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M Stetler-Stevenson

Publications and source records attributed to M Stetler-Stevenson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Immunophenotypic analysis of non-Hodgkin's lymphomas in cytologic specimens: a correlative study of immunocytochemical and flow cytometric techniques.

Most Non-Hodgkin's lymphomas(NHL) can be accurately diagnosed and classified based on morphologic and immunophenotypic findings on cytologic specimens. Immunophenotyping can be accomplished via immunocytochemistry (IC) or flow cytometry (FC). We reviewed our experience with 98 cytology specimens (70 fine-needle aspirates [FNA] and 28 effusions) that were submitted for immunophenotyping utilizing both IC and FC between January 1992 and December 1997 for the diagnosis of NHL. Eighty-five percent of the cases were immunophenotyped by both techniques. Among these there were only two discrepancies between IC and FC, yielding a 98% correlation rate. Of the 98 cases, 11% could not be immunophenotyped by FC and 4% could not be immunophenotyped by IC. The advantage of IC is the preservation of cytomorphology, which results in the requirement for a lower number of neoplastic cells and a limited, targeted panel of antibodies. This is especially useful in predominantly necrotic lymphomas in which only a few well-preserved neoplastic cells may be present, rendering the specimen inadequate for immunophenotyping by FC. The advantages of FC are in the detection of a small population of monoclonal cells in a background of reactive cells (particularly useful in effusion samples in which the predominant cell population is often reactive T lymphocytes), increased diagnostic precision through evaluation of objective parameters, and the use of multiple markers with dual labelling. We conclude that IC and FC are both excellent methods for immunophenotyping of cytology specimens and can be used interchangeably depending on the institutional expertise and availability.

Biopsy, Needle↗
PubMed1998

In vitro suppression of programmed cell death of B cells by tissue inhibitor of metalloproteinases-1.

Cellular pathways for induction of programmed cell death (PCD) have been identified, but little is known about specific extracellular matrix processes that may affect apoptosis along those pathways. In this study, a series of Burkitt's lymphoma (BL) cell lines were assayed for their expression of tissue inhibitor of metalloproteinases (TIMP)-1. Results indicate that TIMP-1-positive BL lines show resistance to cold-shock-induced apoptosis. Furthermore, recombinant TIMP-1, but not TIMP-2 or a synthetic metalloproteinase inhibitor (BB-94), confers resistance to apoptosis induced by both CD95-dependent and -independent (cold shock, serum deprivation, and gamma-radiation) pathways in TIMP-1-negative BL lines. TIMP-1 suppression of PCD is not due to metalloproteinase inhibition, as reduction and alkylation of the TIMP-1 did not abolish this activity. Retroviral induction of TIMP-1 not only resulted in cell survival but also in continued DNA synthesis for up to 5 d in the absence of serum, while controls underwent apoptosis. This resistance to apoptosis is reversed by anti-TIMP-1 antibodies, demonstrating that secreted TIMP-1 is active in blocking apoptosis. Furthermore, TIMP-1 upregulation induced expression of Bcl-XL but not Bcl-2 as well as decreased NF-kappaB activity as compared with controls. These results demonstrate that TIMP-1 suppresses apoptosis in B cells and suggests a novel activity for TIMP-1 in tissue homeostasis.

Apoptosis↗
PubMed1998

Tissue inhibitor of metalloproteinase (TIMP)-1 induces differentiation and an antiapoptotic phenotype in germinal center B cells.

Tissue inhibitors of metalloproteinases (TIMPs) have been shown to be multifunctional factors. Contrasting with their enzyme-inhibitory activity, TIMPs also promote cell growth. Previously, we have reported an enhanced expression of TIMP-1 by normal reactive B cells and high-grade lymphomas. In the present study, a series of Burkitt's lymphoma (BL) cell lines were analyzed for their expression of TIMP-1. TIMP-1 expression correlates with upregulation of activation and survival markers. TIMP-1-negative cells express the phenotype associated with group I BL lines and Epstein-Barr virus (EBV)-negative, nonendemic BLs (CD10+, CD38+, sIg+, and CD77+). However, TIMP-1+ BL lines showed group II/III BL phenotype, downregulation of the above markers, and upregulation and secretion of the activation marker CD23. Also, TIMP-1+ cells have high levels of CD40 expression. To determine whether TIMP-1 is directly involved in the BL phenotype, an EBV-negative BL line JD38 was infected with timp-1-expressing retrovirus and analyzed. In the absence of EBV, upregulation of TIMP-1 is sufficient to induce the same phenotype seen in TIMP-1+, EBV+ BL lines (CD10-, CD38-, sIg-, CD77-, CD23+, CD40 bright). This study not only suggests a role for TIMP-1 in BLs, but also supports its value as a prognostic factor. This is a US government work. There are no restrictions on its use.

Apoptosis↗
PubMed1998

Pathological findings in human autoimmune lymphoproliferative syndrome.

The defects in lymphocyte apoptosis that underlie the autoimmune lymphoproliferative syndrome (ALPS) are usually attributable to inherited mutations of the CD95 (Fas) gene. In this report, we present the histopathological and immunophenotypic features seen in the lymph nodes (n = 16), peripheral blood (n = 10), bone marrow (n = 2), spleen (n = 3), and liver (n = 2) from 10 patients with ALPS. Lymph nodes showed marked paracortical hyperplasia. Interfollicular areas were expanded and populated by T cell receptor-alphabeta CD3+ CD4-CD8- (double-negative, DN) T cells that were negative for CD45RO. CD45RA+ T cells were increased in all cases studied. The paracortical infiltrate was a result of both reduced apoptosis and increased proliferation, as measured by in situ detection of DNA fragmentation and staining with MIB-1, respectively. The paracortical proliferation may be extensive enough to suggest a diagnosis of malignant lymphoma. Many of the paracortical lymphocytes expressed markers associated with cytotoxicity, such as perforin, TIA-1, and CD57. CD25 was negative. In addition, most lymph nodes exhibited florid follicular hyperplasia, often with focal progressive transformation of germinal centers; in some cases, follicular involution was seen. A polyclonal plasmacytosis also was present. The spleens were markedly enlarged, more than 10 times normal size. There was expansion of both white pulp and red pulp, with increased DN T cells. DN T cells also were observed in liver biopsies exhibiting portal triaditis. In the peripheral blood, the T cells showed increased expression of HLA-DR and CD57 but not CD25. CD45RA+ T cells were increased in the four cases studied. Polyclonal B cell lymphocytosis with expansion of CD5+ B cells was a characteristic finding. Taken together, the histopathological and immunophenotypic findings, particularly in lymph nodes and peripheral blood, are sufficiently distinctive to suggest a diagnosis of ALPS. Of note, two affected family members of one proband developed lymphoma (T-cell-rich B-cell lymphoma and nodular lymphocyte predominance Hodgkin's disease, respectively).

Apoptosis↗
PubMed1998

Haematological response of patients with myelodysplastic syndrome to antithymocyte globulin is associated with a loss of lymphocyte-mediated inhibition of CFU-GM and alterations in T-cell receptor Vbeta profiles.

We have demonstrated that 44% of myelodysplastic syndrome (MDS) patients with cytopenia have a haematological response to antithymocyte globulin (ATG). Three ATG responders and two non-responders with refractory anaemia were further studied for lymphocyte-mediated inhibition of bone marrow using a standard CFU-GM assay. In responders, peripheral blood lymphocytes (PBL) added at a 5:1 ratio suppressed CFU-GM by 54+/-9% (P=0.04) and was reversed by ATG treatment. Pre-treatment marrow depleted of CD3 lymphocytes, increased CFU-GM by 32% (P=0.02) in an ATG responder, but not in a non-responder. CD3 lymphocytes from 6-month post-treatment marrow did not inhibit pre-treatment CFU-GM, indicating ATG had affected the T cells. Pre-treatment marrow depleted of CD8 lymphocytes, increased CFU-GM by 60% (P=0.01) and 49% (P=0.03) in two ATG responders, but not in a non-responder. Inhibition required cell-cell interaction through MHCI. TCRVbeta families, analysed by SSCP, changed from clonal to polyclonal in one ATG responder after 6 months, but clones persisted in a non-responder. These results indicate patients with refractory anaemia who respond to ATG have CD8 T-cell clones that mediate MHCI-restricted suppression of CFU-GM which are replaced by polyclonal T cells that do not suppress CFU-GM after ATG treatment.

Adult↗
PubMed1997

Inhibition of cyclin D expression in human breast carcinoma cells by retinoids in vitro.

Transfection and transgenic mouse experiments supported an oncogenic role for cyclin D1 in breast cancer. We recently reported that noninvasive carcinoma in situ lesions of the human breast overexpress cyclin D, suggesting that this molecular event may represent a valuable target for chemoprevention. The purpose of the present series of investigations was to identify agents which could reduce the cyclin D expression of breast cells. We report that 9-cis retinoic acid (9-cis RA) and all trans retinoic acid (tRA) inhibited the cyclin D1 and D3 expression levels of human MCF-7, ZR-75 and T-47D breast carcinoma cells in vitro. Where detectable, similar trends were observed in the immortalized, HBL-100 and MCF-10A breast cell lines. Cyclin D2 was undetectable. The effect of retinoids was both dose- and time-dependent, and correlated with altered cell cycle kinetics and proliferative status. Retinoids were also found to inhibit the expression levels of other cell cycle related proteins, including Cdk2 and Cdk4, resulting in lower kinase activities. In contrast to other breast prevention studies, no synergistic effect was observed with retinoids and tamoxifen. The data indicate that retinoids can potently reduce cyclin D expression levels in a variety of breast cell lines in vitro, and suggest further consideration of this mechanism for the chemoprevention of breast cancer.

Breast Neoplasms↗
PubMed1997

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in reactive and neoplastic lymphoid cells.

We have studied the expression of gelatinase A, gelatinase B, interstitial collagenase, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in reactive lymphoid cells, as well as in a series of cell lines derived from neoplasms of B- and T-cell lineage. Using both Northern blot analysis and zymography, gelatinase B activity was detected by zymography in two Burkitt cell lines and in a tonsillar cell suspension, while gelatinase A and interstitial collagenase activities were not detected by either method. TIMP-1 expression was demonstrated by Northern blot analysis in the multipotential neoplastic K-562 cell line, the high grade Burkitt's B-cell lymphoma lines, isolated tonsillar B cells and at low levels in peripheral blood T cells, but was not expressed in any of the neoplastic T-cell lines or isolated peripheral blood B cells. In contrast, TIMP-2 expression was restricted to tissues containing cells of T-cell lineage with high levels being observed in the neoplastic T-cell lines and lower levels in normal peripheral blood T cells and hyperplastic tonsil. Expression of TIMP-1 and TIMP-2 was confirmed at the protein level by reverse zymography and immunofluorescence assays using antihuman TIMP polyclonal antibodies. Expression of gelatinase B by the high grade B-cell Burkitt's lymphoma cell lines is consistent with previous findings in large cell immunoblastic lymphomas and indicates that this enzyme may play an important role in high grade non-Hodgkin's lymphomas. TIMP expression correlated with cell lineage in that TIMP-1 was primarily observed in B cells and TIMP-2 was restricted to T cells.

B-Lymphocytes↗
PubMed1997

Flow cytometric cell sorting combined with molecular chimerism analysis to detect minimal recurrent leukemia: good news and bad news.

Allogeneic BMT offers the possibility of cure for a variety of hematopoietic malignancies, but disease relapse remains a major cause of treatment failure. This report describes two cases in which flow cytometric cell sorting (FACS) and molecular chimerism analysis were combined to increase the sensitivity of minimal residual disease (MRD) detection. In the first case this approach was used to demonstrate that a suspicious phenotype was not recurrent leukemia, thus preventing the use of potentially toxic therapy. In the second case the recurrence of a leukemia which was undetectable by conventional analysis was confirmed. The potential benefits of combining these MRD detection methods are discussed.

Adolescent↗
PubMed1997

The activated anaplastic lymphoma kinase increases cellular proliferation and oncogene up-regulation in rat 1a fibroblasts.

More than 60% of anaplastic large-cell lymphomas (Ki-1 lymphoma) are associated with a t(2;5)(p23;q35) translocation that produces an 80 kDa hyperphosphorylated chimeric protein (p80) derived from the fusion of the anaplastic lymphoma kinase (ALK) with nucleophosmin (NPM). The NPM-ALK chimeric gene is an activated tyrosine kinase that has been shown to be a potent oncogene. We have developed a cellular model for the study of p80 action in rat 1a fibroblasts. Expression of cDNA's encoding NPM-ALK (p80) in rat 1a fibroblasts induces anchorage-independent growth in soft agar and promotes foci formation in culture. Cells expressing exogenous p80 showed significantly increased proliferation characterized by accelerated cell cycle entry into S-phase. Consistent with increased G0/G1 to S-phase transition, there is also marked up-regulation of cyclin A and cyclin D1 expression. In addition, p80 transformed cells showed elevated expression of several immediate early genes involved in cellular proliferation, including fos, jun, and c-myc. DNA binding analysis of nuclear extracts prepared from p80 transformed cells reveal marked up-regulation of AP-1 DNA binding activity. Functional AP-1-specific transfection assays also show up-regulation of AP-1-dependent transcriptional activation. These finding demonstrate that p80 transformed rat 1a fibroblast can be a highly useful model system for the molecular and biochemical characterization of the mechanisms of action of this interesting new oncogene.

Anaplastic Lymphoma Kinase↗
PubMed1996

Flow cytometric analysis of kappa and lambda light chain expression in evaluation of specimens for B-cell neoplasia.

Analysis of light chain expression is one of the most important determinations in flow cytometric immunophenotyping of patient specimens. Numerous technical factors, such as antibody choice and cytophilic antibody artifact, impact a laboratory's ability to perform this test. There have been conflicting reports concerning the efficacy of polyclonal versus monoclonal antibodies, as well as methods of circumventing cytophilic antibodies, indicating that a consensus has not been reached on optimal methods for light chain determination. The authors have investigated methods for light chain analysis in 104 normal donors and 366 patient specimens, comparing different anti-light chain antibodies as well as strategies for analysis of specimens with low numbers of monoclonal B cells, admixed polyclonal B cells, or cytophilic antibodies. The patient specimens were either part of the initial diagnostic evaluation of patients with suspected lymphoma, or were performed for staging or assessment of treatment of patients with known B-cell neoplasia. No monoclonality was detected in control specimens, and there was no significant difference in staining with monoclonal verses polyclonal anti-light chain antibodies. In addition, cytophilic antibody did not obscure results in normal controls. Monoclonality was detected in 106 patient specimens, with 89 showing gross involvement with a predominant monoclonal B-cell process. However, in 43% of the grossly monoclonal specimens, there was failure to detect monoclonality with at least one light chain antibody set, with 8% of these cases showing failure with two anti-light chain sets. This indicates the importance of antibody choice in light chain analysis. Cytophilic antibody artifact in monoclonal specimens was easily overcome by appropriate antibody combinations, obviating the need for cytophilic antibody-shedding by incubation at 37 degrees C in fetal calf serum. In 27 patient specimens with low numbers of B cells or admixed polyclonal B cells, a clonal search based on FSC and CD19 or CD20 expression was performed. In 17 of the 27 cases (63%), a small monoclonal population was detected among admixed polyclonal B cells. The authors conclude that multiple strategies are necessary in flow cytometric analysis for B-cell monoclonality.

Antibodies, Monoclonal↗
PubMed1996

Hepatosplenic T-cell lymphoma: a distinct clinicopathologic entity of cytotoxic gamma delta T-cell origin.

We identified eight cases of T-cell lymphoma with evidence of a gamma delta phenotype over a 13-year period. Seven of these cases conformed to a distinct clinicopathologic entity of hepatosplenic gamma delta T-cell lymphoma. Nearly all of these patients were young adult males (five of seven), with a median age at presentation of 20 years. They presented with marked hepatosplenomegaly, without lymphadenopathy or significant peripheral blood lymphocytosis. Thrombocytopenia was seen in all patients, and five of seven were mildly anemic. The clinical course was aggressive, and despite multiagent chemotherapy, the median survival duration was less than 1 year. The morphologic findings were uniform; a monomorphic population of medium-sized lymphoid cells with moderately clumped chromatin and a rim of pale cytoplasm infiltrated the sinusoids of the spleen, liver, and bone marrow. The cells had a characteristic immunophenotype: CD2+, CD3+, CD4-, CD5-, CD7+, CD16+, CD57-, CD25-, T-cell receptor (TCR)delta +, beta F1-. CD8 was positive in four of seven cases tested, and CD56 was positive in five of six. All cases expressed the cytotoxic granule-associated protein, TIA1, but perforin was detected in only one case. All cases with assessable DNA had a TCR gamma gene rearrangement, and lacked Epstein-Barr virus sequences. Isochromosome 7q was identified in two cases with cytogenetic information. The one case of cutaneous gamma delta T-cell lymphoma differed in its clinical manifestations, histologic appearance, and immunophenotype. We conclude that hepatosplenic gamma delta T-cell lymphoma is a distinct clinicopathologic entity derived from cytotoxic gamma delta T cells, and should be distinguished from other lymphomas of T-cell and natural-killer cell (NK)-like T-cell derivation.

Adolescent↗
PubMed1996

A phase I study of bolus versus continuous infusion of the anti-CD19 immunotoxin, IgG-HD37-dgA, in patients with B-cell lymphoma.

IgG-HD37-SMPT-dgA is a deglycosylated ricin A chain (dgA)-containing immunotoxin (IT) prepared by conjugating the monoclonal murine (MoAb) anti-CD19 antibody, HD37, to dgA using the heterobifunctional hindered disulfide linker, N-succinimidyl-oxycarbonyl-alpha-methyl-alpha-(2-pyridyldithio) toluene (SMPT). In this report, we have used two regimens for the administration of IgG-HD37-SMPT-dgA to patients with non-Hodgkin's lymphoma (NHL) in two concomitant phase I trials. One trial examined four intermittent bolus infusions administered at 48-hour intervals. The other studied a continuous infusion (CI) administered over the same 8-day period. In the intermittent bolus regimen, the maximum tolerated dose (MTD) was 16 mg/m2/8 d and the dose-limiting toxicity (DLT) consisted of vascular leak syndrome (VLS), aphasia, and evidence of rhabdomyolysis encountered at 24 mg/m2/8 d. Using the CI regimen, the MTD was defined by VLS at 19.2 mg/m2/8 d. At the MTD of both regimens, a novel toxicity, consisting of acrocyanosis with reversible superficial distal digital skin necrosis in the absence of overt evidence of systemic vasculitis, occurred in 3 patients. Of 23 evaluable patients on the bolus schedule, there was 1 persisting complete response (CR; > 40 months) and 1 partial response (PR). Of 9 evaluable patients on the continuous infusion regimen, there was 1 PR. Pharmacokinetic parameters for the bolus regimen at the MTD showed a mean maximum serum concentration (Cmax) of 1,209 +/- 430 ng/mL, with a median T1/2 beta for all courses of 18.2 hours (range, 10.0 to 80.0 hours), a volume of distribution (Vd) of 10.9 L (range, 3.1 to 34.5 L), and a clearance (CL) of 0.45 L/h (range, 0.13 to 2.3 L/h). For the CI regimen at MTD, the mean Cmax was 963 +/- 473 ng/mL, with a median T1/2 beta for all courses of 22.8 hours (range, 24.1 to 30.6 hours), a Vd of 9.4 L (range, 4.4 to 19.5 L), and a CL of 0.32 L/h (range, 0.12 to 0.55 L/h). Twenty-five percent of the patients on the bolus infusion regimen and 30% on the CI regimen made antibody against mouse Ig (HAMA) and/or ricin A chain antibody (HARA). We conclude that this IT can be administered safely and that both regimens achieve comparable peak serum concentrations at the MTD; these concentrations are similar to those achieved previously using other regimens with IgG-dgA ITs at their respective MTDs. Thus, toxicity is related to the serum level of the IT and does not differ with different targeting MoAbs.

Adult↗
PubMed1996

Gene-specific repair in human CD4+ lymphocytes reflects transcription and proliferation.

We have measured the gene-specific repair of ultraviolet irradiation (UV)-induced cyclobutane pyrimidine dimers (CPD) in freshly isolated human peripheral blood CD4+ T-lymphocytes. Two populations of CD4+ lymphocytes were assayed: resting and proliferating cells. DNA repair was assessed in the essential gene dihydrofolate reductase (DHFR) as well as in each of its strands, in the proliferation inducible c-myc gene and in the inactive delta-globin gene. Transcription rates in these genes were determined by nuclear run-on assay in the two cell populations. The rate of DHFR transcription increased 10-fold from resting to proliferating lymphocytes. Transcripts from c-myc were present only in proliferating cells, and we detected no delta-globin transcripts in either cell population. During the 24-h period after UV irradiation, there was little or no repair in any of the genes in the resting cells; there was some repair in the transcribed strand of the DHFR gene, but no repair in its nontranscribed strand. In the proliferating cells where the transcription of DHFR was much increased, the repair was efficient. The delta-globin gene was not expressed in either cell population, but it was more efficiently repaired in the proliferating than in the resting cells. We suggest that the gene-specific repair activity in CD4+ lymphocytes can reflect the proliferative state of the cells as well as the transcriptional state of the gene.

Autoradiography↗
PubMed1996

Use of the polymerase chain reaction technique to determine c-myc expression in follicular center cell lymphoma.

We determined, in a semiquantitative fashion, the level of expression of c-myc in 18 follicular center cell lymphomas and five non-neoplastic lymph nodes using reverse transcription and the polymerase chain reaction technique (RT-PCR). With this method, RNA is extracted from lymph node specimens and reverse-transcribed to produce cDNA, which is then amplified using primers specific for c-myc sequences that span introns, thus precluding amplification of genomic DNA. Amplified products are compared with beta2-microglobulin sequences co-amplified in each case as a control for the quality of RNA extracted, RT, and PCR amplification. Using cell lines derived from Burkitt's lymphomas, the RT-PCR method yielded results equivalent to standard Northern blot analysis yet required smaller quantities of tissue. The c-myc transcripts were detected in all lymphoma cases studied (seven high, 11 low expression) and in all non-neoplastic lymph nodes. High or low c-myc expression was based on comparison with non-neoplastic lymph nodes. We conclude that the RT-PCR method is a sensitive, reliable method for measuring gene expression in lymphoma tissues and may be useful for studying the role of c-myc in follicular lymphomas.

Adult↗
PubMed1996

TNF-alpha and IL-1 alpha induce mannose receptors and apoptosis in glomerular mesangial but not endothelial cells.

The macrophage mannose receptor, a carbohydrate-binding membrane protein, mediates endocytosis and phagocytosis. This study was undertaken to determine whether mannose receptors were expressed in resting glomerular mesangial and endothelial cells and whether their level was affected by cytokines. Neither mannose receptor mRNA nor proteins were found in resting mesangial or endothelial cells. Mannose receptor mRNA was induced in a dose- and time-dependent manner in mesangial cells by interleukin-1 alpha (IL-1 alpha) or tumor necrosis factor-alpha (TNF-alpha) but not by platelet-derived growth factor-B or IL-6. Cell surface receptors were found by fluorescence-activated cell sorter analysis. Binding to stimulated mesangial cells was saturable and inhibited by excess mannose-bovine serum albumin (BSA) but not by galactose-BSA. TNF-alpha and IL-1 alpha also induced apoptosis in mesangial cells. Mannose receptor expression was not restricted to apoptotic stimulated mesangial cells. Neither agonist induced mannose receptor expression or apoptosis in endothelial cells. Because immunoglobulin A, M, and G contain mannose residues, immune aggregates may be removed from the mesangium through cytokine-induced mannose receptors.

Animals↗