bluuebunny/crossref_metadata_2025 huggingface dataset:
The nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model of childhood acute lymphoblastic leukemia reveals intrinsic differences in biologic characteristics at diagnosis and relapse
Authors: Lock Richard B. , Liem Natalia , Farnsworth Monica L. , Milross Christopher G. , Xue Chengyuan , Tajbakhsh Mayamin , Haber Michelle , Norris Murray D. , Marshall Glenn M. , Rice Alison M.
Published: October 2002

Acute lymphoblastic leukemia cells from 19 children, including 7 who remain in first complete remission (CR1), were engrafted into nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. High-level infiltration of bone marrow, spleen, and liver was observed, with variable infiltration of other organs. The immunophenotypes of xenografts were essentially unaltered compared with the original patient sample. In addition, sequencing of the entire p53 coding region revealed no mutations in 14 of 14 xenografts (10 from patients at diagnosis and 4 at relapse). Cells harvested from the spleens of engrafted mice readily transferred the leukemia to secondary and tertiary recipients. To correlate biologic characteristics of xenografts with clinical and prognostic features of the patients, the rates at which individual leukemia samples engrafted in NOD/SCID mice were analyzed. Differences in biologic correlates were encountered depending on stage of disease: a direct correlation was observed between the rate of engraftment and length of CR1 for samples harvested at relapse (r = 0.96; P = .002), but not diagnosis (r = 0.38; P = .40). In contrast, the in vivo responses of 6 xenografts to vincristine showed a direct correlation (r = 0.96; P = .002) between the length of CR1 and the rate at which the leukemia cell population recovered following vincristine treatment, regardless of whether the xenografts were derived from patients at diagnosis or relapse. This study supports previous findings that the NOD/SCID model of childhood ALL provides an accurate representation of the human disease and indicates that it may be of value to predict relapse and design alternative treatment strategies in a patient-specific manner.
In vitro susceptibility to dexamethasone- and doxorubicin-induced apoptotic cell death in context of maturation stage, responsiveness to interleukin 7, and early cytoreduction in vivo in childhood T-cell acute lymphoblastic leukemia
Authors: Wuchter Christian , Ruppert Velia , Schrappe Martin , Dörken Bernd , Ludwig Wolf-Dieter , Karawajew Leonid
Published: October 2002

Within childhood T-cell acute lymphoblastic leukemia (T-ALL), patients with a cortical (CD1a+) immunophenotype have been identified as a subgroup with favorable outcome in the acute lymphoblastic leukemia–Berlin-Frankfurt-Münster (ALL-BFM), Cooperative study group for childhood acute lymphoblastic leukemia (COALL) and Pediatric Oncology Group studies. We investigated in leukemic samples of children with T-ALL (n = 81) whether the different in vivo therapy response could be linked to differential in vitro susceptibility to apoptotic cell death. The extent of dexamethasone- as well as doxorubicin-induced apoptosis, detected by annexin V staining, positively correlated with the expression levels of CD1a (Spearman correlation coefficient, rs = 0.3 and 0.4, respectively; P < .01). When compared to cortical T-ALL, mature (CD1a− , surface CD3+) T-ALL were significantly more resistant to doxorubicin, and immature, pro–/pre–T-ALL were more resistant to both drugs (P < .05). Apoptosis-related parameters (Bax, Bcl-2, CD95, and CD95-induced apoptosis) did not account for differential susceptibility to drug-induced apoptosis. By contrast, an interleukin 7–induced rescue of leukemic cells from spontaneous apoptosis, recently proposed to reflect distinct developmental stages and apoptotic programs in T-ALL, was highly associated with susceptibility to dexamethasone- but not doxorubicin-induced apoptosis (P < .001 versus P = .08). Analysis of clinical data showed that in vitro susceptibility to dexamethasone (but not to doxorubicin) closely correlated with early in vivo therapy response characterized by percentages of blast cells in bone marrow on day 15 (rs = −0.46, P = .001). Taken together, the in vitro assessment of drug-induced apoptosis revealed maturation-dependent differences within childhood T-ALL. The enhanced sensitivity to both drugs in cortical T-ALL might account for the better in vivo treatment response of this prognostically favorable T-ALL subgroup.
Neutrophil activation by heme: implications for inflammatory processes
Authors: Graça-Souza Aurélio V. , Arruda Maria Augusta B. , de Freitas Marta S. , Barja-Fidalgo Christina , Oliveira Pedro L.
Published: October 2002

Heme, a ubiquitous iron-containing compound, is present in large amounts in many cells and is inherently dangerous, particularly when it escapes from intracellular sites. The release of heme from damaged cells and tissues is supposed to be higher in diseases such as malaria and hemolytic anemia or in trauma and hemorrhage. We investigated here the role of free ferriprotoporphyrin IX (hemin) as a proinflammatory molecule, with particular attention to its ability to activate neutrophil responses. Injecting hemin into the rat pleural cavity resulted in a dose-dependent migration of neutrophils, indicating that hemin is able to promote the recruitment of these cells in vivo. In vitro, hemin induced human neutrophil chemotaxis and cytoskeleton reorganization, as revealed by the increase of neutrophil actin polymerization. Exposure of human neutrophils to 3 μM hemin activated the expression of the chemokine interleukin-8, as demonstrated by quantitative reverse-transcription polymerase chain reaction, indicating a putative molecular mechanism by which hemin induces chemotaxis in vivo. Brief incubation of human neutrophils with micromolar concentrations of hemin (1-20 μM) triggered the oxidative burst, and the production of reactive oxygen species was directly proportional to the concentration of hemin added to the cells. Finally, we observed that human neutrophil protein kinase C was activated by hemin in vitro, with a K1/2 of 5 μM. Taken together, these results suggest a role for hemin as a proinflammatory agent able to induce polymorphonuclear neutrophil activation in situations of clinical relevance, such as hemolysis or hemoglobinemia.
Insights into the molecular pathogenesis of follicular lymphoma arising from analysis of geographic variation
Authors: Biagi James J. , Seymour John F.
Published: October 2002

Incidence rates of follicular lymphoma (FL) inexplicably vary markedly between Western and Asian countries. A hallmark of FL is thebcl-2 translocation, characterized by 1 of 2 common breakpoints known as major breakpoint region (MBR) and minor cluster region (mcr). We analyzed previously published data to compare rates ofbcl-2 translocation in FL across geographic regions. Available data from the literature suggest that the incidence ofbcl-2 in healthy persons in the absence of FL may be as high as 50% in Western and Asian populations. However, in FL our results show that the frequency of bcl-2 positivity was significantly higher for US than for Asian populations (P < .0001). This pattern persisted for MBR and mcr subgroups. We conclude that a significant gradient exists in thebcl-2 frequency between these FL populations. We therefore suggest that the relatively low incidence of FL in Asian populations is caused not by a lower frequency of bcl-2 rearrangements in healthy populations but by distinct molecular pathways developing in different geographic regions that nonetheless culminate in FL, which is morphologically similar but molecularly distinct. Studies demonstrating differences in clinical characteristics according to the presence or absence of bcl-2 rearrangements support this concept. Thus we hypothesize that FL may in fact be a heterogeneous malignancy encompassing entities with distinct molecular pathogenesis and potentially distinct clinical manifestations. If these findings were confirmed in prospective studies, it would imply that different etiologic or genetic factors might influence the development of FL across separate regions.
Enhancement of intracellular signaling associated with hematopoietic progenitor cell survival in response to SDF-1/CXCL12 in synergy with other cytokines
Authors: Lee Younghee , Gotoh Akihiko , Kwon Hyung-Joo , You Minute , Kohli Lisa , Mantel Charlie , Cooper Scott , Hangoc Giao , Miyazawa Keisuke , Ohyashiki Kazuma , Broxmeyer Hal E.
Published: October 2002

Stromal cell–derived factor 1 (SDF-1/CXCL12) is a multifunctional cytokine. We previously reported that myelopoiesis was enhanced in SDF-1α transgenic mice, probably due in part to SDF-1α enhancement of myeloid progenitor cell (MPC) survival. To understand signaling pathways involved in this activity, we studied the effects on factor-dependent cell line MO7e cells incubated with SDF-1α alone or in combination with other cytokines. SDF-1α induced transient activation of extracellular stress–regulated kinase (ERK1/2), ribosomal S6 kinase (p90RSK) and Akt, molecules implicated in cell survival. Moreover, ERK1/2, p90RSK, and Akt were synergistically activated by SDF-1α in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), Steel factor (SLF), or thrombopoietin (TPO). Similar effects were seen after pretreatment of MO7e cells with SDF-1α followed by stimulation with the other cytokines, suggesting a priming effect of SDF-1α. Nuclear factor-κB (NF-κB) did not appear to be involved in SDF-1α actions, alone or in combination with other cytokines. These intracellular effects were consistent with enhanced myeloid progenitor cell survival by SDF-1α after delayed addition of growth factors. SDF-1α alone supported survival of highly purified human cord blood CD34+++ cells, less purified human cord blood, and MO7e cells; this effect was synergistically enhanced when SDF-1α was combined with low amounts of other survival-promoting cytokines (GM-CSF, SLF, TPO, and FL). SDF-1 may contribute to maintenance of MPCs in bone marrow by enhancing cell survival alone and in combination with other cytokines.
Ibritumomab tiuxetan radioimmunotherapy for patients with relapsed or refractory non-Hodgkin lymphoma and mild thrombocytopenia: a phase II multicenter trial
Authors: Wiseman Gregory A. , Gordon Leo I. , Multani Pratik S. , Witzig Thomas E. , Spies Stewart , Bartlett Nancy L. , Schilder Russell J. , Murray James L. , Saleh Mansoor , Allen Roberta S. , Grillo-López Antonio J. , White Christine A.
Published: October 2002

Mildly thrombocytopenic patients with relapsed or refractory low-grade non-Hodgkin lymphoma (NHL) have an increased risk of chemotherapy-induced myelosuppression following treatment. The safety and efficacy of radioimmunotherapy with a reduced dose of90Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]; maximum 32 mCi [1.2 GBq]) was evaluated in 30 patients with mild thrombocytopenia (100-149 × 109 platelets/L) who had advanced, relapsed or refractory, low-grade, follicular, or transformed B-cell NHL. The ibritumomab tiuxetan regimen included an infusion of rituximab (250 mg/m2) and injection of 111In ibritumomab tiuxetan (5 mCi [185 MBq]) for dosimetry evaluation, followed 1 week later with rituximab (250 mg/m2) and90Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]). Patients (median age, 61 years; 90% stage III/IV at study entry; 83% follicular lymphoma; and 67% with bone marrow involvement) had a median of 2 prior therapy regimens (range, 1-9). Estimated radiation-absorbed doses were well below the study-defined maximum allowable for all 30 patients. With the use of the International Workshop criteria for NHL response assessment, the overall response rate was 83% (37% complete response, 6.7% complete response unconfirmed, and 40% partial response). Kaplan-Meier estimated median time to progression (TTP) was 9.4 months (range, 1.7-24.6). In responders, Kaplan-Meier estimated median TTP was 12.6 months (range, 4.9-24.6), with 35% of data censored. Toxicity was primarily hematologic, transient, and reversible. The incidence of grade 4 neutropenia, thrombocytopenia, and anemia was 33%, 13%, and 3%, respectively. Reduced-dose ibritumomab tiuxetan is safe and well tolerated and has significant clinical activity in this patient population.
Prevention of Epstein-Barr virus–lymphoproliferative disease by molecular monitoring and preemptive rituximab in high-risk patients after allogeneic stem cell transplantation
Authors: van Esser Joost W. J. , Niesters Hubert G. M. , van der Holt Bronno , Meijer Ellen , Osterhaus Albert D. M. E. , Gratama Jan Willem , Verdonck Leo F. , Löwenberg Bob , Cornelissen Jan J.
Published: October 2002

Recipients of a partially T-cell–depleted (TCD) allogeneic stem cell transplantation (allo-SCT) developing reactivation of Epstein-Barr virus (EBV) with quantified viral DNA levels exceeding 1000 genome equivalents/milliliter (geq/mL) are at high risk for EBV–lymphoproliferative disease (EBV-LPD). We studied whether preemptive therapy with rituximab prevents EBV-LPD, LPD-mortality, and abrogates viral reactivation in high-risk patients. We monitored 49 recipients of a TCD allo-SCT weekly for EBV reactivation by quantitative real-time polymerase chain reaction (PCR). Preemptive therapy by a single infusion of rituximab was given to patients with viral reactivation more than or equal to 1000 geq/mL. Results were compared with an historical control group of patients retrospectively monitored for EBV reactivation at similar intervals. There were 17 prospectively monitored patients who showed EBV reactivation more than or equal to 1000 geq/mL and 15 received preemptive therapy. Median time to preemptive therapy was 113 days (range, 41-202 days) after SCT. There were 14 patients who showed complete response (CR) as characterized by prevention of EBV-LPD and complete clearance of EBV-DNA from plasma, which was achieved after a median number of 8 days (range, 1-46 days). One patient progressed to EBV-LPD despite pre-emptive therapy, but obtained CR after 2 infusions of rituximab and donor lymphocyte infusion. There were 2 patients who had already developed EBV-LPD prior to preemptive rituximab, but obtained CR following 2 rituximab infusions. Comparison of this prospectively followed series to our historical cohort with the same high-risk profile showed a reduction of EBV-LPD incidence (18% ± 9% versus 49% ± 11%, respectively) and a complete abrogation of LPD-mortality (0% versus 26% ± 10%, respectively) (P = .04) at 6 months from EBV-DNA more than or equal to 1000 geq/mL. Frequent quantitative monitoring of EBV reactivation and preemptive therapy by rituximab improves outcome in patients at high risk of EBV-LPD.
A new platelet polymorphism Duva+, localized within the RGD binding domain of glycoprotein IIIa, is associated with neonatal thrombocytopenia
Authors: Jallu Vincent , Meunier Marc , Brément Maryline , Kaplan Cécile
Published: October 2002

We report here the identification and characterization of a new platelet alloantigen, Duva+, implicated in a case of neonatal thrombocytopenia. Immunochemical studies demonstrated that the epitope was localized on glycoprotein (GP) IIIa. Sequencing of the exons 2 to 15 of GP IIIa gene polymerase chain reaction products from both parents revealed a single base substitution 517C>T (complementary DNA) present in a heterozygous state in DNA from the father leading to amino acid substitution Thr140Ile (ACC>ATC) within the Arg-Gly-Asp binding domain of GP IIIa. Flow cytometry and immunoprecipitation studies of IIb-C517 or T517 IIIa transfected Cos cells allowed us to demonstrate this mutation was responsible for expression of the Duva+epitope. By polymerase chain reaction–single-strand conformational-polymorphism analysis, the mutated allele could not be detected in a population of 100 healthy unrelated donors, indicating a low frequency of occurrence. The Thr140/Ile dimorphism, localized 3 amino acids upstream from the Arg143 involved in the expression of HPA-4a, did not interfere with the binding of an anti–HPA-4a antibody in flow cytometry. Results of functional analysis of wild-type or mutated transfected CHO cells—(1) aggregation in the presence of Ca++ and soluble fibrinogen after complex activation by dithiothreitol, (2) adhesion on coated fibrinogen, (3) binding of monoclonal antibody PAC-1 or LIBS antibody D3, and (4) outside-in signaling—all suggest that the Thr140Ile polymorphism localized in the Arg-Gly-Asp binding domain of GP IIIa does not affect significantly, if at all, the integrin function. We have shown that the anti-Duva+ antibody may inhibit platelet GP IIb-IIIa function.
Apoptotic signaling induced by immunomodulatory thalidomide analogs in human multiple myeloma cells: therapeutic implications
Authors: Mitsiades Nicholas , Mitsiades Constantine S. , Poulaki Vassiliki , Chauhan Dharminder , Richardson Paul G. , Hideshima Teru , Munshi Nikhil C. , Treon Steven P. , Anderson Kenneth C.
Published: October 2002

Thalidomide (Thal) achieves responses even in the setting of refractory multiple myeloma (MM). Although increased angiogenesis in MM bone marrow and the antiangiogenic effect of Thal formed the empiric basis for its use in MM, we have shown that Thal and its immunomodulatory analogs (IMiDs) directly induce apoptosis or growth arrest of MM cells, alter adhesion of MM cells to bone marrow stromal cells, inhibit the production of cytokines (interleukin-6 and vascular endothelial growth factor) in bone marrow, and stimulate natural killer cell anti-MM immunity. In the present study, we demonstrate that the IMiDs trigger activation of caspase-8, enhance MM cell sensitivity to Fas-induced apoptosis, and down-regulate nuclear factor (NF)-κB activity as well as expression of cellular inhibitor of apoptosis protein–2 and FLICE inhibitory protein. IMiDs also block the stimulatory effect of insulinlike growth factor–1 on NF-κB activity and potentiate the activity of TNF-related apoptosis-inducing ligand (TRAIL/Apo2L), dexamethasone, and proteasome inhibitor (PS-341) therapy. These studies both delineate the mechanism of action of IMiDs against MM cells in vitro and form the basis for clinical trials of these agents, alone and coupled with conventional and other novel therapies, to improve outcome in MM.
Expression levels of apoptosis-related proteins predict clinical outcome in anaplastic large cell lymphoma
Authors: ten Berge Rosita L. , Meijer Chris J. L. M. , Dukers Danny F. , Kummer J. Alain , Bladergroen Bellinda A. , Vos Wim , Hack C. Erik , Ossenkoppele Gert J. , Oudejans Joost J.
Published: October 2002

In vitro studies suggest that resistance to chemotherapy-induced apoptosis might explain poor response to therapy in fatal cases. Actual execution of apoptosis depends on proper functioning of effector caspases, particularly caspase 3, and on the expression levels of apoptosis-regulating proteins, including Bcl-2 and the recently identified granzyme B– specific protease inhibitor 9 (PI9). Thus, high levels of caspase 3 activation should reflect proper functioning of the apoptosis pathways, resulting in chemotherapy-sensitive neoplastic cells and a favorable prognosis. We tested this hypothesis by quantifying numbers of tumor cells positive for active caspase 3, Bcl-2, and PI9, respectively, in pretreatment biopsies of systemic anaplastic large cell lymphoma (ALCL) patients and by comparing these numbers with clinical outcome. Activation of caspase 3 in more than 5% of the tumor cells was strongly correlated with a highly favorable outcome. High numbers of Bcl-2– and PI9-positive tumor cells were found to predict unfavorable prognosis. This prognostic effect was strongly related to anaplastic lymphoma kinase (ALK) status: ALK-positive ALCL had significantly higher levels of active caspase 3, while high expression of the antiapoptotic proteins Bcl-2 and PI9 was almost completely restricted to ALK-negative cases. In conclusion, high numbers of active caspase 3–positive tumor cells predict a highly favorable prognosis in systemic ALCL patients. Poor prognosis is strongly related to high numbers of Bcl-2– and PI9-positive neoplastic cells. These data support the notion that a favorable response to chemotherapy depends on an intact apoptosis cascade. Moreover, these data indicate that differences in prognosis between ALK-positive and ALK-negative ALCL might be explained by differences in expression of apoptosis-inhibiting proteins.
Derivative chromosome 9 deletions in chronic myeloid leukemia: poor prognosis is not associated with loss of ABL-BCRexpression, elevated BCR-ABL levels, or karyotypic instability
Authors: Huntly Brian J. P. , Bench Anthony J. , Delabesse Eric , Reid Alistair G. , Li Juan , Scott Mike A. , Campbell Lynda , Byrne Jennie , Pinto Eleanor , Brizard Andre , Niedermeiser Deitger , Nacheva Elizabeth P. , Guilhot Francois , Deininger Michael , Green Anthony R.
Published: October 2002

Deletions of the derivative chromosome 9 have recently been reported in chronic myeloid leukemia. These deletions are large, occur at the time of the Philadelphia (Ph) translocation, span the translocation breakpoint, and represent a powerful prognostic indicator. However, the molecular mechanisms responsible for the poor prognosis associated with deletions are obscure, and several possible models are investigated here. First, we demonstrate that all derivative chromosome 9 deletions detected by fluorescence in situ hybridization were associated with an absence ofABL-BCR expression. However, loss ofABL-BCR expression also occurred without an overt deletion, suggesting the existence of other mechanisms by whichABL-BCR transcription can be abolished. Furthermore, analysis of survival in 160 patients demonstrated that loss ofABL-BCR expression, in contrast to deletion status, was not an indicator of poor prognosis. Second, we addressed the possibility that concomitant small deletions of the Ph chromosome modulateBCR-ABL transcription. Real-time reverse-transcription polymerase chain reaction was used to demonstrate that derivative chromosome 9 deletions were not accompanied by altered levels of BCR-ABL transcripts. Third, deletions may represent a consequence of genetic instability within the target cell at the time of the Ph translocation, with the poor prognosis reflecting a predisposition to subsequent additional genetic alterations. However, patients with deletions do not exhibit an increased frequency of secondary cytogenetic changes following disease progression. Taken together, these data support a model in which deletions of the derivative chromosome 9 result in rapid disease progression as a result of the loss of one or more genes within the deleted region.
Tolerance induction of alloreactive T cells via ex vivo blockade of the CD40:CD40L costimulatory pathway results in the generation of a potent immune regulatory cell
Authors: Taylor Patricia A. , Friedman Thea M. , Korngold Robert , Noelle Randolph J. , Blazar Bruce R.
Published: October 2002

We previously reported that ex vivo blockade of the CD40:CD40L costimulatory pathway in primary mixed lymphocyte reaction cultures resulted in profound in vitro secondary hyporesponsiveness and 30-fold or greater protection from graft-versus-host-disease (GVHD) lethality. Present studies demonstrate that tolerance induction via costimulatory blockade also results in the generation of a potent immunoregulatory cell that inhibits both naive and primed alloresponses. The immunoregulatory capacity was dependent upon cell-to-cell contact that prevented the full activation of the naive or primed cells. The inhibitory effect of tolerized cells did not preclude the response of naive T cells to nominal protein antigen if antigen was present at high concentration. However, under suboptimal antigen concentration, nonspecific inhibition of responses occurred. The tolerized regulatory cell population maintained a polyclonal T-cell receptor Vβ repertoire that was broader than in control primed cultures. These data, the first to demonstrate that tolerance induction via CD40:CD40L costimulatory blockade results in potent regulatory function, are relevant to bone-marrow and solid-organ transplantation. The generation of potent immunoregulatory capacity during tolerization via CD40:CD40L blockade provides a fail-safe mechanism to control alloreactive T cells that may have escaped tolerization. These potent regulatory cells may be clinically exploitable for the treatment and prevention of GVHD or autoimmunity.
Quantitative assessment of hematopoietic chimerism after bone marrow transplantation by real-time quantitative polymerase chain reaction
Authors: Alizadeh Mehdi , Bernard Marc , Danic Bruno , Dauriac Charly , Birebent Brigitte , Lapart Christine , Lamy Thierry , Le Prisé Pierre-Yves , Beauplet Alain , Bories Dominique , Semana Gilbert , Quelvennec Erwann
Published: October 2002

We have developed a real-time quantitative polymerase chain reaction (PCR) assay using TaqMan technology (Applied Biosystems, Foster City, CA) for monitoring donor cell engraftment in allogenic hematopoietic stem cell transplant recipients. For this purpose, we selected 19 specific sequence polymorphisms belonging to 11 human biallelic loci located on 9 different chromosomes. Using a set of specially designed primers and fluorogenic probes, we evaluated the 19 markers' informativity on a panel of 126 DNA samples from 63 recipient/donor pairs. In more than 90% of these pairs, discrimination between recipient and donor genetic profile was possible. By using serial dilutions of mixed DNAs, we evaluated the linearity and sensitivity of the method. A linear correlation with rhigher than 0.98 and a sensitivity of 0.1% proved reproducible. Fluorescent-based PCR of short tandem repeats (STR-PCR) and real-time PCR chimerism assay were compared with a panel of artificial cell mixtures. The main advantage of the real-time PCR method over STR-PCR chimerism assays is the absence of PCR competition and plateau biases, and results evidenced greater sensitivity and linearity with the real-time PCR method. Furthermore, different samples can be tested in the same PCR run with a final result in fewer than 48 hours. Finally, we prospectively analyzed patients who received allografts and present 4 different clinical situations that illustrate the informativity level of our method. In conclusion, this new assay provides an accurate quantitative assessment of mixed chimerism that can be useful in guiding early implementation of additional treatments in hematopoietic stem cell transplantation.
Incidence of venous thromboembolism in asymptomatic family members who are carriers of factor V Leiden: a prospective cohort study
Authors: Simioni Paolo , Tormene Daniela , Prandoni Paolo , Zerbinati Patrizia , Gavasso Sabrina , Cefalo Philip , Girolami Antonio
Published: October 2002

In a prospective cohort study, we assessed the incidence of spontaneous and risk period–related venous thromboembolism (VTE) in asymptomatic family members of patients who experienced VTE and had the factor V Leiden mutation. In all, 561 family members of 131 probands were included, 313 of whom were carriers (299 heterozygous and 14 homozygous) and 248 of whom were noncarriers of the factor V Leiden mutation. Average follow-up was 4 years (range, 4 months-6 years). There were 1255 and 984 observation-years of follow-up in carriers and noncarriers, respectively. Eight episodes of VTE occurred in heterozygous carriers, resulting in an annual incidence of 0.67% (95% confidence interval [CI], 0.29-1.33). Two events occurred in the absence of associated risk factors, determining an annual incidence of spontaneous VTE of 0.17% (95% CI, 0.02-0.6). Only one VTE (risk period–related) occurred in noncarriers, with an annual incidence of 0.1% (95% CI, 0.003-0.56). Relative risk for VTE in heterozygous carriers compared with noncarriers of the factor V Leiden mutation was 6.6 (95% CI, 1.1-39.8). Risk period–related VTE occurred with an incidence of 18% and 5% per risk period in heterozygous carriers and in noncarriers, respectively. Thus, the low rate of VTE in asymptomatic family members carrying the mutation did not justify continuous anticoagulant prophylaxis. Screening families of symptomatic probands with the factor V Leiden mutation has the potential to identify those asymptomatic carriers who might benefit from thromboprophylaxis during risk periods.
Clinicopathologic analysis of follicular lymphoma occurring in children
Authors: Lorsbach Robert B. , Shay-Seymore Dominic , Moore Jennifer , Banks Peter M. , Hasserjian Robert P. , Sandlund John T. , Behm Frederick G.
Published: October 2002

Follicular lymphoma is a rare lymphoid malignancy in pediatric patients and consequently remains poorly characterized, particularly with respect to its immunophenotype and molecular pathogenesis. A total of 23 pediatric patients with follicular lymphoma were identified, with a median age of 11 years and a male-to-female ratio of 2.3:1. Of the 19 patients for whom presenting clinical features were available, 15 patients had stage I, 1 had stage II, and 3 had stage III or IV disease. All tumors had a follicular architecture, and 74% of cases had grade 2 or 3 histologic features. All patients expressed CD20 and bcl-6, and 80% were positive for CD10. Bcl-2 expression was detected in only 5 of 16 cases. Consistent with this finding, bcl-2 gene rearrangements were detected in only 2 of 16 cases by polymerase chain reaction. These patients were treated primarily with cyclophosphamide, doxorubicin, vincristine, and prednisone–based chemotherapy; 4 patients also received involved-field irradiation. Of the 13 patients with available clinical follow-up, all but 2 achieved durable clinical remission. Importantly, all 4 patients with tumors diffusely positive for bcl-2 either presented with stage III/IV disease or had disease refractory to therapy, whereas patients with bcl-2–negative tumors uniformly had stage I disease, achieved complete remission, and experienced no relapses. These findings indicate that, in contrast to adult follicular lymphomas, dysregulated bcl-2 expression does not play a significant pathogenetic role in most pediatric follicular lymphomas. However, bcl-2 expression in pediatric follicular lymphoma identifies a subset of patients in whom disease is often disseminated at clinical presentation and is more refractory to combination chemotherapy.
Increased binding and defective migration across fibronectin of cycling hematopoietic progenitor cells
Authors: Giet Olivier , Van Bockstaele Dirk R. , Di Stefano Ivano , Huygen Sandra , Greimers Roland , Beguin Yves , Gothot André
Published: October 2002

Engraftment of hematopoietic progenitor cells has been shown to decrease during cell cycle transit. We studied cell cycle–associated changes in adhesion and migration of mitotically activated cord blood CD34+ cells. Migration toward medium conditioned by the stromal-derived factor-1–producing cell line MS-5 was studied in bovine serum albumin– and fibronectin (Fn)–coated transwells. Migration was reduced in cycling CD34+ cells and long-term culture-initiating cells (LTC-ICs) compared with their noncycling counterparts across Fn but not across bovine serum albumin. Conversely, Fn binding was higher in cycling CD34+ cells and LTC-ICs compared with noncycling progenitor cells, while adhesion of both subsets to bovine serum albumin was undetectable. The contribution of α4 and α5 integrins in mediating adhesion and migration of activated CD34+ cells onto Fn was analyzed by neutralization experiments. While α4-mediated Fn binding decreased during G2/M, α5 integrin–mediated adhesion increased during transit from G0/G1 to S and G2/M phases. As for migration, the contribution of α4 integrin was similar in all phases, whereas α5-directed migration was lower in G2/M compared with G0/G1and S phases. Defective migration of cycling CD34+ cells was not due to differences in α5 integrin expression. In conclusion, chemotaxis across Fn is less efficient in cycling progenitor cells in correlation with an increased Fn binding capacity. In addition, α4 and α5 integrin functions are independently modulated during cell cycle transit.
Long-lasting memory-resting and memory-effector CD4+T cells in human X-linked agammaglobulinemia
Authors: Paroli Marino , Accapezzato Daniele , Francavilla Vittorio , Insalaco Antonella , Plebani Alessandro , Balsano Francesco , Barnaba Vincenzo
Published: October 2002

Conflicting results obtained from animal studies suggest that B cells play a role in maintaining long-term T-cell memory and in skewing T-cell response toward a T-helper 2 (TH2) phenotype. X-linked agammaglobulinemia (XLA) is a genetic human disease characterized by the lack of circulating B cells due to the mutation of Bruton tyrosine kinase. This disease thus represents a unique model for studying the role of B lymphocytes in regulating T-cell functions in humans. To this aim, we analyzed hepatitis B envelope antigen (HBenvAg)–specific T-cell memory in a series of XLA patients vaccinated against hepatitis B virus (HBV). We found HBenvAg-specific T lymphocytes producing interferon–γ, interleukin-4, or both in the peripheral blood of XLA patients up to at least 24 months after completing the standard anti-HBV immunization protocol. The HBenvAg-specific T-cell frequencies and the percentage of patients with these responses were not significantly different from healthy vaccinated controls. By combining cell purification and enzyme-linked immunospot assay, we found that effector CD27− T cells, which promptly produced cytokines in response to antigen (Ag), and memory-resting CD27+ T cells, which required Ag restimulation to perform their functions, were maintained in both XLA patients and controls for up to 24 months after the last vaccination boost. These data strongly suggest that B cells are not an absolute requirement for the generation of effective T-cell memory in humans, nor do they seem to influence TH1/TH2 balance.
Requirements of src family kinase activity associated with CD45 for myeloma cell proliferation by interleukin-6
Authors: Ishikawa Hideaki , Tsuyama Naohiro , Abroun Saeid , Liu Shangqin , Li Fu-Jun , Taniguchi Osamu , Kawano Michio M.
Published: October 2002

Specific intracellular signals mediated by interleukin-6 (IL-6) receptor complexes, such as signal transducer and activator of transcription 3 (STAT 3) and extracellular signal–regulated kinase (ERK) 1/2, are considered to be responsible for inducing a variety of cellular responses. In multiple myeloma, IL-6 only enhanced the proliferation of CD45+ tumor cells that harbored the IL-6–independent activation of src family kinases even though STAT3 and ERK1/2 could be activated in response to IL-6 in both CD45+ and CD45− cells. Furthermore, the IL-6–induced proliferation of CD45+ U266 myeloma cells was significantly suppressed by Lyn-specific antisense oligodeoxynucleotides or a selective src kinase inhibitor. These results indicate that the activation of both STAT3 and ERK1/2 is not enough for IL-6–induced proliferation of myeloma cell lines that require src family kinase activation independent of IL-6 stimulation. Thus, the activation of the src family kinases associated with CD45 expression is a prerequisite for the proliferation of myeloma cell lines by IL-6. We propose a mechanism for IL-6–induced cell proliferation that is strictly dependent upon the cellular context in myelomas.
Clinical aspects of exhaled nitric oxide
Authors: Kharitonov SA , Barnes PJ
Published: October 2002

There has been intense research into the role nitric oxide (NO) plays in physiological and pathological mechanisms and its clinical significance in respiratory medicine. Elevated levels of exhaled levels of exhaled NO in asthma and other inflammatory lung diseases lead to many studies examining NO as potential markers of airway inflammation, enabling repeated noninvasive and standardized monitoring of airway inflammation. In airway inflammation, NO is not merely a marker but may have anti-inflammatory and pro-inflammatory effects. Significant correlation has been found between exhaled NO and skin test scores in steroid naive asthmatic patients, allowing to discriminate patients with and without airway responsiveness. Exhaled NO is significantly elevated in acute asthma, or steroid-resistant severe asthma, or when the maintenance dose of inhaled steroids is reduced, and quickly reduced down to the levels in patients with stable asthma after steroid treatment. Exhaled NO has been successfully used to monitor anti-inflammatory treatment with inhaled corticosteroids in asthma. Exhaled NO is extremely sensitive and rapid marker of the dose-dependent effect of steroid treatment, or asthma deterioration, which is increased to any changes in lung function, provocative concentration causing a 20% fall in forced expiratory volume, sputum eosinophilia or asthma symptoms. Exhaled NO is not increased in stable chronic obstructive pulmonary disease (COPD), but patients with unstable COPD, or bronchiectasis have high NO levels. Exhaled and nasal NO are diagnostically low in cystic fibrosis and primary pulmonary dyskinesia. Analysis of exhaled air, including nitric oxide, is feasible and could provide a noninvasive method for use in monitoring and management of lung diseases.
Nasal peak inspiratory flow at altitude
Authors: Barry P.W. , Mason N.P. , Richalet J-P.
Published: October 2002

The present study investigated whether there are changes in nasal peak inspiratory flow (NPIF) during hypobaric hypoxia under controlled environmental conditions.

During operation Everest III (COMEX '97), eight subjects ascended to a simulated altitude of 8,848 m in a hypobaric chamber. NPIF was recorded at simulated altitudes of 0 m, 5,000 m and 8,000 m. Oral peak inspiratory and expiratory flow (OPIF, OPEF) were also measured. Ambient air temperature and humidity were controlled.

NPIF increased by a mean±sd of 16±12% from sea level to 8,000 m, whereas OPIF increased by 47±14%. NPIF rose by 0.085±0.03 L·s−1per kilometre of ascent (p<0.05), significantly less than the rise in OPIF and OPEF of 0.35±0.10 and 0.33±0.04 L·s−1per kilometre (p<0.0005).

Nasal peak inspiratory flow rises with ascent to altitude. The rise in nasal peak inspiratory flow with altitude was far less than oral peak inspiratory flow and less than the predicted rise according to changes in air density. This suggests flow limitation at the nose, and occurs under controlled environmental conditions, refuting the hypothesis that nasal blockage at altitude is due to the inhalation of cold, dry air. Further work is needed to determine if nasal blockage limits activity at altitude.
Occupational asthma in France: a 1-yr report of the Observatoire National de Asthmes Professionnels project
Authors: Kopferschmitt-Kubler M.C. , Ameille J. , Popin E. , Calastreng-Crinquand A. , Vervloet D. , Bayeux-Dunglas M.C. , Pauli G. ,   members of Observatoire National de Asthmes Professionnels Group
Published: October 2002

Observatoire National des Asthmes Professionnels (ONAP) was created in 1996 by two French professional societies to estimate the incidence of occupational asthma and to promote preventive measures against it.

Occupational and chest physicians were asked to report newly diagnosed cases of work-related asthma and reactive airway dysfunction syndrome (RADS), the information collected included age, sex, occupation, suspected causal agents and diagnostic methods.

In 1997, 82.3% of 559 cases reported (64% males, mean age 36±13 yrs) involved occupational asthma, 4.7% RADS and 12.7% atypical asthma syndromes. Incidence rates (expressed as number of cases per million workers) showed a regional variation that ranged from 4 to 73 (national mean: 25.7). The most frequently suspected agents were flour (23.3%), followed by isocyanates (16.6%), latex (7.5%), aldehydes (5.5%), and persulphates (4.1%). Occupations at risk were bakers (23.9%), healthcare workers (12%), painters (9.1%), hairdressers (5.2%), wood industry workers (4.8%) and cleaners (3.5%). These results are compared to those of other systems set up in Europe and North America.

Because of the considerable bias inherent in a surveillance system based on voluntary, reporting, the number of occupational asthma cases reported is probably lower than the real incidence. Nevertheless, the French National Observatory for Occupational Asthma encourages physician awareness of occupational asthma and provides an estimate of its incidence and aetiologies in France.
Evaluation of alveolar surfactant aggregatesin vitroandin vivo
Authors: Brackenbury A.M. , Malloy J.L. , McCaig L.A. , Yao L-J. , Veldhuizen R.A.W. , Lewis J.F.
Published: October 2002

In acute lung injury, a decrease in surface-active large aggregates and an increase in the less surface-active small surfactant aggregates are observed. The objective of the current study was to determine if the increase in small aggregates interfered with the function of large aggregates, thereby independently contributing to lung dysfunction.

Isolated large aggregates, small aggregates, and large aggregate+small aggregate combinations were analysed forin vitrosurface activity utilizing a pulsating bubble surfactometer. Subsequently, large aggregates, small aggregates, and large aggregate+small aggregate combinations were administered to surfactant-deficient, adult Sprague-Dawley rats. Physiological parameters were measured during 1 h of ventilation. After sacrifice, the whole lung lavage was analysed for protein concentration, and surface activity of the recovered large aggregates.

The minimum surface tension of the large aggregate+small aggregate preparations (10 mN·m−1) was significantly higher than large aggregates alone (1 mN·m−1), but lower than small aggregates alone (21 mN·m−1) after 100 pulsations.In vivo, rats receiving large aggregates+small aggregates showed immediate increases in oxygenation, similar to animals given large aggregates, whereas animals given small aggregates and control animals maintained low oxygenation values.

In conclusion, small aggregates interfered with large aggregates functionin vitro, but this was not observedin vivoin this experimental model.
Effect of hypobaric hypoxia on blood gases in patients with restrictive lung disease
Authors: Christensen C.C. , Ryg M.S. , Kåre Refvem O. , Henning Skjønsberg O.
Published: October 2002

Several publications have reported effects of hypobaric conditions in patients with chronic obstructive pulmonary disease. To the current authors' knowledge, similar studies concerning patients with restrictive lung disease have not been published.

The effect of simulated air travel in a hypobaric chamber on arterial blood gases, blood pressure, and cardiac frequency during rest and 20 W exercise, and the response to supplementary oxygen in 17 patients with chronic restrictive ventilatory impairment has been investigated.

Resting oxygen tension in arterial blood (Pa,O2) decreased from 10.4±1.6 kPa at sea level to 6.5±1.1 kPa at 2,438 m simulated altitude, and decreased further during light exercise in all patients (5.1±0.9 kPa).Pa,O2at this altitude correlated positively with sea-levelPa,O2and transfer factor of the lung for carbon monoxide (TL,CO), and negatively with carbon dioxide tension in arterial blood (Pa,CO2).Pa,O2increased to acceptable levels with an O2supply of 2 L·min−1at rest and 4 L·min−1during 20 W exercise.

In conclusion, most of the patients with restrictive ventilatory impairment developed hypoxaemia below the recommended levels of in-flight oxygen tension in arterial blood during simulated air travel. Light exercise aggravated the hypoxaemia. Acceptable levels of oxygen tension in arterial blood, with only a minor increase in carbon dioxide tension in arterial blood, were obtained by supplementary oxygen.
Neutrophil degranulation and cell lysis is associated with clinical severity in virus-induced asthma
Authors: Wark P.A.B. , Johnston S.L. , Moric I. , Simpson J.L. , Hensley M.J. , Gibson P.G.
Published: October 2002

Acute exacerbations of asthma are frequently caused by viral infections, but the inflammatory mechanisms in virus-induced asthma are poorly understood. The aim of the present study was to determine whether viral infection in acute asthma was associated with increased sputum neutrophil degranulation and increased cellular lysis and whether these changes are related to clinical severity.

Adults (n=49) presenting to the emergency department with acute asthma were examined for infection by means of sputum direct-fluorescence antigen detection, sputum culture, and sputum polymerase chain reaction for Mycoplasma, Chlamydia andLegionella pneumophila, and all common respiratory viruses. Subjects infected with one of these agents were classed as having an infective exacerbation. Spirometry and sputum induction were performed on presentation and 4–5 weeks later.

Thirty-seven subjects (76%) had virus infection and acute asthma. Those with virus infection had increased sputum neutrophils (p<0.05) and increased neutrophil elastase (p<0.05), this was related to increased elevated sputum lactate dehydrogenase (LDH). Subjects with noninfective asthma had an increase in the proportion of sputum eosinophils. Both groups had elevated sputum eosinophil cationic protein (ECP) concentrations. Higher levels of sputum LDH and ECP were associated with a longer hospital stay.

Virus infection and acute asthma is associated with neutrophilic inflammation, cell lysis and more severe clinical disease.
Host determinants for the development of allergy in apprentices exposed to laboratory animals
Authors: Gautrin D. , Ghezzo H. , Infante-Rivard C. , Malo J-L.
Published: October 2002

The aim of this study was to evaluate whether determinants of work-related symptoms, skin sensitization and diseases differ between atopic and nonatopic subjects starting a career with exposure to laboratory animals (LA).

A cohort of 417 apprentices in animal-health technology was prospectively followed during 32 or 44 months. The effect on the study outcomes of variables derived from questionnaire, skin reactivity, and lung function assessments at baseline were compared in atopic (n=212) and nonatopic (n=183) subjects.

Eighty-five incident cases of sensitization to a LA-derived allergen were identified, 67 among atopic and 18 among nonatopic subjects. Baseline rhinitis symptoms in contact with pets and skin sensitization to pets were associated with the development of work-related rhinoconjunctivitis (RC) symptoms in atopic subjects, whereas perannual rhinitis symptoms and having a PC20(provocative concentration causing a 20% fall in forced expiratory volume in one second) ≤32 mg·mL−1were associated in nonatopic subjects. Baseline rhinitis symptoms on contact with pets and a PC20value ≤32 mg·mL−1were significant determinants for developing sensitization to a specific allergen in atopic subjects only. Finally, baseline rhinitis symptoms in contact with pets and perannual rhinitis symptoms were associated with the development of occupational RC in atopic subjects, whereas in nonatopic subjects this was associated with having a PC20value ≤32 mg·mL−1.

In conclusion, the determinants for the development of specific skin sensitization, symptoms and disease are different between atopic and nonatopic apprentices starting occupational exposure to laboratory-animal-derived allergens.