bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glial modulation of synaptic transmission in the retina
Authors: Newman Eric A. 
Published: July 2004

AbstractGlial modulation of synaptic transmission and neuronal excitability in the mammalian retina is mediated by several mechanisms. Stimulation of glial cells evokes Ca2+ waves, which propagate through the network of retinal astrocytes and Müller cells and result in the modulation of the activity of neighboring ganglion cells. Light‐evoked spiking is enhanced in some ganglion cells and depressed in others. A facilitation or depression of light‐evoked excitatory postsynaptic currents is also seen in ganglion cells following glial stimulation. In addition, stimulation of glial cells evokes a sustained hyperpolarizing current in ganglion cells which is mediated by ATP release from Müller cells and activation of neuronal A1 adenosine receptors. Recent studies reveal that light‐evoked activity in retinal neurons results in an increase in the frequency of Ca2+ transients in Müller cells. Thus, there is two‐way communication between neurons and glial cells, suggesting that glia contribute to information processing in the retina. © 2004 Wiley‐Liss, Inc.
Synaptic signaling between neurons and glia
Authors: Lin Shih‐Chun , Bergles Dwight E. 
Published: July 2004

AbstractRapid signaling between vertebrate neurons occurs primarily at synapses, intercellular junctions where quantal release of neurotransmitter triggers rapid changes in membrane conductance through activation of ionotropic receptors. Glial cells express many of these same ionotropic receptors, yet little is known about how receptors in glial cells become activated in situ. Because synapses were thought to be the sole provenance of neurons, it has been assumed that these receptors must be activated following diffusion of transmitter out of the synaptic cleft, or through nonsynaptic mechanisms such as transporter reversal. Two recent reports show that a ubiquitous class of progenitors that express the proteoglycan NG2 (NG2 cells) engage in rapid signaling with glutamatergic and γ‐aminobutyric acid (GABA)ergic neurons through direct neuron‐glia synapses. Quantal release of transmitter from neurons at these sites triggers rapid activation of aminomethylisoxazole propionic acid (AMPA) or GABAA receptors in NG2 cells. These currents exhibit properties consistent with direct rather than spillover‐mediated transmission, and electron micrographic analyses indicate that nerve terminals containing clusters of synaptic vesicles form discrete junctions with NG2 cell processes. Although activation of AMPA or GABAA receptors depolarize NG2 cells, these receptors are more likely to serve as routes for ion flux rather than as current sources for depolarization, because the amplitudes of the synaptic transients are small and the resting membrane potential of NG2 cells is highly negative. The ability of both glutamate and GABA to influence the morphology, physiology, and development of NG2 cells in vitro suggests that this rapid form of signaling may play important roles in adapting the behavior of these cells to the needs of surrounding neurons in vivo. © 2004 Wiley‐Liss, Inc.
Dementia, pain, depression, behavioral disturbances, and ADLs: toward a comprehensive conceptualization of quality of life in long‐term care
Authors: Cipher Daisha J. , Clifford P. Andrew 
Published: July 2004

AbstractObjectivesQuality of life in long‐term care settings is a multidimensional construct that includes functional, cognitive, behavioral, and psychological variables. Quality of life variables have been found to be related to one another, but directional influences have not been tested.MethodsThe purpose of this study was to develop and compare two competing path models composed of quality of life variables, including dementia, pain, behavioral disturbances, and ADLs.ResultsPath analytic results revealed that cognitive, emotional, and behavioral variables interact with one another to predict patients' activities of daily living. Pain levels did not influence activities of daily living directly, but rather influenced behavioral disturbances and depression, which in turn influenced activities of daily living.ConclusionsThese preliminary findings suggest that in order to assist long‐term care residents in improving their activities of daily living, decreasing pain is likely to yield the greatest overall improvements. Future research on the relationships between quality of life variables is recommended to further develop multidimensional treatment models for healthcare providers in long‐term care. Copyright © 2004 John Wiley & Sons, Ltd.
Smell identification test as an indicator for cognitive impairment in Alzheimer's disease
Authors: Suzuki Y. , Yamamoto S. , Umegaki H. , Onishi J. , Mogi N. , Fujishiro H. , Iguchi A. 
Published: July 2004

AbstractObjectivesThe aim of the present study was to assess olfactory dysfunction in patients with Alzheimer's disease (AD) and to compare utility of the olfactory tests as possible clinical markers.MethodsTwo olfactory identification tests (The Cross‐Cultural Smell Identification Test [CC‐SIT] and the Picture‐based Smell Identification Test [P‐SIT]) and the Mini Mental State Examination (MMSE) were administered to patients with AD and age‐matched controls. Apolipoprotein E (Apo E) genotypes of patients with AD were identified.ResultsPatients with AD had significantly lower olfactory identification scores than age‐matched non‐demented elderly subjects in both olfactory assessments. In the AD group, the coefficient of correlation between the MMSE scores and the P‐SIT scores was higher than that between the MMSE scores and the CC‐SIT scores. Receiver operating curve (ROC) analyses for both tests indicated that the P‐SIT discriminated AD patients from controls more reliably than did the CC‐SIT. Within AD patients, those who were carrying one or two ApoE ε4 alleles had a higher coefficient of correlation between the MMSE scores and the P‐SIT scores than patients without the ApoE ε4 allele.ConclusionsThe results suggest that a short and simple non‐lexical olfactory identification test can be useful as a clinical marker of AD appropriate for Japanese elderly population. Copyright © 2004 John Wiley & Sons, Ltd.
Expression of p270 (ARID1A), a component of human SWI/SNF complexes, in human tumors
Authors: Wang Xiaomei , Nagl Norman G. , Flowers Stephen , Zweitzig Daniel , Dallas Peter B. , Moran Elizabeth 
Published: July 2004

AbstractHuman SWI/SNF complexes use the energy of ATP hydrolysis to remodel chromosomes and alter gene expression patterns. The activity of the complexes generally promotes tissue‐specific gene expression and restricts cell proliferation. The ATPase that drives the complexes, BRG1, is essential for tumor suppression in mice and deficient in a variety of established human tumor cell lines. The complex contains at least 7 other core components, one of which is a large subunit designated p270. p270 RNA is expressed in all normal human tissues examined, but protein expression is severely reduced in at least 2 human tumor lines, C33A and T47D. We show here that loss of p270 in the C33A and T47D cell lines is evident at the RNA level as well as the protein level. The implication that p270 can be informatively screened at the RNA level made a high‐efficiency cancer profiling array approach to screening human tumors feasible. Expression was screened in an array containing RNA‐derived cDNA from 241 tumor and corresponding matched normal tissues from individual patients. p270 deficiency was observed at a higher overall frequency than BRG1 deficiency, but all tissues were not equally affected. Deficiency of p270 was observed most frequently in carcinomas of the breast and kidney. The results were most striking in kidney, where p270 expression was deficient in 30% of carcinoma samples screened. Screening of a panel of established human renal carcinoma–derived cell lines supports the frequency observed in the primary tumor tissue samples. © 2004 Wiley‐Liss, Inc.
Fine mapping of the 11q22–23 tumor suppressive region and involvement of TSLC1 in nasopharyngeal carcinoma
Authors: Lung Hong Lok , Cheng Yue , Kumaran Mande Kuppusamy , Liu Edison Tak‐Bun , Murakami Yoshinori , Chan Cheuk Yu , Yau Wing Lung , Ko Josephine Mun Yee , Stanbridge Eric J. , Lung Maria Li 
Published: July 2004

AbstractPrevious studies transferring an intact chromosome 11 into HONE1 cells demonstrated the functional significance of chromosome regions, 11q13 and 11q22–23, in nasopharyngeal carcinoma (NPC) development. In our study the 11q22–23 region was comprehensively re‐investigated by detailed microsatellite and single nucleotide polymorphism genotyping and by fluorescence in situ hybridization to map precisely the regions containing tumor suppressive activity. We observed 3 chromosomal intervals within 11q22–23 that were commonly lost in the tumor segregants derived from HONE1/chromosome 11 hybrids. One critical region of 0.36 Mb was mapped near the marker D11S2000 and a second 0.44 Mb region was located around the markers D11S1300 and D11S1391. In a third region high allelic loss was also observed at marker D11S4484, where a newly cloned tumor suppressor gene, TSLC1 (tumor suppressor in lung cancer 1), is located. The gene expression analysis showed absence or low expression levels of TSLC1 mRNA in 4 highly tumorigenic NPC cell lines. In addition, the methylation study results show that the TSLC1 promoter region was hypermethylated in all 4 NPC cell lines and re‐expression of the gene occurs in HONE1 cells after 5‐aza‐2′‐deoxycytidine treatment. Hence, the mode of silencing of this candidate TSG in NPC may be attributed to promoter hypermethylation. We have obtained functional evidence for multiple critical tumor suppressive regions in 11q22–23 by fine deletion mapping and for inactivation of TSLC1 being one of these candidate TSGs in NPC development. © 2004 Wiley‐Liss, Inc.
Mechanistic studies on protopanaxadiol, Rh2, and ginseng (Panax quinquefolius) extract induced cytotoxicity in intestinal Caco‐2 cells
Authors: Popovich David G. , Kitts David D. 
Published: July 2004

AbstractCertain ginsenosides, also known as triterpene glycosides, have been recently reported to have a characteristic effect on cultured intestinal and leukemia cell growth. Ginsenoside aglycones 20(S)‐protopanaxadiol (PD), 20(S)‐protopanaxatriol (PT), and ginsenoside Rh2 have been identified as having a strong effect on reducing cell viability. Furthermore, ginsenoside Rh2 is thought to be a rare ginsenoside not found in all ginseng products. Rather, Rh2 has been recently reported to be a breakdown product of thermal processing of North American ginseng. In this study, pure ginsenosides PD, PT, Rh2 standards and an enriched Rh2 fraction derived from ginseng leaf were tested in cultured Caco‐2 cells for relative cytotoxic potency. PD and Rh2 LC50 were similar after 24 to 72 h, whereas a drop in PT LC50 occurred later at 48 and 72 h. Furthermore, PD and Rh2 affected membrane integrity as indicated by LDH secretion earlier than PT and the enriched Rh2 fraction (P ≤ 0.05). Ginsenoside Rh2 showed the greatest (P ≤ 0.05) build up of necrotic cells (18.3 ± 0.1%) at the respective LC50 after 24 h and PD (21.3 ± 0.3%) showed the largest effect after 44 h of exposure. The effect on apoptotic cells at 44 h of treatment were significantly different (P ≤ 0.05) for Rh2 (21 ± 0.4%), PD (14.6 ± 0.1%), enriched Rh2 leaf fraction (9.9 ± 0.6%), and PT (2.3 ± 0.1%) treatments. Caco‐2 caspase‐3 activity was different between ginsenoside exposure; Rh2 (10.6 ± 0.3 nM pNA) had the greatest (P ≤ 0.05) activity followed by the enriched Rh2 leaf fraction (8.3 ± 0.2 nM pNA), PT (7.3 ± 0.3 nM pNA). The PD (4.8 ± 0.04 nM pNA) treatment was similar to untreated cells (4.3 ± 0.05 nM pNA) in caspase‐3 activity. These results show variable bioactive response in cultured intestinal cell to specific ginsenosides and an enriched Rh2 North American ginseng extract which may be explained on basis of hydrophobic/hydrophilic balance. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:143–149, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20019
The structure and function of auditory chordotonal organs in insects
Authors: Yack Jayne E. 
Published: July 2004

AbstractInsects are capable of detecting a broad range of acoustic signals transmitted through air, water, or solids. Auditory sensory organs are morphologically diverse with respect to their body location, accessory structures, and number of sensilla, but remarkably uniform in that most are innervated by chordotonal organs. Chordotonal organs are structurally complex Type I mechanoreceptors that are distributed throughout the insect body and function to detect a wide range of mechanical stimuli, from gross motor movements to air‐borne sounds. At present, little is known about how chordotonal organs in general function to convert mechanical stimuli to nerve impulses, and our limited understanding of this process represents one of the major challenges to the study of insect auditory systems today. This report reviews the literature on chordotonal organs innervating insect ears, with the broad intention of uncovering some common structural specializations of peripheral auditory systems, and identifying new avenues for research. A general overview of chordotonal organ ultrastructure is presented, followed by a summary of the current theories on mechanical coupling and transduction in monodynal, mononematic, Type 1 scolopidia, which characteristically innervate insect ears. Auditory organs of different insect taxa are reviewed, focusing primarily on tympanal organs, and with some consideration to Johnston's and subgenual organs. It is widely accepted that insect hearing organs evolved from pre‐existing proprioceptive chordotonal organs. In addition to certain non‐neural adaptations for hearing, such as tracheal expansion and cuticular thinning, the chordotonal organs themselves may have intrinsic specializations for sound reception and transduction, and these are discussed. In the future, an integrated approach, using traditional anatomical and physiological techniques in combination with new methodologies in immunohistochemistry, genetics, and biophysics, will assist in refining hypotheses on how chordotonal organs function, and, ultimately, lead to new insights into the peripheral mechanisms underlying hearing in insects. Microsc. Res. Tech. 63:315–337, 2004. © 2004 Wiley‐Liss, Inc.
Nephridial and gonoduct distribution patterns in Nerillidae (Annelida: Polychaeta) examined by tubulin staining and cLSM
Authors: Worsaae Katrine , Müller Monika C.M. 
Published: July 2004

AbstractThe distribution and configuration of nephridia and gonoducts are described for seven species from seven genera of the interstitial polychaete family Nerillidae. The ciliated nephridia and gonoducts were identified by tubulin staining and examined with a confocal laser scanning microscope. The following species of the seven to nine‐segmented nerillids were examined: Leptonerilla prospera, Nerilla antennata (nine segments); Nerillidium mediterraneum, Trochonerilla mobilis, Gen. sp. A (eight segments); and Aristonerilla brevis, Paranerilla limicola (seven segments). Two of the examined species are hermaphroditic (N. mediterraneum and Gen. sp. A). Segmented nephridia can be found from the first to the last segment, with a total of two to five pairs. One to three pairs of segmented spermioducts are present in all species. One pair of gonoducts is found in all species, except for P. limicola, where they are absent. Nephridia vary in length from half to almost twice the length of a segment and may be curled up in loops. In A. brevis and P. limicola the nephridia are discontinuously ciliated. The distribution and configuration of spermioducts and gonoducts are also variable, although to a lesser extent. The spermioduct distribution is generally consistent within genera and therefore of systematic significance. Nephridia and gonoducts are never found together in the same segments, and the results indicate that gonoducts and nephridia have developed from the same anlagen. The distribution patterns of nephridia and gonoducts are discussed with respect to segmentation, systematics, and development. J. Morphol. 261:259–269, 2004. © 2004 Wiley‐Liss, Inc.
Development of the islets, exocrine pancreas, and related ducts in the Nile tilapia, Oreochromis niloticus (Pisces: Cichlidae)
Authors: Morrison Carol M. , Pohajdak Bill , Tam Janet , Wright James R. 
Published: July 2004

AbstractPancreatic development and the relationship of the islets with the pancreatic, hepatic, and bile ducts were studied in the Nile tilapia, Oreochromis niloticus, from hatching to the onset of maturity at 7 months. The number of islets formed during development was counted, using either serial sections or dithizone staining of isolated islets. There was a general increase in islet number with both age and size. Tilapia housed in individual tanks grew more quickly and had more islets than siblings of the same age left in crowded conditions. The pancreas is a compact organ in early development, and at 1 day posthatch (dph) a single principal islet, positive for all hormones tested (insulin, SST‐14, SST‐28, glucagon, and PYY), is partially surrounded by exocrine pancreas. However, the exocrine pancreas becomes more disseminated in older fish, following blood vessels along the mesenteries and entering the liver to form a hepatopancreas. The epithelium of the pancreatic duct system from the intercalated ducts to the main duct entering the duodenum was positive for glucagon and SST‐14 in 8 and 16 dph tilapia. Individual insulin‐immunopositive cells were found in one specimen. At this early stage in development, therefore, the pancreatic duct epithelial cells appear to be pluripotent and may give rise to the small islets found near the pancreatic ducts in 16–37 dph tilapia. Glucagon, SST‐14, and some PPY‐positive enteroendocrine cells were present in the intestine of the 8 dph larva and in the first part of the intestine of the 16 dph juvenile. Glucagon and SST‐14‐positive inclusions were found in the apical cytoplasm of the mid‐gut epithelium of the 16 dph tilapia. These hormones may have been absorbed from the gut lumen, since they are produced in both the pancreatic ducts and the enteroendocrine cells. At least three hepatic ducts join the cystic duct to form the bile duct, which runs alongside the pancreatic duct to the duodenum. J. Morphol. 261:377–389, 2004. © 2004 Wiley‐Liss, Inc.
Fine structure of marsupial hairs, with emphasis on trichohyalin and the structure of the inner root sheath
Authors: Alibardi Lorenzo 
Published: July 2004

AbstractThe fine structure and cornification of marsupial hairs are unknown. The distribution of keratins, trichohyalin, and transglutaminase in marsupial hairs was studied here for the first time by electron microscopy and immunocytochemistry. The localization of acidic and basic keratins in marsupial hairs is similar to that of hairs in placental mammals, and the keratins are mainly localized in the outer root sheath and surrounding epidermis. Marsupial trichohyalin in both medulla and inner root sheath (IRS) cross‐reacts with a trichohyalin antibody that recognizes trichohyalin across placental species, indicating a common epitope(s) among mammalian trichohyalin. Roundish to irregular trichohyalin granules are composed of a network of immunolabeled 10–15‐nm‐thick coarse filaments within an amorphous matrix in which a weak labeling for transglutaminases is present. This suggests that the enzyme, and its substrate trichohyalin, are associated in mature granules. Transglutaminase labeling mainly occurs in condensing chromatin of mature cells of the outer and inner root sheaths, suggesting formation of the nuclear envelope connected with terminal differentiation of these cells. In mature Huxley or Henle layers the filaments lose the immunolabeling for trichohyalin when they are reoriented into parallel rows linked by short bridges, thus suggesting that the filaments with their reactive epitopes are chemically modified during cornification, as seen in the IRS of hairs of placental mammals. The Huxley layer probably acts as a cushion, absorbing the tensions connected with the distalward movement of the growing hair fiber. Variations in stratification of the Huxley layer are probably related to the diameter of the hair shaft. The cytoplasmic and junctional connections between cells of the Huxley layer and the companion layer and the outer root sheath enhance the grip of the IRS and hair fiber within the follicle. The role of cells of the IRS in sculpturing the fiber cuticle and in the mechanism of shedding that allows the exit of hair on the epidermal surface in mammals are discussed. J. Morphol. 261:390–402, 2004. © 2004 Wiley‐Liss, Inc.
Self‐Assembled Monolayer Formed by a Rhenium Complex Containing Hyperbranched Polymer
Authors: Tse Chui W. , Cheng Kai W. , Chan Wai K. , Djurišić Aleksandra B. 
Published: July 2004

AbstractSummary: The synthesis of a hyperbranched polymer containing a rhenium bipyridine complex is reported. The polymer was synthesized from a monomer that contains two chlorotricarbonyl rhenium(I) bipyridine moieties and a stilbazole ligand, and the polymer was formed by the coordination reaction in one single step. Gel permeation chromatography results showed that the resulting polymer had a strong interaction with the column packing material, which was reduced when the eluent was added with an electrolyte. Both atomic force microscopy and laser light scattering showed that the size of the polymer molecules was in the range between 25–30 nm. A monolayer of polymer molecules could form on a pretreated substrate by the self‐assembly process, which can serve as the building block for multilayer ultrathin film devices.The metal‐containing hyperbranched polymer synthesized here.magnified imageThe metal‐containing hyperbranched polymer synthesized here.
Novel Approach of Evaluating Polymer Nanocomposite Structure by Measurements of the Freezing‐Point Depression
Authors: López‐Manchado Miguel A. , Valentín Juan L. , Herrero Berta , Arroyo Miguel 
Published: July 2004

AbstractSummary: A novel experimental approach based on the freezing‐point depression of a solvent in a swollen gel has been developed to characterize the structure of nanocomposites. A higher depression in the freezing point has been related with an exfoliated nanocomposite. This increased depression not only depends on the formation of a tighter network but also on the decrease of the size of the solvent cages where the nucleation takes place.The nucleation process of unfilled and organoclay‐filled natural rubber with the same crosslinking density.magnified imageThe nucleation process of unfilled and organoclay‐filled natural rubber with the same crosslinking density.