bluuebunny/crossref_metadata_2025_split huggingface dataset:
An application of mathematical morphology to analysis of the size and shape of nuclei in tissue sections of non‐Hodgkin's lymphoma
Authors: Lesty C. , Raphael M. , Nonnenmacher L. , Leblond‐Missenard V. , Delcourt A. , Homond A. , Binet J. L. 
Published: August 2005

AbstractUsing principles from the theory of mathematical morphology, a semiautomatic analysis of the size and shape of cell nuclei on tissue sections was carried out on a Leitz Texture Analysis System (Leitz‐TAS). The four parameters proposed here are more discriminatory than conventional shape evaluation by the form factor (FF), which is based on the ratio of perimeter squared to area. The parameters quantified, respectively, nuclear elongation (ND), narrow (R1) and wide (R2) irregularities, and the distribution of R1 and R2 along the nuclear contour (ID). The properties of these parameters were tested nucleus‐by‐nucleus on 24 nuclear models.The methodology was then illustrated by a study of lymph node nuclei in non‐Hodgkin's lymphoma (NHL). Prior to analysis, 45 lymphomas were classified into five categories of nuclear size and shape according to the International Working Formulation (IWF). Two hundred nuclei were measured on each lymph node section. Statistical interpretation was based upon an analysis of the nuclear surface area on sections and upon the mean values of R1, R2, and ND, the standard deviations of R1 and R2, and the percentage of cleaved nuclei detected by ID. The mean value of R2 discriminated best between the two sets of populations with regular and irregular nuclear contours, respectively. Parameters R1, ND, and ID permitted the distinction of certain NHL cases among populations with irregular nuclei. Nuclear invaginations decreased in depth as the nuclear area became greater. The median surface area was well correlated to the IWF, and the skewness coefficient (third statistical moment of the nuclear surface area distribution) was related to the number of nuclear size or shape sub‐populations.
Flow cytometry analysis of recombinant Saccharomyces cerevisiae populations
Authors: Srienc Friedrich , Campbell Judith L. , Bailey James E. 
Published: August 2005

AbstractA new fluorescent stain has been developed for detecting cloned β‐galactosidase activity in individual cells of Saccharomyces cerevisiae by flow cytometry. The staining reaction is based on enzymatic cleavage of α‐naphthol‐β‐D‐galactopyranoside by intracellular β‐galactosidase and trapping of the liberated naphthol by hexazoniumpararosaniline yielding a fluorescent, insoluble end product. This stain, in connection with an appropriate host strain, has been applied for detecting plasmids encoding inducible β‐galactosidase in unstable recombinant cell populations carrying plasmids with different origins of replication. The method enables rapid determination of the fraction of plasmid‐containing cells as well as quantitation of intracellular β‐galactosidase content by kinetic enzyme assay. Inducibility of the marker enzyme is important for maintaining correlation between enzyme and gene content.
Flow cytometric DNA and cytogenetic studies in human tumors: A comparison and discussion of the differences in modal values obtained by the two methods
Authors: Tribukait B. , Granberg‐öhman I. , Wijkström H. 
Published: August 2005

AbstractThe numerical chromosome values in 53 human tumors were determined and compared with the modal DNA values as measured by flow cytometry. In tumors with chromosome counts in the diploid and tetraploid range, the modal DNA values were found to correspond to the modal values based on the chromosome counts. In tumors with chromosome counts in the triploid range, however, the modal DNA values were about 15% higher than expected.In order to explain this difference, the ratio between large and small chromosomes in the karyotyped metaphases was assessed. In addition, the DNA content of individual chromosomes, including markers and minutes, was calculated as a reflection of the DNA content of the whole cell. The ratio of large to small chromosomes did not deviate from the normal ratio found in cells with diploid, triploid, and tetraploid chromosome counts. Neither difficulties in karyotyping nor shortcomings in the flow cytometric methodology could be used to explain the discrepancy between the expected and empirical modal DNA values. Some of the chromosomes in triploid tumors may, therefore, contain an increased amount of DNA.
Count‐Dependent filter for smoothing bivariate FCM histograms
Authors: Schuette W. H. , Shackney S. E. , Marti G. E. 
Published: August 2005

AbstractA data‐smoothing filter has been developed that permits the improvement in accuracy of individual elements of a bivariate flow cytometry (FCM) histogram by making use of data from adjacent elements, a knowledge of the two‐dimensional measurement system point spread function (PSF), and the local count density.For FCM data, the PSF is assumed to be a set of two‐dimensional Gaussian functions with a constant coefficient of variation for each axis. A set of space variant smoothing kernels are developed from the basic PSF by adjusting the orthogonal standard deviations of each Gaussian smoothing kernel according to the local count density. This adjustment in kernel size matches the degree of smoothing to the local reliability of the data. When the count density is high, a small kernel is sufficient. When the density is low, however, a broader kernel should be used. The local count density is taken from a region defined by the measurement PSF.The smoothing algorithm permits the reduction in statistical fluctuations present in bivariate FCM histograms due to the low count densities often encountered in some elements. This reduction in high‐frequency spatial noise aids in the visual interpretation of the data. Additionally, by making more efficient use of smaller samples, systematic errors due to system drift may be minimized.
Mitochondrial uptake of rhodamine 123 by rabbit articular chondrocytes
Authors: Benel L. , Ronot X. , Kornprobst M. , Adolphe M. , Mounolou J. C. 
Published: August 2005

AbstractRhodamine 123 was used to stain and analyze by flow cytometry the mitochondria of rabbit articular chondrocytes. Stationary primary cultures and exponentially growing subcultures were compared to enzymatically released chondrocytes from cartilage. The increase in mitochondrial fluorescence, when chondrocytes are transferred from cartilage to culture environment, is suggestive of some change in chondrocyte adaptation and/or differentiation in these conditions.
Construction and analysis of an EMBL‐3 phage library containing partially digested human chromosome 21‐specific DNA inserts (15–20 kb)
Authors: Janssen J. W. G. , Collard J. G. , Tulp A. , Cox D. , Millington‐Ward A. , Pearson P. 
Published: August 2005

AbstractIn the mouse‐human hybrid cell line SCC 16–5, chromosome 21 is the only human chromosome present. Fractions highly enriched for this chromosome were obtained by applying the chromosome velocity sedimentation technique to this cell line. DNA prepared from these chromosomal fractions was partially digested with Mbo I, size fractionated on an NaCl gradient, and cloned in the EMBL‐3 phage vector.The phage library thus prepared was highly enriched for human chromosome 21‐specific recombinant DNA sequences 15–20 kb long. Of the approximately 21,000 phage clones obtained, at least 99% were recombinant. Following phage plaque filter hybridization and Southern blotting, it was found that half of the recombinants were positive for human repetitive DNA. Almost all phages harbored highly or middle repetitive human or mouse DNA sequences owing to the large size of the recombinant inserts. In this library, the human chromosome 21 is represented approximately four times. All human recombinants studied thus far contained DNA inserts originating from chromosome 21 only. The employed cloning strategy is discussed with regard to utility, purity, quality, and completeness of chromosome‐specific recombinant DNA libraries.
Flow karyotyping of human melanoma cell lines
Authors: Arkesteijn Ger J. A. , Van Dierendonck Jan‐Hein , Vossepoel Albert M. , Cornelisse Cornelis J. 
Published: August 2005

AbstractSingle‐laser flow cytometry has been used to study the feasibility of flow karyotyping of human solid tumors. As a model, seven human melanoma cell lines have been used with varying numerical chromosome composition as verified by FCM DNA content measurements and chromosome countings. For all seven cell lines, flow karyotypes that showed a variety of consistent deviations from the normal diploid flow karyotype could be obtained although the resolution of the flow system and varying debris continuum limited the number of resolvable peaks. The predominant changes observed involved the regions normally representing chromosomes 3–8, 9–12, and 13–16. It is concluded that at present the preparation procedure is the main limiting factor for exploring the full potential of flow karyotyping for cytogenetic analysis of solid‐tumor cell lines.
Optimization of flow‐cytometric discrimination between reticulocytes and erythrocytes
Authors: Schmitz Franz J. , Werner Eckhard 
Published: August 2005

AbstractAn automatized technique to count reticulocytes by means of flow cytometry is described. Blood samples were stained by the fluorescent dye acridine orange without the use of fixative. Scatter and red fluorescence of the blood cells were measured in a flow cytometer. A discrimination between reticulocytes and erythrocytes was only achieved by using logarithmic amplification. The discrimination was better in peak mode than in area mode. The optimum dye concentration was 0.5 mg/liter acridine orange. At lower dye concentrations, not all reticulocytes were measured, whereas at higher dye concentrations the degree of discrimination between reticulocytes and erythrocytes decreased. There was a suitable discrimination between reticulocytes and erythrocytes. The reticulocyte numbers were scored by flow cytometry as well as by microscope for blood samples with 0.1–14% reticulocytes. The correlation between both methods was close.
Simultaneous separate detection of low angle and large angle light scattering in an arc lamp‐based flow cytometer
Authors: Steen Harald B. 
Published: August 2005

AbstractA device is described for simultaneous separate detection of the light scattering of cells at low and large scattering angles in an arc lamp‐based flow cytometer with epi‐illumination through an oil immersion microscope objective. Light scattering was measured in a dark field configuration that allows separate detection of light scattering greater than 2° and 15°, respectively. Dual parameter light scattering histograms of a blood cell suspension containing various types of leukocytes were closely similar to that obtained with a commercial laser‐based instrument with light scattering detection at forward and right angles. The sensitivity of the device was sufficient to measure polystyrene particles with 0.25‐μm diameter. A potential application may be differentiation of bacteria.
The induction of the human T‐cell growth factor receptor precedes the production of RNA and occurs in the presence of inhibitors of RNA synthesis
Authors: Redelman Doug , Wormsley Susan 
Published: August 2005

AbstractThe receptor for T‐cell growth factor (TCGF) is an activation antigen that is present in low amounts on a small fraction of resting T lymphocytes. The TCGF receptor on human T cells can be detected with the anti‐Tac monoclonal antibody within 7–12 h of stimulating the cells with phytohemagglutinin (PHA). In the current studies, we examined human lymphocytes cultured alone, with PHA, or with PHA plus sufficient actinomycin‐D to inhibit RNA synthesis. After varying intervals, aliquots of the lymphocytes were stained with acridine orange (AO) or pyronin‐Y(PY) to measure RNA and/or with anti‐Tac plus FITC goat anti‐mouse lg. Tac expression began to increase after 6–8 h incubation with PHA, whereas increases in PY or AO staining were not detected until 12 h or later. Furthermore, the initial increase in Tac expression was not affected by sufficient actinomycin‐D to block all detectable nucleic acid synthesis. Therefore, it appears that the initial expression of TCGF receptors detected after lymphocyte activation does not require de novo production of RNA.
Fluorescence‐activated sorting of individual cells onto poly‐L‐lysine‐coated slide areas
Authors: Kanz L. , Bross K. J. , Mielke R. , Löhr G. W. , Fauser A. A. 
Published: August 2005

AbstractCells sorted by a fluorescence‐activated cell sorter are collected onto small areas of a glass slide. These collection areas have been coated with poly‐L‐lysine to attach the cells firmly to the glass surface. This simple procedure proved to be suitable to sort single cells and small cell populations with preservation of cytomorphology and viability without modifying the cell sorter. Additional studies on sorted cells may be performed, as shown by preoxidase‐anti‐peroxidase analysis of cellular antigens and by mRNA in situ hybridization.
Improved high‐affinity monoclonal antibody to lododeoxyuridine
Authors: Vanderlaan Martin , Watkins Bruce , Thomas Cynthia , Dolbeare Frank , Stanker Larry 
Published: August 2005

AbstractThree monoclonal antibodies (Mabs), IU‐1, IU‐4, and B‐44 were evaluated in enzyme immunoassays (ELISA) and by flow cytometry for their abilities to recognize bromodeoxyuridine (BrdUrd)‐ and iododeoxyuridine (IdUrd)‐substituted DNA's, nucleotides, and nucleosides. IU‐4 is a new Mab, derived from mice immunized with 5‐iodo‐2′‐deoxyuridine‐5′‐monophosphate (IdUMP) conjugated through the phosphate group to albumin. This immunogen was selected to resemble IdUMP in DNA. In competition ELISA assays, IU‐4 prefers IdUrd to BrdUrd and prefers halogenated nucleotides over the corresponding nucleosides. In both ELISA and flow analysis, IU‐4 recognizes IdUrd in DNA at substitution frequencies at least as low as one IdUrd one per 1,000 normal bases. The high affinity of IU‐4 for IdUrd‐DNA contrasts with IU‐1 and B‐44, which show a strong binding dependency on the frequency of base substitution and require DNA that is essentially fully substituted with BrdUrd for binding in both flow and ELISA assays. The high affinity of IU‐4 for IdUrd in DNA and its independence of IdUrd residue spacing make it a superior reagent for the quantitative labeling of halogenated thymidine analogues in whole cells.
Spectral bandwidth in automated leukocyte classification
Authors: Zahniser D. J. , Brenner J. F. , Selles W. D. 
Published: August 2005

AbstractInvestigators have repeatedly pointed out the importance of spectral information in the automated classification of white blood cells. In general, monochromatic images recorded through two or three color filters are used to extract this information. Although it has generally been thought that the use of narrow band filters provides “cleaner” color information than is obtainable through wide band filters, the choice has not been fully investigated and the question is far from being settled. The use of wide band filters has the clear practical advantage of increased light levels at the detector, resulting in higher signal‐to‐noise ratio with less demand on light source design.In order to investigate this issue, a series of 681 leukocytes of the most frequently occurring types were digitized by the use of both narrow (10 nm) and wide (90 nm) band filters. Parameters were extracted independently from both sets of images. These parameters were then used to develop a classifier for each set of images. The choice of features and classifier results indicate that there are no major performance differences between the two types of filters.
DNA microspectrophotometry of bone sarcomas in tissue sections as compared to imprint and flow DNA analysis
Authors: Bauer Henrik C. F. , Kreicbergs Andris , Tribukait Bernhard 
Published: August 2005

AbstractThe aim of the present study was to establish an upper limit of diploidy for microspectrophotometric (MSP) DNA measurements in sections of mesenchymal tissue analyzing DNA data of a large number of normal cell populations. The reliability of this upper limit of diploidy for discriminating between diploid and hyperploid bone sarcomas was tested by analyzing the same tumors by MSP in imprint preparations and flow cytometry (FCM).The median DNA value of control cells in tissue sections was given arbitrary value of DNA index (DI) 1.0, denoting the diploid DNA content. The proportion of cells with DNA values exceeding DI 1.25 (>DI 1.25) was determined for each normal cell population. The maximum percentage of cells with DNA values exceeding DI 1.25, encountered by analysis of 91 normal cell populations in tissue sections, was 31%. This percentage was set as an upper limit of diploidy. Hence, tumors with a higher percentage of cells >DI 1.25 were classified as hyperploid. When we applied this criterion, 31 of 36 sarcomas analyzed by MSP in tissue sections were hyperploid, which was in complete agreement with FCM and MSP in imprints of the same tumors.Apart from discriminating between diploid and hyperploid tumors, an attempt was made to determine peak DNA values of sarcomas analyzed in tissue sections. Peak DNA values, as defined by a minimum of 30% of the cells within a class width of DI 0.25, could be determined for 23 of 36 tumors. These peak DNA values correlated well with corresponding peaks obtained by FCM.In conclusion, reliable discrimination between diploid and hyperploid tumors can be made by MSP in tissue sections provided the wide distribution of DNA values, inherent in the method, is taken into account. In selected cases, peak DNA values may be determined.
Electron microscopy microsampling of isolated nuclei sorted by flow cytometry
Authors: Zini Nicoletta , Matteucci Alessandro , Squarzoni Stefano , Galanzi Angela , Rizzoli Riccardo , Papa Stefano 
Published: August 2005

AbstractThis paper describes an efficient method to concentrate for electron microscopic examination minute quantities of subcellular particles obtained by cytofluorimetric sorting. The advantages of this micromethod, based on diafiltration on Millipore filters under constant positive nitrogen pressure, are discussed.
Design and application of a versatile triple‐laser cell and chromosome sorter
Authors: Lebo Roger V. , Bruce Barry D. , Dazin Paul F. , Payan Donald G. 
Published: August 2005

AbstractA high‐resolution triple‐laser sorter was designed and constructed to provide flexible switchover and high‐resolution sorting of cells or chromosomes with any combination of one, two, or three lasers. These features provide a central facility instrument that currently serves multiple users and analyzes different stain combinations with minimal switchover effort between experiments. Improved optics and mounts that focus the three laser beams independently are able to resolve beads and chromosomes better than our previously reported dual‐laser sorter. An improved signal collection unit with electronically controlled reference positions can be focused more quickly and precisely for any signal combination. A removable dye laser extends the range of usable fluorochrome labels. A rapid sheath switchover permits sorting of sterile cells and sterile chromosomes sequentially without additional sterilization or reservoir sheath change. Improved dual‐laser chromosome resolution is at least as good, analyzing 8,000 chromosomes/s, compared to the previous dual‐laser bench at 2,000/s. Stimulated and unstimulated peripheral blood lymphocytes were analyzed according to simultaneous measurements of cell surface receptors labeled with a fluoresceinated neuropeptide and a Texas red‐labeled antibody as well as DNA content during the cell cycle. These results demonstrate the broad range of potential applications of this triple‐laser system.
Two‐parameter data acquisition system for rapid slit‐scan analysis of mammalian chromosomes
Authors: Weier H.‐U. L. , Eisert W. G. 
Published: August 2005

AbstractA data acquisition system is described for recording two independent signals simultaneously from a laser‐based flow cytometer for rapid slit‐scan chromosome analysis. High‐aperture microscope optics allow recording of fluorescence distributions along the longest axis of metaphase chromosomes with a spatial resolution better than 1 μm. Fluorescence and small angle forward light scatter as well as dual‐wavelength fluorescence signals from Indian muntjac chromosomes stained with propidium iodide (PI) or acridine orange (AO) have been recorded simultaneously. While maintaining the multi‐user operation of the computer, photomultiplier signals are digitized at a rate of 400 signals per second, stored temporarily in high‐speed cache memories, and transferred subsequently to a minicomputer for further storage. Extensive software packages for data acquisition, analysis, and display of the results are described. Data acquisition is generally done in list mode, allowing complete reconstruction of individual signals (profiles) at any time. The distribution of stained constituents along the chromosomes can be displayed. Furthermore, histograms of various parameters of the input signals may be generated.
Fluorescence properties of allophycocyanin and a crosslinked allophycocyanin trimer
Authors: Yeh Sheila Walsh , Ong Linda J. , Glazer Alexander N. , Clark John H. 
Published: August 2005

AbstractData on the wavelength and temperature dependence of both time‐resolved and steady state fluorescence emission are presented for allophycocyanin (AP) and for a crosslinked allophycocyanin trimer (XL‐AP) (Ong LJ and Glazer AN: Physiol Veg 23:777–787, 1985). AP dissociates at high dilution and is not stable above 40°C even at moderate protein concentration. In contrast, XL‐AP does not dissociate even at very low protein concentrations and is completely stable up to 60°C in the presence of 0.75 M NaK‐phosphate, pH 7.0. The results show that XL‐AP is superior to AP for use in conjugates that abosrb and emit in the red region of the spectrum. The high stability of XL‐AP at elevated temperatures at high phosphate concentrations suggests that this derivative may be useful in conjunction with nucleic acid probes.
Coefficient of variation in flow cytometry of phagocytosis
Authors: Fujikawa‐Yamamoto Kohzaburo , Odashima Shizuo 
Published: August 2005

AbstractFluorescence histograms of V79 Chinese hamster lung cells containing phagocytized fluorescent microspheres were measured by flow cytometry. In the fluorescence histograms, the coefficient of variation (CV) of the peak for cells ingesting microspheres was not constant. Rather, it decreased with the number of microspheres ingested by the cells.