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J S Coon

Publications and source records attributed to J S Coon.

At least 37 records · Page 2Linked to original sources
PubMed1995

Detection of tumor cells in the bone marrow, peripheral blood, and apheresis products of breast cancer patients using flow cytometry.

One of the possible drawbacks to autologous bone marrow (BM) and peripheral blood progenitor cell (PBPC) transplantation in breast cancer patients is the potential for tumor cell contamination in the transplanted product. To assess the presence of breast cancer cells, we have developed a flow-cytometric method using cytokeratin-FITC and CD45-phycoerythrin (PE) to detect very low levels of cytokeratin-positive (CK+) tumor cells in mononuclear cell (MNC) preparations. In a model system using PBMNC and the breast cancer cell line CAMA, the sensitivity of detection of this flow-cytometric method was one tumor cell in 200,000 MNC. This method was used to evaluate BM, PB, and apheresis products (AP) from 44 patients with metastatic breast cancer. When possible, stained cytologic examination was performed on smears of the unprocessed specimens and on flow cytometry-sorted cells. Results indicated that CK+ tumor cells could be detected by flow cytometry in all three specimen types. When present, however, the tumor content (per MNC) tended to be higher in BM than in PB or AP. Samples from a given patient taken serially over the course of chemotherapy revealed variable results, suggesting that the presence of tumor contamination may be sporadic and requires evaluation of each stem cell product. Of 75 samples tested with both flow cytometry and cytology, the results were concordant in 54 cases (72%). In the remaining samples, flow cytometry only was positive in 15 cases (20%), and cytology only was positive in six cases (8%). This flow-cytometric technique is useful in the evaluation of transplant products for CK+ tumor cell contamination.

Adenocarcinoma↗
PubMed1994

PCR production of a digoxigenin-labeled probe for the detection of human cytomegalovirus in tissue sections.

In situ hybridization (ISH) provides a means for identifying viral genomes in the context of tissue pathology. We have developed a specific and sensitive ISH probe for the detection of cytomegalovirus (CMV) DNA in formalin-fixed, paraffin-embedded tissue sections. Digoxigenin-11-dUTP was incorporated into a 435-base pair fragment of the CMV Major Immediate Early (MIE) gene with use of the polymerase chain reaction (PCR). Hybridized probe was detected by reaction with antidigoxigenin antibody coupled to alkaline phosphatase and chromogenic substrates. This method has detected CMV infection in routine clinical specimens from a variety of tissue types, including colon, kidney, liver, and stomach. Infection in cells with and without characteristic inclusions is revealed with this probe. The background is so low that single infected cells are detected unambiguously. No cross-hybridization was observed with cells infected with other viruses of Herpesviridae. This approach may be useful for producing probes for the detection of other viral genomes in tissue sections.

Base Sequence↗
PubMed1994

Interlaboratory variation in DNA flow cytometry. Results of the College of American Pathologists' Survey.

The results of the DNA Analysis Module of the College of American Pathologists' Flow Cytometry Survey were analyzed to determine if participating laboratories could correctly identify aneuploid populations and estimate S-phase fraction reproducibly in proficiency specimens. Each survey contained three specimens: a diploid calibrator and two unknowns comprising cultured aneuploid tumor cells with DNA indexes of 1.2 to 2.0 admixed with normal lymphocytes. Results of ploidy analysis were obtained from a mean of 241 participants on 19 unknowns from 1990 to 1992. Most laboratories correctly reported the modal (and intended) number of aneuploid peaks; the proportion of correct responses ranged from 58% to 97%, with a mean of 86%. The lower percents of correct response were associated with near-diploid and tetraploid unknowns. Some laboratories showed consistent deviations from the mean for DNA index, indicating apparent instrument linearity problems. S-phase results on five specimens showed wide interlaboratory variability, although the means of participants' responses were close to the reference values obtained by the specimen provider.

DNA, Neoplasm↗
PubMed1993

Variable effects of sodium butyrate on the expression and function of the MDR1 (P-glycoprotein) gene in colon carcinoma cell lines.

Expression of the MDR1 (P-glycoprotein) gene confers resistance to several classes of chemotherapeutic drugs (multi-drug resistance). Colon carcinomas frequently express high levels of MDR1 mRNA and P-glycoprotein, presumably reflecting the origin of these tumors from MDR1-expressing normal colonic cells. In 4 colon carcinoma cell lines (SW 620, HCT-15, DLD-1, LS 180), MDR1 expression was reported in an earlier study to be elevated after exposure to a differentiating agent, sodium butyrate (NaB). In one of these cell lines (SW 620), increased MDR1 expression reportedly was not accompanied by a decrease in the accumulation or cytotoxicity of vinblastine, a P-glycoprotein-transported drug, suggesting a possible functional abnormality of NaB-induced P-glycoprotein. We have re-examined the effect of NaB on MDR1/P-glycoprotein expression and function in the same colon carcinoma cell lines. NaB treatment induced differentiation-related changes and increased expression of MDR1 mRNA in all 4 cell lines. A major increase in MDR1 mRNA and P-glycoprotein expression was observed in only one line, SW 620. This increase, however, was accompanied by a commensurate increase in the activity of P-glycoprotein, indicating that the induced protein was fully functional. NaB treatment caused a relatively minor increase in MDR1 mRNA expressed in the other 3 cell lines. Two of these lines showed a detectable increase in the P-glycoprotein expression and function, but in the third line (LS 180) P-glycoprotein was undetectable either before or after exposure to NaB. The magnitude of MDR1 induction by NaB showed no apparent correlation with differentiation-related changes induced by this agent.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Diverse multidrug-resistance-modification agents inhibit cytolytic activity of natural killer cells.

Multidrug resistance (MDR) is the phenomenon in which cultured tumor cells selected for resistance to one chemotherapeutic agent simultaneously acquire resistance to several apparently unrelated drugs. MDR in tumor cells is associated with the over-expression of P-glycoprotein, an ATP-dependent cell-membrane transport molecule. P-glycoprotein is also expressed in several normal tissues but its physiological role(s) is unknown. We recently observed that a hierarchy of MDR-like activity exists among human peripheral blood lymphocytes in the order CD8 > CD4 > CD20 (cytotoxic/suppressor T cells, helper T cells and B cells respectively). In this study, we report that natural killer (NK) cells also express MDR-like activity. This activity could be inhibited with verapamil or solutol HS-15, two agents that reverse MDR in tumor cells. These, and four additional reversing agents, were used to investigate the possible role of P-glycoprotein in NK cells. We observed that at 10% of their IC50, five of six reversing agents inhibited NK-cell-mediated cytotoxicity; at higher (but non-toxic) doses, all six agents were inhibitory. These data suggest that NK-cell-mediated cytotoxicity may require the functional expression of an efflux molecule similar or identical to P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Variable expression of P-glycoprotein in normal, inflamed, and dysplastic areas in ulcerative colitis.

Screening programs for the detection of cancer in ulcerative colitis are inexact and not always successful in finding early, curable cancers. P-glycoprotein is a membrane-based, energy-dependent protein found in varying degrees within normal human tissue. P-glycoprotein is overexpressed in malignant tumors, particularly colorectal cancer, and is known to convey resistance to certain anticancer drugs by acting as a membrane "pump." The purpose of this study was to determine the expression of this protein in inflamed and premalignant colonic epithelium, compare its expression with normal controls, and assess its potential use as a screening tool for high-risk patients with ulcerative colitis. Using immunohistochemical techniques, the colons of 21 patients (10 with dysplasia) with ulcerative colitis were stained with monoclonal antibody C-219 (MAbC219) specific for P-glycoprotein. P-glycoprotein was expressed in 38 percent of normal areas, 71 percent of inflamed areas (P = 0.0156), and 70 percent of dysplastic areas. Comparing the level of expression when progressing from normal to inflamed areas within a given patient, 11 patients (52 percent) showed increased expression, 8 (38 percent) showed equal expression, and only 2 (10 percent) showed decreased expression (P = 0.0225). Comparing expression when progressing from inflamed to dysplastic areas (10 patients), 7 showed equal expression and 3 showed increased expression (P = 0.25). Increasing duration of disease was associated with a significant increase in P-glycoprotein expression, but only in histologically normal areas. Duration of disease had no effect on P-glycoprotein expression in inflamed or dysplastic areas. Similarly, when surgery was performed for elective reasons, there was a significant overexpression of P-glycoprotein, but only in histologically normal areas. Our findings suggest that the increase in P-glycoprotein expression from normal to inflamed and dysplastic areas reflects the premalignant nature of ulcerative colitis and occurs early in the course of the disease. Further research needs to be done to determine its role in cancer surveillance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Nucleolar organizer regions in squamous cell carcinoma of the head and neck.

Nucleolar organizer regions are collections of nucleolar proteins associated with ribosomal genes that can be visualized in histologic sections using a silver colloid stain, thus the term silver-staining nucleolar organizer region (AgNOR). In some tissues, the number of AgNORs per nucleus correlates with cellular proliferation and, independently, with malignant change. AgNORs were studied in 66 paraffin-embedded head and neck squamous cell carcinomas and in 12 samples of normal tonsillar squamous epithelium. Carcinomas had a significantly higher mean AgNOR count than the benign epithelium (P less than .0001). Among carcinomas, mean AgNOR count increased with stage of the disease (P less than .001), but there was no significant correlation with histologic grade or DNA ploidy as determined by flow cytometry. These data suggest that AgNOR count should be evaluated as a possible aid in differentiating benign from malignant squamous epithelial proliferations in the head and neck, and also possibly as a prognostic marker in these carcinomas.

Aneuploidy↗
PubMed1991

Solutol HS 15, nontoxic polyoxyethylene esters of 12-hydroxystearic acid, reverses multidrug resistance.

A recently developed non-ionic surfactant called Solutol HS 15 (poly-oxyethylene esters of 12-hydroxystearic acid), with low toxicity in vivo, was shown to reverse completely the multidrug resistance of KB 8-5 and KB 8-5-11 human epidermoid carcinoma cells in vitro but did not potentiate drug toxicity in drug-sensitive KB 3-1 cells. At a concentration of 10% of its own IC50 (mean concentration of drug that causes 50% inhibition of cell growth compared to controls), Solutol HS 15 produced a 35-, 28-, and 42-fold reduction in the resistance of KB 8-5-11 cells to colchicine, vinblastine, and doxorubicin, respectively. Solutol HS 15 was relatively much more potent than the prototypic reversing agent, verapamil, for reversing colchicine resistance, compared to the ability of each agent to reverse colchicine resistance, compared to the ability of each agent to reverse vinblastine resistance. Like verapamil, Solutol HS 15 promoted a 50-fold accumulation of rhodamine 123 in KB 8-5-11 cells, as measured by flow cytometry. Also, Solutol HS 15 and verapamil reduced the efflux of rhodamine 123 from KB 8-5-11 cells previously loaded with rhodamine 123 to a similar low rate. Solutol HS 15 did not affect the transport of alanine or glucose into KB 8-5-11 cells, indicating that its effect upon membrane active transport is not entirely nonspecific. Considering their different structure and different relative potency for reversing colchicine resistance, Solutol HS 15 and verapamil probably reverse multidrug resistance by different mechanisms. Solutol HS 15 merits consideration as a potential therapeutic agent because of its effectiveness for reversing multidrug resistance in vitro and its low toxicity in vivo.

Carcinoma, Squamous Cell↗
PubMed1991

Precision of DNA flow cytometry in inter-institutional analyses.

A Bladder Cancer Flow Cytometry Network study has been carried out to further identify and quantify sources of inter- and intra-laboratory variability. Replicate samples containing four mixtures of peripheral blood lymphocytes and aneuploid cell lines were distributed together with reference standards to six laboratories. The samples were stained for DNA using propidium iodide, with each laboratory using its own staining protocol. Two of each of the four sample types and a reference standard were analyzed by each laboratory on 3 separate days to obtain cellular DNA distributions. DNA index (DI) and hyperdiploid fraction (HDF) were calculated for each histogram using an automated technique. The results showed significant inter- and intra-laboratory differences. Results were evaluated by a two-way analysis of variance to estimate components of the overall variation attributable to individual sources. Error variation was found to be the major component of random variation. Specimen means were also compared for each laboratory. No significant differences were noted in mean DI for similar specimens; however, agreement in HDF between similar specimens was lacking in most laboratories. Prediction intervals were computed to estimate the range of values expected for a single specimen based on the analysis of the previous six. Prediction intervals for DI were quite good while those for HDF were troublesome due to wide variation. The results of these studies indicate that intra- and inter-laboratory variability are high enough that results for a single sample may not be sufficiently precise to allow comparison to results obtained in other laboratories.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1991

Multidrug resistance activity in human lymphocytes.

The multidrug resistance gene (mdr1) is a member of the recently described ATP binding cassette (ABC) superfamily of transporters. Family members include: (1) the cystic fibrosis transmembrane conductance regulator gene; (2) the hlyB gene of bacteria, and (3) the histocompatibility antigen modifier (HAM) gene. The level of expression of mdr1 correlates with multidrug resistance (MDR), the ability of cells to efflux otherwise toxic doses of several chemotherapeutic agents. MDR activity is also associated with the efflux of cationic lipophilic compounds such as the fluorescent dye rhodamine 123. Recently it was reported that normal lymphocytes efflux rhodamine 123, suggesting that these cells possess MDR-like activity due to the expression of mdr1. In this study, using two-color flow cytometric analysis, we observed that the ability to efflux rhodamine 123 was heterogeneous among human lymphocyte subsets in the order of CD8 greater than CD4 greater than CD2O. Rhodamine 123 efflux and accumulation in lymphocytes was sensitive to the known MDR reversing agents, verapamil and Solutol HS 15. Collectively, these data suggest that an MDR-like transport system is present in normal lymphocytes and may be important for trafficking of molecules involved in lymphocyte function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

P-glycoproteins in pathology: the multidrug resistance gene family in humans.

Many cancers do not respond to chemotherapy on primary exposure to drugs, thus manifesting intrinsic drug resistance. Other cancers that do initially respond subsequently become resistant to the same drugs and simultaneously to other drugs to which the patient has had no previous exposure. This is a form of acquired drug resistance. There is a pressing need to better understand the mechanisms of drug resistance and to use this information to develop strategies for the chemosensitization of drug-resistant tumors. A goal of the pathology laboratory is to offer chemosensitivity tests that identify intrinsic or acquired resistance of tumors to specific drugs or classes of drugs to enable the clinician to tailor therapy to the biology of cancers in individual patients. Multidrug resistance is one type of drug resistance. It can be present in either an intrinsic or acquired form. The human gene that confers human multidrug resistance, the MDR1 gene, has been cloned and classified as a member of the MDR gene family. Its encoded protein, called Mdr1, is an energy-driven membrane efflux transporter that maintains intracellular concentrations of certain chemotherapeutic drugs at nontoxic levels. Useful model systems for studying multidrug resistance have been developed in several research laboratories. Applying selection pressure by exposing cultured cancer cells to escalating doses of natural product anti-cancer drugs allows cross-resistant cell lines to be produced which share patterns of drug resistance with human cancers. A common feature of these drug-resistant lines is the expression of Mdr1. Using techniques of genetic engineering, molecular probes have been developed that can be used to measure MDR1 mRNA and MDR1 gene amplification. Mdr can be measured by immunochemistry methods. Currently, such measurements are being used to stratify patients in clinical trials designed to determine if chemosensitization by inhibition of the pump function of Mdr is a clinically useful therapeutic strategy. If successful, Mdr/MDR1 mRNA laboratory testing might significantly increase the clinical laboratory's role in cancer patient management.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

ABO blood type predicts the cytolocalization of anti-P-glycoprotein monoclonal antibody reactivity in human colon and ureter.

Classic multidrug resistance is mediated by a P-glycoprotein. Using monoclonal antibody C219 (MAb C219) in an immunohistochemical study, we found high levels of putative Golgi P-glycoprotein in normal columnar and transitional epithelium in subpopulations of patients with specific blood types. For example, Golgi staining was present in blood type A patients in 46% of normal colon samples (N = 21) and 88% of normal ureter samples (N = 17). In comparison, Golgi staining was present in blood group O patients in only 6% of normal colon samples (N = 34) and in 0% of normal ureter samples (N = 19). The association of MAb C219 Golgi staining with blood type A and lack of Golgi staining with blood type O was statistically significant in normal colon (P = .001) and normal ureter (P less than .0001). Inappropriate hyperexpression of P-glycoprotein was frequently found in colon carcinomas. Additional evidence that Golgi MAb C219 reactivity represents P-glycoprotein is presented. This includes (1) immunostaining of Golgi with two anti-P-glycoprotein MAbs, C219 and JSB-1, and (2) experiments in which Mab C219 Golgi reactivity was blocked by preincubation of MAb C219 with a specific P-glycoprotein epitope-containing peptide. The high degree of association of Golgi P-glycoprotein with blood type A may suggest a role for P-glycoprotein in processing or trafficking of specific blood group antigens.

ABO Blood-Group System↗
PubMed1990

Osteoporosis in women with eating disorders: comparison of physical parameters, exercise, and menstrual status with SPA and DPA evaluation.

Osteoporosis has been reported in anorexia nervosa (AN), but not in other eating disorders. Thirty-three patients, 8 AN, 17 bulimia nervosa (BN), and 8 eating disorder not otherwise specified (EDNOS), were evaluated by bone densitometry (radius, spine, femur) to determine the prevalence and distribution of osteoporosis and the role of physical parameters, exercise and estrogen. All three diagnostic subgroups had evidence of decreased bone density, worst in the EDNOS subgroup and least in the BN subgroup. The most affected site was the femur, least the spine; the radius was intermediate. Age, body surface area, age of onset, and length of illness weakly correlated with the femur and spine density in the BN and EDNOS subgroups. Exercise was related to bone density in the AN subgroup in the femur, moderate exercise having a protective effect and strenuous exercise being detrimental. No significant correlation of bone density measurements with estradiol levels and/or history of amenorrhea was identified. Eating disorder patients are at risk for osteoporosis, which has multiple contributing factors including physical parameters and exercise. Estrogen deficiency by itself may not be a major causative factor.

Absorptiometry, Photon↗