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Pollard H, Ward G. The effect of upper cervical or sacroiliac manipulation on hip flexion range of motion. J Manipulative Physiol Ther 1998; 21:611-6. [PMID: 9868632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
OBJECTIVES To compare the effectiveness of an upper cervical manipulation and a manipulation of the sacroiliac joint for increasing hip range of motion. DESIGN Clinical cohort study. SETTING Macquarie University Centre for Chiropractic Outpatient Clinic. SAMPLE Fifty-two randomly chosen university students aged 18 to 34 yr. METHOD A reliable hand-held dynamometer was used to determine the end point of range of motion before and after the application of a treatment. Three groups of subjects were created: cervical manipulation, sacroiliac manipulation and sham/placebo. Range of motion of the hip in flexion (SLR) was used as the independent variable. RESULTS The two manipulative treatments resulted in increased flexion range of motion at the hip. Statistical analysis revealed that only the upper cervical manipulation procedure increased hip flexion range of motion significantly. CONCLUSION The results suggest that manual therapy of the neck may affect hip range of motion in normal adults. Findings such as these may indicate the existence of a link between the cervical spine and the lower extremity.
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Pollard H, Remy JS, Loussouarn G, Demolombe S, Behr JP, Escande D. Polyethylenimine but not cationic lipids promotes transgene delivery to the nucleus in mammalian cells. J Biol Chem 1998; 273:7507-11. [PMID: 9516451 DOI: 10.1074/jbc.273.13.7507] [Citation(s) in RCA: 493] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta-galactosidase reporter gene, either free or complexed with various cationic vectors, was microinjected into mammalian cells. Cationic lipids but not polyethylenimine or polylysine prevent transgene expression when complexes are injected in the nucleus. Polyethylenimine and to a lesser extent polylysine, but not cationic lipids, enhance transgene expression when complexes are injected into the cytoplasm. This latter effect was independent of the polymer vector/cDNA ionic charge ratio, suggesting that nucleic acid compaction rather than surface charge was critical for efficient nuclear trafficking. Cell division was not required for nuclear entry. Finally, comparative transfection and microinjection experiments with various cell lines confirm that barriers to gene transfer vary with cell type. We conclude that polymers but not cationic lipids promote gene delivery from the cytoplasm to the nucleus and that transgene expression in the nucleus is prevented by complexation with cationic lipids but not with cationic polymers.
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Demolombe S, Baró I, Péréon Y, Bliek J, Mohammad-Panah R, Pollard H, Morid S, Mannens M, Wilde A, Barhanin J, Charpentier F, Escande D. A dominant negative isoform of the long QT syndrome 1 gene product. J Biol Chem 1998; 273:6837-43. [PMID: 9506986 DOI: 10.1074/jbc.273.12.6837] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the KvLQT1 gene are the cause of the long QT syndrome 1. KvLQT1 gene product is associated with the regulator protein IsK to produce a component of the delayed rectifier K+ current in cardiac myocytes. We identified an N-terminal truncated isoform of the KvLQT1 gene product, referred to as isoform 2. In RNase protection assays, isoform 2 represented 28.1 +/- 0.6% of the total KvLQT1 expression in the human adult ventricle. COS-7 cells injected intranuclearly with KvLQT1 isoform 1 cDNA exhibited a fast-activating K+ current, whereas those injected with a KvLQT1 isoform 1 plus IsK cDNA showed a slow-activating K+ current. Cells injected with KvLQT1 isoform 2 plasmid showed no detectable K+ current. Those injected with a 1/1 isoform 2/isoform 1 ratio showed no detectable K+ current. Those injected with 1/5 and 2/5 ratios showed a K+ current with markedly reduced amplitude. Coexpression of the IsK regulator consistently reduced the dominant negative effects of isoform 2. Our results indicate that KvLQT1 isoform 2 exerts a pronounced negative dominance on isoform 1 channels and that the cardiac KvLQT1 K+ channel complex is composed of at least three different proteins as follows: isoform 1, isoform 2, and IsK.
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Mohammad-Panah R, Demolombe S, Riochet D, Leblais V, Loussouarn G, Pollard H, Baró I, Escande D. Hyperexpression of recombinant CFTR in heterologous cells alters its physiological properties. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:C310-8. [PMID: 9486119 DOI: 10.1152/ajpcell.1998.274.2.c310] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We investigated whether high levels of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) would alter the functional properties of newly synthesized recombinant proteins. COS-7, CFPAC-1, and A549 cells were intranuclearly injected with a Simian virus 40-driven pECE-CFTR plasmid and assayed for halide permeability using the 6-methoxy-N-(3-sulfopropyl)quinolinium fluorescent probe. With increasing numbers of microinjected pECE-CFTR copies, the baseline permeability to halide dose dependently increased, and the response to adenosine 3',5'-cyclic monophosphate (cAMP) stimulation decreased. In cells hyperexpressing CFTR, the high level of halide permeability was reduced when a cell metabolism poisoning cocktail was applied to decrease intracellular ATP and, inversely, was increased by orthovanadate. In CFPAC-1 cells investigated with the patch-clamp technique, CFTR hyperexpression led to a time-independent nonrectifying chloride current that was not sensitive to cAMP stimulation. CFPAC-1 cells hyperexpressing CFTR exhibited no outward rectifying chloride current nor inward rectifying potassium current either spontaneously or under cAMP stimulation. We conclude that hyperexpression of recombinant CFTR proteins modifies their properties inasmuch as 1) CFTR channels are permanently activated and not susceptible to cAMP regulation and 2) they lose their capacity to regulate heterologous ionic channels.
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Stephens D, Bilton D, Pollard H, Gorman F. Wall perimetry in chiropractic. J Manipulative Physiol Ther 1998; 21:32-6. [PMID: 9467099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Wall perimetry is a method of examination that led to the initial appreciation of the "tunnel vision information." The visual field loss that wall perimetry indicates generally defines the overall characteristics of the dysfunction associated with 'tunnel vision.' Wall perimetry is an inexpensive, yet sensitive, preliminary screening test for perception abnormality in the outermost periphery of vision. OBJECTIVE To describe wall perimetry. The term "wall perimetry" denotes a simple preliminary method of examining the visual fields of chiropractic patients. DISCUSSION The test is described with reference to photographs. The patient stands 1 m from the corner of a room and is instructed to look directly at the junction of the walls, with the head remaining still and gaze fixed. Standing behind the patient, the examiner projects a target of light onto the wall and moves it until it is seen by the subject. CONCLUSION Chiropractors are encouraged to test appropriate patients by wall perimetry before spinal manipulation therapy. On the basis of existing experience, detection of patients with visual field loss is to be expected. From that point, formal examination of the visual fields using kinetic or static perimetry apparatus is recommended to further verify the "tunnel vision" discovery.
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Collet J, Fehrat L, Pollard H, Ribas de Pouplana L, Charton G, Bernard A, Moreau J, Ben-Ari Y, Khrestchatisky M. Developmentally regulated alternative splicing of mRNAs encoding N-terminal tau variants in the rat hippocampus: structural and functional implications. Eur J Neurosci 1997; 9:2723-33. [PMID: 9517477 DOI: 10.1111/j.1460-9568.1997.tb01701.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tau protein variants are axonal microtubule-associated phosphoproteins whose expression correlates with developmentally regulated neurite outgrowth. A single gene encodes multiple tau transcripts via complex alternative splicing. We studied the expression of the mRNAs encoding N-terminal variants of tau, and we showed distinct alternative splicing of exons 2 and 3 in nervous tissues of the adult rat, including the inner ear, hippocampus, cortex, striatum, brainstem, cerebellum, olfactory bulb and retina. Using the reverse transcriptase-coupled polymerase chain reaction and in situ hybridization, we then focused our developmental study on hippocampal neurons, both in vivo and in vitro, to address the developmental and spatial expression of the alternatively spliced mRNAs encoding N-terminal variants of tau. Tau mRNAs devoid of exons 2 and 3 were present throughout development, although their levels decreased in adults. Those containing exon 2 but not exon 3 were already present in the hippocampus of newborn rats and their levels increased during the first postnatal week, mainly in the pyramidal cell layer. Tau RNAs containing exons 2 and 3 appeared at the end of this period in the pyramidal cell layer and in the dentate granule cells. Exon 2-containing mRNAs seemed to be associated with cells undergoing axonal sprouting, while exon 3-containing RNAs were expressed in mature neurons that had established their connections. The timing and pattern of tau alternative splicing were maintained in cultured hippocampal neurons, suggesting that splicing processes are independent of the organized connectivity and of the environmental cues provided in vivo. Secondary structure predictions of tau variants revealed that the insertion of the exon 3-encoded domain substantially modifies the secondary structure of the N-terminal region of tau. This N-terminal heterogeneity may confer distinct regulatory roles on the tau variants during ontogeny and may contribute to plasticity in the adult rat brain.
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Pollard H, Bugra K, Khrestchatisky M, Represa A, Ben-Ari Y. Seizure-induced molecular changes, sprouting and synaptogenesis of hippocampal mossy fibers. EPILEPSY RESEARCH. SUPPLEMENT 1997; 12:355-63. [PMID: 9302535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Pollard H, Ward G. A study of two stretching techniques for improving hip flexion range of motion. J Manipulative Physiol Ther 1997; 20:443-7. [PMID: 9310898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To compare the effectiveness of a spinal (suboccipital) stretching technique and a peripheral stretching technique. DESIGN Clinical cohort study. SETTING Macquarie University Centre for Chiropractic Outpatient Clinic. METHOD A reliable hand-held dynamometer was used to determine the end point of range of motion (ROM) before and after the application of a treatment. Three groups of subjects were treated: cervical stretch, hip stretch and sham/placebo. ROM of the hip in flexion (straight leg raise) was used as the independent variable. SAMPLE Sixty randomly allocated university students aged between 18 and 35 yr. RESULTS The two stretching treatments resulted in increased flexion ROM at the hip. Statistical analysis revealed that only the sub-occipital stretching procedure increased hip flexion ROM significantly. CONCLUSION Manual therapy of the neck may have a role to play in the treatment of extraspinal, lower-limb musculoskeletal conditions.
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Gelot A, Moreau J, Ben Ari Y, Pollard H. Alpha-brain spectrin mRNA belongs to the population of intradendritically transported mRNAs. Neuroreport 1996; 8:113-6. [PMID: 9051763 DOI: 10.1097/00001756-199612200-00023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Brain spectrin is a cytoskeletal protein involved in neuronal polarization and differentiation. We have studied the intraneuronal expression of non-erythroid (NE) alpha-spectrin mRNA in the rat brain during the development of the CA3 pyramidal cells, and compared it with alpha-tubulin mRNA expression. In contrast to alpha-tubulin expression, which remains located in the neuronal somata, NE alpha-spectrin mRNA was present in the dendritic compartment during the first 2 weeks of life. NE alpha-Brain spectrin mRNA transport into the dendrites coincides with critical development events, including dendritic arborization, growth and synaptogenesis, and could be dependent on the appearance of synaptic activity at the mossy fibre/CA3 synapse.
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Tardif JC, Pandian NG, Freire M, Cao QL, Pollard H. On-line echocardiographic assessment of hemodynamic indexes by an adaptive Doppler analysis algorithm and signal/noise ratio calculation. J Am Soc Echocardiogr 1996; 9:9-17. [PMID: 8679242 DOI: 10.1016/s0894-7317(96)90099-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Assessment of cardiac diseases commonly involves the use of spectral Doppler echocardiography. Its use, however, often requires manual digitization of various transvalvular flow profiles. A new approach has been developed for on-line analysis of Doppler data, which involves thresholding based on the signal/noise ratio, calculating instantaneous values, and plotting on the spectral display in real time. We examined the reliability of this new method in 32 patients with 59 various flow jets by comparing it with the data derived by manual analysis. Correlations between the algorithm analysis and manual analysis for peak velocity, peak gradient, velocity-time integral, and acceleration time were excellent. These indexes were obtained with the algorithm in a shorter time and with better reproducibility than with manual analysis. Thus this new adaptive Doppler analysis algorithm yields reliable on-line quantification of valuable hemodynamic variables and represents an advance in quantitative echocardiography.
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Pollard H, Moreau J, Aubourg P. Localization of mRNAs for adrenoleukodystrophy and the 70 kDa peroxisomal (PMP70) proteins in the rat brain during post-natal development. J Neurosci Res 1995; 42:433-7. [PMID: 8583512 DOI: 10.1002/jnr.490420318] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Adrenoleukodystrophy (ALD) is a genetic demyelinating disorder caused by the mutation of a gene encoding a 75-kDa peroxisomal protein (ALDP) that belongs to the superfamily of ATP binding casette (ABC) transporters. The PMP 70 gene codes for another peroxisomal ABC transporter that shows 38.5% amino acid identity with ALDP. ALDP and PMP70 have the structure of half transporter and could possibly heterodimerize to form a full transporter within the peroxisomal membrane. Using in situ hybridization histochemistry in rat brain, we demonstrate that ALD and PMP70 mRNAs have different spatial and temporal expression during postnatal development. Whereas expression of PMP 70 mRNA was low at birth and culminates between the 2nd and 3rd week in hippocampus and cerebellum, maximum expression of ALDP was found at birth in all brain areas and decreased thereafter. The absence of coordinated expression of ALD and PMP70 genes suggests therefore that ALD and PMP70 proteins are unlikely to function as exclusive and obligatory partners in the brain.
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Dessi F, Pollard H, Moreau J, Ben-Ari Y, Charriaut-Marlangue C. Cytosine arabinoside induces apoptosis in cerebellar neurons in culture. J Neurochem 1995; 64:1980-7. [PMID: 7536801 DOI: 10.1046/j.1471-4159.1995.64051980.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cytosine arabinoside (AraC) is a pyrimidine antimetabolite that prevents cell proliferation by inhibiting DNA synthesis. We report that AraC kills cultured cerebellar neurons in a concentration-dependent fashion with an EC50 of approximately 60 microM when added shortly after seeding. This cell death has apoptotic features because we observed (1) morphology of apoptotic nuclei as judged by DNA staining with Hoechst 33258, (2) DNA fragmentation with typical ladder pattern on agarose gel, (3) positive nuclear labeling with a specific in situ DNA fragmentation staining, (4) prevention by deoxycytidine (IC50 = 1 microM), protein, and RNA synthesis inhibitors, and (5) release of DNA fragments in the incubating medium. We have also observed that several proteins were overexpressed in AraC-treated neurons by two-dimensional polyacrylamide gel electrophoresis. We conclude that AraC induces a signal that triggers a cascade of new mRNA and protein synthesis, leading to apoptotic cell death in cultured cerebellar granule cells.
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Pollard H, Tuchin P. Cervical radiculopathy: a case for ancillary therapies? J Manipulative Physiol Ther 1995; 18:244-9. [PMID: 7636415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To present two cases, one of a patient with a radicular syndrome and another of a patient with a pseudoradicular syndrome. CLINICAL FEATURES A 45-yr-old man visited one chiropractic clinic complaining of a "pinched nerve" in his neck, with pain and paresthesia in his left hand. He reported that these symptoms began after a work accident 1 month before, when he lifted a heavy object. Radiographs revealed disk space thinning at C4-5, C5-6 and C6-7. CT scans revealed foraminal narrowing with a minor disk bulging at the level of C5-6 and a large disk protrusion at C7-T1. The second patient is a 60-yr-old man with left shoulder and cervical spine pain. The patient stated that the shoulder pain felt like an ache and had begun 2 wk earlier when he had awakened with pain in the shoulder and a stiff neck. X-ray evaluation revealed a moderate level of degenerative change at the the C4-5, C5-6 and C7-T1 region. CONCLUSION This article identifies the similarities and variations between two syndromes receiving chiropractic intervention that included ancillary therapy. Certain conditions, including cervical radiculopathy, seem to respond well to chiropractic spinal manipulative therapy. However, in other conditions with similar symptomatology, appropriate referral may be necessary for the condition to respond. Alternatively, adjunctive or ancillary therapy may be indicated to improve the effect of the chiropractic intervention.
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Marianowski R, Pollard H, Moreau J, Després G, Ben Ari Y, Tran Ba Huy P, Romand R. N-Methyl-D-aspartate receptor subunits NR1 and NR2C are overexpressed in the inferior colliculus of audiogenic mice. Neurosci Lett 1995; 189:190-4. [PMID: 7624042 DOI: 10.1016/0304-3940(95)11454-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Some non-DBA2 Albino Swiss mice exhibit noise induced epileptic seizures during a short period of postnatal development. Because N-methyl-D-aspartate (NMDA) glutamate ionotropic receptors are involved in the occurrence of audiogenic seizures, we investigated by in situ hybridization methods, the expression of the different subunits (NR1, NR2A, NR2B, NR2C) of this receptor in the central nucleus of the inferior colliculus (IC), a main relay of the auditory pathways. At postnatal day 20, the NR2C subunit is highly expressed in the IC of convulsive mice, while in non-convulsive mice a slight signal is only found for NR1, NR2A, and NR2B. In adult mice, the NR1 and NR2A signals are observed while the NR2B signal is almost undetectable. The audiogenic susceptibility may be related to the transient expression of the NR2C subunit during a brief neonatal period during which synaptic reorganization happens.
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Khrestchatisky M, Ferhat L, Charton G, Bernard A, Pollard H, Represa A, Ben-Ari Y. Molecular correlates between reactive and developmental plasticity in the rat hippocampus. JOURNAL OF NEUROBIOLOGY 1995; 26:426-36. [PMID: 7775975 DOI: 10.1002/neu.480260314] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Area CA3 of the hippocampus is the most epileptogenic structure of the brain. Various studies have shown that kainate-induced experimental epilepsy in rats and human cases of epilepsy are associated with sprouting of the mossy fibers of the dentate granule neurons and selective loss of pyramidal neurons, notably in the CA3-CA4 areas of Ammon's horn. In experimental models of epilepsy, brief seizure activity initiates a cascade of molecular alterations that will contribute to changes in the expression of numerous genes, which can last several weeks. The products of some of these genes will contribute to the permanent state of enhanced synaptic efficiency, to the sprouting and formation of novel excitatory synapses, and possibly to neuronal cell loss. The expression of genes encoding transcription factors and numerous growth factors is rapidly altered following seizure episodes. Based on observations in vivo and in vitro in cultured hippocampal neurons, it is hypothesized that an interplay between transcription and growth factors, because of their pleiotropic effects on the regulation of effector genes, may be instrumental in coupling transient extracellular stimuli to irreversible cellular alterations.
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Represa A, Niquet J, Pollard H, Ben-Ari Y. Cell death, gliosis, and synaptic remodeling in the hippocampus of epileptic rats. JOURNAL OF NEUROBIOLOGY 1995; 26:413-25. [PMID: 7775974 DOI: 10.1002/neu.480260313] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Seizures set in motion complex molecular and morphological changes in vulnerable structures, such as the hippocampal complex. A number of these changes are responsible for neuronal death of CA3 and hilar cells, which involves necrotic and apoptotic mechanisms. In surviving dentate granule cells seizures induce an increased expression of tubulin subunits and microtubule-associated proteins, suggesting that an overproduction of tubulin polymers would lead to a remodeling of mossy fibers (the axons of granule cells). In fact, these fibers sprout in the dentate gyrus to innervate granule cell dendrites, creating recurrent excitatory circuits. In contrast, terminal mossy fibers do not sprout in the CA3 field. Navigation of mossy fiber's growth cones may be facilitated by astrocytes, which would exert differential effects by producing and excreting cell adhesion and substrate molecules. In the light of the results discussed here, we suggest that in adult brain activated-resident astrocytes (nonproliferating, tenascin-negative, neuronal cell-adhesion molecule-positive astrocytes) could contribute to the process of axonal outgrowth and synaptogenesis in the dentate gyrus, while proliferating astrocytes, tenascin-positive, could impede any axonal rearrangement in CA3.
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Pollard H, Guilhem D, Moreau J, Suzuki F, Onténiente B. Decreased pentylenetetrazol-induced expression of zif/268 in NGF-transgenic mice. Neuroreport 1994; 5:2246-8. [PMID: 7881037 DOI: 10.1097/00001756-199411000-00010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Expression of the proto-oncogene zif/268 was investigated by in situ hybridization in the hippocampus and cerebral cortex of nerve growth factor (NGF)-transgenic mice during pentylenetetrazol (PTZ)-induced seizures. NGF-transgenic mice displayed normal basal levels of zif/268 mRNA in cortex and hippocampal formation except for the dentate gyrus which contained significantly reduced levels. PTZ induced a similar transient increase of zif/268 mRNA in cortex and Ammon's horn of normal and NGF-transgenic mice. On the other hand, increase of zif/268 mRNA in the dentate gyrus was significantly lower in transgenic mice. Reduced PTZ-induced activation of zif268 may reflect a decreased sensitivity of NGF-transgenic animals to epilepsy by direct or indirect interaction of NGF with immediate early genes.
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Pollard H, Charriaut-Marlangue C, Cantagrel S, Represa A, Robain O, Moreau J, Ben-Ari Y. Kainate-induced apoptotic cell death in hippocampal neurons. Neuroscience 1994; 63:7-18. [PMID: 7898662 DOI: 10.1016/0306-4522(94)90003-5] [Citation(s) in RCA: 322] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have examined the role apoptosis plays in epileptic brain damage using intra-amygdaloid injection of kainate. With the silver staining technique of Gallyas, argyrophylic (dying) neurons were observed, a few hours after the injection, in the amygdala and in the vulnerable pyramidal neurons of the hippocampal CA3 region. In both areas, cell death has apoptotic features, including: (i) nuclear chromatin condensation and marginalization with light and electron microscopy; (ii) DNA fragmentation with a typical ladder pattern on agarose gel electrophoresis; (iii) positive nuclear labelling with a selective in situ DNA fragmentation staining method. Combined in situ DNA labelling and silver staining showed that the DNA fragmentation occurred in dying neurons. CA1 or granule cells which do not degenerate following intra-amygdaloid injection of kainate were not stained with the in situ DNA labelling or the argyrophylic technique. Administration of diazepam blocked the kainate-induced seizures and prevented DNA fragmentation in CA3 but not in the amygdala. Therefore, apoptosis contributes to the local and distant damage induced by kainate.
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Tardif JC, Cao QL, Pandian NG, Esakof DD, Pollard H. Determination of cardiac output using acoustic quantification in critically ill patients. Am J Cardiol 1994; 74:810-3. [PMID: 7942556 DOI: 10.1016/0002-9149(94)90441-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The reliability of automated acoustic quantification (AQ) in yielding real-time left ventricular (LV) area, volume, and ejection fraction has been validated. The purpose of this study was to explore the potential of AQ in providing accurate immediate determination of cardiac output in critically ill patients. A total of 48 patients were studied. One group consisted of 37 critically ill patients with indwelling Swan-Ganz catheters. In these patients, cardiac output by AQ, manual tracing of end-diastolic and end-systolic frames of 2-dimensional images, and thermodilution were measured. AQ was also compared with Doppler calculation of flow through the left and right ventricles in 11 additional patients. Adequate data for calculation of cardiac output with AQ were obtained in 78% of critically ill patients. There was an excellent correlation between AQ and off-line manual analysis for LV volumes (r = 0.94 and 0.91 for end-diastole and end-systole), ejection fraction (r = 0.85), and cardiac output (r = 0.93). AQ also correlated well with Doppler analysis (r = 0.97) and thermodilution technique (r = 0.95) in the determination of cardiac output. However, AQ slightly underestimated thermodilution measurements, with rather wide limits of agreement (-0.3 +/- 1.1 liter/min). There was a similar underestimation of cardiac output with manual analysis when compared with thermodilution. Given the absence of significant differences between AQ and manual analysis, this observation suggests that the bias is related to the echocardiographic determination of stroke volume, and not to errors from the automated border detection. It is concluded that AQ, besides providing information on LV volumes and ejection fraction, also can yield rapid measurements of cardiac output in most patients who are acutely ill.
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Gelot A, Moreau J, Khrestchatisky M, Ben Ari Y, Pollard H. Developmental change of alpha-spectrin mRNA in the rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1994; 81:240-6. [PMID: 7813045 DOI: 10.1016/0165-3806(94)90310-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Spectrin is a cytoskeletal protein considered to be a major component of intracellular cohesion. Using an in situ hybridization approach, we have investigated the developmental expression of the mRNA encoding the alpha-subunit of rat brain spectrins, from birth to adulthood. alpha-Subunit mRNA is detectable at birth, in brain areas with perinatal neurogenesis, such as the cerebral cortex, hippocampus, thalamus, and olfactory bulb. alpha-Brain-spectrin mRNA increases gradually during the first postnatal days to reach a plateau between the second and the third week of life. In the young adult brain, the level of alpha-brain spectrin mRNA decreased globally. This spacio-temporal distribution argues for the involvement of the mRNA in the synthesis of both the erythroid and non-erythroid brain spectrin isoforms. We have focused our attention on the hippocampal formation and the cerebellum. In both regions, in situ hybridization signal variations are superimposable with neuronal maturation gradients. This pattern of variation, coupled with the known interaction of brain spectrins with other cytoskeletal proteins, agrees with the notion that brain spectrins may be involved in neuronal differentiation by way of the cytoskeletal lattice organization.
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Pollard H, Khrestchatisky M, Moreau J, Ben-Ari Y, Represa A. Correlation between reactive sprouting and microtubule protein expression in epileptic hippocampus. Neuroscience 1994; 61:773-87. [PMID: 7838377 DOI: 10.1016/0306-4522(94)90401-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Temporal lobe epilepsy in both human and rats is associated with a collateral sprouting of hippocampal mossy fibers (i.e. the axons of granule cells). This sprouting generates abnormal recurrent synaptic connections. We previously showed that in the experimental model of temporal lobe epilepsy induced by an intra-amygdaloid injection of kainate, the synaptic remodeling of mossy fibers was preceded by a transient increased expression of alpha-tubulin in granule cells. This suggests that an overproduction of tubulin polymers may be responsible, at least in part, for the elongation and side-branching of mossy fibers, which occurs 12-30 days after seizures. In the present study we show that this increased expression of alpha-tubulin is accompanied by an increased expression of the microtubule-associated proteins MAP2 and TAU. Thus, using in situ hybridization, we observe that MAP2 messenger RNA levels increased in granule cell bodies and dendrites from day 3 to two weeks after kainate treatment. This rise is associated with a concomitant transient increase of MAP2 immunoreactivity in the granule cell dendrites. TAU messenger RNA also increases in granule cell bodies, while TAU immunoreactivity increases in their axons, the mossy fibers. The time course of these changes parallels that of alpha-tubulin, and develops before and during the axonal mossy fiber sprouting. Since MAP2 and TAU are important for the initiation, elongation and stabilization of neurites, we suggest that the overexpression of these proteins via the formation of microtubules may play an important role in the sprouting of mossy fibers in epileptic rats.
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Chinestra P, Leinekugel X, Ben Ari Y, Pollard H. Use of hippocampal slices to study mRNA changes in relation to synaptic plasticity. Neuroreport 1994; 5:1461-5. [PMID: 7948839 DOI: 10.1097/00001756-199407000-00013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have developed a method allowing suitable morphological conservation combined with in situ hybridization, on hippocampal slices used in conventional electrophysiological studies. After a bath application of kainate (KA, 750 nM, 2 min 15 s), electrical stimulation of the mossy fibre zone evoked epileptiform activity for up to 2 h. In situ hybridization performed on these slices showed a marked increased in expression of the transcription factor Zif/268 over the pyramidal and the granule cells and the surrounding neuropils. Bath application of tetraethylammonium (TEA, 25 mM, 10 min) elicited long-term potentiation in CA1 lasting up to 4 h. This was associated with enhanced expression of Zif/268 which returned to control values after 2 h 30 min. These observations suggest that slice preparations are suitable for the study of the role of neuronal activity in the regulation of gene expression.
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Represa A, Niquet J, Pollard H, Khrestchatisky M, Ben-Ari Y. From seizures to neo-synaptogenesis: intrinsic and extrinsic determinants of mossy fiber sprouting in the adult hippocampus. Hippocampus 1994; 4:270-4. [PMID: 7842049 DOI: 10.1002/hipo.450040308] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Pollard H, Cantagrel S, Charriaut-Marlangue C, Moreau J, Ben Ari Y. Apoptosis associated DNA fragmentation in epileptic brain damage. Neuroreport 1994; 5:1053-5. [PMID: 8080958 DOI: 10.1097/00001756-199405000-00009] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have examined the epileptic brain damage generated by intra-amygdaloid administration of kainic acid (KA). In the vulnerable CA3 region of the rat hippocampus, neurones developed apoptotic properties since, (i) their nuclei were positively stained with a selective in situ DNA fragmentation staining method; (ii) DNA cleavage into internucleosome-sized fragments was observed on agarose gels. Our results suggest that epileptic seizures generated in the amygdala by KA trigger apoptotic cell damage in pyramidal CA3 neurones.
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Skryzdło-Radomańska B, Pollard H, Schabowski J, Radwan P, Celiński K, Pokora J, Gespach C. [Activity of enkephalinase (EC.3.4.24.11). Neutral endopeptidase (NEP)in human digestive tract epithelial cells]. WIADOMOSCI LEKARSKIE (WARSAW, POLAND : 1960) 1994; 47:13-17. [PMID: 8030341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The activity was studied of enkephalinase (endopeptidase 24.11, neutral endopeptidase)--a membrane enzyme of epithelial cells within human digestive tract (in the stomach, duodenum, small intestine, ascending, descending and sigmoid colon, and rectum). The enzyme activity was determined by column method using the labelled substrate (H-D-AlaLeu)--enkephalin and the selective enkephalin inhibitor--thiorfan in the presence of bestatin and captopril--inhibitors of aminopeptidases and angiotensin converting enzyme respectively. The highest enkephalinase activity was found in the duodenal epithelium (77.3 8.0 fmol of the substrate/min/mg of protein) and in the small intestine (23.4 0.9 fmol/min/mg of protein) with its gradual decrease when progressing down the gastrointestinal tract. This result confirms the hypothesis of enkephalinase participation in protein hydrolysis processes.
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