Adhesion of T lymphoblasts to epidermal keratinocytes is regulated by interferon gamma and is mediated by intercellular adhesion molecule 1 (ICAM-1).

The cell surface expression and function of the LFA-1 ligand, intercellular adhesion molecule 1 (ICAM-1), on epidermal keratinocytes (EK) was studied. ICAM-1 expression on the surface of cultured EK was either absent or weak, but was induced by treating EK with rIFN-gamma or TNF for 4-48 h. IFN-gamma and TNF were synergistic. IFN-gamma treatment increased T lymphoblast adhesion from less than 2% to 20-40%, with a concentration dependence similar to that seen for ICAM-1 induction. All of the adhesion to EK was inhibited by LFA-1 and ICAM-1 mAbs, but not by HLA-DR, CD2, or LFA-3 mAbs. There was no difference in the level of T lymphoblast adhesion to IFN-gamma-treated allogeneic or autologous EK. ICAM-1 purified from the HeLa epithelioid cell line and reconstituted into planar membranes also supported efficient adhesion of T lymphoblasts that was blocked by LFA-1 mAb bound to the T lymphoblasts or ICAM-1 mAb bound to the planar membranes. T lymphoblasts adherent to EK or ICAM-1 planar membranes were isolated by panning, and surface markers were analyzed by immunofluorescence flow cytometry. The adherent T cells were a phenotypically skewed subpopulation. They were enriched for CD8+ cells and expressed 1.5-2.5-fold higher LFA-1 and CD2 compared with the unseparated population.

Residential exposure to electric power transmission lines and risk of lymphoproliferative and myeloproliferative disorders: a case-control study.

BACKGROUND: Studies have shown an association between electromagnetic fields and childhood leukaemia. The aim of this study was to determine whether there is an increased risk of lymphoproliferative disorders (LPD) or myeloproliferative disorders (MPD) associated with residence < or =300 m from high-voltage power lines. METHODS: Case-control study of 854 patients diagnosed with LPD or MPD (including leukaemia, lymphoma and related conditions) aged 0-94 years comprising all cases diagnosed in Tasmania between 1972 and 1980. Controls were individually matched for sex and approximate age at the time of diagnosis. RESULTS: Compared with those who had always lived >300 m from a power line, those who had ever lived within 50 m had an odds ratio (OR) of 2.06 (95% confidence interval 0.87-4.91) for developing LPD or MPD (based on 768 adult case-control pairs); those who had lived between 50 and 300 m had an OR of 1.30 (0.88-1.91). Adults who had lived within 300 m of a power line during the first 15 years of life had a threefold increase in risk (OR 3.23; 1.26-8.29); those who had lived within the same distance aged 0-5 years had a fivefold increase in risk (OR 4.74; 0.98-22.9). These associations were strengthened when analyses were repeated for 201 pairs with entirely Tasmanian residential histories. CONCLUSION: Although recognizing that this study has limitations, the results raise the possibility that prolonged residence close to high-voltage power lines, especially early in life, may increase the risk of the development of MPD and LPD later.

Phase II trial with dose titration of paclitaxel for the therapy of human immunodeficiency virus-associated Kaposi's sarcoma.

PURPOSE: To investigate the antitumor activity and safety of paclitaxel in patients with advanced human immunodeficiency virus (HIV)-associated Kaposi's sarcoma (KS). PATIENTS AND METHODS: Twenty-nine patients with advanced HIV-associated KS were enrolled. The patients were overall quite immunosuppressed (median CD4 count, 15 cells/microL). Paclitaxel was initially administered at 135 mg/m2 over 3 hours every 3 weeks without filgrastim support; the dose was increased as tolerated to a maximum of 175 mg/m2. Patients who failed to respond or progressed could then receive filgrastim support or paclitaxel administered over 96 hours. RESULTS: Of 28 assessable patients, 20 had major responses (18 partial responses [PRs], one clinical complete response [CR], and one CR), for a major response rate of 71.4% (95% confidence interval [CI], 51.3% to 86.8%). Each of the five patients with pulmonary KS responded, as did all four assessable patients who had previously received anthracycline therapy for KS. Of six patients who went on to receive a 96-hour infusion of paclitaxel, five had major responses. Neutropenia was the most frequent dose-limiting toxicity; possible novel toxicities included late fevers, late rash, and eosinophilia. Two patients developed an elevated creatinine concentration and one cardiomyopathy. CONCLUSION: Paclitaxel has substantial activity against advanced HIV-associated KS as a single agent, even in patients with pulmonary involvement or who had previously received anthracyclines. Further research is needed to define the optimal treatment schedule and its role vis-a-vis the other available therapies for this disease.

Modulation of hematopoiesis by lymphocyte membrane-derived components.

Membrane bound erythroid burst-promoting activity (mBPA) is an integral membrane protein that is present on normal B-cells and some activated T-cells, that induces burst-forming units-erythroid (BFU-E) when cultured with human erythropoietin (rHuEpo). Plasma membranes and vesicles shed from the leukemic A-1 cell line express mBPA. This activity derived from both A-1 cells and normal B-cells can be immunoadsorbed by the D3A4 antibody raised against mBPA. In this study, we demonstrate that interferon-gamma (IFN-gamma) suppresses BFU-E proliferation when added directly to culture of normal human bone marrow cells and in the absence and presence of A-1 cells. However, FACS analysis reveals that IFN-gamma enhances the surface expression of mBPA on A-1 cells. The role of IFN-gamma in modulating erythropoiesis in vitro is discussed with respect to the role of shedding membrane-derived vesicles from the B-cell surface.

Expression of membrane-bound burst-promoting activity is mediated by allogeneic effector cells.

To investigate whether "self" and "non-self" recognition processes are involved in murine erythropoiesis, the expression of membrane-bound burst-promoting activity (mBPA) was determined for B lymphocytes purified from spleens of CF-1, C57 BL/6J, B6021-7115, and CAF-1J mice using syngeneic and allogeneic bone marrow cultures. Addition of B lymphocyte conditioned medium (LCM), shed membrane-derived vesicles, or intact plasma membranes prepared from syngeneic murine cells stimulated erythroid burst-forming unit (BFU-E) proliferation by two- to three-fold above control levels. BFU-E proliferation was increased by six- to eight-fold, however, when LCM, shed membrane vesicles, or plasma membranes purified from allogenic B lymphocytes were used as sources of growth-stimulatory activity. Bioactivity was immunoprecipitated from detergent extracts of membranes purified from both allogeneic and syngeneic lymphocytes with a monoclonal antibody that specifically recognizes mBPA, suggesting that the factors expressed by these cells share antigenic determinants. The results indicate that allogeneic effector cells are a more potent source of mBPA-like molecules than are syngeneic cells, suggesting that immune mechanisms may be involved in inducing erythroid growth factor expression at the B cell surface.

Epidermal keratinocytes express the adhesion molecule intercellular adhesion molecule-1 in inflammatory dermatoses.

Using indirect immunofluorescence assays on frozen tissue sections of skin from healthy subjects and subjects with inflammatory skin diseases, we found that intercellular adhesion molecule-1 (ICAM-1) was expressed in a cell surface pattern on epidermal keratinocytes at the site of lymphoid infiltration in cutaneous dermatoses. ICAM-1 was not expressed on epidermal keratinocytes in noninflamed skin. Its expression was not related solely to epidermal hyperproliferation, as hyperproliferative, tape-stripped epidermis did not express ICAM-1. We have reported previously that ICAM-1 expression on epidermal keratinocytes was upregulated by treatment with interferon gamma and that activated T lymphocytes bound to cultured epidermal keratinocytes in vitro by lymphocyte function associated-1 (LFA-1) molecules on T cells and ICAM-1 on epidermal keratinocytes. Taken together, these data suggest that upregulation of expression of ICAM-1 is an important feature of cutaneous inflammation.

Removal of fibroblasts from human epithelial cell cultures with use of a complement fixing monoclonal antibody reactive with human fibroblasts and monocytes/macrophages.

A complement fixing IgM monoclonal antibody (1B10) that reacts with surface membrane molecules of human fibroblasts, tissue macrophages, and peripheral monocytes was produced. In Western blot analysis of detergent extracts of cultured human foreskin fibroblasts, antibody 1B10 detected protein bands of Mr 43,000 and 72-80,000. We used the 1B10 antibody with complement to eliminate most 1B10 positive nonepithelial cells from thymic epithelial (TE) cell cultures, thereby allowing us to grow highly enriched populations of human TE cells.

Association between high interleukin-6 levels and adverse outcome after autologous haemopoietic stem cell transplantation.

We studied interleukin-6 (IL-6) levels on the day of transplantation in 31 patients undergoing autologous haemopoietic stem cell transplantation (SCT) (either peripheral blood stem cell transplantation (PBSCT) or bone marrow transplantation (BMT)) for neoplastic diseases to determine if there was a relationship between IL-6 level and rate of haemopoietic recovery, length of stay in hospital, and survival. There was no apparent delay in post-transplant recovery associated with elevated IL-6 levels. However, increased values of IL-6 tended to be associated with an increased length of stay in hospital (P = 0.083). There was a highly significant adverse association between higher IL-6 levels and survival following transplantation (P = 0.0001). This association remained significant (P = 0.013) in the uniform subgroup of patients with malignant lymphoma with chemosensitive disease who had undergone BMT (that is, excluding patients who had undergone PBSCT) (n = 13). Knowledge of IL-6 levels on the day of transplant has the potential to provide valuable prognostic information in patients undergoing autologous haemopoietic SCT.

Magnetic field dependence of spin-lattice relaxation enhancement using piperidinyl nitroxyl spin-labels.

We examined the magnetic resonance properties of 12 paramagnetic piperidinyl nitroxyls in water and plasma solutions. Paramagnetic contributions to proton relaxation times were measured using 10.7 and 100 MHz spectrometers. Proton relaxation enhancement from nitroxyls increased with ascending molecular weight, in plasma solutions versus equimolar aqueous solutions, and with measurements at 10.7 MHz compared to 100 MHz. Relaxation rates were observed to approximately double at 10.7 MHz compared to 100 MHz and from water to plasma solutions. The data indicate that proton spin-lattice relaxation enhancement is magnetic field-dependent, and increases using nitroxyls of large molecular weight and with chemical substitutents that increase the microviscosity of solvent water molecules. The development of nitroxyls for diagnostic MRI will be aided by understanding these in vitro physical characteristics and trends.

Factors affecting recovery after peripheral blood stem cell transplantation.

To determine the factors that might be involved in successful engraftment following administration of autologous peripheral blood stem cells (PBSC) obtained by leukapheresis to replace bone marrow after ablation therapy for malignant disease, four patients were examined in detail. One who had had pelvic radiation as well as chemotherapy had a prolonged, gradual but complete recovery. One who received granulocyte-macrophage-colony stimulating factor (GM-CSF) following PBSC infusion showed a rapid recovery phase, but developed high fever (culture negative) associated with arrested hematopoiesis and died with central nervous system (CNS) symptoms after 120 days. Two other patients recovered without major incident. Concentration of PBSC was analyzed by: (1) approximation by counting mononuclear cells (MNC); (2) CD34 cells by flow cytometric analysis; and (3) colony forming units-granulocyte macrophage (CFU-GM) by colony formation in microtiter plates. The time to BM recovery (retics > 1.0 percent, neutrophils > 500 per cumm, platelets > 50,000 per cumm) was determined by following daily counts. Engraftment appeared to depend upon an adequate minimum dose of PBSC, but ultimate recovery of the patient seemed to be determined by ancillary factors, especially CNS infection. These patients illustrate that while rapidity of bone marrow (BM) recovery may be related to PBSC dose, other factors, particularly infection, influence patient outcome.

A system for automated procedure documentation.

Quantitative information regarding competency in performing procedures is invaluable in attesting to a house officer's abilities when assessments need to be made. Thus, the means by which procedures, proficiency, and experience can be recorded and organized in an automated fashion need not be any further away than the nearest micro-computer. The procedure documenting system (PDS) automates the documenting of procedures and quantitative information pertaining to these procedures, and shortens the time demanded of the house officer to document procedures from a mean of 5.5 to 1.9 min. This paper is a description of the work done to automate the recording of procedures performed by housestaff at a teaching hospital and the acceptance by housestaff. This computer program takes the specific information and places it into a specialized database so that house officers can have detailed documentation attesting to their proficiency in various procedures. In addition, the program director can access the database to document the quantity of procedures to which an individual house officer has attained competence.

Ultrasonic equipment for the measurement of backfat on unshorn live sheep.

Because of the ease of application to the animal's exposed skin, the measurement by A-scan ultrasonics of backfat on pigs is an established technique; but difficulties are experienced with unshorn sheep because the fleece presents an obstacle, as a parting of the wool offers only a limited aperture for insonification of the subcutaneous tissues. Also, movement of the typical nervous sheep usually provides somewhat intermittent return echo signals, rendering difficult an otherwise simple measurement. The present instrument has overcome these problems by an accumulator-averaging technique, implemented by a microprocessor, allowing estimation of live backfat thickness to the nearest 0.5 mm. This paper describes the instrument function, and presents results of a series of experiments which examined the correlation with the carcass backfat thickness.

HDAC inhibitors induce transcriptional repression of high copy number genes in breast cancer through elongation blockade.

Treatment with histone deacetylase inhibitors (HDACI) results in potent cytotoxicity of a variety of cancer cell types, and these drugs are used clinically to treat hematological tumors. They are known to repress the transcription of ERBB2 and many other oncogenes, but little is known about this mechanism. Using global run-on sequencing (GRO-seq) to measure nascent transcription, we find that HDACI cause transcriptional repression by blocking RNA polymerase II elongation. Our data show that HDACI preferentially repress the transcription of highly expressed genes as well as high copy number genes in HER2+ breast cancer genomes. In contrast, genes that are activated by HDACI are moderately expressed. We analyzed gene copy number in combination with microarray and GRO-seq analysis of expression level, in normal and breast cancer cells to show that high copy number genes are more likely to be repressed by HDACI than non-amplified genes. The inhibition of transcription of amplified oncogenes, which promote survival and proliferation of cancer cells, might explain the cancer-specific lethality of HDACI, and may represent a general therapeutic strategy for cancer.