bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship Between Blood Pressure and Stroke Risk in Patients With Symptomatic Carotid Occlusive Disease
Authors: Rothwell P.M. , Howard S.C. , Spence J.D.
Published: November 2003

Background and Purpose—

Blood pressure lowering in patients with a previous transient ischemic attack (TIA) or stroke reduces the risk of recurrent stroke and coronary vascular events. However, there is uncertainty about the risks and benefits in patients with severe carotid occlusive disease, particularly those with a carotid occlusion or bilateral ≥70% carotid stenosis in whom cerebral perfusion is often impaired and may depend directly on systemic blood pressure. Therefore, we studied the effect of carotid artery disease on the relationship between blood pressure and stroke risk in patients with recent TIA or stroke.

Methods—

We compared the relationship between blood pressure (systolic and diastolic blood pressures, pulse pressure) and stroke risk in TIA and stroke patients with documented stenosis of at least 1 carotid artery [European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET)] with that in TIA and stroke patients with a low prevalence of carotid disease [United Kingdom Transient Ischaemic Attack (UK-TIA) Aspirin Trial]. In ECST and NASCET, we also determined the relationship between blood pressure and stroke risk in patients with unilateral carotid occlusion and patients with bilateral ≥70% carotid stenosis.

Results—

Stroke risk on medical treatment increased with blood pressure in ECST and NASCET, but the relationships were less steep than in the UK-TIA trial. The relationship between blood pressure and stroke risk was not affected by the presence of a unilateral carotid occlusion but was significantly affected by the presence of bilateral carotid stenosis ≥70% (interaction: systolic blood pressure,
P
=0.002; diastolic blood pressure,
P
=0.03; pulse pressure,
P
=0.003). In this group, the relationship was inverted because of the high stroke risks at lower blood pressures. This interaction was not present after carotid endarterectomy and was not present for the risk of myocardial infarction.

Conclusions—

The risk of stroke increases with blood pressure in the great majority of patients with symptomatic carotid artery disease, but the relationship is less steep than in other patients with TIA or stroke. The relationship is unaffected by unilateral carotid occlusion alone but is inverted in patients with bilateral ≥70% carotid stenosis, suggesting that aggressive blood pressure lowering may not be advisable in this group. These patients represent only a few percent of all patients with TIA or stroke but have a high risk of recurrent stroke.
Effect of Treatment of Carotid Artery Stenosis on Blood Pressure
Authors: McKevitt F.M. , Sivaguru A. , Venables G.S. , Cleveland T.J. , Gaines P.A. , Beard J.D. , Channer K.S.
Published: November 2003

Background and Purpose—

Carotid intervention by carotid endarterectomy (CEA) or endovascular treatment may cause hemodynamic change. The immediate and long-term effects on blood pressure after these procedures were assessed.

Methods—

Patients were randomized to CEA (n=49) or endovascular treatment (n=55) that comprised percutaneous transluminal angioplasty alone (n=31), balloon-expandable stent (n=13), or self-expandable stent (n=11). A baseline 24-hour ambulatory blood pressure recording was made before carotid intervention and repeated at 24 hours, 1 month, and 6 months after the procedure.

Results—

In the first 24 hours after the procedure, episodes of hypotension occurred in 75% of the CEA group and 76% of the endovascular group; hypertension occurred in 11% and 13%, respectively. There was a significant fall in blood pressure at 1 hour after the procedure in both groups (24 and 16 mm Hg fall in CEA and endovascular groups, respectively), but this was only sustained in the endovascular group. The pattern of blood pressure response in the first 24 hours was significantly different (
P
<0.0001, ANCOVA). Systolic blood pressure was significantly lower at 1 and 6 months only in the surgical group (6 and 5 mm Hg fall, respectively).

Conclusions—

Both CEA and endovascular treatment have an effect on blood pressure stability, particularly within the first 24 hours after the procedure.
Thrombomodulin mutant mice with a strongly reduced capacity to generate activated protein C have an unaltered pulmonary immune response to respiratory pathogens and lipopolysaccharide
Authors: Rijneveld Anita W. , Weijer Sebastiaan , Florquin Sandrine , Esmon Charles T. , Meijers Joost C. M. , Speelman Peter , Reitsma Pieter H. , Ten Cate Hugo , van der Poll Tom
Published: November 2003

The thrombomodulin–protein C–protein S (TM-PC-PS) pathway exerts anticoagulant and anti-inflammatory effects. We investigated the role of TM in the pulmonary immune response in vivo by the use of mice with a mutation in the TM gene (TMpro/pro) that was earlier found to result in a minimal capacity for activated PC (APC) generation in the circulation. We here demonstrate that TMpro/pro mice also display a strongly reduced capacity to produce APC in the alveolar compartment upon intrapulmonary delivery of PC and thrombin. We monitored procoagulant and inflammatory changes in the lung during Gram-positive (Streptococcus pneumoniae) and Gram-negative (Klebsiella pneumoniae) pneumonia and after local administration of lipopolysaccharide (LPS). Bacterial pneumonia was associated with fibrin(ogen) depositions in the lung that colocalized with inflammatory infiltrates. LPS also induced a rise in thrombin-antithrombin complexes in bronchoalveolar lavage fluid. These pulmonary procoagulant responses were unaltered in TMpro/pro mice, except for enhanced fibrin(ogen) deposition during pneumococcal pneumonia. In addition, TMpro/pro mice displayed unchanged antibacterial defense, neutrophil recruitment, and cytokine/chemokine levels. These data suggest that the capacity of TM to generate APC does not play a role of importance in the pulmonary response to respiratory pathogens or LPS.
The variable number of tandem repeat polymorphism of platelet glycoprotein Ibα and risk of coronary heart disease
Authors: Afshar-Kharghan Vahid , Matijevic-Aleksic Nevenka , Ahn Chul , Boerwinkle Eric , Wu Kenneth K. , López José A.
Published: November 2003

Glycoprotein (GP) Ib-IX-V complex plays an important role in formation of platelet-fibrin clot at the area of damaged vessel wall. One polymorphism of GP Ibα, the main component of GP Ib-IX-V complex, is due to variable numbers of tandem repeats (VNTRs) in the macroglycopeptide region of this molecule. We studied the association between the presence of different VNTR alleles of GP Ibα and the frequency of coronary heart disease (CHD) among individuals recruited to a large community-based case-cohort study (Atherosclerosis Risk in Communities [ARIC] study). We found that the distribution of VNTR alleles of GP Ibα is different among whites and African Americans. The B allele (with 3 repeats) of GP Ibα is relatively more common among African Americans compared with whites. In African Americans, the CC genotype (homozygous with 2 repeats) is associated with a lower risk of CHD events than all other genotypes. (Blood. 2004;103:963-965)
Cotransplantation of third-party mesenchymal stromal cells can alleviate single-donor predominance and increase engraftment from double cord transplantation
Authors: Kim Dong-Wook , Chung Yang-Jo , Kim Tai-Gyu , Kim Yoo-Li , Oh Il-Hoan
Published: November 2003

Although the infusion of umbilical cord blood (UCB) from multiple donors can be a strategy to overcome the cell dose limitation frequently encountered in UCB transplantation, clinical trials have revealed that cells from one donor dominate engraftment. To investigate the origin of and the factors influencing this inequality, we performed mixed transplantation of 2 UCB units with varying degrees of HLA disparities into NOD/SCID mice and determined donor origins by polymerase chain reaction–sequence-specific oligonucleotide probe (PCR-SSOP) or real-time quantitative (RQ)–PCR for human short tandem repeats (STRs). When total mononuclear cells from 2 units were transplanted as a mixture, cells from one donor predominated (ratio, 81:19), despite comparable overall engraftment when infused as single units, and no augmentation in overall engraftment was observed when compared with the single-unit controls. However, lineage depletion or cotransplantation of mesenchymal stromal cells (MSCs) expanded from third-party bone marrow resulted in more balanced coengraftment. Direct comparison of double UCB transplantation in the presence or absence of MSCs showed that the reduced deviation in the donor ratio (1.8:1 vs. 2.8:1) correlated with a higher overall level of engraftment with MSC cotransplantation. These results indicate that third-party MSCs can be used to alleviate donor deviation and to facilitate engraftment of multidonor UCB.
Pregnancy induces minor histocompatibility antigen–specific cytotoxic T cells: implications for stem cell transplantation and immunotherapy
Authors: Verdijk Rob M. , Kloosterman Antoinette , Pool Jos , van de Keur Maarten , Naipal Albert M. I. H. , van Halteren Astrid G. S. , Brand Anneke , Mutis Tuna , Goulmy Els
Published: November 2003

Recipients of HLA-identical stem cell transplants have a poorer transplant outcome if the donor is female rather than male. We analyzed whether pregnancy primes for minor histocompatibility (H) antigens. Peripheral blood mononuclear cells (PBMCs) from healthy multiparous female blood donors were depleted for CD4+, CD14+, CD16+, and CD19+ cells, stained with minor H antigen–specific HLA-A2 tetramers, sorted by fluorescence-activated cell sorting, and tested for cytotoxic activity. Minor H antigens HY-, HA-1–, and HA-2–specific cytotoxic T cells (CD8+, CD45RA–) were present in PBMCs from 4 of 7 female donors up to 22 years after the last delivery. Interestingly, in 2 of the 4 cases microchimerism of the putative immunizing minor H antigen was observed. Thus, pregnancy can lead to alloimmune responses against the infant's paternal minor H antigens. The minor H antigen immunization status of female donors raises important questions for the clinical practice of stem cell transplantation.
CCL19/CCL21-triggered signal transduction and migration of dendritic cells requires prostaglandin E2
Authors: Scandella Elke , Men Ying , Legler Daniel F. , Gillessen Silke , Prikler Ladislav , Ludewig Burkhard , Groettrup Marcus
Published: November 2003

The control of dendritic cell (DC) migration is pivotal for the initiation of cellular immune responses. When activated with inflammatory stimuli, the chemokine receptor CCR7 is up-regulated on DCs. Activated DCs home to lymphoid organs, where the CCR7 ligands CCL19 and CCL21 are expressed. We previously found that human monocyte-derived DCs (MoDCs) exclusively migrated to CCL19 and CCL21 when matured in the presence of prostaglandin (PG) E2. Because PGE2 did not alter CCR7 cell surface expression, we examined whether PGE2 may exert its effect by coupling CCR7 to signal transduction modules. Indeed, stimulation with CCR7 ligands led to enhanced phosphatidylinositol-3-kinase–mediated phosphorylation of protein kinase B when MoDCs were matured in the presence of PGE2. Moreover, CCL19/CCL21-induced intracellular calcium mobilization in MoDCs occurred only when PGE2 was present during maturation. MoDC migration to CCL19 and CCL21 was dependent on phospholipase C and intracellular calcium flux but not on phosphatidylinositol-3 kinase. Hence, our data provide insight into CCL19/CCL21-triggered signal transduction pathways and identify a novel function for PGE2 in controlling the migration of mature MoDCs by facilitating CCR7 signal transduction.
Adhesion to E-selectin promotes growth inhibition and apoptosis of human and murine hematopoietic progenitor cells independent of PSGL-1
Authors: Winkler Ingrid G. , Snapp Karen R. , Simmons Paul J. , Lévesque Jean-Pierre
Published: November 2003

Although both P- and E-selectin are constitutively expressed on bone marrow endothelial cells, their role in the regulation of hematopoiesis has only recently been investigated. We have previously shown that P-selectin glycoprotein ligand-l (PSGL-1/CD162) is expressed by primitive human bone marrow CD34+ cells, mediates their adhesion to P-selectin, and, more importantly, inhibits their proliferation. We now demonstrate that adhesion to E-selectin inhibits the proliferation of human CD34+ cells isolated either from human umbilical cord blood, adult mobilized blood, or steady-state bone marrow. Furthermore, a subpopulation, which does not contain the most primitive hematopoietic progenitor cells, undergoes apoptosis following E-selectin–mediated adhesion. The same phenomenon was observed in cells isolated from mouse bone marrow. Using lineage-negative Sca-1+ c-KIT+ bone marrow cells from PSGL-1–/– and wild-type mice, we establish that PSGL-1 is not the ligand involved in E-selectin–mediated growth inhibition and apoptosis. Moreover, stable transfection of the human myeloid cell line K562 (which does not express PSGL-1) with α(1,3) fucosyltransferase VII alone was sufficient to recapitulate the E-selectin–mediated growth inhibition and apoptosis observed in hematopoietic progenitor cells. These data demonstrate that an E-selectin ligand(s) other than PSGL-1 transduces growth inhibitory and proapoptotic signals and requires posttranslational fucosylation to be functional.
Internal tandem duplication mutation of FLT3 blocks myeloid differentiation through suppression of C/EBPα expression
Authors: Zheng Rui , Friedman Alan D. , Levis Mark , Li Li , Weir Edward G. , Small Donald
Published: November 2003

Constitutively activating mutations of FMS-like tyrosine kinase 3 (FLT3) occur in approximately one third of patients with acute myeloid leukemia (AML) and are associated with poor prognosis. Altered FLT3 signaling leads to antiapoptotic and proliferative signaling pathways. We recently showed that these mutations can also contribute to the differentiation arrest that characterizes leukemia. In this report we investigated the mechanism by which internal tandem duplication (ITD) mutation of FLT3 signaling blocks differentiation. Normally, myeloid differentiation requires the induction of CCAAT/enhancer-binding protein α (C/EBPα) and PU.1 expression. Expression of both genes was repressed by FLT3/ITD signaling in 32Dcl3 (32D) cells and this repression was overcome by treatment with a FLT3 inhibitor, allowing differentiation to proceed. We also observed increased expression of C/EBPα and PU.1 accompanied by signs of differentiation in 2 of 3 primary AML samples from patients with FLT3/ITD mutations receiving a FLT3 inhibitor, CEP-701, as part of a clinical trial. Forced expression of C/EBPα was also able to overcome FLT3/ITD-mediated differentiation block, further proving the importance of C/EBPα in this process.
Overexpression of IL-7Rα provides a competitive advantage during early T-cell development
Authors: Laouar Yasmina , Crispe I. Nicholas , Flavell Richard A.
Published: November 2003

Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre–T-cell antigen receptor. Although αβ T-cell development is observed in IL-7– and IL-7Rα–deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7Rα that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7Rα was revealed by surface staining, and increased IL-7Rα mRNA was documented by using reverse transcriptase–polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL+ (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]–fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.
Receptor synergy of interleukin-6 (IL-6) and insulin-like growth factor-I in myeloma cells that highly express IL-6 receptor α
Authors: Abroun Saeid , Ishikawa Hideaki , Tsuyama Naohiro , Liu Shangqin , Li Fu-Jun , Otsuyama Ken-ichiro , Zheng Xu , Obata Masanori , Kawano Michio M.
Published: November 2003

Interleukin-6 (IL-6) is a growth and antiapoptotic factor for human myeloma cells. The autocrine loop and increased expression of the growth factor receptors have been postulated as the mechanisms of tumorigenesis. Here we show that IL-6 stimulation induced the phosphorylation of insulin-like growth factor-I (IGF-I) receptors in a human myeloma cell line, NOP2, highly expressing IL-6 receptor α (IL-6Rα) and in the IL-6Rα–transfected U266 cell line. IL-6–dependent complex formation of IL-6Rα with IGF-I receptor β was found in NOP2 where IL-6Rα colocalized with IGF-I receptors at lipid rafts. Moreover, the IL-6–induced phosphorylation of IGF-I receptor β was not blocked by a Janus kinase 2 (Jak2) inhibitor. In addition to the activation of the signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2, IL-6 stimulation led to the activation of Akt, presumably following the phosphorylation of IGF-I receptors. Thus, our results suggest that in NOP2, IL-6Rα and IGF-I receptors exist on the plasma membrane in close proximity, facilitating the efficient assembly of 2 receptors in response to IL-6. The synergistic effects of highly expressed IL-6Rα on IGF-I receptor–mediated signals provide a novel insight into the Jak-independent IL-6 signaling mechanism of receptor cross-talk in human myeloma cells.
Recombinant factor VIIa restores aggregation of αIIbβ3-deficient platelets via tissue factor–independent fibrin generation
Authors: Lisman Ton , Adelmeijer Jelle , Heijnen Harry F. G. , de Groot Philip G.
Published: November 2003

Recombinant factor VIIa (rFVIIa) is a safe and effective prohemostatic drug for patients with Glanzmann thrombasthenia (GT). However, the mechanism of action of rFVIIa in these patients is still unclear. Although patients with GT are characterized by a complete absence of platelet aggregation to a variety of agonists, it has been shown that GT platelets are able to form aggregates, provided polymerizing fibrin is present. We studied the effect of rFVIIa-mediated fibrin formation on aggregation of αIIbβ3-deficient platelets. When washed platelets from GT patients or platelets from healthy volunteers treated with an arginyl-glycyl-aspartyl–containing peptide were activated with collagen in the presence of rFVIIa and purified coagulation factors X, II, and fibrinogen, complete aggregation occurred after a lag phase. Fibrin generation proceeded via rFVIIa-mediated thrombin generation on the activated platelet surface independently of tissue factor. Electron microscopic analysis of αIIbβ3-independent platelet aggregates showed a densely packed structure suggestive of a true platelet-fibrin interaction and not via trapping of platelets into a fibrin network. Also, rFVIIa-mediated αIIbβ3-independent aggregation was demonstrated under conditions of flow using a collagen-coated surface. In conclusion, the efficacy of rFVIIa in GT patients might be explained by induction of αIIbβ3-independent platelet aggregation, which compensates the lack of αIIbβ3-dependent aggregation.
Platelet factor 4 (PF-4)–induced neutrophil adhesion is controlled by src-kinases, whereas PF-4–mediated exocytosis requires the additional activation of p38 MAP kinase and phosphatidylinositol 3-kinase
Authors: Kasper Brigitte , Brandt Ernst , Bulfone-Paus Silvia , Petersen Frank
Published: November 2003

Among the various chemokines that are functionally active on neutrophils, platelet factor 4 (PF-4; CXCL4) appears to have a specialized role. Lacking typical chemokine activities, PF-4 stimulates neutrophils to undergo firm adhesion to endothelial cells and, in the presence of an appropriate costimulus like tumor necrosis factor (TNF), PF-4 induces exocytosis of secondary granule contents. Analyzing the individual contribution of PF-4 and its costimuli in the control of these functions at the signaling level, we demonstrate that TNF-induced activation of p38 mitogen-activated protein (MAP) kinase (but not extracellular regulated kinase [Erk] kinases) acts as general and essential costimulatory signal in PF-4–dependent neutrophil exocytosis. This was shown by the use of a specific inhibitor (SB203580), by biologic (lipopolysaccharide, N-formyl-methionyl-leucyl-phenylalanine) and pharmacologic (anisomycin) activators of p38 MAP kinase, and by phosphorylation studies. Furthermore, TNF-mediated activation of phosphatidylinositol 3-kinase (PI 3-kinase) represents an additional essential signaling component in this process as demonstrated by studies with its inhibitor wortmannin as well as by analysis of the phosphorylation of AKT kinase. PF-4, however, directly activates src-kinases and PF-4–induced adherence as well as PF-4/TNF-mediated exocytosis was inhibited by an src-kinase inhibitor PP1. Taken together, neutrophil exocytosis and adherence are regulated on p38 MAP kinase, PI 3-kinase, and src-kinase activation.
Vav1: an oncogene that regulates specific transcriptional activation of T cells
Authors: Katzav Shulamit
Published: November 2003

The nuclear factor of activated T cells (NFAT) proteins are a family of transcription factors whose activation is controlled by calcineurin, a Ca2+-dependent phosphatase. Once dephosphorylated, these proteins move to the nucleus where they interact with cofactors to form transcription factor complexes. Inhibition of NFAT proteins by immunosuppressants, such as cyclosporin A (CsA) and FK506, is used clinically to prevent transplant rejection. Although these drugs have revolutionized organ transplantation, their use is associated with severe side effects in other organs in which NFAT proteins are important. One of the signal transducers that controls NFAT activity is Vav1, which is exclusively expressed in the hematopoietic system. Vav1 contains numerous modular domains that enable its function as a guanine exchange factor (GEF) toward RhoGTPases as well as participate in protein-protein interactions. This review focuses on the mechanisms by which Vav1 regulates NFAT through GEF-dependent and -independent cascades, emphasizing the newly assigned role of Vav1 in the regulation of Ca2+ release. Because of its restriction to hematopoietic cell lineages and its importance in the regulation of NFAT, targeting Vav1 and, in particular, its association with other proteins may offer a highly selective means of modifying T-cell behavior, thus allowing the development of more specific immunosuppressive therapies.
Insulin-like growth factor 2 expressed in a novel fetal liver cell population is a growth factor for hematopoietic stem cells
Authors: Zhang Cheng Cheng , Lodish Harvey F.
Published: November 2003

Hematopoietic stem cells (HSCs) undergo dramatic expansion during fetal liver development, but attempts to expand their numbers ex vivo have failed. We hypothesized that unidentified fetal liver cells produce growth factors that support HSC proliferation. Here we describe a novel population of CD3+ and Ter119- day-15 fetal liver cells that support HSC expansion in culture, as determined by limiting dilution mouse reconstitution analyses. DNA array experiments showed that, among other proteins, insulin-like growth factor 2 (IGF-2) is specifically expressed in fetal liver CD3+ cells but not in several cells that do not support HSCs. Treatment of fetal liver CD3+Ter119- cells with anti–IGF-2 abrogated their HSC supportive activity, suggesting that IGF-2 is the key molecule produced by these cells that stimulates HSC expansion. All mouse fetal liver and adult bone marrow HSCs express receptors for IGF-2. Indeed, when combined with other growth factors, IGF-2 supports a 2-fold expansion of day-15 fetal liver Lin-Sca-1+c-Kit+ long-term (LT)–HSC numbers. Thus, fetal liver CD3+Ter119- cells are a novel stromal population that is capable of supporting HSC expansion, and IGF-2, produced by these cells, is an important growth factor for fetal liver and, as we show, adult bone marrow HSCs.
Adult stem cells from bone marrow (MSCs) isolated from different strains of inbred mice vary in surface epitopes, rates of proliferation, and differentiation potential
Authors: Peister Alexandra , Mellad Jason A. , Larson Benjamin L. , Hall Brett M. , Gibson Laura F. , Prockop Darwin J.
Published: November 2003

For reasons that are not apparent, it has been difficult to isolate and expand the adult stem cells referred to as mesenchymal stem cells or marrow stromal cells (MSCs) from murine bone marrow. We developed a protocol that provides rapidly expanding MSCs from 5 strains of inbred mice. The MSCs obtained from 5 different strains of mice were similar to human and rat MSCs in that they expanded more rapidly if plated at very low density, formed single-cell–derived colonies, and readily differentiated into either adipocytes, chondrocytes, or mineralizing cells. However, the cells from the 5 strains differed in their media requirements for optimal growth, rates of propagation, and presence of the surface epitopes CD34, stem cell antigen-1 (Sca-1), and vascular cell adhesion molecule 1 (VCAM-1). The protocol should make it possible to undertake a large number of experiments with MSCs in transgenic mice that have previously not been possible. The differences among MSCs from different strains may explain some of the conflicting data recently published on the engraftment of mouse MSCs or other bone marrow cells into nonhematopoietic tissues.
Erythrocyte detergent-resistant membrane proteins: their characterization and selective uptake during malarial infection
Authors: Murphy Sean C. , Samuel Benjamin U. , Harrison Travis , Speicher Kaye D. , Speicher David W. , Reid Marion E. , Prohaska Rainer , Low Philip S. , Tanner Michael J. , Mohandas Narla , Haldar Kasturi
Published: November 2003

Infection of human erythrocytes by the apicomplexan malaria parasite Plasmodium falciparum results in endovacuolar uptake of 4 host proteins that reside in erythrocyte detergent-resistant membranes (DRMs). Whether this vacuolar transport reflects selective uptake of host DRM proteins remains unknown. A further complication is that DRMs of vastly different protein and cholesterol contents have been isolated from erythrocytes. Here we show that isolated DRMs containing the highest cholesterol-to-protein ratio have low protein mass. Liquid chromatography, mass spectrometry, and antibody-based studies reveal that the major DRM proteins are band 3, flotillin-1 and -2, peroxiredoxin-2, and stomatin. Band 3 and stomatin, which reflect the bulk mass of erythrocyte DRM proteins, and all tested non-DRM proteins are excluded from the vacuolar parasite. In contrast, flotillin-1 and -2 and 8 minor DRM proteins are recruited to the vacuole. These data suggest that DRM association is necessary but not sufficient for vacuolar recruitment and there is active, vacuolar uptake of a subset of host DRM proteins. Finally, the 10 internalized DRM proteins show varied lipid and peptidic anchors indicating that, contrary to the prevailing model of apicomplexan vacuole formation, DRM association, rather than lipid anchors, provides the preferred criteria for protein recruitment to the malarial vacuole.
Local irradiation enhances congenic donor pluripotent hematopoietic stem cell engraftment similarly in irradiated and nonirradiated sites
Authors: Ito Hiroshi , Takeuchi Yasuo , Shaffer Juanita , Sykes Megan
Published: November 2003

Long-term multilineage chimerism is achieved in CD45 congenic mice receiving high bone marrow doses with or without mediastinal irradiation (MI). Increased donor chimerism results in MI-treated compared with nonirradiated animals, suggesting that MI makes “space” for engraftment of donor pluripotent hematopoietic stem cells (PHSCs). We have now examined whether space is systemic or whether increased engraftment of donor marrow in locally irradiated mice is confined to the irradiated bones. While increased donor chimerism was observed in irradiated bones compared with nonirradiated bones of MI-treated animals 4 weeks following bone marrow transplantation (BMT), these differences were minimal by 40 weeks. MI-treated chimeras contained more adoptively transferable donor PHSCs in the marrow of both irradiated and distant bones compared with non-MI–treated chimeras. Similar proportions of donor PHSCs were present in irradiated and nonirradiated bones of locally irradiated mice at both 4 and 40 weeks. Irradiated bones contained more donor short-term repopulating cells than distant bones at 4 weeks, but not 40 weeks, after BMT. Our study suggests that local proliferation of donor PHSCs in mice receiving local irradiation rapidly leads to a systemic increase in donor PHSC engraftment.
Acquired somatic ATRX mutations in myelodysplastic syndrome associated with α thalassemia (ATMDS) convey a more severe hematologic phenotype than germline ATRX mutations
Authors: Steensma David P. , Higgs Douglas R. , Fisher Chris A. , Gibbons Richard J.
Published: November 2003

Acquired somatic mutations in ATRX, an X-linked gene encoding a chromatin-associated protein, were recently identified in 4 patients with the rare subtype of myelodysplastic syndrome (MDS) associated with α thalassemia (ATMDS). Here we describe a series of novel point mutations in ATRX detected in archival DNA samples from marrow and/or blood of patients with ATMDS by use of denaturing high-performance liquid chromatography (DHPLC), a technique sensitive to low-level mosaicism. Two of the new mutations result in changes in amino acids altered in previously described pedigrees with germ line ATRX mutations (ATR-X syndrome), but the hematologic abnormalities were much more severe in the patients with ATMDS than in the corresponding constitutional cases. In one ATMDS case where DNA samples from several time points were available, the proportion of ATRX-mutant subclones correlated with changes in the amount of hemoglobin H. This study strengthens the link between acquired, somatic ATRX mutations and ATMDS, illustrates how molecular defects associated with MDS and other hematologic malignancies masked by somatic mosaicism may be detected by DHPLC, and shows that additional factors increase the severity of the hematologic phenotype of ATRX mutations in ATMDS.
Primary cutaneous CD8+ and CD56+ T-cell lymphomas express HLA-G and killer-cell inhibitory ligand, ILT2
Authors: Urosevic Mirjana , Kamarashev Jivko , Burg Günter , Dummer Reinhard
Published: November 2003

Primary cutaneous lymphomas constitute a spectrum of diseases characterized by a clonal accumulation of lymphocytes in the skin. Cutaneous T-cell lymphomas of the cytotoxic phenotype, including CD8+ and CD56+ lymphomas, are rare entities that have only been recently recognized and characterized. These lymphomas often show an aggressive clinical course. We investigated the expression of human leukocyte antigen G (HLA-G) and interleukin 10 (IL-10) in conjunction with expression of HLA-G killer-cell inhibitory receptor ligand immunoglobulin-like transcript 2 (ILT2) in 3 CD56+CD4+ and 4 CD8+ cutaneous T-cell lymphomas. HLA-G expression was detected in 2 of 3 lymphomas of the CD56+CD4+ type and in all lymphomas of CD8+ type. It is of note that CD56+CD4+ lymphomas displayed stronger HLA-G reactivity. The expression of IL-10 matched the expression of HLA-G. Together with the expression of IL-10, HLA-G might be one of the factors accounting for the evasion of immunosurveillance, thus contributing to aggressive phenotype of these lymphoma entities.
Expression of MRP8 and MRP14 by macrophages is a marker for severe forms of glomerulonephritis
Authors: Frosch Michael , Vogl Thomas , Waldherr Rüdiger , Sorg Clemens , Sunderkötter Cord , Roth Johannes
Published: November 2003

Expression of two S100 proteins, myeloid related protein (MRP)8 and MRP14, as well as their complex formation indicate proinflammatory properties of macrophages. We analyzed if the different forms of glomerulonephritis (GN) are associated with the appearance of certain phenotypes of infiltrating macrophages characterized by expression of MRP8 and MRP14 as well as their complex formation. Immunohistochemical analysis of 89 renal biopsies with different forms of nephritis revealed that expression and complex formation of MRP8 and MRP14 by infiltrating macrophages in the glomeruli correlated with the severity of the inflammatory process. As such, MRP8/MRP14-expressing monocytes prevailed in highly proliferating forms of GN, i.e., systemic lupus erythematosus GN and extracapillary GN. In contrast, a high percentage of macrophages in the renal interstitium expressed MRP8 and MRP14 without concomitant formation of their complex, and they indicated a chronic type of inflammatory reaction in GN. Immunosuppressive drugs had no direct effects on the expression of MRP8 and MRP14 in macrophages in vitro. The correlation of MRP8 and MRP14 expression with disease activity indicates that these calcium-binding proteins are of pathophysiological relevance in GN. In addition, our findings reflect differences in the inflammatory mechanisms underlying the various forms of GN, as they revealed that distinct macrophage subpopulations prevail in the different forms of GN.
Shielding the double-edged sword: negative regulation of the innate immune system
Authors: Kobayashi Koichi S , Flavell Richard A
Published: November 2003

The innate immune system is evolutionarily conserved among all multicellular organisms and is the first line of defense against microorganisms. It enables the host not only to combat pathogenic organisms but also to cohabit with nonpathogenic microorganisms by balancing the host-microorganism interaction. The innate immune response is activated rapidly (within hours) compared with adaptive immunity. Activation of the innate immune system allows the activation of the adaptive immune response by production of proinflammatory cytokines and by providing stimulatory signals via major histocompatibility complex molecules and costimulatory molecules such as CD40, CD80, or CD86; together, these lead to the full activation of both immune systems to fight against pathogenic microorganisms. Activation of the innate immune system, however, can be a double-edged sword for the host. Proinflammatory cytokines mediate a positive feedback loop on the innate immune system, and overproduction of cytokines, if unchecked, is hazardous to the host and may cause severe outcomes such as hyperthermia, organ failure, and even death in extreme cases. Moreover, if the overproduction of proinflammatory cytokines persists, it may cause chronic inflammatory diseases. During evolution, the innate immune system has acquired complicated regulatory systems to control itself so that this “sword” will not kill the host. Various mechanisms including inhibition of Toll-like receptor signaling by interleukin-1 receptor-associated kinase-M have evolved for this purpose and are important not only to fight against pathogenic microorganisms efficiently but also are critical for the peaceful coexistence with commensal bacterial flora.
Mycobacterial heat shock protein 65 enhances antigen cross-presentation in dendritic cells independent of Toll-like receptor 4 signaling
Authors: Chen Kang , Lu Jinhua , Wang Lei , Gan Yunn-Hwen
Published: November 2003

Heat shock proteins (HSP) have been shown to enhance antigen processing and presentation through their association with antigenic peptides and delivery of these moieties into major histocompatibility complex class I pathways. In this study, mycobacterial Hsp65 is demonstrated to have the ability to help cross-present an exogenous protein by dendritic cells (DC) to CD8 T cells without the need for complex formation between Hsp65 and the protein. This abilit of Hsp65 to enhance cross-presentation is independent of its weak stimulatory effect on DC, the latter seen only after prolonged incubation. When the effect of lipopolysaccharide contamination is abrogated, Hsp65 is unable to activate Toll-like receptor (TLR)4 in the presence of CD14 and MD2. This accounts for the inability of Hsp65 to drive maturation of DC and shows that Hsp65 is not a potent stimulator of DC. Thus, Hsp65 enhances the cross-presentation of a soluble, free antigen by DC, independent of TLR4 signaling and up-regulation of costimulatory molecules.
Trefoil peptide TFF2 treatment reduces VCAM-1 expression and leukocyte recruitment in experimental intestinal inflammation
Authors: Soriano-Izquierdo Antonio , Gironella Meritxell , Massaguer Anna , May Felicity E B , Salas Antonio , Sans Miquel , Poulsom Richard , Thim Lars , Piqué Josep M , Panés Julián
Published: November 2003

There is evidence for a beneficial effect of trefoil peptides in animal models of gastric damage and intestinal inflammation, but the optimal treatment strategy and the mechanistic basis have not been explored thoroughly. It has been suggested that these proteins may modulate the inflammatory response. The aims of this study were to compare the protective and curative value of systemic and topical trefoil factor family (TFF)2 administration in dextran sulfate sodium-induced experimental colitis and to investigate the relationship between the therapeutic effects of TFF2 and modulation of leukocyte recruitment and expression of cell adhesion molecules. Clinical and morphologic severity of colitis was evaluated at the end of the study (Day 10). Leukocyte–endothelial cell interactions were determined in colonic venules by fluorescence intravital microscopy. The expression of cell adhesion molecules vascular cell adhesion molecule 1 (VCAM-1) and mucosal addressin cell adhesion molecule 1 (MAdCAM-1) was measured by the dual radiolabeled monoclonal antibody technique. Pretreatment with TFF2 by subcutaneous or intracolonic (ic) route ameliorated the clinical course of colitis, and the luminal route had a significantly superior effect. This beneficial effect was correlated with significant reductions in endothelial VCAM-1 but not MAdCAM-1 expression and leukocyte adhesion to intestinal venules, which returned to levels similar to those of controls. In established colitis, ic TFF2 treatment did not modify the severity of colonic lesions. In conclusion, TFF2 is useful in the treatment of colitis, and topical administration is superior to the systemic route. Reduction in adhesion molecule expression and leukocyte recruitment into the inflamed intestine contributes to the beneficial effect of this treatment.
Comparative evaluation of CC chemokine-induced migration of murine CD8α+ and CD8α− dendritic cells and their in vivo trafficking
Authors: Colvin Bridget L , Morelli Adrian E , Logar Alison J , Lau Audrey H , Thomson Angus W
Published: November 2003

Murine CD11c+CD8α− and CD11c+CD8α+ dendritic cells (DCs) differentially regulate T cell responses. Although specific chemokines that recruit immature (i) or mature (m) CD8α− DCs have been identified, little is known about the influence of chemokines on CD8α+ DCs. iDCs and mDCs isolated from spleens of fms-like tyrosine kinase 3 ligand-treated B10 mice were compared directly for migratory responses to a panel of CC chemokines or following local or systemic administration. In vitro assays were performed using Transwell® chambers. iDCs did not respond to any CC chemokines tested. Both subsets of mDCs migrated to CCL19 and CCL21, with consistently lower percentages of CD8α+ DCs migrating. Chemokine receptor mRNA and protein expression were analyzed, but no correlation between expression and function was demonstrated. In vivo trafficking of fluorochrome-labeled DCs (B10; H2b) was assessed by immunohistochemistry and by rare-event flow cytometric analysis of allogeneic recipient (BALB/c; H2d) draining lymph node (DLN) and spleen cells. Twenty-four hours after intravenous injection, chloromethylfluorescein diacetate-positive CD8α+ and CD8α− mDCs were detected by immunohistochemistry in spleens in similar numbers (that decreased over time). Following subcutaneous injection, both DC subsets were detected in DLN at 24 h, but only CD8α− DCs were evident by flow analysis at 48 h. Although CD8α+ DCs migrate from peripheral tissues to T cell areas of (allogeneic) secondary lymphoid organs, they appear to mobilize as mDCs and less efficiently than CD8α− mDCs.
High-Dose Methotrexate-Based Chemotherapy Followed by Consolidating Radiotherapy in Non–AIDS-Related Primary Central Nervous System Lymphoma: European Organization for Research and Treatment of Cancer Lymphoma Group Phase II Trial 20962
Authors: Poortmans Philip M.P. , Kluin-Nelemans Hanneke C. , Haaxma-Reiche Hanny , Van’t Veer Mars , Hansen Mads , Soubeyran Pierre , Taphoorn Martin , Thomas José , Van den Bent Martin , Fickers Martin , Van Imhoff Gustaaf , Rozewicz Cynthia , Teodorovic Ivana , van Glabbeke Martine
Published: November 2003

Purpose: To confirm the feasibility and estimate the efficacy of methotrexate (MTX), teniposide, carmustine, and methylprednisolone (MBVP) chemotherapy combined with radiotherapy (RT) for patients with non–AIDS-related primary CNS lymphoma (PCNSL) treated in a multicenter setting.

Patients and Methods: Treatment consisted of two cycles of MBVP (MTX 3 g/m2 days 1 and 15, teniposide 100 mg/m2 days 2 and 3, carmustine 100 mg/m2 day 4, methylprednisolone 60 mg/m2 days 1 to 5, and two intrathecal injections of MTX 15 mg, cytarabine 40 mg, and hydrocortisone 25 mg) followed by 40 Gy of RT. Primary end points were response and safety of this regimen.

Results: Twelve centers included 52 patients who were all analyzed on an intent-to-treat basis. Median follow-up of all patients was 27 months. One patient progressed and died before treatment, and five patients died during treatment. Four patients received RT after one cycle of chemotherapy, and 42 patients completed the entire treatment. Hematologic grade 3 and 4 toxicity was seen in 78% of patients for leukocytes and 24% of patients for platelets. The overall response rate of all 52 patients was 81%. Two patients who did not fulfill the criteria of objective response survived more than 1 year; one of them is still alive without disease. Eighteen patients died; 11 deaths were a result of tumor, five were probably treatment-related, one was caused by late leukoencephalopathy, and one was a result of intercurrent disease. Median estimated overall survival was 46 months.

Conclusion: MBVP followed by RT for PCNSL has a high response rate. However, the 10% toxic death rate during treatment in a multicenter setting underlines the need for highly specialized care.
Radiotherapy Patterns of Care Study in Lung Carcinoma
Authors: Movsas B. , Moughan J. , Komaki R. , Choy H. , Byhardt R. , Langer C. , Goldberg M. , Graham M. , Ettinger D. , Johnstone D. , Abrams R. , Munden R. , Starkschall G. , Owen J.
Published: November 2003

Purpose: For the first time, a lung Patterns of Care Study was conducted to determine the national patterns of radiation (RT) practice in patients treated for nonmetastatic lung cancer in 1998 to 1999.

Materials and Methods: A national survey of randomly selected RT institutions in the United States was conducted using two-stage cluster sampling, stratified by practice type. Patients with nonmetastatic lung cancer (Karnofsky performance score [KPS] ≥ 60), who received RT as definitive or adjuvant therapy, were randomly selected. To determine national estimates, sample size was weighted by the relative number of institutions per strata and the number of patient records reviewed per the number of patients eligible. Accordingly, 42,335 patient records from 58 institutions were reviewed by trained research associates. The unweighted sample size (or number of patients) was 541.

Results: The histologies were small-cell lung cancer (SCLC) in 14.5% of patients versus non–small-cell lung cancer (NSCLC) in 85.5% of patients. The median age was 67 years (range, 29 to 92 years); 61% of patients were male, and 38% were current smokers. Bone scans and brain imaging were not obtained in 34% and 52% of clinical stage (CS) III NSCLC patients, respectively. Regarding treatment strategies, for SCLC and CS III NSCLC, chemotherapy plus RT was used significantly more than RT alone (P < .05); in CS I NSCLC, RT alone was the primary treatment (P < .05). Overall, 58% of patients received systemic therapy. On multivariate analysis, factors correlating with increased use of chemotherapy included younger age, histology (SCLC > NSCLC), increasing CS, increasing KPS, and lack of comorbidities. Only 3% of all patients were treated on prospective clinical trials.

Conclusion: This study establishes the general patterns of care for lung carcinoma in RT facilities within the United States. As supported by clinical trials, patients with limited-stage SCLC and CS III NSCLC received chemotherapy plus RT more than they received RT alone. Further improvements in staging, smoking cessation, and increased accrual to clinical trials must be encouraged.
Primary Central Nervous System Lymphoma: Results of a Pilot and Phase II Study of Systemic and Intraventricular Chemotherapy With Deferred Radiotherapy
Authors: Pels Hendrik , Schmidt-Wolf Ingo G.H. , Glasmacher Axel , Schulz Holger , Engert Andreas , Diehl Volker , Zellner Anton , Schackert Gabriele , Reichmann Heinz , Kroschinsky Frank , Vogt-Schaden Marlies , Egerer Gerlinde , Bode Udo , Schaller Carlo , Deckert Martina , Fimmers Rolf , Helmstaedter Christoph , Atasoy Aslihan , Klockgether Thomas , Schlegel Uwe
Published: November 2003

Purpose: To evaluate response rate, response duration, overall survival (OS), and toxicity in primary CNS lymphoma (PCNSL) after systemic and intraventricular chemotherapy with deferred radiotherapy.

Patients and Methods: From September 1995 to July 2001, 65 consecutive patients with PCNSL (median age, 62 years) were enrolled onto a pilot and phase II study evaluating chemotherapy without radiotherapy. A high-dose methotrexate (MTX; cycles 1, 2, 4, and 5) and cytarabine (ARA-C; cycles 3 and 6)–based systemic therapy (including dexamethasone, vinca-alkaloids, ifosfamide, and cyclophosphamide) was combined with intraventricular MTX, prednisolone, and ARA-C.

Results: Sixty-one of 65 patients were assessable for response. Of these, 37 patients (61%) achieved complete response, six (10%) achieved partial response, and 12 (19%) progressed under therapy. Six (9%) of 65 patients died because of treatment-related complications. Follow-up is 0 to 87 months (median, 26 months). The Kaplan-Meier estimates for median time to treatment failure (TTF) and median OS were 21 months and 50 months, respectively. For patients older than 60 years, median survival was 34 months, and the median TTF was 15 months. In patients younger than 61 years, median survival and median TTF have not been reached yet; the 5-year survival fraction is 75%. Systemic toxicity was mainly hematologic. Ommaya reservoir infection occurred in 12 patients (19%), and permanent cognitive dysfunction possibly as a result of treatment occurred in only two patients (3%).

Conclusion: Primary chemotherapy based on high-dose MTX and ARA-C is highly efficient in PCNSL. Response rate and response duration in this series are comparable to the response rates and durations reported after combined radiotherapy and chemotherapy. Neurotoxicity was infrequent.