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D R Schwartz

Publications and source records attributed to D R Schwartz.

At least 19 recordsLinked to original sources
PubMed1992

Serial studies of autologous antibody reactivity to squamous cell carcinoma of the head and neck.

In previous studies we evaluated the incidence and specificity of autologous antibody reactivity against squamous cell carcinoma of the head and neck (SCCHN). We were able to demonstrate that autologous antibody reactivity is present in native sera but was usually of too low a titer to allow further analysis. Dissociation of immune complexes by acidification and ultrafiltration of serum augmented autologous antibody reactivity in nine out of nine autologous systems tested. Native antibody and antibody derived from immune complexes produced by the host and reactive with autologous tumor cells may be directed against physiologically relevant antigens. Therefore, correlations of antibody titers with clinical course may provide insight into the nature of the host response to cancer. In the present analysis, serological studies of six patients with SCCHN were performed with serum samples obtained over many months. Results of serial serological assays were correlated to tumor progression and clinical course. Fluctuations in autologous antibody reactivity were noted over time. In four cases, rises in autologous antibody titers preceded the clinical diagnosis of recurrence by several months. Drops in autologous antibody reactivity were noted in two cases following surgery or radiation therapy. In two cases of long-term survivors, no correlation between antibody reactivity and clinical course was noted. Specificity analysis of the six autologous systems demonstrated reactivity against autologous and allogeneic SCCHN as well as melanoma cell lines. These sera did not react with glioma, neuroblastoma, renal cell, breast, bladder and colon carcinoma cell lines nor with fetal calf serum, pooled lymphocytes, red blood cells and platelets. Autologous serial serological studies may provide a means by which to evaluate the host/tumor relationship in patients with SCCHN.

Aged↗
PubMed1992

Construct validity of the Dissociative Experiences Scale: II. Its relationship to hypnotizability.

Undergraduates (n = 311) who volunteered to participate in an experiment on "Hypnotizability and Personality" filled out several personality questionnaires (including the Dissociative Experiences Scale; DES), were administered the Harvard Group Scale of Hypnotic Susceptibility (HGSHS), and completed a self-rating of hypnotizability. The DES overall score correlated significantly with the HGSHS summary score (r(309) = .12, p < .05, two-tailed) and with subject's self-rating of hypnotizability (r(309) = .13, p < .05, two-tailed). The magnitude of these correlations was similar to that observed in a previous study (.14 & .18) and is also similar in magnitude to the correlations typically observed between the HGSHS and the Tellegen Absorption Scale. The potential clinical implications of these findings are discussed.

Adult↗
PubMed1991

In vitro radiation resistance among cell lines established from patients with squamous cell carcinoma of the head and neck.

Twenty-five squamous cell carcinoma (SCC) cell lines from 20 patients with head and neck cancer were assessed for radiosensitivity in vitro using a 96-well plate assay. Four non-SCC lines were also tested. Radiation sensitivity of individual cell lines was compared using the area under the survival curve (AUC) as a measure of the mean inactivation dose. Tumor lines were tested with either a cobalt-60 (60Co) gamma-irradiator having a dose rate of 100 cGy/minute or with a 4-meV photon beam having a dose rate of 200 cGy/minute. The mean AUC of the 25 SCC cell lines was 188 +/- 7 (SEM) cGy (range, 100 to 250 cGy) whereas the four non-SCC lines had a mean AUC of 225 +/- 9 cGy. The SCC cell lines with mean inactivation dose values greater than 188 cGy were classified as relatively radioresistant whereas those with values less than 188 cGy were considered relatively radiosensitive. In seven cases SCC cell lines were derived from patients who had already received radiation therapy. In four of these cases the tumor cell lines were radioresistant (AUC, 210 to 250) but in the other three cases the tumor lines were radiosensitive (AUC, 160 to 180). Thus, failure of a tumor to respond to radiation did not always select for radioresistant cells. The mean of the AUC for cell lines from previously irradiated patients (197 +/- 11 cGy) did not differ significantly from that of the cell lines from patients who received no prior radiation therapy (182 +/- 9 cGy). However, among radiation-resistant lines those from the four previously irradiated patients were significantly more resistant (mean AUC = 235 +/- 9) than seven other radioresistant lines from nonirradiated patients (mean AUC, 208 +/- 4) (P = 0.0194). In four cases more than one cell line was derived from different tumor specimens in the same patient. In each of these cases the lines from the same patients were similar to one another in their degree of radioresistance. Based on these observations the authors conclude that the degree of in vitro radiation resistance is an inherent property of some squamous cell tumors.

Adult↗
PubMed1991

Consistent chromosome abnormalities in squamous cell carcinoma of the vulva.

Six squamous cell carcinomas of the vulva (SCV) were karyotyped in short-term culture and in early passages as established cell lines. Each tumor was cytogenetically distinct, contained multiple chromosome rearrangements, and was karyotypically stable in culture. Heterogeneity within individual tumors was manifested by the presence of more than one clonal population, but the clones within each tumor were closely related to one another. Seven consistent chromosome abnormalities found in five of the six tumors were: losses of 3p14-cen, 8pter-p11, 22q13.1-q13.2, and the short arm of the inactive X; chromosome gains involving 3q25-qter and 11q21; and rearrangement breakpoints at 5cen-q12. Ten additional chromosome changes were observed in four of the six SCVs, and together, 22 changes occurred in at least three of the tumors. Two specific losses, 10q23-q25 and 18q22-q23, were present in all four tumors that exhibited biologically aggressive behavior in vivo, but these losses were not found in the tumors of the two long-term survivors. These findings indicate that: 1) SCVs are genetically complex, but homogeneous; 2) loss of 18q22-q23 and loss of 10q23-q25 may be associated with a poor prognosis; and 3) development and progression of SCV appear to result from cumulative effects of altered gene dosage at multiple, consistent loci.

Adult↗
PubMed1989

Characterization of human laryngeal primary and metastatic squamous cell carcinoma cell lines UM-SCC-17A and UM-SCC-17B.

The squamous cell carcinoma (SCC) cell lines UM-SCC-17A and -17B were derived, respectively, from the primary laryngeal cancer and a metastatic neck tumor of a patient who failed to respond to radiation therapy but achieved long-term remission after surgery. The karyotypes of both cell lines and a subline of 17A were pseudodiploid and stable in multiple in vitro passages. Several karyotypic abnormalities were common to all three cell lines and therefore represent mutations present in the tumor before the divergence of the metastatic and subline populations whereas those rearrangements observed only in one cell are more likely to be secondary. The shared mutations include: duplication of the short and proximal long arm of chromosome 2, isochromosome 3q, duplication 7, inversion 8, duplication of the distal long arm of 18, and monosomy 21 or ring 21. Each line had different rearrangements involving chromosome 7 that resulted in three copies of most of the short arm being present in both cell lines, except for high passages of 17B, in which one structurally normal 7 was replaced by a dicentric isochromosome, dic(7)(q11.22), resulting in four copies of 7p. The dic(7) may represent an in vitro mutation. An isochromosome 13q was noted in both the stemline and subline of UM-SCC-17A but not in UM-SCC-17B. A del(11p) and an iso(21q) were present only in the 17A subline. The cell lines expressed the membrane antigen phenotype characteristic of squamous cancers although the UM-SCC-17A subline differed with respect to three markers. Of these, the A9 and blood group antigen changes are thought to be associated with progression. The subline, which carried the del(11)(p13-p15.1), also failed to express the E7 antigen mapped to the band 11p13. It is possible that the two apparently normal 11s in this subline carry a point mutation or microscopically undetected deletion involving the E7 antigen locus.

Antigens, Neoplasm↗
PubMed1989

Clonogenic cell assay for anchorage-dependent squamous carcinoma cell lines using limiting dilution.

Clonogenic assays under either anchorage-dependent or -independent conditions are very useful for testing the sensitivity of tumor cells to cytotoxic drugs and radiation. These assays have not been widely used with squamous-cell carcinomas (SCC) because of poor tumor-cell viability and poor cloning efficiency, especially in semi-solid media. To find a clonogenic assay suitable for use with human squamous cancers we tested SCC lines, derived in our laboratory from patients with head and neck cancer, for the capacity to form colonies in soft agar and in 96-well plates. Of 13 UM-SCC lines tested for colony formation in agarose, only UM-SCC-11A was capable of growth in conventional semi-solid media. One other line, UM-SCC-14C, produced colonies in agarose only in the presence of epidermal growth factor. In contrast, all 17 of the SCC lines tested exhibited colony formation in adherent cell culture using limiting dilution in 96-well plates. The plating efficiencies of the SCC lines in the 96-well plate assay ranged from 0.02 to 0.52 colonies (wells)/cell whereas the PE values in soft agar were lower, ranging from 0.0055 to 0.0086 colonies/cell. The 96-well plate assay is not affected by cell migration, a problem encountered with some cell lines when clonogenic assays are performed in Petri dishes. UM-SCC-11A was tested for radiation sensitivity both in soft agar and in the 96-well plate assay. Comparable results were obtained. In summary, the majority of SCC cell lines did not form viable colonies in soft agar but the 96-well plate assay was applicable to a broad spectrum of anchorage-dependent human SCC cell lines and provides an efficient method for evaluating clonogenic cell survival.

Agar↗
PubMed1989

Incidence of serum antibody reactivity to autologous head and neck cancer cell lines and augmentation of antibody reactivity following acid dissociation and ultrafiltration.

Serum antibody reactivity to squamous cell carcinoma of the head and neck (SCCHN) was evaluated in 41 autologous serum-tumor cell line combinations using the protein A hemadsorption assay. Autologous antibody reactivity (median titer of 1:4) was detected in sera from 24 of the patients tested. In 10 cases autologous antibody reactivity could be detected only in undiluted serum precluding further analysis. Analysis of higher titer sera from one patient revealed antibodies that define an antigen expressed on autologous tumor cells cultured from both the primary tumor (UM-SCC-17A) and from a metastasis (UM-SCC-17B). Absorption analysis showed that this antigen was also expressed on 6 of 10 allogeneic SCCHN cell lines but not on autologous fibroblasts or on allogeneic melanoma cell lines. Due to the low titer of autologous antibody reactivity in most sera, we sought to determine if dissociation of immune complexes through acidification and ultrafiltration of serum might enhance detectable antibody reactivity as has been done in previous studies in melanoma. Twelve serum samples from eight patients were subjected to acid dissociation and ultrafiltration (AD-U). Only six of the untreated sera had detectable antibody reactivity against the autologous SCCHN cell line whereas following AD-U all 12 sera had enhanced IgG reactivity against autologous SCCHN. Specificity analysis of one serum sample after dissociation revealed that the antibody detected an antigen common to SCCHN cell lines as well as melanoma, glioma, renal, and colon carcinoma cell lines. Circulating immune complexes may provide a reservoir of antibody with potential diagnostic and therapeutic applications.

Antibodies, Neoplasm↗
PubMed1988

Biosynthesis and secretion of laminin and laminin-associated glycoproteins by nonmalignant and malignant human keratinocytes: comparison of cell lines from primary and secondary tumors in the same patient.

Laminin biosynthesis was compared in four pairs of human squamous cell carcinoma cultures derived from primary and recurrent or metastatic tumors in four patients with cancer of the larynx and hypopharynx to determine if changes in laminin production accompany tumor progression. Laminin profiles of the malignant cells were compared with laminin biosynthesized by nonmalignant human keratinocytes. Pulse-chase biosynthetic labeling of the cultures with [35S]methionine established that all of the squamous carcinoma cell lines synthesize immunoreactive A (Mr 400,000), B1 (Mr 205,000), and B2 (Mr 200,000) laminin subunits; assemble them to form the intact laminin molecule (Mr 950,000); and secrete a portion of the laminin they produce into the culture media. One aspect of laminin expression unique to keratinocytes, both malignant and nonmalignant, was the occurrence of three additional glycoprotein forms (Mr 195,000, 170,000, and 160,000) in the laminin immunoprecipitates. In contrast to the laminin subunits, these glycoproteins were not immunoreactive with the anti-laminin antiserum on Western blots. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis without and with reduction of disulfide bonds revealed that the laminin immunoprecipitates contained a family of oligomeric molecules. These ranged in apparent molecular weight from 370,000 to 950,000 and were composed of laminin subunits and the glycoprotein forms linked by interchain disulfide bonds. The malignant keratinocyte cell lines from different patients were distinguishable in terms of the array of laminin and glycoprotein forms displayed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the rate of [35S]methionine incorporation into laminin during the pulse-labeling, the fraction of [35S]methionine-labeled laminin secreted into the medium during the chase incubation, and the absolute amount of laminin secreted into the culture medium as determined by enzyme-linked immunosorbent assay. However, cell lines established from primary and metastatic or recurrent cancer in the same patient were indistinguishable in their profile of laminin biosynthesis and secretion. In comparison to primary cultures of nonmalignant foreskin basal keratinocytes, the malignant cells secreted into the culture medium a larger fraction of the laminin that they produce. This is an indication that the malignant keratinocytes in culture deposited a less stable basal lamina-like extracellular matrix than their malignant counterparts. The diminished integrity of the basal lamina matrix may be an important factor in the invasive growth of human epithelial cancer.

Carcinoma, Squamous Cell↗
PubMed1988

UM-EC-1, a new hypodiploid human cell line derived from a poorly differentiated endometrial cancer.

The University of Michigan endometrial carcinoma cell line UM-EC-1 was derived from a poorly differentiated endometrial adenocarcinoma of a 66-yr-old white female. Cell cultures were started using both tumor explants and a cell suspension obtained from collagenase-treated tumor tissue. The collagenase-derived cell suspension gave rise to monolayer cultures which grew rapidly from the outset. This subline of UM-EC-1 has now been subcultured more than 50 times. Cells derived from the tumor explants grew more slowly initially, but after a lag phase of 5 to 6 wk, this subline also exhibited rapid logarithmic growth and reached the same growth rate as that of the collagenase-treated cells. The explant subline has been subcultured more than 37 times. The doubling time of both sublines is 24 h under optimal growth conditions. The karyotype of both cell cultures is 43, XX, inv(1)(p32q42), -4, +der(8) t(8;12)(p23.1;q22), del(9)(q11), -13, -13, +t(13;13) (p13;p13), del(18)(q), -19, -22, -22, +t(22;22)(p11;p11). The net result of the chromosome losses and rearrangements was monosomy 4, duplication 8p23.1----qter, deletion 9q11----9qter, duplication 12q22----qter, deletion 18q, and monosomy 19. The t(13;13) and the t(22;22) were dicentric by C-banding. Virtually all of the chromosome changes were stable in multiple passages except that there was mosaicism for chromosome 13. Some cells contained a single copy of 13 and others had t(13;13). The available evidence indicates the t(13;13) is an isochromosome. UM-EC-1 cells produced tumors histologically similar to the original tumor in male, female, and ovariectomized female athymic mice. UM-EC-1 cells express human class I histocompatibility antigens as assessed by binding of antibodies to nonpolymorphic HLA and beta-2-microglobulin antigens. Blood group antigens A and H were absent although the patient is blood type A and these antigens are normally expressed in endometrial glands. A rearrangement involving the region of chromosome nine that carries the ABH locus may be related to the absence of blood group antigen expression by these cells. The E7 membrane antigen, the locus for which resides on the short arm of chromosome 11, was expressed strongly which is consistent with the presence of two intact copies of chromosome 11 in these cells.

Aneuploidy↗
PubMed1985

DNA content of human squamous cell carcinoma cell lines. Analysis by flow cytometry and chromosome enumeration.

Fifteen squamous cell carcinoma cell lines derived from nine patients were examined for DNA content by flow cytometry and chromosome counts. Using human peripheral blood leukocytes and nucleated trout and chicken red blood cells as standards, the DNA indexes of the squamous cell carcinoma cell lines were found to range from 1.1 to 3.3. The DNA content was a stable characteristic of individual cell lines in multiple passages over a seven-month period. Although flow cytometry could detect abnormal DNA content even in diploid tumor lines, the chromosome number correlated well with the DNA content by flow cytometry. In cases in which more than one cell line was established from the same patient, the individual cell lines were found to differ in their DNA content. The cell lines established from metastatic or recurrent tumors usually had a lower DNA content and chromosome number and exhibited a more aggressive in vitro growth pattern than the primary tumor or earlier recurrence. We hypothesize that "streamlined" and aggressive cell populations may evolve in vivo from more slowly growing hyperploid precursor tumor cell populations when in the course of random loss of DNA or chromosomes those that confer no growth advantage are lost, while those that do confer growth advantage are retained.

Animals↗
PubMed1985

Involvement of oxidative damage in erythrocyte lysis induced by amphotericin B.

Lysis of human erythrocytes induced by amphotericin B was retarded when the oxygen tension of the incubation mixture was reduced or when the antioxidant catalase was added; lysis was accelerated when cells were preincubated with the prooxidant ascorbate. In the atmosphere of reduced oxygen tension, the erythrocytes containing carboxyhemoglobin lysed at a slower rate than did the cells containing oxyhemoglobin. Consistent with a role for oxidative damage in lysis, the mixture of erythrocytes and amphotericin B showed an increase in malonyldialdehyde, the product of peroxidation, which paralleled the progression of hemolysis. In contrast, the permeabilizing effect of amphotericin B, measured as a decrease in intracellular K+, was not affected by changes in oxygen tension, catalase, or ascorbate treatment. These results imply that oxidant damage is involved in the lytic, but not in the permeabilizing, action of amphotericin B.

Amphotericin B↗
PubMed1983

Antibodies to human squamous cell carcinoma.

We are studying membrane antigens of human squamous cell cancer with the use of naturally occurring autologous antibodies from patients' sera, along with a set of other serologic reagents and monoclonal antibodies raised against cultured squamous cell lines. Twenty-eight squamous cell carcinoma cell lines have been established in our laboratory from tissues obtained from 23 patients. Antibody reactivity has been found against the autologous tumor cell line in 13 of 23 patients. One of these is of sufficient titer for detailed analysis. Four cell lines are available from this patient. UM-SCC-17A is derived from the primary laryngeal carcinoma, and UM-SCC-17B is derived from a lymph node metastasis removed during the same surgical procedure. Fibroblasts have been cultured from normal mucosa, and a B-lymphoblastoid line has been developed by Epstein-Barr virus transformation of the patient's peripheral blood lymphocytes. Antibody from this patient reacts with the UM-SCC-17A and -17B tumor cell lines but does not react with the normal fibroblasts (UM-NF-17).

Antibodies, Monoclonal↗