bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Note on Postian Matrix Theory
Authors: Serfati Michel 
Published: October 2003

The present paper is devoted to some aspects of postian matrix theory over an arbitrary Post algebra, through results in Postian relative–pseudocomplementation. It is well known (for instance Rousseau [10] or Dwinger [6]) that any r-Post algebra is a Brouwerian lattice (or a Heyting algebra), that is to say, for every (a, b) in P2, the set of x in P such as a. x ≤ b admits a greatest element (a.x is inf {a, x}), called the relative inf–pseudocomplement of a in b, and denoted (b|a). In the first part of our paper, we compute the explicit expression of the disjunctive components of the relative inf–pseudocomplement (Theorem 2), which allows us to state some specific new properties of Postian pseudocomplementation, among which the cases where (b|a) is a Boolean element, and the equation (x|a) = c (Theorem 4), for which we give a consistency condition. Relative pseudo complementation in fact plays a major role in Postian structures, since we show (Theorem 5), that every element a in P is completely determined by the sequence of the (ek|a): in fact, being given (r-1) elements of P submitted to the ascending chain condition: α1 ≤ α2 ≤ … ≤ αr-1, there exists exactly one a in P such as (ek|a) = αk for every k, where the ek are the elements of the underlying chain in P. Study of pseudocomplementation properties in some Post algebra P actually helps us to enlighten relations between P and, on one hand, its center B (the set of its complemented elements, which is a Boolean algebra), on the other hand, the underlying chain. The second part is devoted to Postian linear matrix equations and inequations: in fact just like in Boolean algebras, the existence of the inf–pseudocomplement in the underlying lattice implies the residuation property is valid over the ordered semi-group of Postian matrices, equipped with the matrix product ⊗ (this was a general theorem from Blyth [3]): the Postian matrix inequation A ⊗ X ≤ B thus admits a greatest solution (Theorem 6), which is explicitly computed. This provides a consistency condition for the matrix equation A ⊗ X = B (Theorem 7). Another result states a characterization of inversible square Postian matrices. On this point of inversibility, as it is well known, the Boolean results were built in three successive steps by Wedderbrun [17], Luce [9] and Rutherford [13]. As to the Postian case, we prove in turn that a Postian matrix is inversible if and only if it is Boolean and orthogonal (Theorem 11). To prove this result, as well as Theorem 2 in the first part, we make a systematic use of the representation theorem for Post algebras by the Boolean way, as enunciated in the Preliminaries (Theorem 1). Repeated applications of the method provide a large set of conditions equivalent to the inversibility of a Postian matrix (Theorem 12). Afterwards, we examine various other Postian matrix equations and inequations, among which t A ⊗ A ≤ I, leading to the characterization of right–distributive over conjunction–Postian matrices (Theorem 9), and also the equation A ⊗ X = Ek, for which it is given a complete consistency condition (Theorem 13).
On the Algebra of Semigroup Diagrams
Authors: Kilibarda Vesna 
Published: October 2003

In this work we enrich the geometric method of semigroup diagrams to study semigroup presentations. We introduce a process of reduction on semigroup diagrams which leads to a natural way of multiplying semigroup diagrams associated with a given semigroup presentation. With respect to this multiplication the set of reduced semigroup diagrams is a groupoid. The main result is that the groupoid [Formula: see text] of reduced semigroup diagrams over the presentation S = <X:R> may be identified with the fundamental groupoid γ (KS) of a certain 2-dimensional complex KS. Consequently, the vertex groups of the groupoid [Formula: see text] are isomorphic to the fundamental groups of the complex KS. The complex we discovered was first considered in the paper of Craig Squier, published only recently. Steven Pride has also independently defined a 2-dimensional complex isomorphic to KS in relation to his work on low-dimensional homotopy theory for monoids. Some structural information about the fundamental groups of the complex KS are presented. The class of these groups contains all finitely generated free groups and is closed under finite direct and finite free products. Many additional results on the structure of these groups may be found in the paper of Victor Guba and Mark Sapir.
Estrogen Receptor-α Polymorphisms and Angiographic Outcome After Coronary Artery Stenting
Authors: Ferrero Valeria , Ribichini Flavio , Matullo Giuseppe , Guarrera Simonetta , Carturan Sonia , Vado Antonello , Vassanelli Corrado , Piazza Alberto , Uslenghi Eugenio , Wijns William 
Published: October 2003

Objective—Because of the receptor-mediated antiproliferative effects of estradiol on vascular smooth muscle cells, our study aimed at identifying a role of PvuII and XbaI polymorphisms of the α-estrogen receptor (αER) gene in the occurrence of restenosis after coronary stent implantation (in-stent restenosis [ISR]).Methods and Results—In 858 patients (148 women), 955 lesions were treated with stent implantation, and the PvuII C/T and XbaI G/A polymorphisms of the αER gene were determined. Quantitative angiography was performed before and after stenting and at 6-month follow-up. The allelic frequencies were similar between sexes (C/T allele, 0.43/0.57 and 0.44/0.56;P=0.9; G/A allele, 0.35/0.65 and 0.38/0.62;P=0.8; in women and men, respectively). A significantly higher ISR rate in women than in men homozygous for the T-allele of the PvuII polymorphism (42.6% versus 26.9%,P=0.03) or the G-allele of the XbaI polymorphism (41.2% versus 19.4%,P=0.04) was observed. At multivariate analysis, T/T genotype was the only independent predictor of ISR in women but not in men (odds ratio, 1.5; 95% CI, 1.0 to 2.1;P=0.03). XbaI polymorphism was no longer associated with ISR in both sexes.Conclusions—Women homozygous for the T-allele of the PvuII polymorphism of the αER gene treated with coronary stent implantation have a higher risk of ISR than men.
Dynamic regulation of Src-family kinases by CD45 in B cells
Authors: Shrivastava Punya , Katagiri Tatsuo , Ogimoto Mami , Mizuno Kazuya , Yakura Hidetaka 
Published: October 2003

AbstractCD45 is a key protein tyrosine phosphatase regulating Src-family protein tyrosine kinases (Src-PTKs) in lymphocytes; precisely how it exerts its effect remains controversial, however. We previously demonstrated that CD45 negatively regulates Lyn in the WEHI-231 B-cell line. Here we show that negative regulation by CD45 is physiologically significant in B cells and that some CD45 is constitutively associated with glycolipid-enriched microdomains (GEMs), where it inhibits Src-PTKs by dephosphorylating both the negative and the positive regulatory sites. Upon B-cell receptor (BCR) ligation, however, CD45 dissociates from GEMs within 30 seconds, inducing phosphorylation of 2 regulatory sites and activation of Src-PTKs, but subsequently reassociates with the GEMs within 15 minutes. Disruption of GEMs with methyl-β-cyclodextrin results in abrogation of BCR-induced apoptosis in WEHI-231 cells, suggesting GEMs are critical to signals leading to the fate determination. We propose that the primary function of CD45 is inhibition of Src-PTKs and that the level of Src-PTK activation and the B-cell fate are determined in part by dynamic behavior of CD45 with respect to GEMs.
Platelet receptor interplay regulates collagen-induced thrombus formation in flowing human blood
Authors: Siljander Pia R.-M. , Munnix Imke C. A. , Smethurst Peter A. , Deckmyn Hans , Lindhout Theo , Ouwehand Willem H. , Farndale Richard W. , Heemskerk Johan W. M. 
Published: October 2003

AbstractThe platelet glycoproteins (GPs) Ib, integrin α2β1, and GPVI are considered central to thrombus formation. Recently, their relative importance has been re-evaluated based on data from murine knockout models. To examine their relationship during human thrombus formation on collagen type I fibers at high shear (1000 s–1), we tested a novel antibody against GPVI, an immunoglobulin single-chain variable fragment, 10B12, together with specific antagonists for GPIbα (12G1 Fab2) and α2β1 (6F1 mAb or GFOGER-GPP peptide). GPVI was found to be crucial for aggregate formation, Ca2+ signaling, and phosphatidylserine (PS) exposure, but not for primary adhesion, even with more than 97% receptor blockade. Inhibiting α2β1 revealed its involvement in regulating Ca2+ signaling, PS exposure, and aggregate size. Both GPIbα and α2β1 contributed to primary adhesion, showing overlapping function. The coinhibition of receptors revealed synergism in thrombus formation: the coinhibition of adenosine diphosphate (ADP) receptors with collagen receptors further decreased adhesion and aggregation, and, crucially, the complete eradication of thrombus formation required the coinhibition of GPVI with either GPIbα or α2β1. In summary, human platelet deposition on collagen depends on the concerted interplay of several receptors: GPIb in synergy with α2β1 mediating primary adhesion, reinforced by activation through GPVI, which further regulates the thrombus formation.
LPAM (α4β7 integrin) is an important homing integrin on alloreactive T cells in the development of intestinal graft-versus-host disease
Authors: Petrovic Aleksandra , Alpdogan Onder , Willis Lucy M. , Eng Jeffrey M. , Greenberg Andrew S. , Kappel Barry J. , Liu Chen , Murphy George J. , Heller Glenn , van den Brink Marcel R. M. 
Published: October 2003

AbstractLymphocyte Peyer patch adhesion molecule (LPAM) or α4β7 integrin is expressed on lymphocytes and is responsible for T-cell homing into gut-associated lymphoid tissues through its binding to mucosal addressin cell adhesion molecule (MAdCAM), which is present on high endothelial venules of mucosal lymphoid organs. We found in murine allogeneic bone marrow transplantation (BMT) models that recipients of α4β7– donor T cells had significantly less graft-versus-host disease (GVHD) morbidity and mortality compared with recipients of α4β7+ donor T cells. A kinetic posttransplantation analysis of lymphocytes in the intestines and mesenteric lymph nodes demonstrated a delayed invasion of lower numbers of α4β7+ T cells in recipients of α4β7– T cells compared with recipients of α4β7+ T cells. Histopathologic analysis of GVHD target organs revealed that recipients of α4β7– T cells developed less GVHD of the intestines and liver, whereas there was no difference in cutaneous and thymic GVHD between recipients of α4β7– or α4β7+ T cells. Finally, we found that in vivo GVT activity of α4β7– donor T cells was preserved. We conclude that the α4β7 integrin is important for the invasion of alloreactive donor T cells into the gut and the subsequent development of intestinal GVHD and overall GVHD morbidity and mortality.
Regulation of MHC class II expression in human T-cell malignancies
Authors: Holling Tjadine M. , Schooten Erik , Langerak Anton W. , van den Elsen Peter J. 
Published: October 2003

AbstractExpression of major histocompatibility complex (MHC) class II molecules in human activated T cells is under normal circumstances regulated exclusively by the CIITA-PIII subtype of the class II transactivator (CIITA). In this study, we show that the absence of MHC class II expression in leukemic T cells was due to a lack of expression of CIITA, whereas in T-lymphoma cells, expression of CIITA correlated with expression of MHC class II. Interestingly, activation of a CIITA-promoter (P)III–reporter construct was not affected in leukemic T cells. This revealed that the absence of endogenous CIITA expression was not caused by a lack of transcription factors critical for CIITA-PIII activation but suggests the involvement of an epigenetic silencing mechanism. Subsequent analysis showed that the lack of human leukocyte antigen–DR (HLA-DR) expression correlated with hypermethylation of CIITA-PIII in leukemic T-cell lines and in primary T-cell acute lymphoblastic leukemia (T-ALL) and a T-cell prolymphocytic leukemia (T-PLL). Treatment of leukemic T-cell lines with a demethylation agent showed re-expression of CIITA-PIII and HLA-DRA. Furthermore, in vitro methylation of CIITA-PIII and subsequent assessment of CIITA-PIII activity in Jurkat leukemic T cells resulted in reduction of constitutive and CREB-1 (cyclic adenosine monophosphate [cAMP]–response element binding protein 1)–induced promoter activity. Together, these results argue for an important role of DNA hyper-methylation in the control of CIITA expression in leukemic T cells.
Eμ-BRD2 transgenic mice develop B-cell lymphoma and leukemia
Authors: Greenwald Rebecca J. , Tumang Joseph R. , Sinha Anupama , Currier Nicolas , Cardiff Robert D. , Rothstein Thomas L. , Faller Douglas V. , Denis Gerald V. 
Published: October 2003

AbstractTransgenic mice with lymphoid-restricted overexpression of the double bromodomain protein bromodomain-containing 2 (Brd2) develop splenic B-cell lymphoma and, upon transplantation, B-cell leukemia with leukemic infiltrates in liver and lung. Brd2 is a nuclear-localized transcription factor kinase that is most closely related to TATA box binding protein–associated factor, 250 kDa (TAFII250) and the Drosophila developmental protein female sterile homeotic. Constitutive expression of BRD2 in the lymphoid compartment increases cyclin A transcription, “priming” transgenic B cells for proliferation. Mice stochastically develop an aggressive B-cell lymphoma with the features of B-1 cells, including CD5 and surface IgM expression. The B-cell lymphoma is monoclonal for immunoglobulin gene rearrangement and is phenotypically stable. The lymphoblasts are very large and express a transcriptome that is similar to human non-Hodgkin lymphomas. Both a wild-type BRD2 transgene and a kinase-null point mutant drive lymphomagenesis; therefore we propose that, rather than kinase activity, Brd2-mediated recruitment of E2 promoter binding factors (E2Fs) and a specific histone acetyltransferase to the cyclinA promoter by both types of transgene is a mechanistic basis for neoplasia. This report is the first to describe a transgenic mouse model for constitutive expression of a protein with more than one bromodomain.
Complete response to donor lymphocyte infusion in multiple myeloma is associated with antibody responses to highly expressed antigens
Authors: Bellucci Roberto , Wu Catherine J. , Chiaretti Sabina , Weller Edie , Davies Faith E. , Alyea Edwin P. , Dranoff Glenn , Anderson Kenneth C. , Munshi Nikhil C. , Ritz Jerome 
Published: October 2003

Abstract
The ability of donor lymphocyte infusions (DLIs) to induce complete responses (CRs) in patients with relapsed myeloma after allogeneic bone marrow transplantation (BMT) provides clear evidence of an effective graft-versus-myeloma (GVM) response. To identify target antigens of the GVM response, we screened a myeloma cDNA expression library with post-DLI serum from 4 patients with myeloma who achieved CR after DLI and 1 patient who was in CR before DLI. We identified a panel of 13 gene products reactive with post-DLI serum but negative with pre-DLI and pre-BMT serum. Antibodies to these proteins were not detected in the sera of 10 patients who underwent allogeneic BMT without DLI and 5 patients with acute graft-versus-host disease (GVHD). Minimal reactivity with these proteins was detected in the sera of 20 healthy donors and 20 patients with chronic GVHD. In contrast, 5 of these proteins were recognized by more than 1 myeloma DLI responder. Testing of serial serum samples showed an association between antibody response and time of best response after DLI. The expression of these genes was evaluated in primary myeloma cells and in normal plasma cells. This study demonstrates that the GVM response is associated with antibody responses to highly expressed myeloma-associated antigens.
Pharmacologically regulated Fas-mediated death of adoptively transferred T cells in a nonhuman primate model
Authors: Berger Carolina , Blau C. Anthony , Huang Meei-Li , Iuliucci John D. , Dalgarno David C. , Gaschet Joëlle , Heimfeld Shelly , Clackson Tim , Riddell Stanley R. 
Published: October 2003

AbstractConditional suicide genes derived from pathogens have been developed to confer drug sensitivity and enhance safety of cell therapy, but this approach is limited by immune responses to the transgene product. We examined a strategy to regulate survival of transferred cells based on induction of apoptosis through oligomerization of a modified human Fas receptor by a bivalent drug (AP1903). Three macaques (Macaca nemestrina) received autologous T cells retrovirally engineered to express a Fas suicide-construct (LV'VFas). High levels of transduced cells were present in blood following cell transfer, but LV'VFas+ cells declined rapidly after AP1903 administration. A small fraction of LV'VFas+ cells resisted elimination by AP1903, in part due to insufficient levels of transgene expression in resting T cells, because reactivation of these cells in vitro enhanced sensitivity to AP1903. An immune response to the transgene product was observed, but epitope mapping indicated the response was directed to discrete components of human LV'VFas that were variant with the corresponding macaque sequences. These data demonstrate that chemically induced dimerization can be used to regulate survival of adoptively transferred T cells in vivo.
Pleural drainage using central venous catheters
Authors: Singh Kulgit , Loo Shi , Bellomo Rinaldo 
Published: October 2003

Abstract
Introduction
The objective of the present study was to evaluate the use of a single lumen 16 G central venous catheter for the drainage of uncomplicated pleural effusions in intensive care unit patients.

Methods
A prospective observational study was performed in two intensive care units of university-affiliated hospitals. The study involved 10 intensive care unit patients with non-loculated large effusions. A 16 G central venous catheter was inserted at the bedside without ultrasound guidance using the Seldinger technique. The catheter was left in situ until radiological resolution of the effusion.

Results
Fifteen sets of data were obtained. The mean and standard deviation of the volumes drained at 1, 6 and 24 hours post catheter insertion were 454 ± 241 ml, 756 ± 403 ml and 1010 ± 469 ml, respectively. The largest volume drained in a single patient was 6030 ml over 11 days. The longest period for which the catheter remained in situ without evidence of infection was 14 days. There were no instances of pneumothorax, hemothorax, re-expansion pulmonary edema and catheter blockage/ disconnections.

Conclusions
The use of an indwelling 16 G central venous catheter is efficacious in draining uncomplicated large pleural effusions. It is well tolerated by patients and is associated with minimal complications. It has the potential to avoid repeated thoracentesis or the use of large-bore chest tubes.
Predictors of Occult Metastasis in Clinical Stage I Nonseminoma: A Systematic Review
Authors: Vergouwe Yvonne , Steyerberg Ewout W. , Eijkemans Marinus J.C. , Albers Peter , Habbema J. Dik F. 
Published: October 2003

Purpose: Patients with clinical stage I nonseminomatous testicular germ cell tumor should ideally receive adjuvant therapy only when they are at high risk for occult metastasis. We aimed to quantify the importance of predictors for occult metastasis by performing a systematic review of the relevant literature. In addition, we reviewed published multivariable models and risk-adapted treatment policies. Patients and Methods: We identified 23 publications between 1979 and 2001, reporting a total of 2,587 patients. Twenty-nine percent of the patients (759 of 2,587 patients) had occult metastases, which was diagnosed either at retroperitoneal lymph node dissection (n = 193) or during follow-up (n = 566). Odds ratios (OR) were pooled using meta-analysis techniques. Results: The presence of vascular invasion of the primary tumor cells had the strongest effect (OR, 5.2; 95% CI, 4.0 to 6.8). Immunohistochemical staining of the primary tumor cells with the MIB-1 monoclonal antibody showing proliferative activity was a promising predictor (OR, 4.7; 95% CI, 2.0 to 11). Intermediate effects were found for embryonal carcinoma in the primary tumor (OR, 2.9; 95% CI, 2.0 to 4.4) and a high pathologic stage of the tumor (OR, 2.6; 95% CI, 1.8 to 3.8). Size of the primary tumor and age of the patient had weaker though also statistically significant associations with occult metastasis. Until now, multivariable models often included vascular invasion and embryonal carcinoma with one or two weaker predictors. None of the published risk-adapted treatment policies included MIB-1 staining. Conclusion: Several strong predictors for occult metastasis were identified. A risk-adapted treatment policy should be developed that incorporates all relevant predictors so that adjuvant therapy is targeted better to those with occult metastases.
The Costs of Conducting Clinical Research
Authors: Emanuel Ezekiel J. , Schnipper Lowell E. , Kamin Deborah Y. , Levinson Jenifer , Lichter Allen S. 
Published: October 2003

Purpose: Physicians frequently receive payment for enrolling subjects onto clinical trials. Some view these payments as conflicts of interest. Others contend that these payments are necessary reimbursements for conducting clinical research. We evaluated the clinical and nonclinical hours and costs associated with conducting a mock phase III clinical research trial. Methods: We collected data from representatives of 21 clinical sites, on the numbers of hours associated with 13 activities necessary to the conduct of clinical research. The hours were based on enrolling 20 patients in a 12-month randomized placebo-controlled trial of a new chemotherapeutic agent. The outcome measures were disease progression and quality-of-life reports. These costs were evaluated for both government and pharmaceutical industry–sponsored trials. Results: On average, 4,012 hours (range, 1,512 to 13,319 hours) were required for a government-sponsored trial, and 3,998 hours (range: 1735 to 15,699) were required for a pharmaceutical industry–sponsored trial involving 20 subjects with 17 office visits, or approximately 200 hours per subject. Thirty-two percent of the hours were devoted to nonclinical activities, such as institutional review board submission and completion of clinical reporting forms. On average, excluding overhead expenses, it cost slightly more than $6,094 (range, $2,098 to $19,285) per enrolled subject for an industry-sponsored trial, including $1,999 devoted to nonclinical costs. Conclusion: Based on the results of our mock trial, the time required for nontreatment trial activities is considerable, and the associated costs are substantial.