Search PubMed⌕ Search

Biomedical subjects

M R Melamed

Publications and source records attributed to M R Melamed.

At least 163 records · Page 9Linked to original sources
PubMed1985

Cell surface antigen of human neuroblastomas is related to nuclear antigen of normal cells.

The localization of MC25, an antigen first detected on the surface of human neuroblastoma cells, was determined in cultured cells and tissues. Neuroblastoma cell lines (15/17) express the antigen on the surface and in the cytoplasm (scMC25+), whereas 156/160 cell lines derived from other normal and malignant human cell types are scMC25-. However, MC25 is found in the nucleus of scMC25- cells (nMC25+), presenting a discrete granular pattern. In scMC25+/nMC25- neuroblastoma lines, apparent antigen shifting from the cell surface/cytoplasm to the nucleus accompanies variant formation, which represents a transition in the neuronal differentiation program of these cells. Results of immunohistochemical studies with human tissues parallel the findings with cultured cells. Almost all cell types are scMC25-/nMC25+; basal cells of the epidermis are the only cells constitutively expressing cMC25; and a population of neurons are the only scMC25-/nMC25- cells. Alternative localization of MC25 to different cellular compartments and antigen shifting are reminiscent of the behavior of certain developmentally regulated antigens in Drosophila and Xenopus.

Antibodies, Monoclonal↗
PubMed1985

Mouse monoclonal IgG3 antibody detecting GD3 ganglioside: a phase I trial in patients with malignant melanoma.

R24 is an IgG3 mouse monoclonal antibody that identifies GD3, a prominent ganglioside on the surface of melanoma cells and other cells of neuroectodermal origin. Twelve patients with metastatic melanoma were treated with R24 at three dose levels, 8, 80, or 240 mg/m2, over a period of 2 weeks. Peak antibody levels in the serum were dose related and ranged from less than 0.1 to 62 micrograms/ml. Inflammatory reactions (urticaria, pruritus, erythema, subcutaneous ecchymoses) were observed around tumor sites in patients treated at doses greater than or equal to 80 mg/m2. Tumor biopsies during and after treatment showed lymphocyte and mast cell infiltration, mast cell degranulation, and complement deposition. Side effects were mild and were readily controlled by antihistamines. Major tumor regression has been observed in three patients.

Adult↗
PubMed1985

Specificity analysis of mouse monoclonal antibodies defining cell surface antigens of human renal cancer.

Six mouse monoclonal antibodies (mAbs) defining separate systems of cell surface antigens of cultured human renal cancer were tested for reactivity with normal fetal and adult tissues and with neoplastic tissues. Five of the mAbs identified glycoproteins of Mr 160,000 (designated S4), Mr Mr 140,000 (F23), Mr 120,000 (S23 and S27), and Mr 115,000 (S22). The glycoprotein component of Mr 120,000 has been shown recently to be the adenosine deaminase binding protein (ADA-BP) and mAbS23 and mAbS27 define two distinct epitopes on ADA-BP. S22 was not detected on any normal fetal or adult tissues but was found on a subset of renal cancers. S4, F23, S23, and S27 defined distinct domains of the nephron: glomerulus (S4), proximal tubules (S4, F23, S23, and S27), and portions of Henle's loop (S23 and S27). mAbS4 also reacted with the interstitial matrix in the renal medulla and of other tissues, and mAbF23 reacted with fetal and adult fibroblasts. The S23 epitope of ADA-BP was expressed by placental trophoblasts and epithelial cells of breast, prostate, lung, and colon, whereas the S27 epitope was detected on a more limited range of cell types (trophoblasts and prostate epithelium). A panel of 20 renal cell carcinomas was typed for expression of these antigens; 7 phenotypes could be distinguished, with the S4+/F23+/S23+/S27+/S22+ or - phenotype (15 cases) being most common. The other antigenic system, V1, identified a heat-stable antigen that was widely expressed on cultured cell types but showed a restricted pattern of reactivity in tissues. V1 expression was limited to the adrenal cortex, Leydig cells, and the theca of ovarian follicles, and to adrenal cortical carcinomas.

Animals↗
PubMed1985

Immunopathologic analysis of a panel of mouse monoclonal antibodies reacting with human ovarian carcinomas and other human tumors.

The reactivity of a panel of five mouse monoclonal antibodies (mAb) produced to human ovarian and endometrial cancer cell lines was analyzed on frozen sections of normal adult and fetal tissues and on tumor sections using immunofluorescence and immunoperoxidase procedures. mAb MH99 was reactive with almost all types of epithelial cells and stained all epithelial tumors examined. mAb MH94 reacted mainly with secretory epithelia and was unreactive with the epithelial cell layer of normal ovaries. In contrast, approximately 50% of epithelial ovarian tumors and the lining cells of inclusion cysts were positive. mAb MF61 was positive only on the endometrium and noncellular follicular secretions or colloid of the thyroid among normal tissues examined. A subset of ovarian tumors was positive with this antibody. mAb MF116 gave no reactivity with normal tissues within the sensitivity of the assay. MF116 was expressed on a proportion (44%) of ovarian carcinomas of various histological types. These antibodies provide an initial panel for the immunohistological analysis of ovarian cancer.

Animals↗
PubMed1985

Rhodamine 123 alters the mitochondrial ultrastructure of cultured L1210 cells.

Exposure of exponentially growing L1210 cells in vitro to 5-10 micrograms/ml of rhodamine 123 (R123) for 16-48 hr inhibits cell proliferation and induces cell arrest in the G1A phase of the cell cycle. The cells remain viable during the arrest and resume growth after removal of R123; extended exposure to R123 is cytotoxic. Exposure to R123 results in morphological alterations in mitochondria of all cells observed; specifically, mitochondria of R123-treated cells are characterized by a distention of the intracristal spaces and a significant increase in the number of matrix granules. Gross morphological changes of mitochondria include formation of extended organelles and the appearance of doughnut-shaped structures.

Animals↗
PubMed1985

Characterization and cell cycle kinetics of hepatocyte populations isolated from adult liver tissue by a nonenzymatic procedure.

Suspensions of liver cells enriched in lobular parenchymal hepatocytes were isolated from adult mouse hepatic tissue by nonenzymatic dispersion in chelating buffer and sedimentation of the released cells at unit g. Single cell suspensions so obtained were suitable for flow cytometric measurements of hepatic ploidy class distributions. The more quickly sedimenting cell population consisted of 88% albumin/transferrin-positive epithelial hepatocytes, the nuclei of which were bimodally distributed with respect to RNA content. This dual G1 population was observed in 2C DNA content liver nuclei prepared by several methods and appears to be a general cytochemical characteristic of adult liver parenchymal cells.

Animals↗
PubMed1985

Detection of 5-bromodeoxyuridine (BrdUrd) incorporation by monoclonal antibodies: role of the DNA denaturation step.

Immunochemical detection of cells that incorporate 5-bromodeoxyuridine (BrdUrd) requires prior denaturation of DNA in situ to make BrdUrd binding sites accessible to the antibodies. A technique is described in which the DNA denaturation step is facilitated by a) prior dissociation of histones from DNA and b) the use of low ionic strength buffer in which the cells are suspended during heating. Dissociation of histones is achieved by cell treatment with 0.08N HCl at 0 degree C, which a) increases accessibility of DNA to propidium iodide (and following the denaturation to the antibodies); b) lowers stability of DNA to thermal denaturation; c) decreases differences between various cell types due to variability in chromatin structure; and d) ensures more complete DNA denaturation. Cell heating (80-95 degrees C) at low ionic strength (1 mM Na+) eliminates the need for formamide and results in extensive and rapid DNA denaturation. The method was applied in Friend leukemia, L1210 and HL-60 cell lines, and to bone marrow, experimental animal tumor and primary human tumor cells.

Animals↗
PubMed1985

Cytokinetics of a human neuroblastoma cell line following treatment with dianhydrogalactitol.

Studies were carried out on the effect of dianhydrogalactitol on a human neuroblastoma cell line in culture. The drug was cytotoxic at concentrations of 5 micrograms/ml and 10 micrograms/ml for 1 hour, but not at 1 microgram/ml. Flow cytometry of DNA showed that cell kill was preceded by a transient accumulation of cells in early S at 10 hours, and in late S at 36 hours. Smaller increases in the percent of cells in S phase were seen after treatment with 1 microgram/ml, without cell kill. It may be concluded that dianhydrogalactitol causes an S-phase block, followed by death of cells in late S at concentrations above 5 micrograms/ml.

Cell Cycle↗
PubMed1985

Effect of intravesical Bacillus Calmette-Guérin on detection of a urothelial differentiation antigen in exfoliated cells of carcinoma in situ of the human urinary bladder.

Flow cytometry was used to detect and quantify expression of a urothelial differentiation antigen (Om5) and nuclear DNA in exfoliated epithelial cells of the urinary bladder from 15 patients with nonpapillary carcinoma in situ during and after intravesical therapy with Bacillus Calmette-Guérin (BCG). Before BCG treatment exfoliated cells reacting with the mouse monoclonal antibody Om5 were found in 13 cases. Following treatment Om5 positive cells were still present in 9 cases but 4 patients who had had Om5 positive cells prior to BCG therapy no longer had detectable antigen-positive cells after therapy. Thus intravesical BCG therapy can alter detection of a urothelial differentiation antigen in exfoliated bladder epithelial cells. It is not certain whether this antigen or other differentiation antigens measured by flow cytometry will advance our present techniques for assessing effects of therapy on carcinoma in situ and other bladder tumors. However, five of nine patients showing persistence of Om5 positive cells after therapy were found to have recurrent tumor by biopsy and two others had positive cytology (median follow-up, 13 months). None of the four without detectable antigen-positive cells after therapy had clinical evidence of tumor by cystoscopy, biopsy, or cytology (median follow-up, 12 months). It now appears feasible and desirable to initiate clinical investigations of this and other differentiation antigens in combination with DNA by flow cytometry of bladder irrigation specimens.

Antigens, Neoplasm↗
PubMed1985

Surface antigens of melanomas and melanocytes defined by mouse monoclonal antibodies: specificity analysis and comparison of antigen expression in cultured cells and tissues.

Mouse monoclonal antibodies (mAb) detecting 13 distinct systems of surface antigens on cultured melanocytes and melanomas were tested for reactivity with panels of (a) normal and malignant cultured cells; (b) normal adult and fetal tissues; and (c) specimens of metastatic melanoma and other tumor types. The objectives of this study were to compare antigen expression in cultured versus noncultured cells, to develop a panel of mAbs that identify subsets of melanomas, and to provide requisite information about antibody specificity in preparation for the use of antibodies in the diagnosis, imaging, and therapy of melanoma. Five of the melanoma surface antigens have been well characterized biochemically [GD3, chondroitin sulfate proteoglycan, HLA Class II antigens, glycoprotein of molecular weight 130,000 (gp130), and glycoprotein Mr 95,000/protein Mr 97,000 (gp95/p97)]. Three antigens have been related to melanocyte differentiation (HLA Class II, M111/M231, and M144), and six provide additional markers for subsets of cultured melanomas. mAb R24 reacts with the disialoganglioside GD3, a predominant ganglioside on cultured melanoma cells and other cells of neuroectodermal origin. A high proportion of melanoma, astrocytoma, and sarcoma tissue specimens were GD3+. In normal tissues, reactivity of mAb R24 was restricted to melanocytes, neuronal and glial cells in the central nervous system, parotid gland, adrenal medullary cells, and rare cells in the connective tissue. mAb B5 detects a chondroitin sulfate proteoglycan that is expressed by most melanoma and astrocytoma cell lines and by cultured melanocytes. Most of the melanoma and astrocytoma specimens were B5+, whereas other tumor types tested were B5-. mAb 13-17, which detects a monomorphic determinant of HLA Class II antigens, reacted with melanomas, and with a variety of other cancers, but not with normal skin melanocytes. There is considerable variability in the expression of GD3 and HLA Class II antigens in individual melanoma specimens; cotyping for these two antigens showed no evidence for coordinate expression. mAb L101 detects gp130 and mAb L235 detects gp95, antigens that are strongly expressed on a broad range of cultured cell types. In contrast to their wide distribution on cultured cells, gp130 expression in tissues was generally restricted to a subset of melanomas and some normal cells, and gp95 was detected on only a small number of melanomas. mAb M111/mAb M231 and mAb M144 define intermediate and late stage differentiation markers of cultured melanocytes and melanomas.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Distribution of the ganglioside GD3 in the human nervous system detected by R24 mouse monoclonal antibody.

Immunohistochemical staining with mouse monoclonal antibody R24 recognizing the ganglioside GD3 was used to study the distribution of GD3 in the human brain. Positive staining was primarily found in the surrounding neuropil of many neuronal groups in the brainstem and spinal cord, cerebellum, retina and dentate gyrus of hippocampus. In addition, staining was found in ependymal cells and glial processes around blood vessels and in the subependymal region.

Animals↗
PubMed1984

Male reproductive capacity may recover following drug treatment with the L-10 protocol for acute lymphocytic leukemia.

Six men with acute lymphocytic leukemia (ALL) were studied prospectively to assess the effect of treatment with the L-10 protocol on reproductive capacity. Before therapy three men had fathered children (two, two children; one, three children); the others were sexually mature although no fertility studies had been done prior to or during their treatment. Each patient had a minimum of 3 1/2 years of continuous chemotherapy as part of this study. Semen analysis was done 10 to 52 months (median, 31.5 months) after completion of therapy. One patient had lower than normal sperm concentration but near normal total sperm count and normal motility; the others had a normal sperm concentration and motility. Sperm nuclei were isolated from each sample and analyzed by flow cytometry for resistance to DNA denaturation in situ; all samples had relatively high resistance to denaturation, consistent with a normal, fertile reproductive status. After completion of therapy, one patient fathered a normal child, and a second patient fathered one child with multiple congenital malformations followed by a second child who was normal.

Adult↗
PubMed1984

Accessibility of DNA in situ to various fluorochromes: relationship to chromatin changes during erythroid differentiation of Friend leukemia cells.

Friend leukemia cells from exponentially growing or differentiated (DMSO-induced) cultures were permeabilized and their DNA was stained with 4'6-diamidino-2-phenylindole (DAPI), Hoechst 33342, acridine orange, ethidium bromide, propidium iodide, quinacrine, 7-amino-actinomycin D, mithramycin, or chromomycin A3. Accessibility of DNA to each of the above fluorochromes was compared in differentiated and nondifferentiated cells before and after nuclear proteins, mostly histones, were extracted with 0.1N HCl. A decrease in the accessibility of DNA to several dyes, especially pronounced in the case of some intercalators, was observed in differentiated cells. After extraction of nuclear proteins with HCl there was an increase in DNA accessibility, of varying degree depending on the fluorochrome and the difference between differentiated and nondifferentiated cells was abolished for most of the intercalating dyes. The increase was the lowest for DAPI (45%), the highest for 7-amino-actinomycin D (13-fold), and in general was higher for the intercalating dyes that unwind DNA than for dyes binding externally to the double helix. The results are discussed in terms of the mode of interactions between DNA and the fluorochromes and factors associated with chromatin structure that may affect accessibility of DNA in situ in exponentially growing and differentiated cells.

Animals↗
PubMed1984

Flow cytometric evaluation of sperm from patients with testicular carcinoma.

Semen samples from 14 patients with testicular cancer were analyzed by new flow cytometry techniques and by conventional semen analysis. Samples were obtained post-unilateral orchiectomy and prior to further treatment. With only 1 exception, light microscopic analysis of sperm count and morphology indicated a decrease of normal sperm production and incomplete or abnormal differentiation. Flow cytometry of semen aliquots showed, with the same exception as above, increased acridine orange staining of the sperm nuclear chromatin, attributed to abnormal chromatin composition and condensation. In addition, the chromatin structure of isolated sperm nuclei was abnormally sensitive to thermal stress. These changes were present up to 15 months post orchiectomy and suggest abnormal spermiogenesis in the contralateral testis of patients with testicular tumors. Of the 14 patients studied only 1 fell well within the normal range for all parameters measured; 2 other patients were in the low normal range for all parameters and 1 patient fell below normal for light microscope derived measurements but was normal by flow cytometry. The other 10 patients had abnormal measurements for all parameters. The assessment of spermiogenesis by flow cytometry studies of sperm chromatin appears to be a sensitive and valuable new parameter of fertility that cannot be determined by conventional semen analysis.

Acridine Orange↗
PubMed1984

Cell surface antigens of human bladder cancer defined by mouse monoclonal antibodies.

Mouse monoclonal antibodies were obtained by immunization with cultured human bladder cancer or lysates of bladder papilloma. They identify 11 distinct antigenic systems as defined by serological analysis of cultured cells and studies of antigen distribution in normal and neoplastic tissues. The most restricted of these antigens, Om5, defines a subset of bladder tumors. Om5 is not detected in normal bladder urothelium or in any other normal or malignant tissue. T101 and JP165 are also subset markers for bladder cancer that are not detected in normal tissues. T16, T43, T87, and J143 (antigens represented on many cultured cells) are found in specific areas of the normal urinary tract and in a distinctive range of other normal and malignant cell types--e.g., T16 expression in pluristratified epithelium of skin, exocervix, and esophagus. T138 antigen is also a common feature of cultured cell lines, but its expression in sections of normal tissues is restricted to endothelial cells. In contrast, T110 is poorly represented on cultured cells but can be detected in culture supernatants. Localization of T110 in normal tissues showed that it is a component of the extracellular matrix. All determinants detected by this series of antibodies are heat labile and not related to A, B, H, I, Lewis blood group antigens. Six of the antibodies immunoprecipitated glycoproteins from radiolabeled cell lysates: AbT16 (Mrs 48,000 and 42,000), AbT87 (Mr 60,000), AbT43 (Mr 85,000), AbJ143 (Mr 140,000, 120,000, 60,000), AbT43 (Mr 85,000), AbJ143 (Mr 140,000, 120,000, and 30,000), and AbT110 (Mr 240,000).

Antibodies, Monoclonal↗
PubMed1984

Non-small-cell lung cancer: results of the New York screening program.

Radiographs of 168 patients with non-small-cell lung cancer were reviewed. Following a negative initial examination, 102 tumors were detected during routine annual screening, while 66 were diagnosed during the interval between screenings. The cancers detected on routine yearly examination were smaller; the rate of resectability was higher, a larger number were Stage I, and survival was better. Within the routinely screened group, 65% had evidence of cancer on reviewing earlier radiographs; these patients tended to have earlier stages of cancer and a better survival rate.

Adenocarcinoma↗