bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adrenocorticosteroid receptor blockade and excitotoxic challenge regulate adrenocorticosteroid receptor mRNA levels in hippocampus
Authors: McCullers Deanna L. , Herman James P. 
Published: October 2004

AbstractThe mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) are glucocorticoid‐activated transcription factors essential for maintenance of cellular homeostasis. Differential activation of these adrenocorticosteroid receptors (ACR) is thought to influence neuronal viability, particularly under challenging cellular conditions. The present study is designed to determine the effects of receptor blockade and excitotoxic insult on MR and GR mRNA expression and neuronal viability in hippocampus. Male Sprague–Dawley rats were pretreated for 48 hr with vehicle, MR antagonist spironolactone (SPIRO) (50 mg/kg, twice daily, s.c.), or GR antagonist RU486 (25 mg/kg, twice daily, s.c.) and subsequently injected with saline or the glutamate analog kainic acid (KA) (12 mg/kg i.p.). Twenty‐four hr post‐insult, MR and GR mRNA levels were assessed by in situ hybridization analysis, and hippocampal neurons were counted to assess KA‐induced cell loss. MR blockade with SPIRO increased basal MR mRNA levels in hippocampal subregions CA1, CA3, and dentate gyrus (DG) and increased basal GR mRNA levels in CA3. GR blockade with RU486 increased basal GR mRNA levels in CA3. The excitotoxin KA decreased MR mRNA levels in CA1 and CA3, decreased GR mRNA levels in DG, and negated all antagonist‐induced increases of ACR mRNAs. Cell counts quantifying KA damage indicated increased CA3 vulnerability to KA insult after treatment with MR antagonist spironolactone but demonstrated no significant cell loss in any other group or region. These results demonstrate dynamic regulation of hippocampal MR and GR mRNAs after ACR antagonist treatment and kainate toxicity, underscoring the potential importance of MR and GR availability to neuronal viability after insult. J. Neurosci. Res. 64:277–283, 2001. © 2001 Wiley‐Liss, Inc.
Role of oxidative stress in the apoptotic cell death of cultured cerebellar granule neurons
Authors: Valencia Antonio , Morán Julio 
Published: October 2004

AbstractWhen cultured cerebellar granule neurons (CGN) are transferred from 25 mM KCl (K25) to 5 mM KCl (K5) caspase‐3 and caspase‐8, but not caspase‐1 or caspase‐9,activities are induced and cells die apoptotically. CGN death was triggered by a [Ca2+]imodification when [Ca2+]iwas reduced from 300 nM to 50 nM in a K5 medium. The [Ca2+]ichanges were followed by an increase in ROS levels. The generation of both cytosolic and mitochondrial reactive oxygen species (ROS) occurred at three different times, 10 min, 30 min and 3–4 hr but only those ROS produced after 3–4 hr are involved in the process of cell death. When CGN cultured in a K5 medium are treated with different antioxidants like scavengers of ROS (mannitol, DMSO) or antioxidant enzymes (superoxide dismutase and catalase) phosphatidylserine translocation, caspase activity, chromatin condensation and cell death is markedly diminished. The protective effect of antioxidants is not mediated through a modification in [Ca2+]i. Caspase activation, PS translocation and chromatin condensation were downstream of ROS production. In contrast to H2O2, ROS produced by a xanthine/xanthine oxidase system in CGN cultured in K25 were able to directly induce caspase‐3 activation and death that resulted sensitive to z‐VAD, a caspase inhibitor. These findings indicate that a reduction in [Ca2+]itriggers CGN death by inducing a generation of ROS after 3–4 hr, which could play a critical role in the initial phases of the apoptotic process including PS translocation, chromatin condensation and the activation of initiator and executor caspases. J. Neurosci. Res. 64:284–297, 2001. © 2001 Wiley‐Liss, Inc.
Identifying genes involved in regulating differentiation of neuroblastoma cells
Authors: Hovland Alicia Rudie , Nahreini Piruz , Andreatta Cynthia P. , Edwards‐Prasad Judith , Prasad Kedar N. 
Published: October 2004

AbstractThe genes regulating the induction of differentiation in neurons are not definitively known. Some neuronal tumors retain the ability to differentiate into mature, functional neurons in response to pharmacological agents, despite the presence of genetic anomalies. We hypothesized that some of the genes whose expression is altered between undifferentiated and differentiated states may be those responsible for inducing differentiation. To investigate this, we used a mouse neuroblastoma (NB) cell line, NBP2, in which ≥90% of the cells in the culture terminally differentiate upon elevation of intracellular adenosine 3′,5′‐cyclic monophosphate (cAMP) levels. Gene expression was analyzed using cDNA array blots containing 588 known genes. mRNA from cultures of undifferentiated and differentiated NB cells was used to make cDNA probes for blot hybridization. We identified several genes that are predominantly expressed in either undifferentiated or differentiated NB cells. In addition, numerous genes are moderately up‐ or down‐regulated during differentiation of NB cells. We identified the N‐myc protooncogene, cyclin B1, and protease nexin 1 as genes that are expressed in undifferentiated NB cells and whose levels are significantly down‐regulated upon differentiation. In contrast, the c‐fes and c‐fos protooncogenes and the RAG‐1 gene activator are genes whose expression is significantly up‐regulated during differentiation of NB cells. These findings were confirmed by RT‐PCR analysis. The transcript size and expression level of N‐myc, cyclin B1, protease nexin 1, c‐fes, and c‐fos were verified by Northern blotting. These genes may represent key mediators involved in the regulation of NB cell differentiation. J. Neurosci. Res. 64:302–310, 2001. © 2001 Wiley‐Liss, Inc.
Molecular organization of the nodal region is not altered in spontaneously diabetic BB‐Wistar rats
Authors: Brown Alexander A. , Xu Theodore , Arroyo Edgardo J. , Levinson S. Rock , Brophy Peter J. , Peles Elior , Scherer Steven S. 
Published: October 2004

AbstractWe examined the organization of the molecular components of the nodal region in spontaneously diabetic BB‐Wistar rats. Frozen sections and teased fibers from the sciatic nerves were immunostained for nodal (voltage‐gated Na+ channels, ankyrinG, and ezrin), paranodal (contactin, Caspr, and neurofascin 155 kDa), and juxtaparanodal (Caspr2, the Shaker‐type K+ channels Kv1.1 and Kv1.2, and their associated subunit Kvβ2) proteins. All of these proteins were properly localized in myelinated fibers from rats that had been diabetic for 15–44 days, compared to age‐matched, nondiabetic animals. These results demonstrate that the axonal membrane is not reorganized, so nodal reorganization is not likely to be the cause of nerve conduction slowing in this animal model of acute diabetes. J. Neurosci. Res. 65:139–149, 2001. © 2001 Wiley‐Liss, Inc.
Ezrin, radixin, and moesin are components of Schwann cell microvilli
Authors: Scherer Steven S. , Xu Theodore , Crino Peter , Arroyo Edgardo J. , Gutmann David H. 
Published: October 2004

AbstractEzrin, radixin, and moesin (ERM proteins), as well as the neurofibromatosis 2 (NF2) tumor suppressor merlin/schwannomin, all belong to the protein 4.1 family, yet only merlin is a tumor suppressor in Schwann cells. To gain insight into the possible functions of ERM proteins in Schwann cells, we examined their localization in peripheral nerve, because we have previously shown that merlin is found in paranodes and in Schmidt‐Lanterman incisures. All three ERM proteins were highly expressed in the microvilli of myelinating Schwann cells that surround the nodal axolemma as well as in incisures and cytoplasmic puncta in the vicinity of the node. In all of these locations, ERM proteins were colocalized with actin filaments. In contrast, ERM proteins did not surround nodes in the CNS. The colocalization of ERM proteins with actin indicates that they have functions different from those of merlin in myelinating Schwann cells. J. Neurosci. Res. 65:150–164, 2001. © 2001 Wiley‐Liss, Inc.
Improvement of macromolecular clearance via lymph flow in hamster gingiva by low‐power carbon dioxide laser‐irradiation
Authors: Shimotoyodome Akira , Okajima Miyuki , Kobayashi Hisataka , Tokimitsu Ichiro , Fujimura Akira 
Published: October 2004

AbstractBackground and ObjectiveAlthough therapeutic effects of low‐power laser‐irradiation on periodontal disease have been reported, little is known about the biological effects of laser‐irradiation in the gingiva. Recently we reported that topical warming stimulated macromolecular clearance via lymph flow in hamster gingiva. This study was conducted to investigate whether low‐power laser‐irradiation affects macromolecular clearance via the lymph flow in the gingiva.Study Design/Materials and MethodsWe injected 14C‐methylated albumin into the mandibular gingiva of anesthetized hamsters followed by topical carbon dioxide (CO2) laser‐irradiation (30 seconds, 0.5–1.5 W). We measured the clearance of radiolabeled albumin from the gingiva and its drainage into submandibular lymph nodes during 10 minutes.ResultsThe clearance of the radiolabeled albumin from the gingiva and the influx into the submandibular lymph nodes were increased by CO2 laser‐irradiation.ConclusionLow‐power CO2 laser‐irradiation improves macromolecular clearance via the lymph flow in hamster gingiva. Lasers Surg. Med. 29:442–447, 2001. © 2001 Wiley‐Liss, Inc.
Photothermal properties of shape memory polymer micro‐actuators for treating stroke*
Authors: Maitland Duncan J. , Metzger Melodie F. , Schumann Daniel , Lee Abraham , Wilson Thomas S. 
Published: October 2004

AbstractBackground and ObjectivesIn this paper the photothermal engineering issues of novel shape memory polymer (SMP) microactuators for treating stroke are presented. The engineering issues for using lasers to heat and subsequently actuate these SMP devices are presented in order to provide design criteria and guidelines for intravascular, laser activated SMP devices.Materials and MethodsA total of three devices will be presented: two interventional ischemic stroke devices (coil and umbrella) and one device for releasing embolic coils (microgripper). The optical properties of SMP, methods for coupling laser light into SMP, heating distributions in the SMP devices, and the impact of operating the thermally activated material in a blood vessel are presented.ResultsActuating the devices requires device temperatures in the range of 65–85°C. Attaining these temperatures under flow conditions requires critical engineering of the SMP optical properties, optical coupling into the SMP, and device geometries.ConclusionLaser‐activated SMP devices are a unique combination of laser‐tissue and biomaterial technologies. Successful deployment of the microactuator requires well‐engineered coupling of the light from the diffusing fiber through the blood into the SMP. Lasers Surg. Med. 30:1–11, 2002. © 2002 Wiley‐Liss, Inc.
Vascular response to laser photothermolysis as a function of pulse duration, vessel type, and diameter: Implications for port wine stain laser therapy
Authors: Kimel Sol , Svaasand Lars O. , Cao Danielle , Hammer‐Wilson Marie J. , Nelson J. Stuart 
Published: October 2004

AbstractBackground and ObjectiveTreatment of port wine stains (PWS) by photothermolysis can be improved by optimizing laser parameters on an individual patient basis. We have studied the critical role of pulse duration (tp) on the treatment efficacy.Study Design/Materials and MethodsThe V‐beam laser (Candela) allowed changing tp over user‐specified discrete values between 1.5 and 40 milliseconds by delivering a series of 100 microsecond spikes. For the 1.5 and 3 millisecond pulses, three spikes were observed at intervals tp/2 and for tp ≥ 6 milliseconds, four spikes separated by tp/3. The ScleroPlus laser (Candela) has a smooth output over its fixed 1.5 milliseconds duration. Blood vessels in the chick chorioallantoic membrane (CAM) were irradiated at fixed wavelength (595 nm), spot size (7 mm), radiant exposure (15 Jcm−2), and at variable tp. The CAM contains an extensive microvascular network ranging from capillaries with diameter D < 30 μm to blood vessels of D ≈ 120 μm. The CAM assay allows real‐time video documentation, and observation of blood flow in pre‐capillary arterioles (A) and post‐capillary venules (V). Vessel injury was graded from recorded videotapes. Mathematical modeling was developed to interpret results of vessel injury when varying tp and D. A modified thermal relaxation time was introduced to calculate vessel wall temperature following laser exposure.ResultsArterioles. For increasing tp, overall damage was found to decrease. For fixed tp, damage decreased with vessel size. Venules. For all D, damage was smaller than for corresponding arterioles. There was no dependence of damage on tp. For given tp, no variation of damage with D was observed. Photothermolysis due to spiked (V‐beam) vs. smooth (Scleroplus) delivery of laser energy at fixed tp (1.5 milliseconds), showed similar vessel injuries for al values of D (P>0.05).ConclusionsThe difference between initial arteriole and venule damage could be explained by the threefold higher absorption coefficient at 595 nm in (oxygen‐poor!) arterioles. In human patients, PWS consist of ectatic venules (characterized by higher absorption), so that these considerations favor the use of 595‐nm irradiation for laser photothermolysis. For optimal treatment of PWS it is proposed that tp be between 0.1 and 1.5 milliseconds. This is based on a modified relaxation time τd′, defined as the time required for heat conduction into the full thickness of the vessel wall, which is assumed to have a thickness ΔD ≈ 0.1D. The corresponding τd′ will be a factor of about six smaller than given in the literature. For vessels with D between 30 and 300 μm, τd′ ranges from 0.1 to 1.5 milliseconds. Lasers Surg. Med. 30:160–169, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of the in vivo efficiency of photofrin II‐, mTHPC‐, mTHPC‐PEG‐ and mTHPCnPEG‐mediated PDT in a human xenografted head and neck carcinoma
Authors: Reuther Tobias , Kübler Alexander C. , Zillmann Uwe , Flechtenmacher Christa , Sinn Hannsjörg 
Published: October 2004

AbstractBackground and ObjectiveOne of the approaches to enhance the selectivity and efficiency of photodynamic therapy (PDT) was the conjugation of the photosensitizer meta‐tetrahydroxyphenylchlorin (mTHPC) to the water‐soluble polymer polyethylene glycol (PEG). Several studies have demonstrated that mTHPC‐PEG has a higher selectivity and a longer circulating half‐life than free mTHPC, whereas no in vivo effect of this benefit could be seen.Study Design/Materials and MethodsIn a model of RAG‐2‐mice bearing a human oral squamous cell carcinoma xenograft (XF 354), the in vivo efficiency assessed as growth retardation or remission caused by Photofrin II and free mTHPC was compared with mTHPC coupled in two different ways to polyethylene glycol (PEG). One hundred and fourty‐nine female RAG‐2‐mice were randomised into one control group and 13 therapy groups. Treatment parameters were adapted from those routinely applied in animal studies.ResultsPhotofrin II‐mediated PDT and mTHPC‐mediated PDT were both in vivo highly effective, whereas mTHPC induced less scars. The in vivo results after mTHPC‐PEG‐mediated PDT were disappointing, whereas the effectiveness of mTHPCnPEG‐mediated PDT, a newly coupled macromolecular photosensitizer, were promising.ConclusionsThese results demonstrated the impact of the method of linkage between the photoactive agent mTHPC and polyethylene glycol (PEG) upon the in vivo effectiveness. mTHPC and mTHPCnPEG are promising photosensitizers for the future, especially for the cosmetic treatment needs of head and neck surgery. Lasers Surg. Med. 29:314–322, 2001. © 2001 Wiley‐Liss, Inc.
Laser‐induced shock waves enhance sterilization of infected vascular prosthetic grafts
Authors: Nigri Giuseppe R. , Tsai Sheaumei , Kossodo Sylvie , Waterman Peter , Fungaloi Patrick , Hooper David C. , Doukas Apostolos G. , LaMuraglia Glenn M. 
Published: October 2004

AbstractBackground and ObjectiveBacteria that cause infection of vascular prosthetic grafts produce an exopolysaccharide matrix known as biofilm. Growth in biofilms protects the bacteria from leukocytes, antibodies and antimicrobial drugs. Laser‐generated shock waves (SW) can disrupt biofilms and increase drug penetration. This study investigates the possibility of increasing antibiotic delivery and sterilization of vascular prosthetic graft.Study Design/Materials and MethodsStrains of Staphylococcus epidermidis and S. aureus were isolated from infected prosthetic grafts obtained directly from patients. Dacron grafts were inoculated with the isolated bacteria, which were allowed to form adherent bacterial colonies. The colonized grafts underwent the following treatments: (a) antibiotic (vancomycin) alone; (b) antibiotic and SW (c) saline only; and (d) saline and SW. Six hours after treatment, the grafts were sonicated, the effluent was cultured and the colony forming units (CFU) were counted.ResultsCFU recovered from control grafts colonized by S. epidermidis were comparable: saline, 3.05 × 108 and saline + SW 3.31 × 108. The number of S. epidermidis CFU diminished to 7.61 × 106 after antibiotic treatment but the combined antibiotic + SW treatment synergistically decreased CFU number to 1.27 × 104 (P < 0.001). S. aureus showed a higher susceptibility to the antibiotic: 2.26 × 106 CFU; antibiotic + SW treatment also had an incremental effect: 8.27 × 104 CFU (P < 0.001).ConclusionsThis study demonstrates that laser‐generated shock waves have no effects alone, but can enhance the effectiveness of antibiotics against bacteria associated with prosthetic vascular graft biofilms, suggesting that this treatment may be of value as adjunctive therapy for prosthetic graft infections. Lasers Surg. Med. 29:448–454, 2001. © 2001 Wiley‐Liss, Inc.
Sense making: Trojan horse? Pandora's box?
Authors: Craig‐Lees Margaret 
Published: October 2004

AbstractThis article examines the concept of sense making and its application to management disciplines. The ideas of Karl Weick are discussed in terms of their contribution to these disciplines. Two contributions are identified—the validation of the “agent” and the impact of the adoption of the sense‐making construct on current research paradigms, theory, and methodology. The theme of this article is that sense making, whose origin lies in constructivism, has been interpreted and applied within the social‐constructionist worldview. The consequence of this action is a heightening of epistemological discussion in the social and management sciences. © 2001 John Wiley & Sons, Inc.
The influence of topic involvement on mail‐survey response behavior
Authors: Van Kenhove Patrick , Wijnen Katrien , De Wulf Kristof 
Published: October 2004

AbstractIn this study the influence of topic involvement on mail‐survey response rate and speed was experimentally investigated. The results show that response rates for topics that are generally considered as high involvement were higher than for topics that are generally considered as low involvement. However, the speed of response did not differ between the two levels of topic involvement. Moreover, in terms of response rates an interesting interaction effect was observed: For the high‐involvement topic, the response rate showed a further positive and significant correlation with the within‐topic level of involvement, but this was not the case for the low‐involvement topic. The implications of these findings to nonresponse bias in mail survey research are discussed. © 2002 Wiley Periodicals, Inc.
Response of metabolites with coupled spins to the STEAM sequence
Authors: Thompson Richard B. , Allen Peter S. 
Published: October 2004

AbstractThis article demonstrates that a numerical solution of the full quantum mechanical equations for all metabolites with coupled spins is an efficient and accurate means, first, of predicting the optimum STEAM sequence design for quantifying any target metabolite in brain, and, second, for providing the basis lineshapes and yields of these metabolites to facilitate their accurate quantification. Using as illustrations the weakly coupled AX3 system of lactate, the ABX aspartyl group of N‐acetylaspartate, which has only two strongly coupled spins, and the much larger strongly coupled AMNPQ glutamyl group of glutamate, the numerical solutions for the response to STEAM highlight the principal source of response variability, namely, the evolution of and transfer between zero quantum terms during the mixing time, TM. These highlights include the rapid oscillations of zero quantum terms due to the chemical shift difference of the coupled spins, the proliferation of oscillating zero order terms due to strong coupling, and the serendipitous smoothing of the response as the number of strongly coupled spins increases. The numerical solutions also demonstrate that the design of the selective 90° pulses is a far less critical factor in determining the response than was the case for the selective 180° pulses of the PRESS sequence (Thompson and Allen, Magn Reson Med 1999;41:1162–1169). The veracity of the method is demonstrated both in phantom solutions and in the parietal lobe of a normal human brain. Magn Reson Med 45:955–965, 2001. © 2001 Wiley‐Liss, Inc.
Application of 19F chemical shift imaging in studies of mice with orally administered 5‐fluorouracil
Authors: Kuribayashi Hideto , Doi Yoshihiro , Kanazawa Yoko 
Published: October 2004

AbstractIn vivo quantitative metabolic mapping is an ideal tool for pharmacokinetic studies. Oral 5‐fluorouracil (5‐FU) and its metabolites in mice were imaged simultaneously by the 19F fast spin echo (FSE) sequence using interleaved frequency selection at 9.4T. However, 5‐FU images in the small intestine have never been obtained regardless of concentration. The reason for the discrepancy between image intensity and concentration was T2. At a pH above 6, a dramatic decrease in T2 of a 19F 5‐FU signal in an aqueous solution was found; T2 was shorter in the small intestine (14 ms) than in the stomach (52 ms). The 19F CSI sequence in FID sampling mode was employed for detecting short T2 signals. With a 13‐min resolution time, the detection of the 5‐FU signals in the region of the small intestine (0.6 mmol/kg) was successful with a 5 × 5 mm2 in‐plane resolution. Furthermore, two signals separated by 2 ppm were clearly distinguishable, but failed to be separately detectable with the 19F FSE sequence. For quantitative simultaneous monitoring of 5‐FU and its metabolites of varying T2, the 19F CSI sequence in FID sampling mode was found to be superior to the 19F FSE sequence. Magn Reson Med 46:864–869, 2001. © 2001 Wiley‐Liss, Inc.