bluuebunny/crossref_metadata_2025_split huggingface dataset:
A standardized interview for the elderly (GMS): Reliability studies comparing the Dutch language version with the original
Authors: Hooijer C. , Jonker C. , Dewey M. E. , Van Tilburg W. , Copeland J. R. M. 
Published: January 2005

AbstractA Dutch translation of the Geriatric Mental State Schedule was prepared and used. Here we report the replication of previous reliability (inter‐rater and retest) studies and present the first figures for the reliability of factor scores. The results have proved valuable for solving some (apparent) discrepancies between previous studies. Overall reliability results were shown to be satisfactory. Using the GMS scores Dutch patient groups appeared to be similar to the US‐UK project patient samples. Preliminary results of a small follow‐up study are provided. The total set of results makes it plausible that Dutch findings can be generalized and the use of the GMS in Holland can be extended.
Jim who? Recall of national leaders by elderly people in three countries
Authors: Ames David , Ashby Deborah , Flicker Leon , Snowdon John , West Christopher , Weyerer Siegfried 
Published: January 2005

AbstractThe Organic Brain Syndrome scale (OBS) of the Brief Assessment Scale (BAS) was administered to 1202 elderly subjects in London, Mannheim, Sydney and Melbourne. Subjects' knowledge of current and last national leaders was assessed, and two methods of scoring the OBS were compared. Taking into account the degree of cognitive impairment found using seven items of the OBS were compared. Taking into account the degree of cognitive impairment found using seven items of the OBS other than the national leader item, knowledge of current leader was much more consistent across countries than was knowledge of last leader. When subjects were allocated an error point for failing to know either current or last leader, dementia prevalence measured by the OBS was consistently 5–6% less than that found when they were allocated an error point for failing to know both leaders. Future studies using the BAS should publish prevalence data for both scoring methods in order to permit comparison between studies.
The role of cell cycle on polyplex‐mediated gene transfer into a retinal pigment epithelial cell line
Authors: Männistö Marjo , Rönkkö Seppo , Mättö Mikko , Honkakoski Paavo , Hyttinen Mika , Pelkonen Jukka , Urtti Arto 
Published: January 2005

AbstractBackgroundRetinal pigment epithelium (RPE) maintains the function of photoreceptors and eyesight and is an important target for gene delivery. Since in some diseases RPE cells proliferate uncontrollably, we investigated the role of cell cycle in non‐viral gene delivery into a RPE cell line (D407).MethodsD407 (human) cells were transfected with cationic DNA complexes. Cells were synchronized into different phases of the cell cycle and transfected using poly‐L‐lysine (PLL) or polyethyleneimine (PEI) carriers for 3 h. The effects of different reporters (β‐galactosidase, luciferase) or promoters (CMV, SV40, tk, PDE‐β) on gene expression were evaluated 43 h later. Cellular uptake of ethidium monoazide/DNA complexes with PLL or PEI was determined by flow cytometry. Fluorescent DNA and the complexes were localized with a confocal microscope. The role of cell cycle in transcription was evaluated by stable luciferase‐expressing cells.ResultsPLL showed lower transfection levels than PEI in synchronized cells and only slight dependence on cell cycle. PEI showed minimal efficiency at G1 phase and maximum level at S phase. All promoters and reporter genes showed dependence on cell cycle. Cellular uptake of polyplexes was highest at S phase (80–90%) and lowest at G1 phase (5–30%). Confocal microscopy showed minor differences of free DNA between groups in the nucleus, where it was largely carrier‐bound. Cell cycle effects on luciferase expression were clear in stable cell lineConclusionsTransfection by polyplexes in the RPE cell line is influenced by cellular uptake and transcription, and both processes are cell‐cycle‐dependent. The results have implications in retinal gene therapy. Copyright © 2004 John Wiley & Sons, Ltd.
The use of microchemical techniques for the identification of new transmitter molecules in neurons
Authors: Giacobini E. 
Published: January 2005

AbstractThe author reviews available microtechniques and results on cellular analysis of single neurons emphasizing the identification of putative neurotransmitter molecules.Highly sensitive microquantitative methods for identification and assay of known and putative neurotransmitters have been developed within the last 5 years. Several of the methods reported in the article fulfill the requirements of both specificity and sensitivity for exploring and measuring the level of transmitter molecules in single neurons.Some of the available techniques, mostly those which associate GC or TLC with MS, have been able to unambiguously demonstrate the presence of putative neurotransmitter molecules, or at least of substances which are strongly suspected of fulfilling a functional role in the nervous system.
Topographical distribution of acetylcholinesterase and butyrylcholinesterase in the cerebral hemisphere of the garden lizard, calotes versicolor
Authors: Sethi J. S. 
Published: January 2005

AbstractDifferential patterns of distribution of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are observed in the cerebral nuclei and fiber tracts of Calotes versicolor. The majority of the nuclei reveal a positive reaction for AChE varying from moderate to intense. In contrast, almost all the nuclei are found negative to BChE, except for the area of the nucleus commissurae anterioris and of the paleostratum where the positive activity is due to BChE positive fibers. The medial forebrain bundle demonstrates intense activity for AChE, while the lateral forebrain bundle and commissures present a negative picture. Interestingly, all the fiber bundles and commissures show an intense reaction for BChE. The nature of nuclei and fiber tracts in relation to the differential patterns of AChE and BChE is discussed.
A model of GABA transport by cortical synaptosomes from the long‐evans rat
Authors: Wheeler D. D. , Hollingsworth R. G. 
Published: January 2005

AbstractThe initial velocity of uptake of GABA by cortical synaptosomes from the Long‐Evans rat has been measured as a function of both sodium and GABA concentration. These data were then fitted to the rate equation for each of several possible models, and the models giving least error were identified. Although one cannot unequivocally distinguish between two of the models on the basis of the goodness of fit, deductions based on the fits of subsets of the models point to one of the two models. The major predictions from this model are as follows: (1) Uptake of GABA is totally sodium‐dependent. (2) Although plots of 1/v versus 1/[Na]2 are nonlinear, the coupling ratio for transport (Na/GABA) is 2. (3) For transport to take place, the order of combination with carrier must be Na, Na, GABA. (4) Maximal velocity will occur only at infinite Na and GABA concentrations. (5) There is a sigmoidal relationship between apparent maximal velocity (Va) and [Na]. (6) Kt, the [GABA] that gives a velocity equal to Va/2, rises and then falls as [Na] is increased from zero, passing through a maximum at 33.52 mM [Na]. (7) The relationship between initial velocity and [Na] is sigmoidal. (8) Jm, rate of uptake with infinite [Na], is hyperbolically related to [GABA]; Jm approaches Vmax as [GABA] becomes very large. (9) KNa, the [Na] giving a velocity equal to Jm/2, declines rapidly from 10−7M to 10−5M GABA, but is essentially constant at 10−4M and above. (10) One GABA molecule is translocated per carrier molecule.The model is consistent with observations in the literature concerning the effects of sodium on the kinetics of transport.
Cerebral amino acid levels and uptake in rats after portocaval anastomosis : I. Regional studies in vitro
Authors: Zanchin Giorgio , Rigotti Paolo , Bettineschi Fulvio , Vassanelli Paolo , Battistin Leontino 
Published: January 2005

AbstractUptake of various amino acids was studied in slices from brain regions of rats four weeks after portocaval anastomosis.No differences of the inulin compartment were observed between control and experimental animals.After 60‐minutes incubation, uptake showed an overall pattern of diminution. This was more evident for some amino acids: valine, methionine, and lysine exhibited a lowering of about 30%, which was fairly uniform in the four tested regions; others showed a regional decrease – alanine in pons‐medulla, phenylalanine in cerebellum, histidine and GABA in mesodiencephalon.This decrease did not seem to be related to transport classes. The restricted entry of amino acids into brain cells in portocaval encephalopathy is somewhat difficult to explain; a decreased rate of protein synthesis may be of some importance, but other factors, such as a “carrier” impairment, effects on release and on amino acid metabolism, may also be involved.
Effects of anesthetics on sulfate transport in the red cell
Authors: Makriyannis Alexandros , Fesik Stephen W. 
Published: January 2005

AbstractWe have measured the effect of anesthetics on sulfate transport in the human erythrocyte and have found that a wide variety of chemical classes of anesthetics, including the anesthetic steroid alphaxalone, inhibit sulfate transport in human erythrocytes at concentrations paralleling the concentrations that block nerve conduction. These experiments suggest that anesthetics act through a general mechanism and that the sulfate transport system in the red blood cell is a good model for studying the mechanism of action of anesthetics.
Separation of radiolabelled protein from brain and spinal cord of spinal hemisected rats on SDS polyacrylamide slab gels
Authors: Wells Michael R. 
Published: January 2005

AbstractAfter hemisection of the spinal cord in rats, alterations in amino acid incorporation into protein have been observed in both brain and spinal cord. Proteins mediating these changes have been studied in the present experiment. Male, Long‐Evans hooded rats were given either a laminectomy and dura incision (sham) at spinal segment T2, a left spinal cord hemisection, or no operative procedures. One hour prior to utilization at 1, 3 and 14 days postoperation, animals were injected subcutaneously with 200 μCi of [3H]‐L‐lysine and 200 μCi of [3H]‐L‐amino acid mixture. Samples were prepared for electrophoresis and proteins separated on linear gradient SDS polyacrylamide slab gels (7.5–20% acrylamide). The Gel slabs were cut into slices and processed for scintillation counting. In right somatomotor cortex, there was evidence for a general stimulation of amino acid incorporation at one day postoperation in animals which received surgery. At other postoperation intervals, significant increases in proteins in the regions of 90–150,000, 50–65,000 and 35–45,000 molecular weight (MW) were observed. In spinal cord, significant increases in proteins in the regions of 55–65,000, 30–45,000 and 15,000 MW were observed over postoperation time in all animals receiving surgery compared to normals. A large, significant increase in the radioactivity of proteins in the region of 18–20,000 MW were observed in the spinal cord lesion site of spinal hemisected animals alone at three days postoperation. These results indicate that increases in amino acid incorporation into the brain and spinal cord of laminectomized and spinal hemisected animals observed previously are the result of both specific and nonspecific changes in protein incorporation of precursors.
The fate of tritium‐labeled reserpine in the chick embryo: A preliminary report
Authors: Dahl Anne‐Lise , Giacobini E. , Serra G. , Manara L. 
Published: January 2005

AbstractAfter a single administration of 3H‐reserpine, 10 μgm, 2.5 μCi, into the yolk of fertilized chicken eggs, gross radioactivity (reserpine plus degradation products) and the unchanged labeled drug, separated by thin layer chromatography, were assayed on the 8th and 19th day of incubation. Nanogram per gram concentrations of unchanged 3H‐reserpine were recovered at both times. The 3H‐reserpine recovered in the whole egg on the 8th day of incubation accounted for up to 20% of the administered dose. On the 19th day of incubation, brain showed the largest share (28%) of 3H‐reserpine as a percentage of gross radioactivity of all organs investigated. Reserpine underwent considerable biodegradation in the developing chick embryo, but the concentrations of unchanged drug recovered in embryonal tissues throughout development were of the same order as those persisting in target organs of rats given a pharmacological dose of reserpine.
Role of glycoproteins in the uptake of L‐ 14C ‐ leucine by a synaptosomal fraction
Authors: Rossowska Magdalena 
Published: January 2005

AbstractThe present study deals with the effect of modification of membrane glycoproteins on the accumulation of amino acids by isolated synaptosomal fractions, measured by the uptake of 14C‐leucine. Superficial sugar receptors were modified by concanavalin A, neuraminidase, and neuraminidase followed by concanavalin A binding. It is demonstrated that neuraminidase treatment followed by concanavalin A binding results in significant diminution of 14C‐leucine uptake. A similar effect was observed in experimental hypoxia followed by concanavalin A binding to isolated synaptosomal fractions.In this case, however, (Na+K+) –ATPase activity remained unchanged. These results seem to indicate that 14C−leucine uptake was dependent on integrity of glycoprotein structure of synaptosomal membranes.
Neuron‐specific enolase levels in primary cultures of neurons
Authors: Schengrund C.‐L. , Marangos P. J. 
Published: January 2005

AbstractPrimary neuronal cell cultures, derived by centrifugal elutriation of cells dissociated from embryonic rat cerebra, have been analyzed for their content of neuron‐specific enolase (NSE) and non‐neuronal enolase (NNE). Both immunocytochemical staining and radioimmunoassay establish that NSE is present in these cells. Furthermore, the observed increase in NSE and decrease in the NNE/NSE ratio with time in culture parallels that observed in vivo. It has recently been shown that during in vivo neurogenesis and maturation a “switch over” occurs from NNE to NSE which correlates with neuronal differentiation. The presence of a neuron‐specific protein in these primary neuronal cultures and the changes observed during growth further support their use as a model system for the study of nervous tissue differentiation.
Sodium dependence of GABA transport in rat hypothalamic synaptosomes
Authors: Wheeler D. D. 
Published: January 2005

AbstractThe sodium dependence of γ‐aminobutyric acid (GABA) uptake has been studied in rat hypothalamic synaptosomes, and the results compared to previous studies in cortical synaptosomes. Initial velocity of GABA uptake was measured as a function of both GABA and sodium concentration, and these data were fitted to the rate equation for each of several plausible models. The minimal best‐fit model was found to be identical to that for cortical synaptosomes. However, the constants which quantitate the model were found to differ for hypothalamus and cortex. As a result, uptake at any combination of [Na] and [G] in hypothalamic synaptosomes is approximately double that in cortical synaptosomes. The rate equation for the minimal best‐fit model was utilized to define and compute certain parameters which are useful in comparing transport mechanisms (Vmax, Va, Kt, Jm, and KNa). In all cases, differences were found between hypothalamus and cortex.
Spatial distribution of catecholaminergic cells in the fish retina
Authors: Negishi K. , Drujan B. D. , Laufer M. 
Published: January 2005

AbstractThe cell density, distribution pattern, and morphology of catecholaminergic (CA) cells have been studied by fluorescence microscopy of retinal flatmounted preparations from various species of fresh water, estuary, and marine fishes, and the toad. In all fish retinas examined the CA‐cell density (cells/mm2) is lowest in the central region surrounding the optic disc, slightly higher in the intermediate region, and highest in the periphery. The size of CA‐cells is smaller the higher their density. Following administration of L‐Dopa, dompamine, or noradrenaline, the density of CA‐cells approximately doubled, due to the appearance of small fluorescent cells. CA‐cells are arranged in rows along radial lines which fan out from the optic disc. In large cells of the central and intermediate regions three to five processes arise from the soma and extend and ramify irregularly in the inner plexiform layer, while in small cells from the intermediate and peripheral regions two processes arise from opposite poles and extend regularly in a direction perpendicular to the rows of cells and parallel to the retinal margin. In the retina of the marine fish Holocentrus sp CA‐cells are fewer in number compared to other fish studied and their processes extend without any regular pattern. In the toad their size and density are homogenous throughout the retina, and their processes show a regular arrangement.
S‐180 cells secrete nerve growth factor protein similar to 7S‐nerve growth factor
Authors: Barklis E. , Perez‐Polo J. R. 
Published: January 2005

AbstractThe nerve growth factor protein (NGF) has been identified by biological assay and rocket immunoelectrophoresis in media conditioned by monolayers of mouse S‐180 sarcoma cells, a transformed cell line of salivary gland origin. By utilization of a purification procedure designed to enrich for acid‐dissociable, high‐molecular‐weight complexes similar to the 7S‐NGF isolated from male mouse submaxillary gland, it has been determined that a significant portion of mouse sarcoma NGF is initially present as a complex at neutral pH with a molecualr weight indistinguishable from that of 7S‐NGF. At pH 4.0 the mouse sarcoma NGF complex dissociates, and the active subunit can be isolated as a species with a molecular weight of less than 40,000. The induced dissociation at pH 4.0 of the mouse sarcoma NGF high‐molecular‐weight complex, as well as the complex's behavior in isoelectric focusing and sucrose gradient sedimentation is consistent with the hypothesis that 7S‐NGF is packaged as a subunit containing protein intracellularly prior to secretion into the extracellular space. Moreover, the stability of the mouse sarcoma NGF complex at dilute concentrations is similar to that reported for the purified 7S‐NGF complex.
Ontogenesis of neuropeptide degrading enzymes in the mouse brain
Authors: Faivre‐Bauman A. , Knisatschek H. , Tixier‐Vidal A. , Bauer K. 
Published: January 2005

AbstractThe ontogenesis of neuropeptide degrading enzymes was studied in the mouse brain, from the 10th gestational day up to adulthood. Two activities were followed: the pyroglutamate aminopeptidase and the post‐proline cleaving enzyme, using either TRH or specific fluorogenic peptides as substrates. In the hypothalamus as well as in cerebral hemispheres, the specific activities of both enzymes was highest on the 13th fetal day and decline thereafter until the 20–22nd post‐natal day, with a plateau around birth. In contrast, a classical peptidase, the leucyl‐arylamidase increased only in fetal life, and reached the adult level before birth.
Monoclonal antibodies against mouse nerve growth factor produced by somatic cell hybrids
Authors: Businaro Rita , Butler Richard H. , Rubenstein Allan E. , Revoltella Roberto P. 
Published: January 2005

AbstractSpleen leukocytes from rats and mice immunized against mouse 2.5S nerve growth factor (NGF) and peripheral blood leukocytes from rabbits hyperimmunized against the same antigen were fused with the mouse plasmacytoma P3 × 63Ag8. Hybridomas were screened by immunological assays (microcomplement fixation test and solid phase radioimmunoassay) for production of antibodies that reacted with NGF. Significant variations were seen between culture fluids from different hybrid cells. In addition, most but not all hybridoma antibodies that reacted immunologically with NGF prevented neurite outgrowth from 8‐day chick embryo sensory ganglia explants after binding to NGF. These results suggest that the hybridoma antibodies produced by the different clones react with different antigenic sites on the NGF molecule.
Localization of kainic acid‐sensitive cells in mammalian retina
Authors: Hampton Cynthia K. , Garcia Charles , Redburn Dianna A. 
Published: January 2005

AbstractShort‐term (15 minutes) in vitro exposure to kainic acid (KA), a rigid structural analog of L‐glutamic acid (Glu), caused two morphologically distinct neuronal lesions in retinas of several species. In rabbit retina, one type of lesion was characterized by rapid swelling after exposure to low concentrations of KA (10−4 M). This lesion was observed in elements of both plexiform layers and, more specifically, in cell bodies and neurites of horizontal cells that contact cones. A few cell bodies from the amacrine cell layer showed some limited swelling. The swelling was completely blocked when sodium was removed from the incubation medium. The second type of lesion was generally seen after longer exposures of after exposure to higher concentrations of KA and was evidenced by degeneration of neurons in the amacrine and ganglion cell layers. One exception was noted in that a few cells from the ganglion cell layer degenerated even under low exposure conditions. The second type of lesion was not blocked by removal of sodium ions. Photoreceptor cells appeared resistant to all effects of KA. The results suggest that a correlation may exist between certain KA‐induced lesions of the retina and putative glutamoreceptive neurons. At the same time, the two types of retinal lesions produced by KA are morphologically and chemically differentiable and may be useful in elucidating the differences between specific, Glu‐related toxicity and nonspecific toxicity of KA.
The role of cAMP in the induction of ornithine decarboxylase by nerve and epidermal growth factors
Authors: Lacorbiere Monique , Schubert David 
Published: January 2005

AbstractNerve growth factor (NGF), epidermal growth factor (EGF), adenosine 3′,5′‐cyclic monophosphate (cAMP), and cholera toxin all increase the specific activity of ornithine decarboxylase (ODC) in the PC12 nerve‐like cell line. A phosphodiesterase inhibitor augments the effect of NGF on the induction of ODC in these cells, while it is only additive with the EGF response. These data suggest that cAMP has an intermediary role in the induction of ODC by NGF and that cAMP is not involved in the EGF response.
In vivo structure of frog sciatic nerve myelin membranes: An x‐ray diffraction study at 13Å resolution
Authors: Padróoan Raúual , Mateu L. 
Published: January 2005

AbstractThe x‐ray diffraction pattern of myelin membranes from a frog sciatic nerve was recorded in vivo at 13 äAR resolution using a new experimental technique recently developed in our laboratory. The electron density profile was determined for the myelin membranes first in vivo and then, after elimination of the intraneural blood microcirculation, by transection of the nerve. The small structural differences observed between these conditions were statistically nonsignificant (at 95% confidence level). In addition, our results show that the stacking disorder that is present in the myelin membranes of freshly dissected frog sciatics is also characteristic of the myelin sheath in vivo.