bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative studies on the movement of fluid and lymphocytes through periodontal tissue and into the draining lymph
Authors: Au Binh , McCulloch Christopher A. G. , Hay John B. 
Published: August 2002

AbstractChronic lymph drainage techniques in sheep have been used to map the pathways and to quantify the fluid and cell traffic through periodontal tissues. The continuous collection of cervical and prescapular lymph has demonstrated that 65% of labelled protein tracer injected into the periodontal tissues could be found in lymph over a period of 7.5 hours. Nearly 90% of the total radioactivity could be accounted for between the lymph and the tissue site. When silk was impregnated with radiolabelled albumin and a tooth ligated, the kinetics of the subsequent appearance of the tracer in lymph emphasized the ease with which macromolecules surrounding the teeth gain access to the lymphatics, regional lymph nodes, and immune apparatus. Animals were primed with BCG and then tuberculin (delayed hypersensitivity) lesions were simultaneously induced in the skin, bowel, and periodontium. When T cells were labelled with radioisotopes and their migration from blood to lymph measured, the periodontal tissue traffic pattern was distinct from the traffic pattern through DTH in the skin and also distinct from the pattern through the small intestine. This indicates that the lymphocyte traffic through the inflamed periodontium has unique features. This tissue specificity was not apparent when lesions were induced with TNFα. The static assessment of lymphocyte subsets within the tissues was also assessed with immunohistochemistry. Microsc. Res. Tech. 56:66–71, 2002. © 2002 Wiley‐Liss, Inc.
The pars intercerebralis of the locust brain: A developmental and comparative study
Authors: Ludwig Peter , Williams Leslie , Boyan George 
Published: August 2002

AbstractThe anterior midline of the brain, also known as the pars intercerebralis, contains the largest collection of neurosecretory cells in the central nervous system of the grasshopper. In this study, we use immunocytochemical, intracellular staining, and histological methods to establish the ontogenies of the various cell types in the brain midline, and show how these cells contribute to the pars intercerebralis of the adult brain. We show that the adult pars intercerebralis develops from three distinct embryonic cell groups: (1) the median neurosecretory cells, which derive from a subset of neuroblasts in the protocerebral hemispheres, and which project axons to the corpora cardiaca; (2) the paired primary commissure pioneers, which derive directly from the mesectoderm of the dorsal median domain and whose axons project to the ventral nerve cord via the midline tract; and (3) the six progeny of the median precursor in the dorsal median domain, which share a common axonal projection with the primary commissure pioneers. Since the adult pars intercerebralis is a fusion product of these independent cellular components, it can only be understood in terms of its origins in the embryonic brain. When the expression pattern of the TERM‐1 antigen is compared in subsets of median neurosecretory cells in a wide range of insect orders, the results suggests a common organizational Bauplan for the pars intercerebralis. This hypothesis is supported by the identification of putative homologs of the grasshopper primary commissure pioneers in all these insects. Microsc. Res. Tech. 56:174–188, 2002. © 2002 Wiley‐Liss, Inc.
Molecular phenotype of Fragile X syndrome: FMRP, FXRPs, and protein targets
Authors: Kaufmann Walter E. , Cohen Sonia , Sun Hong‐Tao , Ho George 
Published: August 2002

AbstractFragile X syndrome (FraX) is one of the most prevalent genetic causes of mental retardation. FraX is associated with an unstable expansion of a polymorphism within the 5′ untranslated region of the FMR1 gene. The main consequence of this mutation is a reduction in the levels of the gene product (FMRP). FMRP is an RNA‐binding protein with multiple spliced variants (isoforms) and high levels of expression in a variety of tissues, including neurons. In the latter cells, it is localized not only to the perikaryon but also to dendrites and dendritic spines. FMRP belongs to a family of proteins that includes the Fragile X Related Proteins or FXRPs. FXRPs share high homology in their functional domains with FMRP, and also associate with mRNA and components of the protein synthesis apparatus. However, FXRPs do not have the same temporo‐spatial pattern of distribution (and other properties) of FMRP. Immunochemical assays have confirmed that a functionally uncompensated FMRP deficit is the essence of the FraX molecular phenotype. Here, we report our preliminary study on FXRPs levels in leukocytes from FraX males. By immunoblotting, we found that a marked reduction in FMRP levels is associated with a modest increase in FXR1P and no changes in FXR2P levels. The consequences of this reduced FMRP expression on protein synthesis, in other words, the identification of FMRP targets, can be studied by different molecular approaches including protein interaction and proteomics methods. By two‐dimensional gel electrophoresis, we showed that in FraX leukocytes there is a defect in acetylation that involves prominently the regulatory protein annexin‐1. Extension of current studies of the molecular phenotype to more brain‐relevant tissue samples, a wider range of proteomics‐based methods, and correlative analyses of FMRP homologues and FMRP targets with multiple behavioral measures, will greatly expand our understanding of FraX pathogenesis and it will help to develop and monitor new therapeutic strategies. Microsc. Res. Tech. 57:135–144, 2002. © 2002 Wiley‐Liss, Inc.
From theory to therapy: Implications from an in vitro model of ramified microglia
Authors: Rosenstiel Philip , Lucius Ralph , Deuschl Günther , Sievers Jobst , Wilms Henrik 
Published: August 2002

AbstractMicroglia are the principal immune cells in the central nervous system (CNS), characterized by a highly specific morphology and unusual antigenic phenotype. An increasing number of studies have focused on the role of microglia in the pathogenesis of neurodegenerative diseases. To elucidate the function of microglial cells under several neuropathological conditions, we have studied and established a cell culture model that allows us to cultivate microglial cells in their inactive, resting (ramified) phenotype. In the first part of this work, we describe the interaction of microglia cells with their epithelial (astrocytic) microenvironment. The second part reviews experiments with microglia cell cultures to elucidate underlying signalling pathways and summarizes recent advances of our knowledge in microglial molecular pathways that may ultimately lead to neurodegeneration. Microsc. Res. Tech. 54:18–25, 2001. © 2001 Wiley‐Liss, Inc.
Distribution and regulation of substance P‐related peptide in the frog visual system
Authors: Debski Elizabeth A. 
Published: August 2002

AbstractModulation of visual signal activity has consequences for both signal processing and for activity‐dependent structuring mechanisms. Among the neuromodulatory agents found in visual areas are substance P (SP)‐related peptides. This article reviews what is known about these substances in the amphibian retina and optic tectum with special emphasis on the leopard frog, Rana pipiens. It is found that the distribution of these SP‐related peptides is remarkably similar to that seen in mammals. This suggests that study of model amphibian systems may significantly enhance our understanding of how neuropeptides contribute to visual system function and organization. Microsc. Res. Tech. 54:220–228, 2001. © 2001 Wiley‐Liss, Inc.
Intensity‐dependent phase‐adjustments in the locomotor activity rhythm of the nocturnal field mouse Mus booduga
Authors: Sharma Vijay Kumar , Chidambaram R. 
Published: August 2002

AbstractThe locomotor activity rhythm of the nocturnal field mouse Mus booduga was monitored under constant darkness (DD) and free‐running periods (τ) were estimated. Following a free‐run of about 15 days in DD, the animals were exposed to periodic light pulses (LPs) of various intensities (1 lux, 10 lux, 50 lux, 100 lux, and 1,000 lux) and 15 minutes duration for 65 days at intervals of 24 hours to investigate the influence of intensity of light on the phase‐angle‐difference (ψ) between the onset of locomotor activity and the time of LP administration. The experimentally observed values of ψ and τ for a LP of 1,000 lux intensity used for 15 minutes every 24 hr, showed a sigmoid shaped relationship with τ. This relationship was similar to that predicted based on the nonparametric model of entrainment, which uses the τ and the LP phase response curve (PRC) constructed using LP of similar duration and intensity. The functional nature of the relationship between ψ and τ was not found to change significantly with increasing intensities of LP used to entrain the locomotor activity rhythm. However, ψ was significantly modulated by the intensity of LP. These results suggest that the periodic sensitivity of the circadian pacemaker underlying the locomotor activity rhythm in the nocturnal field mouse M. booduga to LPs plays an important role in maintaining a characteristic ψ with the zeitgeber and the ψ changes in a light intensity‐dependent manner. J. Exp. Zool. 292:444–459, 2002. © 2002 Wiley‐Liss, Inc.
Role of motility in embryonic development I: Embryo movements and amnion contractions in the chick and the influence of illumination
Authors: Wu K.‐C. , Streicher J. , Lee M.L. , Hall B.K. , Müller G.B. 
Published: August 2002

AbstractThis study provides a quantitative analysis of the active movements of the chick embryo and of the contractions of the amnion over the entire developmental period of 21 days. Four types of embryo movements are distinguished. The motor activity of the embryo shows two characteristic peaks, with maximum contraction frequencies on the 12th and on the 16th day. In contrast, the amnion activity is higher at earlier stages and decreases as the body activity increases. The amnion activity is largely independent of the body activity. Illumination has a strong influence on embryo movements. It is shown that increases of light intensity affect the patterns of activity of both the embryo and the amnion. While the effect of light on the embryo can be interpreted as being transmitted via the optic system, the mechanism of the amniotic response is unclear. The results suggest that the amnion itself may be sensitive to light. J. Exp. Zool. (Mol. Dev. Evol.) 291:186–194, 2001. © 2001 Wiley‐Liss, Inc.
Comparison of the gonadal development and plasma levels of sex steroid hormones in diploid and triploid sea bass, Dicentrarchus labrax L.
Authors: Felip Alicia , Piferrer Francesc , Carrillo Manuel , Zanuy Silvia 
Published: August 2002

AbstractThe goal of this study was to compare the reproductive physiology of triploid and diploid European sea bass (Dicentrarchus labrax L.). Gonads of diploid and triploid fish (males and females) were examined both microscopically and macroscopically, together with the plasma levels of the major sex steroids produced (testosterone and estradiol‐17β) when fish were adults. Prior to sexual maturation, the gonadosomatic index (GSI) of triploid males was similar to that of diploids. However, the GSI in 4‐year‐old adult triploid males was 1.8 times lower than that of diploids (P < 0.05). All diploid males exhibited normal gonadal development. In contrast, in triploid males spermatogenesis was impaired during late meiosis, affecting severely spermiogenesis. This was achieved by an increasing imbalance in the amount of DNA present in daughter cells of the same type as spermatogenesis progressed, as demonstrated by abnormal cell sizes, culminating in inviable spermatids. Thus, no spermiating triploid fish were observed during 4 years, which included three full consecutive maturation cycles. Furthermore, the germ cells from triploids were significantly larger than those from diploids (P < 0.001). Seasonal profiles of plasma levels of testosterone in 4‐year‐old males were essentially similar in both ploidies. On the other hand, triploid females had rudimentary ovaries containing oogonia and primary oocytes that were arrested during meiotic prophase I, while diploid females exhibited all stages of ovarian development. Diploid females showed levels of testosterone and estradiol‐17β significantly higher than those of triploids (P < 0.05), in which no endocrine signs of maturation were observed at all. Regarding sex ratios, triploids had 10% more females than diploids (P < 0.05) but in both ploidies males predominated, as is usually found in this species under culture conditions. These results show that triploidy blocked the initial phases of meiosis in females and the latter ones in males, resulting in the absence of or reduced gonadal development, respectively. In conclusion, we provide an explanation for the lack of gonadal development in triploid male fish, and, to the best of our knowledge, we report for the first time a case in which induced triploidy completely blocks meiosis in both sexes, thus conferring functional sterility in the sea bass. J. Exp. Zool. 290:384–395, 2001. © 2001 Wiley‐Liss, Inc.
Fibroblast growth factors in regenerating limbs of Ambystoma: Cloning and semi‐quantitative RT‐PCR expression studies
Authors: Christensen Randolph N. , Weinstein Michael , Tassava Roy A. 
Published: August 2002

AbstractUrodele amphibians (newts and salamanders) have the ability to regenerate amputated limbs throughout their life span. Because fibroblast growth factors (Fgfs) play important roles in developing limbs, we initiated studies to investigate these growth factors in regenerating limbs. Partial cDNAs of Fgf4, 8, and 10 were cloned from both the Mexican axolotl, Ambystoma mexicanum, and locally collected spotted salamander, Ambystoma maculatum, two salamanders well recognized for their regenerative capabilities. cDNAs from the two Ambystoma species were virtually identical, ranging from 97–100% nucleotide identity. Axolotl Fgf4, 8, and 10 showed nucleotide sequence identity with chick Fgf4, 8, and 10 of 79%, 83%, and 72%, respectively. RT‐PCR showed that these growth factors are expressed in regenerating axolotl limbs as well as in developing salamander larvae at the three‐digit forelimb stage. Fgf8 and 10 are upregulated during regeneration and thus may be involved in distal signaling similar to that of the developing chick limb. Fgf4, however, was undetectable by RT‐PCR in the distal tips of regenerates, suggesting that it does not play the same role in limb regeneration that it does in limb development. We also investigated the role these Fgfs may have in the nerve‐dependence of regeneration. They were expressed similarly in aneurogenic and innervated limbs, suggesting that they are not the neurotrophic factors responsible for nerve‐dependence. Denervation prevented Fgf8 and 10 upregulation, suggesting Fgf pathways are downstream of nerve‐dependence. These data highlight important similarities and differences in Fgf expression between limb development and limb regeneration. J. Exp. Zool. 290:529–540, 2001. © 2001 Wiley‐Liss, Inc.
Using heterochrony plots to detect the dissociated coevolution of characters
Authors: Schlosser Gerhard 
Published: August 2002

AbstractThe comparison of developmental sequences among species is notoriously difficult. Here, heterochrony plots are introduced as a new graphic method to detect temporal shifts in the development of characters in pair‐wise species comparisons. Plotting the timing of character development in one species against the timing of character development in another species allows us to compare a principally unlimited number of characters simultaneously and can detect whether suites of characters are dissociated from one another or not. Such heterochrony plots can be embedded into a comparative phylogenetic analysis in order to establish whether observed patterns of character codissociation are indeed due to their dissociated coevolution. Comparative phylogenetic analysis may also reveal multiple independent events of dissociated coevolution of the same suite of characters in a certain lineage, suggesting that the characters of this suite reciprocally constrain their evolutionary modifiability, thereby forming a unit of evolution. This ability to identify units of evolution is a prerequisite for assessing the validity of recently proposed scenarios, suggesting that modules of development and/or function tend to act as units of evolution. Starting from a detailed heterochrony plot comparing development in the direct developing frog Eleutherodactylus coqui and in the biphasically developing frog Discoglossus pictus, this comparative approach is illustrated focusing on the evolution of development of limbs, the nervous system and the pharyngeal arches in amphibians. J. Exp. Zool. (Mol. Dev. Evol.) 291:282–304, 2001. © 2001 Wiley‐Liss, Inc.
Responses of seminal vesicle and testicular β‐glucuronidase and β‐N‐acetylglucosaminidase to testosterone and some metabolites in Heteropneustes fossilis (Bloch)
Authors: Chowdhury I. , Joy K.P. 
Published: August 2002

AbstractIntraperitoneal administration of testosterone for 20 days produced differential effects on β‐glucuronidase and β‐N‐acetylglucosaminidase (β‐Glc) activity in seminal vesicle (SV) and testis of the catfish Heteropneustes fossilis in preparatory phase (March). The lower dosages of 0.25 and 0.5 μg/g body weight (BW) of the steroid did not alter enzyme activity, and the higher dosages (1.0 and 2.0 μg/g BW) inhibited it significantly. Under in vitro conditions, addition of ascorbate and fructose (0.5–100 mM) to the incubation medium influenced enzyme activity differentially. At concentrations 0.5 and 1.0 mM, both fructose and ascorbate were ineffective except for the inhibition of testicular β‐Glc activity in the 1.0 mM ascorbate group. At higher concentrations (10, 50, and 100 mM), ascorbate inhibited enzyme activity in a concentration‐dependent manner. At 10 mM concentration of fructose, only testicular β‐Glc activity was inhibited, but at higher concentrations (50 and 100 mM), activities of both enzymes decreased uniformly in a concentration‐dependent manner. The addition of glucose had no significant effect on the enzyme activity at any of the concentrations tested. The results suggest that the inhibitory effect of testosterone on enzyme activity may be mediated through androgen‐dependent metabolites, such as fructose and ascorbate. J. Exp. Zool. 290:777–782, 2001. © 2001 Wiley‐Liss, Inc.
Coloring all directed paths in a symmetric tree, with an application to optical networks*
Authors: Gargano Luisa , Hell Pavol , Perennes Stephane 
Published: August 2002

AbstractLet T be a symmetric directed tree, i.e., an undirected tree with each edge viewed as two opposite arcs. We prove that the minimum number of colors needed to color the set of all directed paths in T, so that two paths of the same color never use the same directed arc of T, is equal to the maximum number of different paths that contain the same arc of T. The proof implies a polynomial time algorithm for actually coloring the paths with the minimum number of colors. When only a subset of the directed paths is to be colored, the problem is known to be NP‐complete; we describe certain instances of the problem which can be efficiently solved. These results are applied to WDM (wavelength‐division multiplexing) routing in all‐optical networks. In particular, we solve the all‐to‐all gossiping problem in optical networks. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 183–196, 2001
A conveníent production of [13N]nitrogen for ventilation studies using a nitrogen gas target for 11C production
Authors: Bars D. Le 
Published: August 2002

AbstractTaking advantage of the 14N(p,pn)13N reaction occuring during the 14N(p,α)11C carbon dioxide production, pure [13N]N2 suitable for PET ventilation studies was produced in a standard nitrogen gas target for 11C‐production (“carbon‐11 target”), after elimination of 11CO2 and short‐lived oxygens. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of [3(R)‐amino‐2(S)‐sulfhydryl‐5‐sulfonate]‐pentanoyl‐(S)‐3‐[125I]‐iodotyrosyl‐(S)‐aspartic acid: a radiolabelled inhibitor of aminopeptidase A
Authors: David‐Basei Christelle , Bischoff Laurent , Fournie‐Zaluski Marie‐Claude , Roques Bernard P. 
Published: August 2002

AbstractIn order to investigate the localization of aminopeptidase A in the central nervous system and peripheral organs, we have synthesized the first radiolabelled inhibitor of this enzyme. This molecule, [3(R)‐amino‐2(S)‐sulfhydryl‐5‐sulfonate]‐pentanoyl‐(S)‐3‐[125I]‐iodotyrosyl‐(S)‐aspartic acid, exhibited a Ki value of 4.8 nM for aminopeptidase A. A high purity was obtained with a specific activity of about 2,000 Ci/mmol at the end of the synthesis. Copyright © 2001 John Wiley & Sons, Ltd.
Digestive, salivary, and reproductive organs of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type
Authors: Ghanim Murad , Rosell Rosemarie C. , Campbell Leslie R. , Czosnek Henryk , Brown Judith K. , Ullman Diane E. 
Published: August 2002

AbstractA microscopic analysis of the morphology and ultrastructure of the digestive, salivary, and reproductive systems of adult Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) B type was conducted using light, scanning, and transmission electron microscopy. The internal anatomy of B. tabaci was found to be similar to that reported for Trialeurodes vaporariorum. In a microscopic analysis of the salivary glands, we have shown that each primary salivary gland is composed of at least 13 cells varying in morphology and staining differentially, while the accessory salivary glands are composed of four morphologically similar cells. We analyzed the course of the alimentary canal in B. tabaci, demonstrated the internal morphology of the organs, and clarified the location of the filter chamber relative to other organs in the whitefly. Our observations confirm that the pair of structures extending from the connecting chamber are caeca that may aid in fluid movement through the midgut and are not Malpighian tubules, as previously suggested. We confirm an earlier finding that the whitefly lacks Malpighian tubules, having instead specialized Malpighian‐like cells within the filter chamber at the juncture with the internal ileum. Finally, we provide the first scanning electron microscopic analysis showing the reproductive organs of B. tabaci. Our investigation provides clarified terminology for several components of the digestive and excretory system. We also provide drawings and micrographs that will aid future researchers in localizing the internal organs of B. tabaci. We expect our analysis to provide a valuable tool for studying B. tabaci / plant virus interactions and physiological and biological aspects of this insect. J. Morphol. 248:22–40, 2001. © 2001 Wiley‐Liss, Inc.