bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peripherally–derived olfactory ensheathing cells do not promote primary afferent regeneration following dorsal root injury
Authors: Ramer Leanne M. , Richter Miranda W. , Roskams A. Jane , Tetzlaff Wolfram , Ramer Matt S. 
Published: May 2004

AbstractOlfactory ensheathing cells (OECs) may support axonal regrowth, and thus might be a viable treatment for spinal cord injury (SCI); however, peripherally– derived OECs remain untested in most animal models of SCI. We have transplanted OECs from the lamina propria (LP) of mice expressing green fluorescent protein (GFP) in all cell types into immunosuppressed rats with cervical or lumbar dorsal root injuries. LP‐OECs were deposited into either the dorsal root ganglion (DRG), intact or injured dorsal roots, or the dorsal columns via the dorsal root entry zone (DREZ). LP‐OECs injected into the DRG or dorsal root migrated centripetally, and migration was more extensive in the injured root than in the intact root. These peripherally deposited OECs migrated within the PNS but did not cross the DREZ; similarly, large‐ or small‐caliber primary afferents were not seen to regenerate across the DREZ. LP‐OEC deposition into the dorsal columns via the DREZ resulted in a laminin‐rich injection track: due to the pipette trajectory, this track pierced the glia limitans at the DREZ. OECs migrated centrifugally through this track, but did not traverse the DREZ; axons entered the spinal cord via this track, but were not seen to reenter CNS tissue. We found a preferential association between CGRP‐positive small‐ to medium‐diameter afferents and OEC deposits in injured dorsal roots as well as within the spinal cord. In the cord, OEC deposition resulted in increased angiogenesis and altered astrocyte alignment. These data are the first to demonstrate interactions between sensory axons and peripherally– derived OECs following dorsal root injury. © 2004 Wiley‐Liss, Inc.
Increased NG2+ glial cell proliferation and oligodendrocyte generation in the hypomyelinating mutant shiverer
Authors: Bu Jie , Banki Ali , Wu Qian , Nishiyama Akiko 
Published: May 2004

AbstractGlial cells that express the NG2 proteoglycan (NG2+ cells) are considered to be oligodendrocyte progenitors (OPCs) in the central nervous system (CNS), based on their ability to give rise to mature oligodendrocytes in vitro. To understand how dysmyelinated conditions influence OPC proliferation and differentiation, we studied proliferation and differentiation of NG2+ OPCs in vivo in the shiverer mutant (shi), which do not form compact myelin due to a deletion in the myelin basic protein gene. Acute bromodeoxyuridine (BrdU) labeling studies revealed a 4‐ to 6‐fold increase in NG2+ cell proliferation in shi spinal cord between postnatal day18 (P18) and P60, and most BrdU+ cells were NG2+ after P18. The increased proliferation was accompanied by a 2‐fold increase in the number of OPCs and oligodendrocytes. Survival studies following a single injection of BrdU at P18 revealed a decline in the number of BrdU+/NG2+ cells with a concomitant increase in the number of BrdU+ oligodendrocytes over time, suggesting that the proliferated NG2+ cells had differentiated into oligodendrocytes. BrdU+ oligodendrocytes were generated over a longer period of time in shi spinal cord and persisted longer in shi than in wild type spinal cord. These findings suggest that new oligodendrocytes continue to be generated in the dysmyelinated shi spinal cord by enhanced proliferation and differentiation of NG2+ oligodendrocyte progenitor cells. © 2004 Wiley‐Liss, Inc.
Expression of T‐type calcium channel splice variants in human glioma
Authors: Latour Isabelle , Louw Deon F. , Beedle Aaron M. , Hamid Jawed , Sutherland Garnette R. , Zamponi Gerald W. 
Published: May 2004

AbstractIn humans, three isoforms of the T‐type (Cav3.1) calcium‐channel α1 subunit have been reported as a result of alternate splicing of exons 25 and 26 in the III–IV linker region (Cav3.1a, Cav3.1b or Cav3.1bc). In the present study, we report that human glioma express Cav3.1 channels in situ, that splicing of these exons is uniquely regulated and that there is expression of a glioma‐specific novel T‐type variant (Cav3.1ac). Seven human glioma samples were collected at surgery, RNA was extracted, and cDNA was produced for RT‐PCR analysis. In addition, three glioma cell lines (U87, U563, and U251N), primary cultures of human fetal astrocytes, as well as adult and fetal human brain cDNA were used. Previously described Cav3.1 splice variants were present in glioma samples, cultured cells and whole brain. Consistent with the literature, our results reveal that in the normal adult brain, Cav3.1a transcripts predominate, while Cav3.1b is mostly fetal‐specific. RT‐PCR results on glioma and glioma cell lines showed that Cav3.1 expression in tumor cells resemble fetal brain expression pattern as Cav3.1bc is predominantly expressed. In addition, we identified a novel splice variant, Cav3.1ac, expressed in three glioma biopsies and one glioma cell line, but not in normal brain or fetal astrocytes. Transient expression of this variant demonstrates that Cav3.1ac displays similar current‐voltage and steady‐state inactivation properties compared with Cav3.1b, but a slower recovery from inactivation. Taken together, our data suggest glioma‐specific Cav3.1 gene regulation, which could possibly contribute to tumor pathogenesis. © 2004 Wiley‐Liss, Inc.
Cognitive impairment and associated risk factors among aged community members
Authors: Yen Yung‐Chieh , Yang Ming‐Jen , Shih Chun‐Hua , Lung For‐Wey 
Published: May 2004

AbstractObjectiveThe objective of this paper is to investigate the prevalence of and risk factors associated with cognitive impairment in a community‐dwelling elderly population.Methods1000 community residents aged 65–74 years were recruited in the cross‐sectional survey of associated factors of cognitive impairment in southern Taiwan. We employed a multilevel stratified sampling strategy and conducted this interview survey from April to June 2001. The survey questionnaire included background information and the Short Portable Mental Status Questionnaire. The relationship between cognitive impairment and each individual variable in personal attributes and social participation were explored.ResultsEight hundred and ninety‐four (89.4%) subjects completed the interview and questionnaires. The cognitive impairment rate among all subjects was 4.92%. Of those surveyed, 54.98% were male and 45.02% were female, and the average age was 69.37 (SD 2.73) years. Most survey respondents (72.05%) were married, and 68.90% of the subjects did not participate in any social activities in the last 6 months. Females, those who were illiterate or did not attend school, those who had an average family income below US$860 per month, and persons who did not participate in any social activities had a significantly higher rate of cognitive impairment.ConclusionThe educational level and participation in social activities were associated with the cognitive impairment among the aged community dwellers. Copyright © 2004 John Wiley & Sons, Ltd.
Solvothermal Morphology Studies: Alkali and Alkaline Earth Molybdates
Authors: Michailovski Alexej , Krumeich Frank , Patzke Greta R. 
Published: May 2004

AbstractA convenient and systematic solvothermal pathway towards alkali and alkaline‐earth molybdates has been established. The solvothermal treatment of a molybdenum‐based precursor material (yellow molybdic acid, MoO3⋅2 H2O) with ionic additives (alkali or alkaline‐earth halides) provides access to a spectrum of molybdates. Their particle morphology can further be addressed by optimizing the reaction conditions. The resulting products cover a wide scope of sizes and morphologies, ranging from molybdenum oxide fibres with high aspect ratios and nanoscale diameters to millimeter‐sized crystals of novel alkali molybdates. Both anionic and cationic additives exhibit certain synthetic profiles that offer the perspective of turning this approach into a ‘toolbox’ for the tailoring of molybdate‐based materials.
New Antibacterial Diterpenes from Pseudopterogorgia elisabethae
Authors: Ata Athar , Win Hla Y. , Holt David , Holloway Paul , Segstro Edward P. , Jayatilake Gamini S. 
Published: May 2004

AbstractFrom the MeOH extract of Pseudopterogorgia elisabethae, collected from the Bahamas, four new diterpenes, elisabethin E (1), elisabethin F (2), pseudopterosin P (3), and pseudopterosin Q (4), were isolated and their structures established with the aid of extensive spectroscopic studies. Compounds 3 and 4 showed antibacterial activity selectively against the Gram‐positive bacteria Streptococcus pyogenes, Staphylococcus aureus, and Enterococcus faecalis.
Cholinesterase‐Inhibiting New Steroidal Alkaloids from Sarcococca hookeriana of Nepalese Origin
Authors: Choudhary M. Iqbal , Devkota Krishna Prasad , Nawaz Sarfraz Ahmad , Shaheen Farzana , Atta‐ur‐Rahman  
Published: May 2004

AbstractBioassay‐guided phytochemical investigation of Sarcococca hookeriana has resulted in the isolation and structure elucidation of five new pregnane‐type steroidal alkaloids: (−)‐hookerianamide A (=(2β,3β,4β,20S)‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5α‐pregn‐16‐ene‐2,4‐diol; 1), (+)‐hookerianamide B (=(2α,3β,4β,20S)‐4‐acetoxy‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5α‐pregnan‐2‐ol; 2), (−)‐hookerianamide C (=(2β,3β,20S)‐2‐acetoxy‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5α‐pregnane; 3), (−)‐hookerianamine A (=(3β,20S)‐20‐(dimethylamino)‐3‐(methylamino)‐5α‐pregn‐14‐ene; 4), and (+)‐phulchowkiamide A (=(3β,20S)‐20‐(methylamino)‐3‐[(2‐methylbut‐2‐enoyl)amino]‐5α‐pregn‐2‐en‐4‐one; 5). These compounds, as well as the two chemically derived acetyl derivatives 6 and 7, displayed cholinesterase inhibition in a concentration‐dependent manner.
Foetidissimosides C–F, Novel Glycosides from the Roots of Cucurbita foetidissima
Authors: Gaidi Ghezala , Miyamoto Tomofumi , Lerche Holger , Lacaille‐Dubois Marie‐Aleth 
Published: May 2004

AbstractTwo novel echinocystic acid (=(3β,16α)‐3,16‐dihydroxyolean‐12‐en‐28‐oic acid) glycosides, foetidissimosides C (1), and D (2), along with new cucurbitane glycosides, i.e., foetidissimosides E/F (3/4) as an 1 : 1 mixture of the (24R)/(24S) epimers, were obtained from the roots of Cucurbita foetidissima. Their structures were elucidated by means of a combination of homo‐ and heteronuclear 2D‐NMR techniques (COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC), and by FAB‐MS. The new compounds were characterized as (3β,16α)‐28‐{[O‐β‐D‐glucopyranosyl‐(1→3)‐O‐β‐D‐xylopyranosyl‐(1→4)‐O‐6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐α‐L‐arabinopyranosyl]oxy}‐16‐hydroxy‐28‐oxoolean ‐12‐en‐3‐yl β‐D‐glucopyranosiduronic acid (1), (3β,16α)‐16‐hydroxy‐28‐oxo‐28‐{{O‐β‐D‐xylopyranosyl‐(1→3)‐O‐[β‐D‐xylopyranosyl‐(1→4)]‐O‐6‐deoxy‐α‐L‐mannopyranosyl‐(1→2)‐α‐L‐arabinopyranosyl}oxy}olean‐12‐en‐3‐yl β‐D‐glucopyranosiduronic acid (2), and (3β,9β,10α,11α,24R)‐ and (3β,9β,10α,11α,24S)‐25‐(β‐D‐glucopyranosyloxy)‐9‐methyl‐19‐norlanost‐5‐en‐3‐yl 2‐O‐β‐D‐glucopyranosyl‐β‐D‐glucopyranoside (3 and 4, resp.).
Steroidal Saponins from Disporopsis pernyi
Authors: Yang Qing‐Xiong , Xu Min , Zhang Ying‐Jun , Li Hai‐Zhou , Yang Chong‐Ren 
Published: May 2004

AbstractFour new steroidal saponins, named disporosides A–D (1–4), corresponding to (3β,25R)‐3‐[(β‐D‐glucopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐glucopyranosyl)oxy]‐5β‐spirostan (1), (3β,25R)‐3‐[(β‐D‐glucopyranosyl‐(1→2)‐[6‐O‐hexadecanoyl‐β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐glucopyranosyl)oxy]‐5β‐spirostan (2), (3β,22R,25R)‐26‐[(β‐D‐glucopyranosyl)oxy]‐3‐[(β‐D‐glucopyranosyl‐(1→2)‐β‐D‐glucopyranosyl)oxy]‐5β‐furostan (3), and (3β,22R,25R)‐26‐[(β‐D‐glucopyranosyl)oxy]‐3‐[(β‐D‐glucopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→6)]‐β‐D‐glucopyranosyl)oxy]‐5β‐furostan (4), have been isolated from the fresh rhizomes of Disporopsis pernyi, together with the three known compounds Ys‐I, agavoside B, and (3β,25R)‐3‐[(β‐D‐xylopyranosyl‐(1→3)‐β‐D‐glucopyranosyl‐(1→4)‐β‐D‐galactopyranosyl)oxy]‐5α‐spirostan‐12‐one. Their structures were elucidated by spectroscopic analyses, chemical transformations (acid hydrolysis), and comparison with literature data.
Measurement, scaling, and topographic analyses of spatial crop yield and soil water content
Authors: Green Timothy R. , Erskine Robert H. 
Published: May 2004

AbstractThe need to transfer information across a range of space–time scales (i.e. scaling) is coupled with the need to predict variables and processes of interest across landscapes (i.e. distributed simulation). Agricultural landscapes offer a unique set of problems and space–time data availability with the onset of satellite‐based positioning and crop yield monitoring. The present study addresses quantification of the spatial variability of rainfed crop yield and near‐surface soil water at farm field scales using two general methods: (1) geostatistical and fractal analyses; and (2) univariate linear regression using topographic attributes as explanatory variables. These methods are applied to 2 years of crop yield data from three fields in eastern Colorado, USA, and to soil‐water content (depth‐averaged over the top 30 cm) in one of these fields. Method 1 is useful for scaling each variable, and variogram shapes and their associated fractal dimensions of crop yield are related to those of topographic attributes. A new measure of fractal anisotropy is introduced and estimated from field data. Method 2 takes advantage of empirical and process knowledge of topographic controls on water movement and microenvironments. Topographic attributes, estimated from a digital elevation model at some scale (10 m by 10 m spacing here), help explain the spatial variability in crop yield. The topographic wetness index, for example, explained from 38 to 48% of the spatial variance in 1997 wheat yield. Soil water displays more random spatial variability, and its dynamic nature makes it difficult to predict in both space and time. Despite such variability, spatial structure is evident and can be approximated by simple fractals out to lag distances of about 450 m. In summary, these data and spatial analyses provide a basis and motivation for estimating the fractal behaviour, spatial statistics, and distributed patterns of crop yield from landscape topographic information. Copyright © 2004 John Wiley & Sons, Ltd.
A general test for time dependence in parameters
Authors: Becker Ralf , Enders Walter , Hurn Stan 
Published: May 2004

AbstractA new test for time‐dependent parameters is proposed. The Trig‐test is based on a trigonometric expansion to approximate the unknown functional form of the variation in the parameters concerned. It is shown to have the correct empirical size and excellent power to detect structural breaks and stochastic parameter variation. The appropriate use of the Trig‐test is demonstrated by testing for structural breaks in the US inflation rate. The test detects a statistically significant increase in the US inflation rate beginning in the early 1970s and lasting through to the early 1980s. Copyright © 2004 John Wiley & Sons, Ltd.
The effects of subjective survival on retirement and Social Security claiming
Authors: Hurd Michael D. , Smith James P. , Zissimopoulos Julie M. 
Published: May 2004

AbstractAccording to the life‐cycle model, mortality risk will influence both retirement and the desire to annuitize wealth. We estimate the effect of subjective survival probabilities on retirement and on the claiming of Social Security benefits because delayed claiming is equivalent to the purchase of additional Social Security annuities. We find that those with very low subjective probabilities of survival retire earlier and claim earlier than those with higher subjective probabilities, but the effects are not large. The great majority of workers claim as soon as they are eligible. Copyright © 2004 John Wiley & Sons, Ltd.
Technical note: A toy as tool: A low‐cost image analysis system for the evaluation of tumor size in experimental small animal models
Authors: Brockmann Marc Alexander , Ulmer Stephan , Lamszus Katrin , Giese Alf , Petersen Dirk 
Published: May 2004

AbstractImage analysis systems are an essential tool in measurements of size of intraparenchymal tumors or lesions in experimental small animal models. Conventional image analysis systems are relatively expensive. We therefore compared the performance of a professional image analysis system with an inexpensive setup by evaluating tumor size in an orthotopic glioma mouse model. The maximum cross‐sectional tumor area of H&E stained brain‐slides of two groups of mice (treatment and control group) was measured by two independent investigators using a professional image analysis system (Leica DM IRB microscope) with the Leica Quantimet 500c software, and a low‐cost‐system (Intel QX3 microscope) with a non‐commercial image analysis software. Mean tumor volumes were calculated and the results from each of the image analysis systems, investigators, and treatment effects were compared. The tumor volumes as measured with the low‐cost and the professional system differed between −3.7 and +7.5% (P = 0.69–0.99). Measurements made by investigator A and B differed between −7.0 and +3.9% (P = 0.69–0.88). Treatment in all cases significantly reduced the tumor volume between 58.4 and 62.7% (P = 0.0002 or 0.0003), regardless of the investigator or the used image analysis system. We therefore conclude that the QX3 low‐cost microscope in combination with a non‐commercial image‐analysis software represents an inexpensive solution to reliably analyze the size of regions of interest, if they provide a sufficient contrast. However, the low‐cost setup due to its low resolution definitely limits a detailed analysis of histologic features. Microsc. Res. Tech. 63:306–309, 2004. © 2004 Wiley‐Liss, Inc.
Electron energy loss spectroscopy for analysis of inhaled ultrafine particles in rat lungs
Authors: Kapp Nadine , Kreyling Wolfgang , Schulz Holger , Hof Vinzenz Im , Gehr Peter , Semmler Manuela , Geiser Marianne 
Published: May 2004

AbstractEpidemiologic studies have associated cardiovascular morbidity and mortality with ambient particulate air pollution. Particles smaller than 100 nm in diameter (ultrafine particles) are present in the urban atmosphere in very high numbers yet at very low mass concentration. Organs beyond the lungs are considered as targets for inhaled ultrafine particles, whereby the route of particle translocation deeper into the lungs is unclear. Five rats were exposed to aerosols of ultrafine titanium dioxide particles of a count median diameter of 22 nm (geometric standard deviation, GSD 1.7) for 1 hour. The lungs were fixed by intravascular perfusion of fixatives immediately thereafter. TiO2 particles in probes of the aerosol as well as in systematic tissue samples were analyzed with a LEO 912 transmission electron microscope equipped with an energy filter for elemental microanalysis. The characteristic energy loss spectra were obtained by fast spectrum acquisition. Aerosol particles as well as those in the lung tissue were unambiguously identified by electron energy loss spectroscopy. Particles were mainly found as small clusters with a rounded shape. Seven percent of the particles in the lung tissue had a needle‐like shape. The size distribution of the cluster profiles in the tissue had a count median diameter of 29 nm (GSD 1.7), which indicates no severe clustering or reshaping of the originally inhaled particles. Electron energy loss spectroscopy and related analytical methods were found to be suitable to identify and localize ultrafine titanium dioxide particles within chemically fixed and resin‐embedded lung tissue. Microsc. Res. Tech. 63:298–305, 2004. © 2004 Wiley‐Liss, Inc.
Bipartite anti‐Ramsey numbers of cycles
Authors: Axenovich Maria , Jiang Tao , Kündgen André 
Published: May 2004

AbstractWe determine the maximum number of colors in a coloring of the edges of Km,n such that every cycle of length 2k contains at least two edges of the same color. One of our main tools is a result on generalized path covers in balanced bipartite graphs. For positive integers q≤ a, let g(a,q) be the maximum number of edges in a spanning subgraph G of Ka,a such that the minimum number of vertex‐disjoint even paths and pairs of vertices from distinct partite sets needed to cover V(G) is q. We prove that g(a,q) = a2 − aq + max {a, 2q − 2}. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 9–28, 2004
Pelvic exenteration and sphincter preservation: An analysis of 96 cases
Authors: Oliveira Poletto Antonio Henrique , Lopes Ademar , Carvalho André Lopes , Ribeiro Edson Augusto , da Costa Vieira René Aloísio , Rossi Benedito Mauro , Aguiar Samuel , Guimarães Gustavo Cardoso , Ferreira Fabio de Oliveira , Nakagawa Wilson Toshihiko 
Published: May 2004

AbstractBackgroundPelvic exenteration (PE) is characterized by its technical complexity and morbidity rate. Appropriate patient selection prior to the operation allows for more conservative surgeries, preserving sphincters, and continent reconstruction of the intestinal and urinary tract, contributing to better results.MethodsBetween 1980 and 2000, 96 PE were performed. Factors related to sphincter preservation as well as factors associated to prognosis were respectively analyzed.ResultsOf the 96 PE, at least one sphincter in 36 patients was preserved (37.5%). In the 1990s, the sphincter preservation rate was significantly higher than in the 1980s (47.6 vs. 18.2%) (P = 0.005). More serious complications happened in 19.8% of the patients and the post‐operative mortality rate was 15.6%. The post‐operative complication rate was not influenced by sphincter preservation (P = 0.276). In nine patients, the resection margins were compromised microscopically (R1) and in five patients, there were macroscopically compromised (R2). The resection margins were not influenced by the type of surgery (P = 0.104), nor by the preservation of sphincters (P = 0.881). Twenty‐three patients experienced relapses, 13 being local, eight distant, and two local and distant. Disease free survival at 5 years was 40.5%, and the primary site of the tumor was a factor associated to differences in disease free survival (P = 0.027). Overall 5‐year survival was 41.9% and was significantly associated to the number of organs compromised (P = 0.040) and sphincter preservation (P = 0.026). Patients who were submitted to R0 type resection had a median survival of 40.9 months, while R1 and R2 type resections had a median 21.2 month survival.ConclusionsThe appropriate pre‐operative selection of the patient and rigorous oncological criteria permit PE to be performed while preserving the sphincters in selected cases, without harming survival rates. J. Surg. Oncol. 2004;86:122–127. © 2004 Wiley‐Liss, Inc.