Biomedical subjects

Margaret Olsen

Publications and source records attributed to Margaret Olsen.

9 recordsLinked to original sources

PubMed2006

New enzyme-linked chemiluminescent immunosorbent digoxin assay is free from interference of Chinese medicine DanShen.

DanShen is a traditional Chinese medicine indicated for cardiovascular diseases. The potential interference of DanShen with serum digoxin measurement was investigated using a new enzyme-linked chemiluminescent immunosorbent (ECLIA) digoxin assay. Aliquots of drug-free serum were supplemented with ethyl acetate extract of DanShen (4 different brands studied), and apparent digoxin concentrations were measured by the ECLIA as well as fluorescence polarization immunoassay (FPIA) and a turbidimetric assay for comparison. Mice were also fed 4 DanShen preparations and apparent digoxin concentrations were subsequently measured. In another experiment, serum pools containing digoxin were further supplemented with DanShen extracts and digoxin concentrations were measured again by all 3 assays. No apparent digoxin concentration was observed when aliquots of drug-free serum pools were supplemented with DanShen and digoxin concentrations were measured by the ECLIA or the turbidimetric assay. In contrast, significant apparent digoxin concentrations were observed using FPIA, and the highest apparent digoxin concentration was observed with brand 4 of DanShen extract. Similarly, when mice were fed with this herb, significant apparent digoxin concentrations were also observed using FPIA, but neither ECLIA nor turbidimetric assay showed any apparent digoxin concentration. When aliquots of digoxin pool were further supplemented with various DanShen extract, the apparent digoxin concentrations were significantly increased when FPIA was used. In contrast, digoxin concentrations in the presence of DanShen extract compared well with the digoxin concentration of the original pool when ECLIA or turbidimetric assay was used. We conclude that DanShen does not interfere with serum digoxin measurement using a more recently released ECLIA digoxin assay.

Animals↗

PubMed2006

Trehalose 6,6'-dimycolate and lipid in the pathogenesis of caseating granulomas of tuberculosis in mice.

Trehalose 6,6'-dimycolate (TDM) is the most abundant, most granulomagenic, and most toxic lipid extractable from the surface of virulent Mycobacterium tuberculosis (MTB). We further examined its toxicity, which requires activation by oily surfaces. Injections of MTB and/or TDM into sensitized mice induced caseating granulomas that centered on oil droplets. If large doses of MTB were injected in saline, caseating granulomas developed in adipose tissue, but MTB with surface TDM removed induced only acute inflammation that did not persist. Variations in protocols produced several variants of caseating granulomas, each with characteristics of human tuberculosis. In each instance, MTB were localized in fat cells or oil drops during initiation of caseating granulomas suggesting that necrosis was caused by activation of the toxicity of TDM toxicity. Evidence extending these findings to the lung was derived from the observation that in sensitized mice, as in humans, tuberculosis development stimulates accumulation of lipid selectively in alveoli. MTB preferentially associated with lipid droplets in developing necrotic foci in late-stage murine tuberculosis. This supports the hypothesis that pulmonary tuberculosis sequesters MTB in a protected environment that accumulates lipid until it is able to activate the toxicity of TDM and initiate necrosis that results in caseating granulomas.

Adipose Tissue↗

PubMed2004

Failure of CD1D-/- mice to elicit hypersensitive granulomas to mycobacterial cord factor trehalose 6,6'-dimycolate.

The present study defines pathologic differences in acute and hypersensitive responses to Mycobacterium tuberculosis glycolipid trehalose-6,6'-dimycolate (TDM, cord factor) in normal BALB/c mice and those deficient in group II CD1 molecule CD1d1. Mice immunized against TDM demonstrate hypersensitive responses, yet the mechanisms for TDM presentation remain elusive. Mice lacking CD1d (CD1D(-/-)) demonstrate dysregulated granulomatous response to TDM, compared with CD1D(+/-) heterozygous controls. Because CD1d-restricted T cells can regulate macrophage immune functions at mucosal surfaces, we hypothesized that CD1D(-/-) mice would show deficient TDM-induced hypersensitive pulmonary granulomatous response in which T cells play a central role. Control CD1D(+/+) mice sensitized and subsequently challenged with TDM demonstrated aggressive inflammation defined by monocytic lesions contained by CD3(+) lymphocytic cuffing. CD1D(-/-) mice demonstrated distinctly different pathologies, with edema present concurrent with extended, nonfocal mononuclear cell-based granulomatous reactions. Furthermore, CD1D(-/-) mice did not demonstrate destructive lesions, and CD3(+) lymphocytes were only loosely organized in proximity to reactive pathology. The CD1d-deficient mice demonstrated rapid increases in proinflammatory mRNAs, with significant differences in interferon-gamma (IFN-gamma) compared to the wild-type group. IFN-gamma, interleukin-6 (IL-6), and IL-12 proteins were significantly elevated in the CD1D(-/-) group compared with wild-type mice (p < 0.05) 2 days after TDM challenge. However, by 7 days postadministration, similar production for all cytokines and proinflammatory molecules examined was present in both groups of mice. These experiments provide evidence for a role for CD1d in mediation of pathology during hypersensitive responses to the mycobacterial glycolipid TDM.

Adjuvants, Immunologic↗

PubMed2003

Asian and Siberian ginseng as a potential modulator of immune function: an in vitro cytokine study using mouse macrophages.

BACKGROUND: Ginseng is a widely used herbal product in China, other Asian countries, and in the Unites States. There is a traditional belief that ginseng stimulates immune functions. In this study, the innate effects of Asian and Siberian ginsengs on cytokines and chemokines produced by cultured macrophages were examined. MATERIALS AND METHODS: The effects of Asian and Siberian ginseng on cytokines and chemokines produced by cultured macrophages were examined. Mouse macrophages (J774A.1) were incubated with Asian or Siberian ginseng at varying concentrations (1, 10, 100, and 1000 microg/ml) for 24 h and then harvested for RNA isolation. The expression levels of IL-1beta, IL-12, TNF-alpha, MIP-1 alpha, and MIP-2 mRNA were measured by quantitative PCR. RESULTS: Our data showed that Asian ginseng induced a statistically significant increase in IL-12 expression at both mRNA and protein levels. However, the minor twofold increase is probably biologically insignificant. No significant increase of IL-12 by Siberian ginseng was observed at any dose level studied. No significant change in IL-1beta, IL-15, TNF-alpha, or MIP-1alpha mRNA was observed by either Asian or Siberian ginseng treatment. CONCLUSIONS: Our data showed statistically significant differential regulation of IL-12 by Asian ginseng. Siberian ginseng did not show a statistically significant increase. We conclude that both Asian ginseng and Siberian ginseng cannot significantly stimulate innate macrophage immune functions that influence cellular immune responses. Therefore, contrary to the popular belief, Asian and Siberian ginseng may not stimulate immune function.

Adjuvants, Immunologic↗

PubMed2003

Effect of Asian and Siberian ginseng on serum digoxin measurement by five digoxin immunoassays. Significant variation in digoxin-like immunoreactivity among commercial ginsengs.

Asian and Siberian ginsengs contain glycosides with structural similarities to digoxin. We studied potential interference of ginseng in 5 digoxin immunoassays in 3 Asian (2 liquid extracts, 1 capsule) and 3 Siberian ginseng preparations (1 liquid extract, 2 capsules). With the fluorescence polarization immunoassay (FPIA), we observed apparent digoxin activity in 1 Asian liquid preparation and in the liquid extract and 1 capsule form of Siberian ginseng. In mice fed ginseng, we observed digoxin activities in the serum (Asian, 0.48-0.68 ng/mL [0.6-0.9 nmol/L]; Siberian, 0.20-0.47 ng/mL [0.3-0.6 nmol/L]), indicating that such interferences also occur in vivo. Serum pools prepared from samples from patients receiving digoxin and then supplemented with Asian or Siberian ginseng showed falsely increased digoxin values using the FPIA (e.g., for Asian ginseng, 1.54 ng/mL [2.0 nmol/L] vs control value, 1.10 ng/mL [1.4 nmol/L]) and falsely decreased values using the microparticle enzyme immunoassay (MEIA; 0.73 ng/mL [0.9 nmol/L] vs control value, 1.04 ng/mL [1.3 nmol/L]). Digoxin-like immunoreactive substances (DLISs) showed synergistic effects with ginsengs in interfering with the FPIA and MEIA for digoxin. No interference was observed with 3 other digoxin assays, even in the presence of elevated DLISs.

Animals↗

PubMed2002

In vivo digoxin-like immunoreactivity in mice and interference of Chinese medicine Danshen in serum digoxin measurement: elimination of interference by using a chemiluminescent assay.

BACKGROUND: Danshen, a traditional Chinese medicine used in the management of cardiovascular diseases, is available without prescription in the US. Because Danshen is used to treat cardiovascular diseases, we studied the potential interference of Danshen with serum digoxin measurement using various immunoassays. METHODS: Blood was collected 1 day before and then 1 and 2 h after feeding mice with Danshen. The apparent digitoxin activities were measured by the fluorescence polarization immunoassay (FPIA). We also added microliter amounts of Danshen extract to digoxin pools prepared from patients receiving digoxin. The digoxin concentrations were measured using the fluorescence polarization immunoassay (FPIA), microparticle enzyme immunoassay (MEIA) and chemiluminescent assay (CLIA). The observed values were compared with original values. We also fed mice with Danshen. RESULTS: We observed measurable digoxin-like immunoreactivity in sera of mice after feeding with Danshen. We also observed falsely lower digoxin concentrations (negative interference) when MEIA was used for digoxin measurement. However, serum digoxin concentrations were falsely elevated with FPIA. We observed no interference of Danshen in serum digoxin measurement using the CLIA. CONCLUSION: Danshen appears to contain digoxin-like immunoreactivity but does not interfere with serum digoxin measurement when CLIA was used.

Animals↗

PubMed2002

Activated charcoal is more effective than equilibrium dialysis in removing Chinese medicines Chan Su and Dan Shen from serum and activated charcoal also prevents further absorption of these agents from G.I. tract in mice: monitoring the effect in clinical laboratory by measuring digoxin activity in serum.

BACKGROUND: Chinese medicines are freely available without prescription and are widely used by the general population. Chan Su and Dan Shen are both indicated for the treatment of cardiac diseases. Severe toxicity from Chan Su has been reported. We studied the possibility of removing Chan Su and Dan Shen from human sera using activated charcoal and equilibrium dialysis, and also examined the potential benefit of preventing absorption of these agents from the G.I. tract in the mouse model. METHODS: For in vitro studies, drug-free serum pools were supplemented with Chan Su or Dan Shen and then either treated with activated charcoal (10 and 25 mg/ml), or passed through a column packed with activated charcoal. Serum pools supplemented with Chan Su or Dan Shen were also subjected to equilibrium dialysis against phosphate buffer (pH 7.4) using dialysis membrane with molecular cut-off of 25,000 Da. Removal of Chan Su or Dan Shen from the serum was monitored by measuring the apparent digoxin concentration using the fluorescence polarization immunoassay (FPIA) for digoxin (Abbott Laboratories). RESULTS: We observed the fast and effective removal of both Chan Su and Dan Shen from the serum by activated charcoal. We also observed significant removal of both Chan Su and Dan Shen when the serum pools containing these Chinese medicines were passed through columns packed with activated charcoal. Although equilibrium dialysis was also effective in removing these Chinese medicines from the serum, 24 h was required for complete removal of Dan Shen activity, and for Chan Su, complete removal was not achieved even after 24 h. In our in vivo model, we observed significantly less digoxin activity in the group of mice that received activated charcoal compared to the control group. CONCLUSIONS: Activated charcoal is effective in preventing absorption of these Chinese medicines from the G.I. tract and can also remove these agents from the serum.

Animals↗

PubMed2002

Lactoferrin immunomodulation of DTH response in mice.

Improved nontoxic adjuvants, especially adjuvants capable of inducing cell-mediated immunity (CMI), are needed for research in immunology and for development of human and veterinary vaccines. Bovine Lactoferrin, an effector molecule shown to directly participate in host defense, was assessed at various concentrations as an adjuvant component for induction of DTH responses to sheep red blood cells (SRBC). Subcutaneous immunization with Lactoferrin enhanced delayed type hypersensitivity (DTH) in CBA mice in a dose-dependent fashion; DTH responses were most significantly increased when sensitization was accomplished using Lactoferrin at 50 microg/dose and 250 microg/dose. Furthermore, Lactoferrin admixed with suboptimal dose of SRBC enhanced DTH responses by over 17-fold. Peritoneal cells collected from mice intraperitoneally injected with a 100 microg/dose of Lactoferrin demonstrated modest, but significant, production of TNF-alpha, IL-12 and MIP-1alpha when cultured in vitro, compared to saline-injected controls. J774A.1 murine macrophages stimulated with Lactoferrin resulted in increased TNF-alpha protein production, and upregulated IL-12 and IL-15 mRNA. Levels of message for chemokines MIP-1alpha and MIP-2 were also increased in a dose-dependent way. Taken together, these results indicate that Lactoferrin as an adjuvant may stimulate macrophages to generate a local environment likely to push immune responses towards development and maintenance of CMI.

Adjuvants, Immunologic↗

PubMedDate not supplied

Mycobacterial glycolipid cord factor trehalose 6,6'-dimycolate causes a decrease in serum cortisol during the granulomatous response.

Serum cortisol levels were evaluated in mice following intravenous administration of purified mycobacterial glycolipid trehalose 6,6'-dimycolate (TDM). C57BL/6 mice develop lung granulomas in response to TDM, while A/J mice are deficient in this process. Administration of TDM to C57BL/6 mice led to a rapid reduction in serum cortisol, concurrent with initiation of the granulomatous response and cytokine and chemokine mRNA induction. Cortisol levels were lowest on day 5 after TDM administration, but there was significant production of IL-6, TNF-alpha and IL-1beta messages. Granuloma formation and full immune responsiveness to TDM were only apparent upon a sufficient decrease in levels of systemic cortisol. Treatment of the C57BL/6 mice with hydrocortisone abolished inflammatory responses. Histologically nonresponding A/J mice exhibited higher constitutive serum cortisol and demonstrated different kinetics of cortisol reduction upon administration of TDM. A/J mice demonstrated hyperplastic morphology in the suprarenal gland with a high degree of vacuolization in the medullary region and activation of cells in the zona fasciculata and zona reticularis. The A/J mice were dysregulated with respect to cytokine responses thought to be necessary during granuloma formation. The high constitutive serum cortisol in the A/J mice may therefore contribute to pulmonary immunoresponsiveness and the establishment of an environment counterproductive to the initiation of granulomatous responses. The identification of a mycobacterial glycolipid able to influence serum cortisol levels is unique and is discussed in relation to immunopathology during tuberculosis disease.

Adrenal Cortex↗