bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined chemical (ozone) and biological treatment of polychlorinated biphenyls (PCBs) adsorbed to sediments
Authors: Cassidy Daniel , Hampton Duane , Kohler Steven 
Published: August 2002

AbstractLaboratory experiments were conducted to test the feasibility of ozone sparging to oxidize PCBs in sediments, and to determine the organic acid content and biodegradability of the oxidation products. Two PCBs were tested; 2‐,2′‐dichlorobiphenyl (DCB) and 2‐,3‐,4‐,2′‐,3′‐,4′‐hexachlorobiphenyl (HCB). DCB and HCB were allowed to adsorb onto solids in slurries of pure kaolinite and river sediments containing 2% native organic matter (NOM). Ozone was sparged through the slurries while concentrations of PCBs and Cl−, and chemical oxygen demand (COD) were measured with time. Gas chromatography/mass spectrometry (GC/MS) was used to identify the organic acids produced from the reaction of ozone with DCB and HCB. After sparging, the liquid was placed in bioreactors with inoculum from a domestic wastewater treatment plant and nutrients. Ozone sparging in the kaolinite slurries removed 94% of HCB and 97% of DCB in 30 days. In contrast, 55 days were required to achieve the same PCB removal in river sediment slurries. Ozone doses per g of DCB and HCB in kaolinite were 19 g and 30 g, respectively. Doses were 13–14 times greater in river sediments. Formic and oxalic acids were ozonation products of both PCBs. Specific ozonation products of DCB and HCB were 2‐hydroxybenzoic acid and 2,3,4‐trihydroxybenzoic acid, respectively. The results show that ozone caused ring cleavage of PCBs and stoichiometric replacement of Cl with OH groups. Over 93% of the soluble COD from ozone sparging was biodegraded within 20–26 days in the bioreactors.© 2002 Society of Chemical Industry
Gene expression in the supraoptic nucleus
Authors: Ueta Yoichi , Levy Andrew , Lightman Stafford L. 
Published: August 2002

AbstractThe magnocellular neurosecretory cells (MNCs) in the supraoptic nucleus (SON) express multiple kinds of genes, including not only the classical hormones arginine vasopressin (AVP) and oxytocin (OXT), but also other physiologically active substances including neuropeptides, their receptors, and nitric oxide (NO) synthase, the rate‐limiting enzyme in the synthesis of NO under physiological condition. For example, osmotic stimuli such as dehydration and chronic salt loading cause a wide range of changes of the expression levels of the genes and marked induction of the expression of the genes in the SON. The expression of the NO synthase gene in the SON under physiological conditions is reviewed. Microsc. Res. Tech. 56:158–163, 2002. © 2002 Wiley‐Liss, Inc.
Application of immunoelectron microscopy techniques in the diagnosis of phytoplasma diseases
Authors: Musetti Rita , Loi Nazia , Carraro Luigi , Ermacora Paolo 
Published: August 2002

AbstractAn immunoelectron microscopy technique was applied to label Chrysanthemum leuchanthemum phytoplasma in infected leaf tissues of Chrysanthemum leuchanthemum L. and Catharanthus roseus L. plants. Specific monoclonal antibodies at different dilutions and secondary antimouse antibody conjugated with colloidal gold particles of different sizes were used. The monoclonal antibodies demonstrated their specificity against the antigen; immunocytological methods permitted the precise localization and identification of phytoplasmas in thin sections from infected tissues. Microsc. Res. Tech. 56:462–464, 2002. © 2002 Wiley‐Liss, Inc.
Unraveling the enigma: The role of melatonin in seasonal processes in birds
Authors: Bentley George E. 
Published: August 2002

AbstractBirds, unlike mammals, do not use the annual profile of pineal melatonin secretion to coordinate their reproductive efforts with a favorable time of year. Melatonin in birds mediates the entrainment of circadian activity rhythms, and thus helps to time hatching of eggs and facilitate migration. However, the role of melatonin as a reliable indicator of day length for seasonal processes has remained equivocal for many years. Recently, the influence of melatonin on two physiological processes involved in aspects of seasonal reproduction has been identified in European starlings: 1) the regulation of seasonal changes in immune function, and 2) neuroplasticity in the song control system. Melatonin can enhance cell‐mediated immune function and acts as an inhibitory hormone on the song control system. Melatonin receptor (MelR) density in a forebrain song control nucleus, Area X, is regulated as a function of reproductive state; there is marked downregulation of MelR in Area X during the breeding season in starlings. Seasonal regulation of immune function and neural plasticity within the song control system, and the efficacy of the action of melatonin on these two processes, appears to be modified by the same central, thyroid‐dependent mechanism that controls the reproductive state of birds. These data indicate that the interaction of day length and hormones of different classes affects the ability of melatonin to affect seasonal processes in birds. The downstream consequences of MelR regulation within the song control system are discussed with regard to the cellular action of melatonin and its possible interaction with immediate‐early genes and transcription factors. Microsc. Res. Tech. 53:63–71, 2001. © 2001 Wiley‐Liss, Inc.
Cholinergic‐nitrergic transmitter mechanisms in the cerebral circulation
Authors: Lee Tony J.F. , Liu Jie , Evans M. Steven 
Published: August 2002

AbstractCerebral blood vessels from several species are innervated by vasodilator nerves. Acetylcholine (ACh) released from parasympathetic cholinergic nerves was first suggested to be the transmitter for vasodilation. Results from pharmacological studies in isolated cerebral arterial ring preparations, however, have demonstrated that nitric oxide (NO) but not ACh mediates the major component of neurogenic vasodilation. More recently, ACh and NO have been shown to co‐release from the same cholinergic‐nitrergic nerves, and that ACh acts as a presynaptic transmitter in modulating NO release. In this communication, evidence for the neuronal origin of NO and possible role of ACh in modulating NO release in large cerebral arteries at the base of the brain will be discussed. Microsc. Res. Tech. 53:119–128, 2001. © 2001 Wiley‐Liss, Inc.
Physiology of meningeal innervation: Aspects and consequences of chemosensitivity of meningeal nociceptors
Authors: Ebersberger Andrea 
Published: August 2002

AbstractUp to now, the cause of most types of headaches is unknown. Why headache starts or why it fades away during hours or a few days is still a mystery. This phenomenon makes headache unique compared to other pain states. For long it has been known that during headache sensory structures in the meninges are activated. But it was not until the last two decades that scientists investigated the physiology of the sensory innervation of the meninges. Animal models and in vitro preparations have been developed to get access to the meninges and to determine the response properties of meningeal afferents. Although animals hardly can tell their pain, blood pressure measurements and observations of behaviour in two models of headache suggest that such animal models are valid and may add remarkable information to our understanding of human headache. Since chemicals and endogenous inflammatory mediators may alter sensory thresholds and responsiveness of neurons, they are putative key molecules in triggering pathophysiological sensory processing. This review briefly summarizes what is known about the chemosensitivity of meningeal innervation. Microsc. Res. Tech. 53:138–146, 2001. © 2001 Wiley‐Liss, Inc.
Neurogenic inflammation in the context of migraine
Authors: Williamson David J. , Hargreaves Richard J. 
Published: August 2002

AbstractDespite considerable research into the pathogenesis of idiopathic headaches, such as migraine, the pathophysiological mechanisms underlying them remain poorly understood. Although it is well established that the trigeminal nerve becomes activated during migraine, the consequences of this activation remain controversial. One theory, based on preclinical observations, is that activation of trigeminal sensory fibers leads to a painful neurogenic inflammation within the meningeal (dural) vasculature mediated by neuropeptide release from trigeminal sensory fibres and characterized by plasma protein extravasation, vasodilation, and mast cell degranulation. Effective antimigraine agents such as ergots, triptans, opioids, and valproate inhibit preclinical neurogenic dural extravasation, suggesting that this activity may be a predictor of potential clinical efficacy of novel agents. However, several clinical trials with other agents that inhibit this process preclinically have failed to show efficacy in the acute treatment of migraine in man. Alternatively, it has been proposed that painful neurogenic vasodilation of meningeal blood vessels could be a key component of the inflammatory process during migraine headache. This view is supported by the observation that jugular plasma levels of the potent vasodilator, calcitonin gene‐related peptide (CGRP) are elevated during the headache and normalized by successful sumatriptan treatment. Preclinically, activation of trigeminal sensory fibers evokes a CGRP‐mediated neurogenic dural vasodilation, which is blocked by dihydroergotamine, triptans, and opioids but unaffected by NK1 receptor antagonists that failed in clinical trials. These observations suggest that CGRP release with associated neurogenic dural vasodilation may be important in the generation of migraine pain, a theory that would ultimately be tested by the clinical testing of a CGRP receptor antagonist. Microsc. Res. Tech. 53:167–178, 2001. © 2001 Wiley‐Liss, Inc.
GDNF improves cerebellar Purkinje neuron function in aged F344 rats
Authors: Bickford P.C. , Bowenkamp K. , Taglialatela G. , Hoertig G. , Granholm A.‐C. 
Published: August 2002

AbstractAging is associated with a decline in the function of β‐adrenergic receptor responses in the cerebellum. This decline in noradrenergic receptor sensitivity may underlie some of the accompanying age‐related declines in motoric learning behaviors. Glial cell line–derived neurotrophic factor (GDNF) has been reported to prevent the degeneration of noradrenergic neurons following neurotoxic lesions. Thus, it was of interest to examine if GDNF would have a beneficial effect on age‐related declines in noradrenergic function. Eighteen‐month‐old F344 rats were injected with 500 μg GDNF in 20 μl into the cisterna magna. Three weeks following GDNF or vehicle treatment, rats were tested on a motor coordination task and then examined electrophysiologically under urethane anesthesia. GDNF did not produce an improvement in performance on an inclined balance beam or an accelerating rotorod. In young (3‐month‐old) F344 rats isoproterenol (ISO) will increase GABAergic inhibitions in the majority of cells examined; however, in aged rats only about 30% of neurons demonstrate this phenotype. In the aged rats treated with GDNF, ISO was able to increase GABAergic inhibitions in greater than 75% of the neurons tested, thus returning the neurons to a young phenotype. We examined the brains for expression of bcl‐2, which has been shown to be increased in the aged cerebellum. GDNF was able to down‐regulate this neuronal signal. Thus, intra‐cisterna magna delivery of GDNF to aged rats improved β‐adrenergic receptor function and reduced stress related signaling of bcl‐2 in the aged F344 rats to a level similar to that observed in young rats. Microsc. Res. Tech. 54:309–316, 2001. © 2001 Wiley‐Liss, Inc.
Role of steroidogenic factor 1 and aromatase in temperature‐dependent sex determination in the red‐eared slider turtle
Authors: Crews David , Fleming Alice , Willingham Emily , Baldwin Ryan , Skipper James K. 
Published: August 2002

AbstractRed‐eared slider turtles are genetically bipotential for sex determination. In this species, as in many other reptiles, incubation temperature of the egg determines gonadal sex. At higher incubation temperatures females are produced and increasing temperature appears to increase estrogen production in the embryonic brain. Treatment of eggs incubating at a male‐producing temperature with exogenous estrogen causes ovaries to form. At a female‐biased incubation temperature, prevention of estrogen biosynthesis or administration of nonaromatizable androgens results in the development of testes. In mammals, steroidogenic factor 1 (SF‐1) regulates most genes required for estrogen biosynthesis, including aromatase. In both mammals and red‐eared sliders, SF‐1 is differentially expressed in males and females during gonadogenesis. We have examined both SF‐1 gene expression and aromatase activity in embryos incubating at different temperatures and after manipulation to change the course of gonadal development. Our findings indicate a central role for SF‐1 in enacting the effect of estrogen. Estrogen treatment directly or indirectly downregulates SF‐1 and, ultimately, causes development of females. The inhibition of estrogen results in upregulation of SF‐1 and male hatchlings. Thus, SF‐1 may lie at the center of one molecular crossroad in male versus female differentiation of the red‐eared slider. J. Exp. Zool. 290:597–606, 2001. © 2001 Wiley‐Liss, Inc.
Transcription pattern of ribosomal protein L26 during anoxia exposure in Littorina littorea
Authors: Larade Kevin , Nimigan Andre , Storey Kenneth B. 
Published: August 2002

AbstractDifferential screening of a hepatopancreas cDNA library derived from the marine snail Littorina littorea yielded a 421‐bp clone coding for ribosomal protein L26 that was up‐regulated during anoxia exposure. The deduced amino acid sequence, containing 144 residues with a predicted molecular weight of 17 kDa, showed 80% amino acid sequence identity to the mammalian ribosomal protein L26. Analysis of hepatopancreas and foot muscle samples from a time course of anoxia exposure showed a maximal transcript increase of 4‐ and 3‐fold after 96 hr and 48 hr, respectively, relative to normoxic animals, with a subsequent decrease in transcript levels during normoxic recovery. Nuclear run‐off assays confirmed the observed transcriptional up‐regulation of L26 during anoxia. Organ culture experiments were performed to determine a possible pathway of up‐regulation of L26, with data indicating a putative role for cGMP in signal transduction. The transcriptional up‐regulation of L26 during anoxia may stabilize the existing mRNA pool, via a possible cGMP‐mediated signaling cascade, until oxygen reappears and protein synthesis resumes. J. Exp. Zool. 290:759–768, 2001. © 2001 Wiley‐Liss, Inc.
ICTs in development—who benefits? Use of geographic information systems on the Cato Manor Development project, South Africa
Authors: Odendaal Nancy 
Published: August 2002

AbstractThe focus on the digital divide raises important questions with regards to the global impact of information technology. Technical inequalities are, however, often embedded in the development project where access to technological knowledge becomes a determining factor in the development process. This paper aims to uncover the use of geographic information systems (GIS) on the Cato Manor Development Project in Durban, South Africa. The focus will be on an instant where the legitimacy of the project was challenged by former residents, removed from the area during the Apartheid era, and the role of information technology in resolving that conflict. The paper will show that GIS is not necessarily a value‐free tool, but can influence development decisions contrary to the expectations of those affected by it. Copyright © 2002 John Wiley & Sons, Ltd.
Vertebrate limb development and possible clues to diversity in limb form
Authors: Tickle Cheryll 
Published: August 2002

AbstractChick embryos are good models for vertebrate development. The principles that underlie chick wing development have been discovered and there is increasing knowledge about the molecules involved. The importance of identifying molecules is that this provides a direct link to understanding the genetic basis of diversity in form. Chick wing development will be compared with limb development in other vertebrates. Possible mechanisms that could lead to variations in form, including limb reductions and limblessness, differences between fore‐ and hindlimbs, limb proportions, and interdigital webbing can be suggested. J. Morphol. 252:29–37, 2002. © 2002 Wiley‐Liss, Inc.
Larval and metamorphic development of the foregut and proboscis in the caenogastropod Marsenina (Lamellaria) stearnsii
Authors: Page L.R. 
Published: August 2002

AbstractThe specialized, postmetamorphic feeding structures of predatory caenogastropods evolved by changes to an ancestral caenogastropod developmental program that generated a planktotrophic larval stage followed by a herbivorous postmetamorphic stage. As part of a program of comparative studies aimed at reconstructing these developmental changes, I studied the development of the postmetamorphic feeding system of Marsenina stearnsii using histological sections for light microscopy and scanning and transmission electron microscopy. The feeding system of this species has two very different designs during ontogeny. The larval system uses ciliary effectors to capture and ingest microalgae, whereas the juvenile/adult system includes a proboscis, jaws, and radular apparatus for predation on ascidian zooids. The postmetamorphic foregut begins to develop during the early larval phase, but the anlagen does not interfere with larval feeding because it develops as an increasingly elaborate outpocketing from the ventral wall of the larval esophagus. At metamorphosis, an opening is created in the anterior tip of the prospective, postmetamorphic buccal cavity and the margins of this opening anneal with the metamorphically remodeled lips of the larval mouth. This process exposes the jaws, which differentiate within the buccal cavity prior to metamorphosis. As a working hypothesis, I suggest that rupture of the buccal cavity to the outside at metamorphosis was selected as a mechanism to allow precocious development of jaws in species where jaws enhanced feeding performance by young juveniles. The larval esophagus of M. stearnsii appears to be completely destroyed at metamorphosis. Larval esophageal cells have distinctive apical characteristics (cilia, blebbed microvilli, stacks of lamellae within the glycocalyx) and no cells having this signature persist through metamorphosis. Development of the proboscis and proboscis sac, which begins prior to metamorphosis, conforms to previous descriptions of pleurembolic proboscis development, although an acrembolic proboscis has been ascribed to members of the Lamellaroidea. J. Morphol. 252:202–217, 2002. © 2002 Wiley‐Liss, Inc.
Whole brain apparent diffusion coefficient histogram: A new tool for evaluation of leukoaraiosis
Authors: Mascalchi Mario , Tessa Carlo , Moretti Marco , Della Nave Riccardo , Boddi Vieri , Martini Sara , Inzitari Domenico , Villari Natale 
Published: August 2002

AbstractPurposeTo test whole brain apparent diffusion coefficient histogram analysis as an alternative approach to visual score for the assessment of leukoaraiosis (LA).Materials and MethodsT2 and diffusion weighted images were obtained in 15 elderly patients. LA extension was assessed on T2 weighted images by two observers using a semiquantitative visual score. Apparent diffusion coefficient (ADC) maps of the entire brain were generated and, after exclusion of the skull with manual tracing and of the cerebrospinal fluid (CSF) by application of a threshold value, whole brain (WB)‐ADC histogram was obtained. Moreover, a brain volume index (BVI) was calculated on ADC maps as (intracranial volume – CSF volume) /intracranial volume.ResultsThe kappa inter‐observer agreement for LA scoring was 0.69. Manual segmentation of the skull showed a mean inter‐operator coefficient of variation below 3%. The median value of whole brain ADC histogram directly correlated with LA extension (P = 0.013). Moreover a significant inverse correlation (P = 0.002) was found between WB‐ADC median value and BVI.ConclusionWB‐ADC histogram is a reproducible alternative tool for assessing LA extension and severity. J. Magn. Reson. Imaging 2002;15:144–148. © 2002 Wiley‐Liss, Inc.
Utilizing SENSE to achieve lower station sub‐millimeter isotropic resolution and minimal venous enhancement in peripheral MR angiography
Authors: Maki Jeffrey H. , Wilson Gregory J. , Eubank William B. , Hoogeveen Romhild M. 
Published: August 2002

AbstractPurposeTo use the parallel imaging technique, sensitivity encoding (SENSE), to increase spatial resolution and decrease venous contamination in peripheral magnetic resonance angiography (MRA).Materials and MethodsMoving table, single‐bolus peripheral contrast‐enchanced (CE) ‐MRA was performed on nine patients. Manual table movement combined with SENSE in the upper station allowed for more rapid overall scan coverage such that acquisition of the lower station began 34 seconds after aortic contrast arrival. True sub‐ millimeter isotropic resolution was achieved in the lower station.ResultsDiagnostic MR angiograms of all three stations were obtained in all nine patients. Venous enhancement did not confound interpretation in any case. Sub‐millimeter lower station resolution provided excellent vascular detail.ConclusionDecreased delay time between upper and lower station acquisition in single bolus peripheral MR angiograms, now possible using parallel imaging techniques, combined with lower station sub‐millimeter resolution may decrease venous contamination and increase overall interpretability, thus increasing clinical acceptance of peripheral MRA. J. Magn. Reson. Imaging 2002;15:484–491. Published 2002 Wiley‐Liss, Inc.
The OptiMARK clinical development program: Summary of safety data
Authors: Brown Jeffrey J. , Kristy Rita M. , Stevens Gary R. , Pierro Joseph A. 
Published: August 2002

AbstractPurposeTo describe and summarize the safety data from the OptiMARK clinical development program.Materials and MethodsIn the 18 clinical studies comprising the clinical program, doses ranging from 0.1 to 0.7 mmol/kg were administered to healthy adult volunteers, patients with hepatic or renal impairment, and patients with confirmed or highly suspected central nervous system (CNS), liver, breast, vascular, bone, or soft tissue pathologies. A total of 2038 injections of OptiMARK, Magnevist, or placebo were administered to 1684 subjects. Safety assessments were performed at appropriate intervals during all Phase 1, 2, and 3 studies.ResultsOf the 1684 subjects exposed to a study drug or placebo in the clinical development program, 646 subjects experienced 1293 adverse events. Thirty‐one percent of the OptiMARK injections were associated with an adverse event. In comparison, 35% of Magnevist injections and 48% of placebo injections were associated with at least one adverse event.ConclusionsOptiMARK was safe and well‐tolerated with a safety profile similar to that of Magnevist. J. Magn. Reson. Imaging 2002;15:446–455. © 2002 Wiley‐Liss, Inc.