bluuebunny/crossref_metadata_2025_split huggingface dataset:
Connexin36, an essential element in the rod pathway, is highly expressed in the essentially rodless retina of Gallus gallus
Authors: Kihara A.H. , Paschon V. , Cardoso C.M. , Higa G.S.V. , Castro L.M. , Hamassaki D.E. , Britto L.R.G. 
Published: December 2008

AbstractElectrical coupling provided by connexins (Cx) in gap junctions (GJ) plays important roles in both the developing and the mature retina. In mammalian nocturnal species, Cx36 is an essential component in the rod pathway, the retinal circuit specialized for night, scotopic vision. Here, we report the expression of Cx36 in a species (Gallus gallus) that phylogenetic development endows with an essentially rodless retina. Cx36 gene is very highly expressed in comparison with other Cxs previously described in the adult retina, such as Cx43, Cx45, and Cx50. Moreover, real‐time PCR, Western blot, and immunofluorescence all revealed that Cx36 expression massively increased over time during development. We thoroughly examined Cx36 in the inner and outer plexiform layers, where this protein was particularly abundant. Cx36 was observed mainly in the off sublamina of the inner plexiform layer rather than in the on sublamina previously described in the mammalian retina. In addition, Cx36 colocalized with specific cell markers, revealing the expression of this protein in distinct amacrine cells. To investigate further the involvement of Cx36 in visual processing, we examined its functional regulation in retinas from dark‐adapted animals. Light deprivation markedly up‐regulates Cx36 gene expression in the retina, resulting in an increased accumulation of the protein within and between cone synaptic terminals. In summary, the developmental regulation of Cx36 expression results in particular circuitry‐related roles in the chick retina. Moreover, this study demonstrated that Cx36 onto‐ and phylogenesis in the vertebrate retina simultaneously exhibit similarities and particularities. J. Comp. Neurol. 512:651–663, 2009. © 2008 Wiley‐Liss, Inc.
Age‐related changes in hypothalamic androgen receptor and estrogen receptor α in male rats
Authors: Wu Di , Lin Grace , Gore Andrea C. 
Published: December 2008

AbstractThe control of reproductive function involves actions of sex steroids upon their nuclear receptors in the hypothalamus and preoptic area (POA). Whether hypothalamic hormone receptors change their expression in aging male mammals has not been extensively pursued, although such changes may underlie functional losses in reproductive physiology occurring with aging. We performed a stereologic analysis of immunoreactive androgen receptor (AR) and estrogen receptor alpha (ERα) cells in three POA nuclei of male Sprague‐Dawley rats (anteroventral periventricular nucleus [AVPV], median preoptic area [MePO], and medial preoptic nucleus [MPN]), at young (3 months), middle‐aged (12 months), and old (20 months) ages. Serum testosterone and estradiol levels were assayed. Testosterone concentrations decreased significantly and progressively with aging. Estradiol concentrations were significantly higher in middle‐aged than either young or old rats. Stereologic analyses of the POA demonstrated that AR‐immunoreactive cell numbers and density in the AVPV, MePO, and MPN were significantly higher in old compared with young or middle‐aged rats. No change in the total number or density of ERα‐immunoreactive cells was detected with age, although when cells were subdivided by intensity of immunolabeling, the most heavily labeled ERα cells increased in number with aging in the AVPV and MePO, and in density in the AVPV. There are several interpretations to our finding of substantially increased AR cell numbers during aging, including a potential compensatory upregulation of the AR under diminished testosterone concentrations. These results provide further information about how the neural targets of steroid hormones change with advancing age. J. Comp. Neurol. 512:688–701, 2009. © 2008 Wiley‐Liss, Inc.
Stem cells of the adult cornea: From cytometric markers to therapeutic applications
Authors: Takács Lili , Tóth Enikö , Berta András , Vereb György 
Published: December 2008

AbstractThe cornea is a major protective shield of the interior of the eye and represents two thirds of its refractive power. It is made up of three tissue layers that have different developmental origins: the outer, epithelial layer develops from the ectoderm overlying the lens vesicle, whereas the stroma and the endothelium have mesenchymal origin. In the adult organism, the outermost corneal epithelium is the most exposed to environmental damage, and its constant renewal is assured by the epithelial stem cells that reside in the limbus, the circular border of the cornea. Cell turnover in the stromal layer is very slow and the endothelial cells probably do not reproduce in the adult organism. However, recent experimental evidence indicates that stem cells may be found in these layers. Damage to any of the corneal layers leads to loss of transparency and low vision. Corneal limbal stem cell deficiency results in severe ocular surface disease and its treatment by transplantating ex vivo expanded limbal epithelial cells is becoming widely accepted today. Stromal and endothelial stem cells are potential tools of tissue engineering and regenerative therapies of corneal ulcers and endothelial cell loss. In the past few years, intensive research has focused on corneal stem cells aiming to improve the outcomes of the current corneal stem cell transplantation techniques. This review summarizes the current state of knowledge on corneal epithelial, stromal and endothelial stem cells. Special emphasis is placed on the molecular markers that may help to identify these cells, and the recently revealed mechanisms that could maintain their “stemness” or drive their differentiation. The techniques for isolating and culturing/expanding these cells are also described. © 2008 International Society for Advancement of Cytometry
Suitability of various membrane lipophilic probes for the detection of trogocytosis by flow cytometry
Authors: Daubeuf Sandrine , Bordier Christine , Hudrisier Denis , Joly Etienne 
Published: December 2008

AbstractTrogocytosis is a recently discovered phenomenon whereby lymphocytes capture fragments of the plasma membrane from antigen presenting cells (APCs). Using APCs labeled with widely used fluorescent lipophilic probes, we previously described a trogocytosis analysis protocol (TRAP) useful to understand the mechanisms and biological consequences of this process and to identify lymphocytes reacting specifically with antigen‐bearing APCs. We have compared the suitability of 22 different fluorescent lipophilic probes for use in TRAP assays with cytotoxic T lymphocytes (CTL). The criteria we used were: simple and efficient incorporation in APC membranes, minimal passive diffusion among cells but efficient transfer onto T cells during trogocytosis. Sphingosin‐based probes were found to incorporate inefficiently into cells. For others with unsaturated lipid chains, we found a tendency for extensive passive diffusion. In the end, about a third of the probes tested were found to be suitable in TRAP assays, which all carry either C16 or C18 saturated carbon chains, including some that can be excited with a red laser. Moreover, we found it possible to combine TRAP assays based on lipophilic probes with intracellular cytokine detection. We have identified a set of new lipophilic fluorescent probes suitable for TRAP assays in combination with intracellular staining. © 2008 International Society for Advancement of Cytometry
Single cell analysis reveals unexpected growth phenotype ofS. cerevisiae
Authors: Kortmann Hendrik , Blank Lars M. , Schmid Andreas 
Published: December 2008

AbstractSingle cell analysis is mainly limited to single time‐point measurements, without the possibility to track behavioral changes of a single cell or its descendents. Here, the integration of a spatiotemporal single cell lab‐on‐a‐chip system with an automated cultivation device allows single cell analysis under defined growth conditions and, especially, semiautomated cell retrieval and growth kinetic analysis of the single cell descendants. Performance of the new platform was evaluated using the yeastSaccharomyces cerevisiae. The yeast was singularized in the lab‐on‐a‐chip (Envirostat), which combines the possibility of cell cultivation with cell analysis. Singularized cells were collected in a microtiter plate and cultivated in a semiautomated cultivation device (Bioscreen C).S. cerevisiaeshowed highly reproducible and glucose concentration independent growth kinetics in population experiments. Yet, growth kinetics in cultures inoculated with only one or few cells exhibited strong variations, because of an unexpected growth phenotype: colony formation in submerse cultures. Interestingly, the colony‐like structures grew for more then 60 h and were stable for at least 82 h, despite rigorous shaking. Cell agglomeration due to pseudohyphal growth could be excluded, suggesting changes in cell wall properties of yeast populations starting from a single yeast. Single cell analysis still exhibits unexpected obstacles. Nevertheless, this new single cell analysis platform can be used for studying cellular dynamics of single cells and expanded cell populations thereof. © 2008 International Society for Advancement of Cytometry
Diabetes reduces bone marrow and circulating porcine endothelial progenitor cells, an effect ameliorated by atorvastatin and independent of cholesterol
Authors: Mohler Emile R. , Shi Yuquan , Moore Jonni , Bantly Andrew , Hamamdzic Damir , Yoder Mervin , Rader Daniel J. , Putt Mary , Zhang Lifeng , Parmacek Michael , Wilensky Robert L. 
Published: December 2008

AbstractBone marrow derived endothelial progenitor cells (EPCs) are early precursors of mature endothelial cells which replenish aging and damaged endothelial cells. The authors studied a diabetic swine model to determine if induction of DM adversely affects either bone marrow or circulating EPCs and whether a HMG‐CoA reductase inhibitor (statin) improves development and recruitment of EPCs in the absence of cholesterol lowering. Streptozotocin was administered to Yorkshire pigs to induce DM. One month after induction, diabetic pigs were treated with atorvastatin (statin, n = 10), ezetimibe (n = 10) or untreated (n = 10) and evaluated for number of bone marrow and circulating EPCs and femoral artery endothelial function. There was no effect of either medication on cholesterol level. One month after induction of DM prior to administration of drugs, the number of bone marrow and circulating EPCs significantly decreased (P < 0.0001) compared to baseline. Three months after DM induction, the mean proportion of circulating EPCs significantly increased in the atorvastatin group, but not in the control or ezetimibe groups. The control group showed progressive reduction in percentage of flow mediated vasodilatation (no dilatation at 3 months) whereas the atorvastatin group and ezetimibe exhibited vasodilatation, 6% and 4% respectively. DM results in significant impairment of bone marrow and circulating EPCs as well as endothelial function. The effect is ameliorated, in part, by atorvastatin independent of its cholesterol lowering effect. These data suggest a model wherein accelerated atherosclerosis seen with DM may, in part, result from reduction in EPCs which may be ameliorated by treatment with a statin. © 2008 International Society for Advancement of Cytometry
Rational Design of a Novel Chiral Palladacycle: Synthesis, Optical Resolution, and Stereochemical Evaluation
Authors: Ding Yi , Li Yongxin , Pullarkat Sumod A. , Leng Yap See , Leung Pak‐Hing 
Published: December 2008

AbstractA novel palladacycle was designed and prepared by direct cyclopalladation of the ligand 1‐(3,6‐dimethylnaphthalen‐1‐yl)‐N,N‐dimethylethanamine, which was synthesized by a multistep sequence starting from 2,7‐dimethylnaphthalene. The palladacycle structure and ring conformations of its triphenylphosphane derivative was investigated by X‐ray structural analysis in the solid state and 2D 1H–1H ROESY NMR spectroscopy in solution. The ortho‐palladated ring is stereochemically rigid, and the five‐membered ring conformation is locked by repulsive interactions between the methyl group on the prochiral carbon atom and its neighboring naphthylene proton. The racemic cyclopalladated complex could be efficiently resolved through the formation of its (S)‐prolinato derivatives, and efficient separation of the resulting diastereomeric complexes was achieved by simple silica‐gel chromatography. The structures and absolute configurations of the two optically resolved palladium complexes were determined by X‐ray crystallography. Both the (R,R)‐ and (S,S)‐di‐μ‐chloride dimeric palladium complexes could be obtained chemoselectively by treating the corresponding prolinato derivatives with 1 M hydrochloric acid. Despite the severe interchelate steric constraints within this new organopalladium complex, the bulky monodentate ligand 3,4‐dimethyl‐1‐phenylphosphole (dmpp) was coordinated regiospecifically to the ortho‐palladated amine unit trans to the NMe2 group. In comparison to its naphthylamine analogue, the new palladacycle showed a much higher stereoselectivity in the chiral template‐promoted asymmetric Diels–Alder reaction of coordinated dmpp and N,N‐dimethylacrylamide.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chlorophyll Catabolites – Chemical and Structural Footprints of a Fascinating Biological Phenomenon
Authors: Moser Simone , Müller Thomas , Oberhuber Michael , Kräutler Bernhard 
Published: December 2008

AbstractTwenty years ago, the molecular basis for the seasonal disappearance of chlorophyll was still enigmatic. In the meantime, our knowledge on chlorophyll breakdown has grown considerably. As outlined here, it has been possible to decipher the basic transformations involved in natural chlorophyll breakdown by identification of chlorophyll catabolites in higher plants, and with the help of the synthesis of (putative) catabolic intermediates. In vascular plants, chlorophyll breakdown typically converts the green plant pigments efficiently into colorless and non‐fluorescent tetrapyrroles. It involves colored intermediates only fleetingly and in an (elusive) enzyme‐bound form. The non‐fluorescent chlorophyll catabolites accumulate in the vacuoles of degreened leaves and are considered the products, primarily, of a detoxification process. However, they are effective antioxidants, and may thus also have physiologically beneficial chemical properties.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Optically Active Monoacid Side‐Chains of Cephalotaxus Alkaloids
Authors: Berhal Farouk , Tardy Sébastien , Pérard‐Viret Joëlle , Royer Jacques 
Published: December 2008

AbstractThe general preparation of enantiopure monoacid side‐chains of several esters of cephalotaxine is described. The strategy, similar to Weinreb's approach to the synthesis of deoxyharringtonine, used as key intermediate the chiral nonracemic epoxide 11a prepared from the commercially available monomethyl itaconate (8). The key step of the strategy was the ring‐opening of the epoxide 11a by using different organocuprate nucleophiles. Hydrogenolysis as the final step gave the monacid side‐chains of the corresponding esters of cephalotaxine in moderate to good overall yields from epoxide 11a.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Incremental dynamic analysis of woodframe buildings
Authors: Christovasilis Ioannis P. , Filiatrault Andre , Constantinou Michael C. , Wanitkorkul Assawin 
Published: December 2008

AbstractThe collapse of wood buildings was one of the main contributors to the heavy death toll and economic losses during the 1995 Hyogo‐ken Nanbu (Kobe) earthquake in Japan. In California, half of the property loss from the 1994 Northridge earthquake was attributed to wood construction. Based on damage observed in recent earthquakes, the seismic vulnerability of existing wood buildings under maximum credible seismic events is uncertain. The main objective of this study is to quantify the seismic collapse fragilities and collapse mechanisms of a two‐story townhouse and three‐story woodframe apartment building through numerical analyses. Three construction quality variants (poor, typical and superior) were considered for each building in order to assess the effects of construction qualities on seismic collapse fragilities. The buildings were also re‐designed according to the 2006 edition of the International Building Code to quantify the seismic fragilities of modern woodframe construction. The results obtained suggest that the construction quality, excitation direction and wall finish materials can influence significantly the collapse fragilities of woodframe buildings. Copyright © 2008 John Wiley & Sons, Ltd.
Hybrid mesh generation with embedded surfaces using a multiple marching direction approach
Authors: Ito Yasushi , Shih Alan M. , Soni Bharat K. 
Published: December 2008

AbstractThis paper proposes a method for the creation of hybrid meshes with embedded surfaces for viscous flow simulations as an extension of the multiple marching direction approach (AIAA J. 2007; 45(1):162–167). The multiple marching direction approach enables to place semi‐structured elements around singular points, where valid semi‐structured elements cannot be placed using conventional hybrid mesh generation methods. This feature is discussed first with a couple of examples. Elements sometimes need to be clustered inside a computational domain to obtain more accurate results. For example, solution features, such as shocks, vortex cores and wake regions, can be extracted during the process of adaptive mesh generation. These features can be represented as surface meshes embedded in a computational domain. Semi‐structured elements can be placed around the embedded surface meshes using the multiple marching direction approach with a pretreatment method. Tetrahedral elements can be placed easily instead. A couple of results are presented to demonstrate the capability of the mesh generation method. Copyright © 2008 John Wiley & Sons, Ltd.
Are household subjective forecasts of personal finances accurate and useful? A directional analysis of the British Household Panel Survey
Authors: Easaw Joshy , Heravi Saeed 
Published: December 2008

AbstractThe purpose of the paper is to analyse the accuracy and usefulness of household subjective forecasts of personal finance. We use non‐parametric directional analysis to assess the subjective forecasts which are based on qualitative judgments. Using the British Household Panel Survey (BHPS) we are able to analyse a large number of individuals over a number of years. We also take into account individual characteristics such as gender, age, education and employment status when assessing their subjective forecasts. The paper extends the existing literature in two ways: the accuracy and usefulness of subjective forecasts, based on directional analysis, are assessed at the household level for the first time. Secondly, we adapt and extend the methods of directional analysis, which are applied to the household panel or longitudinal survey. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐term accumulation of microglia with proneurogenic phenotype concomitant with persistent neurogenesis in adult subventricular zone after stroke
Authors: Thored Pär , Heldmann Ursula , Gomes‐Leal Walace , Gisler Ramiro , Darsalia Vladimer , Taneera Jalal , Nygren Jens M. , Jacobsen Sten‐Eirik W. , Ekdahl Christine T. , Kokaia Zaal , Lindvall Olle 
Published: December 2008

AbstractNeural stem cells (NSCs) in the adult rat subventricular zone (SVZ) generate new striatal neurons during several months after ischemic stroke. Whether the microglial response associated with ischemic injury extends into SVZ and influences neuroblast production is unknown. Here, we demonstrate increased numbers of activated microglia in ipsilateral SVZ concomitant with neuroblast migration into the striatum at 2, 6, and 16 weeks, with maximum at 6 weeks, following 2 h middle cerebral artery occlusion in rats. In the peri‐infarct striatum, numbers of activated microglia peaked already at 2 weeks and declined thereafter. Microglia in SVZ were resident or originated from bone marrow, with maximum proliferation during the first 2 weeks postinsult. In SVZ, microglia exhibited ramified or intermediate morphology, signifying a downregulated inflammatory profile, whereas amoeboid or round phagocytic microglia were frequent in the peri‐infarct striatum. Numbers of microglia expressing markers of antigen‐presenting cells (MHC‐II, CD86) increased in SVZ but very few lymphocytes were detected. Using quantitative PCR, strong short‐ and long‐term increase (at 1 and 6 weeks postinfarct) of insulin‐like growth factor‐1 (IGF‐1) gene expression was detected in SVZ tissue. Elevated numbers of IGF‐1‐expressing microglia were found in SVZ at 2, 6, and 16 weeks after stroke. At 16 weeks, 5% of microglia but no other cells in SVZ expressed the IGF‐1 protein, which mitigates apoptosis and promotes proliferation and differentiation of NSCs. The long‐term accumulation of microglia with proneurogenic phenotype in the SVZ implies a supportive role of these cells for the continuous neurogenesis after stroke. © 2008 Wiley‐Liss, Inc.
Microglial cell migration stimulated by ATP and C5a involve distinct molecular mechanisms: Quantification of migration by a novel near‐infrared method
Authors: Miller Aaron M. , Stella Nephi 
Published: December 2008

AbstractMicroglial cells, the macrophages of the brain, play an essential role in the propagation of neuroinflammation. Increased microglial cell migration in response to specific chemoattractants has been documented, but less is known about the differences between these stimuli and the signal transduction pathways that mediate their effects. Current methods to measure cell migration are often labor‐intensive and rely on the manual counting of cell number, so more efficient and objective methods are needed. Here we present an improved and higher‐throughput Boyden chamber technique that measures microglial cell migration by using DRAQ5, a nuclear dye that emits in the near‐infrared. Out of a panel of chemoattractants tested, we found that ATP and C5a potently stimulate the migration of mouse primary microglial cells. The stimulatory effects of ATP and C5a displayed significant additivity, suggesting that each chemoattractant stimulated migration through independent molecular mechanisms. Accordingly, we found key differences in these responses: ATP stimulated a combination of both chemokinesis and chemotaxis, and this response was mediated by the ROCK signaling pathway; whereas C5a stimulated only chemotaxis and this response was mediated by the Rac1 signaling pathway. Finally, we found that functional PI3‐kinase is only required for random basal microglial cell migration. Thus, our results show that distinct nonoverlapping signal transduction pathways control different modes of microglial cell migration and suggest that the targeting of these distinct molecular mechanisms should modulate different aspects of neuroinflammation propagation. © 2008 Wiley‐Liss, Inc.