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S S West

Publications and source records attributed to S S West.

15 recordsLinked to original sources
PubMed1986

Improved nuclear fluorescence screening technique.

Three separate screening studies have tested the sensitivity and specificity of quantitative fluorescence image analysis for detecting bladder cancer. Nuclear intensity (NI) measurements of fluorescent dye-stained epithelial cells from voided urine and bladder washings were compared with routine Papanicolaou (Pap) cytology results, and findings were verified against pathological biopsy diagnoses. The NI cytology method detected the pathologically confirmed tumors earlier and with greater specificity than did conventional cytology. In the study of 140 clinically symptomatic patients in Oklahoma, the NI method detected 91.1% (31 of 34) of the pathologically confirmed grades 1 and 2 tumors and 100% of 18 grades 3 and 4 tumors. Pap cytology detected only 47% (16 of 34) of low-grade and 78% (14 of 18) of high-grade tumors. Comparable results were obtained in a study of symptomatic patients in Mississippi and the method has been employed in the screening of a high-risk occupationally exposed cohort in Georgia.

2-Naphthylamine↗
PubMed1985

Risk assessment of a cohort exposed to aromatic amines. Initial results.

A cohort of 1,385 workers potentially exposed to carcinogenic amines was evaluated to determine the extent of its risk for bladder cancer. The cumulative incidence of bladder cancer was determined from death certificates, from interviews with community urologists, and from a screening program. A total of 13 confirmed cases of bladder cancer were identified at the conclusion of the first year of study. The entire cohort has approximately a fourfold excess risk of bladder cancer; however, black workers with more than 10 years of employment had a risk ratio of 111 (based on three cases). The onset of disease occurred, on the average, 15 years earlier in these black workers than in the general U.S. population. The cumulative incidence of bladder cancer increased with the duration of employment, ranging from 0.4% for workers with five or fewer years of employment to 36% for those with greater than 20 years. No significant differences were found between cases and noncases for cigarette smoking, coffee drinking, use of artificial sweeteners, or prior employment in high-risk occupations. More cases of bladder cancer are expected in this cohort because many members have not yet achieved the average latency found for the confirmed cases.

Adolescent↗
PubMed1979

Structural basis for the anticoagulant activity of heparin. 1. Relationship to the number of charged groups.

This study was undertaken to provide further information concerning the chemical heterogeneity of heparins and the relationships between the anticoagulant activity (USP assay) and the anionic density of the heparin. A sample of commercial heparin was fractionated into 13 fractions by sequential extraction in a two-phase system of 1-butanol-aqueous NaCl containing excess hexadecylpyridinium chloride. The anionic density distribution was characterized by the fractional distribution of uronate among the fractions. The fractions were characterized by several molar ratios of constituents, molecular weight, charge density, and anticoagulant activity in recalcified sheep plasma. The heparin was broadly distributed among the last 10 fractions; the first three contained impurities which were completely separated from the heparin fractions. The heparin fractions differ systematically in anionic density but are of substantially the same molecular weight. Anticoagulant activity increased markedly with anionic density, ranging from 81 units/mg for the heparin fraction with the lowest anionic density up to a high of 243 units/mg. The relationship between anticoagulant activity and either anionic density or its square is nonlinear. However, in the latter case an initial linear relationship was observed for anticoagulant activities of less than 200 units/mg.

Animals↗
PubMed1979

Structural basis for the anticoagulant activity of heparin. 2. Relationship of anticoagulant activity to the thermodynamics and fluorescence fading kinetics of acridine orange-heparin complexes.

Complexing heparin or dermatan sulfate with the fluorescent probe acridine orange provides a means of studying electrostatic as well as static and dynamic conformational aspects of these glycosaminoglycans via the thermodynamic and photochemical (fluorescence fading) properties of these complexes. The cooperative binding constants (Kq), fluorescence fading rate parameters (r''), and anticoagulant activities of heparins fractionated according to anionic density all showed qualitatively the same dependence upon anionic density. When Kq and r'' were plotted against anticoagulant activity, empirical relationships were observed. Interestingly, the corresponding values for unfractionated dermatan sulfate fell on the lines defined by the heparin fractions. Temperature-dependence, studies demonstrated that differences in fading rate observed for heparins of different anionic densities are entropic in origin and reflect differences in the ability to assume a special configuration. Differences in activation entropy for fluorescence fading can be empirically correlated with anticoagulant activity. The latter correlation suggests a physical similarity in the roles played by anionic density in both fluorescence fading and anticoagulant activity.

Acridine Orange↗
PubMed1979

A screening system for cervical cancer cytology.

A system for screening cervical cytological preparations is described which employs the Leitz Texture Analyzer System (E. Leitz, Rockleigh, N. J.) quantitative staining with acridine orange, and a fluorescence standard. The instrumentation scans cells on microscope slides and detects objects which it interprets to be nuclei with excess total nuclear green fluorescence intensity (Previous results employing manual measurements have indicated that normal nuclei do not produce total nuclear green fluorescence greater than a specific absolute intensity level). Detected objects are identified by visual observation. Cells (102,000) from 65 patients (29 normal, 36 abnormal) have been examined. In each abnormal sample, at least one abnormal cell was detected. In over half of the samples, three or fewer other objects (e.g. clumps of polymorphonuclear leukocytes) were detected. These are easily distinguishable from single nuclei, and could be discarded by someone with minimal cytological training.

Cervix Uteri↗
PubMed1979

Automatic cell identification and enrichment in lung cancer. II. Acridine orange for cell sorting of sputum.

Fluorescence spectra were obtained from cells from sputum and pleural effusions stained with different fluorescent dyes and fixed by alternate methods. The spectra were referenced to a standard allowing for fluorescence comparisons of unstained and stained cells under various conditions. The metachromasia of acridine orange-stained cells offers nuclear/cytoplasmic differentiation in a single stain; mithramycin and propidium iodide do not. Unstained cells have an appreciable amount of green (546 nm) fluorescence, as does Carbowax in Saccomanno's preservative. Cytoplasm stained with acidine orange also has appreciable green fluorescence. Consequently, cells with much cytoplasm have high total fluorescence. Cytoplasmic fluorescence is negligible with mithramycin or propidium iodide. The metachromasia of acridine orange-stained cells is altered by alcohol and Carbowax levels in fixatives, keeping other factors constant.

Acridine Orange↗
PubMed1978

Biochemical composition and heterogeneity of heparan sulfates isolated from AH-130 ascites hepatoma cells and fluid.

The glycosaminoglycan composition of AH-130 ascites hepatoma cells and fluid were examined using enzymatic digestion, electrophoresis, and sequential partition fractionation. The cell-associated glycosaminoglycans were found to consist of 93% heparan sulfate, with the remainder consisting primarily of chondroitin sulfate. The glycosaminoglycans isolated from the ascitic fluid were found to consist of 58% heparan sulfate, 26% hyaluronic acid and 16% chondroitin sulfate. Dermatan sulfate was not detected in either cells or fluid. The heparan sulfate isolated from AH-130 cells in low-sulfate and highly heterogeneous with respect to biochemical composition. Fractions isolated by partition fractionation varied from 0.14 mol sulfate/mol uronic acid to 0.6 mol sulfate/mol uronic acid. Of the total sulfate 70--80% is N-sulfate in the former and 50% in the latter. Electrophoresis in 0.1 M HCl showed a highly heterogeneous material with mobility between that of hyaluronic acid and beef lung heparan sulfate. The heparan sulfate isolated from the fluid was similar to that isolated from the cells but was, however, somewhat more homogeneous with respect to charge.

Animals↗
PubMed1978

Isolation and characterization of glycosaminoglycans from the Furth murine mastocytoma.

New methods for isolation and fractionation by partition are described and compared with existing techniques. Substantially purer products were isolated by partition as compared to precipitation with hexadecylpyridinium chloride. The glycosaminoglycans isolated fron Furth murine mastocytoma tumor were found to consist of 78-80% heparin, 12-13% chondroitin sulfate, and 8-9% hyaluronate. Dermatan sulfate was not detected. Two heparin-like glycosaminoglycans could be isolated by partition fractionation in the phase system 1-butanol/aqueous NaCl containing hexadecylpyridinium chloride. The composition of one was typical of heparins. However, the other glycosaminoglycan contained only 0.47 moles N-sulfate/mole uronate, but had electrophoretic and partition properties characteristic of heparin.

Animals↗
PubMed1976

Quantitation of fluorescence fading phenomena for identifying intracellular biopolymers.

The fading behavior of the 670 nm fluorescence emission band produced by unfixed rat mast cells stained with acridine orange (AO) has been found to be in excellent agreement with the behavior predicted by second order chemical kinetics. The reciprocal of fluorescence intensity plotted against time yields a straight line. When due account is taken of dye/cell ratio and the intensity of fluorescence-exciting radiation, Io (measured with the standard phosphor particle), the slope of this straight line is a constant, k'', which is independent of dye/cell ratio and Io. k'' differs from the second order photochemical rate constant by a constant factor. The fading of a given AO-biopolymer complex is described by a particular value of k''. Two values of k'' have been found for rat mast cell granules, indicating the presence of two different AO-biopolymer complexes. Fading of fluorescence may serve to identify particular intracellular biopolymers in individual cells even when present in a heterogeneous population.

Acridines↗
PubMed1976

Quantitative fluorescence spectrophotometry of acridine orange-stained unfixed cells. Potential for automated detection of human uterine cancer.

After staining with acridine orange (AO), the nuclei of unfixed cells from the human female genital tract exhibited the same fluorescence behavior previously observed for human and murine leukocytes and mouse ascites tumor cells. With staining conditions chosen to assure saturation of the green-fluorescing AO-nucleic acid complex in normal cells, corrected fluorescence emission spectra were recorded from the entire nucleus of 341 cells taken from 32 normal and 28 abnormal patients. Intensity of the recorded spectra was expressed in phosphor particle units, a fixed arbitrary unit of fluorescence intensity, to display intensity differences among the spectra from the various cell types. In all abnormal samples, one or more cells were found with 530-nm nuclear fluorescence intensity considerably greater than the maximum intensity recorded from normal cells. Determination of the adequacy of 530-nm nuclear fluorescence intensity as a criterion for cancer detection requires additional investigation. Additional criteria, if needed, may be supplied by the metachromasy of AO-stained unfixed cells.

Acridines↗