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M F La Via

Publications and source records attributed to M F La Via.

15 recordsLinked to original sources
PubMed1992

Clinical applications of cytometry: 6th annual meeting.

The Sixth Annual Clinical Applications of Cytometry Meeting was held September 11-14, 1991, in Charleston, SC. Attendance reached a record 470. The meeting provides a forum for interactions among investigators who utilize cytometry as a tool in their clinical immunology, cell biology, hematology, and cancer investigations. Clinical laboratory directors and their technical staff find the meeting of practical value because of the presentation of new applications that they can take home to their own laboratories. The emphasis of the meeting is on advances in the application of cytometry to clinical problems. Often, advances result from new dyes or reagents or improved instrumentation. Sometimes they result from advances in biology that make the studies possible. Occasionally a new way of looking at the same data provides a useful answer. In every case, the effort is to provide a reliable, straightforward way to quantitate biologic information in order to provide improved diagnosis or treatment of human disease.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Clinical applications of cytometry: 5th annual meeting.

The 5th annual Clinical Applications of Cytometry meeting was held September 12-15, 1990 in charleston, SC. The theme which emerged repeatedly throughout the meeting was the need to take full advantage of the quantitative power of cytometry to provide the most useful clinically relevant diagnostic and prognostic information. Greater quantitative power is based on careful and reproducible standards and quality control. The same principles, albeit with somewhat different approaches, apply to cell surface immunofluorescence analysis, DNA measurements, and image cytometry assessments. Monoclonal antibody probes against oncogenes, others against lymphokines within the Golgi, and a novel fluorogenic substrate designed to quantitate the activity of a mitochondrial enzyme were exciting developments described at the meeting.

Autoimmune Diseases↗
PubMed1991

Psychoneuroimmunology: where are we, where are we going?

We have reviewed briefly the current status of research on central nervous system-immune system interactions, focusing attention on the neural and humoral pathways by which CNS and IS communicate and interact and on the effects of stress and psychiatric illness on immune function. It is evident that CNS-IS communication occurs by direct innervation of lymphoid organs and by means of hormones, neuropeptides and cytokines. There is also clear evidence that humoral substances each of which were thought to be the product of one specific cell type are elaborated and secreted by a variety of cell types. This observation suggests a new unified concept of CNS-IS interactions with mediators of these interactions being produced ubiquitously and acting on cells of the two systems. In examining the effects of stress on IS it has become apparent that stress of various types can have a depressive effect on immune functions, primarily at the level of T lymphocytes and NK cells. This suggests that the defense mechanisms affected by stress are those which are responsible for cytotoxic effector responses. These findings are interesting in that they support older studies implicating stress in the pathogenesis and/or the clinical course of neoplastic diseases. Further support for a role of stress-induced immunodepression in morbidity comes from a very interesting, recent prospective study showing that stress will affect susceptibility to viruses. Finally, exploration of the mechanisms of stress-induced immunodepression, suggests that a variety of mediators which regulate lymphocyte interactions and activation may be affected, perhaps at the level of gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗
PubMed1990

Immunophenotypic analysis of non-Hodgkin's lymphomas.

Flow cytometric cell analysis with fluorescence-labeled antibodies has become a very useful methodology for the immune phenotyping of lymphocytes. The continued evaluation of lymphocyte cell surface antigens has been of value in this respect by providing a clear picture of lymphocyte differentiation steps. Thus it is now possible to precisely identify lymphocytes of abnormal phenotype which may represent malignant cells. Detection of monotypic populations of lymphocytes represents a monoclonal expansion of a lymphocyte subset which is the hallmark of malignancy. In the case of B cell lymphoma, detection of monotypic populations rests on the finding of a monoclonal expansion of a cell type bearing one type of light chain and of heavy chain and/or one of the specific B lymphocyte differentiation antigens. The diagnosis of T cell malignancy is more difficult to establish and a diagnosis of T cell lymphoma rests on the finding of an abnormal phenotype. Thus flow cytometry in combination with histomorphologic examination is a useful technique for the more precise diagnosis of lymphomas and for the establishment of treatment protocols.

Antibodies, Monoclonal↗
PubMed1979

Phenol derivatives are immunodepressive in mice.

Mice exposed to a compound containing three phenol derivatives by being housed in cages washed with dilute solutions of the compound, developed considerable depression of the ability to generate plaque forming cells (PFC) in response to sheep erythrocytes (SRBC) in vitro after a four week exposure. The depression became more severe with continued exposure up to fourteen weeks. Administration of orthophenylphenol (OPP), the most abundant derivative in the mixture, resulted in a similar immunodepression at 10 ppm and a slight depression at 1 ppm. Numbers of FcR+ lymphocytes and of macrophages did not appear to be affected by this treatment. The response to a T-dependent and a T-independent antigen were affected similarly, although the latter was depressed less markedly than the former. While these data are only preliminary, they suggest that studies should be performed in detail to elucidate the immunodepressive effects of compounds which are in wide use as household and institutional disinfectants.

Animals↗
PubMed1976

Inhibition of antigen-induced B lymphocyte activation in vitro by cytochalasin B.

Cytochalasin B (CB), a fungal metabolite which disrupts microfilaments. and will inhibit capping and other events requiring membrane movement, suppressed the production of antibody-forming cells (AFC) in both mouse whole spleen cultures immunized with sheep erythrocytes (SRBC) and in mouse B lymphocyte cultures immunized with the thymic independent antigen DNP-Ficoll (DF). CB at a concentration of 1 mug/ml inhibited the AFC response by more than 90% in spleen cell cultures immunized with SRBC. This inhibition was completely reversible by removal of CB up to 24 hr after the start of culture. Spleen cells cultured in the presence of CB for the first 48 to 72 hr had a decreased AFC response similar to that of cultures in which SRBC had been withheld for thocyte the same period of time. Incubating whole spleen cell or B lymphocyte cultures immunized with DF for as short as 6 hr decreased the AFC response more than 60%. Antibody secretion, cell viability, and antigenicity of the SRBC and DF were not affected by CB. The results of these experiments favor the concept that movement of surface receptors is necessary in activating lymphocytes to differentiate into AFC. The differential response to CB observed in SRBC and DF stimulated cultures makes the technique employed a useful tool to study membrane events occuring between antigen interaction with surface receptor and the initiation of differentiative events.

Animals↗
PubMed1975

Biochemical and morphological changes in hepatic nuclear membranes produced by N-hydroxy-2-acetylaminofluorene.

The effect of N-hydroxy-2-acetylaminofluorene on the ultrastructure and synthesis of hepatic neclear membranes was evaluated in partially hepatectomized rats. The incorporation of L-[4,5-3H]leucine into two nuclear membrane fractions increased within 2 hr after hepatic resection and reached a peak at 20 hr. After partial hepatectomy, the decay of radioactivity in nuclear membrane proteins labeled with L-[4,5-3H]leucine revealed similar half-lives for the two membrane fractions when compared to those obtained from sham-operated animals. The protein concentration of the nuclear membrane fraction of higher density decreased sharply within 2 hr after partial hepatectomy and remained low throughout a 20-hr postoperative period. Polyacrylamide gel electrophoresis of both nuclear membrane fractions showed a similar composition. Nine proteins were resolved, varying from 21,000 to 190,000 daltons. The two major protein bands were in the range of 50,000 and 70,000 daltons, respectively. Treatment of partially hepatectomized animals with N-hydroxy-2-acetylaminofluorene showed marked dilation of the nuclear envelope and rough endoplasmic reticulum in situ upon electron microscopic examination. Vacuolization and evagination of the perinuclear membranes were also noticeable in isolated nuclei obtained from carcinogen-treated rats. Inhibition by N-hydroxy-2-acetylaminofluorene of the incorporation of L-[4,5-3H]leucine into the nuclear membranes was dose-dependent and remained depressed throughout a 60-min labeling period. These results suggest that the inhibitory effects on RNA and protein synthesis previously shown to be produced by this arylhydroxylamine hepatocarcinogen may lead to disruption of the morphology and synthesis of the nuclear envelope.

Animals↗
PubMedDate not supplied

Significance of common acute lymphoblastic leukemia antigen (cALLA) positive cells in bone marrow of children off therapy in complete remission.

Bone marrows from 21 children with acute lymphoblastic leukemia in complete remission (CR) and off therapy for 14 months to 10 years were examined by flow cytometry with a panel of monoclonal antibodies. Significant percentages of cALLA+ cells of low fluorescence intensity were present up to 9 years after CR. These results emphasize the need to interpret flow cytometry results in light of the findings that low intensity cALLA+ cells represent a normal population of immature, non-malignant lymphoid cells.

Antigens, Differentiation↗