Loss of cell cycle control allows selective microtubule-active drug-induced Bcl-2 phosphorylation and cytotoxicity in autonomous cancer cells.

Lack of selectivity in the killing of tumor and normal cells is a major obstacle in cancer therapy. By inhibiting normal but not autonomous cell growth, we exploited the differences in cell cycle regulation to achieve a selective protection of nonautonomous cells against paclitaxel and other microtubule-active drugs. Tubulin polymerization, a primary effect of paclitaxel, can be dissociated from Bcl-2 phosphorylation and cytotoxicity in HL-60 cells. Growth arrest prevented paclitaxel-induced Bcl-2 phosphorylation and apoptosis without affecting paclitaxel-induced tubulin polymerization. We abrogated the effects of paclitaxel on MCF-10A immortalized breast cells, while preserving its effects on MCF-7 cancer cells. Unlike MCF-7 cells, MCF-10A cells were arrested by epidermal growth factor withdrawal, precluding paclitaxel-induced Bcl-2 phosphorylation. Furthermore, the inhibition of the epidermal growth factor receptor kinase with low doses of AG1478 arrested growth of MCF-10A but not MCF-7 cells. Pretreatment with AG1478 did not affect paclitaxel-induced Bcl-2/Raf-1 phosphorylation in MCF-7 but abrogated such phosphorylation in MCF-10A. Exploitation of growth factor dependency may allow the protection of normal cells from microtubule-active drugs.

CNS involvement in primary mediastinal large B-cell lymphoma.

PURPOSE: The risk of CNS involvement by non-Hodgkin's Lymphoma (NHL) has been associated with bone marrow and/or testicular involvement; however, it was recently reported that the number of extranodal sites is a more reliable predictor of CNS disease. Because primary mediastinal thymic large B-cell lymphoma (PMLCL) has a high propensity for involving extranodal sites, we investigated the frequency and pattern of CNS involvement in PMLCL. PATIENTS AND METHODS: The medical records of 219 patients with aggressive NHL, consecutively entered onto protocols at the National Cancer Institute between 1987 and 1998, were retrospectively reviewed. RESULTS: Twenty-three patients (11%) had clinical and pathologic features of PMLCL. These patients were young (median age, 29 years), female (61%), and presented with massive mediastinal adenopathy (70%). Extranodal disease occurred at presentation in 70% and at relapse in 93% of patients and involved contiguous intrathoracic structures and/or distant sites, including the lungs, kidneys, liver, adrenals, ovaries, pancreas, and bone. Six patients (26%) developed CNS involvement, two (9%) at presentation and four (27%) at relapse. All had extranodal disease, but only one had bone marrow involvement. Parenchymal and leptomeningeal CNS disease occurred in four and three patients, respectively. CONCLUSION: CNS involvement in PMLCL is associated with extranodal involvement other than bone marrow and may reflect the unique biology of this disease. The propensity to involve the CNS parenchyma raises the concern that intrathecal prophylaxis may not be effective and suggests that CNS imaging should be considered in patients with extranodal disease.

Smooth muscle tumors of the gastrointestinal tract. Flow cytometric quantitation of DNA and nuclear antigen content and correlation with histologic grade.

Simultaneous flow cytometric quantitation of DNA content and the proliferation-associated nuclear antigen p105 was performed on 41 gastrointestinal smooth muscle neoplasms and the results were correlated with histologic features. Aneuploid DNA stemlines were found in 17 cases (41%), including four of 15 (21%) tumors of unknown malignant potential, eight of 17 (47%) low-grade leiomyosarcomas, and five of seven (71%) high-grade leiomyosarcomas. In 10 of the 17 aneuploid tumors, an aneuploid peak was clearly identified on the single parameter DNA histogram, with a mean DNA index of 1.36. In the other seven aneuploid cases, a near-diploid, aneuploid population (mean DNA index, 1.08) was identified only by simultaneous immunofluorescence for p105. Clinical follow-up information was available for 14 patients. Mean survival of 10 patients with aneuploid tumors was 32 months, whereas mean survival of four patients with diploid tumors was 51 months. Of the seven patients who died within 1 year of diagnosis, six had aneuploid leiomyosarcomas. These findings demonstrate that DNA aneuploidy is common in high-grade gastrointestinal leiomyosarcomas and may be associated with shortened survival.

Immunophenotypic analysis of peripheral blood leukocytes at different stages of HIV infection. An analysis of asymptomatic, ARC, and AIDS populations.

Blood leukocytes from 51 patients with acquired immune deficiency syndrome (AIDS) or AIDS-related syndrome (ARC) were immunophenotyped with the use of monoclonal antibodies and flow cytometry. The patients were placed into four clinically defined groups: HIV-positive asymptomatic (HIV+/A, 8); persistent generalized adenopathy (14); Kaposi's sarcoma (12); and opportunistic infections (17). Immunophenotypes were compared between groups. Statistically significant differences were seen in absolute lymphocyte counts, total T-cells, helper/inducer T-cells, the helper inducer subset of CD4+ lymphocytes, the suppressor inducer subset of CD4+ lymphocytes, activated helper T-cells, and natural killer cells. CD8+ cells and subsets were not statistically different between groups, possibly obscured by large ranges, but median values suggested differences. Results indicate a pattern of increasing or decreasing numbers of certain subpopulations as HIV infection progresses.

Flow cytometric DNA and nuclear antigen content in astrocytic neoplasms.

Simultaneous flow cytometric DNA content and proliferation-associated nuclear antigen (p105) quantitation was performed on 23 astrocytic tumors and the results correlated with histologic subtype. Three of nine anaplastic astrocytomas and one of ten glioblastomas had an identifiable aneuploid peak, while all four well differentiated astrocytomas were diploid. Cell cycle analysis of malignant gliomas revealed a higher mean percentage of S and G2M cells compared to well differentiated astrocytomas but there was considerable overlap between histologic subtypes. Nuclear antigen analysis of diploid tumors showed a higher mean p105 fluorescence of S + G2M cells than G0G1 cells from the same case but there were no apparent differences in p105 expression by histologic subtype. Aneuploid tumors showed enhanced expression of p105 relative to diploid cells. The findings suggest that the aggressive course of high grade glial tumors may be related to an abnormal DNA stemline or an increase in proliferative activity.

Flow cytometric measurements of proliferation-associated nuclear antigen p105 and DNA content in non-Hodgkin's lymphomas.

Non-Hodgkin's lymphomas are characterized by heterogeneity in cell kinetics, which may be related to differential expression of proliferation-associated nuclear antigens. We have performed two-color flow cytometric quantitation of nuclear antigen p105 and DNA content in nuclear suspensions from 80 paraffin-embedded lymphomas. High-grade lymphomas with diploid DNA histograms tended to express high levels of p105 in all phases of the cell cycle. Aneuploid populations, observed in 14 of 80 cases, showed high p105 expression compared with diploid cells of the same case, with the highest aneuploid:diploid p105 ratios in the high-grade group. We conclude that high-grade or DNA aneuploid lymphomas tend to have increased expression of p105; but considerable variations within each histologic subtype were observed, and the differences between histologic grades were not statistically significant. Further studies that correlate p105 expression and clinical outcome will help to determine the prognostic value of this marker.

Factor structure of the WISC-R and ITPA for learning-disabled, emotionally disturbed, and control children.

There has been considerable interest in determining possible learning differences in specific populations of children. Stewart (1977) factor analyzed the WISC and ITPA for learning-disabled and mentally retarded samples and compared the results to a control group. He concluded that while the factors were quite similar, evidence suggested different learning processes in the groups studied. The present study (N = 301) enlarged and modified Stewart's study; it replaced the WISC with the WISC-R and the mentally retarded group with an emotionally disturbed sample. Three factors that emerged for all groups (linguistic, memory, and visual-motor) were similar to Stewart's findings. Additional factors highlighted motor skills and a separation in auditory and visual tasks for the learning-disabled group, an expressive factor for the emotionally disturbed, and a conceptual factor for the emotionally disturbed and control groups that was not found for the learning-disabled sample. Results suggested the need for individualized instruction.

Recurrent angioedema and urticaria.

The case reported here illustrates the life-threatening aspects of angioedema and the need to thoroughly investigate the possible causes of this clinical finding. As discussed, the causes of angioedema are numerous. Commonly implicated in drug-induced angioedema are antihypertensive ACE inhibitor drugs, as was originally thought with this patient. Because of her skin lesions and macrocytic anemia, further studies were done. These studies led to a diagnosis of hypocomplementemic urticarial vasculitis syndrome, an uncommon to rare form of acquired angioedema, urticarial vasculitis, arthritis, and obstructive airway disease associated with the production of autoantibodies to C1q. It is an autoimmune disorder related to but separate from SLE.

Immunophenotypes by flow cytometry: a longitudinal study in healthy individuals.

Weekly blood samples from five healthy volunteers were obtained for 13 weeks to assess the variations in the immunological phenotypes of peripheral blood lymphocytes and monocytes. Monoclonal antibodies to eleven lymphocyte and two monocyte antigens were evaluated using two-color flow cytometry. Average week-to-week differences were less than 5% for all monoclonal antibodies and combinations except for I2+, NKH-1+, MO1+, and MO2+ cells. The observed variations presumably reflected both technical variables and responses of the immune system to daily environmental insults.

Anti-CD4 monoclonal antibodies enhance phorbol 12-myristate, 13-acetate-induced activation of human T cells.

Evidence exists which indicates that the T cell differentiation molecule CD4 may interact with nonpolymorphic determinants of major histocompatibility complex (MHC) class II antigens on accessory cells to stabilize the formation of a ternary complex formed by the T cell receptor (CD3-TcR), antigen, and MHC class II restriction element. However, there is also evidence which suggests alternative or additional functional roles of CD4 in the delivery of signals to T cells independent of MHC class II recognition. In the present study, we examined different anti-CD4 monoclonal antibodies (mAbs) for their ability to influence lymphocyte proliferation induced by phorbol 12-myristate, 13-acetate (PMA). We found that the response of human peripheral blood mononuclear cells to PMA could be enhanced by some anti-CD4 mAbs (OKT4, OKT4A) but not by others (G17-2). This enhancement was due neither to a direct action of the mAbs on the monocytes nor to intercellular crosslinking through an Fc-Fc receptor interaction. We also found that the binding of anti-CD did not influence the down-regulation of CD4 expression induced by PMA, ruling out any correlation between increased stimulation and CD4 modulation. Our results, taken together with those recently published on the ability of a soluble anti-CD4 mAb (B66) to induce lymphocyte activation by itself, provide evidence that CD4 antigen plays a positive functional role in T cell stimulation in addition to stabilizing the antigen-antigen receptor interaction.

DNA flow cytometric analysis of mouse seminiferous epithelium.

In order to provide a basis for quantitative studies of murine spermatogenesis, we performed a DNA flow cytometric analysis on the mouse seminiferous tubules isolated at defined stages of the epithelial cycle by transillumination-assisted microdissection. Accurate stage identification was performed by examining spermatids in the adjacent tubule segments by phase-contrast microscopy. For flow cytometry, suspension of nuclei of spermatogenic cells was obtained by detergent treatment of isolated seminiferous tubules, and fresh samples were stained with propidium iodide. DNA histograms of the 12 stages of the mouse seminiferous epithelial cycle varied in a stage-specific manner. DNA histograms of stages I-VIII of the cycle were characterized by a hypofluorescent haploid peak, the location of which changed with the decreasing DNA dye (propidium iodide)-binding capacity of elongated spermatids. The absence of the hypohaploid peak and the high ratio of the cells with 4C amount of DNA to the cells with 1C amount of DNA characterized stages IX-XI of the cycle. Stage XII showed a high 2C peak, owing to a large population of secondary spermatocytes arisen from the first meiotic division. By using fluorescent beads as an internal volume standard cell numbers in defined stages were determined. These data provide a basis for quantitative studies of mouse spermatogenesis.

Lymphocyte mitogenesis and CD4 modulation induced by different phorbol esters: comparative studies.

Phorbol 12-myristate 13-acetate (PMA) can stimulate T-cells via its binding to protein kinase C (PKC). Such a phenomenon occurs when a threshold of concentration as low as 1 nM of PMA is reached. Other phorbol esters possess the ability to stimulate lymphocytes but at higher thresholds of concentration. We show here that the different phorbol ester concentrations needed to induce stimulation and proliferation, estimated by both interleukin-2 receptor (IL-2R) expression and DNA synthesis, correspond very closely to those inducing the modulation of CD4 antigen, confirming a direct relationship between CD4 down-regulation and cellular activation. We estimated the structural features of these different phorbol derivatives in relation to lymphocyte activation and CD4 modulation, and confirm that the ester side chains which give to the phorbol ester derivatives their lipophilic character, discriminate, according to their length, the ability of the different compounds to reach their receptor inside the cell membrane; we also brought some evidence that the polar phorbol nucleus of these compounds is probably responsible for their interaction with the membrane receptor mainly through the hydroxyl group in the C4 position.

Cytotoxic effects of cyclophosphamide in the mouse seminiferous epithelium: DNA flow cytometric and morphometric analysis.

Stage-specific cytotoxicity of cyclophosphamide (CP) in the mouse testis was analyzed by quantitative DNA flow cytometry and morphometry. In five series of experiments, three mice were injected (ip) with either a single dose of CP at 30 mg/kg or a vehicle saline. At 3, 11, and 20 days later, spermatogenic cells from stages II-V, VII-VIII, and IX-XI of the seminiferous epithelial cycle were quantified by flow cytometry and by morphometry. CP killed a part of the differentiating spermatogonia which became apparent at 11 days when the number of panchytene spermatocytes at stages II-V and VII-VIII was decreased. At stages IX-XI, the number of leptotene and zygotene spermatocytes declined at this time point. These damages could be detected by morphometry, while flow cytometry showed only the trend of the difference. At 20 days, both methods revealed a decrease in the number of haploid spermatids at stages VII-VIII (48 and 33% decrease detected by morphometry and flow cytometry, respectively). DNA flow cytometry proved to be a rapid and practical method to detect stage-specific disruption of spermatogenesis, while morphometry was more sensitive.

Peripheral blood mononuclear cell abnormalities and their relationship to clinical course in homosexual men with HIV infection.

Quantitative abnormalities of leukocyte subpopulations have been shown to correlate with clinical status in human immunodeficiency virus (HIV) infection. We have performed peripheral blood leukocyte phenotyping in 23 HIV-seropositive homosexual men, and correlated the results with clinical follow-up information. Individuals with CD4+ greater than 400/mm3 (Group 1) had less severe abnormalities in other mononuclear cell subpopulations than patients with CD4+ less than 400/mm3 (Group 2). Group 1 had decreased CD4+CDw29+ (B-cell inducer) cells, compared to HIV-seronegative homosexual controls, with normal CD4+CD45R+ (suppressor-inducer) cells, suggesting that CD4+ subpopulations are reduced at different rates. Group 2 had decreased counts for both CD4+CDw29+ and CD4+CD45R+ cells. Both groups had increased cytotoxic T cells (CD8+CD11b-), with decreased B cells and CD4+/CD8+ ratios, compared to HIV-seronegative homosexual controls. The Group 2 patients with subsequent clinical deterioration had particularly low CD4+ cells, CD4+CD45R+ cells, CD2+Ta1+ cells, and CD4+/CD8+ ratios and high CD8+CD11b- cells, compared to those with clinically stable illness. Our findings suggest that specific leukocyte subpopulations are altered differentially at various stages of HIV infection. However, the study involved only quantitative measurements of specific T- and B-cell subsets with no attempt to measure in vitro function. It is of course possible that normal numbers of cells in these subpopulations might be functionally deficient.

Flow cytometric analysis of pituitary tumors. Correlation of nuclear antigen p105 and DNA content with clinical behavior.

Flow cytometric quantitation of the proliferation-associated nuclear antigen p105 and DNA content was performed on nuclear suspensions from 12 paraffin-embedded pituitary macroadenomas and one pituitary carcinoma and correlated with clinical outcome. Median follow-up was 41 months (range, 33 to 48 months). Three of the 13 tumors (23%) had an identifiable aneuploid peak. Of the four tumors that recurred or metastasized, only one was aneuploid. Nuclear antigen analysis of all diploid tumors showed enhanced p105 expression in G2M phase cells compared to G0G1 cells. The G2M/G0G1 fluorescence ratio for p105 was consistently higher (P less than 0.05) for the three diploid tumors that recurred (median, 1.32 arbitrary fluorescence units; range, 1.27 to 1.80) than for the seven nonrecurrent diploid tumors (median, 1.20 arbitrary fluorescent units; range 1.14 to 1.22). These findings indicate a low incidence of DNA aneuploidy among pituitary tumors and suggest that for diploid adenomas, measurement of p105 may provide information useful in predicting prognosis and directing postoperative adjuvant therapy.

Flow cytometric quantification of rat spermatogenic cells after hypophysectomy and gonadotropin treatment.

DNA flow cytometry was evaluated as a tool to analyze stage-specific changes that occur in absolute cell numbers in the testes. Hypophysectomy was selected as a model system for perturbing testicular cell types, since the cytological sequelae of this treatment post-hypophysectomy in the rat are well documented in the literature. Rat spermatogenic cells in stages II-V, VII, and IX-XIII of the seminiferous epithelial cycle (as defined by Leblond and Clermont, 1952) were quantified in numbers per standard length of seminiferous tubule by DNA flow cytometry after hypophysectomy and subsequent gonadotropin treatment. In agreement with previous histological studies, we found that acrosome- and maturation-phase spermatids disappeared from the seminiferous epithelium after 17 days post-hypophysectomy, whereas meiosis and early spermiogenesis continued at least 164 days. The number of meiotic cells and round spermatids gradually decreased after hypophysectomy. Changes were observed as early as Day 6 post-hypophysectomy. Treatment with human chorionic gonadotropin (hCG) alone maintained most cell numbers within normal limits, and follicle-stimulating hormone (FSH) was needed in addition to hCG to maintain the normal number of cells with the amount of DNA contained in primary spermatocytes and spermatogonia in G2/M-phase (4C) in stages IX-XIII and elongated spermatids (1C') in stages II-V of the epithelial cycle. The absolute numbers of spermatogenic cells at different phases of maturation provide a useful reference for quantitative studies of spermatogenesis. Pathological changes in the seminiferous epithelium can be detected and quantified by DNA flow cytometry.