Biomedical subjects

M R Melamed

Publications and source records attributed to M R Melamed.

At least 109 records · Page 6Linked to original sources

PubMed1988

Blood group-related antigens in human urothelium: enhanced expression of precursor, LeX, and LeY determinants in urothelial carcinoma.

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 expression and/or modulation of these antigenic structures in human normal urothelium and tumors of the urinary bladder. The reagents employed recognize the following blood group related antigens: A, B, H, Lewisa (Lea), Lewisb (Leb), Lewisx (Lex), Lewisy (Ley), and type 1 precursor chain. Immunohistochemical studies have demonstrated that these antigenic systems are differentially expressed in the urothelium of secretor and nonsecretor individuals. The normal urothelium of secretors is particularly rich in ABH blood group antigens as well as Leb and Ley specificities. Nonsecretors, however, either lack or show decreased and patchy expression of H, Leb, and Ley antigens. In general, areas affected by carcinoma in situ showed deletion of ABH, as did invasive carcinomas, as demonstrated by other investigators. This was not a universal observation, however, as variable expression of ABH antigens occurred in a few invasive tumors. Lex antigen was not expressed in normal urothelium except for occasional umbrella cells, but was demonstrated in the majority of invasive tumors, regardless of blood type and secretor status of the individuals studied. Ley determinant, which was poorly expressed in the normal urothelium of nonsecretor individuals, was found in all tumors analyzed. An accumulation of non-fucosylated precursor structure was also a feature of invasive carcinoma, particularly in secretor individuals. A panel of anti-blood group antibodies, encompassing A, B, Lex, Ley and type 1 precursor chain specificities for use in patients of known secretor status, may provide useful early markers of malignant change in the urothelium.

Adult↗

PubMed1988

Natural history of adenocarcinoma-large cell carcinoma of the lung: conclusions from screening programs in New York and Baltimore.

A mathematical model of the progression kinetics of lung cancer was described and used to shed light on the natural history of adenocarcinoma and large cell carcinoma of lung from data collected in screening studies of male smokers by the Memorial Sloan-Kettering Cancer Center and The Johns Hopkins Medical Institutions. In both programs, estimates of the mean duration of early-stage adenocarcinoma or large cell carcinoma of lung ranged upward from 4 years, and estimates of the probability of detecting it in early-stage disease ranged downward from .16. The probabilities of curing early-stage disease through surgical treatment were found to be at most .52 and .13 in the New York and Baltimore studies, respectively. These estimates led to the conclusion that expected reduction in mortality from adenocarcinoma and large cell carcinoma of lung as due to annual x-ray screening from age 45 to 80 years is not greater than 18% in New York and 5% in Baltimore.

Adenocarcinoma↗

PubMed1988

Anticarcinoma activity of rhodamine 123 against a murine renal adenocarcinoma.

The mitochondria of carcinoma cells retain the permeant cationic compound rhodamine 123 longer than the mitochondria of normal epithelial cells. The possibility of exploiting this difference in the chemotherapy of a murine renal adenocarcinoma was investigated. Rhodamine 123 exhibited anticarcinoma activity in mice and this activity was potentiated by 2-deoxyglucose and methylglyoxal bis(guanylhydrazone), a chemotherapeutic agent that is toxic to mitochondria. Prolonged retention of rhodamine 123 by renal tumor cells compared with normal renal epithelial cells was demonstrated by flow cytometry, perhaps explaining its antitumor activity. A combination of both mitochondrial toxins, rhodamine 123 and methylglyoxal bis(guanylhydrazone) produced the longest survival and had the greatest antitumor effect.

Adenocarcinoma↗

PubMed1988

Definition of an extracellular matrix protein in rostral portions of the human central nervous system.

We have identified and characterized an extracellular matrix (ECM) glycoprotein of cultured astrocytomas, NEC1, that is expressed in normal human brain parenchyma. Detailed immunohistochemical analysis reveals a region-specific NEC1 pattern along the rostrocaudal axis of the central nervous system (CNS), with strong expression throughout the white matter of telencephalon and diencephalon, scant expression in some areas of mesencephalon, and no expression in pons, cerebellum, medulla, spinal cord, and peripheral nervous system. NEC1 is not co-distributed with any known neural cell type, suggesting that expression of specific ECM proteins in the CNS is segmentally controlled.

Antibodies, Monoclonal↗

PubMed1988

Interinstitutional variability in DNA flow cytometric analysis of tumors. The National Cancer Institute's Flow Cytometry Network Experience.

Flow cytometric DNA analysis of human urinary bladder specimens may be clinically useful for prognosis in transitional cell (urothelial) carcinoma and for detecting recurrence after treatment. However, many important methodological differences exist among institutions which have described this technique, and it has not previously been shown that data from different institutions are comparable. The National Cancer Institute has created a Flow Cytometry Network to address the need for technology assessment of flow cytometry. This report describes the independent flow cytometric analysis and interpretation of "unknown" paraffin-embedded bladder tumor specimens by the five Network institutions. Although important differences in method existed among the institutions, substantial agreement was achieved in actual data generated and their interpretation. This suggests that a consensus regarding acceptable laboratory performance of this technique could be reached, which should facilitate its more widespread clinical implementation.

Carcinoma, Transitional Cell↗

PubMed1988

Comparison of automated and manual techniques for analysis of DNA frequency distributions in bladder washings.

Quantitative methods for interpretation of flow cytometry DNA histograms are required for the widespread clinical use of this technology. The usefulness of a histogram analysis technique in this setting requires that it be operator independent, easy to implement in a clinical laboratory, and provide high sensitivity to the desired information. Additionally, the technique must be tolerant of the relatively low signal-to-noise ratios often found in DNA distributions obtained from clinical samples. Among the factors that have been used to assess the malignant potential of tumors are the presence of an aneuploid population, the proportion of hyperdiploid cells, the width of the G1 peak, the DNA index, and the fraction of cells in S. A computer-based method has been developed for extraction of the above-mentioned features from DNA histograms. The program detects peaks in the histogram and uses straight-line fits to the cumulative frequency distribution to define cell population bounds. A test set of 44 histograms compiled from bladder irrigation specimens obtained from patients with a present or past history of transitional cell carcinoma (TCC) was analyzed by five collaborating laboratories forming a Network sponsored by the National Cancer Institute (NCI). This test set was used to evaluate the performance of the computer-based method by comparing results with those of four expert observers. In this preliminary analysis, perfect agreement was found in the detection of aneuploid cell populations by all observers and the computer-based method. Correlation of percent hyperdiploid cell fraction was also excellent.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗

PubMed1988

Flow cytometry and cytology as response indicators to M-VAC (methotrexate, vinblastine, doxorubicin and cisplatin).

We evaluated 23 patients treated with neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin for muscle invasive bladder carcinoma with serial bladder wash flow cytometry and serial urinary cytology. The sensitivities of bladder wash flow cytometry and cytology in detecting bladder cancer were 74 and 47 per cent, respectively, based on subsequent diagnosis from biopsy and cystectomy specimens. Exclusion of those cases without surface carcinoma increased the sensitivities of bladder wash flow cytometry and cytology to 93 and 60 per cent, respectively. Persistently positive bladder wash flow cytometry and cytology correctly predicted residual disease in 88 and 100 per cent, respectively. However, negative bladder wash flow cytometry and cytology after chemotherapy were not reliable indicators of disease-free status.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1988

Detection of carcinoma in the post-cystectomy urethral remnant by flow cytometric analysis.

Following radical cystoprostatectomy for bladder cancer patients must be monitored for carcinoma of the urethral remnant. Cytological examination of urethral washings has proved to be a useful alternative to urethroscopy and urethrography. Urethral irrigation specimens also can be evaluated objectively by flow cytometry. In each of 4 patients in whom carcinoma developed in the urethral remnant analysis of urethral irrigation by flow cytometry was positive and comparable to results of urethral irrigation cytology. Flow cytometry is an objective and apparently reliable diagnostic test for malignancy in the urethral remnant.

Aged↗

PubMed1988

Cell-surface glycoproteins of human sarcomas: differential expression in normal and malignant tissues and cultured cells.

Normal differentiation and malignant transformation of human cells are characterized by specific changes in surface antigen phenotype. In the present study, we have defined six cell-surface antigens of human sarcomas and normal mesenchymal cells, by using mixed hemadsorption assays and immunochemical methods for the analysis of cultured cells and immunohistochemical staining for the analysis of normal tissues and greater than 200 tumor specimens. Differential patterns of F19 (Mr, 120,000/95,000 glycoprotein), F24 (Mr, 95,000 glycoprotein), G171 (Mr, 75,000 glycoprotein), G253 (Mr, 90,000 glycoprotein), S5 (Mr, 120,000 glycoprotein), and Thy-1 (Mr, 25,000 glycoprotein) antigen expression were found to characterize (i) subsets of cultured sarcoma cell lines, (ii) cultured fibroblasts derived from various organs, (iii) normal resting and activated mesenchymal tissues, and (iv) sarcoma and nonmesenchymal tumor tissues. These results provide a basic surface antigenic map for cultured mesenchymal cells and mesenchymal tissues and permit the classification of human sarcomas according to their antigenic phenotypes.

Antibodies, Monoclonal↗

PubMed1988

Immunohistochemical analysis of nerve growth factor receptor expression in normal and malignant human tissues.

Nerve growth factor (NGF) is a polypeptide important for normal development of the nervous system and promotion of survival and differentiation of sensory and sympathetic neurons in culture. The cellular effects of NGF are mediated by a specific cell surface molecule, nerve growth factor receptor (NGF-R). In the present study we have used a monoclonal antibody against human NGF-R to examine, by the avidin-biotin-immunoperoxidase method, the receptor distribution in a wide range of normal tissues and in more than 200 malignant tumors. Our results show that (a) human NGF-R is expressed in the peripheral nervous system but not in any of the central nervous system areas tested; (b) NGF-R expression is not restricted to neural tissues but is also found in a number of normal epithelial, mesenchymal, and lymphoid tissues; (c) NGF-R expression changes during normal development; and (d) NGF-R expression in malignant tumors generally parallels its normal tissue distribution. Thus, NGF-R is detected in a proportion of neuroectoderm-derived tumors, carcinomas, and lymphomas, and also in a characteristic group of small round-cell tumors (Ewing's sarcomas and embryonal rhabdomyosarcomas). These findings suggest a normal regulatory role for NGF in both neuronal and non-neuronal cells and identify a range of human tumors in which the NGF/NGF-R system may contribute to the malignant phenotype.

Aging↗

PubMed1988

Bacillus Calmette-Guérin therapy alters the progression of superficial bladder cancer.

The effectiveness of BCG in preventing disease progression in patients with superficial bladder cancer is evaluated. Long-term follow-up of high-risk patients treated in a previously reported randomized control trial of intravesical plus percutaneous BCG shows that progression occurred in 41/43 (95%) of control and 23/43 (53%) of BCG-treated patients. Muscle invasive and/or metastatic disease occurred with equal frequency in the two groups, but was significantly delayed by BCG treatment (P = .012). Cystectomies were required in 18/43 (42%) control and 11/43 (26%) BCG-treated patients. Median time to cystectomy was 8 months for control v 24 months for BCG-treated patients. Based on initial treatment, survival was improved by BCG therapy (P = .032) (median follow-up 6 years). These results suggest that in high-risk patients intravesical BCG can delay disease progression, prolong the period of bladder preservation, and increase overall survival.

Administration, Intravesical↗

PubMed1988

Demonstration of altered cellular DNA content distribution in long-term colon epithelial cell lines with colon cancer genotypes.

During prolonged culture (7-40 passages assayed) DNA distribution was constant in IVT-negative lines with FPC genotype and in IVT-negative lines without any known colon cancer genotype, whereas the DNA histograms of the IVT-positive lines with HNPCC genotype showed a marked change. The DNA index (DI) of greater than 1 increased sixfold in the HNPCC-A (affected) line and threefold in the HNPCC-AR (at-risk) line due to an equal increase in DI of 2 and DI of greater than 2. It is proposed that there is a possible association between the HNPCC genotype, the presence of IVT, and the marked increase in both DI of 2 and DI of greater than 2 in DNA histograms, since neither the lines with normal nor those with FPC genotypes showed these changes. The biological significance of IVT might be due to its influence on the constancy of the distribution of cellular DNA content, leading to aneuploidy, which has been known to precede in vitro tumorigenic phenotypes.

Adolescent↗

PubMed1988

T-cell subsets in peripheral blood of patients with newly diagnosed and posttreatment Hodgkin's and non-Hodgkin's lymphomas. Analysis by monoclonal antibody staining and flow cytometry.

T-cell subsets in the peripheral blood of patients with Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHLs) were determined using anti T-cell monoclonal antibodies and flow cytometry. Forty HD patients and 30 NHL patients were evaluated; 76 normal blood donors served as controls. Newly diagnosed (untreated) HD and NHL patients had relatively normal values for percentages of total T-cells, helper cells and suppressor cells; their helper/suppressor ratios were also normal. The total lymphocyte count was normal for pretreatment HD, but lower than normal for NHL. Following treatment, both HD and NHL patients showed significantly decreased helper/suppressor ratios, caused by a significant decrease in the percentage of helper cells in HD patients and a significant increase in the percentage of suppressor cells in the small number of NHL patients studied. A small number of NHL patients, followed without specific treatment (passive follow-up), had relatively normal values for percentages of helper and suppressor cells and total T-cells. For both groups of patients off treatment, it is concluded that the lower helper/suppressor ratios are due to the prolonged effects of treatment (predominantly irradiation).

Adult↗

PubMed1988

The relative value of cytometry and cytology in the management of bladder cancer: the Memorial Sloan-Kettering Cancer Center experience.

The flow cytometric studies presented herein are based almost entirely on DNA measurements and represent an early application of this diagnostic test. Nevertheless, the MSKCC experience with FCM has demonstrated that it is technically feasible and clinically useful. The sensitivity of FCM is in the range of 80% to 85% overall, and is superior to that of conventional voided or bladder wash cytology. In the absence of inflammation secondary to infection, calculi, or intravesical agents such as BCG, the specificity is greater than 90%. In the presence of inflammation, FCM appears to be less specific than conventional cytology. A potential advantage of FCM over cytology is the quantitative nature of the examination permitting comparisons of sequential examinations. Also, there are refinements in technique that hold promise of increasing the accuracy or clinical usefulness of FCM, eg, the joint measurements of DNA and differentiation antigens defined by monoclonal antibodies. Yet, despite the current and potential advantages of FCM, voided urinary cytology continues to be the procedure of choice for detection and monitoring urothelial carcinoma, not only because of our long experience and better understanding of this test, but because of its proven high specificity, because it is noninvasive, widely available, and may help to detect upper tract or urethral tumors.

Carcinoma, Transitional Cell↗

PubMed1987

The sensitivity of bladder wash flow cytometry, bladder wash cytology, and voided cytology in the detection of bladder carcinoma.

The sensitivity of voided urinary cytology (VUC), bladder wash cytology (BWC), and bladder wash flow cytometry (BWFCM) in detecting cancer was studied in 70 patients with biopsy-proven bladder tumors. There were 11 Grade I papillomas, 14 Grade II TA, 18 Grade II-III TIS, 19 Grade II-III T1, and eight Grade II-III T2 carcinomas. One to five VUCs per patient (mean, 2.63) were obtained within the 24 hours preceding biopsy. At endoscopy a bladder wash specimen was obtained and divided for cytologic and flow cytometric examinations. For all tumor categories combined, the sensitivity for one, two, and three voided cytology examinations per patient was 41%, 41%, and 60%, respectively. The sensitivity of a single BWC was 61%, of a single BWFCM, 83%. Thus, one BWFCM is more sensitive than three VUC (binomial test; P = 0.006); one BWC is more sensitive than two VUC (P = 0.01); and one BWFCM is more sensitive than one BWC (P = 0.003). These findings remain significant when papillomas are excluded from the analysis (P less than or equal to 0.03) and when papillomas and T2 tumors are jointly excluded (P less than or equal to 0.02). Only four of 70 patients (6%) had their cancers detected by VUC and/or BWC rather than BWFCM. In summary, irrigation cytology specimens are more sensitive than voided urinary cytology, and bladder wash flow cytometry is more sensitive than either in diagnosing bladder cancer. Flow cytometry is more sensitive because of the better sampling of bladder irrigation compared with voided urine and because of the measurement technique itself.

Biopsy↗

PubMed1987

Detection of lung cancer: highlights of the Memorial Sloan-Kettering Study in New York City.

1. Patients with Stage 1 lung cancer detected by cytology or x-ray, and treated by complete resection, have a high probability of survival. 2. Sputum cytology is effective in early detection of slow growing squamous (epidermoid) carcinomas of lung, which in our population account for less than one-third of cases. Without cytologic screening these cancers would be identified by annual chest x-rays at a later date, though still while localized and resectable. Thus, in a program of annual chest x-rays, conscientiously carried out, the addition of cytologic screening has no statistically significant effect on mortality. 3. Nearly half of all lung cancers in our population are adenocarcinoma, and early detection of these tumors is virtually restricted to the chest x-ray. Fifteen percent of cases are oat cell (small cell anaplastic) carcinoma, and these rapidly developing tumors are almost all discovered in an advanced stage with symptoms. 4. All participants in our study were offered annual chest x-rays, and no direct evaluation of the effect of radiographic screening on lung cancer mortality was possible. However, 40% of all lung cancers were detected in Stage 1, and at least two-thirds of patients with Stage 1 lung cancer treated by complete resection do not die of that disease. The overall five-year survival of patients enrolled in this program who developed lung cancer is 35%, in contrast to 13% for lung cancer in the United States as a whole. Survival at 10 years for all lung cancer patients in this screening program is 25%, and for those with Stage 1 lung cancer it is approximately 65%. 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

PubMed1987

The practical use of tumor marker determination in bladder washing specimens. Assessing the urothelium of patients with superficial bladder cancer.

Bladder washing specimens from 81 patients with recurrent multifocal superficial bladder cancer were evaluated for DNA profile by flow cytometry and cell-surface blood group (ABH) antigen reactivity by a modified specific erythrocyte adherence test. The study was conducted in a prospective, blind, nonrandomized fashion. Fifteen patients were treated with transurethral resection (TUR) alone and 66 with TUR and intravesical administration of bacillus Calmette-Guerin weekly for 6 weeks (TUR + BCG). Among the patients treated with TUR only, there was a notably greater rate of tumor recurrence and progression in patients with unfavorable tumor markers (aneuploidy and ABH-negative reactivity) than in those with favorable markers (diploidy and ABH-positive reactivity). The difference was less striking in patients treated with BCG, which reduced the frequency of recurrence or progression at 30 months from 87% to 44% and from 60% to 23%, respectively. This favorable effect of BCG was virtually confined to patients with initially favorable markers and to those whose initially unfavorable markers became favorable during BCG administration. Aneuploidy and negative ABH are phenotypic expressions of undifferentiation that can forecast the potential of the urothelium to form new tumors and predict invasion. To an extent, these markers are independent of the grade and stage of the disease. BCG can induce prognostically favorable conversion of the markers expression. Lack of such conversion indicates lack of response to BCG and should be regarded as evidence of persistent disease even if conventional methods do not reveal it. Therefore, sequential determination of markers is useful in monitoring patients with superficial bladder cancer treated with intravesical BCG.

Adult↗

PubMed1987

DNA in situ sensitivity to denaturation: a new parameter for flow cytometry of normal human colonic epithelium and colon carcinoma.

Modal DNA (ploidy) and sensitivity of DNA in situ to denaturation by acid have been analyzed by flow cytometry of 10 colorectal adenomas and 35 adenocarcinomas; 39 normal mucosa samples served as controls. A new method was developed to denature DNA in chromatin of the freshly isolated, intact, and unfixed individual cell nuclei from surgically resected material. The sensitivity of DNA denaturation (T alpha) was assayed by metachromatic staining with acridine orange and calculated as a ratio of the alpha t index of the tumor sample to the alpha t index of normal mucosa; the alpha t index is that fraction of DNA, following treatment at pH 1.4, that stains metachromatically with acridine orange at pH 2.6. All adenomas were diploid and in nine of 10 the T alpha value was close to 1.00, indicating no difference from control specimens in DNA sensitivity to denaturation. Forty-nine% of adenocarcinomas were aneuploid. Forty-six% of adenocarcinomas differed from normal in sensitivity of DNA to denaturation; the T alpha value was lower than 0.90 indicating that chromatin of the tumor cells was more resistant to denaturation than control cells. There was no correlation between sensitivity to denaturation of DNA and incidence of aneuploidy. However, there was a correlation between T alpha and the pathologically determined stage of disease. There was increased resistance to denaturation in 58% of tumors classified as Dukes' C/D stage, in 36% of tumors classified as Dukes' B, and in 20% classified as Dukes' A stage of the disease. Statistical analysis of these results revealed significant differences between distributions of T alpha in noninvasive (Adenomas and Dukes' A) versus invasive (Dukes' B and C/D) tumors with level of significance at P = 0.02. The data suggest that acid denaturation of DNA in situ may be a valuable adjunct in assessing the biology of colon cancer. The molecular basis for this phenomenon is discussed.

Acridine Orange↗