Research Laboratory Setting Research Articles

Detection of minimal residual disease in acute myelogenous leukemia.

Techniques to assay minimal residual disease are available for most patients with acute lymphoblastic leukemia, non-Hodgkin's lymphoma, breast cancer, Ewing's sarcoma, and others. Today, a few such tests exist for acute myelogenous leukemia (AML). This review evaluates the tests available for assessing minimal residual disease in AML: morphology, growth in vitro, cytogenetics, magnetic resonance imaging, polymerase chain reaction (PCR)-based assays for translocation products, and multiparameter flow cytometry. Of these, multiparameter flow cytometry appears most promising. Studies using multiparameter flow cytometry to identify leukemic cells by aberrant antigen expression have reported a high positive predictive value with regard to the incidence of relapse. In addition, the test is specific, rapid, inexpensive, and applicable to a sufficiently broad group of patients, allowing its use outside of the research laboratory setting. Judicious use of some of the available assays singly or in combination should identify patients harboring residual leukemic cells.

Autoantibodies in the diagnosis of systemicrheumatic diseases

Distinct profiles of autoantibodies directed to intracellular antigens can be detected in the systemic connective tissue diseases. They aid in establishing the correct diagnosis and are included in many sets of diagnostic criteria, such as the ones developed for systemic lupus erythematosus (anti-Smith antigen and anti-double-strand DNA antibodies), mixed connective tissue disease (anti-U1-nuclear ribonucleoprotein antibodies), and Sjögren's syndrome (SS) (anti-SS A/Ro and anti-SS-B/La antibodies). They are useful prognostic markers in some situations and facilitate clinical and treatment follow-up. Autoantibodies have also been used as probes to gain insights into cell biology, helping to isolate and purify intracellular proteins involved in key cellular functions. We give detailed information on two of the most useful techniques for the detection of autoantibodies in the clinical and research laboratory settings, indirect immunofluorescence and immunoblotting. We also discuss several of the antigen -autoantibody systems found in systemic lupus erythematosus (Smith antigen, U1-nuclear ribonucleoprotein, SS-A/Ro, SS-B/La, proliferating cell nuclear antigen ribosomal ribonucleoprotein, double-strand DNA, histones, antiphospholipids, Ku, Ki/SL), systemic sclerosis (centromere, topo I, RNA polymerases, fibrillarin, polymyositis-Scl, Th/To), polymyositis/dermatomyositis (transferRNA synthetases, signal recognition particle, and others), and SS (SS-A/Ro, SS-B/La, nucleolar organizing region-90, p80-coilin), addressing their clinical significance, common detection methods, immunogenetic associations, and the molecular and cellular biology of the cognate antigens.

Development of an automated closed system for generation of human lymphokine-activated killer (LAK) cells for use in adoptive immunotherapy

Immunotherapy utilizing the adoptive transfer of lymphokine-activated killer (LAK) cells in conjuction with recombinant interleukin-2 (IL-2) can mediate tumor regression in some patients with advanced cancer. The activation of large numbers of LAK cells was performed in roller bottles in a research laboratory setting and required meticulous aseptic technique, at least one skilled technician per patient and one laminar flow hood per patient. To reduce the complexity and expense of LAK cell generation for human immunotherapy trials we have developed a closed-system automated procedure using a continuous flow blood cell separator. PBL were obtained by standard apheresis techniques. Platelets and plasma were elutriated using countercentrifugal flow of saline in the cell separator machine. The washed PBL were underlaid with Ficoll-Hypaque (FH) in the original separation bag. Lymphocytes were then flushed into a collection bag where they were concentrated and washed with 2 liters of saline. Mean recovery from the automated FH technique was 54.6 ± 4.3% compared to 62.3 ± 4.0% using manual methods in 50 ml tubes ( P > 0.05). Cells were diluted in the collection bag with RPMI 1640 ± 2% human AB serum and could be dispensed in an automated fashion to polyolefin bags via a sample port with 1000–1500 U/ml IL-2. After 3–4 days of culture in 5% CO 2 at 37°C, activated cells from the bags were harvested and washed in a closed system using the continuous flow cell separator. Cell yield from the harvest was 79.2 ± 5.4% in the automated system compared to 64.9 ± 5.0% in the standard procedure using manual harvest of roller bottles ( P < 0.01). Lytic capacity of the cells against fresh human tumor in a 4 h 51Cr release assay was equivalent in cells processed either by the automated or the conventional manual method. The advantages of a closed system include decreased potential for microbial contamination and reduced labor and capital equipment costs. This technique may be easily adapted for use with other cell collection and culture systems.

Naturalistic Studies of the Long‐Term Effects of Television Violence

Carefully controlled experimental laboratory research has provided valuable evidence about the effects of media violence on the aggressive behavior of viewers in laboratory settings. However, social stimuli such as media violence can produce different effects in laboratory as compared to nonlaboratory settings. Thus, research in laboratory settings may not provide accurate information about the effects of media violence in nonlaboratory settings. Some types of quasi‐experimental field research can provide evidence about the long‐term socialization and developmental effects of media violence on viewer's behavior in naturalistic settings. The present article summarizes the findings from a number of quasi‐experimental studies about the effects of naturally occurring media violence. We conclude that the balance of the findings are consistent with the hypothesis that television produces a long‐term increase in the aggressive behavior of boys but not of girls.

Large scale production of human lymphokine activated killer cells for use in adoptive immunotherapy

Immunotherapy utilizing the adoptive transfer of lymphokine activated killer (LAK) cells in conjunction with recombinant interleukin 2 (RIL-2) is capable of reducing established metastatic cancer in a variety of animal tumor models. A major difficulty in the application of these efforts to the treatment of human cancer has been the activation in vitro of up to 2 × 10 11 human peripheral blood lymphocytes obtained by repeated leukaphereses. We have thus developed optimal and simplified techniques for the generation of human LAK cells for use in clinical trials. We have found that 1.5 × 10 9 lymphocytes separated on Ficoll-Hypaque gradients and incubated in 1000 ml of culture medium in a 2.3 liter roller bottle with 1000–1500 U of RIL-2 per ml, generated LAK cells capable of killing fresh human tumor cells in a 4 h chromium release assay. The culture medium used was RPMI 1640 with 2 mM glutamine, 2% heat-inactivated human AB serum, 50 μg/ml streptomycin and gentamicin and 50 U/ml penicillin. This technique allows activation of sufficient numbers of cells in a research laboratory setting to conduct human clinical trials. The administration of LAK cells generated in this fashion can mediate the regression of human tumors when administered in conjunction with IL-2.

Bilateral cannula system for intracranial chemical microinjection in small animals

An easily constructed and inexpensive bilateral cannula assembly for microinjection of chemicals into neural tissue in small animals is described. It reduces problems sometimes encountered with commercially available units, making it usefyl in both research and teaching laboratory settings. Suggestions for implant procedures and modifications for use in unique applications are suggested.