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Biomedical subjects

M R Melamed

Publications and source records attributed to M R Melamed.

At least 145 records · Page 8Linked to original sources
PubMed1986

Effect of section thickness on quality of flow cytometric DNA content determinations in paraffin-embedded tissues.

DNA content determinations were carried out by flow cytometry on nuclear suspensions prepared from the same paraffin-embedded tissue block for each of eight surgically resected human carcinomas at section thicknesses of 5,10,20,30,40,50, and 100 millimicrons. Flow cytometric DNA determinations were also obtained on fresh tissue specimens in four of the eight carcinomas. As section thickness decreased below 50 millimicrons, there was a progressive increase in the histogram baseline noise at low DNA values and a decrease in the relative peak height of aneuploid DNA. The former was attributed to an increase of nuclear fragments in thinner sections, and the latter to the greater probability of transection of the larger aneuploid cells within a specimen. Both artifacts were minimized at section thickness of 50 millimicrons or greater.

Breast Neoplasms↗
PubMed1986

Flow cytometry of colorectal carcinoma with three-year follow-up.

Flow cytometry DNA measurements were carried out on colorectal carcinomas from a series of 33 patients who have since been followed for three to four years. The tumors could be subclassified by this technique into 15 that had near-diploid DNA and 18 that were aneuploid. Prior reports had suggested that the near-diploid tumors carry a better prognosis than aneuploid tumors, but in this study the distribution by Dukes' stage and survival were the same in both groups.

Adult↗
PubMed1986

Long-term effect of intravesical bacillus Calmette-Guerin on flat carcinoma in situ of the bladder.

Intravesical bacillus Calmette-Guerin is effective therapy for multifocal carcinoma in situ of the bladder. The duration of this favorable response and its effect on disease progression are the subject of this report. Between March 1978 and July 1981, 47 patients with diffuse, often symptomatic, carcinoma in situ were treated with intravesical bacillus Calmette-Guerin and followed every 3 to 4 months with cystoendoscopy, biopsy and urine cytology for 3 to 6 years. All patients had had prior or concurrent superficial papillary tumors controlled initially by transurethral resection and fulguration 2 to 3 weeks before bacillus Calmette-Guerin treatment. Of the 47 patients 23 were entered into a randomized study, and received intravesical and percutaneous bacillus Calmette-Guerin. Another 24 patients with carcinoma in situ were treated with intravesical bacillus Calmette-Guerin alone. Bacillus Calmette-Guerin (Pasteur strain) was given intravesically (120 mg. in 50 ml. saline) weekly for 6 weeks. Of the 47 patients 32 (68 per cent) are free of disease (negative urine cytology, cystoendoscopy and biopsy): 15 (65 per cent) after combined bacillus Calmette-Guerin for a median duration of 51 months (range 37 to 75 months) and 17 (71 per cent) after intravesical bacillus Calmette-Guerin alone for a median of 45 months (range 36 to 53 months). Of the 23 patients in the randomized study 4 (17 per cent) have required cystectomy for local progression of disease compared to 17 of 26 controls (65 per cent) who were randomized to transurethral resection and fulguration alone. Cystectomy was performed 3 to 27 months after bacillus Calmette-Guerin treatment and in 3 patients tumor was localized to the prostate gland (no tumor found within the bladder). These data indicate that intravesical bacillus Calmette-Guerin is capable of producing long-term remissions of carcinoma in situ in high risk patients and may prevent or delay progression of disease necessitating cystectomy.

Biological Products↗
PubMed1986

High energy shock waves suppress tumor growth in vitro and in vivo.

Exposure of the Dunning R3327AT-3 rat prostatic carcinoma and SK-Mel-28 human melanoma, in vitro, to high energy shock waves resulted in a reduction in cell viability as determined by trypan blue exclusion and a decrease in the number of colonies formed in a clonogenic assay. Flow cytometric determination of DNA content in R3327AT-3 cells treated in vitro indicated a selective diminution of cells in the G2 and M phases of the cell cycle. When R3327AT-3 cells exposed to high energy shock waves were subsequently injected into rats, or tumor bearing animals were treated by high energy shock waves targeted at the tumor, a delay in tumor growth was observed. These observations indicate that high energy shock waves are cytotoxic to tumor cells in vitro and in vivo. Additional research into the possible use of high energy shock waves in the non-invasive destruction of animal and human tumors is warranted.

Animals↗
PubMed1986

Expression of cytokeratins in normal and neoplastic colonic epithelial cells. Implications for cellular differentiation and carcinogenesis.

Cells of the normal colonic mucosa express several types of cytokeratins, the characteristic intermediate filament proteins of epithelial cells. An immunohistochemical study was designed to examine the expression of two distinct groups of cytokeratins, recognized by monoclonal antibodies AE1 and AE3, in the colonic mucosa and to compare the findings with those obtained with a large number of polypoid lesions (adenomatous and hyperplastic) and carcinomas of the colon. AE1 and AE3 immunostaining was found in the surface epithelium and upper portions of the crypts of Lieberkühn (functional zone) of normal colonic mucosa, whereas the lower portions of the crypts (proliferative compartment) were unreactive with both AE1 and AE3. Polypoid lesions of the colonic mucosa can be placed into two categories based on their patterns of cytokeratin expression. Solitary tubular adenomas and hyperplastic polyps are composed of AE1 and AE3 nonexpressing cells with only few, patchy areas of AE1 and AE3 expressing cells present within glands and in the surface epithelium. In contrast, villous adenomas show strong AE1 and AE3 reactivity throughout the glands. Furthermore, tubular and villous adenomas, and even histologically normal mucosa in patients with familial polyposis, show AE1/AE3 expression throughout the glands and surface epithelium. Colonic carcinomas show a predominance of AE1/AE3 expressing cells. Thus, cytokeratins recognized by monoclonal antibodies AE1 and AE3 represent molecular markers of cellular maturation in the normal colonic mucosa, that are expressed in colonic carcinomas and, in addition, serve as markers that distinguish colonic mucosa and adenomas with a high risk for development of cancers from those with a lower risk.

Adenocarcinoma↗
PubMed1986

Detection of central nervous system relapse in acute leukemia by multiparameter flow cytometry of DNA, RNA, and CALLA.

DNA/RNA flow cytometry studies were performed on the spinal fluid samples of thirty patients with acute leukemia or lymphoma at the time of clinical central nervous system relapse, and compared with similar studies of 56 patients (98 specimens) who had leukemia in remission with no evidence of CNS disease. Twelve of the 30 patients with CNS involvement had cells with abnormal DNA content in the spinal fluid (40%); the remaining eighteen had cells with diploid DNA content. In the group of 18 with diploid DNA, 10 had other abnormalities detected by flow cytometry. These included eight patients with acute leukemia who had cells with high RNA content, and two patients with non-Hodgkin's lymphoma who had markedly increased proliferation. Of the 22 patients studied by conventional cytology nine were negative for malignant cells, and in eight of these patients flow cytometry studies of DNA/RNA demonstrated abnormalities. Common ALL antigen was demonstrated by flow cytometry in three out of five cases studied. Thus, abnormal DNA content, increased RNA content, increased proliferation and/or expression of the cell surface antigen CALLA identified CNS relapse by flow cytometry in 22 of 30 patients with acute leukemia or lymphoma. The technique appears to be at least as sensitive as conventional cytology and identifies CNS relapse in some patients with negative cytology.

Antigens, Neoplasm↗
PubMed1986

Cytostatic and cytotoxic properties of pyronin Y: relation to mitochondrial localization of the dye and its interaction with RNA.

Pyronin Y (PY) is an intercalating cationic dye that shows specificity towards RNA. In viable cells this dye also accumulates in mitochondria. The cytostatic and cytotoxic effects of PY on L1210 and Chinese hamster ovary cells were studied in relation to its intracellular localization and compared with the affinity of PY to bind to double-stranded DNA and RNA and its propensity to condense single-stranded DNA and RNA. Antitumor properties of PY were tested on L1210 leukemia and Sarcoma 180 ascites in mice. At a concentration of 1.7 to 3.3 microM, PY was localized almost exclusively in mitochondria of cultured cells, similar to another mitochondrial probe, rhodamine 123. At that concentration PY was not toxic but suppressed cell growth, arresting cells in G1. At a concentration of 6.7 to 33.0 microM, PY was also localized in nucleoli and uniformly in cytoplasm, bound to the RNase-sensitive material therein. At that high concentration PY induced cell arrest in G2 and S and was cytotoxic. The dye exhibited a propensity to bind and condense (precipitate) single-stranded nucleic acids, and condensation could be measured by the appearance of light-scattering products. Among a variety of natural and synthetic nucleic acids the most sensitive were the RNA polymer, polyriboadenylate, and the copolymer, polyriboadenylate and polyriboguanylate, which underwent condensation at a PY concentration of 6.6 to 10.0 microM. Natural and synthetic DNA polymers were resistant to condensation. The data suggest that the cytostatic (G2 and S arrest) and cytotoxic (inability to exclude trypan blue, loss of clonogenicity) effects of PY seen at 6.7 to 33.0 microM concentration may be a consequence of the dye binding to RNA. PY may intercalate to double-stranded RNA and/or cause the specific condensation of single-stranded RNA; the polyadenylated sections of mRNA appear to be the most sensitive cellular targets to undergo condensation. PY showed antitumor properties extending survival of L1210 leukemic mice by 50% and slowing growth of Sarcoma 180 ascites tumor. The possibility that certain antitumor drugs, generally believed to act via intercalation to DNA, may exert chemotherapeutic effects via their interactions with RNA is discussed.

Animals↗
PubMed1986

Immunoanatomic distribution of blood group antigens in the human urinary tract. Influence of secretor status.

Seven mouse monoclonal antibodies and the lectin from Ulex europaeus, detecting blood group specificities of the ABH and Lewis systems, have been used to define the immunoanatomic distribution of these antigenic structures within the human nephron and urothelium. The reagents employed recognize the following blood group related antigens: A (all variants), B, H, Lewisa (Lea), Lewisb (Leb), X (Lewisx), Y (Lewisy) and type 1 precursor chain. We have analyzed the presence of these antigens in histologically normal kidney and urothelium from 22 adults and 3 fetuses by the immunoperoxidase method. In addition, we simultaneously examined blood group and secretor status in 15 of the 22 adult individuals studied. Immunohistochemical analyses demonstrated that these antigenic systems are differentially expressed in cell types and domains of the human urinary tract. Major differences were observed in secretor as compared to nonsecretor individuals, mainly in the more pronounced expression of precursor, H, Leb, and Y antigens in secretors. In the kidney, all antigens, except X, showed enhanced expression in secretor individuals on epithelial cells of the collecting ducts and urothelium; X antigen was mainly present in the proximal tubules and portions of Henle's loop. The urothelium was particularly rich in blood group antigens and in some cases showed differential expression of Lea/X and Leb/Y on the various cell layers. Secretors could be divided into two groups based on the intensity and pattern of staining; it is suggested that this may be determined by homo- or heterozygosity at the Se locus. Nonsecretor individuals lacked expression of Leb and Y determinants, as well as H antigen, in the urothelium (three of four cases). Comparison of normal fetal and adult tissues suggest that the expression of some of these antigens is related to maturation stages of the human nephron. These studies confirm the importance of blood group antigens as normal differentiation antigens. These reagents have a wide range of applications including typing of blood group and secretory status in body fluids and tissues, studies of histogenesis and organogenesis, and analyses of neoplastic and non-neoplastic diseases.

ABO Blood-Group System↗
PubMed1986

A standardized assay to identify colon cancer genotypes by in vitro tetraploidy in human dermal fibroblasts.

Increased tetraploidy in dermal fibroblast cultures (IVT), which is a putative biomarker for genetic predisposition to colon cancer, was assayed by two different methods: by per cent of tetraploid metaphases in chromosome preparations from non-confluent monolayer petri dish cultures in logarithmic growth (MA); by flow cytometry (FCM) distribution of DNA content of propidium iodide stained cells from plastic flask cultures in stationary growth phase. The assayed cultures were derived from split thickness skin biopsies from two clinical groups: 11 normal individuals without a family history of colon cancer and 17 clinically affected individuals with autosomal dominant polyposis coli cancer syndrome (6 with colonic adenomatosis, i.e. familial polyposis coli (FPC) and 11 also having extracolonic lesions, i.e. the Gardner syndrome, (GS). Concordance was observed between the two assays. There was a linear relationship between the per cent of tetraploid metaphases assayed in the chromosome preparations and the per cent of cells with a DNA index (DI) of precisely 2, or of all cells with a DI greater than 1 as determined by FCM. In comparisons between the clinical groups, there was significant differences in the FCM DNA index (p values less than 0.001) of IVT- (normals and IVT- FPC) and IVT+ individuals (IVT+ GS and those FPC with IVT). The per cent of cells with a DI of 2 and greater than 1 could be used to distinguish all IVT- individuals (normals and IVT- FPC) from IVT+ FPC individuals. However, only by per cent of cells with a DI greater than 1 could all the individual GS affecteds be distinguished from IVT- individuals. Thus, the per cent of cells with a DI greater than 1 is considered to be the parameter of choice to be used in assaying IVT by flow cytometry.

Adenomatous Polyposis Coli↗
PubMed1986

Expression of epidermal growth factor receptor in human cultured cells and tissues: relationship to cell lineage and stage of differentiation.

Mouse monoclonal antibodies have been used to study the distribution of the epidermal growth factor receptor in human cultured cells and tissues. As expected, most epithelial cells expressed epidermal growth factor receptor (EGFr), whereas cells of hematopoietic origin were EGFr-. However, EGFr was found to be differentially expressed on cultured cells of neuroectodermal origin. Normal melanocytes and a proportion of melanomas are EGFr-, whereas a distinct subset of other melanomas, astrocytomas, and neuroblastomas is EGFr+. Expression of the EGFr in melanomas was closely related to the expression of phenotypic traits of differentiation. Less differentiated melanomas have an epithelioid morphology and are nonpigmented, Ia+, and EGFr+; in contrast, more differentiated melanomas have a dendritic morphology and are pigmented, Ia-, and EGFr-. In the melanoma cell panel used, expression of EGFr did not correlate with rate of proliferation. Expression of EGFr in tissues also showed a lack of correlation with the proliferative state of cells. Our findings indicate that expression of EGFr is related to cell lineage and specific stages of cellular differentiation, rather than only to cell proliferation. The data suggest that receptor content may be elevated in a large number of tumor cell lines.

Antibodies, Monoclonal↗
PubMed1986

Transthoracic aspiration cytology of pulmonary lesions.

In a seven-year period (1974 to 1981), 1,390 patients had transthoracic aspiration biopsy for radiologically suspected pulmonary neoplasms. Of the 1,209 proven malignant neoplasms, 1,059 (88%) were cytologically diagnosed as malignant. There were only two (0.2%) false-positive diagnoses both due to florid bronchoalveolar hyperplasia associated with granulomatous disease. Cytologic and histologic correlations for primary lung cancers were 92% for adenocarcinoma, 87% for oat cell (small cell) carcinoma, and 83% for epidermoid carcinoma. Characteristic cytomorphology of pulmonary carcinomas, some metastatic neoplasms, and inflammatory lesions are described.

Adenocarcinoma↗
PubMed1986

Expression of murine gamma fetal antigen in adult hematopoietic tissue and during induced differentiation of Friend erythroleukemia cells.

Quantitative analysis of extracts of various normal adult CD-1 mouse tissues indicated that the serologically defined murine gamma fetal antigen (gamma-FA) was expressed at high levels in hematopoietic tissue in general and in bone marrow (BM) in particular. Metabolic labeling of isolated BM cells indicated that the BM was a site of gamma-FA synthesis in the adult animal. The size(s) of the antigen immunoprecipitated from labeled BM cells (35 and 27 kilodaltons) with anti-gamma-FA serum correlated well with molecular weight estimates of fibrosarcoma-fetal mouse-associated gamma-FA, as determined by molecular sieve chromatography. For ascertainment of the relationship between hematopoietic cell differentiation and gamma-FA content, a multiparameter flow cytometric approach was used to evaluate gamma-FA levels in Friend erythroleukemia (FL) cells as a function of growth state (blast or dimethyl sulfoxide-differentiated) and cell-cycle compartment. Differentiated G1-arrested FL cells (G1D) possessed significantly lower gamma-FA-associated immunofluorescence as compared to control cells in the G0-G1 substate. Remaining S- and G2 + M-phase cells in differentiated populations demonstrated an even greater reduction in gamma-FA content relative to control cells in the corresponding cell-cycle phases. The available data support the tentative classification of gamma-FA as a murine differentiation antigen.

Actins↗
PubMed1986

Cell surface antigens of human bladder tumors: definition of tumor subsets by monoclonal antibodies and correlation with growth characteristics.

Normal human urothelium and tumors of urothelial origin were analyzed with a panel of seven mouse monoclonal antibodies that identify surface antigens of cultured bladder cancer cell lines. Three categories of antigens were defined on the basis of differential expression on normal urothelium versus bladder tumors. Om5 (a category 1 antigen) is a highly restricted, differentiation antigen detected in the normal urothelium of 50-60% individuals. No other normal cell type in Om5- or Om5+ individuals expresses Om5. The incidence of Om5 expression in superficial bladder tumors is significantly higher (88%) than in normal urothelium, whereas its expression in invasive or metastatic tumors is far lower (20%), suggesting Om5 gain/loss in bladder tumors. Paired biopsies of normal urothelium and bladder tumors from the same individuals have shown Om5 induction in the superficial bladder tumors of Om5- individuals and Om5 loss in invasive bladder cancers of Om5+ individuals. Category 2 antigens (T43, T138, T23) are not expressed by normal urothelium or most superficial bladder tumors but are detected on a high proportion of invasive or metastatic bladder tumors, indicating that category 2 antigens are associated with late stages of tumor progression. Category 3 antigens (T16, T87, J143) provide lineage markers for normal or neoplastic cells of urothelial origin, being found on normal urothelium and virtually all bladder tumors. Thus, differential expression of category 1 and 2 antigens divide bladder tumors into distinct subsets, and these subsets correlate with pathological and clinical features of the disease.

Antibodies, Monoclonal↗
PubMed1985

Denaturation and condensation of DNA in situ induced by acridine orange in relation to chromatin changes during growth and differentiation of Friend erythroleukemia cells.

DNA in situ is progressively denatured when the cells or nuclei are treated with increasing concentration of acridine orange (AO). This transition can be monitored by flow cytometry as a decrease in green fluorescence. The complexes of denatured DNA and AO undergo immediate condensation and aggregation; this step is manifested by appearance of red luminescence and formation of precipitates that can be detected by electron microscopy. The precipitates form preferentially in heterochromatin as well as in ribosomes and polysomes. Their formation and further aggregation affects cellular light scatter properties in both the forward and right-angle direction. The AO-induced DNA denaturation and condensation was studied in nuclei of Friend erythroleukemia cells from exponentially growing, differentiated or quiescent cells. The DNA in nuclei of quiescent cells, from plateau-phase cultures, was the most sensitive to denaturation; it denatured (measured by changes in luminescence) at an AO concentration between 50 and 80 microM with the midpoint of the transition (Cd) at 70 microM. DNA in nuclei of differentiated cells (dimethyl-sulfoxide-induced erythroid differentiation) was more resistant (Cd = 77-83 microM), whereas DNA in exponentially growing cells was the most resistant (Cd = 86 microM). Extraction of proteins with 0.1 M HCl at 0 degree C abolished the differences between the cells and shifted the transition to a lower AO concentration (Cd = 46 microM). For comparison, the midpoint transitions representing condensation of free, nucleic acids measured as light scatter changes occurred at 13, 22, 31 and 53 microM of AO, for rRNA, tRNA, and denatured and native-calf thymus DNA, respectively. Denaturation and condensation of DNA, which can be induced by AO either in isolated nuclei or viable permeabilized or fixed cells provides a new approach to discriminate cell subpopulations with different chromatin structure by flow cytometry. The molecular mechanisms of this phenomenon are discussed.

Acridine Orange↗
PubMed1985

Experience with intravesical bacillus Calmette-Guèrin therapy of superficial bladder tumors.

Between March, 1978, and July, 1981, 86 patients with polychronotopic superficial papillary bladder tumors and concurrent carcinoma in situ were randomized to receive either transurethral resection alone (43) or TUR plus BCG (43). The results indicate that BCG is not only active in preventing recurrences of new tumors but also effective for the diffuse, flat carcinoma in situ.

Adult↗
PubMed1985

Intratubular malignant germ cells (carcinoma in situ) accompanying invasive testicular germ cell tumors.

We examined 111 radical orchiectomy specimens from patients with germ cell tumors of the testis treated between 1971 and 1981 for the presence of intratubular malignant germ cells (so-called carcinoma in situ) in adjacent testicular tissue. Of the specimens 12 were unevaluable because the entire specimen was tumor, while 36 of 44 cases of pure seminoma (82 per cent) and 41 of 55 mixed or nonseminomatous tumors (75 per cent) had intratubular malignant germ cells. Of the 22 cases without intratubular malignant germ cells 10 had severe atypia that suggested an earlier or borderline stage of development. These data support the contention that germ cell tumors originate as intratubular neoplasms or so-called carcinoma in situ in the seminiferous tubules.

Adolescent↗
PubMed1985

Monitoring intravesical bacillus Calmette-Guerin treatment of bladder carcinoma with flow cytometry.

Flow cytometry of bladder irrigation specimens was studied in 22 patients with low stage bladder carcinoma who were treated by transurethral resection of visible tumor followed in 3 to 5 weeks by a course of intravesical bacillus Calmette-Guerin. The most informative examinations were just before the first bacillus Calmette-Guerin treatment, 6 weeks after completing a 6-week course of treatment (3 months) and at 9 months. Of the patients 10 had recurrent tumors after therapy; recurrence was anticipated correctly by flow cytometry at the 12-week followup examination in 6 of the 10 patients and suspected in another. Of 12 patients who remained clinically free of disease for a minimum of 15 months after bacillus Calmette-Guerin therapy flow cytometry identified correctly 7 at 12 weeks, while 1 had a partial response and the remaining 4 reverted to a negative status at 9 months. Of interest, only 4 of the 22 patients were free of disease by flow cytometry at the start of bacillus Calmette-Guerin treatment despite attempted ablation of the tumor by transurethral resection, suggesting that intravesical administration of bacillus Calmette-Guerin destroys existing carcinoma in situ in some cases.

BCG Vaccine↗