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J W Bacus

Publications and source records attributed to J W Bacus.

At least 19 recordsLinked to original sources
PubMed1990

Comparison of the Papanicolaou and Feulgen staining methods for DNA quantification by image analysis.

The possibility of using archival cytology material to study the evolution of neoplastic disease with regard to DNA content abnormalities was investigated. The accuracy of measuring the integrity optical density (OD) of nuclei that correlates to DNA amounts of those nuclei, on slides stained by the Papanicolaou method, was assessed and compared with a standard Feulgen method. Our data on rat liver nuclei peritoneal washings from patients with ovarian cystadenofibromas and ovarian cystadenocarcinomas suggested that analysis of cytological material using the Papanicolaou method is not reliable and that destaining the slides followed by Feulgen staining provides an optimal and reliable method of DNA quantification.

Adenofibroma↗
PubMed1990

HER-2/neu oncogene expression and DNA ploidy analysis in breast cancer.

This study was performed to evaluate the correlation between HER-2/neu gene expression and DNA ploidy patterns. Forty-five cases of breast-cancer were analyzed. Immunohistochemical staining of HER-2/neu protein on frozen sections was used to detect the HER-2/neu protein, and the Feulgen DNA staining method was used to assess DNA amounts in the same tumor cells. Positive HER-2/neu overexpression was evaluated visually, and quantitation of the HER-2/neu protein was measured by image analysis. Twenty-two of the 45 cases were visually scored to be positive for the overexpression of the HER-2/neu protein, and these cases also contained above 10% HER-2/neu protein compared with a standard control cell line. All 22 of these cases had near-tetraploid DNA content. In contrast, cells, derived from the 23 cases that did not overexpress the HER-2/neu protein, contained DNA amounts that ranged from euploid (diploid) to varying degrees of aneuploid. The results of this study indicated that tumors that overexpress the HER-2/neu protein have tetraploid or near-tetraploid DNA content. This pattern could relate to the biological behavior of these tumors.

Adenocarcinoma↗
PubMed1990

HER-2/neu oncogene expression and proliferation in breast cancers.

Amplification of the HER-2/neu proto-oncogene in breast cancer has been reported to correlate with poor patient prognosis. The proliferation, or growth fraction, of cells has also been shown to be of prognostic importance in breast cancer. A study was conducted to evaluate the correlation between HER-2/neu gene expression and proliferation in breast cancer. Quantitative immunohistochemical methods for the detection of the HER-2/neu protein expression and for assessing the proliferation fraction on frozen sections of tumor cells were used. The detection of epidermal growth factor receptor (EGFR) along with quantitative DNA ploidy analysis, also was performed on the same breast cancers. The results indicated two subgroups of invasive ductal carcinoma; 1) HER-2/neu overexpressing cases that were negative for EGFR expression and had low proliferation fraction, and a tetraploid DNA pattern (22 cases), and 2) other combinations of HER-2/neu expression and EGFR expression, with a high proliferation fraction and an aneuploid DNA pattern (38 cases). Eight cases of carcinoma in situ were positive for HER-2/neu overexpression and negative for EGFR expression, and had a high proliferation fraction and a tetraploid DNA pattern. Twenty-six cases of low-grade carcinoma exhibited low proliferation and a diploid DNA pattern.

Breast Neoplasms↗
PubMed1989

Biological grading of breast cancer using antibodies to proliferating cells and other markers.

Quantitation of immunohistochemical staining by image analysis was performed on 50 breast cancers stained with the monoclonal antibody Ki-67 to determine the growth fraction and its correlation with tumor grade. A high degree of correlation was shown. For each case the DNA ploidy was determined by quantitation of the DNA Feulgen stain by computerized microdensitometry. DNA content of breast tumor cells correlated to the histopathologic grade at which poorly differentiated tumors are more likely to be aneuploid. Quantitation of immunohistochemistry for estrogen and progesterone receptors had a high degree of correlation with the steroid binding assay, such as dextran-coated charcoal assay (DCCA), and were weakly correlated to histologic grade. In summary, our results indicated that quantitation of Ki-67-positive nuclear area and of DNA content by image analysis provides an objective method for assessing tumor cell growth fraction and DNA ploidy. Quantitation of steroid receptors by immunohistochemistry is a better and easier technique than those currently used to determine the best therapy for postmenopausal women. These methods can be performed on small frozen sections or needle aspirates in quantities that are insufficient for current steroid binding assays. Thus, this method is prognosticly useful even for patients with small breast lesions.

Antibodies, Monoclonal↗
PubMed1988

The evaluation of estrogen receptor in primary breast carcinoma by computer-assisted image analysis.

A monoclonal antibody prepared against estrogen receptor has been shown to be specific and sensitive for the detection of estrogen receptor in human breast lesions by use of immunohistochemical methods. Two hundred selected cases of primary breast carcinoma were assayed for estrogen receptor content by biochemical and immunohistochemical procedures. Quantitative evaluation was by biochemical, immunohistochemical, and automated computer-assisted image analysis using the Cell Analysis System's CAS/100 machine (Lombard, IL). Quantitative estrogen receptor content was determined by dextran-coated charcoal analysis and sucrose density gradient analysis. Immunohistochemical evaluation incorporated both intensity and distribution of staining, yielding a subjective score, histologic score (HSCORE). An objective quantitation, also incorporating intensity and distribution of staining, was done by computer-assisted image analysis, quantitative immunocytochemical score (QIC SCORE). HSCORE analysis was done with and without methyl green counterstain with no loss of sensitivity. Comparison of QIC SCORE with the biochemical and immunohistochemical analysis of the tissues examined revealed excellent sensitivities and specificities. These data suggest that automated image analysis provides an effective qualitative and quantitative means of evaluating estrogen receptor content in human breast cancers.

Antibodies, Monoclonal↗
PubMed1984

The brain as a sponge: a computed tomographic look at Hakim's hypothesis.

Hakim's hypothesis, which explains the brain's adaptation to pressure in hydrocephalus and the enlargement of ventricular volume, was studied with computed tomographic (CT) scanning. The critical element in the theory is that brain water decreases when there is a pressure gradient within brain tissue. Extraaxial hematomas uniformly increase the CT density of adjacent brain tissue, and this is best explained by water shifts out of the tissue. In hydrocephalus cases studied early after shunting (10 days or less), a decrease in ventricular volume is accompanied by an overall decrease in the CT density of the brain. These CT changes support Hakim's view of the brain as a sponge that can change its hydration under pathological conditions.

Brain↗
PubMed1984

Scene-segmentation algorithm development using error measures.

Development of scene-segmentation algorithms has generally been an ad hoc process. This paper presents a systematic technique for developing these algorithms using error-measure minimization. If scene segmentation is regarded as a problem of pixel classification whereby each pixel of a scene is assigned to a particular object class, development of a scene-segmentation algorithm becomes primarily a process of feature selection. In this study, four methods of feature selection were used to develop segmentation techniques for cervical cytology images: (1) random selection, (2) manual selection (best features in the subjective judgment of the investigator), (3) eigenvector selection (ranking features according to the largest contribution to each eigenvector of the feature covariance matrix) and (4) selection using the scene-segmentation error measure A2. Four features were selected by each method from a universe of 35 features consisting of gray level, color, texture and special pixel neighborhood features in 40 cervical cytology images . Evaluation of the results was done with a composite of the scene-segmentation error measure A2, which depends on the percentage of scenes with measurable error, the agreement of pixel class proportions, the agreement of number of objects for each pixel class and the distance of each misclassified pixel to the nearest pixel of the misclassified class. Results indicate that random and eigenvector feature selection were the poorest methods, manual feature selection somewhat better and error-measure feature selection best. The error-measure feature selection method provides a useful, systematic method of developing and evaluating scene-segmentation algorithms.

Computers↗
PubMed1984

Malignant cell detection and cervical cancer screening.

A study was conducted to determine the isolated, single-cell detection characteristics of human observers as this information relates to cervical cancer screening. Two interrelated experiments were performed. First, the receiver operating characteristic (ROC) was obtained for slide screening. In this experiment, approximately 1,200 slides were examined. Second, ROCs were obtained for human observer cell discrimination, using a rating method. An individual's curves were computed, assuming a multiple decision criterion. In this experiment, 6,375 cells from the same specimens used in the slide screening experiment were studied. In both experiments, results were analyzed using a Gaussian signal-detection model. This approach provided analytical detection criteria and rigorous definition of ROCs. These experiments addressed the problem of where the screening information lies: (1) in individual cells alone or (2) with additional components in global or other a priori information. We quantified the detection requirements of (1) the Papanicolaou smear screening process, Az = 0.99, and (2) the capabilities of trained cytotechnologists on isolated single cells, Az = 0.87. System modeling using intermediate cell detection instead of "rare event" detection resulted in a reduction of the predicted number of cells required for analysis from approximately 60,000 to 750.

Female↗
PubMed1983

Red blood cell morphology in sickle cell anemia as determined by image processing analysis: the relationship to painful crises.

Red blood cell morphology was studied in the peripheral blood of adults with sickle cell anemia to determine if changes occur during painful crises. Image processing of the cells with an automated system of red blood cell analysis was used. Four groups of cells were observed: normocytes, macrocytes, target cells, and cells with the shape of irreversibly sickled cells. During asymptomatic periods, the percentages of these cells differed in each individual but were typical for that individual and generally were stable. During crises, macrocytosis occurred and the concentration of irreversibly sickled cells showed greater fluctuation. The macrocytosis most likely reflected a marrow response to increased hemolysis and demonstrated that the increased red blood cell destruction observed during pain crises may be more extensive than previously considered. Changes in the concentration of irreversibly sickled cells during crises were not consistent and could not be used as an indicator of a crisis. Image processing with automated red blood cell analysis allows for accurate assessment of all the morphologic groups of red blood cells in patients with sickle cell anemia and compares well with standard methods for measuring the concentration of irreversibly sickled cells.

Adult↗
PubMed1981

Microspectrophotometric studies of Romanowsky stained blood cells. II. Comparison of the performance of two standardized stains.

This paper describes a comparison of the performance of two standardized Romanowsky blood stains, namely those of Marshall et al. and Wittekind et al., both containing azure B and eosin alone. Stain performance is assessed objectively by the use of three complementary techniques, all based on the visible absorbance spectra of stained cellular substrates. The first of these techniques is a simple comparison of the shapes and heights of the absorbance spectra. The second technique uses the CIE Colorimetric System, and thus permits the quantitation of colour in a manner that agrees with human observation. CIE co-ordinates (chromaticity points, luminance) are calculated directly from absorbance spectra. The third technique is that of spectral subtraction, which yields a set of factors which describe the quantities of component dyes which are bound by the object. This technique, unlike the other two, requires a priori knowledge of the dyes used in the stains, and their spectra when bound to cellular substrates. Although the differences between the two methods are subtle, and hard for the subjective observer to define, the objective methods described here do show statistically significant differences. Wittekind's stain produces less intense staining, except for lymphocyte and monocyte cytoplasms. To the human eye, the differential coloration of these two substrates is more pronounced, but the difference between all nuclei and cytoplasm is less marked. The major difference in the uptake of dye components is in the small quantities of eosin dimer that are bound in this technique.

Blood Cells↗
PubMed1980

Assessment of the anemia of chronic disease by digital image processing of erythrocytes.

Eighteen patients with the anemia of chronic disease were studied to determine the usefulness and accuracy of image processing analysis of erythrocytes for diagnosis. Diagnostic tests used for comparison included estimates of serum ferritin, serum iron and iron-binding capacity, stainable marrow iron, and erythrocyte morphology as determined by standard methods. The findings show that the analyses obtained by image processing were diagnostic for 83% of the patients with chronic disease. Serum ferritin levels were supportive of diagnosis for 33% of the patients, and serum iron levels were useful for approximately 25% of the patients. Cell indices and marrow iron were of limited value. The study demonstrates that quantitative information obtained by digital image processing of erythrocytes can be very useful for the diagnosis of the anemia of chronic disease.

Anemia↗
PubMed1980

Microspectrophotometric studies of Romanowsky stained blood cells. I. Subtraction analysis of a standardized procedure.

This paper describes a microspectrophotometric study of blood smears stained by a simple, standardized Romanowsky technique, using only the dyes azure B and cosin. Absorbance spectra are presented for twenty-two classes of cellular object, and for the two dyes in solution, together with tabulations of spectral maxima, and suitable wavelengths for use in automated image processing. The colours of objects stained with azure B/eosin are discussed in terms of absorbance spectra. By a spectral subtraction technique, it is shown that the differential colouration of various cell structures may be explained satisfactorily in terms of the varying proportions of only four dye components. These are the monomers and dimers of azure B and eosin. Polymerization was found to occur both in solution and on binding to biopolymers. A similar analysis of a conventional Romanowsky stain would present much greater difficulties, due to the greater number of dye components, which, however, contribute little to the colours observed.

Azure Stains↗
PubMed1980

Quantitative measurement of red blood cell central pallor and hypochromasia.

A quantitataive definition and techniques of measurement for central pallor of red blood cells are proposed. These are based on high-resolution measurements of absorbance across the center of the cell. Thus, the measurements reflect both variations in cell thickness and hemoglobin concentration. Although contributions of thickness and concentration may differ in individual cells, to a first approximation, a specific cell may be considered as having a similar concentration of hemoglobin throughout, and thus the major contribution to the central pallor is that due to the difference in thickness between the edges of the cell and the center. The definition proposed expresses central pallor as the percentage volume of indentation, comparing the red cell to a disc of uniform absorbance equal to the maximum found at the cell edges. Population distributions of central pallor then provide a basis for quantitation of hypochromasia. The mean and standard deviation of such distributions are proposed as quantitative descriptors. Sample distributions from 27 normal persons, 8 patients with spherocytic anemia and 26 patients with iron deficiency anemia were studied.

Anemia, Hypochromic↗
PubMed1980

Quantitative morphological analysis of red blood cells.

Recently developed methods for making quantitative measurements of red cell morphology are described. High-speed image processing is used to make six simultaneous red cell measurements relating to size, hemoglobin content, central pallor, and shape. These measurements are combined objectively to subdivide red cells into five subpopulations and to characterize each subpopulation by its principal distributional parameters. Also, an objective assessment of the blood sample is made relative to the diagnosis of anemia. Results from five typically encountered blood conditions are presented and analyzed in detail to illustrate the various distributional parameters involved and to illustrate the potential of these new measurements to extract relevant diagnostic information.

Anemia↗
PubMed1979

Automated scene analysis of CT scans.

Since the advent of computed tomography, there has been an increasing realization that CT scans contain quantitative as well as qualitative information useful in the diagnostic process. Often however, the use of this information is impeded by the tedious manual outlining of the areas of interest in the scan. To alleviate this problem, we have developed a scene segmentation algorithm which will automatically delineate areas of interest in a CT scan. This procedure uses known information about the expected objects in the scan in conjuction with an algorithm to label those objects. The resultant scene segmentation divides the scan into four anatomical areas: skull, normal brain, high density lesions and CSF. After an area of interest is interactively selected by the clinician, volume, density or other quantitative measures may be computed. Limitations of the algorithm and its clinical applications are discussed.

Absorptiometry, Photon↗
PubMed1977

An automated method of differential red blood cell classification with application to the diagnosis of anemia.

A method of automated red cell analysis suitable for the rapid classification of large numbers of red cells from individual blood specimens has been developed, and preliminarily tested on normal bloods and clinically proven cases of anemias and red cell disorders. According to this method digital image processing techniques provide several features relating to shape and internal central pallor configurations of red cells. These features are used with a fully automated decision logic to rapidly provide a quantitative "red cell differential" analysis, a report of the percentage subpopulations of recognized categories of red cells. For each subpopulation, measurements of mean cell area, mean cell hemoglobin content and mean cell hemoglobin density are provided. The nine types of red cell disorders studied with this method were: (a) iron deficiency anemia, (b) the anemia of chronic disease, (c) beta-thalassemia trait, (d) sickle cell anemia, (e) hemoglobin C disease, (f) intravascular hemolysis, (g) hereditary elliptocytosis, (h) hereditary spherocytosis, and (i) megaloblastic anemia due to folic acid deficiency. Preliminary indications are that the red cell differential is useful in distinguishing between these conditions.

Anemia↗