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M R Melamed

Publications and source records attributed to M R Melamed.

At least 73 records · Page 4Linked to original sources
PubMed1991

Blood group and blood-group-related antigens in normal pancreas and pancreas cancer: enhanced expression of precursor type 1, Tn and sialyl-Tn in pancreas cancer.

Expression of blood-group antigens A, B, Le(a), sialyl-Le(a) (sLe(a)), Le(b), Le(x), Le(y), precursor type I, Tn and sialyl-Tn (sTn) was examined in non-neoplastic pancreas (n = 37) and pancreas cancer (n = 21) using mouse monoclonal antibodies (MAbs). Immunohistochemical assays were performed on sections of paraffin-embedded tissues using the avidin-biotin complex method. In normal pancreas, antibodies detecting Le(a), sLe(a) and Tn reacted with ductal epithelium, and antibodies detecting A and B reacted with acini and ducts, independently of secretor status. Le(x) was weakly expressed in ducts and acini, and sTn could not be detected in normal pancreas. Expression of Le(b), Le(y) and precursor type I was regulated by secretor status: Le(b) and Le(y) were expressed in ducts of secretor and Le(a-b-) individuals, but not in ducts of non-secretors; precursor type I was weakly expressed in acini and ducts of non-secretors and Le(a-b-) individuals, and was absent in acini and ducts of secretors. The following alterations in the expression of blood-group antigens were observed in pancreas cancer: (1) enhanced expression of Le(x), Tn and sTn; (2) enhanced expression of precursor type I independently of secretor status; (3) loss of regulation of Le(b) by the secretor gene; (4) decreased expression of Le(y). The weak expression of precursor type I. Tn and sTn in non-neoplastic pancreas, and their stronger expression in pancreas cancer, suggests that up-regulation of their expression is associated with malignant transformation of pancreatic duct cells.

ABO Blood-Group System↗
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

Simultaneous detection of fluorescent in situ hybridization and in vivo incorporated BrdU in a human bladder tumour.

We have used fluorescent in situ hybridization and simultaneous in vivo bromodeoxyuridine labelling of a solid bladder cancer to examine tumour cell subsets for possible proliferative growth differences. In this dual-labelled preparation, most tumour cell nuclei exhibited monosomy 9, consistent with reported karyotypes of bladder cancer. Incorporated bromodeoxyuridine was visualized with a fluoresceinated antibody in 5-6 per cent of the tumour cells, concordant with S-phase estimates by cell cycle analysis of the flow cytometric DNA histogram. A majority of the bromodeoxyuridine-positive cells also carried the monosomy 9 chromosome abnormality. This is the first report to demonstrate the feasibility of combined in situ hybridization and detection of bromodeoxyuridine incorporated in vivo in human tumour cells in order to provide information on the growth rate of specific subsets of tumour cells identified by chromosomal constitution.

Bromodeoxyuridine↗
PubMed1991

Retention of the mitochondrial probe rhodamine 123 in normal lymphocytes and leukemic cells in relation to the cell cycle.

The cationic fluorochrome rhodamine 123 (R123) is specifically taken up by mitochondria of live cells where it is retained due to the mitochondrial transmembrane potential. After pulse exposure of human normal quiescent or proliferating lymphocytes, human lymphocytic leukemic MOLT cells, and mice leukemic L1210 cells to 10 micrograms/ml of R123, the dye release was studied using flow cytometry. Two distinct phases of R123 release, each following first-order kinetics, were apparent; the half-time of retention for the rapidly and slowly released fractions of R123 was 0.8-1.1 and 2.8-4.2 h, respectively. Simultaneous supravital cell staining with R123 and Hoechst 33342 made it possible to correlate retention of R123 with cell position in the cell cycle. No significant differences were observed in the rate of R123 release from cells in G1 vs S or vs G2 + M phases of the cycle. The data rule out a possibility that the release of R123 is due to periodic depolarization of the mitochondria in the cell as may be postulated by cell cycle models that assume a transient passage of cells through resting phase following division. The observed similar rates of R123 release regardless of cell type or cell cycle phase suggest that the factors affecting the exchange are similar in normal lymphocytes vs leukemic cells and unrelated to cell proliferation rate or phase of the cell cycle. Two distinct rates of R123 release indicate the presence of two kinds of binding sites differing in affinity to the dye.

Cell Cycle↗
PubMed1991

Immunohistochemical analysis of neural cell adhesion molecules. Differential expression in small round cell tumors of childhood and adolescence.

The neural cell adhesion molecule (NCAM) was discovered in a search for cell surface antigens of chicken neurons that contribute to cell adhesion and pattern formation during development. Homologous adhesion molecules have been identified in several species, including humans. In this immunohistochemical study, the authors examine the role of human NCAM in tumor diagnosis. The authors used a monoclonal antibody (MAb), 5.1H11, to examine NCAM immunoreactivity in frozen sections of more than 450 tumors, including more than 80 small round cell tumors (SRCT) of childhood and adolescence (neuroblastomas, Ewing's sarcomas [ES], peripheral neuroepitheliomas [PN], primitive neuroectodermal tumors [PNET], esthesioneuroblastomas, malignant ectomesenchymoma, medulloblastomas, small cell osteosarcomas, mesenchymal chondrosarcomas, embryonal rhabdomyosarcomas, and lymphomas). The authors show that 1) neuroblastomas and primary brain tumors are NCAM+; 2) ES, most PN/PNETs, and melanomas are NCAM-; 3) embryonal rhabdomyosarcomas and various other sarcomas are NCAM+; 4) neuroendocrine tumors are NCAM+; 5) subsets of carcinomas of kidney, ovary, lung and other organs are NCAM+; and 6) lymphoid tumors are NCAM-. Tests with normal fetal and adult tissues indicate that these findings reflect only in part the NCAM phenotypes of corresponding normal tissues. Notably the NCAM- phenotype of ES and PN/PNET is not explained by current histogenetic models for these tumors, which suggest a primitive neuroectodermal origin. Finally the authors show that NCAM expression among SRCT has an inverse relationship with the expression of p30/32MIC2, a cell surface antigen of ES and PN/PNET detected with MAb HBA71. These results suggest that immunohistochemical assays for NCAM and p30/32MIC2 expression may aid in the further characterization of SRCT of childhood and adolescence.

Antibodies, Monoclonal↗
PubMed1991

Effect of swainsonine on interleukin-2 alpha chain receptor expression and proliferation of human lymphocytes.

Swainsonine, an inhibitor of mannosidase II, involved in N-linked glycoprotein processing, modifies expression of cell surface receptors. This alkaloid has strong anti-metastatic and immunomodulatory activity; it enhances stimulation of lymphocytes triggered by concanavalin A (ConA) but suppresses stimulatory effects of phytohaemagglutinin (PHA). We presently observe that swainsonine decreases expression of the interleukin-2 (IL-2) receptor (IL-2R) on PHA-stimulated human peripheral blood lymphocytes, measured by binding of a monoclonal antibody that recognizes the 55-kD glycoprotein subunit (alpha) of this receptor. Proliferation of the PHA-stimulated lymphocytes is suppressed by swainsonine, which manifests in the decreased proportion of both cells entering G1 (from G0) and those progressing through S. G2 and M. This suppression can be overcome by addition of IL-2 into cultures. In contrast, swainsonine has no effect on IL-2R expression and stimulation (cell cycle progression) of lymphocytes triggered by the monoclonal antibody OKT3. The data suggest a possibility that the observed swainsonine effects on lymphocytes stimulated by PHA are mediated via surface receptors other than IL-2R. These receptors may appear prior to IL-2R and be also involved in cell stimulation by PHA but not by other mitogens.

Alkaloids↗
PubMed1990

DNA in situ sensitivity to denaturation in bladder cancer and its correlation with tumor stage.

DNA content and sensitivity of DNA in situ to denaturation by acid were analyzed by flow cytometry of cell nuclei freshly isolated from the bladder tumors of 32 patients and were compared with normal urothelium of 8 subjects. DNA sensitivity to denaturation was assessed in RNase treated cells by acridine orange metachromasia following partial denaturation with hydrochloric acid; the extent of denatured DNA is given as an index (alpha t), representing the ratio of single stranded to total DNA per nucleus. Of the low stage tumors (papillomas, Ta, Tis, T1) 11 of 18 (61%) were aneuploid. Of the high stage tumors (T2 and T3a) 11 of 14 (79%) were aneuploid. DNA in nuclei of normal transitional epithelium was very sensitive to denaturation, as was papilloma, characterized by nuclear alpha t indices of 0.73 +/- 0.01 (SD) and 0.73 +/- 0.04, respectively. Nuclear DNA of noninvasive carcinomas (Ta, Tis) was significantly more resistant to denaturation (alpha t = 0.69), and DNA of invasive carcinomas was most resistant, ranging from alpha t = 0.61 (T1 tumors) to alpha t = 0.59 (T2 tumors) to alpha t = 0.57 (T3 tumors). High stage tumors as a group (T2, T3) had significantly different (lower) alpha t values than low stage tumors (Ta, Tis, T1). In model cell culture systems it is known that a decrease in alpha t index, i.e., greater resistance to denaturability, occurs as cells transit from resting phase into the cell cycle. Whether the alpha t index can be used to estimate resting vesus cycling cells of human tumors is still speculative; changes in DNA denaturability also are known to occur with changes in chromatin structure during cell differentiation and in transformation. However, the empirical relationship between alpha t index and tumor stage, of itself, may prove clinically useful in identifying more advanced and perhaps more aggressive tumors.

Biopsy↗
PubMed1990

Lung cancer and exposure to tobacco smoke in the household.

BACKGROUND: The relation between passive smoking and lung cancer is of great public health importance. Some previous studies have suggested that exposure to environmental tobacco smoke in the household can cause lung cancer, but others have found no effect. Smoking by the spouse has been the most commonly used measure of this exposure. METHODS: In order to determine whether lung cancer is associated with exposure to tobacco smoke within the household, we conducted a population-based case--control study of 191 patients with histologically confirmed primary lung cancer who had never smoked and an equal number of persons without lung cancer who had never smoked. Lifetime residential histories including information on exposure to environmental tobacco smoke were compiled and analyzed. Exposure was measured in terms of "smoker-years," determined by multiplying the number of years in each residence by the number of smokers in the household. RESULTS: Household exposure to 25 or more smoker-years during childhood and adolescence doubled the risk of lung cancer (odds ratio, 2.07; 95 percent confidence interval, 1.16 to 3.68). Approximately 15 percent of the control subjects who had never smoked reported this level of exposure. Household exposure of less than 25 smoker-years during childhood and adolescence did not increase the risk of lung cancer. Exposure to a spouse's smoking, which constituted less than one third of total household exposure on average, was not associated with an increase in risk. CONCLUSIONS: The possibility of recall bias and other methodologic problems may influence the results of case-control studies of environmental tobacco smoke. Nonetheless, our findings regarding exposure during early life suggest that approximately 17 percent of lung cancers among nonsmokers can be attributed to high levels of exposure to cigarette smoke during childhood and adolescence.

Adolescent↗
PubMed1990

Targeted cytogenetic analysis of gastric tumors by in situ hybridization with a set of chromosome-specific DNA probes.

Fluorescent in situ hybridization (FISH) with biotinated chromosome-specific repetitive DNA probes was used for the cytogenetic study of ten gastric adenocarcinomas. All tumors (eight male, two female patients) were histologically moderately or poorly differentiated and nine of ten had metastasized to regional lymph nodes. The authors applied a set of satellite DNA probes, specific for chromosomes 1, 7, 17, X, and Y in order to detect numerical chromosome aberrations in freshly isolated tumor cell nuclei. Normal diploid human lymphocyte nuclei and, in a number of cases, normal gastric mucosa served as controls. Parallel with the hybridization experiments DNA flow cytometric study of acridine orange (AO)-stained tumor cells was carried out. By means of FISH the authors found seven cases to be aneuploid, the other three cases appeared diploid. This was confirmed by DNA flow cytometric analysis with AO. Furthermore, loss of the Y chromosome in a high percentage of cells was seen by FISH in six of eight tumors from male patients. In the other two male samples a possible loss was observed in a small proportion of cells (15%). In three patients from whom the authors had normal gastric mucosa the Y loss was restricted to the tumor cells. These data indicate that in situ hybridization with chromosome-specific repetitive DNA probes can serve as a cytogenetic tool for the analysis of interphase nuclei of solid human tumors, at least with respect to the detection of numerical chromosome abnormalities.

Adenocarcinoma↗
PubMed1990

Enhanced bladder cancer detection with the Lewis X antigen as a marker of neoplastic transformation.

Recent evidence indicates that the Lewis X determinant is a tumor-associated antigen in the urothelium. Immunohistochemical analyses on frozen and deparaffinized, formalin-fixed tissue sections have demonstrated that the Lewis X antigen is not detected in normal adult urothelium except for occasional umbrella cells. However, papillomas and transitional cell carcinomas express this blood group-related antigen in more than 90% of the cases regardless of the grade or stage of the tumor, or the blood type or secretor status of the individual. To determine the presence of Lewis X antigen on exfoliated bladder epithelial cells we used an anti-Lewis X monoclonal antibody (P-12) and the avidin-biotin-peroxidase technique on 129 bladder barbotage specimens. Of 40 controls 34 were negative for Lewis X antigen, for a specificity of 85%. The 89 bladder tumor patients consisted of 14 with papilloma, 13 with flat carcinoma in situ, 49 with transitional cell carcinoma, and 13 with a positive cytology and negative biopsy results. Of these 89 patients 76 were considered positive for Lewis X antigen, for an over-all sensitivity 85.4%. The sensitivity for cytology alone was 61.2%. However, the combination of a positive cytology and/or positive Lewis X antigen result yielded a sensitivity of 93.2%. The data suggest that immunocytological detection of the Lewis X antigen on exfoliated bladder cells enhances the detection of urothelial tumor cells, particularly from low grade and low stage neoplasms.

Antibodies, Monoclonal↗
PubMed1990

Characterization of the morphonuclear features and DNA ploidy of typical and atypical carcinoids and small cell carcinomas of the lung.

The authors analyzed several cytomorphonuclear parameters related to chromatin distribution and DNA ploidy in typical and atypical carcinoids and in small cell lung cancers. Nuclear measurements and analysis were performed with a SAMBA 200 (TITN, Grenoble, France) cell image processor with software allowing the discrimination of parameters computed on cytospin preparations of Feulgen-stained nuclei extracted from deparaffinized tumor tissues. The authors' results indicate a significant increase in DNA content--assessed by integrated optical density (IOD)--from typical carcinoids to small cell lung carcinomas, with atypical carcinoids showing an intermediate value. Parameters related to hyperchromatism (short and long run length and variance of optical density) also characterize the atypical carcinoids as being intermediate between typical carcinoids and small cell lung cancers. The systematic measurement of these cytomorphonuclear parameters seems to define an objective, reproducible "scale" of differentiation that helps to define the atypical carcinoid and may be of value in establishing cytologic criteria for differential diagnosis.

Carcinoid Tumor↗
PubMed1990

Follicular neoplasms of the thyroid in men older than 50 years of age. A DNA flow cytometric study.

The clinical behavior of follicular neoplasms of the thyroid in elderly men can be difficult to predict on histologic grounds alone. To assess the usefulness of DNA flow cytometry in predicting the metastatic potential of these tumors, the authors studied 44 primary and metastatic follicular neoplasms of the thyroid by DNA flow cytometry of paraffin-embedded tissue. The neoplasms were obtained from 44 men ranging in age from 50 to 79 years (mean, 60). There were 29 follicular adenomas, 11 primary follicular carcinomas (neoplasms with capsular and/or vascular invasion), and 4 metastatic follicular carcinomas. Follow-up information was available on 40 of the 44 patients. The mean follow-up was 114 months. Twenty-five of the 29 follicular adenomas had a diploid DNA content, 2 (7%) were tetraploid, and the DNA histograms on 2 were not interpretable. All patients with follicular adenomas had no evidence of disease (NED) at last follow-up. Eight of the 11 primary follicular carcinomas were diploid. Six of these patients had NED, one died with carcinoma at 82 months, and no follow-up was available on one. Three (27%) of the primary follicular carcinomas were aneuploid or tetraploid. Two of these patients had NED, and the third died with carcinoma 84 months after diagnosis. Two of the four metastatic follicular carcinomas were diploid and two (50%) were aneuploid or tetraploid. One of the two patients with diploid metastatic follicular carcinomas died with carcinoma, as did one of the two patients with aneuploid metastatic follicular carcinomas. These results suggest the following: (1) follicular carcinomas are more likely to be aneuploid or tetraploid than are follicular adenomas; (2) follicular neoplasms without capsular or vascular invasion may include a small number of aneuploid or tetraploid tumors; and (3) DNA ploidy does not add to the prognostic value of histologic studies alone.

Adenocarcinoma↗
PubMed1990

Flow cytometry detection and evaluation of bladder tumors.

The diagnosis and classification of bladder cancer are based primarily on histologic and cytologic light microscopy. The significant cytologic alternations are abnormal (increased) DNA content and structural changes in chromatin. Measurements of DNA content carried out by flow cytometry on suspensions of tumor cells and bladder irrigation specimens correlate well with clinical and biopsy findings. Badalament et al (Badalament RA, Kimmel M, Gay H, et al. Cancer 1987;59:2078-2085) reported that a single bladder wash flow cytometry correctly detected 83% of bladder cancers. The technique is most sensitive in detecting early, in situ, and superficially invasive carcinoma. In 100 urologic patients with non-neoplastic disease of the bladder, Klein et al (Klein FA, Herr HW, Sogani PC, et al. J Urol. 1982;127:946-948) reported only two false-positive examinations. Flow cytometry appears to be at least as valuable as conventional urinary cytology, without the need of an experienced cytopathologist. However, as specimens must be collected by bladder irrigation via catheter or cytoscope, the technique is most suitable not for population screening, but in monitoring high-risk populations: industrial workers or others exposed to carcinogens, persons with a history of urothelial tumors, and adult patients referred for urologic examinations because of hematuria, unexplained, recurrent cystitis, or other urologic symptoms. DNA flow cytometry also has been valuable in monitoring the conservative treatment of bladder cancer and of predictive value in the intravesical bacille Calmette-Guérin treatment of superficial carcinomas of the bladder. Dual parameter measurements of DNA content and antigen expression are now under evaluation, as are measurements of chromatin structure alteration, metabolism, and proliferative rate. These promise to discriminate subsets of bladder cancer that may be predictive of clinical behavior.

Antibodies, Monoclonal↗
PubMed1990

Voided urine flow cytometry in screening high-risk patients for the presence of bladder cancer.

Fifty-nine patients with a history of bladder cancer were evaluated with three serially voided urines for flow cytometry and cytology within the 24 hours preceding cystoscopy, bladder wash, and biopsy. Evaluation of the 32 patients with biopsy proven cancer revealed that for one, two, and three voided urine specimens, the sensitivity of flow cytometry in detecting bladder cancer was 29%, 35%, and 41%, respectively, whereas the sensitivity of voided urine cytology was 44%, 53%, and 57%, respectively. Bladder wash flow cytometry had a sensitivity of 76%. Interpretation of the voided urine flow cytometry was based on a control group of 80 volunteers with negative voided urine cytology. The control group demonstrated that a minimum of 1500 analyzable cells was necessary for a reliable histogram. Considering all 59 patients, voided urine flow cytometry, bladder wash flow cytometry, and voided urine cytology were acceptable for analysis in 53%, 93%, and 100% of the specimens, respectively. Voided urine specimens appear less suitable than bladder irrigation specimens for evaluation by flow cytometry. Voided urine flow cytometry is less sensitive in detecting bladder cancer than voided urinary cytology or bladder wash flow cytometry and is not effective for use as a bladder cancer screening test.

Cystoscopy↗
PubMed1990

Caffeine increases sensitivity of DNA to denaturation in chromatin of L1210 cells.

Exposure of exponentially growing L1210 cells to 5 mM and higher concentrations of caffeine perturbs their progression through the cell cycle and results in increased sensitivity of DNA in situ to denaturation. The latter is detected by the increased metachromatic stainability of DNA with acridine orange (AO) and sensitivity to S1 nuclease, measured by flow cytometry. Decreased DNA stability is generally characteristic of chromatin condensation and in untreated cells is observed in mitosis or quiescence (G0). The caffeine-induced decrease in DNA stability affects the interphase cells regardless of their position in the cycle and the changes are stochastic, concentration- and time-dependent. Populations of cells responding to caffeine are very heterogenous with respect to the degree of destabilization of DNA; sensitivity of DNA to denaturation of the maximally affected cells is similar to that of untreated cells in mitosis. The present method allows one to quantitatively express effects of caffeine on nuclear chromatin in individual cells of large cell populations and may be employed in studies correlating chromatin changes induced by this agent with its effects in modulation of cell sensitivity to radiation or antitumour drugs.

Acridine Orange↗
PubMed1990

Comparison of anatomical location of squamous cell carcinoma within the oral cavity and oropharynx with the incidence of in vitro hyperdiploidy.

The anatomical location of the squamous cell carcinoma (SCCA) within the oral cavity and oropharynx influenced the association of SCCA with the biomarker in vitro hyperdiploidy in human dermal fibroblast cultures (IVH). There was a strong association of IVH with the occurrence of SCCA in the anterior 2/3 of the tongue, floor of the mouth and lower alveolar ridge of the oral cavity and in the base of the tongue and pharyngeal wall of the oropharynx. There was a lower association of SCCA with IVH in the tonsillar region of the oropharynx. IVH showed no association with SCCA located in other anatomical parts of the oral region. The patient group whose diagnosis of SCCA in the anterior 2/3 of the tongue occurred prior to the age of 50 years were invariably IVH-, whereas those diagnosed after the age of 50 years were IVH+, providing evidence for heterogeneity. There was no such correlation of biomarker subgrouping with age of diagnosis demonstrated for SCCA at any other anatomical location within the oral cavity or oropharynx.

Adult↗
PubMed1990

Cytogenetic analysis of human solid tumors by in situ hybridization with a set of 12 chromosome-specific DNA probes.

We have applied fluorescent in situ hybridization (FISH) to assess the presence of numerical chromosome aberrations in fresh specimens of human solid tumors of varying histology. For this purpose, a set of 12 biotinylated chromosome-specific, repetitive alpha-satellite DNA probes (for chromosomes 1, 6, 7, 9, 10, 11, 15, 16, 17, 18, X and Y) were hybridized directly to isolated interphase nuclei. Utilizing this approach, we found numerical chromosome changes in all tumors. FISH ploidy profiles were in accordance with flow cytometric DNA histograms of these tumor cells.

Chromosome Aberrations↗