bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multistation multiparameter flow cytometry: Some influences of instrumental factors on system performance
Authors: Shapiro Howard M. , Feinstein David M. , Kirsch Albert S. , Christenson Lisa 
Published: August 2005

AbstractIn an effort aimed at design of a flow cytometer/sorter system in which light scattering, fluorescence, and extinction measurements could be made in as many as five spatially separated illuminating beams, the performance of different mechanical components, light sources, illumination and collection optics, and flow chambers was compared by changing individual components while maintaining the same basic instrument configuration. A protocol was developed, and is here described, allowing rapid setup of a flow cytometer using a mercury arc lamp and two laser beams for illumination. When two or more illuminating beams are derived from a single laser, it is generally necessary to incorporate automatic gain control in the detector electronics to compensate for source intensity fluctuations and so to achieve acceptable measurement precision. It is, however, possible to use a single laser beam as a source for several flow cytometers without the need for such compensation. Mercury arc lamps provide adequate excitation in the near ultraviolet (uv) for DNA fluorochromes, such as Hoechst 33342, and may be preferable to ion lasers for this purpose. Reported differences in precision and sensitivity between stream‐in‐air and enclosed flow systems appear owing more to differences in the illumination and collection optics used in different instruments; five flow chamber designs gave equivalent performance when tested in the same instrument. Relatively inexpensive achromatic microscope objectives of numerical aperture (NA) approximately 0.5 may offer the best combination of depth of focus and light gathering power when used as fluorescence collection lenses for flow cytometers; image plane apertures improve system performance in fluorescence measurement.
Cell surface antigens reacting with antiretrovirus sera on normal mouse spleen cells: A flow cytometric study
Authors: Szabó Gábor , D‐tóth Ferenc , Réthy Antal 
Published: August 2005

AbstractThe development of erythroleukemia in Balb/c mice injected with Rauscher leukemia virus has been followed by indirect immunofluorescence technique and flow cytometry, using antiserum against disrupted virions. The progression of the disease was accompanied by a great increase in the number of large, immunofluorescence positive cells. A subpopulation of normal spleen cells was also highly positive. The expression of the antigens in normal cells was examined in relation to the cell cycle. The majority of the S‐G2/M phase cells were found in the antigen positive compartment of larger cells. A two‐color analysis of immunofluorescence and DNA content revealed that the distribution of antigen expression in G1 phase was broad, gradually decreasing from a low‐intensity mode. The cell with double DNA content distributed evenly around a modus of five‐fold higher intensity. In experiments with stimulated bonemarrow cells, superiority of S‐phase cells in anti‐Rauscher serum binding was found. Cell‐surface gp70 antigen is suggested to be involved in this cell‐cycle dependent binding of antibodies by normal cells.
A practical graphical method for estimating the fraction of cells in S in DNA histograms from clinical tumor samples containing aneuploid cell populations
Authors: Ritch Paul S. , Shackney Stanley E. , Schuette William H. , Talbot Thomas L. , Smith Charles A. 
Published: August 2005

AbstractA graphical method for the analysis of unperturbed DNA histograms is presented in which the area of the normalized histogram subtended by the fraction of cells in S is represented by a trapezoid whose dimensions are dependent on features common to all such histograms. The technique takes measurement variability into account. This method was applied to a variety of synthetic DNA histograms. Overall, calculated values for the fraction of cells in S correlated well with actual values. This method was applied to 36 diploid cases of non‐Hodgkin lymphoma; results correlated well with those obtained by a computer‐based method. The results of the graphical‐method were also highly reproducible between different observers. The graphical method can be used in the presence of aneuploid cell populations. Techniques for calculating S fractions in the presence of aneuploidy in clinical samples are described. These techniques were applied to synthetic histograms of mixed diploid and aneuploid populations. Calculated values correlated well with actual values.
A differential amplifier circuit for reducing noise in axial light loss measurements
Authors: Steinkamp John A. 
Published: August 2005

AbstractSimplified electronics have been developed for reducing laser excitation source light intensity fluctuations in flow cytometric axial light loss (extinction) measurements. By continuously monitoring the laser output with a photodiode detector and combining it with the axial light loss signal from a second detector using a high‐speed differential amplifier, background interference is reduced 10 to 40 dB. Oscilloscope waveforms and frequency distribution histograms recorded from uniform‐size polystyrene latex spheres and human mononuclear blood cells are used to illustrate the noise reduction capabilities.
Purifying human Y chromosomes by flow cytometry and sorting
Authors: Fantes Judith A. , Green Daryll K. , Cooke Howard J. 
Published: August 2005

AbstractA method of producing an enriched sample of human Y chromosomes from peripheral blood lymphocytes is described. Metaphase chromosomes were prepared from peripheral blood lymphocytes donated by 17 normal male individuals. A suspension of chromosomes in a polyamine buffer was produced from each sample, stained with the fluorescent dye Hoechst 33258, and passed through a flow cytometer and sorter. Following analysis of the 17 fluorescence distributions, a single donor was found giving a separate peak corresponding to the Y chromosome. Seventy percent of the chromosomes sorted from this peak were identified as Y chromosomes. Batches of a million Y chromosomes were produced from each of several 40 ml donations of peripheral blood. These were assessed for the amount of Y DNA present and used to construct a DNA library.
Flow cytometric classification of biopsy specimens from cervical intraepithelial neoplasia
Authors: Jakobsen A. , Kristensen P. Baek , Poulsen H. Kvist 
Published: August 2005

AbstractThe distribution of single‐cell DNA content was investigated in biopsy specimens from the human cervix of 121 women suspected of having intraepithelial neoplasia. Comparison of the results of the histopathological examination with the ploidy level showed that all normal specimens were diploid. Thus, no false‐positive results occurred. Most of the specimens classified as mild and moderate dysplasia were diploid as well. Aneuploid cell populations occurred in 78% of the lesions classified as severe dysplasia and carcinoma in situ. The ploidy level distribution permitted a natural division of the aneuploid cell populations into two groups with DNA indices either above or below 1.5. The importance of the aneuploidy in carcinogenesis is discussed.
Non‐small‐cell lung carcinoma: Tumor characterization on the basis of flow cytometrically determined cellular heterogeneity
Authors: Teodori Laura , Tirindelli‐Danesi Donatella , Mauro Francesco , De Vita Raffaele , Uccelli Raffaella , Botti Claudio , Modini Claudio , Nervi Carlo , Stipa Sergio , Teodori Laura 
Published: August 2005

AbstractSome 150 tumor specimens from 49 patients with non‐small‐cell carcinoma of the lung (23 epidermoid, 14 adenocarcinoma, 12 large‐cell carcinoma) and three with nonneoplastic lung disease were analysed for cellular DNA content by flow cytometry. Monodispersed cells were stained with ethidium bromide and mithramycin. Normal specimens and samples from patients with nonneoplastic disease constantly yielded a single cell population with diploid DNA content. Twenty of 23 epidermoid carcinomas exhibited one or more than one aneuploid subpopulation. Ten of 12 large‐cell carcinomas were characterized by one aneuploid clone and 2/12 by two aneuploid clones. Adenocarcinoma exhibited multiclonal cell subpopulations (one to five aneuploid clones). Further information has been obtained on the differential presence of clones in various tumor areas and in infiltrated lymph nodes. These tumors appear characterized by a remarkable degree of cellular heterogeneity. The cytometric ploidy level(s) and the cell population multiclonal structure yield, in comparison with, and in addition to, pathology, indications of possible clinical interest. A correlation between the clonal DNA content and a prognostic parameter such as the tumor mass doubling time has been demonstrated.
Difference in chromatin sensitivity to heparin of chronic atrophic gastritis, of carcinoma‐free and carcinoma‐bearing stomach in comparison with normal gastric mucosa and gastric carcinoma as revealed by flow cytometry
Authors: Weiß H. , Heinz U. , Gütz H.‐J. , Schälicke W. 
Published: August 2005

AbstractDNA distribution patterns from gastric mucosal cells corresponding to four groups defined by histological examination were measured by flow cytometry before and after treatment with heparin, a polyanion. Group I comprised normal gastric mucosal cells; group II, chronic atrophic gastric mucosal cells originating from a carcinoma free stomach; group III, chronic atrophic gastric mucosal cells originating from a carcinoma bearing stomach; and group IV, malignant gastric mucosal cells. The heparin concentrations used were 1.25, 1.5, and 5 U/ml cell suspension. Heparin caused increases in fluorescence intensity and in coefficients of variation, which are interpreted as a reflection of alterations in chromatin structure. For the four groups investigated, the heparin‐initiated changes were dependent, in varying degree, on concentration and time. Group I showed a much more extensive sensitivity to heparin than group IV. Group II and III reacted similarly to group I or group IV, depending on the source, i.e., either a carcinoma‐free stomach or a carcinoma‐bearing stomach. Further extension of this method might yield information concerning the real premalignant potential of a specific case of chronic atrophic gastritis.
Flow cytometric analysis of micronuclei found in cells after irradiation
Authors: Nüsse Michael , Kramer Johannes 
Published: August 2005

AbstractExposure of mammalian cells to either ionizing radiation or mutagenic and carcinogenetic substances can induce chromosome aberrations. These aberrations in turn may give rise to micronuclei which can be found in cells during the interphase after division. A two‐step method is presented that allows separation of micronuclei from cell nuclei. They can then be measured and analysed according to their DNA content in a flow cytometer. The method involves an initial detergent treatment of cells followed by a second treatment with sucrose and citric acid. Micronuclei with DNA content larger than 2% of the G1‐nuclei can be measured. The method is tested and compared with microscopic observations of micronucleated cells in irradiated, asynchronous, and synchronized Ehrlich ascites tumour cells growing in vitro. The agreement between the flow cytometric technique and microscopic observations is excellent when the dose‐dependent number of micronuclei per cell is taken into consideration.
An assay for pattern formation in dictyostelium discoideum using monoclonal antibodies, flow cytometry, and subsequent data analysis
Authors: Voet L. , Krefft M. , Mairhofer H. , Williams K. L. 
Published: August 2005

AbstractAn assay for determining the proportions of prespore cells in a simple multicellular organism, the slug stage of Dictyostelium discoideum, was established using a presporespecific monoclonal antibody and a fluorescence‐activated cell sorter. Appropriate techniques for data analysis were developed.The effects of slug size and age were determined. Small slugs have a lower percentage of prespore cells than large slugs. The percentage of prespore cells increases and then decreases in slugs aged between a few hours and 9 days. Pronounced effects were observed on the size of cells in aging slugs. In particular unlabelled (mostly prestalk) cells were larger than prespore cells in young slugs, but after 6 days migration they became considerably smaller than prespore cells. The fact that all unlabelled cells were coordinately shifted in size, suggests that these cells (which comprise prestalk, prestalklike, and predisc cells) are related to each other.
Cytometrically determined relative DNA content as an indicator of neoplasia in gastric lesionis,
Authors: Teodori Laura , Capurso Lucio , Cordelli Eugenia , De Vita Raffaele , Koch Maurizio , Tarquini Maurizio , Pallone Francesco , Mauro Francesco 
Published: August 2005

AbstractCellular samples from human gastric endoscopic biopsies were analysed in order to detect possible DNA content alterations as markers of cancerous and precancerous lesions of the digestive tract. Samples were derived from the stomach of normal donors (17 cases), and from patients clinically classified as affected by stomach adenocarcinoma (18 cases), chronic atrophic gastritis (20 cases), or other non‐neoplastic lesions (17 cases). Sample processing was performed by mechanical and enzymatic treatment to obtain monodispersed cells. Staining for flow cytometric analysis was achieved with ethidium bromide and mithramycin. Samples from normal donors constantly exhibited a single cell population with diploid DNA content. All but three neoplastic specimens exhibited both a diploid and an aneuploid cell subpopulation, with the DNA index of the aneuploid peak ranging from 1.10 to 1.85 (except a single instance with a value of 3. 13). The presence of a recognizable aneuploid subpopulation was also observed in 9 out of 20 chronic atrophic gastritis specimens. Such aneuploidy is similar to that observed for the adenocarcinoma, even if the fraction of aneuploid cells appears to be generally higher in the tumor than in the gastritis cases. All other cases of gastritis and of non‐neoplastic disease exhibited diploid cells only. The meaning of aneuploidy in some gastritis specimens is a phenomenon not yet fully explained. Still, aneuploidy appears to be a useful marker for recognizing the presence of suspect malignant cells in gastric lesions.
A follow‐up study of the development of Rauscher erythroleukemia,
Authors: Szabó Gábor , Mátyus László 
Published: August 2005

AbstractExpression of cell membrane antigens recognized by antiserum raised against purified Friend murine leukemia virus (Fr‐MuLV) envelope glycoprotein (gp71) and by xenotropic MuLV‐coded cell surface antigen (XenCSA) specific antibodies was studied in the course of the development of Rauscher erythroleukemia in the spleen of Balb/c mice. DNA content vs immunofluorescence or light scattering of cells were simultaneously analyzed. At early stages of the disease (4–5 days after infection) the gp71 and XenCSA‐related antigen expression is enhanced mainly on S‐G2/ M‐phase cells as compared to the majority of G1‐phase cells or to the endogenous background of uninfected cells. Later (around 10 days after infection) an approximately tenfold increased gp'71‐related antigen density is reached in every phase of the cell cycle. These data show that the virus‐induced transition from resting to proliferating state is coupled to enhanced expression of both helper and defective viral env‐gene products in the cell membrane of mitotic and G1‐phase cells as well.
Analytic studies of foam cells from breast cancer precursors
Authors: King Eileen B. , Kromhout Lois K. , Chew Karen L. , Mayall Brian H. , Petrakis Nicholas L. , Jensen Ronald H. , Young Ian T. 
Published: August 2005

AbstractA preliminary study of foam cells from nipple aspirate fluid demonstrated the ability of image analysis to discriminate categories of breast disease. Foam cell images numbering 471 were collected from nipple aspirate samples representing three to six cases of each of the four following disease categories based on breast tissue diagnosis: benign, nonproliferative; hyperplasia; atypical hyperplasia; and cancer. Twentytwo shape and density parameters were measured for each cell image. Using multivariate analysis, eight nuclear and three cytoplasmic parameters showed significant differences (P < 0.005) when tested among cell populations from the breast disease categories. Linear stepwise discriminant analysis enabled construction of a three‐parameter model that was optimal for distinguishing among cell populations from the four categories of breast disease. The means of all twenty‐three parameters were then evaluated on a per‐patient basis. A second three‐parameter model was constructed that distinguished, with 100% accuracy, patients with proliferative disease from those with nonproliferative disease. Grouping disease categories and comparing patients whose diagnosis was benign or hyperplasia versus atypical hyperplasia or malignant, the model placed patients in the correct group 83% of the time.
Use of flow cytometry in industrial microbiology for strain improvement programs
Authors: Betz J. W. , Aretz W. , Härtel W. 
Published: August 2005

AbstractA flow cytometry (FCM) system was chosen to analyze and sort microbiological samples, e.g., bacteria, bacterial spores, yeasts, and fungal spores, without major changes in the commercially available state. The system was further improved by addition of a stepping motor‐driven scanning table that accepts standard petri dishes or microtiter plates. The electronics of the sorting system were changed to enable the sorter to deliver only one particle at a time, working in a “handshake” mode with the scanning table. Appropriate parameters, depending on the biological material and including all fluorescent stains that do not impair growth and productivity of cells were chosen to sort distinct bioparticles under aseptic conditions and to clone colonies or cultures out of them. A mutagenized sample of spores entering the germination cycle can be followed and thus provide a means to pick only viable growing cells despite the killing effect of the mutagen. One example of a typical strain improvement is illustrated. From a spore suspension of Rhizopus arrhizus, a subpopulation of morphologically different spores comprising about 5–10% of the whole population was cloned. From approximately 8,000 clones, 10 were isolated that produced approximately five‐ to six‐fold the amount of fungal lipase activity, compared to the original strain or to reisolated clones from the mean population of clones.
Three‐color immunofluorescence analysis of leu antigens on human peripheral blood using two lasers on a fluorescence‐activated cell sorter
Authors: Loken Michael R. , Lanier Lewis L. 
Published: August 2005

AbstractA fluorescence‐activated cell sorter was modified to quantify simultaneously three immunofluorescence stains on a population of cells. A dye laser containing rhodamine 6G was used to obtain 600 nm light to excite Texas Red coupled avidin. An argon ion laser operating at 488 nm excited both fluorescein and phycoerythrin directly conjugated antibodies. The emission from these fluorophores could be independently quantified as demonstrated by the histograms generated by samples labeled separately with each of the three stains. This three‐color detection system was used to analyze human peripheral blood mononuclear cells for the expression of three antigens: Leu 2, Leu 7, and Leu 11. Upon reanalysis of the list mode data, several discrete subpopulations of lymphocytes could be identified based on the quantitative expression of these three antigens. Of particular interest in the normal sample studied was a population of dimly labeled Leu 2+ cells which were predominantly Leu 11+, a phenotype which is seen infrequently in normal individuals. This technique expands the combinations of antigens that can be studied at any one time and will facilitate the detection and functional analysis of cells in heterogeneous populations.
Fluorescence polarization of six membrane probes in embryonal carcinoma cells after differentiation as measured on a FACS II cell sorter
Authors: Schaap G. H. , De Josselin De Jong J. E. , Jongkind J. F. 
Published: August 2005

AbstractFluorescence polarization measurements on a FACS II cell sorter were compared with static measurements on a spectrofluorimeter using calibration solutions and Hoechst 33258‐labeled cells. For the flow cytometric measurements on the FACS we used a pseudodepolarizer for normalization of the output of the two photomultipliers. The results showed that fluorescein and fluoresceinated bovine serum albumin (BSA) solutions gave identical values on both instruments. The mean value for fluorescence polarization of Hoechst 33258‐labeled cells as measured on the FACS was the same as the value obtained with the spectrofluorimeter.Subsequently the fluorescence polarization of six different membrane probes was determined using differentiating embryonal carcinoma cells as a model system. Differentiation was induced by treatment of the cells with retinoic acid together with cyclic AMP. With diphenylhexatriene (DPH) the fluorescence polarization increased from I‖/I = 1.55 to 1.74 upon differentiation. With a charged analog of DPH (TMA‐DPH) fluorescence polarization increased from I‖/I = 1.87 to 2.02. No appreciable changes in fluorescence polarization were observed in this cell system when anthroyloxysterate probes (12‐AS, 9‐AS, 6‐AS, 2‐AS) were used.
Flow cytometric analysis of the binding of eleven lectins to human T‐ and B‐cells and to human T‐ and B‐cell lines
Authors: Malin‐Berdel Jeannette , Valet Günther , Thiel Eckhart , Forrester John Anthony , Gürtler Lutz 
Published: August 2005

AbstractThe relative surface binding of 11 lectins to human peripheral blood T‐ and B‐lymphocytes, to Molt‐4 and JM T‐cell lines, and to 6410 and NC37 B‐cell lines was determined by flow cytometry. The lectins from Lens culinaris (LCA), Ricinus communis (RCA), Arachis hypogaea (PNA), Abrus precatorius (APA), Ulex europaeus (UEA‐F), Sarothamnus scoparius (SAS‐F), Helix pomatia (HPA), Phaseolus coccineus (L‐PHA), Glycine max (SBA), and Triticum vulgare (WGA) were fluoresceinated and incubated with living, formaldehyde‐fixed, or neuraminidase‐treated cells. Except LCA, which preferentially bound to the two B‐cell lines tested in this study, none of the other lectins exhibited selective binding to the undifferentiated cells of the cell lines. The T‐cell lines and, in part, the peripheral blood T‐cells bound less WGA, APA, LCA, and L‐PHA than the B‐cell lines and the peripheral blood B‐cells. Binding of PNA was found only after neuraminidase treatment of the cells; the binding of PNA, HPA, and UEA‐F after neuraminidase treatment was higher for the T‐cells than the B‐cells from peripheral blood. No significant differences were detected between both cell types for RCA, ConA, SBA, and SAS‐F.
Comparison of digital focus criteria for a TV microscope system
Authors: Harms H. , Aus H. M. 
Published: August 2005

AbstractExisting focusing methods, such as standard deviation of gray values, gradients, information content of the image and the lateral inhibition function, were compared, and a new combination criterion was developed. This combined method consists of using the standard deviation of the image for coarse focusing followed by a modified form of the lateral inhibition for the fine focus. The lateral inhibitor model of the eye is a recursive filter that can be simplified to a nonrecursive filtering algorithm, as postulated by Rechenberg. The reported focus method operates over a focusing range (z‐axis) of ± 300 μm and is accurate within ±0.1 μm in the transmission, dark‐field, and phase contrast microscope.