bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential NF‐κB regulation of bcl‐x gene expression in hippocampus and basal forebrain in response to hypoxia
Authors: Qiu Jingxin , Grafe Marjorie R. , Schmura Shannon M. , Glasgow Joel N. , Kent Thomas A. , Rassin David K. , Perez‐Polo J. Regino
Published: October 2004

Cell death often occurs after hypoxic/ischemic injury to the central nervous system. Changes in levels of the anti‐apoptotic Bcl‐XL protein may be a determining factor in hypoxia‐induced neuronal apoptosis. The transcription factor NF‐κB regulates bcl‐x gene expression. In this study, we examined the role of NF‐κB in the regulation of bcl‐x in hypoxia‐induced cell death. Rat hippocampus and basal forebrain tissues were collected at different time points after hypoxia (7%O2, 93% N2 for 10 or 20 min). We found that 1) hypoxia induced apoptosis in the hippocampus and basal forebrain; 2) the NF‐κB dimers c‐Rel/p50 and p50/p50 bound to the bcl‐x promoter NF‐κB sequence (CS4) in the hippocampus, but only p50/p50 bound to the CS4 sequence in the basal forebrain and hypoxia‐induced differential binding patterns of c‐Rel/p50 and p50/p50 correlated with the bcl‐x expression pattern in the hippocampus; 3) the hypoxia‐induced patterns of binding of c‐Rel/p50 to the bcl‐x promoter CS4 sequence were different from those to the IgG‐κB enhancer sequence, whereas those of p50/p50 were similar to both sequences; 4) nuclear protein levels of c‐Rel, but not p50, correlated with the c‐Rel/p50 DNA binding patterns to the bcl‐x CS4 site; and 5) there were differential responses to hypoxia among the different NF‐κB protein subunits. These results suggest that there is a tissue‐specific regulation of bcl‐x gene expression by NF‐κB in hypoxia‐induced cell death in the hippocampus. The absence of these regulating features in the basal forebrain may account for the early appearance of apoptosis in response to hypoxia as compared with that in hippocampus. J. Neurosci. Res. 64:223–234, 2001. © 2001 Wiley‐Liss, Inc.
Serotonin regulation of nerve growth factor synthesis in neonatal and adult astrocytes: Comparison to the β‐adrenergic agonist isoproterenol
Authors: Krzan Mojca , Wu Vivian W. , Schwartz Joan P.
Published: October 2004

Although serotonin regulates synthesis of the neurotrophic factor S‐100β by astrocytes, its ability to affect nerve growth factor (NGF) synthesis has never been examined. We report here that there is a correlation between the effect of serotonin on cyclic adenosine monophosphate (cAMP) content and on NGF content in neonatal astrocytes but not in adult astrocytes. In neonatal striatal astrocytes, serotonin increases both cAMP and NGF, whereas, in neonatal cerebellar astrocytes, serotonin decreases both. The increase in neonatal cortical astrocyte cAMP appeared to be too small (45%) to increase NGF significantly. The β‐adrenergic agonist isoproterenol increased cAMP and NGF in both cortical and striatal astrocytes derived from neonatal rats. In contrast, there was a dissociation between cAMP changes and NGF changes in astrocytes derived from adult rats. Both serotonin and isoproterenol increased cAMP in adult cortical astrocytes, without any effect on NGF content. However, adult striatal astrocytes responded to serotonin with an elevation of both cAMP and NGF, whereas isoproterenol could only enhance cAMP, without affecting NGF. Thus, in neonatal astrocytes, a change of sufficient magnitude in cAMP was correlated with a comparable change in NGF, in response to activation of either serotonergic or β‐adrenergic receptors; in cerebellar astrocytes, the decrease in cAMP was accompanied by a decrease in NGF. In contrast, adult astrocytes were not responsive: Although cAMP changes were large, NGF synthesis was increased only in striatal astrocytes and only in response to serotonin. J. Neurosci. Res. 64:261–267, 2001. Published 2001 Wiley‐Liss, Inc.
Vaccination with a CDR2 BV6S2/6S5 peptide in adjuvant induces peptide‐specific T‐cell responses in patients with multiple sclerosis
Authors: Morgan Elizabeth E. , Nardo Christopher J. , Diveley Jocelyn P. , Kunin Joel , Bartholomew Richard M. , Moss Ronald B. , Carlo Dennis J.
Published: October 2004

Earlier studies from several groups including ours have documented that patients with multiple sclerosis (MS) have over‐expression of activated T‐cells from specific TCR Vβ families, including BV6S2/S5 (Kotzin et al. [1991] Proc. Natl. Acad. Sci. USA 88:9161–9165; Gold et al. [1997] J. Neuroimmunol. 76:29–38). It has also been established in the rat EAE model that peptide vaccines to the over‐expressed Vβ 8.2 TCR can prevent MBP induced disease (Vandenbark et al. [1989] Nature 341:541–544). In the current clinical study, 10 patients were vaccinated with 300 μg of BV6S2/6S5 peptide emulsified in incomplete Freund's adjuvant (IFA) and monitored for safety and immunogenicity in a 48‐week multicenter, open‐label trial. The peptide vaccine was well tolerated and no serious adverse events were observed. Vaccinations induced cell‐mediated immunity to the immunizing peptide in eight of 10 patients as demonstrated by lymphocyte proliferation assay (LPA) and delayed‐type hypersensitivity (DTH) skin test responses. In summary, these results demonstrate that immunization with TCR BV6S2/6S5 peptide vaccine in MS patients is safe and immunogenic, and supports a larger double‐blind placebo controlled trial to determine the clinical efficacy of this approach. J. Neurosci. Res. 64:298–301, 2001. © 2001 Wiley‐Liss, Inc.
Neuronal and glial β‐secretase (BACE) protein expression in transgenic Tg2576 mice with amyloid plaque pathology
Authors: Roßner Steffen , Apelt Jenny , Schliebs Reinhard , Perez‐Polo J. Regino , Bigl Volker
Published: October 2004

We measured tissue distribution and expression pattern of the beta‐site amyloid precursor protein (APP)‐cleaving enzyme (BACE) in the brains of transgenic Tg2576 mice that show amyloid pathology. BACE protein was expressed at high levels in brain; at lower levels in heart and liver; and at very low levels in pancreas, kidney, and thymus and was almost absent in spleen and lung when assayed by Western blot analysis. We observed strictly neuronal expression of BACE protein in the brains of nontransgenic control mice, with the most robust immunocytochemical labeling present in the cerebral cortex, hippocampal formation, thalamus, and cholinergic basal forebrain nuclei. BACE protein levels did not differ significantly between control and transgenic mice or as a result of aging. However, in the aged, 17‐month‐old Tg2576 mice there was robust amyloid plaque formation, and BACE protein was also present in reactive astrocytes present near amyloid plaques, as shown by double immunofluorescent labeling and confocal laser scanning microscopy. The lack of astrocytic BACE immunoreactivity in young transgenic Tg2576 mice suggests that it is not the APP overexpression but rather the amyloid plaque formation that stimulates astrocytic BACE expression in Tg2576 mice. Our data also suggest that the neuronal overexpression of APP does not induce the overexpression of its metabolizing enzyme in neurons. Alternatively, the age‐dependent accumulation of amyloid plaques in the Tg2576 mice does not require increased neuronal expression of BACE. Our data support the hypothesis that neurons are the primary source of β‐amyloid peptides in brain and that astrocytic β‐amyloid generation may contribute to amyloid plaque formation at later stages or under conditions when astrocytes are activated. J. Neurosci. Res. 64:437–446, 2001. © 2001 Wiley‐Liss, Inc.
mDll1 and mDll3 expression in the developing mouse brain: Role in the establishment of the early cortex
Authors: Campos Lia Scotti , Duarte António José , Branco Tiago , Henrique Domingos
Published: October 2004

The Delta/Notch signalling system is involved in several developmental processes. During fly neurogenesis, Delta expression defines the fate of neuronal precursors and inhibits neighboring Notch‐expressing cells from acquiring a neural fate, a process known as lateral inhibition. In vertebrates, recent evidence demonstrates that Notch activation can positively determine cell fate and affect neuronal process extension. Nevertheless, Delta‐like expression patterns during brain development are relatively unknown. Using a transgenic mouse, which expresses LacZ under the mDll1 promoter, we show by immunofluorescence that in the developing telencephalon mDll1 is expressed in undifferentiated cells in close contact with radial glial cells. Based on in situ hybridization data on mDll1 and mDll3 mRNA expression and on the immunohistochemical detection of β‐galactosidase in the Dll1‐lacZ transgenic mouse, we suggest that mDll1 and mDll3 are involved in the establishment of the early cortical plate and that mDll1‐expressing cells are in close contact with radial glial cells, thereby modulating the latter population, which is known to express Notch1. Furthermore, we suggest that the decrease in mDll1 mRNA found toward the end of gestation could be related, first, to the slowing of neurogenesis and, second, to the differentiation of the radial glial cell population into astrocytes. J. Neurosci. Res. 64:590–598, 2001. © 2001 Wiley‐Liss, Inc.
GABAA receptor gene expression in rat cortex: Differential effects of two chronic diazepam treatment regimes
Authors: Arnot Michelle I. , Davies Martin , Martin Ian L. , Bateson Alan N.
Published: October 2004

Diazepam is widely prescribed as an anxiolytic but its therapeutic application is limited because with daily use tolerance develops to certain aspects of its pharmacological profile. We compared the effects of two dosing paradigms on GABAA receptor gene expression and benzodiazepine binding characteristics. Equivalent daily doses of 15 mg/kg/day diazepam were delivered either via constant infusion or daily subcutaneous injection for 14 days. The two distinct treatment regimes produced significantly different changes in GABAA receptor α4‐, β2‐, β3‐ and γ1‐subunit mRNA steady‐state levels. Similar changes in the GABA enhancement of flunitrazepam binding and the BZ3/BZ2 subtype ratio determined ex vivo were produced, however, significant differences were found in [3H]‐Ro 15‐4513 binding between cortical tissue from diazepam injected animals compared with diazepam infused animals. Our data suggest that it is the diurnal fluctuations in receptor occupancy that are responsible for the different effects produced by these two dosing regimes. J. Neurosci. Res. 64:617–625, 2001. © 2001 Wiley‐Liss, Inc.
CREM and ICER are differentially implicated in trans‐synaptic induction of tyrosine hydroxylase gene expression in adrenal medulla and sympathetic ganglia of rat
Authors: Trocmé C. , Ravassard P. , Sassone‐Corsi P. , Mallet J. , Faucon Biguet N.
Published: October 2004

Reserpine treatment leads to a trans‐synaptic increase of the tyrosine hydroxylase (TH) gene transcription rate, mRNA and protein levels in catecholaminergic tissues including the adrenal medulla (AM) and the superior cervical ganglia (SCG). The TPA‐responsive element plays an important role in the trans‐synaptically‐induced transcription of the TH gene in the AM, whereas it does not appear to be involved in the SCG (Trocmé et al. [1997] J. Neurosci. Res. 48:489–498). In this study, we show that another regulatory sequence of the TH proximal promoter, the cAMP‐responsive element (CRE), binds different factors in the AM and in the SCG. To elucidate the dynamics of promoter regulation a complete time course analysis was conducted. Reserpine treatment enhances, between 1 hr and 8 hr after the injection, the expression and the binding of the repressor ICER in the AM, whereas in the SCG it enhances the binding of CREM factors. These results suggest that the mechanisms mediating trans‐synaptic induction of the TH gene are different in the AM and SCG. The interplay between positive and negative transcription factors and their kinetics of action are responsive of the long‐term regulation of the TH gene. J. Neurosci. Res. 65:91–99, 2001. © 2001 Wiley‐Liss, Inc.
Neural recognition molecule NB‐2 of the contactin/F3 subgroup in rat: Specificity in neurite outgrowth‐promoting activity and restricted expression in the brain regions
Authors: Ogawa Junko , Lee Suni , Itoh Kouichi , Nagata Saburo , Machida Takeo , Takeda Yasuo , Watanabe Kazutada
Published: October 2004

NB‐2, a neural cell recognition molecule of the contactin/F3 subgroup, promoted neurite outgrowth of the cerebral cortical neurons but not the hippocampal neurons. NB‐2 in rat became apparent after birth at protein level, reaching a maximum at postnatal day 14 in the cerebrum and postnatal day 3 in the cerebellum. NB‐2 in the cerebellum declined abruptly thereafter. In situ hybridization demonstrated that NB‐2 mRNA was highly expressed in regions implicated in the central auditory pathway, including the cochlear nuclei, superior olive, inferior colliculi, medial geniculate nuclei, and auditory cortex. In addition, a high level of NB‐2 expression was observed in the accessory olfactory bulb, thalamic nuclei, facial nucleus, and inferior olive. By immunohistochemistry, intense immunoreactivity against NB‐2 was also detected in the auditory pathway. Thus, NB‐2 is expressed in highly restricted brain regions, including the auditory system, suggesting that it plays specific roles in the development and/or maturation of the regions. J. Neurosci. Res. 65:100–110, 2001. © 2001 Wiley‐Liss, Inc.
Target‐dependent modulation of neurotransmitter release in cultured Helix neurons involves adhesion molecules
Authors: Ghirardi Mirella , Naretto Giuseppe , Fiumara Ferdinando , Vitiello Francesco , Montarolo Pier Giorgio
Published: October 2004

The secretory capabilities of the serotonergic neuron C1 of cerebral ganglion of Helix pomatia were markedly reduced when it was cultured in contact with the wrong target neuron, C3. When the neuron B2, one of its physiological targets, was micromanipulated within the network made of intermingled neurites originating from the axonal stumps of both C1 and C3 neurons, C1 increased the amount of the evoked transmitter release, which, after 30 min, reached the level observed when cocultured with the appropriate target. The removal of the appropriate target brought C1 back to the low release condition. By imaging C1 neurites with a fluorescent dye, morphological changes involving a local increase in the number of varicosities could be observed as early as 30 min after contact with the appropriate target. Monoclonal antibody 4E8 against apCAM, a family of Aplysia adhesion molecules, recognizes apCAM‐like molecules of the Helix central nervous system on immunocytochemistry and Western blot analysis. The contact with the appropriate target previously incubated in a 4E8 solution, which did not interfere with its capacity to respond to serotonin, failed to increase the transmitter release of C1 cocultured in the presence of the wrong target, C3. These results suggest that the apCAM‐like antigens bound to the target membrane participate in the molecular processes responsible for the assembly of the “release machinery” present in the functional presynaptic structure. J. Neurosci. Res. 65:111–120, 2001. © 2001 Wiley‐Liss, Inc.
Developmental expression of a voltage‐dependent potassium channel (Kv3.1) in auditory neurons without cochlear input
Authors: Feng Jane , Morest D. Kent
Published: October 2004

Kv3.1, a voltage‐dependent potassium channel, has two forms, ‐a and ‐b, which differ in expression during development and at the onset of function in the auditory system. To determine whether cochlear nerve input could affect the expression of these two forms, cultures of the developing cochlear nucleus were explanted in the absence of the cochlear nerve at the beginning of cell migration (Hamburger‐Hamilton stage 28–30), while neuroblasts continued to migrate onto the culture substrate. After 8, 15, and 22 days in vitro (three survival groups), cultures were immunostained with antibodies recognizing either both forms of Kv3.1 or only the ‐b form. Only young and newly migrated nerve cells were sampled. In the three survival groups, all nerve cells expressed Kv3.1, among which only 50% or less expressed the ‐b form. Some of the more differentiated multipolar cells expressed the ‐b form, but most were labeled with the antibody that recognizes both forms. Thus, in the absence of peripheral input, both forms of Kv3.1 appear at stages very early in development, although not all cells necessarily coexpress both forms. These results agree with other observations in the chick embryo in situ. They are consistent with previous work implicating Kv3.1 in cell migration during early development. J. Neurosci. Res. 65:121–128, 2001. © 2001 Wiley‐Liss, Inc.
Agonists calcitonin, corticotropin‐releasing hormone, and vasoactive intestinal peptide, but not prostaglandins or β‐adrenergic agonists, elevate cyclic adenosine monophosphate levels in oligodendroglial cells
Authors: Wiemelt Anthony P. , Lehtinen Maria , McMorris F. Arthur
Published: October 2004

Although 3′,5′‐cyclic AMP (cAMP) is known to regulate oligodendrocyte development in vitro, little is known about the identity of agonists that induce cAMP synthesis in oligodendroglia. To identify such agonists, we used a novel immunohistochemical method of visualizing cAMP within single cells to screen compounds that are known to activate cAMP synthesis in other cellular systems. Calcitonin, corticotropin‐releasing hormone, and vasoactive intestinal peptide elevated cAMP in oligodendroglial cells but not in other cell types present in the cultures (i.e., astrocytes and microglia). In contrast, prostaglandins and the β‐adrenergic agonist isoproterenol, which have previously been reported to induce modest increases in oligodendroglial cell cAMP from biochemical assay of cell homogenates, did not induce a detectable cAMP response in individually identified oligodendroglial cells but instead induced a robust cAMP response in nonoligodendroglial cells. J. Neurosci. Res. 65:165–172, 2001. © 2001 Wiley‐Liss, Inc.
Oligodendroglia in the avian retina: Immunocytochemical demonstration in the adult bird
Authors: Seo Je Hoon , Haam Young Gil , Park Sang Wook , Kim Dong Woon , Jeon Gye Sun , Lee Cheol , Hwang Douk Ho , Kim Yong‐Sik , Cho Sa Sun
Published: October 2004

Immunohistochemical techniques were used in conjunction with an avian‐specific probe for oligodendrocyte (OLG) marker, the antibody for transferrin binding protein (TfBP), to study the characteristics and distribution of OLGs in the retina of chickens and quails. For comparison, other antibodies such as myelin basic protein, Rip, and those for labeling Müller cells and microglia were used. A large population of OLGs was found to be distributed throughout the retina, with the distinct pattern of a central‐to‐peripheral gradient. It was possible to detect a spectrum of OLG morphology that bore a resemblance to the subtype of the mammalian central nervous system. In addition to these mature OLGs, limited numbers of TfBP‐positive (TfBP+) cells with the morphology of immature OLGs were found in the immediate vicinity of the optic head. The majority of OLGs appeared in the ganglion cell layer throughout the retina, whereas OLGs in the nerve fiber layer were seen mainly in the central zone of the retina, near the optic nerve head. Double‐labeling experiments showed that OLGs were associated with myelin only in the central region, where the majority of retinal OLGs occurred, but not toward the periphery of the retina. The present study is the first comprehensive analysis of the morphological features and spatial distribution of OLGs in the adult avian retina and provides in vivo evidence for the existence of a substantial population of both mature and immature OLGs in the retina of adult birds. The putative functions of TfBP+ OLGs including myelination and the tropic role of the ganglion cells are discussed in conjunction with the physical properties of TfBP and structural characteristics of the avascular retina of birds. J. Neurosci. Res. 65:173–183, 2001. © 2001 Wiley‐Liss, Inc.
Classic and soma‐restricted proteolipids are targeted to different subcellular compartments in oligodendrocytes
Authors: Bongarzone Ernesto R. , Jacobs Erin , Schonmann Vilma , Campagnoni Anthony T.
Published: October 2004

The myelin proteolipid (PLP) gene is very active in oligodendrocytes (OLs) and generates at least four proteins: the classic PLP and DM20 proteolipids, which are associated with compact myelin and the srPLP and srDM20, which are associated with the cell soma. These proteins are extremely hydrophobic and appear to follow the biosynthetic route used by secretory proteins. In this study, we have analyzed the subcellular distribution of the newly described sr‐proteolipids and compared it to that of the classic proteolipids. Immunocytochemical analysis indicates that the sr‐proteolipids and classic proteolipids are found in association with the endoplasmic reticulum (ER) and Golgi apparatus of mature OLs in vitro. Whereas the classic proteolipids become associated with the myelin‐like sheets elaborated by OLs, the sr‐proteolipids are not targeted to the myelin leaflets. The sr‐proteolipids were associated with endosomes and with recycling vesicles as determined by double immunocytochemistry with markers such as syntaxin 6 and clathrin. In vivo, immunohistochemical analysis showed a distribution of the sr‐proteolipids that was similar to that obtained in vitro, with a total absence of incorporation of sr‐proteolipids into compact myelin. This differential subcellular localization is further evidence for a biological role for these products of the PLP/DM20 gene, which is different from that of the classic proteolipids. J. Neurosci. Res. 65:477–484, 2001. © 2001 Wiley‐Liss, Inc.
Disulfide‐mediated dimerization of L1 Ig domains
Authors: Haspel Jeffrey , Schürmann Gregor , Jacob Jeffrey , Erickson Harold P. , Grumet Martin
Published: October 2004

The neural cell adhesion molecule L1 contains immunoglobulin‐like (Ig) domains in its extracellular region that mediate homophilic binding, neurite outgrowth and other activities relevant to CNS development. To correlate conformations of these domains to biological function, several L1‐Fc fusion proteins whose bioactivities were previously characterized were analyzed by rotary shadowing electron microscopy. We found that bioactive L1‐Fcs containing Ig domains 1–4 or 1–6 exhibited extended, branched structures. In contrast, inactive L1‐Fcs containing only the first two or three Ig domains assumed compact shapes that suggested interactions between the L1 arms of these proteins. Analysis of an untagged L1 fragment composed of Ig domains 1‐3 demonstrated a mixture of monomeric and dimeric forms. Surprisingly, these dimers were stabilized by intermolecular disulfide bonds. Finally, cell surface L1‐GFP fusion proteins containing only the first two or three Ig domains in the extracellular region also engaged in disulfide‐mediated dimerization. These results suggest a novel mechanism by which mutations in L1 could interfere with its biological functioning. J. Neurosci. Res. 66:347–355, 2001. © 2001 Wiley‐Liss, Inc.
Inhibition of nuclear factor‐κB activation induces apoptosis in cerebellar granule cells
Authors: Piccioli Patrizia , Porcile Carola , Stanzione Sabrina , Bisaglia Michela , Bajetto Adriana , Bonavia Rudy , Florio Tullio , Schettini Gennaro
Published: October 2004

The nuclear factor (NF)‐κB family of transcription factors plays important roles in the regulation of many activities of neuronal cells, such as synaptic transmission, inflammation, neuroprotection, and neurotoxicity. In resting cells, NF‐κB activity is present both in the cytoplasm, as an inducible‐inactive complex, and in the nucleus, as a constitutive form. Regulation of its inducible activity relies on processing of IκB(s), which occurs through the proteasome. Here we show that in cerebellar granule cells (CGC) the induction of apoptosis, by potassium withdrawal (5 mM KCl), decreases the amount of nuclear NF‐κB. To understand whether NF‐κB was required for CGC survival, these cells, maintained under depolarizing conditions (25 mM KCl and serum), were treated with proteasome inhibitors. The results show that these treatments reduce the nuclear amount of NF‐κB and increase p65 cytoplasmic levels, a process partially regulated via IκBα degradation. These events are also associated with an impairment in CGC survival, with changes in nuclear morphology, induction of DNA laddering, and oligonucleosome formation, consistent with apoptosis. According to the K+ deprivation model, PSI‐induced apoptosis is reversed by inhibitors of transcription and translation as well as by specific caspase inhibitors. Together our results show an important role for NF‐κB in maintaining CGC survival. Indeed, under conditions of mild depolarization (K25) necessary for CGC survival, NF‐κB is distributed between cytosol and nucleus, whereas, under apoptotic conditions (K5), it is depleted from the nucleus, such as after proteasome inhibitor treatment. Therefore, NF‐κB nuclear deprivation is involved in the induction of CGC apoptosis. J Neurosci. Res. 66:1064–1073, 2001. © 2001 Wiley‐Liss, Inc.
Kainic acid and seizure‐induced Fos in subtypes of cerebrocortical neurons
Authors: Hiscock Jennifer J. , Mackenzie Lorraine , Medvedev Andrei , Willoughby John O.
Published: October 2004

Kainic acid injected in vivo into adult rats evokes the expression of the immediate early gene c‐fos in the dentate gyrus and associated structures before a seizure occurs and in these and additional regions after a single motor seizure. The aim of this study was to identify cortical cell classes expressing Fos that correlate with these phenomena. Fos expression occurred before a seizure in the middle layers of entorhinal cortex in excitatory neurons and predominantly in calbindin D28‐K‐containing inhibitory neurons. Given the early Fos‐labeling of these cells, we suggest they are associated with the hippocampal EEG events also seen at this stage of the effects of kainic acid. After a motor seizure Fos induction occurred in primary motor, sensory, piriform and entorhinal cortices, mainly in excitatory neurons, but also in a proportion of calcium binding protein‐containing neurons proportionate to the degree of activation of the region as determined by Fos. Nearly 100% of neurons were Fos+ in entorhinal cortex, whereas 80% of excitatory and 50% of calcium binding protein‐containing neurons were Fos+ in piriform cortex with lower proportions in neocortex. Of the calcium binding protein‐containing neocortical neurons, calbindin D28‐K cells exhibited the highest proportion of double labeling with Fos. This pattern of neocortical activation by kainic acid, a glutamate agonist, is only slightly different to that seen after seizures caused by blockade of gamma aminobutyric acid receptors suggesting that seizures caused by different mechanisms utilize similar neo‐cortical circuitry. J Neurosci. Res. 66:1094–1100, 2001. © 2001 Wiley‐Liss, Inc.
Role of rRAB22b, an oligodendrocyte protein, in regulation of transport of vesicles from trans Golgi to endocytic compartments
Authors: Rodriguez‐Gabin A.G. , Cammer M. , Almazan G. , Charron M. , Larocca J.N.
Published: October 2004

Intracellular membrane trafficking plays an essential role in the biogenesis and maintenance of myelin. Members of the Rab protein family are important components of the systems that regulate intracellular vesicle transport. We examine the function of rRab22b, a novel rat Rab protein cloned from an oligodendrocyte cDNA library, by visualizing and identifying in living Hela cells the organelles that contain rRab22b. Our results show that rRab22b is present in the trans Golgi/TGN and endocytic compartments. Trafficking of membranes from trans Golgi to endocytic compartments takes place via small tubulo vesicular organelles containing rRab22b. The formation of vesicles in the trans Golgi also appears to be regulated by rRab22b. Additionally, our results suggest that rRab22b controls the transport of vesicles from the trans Golgi to endocytic compartments that localize in oligodendrocyte processes. That rRab22b is involved in the transport of certain proteins from trans Golgi to myelin is suggested by the evidence that certain proteins being targeted to the plasma membrane are first transported from trans Golgi to endocytic compartments. J Neurosci. Res. 66:1149–1160, 2001. © 2001 Wiley‐Liss, Inc.
Rapid recovery from spinal cord injury after subcutaneously administered polyethylene glycol
Authors: Borgens Richard B. , Bohnert Debra
Published: October 2004

Arguably a seminal event in most trauma and disease is the breakdown of the cell membrane. In most cells, this is first observed as a collapse of the axolemmas barrier properties allowing a derangement of ions to occur, leading to a progressive dissolution of the cell or its process. We have shown that an artificial sealing of mechanically damaged membranes by topical application of hydrophilic polymers such as polyethylene glycol (PEG) immediately restores variable levels of nerve impulse conduction through the lesion. This was documented by a rapid recovery of somatosensory evoked potential (SSEP) conduction, and by recovery of the cutaneous trunchi muscle (CTM) reflex in PEG‐treated animals. The CTM reflex is a sensorimotor behavior dependent on an intact (and identified) white matter tract within the ventrolateral funiculus of the spinal cord, and is thus an excellent index of white matter integrity. We show that PEG can be safely introduced into the bloodstream by several routes of administration. Using a fluorescein decorated PEG, we demonstrate that the polymer specifically targets the hemorrhagic contusion of the adult guinea pig spinal cord when administered through the vasculature, but not intact regions of the spinal cord. A single subcutaneous injection (30% weight by weight in sterile saline) made 6 hr after a standardized spinal cord contusion in adult guinea pigs was sufficient to produce a rapid recovery of SSEP propagation through the lesion in only PEG‐treated animals, accompanied by a statistically significant recovery of the CTM reflex. These data suggest that parenterally administered PEG may be a novel treatment for not only spinal injury, but head injury and stroke as well. J Neurosci. Res. 66:1179–1186, 2001. © 2001 Wiley‐Liss, Inc.
Spinal cord reconstruction using NeuroGel™ implants and functional recovery after chronic injury
Authors: Woerly Stéphane , Doan Van Diep , Evans‐Martin F. , Paramore Christopher G. , Peduzzi Jean D.
Published: October 2004

There is currently a lack of effective ways to achieve functional tissue repair of the chronically injured spinal cord. We investigated the potential of NeuroGel™, a biocompatible polymer hydrogel, to induce a reconstruction of the rat spinal cord after chronic compression‐produced injury. NeuroGel™ was inserted 3 months after a severe injury into the post‐traumatic lesion cavity. Rats were placed in an enriched environment and the functional deficits were measured using the BBB rating scale. A significant improvement in the mean BBB scores was observed. Rats without enriched environment and severely injured rats with an enriched environment alone showed no improvement; however, 7 months after reconstructive surgery using NeuroGel™, a reparative neural tissue had formed within the polymer gel that included myelinated axons and dendro‐dendritic contacts. NeuroGel™ implantation into a chronic spinal cord injury therefore resulted in tissue reconstruction and functional improvement, suggesting that such an approach may have therapeutic value in the repair of focal lesions in humans. J Neurosci. Res. 66:1187–1197, 2001. © 2001 Wiley‐Liss, Inc.
Kinetic evidence for the occurrence of kinetically detectable intermediates in the cleavage of N‐ethoxycarbonylphthalimide under N‐methylhydroxylamine buffers
Authors: Khan M. Niyaz
Published: October 2004

The kinetics of the aqueous cleavage of

N‐ethoxycarbonylphthalimide (NCPH) in CH3NHOH buffers of different pH reveals that the cleavage follows the general irreversible consecutive reaction path NCPH $\buildrel{k_{1\,{\rm obs}}}\over\longrightarrow$ ENMBC $\buildrel{k_{2\,{\rm obs}}}\over\longrightarrow$ A $\buildrel{k_{3\,{\rm obs}}}\over\longrightarrow$ B, where ENMBC, A, and B represent ethyl N‐[o‐(N‐methyl‐N‐hydroxycarbamoyl)benzoyl]carbamate, N‐hydroxyl group cyclized product of ENMBC, and o‐(N‐methyl‐N‐hydroxycarbamoyl)benzoic acid, respectively. The rate constant k1 obs at a constant pH, obeys the relationship k1 obs = kw + knapp [Am]T + kb[Am]T2, where [Am]T is the total concentration of CH3NHOH buffer and kw is first‐order rate constant for pH‐independent hydrolysis of NCPH. Buffer‐dependent rate constant kb shows the presence of both general base and general acid catalysis. Both the rate constants k2 obs and k3 obs are independent of [Am]T (within the [Am]T range of present study) at a constant pH and increase linearly with the increase in aOH with definite intercepts. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 95–103, 2002
Vascular procedures that thermo‐coagulate collagen reduce local platelet deposition and thrombus formation: Laser and laser‐thermal versus balloon angioplasty
Authors: Abela George S. , Hage‐Korban Elie E. , Tomaru Takanobu , Barbeau Gérald R. , Abela Oliver G. , Friedl Stephan E.
Published: October 2004

Background and Objective

Exposure of the arterial wall matrix to blood leads to platelet deposition resulting in thrombosis. Because heat alters tissue matrix we proposed that heating reduces platelet deposition.

Study Design/Materials and Methods

Sixty arterial homografts (15 dogs) were mounted in an arterio‐venous “shunt.” Interventions included balloon angioplasty (BA), direct laser (LA), laser‐thermal (LTA), and combined LTABA. 111Indium‐labeled platelets were circulated, radio activity measured, and homografts processed for histology.

Results

Radioactivity count (mean ± SE) at BA sites (13,853 ± 3,192 cpm/cm2) was greater than LA (7,038 ± 981), LTA (5,294 ± 1,145), LTABA (6,176 ± 1,571), and control (1,826 ± 339), P < 0.05. Electron microscopy showed fewer platelets at LA, LTA, and control than BA sites. BA spread the collagen on the arterial lumen while heat gelled collagen and confined it to the arterial media.

Conclusions

Heating the artery and gelling collagen during LA, LTA, or LTABA significantly reduced thrombogenicity. Lasers Surg. Med. 29:455–463, 2001. © 2001 Wiley‐Liss, Inc.
2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a (HPPH) in a nude rat glioma model: Implications for photodynamic therapy
Authors: Lobel Jeffrey , MacDonald Ian J. , Ciesielski Michael J. , Barone Tara , Potter William R. , Pollina John , Plunkett Robert J. , Fenstermaker Robert A. , Dougherty Thomas J.
Published: October 2004

Background and Objective

In this study, we evaluated 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐α (HPPH or Photochlor) as a photosensitizer for the treatment of malignant gliomas by photodynamic therapy (PDT).

Study Design/Materials and Methods

We performed in vivo reflection spectroscopy in athymic rats to measure the attenuation of light in normal brain tissue. We also studied HPPH pharmacokinetics and PDT effects in nude rats with brain tumors derived from stereotactically implanted U87 human glioma cells. Rats implanted with tumors were sacrificed at designated time points to determine the pharmacokinetics of HPPH in serum, tumor, normal brain, and brain adjacent to tumor (BAT). HPPH concentrations in normal brain, BAT and tumor were determined using fluorescence spectroscopy. Twenty‐four hours after intravenous injection of HPPH, we administered interstitial PDT treatment at a wavelength of 665 nm. Light was given in doses of 3.5, 7.5 or 15 J/cm at the tumor site and at a rate of 50 mW/cm.

Results

In vivo spectroscopy of normal brain tissue showed that the attenuation depth of 665 nm light is ∼30% greater than that of 630 nm light used to activate Photofrin, which is currently being evaluated for PDT as an adjuvant to surgery for malignant gliomas. The t½ of disappearance of drug from serum and tumor was 25 and 30 hours, respectively.

Conclusion

Twenty‐four hours after injection of 0.5 mg/kg HPPH, tumor‐to‐brain drug ratios ranged from 5:1 to 15:1. Enhanced survival was observed in each of the HPPH/PDT‐treated animal groups. These data suggest that HPPH may be a useful adjuvant for the treatment of malignant gliomas. Lasers Surg. Med. 29:397–405, 2001. © 2001 Wiley‐Liss, Inc.
Development of a novel indwelling balloon applicator for optimizing light delivery in photodynamic therapy
Authors: Madsen Steen J. , Sun Chung‐Ho , Tromberg Bruce J. , Hirschberg Henry
Published: October 2004

Background and Objective

A human glioma spheroid model is used to investigate the efficacy of different light delivery schemes in 5‐aminolevulinic acid (ALA)—mediated photodynamic therapy (PDT). The results provide the rationale for the development of an indwelling balloon applicator for optimizing light delivery.

Study Design/Materials and Methods

Human glioma spheroids were incubated in ALA (100 or 1000 μg ml−1) for 4 hours and subjected to various light irradiation schemes. In one set of experiments, spheroid survival was monitored as a function of light fluence rate (5–200 mW cm−2). In all cases, spheroids were exposed to fluences of either 25 or 50 J cm−2. In a second study, the effects of repeated weekly PDT treatments, using sub‐threshold fluences, were investigated. One group of spheroids was subjected to three treatments using fluences of 12, 12, and 25 J cm−2. Results were compared to spheroids receiving single treatments of either 12 or 25 J cm−2. A fluence rate of 25 mW cm−2 was used for all three groups of spheroids. In all cases, the effect of a given irradiation scheme was evaluated by monitoring spheroid growth.

Results

Low fluence rates produce greater cell kill than high fluence rates. The minimum effective fluence rate in human glioma spheroids is approximately 10 mW cm−2. Repeated weekly PDT treatments with sub‐threshold fluences result in significant cell kill. In spheroids surviving the PDT treatments, growth is suppressed for the duration of the treatment period.

Conclusion

The results of the in vitro studies support the development of an indwelling balloon applicator for the delivery of light doses in long term multi‐fractionated PDT regimens. Lasers Surg. Med. 29:406–412, 2001. © 2001 Wiley‐Liss, Inc.
A laser pumped Nd3+‐doped YAG fiber‐optic thermal tip for laser thermotherapy
Authors: Tong Limin , Zhu Dan , Luo Qingming , Hong Defei
Published: October 2004

Background and Objective

Photo‐thermal converters have been successfully used in laser surgery; however, most of the currently used converters are likely to be damaged in the operations due to various problems, preventing them from being efficiently and repeatedly used in laser thermotherapy. Aiming to solve these problems, we report a new type of fiber‐optic photo‐thermal converter with higher stability.

Study Design/Materials and Methods

A laser‐pumped highly Nd3+‐doped Y3Al5O12 (YAG) crystal fiber tip had been fabricated for photo‐thermal conversion by means of phonon relaxation. The 15at.% neodymium‐doped near cylindrical YAG crystal fiber tip, with maximum diameter of 1.1 mm and length of 2.7 mm, was fabricated on a 1 mm‐thick 42 mm‐long pure YAG single crystal fiber by laser heated pedestal growth (LHPG) method.

Results and Conclusion

Pumping by a Ti:Sapphire laser with central wavelength of 805 nm, the tip generated a temperature rise of 15°C in egg white with pumping power of 710 mW, the tip temperature increased approximately linearly with the increased pumping power. The distribution of the temperature in two media had also been measured. Experimental results indicated that the tip was promising for laser thermotherapy applications. Lasers Surg. Med. 30:67–69, 2002. © 2002 Wiley‐Liss, Inc.
Facial resurfacing in patients with Fitzpatrick skin type IV*
Authors: Sriprachya‐anunt Suchai , Marchell Nancy L. , Fitzpatrick Richard E. , Goldman Mitchel P. , Rostan Elizabeth F.
Published: October 2004

Background and Objectives

Though post‐inflammatory hyperpigmentation (PIH) is probably the most common complication of laser resurfacing and appears to correlate directly with the intensity of the patient's natural pigmentation, there is very little data that specifically addresses the risks of dyspigmentation in more darkly pigmented patients (Fitzpatrick skin types IV and above). The objective of this study was to evaluate the long‐term dyspigmentation of patients with skin type IV having radial laser resurfacing.

Study Design/Materials and Methods

A retrospective review of the clinical efficacy, incidence of dyspigmentation and other adverse effects, as well as the pre/post‐operative protocol of 22 patients with Fitzpatrick skin type IV who were a minimum of 1 year post‐operative following facial laser resurfacing.

Results

The average patient achieved greater than 50% improvement, indicating adequate treatment being delivered. PIH occurred in 68% of patients, starting 1 month post‐operative and lasting 3.8 months. There was no correlation to pre‐treatment or type of laser used as far as incidence of PIH. True hypopigmentation was not seen in this group of 22 patients.

Conclusions

PIH is the most common complication of facial resurfacing in patients with skin type IV. It is not preventable by choice of laser or skin care regimen pre‐operative, but appears to respond to appropriate treatment once it has developed. Lasers Surg. Med. 30:86–92, 2002. © 2002 Wiley‐Liss, Inc.
Clinical testing of a photoacoustic probe for port wine stain depth determination
Authors: Viator John A. , Au Gigi , Paltauf Guenther , Jacques Steven L. , Prahl Scott A. , Ren Hongwu , Chen Zhongping , Nelson J. Stuart
Published: October 2004

Background and Objective

Successful laser treatment of port wine stain (PWS) birthmarks requires knowledge of lesion geometry. Laser parameters, such as pulse duration, wavelength, and radiant exposure, and other treatment parameters, such as cryogen spurt duration, need to be optimized according to epidermal melanin content and lesion depth. We designed, constructed, and clinically tested a photoacoustic probe for PWS depth determination.

Study Design/Materials and Methods

Energy from a frequency‐doubled, Nd:YAG laser (λ = 532 nm, τp = 4 nanoseconds) was coupled into two 1,500 μm optical fibers fitted into an acrylic handpiece containing a piezoelectric acoustic detector. Laser light induced photoacoustic waves in tissue phantoms and a patient's PWS. The photoacoustic propagation time was used to calculate the depth of the embedded absorbers and PWS lesion.

Results

Calculated chromophore depths in tissue phantoms were within 10% of the actual depths of the phantoms. PWS depths were calculated as the sum of the epidermal thickness, determined by optical coherence tomography (OCT), and the epidermal‐to‐PWS thickness, determined photoacoustically. PWS depths were all in the range of 310–570 μm. The experimentally determined PWS depths were within 20% of those measured by optical Doppler tomography (ODT).

Conclusions

PWS lesion depth can be determined by a photoacoustic method that utilizes acoustic propagation time. Lasers Surg. Med. 30:141–148, 2002. © 2002 Wiley‐Liss, Inc.
Free‐electron laser and heat‐conducting templates: A study of reducing cutaneous lateral thermal damage†
Authors: Spector Nicole , Reinisch Lou , Spector Jared , Ellis Darrel L.
Published: October 2004

Background and Objectives

We developed novel heat‐conducting templates, and tested whether they could effectively remove damaging heat from the tissue during laser ablation. The reduction of lateral thermal damage during cutaneous incisional laser procedures should decrease the time in wound healing. In addition, we selected various infrared wavelengths to determine whether the template effects would be influenced by the laser penetration depth and the particular chromophore absorbing the laser light.

Study Design/Materials and Methods

This study utilized the Free‐Electron Laser at wavelengths of 3.0, 5.5, 6.45, 7.5, and 7.7 μm to produce 1.0 cm incisions on in vitro lightly pigmented human skin. At each of these wavelengths, copper, aluminum, glass, and Plexiglas heat conducting templates were tested. At wavelength 5.5 μm, the study was duplicated using in vitro darkly pigmented skin. Histological samples were evaluated using computerized morphometric analysis.

Results

The adjunct use of both the copper and aluminum templates provided a decrease in thermal damage at each wavelength. Using the copper template reduced lateral thermal damage an average of 67% with no apparent wavelength dependence. The aluminum template reduced thermal damage an average of 54% with no apparent wavelength dependence. The glass and Plexiglas templates did not reduce the lateral thermal damage. At 5.5 μm, no statistically significant difference in lateral thermal damage was observed between darkly and lightly pigmented tissues.

Conclusions

Heat‐conducting templates are an effective new method to reduce lateral thermal damage from thermal laser incisions. Lasers Surg. Med. 30:117–122, 2002. © 2002 Wiley‐Liss, Inc.
Effects of intense pulsed light on sun‐damaged human skin, routine, and ultrastructural analysis*
Authors: Prieto Victor G. , Sadick Neil S. , Lloreta Josep , Nicholson Judy , Shea Christopher R.
Published: October 2004

Background and Objective

New, non‐ablative methods can be used in skin rejuvenation. Histologic analysis of non‐ablative IPL effects on facial, sun‐damaged skin.

Study Design/Materials and Methods

Five female subjects, wrinkle class I or II and Fitzpatrick skin types I, II, and III. IPL treatment: once monthly, 560‐nm cut‐off filters, spot size 8×35 mm, 28–36 J/cm. Routine histology or electron microscopy on 2‐mm punches, before treatment and then 1 week, 3 months, and 12 months.

Results

Pre‐treatment specimens contained solar elastosis and perifollicular lymphoid infiltrates. Collagen and elastic fibers appeared unaffected by treatment. At 1‐week, Demodex organisms appeared coagulated.

Conclusions

Under these conditions, IPL induces minimal morphologic changes in mildly sun‐damaged skin. Some esthetic improvement may be secondary to clearing of Demodex organisms and reduction of associated lymphocytic infiltrate. Lasers Surg. Med. 30:82–85, 2002. © 2002 Wiley‐Liss, Inc.
Laser ablation of the pulmonary veins by using a fiberoptic balloon catheter: Implications for treatment of paroxysmal atrial fibrillation
Authors: Fried Nathaniel M. , Tsitlik Arkadiy , Rent Kenneth C. , Berger Ronald D. , Lardo Albert C. , Calkins Hugh , Halperin Henry R.
Published: October 2004

Background and Objective

Focal sources of paroxysmal atrial fibrillation may be treatable by electrical isolation of the pulmonary veins from the left atrium. A new fiberoptic balloon catheter was tested as an alternative to radiofrequency catheter ablation for creation of circumferential thermal lesions at the pulmonary vein orifice.

Study Design/Materials and Methods

In vitro and in vivo experiments were conducted in canine hearts to demonstrate efficacy and optimize ablation dosimetry. Continuous‐wave, 1.06‐μm, Nd:YAG laser radiation was delivered radially through diffusing optical fiber tips enclosed in a balloon catheter. During in vivo studies, the catheter was placed at the pulmonary vein orifice through a left atrial appendage sheath under X‐ray fluoroscopic guidance during an open‐chest procedure. Additionally, circumferential lesions in the left atrial appendage were correlated with epicardial electrograms demonstrating elimination of electrical activity.

Results

The pulmonary veins were successfully ablated by using laser powers of 30–50 W and irradiation times of 60–90 seconds. Transmural, continuous, and circumferential lesions were produced in the pulmonary veins in a single application without evidence of tissue vaporization or endothelial disruption.

Conclusion

Laser ablation by using a fiberoptic balloon catheter may represent a promising alternative to radiofrequency catheter ablation for electrical isolation of the pulmonary veins from the left atrium during treatment of paroxysmal atrial fibrillation. Further development and testing of the fiberoptic catheter is warranted for possible clinical studies. Lasers Surg. Med. 28:197–203, 2001. © 2001 Wiley‐Liss, Inc.