The detection of alloantibodies against red cells in patients with warm-type autoimmune haemolytic anaemia.
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Anemia, Hemolytic, Autoimmune↗
Biomedical subjects
M Goldman
Publications and source records attributed to M Goldman.
Community outreach at biomedical research facilities.
For biomedical researchers to fulfill their responsibility for protecting the environment, they must do more than meet the scientific challenge of reducing the number and volume of hazardous materials used in their laboratories and the engineering challenge of reducing pollution and shifting to cleaner energy sources. They must also meet the public relations challenge of informing and involving their neighbors in these efforts. The experience of the Office of Community Liaison of the National Institutes of Health (NIH) in meeting the latter challenge offers a model and several valuable lessons for other biomedical research facilities to follow. This paper is based on presentations by an expert panel during the Leadership Conference on Biomedical Research and the Environment held 1--2 November 1999 at NIH, Bethesda, Maryland. The risks perceived by community members are often quite different from those identified by officials at the biomedical research facility. The best antidote for misconceptions is more and better information. If community organizations are to be informed participants in the decision-making process, they need a simple but robust mechanism for identifying and evaluating the environmental hazards in their community. Local government can and should be an active and fully informed partner in planning and emergency preparedness. In some cases this can reduce the regulatory burden on the biomedical research facility. In other cases it might simplify and expedite the permitting process or help the facility disseminate reliable information to the community. When a particular risk, real or perceived, is of special concern to the community, community members should be involved in the design, implementation, and evaluation of targeted risk assessment activities. Only by doing so will the community have confidence in the results of those activities. NIH has involved community members in joint efforts to deal with topics as varied as recycling and soil testing. These ad hoc efforts are more likely to succeed if community members and groups have also been included in larger and longer term advisory committees. These committees institutionalize the outreach process. This can provide the facility with vocal and influential allies who create an independent line of communication with the larger community.
Academies and Institutes↗
Imaging after urinary tract infection in male neonates.
OBJECTIVE: To assess the frequency of urinary tract anomalies in male neonates <8 weeks old who presented with urinary tract infection (UTI), and to evaluate a suitable imaging approach after the initial infection. DESIGN: During a period of 4.5 years, from July 1994 through December 1998, 45 male neonates <8 weeks old (range: 5-56 days; mean: 23.77 days) with UTI were hospitalized. All patients had an ultrasound (US) and a voiding cystourethrogram (VCUG), except 1 neonate in whom VCUG was unsuccessful because of technical problems. A dimercaptosuccinic acid (DMSA) scan was recommended to all patients but was performed only in 30 of 45, most of them with an abnormal VCUG. The renal scan was performed at least 4 months after the UTI. RESULTS: Urinary tract abnormalities were observed in 22 of 45 male neonates. Nineteen had vesicoureteral reflux (VUR), 1 had VUR and a double collecting system, 1 had VUR and a posterior urethral valve, and 1 had an ureteropelvic junction stricture. Renal atrophy or scars, as demonstrated by DMSA scan, were detected almost exclusively in neonates with VUR grade 3 and above. Only 1 neonate with VUR grade 1 had a pathologic DMSA, and the US of this male also demonstrated renal atrophy. Escherichia coli was the pathogen in 62% (28 of 45), and 9 boys had bacteremia. CONCLUSION: We suggest that US and VCUG should be performed routinely after the initial UTI in male neonates. Renal scan should be reserved for those cases in which the US suggests renal parenchymal damage or when VCUG detects VUR grade 3 and above.
Chelating Agents↗
Adolescents are not adults: developmental considerations in alcohol users.
Much of the work in adolescent substance abuse assessment and treatment has been a direct transport from tools and modalities used in adult substance use populations. There was a consensus among symposium participants that developmental issues are important in assessment, evaluation, and treatment of adolescents with substance use disorders. These issues directly impact outcome at all levels. Presentations from the symposium may be helpful for conceptualizing the problems of adolescent substance use as well as formulating strategies for future research. Information from the symposium may be viewed as a springboard for future research and clinical intervention in adolescent substance abuse.
Adolescent↗
Hepatitis C lookback in Canada.
BACKGROUND AND OBJECTIVES: Since March 1990, all blood donations in Canada are screened by enzyme-linked immunosorbent assay (EIA) for antibodies to HCV, with confirmatory testing done using a recombinant immunoblot assay (RIBA). Because HCV may cause chronic asymptomatic hepatitis, in 1995, the Canadian Red Cross began targeted HCV lookback studies on all confirmed positive donations. These have been continued by the two new operators of the blood system in Canada, Héma-Québec and the Canadian Blood Services. Subsequent to recommendations made in the public inquiry into the Canadian blood system, led by judge Krever, general lookback through letter notification of all patients transfused in the years prior to the introduction of anti-HCV testing was initiated in several pediatric hospitals, and later in several Canadian provinces. MATERIALS AND METHODS: Targeted HCV lookback was done for all donors confirmed positive by RIBA testing from the start of HCV testing in 1990. In 1999, stored RIBA 2 indeterminate samples were re-tested by RIBA 3, and lookback performed on confirmed positive donations. In the province of Quebec, hospitals were surveyed to determine methods and resources involved in lookback. Provinces performing general letter notification entered hospital transfusion records into a central transfusion data bank, and performed linkage with other provincial data banks to remove deceased patients and obtain current addresses. RESULTS: As of January 2000, targeted lookback had been completed on 4,859 components of 1,628 anti-HCV positive repeat donors. 2,991 recipients were deceased, and 451 were not found or tested. Of the 1,422 recipients tested, 954 (67%) were anti-HCV positive. Approximately half were already aware of their HCV status. Lookback efforts in hospitals were hampered by lack of resources and manual records. General letter notification in British Columbia (BC) and Prince Edward Island (PEI) led to the testing of 38,960 and 1,953 recipients respectively, with 5.0 and 2.2% of tested recipients found to be anti-HCV positive. CONCLUSION: In completed targeted lookback investigations, 19% of components are eventually linked to an anti-HCV positive recipient. These results are very similar to those obtained in other countries, such as Denmark and the UK. In general letter notification lookbacks, the frequency of anti-HCV in the tested recipients is approximately twice the frequency of the general population.
Antibodies, Viral↗
[Th2 lymphocytes in man: a new cause of hypereosinophilic syndrome].
Interleukin-5 produced by Th2-type lymphocytes is involved in the pathogenesis of several hypereosinophilic disorders. We have identified clonal Th2 cells in the peripheral blood of three patients with the idiopathic hypereosinophilic syndrome. Costimulatory signaling through B7/CD28 and LFA-3/CD2 pathways cooperates with an autocrine interleukin-2/interleukin-2 receptor loop for the survival and proliferation of these Th2 cells, as well as their production of cytokines, independently of T cell receptor engagement. The high-level of spontaneous apoptosis displayed by these cells was inhibited by interleukin-2 and interferon-g. New therapeutic strategies could result from our observations. Indeed, the hypereosinophilic syndrome may represent an unexpected indication for new immunomodulatory molecules such as CTLA4-Ig and anti-il-2 receptor antibodies.
B7-1 Antigen↗
Ethics in practice. The case of Mr. W.
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Aged↗
Downregulation of antigen-presenting cell functions after administration of mitogenic anti-CD3 monoclonal antibodies in mice.
Antibodies against CD3epsilon are widely used as immunosuppressive agents. Although it is generally assumed that these reagents exert their immunomodulatory properties by inducing T-cell deletion and/or inactivation, their precise mechanism of action remains to be elucidated. Using a murine model, we demonstrate in this report that administration of anti-CD3epsilon antibodies causes the migration and maturation of dendritic cells (DC) in vivo, as determined by immunohistochemical analysis. This maturation/migration process was followed by selective loss of splenic DC, which resulted in a selective inhibition of antigen-presenting cell (APC) functions in vitro. Spleen cells from anti-CD3epsilon-treated animals were unable to productively stimulate naive alloreactive T cells and Th1-like clones in response to antigen, while retaining the ability to present antigen to a T-cell hybridoma and Th2 clones. Anti-CD3epsilon treatment was found to induce a selective deficiency in the ability of spleen cells to produce bioactive interleukin-12 in response to CD40 stimulation. APC dysfunction was not observed when nonmitogenic forms of anti-CD3epsilon antibodies were used, suggesting that splenic DC loss was a consequence of in vivo T-cell activation. Nonmitogenic anti-CD3epsilon monoclonal antibodies were found to be less immunosuppressive in vivo, raising the possibility that APC dysfunction contributes to anti-CD3epsilon-induced immunomodulation. Collectively, these data suggest a novel mechanism by which mitogenic anti-CD3epsilon antibodies downregulate immune responses.
Animals↗
[Hemophagocytic syndrome].
Hemophagocytic syndrome is a rare, fulminant disease characterized by generalized histiocytic proliferation associated with phagocytosis of erythrocytes, platelets, and to a lesser extent, of white blood cells. We report a 2-year-old boy admitted with high fever and irritability, with a rash, marked hepatomegaly and generalized lymphadenopathy. Liver function tests were abnormal and there was thrombocytopenia and hyperlipidemia. Bone marrow aspiration revealed hemophagocytosis. Despite intensive treatment with steroids, intravenous immunoglobulin and cytotoxic drugs, he died within 10 weeks.
Bone Marrow↗
IL-5 mediates eosinophilic rejection of MHC class II-disparate skin allografts in mice.
CD4 T cells play a crucial role in the acute rejection of MHC class II-disparate skin allografts, mainly by Fas/Fas ligand-mediated cytotoxicity. Because recent observations indicate that eosinophils may be found within allografts rejected by CD4 T cells, we evaluated the role played by IL-5, the main eosinophil growth factor, and by eosinophils in the rejection of MHC class II-disparate skin grafts. C57BL/6 mice rapidly rejected MHC class II-disparate bm12 skin grafts. Rejected skins contained a dense, aggressive eosinophil infiltrate. Lymphocytes isolated from lymph nodes draining rejected bm12 skin were primed for IL-5 secretion, and IL-5 mRNA was present within rejected grafts. The IL-5/eosinophil pathway played an effector role in allograft destruction, because the rejection of bm12 skin was significantly delayed in IL-5-deficient mice as compared with wild-type animals. The role of the IL-5/eosinophil pathway was further investigated in MHC class II-disparate donor-recipient strains unable to establish Fas/Fas ligand interactions. Fas ligand-deficient gld/gld mice rejected bm12 skins, and bm12 mice rejected Fas-deficient lpr/lpr C57BL/6 skins. Neutralization of IL-5 prevented acute rejection in both combinations. We conclude that MHC class II-disparate skin allografts trigger an IL-5-dependent infiltration of eosinophils that is sufficient to result in acute graft destruction.
Acute Disease↗
CD3 antibody-induced IL-10 in renal allograft recipients: an in vivo and in vitro analysis.
BACKGROUND: The first administration of CD3 monoclonal antibodies, such as anti-human CD3 (OKT3), induces a massive release of several cytokines, including tumor necrosis factor alpha (TNF-alpha), interferon (IFN)-gamma, interleukin (IL)-2, IL-3, IL-6, and granulocyte-macrophage colony-stimulating factor. METHODS: Cytokine levels in patient's sera were measured by specific ELISA. In vitro cultures were performed using OKT3-stimulated peripheral blood mononuclear cells and/or whole blood from patients and normal controls. RESULTS: Here we describe that OKT3 administration to human renal allograft recipients also leads to a significant release of IL-10. Contrasting with most OKT3-induced cytokines, such as TNF-alpha whose release is transient, IL-10 levels show a more progressive increase, they peak only by 4-8 hr after the first OKT3 injection and persist longer. Thus, significant IL-10 levels are still detectable at the time of the second and the third OKT3 injection. Administration of corticosteroids, 1 hr before the first OKT3 injection, significantly reduced both TNF-alpha and IL-10 release. Experiments were performed to evaluate the source(s) of IL-10 and its (their) influence on the initial T-cell activation. When stimulated in culture with soluble OKT3, the production of IL-10 was dependent on the cooperation between T lymphocytes and monocytes. It is important that, as assessed through the use of a specific neutralizing antibody, the endogenous IL-10 produced in the co-culture system exerted a negative feed-back on the release of the other pro-inflammatory CD3-induced cytokines, which was reproducible. CONCLUSION: These results are supportive of a major role of IL-10 in the down-modulation of the OKT3-triggered T-cell activation cascade.
CD3 Complex↗
Down-regulation of interleukin-2 and interferon-gamma and maintenance of interleukin-4 and interleukin-10 production after administration of an anti-CD3 monoclonal antibody in mice.
BACKGROUND: Activating anti-CD3 monoclonal antibodies (mAbs), such as OKT3, are potent immunosuppressive agents that are widely used in clinical transplantation. We investigated whether the in vivo induction of T cell unresponsiveness contributes to the immunosuppressive properties of the anti-mouse-CD3 mAb 145-2C11. METHODS: After a single in vivo administration of 145-2C11 residual T cells were restimulated in vivo and in vitro to assess cytokine production. Mice were also transplanted with allogeneic skin 9 days after 145-2C11 administration to investigate whether the immunosuppressive properties of the antibody persist after the reexpression of the T cell receptor. RESULTS: Pretreatment with anti-CD3 mAbs caused a profound deficit in both interleukin- (IL) 2 and interferon- (IFN) y secretion upon restimulation in vivo, whereas IL-4 was only partially inhibited and IL-10 production was significantly increased. Purified T cells obtained from mice injected with anti-CD3 mAb also displayed deficient IL-2 and IFN-gamma production together with persisting IL-4 and IL-10 secretion. 145-2C11 had immunosuppressive properties that per sisted after the reexpression of the T cell receptor because mice transplanted with allogeneic skin 9 days after a single anti-CD3 mAb injection still had significantly prolonged graft survival (14.1+/-0.6 days vs. 10.7+/-0.4 days in controls, P<0.02). Blocking IL-4 and IL-10 by neutralizing mAbs further prolonged skin graft survival in mice injected with 145-2C11 (18.3+/-0.7 vs. 14.8+/-0.6 days, P<0.02). CONCLUSION: The in vivo administration of the 145-2C11 anti-CD3 mAb results in the selective inhibition of Thl-type cytokine secretion upon restimulation, which correlates with a state of immunosuppression. The persistent production of Th2-type cytokines does not contribute to the anti-CD3 mAb-mediated prolonged survival of skin allografts in our experimental model.
Animals↗
T-cell receptor-independent activation of clonal Th2 cells associated with chronic hypereosinophilia.
We recently observed a clonal expansion of CD3(-)CD4(+) T cells secreting Th2-type cytokines in patients presenting chronic hypereosinophilia. As clonal T cells isolated from such patients did not spontaneously secrete cytokines in vitro, we reasoned that costimulatory signals delivered by antigen-presenting cells might be required to induce their full activation. To address this question, we investigated in two such patients the responses of CD3(-)CD4(+) T cells to dendritic cells (DC). DC elicited proliferation and production of interleukin-5 (IL-5) and IL-13 by clonal cells from patient 1 and upregulated their expression of CD25 (IL-2R-alpha). These effects were abolished when blocking monoclonal antibodies (MoAbs) against IL-2R-alpha and IL-2 were added to cocultures, indicating critical involvement of an autocrine IL-2/IL-2R pathway. Cells from patient 2 were stimulated by DC to produce Th2 cytokines only when rIL-2 or rIL-15 was added to cocultures. In both patients, addition of inhibitory MoAbs against B7-1/B7-2 or CD2 to cocultures resulted in dramatic reduction of cytokine production and inhibited CD25 upregulation. Thus, TCR/CD3-independent activation of clonal Th2 cells by DC is an IL-2-dependent process, which requires signaling through CD2 and CD28.
Adult↗
The agouti gene product stimulates pancreatic [beta]-cell Ca2+ signaling and insulin release.
Ubiquitous expression of the mouse agouti gene results in obesity and hyperinsulinemia. Human agouti is expressed in adipose tissue, and we found recombinant agouti protein to stimulate lipogenesis in adipocytes in a Ca(2+)-dependent fashion. However, adipocyte-specific agouti transgenic mice only became obese in the presence of hyperinsulinemia. Because intracellular Ca(2+) concentration ([Ca(2+)](i)) is a primary signal for insulin release, and we have shown agouti protein to increase [Ca(2+)](i) in several cell types, we examined the effects of agouti on [Ca(2+)](i) and insulin release. We demonstrated the expression of agouti in human pancreas and generated recombinant agouti to study its effects on Ca(2+) signaling and insulin release. Agouti (100 nM) stimulated Ca(2+) influx, [Ca(2+)](i) increase, and a marked stimulation of insulin release in two beta-cell lines (RIN-5F and HIT-T15; P < 0. 05). Agouti exerted comparable effects in isolated human pancreatic islets and beta-cells, with a 5-fold increase in Ca(2+) influx (P < 0.001) and a 2.2-fold increase in insulin release (P < 0.01). These data suggest a potential role for agouti in the development of hyperinsulinemia in humans.
Agouti Signaling Protein↗
Inhibition of human dendritic cell functions by methylprednisolone.
BACKGROUND: The aim of this study was to better define how glucocorticoids influence primary human T cell responses. Dendritic cells (DC*) are the most effective antigen presenting cells able to activate naive T cells. Previous studies have shown that dexamethasone impaired the function of murine DC. Here, we analyzed how methylprednisolone (MP) might affect the function and maturation of human DC. METHODS: Human DC were generated from peripheral blood mononuclear cells cultured in granulocyte macrophage-colony stimulating factor and interleukin (IL)4. DC maturation was induced either by lipopolysaccharide (LPS) or by fibroblast transfected with the CD40-ligand gene (3T6-CD40L). DC phenotype was characterized by flow cytometric analysis, their cytokine production by ELISA. The ability of DC to activate naive T cells was evaluated in mixed leukocyte reactivity. RESULTS: Although MP did not affect viability of DC, it enhanced their antigen uptake and down-regulated their basal expression of CD86. The expression of CD80 and CD54 by DC was slightly decreased and HLA-DR expression was not modified. MP prevented LPS-induced DC maturation as assessed by the inhibition of CD86, CD80 and CD54 up-regulation, CD83 induction and production of TNF-alpha, IL-6, and IL-12. In contrast, when DC were stimulated by 3T6-CD40L, MP prevented only the synthesis of IL-12. Moreover, MP-treated DC were deficient in their ability to elicit proliferative responses of CD4+CD45RA+ allogeneic T cells as well as their synthesis of interferon (IFN)-gamma, IL-5, and IL-13. CONCLUSION. Glucocorticoids exert potent suppressive effects on human DC and thereby inhibit the induction of primary T cell responses.
Antigens↗
Single cell analysis of antigen-specific T cell responses in HIV-infected individuals.
Antigen-specific and polyclonally induced T cell responses were analyzed in 10 HIV-infected individuals and in 14 controls by enumerating the numbers of tetanus toxoid (TT)-specific and phytohemagglutinin (PHA)-induced IFN-gamma-secreting cells (SC) and IL-4-SC using an enzyme-linked immunospot assay. Whereas the numbers of IFN-gamma-SC in HIV-infected patients were not different from those of the controls in response to an in vitro stimulation with PHA, they were significantly decreased in response to an in vitro stimulation with TT, both before and after a TT booster. Cell depletion experiments indicated that this difference was related to an impairment of CD4(+) T-cell-mediated TT-specific IFN-gamma secretion. Concerning IL-4, the numbers of both polyclonally induced IL-4-SC and TT-specific IL-4-SC were significantly lower in HIV-infected patients than in the controls. It is concluded that secretion of antigen-specific cytokines of both Th1 and Th2 types is depressed in HIV-infected patients.
Adult↗
Transfusion-transmitted malaria in Canada.
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Adult↗
N-acetyl-L-cysteine inhibits primary human T cell responses at the dendritic cell level: association with NF-kappaB inhibition.
N-acetyl-L-cysteine (NAC) is an antioxidant molecule endowed with immunomodulatory properties. To investigate the effect of NAC on the induction phase of T cell responses, we analyzed its action on human dendritic cells (DC) derived from adherent PBMC cultured with IL-4 and granulocyte-macrophage CSF. We first found that NAC inhibited the constitutive as well as the LPS-induced activity of the transcription factor NF-kappaB. In parallel, NAC was shown to down-regulate the production of cytokines by DC as well as their surface expression of HLA-DR, CD86 (B7-2), and CD40 molecules both at the basal state and upon LPS activation. NAC also inhibited DC responses induced by CD40 engagement. The inhibitory effects of NAC were not due to nonspecific toxicity as neither the viability of DC nor their mannose receptor-mediated endocytosis were modified by NAC. Finally, we found that the addition of NAC to MLR between naive T cells and allogeneic DC resulted in a profound inhibition of alloreactive responses, which could be attributed to a defect of DC as APC-independent T cell responses were not inhibited by NAC. Altogether, our results suggest that NAC might impair the generation of primary immune responses in humans through its inhibitory action on DC.
Acetylcysteine↗