bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of multiple integrins and extracellular matrix components by C6 glioma cells
Authors: Malek‐Hedayat S. , Rome L. H.
Published: May 2005

We have investigated the expression of integrins in C6 glioma, a chemically‐induced glial tumor cell line from rat brain. Immunochemical analysis revealed that C6 cells express sets of integrin receptor complexes which immunologically and electrophoretically are indistinguishable from those expressed hy normal rat skin fibroblasts. These include the well characterized fibronectin (α5β1) and the multi‐specific laminin, collagen and fibronectin (α3β1) receptors. Assay of cell adhesion indicated that C6 cells adhere fibronectin‐coated surfaces or matrix deposited by the c6 glioma cells (CGM) in an RGD‐ and divalent cation‐dependent fashion. However, anti‐fibronectin antibodies, which are able to inhibit fibroblast adhesion to fibronectin, did not inhibit adhesion of the C6 cells to fibronectin or CGM. This may reflect differences in functional properties and/or distribution patterns of integrins in C6 cells and normal fibroblasts.
Hippocampal NCAM180 transiently increases sialylation during the acquisition and consolidation of a passive avoidance response in the adult rat
Authors: Doyle E. , Nolan P. M. , Bell R. , Regan C. M.
Published: May 2005

Synaptic connectivity change is a consistent anatomical feature of memory formation and the possibility that this is mediated by a replay of neurodevelopmental events has been investigated by measuring change in neural cell adhesion molecule sialylalion state during the acquisition and consolidation of a passive avoidance response in the adult rat. The avoidance response was always generated after two to three trials and the animals remained on the platform for the criterion time of 5 min. In all cases training was complete within 5–8 min. Change in sialylation state was monitored following intrayentricuiar infusion of the 3H‐ManNAc Precursor at 4 hr prior to the reference point. No task‐specific change in general glycoconjugate sialylation was apparent in hippocampal P2 pellets at increasing times following training. Increased sialylation state was observed only in neural cell adhesion molecule (NCAM) immunoprecipitates of hippocampal membrane fractions at 12 and 24 hr after training. Change in hippocampal sialylation state could not be attributed to an increased accumulation of NCAM as detected by an immunoabsorbent assay. Immunoblotting of antibody precipitated NCAM demonstrated the 3H‐ManNAc to be incorporated into the synapse‐specific, 180 kDa isoform of NCAM and a novel 210 kDa isoform. Immunoprccipitation and immunoblotting procedures with an antibody specific for a2‐8‐polysialic acid showed the 180 and 210 kDa isoforms to be polysialylated. The role of NCAM180 sialylation as a mechanism for synapse selection in information storage is discussed.
Distribution of calcium‐activated neutral protease inhibitor in the central nervous system of the rat
Authors: Kamakura K. , Ishiura S. , Imajoh S. , Nagata N. , Sugita H.
Published: May 2005

The ubiquitous existence of calcium‐activated neutral protease (CANP, calpain), an enzyme whose activity is regulated by calcium ions and a specific endogenous CANP inhibitor (calpastatin), is well known. Although there has been much investigation concerning the distribution and role of CANP, investigations of the distribution of the CANP inhibitor using immunohistochemical techniques are rare.

We made antiserum against a 40K fragment of cDNA corresponding to two C‐terminal repeats of rat liver CANP inhibitor expressed in Escherichia coli. Using this antiserum, we examined the distribution of CANP inhibitor in the rat central nervous system by the ABC technique and compared it with the distribution of CANP. Neurons and glias were stained, with the cytosol stained diffusely and the cell membranes stained clearly and strongly. Axons and myelin were stained faintly, but nuclei and vessels were not stained. The distribution of CANP inhibitor was thus found to be similar to that of CANP.
Expression of platelet‐derived growth factor (PDGF) and PDGF receptor genes in the developing rat brain
Authors: Reddy U. R. , Pleasure D.
Published: May 2005

Steady‐state levels of rat central nervous system (CNS) platelet‐derived growth factor (PDGF) A‐ and B‐chain mRNAs were measured by a polymerase chain reaction method employing a synthetic gene internal standard, and the rates of transcription of PDGF A‐ and B‐chain genes in CNS were estimated by a nuclear runoff assay. The abundance of PDGF B‐chain mRNA was an order of magnitude below that of PDGF A‐chain mRNA, while the rate of PDGF B‐chain transcription was only slightly below that for the PDGF A‐chain gene, indicating that the half‐life of PDGF B‐chain in CNS is shorter than that of PDGF A‐chain mRNA. No developmental alterations in expression of the PDGF A‐ and B‐chain genes were detected. By contrast, Northern blots showed that steady‐state levels of mRNAs encoding the two PDGF receptor proteins, α and β, were markedly higher in embryonic day 15 and postnatal day 6 rat brains than in later life. These results suggest that the actions of PDGF on the brain in vivo are regulated not at the level of PDGF A and B‐chain gene expression, but rather by changes in the level of expression of PDGF α‐ and β‐receptor genes.
Retinoic acid‐regulated expression of proteolipid protein and myelin‐associated glycoprotein genes in C6 glioma cells
Authors: Zhu W. , Kanoh M. , Ye P. , Laszkiewicz I. , Royland J. E. , Wiggins R. C. , Konat G.
Published: May 2005

The effect of retinoic acid (RA) on the expression of myelin‐specific genes, i.e., proteolipid protein (PLP) and myelin‐associated glycoprotein (MAG) in rat glioma C6 cells, was analyzed by Northern blot hybridization. RA‐treatment increased the steady‐state level of the PLP‐specific messages within one day alter RA administration and the upregulation reached a maximum on the third day. Concomitantly, the expression of MAG‐specific messages in the RA‐treated C6 cells dropped below the detectability limit. The expression of the PLP gene was directly related to the RA concentration increasing to approximately 44‐ fold over the control (untreated cells) level at 10−6 RA. The stimulatory effect was vitiated by cyclohex‐imide indicating the involvement of intermediate genes in the PLP gene activation. The total cellular RNA content and the level of cyclophilin mRNA was not changed by the RA‐treatment. The present data indicate that RA can be a potent modulator of the myelin‐specific gene expression. Furthermore, the reciprocal response of PLP versus MAG genes to RA demonstrates that these two genes utilize different regulatory mechanisms.
β‐Amyloid precursor protein of Alzheimer's disease in cultured bovine oligodendrocytes
Authors: Mizuguchi M. , Ikeda K. , Kim Seung U.
Published: May 2005

The production of β‐amyloid precursor protein (βAPP) in cultured oligodendrocytes isolated from adult bovine brains was examined by immunohistochemistry and immunoblotting. Immunostaining of oligodendrocytes with antibodies specific for the carboxy terminus of βAPP demonstrated positive immunoreactivity of oligodendroglial cytoplasm. Immunoblot analysis of cellular extracts detected two distinct bands with estimated molecular weight of 118 and 105 kDa. The amount of these βAPP subspecies increased considerably in response to their attachment to the poly‐L‐Iysine substratum. © 1992 Wiley‐Liss, Inc.
Exogenous gangliosides modulate calcium fluxes in cultured neuronal cells
Authors: Guérold B. , Massarelli R. , Forster V. , Freysz L. , Dreyfus H.
Published: May 2005

Previous work from this and other laboratories has shown that the neuritogenic effect due to exogenous gangliosides on primary neurons in culture is accompanied by several morphological and biochemical modifications. The present results indicate that the treatment of these neurons with gangliosides, under the experimental conditions which are known to produce a sprouting effect, inhibited the influx of 45Ca2+ and increased the release of 45Ca2+ from the cells. No significant differences were noted using concentrations of gangliosides (10−8‐10−5 M) either below or above the critical micellar concentrations. No apparent specificity was observed among various species of individual sialocompounds (GM1, GD1a). Moreover the presence or absence of fetal calf serum in the culture medium influenced the levels of 45Ca2+ fluxes. This study confirms the hypothesis that gangliosides may be considered as Ca2+ flux modulators in neuronal cells. © 1992 Wiley‐Liss, Inc.
Taurine release and swelling of cerebral cortex slices from adult and developing mice in media of different ionic compositions
Authors: Oja S. S. , Saransaari P.
Published: May 2005

The release of preloaded radiolabeled taurine was studied in superfused cerebral cortex slices obtained from adult and 3‐day‐old mice in media of varying ionic composition. Our aim was to establish whether the release of taurine from slices evokable by high concentrations of K+ could be attributed solely to cell volume changes or whether it results directly from depolarization of cell membranes. In both age groups hypoosmotic media enhanced the release of taurine. The enhancement was greater in 3‐day‐old than in adult mice. The K+‐evoked release of taurine was likewise greater in slices from 3‐day‐old mice than in slices from adult mice. The K+ stimulation was totally preserved in adult mice and partially preserved in 3‐day‐old mice when the slices were superfused with Cl−‐free media, with media in which the K+ × Cl− ionic product was kept constant and with hyperosmotic high‐K+ media. The results were practically the same when the permeant anion acetate and the impermeant anion gluconate were used to replace the Cl− deficit. The unstimulated release of preloaded taurine was greatly enhanced in Cl−‐free media in both age groups. There obtained no statistically significant correlation between the intracellular swelling of slices and the magnitude of taurine release under the present different experimental conditions in either age group. The results show that the K+‐evoked release of taurine from superfused cerebral cortex slices cannot be solely attributed to depolarization‐induced cell swelling. At least a part of the release results directly from membrane depolarization which besides exocytosis apparently also enhances the carrier‐mediated release of taurine and inhibits the reuptake of taurine liberated from intracellular compartments. © 1992 Wiley‐Liss, Inc.
Neurotrophin gene expression by cell lines derived from human gliomas
Authors: Hamel W. , Westphal M. , Szőnyi É. , Escandón E. , Nikolics K.
Published: May 2005

The expression of neurotrophin (NGF, BDNF, and NT‐3) mRNAs in 24 cell lines derived from human malignant gliomas was studied by Northern analysis. Widespread expression of neurotrophin genes was found with BDNF being the most abundantly expressed. Nearly all cell lines expressed BDNF, and about two‐thirds of the cell lines expressed NGF and NT‐3. Half of the cell lines analyzed expressed all three neurotrophins. Secretion of NGF into the medium of several cell lines could be detected by ELISA and a PC12 neurite outgrowth assay. Immuno‐ and bioactive NGF was isolated from conditioned medium of one cell line. No evidence of expression of the neurotrophin receptors trk and trkB by Northern analysis was found. Receptor crosslinking with radiolabeled cognate ligands failed to detect functional receptors in all but one cell line. In this cell line a receptor complex for BDNF was found that corresponded to truncated trkB receptors that lack the signal transducing tyrosine kinase domain. Neurotrophins did not stimulate mitosis of the glioma cultures. The findings suggest that production of neurotrophins by glioma cells is a general phenomenon, although neurotrophins made by gliomas lacking their receptors may not play an autocrine but rather a paracrine role. © 1993 Wiley‐Liss, Inc.
Modulation of voltage‐activated Ca currents by pain‐inducing agents in a dorsal root ganglion neuronal line, F‐11
Authors: Kusano K. , Gainer H.
Published: May 2005

Whole cell currents evoked by pain‐inducing agents—bradykinin (Bk), capsaicin (Cap), and reciniferatoxin (RTX), and their modulation of voltage‐activated Ca currents were examined in F‐11 cells using a patch electrode voltage clamp technique. Most F‐11 cells generated action potentials under current clamp if their membrane potentials were held sufficiently negative. Average peak inward Na current (INa) was 100 μA/cm2 and the INa was abolished by 10−6 M tetrodotoxin. At least two types of Ca currents could be clearly distinguished on the basis of voltage dependency and kinetics; a low threshold transient ICa(t) and a high threshold sustained ICa(I). In addition, another high threshold transient Ca current, presumably ICa(n), was observed. About 30% of the cells produced inward current for these pain‐inducing agents, when activated at the membrane holding potential of −70 mV. In some F‐11 cells, the amplitude of action potential was observed to increase during 10−6 M Cap‐induced depolarization. Both low and high threshold Ca currents were reduced by 10−6 M Bk in the majority of the cells. Similarly, both 10−6 M Cap and 10−9 M RTX reduced these Ca currents. However, a considerable number of cells showed an initial enhancement followed by reduction in the amplitude of these Ca currents. With higher concentrations of these ligands, all Ca currents were suppressed. Such modulation of voltage‐activated Ca currents by pain‐inducing agents occurred in both the presence and absence of apparent receptor‐activated current flows in the cells. In pertussis toxin (PTX)‐treated cells, the inhibitory modulation of Ca currents by pain‐inducing agents was suppressed. In contrast, in cholera toxin (CTX)‐treated cells, this inhibitory modulation appeared to be enhanced. These data indicate that the inhibitory modulation of Ca channel currents by Cap and RTX, similarly to that of Bk, involves a PTX‐sensitive inhibitory G protein (Gi). © 1993 Wiley‐Liss, Inc.
Insulin‐like growth factor‐I (IGF‐I) production by astroglial cells: Regulation and importance for epidermal growth factor‐induced cell replication
Authors: Chernausek S. D.
Published: May 2005

The insulin‐like growth factor are postulated to play a role during brain development. Because they are believed to act in a paracrine/autocrine manner, the production of insulin‐like growth factor‐I (IGF‐I) by cultured astroglial cells was examined. Quantities of IGF‐I in conditioned media were determined by RIA after separation of IGFs from IGF‐binding proteins by high‐pressure liquid chromatography. Astrocytes from 1‐day‐old rats and the rat glioma cell line (C6) both secreted 7.5‐kDa IGF‐I. A peak of immunoreactivity with an apparent mol wt of 12,000 was additionally present in media conditioned by C6 cells. Exposure to epidermal growth factor (EGF) increased media content of immunocreactive IGF‐I slightly (60%) in C6 cells but more than 2‐fold in normal astrocytes. Fibroblast growth factor also increased the amount of IGF‐I contained in media conditioned by normal astrocytes. To determine whether the secreted IGF‐I was biologically active, media IGFs were immunoneutralized with a monoclonal antibody (Sm 1.25). In the presence of the antibody, EGF‐stimulated astrocyte replication was blocked. These data indicate that IGF‐I secretion by rodent astrocytes is stimulated by factors thought to be important for brain growth and development and that the IGFs are likely intimate participants in EGF‐induced astrocyte growth. © 1993 Wiley‐Liss, Inc.
Cell volume regulation in cultured cerebellar granule neurons
Authors: Pasantes‐Morales H. , Maar T. E. , Morán J.
Published: May 2005

Cultured rat cerebellar granule neurons exposed to solutions of reduced osmolarity, responded initially by swelling followed by a regulatory volume decrease (RVD) which is completed within 15 min. Increasing external osmolarity lead to cell shrinking but no evidence of volume regulation was observed within 1 hr. Replacing Na+ by choline did not affect RVD whereas N‐methyl‐D‐glucamine accelerated the volume recovery and K+ suppressed it completely. The blockade of RVD in high extracellular K+ was only observed when chloride and nitrate but not sulfate or gluconate were the accompanying anions. Replacing intracellular Cl−, by long incubations with gluconate, markedly inhibited RVD. Removal of extracellular Ca2+ or addition of dantrolene which blocks Ca2+ released from intracellular stores had no effect on RVD. Increasing extracellular taurine prevented RVD. These results indicate that membrane permeability to K+, Cl−, and taurine is increased by hyposmolarity and suggest the involvement of these molecules in RVD in granule neurons. © 1993 Wiley‐Liss, Inc.
Localization of neprilysin (EC 3.4.24.11) mRNA in rat brain by in situ hybridization
Authors: Gaudoux F. , Boileau G. , Crine P.
Published: May 2005

The distribution of the messenger RNA (mRNA) coding for neprilysin (EC 3.4.24.11) has been studied by in situ hybridization in the adult rat brain. A markedly heterogeneous distribution among various brain regions was found. A strong signal was observed in the glomerular layer of the olfactory bulb, the olfactory tubercle, the caudate putamen, the habenular, anterior pretectal, interpeduncular, red, dorso tegmental, pontine, and vestibular nuclei, the mammillary bodies, the Purkinje cells, and the choroid plexus of the fourth ventricle. A large number of areas such as the cortex, the dentate gyrus, the hippocampus, the medial terminal nucleus of the accessory tract, the accumbens and the arcuate nuclei, the superior and inferior colliculi, and a few regions in the thalamus at the mesencephalic level exhibited a moderate or low signal of hybridization. The majority of these regions are also known to contain the neprilysin protein. On the other hand, the globus pallidus, the substantia nigra, and the central gray matter, which show a high or a moderate amount of neprilysin, did not contain any neprilysin mRNA. Comparison of the regional distribution of neprilysin mRNA with that of its translation product provides insight into neprilysin neuronal pathways in the central nervous system. © 1993 Wiley‐Liss, Inc.
Transient increases in neuropeptide Y‐like immunoreactivity in dentate hilar neurons following fimbria/fornix transection
Authors: Bayer L. E. , Milner Teresa A.
Published: May 2005

Neurons containing neuropeptide Y (NPY) are numerous in those hippocampal regions that receive septal and monoaminergic afferents. To assess the role of these afferents in the expression of NPY in hippocampal neurons, the number and distribution of perikarya with NPY‐like immunoreactivity (NPY‐LI) was examined quantitatively in the dentate gyrus of adult male rats following unilateral transection of the right fimbria/fornix. In unlesioned rats, immunoperoxidase labeling for the antibody to NPY was detected mostly in fibers and only a few perikarya in the dentate gyrus. Following fornix transections, the number of detectable NPY‐containing neurons in the hilus of the dentate gyrus ipsilateral to the lesion increased at 3 days post‐lesion (dpl), peaked at 6 and 9 dpl, then returned to basal levels at 14 dpl and 1 and 6 months post‐lesion. This elevation followed a rostral to caudal gradient. No apparent changes were found in the distribution of NPY‐labeled neurons at any post‐lesion interval studied. Moreover, no significant changes at any of the post‐lesion times were found in the number or distribution of neurons with NPY‐LI in the hilus of sham lesioned (i.e., ablations of the cortex and anterior hippocampal formation sparing the fornix) rats. The observed increases in the number of hippocampal neurons containing detectable NPY suggests that the cellular levels of this peptide are dependent on pathways travelling through the fornix. The rapid and transient increases in NPY are not due exclusively to changes in cholinergic pathways but may involve changes in other pathways within the fornix or even indirect neurotrophic effects. © 1993 Wiley‐Liss, Inc.
Interleukin‐4 and ‐5 as modulators of nerve growth factor synthesis/secretion in astrocytes
Authors: Awatsuji H. , Furukawa Y. , Hirota M. , Murakami Y. , Nii S. , Furukawa S. , Hayashi K.
Published: May 2005

To examine the regulation of nerve growth factor (NGF) gene expression with respect to neural trauma, we examined the effects of T cell‐derived lymphokines on NGF synthesis/secretion in cultured mouse astrocytes. Interleukin (IL)‐4 and IL‐5 significantly increased the amount of NGF secreted by astrocytes, whereas IL‐2, IL‐3, and IL‐6 had no significant effect. IL‐4 and IL‐5 produced marked increases in NGF mRNA levels in astrocytes as demonstrated by the reverse transcription‐polymerase chain reaction (RT‐PCR) method. The effect of IL‐4 and IL‐5 was greater in quiescent astrocytes than in growing cells. Neither increase in thymidine incorporation nor any morphological change was observed during the treatment with IL‐4 and IL‐5. The stimulatory effect of IL‐4 and IL‐5 on NGF synthesis was completely inhibited by the addition of anti‐IL‐4 monoclonal antibody and anti‐IL‐5 monoclonal antibody, respectively. The results indicate that IL‐4 and IL‐5 specifically trigger a cascade of events to regulate NGF synthesis in astrocytes, independent of cell growth. © 1993 Wiley‐Liss, Inc.
Different distributions of GAD65 and GAD67 mRNAS suggest that the two glutamate decarboxylases play distinctive functional roles
Authors: Feldblum S. , Erlander M. G. , Tobin A. J.
Published: May 2005

Two genes encode two forms of glutamate decarboxylase, GAD65 and GAD67. Because the two GADs differ in subcellular distribution and interactions with the cofactor pyridoxal phosphate, the two enzymes may play different roles in gamma‐aminobutyric acid (GABA) production. In this study we have used in situ hybridization to compare the regional and cellular distributions of the two GAD mRNAs in rat brain. Both GAD mRNAs are abundant in olfactory bulb, olfactory tubercle, zona incerta, reticular nucleus of the thalamus, oculomotor nuclei, and pontine tegmental area. GAD65 mRNA is more abundant in several structures of the visual system, including the lateral geniculate nuclei, superior colliculi, and olivary pretectal nucleus, as well as in several hypothalamic and pontine nuclei. In contrast, GAD67 mRNA is more abundant in neocortex, the granular layer of olfactory bulb, lateral and medial septum, globus pallidus, inferior colliculi, and cerebellar cortex. Both GAD mRNAs are present in interneurons as well as in projection neurons, and both are present in neurons with different types of synapses, including dendrodendiritic, axosomatic, and axodendritic synapses. GAD65 mRNA predominates in the visual and the neuroendocrine systems, which are more subject to phasic changes, while GAD67 is present at relatively higher concentrations in many tonically active neurons. GAD65 and GAD67 together may provide more flexibility in the regulation of GABA synthesis than either could alone. © 1993 Wiley‐Liss, Inc.
Increased PO glycoprotein gene expression in primary and transfected rat Schwann cells after treatment with axolemma‐enriched fraction
Authors: Knight R. M. , Fossom L. H. , Neuberger T. J. , Attema B. L. , Tennekoon G. , Bharucha V. , DeVries G. H.
Published: May 2005

To elucidate the role of axonal plasma membrane factors in the differentiation of Schwann cells, we investigated the effect of an axolemma‐enriched fraction (AEF) isolated from myelinated CNS tissue on the expression of PO glycoprotein, the major glycoprotein in peripheral myelin, in primary rat Schwann cells (PSC) isolated from sciatic nerve, as well as in a transfected rat Schwann cell line (TSC). AEF increased PO‐mRNA levels in PSC and TSC in a concentration‐dependent manner, producing a maximal induction of nearly twofold after 48 hr of treatment. A similar induction of PO mRNA was elicited in TSC by the cAMP‐activating agents 8‐bromo‐cAMP and forskolin, which have been shown to induce myelin proteins in PSC. In addition to inducing PO mRNA, AEF and forskolin also increased the amount of PO protein in TSC, as indicated by increased PO‐immunoreactive staining. However, in TSC, axolemma caused no increase in expression of CAT linked to a PO promoter while forskolin caused a marked increase in the expression from the PO promoter. These results suggest that AEF, in contrast to forskolin, does not regulate PO‐mRNA expression at the level of transcriptional activity. These in vitro systems may be useful for the study of axolemmal factors that in‐duce Schwann cell differentiation. © 1993 Wiley‐Liss, Inc.
Production and characterization of monoclonal antibodies to the extracellular domain of P0
Authors: Archelos J. J. , Roggenbuck K. , Scheider‐Schaulies J. , Linington C. , Toyka K. V. , Hartung H.‐P.
Published: May 2005

Seven monoclonal antibodies were raised against the immunoglobulin‐like extracellular domain of P0 (P0‐ED), the major protein of peripheral nervous system myelin. Mice were immunized with purified recombinant rat P0‐ED. After fusion, 7 clones (P01–P07) recognizing either recombinant, rat, mouse, or hu‐man P0‐ED were selected by ELISA and were characterized by Western blot, immunohistochemistry, and a competition assay. Antibodies belonged to the lgG or lgM class, and P04–P07, reacted with PO in fresh‐frozen and paraffin‐embedded sections of human or rat peripheral nerve, but not with myelin proteins of the central nervous system of either species. Epitope specificity of the antibodies was determined by a competition enzymelinked immunosorbent assay (ELISA) and a direct ELISA using short synthetic peptides spanning the entire extracellular domain of P0. These assays showed that P01 and P02 exhibiting the same reaction pattern in Western blot and immunohistochemistry reacted with different distant epitopes of P0. Furthermore, the monoclonal antibodies P05 and P06 recognized 2 different epitopes in close proximity within the neuritogenic extracellular sequence of P0. This panel of monoclonal antibodies, each binding to a different epitope of the extracellular domain of P0, will be useful for in vitro and in vivo studies designed to explore the role of PO during myelination and in demyelinating dis‐eases of the peripheral nervous system. © 1993 Wiley‐Liss, Inc.
Infusion of iron into the rat substantia nigra: Nigral pathology and dose‐dependent loss of striatal dopaminergic markers
Authors: Sengstock G. J. , Olanow C. W. , Menzies R. A. , Dunn A. J. , Arendash G. W.
Published: May 2005

Iron has recently been suggested to contribute to the pathogenesis of Parkinson's disease (PD) because of the finding of increased iron levels in the substantia nigra pars compacta (SNc) above those of control patients. Iron is capable of catalyzing numerous reactions which could lead to free radical formation and oxidative damage to DNA, proteins, lipid membranes, and other biological molecules. Neurodegeneration in the SNc of the PD brain may be a consequence of increased iron, which promotes these cytotoxic reactions. To test whether excess iron could play a causative role in the degeneration of nigral neurons, we infused 1.25–6.3 mnol of iron into the rat substantia nigra (SN) unilaterally utilizing two different infusion protocols. All infusates were isosmotic and pH‐balanced in a citrate‐bicarbonate vehicle. Animals were decapitated at either 1 or 2 months postinfusion. Striatal tissue was assayed for biogenic amines by HPLC and the remaining brainstem was processed for histological analysis. Ironstained coronal sections revealed (1) no left/right staining difference with vehicle infusion, (2) a dose‐dependent iron accumulation in the infused SN that was restricted to the zona compacta and dorsal‐most zona reticularis when the lowest iron concentration was infused, and (3) a dose‐dependent reduction in SN volume. Thionine‐stained sections revealed neuronal loss and accompanying reactive gliosis within an area that corresponded closely to that of increased iron staining. These degenerative changes were more extensive in animals infused via a side‐by side vs. a sequential protocol. Neurochemically, there was a highly significant correlation between the amount of iron infused intranigrally and magnitude of reductions in striatal DA, DOPAC, and HVA within the ipsilateral striatum. These data indicate that iron infusion into the SN can cause degenerative changes within the SN and that these changes can be restricted to the SNc region when low amounts of iron are infused. The data further support the hypothesis that iron‐induced degeneration may contribute to the pathogenesis of PD. © 1993 Wiley‐Liss, Inc.
Vibration spectra and polymorphism of chiral compounds
Authors: Mathieu J. P.
Published: May 2005

The study of the low frequency Raman and infrared spectra of tartaric derivatives and of coordination compounds of Co, Rh and Ir shows that there are definite differences between the external vibration frequencies of the racemic and the active crystalline forms. This can be used as evidence for the spontaneous splitting of a chiral compound.
A spectroscopic study of vibrations in crystalline compounds [Me(NH3)6] X2
Authors: Grzybek T. , Janik J. M. , Kulczycki A. , Pytasz G. , Janik J. A. , Ściesiński J. , Ściesińska E.
Published: May 2005

Infra‐red and Raman spectra of [Me(NH3)6]X2 crystals were measured for Me  Co, Ni and X  Cl, Br, I. BF4, ClO4, PF6. The bands obtained were interpreted as being connected with vibrations of the [Me(NH3)6] octahedron. A far infra‐red band at ca. 80 cm−1 was interpreted as an IR active lattice mode. A lattice dynamics model based on electrostatic interactions between point ions was developed. A low frequency Raman active lattice mode was theoretically foreseen by this model.
Raman scattering in yellow and red mecury iodides
Authors: Nakashima Shinichi , Mishima Hiroaki , Mitsuishi Akiyoshi
Published: May 2005

The first‐order Raman spectra of layer compounds HgI2 in both red and yellow phases have been measured in the temperature region from −200°C to 150°C. A sudden change in the spectra was observed at the temperature of the phase change. Three strong Raman bands were observed in each phase. An interpretation of the spectra has been carried out on the basis of the group theoretical analysis for the layer symmetry and the crystal symmetry. The strength of the interlayer force in each phase has been estimated from the experiments.
Absolute intensity ratios of Raman lines of benzene and ethylene derivatives with 5145 Å and 3371 Å excitation
Authors: Udagawa Y. , Mikami N. , Kaya K. , Ito M.
Published: May 2005

Absolute Raman intensities of benzene and ethylene derivatives were measured in the vapour phase with 5145 Å and 3371 Å excitation. Intensity increase of benzene 992 cm−1 band, which has been frequently used as an intensity standard, was found to be much smaller than expected. The observed intensity increases of ethylene derivatives nicely agree with the theory by assuming the contributing virtual states are the lowest allowed 1π, π* state.
Brewster angle Raman scattering from transparent crystals
Authors: Dawson Peter
Published: May 2005

Crystals of poor optical quality resist attempts to obtain polarised Raman spectra and produce high background levels of scattered radiation which make low frequency studies impossible. It is shown that the Brewster angle scattering technique, usually reserved for opaque or nearly opaque materials, can overcome these obstacles and yield spectra of acceptable signal‐to‐noise, low background radiation levels and with good polarisation data.
The selection rules and the transition moment for rotation‐vibrational transitions in axial molecules
Authors: Hegelund Flemming , Rasmussen Finn , Brodersen Svend
Published: May 2005

The spectroscopic selection rules for infrared and Raman transition between rotation‐vibrational states of axial molecules are formulated in terms of the appropriate quantum numbers and taking into account any rotation‐vibrational interaction. On this basis, expressions for the transition moment have been derived. The effect of all the degeneracies present in the field‐free case is included in these expressions.

A special treatment is given of the diagonal approximation to the rotation‐vibrational interaction problem and in this case the expressions for the transition moment can be reduced and the selection rules expressed in terms of the usual quantum numbers.
Infrared and Raman spectra of the spinel ZnGa2O4
Authors: Van Gorkom G. G. P. , Haanstra J. H. , v. d. Boom H.
Published: May 2005

A study of the infrared and Raman spectra of single crystals and powders of ZnGa2O4 yields the following k = 0 phonon frequencies: 175 cm−1 (T1u), 328 cm−1 (T1u), 420 cm−1 (T1u), 570 cm−1 (T1u), 467 cm−1 (T2g), 611 cm−1 (T2g), 638 cm −1 (Eg) and 714 cm−1 (A1g).

The results are compared with the frequencies of the vibronic sidebands of the Cr3+ R line emission as observed in ZnGa2O4: Cr3+. It is found that the strogest vibronics of the R lines are due to coupling of the Cr3+ electrons with the T1u modes of the ZnGa2O4 lattice, especially with the two higher frequency T1u modes.
A Raman study of H2O2 and D2O2 vapor
Authors: Giguére P. A. , Srinivasan T. K. K.
Published: May 2005

The Raman spectrum of hydrogen peroxide in the vapor phase has been measured for the first time by means of an Ar+ laser source. Three parallel bands were found at 3607 (v1), 1393.5 (v2), and 863.5 (v3) cm−1, with relative intensities of about 10:3:12. In deuterium peroxide the corresponding frequencies are 2668.5, 1028.5, and 867.0 cm−1, and the relative intensities, 20:3:12. Thus, the OO stretching frequency is appreciably lower in the free molecule than in condensed phases (880 cm−1). The shift corresponds to a bond shortening of about 0.01 Å in the latter, in agreement with X‐ray and neutron diffraction data for various crystals. The slight shift to higher frequency of the OO vibration in D2O2 is due primarily to coupling with the OD bending, as indicated by a normal coordinate analysis.
Vapour phase Raman and infrared spectra of, and vibrational assignments for sulphuryl fluoride; application of the trace scattering method for the assignment of totally symmetric vibrations
Authors: Sportouch S. , Clark R. J. H. , Gaufrès R.
Published: May 2005

The Raman and infrared spectra of sulphuryl fluoride in the vapour phase have been reinvestigated. A new assignment of the a1 OSO bending vibration is proposed on the basis of accurate measurements of trace scattering in overlapping bands in the 550 cm−1 region. The band previously reported at 388 cm−1 in the Raman spectrum of the gas is shown in fact to lie at 384 cm−1 and thus to be virtually coincident with the a1 FSF bending vibration (at 384.5 cm−1 in the infrared) and it is concluded that the a2 torsion (infrared inactive) still remains undetected in the Raman spectrum.
Spectroscopic studies of Lewis acid‐base complexes. III: Vibrational frequencies, assignments and normal coordinate analyses for isotopic varieties of phosphine borane and trifluorophosphine borane
Authors: Taylor R. C. , Rudolph R. W. , Wyma R. J. , Dunning V. D.
Published: May 2005

Vibrational spectra of the two Lewis complexes, phosphine borane, PH3BH3, and trifluoro‐phosphine borane, PF3BH3, have been investigated for several isotopic species preserving C3v symmetry. New assignments are proposed and substantiated by normal coordinate analyses formulated in the compliance constant basis.
Excitation of the coherent optical phonons of Eg‐type in calcite by means of the active spectroscopy method
Authors: Akhmanov S. A. , Koroteev N. I. , Kholodnykh A. I.
Published: May 2005

The results of an experimental investigation of the twofold degenerate vibrations in calcite (Eg‐type; phonon frequency ΩE/2πc = 721 cm−1) by means of active spectroscopy method, including a new modification of this method are reported. Beating of a biharmonic pump consisting of Nd: YAG laser radiation and tunable (narrow band or broad band) radiation from an optical parametric oscillator (OPO) was used to excite coherent optical phonons above the thermal level. Scattering of the second harmonic of Nd: YAG was used to detect these coherent vibrations. The components of the Raman scattering tensor for Eg phonons and the absolute sign of χ the component of the nonresonant cubic electronic susceptibility were measured.
Excitation wavelength dependence of the polarized Raman spectrum of p‐dichlorobenzene single crystal
Authors: Urabe Tetsuo , Ito Mitsuo
Published: May 2005

The excitation wavelength dependence of the polarized Raman spectrum of p‐dichlorobenzene single crystal has been measured. The Raman lines of the CC stretching vibration v2(ag) and the ring breathing vibration v4(ag) were found to show great intensity enhancements in the tensor component (aa) when the exciting light was shifted to shorter wavelength. With the assumption of the oriented gas model, the intermediate electronic states contributing to the Raman intensities were determined to be the 1B3u states of the molecule. The Raman lines of v2(ag) and v4(ag) were correlated, from the excitation wavelength dependence of the solution spectrum, to the 1B3u states corresponding to the 1B1u and 1E1u states of benzene, respectively. These correlations are explained in terms of the geometrical structures of the molecule in the electronic excited states.
Raman gain in liquid‐core fibers
Authors: Görner H. , Maier M. , Kaiser W.
Published: May 2005

The frequency dependence of the gain factor of stimulated Raman scattering was measured using tunable dye lasers as signal and pump light sources. In CCl4 and C2Cl4 peak gain factors of 1.3 × 10−9 cm/W and 1.7 × 10−9cm/W were obtained for the major Raman lines with a frequency shift of ν0 = 458 cm−1 and 447 cm−1, respectively. From the experimental gain factor a threshold power of 0.2 W was estimated for a liquid‐core fiber filled with C2Cl4 (diameter 10 μm and length 1 km).
Matrix Raman spectra of the molecular halogens: Resonance Raman spectra of isolated and aggregated I2
Authors: Howard Wilmont F. , Andrews Lester
Published: May 2005

Iodine vapor was suspended in Ar, Kr, Xe and N2 matrices at 16K using several dilutions (Ar/I2=400/1, 1000/1, 2500/1) and the Raman spectra were studied using krypton and argon plasma exciting lines. Two progressions were observed in the Ar/I2=400 samples: a weak one beginning at 212±1 cm−1, which has the gas‐phase I2 spacing, and extending out to 11ν using 5145 Å excitation, and a very strong series beginning at 180 ± 1 cm−1 and extending out to 11ν with vibrational intervals near solid I2 values. The two progressions exhibited comparable intensities in the Ar/I2=1000 experiment. In the Ar/I2=2500 experiments, the gas‐phase‐like series was intense and the 180 cm−1 interval spectrum was absent. The very strong I2 fundamental and regular overtone progressions increased in length and in intensity as the exciting wavelength decreased 6471 to 5145 Å, reaching the absorption band maximum, and then decreased in length and intensity using 4880 and 4579 Å excitation. These observations are characteristic of resonance Raman spectra.
The vibrational spectra of 3,3‐difluoroxetane
Authors: Harris W. C. , Lopata A. D. , Durig J. R.
Published: May 2005

Raman spectra of 3, 3‐difluoroxetane have been recorded from 50 to 3500 cm−1 in all three physical states. In addition, the infrared spectra of gaseous and solid 3,3‐difluoroxetane have been measured between 200 and 3500 cm−1. A vibrational assignment is presented in terms of the C2ν point group which is based upon the observed band contours, depolarization ratios, group frequency correlations and relative band intensities. Although transitions associated with the ring‐puckering mode of 3,3‐difluoroxetane were not directly observed, a weak absorption at 1228 cm−1 has been assigned to a combination band involving the out‐of‐plane skeletal bending and a CH2 wagging mode. With this assignment, the 1 ← 0 transition of ν24 is estimated to be centered near 69 cm−1. The data reported herein will be compared with other studies on similar ring systems.
Spectral theory of molecular rotation‐induced broadening of hyper‐Raman lines in liquids
Authors: Alexiewicz W. , Bancewicz T. , Kielich S. , Ożgo Z.
Published: May 2005

The spectral line shape of hyper‐Raman light scattering in liquids is calculated by the method of irreducible spherical tensors and the theory of rotational Brownian motion. The line broadening due to rotational molecular motion in the liquid is expressed by way of relaxation times τ and is found to depend on nonlinear molecular parameters ∣B̃∣2, which are quadratic functions of the derivatives with respect to appropriate normal coordinates of the hyperpolarizability tensor elements b. Tables of ∣B̃∣2 are adduced for all vibration symmetries of spherical‐top and symmetric‐top molecules. The tensor elements of scattered light intensity are calculated for linearly and circularly polarized incident light. Investigation of hyper‐Raman spectral line broadening is seen as a source of new data on the dynamics of molecules in the liquid state and on their nonlinear optical properties.
Raman spectral studies of cis‐2‐butene‐benzene mixtures
Authors: Lockwood D. J. , Scott J. , Elsdon W. L. , Irish D. E.
Published: May 2005

Raman spectra of neat liquid cis−2‐butene and cis−2‐butene‐benzene mixtures, covering the accessible composition range at 20°C and atomospheric pressure, have been obtained. Parameters of the benzene bands at 605.6, 1178 and 991.6 cm−1 and cis−2‐butene bands at 395.5, 871.5 and 1660 cm−1 are reported. Changes in the parameters as a function of concentration are interpreted in terms of a weak dipole‐induced dipole interaction and the consequent effect on rotational motions and resonance energy transfer.
Resonance and preresonance Raman spectra of nucleotides using ultraviolet lasers
Authors: Pézolet Michel , Yu Tain‐Jen , Peticolas Warner L.
Published: May 2005

The Raman spectra of AMP and UMP have been taken as a function of the laser excitation wavelength at 5145 Å, 4880 Å, 4579 Å, 3638 Å, and 2572.5 Å (the first harmonic of 5145 Å). The Raman bands of adenine which decrease in intensity upon base stacking or base ordering are shown to derive their intensity largely from the ultraviolet absorption band at 2600 Å which also decreases in absorption strength upon base stacking or base ordering (hypochromism). These bands show a strong resonance Raman effect (RRE) with 2572.5 Å laser light. These results are in agreement with the suggestion of Tomlinson and Peticolas [1] that Raman hypochromism is largely derived from UV hypochromism. The hypochromic Raman band of uracil at 1230 cm−1 is shown to derive its intensity from the hypochromic UV band at 2050 Å. None of the bands of uracil appear to show RRE when 2572.5 Å laser radiation is used.

One or two Raman bands in adenine which are not strongly hypochromic show RRE at 2572.5 Å. These bands appear to come from vibrations which have Raman tensors that derive their intensity from higher UV bands as well as the 2600 Å band.
The 650–1050 cm−1 region of the Raman spectrum of gaseous allene
Authors: Hegelund Flemming , Andersen Helge Blom
Published: May 2005

The rotation‐vibrational Raman spectra of the v4(B1)‐, v10(E)‐ and 2v‐bands of allene‐h4 have been obtained. A ground state combination difference analysis of v10 yields the ground state constants A0−B0 = 4.5147 ± 0.0012 cm−1 and DK0 = (1.12 ± 0.10)·10−4 cm−1. A number of upper state constants for the vibrational levels v4, v9, v10 and v11 are obtained.
Laser excited Raman spectrum of ammonium sulfate single crystal
Authors: Venkateswarlu P. , Bist H. D. , Jain Y. S.
Published: May 2005

The Raman spectra of (NH4)2SO4 single crystals have been recorded and measured using an Ar+ laser as a scource of excitation. The polarization behaviour of the Raman lines in different crystal orientations has been studied. The observed shifts in the range 15–3400 cm−1 have been attributed to the phonons of different symmetry species originating from the internal modes of NH and SO ions and the lattice modes calculated from group theoretical considerations.
Low temperature Raman spectra of NH3SO3 and ND3SO3 single crystals
Authors: Lucazeau G. , Lautie A. , Novak A.
Published: May 2005

The Raman spectra of NH3SO3 and ND3SO3 single crystals at 300 and 30 K have been studied in the 4000 to 5 cm−1 range. Infrared spectra of polycrystalline samples have been recorded for comparison in the 4000 to 60 cm−1 region. Twenty‐three Raman and six infrared lattice modes from respectively twenty‐four and fifteen expected ones have been observed. An assignment in terms of factor group symmetry species, rotational and translational vibrations is given. Static and correlation field splitting of internal vibrations is discussed and an assignment of the bands to group frequencies and molecular and factor group symmetry species is proposed. Torsional vibrations are discussed with respect to the amplitude of this motion and the potential barrier opposed to the rotation of the NH3 group has been determined. The NH stretching frequencies are correlated with the N…︁O distances and the v NH band breadth and structure are discussed.
A Raman spectroscopic study of a single crystal of sodium ammonium selenate dihydrate, NaNH4SeO4·2H2O over the temperature range 293–89 K
Authors: Fawcett V. , Long D. A. , Sankaranarayanan V. N.
Published: May 2005

The Raman spectra of single crystals of NaNH4SeO4·2H2O in various orientations are reported for the temperature range 293–89 K. NaNH4SeO4·2H2O undergoes a transition at 180 K from a paraelectric phase to a ferroelectric phase. The changes in the Raman spectra as the crystal is cooled support the evidence from magnetic resonance studies that the transition is of a displacive type with an associated overdamped soft mode. Ordering of the NH ions but not of the complete crystal occurs at the transition temperature.
A study of the lattice region (0–400 cm−1) of the Raman spectrum of a single crystal of sodium ammonium sulphate dihydrate, NaNH4SO4·2H2O over the temperature range 293–87 K
Authors: Fawcett V. , Long D. A. , Sankaranarayanan V. N.
Published: May 2005

The Raman spectra in the lattice region (0–400 cm−1) of single crystals of NaNH4SO4·2H2O in various orientations are reported for the temperature range 293–87 K. NaNH4SO4·2H2O undergoes a transition at 101 K from a paraelectric phase to a ferroelectric phase. The changes in the Raman spectra as the crystal is cooled support the evidence from magnetic resonance studies that a large lattice distortion occurs at the transition temperature.
Frequency calibration in high‐resolution Raman spectroscopy
Authors: Brodersen Svend , Bendtsen Jørgen
Published: May 2005

A technique is described for the frequency calibration of high‐resolution Raman spectra recorded on photographic plates. The frequencies of the Th calibration spectrum are fitted to a calibration polynomial in the observed positions, and the coefficients of this polynomial are determined as functions of the grating angle. For a given calibration the polynomial coefficients are constrained to the values of these functions. In this way the information from all previous calibration spectra is used to improve the accuracy of the calibration of any single exposure. Further, a valuable check is obtained on the overall experimental procedure by requiring the polynomial coefficients to be smooth functions of the grating angle.
A Raman spectroscopic investigation of a single crystal of potassium selenate, K2SeO4 over the temperature range 293–87 K
Authors: Fawcett V. , Hall R. J. B. , Long D. A. , Sankaranarayanan V. N.
Published: May 2005

The Raman spectra in the region 250–1000 cm−1 are reported for six orientations of a single crystal of K2SeO4 over the temperature range 293–87 K. In the spectra of the paraelectric phase at 293 K, splitting of the internal vibrations of the SeO ion is in accord with the predictions of group theory. No significant differences are found in this internal frequency region in the ferroelectric phase at 87K. It is concluded that only minor lattice distortions are occurring at the ferroelectric phase transition which may be associated with a soft mode in the 22 cm−1 region.