bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of fish glial cells in culture: Possible implications as to their lineage
Authors: Sivron Tomer , Jeserich Gunnar , Nona Shmaiel , Schwartz Michal 
Published: January 2005

AbstractRegeneration of injured central nervous system axons is largely dependent on the response of the associated nonneuronal glial cells to injury. Glial cells of the mammalian central nervous system, unlike those of fish, are apparently not conducive to axonal regeneration. While the lineage of rat glial cells is well characterized and its role in the support or inhibition of regenerative growth is beginning to be understood, little is known about fish glial cells. Accordingly, glial cells in cultures of adult goldfish brain and of newly hatched goldfish larvae were studied in an attempt to establish their lineage. The cells were identified by means of indirect immunofluorescence, using antibodies against fish astrocytes and oligodendrocytes. The cell count in the cultures increased from a small number of cells at 24 h after plating to a large number of both astrocytes and oligodendrocytes after 1 week in culture. Both of these cell types had originated from proliferating cells, as shown by their uptake of tritiated thymidine and by the inhibition of cell proliferation by 5‐fluoro‐2′‐deoxyuridine. Both astrocytes, i.e., glial fibrillary acidic protein‐positive cells, and oligodendrocytes, i.e., 6D2‐positive cells, were positively labeled also by A2B5 antibodies, which are known to label progenitors of type‐2 astrocytes and oligodendrocytes in the rat optic nerve. The results suggest that A2B5 positive progenitor cells in the goldfish central nervous system, as in the rat optic nerve, might be a common progenitor of astrocytes and oligodendrocytes. © 1992 Wiley‐Liss, Inc.
Regulation of plasminogen activators and type‐1 plasminogen activator inhibitor by cyclic AMP and phorbol ester in rat astrocytes
Authors: Tranque Pedro , Robbins Richard , Naftolin Frederick , Andrade‐Gordon Patricia 
Published: January 2005

AbstractTwo plasminogen activators (PAs): tissue‐type plasminogen activator (t‐PA) and urokinase‐type plasminogen activator (u‐PA), as well as the type‐1 plasminogen activator inhibitor (PAI‐1) are synthesized and secreted by rat astrocytes. Preliminary studies suggest that PA activity plays a role in astrocyte development and differentiation. We have examined the regulation of the PA system by the cAMP‐dependent protein kinase (PKA) and protein kinase C (PKC) in purified rat astrocyte cultures. PKA activity was increased by exposing cultured astrocytes to forskolin or dibutyryl cyclic AMP, whereas PKC activity was stimulated with phorbol‐12‐myristate 13‐acetate (PMA). Activation of both second‐messenger pathways produced a time‐ and dose‐dependent increase in the total PA activity. However, based on SDS‐PAGE/zymography we found that forskolin increased t‐PA activity and reduced u‐PA activity, whereas PMA treatment caused a significant increase in u‐PA activity without altering t‐PA activity. Reverse zymography analysis revealed that astrocyte PAI‐1 activity is decreased by forskolin and increased by PMA. Together, these results demonstrate that the components of the PA system in rat astrocytes are independently and reciprocally regulated by PKA and PKC. Our findings raise the possibility that the plasminogen activator system could be involved in some of the actions of growth factors and/or neuromodulators that modulate PKC or PKA in astrocytes. © 1992 Wiley‐Liss, Inc.
Altered antigen expression of microglia in the aged rodent CNS
Authors: Perry V. H. , Matyszak M. K. , Fearn S. 
Published: January 2005

AbstractMicroglia, the resident macrophages of the central nervous system, are characterised by a highly specialized morphology and unusual antigenic phenotype. Microglia appear to be downregulated by their microenvironment when compared to other tissue macrophages. We have studied the microglia in brains of healthy, aged rats with a panel of monoclonal antibodies. We have found that microglia in the brains of these aged rats express antigens that are downregulated or absent from microglia of juvenile rats. The stimuli which give rise to this upregulated phenotype are not known. Age related changes in the phenotype of microglia should be taken into account when considering the possible role of microglia in neuropathological conditions.
Polymorphonuclear leukocytes in brain parenchyma after injury and their interaction with purified astrocytes in culture
Authors: Moreno‐Flores M. Teresa , Bovolenta Paola , Nieto‐Sampedro Manuel 
Published: January 2005

AbstractAt a time after brain injury when removal of debris and secondary cell death were prevalent, many polymorphonuclear neutrophils were observed in injured tissue. Because neural damage could be mediated by activated neutrophils, we tested in vitro the effect of these leukocytes and other blood, components on central nervous system cells. At concentrations similar to those present in blood, polymorphonuclear leukocytes resulted in astrocyte detachment from the substrate and aggregation. These neutrophil concentrations affected both epithelioid and stellate HNK1/A2B5‐negative (type 1) astrocytes but not hippocampal neurons. Substrate detachment was partially prevented by corticosterone, but not by protease inhibitors or free‐radical scavengers.Co‐cultures of purified cortical astrocytes with neutrophils (1/20 cell ratio) contained at the beginning of the experiment ε93‐98% astrocytes with type 1 markers. After 6‐8 days co‐culture, many stellate cells insensitive to neutrophils seemed to migrate out of the aggregates. About 70% of these resistant cells had immunological markers typical of type 2 astrocytes. The possible relevance of these findings to reactive astrogliosis and secondary neuronal death is discussed.
Development of cell‐cell coupling among cells of the oligodendrocyte lineage
Authors: von Blankenfeld G. , Ransom B. R. , Kettenmann H. 
Published: January 2005

AbstractThe development of functional gap‐junctional communication was studied in cells of the oligodendrocyte lineage. The presence of cell‐cell coupling was determined by the passage of current between cells using a double whole‐cell patch‐clamp system or by injecting the low molecular weight dye Lucifer yellow into individual cells via a patch pipette and observing the diffusion of the dye into adjacent cells. The developmental stage of the cells under study was determined using antibodies to specific surface markers (04,01, and 010) that characterize cells of sequential maturity along the oligodendrocyte lineage (Kuhlmann‐Krieg et al., 1988; Sommer and Schachner, 1981; 1982). Both stages of precursor cells of this lineage, 04+ and 04−, almost never showed dye or electrical coupling, even though they were in close physical contact with other cells. The O1‐positive oligodendrocytes with simple morphology were also noncoupled, with only few exceptions. In contrast, more than 40 percent of more mature, O10‐positive oligoden‐drocytes showed cell‐cell coupling detectable with both dye and current injection. Thus, the formation of gap junctions between cells of the oligodendrocyte lineage does not occur with, but some time after, the commitment of the cell to becoming an oligodendrocyte.
Effects of interleukin‐1β and tumor necrosis factor‐α on the expression of glial fibrillary acidic protein and transferrin in cultured astrocytes
Authors: Oh Young J. , Markelonis George J. , Oh Tae H. 
Published: January 2005

AbstractRecent evidence suggests that interleukin (IL)‐1 and tumor necrosis factor (TNF) may play a role in astrogliosis following injury to the CNS. The short‐term biochemical effects of these immune‐related cytokines were determined on cultured rat polygonal and process‐bearing astrocytes. Both IL‐1 and TNF stimulated the rate of thymidine incorporation in polygonal astrocytes up to 137% and 215%, respectively, over the level observed in untreated controls. By contrast, thymidine incorporation was relatively unaffected by these cytokines in process‐bearing astrocytes. The cytokines did not significantly affect the level of glial fibrillary acidic protein (GFAP) within polygonal astrocytes, even though they appeared to downregulate the expression of GFAP mRNA by as much as 62%. Both cytokines increased the intracellular expression of transferrin (Tf) within some polygonal astrocytes. In untreated control cultures, fewer than 2% of polygonal astrocytes were immunoreactive for Tf. By contrast, approximately 30% of polygonal astrocytes treated with IL‐1 or TNF‐α became strongly immunoreactive for Tf. Neither IL‐2 nor a number of other known growth factors appeared to alter the level of immunoreactive Tf in these cells. Process‐bearing astrocytes were negative for Tf, regardless of the treatment used. Northern blot analysis demonstrated that the level of Tf mRNA in cultures of polygonal astrocytes increased 148% above the level observed in untreated controls following treatment with either IL‐1 or TNF, whereas no change was observed following treatment with IL‐2. These results suggest that increased levels of particular cytokines known to be present in injured CNS can produce pronounced biochemical alterations within a subtype of cultured astrocytes. © 1993 Wiley‐Liss, Inc.
N‐ and R‐cadherin expression in the optic nerve of the chicken embryo
Authors: Redies Christoph , Takeichi Masatoshi 
Published: January 2005

AbstractCadherins are a family of molecules mediating Ca2+‐dependent cell‐cell adhesion in various tissues. N ‐ and R‐cadherin are expressed in the chick embryonic CNS and differ in their expression pattern during development. Here we focus on the differential expression of N ‐ and R‐cadherin in the early optic nerve. N‐cadherin is expressed by the retinal neurites growing through the optic nerve. R‐cadherin is expressed by the early optic nerve glia, which derives from the optic stalk neuroepithelium and corresponds to an immature form of the type‐1 astrocyte described in rat optic nerve. The close contact between the plasma membranes of the retinal neurites and the optic nerve glia is believed to be important in guiding retinal axons through the optic nerve. Using neuroblastoma cell lines transfected with R‐cadherin, we demonstrate that the N‐cadherin‐positive retinal axons can use R‐cadherin as a substrate for axon elongation. These results suggest that the R‐cadherin expressed by the early optic nerve glia might provide a molecular substrate for the growth of N‐cadherin‐positive retinal axons through the optic nerve. © 1993 Wiley‐Liss, Inc.
Development of an astrocytic response to lesions of the spinal cord in the north american opossum: An immunohistochemical study using anti‐glial fibrillary acidic protein
Authors: Ghooray Ganesh T. , Martin George F. 
Published: January 2005

AbstractWe have shown previously that rubral axons grow around a lesion of their pathway in developing opossums and that a critical period exists for that plasticity. The critical period begins when rubral axons first reach the level of the lesion and ends sometime between postnatal days (PD) 26 and 30. The aim of the present study was to examine the development of an astrocytic response to lesioning the spinal cord to determine if there is a temporal correlation between the development of such a response and the end of the critical period. The astrocytic response was examined immunohistochemically, 2 and 4 weeks after hemisecting the thoracic spinal cord, using an antibody to glial fibrillary acidic protein (GFAP). A response was first seen at PD21 in the 2‐week series. The response was relatively mild, however, and limited to the white matter. When the lesion was made at PD26. the response was still restricted to the white matter, but hypertrophied astrocytes were found at the gray/white matter junction and cystic cavities were present. When the lesion was made at PD41, the response had spread to the gray matter and it occupied a larger area rostral and caudal to the lesion than at earlier ages. The animals allowed to survive 4 weeks after lesioning were subjected to a second operation 4‐5 days before sacrifice so that Fast Blue could be injected bilaterally two to three segments caudal to the lesion. When the hemisection was made at PD15, a response was present in the ventral and ventrolateral funiculi, but not in that part of the lateral funiculus that contains rubrospinal axons. As expected from previous studies, rubral neurons were labeled contralateral to the lesion, suggesting that their axons had grown around it. When the lesion was made at PD21, the glial response was still limited to the white matter, but it extended into that part of the lateral funiculus that contains rubral axons. In spite of the presence of a glial response, rubral neurons were still labeled contralateral to the lesion. When the lesion was made at PD26, hypertrophied astrocytes were present at the gray/white matter junction and small cavities were noted at the lesion site. In such cases, there was no evidence for rubrospinal plasticity. An astrocytic response was not observed in the gray matter of the dorsal horn, an area used by rubral axons to grow around a lesion of their pathway, until well after the end of the critical period. We conclude that the initial development of a glial scar in the white matter after lesioning does not determine the end of the critical period for rubrospinal plasticity. Loss of rubrospinal plasticity correlates most closely with the appearance of hypertrophied astrocytes at the gray/white matter junction and the formation of cystic cavities.
Voltage‐dependent sodium and potassium currents in cultured trout astrocytes
Authors: Glassmeier G. , Jeserich G. , Krüppel T. 
Published: January 2005

AbstractVoltage‐gated ionic currents were recorded from cultured trout astrocytes with the whole‐cell variation of the patch‐clamp technique. In a subpopulation of astrocytes depolarizations above −40 m V activated a fast transient inward current that was identified as a sodium current by ion substitution experiments, its current reversal potential, and its TTX‐sensitivity. Regarding threshold of activation, peak current voltage, and amplitude this current closely resembled those previously described for mammalian astrocytes. Voltage‐dependence of inactivation and kinetics, however, markedly differed from the “glial‐like” sodium current occurring in mammalian hippocampal or optic nerve astrocytes, since the sodium current of trout astrocytes exhibited a faster time course of activation and decay and a more depolarized steady‐state inactivation curve with midpoints close to −60 mV. During a period of 2 weeks in culture the biophysical properties of the sodium current did not change significantly, albeit a continuous decrease in current density was observed. At depolarizing voltage steps positive to −40 mV, additionally voltage‐gated potassium outward currents were evoked, which could be separated into a steady‐state current with delayed rectifier properties and an inactivating component resembling the A‐type current. Moreover, in a subpopulation of astrocytes an inward potassium current was elicited at hyperpolarizing potentials, which exhibited biophysical features consistent with the potassium inward rectifier of mammalian astrocytes. © 1994 Wiley‐Liss, Inc.
Psychiatric morbidity among residents in a home for the elderly in spain: Prevalence of disorder and validity of screening
Authors: Lobo Antonio , Ventura Tirso , Marco Carlos 
Published: January 2005

AbstractAll residents in a home for elderly válidos (able) in Spain were interviewed and 101 completed the study. Non‐medical interviewers adminstered the GHQ‐28 items and either Zung's Self‐Rating Depression Scale (SDS) (N=69) or the Geriatric Depression Rating Scale (GDS) (N=31). The residents were also examined blind by psychiatrists standardized in the use of the Clinical Interview Scale (CIS), who also administered the ‘Mini‐Examen Cognoscitivo’, the Spanish version of the Mini‐Mental State Examination (MMSE), and diagnosed the identified ‘cases’ according to ICD‐9 criteria. Twenty‐one residents (20.8%) were considered to be ‘cases’ on the basis of the CIS; 14 (13.9%) were diagnosed as depressed and only four (4%) were diagnosed as being demented, although the mean age of the sample was 81.9 years (SD=5.6). Most ‘cases’; were of mild intensity and the differences with ‘non‐cases’; seemed quantitative rather than qualitative. The GHQ‐28 correctly identified 81.5% of ‘cases’; with a cutting score of 5/6 (sensitivity 70%, specificity 84.4%) and 77.4% of ‘cases’; with a cutting score of 4/5 (sensitivity 85%, specificity 75.3%), suggesting a discriminative power almost as good as in adult individuals. In the pilot study, the GDS performed better than the SDS as a screening instrument. The addition of the ‘Mini‐Examen’ would have improved the sensitivity of both the GHQ‐28 items and the SDS.
Cognitive effects of ect in the elderly: Preliminary findings
Authors: Russ Mark J. , Ackerman Sigurd H. , Burton Leslie , Shindledecker Richard D. , Goldberg Elkhonon 
Published: January 2005

AbstractClinical recovery, cognitive function, and ward behavior indicative of organic brain syndrome were assessed in 12 elderly, depressed patients before, and approximately one week after, treatment with electroconvulsive therapy (ECT). There was a statistically significant improvement in depression, and ward behavior, whereas cognitive function was unchanged. These findings support and extend prior studies which indicate that ECT in the treatment of depression in the elderly is not associated with functionally significant decrements in cognitive performance.
Ergot mesylates for alzheimer's disease: A year‐long double‐blind trial of 3 mg vs 12 mg daily
Authors: Jenike Michael A. , Albert Marilyn , Baer Lee , Gunther Jeanette , Corvino Christine 
Published: January 2005

AbstractOf 25 patients who entered a year‐long double‐blind comparison study of high (12 mg/day) versus low (3 mg/day) dosages of ergot mesylates (Hydergine), 17 completed the full year of study and no patients suffered problematic side‐effects. On a number of complex tests of memory function, there was no difference between the patients receiving low‐dose versus high‐dose Hydergine. There were also no significant between‐group differences in recognition memory, incidental memory, naming ability, figure drawing, mood or other psychiatric symptoms. These data confirm that Hydergine is safe and that trials in a low dosage range may suffice.
Idiopathic basal ganglia calcification presenting as hypomania
Authors: Wylie Kevan R. , Harris Stephen J. 
Published: January 2005

AbstractA sixty‐four‐year‐old lady manifested a hypomanic psychosis and later developed features of a subcortical dementia and movement disorders of Parkinsonism and chorea. Computerized tomography revealed bilateral basal ganglia calcification. No evidence of parathyroid disorder or any other cause for the calcification was present. There has been only one previously reported case of organic mood disorder of a manic type presentation of idiopathic basal ganglia calcification (IBGC). The oldest reported age of onset of IBGC presenting with psychosis is 53 years and with dementia is 68 years.
Acetyl‐L‐Carnitine in dementia
Authors: Livingston G. A. , Sax K. B. , McClenahan Z. , Blumenthal E. , Foley K. , Willison J. , Mann A. H. , James I. M. 
Published: January 2005

AbstractThis study was designed to test the benefit of acetyl‐l‐carnitine in patients with dementia. Seventy‐one patients of 65 years and over, living in their own homes or in residential care, took part in a 24‐week randomized, double‐blind, placebo‐controlled, parallel‐group clinical trial. The outcome was measured by comparing psychometric tests at 24 weeks to baseline measures. The active treatment group improved in mean scores in seven out of eight psychometric in one test. recognition memory (P>0.01). Linear discriminant function analysis indicated that active and placebo therapy could be distinguished according to the pattern of responses to the eight psychological test (p>0.01). In this small trial, acetyl‐l‐carnitine was shown to be non‐toxic and possibly beneficial. Further large‐scale trials are needed over long periods of time.
An audit of the use of antipsychotics in a geriatric psychiatry continuing care unit in Scotland
Authors: Connelly Pete R. J. 
Published: January 2005

AbstractBehaviour problems, dependency levels and use of antipsychotic medication were assessed, using an audit approach, in 104 patients in a geriatric psychiatry continuing care unit. High levels of dependency and behaviour disturbance were found. 37.5% of the population were receiving regular antipsychotic medication. The severity of a cluster of four symptoms (diurnal restlessness, agitation, irritability and active aggression) tended to discriminate this group from those on no antipsychotics, though frequency of problems and total number of problems were also higher in the group on regular antipsychotics. Antidepressants were rarely used, though conversely there was only one case of ‘missed’ depression. Changes following the audit are described and recommendations for improved monitoring of medication use are made.
Quantal components of the synaptic potential induced in hippocampal neurons by activation of granule cells, and the effect of 2‐amino‐4‐phosphonobutyric acid
Authors: Yamamoto Chosaburo , Higashima Masato , Sawada Satsuki , Kamiya Haruyuki 
Published: January 2005

AbstractThe probabilistic nature of excitatory postsynaptic potentials (EPSPs) induced monosynaptically in CA3 neurons by impulses of granule cells was studied in thin transverse sections of the guinea pig hippocampus. More than 600 EPSPs were recorded under several conditions, their amplitudes were measured, and histograms representing the EPSP amplitude distribution were constructed. Quantal parameters were estimated by the method of maximum likelihood. Of 9 neurons examined in the control solution, one neuron showed an exceptionally large number of transmission failures. The amplitude distribution of EPSPs recorded from this neuron could be described by Pascal statistics, but not by binomial or Poisson statistics. The EPSP amplitude distribution from the other neurons could be described by either binomial, Poisson, or Pascal predictions with a minor preference for the last statistic. When an apparently homogeneous group of data was divided into two subgroups and parameters were estimated separately, inconsistent values were obtained in some neurons with no failures. 2‐Amino‐4‐phosphonobutyric acid (APB) suppressed the EPSPs reversibly at relatively low concentrations. Theoretical curves calculated according to the Pascal statistics fit quite well to the entire amplitude distribution of EPSPs recorded under the action of APB. The suppression of EPSPs by APB was accompanied by a marked decrease in mean quantal content (m) with no significant reduction in mean quantal amplitude (q). A quantum induced an increase in membrane conductance of about 150 pS. These results suggest that the release probability of the mossy fiber terminal fluctuates temporally according to a gamma distribution, and that APB reduces the liberation of the transmitter from mossy fiber terminals, thereby suppressing transmission between mossy fibers and CA3 neurons.