bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibrillar collagen: The key to vertebrate evolution? A tale of molecular incest
Authors: Boot‐Handford Raymond P. , Tuckwell Danny S. 
Published: January 2003

AbstractFibril‐forming (fibrillar) collagens are extracellular matrix proteins conserved in all multicellular animals. Vertebrate members of the fibrillar collagen family are essential for the formation of bone and teeth, tissues that characterise vertebrates. The potential role played by fibrillar collagens in vertebrate evolution has not been considered previously largely because the family has been around since the sponge and it was unclear precisely how and when those particular members now found in vertebrates first arose. We present evidence that the classical vertebrate fibrillar collagens share a single common ancestor that arose at the very dawn of the vertebrate world and prior to the associated genome duplication events. Furthermore, we present a model, ‘molecular incest’, that not only accounts for the characteristics of the modern day vertebrate fibrillar collagen family but demonstrates the specific effects genome or gene duplications may have on the evolution of multimeric proteins in general. BioEssays 25:142–151, 2003. © 2003 Wiley Periodicals, Inc.
Cancer therapy: switching off oncogenes
Authors: Pompetti Franca , Pilla Daniela , Giancola Raffaella 
Published: January 2003

AbstractCancer derives from a cell clone that has accumulated genetic and epigenetic changes that influence its phenotype and finally enable it to escape from the normal controls of proliferation. A recent paper shows that, in myc‐induced tumours, the inactivation of this oncogene produces the regression of the tumours and the differentiation of the tumour cells into mature osteocytes.1 In addition, a further reactivation of myc in these cells does not restore the malignant phenotype but induces apoptosis. This discovery could lead to an innovative therapeutic strategy. BioEssays 25:104–107, 2003. © 2003 Wiley Periodicals, Inc.
Recent developments in toroid cavity autoclave engineering
Authors: Niessen Heiko G. , Trautner Peter , Backhausen Rolf , Woelk Klaus 
Published: January 2003

AbstractA toroid cavity autoclave (TCA) is a metal pressure vessel that simultaneously functions as an NMR resonator. Since the introduction of the TCA concept, many adaptations and optimizations were put together to suit particular applications such as catalysis in supercritical fluids, rotating‐frame imaging of materials, and evaluation of transport phenomena. In this article, we present recent achievements in TCA engineering that were carried out for both major fields of research with TCAs, i.e., high‐pressure and imaging studies. A new modular TCA design is introduced that makes it possible to easily access all individual parts of the autoclave for maintenance and replacement. The TCA is double tuned to a high frequency for 1H and 19F resonances and a low frequency for hetero nuclei. It withstands pressures up to 400 bar at room temperature and 300 bar at temperatures up to 100°C. The autoclave sample volume is electrically separated into two compartments with only the lower compartment NMR sensitive. With the two‐compartment TCA, it is possible to monitor multiple‐phase systems or gas/liquid reactions in situ without sacrificing high‐resolution qualities of the probe. In addition, special features are presented, such as the utilization of a second pressure line for injecting key reagents that initiate a chemical reaction or for vigorously mixing gases with a reactive solution. A newly designed resistive heater that does not introduce stray magnetic fields is also described. © 2003 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 16B: 15–21, 2003
Multilayer transverse gradient coil design
Authors: Leggett J. , Crozier S. , Blackband S. , Beck B. , Bowtell R.W. 
Published: January 2003

AbstractIn small, cylindrical gradient coils consisting of a single layer of wires, the limiting factor in achieving large magnetic field gradients is the rapid increase in coil resistance with efficiency. This behavior results from the decrease in the maximum usable wire diameter as the number of turns is increased. By adopting a multilayer design in which the coil wires are allowed to spread out into multiple layers wound at increasing radii, a more favorable scaling of resistance with efficiency is achieved, thus allowing the design of more powerful gradient coils with acceptable resistance values. By extending the theory used to design standard cylindrical gradient coils, mathematical expressions have been developed that allow the design of multilayer coils. These expressions have previously been applied to the design of a four‐layer z‐gradient coil. As a further development, the equations have now been modified to allow the design of multilayer transverse gradient coils. The variation in coil performance with the number of layers employed has been investigated for coils of a size suitable for use in NMR microscopy, and the effect of constructing the coil using wires or cuts in a continuous conducting surface has also been assessed. We find that at fixed resistance a small wire‐wound two‐layer coil offers an increase in efficiency of a factor of about 1.5 compared with a single‐layer coil. In addition, a two‐layer coil of 10‐mm inner diameter has been designed and built. This coil had an efficiency of 0.41 Tm−1 A−1, a resistance of 0.96 ± 0.01 Ω, and an inductance of 22.3 ± 0.2 μH. The coil produces a gradient that deviates from linearity by less than 5% over a central cylindrical region of interest of height and length 6.2 mm. © 2003 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 16: 38–46, 2003.
Networks and history
Authors: Bearman Peter , Moody James , Faris Robert 
Published: January 2003

AbstractEvents and event structures compose the constituent elements of history. In order to construct historical accounts of event sequences, historians have to make cases. This article proposes a method for casing historical events. We illustrate the analytic strategy by considering a complex population of interrelated events that make up a narrative of revolution, counter revolution, and revolution in a small village in China. Implications for the methodology of historical social science are discussed. © 2003 Wiley Periodicals, Inc.
Sonographic detection of a malpositioned feeding tube causing esophageal perforation in a neonate
Authors: Maruyama Kenichi , Shiojima Takeshi , Koizumi Takenobu 
Published: January 2003

AbstractWe report a case of esophageal perforation caused by a malpositioned feeding tube in a neonate of extremely low birth weight, 632 g. The infant had respiratory distress, which increased rapidly when he was 6 days old. Radiography revealed right‐sided hydrothorax that had not been evident a day earlier but no sign of a perforated esophagus. We performed sonography, which revealed fluid in the right pleural cavity and extra‐esophageal placement of the feeding tube. Analysis of a fluid specimen obtained on thoracocentesis indicated that the fluid was feeding formula. The feeding tube's misplacement was confirmed sonographically by injecting a small amount of sterile distilled water into the tube and visualizing its entry into the pleural cavity. The feeding tube was removed, and antimicrobial agents were administered. When the infant was 15 days old, feeding resumed through another tube, the placement of which was verified radiographically. The infant was discharged when he was 118 days old with no severe complications, although he had mild chronic lung disease. Because radiography did not reveal the tube's misplacement in this case, we believe that the use of sonography can contribute to an early diagnosis of esophageal perforation in such cases. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:108–110, 2003
Sonographic measurements of normal gallbladder sizes in children
Authors: Yoo Jeong‐Hyun , Kwak Hyun‐Joo , Lee Myung‐Jun , Suh Jeong‐Soo , Rhee Chung‐Sik 
Published: January 2003

AbstractPurposeOur goal was to establish the range of sonographic measurements of normal gallbladders in children.MethodsSix hundred ten children aged 0–16 years (male:female ratio, 1.5:1) with normal clinical and laboratory findings were included in this study. The sonographic parameters were the length, width, and calculated volume of the gallbladder, and the clinical parameters were the age, height, weight, and body surface area of the children. Statistical significance was determined through correlation and regression analyses.ResultsThe length of the gallbladder showed significant positive correlations with age (r = 0.65), height (r = 0.67), weight (r = 0.63), and body surface area (r = 0.65; p < 0.01). The calculated volume of the gallbladder also showed moderate correlations with age (r = 0.53), height (r = 0.55), weight (r = 0.61), and body surface area (r = 0.57; p < 0.01). The gallbladder width showed modest but significant correlations with age (r = 0.48), height (r = 0.53), weight (r = 0.53), and body surface area (r = 0.55; p < 0.01). The highest correlation coefficients were found between the gallbladder length and subject age (r = 0.65; p < 0.01) and between the gallbladder length and subject height (r = 0.67; p < 0.01). For all correlations, statistical significance remained after regression analysis (p < 0.01).ConclusionsValues for the size of the normal pediatric gallbladder are defined and will be helpful in the diagnosis of gallbladder abnormalities. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:80–84, 2003
Lymphangiogenesis in tumors: What do we know?
Authors: Reis‐Filho Jorge Sergio , Schmitt Fernando C. 
Published: January 2003

AbstractLymphangiogenesis, the growth of new lymphatic vessels, has long been regarded as a putative efficient pathway to neoplastic metastization. However, until recently consistent data regarding reliable lymphatic endothelial cell markers were lacking. Moreover, the presence of new formed lymphatic vessels was considered a largely disputable concept. Now, this scenario has changed significantly, owing to consistent reports describing novel lymphatic endothelial cell (LEC) markers, the demonstration of new formed lymphatic vessels within the bulk of the tumor in animal models and human neoplasms, and the characterization of the VEGF‐C/VEGFR‐3 pathway. We herein review the major breakthroughs in the field of lymphangiogenesis, with special emphasis on novel and reliable LEC markers, such as prox‐1, LYVE‐1, and podoplanin, as well as on the pathological assessment of lymphangiogenesis as a putative prognostic factor for human neoplasms. Microsc. Res. Tech. 60:171–180, 2003. © 2003 Wiley‐Liss, Inc.
Angiogenesis in endocrine glands: Special reference to the expression of vascular endothelial growth factor
Authors: Katoh Ryohei 
Published: January 2003

AbstractRecent studies have shown that several angiogenic growth factors are produced and secreted by normal endocrine cells and are increased in pathological states of endocrine glands, including inflammation, hyperplasia, and neoplasia. Expression of corresponding receptors on epithelial cells and/or endothelial cells enables these angiogenic factors to influence growth and function of the endocrine tissues by auto‐ or paracrine mechanisms. Some of the angiogenic factors are also considered to be involved in angiogenesis, which is a critical process in tumor formation and progression. Vascular endothelial growth factor (VEGF) is regarded as one of most important angiogenic factors with specific effects on endothelial cell growth and vascular permeability, and is isolated from a variety of normal and neoplastic endocrine cells. In this article, recent studies on angiogenic factors, especially on expression of VEGF, are reviewed in the field of endocrine systems. Microsc. Res. Tech. 60:181–185, 2003. © 2003 Wiley‐Liss, Inc.
Vascular networks and endothelial cells in the rat experimental pituitary glands and in the human pituitary adenomas
Authors: Itoh Johbu , Serizawa Akihiko , Kawai Kenji , Ishii Yudo , Teramoto Akira , Osamura Robert Yoshiyuki 
Published: January 2003

AbstractThere has been considerable interest in the relationship between hormone‐secreting endocrine cells (HSEC) and their microvessels (MVN) in human pituitary gland. However, microcirculatory networks have rarely been studied in three dimensions (3D). Therefore, this study was designed to visualize and to reveal the relationship between hormone secreting endocrine cells and their microvessel environment including vascular endothelial cells in 3D using rat pituitary glands under various experimental conditions by confocal laser scanning microscopy (CLSM). By CLSM, the 3D distributions of MVN were visualized and revealed a relationship between HSEC and MVN in experimental pituitary glands and human pituitary adenomas. Therefore, 3D reconstructed imaging by CLSM is a useful technique with which to investigate the microvessel environment of hormone‐secreting cells and has the potential to reveal dynamic hormone‐secreting pathways. Microsc. Res. Tech. 60:231–235, 2003. © 2003 Wiley‐Liss, Inc.
Angiogenesis in pituitary adenomas
Authors: Yamada Shozo , Takada Kouji 
Published: January 2003

AbstractAngiogenesis, which is the formation of new blood vessels from preexisting capillaries, plays an important role in tumor growth and metastasis. In this review, the focus is on angiogenesis in pituitary adenomas. Angiogenesis of pituitary adenomas has been assessed by studying tumor microvessel density using specific immunohistochemical markers to clarify the relationship between angiogenesis and tumor behavior. Unlike other organs, pituitary adenomas have significantly lower vascular densities as compared to nontumorous adenohypophysis, suggesting that the lack of significant angiogenesis may play a role in the slow pace of pituitary tumor growth and rarity of metastases. In addition, the relationship between microvessel density and various factors in pituitary adenomas is reviewed, including tumor types, age and sex, invasiveness, malignancy, several proliferative markers (MIB‐1 or Ki‐67). However, further studies will be needed, since many studies have reached opposite conclusions. Angiogenesis is a complex multistep process and several factors are found to be involved in each step of neovascularization, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and various other cytokines. VEGF and bFGF (or FGF‐2), which are the most potent angiogenesis inducers among them, have been studied by immunohistochemistry, in situ hybridization, or in vitro studies in normal or adenomatous pituitaries and these results are also discussed in this review. Microsc. Res. Tech. 60:236–243, 2003. © 2003 Wiley‐Liss, Inc.
Angiogenesis in normal and neoplastic pituitary tissues
Authors: Lloyd Ricardo V. , Vidal Sergio , Horvath Eva , Kovacs Kalman , Scheithauer Bernd 
Published: January 2003

AbstractAngiogenesis, or the formation of new blood vessels, is a dynamic process needed for embryogenesis, post‐natal growth, morphogenesis, tumorigenesis, and for other biological processes. Angiogenesis is very important for tumor development and progression. This review examines the activators and inhibitors of angiogenesis with emphasis on the pituitary gland and pituitary neoplasms. Some of the proteins regulating angiogenesis in pituitary tumors such as vascular endothelial growth factor (VEGF) and VEGF receptors, fibroblasts growth factors (FGF), transforming growth factor beta (TGFB), interleukins, interferons, and matrix metalloproteinases (MMPs) and inhibitors of MMPs have been examined in animal and human pituitary tumor models. However, many other significant regulators of angiogenesis including angiopoietins, angiostatin, and thrombospondins have not been studied extensively in pituitary tumors to date. Newer concepts and developments in angiogenesis such as vasculogenic mimicry and gene therapy approaches to angiogenesis in cancer treatment are also discussed. Microsc. Res. Tech. 60:244–250, 2003. © 2003 Wiley‐Liss, Inc.
Development, growth, and plasticity in the crayfish olfactory system
Authors: Sandeman Renate , Sandeman David 
Published: January 2003

AbstractDecapod crustaceans have a well‐defined olfactory system characterised by a set of chemosensitive sensilla grouped together in an array (the olfactory organ) on their antennules. Olfactory receptor neurons in the olfactory organ project exclusively to, and terminate in, cone‐shaped olfactory glomeruli in a discrete neuropil in the brain, the olfactory lobe. The olfactory organ appears to be the only afferent input to the olfactory lobe, making the system convenient for the study of its development and growth. The progression of development of the olfactory system is a continuum and can be traced from the first appearance of peripheral receptor cells and central stem cells through to the construction of the tracts and neuropils that constitute the adult system. Cell proliferation leading to the production of peripheral and central olfactory neurons can be observed with mitotic markers in both embryonic stages and in postembryonic growth. Cell proliferation in the olfactory system in crayfish persists throughout the lives of the animals and can be modulated by manipulating the living conditions imposed on growing animals. Large serotonergic neurons that are associated with the olfactory system may play a role in the regulation of cell proliferation. Microsc. Res. Tech. 60:266–277, 2003. © 2003 Wiley‐Liss, Inc.
Active dendritic properties constrain input‐output relationships in neurons of the central olfactory pathway in the crayfish forebrain
Authors: Mellon Deforest 
Published: January 2003

AbstractParasol cells are multimodal sensory interneurons of the hemi‐ellipsoid body in the decapod forebrain. In reptant crustaceans, the hemi‐ellipsoid body resides in the base of the eyecup, as an appendage to the terminal medulla. Parasol cells exhibit periodic depolarizations at a frequency of 0.5–1.0 Hz.. I have investigated the role of these periodic depolarizations and their superimposed impulse bursts in affecting the input/output properties of these neurons. Parasol cells receive input from photic, olfactory, and mechanosensory pathways. Strong stimulation over any one of these pathways can lead to the generation of one or more impulse bursts in a subset of parasol cells, timed to occur at the peak of successive periodic depolarizations. A role for the periodic depolarizations in the function of the parasol cells has yet to be established. I suggest the possibility that they may act as a nonlinear amplifier that boosts spatially‐summated excitatory synaptic potentials from strong or appropriate stimuli above threshold for burst generation. Another possibility includes modification of voltage‐sensitive ion channels in the dendritic membrane, permitting a more effective spread of excitatory synaptic currents to impulse or burst initiating zones. Impulse bursts may be a highly effective mode of output for these neurons, especially so as they occur synchronously in a subset of cells in response to strong sensory input. Furthermore, backfiring of bursts into the dendritic tree has a brief (2–3 second) but effective suppressive action upon weak sensory input, which can thereby be masked by stronger, burst‐generating input. This masking phenomenon is seen in other arthropod sensory interneurons, where its physiological basis appears to be a transient accumulation of intracellular Ca++ ions that open calcium‐sensitive potassium channels. Microsc. Res. Tech. 60:278–290, 2003. © 2003 Wiley‐Liss, Inc.
The circadian system of crayfish: A developmental approach
Authors: Fanjul‐Moles María Luisa , Prieto‐Sagredo Julio 
Published: January 2003

AbstractAdult crayfish exhibit a variety of overt circadian rhythms. However, the physiological mechanisms underlying the overt rhythms are controversial. Research has centered on two overt rhythms: the motor activity and the retinal sensitivity rhythms of the genus Procambarus. The present work reviews various studies undertaken to localize pacemakers and mechanisms of entrainment responsible for these two rhythms in adult organisms of this crustacean decapod. It also describes an ontogenetic approach to the problem by means of behavioral, electrophysiological, and neurochemical experiments. The results of this approach confirm previous models proposed for adult crayfish, based on a number of circadian pacemakers distributed in the central nervous system. However, the coupling of rhythmicity between these independent oscillators might be complex and dependent on the interaction between serotonin (5‐HT), light, and the crustacean hyperglycemic hormone (CHH). The latter compound has, up until now, not been considered as an agent in the genesis and synchronization of the retinal sensitivity rhythm. Microsc. Res. Tech. 60:291–301, 2003. © 2003 Wiley‐Liss, Inc.
Neuropeptides in the crayfish stomatogastric nervous system
Authors: Skiebe Petra 
Published: January 2003

AbstractNeuropeptides are peptides with profound effects on the nervous system. The function of neuropeptides can be studied in detail in the stomatogastric nervous system (STNS). Neuropeptides are ubiquitously distributed in the STNS and it contains well‐studied neural circuits that are strongly modulated by neuropeptides. The STNS controls the movements of the foregut in crustaceans and has been studied intensively in a variety of decapod crustaceans including crayfish. This article reviews our knowledge of neuropeptides in the crayfish STNS. Within crayfish, peptides reach the circuits of the STNS as neurohormones released by neurohaemal organs or by putative neurohemal zones located within the STNS. As transmitters, neuropeptides are present in identified motoneurons, interneurons, and sensory neurons (mainly shown by immunocytochemistry), indicating a multiple role of peptides in the plasticity of neural networks. Neuropeptides are not only present in varicosities within the neuropil of ganglia, but also in varicosities on muscles and within small neuropil patches along nerves. This suggests that the muscles of the stomach are under a more direct modulatory control than previously thought, and that information processing can also occur within nerves. In addition to anatomical studies, biochemical and electrophysiological methods were used. For example, MALDI‐TOF MS (matrix‐assisted laser desorption ionization time of flight mass spectrometry) revealed the presence of four different peptides of the orcokinin family within a single neuron, and electrophysiological experiments demonstrated that the networks of the STNS are not only under excitatory but also inhibitory peptidergic influence. Comparing the similarities and differences between the STNS of crayfish and that of other decapod crustaceans has already contributed to our knowledge about peptides and will further help to unravel peptide function in the plasticity of neural circuits. For example, the identified neurons in the STNS can be used to study co‐transmission because neuropeptides are co‐localized with classical transmitters, biogenic amines, or other peptides in these neurons. Microsc. Res. Tech. 60:302–312, 2003. © 2003 Wiley‐Liss, Inc.
Physiological functions of FMRFamide‐like peptides (FLPs) in crustaceans
Authors: Mercier A. Joffre , Friedrich Rainer , Boldt Maria 
Published: January 2003

AbstractNeuropeptides play important roles in chemical signalling in the central and peripheral nervous systems. One of the largest families of neuropeptides is that of the FMRFamide‐like peptides (FLPs). This paper reviews what is known about the physiological functions of FLPs in crustaceans, focussing on the cardiovascular, digestive and neuromuscular systems. Microsc. Res. Tech. 60:313–324, 2003. © 2003 Wiley‐Liss, Inc.