bluuebunny/crossref_metadata_2025 huggingface dataset:
Reciprocal regulation of tissue‐type and urokinase‐type plasminogen activators in the differentiation of murine preadipocyte line 3T3‐L1 and the hormonal regulation of fibrinolytic factors in the mature adipocytes
Authors: Seki Taiichiro , Miyasu Tomoko , Noguchi Toshinori , Hamasaki Ayumi , Sasaki Rika , Ozawa Yukiko , Okukita Kaoru , Declerck Paul J. , Ariga Toyohiko
Published: August 2002

Adipose tissue expresses a variety of genes including tumor necrosis factor α and type‐1 plasminogen activator inhibitor (PAI‐1); and these factors, produced by adipocytes, may be associated with the risk of coronary events in obesity. In this study, we characterized the production of fibrinolytic factors including tissue‐type plasminogen activator (tPA), urokinase‐type PA (uPA), and PAI‐1 in the differentiation of preadipocytes, and examined the hormonal regulation of these fibrinolytic factors in mature adipocytes. Mouse 3T3‐L1 preadipocytes were employed as a model of adipocytes. Adipocyte differentiation was induced by insulin, dexamethasone, and 3‐isobutyl‐1‐methyl xanthine (IBMX). α‐Glycerophosphate dehydrogenase (GPDH) activity and glucose transporter 4 (GLUT4) mRNA, indices for adipocyte maturation, were induced on Day 4, and gradually increased. GPDH activity reached its maximum level on Day 14. The level of tPA, a major PA in preadipocytes, dramatically decreased with differentiation. On the other hand, that of uPA reciprocally increased. PAI‐1 production was also dramatically induced concomitant with differentiation. In mature adipocytes, uPA production was dominant (25 μg/ml/24 h vs. 0.8 μg/ml/24 h for tPA). Total PA activity in the mature adipocytes was reduced by insulin or dexamethasone, but not by glucagon. Insulin, IBMX, and dexamethasone significantly decreased both uPA and tPA production, and increased PAI‐1 production. Glucagon had no effect on the production of these fibrinolytic factors. Our results reveal that uPA is one of the markers for the differentiation of 3T3‐L1 cells and that insulin, IBMX, and dexamethasone are potent regulators of the fibrinolytic activity in differentiated 3T3‐L1 cells, reciprocally affecting PA and PAI‐1 levels in them. © 2001 Wiley‐Liss, Inc.
Biosorption from aqueous solutions by eggshell membranes and Rhizopus oryzae: equilibrium and kinetic studies
Authors: Koumanova Bogdana , Peeva P , Allen Stephen J , Gallagher K A , Healy M G
Published: August 2002

This study assesses the use of eggshell membranes and Rhizopus oryzae as media for the biosorption of p‐chlorophenol (p‐CP), 2,4‐dichlorophenol (2,4‐DCP), 3,5‐dichlorophenol (3,5‐DCP), reactive dye and cadmium from aqueous solutions. The performance of the adsorbents was quantified by measuring the equilibrium uptake and the batch rate kinetics from solutions. The constants in the Freundlich, Langmuir and Redlich–Peterson isotherm models were calculated through the linearization of the equations and linear regression. The kinetics of the adsorption systems for cadmium and a reactive dye have been assessed in a batch stirred adsorber. The effect of the process parameters such as pH, adsorbate concentration, adsorbent dosage, adsorbent particle size, temperature and agitation speed are reported. The external mass transfer coefficients are reported for some different system conditions. Both materials are determined to be effective adsorbents and could find application in the treatment of contaminated wastestreams.

© 2002 Society of Chemical Industry
Structural effects of ion‐exchange membrane on the separation of L‐phenylalanine (L‐Phe) from fermentation broth using electrodialysis
Authors: Choi Jae‐Hwan , Oh Suk‐Jung , Moon Seung‐Hyeon
Published: August 2002

The effects of membrane structure on the separation of L‐phenylalanine (L‐Phe) by electrodialysis from a fermentation broth and on the fouling tendency were investigated in this study. Two anion‐exchange membranes (Neosepta AFX and AM‐1, Tokuyama, Japan) were selected and characterized using the chronopotentiometry method. For a fresh membrane, AFX showed a lower electrical resistance and a lower permselectivity than AM‐1. After being fouled with humic acid, however, the electrical resistance of AFX was higher than that of AM‐1. The L‐Phe selectivities for both membranes were lower than those of the fresh membranes. The result may be attributed to the structural difference between AFX and AM‐1 membranes. AFX has a lower repulsion force against the co‐ion and could be more strongly affected by the foulants than AM‐1 because AFX has a more porous structure than AM‐1. Experiments on the separation of L‐Phe from the fermentation broth were carried out using two different stack configurations, ie desalting electrodialysis and water‐splitting electrodialysis. It was observed that the recovery efficiency of L‐Phe through electrodialysis for 100 min reached 95% for AFX and 85% for AM‐1. In the desalting configuration of electrodialysis, the solution pH must be adjusted to alkaline conditions to recover the L‐Phe through the anion‐exchange membrane. On the contrary, it was possible to recover the L‐Phe without adjustment of the solution pH in the water‐splitting electrodialysis because OH− generated from the bipolar membrane converted neutral L‐Phe into an anion.

© 2002 Society of Chemical Industry
Removal of aqueous phenol catalysed by a low purity soybean peroxidase
Authors: Wilberg Katia , Assenhaimer Cristhiane , Rubio Jorge
Published: August 2002

The application of a low purity soybean peroxidase (LP‐SBP), obtained from wasted seed hulls, as catalyst for phenol polymerisation in aqueous solution in the presence of hydrogen peroxide is described. The polymers formed precipitate out from solution and may be readily separated by physico‐chemical techniques. LP‐SBP offers the advantage of reduced cost compared with horseradish peroxidase (HRP). The SBP activity in fresh hulls was greater than in aged hulls and was preserved at −10 °C. There was a linear correlation between initial phenol concentration (1, 2, 5 and 10 mmol dm−3) and the minimum dosage of LP‐SBP required to precipitate 95% of the phenolic polymers. Polyethylene glycol (molecular weight, 6000) at 1000 mg dm−3 did not extend LP‐SBP lifetime. At all phenol concentrations tested, a retention time of about 100 min was sufficient to achieve yields of 95%.

© 2002 Society of Chemical Industry
Quantitative sensory testing in gulf war veterans with chronic fatigue syndrome
Authors: Peckerman Arnold , Natelson Benjamin H. , Kipen Howard , Smith Sharon L. , Dahl Kristina , Pollet Chclaudia , Ottenweller John E.
Published: August 2002

The study assessed peripheral sensory function and its relation to self‐reported wartime exposures to potentially neurotoxic substances in Gulf War veterans with chronic fatigue syndrome (CFS). Male Gulf veterans fulfilling the 1994 CDC diagnostic criteria for CFS were compared with matched controls. Quantitative sensory testing was performed to establish thresholds of perception for the sense of light touch and radiant heat. The Devens survey was used to collect data on self‐reported exposures to by‐products of combustion and organophosphate compounds. Gulf veterans with CFS had elevated tactile but normal thermal thresholds compared with their controls. Sick veterans had greater rates of self‐reported exposures and/or noxious side effects for all assessed toxicants. Interestingly, both Gulf veteran groups, including those reporting no symptoms, had impaired perception of light touch when compared with age‐matched samples of non‐Gulf war veteran men. The results of this study are consistent with a hypothesis that Gulf veterans with CFS have a subtle neurological deficit that might reflect underlying peripheral neuropathy. The association between this deficit and self‐report of multiple potentially neurotoxic exposures suggests that war zone pollutants may be possible contributing factors. Copyright © 1999 John Wiley & Sons, Ltd.
Adrenomedullin in the central nervous system
Authors: Serrano J. , Alonso D. , Fernández A.P. , Encinas J.M. , López J.C. , Castro‐Blanco S. , Fernández‐Vizarra P. , Richart A. , Santacana M. , Uttenthal L.O. , Bentura M.L. , Martínez‐Murillo R. , Martínez A. , Cuttitta F. , Rodrigo J.
Published: August 2002

Adrenomedullin (AM) is a novel vasodilator peptide first purified from human pheochromocytoma by tracing its capacity to stimulate cAMP production in platelets. AM immunoreactivity is widely distributed in the central nervous system (CNS) and in the rat has been demonstrated by immunohistochemical techniques to be present in many neurons throughout the brain and spinal cord, as well as in some vascular endothelial cells and perivascular glial cells. Electron microscopy shows that the immunoreactivity is located mainly in the neuronal cytoplasm, but also occurs in the cell nucleus in some cells of the caudate putamen and olfactory tubercle. Biochemical analyses suggest that higher molecular forms, presumably precursor forms, may predominate over fully processed AM in some brain areas. The expression of AM immunoreactivity is increased in cortical neurons, endothelial cells, and perivascular processes after a simulation of ischemia by oxygen and glucose deprivation. Immunohistochemical, electrophysiological, and pharmacological studies suggest that AM in the CNS can act as a neurotransmitter, neuromodulator, or neurohormone, or as a cytoprotective factor in ischemic/hypoxic conditions, in addition to its vasodilator role. Microsc. Res. Tech. 57:76–90, 2002. © 2002 Wiley‐Liss, Inc.
Adrenomedullin has multiple roles in disease stress: Development and remission of the inflammatory response
Authors: Elsasser Ted H. , Kahl Stas
Published: August 2002

The upregulation of adrenomedullin (AM) gene expression and increases in systemic circulatory as well as localized tissue AM concentrations is well coordinated with the onset and progression of trauma, infection, and sepsis. As such, the coordinated change in AM suggests a key role for this peptide in the inflammatory response. By clinical definition, the process of inflammation constitutes an orchestrated cascade of localized tissue and systemic responses to immunological challenges. Classical responses to the onset of disease stresses are manifested in the timely elaboration of humoral, blood‐borne signal effectors (such as adrenocortical and locally produced tissue hormones, immune cytokines, and inorganic signals such as nitric oxide) as well as patterned migration and infiltration of circulating bone marrow‐derived cells (mononuclear cells such as monocyte‐macrophages and polymorphonuclear cells like neutrophils) largely associated with or delivered through the vascular system. The body's attempts to combat acute infection to restore homeostatic equilibrium are further compromised by underlying disease situations. Atherosclerosis, diabetes, and cardiovascular disease, as well as nutritional metabolic derangements and persistent subclinical infection perturb the regulatory feedback loops necessary for proper control of response effectors like hormones and cytokines. When imbalances occur, tissue necrosis can ensue as driven by free radical damage to cell components. A true appreciation of the inflammatory response can only be grasped through an integrative approach in which the relationship between the different physiological systems is viewed in terms of a changing, dynamic interaction. In essence, the inflammatory response can be thought of in three phases: a period of severity assessment, a period of remediation, and a period of homeostatic restoration. Indeed, AM has differential effects on cellular metabolism, immune function, endocrine function, and cardiovascular function. This peptide appears to play a pivotal role in both reprioritizing the biological needs of tissues and organs during the three phases of inflammatory response as well as a role in restoring homeostatic equilibrium to the body. Microsc. Res. Tech. 57:120–129, 2002. Published 2002 Wiley‐Liss, Inc.
Origin and co‐localization of nitric oxide synthase, CGRP, PACAP, and VIP in the cerebral circulation of the rat
Authors: Edvinsson Lars , Elsås Tor , Suzuki Norihiro , Shimizu Toshihiko , Jer‐Fu Lee Tony
Published: August 2002

The origin of perivascular nerve fibres storing nitric oxide synthase (NOS) and co‐localisation with perivascular neuropeptides were examined in the rat middle cerebral artery (MCA) by retrograde tracing with True Blue (TB) in combination with immunocytochemistry. Application of TB to the proximal part of the middle cerebral artery labelled nerve cell bodies ipsilaterally in the trigeminal, sphenopalatine, otic, and superior cervical ganglia. A few labelled cell bodies were seen contralaterally, suggesting bilateral innervation. In the parasympathetic sphenopalatine and otic ganglia, numerous TB‐labelled cell bodies contained neuronal NOS (C‐ and N‐terminal), vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase activating peptide (PACAP). In the trigeminal ganglion, almost all TB‐labelled cell bodies contained calcitonin gene‐related peptide (CGRP) but only a few cells contained NOS. In the superior cervical ganglion, the majority of the TB‐labelled nerve cells contained neuropeptide Y (NPY) but none of them contained NOS. Removal of the ipsilateral sphenopalatine ganglion caused a slight reduction in the number of perivascular VIP‐, PACAP‐, and NOS‐containing fibres after 3 days in the MCA while there was no difference at 2 and 4 weeks after the denervation as compared to control. This indicates that the parasympathetic VIP‐, PACAP‐, and NOS‐immunoreactive nerve fibres in the rat MCA originate from several sources. Microsc. Res. Tech. 53:221–228, 2001. © 2001 Wiley‐Liss, Inc.
Microglia in neuroregeneration
Authors: Aldskogius Håkan
Published: August 2002

Microglia has the potential to produce and release a range of factors that directly and/or indirectly promote regeneration in the injured nervous system. The overwhelming evidence indicates, however, that this potential is generally not expressed in vivo. Activated microglia may enhance neuronal degeneration following axotomy, thereby counteracting functional recovery. Microglia does not seem to contribute significantly to axonal outgrowth after peripheral nerve injury, since this process proceeds uneventful even if perineuronal microglia is eliminated. The phagocytic phenotype of microglia is highly suppressed during Wallerian degeneration in the central nervous system. Therefore, microglia is incapable of rapid and efficient removal of myelin debris and its putative growth inhibitory components. In this way, microglia may contribute to regeneration failure in the central nervous system. Structural and temporal correlations are compatible with participation by perineuronal microglia in axotomy‐induced shedding of presynaptic terminals, but direct evidence for such participation is lacking. Currently, the most promising case for a promoting effect on neural repair by activated microglia appears to be as a mediator of collateral sprouting, at least in certain brain areas. However, final proof for a critical role of microglia in these instances is still lacking. Results from in vitro studies demonstrate that microglia can develop a regeneration supportive phenotype. Altering the microglial involvement following neural injury from a typically passive or even counterproductive state and into a condition where these cells are actively supporting regeneration and plasticity is, therefore, an exciting challenge and probably a realistic goal. Microsc. Res. Tech. 54:40–46, 2001. © 2001 Wiley‐Liss, Inc.
Pituitary adenylate cyclase‐activating polypeptide and its receptors in amphibians
Authors: Yon Laurent , Alexandre David , Montéro Maité , Chartrel Nicolas , Jeandel Lydie , Vallarino Mauro , Conlon J. Michael , Kikuyama Sakae , Fournier Alain , Gracia‐Navarro Francisco , Roubos Eric , Chow Billy , Arimura Akira , Anouar Youssef , Vaudry Hubert
Published: August 2002

Pituitary adenylate cyclase‐activating polypeptide (PACAP), a novel peptide of the secretin/glucagon/vasoactive intestinal polypeptide superfamily, has been initially characterized in mammals in 1989 and, only 2 years later, its counterpart has been isolated in amphibians. A number of studies conducted in the frog Rana ridibunda have demonstrated that PACAP is widely distributed in the central nervous system (particularly in the hypothalamus and the median eminence) and in peripheral organs including the adrenal gland. The cDNAs encoding the PACAP precursor and 3 types of PACAP receptors have been cloned in amphibians and their distribution has been determined by in situ hybridization histochemistry. Ontogenetic studies have revealed that PACAP is expresssed early in the brain of tadpoles, soon after hatching. In the frog Rana ridibunda, PACAP exerts a large array of biological effects in the brain, pituitary, adrenal gland, and ovary, suggesting that, in amphibians as in mammals, PACAP may act as neurotrophic factor, a neurotransmitter and a neurohormone. Microsc. Res. Tech. 54:137–157, 2001. © 2001 Wiley‐Liss, Inc.
Changes in central steroid receptor expression, steroid synthesis, and dopaminergic activity related to the reproductive cycle of the ring dove
Authors: Lea Robert W. , Clark Judith A. , Tsutsui Kazuyoshi
Published: August 2002

This review examines possible neural mechanisms involved in the expression of parental behavior in the ring dove, Streptopelia risoria. This avian species has proved an excellent animal model for studies concerning endocrine‐behavior interactions for many years. Studies were performed to localize the expression of central androgen and progesterone receptor in both sexes. Expression of androgen receptor (androgen receptor immunoreactivity, AR‐ir) was widespread but increased, similarly in both sexes, with increasing day‐length. Progesterone receptor‐immunoreactivity (PR‐ir) was more localized in several discrete areas of the hypothalamus. Similarly, no sex differences were observed in PR‐ir, and expression increased in birds maintained on long days. AR‐ir demonstrated dramatic changes over the breeding cycle, being greatest in courting birds and almost undetectable in parenting birds of both sexes brooding their young. PR‐ir showed a differential expression over the breeding cycle relative to its hypothalamic localization. PR‐ir decreased in the tuberal hypothalamic area in brooding birds of both sexes; whereas in the preoptic area, PR‐ir was maintained. Significant increases in dopaminergic activity during the parenting phase of the breeding cycle occurred in specific neural regions including the PVM and DMA. Studies demonstrated the ability of the diencephalon of both sexes of the ring dove brain to synthesize progesterone, with indications that in the male brooding dove, synthesis is increased. Finally, a model is presented that proposes a mechanism whereby these central systems may interact to result in the expression of full parental behavior in both sexes of the ring dove. Microsc. Res. Tech. 55:12–26, 2001. © 2001 Wiley‐Liss, Inc.
Just in time and place: NOS/NO system assembly in neuromuscular junction formation
Authors: Blottner Dieter , Lück Gabriele
Published: August 2002

Recent advances in the molecular, biochemical, and anatomical aspects of postsynaptic membrane components at the neuromuscular junction (NMJ) are briefly reviewed focussing on assembly, architecture, and function of the multi‐subunit dystrophin‐protein complex (DPC) and its associated nitric oxide (NO)‐signaling complex. Elucidation of unique structural binding motifs of NO‐synthases (NOS), and microscopical codistribution of neuronal NOS (nNOS), the major isoform of NOS expressed at the NMJ, with known synaptic proteins, i.e., family members of the DPC, nicotinic acetylcholine receptor (AChR), NMDA‐receptor, type‐1 sodium andShakerK+‐channel proteins, and linker proteins (e.g., PSD‐95, 43K‐rapsyn), suggests targeting and assembly of the NO‐signaling pathway at postsynaptic membrane components. NO mediates agrin‐induced AChR‐aggregation and downstream signal transduction in C2 skeletal myotubes while administration of L‐arginine, the limiting substrate for NO‐biosynthesis, enhances aggregation of synapse‐specific components such as utrophin. At the NMJ, NO appears to be a mediator of (1) early synaptic protein clustering, (2) synaptic receptor activity and transmitter release, or (3) downstream signaling for transcriptional control. Multidisciplinary data obtained from cellular and molecular studies and from immunolocalization investigations have led us to propose a working model for step‐by‐step binding of nNOS, e.g., to subunit domains of targeted and/or preexisting membrane components. Formation of NOS‐membrane complexes appears to be governed by agrin‐signaling as well as by NO‐signaling, supporting the idea that parallel signaling pathways may account for the spatiotemporally defined postsynaptic assembly thereby linking the NOS/NO‐signaling cascade to early membrane aggregations and at the right places nearby preexisting targets (e.g., juxtaposition of NO source and target) in synapse formation. Microsc. Res. Tech. 55:171–180, 2001. © 2001 Wiley‐Liss, Inc.
Regeneration in echinoderm larvae
Authors: Vickery Michael C.L. , Vickery Minako S. , Amsler Charles D. , McClintock James B.
Published: August 2002

The ability of echinoderms to regenerate missing body parts has been a subject of interest to scientists for many years. Asexual reproduction (by fission or budding) is a phenomenon that involves regeneration of missing structures. Although asexual reproduction and regeneration have been the focus of many studies in adult echinoderms, there have been comparatively fewer studies examining these phenomena in echinoderm larvae, and most of these have been conducted in the last few years. In this article we review regeneration in larval echinoderms. We also discuss larval asexual reproduction. Microsc. Res. Tech. 55:464–473, 2001. © 2001 Wiley‐Liss, Inc.
Molecular approach to echinoderm regeneration
Authors: Thorndyke Michael C. , Chen Wei‐Chung , Beesley Philip W. , Patruno Marco
Published: August 2002

Until very recently echinoderm regeneration research and indeed echinoderm research in general has suffered because of the lack of critical mass. In terms of molecular studies of regeneration, echinoderms in particular have lagged behind other groups in this respect. This is in sharp contrast to the major advances achieved with molecular and genetic techniques in the study of embryonic development in echinoderms. The aim of our studies has been to identify genes involved in the process of regeneration and in particular neural regeneration in different echinoderm species. Our survey included the asteroidAsterias rubensand provided evidence for the expression ofHoxgene homologues in regenerating radial nerve cords. Present evidence suggests: 1)ArHox1expression is maintained in intact radial nerve cord and may be upregulated during regeneration. 2)ArHox1expression may contribute to the dedifferentiation and/or cell proliferation process during epimorphic regeneration. From the crinoidAntedon bifida, we have been successful in cloning a fragment of a BMP2/4 homologue (AnBMP2/4) and analysing its expression during arm regeneration. Here, we discuss the importance of this family of growth factors in several regulatory spheres, including maintaining the identity of pluripotent blastemal cells or as a classic skeletal morphogenic regulator. There is clearly substantial scope for future echinoderm research in the area of molecular biology and certain aspects are discussed in this review. Microsc. Res. Tech. 55:474–485, 2001. © 2001 Wiley‐Liss, Inc.
Presence of thyroid hormones in ascidian larvae and their involvement in metamorphosis
Authors: Patricolo Eleonora , Cammarata Matteo , D’Agati Paolo
Published: August 2002

In this study we investigated the presence and localization of thyroxine in Ciona intestinalis larvae and its involvement in metamorphosis. To date, the mechanisms regulating the metamorphosis of ascidians remain largely unknown. In vivo treatment of swimming larvae with exogenous L‐thyroxine and thiourea, and in vitro experiments utilizing high performance liquid chromatography, radioimmunoassay, and immunoperoxidase staining demonstrate the presence of thyroxine at the larval stage. This suggests that this hormone may participate in the control of metamorphosis and thus play a different role from that observed in adults. J. Exp. Zool. 290:426–430, 2001. © 2001 Wiley‐Liss, Inc.
Temporal control of DNA replication and the adaptive value of chromatin diminution in copepods
Authors: Wyngaard Grace A. , Gregory T. Ryan
Published: August 2002

Chromatin diminution is a precisely controlled, highly repeatable, genome‐wide deletion of noncoding heterochromatic segments from the presomatic line. The somatic line is reduced in size and reorganized; the germ line remains unaltered. Little is understood about its mechanistic underpinnings and adaptive significance in the nematodes, copepods, and hagfish in which it occurs. Here, we propose that microcrustacean copepods, whose cytology, development, and evolutionary ecology are well understood from an adaptationist point of view, provide the vehicle to test how chromatin diminution might orchestrate certain cell cycle dynamics, with the consequence of influencing the evolution of nuclear DNA contents, organismal development rates, and body size. J. Exp. Zool. (Mol. Dev. Evol.) 291:310–316, 2001. © 2001 Wiley‐Liss, Inc.
Sperm storage in turtles: A male perspective
Authors: Gist Daniel H. , Dawes Sue M. , Turner Terry W. , Sheldon Susannah , Congdon J. D.
Published: August 2002

The storage and behavior of sperm collected from the epididymis of two emyiid turtles were examined. In Chrysemys picta, the weight of the epididymis does not change significantly throughout the year as does the testis. However, in this species, as well as in Trachemys scripta, the epididymis contains sperm throughout the entire year. Sperm from both species have a relatively low motility and velocity of movement. In C. picta, equally low motilities are observed both in the autumn, shortly after spermiation, and in spring. Motility could be augmented by the addition of isobutyl methyl xanthine (IBMX, 0.5 mmol l–1). Epididymal sperm remained viable in excess of 40 days in vitro when stored in F‐10 buffer, during which time motility and swimming velocity could be augmented with IBMX. The longevity and low motility of turtle sperm facilitates its storage by either males or females, and creates conditions that promote the wide dissemination, over time, of gametes produced in a narrow time window. J. Exp. Zool. 292:180–186, 2002. © 2002 Wiley‐Liss, Inc.
Side‐effects of a systemic injection of linear polyethylenimine–DNA complexes
Authors: Chollet Patrice , Favrot Marie C. , Hurbin A. , Coll Jean‐Luc
Published: August 2002

Background

Systemic administration of linear polyethylenimine–DNA complexes (L‐PEI/DNA) results in transient expression of the transgene in the lung. This study analyzes the side‐effects associated with L‐PEI‐mediated transfection.

Methods

Mice weighing from 16 to 25 g received increasing amounts of L‐PEI/DNA intravenously. Gene expression was evaluated using luciferase as a reporter gene. Toxicity was evaluated by monitoring the appearance of shock after injection, the survival of the animals, and the microscopic damage in the tissues. Adherence of blood cells and endothelium activation were observed after CD11‐b and von Willebrand immunostaining. Anti‐aggregant treatments were used in order to prevent the formation of thrombi.

Results

Increasing the quantity of L‐PEI/DNA resulted in a marked augmentation of the luciferase activity in the lung, but was associated with liver necrosis and death. Lethality was reached at lower doses in older mice, suggesting an age influence. Transfection was associated with activation of the lung endothelium and increased adhesion of small aggregates containing platelets and CD11‐b‐positive cells, without the appearance of large thrombi and of lung injury. Anti‐aggregant treatments (aspirin, EDTA, heparin or clopidogrel) decreased the L‐PEI‐mediated transfection, supporting the hypothesis that platelets participate in the blocking of DNA complexes in the lung capillaries.

Conclusion

This study demonstrates that L‐PEI/DNA activates the lung endothelium and forms small aggregates, a side‐effect linked to the transfection efficiency. Copyright © 2001 John Wiley & Sons, Ltd.
Perceptions of poverty among poor livestock keepers in Kenya: a discourse analysis approach
Authors: Misturelli Federica , Heffernan Claire
Published: August 2002

The paper examines perceptions of poverty among poor livestock keepers in Kenya. The study utilized discourse analysis techniques to evaluate community values towards the poor. The results demonstrated that most study participants viewed poverty as a process rather than a permanent state. The findings also highlighted the differences between the rich and the poor in terms of capabilities. When the results were compared with a wealth ranking exercise, two types of bias were noted. First, wealth‐ranking exercises may not be targeting those who are the most needy. Second, projects and programmes may be viewed as assisting those who are responsible for their own poverty. Copyright © 2001 John Wiley & Sons, Ltd.
Radiosynthesis of (±)‐(2‐((4‐(2‐[18F]fluoro‐ethoxy)phenyl)bis(4‐methoxy‐phenyl)methoxy)ethylpiperidine‐3‐carboxylic acid: a potential GAT‐3 PET ligand to study GABAergic neuro‐transmission in vivo
Authors: Schirrmacher Ralf , Hamkens Wilhelm , Piel Markus , Schmitt Ulrich , Lüddens Hartmut , Hiemke Christoph , Rösch Frank
Published: August 2002

A dysfunction of GABAergic neurotransmission is related to diseases such as epilepsy, Huntington‐disease and Parkinson‐syndrome. A new 18F‐fluorine labelled GABA transporter ligand for the GABA‐transporter subtype GAT‐3 was developed which may allow the in vivo visualisation of GABAergic neurotransmission. The precursors ethyl (2‐(4‐hydroxyphenyl)bis(4‐methoxyphenyl)‐methoxy)ethyl)‐piperidine‐3‐carboxylate and ethyl(2‐((4‐(2‐tosylethoxy)phenyl)‐bis(4‐methoxyphenyl)‐methoxy) ethyl)‐piperidine3‐carboxylate were synthesised and labelled by the use of 2‐[18F]fluoroethyltosylate or [18F]fluoride. Subsequent cleavage of the ester moiety gave the final product (±)‐(2‐((4‐(2‐[18F]fluoroethoxy)phenyl)bis(4‐methoxy‐phenyl)methoxy)ethyl)piperidine‐3‐carboxylic acid in a decay corrected yield of 33–36%. Preliminary biodistribution kinetics were determined with BALB/c mice ex vivo for brain, liver, kidney, spleen, blood and bone. (2‐((4‐(2‐[18F]fluoroethoxy)‐phenyl)bis(4‐methoxyphenyl)methoxy)‐ethyl) piperidine‐3‐carboxylic acid showed a maximum brain uptake after 1 h p.i. of about 0.3% ID/g. Copyright © 2001 John Wiley & Sons, Ltd.
Carbon‐11 labelling of MADAM in two different positions: a highly selective PET radioligand for the serotonin transporter
Authors: Tarkiainen Jari , Vercouillie Johnny , Emond Patrick , Sandell Johan , hiltunen Jukka , Frangin Yves , Guilloteau Denis , Halldin Christer
Published: August 2002

Imaging by scintigraphy the serotonin transporter (5‐HTT) in the living human brain would be of great value in research on the pathophysiology and treatment of neuropsychiatric disorders such as depression. For that reason, and in order to obtain a selective radiotracer applicable to PET, we report here the carbon‐11 labelling of a selective 5‐HTT radioligand: N, N‐dimethyl‐2‐(2‐amino‐4‐methylphenylthio)benzylamine or MADAM in two different positions: [p‐11C‐methyl]MADAM and [N‐11C‐methyl]MADAM. The synthesis of Bu3Sn‐ADAM and N‐dimethyl‐MADAM is described. [p‐11C‐methyl]MADAM was obtained by a Stille coupling reaction between Bu3Sn‐ADAM and [11C]methyl iodide using palladium (0) as a catalyst without (Ia) or with copper chloride as a co‐catalyst (Ib). [N‐11C‐methyl]MADAM was obtained by an N‐methylation reaction between N‐demethyl‐MADAM and [11C]methyl iodide (II). The carbon‐11 incorporation yield in [p‐11C‐methyl]MADAM was 10–30% (Ia and Ib) and in [N‐11C‐methyl]MADAM was 75‐80% (II). The final product in each case was obtained in 30 min total synthesis time, including HPLC purification and with >99% radiochemical purity. Copyright © 2001 John Wiley & Sons, Ltd.
The endocrine cells in the gastroenteropancreatic system of the bowfin, Amia calva L.: An immunohistochemical, ultrastructural, and immunocytochemical analysis
Authors: Youson John H. , Al‐Mahrouki Azza A. , Naumovski Diana , Conlon J. Michael
Published: August 2002

The gastroenteropancreatic (GEP) endocrine system of bowfin (Amia calva) was described using light and electron microscopy and immunological methods. The islet organ (endocrine pancreas) consists of diffusely scattered, mostly small islets and isolated patches of cells among and within the exocrine acini. The islets are composed of abundant, centrally located B cells immunoreactive to bovine and lamprey insulin antisera and D cells showing a widespread distribution and specificity to somatostatin antibodies. A and F cells are present at the very periphery of the islets and are immunoreactive with antisera against glucagon (and glucagon‐like peptide) and several peptides of the pancreatic polypeptide (PP)‐family, respectively. The peptides of the two families usually collocates within the same peripheral islet cells and are the most common immunoreactive peptides present in the extra‐islet tissue. Immunocytochemistry and fine structural observations characterised the granule morphology for B and D cells and identified two cell types with granules immunoreactive to glucagon antisera. These two putative A cells had similar granules, which were distinct from either B or D cells, but one of the cells had rod‐shaped cytoplasmic inclusions within cisternae of what appeared to be rough endoplasmic reticulum. The inclusions were not immunoreactive to either insulin or glucagon antisera. Only small numbers of cells in the stomach and intestine immunoreacted to antisera against somatostatin, glucagon, and PP‐family peptides. The paucity of these cells was reflected in the low concentrations of these peptides in intestinal extracts. The GEP system of bowfin is not unlike that of other actinopterygian fishes, but there are some marked differences that may reflect the antiquity of this system and/or may be a consequence of the ontogeny of this system in this species. J. Morphol. 250:208–224, 2001. © 2001 Wiley‐Liss, Inc.
Head structures ofPriacma serrataleconte (coleptera, archostemata) inferred from X‐ray tomography
Authors: Hörnschemeyer Thomas , Beutel Rolf G. , Pasop Freek
Published: August 2002

Internal and external features of the head ofPriacma serratawere studied with X‐ray microtomography and with histological methods. The comparison of both techniques shows that X‐ray tomography is a promising new technique for the investigation of insect anatomy. The still somewhat coarse resolution of the X‐ray data is compensated for by advantages like the nondestructive and artifact‐free data acquisition. The head ofP. serrataand other adults of Archostemata is characterized by many derived features. Muscular features ofPriacma, especially muscles of the labium and pharynx, differ strongly from what is found in other groups of Coleoptera. Several character states are considered as autapomorphies of Archostemata: scale‐like surface structures, constricted neck, strongly reduced tentorium, and the plate‐like, enlarged prementum. The scales provide a protecting surface pattern and may have evolved with a more exposed lifestyle. The enlarged prementum forms a lid, which closes the mouth and covers the ligula when it is pulled back by contraction of the unusually strong submento‐premental muscle. The presence of four cone‐shaped protuberances on the dorsal side of the head is considered an autapomorphy of Cupedidae. The galea with a narrow stalk and a round and pubescent distal galeomere is another autapomorphy of this family. It has probably evolved as an adaptation to pollen‐feeding. The shape of the mandible of Cupedidae is plesiomorphic compared to what is found in adults of Ommatidae. The vertical arrangement of apical teeth is an autapomorphy of the latter family. The lateral insertion of the antenna inPriacmais a groundplan feature of Cupedidae. The dorsal shift is a synapomorphy of all other cupedid genera. A cladistic analysis of characters of the head and additional data resulted in the following branching pattern: ((Crowsoniella + (Omma + Tetraphalerus)) + (Micromalthus + (Priacma + (Paracupes + (Cupes + Tenomerga + Prolixocupes + Rhipsideigma + Distocupes + (Adinolepis + Ascioplaga)))))). J. Morphol. 252:298–314, 2002. © 2002 Wiley‐Liss, Inc.
FAST sequences optimization for contrast media pharmacokinetic quantification in tissue
Authors: Ivancevic Marko K. , Zimine Ivan , Lazeyras François , Foxall David , Vallée Jean‐Paul
Published: August 2002

The purpose of this study was to investigate the influence of the fast gradient‐recalled echo (GRE) sequence parameters on the contrast dynamic range and signal sensitivity, to optimize the magnetic resonance (MR) sequence for contrast media pharmacokinetic assessment. Effects of the fast low‐angle shot (FLASH), Fast acquisition at steady rate (FAST), and radiofrequency‐spoiled (RF)‐FAST sequence parameters were studied in vitro. The FAST sequence had the highest sensitivity in low gadolinium (Gd) concentration. The FLASH and RF‐FAST sequences had a larger contrast dynamic range, but the FLASH images contained side band artifacts. Increasing the flip angle to 90° raised the sensitivity of the FAST sequence and the contrast dynamic range of the RF‐FAST sequence. The shortest possible TE was optimal for both contrast dynamics and imaging time. TI had an influence on the sensitivity of the FAST sequence only for small acquisition matrices. This study indicates the optimal parameters for contrast dynamics (RF‐FAST, 90° flip angle, shortest possible TE) and sensitivity (FAST, 90° flip angle, long TIeff). J. Magn. Reson. Imaging 2001;14:771–778. © 2001 Wiley‐Liss, Inc.
Perfusion abnormalities in pulmonary embolism studied with perfusion MRI and ventilation‐perfusion scintigraphy: An intra‐modality and inter‐modality agreement study
Authors: Amundsen Tore , Torheim Geir , Kvistad Kjell A. , Waage Anders , Bjermer Leif , Nordlid Knut K. , Johnsen Harald , Åsberg Arne , Haraldseth Olav
Published: August 2002

Purpose

To compare perfusion magnetic resonance imaging (MRI) and ventilation‐perfusion scintigraphy (V‐P scan) in the study of perfusion abnormalities in pulmonary embolism (PE) and to compare the PE results to the findings previously reported for pneumonia and chronic obstructive pulmonary disease (COPD), in terms of perfusion abnormalities.

Materials and Methods

Dynamic contrast‐enhanced MR images and V‐P scans of 20 patients with PE, 11 patients with acute pneumonia, and 13 patients with exacerbation of COPD were studied. Five categories of perfusion abnormalities within each imaging modality were defined. Intra‐ and inter‐modality agreement (kappa values) in the evaluation of perfusion abnormalities were calculated, based on the two observers of each imaging modality (all blinded to each other and true diagnosis). Finally, three categories of perfusion MRI diagnosis (PE, pneumonia, and COPD) were also defined and the inter‐observer agreement (kappa value) was calculated.

Results

For PE, the intra‐modality agreement (kappa value) in the evaluation of perfusion abnormalities was 0.77 for MRI and 0.65 for V‐P scan. The inter‐modality agreement varied from 0.52 to 0.57, respectively, and was observer‐dependent. For the pooled group of PE, pneumonia, and COPD, the intra‐modality agreement of perfusion abnormalities was 0.76 for MRI and 0.65 for V‐P scan, and the inter‐modality agreement varied from 0.51 to 0.56. The kappa value for inter‐observer agreement for MRI diagnosis was 0.92.

Conclusion

Evaluation of perfusion abnormalities in PE, pneumonia, and COPD using perfusion MRI and V‐P scan showed a high intra‐modality agreement that was higher than the inter‐modality agreement. Further studies are now needed in patients presenting with possible PE to evaluate the sensitivity and specificity of the method. J. Magn. Reson. Imaging 2002;15:386–394. © 2002 Wiley‐Liss, Inc.
The effects of 1.5T magnetic resonance imaging on early murine in‐vitro embryo development
Authors: Chew Stephen , Ahmadi Ali , Goh P.S. , Foong L.C.
Published: August 2002

Although no ionizing radiation is involved, patients undergoing magnetic resonance imaging (MRI) are exposed to powerful static magnetic fields, magnetic field gradients, and radio‐frequency fields that may be potentially damaging. Our study aims to document the effect of MRI imaging sequences on early murine embryo development (two‐cell to blastocyst stage) in vitro. Two‐cell murine embryos were exposed to various lengths of MRI using pulse sequences employed in present day clinical imaging. Early murine embryo development was documented in vitro, and blastocyst development rates were computed for both the control and exposed groups. There were no significant differences detected in the rate of blastocyst formation between the control groups and the embryos exposed to MRI. J. Magn. Reson. Imaging 2001;13:417–420. © 2001 Wiley‐Liss, Inc.
Freehand iMRI‐guided large‐gauge core needle biopsy: A new minimally invasive technique for diagnosis of enhancing breast lesions
Authors: Daniel Bruce L. , Birdwell Robyn L. , Butts Kim , Nowels Kent W. , Ikeda Debra M. , Heiss Steven G. , Cooper Claudia R. , Jeffrey Stefanie S. , Dirbas Frederick M. , Herfkens Robert J.
Published: August 2002

The lack of reliable methods for minimally invasive biopsy of suspicious enhancing breast lesions has hindered the utilization of contrast‐enhanced magnetic resonance imaging (MRI) for the detection and diagnosis of breast cancer. In this study, a freehand method was developed for large‐gauge core needle biopsy (LCNB) guided by intraprocedural MRI (iMRI). Twenty‐seven lesions in nineteen patients were biopsied using iMRI‐guided LCNB without significant complications. Diagnostic tissue was obtained in all cases. Nineteen of the 27 lesions were subsequently surgically excised. Histopathologic analysis confirmed that iMRI‐guided LCNB correctly distinguished benign lesions from malignancy in 18 of the 19 lesions. The histology revealed by core biopsy was partially discrepant with surgical biopsy in 2 of the other 19 lesions. Freehand iMRI‐guided LCNB of enhancing breast lesions is promising. Larger studies are needed to determine the smallest lesion that can be sampled reliably and to precisely measure the accuracy of iMRI‐guided LCNB as a minimally invasive tool to diagnose suspicious lesions found by breast MRI. J. Magn. Reson. Imaging 2001;13:896–902. © 2001 Wiley‐Liss, Inc.
Time course of arterial hyperintensity with fast fluid‐attenuated inversion‐recovery imaging in acute and subacute middle cerebral arterial infarction
Authors: Maeda Masayuki , Koshimoto Yoshio , Uematsu Hidemasa , Yamada Hiroki , Kimura Hirohiko , Kawamura Yasutaka , Itoh Harumi , Sakuma Hajime , Takeda Kan
Published: August 2002

The purpose of this study was to evaluate the time course of arterial hyperintensity (AH) in acute and subacute cerebral infarctions of the middle cerebral artery (MCA) distribution by using fast fluid‐attenuated inversion‐recovery (FLAIR) imaging. A total of 40 FLAIR MR examinations were performed in 27 patients with MCA infarction within 13 days after ictus. Thirteen patients underwent two MR examinations during this period. Thrombotic or embolic infarctions were included in this study, but lacunar infarctions were excluded. The presence or absence of AH and the location of AH were analyzed. Overall, AH was found in 24 (60%) of 40 FLAIR examinations within 13 days after onset. AH was seen in 17 (100%) examinations less than 24 hours old, four (40%) of 10 examinations 1–4 days old, two (18%) of 11 examinations 5–9 days old, and one (50%) of two examinations 10–13 days old. AH was most frequently found at the sylvian fissure (87%), followed by the sulci (54%), and the horizontal segment of MCA (29%) in the affected MCA distribution. Although AH could be seen even at 13 days after ictus, the presence of AH declined over time. AH represented an early sign of acute embolic or thrombotic infarction. J. Magn. Reson. Imaging 2001;13:987–990. © 2001 Wiley‐Liss, Inc.
Oblique sagittal view of the anterior cruciate ligament: Comparison of coronal vs. axial planes as localizing sequences
Authors: Barberie John E. , Carson Brent W. , Finnegan Martin , Wong Anthony D.
Published: August 2002

The purpose of this study was to determine whether oblique sagittal T2‐weighted images of the anterior cruciate ligament (ACL) are better prescribed off axial or coronal localizing images. Thirty‐one patients underwent two sets of oblique sagittal T2‐weighted fast spin‐echo sequences to evaluate the ACL. One oblique was prescribed from a coronal localizing sequence, while the other was prescribed off an axial series. Objective (average number of images to demonstrate ACL) and subjective (radiologist's confidence level) evaluations of both sequences were performed independently of the other and then comparatively by two radiologists. The coronally prescribed sagittal oblique was subjectively preferred in 18 patients, the axially prescribed oblique was preferred in one patient, and both sequences were felt to be equivalent in 12 patients. In 13 intact ligaments, the average number of images clearly demonstrating the entire length of the ACL was 1.77 on the coronally prescribed sequence and 1.31 on the axially prescribed images. Oblique sagittal images prescribed off a coronal localizer are both subjectively and objectively more effective than axially prescribed sagittal obliques in evaluating the ACL. J. Magn. Reson. Imaging 2001;14:203–206. © 2001 Wiley‐Liss, Inc.
MRI of carcinoid tumors: Spectrum of appearances in the gastrointestinal tract and liver
Authors: Bader Till R. , Semelka Richard C. , Chiu Vivian C.Y. , Armao Diane M. , Woosley John T.
Published: August 2002

The purpose of this study was to evaluate the spectrum of appearances of gastrointestinal carcinoid tumors at magnetic resonance imaging (MRI) and to elucidate patterns of appearances of carcinoid liver metastases on precontrast and postgadolinium images. The MR examinations of 29 patients (11 men, 18 women; age range, 33–87 years) with histologically confirmed gastrointestinal carcinoid tumors, representing our complete 9.5 years of experience with this entity, were retrospectively reviewed. Twelve patients had MR examinations prior to resection or biopsy of the primary tumor (preoperative group); 17 patients were imaged postsurgically (postoperative group). All MR studies were performed at 1.5 T and comprised T1‐weighted spoiled gradient echo (SGE), T2‐weighted fat‐suppressed turbo spin echo, HASTE, and serial postgadolinium T1‐weighted SGE sequences without and with fat suppression. Morphology, signal intensity, and contrast enhancement of primary tumors and of metastases to the mesentery, peritoneum, and liver were evaluated. Primary tumors were visualized in 8 of 12 patients and best demonstrated on postgadolinium T1‐weighted fat‐suppressed images. The appearance of primary tumors was a nodular mass originating from the bowel wall (4 of 12 patients) or regional uniform bowel wall thickening (4 of 12 patients) with moderate intense enhancement on postgadolinium images. In 4 of 12 patients the primary tumor was prospectively not seen. Mesenteric metastases, seen in eight patients, presented as nodular masses and were associated with mesenteric stranding in seven patients. A total of 156 liver metastases were evaluated in 16 patients. On precontrast T1‐ and T2‐weighted images, 117 metastases (75%) were hypointense and hyperintense, respectively. A total of 146 metastases (94%) were hypervascular, showing moderate intense enhancement during the hepatic arterial phase, and 9 metastases (6%) were hypovascular. Twenty‐three metastases (15%) were visible only on immediate postgadolinium images. MRI is able to demonstrate findings in carcinoid tumors, including the primary tumor, mesenteric metastases, and liver metastases. Liver metastases are commonly hypervascular and may be demonstrable only on immediate postgadolinium images. J. Magn. Reson. Imaging 2001;14:261–269. © 2001 Wiley‐Liss, Inc.