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Biomedical subjects

S Plaeger-Marshall

Publications and source records attributed to S Plaeger-Marshall.

25 records · Page 2Linked to original sources
PubMed1987

Alterations in cytotoxic and phenotypic subsets of natural killer cells in acquired immune deficiency syndrome (AIDS).

Testing of cytotoxic function using a panel of natural killer (NK)-sensitive target cells, including a unique herpes simplex virus-infected Raji-cell target, was performed in conjunction with phenotypic cell analysis by dual-color flow cytometry to characterize the NK system. Subjects included in the study were at risk for or infected with the etiologic agent of the acquired immune deficiency syndrome (AIDS), human immunodeficiency virus (HIV). A generalized defect in NK function was temporally correlated with disease manifestations, as evidenced by deficient NK lytic function in patients with AIDS and AIDS-related complex (ARC). Healthy at-risk subjects, including those seropositive for HIV, exhibited robust NK-cell function. Phenotypic analysis revealed that normal proportions of the NK-associated CD16+ (Leu11) Leu7- and CD16+(Leu11)Leu7+ lymphocyte subsets were maintained throughout the clinical progression of HIV infection. However, the proportion and numbers of cells of the CD8+(Leu2)Leu7+ subset were increased in AIDS, ARC, and healthy at-risk subjects, including those seronegative for HIV. These results are consistent with a qualitative defect in the NK system in AIDS, perhaps secondary to CD4-cell depletion and a concomitant lack of essential accessory factors. The elevation in CD8+(Leu2)/Leu7+ cells is not solely the result of HIV infection and may be a general response to viruses and/or other antigenic stimulation.

AIDS-Related Complex↗
PubMed1986

A statistical method for assessing change in immunologic parameters in a patient.

Serial measurement of in vitro immunologic parameters in patients is used to detect change in immune status over time due to disease progression and/or immunodulatory therapy. A statistical method is presented for looking at serial measurements on an individual to detect whether a change in a parameter is outside the bounds of expected within-individual variation. Analysis of variance is used, assuming a normal distribution, to obtain percentiles of the distribution of the absolute difference between consecutive values of immunologic parameters in a healthy population. The assumptions in this analysis are justified from a statistical point of view. We discuss how to use this statistical method to make judgments relevant to clinical immunology, including how to construct a table that can be used to determine quickly if an "interesting" change for some standard immunologic parameters has occurred, whether a linear (additive) or logarithmic (proportional) model for change might be more appropriate for a given parameter, and how to modify the calculations if change is expected in a certain direction or if multiple pre- and/or postevent (clinical change or intervention) measurements are available.

Adult↗
PubMed1985

Influence of racial background on the distribution of T-cell subsets and Leu 11-positive lymphocytes in healthy blood donors.

As part of a study to define the factors affecting the distribution of lymphocyte subpopulations in healthy blood donors, we have measured lymphocyte surface markers in various racial groups. Markers tested were T3 (all T cells), T4A (T helper cells), T8 (T suppressor cells), and Leu 11 (natural killer cells). Racial groups included three Asian groups (Chinese, Japanese, Other Orientals) and three non-Asian groups (Caucasians, Hispanics, American Blacks). The mean percentage of T3 + cells and T4A + cells were significantly lower in Asians compared with non-Asians, while T8 levels did not differ. These changes resulted in a significantly lower mean T4A:T8 ratio in Asians compared with non-Asians. The mean percentage of Leu 11 + cells was higher in Asians compared with non-Asians. Within the Asian group, Chinese had a higher mean Leu 11 + value than the other two Asian groups combined. Further, pairwise comparisons showed that Chinese had a significantly higher mean Leu 11 + value compared with each of the other five racial groups. This increased mean Leu 11 + level in the Chinese group reflected a distinct cluster of high values for about half the subjects. These findings show that racial background should be a major consideration when defining the normal range for lymphocyte subpopulations detected by surface markers.

Adult↗
PubMed1983

Alteration of rabbit alveolar and peritoneal macrophage function by herpes simplex virus.

Exposure of rabbit alveolar and peritoneal macrophages to infectious herpes simplex virus resulted in inhibition of antibody-dependent cellular cytotoxicity and either enhancement or inhibition of phagocytosis. At all times after exposure, virus was inhibitory to peritoneal macrophage phagocytosis. Alveolar macrophages showed enhanced phagocytic activity in the early stages of virus exposure and inhibition at later time points.

Animals↗
PubMed1982

Permissiveness of rabbit monocytes and macrophages for herpes simplex virus type 1.

The permissiveness of rabbit monocytes and macrophages for herpes simplex virus was examined. Peripheral blood monocytes, alveolar macrophages, and peritoneal exudate macrophages were studied for their ability to replicate herpes simplex virus strains RE and KOS. Results indicated different degrees of interaction with virus depending on the macrophage type. Only peritoneal exudate macrophages showed evidence of virus replication. Productive infection was limited, with only a small number of cells (0.02%) yielding infectious virus. Higher numbers of cells appeared to be abortively infected. Approximately 40% expressed antigens, whereas virtually all were killed by exposure to virus. Coreless particles were seen by electron microscopy in about one-third. Alveolar macrophages were also killed by virus and showed evidence of virus adsorption, but showed no indication of productive or abortive infection. Monocytes neither adsorbed nor replicated virus, and viability was unaffected. Results suggest that differences in degrees of cellular maturation or differentiation, or both, account for the spectrum of interactions seen between herpes simplex virus and rabbit macrophages.

Adsorption↗
PubMed1978

Inhibition of mitogen- and antigen-induced lymphocyte blastogenesis by herpes simplex virus.

Lymphocytes were separated from peripheral blood of adult human donors by Ficoll-Hypaque gradient centrifugation and cultured in the presence of nonspecific mitogens (phytohemagglutinin[PHA] and concanavalin A) or specific microbial anatigens (herpes simplex virus [HSV], mumps virus, streptococcal enzymes, and Candida albicans). Exposure of lymphocyte cultures to infectious HSV resulted in almost complete inhibition of blastogenesis ([3/H]thymidine uptake) induced by each of the mitogens and antigens, a finding which suggests that a common mechanism may underlie the inhibitory effect. Several characteristics of the effect of virus on blastogenesis were noted: (1) virus inactivated by heat or ultraviolet irradiation was ineffective; (2) inhibition (is greater than 90%) was greatest in cultures exposed to HSV on or before the addition of PHA; (3) lymphocyte preparations washed free of HSV continued to be refractory to stimulation, an observation indicating that the presence of unabsorbed virions or viral products was not essential; and (4) inhibition was independent of the cell donor's state of humoral immunity to HSV.

Antibody Specificity↗