bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive endocrinology of wild female Chimpanzees (Pan troglodytes schweinfurthii): methodological considerations and the role of hormones in sex and conception
Authors: Emery Thompson Melissa 
Published: September 2005

AbstractFecal and urine samples were collected from 81 female East African chimpanzees (Pan troglodytes schweinfurthii) in three major study populations in Gombe National Park, Tanzania, and Budongo Forest Reserve and Kibale National Park, Uganda. In this study I evaluated issues related to sample storage and assay reliability, and used these methods to investigate the significance of ovarian hormone levels in terms of conception success and sexual behavior. Drying of feces proved to be an effective technique and resulted in hormonal concentrations that were significantly correlated with concentrations in frozen feces. Estimates of ovarian steroid production based on urine and fecal sampling were significantly correlated with each other. The ovarian cycle profiles obtained, which were aligned relative to sexual swelling detumescence, corroborate previous findings in wild west African chimpanzees [Deschner et al., Animal Behaviour 66:551–560, 2003] in suggesting that the fertile period is limited to the last week of tumescence, but that ovulatory timing is not as precise as previously thought. A comparison across cycles confirmed the hypothesis that higher ovarian steroid levels are associated with an increased probability of conception. Females that did conceive with relatively low hormone levels had poor reproductive outcomes. Sexual behavior was tied to the probability of conception both within and across cycles. Copulatory activity within cycles closely followed the estrogen profile and was timed to coincide, on average, with the peak fertile period of females. Further, rates of copulation were significantly higher during the fertile periods of cycles that led to conception than those that did not. Am. J. Primatol. 67:137–158, 2005. © 2005 Wiley‐Liss, Inc.
Fecal steroid research in the field and laboratory: improved methods for storage, transport, processing, and analysis
Authors: Ziegler Toni E. , Wittwer Daniel J. 
Published: September 2005

AbstractSince the pioneering paper “Measurement of Excreted Steroids in Macaca nemestrina” [Risler et al., American Journal of Primatology 12:91–100, 1987] was first published, field primatologists have been using fecal extraction techniques to examine adrenal and gonadal hormones. These techniques have allowed investigators to determine reproductive conditions in wild primates without causing any disruption to the populations. Over the years, many techniques have been developed to improve the ease of analysis, transportation, and purification. More of the processing can now be done in the field. This paper describes the methodology developed or adapted at the Wisconsin National Primate Research Center, and the factors involved in preparing fecal samples for steroid analysis. We provide information on the steps involved in extracting and purifying steroids from feces for measurement. The latest methods include field processing of samples, such as drying collected material or separating steroids from the fecal material by solid phase extraction (SPE). How samples are processed in the field determines the requirements for international transportation and the methods used in the laboratory. The pros and cons of the different processing methods are discussed. We also report on recent advances in laboratory quantification, with implications for steroid isolation prior to analysis. The different processes involved in isolating and measuring fecal steroids discussed here will enable investigators to understand the components necessary to ensure accurate and reliable results. Am. J. Primatol. 67:159–174, 2005. © 2005 John Wiley & Sons, Ltd.
High‐performance liquid chromatography method development and validation for simultaneous determination of five model compounds, antipyrine, metoprolol, ketoprofen, furosemide and phenol red, as a tool for the standardization of rat in situ intestinal permeability studies using timed wavelength detection
Authors: Chawla Sonia , Ghosh Soma , Sihorkar Vaibhav , Nellore Ranjani , Kumar T. R. Shantha , Srinivas Nuggehally R. 
Published: September 2005

AbstractA simple, precise, accurate and rugged reversed‐phase high‐performance liquid chromatography (HPLC) method has been developed and validated for the simultaneous determination of five permeability model compounds, viz. antipyrine, metoprolol, ketoprofen, furosemide and phenol red. The method was intended to standardize rat in situ single‐pass intestinal perfusion studies to assess the intestinal permeability of drugs in the market as well as new chemical entities. Optimum resolution was achieved by gradient elution on a Symmetry Shield C‐18 analytical column with the mobile phase consisting of a mixture of aqueous potassium dihydrogen orthophosphate (pH 5.5; 0.01 m) and methanol at a flow rate of 1.5 mL/min. The retention times of antipyrine, metoprolol, ketoprofen, phenol red and furosemide were about 9, 12, 13, 16 and 17 min, respectively. Data acquisition was carried out using a photo diode array detector in the wavelength range 210–600 nm. Extraction of chromatograms was carried out by timed wavelength. Data obtained in all studies indicated that the method was suitable for the intended purpose. The validated method was found to be linear and precise in the working range. Suitability of storage under various conditions and freeze/thaw impact at cold temperature were established to ensure complete sample recovery without any stability issues. Recovery very close to the spiked amounts indicated that the method was highly accurate and suitable for use on routine basis. Copyright © 2005 John Wiley & Sons, Ltd.
High‐performance liquid chromatographic method for simultaneous quantification of eight major biologically active ingredients in ‘Da‐Chai‐Hu‐Tang’ Preparation
Authors: Li Chia‐Ying , Chiu Chiung‐Hui , Huang Ho‐Shin , Lin Chung‐Hua , Wu Tian‐Shung 
Published: September 2005

AbstractA simple, sensitive and specific high‐performance liquid chromatographic method has been developed for the first time to simultaneously determine the eight major biologically active ingredients, namely paeoniflorin, naringin, sennoside A, baicalin, baicalein, saikosaponin a, rhein and emodin of the Chinese herbal formula Da‐Chai‐Hu‐Tang. The contents of these marker substances in Da‐Chai‐Hu‐Tang extract could be easily determined within 85 min. The assay was reproducible and accurate with overall intra‐day variations and accuracy of less than 2% and more than 97.9%, respectively. Results indicate that the developed HPLC assay can be successfully utilized as a quality control method for simultaneous determination of eight representative substances in Da‐Chai‐Hu‐Tang. Copyright © 2005 John Wiley & Sons, Ltd.
Ultra high‐speed sorting
Authors: Leary James F. 
Published: September 2005

AbstractBackgroundCell sorting has a history dating back approximately 40 years. The main limitation has been that, although flow cytometry is a science, cell sorting has been an art during most of this time. Recent advances in assisting technologies have helped to decrease the amount of expertise necessary to perform sorting.MethodsDroplet‐based sorting is based on a controlled disturbance of a jet stream dependent on surface tension. Sorting yield and purity are highly dependent on stable jet break‐off position. System pressures and orifice diameters dictate the number of droplets per second, which is the sort rate limiting step because modern electronics can more than handle the higher cell signal processing rates.ResultsCell sorting still requires considerable expertise. Complex multicolor sorting also requires new and more sophisticated sort decisions, especially when cell subpopulations are rare and need to be extracted from background. High‐speed sorting continues to pose major problems in terms of biosafety due to the aerosols generated.ConclusionsCell sorting has become more stable and predictable and requires less expertise to operate. However, the problems of aerosol containment continue to make droplet‐based cell sorting problematical. Fluid physics and cell viability restraints pose practical limits for high‐speed sorting that have almost been reached. Over the next 5 years there may be advances in fluidic switching sorting in lab‐on‐a‐chip microfluidic systems that could not only solve the aerosol and viability problems but also make ultra high‐speed sorting possible and practical through massively parallel and exponential staging microfluidic architectures. © 2005 International Society for Analytical Cytology
Signal transduction of erbB receptors in trastuzumab (Herceptin) sensitive and resistant cell lines: Local stimulation using magnetic microspheres as assessed by quantitative digital microscopy
Authors: Friedländer Elza , Arndt‐Jovin Donna J. , Nagy Péter , Jovin Thomas M. , Szöllősi János , Vereb György 
Published: September 2005

AbstractBackgroundErbB2 (HER‐2), a member of the epidermal growth factor (EGF) receptor family, is a class I transmembrane receptor tyrosine kinase. Although erbB2 has no known physiologic ligand, it can form complexes with other members of the family and undergo transactivation of its very potent kinase activity, thereby initiating downstream signaling and cell proliferation. ErbB2 is a frequent pathologic marker in ductal invasive breast carcinomas and is targeted by using a specific humanized monoclonal antibody, trastuzumab (Herceptin). The antibody is effective in only 20% to 50% of erbB2‐positive tumors, and this resistance, as yet poorly understood, constitutes a major therapeutic challenge.MethodsMagnetic microspheres coated with ligands or antibodies are widely used for separation of proteins and cells and allow localized, high intensity, and precisely timed stimulation of cells. We used EGF‐ and trastuzumab‐covered paramagnetic microspheres, quantitative confocal laser scanning microscopy, and digital image processing to investigate the (trans)activation of and local signal propagation from erbB1 and erbB2 on trastuzumab sensitive and resistant carcinoma cell lines expressing these receptors at high levels.ResultsOn A431 cells expressing high levels of endogenous erbB1 and transfected erbB2‐mYFP (A4‐erbB2‐mYFP F4 cell line), EGF‐coupled‐microspheres activated erbB1 and transactivated erbB2‐mYFP. In two other cell lines with comparable erbB2 expression but lower levels of erbB1, EGF microspheres transactivated erbB2 less efficiently. Trastuzumab in solution activated erbB2 on A4‐erbB2‐mYFP and the trastuzumab sensitive SKBR‐3 cells, but only negligibly on the resistant JIMT‐1 cells that showed a 10 times higher Kd for the antibody. Nevertheless, pronounced erbB2 activation and tyrosine phosphorylation could be detected after stimulation with trastuzumab‐coupled microspheres in all cell lines, although transactivation of erbB1 was negligible. Receptor phosphorylation was restricted to the immediate proximity of the microspheres, i.e., receptor clusters external to these locations remained inactive.ConclusionErbB1 ligand and erbB2 specific antibody attached to magnetic microspheres are efficient tools in assessing erbB activation, localized signal propagation, and erbB heterodimer formation. Trastuzumab coupled to microspheres is more efficient at accessing erbB2 and activating it than trastuzumab in solution. © 2005 International Society for Analytical Cytology
Computer program for analyzing donor photobleaching FRET image series
Authors: Szentesi Gergely , Vereb György , Horváth Gábor , Bodnár Andrea , Fábián Ákos , Matkó János , Gáspár Rezső , Damjanovich Sándor , Mátyus László , Jenei Attila 
Published: September 2005

AbstractBackgroundThe photobleaching fluorescence resonance energy transfer (pbFRET) technique is a spectroscopic method to measure proximity relations between fluorescently labeled macromolecules using digital imaging microscopy. To calculate the energy transfer values one has to determine the bleaching time constants in pixel‐by‐pixel fashion from the image series recorded on the donor‐only and donor and acceptor double‐labeled samples. Because of the large number of pixels and the time‐consuming calculations, this procedure should be assisted by powerful image data processing software. There is no commercially available software that is able to fulfill these requirements.MethodsNew evaluation software was developed to analyze pbFRET data for Windows platform in National Instrument LabVIEW 6.1. This development environment contains a mathematical virtual instrument package, in which the Levenberg‐Marquardt routine is also included. As a reference experiment, FRET efficiency between the two chains (β2‐microglobulin and heavy chain) of major histocompatibility complex (MHC) class I glycoproteins and FRET between MHC I and MHC II molecules were determined in the plasma membrane of JY, human B lymphoma cells.ResultsThe bleaching time constants calculated on pixel‐by‐pixel basis can be displayed as a color‐coded map or as a histogram from raw image format.ConclusionIn this report we introduce a new version of pbFRET analysis and data processing software that is able to generate a full analysis pattern of donor photobleaching image series under various conditions. © 2005 International Society for Analytical Cytology
Biological microbeads for flow‐cytometric immunoassays, enzyme titrations, and quantitative PCR
Authors: Pataki Judit , Szabó Miklós , Lantos Erika , Székvölgyi Lóránt , Molnár Mónika , Hegedüs Éva , Bacsó Zsolt , Kappelmayer János , Lustyik György , Szabó Gábor 
Published: September 2005

AbstractBackgroundIntroduction of microbeads into flow‐cytometry has created a new scenario, making quantitative measurement of molecules dispersed in a homogeneous phase, with an extremely wide realm of already realized and potential applications possible. Development of this field has lead to specialized instrumentation and microbead arrays, dedicated to certain applications.MethodsFormaldehyde‐fixed yeast and bacterial cells were conjugated with avidin and applied as microbeads, to establish a simple, convenient, flexible, and inexpensive flow‐cytometric platform for various immunological and biochemical assays.ResultsWe have tested these “biological microbeads” for the simultaneous titration of human α‐fetoprotein (AFP) and human Chorionic Gonadotropin (βhCG) hormone levels, for the titration of proteolytic and nucleolytic (restriction) enzymes, and for quantitative PCR, using biotinylated and fluorescent primers.ConclusionsThe use of biological microbeads for various immunological and biochemical assays has been demonstrated. The flow‐cytometric methods proved to be at least as sensitive as the standard biochemical or immunological tests. For proteinase K activity measurements, a single enzyme molecule in the sample could be detected. The sensitivity, versatility, and low cost of the assays may advance flow‐cytometry to become a central methodological platform in most laboratories. The biological microbeads offer virtually unlimited possibilities for fluorescent labeling (addressing), conjugation of ligand binding molecules, and they are easy to handle and perform well in a multiplex format. © 2005 International Society for Analytical Cytology
Suppression of eosinophilic airway inflammation by treatment with α‐galactosylceramide
Authors: Morishima Yuko , Ishii Yukio , Kimura Toru , Shibuya Akira , Shibuya Kazuko , Hegab Ahmed E. , Iizuka Takashi , Kiwamoto Takumi , Matsuno Yosuke , Sakamoto Tohru , Nomura Akihiro , Taniguchi Masaru , Sekizawa Kiyohisa 
Published: September 2005

AbstractTo clarify the essential role of NKT cells in allergy, we investigated the contribution of NKT cells to the pathogenesis of eosinophilic airway inflammation using α‐galactosylceramide (α‐GalCer), a selective ligand for NKT cells. Although continuous administration of α‐GalCer during ovalbumin (OVA) sensitization increased OVA‐specific IgE levels and worsened eosinophil inflammation, a single administration of α‐GalCer at the time of OVA challenge completely prevented eosinophilic infiltration in wild‐type mice. This inhibitory effect of α‐GalCer was associated with a decrease in airway hyperresponsiveness, an increase in IFN‐γ, and decreases in IL‐4, IL‐5 and IL‐13 levels in the bronchoalveolar lavage fluids. Analysis of lung lymphocytes revealed that production of IFN‐γ increased in NK cells, but not in T or NKT cells, following α‐GalCer administration. Induction of vascular cell adhesion molecule‐1 in the lungs of wild‐type mice was also significantly attenuated by treatment with α‐GalCer. These effects of α‐GalCer were abrogated in Jα281–/– mice, which lack NKT cells, and in wild‐type mice treated with anti‐IFN‐γ Ab. Hence, our data indicate that α‐GalCer suppresses allergen‐induced eosinophilic airway inflammation, possibly by inducing a Th1 bias that results in inhibition of eosinophil adhesion to the lung vessels.See accompanying commentary: http://dx.doi.org/10.1002/eji.200535425
Help signals provided by lymphokines modulate the activation and apoptotic programs induced by partially agonistic peptides in specific cytotoxic T lymphocytes
Authors: Uhlin Michael , Sandalova Elena , Masucci Maria Gracia , Levitsky Victor 
Published: September 2005

AbstractInefficient recognition of altered peptide ligands (APL) by specific CTL is believed to contribute to the failure of immune control over tumors and progressive viral infections. A link between deficient help signals and the appearance of CTL epitope mutants has been suggested by recent studies. However, the regulation of APL activity by immunologic help is not well understood. We analyzed the capacity of exogenous IL‐2 and IL‐15, which are physiologically produced by cells of the adaptive and innate immune system, respectively, to modulate proliferation, responsiveness to repeated stimulation and apoptotic programs triggered in specific CTL by either fully or partially agonistic peptide ligands. We show that signals induced by the lymphokines synergize with weak TCR signaling induced by partially agonistic APL, converting many of these peptides from inhibitory to stimulatory ligands. Some APL partially suppress the responsiveness of specific CTL to secondary stimulation, while this inhibitory effect is diminished if APL‐stimulated cells are cultured in the presence of either of the lymphokines. We also demonstrate that IL‐2 and IL‐15 suppress up‐regulation of the Bcl‐2 family member Bim and induction of a death receptor‐independent apoptotic program triggered by partially agonistic APL. Our results suggest that under conditions of insufficient immunologic help, partially agonistic APL may actively suppress specific CTL responses and become especially advantageous for immune escape of tumors or viruses.
In situ measurements of sediment settling characteristics in ﬂoodplains using a LISST‐ST
Authors: Thonon Ivo , Roberti Johannes R. , Middelkoop Hans , van der Perk Marcel , Burrough Peter A. 
Published: September 2005

AbstractDue to a lack of data on settling velocities (ws) and grain size distributions (GSDs) in ﬂoodplain environments, sedimentation models often use calibrated rather than measured parameters. Since the characteristics of suspended matter differ from those of deposited sediment, it is impossible to derive the ws and GSD from the latter. Therefore, one needs to measure in situ suspended sediment concentrations (SSCs), settling velocities, effective grain sizes and sedimentation ﬂuxes. For this purpose we used the LISST‐ST, a laser particle sizer combined with a settling tube.In 2002 (twice) and 2004, we located the LISST‐ST with an optical backscatter sensor and sediment traps in two ﬂoodplains in The Netherlands: one along the unembanked IJssel River, another along the embanked Waal River. Measurements revealed that the SSC in the ﬂoodplains varied in relation to the SSC in the river channel. Smaller ﬂocs dominated the SSC, while larger ﬂocs dominated the potential sedimentation ﬂuxes. The in situ GSD in the IJssel ﬂoodplain was signiﬁcantly coarser than in the Waal ﬂoodplain, while the dispersed median grain sizes were equal for both ﬂoodplains. Therefore, the dispersed median grain size was two to ﬁve times smaller than the effective one.The in situ grain size exhibited a signiﬁcant positive relationship with ws, although the ws for the largest ﬂocs showed high variability. Consequently, the variability in sedimentation ﬂuxes was also large. In the actual sedimentation ﬂuxes, and hence in sedimentation models, in situ grain sizes up to about 20 µm can be neglected. In ﬂoodplain sedimentation models the relation between settling velocity and in situ grain size can be used instead of Stokes's law, which is only valid for dispersed grain sizes. These models should also use adequate data on ﬂow conditions as input, since these strongly inﬂuence the suspended sediment characteristics. Copyright © 2005 John Wiley & Sons, Ltd.
Location, location, location: The role of cyclin D1 nuclear localization in cancer
Authors: Gladden Andrew B. , Diehl J. Alan 
Published: September 2005

AbstractThe control of cell proliferation is crucial in maintaining cellular homeostasis and loss of this mechanism is a principle hallmark of cancer cells. A primary target of growth factor signaling is the cyclin D1‐dependent kinase (D1‐CDK4/6) whose activity promotes G1 phase progression by phosphorylating the retinoblastoma protein (Rb) along with related pocket proteins 107 and p130, relieving inhibition of E2F family transcription factors. Cyclin D1 accumulation is regulated at multiple levels including transcription, post‐translational activation and cellular localization throughout the cell cycle. While overexpression of cyclin D1 has been observed in a number of human cancers, mouse cancer models overexpressing D1 have fallen short of establishing a role for cyclin D1 in the initiation of malignant phenotypes suggesting an additional regulatory mechanism exists that prevents cyclin D1‐driven cancer. This article will present an overview of current data investigating the regulation of cyclin D1 nuclear localization and the prevalence of these aberrations in cancer. Finally, future avenues of research involving cyclin D1 cellular localization and its regulation in cancer will be addressed. J. Cell. Biochem. © 2005 Wiley‐Liss, Inc.
Phylogenetic patterns of enamel microstructure in dinosaur teeth
Authors: Hwang Sunny H. 
Published: September 2005

AbstractThe tooth enamel microstructure of all the dinosaur taxa that are adequately represented in the American Museum of Natural History collections were analyzed using scanning electron microscopy. This study aims to determine whether or not better sampling within a major nonmammalian amniote (hereafter referred to descriptively as “reptile”) clade will unearth phylogenetic patterns in enamel microstructure in addition to those dictated by tooth function. While interest in reptile enamel microstructure has increased in the past few years, intensive sampling focused on just one monophyletic reptile clade was not previously implemented. This study reveals that phylogenetic constraints play a larger role in shaping enamel microstructure in reptiles than previously thought. Within many monophyletic dinosaur clades the combination of enamel types and enamel features within a tooth—the schmelzmuster—is the same in all the taxa due to their common ancestry, and their schmelzmusters are diagnostic of their respective clades. While distantly related taxa with similar teeth and diets have similar schmelzmusters due to functional constraints, phylogenetic constraints keep those schmelzmusters distinct from one another. An interesting finding of this analysis is that the enamel complexity of a taxon does not necessarily coincide with the position of the taxon on a phylogenetic tree; more derived taxa do not necessarily have more derived enamel and more primitive taxa do not necessarily have more primitive enamel. J. Morphol. © 2005 Wiley‐Liss, Inc.