Internal Reference Standard Research Articles

Rapid and sensitive LC/MS/MS analysis of the novel tyrosine kinase inhibitor ZD6474 in mouse plasma and tissues

ZD6474 ( N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-[(1-methylpiperidin-4-yl)methoxy] quinazolin-4-amine) is a tyrosine kinase inhibitor with anti-angiogenic and anti-tumor activity that is currently undergoing human trials for cancer treatment. Pharmacokinetic studies in animal models are an important component in clinical development of this agent to relate pre-clinical models to patient treatment. A liquid chromatography tandem mass spectrometry method was developed for the determination of ZD6474 levels in mouse plasma and tissues. Plasma (0.05 mL) and tissue homogenates (0.1 mL of 10 mg/mL) were extracted under alkaline conditions with ethyl acetate:pentane (1:1, v/v) after addition of the internal standard (trazodone, 2-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-1,2,4-triazolo[4,3-a]pyridine-3(2H)-one). Separation was achieved on a C18, 50 mm × 2 mm column with quantitation by internal standard reference and multiple reaction monitoring of the ion transitions m/ z 475 → 112 (ZD6474) and m/ z 372 → 176 (trazodone). The calibration curve was linear from a range spanning 20–20,000 ng/mL in plasma and 10–320 ng/mg in tissue homogenates. Mean recoveries from plasma and tissue homogenates were 88 and 90%, respectively. The accuracy in plasma was 88% at the lower limit of quantitation (20 ng/mL with a 50 μL plasma sample) with high precision (R.S.D.% < 10%). Assay performance in liver and other tissue homogenates is also reported. The assay was applied to a pharmacokinetic study in mice to determine dosing schedules that would approximate therapeutic ZD6474 levels determined in humans.

Overweight and obesity epidemic among children. Answer from European countries

To investigate the methods and results used and conclusions found in available published papers on childhood overweight and obesity in Europe. This paper compares the two available published papers on the prevalence of child and adolescent overweight and obesity in Europe. The first paper was published in November 2003 and was based on 20 previously conducted surveys performed from 1992 to 2001. The other paper was published in January 2004 and was based on data from the WHO collaborative survey 'Health Behaviour in School Children', which collected the data in 1997-1998 within a period of 9 months. Height and weight were included as optional questions and 13 European countries, Israel and United States participated. In both papers, body mass index (BMI) was used. In the first paper, measured BMI was used and prevalence of overweight was calculated using IOTF cutoff points. In the other paper, overweight and obesity prevalences were calculated from self-reported height and weight using an internal study reference standard. The first paper found a north-south trend in overweight in Europe, whereas the second found a more equal distribution of overweight in European children. Thus, overweight was significantly increased among 13 y olds of both sexes in Finland, Ireland, and Greece, and in Portuguese girls. Among 15 y olds, the prevalence of overweight was significantly increased in Greek boys, and in Danish and Portuguese girls. On the contrary, in Lithuania, there was a significantly low prevalence of overweight among both ages and both sexes. Critical reviews of the results of the two published papers show that the year of data collection, methods and use of appropriate statistics are of critical importance for the conclusion drawn from comparative epidemiological surveys on the prevalence of overweight.

Quantitative mass spectrometric immunoassay of insulin like growth factor 1.

Reported in this work are the development of mass spectrometric immunoassay (MSIA) devices and methods for the qualitative analysis of IGF-1 and -2, and the rigorous quantification of IGF-1 from human plasma. A method involving addition of SDS in moderate concentration to unfractionated plasma for disrupting IGF/IGFBP complexes was initially developed. The method is suitable for the direct extraction of the IGFs and subsequent mass spectrometric analysis. Rat plasma, containing IGF-1 that is mass shifted from human IGF-1, was used as an internal reference standard (IRS) for the quantification of IGF-1 directly from human plasma. A standard curve with linear dynamic range of at least 2 orders of magnitude was constructed from serially diluted IGF-1 standards containing equal amounts of rat plasma. Using the standard curve, IGF-1 levels in plasma samples from eight individuals were determined. The limit of detection for the IGF-1 MSIA was also evaluated and established to be approximately 15 pM. The assay is rapid and can be performed in parallel via high-throughput robotics processing. Furthermore, the mass spectrometry aspect of the developed IGF-1 immunoassay offers a new dimension in the ongoing study of IGF-1 and related diseases.

17O quantitative nuclear magnetic resonance spectroscopy of gasoline and oxygenated additives.

17O Nuclear magnetic resonance (NMR) spectroscopy allows exclusive detection and direct quantification of oxygenates in gasoline unaffected by its hydrocarbon content, using the internal standard quantitative NMR (QNMR) method. Chemical shifts of 24 oxygen-containing compounds as potential additives and contaminants have been measured in gasoline and corrected values of deltaO 18.1 and 3.9 determined for neat methyl tert-butyl ether (MTBE) and neat di-n-butyl ether, respectively. Quantification of ethanol in gasoline can be readily achieved by 17O QNMR with dimethyl sulfone as an internal standard reference material, at the levels currently used in retail gasolines (1-20%). In addition, the simultaneous detection and quantification of the oxygenates methanol, ethanol, 2-propanol, tert-butyl alcohol, and MTBE in gasoline has been established to further demonstrate the specificity of the method. 17O NMR has distinct advantages over 1H and 13C QNMR methods, and although it cannot reliably differentiate 1-propanol, 1-butanol, 1-pentanol, and isopentyl alcohol, 17O NMR does allow the rapid and unambiguous identification of unexpected oxygenates such as acetates and ketones found as contaminants in some retail gasoline.

Rapid detection of aneuploidy in Musa using flow cytometry.

We report a procedure for the rapid and convenient detection of aneuploidy in triploid Musa using DNA flow cytometry. From a population of plants derived from gamma-irradiated shoot tips, plants were selected based on aberrant morphology and their chromosome numbers were counted. Aneuploids plants with chromosome numbers 2n=31 or 32 were found as well as the expected triploid plants (2n=3x=33). At the same time, the nuclear DNA content of all plants was measured using flow cytometry. The flow cytometric assay involved the use of nuclei isolated from chicken red blood cells (CRBC), which served as an internal reference standard. The relative DNA content of individual plants was expressed as a ratio of DNA content of CRBC and Musa (DNA index). In order to estimate the chromosome number using flow cytometry, the relative DNA content of plants with unknown ploidy was expressed as a percentage of the DNA content of triploid plants. The classification based on flow cytometry fully agreed with the results obtained by chromosome counting. The results indicated that flow cytometry is a convenient and rapid method for the detection of aneuploidy in Musa.

Apoptotic rate: a new indicator for the quantification of the incidence of apoptosis in cell cultures.

Late apoptotic cells divide into apoptotic bodies and are missed by current detection methods. This results in an artificially low apoptotic index (AI). This study proposes a flow cytometry-based ratiometric method that uses an internal reference standard of microbeads combined with fluorescein-annexin V binding and 7-aminoactinomycin D to enumerate viable, necrotic, and early and late apoptotic cells within specific subsets of a heterogeneous culture. In the absence of cell growth, the number of apoptotic cells that undergo fragmentation into apoptotic bodies in culture can also be determined accurately by this method. This information can then be used to obtain the apoptotic rate (AR), a new indicator of apoptosis that calculates the proportion of cells that have undergone apoptosis with respect to the total number of seeded cells. The main limitation of the method is that the AR is only suitable for the study of apoptosis in noncycling cells. This study reveals the superiority of the proposed method over the widely used Nicoletti method and current annexin-V binding methods. The AI did not reflect the true incidence of lymphocyte apoptosis, neither in response to lectins or phorbol esters, nor to serum deprivation. AR was more sensitive than AI, detecting apoptosis at lower concentrations of cell death inducers in all the subsets studied.

In Vivo Sodium MR Imaging of the Intervertebral Disk at 4 T

Rationale and Objectives The authors performed this study to evaluate whether a semiquantitative method of in vivo sodium imaging of the human intervertebral disk could provide diagnostic quality images in a reasonable time. Materials and Methods In vivo sodium imaging of the human spine was performed with a 4-T whole-body magnetic resonance (MR) unit by using custom-built hardware and software. Short-echo-time images were obtained with a modified three-dimensional gradient-echo sequence, a custom-built surface coil, and receiver modifications to allow for nonproton data acquisition. Corrections for surface coil image intensity were performed with phantom image data. An estimation of the fixed charge density within the intervertebral disk was made with the surface coil–corrected images by using cerebrospinal fluid as an internal reference standard. Results In vivo sodium images of the spine with high signal-to-noise ratio and resolution were obtained in approximately 10 minutes. Correction of in vivo images for surface coil effects demonstrated that the sodium content of the cerebrospinal fluid in the spinal canal may be used as an internal standard to estimate the proteoglycan content of the intervertebral disk. Conclusion Diagnostic quality in vivo sodium images of the intervertebral disk are technically feasible and may be useful for assessing the proteoglycan content of the intervertebral disk. This would provide a method to detect early degenerative changes in the disk and evaluate the effects of any subsequent therapy.

DETERMINATION OF CERTAIN ANTISPASMODIC DRUGS AS SINGLE INGREDIENT, MEBEVERINE HYDROCHLORIDE, AND IN TWO COMPONENT MIXTURES, MEBEVERINE HYDROCHLORIDE–SULPIRIDE AND ISOPROPAMIDE IODIDE–TRIFLUOPERAZINE HYDROCHLORIDE

ABSTRACT Two simple and sensitive methods are described for the quantitative determination of mebeverine hydrochloride as single ingredient. The first method depends on the application of quantitative 1H-NMR spectroscopy using deuterated chloroform and hexamine as an internal reference standard. The second method is based on measuring the native fluorescence of mebeverine hydrochloride in 0.1 N sulphuric acid at 360 nm with excitation at 290 nm. Furthermore simultaneous determinations of two component mixtures, mebeverine hydrochloride with sulpiride and isopropamide iodide with trifluoperazine hydrochloride are presented using first-derivative and second-derivative UV-spectrophotometry, respectively. The proposed methods have been successfully applied to the determination of the cited drugs in commercial tablets. Compared with the reference methods, the proposed methods are more sensitive, with good accuracy and reproducibility.

Reproducibility of Bordetella pertussis genomic DNA fragments generated by XbaI restriction and resolved by pulsed-field gel electrophoresis.

The intra- and interlaboratory variabilities of the molecular size measurements of each DNA fragment contributing to three pulsed-field gel electrophoresis (PFGE) profiles were assessed, as were the reproducibilities of the entire PFGE profiles for three Bordetella pertussis strains. The major source of variability within a laboratory occurred between subcultures rather than within gels or between gels. Each PFGE profile was generated reproducibly and was objectively defined by the molecular sizes of its composite fragments. A strain or profile most suitable for use as an internal reference standard was identified.

A method of locating dried residue on a semiconductor wafer in vapor phase decomposition-total-reflection X-ray fluorescence spectrometry by monitoring scattered X-rays

Vapor phase decomposition-total-reflection X-ray fluorescence spectrometry (VPD-TXRF) is used in the analysis of whole-surface trace metal contamination on silicon wafers at a very high sensitivity. In VPD-TXRF, locating the exact position of dried residue is critical for obtaining a reliable analysis. To locate the residue, the fluorescence from the internal element added as standard reference for quantification is most commonly used as a search marker. However, the added internal standard reference sometimes interferes with the determination of analytes. To avoid such interference, we introduce a new method of locating the residue that utilizes the scattered X-rays from it. Basic experiments have shown that scattered X-rays can be used as markers of residue position instead of the fluorescence from an internal standard reference. An x– y–θ-controlled stage has been proven to be preferable in the application of this locating method than an r–θ-controlled stage. The repeatability of our method is the same as that of the conventional internal standard reference method. There are many advantages in our new method: no interference with analytes of interest, speed, and ease of application. In addition, the method is compatible with the conventional internal standard reference method.

Evanescent Electric Field Amplitudes in Thin Lipid Films for Internal Reflection Infrared Spectroscopy

Internal reflection infrared spectroscopy is a commonly used technique for determining the conformation and orientation of polypeptides in thin films such as supported lipid membranes. Accurate determinations of molecular orientation by this technique depend on accurate calculations of evanescent electric field amplitudes. These calculations, in turn, depend on film thickness and assumptions about the dielectric behavior within such films. Different assumptions lead to either two-phase or three-phase approximations for calculating electric field amplitudes, and both approximations are widely used. To test the accuracy of these approximations, we have examined a series of trisubstituted benzenes for their suitability as an internal orientation reference standard. We find that 1,3,5-tri-tert-butyl-benzene is absorbed into supported lipid membranes and exhibits an infrared absorption dichroism that is well described by the two-phase approximation but is inconsistent with the three-phase approximation. These ...

Development of an ELISA for the diagnosis of Corynebacterium pseudotuberculosis infections in goats

An ELISA was developed for the diagnosis of Corynebacterium pseudotuberculosis infections in goats. A bacterial whole cell extract was used as solid-phase antigen, and serum from a culture-positive animal served as the internal reference standard. The well-to-well and assay-to-assay variations were determined to be 12.7 and 33.0%, respectively. A cut off value was determined by parallel testing of 142 sera (112 ELISA-positive, 30 ELISA-negative) in a Western blot, and the correlation between both tests was highly significant ( K=0, 93). In addition, the reliability of the ELISA for the detection of infected herds was proven in a double blind study testing 910 sera from 74 goat herds.

Determination of double bond conversion in dental resins by near infrared spectroscopy

Objectives: This study determined the validity and practicality of near infrared (NIR) spectroscopic techniques for measurement of conversion in dental resins. Methods: Conversion measurements by NIR and mid-IR were compared using two techniques: (1) The conversion of 3 mm thick photopolymerized Bis-GMA/TEGDMA resin specimens was determined by transmission NIR. Specimens were then ground and reanalyzed in KBr pellet form by mid-IR. (2) As further verification, thin resin films were photocured and analyzed by mid-IR. Multiple thin films were then compressed into a thick pellet for examination by NIR. Results: Conversion values obtained by NIR and mid-IR techniques did not differ significantly. A correction for changing specimen thickness due to polymerization shrinkage was applied to NIR conversion measurements since an internal standard reference peak was not employed. Sensitivity of the NIR technique was superior to those based on the mid-IR. Significance: The nondestructive analysis of conversion in dental resins by NIR offers advantages of convenience, practical specimen dimensions and precision compared with standard mid-IR analytical procedures. Because glass is virtually transparent in the NIR spectrum, this technique has excellent potential for use with filled dental resins as well.

Patterns of genome size in the copepoda

Adult somatic nuclear DNA contents are reported for eleven cyclopoid species (Megacyclops latipes, Mesocyclops edax, M. longisetus, M. ruttneri, M. leuckarti, M. woutersi, Macrocyclops albidus, Cyclops strenuus, Acanthocyclops robustus, Diothona oculata, Thermocyclops crassus) and for the harpacticoid Tigriopus californicus and range from 0.50 to 4.1 pg DNA per nucleus. These diploid genome sizes are consistent with previously published values for four Cyclops species (0.28–1.8 pg DNA per nucleus), but are strikingly smaller than those reported for marine calanoids (4.32–24.92 pg DNA per nucleus). We discuss three explanations, none of them exclusive of another, to account for the smaller size and range of cyclopoid genome sizes relative to calanoid genome sizes: (1) higher prevalence of chromatin diminution in the Cyclopoida, (2) phylogenetic structure or older age of the Calanoida relative to Cyclopoida and (3) nucleotypic selection that may influence life history variation and fitness. Measurements of genome size were made on Feulgen stained, somatic cell nuclei, using scanning microdensitometry which is well suited to the sparse and heterogeneous populations of copepod nuclei. The importance of measuring large numbers of nuclei per specimen, possible sources of variation associated with cytophotometric measurements, and appropriate use of internal reference standards and stoichiometry of the Feulgen stained nuclei are discussed.

Application of yeast cells transformed with GFP expression constructs containing the RAD54 or RNR2 promoter as a test for the genotoxic potential of chemical substances

Yeast strains transformed with high copy number plasmids carrying the gene encoding a green fluorescent protein optimised for yeast (yEGFP3) under the control of the RAD54 or RNR2 promoter were used to investigate the activity of potentially DNA-damaging substances. The assays were performed on 96-well microtitre plates in the presence of different concentrations of the test substances. The synthesis of GFP protein was measured through the fluorescence signal and cell growth was monitored by absorption. Here, we demonstrate that this system can be used as a biosensor to assess the genotoxic potential of drugs and other chemical substances. The use of microtitre plates will enable full automation of the system and allows the inclusion of internal reference standards in each assay.

Quantitation of T-cell receptor frequencies by competitive PCR: generation and evaluation of novel TCR subfamily and clone specific competitors.

T cell receptor (TCR) V gene usage has been used to characterize the immune response to bacteria, viruses, allografts, self antigens, tumor antigens, and superantigens. Sensitive methods to detect changes in the frequency of TCR subfamilies or clonotypes might be useful in evaluating the efficacy of vaccines against infectious agents, immunotherapy treatments for cancer patients, or the status of autoimmune diseases. Two HLA-A2 restricted CTL clones expressing BV17 were isolated from a tumor infiltrating lymphocytes (TIL) culture of a patient with metastatic melanoma. One clone recognized the MART-1(27-35) peptide and the other clone recognized the gp100(209-217) peptide. The frequency of each of these CTL clones in an expanding TIL culture was measured using a novel competitive RT-PCR (cRT-PCR) strategy. cRT-PCR uses a single primer pair to amplify template cDNA simultaneously with a modified DNA competitor molecule. A rapid two-step PCR technique followed by a single cloning step was used to generate a TCR BV17 subfamily specific competitor or competitors specific for the MART-1(27-35) reactive CTL clone (CO-41) and the gp100(209-217) reactive CTL clone (CO-4). Each competitor contained a segment of the TCR BC region that served as an internal reference standard. Using the BV17 competitor we were able to accurately and reproducibly measure cDNA templates at a frequency as low as 1/100,000 using cDNA samples of known TCRBV subfamily composition. This competitor was used to monitor the frequency of BV17 expressing T cells in the TIL and PMBC of a patient with metastatic melanoma. We determined that the frequency of BV17 expressing T cells increased from 4.5% of the culture on day 35 to 60.7% of the culture on day 58. Expansion of the BV17 subfamily was due predominantly to the expansion of the CO-4 clone. This method can be used to meaningfully quantify the precursor frequency of T cell mRNA in prepared samples via TCR subfamily or TCR sequence specific primers.

Stimulation of Plasmodium falciparum gametocytogenesis by conditioned medium from parasite cultures.

Plasmodium falciparum gametocyte development was examined in erythrocyte monolayer cultures prepared with Cell-Tak, a cell and tissue adhesive. The monolayers, which were stable for up to 10 days in culture, supported multiple cycles of asexual growth and the development of clusters of stage IV gametocytes. Small numbers of chicken erythrocytes incorporated into the monolayers served as internal reference standards for parasite counts. This permitted quantitative assessment of gametocyte formation under different culture conditions. Gametocyte formation was limited in monolayers grown in standard culture medium but it increased slightly in monolayers cocultured with suspensions of parasitized erythrocytes. The number of gametocytes increased significantly in monolayers grown in parasite-conditioned medium. In both cases the changes resulted from increased numbers of stage II and III gametocytes in the monolayers. These results suggest that parasite conditioned medium contains a factor(s) that stimulates sexual development.

Modification of the ferrozine technique to analyze iron contents in different foods: comparative study using an internal standard as reference methodology.

A methodology for the determination of iron in foods fortified with this element or in nutritional products is important and has to be sensitive and rapid. In developing countries, an inexpensive and reliable methodology is also required. For this purpose, the Gordon's Ferrozine technique was slightly modified and assayed with yogurt, dry powdered milk, and cereal mixtures, all of them fortified with iron, using an internal standard as the reference methodology. The obtained results demonstrate a close correlation between the standard curve interpolation method and the internal standard reference method (correlation coefficient r2 = 0.9950) in a wide range of concentrations. The slope (0.9998+/-0.0040) demonstrates that both procedures measure equal amounts of iron. The conclusion is that the proposed technique is a reliable, practical, and inexpensive methodology for iron determination in different foods fortified with iron.

Macrophage-derived Chemokine Is a Functional Ligand for the CC Chemokine Receptor 4

Macrophage-derived chemokine (MDC) is a recently identified member of the CC chemokine family. MDC is not closely related to other chemokines, sharing most similarity with thymus- and activation-regulated chemokine (TARC), which contains 37% identical amino acids. Both chemokines are highly expressed in the thymus, with little expression seen in other tissues. In addition, the genes for MDC and TARC are encoded by human chromosome 16. To explore this relationship in greater detail, we have more precisely localized the MDC gene to chromosome 16q13, the same position reported for the TARC gene. We have also examined the interaction of MDC with CC chemokine receptor 4 (CCR4), recently shown to be a receptor for TARC. Using a fusion protein of MDC with secreted alkaline phosphatase, we observed high affinity binding of MDC-secreted alkaline phosphatase to CCR4-transfected L1.2 cells (Kd = 0.18 nM). MDC and TARC competed for binding to CCR4, while no binding competition was observed for six other chemokines (MCP-1, MCP-3, MCP-4, RANTES (regulated on activation normal T cell expressed and secreted), macrophage inflammatory protein-1 alpha, macrophage inflammatory protein-1 beta). MDC was tested for calcium mobilization in L1.2 cells tranfected with seven different CC chemokine receptors. MDC induced a calcium flux in CCR4-transfected cells, but other receptors did not respond to MDC. TARC, which also induced calcium mobilization in CCR4 transfectants, was unable to desensitize the response to MDC. In contrast, MDC fully desensitized a subsequent response to TARC. Both MDC and TARC functioned as chemoattractants for CCR4 transfectants, confirming that MDC is also a functional ligand for CCR4. Since MDC and TARC are both expressed in the thymus, one role for these chemokines may be to attract CCR4-bearing thymocytes in the process of T cell education and differentiation.

Editorial

CytometryVolume 29, Issue 4 p. xii-xv Free Access Editorial First published: 06 December 1998 https://doi.org/10.1002/(SICI)1097-0320(19971201)29:4<XII::AID-CYTO1>3.0.CO;2-2Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Literature Cited 1 The Third Engineering Foundation Conference on Automatic Cytology. (Mayall BH, Ed). J Histochem Cytochem 22: 451– 765, 1974. 2 The Fourth Engineering Foundation Conference on Automatic Cytology. (Mayall BH, Ed). J Histochem Cytochem 24: 1– 411, 1976. 3 The Fifth Engineering Foundation Conference on Automatic Cytology. (Mayall BH, Ed). J Histochem Cytochem 25: 479– 951, 1977. 4 The Sixth Engineering Foundation Conference on Automated Cytology. (Mayall BH, Gledhill BL, Eds). J Histochem Cytochem 27: 1– 641, 1979. 5 Mayall BH: Editorial. Cytometry 1: 1, 1980. 6 Vindelov LL, Christensen IJ, Nissen NI: A detergent-trypsin method for the preparation of nuclei for flow cytometric DNA analysis. Cytometry 3: 323– 327, 1983. 7 Hiddemann W, Schumann J, Andreeff M, Barlogie B, Herman C, Leif R, Mayall B, Murphy R, Sandberg A: Convention on nomenclature for DNA cytometry. Cytometry 5: 445– 446, 1984. 8 Hedley DW, Friedlander ML, Taylor IW: Application of DNA flow cytometry to paraffin-embedded archival material for the study of aneuploidy and its clinical significance. Cytometry 6: 327– 333, 1985. 9 Begg AC, McNally NJ, Shrieve DC, Karcher H: A method to measure the duration of DNA synthesis and the potential doubling time from a single sample. Cytometry 6: 620– 626, 1985. 10 Vindelov LL, Christensen IJ, Nissen NI: Standardization of highresolution flow cytometric DNA analysis by the simultaneous use of chicken and trout red blood cells as internal reference standards. Cytometry 3: 328– 331, 1983. 11 Darzynkiewicz Z, Traganos F, Melamed MR: New cell cycle compartments identified by multiparameter flow cytometry. Cytometry 1: 98– 108, 1980. 12 Darzynkiewicz Z, Bruno S, Del Bino G, Gorczyca W, Hotz MA, Lassota P, Traganos F: Features of apoptotic cells measured by flow cytometry. Cytometry 13: 795– 808, 1992. 13 Cornelisse CJ, van de Velde CJ, Caspers RJ, Moolenaar AJ, Hermans J: DNA ploidy and survival in breast cancer patients. Cytometry 8: 225– 234, 1987. 14 Schutte B, Reynders MM, Bosman FT, Blijham GH: Flow cytometric determination of DNA ploidy level in nuclei isolated from paraffinembedded tissue. Cytometry 6: 26– 30, 1985. 15 Ewers SB, Langstrom E, Baldetorp B, Killander D: Flow-cytometric DNA analysis in primary breast carcinomas and clinicopathological correlations. Cytometry 5: 408– 419, 1984. 16 Bennington JL, Mayall BH: DNA cytometry on four-micrometer sections of paraffin-embedded human renal adenocarcinomas and adenomas. Cytometry 4: 31– 39, 1983. 17 Kerker M: Paul Mullaney Memorial Lecture: Elastic and inelastic light scattering in flow cytometry. Cytometry 4: 1– 10, 1983. 18 Dedicated to Torbjörn O. Caspersson (Gledhill BL, Auer GU, Eds). Cytometry 5: 313– 444, 1984. 19 Monoclonal Antibodies against Bromodeoxyuridine (Gray JW, Ed). Cytometry 6: 499– 662, 1985. 20 Cytometry in the Aquatic Sciences (Yentsch CM, Horan PK, Eds). Cytometry 10: 497– 669, 1989. 21 Analytical Cytogenetics, Dedicated to Samuel A. Latt (Gray JW, van der Ploeg M, Eds). Cytometry 11: 1– 218, 1990. 22 Optical Trapping (Mayall BH, Ed). Cytometry 12: 479– 510, 1991. 23 DNA Cytometry Consensus Conference (Hedley DW, Shankey TV, Wheeless LL, Eds). Cytometry 14: 471– 500, 1993. 24 Cytometry for CGH (Raap AK, Ed). Cytometry 19: 1– 50, 1995. 25 Tumor Heterogeneity (Shankey TV, Shackney SE, Eds). Cytometry 21: 1– 75, 1995. Citing Literature Volume29, Issue41 December 1997Pages xii-xv ReferencesRelatedInformation