the c‐jun gene in CNS neurons. © 1993 Wiley‐Liss, Inc.
Migrated fetal astrocytes modulate nerve growth factor expression in host nucleus gracilis of the medulla after grafting in third cervical hindlimb dorsal columns of the spinal cord
Authors: Bernstein J. J. , Willingham L. A. , Goldberg W. J.
Published: May 2005

Nerve growth factor (NGF) immunoreactivity in the nucleus gracilis of the medulla was quantitated for 90 days after aspiration of the C3 spinal hindlimb dorsal columns of 36 adult rats. Half the lesioned animals were a lesion‐only group. The remaining lesioned animals received an immediate graft of two 1.0‐mm pieces of 14 day gestation fetal rat cervical spinal cord (prelabeled with Phaseolus vulgaris leucoagglutinin) into the aspiration pocket (graft group). There were 3 normal controls. Groups of animals were analyzed at 7, 14, 21, 30, 60, and 90 days. At 90 days, NGF immunoreactivity was significantly elevated in the nucleus gracilis of lesion‐only animals. This increase in NGF immunoreactivity was augmented in glial end‐feet surrounding neurons and was also observed in the cytoplasm of astrocytes and some neurons. Previous experiments have shown that the cluster neurons of the nucleus gracilis undergo atrophy at this time with a concomitant decrease in hindlimb placement. NGF immunoreactivity (90 days) in grafted animals, however, was significantly less than in lesion‐only animals (P < 0.05) but remained significantly elevated above control animals (P < 0.05). Unlike in lesion‐only animals, there were no NGF positive neurons in the nucleus gracilis of grafted animals. Previous experiments have shown that astrocytes from fetal spinal cord grafts migrate to the nucleus gracilis, maintain cluster neuron cell size, and improve hindlimb placement at 90 days. The present data indicate that modulation of detrimental increases in NGF appeared to be a mechanism by which migrated fetal astrocytes can be used as a system for cell therapy. © 1993 Wiley‐Liss, Inc.
A developmentally regulated microsomal protein specific for the pigment epithelium of the vertebrate retina
Authors: Hamel C. P. , Tsilou E. , Harris E. , Pfeffer B. A. , Hooks J. J. , Detrick B. , Redmond T. Michael
Published: May 2005

In the vertebrate retina, the retinal pigment epithelium (RPE) performs specific functions critical to the normal process of vision. Although some of these functions are well documented, molecular data are still scarce. Using the RPE‐specific monoclonal antibody RPE9, raised against human RPE cells, we have identified a novel 65 kD protein, conserved in mammals, birds, and frogs. This RPE‐specific protein was found to be nonglycosylated. It was most effectively solubilized in the presence of detergent suggesting that it is associated with the RPE cell membranes. Its partitioning in the detergent phase of Triton X‐114 and its solubilization in 0.75 M and 1.0 M KCl suggest that it interacts with the membrane either through a polypeptide anchor or charged amino acids. Cell fractionation by differential solubilization and differential centrifugation demonstrated that the protein was preferentially associated with the microsomal membrane fraction, where it is the major protein. Developmental expression of this 65 kD protein was examined in neonatal rats. Morphologically well‐differentiated RPE cells did not express the 65 kD protein at birth. However, expression was detectable at postnatal day 4, that is, one to two days before the photoreceptors develop their outer segments, suggesting that the expression of the 65 kD protein may be coordinated with other developmental events in the intact retina. This is further supported by the fact that RPE cells in confluent culture lose the expression of this protein within two weeks, while they maintain their characteristic epithelial morphology. Because of its specificity, its evolutionary conservation, and its timing of expression, it is possible that this protein may be involved in one of the key roles of RPE and as such is an important molecular marker for RPE differentiation. © 1993 Wiley‐Liss, Inc.
Perinatal morphine treatment inhibits pruning effect and regeneration of serotoninergic pathways following neonatal 5,7‐HT lesions
Authors: Gorio Alfred , Di Giulio A. M. , Germani E. , Bendotti C. , Bertelli A. , Mantegazza P.
Published: May 2005

Lesion of the serotoninergic system in neonate rats is an ideal model for assessing the activity of chemical substances capable of affecting neuronal plasticity and regeneration (Jonsson et al., Dev Brain Res 16:171–180, 1984). Treatment of newborn rats within 6 hr from birth with the selective neurotoxin 5,7‐dihydroxytriptamine causes degeneration of the most distal serotoninergic axons. In our experimental conditions we have observed that after such neurotoxic treatment there is spinal cord denervation, which is particularly remarkable in the lumbar segment. This degenerative event is followed by gradual regeneration of the lesioned axons, with good reinnervation of the entire cord within 8 weeks. The degeneration‐regeneration process is correlated with a transient hyperinnervation of the pons‐medulla and hypothalamus by the short collaterals (pruning effect), as evidenced by increased serotonin content. Perinatal morphine exposure markedly impairs serotonin regeneration in the spinal cord. In addition, opiate treated rats are more susceptible to lesions, as shown by the neurotoxin induced denervation of the cortex, pons‐medulla, and hypothalamus, which does not occur in lesioned controls. Therefore, our observations suggest that perinatal exposure to morphine affects the plasticity and regeneration of the developing serotoninergic system by increasing its susceptibility to neurotoxic lessions and reducing its regenerative capacity. © 1993 Wiley‐Liss, Inc.
Interferon‐γ inhibits DNA synthesis and insulin‐like growth factor‐II expression in human neuroblastoma cells
Authors: Martin D. M. , Carlson R. O. , Feldman E. L.
Published: May 2005

Interferon‐γ (IFN‐γ) is known to be an antiproliferative, differentiation agent in many cell types, including neuroblastoma. In this study, we determined the effects of IFN‐γ on cellular growth and expression of insulin‐like growth factor II (IGF‐II) and IGF receptors in the human neuroblastoma cell line SH‐SY5Y. Incubation of SH‐SY5Y cells in IFN‐γ (20–100 U/ml) induced the formation of long neuritic processes. IFN‐γ treatment also induced decreases in [3H]TdR incorporation, as well as serum‐dependent changes in cell number. Treatment with IFN‐γ reduced cell number 33% in the presence of serum but had no effect on cell number in the absence of serum. IGF‐II mRNA content was 60% inhibited by IFN‐γ, and was not serum dependent. The concentration of immunoreactive IGF‐II in SH‐SY5Y conditioned medium was also reduced in the presence of IFN‐γ, to less than half of control levels. In contrast, type I IGF receptor mRNA content was increased more than three‐fold after treatment with IFN‐γ and serum. Co‐incubation in IFN‐γ (20–100 U/ml) and IGF‐II on (3–10 nM) prevented the inhibitory effects of IFN‐γ on [3H]TdR ncorporation in serum‐free media. Our results suggest that IFN‐γ may inhibit DNA synthesis and cell growth by interfering with an IGF‐II/type I IGF receptor autocrine growth or survival mechanism.
Neuropeptide Y‐producing neurons of the arcuate nucleus regenerate axons after surgical deafferentation of the mediobasal hypothalamus
Authors: Alonso G. , Privat A.
Published: May 2005

Dorsolateral and ventomedial surgical deafferentation of the hypothalamus were used to study the capacity of different types of neuropeptide Y‐containing axons afferent to the dorsal hypothalamus to regenerate through surgical lesions. The kinetics of the postlesional responses of transected neuropeptide Y‐axons was studied on 30–40 μm thick vibratome sections, either (i) by light or electron microscopy after peroxidase immunostaining for neuropeptide Y or (ii) by confocal microscopy after double fluorescence immunostaining for neuropeptide Y and for glial fibrillary acidic protein. The dorsolateral cut was found to sever 2 main pathways containing neuropeptide Y axons located, respectively, below the bed nucleus of the stria terminalis and in the perifornical region. In both regions transected fibers were found to abut onto the surgical lesion, but even 45 days after the lesion, they were very rarely observed to penetrate into the astroglial scar formed along the lesion. The ventromedial cut was found to sever numerous neuropeptide axons that originate in the underlying arcuate nucleus. Seven to 15 days after the lesion neuropeptide Y fibers located below this type of cut presented a dramatic increase in both their numerical density and their immunostaining intensity. With increasing post‐surgery times, an increased number of neuropeptide Y fibers was observed to penetrate and to cross the lesional scar formed by densely packed astrocytic processes. Electron microscope observations further demonstrated that 45 days after the lesion, numerous neuropeptide Y‐immunoreactive axonal profiles were included in the scar matrix, which appeared to be mainly composed of closely interdigitating astrocytic processes containing dense bundles of filaments. These data indicate that, in contrast to other neuropeptide Y neurons innervating the dorsal hypothalamus, neuropeptide Y neurons of the arcuate nucleus regenerate axons through the astroglial scar produced by a surgical lesion placed in the ventromedial hypothalamus. © 1993 Wiley‐Liss, Inc.
Time‐dependent effects of insulin on Schwann cell proliferation in the in vitro regenerating adult frog sciatic nerve
Authors: Ekström P. A. R. , Edbladh M. , Edström A.
Published: May 2005

The present study showed that insulin (0.01 μg/ml, ≈︂ 2 nM) inhibited [3H]‐thymidine incorporation in support cells, most likely Schwann cells, of the cultured frog sciatic nerve. A 25–35% inhibition took place in regenerating nerve preparations as well as in preparations devoid of neuronal protein synthesis, i.e., in isolated 5 mm nerve segments and in gangliectomized nerves, suggesting that the effect was direct and not mediated via the neuronal cells. The inhibition by insulin was time‐dependent in that an effect was seen after 4 days but not at shorter or at longer periods of culturing. In separate experiments biotinylated insulin was shown to be taken up by Schwann cells in the regenerating nerve. Addition of serum increased the [3H]‐thymidine incorporation severalfold and abolished the inhibitory action of insulin. Our results suggest that insulin, at a certain stage of the regeneration programme, exerts a direct, inhibitory effect on the proliferation of the Schwann cells in the cultured frog sciatic nerve. © 1993 Wiley‐Liss, Inc.
Characterization of a transmissible growth‐promoting agent derived from CSF of schizophrenic patients which is active on human neuroblastoma cells
Authors: Shirabe Susumu , Stevens J. R. , Schwartz J. P.
Published: May 2005

A growth‐promoting agent for the human neuroblastoma cell line SK‐N‐SH(EP) (SH‐EP) has been detected in human cerebrospinal fluid (CSF) derived from schizophrenic patients. Following treatment with the CSF, a number of properties of the SH‐EP cells changed permanently. These included an accelerated rate of growth, an increased cell density at confluence, a change of cell shape, and an increased ability to form colonies in soft agar. All of these changes are consistent with further cellular transformation of the SH‐EP cells. Once the cells' properties had changed following CSF treatment, the growth‐promoting activity was found to be present in freeze‐thawed cell extracts and in the culture medium, and could be passed to untreated SH‐EP cells. The activity could be detected in culture media diluted as high as 108. It was inactivated by proteinases, chloroform, or heat but passed through a 0.22‐μm filter. The growth‐promoting activity can be banded on a Percoll gradient, suggesting that it is particulate rather than a soluble growth factor. © 1993 Wiley‐Liss, Inc.
Expression of non‐adrenergic imidazoline sites in rat cerebral cortical astrocytes
Authors: Regunathan S. , Feinstein D. L. , Reis D. J.
Published: May 2005

Clonidine and related imidazoline agents, beside binding to α2‐adrenergic receptors, have been shown to bind to a non‐adrenergic site (imidazoline sites) in brain and peripheral tissues. However, which cell types in brain, namely neurons or glia, express this binding site and the cellular effects of activation of this site are not known. We investigated the cellular localization of imidazoline binding sites in cultured rat cortical astrocytes and neurons. Membranes prepared from cultured astrocytes showed specific, high affinity binding (KD: 4 nM) for 3H‐idazoxan with about tenfold higher number of binding sites than α2‐adrenergic sites (Bmax: 220 vs. 20 fmol/mg protein). Displacement studies exhibited the rank order of potency: cirazoline > idazoxan > amiloride > clonidine >>> epinephrine = ruawolscine defining this site as I‐2a subtype of imidazoline binding sites. Moreover, the binding was inhibited by K+ but not by Na+, another characteristic of imidazoline binding sites. In contrast, membranes prepared from cultured neurons showed fewer binding sites for 3H‐idazoxan that were completely displaced by adrenergic agents. Incubation of astrocytes with idazoxan, but not rauwolscine, resulted in a concentration‐dependent increase in the levels of mRNA for the astrocyte specific molecule glial fibrillary acidic protein. We conclude that (a) the non‐adrenergic imidazoline binding sites are expressed in astrocytes but not in neurons in rat cerebral cortex and (b) these “receptors” may influence astrocyte physiology by regulating the levels of GFAP. © 1993 Wiley‐Liss, Inc.
Widespread constitutive expression of HSP90 messenger RNA in rat brain
Authors: Izumoto S. , Herbert J.
Published: May 2005

The distribution of constitutively expressed mRNA encoding 2 isoforms of heat shock protein 90 (HSP90) was investigated in adult rat brain by in situ hybridization with 35S‐labeled cRNA probes. HSP90 mRNA density was estimated by semiquantitative autoradiography and by microscopic analysis. The distribution of HSP90 transcripts was similar for the 2 probes. HSP90 mRNA was widespread but not ubiquitous, and labeling intensity varied among different regions. In particular, HSP90 mRNA was abundant in limbic system‐related structures, such as the hippocampus, amygdala, mamillary body, piriform cortex, enthorhinal cortex, bed nucleus of the stria terminalis, medial habenular nucleus, and preoptic hypothalamic nuclei. The highest abundance of mRNA was detected in the Purkinje cell layer of the cerebellum. High abundance was also present in pineal body, choroid plexus, cerebellar granule cell layer, and cranial nerve nuclei. HSP90 mRNA was present in moderate abundance throughout the cortical gray mantle, in the caudate‐putamen, most other thalamic and hypothalamic nuclei, the pontine and spinal gray matter, and the anterior lobe of the hypophysis. Weak hybridization was observed in white matter fiber tracts, glial cells, and leptomeninges, and none was observed in endothelial cells and the smooth muscle of the cerebral microvasculature. Our findings suggest that HSP90 gene products may serve constitutive neuron‐specific functions in the unstressed brain. © 1993 Wiley‐Liss, Inc.
Localized vibrations in GaP doped with Mn or As
Authors: Haanstra J. H. , Vink A. T.
Published: May 2005

Raman lines in GaP doped with Mn (0.1 at %) or As (up to 10 at %) are reported and discussed. In GaP‐Mn an impurity mode is found which also is observed in the low temperature luminescence. In GaP‐As five additional lines are seen. From the identification and relative intensities of these lines conclusions are drawn concerning the clustering of As ions around Ga ions.
Raman and infrared spectra and vibrational assignments of gallium (II) sulphide
Authors: Taylor Michael J.
Published: May 2005

The Raman and IR active vibrations of the GaS layer lattice are observed and assigned in comparsion with the related Ga – Ga bonded structures β‐GaSe and Ga2X62− (where X = Cl, Br or I).
Resonance Raman spectroscopic study on iodine in various organic solvents: Spectroscopic constants and halfband widths of the I2 vibration
Authors: Kiefer W. , Bernstein H. J.
Published: May 2005

Resonance Raman spectra have been obained from various iodine solutions. High intensity overtone progressions of the stretching vibration were observed, allowing the determination of the spectroscopy constants ωe and ωexe and estimation of ωeye for the stretching vibration for the ground state in various environments. The values are compared to those obtained for the gas phase. The overtone progression shows a large increase in half‐bandwidth with increasing vibrational quantum number.
Computer fitting of Voigt profiles to Raman lines
Authors: Sundius T.
Published: May 2005

A FORTRAN program has been developed for the accurate computation of the convolution of a Lorentzian with a Gaussian line shape (the Voigt function). This program has been included in a larger program written by the author to resolve overlapping lines in complex Raman spectra. It has been found that the program is very useful to determine accurate line widths and peak positions from slit‐distorted spectra, which is important in high‐resolution Raman spectroscopy.
High resolution vibrational Raman spectrum of oxygen
Authors: Fletcher William H. , Rayside John S.
Published: May 2005

The fundamental vibrational band of oxygen has been examined with a resolution of 0.05 cm−1 for the Q branch and 0.40 cm−1 for the S and O branches. All lines of the Q branch were clearly resolved except Q(1) and Q(3). Calculated molecular parameters agree with those previously reported from microwave and electronic spectra. Line width measurements made in the Q branch and on three S branch lines, using a resolution of 0.05 cm−1, are in fair agreement with previously measured and calculated line widths for pure rotational Raman lines.
Trisilylamine: Nitrogen isotope effect in the Raman spectrum and planarity of the NSi3 skeleton
Authors: Miller Foil A. , Perkins James , Gibbon Gerst A. , Swisshelm B. A.
Published: May 2005

Raman frequencies for the totally‐symmetric NSi3 stretching mode of 14N(SiH3)3 and 15N(SiH3)3 have been carefully compared. In the gas phase the isotopic shift is zero within experimental error, which indicates planar trigonal geometry for the heavy‐atom skeleton. For the liquid and solid phases there are small but real isotopic shifts. The skeleton is therefore slightly distorted in these phases, but it is impossible to say just how.

Complete Raman and infrared data are given for 14N(SiH3)3 in several physical states.
The external lattice vibrations of orthorhombic sulphur
Authors: Arthur J. W. , Mackenzie G. A.
Published: May 2005

The Raman spectrum of orthorhombic sulphur has been measured in the frequency range 0‐100 cm−1 for all polarisations. The A1g(zz) and B1g(xy) spectra have been clarified by later subtraction of unwanted scattering belonging to other polarisations. Definite assignments are made for all but one A1g and one B2g mode. An interpretation of the intensities observed in the A1g and B1g spectra is given in terms of the rotational motion of the S8 molecules affecting their contribution to the crystal polarisability.
Étude Théorique de L'effet Raman de Résonance des Molécules Diatomiques et Polyatomiques
Authors: van Labeke D. , Jacon M. , Berjot M. , Bernard L.
Published: May 2005

Dans le cadre de ‘l'approximation de réflexion’, les auteurs proposent une expression analytique du tenseur de diffusion des molécules diatomiques et polyatomiques, valable quelque soit la fréquence excitatrice. L'influence de la symétrie des vibrations sur les intensités des raies Raman de résonance est mise en évidence. L'expression du tenseur Rayleigh permet de justifier la forme gaussienne des courbes d'absorption des molécules polyatomiques. L'importance relative des intensités des différents harmoniques est ensuite étudiée en relation avec le coefficient d'absorption. D'autre part, un développement asymptotique permet de retrouver les résultats des théories antérieures de l'effet Raman de prérésonance

En appendice, on montre enfin comment, à l'aide du formalisme utilisé, on peut déterminer très simplement le tenseur de diffusion Raman de prérésonance des raies fondamentales et harmoniques.
The relation of resonance Raman scattering to resonance fluorescence
Authors: Behringer J.
Published: May 2005

If and only if spontaneous resonance Raman scattering is excited by irradiation upon a single, discrete and non‐degenerate energy level sufficiently distant from other levels can it be interpreted as resonance fiuorescence, i.e. a sequence of two independent one‐photon processes, an absorption and an emission in definte order of succession. This decomposition of the resonance scattering process is independent of the bandwidth of the exciting radiation relative to the widths of the combining levels. These widths however determine quantitatively the temporal decay of the resonance scattering (= resonance fluorescence) probability given explicitly in the paper.
The rotational and rotation‐vibrational Raman spectra of HCN and DCN
Authors: Bendtsen Jørgen , Edwards Howell G. M.
Published: May 2005

The pure rotational and rotation‐vibrational Raman spectra of HCN and DCN have been photographed using a previously described instrument [7]. The molecular constants derived for HCN are in excellent agreement with those obtained from microwave and infrared spectroscopy. Especially, the measurements of the v1 rotation‐vibrational Raman band have confirmed the hitherto indirectly obtained values for the molecular constants of the v1 vibrational state of HCN.
Spectres Raman de Basses Frequences de Cristaux de Derives Benzeniques Paradisubstitues: p‐Br2C6H4, p‐Br2C6D4, p‐BrClC6H4 et p‐ClC6H4. Étude du désordre dans le dérive p‐BrClC6H4
Authors: Le. Calvé N. , Parent S. , Pasquier B. ,   avec la collaboration technique de F. ROMAIN
Published: May 2005

An assignment of the Raman active lattice modes in terms of factor group symmetry species and rotational vibrations is given for paradibromobenzene‐H4 and ‐D4, parabromochlorobenzene and parachloroiodobenzene. The analysis of the Raman spectra of mixed crystals of paradibromobenzene and paradichlorobenzene at 90K with 1 cm−1 resolution and the temperature dependence of the linewidths of the three librations are evidence for the static nature of the disorder in the unsymmetrical derivatives.
Isolating the totally symmetric Raman spectrum of cubic crystals: The A1 spectrum of Cr3B7O13Cl
Authors: Lockwood D. J.
Published: May 2005

It is shown that by measuring the appropriate diagonal and off‐diagonal tensor con ponents of the Raman spectrum of a cubic crystal and then carrying out a simple subtraction process in a computer it is possible to isolate the totally symmetric Raman spectrum from the other components. The method relies on obtaining the data in digital form using automated spectrometry. The technique is applied to cubic Cr3B7O13Cl, whose Raman spectrum is reported here for the first time. The A1 spectrum at 300K comprises four bands at 176, 209, 375 and 657 cm−1 in agreement with group theoretical predictions. In addition, the spectrum contains a prominent wing feature extending to 250 cm−1 that is most likely associated with the ferroelectric phase transition at 263K.
Raman spectra of gases. XV: Hydrazine and hydrazine‐d4
Authors: Durig J. R. , Griffin M. G. , Macnamee R. W.
Published: May 2005

The Raman spectra of gaseous hydrazine and hydrazine‐d4 have been recorded from 40 to 3500 cm−1. For the ‘light’ molecule, strongly polarized lines at 3398, 3329 and 1076 cm−1 have been assigned to the NH antisymmetric stretch, NH symmetric stretch, and NN stretch, respectively. For the hydrazine‐d4 molecule, strongly polarized lines at 2442, 2422, 1031, 930 and 749 cm−1 have been assigned to the ND antisymmetric stretch, ND symmetric stretch, NN stretch, ND2 was and ND2 rock, respectively. The Raman spectra of both solid hydrazine and hydrazine‐d4 have been recorded and the splitting in the intramolecular fundamental region indicates that there are at least four molecules per primitie cell. In the lattice region of the spectra the optical translations and librations are assigned and the number of lattice modes rules out both of the space groups previously proposed for hydrazine from scattering studies.
A study of experimental conditions for obtaining matrix isolation Raman spectra
Authors: Barnes A. J. , Bignall J. C. , Purnell C. J.
Published: May 2005

The effects on the quality of matrix isolation Raman spectra of varying parameters such as the deposition conditions and the substrate metal have been investigated, and the optimum conditions are discussed.
The oriented gas approximation and the lattce vibrations of molecular crystals: Theory and application to perfluorobiphenyl
Authors: Arthur J. W. , Mackenzie G. A.
Published: May 2005

The oriented gas model of the polarisability of a molecular crystal provides a basis for the discussion of its Raman spectrum. This model is examined with a view to deriving information about eigenvectors of the zone centre lattice vibrations in these crystals. The theory of the general case is much simplified by symmetry conditions in certain instances. This is applied to the molecular crystal perfluorobiphenyl, C12F10, of recent interest. For this crystal it is found necessary to extend the theory to include the coupling of internal vibrations with the lattice vibrations. A simple model is found to account for this and the extent of the coupling is thereby estimated.
Vibrational spectra of crystalline HCCN, DCCCN, ClCCCN, BrCCCN, and ICCCN
Authors: Nolin Clément , Weber Jean , Savoie Rodrigue
Published: May 2005

The infrared, far‐infrared, and Raman spectra of crystalline cyanoacetylene and its deutero, chloro, bromo, and iodo derivatives were found to be consistent with the known crystal structures of these compounds. However, no definite evidence could be obtained for the existence of a distinct low‐temperature crystalline modification of iodocyanoacetylene suggested earlier from X‐ray diffraction data.
A correlation between vibronic coupling, adiabatic potential, and Raman scattering: A theoretical background of a proposed rule
Authors: Tsuboi Masamichi , Hirakawa Akiko Y.
Published: May 2005

Using a simple model system, a discussion is given of vibronic coupling between two excited electronic states, |e〉 and |s〉, through a non‐totally symmetric vibration along a normal coordinate Q. It is shown that such a vibronic coupling causes, on the one hand, Raman scattering associated with the vibration along Q, and on the other hand a flattened potential function or a double‐minimum potential function of the lower electronic excited state |e> along Q. The stronger the coupling, the stronger the scattering; and, at the same time, the more severe the flattening (or the greater the separation between the two minima) in the potential function. As an example, the b1g vibration at 917 cm−1 of pyrazine has been fitted with the model.
Raman spectroscopic studies of the effect of some of the gramicidin antibiotics on the phospholipid bilayer
Authors: Faiman R. , Long D. A.
Published: May 2005

The vibrational Raman spectra of some Gramicidin antibiotics and Gramicidin/lipid/water systems are reported. From comparison of these spectra some information can be obtained regarding changes in the tertiary structure of the antibiotic and changes in the hydrocarbon chain conformation within the bilayer on formation of the antibiotic/lipic/water complex.
Intensity distribution in pure rotational Raman spectra of linear molecules in the ground and vibrational II states application to acetylene
Authors: Finsterhölzl H. , Hochenbleicher J. G. , Strey G.
Published: May 2005

The pure rotational Raman spectrum of acetylene has been recorded with argon laser excitation and a resolution of about 0.3 cm−1. For the first time ΔJ = 1 transitions in the excited II states are clearly resolved up to J = 9. Formulae for the intensity distribution in rotational Raman spectra of linear molecules in the ground and vibrational II states have been derived including the effect of I‐type doubling. After a qualitative discussion these formulae are applied to a quantitative analysis of the acetylene spectrum.
Absolute Raman intensities of liquids
Authors: Abe N. , Wakayama M. , Ito M.
Published: May 2005

The absolute intensities of the 802 cm−1 Raman line of liquid cyclohexane at 514.5 and 337.1 nm excitations were determined by applying the local field correction theory to corresponding absolute intensities of cyclohexane vapour. By using this Raman line as an external intensity standard, the absolute Raman intensities of the 992 cm−1 line of benzene and the 666 and 762 cm−1 lines of chloroform were measured in the liquid phase. The gaseous absolute intensities were also measured for some molecules including benzene and chloroform and comparisons between the gas and liquid phase Raman intensities were made.
Raman and infrared spectra of crystalline [UO2(NH2O)2(H2O)2]·H2O
Authors: Scheuermann W. , Van Tets A.
Published: May 2005

Raman spectra of a single crystal were recorded at 292 K in addition to spectra at 292 and 17 K of undeuterated and partly deuterated powder. Infrared spectra of these compounds in KBr discs were recorded in the temperature range 17–360 K. Furthermore far infrared spectra of the undeuterated and partly deuterated compound in nujol mulls were recorded at 292 and 85 K. The stretch frequencies of the uranyl group which in this compound appears to be linear and symmetric, were observed at extremly low values, viz. νs at 783 cm−1 (R) and νas at c. 850 cm−1 (i.r.). The spectroscopic evidence confirmed the strong degree of hydrogen bonding which involves the uranyl group and all hydrogen atoms, even those of the hydroxylamino group. A small but complete correlation field splitting was observed especially in the case of the νs (NO) vibration at 919 (B1g), 921 (Ag), 923 (B2g) and 925 cm−1 (B3g) in agreement with the predictions of a factor‐group analysis.
Etude Vibrationnelle par Spectrométrie Raman en Phase Vapeur du Benzène d3. Détermination des Constantes de Coriolis des Espéces E′ et E″
Authors: Chapput André , Guy Fleury Bernard Roussel
Published: May 2005

The gas phase Raman spectrum of benzene d3 has been recorded at medium resolution. The band contours of E′ and E″ degenerate species have been observed and their computer simulation has allowed the determination of the Coriolis constant values. Five fundamental bands of E′ symmetry and two of E″ symmetry have been computed. This analysis has given the values of ζ6, ζ8, ζ9, ζ19, ζ20 (E′), ζ10, ζ16, (E″). ζ18 (E″) has been calculated from the zeta sum rules.
Low temperature Raman measurements of carbon monoxide adsorbed on nickel at high pressures
Authors: Krasser W. , Ranade A. , Koglin E.
Published: May 2005

The Raman spectra of carbon monoxide adsorbed on Raney nickel and on supported SiO2 are measured at high pressures and low temperatures with a rotating cell. In addition to the vibrational bands of adsorbed Ni(CO)4, we find three band systems of CO stretching vibrations at high wavenumbers and several bands at low wavenumbers. The CO stretching vibrations agree with infrared spectra.
Vibrational spectra and normal mode calculations of benzoic acid single crystals
Authors: Klausberger G. , Furić K. , Colombo L.
Published: May 2005

Raman and infrared spectroscopic studies of benzoic acid dimers and crystals have been made. Molecular and crystal normal modes have been calculated. An assignment of the observed spectra has been proposed and some specific modes discussed.
Raman intensities: Transferability of electrooptical parameters
Authors: Gussoni Mariangela , Abbate Sergio , Zerbi Giuseppe
Published: May 2005

In this paper the electrooptical theory of valence for the study of Raman intensities is reanalysed and extended to the case of non‐cylindrical tensors. The advantages of this theory with respect to other methods are described. The transferability of electrooptical parameters to other molecules (isotopic derivatives or chemically similar molecules) is discussed and some examples (methane and cyclohexane) are presented.
Polymorphism in zinc chloride—a Raman spectral study
Authors: James David W. , Parry Robyn M. , Leong W. H.
Published: May 2005

The Raman spectra of the three reported phases of zinc chloride are reported. In addition, a new high temperature phase is spectroscopically identified. The spectrum of phase IV is completely assigned. The spectrum of phase II indicates spatial disorder, while those of phases I and III are compatible with completely ordered structures.
Absolute Raman intensities of cyanogen
Authors: Warsop P. A. , Montero S.
Published: May 2005

The absolute Raman intensities as well as the depolarization ratios of the vibrational modes ν1, ν2, ν4and 2ν4of cyanogen in the gas phase are reported. These data are interpreted on the basis of the bond polarizability theory. From this interpretation it seems reasonable to assign localized CN bond polarizabilities to the cyanogen molecule.