bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fas (CD95/APO‐1) and Fas ligand expression in normal pancreas and pancreatic tumors
Authors: Bernstorff Wolfram V. , Glickman Jonathan N. , Odze Robert D. , Farraye Francis A. , Joo Hong G. , Goedegebuure Peter S. , Eberlein Timothy J. 
Published: August 2002

AbstractBACKGROUNDFas (CD95/APO‐1) and Fas ligand (FasL) play key roles in immunologic homeostasis and immune privilege and may regulate normal cell turnover. Earlier studies had suggested that FasL‐positive pancreatic carcinoma cell lines can induce apoptosis in T cells, thereby evading host immune surveillance. In the current study the authors have characterized the expression of Fas and FasL in the normal pancreas and in pancreatic neoplasia.METHODSPancreatic resection specimens with ductal‐type adenocarcinoma or intraductal dysplasia (n = 41), nonductal pancreatic neoplasms (n = 5), and chronic pancreatitis (n = 4) were examined for Fas and FasL expression by immunohistochemistry. The results in invasive adenocarcinoma were compared to those for benign ducts and intraductal dysplasia, and correlated with clinicopathologic features of the tumors and with patient survival.RESULTSFas was expressed in the normal pancreatic ducts and in intraductal dysplasia in a mixed membrane/cytoplasmic pattern. In all cases of invasive ductal‐type adenocarcinoma, membranous Fas could not be detected; cytoplasmic Fas staining was reduced or completely lost. Loss of Fas expression in pancreatic ductal‐type adenocarcinomas significantly correlated with poorer differentiation and extrapancreatic spread of the tumors and was associated with a shorter overall survival. FasL expression was present in the normal pancreatic ducts as well as in islet cells and was maintained in all pancreatic tumors.CONCLUSIONSThese results implicate the Fas pathway in the regulation of physiologic cell turnover and immune privilege in the normal pancreas and indicate that loss of Fas expression is correlated with malignant transformation and biologic aggressiveness in pancreatic adenocarcinomas. This may represent a mechanism by which pancreatic tumor cells become resistant to apoptosis and escape immune surveillance in vivo. Cancer 2002;94:2552–60. © 2002 American Cancer Society.DOI 10.1002/cncr.10549
Functional circuitry involved in the regulation of whisker movements
Authors: Hattox Alexis M. , Priest Catherine A. , Keller Asaf 
Published: August 2002

AbstractNeuroanatomical tract‐tracing methods were used to identify the oligosynaptic circuitry by which the whisker representation of the motor cortex (wMCx) influences the facial motoneurons that control whisking activity (wFMNs). Injections of the retrograde tracer cholera toxin subunit B into physiologically identified wFMNs in the lateral facial nucleus resulted in dense, bilateral labeling throughout the brainstem reticular formation and in the ambiguus nucleus as well as predominantly ipsilateral labeling in the paralemniscal, pedunculopontine tegmental, Kölliker‐Fuse, and parabrachial nuclei. In addition, neurons in the following midbrain regions projected to the wFMNs: superior colliculus, red nucleus, periaqueductal gray, mesencephalon, pons, and several nuclei involved in oculomotor behaviors. Injections of the anterograde tracer biotinylated dextran amine into the wMCx revealed direct projections to the brainstem reticular formation as well as multiple brainstem and midbrain structures shown to project to the wFMNs. Regions in which retrograde labeling and anterograde labeling overlap most extensively include the brainstem parvocellular, gigantocellular, intermediate, and medullary (dorsal and ventral) reticular formations; ambiguus nucleus; and midbrain superior colliculus and deep mesencephalic nucleus. Other regions that contain less dense regions of combined anterograde and retrograde labeling include the following nuclei: the interstitial nucleus of medial longitudinal fasciculus, the pontine reticular formation, and the lateral periaqueductal gray. Premotoneurons that receive dense inputs from the wMCx are likely to be important mediators of cortical regulation of whisker movements and may be a key component in a central pattern generator involved in the generation of rhythmic whisking activity. J. Comp. Neurol. 442:266–276, 2002. © 2001 Wiley‐Liss, Inc.
Upregulation of Kv 1.4 protein and gene expression after chronic spinal cord injury
Authors: Edwards Lori , Nashmi Raad , Jones Owen , Backx Peter , Ackerley Cameron , Becker Larry , Fehlings Michael G. 
Published: August 2002

AbstractAfter spinal cord injury (SCI), white matter tracts are characterized by demyelination and increased sensitivity to the K+ channel blocker 4‐aminopyridine (4‐AP). These effects appear to contribute to neurological impairment after SCI, although the molecular changes in K+ channel subunit expression remain poorly understood. We examined changes in gene expression of the 4‐AP‐sensitive voltage‐gated K+ channel Kv 1.4 after chronic SCI in the rat. Quantitative immunoblotting showed that Kv 1.4 protein was significantly increased at 6 weeks, but not at 1 week, after SCI in spinal cord white matter. Kv 1.4 was localized to astrocytes, oligodendrocytes, and oligodendrocyte progenitor cells but not to axons in both the normal and the injured spinal cord white matter. Because glial cells proliferate after SCI, we used immunogold electron microscopy to quantify Kv 1.4 protein in individual glial cells and found a sixfold increase of Kv 1.4 in cells of the oligodendrocyte lineage after chronic injury. Finally, quantitative in situ hybridization showed that Kv 1.4 mRNA was significantly upregulated in spinal cord white matter, but not gray matter, after SCI. In summary, we show that Kv 1.4 is expressed in glial cells and not in axons in the rat spinal cord white matter and that its expression is markedly increased in cells of the oligodendrocyte lineage after chronic SCI. Given that K+ channels play a role in glial cell proliferation, cells exhibiting changes in Kv 1.4 expression may represent proliferating oligodendroglia in the chronically injured spinal cord. J. Comp. Neurol. 443:154–167, 2002. © 2002 Wiley‐Liss, Inc.
Differential distribution of spermidine/spermine‐like immunoreactivity in neurons of the adult rat brain
Authors: Laube Gregor , Bernstein Hans‐Gert , Wolf Gerald , Veh Rüdiger W. 
Published: August 2002

AbstractThe polyamines spermidine and spermine are small, widely distributed polycations. In the brain, they confer rectification properties upon inwardly rectifying potassium channels and Ca2+‐permeable α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole‐propionate (AMPA)/kainate receptors and also modify functional properties of N‐methyl‐D‐aspartate receptors. Therefore, functional roles of spermidine/spermine in the adult brain will depend on the colocalization of the spermidine/spermine‐sensitive receptors/channels and the polyamines either in the same or in closely associated cell types. We previously immunocytochemically demonstrated a prominent localization of spermidine/spermine in glial cells, especially astrocytes (Laube and Veh [ 1997] Glia 19:171–179). In contrast to the commonly accepted assumption of a ubiquitous distribution of polyamines in various cell types, in neurons of the rat brain, we detected a highly diverse spermidine/spermine‐like immunoreactivity. The immunoreactivity in neurons and neuropil throughout the rat brain is listed according to intensity in arbitrary groups. The strongest neuronal staining was observed in the hypothalamic paraventricular, supraoptic, and accessory neurosecretory nuclei. Strong cytoplasmic staining was also evident in some motor and somatosensory areas such as the Me5 nucleus of the mesencephalic trigeminal tract, the nucleus ruber, and the large motor neurons of the spinal cord ventral horn. In contrast, in most cortical and hippocampal regions spermidine/spermine‐like immunoreactivity in neurons was relatively weak, whereas in these areas, the labeling pattern was dominated by a diffuse neuropil labeling. In addition to spermidine/spermine immunocytochemistry, ornithine decarboxylase labeling was performed and the resulting labeling patterns were compared. The prominent localization of spermidine/spermine in neurosecretory neurons might point to a functional role different from channel/receptor modification. In these neurons, polyamines might be involved in secretory processes. J. Comp. Neurol. 444:369–386, 2002. © 2002 Wiley‐Liss, Inc.
Mast cells in Wallerian degeneration: Morphologic and ultrastructural changes
Authors: Esposito Barbara , De Santis Amedeo , Monteforte Rossella , Baccari Gabriella Chieffi 
Published: August 2002

AbstractThe morphologic and ultrastructural changes of mast cells were followed in degenerating distal and regenerating proximal stumps of frog brachial nerve during Wallerian degeneration. Quantitative analysis included determination of both number and size of mast cells. The mast cell response to injury consisted of an early and a late phase. In the early phase, there was an increase in mast cell numbers in the proximal site of the lesion and a release of Alcian blue material consistent with mediator release. This phase of mast cell activation may be related, through the secretion of biogenic agents such as heparin and histamine, to the increase of endoneurial vessel size and vascular permeability, providing access for macrophages and mast cell precursors. The later phase, which peaked at 40 days after transection in the degenerating distal stump, consisted in the degranulation of the mast cells. These mast cells, closely associated with macrophages and degenerating Schwann cells, released secretory granules into the endoneurial microenvironment. These degranulating mast cells, through the released acid hydrolases, may contribute along with macrophages and Schwann cells, to the degradation of myelin debris. At the same time, mast cells appeared filled with granular content in the regenerating proximal segment. Therefore, we suggest that mast cells in peripheral nerves may play an important role in nerve degenerating and regenerating mechanisms through the secretion of diffusible molecules. J. Comp. Neurol. 445:199–210, 2002. © 2002 Wiley‐Liss, Inc.
Distribution and synaptic connectivity of neuropeptide Y‐immunoreactive amacrine cells in the rat retina
Authors: Oh Su‐Ja. , D'Angelo Iona , Lee Eun‐Jin , Chun Myung‐Hoon , Brecha Nicholas C. 
Published: August 2002

AbstractNeuropeptide Y (NPY) is a potent bioactive peptide that is widely expressed in the nervous system, including the retina. Here we show that specific NPY immunoreactivity was localized to amacrine and displaced amacrine cells in the rat retina. Immunoreactive cells had a regular distribution across the retina and an overall cell density of 280 cells/mm2 in the inner nuclear layer (INL) and 90 cells/mm2 in the ganglion cell layer (GCL). In the INL, most immunoreactive cells were characterized by small cell bodies and fine processes that appeared to ramify primarily in stratum 1 of the inner plexiform layer (IPL). A few cells in the INL also ramified in stratum 3 of the IPL. In the GCL, small to medium immunoreactive cells appeared to ramify primarily in stratum 5 of the IPL. A few immunoreactive processes, originating from somata in the INL and processes in the IPL, ramified in the OPL. NPY‐immunoreactive cells contained GABA immunoreactivity, and some amacrine cells also contained tyrosine hydroxylase immunoreactivity. NPY‐immunostained processes were most frequently presynaptic to nonimmunostained amacrine and ganglion cell processes and postsynaptic to nonimmunostained amacrine cell processes and cone bipolar cell axonal terminals. These findings indicate that NPY immunoreactivity is present in two populations of amacrine cells, one located in the INL and the other in the GCL, and that these cells mainly form synaptic contacts with other amacrine cells. These observations suggest that NPY‐immunoreactive cells participate in multiple circuits mediating visual information processing in the inner retina. J. Comp. Neurol. 446:219–234, 2002. © 2002 Wiley‐Liss, Inc.
Retinofugal projections in the short‐tailed opossum (Monodelphis domestica)
Authors: Kahn Dianna M. , Krubitzer Leah 
Published: August 2002

AbstractIn the current investigation, retinofugal projections to midbrain and thalamic nuclei of Monodelphis domestica were investigated using wheat‐germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP). Large intraocular injections of WGA‐HRP were placed into the eye, and patterns of labeled axon terminals were related to nuclear boundaries in tissue that was stained for Nissl or reacted for cytochrome oxidase (CO). Our results demonstrate that the major projection from the retina is to the contralateral dorsal lateral geniculate nucleus (LGNd) and the superior colliculus (SC). Connections were also observed with the contralateral pretectal nucleus (PRT), the lateral posterior nucleus (LP), and the ventral division of the lateral geniculate nucleus (LGNv). Ipsilateral connections were with the LGNv and LGNd. These findings are consistent with reports in other marsupials as well as with studies in a number of eutherian mammals. Thus, there appears to be a common pattern of retinofugal projections that all mammals share, probably due to retention from a common ancestor. However, some features such as a lack of ipsilateral input to the SC (which are absent only in certain species like Monodelphis, platypus, and echidnas) may represent a primitive state retained from a common ancestor. When comparisons of retinofugal connections and LGNd organization are made across taxa, three types of organization are observed: a homogenous LGNd with a high degree of binocular overlap of projections; a partially differentiated LGNd with some segregation of eye‐specific inputs; and a fully segregated structure with a large degree of segregation of eye‐specific inputs. We discuss the factors that contribute to the organization observed in extant mammals and conclude that phylogeny and lifestyle appear to be the underlying factors contributing to the organization of the LGNd. J. Comp. Neurol. 447:114–127, 2002. © 2002 Wiley‐Liss, Inc.
Developmental regulation of CPG15 expression in Xenopus
Authors: Nedivi Elly , Javaherian Ashkan , Cantallops Isabel , Cline Hollis T. 
Published: August 2002

AbstractMechanisms controlling dendritic arbor formation affect the establishment of neuronal circuits. Candidate plasticity gene 15 (CPG15) is a glycosylphosphatidyl inositol (GPI)‐linked activity‐induced protein that has been shown to function as an intercellular signaling molecule that can promote the morphological and physiological development of the Xenopus retinotectal system. A thorough understanding of CPG15 function requires knowledge of the spatiotemporal expression of the endogenous protein. We therefore cloned Xenopus cpg15 and used RNA in situ hybridization and immunohistochemistry to determine the pattern of CPG15 expression. cpg15 mRNA and CPG15 protein are first detectable in the developing spinal cord and become widespread as development proceeds. CPG15 is expressed in sensory regions of the brain, including the visual, auditory, and olfactory systems. Within the retina, CPG15 is only expressed in retinal ganglion cells. CPG15 protein is concentrated in axon tracts, including retinal axons. These data support a model in which CPG15 expressed in retinal ganglion cells is trafficked to retinal axons, where it modulates postsynaptic dendritic arbor elaboration, and synaptic maturation. J. Comp. Neurol. 435:464–473, 2001. © 2001 Wiley‐Liss, Inc.
Postnatal regulation of limb proprioception by muscle‐derived neurotrophin‐3
Authors: Taylor Michael D. , Vancura Ryan , Patterson Colleen L. , Williams Janelle M. , Riekhof John T. , Wright Douglas E. 
Published: August 2002

AbstractTo investigate the effects of neurotrophin‐3 (NT‐3) on postnatal proprioceptive neurons and their targets, transgenic mice were generated that use the myosin light chain 1 (mlc) promoter to overexpress NT‐3 in skeletal muscle. Ribonuclease protection assays revealed that NT‐3 overexpression in hindlimb skeletal muscle began at embryonic day 14 (E14) and continued throughout adulthood. Overexpression of NT‐3 during late embryogenesis resulted in increased numbers of large sensory and small fusimotor axons. Within a week of birth, mlc/NT‐3 mice retract their limbs to the torso when lifted by the tail. Footprint analysis revealed that mlc/NT‐3 mice had significant abnormalities in their gait compared with wild‐types. Beam walking and rotorod analysis confirmed the poor limb control by mlc/NT‐3 mice. These locomotive deficits progressively worsened with age and were likely related to the formation of morphologically abnormal muscle spindles. The most common spindle anomaly was the presence of excessive intrafusal bag fibers within individual muscle spindles. To assess the role of NT‐3 in recovery from nerve injury, sciatic nerve crushes were performed in young adult mice. Two days after injury, mlc/NT‐3 mice displayed significantly improved sciatic functional indexes and a significant increase in muscle spindles that remained associated with axons. The latter finding suggests that excess NT‐3 in muscle may retard the degeneration of proprioceptive axons after nerve crush. Long‐term survival after nerve injury in mlc/NT‐3 mice did not induce further changes in spindle number or morphology. These findings demonstrate that, in addition to promoting embryonic proprioceptive neuron survival, postnatal overexpression of NT‐3 in muscle leads to abnormal spindle formation and deficits in locomotive control. However, our results also show that NT‐3 may be therapeutic for proprioceptive axons immediately after nerve injury by delaying axon degeneration. J. Comp. Neurol. 432:244–258, 2001. © 2001 Wiley‐Liss, Inc.
Brevican in the developing hippocampal fimbria: Differential expression in myelinating oligodendrocytes and adult astrocytes suggests a dual role for brevican in central nervous system fiber tract development
Authors: Ogawa Tokiko , Hagihara Kazuki , Suzuki Mitsuru , Yamaguchi Yu 
Published: August 2002

AbstractBrevican is one of the most abundant extracellular matrix proteoglycans in the mammalian brain. We have previously shown that brevican produced by gray matter astrocytes constitutes a major component of perineuronal extracellular matrix in the adult brain. In this paper, we investigate the expression of brevican in the postnatal hippocampal fimbria to explore the role of the proteoglycan in central nervous system fiber tract development. We demonstrate that brevican is expressed by both oligodendrocytes and white matter astrocytes in the fimbria, but the expression of brevican in these two glial cell types is differently regulated during development. At P14, brevican immunoreactivity was observed throughout the fimbria, with particularly strong immunoreactivity in the developing interfascicular glial rows. In situ hybridization showed that oligodendrocytes in the glial rows strongly express brevican during the second and third postnatal weeks. Expression in oligodendrocytes was then down‐regulated after P21. In the adult fimbria, no brevican expression was observed in oligodendrocytes. The time window of brevican expression coincides with the phase in which immature oligodendrocytes actively extend membrane processes and enwrap axon fibers. In contrast, the expression in astrocytes started around P21 as oligodendrocytes began to down‐regulate the expression. In the adult fimbria, brevican expression was restricted to astrocytes. In situ hybridization with isoform‐specific probes and RNase protection assays showed that the authentic, secreted form of brevican, not the glycosylphosphatidylinositol‐anchored variant, is the predominant species expressed in the developing fimbria. Our results suggest that brevican plays a dual role in developing and adult fiber tracts. J. Comp. Neurol. 432:285–295, 2001. © 2001 Wiley‐Liss, Inc.
Characterization of neuropeptide Y–expressing cells in the mouse retina using immunohistochemical and transgenic techniques
Authors: Sinclair John Robert , Nirenberg Sheila 
Published: August 2002

AbstractThe amacrine cells of the retina are a complex family of interneurons. They are made up of numerous subgroups, each with different morphologic and/or biochemical properties and each presumably serving a different function. In this study, we characterized one subgroup, defined by its expression of a peptide, neuropeptide Y (NPY). The cells were identified using antibodies to NPY and characterized using a transgenic mouse line that expressed the reporter enzyme, β‐galactosidase, in the NPY‐immunoreactive (NPY‐IR) cells. We found that NPY‐IR cells were present in two layers, the inner nuclear layer (INL) and the ganglion cell layer (GCL). The cells in both layers were densely distributed, with those in the INL having a mean density of 1452 ± 65 cells/mm2, and those in the GCL having a mean density of 644 ± 41 cells/mm2. The cells in the INL extended their processes in the sublamina of the inner plexiform layer (IPL) closest to the INL/IPL border, the presumptive OFF sublamina, and the cells in the GCL extended their processes in the sublamina near the GCL/IPL border, the presumptive ON sublamina. Both populations of cells were immunoreactive to a GABA transporter and, thus, likely GABAergic. The high density of these cells suggests that they play a prominent role in IPL processing. The location of their processes suggests that one population acts in the pathway that mediates OFF responses, and the other in the pathway that mediates ON responses, and their expression of a GABA marker indicates that their actions are likely inhibitory. J. Comp. Neurol. 432:296–306, 2001. © 2001 Wiley‐Liss, Inc.
Structure and projections of white matter neurons in the postnatal rat visual cortex
Authors: Clancy Barbara , Silva‐Filho Manoel , Friedlander Michael J. 
Published: August 2002

AbstractTransient contributions of subplate neurons to the initial development of the cortex are well‐characterized, yet little data are available on a subpopulation of subplate neurons that persist in the white matter (WM) of the cerebral cortex across development. To characterize the WM neurons, differential interference contrast and Nomarski optics were used to visualize individual cells in the WM in slices of rat visual cortex at postnatal ages 9–23. Soma‐dendritic morphology and local axonal projection patterns, including probable synaptic innervation sites of their axons, were identified by intracellular filling with biocytin during electrophysiologic recordings. Dendritic branches of all WM neurons, tripartitioned here into upper, middle, and deep divisions, extend throughout the WM and frequently into the overlying cortex. Axonal arborizations from most WM neurons, including apparent boutons, project into adjacent WM with many also innervating overlying cortical layers, whereas some project into the stratum oriens/alveus of the hippocampal formation. Processes of a subset of WM neurons appear to be confined to the WM itself. By using antimicrotubule associated protein (MAP2) immunostaining to quantify the density of WM neurons in rat visual cortex, we find that their overall numbers decrease to approximately 30% of initial levels during postnatal development. During this same developmental period, an increasing percentage of WM neurons contain the synthetic enzyme for nitric oxide, nitric oxide synthase (NOS), as evaluated by immunostaining. Thus, WM neurons that survive the initial perinatal period of cell death are positioned under the laminae of the maturing cortex to potentially modulate the integration of visual signals through either conventional synaptic or nonconventional (diffusible NO signaling) mechanisms. J. Comp. Neurol. 434:233–252, 2001. © 2001 Wiley‐Liss, Inc.