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S A Goodman

Publications and source records attributed to S A Goodman.

29 records · Page 2Linked to original sources
PubMed1984

Selective association of lipid-rich R-like lipopolysaccharide subunits with murine spleen cells.

SDS-PAGE was used to analyze the subunit composition of 125I-lipopolysaccharide (LPS) in the cell-associated and supernatant fractions of murine spleen cells after culture with radiolabeled LPS from the smooth strain of E. coli O55:B5. Quantitative estimates from densitometric scans of autoradiographs indicated that certain R-like subunits were selectively enriched in cell-associated fractions by a factor of 2.8 as compared to native O55 LPS. Coincident with this selective enrichment was a 57% decrease in these subunits in supernatant fractions. In contrast, the level of polysaccharide-containing subunits in cell-associated fractions was equivalent to or less than the corresponding subunit in native LPS. LPS bound at 37 degrees C was capable of eliciting a significant B-lymphocyte proliferative response in responder spleen cells. However, this selective binding of lipid-rich R-like subunits to splenocytes is insufficient, by itself, to initiate a triggering event since it is both quantitatively and qualititatively indistinguishable in lymphoid cells from the LPS responder (C3HeB/FeJ) mouse and the LPS non-responder (C3H/HeJ) mouse.

Animals↗
PubMed1981

Immunological identification of lactoferrin as a shared antigen on radioiodinated human sperm surface and in radioiodinated human seminal plasma.

After lactoperoxidase-catalyzed iodination of either human sperm surface or human seminal plasma, a 72-76 kdalton component was resolved on SDS-7.5% polyacrylamide gels. The approximate molecular weight of this component was consistent with that of human lactoferrin, a major sperm-coating antigen. Immunoprecipitation of labeled sperm surface and of labeled seminal plasma with specific anti-human lactoferrin antibody identified lactoferrin as a constituent of this 72-76 kdalton component both on human sperm surface and in human seminal plasma. These data show that components which have been inferred to be shared because of similarities in biochemical characteristics also contain immunologically identical components.

Absorption↗
PubMed1975

Cell surface immunoglobulin. XIII. Distribution of IgM and IgD-like molecules on small and large cells of mouse spleen.

The distribution among murine spleen cells of a newly described class of surface immunoglobulin (Ig) with properties similar to human IgD was studied. Splenocytes were separated on the basis of size and the surface Ig on large cells (sedimenting faster than 6 mm/hr in a 1 times G velocity gradient) and small cells (sedimenting between 2.5 and 3.0 mm/hr) was analyzed. Spleen cells from young animals had virtually only IgM on the large cells but had substantial amounts of IgM and the IgD-like molecule (IgD) on small cells. Spleen cells from older animals, which have larger amounts of IgD, had IgM and IgD on both cell types; however, the amount of IgD relative to IgM on the large cells was always substantially less than that on the small ones. These observations taken together with those of other investigators support the hypothesis that a large lymphocyte with surface IgM is the precursor of a small lymphocyte with both surface IgM and IgD.

Animals↗
PubMed1975

Effect of age on cell-mediated immunity in long-lived mice.

The cytolytic ability of sensitized spleen cells to kill allogeneic target cells in vitro, a correlate of cell-mediated immune activity, was assessed in aging long-lived hybrid mice. There was about a 4-fold decline with age, of which about 2-fold could be accounted for by the decrease in relative numbers of immunocompetent precursor cell units. The terminally differentiated progeny cells of antigen-stimulated precursor cells of old mice were as efficient in killing target cells as were those of precursor cells of young mice. Thus, it would appear that a decrease in the proliferative and transforming capacities of antigen-stimulated precursor cells of old mice can account for the other 2-fold decline with age in the cytolytic activity. Cytolytic activity may not be the limiting function in resistance to tumour formation. This was indicated by the observation that resistance to allogeneic tumor cell challenge declines with age by as much as 500-fold in mice, showing only a 4-fold decline in their cytolytic activity.

Aging↗
PubMedDate not supplied

The late effects of selected immunosuppressants on immunocompetence, disease incidence, and mean life-span. II. Cell-mediated immune activity.

The late effects of various immunosuppressive insults on cell-mediated immunity in mice were studied in an attempt to assess the role of immune surveillance in the aging process. Results were obtained using susceptibility to allogeneic tumor cell challenge, graft-versus-host reaction (GVHR), blastogenic response to PHA, a thymus derived T cell-specific plant mitogen, and cytolytic activity against allogeneic tumor cells as measures of immunologic activity. In vivo studies late in life show that resistance to allogeneic tumor cells is significantly decreased in thymectomized mice, whereas those treated with cortisone, cyclophosphamide and sublethal X-ray remain unchanged. Spleen cells from only the thymectomized and the sublethally irradiated mice show reduced activity in the GVHR. No difference is seen in the activity of bone marrow cells. Results consistent with these findings were obtained in in vitro studies. Thus spleen cells from thymectomized or sublethally irradiated mice show decreased activity is response to PHA, whereas no change is seen in spleen cells from other treated groups. Hence, surgical and physical insults are more likely to induce long-lasting immunosuppression in those immunocompetent tissues whose activity normally diminishes with advancing age. Furthermore, the degree of immunosuppression seen in this study is not of the order of magnitude that one could reasonably predict a significant decrease in mean life-span.

Age Factors↗
PubMedDate not supplied

Selective interaction between lymphocytes and lipid A subunits in lipopolysaccharide macromolecular aggregates.

The interaction between bacterial lipopolysaccharides (LPS) and murine spleen cells was examined. The results indicate that lipid A-rich subunits, contained within the heterogeneous LPS macromolecule, associated selectively with spleen cells. In the LPS not associated with spleen cells, the relative amounts of lipid A-rich subunits were reduced; however, this reduction was not of a sufficient magnitude to be reflected in the stimulation of B cells. By constructing hybrid LPS macromolecules with various amounts of lipid A-rich subunits it was documented that mitogenic activity of B cells was relatively refractory to lipid A subunit composition. Furthermore, the presence of polysaccharide-rich subunits regulated downward the expression of lipid A-dependent activity.

Animals↗
PubMedDate not supplied

Determination of normal values using an automated coagulation timer for activated coagulation time and its application in dogs with hemophilia.

The present study was performed to determine normal values for the Medtronic HemoTec automated activated coagulation time (ACT) analyzer (Medtronic HemoTec Inc, Parker, CO, distributed in Switzerland by Convergenza AG, Vaduz, Liechtenstein), and to evaluate its ability to detect dogs with hemophilia. ACT was measured in 43 healthy dogs presented to the Companion Animal Hospital, University of Bern, Bern, Switzerland, with the Medtronic HemoTec ACT analyzer to determine normal values. The mean +/- 2 standard deviations (SDs) of the values obtained was defined as the normal range. ACT was measured 8-10 times on the same day in 6 dogs to determine repeatability. ACT also was measured in 11 dogs with hemophilia and compared with a conventional visual ACT measurement test and with the activated partial thromboplastin time (APTT). ACT values of the 43 dogs used to determine normal values ranged from 66.5 to 97.0 seconds (mean, 79.3 seconds; SD, 7.35 seconds; median, 78.5 seconds). A range of 64-95 seconds (mean +/- 2 SDs) was defined as the normal range for the tested device. Repeatability was poor (r = 0.256). ACT values measured with the automated device did not correlate with ACT values measured with a conventional visual test or with APTT Sensitivity of the test was 90.9%, specificity was 98.0%, and accuracy was 96.7%. Variability in the test results was large and may lead to incorrect results. The automated measurement device was not superior to the conventional visual method in evaluating dogs with hemophilia.

Animals↗