bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous infusion of recombinant factor VIIa for surgery in patients with deficiency of factor VII
Authors: Tjønnfjord Geir E. , Wallensten Richard , Martinowitz Uri , Kenet Gili , Schulman Sam 
Published: November 2005

SummaryThe administration of recombinant activated factor VII (rFVIIa) by continuous infusion has provided a safe and convenient alternative to bolus injections in haemophiliacs with inhibitors, but it has only been reported in a single case with congenital factorVII (FVII) deficiency. The results of 12 consecutive surgical procedures in 7 patients with congenital FVII deficiency are reported here. rFVIIa was always given in continuous infusion, aiming at plasma FVII activity of 0.5 IU/mL. Treatment was given for 2 to 7 days with a mean total dose of 7.8 mg rFVIIa. Blood loss was as expected from the different types of procedures and the only thromboembolic complication was a superficial thrombophlebitis at the infusion site. This mode of substitution was therefore safe, effective and well tolerated.
Neutrophil P-selectin-glycoprotein-ligand-1 binding to platelet P-selectin enhances metalloproteinase 2 secretion and platelet-neutrophil aggregation
Authors: Abou-Saleh Haissam , Théorêt Jean-François , Yacoub Daniel , Merhi Yahye 
Published: November 2005

SummaryPlatelets and neutrophils constitute a high source of metalloproteinases (MMPs), and their interactions via P-selectin and Pselectin- glycoprotein-ligand-1 (PSGL-1) are involved in thrombosis, vascular remodelling, and restenosis. We investigated the impact of these interactions on platelet MMP-2 secretion and function in platelet and neutrophil aggregation. The secretion of MMP-2 from human platelets was significantly increased threefold after thrombin activation, and enhanced two-fold in the presence of neutrophils. Neutrophil supernatant had no effect on platelet MMP-2 secretion. While no MMP-2 was detected in the supernatant of neutrophils, a high amount of MMP-9 was released by neutrophils, and remained unchanged upon thrombin activation or in the presence of platelets. Platelet P-selectin, which increased significantly after activation, triggered platelet binding to neutrophils that was completely inhibited by P-selectin or PSGL-1 antagonists, and was reduced by 50% with a GPIIb/ IIIa antagonist. P-selectin or PSGL-1 antagonism abolished the enhanced secretion of platelet MMP-2 in the presence of neutrophils and reduced platelet-neutrophil aggregation. Platelet activation and binding to neutrophils enhance the secretion of platelet MMP-2 via an adhesive interaction between P-selectin and PSGL-1, which contribute to increase platelet-neutrophil aggregation.
Anti-thrombotic action of clopidogrel and PlA1/A2 polymorphism of β3 integrin in patients with coronary artery disease not being treated with aspirin
Authors: Dropinski Jerzy , Musial Jacek , Jakiela Bogdan , Wegrzyn Wojciech , Sanak Marek , Szczeklik Andrew 
Published: November 2005

SummaryIndividual variability in response to clopidogrel is known but its mechanism is poorly understood. We examined the relationship between glycoprotein IIIa polymorphism PlA1/A2 and anti-thrombotic actions of clopidogrel. Clopidogrel (75 mg/d; 2 weeks) was administered to 48 normolipemic patients with coronary artery disease. Bleeding time, thrombin generation at the site of microvascular injury, platelet function under high shear, using PFA-100 with ADP cartridge, and platelet surface activation markers (P-selectin and fibrinogen binding sites on GPIIb/IIIa complex detected by PAC-1 antibody), were studied both before and after clopidogrel treatment. Both unstimulated and low-dose (0.02 μM and 1 μM) in vitro ADP-stimulated platelets were examined. GP IIIa polymorphism was assessed by polymerase chain reaction and restriction fragment length polymorphism analysis. We identified 32 PlA1/A1 homozygotes, 15 PlA1/A2 heterozygotes and one PlA2/A2 homozygote. Clopidogrel significantly prolonged bleeding time in all subjects, but this effect was greater in PlA2 carriers (p<0.01). Furthermore, clopidogrel only depressed thrombin generation at the site of microvascular injury (p<0.01) in PlA2 patients and prolonged closure time measured in vitro by PFA-100 (p<0.05). At baseline spontaneous expression of PAC-1 and P-selectin was higher in PlA2 subjects as compared to PlA1 homozygotes (p<0.05 for both antigens). Clopidogrel lowered the expression of both markers affecting more PlA2 carriers, so that the difference in binding PAC-1 antibody between platelets from PlA1 and PlA2 carriers disappeared, while the difference in P-selectin expression slightly diminished. Anti-thrombotic effects of clopidogrel are more pronounced in CAD patients carrying the PlA2 allele than in PlA1 homozygotes.
Platelet integrin α2 I-domain specific antibodies produced via domain specific DNA vaccination combined with variable gene phage display
Authors: Hughes Darren L. , Stafford Prachi , Hamaia Samir W. , Schoolmeester Anne , Deckmyn Hans , Farndale Richard W. , Ouwehand Willem H. , Harmer Ian J. , Watkins Nicholas A. 
Published: November 2005

SummaryAntibodies are a powerful tool for structure/function studies of platelet proteins. However, classic immunisation frequently elicits antibody responses against domains of minor functional interest. Robust strategies to generate antibodies against defined domains would be of significant interest in post-genome research. In this study, we report a new strategy using a combination of DNA vaccination and V gene phage display that allows the rapid generation of domain specific single-chain Fv antibodies (scFvs).This system was validated using the I-domain of α2 integrin as a model. The α2β1 integrin, which is expressed on many cell types, is the dominant collagen attachment receptor on platelets, functioning in close interplay with the collagen signalling receptor glycoproteinVI. A novel set of I-domain specific antibodies was obtained by a DNA vaccination/V gene repertoire cloning approach. Mice were first immunized with a DNA vaccine in which the α2 I-domain is expressed as a fusion protein with fragment C of tetanus toxoid (FrC-TT).Then the heavy and kappa light chain variable gene repertoires were rescued from immune splenocytes using antibody phage display. A total of four α2 I-domain specific scFvs were isolated by selection on recombinant I-domain or native platelet α2β1 integrin. Characterisation of the scFvs indicated that they recognised distinct epitopes that had profound differences in accessibility between native and recombinant I-domain. Our data suggest DNA immunisation and phage display represent versatile alternatives to protein immunisation and hybridoma-fusion techniques for the isolation of recombinant antibody reagents. This approach will be particularly useful for the generation of domain or splicevariant specific antibodies that recognise native protein.
Fractalkine receptor polymorphisms V249I and T280M as genetic risk factors for restenosis
Authors: Marculescu Rodrig , Kvakan Heda , Haschemi Arvand , Endler Georg , Weyand Cornelia M. , Maurer Gerald , Mannhalter Christine , Wojta Johann , Wagner Oswald , Huber Kurt , Niessner Alexander 
Published: November 2005

SummaryThe chemokine fractalkine (FKN) recruits leukocytes into lesions of the arterial wall, which may lead to restenosis after stenting. FKN also regulates proliferation of smooth muscle cells, another mechanism pivotal to neointimal thickening. We assessed the hypothesis that functionally important polymorphisms of the FKN receptor CX3CR1 influence restenosis after coronary stenting. Three hundred and sixty-five patients undergoing coronary stenting were genotyped for the CX3CR1 polymorphisms V249I and T280M. Restenosis occurred in 25% of patients, and recurrent (> 1) restenosis at the target lesion in 8%.The allele I249 was associated with an increased risk of restenosis (adjusted odds ratio 2.4, 95% confidence interval: 1.3–4.2,P = 0.003) and recurrent restenosis (odds ratio 2.7,95% confidence interval:1.3–5.9,P = 0.011).Particularly, patients with I249 lacking the allele M280 were at an elevated risk of restenosis (P = 0.006) and, accordingly, the haplotype containing I249 but not M280 was more frequent in patients with restenosis (P = 0.001). In conclusion, the CX3CR1 I249 allele is associated with an increased risk of restenosis while the CX3CR1 M280 allele might counteract the harmful influence of I249.These findings show the importance of the chemokine FKN and genetic variations of its receptor for restenosis after coronary stenting. Recognition of these inherited risk modifiers may help to individualize treatment of coronary stenosis.
The influence of the haematocrit on primary haemostasis in vitro
Authors: Eugster Marco , Reinhart Walter H. 
Published: November 2005

SummaryPrimary haemostasis consists of platelet adhesion to subendothelial collagen, their activation and aggregation and finally the formation of a platelet plug. Erythrocytes are involved in this process because they flow in the center of the vessel and push platelets towards the site of action on the vessel wall and enhance shear forces, which activate platelets. In the platelet function analyzer PFA-100® (Dade Behring, Düdingen, Switzerland), the in vivo situation is simulated in vitro with blood being aspirated at high shear rates (5000s-1) through a capillary into a membrane pore with a diameter of 150 μm coated with type I collagen and either epinephrine or adenosine diphosphate. Aggregating platelets plug the pore and stop the flow, which is measured as the closure time. We analysed the influence of erythrocytes on platelet function analyzer measurements by systematic variation of the haematocrit (20,30,40,and 50%) at constant platelet counts of 289±61 ×103/μl plasma, or 152±30 ×103/μl blood, 96±9 ×103/μl blood and 54±5 ×103/μl blood, respectively. An inverse correlation was found between haematocrit and closure time under all circumstances. A decrease of the platelet count by 50 ×103 /μl could be compensated for by a 10% increase in haematocrit. The haematocrit must, therefore, be taken into consideration for the correct interpretation of PFA-100® measurements. Our data also provide a pathophysiological rationale to reduce the risk of bleeding in patients with thrombocytopenia and anaemia by normalizing the haematocrit with erythrocyte transfusions.
Molecular analysis of the heavy chain variable region genes of human hybridoma clones specific for coagulation factor VIII
Authors: Gharagozlou Soheila , Kardar Gholam Ali , Rabbani Hodjattallah , Shokri Fazel 
Published: November 2005

SummaryHemophilia A is a X-linked hematologic disorder characterized by undetectable or low amounts of functional coagulation factor VIII (FVIII). Replacement therapy induces FVIII neutralizing antibody (Ab) (inhibitor) in a proportion of patients which makes further treatment of these patients ineffective and costly. To envisage mechanisms underlying inhibitor development, seven hybridoma clones specific for FVIII were generated from two hemophiliaA patients with high titer of inhibitor. Specificity and isotype of the monoclonal antibodies (mAbs) were determined by ELISA. Immunoglobulin (Ig) variable region heavy (VH) chain gene family usage was identified by RT-PCR usingVH1–6 specific primers. Nucleotide sequences of the VH gene of FVIII specific clones were determined and aligned to the most homologous germ line genes in the GenBank. Analysis of the expressed VH genes by RT-PCR revealed that the hybridomas utilized either the VH1 (71%) or the VH3 (29%) gene family. Three VH domains were encoded by V1–69 (DP-10),V1–2 (DP-8),andV1–8 (DP-15) genes and two by V1–18 (DP-14) gene, all from the VH1 gene family. Of the VH3-gene family expressing clones, one belonged to V3–66 (DP-86) and the other one toV3–21 (DP-77) germline genes. The CDR3 length was found to be highly different amongst these clones ranging from 11 to 22 amino acid residues. These data suggest that FVIII-specific Abs preferentially use VH gene segments derived from VH1 gene family. Diversity of the expressed VH genes and their CDR3 length implies that different epitopes are recognized by these mAbs.
Molecular mechanisms of antithrombin deficiency in two Chinese families
Authors: Zhou Rong-Fu , Fu Qi-Hua , Wang Wen-Bin , Xie Shuang , Dai Jin , Ding Qiu-Lan , Wang Xue-Feng , Wang Zhen-Yi , Wang Hong-Li 
Published: November 2005

SummaryWe investigated the molecular mechanisms responsible for type I congenital antithrombin (AT) deficiency in two unrelated Chinese pedigrees manifesting multiple site venous thrombosis. Phenotype analysis showed both probands had almost 50% of normal AT levels. Direct sequencing of amplified DNA revealed 2757C>T in proband 1 and 13328G>A in proband 2, predicting a heterozygous Thr98Ile (T98I) and Ala404Thr (A404T), respectively. No proband had 20210A allele or factorV Leiden mutation. Transient expression of complementary DNA coding for the mutations in COS-7 cells showed impaired secretion of the mutant molecules. Real-time quantitative PCR indicated that the mutant AT mRNA was transcribed at a similar or even higher level as that of wild-type (wt). Pulse-chase labeling studies suggested both AT variants did not accumulate, but degraded intracellularly. Immunohistochemical staining of the transfected cells revealed that CHO cells expressing the AT-I98 mutant were stained diffusely without perinuclear enhancement and cells expressing AT-T404 mutant mainly in the whole cytoplasm with weaker perinuclear enhancement. We conclude that the impaired secretion of the mutant AT molecules, due to intracellular degradation, is the molecular pathogenesis of AT deficiency caused by T98I and A404T mutation for the two families, respectively.
Interleukin-18 and Macrophage Migration Inhibitory Factor Are Associated With Increased Carotid Intima–Media Thickening
Authors: Korshunov Vyacheslav A. , Nikonenko Tatiana A. , Tkachuk Vsevolod A. , Brooks Andrew , Berk Bradford C. 
Published: November 2005

Objective—Carotid intima–media thickening (IMT) is a form of vascular remodeling that has a strong genetic component. Recently, we discovered that in response to decreased carotid blood flow SJL mice developed the largest intima among 5 inbred strains. Because the SJL strain is prone to autoimmune diseases, we hypothesized that inflammation contributed to IMT in SJL mice.Methods and Results—We compared vascular remodeling (induced by 2 weeks of low flow) in 2 strains with small IMT (C3H/HeJ and C3HeB/FeJ) versus 2 strains with large IMT (FVB/NJ and SJL/J). Quantitative immunohistochemistry showed a dramatic increase in inflammatory cells per intima area in SJL compared with other strains. Microarray profiling of inflammatory gene mRNAs from carotids showed significant increases in interleukin (IL)-18 and Mif gene expression in SJL compared with C3HeB/FeJ mice. Increased expression of these genes was confirmed by quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. Furthermore, greater cell proliferation in the intima of SJL accounted for increased intima–media thickening, whereas a higher level of apoptosis and a lower level of proliferation were observed in C3HeB/FeJ mice.Conclusion—The present study indicates that increased expression of Mif and IL-18 cytokines is associated with intima–media thickening in SJL mice, likely by stimulating inflammation and proliferation.
Optimization of Transplant Regimens for Patients with Myelodysplastic Syndrome (MDS)
Authors: Deeg H. Joachim 
Published: November 2005

Abstract
Myelodysplastic syndrome (MDS) is a hemopoietic stem cell disorder that is potentially curable by transplantation of normal hemopoietic stem cells. The optimum timing, however, and the best conditioning strategy have remained controversial. Both conventional and reduced-intensity/nonmyeloablative regimens have been used successfully. Among selected patients with less advanced/low-risk MDS (< 5% marrow myeloblasts), 3-year survivals of 65% to 75% are achievable with HLA-matched related and unrelated donors. Among patients with more advanced/ high-risk disease (≥ 5% marrow blasts; high International Prognostic Scoring System [IPSS] scores), the probability of post-transplant relapse ranges from 10% to 40%, and, as a result, relapse-free survival is inferior. In addition to disease stage, co-morbid conditions, pre-transplant chemotherapy, conditioning regimen, source of stem cells, and post-transplant immunosuppression affect transplant outcome. Reduced-intensity conditioning regimens are associated with a decrease in non-relapse mortality and allow for successful hemopoietic stem cell transplants even in patients 60–70 years of age. Graft-versus-host disease, both acute and chronic, and post-transplant relapse remain challenging problems.
Specialization, kinetics, and repertoire of type 1 interferon responses by human plasmacytoid predendritic cells
Authors: Ito Tomoki , Kanzler Holger , Duramad Omar , Cao Wei , Liu Yong-Jun 
Published: November 2005

AbstractRecent studies suggest plasmacytoid predendritic cells (pDCs) and myeloid dendritic cells (mDCs) have the functional plasticity to produce similar amounts of type 1 interferons (IFNs) and interleukin-12 (IL-12), challenging the concept and existence of DC subsets with distinct function. In this study, we demonstrate that previous studies showed human pDCs produce large amounts of IL-12 because of contaminating mDCs. Using highly purified human DC subsets, we found that although pDCs make 300 times more IFN-α than mDCs and mDCs make 13 times more IL-12 p70 than pDCs in response to all the toll-like receptor ligands and CD40 ligands, pDCs rapidly make large amounts of IFN-α within the first 12 hours of activation and become refractory to further stimulation. pDCs preferentially expressed the transcriptional factors critical for type 1 IFN, but not for IL-12 transcription, and they dedicated 60% of new transcriptional activity to make 19 type 1 IFN subtypes. This study provides formal proof that the plasticity of DC subsets is limited and that different DC subsets evolve to perform distinct functions in linking innate and adaptive immunity. (Blood. 2006;107:2423-2431)
CD38 orchestrates migration, survival, and Th1 immune response of human mature dendritic cells
Authors: Frasca Loredana , Fedele Giorgio , Deaglio Silvia , Capuano Cristina , Palazzo Raffaella , Vaisitti Tiziana , Malavasi Fabio , Ausiello Clara Maria 
Published: November 2005

AbstractCD38, an ectoenzyme and a signaling receptor, is a novel marker of human mature monocyte-derived dendritic cells (MDDCs). The working hypothesis is that CD38 is not only a marker but also contributes to functions specifically gained by MDDCs with maturation. This was tested by assessing the role(s) of CD38 after signaling with agonistic anti-CD38 monoclonal antibodies or by blocking the interactions taking place between CD38 and CD31, its counterreceptor. The results indicate the following: (1) CD38 engagement in MDDCs ensures efficient chemotaxis and transendothelial migration driven by CC chemokine ligand 21 (CCL21); (2) CD38 is laterally associated with the CCL21-specific CC chemokine receptor 7 and with CD83 and CD11b; (3) CD38 localizes in membrane lipid domains; (4) CD38 signaling contributes to support longevity of lipopolysaccharide (LPS)–matured MDDCs after growth factor withdrawal; and (5) IFN-γ is produced by cocultured T lymphocytes, thus affecting T-helper 1 (Th1) polarization. These data suggest that the localization of CD38 in lipid rafts and its multiple interactions with signaling receptors rule innate and adaptive immune responses by tuning DC migration, survival, and Th1-polarization ability. These findings may lay out the basis to assess the functional role(s) of human CD38 in infections, autoimmune diseases, and neoplastic disorders.
High frequency of alternative first exons in erythroid genes suggests a critical role in regulating gene function
Authors: Tan Jeff S. , Mohandas Narla , Conboy John G. 
Published: November 2005

AbstractThe human genome uses alternative pre-mRNA splicing as an important mechanism to encode a complex proteome from a relatively small number of genes. An unknown number of these genes also possess multiple transcriptional promoters and alternative first exons that contribute another layer of complexity to gene expression mechanisms. Using a collection of more than 100 erythroid-expressed genes as a test group, we used genome browser tools and genetic databases to assess the frequency of alternative first exons in the genome. Remarkably, 35% of these erythroid genes show evidence of alternative first exons. The majority of the candidate first exons are situated upstream of the coding exons, whereas a few are located internally within the gene. Computational analyses predict transcriptional promoters closely associated with many of the candidate first exons, supporting their authenticity. Importantly, the frequent presence of consensus translation initiation sites among the alternative first exons suggests that many proteins have alternative N-terminal structures whose expression can be coupled to promoter choice. These findings indicate that alternative promoters and first exons are more widespread in the human genome than previously appreciated and that they may play a major role in regulating expression of selected protein isoforms in a tissue-specific manner. (Blood. 2006;107: 2557-2561)
Patterns of expression, membrane localization, and effects of ectopic expression suggest a function for MS4a4B, a CD20 homolog in Th1 T cells
Authors: Xu Hui , Williams Mark S. , Spain Lisa M. 
Published: November 2005

AbstractThe membrane-spanning 4A (MS4A) family of proteins includes CD20, FcϵRIβ, and HTm4, whose genes are grouped in a chromosomal location that is associated with increased susceptibility to allergy and atopic asthma. One family member, Chandra/MS4a4B, was reported to be expressed in T helper 1 (Th1) T cells but not Th2 T cells. In the present study, Ms4a4b was isolated in a screen of genes differentially expressed during thymocyte development. MS4a4B was detected in immature CD4-CD8-CD44+CD25- thymocytes, turned off during further stages of thymocyte development and reexpressed in mature single-positive thymocytes. MS4a4B expression was found in naive CD8+ and CD4+ peripheral T cells and natural killer (NK) cells but not in B cells. MS4a4B is expressed at the cell surface with its C-terminus located in the cytoplasm. When expressed in a T-cell hybridoma by retroviral vector, MS4a4B protein constitutively associated with lipid raft microdomains, whereas in primary T cells endogenous MS4a4B protein became enriched in rafts after T-cell activation. Overexpression of MS4a4B in primary CD4+ T-cell blasts enhanced T-cell receptor (TCR)-induced Th1 cytokine production. These results suggest that MS4a4B expression is tightly regulated during T-cell development and that MS4a4B expression promotes Th1 function and/or differentiation. (Blood. 2006;107:2400-2408)