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Background The Imp lantation of A utologous C D133 + S t em Cells in Patients Undergoing CABG (IMPACT-CABG) trial is investigating the feasibility, safety, and efficacy of intramyocardial injections of autologous CD133 + stem cells during coronary artery bypass grafting (CABG) in patients with chronic ischemic cardiomyopathy. We are reporting the results of the first 5 open-label patients. Methods Bone marrow was harvested from iliac crests and stem cells were isolated using the CliniMACS CD133 + Reagent System (Miltenyi Biotec, GmbH, Bergisch Gladbach, Germany). Patients received CABG, followed by CD133 + cellular injection in the revascularized hypokinetic myocardium. Results Five males New York Heart Association (NYHA) class III patients aged 64 ± 10 years were treated. Immunomagnetic cell processing allowed an average of 100 ± 48-fold enrichment in CD133 + cells, with 92 ± 11% recovery after selection. Mean number of CD133 + cells injected was 8.4 ± 1.2 million. There were no protocol-related complications during the 18-month follow-up and all patients improved to NYHA class I. Six-month echocardiography showed no significant improvement in left ventricular ejection fraction (34 ± 2% at baseline vs 38 ± 12%: P = 0.50). However, cardiac magnetic resonance showed that systolic wall thickening increased from 15.0 ± 10.5% to 29.0 ± 22.1% ( P = 0.01). In addition, mean segmental wall thickness also improved in comparison with baseline (10.7 ± 2.7% to 12.1 ± 4.8%; P Conclusions This work represents the first Canadian experience with CD133 + stem cells for the treatment of chronic ischemic cardiomyopathy. These results demonstrate the initial safety and feasibility of the IMPACT-CABG pilot trial. Subsequent patients are now being randomized to receive either CD133 + stem cell or placebo.

Restriction of T cell responses to a few epitopes (immunodominance) is a central feature of immune responses. We analyzed the entire transcriptome of effector CD8 T cells specific for a dominant (H7a) and a cryptic (HY) mouse Ag and performed a longitudinal analysis of selected T cell differentiation markers. We found that Ag specificity had a relatively modest influence on the repertoire of genes that are transcriptionally modulated by the CD8 T cell differentiation program. Although the differentiation programs of anti-H7a and anti-HY T cells were similar, they did not progress simultaneously. The expansion peak of anti-H7a T cells was reached on day 10 while that of anti-HY T cells was attained on days 15–20. Between days 10 and 20, anti-H7a T cells were in the contraction phase and anti-HY T cells in the expansion phase. Furthermore, expansion and development of effector function were well-synchronized in anti-H7a T cells but were disconnected in anti-HY T cells. We propose that, by leading to selective expansion of the fittest CD8 T cells, immunodominance may be beneficial to the host. Inhibition of the T cell response to cryptic Ag would ensure that host resources (APC, cytokines) for which T cells compete are devoted to T cells with the best effector potential. One implication is that favoring expansion of the fittest effector T cells in general may be more important than increasing the diversity of the T cell repertoire.

T cells responsive to minor histocompatibility (H) antigens are extremely effective in curing leukemia but it remains unknown whether they can eradicate solid tumors. We report that injection of CD8(+) T cells primed against the immunodominant H7(a) minor H antigen can cure established melanomas in mice. Tumor rejection was initiated by preferential extravasation at the tumor site of interferon (IFN)-gamma-producing H7(a)-specific T cells. Intratumoral release of IFN-gamma had two crucial effects: inhibition of tumor angiogenesis and upregulation of major histocompatibility complex (MHC) class I expression on tumor cells. Despite ubiquitous expression of H7(a), dissemination of a few H7(a)-specific T cells in extralymphoid organs caused neither graft-versus-host disease (GVHD) nor vitiligo because host nonhematopoietic cells were protected by their low expression of MHC class I. Our preclinical model yields unique insights into how minor H antigen-based immunotherapy could be used to treat human solid tumors.

When presented alone, H7a and HY antigens elicit CD8 T-cell responses of similar amplitude, but H7a totally abrogates the response to HY when both antigens are presented on the same antigen-presenting cell. We found that H7a- and HY-specific T-cell precursors had similar frequencies in nonimmune mice and expressed similar levels of CD5. The H7a-specific CD8 T-cell repertoire harvested at the time of primary response showed highly restricted T-cell receptor (TCR) diversity. Furthermore, T cells specific for H7a and HY expressed equivalent levels of CD8 and TCR and displayed similar tetramer decay rates. The key difference was that anti-H7a T cells exhibited a much more rapid TCR:epitope on-rate than anti-HY T cells. Coupled with evidence that primed CD8 T cells limit the duration of antigen presentation by killing or inactivating antigen-presenting cells, our data support a novel and simple model for immunodomination: the main feature of T cells that exert immunodomination is that, compared with other T cells, they are functionally primed after a shorter duration of antigen presentation.

The B6(dom1) minor histocompatibility antigen (MiHA) is a model antigen, since it is both the epitome of an immunodominant epitope and an ideal target for adoptive cancer immunotherapy. Based on DNA sequencing and MS/MS analyses, we report that B6(dom1) corresponds to amino acids 770-778 (KAPDNRETL) of a protein we propose to call SIMP (source of immunodominant MHC-associated peptides) that is encoded by a mouse homolog of the yeast STT3gene. STT3, a member of the oligosaccharyltransferase complex, is essential for cell proliferation. Phenotypic and genotypic analyses among eight strains of mice revealed a precise correlation between susceptibility or resistance to B6(dom1)-specific cytotoxic T lymphocytes (CTLs) and the presence of a Glu vs Asp amino acid at position 776 of the SIMP protein, respectively. Strikingly, while the difference in the amino acid sequence 770-778 encoded by the two SIMP alleles represents a very conservative substitution, these allelic peptides were not crossreactive at the CTL level, and both peptides were immunodominant when presented to mice homozygous for the opposite allele. In addition, we have cloned a human ortholog of SIMP whose predicted protein shares 97% amino acid identity with mouse SIMP. These results strengthen the concept that MHC class-I-associated MiHAs originate as a consequence of rare polymorphisms among highly conserved genes. Furthermore, the notion that a peptide differing from a self analog by a single methylene group can be immunodominant has implications regarding our understanding of the mechanisms of immunodominance.

Adoptive transfer of T cells reactive to minor histocompatibility antigens has the unmatched ability to eradicate malignant hematopoietic cells. Unfortunately, its use is hampered by the associated graft-versus-host disease. The critical issue of a possible dissociation of the antileukemic effect and graft-versus-host disease by targeting specific minor histocompatibility antigens remains unresolved because of the unknown nature and number of minor histocompatibility antigens necessary or sufficient to elicit anti-leukemic activity and graft-versus-host disease. We found that injection of T lymphocytes primed against a single major histocompatibility complex class I-restricted immunodominant minor histocompatibility antigen (B6dom1) caused no graft-versus-host disease but produced a curative anti-leukemic response. Avoidance of graft-versus-host disease required that no other host-reactive T cells be co-injected with T cells primed with B6dom1. Here we show that effective and non-toxic immunotherapy of hematologic malignancies can be achieved by targeting a single immunodominant minor histocompatibility antigen.

Donor lymphocyte infusions are particularly effective for remission induction in malignant cells in patients who relapse after allogeneic progenitor cell transplantation (PCT) and who remain sensitive to the administration of unprimed donor T and/or natural killer (NK) cells present in donor lymphocyte infusions. To determine whether relapse after unmanipulated PCT could be ascribed to donor T and/or NK cell loss or tolerization, we evaluated the chimeric status of 81 patients with haematological malignancies who were receiving allogeneic unmanipulated PCT. The incidence of mixed chimaerism (MC) in unfractionated mononuclear leucocyte samples decreased rapidly after transplant, and was not detectable 4 months after PCT, even in patients who subsequently relapsed. The chimeric status of immune effector cell subsets was then evaluated in 15 patients at the time of relapse. All adults demonstrated complete donor haematopoiesis (CDH) for all cell lineages, whereas T- and NK-cell MC was only found in patients younger than age 13 years (P = 0.004). MC was not found in T nor NK cells of a control group consisting of age-matched paediatric patients in remission after allogeneic PCT. Thus, in adults, T and NK cell MC disappears early after unmanipulated allogeneic PCT and is absent at the time of relapse. However, the identification of donor T and NK cell loss in the paediatric relapsed but not remission patients suggests a distinct mechanism of relapse.

1. The potent coronary vasoconstrictor, endothelin-1 (ET-1) may also regulate neutrophil traffic into tissues. The aim of the present study was to characterize the endothelin receptors responsible and to investigate the underlying mechanisms. 2. ET-1 (1 nM - 1 microM) markedly enhanced attachment of human neutrophils to lipopolysaccharide-, and to a lesser extent, to ET-1-activated human coronary artery endothelial cells (HCAEC). This can partially be blocked by monoclonal antibodies against E-selectin, L-selectin or CD18, whereas combination of the three antibodies inhibited adhesion by approximately 83%. Increases in neutrophil adhesion evoked by ET-1 were also blocked by the platelet-activating factor (PAF) antagonists, BN 52021 (50 microM) and WEB 2086 (10 microM). 3. ET-1 downregulated the expression of L-selectin and upregulated expression of CD11b/CD18 and CD45 on the neutrophil surface and induced gelatinase release with EC50 values of approximately 2 nM. These actions of ET-1 were almost completely prevented by the ET(A) receptor antagonist FR 139317 (1 microM) and the ET(A)/ET(B) receptor antagonist bosentan (10 microM), whereas the ET(B) receptor antagonist BQ 788 (1 microM) had no effect. ET-1 slightly increased the expression of E-selectin and ICAM-1 on HCAEC, that was prevented by BQ 788, but not by FR 139317. 4. Receptor binding studies indicated the presence of ET(B) receptors (KD: 40 pM) on phosphoramidon-treated HCAEC and the predominant expression of ET(A) receptors (KD: 38 pM) on neutrophils. 5. These results indicate that promotion by ET-1 of neutrophil adhesion to HCAEC is predominantly mediated through activation of ET(A) receptors on neutrophils and subsequent generation of PAF.

CD19 (B4) is a signal transduction molecule restricted to the B-cell lineage and the target of the immunotoxin anti-B4–blocked ricin (anti-B4–bR), which is composed of the monoclonal antibody (MoAb) anti-B4 and the modified plant toxin blocked ricin. To explore the influence of conjugation of blocked ricin to anti-B4 on functional activation of CD19, we investigated the effects of anti-B4–bR, and that of unconjugated anti-B4, on intracellular calcium mobilization and ligand/receptor internalization. The data showed that anti-B4–bR was more potent than anti-B4 in triggering cell calcium mobilization. Two other immunotoxins that bind to the B-cell surface, anti-CD20–bR and anti-CD38–bR, were devoid of the calcium increasing effect of anti-B4–bR. Furthermore, anti-B4 conjugated to ricin A-chain was also without effect in Namalwa cells, indicating that the ricin B-chain component was required for anti-B4–bR effect. Anti-B4–bR-induced calcium mobilization was inhibited in the presence of lactose, yet the calcium response induced by cross-linking anti-B4–bR with a second step antibody was not affected. The extent of CD19 modulation induced by anti-B4–bR was higher than that induced by anti-B4, and lactose dampened the effect of the immunotoxin down to that of the MoAb. Moreover, the number of internalized immunotoxin molecules was higher than that of unconjugated MoAb. Although a mechanism involving dimerization of the immunotoxin cannot be excluded, our findings suggest that the residual binding activity of the blocked ricin B-chain to cell surface molecules plays an important role in the greater calcium fluxes and greater internalization rate of anti-B4–bR, and is of functional significance in the mechanism of intoxication of cells by the immunotoxin.

Although it has been recognized for sometime that target cells destroyed by natural killer (NK) cells die largely by apoptosis, the underlying mechanisms are not fully understood. The aim of the present study was to examine the role of nitric oxide (NO) in mediating murine NK-cell-induced killing of YAC-1 lymphoma cells. NK calls induced extensive release of 125I-DNA and 51Cr from YAC-1 cells. The target killing ability of NK cells was associated with an increased production of NO as measured by concentrations of nitrite in the culture medium. That YAC-1 killing resulted, in part, from the production of NO was confirmed by the significant protection of cell lysis in L-arginine- depleted medium and by approximately 30 % attenuation of cell lysis and DNA fragmentation by an inhibitor of NO synthase, NG-nitro-L-arginine methyl ester (L-NAME) in a culture medium containing 1 mmol/L L- arginine. Fluorescence microscopic examination of YAC-1 cells showed the presence of changes in nuclear morphology characteristic for apoptosis. The percentage of apoptotic cells was markedly decreased by L-NAME. Further evidence for apoptosis is provided by the specific pattern of internucleosomal DNA fragmentation both in the absence and presence of L-NAME. During target-cell killing, an increased oxidation of intracellularly trapped dichlorofluorescein was observed in cells labeled with an antimouse NK-cell monoclonal antibody, as measured by flow cytometry. These increases were effectively prevented by L-NAME, but not W-13, an inhibitor of calmodulin. The ability of NO to induce cell lysis and DNA fragmentation in YAC-1 cells was further demonstrated by exposing tumor cells to chemically generated NO. Taken together, these observations suggest a role for NO as one of the mediators of NK-cell-mediated DNA fragmentation and cell lysis.

Lachapelle M-H, Miron P, Hemmings R, Baron C, Roy DC. Flow-cytometric characterization of hematopoietic cells in non-pregnant human endometrium. Am J Reprod Immunol 1996; 35:5–13 cP Munksgaard, Copenhagen PROBLEM: Immunologic evaluation and quantitation of hematopoietic cells in human endometrium has been difficult to perform, particularly in nonpregnant subjects. In this study, we describe a method for the flow-cytometric characterization of hematopoietic cells present in the endometrium of non-pregnant women. METHOD: Endometrial biopsy samples from normal donors were first mechanically disrupted and filtered to generate a single-cell suspension of leukocyte-enriched endometrial cells. Cells were labeled with a panel of monoclonal antibodies, stained with propidium iodide (PI), and one- or two-color flow-cytometric analysis performed on cells excluding PI. RESULTS: The methodology described in this study was highly reproducible in experiments evaluating the interrun and intrarun variability. We then determined the immunophenotypic profile of endometrial leukocytes from 12 normal females. The majority of leukocytes were T cells (CD3: 47%; CD4: 24%; CD8: 28%) with an important contingent of NK cells (CD56: 32%), the majority of which harbored the unusual CD16-CD56 bright phenotype, and a minority of B cells (CD20: 6%) and monocytes (CD14: 7%). CONCLUSIONS: Flow cytometry can be used to assess antigen expression on the surface of endometrial leukocytes from nonpregnant women. In future studies, it will be possible to use this approach to investigate the role of immune cell populations in the endometrium of patient experiencing reproductive failure.

Numerous minor histocompatibility antigens (MiHAs) show tissue-specific expression and can induce vigorous T cell responses. They therefore represent attractive targets for leukemia immunotherapy mediated by adoptive transfer of T cells. The main objective of this work was to determine whether MiHAs expressed by normal hematopoietic cells were present on leukemic cells and whether they could trigger lysis by cytotoxic T lymphocytes (CTLs). CTL assays showed that mouse leukemic cells of both lymphoid and myeloid lineages were sensitive to CTLs targeted toward some but not all MiHAs. In four out of four strain combinations in which we primed CTLs against immunodominant MiHAs, effectors killed leukemic blasts, whereas no cytotoxicity was observed when CTLs were targeted toward four immunorecessive MiHAs. Testing of HPLC fractions obtained from normal and leukemic cells provided molecular evidence that leukemic blasts expressed only some of the MiHAs found on normal mouse hematopoietic cells. Decreased density of H-2 class I molecules at the surface of leukemic cells suggests that down-regulation of genes encoding either class I molecules or proteins involved in antigen processing played a role in the aberrant expression of MiHAs. In vivo resistance to the leukemic cells by various strains of mice correlated with in vitro CTL activity. These results show that leukemic cells express only some (immunodominant) MiHAs and suggest that this subset of MiHAs represent prime targets for adoptive immunotherapy.

To assess which measurements best predict improvement on ADHD symptomatology after medication is given.147 children aged 6 to 12 years, diagnosed with ADHD, participated in a double-blind placebo controlled twoweek crossover trial of methylphenidate.There were statistically significant differences on all measures between placebo and medication. Effect size for the overall group was 0.33 (CGI-P), 0.80 (CGI-T), 1.33 (CGI), 0.56 (CPT), 0.82 (RASS).Acute behavioural response measures, where children are observed by clinicians (RASS and CGI), were overall more reliable than parent reports in detecting improvement on ADHD symptomatology. Teacher reports were also very important, especially in the 9 to 12 year old group.

Background: To study the factor structure of the Restricted Academic Situation Scale (RASS), a psychometric tool used to assess behavior in children with ADHD, 117 boys and 21 girls meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria for ADHD and aged between 6 and 12 years were recruited. Assessments were carried out before and 65 min after the administration of either a placebo or 0.25 mg/kg of methylphenidate. Placebo and methylphenidate were each administered according to a double-blind placebo-controlled crossover design. Results: Principal component analysis, followed by a confirmatory maximum likelihood factor analysis, revealed two main factors for the RASS, task disengagement (TD) and motor activation (MA). Only TD was inversely correlated with age, indicating that TD and MA may be differentially modulated during development. Conclusions: MA and TD are distinct traits of ADHD. It may be important to consider them separately when conducting studies on ADHD. (J. of Att. Dis. 2009; 12(5) 442-448)

Background Graft-versus-host disease (GVHD) results from recognition of host antigens by donor T cells following allogeneic hematopoietic cell transplantation (AHCT). Notably, histoincompatibility between donor and recipient is necessary but not sufficient to elicit GVHD. Therefore, we tested the hypothesis that some donors may be “stronger alloresponders” than others, and consequently more likely to elicit GVHD. Methods and Findings To this end, we measured the gene-expression profiles of CD4+ and CD8+ T cells from 50 AHCT donors with microarrays. We report that pre-AHCT gene-expression profiling segregates donors whose recipient suffered from GVHD or not. Using quantitative PCR, established statistical tests, and analysis of multiple independent training-test datasets, we found that for chronic GVHD the “dangerous donor” trait (occurrence of GVHD in the recipient) is under polygenic control and is shaped by the activity of genes that regulate transforming growth factor-β signaling and cell proliferation. Conclusions These findings strongly suggest that the donor gene-expression profile has a dominant influence on the occurrence of GVHD in the recipient. The ability to discriminate strong and weak alloresponders using gene-expression profiling could pave the way to personalized transplantation medicine., The donor gene expression profile appears to have a dominant influence on the occurrence of graft-versus-host disease in the recipient., Editors' Summary Background. Human blood contains red blood cells, white blood cells, and platelets, which carry oxygen throughout the body, fight infections, and help blood clot, respectively. Normally, blood-forming (hematopoietic) stem cells in the bone marrow (and their offspring, peripheral blood stem cells) continually provide new blood cells. Tumors that arise from the bone marrow (such as leukemia and lymphoma, two types of hematopoietic tumor) are often treated by a bone marrow or peripheral blood stem cell transplant from a healthy donor to provide new blood-forming stem cells, as a follow-up to chemotherapy or radiotherapy designed to eradicate as much of the tumor as possible. This procedure is called allogeneic hematopoietic cell transplantation (AHCT)—the word allogeneic indicates that the donor and recipient are not genetically identical. When solid organs (for example, kidneys) are transplanted, the recipient's immune system can recognize alloantigens (proteins that vary between individuals) on the donor organ as foreign and reject it. To reduce the risk of rejection, the donor and recipient must have identical major histocompatibility complex (MHC) proteins. MHC matching is also important in AHCT but for further reasons. Here, donor T lymphocytes (a type of white blood cell) can attack the skin and other tissues of the host. This graft versus host disease (GVHD) affects many people undergoing AHCT despite MHC matching either soon after transplantation (acute GVHD) or months later (chronic GVHD). As an aside, the transplant may also act against the tumor itself—this is known as a graft versus leukemia effect. Why Was This Study Done? GVHD can usually be treated with drugs that damp down the immune system (immunosuppressive drugs), but it would be preferable to avoid GVHD altogether. Indeed, GVHD continues to be the leading cause of nonrelapse mortality following AHCT. Unfortunately, what determines who will develop GVHD after MHC-matched AHCT is unclear. Although GVHD only develops if there are some mismatches in histocompatibility antigens between the donor and host, it does not inevitably develop. Until now, scientists have mainly investigated whether differences between ACHT recipients might explain this observation. But, in this study, the researchers have examined the donors instead to see whether differences in their immune responses might make some donors stronger “alloresponders” than others and consequently more likely to cause GVHD. What Did the Researchers Do and Find? The researchers used a molecular biology technique called microarray expression profiling to examine gene expression patterns in the T lymphocytes of peripheral blood stem cell donors. From these patterns, they identified numerous genes whose expression levels discriminated between donors whose MHC-identical transplant recipient developed GVHD after AHCT (GVHD+ donors) and those whose recipient did not develop GVHD (GVHD− donors). The researchers confirmed that the expression levels of 17 of these genes discriminated between GVHD+ and GVHD− donors using a second technique called quantitative reverse transcriptase polymerase chain reaction. Many of these genes are involved in TGF-β signaling (TGF-β is a protein that helps to control the immune system), cell growth, or proliferation. The researchers also identified four gene pairs that interacted with each other to determine the likelihood that a given donor would induce GVHD. Finally, the researchers computationally retested their data and showed that the measurement of expression levels of each of these genes and of the four interacting gene pairs could correctly identify a donor sample likely to cause GVHD in up to 80% of samples. What Do These Findings Mean? These findings provide the first evidence that the donor's gene expression profile influences the development of GVHD in the recipient after AHCT. The researchers suggest that a “dangerous donor” (strong alloresponder) is a key factor in determining whether GVHD occurs after AHCT and propose that gene expression profiling of donor T lymphocytes might identify those donors likely to cause GVHD. Before this approach can be used to reduce the incidence of GVHD after AHCT, these findings need to be confirmed in many more donors. Also, the development of a test that is accurate enough for clinical use—one that does not miss dangerous donors but does not discard too many safe donors—may require the identification of larger groups of interacting genes. But, if it survives further investigation, the concept of a dangerous donor could represent an important advance in transplantation medicine, one that could help clinicians select low-risk donors for AHCT and tailor patients' immunosuppressive drug regimens according to their donor-determined risk of GVHD. Additional Information. Please access these Web sites via the online version of this summary at http://dx.doi.org/doi:10.1371/journal.pmed.0040023. • The National Marrow Donor Program provides information for patients and physicians on all aspects of hematopoietic stem cell transplantation, including GVHD • The MedlinePlus encyclopedia has pages on bone marrow transplants, GVHD and transplant rejection • The US National Cancer Institute has a factsheet on bone marrow and peripheral blood stem cell transplantation

Genetic and nonshared environmental factors (experienced by 1 family member to the exclusion of the others) have been strongly implicated in the causes of attention-deficit hyperactivity disorder (ADHD). Pregnancy, labour/delivery and neonatal complications (PLDNC) have often been associated with ADHD; however, no investigations aimed at delineating the shared or nonshared nature of these factors have been reported. We aimed to identify those elements of the PLDNC that are more likely to be of a nonshared nature.We used an intrafamily study design, comparing the history of PLDNC between children diagnosed with ADHD, according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), and their unaffected siblings. Children with ADHD were recruited from the outpatient, day-treatment program of the Child Psychiatry Department, Douglas Hospital, Montreal. The unaffected sibling closest in age to the child with ADHD was used as a control. The history of PLDNC was assessed using the Kinney Medical and Gynecological Questionnaire and the McNeil-Sjostrom Scale for both children with ADHD and their siblings. Seventy children with ADHD along with 50 of their unaffected siblings agreed to participate in the study. Child Behavior Checklist (CBCL), Continuous Performance Test (CPT) and Restricted Academic Situation Scale (RASS) scores were also used as measures of ADHD symptoms in children with ADHD.The children with ADHD had significantly higher rates of neonatal complications compared with their unaffected siblings (F4,196 = 3.67, p0.006). Furthermore, neonatal complications in the children with ADHD were associated with worse CBCL total and externalizing scores and with poorer performance on the CPT.These results suggest that neonatal complications are probably a nonshared environmental risk factor that may be pathogenic in children with ADHD.

Many authors have stressed the impact of anxiety on asthma. Kinsman has demonstrated how a "panicky" life-style could interfere with asthma management and even result in an increase in use of medications.1 Similar findings were observed in children at our institution.2,3 Contrary to the concept of a "panicky" patient as used by Kinsman,1 the American Psychiatric Association defines a specific entity called panic state or panic disorder remarkable by its intensity and painfulness as well as in the intense fear of resurgence it provokes in patients. The official criteria of panic disorder in DSM3-R4 in the adult classification are: A) One or more panic attacks (discrete periods of intense fear or discomfort) that were unexpected, ie, did not occur immediately on exposure to a situation that almost always caused anxiety.

Recent evidence indicates that free oxygen radicals, in particular hydroxyl radicals, may act as intracellular second messengers for the induction of IL-8, a potent chemoattractant and activator of neutrophil granulocytes. Here we report that peroxynitrite (ONOO−), formed by a reaction of nitric oxide (NO) with superoxide, mediates IL-8 gene expression and IL-8 production in LPS-stimulated human whole blood. The NO synthase inhibitors aminoguanidine and NG-nitro-l-arginine methyl ester (L-NAME) blocked IL-8 release by ∼90% in response to LPS (1 μg/ml), but did not affect the production of IL-1β or TNF-α. Both aminoguanidine and L-NAME blocked the induction of IL-8 mRNA by LPS. Authentic ONOO− (2.5–80 μM) augmented IL-8 mRNA expression and stimulated IL-8 release in a concentration-dependent manner, whereas the NO-releasing compounds, S-nitroso-N-acetyl-dl-penicillamine and sodium nitroprusside failed to induce cytokine production. Combination of the NO-generating chemicals with a superoxide-generating system (xanthine/xanthine oxidase) markedly increased IL-8 release. Enhanced ONOO− formation was detected in granulocytes, monocytes, lymphocytes, and plasma after challenge with LPS. Furthermore, pyrrolidine dithiocarbamate, an inhibitor of activation of nuclear factor-κB, markedly attenuated the induction of IL-8 mRNA expression and IL-8 release by either LPS or ONOO−. Our study identifies ONOO− as a novel signaling mechanism for IL-8 gene expression and suggests that inhibition of ONOO− formation or scavenging ONOO− may represent a novel therapeutic approach to inhibit IL-8 production that could lead to reduction of neutrophil accumulation and activation.

> L’immunotherapie reposant sur l’usage des lymphocytes T pour traiter le cancer suscite autant d’enthousiasme que de scepticisme. Un tel clivage tient en grande partie aux resultats contradictoires obtenus avec les deux principales approches therapeutiques mises en œuvre. Ainsi, la vaccination contre des antigenes associes aux tumeurs (AAT), appliquee a des sujets porteurs de tumeurs solides (ex : melanome) n’a pas demontre, sauf rarissimes exceptions, d’effets cliniques probants [1, 2]. En revanche, l’injection de lymphocytes T allogeniques diriges contre des antigenes mineurs d’histocompatibilite (AgMiH) s’est averee tres efficace dans le traitement des hemopathies malignes (leucemies surtout) [3, 4]. A priori, trois facteurs pourraient expliquer cette difference : (1) la nature de l’antigene cible (AAT contre AgMiH) ; (2) la methode de traitement (vaccination ou injection de lymphocytes) ; et (3) le type de neoplasie (tumeur solide ou leucemie). De ceci emerge donc la question suivante : serait-il possible d’obtenir contre des tumeurs solides des resultats aussi favorables que contre les leucemies ? Nous avons precedemment etabli que des lymphocytes T CD8 pre-actives et diriges contre l’AgMiH H7a pouvaient guerir des souris leucemiques [5]. Nos travaux recents montrent que les memes lymphocytes permettent aussi d’obtenir des taux de guerison appreciables face au melanome [6]. Fait crucial, dans les deux cas, seules les cellules cancereuses sont attaquees par les lymphocytes antiH7a, et ce malgre l’expression ubiquitaire d’ H7a. Ainsi, des lymphocytes T CD8 pre-actives reconnaissant un seul antigene peuvent eliminer une tumeur solide deja etablie. Nos etudes suggerent que l’elimination de la tumeur se deroule en trois temps : d’abord, a la suite de leur injection chez la souris receveuse, les lymphocytes antiH7a pre-actives s’accumulent preferentiellement au site tumoral de facon antigeneindependante. La surexpression de Vcam-1 par l’endothelium tumoral joue un role primordial dans l’« attraction » des lymphocytes actives. Ces lymphocytes secretent ensuite localement de l’interferon-gamma (IFN-γ) inhibant l’angiogenese tumorale et entrainant l’augmentation de l’expression des molecules du complexe majeur d’histocompatibilite (CMH) sur les cellules neoplasiques. Enfin, les lymphocytes reconnaissant leur antigene secretent des molecules cytotoxiques qui s’attaqueront a la tumeur (Figure 1). L’extravasation dans les tissus non-lymphoides, telle la tumeur, est l’apanage des cellules T effectrices et non des cellules T naives. En effet, les cellules T effectrices ont pour fonction de migrer aux sites presentant une inflammation. Or la croissance tumorale implique une invasion tissulaire et, en consequence, une reaction inflammatoire. Ainsi, la pre-activation des lymphocytes, avant injection au receveur, est essentielle au succes du traitement. De plus, nous avons demontre que les cellules T effecM.C. Meunier, J.S. Delisle, C. Baron : Institut de recherche en immunologie et cancerologie (IRIC), Universite de Montreal, CP 6128, succursale Centre-ville, Montreal (Quebec) H3C 3J7 Canada. C. Perreault : Institut de recherche en immunologie et cancerologie (IRIC)1 et Departement de medecine 2, Universite de Montreal, CP 6128, succursale Centre-ville, Montreal (Quebec) H3C 3J7 Canada. claude.perreault@umontreal.ca

C-Reactive protein (CRP), the classic acute-phase reactant in humans, diminishes accumulation of neutrophils at inflammatory sites. To evaluate the underlying mechanisms, we have studied whether CRP and peptides derived from CRP could affect the first step of neutrophil extravasation, the L-selectin-mediated interaction of neutrophils with endothelial cells. CRP markedly attenuated attachment of human neutrophils to cultured LPS-activated human coronary artery and pulmonary microvascular endothelial cells with apparent IC50 values of 20 and 22 microg/ml, respectively. At similar concentrations, CRP rapidly downregulated the expression of L-selectin on the neutrophil surface, whereas it failed to affect expression of CD11b and CD45 or to induce granule enzyme release. The loss of L-selectin was due to cleavage and shedding of the molecule from the cell surface, as quantitated by the soluble form of L-selectin in cell-free supernatants. The effects of CRP could be prevented by an anti-CRP antiserum and by KD-IX-73-4, which inhibits shedding of L-selectin. Inhibition of adhesion with CRP was additive with function-blocking anti-E-selectin and anti-CD18 antibodies, but was not additive with anti-L-selectin antibody. Neutrophil attachment and L-selectin expression were also diminished by CRP peptides 174-185 and 201-206, but not peptide 77-82, albeit these peptides showed a weaker inhibitory effect than the parent protein. These studies indicate a specific activation-independent action of CRP and CRP peptides 174-185 and 201-206 on expression of L-selectin, and suggest that by attenuating neutrophil adhesion to the endothelium and consequently neutrophil traffic into tissues, native CRP and peptides 174-185 and 201-206 may be major mechanisms to attenuate or limit the inflammatory response.

Because bone marrow (BM) transplantation is used with increasing frequency, it is important to elucidate the mechanisms involved in the establishment of tolerance to host minor histocompatibility antigens (MiHA) in recipients transplanted with T-cell-undepleted marrow grafts. We have previously shown that BM chimeras transplanted across MiHA barriers showed specific unresponsiveness to MiHA expressed on recipient-type concanavalin A blasts. Because expression of many MiHA is tissue-specific, we wanted to determine if chimera T lymphocytes would be tolerant to MiHA expressed by all host tissues and organs. To investigate this issue, we measured in vivo proliferation of lymphoid cells from normal C57BL/10 (B10) mice and (B10-->LP) chimeras in tissues and organs of lethally irradiated syngeneic and allogeneic recipients. Donor B10 cells were either untreated, or depleted with anti-Thy-1.2, anti-CD4, or anti-CD8 antibodies. Transplantation of B10 cells in LP recipients triggered an important T-cell-dependent 125I- dUrd uptake in several organs that involved both CD4+ and CD8+ cells. Using Thy-1-congeneic mice we showed that in long-term chimeras practically all CD4+ and CD8+ T lymphocytes were derived from hematopoietic progenitors and not from mature T cells present in the BM graft. When (B10-->LP) BM chimera cells were injected to secondary recipients, no proliferation was observed in any organ of LP hosts whereas normal proliferation was seen in H-2k allogeneic hosts. Thus, in these BM chimeras, tolerance encompasses MiHA expressed by all organs.

The mutagenic effect of occupational exposure to antineoplastic agents was studied in chemotherapy nurses and pharmacists using the T-lymphocyte clonal assay. A significant increase in mutant frequency was observed compared to controls. However, in the present study, cloning efficiency without selection (CEU) was significantly reduced in exposed personnel raising the possibility of an overestimation of the calculated MF. Changes in lymphocyte populations and clonal potential of T-cells were also observed following exposure. CEU was related to % CD4 cells but CE with selection (CETG) was not. Differences in clonal ability of T-cells under selective and unselective conditions coupled with differential lethal effect of antineoplastic agents on lymphocyte subsets may result in inaccurate estimation of MF.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disease which predisposes to the development of schwannomas, meningiomas, ependymomas, and juvenile cataracts. The NF2 gene (NF2) has recently been isolated and maps to chromosome 22q12 between the loci D22S212 and D22S32. Deletion studies in sporadic and NF2 associated schwannomas and meningiomas, and the presence of inactivating mutations in NF2 in patients suggest that it acts as a tumor suppressor gene. A candidate meningioma gene (MEN) has also been isolated from the same interval. A new highly polymorphic (CA)n marker, D22S268, which maps very near to NF2, has allowed us to identify a kindred with three living affected individuals, where the disease is presumably caused by a large germline deletion. Fluorescence in situ hybridization and pulsed field gel electrophoresis confirm the presence of a 700kb deletion which includes the neurofilament heavy chain subunit gene locus (NEFH), D22S268, NF2 and the putative MEN gene. The absence of meningiomas in this pedigree raises doubts as to the existence of a separate MEN locus in this region. These results support the hypothesis that NF2 results from the inactivation of a tumor suppressor gene on chromosome 22q.

International audience; Following the study on psychomaintenance of asthma by Kinsman, Dirks, and Jones (1977), we adapted the Battery for Asthma Illness Behavior (BAIB) to children. Thirty-four children aged 9.3 to 15.4 years were tested with this modified BAIB. They were scored simultaneously on a semistructured psychological interview. Three groups emerged out of these data: low-, medium-, and high-panic-fear personalities. Patients were also rated with regard to their pulmonary function and clinical status, including medication prescribed. The high-panic-fear personality was significantly associated with a higher intensity of prescribed medication, in particular corticosteroids. These results were independent of spirometric pulmonary measurements. We conclude that doctors may overreact to the exaggerated distress of high-panic-fear patients. Psychotherapy could be of help for this group.

Background An association has been observed between the catechol-O-methyltransferase (COMT) gene, the predominant means of catecholamine catabolism within the prefrontal cortex (PFC), and neuropsychological task performance in healthy and schizophrenic adults. Since several of the cognitive functions typically deficient in children with Attention Deficit Hyperactivity Disorder (ADHD) are mediated by prefrontal dopamine (DA) mechanisms, we investigated the relationship between a functional polymorphism of the COMT gene and neuropsychological task performance in these children. Methods The Val108/158 Met polymorphism of the COMT gene was genotyped in 118 children with ADHD (DSM-IV). The Wisconsin Card Sorting Test (WCST), Tower of London (TOL), and Self-Ordered Pointing Task (SOPT) were employed to evaluate executive functions. Neuropsychological task performance was compared across genotype groups using analysis of variance. Results ADHD children with the Val/Val, Val/Met and Met/Met genotypes were similar with regard to demographic and clinical characteristics. No genotype effects were observed for WCST standardized perseverative error scores [F2,97 = 0.67; p > 0.05], TOL standardized scores [F2,99 = 0.97; p > 0.05], and SOPT error scores [F2,108 = 0.62; p > 0.05]. Conclusions Contrary to the observed association between WCST performance and the Val108/158 Met polymorphism of the COMT gene in both healthy and schizophrenic adults, this polymorphism does not appear to modulate executive functions in children with ADHD.